/* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2008-2011 Apple Inc. All rights reserved. * * Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc. * ("Apple") in consideration of your agreement to the following terms, and your * use, installation, modification or redistribution of this Apple software * constitutes acceptance of these terms. If you do not agree with these terms, * please do not use, install, modify or redistribute this Apple software. * * In consideration of your agreement to abide by the following terms, and subject * to these terms, Apple grants you a personal, non-exclusive license, under Apple's * copyrights in this original Apple software (the "Apple Software"), to use, * reproduce, modify and redistribute the Apple Software, with or without * modifications, in source and/or binary forms; provided that if you redistribute * the Apple Software in its entirety and without modifications, you must retain * this notice and the following text and disclaimers in all such redistributions of * the Apple Software. Neither the name, trademarks, service marks or logos of * Apple Inc. may be used to endorse or promote products derived from the * Apple Software without specific prior written permission from Apple. Except as * expressly stated in this notice, no other rights or licenses, express or implied, * are granted by Apple herein, including but not limited to any patent rights that * may be infringed by your derivative works or by other works in which the Apple * Software may be incorporated. * * The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN * COMBINATION WITH YOUR PRODUCTS. * * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION * OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT * (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include // For stdout, stderr #include "ClientCommon.h" const char *GetNextLabel(const char *cstr, char label[64]) { char *ptr = label; while (*cstr && *cstr != '.') // While we have characters in the label... { char c = *cstr++; if (c == '\\') // If escape character, check next character { if (*cstr == '\0') break; // If this is the end of the string, then break c = *cstr++; if (isdigit(cstr[-1]) && isdigit(cstr[0]) && isdigit(cstr[1])) { int v0 = cstr[-1] - '0'; // then interpret as three-digit decimal int v1 = cstr[ 0] - '0'; int v2 = cstr[ 1] - '0'; int val = v0 * 100 + v1 * 10 + v2; // If valid three-digit decimal value, use it // Note that although ascii nuls are possible in DNS labels // we're building a C string here so we have no way to represent that if (val == 0) val = '-'; if (val <= 255) { c = (char)val; cstr += 2; } } } *ptr++ = c; if (ptr >= label+64) { label[63] = 0; return(NULL); } // Illegal label more than 63 bytes } *ptr = 0; // Null-terminate label text if (ptr == label) return(NULL); // Illegal empty label if (*cstr) cstr++; // Skip over the trailing dot (if present) return(cstr); } /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2008 Apple Inc. All rights reserved. * * Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Computer, Inc. * ("Apple") in consideration of your agreement to the following terms, and your * use, installation, modification or redistribution of this Apple software * constitutes acceptance of these terms. If you do not agree with these terms, * please do not use, install, modify or redistribute this Apple software. * * In consideration of your agreement to abide by the following terms, and subject * to these terms, Apple grants you a personal, non-exclusive license, under Apple's * copyrights in this original Apple software (the "Apple Software"), to use, * reproduce, modify and redistribute the Apple Software, with or without * modifications, in source and/or binary forms; provided that if you redistribute * the Apple Software in its entirety and without modifications, you must retain * this notice and the following text and disclaimers in all such redistributions of * the Apple Software. Neither the name, trademarks, service marks or logos of * Apple Computer, Inc. may be used to endorse or promote products derived from the * Apple Software without specific prior written permission from Apple. Except as * expressly stated in this notice, no other rights or licenses, express or implied, * are granted by Apple herein, including but not limited to any patent rights that * may be infringed by your derivative works or by other works in which the Apple * Software may be incorporated. * * The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN * COMBINATION WITH YOUR PRODUCTS. * * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION * OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT * (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ extern const char *GetNextLabel(const char *cstr, char label[64]); /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc. * ("Apple") in consideration of your agreement to the following terms, and your * use, installation, modification or redistribution of this Apple software * constitutes acceptance of these terms. If you do not agree with these terms, * please do not use, install, modify or redistribute this Apple software. * * In consideration of your agreement to abide by the following terms, and subject * to these terms, Apple grants you a personal, non-exclusive license, under Apple's * copyrights in this original Apple software (the "Apple Software"), to use, * reproduce, modify and redistribute the Apple Software, with or without * modifications, in source and/or binary forms; provided that if you redistribute * the Apple Software in its entirety and without modifications, you must retain * this notice and the following text and disclaimers in all such redistributions of * the Apple Software. Neither the name, trademarks, service marks or logos of * Apple Inc. may be used to endorse or promote products derived from the * Apple Software without specific prior written permission from Apple. Except as * expressly stated in this notice, no other rights or licenses, express or implied, * are granted by Apple herein, including but not limited to any patent rights that * may be infringed by your derivative works or by other works in which the Apple * Software may be incorporated. * * The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN * COMBINATION WITH YOUR PRODUCTS. * * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION * OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT * (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * To build this tool, copy and paste the following into a command line: OS X: gcc dns-sd.c -o dns-sd POSIX systems: gcc dns-sd.c -o dns-sd -I../mDNSShared -ldns_sd Windows: cl dns-sd.c -I../mDNSShared -DNOT_HAVE_GETOPT ws2_32.lib ..\mDNSWindows\DLL\Release\dnssd.lib (may require that you run a Visual Studio script such as vsvars32.bat first) */ // For testing changes to dnssd_clientstub.c, uncomment this line and the code will be compiled // with an embedded copy of the client stub instead of linking the system library version at runtime. // This also useful to work around link errors when you're working on an older version of Mac OS X, // and trying to build a newer version of the "dns-sd" command which uses new API entry points that // aren't in the system's /usr/lib/libSystem.dylib. //#define TEST_NEW_CLIENTSTUB 1 #include #include // For stdout, stderr #include // For exit() #include // For strlen(), strcpy() #include // For errno, EINTR #include #include // For u_char #ifdef APPLE_OSX_mDNSResponder #include // For PRId64 #endif // APPLE_OSX_mDNSResponder #if APPLE_OSX_mDNSResponder #include #include "xpc_clients.h" #endif #ifdef _WIN32 #include #include #include #include typedef int pid_t; #define getpid _getpid #define strcasecmp _stricmp #define snprintf _snprintf static const char kFilePathSep = '\\'; #ifndef HeapEnableTerminationOnCorruption # define HeapEnableTerminationOnCorruption (HEAP_INFORMATION_CLASS)1 #endif #if !defined(IFNAMSIZ) #define IFNAMSIZ 16 #endif #define if_nametoindex if_nametoindex_win #define if_indextoname if_indextoname_win typedef PCHAR (WINAPI * if_indextoname_funcptr_t)(ULONG index, PCHAR name); typedef ULONG (WINAPI * if_nametoindex_funcptr_t)(PCSTR name); unsigned if_nametoindex_win(const char *ifname) { HMODULE library; unsigned index = 0; // Try and load the IP helper library dll if ((library = LoadLibrary(TEXT("Iphlpapi")) ) != NULL ) { if_nametoindex_funcptr_t if_nametoindex_funcptr; // On Vista and above there is a Posix like implementation of if_nametoindex if ((if_nametoindex_funcptr = (if_nametoindex_funcptr_t) GetProcAddress(library, "if_nametoindex")) != NULL ) { index = if_nametoindex_funcptr(ifname); } FreeLibrary(library); } return index; } char * if_indextoname_win( unsigned ifindex, char *ifname) { HMODULE library; char * name = NULL; // Try and load the IP helper library dll if ((library = LoadLibrary(TEXT("Iphlpapi")) ) != NULL ) { if_indextoname_funcptr_t if_indextoname_funcptr; // On Vista and above there is a Posix like implementation of if_indextoname if ((if_indextoname_funcptr = (if_indextoname_funcptr_t) GetProcAddress(library, "if_indextoname")) != NULL ) { name = if_indextoname_funcptr(ifindex, ifname); } FreeLibrary(library); } return name; } static size_t _sa_len(const struct sockaddr *addr) { if (addr->sa_family == AF_INET) return (sizeof(struct sockaddr_in)); else if (addr->sa_family == AF_INET6) return (sizeof(struct sockaddr_in6)); else return (sizeof(struct sockaddr)); } # define SA_LEN(addr) (_sa_len(addr)) #else #include // For getopt() and optind #include // For getaddrinfo() #include // For struct timeval #include // For AF_INET #include // For struct sockaddr_in() #include // For inet_addr() #include // For if_nametoindex() static const char kFilePathSep = '/'; // #ifndef NOT_HAVE_SA_LEN // #define SA_LEN(addr) ((addr)->sa_len) // #else #define SA_LEN(addr) (((addr)->sa_family == AF_INET6) ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in)) // #endif #endif #if (TEST_NEW_CLIENTSTUB && !defined(__APPLE_API_PRIVATE)) #define __APPLE_API_PRIVATE 1 #endif // DNSServiceSetDispatchQueue is not supported on 10.6 & prior #if !TEST_NEW_CLIENTSTUB && defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ - (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ % 10) <= 1060) #undef _DNS_SD_LIBDISPATCH #endif #include "dns_sd.h" #include "dns_sd_private.h" #include "ClientCommon.h" #include #if TEST_NEW_CLIENTSTUB #include "../mDNSShared/dnssd_ipc.c" #include "../mDNSShared/dnssd_clientlib.c" #include "../mDNSShared/dnssd_clientstub.c" #endif #ifndef MIN #define MIN(x, y) ((x) < (y) ? (x) : (y)) #endif //************************************************************************************************************* // Globals #define DS_FIXED_SIZE 4 typedef struct { unsigned short keyTag; unsigned char alg; unsigned char digestType; unsigned char *digest; } rdataDS; #define DNSKEY_FIXED_SIZE 4 typedef struct { unsigned short flags; unsigned char proto; unsigned char alg; unsigned char *data; } rdataDNSKey; //size of rdataRRSIG excluding signerName and signature (which are variable fields) #define RRSIG_FIXED_SIZE 18 typedef struct { unsigned short typeCovered; unsigned char alg; unsigned char labels; unsigned int origTTL; unsigned int sigExpireTime; unsigned int sigInceptTime; unsigned short keyTag; char signerName[256]; //unsigned char *signature } rdataRRSig; #define RR_TYPE_SIZE 16 typedef union { unsigned char b[2]; unsigned short NotAnInteger; } Opaque16; static int operation; static uint32_t opinterface = kDNSServiceInterfaceIndexAny; static DNSServiceRef client = NULL; static DNSServiceRef client_pa = NULL; // DNSServiceRef for RegisterProxyAddressRecord static DNSServiceRef sc1, sc2, sc3; // DNSServiceRefs for kDNSServiceFlagsShareConnection testing static int num_printed; static char addtest = 0; static DNSRecordRef record = NULL; static char myhinfoW[14] = "\002PC\012Windows XP"; static char myhinfoX[ 9] = "\003Mac\004OS X"; static char updatetest[3] = "\002AA"; static char bigNULL[8192]; // 8K is maximum rdata we support #if _DNS_SD_LIBDISPATCH dispatch_queue_t main_queue; dispatch_source_t timer_source; #endif // Note: the select() implementation on Windows (Winsock2) fails with any timeout much larger than this #define LONG_TIME 100000000 static volatile int stopNow = 0; static volatile int timeOut = LONG_TIME; #if _DNS_SD_LIBDISPATCH #define EXIT_IF_LIBDISPATCH_FATAL_ERROR(E) \ if (main_queue && (E) == kDNSServiceErr_ServiceNotRunning) { fprintf(stderr, "Error code %d\n", (E)); exit(0); } #else #define EXIT_IF_LIBDISPATCH_FATAL_ERROR(E) #endif //************************************************************************************************************* // Supporting Utility Functions static uint16_t GetRRClass(const char *s) { if (!strcasecmp(s, "IN")) return kDNSServiceClass_IN; else return(atoi(s)); } static uint16_t GetRRType(const char *s) { if (!strcasecmp(s, "A" )) return(kDNSServiceType_A); else if (!strcasecmp(s, "NS" )) return(kDNSServiceType_NS); else if (!strcasecmp(s, "MD" )) return(kDNSServiceType_MD); else if (!strcasecmp(s, "MF" )) return(kDNSServiceType_MF); else if (!strcasecmp(s, "CNAME" )) return(kDNSServiceType_CNAME); else if (!strcasecmp(s, "SOA" )) return(kDNSServiceType_SOA); else if (!strcasecmp(s, "MB" )) return(kDNSServiceType_MB); else if (!strcasecmp(s, "MG" )) return(kDNSServiceType_MG); else if (!strcasecmp(s, "MR" )) return(kDNSServiceType_MR); else if (!strcasecmp(s, "NULL" )) return(kDNSServiceType_NULL); else if (!strcasecmp(s, "WKS" )) return(kDNSServiceType_WKS); else if (!strcasecmp(s, "PTR" )) return(kDNSServiceType_PTR); else if (!strcasecmp(s, "HINFO" )) return(kDNSServiceType_HINFO); else if (!strcasecmp(s, "MINFO" )) return(kDNSServiceType_MINFO); else if (!strcasecmp(s, "MX" )) return(kDNSServiceType_MX); else if (!strcasecmp(s, "TXT" )) return(kDNSServiceType_TXT); else if (!strcasecmp(s, "RP" )) return(kDNSServiceType_RP); else if (!strcasecmp(s, "AFSDB" )) return(kDNSServiceType_AFSDB); else if (!strcasecmp(s, "X25" )) return(kDNSServiceType_X25); else if (!strcasecmp(s, "ISDN" )) return(kDNSServiceType_ISDN); else if (!strcasecmp(s, "RT" )) return(kDNSServiceType_RT); else if (!strcasecmp(s, "NSAP" )) return(kDNSServiceType_NSAP); else if (!strcasecmp(s, "NSAP_PTR")) return(kDNSServiceType_NSAP_PTR); else if (!strcasecmp(s, "SIG" )) return(kDNSServiceType_SIG); else if (!strcasecmp(s, "KEY" )) return(kDNSServiceType_KEY); else if (!strcasecmp(s, "PX" )) return(kDNSServiceType_PX); else if (!strcasecmp(s, "GPOS" )) return(kDNSServiceType_GPOS); else if (!strcasecmp(s, "AAAA" )) return(kDNSServiceType_AAAA); else if (!strcasecmp(s, "LOC" )) return(kDNSServiceType_LOC); else if (!strcasecmp(s, "NXT" )) return(kDNSServiceType_NXT); else if (!strcasecmp(s, "EID" )) return(kDNSServiceType_EID); else if (!strcasecmp(s, "NIMLOC" )) return(kDNSServiceType_NIMLOC); else if (!strcasecmp(s, "SRV" )) return(kDNSServiceType_SRV); else if (!strcasecmp(s, "ATMA" )) return(kDNSServiceType_ATMA); else if (!strcasecmp(s, "NAPTR" )) return(kDNSServiceType_NAPTR); else if (!strcasecmp(s, "KX" )) return(kDNSServiceType_KX); else if (!strcasecmp(s, "CERT" )) return(kDNSServiceType_CERT); else if (!strcasecmp(s, "A6" )) return(kDNSServiceType_A6); else if (!strcasecmp(s, "DNAME" )) return(kDNSServiceType_DNAME); else if (!strcasecmp(s, "SINK" )) return(kDNSServiceType_SINK); else if (!strcasecmp(s, "OPT" )) return(kDNSServiceType_OPT); else if (!strcasecmp(s, "TKEY" )) return(kDNSServiceType_TKEY); else if (!strcasecmp(s, "TSIG" )) return(kDNSServiceType_TSIG); else if (!strcasecmp(s, "IXFR" )) return(kDNSServiceType_IXFR); else if (!strcasecmp(s, "AXFR" )) return(kDNSServiceType_AXFR); else if (!strcasecmp(s, "MAILB" )) return(kDNSServiceType_MAILB); else if (!strcasecmp(s, "MAILA" )) return(kDNSServiceType_MAILA); else if (!strcasecmp(s, "dnskey" )) return(kDNSServiceType_DNSKEY); else if (!strcasecmp(s, "ds" )) return(kDNSServiceType_DS); else if (!strcasecmp(s, "rrsig" )) return(kDNSServiceType_RRSIG); else if (!strcasecmp(s, "nsec" )) return(kDNSServiceType_NSEC); else if (!strcasecmp(s, "SVCB" )) return(kDNSServiceType_SVCB); else if (!strcasecmp(s, "HTTPS" )) return(kDNSServiceType_HTTPS); else if (!strcasecmp(s, "ANY" )) return(kDNSServiceType_ANY); else return(atoi(s)); } static char *DNSTypeName(unsigned short rr_type) { switch (rr_type) { case kDNSServiceType_A: return("Addr"); case kDNSServiceType_NS: return("NS"); case kDNSServiceType_MD: return("MD"); case kDNSServiceType_MF: return("MF"); case kDNSServiceType_CNAME: return("CNAME"); case kDNSServiceType_SOA: return("SOA"); case kDNSServiceType_MB: return("MB"); case kDNSServiceType_MG: return("MG"); case kDNSServiceType_MR: return("MR"); case kDNSServiceType_NULL: return("NULL"); case kDNSServiceType_WKS: return("WKS"); case kDNSServiceType_PTR: return("PTR"); case kDNSServiceType_HINFO: return("HINFO"); case kDNSServiceType_MINFO: return("MINFO"); case kDNSServiceType_MX: return("MX"); case kDNSServiceType_TXT: return("TXT"); case kDNSServiceType_RP: return("RP"); case kDNSServiceType_AFSDB: return("AFSDB"); case kDNSServiceType_X25: return("X25"); case kDNSServiceType_ISDN: return("ISDN"); case kDNSServiceType_RT: return("RT"); case kDNSServiceType_NSAP: return("NSAP"); case kDNSServiceType_NSAP_PTR: return("NSAP_PTR"); case kDNSServiceType_SIG: return("SIG"); case kDNSServiceType_KEY: return("KEY"); case kDNSServiceType_PX: return("PX"); case kDNSServiceType_GPOS: return("GPOS"); case kDNSServiceType_AAAA: return("AAAA"); case kDNSServiceType_LOC: return("LOC"); case kDNSServiceType_NXT: return("NXT"); case kDNSServiceType_EID: return("EID"); case kDNSServiceType_NIMLOC: return("NIMLOC"); case kDNSServiceType_SRV: return("SRV"); case kDNSServiceType_ATMA: return("ATMA"); case kDNSServiceType_NAPTR: return("NAPTR"); case kDNSServiceType_KX: return("KX"); case kDNSServiceType_CERT: return("CERT"); case kDNSServiceType_A6: return("A6"); case kDNSServiceType_DNAME: return("DNAME"); case kDNSServiceType_SINK: return("SINK"); case kDNSServiceType_OPT: return("OPT"); case kDNSServiceType_APL: return("APL"); case kDNSServiceType_DS: return("DS"); case kDNSServiceType_SSHFP: return("SSHFP"); case kDNSServiceType_IPSECKEY: return("IPSECKEY"); case kDNSServiceType_RRSIG: return("RRSIG"); case kDNSServiceType_NSEC: return("NSEC"); case kDNSServiceType_DNSKEY: return("DNSKEY"); case kDNSServiceType_DHCID: return("DHCID"); case kDNSServiceType_NSEC3: return("NSEC3"); case kDNSServiceType_NSEC3PARAM: return("NSEC3PARAM"); case kDNSServiceType_HIP: return("HIP"); case kDNSServiceType_SPF: return("SPF"); case kDNSServiceType_UINFO: return("UINFO"); case kDNSServiceType_UID: return("UID"); case kDNSServiceType_GID: return("GID"); case kDNSServiceType_UNSPEC: return("UNSPEC"); case kDNSServiceType_TKEY: return("TKEY"); case kDNSServiceType_TSIG: return("TSIG"); case kDNSServiceType_IXFR: return("IXFR"); case kDNSServiceType_AXFR: return("AXFR"); case kDNSServiceType_MAILB: return("MAILB"); case kDNSServiceType_MAILA: return("MAILA"); case kDNSServiceType_SVCB: return("SVCB"); case kDNSServiceType_HTTPS: return("HTTPS"); case kDNSServiceType_ANY: return("ANY"); default: { static char buffer[RR_TYPE_SIZE]; snprintf(buffer, sizeof(buffer), "TYPE%d", rr_type); return(buffer); } } } static unsigned short swap16(unsigned short x) { unsigned char *ptr = (unsigned char *)&x; return (unsigned short)((unsigned short)ptr[0] << 8 | ptr[1]); } static unsigned int swap32(unsigned int x) { unsigned char *ptr = (unsigned char *)&x; return (unsigned int)((unsigned int)ptr[0] << 24 | (unsigned int)ptr[1] << 16 | (unsigned int)ptr[2] << 8 | ptr[3]); } static unsigned int keytag(unsigned char *key, unsigned int keysize) { unsigned long ac; unsigned int i; for (ac = 0, i = 0; i < keysize; ++i) ac += (i & 1) ? key[i] : key[i] << 8; ac += (ac >> 16) & 0xFFFF; return ac & 0xFFFF; } // Base 64 encoding according to . #define kBase64EncodingTable "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" static void base64Encode(char *buffer, size_t buflen, void *rdata, size_t rdlen) { const uint8_t *src = (const uint8_t *)rdata; const uint8_t *const end = &src[rdlen]; char *dst = buffer; const char *lim; if (buflen == 0) return; lim = &buffer[buflen - 1]; while ((src < end) && (dst < lim)) { uint32_t i; const size_t rem = (size_t)(end - src); // Form a 24-bit input group. If less than 24 bits remain, pad with zero bits. if ( rem >= 3) i = (src[0] << 16) | (src[1] << 8) | src[2]; // 24 bits are equal to 4 6-bit groups. else if (rem == 2) i = (src[0] << 16) | (src[1] << 8); // 16 bits are treated as 3 6-bit groups + 1 pad else i = src[0] << 16; // 8 bits are treated as 2 6-bit groups + 2 pads // Encode each 6-bit group. *dst++ = kBase64EncodingTable[(i >> 18) & 0x3F]; if (dst < lim) *dst++ = kBase64EncodingTable[(i >> 12) & 0x3F]; if (dst < lim) *dst++ = (rem >= 2) ? kBase64EncodingTable[(i >> 6) & 0x3F] : '='; if (dst < lim) *dst++ = (rem >= 3) ? kBase64EncodingTable[ i & 0x3F] : '='; src += (rem > 3) ? 3 : rem; } *dst = '\0'; } static DNSServiceProtocol GetProtocol(const char *s) { if (!strcasecmp(s, "v4" )) return(kDNSServiceProtocol_IPv4); else if (!strcasecmp(s, "v6" )) return(kDNSServiceProtocol_IPv6); else if (!strcasecmp(s, "v4v6" )) return(kDNSServiceProtocol_IPv4 | kDNSServiceProtocol_IPv6); else if (!strcasecmp(s, "v6v4" )) return(kDNSServiceProtocol_IPv4 | kDNSServiceProtocol_IPv6); else if (!strcasecmp(s, "udp" )) return(kDNSServiceProtocol_UDP); else if (!strcasecmp(s, "tcp" )) return(kDNSServiceProtocol_TCP); else if (!strcasecmp(s, "udptcp" )) return(kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP); else if (!strcasecmp(s, "tcpudp" )) return(kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP); else return(atoi(s)); } //************************************************************************************************************* // Sample callback functions for each of the operation types #define printtimestamp() printtimestamp_F(stdout) static void printtimestamp_F(FILE *outstream) { struct tm tm; int ms; static char date[16]; static char new_date[16]; #ifdef _WIN32 SYSTEMTIME sysTime; time_t uct = time(NULL); tm = *localtime(&uct); GetLocalTime(&sysTime); ms = sysTime.wMilliseconds; #else struct timeval tv; gettimeofday(&tv, NULL); localtime_r((time_t*)&tv.tv_sec, &tm); ms = tv.tv_usec/1000; #endif strftime(new_date, sizeof(new_date), "%a %d %b %Y", &tm); if (strncmp(date, new_date, sizeof(new_date))) { fprintf(outstream, "DATE: ---%s---\n", new_date); //display date only if it has changed strncpy(date, new_date, sizeof(date)); } fprintf(outstream, "%2d:%02d:%02d.%03d ", tm.tm_hour, tm.tm_min, tm.tm_sec, ms); } // formating time to RFC 4034 format static void FormatTime(unsigned long te, unsigned char *buf, int bufsize) { struct tm tmTime; #ifdef _WIN32 __time32_t t = (__time32_t) te; _gmtime32_s(&tmTime, &t); #else // Time since epoch : strftime takes "tm". Convert seconds to "tm" using // gmtime_r first and then use strftime time_t t = (time_t)te; gmtime_r(&t, &tmTime); #endif strftime((char *)buf, bufsize, "%Y%m%d%H%M%S", &tmTime); } static void print_usage(const char *arg0, int print_all) { // Print the commonly used command line options. These are listed in "the order they have been in historically". fprintf(stderr, "%s -E (Enumerate recommended registration domains)\n", arg0); fprintf(stderr, "%s -F (Enumerate recommended browsing domains)\n", arg0); fprintf(stderr, "%s -R [...] (Register a service)\n", arg0); fprintf(stderr, "%s -P [...] (Register Proxy)\n", arg0); fprintf(stderr, "%s -B (Browse for service instances)\n", arg0); fprintf(stderr, "%s -Z (Output results in Zone File format)\n", arg0); fprintf(stderr, "%s -L (Resolve (‘lookup’) a service instance)\n", arg0); fprintf(stderr, "%s -Q (Generic query for any record type)\n", arg0); fprintf(stderr, "%s -q (Generic query, using SuppressUnusable)\n", arg0); fprintf(stderr, "%s -G v4/v6/v4v6 (Get address information for hostname)\n", arg0); fprintf(stderr, "%s -X udp/tcp/udptcp (NAT Port Mapping)\n", arg0); fprintf(stderr, "%s -H (Print usage for complete command list)\n", arg0); fprintf(stderr, "%s -V (Get version of currently running daemon / system service)\n", arg0); #ifdef APPLE_OSX_mDNSResponder fprintf(stderr, "%s -O [-compress|-stdout](Dump the state of mDNSResponder to file / STDOUT)\n", arg0); #endif // APPLE_OSX_mDNSResponder if (print_all) // Print all available options for dns-sd tool. Keep these in alphabetical order for easier maintenance. { fprintf(stderr, "\n"); fprintf(stderr, "%s -A (Test Adding/Updating/Deleting a record)\n", arg0); fprintf(stderr, "%s -C (Query; reconfirming each result)\n", arg0); fprintf(stderr, "%s -I (Test registering and then immediately updating TXT record)\n", arg0); fprintf(stderr, "%s -N (Test adding a large NULL record)\n", arg0); fprintf(stderr, "%s -M (Test creating a registration with multiple TXT records)\n", arg0); fprintf(stderr, "%s -S (Test multiple operations on a shared socket)\n", arg0); fprintf(stderr, "%s -T (Test creating a large TXT record)\n", arg0); fprintf(stderr, "%s -U (Test updating a TXT record)\n", arg0); fprintf(stderr, "%s -ble (Use kDNSServiceInterfaceIndexBLE)\n", arg0); fprintf(stderr, "%s -i (Run dns-sd cmd on a specific interface (en0/en1)\n", arg0); fprintf(stderr, "%s -includep2p (Set kDNSServiceFlagsIncludeP2P flag)\n", arg0); fprintf(stderr, "%s -includeAWDL (Set kDNSServiceFlagsIncludeAWDL flag)\n", arg0); fprintf(stderr, "%s -intermediates (Set kDNSServiceFlagsReturnIntermediates flag)\n", arg0); fprintf(stderr, "%s -ku (Set kDNSServiceFlagsKnownUnique flag)\n", arg0); fprintf(stderr, "%s -lo (Run dns-sd cmd using local only interface)\n", arg0); fprintf(stderr, "%s -p2p (Use kDNSServiceInterfaceIndexP2P)\n", arg0); fprintf(stderr, "%s -tc (Set kDNSServiceFlagsBackgroundTrafficClass flag)\n", arg0); fprintf(stderr, "%s -test (Run basic API input range tests)\n", arg0); fprintf(stderr, "%s -t1 (Set kDNSServiceFlagsThresholdOne flag)\n", arg0); fprintf(stderr, "%s -tFinder (Set kDNSServiceFlagsThresholdFinder flag)\n", arg0); fprintf(stderr, "%s -timeout (Set kDNSServiceFlagsTimeout flag)\n", arg0); fprintf(stderr, "%s -unicastResponse (Set kDNSServiceFlagsUnicastResponse flag)\n", arg0); fprintf(stderr, "%s -autoTrigger (Set kDNSServiceFlagsAutoTrigger flag)\n", arg0); fprintf(stderr, "%s -enableDNSSEC (Enable DNSSEC validation for the '-Q' query)\n", arg0); } } #define DomainMsg(X) (((X) &kDNSServiceFlagsDefault) ? "(Default)" : \ ((X) &kDNSServiceFlagsAdd) ? "Added" : "Removed") #define MAX_LABELS 128 static void DNSSD_API enum_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode, const char *replyDomain, void *context) { DNSServiceFlags partialflags = flags & ~(kDNSServiceFlagsMoreComing | kDNSServiceFlagsAdd | kDNSServiceFlagsDefault); int labels = 0, depth = 0, i, initial = 0; char text[64]; const char *label[MAX_LABELS]; (void)sdref; // Unused (void)ifIndex; // Unused (void)context; // Unused EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); // 1. Print the header if (num_printed++ == 0) printf("Timestamp Recommended %s domain\n", operation == 'E' ? "Registration" : "Browsing"); printtimestamp(); if (errorCode) printf("Error code %d\n", errorCode); else if (!*replyDomain) printf("Error: No reply domain\n"); else { printf("%-10s", DomainMsg(flags)); printf("%-8s", (flags & kDNSServiceFlagsMoreComing) ? "(More)" : ""); if (partialflags) printf("Flags: %4X ", partialflags); else printf(" "); // 2. Count the labels while (replyDomain && *replyDomain && labels < MAX_LABELS) { label[labels++] = replyDomain; replyDomain = GetNextLabel(replyDomain, text); } // 3. Decide if we're going to clump the last two or three labels (e.g. "apple.com", or "nicta.com.au") if (labels >= 3 && replyDomain - label[labels-1] <= 3 && label[labels-1] - label[labels-2] <= 4) initial = 3; else if (labels >= 2 && replyDomain - label[labels-1] <= 4) initial = 2; else initial = 1; labels -= initial; // 4. Print the initial one-, two- or three-label clump for (i=0; i0) printf("."); printf("%s", text); } printf("\n"); // 5. Print the remainder of the hierarchy for (depth=0; depth %s\n", text); } } if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } static int CopyLabels(char *dst, const char *lim, const char **srcp, int labels) { const char *src = *srcp; while (*src != '.' || --labels > 0) { if (*src == '\\') *dst++ = *src++; // Make sure "\." doesn't confuse us if (!*src || dst >= lim) return -1; *dst++ = *src++; if (!*src || dst >= lim) return -1; } *dst++ = 0; *srcp = src + 1; // skip over final dot return 0; } static void DNSSD_API zonedata_resolve(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t opaqueport, uint16_t txtLen, const unsigned char *txt, void *context) { union { uint16_t s; u_char b[2]; } port = { opaqueport }; uint16_t PortAsNumber = ((uint16_t)port.b[0]) << 8 | port.b[1]; const char *p = fullname; char n[kDNSServiceMaxDomainName]; char t[kDNSServiceMaxDomainName]; const unsigned char *max = txt + txtLen; (void)sdref; // Unused (void)ifIndex; // Unused (void)context; // Unused //if (!(flags & kDNSServiceFlagsAdd)) return; if (errorCode) { printf("Error code %d\n", errorCode); return; } if (CopyLabels(n, n + kDNSServiceMaxDomainName, &p, 3)) return; // Fetch name+type p = fullname; if (CopyLabels(t, t + kDNSServiceMaxDomainName, &p, 1)) return; // Skip first label if (CopyLabels(t, t + kDNSServiceMaxDomainName, &p, 2)) return; // Fetch next two labels (service type) if (num_printed++ == 0) { printf("\n"); printf("; To direct clients to browse a different domain, substitute that domain in place of '@'\n"); printf("%-47s PTR %s\n", "lb._dns-sd._udp", "@"); printf("\n"); printf("; In the list of services below, the SRV records will typically reference dot-local Multicast DNS names.\n"); printf("; When transferring this zone file data to your unicast DNS server, you'll need to replace those dot-local\n"); printf("; names with the correct fully-qualified (unicast) domain name of the target host offering the service.\n"); } printf("\n"); printf("%-47s PTR %s\n", t, n); printf("%-47s SRV 0 0 %d %s ; Replace with unicast FQDN of target host\n", n, PortAsNumber, hosttarget); printf("%-47s TXT ", n); while (txt < max) { const unsigned char *const end = txt + 1 + txt[0]; txt++; // Skip over length byte printf(" \""); while (txt max) { printf("<< invalid data >>"); break; } if (++ptr < end) printf(" "); // As long as string is non-empty, begin with a space while (ptr^()[]{}$", *ptr)) printf("\\"); if (*ptr == '\\') printf("\\\\\\\\"); else if (*ptr >= ' ' ) printf("%c", *ptr); else printf("\\\\x%02X", *ptr); ptr++; } } } static void DNSSD_API resolve_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t opaqueport, uint16_t txtLen, const unsigned char *txtRecord, void *context) { union { uint16_t s; u_char b[2]; } port = { opaqueport }; uint16_t PortAsNumber = ((uint16_t)port.b[0]) << 8 | port.b[1]; (void)sdref; // Unused (void)ifIndex; // Unused (void)context; // Unused EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); printtimestamp(); printf("%s ", fullname); if (errorCode == kDNSServiceErr_NoSuchRecord) printf("No Such Record"); else if (errorCode) printf("error code %d\n", errorCode); else printf("can be reached at %s:%u (interface %d)", hosttarget, PortAsNumber, ifIndex); if (flags) printf(" Flags: %X", flags); // Don't show degenerate TXT records containing nothing but a single empty string if (!errorCode && txtLen > 1) { printf("\n"); ShowTXTRecord(txtLen, txtRecord); } printf("\n"); if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } static void myTimerCallBack(void) { DNSServiceErrorType err = kDNSServiceErr_Unknown; switch (operation) { case 'A': { switch (addtest) { case 0: printf("Adding Test HINFO record\n"); err = DNSServiceAddRecord(client, &record, 0, kDNSServiceType_HINFO, sizeof(myhinfoW), &myhinfoW[0], 0); addtest = 1; break; case 1: printf("Updating Test HINFO record\n"); err = DNSServiceUpdateRecord(client, record, 0, sizeof(myhinfoX), &myhinfoX[0], 0); addtest = 2; break; case 2: printf("Removing Test HINFO record\n"); err = DNSServiceRemoveRecord(client, record, 0); addtest = 0; break; } } break; case 'U': { if (updatetest[1] != 'Z') updatetest[1]++; else updatetest[1] = 'A'; // The following line toggles the string length between 1 and 2 characters. updatetest[0] = 3 - updatetest[0]; updatetest[2] = updatetest[1]; printtimestamp(); printf("Updating Test TXT record to %c\n", updatetest[1]); err = DNSServiceUpdateRecord(client, NULL, 0, 1+updatetest[0], &updatetest[0], 0); } break; case 'N': { printf("Adding big NULL record\n"); err = DNSServiceAddRecord(client, &record, 0, kDNSServiceType_NULL, sizeof(bigNULL), &bigNULL[0], 0); if (err) printf("Failed: %d\n", err);else printf("Succeeded\n"); timeOut = LONG_TIME; #if _DNS_SD_LIBDISPATCH if (timer_source) dispatch_source_set_timer(timer_source, dispatch_time(DISPATCH_TIME_NOW, (uint64_t)timeOut * NSEC_PER_SEC), (uint64_t)timeOut * NSEC_PER_SEC, 0); #endif } break; } if (err != kDNSServiceErr_NoError) { fprintf(stderr, "DNSService add/update/remove failed %ld\n", (long int)err); stopNow = 1; } } static void DNSSD_API reg_reply(DNSServiceRef sdref, const DNSServiceFlags flags, DNSServiceErrorType errorCode, const char *name, const char *regtype, const char *domain, void *context) { (void)sdref; // Unused (void)flags; // Unused (void)context; // Unused EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); printtimestamp(); printf("Got a reply for service %s.%s%s: ", name, regtype, domain); if (errorCode == kDNSServiceErr_NoError) { if (flags & kDNSServiceFlagsAdd) printf("Name now registered and active\n"); else printf("Name registration removed\n"); if (operation == 'A' || operation == 'U' || operation == 'N') { timeOut = 5; #if _DNS_SD_LIBDISPATCH if (timer_source) dispatch_source_set_timer(timer_source, dispatch_time(DISPATCH_TIME_NOW, (uint64_t)timeOut * NSEC_PER_SEC), (uint64_t)timeOut * NSEC_PER_SEC, 0); #endif } } else if (errorCode == kDNSServiceErr_NameConflict) { printf("Name in use, please choose another\n"); exit(-1); } else printf("Error %d\n", errorCode); if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } static int snprintf_safe(char *str, size_t size, const char *format, ...) { int length = 0; va_list ptr; va_start(ptr, format); int result = vsnprintf(str, size, format, ptr); va_end(ptr); if (result > 0 && size > 0) { length = MIN((size_t)result, size-1); } return length; } // Output the wire-format domainname pointed to by rd static int snprintd(char *p, int max, const unsigned char **rd) { const char *const buf = p; const char *const end = p + max; while (**rd) { p += snprintf_safe(p, end-p, "%.*s.", **rd, *rd+1); *rd += 1 + **rd; } *rd += 1; // Advance over the final zero byte return(p-buf); } static void ParseDNSSECRecords(uint16_t rrtype, char *rdb, size_t rdb_size, unsigned const char *rd, uint16_t rdlen) { char *p = rdb; switch (rrtype) { case kDNSServiceType_DS: { unsigned char *ptr; int i; rdataDS *rrds = (rdataDS *)rd; p += snprintf_safe(p, rdb + rdb_size - p, "%d %d %d ", rrds->alg, swap16(rrds->keyTag), rrds->digestType); ptr = (unsigned char *)(rd + DS_FIXED_SIZE); for (i = 0; i < (rdlen - DS_FIXED_SIZE); i++) p += snprintf_safe(p, rdb + rdb_size - p, "%x", ptr[i]); break; } case kDNSServiceType_DNSKEY: { rdataDNSKey *rrkey = (rdataDNSKey *)rd; p += snprintf_safe(p, rdb + rdb_size - p, "%d %d %d %u ", swap16(rrkey->flags), rrkey->proto, rrkey->alg, (unsigned int)keytag((unsigned char *)rrkey, rdlen)); base64Encode(p, rdb + rdb_size - p, (unsigned char *)(rd + DNSKEY_FIXED_SIZE), rdlen - DNSKEY_FIXED_SIZE); break; } case kDNSServiceType_NSEC: { unsigned char *next = (unsigned char *)rd; int len, bitmaplen; int win, wlen, type; unsigned char *bmap; char *l = NULL; l = p; p += snprintd(p, rdb + rdb_size - p, &rd); len = p - l + 1; bitmaplen = rdlen - len; bmap = (unsigned char *)((unsigned char *)next + len); while (bitmaplen > 0) { int i; if (bitmaplen < 3) { printf("Case NSEC: malformed nsec, bitmaplen %d short\n", bitmaplen); break; } win = *bmap++; wlen = *bmap++; bitmaplen -= 2; if (bitmaplen < wlen || wlen < 1 || wlen > 32) { printf("Case NSEC: malformed nsec, bitmaplen %d wlen %d\n", bitmaplen, wlen); break; } if (win < 0 || win >= 256) { printf("Case NSEC: malformed nsec, bad window win %d\n", win); break; } type = win * 256; for (i = 0; i < wlen * 8; i++) { if (bmap[i>>3] & (128 >> (i&7))) p += snprintf_safe(p, rdb + rdb_size - p, " %s ", DNSTypeName(type + i)); } bmap += wlen; bitmaplen -= wlen; } break; } case kDNSServiceType_RRSIG: { rdataRRSig *rrsig = (rdataRRSig *)rd; unsigned char expTimeBuf[64]; unsigned char inceptTimeBuf[64]; unsigned long inceptClock; unsigned long expClock; const unsigned char *q = NULL; char *k = NULL; int len; expClock = (unsigned long)swap32(rrsig->sigExpireTime); FormatTime(expClock, expTimeBuf, sizeof(expTimeBuf)); inceptClock = (unsigned long)swap32(rrsig->sigInceptTime); FormatTime(inceptClock, inceptTimeBuf, sizeof(inceptTimeBuf)); p += snprintf_safe(p, rdb + rdb_size - p, " %-7s %d %d %d %s %s %7d ", DNSTypeName(swap16(rrsig->typeCovered)), rrsig->alg, rrsig->labels, swap32(rrsig->origTTL), expTimeBuf, inceptTimeBuf, swap16(rrsig->keyTag)); q = (const unsigned char *)&rrsig->signerName; k = p; p += snprintd(p, rdb + rdb_size - p, &q); len = p - k + 1; if ((&rdb[rdb_size] - p) >= 2) { *p++ = ' '; *p = '\0'; } base64Encode(p, rdb + rdb_size - p, (unsigned char *)(rd + len + RRSIG_FIXED_SIZE), rdlen - (len + RRSIG_FIXED_SIZE)); break; } } return; } static void DNSSD_API qr_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, void *context) { char *op = (flags & kDNSServiceFlagsAdd) ? "Add" : "Rmv"; const unsigned char *rd = rdata; const unsigned char *end = (const unsigned char *) rdata + rdlen; char rdb[1000] = "0.0.0.0", *p = rdb; int unknowntype = 0; char dnssec_status[15] = "Unknown"; char rr_type[RR_TYPE_SIZE]; char rr_class[6]; DNSServiceFlags check_flags = flags;//local flags for dnssec status checking int8_t enable_dnssec = ((check_flags & kDNSServiceFlagsEnableDNSSEC) != 0); static int8_t enabled_dnssec_before = -1; if (enabled_dnssec_before == -1) { enabled_dnssec_before = enable_dnssec; } (void)sdref; // Unused (void)ifIndex; // Unused (void)ttl; // Unused (void)context; // Unused EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); if (num_printed++ == 0) { printf("Timestamp A/R Flags if %-30s%-6s%-7s%s Rdata\n", "Name", "Type", "Class", enable_dnssec ? " DNSSECResult " : ""); } printtimestamp(); switch (rrclass) { case kDNSServiceClass_IN: strncpy(rr_class, "IN", sizeof(rr_class)); break; default: snprintf(rr_class, sizeof(rr_class), "%d", rrclass); break; } strncpy(rr_type, DNSTypeName(rrtype), sizeof(rr_type)); if (!errorCode) //to avoid printing garbage in rdata { switch (rrtype) { case kDNSServiceType_A: snprintf_safe(rdb, sizeof(rdb), "%d.%d.%d.%d", rd[0], rd[1], rd[2], rd[3]); break; case kDNSServiceType_NS: case kDNSServiceType_CNAME: case kDNSServiceType_PTR: case kDNSServiceType_DNAME: snprintd(p, sizeof(rdb), &rd); break; case kDNSServiceType_SOA: p += snprintd(p, rdb + sizeof(rdb) - p, &rd); // mname p += snprintf_safe(p, rdb + sizeof(rdb) - p, " "); p += snprintd(p, rdb + sizeof(rdb) - p, &rd); // rname snprintf(p, rdb + sizeof(rdb) - p, " Ser %d Ref %d Ret %d Exp %d Min %d", ntohl(((uint32_t*)rd)[0]), ntohl(((uint32_t*)rd)[1]), ntohl(((uint32_t*)rd)[2]), ntohl(((uint32_t*)rd)[3]), ntohl(((uint32_t*)rd)[4])); break; case kDNSServiceType_AAAA: snprintf(rdb, sizeof(rdb), "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X", rd[0x0], rd[0x1], rd[0x2], rd[0x3], rd[0x4], rd[0x5], rd[0x6], rd[0x7], rd[0x8], rd[0x9], rd[0xA], rd[0xB], rd[0xC], rd[0xD], rd[0xE], rd[0xF]); break; case kDNSServiceType_SRV: p += snprintf_safe(p, rdb + sizeof(rdb) - p, "%d %d %d ", // priority, weight, port ntohs(*(unsigned short*)rd), ntohs(*(unsigned short*)(rd+2)), ntohs(*(unsigned short*)(rd+4))); rd += 6; snprintd(p, rdb + sizeof(rdb) - p, &rd); // target host break; case kDNSServiceType_DS: case kDNSServiceType_DNSKEY: case kDNSServiceType_NSEC: case kDNSServiceType_RRSIG: ParseDNSSECRecords(rrtype, rdb, sizeof(rdb), rd, rdlen); break; default: snprintf(rdb, sizeof(rdb), "%d bytes%s", rdlen, rdlen ? ":" : ""); unknowntype = 1; break; } } if (check_flags & kDNSServiceFlagsSecure) strncpy(dnssec_status, "Secure ", sizeof(dnssec_status)); else if (check_flags & kDNSServiceFlagsInsecure) strncpy(dnssec_status, "Insecure ", sizeof(dnssec_status)); else if (check_flags & kDNSServiceFlagsIndeterminate) strncpy(dnssec_status, "Indeterminate ", sizeof(dnssec_status)); else if (check_flags & kDNSServiceFlagsBogus) strncpy(dnssec_status, "Bogus ", sizeof(dnssec_status)); else strncpy(dnssec_status, " ", sizeof(dnssec_status)); printf("%s%9X%3d %-30s%-7s%-6s %s%s", op, flags, ifIndex, fullname, rr_type, rr_class, enabled_dnssec_before ? dnssec_status : "", rdb); if (unknowntype) { while (rd < end) printf(" %02X", *rd++); } if (errorCode) { if (errorCode == kDNSServiceErr_NoSuchRecord) printf(" No Such Record"); else if (errorCode == kDNSServiceErr_NoAuth) printf(" No Authorization"); else if (errorCode == kDNSServiceErr_Timeout) { printf(" No Such Record\n"); printf("Query Timed Out\n"); exit(1); } } printf("\n"); if (operation == 'C') if (flags & kDNSServiceFlagsAdd) DNSServiceReconfirmRecord(flags, ifIndex, fullname, rrtype, rrclass, rdlen, rdata); if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } static void DNSSD_API port_mapping_create_reply(DNSServiceRef sdref, DNSServiceFlags flags, uint32_t ifIndex, DNSServiceErrorType errorCode, uint32_t publicAddress, uint32_t protocol, uint16_t privatePort, uint16_t publicPort, uint32_t ttl, void *context) { (void)sdref; // Unused (void)flags; // Unused (void)context; // Unused EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); if (num_printed++ == 0) printf("Timestamp if %-20s %-15s %-15s %-15s %-6s\n", "External Address", "Protocol", "Internal Port", "External Port", "TTL"); printtimestamp(); if (errorCode && errorCode != kDNSServiceErr_DoubleNAT) printf("Error code %d\n", errorCode); else { const unsigned char *digits = (const unsigned char *)&publicAddress; char addr[256]; snprintf(addr, sizeof(addr), "%d.%d.%d.%d", digits[0], digits[1], digits[2], digits[3]); printf("%-4d %-20s %-15d %-15d %-15d %-6d%s\n", ifIndex, addr, protocol, ntohs(privatePort), ntohs(publicPort), ttl, errorCode == kDNSServiceErr_DoubleNAT ? " Double NAT" : ""); } if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } static void DNSSD_API addrinfo_reply(DNSServiceRef sdref, const DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *hostname, const struct sockaddr *address, uint32_t ttl, void *context) { char *op = (flags & kDNSServiceFlagsAdd) ? "Add" : "Rmv"; char addr[256] = ""; char dnssec_status[15] = "Unknown"; DNSServiceFlags check_flags = flags; (void) sdref; (void) context; unsigned char enable_dnssec = ((check_flags & kDNSServiceFlagsEnableDNSSEC) != 0); EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); if (num_printed++ == 0) { printf("Timestamp A/R Flags if %-38s %-44s %s%s\n", "Hostname", "Address", "TTL", enable_dnssec ? "DNSSECResult" : ""); } printtimestamp(); if (address && address->sa_family == AF_INET) { const unsigned char *b = (const unsigned char *) &((struct sockaddr_in *)address)->sin_addr; snprintf(addr, sizeof(addr), "%d.%d.%d.%d", b[0], b[1], b[2], b[3]); } else if (address && address->sa_family == AF_INET6) { char if_name[IFNAMSIZ]; // Older Linux distributions don't define IF_NAMESIZE const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *)address; const unsigned char *b = (const unsigned char * )&s6->sin6_addr; if (!if_indextoname(s6->sin6_scope_id, if_name)) snprintf(if_name, sizeof(if_name), "<%d>", s6->sin6_scope_id); snprintf(addr, sizeof(addr), "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X%%%s", b[0x0], b[0x1], b[0x2], b[0x3], b[0x4], b[0x5], b[0x6], b[0x7], b[0x8], b[0x9], b[0xA], b[0xB], b[0xC], b[0xD], b[0xE], b[0xF], if_name); } if (enable_dnssec) { if (check_flags & kDNSServiceFlagsSecure) strncpy(dnssec_status, " Secure", sizeof(dnssec_status)); else if (check_flags & kDNSServiceFlagsInsecure) strncpy(dnssec_status, " Insecure", sizeof(dnssec_status)); else if (check_flags & kDNSServiceFlagsIndeterminate) strncpy(dnssec_status, " Indeterminate", sizeof(dnssec_status)); else if (check_flags & kDNSServiceFlagsBogus) strncpy(dnssec_status, " Bogus", sizeof(dnssec_status)); } printf("%s%9X%3d %-38s %-44s %d%s", op, flags, interfaceIndex, hostname, addr, ttl, enable_dnssec ? dnssec_status : ""); if (errorCode) { if (errorCode == kDNSServiceErr_NoSuchRecord) printf(" No Such Record"); else printf(" Error code %d", errorCode); } printf("\n"); if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } //************************************************************************************************************* // The main test function static void HandleEvents(void) #if _DNS_SD_LIBDISPATCH { main_queue = dispatch_get_main_queue(); if (client) DNSServiceSetDispatchQueue(client, main_queue); if (client_pa) DNSServiceSetDispatchQueue(client_pa, main_queue); if (operation == 'A' || operation == 'U' || operation == 'N') { timer_source = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, main_queue); if (timer_source) { // Start the timer "timeout" seconds into the future and repeat it every "timeout" seconds dispatch_source_set_timer(timer_source, dispatch_time(DISPATCH_TIME_NOW, (uint64_t)timeOut * NSEC_PER_SEC), (uint64_t)timeOut * NSEC_PER_SEC, 0); dispatch_source_set_event_handler(timer_source, ^{myTimerCallBack();}); dispatch_resume(timer_source); } } dispatch_main(); } #else { int dns_sd_fd = client ? DNSServiceRefSockFD(client ) : -1; int dns_sd_fd2 = client_pa ? DNSServiceRefSockFD(client_pa) : -1; int nfds = dns_sd_fd + 1; fd_set readfds; struct timeval tv; int result; if (dns_sd_fd2 > dns_sd_fd) nfds = dns_sd_fd2 + 1; while (!stopNow) { // 1. Set up the fd_set as usual here. // This example client has no file descriptors of its own, // but a real application would call FD_SET to add them to the set here FD_ZERO(&readfds); // 2. Add the fd for our client(s) to the fd_set if (client ) FD_SET(dns_sd_fd, &readfds); if (client_pa) FD_SET(dns_sd_fd2, &readfds); // 3. Set up the timeout. tv.tv_sec = timeOut; tv.tv_usec = 0; result = select(nfds, &readfds, (fd_set*)NULL, (fd_set*)NULL, &tv); if (result > 0) { DNSServiceErrorType err = kDNSServiceErr_NoError; if (client && FD_ISSET(dns_sd_fd, &readfds)) err = DNSServiceProcessResult(client ); else if (client_pa && FD_ISSET(dns_sd_fd2, &readfds)) err = DNSServiceProcessResult(client_pa); if (err) { printtimestamp_F(stderr); fprintf(stderr, "DNSServiceProcessResult returned %d\n", err); stopNow = 1; } } else if (result == 0) myTimerCallBack(); else { printf("select() returned %d errno %d %s\n", result, errno, strerror(errno)); if (errno != EINTR) stopNow = 1; } } } #endif static int getfirstoption(int argc, char **argv, const char *optstr, int *pOptInd) // Return the recognized option in optstr and the option index of the next arg. #if NOT_HAVE_GETOPT { int i; for (i=1; i < argc; i++) { if (argv[i][0] == '-' && &argv[i][1] && NULL != strchr(optstr, argv[i][1])) { *pOptInd = i + 1; return argv[i][1]; } } return -1; } #else { int o = getopt(argc, (char *const *)argv, optstr); *pOptInd = optind; return o; } #endif static void DNSSD_API MyRegisterRecordCallback(DNSServiceRef service, DNSRecordRef rec, const DNSServiceFlags flags, DNSServiceErrorType errorCode, void *context) { char *name = (char *)context; (void)service; // Unused (void)rec; // Unused (void)flags; // Unused EXIT_IF_LIBDISPATCH_FATAL_ERROR(errorCode); printtimestamp(); printf("Got a reply for record %s: ", name); switch (errorCode) { case kDNSServiceErr_NoError: printf("Name now registered and active\n"); break; case kDNSServiceErr_NameConflict: printf("Name in use, please choose another\n"); exit(-1); default: printf("Error %d\n", errorCode); break; } if (!(flags & kDNSServiceFlagsMoreComing)) fflush(stdout); } static void getip(const char *const name, struct sockaddr_storage *result) { struct addrinfo *addrs = NULL; int err = getaddrinfo(name, NULL, NULL, &addrs); if (err) fprintf(stderr, "getaddrinfo error %d for %s", err, name); else memcpy(result, addrs->ai_addr, SA_LEN(addrs->ai_addr)); if (addrs) freeaddrinfo(addrs); } static DNSServiceErrorType RegisterProxyAddressRecord(DNSServiceRef sdref, const char *host, const char *ip, DNSServiceFlags flags) { // Call getip() after the call DNSServiceCreateConnection(). // On the Win32 platform, WinSock must be initialized for getip() to succeed. // Any DNSService* call will initialize WinSock for us, so we make sure // DNSServiceCreateConnection() is called before getip() is. struct sockaddr_storage hostaddr; memset(&hostaddr, 0, sizeof(hostaddr)); getip(ip, &hostaddr); flags |= kDNSServiceFlagsUnique; if (hostaddr.ss_family == AF_INET) return(DNSServiceRegisterRecord(sdref, &record, flags, opinterface, host, kDNSServiceType_A, kDNSServiceClass_IN, 4, &((struct sockaddr_in *)&hostaddr)->sin_addr, 240, MyRegisterRecordCallback, (void*)host)); else if (hostaddr.ss_family == AF_INET6) return(DNSServiceRegisterRecord(sdref, &record, flags, opinterface, host, kDNSServiceType_AAAA, kDNSServiceClass_IN, 16, &((struct sockaddr_in6*)&hostaddr)->sin6_addr, 240, MyRegisterRecordCallback, (void*)host)); else return(kDNSServiceErr_BadParam); } #define HexVal(X) ( ((X) >= '0' && (X) <= '9') ? ((X) - '0' ) : \ ((X) >= 'A' && (X) <= 'F') ? ((X) - 'A' + 10) : \ ((X) >= 'a' && (X) <= 'f') ? ((X) - 'a' + 10) : 0) #define HexPair(P) ((HexVal((P)[0]) << 4) | HexVal((P)[1])) #define MAXTXTRecordSize 8900 static DNSServiceErrorType RegisterService(DNSServiceRef *sdref, const char *nam, const char *typ, const char *dom, const char *host, const char *port, int argc, char **argv, DNSServiceFlags flags) { uint16_t PortAsNumber = atoi(port); Opaque16 registerPort = { { PortAsNumber >> 8, PortAsNumber & 0xFF } }; unsigned char txt[MAXTXTRecordSize]; txt[0] = '\0'; unsigned char *ptr = txt; int i; if (nam[0] == '.' && nam[1] == 0) nam = ""; // We allow '.' on the command line as a synonym for empty string if (dom[0] == '.' && dom[1] == 0) dom = ""; // We allow '.' on the command line as a synonym for empty string printf("Registering Service %s.%s%s%s", nam[0] ? nam : "<>", typ, dom[0] ? "." : "", dom); if (host && *host) printf(" host %s", host); printf(" port %s", port); if (argc) { for (i = 0; i < argc; i++) { const char *p = argv[i]; if (ptr >= txt + sizeof(txt)) return kDNSServiceErr_BadParam; *ptr = 0; while (*p && *ptr < 255) { if (ptr + 1 + *ptr >= txt + sizeof(txt)) return kDNSServiceErr_BadParam; if (p[0] != '\\' || p[1] == 0) { ptr[++*ptr] = *p; p+=1; } else if (p[1] == 'x' && isxdigit(p[2]) && isxdigit(p[3])) { ptr[++*ptr] = HexPair(p+2); p+=4; } else { ptr[++*ptr] = p[1]; p+=2; } } ptr += 1 + *ptr; } printf(" TXT"); ShowTXTRecord(ptr-txt, txt); } printf("\n"); //flags |= kDNSServiceFlagsAllowRemoteQuery; //flags |= kDNSServiceFlagsNoAutoRename; return(DNSServiceRegister(sdref, flags, opinterface, nam, typ, dom, host, registerPort.NotAnInteger, (uint16_t) (ptr-txt), txt, reg_reply, NULL)); } #define TypeBufferSize 80 static char *gettype(char *buffer, char *typ) { if (!typ || !*typ || (typ[0] == '.' && typ[1] == 0)) typ = "_http._tcp"; if (!strchr(typ, '.')) { snprintf(buffer, TypeBufferSize, "%s._tcp", typ); typ = buffer; } return(typ); } // Do some basic tests to verify API handles > 63 byte strings gracefully with // a returned error code. #define STRING_64_BYTES "_123456789012345678901234567890123456789012345678901234567890123" static int API_string_limit_test() { const char * regtype; DNSServiceRef sdRef = NULL; const char * longHost = STRING_64_BYTES ".local"; const char * longDomain = "hostname." STRING_64_BYTES; printf("Testing for error returns when various strings are > 63 bytes.\n"); printf("DNSServiceGetAddrInfo(), hostname = %s\n", longHost); if (DNSServiceGetAddrInfo(&sdRef, 0, 0, 0, longHost, addrinfo_reply, 0) == 0) { printf("DNSServiceGetAddrInfo(): expected error return\n"); return 1; }; printf("DNSServiceGetAddrInfo(), hostname = %s\n", longDomain); if (DNSServiceGetAddrInfo(&sdRef, 0, 0, 0, longDomain, addrinfo_reply, 0) == 0) { printf("DNSServiceGetAddrInfo(): expected error return\n"); return 1; }; printf("DNSServiceResolve(), name = %s\n", STRING_64_BYTES); if (DNSServiceResolve(&sdRef, 0, 0, STRING_64_BYTES, "_test._tcp", "local", resolve_reply, NULL) == 0) { printf("DNSServiceResolve(): expected error return\n"); return 1; }; regtype = STRING_64_BYTES "._tcp"; printf("DNSServiceResolve(), regtype = %s\n", regtype); if (DNSServiceResolve(&sdRef, 0, 0, "instanceName", regtype, "local", resolve_reply, NULL) == 0) { printf("DNSServiceResolve(): expected error return\n"); return 1; }; printf("DNSServiceResolve(), domain = %s\n", STRING_64_BYTES); if (DNSServiceResolve(&sdRef, 0, 0, "instanceName", "_test._tcp", STRING_64_BYTES, resolve_reply, NULL) == 0) { printf("DNSServiceResolve(): expected error return\n"); return 1; }; printf("Testing for error returns when various strings are > 63 bytes: PASSED\n"); return 0; } static int API_NULL_input_test() { printf("Running basic API input range tests with various pointer parameters set to NULL:\n"); // Test that API's handle NULL pointers by returning an error when appropriate. // DNSServiceRefSockFD() if (DNSServiceRefSockFD(0) != -1) { printf("DNSServiceRefSockFD(): expected dnssd_InvalidSocket return\n"); return 1; } // DNSServiceProcessResult() if (DNSServiceProcessResult(0) == 0) { printf("DNSServiceProcessResult(): expected error return\n"); return 1; } // DNSServiceRefDeallocate(): no return value, just verify it doesn't crash DNSServiceRefDeallocate(0); // DNSServiceGetProperty() { uint32_t result; uint32_t size; if ( (DNSServiceGetProperty( 0, &result, &size) == 0) || (DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, 0, &size) == 0) || (DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &result, 0) == 0) ) { printf("DNSServiceGetProperty(): expected error return\n"); return 1; } } // DNSServiceResolve() { DNSServiceRef sdRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; const char *name = "name"; const char *regtype = "_test._tcp"; const char *domain = "local"; DNSServiceResolveReply callBack = 0; void *context = 0; // can be a NULL pointer if ( (DNSServiceResolve( 0, flags, interfaceIndex, name, regtype, domain, callBack, context) == 0) || (DNSServiceResolve(&sdRef, flags, interfaceIndex, 0, regtype, domain, callBack, context) == 0) || (DNSServiceResolve(&sdRef, flags, interfaceIndex, name, 0, domain, callBack, context) == 0) || (DNSServiceResolve(&sdRef, flags, interfaceIndex, name, regtype, 0, callBack, context) == 0) || (DNSServiceResolve(&sdRef, flags, interfaceIndex, name, regtype, domain, callBack, context) == 0) ) { printf("DNSServiceResolve(): expected error return\n"); return 1; } } // DNSServiceQueryRecord() { DNSServiceRef sdRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; const char *fullname = "fullname"; uint16_t rrtype = 0; uint16_t rrclass = 0; DNSServiceQueryRecordReply callBack = 0; void *context = 0; /* may be NULL */ if ( (DNSServiceQueryRecord( 0, flags, interfaceIndex, fullname, rrtype, rrclass, callBack, context) == 0) || (DNSServiceQueryRecord(&sdRef, flags, interfaceIndex, 0, rrtype, rrclass, callBack, context) == 0) || (DNSServiceQueryRecord(&sdRef, flags, interfaceIndex, fullname, rrtype, rrclass, 0, context) == 0) ) { printf("DNSServiceQueryRecord(): expected error return\n"); return 1; } } // DNSServiceGetAddrInfo() { DNSServiceRef sdRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; DNSServiceProtocol protocol = kDNSServiceProtocol_IPv4|kDNSServiceProtocol_IPv6; const char *hostname = "host.local"; DNSServiceGetAddrInfoReply callBack = 0; void *context = 0; // may be NULL if ( (DNSServiceGetAddrInfo( 0, flags, interfaceIndex, protocol, hostname, callBack, context) == 0) || (DNSServiceGetAddrInfo(&sdRef, flags, interfaceIndex, protocol, 0, callBack, context) == 0) || (DNSServiceGetAddrInfo(&sdRef, flags, interfaceIndex, protocol, hostname, 0, context) == 0) ) { printf("DNSServiceGetAddrInfo(): expected error return\n"); return 1; } } // DNSServiceBrowse() { DNSServiceRef sdRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; const char *regtype = "_test._tcp"; const char *domain = 0; /* may be NULL */ DNSServiceBrowseReply callBack = 0; void *context = 0; /* may be NULL */ if ( (DNSServiceBrowse( 0, flags, interfaceIndex, regtype, domain, callBack, context) == 0) || (DNSServiceBrowse(&sdRef, flags, interfaceIndex, 0, domain, callBack, context) == 0) || (DNSServiceBrowse(&sdRef, flags, interfaceIndex, regtype, domain, 0, context) == 0) ) { printf("DNSServiceBrowse(): expected error return\n"); return 1; } } #if APPLE_OSX_mDNSResponder // DNSServiceSetDefaultDomainForUser() if (DNSServiceSetDefaultDomainForUser(0, 0) == 0) { printf("DNSServiceSetDefaultDomainForUser(): expected error return\n"); return 1; } #endif // DNSServiceRegister() { DNSServiceRef sdRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; const char *name = 0; /* may be NULL */ const char *regtype = "_test._tcp"; const char *domain = 0; /* may be NULL */ const char *host = 0; /* may be NULL */ uint16_t port = 0x2211; /* In network byte order */ uint16_t txtLen = 1; const void *txtRecord = "\0"; /* may be NULL */ DNSServiceRegisterReply callBack = 0; /* may be NULL */ void *context = 0; /* may be NULL */ if ( (DNSServiceRegister( 0, flags, interfaceIndex, name, regtype, domain, host, port, txtLen, txtRecord, callBack, context) == 0) || (DNSServiceRegister(&sdRef, flags, interfaceIndex, name, 0, domain, host, port, txtLen, txtRecord, callBack, context) == 0) ) { printf("DNSServiceRegister(): expected error return\n"); return 1; } } // DNSServiceEnumerateDomains() { DNSServiceRef sdRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; DNSServiceDomainEnumReply callBack = 0; void *context = 0; /* may be NULL */ if ( (DNSServiceEnumerateDomains( 0, flags, interfaceIndex, callBack, context) == 0) || (DNSServiceEnumerateDomains(&sdRef, flags, interfaceIndex, 0, context) == 0) ) { printf("DNSServiceEnumerateDomains(): expected error return\n"); return 1; } } // DNSServiceCreateConnection() if (DNSServiceCreateConnection(0) == 0) { printf("DNSServiceCreateConnection(): expected error return\n"); return 1; } #if APPLE_OSX_mDNSResponder // DNSServiceCreateDelegateConnection() if (DNSServiceCreateDelegateConnection(0, 0, 0) == 0) { printf("DNSServiceCreateDelegateConnection(): expected error return\n"); return 1; } #endif // DNSServiceRegisterRecord() { DNSServiceRef sdRef; DNSRecordRef RecordRef; DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; const char *fullname = "test1._test._tcp.local"; uint16_t rrtype = kDNSServiceType_TXT; uint16_t rrclass = kDNSServiceClass_IN; uint16_t rdlen = 1; const void *rdata = "\0"; uint32_t ttl = 0; DNSServiceRegisterRecordReply callBack = 0; void *context = 0; /* may be NULL */ // Need an initialize sdRef if (DNSServiceCreateConnection(&sdRef)) { printf("DNSServiceCreateConnection(): failed\n"); return 1; } if ( (DNSServiceRegisterRecord( 0, &RecordRef, flags, interfaceIndex, fullname, rrtype, rrclass, rdlen, rdata, ttl, callBack, context) == 0) || (DNSServiceRegisterRecord(sdRef, &RecordRef, flags, interfaceIndex, 0, rrtype, rrclass, rdlen, rdata, ttl, callBack, context) == 0) || (DNSServiceRegisterRecord(sdRef, &RecordRef, flags, interfaceIndex, fullname, rrtype, rrclass, rdlen, 0, ttl, callBack, context) == 0) || (DNSServiceRegisterRecord(sdRef, &RecordRef, flags, interfaceIndex, fullname, rrtype, rrclass, rdlen, rdata, ttl, 0, context) == 0) ) { printf("DNSServiceRegisterRecord(): expected error return\n"); return 1; } } // DNSServiceAddRecord(), DNSServiceUpdateRecord(), and DNSServiceRemoveRecord() verify that they // get a valid DNSServiceRef returned from DNSServiceRegister() { DNSServiceErrorType err; Opaque16 registerPort = { { 0x12, 0x34 } }; static const char TXT[] = "\xC" "First String"; DNSServiceRef sdRef; DNSRecordRef RecordRef; DNSServiceFlags flags = 0; uint16_t rrtype = kDNSServiceType_TXT; uint16_t rdlen = 1; const void *rdata = "\0"; uint32_t ttl = 100; err = DNSServiceRegister(&sdRef, 0, 0, "Test", "_test._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT)-1, TXT, reg_reply, NULL); if (err) { printf("DNSServiceRegister() failed with: %d\n", err); return 1; } // DNSServiceAddRecord() if ( (DNSServiceAddRecord( 0, &RecordRef, flags, rrtype, rdlen, rdata, ttl) == 0) || (DNSServiceAddRecord(sdRef, 0, flags, rrtype, rdlen, rdata, ttl) == 0) || (DNSServiceAddRecord(sdRef, &RecordRef, flags, rrtype, rdlen, 0, ttl) == 0) ) { printf("DNSServiceAddRecord(): expected error return\n"); return 1; } // (rdlen == 0 && rdata == 0) should indicate a TXT with rdata containing only a 0 length byte. if (DNSServiceAddRecord(sdRef, &RecordRef, flags, rrtype, 0, 0, ttl) == kDNSServiceErr_BadParam) { printf("DNSServiceAddRecord(): with (rdlen == 0 && rdata == 0) returned kDNSServiceErr_BadParam\n"); return 1; } // DNSServiceUpdateRecord() // Note, RecordRef can be NULL per explanation with declaration in dns_sd.h if ( (DNSServiceUpdateRecord( 0, RecordRef, flags, rdlen, rdata, ttl) == 0) || (DNSServiceUpdateRecord(sdRef, RecordRef, flags, rdlen, 0, ttl) == 0) ) { printf("DNSServiceUpdateRecord(): expected error return\n"); return 1; } // (rdlen == 0 && rdata == 0) should indicate a TXT with rdata containing only a 0 length byte. if (DNSServiceUpdateRecord(sdRef, RecordRef, flags, 0, 0, ttl) == kDNSServiceErr_BadParam) { printf("DNSServiceUpdateRecord(): with (rdlen == 0 && rdata == 0) returned kDNSServiceErr_BadParam\n"); return 1; } // DNSServiceRemoveRecord() if ( (DNSServiceRemoveRecord( 0, RecordRef, flags) == 0) || (DNSServiceRemoveRecord(sdRef, 0, flags) == 0) ) { printf("DNSServiceRemoveRecord(): expected error return\n"); return 1; } DNSServiceRefDeallocate(sdRef); } // DNSServiceReconfirmRecord() { DNSServiceFlags flags = 0; uint32_t interfaceIndex = 0; const char *fullname = "aaa._test._tcp.local"; uint16_t rrtype = kDNSServiceType_TXT; uint16_t rrclass = kDNSServiceClass_IN; uint16_t rdlen = 1; const void *rdata = "\0"; if ( (DNSServiceReconfirmRecord(flags, interfaceIndex, 0, rrtype, rrclass, rdlen, rdata) == 0) || (DNSServiceReconfirmRecord(flags, interfaceIndex, fullname, rrtype, rrclass, rdlen, 0) == 0) ) { printf("DNSServiceReconfirmRecord(): expected error return\n"); return 1; } // (rdlen == 0 && rdata == 0) should indicate a TXT with rdata containing only a 0 length byte. if (DNSServiceReconfirmRecord(flags, interfaceIndex, fullname, rrtype, rrclass, 0, 0) == kDNSServiceErr_BadParam) { printf("DNSServiceReconfirmRecord(): with (rdlen == 0 && rdata == 0) returned kDNSServiceErr_BadParam\n"); return 1; } } printf("Basic API input range tests: PASSED\n"); return 0; } static int API_input_range_test() { if (API_string_limit_test()) return 1; if (API_NULL_input_test()) return 1; return 0; } #ifdef APPLE_OSX_mDNSResponder static void handle_state_dump_request(uint8_t if_compress_state_dump, uint8_t if_dump_to_stdout); #endif // APPLE_OSX_mDNSResponder int main(int argc, char **argv) { DNSServiceErrorType err; char buffer[TypeBufferSize], *typ, *dom; int opi; DNSServiceFlags flags = 0; unsigned char enable_dnssec = 0; // Extract the program name from argv[0], which by convention contains the path to this executable. // Note that this is just a voluntary convention, not enforced by the kernel -- // the process calling exec() can pass bogus data in argv[0] if it chooses to. const char *a0 = strrchr(argv[0], kFilePathSep) + 1; if (a0 == (const char *)1) a0 = argv[0]; #if defined(_WIN32) HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0); #endif #if TEST_NEW_CLIENTSTUB printf("Using embedded copy of dnssd_clientstub instead of system library\n"); if (sizeof(argv) == 8) printf("Running in 64-bit mode\n"); #endif // Test code for TXTRecord functions //TXTRecordRef txtRecord; //TXTRecordCreate(&txtRecord, 0, NULL); //TXTRecordSetValue(&txtRecord, "aaa", 1, "b"); //printf("%d\n", TXTRecordContainsKey(TXTRecordGetLength(&txtRecord), TXTRecordGetBytesPtr(&txtRecord), "Aaa")); while (argc > 1) { int entryCount; // record current argc to see if we process an argument in this pass entryCount = argc; if (argc > 1 && !strcmp(argv[1], "-test")) { argc--; argv++; return API_input_range_test(); } if (argc > 1 && !strcmp(argv[1], "-lo")) { argc--; argv++; opinterface = kDNSServiceInterfaceIndexLocalOnly; printf("Using LocalOnly\n"); } if (argc > 1 && (!strcasecmp(argv[1], "-p2p"))) { argc--; argv++; opinterface = kDNSServiceInterfaceIndexP2P; } if (argc > 1 && (!strcasecmp(argv[1], "-ble"))) { argc--; argv++; opinterface = kDNSServiceInterfaceIndexBLE; } if (argc > 1 && !strcasecmp(argv[1], "-allowexpired")) { argc--; argv++; flags |= kDNSServiceFlagsAllowExpiredAnswers; printf("Setting kDNSServiceFlagsAllowExpiredAnswers\n"); } if (argc > 1 && !strcasecmp(argv[1], "-includep2p")) { argc--; argv++; flags |= kDNSServiceFlagsIncludeP2P; printf("Setting kDNSServiceFlagsIncludeP2P\n"); } if (argc > 1 && !strcasecmp(argv[1], "-fmc")) { argc--; argv++; flags |= kDNSServiceFlagsForceMulticast; printf("Setting kDNSServiceFlagsForceMulticast flag for this request\n"); } if (argc > 1 && !strcasecmp(argv[1], "-includeAWDL")) { argc--; argv++; flags |= kDNSServiceFlagsIncludeAWDL; printf("Setting kDNSServiceFlagsIncludeAWDL\n"); } if (argc > 1 && !strcasecmp(argv[1], "-intermediates")) { argc--; argv++; flags |= kDNSServiceFlagsReturnIntermediates; printf("Setting kDNSServiceFlagsReturnIntermediates\n"); } if (argc > 1 && !strcasecmp(argv[1], "-tc")) { argc--; argv++; flags |= kDNSServiceFlagsBackgroundTrafficClass; printf("Setting kDNSServiceFlagsBackgroundTrafficClass\n"); } if (argc > 1 && !strcasecmp(argv[1], "-t1")) { argc--; argv++; flags |= kDNSServiceFlagsThresholdOne; printf("Setting kDNSServiceFlagsThresholdOne\n"); } if (argc > 1 && !strcasecmp(argv[1], "-tFinder")) { argc--; argv++; flags |= kDNSServiceFlagsThresholdFinder; printf("Setting kDNSServiceFlagsThresholdFinder\n"); } if (argc > 1 && !strcasecmp(argv[1], "-wo")) { argc--; argv++; flags |= kDNSServiceFlagsWakeOnlyService; printf("Setting kDNSServiceFlagsWakeOnlyService\n"); } if (argc > 1 && !strcasecmp(argv[1], "-ku")) { argc--; argv++; flags |= kDNSServiceFlagsKnownUnique; printf("Setting kDNSServiceFlagsKnownUnique\n"); } if (argc > 1 && !strcasecmp(argv[1], "-unicastResponse")) { argc--; argv++; flags |= kDNSServiceFlagsUnicastResponse; printf("Setting kDNSServiceFlagsUnicastResponse\n"); } if (argc > 1 && !strcasecmp(argv[1], "-timeout")) { argc--; argv++; flags |= kDNSServiceFlagsTimeout; printf("Setting kDNSServiceFlagsTimeout\n"); } if (argc > 1 && !strcasecmp(argv[1], "-autoTrigger")) { argc--; argv++; flags |= kDNSServiceFlagsAutoTrigger; printf("Setting kDNSServiceFlagsAutoTrigger\n"); } if (argc > 1 && !strcasecmp(argv[1], "-enableDNSSEC")) { argc--; argv++; enable_dnssec = 1; printf("Enable DNSSEC validation for the '-Q' query\n"); } if (argc > 2 && !strcmp(argv[1], "-i")) { opinterface = if_nametoindex(argv[2]); if (!opinterface) opinterface = atoi(argv[2]); if (!opinterface) { fprintf(stderr, "Unknown interface %s\n", argv[2]); goto Fail; } argc -= 2; argv += 2; } // Exit loop if if we didn't match one of the multi character options. if (argc == entryCount) break; } if (argc < 2) goto Fail; // Minimum command line is the command name and one argument operation = getfirstoption(argc, argv, "ABCDEFHILMNPQRSTUVZhlq" "X" "Gg" , &opi); if (operation == -1) goto Fail; if (opinterface) printf("Using interface %d\n", opinterface); switch (operation) { case 'E': printf("Looking for recommended registration domains:\n"); err = DNSServiceEnumerateDomains(&client, kDNSServiceFlagsRegistrationDomains, opinterface, enum_reply, NULL); break; case 'F': printf("Looking for recommended browsing domains:\n"); err = DNSServiceEnumerateDomains(&client, kDNSServiceFlagsBrowseDomains, opinterface, enum_reply, NULL); //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "nicta.com.au.", NULL); //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "bonjour.nicta.com.au.", NULL); //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "ibm.com.", NULL); //enum_reply(client, kDNSServiceFlagsAdd, 0, 0, "dns-sd.ibm.com.", NULL); break; case 'B': typ = (argc < opi+1) ? "" : argv[opi+0]; dom = (argc < opi+2) ? "" : argv[opi+1]; // Missing domain argument is the same as empty string i.e. use system default(s) typ = gettype(buffer, typ); if (dom[0] == '.' && dom[1] == 0) dom[0] = 0; // We allow '.' on the command line as a synonym for empty string printf("Browsing for %s%s%s\n", typ, dom[0] ? "." : "", dom); err = DNSServiceBrowse(&client, flags, opinterface, typ, dom, browse_reply, NULL); break; case 'Z': typ = (argc < opi+1) ? "" : argv[opi+0]; dom = (argc < opi+2) ? "" : argv[opi+1]; // Missing domain argument is the same as empty string i.e. use system default(s) typ = gettype(buffer, typ); if (dom[0] == '.' && dom[1] == 0) dom[0] = 0; // We allow '.' on the command line as a synonym for empty string printf("Browsing for %s%s%s\n", typ, dom[0] ? "." : "", dom); err = DNSServiceCreateConnection(&client); if (err) { fprintf(stderr, "DNSServiceCreateConnection returned %d\n", err); return(err); } sc1 = client; err = DNSServiceBrowse(&sc1, kDNSServiceFlagsShareConnection, opinterface, typ, dom, zonedata_browse, NULL); break; case 'l': case 'L': { if (argc < opi+2) goto Fail; typ = (argc < opi+2) ? "" : argv[opi+1]; dom = (argc < opi+3) ? "local" : argv[opi+2]; typ = gettype(buffer, typ); if (dom[0] == '.' && dom[1] == 0) dom = "local"; // We allow '.' on the command line as a synonym for "local" printf("Lookup %s.%s.%s\n", argv[opi+0], typ, dom); if (operation == 'l') flags |= kDNSServiceFlagsWakeOnResolve; err = DNSServiceResolve(&client, flags, opinterface, argv[opi+0], typ, dom, resolve_reply, NULL); break; } case 'R': if (argc < opi+4) goto Fail; typ = (argc < opi+2) ? "" : argv[opi+1]; dom = (argc < opi+3) ? "" : argv[opi+2]; typ = gettype(buffer, typ); if (dom[0] == '.' && dom[1] == 0) dom[0] = 0; // We allow '.' on the command line as a synonym for empty string err = RegisterService(&client, argv[opi+0], typ, dom, NULL, argv[opi+3], argc-(opi+4), argv+(opi+4), flags); break; case 'P': if (argc < opi+6) goto Fail; err = DNSServiceCreateConnection(&client_pa); if (err) { fprintf(stderr, "DNSServiceCreateConnection returned %d\n", err); return(err); } err = RegisterProxyAddressRecord(client_pa, argv[opi+4], argv[opi+5], flags); if (err) break; err = RegisterService(&client, argv[opi+0], gettype(buffer, argv[opi+1]), argv[opi+2], argv[opi+4], argv[opi+3], argc-(opi+6), argv+(opi+6), flags); break; case 'q': case 'Q': case 'C': { uint16_t rrtype, rrclass; flags |= kDNSServiceFlagsReturnIntermediates; if (operation == 'q') flags |= kDNSServiceFlagsSuppressUnusable; if (enable_dnssec) flags |= kDNSServiceFlagsEnableDNSSEC; if (argc < opi+1) goto Fail; rrtype = (argc <= opi+1) ? kDNSServiceType_A : GetRRType(argv[opi+1]); rrclass = (argc <= opi+2) ? kDNSServiceClass_IN : GetRRClass(argv[opi+2]); if (rrtype == kDNSServiceType_TXT || rrtype == kDNSServiceType_PTR) flags |= kDNSServiceFlagsLongLivedQuery; err = DNSServiceQueryRecord(&client, flags, opinterface, argv[opi+0], rrtype, rrclass, qr_reply, NULL); break; } case 'A': case 'U': case 'N': { Opaque16 registerPort = { { 0x12, 0x34 } }; static const char TXT[] = "\xC" "First String" "\xD" "Second String" "\xC" "Third String"; printf("Registering Service Test._testupdate._tcp.local.\n"); err = DNSServiceRegister(&client, 0, opinterface, "Test", "_testupdate._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT)-1, TXT, reg_reply, NULL); break; } case 'T': { Opaque16 registerPort = { { 0x23, 0x45 } }; char TXT[1024]; unsigned int i; for (i=0; i> 5); printf("Registering Service Test._testlargetxt._tcp.local.\n"); err = DNSServiceRegister(&client, 0, opinterface, "Test", "_testlargetxt._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT), TXT, reg_reply, NULL); break; } case 'M': { pid_t pid = getpid(); Opaque16 registerPort = { { pid >> 8, pid & 0xFF } }; static const char TXT1[] = "\xC" "First String" "\xD" "Second String" "\xC" "Third String"; static const char TXT2[] = "\xD" "Fourth String" "\xC" "Fifth String" "\xC" "Sixth String"; printf("Registering Service Test._testdualtxt._tcp.local.\n"); err = DNSServiceRegister(&client, flags, opinterface, "Test", "_testdualtxt._tcp.", "", NULL, registerPort.NotAnInteger, sizeof(TXT1)-1, TXT1, reg_reply, NULL); if (!err) err = DNSServiceAddRecord(client, &record, flags, kDNSServiceType_TXT, sizeof(TXT2)-1, TXT2, 0); break; } case 'I': { pid_t pid = getpid(); Opaque16 registerPort = { { pid >> 8, pid & 0xFF } }; static const char TXT[] = "\x09" "Test Data"; printf("Registering Service Test._testtxt._tcp.local.\n"); err = DNSServiceRegister(&client, 0, opinterface, "Test", "_testtxt._tcp.", "", NULL, registerPort.NotAnInteger, 0, NULL, reg_reply, NULL); if (!err) err = DNSServiceUpdateRecord(client, NULL, 0, sizeof(TXT)-1, TXT, 0); break; } case 'X': { if (argc == opi) // If no arguments, just fetch IP address err = DNSServiceNATPortMappingCreate(&client, 0, 0, 0, 0, 0, 0, port_mapping_create_reply, NULL); else if (argc >= opi+2 && atoi(argv[opi+0]) == 0) { DNSServiceProtocol prot = GetProtocol(argv[opi+0]); // Must specify TCP or UDP uint16_t IntPortAsNumber = atoi(argv[opi+1]); // Must specify internal port uint16_t ExtPortAsNumber = (argc < opi+3) ? 0 : atoi(argv[opi+2]); // Optional desired external port uint32_t ttl = (argc < opi+4) ? 0 : atoi(argv[opi+3]); // Optional desired lease lifetime Opaque16 intp = { { IntPortAsNumber >> 8, IntPortAsNumber & 0xFF } }; Opaque16 extp = { { ExtPortAsNumber >> 8, ExtPortAsNumber & 0xFF } }; err = DNSServiceNATPortMappingCreate(&client, 0, 0, prot, intp.NotAnInteger, extp.NotAnInteger, ttl, port_mapping_create_reply, NULL); } else goto Fail; break; } case 'G': { flags |= kDNSServiceFlagsReturnIntermediates; if (argc != opi+2) goto Fail; else err = DNSServiceGetAddrInfo(&client, flags, opinterface, GetProtocol(argv[opi+0]), argv[opi+1], addrinfo_reply, NULL); break; } case 'S': { Opaque16 registerPort = { { 0x23, 0x45 } }; // 9029 decimal unsigned char txtrec[16] = "\xF" "/path=test.html"; DNSRecordRef rec; unsigned char nulrec[4] = "1234"; err = DNSServiceCreateConnection(&client); if (err) { fprintf(stderr, "DNSServiceCreateConnection failed %ld\n", (long int)err); return (-1); } sc1 = client; err = DNSServiceBrowse(&sc1, kDNSServiceFlagsShareConnection, opinterface, "_http._tcp", "", browse_reply, NULL); if (err) { fprintf(stderr, "DNSServiceBrowse _http._tcp failed %ld\n", (long int)err); return (-1); } sc2 = client; err = DNSServiceBrowse(&sc2, kDNSServiceFlagsShareConnection, opinterface, "_ftp._tcp", "", browse_reply, NULL); if (err) { fprintf(stderr, "DNSServiceBrowse _ftp._tcp failed %ld\n", (long int)err); return (-1); } sc3 = client; err = DNSServiceRegister(&sc3, kDNSServiceFlagsShareConnection, opinterface, "kDNSServiceFlagsShareConnection", "_http._tcp", "local", NULL, registerPort.NotAnInteger, 0, NULL, reg_reply, NULL); if (err) { fprintf(stderr, "SharedConnection DNSServiceRegister failed %ld\n", (long int)err); return (-1); } err = DNSServiceUpdateRecord(sc3, NULL, 0, sizeof(txtrec), txtrec, 0); if (err) { fprintf(stderr, "SharedConnection DNSServiceUpdateRecord failed %ld\n", (long int)err); return (-1); } err = DNSServiceAddRecord(sc3, &rec, 0, kDNSServiceType_NULL, sizeof(nulrec), nulrec, 0); if (err) { fprintf(stderr, "SharedConnection DNSServiceAddRecord failed %ld\n", (long int)err); return (-1); } err = DNSServiceRemoveRecord(sc3, rec, 0); if (err) { fprintf(stderr, "SharedConnection DNSServiceRemoveRecord failed %ld\n", (long int)err); return (-1); } break; } case 'V': { uint32_t v; uint32_t size = sizeof(v); err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &v, &size); if (err) fprintf(stderr, "DNSServiceGetProperty failed %ld\n", (long int)err); else printf("Currently running daemon (system service) is version %d.%d.%d\n", v / 10000, v / 100 % 100, v % 100); exit(0); } #ifdef APPLE_OSX_mDNSResponder case 'O': { // check if the user specifies the flag "-compress" uint8_t if_compress_state_dump = 0; uint8_t if_dump_to_stdout = 0; if (argc > opi+1) { printf("dns-sd: illegal option count\n"); goto Fail; } if (argc == opi+1) { const char *param = argv[opi]; if (strcasecmp("-compress", param) == 0) { if_compress_state_dump = 1; } else if (strcasecmp("-stdout", param) == 0) { if_dump_to_stdout = 1; } else { printf("dns-sd: illegal option %s \n", param); goto Fail; } } handle_state_dump_request(if_compress_state_dump, if_dump_to_stdout); err = kDNSServiceErr_NoError; break; } #endif // APPLE_OSX_mDNSResponder case 'H': goto Fail; default: goto Fail; } #ifdef APPLE_OSX_mDNSResponder // state dump does not need to create DNSServiceRef, so we can return directly here without cleaning up. if (operation == 'O') return 0; #endif // APPLE_OSX_mDNSResponder if (!client || err != kDNSServiceErr_NoError) { fprintf(stderr, "DNSService call failed %ld%s\n", (long int)err, (err == kDNSServiceErr_ServiceNotRunning) ? " (Service Not Running)" : ""); return (-1); } printtimestamp(); printf("...STARTING...\n"); HandleEvents(); // Be sure to deallocate the DNSServiceRef when you're finished if (client ) DNSServiceRefDeallocate(client ); if (client_pa) DNSServiceRefDeallocate(client_pa); return 0; Fail: if (operation == 'H') print_usage(a0,1); else print_usage(a0,0); return 0; } #ifdef APPLE_OSX_mDNSResponder /* * if_compress_state_dump and if_dump_to_stdout cannot be set at the same time. */ static void handle_state_dump_request(uint8_t if_compress_state_dump, uint8_t if_dump_to_stdout) { // create xpc connection to the xpc server for log utility xpc_connection_t log_utility_connection = xpc_connection_create_mach_service(kDNSLogUtilityService, dispatch_get_main_queue(), XPC_CONNECTION_MACH_SERVICE_PRIVILEGED); xpc_connection_set_event_handler(log_utility_connection, ^(xpc_object_t event){ printf("Connecting to %s, status: %s\n", kDNSLogUtilityService, xpc_dictionary_get_string(event, XPC_ERROR_KEY_DESCRIPTION)); }); xpc_connection_resume(log_utility_connection); // set option for the state dump xpc_object_t xpc_dict = xpc_dictionary_create(NULL, NULL, 0); uint64_t dump_option; if (if_compress_state_dump) { dump_option = full_state_with_compression; } else if (if_dump_to_stdout) { // we pass the stdout directly to xpc server dump_option = full_state_to_stdout; xpc_dictionary_set_fd(xpc_dict, kDNSStateDumpFD, STDOUT_FILENO); } else { dump_option = full_state; } xpc_dictionary_set_uint64(xpc_dict, kDNSStateDump, dump_option); // send the request and handle the response from xpc server xpc_connection_send_message_with_reply(log_utility_connection, xpc_dict, dispatch_get_main_queue(), ^(xpc_object_t recv_msg){ xpc_type_t msg_type = xpc_get_type(recv_msg); if (msg_type != XPC_TYPE_DICTIONARY) { printf("Received unexpected reply from daemon, error: \"%s\"\nUnexpected reply Contents:\n%s\n", xpc_dictionary_get_string(recv_msg, XPC_ERROR_KEY_DESCRIPTION), xpc_copy_description(recv_msg)); exit(1); } // get the response dictionary uint32_t return_code = (uint32_t)xpc_dictionary_get_uint64(recv_msg, kDNSDaemonReply); if (return_code != kDNSMsg_NoError) { const char *error_description = xpc_dictionary_get_string(recv_msg, kDNSErrorDescription); printf("XPC service returns error, description: %s\n", error_description); exit(1); } // print the state information returned from the XPC server if (dump_option != full_state_to_stdout) { const char *path = xpc_dictionary_get_string(recv_msg, kDNSDumpFilePath); printf("State Dump Is Saved to: %s\n", path); } int64_t time_used = xpc_dictionary_get_int64(recv_msg, kDNSStateDumpTimeUsed); printf(" Time Used: %" PRId64 " ms\n", time_used); xpc_release(xpc_dict); exit(0); }); dispatch_main(); } #endif // APPLE_OSX_mDNSResponder // Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion // e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4" // To expand "version" to its value before making the string, use STRINGIFY(version) instead #define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s #define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) // NOT static -- otherwise the compiler may optimize it out // The "@(#) " pattern is a special prefix the "what" command looks for #ifndef MDNS_VERSIONSTR_NODTS const char VersionString_SCCS[] = "@(#) dns-sd " STRINGIFY(mDNSResponderVersion) " (" __DATE__ " " __TIME__ ")"; #else const char VersionString_SCCS[] = "@(#) dns-sd " STRINGIFY(mDNSResponderVersion); #endif #if _BUILDING_XCODE_PROJECT_ // If the process crashes, then this string will be magically included in the automatically-generated crash log const char *__crashreporter_info__ = VersionString_SCCS + 5; asm (".desc ___crashreporter_info__, 0x10"); #endif The majority of the source code in the mDNSResponder project is licensed under the terms of the Apache License, Version 2.0, available from: To accommodate license compatibility with the widest possible range of client code licenses, the shared library code, which is linked at runtime into the same address space as the client using it, is licensed under the terms of the "Three-Clause BSD License". The Linux Name Service Switch code, contributed by National ICT Australia Ltd (NICTA) is licensed under the terms of the NICTA Public Software Licence (which is substantially similar to the "Three-Clause BSD License", with some additional language pertaining to Australian law). mDNSResponder # # Copyright 2007 Sun Microsystems, Inc. All rights reserved. # Use is subject to license terms. # # CDDL HEADER START # # The contents of this file are subject to the terms of the # Common Development and Distribution License (the "License"). # You may not use this file except in compliance with the License. # # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE # or http://www.opensolaris.org/os/licensing. # See the License for the specific language governing permissions # and limitations under the License. # # When distributing Covered Code, include this CDDL HEADER in each # file and include the License file at usr/src/OPENSOLARIS.LICENSE. # If applicable, add the following below this CDDL HEADER, with the # fields enclosed by brackets "[]" replaced with your own identifying # information: Portions Copyright [yyyy] [name of copyright owner] # # CDDL HEADER END # The mdns vendor source repository is at https://github.com/illumos/mdns/. Updated from upstream version mDNSResponder-1310.80.1 Updated from upstream version mDNSResponder-878.260.1 Updated from upstream version mDNSResponder-878.1.1 Updated from upstream version mDNSResponder-625.41.2 Updated from upstream version mDNSResponder-576.30.4 Multicast DNS and Service Discovery support in illumos using the Apple Bonjour source code (v107.6). Apple Bonjour source can be downloaded from: https://opensource.apple.com/tarballs/mDNSResponder/ The following components are integrated from the Apple Bonjour source in illumos: libdns_sd: usr/src/lib/libdns_sd mdnsd: usr/src/cmd/cmd-inet/usr.lib/mdnsd dns-sd: usr/src/cmd/cmd-inet/usr.bin/dns-sd Following fixes have been made to the Apple Bonjour source integrated in illumos: * 64-bit support by adding pad bytes in ipc_msg_hdr_struct * 64-bit support in libjdns_sd, dnssd.jar (JNISupport.c, DNSSD.java) * mdnsd switches to user 'noaccess' and not 'nobody' after init * Fixes to support IPv6 (mDNSPosix.c, mDNSUNP.c) * Fix error raised when uDNS.c is compiled with Sun Studio compiler * Fix in dnssd_clientstub.c to not check errno when recvmsg returns 0 * mDNSDebug.c modified to not send msgs directly to console when syslog call returns an error. Logs the messages at LOG_INFO level and not LOG_ERR In addition the project introduces the following changes: * A new nss_mdns module is introduced to use Multicast DNS (mdns) for resolving link-local hostnames and is located at: usr/src/lib/nsswitch/mdns * snoop updated to decode mDNS packets * updated /etc/services to include mdns * updated to include mdns * svc:/network/dns/multicast:default introduced to manage mDNS daemon * solaris.smf.manage.mdns & solaris.smf.value.mdns authorizations to modify nss_mdns configuration in svc:/network/dns/multicast:default Both authorizations added in network management execution profile. * Default nsswitch.dns includes mdns as source for hosts & ipnodes * nscd daemon updated to support mdns * SUNWdsdu and SUNWdsdr packages deliver all the new mDNS service discovery components. #!/bin/ksh if [ ! -d "$1" ]; then echo "\"$1\" should be source repository root directory" exit 1 fi for f in LICENSE */* do cp $1/$f $f done /* -*- Mode: C; tab-width: 4; c-file-style: "bsd"; c-basic-offset: 4; fill-column: 108; indent-tabs-mode: nil; -*- * * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef STANDALONE // Set mDNS_InstantiateInlines to tell mDNSEmbeddedAPI.h to instantiate inline functions, if necessary #define mDNS_InstantiateInlines 1 #include "DNSCommon.h" #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #include "dnssec_v2.h" #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // Disable certain benign warnings with Microsoft compilers #if (defined(_MSC_VER)) // Disable "conditional expression is constant" warning for debug macros. // Otherwise, this generates warnings for the perfectly natural construct "while(1)" // If someone knows a variant way of writing "while(1)" that doesn't generate warning messages, please let us know #pragma warning(disable:4127) // Disable "array is too small to include a terminating null character" warning // -- domain labels have an initial length byte, not a terminating null character #pragma warning(disable:4295) #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Program Constants #endif mDNSexport const mDNSInterfaceID mDNSInterface_Any = 0; mDNSexport const mDNSInterfaceID mDNSInterfaceMark = (mDNSInterfaceID)-1; mDNSexport const mDNSInterfaceID mDNSInterface_LocalOnly = (mDNSInterfaceID)-2; mDNSexport const mDNSInterfaceID mDNSInterface_P2P = (mDNSInterfaceID)-3; mDNSexport const mDNSInterfaceID uDNSInterfaceMark = (mDNSInterfaceID)-4; mDNSexport const mDNSInterfaceID mDNSInterface_BLE = (mDNSInterfaceID)-5; // Note: Microsoft's proposed "Link Local Multicast Name Resolution Protocol" (LLMNR) is essentially a limited version of // Multicast DNS, using the same packet formats, naming syntax, and record types as Multicast DNS, but on a different UDP // port and multicast address, which means it won't interoperate with the existing installed base of Multicast DNS responders. // LLMNR uses IPv4 multicast address 224.0.0.252, IPv6 multicast address FF02::0001:0003, and UDP port 5355. // Uncomment the appropriate lines below to build a special Multicast DNS responder for testing interoperability // with Microsoft's LLMNR client code. #define DiscardPortAsNumber 9 #define SSHPortAsNumber 22 #define UnicastDNSPortAsNumber 53 #define SSDPPortAsNumber 1900 #define IPSECPortAsNumber 4500 #define NSIPCPortAsNumber 5030 // Port used for dnsextd to talk to local nameserver bound to loopback #define NATPMPAnnouncementPortAsNumber 5350 #define NATPMPPortAsNumber 5351 #define DNSEXTPortAsNumber 5352 // Port used for end-to-end DNS operations like LLQ, Updates with Leases, etc. #define MulticastDNSPortAsNumber 5353 #define LoopbackIPCPortAsNumber 5354 //#define MulticastDNSPortAsNumber 5355 // LLMNR #define PrivateDNSPortAsNumber 5533 mDNSexport const mDNSIPPort DiscardPort = { { DiscardPortAsNumber >> 8, DiscardPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort SSHPort = { { SSHPortAsNumber >> 8, SSHPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort UnicastDNSPort = { { UnicastDNSPortAsNumber >> 8, UnicastDNSPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort SSDPPort = { { SSDPPortAsNumber >> 8, SSDPPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort IPSECPort = { { IPSECPortAsNumber >> 8, IPSECPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort NSIPCPort = { { NSIPCPortAsNumber >> 8, NSIPCPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort NATPMPAnnouncementPort = { { NATPMPAnnouncementPortAsNumber >> 8, NATPMPAnnouncementPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort NATPMPPort = { { NATPMPPortAsNumber >> 8, NATPMPPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort DNSEXTPort = { { DNSEXTPortAsNumber >> 8, DNSEXTPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort MulticastDNSPort = { { MulticastDNSPortAsNumber >> 8, MulticastDNSPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort LoopbackIPCPort = { { LoopbackIPCPortAsNumber >> 8, LoopbackIPCPortAsNumber & 0xFF } }; mDNSexport const mDNSIPPort PrivateDNSPort = { { PrivateDNSPortAsNumber >> 8, PrivateDNSPortAsNumber & 0xFF } }; mDNSexport const OwnerOptData zeroOwner = { 0, 0, { { 0 } }, { { 0 } }, { { 0 } } }; mDNSexport const mDNSIPPort zeroIPPort = { { 0 } }; mDNSexport const mDNSv4Addr zerov4Addr = { { 0 } }; mDNSexport const mDNSv6Addr zerov6Addr = { { 0 } }; mDNSexport const mDNSEthAddr zeroEthAddr = { { 0 } }; mDNSexport const mDNSv4Addr onesIPv4Addr = { { 255, 255, 255, 255 } }; mDNSexport const mDNSv6Addr onesIPv6Addr = { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 } }; mDNSexport const mDNSEthAddr onesEthAddr = { { 255, 255, 255, 255, 255, 255 } }; mDNSexport const mDNSAddr zeroAddr = { mDNSAddrType_None, {{{ 0 }}} }; mDNSexport const mDNSv4Addr AllDNSAdminGroup = { { 239, 255, 255, 251 } }; mDNSexport const mDNSv4Addr AllHosts_v4 = { { 224, 0, 0, 1 } }; // For NAT-PMP & PCP Annoucements mDNSexport const mDNSv6Addr AllHosts_v6 = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01 } }; mDNSexport const mDNSv6Addr NDP_prefix = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01, 0xFF,0x00,0x00,0xFB } }; // FF02:0:0:0:0:1:FF00::/104 mDNSexport const mDNSEthAddr AllHosts_v6_Eth = { { 0x33, 0x33, 0x00, 0x00, 0x00, 0x01 } }; mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 251 } } } }; //mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 252 } } } }; // LLMNR mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0xFB } } } }; //mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x01,0x00,0x03 } } } }; // LLMNR mDNSexport const mDNSOpaque16 zeroID = { { 0, 0 } }; mDNSexport const mDNSOpaque16 onesID = { { 255, 255 } }; mDNSexport const mDNSOpaque16 QueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery, 0 } }; mDNSexport const mDNSOpaque16 uQueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery | kDNSFlag0_RD, 0 } }; mDNSexport const mDNSOpaque16 ResponseFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery | kDNSFlag0_AA, 0 } }; mDNSexport const mDNSOpaque16 UpdateReqFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_Update, 0 } }; mDNSexport const mDNSOpaque16 UpdateRespFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_Update, 0 } }; mDNSexport const mDNSOpaque64 zeroOpaque64 = { { 0 } }; mDNSexport const mDNSOpaque128 zeroOpaque128 = { { 0 } }; extern mDNS mDNSStorage; // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - General Utility Functions #endif // return true for RFC1918 private addresses mDNSexport mDNSBool mDNSv4AddrIsRFC1918(const mDNSv4Addr * const addr) { return ((addr->b[0] == 10) || // 10/8 prefix (addr->b[0] == 172 && (addr->b[1] & 0xF0) == 16) || // 172.16/12 (addr->b[0] == 192 && addr->b[1] == 168)); // 192.168/16 } mDNSexport const char *DNSScopeToString(mDNSu32 scope) { switch (scope) { case kScopeNone: return "Unscoped"; case kScopeInterfaceID: return "InterfaceScoped"; case kScopeServiceID: return "ServiceScoped"; default: return "Unknown"; } } mDNSexport void mDNSAddrMapIPv4toIPv6(mDNSv4Addr* in, mDNSv6Addr* out) { out->l[0] = 0; out->l[1] = 0; out->w[4] = 0; out->w[5] = 0xffff; out->b[12] = in->b[0]; out->b[13] = in->b[1]; out->b[14] = in->b[2]; out->b[15] = in->b[3]; } mDNSexport mDNSBool mDNSAddrIPv4FromMappedIPv6(mDNSv6Addr *in, mDNSv4Addr* out) { if (in->l[0] != 0 || in->l[1] != 0 || in->w[4] != 0 || in->w[5] != 0xffff) return mDNSfalse; out->NotAnInteger = in->l[3]; return mDNStrue; } mDNSexport NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf) { while (intf && !intf->InterfaceActive) intf = intf->next; return(intf); } mDNSexport mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf) { const NetworkInterfaceInfo *next = GetFirstActiveInterface(intf->next); if (next) return(next->InterfaceID);else return(mDNSNULL); } mDNSexport mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id) { mDNSu32 slot, used = 0; CacheGroup *cg; const CacheRecord *rr; FORALL_CACHERECORDS(slot, cg, rr) { if (rr->resrec.InterfaceID == id) used++; } return(used); } mDNSexport char *DNSTypeName(mDNSu16 rrtype) { switch (rrtype) { case kDNSType_A: return("Addr"); case kDNSType_NS: return("NS"); case kDNSType_CNAME: return("CNAME"); case kDNSType_SOA: return("SOA"); case kDNSType_NULL: return("NULL"); case kDNSType_PTR: return("PTR"); case kDNSType_HINFO: return("HINFO"); case kDNSType_TXT: return("TXT"); case kDNSType_AAAA: return("AAAA"); case kDNSType_SRV: return("SRV"); case kDNSType_OPT: return("OPT"); case kDNSType_NSEC: return("NSEC"); case kDNSType_NSEC3: return("NSEC3"); case kDNSType_NSEC3PARAM: return("NSEC3PARAM"); case kDNSType_TSIG: return("TSIG"); case kDNSType_RRSIG: return("RRSIG"); case kDNSType_DNSKEY: return("DNSKEY"); case kDNSType_DS: return("DS"); case kDNSType_SVCB: return("SVCB"); case kDNSType_HTTPS: return("HTTPS"); case kDNSQType_ANY: return("ANY"); default: { static char buffer[16]; mDNS_snprintf(buffer, sizeof(buffer), "TYPE%d", rrtype); return(buffer); } } } mDNSexport const char *mStatusDescription(mStatus error) { const char *error_description; switch (error) { case mStatus_NoError: error_description = "mStatus_NoError"; break; case mStatus_BadParamErr: error_description = "mStatus_BadParamErr"; break; default: error_description = "mStatus_UnknownDescription"; break; } return error_description; } mDNSexport mDNSu32 swap32(mDNSu32 x) { mDNSu8 *ptr = (mDNSu8 *)&x; return (mDNSu32)((mDNSu32)ptr[0] << 24 | (mDNSu32)ptr[1] << 16 | (mDNSu32)ptr[2] << 8 | ptr[3]); } mDNSexport mDNSu16 swap16(mDNSu16 x) { mDNSu8 *ptr = (mDNSu8 *)&x; return (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); } mDNSlocal void PrintTypeBitmap(const mDNSu8 *bmap, int bitmaplen, char *const buffer, mDNSu32 length) { int win, wlen, type; while (bitmaplen > 0) { int i; if (bitmaplen < 3) { LogMsg("PrintTypeBitmap: malformed bitmap, bitmaplen %d short", bitmaplen); break; } win = *bmap++; wlen = *bmap++; bitmaplen -= 2; if (bitmaplen < wlen || wlen < 1 || wlen > 32) { LogInfo("PrintTypeBitmap: malformed nsec, bitmaplen %d wlen %d", bitmaplen, wlen); break; } if (win < 0 || win >= 256) { LogInfo("PrintTypeBitmap: malformed nsec, bad window win %d", win); break; } type = win * 256; for (i = 0; i < wlen * 8; i++) { if (bmap[i>>3] & (128 >> (i&7))) length += mDNS_snprintf(buffer+length, (MaxMsg - 1) - length, "%s ", DNSTypeName(type + i)); } bmap += wlen; bitmaplen -= wlen; } } // Note slight bug: this code uses the rdlength from the ResourceRecord object, to display // the rdata from the RDataBody object. Sometimes this could be the wrong length -- but as // long as this routine is only used for debugging messages, it probably isn't a big problem. mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RDataBody *const rd1, char *const buffer) { const RDataBody2 *const rd = (RDataBody2 *)rd1; #define RemSpc (MaxMsg-1-length) char *ptr = buffer; mDNSu32 length = mDNS_snprintf(buffer, MaxMsg-1, "%4d %##s %s ", rr->rdlength, rr->name->c, DNSTypeName(rr->rrtype)); if (rr->RecordType == kDNSRecordTypePacketNegative) return(buffer); if (!rr->rdlength && rr->rrtype != kDNSType_OPT) { mDNS_snprintf(buffer+length, RemSpc, "<< ZERO RDATA LENGTH >>"); return(buffer); } switch (rr->rrtype) { case kDNSType_A: mDNS_snprintf(buffer+length, RemSpc, "%.4a", &rd->ipv4); break; case kDNSType_NS: // Same as PTR case kDNSType_CNAME: // Same as PTR case kDNSType_PTR: mDNS_snprintf(buffer+length, RemSpc, "%##s", rd->name.c); break; case kDNSType_SOA: mDNS_snprintf(buffer+length, RemSpc, "%##s %##s %d %d %d %d %d", rd->soa.mname.c, rd->soa.rname.c, rd->soa.serial, rd->soa.refresh, rd->soa.retry, rd->soa.expire, rd->soa.min); break; case kDNSType_HINFO: // Display this the same as TXT (show all constituent strings) case kDNSType_TXT: { const mDNSu8 *t = rd->txt.c; const mDNSu8 *const rdLimit = rd->data + rr->rdlength; const char *separator = ""; while (t < rdLimit) { mDNSu32 characterStrLength = *t; if (characterStrLength + 1 > (mDNSu32)(rdLimit - t)) // Character string goes out of boundary. { const mDNSu8 *const remainderStart = t + 1; const mDNSu32 remainderLength = (mDNSu32)(rdLimit - remainderStart); length += mDNS_snprintf(buffer + length, RemSpc, "%s%.*s<>", separator, remainderLength, remainderStart); (void)length; // Acknowledge "dead store" analyzer warning. break; } length += mDNS_snprintf(buffer+length, RemSpc, "%s%.*s", separator, characterStrLength, t + 1); separator = "¦"; t += 1 + characterStrLength; } } break; case kDNSType_AAAA: mDNS_snprintf(buffer+length, RemSpc, "%.16a", &rd->ipv6); break; case kDNSType_SRV: mDNS_snprintf(buffer+length, RemSpc, "%u %u %u %##s", rd->srv.priority, rd->srv.weight, mDNSVal16(rd->srv.port), rd->srv.target.c); break; case kDNSType_OPT: { const rdataOPT *opt; const rdataOPT *const end = (const rdataOPT *)&rd->data[rr->rdlength]; length += mDNS_snprintf(buffer+length, RemSpc, "Max %d", rr->rrclass); for (opt = &rd->opt[0]; opt < end; opt++) { switch(opt->opt) { case kDNSOpt_LLQ: length += mDNS_snprintf(buffer+length, RemSpc, " LLQ"); length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d", opt->u.llq.vers); length += mDNS_snprintf(buffer+length, RemSpc, " Op %d", opt->u.llq.llqOp); length += mDNS_snprintf(buffer+length, RemSpc, " Err/Port %d", opt->u.llq.err); length += mDNS_snprintf(buffer+length, RemSpc, " ID %08X%08X", opt->u.llq.id.l[0], opt->u.llq.id.l[1]); length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d", opt->u.llq.llqlease); break; case kDNSOpt_Lease: length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d", opt->u.updatelease); break; case kDNSOpt_Owner: length += mDNS_snprintf(buffer+length, RemSpc, " Owner"); length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d", opt->u.owner.vers); length += mDNS_snprintf(buffer+length, RemSpc, " Seq %3d", (mDNSu8)opt->u.owner.seq); // Display as unsigned length += mDNS_snprintf(buffer+length, RemSpc, " MAC %.6a", opt->u.owner.HMAC.b); if (opt->optlen >= DNSOpt_OwnerData_ID_Wake_Space-4) { length += mDNS_snprintf(buffer+length, RemSpc, " I-MAC %.6a", opt->u.owner.IMAC.b); if (opt->optlen > DNSOpt_OwnerData_ID_Wake_Space-4) length += mDNS_snprintf(buffer+length, RemSpc, " Password %.6a", opt->u.owner.password.b); } break; case kDNSOpt_Trace: length += mDNS_snprintf(buffer+length, RemSpc, " Trace"); length += mDNS_snprintf(buffer+length, RemSpc, " Platform %d", opt->u.tracer.platf); length += mDNS_snprintf(buffer+length, RemSpc, " mDNSVers %d", opt->u.tracer.mDNSv); break; default: length += mDNS_snprintf(buffer+length, RemSpc, " Unknown %d", opt->opt); break; } } } break; case kDNSType_NSEC: { domainname *next = (domainname *)rd->data; int len, bitmaplen; mDNSu8 *bmap; len = DomainNameLength(next); bitmaplen = rr->rdlength - len; bmap = (mDNSu8 *)((mDNSu8 *)next + len); if (UNICAST_NSEC(rr)) length += mDNS_snprintf(buffer+length, RemSpc, "%##s ", next->c); PrintTypeBitmap(bmap, bitmaplen, buffer, length); } break; default: mDNS_snprintf(buffer+length, RemSpc, "RDLen %d: %.*s", rr->rdlength, rr->rdlength, rd->data); // Really should scan buffer to check if text is valid UTF-8 and only replace with dots if not for (ptr = buffer; *ptr; ptr++) if (*ptr < ' ') *ptr = '.'; break; } return(buffer); } // See comments in mDNSEmbeddedAPI.h #if _PLATFORM_HAS_STRONG_PRNG_ #define mDNSRandomNumber mDNSPlatformRandomNumber #else mDNSlocal mDNSu32 mDNSRandomFromSeed(mDNSu32 seed) { return seed * 21 + 1; } mDNSlocal mDNSu32 mDNSMixRandomSeed(mDNSu32 seed, mDNSu8 iteration) { return iteration ? mDNSMixRandomSeed(mDNSRandomFromSeed(seed), --iteration) : seed; } mDNSlocal mDNSu32 mDNSRandomNumber() { static mDNSBool seeded = mDNSfalse; static mDNSu32 seed = 0; if (!seeded) { seed = mDNSMixRandomSeed(mDNSPlatformRandomSeed(), 100); seeded = mDNStrue; } return (seed = mDNSRandomFromSeed(seed)); } #endif // ! _PLATFORM_HAS_STRONG_PRNG_ mDNSexport mDNSu32 mDNSRandom(mDNSu32 max) // Returns pseudo-random result from zero to max inclusive { mDNSu32 ret = 0; mDNSu32 mask = 1; while (mask < max) mask = (mask << 1) | 1; do ret = mDNSRandomNumber() & mask; while (ret > max); return ret; } mDNSexport mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2) { if (ip1->type == ip2->type) { switch (ip1->type) { case mDNSAddrType_None: return(mDNStrue); // Empty addresses have no data and are therefore always equal case mDNSAddrType_IPv4: return (mDNSBool)(mDNSSameIPv4Address(ip1->ip.v4, ip2->ip.v4)); case mDNSAddrType_IPv6: return (mDNSBool)(mDNSSameIPv6Address(ip1->ip.v6, ip2->ip.v6)); } } return(mDNSfalse); } mDNSexport mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip) { switch(ip->type) { case mDNSAddrType_IPv4: return (mDNSBool)(mDNSSameIPv4Address(ip->ip.v4, AllDNSLinkGroup_v4.ip.v4)); case mDNSAddrType_IPv6: return (mDNSBool)(mDNSSameIPv6Address(ip->ip.v6, AllDNSLinkGroup_v6.ip.v6)); default: return(mDNSfalse); } } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Domain Name Utility Functions #endif #if !APPLE_OSX_mDNSResponder mDNSexport mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b) { int i; const int len = *a++; if (len > MAX_DOMAIN_LABEL) { debugf("Malformed label (too long)"); return(mDNSfalse); } if (len != *b++) return(mDNSfalse); for (i=0; ic; const mDNSu8 * b = d2->c; const mDNSu8 *const max = d1->c + MAX_DOMAIN_NAME; // Maximum that's valid while (*a || *b) { if (a + 1 + *a >= max) { debugf("Malformed domain name (more than 256 characters)"); return(mDNSfalse); } if (!SameDomainLabel(a, b)) return(mDNSfalse); a += 1 + *a; b += 1 + *b; } return(mDNStrue); } mDNSexport mDNSBool SameDomainNameCS(const domainname *const d1, const domainname *const d2) { mDNSu16 l1 = DomainNameLength(d1); mDNSu16 l2 = DomainNameLength(d2); return(l1 <= MAX_DOMAIN_NAME && l1 == l2 && mDNSPlatformMemSame(d1, d2, l1)); } mDNSexport mDNSBool IsLocalDomain(const domainname *d) { // Domains that are defined to be resolved via link-local multicast are: // local., 254.169.in-addr.arpa., and {8,9,A,B}.E.F.ip6.arpa. static const domainname *nL = (const domainname*)"\x5" "local"; static const domainname *nR = (const domainname*)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa"; static const domainname *n8 = (const domainname*)"\x1" "8" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; static const domainname *n9 = (const domainname*)"\x1" "9" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; static const domainname *nA = (const domainname*)"\x1" "a" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; static const domainname *nB = (const domainname*)"\x1" "b" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; const domainname *d1, *d2, *d3, *d4, *d5; // Top-level domain, second-level domain, etc. d1 = d2 = d3 = d4 = d5 = mDNSNULL; while (d->c[0]) { d5 = d4; d4 = d3; d3 = d2; d2 = d1; d1 = d; d = (const domainname*)(d->c + 1 + d->c[0]); } if (d1 && SameDomainName(d1, nL)) return(mDNStrue); if (d4 && SameDomainName(d4, nR)) return(mDNStrue); if (d5 && SameDomainName(d5, n8)) return(mDNStrue); if (d5 && SameDomainName(d5, n9)) return(mDNStrue); if (d5 && SameDomainName(d5, nA)) return(mDNStrue); if (d5 && SameDomainName(d5, nB)) return(mDNStrue); return(mDNSfalse); } mDNSexport const mDNSu8 *LastLabel(const domainname *d) { const mDNSu8 *p = d->c; while (d->c[0]) { p = d->c; d = (const domainname*)(d->c + 1 + d->c[0]); } return(p); } // Returns length of a domain name INCLUDING the byte for the final null label // e.g. for the root label "." it returns one // For the FQDN "com." it returns 5 (length byte, three data bytes, final zero) // Legal results are 1 (just root label) to 256 (MAX_DOMAIN_NAME) // If the given domainname is invalid, result is 257 (MAX_DOMAIN_NAME+1) mDNSexport mDNSu16 DomainNameLengthLimit(const domainname *const name, const mDNSu8 *limit) { const mDNSu8 *src = name->c; while (src < limit && *src <= MAX_DOMAIN_LABEL) { if (*src == 0) return((mDNSu16)(src - name->c + 1)); src += 1 + *src; } return(MAX_DOMAIN_NAME+1); } // CompressedDomainNameLength returns the length of a domain name INCLUDING the byte // for the final null label, e.g. for the root label "." it returns one. // E.g. for the FQDN "foo.com." it returns 9 // (length, three data bytes, length, three more data bytes, final zero). // In the case where a parent domain name is provided, and the given name is a child // of that parent, CompressedDomainNameLength returns the length of the prefix portion // of the child name, plus TWO bytes for the compression pointer. // E.g. for the name "foo.com." with parent "com.", it returns 6 // (length, three data bytes, two-byte compression pointer). mDNSexport mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent) { const mDNSu8 *src = name->c; if (parent && parent->c[0] == 0) parent = mDNSNULL; while (*src) { if (*src > MAX_DOMAIN_LABEL) return(MAX_DOMAIN_NAME+1); if (parent && SameDomainName((const domainname *)src, parent)) return((mDNSu16)(src - name->c + 2)); src += 1 + *src; if (src - name->c >= MAX_DOMAIN_NAME) return(MAX_DOMAIN_NAME+1); } return((mDNSu16)(src - name->c + 1)); } // CountLabels() returns number of labels in name, excluding final root label // (e.g. for "apple.com." CountLabels returns 2.) mDNSexport int CountLabels(const domainname *d) { int count = 0; const mDNSu8 *ptr; for (ptr = d->c; *ptr; ptr = ptr + ptr[0] + 1) count++; return count; } // SkipLeadingLabels skips over the first 'skip' labels in the domainname, // returning a pointer to the suffix with 'skip' labels removed. mDNSexport const domainname *SkipLeadingLabels(const domainname *d, int skip) { while (skip > 0 && d->c[0]) { d = (const domainname *)(d->c + 1 + d->c[0]); skip--; } return(d); } // AppendLiteralLabelString appends a single label to an existing (possibly empty) domainname. // The C string contains the label as-is, with no escaping, etc. // Any dots in the name are literal dots, not label separators // If successful, AppendLiteralLabelString returns a pointer to the next unused byte // in the domainname bufer (i.e. the next byte after the terminating zero). // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) // AppendLiteralLabelString returns mDNSNULL. mDNSexport mDNSu8 *AppendLiteralLabelString(domainname *const name, const char *cstr) { mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name const mDNSu8 *const lim1 = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero) const mDNSu8 *const lim2 = ptr + 1 + MAX_DOMAIN_LABEL; const mDNSu8 *const lim = (lim1 < lim2) ? lim1 : lim2; mDNSu8 *lengthbyte = ptr++; // Record where the length is going to go while (*cstr && ptr < lim) *ptr++ = (mDNSu8)*cstr++; // Copy the data *lengthbyte = (mDNSu8)(ptr - lengthbyte - 1); // Fill in the length byte *ptr++ = 0; // Put the null root label on the end if (*cstr) return(mDNSNULL); // Failure: We didn't successfully consume all input else return(ptr); // Success: return new value of ptr } // AppendDNSNameString appends zero or more labels to an existing (possibly empty) domainname. // The C string is in conventional DNS syntax: // Textual labels, escaped as necessary using the usual DNS '\' notation, separated by dots. // If successful, AppendDNSNameString returns a pointer to the next unused byte // in the domainname bufer (i.e. the next byte after the terminating zero). // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) // AppendDNSNameString returns mDNSNULL. mDNSexport mDNSu8 *AppendDNSNameString(domainname *const name, const char *cstring) { const char *cstr = cstring; mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name const mDNSu8 *const lim = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero) while (*cstr && ptr < lim) // While more characters, and space to put them... { mDNSu8 *lengthbyte = ptr++; // Record where the length is going to go if (*cstr == '.') { LogMsg("AppendDNSNameString: Illegal empty label in name \"%s\"", cstring); return(mDNSNULL); } while (*cstr && *cstr != '.' && ptr < lim) // While we have characters in the label... { mDNSu8 c = (mDNSu8)*cstr++; // Read the character if (c == '\\') // If escape character, check next character { if (*cstr == '\0') break; // If this is the end of the string, then break c = (mDNSu8)*cstr++; // Assume we'll just take the next character if (mDNSIsDigit(cstr[-1]) && mDNSIsDigit(cstr[0]) && mDNSIsDigit(cstr[1])) { // If three decimal digits, int v0 = cstr[-1] - '0'; // then interpret as three-digit decimal int v1 = cstr[ 0] - '0'; int v2 = cstr[ 1] - '0'; int val = v0 * 100 + v1 * 10 + v2; if (val <= 255) { c = (mDNSu8)val; cstr += 2; } // If valid three-digit decimal value, use it } } *ptr++ = c; // Write the character } if (*cstr == '.') cstr++; // Skip over the trailing dot (if present) if (ptr - lengthbyte - 1 > MAX_DOMAIN_LABEL) // If illegal label, abort return(mDNSNULL); *lengthbyte = (mDNSu8)(ptr - lengthbyte - 1); // Fill in the length byte } *ptr++ = 0; // Put the null root label on the end if (*cstr) return(mDNSNULL); // Failure: We didn't successfully consume all input else return(ptr); // Success: return new value of ptr } // AppendDomainLabel appends a single label to a name. // If successful, AppendDomainLabel returns a pointer to the next unused byte // in the domainname bufer (i.e. the next byte after the terminating zero). // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) // AppendDomainLabel returns mDNSNULL. mDNSexport mDNSu8 *AppendDomainLabel(domainname *const name, const domainlabel *const label) { int i; mDNSu8 *ptr = name->c + DomainNameLength(name) - 1; // Check label is legal if (label->c[0] > MAX_DOMAIN_LABEL) return(mDNSNULL); // Check that ptr + length byte + data bytes + final zero does not exceed our limit if (ptr + 1 + label->c[0] + 1 > name->c + MAX_DOMAIN_NAME) return(mDNSNULL); for (i=0; i<=label->c[0]; i++) *ptr++ = label->c[i]; // Copy the label data *ptr++ = 0; // Put the null root label on the end return(ptr); } mDNSexport mDNSu8 *AppendDomainName(domainname *const name, const domainname *const append) { mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name const mDNSu8 *const lim = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero) const mDNSu8 * src = append->c; while (src[0]) { int i; if (ptr + 1 + src[0] > lim) return(mDNSNULL); for (i=0; i<=src[0]; i++) *ptr++ = src[i]; *ptr = 0; // Put the null root label on the end src += i; } return(ptr); } // MakeDomainLabelFromLiteralString makes a single domain label from a single literal C string (with no escaping). // If successful, MakeDomainLabelFromLiteralString returns mDNStrue. // If unable to convert the whole string to a legal domain label (i.e. because length is more than 63 bytes) then // MakeDomainLabelFromLiteralString makes a legal domain label from the first 63 bytes of the string and returns mDNSfalse. // In some cases silently truncated oversized names to 63 bytes is acceptable, so the return result may be ignored. // In other cases silent truncation may not be acceptable, so in those cases the calling function needs to check the return result. mDNSexport mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr) { mDNSu8 * ptr = label->c + 1; // Where we're putting it const mDNSu8 *const limit = label->c + 1 + MAX_DOMAIN_LABEL; // The maximum we can put while (*cstr && ptr < limit) *ptr++ = (mDNSu8)*cstr++; // Copy the label label->c[0] = (mDNSu8)(ptr - label->c - 1); // Set the length byte return(*cstr == 0); // Return mDNStrue if we successfully consumed all input } // MakeDomainNameFromDNSNameString makes a native DNS-format domainname from a C string. // The C string is in conventional DNS syntax: // Textual labels, escaped as necessary using the usual DNS '\' notation, separated by dots. // If successful, MakeDomainNameFromDNSNameString returns a pointer to the next unused byte // in the domainname bufer (i.e. the next byte after the terminating zero). // If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) // MakeDomainNameFromDNSNameString returns mDNSNULL. mDNSexport mDNSu8 *MakeDomainNameFromDNSNameString(domainname *const name, const char *cstr) { name->c[0] = 0; // Make an empty domain name return(AppendDNSNameString(name, cstr)); // And then add this string to it } mDNSexport char *ConvertDomainLabelToCString_withescape(const domainlabel *const label, char *ptr, char esc) { const mDNSu8 * src = label->c; // Domain label we're reading const mDNSu8 len = *src++; // Read length of this (non-null) label const mDNSu8 *const end = src + len; // Work out where the label ends if (len > MAX_DOMAIN_LABEL) return(mDNSNULL); // If illegal label, abort while (src < end) // While we have characters in the label { mDNSu8 c = *src++; if (esc) { if (c == '.' || c == esc) // If character is a dot or the escape character *ptr++ = esc; // Output escape character else if (c <= ' ') // If non-printing ascii, { // Output decimal escape sequence *ptr++ = esc; *ptr++ = (char) ('0' + (c / 100) ); *ptr++ = (char) ('0' + (c / 10) % 10); c = (mDNSu8)('0' + (c ) % 10); } } *ptr++ = (char)c; // Copy the character } *ptr = 0; // Null-terminate the string return(ptr); // and return } // Note: To guarantee that there will be no possible overrun, cstr must be at least MAX_ESCAPED_DOMAIN_NAME (1009 bytes) mDNSexport char *ConvertDomainNameToCString_withescape(const domainname *const name, char *ptr, char esc) { const mDNSu8 *src = name->c; // Domain name we're reading const mDNSu8 *const max = name->c + MAX_DOMAIN_NAME; // Maximum that's valid if (*src == 0) *ptr++ = '.'; // Special case: For root, just write a dot while (*src) // While more characters in the domain name { if (src + 1 + *src >= max) return(mDNSNULL); ptr = ConvertDomainLabelToCString_withescape((const domainlabel *)src, ptr, esc); if (!ptr) return(mDNSNULL); src += 1 + *src; *ptr++ = '.'; // Write the dot after the label } *ptr++ = 0; // Null-terminate the string return(ptr); // and return } // RFC 1034 rules: // Host names must start with a letter, end with a letter or digit, // and have as interior characters only letters, digits, and hyphen. // This was subsequently modified in RFC 1123 to allow the first character to be either a letter or a digit mDNSexport void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel) { const mDNSu8 * src = &UTF8Name[1]; const mDNSu8 *const end = &UTF8Name[1] + UTF8Name[0]; mDNSu8 * ptr = &hostlabel->c[1]; const mDNSu8 *const lim = &hostlabel->c[1] + MAX_DOMAIN_LABEL; while (src < end) { // Delete apostrophes from source name if (src[0] == '\'') { src++; continue; } // Standard straight single quote if (src + 2 < end && src[0] == 0xE2 && src[1] == 0x80 && src[2] == 0x99) { src += 3; continue; } // Unicode curly apostrophe if (ptr < lim) { if (mDNSValidHostChar(*src, (ptr > &hostlabel->c[1]), (src < end-1))) *ptr++ = *src; else if (ptr > &hostlabel->c[1] && ptr[-1] != '-') *ptr++ = '-'; } src++; } while (ptr > &hostlabel->c[1] && ptr[-1] == '-') ptr--; // Truncate trailing '-' marks hostlabel->c[0] = (mDNSu8)(ptr - &hostlabel->c[1]); } mDNSexport mDNSu8 *ConstructServiceName(domainname *const fqdn, const domainlabel *name, const domainname *type, const domainname *const domain) { int i, len; mDNSu8 *dst = fqdn->c; const mDNSu8 *src; const char *errormsg; #if APPLE_OSX_mDNSResponder mDNSBool loggedUnderscore = mDNSfalse; static char typeBuf[MAX_ESCAPED_DOMAIN_NAME]; #endif // In the case where there is no name (and ONLY in that case), // a single-label subtype is allowed as the first label of a three-part "type" if (!name) { const mDNSu8 *s0 = type->c; if (s0[0] && s0[0] < 0x40) // If legal first label (at least one character, and no more than 63) { const mDNSu8 * s1 = s0 + 1 + s0[0]; if (s1[0] && s1[0] < 0x40) // and legal second label (at least one character, and no more than 63) { const mDNSu8 *s2 = s1 + 1 + s1[0]; if (s2[0] && s2[0] < 0x40 && s2[1+s2[0]] == 0) // and we have three and only three labels { static const mDNSu8 SubTypeLabel[5] = mDNSSubTypeLabel; src = s0; // Copy the first label len = *src; for (i=0; i <= len; i++) *dst++ = *src++; for (i=0; i < (int)sizeof(SubTypeLabel); i++) *dst++ = SubTypeLabel[i]; type = (const domainname *)s1; // Special support to enable the DNSServiceBrowse call made by Bonjour Browser // For these queries, we retract the "._sub" we just added between the subtype and the main type // Remove after Bonjour Browser is updated to use DNSServiceQueryRecord instead of DNSServiceBrowse if (SameDomainName((domainname*)s0, (const domainname*)"\x09_services\x07_dns-sd\x04_udp")) dst -= sizeof(SubTypeLabel); } } } } if (name && name->c[0]) { src = name->c; // Put the service name into the domain name len = *src; if (len >= 0x40) { errormsg = "Service instance name too long"; goto fail; } for (i=0; i<=len; i++) *dst++ = *src++; } else name = (domainlabel*)""; // Set this up to be non-null, to avoid errors if we have to call LogMsg() below src = type->c; // Put the service type into the domain name len = *src; if (len < 2 || len > 16) { LogMsg("Bad service type in %#s.%##s%##s Application protocol name must be underscore plus 1-15 characters. " "See ", name->c, type->c, domain->c); } if (len < 2 || len >= 0x40 || (len > 16 && !SameDomainName(domain, &localdomain))) return(mDNSNULL); if (src[1] != '_') { errormsg = "Application protocol name must begin with underscore"; goto fail; } for (i=2; i<=len; i++) { // Letters and digits are allowed anywhere if (mDNSIsLetter(src[i]) || mDNSIsDigit(src[i])) continue; // Hyphens are only allowed as interior characters // Underscores are not supposed to be allowed at all, but for backwards compatibility with some old products we do allow them, // with the same rule as hyphens if ((src[i] == '-' || src[i] == '_') && i > 2 && i < len) { #if APPLE_OSX_mDNSResponder if (src[i] == '_' && loggedUnderscore == mDNSfalse) { ConvertDomainNameToCString(type, typeBuf); LogInfo("ConstructServiceName: Service type with non-leading underscore %s", typeBuf); loggedUnderscore = mDNStrue; } #endif continue; } errormsg = "Application protocol name must contain only letters, digits, and hyphens"; goto fail; } for (i=0; i<=len; i++) *dst++ = *src++; len = *src; if (!ValidTransportProtocol(src)) { errormsg = "Transport protocol name must be _udp or _tcp"; goto fail; } for (i=0; i<=len; i++) *dst++ = *src++; if (*src) { errormsg = "Service type must have only two labels"; goto fail; } *dst = 0; if (!domain->c[0]) { errormsg = "Service domain must be non-empty"; goto fail; } if (SameDomainName(domain, (const domainname*)"\x05" "local" "\x04" "arpa")) { errormsg = "Illegal domain \"local.arpa.\" Use \"local.\" (or empty string)"; goto fail; } dst = AppendDomainName(fqdn, domain); if (!dst) { errormsg = "Service domain too long"; goto fail; } return(dst); fail: LogMsg("ConstructServiceName: %s: %#s.%##s%##s", errormsg, name->c, type->c, domain->c); return(mDNSNULL); } // A service name has the form: instance.application-protocol.transport-protocol.domain // DeconstructServiceName is currently fairly forgiving: It doesn't try to enforce character // set or length limits for the protocol names, and the final domain is allowed to be empty. // However, if the given FQDN doesn't contain at least three labels, // DeconstructServiceName will reject it and return mDNSfalse. mDNSexport mDNSBool DeconstructServiceName(const domainname *const fqdn, domainlabel *const name, domainname *const type, domainname *const domain) { int i, len; const mDNSu8 *src = fqdn->c; const mDNSu8 *max = fqdn->c + MAX_DOMAIN_NAME; mDNSu8 *dst; dst = name->c; // Extract the service name len = *src; if (!len) { debugf("DeconstructServiceName: FQDN empty!"); return(mDNSfalse); } if (len >= 0x40) { debugf("DeconstructServiceName: Instance name too long"); return(mDNSfalse); } for (i=0; i<=len; i++) *dst++ = *src++; dst = type->c; // Extract the service type len = *src; if (!len) { debugf("DeconstructServiceName: FQDN contains only one label!"); return(mDNSfalse); } if (len >= 0x40) { debugf("DeconstructServiceName: Application protocol name too long"); return(mDNSfalse); } if (src[1] != '_') { debugf("DeconstructServiceName: No _ at start of application protocol"); return(mDNSfalse); } for (i=0; i<=len; i++) *dst++ = *src++; len = *src; if (!len) { debugf("DeconstructServiceName: FQDN contains only two labels!"); return(mDNSfalse); } if (!ValidTransportProtocol(src)) { debugf("DeconstructServiceName: Transport protocol must be _udp or _tcp"); return(mDNSfalse); } for (i=0; i<=len; i++) *dst++ = *src++; *dst++ = 0; // Put terminator on the end of service type dst = domain->c; // Extract the service domain while (*src) { len = *src; if (len >= 0x40) { debugf("DeconstructServiceName: Label in service domain too long"); return(mDNSfalse); } if (src + 1 + len + 1 >= max) { debugf("DeconstructServiceName: Total service domain too long"); return(mDNSfalse); } for (i=0; i<=len; i++) *dst++ = *src++; } *dst++ = 0; // Put the null root label on the end return(mDNStrue); } mDNSexport mStatus DNSNameToLowerCase(domainname *d, domainname *result) { const mDNSu8 *a = d->c; mDNSu8 *b = result->c; const mDNSu8 *const max = d->c + MAX_DOMAIN_NAME; int i, len; while (*a) { if (a + 1 + *a >= max) { LogMsg("DNSNameToLowerCase: ERROR!! Malformed Domain name"); return mStatus_BadParamErr; } len = *a++; *b++ = len; for (i = 0; i < len; i++) { mDNSu8 ac = *a++; if (mDNSIsUpperCase(ac)) ac += 'a' - 'A'; *b++ = ac; } } *b = 0; return mStatus_NoError; } // Notes on UTF-8: // 0xxxxxxx represents a 7-bit ASCII value from 0x00 to 0x7F // 10xxxxxx is a continuation byte of a multi-byte character // 110xxxxx is the first byte of a 2-byte character (11 effective bits; values 0x 80 - 0x 800-1) // 1110xxxx is the first byte of a 3-byte character (16 effective bits; values 0x 800 - 0x 10000-1) // 11110xxx is the first byte of a 4-byte character (21 effective bits; values 0x 10000 - 0x 200000-1) // 111110xx is the first byte of a 5-byte character (26 effective bits; values 0x 200000 - 0x 4000000-1) // 1111110x is the first byte of a 6-byte character (31 effective bits; values 0x4000000 - 0x80000000-1) // // UTF-16 surrogate pairs are used in UTF-16 to encode values larger than 0xFFFF. // Although UTF-16 surrogate pairs are not supposed to appear in legal UTF-8, we want to be defensive // about that too. (See , "What are surrogates?") // The first of pair is a UTF-16 value in the range 0xD800-0xDBFF (11101101 1010xxxx 10xxxxxx in UTF-8), // and the second is a UTF-16 value in the range 0xDC00-0xDFFF (11101101 1011xxxx 10xxxxxx in UTF-8). mDNSexport mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max) { if (length > max) { mDNSu8 c1 = string[max]; // First byte after cut point mDNSu8 c2 = (max+1 < length) ? string[max+1] : (mDNSu8)0xB0; // Second byte after cut point length = max; // Trim length down while (length > 0) { // Check if the byte right after the chop point is a UTF-8 continuation byte, // or if the character right after the chop point is the second of a UTF-16 surrogate pair. // If so, then we continue to chop more bytes until we get to a legal chop point. mDNSBool continuation = ((c1 & 0xC0) == 0x80); mDNSBool secondsurrogate = (c1 == 0xED && (c2 & 0xF0) == 0xB0); if (!continuation && !secondsurrogate) break; c2 = c1; c1 = string[--length]; } // Having truncated characters off the end of our string, also cut off any residual white space while (length > 0 && string[length-1] <= ' ') length--; } return(length); } // Returns true if a rich text label ends in " (nnn)", or if an RFC 1034 // name ends in "-nnn", where n is some decimal number. mDNSexport mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText) { mDNSu16 l = name->c[0]; if (RichText) { if (l < 4) return mDNSfalse; // Need at least " (2)" if (name->c[l--] != ')') return mDNSfalse; // Last char must be ')' if (!mDNSIsDigit(name->c[l])) return mDNSfalse; // Preceeded by a digit l--; while (l > 2 && mDNSIsDigit(name->c[l])) l--; // Strip off digits return (name->c[l] == '(' && name->c[l - 1] == ' '); } else { if (l < 2) return mDNSfalse; // Need at least "-2" if (!mDNSIsDigit(name->c[l])) return mDNSfalse; // Last char must be a digit l--; while (l > 2 && mDNSIsDigit(name->c[l])) l--; // Strip off digits return (name->c[l] == '-'); } } // removes an auto-generated suffix (appended on a name collision) from a label. caller is // responsible for ensuring that the label does indeed contain a suffix. returns the number // from the suffix that was removed. mDNSexport mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText) { mDNSu32 val = 0, multiplier = 1; // Chop closing parentheses from RichText suffix if (RichText && name->c[0] >= 1 && name->c[name->c[0]] == ')') name->c[0]--; // Get any existing numerical suffix off the name while (mDNSIsDigit(name->c[name->c[0]])) { val += (name->c[name->c[0]] - '0') * multiplier; multiplier *= 10; name->c[0]--; } // Chop opening parentheses or dash from suffix if (RichText) { if (name->c[0] >= 2 && name->c[name->c[0]] == '(' && name->c[name->c[0]-1] == ' ') name->c[0] -= 2; } else { if (name->c[0] >= 1 && name->c[name->c[0]] == '-') name->c[0] -= 1; } return(val); } // appends a numerical suffix to a label, with the number following a whitespace and enclosed // in parentheses (rich text) or following two consecutive hyphens (RFC 1034 domain label). mDNSexport void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText) { mDNSu32 divisor = 1, chars = 2; // Shortest possible RFC1034 name suffix is 2 characters ("-2") if (RichText) chars = 4; // Shortest possible RichText suffix is 4 characters (" (2)") // Truncate trailing spaces from RichText names if (RichText) while (name->c[name->c[0]] == ' ') name->c[0]--; while (divisor < 0xFFFFFFFFUL/10 && val >= divisor * 10) { divisor *= 10; chars++; } name->c[0] = (mDNSu8) TruncateUTF8ToLength(name->c+1, name->c[0], MAX_DOMAIN_LABEL - chars); if (RichText) { name->c[++name->c[0]] = ' '; name->c[++name->c[0]] = '('; } else { name->c[++name->c[0]] = '-'; } while (divisor) { name->c[++name->c[0]] = (mDNSu8)('0' + val / divisor); val %= divisor; divisor /= 10; } if (RichText) name->c[++name->c[0]] = ')'; } mDNSexport void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText) { mDNSu32 val = 0; if (LabelContainsSuffix(name, RichText)) val = RemoveLabelSuffix(name, RichText); // If no existing suffix, start by renaming "Foo" as "Foo (2)" or "Foo-2" as appropriate. // If existing suffix in the range 2-9, increment it. // If we've had ten conflicts already, there are probably too many hosts trying to use the same name, // so add a random increment to improve the chances of finding an available name next time. if (val == 0) val = 2; else if (val < 10) val++; else val += 1 + mDNSRandom(99); AppendLabelSuffix(name, val, RichText); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Resource Record Utility Functions #endif // Set up a AuthRecord with sensible default values. // These defaults may be overwritten with new values before mDNS_Register is called mDNSexport void mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID, mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, AuthRecType artype, mDNSRecordCallback Callback, void *Context) { // // LocalOnly auth record can be created with LocalOnly InterfaceID or a valid InterfaceID. // Most of the applications normally create with LocalOnly InterfaceID and we store them as // such, so that we can deliver the response to questions that specify LocalOnly InterfaceID. // LocalOnly resource records can also be created with valid InterfaceID which happens today // when we create LocalOnly records for /etc/hosts. if (InterfaceID == mDNSInterface_LocalOnly && artype != AuthRecordLocalOnly) { LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch LocalOnly record InterfaceID %p called with artype %d", InterfaceID, artype); } else if (InterfaceID == mDNSInterface_P2P && artype != AuthRecordP2P) { LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch P2P record InterfaceID %p called with artype %d", InterfaceID, artype); } else if (!InterfaceID && (artype == AuthRecordP2P || artype == AuthRecordLocalOnly)) { LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch InterfaceAny record InterfaceID %p called with artype %d", InterfaceID, artype); } // Don't try to store a TTL bigger than we can represent in platform time units if (ttl > 0x7FFFFFFFUL / mDNSPlatformOneSecond) ttl = 0x7FFFFFFFUL / mDNSPlatformOneSecond; else if (ttl == 0) // And Zero TTL is illegal ttl = DefaultTTLforRRType(rrtype); // Field Group 1: The actual information pertaining to this resource record rr->resrec.RecordType = RecordType; rr->resrec.InterfaceID = InterfaceID; rr->resrec.name = &rr->namestorage; rr->resrec.rrtype = rrtype; rr->resrec.rrclass = kDNSClass_IN; rr->resrec.rroriginalttl = ttl; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) rr->resrec.dnsservice = NULL; #else rr->resrec.rDNSServer = mDNSNULL; #endif // rr->resrec.rdlength = MUST set by client and/or in mDNS_Register_internal // rr->resrec.rdestimate = set in mDNS_Register_internal // rr->resrec.rdata = MUST be set by client if (RDataStorage) rr->resrec.rdata = RDataStorage; else { rr->resrec.rdata = &rr->rdatastorage; rr->resrec.rdata->MaxRDLength = sizeof(RDataBody); } // Field Group 2: Persistent metadata for Authoritative Records rr->Additional1 = mDNSNULL; rr->Additional2 = mDNSNULL; rr->DependentOn = mDNSNULL; rr->RRSet = mDNSNULL; rr->RecordCallback = Callback; rr->RecordContext = Context; rr->AutoTarget = Target_Manual; rr->AllowRemoteQuery = mDNSfalse; rr->ForceMCast = mDNSfalse; rr->WakeUp = zeroOwner; rr->AddressProxy = zeroAddr; rr->TimeRcvd = 0; rr->TimeExpire = 0; rr->ARType = artype; rr->AuthFlags = 0; // Field Group 3: Transient state for Authoritative Records (set in mDNS_Register_internal) // Field Group 4: Transient uDNS state for Authoritative Records (set in mDNS_Register_internal) // For now, until the uDNS code is fully integrated, it's helpful to zero the uDNS state fields here too, just in case // (e.g. uDNS_RegisterService short-circuits the usual mDNS_Register_internal record registration calls, so a bunch // of fields don't get set up properly. In particular, if we don't zero rr->QueuedRData then the uDNS code crashes.) rr->state = regState_Zero; rr->uselease = 0; rr->expire = 0; rr->Private = 0; rr->updateid = zeroID; rr->zone = rr->resrec.name; rr->nta = mDNSNULL; rr->tcp = mDNSNULL; rr->OrigRData = 0; rr->OrigRDLen = 0; rr->InFlightRData = 0; rr->InFlightRDLen = 0; rr->QueuedRData = 0; rr->QueuedRDLen = 0; mDNSPlatformMemZero(&rr->NATinfo, sizeof(rr->NATinfo)); rr->SRVChanged = mDNSfalse; rr->mState = mergeState_Zero; rr->namestorage.c[0] = 0; // MUST be set by client before calling mDNS_Register() } mDNSexport void mDNS_SetupQuestion(DNSQuestion *const q, const mDNSInterfaceID InterfaceID, const domainname *const name, const mDNSu16 qtype, mDNSQuestionCallback *const callback, void *const context) { q->InterfaceID = InterfaceID; q->flags = 0; AssignDomainName(&q->qname, name); q->qtype = qtype; q->qclass = kDNSClass_IN; q->LongLived = (qtype == kDNSType_PTR); q->ExpectUnique = (qtype != kDNSType_PTR); q->ForceMCast = mDNSfalse; q->ReturnIntermed = mDNSfalse; q->SuppressUnusable = mDNSfalse; q->AppendSearchDomains = 0; q->TimeoutQuestion = 0; q->WakeOnResolve = 0; q->UseBackgroundTraffic = mDNSfalse; q->ProxyQuestion = 0; q->pid = mDNSPlatformGetPID(); q->euid = 0; q->BlockedByPolicy = mDNSfalse; q->ServiceID = -1; q->QuestionCallback = callback; q->QuestionContext = context; } mDNSexport mDNSu32 RDataHashValue(const ResourceRecord *const rr) { int len = rr->rdlength; const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data; const mDNSu8 *ptr = rdb->data; mDNSu32 sum = 0; switch(rr->rrtype) { case kDNSType_NS: case kDNSType_MD: case kDNSType_MF: case kDNSType_CNAME: case kDNSType_MB: case kDNSType_MG: case kDNSType_MR: case kDNSType_PTR: case kDNSType_NSAP_PTR: case kDNSType_DNAME: return DomainNameHashValue(&rdb->name); case kDNSType_SOA: return rdb->soa.serial + rdb->soa.refresh + rdb->soa.retry + rdb->soa.expire + rdb->soa.min + DomainNameHashValue(&rdb->soa.mname) + DomainNameHashValue(&rdb->soa.rname); case kDNSType_MX: case kDNSType_AFSDB: case kDNSType_RT: case kDNSType_KX: return DomainNameHashValue(&rdb->mx.exchange); case kDNSType_MINFO: case kDNSType_RP: return DomainNameHashValue(&rdb->rp.mbox) + DomainNameHashValue(&rdb->rp.txt); case kDNSType_PX: return DomainNameHashValue(&rdb->px.map822) + DomainNameHashValue(&rdb->px.mapx400); case kDNSType_SRV: return DomainNameHashValue(&rdb->srv.target); case kDNSType_OPT: return 0; // OPT is a pseudo-RR container structure; makes no sense to compare case kDNSType_NSEC: { int dlen; dlen = DomainNameLength((domainname *)rdb->data); sum = DomainNameHashValue((domainname *)rdb->data); ptr += dlen; len -= dlen; /* FALLTHROUGH */ } /* FALLTHROUGH */ default: { int i; for (i=0; i+1 < len; i+=2) { sum += (((mDNSu32)(ptr[i])) << 8) | ptr[i+1]; sum = (sum<<3) | (sum>>29); } if (i < len) { sum += ((mDNSu32)(ptr[i])) << 8; } return(sum); } } } // r1 has to be a full ResourceRecord including rrtype and rdlength // r2 is just a bare RDataBody, which MUST be the same rrtype and rdlength as r1 mDNSexport mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2, DomainNameComparisonFn *samename) { const RDataBody2 *const b1 = (RDataBody2 *)r1->rdata->u.data; const RDataBody2 *const b2 = (RDataBody2 *)r2; switch(r1->rrtype) { case kDNSType_NS: case kDNSType_MD: case kDNSType_MF: case kDNSType_CNAME: case kDNSType_MB: case kDNSType_MG: case kDNSType_MR: case kDNSType_PTR: case kDNSType_NSAP_PTR: case kDNSType_DNAME: return(SameDomainName(&b1->name, &b2->name)); case kDNSType_SOA: return (mDNSBool)( b1->soa.serial == b2->soa.serial && b1->soa.refresh == b2->soa.refresh && b1->soa.retry == b2->soa.retry && b1->soa.expire == b2->soa.expire && b1->soa.min == b2->soa.min && samename(&b1->soa.mname, &b2->soa.mname) && samename(&b1->soa.rname, &b2->soa.rname)); case kDNSType_MX: case kDNSType_AFSDB: case kDNSType_RT: case kDNSType_KX: return (mDNSBool)( b1->mx.preference == b2->mx.preference && samename(&b1->mx.exchange, &b2->mx.exchange)); case kDNSType_MINFO: case kDNSType_RP: return (mDNSBool)( samename(&b1->rp.mbox, &b2->rp.mbox) && samename(&b1->rp.txt, &b2->rp.txt)); case kDNSType_PX: return (mDNSBool)( b1->px.preference == b2->px.preference && samename(&b1->px.map822, &b2->px.map822) && samename(&b1->px.mapx400, &b2->px.mapx400)); case kDNSType_SRV: return (mDNSBool)( b1->srv.priority == b2->srv.priority && b1->srv.weight == b2->srv.weight && mDNSSameIPPort(b1->srv.port, b2->srv.port) && samename(&b1->srv.target, &b2->srv.target)); case kDNSType_OPT: return mDNSfalse; // OPT is a pseudo-RR container structure; makes no sense to compare case kDNSType_NSEC: { // If the "nxt" name changes in case, we want to delete the old // and store just the new one. If the caller passes in SameDomainCS for "samename", // we would return "false" when the only change between the two rdata is the case // change in "nxt". // // Note: rdlength of both the RData are same (ensured by the caller) and hence we can // use just r1->rdlength below int dlen1 = DomainNameLength((domainname *)b1->data); int dlen2 = DomainNameLength((domainname *)b2->data); return (mDNSBool)(dlen1 == dlen2 && samename((domainname *)b1->data, (domainname *)b2->data) && mDNSPlatformMemSame(b1->data + dlen1, b2->data + dlen2, r1->rdlength - dlen1)); } default: return(mDNSPlatformMemSame(b1->data, b2->data, r1->rdlength)); } } mDNSexport mDNSBool BitmapTypeCheck(mDNSu8 *bmap, int bitmaplen, mDNSu16 type) { int win, wlen; int wintype; // The window that this type belongs to. NSEC has 256 windows that // comprises of 256 types. wintype = type >> 8; while (bitmaplen > 0) { if (bitmaplen < 3) { LogInfo("BitmapTypeCheck: malformed nsec, bitmaplen %d short", bitmaplen); return mDNSfalse; } win = *bmap++; wlen = *bmap++; bitmaplen -= 2; if (bitmaplen < wlen || wlen < 1 || wlen > 32) { LogInfo("BitmapTypeCheck: malformed nsec, bitmaplen %d wlen %d, win %d", bitmaplen, wlen, win); return mDNSfalse; } if (win < 0 || win >= 256) { LogInfo("BitmapTypeCheck: malformed nsec, wlen %d", wlen); return mDNSfalse; } if (win == wintype) { // First byte in the window serves 0 to 7, the next one serves 8 to 15 and so on. // Calculate the right byte offset first. int boff = (type & 0xff ) >> 3; if (wlen <= boff) return mDNSfalse; // The last three bits values 0 to 7 corresponds to bit positions // within the byte. return (bmap[boff] & (0x80 >> (type & 7))); } else { // If the windows are ordered, then we could check to see // if wintype > win and then return early. bmap += wlen; bitmaplen -= wlen; } } return mDNSfalse; } // Don't call this function if the resource record is not NSEC. It will return false // which means that the type does not exist. mDNSexport mDNSBool RRAssertsExistence(const ResourceRecord *const rr, mDNSu16 type) { const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data; mDNSu8 *nsec = (mDNSu8 *)rdb->data; int len, bitmaplen; mDNSu8 *bmap; if (rr->rrtype != kDNSType_NSEC) return mDNSfalse; len = DomainNameLength((domainname *)nsec); bitmaplen = rr->rdlength - len; bmap = nsec + len; return (BitmapTypeCheck(bmap, bitmaplen, type)); } // Don't call this function if the resource record is not NSEC. It will return false // which means that the type exists. mDNSexport mDNSBool RRAssertsNonexistence(const ResourceRecord *const rr, mDNSu16 type) { if (rr->rrtype != kDNSType_NSEC) return mDNSfalse; return !RRAssertsExistence(rr, type); } // ResourceRecordAnswersQuestion returns mDNStrue if the given resource record is a valid answer to the given question. // SameNameRecordAnswersQuestion is the same, except it skips the expensive SameDomainName() call. // SameDomainName() is generally cheap when the names don't match, but expensive when they do match, // because it has to check all the way to the end of the names to be sure. // In cases where we know in advance that the names match it's especially advantageous to skip the // SameDomainName() call because that's precisely the time when it's most expensive and least useful. mDNSlocal mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord *const rr, mDNSBool isAuthRecord, const DNSQuestion *const q) { mDNSBool checkType = mDNStrue; // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records // are handled in LocalOnlyRecordAnswersQuestion if (LocalOnlyOrP2PInterface(rr->InterfaceID)) { LogMsg("SameNameRecordAnswersQuestion: ERROR!! called with LocalOnly ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID); return mDNSfalse; } if (q->Suppressed) return mDNSfalse; if (rr->InterfaceID && q->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && rr->InterfaceID != q->InterfaceID) return(mDNSfalse); // Resource record received via unicast, the resolver group ID should match ? if (!isAuthRecord && !rr->InterfaceID) { if (mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (rr->dnsservice != q->dnsservice) return(mDNSfalse); #else const mDNSu32 idr = rr->rDNSServer ? rr->rDNSServer->resGroupID : 0; const mDNSu32 idq = q->qDNSServer ? q->qDNSServer->resGroupID : 0; if (idr != idq) return(mDNSfalse); #endif } // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); // CNAME answers question of any type and a negative cache record should not prevent us from querying other // valid types at the same name. if (rr->rrtype == kDNSType_CNAME && rr->RecordType == kDNSRecordTypePacketNegative && rr->rrtype != q->qtype) return mDNSfalse; #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) if (enables_dnssec_validation(q) && record_type_answers_dnssec_question(rr, q->qtype)) checkType = mDNSfalse; #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. if (checkType && !RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); #if APPLE_OSX_mDNSResponder if (!mDNSPlatformValidRecordForQuestion(rr, q)) return mDNSfalse; #endif // APPLE_OSX_mDNSResponder return(mDNStrue); } mDNSexport mDNSBool SameNameCacheRecordAnswersQuestion(const CacheRecord *const cr, const DNSQuestion *const q) { return SameNameRecordAnswersQuestion(&cr->resrec, mDNSfalse, q); } mDNSlocal mDNSBool RecordAnswersQuestion(const ResourceRecord *const rr, mDNSBool isAuthRecord, const DNSQuestion *const q) { if (!SameNameRecordAnswersQuestion(rr, isAuthRecord, q)) return mDNSfalse; return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); } mDNSexport mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q) { return RecordAnswersQuestion(rr, mDNSfalse, q); } mDNSexport mDNSBool AuthRecordAnswersQuestion(const AuthRecord *const ar, const DNSQuestion *const q) { return RecordAnswersQuestion(&ar->resrec, mDNStrue, q); } mDNSexport mDNSBool CacheRecordAnswersQuestion(const CacheRecord *const cr, const DNSQuestion *const q) { return RecordAnswersQuestion(&cr->resrec, mDNSfalse, q); } // We have a separate function to handle LocalOnly AuthRecords because they can be created with // a valid InterfaceID (e.g., scoped /etc/hosts) and can be used to answer unicast questions unlike // multicast resource records (which has a valid InterfaceID) which can't be used to answer // unicast questions. ResourceRecordAnswersQuestion/SameNameRecordAnswersQuestion can't tell whether // a resource record is multicast or LocalOnly by just looking at the ResourceRecord because // LocalOnly records are truly identified by ARType in the AuthRecord. As P2P and LocalOnly record // are kept in the same hash table, we use the same function to make it easy for the callers when // they walk the hash table to answer LocalOnly/P2P questions // mDNSexport mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord *const ar, const DNSQuestion *const q) { ResourceRecord *rr = &ar->resrec; // mDNSInterface_Any questions can be answered with LocalOnly/P2P records in this function. AuthRecord_Any // records are handled in ResourceRecordAnswersQuestion/SameNameRecordAnswersQuestion if (RRAny(ar)) { LogMsg("LocalOnlyRecordAnswersQuestion: ERROR!! called with regular AuthRecordAny %##s", rr->name->c); return mDNSfalse; } // Questions with mDNSInterface_LocalOnly InterfaceID should be answered with all resource records that are // *local* to the machine. These include resource records that have InterfaceID set to mDNSInterface_LocalOnly, // mDNSInterface_Any and any other real InterfaceID. Hence, LocalOnly questions should not be checked against // the InterfaceID in the resource record. if (rr->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && ((q->InterfaceID && rr->InterfaceID != q->InterfaceID) || (!q->InterfaceID && !LocalOnlyOrP2PInterface(rr->InterfaceID)))) return(mDNSfalse); // Entries in /etc/hosts are added as LocalOnly resource records. The LocalOnly resource records // may have a scope e.g., fe80::1%en0. The question may be scoped or not: the InterfaceID may be set // to mDNSInterface_Any, mDNSInterface_LocalOnly or a real InterfaceID (scoped). // // 1) Question: Any, LocalOnly Record: no scope. This question should be answered with this record. // // 2) Question: Any, LocalOnly Record: scoped. This question should be answered with the record because // traditionally applications never specify scope e.g., getaddrinfo, but need to be able // to get to /etc/hosts entries. // // 3) Question: Scoped (LocalOnly or InterfaceID), LocalOnly Record: no scope. This is the inverse of (2). // If we register a LocalOnly record, we need to answer a LocalOnly question. If the /etc/hosts has a // non scoped entry, it may not make sense to answer a scoped question. But we can't tell these two // cases apart. As we currently answer LocalOnly question with LocalOnly record, we continue to do so. // // 4) Question: Scoped (LocalOnly or InterfaceID), LocalOnly Record: scoped. LocalOnly questions should be // answered with any resource record where as if it has a valid InterfaceID, the scope should match. // // (1) and (2) is bypassed because we check for a non-NULL InterfaceID above. For (3), the InterfaceID is NULL // and hence bypassed above. For (4) we bypassed LocalOnly questions and checked the scope of the record // against the question. // // For P2P, InterfaceIDs of the question and the record should match. // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question. // LocalOnly authoritative answers are exempt. LocalOnly authoritative answers are used for /etc/host entries. // We don't want a local process to be able to create a fake LocalOnly address record for "www.bigbank.com" which would then // cause other applications (e.g. Safari) to connect to the wrong address. The rpc to register records filters out records // with names that don't end in local and have mDNSInterface_LocalOnly set. // // Note: The check is bypassed for LocalOnly and for P2P it is not needed as only .local records are registered and for // a question to match its names, it also has to end in .local and that question can't be a unicast question (See // Question_uDNS macro and its usage). As P2P does not enforce .local only registrations we still make this check // and also makes it future proof. if (ar->ARType != AuthRecordLocalOnly && rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. if (!RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); } mDNSexport mDNSBool AnyTypeRecordAnswersQuestion(const AuthRecord *const ar, const DNSQuestion *const q) { const ResourceRecord *const rr = &ar->resrec; // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records // are handled in LocalOnlyRecordAnswersQuestion if (LocalOnlyOrP2PInterface(rr->InterfaceID)) { LogMsg("AnyTypeRecordAnswersQuestion: ERROR!! called with LocalOnly ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID); return mDNSfalse; } if (rr->InterfaceID && q->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && rr->InterfaceID != q->InterfaceID) return(mDNSfalse); // Resource record received via unicast, the resolver group ID should match ? // Note that Auth Records are normally setup with NULL InterfaceID and // both the DNSServers are assumed to be NULL in that case if (!rr->InterfaceID) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (rr->dnsservice != q->dnsservice) return(mDNSfalse); #else const mDNSu32 idr = rr->rDNSServer ? rr->rDNSServer->resGroupID : 0; const mDNSu32 idq = q->qDNSServer ? q->qDNSServer->resGroupID : 0; if (idr != idq) return(mDNSfalse); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (!mDNSPlatformValidRecordForInterface(ar, q->InterfaceID)) return(mDNSfalse); #endif } // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); } // This is called with both unicast resource record and multicast resource record. The question that // received the unicast response could be the regular unicast response from a DNS server or a response // to a mDNS QU query. The main reason we need this function is that we can't compare DNSServers between the // question and the resource record because the resource record is not completely initialized in // mDNSCoreReceiveResponse when this function is called. mDNSexport mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord *const rr, const DNSQuestion *const q) { mDNSBool checkType = mDNStrue; if (q->Suppressed) return mDNSfalse; // For resource records created using multicast, the InterfaceIDs have to match if (rr->InterfaceID && q->InterfaceID && rr->InterfaceID != q->InterfaceID) return(mDNSfalse); // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question. if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) if (enables_dnssec_validation(q) && record_type_answers_dnssec_question(rr, q->qtype)) checkType = mDNSfalse; #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. if (checkType && !RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); } mDNSexport mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate) { const RDataBody2 *const rd = (RDataBody2 *)rr->rdata->u.data; const domainname *const name = estimate ? rr->name : mDNSNULL; if (rr->rrclass == kDNSQClass_ANY) return(rr->rdlength); // Used in update packets to mean "Delete An RRset" (RFC 2136) else switch (rr->rrtype) { case kDNSType_A: return(sizeof(rd->ipv4)); case kDNSType_NS: case kDNSType_CNAME: case kDNSType_PTR: case kDNSType_DNAME: return(CompressedDomainNameLength(&rd->name, name)); case kDNSType_SOA: return (mDNSu16)(CompressedDomainNameLength(&rd->soa.mname, name) + CompressedDomainNameLength(&rd->soa.rname, name) + 5 * sizeof(mDNSOpaque32)); case kDNSType_NULL: case kDNSType_TSIG: case kDNSType_TXT: case kDNSType_X25: case kDNSType_ISDN: case kDNSType_LOC: case kDNSType_DHCID: return(rr->rdlength); // Not self-describing, so have to just trust rdlength case kDNSType_HINFO: return (mDNSu16)(2 + (int)rd->data[0] + (int)rd->data[1 + (int)rd->data[0]]); case kDNSType_MX: case kDNSType_AFSDB: case kDNSType_RT: case kDNSType_KX: return (mDNSu16)(2 + CompressedDomainNameLength(&rd->mx.exchange, name)); case kDNSType_MINFO: case kDNSType_RP: return (mDNSu16)(CompressedDomainNameLength(&rd->rp.mbox, name) + CompressedDomainNameLength(&rd->rp.txt, name)); case kDNSType_PX: return (mDNSu16)(2 + CompressedDomainNameLength(&rd->px.map822, name) + CompressedDomainNameLength(&rd->px.mapx400, name)); case kDNSType_AAAA: return(sizeof(rd->ipv6)); case kDNSType_SRV: return (mDNSu16)(6 + CompressedDomainNameLength(&rd->srv.target, name)); case kDNSType_OPT: return(rr->rdlength); case kDNSType_NSEC: { domainname *next = (domainname *)rd->data; int dlen = DomainNameLength(next); // if (UNICAST_NSEC(rr)) return (mDNSu16)(CompressedDomainNameLength(next, name) + rr->rdlength - dlen); else return (mDNSu16)((estimate ? 2 : dlen) + rr->rdlength - dlen); } default: debugf("Warning! Don't know how to get length of resource type %d", rr->rrtype); return(rr->rdlength); } } // When a local client registers (or updates) a record, we use this routine to do some simple validation checks // to help reduce the risk of bogus malformed data on the network mDNSexport mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd) { mDNSu16 len; switch(rrtype) { case kDNSType_A: return(rdlength == sizeof(mDNSv4Addr)); case kDNSType_NS: // Same as PTR case kDNSType_MD: // Same as PTR case kDNSType_MF: // Same as PTR case kDNSType_CNAME: // Same as PTR //case kDNSType_SOA not checked case kDNSType_MB: // Same as PTR case kDNSType_MG: // Same as PTR case kDNSType_MR: // Same as PTR //case kDNSType_NULL not checked (no specified format, so always valid) //case kDNSType_WKS not checked case kDNSType_PTR: len = DomainNameLengthLimit(&rd->u.name, rd->u.data + rdlength); return(len <= MAX_DOMAIN_NAME && rdlength == len); case kDNSType_HINFO: // Same as TXT (roughly) case kDNSType_MINFO: // Same as TXT (roughly) case kDNSType_TXT: if (!rdlength) return(mDNSfalse); // TXT record has to be at least one byte (RFC 1035) { const mDNSu8 *ptr = rd->u.txt.c; const mDNSu8 *end = rd->u.txt.c + rdlength; while (ptr < end) ptr += 1 + ptr[0]; return (ptr == end); } case kDNSType_AAAA: return(rdlength == sizeof(mDNSv6Addr)); case kDNSType_MX: // Must be at least two-byte preference, plus domainname // Call to DomainNameLengthLimit() implicitly enforces both requirements for us len = DomainNameLengthLimit(&rd->u.mx.exchange, rd->u.data + rdlength); return(len <= MAX_DOMAIN_NAME && rdlength == 2+len); case kDNSType_SRV: // Must be at least priority+weight+port, plus domainname // Call to DomainNameLengthLimit() implicitly enforces both requirements for us len = DomainNameLengthLimit(&rd->u.srv.target, rd->u.data + rdlength); return(len <= MAX_DOMAIN_NAME && rdlength == 6+len); //case kDNSType_NSEC not checked default: return(mDNStrue); // Allow all other types without checking } } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNS Message Creation Functions #endif mDNSexport void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags) { h->id = id; h->flags = flags; h->numQuestions = 0; h->numAnswers = 0; h->numAuthorities = 0; h->numAdditionals = 0; } #endif // !STANDALONE mDNSexport const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname) { const mDNSu8 *result = end - *domname - 1; if (*domname == 0) return(mDNSNULL); // There's no point trying to match just the root label // This loop examines each possible starting position in packet, starting end of the packet and working backwards while (result >= base) { // If the length byte and first character of the label match, then check further to see // if this location in the packet will yield a useful name compression pointer. if (result[0] == domname[0] && result[1] == domname[1]) { const mDNSu8 *name = domname; const mDNSu8 *targ = result; while (targ + *name < end) { // First see if this label matches int i; const mDNSu8 *pointertarget; for (i=0; i <= *name; i++) if (targ[i] != name[i]) break; if (i <= *name) break; // If label did not match, bail out targ += 1 + *name; // Else, did match, so advance target pointer name += 1 + *name; // and proceed to check next label if (*name == 0 && *targ == 0) return(result); // If no more labels, we found a match! if (*name == 0) break; // If no more labels to match, we failed, so bail out // The label matched, so now follow the pointer (if appropriate) and then see if the next label matches if (targ[0] < 0x40) continue; // If length value, continue to check next label if (targ[0] < 0xC0) break; // If 40-BF, not valid if (targ+1 >= end) break; // Second byte not present! pointertarget = base + (((mDNSu16)(targ[0] & 0x3F)) << 8) + targ[1]; if (targ < pointertarget) break; // Pointertarget must point *backwards* in the packet if (pointertarget[0] >= 0x40) break; // Pointertarget must point to a valid length byte targ = pointertarget; } } result--; // We failed to match at this search position, so back up the tentative result pointer and try again } return(mDNSNULL); } // domainname is a fully-qualified name (i.e. assumed to be ending in a dot, even if it doesn't) // msg points to the message we're building (pass mDNSNULL if we don't want to use compression pointers) // end points to the end of the message so far // ptr points to where we want to put the name // limit points to one byte past the end of the buffer that we must not overrun // domainname is the name to put mDNSexport mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name) { const mDNSu8 *const base = (const mDNSu8 *)msg; const mDNSu8 * np = name->c; const mDNSu8 *const max = name->c + MAX_DOMAIN_NAME; // Maximum that's valid const mDNSu8 * pointer = mDNSNULL; const mDNSu8 *const searchlimit = ptr; if (!ptr) { LogMsg("putDomainNameAsLabels %##s ptr is null", name->c); return(mDNSNULL); } if (!*np) // If just writing one-byte root label, make sure we have space for that { if (ptr >= limit) return(mDNSNULL); } else // else, loop through writing labels and/or a compression offset { do { if (*np > MAX_DOMAIN_LABEL) { LogMsg("Malformed domain name %##s (label more than 63 bytes)", name->c); return(mDNSNULL); } // This check correctly allows for the final trailing root label: // e.g. // Suppose our domain name is exactly 256 bytes long, including the final trailing root label. // Suppose np is now at name->c[249], and we're about to write our last non-null label ("local"). // We know that max will be at name->c[256] // That means that np + 1 + 5 == max - 1, so we (just) pass the "if" test below, write our // six bytes, then exit the loop, write the final terminating root label, and the domain // name we've written is exactly 256 bytes long, exactly at the correct legal limit. // If the name is one byte longer, then we fail the "if" test below, and correctly bail out. if (np + 1 + *np >= max) { LogMsg("Malformed domain name %##s (more than 256 bytes)", name->c); return(mDNSNULL); } if (base) pointer = FindCompressionPointer(base, searchlimit, np); if (pointer) // Use a compression pointer if we can { const mDNSu16 offset = (mDNSu16)(pointer - base); if (ptr+2 > limit) return(mDNSNULL); // If we don't have two bytes of space left, give up *ptr++ = (mDNSu8)(0xC0 | (offset >> 8)); *ptr++ = (mDNSu8)( offset & 0xFF); return(ptr); } else // Else copy one label and try again { int i; mDNSu8 len = *np++; // If we don't at least have enough space for this label *plus* a terminating zero on the end, give up if (ptr + 1 + len >= limit) return(mDNSNULL); *ptr++ = len; for (i=0; i> 8 ) & 0xFF); ptr[1] = (mDNSu8)((val ) & 0xFF); return ptr + sizeof(mDNSOpaque16); } mDNSlocal mDNSu8 *putVal32(mDNSu8 *ptr, mDNSu32 val) { ptr[0] = (mDNSu8)((val >> 24) & 0xFF); ptr[1] = (mDNSu8)((val >> 16) & 0xFF); ptr[2] = (mDNSu8)((val >> 8) & 0xFF); ptr[3] = (mDNSu8)((val ) & 0xFF); return ptr + sizeof(mDNSu32); } // Copy the RDATA information. The actual in memory storage for the data might be bigger than what the rdlength // says. Hence, the only way to copy out the data from a resource record is to use putRData. // msg points to the message we're building (pass mDNSNULL for "msg" if we don't want to use compression pointers) mDNSexport mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr) { const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data; switch (rr->rrtype) { case kDNSType_A: if (rr->rdlength != 4) { debugf("putRData: Illegal length %d for kDNSType_A", rr->rdlength); return(mDNSNULL); } if (ptr + 4 > limit) return(mDNSNULL); *ptr++ = rdb->ipv4.b[0]; *ptr++ = rdb->ipv4.b[1]; *ptr++ = rdb->ipv4.b[2]; *ptr++ = rdb->ipv4.b[3]; return(ptr); case kDNSType_NS: case kDNSType_CNAME: case kDNSType_PTR: case kDNSType_DNAME: return(putDomainNameAsLabels(msg, ptr, limit, &rdb->name)); case kDNSType_SOA: ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->soa.mname); if (!ptr) return(mDNSNULL); ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->soa.rname); if (!ptr || ptr + 20 > limit) return(mDNSNULL); ptr = putVal32(ptr, rdb->soa.serial); ptr = putVal32(ptr, rdb->soa.refresh); ptr = putVal32(ptr, rdb->soa.retry); ptr = putVal32(ptr, rdb->soa.expire); ptr = putVal32(ptr, rdb->soa.min); return(ptr); case kDNSType_NULL: case kDNSType_HINFO: case kDNSType_TSIG: case kDNSType_TXT: case kDNSType_X25: case kDNSType_ISDN: case kDNSType_LOC: case kDNSType_DHCID: if (ptr + rr->rdlength > limit) return(mDNSNULL); mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength); return(ptr + rr->rdlength); case kDNSType_MX: case kDNSType_AFSDB: case kDNSType_RT: case kDNSType_KX: if (ptr + 3 > limit) return(mDNSNULL); ptr = putVal16(ptr, rdb->mx.preference); return(putDomainNameAsLabels(msg, ptr, limit, &rdb->mx.exchange)); case kDNSType_RP: ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->rp.mbox); if (!ptr) return(mDNSNULL); ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->rp.txt); return(ptr); case kDNSType_PX: if (ptr + 5 > limit) return(mDNSNULL); ptr = putVal16(ptr, rdb->px.preference); ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->px.map822); if (!ptr) return(mDNSNULL); ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->px.mapx400); return(ptr); case kDNSType_AAAA: if (rr->rdlength != sizeof(rdb->ipv6)) { debugf("putRData: Illegal length %d for kDNSType_AAAA", rr->rdlength); return(mDNSNULL); } if (ptr + sizeof(rdb->ipv6) > limit) return(mDNSNULL); mDNSPlatformMemCopy(ptr, &rdb->ipv6, sizeof(rdb->ipv6)); return(ptr + sizeof(rdb->ipv6)); case kDNSType_SRV: if (ptr + 7 > limit) return(mDNSNULL); *ptr++ = (mDNSu8)(rdb->srv.priority >> 8); *ptr++ = (mDNSu8)(rdb->srv.priority & 0xFF); *ptr++ = (mDNSu8)(rdb->srv.weight >> 8); *ptr++ = (mDNSu8)(rdb->srv.weight & 0xFF); *ptr++ = rdb->srv.port.b[0]; *ptr++ = rdb->srv.port.b[1]; return(putDomainNameAsLabels(msg, ptr, limit, &rdb->srv.target)); case kDNSType_OPT: { int len = 0; const rdataOPT *opt; const rdataOPT *const end = (const rdataOPT *)&rr->rdata->u.data[rr->rdlength]; for (opt = &rr->rdata->u.opt[0]; opt < end; opt++) len += DNSOpt_Data_Space(opt); if (ptr + len > limit) { LogMsg("ERROR: putOptRData - out of space"); return mDNSNULL; } for (opt = &rr->rdata->u.opt[0]; opt < end; opt++) { const int space = DNSOpt_Data_Space(opt); ptr = putVal16(ptr, opt->opt); ptr = putVal16(ptr, (mDNSu16)space - 4); switch (opt->opt) { case kDNSOpt_LLQ: ptr = putVal16(ptr, opt->u.llq.vers); ptr = putVal16(ptr, opt->u.llq.llqOp); ptr = putVal16(ptr, opt->u.llq.err); mDNSPlatformMemCopy(ptr, opt->u.llq.id.b, 8); // 8-byte id ptr += 8; ptr = putVal32(ptr, opt->u.llq.llqlease); break; case kDNSOpt_Lease: ptr = putVal32(ptr, opt->u.updatelease); break; case kDNSOpt_Owner: *ptr++ = opt->u.owner.vers; *ptr++ = opt->u.owner.seq; mDNSPlatformMemCopy(ptr, opt->u.owner.HMAC.b, 6); // 6-byte Host identifier ptr += 6; if (space >= DNSOpt_OwnerData_ID_Wake_Space) { mDNSPlatformMemCopy(ptr, opt->u.owner.IMAC.b, 6); // 6-byte interface MAC ptr += 6; if (space > DNSOpt_OwnerData_ID_Wake_Space) { mDNSPlatformMemCopy(ptr, opt->u.owner.password.b, space - DNSOpt_OwnerData_ID_Wake_Space); ptr += space - DNSOpt_OwnerData_ID_Wake_Space; } } break; case kDNSOpt_Trace: *ptr++ = opt->u.tracer.platf; ptr = putVal32(ptr, opt->u.tracer.mDNSv); break; } } return ptr; } case kDNSType_NSEC: { // For NSEC records, rdlength represents the exact number of bytes // of in memory storage. mDNSu8 *nsec = (mDNSu8 *)rdb->data; domainname *name = (domainname *)nsec; const int dlen = DomainNameLength(name); nsec += dlen; // This function is called when we are sending a NSEC record as part of mDNS, // or to copy the data to any other buffer needed which could be a mDNS or uDNS // NSEC record. The only time compression is used that when we are sending it // in mDNS (indicated by non-NULL "msg") and hence we handle mDNS case // separately. if (!UNICAST_NSEC(rr)) { mDNSu8 *save = ptr; int i, j, wlen; wlen = *(nsec + 1); nsec += 2; // Skip the window number and len // For our simplified use of NSEC synthetic records: // // nextname is always the record's own name, // the block number is always 0, // the count byte is a value in the range 1-32, // followed by the 1-32 data bytes // // Note: When we send the NSEC record in mDNS, the window size is set to 32. // We need to find out what the last non-NULL byte is. If we are copying out // from an RDATA, we have the right length. As we need to handle both the case, // we loop to find the right value instead of blindly using len to copy. for (i=wlen; i>0; i--) if (nsec[i-1]) break; ptr = putDomainNameAsLabels(msg, ptr, limit, rr->name); if (!ptr) { LogInfo("putRData: Can't put name, Length %d, record %##s", limit - save, rr->name->c); return(mDNSNULL); } if (i) // Only put a block if at least one type exists for this name { if (ptr + 2 + i > limit) { LogInfo("putRData: Can't put window, Length %d, i %d, record %##s", limit - ptr, i, rr->name->c); return(mDNSNULL); } *ptr++ = 0; *ptr++ = (mDNSu8)i; for (j=0; jrdlength - dlen; // Sanity check whether the bitmap is good while (len) { if (len < 3) { LogMsg("putRData: invalid length %d", len); return mDNSNULL; } win = *nsec++; wlen = *nsec++; len -= 2; if (len < wlen || wlen < 1 || wlen > 32) { LogMsg("putRData: invalid window length %d", wlen); return mDNSNULL; } if (win < 0 || win >= 256) { LogMsg("putRData: invalid window %d", win); return mDNSNULL; } nsec += wlen; len -= wlen; } if (ptr + rr->rdlength > limit) { LogMsg("putRData: NSEC rdlength beyond limit %##s (%s), ptr %p, rdlength %d, limit %p", rr->name->c, DNSTypeName(rr->rrtype), ptr, rr->rdlength, limit); return(mDNSNULL);} // No compression allowed for "nxt", just copy the data. mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength); return(ptr + rr->rdlength); } } default: debugf("putRData: Warning! Writing unknown resource type %d as raw data", rr->rrtype); if (ptr + rr->rdlength > limit) return(mDNSNULL); mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength); return(ptr + rr->rdlength); } } #define IsUnicastUpdate(X) (!mDNSOpaque16IsZero((X)->h.id) && ((X)->h.flags.b[0] & kDNSFlag0_OP_Mask) == kDNSFlag0_OP_Update) mDNSexport mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, const ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit) { mDNSu8 *endofrdata; mDNSu16 actualLength; // When sending SRV to conventional DNS server (i.e. in DNS update requests) we should not do name compression on the rdata (RFC 2782) const DNSMessage *const rdatacompressionbase = (IsUnicastUpdate(msg) && rr->rrtype == kDNSType_SRV) ? mDNSNULL : msg; if (rr->RecordType == kDNSRecordTypeUnregistered) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "Attempt to put kDNSRecordTypeUnregistered " PRI_DM_NAME " (" PUB_S ")", DM_NAME_PARAM(rr->name), DNSTypeName(rr->rrtype)); return(ptr); } if (!ptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "Pointer to message is NULL while filling resource record " PRI_DM_NAME " (" PUB_S ")", DM_NAME_PARAM(rr->name), DNSTypeName(rr->rrtype)); return(mDNSNULL); } ptr = putDomainNameAsLabels(msg, ptr, limit, rr->name); // If we're out-of-space, return mDNSNULL if (!ptr || ptr + 10 >= limit) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "Can't put more names into current message, will possibly put it into the next message - " "name: " PRI_DM_NAME " (" PUB_S "), remaining space: %ld", DM_NAME_PARAM(rr->name), DNSTypeName(rr->rrtype), (long)(limit - ptr)); return(mDNSNULL); } ptr[0] = (mDNSu8)(rr->rrtype >> 8); ptr[1] = (mDNSu8)(rr->rrtype & 0xFF); ptr[2] = (mDNSu8)(rr->rrclass >> 8); ptr[3] = (mDNSu8)(rr->rrclass & 0xFF); ptr[4] = (mDNSu8)((ttl >> 24) & 0xFF); ptr[5] = (mDNSu8)((ttl >> 16) & 0xFF); ptr[6] = (mDNSu8)((ttl >> 8) & 0xFF); ptr[7] = (mDNSu8)( ttl & 0xFF); // ptr[8] and ptr[9] filled in *after* we find out how much space the rdata takes endofrdata = putRData(rdatacompressionbase, ptr+10, limit, rr); if (!endofrdata) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "Can't put more rdata into current message, will possibly put it into the next message - " "name: " PRI_DM_NAME " (" PUB_S "), remaining space: %ld", DM_NAME_PARAM(rr->name), DNSTypeName(rr->rrtype), (long)(limit - ptr - 10)); return(mDNSNULL); } // Go back and fill in the actual number of data bytes we wrote // (actualLength can be less than rdlength when domain name compression is used) actualLength = (mDNSu16)(endofrdata - ptr - 10); ptr[8] = (mDNSu8)(actualLength >> 8); ptr[9] = (mDNSu8)(actualLength & 0xFF); if (count) { (*count)++; } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "No target count to update for " PRI_DM_NAME " (" PUB_S ")", DM_NAME_PARAM(rr->name), DNSTypeName(rr->rrtype)); } return(endofrdata); } mDNSlocal mDNSu8 *putEmptyResourceRecord(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, mDNSu16 *count, const AuthRecord *rr) { ptr = putDomainNameAsLabels(msg, ptr, limit, rr->resrec.name); if (!ptr || ptr + 10 > limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL ptr[0] = (mDNSu8)(rr->resrec.rrtype >> 8); // Put type ptr[1] = (mDNSu8)(rr->resrec.rrtype & 0xFF); ptr[2] = (mDNSu8)(rr->resrec.rrclass >> 8); // Put class ptr[3] = (mDNSu8)(rr->resrec.rrclass & 0xFF); ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // TTL is zero ptr[8] = ptr[9] = 0; // RDATA length is zero (*count)++; return(ptr + 10); } mDNSexport mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass) { ptr = putDomainNameAsLabels(msg, ptr, limit, name); if (!ptr || ptr+4 >= limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL ptr[0] = (mDNSu8)(rrtype >> 8); ptr[1] = (mDNSu8)(rrtype & 0xFF); ptr[2] = (mDNSu8)(rrclass >> 8); ptr[3] = (mDNSu8)(rrclass & 0xFF); msg->h.numQuestions++; return(ptr+4); } // for dynamic updates mDNSexport mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass) { ptr = putDomainNameAsLabels(msg, ptr, limit, zone); if (!ptr || ptr + 4 > limit) return mDNSNULL; // If we're out-of-space, return NULL *ptr++ = (mDNSu8)(kDNSType_SOA >> 8); *ptr++ = (mDNSu8)(kDNSType_SOA & 0xFF); *ptr++ = zoneClass.b[0]; *ptr++ = zoneClass.b[1]; msg->h.mDNS_numZones++; return ptr; } // for dynamic updates mDNSexport mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *const msg, mDNSu8 *const ptr, mDNSu8 *const end) { AuthRecord prereq; mDNS_SetupResourceRecord(&prereq, mDNSNULL, mDNSInterface_Any, kDNSQType_ANY, kStandardTTL, 0, AuthRecordAny, mDNSNULL, mDNSNULL); AssignDomainName(&prereq.namestorage, name); prereq.resrec.rrtype = kDNSQType_ANY; prereq.resrec.rrclass = kDNSClass_NONE; return putEmptyResourceRecord(msg, ptr, end, &msg->h.mDNS_numPrereqs, &prereq); } // for dynamic updates mDNSexport mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr) { // deletion: specify record w/ TTL 0, class NONE const mDNSu16 origclass = rr->rrclass; rr->rrclass = kDNSClass_NONE; ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.mDNS_numUpdates, rr, 0); rr->rrclass = origclass; return ptr; } // for dynamic updates mDNSexport mDNSu8 *putDeletionRecordWithLimit(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr, mDNSu8 *limit) { // deletion: specify record w/ TTL 0, class NONE const mDNSu16 origclass = rr->rrclass; rr->rrclass = kDNSClass_NONE; ptr = PutResourceRecordTTLWithLimit(msg, ptr, &msg->h.mDNS_numUpdates, rr, 0, limit); rr->rrclass = origclass; return ptr; } mDNSexport mDNSu8 *putDeleteRRSetWithLimit(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype, mDNSu8 *limit) { mDNSu16 class = kDNSQClass_ANY; ptr = putDomainNameAsLabels(msg, ptr, limit, name); if (!ptr || ptr + 10 >= limit) return mDNSNULL; // If we're out-of-space, return mDNSNULL ptr[0] = (mDNSu8)(rrtype >> 8); ptr[1] = (mDNSu8)(rrtype & 0xFF); ptr[2] = (mDNSu8)(class >> 8); ptr[3] = (mDNSu8)(class & 0xFF); ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // zero ttl ptr[8] = ptr[9] = 0; // zero rdlength/rdata msg->h.mDNS_numUpdates++; return ptr + 10; } // for dynamic updates mDNSexport mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name) { const mDNSu8 *limit = msg->data + AbsoluteMaxDNSMessageData; mDNSu16 class = kDNSQClass_ANY; mDNSu16 rrtype = kDNSQType_ANY; ptr = putDomainNameAsLabels(msg, ptr, limit, name); if (!ptr || ptr + 10 >= limit) return mDNSNULL; // If we're out-of-space, return mDNSNULL ptr[0] = (mDNSu8)(rrtype >> 8); ptr[1] = (mDNSu8)(rrtype & 0xFF); ptr[2] = (mDNSu8)(class >> 8); ptr[3] = (mDNSu8)(class & 0xFF); ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // zero ttl ptr[8] = ptr[9] = 0; // zero rdlength/rdata msg->h.mDNS_numUpdates++; return ptr + 10; } // for dynamic updates mDNSexport mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease) { AuthRecord rr; mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); rr.resrec.rrclass = NormalMaxDNSMessageData; rr.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record rr.resrec.rdestimate = sizeof(rdataOPT); rr.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease; rr.resrec.rdata->u.opt[0].u.updatelease = lease; ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.numAdditionals, &rr.resrec, 0); if (!ptr) { LogMsg("ERROR: putUpdateLease - PutResourceRecordTTL"); return mDNSNULL; } return ptr; } // for dynamic updates mDNSexport mDNSu8 *putUpdateLeaseWithLimit(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease, mDNSu8 *limit) { AuthRecord rr; mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); rr.resrec.rrclass = NormalMaxDNSMessageData; rr.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record rr.resrec.rdestimate = sizeof(rdataOPT); rr.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease; rr.resrec.rdata->u.opt[0].u.updatelease = lease; ptr = PutResourceRecordTTLWithLimit(msg, ptr, &msg->h.numAdditionals, &rr.resrec, 0, limit); if (!ptr) { LogMsg("ERROR: putUpdateLeaseWithLimit - PutResourceRecordTTLWithLimit"); return mDNSNULL; } return ptr; } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNS Message Parsing Functions #endif mDNSexport mDNSu32 DomainNameHashValue(const domainname *const name) { mDNSu32 sum = 0; const mDNSu8 *c; for (c = name->c; c[0] != 0 && c[1] != 0; c += 2) { sum += ((mDNSIsUpperCase(c[0]) ? c[0] + 'a' - 'A' : c[0]) << 8) | (mDNSIsUpperCase(c[1]) ? c[1] + 'a' - 'A' : c[1]); sum = (sum<<3) | (sum>>29); } if (c[0]) sum += ((mDNSIsUpperCase(c[0]) ? c[0] + 'a' - 'A' : c[0]) << 8); return(sum); } mDNSexport void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength) { domainname *target; if (NewRData) { rr->rdata = NewRData; rr->rdlength = rdlength; } // Must not try to get target pointer until after updating rr->rdata target = GetRRDomainNameTarget(rr); rr->rdlength = GetRDLength(rr, mDNSfalse); rr->rdestimate = GetRDLength(rr, mDNStrue); rr->rdatahash = target ? DomainNameHashValue(target) : RDataHashValue(rr); } mDNSexport const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end) { mDNSu16 total = 0; if (ptr < (mDNSu8*)msg || ptr >= end) { debugf("skipDomainName: Illegal ptr not within packet boundaries"); return(mDNSNULL); } while (1) // Read sequence of labels { const mDNSu8 len = *ptr++; // Read length of this label if (len == 0) return(ptr); // If length is zero, that means this name is complete switch (len & 0xC0) { case 0x00: if (ptr + len >= end) // Remember: expect at least one more byte for the root label { debugf("skipDomainName: Malformed domain name (overruns packet end)"); return(mDNSNULL); } if (total + 1 + len >= MAX_DOMAIN_NAME) // Remember: expect at least one more byte for the root label { debugf("skipDomainName: Malformed domain name (more than 256 characters)"); return(mDNSNULL); } ptr += len; total += 1 + len; break; case 0x40: debugf("skipDomainName: Extended EDNS0 label types 0x%X not supported", len); return(mDNSNULL); case 0x80: debugf("skipDomainName: Illegal label length 0x%X", len); return(mDNSNULL); case 0xC0: return(ptr+1); } } } // Routine to fetch an FQDN from the DNS message, following compression pointers if necessary. mDNSexport const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, domainname *const name) { const mDNSu8 *nextbyte = mDNSNULL; // Record where we got to before we started following pointers mDNSu8 *np = name->c; // Name pointer const mDNSu8 *const limit = np + MAX_DOMAIN_NAME; // Limit so we don't overrun buffer if (ptr < (mDNSu8*)msg || ptr >= end) { debugf("getDomainName: Illegal ptr not within packet boundaries"); return(mDNSNULL); } *np = 0; // Tentatively place the root label here (may be overwritten if we have more labels) while (1) // Read sequence of labels { int i; mDNSu16 offset; const mDNSu8 len = *ptr++; // Read length of this label if (len == 0) break; // If length is zero, that means this name is complete switch (len & 0xC0) { case 0x00: if (ptr + len >= end) // Remember: expect at least one more byte for the root label { debugf("getDomainName: Malformed domain name (overruns packet end)"); return(mDNSNULL); } if (np + 1 + len >= limit) // Remember: expect at least one more byte for the root label { debugf("getDomainName: Malformed domain name (more than 256 characters)"); return(mDNSNULL); } *np++ = len; for (i=0; ic); return(mDNSNULL); case 0x80: debugf("getDomainName: Illegal label length 0x%X in domain name %##s", len, name->c); return(mDNSNULL); case 0xC0: if (ptr >= end) { debugf("getDomainName: Malformed compression label (overruns packet end)"); return(mDNSNULL); } offset = (mDNSu16)((((mDNSu16)(len & 0x3F)) << 8) | *ptr++); if (!nextbyte) nextbyte = ptr; // Record where we got to before we started following pointers ptr = (mDNSu8 *)msg + offset; if (ptr < (mDNSu8*)msg || ptr >= end) { debugf("getDomainName: Illegal compression pointer not within packet boundaries"); return(mDNSNULL); } if (*ptr & 0xC0) { debugf("getDomainName: Compression pointer must point to real label"); return(mDNSNULL); } break; } } if (nextbyte) return(nextbyte); else return(ptr); } mDNSexport const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end) { mDNSu16 pktrdlength; ptr = skipDomainName(msg, ptr, end); if (!ptr) { debugf("skipResourceRecord: Malformed RR name"); return(mDNSNULL); } if (ptr + 10 > end) { debugf("skipResourceRecord: Malformed RR -- no type/class/ttl/len!"); return(mDNSNULL); } pktrdlength = (mDNSu16)((mDNSu16)ptr[8] << 8 | ptr[9]); ptr += 10; if (ptr + pktrdlength > end) { debugf("skipResourceRecord: RDATA exceeds end of packet"); return(mDNSNULL); } return(ptr + pktrdlength); } // Sanity check whether the NSEC/NSEC3 bitmap is good mDNSlocal mDNSu8 *SanityCheckBitMap(const mDNSu8 *bmap, const mDNSu8 *end, int len) { int win, wlen; while (bmap < end) { if (len < 3) { LogInfo("SanityCheckBitMap: invalid length %d", len); return mDNSNULL; } win = *bmap++; wlen = *bmap++; len -= 2; if (len < wlen || wlen < 1 || wlen > 32) { LogInfo("SanityCheckBitMap: invalid window length %d", wlen); return mDNSNULL; } if (win < 0 || win >= 256) { LogInfo("SanityCheckBitMap: invalid window %d", win); return mDNSNULL; } bmap += wlen; len -= wlen; } return (mDNSu8 *)bmap; } mDNSlocal mDNSBool AssignDomainNameWithLimit(domainname *const dst, const domainname *src, const mDNSu8 *const end) { const mDNSu32 len = DomainNameLengthLimit(src, end); if ((len >= 1) && (len <= MAX_DOMAIN_NAME)) { mDNSPlatformMemCopy(dst->c, src->c, len); return mDNStrue; } else { dst->c[0] = 0; return mDNSfalse; } } // This function is called with "msg" when we receive a DNS message and needs to parse a single resource record // pointed to by "ptr". Some resource records like SOA, SRV are converted to host order and also expanded // (domainnames are expanded to 256 bytes) when stored in memory. // // This function can also be called with "NULL" msg to parse a single resource record pointed to by ptr. // The caller can do this only if the names in the resource records are not compressed and validity of the // resource record has already been done before. mDNSexport mDNSBool SetRData(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *end, ResourceRecord *const rr, const mDNSu16 rdlength) { RDataBody2 *const rdb = (RDataBody2 *)&rr->rdata->u; switch (rr->rrtype) { case kDNSType_A: if (rdlength != sizeof(mDNSv4Addr)) goto fail; rdb->ipv4.b[0] = ptr[0]; rdb->ipv4.b[1] = ptr[1]; rdb->ipv4.b[2] = ptr[2]; rdb->ipv4.b[3] = ptr[3]; break; case kDNSType_NS: case kDNSType_MD: case kDNSType_MF: case kDNSType_CNAME: case kDNSType_MB: case kDNSType_MG: case kDNSType_MR: case kDNSType_PTR: case kDNSType_NSAP_PTR: case kDNSType_DNAME: if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->name); } else { if (!AssignDomainNameWithLimit(&rdb->name, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->name); } if (ptr != end) { debugf("SetRData: Malformed CNAME/PTR RDATA name"); goto fail; } break; case kDNSType_SOA: if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->soa.mname); } else { if (!AssignDomainNameWithLimit(&rdb->soa.mname, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->soa.mname); } if (!ptr) { debugf("SetRData: Malformed SOA RDATA mname"); goto fail; } if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->soa.rname); } else { if (!AssignDomainNameWithLimit(&rdb->soa.rname, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->soa.rname); } if (!ptr) { debugf("SetRData: Malformed SOA RDATA rname"); goto fail; } if (ptr + 0x14 != end) { debugf("SetRData: Malformed SOA RDATA"); goto fail; } rdb->soa.serial = (mDNSs32) ((mDNSs32)ptr[0x00] << 24 | (mDNSs32)ptr[0x01] << 16 | (mDNSs32)ptr[0x02] << 8 | ptr[0x03]); rdb->soa.refresh = (mDNSu32) ((mDNSu32)ptr[0x04] << 24 | (mDNSu32)ptr[0x05] << 16 | (mDNSu32)ptr[0x06] << 8 | ptr[0x07]); rdb->soa.retry = (mDNSu32) ((mDNSu32)ptr[0x08] << 24 | (mDNSu32)ptr[0x09] << 16 | (mDNSu32)ptr[0x0A] << 8 | ptr[0x0B]); rdb->soa.expire = (mDNSu32) ((mDNSu32)ptr[0x0C] << 24 | (mDNSu32)ptr[0x0D] << 16 | (mDNSu32)ptr[0x0E] << 8 | ptr[0x0F]); rdb->soa.min = (mDNSu32) ((mDNSu32)ptr[0x10] << 24 | (mDNSu32)ptr[0x11] << 16 | (mDNSu32)ptr[0x12] << 8 | ptr[0x13]); break; case kDNSType_HINFO: // See https://tools.ietf.org/html/rfc1035#section-3.3.2 for HINFO RDATA format. { // HINFO should contain RDATA. if (end <= ptr || rdlength != (mDNSu32)(end - ptr)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "SetRData: Malformed HINFO RDATA - invalid RDATA length: %u", rdlength); goto fail; } const mDNSu8 *currentPtr = ptr; // CPU character string length should be less than the RDATA length. mDNSu32 cpuCharacterStrLength = currentPtr[0]; if (1 + cpuCharacterStrLength >= (mDNSu32)(end - currentPtr)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "SetRData: Malformed HINFO RDATA - CPU character string goes out of boundary"); goto fail; } currentPtr += 1 + cpuCharacterStrLength; // OS character string should end at the RDATA ending. mDNSu32 osCharacterStrLength = currentPtr[0]; if (1 + osCharacterStrLength != (mDNSu32)(end - currentPtr)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "SetRData: Malformed HINFO RDATA - OS character string does not end at the RDATA ending"); goto fail; } // Copy the validated RDATA. rr->rdlength = rdlength; mDNSPlatformMemCopy(rdb->data, ptr, rdlength); break; } case kDNSType_NULL: case kDNSType_TXT: case kDNSType_X25: case kDNSType_ISDN: case kDNSType_LOC: case kDNSType_DHCID: case kDNSType_SVCB: case kDNSType_HTTPS: rr->rdlength = rdlength; mDNSPlatformMemCopy(rdb->data, ptr, rdlength); break; case kDNSType_MX: case kDNSType_AFSDB: case kDNSType_RT: case kDNSType_KX: // Preference + domainname if (rdlength < 3) goto fail; rdb->mx.preference = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); ptr += 2; if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->mx.exchange); } else { if (!AssignDomainNameWithLimit(&rdb->mx.exchange, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->mx.exchange); } if (ptr != end) { debugf("SetRData: Malformed MX name"); goto fail; } break; case kDNSType_MINFO: case kDNSType_RP: // Domainname + domainname if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->rp.mbox); } else { if (!AssignDomainNameWithLimit(&rdb->rp.mbox, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->rp.mbox); } if (!ptr) { debugf("SetRData: Malformed RP mbox"); goto fail; } if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->rp.txt); } else { if (!AssignDomainNameWithLimit(&rdb->rp.txt, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->rp.txt); } if (ptr != end) { debugf("SetRData: Malformed RP txt"); goto fail; } break; case kDNSType_PX: // Preference + domainname + domainname if (rdlength < 4) goto fail; rdb->px.preference = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); ptr += 2; if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->px.map822); } else { if (!AssignDomainNameWithLimit(&rdb->px.map822, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->px.map822); } if (!ptr) { debugf("SetRData: Malformed PX map822"); goto fail; } if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->px.mapx400); } else { if (!AssignDomainNameWithLimit(&rdb->px.mapx400, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->px.mapx400); } if (ptr != end) { debugf("SetRData: Malformed PX mapx400"); goto fail; } break; case kDNSType_AAAA: if (rdlength != sizeof(mDNSv6Addr)) goto fail; mDNSPlatformMemCopy(&rdb->ipv6, ptr, sizeof(rdb->ipv6)); break; case kDNSType_SRV: // Priority + weight + port + domainname if (rdlength < 7) goto fail; rdb->srv.priority = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); rdb->srv.weight = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); rdb->srv.port.b[0] = ptr[4]; rdb->srv.port.b[1] = ptr[5]; ptr += 6; if (msg) { ptr = getDomainName(msg, ptr, end, &rdb->srv.target); } else { if (!AssignDomainNameWithLimit(&rdb->srv.target, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&rdb->srv.target); } if (ptr != end) { debugf("SetRData: Malformed SRV RDATA name"); goto fail; } break; case kDNSType_NAPTR: { int savelen, len; domainname name; const mDNSu8 *orig = ptr; // Make sure the data is parseable and within the limits. // // Fixed length: Order, preference (4 bytes) // Variable length: flags, service, regexp, domainname if (rdlength < 8) goto fail; // Order, preference. ptr += 4; // Parse flags, Service and Regexp // length in the first byte does not include the length byte itself len = *ptr + 1; ptr += len; if (ptr >= end) { LogInfo("SetRData: Malformed NAPTR flags"); goto fail; } // Service len = *ptr + 1; ptr += len; if (ptr >= end) { LogInfo("SetRData: Malformed NAPTR service"); goto fail; } // Regexp len = *ptr + 1; ptr += len; if (ptr >= end) { LogInfo("SetRData: Malformed NAPTR regexp"); goto fail; } savelen = (int)(ptr - orig); // RFC 2915 states that name compression is not allowed for this field. But RFC 3597 // states that for NAPTR we should decompress. We make sure that we store the full // name rather than the compressed name if (msg) { ptr = getDomainName(msg, ptr, end, &name); } else { if (!AssignDomainNameWithLimit(&name, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&name); } if (ptr != end) { LogInfo("SetRData: Malformed NAPTR RDATA name"); goto fail; } rr->rdlength = savelen + DomainNameLength(&name); // The uncompressed size should not exceed the limits if (rr->rdlength > MaximumRDSize) { LogInfo("SetRData: Malformed NAPTR rdlength %d, rr->rdlength %d, " "bmaplen %d, name %##s", rdlength, rr->rdlength, name.c); goto fail; } mDNSPlatformMemCopy(rdb->data, orig, savelen); AssignDomainName((domainname *)(rdb->data + savelen), &name); break; } case kDNSType_OPT: { const mDNSu8 * const dataend = &rr->rdata->u.data[rr->rdata->MaxRDLength]; rdataOPT *opt = rr->rdata->u.opt; rr->rdlength = 0; while ((ptr < end) && ((dataend - ((const mDNSu8 *)opt)) >= ((mDNSs32)sizeof(*opt)))) { const rdataOPT *const currentopt = opt; if (ptr + 4 > end) { LogInfo("SetRData: OPT RDATA ptr + 4 > end"); goto fail; } opt->opt = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); opt->optlen = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); ptr += 4; if (ptr + opt->optlen > end) { LogInfo("SetRData: ptr + opt->optlen > end"); goto fail; } switch (opt->opt) { case kDNSOpt_LLQ: if (opt->optlen == DNSOpt_LLQData_Space - 4) { opt->u.llq.vers = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); opt->u.llq.llqOp = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); opt->u.llq.err = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]); mDNSPlatformMemCopy(opt->u.llq.id.b, ptr+6, 8); opt->u.llq.llqlease = (mDNSu32) ((mDNSu32)ptr[14] << 24 | (mDNSu32)ptr[15] << 16 | (mDNSu32)ptr[16] << 8 | ptr[17]); if (opt->u.llq.llqlease > 0x70000000UL / mDNSPlatformOneSecond) opt->u.llq.llqlease = 0x70000000UL / mDNSPlatformOneSecond; opt++; } break; case kDNSOpt_Lease: if (opt->optlen == DNSOpt_LeaseData_Space - 4) { opt->u.updatelease = (mDNSu32) ((mDNSu32)ptr[0] << 24 | (mDNSu32)ptr[1] << 16 | (mDNSu32)ptr[2] << 8 | ptr[3]); if (opt->u.updatelease > 0x70000000UL / mDNSPlatformOneSecond) opt->u.updatelease = 0x70000000UL / mDNSPlatformOneSecond; opt++; } break; case kDNSOpt_Owner: if (ValidOwnerLength(opt->optlen)) { opt->u.owner.vers = ptr[0]; opt->u.owner.seq = ptr[1]; mDNSPlatformMemCopy(opt->u.owner.HMAC.b, ptr+2, 6); // 6-byte MAC address mDNSPlatformMemCopy(opt->u.owner.IMAC.b, ptr+2, 6); // 6-byte MAC address opt->u.owner.password = zeroEthAddr; if (opt->optlen >= DNSOpt_OwnerData_ID_Wake_Space-4) { mDNSPlatformMemCopy(opt->u.owner.IMAC.b, ptr+8, 6); // 6-byte MAC address // This mDNSPlatformMemCopy is safe because the ValidOwnerLength(opt->optlen) check above // ensures that opt->optlen is no more than DNSOpt_OwnerData_ID_Wake_PW6_Space - 4 if (opt->optlen > DNSOpt_OwnerData_ID_Wake_Space-4) mDNSPlatformMemCopy(opt->u.owner.password.b, ptr+14, opt->optlen - (DNSOpt_OwnerData_ID_Wake_Space-4)); } opt++; } break; case kDNSOpt_Trace: if (opt->optlen == DNSOpt_TraceData_Space - 4) { opt->u.tracer.platf = ptr[0]; opt->u.tracer.mDNSv = (mDNSu32) ((mDNSu32)ptr[1] << 24 | (mDNSu32)ptr[2] << 16 | (mDNSu32)ptr[3] << 8 | ptr[4]); opt++; } else { opt->u.tracer.platf = 0xFF; opt->u.tracer.mDNSv = 0xFFFFFFFF; opt++; } break; } ptr += currentopt->optlen; } rr->rdlength = (mDNSu16)((mDNSu8*)opt - rr->rdata->u.data); if (ptr != end) { LogInfo("SetRData: Malformed OptRdata"); goto fail; } break; } case kDNSType_NSEC: { domainname name; int len = rdlength; int bmaplen, dlen; const mDNSu8 *orig = ptr; const mDNSu8 *bmap; if (msg) { ptr = getDomainName(msg, ptr, end, &name); } else { if (!AssignDomainNameWithLimit(&name, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&name); } if (!ptr) { LogInfo("SetRData: Malformed NSEC nextname"); goto fail; } dlen = DomainNameLength(&name); // Multicast NSECs use name compression for this field unlike the unicast case which // does not use compression. And multicast case always succeeds in compression. So, // the rdlength includes only the compressed space in that case. So, can't // use the DomainNameLength of name to reduce the length here. len -= (ptr - orig); bmaplen = len; // Save the length of the bitmap bmap = ptr; ptr = SanityCheckBitMap(bmap, end, len); if (!ptr) goto fail; if (ptr != end) { LogInfo("SetRData: Malformed NSEC length not right"); goto fail; } // Initialize the right length here. When we call SetNewRData below which in turn calls // GetRDLength and for NSEC case, it assumes that rdlength is intitialized rr->rdlength = DomainNameLength(&name) + bmaplen; // Do we have space after the name expansion ? if (rr->rdlength > MaximumRDSize) { LogInfo("SetRData: Malformed NSEC rdlength %d, rr->rdlength %d, " "bmaplen %d, name %##s", rdlength, rr->rdlength, name.c); goto fail; } AssignDomainName((domainname *)rdb->data, &name); mDNSPlatformMemCopy(rdb->data + dlen, bmap, bmaplen); break; } case kDNSType_TKEY: case kDNSType_TSIG: { domainname name; int dlen, rlen; // The name should not be compressed. But we take the conservative approach // and uncompress the name before we store it. if (msg) { ptr = getDomainName(msg, ptr, end, &name); } else { if (!AssignDomainNameWithLimit(&name, (domainname *)ptr, end)) { goto fail; } ptr += DomainNameLength(&name); } if (!ptr || ptr >= end) { LogInfo("SetRData: Malformed name for TSIG/TKEY type %d", rr->rrtype); goto fail; } dlen = DomainNameLength(&name); rlen = (int)(end - ptr); rr->rdlength = dlen + rlen; if (rr->rdlength > MaximumRDSize) { LogInfo("SetRData: Malformed TSIG/TKEY rdlength %d, rr->rdlength %d, " "bmaplen %d, name %##s", rdlength, rr->rdlength, name.c); goto fail; } AssignDomainName((domainname *)rdb->data, &name); mDNSPlatformMemCopy(rdb->data + dlen, ptr, rlen); break; } default: debugf("SetRData: Warning! Reading resource type %d (%s) as opaque data", rr->rrtype, DNSTypeName(rr->rrtype)); // Note: Just because we don't understand the record type, that doesn't // mean we fail. The DNS protocol specifies rdlength, so we can // safely skip over unknown records and ignore them. // We also grab a binary copy of the rdata anyway, since the caller // might know how to interpret it even if we don't. rr->rdlength = rdlength; mDNSPlatformMemCopy(rdb->data, ptr, rdlength); break; } return mDNStrue; fail: return mDNSfalse; } mDNSexport const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr) { CacheRecord *const rr = &largecr->r; mDNSu16 pktrdlength; mDNSu32 maxttl = (!InterfaceID) ? mDNSMaximumUnicastTTLSeconds : mDNSMaximumMulticastTTLSeconds; if (largecr == &m->rec && m->rec.r.resrec.RecordType) LogFatalError("GetLargeResourceRecord: m->rec appears to be already in use for %s", CRDisplayString(m, &m->rec.r)); rr->next = mDNSNULL; rr->resrec.name = &largecr->namestorage; rr->NextInKAList = mDNSNULL; rr->TimeRcvd = m ? m->timenow : 0; rr->DelayDelivery = 0; rr->NextRequiredQuery = m ? m->timenow : 0; // Will be updated to the real value when we call SetNextCacheCheckTimeForRecord() #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) rr->LastCachedAnswerTime = 0; #endif rr->CRActiveQuestion = mDNSNULL; rr->UnansweredQueries = 0; rr->LastUnansweredTime= 0; rr->NextInCFList = mDNSNULL; rr->resrec.InterfaceID = InterfaceID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_forget(&rr->resrec.dnsservice); #else rr->resrec.rDNSServer = mDNSNULL; #endif ptr = getDomainName(msg, ptr, end, &largecr->namestorage); // Will bail out correctly if ptr is NULL if (!ptr) { debugf("GetLargeResourceRecord: Malformed RR name"); return(mDNSNULL); } rr->resrec.namehash = DomainNameHashValue(rr->resrec.name); if (ptr + 10 > end) { debugf("GetLargeResourceRecord: Malformed RR -- no type/class/ttl/len!"); return(mDNSNULL); } rr->resrec.rrtype = (mDNSu16) ((mDNSu16)ptr[0] << 8 | ptr[1]); rr->resrec.rrclass = (mDNSu16)(((mDNSu16)ptr[2] << 8 | ptr[3]) & kDNSClass_Mask); rr->resrec.rroriginalttl = (mDNSu32) ((mDNSu32)ptr[4] << 24 | (mDNSu32)ptr[5] << 16 | (mDNSu32)ptr[6] << 8 | ptr[7]); if (rr->resrec.rroriginalttl > maxttl && (mDNSs32)rr->resrec.rroriginalttl != -1) rr->resrec.rroriginalttl = maxttl; // Note: We don't have to adjust m->NextCacheCheck here -- this is just getting a record into memory for // us to look at. If we decide to copy it into the cache, then we'll update m->NextCacheCheck accordingly. pktrdlength = (mDNSu16)((mDNSu16)ptr[8] << 8 | ptr[9]); // If mDNS record has cache-flush bit set, we mark it unique // For uDNS records, all are implicitly deemed unique (a single DNS server is always authoritative for the entire RRSet) if (ptr[2] & (kDNSClass_UniqueRRSet >> 8) || !InterfaceID) RecordType |= kDNSRecordTypePacketUniqueMask; ptr += 10; if (ptr + pktrdlength > end) { debugf("GetLargeResourceRecord: RDATA exceeds end of packet"); return(mDNSNULL); } end = ptr + pktrdlength; // Adjust end to indicate the end of the rdata for this resource record rr->resrec.rdata = (RData*)&rr->smallrdatastorage; rr->resrec.rdata->MaxRDLength = MaximumRDSize; if (pktrdlength > MaximumRDSize) { LogInfo("GetLargeResourceRecord: %s rdata size (%d) exceeds storage (%d)", DNSTypeName(rr->resrec.rrtype), pktrdlength, rr->resrec.rdata->MaxRDLength); goto fail; } if (!RecordType) LogMsg("GetLargeResourceRecord: No RecordType for %##s", rr->resrec.name->c); // IMPORTANT: Any record type we understand and unpack into a structure containing domainnames needs to have corresponding // cases in SameRDataBody() and RDataHashValue() to do a semantic comparison (or checksum) of the structure instead of a blind // bitwise memory compare (or sum). This is because a domainname is a fixed size structure holding variable-length data. // Any bytes past the logical end of the name are undefined, and a blind bitwise memory compare may indicate that // two domainnames are different when semantically they are the same name and it's only the unused bytes that differ. if (rr->resrec.rrclass == kDNSQClass_ANY && pktrdlength == 0) // Used in update packets to mean "Delete An RRset" (RFC 2136) rr->resrec.rdlength = 0; else if (!SetRData(msg, ptr, end, &rr->resrec, pktrdlength)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "GetLargeResourceRecord: SetRData failed for " PRI_DM_NAME " (" PUB_S ")", DM_NAME_PARAM(rr->resrec.name), DNSTypeName(rr->resrec.rrtype)); goto fail; } SetNewRData(&rr->resrec, mDNSNULL, 0); // Sets rdlength, rdestimate, rdatahash for us // Success! Now fill in RecordType to show this record contains valid data rr->resrec.RecordType = RecordType; return(end); fail: // If we were unable to parse the rdata in this record, we indicate that by // returing a 'kDNSRecordTypePacketNegative' record with rdlength set to zero rr->resrec.RecordType = kDNSRecordTypePacketNegative; rr->resrec.rdlength = 0; rr->resrec.rdestimate = 0; rr->resrec.rdatahash = 0; return(end); } mDNSexport const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end) { ptr = skipDomainName(msg, ptr, end); if (!ptr) { debugf("skipQuestion: Malformed domain name in DNS question section"); return(mDNSNULL); } if (ptr+4 > end) { debugf("skipQuestion: Malformed DNS question section -- no query type and class!"); return(mDNSNULL); } return(ptr+4); } mDNSexport const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID, DNSQuestion *question) { mDNSPlatformMemZero(question, sizeof(*question)); question->InterfaceID = InterfaceID; if (!InterfaceID) question->TargetQID = onesID; // In DNSQuestions we use TargetQID as the indicator of whether it's unicast or multicast ptr = getDomainName(msg, ptr, end, &question->qname); if (!ptr) { debugf("Malformed domain name in DNS question section"); return(mDNSNULL); } if (ptr+4 > end) { debugf("Malformed DNS question section -- no query type and class!"); return(mDNSNULL); } question->qnamehash = DomainNameHashValue(&question->qname); question->qtype = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); // Get type question->qclass = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); // and class return(ptr+4); } mDNSexport const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end) { int i; const mDNSu8 *ptr = msg->data; for (i = 0; i < msg->h.numQuestions && ptr; i++) ptr = skipQuestion(msg, ptr, end); return(ptr); } mDNSexport const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end) { int i; const mDNSu8 *ptr = LocateAnswers(msg, end); for (i = 0; i < msg->h.numAnswers && ptr; i++) ptr = skipResourceRecord(msg, ptr, end); return(ptr); } mDNSexport const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end) { int i; const mDNSu8 *ptr = LocateAuthorities(msg, end); for (i = 0; i < msg->h.numAuthorities; i++) ptr = skipResourceRecord(msg, ptr, end); return (ptr); } mDNSexport const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize) { int i; const mDNSu8 *ptr = LocateAdditionals(msg, end); // Locate the OPT record. // According to RFC 2671, "One OPT pseudo-RR can be added to the additional data section of either a request or a response." // This implies that there may be *at most* one OPT record per DNS message, in the Additional Section, // but not necessarily the *last* entry in the Additional Section. for (i = 0; ptr && i < msg->h.numAdditionals; i++) { if (ptr + DNSOpt_Header_Space + minsize <= end && // Make sure we have 11+minsize bytes of data ptr[0] == 0 && // Name must be root label ptr[1] == (kDNSType_OPT >> 8 ) && // rrtype OPT ptr[2] == (kDNSType_OPT & 0xFF) && ((mDNSu16)ptr[9] << 8 | (mDNSu16)ptr[10]) >= (mDNSu16)minsize) return(ptr); else ptr = skipResourceRecord(msg, ptr, end); } return(mDNSNULL); } // On success, GetLLQOptData returns pointer to storage within shared "m->rec"; // it is caller's responsibilty to clear m->rec.r.resrec.RecordType after use // Note: An OPT RDataBody actually contains one or more variable-length rdataOPT objects packed together // The code that currently calls this assumes there's only one, instead of iterating through the set mDNSexport const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end) { const mDNSu8 *ptr = LocateOptRR(msg, end, DNSOpt_LLQData_Space); if (ptr) { ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative) return(&m->rec.r.resrec.rdata->u.opt[0]); } return(mDNSNULL); } // Get the lease life of records in a dynamic update mDNSexport mDNSBool GetPktLease(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, mDNSu32 *const lease) { const mDNSu8 *ptr = LocateOptRR(msg, end, DNSOpt_LeaseData_Space); if (ptr) { ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_OPT) { const rdataOPT *o; const rdataOPT *const e = (const rdataOPT *)&m->rec.r.resrec.rdata->u.data[m->rec.r.resrec.rdlength]; for (o = &m->rec.r.resrec.rdata->u.opt[0]; o < e; o++) if (o->opt == kDNSOpt_Lease) { *lease = o->u.updatelease; m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it return mDNStrue; } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } return mDNSfalse; } #define DNS_OP_Name(X) ( \ (X) == kDNSFlag0_OP_StdQuery ? "" : \ (X) == kDNSFlag0_OP_Iquery ? "Iquery " : \ (X) == kDNSFlag0_OP_Status ? "Status " : \ (X) == kDNSFlag0_OP_Unused3 ? "Unused3 " : \ (X) == kDNSFlag0_OP_Notify ? "Notify " : \ (X) == kDNSFlag0_OP_Update ? "Update " : \ (X) == kDNSFlag0_OP_DSO ? "DSO " : "?? " ) #define DNS_RC_Name(X) ( \ (X) == kDNSFlag1_RC_NoErr ? "NoErr" : \ (X) == kDNSFlag1_RC_FormErr ? "FormErr" : \ (X) == kDNSFlag1_RC_ServFail ? "ServFail" : \ (X) == kDNSFlag1_RC_NXDomain ? "NXDomain" : \ (X) == kDNSFlag1_RC_NotImpl ? "NotImpl" : \ (X) == kDNSFlag1_RC_Refused ? "Refused" : \ (X) == kDNSFlag1_RC_YXDomain ? "YXDomain" : \ (X) == kDNSFlag1_RC_YXRRSet ? "YXRRSet" : \ (X) == kDNSFlag1_RC_NXRRSet ? "NXRRSet" : \ (X) == kDNSFlag1_RC_NotAuth ? "NotAuth" : \ (X) == kDNSFlag1_RC_NotZone ? "NotZone" : \ (X) == kDNSFlag1_RC_DSOTypeNI ? "DSOTypeNI" : "??" ) mDNSexport void mDNS_snprintf_add(char **ptr, const char *lim, const char *fmt, ...) { va_list args; mDNSu32 buflen, n; char *const dst = *ptr; buflen = (mDNSu32)(lim - dst); if (buflen > 0) { va_start(args, fmt); n = mDNS_vsnprintf(dst, buflen, fmt, args); va_end(args); *ptr = dst + n; } } #define DNSTypeString(X) (((X) == kDNSType_A) ? "A" : DNSTypeName(X)) #define ReadField16(PTR) ((mDNSu16)((((mDNSu16)((mDNSu8 *)(PTR))[0]) << 8) | ((mDNSu16)((mDNSu8 *)(PTR))[1]))) #define ReadField32(PTR) \ ((mDNSu32)( \ (((mDNSu32)((mDNSu8 *)(PTR))[0]) << 24) | \ (((mDNSu32)((mDNSu8 *)(PTR))[1]) << 16) | \ (((mDNSu32)((mDNSu8 *)(PTR))[2]) << 8) | \ ((mDNSu32)((mDNSu8 *)(PTR))[3]))) mDNSlocal void DNSMessageDumpToLog(const DNSMessage *const msg, const mDNSu8 *const end) { domainname *name = mDNSNULL; const mDNSu8 *ptr = msg->data; domainname nameStorage[2]; char questions[512]; questions[0] = '\0'; char *questions_dst = questions; const char *const questions_lim = &questions[512]; for (mDNSu32 i = 0; i < msg->h.numQuestions; i++) { mDNSu16 qtype, qclass; name = &nameStorage[0]; ptr = getDomainName(msg, ptr, end, name); if (!ptr) goto exit; if ((end - ptr) < 4) goto exit; qtype = ReadField16(&ptr[0]); qclass = ReadField16(&ptr[2]); ptr += 4; mDNS_snprintf_add(&questions_dst, questions_lim, " %##s %s", name->c, DNSTypeString(qtype)); if (qclass != kDNSClass_IN) mDNS_snprintf_add(&questions_dst, questions_lim, "/%u", qclass); mDNS_snprintf_add(&questions_dst, questions_lim, "?"); } char rrs[512]; rrs[0] = '\0'; char *rrs_dst = rrs; const char *const rrs_lim = &rrs[512]; const mDNSu32 rrcount = msg->h.numAnswers + msg->h.numAuthorities + msg->h.numAdditionals; for (mDNSu32 i = 0; i < rrcount; i++) { mDNSu16 rrtype, rrclass, rdlength; mDNSu32 ttl; int handled; const mDNSu8 *rdata; const domainname *const previousName = name; name = &nameStorage[(name == &nameStorage[0]) ? 1 : 0]; ptr = getDomainName(msg, ptr, end, name); if (!ptr) goto exit; if ((end - ptr) < 10) goto exit; rrtype = ReadField16(&ptr[0]); rrclass = ReadField16(&ptr[2]); ttl = ReadField32(&ptr[4]); rdlength = ReadField16(&ptr[8]); ptr += 10; if ((end - ptr) < rdlength) goto exit; rdata = ptr; if (i > 0) mDNS_snprintf_add(&rrs_dst, rrs_lim, ","); if (!previousName || !SameDomainName(name, previousName)) mDNS_snprintf_add(&rrs_dst, rrs_lim, " %##s", name); mDNS_snprintf_add(&rrs_dst, rrs_lim, " %s", DNSTypeString(rrtype)); if (rrclass != kDNSClass_IN) mDNS_snprintf_add(&rrs_dst, rrs_lim, "/%u", rrclass); mDNS_snprintf_add(&rrs_dst, rrs_lim, " "); handled = mDNSfalse; switch (rrtype) { case kDNSType_A: if (rdlength == 4) { mDNS_snprintf_add(&rrs_dst, rrs_lim, "%.4a", rdata); handled = mDNStrue; } break; case kDNSType_AAAA: if (rdlength == 16) { mDNS_snprintf_add(&rrs_dst, rrs_lim, "%.16a", rdata); handled = mDNStrue; } break; case kDNSType_CNAME: ptr = getDomainName(msg, rdata, end, name); if (!ptr) goto exit; mDNS_snprintf_add(&rrs_dst, rrs_lim, "%##s", name); handled = mDNStrue; break; case kDNSType_SOA: { mDNSu32 serial, refresh, retry, expire, minimum; domainname *const mname = &nameStorage[0]; domainname *const rname = &nameStorage[1]; name = mDNSNULL; ptr = getDomainName(msg, rdata, end, mname); if (!ptr) goto exit; ptr = getDomainName(msg, ptr, end, rname); if (!ptr) goto exit; if ((end - ptr) < 20) goto exit; serial = ReadField32(&ptr[0]); refresh = ReadField32(&ptr[4]); retry = ReadField32(&ptr[8]); expire = ReadField32(&ptr[12]); minimum = ReadField32(&ptr[16]); mDNS_snprintf_add(&rrs_dst, rrs_lim, "%##s %##s %lu %lu %lu %lu %lu", mname, rname, (unsigned long)serial, (unsigned long)refresh, (unsigned long)retry, (unsigned long)expire, (unsigned long)minimum); handled = mDNStrue; break; } default: break; } if (!handled) mDNS_snprintf_add(&rrs_dst, rrs_lim, "RDATA[%u]: %.*H", rdlength, rdlength, rdata); mDNS_snprintf_add(&rrs_dst, rrs_lim, " (%lu)", (unsigned long)ttl); ptr = rdata + rdlength; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[Q%u] DNS " PUB_S PUB_S " (%lu) (flags %02X%02X) RCODE: " PUB_S " (%d)" PUB_S PUB_S PUB_S PUB_S PUB_S PUB_S ":" PRI_S " %u/%u/%u " PRI_S, mDNSVal16(msg->h.id), DNS_OP_Name(msg->h.flags.b[0] & kDNSFlag0_OP_Mask), (msg->h.flags.b[0] & kDNSFlag0_QR_Response) ? "Response" : "Query", (unsigned long)(end - (const mDNSu8 *)msg), msg->h.flags.b[0], msg->h.flags.b[1], DNS_RC_Name(msg->h.flags.b[1] & kDNSFlag1_RC_Mask), msg->h.flags.b[1] & kDNSFlag1_RC_Mask, (msg->h.flags.b[0] & kDNSFlag0_AA) ? " AA" : "", (msg->h.flags.b[0] & kDNSFlag0_TC) ? " TC" : "", (msg->h.flags.b[0] & kDNSFlag0_RD) ? " RD" : "", (msg->h.flags.b[1] & kDNSFlag1_RA) ? " RA" : "", (msg->h.flags.b[1] & kDNSFlag1_AD) ? " AD" : "", (msg->h.flags.b[1] & kDNSFlag1_CD) ? " CD" : "", questions, msg->h.numAnswers, msg->h.numAuthorities, msg->h.numAdditionals, rrs); exit: return; } // Note: DumpPacket expects the packet header fields in host byte order, not network byte order mDNSexport void DumpPacket(mStatus status, mDNSBool sent, const char *transport, const mDNSAddr *srcaddr, mDNSIPPort srcport,const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end, mDNSInterfaceID interfaceID) { const mDNSAddr zeroIPv4Addr = { mDNSAddrType_IPv4, {{{ 0 }}} }; char action[32]; const char* interfaceName = "interface"; if (!status) mDNS_snprintf(action, sizeof(action), sent ? "Sent" : "Received"); else mDNS_snprintf(action, sizeof(action), "ERROR %d %sing", status, sent ? "Send" : "Receiv"); #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) interfaceName = InterfaceNameForID(&mDNSStorage, interfaceID); #endif LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[Q%u] " PUB_S " " PUB_S " DNS Message %lu bytes from " PRI_IP_ADDR ":%d to " PRI_IP_ADDR ":%d via " PUB_S " (%p)", mDNSVal16(msg->h.id), action, transport, (unsigned long)(end - (const mDNSu8 *)msg), srcaddr ? srcaddr : &zeroIPv4Addr, mDNSVal16(srcport), dstaddr ? dstaddr : &zeroIPv4Addr, mDNSVal16(dstport), interfaceName, interfaceID); DNSMessageDumpToLog(msg, end); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Packet Sending Functions #endif // Stub definition of TCPSocket_struct so we can access flags field. (Rest of TCPSocket_struct is platform-dependent.) struct TCPSocket_struct { mDNSIPPort port; TCPSocketFlags flags; /* ... */ }; // Stub definition of UDPSocket_struct so we can access port field. (Rest of UDPSocket_struct is platform-dependent.) struct UDPSocket_struct { mDNSIPPort port; /* ... */ }; // Note: When we sign a DNS message using DNSDigest_SignMessage(), the current real-time clock value is used, which // is why we generally defer signing until we send the message, to ensure the signature is as fresh as possible. mDNSexport mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end, mDNSInterfaceID InterfaceID, TCPSocket *tcpSrc, UDPSocket *udpSrc, const mDNSAddr *dst, mDNSIPPort dstport, DomainAuthInfo *authInfo, mDNSBool useBackgroundTrafficClass) { mStatus status = mStatus_NoError; const mDNSu16 numAdditionals = msg->h.numAdditionals; #if APPLE_OSX_mDNSResponder // maintain outbound packet statistics if (mDNSOpaque16IsZero(msg->h.id)) m->MulticastPacketsSent++; else m->UnicastPacketsSent++; #endif // APPLE_OSX_mDNSResponder // Zero-length message data is okay (e.g. for a DNS Update ack, where all we need is an ID and an error code if (end < msg->data || end - msg->data > AbsoluteMaxDNSMessageData) { LogMsg("mDNSSendDNSMessage: invalid message %p %p %d", msg->data, end, end - msg->data); return mStatus_BadParamErr; } // Put all the integer values in IETF byte-order (MSB first, LSB second) SwapDNSHeaderBytes(msg); if (authInfo) DNSDigest_SignMessage(msg, &end, authInfo, 0); // DNSDigest_SignMessage operates on message in network byte order if (!end) { LogMsg("mDNSSendDNSMessage: DNSDigest_SignMessage failed"); status = mStatus_NoMemoryErr; } else { // Send the packet on the wire if (!tcpSrc) status = mDNSPlatformSendUDP(m, msg, end, InterfaceID, udpSrc, dst, dstport, useBackgroundTrafficClass); else { mDNSu16 msglen = (mDNSu16)(end - (mDNSu8 *)msg); mDNSu8 lenbuf[2] = { (mDNSu8)(msglen >> 8), (mDNSu8)(msglen & 0xFF) }; char *buf; long nsent; // Try to send them in one packet if we can allocate enough memory buf = (char *) mDNSPlatformMemAllocate(msglen + 2); if (buf) { buf[0] = lenbuf[0]; buf[1] = lenbuf[1]; mDNSPlatformMemCopy(buf+2, msg, msglen); nsent = mDNSPlatformWriteTCP(tcpSrc, buf, msglen+2); if (nsent != (msglen + 2)) { LogMsg("mDNSSendDNSMessage: write message failed %d/%d", nsent, msglen); status = mStatus_ConnFailed; } mDNSPlatformMemFree(buf); } else { nsent = mDNSPlatformWriteTCP(tcpSrc, (char*)lenbuf, 2); if (nsent != 2) { LogMsg("mDNSSendDNSMessage: write msg length failed %d/%d", nsent, 2); status = mStatus_ConnFailed; } else { nsent = mDNSPlatformWriteTCP(tcpSrc, (char *)msg, msglen); if (nsent != msglen) { LogMsg("mDNSSendDNSMessage: write msg body failed %d/%d", nsent, msglen); status = mStatus_ConnFailed; } } } } } // Swap the integer values back the way they were (remember that numAdditionals may have been changed by putHINFO and/or SignMessage) SwapDNSHeaderBytes(msg); // Dump the packet with the HINFO and TSIG if (mDNS_PacketLoggingEnabled && !mDNSOpaque16IsZero(msg->h.id)) { char *transport = "UDP"; mDNSIPPort portNumber = udpSrc ? udpSrc->port : MulticastDNSPort; if (tcpSrc) { if (tcpSrc->flags) transport = "TLS"; else transport = "TCP"; portNumber = tcpSrc->port; } DumpPacket(status, mDNStrue, transport, mDNSNULL, portNumber, dst, dstport, msg, end, InterfaceID); } // put the number of additionals back the way it was msg->h.numAdditionals = numAdditionals; return(status); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - RR List Management & Task Management #endif mDNSexport void mDNS_Lock_(mDNS *const m, const char * const functionname) { // MUST grab the platform lock FIRST! mDNSPlatformLock(m); // Normally, mDNS_reentrancy is zero and so is mDNS_busy // However, when we call a client callback mDNS_busy is one, and we increment mDNS_reentrancy too // If that client callback does mDNS API calls, mDNS_reentrancy and mDNS_busy will both be one // If mDNS_busy != mDNS_reentrancy that's a bad sign if (m->mDNS_busy != m->mDNS_reentrancy) LogFatalError("%s: mDNS_Lock: Locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", functionname, m->mDNS_busy, m->mDNS_reentrancy); // If this is an initial entry into the mDNSCore code, set m->timenow // else, if this is a re-entrant entry into the mDNSCore code, m->timenow should already be set if (m->mDNS_busy == 0) { if (m->timenow) LogMsg("%s: mDNS_Lock: m->timenow already set (%ld/%ld)", functionname, m->timenow, mDNS_TimeNow_NoLock(m)); m->timenow = mDNS_TimeNow_NoLock(m); if (m->timenow == 0) m->timenow = 1; } else if (m->timenow == 0) { LogMsg("%s: mDNS_Lock: m->mDNS_busy is %ld but m->timenow not set", functionname, m->mDNS_busy); m->timenow = mDNS_TimeNow_NoLock(m); if (m->timenow == 0) m->timenow = 1; } if (m->timenow_last - m->timenow > 0) { m->timenow_adjust += m->timenow_last - m->timenow; LogMsg("%s: mDNSPlatformRawTime went backwards by %ld ticks; setting correction factor to %ld", functionname, m->timenow_last - m->timenow, m->timenow_adjust); m->timenow = m->timenow_last; } m->timenow_last = m->timenow; // Increment mDNS_busy so we'll recognise re-entrant calls m->mDNS_busy++; } mDNSlocal AuthRecord *AnyLocalRecordReady(const mDNS *const m) { AuthRecord *rr; for (rr = m->NewLocalRecords; rr; rr = rr->next) if (LocalRecordReady(rr)) return rr; return mDNSNULL; } mDNSlocal mDNSs32 GetNextScheduledEvent(const mDNS *const m) { mDNSs32 e = m->timenow + FutureTime; if (m->mDNSPlatformStatus != mStatus_NoError) return(e); if (m->NewQuestions) { if (m->NewQuestions->DelayAnswering) e = m->NewQuestions->DelayAnswering; else return(m->timenow); } if (m->NewLocalOnlyQuestions) return(m->timenow); if (m->NewLocalRecords && AnyLocalRecordReady(m)) return(m->timenow); if (m->NewLocalOnlyRecords) return(m->timenow); if (m->SPSProxyListChanged) return(m->timenow); if (m->LocalRemoveEvents) return(m->timenow); #ifndef UNICAST_DISABLED if (e - m->NextuDNSEvent > 0) e = m->NextuDNSEvent; if (e - m->NextScheduledNATOp > 0) e = m->NextScheduledNATOp; if (m->NextSRVUpdate && e - m->NextSRVUpdate > 0) e = m->NextSRVUpdate; #endif if (e - m->NextCacheCheck > 0) e = m->NextCacheCheck; if (e - m->NextScheduledSPS > 0) e = m->NextScheduledSPS; if (e - m->NextScheduledKA > 0) e = m->NextScheduledKA; #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (m->NextBonjourDisableTime && (e - m->NextBonjourDisableTime > 0)) e = m->NextBonjourDisableTime; #endif // NextScheduledSPRetry only valid when DelaySleep not set if (!m->DelaySleep && m->SleepLimit && e - m->NextScheduledSPRetry > 0) e = m->NextScheduledSPRetry; if (m->DelaySleep && e - m->DelaySleep > 0) e = m->DelaySleep; if (m->SuppressSending) { if (e - m->SuppressSending > 0) e = m->SuppressSending; } else { if (e - m->NextScheduledQuery > 0) e = m->NextScheduledQuery; if (e - m->NextScheduledProbe > 0) e = m->NextScheduledProbe; if (e - m->NextScheduledResponse > 0) e = m->NextScheduledResponse; } if (e - m->NextScheduledStopTime > 0) e = m->NextScheduledStopTime; if (m->NextBLEServiceTime && (e - m->NextBLEServiceTime > 0)) e = m->NextBLEServiceTime; return(e); } #define LogTSE TSE++,LogMsg mDNSexport void ShowTaskSchedulingError(mDNS *const m) { int TSE = 0; AuthRecord *rr; mDNS_Lock(m); LogMsg("Task Scheduling Error: *** Continuously busy for more than a second"); // Note: To accurately diagnose *why* we're busy, the debugging code here needs to mirror the logic in GetNextScheduledEvent above if (m->NewQuestions && (!m->NewQuestions->DelayAnswering || m->timenow - m->NewQuestions->DelayAnswering >= 0)) LogTSE("Task Scheduling Error: NewQuestion %##s (%s)", m->NewQuestions->qname.c, DNSTypeName(m->NewQuestions->qtype)); if (m->NewLocalOnlyQuestions) LogTSE("Task Scheduling Error: NewLocalOnlyQuestions %##s (%s)", m->NewLocalOnlyQuestions->qname.c, DNSTypeName(m->NewLocalOnlyQuestions->qtype)); if (m->NewLocalRecords) { rr = AnyLocalRecordReady(m); if (rr) LogTSE("Task Scheduling Error: NewLocalRecords %s", ARDisplayString(m, rr)); } if (m->NewLocalOnlyRecords) LogTSE("Task Scheduling Error: NewLocalOnlyRecords"); if (m->SPSProxyListChanged) LogTSE("Task Scheduling Error: SPSProxyListChanged"); if (m->LocalRemoveEvents) LogTSE("Task Scheduling Error: LocalRemoveEvents"); #ifndef UNICAST_DISABLED if (m->timenow - m->NextuDNSEvent >= 0) LogTSE("Task Scheduling Error: m->NextuDNSEvent %d", m->timenow - m->NextuDNSEvent); if (m->timenow - m->NextScheduledNATOp >= 0) LogTSE("Task Scheduling Error: m->NextScheduledNATOp %d", m->timenow - m->NextScheduledNATOp); if (m->NextSRVUpdate && m->timenow - m->NextSRVUpdate >= 0) LogTSE("Task Scheduling Error: m->NextSRVUpdate %d", m->timenow - m->NextSRVUpdate); #endif if (m->timenow - m->NextCacheCheck >= 0) LogTSE("Task Scheduling Error: m->NextCacheCheck %d", m->timenow - m->NextCacheCheck); if (m->timenow - m->NextScheduledSPS >= 0) LogTSE("Task Scheduling Error: m->NextScheduledSPS %d", m->timenow - m->NextScheduledSPS); if (m->timenow - m->NextScheduledKA >= 0) LogTSE("Task Scheduling Error: m->NextScheduledKA %d", m->timenow - m->NextScheduledKA); if (!m->DelaySleep && m->SleepLimit && m->timenow - m->NextScheduledSPRetry >= 0) LogTSE("Task Scheduling Error: m->NextScheduledSPRetry %d", m->timenow - m->NextScheduledSPRetry); if (m->DelaySleep && m->timenow - m->DelaySleep >= 0) LogTSE("Task Scheduling Error: m->DelaySleep %d", m->timenow - m->DelaySleep); if (m->SuppressSending && m->timenow - m->SuppressSending >= 0) LogTSE("Task Scheduling Error: m->SuppressSending %d", m->timenow - m->SuppressSending); if (m->timenow - m->NextScheduledQuery >= 0) LogTSE("Task Scheduling Error: m->NextScheduledQuery %d", m->timenow - m->NextScheduledQuery); if (m->timenow - m->NextScheduledProbe >= 0) LogTSE("Task Scheduling Error: m->NextScheduledProbe %d", m->timenow - m->NextScheduledProbe); if (m->timenow - m->NextScheduledResponse >= 0) LogTSE("Task Scheduling Error: m->NextScheduledResponse %d", m->timenow - m->NextScheduledResponse); if (m->timenow - m->NextScheduledStopTime >= 0) LogTSE("Task Scheduling Error: m->NextScheduledStopTime %d", m->timenow - m->NextScheduledStopTime); if (m->timenow - m->NextScheduledEvent >= 0) LogTSE("Task Scheduling Error: m->NextScheduledEvent %d", m->timenow - m->NextScheduledEvent); if (m->NetworkChanged && m->timenow - m->NetworkChanged >= 0) LogTSE("Task Scheduling Error: NetworkChanged %d", m->timenow - m->NetworkChanged); if (!TSE) LogMsg("Task Scheduling Error: *** No likely causes identified"); else LogMsg("Task Scheduling Error: *** %d potential cause%s identified (significant only if the same cause consistently appears)", TSE, TSE > 1 ? "s" : ""); mDNS_Unlock(m); } mDNSexport void mDNS_Unlock_(mDNS *const m, const char *const functionname) { // Decrement mDNS_busy m->mDNS_busy--; // Check for locking failures if (m->mDNS_busy != m->mDNS_reentrancy) LogFatalError("%s: mDNS_Unlock: Locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", functionname, m->mDNS_busy, m->mDNS_reentrancy); // If this is a final exit from the mDNSCore code, set m->NextScheduledEvent and clear m->timenow if (m->mDNS_busy == 0) { m->NextScheduledEvent = GetNextScheduledEvent(m); if (m->timenow == 0) LogMsg("%s: mDNS_Unlock: ERROR! m->timenow aready zero", functionname); m->timenow = 0; } // MUST release the platform lock LAST! mDNSPlatformUnlock(m); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Specialized mDNS version of vsnprintf #endif static const struct mDNSprintf_format { unsigned leftJustify : 1; unsigned forceSign : 1; unsigned zeroPad : 1; unsigned havePrecision : 1; unsigned hSize : 1; unsigned lSize : 1; char altForm; char sign; // +, - or space unsigned int fieldWidth; unsigned int precision; } mDNSprintf_format_default = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; #define kHexDigitsLowercase "0123456789abcdef" #define kHexDigitsUppercase "0123456789ABCDEF"; mDNSexport mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg) { mDNSu32 nwritten = 0; int c; if (buflen == 0) return(0); buflen--; // Pre-reserve one space in the buffer for the terminating null if (buflen == 0) goto exit; for (c = *fmt; c != 0; c = *++fmt) { unsigned long n; int hexdump = mDNSfalse; if (c != '%') { *sbuffer++ = (char)c; if (++nwritten >= buflen) goto exit; } else { unsigned int i=0, j; // The mDNS Vsprintf Argument Conversion Buffer is used as a temporary holding area for // generating decimal numbers, hexdecimal numbers, IP addresses, domain name strings, etc. // The size needs to be enough for a 256-byte domain name plus some error text. #define mDNS_VACB_Size 300 char mDNS_VACB[mDNS_VACB_Size]; #define mDNS_VACB_Lim (&mDNS_VACB[mDNS_VACB_Size]) #define mDNS_VACB_Remain(s) ((mDNSu32)(mDNS_VACB_Lim - s)) char *s = mDNS_VACB_Lim, *digits; struct mDNSprintf_format F = mDNSprintf_format_default; while (1) // decode flags { c = *++fmt; if (c == '-') F.leftJustify = 1; else if (c == '+') F.forceSign = 1; else if (c == ' ') F.sign = ' '; else if (c == '#') F.altForm++; else if (c == '0') F.zeroPad = 1; else break; } if (c == '*') // decode field width { int f = va_arg(arg, int); if (f < 0) { f = -f; F.leftJustify = 1; } F.fieldWidth = (unsigned int)f; c = *++fmt; } else { for (; c >= '0' && c <= '9'; c = *++fmt) F.fieldWidth = (10 * F.fieldWidth) + (c - '0'); } if (c == '.') // decode precision { if ((c = *++fmt) == '*') { F.precision = va_arg(arg, unsigned int); c = *++fmt; } else for (; c >= '0' && c <= '9'; c = *++fmt) F.precision = (10 * F.precision) + (c - '0'); F.havePrecision = 1; } if (F.leftJustify) F.zeroPad = 0; conv: switch (c) // perform appropriate conversion { case 'h': F.hSize = 1; c = *++fmt; goto conv; case 'l': // fall through case 'L': F.lSize = 1; c = *++fmt; goto conv; case 'd': case 'i': if (F.lSize) n = (unsigned long)va_arg(arg, long); else n = (unsigned long)va_arg(arg, int); if (F.hSize) n = (short) n; if ((long) n < 0) { n = (unsigned long)-(long)n; F.sign = '-'; } else if (F.forceSign) F.sign = '+'; goto decimal; case 'u': if (F.lSize) n = va_arg(arg, unsigned long); else n = va_arg(arg, unsigned int); if (F.hSize) n = (unsigned short) n; F.sign = 0; goto decimal; decimal: if (!F.havePrecision) { if (F.zeroPad) { F.precision = F.fieldWidth; if (F.sign) --F.precision; } if (F.precision < 1) F.precision = 1; } if (F.precision > mDNS_VACB_Size - 1) F.precision = mDNS_VACB_Size - 1; for (i = 0; n; n /= 10, i++) *--s = (char)(n % 10 + '0'); for (; i < F.precision; i++) *--s = '0'; if (F.sign) { *--s = F.sign; i++; } break; case 'o': if (F.lSize) n = va_arg(arg, unsigned long); else n = va_arg(arg, unsigned int); if (F.hSize) n = (unsigned short) n; if (!F.havePrecision) { if (F.zeroPad) F.precision = F.fieldWidth; if (F.precision < 1) F.precision = 1; } if (F.precision > mDNS_VACB_Size - 1) F.precision = mDNS_VACB_Size - 1; for (i = 0; n; n /= 8, i++) *--s = (char)(n % 8 + '0'); if (F.altForm && i && *s != '0') { *--s = '0'; i++; } for (; i < F.precision; i++) *--s = '0'; break; case 'a': { unsigned char *a = va_arg(arg, unsigned char *); if (!a) { static char emsg[] = "<>"; s = emsg; i = sizeof(emsg)-1; } else { s = mDNS_VACB; // Adjust s to point to the start of the buffer, not the end if (F.altForm) { mDNSAddr *ip = (mDNSAddr*)a; switch (ip->type) { case mDNSAddrType_IPv4: F.precision = 4; a = (unsigned char *)&ip->ip.v4; break; case mDNSAddrType_IPv6: F.precision = 16; a = (unsigned char *)&ip->ip.v6; break; default: F.precision = 0; break; } } if (F.altForm && !F.precision) i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "«ZERO ADDRESS»"); else switch (F.precision) { case 4: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%d.%d.%d.%d", a[0], a[1], a[2], a[3]); break; case 6: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%02X:%02X:%02X:%02X:%02X:%02X", a[0], a[1], a[2], a[3], a[4], a[5]); break; case 16: { // Print IPv6 addresses according to RFC 5952, A Recommendation for IPv6 Address Text // Representation. See . int idx, runLen = 0, runStart = 0, maxRunLen = 0, maxRunStart = 0, maxRunEnd; // Find the leftmost longest run of consecutive zero hextets. for (idx = 0; idx < 8; ++idx) { const unsigned int hextet = (a[idx * 2] << 8) | a[(idx * 2) + 1]; if (hextet == 0) { if (runLen++ == 0) runStart = idx; if (runLen > maxRunLen) { maxRunStart = runStart; maxRunLen = runLen; } } else { // If the number of remaining hextets is less than or equal to the length of the longest // run so far, then we've found the leftmost longest run. if ((8 - (idx + 1)) <= maxRunLen) break; runLen = 0; } } // Compress the leftmost longest run of two or more consecutive zero hextets as "::". // For each reminaing hextet, suppress zeros leading up to the least-significant nibble, which // is always written, even if it's zero. Because of this requirement, it's easier to write the // IPv6 address in reverse. Also, write a colon separator before each hextet except for the // first one. s = mDNS_VACB_Lim; maxRunEnd = (maxRunLen >= 2) ? (maxRunStart + maxRunLen - 1) : -1; for (idx = 7; idx >= 0; --idx) { if (idx == maxRunEnd) { if (idx == 7) *--s = ':'; idx = maxRunStart; *--s = ':'; } else { unsigned int hextet = (a[idx * 2] << 8) | a[(idx * 2) + 1]; do { *--s = kHexDigitsLowercase[hextet % 16]; hextet /= 16; } while (hextet); if (idx > 0) *--s = ':'; } } i = (unsigned int)(mDNS_VACB_Lim - s); } break; default: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%s", "<< ERROR: Must specify" " address size (i.e. %.4a=IPv4, %.6a=Ethernet, %.16a=IPv6) >>"); break; } } } break; case 'p': F.havePrecision = F.lSize = 1; F.precision = sizeof(void*) * 2; // 8 characters on 32-bit; 16 characters on 64-bit /* FALLTHROUGH */ case 'X': digits = kHexDigitsUppercase; goto hexadecimal; case 'x': digits = kHexDigitsLowercase; hexadecimal: if (F.lSize) n = va_arg(arg, unsigned long); else n = va_arg(arg, unsigned int); if (F.hSize) n = (unsigned short) n; if (!F.havePrecision) { if (F.zeroPad) { F.precision = F.fieldWidth; if (F.altForm) F.precision -= 2; } if (F.precision < 1) F.precision = 1; } if (F.precision > mDNS_VACB_Size - 1) F.precision = mDNS_VACB_Size - 1; for (i = 0; n; n /= 16, i++) *--s = digits[n % 16]; for (; i < F.precision; i++) *--s = '0'; if (F.altForm) { *--s = (char)c; *--s = '0'; i += 2; } break; case 'c': *--s = (char)va_arg(arg, int); i = 1; break; case 's': s = va_arg(arg, char *); if (!s) { static char emsg[] = "<>"; s = emsg; i = sizeof(emsg)-1; } else switch (F.altForm) { case 0: i=0; if (!F.havePrecision) // C string while (s[i]) i++; else { while ((i < F.precision) && s[i]) i++; // Make sure we don't truncate in the middle of a UTF-8 character // If last character we got was any kind of UTF-8 multi-byte character, // then see if we have to back up. // This is not as easy as the similar checks below, because // here we can't assume it's safe to examine the *next* byte, so we // have to confine ourselves to working only backwards in the string. j = i; // Record where we got to // Now, back up until we find first non-continuation-char while (i>0 && (s[i-1] & 0xC0) == 0x80) i--; // Now s[i-1] is the first non-continuation-char // and (j-i) is the number of continuation-chars we found if (i>0 && (s[i-1] & 0xC0) == 0xC0) // If we found a start-char { i--; // Tentatively eliminate this start-char as well // Now (j-i) is the number of characters we're considering eliminating. // To be legal UTF-8, the start-char must contain (j-i) one-bits, // followed by a zero bit. If we shift it right by (7-(j-i)) bits // (with sign extension) then the result has to be 0xFE. // If this is right, then we reinstate the tentatively eliminated bytes. if (((j-i) < 7) && (((s[i] >> (7-(j-i))) & 0xFF) == 0xFE)) i = j; } } break; case 1: i = (unsigned char) *s++; break; // Pascal string case 2: { // DNS label-sequence name unsigned char *a = (unsigned char *)s; s = mDNS_VACB; // Adjust s to point to the start of the buffer, not the end if (*a == 0) *s++ = '.'; // Special case for root DNS name while (*a) { char buf[63*4+1]; if (*a > 63) { s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "<>", *a); break; } if (s + *a >= &mDNS_VACB[254]) { s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "<>"); break; } // Need to use ConvertDomainLabelToCString to do proper escaping here, // so it's clear what's a literal dot and what's a label separator ConvertDomainLabelToCString((domainlabel*)a, buf); s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "%s.", buf); a += 1 + *a; } i = (mDNSu32)(s - mDNS_VACB); s = mDNS_VACB; // Reset s back to the start of the buffer break; } } // Make sure we don't truncate in the middle of a UTF-8 character (see similar comment below) if (F.havePrecision && i > F.precision) { i = F.precision; while (i>0 && (s[i] & 0xC0) == 0x80) i--;} break; case 'H': { s = va_arg(arg, char *); hexdump = mDNStrue; } break; case 'n': s = va_arg(arg, char *); if (F.hSize) *(short *) s = (short)nwritten; else if (F.lSize) *(long *) s = (long)nwritten; else *(int *) s = (int)nwritten; continue; default: s = mDNS_VACB; i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "<>", c); break; case '%': *sbuffer++ = (char)c; if (++nwritten >= buflen) goto exit; break; } if (i < F.fieldWidth && !F.leftJustify) // Pad on the left do { *sbuffer++ = ' '; if (++nwritten >= buflen) goto exit; } while (i < --F.fieldWidth); if (hexdump) { char *dst = sbuffer; const char *const lim = &sbuffer[buflen - nwritten]; if (F.havePrecision) { for (i = 0; (i < F.precision) && (dst < lim); i++) { const unsigned int b = (unsigned int) *s++; if (i > 0) *dst++ = ' '; if (dst < lim) *dst++ = kHexDigitsLowercase[(b >> 4) & 0xF]; if (dst < lim) *dst++ = kHexDigitsLowercase[ b & 0xF]; } } i = (unsigned int)(dst - sbuffer); sbuffer = dst; } else { // Make sure we don't truncate in the middle of a UTF-8 character. // Note: s[i] is the first eliminated character; i.e. the next character *after* the last character of the // allowed output. If s[i] is a UTF-8 continuation character, then we've cut a unicode character in half, // so back up 'i' until s[i] is no longer a UTF-8 continuation character. (if the input was proprly // formed, s[i] will now be the UTF-8 start character of the multi-byte character we just eliminated). if (i > buflen - nwritten) { i = buflen - nwritten; while (i>0 && (s[i] & 0xC0) == 0x80) i--;} for (j=0; j= buflen) goto exit; for (; i < F.fieldWidth; i++) // Pad on the right { *sbuffer++ = ' '; if (++nwritten >= buflen) goto exit; } } } exit: *sbuffer++ = 0; return(nwritten); } mDNSexport mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...) { mDNSu32 length; va_list ptr; va_start(ptr,fmt); length = mDNS_vsnprintf(sbuffer, buflen, fmt, ptr); va_end(ptr); return(length); } #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSexport mDNSu32 mDNS_GetNextResolverGroupID(void) { static mDNSu32 lastID = 0; if (++lastID == 0) lastID = 1; // Valid resolver group IDs are non-zero. return(lastID); } #endif #define kReverseIPv6Domain ((const domainname *) "\x3" "ip6" "\x4" "arpa") mDNSexport mDNSBool GetReverseIPv6Addr(const domainname *name, mDNSu8 outIPv6[16]) { const mDNSu8 * ptr; int i; mDNSu8 ipv6[16]; // If the name is of the form "x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.ip6.arpa.", where each x // is a hex digit, then the sequence of 32 hex digit labels represents the nibbles of an IPv6 address in reverse order. // See . ptr = name->c; for (i = 0; i < 32; i++) { unsigned int c, nibble; const int j = 15 - (i / 2); if (*ptr++ != 1) return (mDNSfalse); // If this label's length is not 1, then fail. c = *ptr++; // Get label byte. if ( (c >= '0') && (c <= '9')) nibble = c - '0'; // If it's a hex digit, get its numeric value. else if ((c >= 'a') && (c <= 'f')) nibble = (c - 'a') + 10; else if ((c >= 'A') && (c <= 'F')) nibble = (c - 'A') + 10; else return (mDNSfalse); // Otherwise, fail. if ((i % 2) == 0) { ipv6[j] = (mDNSu8)nibble; } else { ipv6[j] |= (mDNSu8)(nibble << 4); } } // The rest of the name needs to be "ip6.arpa.". If it isn't, fail. if (!SameDomainName((const domainname *)ptr, kReverseIPv6Domain)) return (mDNSfalse); if (outIPv6) mDNSPlatformMemCopy(outIPv6, ipv6, 16); return (mDNStrue); } #endif // !STANDALONE /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __DNSCOMMON_H_ #define __DNSCOMMON_H_ #include "mDNSEmbeddedAPI.h" #ifdef __cplusplus extern "C" { #endif //************************************************************************************************************* // Macros // Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion // e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4" // To expand "version" to its value before making the string, use STRINGIFY(version) instead #define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s #define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - DNS Protocol Constants #endif typedef enum { kDNSFlag0_QR_Mask = 0x80, // Query or response? kDNSFlag0_QR_Query = 0x00, kDNSFlag0_QR_Response = 0x80, kDNSFlag0_OP_Mask = 0xF << 3, // Operation type kDNSFlag0_OP_StdQuery = 0x0 << 3, kDNSFlag0_OP_Iquery = 0x1 << 3, kDNSFlag0_OP_Status = 0x2 << 3, kDNSFlag0_OP_Unused3 = 0x3 << 3, kDNSFlag0_OP_Notify = 0x4 << 3, kDNSFlag0_OP_Update = 0x5 << 3, kDNSFlag0_OP_DSO = 0x6 << 3, kDNSFlag0_QROP_Mask = kDNSFlag0_QR_Mask | kDNSFlag0_OP_Mask, kDNSFlag0_AA = 0x04, // Authoritative Answer? kDNSFlag0_TC = 0x02, // Truncated? kDNSFlag0_RD = 0x01, // Recursion Desired? kDNSFlag1_RA = 0x80, // Recursion Available? kDNSFlag1_Zero = 0x40, // Reserved; must be zero kDNSFlag1_AD = 0x20, // Authentic Data [RFC 2535] kDNSFlag1_CD = 0x10, // Checking Disabled [RFC 2535] kDNSFlag1_RC_Mask = 0x0F, // Response code kDNSFlag1_RC_NoErr = 0x00, kDNSFlag1_RC_FormErr = 0x01, kDNSFlag1_RC_ServFail = 0x02, kDNSFlag1_RC_NXDomain = 0x03, kDNSFlag1_RC_NotImpl = 0x04, kDNSFlag1_RC_Refused = 0x05, kDNSFlag1_RC_YXDomain = 0x06, kDNSFlag1_RC_YXRRSet = 0x07, kDNSFlag1_RC_NXRRSet = 0x08, kDNSFlag1_RC_NotAuth = 0x09, kDNSFlag1_RC_NotZone = 0x0A, kDNSFlag1_RC_DSOTypeNI = 0x0B } DNS_Flags; typedef enum { TSIG_ErrBadSig = 16, TSIG_ErrBadKey = 17, TSIG_ErrBadTime = 18 } TSIG_ErrorCode; // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - General Utility Functions #endif extern NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf); extern mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf); extern mDNSu32 mDNSRandom(mDNSu32 max); // Returns pseudo-random result from zero to max inclusive #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern mDNSu32 mDNS_GetNextResolverGroupID(void); #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Domain Name Utility Functions #endif #define mDNSSubTypeLabel "\x04_sub" #define mDNSIsDigit(X) ((X) >= '0' && (X) <= '9') #define mDNSIsUpperCase(X) ((X) >= 'A' && (X) <= 'Z') #define mDNSIsLowerCase(X) ((X) >= 'a' && (X) <= 'z') #define mDNSIsLetter(X) (mDNSIsUpperCase(X) || mDNSIsLowerCase(X)) // We believe we have adequate safeguards to protect against cache poisoning. // In the event that someone does find a workable cache poisoning attack, we want to limit the lifetime of the poisoned entry. // We set the maximum allowable TTL to one hour. // With the 25% correction factor to avoid the DNS Zeno's paradox bug, that gives us an actual maximum lifetime of 75 minutes. #define mDNSMaximumMulticastTTLSeconds (mDNSu32)4500 #define mDNSMaximumUnicastTTLSeconds (mDNSu32)3600 #define mDNSValidHostChar(X, notfirst, notlast) (mDNSIsLetter(X) || mDNSIsDigit(X) || ((notfirst) && (notlast) && (X) == '-') ) extern mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent); extern int CountLabels(const domainname *d); extern const domainname *SkipLeadingLabels(const domainname *d, int skip); extern mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max); extern mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText); extern mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText); extern void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText); #define ValidateDomainName(N) (DomainNameLength(N) <= MAX_DOMAIN_NAME) // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Resource Record Utility Functions #endif // IdenticalResourceRecord returns true if two resources records have // the same name, type, class, and identical rdata (InterfaceID and TTL may differ) // IdenticalSameNameRecord is the same, except it skips the expensive SameDomainName() check, // which is at its most expensive and least useful in cases where we know in advance that the names match // Note: The dominant use of IdenticalResourceRecord is from ProcessQuery(), handling known-answer lists. In this case // it's common to have a whole bunch or records with exactly the same name (e.g. "_http._tcp.local") but different RDATA. // The SameDomainName() check is expensive when the names match, and in this case *all* the names match, so we // used to waste a lot of CPU time verifying that the names match, only then to find that the RDATA is different. // We observed mDNSResponder spending 30% of its total CPU time on this single task alone. // By swapping the checks so that we check the RDATA first, we can quickly detect when it's different // (99% of the time) and then bail out before we waste time on the expensive SameDomainName() check. #define IdenticalResourceRecord(r1,r2) ( \ (r1)->rrtype == (r2)->rrtype && \ (r1)->rrclass == (r2)->rrclass && \ (r1)->namehash == (r2)->namehash && \ (r1)->rdlength == (r2)->rdlength && \ (r1)->rdatahash == (r2)->rdatahash && \ SameRDataBody((r1), &(r2)->rdata->u, SameDomainName) && \ SameDomainName((r1)->name, (r2)->name)) #define IdenticalSameNameRecord(r1,r2) ( \ (r1)->rrtype == (r2)->rrtype && \ (r1)->rrclass == (r2)->rrclass && \ (r1)->rdlength == (r2)->rdlength && \ (r1)->rdatahash == (r2)->rdatahash && \ SameRDataBody((r1), &(r2)->rdata->u, SameDomainName)) // A given RRType answers a QuestionType if RRType is CNAME, or types match, or QuestionType is ANY, // or the RRType is NSEC and positively asserts the nonexistence of the type being requested #define RRTypeAnswersQuestionType(R,Q) ((R)->rrtype == kDNSType_CNAME || (R)->rrtype == (Q) || (Q) == kDNSQType_ANY || RRAssertsNonexistence((R),(Q))) // Unicast NSEC records have the NSEC bit set whereas the multicast NSEC ones don't #define UNICAST_NSEC(rr) ((rr)->rrtype == kDNSType_NSEC && RRAssertsExistence((rr), kDNSType_NSEC)) extern mDNSu32 RDataHashValue(const ResourceRecord *const rr); extern mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2, DomainNameComparisonFn *samename); extern mDNSBool SameNameCacheRecordAnswersQuestion(const CacheRecord *const cr, const DNSQuestion *const q); extern mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q); extern mDNSBool AuthRecordAnswersQuestion(const AuthRecord *const ar, const DNSQuestion *const q); extern mDNSBool CacheRecordAnswersQuestion(const CacheRecord *const cr, const DNSQuestion *const q); extern mDNSBool AnyTypeRecordAnswersQuestion (const AuthRecord *const ar, const DNSQuestion *const q); extern mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord *const rr, const DNSQuestion *const q); extern mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord *const rr, const DNSQuestion *const q); extern mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate); extern mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd); extern mStatus DNSNameToLowerCase(domainname *d, domainname *result); #define GetRRDomainNameTarget(RR) ( \ ((RR)->rrtype == kDNSType_NS || (RR)->rrtype == kDNSType_CNAME || (RR)->rrtype == kDNSType_PTR || (RR)->rrtype == kDNSType_DNAME) ? &(RR)->rdata->u.name : \ ((RR)->rrtype == kDNSType_MX || (RR)->rrtype == kDNSType_AFSDB || (RR)->rrtype == kDNSType_RT || (RR)->rrtype == kDNSType_KX ) ? &(RR)->rdata->u.mx.exchange : \ ((RR)->rrtype == kDNSType_SRV ) ? &(RR)->rdata->u.srv.target : mDNSNULL ) #define LocalRecordReady(X) ((X)->resrec.RecordType != kDNSRecordTypeUnique) // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNS Message Creation Functions #endif extern void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags); extern const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname); extern mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name); extern mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr); // If we have a single large record to put in the packet, then we allow the packet to be up to 9K bytes, // but in the normal case we try to keep the packets below 1500 to avoid IP fragmentation on standard Ethernet #define AllowedRRSpace(msg) (((msg)->h.numAnswers || (msg)->h.numAuthorities || (msg)->h.numAdditionals) ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData) extern mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, const ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit); #define PutResourceRecordTTL(msg, ptr, count, rr, ttl) \ PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AllowedRRSpace(msg)) #define PutResourceRecordTTLJumbo(msg, ptr, count, rr, ttl) \ PutResourceRecordTTLWithLimit((msg), (ptr), (count), (rr), (ttl), (msg)->data + AbsoluteMaxDNSMessageData) #define PutResourceRecord(MSG, P, C, RR) PutResourceRecordTTL((MSG), (P), (C), (RR), (RR)->rroriginalttl) // The PutRR_OS variants assume a local variable 'm', put build the packet at m->omsg, // and assume local variables 'OwnerRecordSpace' & 'TraceRecordSpace' indicating how many bytes (if any) to reserve to add an OWNER/TRACER option at the end #define PutRR_OS_TTL(ptr, count, rr, ttl) \ PutResourceRecordTTLWithLimit(&m->omsg, (ptr), (count), (rr), (ttl), m->omsg.data + AllowedRRSpace(&m->omsg) - OwnerRecordSpace - TraceRecordSpace) #define PutRR_OS(P, C, RR) PutRR_OS_TTL((P), (C), (RR), (RR)->rroriginalttl) extern mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass); extern mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass); extern mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *const msg, mDNSu8 *const ptr, mDNSu8 *const end); extern mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr); extern mDNSu8 *putDeletionRecordWithLimit(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr, mDNSu8 *limit); extern mDNSu8 *putDeleteRRSetWithLimit(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype, mDNSu8 *limit); extern mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name); extern mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease); extern mDNSu8 *putUpdateLeaseWithLimit(DNSMessage *msg, mDNSu8 *ptr, mDNSu32 lease, mDNSu8 *limit); extern int baseEncode(char *buffer, int blen, const mDNSu8 *data, int len, int encAlg); extern void NSEC3Parse(const ResourceRecord *const rr, mDNSu8 **salt, int *hashLength, mDNSu8 **nxtName, int *bitmaplen, mDNSu8 **bitmap); // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNS Message Parsing Functions #endif #define HashSlotFromNameHash(X) ((X) % CACHE_HASH_SLOTS) extern mDNSu32 DomainNameHashValue(const domainname *const name); extern void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength); extern const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end); extern const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, domainname *const name); extern const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end); extern const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage * const msg, const mDNSu8 *ptr, const mDNSu8 * end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr); extern mDNSBool SetRData(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *end, ResourceRecord *rr, mDNSu16 rdlength); extern const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end); extern const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID, DNSQuestion *question); extern const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end); extern const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end); extern const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end); extern const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize); extern const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end); extern mDNSBool GetPktLease(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, mDNSu32 *const lease); extern void DumpPacket(mStatus status, mDNSBool sent, const char *transport, const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end, mDNSInterfaceID interfaceID); extern mDNSBool RRAssertsNonexistence(const ResourceRecord *const rr, mDNSu16 type); extern mDNSBool RRAssertsExistence(const ResourceRecord *const rr, mDNSu16 type); extern mDNSBool BitmapTypeCheck(mDNSu8 *bmap, int bitmaplen, mDNSu16 type); extern mDNSu16 swap16(mDNSu16 x); extern mDNSu32 swap32(mDNSu32 x); extern mDNSBool GetReverseIPv6Addr(const domainname *inQName, mDNSu8 outIPv6[16]); // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Packet Sending Functions #endif extern mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end, mDNSInterfaceID InterfaceID, TCPSocket *tcpSrc, UDPSocket *udpSrc, const mDNSAddr *dst, mDNSIPPort dstport, DomainAuthInfo *authInfo, mDNSBool useBackgroundTrafficClass); // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - RR List Management & Task Management #endif extern void ShowTaskSchedulingError(mDNS *const m); extern void mDNS_Lock_(mDNS *const m, const char * const functionname); extern void mDNS_Unlock_(mDNS *const m, const char * const functionname); #if defined(_WIN32) #define __func__ __FUNCTION__ #endif #define mDNS_Lock(X) mDNS_Lock_((X), __func__) #define mDNS_Unlock(X) mDNS_Unlock_((X), __func__) #define mDNS_CheckLock(X) \ if ((X)->mDNS_busy != (X)->mDNS_reentrancy+1) LogMsg("%s: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", __func__, (X)->mDNS_busy, (X)->mDNS_reentrancy) #define mDNS_DropLockBeforeCallback() do { m->mDNS_reentrancy++; \ if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Locking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \ } while (0) #define mDNS_ReclaimLockAfterCallback() do { \ if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("%s: Unlocking Failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", __func__, m->mDNS_busy, m->mDNS_reentrancy); \ m->mDNS_reentrancy--; } while (0) #ifdef __cplusplus } #endif #endif // __DNSCOMMON_H_ /* * Copyright (c) 2002-2019 Apple Inc. All rights reserved. * Copyright (c) 2016 by Delphix. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifdef __cplusplus extern "C" { #endif #include "mDNSEmbeddedAPI.h" #include "DNSCommon.h" // Disable certain benign warnings with Microsoft compilers #if (defined(_MSC_VER)) // Disable "conditional expression is constant" warning for debug macros. // Otherwise, this generates warnings for the perfectly natural construct "while(1)" // If someone knows a variant way of writing "while(1)" that doesn't generate warning messages, please let us know #pragma warning(disable:4127) #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Byte Swapping Functions #endif mDNSlocal mDNSu16 NToH16(mDNSu8 * bytes) { return (mDNSu16)((mDNSu16)bytes[0] << 8 | (mDNSu16)bytes[1]); } mDNSlocal mDNSu32 NToH32(mDNSu8 * bytes) { return (mDNSu32)((mDNSu32) bytes[0] << 24 | (mDNSu32) bytes[1] << 16 | (mDNSu32) bytes[2] << 8 | (mDNSu32)bytes[3]); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - MD5 Hash Functions #endif /* The source for the has is derived CommonCrypto files CommonDigest.h, md32_common.h, md5_locl.h, md5_locl.h, and openssl/md5.h. * The following changes have been made to the original sources: * replaced CC_LONG w/ mDNSu32 * replaced CC_MD5* with MD5* * replaced CC_LONG w/ mDNSu32, removed conditional #defines from md5.h * removed extern decls for MD5_Init/Update/Final from CommonDigest.h * removed APPLE_COMMON_DIGEST specific #defines from md5_locl.h * * Note: machine archetecure specific conditionals from the original sources are turned off, but are left in the code * to aid in platform-specific optimizations and debugging. * Sources originally distributed under the following license headers: * CommonDigest.h - APSL * * md32_Common.h * ==================================================================== * Copyright (c) 1999-2002 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * * * md5_dgst.c, md5_locl.h * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * * Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] * */ //from CommonDigest.h // from openssl/md5.h #define MD5_CBLOCK 64 #define MD5_LBLOCK (MD5_CBLOCK/4) #define MD5_DIGEST_LENGTH 16 void MD5_Transform(MD5_CTX *c, const unsigned char *b); // From md5_locl.h #ifndef MD5_LONG_LOG2 #define MD5_LONG_LOG2 2 /* default to 32 bits */ #endif #ifdef MD5_ASM # if defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(__INTEL__) # define md5_block_host_order md5_block_asm_host_order # elif defined(__sparc) && defined(OPENSSL_SYS_ULTRASPARC) void md5_block_asm_data_order_aligned (MD5_CTX *c, const mDNSu32 *p,int num); # define HASH_BLOCK_DATA_ORDER_ALIGNED md5_block_asm_data_order_aligned # endif #endif void md5_block_host_order (MD5_CTX *c, const void *p,int num); void md5_block_data_order (MD5_CTX *c, const void *p,int num); #if defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(__INTEL__) /* * *_block_host_order is expected to handle aligned data while * *_block_data_order - unaligned. As algorithm and host (x86) * are in this case of the same "endianness" these two are * otherwise indistinguishable. But normally you don't want to * call the same function because unaligned access in places * where alignment is expected is usually a "Bad Thing". Indeed, * on RISCs you get punished with BUS ERROR signal or *severe* * performance degradation. Intel CPUs are in turn perfectly * capable of loading unaligned data without such drastic side * effect. Yes, they say it's slower than aligned load, but no * exception is generated and therefore performance degradation * is *incomparable* with RISCs. What we should weight here is * costs of unaligned access against costs of aligning data. * According to my measurements allowing unaligned access results * in ~9% performance improvement on Pentium II operating at * 266MHz. I won't be surprised if the difference will be higher * on faster systems:-) * * */ #define md5_block_data_order md5_block_host_order #endif #define DATA_ORDER_IS_LITTLE_ENDIAN #define HASH_LONG mDNSu32 #define HASH_LONG_LOG2 MD5_LONG_LOG2 #define HASH_CTX MD5_CTX #define HASH_CBLOCK MD5_CBLOCK #define HASH_LBLOCK MD5_LBLOCK #define HASH_UPDATE MD5_Update #define HASH_TRANSFORM MD5_Transform #define HASH_FINAL MD5_Final #define HASH_MAKE_STRING(c,s) do { \ unsigned long ll; \ ll=(c)->A; HOST_l2c(ll,(s)); \ ll=(c)->B; HOST_l2c(ll,(s)); \ ll=(c)->C; HOST_l2c(ll,(s)); \ ll=(c)->D; HOST_l2c(ll,(s)); \ } while (0) #define HASH_BLOCK_HOST_ORDER md5_block_host_order #if !defined(L_ENDIAN) || defined(md5_block_data_order) #define HASH_BLOCK_DATA_ORDER md5_block_data_order /* * Little-endians (Intel and Alpha) feel better without this. * It looks like memcpy does better job than generic * md5_block_data_order on copying-n-aligning input data. * But frankly speaking I didn't expect such result on Alpha. * On the other hand I've got this with egcs-1.0.2 and if * program is compiled with another (better?) compiler it * might turn out other way around. * * */ #endif // from md32_common.h /* * This is a generic 32 bit "collector" for message digest algorithms. * Whenever needed it collects input character stream into chunks of * 32 bit values and invokes a block function that performs actual hash * calculations. * * Porting guide. * * Obligatory macros: * * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN * this macro defines byte order of input stream. * HASH_CBLOCK * size of a unit chunk HASH_BLOCK operates on. * HASH_LONG * has to be at lest 32 bit wide, if it's wider, then * HASH_LONG_LOG2 *has to* be defined along * HASH_CTX * context structure that at least contains following * members: * typedef struct { * ... * HASH_LONG Nl,Nh; * HASH_LONG data[HASH_LBLOCK]; * int num; * ... * } HASH_CTX; * HASH_UPDATE * name of "Update" function, implemented here. * HASH_TRANSFORM * name of "Transform" function, implemented here. * HASH_FINAL * name of "Final" function, implemented here. * HASH_BLOCK_HOST_ORDER * name of "block" function treating *aligned* input message * in host byte order, implemented externally. * HASH_BLOCK_DATA_ORDER * name of "block" function treating *unaligned* input message * in original (data) byte order, implemented externally (it * actually is optional if data and host are of the same * "endianess"). * HASH_MAKE_STRING * macro convering context variables to an ASCII hash string. * * Optional macros: * * B_ENDIAN or L_ENDIAN * defines host byte-order. * HASH_LONG_LOG2 * defaults to 2 if not states otherwise. * HASH_LBLOCK * assumed to be HASH_CBLOCK/4 if not stated otherwise. * HASH_BLOCK_DATA_ORDER_ALIGNED * alternative "block" function capable of treating * aligned input message in original (data) order, * implemented externally. * * MD5 example: * * #define DATA_ORDER_IS_LITTLE_ENDIAN * * #define HASH_LONG mDNSu32 * #define HASH_LONG_LOG2 mDNSu32_LOG2 * #define HASH_CTX MD5_CTX * #define HASH_CBLOCK MD5_CBLOCK * #define HASH_LBLOCK MD5_LBLOCK * #define HASH_UPDATE MD5_Update * #define HASH_TRANSFORM MD5_Transform * #define HASH_FINAL MD5_Final * #define HASH_BLOCK_HOST_ORDER md5_block_host_order * #define HASH_BLOCK_DATA_ORDER md5_block_data_order * * */ #if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN) #error "DATA_ORDER must be defined!" #endif #ifndef HASH_CBLOCK #error "HASH_CBLOCK must be defined!" #endif #ifndef HASH_LONG #error "HASH_LONG must be defined!" #endif #ifndef HASH_CTX #error "HASH_CTX must be defined!" #endif #ifndef HASH_UPDATE #error "HASH_UPDATE must be defined!" #endif #ifndef HASH_TRANSFORM #error "HASH_TRANSFORM must be defined!" #endif #ifndef HASH_FINAL #error "HASH_FINAL must be defined!" #endif #ifndef HASH_BLOCK_HOST_ORDER #error "HASH_BLOCK_HOST_ORDER must be defined!" #endif #if 0 /* * Moved below as it's required only if HASH_BLOCK_DATA_ORDER_ALIGNED * isn't defined. */ #ifndef HASH_BLOCK_DATA_ORDER #error "HASH_BLOCK_DATA_ORDER must be defined!" #endif #endif #ifndef HASH_LBLOCK #define HASH_LBLOCK (HASH_CBLOCK/4) #endif #ifndef HASH_LONG_LOG2 #define HASH_LONG_LOG2 2 #endif /* * Engage compiler specific rotate intrinsic function if available. */ #undef ROTATE #ifndef PEDANTIC # if 0 /* defined(_MSC_VER) */ # define ROTATE(a,n) _lrotl(a,n) # elif defined(__MWERKS__) # if defined(__POWERPC__) # define ROTATE(a,n) (unsigned MD32_REG_T)__rlwinm((int)a,n,0,31) # elif defined(__MC68K__) /* Motorola specific tweak. */ # define ROTATE(a,n) (n<24 ? __rol(a,n) : __ror(a,32-n)) # else # define ROTATE(a,n) __rol(a,n) # endif # elif defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) /* * Some GNU C inline assembler templates. Note that these are * rotates by *constant* number of bits! But that's exactly * what we need here... * * */ /* * LLVM is more strict about compatibility of types between input & output constraints, * but we want these to be rotations of 32 bits, not 64, so we explicitly drop the * most significant bytes by casting to an unsigned int. */ # if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__) # define ROTATE(a,n) ({ register unsigned int ret; \ asm ( \ "roll %1,%0" \ : "=r" (ret) \ : "I" (n), "0" ((unsigned int)a) \ : "cc"); \ ret; \ }) # elif defined(__powerpc) || defined(__ppc) # define ROTATE(a,n) ({ register unsigned int ret; \ asm ( \ "rlwinm %0,%1,%2,0,31" \ : "=r" (ret) \ : "r" (a), "I" (n)); \ ret; \ }) # endif # endif /* * Engage compiler specific "fetch in reverse byte order" * intrinsic function if available. */ # if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) /* some GNU C inline assembler templates by */ # if (defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)) && !defined(I386_ONLY) # define BE_FETCH32(a) ({ register unsigned int l=(a); \ asm ( \ "bswapl %0" \ : "=r" (l) : "0" (l)); \ l; \ }) # elif defined(__powerpc) # define LE_FETCH32(a) ({ register unsigned int l; \ asm ( \ "lwbrx %0,0,%1" \ : "=r" (l) \ : "r" (a)); \ l; \ }) # elif defined(__sparc) && defined(OPENSSL_SYS_ULTRASPARC) # define LE_FETCH32(a) ({ register unsigned int l; \ asm ( \ "lda [%1]#ASI_PRIMARY_LITTLE,%0" \ : "=r" (l) \ : "r" (a)); \ l; \ }) # endif # endif #endif /* PEDANTIC */ #if HASH_LONG_LOG2==2 /* Engage only if sizeof(HASH_LONG)== 4 */ /* A nice byte order reversal from Wei Dai */ #ifdef ROTATE /* 5 instructions with rotate instruction, else 9 */ #define REVERSE_FETCH32(a,l) ( \ l=*(const HASH_LONG *)(a), \ ((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24))) \ ) #else /* 6 instructions with rotate instruction, else 8 */ #define REVERSE_FETCH32(a,l) ( \ l=*(const HASH_LONG *)(a), \ l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)), \ ROTATE(l,16) \ ) /* * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|... * It's rewritten as above for two reasons: * - RISCs aren't good at long constants and have to explicitely * compose 'em with several (well, usually 2) instructions in a * register before performing the actual operation and (as you * already realized:-) having same constant should inspire the * compiler to permanently allocate the only register for it; * - most modern CPUs have two ALUs, but usually only one has * circuitry for shifts:-( this minor tweak inspires compiler * to schedule shift instructions in a better way... * * */ #endif #endif #ifndef ROTATE #define ROTATE(a,n) (((a)<<(n))|(((a)&0xffffffff)>>(32-(n)))) #endif /* * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED * and HASH_BLOCK_HOST_ORDER ought to be the same if input data * and host are of the same "endianess". It's possible to mask * this with blank #define HASH_BLOCK_DATA_ORDER though... * * */ #if defined(B_ENDIAN) # if defined(DATA_ORDER_IS_BIG_ENDIAN) # if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2 # define HASH_BLOCK_DATA_ORDER_ALIGNED HASH_BLOCK_HOST_ORDER # endif # elif defined(DATA_ORDER_IS_LITTLE_ENDIAN) # ifndef HOST_FETCH32 # ifdef LE_FETCH32 # define HOST_FETCH32(p,l) LE_FETCH32(p) # elif defined(REVERSE_FETCH32) # define HOST_FETCH32(p,l) REVERSE_FETCH32(p,l) # endif # endif # endif #elif defined(L_ENDIAN) # if defined(DATA_ORDER_IS_LITTLE_ENDIAN) # if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2 # define HASH_BLOCK_DATA_ORDER_ALIGNED HASH_BLOCK_HOST_ORDER # endif # elif defined(DATA_ORDER_IS_BIG_ENDIAN) # ifndef HOST_FETCH32 # ifdef BE_FETCH32 # define HOST_FETCH32(p,l) BE_FETCH32(p) # elif defined(REVERSE_FETCH32) # define HOST_FETCH32(p,l) REVERSE_FETCH32(p,l) # endif # endif # endif #endif #if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) #ifndef HASH_BLOCK_DATA_ORDER #error "HASH_BLOCK_DATA_ORDER must be defined!" #endif #endif // None of the invocations of the following macros actually use the result, // so cast them to void to avoid any compiler warnings/errors about not using // the result (e.g. when using clang). // If the resultant values need to be used at some point, these must be changed. #define HOST_c2l(c,l) ((void)_HOST_c2l(c,l)) #define HOST_l2c(l,c) ((void)_HOST_l2c(l,c)) #if defined(DATA_ORDER_IS_BIG_ENDIAN) #define _HOST_c2l(c,l) (l =(((unsigned long)(*((c)++)))<<24), \ l|=(((unsigned long)(*((c)++)))<<16), \ l|=(((unsigned long)(*((c)++)))<< 8), \ l|=(((unsigned long)(*((c)++))) ), \ l) #define HOST_p_c2l(c,l,n) { \ switch (n) { \ case 0: l =((unsigned long)(*((c)++)))<<24; \ /* FALLTHROUGH */ \ case 1: l|=((unsigned long)(*((c)++)))<<16; \ /* FALLTHROUGH */ \ case 2: l|=((unsigned long)(*((c)++)))<< 8; \ /* FALLTHROUGH */ \ case 3: l|=((unsigned long)(*((c)++))); \ } } #define HOST_p_c2l_p(c,l,sc,len) { \ switch (sc) { \ case 0: l =((unsigned long)(*((c)++)))<<24; \ if (--len == 0) break; \ /* FALLTHROUGH */ \ case 1: l|=((unsigned long)(*((c)++)))<<16; \ if (--len == 0) break; \ /* FALLTHROUGH */ \ case 2: l|=((unsigned long)(*((c)++)))<< 8; \ } } /* NOTE the pointer is not incremented at the end of this */ #define HOST_c2l_p(c,l,n) { \ l=0; (c)+=n; \ switch (n) { \ case 3: l =((unsigned long)(*(--(c))))<< 8; \ /* FALLTHROUGH */ \ case 2: l|=((unsigned long)(*(--(c))))<<16; \ /* FALLTHROUGH */ \ case 1: l|=((unsigned long)(*(--(c))))<<24; \ } } #define _HOST_l2c(l,c) (*((c)++)=(unsigned char)(((l)>>24)&0xff), \ *((c)++)=(unsigned char)(((l)>>16)&0xff), \ *((c)++)=(unsigned char)(((l)>> 8)&0xff), \ *((c)++)=(unsigned char)(((l) )&0xff), \ l) #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN) #define _HOST_c2l(c,l) (l =(((unsigned long)(*((c)++))) ), \ l|=(((unsigned long)(*((c)++)))<< 8), \ l|=(((unsigned long)(*((c)++)))<<16), \ l|=(((unsigned long)(*((c)++)))<<24), \ l) #define HOST_p_c2l(c,l,n) { \ switch (n) { \ case 0: l =((unsigned long)(*((c)++))); \ /* FALLTHROUGH */ \ case 1: l|=((unsigned long)(*((c)++)))<< 8; \ /* FALLTHROUGH */ \ case 2: l|=((unsigned long)(*((c)++)))<<16; \ /* FALLTHROUGH */ \ case 3: l|=((unsigned long)(*((c)++)))<<24; \ } } #define HOST_p_c2l_p(c,l,sc,len) { \ switch (sc) { \ case 0: l =((unsigned long)(*((c)++))); \ if (--len == 0) break; \ /* FALLTHROUGH */ \ case 1: l|=((unsigned long)(*((c)++)))<< 8; \ if (--len == 0) break; \ /* FALLTHROUGH */ \ case 2: l|=((unsigned long)(*((c)++)))<<16; \ } } /* NOTE the pointer is not incremented at the end of this */ #define HOST_c2l_p(c,l,n) { \ l=0; (c)+=n; \ switch (n) { \ case 3: l =((unsigned long)(*(--(c))))<<16; \ /* FALLTHROUGH */ \ case 2: l|=((unsigned long)(*(--(c))))<< 8; \ /* FALLTHROUGH */ \ case 1: l|=((unsigned long)(*(--(c)))); \ } } #define _HOST_l2c(l,c) (*((c)++)=(unsigned char)(((l) )&0xff), \ *((c)++)=(unsigned char)(((l)>> 8)&0xff), \ *((c)++)=(unsigned char)(((l)>>16)&0xff), \ *((c)++)=(unsigned char)(((l)>>24)&0xff), \ l) #endif /* * Time for some action:-) */ int HASH_UPDATE (HASH_CTX *c, const void *data_, unsigned long len) { const unsigned char *data=(const unsigned char *)data_; const unsigned char * const data_end=(const unsigned char *)data_; register HASH_LONG * p; register unsigned long l; int sw,sc,ew,ec; if (len==0) return 1; l=(c->Nl+(len<<3))&0xffffffffL; /* 95-05-24 eay Fixed a bug with the overflow handling, thanks to * Wei Dai for pointing it out. */ if (l < c->Nl) /* overflow */ c->Nh++; c->Nh+=(len>>29); c->Nl=l; if (c->num != 0) { p=c->data; sw=c->num>>2; sc=c->num&0x03; if ((c->num+len) >= HASH_CBLOCK) { l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l; for (; (sw < HASH_LBLOCK) && ((data_end - data) >= 4); sw++) { HOST_c2l(data,l); p[sw]=l; } HASH_BLOCK_HOST_ORDER (c,p,1); len-=(HASH_CBLOCK-c->num); c->num=0; /* drop through and do the rest */ } else { c->num+=len; if ((sc+len) < 4) /* ugly, add char's to a word */ { l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l; } else { ew=(c->num>>2); ec=(c->num&0x03); if (sc) l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l; for (; (sw < ew) && ((data_end - data) >= 4); sw++) { HOST_c2l(data,l); p[sw]=l; } if (ec) { HOST_c2l_p(data,l,ec); p[sw]=l; } } return 1; } } sw=(int)(len/HASH_CBLOCK); if (sw > 0) { #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED) /* * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined * only if sizeof(HASH_LONG)==4. */ if ((((unsigned long)data)%4) == 0) { /* data is properly aligned so that we can cast it: */ HASH_BLOCK_DATA_ORDER_ALIGNED (c,(HASH_LONG *)data,sw); sw*=HASH_CBLOCK; data+=sw; len-=sw; } else #if !defined(HASH_BLOCK_DATA_ORDER) while (sw--) { mDNSPlatformMemCopy(p=c->data,data,HASH_CBLOCK); HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1); data+=HASH_CBLOCK; len-=HASH_CBLOCK; } #endif #endif #if defined(HASH_BLOCK_DATA_ORDER) { HASH_BLOCK_DATA_ORDER(c,data,sw); sw*=HASH_CBLOCK; data+=sw; len-=sw; } #endif } if (len!=0) { p = c->data; c->num = (int)len; ew=(int)(len>>2); /* words to copy */ ec=(int)(len&0x03); for (; ew && ((data_end - data) >= 4); ew--,p++) { HOST_c2l(data,l); *p=l; } HOST_c2l_p(data,l,ec); *p=l; } return 1; } void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data) { #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED) if ((((unsigned long)data)%4) == 0) /* data is properly aligned so that we can cast it: */ HASH_BLOCK_DATA_ORDER_ALIGNED (c,(HASH_LONG *)data,1); else #if !defined(HASH_BLOCK_DATA_ORDER) { mDNSPlatformMemCopy(c->data,data,HASH_CBLOCK); HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1); } #endif #endif #if defined(HASH_BLOCK_DATA_ORDER) HASH_BLOCK_DATA_ORDER (c,data,1); #endif } int HASH_FINAL (unsigned char *md, HASH_CTX *c) { register HASH_LONG *p; register unsigned long l; register int i,j; static const unsigned char end[4]={0x80,0x00,0x00,0x00}; const unsigned char *cp=end; /* c->num should definitly have room for at least one more byte. */ p=c->data; i=c->num>>2; j=c->num&0x03; #if 0 /* purify often complains about the following line as an * Uninitialized Memory Read. While this can be true, the * following p_c2l macro will reset l when that case is true. * This is because j&0x03 contains the number of 'valid' bytes * already in p[i]. If and only if j&0x03 == 0, the UMR will * occur but this is also the only time p_c2l will do * l= *(cp++) instead of l|= *(cp++) * Many thanks to Alex Tang for pickup this * 'potential bug' */ #ifdef PURIFY if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */ #endif l=p[i]; #else l = (j==0) ? 0 : p[i]; #endif HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */ if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */ { if (iNh; p[HASH_LBLOCK-1]=c->Nl; #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN) p[HASH_LBLOCK-2]=c->Nl; p[HASH_LBLOCK-1]=c->Nh; #endif HASH_BLOCK_HOST_ORDER (c,p,1); #ifndef HASH_MAKE_STRING #error "HASH_MAKE_STRING must be defined!" #else HASH_MAKE_STRING(c,md); #endif c->num=0; /* clear stuff, HASH_BLOCK may be leaving some stuff on the stack * but I'm not worried :-) OPENSSL_cleanse((void *)c,sizeof(HASH_CTX)); */ return 1; } #ifndef MD32_REG_T #define MD32_REG_T long /* * This comment was originaly written for MD5, which is why it * discusses A-D. But it basically applies to all 32-bit digests, * which is why it was moved to common header file. * * In case you wonder why A-D are declared as long and not * as mDNSu32. Doing so results in slight performance * boost on LP64 architectures. The catch is we don't * really care if 32 MSBs of a 64-bit register get polluted * with eventual overflows as we *save* only 32 LSBs in * *either* case. Now declaring 'em long excuses the compiler * from keeping 32 MSBs zeroed resulting in 13% performance * improvement under SPARC Solaris7/64 and 5% under AlphaLinux. * Well, to be honest it should say that this *prevents* * performance degradation. * * Apparently there're LP64 compilers that generate better * code if A-D are declared int. Most notably GCC-x86_64 * generates better code. * */ #endif // from md5_locl.h (continued) /* #define F(x,y,z) (((x) & (y)) | ((~(x)) & (z))) #define G(x,y,z) (((x) & (z)) | ((y) & (~(z)))) */ /* As pointed out by Wei Dai , the above can be * simplified to the code below. Wei attributes these optimizations * to Peter Gutmann's SHS code, and he attributes it to Rich Schroeppel. */ #define F(b,c,d) ((((c) ^ (d)) & (b)) ^ (d)) #define G(b,c,d) ((((b) ^ (c)) & (d)) ^ (c)) #define H(b,c,d) ((b) ^ (c) ^ (d)) #define I(b,c,d) (((~(d)) | (b)) ^ (c)) #define R0(a,b,c,d,k,s,t) { \ a+=((k)+(t)+F((b),(c),(d))); \ a=ROTATE(a,s); \ a+=b; }; \ #define R1(a,b,c,d,k,s,t) { \ a+=((k)+(t)+G((b),(c),(d))); \ a=ROTATE(a,s); \ a+=b; }; #define R2(a,b,c,d,k,s,t) { \ a+=((k)+(t)+H((b),(c),(d))); \ a=ROTATE(a,s); \ a+=b; }; #define R3(a,b,c,d,k,s,t) { \ a+=((k)+(t)+I((b),(c),(d))); \ a=ROTATE(a,s); \ a+=b; }; // from md5_dgst.c /* Implemented from RFC1321 The MD5 Message-Digest Algorithm */ #define INIT_DATA_A (unsigned long)0x67452301L #define INIT_DATA_B (unsigned long)0xefcdab89L #define INIT_DATA_C (unsigned long)0x98badcfeL #define INIT_DATA_D (unsigned long)0x10325476L int MD5_Init(MD5_CTX *c) { c->A=INIT_DATA_A; c->B=INIT_DATA_B; c->C=INIT_DATA_C; c->D=INIT_DATA_D; c->Nl=0; c->Nh=0; c->num=0; return 1; } #ifndef md5_block_host_order void md5_block_host_order (MD5_CTX *c, const void *data, int num) { const mDNSu32 *X=(const mDNSu32 *)data; register unsigned MD32_REG_T A,B,C,D; A=c->A; B=c->B; C=c->C; D=c->D; for (; num--; X+=HASH_LBLOCK) { /* Round 0 */ R0(A,B,C,D,X[ 0], 7,0xd76aa478L); R0(D,A,B,C,X[ 1],12,0xe8c7b756L); R0(C,D,A,B,X[ 2],17,0x242070dbL); R0(B,C,D,A,X[ 3],22,0xc1bdceeeL); R0(A,B,C,D,X[ 4], 7,0xf57c0fafL); R0(D,A,B,C,X[ 5],12,0x4787c62aL); R0(C,D,A,B,X[ 6],17,0xa8304613L); R0(B,C,D,A,X[ 7],22,0xfd469501L); R0(A,B,C,D,X[ 8], 7,0x698098d8L); R0(D,A,B,C,X[ 9],12,0x8b44f7afL); R0(C,D,A,B,X[10],17,0xffff5bb1L); R0(B,C,D,A,X[11],22,0x895cd7beL); R0(A,B,C,D,X[12], 7,0x6b901122L); R0(D,A,B,C,X[13],12,0xfd987193L); R0(C,D,A,B,X[14],17,0xa679438eL); R0(B,C,D,A,X[15],22,0x49b40821L); /* Round 1 */ R1(A,B,C,D,X[ 1], 5,0xf61e2562L); R1(D,A,B,C,X[ 6], 9,0xc040b340L); R1(C,D,A,B,X[11],14,0x265e5a51L); R1(B,C,D,A,X[ 0],20,0xe9b6c7aaL); R1(A,B,C,D,X[ 5], 5,0xd62f105dL); R1(D,A,B,C,X[10], 9,0x02441453L); R1(C,D,A,B,X[15],14,0xd8a1e681L); R1(B,C,D,A,X[ 4],20,0xe7d3fbc8L); R1(A,B,C,D,X[ 9], 5,0x21e1cde6L); R1(D,A,B,C,X[14], 9,0xc33707d6L); R1(C,D,A,B,X[ 3],14,0xf4d50d87L); R1(B,C,D,A,X[ 8],20,0x455a14edL); R1(A,B,C,D,X[13], 5,0xa9e3e905L); R1(D,A,B,C,X[ 2], 9,0xfcefa3f8L); R1(C,D,A,B,X[ 7],14,0x676f02d9L); R1(B,C,D,A,X[12],20,0x8d2a4c8aL); /* Round 2 */ R2(A,B,C,D,X[ 5], 4,0xfffa3942L); R2(D,A,B,C,X[ 8],11,0x8771f681L); R2(C,D,A,B,X[11],16,0x6d9d6122L); R2(B,C,D,A,X[14],23,0xfde5380cL); R2(A,B,C,D,X[ 1], 4,0xa4beea44L); R2(D,A,B,C,X[ 4],11,0x4bdecfa9L); R2(C,D,A,B,X[ 7],16,0xf6bb4b60L); R2(B,C,D,A,X[10],23,0xbebfbc70L); R2(A,B,C,D,X[13], 4,0x289b7ec6L); R2(D,A,B,C,X[ 0],11,0xeaa127faL); R2(C,D,A,B,X[ 3],16,0xd4ef3085L); R2(B,C,D,A,X[ 6],23,0x04881d05L); R2(A,B,C,D,X[ 9], 4,0xd9d4d039L); R2(D,A,B,C,X[12],11,0xe6db99e5L); R2(C,D,A,B,X[15],16,0x1fa27cf8L); R2(B,C,D,A,X[ 2],23,0xc4ac5665L); /* Round 3 */ R3(A,B,C,D,X[ 0], 6,0xf4292244L); R3(D,A,B,C,X[ 7],10,0x432aff97L); R3(C,D,A,B,X[14],15,0xab9423a7L); R3(B,C,D,A,X[ 5],21,0xfc93a039L); R3(A,B,C,D,X[12], 6,0x655b59c3L); R3(D,A,B,C,X[ 3],10,0x8f0ccc92L); R3(C,D,A,B,X[10],15,0xffeff47dL); R3(B,C,D,A,X[ 1],21,0x85845dd1L); R3(A,B,C,D,X[ 8], 6,0x6fa87e4fL); R3(D,A,B,C,X[15],10,0xfe2ce6e0L); R3(C,D,A,B,X[ 6],15,0xa3014314L); R3(B,C,D,A,X[13],21,0x4e0811a1L); R3(A,B,C,D,X[ 4], 6,0xf7537e82L); R3(D,A,B,C,X[11],10,0xbd3af235L); R3(C,D,A,B,X[ 2],15,0x2ad7d2bbL); R3(B,C,D,A,X[ 9],21,0xeb86d391L); A = c->A += A; B = c->B += B; C = c->C += C; D = c->D += D; } } #endif #ifndef md5_block_data_order #ifdef X #undef X #endif void md5_block_data_order (MD5_CTX *c, const void *data_, int num) { const unsigned char *data=data_; register unsigned MD32_REG_T A,B,C,D,l; #ifndef MD32_XARRAY /* See comment in crypto/sha/sha_locl.h for details. */ unsigned MD32_REG_T XX0, XX1, XX2, XX3, XX4, XX5, XX6, XX7, XX8, XX9,XX10,XX11,XX12,XX13,XX14,XX15; # define X(i) XX ## i #else mDNSu32 XX[MD5_LBLOCK]; # define X(i) XX[i] #endif A=c->A; B=c->B; C=c->C; D=c->D; #if defined(__clang_analyzer__) // Get rid of false positive analyzer warning. for (const unsigned char *_ptr = data; _ptr < &data[num * HASH_CBLOCK]; ++_ptr) {} #endif for (; num--;) { HOST_c2l(data,l); X( 0)=l; HOST_c2l(data,l); X( 1)=l; /* Round 0 */ R0(A,B,C,D,X( 0), 7,0xd76aa478L); HOST_c2l(data,l); X( 2)=l; R0(D,A,B,C,X( 1),12,0xe8c7b756L); HOST_c2l(data,l); X( 3)=l; R0(C,D,A,B,X( 2),17,0x242070dbL); HOST_c2l(data,l); X( 4)=l; R0(B,C,D,A,X( 3),22,0xc1bdceeeL); HOST_c2l(data,l); X( 5)=l; R0(A,B,C,D,X( 4), 7,0xf57c0fafL); HOST_c2l(data,l); X( 6)=l; R0(D,A,B,C,X( 5),12,0x4787c62aL); HOST_c2l(data,l); X( 7)=l; R0(C,D,A,B,X( 6),17,0xa8304613L); HOST_c2l(data,l); X( 8)=l; R0(B,C,D,A,X( 7),22,0xfd469501L); HOST_c2l(data,l); X( 9)=l; R0(A,B,C,D,X( 8), 7,0x698098d8L); HOST_c2l(data,l); X(10)=l; R0(D,A,B,C,X( 9),12,0x8b44f7afL); HOST_c2l(data,l); X(11)=l; R0(C,D,A,B,X(10),17,0xffff5bb1L); HOST_c2l(data,l); X(12)=l; R0(B,C,D,A,X(11),22,0x895cd7beL); HOST_c2l(data,l); X(13)=l; R0(A,B,C,D,X(12), 7,0x6b901122L); HOST_c2l(data,l); X(14)=l; R0(D,A,B,C,X(13),12,0xfd987193L); HOST_c2l(data,l); X(15)=l; R0(C,D,A,B,X(14),17,0xa679438eL); R0(B,C,D,A,X(15),22,0x49b40821L); /* Round 1 */ R1(A,B,C,D,X( 1), 5,0xf61e2562L); R1(D,A,B,C,X( 6), 9,0xc040b340L); R1(C,D,A,B,X(11),14,0x265e5a51L); R1(B,C,D,A,X( 0),20,0xe9b6c7aaL); R1(A,B,C,D,X( 5), 5,0xd62f105dL); R1(D,A,B,C,X(10), 9,0x02441453L); R1(C,D,A,B,X(15),14,0xd8a1e681L); R1(B,C,D,A,X( 4),20,0xe7d3fbc8L); R1(A,B,C,D,X( 9), 5,0x21e1cde6L); R1(D,A,B,C,X(14), 9,0xc33707d6L); R1(C,D,A,B,X( 3),14,0xf4d50d87L); R1(B,C,D,A,X( 8),20,0x455a14edL); R1(A,B,C,D,X(13), 5,0xa9e3e905L); R1(D,A,B,C,X( 2), 9,0xfcefa3f8L); R1(C,D,A,B,X( 7),14,0x676f02d9L); R1(B,C,D,A,X(12),20,0x8d2a4c8aL); /* Round 2 */ R2(A,B,C,D,X( 5), 4,0xfffa3942L); R2(D,A,B,C,X( 8),11,0x8771f681L); R2(C,D,A,B,X(11),16,0x6d9d6122L); R2(B,C,D,A,X(14),23,0xfde5380cL); R2(A,B,C,D,X( 1), 4,0xa4beea44L); R2(D,A,B,C,X( 4),11,0x4bdecfa9L); R2(C,D,A,B,X( 7),16,0xf6bb4b60L); R2(B,C,D,A,X(10),23,0xbebfbc70L); R2(A,B,C,D,X(13), 4,0x289b7ec6L); R2(D,A,B,C,X( 0),11,0xeaa127faL); R2(C,D,A,B,X( 3),16,0xd4ef3085L); R2(B,C,D,A,X( 6),23,0x04881d05L); R2(A,B,C,D,X( 9), 4,0xd9d4d039L); R2(D,A,B,C,X(12),11,0xe6db99e5L); R2(C,D,A,B,X(15),16,0x1fa27cf8L); R2(B,C,D,A,X( 2),23,0xc4ac5665L); /* Round 3 */ R3(A,B,C,D,X( 0), 6,0xf4292244L); R3(D,A,B,C,X( 7),10,0x432aff97L); R3(C,D,A,B,X(14),15,0xab9423a7L); R3(B,C,D,A,X( 5),21,0xfc93a039L); R3(A,B,C,D,X(12), 6,0x655b59c3L); R3(D,A,B,C,X( 3),10,0x8f0ccc92L); R3(C,D,A,B,X(10),15,0xffeff47dL); R3(B,C,D,A,X( 1),21,0x85845dd1L); R3(A,B,C,D,X( 8), 6,0x6fa87e4fL); R3(D,A,B,C,X(15),10,0xfe2ce6e0L); R3(C,D,A,B,X( 6),15,0xa3014314L); R3(B,C,D,A,X(13),21,0x4e0811a1L); R3(A,B,C,D,X( 4), 6,0xf7537e82L); R3(D,A,B,C,X(11),10,0xbd3af235L); R3(C,D,A,B,X( 2),15,0x2ad7d2bbL); R3(B,C,D,A,X( 9),21,0xeb86d391L); A = c->A += A; B = c->B += B; C = c->C += C; D = c->D += D; } } #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - base64 -> binary conversion #endif static const char Base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; static const char Pad64 = '='; #define mDNSisspace(x) (x == '\t' || x == '\n' || x == '\v' || x == '\f' || x == '\r' || x == ' ') mDNSlocal const char *mDNSstrchr(const char *s, int c) { while (1) { if (c == *s) return s; if (!*s) return mDNSNULL; s++; } } // skips all whitespace anywhere. // converts characters, four at a time, starting at (or after) // src from base - 64 numbers into three 8 bit bytes in the target area. // it returns the number of data bytes stored at the target, or -1 on error. // adapted from BIND sources mDNSlocal mDNSs32 DNSDigest_Base64ToBin(const char *src, mDNSu8 *target, mDNSu32 targsize) { int tarindex, state, ch; const char *pos; state = 0; tarindex = 0; while ((ch = *src++) != '\0') { if (mDNSisspace(ch)) /* Skip whitespace anywhere. */ continue; if (ch == Pad64) break; pos = mDNSstrchr(Base64, ch); if (pos == 0) /* A non-base64 character. */ return (-1); switch (state) { case 0: if (target) { if ((mDNSu32)tarindex >= targsize) return (-1); target[tarindex] = (mDNSu8)((pos - Base64) << 2); } state = 1; break; case 1: if (target) { if ((mDNSu32)tarindex + 1 >= targsize) return (-1); target[tarindex] |= (pos - Base64) >> 4; target[tarindex+1] = (mDNSu8)(((pos - Base64) & 0x0f) << 4); } tarindex++; state = 2; break; case 2: if (target) { if ((mDNSu32)tarindex + 1 >= targsize) return (-1); target[tarindex] |= (pos - Base64) >> 2; target[tarindex+1] = (mDNSu8)(((pos - Base64) & 0x03) << 6); } tarindex++; state = 3; break; case 3: if (target) { if ((mDNSu32)tarindex >= targsize) return (-1); target[tarindex] |= (pos - Base64); } tarindex++; state = 0; break; default: return -1; } } /* * We are done decoding Base-64 chars. Let's see if we ended * on a byte boundary, and/or with erroneous trailing characters. */ if (ch == Pad64) { /* We got a pad char. */ ch = *src++; /* Skip it, get next. */ switch (state) { case 0: /* Invalid = in first position */ case 1: /* Invalid = in second position */ return (-1); case 2: /* Valid, means one byte of info */ /* Skip any number of spaces. */ for ((void)mDNSNULL; ch != '\0'; ch = *src++) if (!mDNSisspace(ch)) break; /* Make sure there is another trailing = sign. */ if (ch != Pad64) return (-1); ch = *src++; /* Skip the = */ /* Fall through to "single trailing =" case. */ /* FALLTHROUGH */ case 3: /* Valid, means two bytes of info */ /* * We know this char is an =. Is there anything but * whitespace after it? */ for ((void)mDNSNULL; ch != '\0'; ch = *src++) if (!mDNSisspace(ch)) return (-1); /* * Now make sure for cases 2 and 3 that the "extra" * bits that slopped past the last full byte were * zeros. If we don't check them, they become a * subliminal channel. */ if (target && target[tarindex] != 0) return (-1); } } else { /* * We ended by seeing the end of the string. Make sure we * have no partial bytes lying around. */ if (state != 0) return (-1); } return (tarindex); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - API exported to mDNS Core #endif // Constants #define HMAC_IPAD 0x36 #define HMAC_OPAD 0x5c #define MD5_LEN 16 #define HMAC_MD5_AlgName "\010" "hmac-md5" "\007" "sig-alg" "\003" "reg" "\003" "int" // Adapted from Appendix, RFC 2104 mDNSlocal void DNSDigest_ConstructHMACKey(DomainAuthInfo *info, const mDNSu8 *key, mDNSu32 len) { MD5_CTX k; mDNSu8 buf[MD5_LEN]; int i; // If key is longer than HMAC_LEN reset it to MD5(key) if (len > HMAC_LEN) { MD5_Init(&k); MD5_Update(&k, key, len); MD5_Final(buf, &k); key = buf; len = MD5_LEN; } // store key in pads mDNSPlatformMemZero(info->keydata_ipad, HMAC_LEN); mDNSPlatformMemZero(info->keydata_opad, HMAC_LEN); mDNSPlatformMemCopy(info->keydata_ipad, key, len); mDNSPlatformMemCopy(info->keydata_opad, key, len); // XOR key with ipad and opad values for (i = 0; i < HMAC_LEN; i++) { info->keydata_ipad[i] ^= HMAC_IPAD; info->keydata_opad[i] ^= HMAC_OPAD; } } mDNSexport mDNSs32 DNSDigest_ConstructHMACKeyfromBase64(DomainAuthInfo *info, const char *b64key) { mDNSu8 keybuf[1024]; mDNSs32 keylen = DNSDigest_Base64ToBin(b64key, keybuf, sizeof(keybuf)); if (keylen < 0) return(keylen); DNSDigest_ConstructHMACKey(info, keybuf, (mDNSu32)keylen); return(keylen); } mDNSexport void DNSDigest_SignMessage(DNSMessage *msg, mDNSu8 **end, DomainAuthInfo *info, mDNSu16 tcode) { AuthRecord tsig; mDNSu8 *rdata, *const countPtr = (mDNSu8 *)&msg->h.numAdditionals; // Get existing numAdditionals value mDNSu32 utc32; mDNSu8 utc48[6]; mDNSu8 digest[MD5_LEN]; mDNSu8 *ptr = *end; mDNSu32 len; mDNSOpaque16 buf; MD5_CTX c; mDNSu16 numAdditionals = (mDNSu16)((mDNSu16)countPtr[0] << 8 | countPtr[1]); // Init MD5 context, digest inner key pad and message MD5_Init(&c); MD5_Update(&c, info->keydata_ipad, HMAC_LEN); MD5_Update(&c, (mDNSu8 *)msg, (unsigned long)(*end - (mDNSu8 *)msg)); // Construct TSIG RR, digesting variables as apporpriate mDNS_SetupResourceRecord(&tsig, mDNSNULL, 0, kDNSType_TSIG, 0, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); // key name AssignDomainName(&tsig.namestorage, &info->keyname); MD5_Update(&c, info->keyname.c, DomainNameLength(&info->keyname)); // class tsig.resrec.rrclass = kDNSQClass_ANY; buf = mDNSOpaque16fromIntVal(kDNSQClass_ANY); MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // ttl tsig.resrec.rroriginalttl = 0; MD5_Update(&c, (mDNSu8 *)&tsig.resrec.rroriginalttl, sizeof(tsig.resrec.rroriginalttl)); // alg name AssignConstStringDomainName(&tsig.resrec.rdata->u.name, HMAC_MD5_AlgName); len = DomainNameLengthLimit((domainname *)HMAC_MD5_AlgName, (mDNSu8 *)HMAC_MD5_AlgName + sizeof HMAC_MD5_AlgName); rdata = tsig.resrec.rdata->u.data + len; MD5_Update(&c, (mDNSu8 *)HMAC_MD5_AlgName, len); // time // get UTC (universal time), convert to 48-bit unsigned in network byte order utc32 = (mDNSu32)mDNSPlatformUTC(); if (utc32 == (unsigned)-1) { LogMsg("ERROR: DNSDigest_SignMessage - mDNSPlatformUTC returned bad time -1"); *end = mDNSNULL; } utc48[0] = 0; utc48[1] = 0; utc48[2] = (mDNSu8)((utc32 >> 24) & 0xff); utc48[3] = (mDNSu8)((utc32 >> 16) & 0xff); utc48[4] = (mDNSu8)((utc32 >> 8) & 0xff); utc48[5] = (mDNSu8)( utc32 & 0xff); mDNSPlatformMemCopy(rdata, utc48, 6); rdata += 6; MD5_Update(&c, utc48, 6); // 300 sec is fudge recommended in RFC 2485 rdata[0] = (mDNSu8)((300 >> 8) & 0xff); rdata[1] = (mDNSu8)( 300 & 0xff); MD5_Update(&c, rdata, sizeof(mDNSOpaque16)); rdata += sizeof(mDNSOpaque16); // digest error (tcode) and other data len (zero) - we'll add them to the rdata later buf.b[0] = (mDNSu8)((tcode >> 8) & 0xff); buf.b[1] = (mDNSu8)( tcode & 0xff); MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // error buf.NotAnInteger = 0; MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // other data len // finish the message & tsig var hash MD5_Final(digest, &c); // perform outer MD5 (outer key pad, inner digest) MD5_Init(&c); MD5_Update(&c, info->keydata_opad, HMAC_LEN); MD5_Update(&c, digest, MD5_LEN); MD5_Final(digest, &c); // set remaining rdata fields rdata[0] = (mDNSu8)((MD5_LEN >> 8) & 0xff); rdata[1] = (mDNSu8)( MD5_LEN & 0xff); rdata += sizeof(mDNSOpaque16); mDNSPlatformMemCopy(rdata, digest, MD5_LEN); // MAC rdata += MD5_LEN; rdata[0] = msg->h.id.b[0]; // original ID rdata[1] = msg->h.id.b[1]; rdata[2] = (mDNSu8)((tcode >> 8) & 0xff); rdata[3] = (mDNSu8)( tcode & 0xff); rdata[4] = 0; // other data len rdata[5] = 0; rdata += 6; tsig.resrec.rdlength = (mDNSu16)(rdata - tsig.resrec.rdata->u.data); *end = PutResourceRecordTTLJumbo(msg, ptr, &numAdditionals, &tsig.resrec, 0); if (!*end) { LogMsg("ERROR: DNSDigest_SignMessage - could not put TSIG"); *end = mDNSNULL; return; } // Write back updated numAdditionals value countPtr[0] = (mDNSu8)(numAdditionals >> 8); countPtr[1] = (mDNSu8)(numAdditionals & 0xFF); } mDNSexport mDNSBool DNSDigest_VerifyMessage(DNSMessage *msg, mDNSu8 *end, LargeCacheRecord * lcr, DomainAuthInfo *info, mDNSu16 * rcode, mDNSu16 * tcode) { mDNSu8 * ptr = (mDNSu8*) &lcr->r.resrec.rdata->u.data; mDNSs32 now; mDNSs32 then; mDNSu8 thisDigest[MD5_LEN]; mDNSu8 thatDigest[MD5_LEN]; mDNSOpaque16 buf; mDNSu8 utc48[6]; mDNSs32 delta; mDNSu16 fudge; domainname * algo; MD5_CTX c; mDNSBool ok = mDNSfalse; // We only support HMAC-MD5 for now algo = (domainname*) ptr; if (!SameDomainName(algo, (domainname *)HMAC_MD5_AlgName)) { LogMsg("ERROR: DNSDigest_VerifyMessage - TSIG algorithm not supported: %##s", algo->c); *rcode = kDNSFlag1_RC_NotAuth; *tcode = TSIG_ErrBadKey; ok = mDNSfalse; goto exit; } ptr += DomainNameLength(algo); // Check the times now = mDNSPlatformUTC(); if (now == -1) { LogMsg("ERROR: DNSDigest_VerifyMessage - mDNSPlatformUTC returned bad time -1"); *rcode = kDNSFlag1_RC_NotAuth; *tcode = TSIG_ErrBadTime; ok = mDNSfalse; goto exit; } // Get the 48 bit time field, skipping over the first word utc48[0] = *ptr++; utc48[1] = *ptr++; utc48[2] = *ptr++; utc48[3] = *ptr++; utc48[4] = *ptr++; utc48[5] = *ptr++; then = (mDNSs32)NToH32(utc48 + sizeof(mDNSu16)); fudge = NToH16(ptr); ptr += sizeof(mDNSu16); delta = (now > then) ? now - then : then - now; if (delta > fudge) { LogMsg("ERROR: DNSDigest_VerifyMessage - time skew > %d", fudge); *rcode = kDNSFlag1_RC_NotAuth; *tcode = TSIG_ErrBadTime; ok = mDNSfalse; goto exit; } // MAC size ptr += sizeof(mDNSu16); // MAC mDNSPlatformMemCopy(thatDigest, ptr, MD5_LEN); // Init MD5 context, digest inner key pad and message MD5_Init(&c); MD5_Update(&c, info->keydata_ipad, HMAC_LEN); MD5_Update(&c, (mDNSu8*) msg, (unsigned long)(end - (mDNSu8*) msg)); // Key name MD5_Update(&c, lcr->r.resrec.name->c, DomainNameLength(lcr->r.resrec.name)); // Class name buf = mDNSOpaque16fromIntVal(lcr->r.resrec.rrclass); MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // TTL MD5_Update(&c, (mDNSu8*) &lcr->r.resrec.rroriginalttl, sizeof(lcr->r.resrec.rroriginalttl)); // Algorithm MD5_Update(&c, algo->c, DomainNameLength(algo)); // Time MD5_Update(&c, utc48, 6); // Fudge buf = mDNSOpaque16fromIntVal(fudge); MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // Digest error and other data len (both zero) - we'll add them to the rdata later buf.NotAnInteger = 0; MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // error MD5_Update(&c, buf.b, sizeof(mDNSOpaque16)); // other data len // Finish the message & tsig var hash MD5_Final(thisDigest, &c); // perform outer MD5 (outer key pad, inner digest) MD5_Init(&c); MD5_Update(&c, info->keydata_opad, HMAC_LEN); MD5_Update(&c, thisDigest, MD5_LEN); MD5_Final(thisDigest, &c); if (!mDNSPlatformMemSame(thisDigest, thatDigest, MD5_LEN)) { LogMsg("ERROR: DNSDigest_VerifyMessage - bad signature"); *rcode = kDNSFlag1_RC_NotAuth; *tcode = TSIG_ErrBadSig; ok = mDNSfalse; goto exit; } // set remaining rdata fields ok = mDNStrue; exit: return ok; } #ifdef __cplusplus } #endif /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2011-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __DNS_PROXY_H #define __DNS_PROXY_H #include "mDNSEmbeddedAPI.h" #include "DNSCommon.h" extern void ProxyUDPCallback(void *socket, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID, void *context); extern void ProxyTCPCallback(void *socket, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID, void *context); #if MDNSRESPONDER_SUPPORTS(APPLE, DNS_PROXY_DNS64) extern void DNSProxyInit(mDNSu32 IpIfArr[MaxIp], mDNSu32 OpIf, const mDNSu8 IPv6Prefix[16], int IPv6PrefixLen, mDNSBool alwaysSynthesize); #else extern void DNSProxyInit(mDNSu32 IpIfArr[MaxIp], mDNSu32 OpIf); #endif extern void DNSProxyTerminate(void); #endif // __DNS_PROXY_H /* -*- Mode: C; tab-width: 4; c-file-style: "bsd"; c-basic-offset: 4; fill-column: 108; indent-tabs-mode: nil; -*- * * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * This code is completely 100% portable C. It does not depend on any external header files * from outside the mDNS project -- all the types it expects to find are defined right here. * * The previous point is very important: This file does not depend on any external * header files. It should compile on *any* platform that has a C compiler, without * making *any* assumptions about availability of so-called "standard" C functions, * routines, or types (which may or may not be present on any given platform). */ #include "DNSCommon.h" // Defines general DNS utility routines #include "uDNS.h" // Defines entry points into unicast-specific routines #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) #include "D2D.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) #include #endif #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) #include "dnssd_analytics.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) #include "QuerierSupport.h" #endif // Disable certain benign warnings with Microsoft compilers #if (defined(_MSC_VER)) // Disable "conditional expression is constant" warning for debug macros. // Otherwise, this generates warnings for the perfectly natural construct "while(1)" // If someone knows a variant way of writing "while(1)" that doesn't generate warning messages, please let us know #pragma warning(disable:4127) // Disable "assignment within conditional expression". // Other compilers understand the convention that if you place the assignment expression within an extra pair // of parentheses, this signals to the compiler that you really intended an assignment and no warning is necessary. // The Microsoft compiler doesn't understand this convention, so in the absense of any other way to signal // to the compiler that the assignment is intentional, we have to just turn this warning off completely. #pragma warning(disable:4706) #endif #include "dns_sd.h" // for kDNSServiceFlags* definitions #include "dns_sd_internal.h" #if APPLE_OSX_mDNSResponder // Delay in seconds before disabling multicast after there are no active queries or registrations. #define BONJOUR_DISABLE_DELAY 60 #endif #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) #include WCFConnection *WCFConnectionNew(void) __attribute__((weak_import)); void WCFConnectionDealloc(WCFConnection* c) __attribute__((weak_import)); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) #include "Metrics.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) #include "DNS64.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #include "dnssec_v2.h" #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // Forward declarations mDNSlocal void BeginSleepProcessing(mDNS *const m); mDNSlocal void RetrySPSRegistrations(mDNS *const m); mDNSlocal void SendWakeup(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSEthAddr *EthAddr, mDNSOpaque48 *password, mDNSBool unicastOnly); #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSlocal mDNSBool LocalRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q); #endif mDNSlocal void mDNS_PurgeBeforeResolve(mDNS *const m, DNSQuestion *q); mDNSlocal void mDNS_SendKeepalives(mDNS *const m); mDNSlocal void mDNS_ExtractKeepaliveInfo(AuthRecord *ar, mDNSu32 *timeout, mDNSAddr *laddr, mDNSAddr *raddr, mDNSEthAddr *eth, mDNSu32 *seq, mDNSu32 *ack, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu16 *win); typedef mDNSu32 DeadvertiseFlags; #define kDeadvertiseFlag_NormalHostname (1U << 0) #define kDeadvertiseFlag_RandHostname (1U << 1) #define kDeadvertiseFlag_All (kDeadvertiseFlag_NormalHostname | kDeadvertiseFlag_RandHostname) mDNSlocal void DeadvertiseInterface(mDNS *const m, NetworkInterfaceInfo *set, DeadvertiseFlags flags); mDNSlocal void AdvertiseInterfaceIfNeeded(mDNS *const m, NetworkInterfaceInfo *set); mDNSlocal mDNSu8 *GetValueForMACAddr(mDNSu8 *ptr, mDNSu8 *limit, mDNSEthAddr *eth); // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Program Constants #endif // To Turn OFF mDNS_Tracer set MDNS_TRACER to 0 or undef it #define MDNS_TRACER 1 // Any records bigger than this are considered 'large' records #define SmallRecordLimit 1024 #define kMaxUpdateCredits 10 #define kUpdateCreditRefreshInterval (mDNSPlatformOneSecond * 6) // define special NR_AnswerTo values #define NR_AnswerMulticast (mDNSu8*)~0 #define NR_AnswerUnicast (mDNSu8*)~1 // Question default timeout values #define DEFAULT_MCAST_TIMEOUT 5 #define DEFAULT_LO_OR_P2P_TIMEOUT 5 // The code (see SendQueries() and BuildQuestion()) needs to have the // RequestUnicast value set to a value one greater than the number of times you want the query // sent with the "request unicast response" (QU) bit set. #define SET_QU_IN_FIRST_QUERY 2 #define kDefaultRequestUnicastCount SET_QU_IN_FIRST_QUERY // The time needed to offload records to a sleep proxy after powerd sends the kIOMessageSystemWillSleep notification #define DARK_WAKE_DELAY_SLEEP 5 #define kDarkWakeDelaySleep (mDNSPlatformOneSecond * DARK_WAKE_DELAY_SLEEP) // The maximum number of times we delay probing to prevent spurious conflicts due to stale packets #define MAX_CONFLICT_PROCESSING_DELAYS 3 // RFC 6762 defines Passive Observation Of Failures (POOF) // // A host observes the multicast queries issued by the other hosts on // the network. One of the major benefits of also sending responses // using multicast is that it allows all hosts to see the responses // (or lack thereof) to those queries. // // If a host sees queries, for which a record in its cache would be // expected to be given as an answer in a multicast response, but no // such answer is seen, then the host may take this as an indication // that the record may no longer be valid. // // After seeing two or more of these queries, and seeing no multicast // response containing the expected answer within ten seconds, then even // though its TTL may indicate that it is not yet due to expire, that // record SHOULD be flushed from the cache. // // #define POOF_ENABLED 1 mDNSexport const char *const mDNS_DomainTypeNames[] = { "b._dns-sd._udp.", // Browse "db._dns-sd._udp.", // Default Browse "lb._dns-sd._udp.", // Automatic Browse "r._dns-sd._udp.", // Registration "dr._dns-sd._udp." // Default Registration }; #ifdef UNICAST_DISABLED #define uDNS_IsActiveQuery(q, u) mDNSfalse #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - General Utility Functions #endif #if MDNS_MALLOC_DEBUGGING // When doing memory allocation debugging, this function traverses all lists in the mDNS query // structures and caches and checks each entry in the list to make sure it's still good. mDNSlocal void mDNS_ValidateLists(void *context) { mDNS *m = context; #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) mDNSu32 NumAllInterfaceRecords = 0; mDNSu32 NumAllInterfaceQuestions = 0; #endif // Check core mDNS lists AuthRecord *rr; for (rr = m->ResourceRecords; rr; rr=rr->next) { if (rr->next == (AuthRecord *)~0 || rr->resrec.RecordType == 0 || rr->resrec.RecordType == 0xFF) LogMemCorruption("ResourceRecords list: %p is garbage (%X)", rr, rr->resrec.RecordType); if (rr->resrec.name != &rr->namestorage) LogMemCorruption("ResourceRecords list: %p name %p does not point to namestorage %p %##s", rr, rr->resrec.name->c, rr->namestorage.c, rr->namestorage.c); #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (!AuthRecord_uDNS(rr) && !RRLocalOnly(rr)) NumAllInterfaceRecords++; #endif } for (rr = m->DuplicateRecords; rr; rr=rr->next) { if (rr->next == (AuthRecord *)~0 || rr->resrec.RecordType == 0 || rr->resrec.RecordType == 0xFF) LogMemCorruption("DuplicateRecords list: %p is garbage (%X)", rr, rr->resrec.RecordType); #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (!AuthRecord_uDNS(rr) && !RRLocalOnly(rr)) NumAllInterfaceRecords++; #endif } rr = m->NewLocalRecords; if (rr) if (rr->next == (AuthRecord *)~0 || rr->resrec.RecordType == 0 || rr->resrec.RecordType == 0xFF) LogMemCorruption("NewLocalRecords: %p is garbage (%X)", rr, rr->resrec.RecordType); rr = m->CurrentRecord; if (rr) if (rr->next == (AuthRecord *)~0 || rr->resrec.RecordType == 0 || rr->resrec.RecordType == 0xFF) LogMemCorruption("CurrentRecord: %p is garbage (%X)", rr, rr->resrec.RecordType); DNSQuestion *q; for (q = m->Questions; q; q=q->next) { if (q->next == (DNSQuestion*)~0 || q->ThisQInterval == (mDNSs32) ~0) LogMemCorruption("Questions list: %p is garbage (%lX %p)", q, q->ThisQInterval, q->next); if (q->DuplicateOf && q->LocalSocket) LogMemCorruption("Questions list: Duplicate Question %p should not have LocalSocket set %##s (%s)", q, q->qname.c, DNSTypeName(q->qtype)); #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (!LocalOnlyOrP2PInterface(q->InterfaceID) && mDNSOpaque16IsZero(q->TargetQID)) NumAllInterfaceQuestions++; #endif } CacheGroup *cg; CacheRecord *cr; mDNSu32 slot; FORALL_CACHERECORDS(slot, cg, cr) { if (cr->resrec.RecordType == 0 || cr->resrec.RecordType == 0xFF) LogMemCorruption("Cache slot %lu: %p is garbage (%X)", slot, cr, cr->resrec.RecordType); if (cr->CRActiveQuestion) { for (q = m->Questions; q; q=q->next) if (q == cr->CRActiveQuestion) break; if (!q) LogMemCorruption("Cache slot %lu: CRActiveQuestion %p not in m->Questions list %s", slot, cr->CRActiveQuestion, CRDisplayString(m, cr)); } } #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (m->NumAllInterfaceRecords != NumAllInterfaceRecords) LogMemCorruption("NumAllInterfaceRecords is %d should be %d", m->NumAllInterfaceRecords, NumAllInterfaceRecords); if (m->NumAllInterfaceQuestions != NumAllInterfaceQuestions) LogMemCorruption("NumAllInterfaceQuestions is %d should be %d", m->NumAllInterfaceQuestions, NumAllInterfaceQuestions); #endif // MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) } #endif // MDNS_MALLOC_DEBUGGING // Returns true if this is a unique, authoritative LocalOnly record that answers questions of type // A, AAAA , CNAME, or PTR. The caller should answer the question with this record and not send out // the question on the wire if LocalOnlyRecordAnswersQuestion() also returns true. // Main use is to handle /etc/hosts records and the LocalOnly PTR records created for localhost. #define UniqueLocalOnlyRecord(rr) ((rr)->ARType == AuthRecordLocalOnly && \ (rr)->resrec.RecordType & kDNSRecordTypeUniqueMask && \ ((rr)->resrec.rrtype == kDNSType_A || (rr)->resrec.rrtype == kDNSType_AAAA || \ (rr)->resrec.rrtype == kDNSType_CNAME || \ (rr)->resrec.rrtype == kDNSType_PTR)) mDNSlocal void SetNextQueryStopTime(mDNS *const m, const DNSQuestion *const q) { mDNS_CheckLock(m); if (m->NextScheduledStopTime - q->StopTime > 0) m->NextScheduledStopTime = q->StopTime; } mDNSexport void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q) { mDNS_CheckLock(m); if (ActiveQuestion(q)) { // Depending on whether this is a multicast or unicast question we want to set either: // m->NextScheduledQuery = NextQSendTime(q) or // m->NextuDNSEvent = NextQSendTime(q) mDNSs32 *const timer = mDNSOpaque16IsZero(q->TargetQID) ? &m->NextScheduledQuery : &m->NextuDNSEvent; if (*timer - NextQSendTime(q) > 0) *timer = NextQSendTime(q); } } mDNSlocal void ReleaseAuthEntity(AuthHash *r, AuthEntity *e) { #if MDNS_MALLOC_DEBUGGING >= 1 unsigned int i; for (i=0; inext = r->rrauth_free; r->rrauth_free = e; r->rrauth_totalused--; } mDNSlocal void ReleaseAuthGroup(AuthHash *r, AuthGroup **cp) { AuthEntity *e = (AuthEntity *)(*cp); LogMsg("ReleaseAuthGroup: Releasing AuthGroup %##s", (*cp)->name->c); if ((*cp)->rrauth_tail != &(*cp)->members) LogMsg("ERROR: (*cp)->members == mDNSNULL but (*cp)->rrauth_tail != &(*cp)->members)"); if ((*cp)->name != (domainname*)((*cp)->namestorage)) mDNSPlatformMemFree((*cp)->name); (*cp)->name = mDNSNULL; *cp = (*cp)->next; // Cut record from list ReleaseAuthEntity(r, e); } mDNSlocal AuthEntity *GetAuthEntity(AuthHash *r, const AuthGroup *const PreserveAG) { AuthEntity *e = mDNSNULL; if (r->rrauth_lock) { LogMsg("GetFreeCacheRR ERROR! Cache already locked!"); return(mDNSNULL); } r->rrauth_lock = 1; if (!r->rrauth_free) { // We allocate just one AuthEntity at a time because we need to be able // free them all individually which normally happens when we parse /etc/hosts into // AuthHash where we add the "new" entries and discard (free) the already added // entries. If we allocate as chunks, we can't free them individually. AuthEntity *storage = (AuthEntity *) mDNSPlatformMemAllocateClear(sizeof(*storage)); storage->next = mDNSNULL; r->rrauth_free = storage; } // If we still have no free records, recycle all the records we can. // Enumerating the entire auth is moderately expensive, so when we do it, we reclaim all the records we can in one pass. if (!r->rrauth_free) { mDNSu32 oldtotalused = r->rrauth_totalused; mDNSu32 slot; for (slot = 0; slot < AUTH_HASH_SLOTS; slot++) { AuthGroup **cp = &r->rrauth_hash[slot]; while (*cp) { if ((*cp)->members || (*cp)==PreserveAG) cp=&(*cp)->next; else ReleaseAuthGroup(r, cp); } } LogInfo("GetAuthEntity: Recycled %d records to reduce auth cache from %d to %d", oldtotalused - r->rrauth_totalused, oldtotalused, r->rrauth_totalused); } if (r->rrauth_free) // If there are records in the free list, take one { e = r->rrauth_free; r->rrauth_free = e->next; if (++r->rrauth_totalused >= r->rrauth_report) { LogInfo("RR Auth now using %ld objects", r->rrauth_totalused); if (r->rrauth_report < 100) r->rrauth_report += 10; else if (r->rrauth_report < 1000) r->rrauth_report += 100; else r->rrauth_report += 1000; } mDNSPlatformMemZero(e, sizeof(*e)); } r->rrauth_lock = 0; return(e); } mDNSexport AuthGroup *AuthGroupForName(AuthHash *r, const mDNSu32 namehash, const domainname *const name) { AuthGroup *ag; const mDNSu32 slot = namehash % AUTH_HASH_SLOTS; for (ag = r->rrauth_hash[slot]; ag; ag=ag->next) if (ag->namehash == namehash && SameDomainName(ag->name, name)) break; return(ag); } mDNSexport AuthGroup *AuthGroupForRecord(AuthHash *r, const ResourceRecord *const rr) { return(AuthGroupForName(r, rr->namehash, rr->name)); } mDNSlocal AuthGroup *GetAuthGroup(AuthHash *r, const ResourceRecord *const rr) { mDNSu16 namelen = DomainNameLength(rr->name); AuthGroup *ag = (AuthGroup*)GetAuthEntity(r, mDNSNULL); const mDNSu32 slot = rr->namehash % AUTH_HASH_SLOTS; if (!ag) { LogMsg("GetAuthGroup: Failed to allocate memory for %##s", rr->name->c); return(mDNSNULL); } ag->next = r->rrauth_hash[slot]; ag->namehash = rr->namehash; ag->members = mDNSNULL; ag->rrauth_tail = &ag->members; ag->NewLocalOnlyRecords = mDNSNULL; if (namelen > sizeof(ag->namestorage)) ag->name = (domainname *) mDNSPlatformMemAllocate(namelen); else ag->name = (domainname*)ag->namestorage; if (!ag->name) { LogMsg("GetAuthGroup: Failed to allocate name storage for %##s", rr->name->c); ReleaseAuthEntity(r, (AuthEntity*)ag); return(mDNSNULL); } AssignDomainName(ag->name, rr->name); if (AuthGroupForRecord(r, rr)) LogMsg("GetAuthGroup: Already have AuthGroup for %##s", rr->name->c); r->rrauth_hash[slot] = ag; if (AuthGroupForRecord(r, rr) != ag) LogMsg("GetAuthGroup: Not finding AuthGroup for %##s", rr->name->c); return(ag); } // Returns the AuthGroup in which the AuthRecord was inserted mDNSexport AuthGroup *InsertAuthRecord(mDNS *const m, AuthHash *r, AuthRecord *rr) { AuthGroup *ag; (void)m; ag = AuthGroupForRecord(r, &rr->resrec); if (!ag) ag = GetAuthGroup(r, &rr->resrec); // If we don't have a AuthGroup for this name, make one now if (ag) { *(ag->rrauth_tail) = rr; // Append this record to tail of cache slot list ag->rrauth_tail = &(rr->next); // Advance tail pointer } return ag; } mDNSexport AuthGroup *RemoveAuthRecord(mDNS *const m, AuthHash *r, AuthRecord *rr) { AuthGroup *a; AuthRecord **rp; a = AuthGroupForRecord(r, &rr->resrec); if (!a) { LogMsg("RemoveAuthRecord: ERROR!! AuthGroup not found for %s", ARDisplayString(m, rr)); return mDNSNULL; } rp = &a->members; while (*rp) { if (*rp != rr) rp=&(*rp)->next; else { // We don't break here, so that we can set the tail below without tracking "prev" pointers LogInfo("RemoveAuthRecord: removing auth record %s from table", ARDisplayString(m, rr)); *rp = (*rp)->next; // Cut record from list } } // TBD: If there are no more members, release authgroup ? a->rrauth_tail = rp; return a; } mDNSexport CacheGroup *CacheGroupForName(const mDNS *const m, const mDNSu32 namehash, const domainname *const name) { CacheGroup *cg; mDNSu32 slot = HashSlotFromNameHash(namehash); for (cg = m->rrcache_hash[slot]; cg; cg=cg->next) if (cg->namehash == namehash && SameDomainName(cg->name, name)) break; return(cg); } mDNSlocal CacheGroup *CacheGroupForRecord(const mDNS *const m, const ResourceRecord *const rr) { return(CacheGroupForName(m, rr->namehash, rr->name)); } mDNSexport mDNSBool mDNS_AddressIsLocalSubnet(mDNS *const m, const mDNSInterfaceID InterfaceID, const mDNSAddr *addr) { NetworkInterfaceInfo *intf; if (addr->type == mDNSAddrType_IPv4) { // Normally we resist touching the NotAnInteger fields, but here we're doing tricky bitwise masking so we make an exception if (mDNSv4AddressIsLinkLocal(&addr->ip.v4)) return(mDNStrue); for (intf = m->HostInterfaces; intf; intf = intf->next) if (intf->ip.type == addr->type && intf->InterfaceID == InterfaceID && intf->McastTxRx) if (((intf->ip.ip.v4.NotAnInteger ^ addr->ip.v4.NotAnInteger) & intf->mask.ip.v4.NotAnInteger) == 0) return(mDNStrue); } if (addr->type == mDNSAddrType_IPv6) { if (mDNSv6AddressIsLinkLocal(&addr->ip.v6)) return(mDNStrue); for (intf = m->HostInterfaces; intf; intf = intf->next) if (intf->ip.type == addr->type && intf->InterfaceID == InterfaceID && intf->McastTxRx) if ((((intf->ip.ip.v6.l[0] ^ addr->ip.v6.l[0]) & intf->mask.ip.v6.l[0]) == 0) && (((intf->ip.ip.v6.l[1] ^ addr->ip.v6.l[1]) & intf->mask.ip.v6.l[1]) == 0) && (((intf->ip.ip.v6.l[2] ^ addr->ip.v6.l[2]) & intf->mask.ip.v6.l[2]) == 0) && (((intf->ip.ip.v6.l[3] ^ addr->ip.v6.l[3]) & intf->mask.ip.v6.l[3]) == 0)) return(mDNStrue); } return(mDNSfalse); } mDNSlocal NetworkInterfaceInfo *FirstInterfaceForID(mDNS *const m, const mDNSInterfaceID InterfaceID) { NetworkInterfaceInfo *intf = m->HostInterfaces; while (intf && intf->InterfaceID != InterfaceID) intf = intf->next; return(intf); } mDNSlocal NetworkInterfaceInfo *FirstIPv4LLInterfaceForID(mDNS *const m, const mDNSInterfaceID InterfaceID) { NetworkInterfaceInfo *intf; if (!InterfaceID) return mDNSNULL; // Note: We don't check for InterfaceActive, as the active interface could be IPv6 and // we still want to find the first IPv4 Link-Local interface for (intf = m->HostInterfaces; intf; intf = intf->next) { if (intf->InterfaceID == InterfaceID && intf->ip.type == mDNSAddrType_IPv4 && mDNSv4AddressIsLinkLocal(&intf->ip.ip.v4)) { debugf("FirstIPv4LLInterfaceForID: found LL interface with address %.4a", &intf->ip.ip.v4); return intf; } } return (mDNSNULL); } mDNSexport char *InterfaceNameForID(mDNS *const m, const mDNSInterfaceID InterfaceID) { NetworkInterfaceInfo *intf = FirstInterfaceForID(m, InterfaceID); return(intf ? intf->ifname : mDNSNULL); } // Caller should hold the lock mDNSlocal void GenerateNegativeResponseEx(mDNS *const m, mDNSInterfaceID InterfaceID, QC_result qc, mDNSBool noData) { DNSQuestion *q; if (!m->CurrentQuestion) { LogMsg("GenerateNegativeResponse: ERROR!! CurrentQuestion not set"); return; } q = m->CurrentQuestion; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] GenerateNegativeResponse: Generating negative response for question " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); MakeNegativeCacheRecord(m, &m->rec.r, &q->qname, q->qnamehash, q->qtype, q->qclass, 60, InterfaceID, mDNSNULL); m->rec.r.resrec.negativeRecordType = noData ? kNegativeRecordType_NoData : kNegativeRecordType_Unspecified; // We need to force the response through in the following cases // // a) SuppressUnusable questions that are suppressed // b) Append search domains and retry the question // // The question may not have set Intermediates in which case we don't deliver negative responses. So, to force // through we use "QC_forceresponse". AnswerCurrentQuestionWithResourceRecord(m, &m->rec.r, qc); if (m->CurrentQuestion == q) { q->ThisQInterval = 0; } // Deactivate this question // Don't touch the question after this m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } #define GenerateNegativeResponse(M, INTERFACE_ID, QC) GenerateNegativeResponseEx(M, INTERFACE_ID, QC, mDNSfalse) mDNSexport void AnswerQuestionByFollowingCNAME(mDNS *const m, DNSQuestion *q, ResourceRecord *rr) { const mDNSBool selfref = SameDomainName(&q->qname, &rr->rdata->u.name); if (q->CNAMEReferrals >= 10 || selfref) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] AnswerQuestionByFollowingCNAME: %p " PRI_DM_NAME " (" PUB_S ") NOT following CNAME referral %d" PUB_S " for " PRI_S, q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), q->CNAMEReferrals, selfref ? " (Self-Referential)" : "", RRDisplayString(m, rr)); } else { UDPSocket *sock = q->LocalSocket; mDNSOpaque16 id = q->TargetQID; #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) uDNSMetrics metrics; #endif q->LocalSocket = mDNSNULL; // The SameDomainName check above is to ignore bogus CNAME records that point right back at // themselves. Without that check we can get into a case where we have two duplicate questions, // A and B, and when we stop question A, UpdateQuestionDuplicates copies the value of CNAMEReferrals // from A to B, and then A is re-appended to the end of the list as a duplicate of B (because // the target name is still the same), and then when we stop question B, UpdateQuestionDuplicates // copies the B's value of CNAMEReferrals back to A, and we end up not incrementing CNAMEReferrals // for either of them. This is not a problem for CNAME loops of two or more records because in // those cases the newly re-appended question A has a different target name and therefore cannot be // a duplicate of any other question ('B') which was itself a duplicate of the previous question A. // Right now we just stop and re-use the existing query. If we really wanted to be 100% perfect, // and track CNAMEs coming and going, we should really create a subordinate query here, // which we would subsequently cancel and retract if the CNAME referral record were removed. // In reality this is such a corner case we'll ignore it until someone actually needs it. LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] AnswerQuestionByFollowingCNAME: %p " PRI_DM_NAME " (" PUB_S ") following CNAME referral %d for " PRI_S, q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), q->CNAMEReferrals, RRDisplayString(m, rr)); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!mDNSOpaque16IsZero(q->TargetQID)) { // Must be called before zeroing out q->metrics below. Querier_PrepareQuestionForCNAMERestart(q); } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if ((q->CNAMEReferrals == 0) && !q->metrics.originalQName) { domainname * qName; mDNSu16 qNameLen; qNameLen = DomainNameLength(&q->qname); if ((qNameLen > 0) && (qNameLen <= MAX_DOMAIN_NAME)) { qName = (domainname *) mDNSPlatformMemAllocate(qNameLen); if (qName) { mDNSPlatformMemCopy(qName->c, q->qname.c, qNameLen); q->metrics.originalQName = qName; } } } metrics = q->metrics; // The metrics will be transplanted to the restarted question, so zero out the old copy instead of using // uDNSMetricsClear(), which will free any pointers to allocated memory. mDNSPlatformMemZero(&q->metrics, sizeof(q->metrics)); #endif mDNS_StopQuery_internal(m, q); // Stop old query AssignDomainName(&q->qname, &rr->rdata->u.name); // Update qname q->qnamehash = DomainNameHashValue(&q->qname); // and namehash // If a unicast query results in a CNAME that points to a .local, we need to re-try // this as unicast. Setting the mDNSInterface_Unicast tells mDNS_StartQuery_internal // to try this as unicast query even though it is a .local name if (!mDNSOpaque16IsZero(q->TargetQID) && IsLocalDomain(&q->qname)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] AnswerQuestionByFollowingCNAME: Resolving a .local CNAME %p " PRI_DM_NAME " (" PUB_S ") Record " PRI_S, q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), RRDisplayString(m, rr)); q->IsUnicastDotLocal = mDNStrue; } q->CNAMEReferrals += 1; // Increment value before calling mDNS_StartQuery_internal const mDNSu32 c = q->CNAMEReferrals; // Stash a copy of the new q->CNAMEReferrals value mDNS_StartQuery_internal(m, q); // start new query // Record how many times we've done this. We need to do this *after* mDNS_StartQuery_internal, // because mDNS_StartQuery_internal re-initializes CNAMEReferrals to zero q->CNAMEReferrals = c; #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) metrics.expiredAnswerState = q->metrics.expiredAnswerState; // We want the newly initialized state for this value metrics.dnsOverTCPState = q->metrics.dnsOverTCPState; // We want the newly initialized state for this value q->metrics = metrics; #endif if (sock) { // If our new query is a duplicate, then it can't have a socket of its own, so we have to close the one we saved. if (q->DuplicateOf) mDNSPlatformUDPClose(sock); else { // Transplant the old socket into the new question, and copy the query ID across too. // No need to close the old q->LocalSocket value because it won't have been created yet (they're made lazily on-demand). q->LocalSocket = sock; q->TargetQID = id; } } } } #ifdef USE_LIBIDN #include // #define DEBUG_PUNYCODE 1 mDNSlocal mDNSu8 *PunycodeConvert(const mDNSu8 *const src, mDNSu8 *const dst, const mDNSu8 *const end) { UErrorCode errorCode = U_ZERO_ERROR; UIDNAInfo info = UIDNA_INFO_INITIALIZER; UIDNA *uts46 = uidna_openUTS46(UIDNA_USE_STD3_RULES|UIDNA_NONTRANSITIONAL_TO_UNICODE, &errorCode); int32_t len = uidna_nameToASCII_UTF8(uts46, (const char *)src+1, src[0], (char *)dst+1, (int32_t)(end-(dst+1)), &info, &errorCode); uidna_close(uts46); #if DEBUG_PUNYCODE if (errorCode) LogMsg("uidna_nameToASCII_UTF8(%##s) failed errorCode %d", src, errorCode); if (info.errors) LogMsg("uidna_nameToASCII_UTF8(%##s) failed info.errors 0x%08X", src, info.errors); if (len > MAX_DOMAIN_LABEL) LogMsg("uidna_nameToASCII_UTF8(%##s) result too long %d", src, len); #endif if (errorCode || info.errors || len > MAX_DOMAIN_LABEL) return mDNSNULL; *dst = len; return(dst + 1 + len); } mDNSlocal mDNSBool IsHighASCIILabel(const mDNSu8 *d) { int i; for (i=1; i<=d[0]; i++) if (d[i] & 0x80) return mDNStrue; return mDNSfalse; } mDNSlocal const mDNSu8 *FindLastHighASCIILabel(const domainname *const d) { const mDNSu8 *ptr = d->c; const mDNSu8 *ans = mDNSNULL; while (ptr[0]) { const mDNSu8 *const next = ptr + 1 + ptr[0]; if (ptr[0] > MAX_DOMAIN_LABEL || next >= d->c + MAX_DOMAIN_NAME) return mDNSNULL; if (IsHighASCIILabel(ptr)) ans = ptr; ptr = next; } return ans; } mDNSlocal mDNSBool PerformNextPunycodeConversion(const DNSQuestion *const q, domainname *const newname) { const mDNSu8 *h = FindLastHighASCIILabel(&q->qname); #if DEBUG_PUNYCODE LogMsg("PerformNextPunycodeConversion: %##s (%s) Last High-ASCII Label %##s", q->qname.c, DNSTypeName(q->qtype), h); #endif if (!h) return mDNSfalse; // There are no high-ascii labels to convert mDNSu8 *const dst = PunycodeConvert(h, newname->c + (h - q->qname.c), newname->c + MAX_DOMAIN_NAME); if (!dst) return mDNSfalse; // The label was not convertible to Punycode else { // If Punycode conversion of final eligible label was successful, copy the rest of the domainname const mDNSu8 *const src = h + 1 + h[0]; const mDNSu8 remainder = DomainNameLength((domainname*)src); if (dst + remainder > newname->c + MAX_DOMAIN_NAME) return mDNSfalse; // Name too long -- cannot be converted to Punycode mDNSPlatformMemCopy(newname->c, q->qname.c, (mDNSu32)(h - q->qname.c)); // Fill in the leading part mDNSPlatformMemCopy(dst, src, remainder); // Fill in the trailing part #if DEBUG_PUNYCODE LogMsg("PerformNextPunycodeConversion: %##s converted to %##s", q->qname.c, newname->c); #endif return mDNStrue; } } #endif // USE_LIBIDN // For a single given DNSQuestion pointed to by CurrentQuestion, deliver an add/remove result for the single given AuthRecord // Note: All the callers should use the m->CurrentQuestion to see if the question is still valid or not mDNSlocal void AnswerLocalQuestionWithLocalAuthRecord(mDNS *const m, AuthRecord *rr, QC_result AddRecord) { DNSQuestion *q = m->CurrentQuestion; mDNSBool followcname; if (!q) { LogMsg("AnswerLocalQuestionWithLocalAuthRecord: ERROR!! CurrentQuestion NULL while answering with %s", ARDisplayString(m, rr)); return; } followcname = FollowCNAME(q, &rr->resrec, AddRecord); // We should not be delivering results for record types Unregistered, Deregistering, and (unverified) Unique if (!(rr->resrec.RecordType & kDNSRecordTypeActiveMask)) { LogMsg("AnswerLocalQuestionWithLocalAuthRecord: *NOT* delivering %s event for local record type %X %s", AddRecord ? "Add" : "Rmv", rr->resrec.RecordType, ARDisplayString(m, rr)); return; } // Indicate that we've given at least one positive answer for this record, so we should be prepared to send a goodbye for it if (AddRecord) rr->AnsweredLocalQ = mDNStrue; mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback if (q->QuestionCallback && !q->NoAnswer) { q->CurrentAnswers += AddRecord ? 1 : -1; if (UniqueLocalOnlyRecord(rr)) { if (!followcname || q->ReturnIntermed) { // Don't send this packet on the wire as we answered from /etc/hosts q->ThisQInterval = 0; q->LOAddressAnswers += AddRecord ? 1 : -1; q->QuestionCallback(m, q, &rr->resrec, AddRecord); } mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again // The callback above could have caused the question to stop. Detect that // using m->CurrentQuestion if (followcname && m->CurrentQuestion == q) AnswerQuestionByFollowingCNAME(m, q, &rr->resrec); return; } else { q->QuestionCallback(m, q, &rr->resrec, AddRecord); } } mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again } mDNSlocal void AnswerInterfaceAnyQuestionsWithLocalAuthRecord(mDNS *const m, AuthRecord *ar, QC_result AddRecord) { if (m->CurrentQuestion) LogMsg("AnswerInterfaceAnyQuestionsWithLocalAuthRecord: ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) { mDNSBool answered; DNSQuestion *q = m->CurrentQuestion; if (RRAny(ar)) answered = AuthRecordAnswersQuestion(ar, q); else answered = LocalOnlyRecordAnswersQuestion(ar, q); if (answered) AnswerLocalQuestionWithLocalAuthRecord(m, ar, AddRecord); // MUST NOT dereference q again if (m->CurrentQuestion == q) // If m->CurrentQuestion was not auto-advanced, do it ourselves now m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } // When a new local AuthRecord is created or deleted, AnswerAllLocalQuestionsWithLocalAuthRecord() // delivers the appropriate add/remove events to listening questions: // 1. It runs though all our LocalOnlyQuestions delivering answers as appropriate, // stopping if it reaches a NewLocalOnlyQuestion -- brand-new questions are handled by AnswerNewLocalOnlyQuestion(). // 2. If the AuthRecord is marked mDNSInterface_LocalOnly or mDNSInterface_P2P, then it also runs though // our main question list, delivering answers to mDNSInterface_Any questions as appropriate, // stopping if it reaches a NewQuestion -- brand-new questions are handled by AnswerNewQuestion(). // // AnswerAllLocalQuestionsWithLocalAuthRecord is used by the m->NewLocalRecords loop in mDNS_Execute(), // and by mDNS_Deregister_internal() mDNSlocal void AnswerAllLocalQuestionsWithLocalAuthRecord(mDNS *const m, AuthRecord *ar, QC_result AddRecord) { if (m->CurrentQuestion) LogMsg("AnswerAllLocalQuestionsWithLocalAuthRecord ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->LocalOnlyQuestions; while (m->CurrentQuestion && m->CurrentQuestion != m->NewLocalOnlyQuestions) { mDNSBool answered; DNSQuestion *q = m->CurrentQuestion; // We are called with both LocalOnly/P2P record or a regular AuthRecord if (RRAny(ar)) answered = AuthRecordAnswersQuestion(ar, q); else answered = LocalOnlyRecordAnswersQuestion(ar, q); if (answered) AnswerLocalQuestionWithLocalAuthRecord(m, ar, AddRecord); // MUST NOT dereference q again if (m->CurrentQuestion == q) // If m->CurrentQuestion was not auto-advanced, do it ourselves now m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; // If this AuthRecord is marked LocalOnly or P2P, then we want to deliver it to all local 'mDNSInterface_Any' questions if (ar->ARType == AuthRecordLocalOnly || ar->ARType == AuthRecordP2P) AnswerInterfaceAnyQuestionsWithLocalAuthRecord(m, ar, AddRecord); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Resource Record Utility Functions #endif #define RRTypeIsAddressType(T) ((T) == kDNSType_A || (T) == kDNSType_AAAA) mDNSlocal mDNSBool ResourceRecordIsValidAnswer(const AuthRecord *const rr) { if ((rr->resrec.RecordType & kDNSRecordTypeActiveMask) && ((rr->Additional1 == mDNSNULL) || (rr->Additional1->resrec.RecordType & kDNSRecordTypeActiveMask)) && ((rr->Additional2 == mDNSNULL) || (rr->Additional2->resrec.RecordType & kDNSRecordTypeActiveMask)) && ((rr->DependentOn == mDNSNULL) || (rr->DependentOn->resrec.RecordType & kDNSRecordTypeActiveMask))) { return mDNStrue; } else { return mDNSfalse; } } mDNSlocal mDNSBool IsInterfaceValidForAuthRecord(const AuthRecord *const rr, const mDNSInterfaceID InterfaceID) { if (rr->resrec.InterfaceID == mDNSInterface_Any) { return mDNSPlatformValidRecordForInterface(rr, InterfaceID); } else { return ((rr->resrec.InterfaceID == InterfaceID) ? mDNStrue : mDNSfalse); } } mDNSlocal mDNSBool ResourceRecordIsValidInterfaceAnswer(const AuthRecord *const rr, const mDNSInterfaceID interfaceID) { return ((IsInterfaceValidForAuthRecord(rr, interfaceID) && ResourceRecordIsValidAnswer(rr)) ? mDNStrue : mDNSfalse); } #define DefaultProbeCountForTypeUnique ((mDNSu8)3) #define DefaultProbeCountForRecordType(X) ((X) == kDNSRecordTypeUnique ? DefaultProbeCountForTypeUnique : (mDNSu8)0) // Parameters for handling probing conflicts #define kMaxAllowedMCastProbingConflicts 1 // Maximum number of conflicts to allow from mcast messages. #define kProbingConflictPauseDuration mDNSPlatformOneSecond // Duration of probing pause after an allowed mcast conflict. // See RFC 6762: "8.3 Announcing" // "The Multicast DNS responder MUST send at least two unsolicited responses, one second apart." // Send 4, which is really 8 since we send on both IPv4 and IPv6. #define InitialAnnounceCount ((mDNSu8)4) // For goodbye packets we set the count to 3, and for wakeups we set it to 18 // (which will be up to 15 wakeup attempts over the course of 30 seconds, // and then if the machine fails to wake, 3 goodbye packets). #define GoodbyeCount ((mDNSu8)3) #define WakeupCount ((mDNSu8)18) #define MAX_PROBE_RESTARTS ((mDNSu8)20) #define MAX_GHOST_TIME ((mDNSs32)((60*60*24*7)*mDNSPlatformOneSecond)) // One week // Number of wakeups we send if WakeOnResolve is set in the question #define InitialWakeOnResolveCount ((mDNSu8)3) // Note that the announce intervals use exponential backoff, doubling each time. The probe intervals do not. // This means that because the announce interval is doubled after sending the first packet, the first // observed on-the-wire inter-packet interval between announcements is actually one second. // The half-second value here may be thought of as a conceptual (non-existent) half-second delay *before* the first packet is sent. #define DefaultProbeIntervalForTypeUnique (mDNSPlatformOneSecond/4) #define DefaultAnnounceIntervalForTypeShared (mDNSPlatformOneSecond/2) #define DefaultAnnounceIntervalForTypeUnique (mDNSPlatformOneSecond/2) #define DefaultAPIntervalForRecordType(X) ((X) &kDNSRecordTypeActiveSharedMask ? DefaultAnnounceIntervalForTypeShared : \ (X) &kDNSRecordTypeUnique ? DefaultProbeIntervalForTypeUnique : \ (X) &kDNSRecordTypeActiveUniqueMask ? DefaultAnnounceIntervalForTypeUnique : 0) #define TimeToAnnounceThisRecord(RR,time) ((RR)->AnnounceCount && (time) - ((RR)->LastAPTime + (RR)->ThisAPInterval) >= 0) #define TicksTTL(RR) ((mDNSs32)(RR)->resrec.rroriginalttl * mDNSPlatformOneSecond) #define RRExpireTime(RR) ((RR)->TimeRcvd + TicksTTL(RR)) // Adjustment factor to avoid race condition (used for unicast cache entries) : // Suppose real record has TTL of 3600, and our local caching server has held it for 3500 seconds, so it returns an aged TTL of 100. // If we do our normal refresh at 80% of the TTL, our local caching server will return 20 seconds, so we'll do another // 80% refresh after 16 seconds, and then the server will return 4 seconds, and so on, in the fashion of Zeno's paradox. // To avoid this, we extend the record's effective TTL to give it a little extra grace period. // We adjust the 100 second TTL to 127. This means that when we do our 80% query after 102 seconds, // the cached copy at our local caching server will already have expired, so the server will be forced // to fetch a fresh copy from the authoritative server, and then return a fresh record with the full TTL of 3600 seconds. #define RRAdjustTTL(ttl) ((ttl) + ((ttl)/4) + 2) #define RRUnadjustedTTL(ttl) ((((ttl) - 2) * 4) / 5) #define MaxUnansweredQueries 4 // SameResourceRecordSignature returns true if two resources records have the same name, type, and class, and may be sent // (or were received) on the same interface (i.e. if *both* records specify an interface, then it has to match). // TTL and rdata may differ. // This is used for cache flush management: // When sending a unique record, all other records matching "SameResourceRecordSignature" must also be sent // When receiving a unique record, all old cache records matching "SameResourceRecordSignature" are flushed // SameResourceRecordNameClassInterface is functionally the same as SameResourceRecordSignature, except rrtype does not have to match #define SameResourceRecordSignature(A,B) (A)->resrec.rrtype == (B)->resrec.rrtype && SameResourceRecordNameClassInterface((A),(B)) mDNSlocal mDNSBool SameResourceRecordNameClassInterface(const AuthRecord *const r1, const AuthRecord *const r2) { if (!r1) { LogMsg("SameResourceRecordSignature ERROR: r1 is NULL"); return(mDNSfalse); } if (!r2) { LogMsg("SameResourceRecordSignature ERROR: r2 is NULL"); return(mDNSfalse); } if (r1->resrec.InterfaceID && r2->resrec.InterfaceID && r1->resrec.InterfaceID != r2->resrec.InterfaceID) return(mDNSfalse); return (mDNSBool)( r1->resrec.rrclass == r2->resrec.rrclass && r1->resrec.namehash == r2->resrec.namehash && SameDomainName(r1->resrec.name, r2->resrec.name)); } // PacketRRMatchesSignature behaves as SameResourceRecordSignature, except that types may differ if our // authoratative record is unique (as opposed to shared). For unique records, we are supposed to have // complete ownership of *all* types for this name, so *any* record type with the same name is a conflict. // In addition, when probing we send our questions with the wildcard type kDNSQType_ANY, // so a response of any type should match, even if it is not actually the type the client plans to use. // For now, to make it easier to avoid false conflicts, we treat SPS Proxy records like shared records, // and require the rrtypes to match for the rdata to be considered potentially conflicting mDNSlocal mDNSBool PacketRRMatchesSignature(const CacheRecord *const pktrr, const AuthRecord *const authrr) { if (!pktrr) { LogMsg("PacketRRMatchesSignature ERROR: pktrr is NULL"); return(mDNSfalse); } if (!authrr) { LogMsg("PacketRRMatchesSignature ERROR: authrr is NULL"); return(mDNSfalse); } if (pktrr->resrec.InterfaceID && authrr->resrec.InterfaceID && pktrr->resrec.InterfaceID != authrr->resrec.InterfaceID) return(mDNSfalse); if (!(authrr->resrec.RecordType & kDNSRecordTypeUniqueMask) || authrr->WakeUp.HMAC.l[0]) if (pktrr->resrec.rrtype != authrr->resrec.rrtype) return(mDNSfalse); if ((authrr->resrec.InterfaceID == mDNSInterface_Any) && !mDNSPlatformValidRecordForInterface(authrr, pktrr->resrec.InterfaceID)) return(mDNSfalse); return (mDNSBool)( pktrr->resrec.rrclass == authrr->resrec.rrclass && pktrr->resrec.namehash == authrr->resrec.namehash && SameDomainName(pktrr->resrec.name, authrr->resrec.name)); } // CacheRecord *ka is the CacheRecord from the known answer list in the query. // This is the information that the requester believes to be correct. // AuthRecord *rr is the answer we are proposing to give, if not suppressed. // This is the information that we believe to be correct. // We've already determined that we plan to give this answer on this interface // (either the record is non-specific, or it is specific to this interface) // so now we just need to check the name, type, class, rdata and TTL. mDNSlocal mDNSBool ShouldSuppressKnownAnswer(const CacheRecord *const ka, const AuthRecord *const rr) { // If RR signature is different, or data is different, then don't suppress our answer if (!IdenticalResourceRecord(&ka->resrec, &rr->resrec)) return(mDNSfalse); // If the requester's indicated TTL is less than half the real TTL, // we need to give our answer before the requester's copy expires. // If the requester's indicated TTL is at least half the real TTL, // then we can suppress our answer this time. // If the requester's indicated TTL is greater than the TTL we believe, // then that's okay, and we don't need to do anything about it. // (If two responders on the network are offering the same information, // that's okay, and if they are offering the information with different TTLs, // the one offering the lower TTL should defer to the one offering the higher TTL.) return (mDNSBool)(ka->resrec.rroriginalttl >= rr->resrec.rroriginalttl / 2); } mDNSlocal void SetNextAnnounceProbeTime(mDNS *const m, const AuthRecord *const rr) { if (rr->resrec.RecordType == kDNSRecordTypeUnique) { if ((rr->LastAPTime + rr->ThisAPInterval) - m->timenow > mDNSPlatformOneSecond * 10) { LogMsg("SetNextAnnounceProbeTime: ProbeCount %d Next in %d %s", rr->ProbeCount, (rr->LastAPTime + rr->ThisAPInterval) - m->timenow, ARDisplayString(m, rr)); LogMsg("SetNextAnnounceProbeTime: m->SuppressProbes %d m->timenow %d diff %d", m->SuppressProbes, m->timenow, m->SuppressProbes - m->timenow); } if (m->NextScheduledProbe - (rr->LastAPTime + rr->ThisAPInterval) >= 0) m->NextScheduledProbe = (rr->LastAPTime + rr->ThisAPInterval); // Some defensive code: // If (rr->LastAPTime + rr->ThisAPInterval) happens to be far in the past, we don't want to allow // NextScheduledProbe to be set excessively in the past, because that can cause bad things to happen. // See: mDNS: Sometimes advertising stops working and record interval is set to zero if (m->NextScheduledProbe - m->timenow < 0) m->NextScheduledProbe = m->timenow; } else if (rr->AnnounceCount && (ResourceRecordIsValidAnswer(rr) || rr->resrec.RecordType == kDNSRecordTypeDeregistering)) { if (m->NextScheduledResponse - (rr->LastAPTime + rr->ThisAPInterval) >= 0) m->NextScheduledResponse = (rr->LastAPTime + rr->ThisAPInterval); } } mDNSlocal void InitializeLastAPTime(mDNS *const m, AuthRecord *const rr) { // For reverse-mapping Sleep Proxy PTR records, probe interval is one second rr->ThisAPInterval = rr->AddressProxy.type ? mDNSPlatformOneSecond : DefaultAPIntervalForRecordType(rr->resrec.RecordType); // * If this is a record type that's going to probe, then we use the m->SuppressProbes time. // * Otherwise, if it's not going to probe, but m->SuppressProbes is set because we have other // records that are going to probe, then we delay its first announcement so that it will // go out synchronized with the first announcement for the other records that *are* probing. // This is a minor performance tweak that helps keep groups of related records synchronized together. // The addition of "interval / 2" is to make sure that, in the event that any of the probes are // delayed by a few milliseconds, this announcement does not inadvertently go out *before* the probing is complete. // When the probing is complete and those records begin to announce, these records will also be picked up and accelerated, // because they will meet the criterion of being at least half-way to their scheduled announcement time. // * If it's not going to probe and m->SuppressProbes is not already set then we should announce immediately. if (rr->ProbeCount) { rr->ProbingConflictCount = 0; // If we have no probe suppression time set, or it is in the past, set it now if (m->SuppressProbes == 0 || m->SuppressProbes - m->timenow < 0) { // To allow us to aggregate probes when a group of services are registered together, // the first probe is delayed by a random delay in the range 1/8 to 1/4 second. // This means the common-case behaviour is: // randomized wait; probe // 1/4 second wait; probe // 1/4 second wait; probe // 1/4 second wait; announce (i.e. service is normally announced 7/8 to 1 second after being registered) m->SuppressProbes = NonZeroTime(m->timenow + DefaultProbeIntervalForTypeUnique/2 + mDNSRandom(DefaultProbeIntervalForTypeUnique/2)); // If we already have a *probe* scheduled to go out sooner, then use that time to get better aggregation if (m->SuppressProbes - m->NextScheduledProbe >= 0) m->SuppressProbes = NonZeroTime(m->NextScheduledProbe); if (m->SuppressProbes - m->timenow < 0) // Make sure we don't set m->SuppressProbes excessively in the past m->SuppressProbes = m->timenow; // If we already have a *query* scheduled to go out sooner, then use that time to get better aggregation if (m->SuppressProbes - m->NextScheduledQuery >= 0) m->SuppressProbes = NonZeroTime(m->NextScheduledQuery); if (m->SuppressProbes - m->timenow < 0) // Make sure we don't set m->SuppressProbes excessively in the past m->SuppressProbes = m->timenow; // except... don't expect to be able to send before the m->SuppressSending timer fires if (m->SuppressSending && m->SuppressProbes - m->SuppressSending < 0) m->SuppressProbes = NonZeroTime(m->SuppressSending); if (m->SuppressProbes - m->timenow > mDNSPlatformOneSecond * 8) { LogMsg("InitializeLastAPTime ERROR m->SuppressProbes %d m->NextScheduledProbe %d m->NextScheduledQuery %d m->SuppressSending %d %d", m->SuppressProbes - m->timenow, m->NextScheduledProbe - m->timenow, m->NextScheduledQuery - m->timenow, m->SuppressSending, m->SuppressSending - m->timenow); m->SuppressProbes = NonZeroTime(m->timenow + DefaultProbeIntervalForTypeUnique/2 + mDNSRandom(DefaultProbeIntervalForTypeUnique/2)); } } rr->LastAPTime = m->SuppressProbes - rr->ThisAPInterval; } // Skip kDNSRecordTypeKnownUnique and kDNSRecordTypeShared records here and set their LastAPTime in the "else" block below so // that they get announced immediately, otherwise, their announcement would be delayed until the based on the SuppressProbes value. else if ((rr->resrec.RecordType != kDNSRecordTypeKnownUnique) && (rr->resrec.RecordType != kDNSRecordTypeShared) && m->SuppressProbes && (m->SuppressProbes - m->timenow >= 0)) rr->LastAPTime = m->SuppressProbes - rr->ThisAPInterval + DefaultProbeIntervalForTypeUnique * DefaultProbeCountForTypeUnique + rr->ThisAPInterval / 2; else rr->LastAPTime = m->timenow - rr->ThisAPInterval; // For reverse-mapping Sleep Proxy PTR records we don't want to start probing instantly -- we // wait one second to give the client a chance to go to sleep, and then start our ARP/NDP probing. // After three probes one second apart with no answer, we conclude the client is now sleeping // and we can begin broadcasting our announcements to take over ownership of that IP address. // If we don't wait for the client to go to sleep, then when the client sees our ARP Announcements there's a risk // (depending on the OS and networking stack it's using) that it might interpret it as a conflict and change its IP address. if (rr->AddressProxy.type) rr->LastAPTime = m->timenow; // Set LastMCTime to now, to inhibit multicast responses // (no need to send additional multicast responses when we're announcing anyway) rr->LastMCTime = m->timenow; rr->LastMCInterface = mDNSInterfaceMark; SetNextAnnounceProbeTime(m, rr); } mDNSlocal const domainname *SetUnicastTargetToHostName(mDNS *const m, AuthRecord *rr) { const domainname *target; if (rr->AutoTarget) { rr->AutoTarget = Target_AutoHostAndNATMAP; } target = GetServiceTarget(m, rr); if (!target || target->c[0] == 0) { // defer registration until we've got a target LogInfo("SetUnicastTargetToHostName No target for %s", ARDisplayString(m, rr)); rr->state = regState_NoTarget; return mDNSNULL; } else { LogInfo("SetUnicastTargetToHostName target %##s for resource record %s", target->c, ARDisplayString(m,rr)); return target; } } #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) mDNSlocal mDNSBool AuthRecordIncludesOrIsAWDL(const AuthRecord *const ar) { return ((AuthRecordIncludesAWDL(ar) || mDNSPlatformInterfaceIsAWDL(ar->resrec.InterfaceID)) ? mDNStrue : mDNSfalse); } #endif // Right now this only applies to mDNS (.local) services where the target host is always m->MulticastHostname // Eventually we should unify this with GetServiceTarget() in uDNS.c mDNSlocal void SetTargetToHostName(mDNS *const m, AuthRecord *const rr) { domainname *const target = GetRRDomainNameTarget(&rr->resrec); const domainname *newname; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (AuthRecordIncludesOrIsAWDL(rr)) { newname = &m->RandomizedHostname; } else #endif { newname = &m->MulticastHostname; } if (!target) LogInfo("SetTargetToHostName: Don't know how to set the target of rrtype %s", DNSTypeName(rr->resrec.rrtype)); if (!(rr->ForceMCast || rr->ARType == AuthRecordLocalOnly || rr->ARType == AuthRecordP2P || IsLocalDomain(&rr->namestorage))) { const domainname *const n = SetUnicastTargetToHostName(m, rr); if (n) newname = n; else { if (target) target->c[0] = 0; SetNewRData(&rr->resrec, mDNSNULL, 0); return; } } if (target && SameDomainName(target, newname)) debugf("SetTargetToHostName: Target of %##s is already %##s", rr->resrec.name->c, target->c); if (target && !SameDomainName(target, newname)) { AssignDomainName(target, newname); SetNewRData(&rr->resrec, mDNSNULL, 0); // Update rdlength, rdestimate, rdatahash // If we're in the middle of probing this record, we need to start again, // because changing its rdata may change the outcome of the tie-breaker. // (If the record type is kDNSRecordTypeUnique (unconfirmed unique) then DefaultProbeCountForRecordType is non-zero.) rr->ProbeCount = DefaultProbeCountForRecordType(rr->resrec.RecordType); // If we've announced this record, we really should send a goodbye packet for the old rdata before // changing to the new rdata. However, in practice, we only do SetTargetToHostName for unique records, // so when we announce them we'll set the kDNSClass_UniqueRRSet and clear any stale data that way. if (rr->RequireGoodbye && rr->resrec.RecordType == kDNSRecordTypeShared) debugf("Have announced shared record %##s (%s) at least once: should have sent a goodbye packet before updating", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); rr->AnnounceCount = InitialAnnounceCount; rr->RequireGoodbye = mDNSfalse; rr->ProbeRestartCount = 0; InitializeLastAPTime(m, rr); } } mDNSlocal void AcknowledgeRecord(mDNS *const m, AuthRecord *const rr) { if (rr->RecordCallback) { // CAUTION: MUST NOT do anything more with rr after calling rr->Callback(), because the client's callback function // is allowed to do anything, including starting/stopping queries, registering/deregistering records, etc. rr->Acknowledged = mDNStrue; mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback rr->RecordCallback(m, rr, mStatus_NoError); mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again } } mDNSexport void ActivateUnicastRegistration(mDNS *const m, AuthRecord *const rr) { // Make sure that we don't activate the SRV record and associated service records, if it is in // NoTarget state. First time when a service is being instantiated, SRV record may be in NoTarget state. // We should not activate any of the other reords (PTR, TXT) that are part of the service. When // the target becomes available, the records will be reregistered. if (rr->resrec.rrtype != kDNSType_SRV) { AuthRecord *srvRR = mDNSNULL; if (rr->resrec.rrtype == kDNSType_PTR) srvRR = rr->Additional1; else if (rr->resrec.rrtype == kDNSType_TXT) srvRR = rr->DependentOn; if (srvRR) { if (srvRR->resrec.rrtype != kDNSType_SRV) { LogMsg("ActivateUnicastRegistration: ERROR!! Resource record %s wrong, expecting SRV type", ARDisplayString(m, srvRR)); } else { LogInfo("ActivateUnicastRegistration: Found Service Record %s in state %d for %##s (%s)", ARDisplayString(m, srvRR), srvRR->state, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); rr->state = srvRR->state; } } } if (rr->state == regState_NoTarget) { LogInfo("ActivateUnicastRegistration record %s in regState_NoTarget, not activating", ARDisplayString(m, rr)); return; } // When we wake up from sleep, we call ActivateUnicastRegistration. It is possible that just before we went to sleep, // the service/record was being deregistered. In that case, we should not try to register again. For the cases where // the records are deregistered due to e.g., no target for the SRV record, we would have returned from above if it // was already in NoTarget state. If it was in the process of deregistration but did not complete fully before we went // to sleep, then it is okay to start in Pending state as we will go back to NoTarget state if we don't have a target. if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) { LogInfo("ActivateUnicastRegistration: Resource record %s, current state %d, moving to DeregPending", ARDisplayString(m, rr), rr->state); rr->state = regState_DeregPending; } else { LogInfo("ActivateUnicastRegistration: Resource record %s, current state %d, moving to Pending", ARDisplayString(m, rr), rr->state); rr->state = regState_Pending; } rr->ProbingConflictCount = 0; rr->LastConflictPktNum = 0; rr->ProbeRestartCount = 0; rr->ProbeCount = 0; rr->AnnounceCount = 0; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - rr->ThisAPInterval; rr->expire = 0; // Forget about all the leases, start fresh rr->uselease = mDNStrue; rr->updateid = zeroID; rr->SRVChanged = mDNSfalse; rr->updateError = mStatus_NoError; // RestartRecordGetZoneData calls this function whenever a new interface gets registered with core. // The records might already be registered with the server and hence could have NAT state. if (rr->NATinfo.clientContext) { mDNS_StopNATOperation_internal(m, &rr->NATinfo); rr->NATinfo.clientContext = mDNSNULL; } if (rr->nta) { CancelGetZoneData(m, rr->nta); rr->nta = mDNSNULL; } if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } if (m->NextuDNSEvent - (rr->LastAPTime + rr->ThisAPInterval) >= 0) m->NextuDNSEvent = (rr->LastAPTime + rr->ThisAPInterval); } // Two records qualify to be local duplicates if: // (a) the RecordTypes are the same, or // (b) one is Unique and the other Verified // (c) either is in the process of deregistering #define RecordLDT(A,B) ((A)->resrec.RecordType == (B)->resrec.RecordType || \ ((A)->resrec.RecordType | (B)->resrec.RecordType) == (kDNSRecordTypeUnique | kDNSRecordTypeVerified) || \ ((A)->resrec.RecordType == kDNSRecordTypeDeregistering || (B)->resrec.RecordType == kDNSRecordTypeDeregistering)) #define RecordIsLocalDuplicate(A,B) \ ((A)->resrec.InterfaceID == (B)->resrec.InterfaceID && RecordLDT((A),(B)) && IdenticalResourceRecord(& (A)->resrec, & (B)->resrec)) mDNSlocal AuthRecord *CheckAuthIdenticalRecord(AuthHash *r, AuthRecord *rr) { const AuthGroup *a; AuthRecord *rp; a = AuthGroupForRecord(r, &rr->resrec); if (!a) return mDNSNULL; rp = a->members; while (rp) { if (!RecordIsLocalDuplicate(rp, rr)) rp = rp->next; else { if (rp->resrec.RecordType == kDNSRecordTypeDeregistering) { rp->AnnounceCount = 0; rp = rp->next; } else return rp; } } return (mDNSNULL); } mDNSlocal mDNSBool CheckAuthRecordConflict(AuthHash *r, AuthRecord *rr) { const AuthGroup *a; const AuthRecord *rp; a = AuthGroupForRecord(r, &rr->resrec); if (!a) return mDNSfalse; rp = a->members; while (rp) { const AuthRecord *s1 = rr->RRSet ? rr->RRSet : rr; const AuthRecord *s2 = rp->RRSet ? rp->RRSet : rp; if (s1 != s2 && SameResourceRecordSignature(rp, rr) && !IdenticalSameNameRecord(&rp->resrec, &rr->resrec)) return mDNStrue; else rp = rp->next; } return (mDNSfalse); } // checks to see if "rr" is already present mDNSlocal AuthRecord *CheckAuthSameRecord(AuthHash *r, AuthRecord *rr) { const AuthGroup *a; AuthRecord *rp; a = AuthGroupForRecord(r, &rr->resrec); if (!a) return mDNSNULL; rp = a->members; while (rp) { if (rp != rr) rp = rp->next; else { return rp; } } return (mDNSNULL); } mDNSlocal void DecrementAutoTargetServices(mDNS *const m, AuthRecord *const rr) { if (RRLocalOnly(rr)) { // A sanity check, this should be prevented in calling code. LogInfo("DecrementAutoTargetServices: called for RRLocalOnly() record: %s", ARDisplayString(m, rr)); return; } if (!AuthRecord_uDNS(rr) && (rr->resrec.rrtype == kDNSType_SRV) && (rr->AutoTarget == Target_AutoHost)) { NetworkInterfaceInfo *intf; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) DeadvertiseFlags flags = 0; // DeadvertiseFlags for non-AWDL interfaces. DeadvertiseFlags flagsAWDL = 0; // DeadvertiseFlags for AWDL interfaces. if (AuthRecordIncludesOrIsAWDL(rr)) { if (AuthRecordIncludesAWDL(rr)) { m->AutoTargetAWDLIncludedCount--; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "DecrementAutoTargetServices: AutoTargetAWDLIncludedCount %u Record " PRI_S, m->AutoTargetAWDLIncludedCount, ARDisplayString(m, rr)); if (m->AutoTargetAWDLIncludedCount == 0) { flags |= kDeadvertiseFlag_RandHostname; if (m->AutoTargetAWDLOnlyCount == 0) flagsAWDL |= kDeadvertiseFlag_RandHostname; } } else { m->AutoTargetAWDLOnlyCount--; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "DecrementAutoTargetServices: AutoTargetAWDLOnlyCount %u Record " PRI_S, m->AutoTargetAWDLOnlyCount, ARDisplayString(m, rr)); if ((m->AutoTargetAWDLIncludedCount == 0) && (m->AutoTargetAWDLOnlyCount == 0)) { flagsAWDL |= kDeadvertiseFlag_RandHostname; } } if (flags || flagsAWDL) { for (intf = m->HostInterfaces; intf; intf = intf->next) { if (!intf->Advertise) continue; if (mDNSPlatformInterfaceIsAWDL(intf->InterfaceID)) { if (flagsAWDL) DeadvertiseInterface(m, intf, flagsAWDL); } else { if (flags) DeadvertiseInterface(m, intf, flags); } } } if ((m->AutoTargetAWDLIncludedCount == 0) && (m->AutoTargetAWDLOnlyCount == 0)) { GetRandomUUIDLocalHostname(&m->RandomizedHostname); } } else #endif { m->AutoTargetServices--; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "DecrementAutoTargetServices: AutoTargetServices %u Record " PRI_S, m->AutoTargetServices, ARDisplayString(m, rr)); if (m->AutoTargetServices == 0) { for (intf = m->HostInterfaces; intf; intf = intf->next) { if (intf->Advertise) DeadvertiseInterface(m, intf, kDeadvertiseFlag_NormalHostname); } } } } #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (!AuthRecord_uDNS(rr)) { if (m->NumAllInterfaceRecords + m->NumAllInterfaceQuestions == 1) m->NextBonjourDisableTime = NonZeroTime(m->timenow + (BONJOUR_DISABLE_DELAY * mDNSPlatformOneSecond)); m->NumAllInterfaceRecords--; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "DecrementAutoTargetServices: NumAllInterfaceRecords %u NumAllInterfaceQuestions %u " PRI_S, m->NumAllInterfaceRecords, m->NumAllInterfaceQuestions, ARDisplayString(m, rr)); } #endif } mDNSlocal void AdvertiseNecessaryInterfaceRecords(mDNS *const m) { NetworkInterfaceInfo *intf; for (intf = m->HostInterfaces; intf; intf = intf->next) { if (intf->Advertise) AdvertiseInterfaceIfNeeded(m, intf); } } mDNSlocal void IncrementAutoTargetServices(mDNS *const m, AuthRecord *const rr) { mDNSBool enablingBonjour = mDNSfalse; if (RRLocalOnly(rr)) { // A sanity check, this should be prevented in calling code. LogInfo("IncrementAutoTargetServices: called for RRLocalOnly() record: %s", ARDisplayString(m, rr)); return; } #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (!AuthRecord_uDNS(rr)) { m->NumAllInterfaceRecords++; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "IncrementAutoTargetServices: NumAllInterfaceRecords %u NumAllInterfaceQuestions %u " PRI_S, m->NumAllInterfaceRecords, m->NumAllInterfaceQuestions, ARDisplayString(m, rr)); if (m->NumAllInterfaceRecords + m->NumAllInterfaceQuestions == 1) { m->NextBonjourDisableTime = 0; if (m->BonjourEnabled == 0) { // Enable Bonjour immediately by scheduling network changed processing where // we will join the multicast group on each active interface. m->BonjourEnabled = 1; enablingBonjour = mDNStrue; m->NetworkChanged = m->timenow; } } } #endif if (!AuthRecord_uDNS(rr) && (rr->resrec.rrtype == kDNSType_SRV) && (rr->AutoTarget == Target_AutoHost)) { #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (AuthRecordIncludesAWDL(rr)) { m->AutoTargetAWDLIncludedCount++; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "IncrementAutoTargetServices: AutoTargetAWDLIncludedCount %u Record " PRI_S, m->AutoTargetAWDLIncludedCount, ARDisplayString(m, rr)); } else if (mDNSPlatformInterfaceIsAWDL(rr->resrec.InterfaceID)) { m->AutoTargetAWDLOnlyCount++; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "IncrementAutoTargetServices: AutoTargetAWDLOnlyCount %u Record " PRI_S, m->AutoTargetAWDLOnlyCount, ARDisplayString(m, rr)); } else #endif { m->AutoTargetServices++; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "IncrementAutoTargetServices: AutoTargetServices %u Record " PRI_S, m->AutoTargetServices, ARDisplayString(m, rr)); } // If this is the first advertised service and we did not just enable Bonjour above, then // advertise all the interface records. If we did enable Bonjour above, the interface records will // be advertised during the network changed processing scheduled above, so no need // to do it here. if (!enablingBonjour) AdvertiseNecessaryInterfaceRecords(m); } } mDNSlocal void getKeepaliveRaddr(mDNS *const m, AuthRecord *rr, mDNSAddr *raddr) { mDNSAddr laddr = zeroAddr; mDNSEthAddr eth = zeroEthAddr; mDNSIPPort lport = zeroIPPort; mDNSIPPort rport = zeroIPPort; mDNSu32 timeout = 0; mDNSu32 seq = 0; mDNSu32 ack = 0; mDNSu16 win = 0; if (mDNS_KeepaliveRecord(&rr->resrec)) { mDNS_ExtractKeepaliveInfo(rr, &timeout, &laddr, raddr, ð, &seq, &ack, &lport, &rport, &win); if (!timeout || mDNSAddressIsZero(&laddr) || mDNSAddressIsZero(raddr) || mDNSIPPortIsZero(lport) || mDNSIPPortIsZero(rport)) { LogMsg("getKeepaliveRaddr: not a valid record %s for keepalive %#a:%d %#a:%d", ARDisplayString(m, rr), &laddr, lport.NotAnInteger, raddr, rport.NotAnInteger); return; } } } // Exported so uDNS.c can call this mDNSexport mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr) { domainname *target = GetRRDomainNameTarget(&rr->resrec); AuthRecord *r; AuthRecord **p = &m->ResourceRecords; AuthRecord **d = &m->DuplicateRecords; if ((mDNSs32)rr->resrec.rroriginalttl <= 0) { LogMsg("mDNS_Register_internal: TTL %X should be 1 - 0x7FFFFFFF %s", rr->resrec.rroriginalttl, ARDisplayString(m, rr)); return(mStatus_BadParamErr); } if (!rr->resrec.RecordType) { LogMsg("mDNS_Register_internal: RecordType must be non-zero %s", ARDisplayString(m, rr)); return(mStatus_BadParamErr); } if (m->ShutdownTime) { LogMsg("mDNS_Register_internal: Shutting down, can't register %s", ARDisplayString(m, rr)); return(mStatus_ServiceNotRunning); } if (m->DivertMulticastAdvertisements && !AuthRecord_uDNS(rr)) { mDNSInterfaceID previousID = rr->resrec.InterfaceID; if (rr->resrec.InterfaceID == mDNSInterface_Any || rr->resrec.InterfaceID == mDNSInterface_P2P) { rr->resrec.InterfaceID = mDNSInterface_LocalOnly; rr->ARType = AuthRecordLocalOnly; } if (rr->resrec.InterfaceID != mDNSInterface_LocalOnly) { NetworkInterfaceInfo *intf = FirstInterfaceForID(m, rr->resrec.InterfaceID); if (intf && !intf->Advertise) { rr->resrec.InterfaceID = mDNSInterface_LocalOnly; rr->ARType = AuthRecordLocalOnly; } } if (rr->resrec.InterfaceID != previousID) LogInfo("mDNS_Register_internal: Diverting record to local-only %s", ARDisplayString(m, rr)); } if (RRLocalOnly(rr)) { if (CheckAuthSameRecord(&m->rrauth, rr)) { LogMsg("mDNS_Register_internal: ERROR!! Tried to register LocalOnly AuthRecord %p %##s (%s) that's already in the list", rr, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); return(mStatus_AlreadyRegistered); } } else { while (*p && *p != rr) p=&(*p)->next; if (*p) { LogMsg("mDNS_Register_internal: ERROR!! Tried to register AuthRecord %p %##s (%s) that's already in the list", rr, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); return(mStatus_AlreadyRegistered); } } while (*d && *d != rr) d=&(*d)->next; if (*d) { LogMsg("mDNS_Register_internal: ERROR!! Tried to register AuthRecord %p %##s (%s) that's already in the Duplicate list", rr, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); return(mStatus_AlreadyRegistered); } if (rr->DependentOn) { if (rr->resrec.RecordType == kDNSRecordTypeUnique) rr->resrec.RecordType = kDNSRecordTypeVerified; else if (rr->resrec.RecordType != kDNSRecordTypeKnownUnique) { LogMsg("mDNS_Register_internal: ERROR! %##s (%s): rr->DependentOn && RecordType != kDNSRecordTypeUnique or kDNSRecordTypeKnownUnique", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); return(mStatus_Invalid); } if (!(rr->DependentOn->resrec.RecordType & (kDNSRecordTypeUnique | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique))) { LogMsg("mDNS_Register_internal: ERROR! %##s (%s): rr->DependentOn->RecordType bad type %X", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), rr->DependentOn->resrec.RecordType); return(mStatus_Invalid); } } rr->next = mDNSNULL; // Field Group 1: The actual information pertaining to this resource record // Set up by client prior to call // Field Group 2: Persistent metadata for Authoritative Records // rr->Additional1 = set to mDNSNULL in mDNS_SetupResourceRecord; may be overridden by client // rr->Additional2 = set to mDNSNULL in mDNS_SetupResourceRecord; may be overridden by client // rr->DependentOn = set to mDNSNULL in mDNS_SetupResourceRecord; may be overridden by client // rr->RRSet = set to mDNSNULL in mDNS_SetupResourceRecord; may be overridden by client // rr->Callback = already set in mDNS_SetupResourceRecord // rr->Context = already set in mDNS_SetupResourceRecord // rr->RecordType = already set in mDNS_SetupResourceRecord // rr->HostTarget = set to mDNSfalse in mDNS_SetupResourceRecord; may be overridden by client // rr->AllowRemoteQuery = set to mDNSfalse in mDNS_SetupResourceRecord; may be overridden by client // Make sure target is not uninitialized data, or we may crash writing debugging log messages if (rr->AutoTarget && target) target->c[0] = 0; // Field Group 3: Transient state for Authoritative Records rr->Acknowledged = mDNSfalse; rr->ProbeCount = DefaultProbeCountForRecordType(rr->resrec.RecordType); rr->ProbeRestartCount = 0; rr->AnnounceCount = InitialAnnounceCount; rr->RequireGoodbye = mDNSfalse; rr->AnsweredLocalQ = mDNSfalse; rr->IncludeInProbe = mDNSfalse; rr->ImmedUnicast = mDNSfalse; rr->SendNSECNow = mDNSNULL; rr->ImmedAnswer = mDNSNULL; rr->ImmedAdditional = mDNSNULL; rr->SendRNow = mDNSNULL; rr->v4Requester = zerov4Addr; rr->v6Requester = zerov6Addr; rr->NextResponse = mDNSNULL; rr->NR_AnswerTo = mDNSNULL; rr->NR_AdditionalTo = mDNSNULL; if (!rr->AutoTarget) InitializeLastAPTime(m, rr); // rr->LastAPTime = Set for us in InitializeLastAPTime() // rr->LastMCTime = Set for us in InitializeLastAPTime() // rr->LastMCInterface = Set for us in InitializeLastAPTime() rr->NewRData = mDNSNULL; rr->newrdlength = 0; rr->UpdateCallback = mDNSNULL; rr->UpdateCredits = kMaxUpdateCredits; rr->NextUpdateCredit = 0; rr->UpdateBlocked = 0; // For records we're holding as proxy (except reverse-mapping PTR records) two announcements is sufficient if (rr->WakeUp.HMAC.l[0] && !rr->AddressProxy.type) rr->AnnounceCount = 2; // Field Group 4: Transient uDNS state for Authoritative Records rr->state = regState_Zero; rr->uselease = 0; rr->expire = 0; rr->Private = 0; rr->updateid = zeroID; rr->updateIntID = zeroOpaque64; rr->zone = rr->resrec.name; rr->nta = mDNSNULL; rr->tcp = mDNSNULL; rr->OrigRData = 0; rr->OrigRDLen = 0; rr->InFlightRData = 0; rr->InFlightRDLen = 0; rr->QueuedRData = 0; rr->QueuedRDLen = 0; //mDNSPlatformMemZero(&rr->NATinfo, sizeof(rr->NATinfo)); // We should be recording the actual internal port for this service record here. Once we initiate our NAT mapping // request we'll subsequently overwrite srv.port with the allocated external NAT port -- potentially multiple // times with different values if the external NAT port changes during the lifetime of the service registration. //if (rr->resrec.rrtype == kDNSType_SRV) rr->NATinfo.IntPort = rr->resrec.rdata->u.srv.port; // rr->resrec.interface = already set in mDNS_SetupResourceRecord // rr->resrec.name->c = MUST be set by client // rr->resrec.rrtype = already set in mDNS_SetupResourceRecord // rr->resrec.rrclass = already set in mDNS_SetupResourceRecord // rr->resrec.rroriginalttl = already set in mDNS_SetupResourceRecord // rr->resrec.rdata = MUST be set by client, unless record type is CNAME or PTR and rr->HostTarget is set // BIND named (name daemon) doesn't allow TXT records with zero-length rdata. This is strictly speaking correct, // since RFC 1035 specifies a TXT record as "One or more s", not "Zero or more s". // Since some legacy apps try to create zero-length TXT records, we'll silently correct it here. if (rr->resrec.rrtype == kDNSType_TXT && rr->resrec.rdlength == 0) { rr->resrec.rdlength = 1; rr->resrec.rdata->u.txt.c[0] = 0; } if (rr->AutoTarget) { SetTargetToHostName(m, rr); // Also sets rdlength and rdestimate for us, and calls InitializeLastAPTime(); #ifndef UNICAST_DISABLED // If we have no target record yet, SetTargetToHostName will set rr->state == regState_NoTarget // In this case we leave the record half-formed in the list, and later we'll remove it from the list and re-add it properly. if (rr->state == regState_NoTarget) { // Initialize the target so that we don't crash while logging etc. domainname *tar = GetRRDomainNameTarget(&rr->resrec); if (tar) tar->c[0] = 0; LogInfo("mDNS_Register_internal: record %s in NoTarget state", ARDisplayString(m, rr)); } #endif } else { rr->resrec.rdlength = GetRDLength(&rr->resrec, mDNSfalse); rr->resrec.rdestimate = GetRDLength(&rr->resrec, mDNStrue); } if (!ValidateDomainName(rr->resrec.name)) { LogMsg("Attempt to register record with invalid name: %s", ARDisplayString(m, rr)); return(mStatus_Invalid); } // Don't do this until *after* we've set rr->resrec.rdlength if (!ValidateRData(rr->resrec.rrtype, rr->resrec.rdlength, rr->resrec.rdata)) { LogMsg("Attempt to register record with invalid rdata: %s", ARDisplayString(m, rr)); return(mStatus_Invalid); } rr->resrec.namehash = DomainNameHashValue(rr->resrec.name); rr->resrec.rdatahash = target ? DomainNameHashValue(target) : RDataHashValue(&rr->resrec); if (RRLocalOnly(rr)) { // If this is supposed to be unique, make sure we don't have any name conflicts. // If we found a conflict, we may still want to insert the record in the list but mark it appropriately // (kDNSRecordTypeDeregistering) so that we deliver RMV events to the application. But this causes more // complications and not clear whether there are any benefits. See rdar:9304275 for details. // Hence, just bail out. // This comment is doesn’t make any sense. -- SC if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) { if (CheckAuthRecordConflict(&m->rrauth, rr)) { LogInfo("mDNS_Register_internal: Name conflict %s (%p), InterfaceID %p", ARDisplayString(m, rr), rr, rr->resrec.InterfaceID); return mStatus_NameConflict; } } } // For uDNS records, we don't support duplicate checks at this time. #ifndef UNICAST_DISABLED if (AuthRecord_uDNS(rr)) { if (!m->NewLocalRecords) m->NewLocalRecords = rr; // When we called SetTargetToHostName, it may have caused mDNS_Register_internal to be re-entered, appending new // records to the list, so we now need to update p to advance to the new end to the list before appending our new record. while (*p) p=&(*p)->next; *p = rr; if (rr->resrec.RecordType == kDNSRecordTypeUnique) rr->resrec.RecordType = kDNSRecordTypeVerified; rr->ProbeCount = 0; rr->ProbeRestartCount = 0; rr->AnnounceCount = 0; if (rr->state != regState_NoTarget) ActivateUnicastRegistration(m, rr); return(mStatus_NoError); // <--- Note: For unicast records, code currently bails out at this point } #endif // Now that we've finished building our new record, make sure it's not identical to one we already have if (RRLocalOnly(rr)) { rr->ProbeCount = 0; rr->ProbeRestartCount = 0; rr->AnnounceCount = 0; r = CheckAuthIdenticalRecord(&m->rrauth, rr); } else { for (r = m->ResourceRecords; r; r=r->next) if (RecordIsLocalDuplicate(r, rr)) { if (r->resrec.RecordType == kDNSRecordTypeDeregistering) r->AnnounceCount = 0; else break; } } if (r) { LogInfo("mDNS_Register_internal: Adding to duplicate list %s", ARDisplayString(m,rr)); *d = rr; // If the previous copy of this record is already verified unique, // then indicate that we should move this record promptly to kDNSRecordTypeUnique state. // Setting ProbeCount to zero will cause SendQueries() to advance this record to // kDNSRecordTypeVerified state and call the client callback at the next appropriate time. if (rr->resrec.RecordType == kDNSRecordTypeUnique && r->resrec.RecordType == kDNSRecordTypeVerified) rr->ProbeCount = 0; } else { LogInfo("mDNS_Register_internal: Adding to active record list %s", ARDisplayString(m,rr)); if (RRLocalOnly(rr)) { AuthGroup *ag; ag = InsertAuthRecord(m, &m->rrauth, rr); if (ag && !ag->NewLocalOnlyRecords) { m->NewLocalOnlyRecords = mDNStrue; ag->NewLocalOnlyRecords = rr; } // No probing for LocalOnly records; acknowledge them right away if (rr->resrec.RecordType == kDNSRecordTypeUnique) rr->resrec.RecordType = kDNSRecordTypeVerified; AcknowledgeRecord(m, rr); return(mStatus_NoError); } else { if (!m->NewLocalRecords) m->NewLocalRecords = rr; *p = rr; } } if (!AuthRecord_uDNS(rr)) // This check is superfluous, given that for unicast records we (currently) bail out above { // We have inserted the record in the list. See if we have to advertise the A/AAAA, HINFO, PTR records. IncrementAutoTargetServices(m, rr); // For records that are not going to probe, acknowledge them right away if (rr->resrec.RecordType != kDNSRecordTypeUnique && rr->resrec.RecordType != kDNSRecordTypeDeregistering) AcknowledgeRecord(m, rr); // Adding a record may affect whether or not we should sleep mDNS_UpdateAllowSleep(m); } // If this is a non-sleep proxy keepalive record, fetch the MAC address of the remote host. // This is used by the in-NIC proxy to send the keepalive packets. if (!rr->WakeUp.HMAC.l[0] && mDNS_KeepaliveRecord(&rr->resrec)) { mDNSAddr raddr; // Set the record type to known unique to prevent probing keep alive records. // Also make sure we do not announce the keepalive records. rr->resrec.RecordType = kDNSRecordTypeKnownUnique; rr->AnnounceCount = 0; getKeepaliveRaddr(m, rr, &raddr); // This is an asynchronous call. Once the remote MAC address is available, helper will schedule an // asynchronous task to update the resource record mDNSPlatformGetRemoteMacAddr(&raddr); } return(mStatus_NoError); } mDNSlocal void RecordProbeFailure(mDNS *const m, const AuthRecord *const rr) { m->ProbeFailTime = m->timenow; m->NumFailedProbes++; // If we've had fifteen or more probe failures, rate-limit to one every five seconds. // If a bunch of hosts have all been configured with the same name, then they'll all // conflict and run through the same series of names: name-2, name-3, name-4, etc., // up to name-10. After that they'll start adding random increments in the range 1-100, // so they're more likely to branch out in the available namespace and settle on a set of // unique names quickly. If after five more tries the host is still conflicting, then we // may have a serious problem, so we start rate-limiting so we don't melt down the network. if (m->NumFailedProbes >= 15) { m->SuppressProbes = NonZeroTime(m->timenow + mDNSPlatformOneSecond * 5); LogMsg("Excessive name conflicts (%lu) for %##s (%s); rate limiting in effect", m->NumFailedProbes, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); } } mDNSlocal void CompleteRDataUpdate(mDNS *const m, AuthRecord *const rr) { RData *OldRData = rr->resrec.rdata; mDNSu16 OldRDLen = rr->resrec.rdlength; SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength); // Update our rdata rr->NewRData = mDNSNULL; // Clear the NewRData pointer ... if (rr->UpdateCallback) rr->UpdateCallback(m, rr, OldRData, OldRDLen); // ... and let the client know } // Note: mDNS_Deregister_internal can call a user callback, which may change the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. // Exported so uDNS.c can call this mDNSexport mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt) { AuthRecord *r2; mDNSu8 RecordType = rr->resrec.RecordType; AuthRecord **p = &m->ResourceRecords; // Find this record in our list of active records mDNSBool dupList = mDNSfalse; if (RRLocalOnly(rr)) { AuthGroup *a; AuthRecord **rp; a = AuthGroupForRecord(&m->rrauth, &rr->resrec); if (!a) return mDNSfalse; rp = &a->members; while (*rp && *rp != rr) rp=&(*rp)->next; p = rp; } else { while (*p && *p != rr) p=&(*p)->next; } if (*p) { // We found our record on the main list. See if there are any duplicates that need special handling. if (drt == mDNS_Dereg_conflict) // If this was a conflict, see that all duplicates get the same treatment { // Scan for duplicates of rr, and mark them for deregistration at the end of this routine, after we've finished // deregistering rr. We need to do this scan *before* we give the client the chance to free and reuse the rr memory. for (r2 = m->DuplicateRecords; r2; r2=r2->next) if (RecordIsLocalDuplicate(r2, rr)) r2->ProbeCount = 0xFF; } else { // Before we delete the record (and potentially send a goodbye packet) // first see if we have a record on the duplicate list ready to take over from it. AuthRecord **d = &m->DuplicateRecords; while (*d && !RecordIsLocalDuplicate(*d, rr)) d=&(*d)->next; if (*d) { AuthRecord *dup = *d; debugf("mDNS_Register_internal: Duplicate record %p taking over from %p %##s (%s)", dup, rr, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); *d = dup->next; // Cut replacement record from DuplicateRecords list if (RRLocalOnly(rr)) { dup->next = mDNSNULL; if (!InsertAuthRecord(m, &m->rrauth, dup)) LogMsg("mDNS_Deregister_internal: ERROR!! cannot insert %s", ARDisplayString(m, dup)); } else { dup->next = rr->next; // And then... rr->next = dup; // ... splice it in right after the record we're about to delete } dup->resrec.RecordType = rr->resrec.RecordType; dup->ProbeCount = rr->ProbeCount; dup->ProbeRestartCount = rr->ProbeRestartCount; dup->AnnounceCount = rr->AnnounceCount; dup->RequireGoodbye = rr->RequireGoodbye; dup->AnsweredLocalQ = rr->AnsweredLocalQ; dup->ImmedAnswer = rr->ImmedAnswer; dup->ImmedUnicast = rr->ImmedUnicast; dup->ImmedAdditional = rr->ImmedAdditional; dup->v4Requester = rr->v4Requester; dup->v6Requester = rr->v6Requester; dup->ThisAPInterval = rr->ThisAPInterval; dup->LastAPTime = rr->LastAPTime; dup->LastMCTime = rr->LastMCTime; dup->LastMCInterface = rr->LastMCInterface; dup->Private = rr->Private; dup->state = rr->state; rr->RequireGoodbye = mDNSfalse; rr->AnsweredLocalQ = mDNSfalse; } } } else { // We didn't find our record on the main list; try the DuplicateRecords list instead. p = &m->DuplicateRecords; while (*p && *p != rr) p=&(*p)->next; // If we found our record on the duplicate list, then make sure we don't send a goodbye for it if (*p) { // Duplicate records are not used for sending wakeups or goodbyes. Hence, deregister them // immediately. When there is a conflict, we deregister all the conflicting duplicate records // also that have been marked above in this function. In that case, we come here and if we don't // deregister (unilink from the DuplicateRecords list), we will be recursing infinitely. Hence, // clear the HMAC which will cause it to deregister. See for // details. rr->WakeUp.HMAC = zeroEthAddr; rr->RequireGoodbye = mDNSfalse; rr->resrec.RecordType = kDNSRecordTypeDeregistering; dupList = mDNStrue; } if (*p) debugf("mDNS_Deregister_internal: Deleting DuplicateRecord %p %##s (%s)", rr, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); } if (!*p) { // No need to log an error message if we already know this is a potentially repeated deregistration if (drt != mDNS_Dereg_repeat) LogMsg("mDNS_Deregister_internal: Record %p not found in list %s", rr, ARDisplayString(m,rr)); return(mStatus_BadReferenceErr); } // If this is a shared record and we've announced it at least once, // we need to retract that announcement before we delete the record // If this is a record (including mDNSInterface_LocalOnly records) for which we've given local-only answers then // it's tempting to just do "AnswerAllLocalQuestionsWithLocalAuthRecord(m, rr, QC_rmv)" here, but that would not not be safe. // The AnswerAllLocalQuestionsWithLocalAuthRecord routine walks the question list invoking client callbacks, using the "m->CurrentQuestion" // mechanism to cope with the client callback modifying the question list while that's happening. // However, mDNS_Deregister could have been called from a client callback (e.g. from the domain enumeration callback FoundDomain) // which means that the "m->CurrentQuestion" mechanism is already in use to protect that list, so we can't use it twice. // More generally, if we invoke callbacks from within a client callback, then those callbacks could deregister other // records, thereby invoking yet more callbacks, without limit. // The solution is to defer delivering the "Remove" events until mDNS_Execute time, just like we do for sending // actual goodbye packets. #ifndef UNICAST_DISABLED if (AuthRecord_uDNS(rr)) { if (rr->RequireGoodbye) { if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } rr->resrec.RecordType = kDNSRecordTypeDeregistering; m->LocalRemoveEvents = mDNStrue; uDNS_DeregisterRecord(m, rr); // At this point unconditionally we bail out // Either uDNS_DeregisterRecord will have completed synchronously, and called CompleteDeregistration, // which calls us back here with RequireGoodbye set to false, or it will have initiated the deregistration // process and will complete asynchronously. Either way we don't need to do anything more here. return(mStatus_NoError); } // Sometimes the records don't complete proper deregistration i.e., don't wait for a response // from the server. In that case, if the records have been part of a group update, clear the // state here. rr->updateid = zeroID; // We defer cleaning up NAT state only after sending goodbyes. This is important because // RecordRegistrationGotZoneData guards against creating NAT state if clientContext is non-NULL. // This happens today when we turn on/off interface where we get multiple network transitions // and RestartRecordGetZoneData triggers re-registration of the resource records even though // they may be in Registered state which causes NAT information to be setup multiple times. Defering // the cleanup here keeps clientContext non-NULL and hence prevents that. Note that cleaning up // NAT state here takes care of the case where we did not send goodbyes at all. if (rr->NATinfo.clientContext) { mDNS_StopNATOperation_internal(m, &rr->NATinfo); rr->NATinfo.clientContext = mDNSNULL; } if (rr->nta) { CancelGetZoneData(m, rr->nta); rr->nta = mDNSNULL; } if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } } #endif // UNICAST_DISABLED if (RecordType == kDNSRecordTypeUnregistered) LogMsg("mDNS_Deregister_internal: %s already marked kDNSRecordTypeUnregistered", ARDisplayString(m, rr)); else if (RecordType == kDNSRecordTypeDeregistering) { LogMsg("mDNS_Deregister_internal: %s already marked kDNSRecordTypeDeregistering", ARDisplayString(m, rr)); return(mStatus_BadReferenceErr); } if (rr->WakeUp.HMAC.l[0] || (((RecordType == kDNSRecordTypeShared) || (rr->ARType == AuthRecordLocalOnly)) && (rr->RequireGoodbye || rr->AnsweredLocalQ))) { verbosedebugf("mDNS_Deregister_internal: Starting deregistration for %s", ARDisplayString(m, rr)); rr->resrec.RecordType = kDNSRecordTypeDeregistering; rr->resrec.rroriginalttl = 0; rr->AnnounceCount = rr->WakeUp.HMAC.l[0] ? WakeupCount : (drt == mDNS_Dereg_rapid) ? 1 : GoodbyeCount; rr->ThisAPInterval = mDNSPlatformOneSecond * 2; rr->LastAPTime = m->timenow - rr->ThisAPInterval; m->LocalRemoveEvents = mDNStrue; if (m->NextScheduledResponse - (m->timenow + mDNSPlatformOneSecond/10) >= 0) m->NextScheduledResponse = (m->timenow + mDNSPlatformOneSecond/10); } else { if (!dupList && RRLocalOnly(rr)) { AuthGroup *ag = RemoveAuthRecord(m, &m->rrauth, rr); if (ag->NewLocalOnlyRecords == rr) ag->NewLocalOnlyRecords = rr->next; } else { *p = rr->next; // Cut this record from the list if (m->NewLocalRecords == rr) m->NewLocalRecords = rr->next; DecrementAutoTargetServices(m, rr); } // If someone is about to look at this, bump the pointer forward if (m->CurrentRecord == rr) m->CurrentRecord = rr->next; rr->next = mDNSNULL; verbosedebugf("mDNS_Deregister_internal: Deleting record for %s", ARDisplayString(m, rr)); rr->resrec.RecordType = kDNSRecordTypeUnregistered; if ((drt == mDNS_Dereg_conflict || drt == mDNS_Dereg_repeat) && RecordType == kDNSRecordTypeShared) debugf("mDNS_Deregister_internal: Cannot have a conflict on a shared record! %##s (%s)", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); // If we have an update queued up which never executed, give the client a chance to free that memory if (rr->NewRData) CompleteRDataUpdate(m, rr); // Update our rdata, clear the NewRData pointer, and return memory to the client // CAUTION: MUST NOT do anything more with rr after calling rr->Callback(), because the client's callback function // is allowed to do anything, including starting/stopping queries, registering/deregistering records, etc. // In this case the likely client action to the mStatus_MemFree message is to free the memory, // so any attempt to touch rr after this is likely to lead to a crash. if (drt != mDNS_Dereg_conflict) { mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback LogInfo("mDNS_Deregister_internal: callback with mStatus_MemFree for %s", ARDisplayString(m, rr)); if (rr->RecordCallback) rr->RecordCallback(m, rr, mStatus_MemFree); // MUST NOT touch rr after this mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again } else { RecordProbeFailure(m, rr); mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback if (rr->RecordCallback) rr->RecordCallback(m, rr, mStatus_NameConflict); // MUST NOT touch rr after this mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again // Now that we've finished deregistering rr, check our DuplicateRecords list for any that we marked previously. // Note that with all the client callbacks going on, by the time we get here all the // records we marked may have been explicitly deregistered by the client anyway. r2 = m->DuplicateRecords; while (r2) { if (r2->ProbeCount != 0xFF) { r2 = r2->next; } else { #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) // See if this record was also registered with any D2D plugins. D2D_stop_advertising_record(r2); #endif mDNS_Deregister_internal(m, r2, mDNS_Dereg_conflict); // As this is a duplicate record, it will be unlinked from the list // immediately r2 = m->DuplicateRecords; } } } } mDNS_UpdateAllowSleep(m); return(mStatus_NoError); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Packet Sending Functions #endif mDNSlocal void AddRecordToResponseList(AuthRecord ***nrpp, AuthRecord *rr, AuthRecord *add) { if (rr->NextResponse == mDNSNULL && *nrpp != &rr->NextResponse) { **nrpp = rr; // NR_AdditionalTo must point to a record with NR_AnswerTo set (and not NR_AdditionalTo) // If 'add' does not meet this requirement, then follow its NR_AdditionalTo pointer to a record that does // The referenced record will definitely be acceptable (by recursive application of this rule) if (add && add->NR_AdditionalTo) add = add->NR_AdditionalTo; rr->NR_AdditionalTo = add; *nrpp = &rr->NextResponse; } debugf("AddRecordToResponseList: %##s (%s) already in list", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); } mDNSlocal void AddRRSetAdditionalsToResponseList(mDNS *const m, AuthRecord ***nrpp, AuthRecord *rr, AuthRecord *additional, const mDNSInterfaceID InterfaceID) { AuthRecord *rr2; if (additional->resrec.RecordType & kDNSRecordTypeUniqueMask) { for (rr2 = m->ResourceRecords; rr2; rr2 = rr2->next) { if ((rr2->resrec.namehash == additional->resrec.namehash) && (rr2->resrec.rrtype == additional->resrec.rrtype) && (rr2 != additional) && (rr2->resrec.RecordType & kDNSRecordTypeUniqueMask) && (rr2->resrec.rrclass == additional->resrec.rrclass) && ResourceRecordIsValidInterfaceAnswer(rr2, InterfaceID) && SameDomainName(rr2->resrec.name, additional->resrec.name)) { AddRecordToResponseList(nrpp, rr2, rr); } } } } mDNSlocal void AddAdditionalsToResponseList(mDNS *const m, AuthRecord *ResponseRecords, AuthRecord ***nrpp, const mDNSInterfaceID InterfaceID) { AuthRecord *rr, *rr2; for (rr=ResponseRecords; rr; rr=rr->NextResponse) // For each record we plan to put { // (Note: This is an "if", not a "while". If we add a record, we'll find it again // later in the "for" loop, and we will follow further "additional" links then.) if (rr->Additional1 && ResourceRecordIsValidInterfaceAnswer(rr->Additional1, InterfaceID)) { AddRecordToResponseList(nrpp, rr->Additional1, rr); AddRRSetAdditionalsToResponseList(m, nrpp, rr, rr->Additional1, InterfaceID); } if (rr->Additional2 && ResourceRecordIsValidInterfaceAnswer(rr->Additional2, InterfaceID)) { AddRecordToResponseList(nrpp, rr->Additional2, rr); AddRRSetAdditionalsToResponseList(m, nrpp, rr, rr->Additional2, InterfaceID); } // For SRV records, automatically add the Address record(s) for the target host if (rr->resrec.rrtype == kDNSType_SRV) { for (rr2=m->ResourceRecords; rr2; rr2=rr2->next) // Scan list of resource records if (RRTypeIsAddressType(rr2->resrec.rrtype) && // For all address records (A/AAAA) ... ResourceRecordIsValidInterfaceAnswer(rr2, InterfaceID) && // ... which are valid for answer ... rr->resrec.rdatahash == rr2->resrec.namehash && // ... whose name is the name of the SRV target SameDomainName(&rr->resrec.rdata->u.srv.target, rr2->resrec.name)) AddRecordToResponseList(nrpp, rr2, rr); } else if (RRTypeIsAddressType(rr->resrec.rrtype)) // For A or AAAA, put counterpart as additional { for (rr2=m->ResourceRecords; rr2; rr2=rr2->next) // Scan list of resource records if (RRTypeIsAddressType(rr2->resrec.rrtype) && // For all address records (A/AAAA) ... ResourceRecordIsValidInterfaceAnswer(rr2, InterfaceID) && // ... which are valid for answer ... rr->resrec.namehash == rr2->resrec.namehash && // ... and have the same name SameDomainName(rr->resrec.name, rr2->resrec.name)) AddRecordToResponseList(nrpp, rr2, rr); } else if (rr->resrec.rrtype == kDNSType_PTR) // For service PTR, see if we want to add DeviceInfo record { if (ResourceRecordIsValidInterfaceAnswer(&m->DeviceInfo, InterfaceID) && SameDomainLabel(rr->resrec.rdata->u.name.c, m->DeviceInfo.resrec.name->c)) AddRecordToResponseList(nrpp, &m->DeviceInfo, rr); } } } mDNSlocal void SendDelayedUnicastResponse(mDNS *const m, const mDNSAddr *const dest, const mDNSInterfaceID InterfaceID) { AuthRecord *rr; AuthRecord *ResponseRecords = mDNSNULL; AuthRecord **nrp = &ResponseRecords; NetworkInterfaceInfo *intf = FirstInterfaceForID(m, InterfaceID); // Make a list of all our records that need to be unicast to this destination for (rr = m->ResourceRecords; rr; rr=rr->next) { // If we find we can no longer unicast this answer, clear ImmedUnicast if (rr->ImmedAnswer == mDNSInterfaceMark || mDNSSameIPv4Address(rr->v4Requester, onesIPv4Addr) || mDNSSameIPv6Address(rr->v6Requester, onesIPv6Addr) ) rr->ImmedUnicast = mDNSfalse; if (rr->ImmedUnicast && rr->ImmedAnswer == InterfaceID) { if ((dest->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address(rr->v4Requester, dest->ip.v4)) || (dest->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address(rr->v6Requester, dest->ip.v6))) { rr->ImmedAnswer = mDNSNULL; // Clear the state fields rr->ImmedUnicast = mDNSfalse; rr->v4Requester = zerov4Addr; rr->v6Requester = zerov6Addr; // Only sent records registered for P2P over P2P interfaces if (intf && !mDNSPlatformValidRecordForInterface(rr, intf->InterfaceID)) { continue; } if (rr->NextResponse == mDNSNULL && nrp != &rr->NextResponse) // rr->NR_AnswerTo { rr->NR_AnswerTo = NR_AnswerMulticast; *nrp = rr; nrp = &rr->NextResponse; } } } } AddAdditionalsToResponseList(m, ResponseRecords, &nrp, InterfaceID); while (ResponseRecords) { mDNSu8 *responseptr = m->omsg.data; mDNSu8 *newptr; InitializeDNSMessage(&m->omsg.h, zeroID, ResponseFlags); // Put answers in the packet while (ResponseRecords && ResponseRecords->NR_AnswerTo) { rr = ResponseRecords; if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) rr->resrec.rrclass |= kDNSClass_UniqueRRSet; // Temporarily set the cache flush bit so PutResourceRecord will set it newptr = PutResourceRecord(&m->omsg, responseptr, &m->omsg.h.numAnswers, &rr->resrec); rr->resrec.rrclass &= ~kDNSClass_UniqueRRSet; // Make sure to clear cache flush bit back to normal state if (!newptr && m->omsg.h.numAnswers) { break; // If packet full, send it now } if (newptr) responseptr = newptr; ResponseRecords = rr->NextResponse; rr->NextResponse = mDNSNULL; rr->NR_AnswerTo = mDNSNULL; rr->NR_AdditionalTo = mDNSNULL; rr->RequireGoodbye = mDNStrue; } // Add additionals, if there's space while (ResponseRecords && !ResponseRecords->NR_AnswerTo) { rr = ResponseRecords; if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) rr->resrec.rrclass |= kDNSClass_UniqueRRSet; // Temporarily set the cache flush bit so PutResourceRecord will set it newptr = PutResourceRecord(&m->omsg, responseptr, &m->omsg.h.numAdditionals, &rr->resrec); rr->resrec.rrclass &= ~kDNSClass_UniqueRRSet; // Make sure to clear cache flush bit back to normal state if (newptr) responseptr = newptr; if (newptr && m->omsg.h.numAnswers) rr->RequireGoodbye = mDNStrue; else if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) rr->ImmedAnswer = mDNSInterfaceMark; ResponseRecords = rr->NextResponse; rr->NextResponse = mDNSNULL; rr->NR_AnswerTo = mDNSNULL; rr->NR_AdditionalTo = mDNSNULL; } if (m->omsg.h.numAnswers) mDNSSendDNSMessage(m, &m->omsg, responseptr, InterfaceID, mDNSNULL, mDNSNULL, dest, MulticastDNSPort, mDNSNULL, mDNSfalse); } } // CompleteDeregistration guarantees that on exit the record will have been cut from the m->ResourceRecords list // and the client's mStatus_MemFree callback will have been invoked mDNSexport void CompleteDeregistration(mDNS *const m, AuthRecord *rr) { LogInfo("CompleteDeregistration: called for Resource record %s", ARDisplayString(m, rr)); // Clearing rr->RequireGoodbye signals mDNS_Deregister_internal() that // it should go ahead and immediately dispose of this registration rr->resrec.RecordType = kDNSRecordTypeShared; rr->RequireGoodbye = mDNSfalse; rr->WakeUp.HMAC = zeroEthAddr; if (rr->AnsweredLocalQ) { AnswerAllLocalQuestionsWithLocalAuthRecord(m, rr, QC_rmv); rr->AnsweredLocalQ = mDNSfalse; } mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); // Don't touch rr after this } // DiscardDeregistrations is used on shutdown and sleep to discard (forcibly and immediately) // any deregistering records that remain in the m->ResourceRecords list. // DiscardDeregistrations calls mDNS_Deregister_internal which can call a user callback, // which may change the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSlocal void DiscardDeregistrations(mDNS *const m) { if (m->CurrentRecord) LogMsg("DiscardDeregistrations ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { AuthRecord *rr = m->CurrentRecord; if (!AuthRecord_uDNS(rr) && rr->resrec.RecordType == kDNSRecordTypeDeregistering) CompleteDeregistration(m, rr); // Don't touch rr after this else m->CurrentRecord = rr->next; } } mDNSlocal mStatus GetLabelDecimalValue(const mDNSu8 *const src, mDNSu8 *dst) { int i, val = 0; if (src[0] < 1 || src[0] > 3) return(mStatus_Invalid); for (i=1; i<=src[0]; i++) { if (src[i] < '0' || src[i] > '9') return(mStatus_Invalid); val = val * 10 + src[i] - '0'; } if (val > 255) return(mStatus_Invalid); *dst = (mDNSu8)val; return(mStatus_NoError); } mDNSlocal mStatus GetIPv4FromName(mDNSAddr *const a, const domainname *const name) { int skip = CountLabels(name) - 6; if (skip < 0) { LogMsg("GetIPFromName: Need six labels in IPv4 reverse mapping name %##s", name); return mStatus_Invalid; } if (GetLabelDecimalValue(SkipLeadingLabels(name, skip+3)->c, &a->ip.v4.b[0]) || GetLabelDecimalValue(SkipLeadingLabels(name, skip+2)->c, &a->ip.v4.b[1]) || GetLabelDecimalValue(SkipLeadingLabels(name, skip+1)->c, &a->ip.v4.b[2]) || GetLabelDecimalValue(SkipLeadingLabels(name, skip+0)->c, &a->ip.v4.b[3])) return mStatus_Invalid; a->type = mDNSAddrType_IPv4; return(mStatus_NoError); } #define HexVal(X) ( ((X) >= '0' && (X) <= '9') ? ((X) - '0' ) : \ ((X) >= 'A' && (X) <= 'F') ? ((X) - 'A' + 10) : \ ((X) >= 'a' && (X) <= 'f') ? ((X) - 'a' + 10) : -1) mDNSlocal mStatus GetIPv6FromName(mDNSAddr *const a, const domainname *const name) { int i, h, l; const domainname *n; int skip = CountLabels(name) - 34; if (skip < 0) { LogMsg("GetIPFromName: Need 34 labels in IPv6 reverse mapping name %##s", name); return mStatus_Invalid; } n = SkipLeadingLabels(name, skip); for (i=0; i<16; i++) { if (n->c[0] != 1) return mStatus_Invalid; l = HexVal(n->c[1]); n = (const domainname *)(n->c + 2); if (n->c[0] != 1) return mStatus_Invalid; h = HexVal(n->c[1]); n = (const domainname *)(n->c + 2); if (l<0 || h<0) return mStatus_Invalid; a->ip.v6.b[15-i] = (mDNSu8)((h << 4) | l); } a->type = mDNSAddrType_IPv6; return(mStatus_NoError); } mDNSlocal mDNSs32 ReverseMapDomainType(const domainname *const name) { int skip = CountLabels(name) - 2; if (skip >= 0) { const domainname *suffix = SkipLeadingLabels(name, skip); if (SameDomainName(suffix, (const domainname*)"\x7" "in-addr" "\x4" "arpa")) return mDNSAddrType_IPv4; if (SameDomainName(suffix, (const domainname*)"\x3" "ip6" "\x4" "arpa")) return mDNSAddrType_IPv6; } return(mDNSAddrType_None); } mDNSlocal void SendARP(mDNS *const m, const mDNSu8 op, const AuthRecord *const rr, const mDNSv4Addr *const spa, const mDNSEthAddr *const tha, const mDNSv4Addr *const tpa, const mDNSEthAddr *const dst) { int i; mDNSu8 *ptr = m->omsg.data; NetworkInterfaceInfo *intf = FirstInterfaceForID(m, rr->resrec.InterfaceID); if (!intf) { LogMsg("SendARP: No interface with InterfaceID %p found %s", rr->resrec.InterfaceID, ARDisplayString(m,rr)); return; } // 0x00 Destination address for (i=0; i<6; i++) *ptr++ = dst->b[i]; // 0x06 Source address (Note: Since we don't currently set the BIOCSHDRCMPLT option, BPF will fill in the real interface address for us) for (i=0; i<6; i++) *ptr++ = intf->MAC.b[0]; // 0x0C ARP Ethertype (0x0806) *ptr++ = 0x08; *ptr++ = 0x06; // 0x0E ARP header *ptr++ = 0x00; *ptr++ = 0x01; // Hardware address space; Ethernet = 1 *ptr++ = 0x08; *ptr++ = 0x00; // Protocol address space; IP = 0x0800 *ptr++ = 6; // Hardware address length *ptr++ = 4; // Protocol address length *ptr++ = 0x00; *ptr++ = op; // opcode; Request = 1, Response = 2 // 0x16 Sender hardware address (our MAC address) for (i=0; i<6; i++) *ptr++ = intf->MAC.b[i]; // 0x1C Sender protocol address for (i=0; i<4; i++) *ptr++ = spa->b[i]; // 0x20 Target hardware address for (i=0; i<6; i++) *ptr++ = tha->b[i]; // 0x26 Target protocol address for (i=0; i<4; i++) *ptr++ = tpa->b[i]; // 0x2A Total ARP Packet length 42 bytes mDNSPlatformSendRawPacket(m->omsg.data, ptr, rr->resrec.InterfaceID); } mDNSlocal mDNSu16 CheckSum(const void *const data, mDNSs32 length, mDNSu32 sum) { const mDNSu16 *ptr = data; while (length > 0) { length -= 2; sum += *ptr++; } sum = (sum & 0xFFFF) + (sum >> 16); sum = (sum & 0xFFFF) + (sum >> 16); return(sum != 0xFFFF ? sum : 0); } mDNSlocal mDNSu16 IPv6CheckSum(const mDNSv6Addr *const src, const mDNSv6Addr *const dst, const mDNSu8 protocol, const void *const data, const mDNSu32 length) { IPv6PseudoHeader ph; ph.src = *src; ph.dst = *dst; ph.len.b[0] = length >> 24; ph.len.b[1] = length >> 16; ph.len.b[2] = length >> 8; ph.len.b[3] = length; ph.pro.b[0] = 0; ph.pro.b[1] = 0; ph.pro.b[2] = 0; ph.pro.b[3] = protocol; return CheckSum(&ph, sizeof(ph), CheckSum(data, length, 0)); } mDNSlocal void SendNDP(mDNS *const m, const mDNSu8 op, const mDNSu8 flags, const AuthRecord *const rr, const mDNSv6Addr *const spa, const mDNSEthAddr *const tha, const mDNSv6Addr *const tpa, const mDNSEthAddr *const dst) { int i; mDNSOpaque16 checksum; mDNSu8 *ptr = m->omsg.data; // Some recipient hosts seem to ignore Neighbor Solicitations if the IPv6-layer destination address is not the // appropriate IPv6 solicited node multicast address, so we use that IPv6-layer destination address, even though // at the Ethernet-layer we unicast the packet to the intended target, to avoid wasting network bandwidth. const mDNSv6Addr mc = { { 0xFF,0x02,0x00,0x00, 0,0,0,0, 0,0,0,1, 0xFF,tpa->b[0xD],tpa->b[0xE],tpa->b[0xF] } }; const mDNSv6Addr *const v6dst = (op == NDP_Sol) ? &mc : tpa; NetworkInterfaceInfo *intf = FirstInterfaceForID(m, rr->resrec.InterfaceID); if (!intf) { LogMsg("SendNDP: No interface with InterfaceID %p found %s", rr->resrec.InterfaceID, ARDisplayString(m,rr)); return; } // 0x00 Destination address for (i=0; i<6; i++) *ptr++ = dst->b[i]; // Right now we only send Neighbor Solicitations to verify whether the host we're proxying for has gone to sleep yet. // Since we know who we're looking for, we send it via Ethernet-layer unicast, rather than bothering every host on the // link with a pointless link-layer multicast. // Should we want to send traditional Neighbor Solicitations in the future, where we really don't know in advance what // Ethernet-layer address we're looking for, we'll need to send to the appropriate Ethernet-layer multicast address: // *ptr++ = 0x33; // *ptr++ = 0x33; // *ptr++ = 0xFF; // *ptr++ = tpa->b[0xD]; // *ptr++ = tpa->b[0xE]; // *ptr++ = tpa->b[0xF]; // 0x06 Source address (Note: Since we don't currently set the BIOCSHDRCMPLT option, BPF will fill in the real interface address for us) for (i=0; i<6; i++) if (tha) *ptr++ = tha->b[i]; else *ptr++ = intf->MAC.b[i]; // 0x0C IPv6 Ethertype (0x86DD) *ptr++ = 0x86; *ptr++ = 0xDD; // 0x0E IPv6 header *ptr++ = 0x60; *ptr++ = 0x00; *ptr++ = 0x00; *ptr++ = 0x00; // Version, Traffic Class, Flow Label *ptr++ = 0x00; *ptr++ = 0x20; // Length *ptr++ = 0x3A; // Protocol == ICMPv6 *ptr++ = 0xFF; // Hop Limit // 0x16 Sender IPv6 address for (i=0; i<16; i++) *ptr++ = spa->b[i]; // 0x26 Destination IPv6 address for (i=0; i<16; i++) *ptr++ = v6dst->b[i]; // 0x36 NDP header *ptr++ = op; // 0x87 == Neighbor Solicitation, 0x88 == Neighbor Advertisement *ptr++ = 0x00; // Code *ptr++ = 0x00; *ptr++ = 0x00; // Checksum placeholder (0x38, 0x39) *ptr++ = flags; *ptr++ = 0x00; *ptr++ = 0x00; *ptr++ = 0x00; if (op == NDP_Sol) // Neighbor Solicitation. The NDP "target" is the address we seek. { // 0x3E NDP target. for (i=0; i<16; i++) *ptr++ = tpa->b[i]; // 0x4E Source Link-layer Address // // MUST NOT be included when the source IP address is the unspecified address. // Otherwise, on link layers that have addresses this option MUST be included // in multicast solicitations and SHOULD be included in unicast solicitations. if (!mDNSIPv6AddressIsZero(*spa)) { *ptr++ = NDP_SrcLL; // Option Type 1 == Source Link-layer Address *ptr++ = 0x01; // Option length 1 (in units of 8 octets) for (i=0; i<6; i++) if (tha) *ptr++ = tha->b[i]; else *ptr++ = intf->MAC.b[i]; } } else // Neighbor Advertisement. The NDP "target" is the address we're giving information about. { // 0x3E NDP target. for (i=0; i<16; i++) *ptr++ = spa->b[i]; // 0x4E Target Link-layer Address *ptr++ = NDP_TgtLL; // Option Type 2 == Target Link-layer Address *ptr++ = 0x01; // Option length 1 (in units of 8 octets) for (i=0; i<6; i++) if (tha) *ptr++ = tha->b[i]; else *ptr++ = intf->MAC.b[i]; } // 0x4E or 0x56 Total NDP Packet length 78 or 86 bytes m->omsg.data[0x13] = ptr - &m->omsg.data[0x36]; // Compute actual length checksum.NotAnInteger = ~IPv6CheckSum(spa, v6dst, 0x3A, &m->omsg.data[0x36], m->omsg.data[0x13]); m->omsg.data[0x38] = checksum.b[0]; m->omsg.data[0x39] = checksum.b[1]; mDNSPlatformSendRawPacket(m->omsg.data, ptr, rr->resrec.InterfaceID); } mDNSlocal void SetupTracerOpt(const mDNS *const m, rdataOPT *const Trace) { mDNSu32 DNS_VERS = _DNS_SD_H; Trace->u.tracer.platf = m->mDNS_plat; Trace->u.tracer.mDNSv = DNS_VERS; Trace->opt = kDNSOpt_Trace; Trace->optlen = DNSOpt_TraceData_Space - 4; } mDNSlocal void SetupOwnerOpt(const mDNS *const m, const NetworkInterfaceInfo *const intf, rdataOPT *const owner) { owner->u.owner.vers = 0; owner->u.owner.seq = m->SleepSeqNum; owner->u.owner.HMAC = m->PrimaryMAC; owner->u.owner.IMAC = intf->MAC; owner->u.owner.password = zeroEthAddr; // Don't try to compute the optlen until *after* we've set up the data fields // Right now the DNSOpt_Owner_Space macro does not depend on the owner->u.owner being set up correctly, but in the future it might owner->opt = kDNSOpt_Owner; owner->optlen = DNSOpt_Owner_Space(&m->PrimaryMAC, &intf->MAC) - 4; } mDNSlocal void GrantUpdateCredit(AuthRecord *rr) { if (++rr->UpdateCredits >= kMaxUpdateCredits) rr->NextUpdateCredit = 0; else rr->NextUpdateCredit = NonZeroTime(rr->NextUpdateCredit + kUpdateCreditRefreshInterval); } mDNSlocal mDNSBool ShouldSendGoodbyesBeforeSleep(mDNS *const m, const NetworkInterfaceInfo *intf, AuthRecord *rr) { // If there are no sleep proxies, we set the state to SleepState_Sleeping explicitly // and hence there is no need to check for Transfering state. But if we have sleep // proxies and partially sending goodbyes for some records, we will be in Transfering // state and hence need to make sure that we send goodbyes in that case too. Checking whether // we are not awake handles both cases. if ((rr->AuthFlags & AuthFlagsWakeOnly) && (m->SleepState != SleepState_Awake)) { debugf("ShouldSendGoodbyesBeforeSleep: marking for goodbye", ARDisplayString(m, rr)); return mDNStrue; } if (m->SleepState != SleepState_Sleeping) return mDNSfalse; // If we are going to sleep and in SleepState_Sleeping, SendGoodbyes on the interface tell you // whether you can send goodbyes or not. if (!intf->SendGoodbyes) { debugf("ShouldSendGoodbyesBeforeSleep: not sending goodbye %s, int %p", ARDisplayString(m, rr), intf->InterfaceID); return mDNSfalse; } else { debugf("ShouldSendGoodbyesBeforeSleep: sending goodbye %s, int %p", ARDisplayString(m, rr), intf->InterfaceID); return mDNStrue; } } // Note about acceleration of announcements to facilitate automatic coalescing of // multiple independent threads of announcements into a single synchronized thread: // The announcements in the packet may be at different stages of maturity; // One-second interval, two-second interval, four-second interval, and so on. // After we've put in all the announcements that are due, we then consider // whether there are other nearly-due announcements that are worth accelerating. // To be eligible for acceleration, a record MUST NOT be older (further along // its timeline) than the most mature record we've already put in the packet. // In other words, younger records can have their timelines accelerated to catch up // with their elder bretheren; this narrows the age gap and helps them eventually get in sync. // Older records cannot have their timelines accelerated; this would just widen // the gap between them and their younger bretheren and get them even more out of sync. // Note: SendResponses calls mDNS_Deregister_internal which can call a user callback, which may change // the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSlocal void SendResponses(mDNS *const m) { int pktcount = 0; AuthRecord *rr, *r2; mDNSs32 maxExistingAnnounceInterval = 0; const NetworkInterfaceInfo *intf = GetFirstActiveInterface(m->HostInterfaces); m->NextScheduledResponse = m->timenow + FutureTime; if (m->SleepState == SleepState_Transferring) RetrySPSRegistrations(m); for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->ImmedUnicast) { mDNSAddr v4 = { mDNSAddrType_IPv4, {{{0}}} }; mDNSAddr v6 = { mDNSAddrType_IPv6, {{{0}}} }; v4.ip.v4 = rr->v4Requester; v6.ip.v6 = rr->v6Requester; if (!mDNSIPv4AddressIsZero(rr->v4Requester)) SendDelayedUnicastResponse(m, &v4, rr->ImmedAnswer); if (!mDNSIPv6AddressIsZero(rr->v6Requester)) SendDelayedUnicastResponse(m, &v6, rr->ImmedAnswer); if (rr->ImmedUnicast) { LogMsg("SendResponses: ERROR: rr->ImmedUnicast still set: %s", ARDisplayString(m, rr)); rr->ImmedUnicast = mDNSfalse; } } // *** // *** 1. Setup: Set the SendRNow and ImmedAnswer fields to indicate which interface(s) the records need to be sent on // *** // Run through our list of records, and decide which ones we're going to announce on all interfaces for (rr = m->ResourceRecords; rr; rr=rr->next) { while (rr->NextUpdateCredit && m->timenow - rr->NextUpdateCredit >= 0) GrantUpdateCredit(rr); if (TimeToAnnounceThisRecord(rr, m->timenow)) { if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) { if (!rr->WakeUp.HMAC.l[0]) { if (rr->AnnounceCount) rr->ImmedAnswer = mDNSInterfaceMark; // Send goodbye packet on all interfaces } else { mDNSBool unicastOnly; LogSPS("SendResponses: Sending wakeup %2d for %.6a %s", rr->AnnounceCount-3, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); unicastOnly = ((rr->AnnounceCount == WakeupCount) || (rr->AnnounceCount == WakeupCount - 1)) ? mDNStrue : mDNSfalse; SendWakeup(m, rr->resrec.InterfaceID, &rr->WakeUp.IMAC, &rr->WakeUp.password, unicastOnly); for (r2 = rr; r2; r2=r2->next) if ((r2->resrec.RecordType == kDNSRecordTypeDeregistering) && r2->AnnounceCount && (r2->resrec.InterfaceID == rr->resrec.InterfaceID) && mDNSSameEthAddress(&r2->WakeUp.IMAC, &rr->WakeUp.IMAC) && !mDNSSameEthAddress(&zeroEthAddr, &r2->WakeUp.HMAC)) { // For now we only want to send a single Unsolicited Neighbor Advertisement restoring the address to the original // owner, because these packets can cause some IPv6 stacks to falsely conclude that there's an address conflict. if (r2->AddressProxy.type == mDNSAddrType_IPv6 && r2->AnnounceCount == WakeupCount) { LogSPS("NDP Announcement %2d Releasing traffic for H-MAC %.6a I-MAC %.6a %s", r2->AnnounceCount-3, &r2->WakeUp.HMAC, &r2->WakeUp.IMAC, ARDisplayString(m,r2)); SendNDP(m, NDP_Adv, NDP_Override, r2, &r2->AddressProxy.ip.v6, &r2->WakeUp.IMAC, &AllHosts_v6, &AllHosts_v6_Eth); } r2->LastAPTime = m->timenow; // After 15 wakeups without success (maybe host has left the network) send three goodbyes instead if (--r2->AnnounceCount <= GoodbyeCount) r2->WakeUp.HMAC = zeroEthAddr; } } } else if (ResourceRecordIsValidAnswer(rr)) { if (rr->AddressProxy.type) { if (!mDNSSameEthAddress(&zeroEthAddr, &rr->WakeUp.HMAC)) { rr->AnnounceCount--; rr->ThisAPInterval *= 2; rr->LastAPTime = m->timenow; if (rr->AddressProxy.type == mDNSAddrType_IPv4) { LogSPS("ARP Announcement %2d Capturing traffic for H-MAC %.6a I-MAC %.6a %s", rr->AnnounceCount, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m,rr)); SendARP(m, 1, rr, &rr->AddressProxy.ip.v4, &zeroEthAddr, &rr->AddressProxy.ip.v4, &onesEthAddr); } else if (rr->AddressProxy.type == mDNSAddrType_IPv6) { LogSPS("NDP Announcement %2d Capturing traffic for H-MAC %.6a I-MAC %.6a %s", rr->AnnounceCount, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m,rr)); SendNDP(m, NDP_Adv, NDP_Override, rr, &rr->AddressProxy.ip.v6, mDNSNULL, &AllHosts_v6, &AllHosts_v6_Eth); } } } else { rr->ImmedAnswer = mDNSInterfaceMark; // Send on all interfaces if (maxExistingAnnounceInterval < rr->ThisAPInterval) maxExistingAnnounceInterval = rr->ThisAPInterval; if (rr->UpdateBlocked) rr->UpdateBlocked = 0; } } } } // Any interface-specific records we're going to send are marked as being sent on all appropriate interfaces (which is just one) // Eligible records that are more than half-way to their announcement time are accelerated for (rr = m->ResourceRecords; rr; rr=rr->next) if ((rr->resrec.InterfaceID && rr->ImmedAnswer) || (rr->ThisAPInterval <= maxExistingAnnounceInterval && TimeToAnnounceThisRecord(rr, m->timenow + rr->ThisAPInterval/2) && !rr->AddressProxy.type && // Don't include ARP Annoucements when considering which records to accelerate ResourceRecordIsValidAnswer(rr))) rr->ImmedAnswer = mDNSInterfaceMark; // Send on all interfaces // When sending SRV records (particularly when announcing a new service) automatically add related Address record(s) as additionals // Note: Currently all address records are interface-specific, so it's safe to set ImmedAdditional to their InterfaceID, // which will be non-null. If by some chance there is an address record that's not interface-specific (should never happen) // then all that means is that it won't get sent -- which would not be the end of the world. for (rr = m->ResourceRecords; rr; rr=rr->next) { if (rr->ImmedAnswer && rr->resrec.rrtype == kDNSType_SRV) for (r2=m->ResourceRecords; r2; r2=r2->next) // Scan list of resource records if (RRTypeIsAddressType(r2->resrec.rrtype) && // For all address records (A/AAAA) ... ResourceRecordIsValidAnswer(r2) && // ... which are valid for answer ... rr->LastMCTime - r2->LastMCTime >= 0 && // ... which we have not sent recently ... rr->resrec.rdatahash == r2->resrec.namehash && // ... whose name is the name of the SRV target SameDomainName(&rr->resrec.rdata->u.srv.target, r2->resrec.name) && (rr->ImmedAnswer == mDNSInterfaceMark || rr->ImmedAnswer == r2->resrec.InterfaceID)) r2->ImmedAdditional = r2->resrec.InterfaceID; // ... then mark this address record for sending too // We also make sure we send the DeviceInfo TXT record too, if necessary // We check for RecordType == kDNSRecordTypeShared because we don't want to tag the // DeviceInfo TXT record onto a goodbye packet (RecordType == kDNSRecordTypeDeregistering). if (rr->ImmedAnswer && rr->resrec.RecordType == kDNSRecordTypeShared && rr->resrec.rrtype == kDNSType_PTR) if (ResourceRecordIsValidAnswer(&m->DeviceInfo) && SameDomainLabel(rr->resrec.rdata->u.name.c, m->DeviceInfo.resrec.name->c)) { if (!m->DeviceInfo.ImmedAnswer) m->DeviceInfo.ImmedAnswer = rr->ImmedAnswer; else m->DeviceInfo.ImmedAnswer = mDNSInterfaceMark; } } // If there's a record which is supposed to be unique that we're going to send, then make sure that we give // the whole RRSet as an atomic unit. That means that if we have any other records with the same name/type/class // then we need to mark them for sending too. Otherwise, if we set the kDNSClass_UniqueRRSet bit on a // record, then other RRSet members that have not been sent recently will get flushed out of client caches. // -- If a record is marked to be sent on a certain interface, make sure the whole set is marked to be sent on that interface // -- If any record is marked to be sent on all interfaces, make sure the whole set is marked to be sent on all interfaces for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) { if (rr->ImmedAnswer) // If we're sending this as answer, see that its whole RRSet is similarly marked { for (r2 = m->ResourceRecords; r2; r2=r2->next) { if ((r2->resrec.RecordType & kDNSRecordTypeUniqueMask) && ResourceRecordIsValidAnswer(r2) && (r2->ImmedAnswer != mDNSInterfaceMark) && (r2->ImmedAnswer != rr->ImmedAnswer) && SameResourceRecordSignature(r2, rr) && ((rr->ImmedAnswer == mDNSInterfaceMark) || IsInterfaceValidForAuthRecord(r2, rr->ImmedAnswer))) { r2->ImmedAnswer = !r2->ImmedAnswer ? rr->ImmedAnswer : mDNSInterfaceMark; } } } else if (rr->ImmedAdditional) // If we're sending this as additional, see that its whole RRSet is similarly marked { for (r2 = m->ResourceRecords; r2; r2=r2->next) { if ((r2->resrec.RecordType & kDNSRecordTypeUniqueMask) && ResourceRecordIsValidAnswer(r2) && (r2->ImmedAdditional != rr->ImmedAdditional) && SameResourceRecordSignature(r2, rr) && IsInterfaceValidForAuthRecord(r2, rr->ImmedAdditional)) { r2->ImmedAdditional = rr->ImmedAdditional; } } } } // Now set SendRNow state appropriately for (rr = m->ResourceRecords; rr; rr=rr->next) { if (rr->ImmedAnswer == mDNSInterfaceMark) // Sending this record on all appropriate interfaces { rr->SendRNow = !intf ? mDNSNULL : (rr->resrec.InterfaceID) ? rr->resrec.InterfaceID : intf->InterfaceID; rr->ImmedAdditional = mDNSNULL; // No need to send as additional if sending as answer rr->LastMCTime = m->timenow; rr->LastMCInterface = rr->ImmedAnswer; rr->ProbeRestartCount = 0; // Reset the probe restart count // If we're announcing this record, and it's at least half-way to its ordained time, then consider this announcement done if (TimeToAnnounceThisRecord(rr, m->timenow + rr->ThisAPInterval/2)) { rr->AnnounceCount--; if (rr->resrec.RecordType != kDNSRecordTypeDeregistering) rr->ThisAPInterval *= 2; rr->LastAPTime = m->timenow; debugf("Announcing %##s (%s) %d", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), rr->AnnounceCount); } } else if (rr->ImmedAnswer) // Else, just respond to a single query on single interface: { rr->SendRNow = rr->ImmedAnswer; // Just respond on that interface rr->ImmedAdditional = mDNSNULL; // No need to send as additional too rr->LastMCTime = m->timenow; rr->LastMCInterface = rr->ImmedAnswer; } SetNextAnnounceProbeTime(m, rr); //if (rr->SendRNow) LogMsg("%-15.4a %s", &rr->v4Requester, ARDisplayString(m, rr)); } // *** // *** 2. Loop through interface list, sending records as appropriate // *** while (intf) { int OwnerRecordSpace = (m->AnnounceOwner && intf->MAC.l[0]) ? DNSOpt_Header_Space + DNSOpt_Owner_Space(&m->PrimaryMAC, &intf->MAC) : 0; int TraceRecordSpace = (mDNS_McastTracingEnabled && MDNS_TRACER) ? DNSOpt_Header_Space + DNSOpt_TraceData_Space : 0; int numDereg = 0; int numAnnounce = 0; int numAnswer = 0; mDNSu8 *responseptr = m->omsg.data; mDNSu8 *newptr; InitializeDNSMessage(&m->omsg.h, zeroID, ResponseFlags); // First Pass. Look for: // 1. Deregistering records that need to send their goodbye packet // 2. Updated records that need to retract their old data // 3. Answers and announcements we need to send for (rr = m->ResourceRecords; rr; rr=rr->next) { // Skip this interface if the record InterfaceID is *Any and the record is not // appropriate for the interface type. if ((rr->SendRNow == intf->InterfaceID) && ((rr->resrec.InterfaceID == mDNSInterface_Any) && !mDNSPlatformValidRecordForInterface(rr, intf->InterfaceID))) { rr->SendRNow = GetNextActiveInterfaceID(intf); } else if (rr->SendRNow == intf->InterfaceID) { RData *OldRData = rr->resrec.rdata; mDNSu16 oldrdlength = rr->resrec.rdlength; mDNSu8 active = (mDNSu8) (rr->resrec.RecordType != kDNSRecordTypeDeregistering && !ShouldSendGoodbyesBeforeSleep(m, intf, rr)); newptr = mDNSNULL; if (rr->NewRData && active) { // See if we should send a courtesy "goodbye" for the old data before we replace it. if (ResourceRecordIsValidAnswer(rr) && rr->resrec.RecordType == kDNSRecordTypeShared && rr->RequireGoodbye) { newptr = PutRR_OS_TTL(responseptr, &m->omsg.h.numAnswers, &rr->resrec, 0); if (newptr) { responseptr = newptr; numDereg++; rr->RequireGoodbye = mDNSfalse; } else continue; // If this packet is already too full to hold the goodbye for this record, skip it for now and we'll retry later } SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength); } if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) rr->resrec.rrclass |= kDNSClass_UniqueRRSet; // Temporarily set the cache flush bit so PutResourceRecord will set it newptr = PutRR_OS_TTL(responseptr, &m->omsg.h.numAnswers, &rr->resrec, active ? rr->resrec.rroriginalttl : 0); rr->resrec.rrclass &= ~kDNSClass_UniqueRRSet; // Make sure to clear cache flush bit back to normal state if (newptr) { responseptr = newptr; rr->RequireGoodbye = active; if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) numDereg++; else if (rr->LastAPTime == m->timenow) numAnnounce++;else numAnswer++; } if (rr->NewRData && active) SetNewRData(&rr->resrec, OldRData, oldrdlength); // The first time through (pktcount==0), if this record is verified unique // (i.e. typically A, AAAA, SRV, TXT and reverse-mapping PTR), set the flag to add an NSEC too. if (!pktcount && active && (rr->resrec.RecordType & kDNSRecordTypeActiveUniqueMask) && !rr->SendNSECNow) rr->SendNSECNow = mDNSInterfaceMark; if (newptr) // If succeeded in sending, advance to next interface { // If sending on all interfaces, go to next interface; else we're finished now if (rr->ImmedAnswer == mDNSInterfaceMark && rr->resrec.InterfaceID == mDNSInterface_Any) rr->SendRNow = GetNextActiveInterfaceID(intf); else rr->SendRNow = mDNSNULL; } } } // Second Pass. Add additional records, if there's space. newptr = responseptr; for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->ImmedAdditional == intf->InterfaceID) if (ResourceRecordIsValidAnswer(rr)) { // If we have at least one answer already in the packet, then plan to add additionals too mDNSBool SendAdditional = (m->omsg.h.numAnswers > 0); // If we're not planning to send any additionals, but this record is a unique one, then // make sure we haven't already sent any other members of its RRSet -- if we have, then they // will have had the cache flush bit set, so now we need to finish the job and send the rest. if (!SendAdditional && (rr->resrec.RecordType & kDNSRecordTypeUniqueMask)) { const AuthRecord *a; for (a = m->ResourceRecords; a; a=a->next) if (a->LastMCTime == m->timenow && a->LastMCInterface == intf->InterfaceID && SameResourceRecordSignature(a, rr)) { SendAdditional = mDNStrue; break; } } if (!SendAdditional) // If we don't want to send this after all, rr->ImmedAdditional = mDNSNULL; // then cancel its ImmedAdditional field else if (newptr) // Else, try to add it if we can { // The first time through (pktcount==0), if this record is verified unique // (i.e. typically A, AAAA, SRV, TXT and reverse-mapping PTR), set the flag to add an NSEC too. if (!pktcount && (rr->resrec.RecordType & kDNSRecordTypeActiveUniqueMask) && !rr->SendNSECNow) rr->SendNSECNow = mDNSInterfaceMark; if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) rr->resrec.rrclass |= kDNSClass_UniqueRRSet; // Temporarily set the cache flush bit so PutResourceRecord will set it newptr = PutRR_OS(newptr, &m->omsg.h.numAdditionals, &rr->resrec); rr->resrec.rrclass &= ~kDNSClass_UniqueRRSet; // Make sure to clear cache flush bit back to normal state if (newptr) { responseptr = newptr; rr->ImmedAdditional = mDNSNULL; rr->RequireGoodbye = mDNStrue; // If we successfully put this additional record in the packet, we record LastMCTime & LastMCInterface. // This matters particularly in the case where we have more than one IPv6 (or IPv4) address, because otherwise, // when we see our own multicast with the cache flush bit set, if we haven't set LastMCTime, then we'll get // all concerned and re-announce our record again to make sure it doesn't get flushed from peer caches. rr->LastMCTime = m->timenow; rr->LastMCInterface = intf->InterfaceID; } } } // Third Pass. Add NSEC records, if there's space. // When we're generating an NSEC record in response to a specify query for that type // (recognized by rr->SendNSECNow == intf->InterfaceID) we should really put the NSEC in the Answer Section, // not Additional Section, but for now it's easier to handle both cases in this Additional Section loop here. for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->SendNSECNow == mDNSInterfaceMark || rr->SendNSECNow == intf->InterfaceID) { AuthRecord nsec; mDNSu8 *ptr; int len; mDNS_SetupResourceRecord(&nsec, mDNSNULL, mDNSInterface_Any, kDNSType_NSEC, rr->resrec.rroriginalttl, kDNSRecordTypeUnique, AuthRecordAny, mDNSNULL, mDNSNULL); nsec.resrec.rrclass |= kDNSClass_UniqueRRSet; AssignDomainName(&nsec.namestorage, rr->resrec.name); ptr = nsec.rdatastorage.u.data; len = DomainNameLength(rr->resrec.name); // We have a nxt name followed by window number, window length and a window bitmap nsec.resrec.rdlength = len + 2 + NSEC_MCAST_WINDOW_SIZE; if (nsec.resrec.rdlength <= StandardAuthRDSize) { mDNSPlatformMemZero(ptr, nsec.resrec.rdlength); AssignDomainName((domainname *)ptr, rr->resrec.name); ptr += len; *ptr++ = 0; // window number *ptr++ = NSEC_MCAST_WINDOW_SIZE; // window length for (r2 = m->ResourceRecords; r2; r2=r2->next) if (ResourceRecordIsValidAnswer(r2) && SameResourceRecordNameClassInterface(r2, rr)) { if (r2->resrec.rrtype >= kDNSQType_ANY) { LogMsg("SendResponses: Can't create NSEC for record %s", ARDisplayString(m, r2)); break; } else ptr[r2->resrec.rrtype >> 3] |= 128 >> (r2->resrec.rrtype & 7); } newptr = responseptr; if (!r2) // If we successfully built our NSEC record, add it to the packet now { newptr = PutRR_OS(responseptr, &m->omsg.h.numAdditionals, &nsec.resrec); if (newptr) responseptr = newptr; } } else LogMsg("SendResponses: not enough space (%d) in authrecord for nsec", nsec.resrec.rdlength); // If we successfully put the NSEC record, clear the SendNSECNow flag // If we consider this NSEC optional, then we unconditionally clear the SendNSECNow flag, even if we fail to put this additional record if (newptr || rr->SendNSECNow == mDNSInterfaceMark) { rr->SendNSECNow = mDNSNULL; // Run through remainder of list clearing SendNSECNow flag for all other records which would generate the same NSEC for (r2 = rr->next; r2; r2=r2->next) if (SameResourceRecordNameClassInterface(r2, rr)) if (r2->SendNSECNow == mDNSInterfaceMark || r2->SendNSECNow == intf->InterfaceID) r2->SendNSECNow = mDNSNULL; } } if (m->omsg.h.numAnswers || m->omsg.h.numAdditionals) { // If we have data to send, add OWNER/TRACER/OWNER+TRACER option if necessary, then send packet if (OwnerRecordSpace || TraceRecordSpace) { AuthRecord opt; mDNS_SetupResourceRecord(&opt, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); opt.resrec.rrclass = NormalMaxDNSMessageData; opt.resrec.rdlength = sizeof(rdataOPT); opt.resrec.rdestimate = sizeof(rdataOPT); if (OwnerRecordSpace && TraceRecordSpace) { opt.resrec.rdlength += sizeof(rdataOPT); // Two options in this OPT record opt.resrec.rdestimate += sizeof(rdataOPT); SetupOwnerOpt(m, intf, &opt.resrec.rdata->u.opt[0]); SetupTracerOpt(m, &opt.resrec.rdata->u.opt[1]); } else if (OwnerRecordSpace) { SetupOwnerOpt(m, intf, &opt.resrec.rdata->u.opt[0]); } else if (TraceRecordSpace) { SetupTracerOpt(m, &opt.resrec.rdata->u.opt[0]); } newptr = PutResourceRecord(&m->omsg, responseptr, &m->omsg.h.numAdditionals, &opt.resrec); if (newptr) { responseptr = newptr; } else if (m->omsg.h.numAnswers + m->omsg.h.numAuthorities + m->omsg.h.numAdditionals == 1) { LogInfo("SendResponses: No space in packet for %s %s OPT record (%d/%d/%d/%d) %s", OwnerRecordSpace ? "OWNER" : "", TraceRecordSpace ? "TRACER" : "", m->omsg.h.numQuestions, m->omsg.h.numAnswers, m->omsg.h.numAuthorities, m->omsg.h.numAdditionals, ARDisplayString(m, &opt)); } else { LogMsg("SendResponses: How did we fail to have space for %s %s OPT record (%d/%d/%d/%d) %s", OwnerRecordSpace ? "OWNER" : "", TraceRecordSpace ? "TRACER" : "", m->omsg.h.numQuestions, m->omsg.h.numAnswers, m->omsg.h.numAuthorities, m->omsg.h.numAdditionals, ARDisplayString(m, &opt)); } } debugf("SendResponses: Sending %d Deregistration%s, %d Announcement%s, %d Answer%s, %d Additional%s on %p", numDereg, numDereg == 1 ? "" : "s", numAnnounce, numAnnounce == 1 ? "" : "s", numAnswer, numAnswer == 1 ? "" : "s", m->omsg.h.numAdditionals, m->omsg.h.numAdditionals == 1 ? "" : "s", intf->InterfaceID); if (intf->IPv4Available) mDNSSendDNSMessage(m, &m->omsg, responseptr, intf->InterfaceID, mDNSNULL, mDNSNULL, &AllDNSLinkGroup_v4, MulticastDNSPort, mDNSNULL, mDNSfalse); if (intf->IPv6Available) mDNSSendDNSMessage(m, &m->omsg, responseptr, intf->InterfaceID, mDNSNULL, mDNSNULL, &AllDNSLinkGroup_v6, MulticastDNSPort, mDNSNULL, mDNSfalse); if (!m->SuppressSending) m->SuppressSending = NonZeroTime(m->timenow + (mDNSPlatformOneSecond+9)/10); if (++pktcount >= 1000) { LogMsg("SendResponses exceeded loop limit %d: giving up", pktcount); break; } // There might be more things to send on this interface, so go around one more time and try again. } else // Nothing more to send on this interface; go to next { const NetworkInterfaceInfo *next = GetFirstActiveInterface(intf->next); #if MDNS_DEBUGMSGS && 0 const char *const msg = next ? "SendResponses: Nothing more on %p; moving to %p" : "SendResponses: Nothing more on %p"; debugf(msg, intf, next); #endif intf = next; pktcount = 0; // When we move to a new interface, reset packet count back to zero -- NSEC generation logic uses it } } // *** // *** 3. Cleanup: Now that everything is sent, call client callback functions, and reset state variables // *** if (m->CurrentRecord) LogMsg("SendResponses ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { rr = m->CurrentRecord; m->CurrentRecord = rr->next; if (rr->SendRNow) { if (rr->ARType != AuthRecordLocalOnly && rr->ARType != AuthRecordP2P) LogInfo("SendResponses: No active interface %d to send: %d %02X %s", IIDPrintable(rr->SendRNow), IIDPrintable(rr->resrec.InterfaceID), rr->resrec.RecordType, ARDisplayString(m, rr)); rr->SendRNow = mDNSNULL; } if (rr->ImmedAnswer || rr->resrec.RecordType == kDNSRecordTypeDeregistering) { if (rr->NewRData) CompleteRDataUpdate(m, rr); // Update our rdata, clear the NewRData pointer, and return memory to the client if (rr->resrec.RecordType == kDNSRecordTypeDeregistering && rr->AnnounceCount == 0) { // For Unicast, when we get the response from the server, we will call CompleteDeregistration if (!AuthRecord_uDNS(rr)) CompleteDeregistration(m, rr); // Don't touch rr after this } else { rr->ImmedAnswer = mDNSNULL; rr->ImmedUnicast = mDNSfalse; rr->v4Requester = zerov4Addr; rr->v6Requester = zerov6Addr; } } } verbosedebugf("SendResponses: Next in %ld ticks", m->NextScheduledResponse - m->timenow); } // Calling CheckCacheExpiration() is an expensive operation because it has to look at the entire cache, // so we want to be lazy about how frequently we do it. // 1. If a cache record is currently referenced by *no* active questions, // then we don't mind expiring it up to a minute late (who will know?) // 2. Else, if a cache record is due for some of its final expiration queries, // we'll allow them to be late by up to 2% of the TTL // 3. Else, if a cache record has completed all its final expiration queries without success, // and is expiring, and had an original TTL more than ten seconds, we'll allow it to be one second late // 4. Else, it is expiring and had an original TTL of ten seconds or less (includes explicit goodbye packets), // so allow at most 1/10 second lateness // 5. For records with rroriginalttl set to zero, that means we really want to delete them immediately // (we have a new record with DelayDelivery set, waiting for the old record to go away before we can notify clients). #define CacheCheckGracePeriod(CR) ( \ ((CR)->CRActiveQuestion == mDNSNULL ) ? (60 * mDNSPlatformOneSecond) : \ ((CR)->UnansweredQueries < MaxUnansweredQueries) ? (TicksTTL(CR)/50) : \ ((CR)->resrec.rroriginalttl > 10 ) ? (mDNSPlatformOneSecond) : \ ((CR)->resrec.rroriginalttl > 0 ) ? (mDNSPlatformOneSecond/10) : 0) #define NextCacheCheckEvent(CR) ((CR)->NextRequiredQuery + CacheCheckGracePeriod(CR)) mDNSexport void ScheduleNextCacheCheckTime(mDNS *const m, const mDNSu32 slot, const mDNSs32 event) { if (m->rrcache_nextcheck[slot] - event > 0) m->rrcache_nextcheck[slot] = event; if (m->NextCacheCheck - event > 0) m->NextCacheCheck = event; } // Note: MUST call SetNextCacheCheckTimeForRecord any time we change: // rr->TimeRcvd // rr->resrec.rroriginalttl // rr->UnansweredQueries // rr->CRActiveQuestion mDNSexport void SetNextCacheCheckTimeForRecord(mDNS *const m, CacheRecord *const rr) { rr->NextRequiredQuery = RRExpireTime(rr); // If we have an active question, then see if we want to schedule a refresher query for this record. // Usually we expect to do four queries, at 80-82%, 85-87%, 90-92% and then 95-97% of the TTL. if (rr->CRActiveQuestion && rr->UnansweredQueries < MaxUnansweredQueries) { rr->NextRequiredQuery -= TicksTTL(rr)/20 * (MaxUnansweredQueries - rr->UnansweredQueries); rr->NextRequiredQuery += mDNSRandom((mDNSu32)TicksTTL(rr)/50); verbosedebugf("SetNextCacheCheckTimeForRecord: NextRequiredQuery in %ld sec CacheCheckGracePeriod %d ticks for %s", (rr->NextRequiredQuery - m->timenow) / mDNSPlatformOneSecond, CacheCheckGracePeriod(rr), CRDisplayString(m,rr)); } ScheduleNextCacheCheckTime(m, HashSlotFromNameHash(rr->resrec.namehash), NextCacheCheckEvent(rr)); } #define kMinimumReconfirmTime ((mDNSu32)mDNSPlatformOneSecond * 5) #define kDefaultReconfirmTimeForWake ((mDNSu32)mDNSPlatformOneSecond * 5) #define kDefaultReconfirmTimeForNoAnswer ((mDNSu32)mDNSPlatformOneSecond * 5) // Delay before restarting questions on a flapping interface. #define kDefaultQueryDelayTimeForFlappingInterface ((mDNSu32)mDNSPlatformOneSecond * 3) // After kDefaultQueryDelayTimeForFlappingInterface seconds, allow enough time for up to three queries (0, 1, and 4 seconds) // plus three seconds for "response delay" before removing the reconfirmed records from the cache. #define kDefaultReconfirmTimeForFlappingInterface (kDefaultQueryDelayTimeForFlappingInterface + ((mDNSu32)mDNSPlatformOneSecond * 7)) mDNSexport mStatus mDNS_Reconfirm_internal(mDNS *const m, CacheRecord *const rr, mDNSu32 interval) { if (interval < kMinimumReconfirmTime) interval = kMinimumReconfirmTime; if (interval > 0x10000000) // Make sure interval doesn't overflow when we multiply by four below interval = 0x10000000; // If the expected expiration time for this record is more than interval+33%, then accelerate its expiration if (RRExpireTime(rr) - m->timenow > (mDNSs32)((interval * 4) / 3)) { // Add a 33% random amount to the interval, to avoid synchronization between multiple hosts // For all the reconfirmations in a given batch, we want to use the same random value // so that the reconfirmation questions can be grouped into a single query packet if (!m->RandomReconfirmDelay) m->RandomReconfirmDelay = 1 + mDNSRandom(FutureTime); interval += m->RandomReconfirmDelay % ((interval/3) + 1); rr->TimeRcvd = m->timenow - (mDNSs32)interval * 3; rr->resrec.rroriginalttl = (interval * 4 + mDNSPlatformOneSecond - 1) / mDNSPlatformOneSecond; SetNextCacheCheckTimeForRecord(m, rr); } debugf("mDNS_Reconfirm_internal:%6ld ticks to go for %s %p", RRExpireTime(rr) - m->timenow, CRDisplayString(m, rr), rr->CRActiveQuestion); return(mStatus_NoError); } // BuildQuestion puts a question into a DNS Query packet and if successful, updates the value of queryptr. // It also appends to the list of known answer records that need to be included, // and updates the forcast for the size of the known answer section. mDNSlocal mDNSBool BuildQuestion(mDNS *const m, const NetworkInterfaceInfo *intf, DNSMessage *query, mDNSu8 **queryptr, DNSQuestion *q, CacheRecord ***kalistptrptr, mDNSu32 *answerforecast) { mDNSBool ucast = (q->LargeAnswers || q->RequestUnicast) && m->CanReceiveUnicastOn5353 && intf->SupportsUnicastMDNSResponse; mDNSu16 ucbit = (mDNSu16)(ucast ? kDNSQClass_UnicastResponse : 0); const mDNSu8 *const limit = query->data + NormalMaxDNSMessageData; mDNSu8 *newptr = putQuestion(query, *queryptr, limit - *answerforecast, &q->qname, q->qtype, (mDNSu16)(q->qclass | ucbit)); if (!newptr) { debugf("BuildQuestion: No more space in this packet for question %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return(mDNSfalse); } else { mDNSu32 forecast = *answerforecast; const CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); CacheRecord *cr; CacheRecord **ka = *kalistptrptr; // Make a working copy of the pointer we're going to update for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) // If we have a resource record in our cache, if (cr->resrec.InterfaceID == q->SendQNow && // received on this interface !(cr->resrec.RecordType & kDNSRecordTypeUniqueMask) && // which is a shared (i.e. not unique) record type cr->NextInKAList == mDNSNULL && ka != &cr->NextInKAList && // which is not already in the known answer list cr->resrec.rdlength <= SmallRecordLimit && // which is small enough to sensibly fit in the packet SameNameCacheRecordAnswersQuestion(cr, q) && // which answers our question cr->TimeRcvd + TicksTTL(cr)/2 - m->timenow > // and its half-way-to-expiry time is at least 1 second away mDNSPlatformOneSecond) // (also ensures we never include goodbye records with TTL=1) { // We don't want to include unique records in the Known Answer section. The Known Answer section // is intended to suppress floods of shared-record replies from many other devices on the network. // That concept really does not apply to unique records, and indeed if we do send a query for // which we have a unique record already in our cache, then including that unique record as a // Known Answer, so as to suppress the only answer we were expecting to get, makes little sense. *ka = cr; // Link this record into our known answer chain ka = &cr->NextInKAList; // We forecast: compressed name (2) type (2) class (2) TTL (4) rdlength (2) rdata (n) forecast += 12 + cr->resrec.rdestimate; // If we're trying to put more than one question in this packet, and it doesn't fit // then undo that last question and try again next time if (query->h.numQuestions > 1 && newptr + forecast >= limit) { query->h.numQuestions--; debugf("BuildQuestion: Retracting question %##s (%s) new forecast total %d, total questions %d", q->qname.c, DNSTypeName(q->qtype), newptr + forecast - query->data, query->h.numQuestions); ka = *kalistptrptr; // Go back to where we started and retract these answer records while (*ka) { CacheRecord *c = *ka; *ka = mDNSNULL; ka = &c->NextInKAList; } return(mDNSfalse); // Return false, so we'll try again in the next packet } } // Success! Update our state pointers, increment UnansweredQueries as appropriate, and return *queryptr = newptr; // Update the packet pointer *answerforecast = forecast; // Update the forecast *kalistptrptr = ka; // Update the known answer list pointer if (ucast) q->ExpectUnicastResp = NonZeroTime(m->timenow); for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) // For every resource record in our cache, if (cr->resrec.InterfaceID == q->SendQNow && // received on this interface cr->NextInKAList == mDNSNULL && ka != &cr->NextInKAList && // which is not in the known answer list SameNameCacheRecordAnswersQuestion(cr, q)) // which answers our question { cr->UnansweredQueries++; // indicate that we're expecting a response cr->LastUnansweredTime = m->timenow; SetNextCacheCheckTimeForRecord(m, cr); } return(mDNStrue); } } // When we have a query looking for a specified name, but there appear to be no answers with // that name, ReconfirmAntecedents() is called with depth=0 to start the reconfirmation process // for any records in our cache that reference the given name (e.g. PTR and SRV records). // For any such cache record we find, we also recursively call ReconfirmAntecedents() for *its* name. // We increment depth each time we recurse, to guard against possible infinite loops, with a limit of 5. // A typical reconfirmation scenario might go like this: // Depth 0: Name "myhost.local" has no address records // Depth 1: SRV "My Service._example._tcp.local." refers to "myhost.local"; may be stale // Depth 2: PTR "_example._tcp.local." refers to "My Service"; may be stale // Depth 3: PTR "_services._dns-sd._udp.local." refers to "_example._tcp.local."; may be stale // Currently depths 4 and 5 are not expected to occur; if we did get to depth 5 we'd reconfim any records we // found referring to the given name, but not recursively descend any further reconfirm *their* antecedents. mDNSlocal void ReconfirmAntecedents(mDNS *const m, const domainname *const name, const mDNSu32 namehash, const mDNSInterfaceID InterfaceID, const int depth) { mDNSu32 slot; const CacheGroup *cg; CacheRecord *cr; debugf("ReconfirmAntecedents (depth=%d) for %##s", depth, name->c); if (!InterfaceID) return; // mDNS records have a non-zero InterfaceID. If InterfaceID is 0, then there's nothing to do. FORALL_CACHERECORDS(slot, cg, cr) { const domainname *crtarget; if (cr->resrec.InterfaceID != InterfaceID) continue; // Skip non-mDNS records and mDNS records from other interfaces. if (cr->resrec.rdatahash != namehash) continue; // Skip records whose rdata hash doesn't match the name hash. crtarget = GetRRDomainNameTarget(&cr->resrec); if (crtarget && SameDomainName(crtarget, name)) { LogInfo("ReconfirmAntecedents: Reconfirming (depth=%d, InterfaceID=%p) %s", depth, InterfaceID, CRDisplayString(m, cr)); mDNS_Reconfirm_internal(m, cr, kDefaultReconfirmTimeForNoAnswer); if (depth < 5) ReconfirmAntecedents(m, cr->resrec.name, cr->resrec.namehash, InterfaceID, depth+1); } } } // If we get no answer for a AAAA query, then before doing an automatic implicit ReconfirmAntecedents // we check if we have an address record for the same name. If we do have an IPv4 address for a given // name but not an IPv6 address, that's okay (it just means the device doesn't do IPv6) so the failure // to get a AAAA response is not grounds to doubt the PTR/SRV chain that lead us to that name. mDNSlocal const CacheRecord *CacheHasAddressTypeForName(mDNS *const m, const domainname *const name, const mDNSu32 namehash) { CacheGroup *const cg = CacheGroupForName(m, namehash, name); const CacheRecord *cr = cg ? cg->members : mDNSNULL; while (cr && !RRTypeIsAddressType(cr->resrec.rrtype)) cr=cr->next; return(cr); } mDNSlocal const CacheRecord *FindSPSInCache1(mDNS *const m, const DNSQuestion *const q, const CacheRecord *const c0, const CacheRecord *const c1) { #ifndef SPC_DISABLED CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); const CacheRecord *cr, *bestcr = mDNSNULL; mDNSu32 bestmetric = 1000000; for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) if (cr->resrec.rrtype == kDNSType_PTR && cr->resrec.rdlength >= 6) // If record is PTR type, with long enough name, if (cr != c0 && cr != c1) // that's not one we've seen before, if (SameNameCacheRecordAnswersQuestion(cr, q)) // and answers our browse query, if (!IdenticalSameNameRecord(&cr->resrec, &m->SPSRecords.RR_PTR.resrec)) // and is not our own advertised service... { mDNSu32 metric = SPSMetric(cr->resrec.rdata->u.name.c); if (bestmetric > metric) { bestmetric = metric; bestcr = cr; } } return(bestcr); #else // SPC_DISABLED (void) m; (void) q; (void) c0; (void) c1; (void) c1; return mDNSNULL; #endif // SPC_DISABLED } mDNSlocal void CheckAndSwapSPS(const CacheRecord **sps1, const CacheRecord **sps2) { const CacheRecord *swap_sps; mDNSu32 metric1, metric2; if (!(*sps1) || !(*sps2)) return; metric1 = SPSMetric((*sps1)->resrec.rdata->u.name.c); metric2 = SPSMetric((*sps2)->resrec.rdata->u.name.c); if (!SPSFeatures((*sps1)->resrec.rdata->u.name.c) && SPSFeatures((*sps2)->resrec.rdata->u.name.c) && (metric2 >= metric1)) { swap_sps = *sps1; *sps1 = *sps2; *sps2 = swap_sps; } } mDNSlocal void ReorderSPSByFeature(const CacheRecord *sps[3]) { CheckAndSwapSPS(&sps[0], &sps[1]); CheckAndSwapSPS(&sps[0], &sps[2]); CheckAndSwapSPS(&sps[1], &sps[2]); } // Finds the three best Sleep Proxies we currently have in our cache mDNSexport void FindSPSInCache(mDNS *const m, const DNSQuestion *const q, const CacheRecord *sps[3]) { sps[0] = FindSPSInCache1(m, q, mDNSNULL, mDNSNULL); sps[1] = !sps[0] ? mDNSNULL : FindSPSInCache1(m, q, sps[0], mDNSNULL); sps[2] = !sps[1] ? mDNSNULL : FindSPSInCache1(m, q, sps[0], sps[1]); // SPS is already sorted by metric. We want to move the entries to the beginning of the array // only if they have equally good metric and support features. ReorderSPSByFeature(sps); } // Only DupSuppressInfos newer than the specified 'time' are allowed to remain active mDNSlocal void ExpireDupSuppressInfo(DupSuppressInfo ds[DupSuppressInfoSize], mDNSs32 time) { int i; for (i=0; iIPv4Available; // If this interface doesn't do v4, we don't need to find a v4 duplicate of this query mDNSBool v6 = !intf->IPv6Available; // If this interface doesn't do v6, we don't need to find a v6 duplicate of this query for (i=0; iInterfaceID) { if (ds[i].Type == mDNSAddrType_IPv4) v4 = mDNStrue; else if (ds[i].Type == mDNSAddrType_IPv6) v6 = mDNStrue; if (v4 && v6) return(mDNStrue); } return(mDNSfalse); } mDNSlocal void RecordDupSuppressInfo(DupSuppressInfo ds[DupSuppressInfoSize], mDNSs32 Time, mDNSInterfaceID InterfaceID, mDNSs32 Type) { int i, j; // See if we have this one in our list somewhere already for (i=0; i= DupSuppressInfoSize) { i = 0; for (j=1; jInterfaceID; domainname *d = &q->qname; // We can't send magic packets without knowing which interface to send it on. if (InterfaceID == mDNSInterface_Any || LocalOnlyOrP2PInterface(InterfaceID)) { LogMsg("mDNSSendWakeOnResolve: ERROR!! Invalid InterfaceID %p for question %##s", InterfaceID, q->qname.c); return; } // Split MAC@IPAddress and pass them separately len = d->c[0]; cnt = 0; for (i = 1; i < len; i++) { if (d->c[i] == '@') { char EthAddr[18]; // ethernet adddress : 12 bytes + 5 ":" + 1 NULL byte char IPAddr[47]; // Max IP address len: 46 bytes (IPv6) + 1 NULL byte if (cnt != 5) { LogMsg("mDNSSendWakeOnResolve: ERROR!! Malformed Ethernet address %##s, cnt %d", q->qname.c, cnt); return; } if ((i - 1) > (int) (sizeof(EthAddr) - 1)) { LogMsg("mDNSSendWakeOnResolve: ERROR!! Malformed Ethernet address %##s, length %d", q->qname.c, i - 1); return; } if ((len - i) > (int)(sizeof(IPAddr) - 1)) { LogMsg("mDNSSendWakeOnResolve: ERROR!! Malformed IP address %##s, length %d", q->qname.c, len - i); return; } mDNSPlatformMemCopy(EthAddr, &d->c[1], i - 1); EthAddr[i - 1] = 0; mDNSPlatformMemCopy(IPAddr, &d->c[i + 1], len - i); IPAddr[len - i] = 0; m->mDNSStats.WakeOnResolves++; mDNSPlatformSendWakeupPacket(InterfaceID, EthAddr, IPAddr, InitialWakeOnResolveCount - q->WakeOnResolveCount); return; } else if (d->c[i] == ':') cnt++; } LogMsg("mDNSSendWakeOnResolve: ERROR!! Malformed WakeOnResolve name %##s", q->qname.c); } mDNSlocal mDNSBool AccelerateThisQuery(mDNS *const m, DNSQuestion *q) { // If more than 90% of the way to the query time, we should unconditionally accelerate it if (TimeToSendThisQuestion(q, m->timenow + q->ThisQInterval/10)) return(mDNStrue); // If half-way to next scheduled query time, only accelerate if it will add less than 512 bytes to the packet if (TimeToSendThisQuestion(q, m->timenow + q->ThisQInterval/2)) { // We forecast: qname (n) type (2) class (2) mDNSu32 forecast = (mDNSu32)DomainNameLength(&q->qname) + 4; const CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); const CacheRecord *cr; for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) // If we have a resource record in our cache, if (cr->resrec.rdlength <= SmallRecordLimit && // which is small enough to sensibly fit in the packet SameNameCacheRecordAnswersQuestion(cr, q) && // which answers our question cr->TimeRcvd + TicksTTL(cr)/2 - m->timenow >= 0 && // and it is less than half-way to expiry cr->NextRequiredQuery - (m->timenow + q->ThisQInterval) > 0) // and we'll ask at least once again before NextRequiredQuery { // We forecast: compressed name (2) type (2) class (2) TTL (4) rdlength (2) rdata (n) forecast += 12 + cr->resrec.rdestimate; if (forecast >= 512) return(mDNSfalse); // If this would add 512 bytes or more to the packet, don't accelerate } return(mDNStrue); } return(mDNSfalse); } // How Standard Queries are generated: // 1. The Question Section contains the question // 2. The Additional Section contains answers we already know, to suppress duplicate responses // How Probe Queries are generated: // 1. The Question Section contains queries for the name we intend to use, with QType=ANY because // if some other host is already using *any* records with this name, we want to know about it. // 2. The Authority Section contains the proposed values we intend to use for one or more // of our records with that name (analogous to the Update section of DNS Update packets) // because if some other host is probing at the same time, we each want to know what the other is // planning, in order to apply the tie-breaking rule to see who gets to use the name and who doesn't. mDNSlocal void SendQueries(mDNS *const m) { mDNSu32 slot; CacheGroup *cg; CacheRecord *cr; AuthRecord *ar; int pktcount = 0; DNSQuestion *q; // For explanation of maxExistingQuestionInterval logic, see comments for maxExistingAnnounceInterval mDNSs32 maxExistingQuestionInterval = 0; const NetworkInterfaceInfo *intf = GetFirstActiveInterface(m->HostInterfaces); CacheRecord *KnownAnswerList = mDNSNULL; // 1. If time for a query, work out what we need to do // We're expecting to send a query anyway, so see if any expiring cache records are close enough // to their NextRequiredQuery to be worth batching them together with this one FORALL_CACHERECORDS(slot, cg, cr) { if (cr->CRActiveQuestion && cr->UnansweredQueries < MaxUnansweredQueries) { if (m->timenow + TicksTTL(cr)/50 - cr->NextRequiredQuery >= 0) { debugf("Sending %d%% cache expiration query for %s", 80 + 5 * cr->UnansweredQueries, CRDisplayString(m, cr)); q = cr->CRActiveQuestion; ExpireDupSuppressInfoOnInterface(q->DupSuppress, m->timenow - TicksTTL(cr)/20, cr->resrec.InterfaceID); // For uDNS queries (TargetQID non-zero) we adjust LastQTime, // and bump UnansweredQueries so that we don't spin trying to send the same cache expiration query repeatedly if (!mDNSOpaque16IsZero(q->TargetQID)) { q->LastQTime = m->timenow - q->ThisQInterval; cr->UnansweredQueries++; m->mDNSStats.CacheRefreshQueries++; } else if (q->SendQNow == mDNSNULL) { q->SendQNow = cr->resrec.InterfaceID; } else if (q->SendQNow != cr->resrec.InterfaceID) { q->SendQNow = mDNSInterfaceMark; } // Indicate that this question was marked for sending // to update an existing cached answer record. // The browse throttling logic below uses this to determine // if the query should be sent. if (mDNSOpaque16IsZero(q->TargetQID)) q->CachedAnswerNeedsUpdate = mDNStrue; } } } // Scan our list of questions to see which: // *WideArea* queries need to be sent // *unicast* queries need to be sent // *multicast* queries we're definitely going to send if (m->CurrentQuestion) LogMsg("SendQueries ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) { q = m->CurrentQuestion; if (mDNSOpaque16IsZero(q->TargetQID) && TimeToSendThisQuestion(q, m->timenow)) { //LogInfo("Time to send %##s (%s) %d", q->qname.c, DNSTypeName(q->qtype), m->timenow - NextQSendTime(q)); q->SendQNow = mDNSInterfaceMark; // Mark this question for sending on all interfaces if (maxExistingQuestionInterval < q->ThisQInterval) maxExistingQuestionInterval = q->ThisQInterval; } // If m->CurrentQuestion wasn't modified out from under us, advance it now // We can't do this at the start of the loop because uDNS_CheckCurrentQuestion() depends on having // m->CurrentQuestion point to the right question if (q == m->CurrentQuestion) m->CurrentQuestion = m->CurrentQuestion->next; } while (m->CurrentQuestion) { LogInfo("SendQueries question loop 1: Skipping NewQuestion %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->CurrentQuestion->next; } m->CurrentQuestion = mDNSNULL; // Scan our list of questions // (a) to see if there are any more that are worth accelerating, and // (b) to update the state variables for *all* the questions we're going to send // Note: Don't set NextScheduledQuery until here, because uDNS_CheckCurrentQuestion in the loop above can add new questions to the list, // which causes NextScheduledQuery to get (incorrectly) set to m->timenow. Setting it here is the right place, because the very // next thing we do is scan the list and call SetNextQueryTime() for every question we find, so we know we end up with the right value. m->NextScheduledQuery = m->timenow + FutureTime; for (q = m->Questions; q && q != m->NewQuestions; q=q->next) { if (mDNSOpaque16IsZero(q->TargetQID) && (q->SendQNow || (ActiveQuestion(q) && q->ThisQInterval <= maxExistingQuestionInterval && AccelerateThisQuery(m,q)))) { // If at least halfway to next query time, advance to next interval // If less than halfway to next query time, then // treat this as logically a repeat of the last transmission, without advancing the interval if (m->timenow - (q->LastQTime + (q->ThisQInterval/2)) >= 0) { // If we have reached the answer threshold for this question, // don't send it again until MaxQuestionInterval unless: // one of its cached answers needs to be refreshed, // or it's the initial query for a kDNSServiceFlagsThresholdFinder mode browse. if (q->BrowseThreshold && (q->CurrentAnswers >= q->BrowseThreshold) && (q->CachedAnswerNeedsUpdate == mDNSfalse) && !((q->flags & kDNSServiceFlagsThresholdFinder) && (q->ThisQInterval == InitialQuestionInterval))) { q->SendQNow = mDNSNULL; q->ThisQInterval = MaxQuestionInterval; q->LastQTime = m->timenow; q->RequestUnicast = 0; LogInfo("SendQueries: (%s) %##s reached threshold of %d answers", DNSTypeName(q->qtype), q->qname.c, q->BrowseThreshold); } else { // Mark this question for sending on all interfaces q->SendQNow = mDNSInterfaceMark; q->ThisQInterval *= QuestionIntervalStep; } debugf("SendQueries: %##s (%s) next interval %d seconds RequestUnicast = %d", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval / InitialQuestionInterval, q->RequestUnicast); if (q->ThisQInterval > MaxQuestionInterval) { q->ThisQInterval = MaxQuestionInterval; } else if (mDNSOpaque16IsZero(q->TargetQID) && q->InterfaceID && q->CurrentAnswers == 0 && q->ThisQInterval == InitialQuestionInterval * QuestionIntervalStep3 && !q->RequestUnicast && !(RRTypeIsAddressType(q->qtype) && CacheHasAddressTypeForName(m, &q->qname, q->qnamehash))) { // Generally don't need to log this. // It's not especially noteworthy if a query finds no results -- this usually happens for domain // enumeration queries in the LL subdomain (e.g. "db._dns-sd._udp.0.0.254.169.in-addr.arpa") // and when there simply happen to be no instances of the service the client is looking // for (e.g. iTunes is set to look for RAOP devices, and the current network has none). debugf("SendQueries: Zero current answers for %##s (%s); will reconfirm antecedents", q->qname.c, DNSTypeName(q->qtype)); // Sending third query, and no answers yet; time to begin doubting the source ReconfirmAntecedents(m, &q->qname, q->qnamehash, q->InterfaceID, 0); } } // Mark for sending. (If no active interfaces, then don't even try.) q->SendOnAll = (q->SendQNow == mDNSInterfaceMark); if (q->SendOnAll) { q->SendQNow = !intf ? mDNSNULL : (q->InterfaceID) ? q->InterfaceID : intf->InterfaceID; q->LastQTime = m->timenow; } // If we recorded a duplicate suppression for this question less than half an interval ago, // then we consider it recent enough that we don't need to do an identical query ourselves. ExpireDupSuppressInfo(q->DupSuppress, m->timenow - q->ThisQInterval/2); q->LastQTxTime = m->timenow; q->RecentAnswerPkts = 0; if (q->RequestUnicast) q->RequestUnicast--; } // For all questions (not just the ones we're sending) check what the next scheduled event will be // We don't need to consider NewQuestions here because for those we'll set m->NextScheduledQuery in AnswerNewQuestion SetNextQueryTime(m,q); } // 2. Scan our authoritative RR list to see what probes we might need to send m->NextScheduledProbe = m->timenow + FutureTime; if (m->CurrentRecord) LogMsg("SendQueries ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { ar = m->CurrentRecord; m->CurrentRecord = ar->next; if (!AuthRecord_uDNS(ar) && ar->resrec.RecordType == kDNSRecordTypeUnique) // For all records that are still probing... { // 1. If it's not reached its probe time, just make sure we update m->NextScheduledProbe correctly if (m->timenow - (ar->LastAPTime + ar->ThisAPInterval) < 0) { SetNextAnnounceProbeTime(m, ar); } // 2. else, if it has reached its probe time, mark it for sending and then update m->NextScheduledProbe correctly else if (ar->ProbeCount) { if (ar->AddressProxy.type == mDNSAddrType_IPv4) { // There's a problem here. If a host is waking up, and we probe to see if it responds, then // it will see those ARP probes as signalling intent to use the address, so it picks a different one. // A more benign way to find out if a host is responding to ARPs might be send a standard ARP *request* // (using our sender IP address) instead of an ARP *probe* (using all-zero sender IP address). // A similar concern may apply to the NDP Probe too. -- SC LogSPS("SendQueries ARP Probe %d %s %s", ar->ProbeCount, InterfaceNameForID(m, ar->resrec.InterfaceID), ARDisplayString(m,ar)); SendARP(m, 1, ar, &zerov4Addr, &zeroEthAddr, &ar->AddressProxy.ip.v4, &ar->WakeUp.IMAC); } else if (ar->AddressProxy.type == mDNSAddrType_IPv6) { LogSPS("SendQueries NDP Probe %d %s %s", ar->ProbeCount, InterfaceNameForID(m, ar->resrec.InterfaceID), ARDisplayString(m,ar)); // IPv6 source = zero // No target hardware address // IPv6 target address is address we're probing // Ethernet destination address is Ethernet interface address of the Sleep Proxy client we're probing SendNDP(m, NDP_Sol, 0, ar, &zerov6Addr, mDNSNULL, &ar->AddressProxy.ip.v6, &ar->WakeUp.IMAC); } // Mark for sending. (If no active interfaces, then don't even try.) ar->SendRNow = (!intf || ar->WakeUp.HMAC.l[0]) ? mDNSNULL : ar->resrec.InterfaceID ? ar->resrec.InterfaceID : intf->InterfaceID; ar->LastAPTime = m->timenow; // When we have a late conflict that resets a record to probing state we use a special marker value greater // than DefaultProbeCountForTypeUnique. Here we detect that state and reset ar->ProbeCount back to the right value. if (ar->ProbeCount > DefaultProbeCountForTypeUnique) ar->ProbeCount = DefaultProbeCountForTypeUnique; ar->ProbeCount--; SetNextAnnounceProbeTime(m, ar); if (ar->ProbeCount == 0) { // If this is the last probe for this record, then see if we have any matching records // on our duplicate list which should similarly have their ProbeCount cleared to zero... AuthRecord *r2; for (r2 = m->DuplicateRecords; r2; r2=r2->next) if (r2->resrec.RecordType == kDNSRecordTypeUnique && RecordIsLocalDuplicate(r2, ar)) r2->ProbeCount = 0; // ... then acknowledge this record to the client. // We do this optimistically, just as we're about to send the third probe. // This helps clients that both advertise and browse, and want to filter themselves // from the browse results list, because it helps ensure that the registration // confirmation will be delivered 1/4 second *before* the browse "add" event. // A potential downside is that we could deliver a registration confirmation and then find out // moments later that there's a name conflict, but applications have to be prepared to handle // late conflicts anyway (e.g. on connection of network cable, etc.), so this is nothing new. if (!ar->Acknowledged) AcknowledgeRecord(m, ar); } } // else, if it has now finished probing, move it to state Verified, // and update m->NextScheduledResponse so it will be announced else { if (!ar->Acknowledged) AcknowledgeRecord(m, ar); // Defensive, just in case it got missed somehow ar->resrec.RecordType = kDNSRecordTypeVerified; ar->ThisAPInterval = DefaultAnnounceIntervalForTypeUnique; ar->LastAPTime = m->timenow - DefaultAnnounceIntervalForTypeUnique; SetNextAnnounceProbeTime(m, ar); } } } m->CurrentRecord = m->DuplicateRecords; while (m->CurrentRecord) { ar = m->CurrentRecord; m->CurrentRecord = ar->next; if (ar->resrec.RecordType == kDNSRecordTypeUnique && ar->ProbeCount == 0 && !ar->Acknowledged) AcknowledgeRecord(m, ar); } // 3. Now we know which queries and probes we're sending, // go through our interface list sending the appropriate queries on each interface while (intf) { int OwnerRecordSpace = (m->AnnounceOwner && intf->MAC.l[0]) ? DNSOpt_Header_Space + DNSOpt_Owner_Space(&m->PrimaryMAC, &intf->MAC) : 0; int TraceRecordSpace = (mDNS_McastTracingEnabled && MDNS_TRACER) ? DNSOpt_Header_Space + DNSOpt_TraceData_Space : 0; mDNSu8 *queryptr = m->omsg.data; mDNSBool useBackgroundTrafficClass = mDNSfalse; // set if we should use background traffic class InitializeDNSMessage(&m->omsg.h, zeroID, QueryFlags); if (KnownAnswerList) verbosedebugf("SendQueries: KnownAnswerList set... Will continue from previous packet"); if (!KnownAnswerList) { // Start a new known-answer list CacheRecord **kalistptr = &KnownAnswerList; mDNSu32 answerforecast = OwnerRecordSpace + TraceRecordSpace; // Start by assuming we'll need at least enough space to put the Owner+Tracer Option // Put query questions in this packet for (q = m->Questions; q && q != m->NewQuestions; q=q->next) { if (mDNSOpaque16IsZero(q->TargetQID) && (q->SendQNow == intf->InterfaceID)) { mDNSBool Suppress = mDNSfalse; debugf("SendQueries: %s question for %##s (%s) at %d forecast total %d", SuppressOnThisInterface(q->DupSuppress, intf) ? "Suppressing" : "Putting ", q->qname.c, DNSTypeName(q->qtype), queryptr - m->omsg.data, queryptr + answerforecast - m->omsg.data); // If interface is P2P type, verify that query should be sent over it. if (!mDNSPlatformValidQuestionForInterface(q, intf)) { q->SendQNow = (q->InterfaceID || !q->SendOnAll) ? mDNSNULL : GetNextActiveInterfaceID(intf); } // If we're suppressing this question, or we successfully put it, update its SendQNow state else if ((Suppress = SuppressOnThisInterface(q->DupSuppress, intf)) || BuildQuestion(m, intf, &m->omsg, &queryptr, q, &kalistptr, &answerforecast)) { if (Suppress) m->mDNSStats.DupQuerySuppressions++; q->SendQNow = (q->InterfaceID || !q->SendOnAll) ? mDNSNULL : GetNextActiveInterfaceID(intf); if (q->WakeOnResolveCount) { mDNSSendWakeOnResolve(m, q); q->WakeOnResolveCount--; } // use background traffic class if any included question requires it if (q->UseBackgroundTraffic) { useBackgroundTrafficClass = mDNStrue; } } } } // Put probe questions in this packet for (ar = m->ResourceRecords; ar; ar=ar->next) { if (ar->SendRNow != intf->InterfaceID) continue; // If interface is a P2P variant, verify that the probe should be sent over it. if (!mDNSPlatformValidRecordForInterface(ar, intf->InterfaceID)) { ar->SendRNow = (ar->resrec.InterfaceID) ? mDNSNULL : GetNextActiveInterfaceID(intf); ar->IncludeInProbe = mDNSfalse; } else { mDNSBool ucast = (ar->ProbeCount >= DefaultProbeCountForTypeUnique-1) && m->CanReceiveUnicastOn5353 && intf->SupportsUnicastMDNSResponse; mDNSu16 ucbit = (mDNSu16)(ucast ? kDNSQClass_UnicastResponse : 0); const mDNSu8 *const limit = m->omsg.data + (m->omsg.h.numQuestions ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData); // We forecast: compressed name (2) type (2) class (2) TTL (4) rdlength (2) rdata (n) mDNSu32 forecast = answerforecast + 12 + ar->resrec.rdestimate; mDNSBool putProbe = mDNStrue; mDNSu16 qclass = ar->resrec.rrclass | ucbit; {// Determine if this probe question is already in packet's dns message const mDNSu8 *questionptr = m->omsg.data; DNSQuestion question; mDNSu16 n; for (n = 0; n < m->omsg.h.numQuestions && questionptr; n++) { questionptr = getQuestion(&m->omsg, questionptr, limit, mDNSInterface_Any, &question); if (questionptr && (question.qtype == kDNSQType_ANY) && (question.qclass == qclass) && (question.qnamehash == ar->resrec.namehash) && SameDomainName(&question.qname, ar->resrec.name)) { putProbe = mDNSfalse; // set to false if already in message break; } } } if (putProbe) { mDNSu8 *newptr = putQuestion(&m->omsg, queryptr, limit - forecast, ar->resrec.name, kDNSQType_ANY, qclass); if (newptr) { queryptr = newptr; answerforecast = forecast; ar->SendRNow = (ar->resrec.InterfaceID) ? mDNSNULL : GetNextActiveInterfaceID(intf); ar->IncludeInProbe = mDNStrue; verbosedebugf("SendQueries: Put Question %##s (%s) probecount %d InterfaceID= %d %d %d", ar->resrec.name->c, DNSTypeName(ar->resrec.rrtype), ar->ProbeCount, ar->resrec.InterfaceID, ar->resrec.rdestimate, answerforecast); } } else { ar->SendRNow = (ar->resrec.InterfaceID) ? mDNSNULL : GetNextActiveInterfaceID(intf); ar->IncludeInProbe = mDNStrue; } } } } // Put our known answer list (either new one from this question or questions, or remainder of old one from last time) while (KnownAnswerList) { CacheRecord *ka = KnownAnswerList; mDNSu32 SecsSinceRcvd = ((mDNSu32)(m->timenow - ka->TimeRcvd)) / mDNSPlatformOneSecond; mDNSu8 *newptr = PutResourceRecordTTLWithLimit(&m->omsg, queryptr, &m->omsg.h.numAnswers, &ka->resrec, ka->resrec.rroriginalttl - SecsSinceRcvd, m->omsg.data + NormalMaxDNSMessageData - OwnerRecordSpace - TraceRecordSpace); if (newptr) { verbosedebugf("SendQueries: Put %##s (%s) at %d - %d", ka->resrec.name->c, DNSTypeName(ka->resrec.rrtype), queryptr - m->omsg.data, newptr - m->omsg.data); queryptr = newptr; KnownAnswerList = ka->NextInKAList; ka->NextInKAList = mDNSNULL; } else { // If we ran out of space and we have more than one question in the packet, that's an error -- // we shouldn't have put more than one question if there was a risk of us running out of space. if (m->omsg.h.numQuestions > 1) LogMsg("SendQueries: Put %d answers; No more space for known answers", m->omsg.h.numAnswers); m->omsg.h.flags.b[0] |= kDNSFlag0_TC; break; } } for (ar = m->ResourceRecords; ar; ar=ar->next) { if (ar->IncludeInProbe) { mDNSu8 *newptr = PutResourceRecord(&m->omsg, queryptr, &m->omsg.h.numAuthorities, &ar->resrec); ar->IncludeInProbe = mDNSfalse; if (newptr) queryptr = newptr; else LogMsg("SendQueries: How did we fail to have space for the Update record %s", ARDisplayString(m,ar)); } } if (queryptr > m->omsg.data) { // If we have data to send, add OWNER/TRACER/OWNER+TRACER option if necessary, then send packet if (OwnerRecordSpace || TraceRecordSpace) { AuthRecord opt; mDNS_SetupResourceRecord(&opt, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); opt.resrec.rrclass = NormalMaxDNSMessageData; opt.resrec.rdlength = sizeof(rdataOPT); opt.resrec.rdestimate = sizeof(rdataOPT); if (OwnerRecordSpace && TraceRecordSpace) { opt.resrec.rdlength += sizeof(rdataOPT); // Two options in this OPT record opt.resrec.rdestimate += sizeof(rdataOPT); SetupOwnerOpt(m, intf, &opt.resrec.rdata->u.opt[0]); SetupTracerOpt(m, &opt.resrec.rdata->u.opt[1]); } else if (OwnerRecordSpace) { SetupOwnerOpt(m, intf, &opt.resrec.rdata->u.opt[0]); } else if (TraceRecordSpace) { SetupTracerOpt(m, &opt.resrec.rdata->u.opt[0]); } queryptr = PutResourceRecordTTLWithLimit(&m->omsg, queryptr, &m->omsg.h.numAdditionals, &opt.resrec, opt.resrec.rroriginalttl, m->omsg.data + AbsoluteMaxDNSMessageData); if (!queryptr) { LogMsg("SendQueries: How did we fail to have space for %s %s OPT record (%d/%d/%d/%d) %s", OwnerRecordSpace ? "OWNER" : "", TraceRecordSpace ? "TRACER" : "", m->omsg.h.numQuestions, m->omsg.h.numAnswers, m->omsg.h.numAuthorities, m->omsg.h.numAdditionals, ARDisplayString(m, &opt)); } if (queryptr > m->omsg.data + NormalMaxDNSMessageData) { if (m->omsg.h.numQuestions != 1 || m->omsg.h.numAnswers != 0 || m->omsg.h.numAuthorities != 1 || m->omsg.h.numAdditionals != 1) LogMsg("SendQueries: Why did we generate oversized packet with %s %s OPT record %p %p %p (%d/%d/%d/%d) %s", OwnerRecordSpace ? "OWNER" : "", TraceRecordSpace ? "TRACER" : "", m->omsg.data, m->omsg.data + NormalMaxDNSMessageData, queryptr, m->omsg.h.numQuestions, m->omsg.h.numAnswers, m->omsg.h.numAuthorities, m->omsg.h.numAdditionals, ARDisplayString(m, &opt)); } } if ((m->omsg.h.flags.b[0] & kDNSFlag0_TC) && m->omsg.h.numQuestions > 1) LogMsg("SendQueries: Should not have more than one question (%d) in a truncated packet", m->omsg.h.numQuestions); debugf("SendQueries: Sending %d Question%s %d Answer%s %d Update%s on %d (%s)", m->omsg.h.numQuestions, m->omsg.h.numQuestions == 1 ? "" : "s", m->omsg.h.numAnswers, m->omsg.h.numAnswers == 1 ? "" : "s", m->omsg.h.numAuthorities, m->omsg.h.numAuthorities == 1 ? "" : "s", IIDPrintable(intf->InterfaceID), intf->ifname); if (intf->IPv4Available) mDNSSendDNSMessage(m, &m->omsg, queryptr, intf->InterfaceID, mDNSNULL, mDNSNULL, &AllDNSLinkGroup_v4, MulticastDNSPort, mDNSNULL, useBackgroundTrafficClass); if (intf->IPv6Available) mDNSSendDNSMessage(m, &m->omsg, queryptr, intf->InterfaceID, mDNSNULL, mDNSNULL, &AllDNSLinkGroup_v6, MulticastDNSPort, mDNSNULL, useBackgroundTrafficClass); if (!m->SuppressSending) m->SuppressSending = NonZeroTime(m->timenow + (mDNSPlatformOneSecond+9)/10); if (++pktcount >= 1000) { LogMsg("SendQueries exceeded loop limit %d: giving up", pktcount); break; } // There might be more records left in the known answer list, or more questions to send // on this interface, so go around one more time and try again. } else // Nothing more to send on this interface; go to next { const NetworkInterfaceInfo *next = GetFirstActiveInterface(intf->next); #if MDNS_DEBUGMSGS && 0 const char *const msg = next ? "SendQueries: Nothing more on %p; moving to %p" : "SendQueries: Nothing more on %p"; debugf(msg, intf, next); #endif intf = next; } } // 4. Final housekeeping // 4a. Debugging check: Make sure we announced all our records for (ar = m->ResourceRecords; ar; ar=ar->next) if (ar->SendRNow) { if (ar->ARType != AuthRecordLocalOnly && ar->ARType != AuthRecordP2P) LogInfo("SendQueries: No active interface %d to send probe: %d %s", IIDPrintable(ar->SendRNow), IIDPrintable(ar->resrec.InterfaceID), ARDisplayString(m, ar)); ar->SendRNow = mDNSNULL; } // 4b. When we have lingering cache records that we're keeping around for a few seconds in the hope // that their interface which went away might come back again, the logic will want to send queries // for those records, but we can't because their interface isn't here any more, so to keep the // state machine ticking over we just pretend we did so. // If the interface does not come back in time, the cache record will expire naturally FORALL_CACHERECORDS(slot, cg, cr) { if (cr->CRActiveQuestion && cr->UnansweredQueries < MaxUnansweredQueries) { if (m->timenow + TicksTTL(cr)/50 - cr->NextRequiredQuery >= 0) { cr->UnansweredQueries++; cr->CRActiveQuestion->SendQNow = mDNSNULL; SetNextCacheCheckTimeForRecord(m, cr); } } } // 4c. Debugging check: Make sure we sent all our planned questions // Do this AFTER the lingering cache records check above, because that will prevent spurious warnings for questions // we legitimately couldn't send because the interface is no longer available for (q = m->Questions; q; q=q->next) { if (q->SendQNow) { DNSQuestion *x; for (x = m->NewQuestions; x; x=x->next) if (x == q) break; // Check if this question is a NewQuestion // There will not be an active interface for questions applied to mDNSInterface_BLE // so don't log the warning in that case. if (q->InterfaceID != mDNSInterface_BLE) LogInfo("SendQueries: No active interface %d to send %s question: %d %##s (%s)", IIDPrintable(q->SendQNow), x ? "new" : "old", IIDPrintable(q->InterfaceID), q->qname.c, DNSTypeName(q->qtype)); q->SendQNow = mDNSNULL; } q->CachedAnswerNeedsUpdate = mDNSfalse; } } mDNSlocal void SendWakeup(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSEthAddr *EthAddr, mDNSOpaque48 *password, mDNSBool unicastOnly) { int i, j; mDNSu8 *ptr = m->omsg.data; NetworkInterfaceInfo *intf = FirstInterfaceForID(m, InterfaceID); if (!intf) { LogMsg("SendARP: No interface with InterfaceID %p found", InterfaceID); return; } // 0x00 Destination address for (i=0; i<6; i++) *ptr++ = EthAddr->b[i]; // 0x06 Source address (Note: Since we don't currently set the BIOCSHDRCMPLT option, BPF will fill in the real interface address for us) for (i=0; i<6; i++) *ptr++ = intf->MAC.b[0]; // 0x0C Ethertype (0x0842) *ptr++ = 0x08; *ptr++ = 0x42; // 0x0E Wakeup sync sequence for (i=0; i<6; i++) *ptr++ = 0xFF; // 0x14 Wakeup data for (j=0; j<16; j++) for (i=0; i<6; i++) *ptr++ = EthAddr->b[i]; // 0x74 Password for (i=0; i<6; i++) *ptr++ = password->b[i]; mDNSPlatformSendRawPacket(m->omsg.data, ptr, InterfaceID); if (!unicastOnly) { // For Ethernet switches that don't flood-foward packets with unknown unicast destination MAC addresses, // broadcast is the only reliable way to get a wakeup packet to the intended target machine. // For 802.11 WPA networks, where a sleeping target machine may have missed a broadcast/multicast // key rotation, unicast is the only way to get a wakeup packet to the intended target machine. // So, we send one of each, unicast first, then broadcast second. for (i=0; i<6; i++) m->omsg.data[i] = 0xFF; mDNSPlatformSendRawPacket(m->omsg.data, ptr, InterfaceID); } } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - RR List Management & Task Management #endif // Whenever a question is answered, reset its state so that we don't query // the network repeatedly. This happens first time when we answer the question and // and later when we refresh the cache. mDNSlocal void ResetQuestionState(mDNS *const m, DNSQuestion *q) { q->LastQTime = m->timenow; q->LastQTxTime = m->timenow; q->RecentAnswerPkts = 0; q->ThisQInterval = MaxQuestionInterval; q->RequestUnicast = 0; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) // Reset unansweredQueries so that we don't penalize this server later when we // start sending queries when the cache expires. q->unansweredQueries = 0; #endif debugf("ResetQuestionState: Set MaxQuestionInterval for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); } mDNSlocal void AdjustUnansweredQueries(mDNS *const m, CacheRecord *const rr) { const mDNSs32 expireTime = RRExpireTime(rr); const mDNSu32 interval = TicksTTL(rr) / 20; // Calculate 5% of the cache record's TTL. mDNSu32 rem; // If the record is expired or UnansweredQueries is already at the max, then return early. if (((m->timenow - expireTime) >= 0) || (rr->UnansweredQueries >= MaxUnansweredQueries)) return; if (interval == 0) { LogInfo("AdjustUnansweredQueries: WARNING: unusually small TTL (%d ticks) for %s", TicksTTL(rr), CRDisplayString(m, rr)); return; } // Calculate the number of whole 5% TTL intervals between now and expiration time. rem = ((mDNSu32)(expireTime - m->timenow)) / interval; // Calculate the expected number of remaining refresher queries. // Refresher queries are sent at the start of the last MaxUnansweredQueries intervals. if (rem > MaxUnansweredQueries) rem = MaxUnansweredQueries; // If the current number of remaining refresher queries is greater than expected, then at least one refresher query time // was missed. This can happen if the cache record didn't have an active question during any of the times at which // refresher queries would have been sent if the cache record did have an active question. The cache record's // UnansweredQueries count needs to be adjusted to avoid a burst of refresher queries being sent in an attempt to make up // for lost time. UnansweredQueries is set to the number of queries that would have been sent had the cache record had an // active question from the 80% point of its lifetime up to now, with one exception: if the number of expected remaining // refresher queries is zero (because timenow is beyond the 95% point), then UnansweredQueries is set to // MaxUnansweredQueries - 1 so that at least one refresher query is sent before the cache record expires. // Note: The cast is safe because rem is never greater than MaxUnansweredQueries; the comparison has to be signed. if ((MaxUnansweredQueries - rr->UnansweredQueries) > (mDNSs32)rem) { if (rem == 0) rem++; rr->UnansweredQueries = (mDNSu8)(MaxUnansweredQueries - rem); } } // Note: AnswerCurrentQuestionWithResourceRecord can call a user callback, which may change the record list and/or question list. // Any code walking either list must use the m->CurrentQuestion (and possibly m->CurrentRecord) mechanism to protect against this. // In fact, to enforce this, the routine will *only* answer the question currently pointed to by m->CurrentQuestion, // which will be auto-advanced (possibly to NULL) if the client callback cancels the question. mDNSexport void AnswerCurrentQuestionWithResourceRecord(mDNS *const m, CacheRecord *const rr, const QC_result AddRecord) { DNSQuestion *const q = m->CurrentQuestion; const mDNSBool followcname = FollowCNAME(q, &rr->resrec, AddRecord); verbosedebugf("AnswerCurrentQuestionWithResourceRecord:%4lu %s (%s) TTL %d %s", q->CurrentAnswers, AddRecord ? "Add" : "Rmv", MortalityDisplayString(rr->resrec.mortality), rr->resrec.rroriginalttl, CRDisplayString(m, rr)); // Normally we don't send out the unicast query if we have answered using our local only auth records e.g., /etc/hosts. // But if the query for "A" record has a local answer but query for "AAAA" record has no local answer, we might // send the AAAA query out which will come back with CNAME and will also answer the "A" query. To prevent that, // we check to see if that query already has a unique local answer. if (q->LOAddressAnswers) { LogInfo("AnswerCurrentQuestionWithResourceRecord: Question %p %##s (%s) not answering with record %s due to " "LOAddressAnswers %d", q, q->qname.c, DNSTypeName(q->qtype), ARDisplayString(m, rr), q->LOAddressAnswers); return; } if (q->Suppressed && (AddRecord != QC_suppressed)) { // If the query is suppressed, then we don't want to answer from the cache. But if this query is // supposed to time out, we still want to callback the clients. We do this only for TimeoutQuestions // that are timing out, which we know are answered with negative cache record when timing out. if (!q->TimeoutQuestion || rr->resrec.RecordType != kDNSRecordTypePacketNegative || (m->timenow - q->StopTime < 0)) return; } // Set the record to immortal if appropriate if (AddRecord == QC_add && Question_uDNS(q) && rr->resrec.RecordType != kDNSRecordTypePacketNegative && q->allowExpired != AllowExpired_None && rr->resrec.mortality == Mortality_Mortal ) rr->resrec.mortality = Mortality_Immortal; // Update a non-expired cache record to immortal if appropriate #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if ((AddRecord == QC_add) && Question_uDNS(q) && !followcname && !q->metrics.answered) { mDNSBool skipUpdate = mDNSfalse; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!q->dnsservice || (mdns_dns_service_get_resolver_type(q->dnsservice) != mdns_resolver_type_normal)) { skipUpdate = mDNStrue; } #endif if (!skipUpdate) { const domainname * queryName; mDNSu32 responseLatencyMs, querySendCount; mDNSBool isForCellular; queryName = q->metrics.originalQName ? q->metrics.originalQName : &q->qname; querySendCount = q->metrics.querySendCount; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (q->querier) { querySendCount += mdns_querier_get_send_count(q->querier); } isForCellular = mdns_dns_service_interface_is_cellular(q->dnsservice); #else isForCellular = (q->qDNSServer && q->qDNSServer->isCell); #endif if (q->metrics.querySendCount > 0) { responseLatencyMs = ((m->timenow - q->metrics.firstQueryTime) * 1000) / mDNSPlatformOneSecond; } else { responseLatencyMs = 0; } MetricsUpdateDNSQueryStats(queryName, q->qtype, &rr->resrec, querySendCount, q->metrics.expiredAnswerState, q->metrics.dnsOverTCPState, responseLatencyMs, isForCellular); } q->metrics.answered = mDNStrue; } #endif // Note: Use caution here. In the case of records with rr->DelayDelivery set, AnswerCurrentQuestionWithResourceRecord(... mDNStrue) // may be called twice, once when the record is received, and again when it's time to notify local clients. // If any counters or similar are added here, care must be taken to ensure that they are not double-incremented by this. if (AddRecord == QC_add && !q->DuplicateOf && rr->CRActiveQuestion != q && rr->resrec.mortality != Mortality_Ghost) { debugf("AnswerCurrentQuestionWithResourceRecord: Updating CRActiveQuestion from %p to %p for cache record %s, CurrentAnswer %d", rr->CRActiveQuestion, q, CRDisplayString(m,rr), q->CurrentAnswers); if (!rr->CRActiveQuestion) { m->rrcache_active++; // If not previously active, increment rrcache_active count AdjustUnansweredQueries(m, rr); // Adjust UnansweredQueries in case the record missed out on refresher queries } rr->CRActiveQuestion = q; // We know q is non-null SetNextCacheCheckTimeForRecord(m, rr); } // If this is: // (a) a no-cache add, where we've already done at least one 'QM' query, or // (b) a normal add, where we have at least one unique-type answer, // then there's no need to keep polling the network. // (If we have an answer in the cache, then we'll automatically ask again in time to stop it expiring.) // We do this for mDNS questions and uDNS one-shot questions, but not for // uDNS LongLived questions, because that would mess up our LLQ lease renewal timing. if ((AddRecord == QC_addnocache && !q->RequestUnicast) || (AddRecord == QC_add && (q->ExpectUnique || (rr->resrec.RecordType & kDNSRecordTypePacketUniqueMask)))) if (ActiveQuestion(q) && (mDNSOpaque16IsZero(q->TargetQID) || !q->LongLived)) { ResetQuestionState(m, q); } if (rr->DelayDelivery) return; // We'll come back later when CacheRecordDeferredAdd() calls us #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) // If DNS64StateMachine() returns true, then the question was restarted as a different question, so return. if (!mDNSOpaque16IsZero(q->TargetQID) && DNS64StateMachine(m, q, &rr->resrec, AddRecord)) return; #endif #ifdef USE_LIBIDN if (rr->resrec.RecordType == kDNSRecordTypePacketNegative) // If negative answer, check if we need to try Punycode conversion { domainname newname; if (PerformNextPunycodeConversion(q, &newname)) // Itertative Punycode conversion succeeded, so reissue question with new name { UDPSocket *const sock = q->LocalSocket; // Save old socket and transaction ID const mDNSOpaque16 id = q->TargetQID; q->LocalSocket = mDNSNULL; mDNS_StopQuery_internal(m, q); // Stop old query AssignDomainName(&q->qname, &newname); // Update qname q->qnamehash = DomainNameHashValue(&q->qname); // and namehash mDNS_StartQuery_internal(m, q); // Start new query if (sock) // Transplant saved socket, if appropriate { if (q->DuplicateOf) mDNSPlatformUDPClose(sock); else { q->LocalSocket = sock; q->TargetQID = id; } } return; // All done for now; wait until we get the next answer } } #endif // USE_LIBIDN // Only deliver negative answers if client has explicitly requested them except when we are forcing a negative response // for the purpose of retrying search domains/timeout OR the question is suppressed if (rr->resrec.RecordType == kDNSRecordTypePacketNegative || (q->qtype != kDNSType_NSEC && RRAssertsNonexistence(&rr->resrec, q->qtype))) if (!AddRecord || (AddRecord != QC_suppressed && AddRecord != QC_forceresponse && !q->ReturnIntermed)) return; // For CNAME results to non-CNAME questions, only inform the client if they explicitly requested that if (q->QuestionCallback && !q->NoAnswer && (!followcname || q->ReturnIntermed)) { mDNS_DropLockBeforeCallback(); // Allow client (and us) to legally make mDNS API calls if (q->qtype != kDNSType_NSEC && RRAssertsNonexistence(&rr->resrec, q->qtype)) { if (mDNSOpaque16IsZero(q->TargetQID)) { CacheRecord neg; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSPlatformMemZero(&neg, sizeof(neg)); MakeNegativeCacheRecord(m, &neg, &q->qname, q->qnamehash, q->qtype, q->qclass, 1, rr->resrec.InterfaceID, q->dnsservice); #else MakeNegativeCacheRecord(m, &neg, &q->qname, q->qnamehash, q->qtype, q->qclass, 1, rr->resrec.InterfaceID, q->qDNSServer); #endif q->QuestionCallback(m, q, &neg.resrec, AddRecord); } } else { #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) if (DNS64ShouldAnswerQuestion(q, &rr->resrec)) { DNS64AnswerCurrentQuestion(m, &rr->resrec, AddRecord); } else #endif { #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) get_denial_records_from_negative_cache_to_dnssec_context(q->DNSSECStatus.enable_dnssec, q->DNSSECStatus.context, rr); #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) q->QuestionCallback(m, q, &rr->resrec, AddRecord); } } mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again } // Note: Proceed with caution after this point because client callback function // invoked above is allowed to do anything, such as starting/stopping queries // (including this one itself, or the next or previous query in the linked list), // registering/deregistering records, starting/stopping NAT traversals, etc. if (m->CurrentQuestion == q) { // If we get a CNAME back while we are validating the response (i.e., CNAME for DS, DNSKEY, RRSIG), // don't follow them. If it is a ValidationRequired question, wait for the CNAME to be validated // first before following it if (followcname) AnswerQuestionByFollowingCNAME(m, q, &rr->resrec); // If we are returning expired RRs, then remember the first expired qname we we can start the query again if (rr->resrec.mortality == Mortality_Ghost && !q->firstExpiredQname.c[0] && (q->allowExpired == AllowExpired_AllowExpiredAnswers) && rr->resrec.RecordType != kDNSRecordTypePacketNegative) { debugf("AnswerCurrentQuestionWithResourceRecord: Keeping track of domain for expired RR %s for question %p", CRDisplayString(m,rr), q); // Note: question->qname is already changed at this point if following a CNAME AssignDomainName(&q->firstExpiredQname, rr->resrec.name); // Update firstExpiredQname } } } mDNSlocal void CacheRecordDeferredAdd(mDNS *const m, CacheRecord *cr) { cr->DelayDelivery = 0; if (m->CurrentQuestion) LogMsg("CacheRecordDeferredAdd ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) { DNSQuestion *q = m->CurrentQuestion; if (CacheRecordAnswersQuestion(cr, q)) AnswerCurrentQuestionWithResourceRecord(m, cr, QC_add); if (m->CurrentQuestion == q) // If m->CurrentQuestion was not auto-advanced, do it ourselves now m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } mDNSlocal mDNSs32 CheckForSoonToExpireRecords(mDNS *const m, const domainname *const name, const mDNSu32 namehash) { const mDNSs32 threshold = m->timenow + mDNSPlatformOneSecond; // See if there are any records expiring within one second const mDNSs32 start = m->timenow - 0x10000000; mDNSs32 delay = start; CacheGroup *cg = CacheGroupForName(m, namehash, name); const CacheRecord *rr; for (rr = cg ? cg->members : mDNSNULL; rr; rr=rr->next) { if (threshold - RRExpireTime(rr) >= 0) // If we have records about to expire within a second { if (delay - RRExpireTime(rr) < 0) // then delay until after they've been deleted delay = RRExpireTime(rr); } } if (delay - start > 0) return(NonZeroTime(delay)); else return(0); } // CacheRecordAdd is only called from CreateNewCacheEntry, *never* directly as a result of a client API call. // If new questions are created as a result of invoking client callbacks, they will be added to // the end of the question list, and m->NewQuestions will be set to indicate the first new question. // rr is a new CacheRecord just received into our cache // (kDNSRecordTypePacketAns/PacketAnsUnique/PacketAdd/PacketAddUnique). // Note: CacheRecordAdd calls AnswerCurrentQuestionWithResourceRecord which can call a user callback, // which may change the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSlocal void CacheRecordAdd(mDNS *const m, CacheRecord *cr) { DNSQuestion *q; // We stop when we get to NewQuestions -- if we increment their CurrentAnswers/LargeAnswers/UniqueAnswers // counters here we'll end up double-incrementing them when we do it again in AnswerNewQuestion(). for (q = m->Questions; q && q != m->NewQuestions; q=q->next) { if (CacheRecordAnswersQuestion(cr, q)) { mDNSIPPort zp = zeroIPPort; // If this question is one that's actively sending queries, and it's received ten answers within one // second of sending the last query packet, then that indicates some radical network topology change, // so reset its exponential backoff back to the start. We must be at least at the eight-second interval // to do this. If we're at the four-second interval, or less, there's not much benefit accelerating // because we will anyway send another query within a few seconds. The first reset query is sent out // randomized over the next four seconds to reduce possible synchronization between machines. if (q->LastAnswerPktNum != m->PktNum) { q->LastAnswerPktNum = m->PktNum; if (mDNSOpaque16IsZero(q->TargetQID) && ActiveQuestion(q) && ++q->RecentAnswerPkts >= 10 && q->ThisQInterval > InitialQuestionInterval * QuestionIntervalStep3 && m->timenow - q->LastQTxTime < mDNSPlatformOneSecond) { LogMsg("CacheRecordAdd: %##s (%s) got immediate answer burst (%d); restarting exponential backoff sequence (%d)", q->qname.c, DNSTypeName(q->qtype), q->RecentAnswerPkts, q->ThisQInterval); q->LastQTime = m->timenow - InitialQuestionInterval + (mDNSs32)mDNSRandom((mDNSu32)mDNSPlatformOneSecond*4); q->ThisQInterval = InitialQuestionInterval; SetNextQueryTime(m,q); } } verbosedebugf("CacheRecordAdd %p %##s (%s) %lu %#a:%d question %p", cr, cr->resrec.name->c, DNSTypeName(cr->resrec.rrtype), cr->resrec.rroriginalttl, cr->resrec.rDNSServer ? &cr->resrec.rDNSServer->addr : mDNSNULL, mDNSVal16(cr->resrec.rDNSServer ? cr->resrec.rDNSServer->port : zeroIPPort), q); q->CurrentAnswers++; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) q->unansweredQueries = 0; #endif if (cr->resrec.rdlength > SmallRecordLimit) q->LargeAnswers++; if (cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) q->UniqueAnswers++; if (q->CurrentAnswers > 4000) { static int msgcount = 0; if (msgcount++ < 10) LogMsg("CacheRecordAdd: %##s (%s) has %d answers; shedding records to resist DOS attack", q->qname.c, DNSTypeName(q->qtype), q->CurrentAnswers); cr->resrec.rroriginalttl = 0; cr->UnansweredQueries = MaxUnansweredQueries; } } } if (!cr->DelayDelivery) { if (m->CurrentQuestion) LogMsg("CacheRecordAdd ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) { q = m->CurrentQuestion; if (CacheRecordAnswersQuestion(cr, q)) AnswerCurrentQuestionWithResourceRecord(m, cr, QC_add); if (m->CurrentQuestion == q) // If m->CurrentQuestion was not auto-advanced, do it ourselves now m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } SetNextCacheCheckTimeForRecord(m, cr); } // NoCacheAnswer is only called from mDNSCoreReceiveResponse, *never* directly as a result of a client API call. // If new questions are created as a result of invoking client callbacks, they will be added to // the end of the question list, and m->NewQuestions will be set to indicate the first new question. // rr is a new CacheRecord just received from the wire (kDNSRecordTypePacketAns/AnsUnique/Add/AddUnique) // but we don't have any place to cache it. We'll deliver question 'add' events now, but we won't have any // way to deliver 'remove' events in future, nor will we be able to include this in known-answer lists, // so we immediately bump ThisQInterval up to MaxQuestionInterval to avoid pounding the network. // Note: NoCacheAnswer calls AnswerCurrentQuestionWithResourceRecord which can call a user callback, // which may change the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSlocal void NoCacheAnswer(mDNS *const m, CacheRecord *cr) { LogMsg("No cache space: Delivering non-cached result for %##s", m->rec.r.resrec.name->c); if (m->CurrentQuestion) LogMsg("NoCacheAnswer ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; // We do this for *all* questions, not stopping when we get to m->NewQuestions, // since we're not caching the record and we'll get no opportunity to do this later while (m->CurrentQuestion) { DNSQuestion *q = m->CurrentQuestion; if (CacheRecordAnswersQuestion(cr, q)) AnswerCurrentQuestionWithResourceRecord(m, cr, QC_addnocache); // QC_addnocache means "don't expect remove events for this" if (m->CurrentQuestion == q) // If m->CurrentQuestion was not auto-advanced, do it ourselves now m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } // CacheRecordRmv is only called from CheckCacheExpiration, which is called from mDNS_Execute. // Note that CacheRecordRmv is *only* called for records that are referenced by at least one active question. // If new questions are created as a result of invoking client callbacks, they will be added to // the end of the question list, and m->NewQuestions will be set to indicate the first new question. // cr is an existing cache CacheRecord that just expired and is being deleted // (kDNSRecordTypePacketAns/PacketAnsUnique/PacketAdd/PacketAddUnique). // Note: CacheRecordRmv calls AnswerCurrentQuestionWithResourceRecord which can call a user callback, // which may change the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSlocal void CacheRecordRmv(mDNS *const m, CacheRecord *cr) { if (m->CurrentQuestion) LogMsg("CacheRecordRmv ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; // We stop when we get to NewQuestions -- for new questions their CurrentAnswers/LargeAnswers/UniqueAnswers counters // will all still be zero because we haven't yet gone through the cache counting how many answers we have for them. while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) { DNSQuestion *q = m->CurrentQuestion; // When a question enters suppressed state, we generate RMV events and generate a negative // response. A cache may be present that answers this question e.g., cache entry generated // before the question became suppressed. We need to skip the suppressed questions here as // the RMV event has already been generated. if (!q->Suppressed && CacheRecordAnswersQuestion(cr, q) && (q->allowExpired == AllowExpired_None || cr->resrec.mortality == Mortality_Mortal)) { verbosedebugf("CacheRecordRmv %p %s", cr, CRDisplayString(m, cr)); q->FlappingInterface1 = mDNSNULL; q->FlappingInterface2 = mDNSNULL; if (q->CurrentAnswers == 0) { #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) LogMsg("CacheRecordRmv ERROR!!: How can CurrentAnswers already be zero for %p %##s (%s) DNSServer %#a:%d", q, q->qname.c, DNSTypeName(q->qtype), q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort)); #endif } else { q->CurrentAnswers--; if (cr->resrec.rdlength > SmallRecordLimit) q->LargeAnswers--; if (cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) q->UniqueAnswers--; } // If we have dropped below the answer threshold for this mDNS question, // restart the queries at InitialQuestionInterval. if (mDNSOpaque16IsZero(q->TargetQID) && (q->BrowseThreshold > 0) && (q->CurrentAnswers < q->BrowseThreshold)) { q->ThisQInterval = InitialQuestionInterval; q->LastQTime = m->timenow - q->ThisQInterval; SetNextQueryTime(m,q); LogInfo("CacheRecordRmv: (%s) %##s dropped below threshold of %d answers", DNSTypeName(q->qtype), q->qname.c, q->BrowseThreshold); } if (cr->resrec.rdata->MaxRDLength) // Never generate "remove" events for negative results { if ((q->CurrentAnswers == 0) && mDNSOpaque16IsZero(q->TargetQID)) { LogInfo("CacheRecordRmv: Last answer for %##s (%s) expired from cache; will reconfirm antecedents", q->qname.c, DNSTypeName(q->qtype)); ReconfirmAntecedents(m, &q->qname, q->qnamehash, cr->resrec.InterfaceID, 0); } AnswerCurrentQuestionWithResourceRecord(m, cr, QC_rmv); } } if (m->CurrentQuestion == q) // If m->CurrentQuestion was not auto-advanced, do it ourselves now m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } mDNSlocal void ReleaseCacheEntity(mDNS *const m, CacheEntity *e) { #if MDNS_MALLOC_DEBUGGING >= 1 unsigned int i; for (i=0; inext = m->rrcache_free; m->rrcache_free = e; m->rrcache_totalused--; } mDNSlocal void ReleaseCacheGroup(mDNS *const m, CacheGroup **cp) { CacheEntity *e = (CacheEntity *)(*cp); //LogMsg("ReleaseCacheGroup: Releasing CacheGroup for %p, %##s", (*cp)->name->c, (*cp)->name->c); if ((*cp)->rrcache_tail != &(*cp)->members) LogMsg("ERROR: (*cp)->members == mDNSNULL but (*cp)->rrcache_tail != &(*cp)->members)"); //if ((*cp)->name != (domainname*)((*cp)->namestorage)) // LogMsg("ReleaseCacheGroup: %##s, %p %p", (*cp)->name->c, (*cp)->name, (domainname*)((*cp)->namestorage)); if ((*cp)->name != (domainname*)((*cp)->namestorage)) mDNSPlatformMemFree((*cp)->name); (*cp)->name = mDNSNULL; *cp = (*cp)->next; // Cut record from list ReleaseCacheEntity(m, e); } mDNSlocal void ReleaseAdditionalCacheRecords(mDNS *const m, CacheRecord **rp) { while (*rp) { CacheRecord *rr = *rp; *rp = (*rp)->next; // Cut record from list if (rr->resrec.rdata && rr->resrec.rdata != (RData*)&rr->smallrdatastorage) { mDNSPlatformMemFree(rr->resrec.rdata); rr->resrec.rdata = mDNSNULL; } // NSEC or SOA records that are not added to the CacheGroup do not share the name // of the CacheGroup. if (rr->resrec.name) { debugf("ReleaseAdditionalCacheRecords: freeing cached record %##s (%s)", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); mDNSPlatformMemFree((void *)rr->resrec.name); rr->resrec.name = mDNSNULL; } // Don't count the NSEC3 records used by anonymous browse/reg if (!rr->resrec.InterfaceID) { m->rrcache_totalused_unicast -= rr->resrec.rdlength; } ReleaseCacheEntity(m, (CacheEntity *)rr); } } mDNSexport void ReleaseCacheRecord(mDNS *const m, CacheRecord *r) { CacheGroup *cg; //LogMsg("ReleaseCacheRecord: Releasing %s", CRDisplayString(m, r)); if (r->resrec.rdata && r->resrec.rdata != (RData*)&r->smallrdatastorage) mDNSPlatformMemFree(r->resrec.rdata); r->resrec.rdata = mDNSNULL; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_forget(&r->resrec.dnsservice); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) release_denial_records_in_cache_record(r); #endif cg = CacheGroupForRecord(m, &r->resrec); if (!cg) { // It is okay to have this printed for NSEC/NSEC3s LogInfo("ReleaseCacheRecord: ERROR!! cg NULL for %##s (%s)", r->resrec.name->c, DNSTypeName(r->resrec.rrtype)); } // When NSEC records are not added to the cache, it is usually cached at the "nsec" list // of the CacheRecord. But sometimes they may be freed without adding to the "nsec" list // (which is handled below) and in that case it should be freed here. if (r->resrec.name && cg && r->resrec.name != cg->name) { debugf("ReleaseCacheRecord: freeing %##s (%s)", r->resrec.name->c, DNSTypeName(r->resrec.rrtype)); mDNSPlatformMemFree((void *)r->resrec.name); } r->resrec.name = mDNSNULL; if (!r->resrec.InterfaceID) { m->rrcache_totalused_unicast -= r->resrec.rdlength; } ReleaseAdditionalCacheRecords(m, &r->soa); ReleaseCacheEntity(m, (CacheEntity *)r); } // Note: We want to be careful that we deliver all the CacheRecordRmv calls before delivering // CacheRecordDeferredAdd calls. The in-order nature of the cache lists ensures that all // callbacks for old records are delivered before callbacks for newer records. mDNSlocal void CheckCacheExpiration(mDNS *const m, const mDNSu32 slot, CacheGroup *const cg) { CacheRecord **rp = &cg->members; if (m->lock_rrcache) { LogMsg("CheckCacheExpiration ERROR! Cache already locked!"); return; } m->lock_rrcache = 1; while (*rp) { CacheRecord *const rr = *rp; mDNSBool recordReleased = mDNSfalse; mDNSs32 event = RRExpireTime(rr); if (m->timenow - event >= 0) // If expired, delete it { if (rr->CRActiveQuestion) // If this record has one or more active questions, tell them it's going away { DNSQuestion *q = rr->CRActiveQuestion; verbosedebugf("CheckCacheExpiration: Removing%7d %7d %p %s", m->timenow - rr->TimeRcvd, rr->resrec.rroriginalttl, rr->CRActiveQuestion, CRDisplayString(m, rr)); // When a cache record is about to expire, we expect to do four queries at 80-82%, 85-87%, 90-92% and // then 95-97% of the TTL. If the DNS server does not respond, then we will remove the cache entry // before we pick a new DNS server. As the question interval is set to MaxQuestionInterval, we may // not send out a query anytime soon. Hence, we need to reset the question interval. If this is // a normal deferred ADD case, then AnswerCurrentQuestionWithResourceRecord will reset it to // MaxQuestionInterval. If we have inactive questions referring to negative cache entries, // don't ressurect them as they will deliver duplicate "No such Record" ADD events if (((mDNSOpaque16IsZero(q->TargetQID) && (rr->resrec.RecordType & kDNSRecordTypePacketUniqueMask)) || (!mDNSOpaque16IsZero(q->TargetQID) && !q->LongLived)) && ActiveQuestion(q)) { q->ThisQInterval = InitialQuestionInterval; q->LastQTime = m->timenow - q->ThisQInterval; SetNextQueryTime(m, q); } CacheRecordRmv(m, rr); m->rrcache_active--; } event += MAX_GHOST_TIME; // Adjust so we can check for a ghost expiration if (rr->resrec.mortality == Mortality_Mortal || // Normal expired mortal record that needs released rr->resrec.rroriginalttl == 0 || // Non-mortal record that is set to be purged (rr->resrec.mortality == Mortality_Ghost && m->timenow - event >= 0)) // A ghost record that expired more than MAX_GHOST_TIME ago { // Release as normal *rp = rr->next; // Cut it from the list before ReleaseCacheRecord verbosedebugf("CheckCacheExpiration: Deleting (%s)%7d %7d %p %s", MortalityDisplayString(rr->resrec.mortality), m->timenow - rr->TimeRcvd, rr->resrec.rroriginalttl, rr->CRActiveQuestion, CRDisplayString(m, rr)); ReleaseCacheRecord(m, rr); recordReleased = mDNStrue; } else // An immortal record needs to become a ghost when it expires { // Don't release this entry if (rr->resrec.mortality == Mortality_Immortal) { rr->resrec.mortality = Mortality_Ghost; // Expired immortal records become ghosts verbosedebugf("CheckCacheExpiration: NOT Deleting (%s)%7d %7d %p %s", MortalityDisplayString(rr->resrec.mortality), m->timenow - rr->TimeRcvd, rr->resrec.rroriginalttl, rr->CRActiveQuestion, CRDisplayString(m, rr)); } } } else // else, not expired; see if we need to query { // If waiting to delay delivery, do nothing until then if (rr->DelayDelivery && rr->DelayDelivery - m->timenow > 0) event = rr->DelayDelivery; else { if (rr->DelayDelivery) CacheRecordDeferredAdd(m, rr); if (rr->CRActiveQuestion && rr->UnansweredQueries < MaxUnansweredQueries) { if (m->timenow - rr->NextRequiredQuery < 0) // If not yet time for next query event = NextCacheCheckEvent(rr); // then just record when we want the next query else // else trigger our question to go out now { // Set NextScheduledQuery to timenow so that SendQueries() will run. // SendQueries() will see that we have records close to expiration, and send FEQs for them. m->NextScheduledQuery = m->timenow; // After sending the query we'll increment UnansweredQueries and call SetNextCacheCheckTimeForRecord(), // which will correctly update m->NextCacheCheck for us. event = m->timenow + FutureTime; } } } } if (!recordReleased) // Schedule if we did not release the record { verbosedebugf("CheckCacheExpiration:%6d %5d %s", (event - m->timenow) / mDNSPlatformOneSecond, CacheCheckGracePeriod(rr), CRDisplayString(m, rr)); if (m->rrcache_nextcheck[slot] - event > 0) m->rrcache_nextcheck[slot] = event; rp = &rr->next; } } if (cg->rrcache_tail != rp) verbosedebugf("CheckCacheExpiration: Updating CacheGroup tail from %p to %p", cg->rrcache_tail, rp); cg->rrcache_tail = rp; m->lock_rrcache = 0; } // "LORecord" includes both LocalOnly and P2P record. This function assumes m->CurrentQuestion is pointing to "q". // // If "CheckOnly" is set to "true", the question won't be answered but just check to see if there is an answer and // returns true if there is an answer. // // If "CheckOnly" is set to "false", the question will be answered if there is a LocalOnly/P2P record and // returns true to indicate the same. mDNSlocal mDNSBool AnswerQuestionWithLORecord(mDNS *const m, DNSQuestion *q, mDNSBool checkOnly) { AuthRecord *lr; AuthGroup *ag; if (m->CurrentRecord) LogMsg("AnswerQuestionWithLORecord ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); ag = AuthGroupForName(&m->rrauth, q->qnamehash, &q->qname); if (ag) { m->CurrentRecord = ag->members; while (m->CurrentRecord && m->CurrentRecord != ag->NewLocalOnlyRecords) { AuthRecord *rr = m->CurrentRecord; m->CurrentRecord = rr->next; // // If the question is mDNSInterface_LocalOnly, all records local to the machine should be used // to answer the query. This is handled in AnswerNewLocalOnlyQuestion. // // We handle mDNSInterface_Any and scoped questions here. See LocalOnlyRecordAnswersQuestion for more // details on how we handle this case. For P2P we just handle "Interface_Any" questions. For LocalOnly // we handle both mDNSInterface_Any and scoped questions. if (rr->ARType == AuthRecordLocalOnly || (rr->ARType == AuthRecordP2P && (q->InterfaceID == mDNSInterface_Any || q->InterfaceID == mDNSInterface_BLE))) if (LocalOnlyRecordAnswersQuestion(rr, q)) { if (checkOnly) { LogInfo("AnswerQuestionWithLORecord: question %##s (%s) answered by %s", q->qname.c, DNSTypeName(q->qtype), ARDisplayString(m, rr)); m->CurrentRecord = mDNSNULL; return mDNStrue; } AnswerLocalQuestionWithLocalAuthRecord(m, rr, QC_add); if (m->CurrentQuestion != q) break; // If callback deleted q, then we're finished here } } } m->CurrentRecord = mDNSNULL; if (m->CurrentQuestion != q) { LogInfo("AnswerQuestionWithLORecord: Question deleted while while answering LocalOnly record answers"); return mDNStrue; } if (q->LOAddressAnswers) { LogInfo("AnswerQuestionWithLORecord: Question %p %##s (%s) answered using local auth records LOAddressAnswers %d", q, q->qname.c, DNSTypeName(q->qtype), q->LOAddressAnswers); return mDNStrue; } // Before we go check the cache and ship this query on the wire, we have to be sure that there are // no local records that could possibly answer this question. As we did not check the NewLocalRecords, we // need to just peek at them to see whether it will answer this question. If it would answer, pretend // that we answered. AnswerAllLocalQuestionsWithLocalAuthRecord will answer shortly. This happens normally // when we add new /etc/hosts entries and restart the question. It is a new question and also a new record. if (ag) { lr = ag->NewLocalOnlyRecords; while (lr) { if (UniqueLocalOnlyRecord(lr) && LocalOnlyRecordAnswersQuestion(lr, q)) { LogInfo("AnswerQuestionWithLORecord: Question %p %##s (%s) will be answered using new local auth records " " LOAddressAnswers %d", q, q->qname.c, DNSTypeName(q->qtype), q->LOAddressAnswers); return mDNStrue; } lr = lr->next; } } return mDNSfalse; } // Today, we suppress questions (not send them on the wire) for several reasons e.g., // AAAA query is suppressed because no IPv6 capability or PID is not allowed to make // DNS requests. mDNSlocal void AnswerSuppressedQuestion(mDNS *const m, DNSQuestion *q) { // If the client did not set the kDNSServiceFlagsReturnIntermediates flag, then don't generate a negative response, // just deactivate the DNSQuestion. if (q->ReturnIntermed) { GenerateNegativeResponse(m, mDNSInterface_Any, QC_suppressed); } else { q->ThisQInterval = 0; } } mDNSlocal void AnswerNewQuestion(mDNS *const m) { mDNSBool ShouldQueryImmediately = mDNStrue; DNSQuestion *const q = m->NewQuestions; // Grab the question we're going to answer #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) if (!mDNSOpaque16IsZero(q->TargetQID)) DNS64HandleNewQuestion(m, q); #endif CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); verbosedebugf("AnswerNewQuestion: Answering %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); if (cg) CheckCacheExpiration(m, HashSlotFromNameHash(q->qnamehash), cg); if (m->NewQuestions != q) { LogInfo("AnswerNewQuestion: Question deleted while doing CheckCacheExpiration"); goto exit; } m->NewQuestions = q->next; // Advance NewQuestions to the next *after* calling CheckCacheExpiration, because if we advance it first // then CheckCacheExpiration may give this question add/remove callbacks, and it's not yet ready for that. // // Also, CheckCacheExpiration() calls CacheRecordDeferredAdd() and CacheRecordRmv(), which invoke // client callbacks, which may delete their own or any other question. Our mechanism for detecting // whether our current m->NewQuestions question got deleted by one of these callbacks is to store the // value of m->NewQuestions in 'q' before calling CheckCacheExpiration(), and then verify afterwards // that they're still the same. If m->NewQuestions has changed (because mDNS_StopQuery_internal // advanced it), that means the question was deleted, so we no longer need to worry about answering // it (and indeed 'q' is now a dangling pointer, so dereferencing it at all would be bad, and the // values we computed for slot and cg are now stale and relate to a question that no longer exists). // // We can't use the usual m->CurrentQuestion mechanism for this because CacheRecordDeferredAdd() and // CacheRecordRmv() both use that themselves when walking the list of (non-new) questions generating callbacks. // Fortunately mDNS_StopQuery_internal auto-advances both m->CurrentQuestion *AND* m->NewQuestions when // deleting a question, so luckily we have an easy alternative way of detecting if our question got deleted. if (m->lock_rrcache) LogMsg("AnswerNewQuestion ERROR! Cache already locked!"); // This should be safe, because calling the client's question callback may cause the // question list to be modified, but should not ever cause the rrcache list to be modified. // If the client's question callback deletes the question, then m->CurrentQuestion will // be advanced, and we'll exit out of the loop m->lock_rrcache = 1; if (m->CurrentQuestion) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d->Q%d] AnswerNewQuestion ERROR m->CurrentQuestion already set: " PRI_DM_NAME " (" PUB_S ")", m->CurrentQuestion->request_id, mDNSVal16(m->CurrentQuestion->TargetQID), DM_NAME_PARAM(&m->CurrentQuestion->qname), DNSTypeName(m->CurrentQuestion->qtype)); } m->CurrentQuestion = q; // Indicate which question we're answering, so we'll know if it gets deleted if (q->NoAnswer == NoAnswer_Fail) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d->Q%d] AnswerNewQuestion: NoAnswer_Fail " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) MakeNegativeCacheRecord(m, &m->rec.r, &q->qname, q->qnamehash, q->qtype, q->qclass, 60, mDNSInterface_Any, q->dnsservice); #else MakeNegativeCacheRecord(m, &m->rec.r, &q->qname, q->qnamehash, q->qtype, q->qclass, 60, mDNSInterface_Any, q->qDNSServer); #endif q->NoAnswer = NoAnswer_Normal; // Temporarily turn off answer suppression AnswerCurrentQuestionWithResourceRecord(m, &m->rec.r, QC_addnocache); // Don't touch the question if it has been stopped already if (m->CurrentQuestion == q) q->NoAnswer = NoAnswer_Fail; // Restore NoAnswer state m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } if (m->CurrentQuestion != q) { LogInfo("AnswerNewQuestion: Question deleted while generating NoAnswer_Fail response"); goto exit; } // See if we want to tell it about LocalOnly/P2P records. If we answered them using LocalOnly // or P2P record, then we are done. if (AnswerQuestionWithLORecord(m, q, mDNSfalse)) goto exit; // If it is a question trying to validate some response, it already checked the cache for a response. If it still // reissues a question it means it could not find the RRSIGs. So, we need to bypass the cache check and send // the question out. if (q->Suppressed) { AnswerSuppressedQuestion(m, q); } else { CacheRecord *cr; for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) if (SameNameCacheRecordAnswersQuestion(cr, q)) { // SecsSinceRcvd is whole number of elapsed seconds, rounded down mDNSu32 SecsSinceRcvd = ((mDNSu32)(m->timenow - cr->TimeRcvd)) / mDNSPlatformOneSecond; mDNSBool IsExpired = (cr->resrec.rroriginalttl <= SecsSinceRcvd); if (IsExpired && q->allowExpired != AllowExpired_AllowExpiredAnswers) continue; // Go to next one in loop // If this record set is marked unique, then that means we can reasonably assume we have the whole set // -- we don't need to rush out on the network and query immediately to see if there are more answers out there if ((cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) || (q->ExpectUnique)) ShouldQueryImmediately = mDNSfalse; q->CurrentAnswers++; if (cr->resrec.rdlength > SmallRecordLimit) q->LargeAnswers++; if (cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) q->UniqueAnswers++; #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if (q->metrics.expiredAnswerState == ExpiredAnswer_Allowed) q->metrics.expiredAnswerState = IsExpired ? ExpiredAnswer_AnsweredWithExpired : ExpiredAnswer_AnsweredWithCache; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) cr->LastCachedAnswerTime = m->timenow; dnssd_analytics_update_cache_request(mDNSOpaque16IsZero(q->TargetQID) ? CacheRequestType_multicast : CacheRequestType_unicast, CacheState_hit); #endif AnswerCurrentQuestionWithResourceRecord(m, cr, QC_add); if (m->CurrentQuestion != q) break; // If callback deleted q, then we're finished here } else if (mDNSOpaque16IsZero(q->TargetQID) && RRTypeIsAddressType(cr->resrec.rrtype) && RRTypeIsAddressType(q->qtype)) ShouldQueryImmediately = mDNSfalse; } // We don't use LogInfo for this "Question deleted" message because it happens so routinely that // it's not remotely remarkable, and therefore unlikely to be of much help tracking down bugs. if (m->CurrentQuestion != q) { debugf("AnswerNewQuestion: Question deleted while giving cache answers"); goto exit; } #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) dnssd_analytics_update_cache_request(mDNSOpaque16IsZero(q->TargetQID) ? CacheRequestType_multicast : CacheRequestType_unicast, CacheState_miss); #endif q->InitialCacheMiss = mDNStrue; // Initial cache check is done, so mark as a miss from now on if (q->allowExpired == AllowExpired_AllowExpiredAnswers) { q->allowExpired = AllowExpired_MakeAnswersImmortal; // After looking through the cache for an answer, demote to make immortal if (q->firstExpiredQname.c[0]) // If an original query name was saved on an expired answer, start it over in case it is updated { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d->Q%d] AnswerNewQuestion: Restarting original question %p firstExpiredQname " PRI_DM_NAME " for allowExpiredAnswers question", q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->firstExpiredQname)); mDNS_StopQuery_internal(m, q); // Stop old query #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!SameDomainName(&q->qname, &q->firstExpiredQname)) { Querier_PrepareQuestionForUnwindRestart(q); } #endif AssignDomainName(&q->qname, &q->firstExpiredQname); // Update qname q->qnamehash = DomainNameHashValue(&q->qname); // and namehash mDNS_StartQuery_internal(m, q); // start new query q->CNAMEReferrals = 0; // Reset referral count q->firstExpiredQname.c[0] = 0; // Erase the domain name } } // Note: When a query gets suppressed or retried with search domains, we de-activate the question. // Hence we don't execute the following block of code for those cases. if (ShouldQueryImmediately && ActiveQuestion(q)) { debugf("[R%d->Q%d] AnswerNewQuestion: ShouldQueryImmediately %##s (%s)", q->request_id, mDNSVal16(q->TargetQID), q->qname.c, DNSTypeName(q->qtype)); q->ThisQInterval = InitialQuestionInterval; q->LastQTime = m->timenow - q->ThisQInterval; if (mDNSOpaque16IsZero(q->TargetQID)) // For mDNS, spread packets to avoid a burst of simultaneous queries { // Compute random delay in the range 1-6 seconds, then divide by 50 to get 20-120ms if (!m->RandomQueryDelay) m->RandomQueryDelay = (mDNSPlatformOneSecond + mDNSRandom(mDNSPlatformOneSecond*5) - 1) / 50 + 1; q->LastQTime += m->RandomQueryDelay; } } // IN ALL CASES make sure that m->NextScheduledQuery is set appropriately. // In cases where m->NewQuestions->DelayAnswering is set, we may have delayed generating our // answers for this question until *after* its scheduled transmission time, in which case // m->NextScheduledQuery may now be set to 'never', and in that case -- even though we're *not* doing // ShouldQueryImmediately -- we still need to make sure we set m->NextScheduledQuery correctly. SetNextQueryTime(m,q); exit: m->CurrentQuestion = mDNSNULL; m->lock_rrcache = 0; } // When a NewLocalOnlyQuestion is created, AnswerNewLocalOnlyQuestion runs though our ResourceRecords delivering any // appropriate answers, stopping if it reaches a NewLocalOnlyRecord -- these will be handled by AnswerAllLocalQuestionsWithLocalAuthRecord mDNSlocal void AnswerNewLocalOnlyQuestion(mDNS *const m) { AuthGroup *ag; DNSQuestion *q = m->NewLocalOnlyQuestions; // Grab the question we're going to answer mDNSBool retEv = mDNSfalse; m->NewLocalOnlyQuestions = q->next; // Advance NewLocalOnlyQuestions to the next (if any) debugf("AnswerNewLocalOnlyQuestion: Answering %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); if (m->CurrentQuestion) LogMsg("AnswerNewLocalOnlyQuestion ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = q; // Indicate which question we're answering, so we'll know if it gets deleted if (m->CurrentRecord) LogMsg("AnswerNewLocalOnlyQuestion ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); // 1. First walk the LocalOnly records answering the LocalOnly question // 2. As LocalOnly questions should also be answered by any other Auth records local to the machine, // walk the ResourceRecords list delivering the answers ag = AuthGroupForName(&m->rrauth, q->qnamehash, &q->qname); if (ag) { m->CurrentRecord = ag->members; while (m->CurrentRecord && m->CurrentRecord != ag->NewLocalOnlyRecords) { AuthRecord *rr = m->CurrentRecord; m->CurrentRecord = rr->next; if (LocalOnlyRecordAnswersQuestion(rr, q)) { retEv = mDNStrue; AnswerLocalQuestionWithLocalAuthRecord(m, rr, QC_add); if (m->CurrentQuestion != q) break; // If callback deleted q, then we're finished here } } } if (m->CurrentQuestion == q) { m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord && m->CurrentRecord != m->NewLocalRecords) { AuthRecord *ar = m->CurrentRecord; m->CurrentRecord = ar->next; if (AuthRecordAnswersQuestion(ar, q)) { retEv = mDNStrue; AnswerLocalQuestionWithLocalAuthRecord(m, ar, QC_add); if (m->CurrentQuestion != q) break; // If callback deleted q, then we're finished here } } } // The local host is the authoritative source for LocalOnly questions // so if no records exist and client requested intermediates, then generate a negative response if (!retEv && (m->CurrentQuestion == q) && q->ReturnIntermed) GenerateNegativeResponse(m, mDNSInterface_LocalOnly, QC_forceresponse); m->CurrentQuestion = mDNSNULL; m->CurrentRecord = mDNSNULL; } mDNSlocal CacheEntity *GetCacheEntity(mDNS *const m, const CacheGroup *const PreserveCG) { CacheEntity *e = mDNSNULL; if (m->lock_rrcache) { LogMsg("GetFreeCacheRR ERROR! Cache already locked!"); return(mDNSNULL); } m->lock_rrcache = 1; // If we have no free records, ask the client layer to give us some more memory if (!m->rrcache_free && m->MainCallback) { if (m->rrcache_totalused != m->rrcache_size) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "GetFreeCacheRR: count mismatch: m->rrcache_totalused %u != m->rrcache_size %u", m->rrcache_totalused, m->rrcache_size); } // We don't want to be vulnerable to a malicious attacker flooding us with an infinite // number of bogus records so that we keep growing our cache until the machine runs out of memory. // To guard against this, if our cache grows above 512kB (approx 3168 records at 164 bytes each), // and we're actively using less than 1/32 of that cache, then we purge all the unused records // and recycle them, instead of allocating more memory. if (m->rrcache_size > 5000 && m->rrcache_size / 32 > m->rrcache_active) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "Possible denial-of-service attack in progress: m->rrcache_size %u; m->rrcache_active %u", m->rrcache_size, m->rrcache_active); } else { mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback m->MainCallback(m, mStatus_GrowCache); mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again } } // If we still have no free records, recycle all the records we can. // Enumerating the entire cache is moderately expensive, so when we do it, we reclaim all the records we can in one pass. if (!m->rrcache_free) { mDNSu32 oldtotalused = m->rrcache_totalused; mDNSu32 slot; for (slot = 0; slot < CACHE_HASH_SLOTS; slot++) { CacheGroup **cp = &m->rrcache_hash[slot]; while (*cp) { CacheRecord **rp = &(*cp)->members; while (*rp) { // Records that answer still-active questions are not candidates for recycling // Records that are currently linked into the CacheFlushRecords list may not be recycled, or we'll crash if ((*rp)->CRActiveQuestion || (*rp)->NextInCFList) rp=&(*rp)->next; else { CacheRecord *rr = *rp; *rp = (*rp)->next; // Cut record from list ReleaseCacheRecord(m, rr); } } if ((*cp)->rrcache_tail != rp) verbosedebugf("GetFreeCacheRR: Updating rrcache_tail[%lu] from %p to %p", slot, (*cp)->rrcache_tail, rp); (*cp)->rrcache_tail = rp; if ((*cp)->members || (*cp)==PreserveCG) cp=&(*cp)->next; else ReleaseCacheGroup(m, cp); } } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "GetCacheEntity recycled %d records to reduce cache from %d to %d", oldtotalused - m->rrcache_totalused, oldtotalused, m->rrcache_totalused); } if (m->rrcache_free) // If there are records in the free list, take one { e = m->rrcache_free; m->rrcache_free = e->next; if (++m->rrcache_totalused >= m->rrcache_report) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "RR Cache now using %u objects", m->rrcache_totalused); if (m->rrcache_report < 100) m->rrcache_report += 10; else if (m->rrcache_report < 1000) m->rrcache_report += 100; else m->rrcache_report += 1000; } mDNSPlatformMemZero(e, sizeof(*e)); } m->lock_rrcache = 0; return(e); } mDNSlocal CacheRecord *GetCacheRecord(mDNS *const m, CacheGroup *cg, mDNSu16 RDLength) { CacheRecord *r = (CacheRecord *)GetCacheEntity(m, cg); if (r) { r->resrec.rdata = (RData*)&r->smallrdatastorage; // By default, assume we're usually going to be using local storage if (RDLength > InlineCacheRDSize) // If RDLength is too big, allocate extra storage { r->resrec.rdata = (RData*) mDNSPlatformMemAllocateClear(sizeofRDataHeader + RDLength); if (r->resrec.rdata) r->resrec.rdata->MaxRDLength = r->resrec.rdlength = RDLength; else { ReleaseCacheEntity(m, (CacheEntity*)r); r = mDNSNULL; } } } return(r); } mDNSlocal CacheGroup *GetCacheGroup(mDNS *const m, const mDNSu32 slot, const ResourceRecord *const rr) { mDNSu16 namelen = DomainNameLength(rr->name); CacheGroup *cg = (CacheGroup*)GetCacheEntity(m, mDNSNULL); if (!cg) { LogMsg("GetCacheGroup: Failed to allocate memory for %##s", rr->name->c); return(mDNSNULL); } cg->next = m->rrcache_hash[slot]; cg->namehash = rr->namehash; cg->members = mDNSNULL; cg->rrcache_tail = &cg->members; if (namelen > sizeof(cg->namestorage)) cg->name = (domainname *) mDNSPlatformMemAllocate(namelen); else cg->name = (domainname*)cg->namestorage; if (!cg->name) { LogMsg("GetCacheGroup: Failed to allocate name storage for %##s", rr->name->c); ReleaseCacheEntity(m, (CacheEntity*)cg); return(mDNSNULL); } AssignDomainName(cg->name, rr->name); if (CacheGroupForRecord(m, rr)) LogMsg("GetCacheGroup: Already have CacheGroup for %##s", rr->name->c); m->rrcache_hash[slot] = cg; if (CacheGroupForRecord(m, rr) != cg) LogMsg("GetCacheGroup: Not finding CacheGroup for %##s", rr->name->c); return(cg); } mDNSexport void mDNS_PurgeCacheResourceRecord(mDNS *const m, CacheRecord *rr) { mDNS_CheckLock(m); // Make sure we mark this record as thoroughly expired -- we don't ever want to give // a positive answer using an expired record (e.g. from an interface that has gone away). // We don't want to clear CRActiveQuestion here, because that would leave the record subject to // summary deletion without giving the proper callback to any questions that are monitoring it. // By setting UnansweredQueries to MaxUnansweredQueries we ensure it won't trigger any further expiration queries. rr->TimeRcvd = m->timenow - mDNSPlatformOneSecond * 60; rr->UnansweredQueries = MaxUnansweredQueries; rr->resrec.rroriginalttl = 0; SetNextCacheCheckTimeForRecord(m, rr); } mDNSexport mDNSs32 mDNS_TimeNow(const mDNS *const m) { mDNSs32 time; mDNSPlatformLock(m); if (m->mDNS_busy) { LogMsg("mDNS_TimeNow called while holding mDNS lock. This is incorrect. Code protected by lock should just use m->timenow."); if (!m->timenow) LogMsg("mDNS_TimeNow: m->mDNS_busy is %ld but m->timenow not set", m->mDNS_busy); } if (m->timenow) time = m->timenow; else time = mDNS_TimeNow_NoLock(m); mDNSPlatformUnlock(m); return(time); } // To avoid pointless CPU thrash, we use SetSPSProxyListChanged(X) to record the last interface that // had its Sleep Proxy client list change, and defer to actual BPF reconfiguration to mDNS_Execute(). // (GetNextScheduledEvent() returns "now" when m->SPSProxyListChanged is set) #define SetSPSProxyListChanged(X) do { \ if (m->SPSProxyListChanged && m->SPSProxyListChanged != (X)) mDNSPlatformUpdateProxyList(m->SPSProxyListChanged); \ m->SPSProxyListChanged = (X); } while(0) // Called from mDNS_Execute() to expire stale proxy records mDNSlocal void CheckProxyRecords(mDNS *const m, AuthRecord *list) { m->CurrentRecord = list; while (m->CurrentRecord) { AuthRecord *rr = m->CurrentRecord; if (rr->resrec.RecordType != kDNSRecordTypeDeregistering && rr->WakeUp.HMAC.l[0]) { // If m->SPSSocket is NULL that means we're not acting as a sleep proxy any more, // so we need to cease proxying for *all* records we may have, expired or not. if (m->SPSSocket && m->timenow - rr->TimeExpire < 0) // If proxy record not expired yet, update m->NextScheduledSPS { if (m->NextScheduledSPS - rr->TimeExpire > 0) m->NextScheduledSPS = rr->TimeExpire; } else // else proxy record expired, so remove it { LogSPS("CheckProxyRecords: Removing %d H-MAC %.6a I-MAC %.6a %d %s", m->ProxyRecords, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, rr->WakeUp.seq, ARDisplayString(m, rr)); SetSPSProxyListChanged(rr->resrec.InterfaceID); mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); // Don't touch rr after this -- memory may have been free'd } } // Mustn't advance m->CurrentRecord until *after* mDNS_Deregister_internal, because // new records could have been added to the end of the list as a result of that call. if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } mDNSlocal void CheckRmvEventsForLocalRecords(mDNS *const m) { while (m->CurrentRecord) { AuthRecord *rr = m->CurrentRecord; if (rr->AnsweredLocalQ && rr->resrec.RecordType == kDNSRecordTypeDeregistering) { debugf("CheckRmvEventsForLocalRecords: Generating local RMV events for %s", ARDisplayString(m, rr)); rr->resrec.RecordType = kDNSRecordTypeShared; AnswerAllLocalQuestionsWithLocalAuthRecord(m, rr, QC_rmv); if (m->CurrentRecord == rr) // If rr still exists in list, restore its state now { rr->resrec.RecordType = kDNSRecordTypeDeregistering; rr->AnsweredLocalQ = mDNSfalse; // SendResponses normally calls CompleteDeregistration after sending goodbyes. // For LocalOnly records, we don't do that and hence we need to do that here. if (RRLocalOnly(rr)) CompleteDeregistration(m, rr); } } if (m->CurrentRecord == rr) // If m->CurrentRecord was not auto-advanced, do it ourselves now m->CurrentRecord = rr->next; } } mDNSlocal void TimeoutQuestions_internal(mDNS *const m, DNSQuestion* questions, mDNSInterfaceID InterfaceID) { if (m->CurrentQuestion) LogMsg("TimeoutQuestions ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = questions; while (m->CurrentQuestion) { DNSQuestion *const q = m->CurrentQuestion; if (q->StopTime) { if (!q->TimeoutQuestion) LogMsg("TimeoutQuestions: ERROR!! TimeoutQuestion not set, but StopTime set for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); if (m->timenow - q->StopTime >= 0) { LogInfo("TimeoutQuestions: question %p %##s timed out, time %d", q, q->qname.c, m->timenow - q->StopTime); q->LOAddressAnswers = 0; // unset since timing out the question GenerateNegativeResponse(m, InterfaceID, QC_forceresponse); if (m->CurrentQuestion == q) q->StopTime = 0; } else { if (m->NextScheduledStopTime - q->StopTime > 0) m->NextScheduledStopTime = q->StopTime; } } // If m->CurrentQuestion wasn't modified out from under us, advance it now // We can't do this at the start of the loop because GenerateNegativeResponse // depends on having m->CurrentQuestion point to the right question if (m->CurrentQuestion == q) m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } mDNSlocal void TimeoutQuestions(mDNS *const m) { m->NextScheduledStopTime = m->timenow + FutureTime; // push reschedule of TimeoutQuestions to way off into the future TimeoutQuestions_internal(m, m->Questions, mDNSInterface_Any); TimeoutQuestions_internal(m, m->LocalOnlyQuestions, mDNSInterface_LocalOnly); } mDNSlocal void mDNSCoreFreeProxyRR(mDNS *const m) { AuthRecord *rrPtr = m->SPSRRSet, *rrNext = mDNSNULL; LogSPS("%s : Freeing stored sleep proxy A/AAAA records", __func__); while (rrPtr) { rrNext = rrPtr->next; mDNSPlatformMemFree(rrPtr); rrPtr = rrNext; } m->SPSRRSet = mDNSNULL; } mDNSexport mDNSs32 mDNS_Execute(mDNS *const m) { mDNS_Lock(m); // Must grab lock before trying to read m->timenow if (m->timenow - m->NextScheduledEvent >= 0) { int i; AuthRecord *head, *tail; mDNSu32 slot; AuthGroup *ag; verbosedebugf("mDNS_Execute"); if (m->CurrentQuestion) LogMsg("mDNS_Execute: ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); if (m->CurrentRecord) LogMsg("mDNS_Execute: ERROR m->CurrentRecord already set: %s", ARDisplayString(m, m->CurrentRecord)); // 1. If we're past the probe suppression time, we can clear it if (m->SuppressProbes && m->timenow - m->SuppressProbes >= 0) m->SuppressProbes = 0; // 2. If it's been more than ten seconds since the last probe failure, we can clear the counter if (m->NumFailedProbes && m->timenow - m->ProbeFailTime >= mDNSPlatformOneSecond * 10) m->NumFailedProbes = 0; // 3. Purge our cache of stale old records if (m->rrcache_size && m->timenow - m->NextCacheCheck >= 0) { mDNSu32 numchecked = 0; m->NextCacheCheck = m->timenow + FutureTime; for (slot = 0; slot < CACHE_HASH_SLOTS; slot++) { if (m->timenow - m->rrcache_nextcheck[slot] >= 0) { CacheGroup **cp = &m->rrcache_hash[slot]; m->rrcache_nextcheck[slot] = m->timenow + FutureTime; while (*cp) { debugf("m->NextCacheCheck %4d Slot %3d %##s", numchecked, slot, *cp ? (*cp)->name : (domainname*)"\x04NULL"); numchecked++; CheckCacheExpiration(m, slot, *cp); if ((*cp)->members) cp=&(*cp)->next; else ReleaseCacheGroup(m, cp); } } // Even if we didn't need to actually check this slot yet, still need to // factor its nextcheck time into our overall NextCacheCheck value if (m->NextCacheCheck - m->rrcache_nextcheck[slot] > 0) m->NextCacheCheck = m->rrcache_nextcheck[slot]; } debugf("m->NextCacheCheck %4d checked, next in %d", numchecked, m->NextCacheCheck - m->timenow); } if (m->timenow - m->NextScheduledSPS >= 0) { m->NextScheduledSPS = m->timenow + FutureTime; CheckProxyRecords(m, m->DuplicateRecords); // Clear m->DuplicateRecords first, then m->ResourceRecords CheckProxyRecords(m, m->ResourceRecords); } SetSPSProxyListChanged(mDNSNULL); // Perform any deferred BPF reconfiguration now // Check to see if we need to send any keepalives. Do this after we called CheckProxyRecords above // as records could have expired during that check if (m->timenow - m->NextScheduledKA >= 0) { m->NextScheduledKA = m->timenow + FutureTime; mDNS_SendKeepalives(m); } #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (m->NextBonjourDisableTime && (m->timenow - m->NextBonjourDisableTime >= 0)) { // Schedule immediate network change processing to leave the multicast group // since the delay time has expired since the previous active registration or query. m->NetworkChanged = m->timenow; m->NextBonjourDisableTime = 0; m->BonjourEnabled = 0; LogInfo("mDNS_Execute: Scheduled network changed processing to leave multicast group."); } #endif // Clear AnnounceOwner if necessary. (Do this *before* SendQueries() and SendResponses().) if (m->AnnounceOwner && m->timenow - m->AnnounceOwner >= 0) { m->AnnounceOwner = 0; } if (m->DelaySleep && m->timenow - m->DelaySleep >= 0) { m->DelaySleep = 0; if (m->SleepState == SleepState_Transferring) { LogSPS("Re-sleep delay passed; now checking for Sleep Proxy Servers"); BeginSleepProcessing(m); } } // 4. See if we can answer any of our new local questions from the cache for (i=0; m->NewQuestions && i<1000; i++) { if (m->NewQuestions->DelayAnswering && m->timenow - m->NewQuestions->DelayAnswering < 0) break; AnswerNewQuestion(m); } if (i >= 1000) LogMsg("mDNS_Execute: AnswerNewQuestion exceeded loop limit"); // Make sure we deliver *all* local RMV events, and clear the corresponding rr->AnsweredLocalQ flags, *before* // we begin generating *any* new ADD events in the m->NewLocalOnlyQuestions and m->NewLocalRecords loops below. for (i=0; i<1000 && m->LocalRemoveEvents; i++) { m->LocalRemoveEvents = mDNSfalse; m->CurrentRecord = m->ResourceRecords; CheckRmvEventsForLocalRecords(m); // Walk the LocalOnly records and deliver the RMV events for (slot = 0; slot < AUTH_HASH_SLOTS; slot++) for (ag = m->rrauth.rrauth_hash[slot]; ag; ag = ag->next) { m->CurrentRecord = ag->members; if (m->CurrentRecord) CheckRmvEventsForLocalRecords(m); } } if (i >= 1000) LogMsg("mDNS_Execute: m->LocalRemoveEvents exceeded loop limit"); for (i=0; m->NewLocalOnlyQuestions && i<1000; i++) AnswerNewLocalOnlyQuestion(m); if (i >= 1000) LogMsg("mDNS_Execute: AnswerNewLocalOnlyQuestion exceeded loop limit"); head = tail = mDNSNULL; for (i=0; i<1000 && m->NewLocalRecords && m->NewLocalRecords != head; i++) { AuthRecord *rr = m->NewLocalRecords; m->NewLocalRecords = m->NewLocalRecords->next; if (LocalRecordReady(rr)) { debugf("mDNS_Execute: Delivering Add event with LocalAuthRecord %s", ARDisplayString(m, rr)); AnswerAllLocalQuestionsWithLocalAuthRecord(m, rr, QC_add); } else if (!rr->next) { // If we have just one record that is not ready, we don't have to unlink and // reinsert. As the NewLocalRecords will be NULL for this case, the loop will // terminate and set the NewLocalRecords to rr. debugf("mDNS_Execute: Just one LocalAuthRecord %s, breaking out of the loop early", ARDisplayString(m, rr)); if (head != mDNSNULL || m->NewLocalRecords != mDNSNULL) LogMsg("mDNS_Execute: ERROR!!: head %p, NewLocalRecords %p", head, m->NewLocalRecords); head = rr; } else { AuthRecord **p = &m->ResourceRecords; // Find this record in our list of active records debugf("mDNS_Execute: Skipping LocalAuthRecord %s", ARDisplayString(m, rr)); // if this is the first record we are skipping, move to the end of the list. // if we have already skipped records before, append it at the end. while (*p && *p != rr) p=&(*p)->next; if (*p) *p = rr->next; // Cut this record from the list else { LogMsg("mDNS_Execute: ERROR!! Cannot find record %s in ResourceRecords list", ARDisplayString(m, rr)); break; } if (!head) { while (*p) p=&(*p)->next; *p = rr; head = tail = rr; } else { tail->next = rr; tail = rr; } rr->next = mDNSNULL; } } m->NewLocalRecords = head; debugf("mDNS_Execute: Setting NewLocalRecords to %s", (head ? ARDisplayString(m, head) : "NULL")); if (i >= 1000) LogMsg("mDNS_Execute: m->NewLocalRecords exceeded loop limit"); // Check to see if we have any new LocalOnly/P2P records to examine for delivering // to our local questions if (m->NewLocalOnlyRecords) { m->NewLocalOnlyRecords = mDNSfalse; for (slot = 0; slot < AUTH_HASH_SLOTS; slot++) { for (ag = m->rrauth.rrauth_hash[slot]; ag; ag = ag->next) { for (i=0; i<100 && ag->NewLocalOnlyRecords; i++) { AuthRecord *rr = ag->NewLocalOnlyRecords; ag->NewLocalOnlyRecords = ag->NewLocalOnlyRecords->next; // LocalOnly records should always be ready as they never probe if (LocalRecordReady(rr)) { debugf("mDNS_Execute: Delivering Add event with LocalAuthRecord %s", ARDisplayString(m, rr)); AnswerAllLocalQuestionsWithLocalAuthRecord(m, rr, QC_add); } else LogMsg("mDNS_Execute: LocalOnlyRecord %s not ready", ARDisplayString(m, rr)); } // We limit about 100 per AuthGroup that can be serviced at a time if (i >= 100) LogMsg("mDNS_Execute: ag->NewLocalOnlyRecords exceeded loop limit"); } } } // 5. See what packets we need to send if (m->mDNSPlatformStatus != mStatus_NoError || (m->SleepState == SleepState_Sleeping)) DiscardDeregistrations(m); if (m->mDNSPlatformStatus == mStatus_NoError && (m->SuppressSending == 0 || m->timenow - m->SuppressSending >= 0)) { // If the platform code is ready, and we're not suppressing packet generation right now // then send our responses, probes, and questions. // We check the cache first, because there might be records close to expiring that trigger questions to refresh them. // We send queries next, because there might be final-stage probes that complete their probing here, causing // them to advance to announcing state, and we want those to be included in any announcements we send out. // Finally, we send responses, including the previously mentioned records that just completed probing. m->SuppressSending = 0; // 6. Send Query packets. This may cause some probing records to advance to announcing state if (m->timenow - m->NextScheduledQuery >= 0 || m->timenow - m->NextScheduledProbe >= 0) SendQueries(m); if (m->timenow - m->NextScheduledQuery >= 0) { DNSQuestion *q; LogMsg("mDNS_Execute: SendQueries didn't send all its queries (%d - %d = %d) will try again in one second", m->timenow, m->NextScheduledQuery, m->timenow - m->NextScheduledQuery); m->NextScheduledQuery = m->timenow + mDNSPlatformOneSecond; for (q = m->Questions; q && q != m->NewQuestions; q=q->next) if (ActiveQuestion(q) && m->timenow - NextQSendTime(q) >= 0) LogMsg("mDNS_Execute: SendQueries didn't send %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); } if (m->timenow - m->NextScheduledProbe >= 0) { LogMsg("mDNS_Execute: SendQueries didn't send all its probes (%d - %d = %d) will try again in one second", m->timenow, m->NextScheduledProbe, m->timenow - m->NextScheduledProbe); m->NextScheduledProbe = m->timenow + mDNSPlatformOneSecond; } // 7. Send Response packets, including probing records just advanced to announcing state if (m->timenow - m->NextScheduledResponse >= 0) SendResponses(m); if (m->timenow - m->NextScheduledResponse >= 0) { LogMsg("mDNS_Execute: SendResponses didn't send all its responses; will try again in one second"); m->NextScheduledResponse = m->timenow + mDNSPlatformOneSecond; } } // Clear RandomDelay values, ready to pick a new different value next time m->RandomQueryDelay = 0; m->RandomReconfirmDelay = 0; // See if any questions (or local-only questions) have timed out if (m->NextScheduledStopTime && m->timenow - m->NextScheduledStopTime >= 0) TimeoutQuestions(m); #ifndef UNICAST_DISABLED if (m->NextSRVUpdate && m->timenow - m->NextSRVUpdate >= 0) UpdateAllSRVRecords(m); if (m->timenow - m->NextScheduledNATOp >= 0) CheckNATMappings(m); if (m->timenow - m->NextuDNSEvent >= 0) uDNS_Tasks(m); #endif #if APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR extern void serviceBLE(); if (m->NextBLEServiceTime && (m->timenow - m->NextBLEServiceTime >= 0)) serviceBLE(); #endif // APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR } // Note about multi-threaded systems: // On a multi-threaded system, some other thread could run right after the mDNS_Unlock(), // performing mDNS API operations that change our next scheduled event time. // // On multi-threaded systems (like the current Windows implementation) that have a single main thread // calling mDNS_Execute() (and other threads allowed to call mDNS API routines) it is the responsibility // of the mDNSPlatformUnlock() routine to signal some kind of stateful condition variable that will // signal whatever blocking primitive the main thread is using, so that it will wake up and execute one // more iteration of its loop, and immediately call mDNS_Execute() again. The signal has to be stateful // in the sense that if the main thread has not yet entered its blocking primitive, then as soon as it // does, the state of the signal will be noticed, causing the blocking primitive to return immediately // without blocking. This avoids the race condition between the signal from the other thread arriving // just *before* or just *after* the main thread enters the blocking primitive. // // On multi-threaded systems (like the current Mac OS 9 implementation) that are entirely timer-driven, // with no main mDNS_Execute() thread, it is the responsibility of the mDNSPlatformUnlock() routine to // set the timer according to the m->NextScheduledEvent value, and then when the timer fires, the timer // callback function should call mDNS_Execute() (and ignore the return value, which may already be stale // by the time it gets to the timer callback function). mDNS_Unlock(m); // Calling mDNS_Unlock is what gives m->NextScheduledEvent its new value return(m->NextScheduledEvent); } #ifndef UNICAST_DISABLED mDNSlocal void SuspendLLQs(mDNS *m) { DNSQuestion *q; for (q = m->Questions; q; q = q->next) if (ActiveQuestion(q) && !mDNSOpaque16IsZero(q->TargetQID) && q->LongLived && q->state == LLQ_Established) { q->ReqLease = 0; sendLLQRefresh(m, q); } } #endif // UNICAST_DISABLED mDNSlocal mDNSBool QuestionHasLocalAnswers(mDNS *const m, DNSQuestion *q) { AuthRecord *rr; AuthGroup *ag; ag = AuthGroupForName(&m->rrauth, q->qnamehash, &q->qname); if (ag) { for (rr = ag->members; rr; rr=rr->next) // Filter the /etc/hosts records - LocalOnly, Unique, A/AAAA/CNAME if (UniqueLocalOnlyRecord(rr) && LocalOnlyRecordAnswersQuestion(rr, q)) { LogInfo("QuestionHasLocalAnswers: Question %p %##s (%s) has local answer %s", q, q->qname.c, DNSTypeName(q->qtype), ARDisplayString(m, rr)); return mDNStrue; } } return mDNSfalse; } // ActivateUnicastQuery() is called from three places: // 1. When a new question is created // 2. On wake from sleep // 3. When the DNS configuration changes // In case 1 we don't want to mess with our established ThisQInterval and LastQTime (ScheduleImmediately is false) // In cases 2 and 3 we do want to cause the question to be resent immediately (ScheduleImmediately is true) mDNSlocal void ActivateUnicastQuery(mDNS *const m, DNSQuestion *const question, mDNSBool ScheduleImmediately) { if (!question->DuplicateOf) { debugf("ActivateUnicastQuery: %##s %s%s", question->qname.c, DNSTypeName(question->qtype), ScheduleImmediately ? " ScheduleImmediately" : ""); question->CNAMEReferrals = 0; if (question->nta) { CancelGetZoneData(m, question->nta); question->nta = mDNSNULL; } if (question->LongLived) { question->state = LLQ_Init; question->id = zeroOpaque64; question->servPort = zeroIPPort; if (question->tcp) { DisposeTCPConn(question->tcp); question->tcp = mDNSNULL; } } // If the question has local answers, then we don't want answers from outside if (ScheduleImmediately && !QuestionHasLocalAnswers(m, question)) { question->ThisQInterval = InitialQuestionInterval; question->LastQTime = m->timenow - question->ThisQInterval; SetNextQueryTime(m, question); } } } // Caller should hold the lock mDNSexport void mDNSCoreRestartAddressQueries(mDNS *const m, mDNSBool SearchDomainsChanged, FlushCache flushCacheRecords, CallbackBeforeStartQuery BeforeStartCallback, void *context) { DNSQuestion *q; DNSQuestion *restart = mDNSNULL; mDNS_CheckLock(m); // 1. Flush the cache records if (flushCacheRecords) flushCacheRecords(m); // 2. Even though we may have purged the cache records above, before it can generate RMV event // we are going to stop the question. Hence we need to deliver the RMV event before we // stop the question. // // CurrentQuestion is used by RmvEventsForQuestion below. While delivering RMV events, the // application callback can potentially stop the current question (detected by CurrentQuestion) or // *any* other question which could be the next one that we may process here. RestartQuestion // points to the "next" question which will be automatically advanced in mDNS_StopQuery_internal // if the "next" question is stopped while the CurrentQuestion is stopped if (m->RestartQuestion) LogMsg("mDNSCoreRestartAddressQueries: ERROR!! m->RestartQuestion already set: %##s (%s)", m->RestartQuestion->qname.c, DNSTypeName(m->RestartQuestion->qtype)); m->RestartQuestion = m->Questions; while (m->RestartQuestion) { q = m->RestartQuestion; m->RestartQuestion = q->next; // GetZoneData questions are referenced by other questions (original query that started the GetZoneData // question) through their "nta" pointer. Normally when the original query stops, it stops the // GetZoneData question and also frees the memory (See CancelGetZoneData). If we stop the GetZoneData // question followed by the original query that refers to this GetZoneData question, we will end up // freeing the GetZoneData question and then start the "freed" question at the end. if (IsGetZoneDataQuestion(q)) { DNSQuestion *refq = q->next; LogInfo("mDNSCoreRestartAddressQueries: Skipping GetZoneDataQuestion %p %##s (%s)", q, q->qname.c, DNSTypeName(q->qtype)); // debug stuff, we just try to find the referencing question and don't do much with it while (refq) { if (q == &refq->nta->question) { LogInfo("mDNSCoreRestartAddressQueries: Question %p %##s (%s) referring to GetZoneDataQuestion %p, not stopping", refq, refq->qname.c, DNSTypeName(refq->qtype), q); } refq = refq->next; } continue; } // This function is called when /etc/hosts changes and that could affect A, AAAA and CNAME queries if (q->qtype != kDNSType_A && q->qtype != kDNSType_AAAA && q->qtype != kDNSType_CNAME) continue; // If the search domains did not change, then we restart all the queries. Otherwise, only // for queries for which we "might" have appended search domains ("might" because we may // find results before we apply search domains even though AppendSearchDomains is set to 1) if (!SearchDomainsChanged || q->AppendSearchDomains) { // NOTE: CacheRecordRmvEventsForQuestion will not generate RMV events for queries that have non-zero // LOAddressAnswers. Hence it is important that we call CacheRecordRmvEventsForQuestion before // LocalRecordRmvEventsForQuestion (which decrements LOAddressAnswers). Let us say that // /etc/hosts has an A Record for web.apple.com. Any queries for web.apple.com will be answered locally. // But this can't prevent a CNAME/AAAA query to not to be sent on the wire. When it is sent on the wire, // it could create cache entries. When we are restarting queries, we can't deliver the cache RMV events // for the original query using these cache entries as ADDs were never delivered using these cache // entries and hence this order is needed. // If the query is suppressed, the RMV events won't be delivered if (!CacheRecordRmvEventsForQuestion(m, q)) { LogInfo("mDNSCoreRestartAddressQueries: Question deleted while delivering Cache Record RMV events"); continue; } // Suppressed status does not affect questions that are answered using local records if (!LocalRecordRmvEventsForQuestion(m, q)) { LogInfo("mDNSCoreRestartAddressQueries: Question deleted while delivering Local Record RMV events"); continue; } LogInfo("mDNSCoreRestartAddressQueries: Stop question %p %##s (%s), AppendSearchDomains %d", q, q->qname.c, DNSTypeName(q->qtype), q->AppendSearchDomains); mDNS_StopQuery_internal(m, q); if (q->ResetHandler) q->ResetHandler(q); q->next = restart; restart = q; } } // 3. Callback before we start the query if (BeforeStartCallback) BeforeStartCallback(m, context); // 4. Restart all the stopped queries while (restart) { q = restart; restart = restart->next; q->next = mDNSNULL; LogInfo("mDNSCoreRestartAddressQueries: Start question %p %##s (%s)", q, q->qname.c, DNSTypeName(q->qtype)); mDNS_StartQuery_internal(m, q); } } mDNSexport void mDNSCoreRestartQueries(mDNS *const m) { DNSQuestion *q; #ifndef UNICAST_DISABLED // Retrigger all our uDNS questions if (m->CurrentQuestion) LogMsg("mDNSCoreRestartQueries: ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); m->CurrentQuestion = m->Questions; while (m->CurrentQuestion) { q = m->CurrentQuestion; m->CurrentQuestion = m->CurrentQuestion->next; if (!mDNSOpaque16IsZero(q->TargetQID) && ActiveQuestion(q)) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_querier_forget(&q->querier); #endif ActivateUnicastQuery(m, q, mDNStrue); } } #endif // Retrigger all our mDNS questions for (q = m->Questions; q; q=q->next) // Scan our list of questions mDNSCoreRestartQuestion(m, q); } // restart question if it's multicast and currently active mDNSexport void mDNSCoreRestartQuestion(mDNS *const m, DNSQuestion *q) { if (mDNSOpaque16IsZero(q->TargetQID) && ActiveQuestion(q)) { q->ThisQInterval = InitialQuestionInterval; // MUST be > zero for an active question q->RequestUnicast = kDefaultRequestUnicastCount; q->LastQTime = m->timenow - q->ThisQInterval; q->RecentAnswerPkts = 0; ExpireDupSuppressInfo(q->DupSuppress, m->timenow); m->NextScheduledQuery = m->timenow; } } // restart the probe/announce cycle for multicast record mDNSexport void mDNSCoreRestartRegistration(mDNS *const m, AuthRecord *rr, int announceCount) { if (!AuthRecord_uDNS(rr)) { if (rr->resrec.RecordType == kDNSRecordTypeVerified && !rr->DependentOn) rr->resrec.RecordType = kDNSRecordTypeUnique; rr->ProbeCount = DefaultProbeCountForRecordType(rr->resrec.RecordType); if (mDNS_KeepaliveRecord(&rr->resrec)) { rr->AnnounceCount = 0; // Do not announce keepalive records } else { // announceCount < 0 indicates default announce count should be used if (announceCount < 0) announceCount = InitialAnnounceCount; if (rr->AnnounceCount < (mDNSu8)announceCount) rr->AnnounceCount = (mDNSu8)announceCount; } rr->SendNSECNow = mDNSNULL; InitializeLastAPTime(m, rr); } } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Power Management (Sleep/Wake) #endif mDNSexport void mDNS_UpdateAllowSleep(mDNS *const m) { #ifndef IDLESLEEPCONTROL_DISABLED mDNSBool allowSleep = mDNStrue; char reason[128]; reason[0] = 0; if (m->SystemSleepOnlyIfWakeOnLAN) { // Don't sleep if we are a proxy for any services if (m->ProxyRecords) { allowSleep = mDNSfalse; mDNS_snprintf(reason, sizeof(reason), "sleep proxy for %d records", m->ProxyRecords); LogInfo("mDNS_UpdateAllowSleep: Sleep disabled because we are proxying %d records", m->ProxyRecords); } if (allowSleep && mDNSCoreHaveAdvertisedMulticastServices(m)) { // Scan the list of active interfaces NetworkInterfaceInfo *intf; for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) { if (intf->McastTxRx && !intf->Loopback && !mDNSPlatformInterfaceIsD2D(intf->InterfaceID)) { // Disallow sleep if this interface doesn't support NetWake if (!intf->NetWake) { allowSleep = mDNSfalse; mDNS_snprintf(reason, sizeof(reason), "%s does not support NetWake", intf->ifname); LogInfo("mDNS_UpdateAllowSleep: Sleep disabled because %s does not support NetWake", intf->ifname); break; } // If the interface can be an in-NIC Proxy, we should check if it can accomodate all the records // that will be offloaded. If not, we should prevent sleep. // This check will be possible once the lower layers provide an API to query the space available for offloads on the NIC. #if APPLE_OSX_mDNSResponder if (!SupportsInNICProxy(intf)) #endif { // Disallow sleep if there is no sleep proxy server const CacheRecord *cr = FindSPSInCache1(m, &intf->NetWakeBrowse, mDNSNULL, mDNSNULL); if ( cr == mDNSNULL) { allowSleep = mDNSfalse; mDNS_snprintf(reason, sizeof(reason), "No sleep proxy server on %s", intf->ifname); LogInfo("mDNS_UpdateAllowSleep: Sleep disabled because %s has no sleep proxy server", intf->ifname); break; } else if (m->SPSType != 0) { mDNSu32 mymetric = LocalSPSMetric(m); mDNSu32 metric = SPSMetric(cr->resrec.rdata->u.name.c); if (metric >= mymetric) { allowSleep = mDNSfalse; mDNS_snprintf(reason, sizeof(reason), "No sleep proxy server with better metric on %s", intf->ifname); LogInfo("mDNS_UpdateAllowSleep: Sleep disabled because %s has no sleep proxy server with a better metric", intf->ifname); break; } } } } } } } // Call the platform code to enable/disable sleep mDNSPlatformSetAllowSleep(allowSleep, reason); #else (void) m; #endif /* !defined(IDLESLEEPCONTROL_DISABLED) */ } mDNSlocal mDNSBool mDNSUpdateOkToSend(mDNS *const m, AuthRecord *rr, NetworkInterfaceInfo *const intf, mDNSu32 scopeid) { // If it is not a uDNS record, check to see if the updateid is zero. "updateid" is cleared when we have // sent the resource record on all the interfaces. If the update id is not zero, check to see if it is time // to send. if (AuthRecord_uDNS(rr) || (rr->AuthFlags & AuthFlagsWakeOnly) || mDNSOpaque16IsZero(rr->updateid) || m->timenow - (rr->LastAPTime + rr->ThisAPInterval) < 0) { return mDNSfalse; } // If we have a pending registration for "scopeid", it is ok to send the update on that interface. // If the scopeid is too big to check for validity, we don't check against updateIntID. When // we successfully update on all the interfaces (with whatever set in "rr->updateIntID"), we clear // updateid and we should have returned from above. // // Note: scopeid is the same as intf->InterfaceID. It is passed in so that we don't have to call the // platform function to extract the value from "intf" every time. if ((scopeid >= (sizeof(rr->updateIntID) * mDNSNBBY) || bit_get_opaque64(rr->updateIntID, scopeid)) && (!rr->resrec.InterfaceID || rr->resrec.InterfaceID == intf->InterfaceID)) return mDNStrue; return mDNSfalse; } mDNSexport void UpdateRMAC(mDNS *const m, void *context) { IPAddressMACMapping *addrmap = (IPAddressMACMapping *)context ; m->CurrentRecord = m->ResourceRecords; if (!addrmap) { LogMsg("UpdateRMAC: Address mapping is NULL"); return; } while (m->CurrentRecord) { AuthRecord *rr = m->CurrentRecord; // If this is a non-sleep proxy keepalive record and the remote IP address matches, update the RData if (!rr->WakeUp.HMAC.l[0] && mDNS_KeepaliveRecord(&rr->resrec)) { mDNSAddr raddr; getKeepaliveRaddr(m, rr, &raddr); if (mDNSSameAddress(&raddr, &addrmap->ipaddr)) { // Update the MAC address only if it is not a zero MAC address mDNSEthAddr macAddr; mDNSu8 *ptr = GetValueForMACAddr((mDNSu8 *)(addrmap->ethaddr), (mDNSu8 *) (addrmap->ethaddr + sizeof(addrmap->ethaddr)), &macAddr); if (ptr != mDNSNULL && !mDNSEthAddressIsZero(macAddr)) { UpdateKeepaliveRData(m, rr, mDNSNULL, mDNStrue, (char *)(addrmap->ethaddr)); } } } m->CurrentRecord = rr->next; } if (addrmap) mDNSPlatformMemFree(addrmap); } mDNSexport mStatus UpdateKeepaliveRData(mDNS *const m, AuthRecord *rr, NetworkInterfaceInfo *const intf, mDNSBool updateMac, char *ethAddr) { mDNSu16 newrdlength; mDNSAddr laddr = zeroAddr; mDNSAddr raddr = zeroAddr; mDNSEthAddr eth = zeroEthAddr; mDNSIPPort lport = zeroIPPort; mDNSIPPort rport = zeroIPPort; mDNSu32 timeout = 0; mDNSu32 seq = 0; mDNSu32 ack = 0; mDNSu16 win = 0; UTF8str255 txt; int rdsize; RData *newrd; mDNSTCPInfo mti; mStatus ret; // Note: If we fail to update the DNS NULL record with additional information in this function, it will be registered // with the SPS like any other record. SPS will not send keepalives if it does not have additional information. mDNS_ExtractKeepaliveInfo(rr, &timeout, &laddr, &raddr, ð, &seq, &ack, &lport, &rport, &win); if (!timeout || mDNSAddressIsZero(&laddr) || mDNSAddressIsZero(&raddr) || mDNSIPPortIsZero(lport) || mDNSIPPortIsZero(rport)) { LogMsg("UpdateKeepaliveRData: not a valid record %s for keepalive %#a:%d %#a:%d", ARDisplayString(m, rr), &laddr, lport.NotAnInteger, &raddr, rport.NotAnInteger); return mStatus_UnknownErr; } if (updateMac) { if (laddr.type == mDNSAddrType_IPv4) newrdlength = mDNS_snprintf((char *)&txt.c[1], sizeof(txt.c) - 1, "t=%d i=%d c=%d h=%#a d=%#a l=%u r=%u m=%s", timeout, kKeepaliveRetryInterval, kKeepaliveRetryCount, &laddr, &raddr, mDNSVal16(lport), mDNSVal16(rport), ethAddr); else newrdlength = mDNS_snprintf((char *)&txt.c[1], sizeof(txt.c) - 1, "t=%d i=%d c=%d H=%#a D=%#a l=%u r=%u m=%s", timeout, kKeepaliveRetryInterval, kKeepaliveRetryCount, &laddr, &raddr, mDNSVal16(lport), mDNSVal16(rport), ethAddr); } else { // If this keepalive packet would be sent on a different interface than the current one that we are processing // now, then we don't update the DNS NULL record. But we do not prevent it from registering with the SPS. When SPS sees // this DNS NULL record, it does not send any keepalives as it does not have all the information mDNSPlatformMemZero(&mti, sizeof (mDNSTCPInfo)); ret = mDNSPlatformRetrieveTCPInfo(&laddr, &lport, &raddr, &rport, &mti); if (ret != mStatus_NoError) { LogMsg("mDNSPlatformRetrieveTCPInfo: mDNSPlatformRetrieveTCPInfo failed %d", ret); return ret; } if ((intf != mDNSNULL) && (mti.IntfId != intf->InterfaceID)) { LogInfo("mDNSPlatformRetrieveTCPInfo: InterfaceID mismatch mti.IntfId = %p InterfaceID = %p", mti.IntfId, intf->InterfaceID); return mStatus_BadParamErr; } if (laddr.type == mDNSAddrType_IPv4) newrdlength = mDNS_snprintf((char *)&txt.c[1], sizeof(txt.c) - 1, "t=%d i=%d c=%d h=%#a d=%#a l=%u r=%u m=%.6a s=%u a=%u w=%u", timeout, kKeepaliveRetryInterval, kKeepaliveRetryCount, &laddr, &raddr, mDNSVal16(lport), mDNSVal16(rport), ð, mti.seq, mti.ack, mti.window); else newrdlength = mDNS_snprintf((char *)&txt.c[1], sizeof(txt.c) - 1, "t=%d i=%d c=%d H=%#a D=%#a l=%u r=%u m=%.6a s=%u a=%u w=%u", timeout, kKeepaliveRetryInterval, kKeepaliveRetryCount, &laddr, &raddr, mDNSVal16(lport), mDNSVal16(rport), ð, mti.seq, mti.ack, mti.window); } // Did we insert a null byte at the end ? if (newrdlength == (sizeof(txt.c) - 1)) { LogMsg("UpdateKeepaliveRData: could not allocate memory %s", ARDisplayString(m, rr)); return mStatus_NoMemoryErr; } // Include the length for the null byte at the end txt.c[0] = newrdlength + 1; // Account for the first length byte and the null byte at the end newrdlength += 2; rdsize = newrdlength > sizeof(RDataBody) ? newrdlength : sizeof(RDataBody); newrd = (RData *) mDNSPlatformMemAllocate(sizeof(RData) - sizeof(RDataBody) + rdsize); if (!newrd) { LogMsg("UpdateKeepaliveRData: ptr NULL"); return mStatus_NoMemoryErr; } newrd->MaxRDLength = (mDNSu16) rdsize; mDNSPlatformMemCopy(&newrd->u, txt.c, newrdlength); // If we are updating the record for the first time, rdata points to rdatastorage as the rdata memory // was allocated as part of the AuthRecord itself. We allocate memory when we update the AuthRecord. // If the resource record has data that we allocated in a previous pass (to update MAC address), // free that memory here before copying in the new data. if ( rr->resrec.rdata != &rr->rdatastorage) { LogSPS("UpdateKeepaliveRData: Freed allocated memory for keep alive packet: %s ", ARDisplayString(m, rr)); mDNSPlatformMemFree(rr->resrec.rdata); } SetNewRData(&rr->resrec, newrd, newrdlength); // Update our rdata LogSPS("UpdateKeepaliveRData: successfully updated the record %s", ARDisplayString(m, rr)); return mStatus_NoError; } mDNSlocal void SendSPSRegistrationForOwner(mDNS *const m, NetworkInterfaceInfo *const intf, const mDNSOpaque16 id, const OwnerOptData *const owner) { const int optspace = DNSOpt_Header_Space + DNSOpt_LeaseData_Space + DNSOpt_Owner_Space(&m->PrimaryMAC, &intf->MAC); const int sps = intf->NextSPSAttempt / 3; AuthRecord *rr; mDNSOpaque16 msgid; mDNSu32 scopeid; scopeid = mDNSPlatformInterfaceIndexfromInterfaceID(m, intf->InterfaceID, mDNStrue); if (!intf->SPSAddr[sps].type) { intf->NextSPSAttemptTime = m->timenow + mDNSPlatformOneSecond; if (m->NextScheduledSPRetry - intf->NextSPSAttemptTime > 0) m->NextScheduledSPRetry = intf->NextSPSAttemptTime; LogSPS("SendSPSRegistration: %s SPS %d (%d) %##s not yet resolved", intf->ifname, intf->NextSPSAttempt, sps, intf->NetWakeResolve[sps].qname.c); goto exit; } // Mark our mDNS records (not unicast records) for transfer to SPS if (mDNSOpaque16IsZero(id)) { // We may have to register this record over multiple interfaces and we don't want to // overwrite the id. We send the registration over interface X with id "IDX" and before // we get a response, we overwrite with id "IDY" for interface Y and we won't accept responses // for "IDX". Hence, we want to use the same ID across all interfaces. // // In the case of sleep proxy server transfering its records when it goes to sleep, the owner // option check below will set the same ID across the records from the same owner. Records // with different owner option gets different ID. msgid = mDNS_NewMessageID(m); for (rr = m->ResourceRecords; rr; rr=rr->next) { if (!(rr->AuthFlags & AuthFlagsWakeOnly) && rr->resrec.RecordType > kDNSRecordTypeDeregistering) { if (rr->resrec.InterfaceID == intf->InterfaceID || (!rr->resrec.InterfaceID && (rr->ForceMCast || IsLocalDomain(rr->resrec.name)))) { if (mDNSPlatformMemSame(owner, &rr->WakeUp, sizeof(*owner))) { rr->SendRNow = mDNSInterfaceMark; // mark it now // When we are registering on the first interface, rr->updateid is zero in which case // initialize with the new ID. For subsequent interfaces, we want to use the same ID. // At the end, all the updates sent across all the interfaces with the same ID. if (mDNSOpaque16IsZero(rr->updateid)) rr->updateid = msgid; else msgid = rr->updateid; } } } } } else msgid = id; while (1) { mDNSu8 *p = m->omsg.data; // To comply with RFC 2782, PutResourceRecord suppresses name compression for SRV records in unicast updates. // For now we follow that same logic for SPS registrations too. // If we decide to compress SRV records in SPS registrations in the future, we can achieve that by creating our // initial DNSMessage with h.flags set to zero, and then update it to UpdateReqFlags right before sending the packet. InitializeDNSMessage(&m->omsg.h, msgid, UpdateReqFlags); for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->SendRNow || mDNSUpdateOkToSend(m, rr, intf, scopeid)) { if (mDNSPlatformMemSame(owner, &rr->WakeUp, sizeof(*owner))) { mDNSu8 *newptr; const mDNSu8 *const limit = m->omsg.data + (m->omsg.h.mDNS_numUpdates ? NormalMaxDNSMessageData : AbsoluteMaxDNSMessageData) - optspace; // If we can't update the keepalive record, don't send it if (mDNS_KeepaliveRecord(&rr->resrec) && (UpdateKeepaliveRData(m, rr, intf, mDNSfalse, mDNSNULL) != mStatus_NoError)) { if (scopeid < (sizeof(rr->updateIntID) * mDNSNBBY)) { bit_clr_opaque64(rr->updateIntID, scopeid); } rr->SendRNow = mDNSNULL; continue; } if (rr->resrec.RecordType & kDNSRecordTypeUniqueMask) rr->resrec.rrclass |= kDNSClass_UniqueRRSet; // Temporarily set the 'unique' bit so PutResourceRecord will set it newptr = PutResourceRecordTTLWithLimit(&m->omsg, p, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit); rr->resrec.rrclass &= ~kDNSClass_UniqueRRSet; // Make sure to clear 'unique' bit back to normal state if (!newptr) LogSPS("SendSPSRegistration put %s FAILED %d/%d %s", intf->ifname, p - m->omsg.data, limit - m->omsg.data, ARDisplayString(m, rr)); else { LogSPS("SendSPSRegistration put %s 0x%x 0x%x (updateid %d) %s", intf->ifname, rr->updateIntID.l[1], rr->updateIntID.l[0], mDNSVal16(m->omsg.h.id), ARDisplayString(m, rr)); rr->SendRNow = mDNSNULL; rr->ThisAPInterval = mDNSPlatformOneSecond; rr->LastAPTime = m->timenow; // should be initialized above if (mDNSOpaque16IsZero(rr->updateid)) LogMsg("SendSPSRegistration: ERROR!! rr %s updateid is zero", ARDisplayString(m, rr)); if (m->NextScheduledResponse - (rr->LastAPTime + rr->ThisAPInterval) >= 0) m->NextScheduledResponse = (rr->LastAPTime + rr->ThisAPInterval); p = newptr; } } } if (!m->omsg.h.mDNS_numUpdates) break; else { AuthRecord opt; mDNS_SetupResourceRecord(&opt, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); opt.resrec.rrclass = NormalMaxDNSMessageData; opt.resrec.rdlength = sizeof(rdataOPT) * 2; // Two options in this OPT record opt.resrec.rdestimate = sizeof(rdataOPT) * 2; opt.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease; opt.resrec.rdata->u.opt[0].optlen = DNSOpt_LeaseData_Space - 4; opt.resrec.rdata->u.opt[0].u.updatelease = DEFAULT_UPDATE_LEASE; if (!owner->HMAC.l[0]) // If no owner data, SetupOwnerOpt(m, intf, &opt.resrec.rdata->u.opt[1]); // use our own interface information else // otherwise, use the owner data we were given { opt.resrec.rdata->u.opt[1].u.owner = *owner; opt.resrec.rdata->u.opt[1].opt = kDNSOpt_Owner; opt.resrec.rdata->u.opt[1].optlen = DNSOpt_Owner_Space(&owner->HMAC, &owner->IMAC) - 4; } LogSPS("SendSPSRegistration put %s %s", intf->ifname, ARDisplayString(m, &opt)); p = PutResourceRecordTTLWithLimit(&m->omsg, p, &m->omsg.h.numAdditionals, &opt.resrec, opt.resrec.rroriginalttl, m->omsg.data + AbsoluteMaxDNSMessageData); if (!p) LogMsg("SendSPSRegistration: Failed to put OPT record (%d updates) %s", m->omsg.h.mDNS_numUpdates, ARDisplayString(m, &opt)); else { mStatus err; LogSPS("SendSPSRegistration: Sending Update %s %d (%d) id %5d with %d records %d bytes to %#a:%d", intf->ifname, intf->NextSPSAttempt, sps, mDNSVal16(m->omsg.h.id), m->omsg.h.mDNS_numUpdates, p - m->omsg.data, &intf->SPSAddr[sps], mDNSVal16(intf->SPSPort[sps])); // if (intf->NextSPSAttempt < 5) m->omsg.h.flags = zeroID; // For simulating packet loss err = mDNSSendDNSMessage(m, &m->omsg, p, intf->InterfaceID, mDNSNULL, mDNSNULL, &intf->SPSAddr[sps], intf->SPSPort[sps], mDNSNULL, mDNSfalse); if (err) LogSPS("SendSPSRegistration: mDNSSendDNSMessage err %d", err); if (err && intf->SPSAddr[sps].type == mDNSAddrType_IPv4 && intf->NetWakeResolve[sps].ThisQInterval == -1) { LogSPS("SendSPSRegistration %d %##s failed to send to IPv4 address; will try IPv6 instead", sps, intf->NetWakeResolve[sps].qname.c); intf->NetWakeResolve[sps].qtype = kDNSType_AAAA; mDNS_StartQuery_internal(m, &intf->NetWakeResolve[sps]); return; } } } } intf->NextSPSAttemptTime = m->timenow + mDNSPlatformOneSecond * 10; // If successful, update NextSPSAttemptTime exit: if (mDNSOpaque16IsZero(id) && intf->NextSPSAttempt < 8) intf->NextSPSAttempt++; } mDNSlocal mDNSBool RecordIsFirstOccurrenceOfOwner(mDNS *const m, const AuthRecord *const rr) { AuthRecord *ar; for (ar = m->ResourceRecords; ar && ar != rr; ar=ar->next) if (mDNSPlatformMemSame(&rr->WakeUp, &ar->WakeUp, sizeof(rr->WakeUp))) return mDNSfalse; return mDNStrue; } mDNSlocal void mDNSCoreStoreProxyRR(mDNS *const m, const mDNSInterfaceID InterfaceID, AuthRecord *const rr) { AuthRecord *newRR = (AuthRecord *) mDNSPlatformMemAllocateClear(sizeof(*newRR)); if (newRR == mDNSNULL) { LogSPS("%s : could not allocate memory for new resource record", __func__); return; } mDNS_SetupResourceRecord(newRR, mDNSNULL, InterfaceID, rr->resrec.rrtype, rr->resrec.rroriginalttl, rr->resrec.RecordType, rr->ARType, mDNSNULL, mDNSNULL); AssignDomainName(&newRR->namestorage, &rr->namestorage); newRR->resrec.rdlength = DomainNameLength(rr->resrec.name); newRR->resrec.namehash = DomainNameHashValue(newRR->resrec.name); newRR->resrec.rrclass = rr->resrec.rrclass; if (rr->resrec.rrtype == kDNSType_A) { newRR->resrec.rdata->u.ipv4 = rr->resrec.rdata->u.ipv4; } else if (rr->resrec.rrtype == kDNSType_AAAA) { newRR->resrec.rdata->u.ipv6 = rr->resrec.rdata->u.ipv6; } SetNewRData(&newRR->resrec, mDNSNULL, 0); // Insert the new node at the head of the list. newRR->next = m->SPSRRSet; m->SPSRRSet = newRR; LogSPS("%s : Storing proxy record : %s ", __func__, ARDisplayString(m, rr)); } // Some records are interface specific and some are not. The ones that are supposed to be registered // on multiple interfaces need to be initialized with all the valid interfaces on which it will be sent. // updateIntID bit field tells us on which interfaces we need to register this record. When we get an // ack from the sleep proxy server, we clear the interface bit. This way, we know when a record completes // registration on all the interfaces mDNSlocal void SPSInitRecordsBeforeUpdate(mDNS *const m, mDNSOpaque64 updateIntID, mDNSBool *WakeOnlyService) { AuthRecord *ar; LogSPS("SPSInitRecordsBeforeUpdate: UpdateIntID 0x%x 0x%x", updateIntID.l[1], updateIntID.l[0]); *WakeOnlyService = mDNSfalse; // Before we store the A and AAAA records that we are going to register with the sleep proxy, // make sure that the old sleep proxy records are removed. mDNSCoreFreeProxyRR(m); // For records that are registered only on a specific interface, mark only that bit as it will // never be registered on any other interface. For others, it should be sent on all interfaces. for (ar = m->ResourceRecords; ar; ar=ar->next) { ar->updateIntID = zeroOpaque64; ar->updateid = zeroID; if (AuthRecord_uDNS(ar)) { continue; } if (ar->AuthFlags & AuthFlagsWakeOnly) { if (ar->resrec.RecordType == kDNSRecordTypeShared && ar->RequireGoodbye) { ar->ImmedAnswer = mDNSInterfaceMark; *WakeOnlyService = mDNStrue; continue; } } if (!ar->resrec.InterfaceID) { LogSPS("Setting scopeid (ALL) 0x%x 0x%x for %s", updateIntID.l[1], updateIntID.l[0], ARDisplayString(m, ar)); ar->updateIntID = updateIntID; } else { // Filter records that belong to interfaces that we won't register the records on. UpdateIntID captures // exactly this. mDNSu32 scopeid = mDNSPlatformInterfaceIndexfromInterfaceID(m, ar->resrec.InterfaceID, mDNStrue); if ((scopeid < (sizeof(updateIntID) * mDNSNBBY)) && bit_get_opaque64(updateIntID, scopeid)) { bit_set_opaque64(ar->updateIntID, scopeid); LogSPS("SPSInitRecordsBeforeUpdate: Setting scopeid(%d) 0x%x 0x%x for %s", scopeid, ar->updateIntID.l[1], ar->updateIntID.l[0], ARDisplayString(m, ar)); } else { LogSPS("SPSInitRecordsBeforeUpdate: scopeid %d beyond range or not valid for SPS registration", scopeid); } } // Store the A and AAAA records that we registered with the sleep proxy. // We will use this to prevent spurious name conflicts that may occur when we wake up if (ar->resrec.rrtype == kDNSType_A || ar->resrec.rrtype == kDNSType_AAAA) { mDNSCoreStoreProxyRR(m, ar->resrec.InterfaceID, ar); } } } mDNSlocal void SendSPSRegistration(mDNS *const m, NetworkInterfaceInfo *const intf, const mDNSOpaque16 id) { AuthRecord *ar; OwnerOptData owner = zeroOwner; SendSPSRegistrationForOwner(m, intf, id, &owner); for (ar = m->ResourceRecords; ar; ar=ar->next) { if (!mDNSPlatformMemSame(&owner, &ar->WakeUp, sizeof(owner)) && RecordIsFirstOccurrenceOfOwner(m, ar)) { owner = ar->WakeUp; SendSPSRegistrationForOwner(m, intf, id, &owner); } } } // RetrySPSRegistrations is called from SendResponses, with the lock held mDNSlocal void RetrySPSRegistrations(mDNS *const m) { AuthRecord *rr; NetworkInterfaceInfo *intf; // First make sure none of our interfaces' NextSPSAttemptTimes are inadvertently set to m->timenow + mDNSPlatformOneSecond * 10 for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) if (intf->NextSPSAttempt && intf->NextSPSAttemptTime == m->timenow + mDNSPlatformOneSecond * 10) intf->NextSPSAttemptTime++; // Retry any record registrations that are due for (rr = m->ResourceRecords; rr; rr=rr->next) if (!AuthRecord_uDNS(rr) && !mDNSOpaque16IsZero(rr->updateid) && m->timenow - (rr->LastAPTime + rr->ThisAPInterval) >= 0) { for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) { // If we still have registrations pending on this interface, send it now mDNSu32 scopeid = mDNSPlatformInterfaceIndexfromInterfaceID(m, intf->InterfaceID, mDNStrue); if ((scopeid >= (sizeof(rr->updateIntID) * mDNSNBBY) || bit_get_opaque64(rr->updateIntID, scopeid)) && (!rr->resrec.InterfaceID || rr->resrec.InterfaceID == intf->InterfaceID)) { LogSPS("RetrySPSRegistrations: 0x%x 0x%x (updateid %d) %s", rr->updateIntID.l[1], rr->updateIntID.l[0], mDNSVal16(rr->updateid), ARDisplayString(m, rr)); SendSPSRegistration(m, intf, rr->updateid); } } } // For interfaces where we did an SPS registration attempt, increment intf->NextSPSAttempt for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) if (intf->NextSPSAttempt && intf->NextSPSAttemptTime == m->timenow + mDNSPlatformOneSecond * 10 && intf->NextSPSAttempt < 8) intf->NextSPSAttempt++; } mDNSlocal void NetWakeResolve(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) { NetworkInterfaceInfo *intf = (NetworkInterfaceInfo *)question->QuestionContext; int sps = (int)(question - intf->NetWakeResolve); (void)m; // Unused LogSPS("NetWakeResolve: SPS: %d Add: %d %s", sps, AddRecord, RRDisplayString(m, answer)); if (!AddRecord) return; // Don't care about REMOVE events if (answer->rrtype != question->qtype) return; // Don't care about CNAMEs // if (answer->rrtype == kDNSType_AAAA && sps == 0) return; // To test failing to resolve sleep proxy's address if (answer->rrtype == kDNSType_SRV) { // 1. Got the SRV record; now look up the target host's IP address mDNS_StopQuery(m, question); intf->SPSPort[sps] = answer->rdata->u.srv.port; AssignDomainName(&question->qname, &answer->rdata->u.srv.target); question->qtype = kDNSType_A; mDNS_StartQuery(m, question); } else if (answer->rrtype == kDNSType_A && answer->rdlength == sizeof(mDNSv4Addr)) { // 2. Got an IPv4 address for the target host; record address and initiate an SPS registration if appropriate mDNS_StopQuery(m, question); question->ThisQInterval = -1; intf->SPSAddr[sps].type = mDNSAddrType_IPv4; intf->SPSAddr[sps].ip.v4 = answer->rdata->u.ipv4; mDNS_Lock(m); if (sps == intf->NextSPSAttempt/3) SendSPSRegistration(m, intf, zeroID); // If we're ready for this result, use it now mDNS_Unlock(m); } else if (answer->rrtype == kDNSType_A && answer->rdlength == 0) { // 3. Got negative response -- target host apparently has IPv6 disabled -- so try looking up the target host's IPv4 address(es) instead mDNS_StopQuery(m, question); LogSPS("NetWakeResolve: SPS %d %##s has no IPv4 address, will try IPv6 instead", sps, question->qname.c); question->qtype = kDNSType_AAAA; mDNS_StartQuery(m, question); } else if (answer->rrtype == kDNSType_AAAA && answer->rdlength == sizeof(mDNSv6Addr) && mDNSv6AddressIsLinkLocal(&answer->rdata->u.ipv6)) { // 4. Got the target host's IPv6 link-local address; record address and initiate an SPS registration if appropriate mDNS_StopQuery(m, question); question->ThisQInterval = -1; intf->SPSAddr[sps].type = mDNSAddrType_IPv6; intf->SPSAddr[sps].ip.v6 = answer->rdata->u.ipv6; mDNS_Lock(m); if (sps == intf->NextSPSAttempt/3) SendSPSRegistration(m, intf, zeroID); // If we're ready for this result, use it now mDNS_Unlock(m); } } mDNSexport mDNSBool mDNSCoreHaveAdvertisedMulticastServices(mDNS *const m) { AuthRecord *rr; for (rr = m->ResourceRecords; rr; rr=rr->next) if (mDNS_KeepaliveRecord(&rr->resrec) || (rr->resrec.rrtype == kDNSType_SRV && !AuthRecord_uDNS(rr) && !mDNSSameIPPort(rr->resrec.rdata->u.srv.port, DiscardPort))) return mDNStrue; return mDNSfalse; } #define WAKE_ONLY_SERVICE 1 #define AC_ONLY_SERVICE 2 #ifdef APPLE_OSX_mDNSResponder mDNSlocal void SendGoodbyesForSelectServices(mDNS *const m, mDNSBool *servicePresent, mDNSu32 serviceType) { AuthRecord *rr; *servicePresent = mDNSfalse; // Mark all the records we need to deregister and send them for (rr = m->ResourceRecords; rr; rr=rr->next) { // If the service type is wake only service and the auth flags match and requires a goodbye // OR if the service type is AC only and it is not a keepalive record, // mark the records we need to deregister and send them if ((serviceType == WAKE_ONLY_SERVICE && (rr->AuthFlags & AuthFlagsWakeOnly) && rr->resrec.RecordType == kDNSRecordTypeShared && rr->RequireGoodbye) || (serviceType == AC_ONLY_SERVICE && !mDNS_KeepaliveRecord(&rr->resrec))) { rr->ImmedAnswer = mDNSInterfaceMark; *servicePresent = mDNStrue; } } } #endif #ifdef APPLE_OSX_mDNSResponder // This function is used only in the case of local NIC proxy. For external // sleep proxy server, we do this in SPSInitRecordsBeforeUpdate when we // walk the resource records. mDNSlocal void SendGoodbyesForWakeOnlyService(mDNS *const m, mDNSBool *WakeOnlyService) { return SendGoodbyesForSelectServices(m, WakeOnlyService, WAKE_ONLY_SERVICE); } #endif // APPLE_OSX_mDNSResponder mDNSlocal void SendSleepGoodbyes(mDNS *const m, mDNSBool AllInterfaces, mDNSBool unicast) { AuthRecord *rr; m->SleepState = SleepState_Sleeping; // If AllInterfaces is not set, the caller has already marked it appropriately // on which interfaces this should be sent. if (AllInterfaces) { NetworkInterfaceInfo *intf; for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) { intf->SendGoodbyes = 1; } } if (unicast) { #ifndef UNICAST_DISABLED SleepRecordRegistrations(m); // If we have no SPS, need to deregister our uDNS records #endif /* UNICAST_DISABLED */ } // Mark all the records we need to deregister and send them for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.RecordType == kDNSRecordTypeShared && rr->RequireGoodbye) rr->ImmedAnswer = mDNSInterfaceMark; SendResponses(m); } /* * This function attempts to detect if multiple interfaces are on the same subnet. * It makes this determination based only on the IPv4 Addresses and subnet masks. * IPv6 link local addresses that are configured by default on all interfaces make * it hard to make this determination * * The 'real' fix for this would be to send out multicast packets over one interface * and conclude that multiple interfaces are on the same subnet only if these packets * are seen on other interfaces on the same system */ mDNSlocal mDNSBool skipSameSubnetRegistration(mDNS *const m, mDNSInterfaceID *regID, mDNSu32 count, mDNSInterfaceID intfid) { NetworkInterfaceInfo *intf; NetworkInterfaceInfo *newIntf; mDNSu32 i; for (newIntf = FirstInterfaceForID(m, intfid); newIntf; newIntf = newIntf->next) { if ((newIntf->InterfaceID != intfid) || (newIntf->ip.type != mDNSAddrType_IPv4)) { continue; } for ( i = 0; i < count; i++) { for (intf = FirstInterfaceForID(m, regID[i]); intf; intf = intf->next) { if ((intf->InterfaceID != regID[i]) || (intf->ip.type != mDNSAddrType_IPv4)) { continue; } if ((intf->ip.ip.v4.NotAnInteger & intf->mask.ip.v4.NotAnInteger) == (newIntf->ip.ip.v4.NotAnInteger & newIntf->mask.ip.v4.NotAnInteger)) { LogSPS("%s : Already registered for the same subnet (IPv4) for interface %s", __func__, intf->ifname); return (mDNStrue); } } } } return (mDNSfalse); } mDNSlocal void DoKeepaliveCallbacks(mDNS *m) { // Loop through the keepalive records and callback with an error m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { AuthRecord *const rr = m->CurrentRecord; if ((mDNS_KeepaliveRecord(&rr->resrec)) && (rr->resrec.RecordType != kDNSRecordTypeDeregistering)) { LogSPS("DoKeepaliveCallbacks: Invoking the callback for %s", ARDisplayString(m, rr)); if (rr->RecordCallback) rr->RecordCallback(m, rr, mStatus_BadStateErr); } if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } // BeginSleepProcessing is called, with the lock held, from either mDNS_Execute or mDNSCoreMachineSleep mDNSlocal void BeginSleepProcessing(mDNS *const m) { mDNSBool SendGoodbyes = mDNStrue; mDNSBool WakeOnlyService = mDNSfalse; mDNSBool invokeKACallback = mDNStrue; const CacheRecord *sps[3] = { mDNSNULL }; mDNSOpaque64 updateIntID = zeroOpaque64; mDNSInterfaceID registeredIntfIDS[128] = { 0 }; mDNSu32 registeredCount = 0; int skippedRegistrations = 0; m->NextScheduledSPRetry = m->timenow; // Clear out the SCDynamic entry that stores the external SPS information mDNSPlatformClearSPSData(); if (!m->SystemWakeOnLANEnabled) LogSPS("BeginSleepProcessing: m->SystemWakeOnLANEnabled is false"); else if (!mDNSCoreHaveAdvertisedMulticastServices(m)) LogSPS("BeginSleepProcessing: No advertised services"); else // If we have at least one advertised service { NetworkInterfaceInfo *intf; for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) { mDNSBool skipFullSleepProxyRegistration = mDNSfalse; // Intialize it to false. These values make sense only when SleepState is set to Sleeping. intf->SendGoodbyes = 0; // If it is not multicast capable, we could not have possibly discovered sleep proxy // servers. if (!intf->McastTxRx || mDNSPlatformInterfaceIsD2D(intf->InterfaceID)) { LogSPS("BeginSleepProcessing: %-6s Ignoring for registrations", intf->ifname); continue; } // If we are not capable of WOMP, then don't register with sleep proxy. // // Note: If we are not NetWake capable, we don't browse for the sleep proxy server. // We might find sleep proxy servers in the cache and start a resolve on them. // But then if the interface goes away, we won't stop these questions because // mDNS_DeactivateNetWake_internal assumes that a browse has been started for it // to stop both the browse and resolve questions. if (!intf->NetWake) { LogSPS("BeginSleepProcessing: %-6s not capable of magic packet wakeup", intf->ifname); intf->SendGoodbyes = 1; skippedRegistrations++; continue; } // Check if we have already registered with a sleep proxy for this subnet. // If so, then the subsequent in-NIC sleep proxy registration is limited to any keepalive records that belong // to the interface. if (skipSameSubnetRegistration(m, registeredIntfIDS, registeredCount, intf->InterfaceID)) { LogSPS("%s : Skipping full sleep proxy registration on %s", __func__, intf->ifname); skipFullSleepProxyRegistration = mDNStrue; } #if APPLE_OSX_mDNSResponder if (SupportsInNICProxy(intf)) { mDNSBool keepaliveOnly = mDNSfalse; const mStatus err = ActivateLocalProxy(intf, skipFullSleepProxyRegistration, &keepaliveOnly); if (!skipFullSleepProxyRegistration && !err) { SendGoodbyesForWakeOnlyService(m, &WakeOnlyService); // Send goodbyes for all advertised services if the only record offloaded was the keepalive record. SendGoodbyes = (keepaliveOnly) ? mDNStrue: mDNSfalse; invokeKACallback = mDNSfalse; LogSPS("BeginSleepProcessing: %-6s using local proxy", intf->ifname); // This will leave m->SleepState set to SleepState_Transferring, // which is okay because with no outstanding resolves, or updates in flight, // mDNSCoreReadyForSleep() will conclude correctly that all the updates have already completed registeredIntfIDS[registeredCount] = intf->InterfaceID; registeredCount++; } continue; } #endif // APPLE_OSX_mDNSResponder if (!skipFullSleepProxyRegistration) { #if APPLE_OSX_mDNSResponder // If on battery, do not attempt to offload to external sleep proxies if (m->SystemWakeOnLANEnabled == mDNS_WakeOnBattery) { LogSPS("BegingSleepProcessing: Not connected to AC power - Not registering with an external sleep proxy."); return; } #endif // APPLE_OSX_mDNSResponder FindSPSInCache(m, &intf->NetWakeBrowse, sps); if (!sps[0]) LogSPS("BeginSleepProcessing: %-6s %#a No Sleep Proxy Server found (Next Browse Q in %d, interval %d)", intf->ifname, &intf->ip, NextQSendTime(&intf->NetWakeBrowse) - m->timenow, intf->NetWakeBrowse.ThisQInterval); else { int i; mDNSu32 scopeid; SendGoodbyes = mDNSfalse; intf->NextSPSAttempt = 0; intf->NextSPSAttemptTime = m->timenow + mDNSPlatformOneSecond; scopeid = mDNSPlatformInterfaceIndexfromInterfaceID(m, intf->InterfaceID, mDNStrue); // Now we know for sure that we have to wait for registration to complete on this interface. if (scopeid < (sizeof(updateIntID) * mDNSNBBY)) bit_set_opaque64(updateIntID, scopeid); // Don't need to set m->NextScheduledSPRetry here because we already set "m->NextScheduledSPRetry = m->timenow" above for (i=0; i<3; i++) { #if ForceAlerts if (intf->SPSAddr[i].type) LogFatalError("BeginSleepProcessing: %s %d intf->SPSAddr[i].type %d", intf->ifname, i, intf->SPSAddr[i].type); if (intf->NetWakeResolve[i].ThisQInterval >= 0) LogFatalError("BeginSleepProcessing: %s %d intf->NetWakeResolve[i].ThisQInterval %d", intf->ifname, i, intf->NetWakeResolve[i].ThisQInterval); #endif intf->SPSAddr[i].type = mDNSAddrType_None; if (intf->NetWakeResolve[i].ThisQInterval >= 0) mDNS_StopQuery(m, &intf->NetWakeResolve[i]); intf->NetWakeResolve[i].ThisQInterval = -1; if (sps[i]) { LogSPS("BeginSleepProcessing: %-6s Found Sleep Proxy Server %d TTL %d %s", intf->ifname, i, sps[i]->resrec.rroriginalttl, CRDisplayString(m, sps[i])); mDNS_SetupQuestion(&intf->NetWakeResolve[i], intf->InterfaceID, &sps[i]->resrec.rdata->u.name, kDNSType_SRV, NetWakeResolve, intf); intf->NetWakeResolve[i].ReturnIntermed = mDNStrue; mDNS_StartQuery_internal(m, &intf->NetWakeResolve[i]); // If we are registering with a Sleep Proxy for a new subnet, add it to our list registeredIntfIDS[registeredCount] = intf->InterfaceID; registeredCount++; } } } } } } // If we have at least one interface on which we are registering with an external sleep proxy, // initialize all the records appropriately. if (!mDNSOpaque64IsZero(&updateIntID)) SPSInitRecordsBeforeUpdate(m, updateIntID, &WakeOnlyService); // Call the applicaitons that registered a keepalive record to inform them that we failed to offload // the records to a sleep proxy. if (invokeKACallback) { LogSPS("BeginSleepProcessing: Did not register with an in-NIC proxy - invoking the callbacks for KA records"); DoKeepaliveCallbacks(m); } // SendSleepGoodbyes last two arguments control whether we send goodbyes on all // interfaces and also deregister unicast registrations. // // - If there are no sleep proxy servers, then send goodbyes on all interfaces // for both multicast and unicast. // // - If we skipped registrations on some interfaces, then we have already marked // them appropriately above. We don't need to send goodbyes for unicast as // we have registered with at least one sleep proxy. // // - If we are not planning to send any goodbyes, then check for WakeOnlyServices. // // Note: If we are planning to send goodbyes, we mark the record with mDNSInterfaceAny // and call SendResponses which inturn calls ShouldSendGoodbyesBeforeSleep which looks // at WakeOnlyServices first. if (SendGoodbyes) { LogSPS("BeginSleepProcessing: Not registering with Sleep Proxy Server"); SendSleepGoodbyes(m, mDNStrue, mDNStrue); } else if (skippedRegistrations) { LogSPS("BeginSleepProcessing: Not registering with Sleep Proxy Server on all interfaces"); SendSleepGoodbyes(m, mDNSfalse, mDNSfalse); } else if (WakeOnlyService) { // If we saw WakeOnly service above, send the goodbyes now. LogSPS("BeginSleepProcessing: Sending goodbyes for WakeOnlyService"); SendResponses(m); } } // Call mDNSCoreMachineSleep(m, mDNStrue) when the machine is about to go to sleep. // Call mDNSCoreMachineSleep(m, mDNSfalse) when the machine is has just woken up. // Normally, the platform support layer below mDNSCore should call this, not the client layer above. mDNSexport void mDNSCoreMachineSleep(mDNS *const m, mDNSBool sleep) { AuthRecord *rr; LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_INFO, PUB_S " (old state %d) at %d", sleep ? "Sleeping" : "Waking", m->SleepState, m->timenow); if (sleep && !m->SleepState) // Going to sleep { mDNS_Lock(m); // If we're going to sleep, need to stop advertising that we're a Sleep Proxy Server if (m->SPSSocket) { mDNSu8 oldstate = m->SPSState; mDNS_DropLockBeforeCallback(); // mDNS_DeregisterService expects to be called without the lock held, so we emulate that here m->SPSState = 2; #ifndef SPC_DISABLED if (oldstate == 1) mDNS_DeregisterService(m, &m->SPSRecords); #else (void)oldstate; #endif mDNS_ReclaimLockAfterCallback(); } #ifdef _LEGACY_NAT_TRAVERSAL_ if (m->SSDPSocket) { mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } #endif m->SleepState = SleepState_Transferring; if (m->SystemWakeOnLANEnabled && m->DelaySleep) { // If we just woke up moments ago, allow ten seconds for networking to stabilize before going back to sleep LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep: Re-sleeping immediately after waking; will delay for %d ticks", m->DelaySleep - m->timenow); m->SleepLimit = NonZeroTime(m->DelaySleep + mDNSPlatformOneSecond * 10); } else { m->DelaySleep = 0; m->SleepLimit = NonZeroTime(m->timenow + mDNSPlatformOneSecond * 10); m->mDNSStats.Sleeps++; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) Querier_HandleSleep(); #endif BeginSleepProcessing(m); } #ifndef UNICAST_DISABLED SuspendLLQs(m); #endif LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep: m->SleepState %d (" PUB_S ") seq %d", m->SleepState, m->SleepState == SleepState_Transferring ? "Transferring" : m->SleepState == SleepState_Sleeping ? "Sleeping" : "?", m->SleepSeqNum); mDNS_Unlock(m); } else if (!sleep) // Waking up { mDNSu32 slot; CacheGroup *cg; CacheRecord *cr; NetworkInterfaceInfo *intf; mDNSs32 currtime, diff; mDNS_Lock(m); // Reset SleepLimit back to 0 now that we're awake again. m->SleepLimit = 0; // If we were previously sleeping, but now we're not, increment m->SleepSeqNum to indicate that we're entering a new period of wakefulness if (m->SleepState != SleepState_Awake) { m->SleepState = SleepState_Awake; m->SleepSeqNum++; // If the machine wakes and then immediately tries to sleep again (e.g. a maintenance wake) // then we enforce a minimum delay of five seconds before we begin sleep processing. // This is to allow time for the Ethernet link to come up, DHCP to get an address, mDNS to issue queries, etc., // before we make our determination of whether there's a Sleep Proxy out there we should register with. m->DelaySleep = NonZeroTime(m->timenow + kDarkWakeDelaySleep); } if (m->SPSState == 3) { m->SPSState = 0; mDNSCoreBeSleepProxyServer_internal(m, m->SPSType, m->SPSPortability, m->SPSMarginalPower, m->SPSTotalPower, m->SPSFeatureFlags); } m->mDNSStats.Wakes++; // ... and the same for NextSPSAttempt for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) intf->NextSPSAttempt = -1; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) Querier_HandleWake(); #endif // Restart unicast and multicast queries mDNSCoreRestartQueries(m); // and reactivtate service registrations m->NextSRVUpdate = NonZeroTime(m->timenow + mDNSPlatformOneSecond); LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep waking: NextSRVUpdate in %d %d", m->NextSRVUpdate - m->timenow, m->timenow); // 2. Re-validate our cache records currtime = mDNSPlatformUTC(); diff = currtime - m->TimeSlept; FORALL_CACHERECORDS(slot, cg, cr) { // Temporary fix: For unicast cache records, look at how much time we slept. // Adjust the RecvTime by the amount of time we slept so that we age the // cache record appropriately. If it is expired already, purge. If there // is a network change that happens after the wakeup, we might purge the // cache anyways and this helps only in the case where there are no network // changes across sleep/wakeup transition. // // Note: If there is a network/DNS server change that already happened and // these cache entries are already refreshed and we are getting a delayed // wake up notification, we might adjust the TimeRcvd based on the time slept // now which can cause the cache to purge pre-maturely. As this is not a very // common case, this should happen rarely. if (!cr->resrec.InterfaceID) { if (diff > 0) { mDNSu32 uTTL = RRUnadjustedTTL(cr->resrec.rroriginalttl); const mDNSs32 remain = uTTL - (m->timenow - cr->TimeRcvd) / mDNSPlatformOneSecond; // -if we have slept longer than the remaining TTL, purge and start fresh. // -if we have been sleeping for a long time, we could reduce TimeRcvd below by // a sufficiently big value which could cause the value to go into the future // because of the signed comparison of time. For this to happen, we should have been // sleeping really long (~24 days). For now, we want to be conservative and flush even // if we have slept for more than two days. if (diff >= remain || diff > (2 * 24 * 3600)) { LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep: " PRI_S ": Purging cache entry SleptTime %d, Remaining TTL %d", CRDisplayString(m, cr), diff, remain); mDNS_PurgeCacheResourceRecord(m, cr); continue; } cr->TimeRcvd -= (diff * mDNSPlatformOneSecond); if (m->timenow - (cr->TimeRcvd + ((mDNSs32)uTTL * mDNSPlatformOneSecond)) >= 0) { LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep: " PRI_S ": Purging after adjusting the remaining TTL %d by %d seconds", CRDisplayString(m, cr), remain, diff); mDNS_PurgeCacheResourceRecord(m, cr); } else { LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep: " PRI_S ": Adjusted the remain ttl %u by %d seconds", CRDisplayString(m, cr), remain, diff); } } } else { mDNS_Reconfirm_internal(m, cr, kDefaultReconfirmTimeForWake); } } // 3. Retrigger probing and announcing for all our authoritative records for (rr = m->ResourceRecords; rr; rr=rr->next) { if (AuthRecord_uDNS(rr)) { ActivateUnicastRegistration(m, rr); } else { mDNSCoreRestartRegistration(m, rr, -1); } } // 4. Refresh NAT mappings // We don't want to have to assume that all hardware can necessarily keep accurate // track of passage of time while asleep, so on wake we refresh our NAT mappings. // We typically wake up with no interfaces active, so there's no need to rush to try to find our external address. // But if we do get a network configuration change, mDNSMacOSXNetworkChanged will call uDNS_SetupDNSConfig, which // will call mDNS_SetPrimaryInterfaceInfo, which will call RecreateNATMappings to refresh them, potentially sooner // than five seconds from now. LogRedact(MDNS_LOG_CATEGORY_SPS, MDNS_LOG_DEBUG, "mDNSCoreMachineSleep: recreating NAT mappings in 5 seconds"); RecreateNATMappings(m, mDNSPlatformOneSecond * 5); mDNS_Unlock(m); } } mDNSexport mDNSBool mDNSCoreReadyForSleep(mDNS *m, mDNSs32 now) { DNSQuestion *q; AuthRecord *rr; NetworkInterfaceInfo *intf; mDNS_Lock(m); if (m->DelaySleep) goto notready; // If we've not hit the sleep limit time, and it's not time for our next retry, we can skip these checks if (m->SleepLimit - now > 0 && m->NextScheduledSPRetry - now > 0) goto notready; m->NextScheduledSPRetry = now + 0x40000000UL; // See if we might need to retransmit any lost Sleep Proxy Registrations for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) if (intf->NextSPSAttempt >= 0) { if (now - intf->NextSPSAttemptTime >= 0) { LogSPS("mDNSCoreReadyForSleep: retrying for %s SPS %d try %d", intf->ifname, intf->NextSPSAttempt/3, intf->NextSPSAttempt); SendSPSRegistration(m, intf, zeroID); // Don't need to "goto notready" here, because if we do still have record registrations // that have not been acknowledged yet, we'll catch that in the record list scan below. } else if (m->NextScheduledSPRetry - intf->NextSPSAttemptTime > 0) m->NextScheduledSPRetry = intf->NextSPSAttemptTime; } // Scan list of interfaces, and see if we're still waiting for any sleep proxy resolves to complete for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) { int sps = (intf->NextSPSAttempt == 0) ? 0 : (intf->NextSPSAttempt-1)/3; if (intf->NetWakeResolve[sps].ThisQInterval >= 0) { LogSPS("mDNSCoreReadyForSleep: waiting for SPS Resolve %s %##s (%s)", intf->ifname, intf->NetWakeResolve[sps].qname.c, DNSTypeName(intf->NetWakeResolve[sps].qtype)); goto spsnotready; } } // Scan list of registered records for (rr = m->ResourceRecords; rr; rr = rr->next) if (!AuthRecord_uDNS(rr)) if (!mDNSOpaque64IsZero(&rr->updateIntID)) { LogSPS("mDNSCoreReadyForSleep: waiting for SPS updateIntID 0x%x 0x%x (updateid %d) %s", rr->updateIntID.l[1], rr->updateIntID.l[0], mDNSVal16(rr->updateid), ARDisplayString(m,rr)); goto spsnotready; } // Scan list of private LLQs, and make sure they've all completed their handshake with the server for (q = m->Questions; q; q = q->next) if (!mDNSOpaque16IsZero(q->TargetQID) && q->LongLived && q->ReqLease == 0 && q->tcp) { LogSPS("mDNSCoreReadyForSleep: waiting for LLQ %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); goto notready; } // Scan list of registered records for (rr = m->ResourceRecords; rr; rr = rr->next) if (AuthRecord_uDNS(rr)) { if (rr->state == regState_Refresh && rr->tcp) { LogSPS("mDNSCoreReadyForSleep: waiting for Record updateIntID 0x%x 0x%x (updateid %d) %s", rr->updateIntID.l[1], rr->updateIntID.l[0], mDNSVal16(rr->updateid), ARDisplayString(m,rr)); goto notready; } } mDNS_Unlock(m); return mDNStrue; spsnotready: // If we failed to complete sleep proxy registration within ten seconds, we give up on that // and allow up to ten seconds more to complete wide-area deregistration instead if (now - m->SleepLimit >= 0) { LogMsg("Failed to register with SPS, now sending goodbyes"); for (intf = GetFirstActiveInterface(m->HostInterfaces); intf; intf = GetFirstActiveInterface(intf->next)) if (intf->NetWakeBrowse.ThisQInterval >= 0) { LogSPS("ReadyForSleep mDNS_DeactivateNetWake %s %##s (%s)", intf->ifname, intf->NetWakeResolve[0].qname.c, DNSTypeName(intf->NetWakeResolve[0].qtype)); mDNS_DeactivateNetWake_internal(m, intf); } for (rr = m->ResourceRecords; rr; rr = rr->next) if (!AuthRecord_uDNS(rr)) if (!mDNSOpaque64IsZero(&rr->updateIntID)) { LogSPS("ReadyForSleep clearing updateIntID 0x%x 0x%x (updateid %d) for %s", rr->updateIntID.l[1], rr->updateIntID.l[0], mDNSVal16(rr->updateid), ARDisplayString(m, rr)); rr->updateIntID = zeroOpaque64; } // We'd really like to allow up to ten seconds more here, // but if we don't respond to the sleep notification within 30 seconds // we'll be put back to sleep forcibly without the chance to schedule the next maintenance wake. // Right now we wait 16 sec after wake for all the interfaces to come up, then we wait up to 10 seconds // more for SPS resolves and record registrations to complete, which puts us at 26 seconds. // If we allow just one more second to send our goodbyes, that puts us at 27 seconds. m->SleepLimit = now + mDNSPlatformOneSecond * 1; SendSleepGoodbyes(m, mDNStrue, mDNStrue); } notready: mDNS_Unlock(m); return mDNSfalse; } mDNSexport mDNSs32 mDNSCoreIntervalToNextWake(mDNS *const m, mDNSs32 now, mDNSNextWakeReason *outReason) { AuthRecord *ar; // Even when we have no wake-on-LAN-capable interfaces, or we failed to find a sleep proxy, or we have other // failure scenarios, we still want to wake up in at most 120 minutes, to see if the network environment has changed. // E.g. we might wake up and find no wireless network because the base station got rebooted just at that moment, // and if that happens we don't want to just give up and go back to sleep and never try again. mDNSs32 e = now + (120 * 60 * mDNSPlatformOneSecond); // Sleep for at most 120 minutes mDNSNextWakeReason reason = mDNSNextWakeReason_UpkeepWake; NATTraversalInfo *nat; for (nat = m->NATTraversals; nat; nat=nat->next) { if (nat->Protocol && nat->ExpiryTime && nat->ExpiryTime - now > mDNSPlatformOneSecond*4) { mDNSs32 t = nat->ExpiryTime - (nat->ExpiryTime - now) / 10; // Wake up when 90% of the way to the expiry time if ((e - t) > 0) { e = t; reason = mDNSNextWakeReason_NATPortMappingRenewal; } LogSPS("ComputeWakeTime: %p %s Int %5d Ext %5d Err %d Retry %5d Interval %5d Expire %5d Wake %5d", nat, nat->Protocol == NATOp_MapTCP ? "TCP" : "UDP", mDNSVal16(nat->IntPort), mDNSVal16(nat->ExternalPort), nat->Result, nat->retryPortMap ? (nat->retryPortMap - now) / mDNSPlatformOneSecond : 0, nat->retryInterval / mDNSPlatformOneSecond, nat->ExpiryTime ? (nat->ExpiryTime - now) / mDNSPlatformOneSecond : 0, (t - now) / mDNSPlatformOneSecond); } } // This loop checks both the time we need to renew wide-area registrations, // and the time we need to renew Sleep Proxy registrations for (ar = m->ResourceRecords; ar; ar = ar->next) { if (ar->expire && ar->expire - now > mDNSPlatformOneSecond*4) { mDNSs32 t = ar->expire - (ar->expire - now) / 10; // Wake up when 90% of the way to the expiry time if ((e - t) > 0) { e = t; reason = mDNSNextWakeReason_RecordRegistrationRenewal; } LogSPS("ComputeWakeTime: %p Int %7d Next %7d Expire %7d Wake %7d %s", ar, ar->ThisAPInterval / mDNSPlatformOneSecond, (ar->LastAPTime + ar->ThisAPInterval - now) / mDNSPlatformOneSecond, ar->expire ? (ar->expire - now) / mDNSPlatformOneSecond : 0, (t - now) / mDNSPlatformOneSecond, ARDisplayString(m, ar)); } } if (outReason) { *outReason = reason; } return(e - now); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Packet Reception Functions #endif #define MustSendRecord(RR) ((RR)->NR_AnswerTo || (RR)->NR_AdditionalTo) mDNSlocal mDNSu8 *GenerateUnicastResponse(const DNSMessage *const query, const mDNSu8 *const end, const mDNSInterfaceID InterfaceID, mDNSBool LegacyQuery, DNSMessage *const response, AuthRecord *ResponseRecords) { mDNSu8 *responseptr = response->data; const mDNSu8 *const limit = response->data + sizeof(response->data); const mDNSu8 *ptr = query->data; AuthRecord *rr; mDNSu32 maxttl = (!InterfaceID) ? mDNSMaximumUnicastTTLSeconds : mDNSMaximumMulticastTTLSeconds; int i; // Initialize the response fields so we can answer the questions InitializeDNSMessage(&response->h, query->h.id, ResponseFlags); // *** // *** 1. Write out the list of questions we are actually going to answer with this packet // *** if (LegacyQuery) { maxttl = kStaticCacheTTL; for (i=0; ih.numQuestions; i++) // For each question... { DNSQuestion q; ptr = getQuestion(query, ptr, end, InterfaceID, &q); // get the question... if (!ptr) return(mDNSNULL); for (rr=ResponseRecords; rr; rr=rr->NextResponse) // and search our list of proposed answers { if (rr->NR_AnswerTo == ptr) // If we're going to generate a record answering this question { // then put the question in the question section responseptr = putQuestion(response, responseptr, limit, &q.qname, q.qtype, q.qclass); if (!responseptr) { debugf("GenerateUnicastResponse: Ran out of space for questions!"); return(mDNSNULL); } break; // break out of the ResponseRecords loop, and go on to the next question } } } if (response->h.numQuestions == 0) { LogMsg("GenerateUnicastResponse: ERROR! Why no questions?"); return(mDNSNULL); } } // *** // *** 2. Write Answers // *** for (rr=ResponseRecords; rr; rr=rr->NextResponse) if (rr->NR_AnswerTo) { mDNSu8 *p = PutResourceRecordTTL(response, responseptr, &response->h.numAnswers, &rr->resrec, maxttl < rr->resrec.rroriginalttl ? maxttl : rr->resrec.rroriginalttl); if (p) responseptr = p; else { debugf("GenerateUnicastResponse: Ran out of space for answers!"); response->h.flags.b[0] |= kDNSFlag0_TC; } } // *** // *** 3. Write Additionals // *** for (rr=ResponseRecords; rr; rr=rr->NextResponse) if (rr->NR_AdditionalTo && !rr->NR_AnswerTo) { mDNSu8 *p = PutResourceRecordTTL(response, responseptr, &response->h.numAdditionals, &rr->resrec, maxttl < rr->resrec.rroriginalttl ? maxttl : rr->resrec.rroriginalttl); if (p) responseptr = p; else debugf("GenerateUnicastResponse: No more space for additionals"); } return(responseptr); } // AuthRecord *our is our Resource Record // CacheRecord *pkt is the Resource Record from the response packet we've witnessed on the network // Returns 0 if there is no conflict // Returns +1 if there was a conflict and we won // Returns -1 if there was a conflict and we lost and have to rename mDNSlocal int CompareRData(const AuthRecord *const our, const CacheRecord *const pkt) { mDNSu8 ourdata[256], *ourptr = ourdata, *ourend; mDNSu8 pktdata[256], *pktptr = pktdata, *pktend; if (!our) { LogMsg("CompareRData ERROR: our is NULL"); return(+1); } if (!pkt) { LogMsg("CompareRData ERROR: pkt is NULL"); return(+1); } #if defined(__clang_analyzer__) // Get rid of analyzer warnings about ourptr and pktptr pointing to garbage after retruning from putRData(). // There are no clear indications from the analyzer of the cause of the supposed problem. mDNSPlatformMemZero(ourdata, 1); mDNSPlatformMemZero(pktdata, 1); #endif ourend = putRData(mDNSNULL, ourdata, ourdata + sizeof(ourdata), &our->resrec); pktend = putRData(mDNSNULL, pktdata, pktdata + sizeof(pktdata), &pkt->resrec); while (ourptr < ourend && pktptr < pktend && *ourptr == *pktptr) { ourptr++; pktptr++; } if (ourptr >= ourend && pktptr >= pktend) return(0); // If data identical, not a conflict if (ourptr >= ourend) return(-1); // Our data ran out first; We lost if (pktptr >= pktend) return(+1); // Packet data ran out first; We won if (*pktptr > *ourptr) return(-1); // Our data is numerically lower; We lost if (*pktptr < *ourptr) return(+1); // Packet data is numerically lower; We won LogMsg("CompareRData ERROR: Invalid state"); return(-1); } mDNSlocal mDNSBool PacketRecordMatches(const AuthRecord *const rr, const CacheRecord *const pktrr, const AuthRecord *const master) { if (IdenticalResourceRecord(&rr->resrec, &pktrr->resrec)) { const AuthRecord *r2 = rr; while (r2->DependentOn) r2 = r2->DependentOn; if (r2 == master) return(mDNStrue); } return(mDNSfalse); } // See if we have an authoritative record that's identical to this packet record, // whose canonical DependentOn record is the specified master record. // The DependentOn pointer is typically used for the TXT record of service registrations // It indicates that there is no inherent conflict detection for the TXT record // -- it depends on the SRV record to resolve name conflicts // If we find any identical ResourceRecords in our authoritative list, then follow their DependentOn // pointer chain (if any) to make sure we reach the canonical DependentOn record // If the record has no DependentOn, then just return that record's pointer // Returns NULL if we don't have any local RRs that are identical to the one from the packet mDNSlocal mDNSBool MatchDependentOn(const mDNS *const m, const CacheRecord *const pktrr, const AuthRecord *const master) { const AuthRecord *r1; for (r1 = m->ResourceRecords; r1; r1=r1->next) { if (PacketRecordMatches(r1, pktrr, master)) return(mDNStrue); } for (r1 = m->DuplicateRecords; r1; r1=r1->next) { if (PacketRecordMatches(r1, pktrr, master)) return(mDNStrue); } return(mDNSfalse); } // Find the canonical RRSet pointer for this RR received in a packet. // If we find any identical AuthRecord in our authoritative list, then follow its RRSet // pointers (if any) to make sure we return the canonical member of this name/type/class // Returns NULL if we don't have any local RRs that are identical to the one from the packet mDNSlocal const AuthRecord *FindRRSet(const mDNS *const m, const CacheRecord *const pktrr) { const AuthRecord *rr; for (rr = m->ResourceRecords; rr; rr=rr->next) { if (IdenticalResourceRecord(&rr->resrec, &pktrr->resrec)) { return(rr->RRSet ? rr->RRSet : rr); } } return(mDNSNULL); } // PacketRRConflict is called when we've received an RR (pktrr) which has the same name // as one of our records (our) but different rdata. // 1. If our record is not a type that's supposed to be unique, we don't care. // 2a. If our record is marked as dependent on some other record for conflict detection, ignore this one. // 2b. If the packet rr exactly matches one of our other RRs, and *that* record's DependentOn pointer // points to our record, ignore this conflict (e.g. the packet record matches one of our // TXT records, and that record is marked as dependent on 'our', its SRV record). // 3. If we have some *other* RR that exactly matches the one from the packet, and that record and our record // are members of the same RRSet, then this is not a conflict. mDNSlocal mDNSBool PacketRRConflict(const mDNS *const m, const AuthRecord *const our, const CacheRecord *const pktrr) { // If not supposed to be unique, not a conflict if (!(our->resrec.RecordType & kDNSRecordTypeUniqueMask)) return(mDNSfalse); // If a dependent record, not a conflict if (our->DependentOn || MatchDependentOn(m, pktrr, our)) return(mDNSfalse); else { // If the pktrr matches a member of ourset, not a conflict const AuthRecord *ourset = our->RRSet ? our->RRSet : our; const AuthRecord *pktset = FindRRSet(m, pktrr); if (pktset == ourset) return(mDNSfalse); // For records we're proxying, where we don't know the full // relationship between the records, having any matching record // in our AuthRecords list is sufficient evidence of non-conflict if (our->WakeUp.HMAC.l[0] && pktset) return(mDNSfalse); } // Okay, this is a conflict return(mDNStrue); } // Note: ResolveSimultaneousProbe calls mDNS_Deregister_internal which can call a user callback, which may change // the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSlocal void ResolveSimultaneousProbe(mDNS *const m, const DNSMessage *const query, const mDNSu8 *const end, DNSQuestion *q, AuthRecord *our) { int i; const mDNSu8 *ptr = LocateAuthorities(query, end); mDNSBool FoundUpdate = mDNSfalse; for (i = 0; i < query->h.numAuthorities; i++) { ptr = GetLargeResourceRecord(m, query, ptr, end, q->InterfaceID, kDNSRecordTypePacketAuth, &m->rec); if (!ptr) break; if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && CacheRecordAnswersQuestion(&m->rec.r, q)) { FoundUpdate = mDNStrue; if (PacketRRConflict(m, our, &m->rec.r)) { int result = (int)our->resrec.rrclass - (int)m->rec.r.resrec.rrclass; if (!result) result = (int)our->resrec.rrtype - (int)m->rec.r.resrec.rrtype; if (!result) result = CompareRData(our, &m->rec.r); if (result) { const char *const msg = (result < 0) ? "lost:" : (result > 0) ? "won: " : "tie: "; LogMsg("ResolveSimultaneousProbe: %p Pkt Record: %08lX %s", q->InterfaceID, m->rec.r.resrec.rdatahash, CRDisplayString(m, &m->rec.r)); LogMsg("ResolveSimultaneousProbe: %p Our Record %d %s %08lX %s", our->resrec.InterfaceID, our->ProbeCount, msg, our->resrec.rdatahash, ARDisplayString(m, our)); } // If we lost the tie-break for simultaneous probes, we don't immediately give up, because we might be seeing stale packets on the network. // Instead we pause for one second, to give the other host (if real) a chance to establish its name, and then try probing again. // If there really is another live host out there with the same name, it will answer our probes and we'll then rename. if (result < 0) { m->SuppressProbes = NonZeroTime(m->timenow + mDNSPlatformOneSecond); our->ProbeCount = DefaultProbeCountForTypeUnique; our->AnnounceCount = InitialAnnounceCount; InitializeLastAPTime(m, our); goto exit; } } #if 0 else { LogMsg("ResolveSimultaneousProbe: %p Pkt Record: %08lX %s", q->InterfaceID, m->rec.r.resrec.rdatahash, CRDisplayString(m, &m->rec.r)); LogMsg("ResolveSimultaneousProbe: %p Our Record %d ign: %08lX %s", our->resrec.InterfaceID, our->ProbeCount, our->resrec.rdatahash, ARDisplayString(m, our)); } #endif } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } if (!FoundUpdate) LogInfo("ResolveSimultaneousProbe: %##s (%s): No Update Record found", our->resrec.name->c, DNSTypeName(our->resrec.rrtype)); exit: m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } mDNSlocal CacheRecord *FindIdenticalRecordInCache(const mDNS *const m, const ResourceRecord *const pktrr) { CacheGroup *cg = CacheGroupForRecord(m, pktrr); CacheRecord *rr; mDNSBool match; for (rr = cg ? cg->members : mDNSNULL; rr; rr=rr->next) { if (!pktrr->InterfaceID) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) match = (pktrr->dnsservice == rr->resrec.dnsservice) ? mDNStrue : mDNSfalse; #else const mDNSu32 id1 = (pktrr->rDNSServer ? pktrr->rDNSServer->resGroupID : 0); const mDNSu32 id2 = (rr->resrec.rDNSServer ? rr->resrec.rDNSServer->resGroupID : 0); match = (id1 == id2); #endif } else match = (pktrr->InterfaceID == rr->resrec.InterfaceID); if (match && IdenticalSameNameRecord(pktrr, &rr->resrec)) break; } return(rr); } mDNSlocal void DeregisterProxyRecord(mDNS *const m, AuthRecord *const rr) { rr->WakeUp.HMAC = zeroEthAddr; // Clear HMAC so that mDNS_Deregister_internal doesn't waste packets trying to wake this host rr->RequireGoodbye = mDNSfalse; // and we don't want to send goodbye for it mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); SetSPSProxyListChanged(m->rec.r.resrec.InterfaceID); } mDNSlocal void ClearKeepaliveProxyRecords(mDNS *const m, const OwnerOptData *const owner, AuthRecord *const thelist, const mDNSInterfaceID InterfaceID) { if (m->CurrentRecord) LogMsg("ClearKeepaliveProxyRecords ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = thelist; // Normally, the RDATA of the keepalive record will be different each time and hence we always // clean up the keepalive record. while (m->CurrentRecord) { AuthRecord *const rr = m->CurrentRecord; if (InterfaceID == rr->resrec.InterfaceID && mDNSSameEthAddress(&owner->HMAC, &rr->WakeUp.HMAC)) { if (mDNS_KeepaliveRecord(&m->rec.r.resrec)) { LogSPS("ClearKeepaliveProxyRecords: Removing %3d H-MAC %.6a I-MAC %.6a %d %d %s", m->ProxyRecords, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, rr->WakeUp.seq, owner->seq, ARDisplayString(m, rr)); DeregisterProxyRecord(m, rr); } } // Mustn't advance m->CurrentRecord until *after* mDNS_Deregister_internal, because // new records could have been added to the end of the list as a result of that call. if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } // Called from mDNSCoreReceiveUpdate when we get a sleep proxy registration request, // to check our lists and discard any stale duplicates of this record we already have mDNSlocal void ClearIdenticalProxyRecords(mDNS *const m, const OwnerOptData *const owner, AuthRecord *const thelist) { if (m->CurrentRecord) LogMsg("ClearIdenticalProxyRecords ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = thelist; while (m->CurrentRecord) { AuthRecord *const rr = m->CurrentRecord; if (m->rec.r.resrec.InterfaceID == rr->resrec.InterfaceID && mDNSSameEthAddress(&owner->HMAC, &rr->WakeUp.HMAC)) if (IdenticalResourceRecord(&rr->resrec, &m->rec.r.resrec)) { LogSPS("ClearIdenticalProxyRecords: Removing %3d H-MAC %.6a I-MAC %.6a %d %d %s", m->ProxyRecords, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, rr->WakeUp.seq, owner->seq, ARDisplayString(m, rr)); DeregisterProxyRecord(m, rr); } // Mustn't advance m->CurrentRecord until *after* mDNS_Deregister_internal, because // new records could have been added to the end of the list as a result of that call. if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } // Called from ProcessQuery when we get an mDNS packet with an owner record in it mDNSlocal void ClearProxyRecords(mDNS *const m, const OwnerOptData *const owner, AuthRecord *const thelist) { if (m->CurrentRecord) LogMsg("ClearProxyRecords ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = thelist; while (m->CurrentRecord) { AuthRecord *const rr = m->CurrentRecord; if (m->rec.r.resrec.InterfaceID == rr->resrec.InterfaceID && mDNSSameEthAddress(&owner->HMAC, &rr->WakeUp.HMAC)) if (owner->seq != rr->WakeUp.seq || m->timenow - rr->TimeRcvd > mDNSPlatformOneSecond * 60) { if (rr->AddressProxy.type == mDNSAddrType_IPv6) { // We don't do this here because we know that the host is waking up at this point, so we don't send // Unsolicited Neighbor Advertisements -- even Neighbor Advertisements agreeing with what the host should be // saying itself -- because it can cause some IPv6 stacks to falsely conclude that there's an address conflict. #if MDNS_USE_Unsolicited_Neighbor_Advertisements LogSPS("NDP Announcement -- Releasing traffic for H-MAC %.6a I-MAC %.6a %s", &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m,rr)); SendNDP(m, NDP_Adv, NDP_Override, rr, &rr->AddressProxy.ip.v6, &rr->WakeUp.IMAC, &AllHosts_v6, &AllHosts_v6_Eth); #endif } LogSPS("ClearProxyRecords: Removing %3d AC %2d %02X H-MAC %.6a I-MAC %.6a %d %d %s", m->ProxyRecords, rr->AnnounceCount, rr->resrec.RecordType, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, rr->WakeUp.seq, owner->seq, ARDisplayString(m, rr)); if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) rr->resrec.RecordType = kDNSRecordTypeShared; rr->WakeUp.HMAC = zeroEthAddr; // Clear HMAC so that mDNS_Deregister_internal doesn't waste packets trying to wake this host rr->RequireGoodbye = mDNSfalse; // and we don't want to send goodbye for it, since real host is now back and functional mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); SetSPSProxyListChanged(m->rec.r.resrec.InterfaceID); } // Mustn't advance m->CurrentRecord until *after* mDNS_Deregister_internal, because // new records could have been added to the end of the list as a result of that call. if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } // ProcessQuery examines a received query to see if we have any answers to give mDNSlocal mDNSu8 *ProcessQuery(mDNS *const m, const DNSMessage *const query, const mDNSu8 *const end, const mDNSAddr *srcaddr, const mDNSInterfaceID InterfaceID, mDNSBool LegacyQuery, mDNSBool QueryWasMulticast, mDNSBool QueryWasLocalUnicast, DNSMessage *const response) { const mDNSBool FromLocalSubnet = mDNS_AddressIsLocalSubnet(m, InterfaceID, srcaddr); AuthRecord *ResponseRecords = mDNSNULL; AuthRecord **nrp = &ResponseRecords; #if POOF_ENABLED mDNSBool notD2D = !mDNSPlatformInterfaceIsD2D(InterfaceID); // We don't run the POOF algorithm on D2D interfaces. CacheRecord *ExpectedAnswers = mDNSNULL; // Records in our cache we expect to see updated CacheRecord **eap = &ExpectedAnswers; #endif // POOF_ENABLED DNSQuestion *DupQuestions = mDNSNULL; // Our questions that are identical to questions in this packet DNSQuestion **dqp = &DupQuestions; mDNSs32 delayresponse = 0; mDNSBool SendLegacyResponse = mDNSfalse; const mDNSu8 *ptr; mDNSu8 *responseptr = mDNSNULL; AuthRecord *rr; int i; // *** // *** 1. Look in Additional Section for an OPT record // *** ptr = LocateOptRR(query, end, DNSOpt_OwnerData_ID_Space); if (ptr) { ptr = GetLargeResourceRecord(m, query, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &m->rec); if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_OPT) { const rdataOPT *opt; const rdataOPT *const e = (const rdataOPT *)&m->rec.r.resrec.rdata->u.data[m->rec.r.resrec.rdlength]; // Find owner sub-option(s). We verify that the MAC is non-zero, otherwise we could inadvertently // delete all our own AuthRecords (which are identified by having zero MAC tags on them). for (opt = &m->rec.r.resrec.rdata->u.opt[0]; opt < e; opt++) if (opt->opt == kDNSOpt_Owner && opt->u.owner.vers == 0 && opt->u.owner.HMAC.l[0]) { ClearProxyRecords(m, &opt->u.owner, m->DuplicateRecords); ClearProxyRecords(m, &opt->u.owner, m->ResourceRecords); } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } // *** // *** 2. Parse Question Section and mark potential answers // *** ptr = query->data; for (i=0; ih.numQuestions; i++) // For each question... { mDNSBool QuestionNeedsMulticastResponse; int NumAnswersForThisQuestion = 0; AuthRecord *NSECAnswer = mDNSNULL; DNSQuestion pktq, *q; ptr = getQuestion(query, ptr, end, InterfaceID, &pktq); // get the question... if (!ptr) goto exit; // The only queries that *need* a multicast response are: // * Queries sent via multicast // * from port 5353 // * that don't have the kDNSQClass_UnicastResponse bit set // These queries need multicast responses because other clients will: // * suppress their own identical questions when they see these questions, and // * expire their cache records if they don't see the expected responses // For other queries, we may still choose to send the occasional multicast response anyway, // to keep our neighbours caches warm, and for ongoing conflict detection. QuestionNeedsMulticastResponse = QueryWasMulticast && !LegacyQuery && !(pktq.qclass & kDNSQClass_UnicastResponse); if (pktq.qclass & kDNSQClass_UnicastResponse) m->mDNSStats.UnicastBitInQueries++; else m->mDNSStats.NormalQueries++; // Clear the UnicastResponse flag -- don't want to confuse the rest of the code that follows later pktq.qclass &= ~kDNSQClass_UnicastResponse; // Note: We use the m->CurrentRecord mechanism here because calling ResolveSimultaneousProbe // can result in user callbacks which may change the record list and/or question list. // Also note: we just mark potential answer records here, without trying to build the // "ResponseRecords" list, because we don't want to risk user callbacks deleting records // from that list while we're in the middle of trying to build it. if (m->CurrentRecord) LogMsg("ProcessQuery ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { rr = m->CurrentRecord; m->CurrentRecord = rr->next; if (AnyTypeRecordAnswersQuestion(rr, &pktq) && (QueryWasMulticast || QueryWasLocalUnicast || rr->AllowRemoteQuery)) { m->mDNSStats.MatchingAnswersForQueries++; if (RRTypeAnswersQuestionType(&rr->resrec, pktq.qtype)) { if (rr->resrec.RecordType == kDNSRecordTypeUnique) ResolveSimultaneousProbe(m, query, end, &pktq, rr); else if (ResourceRecordIsValidAnswer(rr)) { NumAnswersForThisQuestion++; // Note: We should check here if this is a probe-type query, and if so, generate an immediate // unicast answer back to the source, because timeliness in answering probes is important. // Notes: // NR_AnswerTo pointing into query packet means "answer via immediate legacy unicast" (may *also* choose to multicast) // NR_AnswerTo == NR_AnswerUnicast means "answer via delayed unicast" (to modern querier; may promote to multicast instead) // NR_AnswerTo == NR_AnswerMulticast means "definitely answer via multicast" (can't downgrade to unicast later) // If we're not multicasting this record because the kDNSQClass_UnicastResponse bit was set, // but the multicast querier is not on a matching subnet (e.g. because of overlaid subnets on one link) // then we'll multicast it anyway (if we unicast, the receiver will ignore it because it has an apparently non-local source) if (QuestionNeedsMulticastResponse || (!FromLocalSubnet && QueryWasMulticast && !LegacyQuery)) { // We only mark this question for sending if it is at least one second since the last time we multicast it // on this interface. If it is more than a second, or LastMCInterface is different, then we may multicast it. // This is to guard against the case where someone blasts us with queries as fast as they can. if ((mDNSu32)(m->timenow - rr->LastMCTime) >= (mDNSu32)mDNSPlatformOneSecond || (rr->LastMCInterface != mDNSInterfaceMark && rr->LastMCInterface != InterfaceID)) rr->NR_AnswerTo = NR_AnswerMulticast; } else if (!rr->NR_AnswerTo) rr->NR_AnswerTo = LegacyQuery ? ptr : NR_AnswerUnicast; } } else if ((rr->resrec.RecordType & kDNSRecordTypeActiveUniqueMask) && ResourceRecordIsValidAnswer(rr)) { // If we don't have any answers for this question, but we do own another record with the same name, // then we'll want to mark it to generate an NSEC record on this interface if (!NSECAnswer) NSECAnswer = rr; } } } if (NumAnswersForThisQuestion == 0 && NSECAnswer) { NumAnswersForThisQuestion++; NSECAnswer->SendNSECNow = InterfaceID; m->NextScheduledResponse = m->timenow; } // If we couldn't answer this question, someone else might be able to, // so use random delay on response to reduce collisions if (NumAnswersForThisQuestion == 0) delayresponse = mDNSPlatformOneSecond; // Divided by 50 = 20ms if (query->h.flags.b[0] & kDNSFlag0_TC) m->mDNSStats.KnownAnswerMultiplePkts++; // We only do the following accelerated cache expiration and duplicate question suppression processing // for non-truncated multicast queries with multicast responses. // For any query generating a unicast response we don't do this because we can't assume we will see the response. // For truncated queries we don't do this because a response we're expecting might be suppressed by a subsequent // known-answer packet, and when there's packet loss we can't safely assume we'll receive *all* known-answer packets. if (QuestionNeedsMulticastResponse && !(query->h.flags.b[0] & kDNSFlag0_TC)) { #if POOF_ENABLED if (notD2D) { CacheGroup *cg = CacheGroupForName(m, pktq.qnamehash, &pktq.qname); CacheRecord *cr; // Make a list indicating which of our own cache records we expect to see updated as a result of this query // Note: Records larger than 1K are not habitually multicast, so don't expect those to be updated for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { if (SameNameCacheRecordAnswersQuestion(cr, &pktq) && cr->resrec.rdlength <= SmallRecordLimit) { if (!cr->NextInKAList && eap != &cr->NextInKAList) { *eap = cr; eap = &cr->NextInKAList; } } } } #endif // POOF_ENABLED // Check if this question is the same as any of mine. // We only do this for non-truncated queries. Right now it would be too complicated to try // to keep track of duplicate suppression state between multiple packets, especially when we // can't guarantee to receive all of the Known Answer packets that go with a particular query. for (q = m->Questions; q; q=q->next) { if (ActiveQuestion(q) && m->timenow - q->LastQTxTime > mDNSPlatformOneSecond / 4) { if (!q->InterfaceID || q->InterfaceID == InterfaceID) { if (q->NextInDQList == mDNSNULL && dqp != &q->NextInDQList) { if (q->qtype == pktq.qtype && q->qclass == pktq.qclass && q->qnamehash == pktq.qnamehash && SameDomainName(&q->qname, &pktq.qname)) { *dqp = q; dqp = &q->NextInDQList; } } } } } } } // *** // *** 3. Now we can safely build the list of marked answers // *** for (rr = m->ResourceRecords; rr; rr=rr->next) // Now build our list of potential answers if (rr->NR_AnswerTo) // If we marked the record... AddRecordToResponseList(&nrp, rr, mDNSNULL); // ... add it to the list // *** // *** 4. Add additional records // *** AddAdditionalsToResponseList(m, ResponseRecords, &nrp, InterfaceID); // *** // *** 5. Parse Answer Section and cancel any records disallowed by Known-Answer list // *** for (i=0; ih.numAnswers; i++) // For each record in the query's answer section... { // Get the record... CacheRecord *ourcacherr; ptr = GetLargeResourceRecord(m, query, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &m->rec); if (!ptr) goto exit; if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative) { // See if this Known-Answer suppresses any of our currently planned answers for (rr=ResponseRecords; rr; rr=rr->NextResponse) { if (MustSendRecord(rr) && ShouldSuppressKnownAnswer(&m->rec.r, rr)) { m->mDNSStats.KnownAnswerSuppressions++; rr->NR_AnswerTo = mDNSNULL; rr->NR_AdditionalTo = mDNSNULL; } } // See if this Known-Answer suppresses any previously scheduled answers (for multi-packet KA suppression) for (rr=m->ResourceRecords; rr; rr=rr->next) { // If we're planning to send this answer on this interface, and only on this interface, then allow KA suppression if (rr->ImmedAnswer == InterfaceID && ShouldSuppressKnownAnswer(&m->rec.r, rr)) { if (srcaddr->type == mDNSAddrType_IPv4) { if (mDNSSameIPv4Address(rr->v4Requester, srcaddr->ip.v4)) rr->v4Requester = zerov4Addr; } else if (srcaddr->type == mDNSAddrType_IPv6) { if (mDNSSameIPv6Address(rr->v6Requester, srcaddr->ip.v6)) rr->v6Requester = zerov6Addr; } if (mDNSIPv4AddressIsZero(rr->v4Requester) && mDNSIPv6AddressIsZero(rr->v6Requester)) { m->mDNSStats.KnownAnswerSuppressions++; rr->ImmedAnswer = mDNSNULL; rr->ImmedUnicast = mDNSfalse; #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES LogMsg("Suppressed after%4d: %s", m->timenow - rr->ImmedAnswerMarkTime, ARDisplayString(m, rr)); #endif } } } ourcacherr = FindIdenticalRecordInCache(m, &m->rec.r.resrec); #if POOF_ENABLED if (notD2D) { // Having built our ExpectedAnswers list from the questions in this packet, we then remove // any records that are suppressed by the Known Answer list in this packet. eap = &ExpectedAnswers; while (*eap) { CacheRecord *cr = *eap; if (cr->resrec.InterfaceID == InterfaceID && IdenticalResourceRecord(&m->rec.r.resrec, &cr->resrec)) { *eap = cr->NextInKAList; cr->NextInKAList = mDNSNULL; } else eap = &cr->NextInKAList; } } #endif // POOF_ENABLED // See if this Known-Answer is a surprise to us. If so, we shouldn't suppress our own query. if (!ourcacherr) { dqp = &DupQuestions; while (*dqp) { DNSQuestion *q = *dqp; if (CacheRecordAnswersQuestion(&m->rec.r, q)) { *dqp = q->NextInDQList; q->NextInDQList = mDNSNULL; } else dqp = &q->NextInDQList; } } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } // *** // *** 6. Cancel any additionals that were added because of now-deleted records // *** for (rr=ResponseRecords; rr; rr=rr->NextResponse) if (rr->NR_AdditionalTo && !MustSendRecord(rr->NR_AdditionalTo)) { rr->NR_AnswerTo = mDNSNULL; rr->NR_AdditionalTo = mDNSNULL; } // *** // *** 7. Mark the send flags on the records we plan to send // *** for (rr=ResponseRecords; rr; rr=rr->NextResponse) { if (rr->NR_AnswerTo) { mDNSBool SendMulticastResponse = mDNSfalse; // Send modern multicast response mDNSBool SendUnicastResponse = mDNSfalse; // Send modern unicast response (not legacy unicast response) // If it's been one TTL/4 since we multicast this, then send a multicast response // for conflict detection, etc. if ((mDNSu32)(m->timenow - rr->LastMCTime) >= (mDNSu32)TicksTTL(rr)/4) { SendMulticastResponse = mDNStrue; // If this record was marked for modern (delayed) unicast response, then mark it as promoted to // multicast response instead (don't want to end up ALSO setting SendUnicastResponse in the check below). // If this record was marked for legacy unicast response, then we mustn't change the NR_AnswerTo value. if (rr->NR_AnswerTo == NR_AnswerUnicast) { m->mDNSStats.UnicastDemotedToMulticast++; rr->NR_AnswerTo = NR_AnswerMulticast; } } // If the client insists on a multicast response, then we'd better send one if (rr->NR_AnswerTo == NR_AnswerMulticast) { m->mDNSStats.MulticastResponses++; SendMulticastResponse = mDNStrue; } else if (rr->NR_AnswerTo == NR_AnswerUnicast) { m->mDNSStats.UnicastResponses++; SendUnicastResponse = mDNStrue; } else if (rr->NR_AnswerTo) { SendLegacyResponse = mDNStrue; } if (SendMulticastResponse || SendUnicastResponse) { #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES rr->ImmedAnswerMarkTime = m->timenow; #endif m->NextScheduledResponse = m->timenow; // If we're already planning to send this on another interface, just send it on all interfaces if (rr->ImmedAnswer && rr->ImmedAnswer != InterfaceID) rr->ImmedAnswer = mDNSInterfaceMark; else { rr->ImmedAnswer = InterfaceID; // Record interface to send it on if (SendUnicastResponse) rr->ImmedUnicast = mDNStrue; if (srcaddr->type == mDNSAddrType_IPv4) { if (mDNSIPv4AddressIsZero(rr->v4Requester)) rr->v4Requester = srcaddr->ip.v4; else if (!mDNSSameIPv4Address(rr->v4Requester, srcaddr->ip.v4)) rr->v4Requester = onesIPv4Addr; } else if (srcaddr->type == mDNSAddrType_IPv6) { if (mDNSIPv6AddressIsZero(rr->v6Requester)) rr->v6Requester = srcaddr->ip.v6; else if (!mDNSSameIPv6Address(rr->v6Requester, srcaddr->ip.v6)) rr->v6Requester = onesIPv6Addr; } } } // If TC flag is set, it means we should expect that additional known answers may be coming in another packet, // so we allow roughly half a second before deciding to reply (we've observed inter-packet delays of 100-200ms on 802.11) // else, if record is a shared one, spread responses over 100ms to avoid implosion of simultaneous responses // else, for a simple unique record reply, we can reply immediately; no need for delay if (query->h.flags.b[0] & kDNSFlag0_TC) delayresponse = mDNSPlatformOneSecond * 20; // Divided by 50 = 400ms else if (rr->resrec.RecordType == kDNSRecordTypeShared) delayresponse = mDNSPlatformOneSecond; // Divided by 50 = 20ms } else if (rr->NR_AdditionalTo && rr->NR_AdditionalTo->NR_AnswerTo == NR_AnswerMulticast) { // Since additional records are an optimization anyway, we only ever send them on one interface at a time // If two clients on different interfaces do queries that invoke the same optional additional answer, // then the earlier client is out of luck rr->ImmedAdditional = InterfaceID; // No need to set m->NextScheduledResponse here // We'll send these additional records when we send them, or not, as the case may be } } // *** // *** 8. If we think other machines are likely to answer these questions, set our packet suppression timer // *** if (delayresponse && (!m->SuppressSending || (m->SuppressSending - m->timenow) < (delayresponse + 49) / 50)) { #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES mDNSs32 oldss = m->SuppressSending; if (oldss && delayresponse) LogMsg("Current SuppressSending delay%5ld; require%5ld", m->SuppressSending - m->timenow, (delayresponse + 49) / 50); #endif // Pick a random delay: // We start with the base delay chosen above (typically either 1 second or 20 seconds), // and add a random value in the range 0-5 seconds (making 1-6 seconds or 20-25 seconds). // This is an integer value, with resolution determined by the platform clock rate. // We then divide that by 50 to get the delay value in ticks. We defer the division until last // to get better results on platforms with coarse clock granularity (e.g. ten ticks per second). // The +49 before dividing is to ensure we round up, not down, to ensure that even // on platforms where the native clock rate is less than fifty ticks per second, // we still guarantee that the final calculated delay is at least one platform tick. // We want to make sure we don't ever allow the delay to be zero ticks, // because if that happens we'll fail the Bonjour Conformance Test. // Our final computed delay is 20-120ms for normal delayed replies, // or 400-500ms in the case of multi-packet known-answer lists. m->SuppressSending = m->timenow + (delayresponse + (mDNSs32)mDNSRandom((mDNSu32)mDNSPlatformOneSecond*5) + 49) / 50; if (m->SuppressSending == 0) m->SuppressSending = 1; #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES if (oldss && delayresponse) LogMsg("Set SuppressSending to %5ld", m->SuppressSending - m->timenow); #endif } // *** // *** 9. If query is from a legacy client, or from a new client requesting a unicast reply, then generate a unicast response too // *** if (SendLegacyResponse) responseptr = GenerateUnicastResponse(query, end, InterfaceID, LegacyQuery, response, ResponseRecords); exit: m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it // *** // *** 10. Finally, clear our link chains ready for use next time // *** while (ResponseRecords) { rr = ResponseRecords; ResponseRecords = rr->NextResponse; rr->NextResponse = mDNSNULL; rr->NR_AnswerTo = mDNSNULL; rr->NR_AdditionalTo = mDNSNULL; } #if POOF_ENABLED while (ExpectedAnswers && notD2D) { CacheRecord *cr = ExpectedAnswers; ExpectedAnswers = cr->NextInKAList; cr->NextInKAList = mDNSNULL; // For non-truncated queries, we can definitively say that we should expect // to be seeing a response for any records still left in the ExpectedAnswers list if (!(query->h.flags.b[0] & kDNSFlag0_TC)) if (cr->UnansweredQueries == 0 || m->timenow - cr->LastUnansweredTime >= mDNSPlatformOneSecond * 3/4) { cr->UnansweredQueries++; cr->LastUnansweredTime = m->timenow; if (cr->UnansweredQueries > 1) debugf("ProcessQuery: UnansweredQueries %lu %s", cr->UnansweredQueries, CRDisplayString(m, cr)); SetNextCacheCheckTimeForRecord(m, cr); } // If we've seen multiple unanswered queries for this record, // then mark it to expire in five seconds if we don't get a response by then. if (cr->UnansweredQueries >= MaxUnansweredQueries) { // Only show debugging message if this record was not about to expire anyway if (RRExpireTime(cr) - m->timenow > (mDNSs32) kDefaultReconfirmTimeForNoAnswer * 4 / 3 + mDNSPlatformOneSecond) LogInfo("ProcessQuery: UnansweredQueries %lu interface %lu TTL %lu mDNS_Reconfirm() for %s", cr->UnansweredQueries, InterfaceID, (RRExpireTime(cr) - m->timenow + mDNSPlatformOneSecond-1) / mDNSPlatformOneSecond, CRDisplayString(m, cr)); m->mDNSStats.PoofCacheDeletions++; mDNS_Reconfirm_internal(m, cr, kDefaultReconfirmTimeForNoAnswer); } } #endif // POOF_ENABLED while (DupQuestions) { DNSQuestion *q = DupQuestions; DupQuestions = q->NextInDQList; q->NextInDQList = mDNSNULL; RecordDupSuppressInfo(q->DupSuppress, m->timenow, InterfaceID, srcaddr->type); debugf("ProcessQuery: Recorded DSI for %##s (%s) on %p/%s", q->qname.c, DNSTypeName(q->qtype), InterfaceID, srcaddr->type == mDNSAddrType_IPv4 ? "v4" : "v6"); } return(responseptr); } mDNSlocal void mDNSCoreReceiveQuery(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, mDNSIPPort dstport, const mDNSInterfaceID InterfaceID) { mDNSu8 *responseend = mDNSNULL; mDNSBool QueryWasLocalUnicast = srcaddr && dstaddr && !mDNSAddrIsDNSMulticast(dstaddr) && mDNS_AddressIsLocalSubnet(m, InterfaceID, srcaddr); if (!dstaddr || (!InterfaceID && mDNSAddrIsDNSMulticast(dstaddr))) { const char *const reason = !dstaddr ? "Received over TCP connection" : "Multicast, but no InterfaceID"; LogMsg("Ignoring Query from %#-15a:%-5d to %#-15a:%-5d on 0x%p with " "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes (%s)", srcaddr, mDNSVal16(srcport), dstaddr, mDNSVal16(dstport), InterfaceID, msg->h.numQuestions, msg->h.numQuestions == 1 ? ", " : "s,", msg->h.numAnswers, msg->h.numAnswers == 1 ? ", " : "s,", msg->h.numAuthorities, msg->h.numAuthorities == 1 ? "y, " : "ies,", msg->h.numAdditionals, msg->h.numAdditionals == 1 ? " " : "s", end - msg->data, reason); return; } verbosedebugf("Received Query from %#-15a:%-5d to %#-15a:%-5d on 0x%p with " "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes", srcaddr, mDNSVal16(srcport), dstaddr, mDNSVal16(dstport), InterfaceID, msg->h.numQuestions, msg->h.numQuestions == 1 ? ", " : "s,", msg->h.numAnswers, msg->h.numAnswers == 1 ? ", " : "s,", msg->h.numAuthorities, msg->h.numAuthorities == 1 ? "y, " : "ies,", msg->h.numAdditionals, msg->h.numAdditionals == 1 ? " " : "s", end - msg->data); responseend = ProcessQuery(m, msg, end, srcaddr, InterfaceID, !mDNSSameIPPort(srcport, MulticastDNSPort), mDNSAddrIsDNSMulticast(dstaddr), QueryWasLocalUnicast, &m->omsg); if (responseend) // If responseend is non-null, that means we built a unicast response packet { debugf("Unicast Response: %d Question%s, %d Answer%s, %d Additional%s to %#-15a:%d on %p/%ld", m->omsg.h.numQuestions, m->omsg.h.numQuestions == 1 ? "" : "s", m->omsg.h.numAnswers, m->omsg.h.numAnswers == 1 ? "" : "s", m->omsg.h.numAdditionals, m->omsg.h.numAdditionals == 1 ? "" : "s", srcaddr, mDNSVal16(srcport), InterfaceID, srcaddr->type); mDNSSendDNSMessage(m, &m->omsg, responseend, InterfaceID, mDNSNULL, mDNSNULL, srcaddr, srcport, mDNSNULL, mDNSfalse); } } #if 0 mDNSlocal mDNSBool TrustedSource(const mDNS *const m, const mDNSAddr *const srcaddr) { DNSServer *s; (void)m; // Unused (void)srcaddr; // Unused for (s = m->DNSServers; s; s = s->next) if (mDNSSameAddress(srcaddr, &s->addr)) return(mDNStrue); return(mDNSfalse); } #endif struct UDPSocket_struct { mDNSIPPort port; // MUST BE FIRST FIELD -- mDNSCoreReceive expects every UDPSocket_struct to begin with mDNSIPPort port }; mDNSlocal DNSQuestion *ExpectingUnicastResponseForQuestion(const mDNS *const m, const mDNSIPPort port, const mDNSOpaque16 id, const DNSQuestion *const question, mDNSBool tcp) { DNSQuestion *q; for (q = m->Questions; q; q=q->next) { if (!tcp && !q->LocalSocket) continue; if (mDNSSameIPPort(tcp ? q->tcpSrcPort : q->LocalSocket->port, port) && q->qtype == question->qtype && q->qclass == question->qclass && q->qnamehash == question->qnamehash && SameDomainName(&q->qname, &question->qname)) { if (mDNSSameOpaque16(q->TargetQID, id)) return(q); else { return(mDNSNULL); } } } return(mDNSNULL); } // This function is called when we receive a unicast response. This could be the case of a unicast response from the // DNS server or a response to the QU query. Hence, the cache record's InterfaceId can be both NULL or non-NULL (QU case) mDNSlocal DNSQuestion *ExpectingUnicastResponseForRecord(mDNS *const m, const mDNSAddr *const srcaddr, const mDNSBool SrcLocal, const mDNSIPPort port, const mDNSOpaque16 id, const CacheRecord *const rr, mDNSBool tcp) { DNSQuestion *q; (void)id; for (q = m->Questions; q; q=q->next) { if (!q->DuplicateOf && ResourceRecordAnswersUnicastResponse(&rr->resrec, q)) { if (!mDNSOpaque16IsZero(q->TargetQID)) { debugf("ExpectingUnicastResponseForRecord msg->h.id %d q->TargetQID %d for %s", mDNSVal16(id), mDNSVal16(q->TargetQID), CRDisplayString(m, rr)); if (mDNSSameOpaque16(q->TargetQID, id)) { mDNSIPPort srcp; if (!tcp) { if (q->LocalSocket) srcp = q->LocalSocket->port; else srcp = zeroIPPort; } else { srcp = q->tcpSrcPort; } if (mDNSSameIPPort(srcp, port)) return(q); // if (mDNSSameAddress(srcaddr, &q->Target)) return(mDNStrue); // if (q->LongLived && mDNSSameAddress(srcaddr, &q->servAddr)) return(mDNStrue); Shouldn't need this now that we have LLQType checking // if (TrustedSource(m, srcaddr)) return(mDNStrue); LogInfo("WARNING: Ignoring suspect uDNS response for %##s (%s) from %#a:%d %s", q->qname.c, DNSTypeName(q->qtype), srcaddr, mDNSVal16(port), CRDisplayString(m, rr)); return(mDNSNULL); } } else { if (SrcLocal && q->ExpectUnicastResp && (mDNSu32)(m->timenow - q->ExpectUnicastResp) < (mDNSu32)(mDNSPlatformOneSecond*2)) return(q); } } } return(mDNSNULL); } // Certain data types need more space for in-memory storage than their in-packet rdlength would imply // Currently this applies only to rdata types containing more than one domainname, // or types where the domainname is not the last item in the structure. mDNSlocal mDNSu16 GetRDLengthMem(const ResourceRecord *const rr) { switch (rr->rrtype) { case kDNSType_SOA: return sizeof(rdataSOA); case kDNSType_RP: return sizeof(rdataRP); case kDNSType_PX: return sizeof(rdataPX); default: return rr->rdlength; } } mDNSexport CacheRecord *CreateNewCacheEntry(mDNS *const m, const mDNSu32 slot, CacheGroup *cg, mDNSs32 delay, mDNSBool Add, const mDNSAddr *sourceAddress) { CacheRecord *rr = mDNSNULL; mDNSu16 RDLength = GetRDLengthMem(&m->rec.r.resrec); if (!m->rec.r.resrec.InterfaceID) debugf("CreateNewCacheEntry %s", CRDisplayString(m, &m->rec.r)); //if (RDLength > InlineCacheRDSize) // LogInfo("Rdata len %4d > InlineCacheRDSize %d %s", RDLength, InlineCacheRDSize, CRDisplayString(m, &m->rec.r)); if (!cg) cg = GetCacheGroup(m, slot, &m->rec.r.resrec); // If we don't have a CacheGroup for this name, make one now if (cg) rr = GetCacheRecord(m, cg, RDLength); // Make a cache record, being careful not to recycle cg if (!rr) NoCacheAnswer(m, &m->rec.r); else { RData *saveptr = rr->resrec.rdata; // Save the rr->resrec.rdata pointer *rr = m->rec.r; // Block copy the CacheRecord object #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_retain_null_safe(rr->resrec.dnsservice); #endif rr->resrec.rdata = saveptr; // Restore rr->resrec.rdata after the structure assignment rr->resrec.name = cg->name; // And set rr->resrec.name to point into our CacheGroup header rr->resrec.mortality = Mortality_Mortal; #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) rr->resrec.dnssec_result = dnssec_indeterminate; // Set the DNSSEC validation result of a record as "indeterminate" by default. #endif rr->DelayDelivery = delay; // If this is an oversized record with external storage allocated, copy rdata to external storage if (rr->resrec.rdata == (RData*)&rr->smallrdatastorage && RDLength > InlineCacheRDSize) LogMsg("rr->resrec.rdata == &rr->rdatastorage but length > InlineCacheRDSize %##s", m->rec.r.resrec.name->c); else if (rr->resrec.rdata != (RData*)&rr->smallrdatastorage && RDLength <= InlineCacheRDSize) LogMsg("rr->resrec.rdata != &rr->rdatastorage but length <= InlineCacheRDSize %##s", m->rec.r.resrec.name->c); if (RDLength > InlineCacheRDSize) mDNSPlatformMemCopy(rr->resrec.rdata, m->rec.r.resrec.rdata, sizeofRDataHeader + RDLength); rr->next = mDNSNULL; // Clear 'next' pointer rr->soa = mDNSNULL; if (sourceAddress) rr->sourceAddress = *sourceAddress; if (!rr->resrec.InterfaceID) { m->rrcache_totalused_unicast += rr->resrec.rdlength; } #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) if (rr != mDNSNULL) { rr->denial_of_existence_records = mDNSNULL; } #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) if (Add) { *(cg->rrcache_tail) = rr; // Append this record to tail of cache slot list cg->rrcache_tail = &(rr->next); // Advance tail pointer CacheRecordAdd(m, rr); // CacheRecordAdd calls SetNextCacheCheckTimeForRecord(m, rr); for us } else { // Can't use the "cg->name" if we are not adding to the cache as the // CacheGroup may be released anytime if it is empty domainname *name = (domainname *) mDNSPlatformMemAllocate(DomainNameLength(cg->name)); if (name) { AssignDomainName(name, cg->name); rr->resrec.name = name; } else { ReleaseCacheRecord(m, rr); NoCacheAnswer(m, &m->rec.r); rr = mDNSNULL; } } } return(rr); } mDNSlocal void RefreshCacheRecordCacheGroupOrder(CacheGroup *cg, CacheRecord *cr) { // Move the cache record to the tail of the cache group to maintain a fresh ordering if (cg->rrcache_tail != &cr->next) // If not already at the tail { CacheRecord **rp; for (rp = &cg->members; *rp; rp = &(*rp)->next) { if (*rp == cr) // This item points to this record { *rp = cr->next; // Remove this record break; } } cr->next = mDNSNULL; // This record is now last *(cg->rrcache_tail) = cr; // Append this record to tail of cache group cg->rrcache_tail = &(cr->next); // Advance tail pointer } } mDNSlocal void RefreshCacheRecord(mDNS *const m, CacheRecord *rr, mDNSu32 ttl) { rr->TimeRcvd = m->timenow; rr->resrec.rroriginalttl = ttl; rr->UnansweredQueries = 0; if (rr->resrec.mortality != Mortality_Mortal) rr->resrec.mortality = Mortality_Immortal; SetNextCacheCheckTimeForRecord(m, rr); } mDNSexport void GrantCacheExtensions(mDNS *const m, DNSQuestion *q, mDNSu32 lease) { CacheRecord *rr; CacheGroup *cg = CacheGroupForName(m, q->qnamehash, &q->qname); for (rr = cg ? cg->members : mDNSNULL; rr; rr=rr->next) if (rr->CRActiveQuestion == q) { //LogInfo("GrantCacheExtensions: new lease %d / %s", lease, CRDisplayString(m, rr)); RefreshCacheRecord(m, rr, lease); } } mDNSlocal mDNSu32 GetEffectiveTTL(const uDNS_LLQType LLQType, mDNSu32 ttl) // TTL in seconds { if (LLQType == uDNS_LLQ_Entire) ttl = kLLQ_DefLease; else if (LLQType == uDNS_LLQ_Events) { // If the TTL is -1 for uDNS LLQ event packet, that means "remove" if (ttl == 0xFFFFFFFF) ttl = 0; else ttl = kLLQ_DefLease; } else // else not LLQ (standard uDNS response) { // The TTL is already capped to a maximum value in GetLargeResourceRecord, but just to be extra safe we // also do this check here to make sure we can't get overflow below when we add a quarter to the TTL if (ttl > 0x60000000UL / mDNSPlatformOneSecond) ttl = 0x60000000UL / mDNSPlatformOneSecond; ttl = RRAdjustTTL(ttl); // For mDNS, TTL zero means "delete this record" // For uDNS, TTL zero means: this data is true at this moment, but don't cache it. // For the sake of network efficiency, we impose a minimum effective TTL of 15 seconds. // This means that we'll do our 80, 85, 90, 95% queries at 12.00, 12.75, 13.50, 14.25 seconds // respectively, and then if we get no response, delete the record from the cache at 15 seconds. // This gives the server up to three seconds to respond between when we send our 80% query at 12 seconds // and when we delete the record at 15 seconds. Allowing cache lifetimes less than 15 seconds would // (with the current code) result in the server having even less than three seconds to respond // before we deleted the record and reported a "remove" event to any active questions. // Furthermore, with the current code, if we were to allow a TTL of less than 2 seconds // then things really break (e.g. we end up making a negative cache entry). // In the future we may want to revisit this and consider properly supporting non-cached (TTL=0) uDNS answers. if (ttl < 15) ttl = 15; } return ttl; } // When the response does not match the question directly, we still want to cache them sometimes. The current response is // in m->rec. mDNSlocal mDNSBool IsResponseAcceptable(mDNS *const m, const CacheRecord *crlist) { CacheRecord *const newcr = &m->rec.r; ResourceRecord *rr = &newcr->resrec; const CacheRecord *cr; for (cr = crlist; cr != (CacheRecord*)1; cr = cr->NextInCFList) { domainname *target = GetRRDomainNameTarget(&cr->resrec); // When we issue a query for A record, the response might contain both a CNAME and A records. Only the CNAME would // match the question and we already created a cache entry in the previous pass of this loop. Now when we process // the A record, it does not match the question because the record name here is the CNAME. Hence we try to // match with the previous records to make it an AcceptableResponse. We have to be careful about setting the // DNSServer value that we got in the previous pass. This can happen for other record types like SRV also. if (target && cr->resrec.rdatahash == rr->namehash && SameDomainName(target, rr->name)) { LogDebug("IsResponseAcceptable: Found a matching entry for %##s in the CacheFlushRecords %s", rr->name->c, CRDisplayString(m, cr)); return (mDNStrue); } } return mDNSfalse; } mDNSlocal void mDNSCoreReceiveNoUnicastAnswers(mDNS *const m, const DNSMessage *const response, const mDNSu8 *end, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID, #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) const mdns_querier_t querier, const mdns_dns_service_t uDNSService, #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) denial_of_existence_records_t **denial_of_existence_records_ptr, #endif const uDNS_LLQType LLQType) { int i; const mDNSu8 *ptr = response->data; CacheRecord *SOARecord = mDNSNULL; for (i = 0; i < response->h.numQuestions && ptr && ptr < end; i++) { DNSQuestion q; ptr = getQuestion(response, ptr, end, InterfaceID, &q); if (ptr) { DNSQuestion *qptr; CacheRecord *cr, *neg = mDNSNULL; CacheGroup *cg; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (querier) { qptr = Querier_GetDNSQuestion(querier); } else #endif { qptr = ExpectingUnicastResponseForQuestion(m, dstport, response->h.id, &q, !dstaddr); if (!qptr) { continue; } } cg = CacheGroupForName(m, q.qnamehash, &q.qname); for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { mDNSBool isAnswer; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (querier) { isAnswer = (cr->resrec.dnsservice == uDNSService) && Querier_SameNameCacheRecordIsAnswer(cr, querier); } else #endif { isAnswer = SameNameCacheRecordAnswersQuestion(cr, qptr); } if (isAnswer) { // 1. If we got a fresh answer to this query, then don't need to generate a negative entry if (RRExpireTime(cr) - m->timenow > 0) break; // 2. If we already had a negative entry, keep track of it so we can resurrect it instead of creating a new one if (cr->resrec.RecordType == kDNSRecordTypePacketNegative) neg = cr; else if (cr->resrec.mortality == Mortality_Ghost) { // 3. If the existing entry is expired, mark it to be purged LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] mDNSCoreReceiveNoUnicastAnswers: Removing expired record" PRI_S, q.request_id, mDNSVal16(q.TargetQID), CRDisplayString(m, cr)); mDNS_PurgeCacheResourceRecord(m, cr); } } } // When we're doing parallel unicast and multicast queries for dot-local names (for supporting Microsoft // Active Directory sites) we don't want to waste memory making negative cache entries for all the unicast answers. // Otherwise we just fill up our cache with negative entries for just about every single multicast name we ever look up // (since the Microsoft Active Directory server is going to assert that pretty much every single multicast name doesn't exist). // This is not only a waste of memory, but there's also the problem of those negative entries confusing us later -- e.g. we // suppress sending our mDNS query packet because we think we already have a valid (negative) answer to that query in our cache. // The one exception is that we *DO* want to make a negative cache entry for "local. SOA", for the (common) case where we're // *not* on a Microsoft Active Directory network, and there is no authoritative server for "local". Note that this is not // in conflict with the mDNS spec, because that spec says, "Multicast DNS Zones have no SOA record," so it's okay to cache // negative answers for "local. SOA" from a uDNS server, because the mDNS spec already says that such records do not exist :-) // // By suppressing negative responses, it might take longer to timeout a .local question as it might be expecting a // response e.g., we deliver a positive "A" response and suppress negative "AAAA" response and the upper layer may // be waiting longer to get the AAAA response before returning the "A" response to the application. To handle this // case without creating the negative cache entries, we generate a negative response and let the layer above us // do the appropriate thing. This negative response is also needed for appending new search domains. if (!InterfaceID && q.qtype != kDNSType_SOA && IsLocalDomain(&q.qname)) { if (!cr) { if (qptr) { const mDNSBool noData = ((response->h.flags.b[1] & kDNSFlag1_RC_Mask) == kDNSFlag1_RC_NoErr) ? mDNStrue : mDNSfalse; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] mDNSCoreReceiveNoUnicastAnswers: Generate negative response for " PRI_DM_NAME " (" PUB_S ")", q.request_id, mDNSVal16(q.TargetQID), DM_NAME_PARAM(&q.qname), DNSTypeName(q.qtype)); m->CurrentQuestion = qptr; // We are not creating a cache record in this case, we need to pass back // the error we got so that the proxy code can return the right one to // the application if (qptr->ProxyQuestion) qptr->responseFlags = response->h.flags; GenerateNegativeResponseEx(m, mDNSInterface_Any, QC_forceresponse, noData); m->CurrentQuestion = mDNSNULL; } } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] mDNSCoreReceiveNoUnicastAnswers: Skipping check and not creating a negative cache entry for " PRI_DM_NAME " (" PUB_S ")", q.request_id, mDNSVal16(q.TargetQID), DM_NAME_PARAM(&q.qname), DNSTypeName(q.qtype)); } } else { if (!cr) { // We start off assuming a negative caching TTL of 60 seconds // but then look to see if we can find an SOA authority record to tell us a better value we should be using mDNSu32 negttl = 60; int repeat = 0; const domainname *name = &q.qname; mDNSu32 hash = q.qnamehash; // Special case for our special Microsoft Active Directory "local SOA" check. // Some cheap home gateways don't include an SOA record in the authority section when // they send negative responses, so we don't know how long to cache the negative result. // Because we don't want to keep hitting the root name servers with our query to find // if we're on a network using Microsoft Active Directory using "local" as a private // internal top-level domain, we make sure to cache the negative result for at least one day. if (q.qtype == kDNSType_SOA && SameDomainName(&q.qname, &localdomain)) negttl = 60 * 60 * 24; // If we're going to make (or update) a negative entry, then look for the appropriate TTL from the SOA record if (response->h.numAuthorities && (ptr = LocateAuthorities(response, end)) != mDNSNULL) { ptr = GetLargeResourceRecord(m, response, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &m->rec); if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_SOA) { CacheGroup *cgSOA = CacheGroupForRecord(m, &m->rec.r.resrec); const rdataSOA *const soa = (const rdataSOA *)m->rec.r.resrec.rdata->u.data; mDNSu32 ttl_s = soa->min; // We use the lesser of the SOA.MIN field and the SOA record's TTL, *except* // for the SOA record for ".", where the record is reported as non-cacheable // (TTL zero) for some reason, so in this case we just take the SOA record's TTL as-is if (ttl_s > m->rec.r.resrec.rroriginalttl && m->rec.r.resrec.name->c[0]) ttl_s = m->rec.r.resrec.rroriginalttl; if (negttl < ttl_s) negttl = ttl_s; // Create the SOA record as we may have to return this to the questions // that we are acting as a proxy for currently or in the future. SOARecord = CreateNewCacheEntry(m, HashSlotFromNameHash(m->rec.r.resrec.namehash), cgSOA, 1, mDNSfalse, mDNSNULL); // Special check for SOA queries: If we queried for a.b.c.d.com, and got no answer, // with an Authority Section SOA record for d.com, then this is a hint that the authority // is d.com, and consequently SOA records b.c.d.com and c.d.com don't exist either. // To do this we set the repeat count so the while loop below will make a series of negative cache entries for us // // For ProxyQuestions, we don't do this as we need to create additional SOA records to cache them // along with the negative cache record. For simplicity, we don't create the additional records. if ((!qptr || !qptr->ProxyQuestion) && (q.qtype == kDNSType_SOA)) { int qcount = CountLabels(&q.qname); int scount = CountLabels(m->rec.r.resrec.name); if (qcount - 1 > scount) if (SameDomainName(SkipLeadingLabels(&q.qname, qcount - scount), m->rec.r.resrec.name)) repeat = qcount - 1 - scount; } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } // If we already had a negative entry in the cache, then we double our existing negative TTL. This is to avoid // the case where the record doesn't exist (e.g. particularly for things like our lb._dns-sd._udp. query), // and the server returns no SOA record (or an SOA record with a small MIN TTL) so we assume a TTL // of 60 seconds, and we end up polling the server every minute for a record that doesn't exist. // With this fix in place, when this happens, we double the effective TTL each time (up to one hour), // so that we back off our polling rate and don't keep hitting the server continually. if (neg) { if (negttl < neg->resrec.rroriginalttl * 2) negttl = neg->resrec.rroriginalttl * 2; if (negttl > 3600) negttl = 3600; } negttl = GetEffectiveTTL(LLQType, negttl); // Add 25% grace period if necessary // If we already had a negative cache entry just update it, else make one or more new negative cache entries. if (neg) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] mDNSCoreReceiveNoUnicastAnswers: Renewing negative TTL from %d to %d " PRI_S, q.request_id, mDNSVal16(q.TargetQID), neg->resrec.rroriginalttl, negttl, CRDisplayString(m, neg)); RefreshCacheRecord(m, neg, negttl); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // replace the old records with the new ones // If qptr is NULL, it means the question is no longer active, and we do not process the record // for DNSSEC. if ((qptr != mDNSNULL) && qptr->DNSSECStatus.enable_dnssec) { update_denial_records_in_cache_record(neg, denial_of_existence_records_ptr); } #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // When we created the cache for the first time and answered the question, the question's // interval was set to MaxQuestionInterval. If the cache is about to expire and we are resending // the queries, the interval should still be at MaxQuestionInterval. If the query is being // restarted (setting it to InitialQuestionInterval) for other reasons e.g., wakeup, // we should reset its question interval here to MaxQuestionInterval. if (qptr) { ResetQuestionState(m, qptr); } if (SOARecord) { if (neg->soa) ReleaseCacheRecord(m, neg->soa); neg->soa = SOARecord; SOARecord = mDNSNULL; } } else while (1) { CacheRecord *negcr; debugf("mDNSCoreReceiveNoUnicastAnswers making negative cache entry TTL %d for %##s (%s)", negttl, name->c, DNSTypeName(q.qtype)); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) MakeNegativeCacheRecord(m, &m->rec.r, name, hash, q.qtype, q.qclass, negttl, mDNSInterface_Any, uDNSService); #else MakeNegativeCacheRecord(m, &m->rec.r, name, hash, q.qtype, q.qclass, negttl, mDNSInterface_Any, qptr->qDNSServer); #endif m->rec.r.responseFlags = response->h.flags; // We create SOA records above which might create new cache groups. Earlier // in the function we looked up the cache group for the name and it could have // been NULL. If we pass NULL cg to new cache entries that we create below, // it will create additional cache groups for the same name. To avoid that, // look up the cache group again to re-initialize cg again. cg = CacheGroupForName(m, hash, name); // Need to add with a delay so that we can tag the SOA record negcr = CreateNewCacheEntry(m, HashSlotFromNameHash(hash), cg, 1, mDNStrue, mDNSNULL); if (negcr) { #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // If qptr is NULL, it means the question is no longer active, and we do not process the // record for DNSSEC. if (qptr != mDNSNULL && qptr->DNSSECStatus.enable_dnssec) { update_denial_records_in_cache_record(negcr, denial_of_existence_records_ptr); } #endif negcr->DelayDelivery = 0; if (SOARecord) { if (negcr->soa) ReleaseCacheRecord(m, negcr->soa); negcr->soa = SOARecord; SOARecord = mDNSNULL; } CacheRecordDeferredAdd(m, negcr); } m->rec.r.responseFlags = zeroID; m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it if (!repeat) break; repeat--; name = (const domainname *)(name->c + 1 + name->c[0]); hash = DomainNameHashValue(name); } } } } } if (SOARecord) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNSCoreReceiveNoUnicastAnswers: SOARecord not used"); ReleaseCacheRecord(m, SOARecord); } } mDNSlocal void mDNSCorePrintStoredProxyRecords(mDNS *const m) { AuthRecord *rrPtr = mDNSNULL; if (!m->SPSRRSet) return; LogSPS("Stored Proxy records :"); for (rrPtr = m->SPSRRSet; rrPtr; rrPtr = rrPtr->next) { LogSPS("%s", ARDisplayString(m, rrPtr)); } } mDNSlocal mDNSBool mDNSCoreRegisteredProxyRecord(mDNS *const m, AuthRecord *rr) { AuthRecord *rrPtr = mDNSNULL; for (rrPtr = m->SPSRRSet; rrPtr; rrPtr = rrPtr->next) { if (IdenticalResourceRecord(&rrPtr->resrec, &rr->resrec)) { LogSPS("mDNSCoreRegisteredProxyRecord: Ignoring packet registered with sleep proxy : %s ", ARDisplayString(m, rr)); return mDNStrue; } } mDNSCorePrintStoredProxyRecords(m); return mDNSfalse; } mDNSexport CacheRecord* mDNSCoreReceiveCacheCheck(mDNS *const m, const DNSMessage *const response, uDNS_LLQType LLQType, const mDNSu32 slot, CacheGroup *cg, CacheRecord ***cfp, mDNSInterfaceID InterfaceID) { CacheRecord *cr; CacheRecord **cflocal = *cfp; for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { mDNSBool match; // Resource record received via unicast, the resGroupID should match ? if (!InterfaceID) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) match = (cr->resrec.dnsservice == m->rec.r.resrec.dnsservice) ? mDNStrue : mDNSfalse; #else const mDNSu32 id1 = (cr->resrec.rDNSServer ? cr->resrec.rDNSServer->resGroupID : 0); const mDNSu32 id2 = (m->rec.r.resrec.rDNSServer ? m->rec.r.resrec.rDNSServer->resGroupID : 0); match = (id1 == id2); #endif } else match = (cr->resrec.InterfaceID == InterfaceID); // If we found this exact resource record, refresh its TTL if (match) { if (IdenticalSameNameRecord(&m->rec.r.resrec, &cr->resrec)) { if (m->rec.r.resrec.rdlength > InlineCacheRDSize) verbosedebugf("mDNSCoreReceiveCacheCheck: Found record size %5d interface %p already in cache: %s", m->rec.r.resrec.rdlength, InterfaceID, CRDisplayString(m, &m->rec.r)); if (m->rec.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) { // If this packet record has the kDNSClass_UniqueRRSet flag set, then add it to our cache flushing list if (cr->NextInCFList == mDNSNULL && *cfp != &cr->NextInCFList && LLQType != uDNS_LLQ_Events) { *cflocal = cr; cflocal = &cr->NextInCFList; *cflocal = (CacheRecord*)1; *cfp = &cr->NextInCFList; } // If this packet record is marked unique, and our previous cached copy was not, then fix it if (!(cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask)) { DNSQuestion *q; for (q = m->Questions; q; q=q->next) { if (CacheRecordAnswersQuestion(cr, q)) q->UniqueAnswers++; } cr->resrec.RecordType = m->rec.r.resrec.RecordType; } } if (!SameRDataBody(&m->rec.r.resrec, &cr->resrec.rdata->u, SameDomainNameCS)) { // If the rdata of the packet record differs in name capitalization from the record in our cache // then mDNSPlatformMemSame will detect this. In this case, throw the old record away, so that clients get // a 'remove' event for the record with the old capitalization, and then an 'add' event for the new one. // mDNS -F returns the same domain multiple times with different casing cr->resrec.rroriginalttl = 0; cr->TimeRcvd = m->timenow; cr->UnansweredQueries = MaxUnansweredQueries; SetNextCacheCheckTimeForRecord(m, cr); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNSCoreReceiveCacheCheck: Discarding due to domainname case change old: " PRI_S, CRDisplayString(m, cr)); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNSCoreReceiveCacheCheck: Discarding due to domainname case change new: " PRI_S, CRDisplayString(m, &m->rec.r)); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNSCoreReceiveCacheCheck: Discarding due to domainname case change in %d slot %3d in %d %d", NextCacheCheckEvent(cr) - m->timenow, slot, m->rrcache_nextcheck[slot] - m->timenow, m->NextCacheCheck - m->timenow); // DO NOT break out here -- we want to continue as if we never found it } else if (m->rec.r.resrec.rroriginalttl > 0) { DNSQuestion *q; m->mDNSStats.CacheRefreshed++; if ((cr->resrec.mortality == Mortality_Ghost) && !cr->DelayDelivery) { cr->DelayDelivery = NonZeroTime(m->timenow); debugf("mDNSCoreReceiveCacheCheck: Reset DelayDelivery for mortalityExpired EXP:%d RR %s", m->timenow - RRExpireTime(cr), CRDisplayString(m, cr)); } if (cr->resrec.rroriginalttl == 0) debugf("uDNS rescuing %s", CRDisplayString(m, cr)); RefreshCacheRecord(m, cr, m->rec.r.resrec.rroriginalttl); // RefreshCacheRecordCacheGroupOrder will modify the cache group member list that is currently being iterated over in this for-loop. // It is safe to call because the else-if body will unconditionally break out of the for-loop now that it has found the entry to update. RefreshCacheRecordCacheGroupOrder(cg, cr); cr->responseFlags = response->h.flags; // If we may have NSEC records returned with the answer (which we don't know yet as it // has not been processed), we need to cache them along with the first cache // record in the list that answers the question so that it can be used for validation // later. The "type" check below is to make sure that we cache on the cache record // that would answer the question. It is possible that we might cache additional things // e.g., MX question might cache A records also, and we want to cache the NSEC on // the record that answers the question. if (!InterfaceID) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNSCoreReceiveCacheCheck: rescuing RR " PRI_S, CRDisplayString(m, cr)); } // We have to reset the question interval to MaxQuestionInterval so that we don't keep // polling the network once we get a valid response back. For the first time when a new // cache entry is created, AnswerCurrentQuestionWithResourceRecord does that. // Subsequently, if we reissue questions from within the mDNSResponder e.g., DNS server // configuration changed, without flushing the cache, we reset the question interval here. // Currently, we do this for for both multicast and unicast questions as long as the record // type is unique. For unicast, resource record is always unique and for multicast it is // true for records like A etc. but not for PTR. if (cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) { for (q = m->Questions; q; q=q->next) { if (!q->DuplicateOf && !q->LongLived && ActiveQuestion(q) && CacheRecordAnswersQuestion(cr, q)) { ResetQuestionState(m, q); debugf("mDNSCoreReceiveCacheCheck: Set MaxQuestionInterval for %p %##s (%s)", q, q->qname.c, DNSTypeName(q->qtype)); break; // Why break here? Aren't there other questions we might want to look at?-- SC July 2010 } } } break; // Check usage of RefreshCacheRecordCacheGroupOrder before removing (See note above) } else { // If the packet TTL is zero, that means we're deleting this record. // To give other hosts on the network a chance to protest, we push the deletion // out one second into the future. Also, we set UnansweredQueries to MaxUnansweredQueries. // Otherwise, we'll do final queries for this record at 80% and 90% of its apparent // lifetime (800ms and 900ms from now) which is a pointless waste of network bandwidth. // If record's current expiry time is more than a second from now, we set it to expire in one second. // If the record is already going to expire in less than one second anyway, we leave it alone -- // we don't want to let the goodbye packet *extend* the record's lifetime in our cache. debugf("DE for %s", CRDisplayString(m, cr)); if (RRExpireTime(cr) - m->timenow > mDNSPlatformOneSecond) { cr->resrec.rroriginalttl = 1; cr->TimeRcvd = m->timenow; cr->UnansweredQueries = MaxUnansweredQueries; SetNextCacheCheckTimeForRecord(m, cr); } break; } } else if (cr->resrec.rroriginalttl != 0 && // Not already marked for discarding m->rec.r.resrec.rrclass == cr->resrec.rrclass && (m->rec.r.resrec.rrtype != cr->resrec.rrtype && (m->rec.r.resrec.rrtype == kDNSType_CNAME || cr->resrec.rrtype == kDNSType_CNAME))) { // If the cache record rrtype doesn't match and one is a CNAME, then flush this record LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNSCoreReceiveCacheCheck: Discarding (%s) " PRI_S " rrtype change from (%s) to (%s)", MortalityDisplayString(cr->resrec.mortality), CRDisplayString(m, cr), DNSTypeName(cr->resrec.rrtype), DNSTypeName(m->rec.r.resrec.rrtype)); mDNS_PurgeCacheResourceRecord(m, cr); // DO NOT break out here -- we want to continue iterating the cache entries } } } return cr; } mDNSlocal void mDNSCoreResetRecord(mDNS *const m) { m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } // Note: mDNSCoreReceiveResponse calls mDNS_Deregister_internal which can call a user callback, which may change // the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. // InterfaceID non-NULL tells us the interface this multicast response was received on // InterfaceID NULL tells us this was a unicast response // dstaddr NULL tells us we received this over an outgoing TCP connection we made mDNSlocal void mDNSCoreReceiveResponse(mDNS *const m, const DNSMessage *const response, const mDNSu8 *end, const mDNSAddr *srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, mDNSIPPort dstport, #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_querier_t querier, mdns_dns_service_t uDNSService, #endif const mDNSInterfaceID InterfaceID) { int i; const mDNSBool ResponseMCast = dstaddr && mDNSAddrIsDNSMulticast(dstaddr); const mDNSBool ResponseSrcLocal = !srcaddr || mDNS_AddressIsLocalSubnet(m, InterfaceID, srcaddr); DNSQuestion *llqMatch = mDNSNULL; uDNS_LLQType LLQType = uDNS_recvLLQResponse(m, response, end, srcaddr, srcport, &llqMatch); // "(CacheRecord*)1" is a special (non-zero) end-of-list marker // We use this non-zero marker so that records in our CacheFlushRecords list will always have NextInCFList // set non-zero, and that tells GetCacheEntity() that they're not, at this moment, eligible for recycling. CacheRecord *CacheFlushRecords = (CacheRecord*)1; CacheRecord **cfp = &CacheFlushRecords; NetworkInterfaceInfo *llintf = FirstIPv4LLInterfaceForID(m, InterfaceID); mDNSBool recordAcceptedInResponse = mDNSfalse; // Set if a record is accepted from a unicast mDNS response that answers an existing question. // All records in a DNS response packet are treated as equally valid statements of truth. If we want // to guard against spoof responses, then the only credible protection against that is cryptographic // security, e.g. DNSSEC., not worrying about which section in the spoof packet contained the record. int firstauthority = response->h.numAnswers; int firstadditional = firstauthority + response->h.numAuthorities; int totalrecords = firstadditional + response->h.numAdditionals; const mDNSu8 *ptr = response->data; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) DNSServer *uDNSServer = mDNSNULL; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) denial_of_existence_records_t *denial_of_existence_records = mDNSNULL; mDNSBool not_answer_but_required_for_dnssec = mDNSfalse; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) // Determine whether the response is mDNS, as opposed to DNS. // Thus far, the code has assumed that responses with IDs set to zero are mDNS responses. However, this condition // isn't sufficient because queriers, which are used exclusively for DNS queries, may set the IDs of their queries // to zero. And consequently, their responses may have their IDs set to zero. Specifically, zero-valued IDs are used // for DNS over HTTPs, as specified by . const mDNSBool ResponseIsMDNS = mDNSOpaque16IsZero(response->h.id) && !querier; #else const mDNSBool ResponseIsMDNS = mDNSOpaque16IsZero(response->h.id); #endif debugf("Received Response from %#-15a addressed to %#-15a on %p with " "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes LLQType %d", srcaddr, dstaddr, InterfaceID, response->h.numQuestions, response->h.numQuestions == 1 ? ", " : "s,", response->h.numAnswers, response->h.numAnswers == 1 ? ", " : "s,", response->h.numAuthorities, response->h.numAuthorities == 1 ? "y, " : "ies,", response->h.numAdditionals, response->h.numAdditionals == 1 ? " " : "s", end - response->data, LLQType); #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) && !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (mDNSSameIPPort(srcport, UnicastDNSPort)) { MetricsUpdateDNSResponseSize((mDNSu32)(end - (mDNSu8 *)response)); } #endif // According to RFC 2181 // When a DNS client receives a reply with TC // set, it should ignore that response, and query again, using a // mechanism, such as a TCP connection, that will permit larger replies. // It feels wrong to be throwing away data after the network went to all the trouble of delivering it to us, but // delivering some records of the RRSet first and then the remainder a couple of milliseconds later was causing // failures in our Microsoft Active Directory client, which expects to get the entire set of answers at once. // Can't bind to Active Directory // In addition, if the client immediately canceled its query after getting the initial partial response, then we'll // abort our TCP connection, and not complete the operation, and end up with an incomplete RRSet in our cache. // Next time there's a query for this RRSet we'll see answers in our cache, and assume we have the whole RRSet already, // and not even do the TCP query. // Accordingly, if we get a uDNS reply with kDNSFlag0_TC set, we bail out and wait for the TCP response containing the // entire RRSet, with the following exception. If the response contains an answer section and one or more records in // either the authority section or additional section, then that implies that truncation occurred beyond the answer // section, and the answer section is therefore assumed to be complete. // // From section 6.2 of RFC 1035 : // When a response is so long that truncation is required, the truncation // should start at the end of the response and work forward in the // datagram. Thus if there is any data for the authority section, the // answer section is guaranteed to be unique. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!InterfaceID && (response->h.flags.b[0] & kDNSFlag0_TC) && !querier && #else if (!InterfaceID && (response->h.flags.b[0] & kDNSFlag0_TC) && #endif ((response->h.numAnswers == 0) || ((response->h.numAuthorities == 0) && (response->h.numAdditionals == 0)))) return; if (LLQType == uDNS_LLQ_Ignore) return; // 1. We ignore questions (if any) in mDNS response packets // 2. If this is an LLQ response, we handle it much the same // Otherwise, this is a authoritative uDNS answer, so arrange for any stale records to be purged if (ResponseMCast || LLQType == uDNS_LLQ_Events) ptr = LocateAnswers(response, end); // Otherwise, for one-shot queries, any answers in our cache that are not also contained // in this response packet are immediately deemed to be invalid. else { mDNSBool failure, returnEarly; const int rcode = response->h.flags.b[1] & kDNSFlag1_RC_Mask; failure = !(rcode == kDNSFlag1_RC_NoErr || rcode == kDNSFlag1_RC_NXDomain || rcode == kDNSFlag1_RC_NotAuth); returnEarly = mDNSfalse; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) // When the QUERIER functionality is enabled, DNS transport is handled exclusively by querier objects. If this // response was provided by a querier, but the RCODE is considered a failure, then set failure to false so that // we don't return early. The logic of returning early was so that uDNS_CheckCurrentQuestion() could handle // resending the query and generate a negative cache record if all servers were tried. If the querier provides a // response, then it's the best response that it could provide. If the RCODE is considered a failure, // mDNSCoreReceiveResponse() needs to create negative cache entries for the unanwered question, so totalrecords // is set to 0 to ignore any records that the response may contain. if (querier && failure) { totalrecords = 0; failure = mDNSfalse; } #endif // We could possibly combine this with the similar loop at the end of this function -- // instead of tagging cache records here and then rescuing them if we find them in the answer section, // we could instead use the "m->PktNum" mechanism to tag each cache record with the packet number in // which it was received (or refreshed), and then at the end if we find any cache records which // answer questions in this packet's question section, but which aren't tagged with this packet's // packet number, then we deduce they are old and delete them for (i = 0; i < response->h.numQuestions && ptr && ptr < end; i++) { DNSQuestion q; DNSQuestion *qptr; mDNSBool expectingResponse; ptr = getQuestion(response, ptr, end, InterfaceID, &q); if (!ptr) { continue; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (querier) { expectingResponse = mDNStrue; qptr = mDNSNULL; } else #endif { qptr = ExpectingUnicastResponseForQuestion(m, dstport, response->h.id, &q, !dstaddr); expectingResponse = qptr ? mDNStrue : mDNSfalse; } if (!expectingResponse) { continue; } if (!failure) { CacheRecord *cr; CacheGroup *cg = CacheGroupForName(m, q.qnamehash, &q.qname); for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { mDNSBool isAnswer; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (querier) { isAnswer = (cr->resrec.dnsservice == uDNSService) && Querier_SameNameCacheRecordIsAnswer(cr, querier); } else #endif { isAnswer = SameNameCacheRecordAnswersQuestion(cr, qptr); } if (isAnswer) { debugf("uDNS marking %p %##s (%s) %p %s", q.InterfaceID, q.qname.c, DNSTypeName(q.qtype), cr->resrec.InterfaceID, CRDisplayString(m, cr)); // Don't want to disturb rroriginalttl here, because code below might need it for the exponential backoff doubling algorithm cr->TimeRcvd = m->timenow - TicksTTL(cr) - 1; cr->UnansweredQueries = MaxUnansweredQueries; } } } else { #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] mDNSCoreReceiveResponse: Server %p responded with code %d to query " PRI_DM_NAME " (" PUB_S ")", qptr->request_id, mDNSVal16(qptr->TargetQID), qptr->qDNSServer, rcode, DM_NAME_PARAM(&q.qname), DNSTypeName(q.qtype)); PenalizeDNSServer(m, qptr, response->h.flags); #endif returnEarly = mDNStrue; } } if (returnEarly) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[Q%d] Ignoring %2d Answer" PUB_S " %2d Authorit" PUB_S " %2d Additional" PUB_S, mDNSVal16(response->h.id), response->h.numAnswers, response->h.numAnswers == 1 ? ", " : "s,", response->h.numAuthorities, response->h.numAuthorities == 1 ? "y, " : "ies,", response->h.numAdditionals, response->h.numAdditionals == 1 ? "" : "s"); // not goto exit because we won't have any CacheFlushRecords and we do not want to // generate negative cache entries (we want to query the next server) return; } } for (i = 0; i < totalrecords && ptr && ptr < end; i++) { // All responses sent via LL multicast are acceptable for caching // All responses received over our outbound TCP connections are acceptable for caching // We accept all records in a unicast response to a multicast query once we find one that // answers an active question. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool AcceptableResponse = ResponseMCast || (!querier && !dstaddr) || LLQType || recordAcceptedInResponse; #else mDNSBool AcceptableResponse = ResponseMCast || !dstaddr || LLQType || recordAcceptedInResponse; #endif // (Note that just because we are willing to cache something, that doesn't necessarily make it a trustworthy answer // to any specific question -- any code reading records from the cache needs to make that determination for itself.) const mDNSu8 RecordType = (i < firstauthority ) ? (mDNSu8)kDNSRecordTypePacketAns : (i < firstadditional) ? (mDNSu8)kDNSRecordTypePacketAuth : (mDNSu8)kDNSRecordTypePacketAdd; ptr = GetLargeResourceRecord(m, response, ptr, end, InterfaceID, RecordType, &m->rec); if (!ptr) goto exit; // Break out of the loop and clean up our CacheFlushRecords list before exiting if (m->rec.r.resrec.RecordType == kDNSRecordTypePacketNegative) { mDNSCoreResetRecord(m); continue; } // Don't want to cache OPT or TSIG pseudo-RRs if (m->rec.r.resrec.rrtype == kDNSType_TSIG) { mDNSCoreResetRecord(m); continue; } if (m->rec.r.resrec.rrtype == kDNSType_OPT) { const rdataOPT *opt; const rdataOPT *const e = (const rdataOPT *)&m->rec.r.resrec.rdata->u.data[m->rec.r.resrec.rdlength]; // Find owner sub-option(s). We verify that the MAC is non-zero, otherwise we could inadvertently // delete all our own AuthRecords (which are identified by having zero MAC tags on them). for (opt = &m->rec.r.resrec.rdata->u.opt[0]; opt < e; opt++) if (opt->opt == kDNSOpt_Owner && opt->u.owner.vers == 0 && opt->u.owner.HMAC.l[0]) { ClearProxyRecords(m, &opt->u.owner, m->DuplicateRecords); ClearProxyRecords(m, &opt->u.owner, m->ResourceRecords); } mDNSCoreResetRecord(m); continue; } // if a CNAME record points to itself, then don't add it to the cache if ((m->rec.r.resrec.rrtype == kDNSType_CNAME) && SameDomainName(m->rec.r.resrec.name, &m->rec.r.resrec.rdata->u.name)) { LogInfo("mDNSCoreReceiveResponse: CNAME loop domain name %##s", m->rec.r.resrec.name->c); mDNSCoreResetRecord(m); continue; } // When we receive uDNS LLQ responses, we assume a long cache lifetime -- // In the case of active LLQs, we'll get remove events when the records actually do go away // In the case of polling LLQs, we assume the record remains valid until the next poll if (!ResponseIsMDNS) { m->rec.r.resrec.rroriginalttl = GetEffectiveTTL(LLQType, m->rec.r.resrec.rroriginalttl); } // If response was not sent via LL multicast, // then see if it answers a recent query of ours, which would also make it acceptable for caching. if (!ResponseMCast) { if (LLQType) { // For Long Lived queries that are both sent over UDP and Private TCP, LLQType is set. // Even though it is AcceptableResponse, we need a matching DNSServer pointer for the // queries to get ADD/RMV events. To lookup the question, we can't use // ExpectingUnicastResponseForRecord as the port numbers don't match. uDNS_recvLLQRespose // has already matched the question using the 64 bit Id in the packet and we use that here. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (querier) { mdns_replace(&m->rec.r.resrec.dnsservice, uDNSService); } #else if (llqMatch != mDNSNULL) m->rec.r.resrec.rDNSServer = uDNSServer = llqMatch->qDNSServer; #endif } else if (!AcceptableResponse || !dstaddr) { // For responses that come over TCP (Responses that can't fit within UDP) or TLS (Private queries // that are not long lived e.g., AAAA lookup in a Private domain), it is indicated by !dstaddr. // Even though it is AcceptableResponse, we still need a DNSServer pointer for the resource records that // we create. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (querier) { ResourceRecord *const rr = &m->rec.r.resrec; if (Querier_ResourceRecordIsAnswer(rr, querier)) { const mdns_resolver_type_t resolver_type = mdns_querier_get_resolver_type(querier); if ((resolver_type == mdns_resolver_type_normal) && (mdns_querier_get_over_tcp_reason(querier) != mdns_query_over_tcp_reason_null)) { rr->protocol = mdns_resolver_type_tcp; } else { rr->protocol = resolver_type; } mdns_replace(&rr->dnsservice, uDNSService); AcceptableResponse = mDNStrue; } } else #endif { const DNSQuestion *q; // Initialize the DNS server on the resource record which will now filter what questions we answer with // this record. // // We could potentially lookup the DNS server based on the source address, but that may not work always // and that's why ExpectingUnicastResponseForRecord does not try to verify whether the response came // from the DNS server that queried. We follow the same logic here. If we can find a matching question based // on the "id" and "source port", then this response answers the question and assume the response // came from the same DNS server that we sent the query to. q = ExpectingUnicastResponseForRecord(m, srcaddr, ResponseSrcLocal, dstport, response->h.id, &m->rec.r, !dstaddr); if (q != mDNSNULL) { AcceptableResponse = mDNStrue; if (!InterfaceID) { debugf("mDNSCoreReceiveResponse: InterfaceID %p %##s (%s)", q->InterfaceID, q->qname.c, DNSTypeName(q->qtype)); #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) m->rec.r.resrec.rDNSServer = uDNSServer = q->qDNSServer; #endif } else { // Accept all remaining records in this unicast response to an mDNS query. recordAcceptedInResponse = mDNStrue; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] mDNSCoreReceiveResponse: Accepting response for query: " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); } } else { // If we can't find a matching question, we need to see whether we have seen records earlier that matched // the question. The code below does that. So, make this record unacceptable for now if (!InterfaceID) { debugf("mDNSCoreReceiveResponse: Can't find question for record name %##s", m->rec.r.resrec.name->c); AcceptableResponse = mDNSfalse; } } } } } else if (llintf && llintf->IgnoreIPv4LL && m->rec.r.resrec.rrtype == kDNSType_A) { // There are some routers (rare, thankfully) that generate bogus ARP responses for // any IPv4 address they don’t recognize, including RFC 3927 IPv4 link-local addresses. // To work with these broken routers, client devices need to blacklist these broken // routers and ignore their bogus ARP responses. Some devices implement a technique // such as the one described in US Patent 7436783, which lets clients detect and // ignore these broken routers: // OS X and iOS do not implement this defensive mechanism, instead taking a simpler // approach of just detecting these broken routers and completely disabling IPv4 // link-local communication on interfaces where a broken router is detected. // OS X and iOS set the IFEF_ARPLL interface flag on interfaces // that are deemed “safe” for IPv4 link-local communication; // the flag is cleared on interfaces where a broken router is detected. // OS X and iOS will not even try to communicate with an IPv4 // link-local destination on an interface without the IFEF_ARPLL flag set. // This can cause some badly written applications to freeze for a long time if they // attempt to connect to an IPv4 link-local destination address and then wait for // that connection attempt to time out before trying other candidate addresses. // To mask this client bug, we suppress acceptance of IPv4 link-local address // records on interfaces where we know the OS will be unwilling even to attempt // communication with those IPv4 link-local destination addresses. // kSuppress IPv4LL answers on interfaces without IFEF_ARPLL const CacheRecord *const rr = &m->rec.r; const RDataBody2 *const rdb = (RDataBody2 *)rr->smallrdatastorage.data; if (mDNSv4AddressIsLinkLocal(&rdb->ipv4)) { LogInfo("mDNSResponder: Dropping LinkLocal packet %s", CRDisplayString(m, &m->rec.r)); mDNSCoreResetRecord(m); continue; } } // 1. Check that this packet resource record does not conflict with any of ours if (ResponseIsMDNS && m->rec.r.resrec.rrtype != kDNSType_NSEC) { if (m->CurrentRecord) LogMsg("mDNSCoreReceiveResponse ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { AuthRecord *rr = m->CurrentRecord; m->CurrentRecord = rr->next; // We accept all multicast responses, and unicast responses resulting from queries we issued // For other unicast responses, this code accepts them only for responses with an // (apparently) local source address that pertain to a record of our own that's in probing state if (!AcceptableResponse && !(ResponseSrcLocal && rr->resrec.RecordType == kDNSRecordTypeUnique)) continue; if (PacketRRMatchesSignature(&m->rec.r, rr)) // If interface, name, type (if shared record) and class match... { // ... check to see if type and rdata are identical if (IdenticalSameNameRecord(&m->rec.r.resrec, &rr->resrec)) { // If the RR in the packet is identical to ours, just check they're not trying to lower the TTL on us if (m->rec.r.resrec.rroriginalttl >= rr->resrec.rroriginalttl/2 || m->SleepState) { // If we were planning to send on this -- and only this -- interface, then we don't need to any more if (rr->ImmedAnswer == InterfaceID) { rr->ImmedAnswer = mDNSNULL; rr->ImmedUnicast = mDNSfalse; } } else { if (rr->ImmedAnswer == mDNSNULL) { rr->ImmedAnswer = InterfaceID; m->NextScheduledResponse = m->timenow; } else if (rr->ImmedAnswer != InterfaceID) { rr->ImmedAnswer = mDNSInterfaceMark; m->NextScheduledResponse = m->timenow; } } } // else, the packet RR has different type or different rdata -- check to see if this is a conflict else if (m->rec.r.resrec.rroriginalttl > 0 && PacketRRConflict(m, rr, &m->rec.r)) { LogInfo("mDNSCoreReceiveResponse: Pkt Record: %08lX %s (interface %d)", m->rec.r.resrec.rdatahash, CRDisplayString(m, &m->rec.r), IIDPrintable(InterfaceID)); LogInfo("mDNSCoreReceiveResponse: Our Record: %08lX %s", rr->resrec.rdatahash, ARDisplayString(m, rr)); // If this record is marked DependentOn another record for conflict detection purposes, // then *that* record has to be bumped back to probing state to resolve the conflict if (rr->DependentOn) { while (rr->DependentOn) rr = rr->DependentOn; LogInfo("mDNSCoreReceiveResponse: Dep Record: %08lX %s", rr->resrec.rdatahash, ARDisplayString(m, rr)); } // If we've just whacked this record's ProbeCount, don't need to do it again if (rr->ProbeCount > DefaultProbeCountForTypeUnique) LogInfo("mDNSCoreReceiveResponse: Already reset to Probing: %s", ARDisplayString(m, rr)); else if (rr->ProbeCount == DefaultProbeCountForTypeUnique) LogInfo("mDNSCoreReceiveResponse: Ignoring response received before we even began probing: %s", ARDisplayString(m, rr)); else { LogMsg("mDNSCoreReceiveResponse: Received from %#a:%d %s", srcaddr, mDNSVal16(srcport), CRDisplayString(m, &m->rec.r)); // If we'd previously verified this record, put it back to probing state and try again if (rr->resrec.RecordType == kDNSRecordTypeVerified) { LogMsg("mDNSCoreReceiveResponse: Resetting to Probing: %s", ARDisplayString(m, rr)); rr->resrec.RecordType = kDNSRecordTypeUnique; // We set ProbeCount to one more than the usual value so we know we've already touched this record. // This is because our single probe for "example-name.local" could yield a response with (say) two A records and // three AAAA records in it, and we don't want to call RecordProbeFailure() five times and count that as five conflicts. // This special value is recognised and reset to DefaultProbeCountForTypeUnique in SendQueries(). rr->ProbeCount = DefaultProbeCountForTypeUnique + 1; rr->AnnounceCount = InitialAnnounceCount; InitializeLastAPTime(m, rr); RecordProbeFailure(m, rr); // Repeated late conflicts also cause us to back off to the slower probing rate } // If we're probing for this record, we just failed else if (rr->resrec.RecordType == kDNSRecordTypeUnique) { // At this point in the code, we're probing for uniqueness. // We've sent at least one probe (rr->ProbeCount < DefaultProbeCountForTypeUnique) // but we haven't completed probing yet (rr->resrec.RecordType == kDNSRecordTypeUnique). // Before we call deregister, check if this is a packet we registered with the sleep proxy. if (!mDNSCoreRegisteredProxyRecord(m, rr)) { if ((rr->ProbingConflictCount == 0) || (m->MPktNum != rr->LastConflictPktNum)) { const NetworkInterfaceInfo *const intf = FirstInterfaceForID(m, InterfaceID); rr->ProbingConflictCount++; rr->LastConflictPktNum = m->MPktNum; if (ResponseMCast && (!intf || intf->SupportsUnicastMDNSResponse) && (rr->ProbingConflictCount <= kMaxAllowedMCastProbingConflicts)) { LogMsg("mDNSCoreReceiveResponse: ProbeCount %d; restarting probing after %d-tick pause due to possibly " "spurious multicast conflict (%d/%d) via interface %d for %s", rr->ProbeCount, kProbingConflictPauseDuration, rr->ProbingConflictCount, kMaxAllowedMCastProbingConflicts, IIDPrintable(InterfaceID), ARDisplayString(m, rr)); rr->ProbeCount = DefaultProbeCountForTypeUnique; rr->LastAPTime = m->timenow + kProbingConflictPauseDuration - rr->ThisAPInterval; SetNextAnnounceProbeTime(m, rr); } else { LogMsg("mDNSCoreReceiveResponse: ProbeCount %d; will deregister %s due to %scast conflict via interface %d", rr->ProbeCount, ARDisplayString(m, rr), ResponseMCast ? "multi" : "uni", IIDPrintable(InterfaceID)); m->mDNSStats.NameConflicts++; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) // See if this record was also registered with any D2D plugins. D2D_stop_advertising_record(rr); #endif mDNS_Deregister_internal(m, rr, mDNS_Dereg_conflict); } } } } // We assumed this record must be unique, but we were wrong. (e.g. There are two mDNSResponders on the // same machine giving different answers for the reverse mapping record, or there are two machines on the // network using the same IP address.) This is simply a misconfiguration, and there's nothing we can do // to fix it -- e.g. it's not our job to be trying to change the machine's IP address. We just discard our // record to avoid continued conflicts (as we do for a conflict on our Unique records) and get on with life. else if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique) { LogMsg("mDNSCoreReceiveResponse: Unexpected conflict discarding %s", ARDisplayString(m, rr)); m->mDNSStats.KnownUniqueNameConflicts++; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) D2D_stop_advertising_record(rr); #endif mDNS_Deregister_internal(m, rr, mDNS_Dereg_conflict); } else LogMsg("mDNSCoreReceiveResponse: Unexpected record type %X %s", rr->resrec.RecordType, ARDisplayString(m, rr)); } } // Else, matching signature, different type or rdata, but not a considered a conflict. // If the packet record has the cache-flush bit set, then we check to see if we // have any record(s) of the same type that we should re-assert to rescue them // (see note about "multi-homing and bridged networks" at the end of this function). else if ((m->rec.r.resrec.rrtype == rr->resrec.rrtype) && (m->rec.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) && ((mDNSu32)(m->timenow - rr->LastMCTime) > (mDNSu32)mDNSPlatformOneSecond/2) && ResourceRecordIsValidAnswer(rr)) { rr->ImmedAnswer = mDNSInterfaceMark; m->NextScheduledResponse = m->timenow; } } } } if (!AcceptableResponse) { #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) not_answer_but_required_for_dnssec = adds_denial_records_in_cache_record(&m->rec.r.resrec, querier != mDNSNULL && mdns_querier_get_dnssec_ok(querier), &denial_of_existence_records); #else not_answer_but_required_for_dnssec = mDNSfalse; #endif #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) AcceptableResponse = IsResponseAcceptable(m, CacheFlushRecords); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (AcceptableResponse) mdns_replace(&m->rec.r.resrec.dnsservice, uDNSService); #else if (AcceptableResponse) m->rec.r.resrec.rDNSServer = uDNSServer; #endif } // 2. See if we want to add this packet resource record to our cache // We only try to cache answers if we have a cache to put them in // Also, we ignore any apparent attempts at cache poisoning unicast to us that do not answer any outstanding active query if (!AcceptableResponse) { const char* savedString = ""; #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) savedString = (not_answer_but_required_for_dnssec ? "Saved for DNSSEC" : ""); #endif LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[Q%d] mDNSCoreReceiveResponse ignoring " PRI_S " %s", mDNSVal16(response->h.id), CRDisplayString(m, &m->rec.r), savedString); } if (m->rrcache_size && AcceptableResponse) { const mDNSu32 slot = HashSlotFromNameHash(m->rec.r.resrec.namehash); CacheGroup *cg = CacheGroupForRecord(m, &m->rec.r.resrec); CacheRecord *rr = mDNSNULL; // 2a. Check if this packet resource record is already in our cache. rr = mDNSCoreReceiveCacheCheck(m, response, LLQType, slot, cg, &cfp, InterfaceID); // If packet resource record not in our cache, add it now // (unless it is just a deletion of a record we never had, in which case we don't care) if (!rr && m->rec.r.resrec.rroriginalttl > 0) { const mDNSBool AddToCFList = (m->rec.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) && (LLQType != uDNS_LLQ_Events); mDNSs32 delay; if (AddToCFList) delay = NonZeroTime(m->timenow + mDNSPlatformOneSecond); else delay = CheckForSoonToExpireRecords(m, m->rec.r.resrec.name, m->rec.r.resrec.namehash); // If unique, assume we may have to delay delivery of this 'add' event. // Below, where we walk the CacheFlushRecords list, we either call CacheRecordDeferredAdd() // to immediately to generate answer callbacks, or we call ScheduleNextCacheCheckTime() // to schedule an mDNS_Execute task at the appropriate time. rr = CreateNewCacheEntry(m, slot, cg, delay, mDNStrue, srcaddr); if (rr) { #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) set_denial_records_in_cache_record(rr, &denial_of_existence_records); #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) rr->responseFlags = response->h.flags; if (AddToCFList) { *cfp = rr; cfp = &rr->NextInCFList; *cfp = (CacheRecord*)1; } else if (rr->DelayDelivery) { ScheduleNextCacheCheckTime(m, slot, rr->DelayDelivery); } } } } mDNSCoreResetRecord(m); } exit: mDNSCoreResetRecord(m); // If we've just received one or more records with their cache flush bits set, // then scan that cache slot to see if there are any old stale records we need to flush while (CacheFlushRecords != (CacheRecord*)1) { CacheRecord *r1 = CacheFlushRecords, *r2; const mDNSu32 slot = HashSlotFromNameHash(r1->resrec.namehash); const CacheGroup *cg = CacheGroupForRecord(m, &r1->resrec); mDNSBool purgedRecords = mDNSfalse; CacheFlushRecords = CacheFlushRecords->NextInCFList; r1->NextInCFList = mDNSNULL; // Look for records in the cache with the same signature as this new one with the cache flush // bit set, and either (a) if they're fresh, just make sure the whole RRSet has the same TTL // (as required by DNS semantics) or (b) if they're old, mark them for deletion in one second. // We make these TTL adjustments *only* for records that still have *more* than one second // remaining to live. Otherwise, a record that we tagged for deletion half a second ago // (and now has half a second remaining) could inadvertently get its life extended, by either // (a) if we got an explicit goodbye packet half a second ago, the record would be considered // "fresh" and would be incorrectly resurrected back to the same TTL as the rest of the RRSet, // or (b) otherwise, the record would not be fully resurrected, but would be reset to expire // in one second, thereby inadvertently delaying its actual expiration, instead of hastening it. // If this were to happen repeatedly, the record's expiration could be deferred indefinitely. // To avoid this, we need to ensure that the cache flushing operation will only act to // *decrease* a record's remaining lifetime, never *increase* it. for (r2 = cg ? cg->members : mDNSNULL; r2; r2=r2->next) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool match; #else mDNSu32 id1; mDNSu32 id2; #endif if (!r1->resrec.InterfaceID) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) match = (r1->resrec.dnsservice == r2->resrec.dnsservice) ? mDNStrue : mDNSfalse; #else id1 = (r1->resrec.rDNSServer ? r1->resrec.rDNSServer->resGroupID : 0); id2 = (r2->resrec.rDNSServer ? r2->resrec.rDNSServer->resGroupID : 0); #endif } else { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) match = mDNStrue; #else id1 = id2 = 0; #endif } // For Unicast (null InterfaceID) the resolver IDs should also match if ((r1->resrec.InterfaceID == r2->resrec.InterfaceID) && #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) (r1->resrec.InterfaceID || match) && #else (r1->resrec.InterfaceID || (id1 == id2)) && #endif r1->resrec.rrtype == r2->resrec.rrtype && r1->resrec.rrclass == r2->resrec.rrclass #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // 2 RRSIGs need to cover the same DNS type to be identified as one RRSET, and have the same TTL && are_records_in_the_same_cache_set_for_dnssec(&r1->resrec, &r2->resrec) #endif ) { if (r1->resrec.mortality == Mortality_Mortal && r2->resrec.mortality != Mortality_Mortal) { verbosedebugf("mDNSCoreReceiveResponse: R1(%p) is being immortalized by R2(%p)", r1, r2); r1->resrec.mortality = Mortality_Immortal; // Immortalize the replacement record } // If record is recent, just ensure the whole RRSet has the same TTL (as required by DNS semantics) // else, if record is old, mark it to be flushed if (m->timenow - r2->TimeRcvd < mDNSPlatformOneSecond && RRExpireTime(r2) - m->timenow > mDNSPlatformOneSecond) { // If we find mismatched TTLs in an RRSet, correct them. // We only do this for records with a TTL of 2 or higher. It's possible to have a // goodbye announcement with the cache flush bit set (or a case-change on record rdata, // which we treat as a goodbye followed by an addition) and in that case it would be // inappropriate to synchronize all the other records to a TTL of 0 (or 1). // We suppress the message for the specific case of correcting from 240 to 60 for type TXT, // because certain early Bonjour devices are known to have this specific mismatch, and // there's no point filling syslog with messages about something we already know about. // We also don't log this for uDNS responses, since a caching name server is obliged // to give us an aged TTL to correct for how long it has held the record, // so our received TTLs are expected to vary in that case // We also suppress log message in the case of SRV records that are received // with a TTL of 4500 that are already cached with a TTL of 120 seconds, since // this behavior was observed for a number of discoveryd based AppleTV's in iOS 8 // GM builds. if (r2->resrec.rroriginalttl != r1->resrec.rroriginalttl && r1->resrec.rroriginalttl > 1) { if (!(r2->resrec.rroriginalttl == 240 && r1->resrec.rroriginalttl == 60 && r2->resrec.rrtype == kDNSType_TXT) && !(r2->resrec.rroriginalttl == 120 && r1->resrec.rroriginalttl == 4500 && r2->resrec.rrtype == kDNSType_SRV) && ResponseIsMDNS) LogInfo("Correcting TTL from %4d to %4d for %s", r2->resrec.rroriginalttl, r1->resrec.rroriginalttl, CRDisplayString(m, r2)); r2->resrec.rroriginalttl = r1->resrec.rroriginalttl; } r2->TimeRcvd = m->timenow; SetNextCacheCheckTimeForRecord(m, r2); } else if (r2->resrec.InterfaceID) // else, if record is old, mark it to be flushed { verbosedebugf("Cache flush new %p age %d expire in %d %s", r1, m->timenow - r1->TimeRcvd, RRExpireTime(r1) - m->timenow, CRDisplayString(m, r1)); verbosedebugf("Cache flush old %p age %d expire in %d %s", r2, m->timenow - r2->TimeRcvd, RRExpireTime(r2) - m->timenow, CRDisplayString(m, r2)); // We set stale records to expire in one second. // This gives the owner a chance to rescue it if necessary. // This is important in the case of multi-homing and bridged networks: // Suppose host X is on Ethernet. X then connects to an AirPort base station, which happens to be // bridged onto the same Ethernet. When X announces its AirPort IP address with the cache-flush bit // set, the AirPort packet will be bridged onto the Ethernet, and all other hosts on the Ethernet // will promptly delete their cached copies of the (still valid) Ethernet IP address record. // By delaying the deletion by one second, we give X a change to notice that this bridging has // happened, and re-announce its Ethernet IP address to rescue it from deletion from all our caches. // We set UnansweredQueries to MaxUnansweredQueries to avoid expensive and unnecessary // final expiration queries for this record. // If a record is deleted twice, first with an explicit DE record, then a second time by virtue of the cache // flush bit on the new record replacing it, then we allow the record to be deleted immediately, without the usual // one-second grace period. This improves responsiveness for mDNS_Update(), as used for things like iChat status updates. // Updating TXT records is too slow // We check for "rroriginalttl == 1" because we want to include records tagged by the "packet TTL is zero" check above, // which sets rroriginalttl to 1, but not records tagged by the rdata case-change check, which sets rroriginalttl to 0. if (r2->TimeRcvd == m->timenow && r2->resrec.rroriginalttl == 1 && r2->UnansweredQueries == MaxUnansweredQueries) { LogInfo("Cache flush for DE record %s", CRDisplayString(m, r2)); r2->resrec.rroriginalttl = 0; } else if (RRExpireTime(r2) - m->timenow > mDNSPlatformOneSecond) { // We only set a record to expire in one second if it currently has *more* than a second to live // If it's already due to expire in a second or less, we just leave it alone r2->resrec.rroriginalttl = 1; r2->UnansweredQueries = MaxUnansweredQueries; r2->TimeRcvd = m->timenow - 1; // We use (m->timenow - 1) instead of m->timenow, because we use that to identify records // that we marked for deletion via an explicit DE record } SetNextCacheCheckTimeForRecord(m, r2); } else { #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if (r2->resrec.mortality == Mortality_Ghost) { DNSQuestion * q; for (q = m->Questions; q; q=q->next) { if (!q->LongLived && ActiveQuestion(q) && CacheRecordAnswersQuestion(r2, q) && q->metrics.expiredAnswerState == ExpiredAnswer_AnsweredWithExpired) { q->metrics.expiredAnswerState = ExpiredAnswer_ExpiredAnswerChanged; } } } #endif // Old uDNS records are scheduled to be purged instead of given at most one second to live. mDNS_PurgeCacheResourceRecord(m, r2); purgedRecords = mDNStrue; } } } if (r1->DelayDelivery) // If we were planning to delay delivery of this record, see if we still need to { if (r1->resrec.InterfaceID) { r1->DelayDelivery = CheckForSoonToExpireRecords(m, r1->resrec.name, r1->resrec.namehash); } else { // If uDNS records from an older RRset were scheduled to be purged, then delay delivery slightly to allow // them to be deleted before any ADD events for this record. r1->DelayDelivery = purgedRecords ? NonZeroTime(m->timenow) : 0; } // If no longer delaying, deliver answer now, else schedule delivery for the appropriate time if (!r1->DelayDelivery) CacheRecordDeferredAdd(m, r1); else ScheduleNextCacheCheckTime(m, slot, r1->DelayDelivery); } } // See if we need to generate negative cache entries for unanswered unicast questions mDNSCoreReceiveNoUnicastAnswers(m, response, end, dstaddr, dstport, InterfaceID, #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) querier, uDNSService, #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) &denial_of_existence_records, #endif LLQType); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) destroy_denial_of_existence_records_t_if_nonnull(denial_of_existence_records); #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) } // ScheduleWakeup causes all proxy records with WakeUp.HMAC matching mDNSEthAddr 'e' to be deregistered, causing // multiple wakeup magic packets to be sent if appropriate, and all records to be ultimately freed after a few seconds. // ScheduleWakeup is called on mDNS record conflicts, ARP conflicts, NDP conflicts, or reception of trigger traffic // that warrants waking the sleeping host. // ScheduleWakeup must be called with the lock held (ScheduleWakeupForList uses mDNS_Deregister_internal) mDNSlocal void ScheduleWakeupForList(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSEthAddr *e, AuthRecord *const thelist) { // We need to use the m->CurrentRecord mechanism here when dealing with DuplicateRecords list as // mDNS_Deregister_internal deregisters duplicate records immediately as they are not used // to send wakeups or goodbyes. See the comment in that function for more details. To keep it // simple, we use the same mechanism for both lists. if (!e->l[0]) { LogMsg("ScheduleWakeupForList ERROR: Target HMAC is zero"); return; } m->CurrentRecord = thelist; while (m->CurrentRecord) { AuthRecord *const rr = m->CurrentRecord; if (rr->resrec.InterfaceID == InterfaceID && rr->resrec.RecordType != kDNSRecordTypeDeregistering && mDNSSameEthAddress(&rr->WakeUp.HMAC, e)) { LogInfo("ScheduleWakeupForList: Scheduling wakeup packets for %s", ARDisplayString(m, rr)); mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); } if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } mDNSlocal void ScheduleWakeup(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSEthAddr *e) { if (!e->l[0]) { LogMsg("ScheduleWakeup ERROR: Target HMAC is zero"); return; } ScheduleWakeupForList(m, InterfaceID, e, m->DuplicateRecords); ScheduleWakeupForList(m, InterfaceID, e, m->ResourceRecords); } mDNSlocal void SPSRecordCallback(mDNS *const m, AuthRecord *const ar, mStatus result) { if (result && result != mStatus_MemFree) LogInfo("SPS Callback %d %s", result, ARDisplayString(m, ar)); if (result == mStatus_NameConflict) { mDNS_Lock(m); LogMsg("%-7s Conflicting mDNS -- waking %.6a %s", InterfaceNameForID(m, ar->resrec.InterfaceID), &ar->WakeUp.HMAC, ARDisplayString(m, ar)); if (ar->WakeUp.HMAC.l[0]) { SendWakeup(m, ar->resrec.InterfaceID, &ar->WakeUp.IMAC, &ar->WakeUp.password, mDNSfalse); // Send one wakeup magic packet ScheduleWakeup(m, ar->resrec.InterfaceID, &ar->WakeUp.HMAC); // Schedule all other records with the same owner to be woken } mDNS_Unlock(m); } if (result == mStatus_NameConflict || result == mStatus_MemFree) { m->ProxyRecords--; mDNSPlatformMemFree(ar); mDNS_UpdateAllowSleep(m); } } mDNSlocal mDNSu8 *GetValueForMACAddr(mDNSu8 *ptr, mDNSu8 *limit, mDNSEthAddr *eth) { int i; mDNSs8 hval = 0; int colons = 0; mDNSu16 val = 0; /* need to use 16 bit int to detect overflow */ for (i = 0; ptr < limit && *ptr != ' ' && i < 17; i++, ptr++) { hval = HexVal(*ptr); if (hval != -1) { val <<= 4; val |= hval; } else if (*ptr == ':') { if (colons >=5) { LogMsg("GetValueForMACAddr: Address malformed colons %d val %d", colons, val); return mDNSNULL; } eth->b[colons] = (mDNSs8)val; colons++; val = 0; } } if (colons != 5) { LogMsg("GetValueForMACAddr: Address malformed colons %d", colons); return mDNSNULL; } eth->b[colons] = (mDNSs8)val; return ptr; } mDNSlocal mDNSu8 *GetValueForIPv6Addr(mDNSu8 *ptr, mDNSu8 *limit, mDNSv6Addr *v6) { int hval; int value; int numBytes; int digitsProcessed; int zeroFillStart; int numColons; mDNSu8 v6addr[16]; // RFC 3513: Section 2.2 specifies IPv6 presentation format. The following parsing // handles both (1) and (2) and does not handle embedded IPv4 addresses. // // First forms a address in "v6addr", then expands to fill the zeroes in and returns // the result in "v6" numColons = numBytes = value = digitsProcessed = zeroFillStart = 0; while (ptr < limit && *ptr != ' ') { hval = HexVal(*ptr); if (hval != -1) { value <<= 4; value |= hval; digitsProcessed = 1; } else if (*ptr == ':') { if (!digitsProcessed) { // If we have already seen a "::", we should not see one more. Handle the special // case of "::" if (numColons) { // if we never filled any bytes and the next character is space (we have reached the end) // we are done if (!numBytes && (ptr + 1) < limit && *(ptr + 1) == ' ') { mDNSPlatformMemZero(v6->b, 16); return ptr + 1; } LogMsg("GetValueForIPv6Addr: zeroFillStart non-zero %d", zeroFillStart); return mDNSNULL; } // We processed "::". We need to fill zeroes later. For now, mark the // point where we will start filling zeroes from. zeroFillStart = numBytes; numColons++; } else if ((ptr + 1) < limit && *(ptr + 1) == ' ') { // We have a trailing ":" i.e., no more characters after ":" LogMsg("GetValueForIPv6Addr: Trailing colon"); return mDNSNULL; } else { // For a fully expanded IPv6 address, we fill the 14th and 15th byte outside of this while // loop below as there is no ":" at the end. Hence, the last two bytes that can possibly // filled here is 12 and 13. if (numBytes > 13) { LogMsg("GetValueForIPv6Addr:1: numBytes is %d", numBytes); return mDNSNULL; } v6addr[numBytes++] = (mDNSu8) ((value >> 8) & 0xFF); v6addr[numBytes++] = (mDNSu8) (value & 0xFF); digitsProcessed = value = 0; // Make sure that we did not fill the 13th and 14th byte above if (numBytes > 14) { LogMsg("GetValueForIPv6Addr:2: numBytes is %d", numBytes); return mDNSNULL; } } } ptr++; } // We should be processing the last set of bytes following the last ":" here if (!digitsProcessed) { LogMsg("GetValueForIPv6Addr: no trailing bytes after colon, numBytes is %d", numBytes); return mDNSNULL; } if (numBytes > 14) { LogMsg("GetValueForIPv6Addr:3: numBytes is %d", numBytes); return mDNSNULL; } v6addr[numBytes++] = (mDNSu8) ((value >> 8) & 0xFF); v6addr[numBytes++] = (mDNSu8) (value & 0xFF); if (zeroFillStart) { int i, j, n; for (i = 0; i < zeroFillStart; i++) v6->b[i] = v6addr[i]; for (j = i, n = 0; n < 16 - numBytes; j++, n++) v6->b[j] = 0; for (; j < 16; i++, j++) v6->b[j] = v6addr[i]; } else if (numBytes == 16) mDNSPlatformMemCopy(v6->b, v6addr, 16); else { LogMsg("GetValueForIPv6addr: Not enough bytes for IPv6 address, numBytes is %d", numBytes); return mDNSNULL; } return ptr; } mDNSlocal mDNSu8 *GetValueForIPv4Addr(mDNSu8 *ptr, mDNSu8 *limit, mDNSv4Addr *v4) { mDNSu32 val; int dots = 0; val = 0; for ( ; ptr < limit && *ptr != ' '; ptr++) { if (*ptr >= '0' && *ptr <= '9') val = val * 10 + *ptr - '0'; else if (*ptr == '.') { if (val > 255 || dots >= 3) { LogMsg("GetValueForIPv4Addr: something wrong ptr(%p) %c, limit %p, dots %d", ptr, *ptr, limit, dots); return mDNSNULL; } v4->b[dots++] = val; val = 0; } else { // We have a zero at the end and if we reached that, then we are done. if (*ptr == 0 && ptr == limit - 1 && dots == 3) { v4->b[dots] = val; return ptr + 1; } else { LogMsg("GetValueForIPv4Addr: something wrong ptr(%p) %c, limit %p, dots %d", ptr, *ptr, limit, dots); return mDNSNULL; } } } if (dots != 3) { LogMsg("GetValueForIPv4Addr: Address malformed dots %d", dots); return mDNSNULL; } v4->b[dots] = val; return ptr; } mDNSlocal mDNSu8 *GetValueForKeepalive(mDNSu8 *ptr, mDNSu8 *limit, mDNSu32 *value) { mDNSu32 val; val = 0; for ( ; ptr < limit && *ptr != ' '; ptr++) { if (*ptr < '0' || *ptr > '9') { // We have a zero at the end and if we reached that, then we are done. if (*ptr == 0 && ptr == limit - 1) { *value = val; return ptr + 1; } else { LogMsg("GetValueForKeepalive: *ptr %d, ptr %p, limit %p, ptr +1 %d", *ptr, ptr, limit, *(ptr + 1)); return mDNSNULL; } } val = val * 10 + *ptr - '0'; } *value = val; return ptr; } mDNSexport mDNSBool mDNSValidKeepAliveRecord(AuthRecord *rr) { mDNSAddr laddr, raddr; mDNSEthAddr eth; mDNSIPPort lport, rport; mDNSu32 timeout, seq, ack; mDNSu16 win; if (!mDNS_KeepaliveRecord(&rr->resrec)) { return mDNSfalse; } timeout = seq = ack = 0; win = 0; laddr = raddr = zeroAddr; lport = rport = zeroIPPort; eth = zeroEthAddr; mDNS_ExtractKeepaliveInfo(rr, &timeout, &laddr, &raddr, ð, &seq, &ack, &lport, &rport, &win); if (mDNSAddressIsZero(&laddr) || mDNSIPPortIsZero(lport) || mDNSAddressIsZero(&raddr) || mDNSIPPortIsZero(rport) || mDNSEthAddressIsZero(eth)) { return mDNSfalse; } return mDNStrue; } mDNSlocal void mDNS_ExtractKeepaliveInfo(AuthRecord *ar, mDNSu32 *timeout, mDNSAddr *laddr, mDNSAddr *raddr, mDNSEthAddr *eth, mDNSu32 *seq, mDNSu32 *ack, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu16 *win) { if (ar->resrec.rrtype != kDNSType_NULL) return; if (mDNS_KeepaliveRecord(&ar->resrec)) { int len = ar->resrec.rdlength; mDNSu8 *ptr = &ar->resrec.rdata->u.txt.c[1]; mDNSu8 *limit = ptr + len - 1; // Exclude the first byte that is the length mDNSu32 value = 0; while (ptr < limit) { mDNSu8 param = *ptr; ptr += 2; // Skip the letter and the "=" if (param == 'h') { laddr->type = mDNSAddrType_IPv4; ptr = GetValueForIPv4Addr(ptr, limit, &laddr->ip.v4); } else if (param == 'd') { raddr->type = mDNSAddrType_IPv4; ptr = GetValueForIPv4Addr(ptr, limit, &raddr->ip.v4); } else if (param == 'H') { laddr->type = mDNSAddrType_IPv6; ptr = GetValueForIPv6Addr(ptr, limit, &laddr->ip.v6); } else if (param == 'D') { raddr->type = mDNSAddrType_IPv6; ptr = GetValueForIPv6Addr(ptr, limit, &raddr->ip.v6); } else if (param == 'm') { ptr = GetValueForMACAddr(ptr, limit, eth); } else { ptr = GetValueForKeepalive(ptr, limit, &value); } if (!ptr) { LogMsg("mDNS_ExtractKeepaliveInfo: Cannot parse\n"); return; } // Extract everything in network order so that it is easy for sending a keepalive and also // for matching incoming TCP packets switch (param) { case 't': *timeout = value; //if (*timeout < 120) *timeout = 120; break; case 'h': case 'H': case 'd': case 'D': case 'm': case 'i': case 'c': break; case 'l': lport->NotAnInteger = swap16((mDNSu16)value); break; case 'r': rport->NotAnInteger = swap16((mDNSu16)value); break; case 's': *seq = swap32(value); break; case 'a': *ack = swap32(value); break; case 'w': *win = swap16((mDNSu16)value); break; default: LogMsg("mDNS_ExtractKeepaliveInfo: unknown value %c\n", param); ptr = limit; break; } ptr++; // skip the space } } } // Matches the proxied auth records to the incoming TCP packet and returns the match and its sequence and ack in "rseq" and "rack" so that // the clients need not retrieve this information from the auth record again. mDNSlocal AuthRecord* mDNS_MatchKeepaliveInfo(mDNS *const m, const mDNSAddr* pladdr, const mDNSAddr* praddr, const mDNSIPPort plport, const mDNSIPPort prport, mDNSu32 *rseq, mDNSu32 *rack) { AuthRecord *ar; mDNSAddr laddr, raddr; mDNSEthAddr eth; mDNSIPPort lport, rport; mDNSu32 timeout, seq, ack; mDNSu16 win; for (ar = m->ResourceRecords; ar; ar=ar->next) { timeout = seq = ack = 0; win = 0; laddr = raddr = zeroAddr; lport = rport = zeroIPPort; if (!ar->WakeUp.HMAC.l[0]) continue; mDNS_ExtractKeepaliveInfo(ar, &timeout, &laddr, &raddr, ð, &seq, &ack, &lport, &rport, &win); // Did we parse correctly ? if (!timeout || mDNSAddressIsZero(&laddr) || mDNSAddressIsZero(&raddr) || !seq || !ack || mDNSIPPortIsZero(lport) || mDNSIPPortIsZero(rport) || !win) { debugf("mDNS_MatchKeepaliveInfo: not a valid record %s for keepalive", ARDisplayString(m, ar)); continue; } debugf("mDNS_MatchKeepaliveInfo: laddr %#a pladdr %#a, raddr %#a praddr %#a, lport %d plport %d, rport %d prport %d", &laddr, pladdr, &raddr, praddr, mDNSVal16(lport), mDNSVal16(plport), mDNSVal16(rport), mDNSVal16(prport)); // Does it match the incoming TCP packet ? if (mDNSSameAddress(&laddr, pladdr) && mDNSSameAddress(&raddr, praddr) && mDNSSameIPPort(lport, plport) && mDNSSameIPPort(rport, prport)) { // returning in network order *rseq = seq; *rack = ack; return ar; } } return mDNSNULL; } mDNSlocal void mDNS_SendKeepalives(mDNS *const m) { AuthRecord *ar; for (ar = m->ResourceRecords; ar; ar=ar->next) { mDNSu32 timeout, seq, ack; mDNSu16 win; mDNSAddr laddr, raddr; mDNSEthAddr eth; mDNSIPPort lport, rport; timeout = seq = ack = 0; win = 0; laddr = raddr = zeroAddr; lport = rport = zeroIPPort; if (!ar->WakeUp.HMAC.l[0]) continue; mDNS_ExtractKeepaliveInfo(ar, &timeout, &laddr, &raddr, ð, &seq, &ack, &lport, &rport, &win); if (!timeout || mDNSAddressIsZero(&laddr) || mDNSAddressIsZero(&raddr) || !seq || !ack || mDNSIPPortIsZero(lport) || mDNSIPPortIsZero(rport) || !win) { debugf("mDNS_SendKeepalives: not a valid record %s for keepalive", ARDisplayString(m, ar)); continue; } LogMsg("mDNS_SendKeepalives: laddr %#a raddr %#a lport %d rport %d", &laddr, &raddr, mDNSVal16(lport), mDNSVal16(rport)); // When we receive a proxy update, we set KATimeExpire to zero so that we always send a keepalive // immediately (to detect any potential problems). After that we always set it to a non-zero value. if (!ar->KATimeExpire || (m->timenow - ar->KATimeExpire >= 0)) { mDNSPlatformSendKeepalive(&laddr, &raddr, &lport, &rport, seq, ack, win); ar->KATimeExpire = NonZeroTime(m->timenow + timeout * mDNSPlatformOneSecond); } if (m->NextScheduledKA - ar->KATimeExpire > 0) m->NextScheduledKA = ar->KATimeExpire; } } mDNSlocal void mDNS_SendKeepaliveACK(mDNS *const m, AuthRecord *ar) { mDNSu32 timeout, seq, ack, seqInc; mDNSu16 win; mDNSAddr laddr, raddr; mDNSEthAddr eth; mDNSIPPort lport, rport; mDNSu8 *ptr; if (ar == mDNSNULL) { LogInfo("mDNS_SendKeepalivesACK: AuthRecord is NULL"); return; } timeout = seq = ack = 0; win = 0; laddr = raddr = zeroAddr; lport = rport = zeroIPPort; mDNS_ExtractKeepaliveInfo(ar, &timeout, &laddr, &raddr, ð, &seq, &ack, &lport, &rport, &win); if (!timeout || mDNSAddressIsZero(&laddr) || mDNSAddressIsZero(&raddr) || !seq || !ack || mDNSIPPortIsZero(lport) || mDNSIPPortIsZero(rport) || !win) { LogInfo("mDNS_SendKeepaliveACK: not a valid record %s for keepalive", ARDisplayString(m, ar)); return; } // To send a keepalive ACK, we need to add one to the sequence number from the keepalive // record, which is the TCP connection's "next" sequence number minus one. Otherwise, the // keepalive ACK also ends up being a keepalive probe. Also, seq is in network byte order, so // it's converted to host byte order before incrementing it by one. ptr = (mDNSu8 *)&seq; seqInc = (mDNSu32)((ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] << 8) | ptr[3]) + 1; ptr[0] = (mDNSu8)((seqInc >> 24) & 0xFF); ptr[1] = (mDNSu8)((seqInc >> 16) & 0xFF); ptr[2] = (mDNSu8)((seqInc >> 8) & 0xFF); ptr[3] = (mDNSu8)((seqInc ) & 0xFF); LogMsg("mDNS_SendKeepaliveACK: laddr %#a raddr %#a lport %d rport %d", &laddr, &raddr, mDNSVal16(lport), mDNSVal16(rport)); mDNSPlatformSendKeepalive(&laddr, &raddr, &lport, &rport, seq, ack, win); } mDNSlocal void mDNSCoreReceiveUpdate(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *end, const mDNSAddr *srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, mDNSIPPort dstport, const mDNSInterfaceID InterfaceID) { int i; AuthRecord opt; mDNSu8 *p = m->omsg.data; OwnerOptData owner = zeroOwner; // Need to zero this, so we'll know if this Update packet was missing its Owner option mDNSu32 updatelease = 0; const mDNSu8 *ptr; LogSPS("Received Update from %#-15a:%-5d to %#-15a:%-5d on 0x%p with " "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes", srcaddr, mDNSVal16(srcport), dstaddr, mDNSVal16(dstport), InterfaceID, msg->h.numQuestions, msg->h.numQuestions == 1 ? ", " : "s,", msg->h.numAnswers, msg->h.numAnswers == 1 ? ", " : "s,", msg->h.numAuthorities, msg->h.numAuthorities == 1 ? "y, " : "ies,", msg->h.numAdditionals, msg->h.numAdditionals == 1 ? " " : "s", end - msg->data); if (!InterfaceID || !m->SPSSocket || !mDNSSameIPPort(dstport, m->SPSSocket->port)) return; if (mDNS_PacketLoggingEnabled) DumpPacket(mStatus_NoError, mDNSfalse, "UDP", srcaddr, srcport, dstaddr, dstport, msg, end, InterfaceID); ptr = LocateOptRR(msg, end, DNSOpt_LeaseData_Space + DNSOpt_OwnerData_ID_Space); if (ptr) { ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_OPT) { const rdataOPT *o; const rdataOPT *const e = (const rdataOPT *)&m->rec.r.resrec.rdata->u.data[m->rec.r.resrec.rdlength]; for (o = &m->rec.r.resrec.rdata->u.opt[0]; o < e; o++) { if (o->opt == kDNSOpt_Lease) updatelease = o->u.updatelease; else if (o->opt == kDNSOpt_Owner && o->u.owner.vers == 0) owner = o->u.owner; } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } InitializeDNSMessage(&m->omsg.h, msg->h.id, UpdateRespFlags); if (!updatelease || !owner.HMAC.l[0]) { static int msgs = 0; if (msgs < 100) { msgs++; LogMsg("Refusing sleep proxy registration from %#a:%d:%s%s", srcaddr, mDNSVal16(srcport), !updatelease ? " No lease" : "", !owner.HMAC.l[0] ? " No owner" : ""); } m->omsg.h.flags.b[1] |= kDNSFlag1_RC_FormErr; } else if (m->ProxyRecords + msg->h.mDNS_numUpdates > MAX_PROXY_RECORDS) { static int msgs = 0; if (msgs < 100) { msgs++; LogMsg("Refusing sleep proxy registration from %#a:%d: Too many records %d + %d = %d > %d", srcaddr, mDNSVal16(srcport), m->ProxyRecords, msg->h.mDNS_numUpdates, m->ProxyRecords + msg->h.mDNS_numUpdates, MAX_PROXY_RECORDS); } m->omsg.h.flags.b[1] |= kDNSFlag1_RC_Refused; } else { LogSPS("Received Update for H-MAC %.6a I-MAC %.6a Password %.6a seq %d", &owner.HMAC, &owner.IMAC, &owner.password, owner.seq); if (updatelease > 24 * 60 * 60) updatelease = 24 * 60 * 60; if (updatelease > 0x40000000UL / mDNSPlatformOneSecond) updatelease = 0x40000000UL / mDNSPlatformOneSecond; ptr = LocateAuthorities(msg, end); // Clear any stale TCP keepalive records that may exist ClearKeepaliveProxyRecords(m, &owner, m->DuplicateRecords, InterfaceID); ClearKeepaliveProxyRecords(m, &owner, m->ResourceRecords, InterfaceID); for (i = 0; i < msg->h.mDNS_numUpdates && ptr && ptr < end; i++) { ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &m->rec); if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative) { mDNSu16 RDLengthMem = GetRDLengthMem(&m->rec.r.resrec); AuthRecord *ar = (AuthRecord *) mDNSPlatformMemAllocateClear(sizeof(AuthRecord) - sizeof(RDataBody) + RDLengthMem); if (!ar) { m->omsg.h.flags.b[1] |= kDNSFlag1_RC_Refused; break; } else { mDNSu8 RecordType = m->rec.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask ? kDNSRecordTypeUnique : kDNSRecordTypeShared; m->rec.r.resrec.rrclass &= ~kDNSClass_UniqueRRSet; // All stale keepalive records have been flushed prior to this loop. if (!mDNS_KeepaliveRecord(&m->rec.r.resrec)) { ClearIdenticalProxyRecords(m, &owner, m->DuplicateRecords); // Make sure we don't have any old stale duplicates of this record ClearIdenticalProxyRecords(m, &owner, m->ResourceRecords); } mDNS_SetupResourceRecord(ar, mDNSNULL, InterfaceID, m->rec.r.resrec.rrtype, m->rec.r.resrec.rroriginalttl, RecordType, AuthRecordAny, SPSRecordCallback, ar); AssignDomainName(&ar->namestorage, m->rec.r.resrec.name); ar->resrec.rdlength = GetRDLength(&m->rec.r.resrec, mDNSfalse); ar->resrec.rdata->MaxRDLength = RDLengthMem; mDNSPlatformMemCopy(ar->resrec.rdata->u.data, m->rec.r.resrec.rdata->u.data, RDLengthMem); ar->ForceMCast = mDNStrue; ar->WakeUp = owner; if (m->rec.r.resrec.rrtype == kDNSType_PTR) { mDNSs32 t = ReverseMapDomainType(m->rec.r.resrec.name); if (t == mDNSAddrType_IPv4) GetIPv4FromName(&ar->AddressProxy, m->rec.r.resrec.name); else if (t == mDNSAddrType_IPv6) GetIPv6FromName(&ar->AddressProxy, m->rec.r.resrec.name); debugf("mDNSCoreReceiveUpdate: PTR %d %d %#a %s", t, ar->AddressProxy.type, &ar->AddressProxy, ARDisplayString(m, ar)); if (ar->AddressProxy.type) SetSPSProxyListChanged(InterfaceID); } ar->TimeRcvd = m->timenow; ar->TimeExpire = m->timenow + updatelease * mDNSPlatformOneSecond; if (m->NextScheduledSPS - ar->TimeExpire > 0) m->NextScheduledSPS = ar->TimeExpire; ar->KATimeExpire = 0; mDNS_Register_internal(m, ar); m->ProxyRecords++; mDNS_UpdateAllowSleep(m); LogSPS("SPS Registered %4d %X %s", m->ProxyRecords, RecordType, ARDisplayString(m,ar)); } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } if (m->omsg.h.flags.b[1] & kDNSFlag1_RC_Mask) { LogMsg("Refusing sleep proxy registration from %#a:%d: Out of memory", srcaddr, mDNSVal16(srcport)); ClearProxyRecords(m, &owner, m->DuplicateRecords); ClearProxyRecords(m, &owner, m->ResourceRecords); } else { mDNS_SetupResourceRecord(&opt, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); opt.resrec.rrclass = NormalMaxDNSMessageData; opt.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record opt.resrec.rdestimate = sizeof(rdataOPT); opt.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease; opt.resrec.rdata->u.opt[0].u.updatelease = updatelease; p = PutResourceRecordTTLWithLimit(&m->omsg, p, &m->omsg.h.numAdditionals, &opt.resrec, opt.resrec.rroriginalttl, m->omsg.data + AbsoluteMaxDNSMessageData); } } if (p) mDNSSendDNSMessage(m, &m->omsg, p, InterfaceID, mDNSNULL, m->SPSSocket, srcaddr, srcport, mDNSNULL, mDNSfalse); mDNS_SendKeepalives(m); } mDNSlocal mDNSu32 mDNSGenerateOwnerOptForInterface(mDNS *const m, const mDNSInterfaceID InterfaceID, DNSMessage *msg) { mDNSu8 *ptr = msg->data; mDNSu8 *end = mDNSNULL; mDNSu32 length = 0; AuthRecord opt; NetworkInterfaceInfo *intf; mDNS_SetupResourceRecord(&opt, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); opt.resrec.rrclass = NormalMaxDNSMessageData; opt.resrec.rdlength = sizeof(rdataOPT); opt.resrec.rdestimate = sizeof(rdataOPT); intf = FirstInterfaceForID(m, InterfaceID); SetupOwnerOpt(m, intf, &opt.resrec.rdata->u.opt[0]); LogSPS("Generated OPT record : %s", ARDisplayString(m, &opt)); end = PutResourceRecord(msg, ptr, &msg->h.numAdditionals, &opt.resrec); if (end != mDNSNULL) { // Put all the integer values in IETF byte-order (MSB first, LSB second) SwapDNSHeaderBytes(msg); length = (mDNSu32)(end - msg->data); } else LogSPS("mDNSGenerateOwnerOptForInterface: Failed to generate owner OPT record"); return length; } // Note that this routine is called both for Sleep Proxy Registrations, and for Standard Dynamic // DNS registrations, but (currently) only has to handle the Sleep Proxy Registration reply case, // and should ignore Standard Dynamic DNS registration replies, because those are handled elsewhere. // Really, both should be unified and handled in one place. mDNSlocal void mDNSCoreReceiveUpdateR(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *end, const mDNSAddr *srcaddr, const mDNSInterfaceID InterfaceID) { if (InterfaceID) { mDNSu32 pktlease = 0, spsupdates = 0; const mDNSBool gotlease = GetPktLease(m, msg, end, &pktlease); const mDNSu32 updatelease = gotlease ? pktlease : 60 * 60; // If SPS fails to indicate lease time, assume one hour if (gotlease) LogSPS("DNS Update response contains lease option granting %4d seconds, updateid %d, InterfaceID %p", updatelease, mDNSVal16(msg->h.id), InterfaceID); if (m->CurrentRecord) LogMsg("mDNSCoreReceiveUpdateR ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { AuthRecord *const rr = m->CurrentRecord; if (rr->resrec.InterfaceID == InterfaceID || (!rr->resrec.InterfaceID && (rr->ForceMCast || IsLocalDomain(rr->resrec.name)))) if (mDNSSameOpaque16(rr->updateid, msg->h.id)) { // We successfully completed this record's registration on this "InterfaceID". Clear that bit. // Clear the updateid when we are done sending on all interfaces. mDNSu32 scopeid = mDNSPlatformInterfaceIndexfromInterfaceID(m, InterfaceID, mDNStrue); if (scopeid < (sizeof(rr->updateIntID) * mDNSNBBY)) bit_clr_opaque64(rr->updateIntID, scopeid); if (mDNSOpaque64IsZero(&rr->updateIntID)) rr->updateid = zeroID; rr->expire = NonZeroTime(m->timenow + updatelease * mDNSPlatformOneSecond); spsupdates++; LogSPS("Sleep Proxy %s record %2d %5d 0x%x 0x%x (%d) %s", rr->WakeUp.HMAC.l[0] ? "transferred" : "registered", spsupdates, updatelease, rr->updateIntID.l[1], rr->updateIntID.l[0], mDNSVal16(rr->updateid), ARDisplayString(m,rr)); if (rr->WakeUp.HMAC.l[0]) { rr->WakeUp.HMAC = zeroEthAddr; // Clear HMAC so that mDNS_Deregister_internal doesn't waste packets trying to wake this host rr->RequireGoodbye = mDNSfalse; // and we don't want to send goodbye for it mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); } } // Mustn't advance m->CurrentRecord until *after* mDNS_Deregister_internal, because // new records could have been added to the end of the list as a result of that call. if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } if (spsupdates) // Only do this dynamic store stuff if this was, in fact, a Sleep Proxy Update response { char *ifname; mDNSAddr spsaddr; DNSMessage optMsg; int length; // Update the dynamic store with the IP Address and MAC address of the sleep proxy ifname = InterfaceNameForID(m, InterfaceID); mDNSPlatformMemCopy(&spsaddr, srcaddr, sizeof (mDNSAddr)); mDNSPlatformStoreSPSMACAddr(&spsaddr, ifname); // Store the Owner OPT record for this interface. // Configd may use the OPT record if it detects a conflict with the BSP when the system wakes up InitializeDNSMessage(&optMsg.h, zeroID, ResponseFlags); length = mDNSGenerateOwnerOptForInterface(m, InterfaceID, &optMsg); if (length != 0) { length += sizeof(DNSMessageHeader); mDNSPlatformStoreOwnerOptRecord(ifname, &optMsg, length); } } } // If we were waiting to go to sleep, then this SPS registration or wide-area record deletion // may have been the thing we were waiting for, so schedule another check to see if we can sleep now. if (m->SleepLimit) m->NextScheduledSPRetry = m->timenow; } mDNSexport void MakeNegativeCacheRecord(mDNS *const m, CacheRecord *const cr, const domainname *const name, const mDNSu32 namehash, const mDNSu16 rrtype, const mDNSu16 rrclass, mDNSu32 ttl_seconds, mDNSInterfaceID InterfaceID, #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_dns_service_t service) #else DNSServer *dnsserver) #endif { if (cr == &m->rec.r && m->rec.r.resrec.RecordType) LogFatalError("MakeNegativeCacheRecord: m->rec appears to be already in use for %s", CRDisplayString(m, &m->rec.r)); // Create empty resource record cr->resrec.RecordType = kDNSRecordTypePacketNegative; cr->resrec.InterfaceID = InterfaceID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_replace(&cr->resrec.dnsservice, service); #else cr->resrec.rDNSServer = dnsserver; #endif cr->resrec.name = name; // Will be updated to point to cg->name when we call CreateNewCacheEntry cr->resrec.rrtype = rrtype; cr->resrec.rrclass = rrclass; cr->resrec.rroriginalttl = ttl_seconds; cr->resrec.rdlength = 0; cr->resrec.rdestimate = 0; cr->resrec.namehash = namehash; cr->resrec.rdatahash = 0; cr->resrec.rdata = (RData*)&cr->smallrdatastorage; cr->resrec.rdata->MaxRDLength = 0; cr->NextInKAList = mDNSNULL; cr->TimeRcvd = m->timenow; cr->DelayDelivery = 0; cr->NextRequiredQuery = m->timenow; #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) cr->LastCachedAnswerTime= 0; #endif cr->CRActiveQuestion = mDNSNULL; cr->UnansweredQueries = 0; cr->LastUnansweredTime = 0; cr->NextInCFList = mDNSNULL; cr->soa = mDNSNULL; // Initialize to the basic one and the caller can set it to more // specific based on the response if any cr->responseFlags = ResponseFlags; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSexport void mDNSCoreReceiveForQuerier(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, mdns_querier_t querier, mdns_dns_service_t dnsservice) { SwapDNSHeaderBytes(msg); mDNS_Lock(m); mDNSCoreReceiveResponse(m, msg, end, mDNSNULL, zeroIPPort, mDNSNULL, zeroIPPort, querier, dnsservice, mDNSNULL); mDNS_Unlock(m); } #endif mDNSexport void mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID) { mDNSInterfaceID ifid = InterfaceID; const mDNSu8 *const pkt = (mDNSu8 *)msg; const mDNSu8 StdQ = kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery; const mDNSu8 StdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery; const mDNSu8 UpdQ = kDNSFlag0_QR_Query | kDNSFlag0_OP_Update; const mDNSu8 UpdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_Update; mDNSu8 QR_OP; mDNSu8 *ptr = mDNSNULL; mDNSBool TLS = (dstaddr == (mDNSAddr *)1); // For debug logs: dstaddr = 0 means TCP; dstaddr = 1 means TLS if (TLS) dstaddr = mDNSNULL; #ifndef UNICAST_DISABLED if (mDNSSameAddress(srcaddr, &m->Router)) { #ifdef _LEGACY_NAT_TRAVERSAL_ if (mDNSSameIPPort(srcport, SSDPPort) || (m->SSDPSocket && mDNSSameIPPort(dstport, m->SSDPSocket->port))) { mDNS_Lock(m); LNT_ConfigureRouterInfo(m, InterfaceID, (mDNSu8 *)msg, (mDNSu16)(end - pkt)); mDNS_Unlock(m); return; } #endif if (mDNSSameIPPort(srcport, NATPMPPort)) { mDNS_Lock(m); uDNS_ReceiveNATPacket(m, InterfaceID, (mDNSu8 *)msg, (mDNSu16)(end - pkt)); mDNS_Unlock(m); return; } } #ifdef _LEGACY_NAT_TRAVERSAL_ else if (m->SSDPSocket && mDNSSameIPPort(dstport, m->SSDPSocket->port)) { debugf("Ignoring SSDP response from %#a:%d", srcaddr, mDNSVal16(srcport)); return; } #endif #endif if ((unsigned)(end - pkt) < sizeof(DNSMessageHeader)) { LogMsg("DNS Message from %#a:%d to %#a:%d length %d too short", srcaddr, mDNSVal16(srcport), dstaddr, mDNSVal16(dstport), (int)(end - pkt)); return; } QR_OP = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask); // Read the integer parts which are in IETF byte-order (MSB first, LSB second) ptr = (mDNSu8 *)&msg->h.numQuestions; msg->h.numQuestions = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); msg->h.numAnswers = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); msg->h.numAuthorities = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]); msg->h.numAdditionals = (mDNSu16)((mDNSu16)ptr[6] << 8 | ptr[7]); if (!m) { LogMsg("mDNSCoreReceive ERROR m is NULL"); return; } // We use zero addresses and all-ones addresses at various places in the code to indicate special values like "no address" // If we accept and try to process a packet with zero or all-ones source address, that could really mess things up if (!mDNSAddressIsValid(srcaddr)) { debugf("mDNSCoreReceive ignoring packet from %#a", srcaddr); return; } mDNS_Lock(m); m->PktNum++; if (mDNSOpaque16IsZero(msg->h.id)) { m->MPktNum++; #if APPLE_OSX_mDNSResponder // Track the number of multicast packets received from a source outside our subnet. // Check the destination address to avoid accounting for spurious packets that // comes in with message id zero. if (!mDNS_AddressIsLocalSubnet(m, InterfaceID, srcaddr) && dstaddr && mDNSAddressIsAllDNSLinkGroup(dstaddr)) { m->RemoteSubnet++; } #endif // #if APPLE_OSX_mDNSResponder } #ifndef UNICAST_DISABLED if (!dstaddr || (!mDNSAddressIsAllDNSLinkGroup(dstaddr) && (QR_OP == StdR || QR_OP == UpdR))) if (!mDNSOpaque16IsZero(msg->h.id)) // uDNS_ReceiveMsg only needs to get real uDNS responses, not "QU" mDNS responses { ifid = mDNSInterface_Any; if (mDNS_PacketLoggingEnabled) DumpPacket(mStatus_NoError, mDNSfalse, TLS ? "TLS" : !dstaddr ? "TCP" : "UDP", srcaddr, srcport, dstaddr, dstport, msg, end, InterfaceID); uDNS_ReceiveMsg(m, msg, end, srcaddr, srcport); // Note: mDNSCore also needs to get access to received unicast responses } #endif if (QR_OP == StdQ) mDNSCoreReceiveQuery (m, msg, end, srcaddr, srcport, dstaddr, dstport, ifid); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) else if (QR_OP == StdR) mDNSCoreReceiveResponse(m, msg, end, srcaddr, srcport, dstaddr, dstport, mDNSNULL, mDNSNULL, ifid); #else else if (QR_OP == StdR) mDNSCoreReceiveResponse(m, msg, end, srcaddr, srcport, dstaddr, dstport, ifid); #endif else if (QR_OP == UpdQ) mDNSCoreReceiveUpdate (m, msg, end, srcaddr, srcport, dstaddr, dstport, InterfaceID); else if (QR_OP == UpdR) mDNSCoreReceiveUpdateR (m, msg, end, srcaddr, InterfaceID); else { if (mDNS_LoggingEnabled) { static int msgCount = 0; if (msgCount < 1000) { int i = 0; msgCount++; LogInfo("Unknown DNS packet type %02X%02X from %#-15a:%-5d to %#-15a:%-5d length %d on %p (ignored)", msg->h.flags.b[0], msg->h.flags.b[1], srcaddr, mDNSVal16(srcport), dstaddr, mDNSVal16(dstport), (int)(end - pkt), InterfaceID); while (i < (int)(end - pkt)) { char buffer[128]; char *p = buffer + mDNS_snprintf(buffer, sizeof(buffer), "%04X", i); do if (i < (int)(end - pkt)) p += mDNS_snprintf(p, sizeof(buffer), " %02X", pkt[i]);while (++i & 15); LogInfo("%s", buffer); } } } } // Packet reception often causes a change to the task list: // 1. Inbound queries can cause us to need to send responses // 2. Conflicing response packets received from other hosts can cause us to need to send defensive responses // 3. Other hosts announcing deletion of shared records can cause us to need to re-assert those records // 4. Response packets that answer questions may cause our client to issue new questions mDNS_Unlock(m); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Searcher Functions #endif // Note: We explicitly disallow making a public query be a duplicate of a private one. This is to avoid the // circular deadlock where a client does a query for something like "dns-sd -Q _dns-query-tls._tcp.company.com SRV" // and we have a key for company.com, so we try to locate the private query server for company.com, which necessarily entails // doing a standard DNS query for the _dns-query-tls._tcp SRV record for company.com. If we make the latter (public) query // a duplicate of the former (private) query, then it will block forever waiting for an answer that will never come. // // We keep SuppressUnusable questions separate so that we can return a quick response to them and not get blocked behind // the queries that are not marked SuppressUnusable. But if the query is not suppressed, they are treated the same as // non-SuppressUnusable questions. This should be fine as the goal of SuppressUnusable is to return quickly only if it // is suppressed. If it is not suppressed, we do try all the DNS servers for valid answers like any other question. // The main reason for this design is that cache entries point to a *single* question and that question is responsible // for keeping the cache fresh as long as it is active. Having multiple active question for a single cache entry // breaks this design principle. // // If IsLLQ(Q) is true, it means the question is both: // (a) long-lived and // (b) being performed by a unicast DNS long-lived query (either full LLQ, or polling) // for multicast questions, we don't want to treat LongLived as anything special #define IsLLQ(Q) ((Q)->LongLived && !mDNSOpaque16IsZero((Q)->TargetQID)) #define AWDLIsIncluded(Q) (((Q)->flags & kDNSServiceFlagsIncludeAWDL) != 0) #define SameQuestionKind(Q1, Q2) (mDNSOpaque16IsZero((Q1)->TargetQID) == mDNSOpaque16IsZero((Q2)->TargetQID)) mDNSlocal DNSQuestion *FindDuplicateQuestion(const mDNS *const m, const DNSQuestion *const question) { DNSQuestion *q; // Note: A question can only be marked as a duplicate of one that occurs *earlier* in the list. // This prevents circular references, where two questions are each marked as a duplicate of the other. // Accordingly, we break out of the loop when we get to 'question', because there's no point searching // further in the list. for (q = m->Questions; q && (q != question); q = q->next) { if (!SameQuestionKind(q, question)) continue; if (q->qnamehash != question->qnamehash) continue; if (q->InterfaceID != question->InterfaceID) continue; if (q->qtype != question->qtype) continue; if (q->qclass != question->qclass) continue; if (IsLLQ(q) != IsLLQ(question)) continue; if (q->AuthInfo && !question->AuthInfo) continue; if (!q->Suppressed != !question->Suppressed) continue; if (q->BrowseThreshold != question->BrowseThreshold) continue; if (AWDLIsIncluded(q) != AWDLIsIncluded(question)) continue; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (q->dnsservice != question->dnsservice) continue; #endif if (!SameDomainName(&q->qname, &question->qname)) continue; return(q); } return(mDNSNULL); } // This is called after a question is deleted, in case other identical questions were being suppressed as duplicates mDNSlocal void UpdateQuestionDuplicates(mDNS *const m, DNSQuestion *const question) { DNSQuestion *q; DNSQuestion *first = mDNSNULL; // This is referring to some other question as duplicate. No other question can refer to this // question as a duplicate. if (question->DuplicateOf) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%d->DupQ%d->Q%d] UpdateQuestionDuplicates: question %p " PRI_DM_NAME " (" PUB_S ") duplicate of %p " PRI_DM_NAME " (" PUB_S ")", question->request_id, mDNSVal16(question->TargetQID), mDNSVal16(question->DuplicateOf->TargetQID), question, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype), question->DuplicateOf, DM_NAME_PARAM(&question->DuplicateOf->qname), DNSTypeName(question->DuplicateOf->qtype)); return; } for (q = m->Questions; q; q=q->next) // Scan our list of questions if (q->DuplicateOf == question) // To see if any questions were referencing this as their duplicate { q->DuplicateOf = first; if (!first) { first = q; // If q used to be a duplicate, but now is not, // then inherit the state from the question that's going away q->LastQTime = question->LastQTime; q->ThisQInterval = question->ThisQInterval; q->ExpectUnicastResp = question->ExpectUnicastResp; q->LastAnswerPktNum = question->LastAnswerPktNum; q->RecentAnswerPkts = question->RecentAnswerPkts; q->RequestUnicast = question->RequestUnicast; q->LastQTxTime = question->LastQTxTime; q->CNAMEReferrals = question->CNAMEReferrals; q->nta = question->nta; q->servAddr = question->servAddr; q->servPort = question->servPort; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_replace(&q->dnsservice, question->dnsservice); mdns_forget(&question->dnsservice); mdns_querier_forget(&q->querier); mdns_replace(&q->querier, question->querier); mdns_forget(&question->querier); #else q->qDNSServer = question->qDNSServer; q->validDNSServers = question->validDNSServers; q->unansweredQueries = question->unansweredQueries; q->noServerResponse = question->noServerResponse; q->triedAllServersOnce = question->triedAllServersOnce; #endif q->TargetQID = question->TargetQID; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) q->LocalSocket = question->LocalSocket; // No need to close old q->LocalSocket first -- duplicate questions can't have their own sockets #endif q->state = question->state; // q->tcp = question->tcp; q->ReqLease = question->ReqLease; q->expire = question->expire; q->ntries = question->ntries; q->id = question->id; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) question->LocalSocket = mDNSNULL; #endif question->nta = mDNSNULL; // If we've got a GetZoneData in progress, transfer it to the newly active question // question->tcp = mDNSNULL; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (q->LocalSocket) debugf("UpdateQuestionDuplicates transferred LocalSocket pointer for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); #endif if (q->nta) { LogInfo("UpdateQuestionDuplicates transferred nta pointer for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); q->nta->ZoneDataContext = q; } // Need to work out how to safely transfer this state too -- appropriate context pointers need to be updated or the code will crash if (question->tcp) LogInfo("UpdateQuestionDuplicates did not transfer tcp pointer"); if (question->state == LLQ_Established) { LogInfo("UpdateQuestionDuplicates transferred LLQ state for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); question->state = 0; // Must zero question->state, or mDNS_StopQuery_internal will clean up and cancel our LLQ from the server } SetNextQueryTime(m,q); } } } mDNSexport McastResolver *mDNS_AddMcastResolver(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, mDNSu32 timeout) { McastResolver **p = &m->McastResolvers; McastResolver *tmp = mDNSNULL; if (!d) d = (const domainname *)""; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "mDNS_AddMcastResolver: Adding " PUB_DM_NAME ", InterfaceID %p, timeout %u", DM_NAME_PARAM(d), interface, timeout); mDNS_CheckLock(m); while (*p) // Check if we already have this {interface, domain} tuple registered { if ((*p)->interface == interface && SameDomainName(&(*p)->domain, d)) { if (!((*p)->flags & McastResolver_FlagDelete)) LogMsg("Note: Mcast Resolver domain %##s (%p) registered more than once", d->c, interface); (*p)->flags &= ~McastResolver_FlagDelete; tmp = *p; *p = tmp->next; tmp->next = mDNSNULL; } else p=&(*p)->next; } if (tmp) *p = tmp; // move to end of list, to ensure ordering from platform layer else { // allocate, add to list *p = (McastResolver *) mDNSPlatformMemAllocateClear(sizeof(**p)); if (!*p) LogMsg("mDNS_AddMcastResolver: ERROR!! - malloc"); else { (*p)->interface = interface; (*p)->flags = McastResolver_FlagNew; (*p)->timeout = timeout; AssignDomainName(&(*p)->domain, d); (*p)->next = mDNSNULL; } } return(*p); } #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSinline mDNSs32 PenaltyTimeForServer(mDNS *m, DNSServer *server) { mDNSs32 ptime = 0; if (server->penaltyTime != 0) { ptime = server->penaltyTime - m->timenow; if (ptime < 0) { // This should always be a positive value between 0 and DNSSERVER_PENALTY_TIME // If it does not get reset in ResetDNSServerPenalties for some reason, we do it // here LogMsg("PenaltyTimeForServer: PenaltyTime negative %d, (server penaltyTime %d, timenow %d) resetting the penalty", ptime, server->penaltyTime, m->timenow); server->penaltyTime = 0; ptime = 0; } } return ptime; } #endif //Checks to see whether the newname is a better match for the name, given the best one we have //seen so far (given in bestcount). //Returns -1 if the newname is not a better match //Returns 0 if the newname is the same as the old match //Returns 1 if the newname is a better match mDNSlocal int BetterMatchForName(const domainname *name, int namecount, const domainname *newname, int newcount, int bestcount) { // If the name contains fewer labels than the new server's domain or the new name // contains fewer labels than the current best, then it can't possibly be a better match if (namecount < newcount || newcount < bestcount) return -1; // If there is no match, return -1 and the caller will skip this newname for // selection // // If we find a match and the number of labels is the same as bestcount, then // we return 0 so that the caller can do additional logic to pick one of // the best based on some other factors e.g., penaltyTime // // If we find a match and the number of labels is more than bestcount, then we // return 1 so that the caller can pick this over the old one. // // Note: newcount can either be equal or greater than bestcount beause of the // check above. if (SameDomainName(SkipLeadingLabels(name, namecount - newcount), newname)) return bestcount == newcount ? 0 : 1; else return -1; } // Normally, we have McastResolvers for .local, in-addr.arpa and ip6.arpa. But there // can be queries that can forced to multicast (ForceMCast) even though they don't end in these // names. In that case, we give a default timeout of 5 seconds #define DEFAULT_MCAST_TIMEOUT 5 mDNSlocal mDNSu32 GetTimeoutForMcastQuestion(mDNS *m, DNSQuestion *question) { McastResolver *curmatch = mDNSNULL; int bestmatchlen = -1, namecount = CountLabels(&question->qname); McastResolver *curr; int bettermatch, currcount; for (curr = m->McastResolvers; curr; curr = curr->next) { currcount = CountLabels(&curr->domain); bettermatch = BetterMatchForName(&question->qname, namecount, &curr->domain, currcount, bestmatchlen); // Take the first best match. If there are multiple equally good matches (bettermatch = 0), we take // the timeout value from the first one if (bettermatch == 1) { curmatch = curr; bestmatchlen = currcount; } } LogInfo("GetTimeoutForMcastQuestion: question %##s curmatch %p, Timeout %d", question->qname.c, curmatch, curmatch ? curmatch->timeout : DEFAULT_MCAST_TIMEOUT); return ( curmatch ? curmatch->timeout : DEFAULT_MCAST_TIMEOUT); } // Returns true if it is a Domain Enumeration Query mDNSexport mDNSBool DomainEnumQuery(const domainname *qname) { const mDNSu8 *mDNS_DEQLabels[] = { (const mDNSu8 *)"\001b", (const mDNSu8 *)"\002db", (const mDNSu8 *)"\002lb", (const mDNSu8 *)"\001r", (const mDNSu8 *)"\002dr", (const mDNSu8 *)mDNSNULL, }; const domainname *d = qname; const mDNSu8 *label; int i = 0; // We need at least 3 labels (DEQ prefix) + one more label to make a meaningful DE query if (CountLabels(qname) < 4) { debugf("DomainEnumQuery: question %##s, not enough labels", qname->c); return mDNSfalse; } label = (const mDNSu8 *)d; while (mDNS_DEQLabels[i] != (const mDNSu8 *)mDNSNULL) { if (SameDomainLabel(mDNS_DEQLabels[i], label)) {debugf("DomainEnumQuery: DEQ %##s, label1 match", qname->c); break;} i++; } if (mDNS_DEQLabels[i] == (const mDNSu8 *)mDNSNULL) { debugf("DomainEnumQuery: Not a DEQ %##s, label1 mismatch", qname->c); return mDNSfalse; } debugf("DomainEnumQuery: DEQ %##s, label1 match", qname->c); // CountLabels already verified the number of labels d = (const domainname *)(d->c + 1 + d->c[0]); // Second Label label = (const mDNSu8 *)d; if (!SameDomainLabel(label, (const mDNSu8 *)"\007_dns-sd")) { debugf("DomainEnumQuery: Not a DEQ %##s, label2 mismatch", qname->c); return(mDNSfalse); } debugf("DomainEnumQuery: DEQ %##s, label2 match", qname->c); d = (const domainname *)(d->c + 1 + d->c[0]); // Third Label label = (const mDNSu8 *)d; if (!SameDomainLabel(label, (const mDNSu8 *)"\004_udp")) { debugf("DomainEnumQuery: Not a DEQ %##s, label3 mismatch", qname->c); return(mDNSfalse); } debugf("DomainEnumQuery: DEQ %##s, label3 match", qname->c); debugf("DomainEnumQuery: Question %##s is a Domain Enumeration query", qname->c); return mDNStrue; } #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) // Note: InterfaceID is the InterfaceID of the question mDNSlocal mDNSBool DNSServerMatch(DNSServer *d, mDNSInterfaceID InterfaceID, mDNSs32 ServiceID) { // 1) Unscoped questions (NULL InterfaceID) should consider *only* unscoped DNSServers ( DNSServer // with scopeType set to kScopeNone) // // 2) Scoped questions (non-NULL InterfaceID) should consider *only* scoped DNSServers (DNSServer // with scopeType set to kScopeInterfaceID) and their InterfaceIDs should match. // // 3) Scoped questions (non-zero ServiceID) should consider *only* scoped DNSServers (DNSServer // with scopeType set to kScopeServiceID) and their ServiceIDs should match. // // The first condition in the "if" statement checks to see if both the question and the DNSServer are // unscoped. The question is unscoped only if InterfaceID is zero and ServiceID is -1. // // If the first condition fails, following are the possible cases (the notes below are using // InterfaceID for discussion and the same holds good for ServiceID): // // - DNSServer is not scoped, InterfaceID is not NULL - we should skip the current DNSServer entry // as scoped questions should not pick non-scoped DNSServer entry (Refer to (2) above). // // - DNSServer is scoped, InterfaceID is NULL - we should skip the current DNSServer entry as // unscoped question should not match scoped DNSServer (Refer to (1) above). The InterfaceID check // would fail in this case. // // - DNSServer is scoped and InterfaceID is not NULL - the InterfaceID of the question and the DNSServer // should match (Refer to (2) above). if (((d->scopeType == kScopeNone) && (!InterfaceID && ServiceID == -1)) || ((d->scopeType == kScopeInterfaceID) && d->interface == InterfaceID) || ((d->scopeType == kScopeServiceID) && d->serviceID == ServiceID)) { return mDNStrue; } return mDNSfalse; } // Sets all the Valid DNS servers for a question mDNSexport mDNSu32 SetValidDNSServers(mDNS *m, DNSQuestion *question) { int bestmatchlen = -1, namecount = CountLabels(&question->qname); DNSServer *curr; int bettermatch, currcount; int index = 0; mDNSu32 timeout = 0; mDNSBool DEQuery; question->validDNSServers = zeroOpaque128; DEQuery = DomainEnumQuery(&question->qname); for (curr = m->DNSServers; curr; curr = curr->next) { debugf("SetValidDNSServers: Parsing DNS server Address %#a (Domain %##s), Scope: %d", &curr->addr, curr->domain.c, curr->scopeType); // skip servers that will soon be deleted if (curr->flags & DNSServerFlag_Delete) { debugf("SetValidDNSServers: Delete set for index %d, DNS server %#a (Domain %##s), scoped %d", index, &curr->addr, curr->domain.c, curr->scopeType); continue; } // This happens normally when you unplug the interface where we reset the interfaceID to mDNSInterface_Any for all // the DNS servers whose scope match the interfaceID. Few seconds later, we also receive the updated DNS configuration. // But any questions that has mDNSInterface_Any scope that are started/restarted before we receive the update // (e.g., CheckSuppressUnusableQuestions is called when interfaces are deregistered with the core) should not // match the scoped entries by mistake. // // Note: DNS configuration change will help pick the new dns servers but currently it does not affect the timeout // Skip DNSServers that are InterfaceID Scoped but have no valid interfaceid set OR DNSServers that are ServiceID Scoped but have no valid serviceid set if (((curr->scopeType == kScopeInterfaceID) && (curr->interface == mDNSInterface_Any)) || ((curr->scopeType == kScopeServiceID) && (curr->serviceID <= 0))) { LogInfo("SetValidDNSServers: ScopeType[%d] Skipping DNS server %#a (Domain %##s) Interface:[%p] Serviceid:[%d]", (int)curr->scopeType, &curr->addr, curr->domain.c, curr->interface, curr->serviceID); continue; } currcount = CountLabels(&curr->domain); if ((!DEQuery || !curr->isCell) && DNSServerMatch(curr, question->InterfaceID, question->ServiceID)) { bettermatch = BetterMatchForName(&question->qname, namecount, &curr->domain, currcount, bestmatchlen); // If we found a better match (bettermatch == 1) then clear all the bits // corresponding to the old DNSServers that we have may set before and start fresh. // If we find an equal match, then include that DNSServer also by setting the corresponding // bit if ((bettermatch == 1) || (bettermatch == 0)) { bestmatchlen = currcount; if (bettermatch) { debugf("SetValidDNSServers: Resetting all the bits"); question->validDNSServers = zeroOpaque128; timeout = 0; } debugf("SetValidDNSServers: question %##s Setting the bit for DNS server Address %#a (Domain %##s), Scoped:%d index %d," " Timeout %d, interface %p", question->qname.c, &curr->addr, curr->domain.c, curr->scopeType, index, curr->timeout, curr->interface); timeout += curr->timeout; if (DEQuery) debugf("DomainEnumQuery: Question %##s, DNSServer %#a, cell %d", question->qname.c, &curr->addr, curr->isCell); bit_set_opaque128(question->validDNSServers, index); } } index++; } question->noServerResponse = 0; debugf("SetValidDNSServers: ValidDNSServer bits 0x%08x%08x%08x%08x for question %p %##s (%s)", question->validDNSServers.l[3], question->validDNSServers.l[2], question->validDNSServers.l[1], question->validDNSServers.l[0], question, question->qname.c, DNSTypeName(question->qtype)); // If there are no matching resolvers, then use the default timeout value. return (timeout ? timeout : DEFAULT_UDNS_TIMEOUT); } // Get the Best server that matches a name. If you find penalized servers, look for the one // that will come out of the penalty box soon mDNSlocal DNSServer *GetBestServer(mDNS *m, const domainname *name, mDNSInterfaceID InterfaceID, mDNSs32 ServiceID, mDNSOpaque128 validBits, int *selected, mDNSBool nameMatch) { DNSServer *curmatch = mDNSNULL; int bestmatchlen = -1, namecount = name ? CountLabels(name) : 0; DNSServer *curr; mDNSs32 bestPenaltyTime, currPenaltyTime; int bettermatch, currcount; int index = 0; int currindex = -1; debugf("GetBestServer: ValidDNSServer bits 0x%x%x", validBits.l[1], validBits.l[0]); bestPenaltyTime = DNSSERVER_PENALTY_TIME + 1; for (curr = m->DNSServers; curr; curr = curr->next) { // skip servers that will soon be deleted if (curr->flags & DNSServerFlag_Delete) { debugf("GetBestServer: Delete set for index %d, DNS server %#a (Domain %##s), scoped %d", index, &curr->addr, curr->domain.c, curr->scopeType); continue; } // Check if this is a valid DNSServer if (!bit_get_opaque64(validBits, index)) { debugf("GetBestServer: continuing for index %d", index); index++; continue; } currcount = CountLabels(&curr->domain); currPenaltyTime = PenaltyTimeForServer(m, curr); debugf("GetBestServer: Address %#a (Domain %##s), PenaltyTime(abs) %d, PenaltyTime(rel) %d", &curr->addr, curr->domain.c, curr->penaltyTime, currPenaltyTime); // If there are multiple best servers for a given question, we will pick the first one // if none of them are penalized. If some of them are penalized in that list, we pick // the least penalized one. BetterMatchForName walks through all best matches and // "currPenaltyTime < bestPenaltyTime" check lets us either pick the first best server // in the list when there are no penalized servers and least one among them // when there are some penalized servers. if (DNSServerMatch(curr, InterfaceID, ServiceID)) { // If we know that all the names are already equally good matches, then skip calling BetterMatchForName. // This happens when we initially walk all the DNS servers and set the validity bit on the question. // Actually we just need PenaltyTime match, but for the sake of readability we just skip the expensive // part and still do some redundant steps e.g., InterfaceID match if (nameMatch) bettermatch = BetterMatchForName(name, namecount, &curr->domain, currcount, bestmatchlen); else bettermatch = 0; // If we found a better match (bettermatch == 1) then we don't need to // compare penalty times. But if we found an equal match, then we compare // the penalty times to pick a better match if ((bettermatch == 1) || ((bettermatch == 0) && currPenaltyTime < bestPenaltyTime)) { currindex = index; curmatch = curr; bestmatchlen = currcount; bestPenaltyTime = currPenaltyTime; } } index++; } if (selected) *selected = currindex; return curmatch; } // Look up a DNS Server, matching by name and InterfaceID mDNSlocal DNSServer *GetServerForName(mDNS *m, const domainname *name, mDNSInterfaceID InterfaceID, mDNSs32 ServiceID) { DNSServer *curmatch = mDNSNULL; char *ifname = mDNSNULL; // for logging purposes only mDNSOpaque128 allValid; if (InterfaceID == mDNSInterface_LocalOnly) InterfaceID = mDNSNULL; if (InterfaceID) ifname = InterfaceNameForID(m, InterfaceID); // By passing in all ones, we make sure that every DNS server is considered allValid.l[0] = allValid.l[1] = allValid.l[2] = allValid.l[3] = 0xFFFFFFFF; curmatch = GetBestServer(m, name, InterfaceID, ServiceID, allValid, mDNSNULL, mDNStrue); if (curmatch != mDNSNULL) LogInfo("GetServerForName: DNS server %#a:%d (Penalty Time Left %d) (Scope %s:%p) for %##s", &curmatch->addr, mDNSVal16(curmatch->port), (curmatch->penaltyTime ? (curmatch->penaltyTime - m->timenow) : 0), ifname ? ifname : "None", InterfaceID, name); else LogInfo("GetServerForName: no DNS server (Scope %s:%p) for %##s", ifname ? ifname : "None", InterfaceID, name); return(curmatch); } // Look up a DNS Server for a question within its valid DNSServer bits mDNSexport DNSServer *GetServerForQuestion(mDNS *m, DNSQuestion *question) { DNSServer *curmatch = mDNSNULL; char *ifname = mDNSNULL; // for logging purposes only mDNSInterfaceID InterfaceID = question->InterfaceID; const domainname *name = &question->qname; int currindex; if (InterfaceID == mDNSInterface_LocalOnly) InterfaceID = mDNSNULL; if (InterfaceID) ifname = InterfaceNameForID(m, InterfaceID); if (!mDNSOpaque128IsZero(&question->validDNSServers)) { curmatch = GetBestServer(m, name, InterfaceID, question->ServiceID, question->validDNSServers, &currindex, mDNSfalse); if (currindex != -1) bit_clr_opaque128(question->validDNSServers, currindex); } if (curmatch != mDNSNULL) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] GetServerForQuestion: %p DNS server (%p) " PRI_IP_ADDR ":%d (Penalty Time Left %d) (Scope " PUB_S ":%p:%d) for " PRI_DM_NAME " (" PUB_S ")", question->request_id, mDNSVal16(question->TargetQID), question, curmatch, &curmatch->addr, mDNSVal16(curmatch->port), (curmatch->penaltyTime ? (curmatch->penaltyTime - m->timenow) : 0), ifname ? ifname : "None", InterfaceID, question->ServiceID, DM_NAME_PARAM(name), DNSTypeName(question->qtype)); } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] GetServerForQuestion: %p no DNS server (Scope " PUB_S ":%p:%d) for " PRI_DM_NAME " (" PUB_S ")", question->request_id, mDNSVal16(question->TargetQID), question, ifname ? ifname : "None", InterfaceID, question->ServiceID, DM_NAME_PARAM(name), DNSTypeName(question->qtype)); } return(curmatch); } #endif // MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) // Called in normal client context (lock not held) mDNSlocal void LLQNATCallback(mDNS *m, NATTraversalInfo *n) { DNSQuestion *q; mDNS_Lock(m); LogInfo("LLQNATCallback external address:port %.4a:%u, NAT result %d", &n->ExternalAddress, mDNSVal16(n->ExternalPort), n->Result); n->clientContext = mDNSNULL; // we received at least one callback since starting this NAT-T for (q = m->Questions; q; q=q->next) if (ActiveQuestion(q) && !mDNSOpaque16IsZero(q->TargetQID) && q->LongLived) startLLQHandshake(m, q); // If ExternalPort is zero, will do StartLLQPolling instead mDNS_Unlock(m); } // This function takes the DNSServer as a separate argument because sometimes the // caller has not yet assigned the DNSServer, but wants to evaluate the Suppressed // status before switching to it. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSexport mDNSBool ShouldSuppressUnicastQuery(const DNSQuestion *const q, const mdns_dns_service_t dnsservice) #else mDNSlocal mDNSBool ShouldSuppressUnicastQuery(const DNSQuestion *const q, const DNSServer *const server) #endif { mDNSBool suppress = mDNSfalse; const char *reason = mDNSNULL; if (q->BlockedByPolicy) { suppress = mDNStrue; reason = " (blocked by policy)"; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) else if (!dnsservice) { if (!q->IsUnicastDotLocal) { suppress = mDNStrue; reason = " (no DNS service)"; } } #else else if (!server) { if (!q->IsUnicastDotLocal) { suppress = mDNStrue; reason = " (no DNS server)"; } } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) else if ((q->flags & kDNSServiceFlagsDenyCellular) && mdns_dns_service_interface_is_cellular(dnsservice)) #else else if ((q->flags & kDNSServiceFlagsDenyCellular) && server->isCell) #endif { suppress = mDNStrue; reason = " (interface is cellular)"; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) else if ((q->flags & kDNSServiceFlagsDenyExpensive) && mdns_dns_service_interface_is_expensive(dnsservice)) #else else if ((q->flags & kDNSServiceFlagsDenyExpensive) && server->isExpensive) #endif { suppress = mDNStrue; reason = " (interface is expensive)"; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) else if ((q->flags & kDNSServiceFlagsDenyConstrained) && mdns_dns_service_interface_is_constrained(dnsservice)) #else else if ((q->flags & kDNSServiceFlagsDenyConstrained) && server->isConstrained) #endif { suppress = mDNStrue; reason = " (interface is constrained)"; } #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) else if (q->SuppressUnusable && !DNS64IsQueryingARecord(q->dns64.state)) #else else if (q->SuppressUnusable) #endif { if (q->qtype == kDNSType_A) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!mdns_dns_service_a_queries_advised(dnsservice)) #else if (!server->usableA) #endif { suppress = mDNStrue; reason = " (A records are unusable)"; } // If the server's configuration allows A record queries, suppress this query if // 1. the interface associated with the server is CLAT46; and // 2. the query has the kDNSServiceFlagsPathEvaluationDone flag, indicating that it's from libnetwork. // See for more info. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) else if ((q->flags & kDNSServiceFlagsPathEvaluationDone) && mdns_dns_service_interface_is_clat46(dnsservice)) #else else if ((q->flags & kDNSServiceFlagsPathEvaluationDone) && server->isCLAT46) #endif { suppress = mDNStrue; reason = " (CLAT46 A records are unusable)"; } } else if (q->qtype == kDNSType_AAAA) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!mdns_dns_service_aaaa_queries_advised(dnsservice)) #else if (!server->usableAAAA) #endif { suppress = mDNStrue; reason = " (AAAA records are unusable)"; } } } if (suppress) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[Q%u] ShouldSuppressUnicastQuery: Query suppressed for " PRI_DM_NAME " " PUB_S PUB_S, mDNSVal16(q->TargetQID), DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), reason ? reason : ""); } return suppress; } mDNSlocal mDNSBool ShouldSuppressQuery(DNSQuestion *q) { // Multicast queries are never suppressed. if (mDNSOpaque16IsZero(q->TargetQID)) { return mDNSfalse; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) return (ShouldSuppressUnicastQuery(q, q->dnsservice)); #else return (ShouldSuppressUnicastQuery(q, q->qDNSServer)); #endif } mDNSlocal void CacheRecordRmvEventsForCurrentQuestion(mDNS *const m, DNSQuestion *q) { CacheRecord *cr; CacheGroup *cg; cg = CacheGroupForName(m, q->qnamehash, &q->qname); for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { // Don't deliver RMV events for negative records if (cr->resrec.RecordType == kDNSRecordTypePacketNegative) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] CacheRecordRmvEventsForCurrentQuestion: CacheRecord " PRI_S " Suppressing RMV events for question %p " PRI_DM_NAME " (" PUB_S "), CRActiveQuestion %p, CurrentAnswers %d", q->request_id, mDNSVal16(q->TargetQID), CRDisplayString(m, cr), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), cr->CRActiveQuestion, q->CurrentAnswers); continue; } if (SameNameCacheRecordAnswersQuestion(cr, q)) { LogInfo("CacheRecordRmvEventsForCurrentQuestion: Calling AnswerCurrentQuestionWithResourceRecord (RMV) for question %##s using resource record %s LocalAnswers %d", q->qname.c, CRDisplayString(m, cr), q->LOAddressAnswers); q->CurrentAnswers--; if (cr->resrec.rdlength > SmallRecordLimit) q->LargeAnswers--; if (cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) q->UniqueAnswers--; AnswerCurrentQuestionWithResourceRecord(m, cr, QC_rmv); if (m->CurrentQuestion != q) break; // If callback deleted q, then we're finished here } } } mDNSlocal mDNSBool IsQuestionNew(mDNS *const m, DNSQuestion *question) { DNSQuestion *q; for (q = m->NewQuestions; q; q = q->next) if (q == question) return mDNStrue; return mDNSfalse; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSexport mDNSBool LocalRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q) #else mDNSlocal mDNSBool LocalRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q) #endif { AuthRecord *rr; AuthGroup *ag; if (m->CurrentQuestion) LogMsg("LocalRecordRmvEventsForQuestion: ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); if (IsQuestionNew(m, q)) { LogInfo("LocalRecordRmvEventsForQuestion: New Question %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return mDNStrue; } m->CurrentQuestion = q; ag = AuthGroupForName(&m->rrauth, q->qnamehash, &q->qname); if (ag) { for (rr = ag->members; rr; rr=rr->next) // Filter the /etc/hosts records - LocalOnly, Unique, A/AAAA/CNAME if (UniqueLocalOnlyRecord(rr) && LocalOnlyRecordAnswersQuestion(rr, q)) { LogInfo("LocalRecordRmvEventsForQuestion: Delivering possible Rmv events with record %s", ARDisplayString(m, rr)); if (q->CurrentAnswers <= 0 || q->LOAddressAnswers <= 0) { LogMsg("LocalRecordRmvEventsForQuestion: ERROR!! CurrentAnswers or LOAddressAnswers is zero %p %##s" " (%s) CurrentAnswers %d, LOAddressAnswers %d", q, q->qname.c, DNSTypeName(q->qtype), q->CurrentAnswers, q->LOAddressAnswers); continue; } AnswerLocalQuestionWithLocalAuthRecord(m, rr, QC_rmv); // MUST NOT dereference q again if (m->CurrentQuestion != q) { m->CurrentQuestion = mDNSNULL; return mDNSfalse; } } } m->CurrentQuestion = mDNSNULL; return mDNStrue; } // Returns false if the question got deleted while delivering the RMV events // The caller should handle the case mDNSexport mDNSBool CacheRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q) { if (m->CurrentQuestion) LogMsg("CacheRecordRmvEventsForQuestion: ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); // If it is a new question, we have not delivered any ADD events yet. So, don't deliver RMV events. // If this question was answered using local auth records, then you can't deliver RMVs using cache if (!IsQuestionNew(m, q) && !q->LOAddressAnswers) { m->CurrentQuestion = q; CacheRecordRmvEventsForCurrentQuestion(m, q); if (m->CurrentQuestion != q) { m->CurrentQuestion = mDNSNULL; return mDNSfalse; } m->CurrentQuestion = mDNSNULL; } else { LogInfo("CacheRecordRmvEventsForQuestion: Question %p %##s (%s) is a new question", q, q->qname.c, DNSTypeName(q->qtype)); } return mDNStrue; } mDNSlocal void SuppressStatusChanged(mDNS *const m, DNSQuestion *q, DNSQuestion **restart) { // NOTE: CacheRecordRmvEventsForQuestion will not generate RMV events for queries that have non-zero // LOAddressAnswers. Hence it is important that we call CacheRecordRmvEventsForQuestion before // LocalRecordRmvEventsForQuestion (which decrements LOAddressAnswers) if (q->Suppressed) { q->Suppressed = mDNSfalse; if (!CacheRecordRmvEventsForQuestion(m, q)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] SuppressStatusChanged: Question deleted while delivering RMV events from cache", q->request_id, mDNSVal16(q->TargetQID)); return; } q->Suppressed = mDNStrue; } // SuppressUnusable does not affect questions that are answered from the local records (/etc/hosts) // and Suppressed status does not mean anything for these questions. As we are going to stop the // question below, we need to deliver the RMV events so that the ADDs that will be delivered during // the restart will not be a duplicate ADD if (!LocalRecordRmvEventsForQuestion(m, q)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] SuppressStatusChanged: Question deleted while delivering RMV events from Local AuthRecords", q->request_id, mDNSVal16(q->TargetQID)); return; } // There are two cases here. // // 1. Previously it was suppressed and now it is not suppressed, restart the question so // that it will start as a new question. Note that we can't just call ActivateUnicastQuery // because when we get the response, if we had entries in the cache already, it will not answer // this question if the cache entry did not change. Hence, we need to restart // the query so that it can be answered from the cache. // // 2. Previously it was not suppressed and now it is suppressed. We need to restart the questions // so that we redo the duplicate checks in mDNS_StartQuery_internal. A SuppressUnusable question // is a duplicate of non-SuppressUnusable question if it is not suppressed (Suppressed is false). // A SuppressUnusable question is not a duplicate of non-SuppressUnusable question if it is suppressed // (Suppressed is true). The reason for this is that when a question is suppressed, we want an // immediate response and not want to be blocked behind a question that is querying DNS servers. When // the question is not suppressed, we don't want two active questions sending packets on the wire. // This affects both efficiency and also the current design where there is only one active question // pointed to from a cache entry. // // We restart queries in a two step process by first calling stop and build a temporary list which we // will restart at the end. The main reason for the two step process is to handle duplicate questions. // If there are duplicate questions, calling stop inherits the values from another question on the list (which // will soon become the real question) including q->ThisQInterval which might be zero if it was // suppressed before. At the end when we have restarted all questions, none of them is active as each // inherits from one another and we need to reactivate one of the questions here which is a little hacky. // // It is much cleaner and less error prone to build a list of questions and restart at the end. LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] SuppressStatusChanged: Stop question %p " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); mDNS_StopQuery_internal(m, q); q->next = *restart; *restart = q; } // The caller should hold the lock mDNSexport void CheckSuppressUnusableQuestions(mDNS *const m) { DNSQuestion *q; DNSQuestion *restart = mDNSNULL; // We look through all questions including new questions. During network change events, // we potentially restart questions here in this function that ends up as new questions, // which may be suppressed at this instance. Before it is handled we get another network // event that changes the status e.g., address becomes available. If we did not process // new questions, we would never change its Suppressed status. // // CurrentQuestion is used by RmvEventsForQuestion below. While delivering RMV events, the // application callback can potentially stop the current question (detected by CurrentQuestion) or // *any* other question which could be the next one that we may process here. RestartQuestion // points to the "next" question which will be automatically advanced in mDNS_StopQuery_internal // if the "next" question is stopped while the CurrentQuestion is stopped if (m->RestartQuestion) LogMsg("CheckSuppressUnusableQuestions: ERROR!! m->RestartQuestion already set: %##s (%s)", m->RestartQuestion->qname.c, DNSTypeName(m->RestartQuestion->qtype)); m->RestartQuestion = m->Questions; while (m->RestartQuestion) { q = m->RestartQuestion; m->RestartQuestion = q->next; if (q->SuppressUnusable) { const mDNSBool old = q->Suppressed; q->Suppressed = ShouldSuppressQuery(q); if (q->Suppressed != old) { // Previously it was not suppressed, Generate RMV events for the ADDs that we might have delivered before // followed by a negative cache response. Temporarily turn off suppression so that // AnswerCurrentQuestionWithResourceRecord can answer the question SuppressStatusChanged(m, q, &restart); } } } while (restart) { q = restart; restart = restart->next; q->next = mDNSNULL; LogInfo("CheckSuppressUnusableQuestions: Start question %p %##s (%s)", q, q->qname.c, DNSTypeName(q->qtype)); mDNS_StartQuery_internal(m, q); } } #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSlocal void RestartUnicastQuestions(mDNS *const m) { DNSQuestion *q; DNSQuestion *restartList = mDNSNULL; if (m->RestartQuestion) LogMsg("RestartUnicastQuestions: ERROR!! m->RestartQuestion already set: %##s (%s)", m->RestartQuestion->qname.c, DNSTypeName(m->RestartQuestion->qtype)); m->RestartQuestion = m->Questions; while (m->RestartQuestion) { q = m->RestartQuestion; m->RestartQuestion = q->next; if (q->Restart) { if (mDNSOpaque16IsZero(q->TargetQID)) LogMsg("RestartUnicastQuestions: ERROR!! Restart set for multicast question %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); q->Restart = mDNSfalse; SuppressStatusChanged(m, q, &restartList); } } while ((q = restartList) != mDNSNULL) { restartList = q->next; q->next = mDNSNULL; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] RestartUnicastQuestions: Start question %p " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); mDNS_StartQuery_internal(m, q); } } #endif // ValidateParameters() is called by mDNS_StartQuery_internal() to check the client parameters of // DNS Question that are already set by the client before calling mDNS_StartQuery() mDNSlocal mStatus ValidateParameters(mDNS *const m, DNSQuestion *const question) { if (!ValidateDomainName(&question->qname)) { LogMsg("ValidateParameters: Attempt to start query with invalid qname %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); return(mStatus_Invalid); } // If this question is referencing a specific interface, verify it exists if (question->InterfaceID && !LocalOnlyOrP2PInterface(question->InterfaceID)) { NetworkInterfaceInfo *intf = FirstInterfaceForID(m, question->InterfaceID); if (!intf) LogInfo("ValidateParameters: Note: InterfaceID %d for question %##s (%s) not currently found in active interface list", IIDPrintable(question->InterfaceID), question->qname.c, DNSTypeName(question->qtype)); } return(mStatus_NoError); } // InitDNSConfig() is called by InitCommonState() to initialize the DNS configuration of the Question. // These are a subset of the internal uDNS fields. Must be done before ShouldSuppressQuery() & mDNS_PurgeBeforeResolve() mDNSlocal void InitDNSConfig(mDNS *const m, DNSQuestion *const question) { // First reset all DNS Configuration #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_forget(&question->dnsservice); #else question->qDNSServer = mDNSNULL; question->validDNSServers = zeroOpaque128; question->triedAllServersOnce = mDNSfalse; question->noServerResponse = mDNSfalse; #endif question->StopTime = (question->TimeoutQuestion) ? question->StopTime : 0; #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) mDNSPlatformMemZero(&question->metrics, sizeof(question->metrics)); question->metrics.expiredAnswerState = (question->allowExpired != AllowExpired_None) ? ExpiredAnswer_Allowed : ExpiredAnswer_None; #endif // Need not initialize the DNS Configuration for Local Only OR P2P Questions when timeout not specified if (LocalOnlyOrP2PInterface(question->InterfaceID) && !question->TimeoutQuestion) return; // Proceed to initialize DNS Configuration (some are set in SetValidDNSServers()) if (!mDNSOpaque16IsZero(question->TargetQID)) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSu32 timeout = 30; #else mDNSu32 timeout = SetValidDNSServers(m, question); #endif // We set the timeout value the first time mDNS_StartQuery_internal is called for a question. // So if a question is restarted when a network change occurs, the StopTime is not reset. // Note that we set the timeout for all questions. If this turns out to be a duplicate, // it gets a full timeout value even if the original question times out earlier. if (question->TimeoutQuestion && !question->StopTime) { question->StopTime = NonZeroTime(m->timenow + timeout * mDNSPlatformOneSecond); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[Q%u] InitDNSConfig: Setting StopTime on the uDNS question %p " PRI_DM_NAME " (" PUB_S ")", mDNSVal16(question->TargetQID), question, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype)); } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) Querier_SetDNSServiceForQuestion(question); #else question->qDNSServer = GetServerForQuestion(m, question); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%u->Q%u] InitDNSConfig: question %p " PRI_DM_NAME " " PUB_S " Timeout %d, DNS Server " PRI_IP_ADDR ":%d", question->request_id, mDNSVal16(question->TargetQID), question, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype), timeout, question->qDNSServer ? &question->qDNSServer->addr : mDNSNULL, mDNSVal16(question->qDNSServer ? question->qDNSServer->port : zeroIPPort)); #endif } else if (question->TimeoutQuestion && !question->StopTime) { // If the question is to be timed out and its a multicast, local-only or P2P case, // then set it's stop time. mDNSu32 timeout = LocalOnlyOrP2PInterface(question->InterfaceID) ? DEFAULT_LO_OR_P2P_TIMEOUT : GetTimeoutForMcastQuestion(m, question); question->StopTime = NonZeroTime(m->timenow + timeout * mDNSPlatformOneSecond); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] InitDNSConfig: Setting StopTime on the uDNS question %p " PRI_DM_NAME " (" PUB_S ")", question->request_id, mDNSVal16(question->TargetQID), question, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype)); } // Set StopTime here since it is a part of DNS Configuration if (question->StopTime) SetNextQueryStopTime(m, question); // Don't call SetNextQueryTime() if a LocalOnly OR P2P Question since those questions // will never be transmitted on the wire. if (!(LocalOnlyOrP2PInterface(question->InterfaceID))) SetNextQueryTime(m,question); } // InitCommonState() is called by mDNS_StartQuery_internal() to initialize the common(uDNS/mDNS) internal // state fields of the DNS Question. These are independent of the Client layer. mDNSlocal void InitCommonState(mDNS *const m, DNSQuestion *const question) { int i; // Note: In the case where we already have the answer to this question in our cache, that may be all the client // wanted, and they may immediately cancel their question. In this case, sending an actual query on the wire would // be a waste. For that reason, we schedule our first query to go out in half a second (InitialQuestionInterval). // If AnswerNewQuestion() finds that we have *no* relevant answers currently in our cache, then it will accelerate // that to go out immediately. question->next = mDNSNULL; // ThisQInterval should be initialized before any memory allocations occur. If malloc // debugging is turned on within mDNSResponder (see mDNSDebug.h for details) it validates // the question list to check if ThisQInterval is negative which means the question has been // stopped and can't be on the list. The question is already on the list and ThisQInterval // can be negative if the caller just stopped it and starting it again. Hence, it always has to // be initialized. CheckForSoonToExpireRecords below prints the cache records when logging is // turned ON which can allocate memory e.g., base64 encoding. question->ThisQInterval = InitialQuestionInterval; // MUST be > zero for an active question question->qnamehash = DomainNameHashValue(&question->qname); question->DelayAnswering = mDNSOpaque16IsZero(question->TargetQID) ? CheckForSoonToExpireRecords(m, &question->qname, question->qnamehash) : 0; question->LastQTime = m->timenow; question->ExpectUnicastResp = 0; question->LastAnswerPktNum = m->PktNum; question->RecentAnswerPkts = 0; question->CurrentAnswers = 0; #if APPLE_OSX_mDNSResponder // Initial browse threshold used by Finder. #define mDNSFinderBrowseThreshold 20 // Set the threshold at which we move to a passive browse state, // not actively sending queries. if (question->flags & kDNSServiceFlagsThresholdOne) question->BrowseThreshold = 1; else if (question->flags & kDNSServiceFlagsThresholdFinder) question->BrowseThreshold = mDNSFinderBrowseThreshold; else question->BrowseThreshold = 0; #else // APPLE_OSX_mDNSResponder question->BrowseThreshold = 0; #endif // APPLE_OSX_mDNSResponder question->CachedAnswerNeedsUpdate = mDNSfalse; question->LargeAnswers = 0; question->UniqueAnswers = 0; question->LOAddressAnswers = 0; question->FlappingInterface1 = mDNSNULL; question->FlappingInterface2 = mDNSNULL; // mDNSPlatformGetDNSRoutePolicy() and InitDNSConfig() may set a DNSQuestion's BlockedByPolicy value, // so they should be called before calling ShouldSuppressQuery(), which checks BlockedByPolicy. question->BlockedByPolicy = mDNSfalse; // if kDNSServiceFlagsServiceIndex flag is SET by the client, then do NOT call mDNSPlatformGetDNSRoutePolicy() // since we would already have the question->ServiceID in that case. if (!(question->flags & kDNSServiceFlagsServiceIndex)) { question->ServiceID = -1; #if APPLE_OSX_mDNSResponder if (!(question->flags & kDNSServiceFlagsPathEvaluationDone) || question->ForcePathEval) { if (question->flags & kDNSServiceFlagsPathEvaluationDone) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] Forcing another path evaluation", question->request_id, mDNSVal16(question->TargetQID)); } question->ForcePathEval = mDNSfalse; mDNSPlatformGetDNSRoutePolicy(question); } #endif } else LogInfo("InitCommonState: Query for %##s (%s), PID[%d], EUID[%d], ServiceID[%d] is already set by client", question->qname.c, DNSTypeName(question->qtype), question->pid, question->euid, question->ServiceID); InitDNSConfig(m, question); question->AuthInfo = GetAuthInfoForQuestion(m, question); question->Suppressed = ShouldSuppressQuery(question); question->NextInDQList = mDNSNULL; question->SendQNow = mDNSNULL; question->SendOnAll = mDNSfalse; question->RequestUnicast = kDefaultRequestUnicastCount; #if APPLE_OSX_mDNSResponder // Set the QU bit in the first query for the following options. if ((question->flags & kDNSServiceFlagsUnicastResponse) || (question->flags & kDNSServiceFlagsThresholdFinder)) { question->RequestUnicast = SET_QU_IN_FIRST_QUERY; LogInfo("InitCommonState: setting RequestUnicast = %d for %##s (%s)", question->RequestUnicast, question->qname.c, DNSTypeName(question->qtype)); } #endif // APPLE_OSX_mDNSResponder question->LastQTxTime = m->timenow; question->CNAMEReferrals = 0; question->WakeOnResolveCount = 0; if (question->WakeOnResolve) { question->WakeOnResolveCount = InitialWakeOnResolveCount; } for (i=0; iDupSuppress[i].InterfaceID = mDNSNULL; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) question->Restart = mDNSfalse; #endif debugf("InitCommonState: Question %##s (%s) Interface %p Now %d Send in %d Answer in %d (%p) %s (%p)", question->qname.c, DNSTypeName(question->qtype), question->InterfaceID, m->timenow, NextQSendTime(question) - m->timenow, question->DelayAnswering ? question->DelayAnswering - m->timenow : 0, question, question->DuplicateOf ? "duplicate of" : "not duplicate", question->DuplicateOf); if (question->DelayAnswering) LogInfo("InitCommonState: Delaying answering for %d ticks while cache stabilizes for %##s (%s)", question->DelayAnswering - m->timenow, question->qname.c, DNSTypeName(question->qtype)); } // Excludes the DNS Config fields which are already handled by InitDNSConfig() mDNSlocal void InitWABState(DNSQuestion *const question) { // We'll create our question->LocalSocket on demand, if needed. // We won't need one for duplicate questions, or from questions answered immediately out of the cache. // We also don't need one for LLQs because (when we're using NAT) we want them all to share a single // NAT mapping for receiving inbound add/remove events. question->LocalSocket = mDNSNULL; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_querier_forget(&question->querier); #else question->unansweredQueries = 0; #endif question->nta = mDNSNULL; question->servAddr = zeroAddr; question->servPort = zeroIPPort; question->tcp = mDNSNULL; question->NoAnswer = NoAnswer_Normal; } mDNSlocal void InitLLQNATState(mDNS *const m) { // If we don't have our NAT mapping active, start it now if (!m->LLQNAT.clientCallback) { m->LLQNAT.Protocol = NATOp_MapUDP; m->LLQNAT.IntPort = m->UnicastPort4; m->LLQNAT.RequestedPort = m->UnicastPort4; m->LLQNAT.clientCallback = LLQNATCallback; m->LLQNAT.clientContext = (void*)1; // Means LLQ NAT Traversal just started mDNS_StartNATOperation_internal(m, &m->LLQNAT); } } mDNSlocal void InitLLQState(DNSQuestion *const question) { question->state = LLQ_Init; question->ReqLease = 0; question->expire = 0; question->ntries = 0; question->id = zeroOpaque64; } // InitDNSSECProxyState() is called by mDNS_StartQuery_internal() to initialize // DNSSEC & DNS Proxy fields of the DNS Question. mDNSlocal void InitDNSSECProxyState(mDNS *const m, DNSQuestion *const question) { (void) m; question->responseFlags = zeroID; } // Once the question is completely initialized including the duplicate logic, this function // is called to finalize the unicast question which requires flushing the cache if needed, // activating the query etc. mDNSlocal void FinalizeUnicastQuestion(mDNS *const m, DNSQuestion *question) { // Ensure DNS related info of duplicate question is same as the orig question if (question->DuplicateOf) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) const DNSQuestion *const duplicateOf = question->DuplicateOf; mdns_replace(&question->dnsservice, duplicateOf->dnsservice); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->DupQ%u->Q%u] Duplicate question " PRI_DM_NAME " (" PUB_S ")", question->request_id, mDNSVal16(question->TargetQID), mDNSVal16(duplicateOf->TargetQID), DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype)); #else question->validDNSServers = question->DuplicateOf->validDNSServers; // If current(dup) question has DNS Server assigned but the original question has no DNS Server assigned to it, // then we log a line as it could indicate an issue if (question->DuplicateOf->qDNSServer == mDNSNULL) { if (question->qDNSServer) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] FinalizeUnicastQuestion: Current(dup) question %p has DNSServer(" PRI_IP_ADDR ":%d) but original question(%p) has no DNS Server! " PRI_DM_NAME " (" PUB_S ")", question->request_id, mDNSVal16(question->TargetQID), question, question->qDNSServer ? &question->qDNSServer->addr : mDNSNULL, mDNSVal16(question->qDNSServer ? question->qDNSServer->port : zeroIPPort), question->DuplicateOf, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype)); } } question->qDNSServer = question->DuplicateOf->qDNSServer; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->DupQ%d->Q%d] FinalizeUnicastQuestion: Duplicate question %p (%p) " PRI_DM_NAME " (" PUB_S "), DNS Server " PRI_IP_ADDR ":%d", question->request_id, mDNSVal16(question->TargetQID), mDNSVal16(question->DuplicateOf->TargetQID), question, question->DuplicateOf, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype), question->qDNSServer ? &question->qDNSServer->addr : mDNSNULL, mDNSVal16(question->qDNSServer ? question->qDNSServer->port : zeroIPPort)); #endif } ActivateUnicastQuery(m, question, mDNSfalse); if (question->LongLived) { // Unlike other initializations, InitLLQNATState should be done after // we determine that it is a unicast question. LongLived is set for // both multicast and unicast browse questions but we should initialize // the LLQ NAT state only for unicast. Otherwise we will unnecessarily // start the NAT traversal that is not needed. InitLLQNATState(m); } } mDNSexport mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question) { DNSQuestion **q; mStatus vStatus; // First check for cache space (can't do queries if there is no cache space allocated) if (m->rrcache_size == 0) return(mStatus_NoCache); vStatus = ValidateParameters(m, question); if (vStatus) return(vStatus); #ifdef USE_LIBIDN // If the TLD includes high-ascii bytes, assume it will need to be converted to Punycode. // (In the future the root name servers may answer UTF-8 queries directly, but for now they do not.) // This applies to the top label (TLD) only // -- for the second level and down we try UTF-8 first, and then fall back to Punycode only if UTF-8 fails. if (IsHighASCIILabel(LastLabel(&question->qname))) { domainname newname; if (PerformNextPunycodeConversion(question, &newname)) AssignDomainName(&question->qname, &newname); } #endif // USE_LIBIDN #ifndef UNICAST_DISABLED question->TargetQID = Question_uDNS(question) ? mDNS_NewMessageID(m) : zeroID; #else question->TargetQID = zeroID; #endif debugf("mDNS_StartQuery_internal: %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); // Note: It important that new questions are appended at the *end* of the list, not prepended at the start q = &m->Questions; if (LocalOnlyOrP2PInterface(question->InterfaceID)) q = &m->LocalOnlyQuestions; while (*q && *q != question) q=&(*q)->next; if (*q) { LogMsg("mDNS_StartQuery_internal: Error! Tried to add a question %##s (%s) %p that's already in the active list", question->qname.c, DNSTypeName(question->qtype), question); return(mStatus_AlreadyRegistered); } *q = question; // Intialize the question. The only ordering constraint we have today is that // InitDNSSECProxyState should be called after the DNS server is selected (in // InitCommonState -> InitDNSConfig) as DNS server selection affects DNSSEC // validation. InitCommonState(m, question); InitWABState(question); InitLLQState(question); InitDNSSECProxyState(m, question); // FindDuplicateQuestion should be called last after all the intialization // as the duplicate logic could be potentially based on any field in the // question. question->DuplicateOf = FindDuplicateQuestion(m, question); if (question->DuplicateOf) question->AuthInfo = question->DuplicateOf->AuthInfo; if (LocalOnlyOrP2PInterface(question->InterfaceID)) { if (!m->NewLocalOnlyQuestions) m->NewLocalOnlyQuestions = question; } else { if (!m->NewQuestions) m->NewQuestions = question; // If the question's id is non-zero, then it's Wide Area // MUST NOT do this Wide Area setup until near the end of // mDNS_StartQuery_internal -- this code may itself issue queries (e.g. SOA, // NS, etc.) and if we haven't finished setting up our own question and setting // m->NewQuestions if necessary then we could end up recursively re-entering // this routine with the question list data structures in an inconsistent state. if (!mDNSOpaque16IsZero(question->TargetQID)) { FinalizeUnicastQuestion(m, question); } else { #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) m->NumAllInterfaceQuestions++; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNS_StartQuery_internal: NumAllInterfaceRecords %u NumAllInterfaceQuestions %u " PRI_DM_NAME " (" PUB_S ")", m->NumAllInterfaceRecords, m->NumAllInterfaceQuestions, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype)); if (m->NumAllInterfaceRecords + m->NumAllInterfaceQuestions == 1) { m->NextBonjourDisableTime = 0; if (m->BonjourEnabled == 0) { // Enable Bonjour immediately by scheduling network changed processing where // we will join the multicast group on each active interface. m->BonjourEnabled = 1; m->NetworkChanged = m->timenow; } } #endif if (question->WakeOnResolve) { LogInfo("mDNS_StartQuery_internal: Purging for %##s", question->qname.c); mDNS_PurgeBeforeResolve(m, question); } } } return(mStatus_NoError); } // CancelGetZoneData is an internal routine (i.e. must be called with the lock already held) mDNSexport void CancelGetZoneData(mDNS *const m, ZoneData *nta) { debugf("CancelGetZoneData %##s (%s)", nta->question.qname.c, DNSTypeName(nta->question.qtype)); // This function may be called anytime to free the zone information.The question may or may not have stopped. // If it was already stopped, mDNS_StopQuery_internal would have set q->ThisQInterval to -1 and should not // call it again if (nta->question.ThisQInterval != -1) { mDNS_StopQuery_internal(m, &nta->question); if (nta->question.ThisQInterval != -1) LogMsg("CancelGetZoneData: Question %##s (%s) ThisQInterval %d not -1", nta->question.qname.c, DNSTypeName(nta->question.qtype), nta->question.ThisQInterval); } mDNSPlatformMemFree(nta); } mDNSexport mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question) { CacheGroup *cg = CacheGroupForName(m, question->qnamehash, &question->qname); CacheRecord *cr; DNSQuestion **qp = &m->Questions; //LogInfo("mDNS_StopQuery_internal %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); if (LocalOnlyOrP2PInterface(question->InterfaceID)) qp = &m->LocalOnlyQuestions; while (*qp && *qp != question) qp=&(*qp)->next; if (*qp) *qp = (*qp)->next; else { #if !ForceAlerts if (question->ThisQInterval >= 0) // Only log error message if the query was supposed to be active #endif LogFatalError("mDNS_StopQuery_internal: Question %##s (%s) not found in active list", question->qname.c, DNSTypeName(question->qtype)); return(mStatus_BadReferenceErr); } #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) if (!LocalOnlyOrP2PInterface(question->InterfaceID) && mDNSOpaque16IsZero(question->TargetQID)) { if (m->NumAllInterfaceRecords + m->NumAllInterfaceQuestions == 1) m->NextBonjourDisableTime = NonZeroTime(m->timenow + (BONJOUR_DISABLE_DELAY * mDNSPlatformOneSecond)); m->NumAllInterfaceQuestions--; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNS_StopQuery_internal: NumAllInterfaceRecords %u NumAllInterfaceQuestions %u " PRI_DM_NAME " (" PUB_S ")", m->NumAllInterfaceRecords, m->NumAllInterfaceQuestions, DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype)); } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if (Question_uDNS(question) && !question->metrics.answered && (question->metrics.firstQueryTime != 0)) { mDNSu32 querySendCount = question->metrics.querySendCount; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (question->querier) { querySendCount += mdns_querier_get_send_count(question->querier); } #endif if (querySendCount > 0) { const domainname * queryName; mDNSBool isForCell; mDNSu32 durationMs; queryName = question->metrics.originalQName ? question->metrics.originalQName : &question->qname; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) isForCell = (question->dnsservice && mdns_dns_service_interface_is_cellular(question->dnsservice)); #else isForCell = (question->qDNSServer && question->qDNSServer->isCell); #endif durationMs = ((m->timenow - question->metrics.firstQueryTime) * 1000) / mDNSPlatformOneSecond; MetricsUpdateDNSQueryStats(queryName, question->qtype, mDNSNULL, querySendCount, question->metrics.expiredAnswerState, question->metrics.dnsOverTCPState, durationMs, isForCell); } } #endif // Take care to cut question from list *before* calling UpdateQuestionDuplicates UpdateQuestionDuplicates(m, question); // But don't trash ThisQInterval until afterwards. question->ThisQInterval = -1; // If there are any cache records referencing this as their active question, then see if there is any // other question that is also referencing them, else their CRActiveQuestion needs to get set to NULL. for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { if (cr->CRActiveQuestion == question) { DNSQuestion *q; DNSQuestion *replacement = mDNSNULL; // If we find an active question that is answered by this cached record, use it as the cache record's // CRActiveQuestion replacement. If there are no such questions, but there's at least one unsuppressed inactive // question that is answered by this cache record, then use an inactive one to not forgo generating RMV events // via CacheRecordRmv() when the cache record expires. for (q = m->Questions; q && (q != m->NewQuestions); q = q->next) { if (!q->DuplicateOf && !q->Suppressed && CacheRecordAnswersQuestion(cr, q)) { if (q->ThisQInterval > 0) { replacement = q; break; } else if (!replacement) { replacement = q; } } } if (replacement) debugf("mDNS_StopQuery_internal: Updating CRActiveQuestion to %p for cache record %s, Original question CurrentAnswers %d, new question " "CurrentAnswers %d, Suppressed %d", replacement, CRDisplayString(m,cr), question->CurrentAnswers, replacement->CurrentAnswers, replacement->Suppressed); cr->CRActiveQuestion = replacement; // Question used to be active; new value may or may not be null if (!replacement) m->rrcache_active--; // If no longer active, decrement rrcache_active count } } // If we just deleted the question that CacheRecordAdd() or CacheRecordRmv() is about to look at, // bump its pointer forward one question. if (m->CurrentQuestion == question) { debugf("mDNS_StopQuery_internal: Just deleted the currently active question: %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); m->CurrentQuestion = question->next; } if (m->NewQuestions == question) { debugf("mDNS_StopQuery_internal: Just deleted a new question that wasn't even answered yet: %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); m->NewQuestions = question->next; } if (m->NewLocalOnlyQuestions == question) m->NewLocalOnlyQuestions = question->next; if (m->RestartQuestion == question) { LogMsg("mDNS_StopQuery_internal: Just deleted the current restart question: %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); m->RestartQuestion = question->next; } // Take care not to trash question->next until *after* we've updated m->CurrentQuestion and m->NewQuestions question->next = mDNSNULL; // LogMsg("mDNS_StopQuery_internal: Question %##s (%s) removed", question->qname.c, DNSTypeName(question->qtype)); // And finally, cancel any associated GetZoneData operation that's still running. // Must not do this until last, because there's a good chance the GetZoneData question is the next in the list, // so if we delete it earlier in this routine, we could find that our "question->next" pointer above is already // invalid before we even use it. By making sure that we update m->CurrentQuestion and m->NewQuestions if necessary // *first*, then they're all ready to be updated a second time if necessary when we cancel our GetZoneData query. if (question->tcp) { DisposeTCPConn(question->tcp); question->tcp = mDNSNULL; } if (question->LocalSocket) { mDNSPlatformUDPClose(question->LocalSocket); question->LocalSocket = mDNSNULL; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) Querier_HandleStoppedDNSQuestion(question); #endif if (!mDNSOpaque16IsZero(question->TargetQID) && question->LongLived) { // Scan our list to see if any more wide-area LLQs remain. If not, stop our NAT Traversal. DNSQuestion *q; for (q = m->Questions; q; q=q->next) if (!mDNSOpaque16IsZero(q->TargetQID) && q->LongLived) break; if (!q) { if (!m->LLQNAT.clientCallback) // Should never happen, but just in case... { LogMsg("mDNS_StopQuery ERROR LLQNAT.clientCallback NULL"); } else { LogInfo("Stopping LLQNAT"); mDNS_StopNATOperation_internal(m, &m->LLQNAT); m->LLQNAT.clientCallback = mDNSNULL; // Means LLQ NAT Traversal not running } } // If necessary, tell server it can delete this LLQ state if (question->state == LLQ_Established) { question->ReqLease = 0; sendLLQRefresh(m, question); // If we need need to make a TCP connection to cancel the LLQ, that's going to take a little while. // We clear the tcp->question backpointer so that when the TCP connection completes, it doesn't // crash trying to access our cancelled question, but we don't cancel the TCP operation itself -- // we let that run out its natural course and complete asynchronously. if (question->tcp) { question->tcp->question = mDNSNULL; question->tcp = mDNSNULL; } } #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) else if (question->dnsPushServer != mDNSNULL) { UnSubscribeToDNSPushNotificationServer(m, question); } #endif } // wait until we send the refresh above which needs the nta if (question->nta) { CancelGetZoneData(m, question->nta); question->nta = mDNSNULL; } #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) uDNSMetricsClear(&question->metrics); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) DNS64ResetState(question); #endif return(mStatus_NoError); } mDNSexport mStatus mDNS_StartQuery(mDNS *const m, DNSQuestion *const question) { mStatus status; mDNS_Lock(m); status = mDNS_StartQuery_internal(m, question); mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_StopQuery(mDNS *const m, DNSQuestion *const question) { mStatus status; mDNS_Lock(m); status = mDNS_StopQuery_internal(m, question); mDNS_Unlock(m); return(status); } // Note that mDNS_StopQueryWithRemoves() does not currently implement the full generality of the other APIs // Specifically, question callbacks invoked as a result of this call cannot themselves make API calls. // We invoke the callback without using mDNS_DropLockBeforeCallback/mDNS_ReclaimLockAfterCallback // specifically to catch and report if the client callback does try to make API calls mDNSexport mStatus mDNS_StopQueryWithRemoves(mDNS *const m, DNSQuestion *const question) { mStatus status; DNSQuestion *qq; mDNS_Lock(m); // Check if question is new -- don't want to give remove events for a question we haven't even answered yet for (qq = m->NewQuestions; qq; qq=qq->next) if (qq == question) break; status = mDNS_StopQuery_internal(m, question); if (status == mStatus_NoError && !qq) { const CacheRecord *cr; CacheGroup *const cg = CacheGroupForName(m, question->qnamehash, &question->qname); LogInfo("Generating terminal removes for %##s (%s)", question->qname.c, DNSTypeName(question->qtype)); for (cr = cg ? cg->members : mDNSNULL; cr; cr=cr->next) { if (cr->resrec.RecordType != kDNSRecordTypePacketNegative && SameNameCacheRecordAnswersQuestion(cr, question)) { // Don't use mDNS_DropLockBeforeCallback() here, since we don't allow API calls if (question->QuestionCallback) question->QuestionCallback(m, question, &cr->resrec, QC_rmv); } } } mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_Reconfirm(mDNS *const m, CacheRecord *const cr) { mStatus status; mDNS_Lock(m); status = mDNS_Reconfirm_internal(m, cr, kDefaultReconfirmTimeForNoAnswer); if (status == mStatus_NoError) ReconfirmAntecedents(m, cr->resrec.name, cr->resrec.namehash, cr->resrec.InterfaceID, 0); mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_ReconfirmByValue(mDNS *const m, ResourceRecord *const rr) { mStatus status = mStatus_BadReferenceErr; CacheRecord *cr; mDNS_Lock(m); cr = FindIdenticalRecordInCache(m, rr); debugf("mDNS_ReconfirmByValue: %p %s", cr, RRDisplayString(m, rr)); if (cr) status = mDNS_Reconfirm_internal(m, cr, kDefaultReconfirmTimeForNoAnswer); if (status == mStatus_NoError) ReconfirmAntecedents(m, cr->resrec.name, cr->resrec.namehash, cr->resrec.InterfaceID, 0); mDNS_Unlock(m); return(status); } mDNSlocal mStatus mDNS_StartBrowse_internal(mDNS *const m, DNSQuestion *const question, const domainname *const srv, const domainname *const domain, const mDNSInterfaceID InterfaceID, mDNSu32 flags, mDNSBool ForceMCast, mDNSBool useBackgroundTrafficClass, mDNSQuestionCallback *Callback, void *Context) { question->InterfaceID = InterfaceID; question->flags = flags; question->qtype = kDNSType_PTR; question->qclass = kDNSClass_IN; question->LongLived = mDNStrue; question->ExpectUnique = mDNSfalse; question->ForceMCast = ForceMCast; question->ReturnIntermed = (flags & kDNSServiceFlagsReturnIntermediates) != 0; question->SuppressUnusable = mDNSfalse; question->AppendSearchDomains = mDNSfalse; question->TimeoutQuestion = 0; question->WakeOnResolve = 0; question->UseBackgroundTraffic = useBackgroundTrafficClass; question->ProxyQuestion = 0; question->QuestionCallback = Callback; question->QuestionContext = Context; if (!ConstructServiceName(&question->qname, mDNSNULL, srv, domain)) return(mStatus_BadParamErr); return(mDNS_StartQuery_internal(m, question)); } mDNSexport mStatus mDNS_StartBrowse(mDNS *const m, DNSQuestion *const question, const domainname *const srv, const domainname *const domain, const mDNSInterfaceID InterfaceID, mDNSu32 flags, mDNSBool ForceMCast, mDNSBool useBackgroundTrafficClass, mDNSQuestionCallback *Callback, void *Context) { mStatus status; mDNS_Lock(m); status = mDNS_StartBrowse_internal(m, question, srv, domain, InterfaceID, flags, ForceMCast, useBackgroundTrafficClass, Callback, Context); mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_GetDomains(mDNS *const m, DNSQuestion *const question, mDNS_DomainType DomainType, const domainname *dom, const mDNSInterfaceID InterfaceID, mDNSQuestionCallback *Callback, void *Context) { question->InterfaceID = InterfaceID; question->flags = 0; question->qtype = kDNSType_PTR; question->qclass = kDNSClass_IN; question->LongLived = mDNSfalse; question->ExpectUnique = mDNSfalse; question->ForceMCast = mDNSfalse; question->ReturnIntermed = mDNSfalse; question->SuppressUnusable = mDNSfalse; question->AppendSearchDomains = mDNSfalse; question->TimeoutQuestion = 0; question->WakeOnResolve = 0; question->UseBackgroundTraffic = mDNSfalse; question->ProxyQuestion = 0; question->pid = mDNSPlatformGetPID(); question->euid = 0; question->QuestionCallback = Callback; question->QuestionContext = Context; if (DomainType > mDNS_DomainTypeMax) return(mStatus_BadParamErr); if (!MakeDomainNameFromDNSNameString(&question->qname, mDNS_DomainTypeNames[DomainType])) return(mStatus_BadParamErr); if (!dom) dom = &localdomain; if (!AppendDomainName(&question->qname, dom)) return(mStatus_BadParamErr); return(mDNS_StartQuery(m, question)); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Responder Functions #endif mDNSexport mStatus mDNS_Register(mDNS *const m, AuthRecord *const rr) { mStatus status; mDNS_Lock(m); status = mDNS_Register_internal(m, rr); mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_Update(mDNS *const m, AuthRecord *const rr, mDNSu32 newttl, const mDNSu16 newrdlength, RData *const newrdata, mDNSRecordUpdateCallback *Callback) { if (!ValidateRData(rr->resrec.rrtype, newrdlength, newrdata)) { LogMsg("Attempt to update record with invalid rdata: %s", GetRRDisplayString_rdb(&rr->resrec, &newrdata->u, m->MsgBuffer)); return(mStatus_Invalid); } mDNS_Lock(m); // If TTL is unspecified, leave TTL unchanged if (newttl == 0) newttl = rr->resrec.rroriginalttl; // If we already have an update queued up which has not gone through yet, give the client a chance to free that memory if (rr->NewRData) { RData *n = rr->NewRData; rr->NewRData = mDNSNULL; // Clear the NewRData pointer ... if (rr->UpdateCallback) rr->UpdateCallback(m, rr, n, rr->newrdlength); // ...and let the client free this memory, if necessary } rr->NewRData = newrdata; rr->newrdlength = newrdlength; rr->UpdateCallback = Callback; #ifndef UNICAST_DISABLED if (rr->ARType != AuthRecordLocalOnly && rr->ARType != AuthRecordP2P && !IsLocalDomain(rr->resrec.name)) { mStatus status = uDNS_UpdateRecord(m, rr); // The caller frees the memory on error, don't retain stale pointers if (status != mStatus_NoError) { rr->NewRData = mDNSNULL; rr->newrdlength = 0; } mDNS_Unlock(m); return(status); } #endif if (RRLocalOnly(rr) || (rr->resrec.rroriginalttl == newttl && rr->resrec.rdlength == newrdlength && mDNSPlatformMemSame(rr->resrec.rdata->u.data, newrdata->u.data, newrdlength))) CompleteRDataUpdate(m, rr); else { rr->AnnounceCount = InitialAnnounceCount; InitializeLastAPTime(m, rr); while (rr->NextUpdateCredit && m->timenow - rr->NextUpdateCredit >= 0) GrantUpdateCredit(rr); if (!rr->UpdateBlocked && rr->UpdateCredits) rr->UpdateCredits--; if (!rr->NextUpdateCredit) rr->NextUpdateCredit = NonZeroTime(m->timenow + kUpdateCreditRefreshInterval); if (rr->AnnounceCount > rr->UpdateCredits + 1) rr->AnnounceCount = (mDNSu8)(rr->UpdateCredits + 1); if (rr->UpdateCredits <= 5) { mDNSu32 delay = 6 - rr->UpdateCredits; // Delay 1 second, then 2, then 3, etc. up to 6 seconds maximum if (!rr->UpdateBlocked) rr->UpdateBlocked = NonZeroTime(m->timenow + (mDNSs32)delay * mDNSPlatformOneSecond); rr->ThisAPInterval *= 4; rr->LastAPTime = rr->UpdateBlocked - rr->ThisAPInterval; LogMsg("Excessive update rate for %##s; delaying announcement by %ld second%s", rr->resrec.name->c, delay, delay > 1 ? "s" : ""); } rr->resrec.rroriginalttl = newttl; } mDNS_Unlock(m); return(mStatus_NoError); } // Note: mDNS_Deregister calls mDNS_Deregister_internal which can call a user callback, which may change // the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSexport mStatus mDNS_Deregister(mDNS *const m, AuthRecord *const rr) { mStatus status; mDNS_Lock(m); status = mDNS_Deregister_internal(m, rr, mDNS_Dereg_normal); mDNS_Unlock(m); return(status); } // Circular reference: AdvertiseInterface references mDNS_HostNameCallback, which calls mDNS_SetFQDN, which call AdvertiseInterface mDNSlocal void mDNS_HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result); #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) mDNSlocal void mDNS_RandomizedHostNameCallback(mDNS *m, AuthRecord *rr, mStatus result); #endif mDNSlocal AuthRecord *GetInterfaceAddressRecord(NetworkInterfaceInfo *intf, mDNSBool forRandHostname) { #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) return(forRandHostname ? &intf->RR_AddrRand : &intf->RR_A); #else (void)forRandHostname; // Unused. return(&intf->RR_A); #endif } mDNSlocal AuthRecord *GetFirstAddressRecordEx(const mDNS *const m, const mDNSBool forRandHostname) { NetworkInterfaceInfo *intf; for (intf = m->HostInterfaces; intf; intf = intf->next) { if (!intf->Advertise) continue; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (mDNSPlatformInterfaceIsAWDL(intf->InterfaceID)) continue; #endif return(GetInterfaceAddressRecord(intf, forRandHostname)); } return(mDNSNULL); } #define GetFirstAddressRecord(M) GetFirstAddressRecordEx(M, mDNSfalse) // The parameter "set" here refers to the set of AuthRecords used to advertise this interface. // (It's a set of records, not a set of interfaces.) #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) mDNSlocal void AdvertiseInterface(mDNS *const m, NetworkInterfaceInfo *set, mDNSBool useRandomizedHostname) #else mDNSlocal void AdvertiseInterface(mDNS *const m, NetworkInterfaceInfo *set) #endif { const domainname *hostname; mDNSRecordCallback *hostnameCallback; AuthRecord *addrAR; AuthRecord *ptrAR; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) const mDNSBool interfaceIsAWDL = mDNSPlatformInterfaceIsAWDL(set->InterfaceID); #endif mDNSu8 addrRecordType; char buffer[MAX_REVERSE_MAPPING_NAME]; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (interfaceIsAWDL || useRandomizedHostname) { hostname = &m->RandomizedHostname; hostnameCallback = mDNS_RandomizedHostNameCallback; } else #endif { hostname = &m->MulticastHostname; hostnameCallback = mDNS_HostNameCallback; } #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (!interfaceIsAWDL && useRandomizedHostname) { addrAR = &set->RR_AddrRand; ptrAR = mDNSNULL; } else #endif { addrAR = &set->RR_A; ptrAR = &set->RR_PTR; } if (addrAR->resrec.RecordType != kDNSRecordTypeUnregistered) return; addrRecordType = set->DirectLink ? kDNSRecordTypeKnownUnique : kDNSRecordTypeUnique; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (hostname == &m->RandomizedHostname) addrRecordType = kDNSRecordTypeKnownUnique; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "AdvertiseInterface: Advertising " PUB_S " hostname on interface " PUB_S, (hostname == &m->RandomizedHostname) ? "randomized" : "normal", set->ifname); #else LogInfo("AdvertiseInterface: Advertising for ifname %s", set->ifname); #endif // Send dynamic update for non-linklocal IPv4 Addresses mDNS_SetupResourceRecord(addrAR, mDNSNULL, set->InterfaceID, kDNSType_A, kHostNameTTL, addrRecordType, AuthRecordAny, hostnameCallback, set); if (ptrAR) mDNS_SetupResourceRecord(ptrAR, mDNSNULL, set->InterfaceID, kDNSType_PTR, kHostNameTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); #if ANSWER_REMOTE_HOSTNAME_QUERIES addrAR->AllowRemoteQuery = mDNStrue; if (ptrAR) ptrAR->AllowRemoteQuery = mDNStrue; #endif // 1. Set up Address record to map from host name ("foo.local.") to IP address // 2. Set up reverse-lookup PTR record to map from our address back to our host name AssignDomainName(&addrAR->namestorage, hostname); if (set->ip.type == mDNSAddrType_IPv4) { addrAR->resrec.rrtype = kDNSType_A; addrAR->resrec.rdata->u.ipv4 = set->ip.ip.v4; // Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code mDNS_snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d.in-addr.arpa.", set->ip.ip.v4.b[3], set->ip.ip.v4.b[2], set->ip.ip.v4.b[1], set->ip.ip.v4.b[0]); } else if (set->ip.type == mDNSAddrType_IPv6) { int i; addrAR->resrec.rrtype = kDNSType_AAAA; addrAR->resrec.rdata->u.ipv6 = set->ip.ip.v6; for (i = 0; i < 16; i++) { static const char hexValues[] = "0123456789ABCDEF"; buffer[i * 4 ] = hexValues[set->ip.ip.v6.b[15 - i] & 0x0F]; buffer[i * 4 + 1] = '.'; buffer[i * 4 + 2] = hexValues[set->ip.ip.v6.b[15 - i] >> 4]; buffer[i * 4 + 3] = '.'; } mDNS_snprintf(&buffer[64], sizeof(buffer)-64, "ip6.arpa."); } if (ptrAR) { MakeDomainNameFromDNSNameString(&ptrAR->namestorage, buffer); ptrAR->AutoTarget = Target_AutoHost; // Tell mDNS that the target of this PTR is to be kept in sync with our host name ptrAR->ForceMCast = mDNStrue; // This PTR points to our dot-local name, so don't ever try to write it into a uDNS server } #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) addrAR->RRSet = interfaceIsAWDL ? addrAR : GetFirstAddressRecordEx(m, useRandomizedHostname); #else addrAR->RRSet = GetFirstAddressRecord(m); #endif if (!addrAR->RRSet) addrAR->RRSet = addrAR; mDNS_Register_internal(m, addrAR); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "Initialized RRSet for " PRI_S, ARDisplayString(m, addrAR)); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "RRSet: " PRI_S, ARDisplayString(m, addrAR->RRSet)); if (ptrAR) mDNS_Register_internal(m, ptrAR); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) // must be after the mDNS_Register_internal() calls so that records have complete rdata fields, etc D2D_start_advertising_interface(set); #endif } mDNSlocal void AdvertiseInterfaceIfNeeded(mDNS *const m, NetworkInterfaceInfo *set) { #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (mDNSPlatformInterfaceIsAWDL(set->InterfaceID)) { if ((m->AutoTargetAWDLIncludedCount > 0) || (m->AutoTargetAWDLOnlyCount > 0)) { AdvertiseInterface(m, set, mDNSfalse); } } else { if (m->AutoTargetServices > 0) AdvertiseInterface(m, set, mDNSfalse); if (m->AutoTargetAWDLIncludedCount > 0) AdvertiseInterface(m, set, mDNStrue); } #else if (m->AutoTargetServices > 0) AdvertiseInterface(m, set); #endif } mDNSlocal void DeadvertiseInterface(mDNS *const m, NetworkInterfaceInfo *set, DeadvertiseFlags flags) { #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) const mDNSBool interfaceIsAWDL = mDNSPlatformInterfaceIsAWDL(set->InterfaceID); #endif // Unregister these records. // When doing the mDNS_Exit processing, we first call DeadvertiseInterface for each interface, so by the time the platform // support layer gets to call mDNS_DeregisterInterface, the address and PTR records have already been deregistered for it. // Also, in the event of a name conflict, one or more of our records will have been forcibly deregistered. // To avoid unnecessary and misleading warning messages, we check the RecordType before calling mDNS_Deregister_internal(). #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if ((!interfaceIsAWDL && (flags & kDeadvertiseFlag_NormalHostname)) || ( interfaceIsAWDL && (flags & kDeadvertiseFlag_RandHostname))) #else if (flags & kDeadvertiseFlag_NormalHostname) #endif { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "DeadvertiseInterface: Deadvertising " PUB_S " hostname on interface " PUB_S, (flags & kDeadvertiseFlag_RandHostname) ? "randomized" : "normal", set->ifname); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) D2D_stop_advertising_interface(set); #endif if (set->RR_A.resrec.RecordType) mDNS_Deregister_internal(m, &set->RR_A, mDNS_Dereg_normal); if (set->RR_PTR.resrec.RecordType) mDNS_Deregister_internal(m, &set->RR_PTR, mDNS_Dereg_normal); } #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (!interfaceIsAWDL && (flags & kDeadvertiseFlag_RandHostname)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "DeadvertiseInterface: Deadvertising randomized hostname on interface " PUB_S, set->ifname); AuthRecord *const ar = &set->RR_AddrRand; if (ar->resrec.RecordType) mDNS_Deregister_internal(m, ar, mDNS_Dereg_normal); } #endif } // Change target host name for record. mDNSlocal void UpdateTargetHostName(mDNS *const m, AuthRecord *const rr) { #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) // If this record was also registered with any D2D plugins, stop advertising // the version with the old host name. D2D_stop_advertising_record(rr); #endif SetTargetToHostName(m, rr); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) // Advertise the record with the updated host name with the D2D plugins if appropriate. D2D_start_advertising_record(rr); #endif } mDNSlocal void DeadvertiseAllInterfaceRecords(mDNS *const m, DeadvertiseFlags flags) { NetworkInterfaceInfo *intf; for (intf = m->HostInterfaces; intf; intf = intf->next) { if (intf->Advertise) DeadvertiseInterface(m, intf, flags); } } mDNSexport void mDNS_SetFQDN(mDNS *const m) { domainname newmname; AuthRecord *rr; newmname.c[0] = 0; if (!AppendDomainLabel(&newmname, &m->hostlabel)) { LogMsg("ERROR: mDNS_SetFQDN: Cannot create MulticastHostname"); return; } if (!AppendLiteralLabelString(&newmname, "local")) { LogMsg("ERROR: mDNS_SetFQDN: Cannot create MulticastHostname"); return; } mDNS_Lock(m); if (SameDomainNameCS(&m->MulticastHostname, &newmname)) debugf("mDNS_SetFQDN - hostname unchanged"); else { AssignDomainName(&m->MulticastHostname, &newmname); DeadvertiseAllInterfaceRecords(m, kDeadvertiseFlag_NormalHostname); AdvertiseNecessaryInterfaceRecords(m); } // 3. Make sure that any AutoTarget SRV records (and the like) get updated for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->AutoTarget) UpdateTargetHostName(m, rr); for (rr = m->DuplicateRecords; rr; rr=rr->next) if (rr->AutoTarget) UpdateTargetHostName(m, rr); mDNS_Unlock(m); } mDNSlocal void mDNS_HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { (void)rr; // Unused parameter #if MDNS_DEBUGMSGS { char *msg = "Unknown result"; if (result == mStatus_NoError) msg = "Name registered"; else if (result == mStatus_NameConflict) msg = "Name conflict"; debugf("mDNS_HostNameCallback: %##s (%s) %s (%ld)", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), msg, result); } #endif if (result == mStatus_NoError) { // Notify the client that the host name is successfully registered if (m->MainCallback) m->MainCallback(m, mStatus_NoError); } else if (result == mStatus_NameConflict) { domainlabel oldlabel = m->hostlabel; // 1. First give the client callback a chance to pick a new name if (m->MainCallback) m->MainCallback(m, mStatus_NameConflict); // 2. If the client callback didn't do it, add (or increment) an index ourselves // This needs to be case-INSENSITIVE compare, because we need to know that the name has been changed so as to // remedy the conflict, and a name that differs only in capitalization will just suffer the exact same conflict again. if (SameDomainLabel(m->hostlabel.c, oldlabel.c)) IncrementLabelSuffix(&m->hostlabel, mDNSfalse); // 3. Generate the FQDNs from the hostlabel, // and make sure all SRV records, etc., are updated to reference our new hostname mDNS_SetFQDN(m); LogMsg("Local Hostname %#s.local already in use; will try %#s.local instead", oldlabel.c, m->hostlabel.c); } else if (result == mStatus_MemFree) { // .local hostnames do not require goodbyes - we ignore the MemFree (which is sent directly by // mDNS_Deregister_internal), and allow the caller to deallocate immediately following mDNS_DeadvertiseInterface debugf("mDNS_HostNameCallback: MemFree (ignored)"); } else LogMsg("mDNS_HostNameCallback: Unknown error %d for registration of record %s", result, rr->resrec.name->c); } #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) mDNSlocal void mDNS_RandomizedHostNameCallback(mDNS *const m, AuthRecord *const addrRecord, const mStatus result) { (void)addrRecord; // Unused parameter if (result == mStatus_NameConflict) { AuthRecord *rr; domainlabel newUUIDLabel; GetRandomUUIDLabel(&newUUIDLabel); if (SameDomainLabel(newUUIDLabel.c, m->RandomizedHostname.c)) { IncrementLabelSuffix(&newUUIDLabel, mDNSfalse); } mDNS_Lock(m); m->RandomizedHostname.c[0] = 0; AppendDomainLabel(&m->RandomizedHostname, &newUUIDLabel); AppendLiteralLabelString(&m->RandomizedHostname, "local"); DeadvertiseAllInterfaceRecords(m, kDeadvertiseFlag_RandHostname); AdvertiseNecessaryInterfaceRecords(m); for (rr = m->ResourceRecords; rr; rr = rr->next) { if (rr->AutoTarget && AuthRecordIncludesOrIsAWDL(rr)) UpdateTargetHostName(m, rr); } for (rr = m->DuplicateRecords; rr; rr = rr->next) { if (rr->AutoTarget && AuthRecordIncludesOrIsAWDL(rr)) UpdateTargetHostName(m, rr); } mDNS_Unlock(m); } } #endif mDNSlocal void UpdateInterfaceProtocols(mDNS *const m, NetworkInterfaceInfo *active) { NetworkInterfaceInfo *intf; active->IPv4Available = mDNSfalse; active->IPv6Available = mDNSfalse; for (intf = m->HostInterfaces; intf; intf = intf->next) if (intf->InterfaceID == active->InterfaceID) { if (intf->ip.type == mDNSAddrType_IPv4 && intf->McastTxRx) active->IPv4Available = mDNStrue; if (intf->ip.type == mDNSAddrType_IPv6 && intf->McastTxRx) active->IPv6Available = mDNStrue; } } mDNSlocal void RestartRecordGetZoneData(mDNS * const m) { AuthRecord *rr; LogInfo("RestartRecordGetZoneData: ResourceRecords"); for (rr = m->ResourceRecords; rr; rr=rr->next) if (AuthRecord_uDNS(rr) && rr->state != regState_NoTarget) { debugf("RestartRecordGetZoneData: StartGetZoneData for %##s", rr->resrec.name->c); // Zero out the updateid so that if we have a pending response from the server, it won't // be accepted as a valid response. If we accept the response, we might free the new "nta" if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); } rr->nta = StartGetZoneData(m, rr->resrec.name, ZoneServiceUpdate, RecordRegistrationGotZoneData, rr); } } mDNSlocal void InitializeNetWakeState(mDNS *const m, NetworkInterfaceInfo *set) { int i; // We initialize ThisQInterval to -1 indicating that the question has not been started // yet. If the question (browse) is started later during interface registration, it will // be stopped during interface deregistration. We can't sanity check to see if the // question has been stopped or not before initializing it to -1 because we need to // initialize it to -1 the very first time. set->NetWakeBrowse.ThisQInterval = -1; for (i=0; i<3; i++) { set->NetWakeResolve[i].ThisQInterval = -1; set->SPSAddr[i].type = mDNSAddrType_None; } set->NextSPSAttempt = -1; set->NextSPSAttemptTime = m->timenow; } mDNSexport void mDNS_ActivateNetWake_internal(mDNS *const m, NetworkInterfaceInfo *set) { NetworkInterfaceInfo *p = m->HostInterfaces; while (p && p != set) p=p->next; if (!p) { LogMsg("mDNS_ActivateNetWake_internal: NetworkInterfaceInfo %p not found in active list", set); return; } if (set->InterfaceActive) { LogSPS("ActivateNetWake for %s (%#a)", set->ifname, &set->ip); mDNS_StartBrowse_internal(m, &set->NetWakeBrowse, &SleepProxyServiceType, &localdomain, set->InterfaceID, 0, mDNSfalse, mDNSfalse, m->SPSBrowseCallback, set); } } mDNSexport void mDNS_DeactivateNetWake_internal(mDNS *const m, NetworkInterfaceInfo *set) { NetworkInterfaceInfo *p = m->HostInterfaces; while (p && p != set) p=p->next; if (!p) { LogMsg("mDNS_DeactivateNetWake_internal: NetworkInterfaceInfo %p not found in active list", set); return; } // Note: We start the browse only if the interface is NetWake capable and we use this to // stop the resolves also. Hence, the resolves should not be started without the browse // being started i.e, resolves should not happen unless NetWake capable which is // guaranteed by BeginSleepProcessing. if (set->NetWakeBrowse.ThisQInterval >= 0) { int i; LogSPS("DeactivateNetWake for %s (%#a)", set->ifname, &set->ip); // Stop our browse and resolve operations mDNS_StopQuery_internal(m, &set->NetWakeBrowse); for (i=0; i<3; i++) if (set->NetWakeResolve[i].ThisQInterval >= 0) mDNS_StopQuery_internal(m, &set->NetWakeResolve[i]); // Make special call to the browse callback to let it know it can to remove all records for this interface if (m->SPSBrowseCallback) { mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback m->SPSBrowseCallback(m, &set->NetWakeBrowse, mDNSNULL, QC_rmv); mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again } // Reset our variables back to initial state, so we're ready for when NetWake is turned back on // (includes resetting NetWakeBrowse.ThisQInterval back to -1) InitializeNetWakeState(m, set); } } mDNSexport mStatus mDNS_RegisterInterface(mDNS *const m, NetworkInterfaceInfo *set, InterfaceActivationSpeed activationSpeed) { AuthRecord *rr; mDNSBool FirstOfType = mDNStrue; NetworkInterfaceInfo **p = &m->HostInterfaces; if (!set->InterfaceID) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_ERROR, "Tried to register a NetworkInterfaceInfo with zero InterfaceID - ifaddr: " PRI_IP_ADDR, &set->ip); return(mStatus_Invalid); } if (!mDNSAddressIsValidNonZero(&set->mask)) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_ERROR, "Tried to register a NetworkInterfaceInfo with invalid mask - ifaddr: " PRI_IP_ADDR ", ifmask: " PUB_IP_ADDR, &set->ip, &set->mask); return(mStatus_Invalid); } mDNS_Lock(m); // Assume this interface will be active now, unless we find a duplicate already in the list set->InterfaceActive = mDNStrue; set->IPv4Available = (mDNSu8)(set->ip.type == mDNSAddrType_IPv4 && set->McastTxRx); set->IPv6Available = (mDNSu8)(set->ip.type == mDNSAddrType_IPv6 && set->McastTxRx); InitializeNetWakeState(m, set); // Scan list to see if this InterfaceID is already represented while (*p) { if (*p == set) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_ERROR, "Tried to register a NetworkInterfaceInfo that's already in the list - " "ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, set->ifname, &set->ip); mDNS_Unlock(m); return(mStatus_AlreadyRegistered); } if ((*p)->InterfaceID == set->InterfaceID) { // This InterfaceID already represented by a different interface in the list, so mark this instance inactive for now set->InterfaceActive = mDNSfalse; if (set->ip.type == (*p)->ip.type) FirstOfType = mDNSfalse; if (set->ip.type == mDNSAddrType_IPv4 && set->McastTxRx) (*p)->IPv4Available = mDNStrue; if (set->ip.type == mDNSAddrType_IPv6 && set->McastTxRx) (*p)->IPv6Available = mDNStrue; } p=&(*p)->next; } set->next = mDNSNULL; *p = set; if (set->Advertise) AdvertiseInterfaceIfNeeded(m, set); if (set->InterfaceActive) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_INFO, "Interface not represented in list; marking active and retriggering queries - " "ifid: %d, ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, IIDPrintable(set->InterfaceID), set->ifname, &set->ip); } else { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_INFO, "Interface already represented in list - " "ifid: %d, ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, IIDPrintable(set->InterfaceID), set->ifname, &set->ip); } if (set->NetWake) mDNS_ActivateNetWake_internal(m, set); // In early versions of OS X the IPv6 address remains on an interface even when the interface is turned off, // giving the false impression that there's an active representative of this interface when there really isn't. // Therefore, when registering an interface, we want to re-trigger our questions and re-probe our Resource Records, // even if we believe that we previously had an active representative of this interface. if (set->McastTxRx && (FirstOfType || set->InterfaceActive)) { DNSQuestion *q; // Normally, after an interface comes up, we pause half a second before beginning probing. // This is to guard against cases where there's rapid interface changes, where we could be confused by // seeing packets we ourselves sent just moments ago (perhaps when this interface had a different address) // which are then echoed back after a short delay by some Ethernet switches and some 802.11 base stations. // We don't want to do a probe, and then see a stale echo of an announcement we ourselves sent, // and think it's a conflicting answer to our probe. // In the case of a flapping interface, we pause for five seconds, and reduce the announcement count to one packet. mDNSs32 probedelay; mDNSu8 numannounce; switch (activationSpeed) { case FastActivation: probedelay = (mDNSs32)0; numannounce = InitialAnnounceCount; LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_DEFAULT, "Using fast activation for DirectLink interface - ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, set->ifname, &set->ip); break; #if MDNSRESPONDER_SUPPORTS(APPLE, SLOW_ACTIVATION) case SlowActivation: probedelay = mDNSPlatformOneSecond * 5; numannounce = (mDNSu8)1; LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_DEFAULT, "Frequent transitions for interface, doing slow activation - " "ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, set->ifname, &set->ip); m->mDNSStats.InterfaceUpFlap++; break; #endif case NormalActivation: default: probedelay = mDNSPlatformOneSecond / 2; numannounce = InitialAnnounceCount; break; } LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_INFO, "Interface probe will be delayed - ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR ", probe delay: %d", set->ifname, &set->ip, probedelay); // No probe or sending suppression on DirectLink type interfaces. if (activationSpeed == FastActivation) { m->SuppressSending = 0; m->SuppressProbes = 0; } else { // Use a small amount of randomness: // In the case of a network administrator turning on an Ethernet hub so that all the // connected machines establish link at exactly the same time, we don't want them all // to go and hit the network with identical queries at exactly the same moment. // We set a random delay of up to InitialQuestionInterval (1/3 second). // We must *never* set m->SuppressSending to more than that (or set it repeatedly in a way // that causes mDNSResponder to remain in a prolonged state of SuppressSending, because // suppressing packet sending for more than about 1/3 second can cause protocol correctness // to start to break down (e.g. we don't answer probes fast enough, and get name conflicts). // See mDNS: m->SuppressSending set too enthusiastically if (!m->SuppressSending) m->SuppressSending = m->timenow + (mDNSs32)mDNSRandom((mDNSu32)InitialQuestionInterval); if (m->SuppressProbes == 0 || m->SuppressProbes - NonZeroTime(m->timenow + probedelay) < 0) m->SuppressProbes = NonZeroTime(m->timenow + probedelay); } // Include OWNER option in packets for 60 seconds after connecting to the network. Setting // it here also handles the wake up case as the network link comes UP after waking causing // us to reconnect to the network. If we do this as part of the wake up code, it is possible // that the network link comes UP after 60 seconds and we never set the OWNER option m->AnnounceOwner = NonZeroTime(m->timenow + 60 * mDNSPlatformOneSecond); LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_DEBUG, "Setting AnnounceOwner"); m->mDNSStats.InterfaceUp++; for (q = m->Questions; q; q=q->next) // Scan our list of questions { if (mDNSOpaque16IsZero(q->TargetQID)) { if (!q->InterfaceID || q->InterfaceID == set->InterfaceID) // If non-specific Q, or Q on this specific interface, { // then reactivate this question #if MDNSRESPONDER_SUPPORTS(APPLE, SLOW_ACTIVATION) // If flapping, delay between first and second queries is nine seconds instead of one second mDNSBool dodelay = (activationSpeed == SlowActivation) && (q->FlappingInterface1 == set->InterfaceID || q->FlappingInterface2 == set->InterfaceID); mDNSs32 initial = dodelay ? InitialQuestionInterval * QuestionIntervalStep2 : InitialQuestionInterval; mDNSs32 qdelay = dodelay ? kDefaultQueryDelayTimeForFlappingInterface : 0; if (dodelay) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_INFO, "No cache records expired for the question " PRI_DM_NAME " (" PUB_S ");" " delaying it by %d seconds", DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), qdelay); } #else mDNSs32 initial = InitialQuestionInterval; mDNSs32 qdelay = 0; #endif if (!q->ThisQInterval || q->ThisQInterval > initial) { q->ThisQInterval = initial; q->RequestUnicast = kDefaultRequestUnicastCount; } q->LastQTime = m->timenow - q->ThisQInterval + qdelay; q->RecentAnswerPkts = 0; SetNextQueryTime(m,q); } } } // For all our non-specific authoritative resource records (and any dormant records specific to this interface) // we now need them to re-probe if necessary, and then re-announce. for (rr = m->ResourceRecords; rr; rr=rr->next) { if (!rr->resrec.InterfaceID || rr->resrec.InterfaceID == set->InterfaceID) { mDNSCoreRestartRegistration(m, rr, numannounce); } } } RestartRecordGetZoneData(m); mDNS_UpdateAllowSleep(m); mDNS_Unlock(m); return(mStatus_NoError); } mDNSlocal void AdjustAddressRecordSetsEx(mDNS *const m, NetworkInterfaceInfo *removedIntf, mDNSBool forRandHostname) { NetworkInterfaceInfo *intf; const AuthRecord *oldAR; AuthRecord *newAR; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (mDNSPlatformInterfaceIsAWDL(removedIntf->InterfaceID)) return; #endif oldAR = GetInterfaceAddressRecord(removedIntf, forRandHostname); newAR = GetFirstAddressRecordEx(m, forRandHostname); for (intf = m->HostInterfaces; intf; intf = intf->next) { AuthRecord *ar; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) if (mDNSPlatformInterfaceIsAWDL(intf->InterfaceID)) continue; #endif ar = GetInterfaceAddressRecord(intf, forRandHostname); if (ar->RRSet == oldAR) { ar->RRSet = newAR ? newAR : ar; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "Changed RRSet for " PRI_S, ARDisplayString(m, ar)); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "New RRSet: " PRI_S, ARDisplayString(m, ar->RRSet)); } } } #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) #define AdjustAddressRecordSetsForRandHostname(M, REMOVED_INTF) AdjustAddressRecordSetsEx(M, REMOVED_INTF, mDNStrue) #endif #define AdjustAddressRecordSets(M, REMOVED_INTF) AdjustAddressRecordSetsEx(M, REMOVED_INTF, mDNSfalse) // Note: mDNS_DeregisterInterface calls mDNS_Deregister_internal which can call a user callback, which may change // the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSexport void mDNS_DeregisterInterface(mDNS *const m, NetworkInterfaceInfo *set, InterfaceActivationSpeed activationSpeed) { #if !MDNSRESPONDER_SUPPORTS(APPLE, SLOW_ACTIVATION) (void)activationSpeed; // Unused parameter #endif NetworkInterfaceInfo **p = &m->HostInterfaces; mDNSBool revalidate = mDNSfalse; NetworkInterfaceInfo *intf; mDNS_Lock(m); // Find this record in our list while (*p && *p != set) p=&(*p)->next; if (!*p) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_DEBUG, "NetworkInterfaceInfo not found in list"); mDNS_Unlock(m); return; } mDNS_DeactivateNetWake_internal(m, set); // Unlink this record from our list *p = (*p)->next; set->next = mDNSNULL; if (!set->InterfaceActive) { // If this interface not the active member of its set, update the v4/v6Available flags for the active member for (intf = m->HostInterfaces; intf; intf = intf->next) if (intf->InterfaceActive && intf->InterfaceID == set->InterfaceID) UpdateInterfaceProtocols(m, intf); } else { intf = FirstInterfaceForID(m, set->InterfaceID); if (intf) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_INFO, "Another representative of InterfaceID exists - ifid: %d, ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, IIDPrintable(set->InterfaceID), set->ifname, &set->ip); if (intf->InterfaceActive) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_ERROR, "intf->InterfaceActive already set for interface - ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, set->ifname, &set->ip); } intf->InterfaceActive = mDNStrue; UpdateInterfaceProtocols(m, intf); if (intf->NetWake) mDNS_ActivateNetWake_internal(m, intf); // See if another representative *of the same type* exists. If not, we mave have gone from // dual-stack to v6-only (or v4-only) so we need to reconfirm which records are still valid. for (intf = m->HostInterfaces; intf; intf = intf->next) if (intf->InterfaceID == set->InterfaceID && intf->ip.type == set->ip.type) break; if (!intf) revalidate = mDNStrue; } else { mDNSu32 slot; CacheGroup *cg; CacheRecord *rr; DNSQuestion *q; #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) mDNSu32 cacheHitMulticastCount = 0; mDNSu32 cacheMissMulticastCount = 0; mDNSu32 cacheHitUnicastCount = 0; mDNSu32 cacheMissUnicastCount = 0; #endif LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_INFO, "Last representative of InterfaceID deregistered; marking questions etc. dormant - " "ifid: %d, ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, IIDPrintable(set->InterfaceID), set->ifname, &set->ip); m->mDNSStats.InterfaceDown++; #if MDNSRESPONDER_SUPPORTS(APPLE, SLOW_ACTIVATION) if (set->McastTxRx && (activationSpeed == SlowActivation)) { LogRedact(MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_DEFAULT, "Frequent transitions for interface - ifname: " PUB_S ", ifaddr: " PRI_IP_ADDR, set->ifname, &set->ip); m->mDNSStats.InterfaceDownFlap++; } #endif // 1. Deactivate any questions specific to this interface, and tag appropriate questions // so that mDNS_RegisterInterface() knows how swiftly it needs to reactivate them for (q = m->Questions; q; q=q->next) { if (mDNSOpaque16IsZero(q->TargetQID)) // Only deactivate multicast quesstions. (Unicast questions are stopped when/if the associated DNS server group goes away.) { if (q->InterfaceID == set->InterfaceID) q->ThisQInterval = 0; if (!q->InterfaceID || q->InterfaceID == set->InterfaceID) { q->FlappingInterface2 = q->FlappingInterface1; q->FlappingInterface1 = set->InterfaceID; // Keep history of the last two interfaces to go away } } } // 2. Flush any cache records received on this interface revalidate = mDNSfalse; // Don't revalidate if we're flushing the records FORALL_CACHERECORDS(slot, cg, rr) { if (rr->resrec.InterfaceID == set->InterfaceID) { #if MDNSRESPONDER_SUPPORTS(APPLE, SLOW_ACTIVATION) // If this interface is deemed flapping, // postpone deleting the cache records in case the interface comes back again if (set->McastTxRx && (activationSpeed == SlowActivation)) { // For a flapping interface we want these records to go away after // kDefaultReconfirmTimeForFlappingInterface seconds if they are not reconfirmed. mDNS_Reconfirm_internal(m, rr, kDefaultReconfirmTimeForFlappingInterface); // We set UnansweredQueries = MaxUnansweredQueries so we don't waste time doing any queries for them -- // if the interface does come back, any relevant questions will be reactivated anyway rr->UnansweredQueries = MaxUnansweredQueries; } else #endif { #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) if (rr->LastCachedAnswerTime) { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (rr->resrec.dnsservice) cacheHitUnicastCount++; #else if (rr->resrec.rDNSServer) cacheHitUnicastCount++; #endif else cacheHitMulticastCount++; } else { #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (rr->resrec.dnsservice) cacheMissUnicastCount++; #else if (rr->resrec.rDNSServer) cacheMissUnicastCount++; #endif else cacheMissMulticastCount++; } #endif mDNS_PurgeCacheResourceRecord(m, rr); } } } #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) dnssd_analytics_update_cache_usage_counts(cacheHitMulticastCount, cacheMissMulticastCount, cacheHitUnicastCount, cacheMissUnicastCount); #endif } } // If we still have address records referring to this one, update them. // This is safe, because this NetworkInterfaceInfo has already been unlinked from the list, // so the call to AdjustAddressRecordSets*() won’t accidentally find it. AdjustAddressRecordSets(m, set); #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) AdjustAddressRecordSetsForRandHostname(m, set); #endif // If we were advertising on this interface, deregister those address and reverse-lookup records now if (set->Advertise) DeadvertiseInterface(m, set, kDeadvertiseFlag_All); // If we have any cache records received on this interface that went away, then re-verify them. // In some versions of OS X the IPv6 address remains on an interface even when the interface is turned off, // giving the false impression that there's an active representative of this interface when there really isn't. // Don't need to do this when shutting down, because *all* interfaces are about to go away if (revalidate && !m->ShutdownTime) { mDNSu32 slot; CacheGroup *cg; CacheRecord *rr; FORALL_CACHERECORDS(slot, cg, rr) if (rr->resrec.InterfaceID == set->InterfaceID) mDNS_Reconfirm_internal(m, rr, kDefaultReconfirmTimeForFlappingInterface); } mDNS_UpdateAllowSleep(m); mDNS_Unlock(m); } mDNSlocal void ServiceCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { ServiceRecordSet *sr = (ServiceRecordSet *)rr->RecordContext; (void)m; // Unused parameter #if MDNS_DEBUGMSGS { char *msg = "Unknown result"; if (result == mStatus_NoError) msg = "Name Registered"; else if (result == mStatus_NameConflict) msg = "Name Conflict"; else if (result == mStatus_MemFree) msg = "Memory Free"; debugf("ServiceCallback: %##s (%s) %s (%d)", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), msg, result); } #endif // Only pass on the NoError acknowledgement for the SRV record (when it finishes probing) if (result == mStatus_NoError && rr != &sr->RR_SRV) return; // If we got a name conflict on either SRV or TXT, forcibly deregister this service, and record that we did that if (result == mStatus_NameConflict) { sr->Conflict = mDNStrue; // Record that this service set had a conflict mDNS_DeregisterService(m, sr); // Unlink the records from our list return; } if (result == mStatus_MemFree) { // If the SRV/TXT/PTR records, or the _services._dns-sd._udp record, or any of the subtype PTR records, // are still in the process of deregistering, don't pass on the NameConflict/MemFree message until // every record is finished cleaning up. mDNSu32 i; ExtraResourceRecord *e = sr->Extras; if (sr->RR_SRV.resrec.RecordType != kDNSRecordTypeUnregistered) return; if (sr->RR_TXT.resrec.RecordType != kDNSRecordTypeUnregistered) return; if (sr->RR_PTR.resrec.RecordType != kDNSRecordTypeUnregistered) return; if (sr->RR_ADV.resrec.RecordType != kDNSRecordTypeUnregistered) return; for (i=0; iNumSubTypes; i++) if (sr->SubTypes[i].resrec.RecordType != kDNSRecordTypeUnregistered) return; while (e) { if (e->r.resrec.RecordType != kDNSRecordTypeUnregistered) return; e = e->next; } // If this ServiceRecordSet was forcibly deregistered, and now its memory is ready for reuse, // then we can now report the NameConflict to the client if (sr->Conflict) result = mStatus_NameConflict; } LogInfo("ServiceCallback: All records %s for %##s", (result == mStatus_MemFree ? "Unregistered" : "Registered"), sr->RR_PTR.resrec.name->c); // CAUTION: MUST NOT do anything more with sr after calling sr->Callback(), because the client's callback // function is allowed to do anything, including deregistering this service and freeing its memory. if (sr->ServiceCallback) sr->ServiceCallback(m, sr, result); } mDNSlocal void NSSCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { ServiceRecordSet *sr = (ServiceRecordSet *)rr->RecordContext; if (sr->ServiceCallback) sr->ServiceCallback(m, sr, result); } // Derive AuthRecType from the kDNSServiceFlags* values. mDNSlocal AuthRecType setAuthRecType(mDNSInterfaceID InterfaceID, mDNSu32 flags) { AuthRecType artype; if (InterfaceID == mDNSInterface_LocalOnly) artype = AuthRecordLocalOnly; else if (InterfaceID == mDNSInterface_P2P || InterfaceID == mDNSInterface_BLE) artype = AuthRecordP2P; else if ((InterfaceID == mDNSInterface_Any) && (flags & kDNSServiceFlagsIncludeP2P) && (flags & kDNSServiceFlagsIncludeAWDL)) artype = AuthRecordAnyIncludeAWDLandP2P; else if ((InterfaceID == mDNSInterface_Any) && (flags & kDNSServiceFlagsIncludeP2P)) artype = AuthRecordAnyIncludeP2P; else if ((InterfaceID == mDNSInterface_Any) && (flags & kDNSServiceFlagsIncludeAWDL)) artype = AuthRecordAnyIncludeAWDL; else artype = AuthRecordAny; return artype; } // Note: // Name is first label of domain name (any dots in the name are actual dots, not label separators) // Type is service type (e.g. "_ipp._tcp.") // Domain is fully qualified domain name (i.e. ending with a null label) // We always register a TXT, even if it is empty (so that clients are not // left waiting forever looking for a nonexistent record.) // If the host parameter is mDNSNULL or the root domain (ASCII NUL), // then the default host name (m->MulticastHostname) is automatically used // If the optional target host parameter is set, then the storage it points to must remain valid for the lifetime of the service registration mDNSexport mStatus mDNS_RegisterService(mDNS *const m, ServiceRecordSet *sr, const domainlabel *const name, const domainname *const type, const domainname *const domain, const domainname *const host, mDNSIPPort port, RData *const txtrdata, const mDNSu8 txtinfo[], mDNSu16 txtlen, AuthRecord *SubTypes, mDNSu32 NumSubTypes, mDNSInterfaceID InterfaceID, mDNSServiceCallback Callback, void *Context, mDNSu32 flags) { mStatus err; mDNSu32 i; AuthRecType artype; mDNSu8 recordType = (flags & kDNSServiceFlagsKnownUnique) ? kDNSRecordTypeKnownUnique : kDNSRecordTypeUnique; sr->ServiceCallback = Callback; sr->ServiceContext = Context; sr->Conflict = mDNSfalse; sr->Extras = mDNSNULL; sr->NumSubTypes = NumSubTypes; sr->SubTypes = SubTypes; sr->flags = flags; artype = setAuthRecType(InterfaceID, flags); // Initialize the AuthRecord objects to sane values // Need to initialize everything correctly *before* making the decision whether to do a RegisterNoSuchService and bail out mDNS_SetupResourceRecord(&sr->RR_ADV, mDNSNULL, InterfaceID, kDNSType_PTR, kStandardTTL, kDNSRecordTypeAdvisory, artype, ServiceCallback, sr); mDNS_SetupResourceRecord(&sr->RR_PTR, mDNSNULL, InterfaceID, kDNSType_PTR, kStandardTTL, kDNSRecordTypeShared, artype, ServiceCallback, sr); if (flags & kDNSServiceFlagsWakeOnlyService) { sr->RR_PTR.AuthFlags = AuthFlagsWakeOnly; } mDNS_SetupResourceRecord(&sr->RR_SRV, mDNSNULL, InterfaceID, kDNSType_SRV, kHostNameTTL, recordType, artype, ServiceCallback, sr); mDNS_SetupResourceRecord(&sr->RR_TXT, txtrdata, InterfaceID, kDNSType_TXT, kStandardTTL, recordType, artype, ServiceCallback, sr); // If port number is zero, that means the client is really trying to do a RegisterNoSuchService if (mDNSIPPortIsZero(port)) return(mDNS_RegisterNoSuchService(m, &sr->RR_SRV, name, type, domain, mDNSNULL, InterfaceID, NSSCallback, sr, flags)); // If the caller is registering an oversized TXT record, // it is the caller's responsibility to allocate a ServiceRecordSet structure that is large enough for it if (sr->RR_TXT.resrec.rdata->MaxRDLength < txtlen) sr->RR_TXT.resrec.rdata->MaxRDLength = txtlen; // Set up the record names // For now we only create an advisory record for the main type, not for subtypes // We need to gain some operational experience before we decide if there's a need to create them for subtypes too if (ConstructServiceName(&sr->RR_ADV.namestorage, (const domainlabel*)"\x09_services", (const domainname*)"\x07_dns-sd\x04_udp", domain) == mDNSNULL) return(mStatus_BadParamErr); if (ConstructServiceName(&sr->RR_PTR.namestorage, mDNSNULL, type, domain) == mDNSNULL) return(mStatus_BadParamErr); if (ConstructServiceName(&sr->RR_SRV.namestorage, name, type, domain) == mDNSNULL) return(mStatus_BadParamErr); AssignDomainName(&sr->RR_TXT.namestorage, sr->RR_SRV.resrec.name); // 1. Set up the ADV record rdata to advertise our service type AssignDomainName(&sr->RR_ADV.resrec.rdata->u.name, sr->RR_PTR.resrec.name); // 2. Set up the PTR record rdata to point to our service name // We set up two additionals, so when a client asks for this PTR we automatically send the SRV and the TXT too // Note: uDNS registration code assumes that Additional1 points to the SRV record AssignDomainName(&sr->RR_PTR.resrec.rdata->u.name, sr->RR_SRV.resrec.name); sr->RR_PTR.Additional1 = &sr->RR_SRV; sr->RR_PTR.Additional2 = &sr->RR_TXT; // 2a. Set up any subtype PTRs to point to our service name // If the client is using subtypes, it is the client's responsibility to have // already set the first label of the record name to the subtype being registered for (i=0; iSubTypes[i].resrec.name); st.c[1+st.c[0]] = 0; // Only want the first label, not the whole FQDN (particularly for mDNS_RenameAndReregisterService()) AppendDomainName(&st, type); mDNS_SetupResourceRecord(&sr->SubTypes[i], mDNSNULL, InterfaceID, kDNSType_PTR, kStandardTTL, kDNSRecordTypeShared, artype, ServiceCallback, sr); if (ConstructServiceName(&sr->SubTypes[i].namestorage, mDNSNULL, &st, domain) == mDNSNULL) return(mStatus_BadParamErr); AssignDomainName(&sr->SubTypes[i].resrec.rdata->u.name, &sr->RR_SRV.namestorage); sr->SubTypes[i].Additional1 = &sr->RR_SRV; sr->SubTypes[i].Additional2 = &sr->RR_TXT; } // 3. Set up the SRV record rdata. sr->RR_SRV.resrec.rdata->u.srv.priority = 0; sr->RR_SRV.resrec.rdata->u.srv.weight = 0; sr->RR_SRV.resrec.rdata->u.srv.port = port; // Setting AutoTarget tells DNS that the target of this SRV is to be automatically kept in sync with our host name if (host && host->c[0]) AssignDomainName(&sr->RR_SRV.resrec.rdata->u.srv.target, host); else { sr->RR_SRV.AutoTarget = Target_AutoHost; sr->RR_SRV.resrec.rdata->u.srv.target.c[0] = '\0'; } // 4. Set up the TXT record rdata, // and set DependentOn because we're depending on the SRV record to find and resolve conflicts for us // Note: uDNS registration code assumes that DependentOn points to the SRV record if (txtinfo == mDNSNULL) sr->RR_TXT.resrec.rdlength = 0; else if (txtinfo != sr->RR_TXT.resrec.rdata->u.txt.c) { sr->RR_TXT.resrec.rdlength = txtlen; if (sr->RR_TXT.resrec.rdlength > sr->RR_TXT.resrec.rdata->MaxRDLength) return(mStatus_BadParamErr); mDNSPlatformMemCopy(sr->RR_TXT.resrec.rdata->u.txt.c, txtinfo, txtlen); } sr->RR_TXT.DependentOn = &sr->RR_SRV; mDNS_Lock(m); // It is important that we register SRV first. uDNS assumes that SRV is registered first so // that if the SRV cannot find a target, rest of the records that belong to this service // will not be activated. err = mDNS_Register_internal(m, &sr->RR_SRV); // If we can't register the SRV record due to errors, bail out. It has not been inserted in // any list and hence no need to deregister. We could probably do similar checks for other // records below and bail out. For now, this seems to be sufficient to address rdar://9304275 if (err) { mDNS_Unlock(m); return err; } if (!err) err = mDNS_Register_internal(m, &sr->RR_TXT); // We register the RR_PTR last, because we want to be sure that in the event of a forced call to // mDNS_StartExit, the RR_PTR will be the last one to be forcibly deregistered, since that is what triggers // the mStatus_MemFree callback to ServiceCallback, which in turn passes on the mStatus_MemFree back to // the client callback, which is then at liberty to free the ServiceRecordSet memory at will. We need to // make sure we've deregistered all our records and done any other necessary cleanup before that happens. if (!err) err = mDNS_Register_internal(m, &sr->RR_ADV); for (i=0; iSubTypes[i]); if (!err) err = mDNS_Register_internal(m, &sr->RR_PTR); mDNS_Unlock(m); if (err) mDNS_DeregisterService(m, sr); return(err); } mDNSexport mStatus mDNS_AddRecordToService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, RData *rdata, mDNSu32 ttl, mDNSu32 flags) { ExtraResourceRecord **e; mStatus status; AuthRecType artype; mDNSInterfaceID InterfaceID = sr->RR_PTR.resrec.InterfaceID; ResourceRecord *rr; artype = setAuthRecType(InterfaceID, flags); extra->next = mDNSNULL; mDNS_SetupResourceRecord(&extra->r, rdata, sr->RR_PTR.resrec.InterfaceID, extra->r.resrec.rrtype, ttl, kDNSRecordTypeUnique, artype, ServiceCallback, sr); AssignDomainName(&extra->r.namestorage, sr->RR_SRV.resrec.name); mDNS_Lock(m); rr = mDNSNULL; if (extra->r.resrec.rrtype == kDNSType_TXT) { if (sr->RR_TXT.resrec.RecordType & kDNSRecordTypeUniqueMask) rr = &sr->RR_TXT.resrec; } else if (extra->r.resrec.rrtype == kDNSType_SRV) { if (sr->RR_SRV.resrec.RecordType & kDNSRecordTypeUniqueMask) rr = &sr->RR_SRV.resrec; } if (!rr) { ExtraResourceRecord *srExtra; for (srExtra = sr->Extras; srExtra; srExtra = srExtra->next) { if ((srExtra->r.resrec.rrtype == extra->r.resrec.rrtype) && (srExtra->r.resrec.RecordType & kDNSRecordTypeUniqueMask)) { rr = &srExtra->r.resrec; break; } } } if (rr && (extra->r.resrec.rroriginalttl != rr->rroriginalttl)) { LogMsg("mDNS_AddRecordToService: Correcting TTL from %4d to %4d for %s", extra->r.resrec.rroriginalttl, rr->rroriginalttl, RRDisplayString(m, &extra->r.resrec)); extra->r.resrec.rroriginalttl = rr->rroriginalttl; } e = &sr->Extras; while (*e) e = &(*e)->next; extra->r.DependentOn = &sr->RR_SRV; debugf("mDNS_AddRecordToService adding record to %##s %s %d", extra->r.resrec.name->c, DNSTypeName(extra->r.resrec.rrtype), extra->r.resrec.rdlength); status = mDNS_Register_internal(m, &extra->r); if (status == mStatus_NoError) *e = extra; mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_RemoveRecordFromService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, mDNSRecordCallback MemFreeCallback, void *Context) { ExtraResourceRecord **e; mStatus status; mDNS_Lock(m); e = &sr->Extras; while (*e && *e != extra) e = &(*e)->next; if (!*e) { debugf("mDNS_RemoveRecordFromService failed to remove record from %##s", extra->r.resrec.name->c); status = mStatus_BadReferenceErr; } else { debugf("mDNS_RemoveRecordFromService removing record from %##s", extra->r.resrec.name->c); extra->r.RecordCallback = MemFreeCallback; extra->r.RecordContext = Context; *e = (*e)->next; status = mDNS_Deregister_internal(m, &extra->r, mDNS_Dereg_normal); } mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_RenameAndReregisterService(mDNS *const m, ServiceRecordSet *const sr, const domainlabel *newname) { // Note: Don't need to use mDNS_Lock(m) here, because this code is just using public routines // mDNS_RegisterService() and mDNS_AddRecordToService(), which do the right locking internally. domainlabel name1, name2; domainname type, domain; const domainname *host = sr->RR_SRV.AutoTarget ? mDNSNULL : &sr->RR_SRV.resrec.rdata->u.srv.target; ExtraResourceRecord *extras = sr->Extras; mStatus err; DeconstructServiceName(sr->RR_SRV.resrec.name, &name1, &type, &domain); if (!newname) { name2 = name1; IncrementLabelSuffix(&name2, mDNStrue); newname = &name2; } if (SameDomainName(&domain, &localdomain)) debugf("%##s service renamed from \"%#s\" to \"%#s\"", type.c, name1.c, newname->c); else debugf("%##s service (domain %##s) renamed from \"%#s\" to \"%#s\"",type.c, domain.c, name1.c, newname->c); // If there's a pending TXT record update at this point, which can happen if a DNSServiceUpdateRecord() call was made // after the TXT record's deregistration, execute it now, otherwise it will be lost during the service re-registration. if (sr->RR_TXT.NewRData) CompleteRDataUpdate(m, &sr->RR_TXT); err = mDNS_RegisterService(m, sr, newname, &type, &domain, host, sr->RR_SRV.resrec.rdata->u.srv.port, (sr->RR_TXT.resrec.rdata != &sr->RR_TXT.rdatastorage) ? sr->RR_TXT.resrec.rdata : mDNSNULL, sr->RR_TXT.resrec.rdata->u.txt.c, sr->RR_TXT.resrec.rdlength, sr->SubTypes, sr->NumSubTypes, sr->RR_PTR.resrec.InterfaceID, sr->ServiceCallback, sr->ServiceContext, sr->flags); // mDNS_RegisterService() just reset sr->Extras to NULL. // Fortunately we already grabbed ourselves a copy of this pointer (above), so we can now run // through the old list of extra records, and re-add them to our freshly created service registration while (!err && extras) { ExtraResourceRecord *e = extras; extras = extras->next; err = mDNS_AddRecordToService(m, sr, e, e->r.resrec.rdata, e->r.resrec.rroriginalttl, 0); } return(err); } // Note: mDNS_DeregisterService calls mDNS_Deregister_internal which can call a user callback, // which may change the record list and/or question list. // Any code walking either list must use the CurrentQuestion and/or CurrentRecord mechanism to protect against this. mDNSexport mStatus mDNS_DeregisterService_drt(mDNS *const m, ServiceRecordSet *sr, mDNS_Dereg_type drt) { // If port number is zero, that means this was actually registered using mDNS_RegisterNoSuchService() if (mDNSIPPortIsZero(sr->RR_SRV.resrec.rdata->u.srv.port)) return(mDNS_DeregisterNoSuchService(m, &sr->RR_SRV)); if (sr->RR_PTR.resrec.RecordType == kDNSRecordTypeUnregistered) { debugf("Service set for %##s already deregistered", sr->RR_SRV.resrec.name->c); return(mStatus_BadReferenceErr); } else if (sr->RR_PTR.resrec.RecordType == kDNSRecordTypeDeregistering) { LogInfo("Service set for %##s already in the process of deregistering", sr->RR_SRV.resrec.name->c); // Avoid race condition: // If a service gets a conflict, then we set the Conflict flag to tell us to generate // an mStatus_NameConflict message when we get the mStatus_MemFree for our PTR record. // If the client happens to deregister the service in the middle of that process, then // we clear the flag back to the normal state, so that we deliver a plain mStatus_MemFree // instead of incorrectly promoting it to mStatus_NameConflict. // This race condition is exposed particularly when the conformance test generates // a whole batch of simultaneous conflicts across a range of services all advertised // using the same system default name, and if we don't take this precaution then // we end up incrementing m->nicelabel multiple times instead of just once. // Bug when auto-renaming Computer Name after name collision sr->Conflict = mDNSfalse; return(mStatus_NoError); } else { mDNSu32 i; mStatus status; ExtraResourceRecord *e; mDNS_Lock(m); e = sr->Extras; // We use mDNS_Dereg_repeat because, in the event of a collision, some or all of the // SRV, TXT, or Extra records could have already been automatically deregistered, and that's okay mDNS_Deregister_internal(m, &sr->RR_SRV, mDNS_Dereg_repeat); mDNS_Deregister_internal(m, &sr->RR_TXT, mDNS_Dereg_repeat); mDNS_Deregister_internal(m, &sr->RR_ADV, drt); // We deregister all of the extra records, but we leave the sr->Extras list intact // in case the client wants to do a RenameAndReregister and reinstate the registration while (e) { mDNS_Deregister_internal(m, &e->r, mDNS_Dereg_repeat); e = e->next; } for (i=0; iNumSubTypes; i++) mDNS_Deregister_internal(m, &sr->SubTypes[i], drt); status = mDNS_Deregister_internal(m, &sr->RR_PTR, drt); mDNS_Unlock(m); return(status); } } // Create a registration that asserts that no such service exists with this name. // This can be useful where there is a given function is available through several protocols. // For example, a printer called "Stuart's Printer" may implement printing via the "pdl-datastream" and "IPP" // protocols, but not via "LPR". In this case it would be prudent for the printer to assert the non-existence of an // "LPR" service called "Stuart's Printer". Without this precaution, another printer than offers only "LPR" printing // could inadvertently advertise its service under the same name "Stuart's Printer", which might be confusing for users. mDNSexport mStatus mDNS_RegisterNoSuchService(mDNS *const m, AuthRecord *const rr, const domainlabel *const name, const domainname *const type, const domainname *const domain, const domainname *const host, const mDNSInterfaceID InterfaceID, mDNSRecordCallback Callback, void *Context, mDNSu32 flags) { AuthRecType artype; artype = setAuthRecType(InterfaceID, flags); mDNS_SetupResourceRecord(rr, mDNSNULL, InterfaceID, kDNSType_SRV, kHostNameTTL, kDNSRecordTypeUnique, artype, Callback, Context); if (ConstructServiceName(&rr->namestorage, name, type, domain) == mDNSNULL) return(mStatus_BadParamErr); rr->resrec.rdata->u.srv.priority = 0; rr->resrec.rdata->u.srv.weight = 0; rr->resrec.rdata->u.srv.port = zeroIPPort; if (host && host->c[0]) AssignDomainName(&rr->resrec.rdata->u.srv.target, host); else rr->AutoTarget = Target_AutoHost; return(mDNS_Register(m, rr)); } mDNSexport mStatus mDNS_AdvertiseDomains(mDNS *const m, AuthRecord *rr, mDNS_DomainType DomainType, const mDNSInterfaceID InterfaceID, char *domname) { AuthRecType artype; if (InterfaceID == mDNSInterface_LocalOnly) artype = AuthRecordLocalOnly; else if (InterfaceID == mDNSInterface_P2P || InterfaceID == mDNSInterface_BLE) artype = AuthRecordP2P; else artype = AuthRecordAny; mDNS_SetupResourceRecord(rr, mDNSNULL, InterfaceID, kDNSType_PTR, kStandardTTL, kDNSRecordTypeShared, artype, mDNSNULL, mDNSNULL); if (!MakeDomainNameFromDNSNameString(&rr->namestorage, mDNS_DomainTypeNames[DomainType])) return(mStatus_BadParamErr); if (!MakeDomainNameFromDNSNameString(&rr->resrec.rdata->u.name, domname)) return(mStatus_BadParamErr); return(mDNS_Register(m, rr)); } mDNSlocal mDNSBool mDNS_IdUsedInResourceRecordsList(mDNS * const m, mDNSOpaque16 id) { AuthRecord *r; for (r = m->ResourceRecords; r; r=r->next) if (mDNSSameOpaque16(id, r->updateid)) return mDNStrue; return mDNSfalse; } mDNSlocal mDNSBool mDNS_IdUsedInQuestionsList(mDNS * const m, mDNSOpaque16 id) { DNSQuestion *q; for (q = m->Questions; q; q=q->next) if (mDNSSameOpaque16(id, q->TargetQID)) return mDNStrue; return mDNSfalse; } mDNSexport mDNSOpaque16 mDNS_NewMessageID(mDNS * const m) { mDNSOpaque16 id; int i; for (i=0; i<10; i++) { id = mDNSOpaque16fromIntVal(1 + (mDNSu16)mDNSRandom(0xFFFE)); if (!mDNS_IdUsedInResourceRecordsList(m, id) && !mDNS_IdUsedInQuestionsList(m, id)) break; } debugf("mDNS_NewMessageID: %5d", mDNSVal16(id)); return id; } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Sleep Proxy Server #endif mDNSlocal void RestartARPProbing(mDNS *const m, AuthRecord *const rr) { // If we see an ARP from a machine we think is sleeping, then either // (i) the machine has woken, or // (ii) it's just a stray old packet from before the machine slept // To handle the second case, we reset ProbeCount, so we'll suppress our own answers for a while, to avoid // generating ARP conflicts with a waking machine, and set rr->LastAPTime so we'll start probing again in 10 seconds. // If the machine has just woken then we'll discard our records when we see the first new mDNS probe from that machine. // If it was a stray old packet, then after 10 seconds we'll probe again and then start answering ARPs again. In this case we *do* // need to send new ARP Announcements, because the owner's ARP broadcasts will have updated neighboring ARP caches, so we need to // re-assert our (temporary) ownership of that IP address in order to receive subsequent packets addressed to that IPv4 address. rr->resrec.RecordType = kDNSRecordTypeUnique; rr->ProbeCount = DefaultProbeCountForTypeUnique; rr->ProbeRestartCount++; // If we haven't started announcing yet (and we're not already in ten-second-delay mode) the machine is probably // still going to sleep, so we just reset rr->ProbeCount so we'll continue probing until it stops responding. // If we *have* started announcing, the machine is probably in the process of waking back up, so in that case // we're more cautious and we wait ten seconds before probing it again. We do this because while waking from // sleep, some network interfaces tend to lose or delay inbound packets, and without this delay, if the waking machine // didn't answer our three probes within three seconds then we'd announce and cause it an unnecessary address conflict. if (rr->AnnounceCount == InitialAnnounceCount && m->timenow - rr->LastAPTime >= 0) InitializeLastAPTime(m, rr); else { rr->AnnounceCount = InitialAnnounceCount; rr->ThisAPInterval = mDNSPlatformOneSecond; rr->LastAPTime = m->timenow + mDNSPlatformOneSecond * 9; // Send first packet at rr->LastAPTime + rr->ThisAPInterval, i.e. 10 seconds from now SetNextAnnounceProbeTime(m, rr); } } mDNSlocal void mDNSCoreReceiveRawARP(mDNS *const m, const ARP_EthIP *const arp, const mDNSInterfaceID InterfaceID) { static const mDNSOpaque16 ARP_op_request = { { 0, 1 } }; AuthRecord *rr; NetworkInterfaceInfo *intf = FirstInterfaceForID(m, InterfaceID); if (!intf) return; mDNS_Lock(m); // Pass 1: // Process ARP Requests and Probes (but not Announcements), and generate an ARP Reply if necessary. // We also process ARPs from our own kernel (and 'answer' them by injecting a local ARP table entry) // We ignore ARP Announcements here -- Announcements are not questions, they're assertions, so we don't need to answer them. // The times we might need to react to an ARP Announcement are: // (i) as an indication that the host in question has not gone to sleep yet (so we should delay beginning to proxy for it) or // (ii) if it's a conflicting Announcement from another host // -- and we check for these in Pass 2 below. if (mDNSSameOpaque16(arp->op, ARP_op_request) && !mDNSSameIPv4Address(arp->spa, arp->tpa)) { for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.InterfaceID == InterfaceID && rr->resrec.RecordType != kDNSRecordTypeDeregistering && rr->AddressProxy.type == mDNSAddrType_IPv4 && mDNSSameIPv4Address(rr->AddressProxy.ip.v4, arp->tpa)) { static const char msg1[] = "ARP Req from owner -- re-probing"; static const char msg2[] = "Ignoring ARP Request from "; static const char msg3[] = "Creating Local ARP Cache entry "; static const char msg4[] = "Answering ARP Request from "; const char *const msg = mDNSSameEthAddress(&arp->sha, &rr->WakeUp.IMAC) ? msg1 : (rr->AnnounceCount == InitialAnnounceCount) ? msg2 : mDNSSameEthAddress(&arp->sha, &intf->MAC) ? msg3 : msg4; LogMsg("Arp %-7s %s %.6a %.4a for %.4a -- H-MAC %.6a I-MAC %.6a %s", intf->ifname, msg, arp->sha.b, arp->spa.b, arp->tpa.b, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); if (msg == msg1) { if ( rr->ProbeRestartCount < MAX_PROBE_RESTARTS) RestartARPProbing(m, rr); else LogSPS("Reached maximum number of restarts for probing - %s", ARDisplayString(m,rr)); } else if (msg == msg3) { mDNSPlatformSetLocalAddressCacheEntry(&rr->AddressProxy, &rr->WakeUp.IMAC, InterfaceID); } else if (msg == msg4) { mDNSv4Addr tpa = arp->tpa; mDNSv4Addr spa = arp->spa; SendARP(m, 2, rr, &tpa, &arp->sha, &spa, &arp->sha); } } } // Pass 2: // For all types of ARP packet we check the Sender IP address to make sure it doesn't conflict with any AddressProxy record we're holding. // (Strictly speaking we're only checking Announcement/Request/Reply packets, since ARP Probes have zero Sender IP address, // so by definition (and by design) they can never conflict with any real (i.e. non-zero) IP address). // We ignore ARPs we sent ourselves (Sender MAC address is our MAC address) because our own proxy ARPs do not constitute a conflict that we need to handle. // If we see an apparently conflicting ARP, we check the sender hardware address: // If the sender hardware address is the original owner this is benign, so we just suppress our own proxy answering for a while longer. // If the sender hardware address is *not* the original owner, then this is a conflict, and we need to wake the sleeping machine to handle it. if (mDNSSameEthAddress(&arp->sha, &intf->MAC)) debugf("ARP from self for %.4a", arp->tpa.b); else { if (!mDNSSameIPv4Address(arp->spa, zerov4Addr)) for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.InterfaceID == InterfaceID && rr->resrec.RecordType != kDNSRecordTypeDeregistering && rr->AddressProxy.type == mDNSAddrType_IPv4 && mDNSSameIPv4Address(rr->AddressProxy.ip.v4, arp->spa) && (rr->ProbeRestartCount < MAX_PROBE_RESTARTS)) { if (mDNSSameEthAddress(&zeroEthAddr, &rr->WakeUp.HMAC)) { LogMsg("%-7s ARP from %.6a %.4a for %.4a -- Invalid H-MAC %.6a I-MAC %.6a %s", intf->ifname, arp->sha.b, arp->spa.b, arp->tpa.b, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); } else { RestartARPProbing(m, rr); if (mDNSSameEthAddress(&arp->sha, &rr->WakeUp.IMAC)) { LogMsg("%-7s ARP %s from owner %.6a %.4a for %-15.4a -- re-starting probing for %s", intf->ifname, mDNSSameIPv4Address(arp->spa, arp->tpa) ? "Announcement " : mDNSSameOpaque16(arp->op, ARP_op_request) ? "Request " : "Response ", arp->sha.b, arp->spa.b, arp->tpa.b, ARDisplayString(m, rr)); } else { LogMsg("%-7s Conflicting ARP from %.6a %.4a for %.4a -- waking H-MAC %.6a I-MAC %.6a %s", intf->ifname, arp->sha.b, arp->spa.b, arp->tpa.b, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); ScheduleWakeup(m, rr->resrec.InterfaceID, &rr->WakeUp.HMAC); } } } } mDNS_Unlock(m); } /* // Option 1 is Source Link Layer Address Option // Option 2 is Target Link Layer Address Option mDNSlocal const mDNSEthAddr *GetLinkLayerAddressOption(const IPv6NDP *const ndp, const mDNSu8 *const end, mDNSu8 op) { const mDNSu8 *options = (mDNSu8 *)(ndp+1); while (options < end) { debugf("NDP Option %02X len %2d %d", options[0], options[1], end - options); if (options[0] == op && options[1] == 1) return (const mDNSEthAddr*)(options+2); options += options[1] * 8; } return mDNSNULL; } */ mDNSlocal void mDNSCoreReceiveRawND(mDNS *const m, const mDNSEthAddr *const sha, const mDNSv6Addr *spa, const IPv6NDP *const ndp, const mDNSu8 *const end, const mDNSInterfaceID InterfaceID) { AuthRecord *rr; NetworkInterfaceInfo *intf = FirstInterfaceForID(m, InterfaceID); if (!intf) return; mDNS_Lock(m); // Pass 1: Process Neighbor Solicitations, and generate a Neighbor Advertisement if necessary. if (ndp->type == NDP_Sol) { //const mDNSEthAddr *const sha = GetLinkLayerAddressOption(ndp, end, NDP_SrcLL); (void)end; for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.InterfaceID == InterfaceID && rr->resrec.RecordType != kDNSRecordTypeDeregistering && rr->AddressProxy.type == mDNSAddrType_IPv6 && mDNSSameIPv6Address(rr->AddressProxy.ip.v6, ndp->target)) { static const char msg1[] = "NDP Req from owner -- re-probing"; static const char msg2[] = "Ignoring NDP Request from "; static const char msg3[] = "Creating Local NDP Cache entry "; static const char msg4[] = "Answering NDP Request from "; static const char msg5[] = "Answering NDP Probe from "; const char *const msg = mDNSSameEthAddress(sha, &rr->WakeUp.IMAC) ? msg1 : (rr->AnnounceCount == InitialAnnounceCount) ? msg2 : mDNSSameEthAddress(sha, &intf->MAC) ? msg3 : mDNSIPv6AddressIsZero(*spa) ? msg4 : msg5; LogSPS("%-7s %s %.6a %.16a for %.16a -- H-MAC %.6a I-MAC %.6a %s", intf->ifname, msg, sha, spa, &ndp->target, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); if (msg == msg1) { if (rr->ProbeRestartCount < MAX_PROBE_RESTARTS) RestartARPProbing(m, rr); else LogSPS("Reached maximum number of restarts for probing - %s", ARDisplayString(m,rr)); } else if (msg == msg3) mDNSPlatformSetLocalAddressCacheEntry(&rr->AddressProxy, &rr->WakeUp.IMAC, InterfaceID); else if (msg == msg4) SendNDP(m, NDP_Adv, NDP_Solicited, rr, &ndp->target, mDNSNULL, spa, sha); else if (msg == msg5) SendNDP(m, NDP_Adv, 0, rr, &ndp->target, mDNSNULL, &AllHosts_v6, &AllHosts_v6_Eth); } } // Pass 2: For all types of NDP packet we check the Sender IP address to make sure it doesn't conflict with any AddressProxy record we're holding. if (mDNSSameEthAddress(sha, &intf->MAC)) debugf("NDP from self for %.16a", &ndp->target); else { // For Neighbor Advertisements we check the Target address field, not the actual IPv6 source address. // When a machine has both link-local and routable IPv6 addresses, it may send NDP packets making assertions // about its routable IPv6 address, using its link-local address as the source address for all NDP packets. // Hence it is the NDP target address we care about, not the actual packet source address. if (ndp->type == NDP_Adv) spa = &ndp->target; if (!mDNSSameIPv6Address(*spa, zerov6Addr)) for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.InterfaceID == InterfaceID && rr->resrec.RecordType != kDNSRecordTypeDeregistering && rr->AddressProxy.type == mDNSAddrType_IPv6 && mDNSSameIPv6Address(rr->AddressProxy.ip.v6, *spa) && (rr->ProbeRestartCount < MAX_PROBE_RESTARTS)) { if (mDNSSameEthAddress(&zeroEthAddr, &rr->WakeUp.HMAC)) { LogSPS("%-7s NDP from %.6a %.16a for %.16a -- Invalid H-MAC %.6a I-MAC %.6a %s", intf->ifname, sha, spa, &ndp->target, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); } else { RestartARPProbing(m, rr); if (mDNSSameEthAddress(sha, &rr->WakeUp.IMAC)) { LogSPS("%-7s NDP %s from owner %.6a %.16a for %.16a -- re-starting probing for %s", intf->ifname, ndp->type == NDP_Sol ? "Solicitation " : "Advertisement", sha, spa, &ndp->target, ARDisplayString(m, rr)); } else { LogMsg("%-7s Conflicting NDP from %.6a %.16a for %.16a -- waking H-MAC %.6a I-MAC %.6a %s", intf->ifname, sha, spa, &ndp->target, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, rr)); ScheduleWakeup(m, rr->resrec.InterfaceID, &rr->WakeUp.HMAC); } } } } mDNS_Unlock(m); } mDNSlocal void mDNSCoreReceiveRawTransportPacket(mDNS *const m, const mDNSEthAddr *const sha, const mDNSAddr *const src, const mDNSAddr *const dst, const mDNSu8 protocol, const mDNSu8 *const p, const TransportLayerPacket *const t, const mDNSu8 *const end, const mDNSInterfaceID InterfaceID, const mDNSu16 len) { const mDNSIPPort port = (protocol == 0x06) ? t->tcp.dst : (protocol == 0x11) ? t->udp.dst : zeroIPPort; mDNSBool wake = mDNSfalse; mDNSBool kaWake = mDNSfalse; switch (protocol) { #define XX wake ? "Received" : "Ignoring", end-p case 0x01: LogSPS("Ignoring %d-byte ICMP from %#a to %#a", end-p, src, dst); break; case 0x06: { AuthRecord *kr; mDNSu32 seq, ack; #define TH_FIN 0x01 #define TH_SYN 0x02 #define TH_RST 0x04 #define TH_ACK 0x10 kr = mDNS_MatchKeepaliveInfo(m, dst, src, port, t->tcp.src, &seq, &ack); if (kr) { LogSPS("mDNSCoreReceiveRawTransportPacket: Found a Keepalive record from %#a:%d to %#a:%d", src, mDNSVal16(t->tcp.src), dst, mDNSVal16(port)); // Plan to wake if // (a) RST or FIN is set (the keepalive that we sent could have caused a reset) // (b) packet that contains new data and acks a sequence number higher than the one // we have been sending in the keepalive wake = ((t->tcp.flags & TH_RST) || (t->tcp.flags & TH_FIN)) ; if (!wake) { mDNSu8 *ptr; mDNSu32 pseq, pack; mDNSBool data = mDNSfalse; mDNSu8 tcphlen; // Convert to host order ptr = (mDNSu8 *)&seq; seq = ptr[0] << 24 | ptr[1] << 16 | ptr[2] << 8 | ptr[3]; ptr = (mDNSu8 *)&ack; ack = ptr[0] << 24 | ptr[1] << 16 | ptr[2] << 8 | ptr[3]; pseq = t->tcp.seq; ptr = (mDNSu8 *)&pseq; pseq = ptr[0] << 24 | ptr[1] << 16 | ptr[2] << 8 | ptr[3]; pack = t->tcp.ack; ptr = (mDNSu8 *)&pack; pack = ptr[0] << 24 | ptr[1] << 16 | ptr[2] << 8 | ptr[3]; // If the other side is acking one more than our sequence number (keepalive is one // less than the last valid sequence sent) and it's sequence is more than what we // acked before //if (end - p - 34 - ((t->tcp.offset >> 4) * 4) > 0) data = mDNStrue; tcphlen = ((t->tcp.offset >> 4) * 4); if (end - ((mDNSu8 *)t + tcphlen) > 0) data = mDNStrue; wake = ((int)(pack - seq) > 0) && ((int)(pseq - ack) >= 0) && data; // If we got a regular keepalive on a connection that was registed with the KeepAlive API, respond with an ACK if ((t->tcp.flags & TH_ACK) && (data == mDNSfalse) && ((int)(ack - pseq) == 1)) { // Send an ACK; mDNS_SendKeepaliveACK(m, kr); } LogSPS("mDNSCoreReceiveRawTransportPacket: End %p, hlen %d, Datalen %d, pack %u, seq %u, pseq %u, ack %u, wake %d", end, tcphlen, end - ((mDNSu8 *)t + tcphlen), pack, seq, pseq, ack, wake); } else { LogSPS("mDNSCoreReceiveRawTransportPacket: waking because of RST or FIN th_flags %d", t->tcp.flags); } kaWake = wake; } else { // Plan to wake if // (a) RST is not set, AND // (b) packet is SYN, SYN+FIN, or plain data packet (no SYN or FIN). We won't wake for FIN alone. wake = (!(t->tcp.flags & TH_RST) && (t->tcp.flags & (TH_FIN|TH_SYN)) != TH_FIN); // For now, to reduce spurious wakeups, we wake only for TCP SYN, // except for ssh connections, where we'll wake for plain data packets too if (!mDNSSameIPPort(port, SSHPort) && !(t->tcp.flags & 2)) wake = mDNSfalse; LogSPS("%s %d-byte TCP from %#a:%d to %#a:%d%s%s%s", XX, src, mDNSVal16(t->tcp.src), dst, mDNSVal16(port), (t->tcp.flags & 2) ? " SYN" : "", (t->tcp.flags & 1) ? " FIN" : "", (t->tcp.flags & 4) ? " RST" : ""); } break; } case 0x11: { #define ARD_AsNumber 3283 static const mDNSIPPort ARD = { { ARD_AsNumber >> 8, ARD_AsNumber & 0xFF } }; const mDNSu16 udplen = (mDNSu16)((mDNSu16)t->bytes[4] << 8 | t->bytes[5]); // Length *including* 8-byte UDP header if (udplen >= sizeof(UDPHeader)) { const mDNSu16 datalen = udplen - sizeof(UDPHeader); wake = mDNStrue; // For Back to My Mac UDP port 4500 (IPSEC) packets, we do some special handling if (mDNSSameIPPort(port, IPSECPort)) { // Specifically ignore NAT keepalive packets if (datalen == 1 && end >= &t->bytes[9] && t->bytes[8] == 0xFF) wake = mDNSfalse; else { // Skip over the Non-ESP Marker if present const mDNSBool NonESP = (end >= &t->bytes[12] && t->bytes[8] == 0 && t->bytes[9] == 0 && t->bytes[10] == 0 && t->bytes[11] == 0); const IKEHeader *const ike = (IKEHeader *)(t + (NonESP ? 12 : 8)); const mDNSu16 ikelen = datalen - (NonESP ? 4 : 0); if (ikelen >= sizeof(IKEHeader) && end >= ((mDNSu8 *)ike) + sizeof(IKEHeader)) if ((ike->Version & 0x10) == 0x10) { // ExchangeType == 5 means 'Informational' // ExchangeType == 34 means 'IKE_SA_INIT' if (ike->ExchangeType == 5 || ike->ExchangeType == 34) wake = mDNSfalse; LogSPS("%s %d-byte IKE ExchangeType %d", XX, ike->ExchangeType); } } } // For now, because we haven't yet worked out a clean elegant way to do this, we just special-case the // Apple Remote Desktop port number -- we ignore all packets to UDP 3283 (the "Net Assistant" port), // except for Apple Remote Desktop's explicit manual wakeup packet, which looks like this: // UDP header (8 bytes) // Payload: 13 88 00 6a 41 4e 41 20 (8 bytes) ffffffffffff (6 bytes) 16xMAC (96 bytes) = 110 bytes total if (mDNSSameIPPort(port, ARD)) wake = (datalen >= 110 && end >= &t->bytes[10] && t->bytes[8] == 0x13 && t->bytes[9] == 0x88); LogSPS("%s %d-byte UDP from %#a:%d to %#a:%d", XX, src, mDNSVal16(t->udp.src), dst, mDNSVal16(port)); } } break; case 0x3A: if (&t->bytes[len] <= end) { mDNSu16 checksum = IPv6CheckSum(&src->ip.v6, &dst->ip.v6, protocol, t->bytes, len); if (!checksum) mDNSCoreReceiveRawND(m, sha, &src->ip.v6, &t->ndp, &t->bytes[len], InterfaceID); else LogInfo("IPv6CheckSum bad %04X %02X%02X from %#a to %#a", checksum, t->bytes[2], t->bytes[3], src, dst); } break; default: LogSPS("Ignoring %d-byte IP packet unknown protocol %d from %#a to %#a", end-p, protocol, src, dst); break; } if (wake) { AuthRecord *rr, *r2; mDNS_Lock(m); for (rr = m->ResourceRecords; rr; rr=rr->next) if (rr->resrec.InterfaceID == InterfaceID && rr->resrec.RecordType != kDNSRecordTypeDeregistering && rr->AddressProxy.type && mDNSSameAddress(&rr->AddressProxy, dst)) { const mDNSu8 *const tp = (protocol == 6) ? (const mDNSu8 *)"\x4_tcp" : (const mDNSu8 *)"\x4_udp"; for (r2 = m->ResourceRecords; r2; r2=r2->next) if (r2->resrec.InterfaceID == InterfaceID && mDNSSameEthAddress(&r2->WakeUp.HMAC, &rr->WakeUp.HMAC) && r2->resrec.RecordType != kDNSRecordTypeDeregistering && r2->resrec.rrtype == kDNSType_SRV && mDNSSameIPPort(r2->resrec.rdata->u.srv.port, port) && SameDomainLabel(ThirdLabel(r2->resrec.name)->c, tp)) break; if (!r2 && mDNSSameIPPort(port, IPSECPort)) r2 = rr; // So that we wake for BTMM IPSEC packets, even without a matching SRV record if (!r2 && kaWake) r2 = rr; // So that we wake for keepalive packets, even without a matching SRV record if (r2) { LogMsg("Waking host at %s %#a H-MAC %.6a I-MAC %.6a for %s", InterfaceNameForID(m, rr->resrec.InterfaceID), dst, &rr->WakeUp.HMAC, &rr->WakeUp.IMAC, ARDisplayString(m, r2)); ScheduleWakeup(m, rr->resrec.InterfaceID, &rr->WakeUp.HMAC); } else LogSPS("Sleeping host at %s %#a %.6a has no service on %#s %d", InterfaceNameForID(m, rr->resrec.InterfaceID), dst, &rr->WakeUp.HMAC, tp, mDNSVal16(port)); } mDNS_Unlock(m); } } mDNSexport void mDNSCoreReceiveRawPacket(mDNS *const m, const mDNSu8 *const p, const mDNSu8 *const end, const mDNSInterfaceID InterfaceID) { static const mDNSOpaque16 Ethertype_ARP = { { 0x08, 0x06 } }; // Ethertype 0x0806 = ARP static const mDNSOpaque16 Ethertype_IPv4 = { { 0x08, 0x00 } }; // Ethertype 0x0800 = IPv4 static const mDNSOpaque16 Ethertype_IPv6 = { { 0x86, 0xDD } }; // Ethertype 0x86DD = IPv6 static const mDNSOpaque16 ARP_hrd_eth = { { 0x00, 0x01 } }; // Hardware address space (Ethernet = 1) static const mDNSOpaque16 ARP_pro_ip = { { 0x08, 0x00 } }; // Protocol address space (IP = 0x0800) // Note: BPF guarantees that the NETWORK LAYER header will be word aligned, not the link-layer header. // In other words, we can safely assume that pkt below (ARP, IPv4 or IPv6) is properly word aligned, // but if pkt is 4-byte aligned, that necessarily means that eth CANNOT also be 4-byte aligned // since it points to a an address 14 bytes before pkt. const EthernetHeader *const eth = (const EthernetHeader *)p; const NetworkLayerPacket *const pkt = (const NetworkLayerPacket *)(eth+1); mDNSAddr src, dst; #define RequiredCapLen(P) ((P)==0x01 ? 4 : (P)==0x06 ? 20 : (P)==0x11 ? 8 : (P)==0x3A ? 24 : 0) // Is ARP? Length must be at least 14 + 28 = 42 bytes if (end >= p+42 && mDNSSameOpaque16(eth->ethertype, Ethertype_ARP) && mDNSSameOpaque16(pkt->arp.hrd, ARP_hrd_eth) && mDNSSameOpaque16(pkt->arp.pro, ARP_pro_ip)) mDNSCoreReceiveRawARP(m, &pkt->arp, InterfaceID); // Is IPv4 with zero fragmentation offset? Length must be at least 14 + 20 = 34 bytes else if (end >= p+34 && mDNSSameOpaque16(eth->ethertype, Ethertype_IPv4) && (pkt->v4.flagsfrags.b[0] & 0x1F) == 0 && pkt->v4.flagsfrags.b[1] == 0) { const mDNSu8 *const trans = p + 14 + (pkt->v4.vlen & 0xF) * 4; const mDNSu8 * transEnd = p + 14 + mDNSVal16(pkt->v4.totlen); if (transEnd > end) transEnd = end; debugf("Got IPv4 %02X from %.4a to %.4a", pkt->v4.protocol, &pkt->v4.src.b, &pkt->v4.dst.b); src.type = mDNSAddrType_IPv4; src.ip.v4 = pkt->v4.src; dst.type = mDNSAddrType_IPv4; dst.ip.v4 = pkt->v4.dst; if (transEnd >= trans + RequiredCapLen(pkt->v4.protocol)) mDNSCoreReceiveRawTransportPacket(m, ð->src, &src, &dst, pkt->v4.protocol, p, (TransportLayerPacket*)trans, transEnd, InterfaceID, 0); } // Is IPv6? Length must be at least 14 + 28 = 42 bytes else if (end >= p+54 && mDNSSameOpaque16(eth->ethertype, Ethertype_IPv6)) { const mDNSu8 *const trans = p + 54; debugf("Got IPv6 %02X from %.16a to %.16a", pkt->v6.pro, &pkt->v6.src.b, &pkt->v6.dst.b); src.type = mDNSAddrType_IPv6; src.ip.v6 = pkt->v6.src; dst.type = mDNSAddrType_IPv6; dst.ip.v6 = pkt->v6.dst; if (end >= trans + RequiredCapLen(pkt->v6.pro)) mDNSCoreReceiveRawTransportPacket(m, ð->src, &src, &dst, pkt->v6.pro, p, (TransportLayerPacket*)trans, end, InterfaceID, (mDNSu16)pkt->bytes[4] << 8 | pkt->bytes[5]); } } mDNSlocal void ConstructSleepProxyServerName(mDNS *const m, domainlabel *name) { name->c[0] = (mDNSu8)mDNS_snprintf((char*)name->c+1, 62, "%d-%d-%d-%d.%d %#s", m->SPSType, m->SPSPortability, m->SPSMarginalPower, m->SPSTotalPower, m->SPSFeatureFlags, &m->nicelabel); } #ifndef SPC_DISABLED mDNSlocal void SleepProxyServerCallback(mDNS *const m, ServiceRecordSet *const srs, mStatus result) { if (result == mStatus_NameConflict) mDNS_RenameAndReregisterService(m, srs, mDNSNULL); else if (result == mStatus_MemFree) { if (m->SleepState) m->SPSState = 3; else { m->SPSState = (mDNSu8)(m->SPSSocket != mDNSNULL); if (m->SPSState) { domainlabel name; ConstructSleepProxyServerName(m, &name); mDNS_RegisterService(m, srs, &name, &SleepProxyServiceType, &localdomain, mDNSNULL, m->SPSSocket->port, // Host, port mDNSNULL, (mDNSu8 *)"", 1, // TXT data, length mDNSNULL, 0, // Subtypes (none) mDNSInterface_Any, // Interface ID SleepProxyServerCallback, mDNSNULL, 0); // Callback, context, flags } LogSPS("Sleep Proxy Server %#s %s", srs->RR_SRV.resrec.name->c, m->SPSState ? "started" : "stopped"); } } } #endif // Called with lock held mDNSexport void mDNSCoreBeSleepProxyServer_internal(mDNS *const m, mDNSu8 sps, mDNSu8 port, mDNSu8 marginalpower, mDNSu8 totpower, mDNSu8 features) { // This routine uses mDNS_DeregisterService and calls SleepProxyServerCallback, so we execute in user callback context mDNS_DropLockBeforeCallback(); // If turning off SPS, close our socket // (Do this first, BEFORE calling mDNS_DeregisterService below) if (!sps && m->SPSSocket) { mDNSPlatformUDPClose(m->SPSSocket); m->SPSSocket = mDNSNULL; } // If turning off, or changing type, deregister old name #ifndef SPC_DISABLED if (m->SPSState == 1 && sps != m->SPSType) { m->SPSState = 2; mDNS_DeregisterService_drt(m, &m->SPSRecords, sps ? mDNS_Dereg_rapid : mDNS_Dereg_normal); } #endif // SPC_DISABLED // Record our new SPS parameters m->SPSType = sps; m->SPSPortability = port; m->SPSMarginalPower = marginalpower; m->SPSTotalPower = totpower; m->SPSFeatureFlags = features; // If turning on, open socket and advertise service if (sps) { if (!m->SPSSocket) { m->SPSSocket = mDNSPlatformUDPSocket(zeroIPPort); if (!m->SPSSocket) { LogMsg("mDNSCoreBeSleepProxyServer: Failed to allocate SPSSocket"); goto fail; } } #ifndef SPC_DISABLED if (m->SPSState == 0) SleepProxyServerCallback(m, &m->SPSRecords, mStatus_MemFree); #endif // SPC_DISABLED } else if (m->SPSState) { LogSPS("mDNSCoreBeSleepProxyServer turning off from state %d; will wake clients", m->SPSState); m->NextScheduledSPS = m->timenow; } fail: mDNS_ReclaimLockAfterCallback(); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Startup and Shutdown #endif mDNSlocal void mDNS_GrowCache_internal(mDNS *const m, CacheEntity *storage, mDNSu32 numrecords) { if (storage && numrecords) { mDNSu32 i; debugf("Adding cache storage for %d more records (%d bytes)", numrecords, numrecords*sizeof(CacheEntity)); for (i=0; irrcache_free; m->rrcache_free = storage; m->rrcache_size += numrecords; } } mDNSexport void mDNS_GrowCache(mDNS *const m, CacheEntity *storage, mDNSu32 numrecords) { mDNS_Lock(m); mDNS_GrowCache_internal(m, storage, numrecords); mDNS_Unlock(m); } mDNSlocal mStatus mDNS_InitStorage(mDNS *const m, mDNS_PlatformSupport *const p, CacheEntity *rrcachestorage, mDNSu32 rrcachesize, mDNSBool AdvertiseLocalAddresses, mDNSCallback *Callback, void *Context) { mDNSu32 slot; mDNSs32 timenow; mStatus result; if (!rrcachestorage) rrcachesize = 0; m->p = p; m->NetworkChanged = 0; m->CanReceiveUnicastOn5353 = mDNSfalse; // Assume we can't receive unicasts on 5353, unless platform layer tells us otherwise m->AdvertiseLocalAddresses = AdvertiseLocalAddresses; m->DivertMulticastAdvertisements = mDNSfalse; m->mDNSPlatformStatus = mStatus_Waiting; m->UnicastPort4 = zeroIPPort; m->UnicastPort6 = zeroIPPort; m->PrimaryMAC = zeroEthAddr; m->MainCallback = Callback; m->MainContext = Context; m->rec.r.resrec.RecordType = 0; // For debugging: To catch and report locking failures m->mDNS_busy = 0; m->mDNS_reentrancy = 0; m->ShutdownTime = 0; m->lock_rrcache = 0; m->lock_Questions = 0; m->lock_Records = 0; // Task Scheduling variables result = mDNSPlatformTimeInit(); if (result != mStatus_NoError) return(result); m->timenow_adjust = (mDNSs32)mDNSRandom(0xFFFFFFFF); timenow = mDNS_TimeNow_NoLock(m); m->timenow = 0; // MUST only be set within mDNS_Lock/mDNS_Unlock section m->timenow_last = timenow; m->NextScheduledEvent = timenow; m->SuppressSending = timenow; m->NextCacheCheck = timenow + FutureTime; m->NextScheduledQuery = timenow + FutureTime; m->NextScheduledProbe = timenow + FutureTime; m->NextScheduledResponse = timenow + FutureTime; m->NextScheduledNATOp = timenow + FutureTime; m->NextScheduledSPS = timenow + FutureTime; m->NextScheduledKA = timenow + FutureTime; m->NextScheduledStopTime = timenow + FutureTime; m->NextBLEServiceTime = 0; // zero indicates inactive #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) m->NextBonjourDisableTime = 0; // Timer active when non zero. m->BonjourEnabled = 0; // Set when Bonjour on Demand is enabled and Bonjour is currently enabled. #endif m->RandomQueryDelay = 0; m->RandomReconfirmDelay = 0; m->PktNum = 0; m->MPktNum = 0; m->LocalRemoveEvents = mDNSfalse; m->SleepState = SleepState_Awake; m->SleepSeqNum = 0; m->SystemWakeOnLANEnabled = mDNSfalse; m->AnnounceOwner = NonZeroTime(timenow + 60 * mDNSPlatformOneSecond); m->DelaySleep = 0; m->SleepLimit = 0; #if APPLE_OSX_mDNSResponder m->UnicastPacketsSent = 0; m->MulticastPacketsSent = 0; m->RemoteSubnet = 0; #endif // APPLE_OSX_mDNSResponder // These fields only required for mDNS Searcher... m->Questions = mDNSNULL; m->NewQuestions = mDNSNULL; m->CurrentQuestion = mDNSNULL; m->LocalOnlyQuestions = mDNSNULL; m->NewLocalOnlyQuestions = mDNSNULL; m->RestartQuestion = mDNSNULL; m->rrcache_size = 0; m->rrcache_totalused = 0; m->rrcache_active = 0; m->rrcache_report = 10; m->rrcache_free = mDNSNULL; for (slot = 0; slot < CACHE_HASH_SLOTS; slot++) { m->rrcache_hash[slot] = mDNSNULL; m->rrcache_nextcheck[slot] = timenow + FutureTime;; } mDNS_GrowCache_internal(m, rrcachestorage, rrcachesize); m->rrauth.rrauth_free = mDNSNULL; for (slot = 0; slot < AUTH_HASH_SLOTS; slot++) m->rrauth.rrauth_hash[slot] = mDNSNULL; // Fields below only required for mDNS Responder... m->hostlabel.c[0] = 0; m->nicelabel.c[0] = 0; m->MulticastHostname.c[0] = 0; #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) m->RandomizedHostname.c[0] = 0; #endif m->HIHardware.c[0] = 0; m->HISoftware.c[0] = 0; m->ResourceRecords = mDNSNULL; m->DuplicateRecords = mDNSNULL; m->NewLocalRecords = mDNSNULL; m->NewLocalOnlyRecords = mDNSfalse; m->CurrentRecord = mDNSNULL; m->HostInterfaces = mDNSNULL; m->ProbeFailTime = 0; m->NumFailedProbes = 0; m->SuppressProbes = 0; #ifndef UNICAST_DISABLED m->NextuDNSEvent = timenow + FutureTime; m->NextSRVUpdate = timenow + FutureTime; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) m->DNSServers = mDNSNULL; #endif m->Router = zeroAddr; m->AdvertisedV4 = zeroAddr; m->AdvertisedV6 = zeroAddr; m->AuthInfoList = mDNSNULL; m->ReverseMap.ThisQInterval = -1; m->StaticHostname.c[0] = 0; m->FQDN.c[0] = 0; m->Hostnames = mDNSNULL; m->WABBrowseQueriesCount = 0; m->WABLBrowseQueriesCount = 0; m->WABRegQueriesCount = 0; m->AutoTargetServices = 1; #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) m->NumAllInterfaceRecords = 0; m->NumAllInterfaceQuestions = 0; #endif // NAT traversal fields m->LLQNAT.clientCallback = mDNSNULL; m->LLQNAT.clientContext = mDNSNULL; m->NATTraversals = mDNSNULL; m->CurrentNATTraversal = mDNSNULL; m->retryIntervalGetAddr = 0; // delta between time sent and retry m->retryGetAddr = timenow + FutureTime; // absolute time when we retry m->ExtAddress = zerov4Addr; m->PCPNonce[0] = mDNSRandom(-1); m->PCPNonce[1] = mDNSRandom(-1); m->PCPNonce[2] = mDNSRandom(-1); m->NATMcastRecvskt = mDNSNULL; m->LastNATupseconds = 0; m->LastNATReplyLocalTime = timenow; m->LastNATMapResultCode = NATErr_None; m->UPnPInterfaceID = 0; m->SSDPSocket = mDNSNULL; m->SSDPWANPPPConnection = mDNSfalse; m->UPnPRouterPort = zeroIPPort; m->UPnPSOAPPort = zeroIPPort; m->UPnPRouterURL = mDNSNULL; m->UPnPWANPPPConnection = mDNSfalse; m->UPnPSOAPURL = mDNSNULL; m->UPnPRouterAddressString = mDNSNULL; m->UPnPSOAPAddressString = mDNSNULL; m->SPSType = 0; m->SPSPortability = 0; m->SPSMarginalPower = 0; m->SPSTotalPower = 0; m->SPSFeatureFlags = 0; m->SPSState = 0; m->SPSProxyListChanged = mDNSNULL; m->SPSSocket = mDNSNULL; m->SPSBrowseCallback = mDNSNULL; m->ProxyRecords = 0; m->DNSPushServers = mDNSNULL; m->DNSPushZones = mDNSNULL; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) if (WCFConnectionNew) { m->WCF = WCFConnectionNew(); if (!m->WCF) { LogMsg("WCFConnectionNew failed"); return -1; } } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) result = init_and_load_trust_anchors(); if (result != mStatus_NoError) return(result); #endif return(result); } mDNSexport mStatus mDNS_Init(mDNS *const m, mDNS_PlatformSupport *const p, CacheEntity *rrcachestorage, mDNSu32 rrcachesize, mDNSBool AdvertiseLocalAddresses, mDNSCallback *Callback, void *Context) { mStatus result = mDNS_InitStorage(m, p, rrcachestorage, rrcachesize, AdvertiseLocalAddresses, Callback, Context); if (result != mStatus_NoError) return(result); #if MDNS_MALLOC_DEBUGGING static mDNSListValidator lv; mDNSPlatformAddListValidator(&lv, mDNS_ValidateLists, "mDNS_ValidateLists", m); #endif result = mDNSPlatformInit(m); #ifndef UNICAST_DISABLED // It's better to do this *after* the platform layer has set up the // interface list and security credentials uDNS_SetupDNSConfig(m); // Get initial DNS configuration #endif return(result); } mDNSexport void mDNS_ConfigChanged(mDNS *const m) { if (m->SPSState == 1) { domainlabel name, newname; #ifndef SPC_DISABLED domainname type, domain; DeconstructServiceName(m->SPSRecords.RR_SRV.resrec.name, &name, &type, &domain); #endif // SPC_DISABLED ConstructSleepProxyServerName(m, &newname); if (!SameDomainLabelCS(name.c, newname.c)) { LogSPS("Renaming SPS from “%#s” to “%#s”", name.c, newname.c); // When SleepProxyServerCallback gets the mStatus_MemFree message, // it will reregister the service under the new name m->SPSState = 2; #ifndef SPC_DISABLED mDNS_DeregisterService_drt(m, &m->SPSRecords, mDNS_Dereg_rapid); #endif // SPC_DISABLED } } if (m->MainCallback) m->MainCallback(m, mStatus_ConfigChanged); } mDNSlocal void DynDNSHostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { (void)m; // unused debugf("NameStatusCallback: result %d for registration of name %##s", result, rr->resrec.name->c); mDNSPlatformDynDNSHostNameStatusChanged(rr->resrec.name, result); } #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSlocal void PurgeOrReconfirmCacheRecord(mDNS *const m, CacheRecord *cr) { mDNSBool purge = cr->resrec.RecordType == kDNSRecordTypePacketNegative || cr->resrec.rrtype == kDNSType_A || cr->resrec.rrtype == kDNSType_AAAA || cr->resrec.rrtype == kDNSType_SRV || cr->resrec.rrtype == kDNSType_CNAME; debugf("PurgeOrReconfirmCacheRecord: %s cache record due to server %#a:%d (%##s): %s", purge ? "purging" : "reconfirming", cr->resrec.rDNSServer ? &cr->resrec.rDNSServer->addr : mDNSNULL, cr->resrec.rDNSServer ? mDNSVal16(cr->resrec.rDNSServer->port) : -1, cr->resrec.rDNSServer ? cr->resrec.rDNSServer->domain.c : mDNSNULL, CRDisplayString(m, cr)); if (purge) { LogInfo("PurgeorReconfirmCacheRecord: Purging Resourcerecord %s, RecordType %x", CRDisplayString(m, cr), cr->resrec.RecordType); mDNS_PurgeCacheResourceRecord(m, cr); } else { LogInfo("PurgeorReconfirmCacheRecord: Reconfirming Resourcerecord %s, RecordType %x", CRDisplayString(m, cr), cr->resrec.RecordType); mDNS_Reconfirm_internal(m, cr, kDefaultReconfirmTimeForNoAnswer); } } #endif mDNSlocal void mDNS_PurgeBeforeResolve(mDNS *const m, DNSQuestion *q) { CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); CacheRecord *rp; for (rp = cg ? cg->members : mDNSNULL; rp; rp = rp->next) { if (SameNameCacheRecordAnswersQuestion(rp, q)) { LogInfo("mDNS_PurgeBeforeResolve: Flushing %s", CRDisplayString(m, rp)); mDNS_PurgeCacheResourceRecord(m, rp); } } } #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSexport void DNSServerChangeForQuestion(mDNS *const m, DNSQuestion *q, DNSServer *new) { DNSQuestion *qptr; (void) m; if (q->DuplicateOf) LogMsg("DNSServerChangeForQuestion: ERROR: Called for duplicate question %##s", q->qname.c); // Make sure all the duplicate questions point to the same DNSServer so that delivery // of events for all of them are consistent. Duplicates for a question are always inserted // after in the list. q->qDNSServer = new; for (qptr = q->next ; qptr; qptr = qptr->next) { if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = new; } } } #endif mDNSlocal void SetConfigState(mDNS *const m, mDNSBool delete) { McastResolver *mr; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) DNSServer *ptr; #endif if (delete) { #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) for (ptr = m->DNSServers; ptr; ptr = ptr->next) { ptr->penaltyTime = 0; ptr->flags |= DNSServerFlag_Delete; #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) if (ptr->flags & DNSServerFlag_Unreachable) NumUnreachableDNSServers--; #endif } #endif // We handle the mcast resolvers here itself as mDNSPlatformSetDNSConfig looks at // mcast resolvers. Today we get both mcast and ucast configuration using the same // API for (mr = m->McastResolvers; mr; mr = mr->next) mr->flags |= McastResolver_FlagDelete; } else { #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) for (ptr = m->DNSServers; ptr; ptr = ptr->next) { ptr->penaltyTime = 0; ptr->flags &= ~DNSServerFlag_Delete; #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) if (ptr->flags & DNSServerFlag_Unreachable) NumUnreachableDNSServers++; #endif } #endif for (mr = m->McastResolvers; mr; mr = mr->next) mr->flags &= ~McastResolver_FlagDelete; } } mDNSlocal void SetDynDNSHostNameIfChanged(mDNS *const m, domainname *const fqdn) { // Did our FQDN change? if (!SameDomainName(fqdn, &m->FQDN)) { if (m->FQDN.c[0]) mDNS_RemoveDynDNSHostName(m, &m->FQDN); AssignDomainName(&m->FQDN, fqdn); if (m->FQDN.c[0]) { mDNSPlatformDynDNSHostNameStatusChanged(&m->FQDN, 1); mDNS_AddDynDNSHostName(m, &m->FQDN, DynDNSHostNameCallback, mDNSNULL); } } } // Even though this is called “Setup” it is not called just once at startup. // It’s actually called multiple times, every time there’s a configuration change. mDNSexport mStatus uDNS_SetupDNSConfig(mDNS *const m) { #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSu32 slot; CacheGroup *cg; CacheRecord *cr; #endif mDNSAddr v4, v6, r; domainname fqdn; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) DNSServer *ptr, **p = &m->DNSServers; const DNSServer *oldServers = m->DNSServers; DNSQuestion *q; #endif McastResolver *mr, **mres = &m->McastResolvers; #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) && !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) DNSPushNotificationServer **psp; #endif debugf("uDNS_SetupDNSConfig: entry"); // Let the platform layer get the current DNS information and setup the WAB queries if needed. uDNS_SetupWABQueries(m); mDNS_Lock(m); // We need to first mark all the entries to be deleted. If the configuration changed, then // the entries would be undeleted appropriately. Otherwise, we need to clear them. // // Note: The last argument to mDNSPlatformSetDNSConfig is "mDNStrue" which means ack the // configuration. We already processed search domains in uDNS_SetupWABQueries above and // hence we are ready to ack the configuration as this is the last call to mDNSPlatformSetConfig // for the dns configuration change notification. SetConfigState(m, mDNStrue); if (!mDNSPlatformSetDNSConfig(mDNStrue, mDNSfalse, &fqdn, mDNSNULL, mDNSNULL, mDNStrue)) { SetDynDNSHostNameIfChanged(m, &fqdn); SetConfigState(m, mDNSfalse); mDNS_Unlock(m); LogInfo("uDNS_SetupDNSConfig: No configuration change"); return mStatus_NoError; } // For now, we just delete the mcast resolvers. We don't deal with cache or // questions here. Neither question nor cache point to mcast resolvers. Questions // do inherit the timeout values from mcast resolvers. But we don't bother // affecting them as they never change. while (*mres) { if (((*mres)->flags & McastResolver_FlagDelete) != 0) { mr = *mres; *mres = (*mres)->next; debugf("uDNS_SetupDNSConfig: Deleting mcast resolver %##s", mr, mr->domain.c); mDNSPlatformMemFree(mr); } else { (*mres)->flags &= ~McastResolver_FlagNew; mres = &(*mres)->next; } } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) Querier_ProcessDNSServiceChanges(); #else // Update our qDNSServer pointers before we go and free the DNSServer object memory // // All non-scoped resolvers share the same resGroupID. At no point in time a cache entry using DNSServer // from scoped resolver will be used to answer non-scoped questions and vice versa, as scoped and non-scoped // resolvers don't share the same resGroupID. A few examples to describe the interaction with how we pick // DNSServers and flush the cache. // // - A non-scoped question picks DNSServer X, creates a cache entry with X. If a new resolver gets added later that // is a better match, we pick the new DNSServer for the question and activate the unicast query. We may or may not // flush the cache (See PurgeOrReconfirmCacheRecord). In either case, we don't change the cache record's DNSServer // pointer immediately (qDNSServer and rDNSServer may be different but still share the same resGroupID). If we don't // flush the cache immediately, the record's rDNSServer pointer will be updated (in mDNSCoreReceiveResponse) // later when we get the response. If we purge the cache, we still deliver a RMV when it is purged even though // we don't update the cache record's DNSServer pointer to match the question's DNSSever, as they both point to // the same resGroupID. // // Note: If the new DNSServer comes back with a different response than what we have in the cache, we will deliver a RMV // of the old followed by ADD of the new records. // // - A non-scoped question picks DNSServer X, creates a cache entry with X. If the resolver gets removed later, we will // pick a new DNSServer for the question which may or may not be NULL and set the cache record's pointer to the same // as in question's qDNSServer if the cache record is not flushed. If there is no active question, it will be set to NULL. // // - Two questions scoped and non-scoped for the same name will pick two different DNSServer and will end up creating separate // cache records and as the resGroupID is different, you can't use the cache record from the scoped DNSServer to answer the // non-scoped question and vice versa. // #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) DNS64RestartQuestions(m); #endif // First, restart questions whose suppression status will change. The suppression status of each question in a given // question set, i.e., a non-duplicate question and all of its duplicates, if any, may or may not change. For example, // a suppressed (or non-suppressed) question that is currently a duplicate of a suppressed (or non-suppressed) question // may become a non-suppressed (or suppressed) question, while the question that it's a duplicate of may remain // suppressed (or non-suppressed). for (q = m->Questions; q; q = q->next) { DNSServer *s; const DNSServer *t; mDNSBool oldSuppressed; if (mDNSOpaque16IsZero(q->TargetQID)) continue; SetValidDNSServers(m, q); q->triedAllServersOnce = mDNSfalse; s = GetServerForQuestion(m, q); t = q->qDNSServer; if (s != t) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_SetupDNSConfig: Updating DNS server from " PRI_IP_ADDR ":%d (" PRI_DM_NAME ") to " PRI_IP_ADDR ":%d (" PRI_DM_NAME ") for question " PRI_DM_NAME " (" PUB_S ") (scope:%p)", q->request_id, mDNSVal16(q->TargetQID), t ? &t->addr : mDNSNULL, mDNSVal16(t ? t->port : zeroIPPort), DM_NAME_PARAM(t ? &t->domain : mDNSNULL), s ? &s->addr : mDNSNULL, mDNSVal16(s ? s->port : zeroIPPort), DM_NAME_PARAM(s ? &s->domain : mDNSNULL), DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), q->InterfaceID); #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) // If this question had a DNS Push server associated with it, substitute the new server for the // old one. If there is no new server, then we'll clean up the push server later. if (!q->DuplicateOf && (q->dnsPushServer != mDNSNULL)) { if (q->dnsPushServer->qDNSServer == t) { q->dnsPushServer->qDNSServer = s; // which might be null } // If it is null, do the accounting and drop the push server. if (q->dnsPushServer->qDNSServer == mDNSNULL) { DNSPushReconcileConnection(m, q); } } #endif } oldSuppressed = q->Suppressed; q->Suppressed = ShouldSuppressUnicastQuery(q, s); if (!q->Suppressed != !oldSuppressed) q->Restart = mDNStrue; } RestartUnicastQuestions(m); // Now, change the server for each question set, if necessary. Note that questions whose suppression status changed // have already had their server changed by being restarted. for (q = m->Questions; q; q = q->next) { DNSServer *s; const DNSServer *t; if (mDNSOpaque16IsZero(q->TargetQID) || q->DuplicateOf) continue; SetValidDNSServers(m, q); q->triedAllServersOnce = mDNSfalse; s = GetServerForQuestion(m, q); t = q->qDNSServer; DNSServerChangeForQuestion(m, q, s); if (s == t) continue; q->Suppressed = ShouldSuppressUnicastQuery(q, s); q->unansweredQueries = 0; q->TargetQID = mDNS_NewMessageID(m); if (!q->Suppressed) ActivateUnicastQuery(m, q, mDNStrue); } #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) // The above code may have found some DNS Push servers that are no longer valid. Now that we // are done running through the code, we need to drop our connections to those servers. // When we get here, any such servers should have zero questions associated with them. for (psp = &m->DNSPushServers; *psp != mDNSNULL; ) { DNSPushNotificationServer *server = *psp; // It's possible that a push server whose DNS server has been deleted could be still connected but // not referenced by any questions. In this case, we just delete the push server rather than trying // to figure out with which DNS server (if any) to associate it. if (server->qDNSServer != mDNSNULL && server->qDNSServer->flags & DNSServerFlag_Delete) { server->qDNSServer = mDNSNULL; } if (server->qDNSServer == mDNSNULL) { // This would be a programming error, so should never happen. if (server->numberOfQuestions != 0) { LogInfo("uDNS_SetupDNSConfig: deleting push server %##s that has questions.", &server->serverName); } DNSPushServerDrop(server); *psp = server->next; mDNSPlatformMemFree(server); } else { psp = &(*psp)->next; } } #endif FORALL_CACHERECORDS(slot, cg, cr) { if (cr->resrec.InterfaceID) continue; // We already walked the questions and restarted/reactivated them if the dns server // change affected the question. That should take care of updating the cache. But // what if there is no active question at this point when the DNS server change // happened ? There could be old cache entries lying around and if we don't flush // them, a new question after the DNS server change could pick up these stale // entries and get a wrong answer. // // For cache entries that have active questions we might have skipped rescheduling // the questions if they were suppressed (see above). To keep it simple, we walk // all the cache entries to make sure that there are no stale entries. We use the // active question's InterfaceID/ServiceID for looking up the right DNS server. // // Note: If GetServerForName returns NULL, it could either mean that there are no // DNS servers or no matching DNS servers for this question. In either case, // the cache should get purged below when we process deleted DNS servers. if (cr->CRActiveQuestion) { // Purge or Reconfirm if this cache entry would use the new DNS server ptr = GetServerForName(m, cr->resrec.name, cr->CRActiveQuestion->InterfaceID, cr->CRActiveQuestion->ServiceID); if (ptr && (ptr != cr->resrec.rDNSServer)) { LogInfo("uDNS_SetupDNSConfig: Purging/Reconfirming Resourcerecord %s, New DNS server %#a, Old DNS server %#a", CRDisplayString(m, cr), &ptr->addr, cr->resrec.rDNSServer ? &cr->resrec.rDNSServer->addr : mDNSNULL); PurgeOrReconfirmCacheRecord(m, cr); // If a cache record's DNSServer pointer is NULL, but its active question got a DNSServer in this DNS configuration // update, then use its DNSServer. This way, the active question and its duplicates don't miss out on RMV events. if (!cr->resrec.rDNSServer && cr->CRActiveQuestion->qDNSServer) { LogInfo("uDNS_SetupDNSConfig: Using active question's DNS server %#a for cache record %s", &cr->CRActiveQuestion->qDNSServer->addr, CRDisplayString(m, cr)); cr->resrec.rDNSServer = cr->CRActiveQuestion->qDNSServer; } } if (cr->resrec.rDNSServer && cr->resrec.rDNSServer->flags & DNSServerFlag_Delete) { DNSQuestion *qptr = cr->CRActiveQuestion; if (qptr->qDNSServer == cr->resrec.rDNSServer) { LogMsg("uDNS_SetupDNSConfig: ERROR!! Cache Record %s Active question %##s (%s) (scope:%p) pointing to DNSServer Address %#a" " to be freed", CRDisplayString(m, cr), qptr->qname.c, DNSTypeName(qptr->qtype), qptr->InterfaceID, &cr->resrec.rDNSServer->addr); qptr->validDNSServers = zeroOpaque128; qptr->qDNSServer = mDNSNULL; cr->resrec.rDNSServer = mDNSNULL; } else { LogInfo("uDNS_SetupDNSConfig: Cache Record %s, Active question %##s (%s) (scope:%p), pointing to DNSServer %#a (to be deleted)," " resetting to question's DNSServer Address %#a", CRDisplayString(m, cr), qptr->qname.c, DNSTypeName(qptr->qtype), qptr->InterfaceID, &cr->resrec.rDNSServer->addr, qptr->qDNSServer ? &qptr->qDNSServer->addr : mDNSNULL); cr->resrec.rDNSServer = qptr->qDNSServer; } PurgeOrReconfirmCacheRecord(m, cr); } } else if (!cr->resrec.rDNSServer || cr->resrec.rDNSServer->flags & DNSServerFlag_Delete) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "uDNS_SetupDNSConfig: Purging Resourcerecord " PRI_S ", DNS server " PUB_S " " PRI_IP_ADDR " " PUB_S, CRDisplayString(m, cr), !cr->resrec.rDNSServer ? "(to be deleted)" : "", cr->resrec.rDNSServer ? &cr->resrec.rDNSServer->addr : mDNSNULL, cr->resrec.rDNSServer ? DNSScopeToString(cr->resrec.rDNSServer->scopeType) : "" ); cr->resrec.rDNSServer = mDNSNULL; mDNS_PurgeCacheResourceRecord(m, cr); } } // Delete all the DNS servers that are flagged for deletion while (*p) { if (((*p)->flags & DNSServerFlag_Delete) != 0) { ptr = *p; *p = (*p)->next; LogInfo("uDNS_SetupDNSConfig: Deleting server %p %#a:%d (%##s)", ptr, &ptr->addr, mDNSVal16(ptr->port), ptr->domain.c); mDNSPlatformMemFree(ptr); } else { p = &(*p)->next; } } LogInfo("uDNS_SetupDNSConfig: CountOfUnicastDNSServers %d", CountOfUnicastDNSServers(m)); // If we now have no DNS servers at all and we used to have some, then immediately purge all unicast cache records (including for LLQs). // This is important for giving prompt remove events when the user disconnects the Ethernet cable or turns off wireless. // Otherwise, stale data lingers for 5-10 seconds, which is not the user-experience people expect from Bonjour. // Similarly, if we now have some DNS servers and we used to have none, we want to purge any fake negative results we may have generated. if ((m->DNSServers != mDNSNULL) != (oldServers != mDNSNULL)) { int count = 0; FORALL_CACHERECORDS(slot, cg, cr) { if (!cr->resrec.InterfaceID) { mDNS_PurgeCacheResourceRecord(m, cr); count++; } } LogInfo("uDNS_SetupDNSConfig: %s available; purged %d unicast DNS records from cache", m->DNSServers ? "DNS server became" : "No DNS servers", count); // Force anything that needs to get zone data to get that information again RestartRecordGetZoneData(m); } #endif // !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) SetDynDNSHostNameIfChanged(m, &fqdn); mDNS_Unlock(m); // handle router and primary interface changes v4 = v6 = r = zeroAddr; v4.type = r.type = mDNSAddrType_IPv4; if (mDNSPlatformGetPrimaryInterface(&v4, &v6, &r) == mStatus_NoError && !mDNSv4AddressIsLinkLocal(&v4.ip.v4)) { mDNS_SetPrimaryInterfaceInfo(m, !mDNSIPv4AddressIsZero(v4.ip.v4) ? &v4 : mDNSNULL, !mDNSIPv6AddressIsZero(v6.ip.v6) ? &v6 : mDNSNULL, !mDNSIPv4AddressIsZero(r.ip.v4) ? &r : mDNSNULL); } else { mDNS_SetPrimaryInterfaceInfo(m, mDNSNULL, mDNSNULL, mDNSNULL); if (m->FQDN.c[0]) mDNSPlatformDynDNSHostNameStatusChanged(&m->FQDN, 1); // Set status to 1 to indicate temporary failure } debugf("uDNS_SetupDNSConfig: number of unicast DNS servers %d", CountOfUnicastDNSServers(m)); return mStatus_NoError; } mDNSexport void mDNSCoreInitComplete(mDNS *const m, mStatus result) { m->mDNSPlatformStatus = result; if (m->MainCallback) { mDNS_Lock(m); mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback m->MainCallback(m, mStatus_NoError); mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again mDNS_Unlock(m); } } mDNSlocal void DeregLoop(mDNS *const m, AuthRecord *const start) { m->CurrentRecord = start; while (m->CurrentRecord) { AuthRecord *rr = m->CurrentRecord; LogInfo("DeregLoop: %s deregistration for %p %02X %s", (rr->resrec.RecordType != kDNSRecordTypeDeregistering) ? "Initiating " : "Accelerating", rr, rr->resrec.RecordType, ARDisplayString(m, rr)); if (rr->resrec.RecordType != kDNSRecordTypeDeregistering) mDNS_Deregister_internal(m, rr, mDNS_Dereg_rapid); else if (rr->AnnounceCount > 1) { rr->AnnounceCount = 1; rr->LastAPTime = m->timenow - rr->ThisAPInterval; } // Mustn't advance m->CurrentRecord until *after* mDNS_Deregister_internal, because // new records could have been added to the end of the list as a result of that call. if (m->CurrentRecord == rr) // If m->CurrentRecord was not advanced for us, do it now m->CurrentRecord = rr->next; } } mDNSexport void mDNS_StartExit(mDNS *const m) { AuthRecord *rr; mDNS_Lock(m); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit"); m->ShutdownTime = NonZeroTime(m->timenow + mDNSPlatformOneSecond * 5); mDNSCoreBeSleepProxyServer_internal(m, 0, 0, 0, 0, 0); #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) if (WCFConnectionDealloc) { if (m->WCF) { WCFConnectionDealloc(m->WCF); m->WCF = mDNSNULL; } } #endif #ifndef UNICAST_DISABLED { SearchListElem *s; SuspendLLQs(m); // Don't need to do SleepRecordRegistrations() here // because we deregister all records and services later in this routine while (m->Hostnames) mDNS_RemoveDynDNSHostName(m, &m->Hostnames->fqdn); // For each member of our SearchList, deregister any records it may have created, and cut them from the list. // Otherwise they'll be forcibly deregistered for us (without being cut them from the appropriate list) // and we may crash because the list still contains dangling pointers. for (s = SearchList; s; s = s->next) while (s->AuthRecs) { ARListElem *dereg = s->AuthRecs; s->AuthRecs = s->AuthRecs->next; mDNS_Deregister_internal(m, &dereg->ar, mDNS_Dereg_normal); // Memory will be freed in the FreeARElemCallback } } #endif DeadvertiseAllInterfaceRecords(m, kDeadvertiseFlag_All); // Shut down all our active NAT Traversals while (m->NATTraversals) { NATTraversalInfo *t = m->NATTraversals; mDNS_StopNATOperation_internal(m, t); // This will cut 't' from the list, thereby advancing m->NATTraversals in the process // After stopping the NAT Traversal, we zero out the fields. // This has particularly important implications for our AutoTunnel records -- // when we deregister our AutoTunnel records below, we don't want their mStatus_MemFree // handlers to just turn around and attempt to re-register those same records. // Clearing t->ExternalPort/t->RequestedPort will cause the mStatus_MemFree callback handlers // to not do this. t->ExternalAddress = zerov4Addr; t->NewAddress = zerov4Addr; t->ExternalPort = zeroIPPort; t->RequestedPort = zeroIPPort; t->Lifetime = 0; t->Result = mStatus_NoError; } // Make sure there are nothing but deregistering records remaining in the list if (m->CurrentRecord) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: ERROR m->CurrentRecord already set " PRI_S, ARDisplayString(m, m->CurrentRecord)); } // We're in the process of shutting down, so queries, etc. are no longer available. // Consequently, determining certain information, e.g. the uDNS update server's IP // address, will not be possible. The records on the main list are more likely to // already contain such information, so we deregister the duplicate records first. LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: Deregistering duplicate resource records"); DeregLoop(m, m->DuplicateRecords); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: Deregistering resource records"); DeregLoop(m, m->ResourceRecords); // If we scheduled a response to send goodbye packets, we set NextScheduledResponse to now. Normally when deregistering records, // we allow up to 100ms delay (to help improve record grouping) but when shutting down we don't want any such delay. if (m->NextScheduledResponse - m->timenow < mDNSPlatformOneSecond) { m->NextScheduledResponse = m->timenow; m->SuppressSending = 0; } if (m->ResourceRecords) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: Sending final record deregistrations"); } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: No deregistering records remain"); } for (rr = m->DuplicateRecords; rr; rr = rr->next) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: Should not still have Duplicate Records remaining: %02X " PRI_S, rr->resrec.RecordType, ARDisplayString(m, rr)); } // If any deregistering records remain, send their deregistration announcements before we exit if (m->mDNSPlatformStatus != mStatus_NoError) DiscardDeregistrations(m); mDNS_Unlock(m); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_StartExit: done"); } mDNSexport void mDNS_FinalExit(mDNS *const m) { mDNSu32 rrcache_active = 0; mDNSu32 rrcache_totalused = m->rrcache_totalused; mDNSu32 slot; AuthRecord *rr; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_FinalExit: mDNSPlatformClose"); mDNSPlatformClose(m); for (slot = 0; slot < CACHE_HASH_SLOTS; slot++) { while (m->rrcache_hash[slot]) { CacheGroup *cg = m->rrcache_hash[slot]; while (cg->members) { CacheRecord *cr = cg->members; cg->members = cg->members->next; if (cr->CRActiveQuestion) rrcache_active++; ReleaseCacheRecord(m, cr); } cg->rrcache_tail = &cg->members; ReleaseCacheGroup(m, &m->rrcache_hash[slot]); } } debugf("mDNS_FinalExit: RR Cache was using %ld records, %lu active", rrcache_totalused, rrcache_active); if (rrcache_active != m->rrcache_active) LogMsg("*** ERROR *** rrcache_totalused %lu; rrcache_active %lu != m->rrcache_active %lu", rrcache_totalused, rrcache_active, m->rrcache_active); for (rr = m->ResourceRecords; rr; rr = rr->next) LogMsg("mDNS_FinalExit failed to send goodbye for: %p %02X %s", rr, rr->resrec.RecordType, ARDisplayString(m, rr)); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) uninit_trust_anchors(); #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "mDNS_FinalExit: done"); } #ifdef UNIT_TEST #include "../unittests/mdns_ut.c" #endif /* * Copyright (c) 2002-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __mDNSDebug_h #define __mDNSDebug_h #include "mDNSFeatures.h" #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #include #endif // Set MDNS_DEBUGMSGS to 0 to optimize debugf() calls out of the compiled code // Set MDNS_DEBUGMSGS to 1 to generate normal debugging messages // Set MDNS_DEBUGMSGS to 2 to generate verbose debugging messages // MDNS_DEBUGMSGS is normally set in the project options (or makefile) but can also be set here if desired // (If you edit the file here to turn on MDNS_DEBUGMSGS while you're debugging some code, be careful // not to accidentally check-in that change by mistake when you check in your other changes.) //#undef MDNS_DEBUGMSGS //#define MDNS_DEBUGMSGS 2 // Set MDNS_CHECK_PRINTF_STYLE_FUNCTIONS to 1 to enable extra GCC compiler warnings // Note: You don't normally want to do this, because it generates a bunch of // spurious warnings for the following custom extensions implemented by mDNS_vsnprintf: // warning: `#' flag used with `%s' printf format (for %#s -- pascal string format) // warning: repeated `#' flag in format (for %##s -- DNS name string format) // warning: double format, pointer arg (arg 2) (for %.4a, %.16a, %#a -- IP address formats) #define MDNS_CHECK_PRINTF_STYLE_FUNCTIONS 0 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) typedef os_log_t mDNSLogCategory_t; typedef os_log_type_t mDNSLogLevel_t; #define MDNS_LOG_FAULT OS_LOG_TYPE_FAULT #define MDNS_LOG_ERROR OS_LOG_TYPE_ERROR #define MDNS_LOG_WARNING OS_LOG_TYPE_DEFAULT #define MDNS_LOG_DEFAULT OS_LOG_TYPE_DEFAULT #define MDNS_LOG_INFO OS_LOG_TYPE_DEFAULT #define MDNS_LOG_DEBUG OS_LOG_TYPE_DEBUG #else typedef const char * mDNSLogCategory_t; typedef enum { MDNS_LOG_FAULT = 1, MDNS_LOG_ERROR = 2, MDNS_LOG_WARNING = 3, MDNS_LOG_DEFAULT = 4, MDNS_LOG_INFO = 5, MDNS_LOG_DEBUG = 6 } mDNSLogLevel_t; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) extern os_log_t mDNSLogCategory_Default; extern os_log_t mDNSLogCategory_mDNS; extern os_log_t mDNSLogCategory_uDNS; extern os_log_t mDNSLogCategory_SPS; extern os_log_t mDNSLogCategory_XPC; extern os_log_t mDNSLogCategory_Analytics; extern os_log_t mDNSLogCategory_DNSSEC; #define MDNS_LOG_CATEGORY_DEFINITION(NAME) mDNSLogCategory_ ## NAME #else #define MDNS_LOG_CATEGORY_DEFINITION(NAME) # NAME #endif #define MDNS_LOG_CATEGORY_DEFAULT MDNS_LOG_CATEGORY_DEFINITION(Default) #define MDNS_LOG_CATEGORY_MDNS MDNS_LOG_CATEGORY_DEFINITION(mDNS) #define MDNS_LOG_CATEGORY_UDNS MDNS_LOG_CATEGORY_DEFINITION(uDNS) #define MDNS_LOG_CATEGORY_SPS MDNS_LOG_CATEGORY_DEFINITION(SPS) #define MDNS_LOG_CATEGORY_XPC MDNS_LOG_CATEGORY_DEFINITION(XPC) #define MDNS_LOG_CATEGORY_ANALYTICS MDNS_LOG_CATEGORY_DEFINITION(Analytics) #define MDNS_LOG_CATEGORY_DNSSEC MDNS_LOG_CATEGORY_DEFINITION(DNSSEC) // Set this symbol to 1 to answer remote queries for our Address, and reverse mapping PTR #define ANSWER_REMOTE_HOSTNAME_QUERIES 0 // Set this symbol to 1 to do extra debug checks on malloc() and free() // Set this symbol to 2 to write a log message for every malloc() and free() // #define MDNS_MALLOC_DEBUGGING 1 #if (MDNS_MALLOC_DEBUGGING > 0) && defined(WIN32) #error "Malloc debugging does not yet work on Windows" #endif //#define ForceAlerts 1 //#define LogTimeStamps 1 // Developer-settings section ends here #if MDNS_CHECK_PRINTF_STYLE_FUNCTIONS #define IS_A_PRINTF_STYLE_FUNCTION(F,A) __attribute__ ((format(printf,F,A))) #else #define IS_A_PRINTF_STYLE_FUNCTION(F,A) #endif #ifdef __cplusplus extern "C" { #endif // Variable argument macro support. Use ANSI C99 __VA_ARGS__ where possible. Otherwise, use the next best thing. #if (defined(__GNUC__)) #if ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 2))) #define MDNS_C99_VA_ARGS 1 #define MDNS_GNU_VA_ARGS 0 #else #define MDNS_C99_VA_ARGS 0 #define MDNS_GNU_VA_ARGS 1 #endif #define MDNS_HAS_VA_ARG_MACROS 1 #elif (_MSC_VER >= 1400) // Visual Studio 2005 and later #define MDNS_C99_VA_ARGS 1 #define MDNS_GNU_VA_ARGS 0 #define MDNS_HAS_VA_ARG_MACROS 1 #elif (defined(__MWERKS__)) #define MDNS_C99_VA_ARGS 1 #define MDNS_GNU_VA_ARGS 0 #define MDNS_HAS_VA_ARG_MACROS 1 #else #define MDNS_C99_VA_ARGS 1 #define MDNS_GNU_VA_ARGS 0 #define MDNS_HAS_VA_ARG_MACROS 1 #endif #if (MDNS_HAS_VA_ARG_MACROS) #if (MDNS_C99_VA_ARGS) #define MDNS_LOG_DEFINITION(LEVEL, ...) \ do { if (mDNS_LoggingEnabled) LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, LEVEL, __VA_ARGS__); } while (0) #define debug_noop(...) do {} while(0) #define LogMsg(...) LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, __VA_ARGS__) #define LogOperation(...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO, __VA_ARGS__) #define LogSPS(...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO, __VA_ARGS__) #define LogInfo(...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO, __VA_ARGS__) #define LogDebug(...) MDNS_LOG_DEFINITION(MDNS_LOG_DEBUG, __VA_ARGS__) #elif (MDNS_GNU_VA_ARGS) #define MDNS_LOG_DEFINITION(LEVEL, ARGS...) \ do { if (mDNS_LoggingEnabled) LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, LEVEL, ARGS); } while (0) #define debug_noop(ARGS...) do {} while (0) #define LogMsg(ARGS... ) LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, ARGS) #define LogOperation(ARGS...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO, ARGS) #define LogSPS(ARGS...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO, ARGS) #define LogInfo(ARGS...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO, ARGS) #define LogDebug(ARGS...) MDNS_LOG_DEFINITION(MDNS_LOG_DEBUG, ARGS) #else #error "Unknown variadic macros" #endif #else // If your platform does not support variadic macros, you need to define the following variadic functions. // See mDNSShared/mDNSDebug.c for sample implementation #define debug_noop 1 ? (void)0 : (void) #define LogMsg LogMsg_ #define LogOperation (mDNS_LoggingEnabled == 0) ? ((void)0) : LogOperation_ #define LogSPS (mDNS_LoggingEnabled == 0) ? ((void)0) : LogSPS_ #define LogInfo (mDNS_LoggingEnabled == 0) ? ((void)0) : LogInfo_ #define LogDebug (mDNS_LoggingEnabled == 0) ? ((void)0) : LogDebug_ extern void LogMsg_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); extern void LogOperation_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); extern void LogSPS_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); extern void LogInfo_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); extern void LogDebug_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); #endif #if MDNS_DEBUGMSGS #define debugf debugf_ extern void debugf_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); #else #define debugf debug_noop #endif #if MDNS_DEBUGMSGS > 1 #define verbosedebugf verbosedebugf_ extern void verbosedebugf_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); #else #define verbosedebugf debug_noop #endif extern int mDNS_LoggingEnabled; extern int mDNS_PacketLoggingEnabled; extern int mDNS_McastLoggingEnabled; extern int mDNS_McastTracingEnabled; extern int mDNS_DebugMode; // If non-zero, LogMsg() writes to stderr instead of syslog extern const char ProgramName[]; extern void LogMsgWithLevel(mDNSLogCategory_t category, mDNSLogLevel_t level, const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4); // LogMsgNoIdent needs to be fixed so that it logs without the ident prefix like it used to // (or completely overhauled to use the new "log to a separate file" facility) #define LogMsgNoIdent LogMsg #if APPLE_OSX_mDNSResponder extern void LogFatalError(const char *format, ...); #else #define LogFatalError LogMsg #endif #if MDNS_MALLOC_DEBUGGING >= 1 extern void *mallocL(const char *msg, mDNSu32 size); extern void *callocL(const char *msg, mDNSu32 size); extern void freeL(const char *msg, void *x); #if APPLE_OSX_mDNSResponder extern void LogMemCorruption(const char *format, ...); #else #define LogMemCorruption LogMsg #endif #else #define mallocL(MSG, SIZE) malloc(SIZE) #define callocL(MSG, SIZE) calloc(1, SIZE) #define freeL(MSG, PTR) free(PTR) #endif #ifdef __cplusplus } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) /** @brief Write a log message to system's log storage(memory or disk). * * On Apple platform, os_log() will be called to log a message. * * @param CATEGORY A custom log object previously created by the os_log_create function, and such an object is * used to specify "subsystem" and "category". For mDNSResponder, the subsystem should always * be set to "com.apple.mDNSResponder"; and the category is used for categorization and * filtering of related log messages within the subsystem’s settings. We have 4 categories that * are pre-defined: MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_CATEGORY_UDNS, * MDNS_LOG_CATEGORY_SPS. If these categories are not enough, use os_log_create to create more. * * @param LEVEL The log level that determines the importance of the message. The levels are, in order of * decreasing importance: * MDNS_LOG_FAULT Fault-level messages are intended for capturing system-level errors * that are critical to the system. They are always saved in the data store. * MDNS_LOG_ERROR Error-level messages are intended for reporting process-level errors * that are unexpected and incorrect during the normal operation. They * are always saved in the data store. * MDNS_LOG_WARNING Warning-level messages are intended for capturing unexpected and * possible incorrect behavior that might be used later to root cause * an error or fault. They are are initially stored in memory buffers * and then moved to a data store. * MDNS_LOG_DEFAULT Default-level messages are intended for reporting things that might * result a failure. They are are initially stored in memory buffers * and then moved to a data store. * MDNS_LOG_INFO Info-level messages are intended for capturing information that may * be helpful, but isn’t essential, for troubleshooting errors. They * are initially stored in memory buffers, but will only be moved into * data store when faults and, optionally, errors occur. * MDNS_LOG_DEBUG Debug-level messages are intended for information that may be useful * during development or while troubleshooting a specific problem, Debug * logging should not be used in shipping software. They are only * captured in memory when debug logging is enabled through a * configuration change. * * @param FORMAT A constant string or format string that produces a human-readable log message. The format * string follows the IEEE printf specification, besides the following customized format specifiers: * %{mdnsresponder:domain_name}.*P the pointer to a DNS lable sequence * %{mdnsresponder:ip_addr}.20P the pointer to a mDNSAddr variable * %{network:in_addr}.4P the pointer to a mDNSv4Addr variable * %{network:in6_addr}.16P the pointer to a mDNSv6Addr variable * %{mdnsresponder:mac_addr}.6P the pointer to a 6-byte-length MAC address * * @param ... The parameter list that will be formated by the format string. Note that if the customized * format specifiers are used and the data length is not specified in the format string, the * size should be listed before the pointer to the data, for example: * "%{mdnsresponder:domain_name}.*P", (name ? (int)DomainNameLength((const domainname *)name) : 0), * */ #define LogRedact(CATEGORY, LEVEL, FORMAT, ...) os_log_with_type(CATEGORY, LEVEL, FORMAT, ## __VA_ARGS__) #else #if (MDNS_HAS_VA_ARG_MACROS) #if (MDNS_C99_VA_ARGS) #define LogRedact(CATEGORY, LEVEL, ...) \ do { if (mDNS_LoggingEnabled) LogMsgWithLevel(CATEGORY, LEVEL, __VA_ARGS__); } while (0) #elif (MDNS_GNU_VA_ARGS) #define LogRedact(CATEGORY, LEVEL, ARGS...) \ do { if (mDNS_LoggingEnabled) LogMsgWithLevel(CATEGORY, LEVEL, ARGS); } while (0) #else #error "Unknown variadic macros" #endif #else #define LogRedact (mDNS_LoggingEnabled == 0) ? ((void)0) : LogRedact_ extern void LogRedact_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); #endif #endif // MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) // The followings are the customized log specifier defined in os_log. For compatibility, we have to define it when it is // not on the Apple platform, for example, the Posix platform. The keyword "public" or "private" is used to control whether // the content would be redacted when the redaction is turned on: "public" means the content will always be printed; // "private" means the content will be printed as '> if the redaction is turned on, // only when the redaction is turned off, the content will be printed as what it should be. Note that the hash performed // to the data is a salted hashing transformation, and the salt is generated randomly on a per-process basis, meaning // that hashes cannot be correlated across processes or devices. #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_S "%{public}s" #define PRI_S "%{private, mask.hash}s" #else #define PUB_S "%s" #define PRI_S PUB_S #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_DM_NAME "%{public, mdnsresponder:domain_name}.*P" #define PRI_DM_NAME "%{private, mask.hash, mdnsresponder:domain_name}.*P" // When DM_NAME_PARAM is used, the file where the function is defined must include DNSEmbeddedAPI.h #define DM_NAME_PARAM(name) ((name) ? ((int)DomainNameLength((name))) : 0), (name) #else #define PUB_DM_NAME "%##s" #define PRI_DM_NAME PUB_DM_NAME #define DM_NAME_PARAM(name) (name) #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_IP_ADDR "%{public, mdnsresponder:ip_addr}.20P" #define PRI_IP_ADDR "%{private, mask.hash, mdnsresponder:ip_addr}.20P" #define PUB_IPv4_ADDR "%{public, network:in_addr}.4P" #define PRI_IPv4_ADDR "%{private, mask.hash, network:in_addr}.4P" #define PUB_IPv6_ADDR "%{public, network:in6_addr}.16P" #define PRI_IPv6_ADDR "%{private, mask.hash, network:in6_addr}.16P" #else #define PUB_IP_ADDR "%#a" #define PRI_IP_ADDR PUB_IP_ADDR #define PUB_IPv4_ADDR "%.4a" #define PRI_IPv4_ADDR PUB_IPv4_ADDR #define PUB_IPv6_ADDR "%.16a" #define PRI_IPv6_ADDR PUB_IPv6_ADDR #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_MAC_ADDR "%{public, mdnsresponder:mac_addr}.6P" #define PRI_MAC_ADDR "%{private, mask.hash, mdnsresponder:mac_addr}.6P" #else #define PUB_MAC_ADDR "%.6a" #define PRI_MAC_ADDR PUB_MAC_ADDR #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_DNSKEY "%{public, mdns:rd.dnskey}.*P" #define PRI_DNSKEY "%{private, mask.hash, mdns:rd.dnskey}.*P" #define DNSKEY_PARAM(rdata, rdata_length) (rdata_length), (rdata) #else #define PUB_DNSKEY "%p" #define PRI_DNSKEY PUB_DNSKEY #define DNSKEY_PARAM(rdata, rdata_length) (rdata) #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_DS "%{public, mdns:rd.ds}.*P" #define PRI_DS "%{private, mask.hash, mdns:rd.ds}.*P" #define DS_PARAM(rdata, rdata_length) (rdata_length), (rdata) #else #define PUB_DS "%p" #define PRI_DS PUB_DS #define DS_PARAM(rdata, rdata_length) (rdata) #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_NSEC "%{public, mdns:rd.nsec}.*P" #define PRI_NSEC "%{private, mask.hash, mdns:rd.nsec}.*P" #define NSEC_PARAM(rdata, rdata_length) (rdata_length), (rdata) #else #define PUB_NSEC "%p" #define PRI_NSEC PUB_NSEC #define NSEC_PARAM(rdata, rdata_length) (rdata) #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_NSEC3 "%{public, mdns:rd.nsec3}.*P" #define PRI_NSEC3 "%{private, mask.hash, mdns:rd.nsec3}.*P" #define NSEC3_PARAM(rdata, rdata_length) (rdata_length), (rdata) #else #define PUB_NSEC3 "%p" #define PRI_NSEC3 PUB_NSEC3 #define NSEC3_PARAM(rdata, rdata_length) (rdata) #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_RRSIG "%{public, mdns:rd.rrsig}.*P" #define PRI_RRSIG "%{private, mask.hash, mdns:rd.rrsig}.*P" #define RRSIG_PARAM(rdata, rdata_length) (rdata_length), (rdata) #else #define PUB_RRSIG "%p" #define PRI_RRSIG PUB_RRSIG #define RRSIG_PARAM(rdata, rdata_length) (rdata) #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) #define PUB_SVCB "%{public, mdns:rd.svcb}.*P" #define PRI_SVCB "%{private, mask.hash, mdns:rd.svcb}.*P" #define SVCB_PARAM(rdata, rdata_length) (rdata_length), (rdata) #else #define PUB_SVCB "%p" #define PRI_SVCB PUB_SVCB #define SVCB_PARAM(rdata, rdata_length) (rdata) #endif extern void LogToFD(int fd, const char *format, ...); #endif // __mDNSDebug_h /* * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. NOTE: If you're building an application that uses DNS Service Discovery this is probably NOT the header file you're looking for. In most cases you will want to use /usr/include/dns_sd.h instead. This header file defines the lowest level raw interface to mDNSCore, which is appropriate *only* on tiny embedded systems where everything runs in a single address space and memory is extremely constrained. All the APIs here are malloc-free, which means that the caller is responsible for passing in a pointer to the relevant storage that will be used in the execution of that call, and (when called with correct parameters) all the calls are guaranteed to succeed. There is never a case where a call can suffer intermittent failures because the implementation calls malloc() and sometimes malloc() returns NULL because memory is so limited that no more is available. This is primarily for devices that need to have precisely known fixed memory requirements, with absolutely no uncertainty or run-time variation, but that certainty comes at a cost of more difficult programming. For applications running on general-purpose desktop operating systems (Mac OS, Linux, Solaris, Windows, etc.) the API you should use is /usr/include/dns_sd.h, which defines the API by which multiple independent client processes communicate their DNS Service Discovery requests to a single "mdnsd" daemon running in the background. Even on platforms that don't run multiple independent processes in multiple independent address spaces, you can still use the preferred dns_sd.h APIs by linking in "dnssd_clientshim.c", which implements the standard "dns_sd.h" API calls, allocates any required storage using malloc(), and then calls through to the low-level malloc-free mDNSCore routines defined here. This has the benefit that even though you're running on a small embedded system with a single address space, you can still use the exact same client C code as you'd use on a general-purpose desktop system. */ #ifndef __mDNSEmbeddedAPI_h #define __mDNSEmbeddedAPI_h #if defined(EFI32) || defined(EFI64) || defined(EFIX64) // EFI doesn't have stdarg.h unless it's building with GCC. #include "Tiano.h" #if !defined(__GNUC__) #define va_list VA_LIST #define va_start(a, b) VA_START(a, b) #define va_end(a) VA_END(a) #define va_arg(a, b) VA_ARG(a, b) #endif #else #include // stdarg.h is required for for va_list support for the mDNS_vsnprintf declaration #endif #if APPLE_OSX_mDNSResponder #include #endif #include "mDNSFeatures.h" #include "mDNSDebug.h" // *************************************************************************** // Feature removal compile options & limited resource targets // The following compile options are responsible for removing certain features from mDNSCore to reduce the // memory footprint for use in embedded systems with limited resources. // UNICAST_DISABLED - disables unicast DNS functionality, including Wide Area Bonjour // SPC_DISABLED - disables Bonjour Sleep Proxy client // IDLESLEEPCONTROL_DISABLED - disables sleep control for Bonjour Sleep Proxy clients // In order to disable the above features pass the option to your compiler, e.g. -D UNICAST_DISABLED #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) #include #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #include "dnssec_v2_embedded.h" #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // Additionally, the LIMITED_RESOURCES_TARGET compile option will reduce the maximum DNS message sizes. #ifdef LIMITED_RESOURCES_TARGET // Don't support jumbo frames // 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total #define AbsoluteMaxDNSMessageData 1440 // StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record (6 + 256 bytes) #define MaximumRDSize 264 #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) #include "mdns_private.h" #endif #ifdef __cplusplus extern "C" { #endif // *************************************************************************** // Function scope indicators // If you see "mDNSlocal" before a function name in a C file, it means the function is not callable outside this file #ifndef mDNSlocal #define mDNSlocal static #endif // If you see "mDNSexport" before a symbol in a C file, it means the symbol is exported for use by clients // For every "mDNSexport" in a C file, there needs to be a corresponding "extern" declaration in some header file // (When a C file #includes a header file, the "extern" declarations tell the compiler: // "This symbol exists -- but not necessarily in this C file.") #ifndef mDNSexport #define mDNSexport #endif // Explanation: These local/export markers are a little habit of mine for signaling the programmers' intentions. // When "mDNSlocal" is just a synonym for "static", and "mDNSexport" is a complete no-op, you could be // forgiven for asking what purpose they serve. The idea is that if you see "mDNSexport" in front of a // function definition it means the programmer intended it to be exported and callable from other files // in the project. If you see "mDNSlocal" in front of a function definition it means the programmer // intended it to be private to that file. If you see neither in front of a function definition it // means the programmer forgot (so you should work out which it is supposed to be, and fix it). // Using "mDNSlocal" instead of "static" makes it easier to do a textual searches for one or the other. // For example you can do a search for "static" to find if any functions declare any local variables as "static" // (generally a bad idea unless it's also "const", because static storage usually risks being non-thread-safe) // without the results being cluttered with hundreds of matches for functions declared static. // - Stuart Cheshire // *************************************************************************** // Structure packing macro // If we're not using GNUC, it's not fatal. // Most compilers naturally pack the on-the-wire structures correctly anyway, so a plain "struct" is usually fine. // In the event that structures are not packed correctly, mDNS_Init() will detect this and report an error, so the // developer will know what's wrong, and can investigate what needs to be done on that compiler to provide proper packing. #ifndef packedstruct #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9))) #define packedstruct struct __attribute__((__packed__)) #define packedunion union __attribute__((__packed__)) #else #define packedstruct struct #define packedunion union #endif #endif #ifndef fallthrough #if __clang__ #if __has_c_attribute(fallthrough) #define fallthrough() [[fallthrough]] #else #define fallthrough() #endif #elif __GNUC__ #define fallthrough() __attribute__((fallthrough)) #else #define fallthrough() #endif // __GNUC__ #endif // fallthrough // *************************************************************************** #if 0 #pragma mark - DNS Resource Record class and type constants #endif typedef enum // From RFC 1035 { kDNSClass_IN = 1, // Internet kDNSClass_CS = 2, // CSNET kDNSClass_CH = 3, // CHAOS kDNSClass_HS = 4, // Hesiod kDNSClass_NONE = 254, // Used in DNS UPDATE [RFC 2136] kDNSClass_Mask = 0x7FFF, // Multicast DNS uses the bottom 15 bits to identify the record class... kDNSClass_UniqueRRSet = 0x8000, // ... and the top bit indicates that all other cached records are now invalid kDNSQClass_ANY = 255, // Not a DNS class, but a DNS query class, meaning "all classes" kDNSQClass_UnicastResponse = 0x8000 // Top bit set in a question means "unicast response acceptable" } DNS_ClassValues; typedef enum // From RFC 1035 { kDNSType_A = 1, // 1 Address kDNSType_NS, // 2 Name Server kDNSType_MD, // 3 Mail Destination kDNSType_MF, // 4 Mail Forwarder kDNSType_CNAME, // 5 Canonical Name kDNSType_SOA, // 6 Start of Authority kDNSType_MB, // 7 Mailbox kDNSType_MG, // 8 Mail Group kDNSType_MR, // 9 Mail Rename kDNSType_NULL, // 10 NULL RR kDNSType_WKS, // 11 Well-known-service kDNSType_PTR, // 12 Domain name pointer kDNSType_HINFO, // 13 Host information kDNSType_MINFO, // 14 Mailbox information kDNSType_MX, // 15 Mail Exchanger kDNSType_TXT, // 16 Arbitrary text string kDNSType_RP, // 17 Responsible person kDNSType_AFSDB, // 18 AFS cell database kDNSType_X25, // 19 X_25 calling address kDNSType_ISDN, // 20 ISDN calling address kDNSType_RT, // 21 Router kDNSType_NSAP, // 22 NSAP address kDNSType_NSAP_PTR, // 23 Reverse NSAP lookup (deprecated) kDNSType_SIG, // 24 Security signature kDNSType_KEY, // 25 Security key kDNSType_PX, // 26 X.400 mail mapping kDNSType_GPOS, // 27 Geographical position (withdrawn) kDNSType_AAAA, // 28 IPv6 Address kDNSType_LOC, // 29 Location Information kDNSType_NXT, // 30 Next domain (security) kDNSType_EID, // 31 Endpoint identifier kDNSType_NIMLOC, // 32 Nimrod Locator kDNSType_SRV, // 33 Service record kDNSType_ATMA, // 34 ATM Address kDNSType_NAPTR, // 35 Naming Authority PoinTeR kDNSType_KX, // 36 Key Exchange kDNSType_CERT, // 37 Certification record kDNSType_A6, // 38 IPv6 Address (deprecated) kDNSType_DNAME, // 39 Non-terminal DNAME (for IPv6) kDNSType_SINK, // 40 Kitchen sink (experimental) kDNSType_OPT, // 41 EDNS0 option (meta-RR) kDNSType_APL, // 42 Address Prefix List kDNSType_DS, // 43 Delegation Signer kDNSType_SSHFP, // 44 SSH Key Fingerprint kDNSType_IPSECKEY, // 45 IPSECKEY kDNSType_RRSIG, // 46 RRSIG kDNSType_NSEC, // 47 Denial of Existence kDNSType_DNSKEY, // 48 DNSKEY kDNSType_DHCID, // 49 DHCP Client Identifier kDNSType_NSEC3, // 50 Hashed Authenticated Denial of Existence kDNSType_NSEC3PARAM, // 51 Hashed Authenticated Denial of Existence kDNSType_HIP = 55, // 55 Host Identity Protocol kDNSType_SVCB = 64, // 64 Service Binding kDNSType_HTTPS, // 65 HTTPS Service Binding kDNSType_SPF = 99, // 99 Sender Policy Framework for E-Mail kDNSType_UINFO, // 100 IANA-Reserved kDNSType_UID, // 101 IANA-Reserved kDNSType_GID, // 102 IANA-Reserved kDNSType_UNSPEC, // 103 IANA-Reserved kDNSType_TKEY = 249, // 249 Transaction key kDNSType_TSIG, // 250 Transaction signature kDNSType_IXFR, // 251 Incremental zone transfer kDNSType_AXFR, // 252 Transfer zone of authority kDNSType_MAILB, // 253 Transfer mailbox records kDNSType_MAILA, // 254 Transfer mail agent records kDNSQType_ANY // Not a DNS type, but a DNS query type, meaning "all types" } DNS_TypeValues; // *************************************************************************** #if 0 #pragma mark - #pragma mark - Simple types #endif // mDNS defines its own names for these common types to simplify portability across // multiple platforms that may each have their own (different) names for these types. typedef unsigned char mDNSBool; typedef signed char mDNSs8; typedef unsigned char mDNSu8; typedef signed short mDNSs16; typedef unsigned short mDNSu16; // Source: http://www.unix.org/version2/whatsnew/lp64_wp.html // http://software.intel.com/sites/products/documentation/hpc/mkl/lin/MKL_UG_structure/Support_for_ILP64_Programming.htm // It can be safely assumed that int is 32bits on the platform #if defined(_ILP64) || defined(__ILP64__) typedef signed int32 mDNSs32; typedef unsigned int32 mDNSu32; #else typedef signed int mDNSs32; typedef unsigned int mDNSu32; #endif // To enforce useful type checking, we make mDNSInterfaceID be a pointer to a dummy struct // This way, mDNSInterfaceIDs can be assigned, and compared with each other, but not with other types // Declaring the type to be the typical generic "void *" would lack this type checking typedef const struct mDNSInterfaceID_dummystruct { void *dummy; } *mDNSInterfaceID; // Use when printing interface IDs; the interface ID is actually a pointer, but we're only using // the pointer as a unique identifier, and in special cases it's actually a small number. So there's // little point in printing all 64 bits--the upper 32 bits in particular will not add information. #define IIDPrintable(x) ((uint32_t)(uintptr_t)(x)) // These types are for opaque two- and four-byte identifiers. // The "NotAnInteger" fields of the unions allow the value to be conveniently passed around in a // register for the sake of efficiency, and compared for equality or inequality, but don't forget -- // just because it is in a register doesn't mean it is an integer. Operations like greater than, // less than, add, multiply, increment, decrement, etc., are undefined for opaque identifiers, // and if you make the mistake of trying to do those using the NotAnInteger field, then you'll // find you get code that doesn't work consistently on big-endian and little-endian machines. #if defined(_WIN32) #pragma pack(push,2) #elif !defined(__GNUC__) #pragma pack(1) #endif typedef union { mDNSu8 b[ 2]; mDNSu16 NotAnInteger; } mDNSOpaque16; typedef union { mDNSu8 b[ 4]; mDNSu32 NotAnInteger; } mDNSOpaque32; typedef packedunion { mDNSu8 b[ 6]; mDNSu16 w[3]; mDNSu32 l[1]; } mDNSOpaque48; typedef union { mDNSu8 b[ 8]; mDNSu16 w[4]; mDNSu32 l[2]; } mDNSOpaque64; typedef union { mDNSu8 b[16]; mDNSu16 w[8]; mDNSu32 l[4]; } mDNSOpaque128; #if defined(_WIN32) #pragma pack(pop) #elif !defined(__GNUC__) #pragma pack() #endif typedef mDNSOpaque16 mDNSIPPort; // An IP port is a two-byte opaque identifier (not an integer) typedef mDNSOpaque32 mDNSv4Addr; // An IP address is a four-byte opaque identifier (not an integer) typedef mDNSOpaque128 mDNSv6Addr; // An IPv6 address is a 16-byte opaque identifier (not an integer) typedef mDNSOpaque48 mDNSEthAddr; // An Ethernet address is a six-byte opaque identifier (not an integer) // Bit operations for opaque 64 bit quantity. Uses the 32 bit quantity(l[2]) to set and clear bits #define mDNSNBBY 8 #define bit_set_opaque64(op64, index) (op64.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] |= (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY)))) #define bit_clr_opaque64(op64, index) (op64.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] &= ~(1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY)))) #define bit_get_opaque64(op64, index) (op64.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] & (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY)))) // Bit operations for opaque 128 bit quantity. Uses the 32 bit quantity(l[4]) to set and clear bits #define bit_set_opaque128(op128, index) (op128.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] |= (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY)))) #define bit_clr_opaque128(op128, index) (op128.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] &= ~(1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY)))) #define bit_get_opaque128(op128, index) (op128.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] & (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY)))) typedef enum { mDNSAddrType_None = 0, mDNSAddrType_IPv4 = 4, mDNSAddrType_IPv6 = 6, mDNSAddrType_Unknown = ~0 // Special marker value used in known answer list recording } mDNSAddr_Type; typedef enum { mDNSTransport_None = 0, mDNSTransport_UDP = 1, mDNSTransport_TCP = 2 } mDNSTransport_Type; typedef struct { mDNSs32 type; union { mDNSv6Addr v6; mDNSv4Addr v4; } ip; } mDNSAddr; enum { mDNSfalse = 0, mDNStrue = 1 }; #define mDNSNULL 0L enum { mStatus_Waiting = 1, mStatus_NoError = 0, // mDNS return values are in the range FFFE FF00 (-65792) to FFFE FFFF (-65537) // The top end of the range (FFFE FFFF) is used for error codes; // the bottom end of the range (FFFE FF00) is used for non-error values; // Error codes: mStatus_UnknownErr = -65537, // First value: 0xFFFE FFFF mStatus_NoSuchNameErr = -65538, mStatus_NoMemoryErr = -65539, mStatus_BadParamErr = -65540, mStatus_BadReferenceErr = -65541, mStatus_BadStateErr = -65542, mStatus_BadFlagsErr = -65543, mStatus_UnsupportedErr = -65544, mStatus_NotInitializedErr = -65545, mStatus_NoCache = -65546, mStatus_AlreadyRegistered = -65547, mStatus_NameConflict = -65548, mStatus_Invalid = -65549, mStatus_Firewall = -65550, mStatus_Incompatible = -65551, mStatus_BadInterfaceErr = -65552, mStatus_Refused = -65553, mStatus_NoSuchRecord = -65554, mStatus_NoAuth = -65555, mStatus_NoSuchKey = -65556, mStatus_NATTraversal = -65557, mStatus_DoubleNAT = -65558, mStatus_BadTime = -65559, mStatus_BadSig = -65560, // while we define this per RFC 2845, BIND 9 returns Refused for bad/missing signatures mStatus_BadKey = -65561, mStatus_TransientErr = -65562, // transient failures, e.g. sending packets shortly after a network transition or wake from sleep mStatus_ServiceNotRunning = -65563, // Background daemon not running mStatus_NATPortMappingUnsupported = -65564, // NAT doesn't support PCP, NAT-PMP or UPnP mStatus_NATPortMappingDisabled = -65565, // NAT supports PCP, NAT-PMP or UPnP, but it's disabled by the administrator mStatus_NoRouter = -65566, mStatus_PollingMode = -65567, mStatus_Timeout = -65568, mStatus_DefunctConnection = -65569, mStatus_PolicyDenied = -65570, // -65571 to -65785 currently unused; available for allocation // udp connection status mStatus_HostUnreachErr = -65786, // tcp connection status mStatus_ConnPending = -65787, mStatus_ConnFailed = -65788, mStatus_ConnEstablished = -65789, // Non-error values: mStatus_GrowCache = -65790, mStatus_ConfigChanged = -65791, mStatus_MemFree = -65792 // Last value: 0xFFFE FF00 // mStatus_MemFree is the last legal mDNS error code, at the end of the range allocated for mDNS }; typedef mDNSs32 mStatus; #define MaxIp 5 // Needs to be consistent with MaxInputIf in dns_services.h typedef enum { q_stop = 0, q_start } q_state; typedef enum { reg_stop = 0, reg_start } reg_state; // RFC 1034/1035 specify that a domain label consists of a length byte plus up to 63 characters #define MAX_DOMAIN_LABEL 63 typedef struct { mDNSu8 c[ 64]; } domainlabel; // One label: length byte and up to 63 characters // RFC 1034/1035/2181 specify that a domain name (length bytes and data bytes) may be up to 255 bytes long, // plus the terminating zero at the end makes 256 bytes total in the on-the-wire format. #define MAX_DOMAIN_NAME 256 typedef struct { mDNSu8 c[256]; } domainname; // Up to 256 bytes of length-prefixed domainlabels typedef struct { mDNSu8 c[256]; } UTF8str255; // Null-terminated C string // The longest legal textual form of a DNS name is 1009 bytes, including the C-string terminating NULL at the end. // Explanation: // When a native domainname object is converted to printable textual form using ConvertDomainNameToCString(), // non-printing characters are represented in the conventional DNS way, as '\ddd', where ddd is a three-digit decimal number. // The longest legal domain name is 256 bytes, in the form of four labels as shown below: // Length byte, 63 data bytes, length byte, 63 data bytes, length byte, 63 data bytes, length byte, 62 data bytes, zero byte. // Each label is encoded textually as characters followed by a trailing dot. // If every character has to be represented as a four-byte escape sequence, then this makes the maximum textual form four labels // plus the C-string terminating NULL as shown below: // 63*4+1 + 63*4+1 + 63*4+1 + 62*4+1 + 1 = 1009. // Note that MAX_ESCAPED_DOMAIN_LABEL is not normally used: If you're only decoding a single label, escaping is usually not required. // It is for domain names, where dots are used as label separators, that proper escaping is vital. #define MAX_ESCAPED_DOMAIN_LABEL 254 #define MAX_ESCAPED_DOMAIN_NAME 1009 // MAX_REVERSE_MAPPING_NAME // For IPv4: "123.123.123.123.in-addr.arpa." 30 bytes including terminating NUL // For IPv6: "x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.ip6.arpa." 74 bytes including terminating NUL #define MAX_REVERSE_MAPPING_NAME_V4 30 #define MAX_REVERSE_MAPPING_NAME_V6 74 #define MAX_REVERSE_MAPPING_NAME 74 // Most records have a TTL of 75 minutes, so that their 80% cache-renewal query occurs once per hour. // For records containing a hostname (in the name on the left, or in the rdata on the right), // like A, AAAA, reverse-mapping PTR, and SRV, we use a two-minute TTL by default, because we don't want // them to hang around for too long in the cache if the host in question crashes or otherwise goes away. #define kStandardTTL (3600UL * 100 / 80) #define kHostNameTTL 120UL // Multicast DNS uses announcements (gratuitous responses) to update peer caches. // This means it is feasible to use relatively larger TTL values than we might otherwise // use, because we have a cache coherency protocol to keep the peer caches up to date. // With Unicast DNS, once an authoritative server gives a record with a certain TTL value to a client // or caching server, that client or caching server is entitled to hold onto the record until its TTL // expires, and has no obligation to contact the authoritative server again until that time arrives. // This means that whereas Multicast DNS can use announcements to pre-emptively update stale data // before it would otherwise have expired, standard Unicast DNS (not using LLQs) has no equivalent // mechanism, and TTL expiry is the *only* mechanism by which stale data gets deleted. Because of this, // we currently limit the TTL to ten seconds in such cases where no dynamic cache updating is possible. #define kStaticCacheTTL 10 #define DefaultTTLforRRType(X) (((X) == kDNSType_A || (X) == kDNSType_AAAA || (X) == kDNSType_SRV) ? kHostNameTTL : kStandardTTL) #define mDNS_KeepaliveRecord(rr) ((rr)->rrtype == kDNSType_NULL && SameDomainLabel(SecondLabel((rr)->name)->c, (mDNSu8 *)"\x0A_keepalive")) // Number of times keepalives are sent if no ACK is received before waking up the system // this is analogous to net.inet.tcp.keepcnt #define kKeepaliveRetryCount 10 // The frequency at which keepalives are retried if no ACK is received #define kKeepaliveRetryInterval 30 typedef struct AuthRecord_struct AuthRecord; typedef struct ServiceRecordSet_struct ServiceRecordSet; typedef struct CacheRecord_struct CacheRecord; typedef struct CacheGroup_struct CacheGroup; typedef struct AuthGroup_struct AuthGroup; typedef struct DNSQuestion_struct DNSQuestion; typedef struct ZoneData_struct ZoneData; typedef struct mDNS_struct mDNS; typedef struct mDNS_PlatformSupport_struct mDNS_PlatformSupport; typedef struct NATTraversalInfo_struct NATTraversalInfo; typedef struct ResourceRecord_struct ResourceRecord; // Structure to abstract away the differences between TCP/SSL sockets, and one for UDP sockets // The actual definition of these structures appear in the appropriate platform support code typedef struct TCPListener_struct TCPListener; typedef struct TCPSocket_struct TCPSocket; typedef struct UDPSocket_struct UDPSocket; // *************************************************************************** #if 0 #pragma mark - #pragma mark - DNS Message structures #endif #define mDNS_numZones numQuestions #define mDNS_numPrereqs numAnswers #define mDNS_numUpdates numAuthorities typedef struct { mDNSOpaque16 id; mDNSOpaque16 flags; mDNSu16 numQuestions; mDNSu16 numAnswers; mDNSu16 numAuthorities; mDNSu16 numAdditionals; } DNSMessageHeader; // We can send and receive packets up to 9000 bytes (Ethernet Jumbo Frame size, if that ever becomes widely used) // However, in the normal case we try to limit packets to 1500 bytes so that we don't get IP fragmentation on standard Ethernet // 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total #ifndef AbsoluteMaxDNSMessageData #define AbsoluteMaxDNSMessageData 8940 #endif #define NormalMaxDNSMessageData 1440 typedef struct { DNSMessageHeader h; // Note: Size 12 bytes mDNSu8 data[AbsoluteMaxDNSMessageData]; // 40 (IPv6) + 8 (UDP) + 12 (DNS header) + 8940 (data) = 9000 } DNSMessage; typedef struct tcpInfo_t { mDNS *m; TCPSocket *sock; DNSMessage request; int requestLen; DNSQuestion *question; // For queries AuthRecord *rr; // For record updates mDNSAddr Addr; mDNSIPPort Port; mDNSIPPort SrcPort; DNSMessage *reply; mDNSu16 replylen; unsigned long nread; int numReplies; } tcpInfo_t; // *************************************************************************** #if 0 #pragma mark - #pragma mark - Other Packet Format Structures #endif typedef packedstruct { mDNSEthAddr dst; mDNSEthAddr src; mDNSOpaque16 ethertype; } EthernetHeader; // 14 bytes typedef packedstruct { mDNSOpaque16 hrd; mDNSOpaque16 pro; mDNSu8 hln; mDNSu8 pln; mDNSOpaque16 op; mDNSEthAddr sha; mDNSv4Addr spa; mDNSEthAddr tha; mDNSv4Addr tpa; } ARP_EthIP; // 28 bytes typedef packedstruct { mDNSu8 vlen; mDNSu8 tos; mDNSOpaque16 totlen; mDNSOpaque16 id; mDNSOpaque16 flagsfrags; mDNSu8 ttl; mDNSu8 protocol; // Payload type: 0x06 = TCP, 0x11 = UDP mDNSu16 checksum; mDNSv4Addr src; mDNSv4Addr dst; } IPv4Header; // 20 bytes typedef packedstruct { mDNSu32 vcf; // Version, Traffic Class, Flow Label mDNSu16 len; // Payload Length mDNSu8 pro; // Type of next header: 0x06 = TCP, 0x11 = UDP, 0x3A = ICMPv6 mDNSu8 ttl; // Hop Limit mDNSv6Addr src; mDNSv6Addr dst; } IPv6Header; // 40 bytes typedef packedstruct { mDNSv6Addr src; mDNSv6Addr dst; mDNSOpaque32 len; mDNSOpaque32 pro; } IPv6PseudoHeader; // 40 bytes typedef union { mDNSu8 bytes[20]; ARP_EthIP arp; IPv4Header v4; IPv6Header v6; } NetworkLayerPacket; typedef packedstruct { mDNSIPPort src; mDNSIPPort dst; mDNSu32 seq; mDNSu32 ack; mDNSu8 offset; mDNSu8 flags; mDNSu16 window; mDNSu16 checksum; mDNSu16 urgent; } TCPHeader; // 20 bytes; IP protocol type 0x06 typedef struct { mDNSInterfaceID IntfId; mDNSu32 seq; mDNSu32 ack; mDNSu16 window; } mDNSTCPInfo; typedef packedstruct { mDNSIPPort src; mDNSIPPort dst; mDNSu16 len; // Length including UDP header (i.e. minimum value is 8 bytes) mDNSu16 checksum; } UDPHeader; // 8 bytes; IP protocol type 0x11 typedef struct { mDNSu8 type; // 0x87 == Neighbor Solicitation, 0x88 == Neighbor Advertisement mDNSu8 code; mDNSu16 checksum; mDNSu32 flags_res; // R/S/O flags and reserved bits mDNSv6Addr target; // Typically 8 bytes of options are also present } IPv6NDP; // 24 bytes or more; IP protocol type 0x3A typedef struct { mDNSAddr ipaddr; char ethaddr[18]; } IPAddressMACMapping; #define NDP_Sol 0x87 #define NDP_Adv 0x88 #define NDP_Router 0x80 #define NDP_Solicited 0x40 #define NDP_Override 0x20 #define NDP_SrcLL 1 #define NDP_TgtLL 2 typedef union { mDNSu8 bytes[20]; TCPHeader tcp; UDPHeader udp; IPv6NDP ndp; } TransportLayerPacket; typedef packedstruct { mDNSOpaque64 InitiatorCookie; mDNSOpaque64 ResponderCookie; mDNSu8 NextPayload; mDNSu8 Version; mDNSu8 ExchangeType; mDNSu8 Flags; mDNSOpaque32 MessageID; mDNSu32 Length; } IKEHeader; // 28 bytes // *************************************************************************** #if 0 #pragma mark - #pragma mark - Resource Record structures #endif // Authoritative Resource Records: // There are four basic types: Shared, Advisory, Unique, Known Unique // * Shared Resource Records do not have to be unique // -- Shared Resource Records are used for DNS-SD service PTRs // -- It is okay for several hosts to have RRs with the same name but different RDATA // -- We use a random delay on responses to reduce collisions when all the hosts respond to the same query // -- These RRs typically have moderately high TTLs (e.g. one hour) // -- These records are announced on startup and topology changes for the benefit of passive listeners // -- These records send a goodbye packet when deregistering // // * Advisory Resource Records are like Shared Resource Records, except they don't send a goodbye packet // // * Unique Resource Records should be unique among hosts within any given mDNS scope // -- The majority of Resource Records are of this type // -- If two entities on the network have RRs with the same name but different RDATA, this is a conflict // -- Responses may be sent immediately, because only one host should be responding to any particular query // -- These RRs typically have low TTLs (e.g. a few minutes) // -- On startup and after topology changes, a host issues queries to verify uniqueness // * Known Unique Resource Records are treated like Unique Resource Records, except that mDNS does // not have to verify their uniqueness because this is already known by other means (e.g. the RR name // is derived from the host's IP or Ethernet address, which is already known to be a unique identifier). // Summary of properties of different record types: // Probe? Does this record type send probes before announcing? // Conflict? Does this record type react if we observe an apparent conflict? // Goodbye? Does this record type send a goodbye packet on departure? // // Probe? Conflict? Goodbye? Notes // Unregistered Should not appear in any list (sanity check value) // Shared No No Yes e.g. Service PTR record // Deregistering No No Yes Shared record about to announce its departure and leave the list // Advisory No No No // Unique Yes Yes No Record intended to be unique -- will probe to verify // Verified Yes Yes No Record has completed probing, and is verified unique // KnownUnique No Yes No Record is assumed by other means to be unique // Valid lifecycle of a record: // Unregistered -> Shared -> Deregistering -(goodbye)-> Unregistered // Unregistered -> Advisory -> Unregistered // Unregistered -> Unique -(probe)-> Verified -> Unregistered // Unregistered -> KnownUnique -> Unregistered // Each Authoritative kDNSRecordType has only one bit set. This makes it easy to quickly see if a record // is one of a particular set of types simply by performing the appropriate bitwise masking operation. // Cache Resource Records (received from the network): // There are four basic types: Answer, Unique Answer, Additional, Unique Additional // Bit 7 (the top bit) of kDNSRecordType is always set for Cache Resource Records; always clear for Authoritative Resource Records // Bit 6 (value 0x40) is set for answer records; clear for authority/additional records // Bit 5 (value 0x20) is set for records received with the kDNSClass_UniqueRRSet typedef enum { kDNSRecordTypeUnregistered = 0x00, // Not currently in any list kDNSRecordTypeDeregistering = 0x01, // Shared record about to announce its departure and leave the list kDNSRecordTypeUnique = 0x02, // Will become a kDNSRecordTypeVerified when probing is complete kDNSRecordTypeAdvisory = 0x04, // Like Shared, but no goodbye packet kDNSRecordTypeShared = 0x08, // Shared means record name does not have to be unique -- use random delay on responses kDNSRecordTypeVerified = 0x10, // Unique means mDNS should check that name is unique (and then send immediate responses) kDNSRecordTypeKnownUnique = 0x20, // Known Unique means mDNS can assume name is unique without checking // For Dynamic Update records, Known Unique means the record must already exist on the server. kDNSRecordTypeUniqueMask = (kDNSRecordTypeUnique | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique), kDNSRecordTypeActiveSharedMask = (kDNSRecordTypeAdvisory | kDNSRecordTypeShared), kDNSRecordTypeActiveUniqueMask = (kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique), kDNSRecordTypeActiveMask = (kDNSRecordTypeActiveSharedMask | kDNSRecordTypeActiveUniqueMask), kDNSRecordTypePacketAdd = 0x80, // Received in the Additional Section of a DNS Response kDNSRecordTypePacketAddUnique = 0x90, // Received in the Additional Section of a DNS Response with kDNSClass_UniqueRRSet set kDNSRecordTypePacketAuth = 0xA0, // Received in the Authorities Section of a DNS Response kDNSRecordTypePacketAuthUnique = 0xB0, // Received in the Authorities Section of a DNS Response with kDNSClass_UniqueRRSet set kDNSRecordTypePacketAns = 0xC0, // Received in the Answer Section of a DNS Response kDNSRecordTypePacketAnsUnique = 0xD0, // Received in the Answer Section of a DNS Response with kDNSClass_UniqueRRSet set kDNSRecordTypePacketNegative = 0xF0, // Pseudo-RR generated to cache non-existence results like NXDomain kDNSRecordTypePacketUniqueMask = 0x10 // True for PacketAddUnique, PacketAnsUnique, PacketAuthUnique, kDNSRecordTypePacketNegative } kDNSRecordTypes; typedef packedstruct { mDNSu16 priority; mDNSu16 weight; mDNSIPPort port; domainname target; } rdataSRV; typedef packedstruct { mDNSu16 preference; domainname exchange; } rdataMX; typedef packedstruct { domainname mbox; domainname txt; } rdataRP; typedef packedstruct { mDNSu16 preference; domainname map822; domainname mapx400; } rdataPX; typedef packedstruct { domainname mname; domainname rname; mDNSs32 serial; // Modular counter; increases when zone changes mDNSu32 refresh; // Time in seconds that a slave waits after successful replication of the database before it attempts replication again mDNSu32 retry; // Time in seconds that a slave waits after an unsuccessful replication attempt before it attempts replication again mDNSu32 expire; // Time in seconds that a slave holds on to old data while replication attempts remain unsuccessful mDNSu32 min; // Nominally the minimum record TTL for this zone, in seconds; also used for negative caching. } rdataSOA; typedef enum { platform_OSX = 1, // OSX Platform platform_iOS, // iOS Platform platform_Atv, // Atv Platform platform_NonApple // Non-Apple (Windows, POSIX) Platform } Platform_t; // EDNS Option Code registrations are recorded in the "DNS EDNS0 Options" section of // #define kDNSOpt_LLQ 1 #define kDNSOpt_Lease 2 #define kDNSOpt_NSID 3 #define kDNSOpt_Owner 4 #define kDNSOpt_Trace 65001 // 65001-65534 Reserved for Local/Experimental Use typedef struct { mDNSu16 vers; mDNSu16 llqOp; mDNSu16 err; // Or UDP reply port, in setup request // Note: In the in-memory form, there's typically a two-byte space here, so that the following 64-bit id is word-aligned mDNSOpaque64 id; mDNSu32 llqlease; } LLQOptData; typedef struct { mDNSu8 vers; // Version number of this Owner OPT record mDNSs8 seq; // Sleep/wake epoch mDNSEthAddr HMAC; // Host's primary identifier (e.g. MAC of on-board Ethernet) mDNSEthAddr IMAC; // Interface's MAC address (if different to primary MAC) mDNSOpaque48 password; // Optional password } OwnerOptData; typedef struct { mDNSu8 platf; // Running platform (see enum Platform_t) mDNSu32 mDNSv; // mDNSResponder Version (DNS_SD_H defined in dns_sd.h) } TracerOptData; // Note: rdataOPT format may be repeated an arbitrary number of times in a single resource record typedef struct { mDNSu16 opt; mDNSu16 optlen; union { LLQOptData llq; mDNSu32 updatelease; OwnerOptData owner; TracerOptData tracer; } u; } rdataOPT; // Space needed to put OPT records into a packet: // Header 11 bytes (name 1, type 2, class 2, TTL 4, length 2) // LLQ rdata 18 bytes (opt 2, len 2, vers 2, op 2, err 2, id 8, lease 4) // Lease rdata 8 bytes (opt 2, len 2, lease 4) // Owner rdata 12-24 bytes (opt 2, len 2, owner 8-20) // Trace rdata 9 bytes (opt 2, len 2, platf 1, mDNSv 4) #define DNSOpt_Header_Space 11 #define DNSOpt_LLQData_Space (4 + 2 + 2 + 2 + 8 + 4) #define DNSOpt_LeaseData_Space (4 + 4) #define DNSOpt_OwnerData_ID_Space (4 + 2 + 6) #define DNSOpt_OwnerData_ID_Wake_Space (4 + 2 + 6 + 6) #define DNSOpt_OwnerData_ID_Wake_PW4_Space (4 + 2 + 6 + 6 + 4) #define DNSOpt_OwnerData_ID_Wake_PW6_Space (4 + 2 + 6 + 6 + 6) #define DNSOpt_TraceData_Space (4 + 1 + 4) #define ValidOwnerLength(X) ( (X) == DNSOpt_OwnerData_ID_Space - 4 || \ (X) == DNSOpt_OwnerData_ID_Wake_Space - 4 || \ (X) == DNSOpt_OwnerData_ID_Wake_PW4_Space - 4 || \ (X) == DNSOpt_OwnerData_ID_Wake_PW6_Space - 4 ) #define DNSOpt_Owner_Space(A,B) (mDNSSameEthAddress((A),(B)) ? DNSOpt_OwnerData_ID_Space : DNSOpt_OwnerData_ID_Wake_Space) #define DNSOpt_Data_Space(O) ( \ (O)->opt == kDNSOpt_LLQ ? DNSOpt_LLQData_Space : \ (O)->opt == kDNSOpt_Lease ? DNSOpt_LeaseData_Space : \ (O)->opt == kDNSOpt_Trace ? DNSOpt_TraceData_Space : \ (O)->opt == kDNSOpt_Owner ? DNSOpt_Owner_Space(&(O)->u.owner.HMAC, &(O)->u.owner.IMAC) : 0x10000) // NSEC record is defined in RFC 4034. // 16 bit RRTYPE space is split into 256 windows and each window has 256 bits (32 bytes). // If we create a structure for NSEC, it's size would be: // // 256 bytes domainname 'nextname' // + 256 * 34 = 8704 bytes of bitmap data // = 8960 bytes total // // This would be a waste, as types about 256 are not very common. But it would be odd, if we receive // a type above 256 (.US zone had TYPE65534 when this code was written) and not able to handle it. // Hence, we handle any size by not fixing a strucure in place. The following is just a placeholder // and never used anywhere. // #define NSEC_MCAST_WINDOW_SIZE 32 typedef struct { domainname *next; //placeholders are uncommented because C89 in Windows requires that a struct has at least a member. char bitmap[32]; } rdataNSEC; // StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record (6 + 256 bytes) // MaximumRDSize is 8K the absolute maximum we support (at least for now) #define StandardAuthRDSize 264 #ifndef MaximumRDSize #define MaximumRDSize 8192 #endif // InlineCacheRDSize is 68 // Records received from the network with rdata this size or less have their rdata stored right in the CacheRecord object // Records received from the network with rdata larger than this have additional storage allocated for the rdata // A quick unscientific sample from a busy network at Apple with lots of machines revealed this: // 1461 records in cache // 292 were one-byte TXT records // 136 were four-byte A records // 184 were sixteen-byte AAAA records // 780 were various PTR, TXT and SRV records from 12-64 bytes // Only 69 records had rdata bigger than 64 bytes // Note that since CacheRecord object and a CacheGroup object are allocated out of the same pool, it's sensible to // have them both be the same size. Making one smaller without making the other smaller won't actually save any memory. #define InlineCacheRDSize 68 // The RDataBody union defines the common rdata types that fit into our 264-byte limit typedef union { mDNSu8 data[StandardAuthRDSize]; mDNSv4Addr ipv4; // For 'A' record domainname name; // For PTR, NS, CNAME, DNAME UTF8str255 txt; rdataMX mx; mDNSv6Addr ipv6; // For 'AAAA' record rdataSRV srv; rdataOPT opt[2]; // For EDNS0 OPT record; RDataBody may contain multiple variable-length rdataOPT objects packed together } RDataBody; // The RDataBody2 union is the same as above, except it includes fields for the larger types like soa, rp, px typedef union { mDNSu8 data[StandardAuthRDSize]; mDNSv4Addr ipv4; // For 'A' record domainname name; // For PTR, NS, CNAME, DNAME rdataSOA soa; // This is large; not included in the normal RDataBody definition UTF8str255 txt; rdataMX mx; rdataRP rp; // This is large; not included in the normal RDataBody definition rdataPX px; // This is large; not included in the normal RDataBody definition mDNSv6Addr ipv6; // For 'AAAA' record rdataSRV srv; rdataOPT opt[2]; // For EDNS0 OPT record; RDataBody may contain multiple variable-length rdataOPT objects packed together } RDataBody2; typedef struct { mDNSu16 MaxRDLength; // Amount of storage allocated for rdata (usually sizeof(RDataBody)) mDNSu16 padding; // So that RDataBody is aligned on 32-bit boundary RDataBody u; } RData; // sizeofRDataHeader should be 4 bytes #define sizeofRDataHeader (sizeof(RData) - sizeof(RDataBody)) // RData_small is a smaller version of the RData object, used for inline data storage embedded in a CacheRecord_struct typedef struct { mDNSu16 MaxRDLength; // Storage allocated for data (may be greater than InlineCacheRDSize if additional storage follows this object) mDNSu16 padding; // So that data is aligned on 32-bit boundary mDNSu8 data[InlineCacheRDSize]; } RData_small; // Note: Within an mDNSRecordCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Exit(), mDNS_Execute() typedef void mDNSRecordCallback (mDNS *const m, AuthRecord *const rr, mStatus result); // Note: // Restrictions: An mDNSRecordUpdateCallback may not make any mDNS API calls. // The intent of this callback is to allow the client to free memory, if necessary. // The internal data structures of the mDNS code may not be in a state where mDNS API calls may be made safely. typedef void mDNSRecordUpdateCallback (mDNS *const m, AuthRecord *const rr, RData *OldRData, mDNSu16 OldRDLen); // *************************************************************************** #if 0 #pragma mark - #pragma mark - NAT Traversal structures and constants #endif #define NATMAP_MAX_RETRY_INTERVAL ((mDNSPlatformOneSecond * 60) * 15) // Max retry interval is 15 minutes #define NATMAP_MIN_RETRY_INTERVAL (mDNSPlatformOneSecond * 2) // Min retry interval is 2 seconds #define NATMAP_INIT_RETRY (mDNSPlatformOneSecond / 4) // start at 250ms w/ exponential decay #define NATMAP_DEFAULT_LEASE (60 * 60 * 2) // 2 hour lease life in seconds #define NATMAP_VERS 0 typedef enum { NATOp_AddrRequest = 0, NATOp_MapUDP = 1, NATOp_MapTCP = 2, NATOp_AddrResponse = 0x80 | 0, NATOp_MapUDPResponse = 0x80 | 1, NATOp_MapTCPResponse = 0x80 | 2, } NATOp_t; enum { NATErr_None = 0, NATErr_Vers = 1, NATErr_Refused = 2, NATErr_NetFail = 3, NATErr_Res = 4, NATErr_Opcode = 5 }; typedef mDNSu16 NATErr_t; typedef packedstruct { mDNSu8 vers; mDNSu8 opcode; } NATAddrRequest; typedef packedstruct { mDNSu8 vers; mDNSu8 opcode; mDNSu16 err; mDNSu32 upseconds; // Time since last NAT engine reboot, in seconds mDNSv4Addr ExtAddr; } NATAddrReply; typedef packedstruct { mDNSu8 vers; mDNSu8 opcode; mDNSOpaque16 unused; mDNSIPPort intport; mDNSIPPort extport; mDNSu32 NATReq_lease; } NATPortMapRequest; typedef packedstruct { mDNSu8 vers; mDNSu8 opcode; mDNSu16 err; mDNSu32 upseconds; // Time since last NAT engine reboot, in seconds mDNSIPPort intport; mDNSIPPort extport; mDNSu32 NATRep_lease; } NATPortMapReply; // PCP Support for IPv4 mappings #define PCP_VERS 0x02 #define PCP_WAITSECS_AFTER_EPOCH_INVALID 5 typedef enum { PCPOp_Announce = 0, PCPOp_Map = 1 } PCPOp_t; typedef enum { PCPProto_All = 0, PCPProto_TCP = 6, PCPProto_UDP = 17 } PCPProto_t; typedef enum { PCPResult_Success = 0, PCPResult_UnsuppVersion = 1, PCPResult_NotAuthorized = 2, PCPResult_MalformedReq = 3, PCPResult_UnsuppOpcode = 4, PCPResult_UnsuppOption = 5, PCPResult_MalformedOption = 6, PCPResult_NetworkFailure = 7, PCPResult_NoResources = 8, PCPResult_UnsuppProtocol = 9, PCPResult_UserExQuota = 10, PCPResult_CantProvideExt = 11, PCPResult_AddrMismatch = 12, PCPResult_ExcesRemotePeer = 13 } PCPResult_t; typedef struct { mDNSu8 version; mDNSu8 opCode; mDNSOpaque16 reserved; mDNSu32 lifetime; mDNSv6Addr clientAddr; mDNSu32 nonce[3]; mDNSu8 protocol; mDNSu8 reservedMapOp[3]; mDNSIPPort intPort; mDNSIPPort extPort; mDNSv6Addr extAddress; } PCPMapRequest; typedef struct { mDNSu8 version; mDNSu8 opCode; mDNSu8 reserved; mDNSu8 result; mDNSu32 lifetime; mDNSu32 epoch; mDNSu32 clientAddrParts[3]; mDNSu32 nonce[3]; mDNSu8 protocol; mDNSu8 reservedMapOp[3]; mDNSIPPort intPort; mDNSIPPort extPort; mDNSv6Addr extAddress; } PCPMapReply; // LNT Support typedef enum { LNTDiscoveryOp = 1, LNTExternalAddrOp = 2, LNTPortMapOp = 3, LNTPortMapDeleteOp = 4 } LNTOp_t; #define LNT_MAXBUFSIZE 8192 typedef struct tcpLNTInfo_struct tcpLNTInfo; struct tcpLNTInfo_struct { tcpLNTInfo *next; mDNS *m; NATTraversalInfo *parentNATInfo; // pointer back to the parent NATTraversalInfo TCPSocket *sock; LNTOp_t op; // operation performed using this connection mDNSAddr Address; // router address mDNSIPPort Port; // router port mDNSu8 *Request; // xml request to router int requestLen; mDNSu8 *Reply; // xml reply from router int replyLen; unsigned long nread; // number of bytes read so far int retries; // number of times we've tried to do this port mapping }; typedef void (*NATTraversalClientCallback)(mDNS *m, NATTraversalInfo *n); // if m->timenow < ExpiryTime then we have an active mapping, and we'll renew halfway to expiry // if m->timenow >= ExpiryTime then our mapping has expired, and we're trying to create one typedef enum { NATTProtocolNone = 0, NATTProtocolNATPMP = 1, NATTProtocolUPNPIGD = 2, NATTProtocolPCP = 3, } NATTProtocol; struct NATTraversalInfo_struct { // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. NATTraversalInfo *next; mDNSs32 ExpiryTime; // Time this mapping expires, or zero if no mapping mDNSs32 retryInterval; // Current interval, between last packet we sent and the next one mDNSs32 retryPortMap; // If Protocol is nonzero, time to send our next mapping packet mStatus NewResult; // New error code; will be copied to Result just prior to invoking callback NATTProtocol lastSuccessfulProtocol; // To send correct deletion request & update non-PCP external address operations mDNSBool sentNATPMP; // Whether we just sent a NAT-PMP packet, so we won't send another if // we receive another NAT-PMP "Unsupported Version" packet #ifdef _LEGACY_NAT_TRAVERSAL_ tcpLNTInfo tcpInfo; // Legacy NAT traversal (UPnP) TCP connection #endif // Result fields: When the callback is invoked these fields contain the answers the client is looking for // When the callback is invoked ExternalPort is *usually* set to be the same the same as RequestedPort, except: // (a) When we're behind a NAT gateway with port mapping disabled, ExternalPort is reported as zero to // indicate that we don't currently have a working mapping (but RequestedPort retains the external port // we'd like to get, the next time we meet an accomodating NAT gateway willing to give us one). // (b) When we have a routable non-RFC1918 address, we don't *need* a port mapping, so ExternalPort // is reported as the same as our InternalPort, since that is effectively our externally-visible port too. // Again, RequestedPort retains the external port we'd like to get the next time we find ourself behind a NAT gateway. // To improve stability of port mappings, RequestedPort is updated any time we get a successful // mapping response from the PCP, NAT-PMP or UPnP gateway. For example, if we ask for port 80, and // get assigned port 81, then thereafter we'll contine asking for port 81. mDNSInterfaceID InterfaceID; mDNSv4Addr ExternalAddress; // Initially set to onesIPv4Addr, until first callback mDNSv4Addr NewAddress; // May be updated with actual value assigned by gateway mDNSIPPort ExternalPort; mDNSu32 Lifetime; mStatus Result; // Client API fields: The client must set up these fields *before* making any NAT traversal API calls mDNSu8 Protocol; // NATOp_MapUDP or NATOp_MapTCP, or zero if just requesting the external IP address mDNSIPPort IntPort; // Client's internal port number (doesn't change) mDNSIPPort RequestedPort; // Requested external port; may be updated with actual value assigned by gateway mDNSu32 NATLease; // Requested lifetime in seconds (doesn't change) NATTraversalClientCallback clientCallback; void *clientContext; }; // *************************************************************************** #if 0 #pragma mark - #pragma mark - DNSServer & McastResolver structures and constants #endif enum { McastResolver_FlagDelete = 1, McastResolver_FlagNew = 2 }; typedef struct McastResolver { struct McastResolver *next; mDNSInterfaceID interface; mDNSu32 flags; // Set when we're planning to delete this from the list domainname domain; mDNSu32 timeout; // timeout value for questions } McastResolver; enum { Mortality_Mortal = 0, // This cache record can expire and get purged Mortality_Immortal = 1, // Allow this record to remain in the cache indefinitely Mortality_Ghost = 2 // An immortal record that has expired and can linger in the cache }; typedef mDNSu8 MortalityState; // ScopeType values for DNSServer matching typedef enum { kScopeNone = 0, // DNS server used by unscoped questions kScopeInterfaceID = 1, // Scoped DNS server used only by scoped questions kScopeServiceID = 2 // Service specific DNS server used only by questions // have a matching serviceID } ScopeType; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) typedef mDNSu32 DNSServerFlags; #define DNSServerFlag_Delete (1U << 0) #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) #define DNSServerFlag_Unreachable (1U << 1) #endif typedef struct DNSServer { struct DNSServer *next; mDNSInterfaceID interface; // DNS requests should be sent on this interface mDNSs32 serviceID; // ServiceID from DNS configuration. mDNSAddr addr; // DNS server's IP address. DNSServerFlags flags; // Set when we're planning to delete this from the list. mDNSs32 penaltyTime; // amount of time this server is penalized ScopeType scopeType; // See the ScopeType enum above mDNSu32 timeout; // timeout value for questions mDNSu32 resGroupID; // ID of the resolver group that contains this DNSServer mDNSIPPort port; // DNS server's port number. mDNSBool usableA; // True if A query results are usable over the interface, i.e., interface has IPv4. mDNSBool usableAAAA; // True if AAAA query results are usable over the interface, i.e., interface has IPv6. mDNSBool isCell; // True if the interface to this server is cellular. mDNSBool isExpensive; // True if the interface to this server is expensive. mDNSBool isConstrained; // True if the interface to this server is constrained. mDNSBool isCLAT46; // True if the interface to this server supports CLAT46. domainname domain; // name->server matching for "split dns" } DNSServer; #endif #define kNegativeRecordType_Unspecified 0 // Initializer of ResourceRecord didn't specify why the record is negative. #define kNegativeRecordType_NoData 1 // The record's name exists, but there are no records of this type. struct ResourceRecord_struct { mDNSu8 RecordType; // See kDNSRecordTypes enum. mDNSu8 negativeRecordType; // If RecordType is kDNSRecordTypePacketNegative, specifies type of negative record. MortalityState mortality; // Mortality of this resource record (See MortalityState enum) mDNSu16 rrtype; // See DNS_TypeValues enum. mDNSu16 rrclass; // See DNS_ClassValues enum. mDNSu32 rroriginalttl; // In seconds mDNSu16 rdlength; // Size of the raw rdata, in bytes, in the on-the-wire format // (In-memory storage may be larger, for structures containing 'holes', like SOA) mDNSu16 rdestimate; // Upper bound on on-the-wire size of rdata after name compression mDNSu32 namehash; // Name-based (i.e. case-insensitive) hash of name mDNSu32 rdatahash; // For rdata containing domain name (e.g. PTR, SRV, CNAME etc.), case-insensitive name hash // else, for all other rdata, 32-bit hash of the raw rdata // Note: This requirement is important. Various routines like AddAdditionalsToResponseList(), // ReconfirmAntecedents(), etc., use rdatahash as a pre-flight check to see // whether it's worth doing a full SameDomainName() call. If the rdatahash // is not a correct case-insensitive name hash, they'll get false negatives. // Grouping pointers together at the end of the structure improves the memory layout efficiency mDNSInterfaceID InterfaceID; // Set if this RR is specific to one interface // For records received off the wire, InterfaceID is *always* set to the receiving interface // For our authoritative records, InterfaceID is usually zero, except for those few records // that are interface-specific (e.g. address records, especially linklocal addresses) const domainname *name; RData *rdata; // Pointer to storage for this rdata #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_dns_service_t dnsservice; mdns_resolver_type_t protocol; #else DNSServer *rDNSServer; // Unicast DNS server authoritative for this entry; null for multicast #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) dnssec_result_t dnssec_result; // DNSSEC validation result of the current resource record. // For all DNSSEC-disabled queries, the result would always be dnssec_indeterminate. // For DNSSEC-enabled queries, the result would be dnssec_indeterminate, // dnssec_secure, dnssec_insecure, or dnssec_bogus, see // for the detailed meaning of // each state. #endif }; // Unless otherwise noted, states may apply to either independent record registrations or service registrations typedef enum { regState_Zero = 0, regState_Pending = 1, // update sent, reply not received regState_Registered = 2, // update sent, reply received regState_DeregPending = 3, // dereg sent, reply not received regState_Unregistered = 4, // not in any list regState_Refresh = 5, // outstanding refresh (or target change) message regState_NATMap = 6, // establishing NAT port mapping regState_UpdatePending = 7, // update in flight as result of mDNS_Update call regState_NoTarget = 8, // SRV Record registration pending registration of hostname regState_NATError = 9 // unable to complete NAT traversal } regState_t; enum { Target_Manual = 0, Target_AutoHost = 1, Target_AutoHostAndNATMAP = 2 }; typedef enum { mergeState_Zero = 0, mergeState_DontMerge = 1 // Set on fatal error conditions to disable merging } mergeState_t; #define AUTH_GROUP_NAME_SIZE 128 struct AuthGroup_struct // Header object for a list of AuthRecords with the same name { AuthGroup *next; // Next AuthGroup object in this hash table bucket mDNSu32 namehash; // Name-based (i.e. case insensitive) hash of name AuthRecord *members; // List of CacheRecords with this same name AuthRecord **rrauth_tail; // Tail end of that list domainname *name; // Common name for all AuthRecords in this list AuthRecord *NewLocalOnlyRecords; mDNSu8 namestorage[AUTH_GROUP_NAME_SIZE]; }; #ifndef AUTH_HASH_SLOTS #define AUTH_HASH_SLOTS 499 #endif #define FORALL_AUTHRECORDS(SLOT,AG,AR) \ for ((SLOT) = 0; (SLOT) < AUTH_HASH_SLOTS; (SLOT)++) \ for ((AG)=m->rrauth.rrauth_hash[(SLOT)]; (AG); (AG)=(AG)->next) \ for ((AR) = (AG)->members; (AR); (AR)=(AR)->next) typedef union AuthEntity_union AuthEntity; union AuthEntity_union { AuthEntity *next; AuthGroup ag; }; typedef struct { mDNSu32 rrauth_size; // Total number of available auth entries mDNSu32 rrauth_totalused; // Number of auth entries currently occupied mDNSu32 rrauth_report; mDNSu8 rrauth_lock; // For debugging: Set at times when these lists may not be modified AuthEntity *rrauth_free; AuthGroup *rrauth_hash[AUTH_HASH_SLOTS]; }AuthHash; // AuthRecordAny includes mDNSInterface_Any and interface specific auth records. typedef enum { AuthRecordAny, // registered for *Any, NOT including P2P interfaces AuthRecordAnyIncludeP2P, // registered for *Any, including P2P interfaces AuthRecordAnyIncludeAWDL, // registered for *Any, including AWDL interface AuthRecordAnyIncludeAWDLandP2P, // registered for *Any, including AWDL and P2P interfaces AuthRecordLocalOnly, AuthRecordP2P, // discovered over D2D/P2P framework } AuthRecType; #define AuthRecordIncludesAWDL(AR) \ (((AR)->ARType == AuthRecordAnyIncludeAWDL) || ((AR)->ARType == AuthRecordAnyIncludeAWDLandP2P)) typedef enum { AuthFlagsWakeOnly = 0x1 // WakeOnly service } AuthRecordFlags; struct AuthRecord_struct { // For examples of how to set up this structure for use in mDNS_Register(), // see mDNS_AdvertiseInterface() or mDNS_RegisterService(). // Basically, resrec and persistent metadata need to be set up before calling mDNS_Register(). // mDNS_SetupResourceRecord() is avaliable as a helper routine to set up most fields to sensible default values for you AuthRecord *next; // Next in list; first element of structure for efficiency reasons // Field Group 1: Common ResourceRecord fields ResourceRecord resrec; // 36 bytes when compiling for 32-bit; 48 when compiling for 64-bit (now 44/64) // Field Group 2: Persistent metadata for Authoritative Records AuthRecord *Additional1; // Recommended additional record to include in response (e.g. SRV for PTR record) AuthRecord *Additional2; // Another additional (e.g. TXT for PTR record) AuthRecord *DependentOn; // This record depends on another for its uniqueness checking AuthRecord *RRSet; // This unique record is part of an RRSet mDNSRecordCallback *RecordCallback; // Callback function to call for state changes, and to free memory asynchronously on deregistration void *RecordContext; // Context parameter for the callback function mDNSu8 AutoTarget; // Set if the target of this record (PTR, CNAME, SRV, etc.) is our host name mDNSu8 AllowRemoteQuery; // Set if we allow hosts not on the local link to query this record mDNSu8 ForceMCast; // Set by client to advertise solely via multicast, even for apparently unicast names mDNSu8 AuthFlags; OwnerOptData WakeUp; // WakeUp.HMAC.l[0] nonzero indicates that this is a Sleep Proxy record mDNSAddr AddressProxy; // For reverse-mapping Sleep Proxy PTR records, address in question mDNSs32 TimeRcvd; // In platform time units mDNSs32 TimeExpire; // In platform time units AuthRecType ARType; // LocalOnly, P2P or Normal ? mDNSs32 KATimeExpire; // In platform time units: time to send keepalive packet for the proxy record // Field Group 3: Transient state for Authoritative Records mDNSs32 ProbingConflictCount; // Number of conflicting records observed during probing. mDNSs32 LastConflictPktNum; // Number of the last received packet that caused a probing conflict. mDNSu8 Acknowledged; // Set if we've given the success callback to the client mDNSu8 ProbeRestartCount; // Number of times we have restarted probing mDNSu8 ProbeCount; // Number of probes remaining before this record is valid (kDNSRecordTypeUnique) mDNSu8 AnnounceCount; // Number of announcements remaining (kDNSRecordTypeShared) mDNSu8 RequireGoodbye; // Set if this RR has been announced on the wire and will require a goodbye packet mDNSu8 AnsweredLocalQ; // Set if this AuthRecord has been delivered to any local question (LocalOnly or mDNSInterface_Any) mDNSu8 IncludeInProbe; // Set if this RR is being put into a probe right now mDNSu8 ImmedUnicast; // Set if we may send our response directly via unicast to the requester mDNSInterfaceID SendNSECNow; // Set if we need to generate associated NSEC data for this rrname mDNSInterfaceID ImmedAnswer; // Someone on this interface issued a query we need to answer (all-ones for all interfaces) #if MDNS_LOG_ANSWER_SUPPRESSION_TIMES mDNSs32 ImmedAnswerMarkTime; #endif mDNSInterfaceID ImmedAdditional; // Hint that we might want to also send this record, just to be helpful mDNSInterfaceID SendRNow; // The interface this query is being sent on right now mDNSv4Addr v4Requester; // Recent v4 query for this record, or all-ones if more than one recent query mDNSv6Addr v6Requester; // Recent v6 query for this record, or all-ones if more than one recent query AuthRecord *NextResponse; // Link to the next element in the chain of responses to generate const mDNSu8 *NR_AnswerTo; // Set if this record was selected by virtue of being a direct answer to a question AuthRecord *NR_AdditionalTo; // Set if this record was selected by virtue of being additional to another mDNSs32 ThisAPInterval; // In platform time units: Current interval for announce/probe mDNSs32 LastAPTime; // In platform time units: Last time we sent announcement/probe mDNSs32 LastMCTime; // Last time we multicast this record (used to guard against packet-storm attacks) mDNSInterfaceID LastMCInterface; // Interface this record was multicast on at the time LastMCTime was recorded RData *NewRData; // Set if we are updating this record with new rdata mDNSu16 newrdlength; // ... and the length of the new RData mDNSRecordUpdateCallback *UpdateCallback; mDNSu32 UpdateCredits; // Token-bucket rate limiting of excessive updates mDNSs32 NextUpdateCredit; // Time next token is added to bucket mDNSs32 UpdateBlocked; // Set if update delaying is in effect // Field Group 4: Transient uDNS state for Authoritative Records regState_t state; // Maybe combine this with resrec.RecordType state? Right now it's ambiguous and confusing. // e.g. rr->resrec.RecordType can be kDNSRecordTypeUnregistered, // and rr->state can be regState_Unregistered // What if we find one of those statements is true and the other false? What does that mean? mDNSBool uselease; // dynamic update contains (should contain) lease option mDNSs32 expire; // In platform time units: expiration of lease (-1 for static) mDNSBool Private; // If zone is private, DNS updates may have to be encrypted to prevent eavesdropping mDNSOpaque16 updateid; // Identifier to match update request and response -- also used when transferring records to Sleep Proxy mDNSOpaque64 updateIntID; // Interface IDs (one bit per interface index)to which updates have been sent const domainname *zone; // the zone that is updated ZoneData *nta; struct tcpInfo_t *tcp; NATTraversalInfo NATinfo; mDNSBool SRVChanged; // temporarily deregistered service because its SRV target or port changed mergeState_t mState; // Unicast Record Registrations merge state mDNSu8 refreshCount; // Number of refreshes to the server mStatus updateError; // Record update resulted in Error ? // uDNS_UpdateRecord support fields // Do we really need all these in *addition* to NewRData and newrdlength above? void *UpdateContext; // Context parameter for the update callback function mDNSu16 OrigRDLen; // previously registered, being deleted mDNSu16 InFlightRDLen; // currently being registered mDNSu16 QueuedRDLen; // pending operation (re-transmitting if necessary) THEN register the queued update RData *OrigRData; RData *InFlightRData; RData *QueuedRData; // Field Group 5: Large data objects go at the end domainname namestorage; RData rdatastorage; // Normally the storage is right here, except for oversized records // rdatastorage MUST be the last thing in the structure -- when using oversized AuthRecords, extra bytes // are appended after the end of the AuthRecord, logically augmenting the size of the rdatastorage // DO NOT ADD ANY MORE FIELDS HERE }; // IsLocalDomain alone is not sufficient to determine that a record is mDNS or uDNS. By default domain names within // the "local" pseudo-TLD (and within the IPv4 and IPv6 link-local reverse mapping domains) are automatically treated // as mDNS records, but it is also possible to force any record (even those not within one of the inherently local // domains) to be handled as an mDNS record by setting the ForceMCast flag, or by setting a non-zero InterfaceID. // For example, the reverse-mapping PTR record created in AdvertiseInterface sets the ForceMCast flag, since it points to // a dot-local hostname, and therefore it would make no sense to register this record with a wide-area Unicast DNS server. // The same applies to Sleep Proxy records, which we will answer for when queried via mDNS, but we never want to try // to register them with a wide-area Unicast DNS server -- and we probably don't have the required credentials anyway. // Currently we have no concept of a wide-area uDNS record scoped to a particular interface, so if the InterfaceID is // nonzero we treat this the same as ForceMCast. // Note: Question_uDNS(Q) is used in *only* one place -- on entry to mDNS_StartQuery_internal, to decide whether to set TargetQID. // Everywhere else in the code, the determination of whether a question is unicast is made by checking to see if TargetQID is nonzero. #define AuthRecord_uDNS(R) ((R)->resrec.InterfaceID == mDNSInterface_Any && !(R)->ForceMCast && !IsLocalDomain((R)->resrec.name)) #define Question_uDNS(Q) ((Q)->IsUnicastDotLocal || (Q)->ProxyQuestion || \ ((Q)->InterfaceID != mDNSInterface_LocalOnly && (Q)->InterfaceID != mDNSInterface_P2P && (Q)->InterfaceID != mDNSInterface_BLE && !(Q)->ForceMCast && !IsLocalDomain(&(Q)->qname))) // AuthRecordLocalOnly records are registered using mDNSInterface_LocalOnly and // AuthRecordP2P records are created by D2DServiceFound events. Both record types are kept on the same list. #define RRLocalOnly(rr) ((rr)->ARType == AuthRecordLocalOnly || (rr)->ARType == AuthRecordP2P) // All other auth records, not including those defined as RRLocalOnly(). #define RRAny(rr) ((rr)->ARType == AuthRecordAny || (rr)->ARType == AuthRecordAnyIncludeP2P || (rr)->ARType == AuthRecordAnyIncludeAWDL || (rr)->ARType == AuthRecordAnyIncludeAWDLandP2P) // Normally we always lookup the cache and /etc/hosts before sending the query on the wire. For single label // queries (A and AAAA) that are unqualified (indicated by AppendSearchDomains), we want to append search // domains before we try them as such #define ApplySearchDomainsFirst(q) ((q)->AppendSearchDomains && (CountLabels(&((q)->qname))) == 1) // Wrapper struct for Auth Records for higher-level code that cannot use the AuthRecord's ->next pointer field typedef struct ARListElem { struct ARListElem *next; AuthRecord ar; // Note: Must be last element of structure, to accomodate oversized AuthRecords } ARListElem; struct CacheRecord_struct { CacheRecord *next; // Next in list; first element of structure for efficiency reasons ResourceRecord resrec; // 36 bytes when compiling for 32-bit; 48 when compiling for 64-bit (now 44/64) // Transient state for Cache Records CacheRecord *NextInKAList; // Link to the next element in the chain of known answers to send mDNSs32 TimeRcvd; // In platform time units mDNSs32 DelayDelivery; // Set if we want to defer delivery of this answer to local clients mDNSs32 NextRequiredQuery; // In platform time units #if MDNSRESPONDER_SUPPORTS(APPLE, CACHE_ANALYTICS) mDNSs32 LastCachedAnswerTime; // Last time this record was used as an answer from the cache (before a query) // In platform time units #else // Extra four bytes here (on 64bit) #endif DNSQuestion *CRActiveQuestion; // Points to an active question referencing this answer. Can never point to a NewQuestion. mDNSs32 LastUnansweredTime; // In platform time units; last time we incremented UnansweredQueries mDNSu8 UnansweredQueries; // Number of times we've issued a query for this record without getting an answer mDNSOpaque16 responseFlags; // Second 16 bit in the DNS response CacheRecord *NextInCFList; // Set if this is in the list of records we just received with the cache flush bit set CacheRecord *soa; // SOA record to return for proxy questions #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) void *denial_of_existence_records; // denial_of_existence_records_t #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) mDNSAddr sourceAddress; // node from which we received this record // Size to here is 76 bytes when compiling 32-bit; 104 bytes when compiling 64-bit (now 160 bytes for 64-bit) RData_small smallrdatastorage; // Storage for small records is right here (4 bytes header + 68 bytes data = 72 bytes) }; // Should match the CacheGroup_struct members, except namestorage[]. Only used to calculate // the size of the namestorage array in CacheGroup_struct so that sizeof(CacheGroup) == sizeof(CacheRecord) struct CacheGroup_base { CacheGroup *next; mDNSu32 namehash; CacheRecord *members; CacheRecord **rrcache_tail; domainname *name; }; struct CacheGroup_struct // Header object for a list of CacheRecords with the same name { CacheGroup *next; // Next CacheGroup object in this hash table bucket mDNSu32 namehash; // Name-based (i.e. case insensitive) hash of name CacheRecord *members; // List of CacheRecords with this same name CacheRecord **rrcache_tail; // Tail end of that list domainname *name; // Common name for all CacheRecords in this list mDNSu8 namestorage[sizeof(CacheRecord) - sizeof(struct CacheGroup_base)]; // match sizeof(CacheRecord) }; // Storage sufficient to hold either a CacheGroup header or a CacheRecord // -- for best efficiency (to avoid wasted unused storage) they should be the same size typedef union CacheEntity_union CacheEntity; union CacheEntity_union { CacheEntity *next; CacheGroup cg; CacheRecord cr; }; typedef struct { CacheRecord r; mDNSu8 _extradata[MaximumRDSize-InlineCacheRDSize]; // Glue on the necessary number of extra bytes domainname namestorage; // Needs to go *after* the extra rdata bytes } LargeCacheRecord; typedef struct HostnameInfo { struct HostnameInfo *next; NATTraversalInfo natinfo; domainname fqdn; AuthRecord arv4; // registered IPv4 address record AuthRecord arv6; // registered IPv6 address record mDNSRecordCallback *StatusCallback; // callback to deliver success or error code to client layer const void *StatusContext; // Client Context } HostnameInfo; typedef struct ExtraResourceRecord_struct ExtraResourceRecord; struct ExtraResourceRecord_struct { ExtraResourceRecord *next; mDNSu32 ClientID; // Opaque ID field to be used by client to map an AddRecord call to a set of Extra records AuthRecord r; // Note: Add any additional fields *before* the AuthRecord in this structure, not at the end. // In some cases clients can allocate larger chunks of memory and set r->rdata->MaxRDLength to indicate // that this extra memory is available, which would result in any fields after the AuthRecord getting smashed }; // Note: Within an mDNSServiceCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Exit(), mDNS_Execute() typedef void mDNSServiceCallback (mDNS *const m, ServiceRecordSet *const sr, mStatus result); // A ServiceRecordSet has no special meaning to the core code of the Multicast DNS protocol engine; // it is just a convenience structure to group together the records that make up a standard service // registration so that they can be allocted and deallocted together as a single memory object. // It contains its own ServiceCallback+ServiceContext to report aggregate results up to the next layer of software above. // It also contains: // * the basic PTR/SRV/TXT triplet used to represent any DNS-SD service // * the "_services" PTR record for service enumeration // * the optional list of SubType PTR records // * the optional list of additional records attached to the service set (e.g. iChat pictures) struct ServiceRecordSet_struct { // These internal state fields are used internally by mDNSCore; the client layer needn't be concerned with them. // No fields need to be set up by the client prior to calling mDNS_RegisterService(); // all required data is passed as parameters to that function. mDNSServiceCallback *ServiceCallback; void *ServiceContext; mDNSBool Conflict; // Set if this record set was forcibly deregistered because of a conflict ExtraResourceRecord *Extras; // Optional list of extra AuthRecords attached to this service registration mDNSu32 NumSubTypes; AuthRecord *SubTypes; mDNSu32 flags; // saved for subsequent calls to mDNS_RegisterService() if records // need to be re-registered. AuthRecord RR_ADV; // e.g. _services._dns-sd._udp.local. PTR _printer._tcp.local. AuthRecord RR_PTR; // e.g. _printer._tcp.local. PTR Name._printer._tcp.local. AuthRecord RR_SRV; // e.g. Name._printer._tcp.local. SRV 0 0 port target AuthRecord RR_TXT; // e.g. Name._printer._tcp.local. TXT PrintQueueName // Don't add any fields after AuthRecord RR_TXT. // This is where the implicit extra space goes if we allocate a ServiceRecordSet containing an oversized RR_TXT record }; // *************************************************************************** #if 0 #pragma mark - #pragma mark - Question structures #endif // We record the last eight instances of each duplicate query // This gives us v4/v6 on each of Ethernet, AirPort and Firewire, and two free slots "for future expansion" // If the host has more active interfaces that this it is not fatal -- duplicate question suppression will degrade gracefully. // Since we will still remember the last eight, the busiest interfaces will still get the effective duplicate question suppression. #define DupSuppressInfoSize 8 typedef struct { mDNSs32 Time; mDNSInterfaceID InterfaceID; mDNSs32 Type; // v4 or v6? } DupSuppressInfo; typedef enum { // This is the initial state. LLQ_Init = 1, // All of these states indicate that we are doing DNS Push, and haven't given up yet. LLQ_DNSPush_ServerDiscovery = 100, LLQ_DNSPush_Connecting = 101, LLQ_DNSPush_Established = 102, // All of these states indicate that we are doing LLQ and haven't given up yet. LLQ_InitialRequest = 200, LLQ_SecondaryRequest = 201, LLQ_Established = 202, // If we get here, it means DNS Push isn't available, so we're polling. LLQ_Poll = 300 } LLQ_State; // LLQ constants #define kLLQ_Vers 1 #define kLLQ_DefLease 7200 // 2 hours #define kLLQ_MAX_TRIES 3 // retry an operation 3 times max #define kLLQ_INIT_RESEND 2 // resend an un-ack'd packet after 2 seconds, then double for each additional // LLQ Operation Codes #define kLLQOp_Setup 1 #define kLLQOp_Refresh 2 #define kLLQOp_Event 3 // LLQ Errror Codes enum { LLQErr_NoError = 0, LLQErr_ServFull = 1, LLQErr_Static = 2, LLQErr_FormErr = 3, LLQErr_NoSuchLLQ = 4, LLQErr_BadVers = 5, LLQErr_UnknownErr = 6 }; enum { NoAnswer_Normal = 0, NoAnswer_Suspended = 1, NoAnswer_Fail = 2 }; typedef enum { DNSPushServerDisconnected, DNSPushServerConnectFailed, DNSPushServerConnectionInProgress, DNSPushServerConnected, DNSPushServerSessionEstablished, DNSPushServerNoDNSPush } DNSPushServer_ConnectState; enum { AllowExpired_None = 0, // Don't allow expired answers or mark answers immortal (behave normally) AllowExpired_MakeAnswersImmortal = 1, // Any answers to this question get marked as immortal AllowExpired_AllowExpiredAnswers = 2 // Allow already expired answers from the cache }; typedef mDNSu8 AllowExpiredState; #define HMAC_LEN 64 #define HMAC_IPAD 0x36 #define HMAC_OPAD 0x5c #define MD5_LEN 16 // Internal data structure to maintain authentication information typedef struct DomainAuthInfo { struct DomainAuthInfo *next; mDNSs32 deltime; // If we're planning to delete this DomainAuthInfo, the time we want it deleted domainname domain; domainname keyname; domainname hostname; mDNSIPPort port; char b64keydata[32]; mDNSu8 keydata_ipad[HMAC_LEN]; // padded key for inner hash rounds mDNSu8 keydata_opad[HMAC_LEN]; // padded key for outer hash rounds } DomainAuthInfo; // Note: Within an mDNSQuestionCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Exit(), mDNS_Execute() // Note: Any value other than QC_rmv i.e., any non-zero value will result in kDNSServiceFlagsAdd to the application // layer. These values are used within mDNSResponder and not sent across to the application. QC_addnocache is for // delivering a response without adding to the cache. QC_forceresponse is superset of QC_addnocache where in // addition to not entering in the cache, it also forces the negative response through. typedef enum { QC_rmv = 0, QC_add, QC_addnocache, QC_forceresponse, QC_suppressed } QC_result; typedef void mDNSQuestionCallback (mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord); typedef void (*mDNSQuestionResetHandler)(DNSQuestion *question); typedef void AsyncDispatchFunc(mDNS *const m, void *context); extern void mDNSPlatformDispatchAsync(mDNS *const m, void *context, AsyncDispatchFunc func); #define NextQSendTime(Q) ((Q)->LastQTime + (Q)->ThisQInterval) #define ActiveQuestion(Q) ((Q)->ThisQInterval > 0 && !(Q)->DuplicateOf) #define TimeToSendThisQuestion(Q,time) (ActiveQuestion(Q) && (time) - NextQSendTime(Q) >= 0) #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #define FollowCNAMEOptionDNSSEC(Q) !(Q)->DNSSECStatus.enable_dnssec #else // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #define FollowCNAMEOptionDNSSEC(Q) mDNStrue #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // Given the resource record and the question, should we follow the CNAME ? #define FollowCNAME(q, rr, AddRecord) (AddRecord && (q)->qtype != kDNSType_CNAME && \ (rr)->RecordType != kDNSRecordTypePacketNegative && \ (rr)->rrtype == kDNSType_CNAME \ && FollowCNAMEOptionDNSSEC(q)) // RFC 4122 defines it to be 16 bytes #define UUID_SIZE 16 #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) enum { ExpiredAnswer_None = 0, // No expired answers used ExpiredAnswer_Allowed = 1, // An expired answer is allowed by this request ExpiredAnswer_AnsweredWithCache = 2, // Question was answered with a cached answer ExpiredAnswer_AnsweredWithExpired = 3, // Question was answered with an expired answer ExpiredAnswer_ExpiredAnswerChanged = 4, // Expired answer changed on refresh ExpiredAnswer_EnumCount }; typedef mDNSu8 ExpiredAnswerMetric; enum { DNSOverTCP_None = 0, // DNS Over TCP not used DNSOverTCP_Truncated = 1, // DNS Over TCP used because UDP reply was truncated DNSOverTCP_Suspicious = 2, // DNS Over TCP used because we received a suspicious reply DNSOverTCP_SuspiciousDefense = 3, // DNS Over TCP used because we were within the timeframe of a previous suspicious response DNSOverTCP_EnumCount }; typedef mDNSu8 DNSOverTCPMetric; typedef struct { domainname * originalQName; // Name of original A/AAAA record if this question is for a CNAME record. mDNSu32 querySendCount; // Number of queries that have been sent to DNS servers so far. mDNSs32 firstQueryTime; // The time when the first query was sent to a DNS server. mDNSBool answered; // Has this question been answered? ExpiredAnswerMetric expiredAnswerState; // Expired answer state (see ExpiredAnswerMetric above) DNSOverTCPMetric dnsOverTCPState; // DNS Over TCP state (see DNSOverTCPMetric above) } uDNSMetrics; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) extern mDNSu32 curr_num_regservices; // tracks the current number of services registered extern mDNSu32 max_num_regservices; // tracks the max number of simultaneous services registered by the device #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) #include "DNS64State.h" #endif typedef struct mDNS_DNSPushNotificationServer DNSPushNotificationServer; typedef struct mDNS_DNSPushNotificationZone DNSPushNotificationZone; struct DNSQuestion_struct { // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. DNSQuestion *next; mDNSu32 qnamehash; mDNSs32 DelayAnswering; // Set if we want to defer answering this question until the cache settles mDNSs32 LastQTime; // Last scheduled transmission of this Q on *all* applicable interfaces mDNSs32 ThisQInterval; // LastQTime + ThisQInterval is the next scheduled transmission of this Q // ThisQInterval > 0 for an active question; // ThisQInterval = 0 for a suspended question that's still in the list // ThisQInterval = -1 for a cancelled question (should not still be in list) mDNSs32 ExpectUnicastResp; // Set when we send a query with the kDNSQClass_UnicastResponse bit set mDNSs32 LastAnswerPktNum; // The sequence number of the last response packet containing an answer to this Q mDNSu32 RecentAnswerPkts; // Number of answers since the last time we sent this query mDNSu32 CurrentAnswers; // Number of records currently in the cache that answer this question mDNSu32 BrowseThreshold; // If we have received at least this number of answers, // set the next question interval to MaxQuestionInterval mDNSu32 LargeAnswers; // Number of answers with rdata > 1024 bytes mDNSu32 UniqueAnswers; // Number of answers received with kDNSClass_UniqueRRSet bit set mDNSInterfaceID FlappingInterface1; // Set when an interface goes away, to flag if remove events are delivered for this Q mDNSInterfaceID FlappingInterface2; // Set when an interface goes away, to flag if remove events are delivered for this Q DomainAuthInfo *AuthInfo; // Non-NULL if query is currently being done using Private DNS DNSQuestion *DuplicateOf; DNSQuestion *NextInDQList; DupSuppressInfo DupSuppress[DupSuppressInfoSize]; mDNSInterfaceID SendQNow; // The interface this query is being sent on right now mDNSBool SendOnAll; // Set if we're sending this question on all active interfaces mDNSBool CachedAnswerNeedsUpdate; // See SendQueries(). Set if we're sending this question // because a cached answer needs to be refreshed. mDNSu32 RequestUnicast; // Non-zero if we want to send query with kDNSQClass_UnicastResponse bit set mDNSs32 LastQTxTime; // Last time this Q was sent on one (but not necessarily all) interfaces mDNSu32 CNAMEReferrals; // Count of how many CNAME redirections we've done mDNSBool Suppressed; // This query should be suppressed, i.e., not sent on the wire. mDNSu8 LOAddressAnswers; // Number of answers from the local only auth records that are // answering A, AAAA, CNAME, or PTR (/etc/hosts) mDNSu8 WakeOnResolveCount; // Number of wakes that should be sent on resolve mDNSBool InitialCacheMiss; // True after the question cannot be answered from the cache mDNSs32 StopTime; // Time this question should be stopped by giving them a negative answer // Wide Area fields. These are used internally by the uDNS core (Unicast) UDPSocket *LocalSocket; // |-> DNS Configuration related fields used in uDNS (Subset of Wide Area/Unicast fields) #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_dns_service_t dnsservice; // The current DNS service. mdns_dns_service_id_t lastDNSServiceID; // The ID of the previous DNS service before a CNAME restart. mdns_querier_t querier; // The current querier. #else DNSServer *qDNSServer; // Caching server for this query (in the absence of an SRV saying otherwise) mDNSOpaque128 validDNSServers; // Valid DNSServers for this question mDNSu16 noServerResponse; // At least one server did not respond. mDNSBool triedAllServersOnce; // True if all DNS servers have been tried once. mDNSu8 unansweredQueries; // The number of unanswered queries to this server #endif AllowExpiredState allowExpired; // Allow expired answers state (see enum AllowExpired_None, etc. above) ZoneData *nta; // Used for getting zone data for private or LLQ query mDNSAddr servAddr; // Address and port learned from _dns-llq, _dns-llq-tls or _dns-query-tls SRV query mDNSIPPort servPort; struct tcpInfo_t *tcp; mDNSIPPort tcpSrcPort; // Local Port TCP packet received on;need this as tcp struct is disposed // by tcpCallback before calling into mDNSCoreReceive mDNSu8 NoAnswer; // Set if we want to suppress answers until tunnel setup has completed #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool Restart; // This question should be restarted soon. #endif // LLQ-specific fields. These fields are only meaningful when LongLived flag is set LLQ_State state; mDNSu32 ReqLease; // seconds (relative) mDNSs32 expire; // ticks (absolute) mDNSs16 ntries; // for UDP: the number of packets sent for this LLQ state // for TCP: there is some ambiguity in the use of this variable, but in general, it is // the number of TCP/TLS connection attempts for this LLQ state, or // the number of packets sent for this TCP/TLS connection // DNS Push Notification fields. These fields are only meaningful when LongLived flag is set DNSPushNotificationServer *dnsPushServer; mDNSOpaque64 id; // DNS Proxy fields mDNSOpaque16 responseFlags; // Temporary place holder for the error we get back from the DNS server // till we populate in the cache mDNSBool BlockedByPolicy; // True if the question is blocked by policy rule evaluation. mDNSs32 ServiceID; // Service identifier to match against the DNS server #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSu8 ResolverUUID[UUID_SIZE]; // Resolver UUID to match against the DNS server mdns_dns_service_id_t CustomID; #endif // Client API fields: The client must set up these fields *before* calling mDNS_StartQuery() mDNSInterfaceID InterfaceID; // Non-zero if you want to issue queries only on a single specific IP interface mDNSu32 flags; // flags from original DNSService*() API request. mDNSOpaque16 TargetQID; // DNS or mDNS message ID. domainname qname; domainname firstExpiredQname; // first expired qname in request chain mDNSu16 qtype; mDNSu16 qclass; mDNSBool LongLived; // Set by client for calls to mDNS_StartQuery to indicate LLQs to unicast layer. mDNSBool ExpectUnique; // Set by client if it's expecting unique RR(s) for this question, not shared RRs mDNSBool ForceMCast; // Set by client to force mDNS query, even for apparently uDNS names mDNSBool ReturnIntermed; // Set by client to request callbacks for intermediate CNAME/NXDOMAIN results mDNSBool SuppressUnusable; // Set by client to suppress unusable queries to be sent on the wire mDNSBool TimeoutQuestion; // Timeout this question if there is no reply in configured time mDNSBool IsUnicastDotLocal; // True if this is a dot-local query that should be answered via unicast DNS. mDNSBool WakeOnResolve; // Send wakeup on resolve mDNSBool UseBackgroundTraffic; // Set by client to use background traffic class for request mDNSBool AppendSearchDomains; // Search domains can be appended for this query mDNSBool ForcePathEval; // Perform a path evaluation even if kDNSServiceFlagsPathEvaluationDone is set. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool RequireEncryption; // Set by client to require encrypted queries #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) mDNSBool inAppBrowserRequest; // Is request associated with an in-app-browser audit_token_t peerAuditToken; // audit token of the peer requesting the question audit_token_t delegateAuditToken; // audit token of the delegated client the question is for #endif mDNSu8 ProxyQuestion; // Proxy Question mDNSs32 pid; // Process ID of the client that is requesting the question mDNSu8 uuid[UUID_SIZE]; // Unique ID of the client that is requesting the question (valid only if pid is zero) mDNSu32 euid; // Effective User Id of the client that is requesting the question mDNSu32 request_id; // The ID of request that generates the current question mDNSQuestionCallback *QuestionCallback; mDNSQuestionResetHandler ResetHandler; void *QuestionContext; #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) uDNSMetrics metrics; // Data used for collecting unicast DNS query metrics. #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNS64) DNS64 dns64; // DNS64 state for performing IPv6 address synthesis on networks with NAT64. #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) dnssec_status_t DNSSECStatus; // DNSSEC state for fectching DNSSEC records and doing validation #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) }; typedef enum { ZoneServiceUpdate, ZoneServiceQuery, ZoneServiceLLQ, ZoneServiceDNSPush } ZoneService; typedef void ZoneDataCallback (mDNS *const m, mStatus err, const ZoneData *result); struct ZoneData_struct { domainname ChildName; // Name for which we're trying to find the responsible server ZoneService ZoneService; // Which service we're seeking for this zone (update, query, or LLQ) domainname *CurrentSOA; // Points to somewhere within ChildName domainname ZoneName; // Discovered result: Left-hand-side of SOA record mDNSu16 ZoneClass; // Discovered result: DNS Class from SOA record domainname Host; // Discovered result: Target host from SRV record mDNSIPPort Port; // Discovered result: Update port, query port, or LLQ port from SRV record mDNSAddr Addr; // Discovered result: Address of Target host from SRV record mDNSBool ZonePrivate; // Discovered result: Does zone require encrypted queries? ZoneDataCallback *ZoneDataCallback; // Caller-specified function to be called upon completion void *ZoneDataContext; DNSQuestion question; // Storage for any active question }; extern ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *callbackInfo); extern void CancelGetZoneData(mDNS *const m, ZoneData *nta); extern mDNSBool IsGetZoneDataQuestion(DNSQuestion *q); typedef struct DNameListElem { struct DNameListElem *next; mDNSu32 uid; domainname name; } DNameListElem; #if APPLE_OSX_mDNSResponder // Different states that we go through locating the peer #define TC_STATE_AAAA_PEER 0x000000001 /* Peer's BTMM IPv6 address */ #define TC_STATE_AAAA_PEER_RELAY 0x000000002 /* Peer's IPv6 Relay address */ #define TC_STATE_SRV_PEER 0x000000003 /* Peer's SRV Record corresponding to IPv4 address */ #define TC_STATE_ADDR_PEER 0x000000004 /* Peer's IPv4 address */ typedef struct ClientTunnel { struct ClientTunnel *next; domainname dstname; mDNSBool MarkedForDeletion; mDNSv6Addr loc_inner; mDNSv4Addr loc_outer; mDNSv6Addr loc_outer6; mDNSv6Addr rmt_inner; mDNSv4Addr rmt_outer; mDNSv6Addr rmt_outer6; mDNSIPPort rmt_outer_port; mDNSu16 tc_state; DNSQuestion q; } ClientTunnel; #endif // *************************************************************************** #if 0 #pragma mark - #pragma mark - NetworkInterfaceInfo_struct #endif typedef struct NetworkInterfaceInfo_struct NetworkInterfaceInfo; // A NetworkInterfaceInfo_struct serves two purposes: // 1. It holds the address, PTR and HINFO records to advertise a given IP address on a given physical interface // 2. It tells mDNSCore which physical interfaces are available; each physical interface has its own unique InterfaceID. // Since there may be multiple IP addresses on a single physical interface, // there may be multiple NetworkInterfaceInfo_structs with the same InterfaceID. // In this case, to avoid sending the same packet n times, when there's more than one // struct with the same InterfaceID, mDNSCore picks one member of the set to be the // active representative of the set; all others have the 'InterfaceActive' flag unset. struct NetworkInterfaceInfo_struct { // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them. NetworkInterfaceInfo *next; mDNSu8 InterfaceActive; // Set if interface is sending & receiving packets (see comment above) mDNSu8 IPv4Available; // If InterfaceActive, set if v4 available on this InterfaceID mDNSu8 IPv6Available; // If InterfaceActive, set if v6 available on this InterfaceID DNSQuestion NetWakeBrowse; DNSQuestion NetWakeResolve[3]; // For fault-tolerance, we try up to three Sleep Proxies mDNSAddr SPSAddr[3]; mDNSIPPort SPSPort[3]; mDNSs32 NextSPSAttempt; // -1 if we're not currently attempting to register with any Sleep Proxy mDNSs32 NextSPSAttemptTime; // Standard AuthRecords that every Responder host should have (one per active IP address) AuthRecord RR_A; // 'A' or 'AAAA' (address) record for our ".local" name AuthRecord RR_PTR; // PTR (reverse lookup) record #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) AuthRecord RR_AddrRand; // For non-AWDL interfaces, this is the A or AAAA record of the randomized hostname. #endif // Client API fields: The client must set up these fields *before* calling mDNS_RegisterInterface() mDNSInterfaceID InterfaceID; // Identifies physical interface; MUST NOT be 0, -1, or -2 mDNSAddr ip; // The IPv4 or IPv6 address to advertise mDNSAddr mask; mDNSEthAddr MAC; char ifname[64]; // Windows uses a GUID string for the interface name, which doesn't fit in 16 bytes mDNSu8 Advertise; // False if you are only searching on this interface mDNSu8 McastTxRx; // Send/Receive multicast on this { InterfaceID, address family } ? mDNSu8 NetWake; // Set if Wake-On-Magic-Packet is enabled on this interface mDNSu8 Loopback; // Set if this is the loopback interface mDNSu8 IgnoreIPv4LL; // Set if IPv4 Link-Local addresses have to be ignored. mDNSu8 SendGoodbyes; // Send goodbyes on this interface while sleeping mDNSBool DirectLink; // a direct link, indicating we can skip the probe for // address records mDNSBool SupportsUnicastMDNSResponse; // Indicates that the interface supports unicast responses // to Bonjour queries. Generally true for an interface. }; #define SLE_DELETE 0x00000001 #define SLE_WAB_BROWSE_QUERY_STARTED 0x00000002 #define SLE_WAB_LBROWSE_QUERY_STARTED 0x00000004 #define SLE_WAB_REG_QUERY_STARTED 0x00000008 typedef struct SearchListElem { struct SearchListElem *next; domainname domain; int flag; mDNSInterfaceID InterfaceID; DNSQuestion BrowseQ; DNSQuestion DefBrowseQ; DNSQuestion AutomaticBrowseQ; DNSQuestion RegisterQ; DNSQuestion DefRegisterQ; int numCfAnswers; ARListElem *AuthRecs; } SearchListElem; // For domain enumeration and automatic browsing // This is the user's DNS search list. // In each of these domains we search for our special pointer records (lb._dns-sd._udp., etc.) // to discover recommended domains for domain enumeration (browse, default browse, registration, // default registration) and possibly one or more recommended automatic browsing domains. extern SearchListElem *SearchList; // This really ought to be part of mDNS_struct -- SC // *************************************************************************** #if 0 #pragma mark - #pragma mark - Main mDNS object, used to hold all the mDNS state #endif typedef void mDNSCallback (mDNS *const m, mStatus result); #ifndef CACHE_HASH_SLOTS #define CACHE_HASH_SLOTS 499 #endif enum { SleepState_Awake = 0, SleepState_Transferring = 1, SleepState_Sleeping = 2 }; typedef struct { mDNSu32 NameConflicts; // Normal Name conflicts mDNSu32 KnownUniqueNameConflicts; // Name Conflicts for KnownUnique Records mDNSu32 DupQuerySuppressions; // Duplicate query suppressions mDNSu32 KnownAnswerSuppressions; // Known Answer suppressions mDNSu32 KnownAnswerMultiplePkts; // Known Answer in queries spannign multiple packets mDNSu32 PoofCacheDeletions; // Number of times the cache was deleted due to POOF mDNSu32 UnicastBitInQueries; // Queries with QU bit set mDNSu32 NormalQueries; // Queries with QU bit not set mDNSu32 MatchingAnswersForQueries; // Queries for which we had a response mDNSu32 UnicastResponses; // Unicast responses to queries mDNSu32 MulticastResponses; // Multicast responses to queries mDNSu32 UnicastDemotedToMulticast; // Number of times unicast demoted to multicast mDNSu32 Sleeps; // Total sleeps mDNSu32 Wakes; // Total wakes mDNSu32 InterfaceUp; // Total Interface UP events mDNSu32 InterfaceUpFlap; // Total Interface UP events with flaps mDNSu32 InterfaceDown; // Total Interface Down events mDNSu32 InterfaceDownFlap; // Total Interface Down events with flaps mDNSu32 CacheRefreshQueries; // Number of queries that we sent for refreshing cache mDNSu32 CacheRefreshed; // Number of times the cache was refreshed due to a response mDNSu32 WakeOnResolves; // Number of times we did a wake on resolve } mDNSStatistics; extern void LogMDNSStatisticsToFD(int fd, mDNS *const m); // Time constant (~= 260 hours ~= 10 days and 21 hours) used to set // various time values to a point well into the future. #define FutureTime 0x38000000 struct mDNS_struct { // Internal state fields. These hold the main internal state of mDNSCore; // the client layer needn't be concerned with them. // No fields need to be set up by the client prior to calling mDNS_Init(); // all required data is passed as parameters to that function. mDNS_PlatformSupport *p; // Pointer to platform-specific data of indeterminite size mDNSs32 NetworkChanged; mDNSBool CanReceiveUnicastOn5353; mDNSBool AdvertiseLocalAddresses; mDNSBool DivertMulticastAdvertisements; // from interfaces that do not advertise local addresses to local-only mStatus mDNSPlatformStatus; mDNSIPPort UnicastPort4; mDNSIPPort UnicastPort6; mDNSEthAddr PrimaryMAC; // Used as unique host ID mDNSCallback *MainCallback; void *MainContext; // For debugging: To catch and report locking failures mDNSu32 mDNS_busy; // Incremented between mDNS_Lock/mDNS_Unlock section mDNSu32 mDNS_reentrancy; // Incremented when calling a client callback mDNSu8 lock_rrcache; // For debugging: Set at times when these lists may not be modified mDNSu8 lock_Questions; mDNSu8 lock_Records; // Task Scheduling variables mDNSs32 timenow_adjust; // Correction applied if we ever discover time went backwards mDNSs32 timenow; // The time that this particular activation of the mDNS code started mDNSs32 timenow_last; // The time the last time we ran mDNSs32 NextScheduledEvent; // Derived from values below mDNSs32 ShutdownTime; // Set when we're shutting down; allows us to skip some unnecessary steps mDNSs32 SuppressSending; // Don't send local-link mDNS packets during this time mDNSs32 NextCacheCheck; // Next time to refresh cache record before it expires mDNSs32 NextScheduledQuery; // Next time to send query in its exponential backoff sequence mDNSs32 NextScheduledProbe; // Next time to probe for new authoritative record mDNSs32 NextScheduledResponse; // Next time to send authoritative record(s) in responses mDNSs32 NextScheduledNATOp; // Next time to send NAT-traversal packets mDNSs32 NextScheduledSPS; // Next time to purge expiring Sleep Proxy records mDNSs32 NextScheduledKA; // Next time to send Keepalive packets (SPS) #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) mDNSs32 NextBonjourDisableTime; // Next time to leave multicast group if Bonjour on Demand is enabled mDNSu8 BonjourEnabled; // Non zero if Bonjour is currently enabled by the Bonjour on Demand logic #endif mDNSs32 RandomQueryDelay; // For de-synchronization of query packets on the wire mDNSu32 RandomReconfirmDelay; // For de-synchronization of reconfirmation queries on the wire mDNSs32 PktNum; // Unique sequence number assigned to each received packet mDNSs32 MPktNum; // Unique sequence number assigned to each received Multicast packet mDNSu8 LocalRemoveEvents; // Set if we may need to deliver remove events for local-only questions and/or local-only records mDNSu8 SleepState; // Set if we're sleeping mDNSu8 SleepSeqNum; // "Epoch number" of our current period of wakefulness mDNSu8 SystemWakeOnLANEnabled; // Set if we want to register with a Sleep Proxy before going to sleep mDNSu8 SentSleepProxyRegistration; // Set if we registered (or tried to register) with a Sleep Proxy mDNSu8 SystemSleepOnlyIfWakeOnLAN; // Set if we may only sleep if we managed to register with a Sleep Proxy mDNSs32 AnnounceOwner; // After waking from sleep, include OWNER option in packets until this time mDNSs32 DelaySleep; // To inhibit re-sleeping too quickly right after wake mDNSs32 SleepLimit; // Time window to allow deregistrations, etc., // during which underying platform layer should inhibit system sleep mDNSs32 TimeSlept; // Time we went to sleep. mDNSs32 UnicastPacketsSent; // Number of unicast packets sent. mDNSs32 MulticastPacketsSent; // Number of multicast packets sent. mDNSs32 RemoteSubnet; // Multicast packets received from outside our subnet. mDNSs32 NextScheduledSPRetry; // Time next sleep proxy registration action is required. // Only valid if SleepLimit is nonzero and DelaySleep is zero. mDNSs32 NextScheduledStopTime; // Next time to stop a question mDNSs32 NextBLEServiceTime; // Next time to call the BLE discovery management layer. Non zero when active. // These fields only required for mDNS Searcher... DNSQuestion *Questions; // List of all registered questions, active and inactive DNSQuestion *NewQuestions; // Fresh questions not yet answered from cache DNSQuestion *CurrentQuestion; // Next question about to be examined in AnswerLocalQuestions() DNSQuestion *LocalOnlyQuestions; // Questions with InterfaceID set to mDNSInterface_LocalOnly or mDNSInterface_P2P DNSQuestion *NewLocalOnlyQuestions; // Fresh local-only or P2P questions not yet answered DNSQuestion *RestartQuestion; // Questions that are being restarted (stop followed by start) mDNSu32 rrcache_size; // Total number of available cache entries mDNSu32 rrcache_totalused; // Number of cache entries currently occupied mDNSu32 rrcache_totalused_unicast; // Number of cache entries currently occupied by unicast mDNSu32 rrcache_active; // Number of cache entries currently occupied by records that answer active questions mDNSu32 rrcache_report; CacheEntity *rrcache_free; CacheGroup *rrcache_hash[CACHE_HASH_SLOTS]; mDNSs32 rrcache_nextcheck[CACHE_HASH_SLOTS]; AuthHash rrauth; // Fields below only required for mDNS Responder... domainlabel nicelabel; // Rich text label encoded using canonically precomposed UTF-8 domainlabel hostlabel; // Conforms to RFC 1034 "letter-digit-hyphen" ARPANET host name rules domainname MulticastHostname; // Fully Qualified "dot-local" Host Name, e.g. "Foo.local." #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) domainname RandomizedHostname; // Randomized hostname to use for services involving AWDL interfaces. This is to // avoid using a hostname derived from the device's name, which may contain the // owner's real name, (e.g., "Steve's iPhone" -> "Steves-iPhone.local"), which is a // privacy concern. mDNSu32 AutoTargetAWDLIncludedCount;// Number of registered AWDL-included auto-target records. mDNSu32 AutoTargetAWDLOnlyCount; // Number of registered AWDL-only auto-target records. #endif UTF8str255 HIHardware; UTF8str255 HISoftware; AuthRecord DeviceInfo; AuthRecord *ResourceRecords; AuthRecord *DuplicateRecords; // Records currently 'on hold' because they are duplicates of existing records AuthRecord *NewLocalRecords; // Fresh AuthRecords (public) not yet delivered to our local-only questions AuthRecord *CurrentRecord; // Next AuthRecord about to be examined mDNSBool NewLocalOnlyRecords; // Fresh AuthRecords (local only) not yet delivered to our local questions NetworkInterfaceInfo *HostInterfaces; mDNSs32 ProbeFailTime; mDNSu32 NumFailedProbes; mDNSs32 SuppressProbes; Platform_t mDNS_plat; // Why is this here in the “only required for mDNS Responder” section? -- SC // Unicast-specific data mDNSs32 NextuDNSEvent; // uDNS next event mDNSs32 NextSRVUpdate; // Time to perform delayed update #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) DNSServer *DNSServers; // list of DNS servers #endif McastResolver *McastResolvers; // list of Mcast Resolvers mDNSAddr Router; mDNSAddr AdvertisedV4; // IPv4 address pointed to by hostname mDNSAddr AdvertisedV6; // IPv6 address pointed to by hostname DomainAuthInfo *AuthInfoList; // list of domains requiring authentication for updates DNSQuestion ReverseMap; // Reverse-map query to find static hostname for service target DNSQuestion AutomaticBrowseDomainQ; domainname StaticHostname; // Current answer to reverse-map query domainname FQDN; HostnameInfo *Hostnames; // List of registered hostnames + hostname metadata mDNSu32 WABBrowseQueriesCount; // Number of WAB Browse domain enumeration queries (b, db) callers mDNSu32 WABLBrowseQueriesCount; // Number of legacy WAB Browse domain enumeration queries (lb) callers mDNSu32 WABRegQueriesCount; // Number of WAB Registration domain enumeration queries (r, dr) callers mDNSu8 SearchDomainsHash[MD5_LEN]; // NAT-Traversal fields NATTraversalInfo LLQNAT; // Single shared NAT Traversal to receive inbound LLQ notifications NATTraversalInfo *NATTraversals; NATTraversalInfo *CurrentNATTraversal; mDNSs32 retryIntervalGetAddr; // delta between time sent and retry for NAT-PMP & UPnP/IGD external address request mDNSs32 retryGetAddr; // absolute time when we retry for NAT-PMP & UPnP/IGD external address request mDNSv4Addr ExtAddress; // the external address discovered via NAT-PMP or UPnP/IGD mDNSu32 PCPNonce[3]; // the nonce if using PCP UDPSocket *NATMcastRecvskt; // For receiving PCP & NAT-PMP announcement multicasts from router on port 5350 mDNSu32 LastNATupseconds; // NAT engine uptime in seconds, from most recent NAT packet mDNSs32 LastNATReplyLocalTime; // Local time in ticks when most recent NAT packet was received mDNSu16 LastNATMapResultCode; // Most recent error code for mappings tcpLNTInfo tcpAddrInfo; // legacy NAT traversal TCP connection info for external address tcpLNTInfo tcpDeviceInfo; // legacy NAT traversal TCP connection info for device info tcpLNTInfo *tcpInfoUnmapList; // list of pending unmap requests mDNSInterfaceID UPnPInterfaceID; UDPSocket *SSDPSocket; // For SSDP request/response mDNSBool SSDPWANPPPConnection; // whether we should send the SSDP query for WANIPConnection or WANPPPConnection mDNSIPPort UPnPRouterPort; // port we send discovery messages to mDNSIPPort UPnPSOAPPort; // port we send SOAP messages to char *UPnPRouterURL; // router's URL string mDNSBool UPnPWANPPPConnection; // whether we're using WANIPConnection or WANPPPConnection char *UPnPSOAPURL; // router's SOAP control URL string char *UPnPRouterAddressString; // holds both the router's address and port char *UPnPSOAPAddressString; // holds both address and port for SOAP messages // DNS Push Notification fields DNSPushNotificationServer *DNSPushServers; // DNS Push Notification Servers DNSPushNotificationZone *DNSPushZones; // Sleep Proxy client fields AuthRecord *SPSRRSet; // To help the client keep track of the records registered with the sleep proxy // Sleep Proxy Server fields mDNSu8 SPSType; // 0 = off, 10-99 encodes desirability metric mDNSu8 SPSPortability; // 10-99 mDNSu8 SPSMarginalPower; // 10-99 mDNSu8 SPSTotalPower; // 10-99 mDNSu8 SPSFeatureFlags; // Features supported. Currently 1 = TCP KeepAlive supported. mDNSu8 SPSState; // 0 = off, 1 = running, 2 = shutting down, 3 = suspended during sleep mDNSInterfaceID SPSProxyListChanged; UDPSocket *SPSSocket; #ifndef SPC_DISABLED ServiceRecordSet SPSRecords; #endif mDNSQuestionCallback *SPSBrowseCallback; // So the platform layer can do something useful with SPS browse results int ProxyRecords; // Total number of records we're holding as proxy #define MAX_PROXY_RECORDS 10000 /* DOS protection: 400 machines at 25 records each */ #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) WCFConnection *WCF; #endif // DNS Proxy fields mDNSu32 dp_ipintf[MaxIp]; // input interface index list from the DNS Proxy Client mDNSu32 dp_opintf; // output interface index from the DNS Proxy Client int notifyToken; int uds_listener_skt; // Listening socket for incoming UDS clients. This should not be here -- it's private to uds_daemon.c and nothing to do with mDNSCore -- SC mDNSu32 AutoTargetServices; // # of services that have AutoTarget set #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) // Counters used in Bonjour on Demand logic. mDNSu32 NumAllInterfaceRecords; // Right now we count *all* multicast records here. Later we may want to change to count interface-specific records separately. (This count includes records on the DuplicateRecords list too.) mDNSu32 NumAllInterfaceQuestions; // Right now we count *all* multicast questions here. Later we may want to change to count interface-specific questions separately. #endif mDNSStatistics mDNSStats; // Fixed storage, to avoid creating large objects on the stack // The imsg is declared as a union with a pointer type to enforce CPU-appropriate alignment union { DNSMessage m; void *p; } imsg; // Incoming message received from wire DNSMessage omsg; // Outgoing message we're building LargeCacheRecord rec; // Resource Record extracted from received message #ifndef MaxMsg #define MaxMsg 512 #endif char MsgBuffer[MaxMsg]; // Temp storage used while building error log messages (keep at end of struct) }; #define FORALL_CACHERECORDS(SLOT,CG,CR) \ for ((SLOT) = 0; (SLOT) < CACHE_HASH_SLOTS; (SLOT)++) \ for ((CG)=m->rrcache_hash[(SLOT)]; (CG); (CG)=(CG)->next) \ for ((CR) = (CG)->members; (CR); (CR)=(CR)->next) // *************************************************************************** #if 0 #pragma mark - #pragma mark - Useful Static Constants #endif extern const mDNSInterfaceID mDNSInterface_Any; // Zero extern const mDNSInterfaceID mDNSInterface_LocalOnly; // Special value extern const mDNSInterfaceID mDNSInterfaceMark; // Special value extern const mDNSInterfaceID mDNSInterface_P2P; // Special value extern const mDNSInterfaceID uDNSInterfaceMark; // Special value extern const mDNSInterfaceID mDNSInterface_BLE; // Special value #define LocalOnlyOrP2PInterface(INTERFACE) (((INTERFACE) == mDNSInterface_LocalOnly) || ((INTERFACE) == mDNSInterface_P2P) || ((INTERFACE) == mDNSInterface_BLE)) extern const mDNSIPPort DiscardPort; extern const mDNSIPPort SSHPort; extern const mDNSIPPort UnicastDNSPort; extern const mDNSIPPort SSDPPort; extern const mDNSIPPort IPSECPort; extern const mDNSIPPort NSIPCPort; extern const mDNSIPPort NATPMPAnnouncementPort; extern const mDNSIPPort NATPMPPort; extern const mDNSIPPort DNSEXTPort; extern const mDNSIPPort MulticastDNSPort; extern const mDNSIPPort LoopbackIPCPort; extern const mDNSIPPort PrivateDNSPort; extern const OwnerOptData zeroOwner; extern const mDNSIPPort zeroIPPort; extern const mDNSv4Addr zerov4Addr; extern const mDNSv6Addr zerov6Addr; extern const mDNSEthAddr zeroEthAddr; extern const mDNSv4Addr onesIPv4Addr; extern const mDNSv6Addr onesIPv6Addr; extern const mDNSEthAddr onesEthAddr; extern const mDNSAddr zeroAddr; extern const mDNSv4Addr AllDNSAdminGroup; extern const mDNSv4Addr AllHosts_v4; extern const mDNSv6Addr AllHosts_v6; extern const mDNSv6Addr NDP_prefix; extern const mDNSEthAddr AllHosts_v6_Eth; extern const mDNSAddr AllDNSLinkGroup_v4; extern const mDNSAddr AllDNSLinkGroup_v6; extern const mDNSOpaque16 zeroID; extern const mDNSOpaque16 onesID; extern const mDNSOpaque16 QueryFlags; extern const mDNSOpaque16 uQueryFlags; extern const mDNSOpaque16 ResponseFlags; extern const mDNSOpaque16 UpdateReqFlags; extern const mDNSOpaque16 UpdateRespFlags; extern const mDNSOpaque16 SubscribeFlags; extern const mDNSOpaque16 UnSubscribeFlags; extern const mDNSOpaque16 uDNSSecQueryFlags; extern const mDNSOpaque64 zeroOpaque64; extern const mDNSOpaque128 zeroOpaque128; extern mDNSBool StrictUnicastOrdering; #define localdomain (*(const domainname *)"\x5" "local") #define DeviceInfoName (*(const domainname *)"\xC" "_device-info" "\x4" "_tcp") #define LocalDeviceInfoName (*(const domainname *)"\xC" "_device-info" "\x4" "_tcp" "\x5" "local") #define SleepProxyServiceType (*(const domainname *)"\xC" "_sleep-proxy" "\x4" "_udp") // *************************************************************************** #if 0 #pragma mark - #pragma mark - Inline functions #endif #if (defined(_MSC_VER)) #define mDNSinline static __inline #elif ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9))) #define mDNSinline static inline #else #define mDNSinline static inline #endif // If we're not doing inline functions, then this header needs to have the extern declarations #if !defined(mDNSinline) #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern int CountOfUnicastDNSServers(mDNS *const m); #endif extern mDNSs32 NonZeroTime(mDNSs32 t); extern mDNSu16 mDNSVal16(mDNSOpaque16 x); extern mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v); #endif // If we're compiling the particular C file that instantiates our inlines, then we // define "mDNSinline" (to empty string) so that we generate code in the following section #if (!defined(mDNSinline) && mDNS_InstantiateInlines) #define mDNSinline #endif #ifdef mDNSinline #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSinline int CountOfUnicastDNSServers(mDNS *const m) { int count = 0; DNSServer *ptr = m->DNSServers; while(ptr) { if(!(ptr->flags & DNSServerFlag_Delete)) count++; ptr = ptr->next; } return (count); } #endif mDNSinline mDNSs32 NonZeroTime(mDNSs32 t) { if (t) return(t);else return(1);} mDNSinline mDNSu16 mDNSVal16(mDNSOpaque16 x) { return((mDNSu16)((mDNSu16)x.b[0] << 8 | (mDNSu16)x.b[1])); } mDNSinline mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v) { mDNSOpaque16 x; x.b[0] = (mDNSu8)(v >> 8); x.b[1] = (mDNSu8)(v & 0xFF); return(x); } #endif // *************************************************************************** #if 0 #pragma mark - #pragma mark - Main Client Functions #endif // Every client should call mDNS_Init, passing in storage for the mDNS object and the mDNS_PlatformSupport object. // // Clients that are only advertising services should use mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize. // Clients that plan to perform queries (mDNS_StartQuery, mDNS_StartBrowse, etc.) // need to provide storage for the resource record cache, or the query calls will return 'mStatus_NoCache'. // The rrcachestorage parameter is the address of memory for the resource record cache, and // the rrcachesize parameter is the number of entries in the CacheRecord array passed in. // (i.e. the size of the cache memory needs to be sizeof(CacheRecord) * rrcachesize). // OS X 10.3 Panther uses an initial cache size of 64 entries, and then mDNSCore sends an // mStatus_GrowCache message if it needs more. // // Most clients should use mDNS_Init_AdvertiseLocalAddresses. This causes mDNSCore to automatically // create the correct address records for all the hosts interfaces. If you plan to advertise // services being offered by the local machine, this is almost always what you want. // There are two cases where you might use mDNS_Init_DontAdvertiseLocalAddresses: // 1. A client-only device, that browses for services but doesn't advertise any of its own. // 2. A proxy-registration service, that advertises services being offered by other machines, and takes // the appropriate steps to manually create the correct address records for those other machines. // In principle, a proxy-like registration service could manually create address records for its own machine too, // but this would be pointless extra effort when using mDNS_Init_AdvertiseLocalAddresses does that for you. // // Note that a client-only device that wishes to prohibit multicast advertisements (e.g. from // higher-layer API calls) must also set DivertMulticastAdvertisements in the mDNS structure and // advertise local address(es) on a loopback interface. // // When mDNS has finished setting up the client's callback is called // A client can also spin and poll the mDNSPlatformStatus field to see when it changes from mStatus_Waiting to mStatus_NoError // // Call mDNS_StartExit to tidy up before exiting // Because exiting may be an asynchronous process (e.g. if unicast records need to be deregistered) // client layer may choose to wait until mDNS_ExitNow() returns true before calling mDNS_FinalExit(). // // Call mDNS_Register with a completed AuthRecord object to register a resource record // If the resource record type is kDNSRecordTypeUnique (or kDNSknownunique) then if a conflicting resource record is discovered, // the resource record's mDNSRecordCallback will be called with error code mStatus_NameConflict. The callback should deregister // the record, and may then try registering the record again after picking a new name (e.g. by automatically appending a number). // Following deregistration, the RecordCallback will be called with result mStatus_MemFree to signal that it is safe to deallocate // the record's storage (memory must be freed asynchronously to allow for goodbye packets and dynamic update deregistration). // // Call mDNS_StartQuery to initiate a query. mDNS will proceed to issue Multicast DNS query packets, and any time a response // is received containing a record which matches the question, the DNSQuestion's mDNSAnswerCallback function will be called // Call mDNS_StopQuery when no more answers are required // // Care should be taken on multi-threaded or interrupt-driven environments. // The main mDNS routines call mDNSPlatformLock() on entry and mDNSPlatformUnlock() on exit; // each platform layer needs to implement these appropriately for its respective platform. // For example, if the support code on a particular platform implements timer callbacks at interrupt time, then // mDNSPlatformLock/Unlock need to disable interrupts or do similar concurrency control to ensure that the mDNS // code is not entered by an interrupt-time timer callback while in the middle of processing a client call. extern mStatus mDNS_Init (mDNS *const m, mDNS_PlatformSupport *const p, CacheEntity *rrcachestorage, mDNSu32 rrcachesize, mDNSBool AdvertiseLocalAddresses, mDNSCallback *Callback, void *Context); // See notes above on use of NoCache/ZeroCacheSize #define mDNS_Init_NoCache mDNSNULL #define mDNS_Init_ZeroCacheSize 0 // See notes above on use of Advertise/DontAdvertiseLocalAddresses #define mDNS_Init_AdvertiseLocalAddresses mDNStrue #define mDNS_Init_DontAdvertiseLocalAddresses mDNSfalse #define mDNS_Init_NoInitCallback mDNSNULL #define mDNS_Init_NoInitCallbackContext mDNSNULL extern void mDNS_ConfigChanged(mDNS *const m); extern void mDNS_GrowCache (mDNS *const m, CacheEntity *storage, mDNSu32 numrecords); extern void mDNS_StartExit (mDNS *const m); extern void mDNS_FinalExit (mDNS *const m); #define mDNS_Close(m) do { mDNS_StartExit(m); mDNS_FinalExit(m); } while(0) #define mDNS_ExitNow(m, now) ((now) - (m)->ShutdownTime >= 0 || (!(m)->ResourceRecords)) extern mDNSs32 mDNS_Execute (mDNS *const m); extern mStatus mDNS_Register (mDNS *const m, AuthRecord *const rr); extern mStatus mDNS_Update (mDNS *const m, AuthRecord *const rr, mDNSu32 newttl, const mDNSu16 newrdlength, RData *const newrdata, mDNSRecordUpdateCallback *Callback); extern mStatus mDNS_Deregister(mDNS *const m, AuthRecord *const rr); extern mStatus mDNS_StartQuery(mDNS *const m, DNSQuestion *const question); extern mStatus mDNS_StopQuery (mDNS *const m, DNSQuestion *const question); extern mStatus mDNS_StopQueryWithRemoves(mDNS *const m, DNSQuestion *const question); extern mStatus mDNS_Reconfirm (mDNS *const m, CacheRecord *const cacherr); extern mStatus mDNS_Reconfirm_internal(mDNS *const m, CacheRecord *const rr, mDNSu32 interval); extern mStatus mDNS_ReconfirmByValue(mDNS *const m, ResourceRecord *const rr); extern void mDNS_PurgeCacheResourceRecord(mDNS *const m, CacheRecord *rr); extern mDNSs32 mDNS_TimeNow(const mDNS *const m); extern mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal); extern mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal); extern mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal); extern DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name); extern void mDNS_UpdateAllowSleep(mDNS *const m); // *************************************************************************** #if 0 #pragma mark - #pragma mark - Platform support functions that are accessible to the client layer too #endif extern mDNSs32 mDNSPlatformOneSecond; // *************************************************************************** #if 0 #pragma mark - #pragma mark - General utility and helper functions #endif // mDNS_Dereg_normal is used for most calls to mDNS_Deregister_internal // mDNS_Dereg_rapid is used to send one goodbye instead of three, when we want the memory available for reuse sooner // mDNS_Dereg_conflict is used to indicate that this record is being forcibly deregistered because of a conflict // mDNS_Dereg_repeat is used when cleaning up, for records that may have already been forcibly deregistered typedef enum { mDNS_Dereg_normal, mDNS_Dereg_rapid, mDNS_Dereg_conflict, mDNS_Dereg_repeat } mDNS_Dereg_type; // mDNS_RegisterService is a single call to register the set of resource records associated with a given named service. // // // mDNS_AddRecordToService adds an additional record to a Service Record Set. This record may be deregistered // via mDNS_RemoveRecordFromService, or by deregistering the service. mDNS_RemoveRecordFromService is passed a // callback to free the memory associated with the extra RR when it is safe to do so. The ExtraResourceRecord // object can be found in the record's context pointer. // mDNS_GetBrowseDomains is a special case of the mDNS_StartQuery call, where the resulting answers // are a list of PTR records indicating (in the rdata) domains that are recommended for browsing. // After getting the list of domains to browse, call mDNS_StopQuery to end the search. // mDNS_GetDefaultBrowseDomain returns the name of the domain that should be highlighted by default. // // mDNS_GetRegistrationDomains and mDNS_GetDefaultRegistrationDomain are the equivalent calls to get the list // of one or more domains that should be offered to the user as choices for where they may register their service, // and the default domain in which to register in the case where the user has made no selection. extern void mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID, mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, AuthRecType artype, mDNSRecordCallback Callback, void *Context); extern mStatus mDNS_RegisterService (mDNS *const m, ServiceRecordSet *sr, const domainlabel *const name, const domainname *const type, const domainname *const domain, const domainname *const host, mDNSIPPort port, RData *txtrdata, const mDNSu8 txtinfo[], mDNSu16 txtlen, AuthRecord *SubTypes, mDNSu32 NumSubTypes, mDNSInterfaceID InterfaceID, mDNSServiceCallback Callback, void *Context, mDNSu32 flags); extern mStatus mDNS_AddRecordToService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, RData *rdata, mDNSu32 ttl, mDNSu32 flags); extern mStatus mDNS_RemoveRecordFromService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, mDNSRecordCallback MemFreeCallback, void *Context); extern mStatus mDNS_RenameAndReregisterService(mDNS *const m, ServiceRecordSet *const sr, const domainlabel *newname); extern mStatus mDNS_DeregisterService_drt(mDNS *const m, ServiceRecordSet *sr, mDNS_Dereg_type drt); #define mDNS_DeregisterService(M,S) mDNS_DeregisterService_drt((M), (S), mDNS_Dereg_normal) extern mStatus mDNS_RegisterNoSuchService(mDNS *const m, AuthRecord *const rr, const domainlabel *const name, const domainname *const type, const domainname *const domain, const domainname *const host, const mDNSInterfaceID InterfaceID, mDNSRecordCallback Callback, void *Context, mDNSu32 flags); #define mDNS_DeregisterNoSuchService mDNS_Deregister extern void mDNS_SetupQuestion(DNSQuestion *const q, const mDNSInterfaceID InterfaceID, const domainname *const name, const mDNSu16 qtype, mDNSQuestionCallback *const callback, void *const context); extern mStatus mDNS_StartBrowse(mDNS *const m, DNSQuestion *const question, const domainname *const srv, const domainname *const domain, const mDNSInterfaceID InterfaceID, mDNSu32 flags, mDNSBool ForceMCast, mDNSBool useBackgroundTrafficClass, mDNSQuestionCallback *Callback, void *Context); #define mDNS_StopBrowse mDNS_StopQuery typedef enum { mDNS_DomainTypeBrowse = 0, mDNS_DomainTypeBrowseDefault = 1, mDNS_DomainTypeBrowseAutomatic = 2, mDNS_DomainTypeRegistration = 3, mDNS_DomainTypeRegistrationDefault = 4, mDNS_DomainTypeMax = 4 } mDNS_DomainType; extern const char *const mDNS_DomainTypeNames[]; extern mStatus mDNS_GetDomains(mDNS *const m, DNSQuestion *const question, mDNS_DomainType DomainType, const domainname *dom, const mDNSInterfaceID InterfaceID, mDNSQuestionCallback *Callback, void *Context); #define mDNS_StopGetDomains mDNS_StopQuery extern mStatus mDNS_AdvertiseDomains(mDNS *const m, AuthRecord *rr, mDNS_DomainType DomainType, const mDNSInterfaceID InterfaceID, char *domname); #define mDNS_StopAdvertiseDomains mDNS_Deregister extern mDNSOpaque16 mDNS_NewMessageID(mDNS *const m); extern mDNSBool mDNS_AddressIsLocalSubnet(mDNS *const m, const mDNSInterfaceID InterfaceID, const mDNSAddr *addr); #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern DNSServer *GetServerForQuestion(mDNS *m, DNSQuestion *question); #endif extern mDNSu32 SetValidDNSServers(mDNS *m, DNSQuestion *question); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern mDNSBool ShouldSuppressUnicastQuery(const DNSQuestion *q, mdns_dns_service_t dnsservice); extern mDNSBool LocalRecordRmvEventsForQuestion(mDNS *m, DNSQuestion *q); #endif // *************************************************************************** #if 0 #pragma mark - #pragma mark - DNS name utility functions #endif // In order to expose the full capabilities of the DNS protocol (which allows any arbitrary eight-bit values // in domain name labels, including unlikely characters like ascii nulls and even dots) all the mDNS APIs // work with DNS's native length-prefixed strings. For convenience in C, the following utility functions // are provided for converting between C's null-terminated strings and DNS's length-prefixed strings. // Assignment // A simple C structure assignment of a domainname can cause a protection fault by accessing unmapped memory, // because that object is defined to be 256 bytes long, but not all domainname objects are truly the full size. // This macro uses mDNSPlatformMemCopy() to make sure it only touches the actual bytes that are valid. #define AssignDomainName(DST, SRC) do { mDNSu16 len__ = DomainNameLength((SRC)); \ if (len__ <= MAX_DOMAIN_NAME) mDNSPlatformMemCopy((DST)->c, (SRC)->c, len__); else (DST)->c[0] = 0; } while(0) #define AssignConstStringDomainName(DST, SRC) do { \ mDNSu16 len__ = DomainNameLengthLimit((domainname *)(SRC), (mDNSu8 *)(SRC) + sizeof (SRC)); \ if (len__ <= MAX_DOMAIN_NAME) \ mDNSPlatformMemCopy((DST)->c, (SRC), len__); else (DST)->c[0] = 0; } while(0) // Comparison functions #define SameDomainLabelCS(A,B) ((A)[0] == (B)[0] && mDNSPlatformMemSame((A)+1, (B)+1, (A)[0])) extern mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b); extern mDNSBool SameDomainName(const domainname *const d1, const domainname *const d2); extern mDNSBool SameDomainNameCS(const domainname *const d1, const domainname *const d2); typedef mDNSBool DomainNameComparisonFn (const domainname *const d1, const domainname *const d2); extern mDNSBool IsLocalDomain(const domainname *d); // returns true for domains that by default should be looked up using link-local multicast #define StripFirstLabel(X) ((const domainname *)& (X)->c[(X)->c[0] ? 1 + (X)->c[0] : 0]) #define FirstLabel(X) ((const domainlabel *)(X)) #define SecondLabel(X) ((const domainlabel *)StripFirstLabel(X)) #define ThirdLabel(X) ((const domainlabel *)StripFirstLabel(StripFirstLabel(X))) extern const mDNSu8 *LastLabel(const domainname *d); // Get total length of domain name, in native DNS format, including terminal root label // (e.g. length of "com." is 5 (length byte, three data bytes, final zero) extern mDNSu16 DomainNameLengthLimit(const domainname *const name, const mDNSu8 *limit); #define DomainNameLength(name) DomainNameLengthLimit((name), (name)->c + MAX_DOMAIN_NAME) // Append functions to append one or more labels to an existing native format domain name: // AppendLiteralLabelString adds a single label from a literal C string, with no escape character interpretation. // AppendDNSNameString adds zero or more labels from a C string using conventional DNS dots-and-escaping interpretation // AppendDomainLabel adds a single label from a native format domainlabel // AppendDomainName adds zero or more labels from a native format domainname extern mDNSu8 *AppendLiteralLabelString(domainname *const name, const char *cstr); extern mDNSu8 *AppendDNSNameString (domainname *const name, const char *cstr); extern mDNSu8 *AppendDomainLabel (domainname *const name, const domainlabel *const label); extern mDNSu8 *AppendDomainName (domainname *const name, const domainname *const append); // Convert from null-terminated string to native DNS format: // The DomainLabel form makes a single label from a literal C string, with no escape character interpretation. // The DomainName form makes native format domain name from a C string using conventional DNS interpretation: // dots separate labels, and within each label, '\.' represents a literal dot, '\\' represents a literal // backslash and backslash with three decimal digits (e.g. \000) represents an arbitrary byte value. extern mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr); extern mDNSu8 *MakeDomainNameFromDNSNameString (domainname *const name, const char *cstr); // Convert native format domainlabel or domainname back to C string format // IMPORTANT: // When using ConvertDomainLabelToCString, the target buffer must be MAX_ESCAPED_DOMAIN_LABEL (254) bytes long // to guarantee there will be no buffer overrun. It is only safe to use a buffer shorter than this in rare cases // where the label is known to be constrained somehow (for example, if the label is known to be either "_tcp" or "_udp"). // Similarly, when using ConvertDomainNameToCString, the target buffer must be MAX_ESCAPED_DOMAIN_NAME (1009) bytes long. // See definitions of MAX_ESCAPED_DOMAIN_LABEL and MAX_ESCAPED_DOMAIN_NAME for more detailed explanation. extern char *ConvertDomainLabelToCString_withescape(const domainlabel *const name, char *cstr, char esc); #define ConvertDomainLabelToCString_unescaped(D,C) ConvertDomainLabelToCString_withescape((D), (C), 0) #define ConvertDomainLabelToCString(D,C) ConvertDomainLabelToCString_withescape((D), (C), '\\') extern char *ConvertDomainNameToCString_withescape(const domainname *const name, char *cstr, char esc); #define ConvertDomainNameToCString_unescaped(D,C) ConvertDomainNameToCString_withescape((D), (C), 0) #define ConvertDomainNameToCString(D,C) ConvertDomainNameToCString_withescape((D), (C), '\\') extern void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel); #define ValidTransportProtocol(X) ( (X)[0] == 4 && (X)[1] == '_' && \ ((((X)[2] | 0x20) == 'u' && ((X)[3] | 0x20) == 'd') || (((X)[2] | 0x20) == 't' && ((X)[3] | 0x20) == 'c')) && \ ((X)[4] | 0x20) == 'p') extern mDNSu8 *ConstructServiceName(domainname *const fqdn, const domainlabel *name, const domainname *type, const domainname *const domain); extern mDNSBool DeconstructServiceName(const domainname *const fqdn, domainlabel *const name, domainname *const type, domainname *const domain); // Note: Some old functions have been replaced by more sensibly-named versions. // You can uncomment the hash-defines below if you don't want to have to change your source code right away. // When updating your code, note that (unlike the old versions) *all* the new routines take the target object // as their first parameter. //#define ConvertCStringToDomainName(SRC,DST) MakeDomainNameFromDNSNameString((DST),(SRC)) //#define ConvertCStringToDomainLabel(SRC,DST) MakeDomainLabelFromLiteralString((DST),(SRC)) //#define AppendStringLabelToName(DST,SRC) AppendLiteralLabelString((DST),(SRC)) //#define AppendStringNameToName(DST,SRC) AppendDNSNameString((DST),(SRC)) //#define AppendDomainLabelToName(DST,SRC) AppendDomainLabel((DST),(SRC)) //#define AppendDomainNameToName(DST,SRC) AppendDomainName((DST),(SRC)) // *************************************************************************** #if 0 #pragma mark - #pragma mark - Other utility functions and macros #endif // mDNS_vsnprintf/snprintf return the number of characters written, excluding the final terminating null. // The output is always null-terminated: for example, if the output turns out to be exactly buflen long, // then the output will be truncated by one character to allow space for the terminating null. // Unlike standard C vsnprintf/snprintf, they return the number of characters *actually* written, // not the number of characters that *would* have been printed were buflen unlimited. extern mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg) IS_A_PRINTF_STYLE_FUNCTION(3,0); extern mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4); extern void mDNS_snprintf_add(char **dst, const char *lim, const char *fmt, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4); extern mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id); extern char *DNSTypeName(mDNSu16 rrtype); extern const char *mStatusDescription(mStatus error); extern char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RDataBody *const rd1, char *const buffer); #define RRDisplayString(m, rr) GetRRDisplayString_rdb(rr, &(rr)->rdata->u, (m)->MsgBuffer) #define ARDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer) #define CRDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer) #define MortalityDisplayString(M) (M == Mortality_Mortal ? "mortal" : (M == Mortality_Immortal ? "immortal" : "ghost")) extern mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2); extern void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText); extern mDNSBool mDNSv4AddrIsRFC1918(const mDNSv4Addr * const addr); // returns true for RFC1918 private addresses #define mDNSAddrIsRFC1918(X) ((X)->type == mDNSAddrType_IPv4 && mDNSv4AddrIsRFC1918(&(X)->ip.v4)) extern const char *DNSScopeToString(mDNSu32 scope); // For PCP extern void mDNSAddrMapIPv4toIPv6(mDNSv4Addr* in, mDNSv6Addr* out); extern mDNSBool mDNSAddrIPv4FromMappedIPv6(mDNSv6Addr *in, mDNSv4Addr *out); #define mDNSSameIPPort(A,B) ((A).NotAnInteger == (B).NotAnInteger) #define mDNSSameOpaque16(A,B) ((A).NotAnInteger == (B).NotAnInteger) #define mDNSSameOpaque32(A,B) ((A).NotAnInteger == (B).NotAnInteger) #define mDNSSameOpaque64(A,B) ((A)->l[0] == (B)->l[0] && (A)->l[1] == (B)->l[1]) #define mDNSSameIPv4Address(A,B) ((A).NotAnInteger == (B).NotAnInteger) #define mDNSSameIPv6Address(A,B) ((A).l[0] == (B).l[0] && (A).l[1] == (B).l[1] && (A).l[2] == (B).l[2] && (A).l[3] == (B).l[3]) #define mDNSSameIPv6NetworkPart(A,B) ((A).l[0] == (B).l[0] && (A).l[1] == (B).l[1]) #define mDNSSameEthAddress(A,B) ((A)->w[0] == (B)->w[0] && (A)->w[1] == (B)->w[1] && (A)->w[2] == (B)->w[2]) #define mDNSIPPortIsZero(A) ((A).NotAnInteger == 0) #define mDNSOpaque16IsZero(A) ((A).NotAnInteger == 0) #define mDNSOpaque64IsZero(A) (((A)->l[0] | (A)->l[1] ) == 0) #define mDNSOpaque128IsZero(A) (((A)->l[0] | (A)->l[1] | (A)->l[2] | (A)->l[3]) == 0) #define mDNSIPv4AddressIsZero(A) ((A).NotAnInteger == 0) #define mDNSIPv6AddressIsZero(A) (((A).l[0] | (A).l[1] | (A).l[2] | (A).l[3]) == 0) #define mDNSEthAddressIsZero(A) (((A).w[0] | (A).w[1] | (A).w[2] ) == 0) #define mDNSIPv4AddressIsOnes(A) ((A).NotAnInteger == 0xFFFFFFFF) #define mDNSIPv6AddressIsOnes(A) (((A).l[0] & (A).l[1] & (A).l[2] & (A).l[3]) == 0xFFFFFFFF) #define mDNSAddressIsAllDNSLinkGroup(X) ( \ ((X)->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address((X)->ip.v4, AllDNSLinkGroup_v4.ip.v4)) || \ ((X)->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address((X)->ip.v6, AllDNSLinkGroup_v6.ip.v6)) ) #define mDNSAddressIsZero(X) ( \ ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsZero((X)->ip.v4)) || \ ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsZero((X)->ip.v6)) ) #define mDNSAddressIsValidNonZero(X) ( \ ((X)->type == mDNSAddrType_IPv4 && !mDNSIPv4AddressIsZero((X)->ip.v4)) || \ ((X)->type == mDNSAddrType_IPv6 && !mDNSIPv6AddressIsZero((X)->ip.v6)) ) #define mDNSAddressIsOnes(X) ( \ ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsOnes((X)->ip.v4)) || \ ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsOnes((X)->ip.v6)) ) #define mDNSAddressIsValid(X) ( \ ((X)->type == mDNSAddrType_IPv4) ? !(mDNSIPv4AddressIsZero((X)->ip.v4) || mDNSIPv4AddressIsOnes((X)->ip.v4)) : \ ((X)->type == mDNSAddrType_IPv6) ? !(mDNSIPv6AddressIsZero((X)->ip.v6) || mDNSIPv6AddressIsOnes((X)->ip.v6)) : mDNSfalse) #define mDNSv4AddressIsLinkLocal(X) ((X)->b[0] == 169 && (X)->b[1] == 254) #define mDNSv6AddressIsLinkLocal(X) ((X)->b[0] == 0xFE && ((X)->b[1] & 0xC0) == 0x80) #define mDNSAddressIsLinkLocal(X) ( \ ((X)->type == mDNSAddrType_IPv4) ? mDNSv4AddressIsLinkLocal(&(X)->ip.v4) : \ ((X)->type == mDNSAddrType_IPv6) ? mDNSv6AddressIsLinkLocal(&(X)->ip.v6) : mDNSfalse) // *************************************************************************** #if 0 #pragma mark - #pragma mark - Authentication Support #endif // Unicast DNS and Dynamic Update specific Client Calls // // mDNS_SetSecretForDomain tells the core to authenticate (via TSIG with an HMAC_MD5 hash of the shared secret) // when dynamically updating a given zone (and its subdomains). The key used in authentication must be in // domain name format. The shared secret must be a null-terminated base64 encoded string. A minimum size of // 16 bytes (128 bits) is recommended for an MD5 hash as per RFC 2485. // Calling this routine multiple times for a zone replaces previously entered values. Call with a NULL key // to disable authentication for the zone. A non-NULL autoTunnelPrefix means this is an AutoTunnel domain, // and the value is prepended to the IPSec identifier (used for key lookup) extern mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info, const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port); extern void RecreateNATMappings(mDNS *const m, const mDNSu32 waitTicks); // Hostname/Unicast Interface Configuration // All hostnames advertised point to one IPv4 address and/or one IPv6 address, set via SetPrimaryInterfaceInfo. Invoking this routine // updates all existing hostnames to point to the new address. // A hostname is added via AddDynDNSHostName, which points to the primary interface's v4 and/or v6 addresss // The status callback is invoked to convey success or failure codes - the callback should not modify the AuthRecord or free memory. // Added hostnames may be removed (deregistered) via mDNS_RemoveDynDNSHostName. // Host domains added prior to specification of the primary interface address and computer name will be deferred until // these values are initialized. // DNS servers used to resolve unicast queries are specified by mDNS_AddDNSServer. // For "split" DNS configurations, in which queries for different domains are sent to different servers (e.g. VPN and external), // a domain may be associated with a DNS server. For standard configurations, specify the root label (".") or NULL. extern void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext); extern void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn); extern void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router); #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, mDNSs32 serviceID, const mDNSAddr *addr, const mDNSIPPort port, ScopeType scopeType, mDNSu32 timeout, mDNSBool cellIntf, mDNSBool isExpensive, mDNSBool isConstrained, mDNSBool isCLAT46, mDNSu32 resGroupID, mDNSBool reqA, mDNSBool reqAAAA, mDNSBool reqDO); extern void PenalizeDNSServer(mDNS *const m, DNSQuestion *q, mDNSOpaque16 responseFlags); #endif extern void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID); extern McastResolver *mDNS_AddMcastResolver(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, mDNSu32 timeout); // We use ((void *)0) here instead of mDNSNULL to avoid compile warnings on gcc 4.2 #define mDNS_AddSearchDomain_CString(X, I) \ do { domainname d__; if (((X) != (void*)0) && MakeDomainNameFromDNSNameString(&d__, (X)) && d__.c[0]) mDNS_AddSearchDomain(&d__, I);} while(0) // Routines called by the core, exported by DNSDigest.c // Convert an arbitrary base64 encoded key key into an HMAC key (stored in AuthInfo struct) extern mDNSs32 DNSDigest_ConstructHMACKeyfromBase64(DomainAuthInfo *info, const char *b64key); // sign a DNS message. The message must be complete, with all values in network byte order. end points to the end // of the message, and is modified by this routine. numAdditionals is a pointer to the number of additional // records in HOST byte order, which is incremented upon successful completion of this routine. The function returns // the new end pointer on success, and NULL on failure. extern void DNSDigest_SignMessage(DNSMessage *msg, mDNSu8 **end, DomainAuthInfo *info, mDNSu16 tcode); #define SwapDNSHeaderBytes(M) do { \ (M)->h.numQuestions = (mDNSu16)((mDNSu8 *)&(M)->h.numQuestions )[0] << 8 | ((mDNSu8 *)&(M)->h.numQuestions )[1]; \ (M)->h.numAnswers = (mDNSu16)((mDNSu8 *)&(M)->h.numAnswers )[0] << 8 | ((mDNSu8 *)&(M)->h.numAnswers )[1]; \ (M)->h.numAuthorities = (mDNSu16)((mDNSu8 *)&(M)->h.numAuthorities)[0] << 8 | ((mDNSu8 *)&(M)->h.numAuthorities)[1]; \ (M)->h.numAdditionals = (mDNSu16)((mDNSu8 *)&(M)->h.numAdditionals)[0] << 8 | ((mDNSu8 *)&(M)->h.numAdditionals)[1]; \ } while (0) // verify a DNS message. The message must be complete, with all values in network byte order. end points to the // end of the record. tsig is a pointer to the resource record that contains the TSIG OPT record. info is // the matching key to use for verifying the message. This function expects that the additionals member // of the DNS message header has already had one subtracted from it. extern mDNSBool DNSDigest_VerifyMessage(DNSMessage *msg, mDNSu8 *end, LargeCacheRecord *tsig, DomainAuthInfo *info, mDNSu16 *rcode, mDNSu16 *tcode); // *************************************************************************** #if 0 #pragma mark - #pragma mark - PlatformSupport interface #endif // This section defines the interface to the Platform Support layer. // Normal client code should not use any of types defined here, or directly call any of the functions defined here. // The definitions are placed here because sometimes clients do use these calls indirectly, via other supported client operations. // For example, AssignDomainName is a macro defined using mDNSPlatformMemCopy() // Every platform support module must provide the following functions. // mDNSPlatformInit() typically opens a communication endpoint, and starts listening for mDNS packets. // When Setup is complete, the platform support layer calls mDNSCoreInitComplete(). // mDNSPlatformSendUDP() sends one UDP packet // When a packet is received, the PlatformSupport code calls mDNSCoreReceive() // mDNSPlatformClose() tidies up on exit // // Note: mDNSPlatformMemAllocate/mDNSPlatformMemFree are only required for handling oversized resource records and unicast DNS. // If your target platform has a well-defined specialized application, and you know that all the records it uses // are InlineCacheRDSize or less, then you can just make a simple mDNSPlatformMemAllocate() stub that always returns // NULL. InlineCacheRDSize is a compile-time constant, which is set by default to 68. If you need to handle records // a little larger than this and you don't want to have to implement run-time allocation and freeing, then you // can raise the value of this constant to a suitable value (at the expense of increased memory usage). // // USE CAUTION WHEN CALLING mDNSPlatformRawTime: The m->timenow_adjust correction factor needs to be added // Generally speaking: // Code that's protected by the main mDNS lock should just use the m->timenow value // Code outside the main mDNS lock should use mDNS_TimeNow(m) to get properly adjusted time // In certain cases there may be reasons why it's necessary to get the time without taking the lock first // (e.g. inside the routines that are doing the locking and unlocking, where a call to get the lock would result in a // recursive loop); in these cases use mDNS_TimeNow_NoLock(m) to get mDNSPlatformRawTime with the proper correction factor added. // // mDNSPlatformUTC returns the time, in seconds, since Jan 1st 1970 UTC and is required for generating TSIG records #ifdef MDNS_MALLOC_DEBUGGING typedef void mDNSListValidationFunction(void *); typedef struct listValidator mDNSListValidator; struct listValidator { struct listValidator *next; const char *validationFunctionName; mDNSListValidationFunction *validator; void *context; }; #endif // MDNS_MALLOC_DEBUGGING extern mStatus mDNSPlatformInit (mDNS *const m); extern void mDNSPlatformClose (mDNS *const m); extern mStatus mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst, mDNSIPPort dstport, mDNSBool useBackgroundTrafficClass); extern void mDNSPlatformLock (const mDNS *const m); extern void mDNSPlatformUnlock (const mDNS *const m); extern mDNSu32 mDNSPlatformStrLCopy ( void *dst, const void *src, mDNSu32 len); extern mDNSu32 mDNSPlatformStrLen ( const void *src); extern void mDNSPlatformMemCopy ( void *dst, const void *src, mDNSu32 len); extern mDNSBool mDNSPlatformMemSame (const void *dst, const void *src, mDNSu32 len); extern int mDNSPlatformMemCmp (const void *dst, const void *src, mDNSu32 len); extern void mDNSPlatformMemZero ( void *dst, mDNSu32 len); extern void mDNSPlatformQsort (void *base, int nel, int width, int (*compar)(const void *, const void *)); #if MDNS_MALLOC_DEBUGGING #define mDNSPlatformMemAllocate(X) mallocL(# X, X) #define mDNSPlatformMemAllocateClear(X) callocL(# X, X) #define mDNSPlatformMemFree(X) freeL(# X, X) extern void mDNSPlatformValidateLists (void); extern void mDNSPlatformAddListValidator(mDNSListValidator *validator, mDNSListValidationFunction *vf, const char *vfName, void *context); #else extern void * mDNSPlatformMemAllocate(mDNSu32 len); extern void * mDNSPlatformMemAllocateClear(mDNSu32 len); extern void mDNSPlatformMemFree(void *mem); #endif // MDNS_MALLOC_DEBUGGING // If the platform doesn't have a strong PRNG, we define a naive multiply-and-add based on a seed // from the platform layer. Long-term, we should embed an arc4 implementation, but the strength // will still depend on the randomness of the seed. #if !defined(_PLATFORM_HAS_STRONG_PRNG_) && (_BUILDING_XCODE_PROJECT_ || defined(_WIN32)) #define _PLATFORM_HAS_STRONG_PRNG_ 1 #endif #if _PLATFORM_HAS_STRONG_PRNG_ extern mDNSu32 mDNSPlatformRandomNumber(void); #else extern mDNSu32 mDNSPlatformRandomSeed (void); #endif // _PLATFORM_HAS_STRONG_PRNG_ extern mStatus mDNSPlatformTimeInit (void); extern mDNSs32 mDNSPlatformRawTime (void); extern mDNSs32 mDNSPlatformUTC (void); #define mDNS_TimeNow_NoLock(m) (mDNSPlatformRawTime() + (m)->timenow_adjust) #if MDNS_DEBUGMSGS extern void mDNSPlatformWriteDebugMsg(const char *msg); #endif extern void mDNSPlatformWriteLogMsg(const char *ident, const char *msg, mDNSLogLevel_t loglevel); // Platform support modules should provide the following functions to map between opaque interface IDs // and interface indexes in order to support the DNS-SD API. If your target platform does not support // multiple interfaces and/or does not support the DNS-SD API, these functions can be empty. extern mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 ifindex); extern mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id, mDNSBool suppressNetworkChange); // Every platform support module must provide the following functions if it is to support unicast DNS // and Dynamic Update. // All TCP socket operations implemented by the platform layer MUST NOT BLOCK. // mDNSPlatformTCPConnect initiates a TCP connection with a peer, adding the socket descriptor to the // main event loop. The return value indicates whether the connection succeeded, failed, or is pending // (i.e. the call would block.) On return, the descriptor parameter is set to point to the connected socket. // The TCPConnectionCallback is subsequently invoked when the connection // completes (in which case the ConnectionEstablished parameter is true), or data is available for // reading on the socket (indicated by the ConnectionEstablished parameter being false.) If the connection // asynchronously fails, the TCPConnectionCallback should be invoked as usual, with the error being // returned in subsequent calls to PlatformReadTCP or PlatformWriteTCP. (This allows for platforms // with limited asynchronous error detection capabilities.) PlatformReadTCP and PlatformWriteTCP must // return the number of bytes read/written, 0 if the call would block, and -1 if an error. PlatformReadTCP // should set the closed argument if the socket has been closed. // PlatformTCPCloseConnection must close the connection to the peer and remove the descriptor from the // event loop. CloseConnectin may be called at any time, including in a ConnectionCallback. typedef enum { kTCPSocketFlags_Zero = 0, kTCPSocketFlags_UseTLS = (1 << 0) } TCPSocketFlags; typedef void (*TCPConnectionCallback)(TCPSocket *sock, void *context, mDNSBool ConnectionEstablished, mStatus err); typedef void (*TCPAcceptedCallback)(TCPSocket *sock, mDNSAddr *addr, mDNSIPPort *port, const char *remoteName, void *context); extern TCPSocket *mDNSPlatformTCPSocket(TCPSocketFlags flags, mDNSAddr_Type addrtype, mDNSIPPort *port, domainname *hostname, mDNSBool useBackgroundTrafficClass); // creates a TCP socket extern TCPListener *mDNSPlatformTCPListen(mDNSAddr_Type addrtype, mDNSIPPort *port, mDNSAddr *addr, TCPSocketFlags socketFlags, mDNSBool reuseAddr, int queueLength, TCPAcceptedCallback callback, void *context); // Listen on a port extern mStatus mDNSPlatformTCPSocketSetCallback(TCPSocket *sock, TCPConnectionCallback callback, void *context); extern TCPSocket *mDNSPlatformTCPAccept(TCPSocketFlags flags, int sd); extern int mDNSPlatformTCPGetFD(TCPSocket *sock); extern mDNSBool mDNSPlatformTCPWritable(TCPSocket *sock); extern mStatus mDNSPlatformTCPConnect(TCPSocket *sock, const mDNSAddr *dst, mDNSOpaque16 dstport, mDNSInterfaceID InterfaceID, TCPConnectionCallback callback, void *context); extern void mDNSPlatformTCPCloseConnection(TCPSocket *sock); extern long mDNSPlatformReadTCP(TCPSocket *sock, void *buf, unsigned long buflen, mDNSBool *closed); extern long mDNSPlatformWriteTCP(TCPSocket *sock, const char *msg, unsigned long len); extern UDPSocket *mDNSPlatformUDPSocket(const mDNSIPPort requestedport); extern mDNSu16 mDNSPlatformGetUDPPort(UDPSocket *sock); extern void mDNSPlatformUDPClose(UDPSocket *sock); extern mDNSBool mDNSPlatformUDPSocketEncounteredEOF(const UDPSocket *sock); extern void mDNSPlatformReceiveBPF_fd(int fd); extern void mDNSPlatformUpdateProxyList(const mDNSInterfaceID InterfaceID); extern void mDNSPlatformSendRawPacket(const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID); extern void mDNSPlatformSetLocalAddressCacheEntry(const mDNSAddr *const tpa, const mDNSEthAddr *const tha, mDNSInterfaceID InterfaceID); extern void mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst); extern void mDNSPlatformSendKeepalive(mDNSAddr *sadd, mDNSAddr *dadd, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu32 seq, mDNSu32 ack, mDNSu16 win); extern mStatus mDNSPlatformRetrieveTCPInfo(mDNSAddr *laddr, mDNSIPPort *lport, mDNSAddr *raddr, mDNSIPPort *rport, mDNSTCPInfo *mti); extern mStatus mDNSPlatformGetRemoteMacAddr(mDNSAddr *raddr); extern mStatus mDNSPlatformStoreSPSMACAddr(mDNSAddr *spsaddr, char *ifname); extern mStatus mDNSPlatformClearSPSData(void); extern mStatus mDNSPlatformStoreOwnerOptRecord(char *ifname, DNSMessage *msg, int length); // mDNSPlatformTLSSetupCerts/mDNSPlatformTLSTearDownCerts used by dnsextd extern mStatus mDNSPlatformTLSSetupCerts(void); extern void mDNSPlatformTLSTearDownCerts(void); // Platforms that support unicast browsing and dynamic update registration for clients who do not specify a domain // in browse/registration calls must implement these routines to get the "default" browse/registration list. extern mDNSBool mDNSPlatformSetDNSConfig(mDNSBool setservers, mDNSBool setsearch, domainname *const fqdn, DNameListElem **RegDomains, DNameListElem **BrowseDomains, mDNSBool ackConfig); extern mStatus mDNSPlatformGetPrimaryInterface(mDNSAddr *v4, mDNSAddr *v6, mDNSAddr *router); extern void mDNSPlatformDynDNSHostNameStatusChanged(const domainname *const dname, const mStatus status); extern void mDNSPlatformSetAllowSleep(mDNSBool allowSleep, const char *reason); extern void mDNSPlatformPreventSleep(mDNSu32 timeout, const char *reason); extern void mDNSPlatformSendWakeupPacket(mDNSInterfaceID InterfaceID, char *EthAddr, char *IPAddr, int iteration); extern mDNSBool mDNSPlatformInterfaceIsD2D(mDNSInterfaceID InterfaceID); #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) extern mDNSBool mDNSPlatformInterfaceIsAWDL(mDNSInterfaceID interfaceID); #endif extern mDNSBool mDNSPlatformValidRecordForQuestion(const ResourceRecord *const rr, const DNSQuestion *const q); extern mDNSBool mDNSPlatformValidRecordForInterface(const AuthRecord *rr, mDNSInterfaceID InterfaceID); extern mDNSBool mDNSPlatformValidQuestionForInterface(DNSQuestion *q, const NetworkInterfaceInfo *intf); extern void mDNSPlatformFormatTime(unsigned long t, mDNSu8 *buf, int bufsize); // Platform event API #ifdef _LEGACY_NAT_TRAVERSAL_ // Support for legacy NAT traversal protocols, implemented by the platform layer and callable by the core. extern void LNT_SendDiscoveryMsg(mDNS *m); extern void LNT_ConfigureRouterInfo(mDNS *m, const mDNSInterfaceID InterfaceID, const mDNSu8 *const data, const mDNSu16 len); extern mStatus LNT_GetExternalAddress(mDNS *m); extern mStatus LNT_MapPort(mDNS *m, NATTraversalInfo *const n); extern mStatus LNT_UnmapPort(mDNS *m, NATTraversalInfo *const n); extern void LNT_ClearState(mDNS *const m); #endif // _LEGACY_NAT_TRAVERSAL_ // The core mDNS code provides these functions, for the platform support code to call at appropriate times // // mDNS_SetFQDN() is called once on startup (typically from mDNSPlatformInit()) // and then again on each subsequent change of the host name. // // mDNS_RegisterInterface() is used by the platform support layer to inform mDNSCore of what // physical and/or logical interfaces are available for sending and receiving packets. // Typically it is called on startup for each available interface, but register/deregister may be // called again later, on multiple occasions, to inform the core of interface configuration changes. // If set->Advertise is set non-zero, then mDNS_RegisterInterface() also registers the standard // resource records that should be associated with every publicised IP address/interface: // -- Name-to-address records (A/AAAA) // -- Address-to-name records (PTR) // -- Host information (HINFO) // IMPORTANT: The specified mDNSInterfaceID MUST NOT be 0, -1, or -2; these values have special meaning // mDNS_RegisterInterface does not result in the registration of global hostnames via dynamic update - // see mDNS_SetPrimaryInterfaceInfo, mDNS_AddDynDNSHostName, etc. for this purpose. // Note that the set may be deallocated immediately after it is deregistered via mDNS_DeegisterInterface. // // mDNS_RegisterDNS() is used by the platform support layer to provide the core with the addresses of // available domain name servers for unicast queries/updates. RegisterDNS() should be called once for // each name server, typically at startup, or when a new name server becomes available. DeregiterDNS() // must be called whenever a registered name server becomes unavailable. DeregisterDNSList deregisters // all registered servers. mDNS_DNSRegistered() returns true if one or more servers are registered in the core. // // mDNSCoreInitComplete() is called when the platform support layer is finished. // Typically this is at the end of mDNSPlatformInit(), but may be later // (on platforms like OT that allow asynchronous initialization of the networking stack). // // mDNSCoreReceive() is called when a UDP packet is received // // mDNSCoreMachineSleep() is called when the machine sleeps or wakes // (This refers to heavyweight laptop-style sleep/wake that disables network access, // not lightweight second-by-second CPU power management modes.) extern void mDNS_SetFQDN(mDNS *const m); extern void mDNS_ActivateNetWake_internal (mDNS *const m, NetworkInterfaceInfo *set); extern void mDNS_DeactivateNetWake_internal(mDNS *const m, NetworkInterfaceInfo *set); // Attributes that controls the Bonjour operation initiation and response speed for an interface. typedef enum { FastActivation, // For p2p* and DirectLink type interfaces NormalActivation, // For standard interface timing SlowActivation // For flapping interfaces } InterfaceActivationSpeed; extern mStatus mDNS_RegisterInterface (mDNS *const m, NetworkInterfaceInfo *set, InterfaceActivationSpeed probeDelay); extern void mDNS_DeregisterInterface(mDNS *const m, NetworkInterfaceInfo *set, InterfaceActivationSpeed probeDelay); extern void mDNSCoreInitComplete(mDNS *const m, mStatus result); extern void mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern void mDNSCoreReceiveForQuerier(mDNS *m, DNSMessage *msg, const mDNSu8 *end, mdns_querier_t querier, mdns_dns_service_t service); #endif extern CacheRecord *mDNSCheckCacheFlushRecords(mDNS *m, CacheRecord *CacheFlushRecords, mDNSBool id_is_zero, int numAnswers, DNSQuestion *unicastQuestion, CacheRecord *NSECCachePtr, CacheRecord *NSECRecords, mDNSu8 rcode); extern void mDNSCoreRestartQueries(mDNS *const m); extern void mDNSCoreRestartQuestion(mDNS *const m, DNSQuestion *q); extern void mDNSCoreRestartRegistration(mDNS *const m, AuthRecord *rr, int announceCount); typedef void (*FlushCache)(mDNS *const m); typedef void (*CallbackBeforeStartQuery)(mDNS *const m, void *context); extern void mDNSCoreRestartAddressQueries(mDNS *const m, mDNSBool SearchDomainsChanged, FlushCache flushCacheRecords, CallbackBeforeStartQuery beforeQueryStart, void *context); extern mDNSBool mDNSCoreHaveAdvertisedMulticastServices(mDNS *const m); extern void mDNSCoreMachineSleep(mDNS *const m, mDNSBool wake); extern mDNSBool mDNSCoreReadyForSleep(mDNS *m, mDNSs32 now); typedef enum { mDNSNextWakeReason_Null = 0, mDNSNextWakeReason_NATPortMappingRenewal = 1, mDNSNextWakeReason_RecordRegistrationRenewal = 2, mDNSNextWakeReason_UpkeepWake = 3, mDNSNextWakeReason_DHCPLeaseRenewal = 4, mDNSNextWakeReason_SleepProxyRegistrationRetry = 5 } mDNSNextWakeReason; extern mDNSs32 mDNSCoreIntervalToNextWake(mDNS *const m, mDNSs32 now, mDNSNextWakeReason *outReason); extern void mDNSCoreReceiveRawPacket (mDNS *const m, const mDNSu8 *const p, const mDNSu8 *const end, const mDNSInterfaceID InterfaceID); extern mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip); extern CacheRecord *CreateNewCacheEntry(mDNS *const m, const mDNSu32 slot, CacheGroup *cg, mDNSs32 delay, mDNSBool Add, const mDNSAddr *sourceAddress); extern CacheGroup *CacheGroupForName(const mDNS *const m, const mDNSu32 namehash, const domainname *const name); extern void ReleaseCacheRecord(mDNS *const m, CacheRecord *r); extern void ScheduleNextCacheCheckTime(mDNS *const m, const mDNSu32 slot, const mDNSs32 event); extern void SetNextCacheCheckTimeForRecord(mDNS *const m, CacheRecord *const rr); extern void GrantCacheExtensions(mDNS *const m, DNSQuestion *q, mDNSu32 lease); extern void MakeNegativeCacheRecord(mDNS *const m, CacheRecord *const cr, const domainname *const name, const mDNSu32 namehash, const mDNSu16 rrtype, const mDNSu16 rrclass, mDNSu32 ttl_seconds, mDNSInterfaceID InterfaceID, #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_dns_service_t service); #else DNSServer *dnsserver); #endif extern void CompleteDeregistration(mDNS *const m, AuthRecord *rr); extern void AnswerCurrentQuestionWithResourceRecord(mDNS *const m, CacheRecord *const rr, const QC_result AddRecord); extern void AnswerQuestionByFollowingCNAME(mDNS *const m, DNSQuestion *q, ResourceRecord *rr); extern char *InterfaceNameForID(mDNS *const m, const mDNSInterfaceID InterfaceID); #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) extern void DNSServerChangeForQuestion(mDNS *const m, DNSQuestion *q, DNSServer *newServer); #endif extern void ActivateUnicastRegistration(mDNS *const m, AuthRecord *const rr); extern void CheckSuppressUnusableQuestions(mDNS *const m); extern void RetrySearchDomainQuestions(mDNS *const m); extern mDNSBool DomainEnumQuery(const domainname *qname); extern mStatus UpdateKeepaliveRData(mDNS *const m, AuthRecord *rr, NetworkInterfaceInfo *const intf, mDNSBool updateMac, char *ethAddr); extern void UpdateKeepaliveRMACAsync(mDNS *const m, void *context); extern void UpdateRMAC(mDNS *const m, void *context); // Used only in logging to restrict the number of /etc/hosts entries printed extern void FreeEtcHosts(mDNS *const m, AuthRecord *const rr, mStatus result); // exported for using the hash for /etc/hosts AuthRecords extern AuthGroup *AuthGroupForName(AuthHash *r, const mDNSu32 namehash, const domainname *const name); extern AuthGroup *AuthGroupForRecord(AuthHash *r, const ResourceRecord *const rr); extern AuthGroup *InsertAuthRecord(mDNS *const m, AuthHash *r, AuthRecord *rr); extern AuthGroup *RemoveAuthRecord(mDNS *const m, AuthHash *r, AuthRecord *rr); #if APPLE_OSX_mDNSResponder // For now this LocalSleepProxy stuff is specific to Mac OS X. // In the future, if there's demand, we may see if we can abstract it out cleanly into the platform layer extern mStatus ActivateLocalProxy(NetworkInterfaceInfo *const intf, mDNSBool offloadKeepAlivesOnly, mDNSBool *keepaliveOnly); extern mDNSBool SupportsInNICProxy(NetworkInterfaceInfo *const intf); #endif typedef void ProxyCallback (void *socket, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID, void *context); extern void mDNSPlatformInitDNSProxySkts(ProxyCallback *UDPCallback, ProxyCallback *TCPCallback); extern void mDNSPlatformCloseDNSProxySkts(mDNS *const m); extern void mDNSPlatformDisposeProxyContext(void *context); extern mDNSu8 *DNSProxySetAttributes(DNSQuestion *q, DNSMessageHeader *h, DNSMessage *msg, mDNSu8 *start, mDNSu8 *limit); #if APPLE_OSX_mDNSResponder extern void mDNSPlatformGetDNSRoutePolicy(DNSQuestion *q); #endif extern void mDNSPlatformSetSocktOpt(void *sock, mDNSTransport_Type transType, mDNSAddr_Type addrType, const DNSQuestion *q); extern mDNSs32 mDNSPlatformGetPID(void); extern mDNSBool mDNSValidKeepAliveRecord(AuthRecord *rr); extern mDNSBool CacheRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q); #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) extern void GetRandomUUIDLabel(domainlabel *label); extern void GetRandomUUIDLocalHostname(domainname *hostname); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) extern void uDNSMetricsClear(uDNSMetrics *metrics); #endif // *************************************************************************** #if 0 #pragma mark - #pragma mark - Sleep Proxy #endif // Sleep Proxy Server Property Encoding // // Sleep Proxy Servers are advertised using a structured service name, consisting of four // metrics followed by a human-readable name. The metrics assist clients in deciding which // Sleep Proxy Server(s) to use when multiple are available on the network. Each metric // is a two-digit decimal number in the range 10-99. Lower metrics are generally better. // // AA-BB-CC-DD.FF Name // // Metrics: // // AA = Intent // BB = Portability // CC = Marginal Power // DD = Total Power // FF = Features Supported (Currently TCP Keepalive only) // // // ** Intent Metric ** // // 20 = Dedicated Sleep Proxy Server -- a device, permanently powered on, // installed for the express purpose of providing Sleep Proxy Service. // // 30 = Primary Network Infrastructure Hardware -- a router, DHCP server, NAT gateway, // or similar permanently installed device which is permanently powered on. // This is hardware designed for the express purpose of being network // infrastructure, and for most home users is typically a single point // of failure for the local network -- e.g. most home users only have // a single NAT gateway / DHCP server. Even though in principle the // hardware might technically be capable of running different software, // a typical user is unlikely to do that. e.g. AirPort base station. // // 40 = Primary Network Infrastructure Software -- a general-purpose computer // (e.g. Mac, Windows, Linux, etc.) which is currently running DHCP server // or NAT gateway software, but the user could choose to turn that off // fairly easily. e.g. iMac running Internet Sharing // // 50 = Secondary Network Infrastructure Hardware -- like primary infrastructure // hardware, except not a single point of failure for the entire local network. // For example, an AirPort base station in bridge mode. This may have clients // associated with it, and if it goes away those clients will be inconvenienced, // but unlike the NAT gateway / DHCP server, the entire local network is not // dependent on it. // // 60 = Secondary Network Infrastructure Software -- like 50, but in a general- // purpose CPU. // // 70 = Incidentally Available Hardware -- a device which has no power switch // and is generally left powered on all the time. Even though it is not a // part of what we conventionally consider network infrastructure (router, // DHCP, NAT, DNS, etc.), and the rest of the network can operate fine // without it, since it's available and unlikely to be turned off, it is a // reasonable candidate for providing Sleep Proxy Service e.g. Apple TV, // or an AirPort base station in client mode, associated with an existing // wireless network (e.g. AirPort Express connected to a music system, or // being used to share a USB printer). // // 80 = Incidentally Available Software -- a general-purpose computer which // happens at this time to be set to "never sleep", and as such could be // useful as a Sleep Proxy Server, but has not been intentionally provided // for this purpose. Of all the Intent Metric categories this is the // one most likely to be shut down or put to sleep without warning. // However, if nothing else is availalable, it may be better than nothing. // e.g. Office computer in the workplace which has been set to "never sleep" // // // ** Portability Metric ** // // Inversely related to mass of device, on the basis that, all other things // being equal, heavier devices are less likely to be moved than lighter devices. // E.g. A MacBook running Internet Sharing is probably more likely to be // put to sleep and taken away than a Mac Pro running Internet Sharing. // The Portability Metric is a logarithmic decibel scale, computed by taking the // (approximate) mass of the device in milligrammes, taking the base 10 logarithm // of that, multiplying by 10, and subtracting the result from 100: // // Portability Metric = 100 - (log10(mg) * 10) // // The Portability Metric is not necessarily computed literally from the actual // mass of the device; the intent is just that lower numbers indicate more // permanent devices, and higher numbers indicate devices more likely to be // removed from the network, e.g., in order of increasing portability: // // Mac Pro < iMac < Laptop < iPhone // // Example values: // // 10 = 1 metric tonne // 40 = 1kg // 70 = 1g // 90 = 10mg // // // ** Marginal Power and Total Power Metrics ** // // The Marginal Power Metric is the power difference between sleeping and staying awake // to be a Sleep Proxy Server. // // The Total Power Metric is the total power consumption when being Sleep Proxy Server. // // The Power Metrics use a logarithmic decibel scale, computed as ten times the // base 10 logarithm of the (approximate) power in microwatts: // // Power Metric = log10(uW) * 10 // // Higher values indicate higher power consumption. Example values: // // 10 = 10 uW // 20 = 100 uW // 30 = 1 mW // 60 = 1 W // 90 = 1 kW typedef enum { mDNSSleepProxyMetric_Dedicated = 20, mDNSSleepProxyMetric_PrimaryHardware = 30, mDNSSleepProxyMetric_PrimarySoftware = 40, mDNSSleepProxyMetric_SecondaryHardware = 50, mDNSSleepProxyMetric_SecondarySoftware = 60, mDNSSleepProxyMetric_IncidentalHardware = 70, mDNSSleepProxyMetric_IncidentalSoftware = 80 } mDNSSleepProxyMetric; typedef enum { mDNS_NoWake = 0, // System does not support Wake on LAN mDNS_WakeOnAC = 1, // System supports Wake on LAN when connected to AC power only mDNS_WakeOnBattery = 2 // System supports Wake on LAN on battery } mDNSWakeForNetworkAccess; extern void mDNSCoreBeSleepProxyServer_internal(mDNS *const m, mDNSu8 sps, mDNSu8 port, mDNSu8 marginalpower, mDNSu8 totpower, mDNSu8 features); #define mDNSCoreBeSleepProxyServer(M,S,P,MP,TP,F) \ do { mDNS_Lock(m); mDNSCoreBeSleepProxyServer_internal((M),(S),(P),(MP),(TP),(F)); mDNS_Unlock(m); } while(0) extern void FindSPSInCache(mDNS *const m, const DNSQuestion *const q, const CacheRecord *sps[3]); #define PrototypeSPSName(X) ((X)[0] >= 11 && (X)[3] == '-' && (X)[ 4] == '9' && (X)[ 5] == '9' && \ (X)[6] == '-' && (X)[ 7] == '9' && (X)[ 8] == '9' && \ (X)[9] == '-' && (X)[10] == '9' && (X)[11] == '9' ) #define ValidSPSName(X) ((X)[0] >= 5 && mDNSIsDigit((X)[1]) && mDNSIsDigit((X)[2]) && mDNSIsDigit((X)[4]) && mDNSIsDigit((X)[5])) #define SPSMetric(X) (!ValidSPSName(X) || PrototypeSPSName(X) ? 1000000 : \ ((X)[1]-'0') * 100000 + ((X)[2]-'0') * 10000 + ((X)[4]-'0') * 1000 + ((X)[5]-'0') * 100 + ((X)[7]-'0') * 10 + ((X)[8]-'0')) #define LocalSPSMetric(X) ( (X)->SPSType * 10000 + (X)->SPSPortability * 100 + (X)->SPSMarginalPower) #define SPSFeatures(X) ((X)[0] >= 13 && (X)[12] =='.' ? ((X)[13]-'0') : 0 ) #define MD5_DIGEST_LENGTH 16 /* digest length in bytes */ #define MD5_BLOCK_BYTES 64 /* block size in bytes */ #define MD5_BLOCK_LONG (MD5_BLOCK_BYTES / sizeof(mDNSu32)) typedef struct MD5state_st { mDNSu32 A,B,C,D; mDNSu32 Nl,Nh; mDNSu32 data[MD5_BLOCK_LONG]; mDNSu32 num; } MD5_CTX; extern int MD5_Init(MD5_CTX *c); extern int MD5_Update(MD5_CTX *c, const void *data, unsigned long len); extern int MD5_Final(unsigned char *md, MD5_CTX *c); // *************************************************************************** #if 0 #pragma mark - #pragma mark - Compile-Time assertion checks #endif // Some C compiler cleverness. We can make the compiler check certain things for // us, and report compile-time errors if anything is wrong. The usual way to do // this would be to use a run-time "if" statement, but then you don't find out // what's wrong until you run the software. This way, if the assertion condition // is false, the array size is negative, and the complier complains immediately. struct CompileTimeAssertionChecks_mDNS { // Check that the compiler generated our on-the-wire packet format structure definitions // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries. char assert0[(sizeof(rdataSRV) == 262 ) ? 1 : -1]; char assert1[(sizeof(DNSMessageHeader) == 12 ) ? 1 : -1]; char assert2[(sizeof(DNSMessage) == 12+AbsoluteMaxDNSMessageData) ? 1 : -1]; char assert3[(sizeof(mDNSs8) == 1 ) ? 1 : -1]; char assert4[(sizeof(mDNSu8) == 1 ) ? 1 : -1]; char assert5[(sizeof(mDNSs16) == 2 ) ? 1 : -1]; char assert6[(sizeof(mDNSu16) == 2 ) ? 1 : -1]; char assert7[(sizeof(mDNSs32) == 4 ) ? 1 : -1]; char assert8[(sizeof(mDNSu32) == 4 ) ? 1 : -1]; char assert9[(sizeof(mDNSOpaque16) == 2 ) ? 1 : -1]; char assertA[(sizeof(mDNSOpaque32) == 4 ) ? 1 : -1]; char assertB[(sizeof(mDNSOpaque128) == 16 ) ? 1 : -1]; char assertC[(sizeof(CacheRecord ) == sizeof(CacheGroup) ) ? 1 : -1]; char assertD[(sizeof(int) >= 4 ) ? 1 : -1]; char assertE[(StandardAuthRDSize >= 256 ) ? 1 : -1]; char assertF[(sizeof(EthernetHeader) == 14 ) ? 1 : -1]; char assertG[(sizeof(ARP_EthIP ) == 28 ) ? 1 : -1]; char assertH[(sizeof(IPv4Header ) == 20 ) ? 1 : -1]; char assertI[(sizeof(IPv6Header ) == 40 ) ? 1 : -1]; char assertJ[(sizeof(IPv6NDP ) == 24 ) ? 1 : -1]; char assertK[(sizeof(UDPHeader ) == 8 ) ? 1 : -1]; char assertL[(sizeof(IKEHeader ) == 28 ) ? 1 : -1]; char assertM[(sizeof(TCPHeader ) == 20 ) ? 1 : -1]; char assertN[(sizeof(rdataOPT) == 24 ) ? 1 : -1]; char assertP[(sizeof(PCPMapRequest) == 60 ) ? 1 : -1]; char assertQ[(sizeof(PCPMapReply) == 60 ) ? 1 : -1]; // Check our structures are reasonable sizes. Including overly-large buffers, or embedding // other overly-large structures instead of having a pointer to them, can inadvertently // cause structure sizes (and therefore memory usage) to balloon unreasonably. char sizecheck_RDataBody [(sizeof(RDataBody) == 264) ? 1 : -1]; char sizecheck_ResourceRecord [(sizeof(ResourceRecord) <= 72) ? 1 : -1]; char sizecheck_AuthRecord [(sizeof(AuthRecord) <= 1176) ? 1 : -1]; char sizecheck_CacheRecord [(sizeof(CacheRecord) <= 232) ? 1 : -1]; char sizecheck_CacheGroup [(sizeof(CacheGroup) <= 232) ? 1 : -1]; char sizecheck_DNSQuestion [(sizeof(DNSQuestion) <= 1216) ? 1 : -1]; char sizecheck_ZoneData [(sizeof(ZoneData) <= 2048) ? 1 : -1]; char sizecheck_NATTraversalInfo [(sizeof(NATTraversalInfo) <= 200) ? 1 : -1]; char sizecheck_HostnameInfo [(sizeof(HostnameInfo) <= 3050) ? 1 : -1]; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) char sizecheck_DNSServer [(sizeof(DNSServer) <= 328) ? 1 : -1]; #endif char sizecheck_NetworkInterfaceInfo[(sizeof(NetworkInterfaceInfo) <= 9000) ? 1 : -1]; char sizecheck_ServiceRecordSet [(sizeof(ServiceRecordSet) <= 4760) ? 1 : -1]; char sizecheck_DomainAuthInfo [(sizeof(DomainAuthInfo) <= 944) ? 1 : -1]; #if APPLE_OSX_mDNSResponder char sizecheck_ClientTunnel [(sizeof(ClientTunnel) <= 1560) ? 1 : -1]; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) // structure size is assumed by LogRedact routine. char sizecheck_mDNSAddr [(sizeof(mDNSAddr) == 20) ? 1 : -1]; char sizecheck_mDNSv4Addr [(sizeof(mDNSv4Addr) == 4) ? 1 : -1]; char sizecheck_mDNSv6Addr [(sizeof(mDNSv6Addr) == 16) ? 1 : -1]; #endif }; // Routine to initialize device-info TXT record contents mDNSu32 initializeDeviceInfoTXT(mDNS *m, mDNSu8 *ptr); // *************************************************************************** #ifdef __cplusplus } #endif #endif /* * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * To Do: * Elimate all mDNSPlatformMemAllocate/mDNSPlatformMemFree from this code -- the core code * is supposed to be malloc-free so that it runs in constant memory determined at compile-time. * Any dynamic run-time requirements should be handled by the platform layer below or client layer above */ #include "uDNS.h" #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) #include "Metrics.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) #include "SymptomReporter.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) #include "QuerierSupport.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #include "dnssec_v2.h" #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #if (defined(_MSC_VER)) // Disable "assignment within conditional expression". // Other compilers understand the convention that if you place the assignment expression within an extra pair // of parentheses, this signals to the compiler that you really intended an assignment and no warning is necessary. // The Microsoft compiler doesn't understand this convention, so in the absense of any other way to signal // to the compiler that the assignment is intentional, we have to just turn this warning off completely. #pragma warning(disable:4706) #endif // For domain enumeration and automatic browsing // This is the user's DNS search list. // In each of these domains we search for our special pointer records (lb._dns-sd._udp., etc.) // to discover recommended domains for domain enumeration (browse, default browse, registration, // default registration) and possibly one or more recommended automatic browsing domains. mDNSexport SearchListElem *SearchList = mDNSNULL; // The value can be set to true by the Platform code e.g., MacOSX uses the plist mechanism mDNSBool StrictUnicastOrdering = mDNSfalse; extern mDNS mDNSStorage; // We keep track of the number of unicast DNS servers and log a message when we exceed 64. // Currently the unicast queries maintain a 128 bit map to track the valid DNS servers for that // question. Bit position is the index into the DNS server list. This is done so to try all // the servers exactly once before giving up. If we could allocate memory in the core, then // arbitrary limitation of 128 DNSServers can be removed. #define MAX_UNICAST_DNS_SERVERS 128 #define SetNextuDNSEvent(m, rr) { \ if ((m)->NextuDNSEvent - ((rr)->LastAPTime + (rr)->ThisAPInterval) >= 0) \ (m)->NextuDNSEvent = ((rr)->LastAPTime + (rr)->ThisAPInterval); \ } #ifndef UNICAST_DISABLED // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - General Utility Functions #endif // set retry timestamp for record with exponential backoff mDNSlocal void SetRecordRetry(mDNS *const m, AuthRecord *rr, mDNSu32 random) { rr->LastAPTime = m->timenow; if (rr->expire && rr->refreshCount < MAX_UPDATE_REFRESH_COUNT) { mDNSs32 remaining = rr->expire - m->timenow; rr->refreshCount++; if (remaining > MIN_UPDATE_REFRESH_TIME) { // Refresh at 70% + random (currently it is 0 to 10%) rr->ThisAPInterval = 7 * (remaining/10) + (random ? random : mDNSRandom(remaining/10)); // Don't update more often than 5 minutes if (rr->ThisAPInterval < MIN_UPDATE_REFRESH_TIME) rr->ThisAPInterval = MIN_UPDATE_REFRESH_TIME; LogInfo("SetRecordRetry refresh in %d of %d for %s", rr->ThisAPInterval/mDNSPlatformOneSecond, (rr->expire - m->timenow)/mDNSPlatformOneSecond, ARDisplayString(m, rr)); } else { rr->ThisAPInterval = MIN_UPDATE_REFRESH_TIME; LogInfo("SetRecordRetry clamping to min refresh in %d of %d for %s", rr->ThisAPInterval/mDNSPlatformOneSecond, (rr->expire - m->timenow)/mDNSPlatformOneSecond, ARDisplayString(m, rr)); } return; } rr->expire = 0; rr->ThisAPInterval = rr->ThisAPInterval * QuestionIntervalStep; // Same Retry logic as Unicast Queries if (rr->ThisAPInterval < INIT_RECORD_REG_INTERVAL) rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; if (rr->ThisAPInterval > MAX_RECORD_REG_INTERVAL) rr->ThisAPInterval = MAX_RECORD_REG_INTERVAL; LogInfo("SetRecordRetry retry in %d ms for %s", rr->ThisAPInterval, ARDisplayString(m, rr)); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Name Server List Management #endif #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSexport DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *domain, const mDNSInterfaceID interface, const mDNSs32 serviceID, const mDNSAddr *addr, const mDNSIPPort port, ScopeType scopeType, mDNSu32 timeout, mDNSBool isCell, mDNSBool isExpensive, mDNSBool isConstrained, mDNSBool isCLAT46, mDNSu32 resGroupID, mDNSBool usableA, mDNSBool usableAAAA, mDNSBool reqDO) { DNSServer **p; DNSServer *server; int dnsCount = CountOfUnicastDNSServers(m); if (dnsCount >= MAX_UNICAST_DNS_SERVERS) { LogMsg("mDNS_AddDNSServer: DNS server count of %d reached, not adding this server", dnsCount); return mDNSNULL; } if (!domain) domain = (const domainname *)""; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "mDNS_AddDNSServer(%d): Adding " PRI_IP_ADDR " for " PRI_DM_NAME " interface " PUB_S " (%p), serviceID %u, " "scopeType %d, resGroupID %u" PUB_S PUB_S PUB_S PUB_S PUB_S PUB_S PUB_S, dnsCount + 1, addr, DM_NAME_PARAM(domain), InterfaceNameForID(&mDNSStorage, interface), interface, serviceID, (int)scopeType, resGroupID, usableA ? ", usableA" : "", usableAAAA ? ", usableAAAA" : "", isCell ? ", cell" : "", isExpensive ? ", expensive" : "", isConstrained ? ", constrained" : "", isCLAT46 ? ", CLAT46" : "", reqDO ? ", reqDO" : ""); // Scan our existing list to see if we already have a matching record for this DNS resolver for (p = &m->DNSServers; (server = *p) != mDNSNULL; p = &server->next) { if (server->interface != interface) continue; if (server->serviceID != serviceID) continue; if (!mDNSSameAddress(&server->addr, addr)) continue; if (!mDNSSameIPPort(server->port, port)) continue; if (!SameDomainName(&server->domain, domain)) continue; if (server->scopeType != scopeType) continue; if (server->timeout != timeout) continue; if (!server->usableA != !usableA) continue; if (!server->usableAAAA != !usableAAAA) continue; if (!server->isCell != !isCell) continue; if (!(server->flags & DNSServerFlag_Delete)) { debugf("Note: DNS Server %#a:%d for domain %##s (%p) registered more than once", addr, mDNSVal16(port), domain->c, interface); } // If we found a matching record, cut it from the list // (and if we’re *not* resurrecting a record that was marked for deletion, it’s a duplicate, // and the debugf message signifies that we’re collapsing duplicate entries into one) *p = server->next; server->next = mDNSNULL; break; } // If we broke out because we found an existing matching record, advance our pointer to the end of the list while (*p) { p = &(*p)->next; } if (server) { if (server->flags & DNSServerFlag_Delete) { #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) server->flags &= ~DNSServerFlag_Unreachable; #endif server->flags &= ~DNSServerFlag_Delete; } server->isExpensive = isExpensive; server->isConstrained = isConstrained; server->isCLAT46 = isCLAT46; *p = server; // Append resurrected record at end of list } else { server = (DNSServer *) mDNSPlatformMemAllocateClear(sizeof(*server)); if (!server) { LogMsg("Error: mDNS_AddDNSServer - malloc"); } else { server->interface = interface; server->serviceID = serviceID; server->addr = *addr; server->port = port; server->scopeType = scopeType; server->timeout = timeout; server->usableA = usableA; server->usableAAAA = usableAAAA; server->isCell = isCell; server->isExpensive = isExpensive; server->isConstrained = isConstrained; server->isCLAT46 = isCLAT46; AssignDomainName(&server->domain, domain); *p = server; // Append new record at end of list } } if (server) { server->penaltyTime = 0; // We always update the ID (not just when we allocate a new instance) because we want // all the resGroupIDs for a particular domain to match. server->resGroupID = resGroupID; } return(server); } // PenalizeDNSServer is called when the number of queries to the unicast // DNS server exceeds MAX_UCAST_UNANSWERED_QUERIES or when we receive an // error e.g., SERV_FAIL from DNS server. mDNSexport void PenalizeDNSServer(mDNS *const m, DNSQuestion *q, mDNSOpaque16 responseFlags) { DNSServer *new; DNSServer *orig = q->qDNSServer; mDNSu8 rcode = '\0'; mDNS_CheckLock(m); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Penalizing DNS server " PRI_IP_ADDR " question for question %p " PRI_DM_NAME " (" PUB_S ") SuppressUnusable %d", (q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), q->SuppressUnusable); // If we get error from any DNS server, remember the error. If all of the servers, // return the error, then return the first error. if (mDNSOpaque16IsZero(q->responseFlags)) q->responseFlags = responseFlags; rcode = (mDNSu8)(responseFlags.b[1] & kDNSFlag1_RC_Mask); // After we reset the qDNSServer to NULL, we could get more SERV_FAILS that might end up // penalizing again. if (!q->qDNSServer) goto end; // If strict ordering of unicast servers needs to be preserved, we just lookup // the next best match server below // // If strict ordering is not required which is the default behavior, we penalize the server // for DNSSERVER_PENALTY_TIME. We may also use additional logic e.g., don't penalize for PTR // in the future. if (!StrictUnicastOrdering) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Strict Unicast Ordering is FALSE"); // We penalize the server so that new queries don't pick this server for DNSSERVER_PENALTY_TIME // XXX Include other logic here to see if this server should really be penalized // if (q->qtype == kDNSType_PTR) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Not Penalizing PTR question"); } else if ((rcode == kDNSFlag1_RC_FormErr) || (rcode == kDNSFlag1_RC_ServFail) || (rcode == kDNSFlag1_RC_NotImpl)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Not Penalizing DNS Server since it at least responded with rcode %d", rcode); } else { const char *reason = ""; if (rcode == kDNSFlag1_RC_Refused) { reason = " because server refused to answer"; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Penalizing question type %d" PUB_S, q->qtype, reason); q->qDNSServer->penaltyTime = NonZeroTime(m->timenow + DNSSERVER_PENALTY_TIME); } } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "PenalizeDNSServer: Strict Unicast Ordering is TRUE"); } end: new = GetServerForQuestion(m, q); if (new == orig) { if (new) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "PenalizeDNSServer: ERROR!! GetServerForQuestion returned the same server " PRI_IP_ADDR ":%d", &new->addr, mDNSVal16(new->port)); q->ThisQInterval = 0; // Inactivate this question so that we dont bombard the network } else { // When we have no more DNS servers, we might end up calling PenalizeDNSServer multiple // times when we receive SERVFAIL from delayed packets in the network e.g., DNS server // is slow in responding and we have sent three queries. When we repeatedly call, it is // okay to receive the same NULL DNS server. Next time we try to send the query, we will // realize and re-initialize the DNS servers. LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: GetServerForQuestion returned the same server NULL"); } } else { // The new DNSServer is set in DNSServerChangeForQuestion DNSServerChangeForQuestion(m, q, new); if (new) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Server for " PRI_DM_NAME " (" PUB_S ") changed to " PRI_IP_ADDR ":%d (" PRI_DM_NAME ")", DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), DM_NAME_PARAM(&q->qDNSServer->domain)); // We want to try the next server immediately. As the question may already have backed off, reset // the interval. We do this only the first time when we try all the DNS servers. Once we reached the end of // list and retrying all the servers again e.g., at least one server failed to respond in the previous try, we // use the normal backoff which is done in uDNS_CheckCurrentQuestion when we send the packet out. if (!q->triedAllServersOnce) { q->ThisQInterval = InitialQuestionInterval; q->LastQTime = m->timenow - q->ThisQInterval; SetNextQueryTime(m, q); } } else { // We don't have any more DNS servers for this question. If some server in the list did not return // any response, we need to keep retrying till we get a response. uDNS_CheckCurrentQuestion handles // this case. // // If all servers responded with a negative response, We need to do two things. First, generate a // negative response so that applications get a reply. We also need to reinitialize the DNS servers // so that when the cache expires, we can restart the query. We defer this up until we generate // a negative cache response in uDNS_CheckCurrentQuestion. // // Be careful not to touch the ThisQInterval here. For a normal question, when we answer the question // in AnswerCurrentQuestionWithResourceRecord will set ThisQInterval to MaxQuestionInterval and hence // the next query will not happen until cache expiry. If it is a long lived question, // AnswerCurrentQuestionWithResourceRecord will not set it to MaxQuestionInterval. In that case, // we want the normal backoff to work. LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "PenalizeDNSServer: Server for %p, " PRI_DM_NAME " (" PUB_S ") changed to NULL, Interval %d", q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), q->ThisQInterval); } q->unansweredQueries = 0; } } #endif // !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - authorization management #endif mDNSlocal DomainAuthInfo *GetAuthInfoForName_direct(mDNS *m, const domainname *const name) { const domainname *n = name; while (n->c[0]) { DomainAuthInfo *ptr; for (ptr = m->AuthInfoList; ptr; ptr = ptr->next) if (SameDomainName(&ptr->domain, n)) { debugf("GetAuthInfoForName %##s Matched %##s Key name %##s", name->c, ptr->domain.c, ptr->keyname.c); return(ptr); } n = (const domainname *)(n->c + 1 + n->c[0]); } //LogInfo("GetAuthInfoForName none found for %##s", name->c); return mDNSNULL; } // MUST be called with lock held mDNSexport DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name) { DomainAuthInfo **p = &m->AuthInfoList; mDNS_CheckLock(m); // First purge any dead keys from the list while (*p) { if ((*p)->deltime && m->timenow - (*p)->deltime >= 0) { DNSQuestion *q; DomainAuthInfo *info = *p; LogInfo("GetAuthInfoForName_internal deleting expired key %##s %##s", info->domain.c, info->keyname.c); *p = info->next; // Cut DomainAuthInfo from list *before* scanning our question list updating AuthInfo pointers for (q = m->Questions; q; q=q->next) if (q->AuthInfo == info) { q->AuthInfo = GetAuthInfoForName_direct(m, &q->qname); debugf("GetAuthInfoForName_internal updated q->AuthInfo from %##s to %##s for %##s (%s)", info->domain.c, q->AuthInfo ? q->AuthInfo->domain.c : mDNSNULL, q->qname.c, DNSTypeName(q->qtype)); } // Probably not essential, but just to be safe, zero out the secret key data // so we don't leave it hanging around in memory // (where it could potentially get exposed via some other bug) mDNSPlatformMemZero(info, sizeof(*info)); mDNSPlatformMemFree(info); } else p = &(*p)->next; } return(GetAuthInfoForName_direct(m, name)); } mDNSexport DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name) { DomainAuthInfo *d; mDNS_Lock(m); d = GetAuthInfoForName_internal(m, name); mDNS_Unlock(m); return(d); } // MUST be called with the lock held mDNSexport mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info, const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port) { DNSQuestion *q; DomainAuthInfo **p = &m->AuthInfoList; if (!info || !b64keydata) { LogMsg("mDNS_SetSecretForDomain: ERROR: info %p b64keydata %p", info, b64keydata); return(mStatus_BadParamErr); } LogInfo("mDNS_SetSecretForDomain: domain %##s key %##s", domain->c, keyname->c); AssignDomainName(&info->domain, domain); AssignDomainName(&info->keyname, keyname); if (hostname) AssignDomainName(&info->hostname, hostname); else info->hostname.c[0] = 0; if (port) info->port = *port; else info->port = zeroIPPort; mDNS_snprintf(info->b64keydata, sizeof(info->b64keydata), "%s", b64keydata); if (DNSDigest_ConstructHMACKeyfromBase64(info, b64keydata) < 0) { LogMsg("mDNS_SetSecretForDomain: ERROR: Could not convert shared secret from base64: domain %##s key %##s %s", domain->c, keyname->c, mDNS_LoggingEnabled ? b64keydata : ""); return(mStatus_BadParamErr); } // Don't clear deltime until after we've ascertained that b64keydata is valid info->deltime = 0; while (*p && (*p) != info) p=&(*p)->next; if (*p) {LogInfo("mDNS_SetSecretForDomain: Domain %##s Already in list", (*p)->domain.c); return(mStatus_AlreadyRegistered);} info->next = mDNSNULL; *p = info; // Check to see if adding this new DomainAuthInfo has changed the credentials for any of our questions for (q = m->Questions; q; q=q->next) { DomainAuthInfo *newinfo = GetAuthInfoForQuestion(m, q); if (q->AuthInfo != newinfo) { debugf("mDNS_SetSecretForDomain updating q->AuthInfo from %##s to %##s for %##s (%s)", q->AuthInfo ? q->AuthInfo->domain.c : mDNSNULL, newinfo ? newinfo->domain.c : mDNSNULL, q->qname.c, DNSTypeName(q->qtype)); q->AuthInfo = newinfo; } } return(mStatus_NoError); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - NAT Traversal #endif // Keep track of when to request/refresh the external address using NAT-PMP or UPnP/IGD, // and do so when necessary mDNSlocal mStatus uDNS_RequestAddress(mDNS *m) { mStatus err = mStatus_NoError; if (!m->NATTraversals) { m->retryGetAddr = NonZeroTime(m->timenow + FutureTime); LogInfo("uDNS_RequestAddress: Setting retryGetAddr to future"); } else if (m->timenow - m->retryGetAddr >= 0) { if (mDNSv4AddrIsRFC1918(&m->Router.ip.v4)) { static NATAddrRequest req = {NATMAP_VERS, NATOp_AddrRequest}; static mDNSu8* start = (mDNSu8*)&req; mDNSu8* end = start + sizeof(NATAddrRequest); err = mDNSPlatformSendUDP(m, start, end, 0, mDNSNULL, &m->Router, NATPMPPort, mDNSfalse); debugf("uDNS_RequestAddress: Sent NAT-PMP external address request %d", err); #ifdef _LEGACY_NAT_TRAVERSAL_ if (mDNSIPPortIsZero(m->UPnPRouterPort) || mDNSIPPortIsZero(m->UPnPSOAPPort)) { LNT_SendDiscoveryMsg(m); debugf("uDNS_RequestAddress: LNT_SendDiscoveryMsg"); } else { mStatus lnterr = LNT_GetExternalAddress(m); if (lnterr) LogMsg("uDNS_RequestAddress: LNT_GetExternalAddress returned error %d", lnterr); err = err ? err : lnterr; // NAT-PMP error takes precedence } #endif // _LEGACY_NAT_TRAVERSAL_ } // Always update the interval and retry time, so that even if we fail to send the // packet, we won't spin in an infinite loop repeatedly failing to send the packet if (m->retryIntervalGetAddr < NATMAP_INIT_RETRY) { m->retryIntervalGetAddr = NATMAP_INIT_RETRY; } else if (m->retryIntervalGetAddr < NATMAP_MAX_RETRY_INTERVAL / 2) { m->retryIntervalGetAddr *= 2; } else { m->retryIntervalGetAddr = NATMAP_MAX_RETRY_INTERVAL; } m->retryGetAddr = NonZeroTime(m->timenow + m->retryIntervalGetAddr); } else { debugf("uDNS_RequestAddress: Not time to send address request"); } // Always update NextScheduledNATOp, even if we didn't change retryGetAddr, so we'll // be called when we need to send the request(s) if (m->NextScheduledNATOp - m->retryGetAddr > 0) m->NextScheduledNATOp = m->retryGetAddr; return err; } mDNSlocal mStatus uDNS_SendNATMsg(mDNS *m, NATTraversalInfo *info, mDNSBool usePCP, mDNSBool unmapping) { mStatus err = mStatus_NoError; if (!info) { LogMsg("uDNS_SendNATMsg called unexpectedly with NULL info"); return mStatus_BadParamErr; } // send msg if the router's address is private (which means it's non-zero) if (mDNSv4AddrIsRFC1918(&m->Router.ip.v4)) { if (!usePCP) { if (!info->sentNATPMP) { if (info->Protocol) { static NATPortMapRequest NATPortReq; static const mDNSu8* end = (mDNSu8 *)&NATPortReq + sizeof(NATPortMapRequest); mDNSu8 *p = (mDNSu8 *)&NATPortReq.NATReq_lease; NATPortReq.vers = NATMAP_VERS; NATPortReq.opcode = info->Protocol; NATPortReq.unused = zeroID; NATPortReq.intport = info->IntPort; NATPortReq.extport = info->RequestedPort; p[0] = (mDNSu8)((info->NATLease >> 24) & 0xFF); p[1] = (mDNSu8)((info->NATLease >> 16) & 0xFF); p[2] = (mDNSu8)((info->NATLease >> 8) & 0xFF); p[3] = (mDNSu8)( info->NATLease & 0xFF); err = mDNSPlatformSendUDP(m, (mDNSu8 *)&NATPortReq, end, 0, mDNSNULL, &m->Router, NATPMPPort, mDNSfalse); debugf("uDNS_SendNATMsg: Sent NAT-PMP mapping request %d", err); } // In case the address request already went out for another NAT-T, // set the NewAddress to the currently known global external address, so // Address-only operations will get the callback immediately info->NewAddress = m->ExtAddress; // Remember that we just sent a NAT-PMP packet, so we won't resend one later. // We do this because the NAT-PMP "Unsupported Version" response has no // information about the (PCP) request that triggered it, so we must send // NAT-PMP requests for all operations. Without this, we'll send n PCP // requests for n operations, receive n NAT-PMP "Unsupported Version" // responses, and send n NAT-PMP requests for each of those responses, // resulting in (n + n^2) packets sent. We only want to send 2n packets: // n PCP requests followed by n NAT-PMP requests. info->sentNATPMP = mDNStrue; } } else { PCPMapRequest req; mDNSu8* start = (mDNSu8*)&req; mDNSu8* end = start + sizeof(req); mDNSu8* p = (mDNSu8*)&req.lifetime; req.version = PCP_VERS; req.opCode = PCPOp_Map; req.reserved = zeroID; p[0] = (mDNSu8)((info->NATLease >> 24) & 0xFF); p[1] = (mDNSu8)((info->NATLease >> 16) & 0xFF); p[2] = (mDNSu8)((info->NATLease >> 8) & 0xFF); p[3] = (mDNSu8)( info->NATLease & 0xFF); mDNSAddrMapIPv4toIPv6(&m->AdvertisedV4.ip.v4, &req.clientAddr); req.nonce[0] = m->PCPNonce[0]; req.nonce[1] = m->PCPNonce[1]; req.nonce[2] = m->PCPNonce[2]; req.protocol = (info->Protocol == NATOp_MapUDP ? PCPProto_UDP : PCPProto_TCP); req.reservedMapOp[0] = 0; req.reservedMapOp[1] = 0; req.reservedMapOp[2] = 0; req.intPort = info->Protocol ? info->IntPort : DiscardPort; req.extPort = info->RequestedPort; // Since we only support IPv4, even if using the all-zeros address, map it, so // the PCP gateway will give us an IPv4 address & not an IPv6 address. mDNSAddrMapIPv4toIPv6(&info->NewAddress, &req.extAddress); err = mDNSPlatformSendUDP(m, start, end, 0, mDNSNULL, &m->Router, NATPMPPort, mDNSfalse); debugf("uDNS_SendNATMsg: Sent PCP Mapping request %d", err); // Unset the sentNATPMP flag, so that we'll send a NAT-PMP packet if we // receive a NAT-PMP "Unsupported Version" packet. This will result in every // renewal, retransmission, etc. being tried first as PCP, then if a NAT-PMP // "Unsupported Version" response is received, fall-back & send the request // using NAT-PMP. info->sentNATPMP = mDNSfalse; #ifdef _LEGACY_NAT_TRAVERSAL_ // If an unmapping is being performed, then don't send an LNT discovery message or an LNT port map request. if (!unmapping) { if (mDNSIPPortIsZero(m->UPnPRouterPort) || mDNSIPPortIsZero(m->UPnPSOAPPort)) { LNT_SendDiscoveryMsg(m); debugf("uDNS_SendNATMsg: LNT_SendDiscoveryMsg"); } else { mStatus lnterr = LNT_MapPort(m, info); if (lnterr) LogMsg("uDNS_SendNATMsg: LNT_MapPort returned error %d", lnterr); err = err ? err : lnterr; // PCP error takes precedence } } #else (void)unmapping; // Unused #endif // _LEGACY_NAT_TRAVERSAL_ } } return(err); } mDNSexport void RecreateNATMappings(mDNS *const m, const mDNSu32 waitTicks) { mDNSu32 when = NonZeroTime(m->timenow + waitTicks); NATTraversalInfo *n; for (n = m->NATTraversals; n; n=n->next) { n->ExpiryTime = 0; // Mark this mapping as expired n->retryInterval = NATMAP_INIT_RETRY; n->retryPortMap = when; n->lastSuccessfulProtocol = NATTProtocolNone; if (!n->Protocol) n->NewResult = mStatus_NoError; #ifdef _LEGACY_NAT_TRAVERSAL_ if (n->tcpInfo.sock) { mDNSPlatformTCPCloseConnection(n->tcpInfo.sock); n->tcpInfo.sock = mDNSNULL; } #endif // _LEGACY_NAT_TRAVERSAL_ } m->PCPNonce[0] = mDNSRandom(-1); m->PCPNonce[1] = mDNSRandom(-1); m->PCPNonce[2] = mDNSRandom(-1); m->retryIntervalGetAddr = 0; m->retryGetAddr = when; #ifdef _LEGACY_NAT_TRAVERSAL_ LNT_ClearState(m); #endif // _LEGACY_NAT_TRAVERSAL_ m->NextScheduledNATOp = m->timenow; // Need to send packets immediately } mDNSexport void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr) { static mDNSu16 last_err = 0; NATTraversalInfo *n; if (err) { if (err != last_err) LogMsg("Error getting external address %d", err); ExtAddr = zerov4Addr; } else { LogInfo("Received external IP address %.4a from NAT", &ExtAddr); if (mDNSv4AddrIsRFC1918(&ExtAddr)) LogMsg("Double NAT (external NAT gateway address %.4a is also a private RFC 1918 address)", &ExtAddr); if (mDNSIPv4AddressIsZero(ExtAddr)) err = NATErr_NetFail; // fake error to handle routers that pathologically report success with the zero address } // Globally remember the most recently discovered address, so it can be used in each // new NATTraversal structure m->ExtAddress = ExtAddr; if (!err) // Success, back-off to maximum interval m->retryIntervalGetAddr = NATMAP_MAX_RETRY_INTERVAL; else if (!last_err) // Failure after success, retry quickly (then back-off exponentially) m->retryIntervalGetAddr = NATMAP_INIT_RETRY; // else back-off normally in case of pathological failures m->retryGetAddr = m->timenow + m->retryIntervalGetAddr; if (m->NextScheduledNATOp - m->retryGetAddr > 0) m->NextScheduledNATOp = m->retryGetAddr; last_err = err; for (n = m->NATTraversals; n; n=n->next) { // We should change n->NewAddress only when n is one of: // 1) a mapping operation that most recently succeeded using NAT-PMP or UPnP/IGD, // because such an operation needs the update now. If the lastSuccessfulProtocol // is currently none, then natTraversalHandlePortMapReplyWithAddress() will be // called should NAT-PMP or UPnP/IGD succeed in the future. // 2) an address-only operation that did not succeed via PCP, because when such an // operation succeeds via PCP, it's for the TCP discard port just to learn the // address. And that address may be different than the external address // discovered via NAT-PMP or UPnP/IGD. If the lastSuccessfulProtocol // is currently none, we must update the NewAddress as PCP may not succeed. if (!mDNSSameIPv4Address(n->NewAddress, ExtAddr) && (n->Protocol ? (n->lastSuccessfulProtocol == NATTProtocolNATPMP || n->lastSuccessfulProtocol == NATTProtocolUPNPIGD) : (n->lastSuccessfulProtocol != NATTProtocolPCP))) { // Needs an update immediately n->NewAddress = ExtAddr; n->ExpiryTime = 0; n->retryInterval = NATMAP_INIT_RETRY; n->retryPortMap = m->timenow; #ifdef _LEGACY_NAT_TRAVERSAL_ if (n->tcpInfo.sock) { mDNSPlatformTCPCloseConnection(n->tcpInfo.sock); n->tcpInfo.sock = mDNSNULL; } #endif // _LEGACY_NAT_TRAVERSAL_ m->NextScheduledNATOp = m->timenow; // Need to send packets immediately } } } // Both places that call NATSetNextRenewalTime() update m->NextScheduledNATOp correctly afterwards mDNSlocal void NATSetNextRenewalTime(mDNS *const m, NATTraversalInfo *n) { n->retryInterval = (n->ExpiryTime - m->timenow)/2; if (n->retryInterval < NATMAP_MIN_RETRY_INTERVAL) // Min retry interval is 2 seconds n->retryInterval = NATMAP_MIN_RETRY_INTERVAL; n->retryPortMap = m->timenow + n->retryInterval; } mDNSlocal void natTraversalHandlePortMapReplyWithAddress(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSv4Addr extaddr, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol) { const char *prot = n->Protocol == 0 ? "Add" : n->Protocol == NATOp_MapUDP ? "UDP" : n->Protocol == NATOp_MapTCP ? "TCP" : "???"; (void)prot; n->NewResult = err; if (err || lease == 0 || mDNSIPPortIsZero(extport)) { LogInfo("natTraversalHandlePortMapReplyWithAddress: %p Response %s Port %5d External %.4a:%d lease %d error %d", n, prot, mDNSVal16(n->IntPort), &extaddr, mDNSVal16(extport), lease, err); n->retryInterval = NATMAP_MAX_RETRY_INTERVAL; n->retryPortMap = m->timenow + NATMAP_MAX_RETRY_INTERVAL; // No need to set m->NextScheduledNATOp here, since we're only ever extending the m->retryPortMap time if (err == NATErr_Refused) n->NewResult = mStatus_NATPortMappingDisabled; else if (err > NATErr_None && err <= NATErr_Opcode) n->NewResult = mStatus_NATPortMappingUnsupported; } else { if (lease > 999999999UL / mDNSPlatformOneSecond) lease = 999999999UL / mDNSPlatformOneSecond; n->ExpiryTime = NonZeroTime(m->timenow + lease * mDNSPlatformOneSecond); if (!mDNSSameIPv4Address(n->NewAddress, extaddr) || !mDNSSameIPPort(n->RequestedPort, extport)) LogInfo("natTraversalHandlePortMapReplyWithAddress: %p %s Response %s Port %5d External %.4a:%d changed to %.4a:%d lease %d", n, (n->lastSuccessfulProtocol == NATTProtocolNone ? "None " : n->lastSuccessfulProtocol == NATTProtocolNATPMP ? "NAT-PMP " : n->lastSuccessfulProtocol == NATTProtocolUPNPIGD ? "UPnP/IGD" : n->lastSuccessfulProtocol == NATTProtocolPCP ? "PCP " : /* else */ "Unknown " ), prot, mDNSVal16(n->IntPort), &n->NewAddress, mDNSVal16(n->RequestedPort), &extaddr, mDNSVal16(extport), lease); n->InterfaceID = InterfaceID; n->NewAddress = extaddr; if (n->Protocol) n->RequestedPort = extport; // Don't report the (PCP) external port to address-only operations n->lastSuccessfulProtocol = protocol; NATSetNextRenewalTime(m, n); // Got our port mapping; now set timer to renew it at halfway point m->NextScheduledNATOp = m->timenow; // May need to invoke client callback immediately } } // To be called for NAT-PMP or UPnP/IGD mappings, to use currently discovered (global) address mDNSexport void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol) { natTraversalHandlePortMapReplyWithAddress(m, n, InterfaceID, err, m->ExtAddress, extport, lease, protocol); } // Must be called with the mDNS_Lock held mDNSexport mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal) { NATTraversalInfo **n; LogInfo("mDNS_StartNATOperation_internal %p Protocol %d IntPort %d RequestedPort %d NATLease %d", traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), mDNSVal16(traversal->RequestedPort), traversal->NATLease); // Note: It important that new traversal requests are appended at the *end* of the list, not prepended at the start for (n = &m->NATTraversals; *n; n=&(*n)->next) { if (traversal == *n) { LogFatalError("Error! Tried to add a NAT traversal that's already in the active list: request %p Prot %d Int %d TTL %d", traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease); return(mStatus_AlreadyRegistered); } if (traversal->Protocol && traversal->Protocol == (*n)->Protocol && mDNSSameIPPort(traversal->IntPort, (*n)->IntPort) && !mDNSSameIPPort(traversal->IntPort, SSHPort)) LogMsg("Warning: Created port mapping request %p Prot %d Int %d TTL %d " "duplicates existing port mapping request %p Prot %d Int %d TTL %d", traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease, *n, (*n)->Protocol, mDNSVal16((*n)->IntPort), (*n)->NATLease); } // Initialize necessary fields traversal->next = mDNSNULL; traversal->ExpiryTime = 0; traversal->retryInterval = NATMAP_INIT_RETRY; traversal->retryPortMap = m->timenow; traversal->NewResult = mStatus_NoError; traversal->lastSuccessfulProtocol = NATTProtocolNone; traversal->sentNATPMP = mDNSfalse; traversal->ExternalAddress = onesIPv4Addr; traversal->NewAddress = zerov4Addr; traversal->ExternalPort = zeroIPPort; traversal->Lifetime = 0; traversal->Result = mStatus_NoError; // set default lease if necessary if (!traversal->NATLease) traversal->NATLease = NATMAP_DEFAULT_LEASE; #ifdef _LEGACY_NAT_TRAVERSAL_ mDNSPlatformMemZero(&traversal->tcpInfo, sizeof(traversal->tcpInfo)); #endif // _LEGACY_NAT_TRAVERSAL_ if (!m->NATTraversals) // If this is our first NAT request, kick off an address request too { m->retryGetAddr = m->timenow; m->retryIntervalGetAddr = NATMAP_INIT_RETRY; } // If this is an address-only operation, initialize to the current global address, // or (in non-PCP environments) we won't know the address until the next external // address request/response. if (!traversal->Protocol) { traversal->NewAddress = m->ExtAddress; } m->NextScheduledNATOp = m->timenow; // This will always trigger sending the packet ASAP, and generate client callback if necessary *n = traversal; // Append new NATTraversalInfo to the end of our list return(mStatus_NoError); } // Must be called with the mDNS_Lock held mDNSexport mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) { mDNSBool unmap = mDNStrue; NATTraversalInfo *p; NATTraversalInfo **ptr = &m->NATTraversals; while (*ptr && *ptr != traversal) ptr=&(*ptr)->next; if (*ptr) *ptr = (*ptr)->next; // If we found it, cut this NATTraversalInfo struct from our list else { LogMsg("mDNS_StopNATOperation_internal: NATTraversalInfo %p not found in list", traversal); return(mStatus_BadReferenceErr); } LogInfo("mDNS_StopNATOperation_internal %p %d %d %d %d", traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), mDNSVal16(traversal->RequestedPort), traversal->NATLease); if (m->CurrentNATTraversal == traversal) m->CurrentNATTraversal = m->CurrentNATTraversal->next; // If there is a match for the operation being stopped, don't send a deletion request (unmap) for (p = m->NATTraversals; p; p=p->next) { if (traversal->Protocol ? ((traversal->Protocol == p->Protocol && mDNSSameIPPort(traversal->IntPort, p->IntPort)) || (!p->Protocol && traversal->Protocol == NATOp_MapTCP && mDNSSameIPPort(traversal->IntPort, DiscardPort))) : (!p->Protocol || (p->Protocol == NATOp_MapTCP && mDNSSameIPPort(p->IntPort, DiscardPort)))) { LogInfo("Warning: Removed port mapping request %p Prot %d Int %d TTL %d " "duplicates existing port mapping request %p Prot %d Int %d TTL %d", traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease, p, p->Protocol, mDNSVal16( p->IntPort), p->NATLease); unmap = mDNSfalse; } } // Even if we DIDN'T make a successful UPnP mapping yet, we might still have a partially-open TCP connection we need to clean up // Before zeroing traversal->RequestedPort below, perform the LNT unmapping, which requires the mapping's external port, // held by the traversal->RequestedPort variable. #ifdef _LEGACY_NAT_TRAVERSAL_ { mStatus err = LNT_UnmapPort(m, traversal); if (err) LogMsg("Legacy NAT Traversal - unmap request failed with error %d", err); } #endif // _LEGACY_NAT_TRAVERSAL_ if (traversal->ExpiryTime && unmap) { traversal->NATLease = 0; traversal->retryInterval = 0; // In case we most recently sent NAT-PMP, we need to set sentNATPMP to false so // that we'll send a NAT-PMP request to destroy the mapping. We do this because // the NATTraversal struct has already been cut from the list, and the client // layer will destroy the memory upon returning from this function, so we can't // try PCP first and then fall-back to NAT-PMP. That is, if we most recently // created/renewed the mapping using NAT-PMP, we need to destroy it using NAT-PMP // now, because we won't get a chance later. traversal->sentNATPMP = mDNSfalse; // Both NAT-PMP & PCP RFCs state that the suggested port in deletion requests // should be zero. And for PCP, the suggested external address should also be // zero, specifically, the all-zeros IPv4-mapped address, since we would only // would have requested an IPv4 address. traversal->RequestedPort = zeroIPPort; traversal->NewAddress = zerov4Addr; uDNS_SendNATMsg(m, traversal, traversal->lastSuccessfulProtocol != NATTProtocolNATPMP, mDNStrue); } return(mStatus_NoError); } mDNSexport mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal) { mStatus status; mDNS_Lock(m); status = mDNS_StartNATOperation_internal(m, traversal); mDNS_Unlock(m); return(status); } mDNSexport mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal) { mStatus status; mDNS_Lock(m); status = mDNS_StopNATOperation_internal(m, traversal); mDNS_Unlock(m); return(status); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Long-Lived Queries #endif // Lock must be held -- otherwise m->timenow is undefined mDNSlocal void StartLLQPolling(mDNS *const m, DNSQuestion *q) { debugf("StartLLQPolling: %##s", q->qname.c); q->state = LLQ_Poll; q->ThisQInterval = INIT_UCAST_POLL_INTERVAL; // We want to send our poll query ASAP, but the "+ 1" is because if we set the time to now, // we risk causing spurious "SendQueries didn't send all its queries" log messages q->LastQTime = m->timenow - q->ThisQInterval + 1; SetNextQueryTime(m, q); } mDNSlocal mDNSu8 *putLLQ(DNSMessage *const msg, mDNSu8 *ptr, const DNSQuestion *const question, const LLQOptData *const data) { AuthRecord rr; ResourceRecord *opt = &rr.resrec; rdataOPT *optRD; //!!!KRS when we implement multiple llqs per message, we'll need to memmove anything past the question section ptr = putQuestion(msg, ptr, msg->data + AbsoluteMaxDNSMessageData, &question->qname, question->qtype, question->qclass); if (!ptr) { LogMsg("ERROR: putLLQ - putQuestion"); return mDNSNULL; } // locate OptRR if it exists, set pointer to end // !!!KRS implement me // format opt rr (fields not specified are zero-valued) mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); opt->rrclass = NormalMaxDNSMessageData; opt->rdlength = sizeof(rdataOPT); // One option in this OPT record opt->rdestimate = sizeof(rdataOPT); optRD = &rr.resrec.rdata->u.opt[0]; optRD->opt = kDNSOpt_LLQ; optRD->u.llq = *data; ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.numAdditionals, opt, 0); if (!ptr) { LogMsg("ERROR: putLLQ - PutResourceRecordTTLJumbo"); return mDNSNULL; } return ptr; } // Normally we'd just request event packets be sent directly to m->LLQNAT.ExternalPort, except... // with LLQs over TLS/TCP we're doing a weird thing where instead of requesting packets be sent to ExternalAddress:ExternalPort // we're requesting that packets be sent to ExternalPort, but at the source address of our outgoing TCP connection. // Normally, after going through the NAT gateway, the source address of our outgoing TCP connection is the same as ExternalAddress, // so this is fine, except when the TCP connection ends up going over a VPN tunnel instead. // To work around this, if we find that the source address for our TCP connection is not a private address, we tell the Dot Mac // LLQ server to send events to us directly at port 5353 on that address, instead of at our mapped external NAT port. mDNSlocal mDNSu16 GetLLQEventPort(const mDNS *const m, const mDNSAddr *const dst) { mDNSAddr src; mDNSPlatformSourceAddrForDest(&src, dst); //LogMsg("GetLLQEventPort: src %#a for dst %#a (%d)", &src, dst, mDNSv4AddrIsRFC1918(&src.ip.v4) ? mDNSVal16(m->LLQNAT.ExternalPort) : 0); return(mDNSv4AddrIsRFC1918(&src.ip.v4) ? mDNSVal16(m->LLQNAT.ExternalPort) : mDNSVal16(MulticastDNSPort)); } // Normally called with llq set. // May be called with llq NULL, when retransmitting a lost Challenge Response mDNSlocal void sendChallengeResponse(mDNS *const m, DNSQuestion *const q, const LLQOptData *llq) { mDNSu8 *responsePtr = m->omsg.data; LLQOptData llqBuf; if (q->tcp) { LogMsg("sendChallengeResponse: ERROR!!: question %##s (%s) tcp non-NULL", q->qname.c, DNSTypeName(q->qtype)); return; } if (q->ntries++ == kLLQ_MAX_TRIES) { LogMsg("sendChallengeResponse: %d failed attempts for LLQ %##s", kLLQ_MAX_TRIES, q->qname.c); StartLLQPolling(m,q); return; } if (!llq) // Retransmission: need to make a new LLQOptData { llqBuf.vers = kLLQ_Vers; llqBuf.llqOp = kLLQOp_Setup; llqBuf.err = LLQErr_NoError; // Don't need to tell server UDP notification port when sending over UDP llqBuf.id = q->id; llqBuf.llqlease = q->ReqLease; llq = &llqBuf; } q->LastQTime = m->timenow; q->ThisQInterval = q->tcp ? 0 : (kLLQ_INIT_RESEND * q->ntries * mDNSPlatformOneSecond); // If using TCP, don't need to retransmit SetNextQueryTime(m, q); // To simulate loss of challenge response packet, uncomment line below //if (q->ntries == 1) return; InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); responsePtr = putLLQ(&m->omsg, responsePtr, q, llq); if (responsePtr) { mStatus err = mDNSSendDNSMessage(m, &m->omsg, responsePtr, mDNSInterface_Any, mDNSNULL, q->LocalSocket, &q->servAddr, q->servPort, mDNSNULL, mDNSfalse); if (err) { LogMsg("sendChallengeResponse: mDNSSendDNSMessage%s failed: %d", q->tcp ? " (TCP)" : "", err); } } else StartLLQPolling(m,q); } mDNSlocal void SetLLQTimer(mDNS *const m, DNSQuestion *const q, const LLQOptData *const llq) { mDNSs32 lease = (mDNSs32)llq->llqlease * mDNSPlatformOneSecond; q->ReqLease = llq->llqlease; q->LastQTime = m->timenow; q->expire = m->timenow + lease; q->ThisQInterval = lease/2 + mDNSRandom(lease/10); debugf("SetLLQTimer setting %##s (%s) to %d %d", q->qname.c, DNSTypeName(q->qtype), lease/mDNSPlatformOneSecond, q->ThisQInterval/mDNSPlatformOneSecond); SetNextQueryTime(m, q); } mDNSlocal void recvSetupResponse(mDNS *const m, mDNSu8 rcode, DNSQuestion *const q, const LLQOptData *const llq) { if (rcode && rcode != kDNSFlag1_RC_NXDomain) { LogMsg("ERROR: recvSetupResponse %##s (%s) - rcode && rcode != kDNSFlag1_RC_NXDomain", q->qname.c, DNSTypeName(q->qtype)); return; } if (llq->llqOp != kLLQOp_Setup) { LogMsg("ERROR: recvSetupResponse %##s (%s) - bad op %d", q->qname.c, DNSTypeName(q->qtype), llq->llqOp); return; } if (llq->vers != kLLQ_Vers) { LogMsg("ERROR: recvSetupResponse %##s (%s) - bad vers %d", q->qname.c, DNSTypeName(q->qtype), llq->vers); return; } if (q->state == LLQ_InitialRequest) { //LogInfo("Got LLQ_InitialRequest"); if (llq->err) { LogMsg("recvSetupResponse - received llq->err %d from server", llq->err); StartLLQPolling(m,q); return; } if (q->ReqLease != llq->llqlease) debugf("recvSetupResponse: requested lease %lu, granted lease %lu", q->ReqLease, llq->llqlease); // cache expiration in case we go to sleep before finishing setup q->ReqLease = llq->llqlease; q->expire = m->timenow + ((mDNSs32)llq->llqlease * mDNSPlatformOneSecond); // update state q->state = LLQ_SecondaryRequest; q->id = llq->id; q->ntries = 0; // first attempt to send response sendChallengeResponse(m, q, llq); } else if (q->state == LLQ_SecondaryRequest) { if (llq->err) { LogMsg("ERROR: recvSetupResponse %##s (%s) code %d from server", q->qname.c, DNSTypeName(q->qtype), llq->err); StartLLQPolling(m,q); return; } if (!mDNSSameOpaque64(&q->id, &llq->id)) { LogMsg("recvSetupResponse - ID changed. discarding"); return; } // this can happen rarely (on packet loss + reordering) q->state = LLQ_Established; q->ntries = 0; SetLLQTimer(m, q, llq); } } mDNSexport uDNS_LLQType uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion) { DNSQuestion pktQ, *q; if (msg->h.numQuestions && getQuestion(msg, msg->data, end, 0, &pktQ)) { const rdataOPT *opt = GetLLQOptData(m, msg, end); for (q = m->Questions; q; q = q->next) { if (!mDNSOpaque16IsZero(q->TargetQID) && q->LongLived && q->qtype == pktQ.qtype && q->qnamehash == pktQ.qnamehash && SameDomainName(&q->qname, &pktQ.qname)) { debugf("uDNS_recvLLQResponse found %##s (%s) %d %#a %#a %X %X %X %X %d", q->qname.c, DNSTypeName(q->qtype), q->state, srcaddr, &q->servAddr, opt ? opt->u.llq.id.l[0] : 0, opt ? opt->u.llq.id.l[1] : 0, q->id.l[0], q->id.l[1], opt ? opt->u.llq.llqOp : 0); if (q->state == LLQ_Poll) debugf("uDNS_LLQ_Events: q->state == LLQ_Poll msg->h.id %d q->TargetQID %d", mDNSVal16(msg->h.id), mDNSVal16(q->TargetQID)); if (q->state == LLQ_Poll && mDNSSameOpaque16(msg->h.id, q->TargetQID)) { m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it // Don't reset the state to IntialRequest as we may write that to the dynamic store // and PrefPane might wrongly think that we are "Starting" instead of "Polling". If // we are in polling state because of PCP/NAT-PMP disabled or DoubleNAT, next LLQNATCallback // would kick us back to LLQInitialRequest. So, resetting the state here may not be useful. // // If we have a good NAT (neither PCP/NAT-PMP disabled nor Double-NAT), then we should not be // possibly in polling state. To be safe, we want to retry from the start in that case // as there may not be another LLQNATCallback // // NOTE: We can be in polling state if we cannot resolve the SOA record i.e, servAddr is set to // all ones. In that case, we would set it in LLQ_InitialRequest as it overrides the PCP/NAT-PMP or // Double-NAT state. if (!mDNSAddressIsOnes(&q->servAddr) && !mDNSIPPortIsZero(m->LLQNAT.ExternalPort) && !m->LLQNAT.Result) { debugf("uDNS_recvLLQResponse got poll response; moving to LLQ_InitialRequest for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); q->state = LLQ_InitialRequest; } q->servPort = zeroIPPort; // Clear servPort so that startLLQHandshake will retry the GetZoneData processing q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry LLQ setup in approx 15 minutes q->LastQTime = m->timenow; SetNextQueryTime(m, q); *matchQuestion = q; return uDNS_LLQ_Entire; // uDNS_LLQ_Entire means flush stale records; assume a large effective TTL } // Note: In LLQ Event packets, the msg->h.id does not match our q->TargetQID, because in that case the msg->h.id nonce is selected by the server else if (opt && q->state == LLQ_Established && opt->u.llq.llqOp == kLLQOp_Event && mDNSSameOpaque64(&opt->u.llq.id, &q->id)) { mDNSu8 *ackEnd; //debugf("Sending LLQ ack for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); InitializeDNSMessage(&m->omsg.h, msg->h.id, ResponseFlags); ackEnd = putLLQ(&m->omsg, m->omsg.data, q, &opt->u.llq); if (ackEnd) mDNSSendDNSMessage(m, &m->omsg, ackEnd, mDNSInterface_Any, mDNSNULL, q->LocalSocket, srcaddr, srcport, mDNSNULL, mDNSfalse); m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it debugf("uDNS_LLQ_Events: q->state == LLQ_Established msg->h.id %d q->TargetQID %d", mDNSVal16(msg->h.id), mDNSVal16(q->TargetQID)); *matchQuestion = q; return uDNS_LLQ_Events; } if (opt && mDNSSameOpaque16(msg->h.id, q->TargetQID)) { if (q->state == LLQ_Established && opt->u.llq.llqOp == kLLQOp_Refresh && mDNSSameOpaque64(&opt->u.llq.id, &q->id) && msg->h.numAdditionals && !msg->h.numAnswers) { if (opt->u.llq.err != LLQErr_NoError) LogMsg("recvRefreshReply: received error %d from server", opt->u.llq.err); else { //LogInfo("Received refresh confirmation ntries %d for %##s (%s)", q->ntries, q->qname.c, DNSTypeName(q->qtype)); // If we're waiting to go to sleep, then this LLQ deletion may have been the thing // we were waiting for, so schedule another check to see if we can sleep now. if (opt->u.llq.llqlease == 0 && m->SleepLimit) m->NextScheduledSPRetry = m->timenow; GrantCacheExtensions(m, q, opt->u.llq.llqlease); SetLLQTimer(m, q, &opt->u.llq); q->ntries = 0; } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it *matchQuestion = q; return uDNS_LLQ_Ignore; } if (q->state < LLQ_Established && mDNSSameAddress(srcaddr, &q->servAddr)) { LLQ_State oldstate = q->state; recvSetupResponse(m, msg->h.flags.b[1] & kDNSFlag1_RC_Mask, q, &opt->u.llq); m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it // We have a protocol anomaly here in the LLQ definition. // Both the challenge packet from the server and the ack+answers packet have opt->u.llq.llqOp == kLLQOp_Setup. // However, we need to treat them differently: // The challenge packet has no answers in it, and tells us nothing about whether our cache entries // are still valid, so this packet should not cause us to do anything that messes with our cache. // The ack+answers packet gives us the whole truth, so we should handle it by updating our cache // to match the answers in the packet, and only the answers in the packet. *matchQuestion = q; return (oldstate == LLQ_SecondaryRequest ? uDNS_LLQ_Entire : uDNS_LLQ_Ignore); } } } } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } *matchQuestion = mDNSNULL; return uDNS_LLQ_Not; } // Stub definition of TCPSocket_struct so we can access flags field. (Rest of TCPSocket_struct is platform-dependent.) struct TCPSocket_struct { mDNSIPPort port; TCPSocketFlags flags; /* ... */ }; // tcpCallback is called to handle events (e.g. connection opening and data reception) on TCP connections for // Private DNS operations -- private queries, private LLQs, private record updates and private service updates mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEstablished, mStatus err) { tcpInfo_t *tcpInfo = (tcpInfo_t *)context; mDNSBool closed = mDNSfalse; mDNS *m = tcpInfo->m; DNSQuestion *const q = tcpInfo->question; tcpInfo_t **backpointer = q ? &q->tcp : tcpInfo->rr ? &tcpInfo->rr->tcp : mDNSNULL; if (backpointer && *backpointer != tcpInfo) LogMsg("tcpCallback: %d backpointer %p incorrect tcpInfo %p question %p rr %p", mDNSPlatformTCPGetFD(tcpInfo->sock), *backpointer, tcpInfo, q, tcpInfo->rr); if (err) goto exit; if (ConnectionEstablished) { mDNSu8 *end = ((mDNSu8*) &tcpInfo->request) + tcpInfo->requestLen; DomainAuthInfo *AuthInfo; // Defensive coding for Crash in mDNSResponder at GetAuthInfoForName_internal + 366 // Don't know yet what's causing this, but at least we can be cautious and try to avoid crashing if we find our pointers in an unexpected state if (tcpInfo->rr && tcpInfo->rr->resrec.name != &tcpInfo->rr->namestorage) LogMsg("tcpCallback: ERROR: tcpInfo->rr->resrec.name %p != &tcpInfo->rr->namestorage %p", tcpInfo->rr->resrec.name, &tcpInfo->rr->namestorage); if (tcpInfo->rr && tcpInfo->rr->resrec.name != &tcpInfo->rr->namestorage) return; AuthInfo = tcpInfo->rr ? GetAuthInfoForName(m, tcpInfo->rr->resrec.name) : mDNSNULL; // connection is established - send the message if (q && q->LongLived && q->state == LLQ_Established) { // Lease renewal over TCP, resulting from opening a TCP connection in sendLLQRefresh end = ((mDNSu8*) &tcpInfo->request) + tcpInfo->requestLen; } else if (q && q->LongLived && q->state != LLQ_Poll && !mDNSIPPortIsZero(m->LLQNAT.ExternalPort) && !mDNSIPPortIsZero(q->servPort)) { // Notes: // If we have a NAT port mapping, ExternalPort is the external port // If we have a routable address so we don't need a port mapping, ExternalPort is the same as our own internal port // If we need a NAT port mapping but can't get one, then ExternalPort is zero LLQOptData llqData; // set llq rdata llqData.vers = kLLQ_Vers; llqData.llqOp = kLLQOp_Setup; llqData.err = GetLLQEventPort(m, &tcpInfo->Addr); // We're using TCP; tell server what UDP port to send notifications to LogInfo("tcpCallback: eventPort %d", llqData.err); llqData.id = zeroOpaque64; llqData.llqlease = kLLQ_DefLease; InitializeDNSMessage(&tcpInfo->request.h, q->TargetQID, uQueryFlags); end = putLLQ(&tcpInfo->request, tcpInfo->request.data, q, &llqData); if (!end) { LogMsg("ERROR: tcpCallback - putLLQ"); err = mStatus_UnknownErr; goto exit; } AuthInfo = q->AuthInfo; // Need to add TSIG to this message q->ntries = 0; // Reset ntries so that tcp/tls connection failures don't affect sendChallengeResponse failures } else if (q) { mDNSOpaque16 HeaderFlags = uQueryFlags; // LLQ Polling mode or non-LLQ uDNS over TCP InitializeDNSMessage(&tcpInfo->request.h, q->TargetQID, HeaderFlags); end = putQuestion(&tcpInfo->request, tcpInfo->request.data, tcpInfo->request.data + AbsoluteMaxDNSMessageData, &q->qname, q->qtype, q->qclass); AuthInfo = q->AuthInfo; // Need to add TSIG to this message } err = mDNSSendDNSMessage(m, &tcpInfo->request, end, mDNSInterface_Any, sock, mDNSNULL, &tcpInfo->Addr, tcpInfo->Port, AuthInfo, mDNSfalse); if (err) { debugf("ERROR: tcpCallback: mDNSSendDNSMessage - %d", err); err = mStatus_UnknownErr; goto exit; } #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if (mDNSSameIPPort(tcpInfo->Port, UnicastDNSPort)) { MetricsUpdateDNSQuerySize((mDNSu32)(end - (mDNSu8 *)&tcpInfo->request)); } #endif // Record time we sent this question if (q) { mDNS_Lock(m); q->LastQTime = m->timenow; if (q->ThisQInterval < (256 * mDNSPlatformOneSecond)) // Now we have a TCP connection open, make sure we wait at least 256 seconds before retrying q->ThisQInterval = (256 * mDNSPlatformOneSecond); SetNextQueryTime(m, q); mDNS_Unlock(m); } } else { long n; const mDNSBool Read_replylen = (tcpInfo->nread < 2); // Do we need to read the replylen field first? if (Read_replylen) // First read the two-byte length preceeding the DNS message { mDNSu8 *lenptr = (mDNSu8 *)&tcpInfo->replylen; n = mDNSPlatformReadTCP(sock, lenptr + tcpInfo->nread, 2 - tcpInfo->nread, &closed); if (n < 0) { LogMsg("ERROR: tcpCallback - attempt to read message length failed (%d)", n); err = mStatus_ConnFailed; goto exit; } else if (closed) { // It's perfectly fine for this socket to close after the first reply. The server might // be sending gratuitous replies using UDP and doesn't have a need to leave the TCP socket open. // We'll only log this event if we've never received a reply before. // BIND 9 appears to close an idle connection after 30 seconds. if (tcpInfo->numReplies == 0) { LogMsg("ERROR: socket closed prematurely tcpInfo->nread = %d", tcpInfo->nread); err = mStatus_ConnFailed; goto exit; } else { // Note that we may not be doing the best thing if an error occurs after we've sent a second request // over this tcp connection. That is, we only track whether we've received at least one response // which may have been to a previous request sent over this tcp connection. if (backpointer) *backpointer = mDNSNULL; // Clear client backpointer FIRST so we don't risk double-disposing our tcpInfo_t DisposeTCPConn(tcpInfo); return; } } tcpInfo->nread += n; if (tcpInfo->nread < 2) goto exit; tcpInfo->replylen = (mDNSu16)((mDNSu16)lenptr[0] << 8 | lenptr[1]); if (tcpInfo->replylen < sizeof(DNSMessageHeader)) { LogMsg("ERROR: tcpCallback - length too short (%d bytes)", tcpInfo->replylen); err = mStatus_UnknownErr; goto exit; } tcpInfo->reply = (DNSMessage *) mDNSPlatformMemAllocate(tcpInfo->replylen); if (!tcpInfo->reply) { LogMsg("ERROR: tcpCallback - malloc failed"); err = mStatus_NoMemoryErr; goto exit; } } n = mDNSPlatformReadTCP(sock, ((char *)tcpInfo->reply) + (tcpInfo->nread - 2), tcpInfo->replylen - (tcpInfo->nread - 2), &closed); if (n < 0) { // If this is our only read for this invokation, and it fails, then that's bad. // But if we did successfully read some or all of the replylen field this time through, // and this is now our second read from the socket, then it's expected that sometimes // there may be no more data present, and that's perfectly okay. // Assuming failure of the second read is a problem is what caused this bug: // mDNSResponder fails to read DNS over TCP packet correctly if (!Read_replylen) { LogMsg("ERROR: tcpCallback - read returned %d", n); err = mStatus_ConnFailed; } goto exit; } else if (closed) { if (tcpInfo->numReplies == 0) { LogMsg("ERROR: socket closed prematurely tcpInfo->nread = %d", tcpInfo->nread); err = mStatus_ConnFailed; goto exit; } else { // Note that we may not be doing the best thing if an error occurs after we've sent a second request // over this tcp connection. That is, we only track whether we've received at least one response // which may have been to a previous request sent over this tcp connection. if (backpointer) *backpointer = mDNSNULL; // Clear client backpointer FIRST so we don't risk double-disposing our tcpInfo_t DisposeTCPConn(tcpInfo); return; } } tcpInfo->nread += n; if ((tcpInfo->nread - 2) == tcpInfo->replylen) { mDNSBool tls; DNSMessage *reply = tcpInfo->reply; mDNSu8 *end = (mDNSu8 *)tcpInfo->reply + tcpInfo->replylen; mDNSAddr Addr = tcpInfo->Addr; mDNSIPPort Port = tcpInfo->Port; mDNSIPPort srcPort = zeroIPPort; tcpInfo->numReplies++; tcpInfo->reply = mDNSNULL; // Detach reply buffer from tcpInfo_t, to make sure client callback can't cause it to be disposed tcpInfo->nread = 0; tcpInfo->replylen = 0; // If we're going to dispose this connection, do it FIRST, before calling client callback // Note: Sleep code depends on us clearing *backpointer here -- it uses the clearing of rr->tcp // as the signal that the DNS deregistration operation with the server has completed, and the machine may now sleep // If we clear the tcp pointer in the question, mDNSCoreReceiveResponse cannot find a matching question. Hence // we store the minimal information i.e., the source port of the connection in the question itself. // Dereference sock before it is disposed in DisposeTCPConn below. if (sock->flags & kTCPSocketFlags_UseTLS) tls = mDNStrue; else tls = mDNSfalse; if (q && q->tcp) {srcPort = q->tcp->SrcPort; q->tcpSrcPort = srcPort;} if (backpointer) if (!q || !q->LongLived || m->SleepState) { *backpointer = mDNSNULL; DisposeTCPConn(tcpInfo); } mDNSCoreReceive(m, reply, end, &Addr, Port, tls ? (mDNSAddr *)1 : mDNSNULL, srcPort, 0); // USE CAUTION HERE: Invoking mDNSCoreReceive may have caused the environment to change, including canceling this operation itself mDNSPlatformMemFree(reply); return; } } exit: if (err) { // Clear client backpointer FIRST -- that way if one of the callbacks cancels its operation // we won't end up double-disposing our tcpInfo_t if (backpointer) *backpointer = mDNSNULL; mDNS_Lock(m); // Need to grab the lock to get m->timenow if (q) { if (q->ThisQInterval == 0) { // We get here when we fail to establish a new TCP/TLS connection that would have been used for a new LLQ request or an LLQ renewal. // Note that ThisQInterval is also zero when sendChallengeResponse resends the LLQ request on an extant TCP/TLS connection. q->LastQTime = m->timenow; if (q->LongLived) { // We didn't get the chance to send our request packet before the TCP/TLS connection failed. // We want to retry quickly, but want to back off exponentially in case the server is having issues. // Since ThisQInterval was 0, we can't just multiply by QuestionIntervalStep, we must track the number // of TCP/TLS connection failures using ntries. mDNSu32 count = q->ntries + 1; // want to wait at least 1 second before retrying q->ThisQInterval = InitialQuestionInterval; for (; count; count--) q->ThisQInterval *= QuestionIntervalStep; if (q->ThisQInterval > LLQ_POLL_INTERVAL) q->ThisQInterval = LLQ_POLL_INTERVAL; else q->ntries++; LogMsg("tcpCallback: stream connection for LLQ %##s (%s) failed %d times, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ntries, q->ThisQInterval); } else { q->ThisQInterval = MAX_UCAST_POLL_INTERVAL; LogMsg("tcpCallback: stream connection for %##s (%s) failed, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); } SetNextQueryTime(m, q); } else if (NextQSendTime(q) - m->timenow > (q->LongLived ? LLQ_POLL_INTERVAL : MAX_UCAST_POLL_INTERVAL)) { // If we get an error and our next scheduled query for this question is more than the max interval from now, // reset the next query to ensure we wait no longer the maximum interval from now before trying again. q->LastQTime = m->timenow; q->ThisQInterval = q->LongLived ? LLQ_POLL_INTERVAL : MAX_UCAST_POLL_INTERVAL; SetNextQueryTime(m, q); LogMsg("tcpCallback: stream connection for %##s (%s) failed, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); } // We're about to dispose of the TCP connection, so we must reset the state to retry over TCP/TLS // because sendChallengeResponse will send the query via UDP if we don't have a tcp pointer. // Resetting to LLQ_InitialRequest will cause uDNS_CheckCurrentQuestion to call startLLQHandshake, which // will attempt to establish a new tcp connection. if (q->LongLived && q->state == LLQ_SecondaryRequest) q->state = LLQ_InitialRequest; // ConnFailed may happen if the server sends a TCP reset or TLS fails, in which case we want to retry establishing the LLQ // quickly rather than switching to polling mode. This case is handled by the above code to set q->ThisQInterval just above. // If the error isn't ConnFailed, then the LLQ is in bad shape, so we switch to polling mode. if (err != mStatus_ConnFailed) { if (q->LongLived && q->state != LLQ_Poll) StartLLQPolling(m, q); } } mDNS_Unlock(m); DisposeTCPConn(tcpInfo); } } mDNSlocal tcpInfo_t *MakeTCPConn(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, TCPSocketFlags flags, const mDNSAddr *const Addr, const mDNSIPPort Port, domainname *hostname, DNSQuestion *const question, AuthRecord *const rr) { mStatus err; mDNSIPPort srcport = zeroIPPort; tcpInfo_t *info; mDNSBool useBackgroundTrafficClass; useBackgroundTrafficClass = question ? question->UseBackgroundTraffic : mDNSfalse; if ((flags & kTCPSocketFlags_UseTLS) && (!hostname || !hostname->c[0])) { LogMsg("MakeTCPConn: TLS connection being setup with NULL hostname"); return mDNSNULL; } info = (tcpInfo_t *) mDNSPlatformMemAllocateClear(sizeof(*info)); if (!info) { LogMsg("ERROR: MakeTCP - memallocate failed"); return(mDNSNULL); } if (msg) { const mDNSu8 *const start = (const mDNSu8 *)msg; if ((end < start) || ((end - start) > (int)sizeof(info->request))) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "MakeTCPConn: invalid DNS message pointers -- msg: %p, end: %p", msg, end); mDNSPlatformMemFree(info); return mDNSNULL; } info->requestLen = (int)(end - start); mDNSPlatformMemCopy(&info->request, msg, info->requestLen); } info->m = m; info->sock = mDNSPlatformTCPSocket(flags, Addr->type, &srcport, hostname, useBackgroundTrafficClass); info->question = question; info->rr = rr; info->Addr = *Addr; info->Port = Port; info->reply = mDNSNULL; info->replylen = 0; info->nread = 0; info->numReplies = 0; info->SrcPort = srcport; if (!info->sock) { LogMsg("MakeTCPConn: unable to create TCP socket"); mDNSPlatformMemFree(info); return(mDNSNULL); } mDNSPlatformSetSocktOpt(info->sock, mDNSTransport_TCP, Addr->type, question); err = mDNSPlatformTCPConnect(info->sock, Addr, Port, (question ? question->InterfaceID : mDNSNULL), tcpCallback, info); // Probably suboptimal here. // Instead of returning mDNSNULL here on failure, we should probably invoke the callback with an error code. // That way clients can put all the error handling and retry/recovery code in one place, // instead of having to handle immediate errors in one place and async errors in another. // Also: "err == mStatus_ConnEstablished" probably never happens. // Don't need to log "connection failed" in customer builds -- it happens quite often during sleep, wake, configuration changes, etc. if (err == mStatus_ConnEstablished) { tcpCallback(info->sock, info, mDNStrue, mStatus_NoError); } else if (err != mStatus_ConnPending ) { LogInfo("MakeTCPConn: connection failed"); DisposeTCPConn(info); return(mDNSNULL); } return(info); } mDNSexport void DisposeTCPConn(struct tcpInfo_t *tcp) { mDNSPlatformTCPCloseConnection(tcp->sock); if (tcp->reply) mDNSPlatformMemFree(tcp->reply); mDNSPlatformMemFree(tcp); } // Lock must be held mDNSexport void startLLQHandshake(mDNS *m, DNSQuestion *q) { // States prior to LLQ_InitialRequest should not react to NAT Mapping changes. // startLLQHandshake is never called with q->state < LLQ_InitialRequest except // from LLQNATCallback. When we are actually trying to do LLQ, then q->state will // be equal to or greater than LLQ_InitialRequest when LLQNATCallback calls // startLLQHandshake. if (q->state < LLQ_InitialRequest) { return; } if (m->LLQNAT.clientContext != mDNSNULL) // LLQNAT just started, give it some time { LogInfo("startLLQHandshake: waiting for NAT status for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes q->LastQTime = m->timenow; SetNextQueryTime(m, q); return; } // Either we don't have {PCP, NAT-PMP, UPnP/IGD} support (ExternalPort is zero) or behind a Double NAT that may or // may not have {PCP, NAT-PMP, UPnP/IGD} support (NATResult is non-zero) if (mDNSIPPortIsZero(m->LLQNAT.ExternalPort) || m->LLQNAT.Result) { LogInfo("startLLQHandshake: Cannot receive inbound packets; will poll for %##s (%s) External Port %d, NAT Result %d", q->qname.c, DNSTypeName(q->qtype), mDNSVal16(m->LLQNAT.ExternalPort), m->LLQNAT.Result); StartLLQPolling(m, q); return; } if (mDNSIPPortIsZero(q->servPort)) { debugf("startLLQHandshake: StartGetZoneData for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes q->LastQTime = m->timenow; SetNextQueryTime(m, q); q->servAddr = zeroAddr; // We know q->servPort is zero because of check above if (q->nta) CancelGetZoneData(m, q->nta); q->nta = StartGetZoneData(m, &q->qname, ZoneServiceLLQ, LLQGotZoneData, q); return; } debugf("startLLQHandshake: m->AdvertisedV4 %#a%s Server %#a:%d%s %##s (%s)", &m->AdvertisedV4, mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) ? " (RFC 1918)" : "", &q->servAddr, mDNSVal16(q->servPort), mDNSAddrIsRFC1918(&q->servAddr) ? " (RFC 1918)" : "", q->qname.c, DNSTypeName(q->qtype)); if (q->ntries++ >= kLLQ_MAX_TRIES) { LogMsg("startLLQHandshake: %d failed attempts for LLQ %##s Polling.", kLLQ_MAX_TRIES, q->qname.c); StartLLQPolling(m, q); } else { mDNSu8 *end; LLQOptData llqData; // set llq rdata llqData.vers = kLLQ_Vers; llqData.llqOp = kLLQOp_Setup; llqData.err = LLQErr_NoError; // Don't need to tell server UDP notification port when sending over UDP llqData.id = zeroOpaque64; llqData.llqlease = kLLQ_DefLease; InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); end = putLLQ(&m->omsg, m->omsg.data, q, &llqData); if (!end) { LogMsg("ERROR: startLLQHandshake - putLLQ"); StartLLQPolling(m,q); return; } mDNSSendDNSMessage(m, &m->omsg, end, mDNSInterface_Any, mDNSNULL, q->LocalSocket, &q->servAddr, q->servPort , mDNSNULL, mDNSfalse); // update question state q->state = LLQ_InitialRequest; q->ReqLease = kLLQ_DefLease; q->ThisQInterval = (kLLQ_INIT_RESEND * mDNSPlatformOneSecond); q->LastQTime = m->timenow; SetNextQueryTime(m, q); } } // forward declaration so GetServiceTarget can do reverse lookup if needed mDNSlocal void GetStaticHostname(mDNS *m); mDNSexport const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr) { debugf("GetServiceTarget %##s", rr->resrec.name->c); if (!rr->AutoTarget) // If not automatically tracking this host's current name, just return the existing target return(&rr->resrec.rdata->u.srv.target); else { { const int srvcount = CountLabels(rr->resrec.name); HostnameInfo *besthi = mDNSNULL, *hi; int best = 0; for (hi = m->Hostnames; hi; hi = hi->next) if (hi->arv4.state == regState_Registered || hi->arv4.state == regState_Refresh || hi->arv6.state == regState_Registered || hi->arv6.state == regState_Refresh) { int x, hostcount = CountLabels(&hi->fqdn); for (x = hostcount < srvcount ? hostcount : srvcount; x > 0 && x > best; x--) if (SameDomainName(SkipLeadingLabels(rr->resrec.name, srvcount - x), SkipLeadingLabels(&hi->fqdn, hostcount - x))) { best = x; besthi = hi; } } if (besthi) return(&besthi->fqdn); } if (m->StaticHostname.c[0]) return(&m->StaticHostname); else GetStaticHostname(m); // asynchronously do reverse lookup for primary IPv4 address LogInfo("GetServiceTarget: Returning NULL for %s", ARDisplayString(m, rr)); return(mDNSNULL); } } mDNSlocal const domainname *PUBLIC_UPDATE_SERVICE_TYPE = (const domainname*)"\x0B_dns-update" "\x04_udp"; mDNSlocal const domainname *PUBLIC_LLQ_SERVICE_TYPE = (const domainname*)"\x08_dns-llq" "\x04_udp"; mDNSlocal const domainname *PRIVATE_UPDATE_SERVICE_TYPE = (const domainname*)"\x0F_dns-update-tls" "\x04_tcp"; mDNSlocal const domainname *PRIVATE_QUERY_SERVICE_TYPE = (const domainname*)"\x0E_dns-query-tls" "\x04_tcp"; mDNSlocal const domainname *PRIVATE_LLQ_SERVICE_TYPE = (const domainname*)"\x0C_dns-llq-tls" "\x04_tcp"; mDNSlocal const domainname *DNS_PUSH_NOTIFICATION_SERVICE_TYPE = (const domainname*)"\x0D_dns-push-tls" "\x04_tcp"; #define ZoneDataSRV(X) ( \ (X)->ZoneService == ZoneServiceUpdate ? ((X)->ZonePrivate ? PRIVATE_UPDATE_SERVICE_TYPE : PUBLIC_UPDATE_SERVICE_TYPE) : \ (X)->ZoneService == ZoneServiceQuery ? ((X)->ZonePrivate ? PRIVATE_QUERY_SERVICE_TYPE : (const domainname*)"" ) : \ (X)->ZoneService == ZoneServiceLLQ ? ((X)->ZonePrivate ? PRIVATE_LLQ_SERVICE_TYPE : PUBLIC_LLQ_SERVICE_TYPE ) : \ (X)->ZoneService == ZoneServiceDNSPush ? DNS_PUSH_NOTIFICATION_SERVICE_TYPE : (const domainname*)"") // Forward reference: GetZoneData_StartQuery references GetZoneData_QuestionCallback, and // GetZoneData_QuestionCallback calls GetZoneData_StartQuery mDNSlocal mStatus GetZoneData_StartQuery(mDNS *const m, ZoneData *zd, mDNSu16 qtype); // GetZoneData_QuestionCallback is called from normal client callback context (core API calls allowed) mDNSlocal void GetZoneData_QuestionCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) { ZoneData *zd = (ZoneData*)question->QuestionContext; debugf("GetZoneData_QuestionCallback: %s %s", AddRecord ? "Add" : "Rmv", RRDisplayString(m, answer)); if (!AddRecord) return; // Don't care about REMOVE events if (AddRecord == QC_addnocache && answer->rdlength == 0) return; // Don't care about transient failure indications if (answer->rrtype != question->qtype) return; // Don't care about CNAMEs if (answer->rrtype == kDNSType_SOA) { debugf("GetZoneData GOT SOA %s", RRDisplayString(m, answer)); mDNS_StopQuery(m, question); if (question->ThisQInterval != -1) LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); if (answer->rdlength) { AssignDomainName(&zd->ZoneName, answer->name); zd->ZoneClass = answer->rrclass; GetZoneData_StartQuery(m, zd, kDNSType_SRV); } else if (zd->CurrentSOA->c[0]) { zd->CurrentSOA = (domainname *)(zd->CurrentSOA->c + zd->CurrentSOA->c[0]+1); AssignDomainName(&zd->question.qname, zd->CurrentSOA); GetZoneData_StartQuery(m, zd, kDNSType_SOA); } else { LogInfo("GetZoneData recursed to root label of %##s without finding SOA", zd->ChildName.c); zd->ZoneDataCallback(m, mStatus_NoSuchNameErr, zd); } } else if (answer->rrtype == kDNSType_SRV) { debugf("GetZoneData GOT SRV %s", RRDisplayString(m, answer)); mDNS_StopQuery(m, question); if (question->ThisQInterval != -1) LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); // Right now we don't want to fail back to non-encrypted operations // If the AuthInfo has the AutoTunnel field set, then we want private or nothing // BTMM: Don't fallback to unencrypted operations when SRV lookup fails #if 0 if (!answer->rdlength && zd->ZonePrivate && zd->ZoneService != ZoneServiceQuery) { zd->ZonePrivate = mDNSfalse; // Causes ZoneDataSRV() to yield a different SRV name when building the query GetZoneData_StartQuery(m, zd, kDNSType_SRV); // Try again, non-private this time } else #endif { if (answer->rdlength) { AssignDomainName(&zd->Host, &answer->rdata->u.srv.target); zd->Port = answer->rdata->u.srv.port; // The MakeTCPConn path, which is used by everything but DNS Push, won't work at all for // IPv6. This should be fixed for all cases we care about, but for now we make an exception // for Push notifications: we do not look up the a record here, but rather rely on the DSO // infrastructure to do a GetAddrInfo call on the name and try each IP address in sequence // until one connects. We can't do this for the other use cases because this is in the DSO // code, not in MakeTCPConn. Ultimately the fix for this is to use Network Framework to do // the connection establishment for all of these use cases. // // One implication of this is that if two different zones have DNS push server SRV records // pointing to the same server using a different domain name, we will not see these as being // the same server, and will not share the connection. This isn't something we can easily // fix, and so the advice if someone runs into this and considers it a problem should be to // use the same name. // // Another issue with this code is that at present, we do not wait for more than one SRV // record--we cancel the query as soon as the first one comes in. This isn't ideal: it // would be better to wait until we've gotten all our answers and then pick the one with // the highest priority. Of course, this is unlikely to cause an operational problem in // practice, and as with the previous point, the fix is easy: figure out which server you // want people to use and don't list any other servers. Fully switching to Network // Framework for this would (I think!) address this problem, or at least make it someone // else's problem. if (zd->ZoneService != ZoneServiceDNSPush) { AssignDomainName(&zd->question.qname, &zd->Host); GetZoneData_StartQuery(m, zd, kDNSType_A); } else { zd->ZoneDataCallback(m, mStatus_NoError, zd); } } else { zd->ZonePrivate = mDNSfalse; zd->Host.c[0] = 0; zd->Port = zeroIPPort; zd->Addr = zeroAddr; zd->ZoneDataCallback(m, mStatus_NoError, zd); } } } else if (answer->rrtype == kDNSType_A) { debugf("GetZoneData GOT A %s", RRDisplayString(m, answer)); mDNS_StopQuery(m, question); if (question->ThisQInterval != -1) LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); zd->Addr.type = mDNSAddrType_IPv4; if (answer->rdlength == 4) zd->Addr.ip.v4 = answer->rdata->u.ipv4; else zd->Addr.ip.v4 = zerov4Addr; // In order to simulate firewalls blocking our outgoing TCP connections, returning immediate ICMP errors or TCP resets, // the code below will make us try to connect to loopback, resulting in an immediate "port unreachable" failure. // This helps us test to make sure we handle this case gracefully // BTMM: mDNSResponder taking 100 percent CPU after upgrading to 10.5.1 #if 0 zd->Addr.ip.v4.b[0] = 127; zd->Addr.ip.v4.b[1] = 0; zd->Addr.ip.v4.b[2] = 0; zd->Addr.ip.v4.b[3] = 1; #endif // The caller needs to free the memory when done with zone data zd->ZoneDataCallback(m, mStatus_NoError, zd); } } // GetZoneData_StartQuery is called from normal client context (lock not held, or client callback) mDNSlocal mStatus GetZoneData_StartQuery(mDNS *const m, ZoneData *zd, mDNSu16 qtype) { if (qtype == kDNSType_SRV) { AssignDomainName(&zd->question.qname, ZoneDataSRV(zd)); AppendDomainName(&zd->question.qname, &zd->ZoneName); debugf("lookupDNSPort %##s", zd->question.qname.c); } // CancelGetZoneData can get called at any time. We should stop the question if it has not been // stopped already. A value of -1 for ThisQInterval indicates that the question is not active // yet. zd->question.ThisQInterval = -1; zd->question.InterfaceID = mDNSInterface_Any; zd->question.flags = 0; //zd->question.qname.c[0] = 0; // Already set zd->question.qtype = qtype; zd->question.qclass = kDNSClass_IN; zd->question.LongLived = mDNSfalse; zd->question.ExpectUnique = mDNStrue; zd->question.ForceMCast = mDNSfalse; zd->question.ReturnIntermed = mDNStrue; zd->question.SuppressUnusable = mDNSfalse; zd->question.AppendSearchDomains = 0; zd->question.TimeoutQuestion = 0; zd->question.WakeOnResolve = 0; zd->question.UseBackgroundTraffic = mDNSfalse; zd->question.ProxyQuestion = 0; zd->question.pid = mDNSPlatformGetPID(); zd->question.euid = 0; zd->question.QuestionCallback = GetZoneData_QuestionCallback; zd->question.QuestionContext = zd; //LogMsg("GetZoneData_StartQuery %##s (%s) %p", zd->question.qname.c, DNSTypeName(zd->question.qtype), zd->question.Private); return(mDNS_StartQuery(m, &zd->question)); } // StartGetZoneData is an internal routine (i.e. must be called with the lock already held) mDNSexport ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *ZoneDataContext) { ZoneData *zd = (ZoneData*) mDNSPlatformMemAllocateClear(sizeof(*zd)); if (!zd) { LogMsg("ERROR: StartGetZoneData - mDNSPlatformMemAllocateClear failed"); return mDNSNULL; } AssignDomainName(&zd->ChildName, name); zd->ZoneService = target; zd->CurrentSOA = &zd->ChildName; zd->ZoneName.c[0] = 0; zd->ZoneClass = 0; zd->Host.c[0] = 0; zd->Port = zeroIPPort; zd->Addr = zeroAddr; zd->ZonePrivate = mDNSfalse; zd->ZoneDataCallback = callback; zd->ZoneDataContext = ZoneDataContext; zd->question.QuestionContext = zd; mDNS_DropLockBeforeCallback(); // GetZoneData_StartQuery expects to be called from a normal callback, so we emulate that here AssignDomainName(&zd->question.qname, zd->CurrentSOA); GetZoneData_StartQuery(m, zd, kDNSType_SOA); mDNS_ReclaimLockAfterCallback(); return zd; } // Returns if the question is a GetZoneData question. These questions are special in // that they are created internally while resolving a private query or LLQs. mDNSexport mDNSBool IsGetZoneDataQuestion(DNSQuestion *q) { if (q->QuestionCallback == GetZoneData_QuestionCallback) return(mDNStrue); else return(mDNSfalse); } // GetZoneData queries are a special case -- even if we have a key for them, we don't do them privately, // because that would result in an infinite loop (i.e. to do a private query we first need to get // the _dns-query-tls SRV record for the zone, and we can't do *that* privately because to do so // we'd need to already know the _dns-query-tls SRV record. // Also, as a general rule, we never do SOA queries privately mDNSexport DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q) // Must be called with lock held { if (q->QuestionCallback == GetZoneData_QuestionCallback) return(mDNSNULL); if (q->qtype == kDNSType_SOA ) return(mDNSNULL); return(GetAuthInfoForName_internal(m, &q->qname)); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - host name and interface management #endif mDNSlocal void SendRecordRegistration(mDNS *const m, AuthRecord *rr); mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr); mDNSlocal mDNSBool IsRecordMergeable(mDNS *const m, AuthRecord *rr, mDNSs32 time); // When this function is called, service record is already deregistered. We just // have to deregister the PTR and TXT records. mDNSlocal void UpdateAllServiceRecords(mDNS *const m, AuthRecord *rr, mDNSBool reg) { AuthRecord *r, *srvRR; if (rr->resrec.rrtype != kDNSType_SRV) { LogMsg("UpdateAllServiceRecords:ERROR!! ResourceRecord not a service record %s", ARDisplayString(m, rr)); return; } if (reg && rr->state == regState_NoTarget) { LogMsg("UpdateAllServiceRecords:ERROR!! SRV record %s in noTarget state during registration", ARDisplayString(m, rr)); return; } LogInfo("UpdateAllServiceRecords: ResourceRecord %s", ARDisplayString(m, rr)); for (r = m->ResourceRecords; r; r=r->next) { if (!AuthRecord_uDNS(r)) continue; srvRR = mDNSNULL; if (r->resrec.rrtype == kDNSType_PTR) srvRR = r->Additional1; else if (r->resrec.rrtype == kDNSType_TXT) srvRR = r->DependentOn; if (srvRR && srvRR->resrec.rrtype != kDNSType_SRV) LogMsg("UpdateAllServiceRecords: ERROR!! Resource record %s wrong, expecting SRV type", ARDisplayString(m, srvRR)); if (srvRR == rr) { if (!reg) { LogInfo("UpdateAllServiceRecords: deregistering %s", ARDisplayString(m, r)); r->SRVChanged = mDNStrue; r->ThisAPInterval = INIT_RECORD_REG_INTERVAL; r->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; r->state = regState_DeregPending; } else { // Clearing SRVchanged is a safety measure. If our pevious dereg never // came back and we had a target change, we are starting fresh r->SRVChanged = mDNSfalse; // if it is already registered or in the process of registering, then don't // bother re-registering. This happens today for non-BTMM domains where the // TXT and PTR get registered before SRV records because of the delay in // getting the port mapping. There is no point in re-registering the TXT // and PTR records. if ((r->state == regState_Registered) || (r->state == regState_Pending && r->nta && !mDNSIPv4AddressIsZero(r->nta->Addr.ip.v4))) LogInfo("UpdateAllServiceRecords: not registering %s, state %d", ARDisplayString(m, r), r->state); else { LogInfo("UpdateAllServiceRecords: registering %s, state %d", ARDisplayString(m, r), r->state); ActivateUnicastRegistration(m, r); } } } } } // Called in normal client context (lock not held) // Currently only supports SRV records for nat mapping mDNSlocal void CompleteRecordNatMap(mDNS *m, NATTraversalInfo *n) { const domainname *target; domainname *srvt; AuthRecord *rr = (AuthRecord *)n->clientContext; debugf("SRVNatMap complete %.4a IntPort %u ExternalPort %u NATLease %u", &n->ExternalAddress, mDNSVal16(n->IntPort), mDNSVal16(n->ExternalPort), n->NATLease); if (!rr) { LogMsg("CompleteRecordNatMap called with unknown AuthRecord object"); return; } if (!n->NATLease) { LogMsg("CompleteRecordNatMap No NATLease for %s", ARDisplayString(m, rr)); return; } if (rr->resrec.rrtype != kDNSType_SRV) {LogMsg("CompleteRecordNatMap: Not a service record %s", ARDisplayString(m, rr)); return; } if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) { LogInfo("CompleteRecordNatMap called for %s, Service deregistering", ARDisplayString(m, rr)); return; } if (rr->state == regState_DeregPending) { LogInfo("CompleteRecordNatMap called for %s, record in DeregPending", ARDisplayString(m, rr)); return; } // As we free the zone info after registering/deregistering with the server (See hndlRecordUpdateReply), // we need to restart the get zone data and nat mapping request to get the latest mapping result as we can't handle it // at this moment. Restart from the beginning. if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) { LogInfo("CompleteRecordNatMap called for %s but no zone information!", ARDisplayString(m, rr)); // We need to clear out the NATinfo state so that it will result in re-acquiring the mapping // and hence this callback called again. if (rr->NATinfo.clientContext) { mDNS_StopNATOperation_internal(m, &rr->NATinfo); rr->NATinfo.clientContext = mDNSNULL; } rr->state = regState_Pending; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; return; } mDNS_Lock(m); // Reevaluate the target always as Target could have changed while // we were getting the port mapping (See UpdateOneSRVRecord) target = GetServiceTarget(m, rr); srvt = GetRRDomainNameTarget(&rr->resrec); if (!target || target->c[0] == 0 || mDNSIPPortIsZero(n->ExternalPort)) { if (target && target->c[0]) LogInfo("CompleteRecordNatMap - Target %##s for ResourceRecord %##s, ExternalPort %d", target->c, rr->resrec.name->c, mDNSVal16(n->ExternalPort)); else LogInfo("CompleteRecordNatMap - no target for %##s, ExternalPort %d", rr->resrec.name->c, mDNSVal16(n->ExternalPort)); if (srvt) srvt->c[0] = 0; rr->state = regState_NoTarget; rr->resrec.rdlength = rr->resrec.rdestimate = 0; mDNS_Unlock(m); UpdateAllServiceRecords(m, rr, mDNSfalse); return; } LogInfo("CompleteRecordNatMap - Target %##s for ResourceRecord %##s, ExternalPort %d", target->c, rr->resrec.name->c, mDNSVal16(n->ExternalPort)); // This function might get called multiple times during a network transition event. Previosuly, we could // have put the SRV record in NoTarget state above and deregistered all the other records. When this // function gets called again with a non-zero ExternalPort, we need to set the target and register the // other records again. if (srvt && !SameDomainName(srvt, target)) { AssignDomainName(srvt, target); SetNewRData(&rr->resrec, mDNSNULL, 0); // Update rdlength, rdestimate, rdatahash } // SRVChanged is set when when the target of the SRV record changes (See UpdateOneSRVRecord). // As a result of the target change, we might register just that SRV Record if it was // previously registered and we have a new target OR deregister SRV (and the associated // PTR/TXT records) if we don't have a target anymore. When we get a response from the server, // SRVChanged state tells that we registered/deregistered because of a target change // and hence handle accordingly e.g., if we deregistered, put the records in NoTarget state OR // if we registered then put it in Registered state. // // Here, we are registering all the records again from the beginning. Treat this as first time // registration rather than a temporary target change. rr->SRVChanged = mDNSfalse; // We want IsRecordMergeable to check whether it is a record whose update can be // sent with others. We set the time before we call IsRecordMergeable, so that // it does not fail this record based on time. We are interested in other checks // at this time rr->state = regState_Pending; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; if (IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) // Delay the record registration by MERGE_DELAY_TIME so that we can merge them // into one update rr->LastAPTime += MERGE_DELAY_TIME; mDNS_Unlock(m); // We call this always even though it may not be necessary always e.g., normal registration // process where TXT and PTR gets registered followed by the SRV record after it gets // the port mapping. In that case, UpdateAllServiceRecords handles the optimization. The // update of TXT and PTR record is required if we entered noTargetState before as explained // above. UpdateAllServiceRecords(m, rr, mDNStrue); } mDNSlocal void StartRecordNatMap(mDNS *m, AuthRecord *rr) { const mDNSu8 *p; mDNSu8 protocol; if (rr->resrec.rrtype != kDNSType_SRV) { LogInfo("StartRecordNatMap: Resource Record %##s type %d, not supported", rr->resrec.name->c, rr->resrec.rrtype); return; } p = rr->resrec.name->c; //Assume ... // Skip the first two labels to get to the transport protocol if (p[0]) p += 1 + p[0]; if (p[0]) p += 1 + p[0]; if (SameDomainLabel(p, (mDNSu8 *)"\x4" "_tcp")) protocol = NATOp_MapTCP; else if (SameDomainLabel(p, (mDNSu8 *)"\x4" "_udp")) protocol = NATOp_MapUDP; else { LogMsg("StartRecordNatMap: could not determine transport protocol of service %##s", rr->resrec.name->c); return; } //LogMsg("StartRecordNatMap: clientContext %p IntPort %d srv.port %d %s", // rr->NATinfo.clientContext, mDNSVal16(rr->NATinfo.IntPort), mDNSVal16(rr->resrec.rdata->u.srv.port), ARDisplayString(m, rr)); if (rr->NATinfo.clientContext) mDNS_StopNATOperation_internal(m, &rr->NATinfo); rr->NATinfo.Protocol = protocol; // Shouldn't be trying to set IntPort here -- // BuildUpdateMessage overwrites srs->RR_SRV.resrec.rdata->u.srv.port with external (mapped) port number rr->NATinfo.IntPort = rr->resrec.rdata->u.srv.port; rr->NATinfo.RequestedPort = rr->resrec.rdata->u.srv.port; rr->NATinfo.NATLease = 0; // Request default lease rr->NATinfo.clientCallback = CompleteRecordNatMap; rr->NATinfo.clientContext = rr; mDNS_StartNATOperation_internal(m, &rr->NATinfo); } // Unlink an Auth Record from the m->ResourceRecords list. // When a resource record enters regState_NoTarget initially, mDNS_Register_internal // does not initialize completely e.g., it cannot check for duplicates etc. The resource // record is temporarily left in the ResourceRecords list so that we can initialize later // when the target is resolvable. Similarly, when host name changes, we enter regState_NoTarget // and we do the same. // This UnlinkResourceRecord routine is very worrying. It bypasses all the normal cleanup performed // by mDNS_Deregister_internal and just unceremoniously cuts the record from the active list. // This is why re-regsitering this record was producing syslog messages like this: // "Error! Tried to add a NAT traversal that's already in the active list" // Right now UnlinkResourceRecord is fortunately only called by RegisterAllServiceRecords, // which then immediately calls mDNS_Register_internal to re-register the record, which probably // masked more serious problems. Any other use of UnlinkResourceRecord is likely to lead to crashes. // For now we'll workaround that specific problem by explicitly calling mDNS_StopNATOperation_internal, // but long-term we should either stop cancelling the record registration and then re-registering it, // or if we really do need to do this for some reason it should be done via the usual // mDNS_Deregister_internal path instead of just cutting the record from the list. mDNSlocal mStatus UnlinkResourceRecord(mDNS *const m, AuthRecord *const rr) { AuthRecord **list = &m->ResourceRecords; while (*list && *list != rr) list = &(*list)->next; if (*list) { *list = rr->next; rr->next = mDNSNULL; // Temporary workaround to cancel any active NAT mapping operation if (rr->NATinfo.clientContext) { mDNS_StopNATOperation_internal(m, &rr->NATinfo); rr->NATinfo.clientContext = mDNSNULL; if (rr->resrec.rrtype == kDNSType_SRV) rr->resrec.rdata->u.srv.port = rr->NATinfo.IntPort; } return(mStatus_NoError); } LogMsg("UnlinkResourceRecord:ERROR!! - no such active record %##s", rr->resrec.name->c); return(mStatus_NoSuchRecord); } // We need to go through mDNS_Register again as we did not complete the // full initialization last time e.g., duplicate checks. // After we register, we will be in regState_GetZoneData. mDNSlocal void RegisterAllServiceRecords(mDNS *const m, AuthRecord *rr) { LogInfo("RegisterAllServiceRecords: Service Record %##s", rr->resrec.name->c); // First Register the service record, we do this differently from other records because // when it entered NoTarget state, it did not go through complete initialization rr->SRVChanged = mDNSfalse; UnlinkResourceRecord(m, rr); mDNS_Register_internal(m, rr); // Register the other records UpdateAllServiceRecords(m, rr, mDNStrue); } // Called with lock held mDNSlocal void UpdateOneSRVRecord(mDNS *m, AuthRecord *rr) { // Target change if: // We have a target and were previously waiting for one, or // We had a target and no longer do, or // The target has changed domainname *curtarget = &rr->resrec.rdata->u.srv.target; const domainname *const nt = GetServiceTarget(m, rr); const domainname *const newtarget = nt ? nt : (domainname*)""; mDNSBool TargetChanged = (newtarget->c[0] && rr->state == regState_NoTarget) || !SameDomainName(curtarget, newtarget); mDNSBool HaveZoneData = rr->nta && !mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4); // Nat state change if: // We were behind a NAT, and now we are behind a new NAT, or // We're not behind a NAT but our port was previously mapped to a different external port // We were not behind a NAT and now we are mDNSIPPort port = rr->resrec.rdata->u.srv.port; mDNSBool NowNeedNATMAP = (rr->AutoTarget == Target_AutoHostAndNATMAP && !mDNSIPPortIsZero(port) && mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) && rr->nta && !mDNSAddrIsRFC1918(&rr->nta->Addr)); mDNSBool WereBehindNAT = (rr->NATinfo.clientContext != mDNSNULL); mDNSBool PortWasMapped = (rr->NATinfo.clientContext && !mDNSSameIPPort(rr->NATinfo.RequestedPort, port)); // I think this is always false -- SC Sept 07 mDNSBool NATChanged = (!WereBehindNAT && NowNeedNATMAP) || (!NowNeedNATMAP && PortWasMapped); (void)HaveZoneData; //unused LogInfo("UpdateOneSRVRecord: Resource Record %s TargetChanged %d, NewTarget %##s", ARDisplayString(m, rr), TargetChanged, nt->c); debugf("UpdateOneSRVRecord: %##s newtarget %##s TargetChanged %d HaveZoneData %d port %d NowNeedNATMAP %d WereBehindNAT %d PortWasMapped %d NATChanged %d", rr->resrec.name->c, newtarget, TargetChanged, HaveZoneData, mDNSVal16(port), NowNeedNATMAP, WereBehindNAT, PortWasMapped, NATChanged); mDNS_CheckLock(m); if (!TargetChanged && !NATChanged) return; // If we are deregistering the record, then ignore any NAT/Target change. if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) { LogInfo("UpdateOneSRVRecord: Deregistering record, Ignoring TargetChanged %d, NATChanged %d for %##s, state %d", TargetChanged, NATChanged, rr->resrec.name->c, rr->state); return; } if (newtarget) LogInfo("UpdateOneSRVRecord: TargetChanged %d, NATChanged %d for %##s, state %d, newtarget %##s", TargetChanged, NATChanged, rr->resrec.name->c, rr->state, newtarget->c); else LogInfo("UpdateOneSRVRecord: TargetChanged %d, NATChanged %d for %##s, state %d, null newtarget", TargetChanged, NATChanged, rr->resrec.name->c, rr->state); switch(rr->state) { case regState_NATMap: // In these states, the SRV has either not yet been registered (it will get up-to-date information when it is) // or is in the process of, or has already been, deregistered. This assumes that whenever we transition out // of this state, we need to look at the target again. return; case regState_UpdatePending: // We are getting a Target change/NAT change while the SRV record is being updated ? // let us not do anything for now. return; case regState_NATError: if (!NATChanged) return; // if nat changed, register if we have a target (below) /* FALLTHROUGH */ case regState_NoTarget: if (!newtarget->c[0]) { LogInfo("UpdateOneSRVRecord: No target yet for Resource Record %s", ARDisplayString(m, rr)); return; } RegisterAllServiceRecords(m, rr); return; case regState_DeregPending: // We are in DeregPending either because the service was deregistered from above or we handled // a NAT/Target change before and sent the deregistration below. There are a few race conditions // possible // // 1. We are handling a second NAT/Target change while the first dereg is in progress. It is possible // that first dereg never made it through because there was no network connectivity e.g., disconnecting // from network triggers this function due to a target change and later connecting to the network // retriggers this function but the deregistration never made it through yet. Just fall through. // If there is a target register otherwise deregister. // // 2. While we sent the dereg during a previous NAT/Target change, uDNS_DeregisterRecord gets // called as part of service deregistration. When the response comes back, we call // CompleteDeregistration rather than handle NAT/Target change because the record is in // kDNSRecordTypeDeregistering state. // // 3. If the upper layer deregisters the service, we check for kDNSRecordTypeDeregistering both // here in this function to avoid handling NAT/Target change and in hndlRecordUpdateReply to call // CompleteDeregistration instead of handling NAT/Target change. Hence, we are not concerned // about that case here. // // We just handle case (1) by falling through case regState_Pending: case regState_Refresh: case regState_Registered: // target or nat changed. deregister service. upon completion, we'll look for a new target rr->SRVChanged = mDNStrue; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; if (newtarget->c[0]) { LogInfo("UpdateOneSRVRecord: SRV record changed for service %##s, registering with new target %##s", rr->resrec.name->c, newtarget->c); rr->state = regState_Pending; } else { LogInfo("UpdateOneSRVRecord: SRV record changed for service %##s de-registering", rr->resrec.name->c); rr->state = regState_DeregPending; UpdateAllServiceRecords(m, rr, mDNSfalse); } return; case regState_Unregistered: default: LogMsg("UpdateOneSRVRecord: Unknown state %d for %##s", rr->state, rr->resrec.name->c); } } mDNSexport void UpdateAllSRVRecords(mDNS *m) { m->NextSRVUpdate = 0; LogInfo("UpdateAllSRVRecords %d", m->SleepState); if (m->CurrentRecord) LogMsg("UpdateAllSRVRecords ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { AuthRecord *rptr = m->CurrentRecord; m->CurrentRecord = m->CurrentRecord->next; if (AuthRecord_uDNS(rptr) && rptr->resrec.rrtype == kDNSType_SRV) UpdateOneSRVRecord(m, rptr); } } // Forward reference: AdvertiseHostname references HostnameCallback, and HostnameCallback calls AdvertiseHostname mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result); // Called in normal client context (lock not held) mDNSlocal void hostnameGetPublicAddressCallback(mDNS *m, NATTraversalInfo *n) { HostnameInfo *h = (HostnameInfo *)n->clientContext; if (!h) { LogMsg("RegisterHostnameRecord: registration cancelled"); return; } if (!n->Result) { if (mDNSIPv4AddressIsZero(n->ExternalAddress) || mDNSv4AddrIsRFC1918(&n->ExternalAddress)) return; if (h->arv4.resrec.RecordType) { if (mDNSSameIPv4Address(h->arv4.resrec.rdata->u.ipv4, n->ExternalAddress)) return; // If address unchanged, do nothing LogInfo("Updating hostname %p %##s IPv4 from %.4a to %.4a (NAT gateway's external address)",n, h->arv4.resrec.name->c, &h->arv4.resrec.rdata->u.ipv4, &n->ExternalAddress); mDNS_Deregister(m, &h->arv4); // mStatus_MemFree callback will re-register with new address } else { LogInfo("Advertising hostname %##s IPv4 %.4a (NAT gateway's external address)", h->arv4.resrec.name->c, &n->ExternalAddress); h->arv4.resrec.RecordType = kDNSRecordTypeKnownUnique; h->arv4.resrec.rdata->u.ipv4 = n->ExternalAddress; mDNS_Register(m, &h->arv4); } } } // register record or begin NAT traversal mDNSlocal void AdvertiseHostname(mDNS *m, HostnameInfo *h) { if (!mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4) && h->arv4.resrec.RecordType == kDNSRecordTypeUnregistered) { mDNS_SetupResourceRecord(&h->arv4, mDNSNULL, mDNSInterface_Any, kDNSType_A, kHostNameTTL, kDNSRecordTypeUnregistered, AuthRecordAny, HostnameCallback, h); AssignDomainName(&h->arv4.namestorage, &h->fqdn); h->arv4.resrec.rdata->u.ipv4 = m->AdvertisedV4.ip.v4; h->arv4.state = regState_Unregistered; if (mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4)) { // If we already have a NAT query active, stop it and restart it to make sure we get another callback if (h->natinfo.clientContext) mDNS_StopNATOperation_internal(m, &h->natinfo); h->natinfo.Protocol = 0; h->natinfo.IntPort = zeroIPPort; h->natinfo.RequestedPort = zeroIPPort; h->natinfo.NATLease = 0; h->natinfo.clientCallback = hostnameGetPublicAddressCallback; h->natinfo.clientContext = h; mDNS_StartNATOperation_internal(m, &h->natinfo); } else { LogInfo("Advertising hostname %##s IPv4 %.4a", h->arv4.resrec.name->c, &m->AdvertisedV4.ip.v4); h->arv4.resrec.RecordType = kDNSRecordTypeKnownUnique; mDNS_Register_internal(m, &h->arv4); } } if (!mDNSIPv6AddressIsZero(m->AdvertisedV6.ip.v6) && h->arv6.resrec.RecordType == kDNSRecordTypeUnregistered) { mDNS_SetupResourceRecord(&h->arv6, mDNSNULL, mDNSInterface_Any, kDNSType_AAAA, kHostNameTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, HostnameCallback, h); AssignDomainName(&h->arv6.namestorage, &h->fqdn); h->arv6.resrec.rdata->u.ipv6 = m->AdvertisedV6.ip.v6; h->arv6.state = regState_Unregistered; LogInfo("Advertising hostname %##s IPv6 %.16a", h->arv6.resrec.name->c, &m->AdvertisedV6.ip.v6); mDNS_Register_internal(m, &h->arv6); } } mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { HostnameInfo *hi = (HostnameInfo *)rr->RecordContext; if (result == mStatus_MemFree) { if (hi) { // If we're still in the Hostnames list, update to new address HostnameInfo *i; LogInfo("HostnameCallback: Got mStatus_MemFree for %p %p %s", hi, rr, ARDisplayString(m, rr)); for (i = m->Hostnames; i; i = i->next) if (rr == &i->arv4 || rr == &i->arv6) { mDNS_Lock(m); AdvertiseHostname(m, i); mDNS_Unlock(m); return; } // Else, we're not still in the Hostnames list, so free the memory if (hi->arv4.resrec.RecordType == kDNSRecordTypeUnregistered && hi->arv6.resrec.RecordType == kDNSRecordTypeUnregistered) { if (hi->natinfo.clientContext) mDNS_StopNATOperation_internal(m, &hi->natinfo); hi->natinfo.clientContext = mDNSNULL; mDNSPlatformMemFree(hi); // free hi when both v4 and v6 AuthRecs deallocated } } return; } if (result) { // don't unlink or free - we can retry when we get a new address/router if (rr->resrec.rrtype == kDNSType_A) LogMsg("HostnameCallback: Error %d for registration of %##s IP %.4a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv4); else LogMsg("HostnameCallback: Error %d for registration of %##s IP %.16a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv6); if (!hi) { mDNSPlatformMemFree(rr); return; } if (rr->state != regState_Unregistered) LogMsg("Error: HostnameCallback invoked with error code for record not in regState_Unregistered!"); if (hi->arv4.state == regState_Unregistered && hi->arv6.state == regState_Unregistered) { // only deliver status if both v4 and v6 fail rr->RecordContext = (void *)hi->StatusContext; if (hi->StatusCallback) hi->StatusCallback(m, rr, result); // client may NOT make API calls here rr->RecordContext = (void *)hi; } return; } // register any pending services that require a target mDNS_Lock(m); m->NextSRVUpdate = NonZeroTime(m->timenow); mDNS_Unlock(m); // Deliver success to client if (!hi) { LogMsg("HostnameCallback invoked with orphaned address record"); return; } if (rr->resrec.rrtype == kDNSType_A) LogInfo("Registered hostname %##s IP %.4a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv4); else LogInfo("Registered hostname %##s IP %.16a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv6); rr->RecordContext = (void *)hi->StatusContext; if (hi->StatusCallback) hi->StatusCallback(m, rr, result); // client may NOT make API calls here rr->RecordContext = (void *)hi; } mDNSlocal void FoundStaticHostname(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) { const domainname *pktname = &answer->rdata->u.name; domainname *storedname = &m->StaticHostname; HostnameInfo *h = m->Hostnames; (void)question; if (answer->rdlength != 0) LogInfo("FoundStaticHostname: question %##s -> answer %##s (%s)", question->qname.c, answer->rdata->u.name.c, AddRecord ? "ADD" : "RMV"); else LogInfo("FoundStaticHostname: question %##s -> answer NULL (%s)", question->qname.c, AddRecord ? "ADD" : "RMV"); if (AddRecord && answer->rdlength != 0 && !SameDomainName(pktname, storedname)) { AssignDomainName(storedname, pktname); while (h) { if (h->arv4.state == regState_Pending || h->arv4.state == regState_NATMap || h->arv6.state == regState_Pending) { // if we're in the process of registering a dynamic hostname, delay SRV update so we don't have to reregister services if the dynamic name succeeds m->NextSRVUpdate = NonZeroTime(m->timenow + 5 * mDNSPlatformOneSecond); debugf("FoundStaticHostname: NextSRVUpdate in %d %d", m->NextSRVUpdate - m->timenow, m->timenow); return; } h = h->next; } mDNS_Lock(m); m->NextSRVUpdate = NonZeroTime(m->timenow); mDNS_Unlock(m); } else if (!AddRecord && SameDomainName(pktname, storedname)) { mDNS_Lock(m); storedname->c[0] = 0; m->NextSRVUpdate = NonZeroTime(m->timenow); mDNS_Unlock(m); } } // Called with lock held mDNSlocal void GetStaticHostname(mDNS *m) { char buf[MAX_REVERSE_MAPPING_NAME_V4]; DNSQuestion *q = &m->ReverseMap; mDNSu8 *ip = m->AdvertisedV4.ip.v4.b; mStatus err; if (m->ReverseMap.ThisQInterval != -1) return; // already running if (mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4)) return; mDNSPlatformMemZero(q, sizeof(*q)); // Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code mDNS_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa.", ip[3], ip[2], ip[1], ip[0]); if (!MakeDomainNameFromDNSNameString(&q->qname, buf)) { LogMsg("Error: GetStaticHostname - bad name %s", buf); return; } q->InterfaceID = mDNSInterface_Any; q->flags = 0; q->qtype = kDNSType_PTR; q->qclass = kDNSClass_IN; q->LongLived = mDNSfalse; q->ExpectUnique = mDNSfalse; q->ForceMCast = mDNSfalse; q->ReturnIntermed = mDNStrue; q->SuppressUnusable = mDNSfalse; q->AppendSearchDomains = 0; q->TimeoutQuestion = 0; q->WakeOnResolve = 0; q->UseBackgroundTraffic = mDNSfalse; q->ProxyQuestion = 0; q->pid = mDNSPlatformGetPID(); q->euid = 0; q->QuestionCallback = FoundStaticHostname; q->QuestionContext = mDNSNULL; LogInfo("GetStaticHostname: %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); err = mDNS_StartQuery_internal(m, q); if (err) LogMsg("Error: GetStaticHostname - StartQuery returned error %d", err); } mDNSexport void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext) { HostnameInfo **ptr = &m->Hostnames; LogInfo("mDNS_AddDynDNSHostName %##s", fqdn); while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next; if (*ptr) { LogMsg("DynDNSHostName %##s already in list", fqdn->c); return; } // allocate and format new address record *ptr = (HostnameInfo *) mDNSPlatformMemAllocateClear(sizeof(**ptr)); if (!*ptr) { LogMsg("ERROR: mDNS_AddDynDNSHostName - malloc"); return; } AssignDomainName(&(*ptr)->fqdn, fqdn); (*ptr)->arv4.state = regState_Unregistered; (*ptr)->arv6.state = regState_Unregistered; (*ptr)->StatusCallback = StatusCallback; (*ptr)->StatusContext = StatusContext; AdvertiseHostname(m, *ptr); } mDNSexport void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn) { HostnameInfo **ptr = &m->Hostnames; LogInfo("mDNS_RemoveDynDNSHostName %##s", fqdn); while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next; if (!*ptr) LogMsg("mDNS_RemoveDynDNSHostName: no such domainname %##s", fqdn->c); else { HostnameInfo *hi = *ptr; // We do it this way because, if we have no active v6 record, the "mDNS_Deregister_internal(m, &hi->arv4);" // below could free the memory, and we have to make sure we don't touch hi fields after that. mDNSBool f4 = hi->arv4.resrec.RecordType != kDNSRecordTypeUnregistered && hi->arv4.state != regState_Unregistered; mDNSBool f6 = hi->arv6.resrec.RecordType != kDNSRecordTypeUnregistered && hi->arv6.state != regState_Unregistered; *ptr = (*ptr)->next; // unlink if (f4 || f6) { if (f4) { LogInfo("mDNS_RemoveDynDNSHostName removing v4 %##s", fqdn); mDNS_Deregister_internal(m, &hi->arv4, mDNS_Dereg_normal); } if (f6) { LogInfo("mDNS_RemoveDynDNSHostName removing v6 %##s", fqdn); mDNS_Deregister_internal(m, &hi->arv6, mDNS_Dereg_normal); } // When both deregistrations complete we'll free the memory in the mStatus_MemFree callback } else { if (hi->natinfo.clientContext) { mDNS_StopNATOperation_internal(m, &hi->natinfo); hi->natinfo.clientContext = mDNSNULL; } mDNSPlatformMemFree(hi); } } mDNS_CheckLock(m); m->NextSRVUpdate = NonZeroTime(m->timenow); } // Currently called without holding the lock // Maybe we should change that? mDNSexport void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router) { mDNSBool v4Changed, v6Changed, RouterChanged; mDNSv6Addr v6; if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("mDNS_SetPrimaryInterfaceInfo: mDNS_busy (%ld) != mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); if (v4addr && v4addr->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo v4 address - incorrect type. Discarding. %#a", v4addr); return; } if (v6addr && v6addr->type != mDNSAddrType_IPv6) { LogMsg("mDNS_SetPrimaryInterfaceInfo v6 address - incorrect type. Discarding. %#a", v6addr); return; } if (router && router->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo passed non-v4 router. Discarding. %#a", router); return; } mDNS_Lock(m); v4Changed = !mDNSSameIPv4Address(m->AdvertisedV4.ip.v4, v4addr ? v4addr->ip.v4 : zerov4Addr); if (v6addr) v6 = v6addr->ip.v6; else v6 = zerov6Addr; v6Changed = !mDNSSameIPv6Address(m->AdvertisedV6.ip.v6, v6); RouterChanged = !mDNSSameIPv4Address(m->Router.ip.v4, router ? router->ip.v4 : zerov4Addr); if (v4addr && (v4Changed || RouterChanged)) debugf("mDNS_SetPrimaryInterfaceInfo: address changed from %#a to %#a", &m->AdvertisedV4, v4addr); if (v4addr) m->AdvertisedV4 = *v4addr;else m->AdvertisedV4.ip.v4 = zerov4Addr; if (v6addr) m->AdvertisedV6 = *v6addr;else m->AdvertisedV6.ip.v6 = zerov6Addr; if (router) m->Router = *router;else m->Router.ip.v4 = zerov4Addr; // setting router to zero indicates that nat mappings must be reestablished when router is reset if (v4Changed || RouterChanged || v6Changed) { HostnameInfo *i; LogInfo("mDNS_SetPrimaryInterfaceInfo: %s%s%s%#a %#a %#a", v4Changed ? "v4Changed " : "", RouterChanged ? "RouterChanged " : "", v6Changed ? "v6Changed " : "", v4addr, v6addr, router); for (i = m->Hostnames; i; i = i->next) { LogInfo("mDNS_SetPrimaryInterfaceInfo updating host name registrations for %##s", i->fqdn.c); if (i->arv4.resrec.RecordType > kDNSRecordTypeDeregistering && !mDNSSameIPv4Address(i->arv4.resrec.rdata->u.ipv4, m->AdvertisedV4.ip.v4)) { LogInfo("mDNS_SetPrimaryInterfaceInfo deregistering %s", ARDisplayString(m, &i->arv4)); mDNS_Deregister_internal(m, &i->arv4, mDNS_Dereg_normal); } if (i->arv6.resrec.RecordType > kDNSRecordTypeDeregistering && !mDNSSameIPv6Address(i->arv6.resrec.rdata->u.ipv6, m->AdvertisedV6.ip.v6)) { LogInfo("mDNS_SetPrimaryInterfaceInfo deregistering %s", ARDisplayString(m, &i->arv6)); mDNS_Deregister_internal(m, &i->arv6, mDNS_Dereg_normal); } // AdvertiseHostname will only register new address records. // For records still in the process of deregistering it will ignore them, and let the mStatus_MemFree callback handle them. AdvertiseHostname(m, i); } if (v4Changed || RouterChanged) { // If we have a non-zero IPv4 address, we should try immediately to see if we have a NAT gateway // If we have no IPv4 address, we don't want to be in quite such a hurry to report failures to our clients // Sleeping server sometimes briefly disappears over Back to My Mac after it wakes up mDNSu32 waitSeconds = v4addr ? 0 : 5; NATTraversalInfo *n; m->ExtAddress = zerov4Addr; m->LastNATMapResultCode = NATErr_None; RecreateNATMappings(m, mDNSPlatformOneSecond * waitSeconds); for (n = m->NATTraversals; n; n=n->next) n->NewAddress = zerov4Addr; LogInfo("mDNS_SetPrimaryInterfaceInfo:%s%s: recreating NAT mappings in %d seconds", v4Changed ? " v4Changed" : "", RouterChanged ? " RouterChanged" : "", waitSeconds); } if (m->ReverseMap.ThisQInterval != -1) mDNS_StopQuery_internal(m, &m->ReverseMap); m->StaticHostname.c[0] = 0; m->NextSRVUpdate = NonZeroTime(m->timenow); } mDNS_Unlock(m); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Incoming Message Processing #endif mDNSlocal mStatus ParseTSIGError(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const domainname *const displayname) { const mDNSu8 *ptr; mStatus err = mStatus_NoError; int i; ptr = LocateAdditionals(msg, end); if (!ptr) goto finish; for (i = 0; i < msg->h.numAdditionals; i++) { ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); if (!ptr) goto finish; if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_TSIG) { mDNSu32 macsize; mDNSu8 *rd = m->rec.r.resrec.rdata->u.data; mDNSu8 *rdend = rd + m->rec.r.resrec.rdlength; int alglen = DomainNameLengthLimit(&m->rec.r.resrec.rdata->u.name, rdend); if (alglen > MAX_DOMAIN_NAME) goto finish; rd += alglen; // algorithm name if (rd + 6 > rdend) goto finish; rd += 6; // 48-bit timestamp if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; rd += sizeof(mDNSOpaque16); // fudge if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; macsize = mDNSVal16(*(mDNSOpaque16 *)rd); rd += sizeof(mDNSOpaque16); // MAC size if (rd + macsize > rdend) goto finish; rd += macsize; if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; rd += sizeof(mDNSOpaque16); // orig id if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; err = mDNSVal16(*(mDNSOpaque16 *)rd); // error code if (err == TSIG_ErrBadSig) { LogMsg("%##s: bad signature", displayname->c); err = mStatus_BadSig; } else if (err == TSIG_ErrBadKey) { LogMsg("%##s: bad key", displayname->c); err = mStatus_BadKey; } else if (err == TSIG_ErrBadTime) { LogMsg("%##s: bad time", displayname->c); err = mStatus_BadTime; } else if (err) { LogMsg("%##s: unknown tsig error %d", displayname->c, err); err = mStatus_UnknownErr; } goto finish; } m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it } finish: m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it return err; } mDNSlocal mStatus checkUpdateResult(mDNS *const m, const domainname *const displayname, const mDNSu8 rcode, const DNSMessage *const msg, const mDNSu8 *const end) { (void)msg; // currently unused, needed for TSIG errors if (!rcode) return mStatus_NoError; else if (rcode == kDNSFlag1_RC_YXDomain) { debugf("name in use: %##s", displayname->c); return mStatus_NameConflict; } else if (rcode == kDNSFlag1_RC_Refused) { LogMsg("Update %##s refused", displayname->c); return mStatus_Refused; } else if (rcode == kDNSFlag1_RC_NXRRSet) { LogMsg("Reregister refused (NXRRSET): %##s", displayname->c); return mStatus_NoSuchRecord; } else if (rcode == kDNSFlag1_RC_NotAuth) { // TSIG errors should come with FormErr as per RFC 2845, but BIND 9 sends them with NotAuth so we look here too mStatus tsigerr = ParseTSIGError(m, msg, end, displayname); if (!tsigerr) { LogMsg("Permission denied (NOAUTH): %##s", displayname->c); return mStatus_UnknownErr; } else return tsigerr; } else if (rcode == kDNSFlag1_RC_FormErr) { mStatus tsigerr = ParseTSIGError(m, msg, end, displayname); if (!tsigerr) { LogMsg("Format Error: %##s", displayname->c); return mStatus_UnknownErr; } else return tsigerr; } else { LogMsg("Update %##s failed with rcode %d", displayname->c, rcode); return mStatus_UnknownErr; } } mDNSlocal mDNSu32 RRAdditionalSize(DomainAuthInfo *AuthInfo) { mDNSu32 leaseSize, tsigSize; mDNSu32 rr_base_size = 10; // type (2) class (2) TTL (4) rdlength (2) // OPT RR : Emptyname(.) + base size + rdataOPT leaseSize = 1 + rr_base_size + sizeof(rdataOPT); //TSIG: Resource Record Name + base size + RDATA // RDATA: // Algorithm name: hmac-md5.sig-alg.reg.int (8+7+3+3 + 5 bytes for length = 26 bytes) // Time: 6 bytes // Fudge: 2 bytes // Mac Size: 2 bytes // Mac: 16 bytes // ID: 2 bytes // Error: 2 bytes // Len: 2 bytes // Total: 58 bytes tsigSize = 0; if (AuthInfo) tsigSize = DomainNameLength(&AuthInfo->keyname) + rr_base_size + 58; return (leaseSize + tsigSize); } //Note: Make sure that RREstimatedSize is updated accordingly if anything that is done here //would modify rdlength/rdestimate mDNSlocal mDNSu8* BuildUpdateMessage(mDNS *const m, mDNSu8 *ptr, AuthRecord *rr, mDNSu8 *limit) { //If this record is deregistering, then just send the deletion record if (rr->state == regState_DeregPending) { rr->expire = 0; // Indicate that we have no active registration any more ptr = putDeletionRecordWithLimit(&m->omsg, ptr, &rr->resrec, limit); if (!ptr) goto exit; return ptr; } // This is a common function to both sending an update in a group or individual // records separately. Hence, we change the state here. if (rr->state == regState_Registered) rr->state = regState_Refresh; if (rr->state != regState_Refresh && rr->state != regState_UpdatePending) rr->state = regState_Pending; // For Advisory records like e.g., _services._dns-sd, which is shared, don't send goodbyes as multiple // host might be registering records and deregistering from one does not make sense if (rr->resrec.RecordType != kDNSRecordTypeAdvisory) rr->RequireGoodbye = mDNStrue; if ((rr->resrec.rrtype == kDNSType_SRV) && (rr->AutoTarget == Target_AutoHostAndNATMAP) && !mDNSIPPortIsZero(rr->NATinfo.ExternalPort)) { rr->resrec.rdata->u.srv.port = rr->NATinfo.ExternalPort; } if (rr->state == regState_UpdatePending) { // delete old RData SetNewRData(&rr->resrec, rr->OrigRData, rr->OrigRDLen); if (!(ptr = putDeletionRecordWithLimit(&m->omsg, ptr, &rr->resrec, limit))) goto exit; // delete old rdata // add new RData SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); if (!(ptr = PutResourceRecordTTLWithLimit(&m->omsg, ptr, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit))) goto exit; } else { if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique || rr->resrec.RecordType == kDNSRecordTypeVerified) { // KnownUnique : Delete any previous value // For Unicast registrations, we don't verify that it is unique, but set to verified and hence we want to // delete any previous value ptr = putDeleteRRSetWithLimit(&m->omsg, ptr, rr->resrec.name, rr->resrec.rrtype, limit); if (!ptr) goto exit; } else if (rr->resrec.RecordType != kDNSRecordTypeShared) { // For now don't do this, until we have the logic for intelligent grouping of individual records into logical service record sets //ptr = putPrereqNameNotInUse(rr->resrec.name, &m->omsg, ptr, end); if (!ptr) goto exit; } ptr = PutResourceRecordTTLWithLimit(&m->omsg, ptr, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit); if (!ptr) goto exit; } return ptr; exit: LogMsg("BuildUpdateMessage: Error formatting message for %s", ARDisplayString(m, rr)); return mDNSNULL; } // Called with lock held mDNSlocal void SendRecordRegistration(mDNS *const m, AuthRecord *rr) { mDNSu8 *ptr = m->omsg.data; mStatus err = mStatus_UnknownErr; mDNSu8 *limit; DomainAuthInfo *AuthInfo; // For the ability to register large TXT records, we limit the single record registrations // to AbsoluteMaxDNSMessageData limit = ptr + AbsoluteMaxDNSMessageData; AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); limit -= RRAdditionalSize(AuthInfo); mDNS_CheckLock(m); if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) { // We never call this function when there is no zone information . Log a message if it ever happens. LogMsg("SendRecordRegistration: No Zone information, should not happen %s", ARDisplayString(m, rr)); return; } rr->updateid = mDNS_NewMessageID(m); InitializeDNSMessage(&m->omsg.h, rr->updateid, UpdateReqFlags); // set zone ptr = putZone(&m->omsg, ptr, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); if (!ptr) goto exit; if (!(ptr = BuildUpdateMessage(m, ptr, rr, limit))) goto exit; if (rr->uselease) { ptr = putUpdateLeaseWithLimit(&m->omsg, ptr, DEFAULT_UPDATE_LEASE, limit); if (!ptr) goto exit; } if (rr->Private) { LogInfo("SendRecordRegistration TCP %p %s", rr->tcp, ARDisplayString(m, rr)); if (rr->tcp) LogInfo("SendRecordRegistration: Disposing existing TCP connection for %s", ARDisplayString(m, rr)); if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } if (!rr->nta) { LogMsg("SendRecordRegistration:Private:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } rr->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &rr->nta->Addr, rr->nta->Port, &rr->nta->Host, mDNSNULL, rr); } else { LogInfo("SendRecordRegistration UDP %s", ARDisplayString(m, rr)); if (!rr->nta) { LogMsg("SendRecordRegistration:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, mDNSNULL, &rr->nta->Addr, rr->nta->Port, GetAuthInfoForName_internal(m, rr->resrec.name), mDNSfalse); if (err) debugf("ERROR: SendRecordRegistration - mDNSSendDNSMessage - %d", err); } SetRecordRetry(m, rr, 0); return; exit: LogMsg("SendRecordRegistration: Error formatting message for %s, disabling further updates", ARDisplayString(m, rr)); // Disable this record from future updates rr->state = regState_NoTarget; } // Is the given record "rr" eligible for merging ? mDNSlocal mDNSBool IsRecordMergeable(mDNS *const m, AuthRecord *rr, mDNSs32 time) { DomainAuthInfo *info; // A record is eligible for merge, if the following properties are met. // // 1. uDNS Resource Record // 2. It is time to send them now // 3. It is in proper state // 4. Update zone has been resolved // 5. if DomainAuthInfo exists for the zone, it should not be soon deleted // 6. Zone information is present // 7. Update server is not zero // 8. It has a non-null zone // 9. It uses a lease option // 10. DontMerge is not set // // Following code is implemented as separate "if" statements instead of one "if" statement // is for better debugging purposes e.g., we know exactly what failed if debugging turned on. if (!AuthRecord_uDNS(rr)) return mDNSfalse; if (rr->LastAPTime + rr->ThisAPInterval - time > 0) { debugf("IsRecordMergeable: Time %d not reached for %s", rr->LastAPTime + rr->ThisAPInterval - m->timenow, ARDisplayString(m, rr)); return mDNSfalse; } if (!rr->zone) return mDNSfalse; info = GetAuthInfoForName_internal(m, rr->zone); if (info && info->deltime && m->timenow - info->deltime >= 0) {debugf("IsRecordMergeable: Domain %##s will be deleted soon", info->domain.c); return mDNSfalse;} if (rr->state != regState_DeregPending && rr->state != regState_Pending && rr->state != regState_Registered && rr->state != regState_Refresh && rr->state != regState_UpdatePending) { debugf("IsRecordMergeable: state %d not right %s", rr->state, ARDisplayString(m, rr)); return mDNSfalse; } if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) return mDNSfalse; if (!rr->uselease) return mDNSfalse; if (rr->mState == mergeState_DontMerge) {debugf("IsRecordMergeable Dontmerge true %s", ARDisplayString(m, rr)); return mDNSfalse;} debugf("IsRecordMergeable: Returning true for %s", ARDisplayString(m, rr)); return mDNStrue; } // Is the resource record "rr" eligible to merge to with "currentRR" ? mDNSlocal mDNSBool AreRecordsMergeable(mDNS *const m, AuthRecord *currentRR, AuthRecord *rr, mDNSs32 time) { // A record is eligible to merge with another record as long it is eligible for merge in itself // and it has the same zone information as the other record if (!IsRecordMergeable(m, rr, time)) return mDNSfalse; if (!SameDomainName(currentRR->zone, rr->zone)) { debugf("AreRecordMergeable zone mismatch current rr Zone %##s, rr zone %##s", currentRR->zone->c, rr->zone->c); return mDNSfalse; } if (!mDNSSameIPv4Address(currentRR->nta->Addr.ip.v4, rr->nta->Addr.ip.v4)) return mDNSfalse; if (!mDNSSameIPPort(currentRR->nta->Port, rr->nta->Port)) return mDNSfalse; debugf("AreRecordsMergeable: Returning true for %s", ARDisplayString(m, rr)); return mDNStrue; } // If we can't build the message successfully because of problems in pre-computing // the space, we disable merging for all the current records mDNSlocal void RRMergeFailure(mDNS *const m) { AuthRecord *rr; for (rr = m->ResourceRecords; rr; rr = rr->next) { rr->mState = mergeState_DontMerge; rr->SendRNow = mDNSNULL; // Restarting the registration is much simpler than saving and restoring // the exact time ActivateUnicastRegistration(m, rr); } } mDNSlocal void SendGroupRRMessage(mDNS *const m, AuthRecord *anchorRR, mDNSu8 *ptr, DomainAuthInfo *info) { mDNSu8 *limit; if (!anchorRR) {debugf("SendGroupRRMessage: Could not merge records"); return;} limit = m->omsg.data + NormalMaxDNSMessageData; // This has to go in the additional section and hence need to be done last ptr = putUpdateLeaseWithLimit(&m->omsg, ptr, DEFAULT_UPDATE_LEASE, limit); if (!ptr) { LogMsg("SendGroupRRMessage: ERROR: Could not put lease option, failing the group registration"); // if we can't put the lease, we need to undo the merge RRMergeFailure(m); return; } if (anchorRR->Private) { if (anchorRR->tcp) debugf("SendGroupRRMessage: Disposing existing TCP connection for %s", ARDisplayString(m, anchorRR)); if (anchorRR->tcp) { DisposeTCPConn(anchorRR->tcp); anchorRR->tcp = mDNSNULL; } if (!anchorRR->nta) { LogMsg("SendGroupRRMessage:ERROR!! nta is NULL for %s", ARDisplayString(m, anchorRR)); return; } anchorRR->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &anchorRR->nta->Addr, anchorRR->nta->Port, &anchorRR->nta->Host, mDNSNULL, anchorRR); if (!anchorRR->tcp) LogInfo("SendGroupRRMessage: Cannot establish TCP connection for %s", ARDisplayString(m, anchorRR)); else LogInfo("SendGroupRRMessage: Sent a group update ID: %d start %p, end %p, limit %p", mDNSVal16(m->omsg.h.id), m->omsg.data, ptr, limit); } else { mStatus err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, mDNSNULL, &anchorRR->nta->Addr, anchorRR->nta->Port, info, mDNSfalse); if (err) LogInfo("SendGroupRRMessage: Cannot send UDP message for %s", ARDisplayString(m, anchorRR)); else LogInfo("SendGroupRRMessage: Sent a group UDP update ID: %d start %p, end %p, limit %p", mDNSVal16(m->omsg.h.id), m->omsg.data, ptr, limit); } return; } // As we always include the zone information and the resource records contain zone name // at the end, it will get compressed. Hence, we subtract zoneSize and add two bytes for // the compression pointer mDNSlocal mDNSu32 RREstimatedSize(AuthRecord *rr, int zoneSize) { int rdlength; // Note: Estimation of the record size has to mirror the logic in BuildUpdateMessage, otherwise estimation // would be wrong. Currently BuildUpdateMessage calls SetNewRData in UpdatePending case. Hence, we need // to account for that here. Otherwise, we might under estimate the size. if (rr->state == regState_UpdatePending) // old RData that will be deleted // new RData that will be added rdlength = rr->OrigRDLen + rr->InFlightRDLen; else rdlength = rr->resrec.rdestimate; if (rr->state == regState_DeregPending) { debugf("RREstimatedSize: ResourceRecord %##s (%s), DomainNameLength %d, zoneSize %d, rdestimate %d", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), DomainNameLength(rr->resrec.name), zoneSize, rdlength); return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + rdlength; } // For SRV, TXT, AAAA etc. that are Unique/Verified, we also send a Deletion Record if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique || rr->resrec.RecordType == kDNSRecordTypeVerified) { // Deletion Record: Resource Record Name + Base size (10) + 0 // Record: Resource Record Name (Compressed = 2) + Base size (10) + rdestimate debugf("RREstimatedSize: ResourceRecord %##s (%s), DomainNameLength %d, zoneSize %d, rdestimate %d", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), DomainNameLength(rr->resrec.name), zoneSize, rdlength); return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + 2 + 10 + rdlength; } else { return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + rdlength; } } mDNSlocal AuthRecord *MarkRRForSending(mDNS *const m) { AuthRecord *rr; AuthRecord *firstRR = mDNSNULL; // Look for records that needs to be sent in the next two seconds (MERGE_DELAY_TIME is set to 1 second). // The logic is as follows. // // 1. Record 1 finishes getting zone data and its registration gets delayed by 1 second // 2. Record 2 comes 0.1 second later, finishes getting its zone data and its registration is also delayed by // 1 second which is now scheduled at 1.1 second // // By looking for 1 second into the future (m->timenow + MERGE_DELAY_TIME below does that) we have merged both // of the above records. Note that we can't look for records too much into the future as this will affect the // retry logic. The first retry is scheduled at 3 seconds. Hence, we should always look smaller than that. // Anything more than one second will affect the first retry to happen sooner. // // Note: As a side effect of looking one second into the future to facilitate merging, the retries happen // one second sooner. for (rr = m->ResourceRecords; rr; rr = rr->next) { if (!firstRR) { if (!IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) continue; firstRR = rr; } else if (!AreRecordsMergeable(m, firstRR, rr, m->timenow + MERGE_DELAY_TIME)) continue; if (rr->SendRNow) LogMsg("MarkRRForSending: Resourcerecord %s already marked for sending", ARDisplayString(m, rr)); rr->SendRNow = uDNSInterfaceMark; } // We parsed through all records and found something to send. The services/records might // get registered at different times but we want the refreshes to be all merged and sent // as one update. Hence, we accelerate some of the records so that they will sync up in // the future. Look at the records excluding the ones that we have already sent in the // previous pass. If it half way through its scheduled refresh/retransmit, merge them // into this packet. // // Note that we only look at Registered/Refresh state to keep it simple. As we don't know // whether the current update will fit into one or more packets, merging a resource record // (which is in a different state) that has been scheduled for retransmit would trigger // sending more packets. if (firstRR) { int acc = 0; for (rr = m->ResourceRecords; rr; rr = rr->next) { if ((rr->state != regState_Registered && rr->state != regState_Refresh) || (rr->SendRNow == uDNSInterfaceMark) || (!AreRecordsMergeable(m, firstRR, rr, m->timenow + rr->ThisAPInterval/2))) continue; rr->SendRNow = uDNSInterfaceMark; acc++; } if (acc) LogInfo("MarkRRForSending: Accelereated %d records", acc); } return firstRR; } mDNSlocal mDNSBool SendGroupUpdates(mDNS *const m) { mDNSOpaque16 msgid; mDNSs32 spaceleft = 0; mDNSs32 zoneSize, rrSize; mDNSu8 *oldnext; // for debugging mDNSu8 *next = m->omsg.data; AuthRecord *rr; AuthRecord *anchorRR = mDNSNULL; int nrecords = 0; AuthRecord *startRR = m->ResourceRecords; mDNSu8 *limit = mDNSNULL; DomainAuthInfo *AuthInfo = mDNSNULL; mDNSBool sentallRecords = mDNStrue; // We try to fit as many ResourceRecords as possible in AbsoluteNormal/MaxDNSMessageData. Before we start // putting in resource records, we need to reserve space for a few things. Every group/packet should // have the following. // // 1) Needs space for the Zone information (which needs to be at the beginning) // 2) Additional section MUST have space for lease option, HINFO and TSIG option (which needs to // to be at the end) // // In future we need to reserve space for the pre-requisites which also goes at the beginning. // To accomodate pre-requisites in the future, first we walk the whole list marking records // that can be sent in this packet and computing the space needed for these records. // For TXT and SRV records, we delete the previous record if any by sending the same // resource record with ANY RDATA and zero rdlen. Hence, we need to have space for both of them. while (startRR) { AuthInfo = mDNSNULL; anchorRR = mDNSNULL; nrecords = 0; zoneSize = 0; for (rr = startRR; rr; rr = rr->next) { if (rr->SendRNow != uDNSInterfaceMark) continue; rr->SendRNow = mDNSNULL; if (!anchorRR) { AuthInfo = GetAuthInfoForName_internal(m, rr->zone); // Though we allow single record registrations for UDP to be AbsoluteMaxDNSMessageData (See // SendRecordRegistration) to handle large TXT records, to avoid fragmentation we limit UDP // message to NormalMaxDNSMessageData spaceleft = NormalMaxDNSMessageData; next = m->omsg.data; spaceleft -= RRAdditionalSize(AuthInfo); if (spaceleft <= 0) { LogMsg("SendGroupUpdates: ERROR!!: spaceleft is zero at the beginning"); RRMergeFailure(m); return mDNSfalse; } limit = next + spaceleft; // Build the initial part of message before putting in the other records msgid = mDNS_NewMessageID(m); InitializeDNSMessage(&m->omsg.h, msgid, UpdateReqFlags); // We need zone information at the beginning of the packet. Length: ZNAME, ZTYPE(2), ZCLASS(2) // zone has to be non-NULL for a record to be mergeable, hence it is safe to set/ examine zone //without checking for NULL. zoneSize = DomainNameLength(rr->zone) + 4; spaceleft -= zoneSize; if (spaceleft <= 0) { LogMsg("SendGroupUpdates: ERROR no space for zone information, disabling merge"); RRMergeFailure(m); return mDNSfalse; } next = putZone(&m->omsg, next, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); if (!next) { LogMsg("SendGroupUpdates: ERROR! Cannot put zone, disabling merge"); RRMergeFailure(m); return mDNSfalse; } anchorRR = rr; } rrSize = RREstimatedSize(rr, zoneSize - 4); if ((spaceleft - rrSize) < 0) { // If we can't fit even a single message, skip it, it will be sent separately // in CheckRecordUpdates if (!nrecords) { LogInfo("SendGroupUpdates: Skipping message %s, spaceleft %d, rrSize %d", ARDisplayString(m, rr), spaceleft, rrSize); // Mark this as not sent so that the caller knows about it rr->SendRNow = uDNSInterfaceMark; // We need to remove the merge delay so that we can send it immediately rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; rr = rr->next; anchorRR = mDNSNULL; sentallRecords = mDNSfalse; } else { LogInfo("SendGroupUpdates:1: Parsed %d records and sending using %s, spaceleft %d, rrSize %d", nrecords, ARDisplayString(m, anchorRR), spaceleft, rrSize); SendGroupRRMessage(m, anchorRR, next, AuthInfo); } break; // breaks out of for loop } spaceleft -= rrSize; oldnext = next; LogInfo("SendGroupUpdates: Building a message with resource record %s, next %p, state %d, ttl %d", ARDisplayString(m, rr), next, rr->state, rr->resrec.rroriginalttl); if (!(next = BuildUpdateMessage(m, next, rr, limit))) { // We calculated the space and if we can't fit in, we had some bug in the calculation, // disable merge completely. LogMsg("SendGroupUpdates: ptr NULL while building message with %s", ARDisplayString(m, rr)); RRMergeFailure(m); return mDNSfalse; } // If our estimate was higher, adjust to the actual size if ((next - oldnext) > rrSize) LogMsg("SendGroupUpdates: ERROR!! Record size estimation is wrong for %s, Estimate %d, Actual %d, state %d", ARDisplayString(m, rr), rrSize, next - oldnext, rr->state); else { spaceleft += rrSize; spaceleft -= (next - oldnext); } nrecords++; // We could have sent an update earlier with this "rr" as anchorRR for which we never got a response. // To preserve ordering, we blow away the previous connection before sending this. if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL;} rr->updateid = msgid; // By setting the retry time interval here, we will not be looking at these records // again when we return to CheckGroupRecordUpdates. SetRecordRetry(m, rr, 0); } // Either we have parsed all the records or stopped at "rr" above due to lack of space startRR = rr; } if (anchorRR) { LogInfo("SendGroupUpdates: Parsed %d records and sending using %s", nrecords, ARDisplayString(m, anchorRR)); SendGroupRRMessage(m, anchorRR, next, AuthInfo); } return sentallRecords; } // Merge the record registrations and send them as a group only if they // have same DomainAuthInfo and hence the same key to put the TSIG mDNSlocal void CheckGroupRecordUpdates(mDNS *const m) { AuthRecord *rr, *nextRR; // Keep sending as long as there is at least one record to be sent while (MarkRRForSending(m)) { if (!SendGroupUpdates(m)) { // if everything that was marked was not sent, send them out individually for (rr = m->ResourceRecords; rr; rr = nextRR) { // SendRecordRegistrtion might delete the rr from list, hence // dereference nextRR before calling the function nextRR = rr->next; if (rr->SendRNow == uDNSInterfaceMark) { // Any records marked for sending should be eligible to be sent out // immediately. Just being cautious if (rr->LastAPTime + rr->ThisAPInterval - m->timenow > 0) { LogMsg("CheckGroupRecordUpdates: ERROR!! Resourcerecord %s not ready", ARDisplayString(m, rr)); continue; } rr->SendRNow = mDNSNULL; SendRecordRegistration(m, rr); } } } } debugf("CheckGroupRecordUpdates: No work, returning"); return; } mDNSlocal void hndlSRVChanged(mDNS *const m, AuthRecord *rr) { // Reevaluate the target always as NAT/Target could have changed while // we were registering/deeregistering domainname *dt; const domainname *target = GetServiceTarget(m, rr); if (!target || target->c[0] == 0) { // we don't have a target, if we just derregistered, then we don't have to do anything if (rr->state == regState_DeregPending) { LogInfo("hndlSRVChanged: SRVChanged, No Target, SRV Deregistered for %##s, state %d", rr->resrec.name->c, rr->state); rr->SRVChanged = mDNSfalse; dt = GetRRDomainNameTarget(&rr->resrec); if (dt) dt->c[0] = 0; rr->state = regState_NoTarget; // Wait for the next target change rr->resrec.rdlength = rr->resrec.rdestimate = 0; return; } // we don't have a target, if we just registered, we need to deregister if (rr->state == regState_Pending) { LogInfo("hndlSRVChanged: SRVChanged, No Target, Deregistering again %##s, state %d", rr->resrec.name->c, rr->state); rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; rr->state = regState_DeregPending; return; } LogInfo("hndlSRVChanged: Not in DeregPending or RegPending state %##s, state %d", rr->resrec.name->c, rr->state); } else { // If we were in registered state and SRV changed to NULL, we deregister and come back here // if we have a target, we need to register again. // // if we just registered check to see if it is same. If it is different just re-register the // SRV and its assoicated records // // UpdateOneSRVRecord takes care of re-registering all service records if ((rr->state == regState_DeregPending) || (rr->state == regState_Pending && !SameDomainName(target, &rr->resrec.rdata->u.srv.target))) { dt = GetRRDomainNameTarget(&rr->resrec); if (dt) dt->c[0] = 0; rr->state = regState_NoTarget; // NoTarget will allow us to pick up new target OR nat traversal state rr->resrec.rdlength = rr->resrec.rdestimate = 0; LogInfo("hndlSRVChanged: SRVChanged, Valid Target %##s, Registering all records for %##s, state %d", target->c, rr->resrec.name->c, rr->state); rr->SRVChanged = mDNSfalse; UpdateOneSRVRecord(m, rr); return; } // Target did not change while this record was registering. Hence, we go to // Registered state - the state we started from. if (rr->state == regState_Pending) rr->state = regState_Registered; } rr->SRVChanged = mDNSfalse; } // Called with lock held mDNSlocal void hndlRecordUpdateReply(mDNS *m, AuthRecord *rr, mStatus err, mDNSu32 random) { mDNSBool InvokeCallback = mDNStrue; mDNSIPPort UpdatePort = zeroIPPort; mDNS_CheckLock(m); LogInfo("hndlRecordUpdateReply: err %d ID %d state %d %s(%p)", err, mDNSVal16(rr->updateid), rr->state, ARDisplayString(m, rr), rr); rr->updateError = err; SetRecordRetry(m, rr, random); rr->updateid = zeroID; // Make sure that this is not considered as part of a group anymore // Later when need to send an update, we will get the zone data again. Thus we avoid // using stale information. // // Note: By clearing out the zone info here, it also helps better merging of records // in some cases. For example, when we get out regState_NoTarget state e.g., move out // of Double NAT, we want all the records to be in one update. Some BTMM records like // _autotunnel6 and host records are registered/deregistered when NAT state changes. // As they are re-registered the zone information is cleared out. To merge with other // records that might be possibly going out, clearing out the information here helps // as all of them try to get the zone data. if (rr->nta) { // We always expect the question to be stopped when we get a valid response from the server. // If the zone info tries to change during this time, updateid would be different and hence // this response should not have been accepted. if (rr->nta->question.ThisQInterval != -1) LogMsg("hndlRecordUpdateReply: ResourceRecord %s, zone info question %##s (%s) interval %d not -1", ARDisplayString(m, rr), rr->nta->question.qname.c, DNSTypeName(rr->nta->question.qtype), rr->nta->question.ThisQInterval); UpdatePort = rr->nta->Port; CancelGetZoneData(m, rr->nta); rr->nta = mDNSNULL; } // If we are deregistering the record, then complete the deregistration. Ignore any NAT/SRV change // that could have happened during that time. if (rr->resrec.RecordType == kDNSRecordTypeDeregistering && rr->state == regState_DeregPending) { debugf("hndlRecordUpdateReply: Received reply for deregister record %##s type %d", rr->resrec.name->c, rr->resrec.rrtype); if (err) LogMsg("ERROR: Deregistration of record %##s type %d failed with error %d", rr->resrec.name->c, rr->resrec.rrtype, err); rr->state = regState_Unregistered; CompleteDeregistration(m, rr); return; } // We are returning early without updating the state. When we come back from sleep we will re-register after // re-initializing all the state as though it is a first registration. If the record can't be registered e.g., // no target, it will be deregistered. Hence, the updating to the right state should not matter when going // to sleep. if (m->SleepState) { // Need to set it to NoTarget state so that RecordReadyForSleep knows that // we are done if (rr->resrec.rrtype == kDNSType_SRV && rr->state == regState_DeregPending) rr->state = regState_NoTarget; return; } if (rr->state == regState_UpdatePending) { if (err) LogMsg("Update record failed for %##s (err %d)", rr->resrec.name->c, err); rr->state = regState_Registered; // deallocate old RData if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->OrigRData, rr->OrigRDLen); SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); rr->OrigRData = mDNSNULL; rr->InFlightRData = mDNSNULL; } if (rr->SRVChanged) { if (rr->resrec.rrtype == kDNSType_SRV) hndlSRVChanged(m, rr); else { LogInfo("hndlRecordUpdateReply: Deregistered %##s (%s), state %d", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), rr->state); rr->SRVChanged = mDNSfalse; if (rr->state != regState_DeregPending) LogMsg("hndlRecordUpdateReply: ResourceRecord %s not in DeregPending state %d", ARDisplayString(m, rr), rr->state); rr->state = regState_NoTarget; // Wait for the next target change } return; } if (rr->state == regState_Pending || rr->state == regState_Refresh) { if (!err) { if (rr->state == regState_Refresh) InvokeCallback = mDNSfalse; rr->state = regState_Registered; } else { // Retry without lease only for non-Private domains LogMsg("hndlRecordUpdateReply: Registration of record %##s type %d failed with error %d", rr->resrec.name->c, rr->resrec.rrtype, err); if (!rr->Private && rr->uselease && err == mStatus_UnknownErr && mDNSSameIPPort(UpdatePort, UnicastDNSPort)) { LogMsg("hndlRecordUpdateReply: Will retry update of record %##s without lease option", rr->resrec.name->c); rr->uselease = mDNSfalse; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; SetNextuDNSEvent(m, rr); return; } // Communicate the error to the application in the callback below } } if (rr->QueuedRData && rr->state == regState_Registered) { rr->state = regState_UpdatePending; rr->InFlightRData = rr->QueuedRData; rr->InFlightRDLen = rr->QueuedRDLen; rr->OrigRData = rr->resrec.rdata; rr->OrigRDLen = rr->resrec.rdlength; rr->QueuedRData = mDNSNULL; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; SetNextuDNSEvent(m, rr); return; } // Don't invoke the callback on error as this may not be useful to the client. // The client may potentially delete the resource record on error which we normally // delete during deregistration if (!err && InvokeCallback && rr->RecordCallback) { LogInfo("hndlRecordUpdateReply: Calling record callback on %##s", rr->resrec.name->c); mDNS_DropLockBeforeCallback(); rr->RecordCallback(m, rr, err); mDNS_ReclaimLockAfterCallback(); } // CAUTION: MUST NOT do anything more with rr after calling rr->Callback(), because the client's callback function // is allowed to do anything, including starting/stopping queries, registering/deregistering records, etc. } mDNSlocal void uDNS_ReceiveNATPMPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) { NATTraversalInfo *ptr; NATAddrReply *AddrReply = (NATAddrReply *)pkt; NATPortMapReply *PortMapReply = (NATPortMapReply *)pkt; mDNSu32 nat_elapsed, our_elapsed; // Minimum NAT-PMP packet is vers (1) opcode (1) + err (2) = 4 bytes if (len < 4) { LogMsg("NAT-PMP message too short (%d bytes)", len); return; } // Read multi-byte error value (field is identical in a NATPortMapReply) AddrReply->err = (mDNSu16) ((mDNSu16)pkt[2] << 8 | pkt[3]); if (AddrReply->err == NATErr_Vers) { NATTraversalInfo *n; LogInfo("NAT-PMP version unsupported message received"); for (n = m->NATTraversals; n; n=n->next) { // Send a NAT-PMP request for this operation as needed // and update the state variables uDNS_SendNATMsg(m, n, mDNSfalse, mDNSfalse); } m->NextScheduledNATOp = m->timenow; return; } // The minimum reasonable NAT-PMP packet length is vers (1) + opcode (1) + err (2) + upseconds (4) = 8 bytes // If it's not at least this long, bail before we byte-swap the upseconds field & overrun our buffer. // The retry timer will ensure we converge to correctness. if (len < 8) { LogMsg("NAT-PMP message too short (%d bytes) 0x%X 0x%X", len, AddrReply->opcode, AddrReply->err); return; } // Read multi-byte upseconds value (field is identical in a NATPortMapReply) AddrReply->upseconds = (mDNSs32) ((mDNSs32)pkt[4] << 24 | (mDNSs32)pkt[5] << 16 | (mDNSs32)pkt[6] << 8 | pkt[7]); nat_elapsed = AddrReply->upseconds - m->LastNATupseconds; our_elapsed = (m->timenow - m->LastNATReplyLocalTime) / mDNSPlatformOneSecond; debugf("uDNS_ReceiveNATPMPPacket %X upseconds %u nat_elapsed %d our_elapsed %d", AddrReply->opcode, AddrReply->upseconds, nat_elapsed, our_elapsed); // We compute a conservative estimate of how much the NAT gateways's clock should have advanced // 1. We subtract 12.5% from our own measured elapsed time, to allow for NAT gateways that have an inacurate clock that runs slowly // 2. We add a two-second safety margin to allow for rounding errors: e.g. // -- if NAT gateway sends a packet at t=2.000 seconds, then one at t=7.999, that's approximately 6 real seconds, // but based on the values in the packet (2,7) the apparent difference according to the packet is only 5 seconds // -- if we're slow handling packets and/or we have coarse clock granularity, // we could receive the t=2 packet at our t=1.999 seconds, which we round down to 1 // and the t=7.999 packet at our t=8.000 seconds, which we record as 8, // giving an apparent local time difference of 7 seconds // The two-second safety margin coves this possible calculation discrepancy if (AddrReply->upseconds < m->LastNATupseconds || nat_elapsed + 2 < our_elapsed - our_elapsed/8) { LogMsg("NAT-PMP epoch time check failed: assuming NAT gateway %#a rebooted", &m->Router); RecreateNATMappings(m, 0); } m->LastNATupseconds = AddrReply->upseconds; m->LastNATReplyLocalTime = m->timenow; #ifdef _LEGACY_NAT_TRAVERSAL_ LNT_ClearState(m); #endif // _LEGACY_NAT_TRAVERSAL_ if (AddrReply->opcode == NATOp_AddrResponse) { #if APPLE_OSX_mDNSResponder LogInfo("uDNS_ReceiveNATPMPPacket: AddressRequest %s error %d", AddrReply->err ? "failure" : "success", AddrReply->err); #endif if (!AddrReply->err && len < sizeof(NATAddrReply)) { LogMsg("NAT-PMP AddrResponse message too short (%d bytes)", len); return; } natTraversalHandleAddressReply(m, AddrReply->err, AddrReply->ExtAddr); } else if (AddrReply->opcode == NATOp_MapUDPResponse || AddrReply->opcode == NATOp_MapTCPResponse) { mDNSu8 Protocol = AddrReply->opcode & 0x7F; #if APPLE_OSX_mDNSResponder LogInfo("uDNS_ReceiveNATPMPPacket: PortMapRequest %s %s - error %d", PortMapReply->err ? "failure" : "success", (AddrReply->opcode == NATOp_MapUDPResponse) ? "UDP" : "TCP", PortMapReply->err); #endif if (!PortMapReply->err) { if (len < sizeof(NATPortMapReply)) { LogMsg("NAT-PMP PortMapReply message too short (%d bytes)", len); return; } PortMapReply->NATRep_lease = (mDNSu32) ((mDNSu32)pkt[12] << 24 | (mDNSu32)pkt[13] << 16 | (mDNSu32)pkt[14] << 8 | pkt[15]); } // Since some NAT-PMP server implementations don't return the requested internal port in // the reply, we can't associate this reply with a particular NATTraversalInfo structure. // We globally keep track of the most recent error code for mappings. m->LastNATMapResultCode = PortMapReply->err; for (ptr = m->NATTraversals; ptr; ptr=ptr->next) if (ptr->Protocol == Protocol && mDNSSameIPPort(ptr->IntPort, PortMapReply->intport)) natTraversalHandlePortMapReply(m, ptr, InterfaceID, PortMapReply->err, PortMapReply->extport, PortMapReply->NATRep_lease, NATTProtocolNATPMP); } else { LogMsg("Received NAT-PMP response with unknown opcode 0x%X", AddrReply->opcode); return; } // Don't need an SSDP socket if we get a NAT-PMP packet if (m->SSDPSocket) { debugf("uDNS_ReceiveNATPMPPacket destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } } mDNSlocal void uDNS_ReceivePCPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) { NATTraversalInfo *ptr; PCPMapReply *reply = (PCPMapReply*)pkt; mDNSu32 client_delta, server_delta; mDNSBool checkEpochValidity = m->LastNATupseconds != 0; mDNSu8 strippedOpCode; mDNSv4Addr mappedAddress = zerov4Addr; mDNSu8 protocol = 0; mDNSIPPort intport = zeroIPPort; mDNSIPPort extport = zeroIPPort; // Minimum PCP packet is 24 bytes if (len < 24) { LogMsg("uDNS_ReceivePCPPacket: message too short (%d bytes)", len); return; } strippedOpCode = reply->opCode & 0x7f; if ((reply->opCode & 0x80) == 0x00 || (strippedOpCode != PCPOp_Announce && strippedOpCode != PCPOp_Map)) { LogMsg("uDNS_ReceivePCPPacket: unhandled opCode %u", reply->opCode); return; } // Read multi-byte values reply->lifetime = (mDNSs32)((mDNSs32)pkt[4] << 24 | (mDNSs32)pkt[5] << 16 | (mDNSs32)pkt[ 6] << 8 | pkt[ 7]); reply->epoch = (mDNSs32)((mDNSs32)pkt[8] << 24 | (mDNSs32)pkt[9] << 16 | (mDNSs32)pkt[10] << 8 | pkt[11]); client_delta = (m->timenow - m->LastNATReplyLocalTime) / mDNSPlatformOneSecond; server_delta = reply->epoch - m->LastNATupseconds; debugf("uDNS_ReceivePCPPacket: %X %X upseconds %u client_delta %d server_delta %d", reply->opCode, reply->result, reply->epoch, client_delta, server_delta); // If seconds since the epoch is 0, use 1 so we'll check epoch validity next time m->LastNATupseconds = reply->epoch ? reply->epoch : 1; m->LastNATReplyLocalTime = m->timenow; #ifdef _LEGACY_NAT_TRAVERSAL_ LNT_ClearState(m); #endif // _LEGACY_NAT_TRAVERSAL_ // Don't need an SSDP socket if we get a PCP packet if (m->SSDPSocket) { debugf("uDNS_ReceivePCPPacket: destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } if (checkEpochValidity && (client_delta + 2 < server_delta - server_delta / 16 || server_delta + 2 < client_delta - client_delta / 16)) { // If this is an ANNOUNCE packet, wait a random interval up to 5 seconds // otherwise, refresh immediately mDNSu32 waitTicks = strippedOpCode ? 0 : mDNSRandom(PCP_WAITSECS_AFTER_EPOCH_INVALID * mDNSPlatformOneSecond); LogMsg("uDNS_ReceivePCPPacket: Epoch invalid, %#a likely rebooted, waiting %u ticks", &m->Router, waitTicks); RecreateNATMappings(m, waitTicks); // we can ignore the rest of this packet, as new requests are about to go out return; } if (strippedOpCode == PCPOp_Announce) return; // We globally keep track of the most recent error code for mappings. // This seems bad to do with PCP, but best not change it now. m->LastNATMapResultCode = reply->result; if (!reply->result) { if (len < sizeof(PCPMapReply)) { LogMsg("uDNS_ReceivePCPPacket: mapping response too short (%d bytes)", len); return; } // Check the nonce if (reply->nonce[0] != m->PCPNonce[0] || reply->nonce[1] != m->PCPNonce[1] || reply->nonce[2] != m->PCPNonce[2]) { LogMsg("uDNS_ReceivePCPPacket: invalid nonce, ignoring. received { %x %x %x } expected { %x %x %x }", reply->nonce[0], reply->nonce[1], reply->nonce[2], m->PCPNonce[0], m->PCPNonce[1], m->PCPNonce[2]); return; } // Get the values protocol = reply->protocol; intport = reply->intPort; extport = reply->extPort; // Get the external address, which should be mapped, since we only support IPv4 if (!mDNSAddrIPv4FromMappedIPv6(&reply->extAddress, &mappedAddress)) { LogMsg("uDNS_ReceivePCPPacket: unexpected external address: %.16a", &reply->extAddress); reply->result = NATErr_NetFail; // fall through to report the error } else if (mDNSIPv4AddressIsZero(mappedAddress)) { // If this is the deletion case, we will have sent the zero IPv4-mapped address // in our request, and the server should reflect it in the response, so we // should not log about receiving a zero address. And in this case, we no // longer have a NATTraversal to report errors back to, so it's ok to set the // result here. // In other cases, a zero address is an error, and we will have a NATTraversal // to report back to, so set an error and fall through to report it. // CheckNATMappings will log the error. reply->result = NATErr_NetFail; } } else { LogInfo("uDNS_ReceivePCPPacket: error received from server. opcode %X result %X lifetime %X epoch %X", reply->opCode, reply->result, reply->lifetime, reply->epoch); // If the packet is long enough, get the protocol & intport for matching to report // the error if (len >= sizeof(PCPMapReply)) { protocol = reply->protocol; intport = reply->intPort; } } for (ptr = m->NATTraversals; ptr; ptr=ptr->next) { mDNSu8 ptrProtocol = ((ptr->Protocol & NATOp_MapTCP) == NATOp_MapTCP ? PCPProto_TCP : PCPProto_UDP); if ((protocol == ptrProtocol && mDNSSameIPPort(ptr->IntPort, intport)) || (!ptr->Protocol && protocol == PCPProto_TCP && mDNSSameIPPort(DiscardPort, intport))) { natTraversalHandlePortMapReplyWithAddress(m, ptr, InterfaceID, reply->result ? NATErr_NetFail : NATErr_None, mappedAddress, extport, reply->lifetime, NATTProtocolPCP); } } } mDNSexport void uDNS_ReceiveNATPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) { if (len == 0) LogMsg("uDNS_ReceiveNATPacket: zero length packet"); else if (pkt[0] == PCP_VERS) uDNS_ReceivePCPPacket(m, InterfaceID, pkt, len); else if (pkt[0] == NATMAP_VERS) uDNS_ReceiveNATPMPPacket(m, InterfaceID, pkt, len); else LogMsg("uDNS_ReceiveNATPacket: packet with version %u (expected %u or %u)", pkt[0], PCP_VERS, NATMAP_VERS); } // Called from mDNSCoreReceive with the lock held mDNSexport void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport) { DNSQuestion *qptr; mStatus err = mStatus_NoError; mDNSu8 StdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery; mDNSu8 UpdateR = kDNSFlag0_QR_Response | kDNSFlag0_OP_Update; mDNSu8 QR_OP = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask); mDNSu8 rcode = (mDNSu8)(msg->h.flags.b[1] & kDNSFlag1_RC_Mask); (void)srcport; // Unused debugf("uDNS_ReceiveMsg from %#-15a with " "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes", srcaddr, msg->h.numQuestions, msg->h.numQuestions == 1 ? ", " : "s,", msg->h.numAnswers, msg->h.numAnswers == 1 ? ", " : "s,", msg->h.numAuthorities, msg->h.numAuthorities == 1 ? "y, " : "ies,", msg->h.numAdditionals, msg->h.numAdditionals == 1 ? "" : "s", end - msg->data); #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) && !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (NumUnreachableDNSServers > 0) SymptomReporterDNSServerReachable(m, srcaddr); #endif if (QR_OP == StdR) { //if (srcaddr && recvLLQResponse(m, msg, end, srcaddr, srcport)) return; for (qptr = m->Questions; qptr; qptr = qptr->next) if (msg->h.flags.b[0] & kDNSFlag0_TC && mDNSSameOpaque16(qptr->TargetQID, msg->h.id) && m->timenow - qptr->LastQTime < RESPONSE_WINDOW) { if (!srcaddr) LogMsg("uDNS_ReceiveMsg: TCP DNS response had TC bit set: ignoring"); else { uDNS_RestartQuestionAsTCP(m, qptr, srcaddr, srcport); #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) qptr->metrics.dnsOverTCPState = DNSOverTCP_Truncated; #endif } } } if (QR_OP == UpdateR) { mDNSu32 pktlease = 0; mDNSBool gotlease = GetPktLease(m, msg, end, &pktlease); mDNSu32 lease = gotlease ? pktlease : 60 * 60; // If lease option missing, assume one hour mDNSs32 expire = m->timenow + (mDNSs32)lease * mDNSPlatformOneSecond; mDNSu32 random = mDNSRandom((mDNSs32)lease * mDNSPlatformOneSecond/10); //rcode = kDNSFlag1_RC_ServFail; // Simulate server failure (rcode 2) // Walk through all the records that matches the messageID. There could be multiple // records if we had sent them in a group if (m->CurrentRecord) LogMsg("uDNS_ReceiveMsg ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); m->CurrentRecord = m->ResourceRecords; while (m->CurrentRecord) { AuthRecord *rptr = m->CurrentRecord; m->CurrentRecord = m->CurrentRecord->next; if (AuthRecord_uDNS(rptr) && mDNSSameOpaque16(rptr->updateid, msg->h.id)) { err = checkUpdateResult(m, rptr->resrec.name, rcode, msg, end); if (!err && rptr->uselease && lease) if (rptr->expire - expire >= 0 || rptr->state != regState_UpdatePending) { rptr->expire = expire; rptr->refreshCount = 0; } // We pass the random value to make sure that if we update multiple // records, they all get the same random value hndlRecordUpdateReply(m, rptr, err, random); } } } debugf("Received unexpected response: ID %d matches no active records", mDNSVal16(msg->h.id)); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Query Routines #endif mDNSexport void sendLLQRefresh(mDNS *m, DNSQuestion *q) { mDNSu8 *end; LLQOptData llq; if (q->ReqLease) if ((q->state == LLQ_Established && q->ntries >= kLLQ_MAX_TRIES) || q->expire - m->timenow < 0) { LogMsg("Unable to refresh LLQ %##s (%s) - will retry in %d seconds", q->qname.c, DNSTypeName(q->qtype), LLQ_POLL_INTERVAL / mDNSPlatformOneSecond); StartLLQPolling(m,q); return; } llq.vers = kLLQ_Vers; llq.llqOp = kLLQOp_Refresh; llq.err = q->tcp ? GetLLQEventPort(m, &q->servAddr) : LLQErr_NoError; // If using TCP tell server what UDP port to send notifications to llq.id = q->id; llq.llqlease = q->ReqLease; InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); end = putLLQ(&m->omsg, m->omsg.data, q, &llq); if (!end) { LogMsg("sendLLQRefresh: putLLQ failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } { mStatus err; LogInfo("sendLLQRefresh: using existing UDP session %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); err = mDNSSendDNSMessage(m, &m->omsg, end, mDNSInterface_Any, q->tcp ? q->tcp->sock : mDNSNULL, q->LocalSocket, &q->servAddr, q->servPort, mDNSNULL, mDNSfalse); if (err) { LogMsg("sendLLQRefresh: mDNSSendDNSMessage%s failed: %d", q->tcp ? " (TCP)" : "", err); if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } } } q->ntries++; debugf("sendLLQRefresh ntries %d %##s (%s)", q->ntries, q->qname.c, DNSTypeName(q->qtype)); q->LastQTime = m->timenow; SetNextQueryTime(m, q); } mDNSexport void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo) { DNSQuestion *q = (DNSQuestion *)zoneInfo->ZoneDataContext; mDNS_Lock(m); // If we get here it means that the GetZoneData operation has completed. // We hold on to the zone data if it is AutoTunnel as we use the hostname // in zoneInfo during the TLS connection setup. q->servAddr = zeroAddr; q->servPort = zeroIPPort; if (!err && !mDNSIPPortIsZero(zoneInfo->Port) && !mDNSAddressIsZero(&zoneInfo->Addr) && zoneInfo->Host.c[0]) { q->servAddr = zoneInfo->Addr; q->servPort = zoneInfo->Port; // We don't need the zone data as we use it only for the Host information which we // don't need if we are not going to use TLS connections. if (q->nta) { if (q->nta != zoneInfo) LogMsg("LLQGotZoneData: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); CancelGetZoneData(m, q->nta); q->nta = mDNSNULL; } q->ntries = 0; debugf("LLQGotZoneData %#a:%d", &q->servAddr, mDNSVal16(q->servPort)); startLLQHandshake(m, q); } else { if (q->nta) { if (q->nta != zoneInfo) LogMsg("LLQGotZoneData: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); CancelGetZoneData(m, q->nta); q->nta = mDNSNULL; } StartLLQPolling(m,q); if (err == mStatus_NoSuchNameErr) { // this actually failed, so mark it by setting address to all ones q->servAddr.type = mDNSAddrType_IPv4; q->servAddr.ip.v4 = onesIPv4Addr; } } mDNS_Unlock(m); } #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) mDNSexport void DNSPushNotificationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo) { DNSQuestion *q = (DNSQuestion *)zoneInfo->ZoneDataContext; mDNS_Lock(m); // If we get here it means that the GetZoneData operation has completed. q->servAddr = zeroAddr; q->servPort = zeroIPPort; if (!err && zoneInfo && !mDNSIPPortIsZero(zoneInfo->Port) && zoneInfo->Host.c[0]) { q->state = LLQ_DNSPush_Connecting; LogInfo("DNSPushNotificationGotZoneData %##s%%%d", &zoneInfo->Host, ntohs(zoneInfo->Port.NotAnInteger)); q->dnsPushServer = SubscribeToDNSPushNotificationServer(m, q); if (q->dnsPushServer == mDNSNULL || (q->dnsPushServer->connectState != DNSPushServerConnectionInProgress && q->dnsPushServer->connectState != DNSPushServerConnected && q->dnsPushServer->connectState != DNSPushServerSessionEstablished)) { goto noServer; } } else { noServer: q->state = LLQ_InitialRequest; startLLQHandshake(m,q); } mDNS_Unlock(m); } #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Dynamic Updates #endif // Called in normal callback context (i.e. mDNS_busy and mDNS_reentrancy are both 1) mDNSexport void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData) { AuthRecord *newRR; AuthRecord *ptr; int c1, c2; if (!zoneData) { LogMsg("ERROR: RecordRegistrationGotZoneData invoked with NULL result and no error"); return; } newRR = (AuthRecord*)zoneData->ZoneDataContext; if (newRR->nta != zoneData) LogMsg("RecordRegistrationGotZoneData: nta (%p) != zoneData (%p) %##s (%s)", newRR->nta, zoneData, newRR->resrec.name->c, DNSTypeName(newRR->resrec.rrtype)); if (m->mDNS_busy != m->mDNS_reentrancy) LogMsg("RecordRegistrationGotZoneData: mDNS_busy (%ld) != mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); // make sure record is still in list (!!!) for (ptr = m->ResourceRecords; ptr; ptr = ptr->next) if (ptr == newRR) break; if (!ptr) { LogMsg("RecordRegistrationGotZoneData - RR no longer in list. Discarding."); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } // check error/result if (err) { if (err != mStatus_NoSuchNameErr) LogMsg("RecordRegistrationGotZoneData: error %d", err); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } if (newRR->resrec.rrclass != zoneData->ZoneClass) { LogMsg("ERROR: New resource record's class (%d) does not match zone class (%d)", newRR->resrec.rrclass, zoneData->ZoneClass); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } // Don't try to do updates to the root name server. // We might be tempted also to block updates to any single-label name server (e.g. com, edu, net, etc.) but some // organizations use their own private pseudo-TLD, like ".home", etc, and we don't want to block that. if (zoneData->ZoneName.c[0] == 0) { LogInfo("RecordRegistrationGotZoneData: No name server found claiming responsibility for \"%##s\"!", newRR->resrec.name->c); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } // Store discovered zone data c1 = CountLabels(newRR->resrec.name); c2 = CountLabels(&zoneData->ZoneName); if (c2 > c1) { LogMsg("RecordRegistrationGotZoneData: Zone \"%##s\" is longer than \"%##s\"", zoneData->ZoneName.c, newRR->resrec.name->c); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } newRR->zone = SkipLeadingLabels(newRR->resrec.name, c1-c2); if (!SameDomainName(newRR->zone, &zoneData->ZoneName)) { LogMsg("RecordRegistrationGotZoneData: Zone \"%##s\" does not match \"%##s\" for \"%##s\"", newRR->zone->c, zoneData->ZoneName.c, newRR->resrec.name->c); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } if (mDNSIPPortIsZero(zoneData->Port) || mDNSAddressIsZero(&zoneData->Addr) || !zoneData->Host.c[0]) { LogInfo("RecordRegistrationGotZoneData: No _dns-update._udp service found for \"%##s\"!", newRR->resrec.name->c); CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } newRR->Private = zoneData->ZonePrivate; debugf("RecordRegistrationGotZoneData: Set zone information for %##s %##s to %#a:%d", newRR->resrec.name->c, zoneData->ZoneName.c, &zoneData->Addr, mDNSVal16(zoneData->Port)); // If we are deregistering, uDNS_DeregisterRecord will do that as it has the zone data now. if (newRR->state == regState_DeregPending) { mDNS_Lock(m); uDNS_DeregisterRecord(m, newRR); mDNS_Unlock(m); return; } if (newRR->resrec.rrtype == kDNSType_SRV) { const domainname *target; // Reevaluate the target always as NAT/Target could have changed while // we were fetching zone data. mDNS_Lock(m); target = GetServiceTarget(m, newRR); mDNS_Unlock(m); if (!target || target->c[0] == 0) { domainname *t = GetRRDomainNameTarget(&newRR->resrec); LogInfo("RecordRegistrationGotZoneData - no target for %##s", newRR->resrec.name->c); if (t) t->c[0] = 0; newRR->resrec.rdlength = newRR->resrec.rdestimate = 0; newRR->state = regState_NoTarget; CancelGetZoneData(m, newRR->nta); newRR->nta = mDNSNULL; return; } } // If we have non-zero service port (always?) // and a private address, and update server is non-private // and this service is AutoTarget // then initiate a NAT mapping request. On completion it will do SendRecordRegistration() for us if (newRR->resrec.rrtype == kDNSType_SRV && !mDNSIPPortIsZero(newRR->resrec.rdata->u.srv.port) && mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) && newRR->nta && !mDNSAddrIsRFC1918(&newRR->nta->Addr) && newRR->AutoTarget == Target_AutoHostAndNATMAP) { // During network transitions, we are called multiple times in different states. Setup NAT // state just once for this record. if (!newRR->NATinfo.clientContext) { LogInfo("RecordRegistrationGotZoneData StartRecordNatMap %s", ARDisplayString(m, newRR)); newRR->state = regState_NATMap; StartRecordNatMap(m, newRR); return; } else LogInfo("RecordRegistrationGotZoneData: StartRecordNatMap for %s, state %d, context %p", ARDisplayString(m, newRR), newRR->state, newRR->NATinfo.clientContext); } mDNS_Lock(m); // We want IsRecordMergeable to check whether it is a record whose update can be // sent with others. We set the time before we call IsRecordMergeable, so that // it does not fail this record based on time. We are interested in other checks // at this time. If a previous update resulted in error, then don't reset the // interval. Preserve the back-off so that we don't keep retrying aggressively. if (newRR->updateError == mStatus_NoError) { newRR->ThisAPInterval = INIT_RECORD_REG_INTERVAL; newRR->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; } if (IsRecordMergeable(m, newRR, m->timenow + MERGE_DELAY_TIME)) { // Delay the record registration by MERGE_DELAY_TIME so that we can merge them // into one update LogInfo("RecordRegistrationGotZoneData: Delayed registration for %s", ARDisplayString(m, newRR)); newRR->LastAPTime += MERGE_DELAY_TIME; } mDNS_Unlock(m); } mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr) { mDNSu8 *ptr = m->omsg.data; mDNSu8 *limit; DomainAuthInfo *AuthInfo; mDNS_CheckLock(m); if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) { LogMsg("SendRecordDeRegistration: No zone info for Resource record %s RecordType %d", ARDisplayString(m, rr), rr->resrec.RecordType); return; } limit = ptr + AbsoluteMaxDNSMessageData; AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); limit -= RRAdditionalSize(AuthInfo); rr->updateid = mDNS_NewMessageID(m); InitializeDNSMessage(&m->omsg.h, rr->updateid, UpdateReqFlags); // set zone ptr = putZone(&m->omsg, ptr, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); if (!ptr) goto exit; ptr = BuildUpdateMessage(m, ptr, rr, limit); if (!ptr) goto exit; if (rr->Private) { LogInfo("SendRecordDeregistration TCP %p %s", rr->tcp, ARDisplayString(m, rr)); if (rr->tcp) LogInfo("SendRecordDeregistration: Disposing existing TCP connection for %s", ARDisplayString(m, rr)); if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } if (!rr->nta) { LogMsg("SendRecordDeregistration:Private:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } rr->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &rr->nta->Addr, rr->nta->Port, &rr->nta->Host, mDNSNULL, rr); } else { mStatus err; LogInfo("SendRecordDeregistration UDP %s", ARDisplayString(m, rr)); if (!rr->nta) { LogMsg("SendRecordDeregistration:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, mDNSNULL, &rr->nta->Addr, rr->nta->Port, GetAuthInfoForName_internal(m, rr->resrec.name), mDNSfalse); if (err) debugf("ERROR: SendRecordDeregistration - mDNSSendDNSMessage - %d", err); //if (rr->state == regState_DeregPending) CompleteDeregistration(m, rr); // Don't touch rr after this } SetRecordRetry(m, rr, 0); return; exit: LogMsg("SendRecordDeregistration: Error formatting message for %s", ARDisplayString(m, rr)); } mDNSexport mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr) { DomainAuthInfo *info; LogInfo("uDNS_DeregisterRecord: Resource Record %s, state %d", ARDisplayString(m, rr), rr->state); switch (rr->state) { case regState_Refresh: case regState_Pending: case regState_UpdatePending: case regState_Registered: break; case regState_DeregPending: break; case regState_NATError: case regState_NATMap: // A record could be in NoTarget to start with if the corresponding SRV record could not find a target. // It is also possible to reenter the NoTarget state when we move to a network with a NAT that has // no {PCP, NAT-PMP, UPnP/IGD} support. In that case before we entered NoTarget, we already deregistered with // the server. case regState_NoTarget: case regState_Unregistered: case regState_Zero: default: LogInfo("uDNS_DeregisterRecord: State %d for %##s type %s", rr->state, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); // This function may be called during sleep when there are no sleep proxy servers if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) CompleteDeregistration(m, rr); return mStatus_NoError; } // if unsent rdata is queued, free it. // // The data may be queued in QueuedRData or InFlightRData. // // 1) If the record is in Registered state, we store it in InFlightRData and copy the same in "rdata" // *just* before sending the update to the server. Till we get the response, InFlightRData and "rdata" // in the resource record are same. We don't want to free in that case. It will be freed when "rdata" // is freed. If they are not same, the update has not been sent and we should free it here. // // 2) If the record is in UpdatePending state, we queue the update in QueuedRData. When the previous update // comes back from the server, we copy it from QueuedRData to InFlightRData and repeat (1). This implies // that QueuedRData can never be same as "rdata" in the resource record. As long as we have something // left in QueuedRData, we should free it here. if (rr->InFlightRData && rr->UpdateCallback) { if (rr->InFlightRData != rr->resrec.rdata) { LogInfo("uDNS_DeregisterRecord: Freeing InFlightRData for %s", ARDisplayString(m, rr)); rr->UpdateCallback(m, rr, rr->InFlightRData, rr->InFlightRDLen); rr->InFlightRData = mDNSNULL; } else LogInfo("uDNS_DeregisterRecord: InFlightRData same as rdata for %s", ARDisplayString(m, rr)); } if (rr->QueuedRData && rr->UpdateCallback) { if (rr->QueuedRData == rr->resrec.rdata) LogMsg("uDNS_DeregisterRecord: ERROR!! QueuedRData same as rdata for %s", ARDisplayString(m, rr)); else { LogInfo("uDNS_DeregisterRecord: Freeing QueuedRData for %s", ARDisplayString(m, rr)); rr->UpdateCallback(m, rr, rr->QueuedRData, rr->QueuedRDLen); rr->QueuedRData = mDNSNULL; } } // If a current group registration is pending, we can't send this deregisration till that registration // has reached the server i.e., the ordering is important. Previously, if we did not send this // registration in a group, then the previous connection will be torn down as part of sending the // deregistration. If we send this in a group, we need to locate the resource record that was used // to send this registration and terminate that connection. This means all the updates on that might // be lost (assuming the response is not waiting for us at the socket) and the retry will send the // update again sometime in the near future. // // NOTE: SSL handshake failures normally free the TCP connection immediately. Hence, you may not // find the TCP below there. This case can happen only when tcp is trying to actively retransmit // the request or SSL negotiation taking time i.e resource record is actively trying to get the // message to the server. During that time a deregister has to happen. if (!mDNSOpaque16IsZero(rr->updateid)) { AuthRecord *anchorRR; mDNSBool found = mDNSfalse; for (anchorRR = m->ResourceRecords; anchorRR; anchorRR = anchorRR->next) { if (AuthRecord_uDNS(rr) && mDNSSameOpaque16(anchorRR->updateid, rr->updateid) && anchorRR->tcp) { LogInfo("uDNS_DeregisterRecord: Found Anchor RR %s terminated", ARDisplayString(m, anchorRR)); if (found) LogMsg("uDNS_DeregisterRecord: ERROR: Another anchorRR %s found", ARDisplayString(m, anchorRR)); DisposeTCPConn(anchorRR->tcp); anchorRR->tcp = mDNSNULL; found = mDNStrue; } } if (!found) LogInfo("uDNSDeregisterRecord: Cannot find the anchor Resource Record for %s, not an error", ARDisplayString(m, rr)); } // Retry logic for deregistration should be no different from sending registration the first time. // Currently ThisAPInterval most likely is set to the refresh interval rr->state = regState_DeregPending; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; info = GetAuthInfoForName_internal(m, rr->resrec.name); if (IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) { // Delay the record deregistration by MERGE_DELAY_TIME so that we can merge them // into one update. If the domain is being deleted, delay by 2 * MERGE_DELAY_TIME // so that we can merge all the AutoTunnel records and the service records in // one update (they get deregistered a little apart) if (info && info->deltime) rr->LastAPTime += (2 * MERGE_DELAY_TIME); else rr->LastAPTime += MERGE_DELAY_TIME; } // IsRecordMergeable could have returned false for several reasons e.g., DontMerge is set or // no zone information. Most likely it is the latter, CheckRecordUpdates will fetch the zone // data when it encounters this record. if (m->NextuDNSEvent - (rr->LastAPTime + rr->ThisAPInterval) >= 0) m->NextuDNSEvent = (rr->LastAPTime + rr->ThisAPInterval); return mStatus_NoError; } mDNSexport mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr) { LogInfo("uDNS_UpdateRecord: Resource Record %##s, state %d", rr->resrec.name->c, rr->state); switch(rr->state) { case regState_DeregPending: case regState_Unregistered: // not actively registered goto unreg_error; case regState_NATMap: case regState_NoTarget: // change rdata directly since it hasn't been sent yet if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->resrec.rdata, rr->resrec.rdlength); SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength); rr->NewRData = mDNSNULL; return mStatus_NoError; case regState_Pending: case regState_Refresh: case regState_UpdatePending: // registration in-flight. queue rdata and return if (rr->QueuedRData && rr->UpdateCallback) // if unsent rdata is already queued, free it before we replace it rr->UpdateCallback(m, rr, rr->QueuedRData, rr->QueuedRDLen); rr->QueuedRData = rr->NewRData; rr->QueuedRDLen = rr->newrdlength; rr->NewRData = mDNSNULL; return mStatus_NoError; case regState_Registered: rr->OrigRData = rr->resrec.rdata; rr->OrigRDLen = rr->resrec.rdlength; rr->InFlightRData = rr->NewRData; rr->InFlightRDLen = rr->newrdlength; rr->NewRData = mDNSNULL; rr->state = regState_UpdatePending; rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; SetNextuDNSEvent(m, rr); return mStatus_NoError; case regState_NATError: LogMsg("ERROR: uDNS_UpdateRecord called for record %##s with bad state regState_NATError", rr->resrec.name->c); return mStatus_UnknownErr; // states for service records only default: LogMsg("uDNS_UpdateRecord: Unknown state %d for %##s", rr->state, rr->resrec.name->c); } unreg_error: LogMsg("uDNS_UpdateRecord: Requested update of record %##s type %d, in erroneous state %d", rr->resrec.name->c, rr->resrec.rrtype, rr->state); return mStatus_Invalid; } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Periodic Execution Routines #endif mDNSlocal void uDNS_HandleLLQState(mDNS *const m, DNSQuestion *q) { LogMsg("->uDNS_HandleLLQState: %##s %d", &q->qname, q->state); switch(q->state) { case LLQ_Init: // If DNS Push isn't supported, LLQ_Init falls through to LLQ_InitialRequest. #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) // First attempt to use DNS Push Notification. DiscoverDNSPushNotificationServer(m, q); break; case LLQ_DNSPush_ServerDiscovery: case LLQ_DNSPush_Connecting: case LLQ_DNSPush_Established: // Sanity check the server state to see if it matches. If we find that we aren't connected, when // we think we should be, change our state. if (q->dnsPushServer == NULL) { q->state = LLQ_Init; q->ThisQInterval = 0; q->LastQTime = m->timenow; SetNextQueryTime(m, q); } else { switch(q->dnsPushServer->connectState) { case DNSPushServerDisconnected: case DNSPushServerConnectFailed: case DNSPushServerNoDNSPush: LogMsg("uDNS_HandleLLQState: %##s, server state %d doesn't match question state %d", &q->dnsPushServer->serverName, q->state, q->dnsPushServer->connectState); q->state = LLQ_Poll; q->ThisQInterval = (mDNSPlatformOneSecond * 5); q->LastQTime = m->timenow; SetNextQueryTime(m, q); break; case DNSPushServerSessionEstablished: LogMsg("uDNS_HandleLLQState: %##s, server connection established but question state is %d", &q->dnsPushServer->serverName, q->state); q->state = LLQ_DNSPush_Established; q->ThisQInterval = 0; q->LastQTime = m->timenow; SetNextQueryTime(m, q); break; case DNSPushServerConnectionInProgress: case DNSPushServerConnected: break; } } break; #else // Silence warnings; these are never reached without DNS Push case LLQ_DNSPush_ServerDiscovery: case LLQ_DNSPush_Connecting: case LLQ_DNSPush_Established: #endif // MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) case LLQ_InitialRequest: startLLQHandshake(m, q); break; case LLQ_SecondaryRequest: sendChallengeResponse(m, q, mDNSNULL); break; case LLQ_Established: sendLLQRefresh(m, q); break; case LLQ_Poll: break; // Do nothing (handled below) } LogMsg("<-uDNS_HandleLLQState: %##s %d %d", &q->qname, q->state); } // The question to be checked is not passed in as an explicit parameter; // instead it is implicit that the question to be checked is m->CurrentQuestion. mDNSlocal void uDNS_CheckCurrentQuestion(mDNS *const m) { DNSQuestion *q = m->CurrentQuestion; if (m->timenow - NextQSendTime(q) < 0) return; if (q->LongLived) { uDNS_HandleLLQState(m,q); } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) Querier_HandleUnicastQuestion(q); #else // We repeat the check above (rather than just making this the "else" case) because startLLQHandshake can change q->state to LLQ_Poll if (!(q->LongLived && q->state != LLQ_Poll)) { if (q->unansweredQueries >= MAX_UCAST_UNANSWERED_QUERIES) { DNSServer *orig = q->qDNSServer; if (orig) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_CheckCurrentQuestion: Sent %d unanswered queries for " PRI_DM_NAME " (" PUB_S ") to " PRI_IP_ADDR ":%d (" PRI_DM_NAME ")", q->request_id, mDNSVal16(q->TargetQID), q->unansweredQueries, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), &orig->addr, mDNSVal16(orig->port), DM_NAME_PARAM(&orig->domain)); } #if MDNSRESPONDER_SUPPORTS(APPLE, SYMPTOMS) SymptomReporterDNSServerUnreachable(orig); #endif PenalizeDNSServer(m, q, zeroID); q->noServerResponse = 1; } // There are two cases here. // // 1. We have only one DNS server for this question. It is not responding even after we sent MAX_UCAST_UNANSWERED_QUERIES. // In that case, we need to keep retrying till we get a response. But we need to backoff as we retry. We set // noServerResponse in the block above and below we do not touch the question interval. When we come here, we // already waited for the response. We need to send another query right at this moment. We do that below by // reinitializing dns servers and reissuing the query. // // 2. We have more than one DNS server. If at least one server did not respond, we would have set noServerResponse // either now (the last server in the list) or before (non-last server in the list). In either case, if we have // reached the end of DNS server list, we need to try again from the beginning. Ideally we should try just the // servers that did not respond, but for simplicity we try all the servers. Once we reached the end of list, we // set triedAllServersOnce so that we don't try all the servers aggressively. See PenalizeDNSServer. if (!q->qDNSServer && q->noServerResponse) { DNSServer *new; DNSQuestion *qptr; q->triedAllServersOnce = mDNStrue; // Re-initialize all DNS servers for this question. If we have a DNSServer, DNSServerChangeForQuestion will // handle all the work including setting the new DNS server. SetValidDNSServers(m, q); new = GetServerForQuestion(m, q); if (new) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_checkCurrentQuestion: Retrying question %p " PRI_DM_NAME " (" PUB_S ") DNS Server " PRI_IP_ADDR ":%d ThisQInterval %d", q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), new ? &new->addr : mDNSNULL, mDNSVal16(new ? new->port : zeroIPPort), q->ThisQInterval); DNSServerChangeForQuestion(m, q, new); } for (qptr = q->next ; qptr; qptr = qptr->next) if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = q->qDNSServer; } } if (q->qDNSServer) { mDNSu8 *end; mStatus err = mStatus_NoError; mDNSOpaque16 HeaderFlags = uQueryFlags; InitializeDNSMessage(&m->omsg.h, q->TargetQID, HeaderFlags); end = putQuestion(&m->omsg, m->omsg.data, m->omsg.data + AbsoluteMaxDNSMessageData, &q->qname, q->qtype, q->qclass); if (end > m->omsg.data) { debugf("uDNS_CheckCurrentQuestion sending %p %##s (%s) %#a:%d UnansweredQueries %d", q, q->qname.c, DNSTypeName(q->qtype), q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort), q->unansweredQueries); #if APPLE_OSX_mDNSResponder // When a DNS proxy network extension initiates the close of a UDP flow (this usually happens when a DNS // proxy gets disabled or crashes), mDNSResponder's corresponding UDP socket will be marked with the // SS_CANTRCVMORE state flag. Reading from such a socket is no longer possible, so close the current // socket pair so that we can create a new pair. if (q->LocalSocket && mDNSPlatformUDPSocketEncounteredEOF(q->LocalSocket)) { mDNSPlatformUDPClose(q->LocalSocket); q->LocalSocket = mDNSNULL; } #endif if (!q->LocalSocket) { q->LocalSocket = mDNSPlatformUDPSocket(zeroIPPort); if (q->LocalSocket) { mDNSPlatformSetSocktOpt(q->LocalSocket, mDNSTransport_UDP, mDNSAddrType_IPv4, q); mDNSPlatformSetSocktOpt(q->LocalSocket, mDNSTransport_UDP, mDNSAddrType_IPv6, q); } } if (!q->LocalSocket) err = mStatus_NoMemoryErr; // If failed to make socket (should be very rare), we'll try again next time else { err = mDNSSendDNSMessage(m, &m->omsg, end, q->qDNSServer->interface, mDNSNULL, q->LocalSocket, &q->qDNSServer->addr, q->qDNSServer->port, mDNSNULL, q->UseBackgroundTraffic); #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) if (!err) { MetricsUpdateDNSQuerySize((mDNSu32)(end - (mDNSu8 *)&m->omsg)); if (q->metrics.answered) { q->metrics.querySendCount = 0; q->metrics.answered = mDNSfalse; } if (q->metrics.querySendCount++ == 0) { q->metrics.firstQueryTime = NonZeroTime(m->timenow); } } #endif } } if (err == mStatus_HostUnreachErr) { DNSServer *newServer; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_CheckCurrentQuestion: host unreachable error for DNS server " PRI_IP_ADDR " for question [%p] " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), &q->qDNSServer->addr, q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); if (!StrictUnicastOrdering) { q->qDNSServer->penaltyTime = NonZeroTime(m->timenow + DNSSERVER_PENALTY_TIME); } newServer = GetServerForQuestion(m, q); if (!newServer) { q->triedAllServersOnce = mDNStrue; SetValidDNSServers(m, q); newServer = GetServerForQuestion(m, q); } if (newServer) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_checkCurrentQuestion: Retrying question %p " PRI_DM_NAME " (" PUB_S ") DNS Server " PRI_IP_ADDR ":%u ThisQInterval %d", q->request_id, mDNSVal16(q->TargetQID), q, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), newServer ? &newServer->addr : mDNSNULL, mDNSVal16(newServer ? newServer->port : zeroIPPort), q->ThisQInterval); DNSServerChangeForQuestion(m, q, newServer); } if (q->triedAllServersOnce) { q->LastQTime = m->timenow; } else { q->ThisQInterval = InitialQuestionInterval; q->LastQTime = m->timenow - q->ThisQInterval; } q->unansweredQueries = 0; } else { if (err != mStatus_TransientErr) // if it is not a transient error backoff and DO NOT flood queries unnecessarily { // If all DNS Servers are not responding, then we back-off using the multiplier UDNSBackOffMultiplier(*2). // Only increase interval if send succeeded q->ThisQInterval = q->ThisQInterval * UDNSBackOffMultiplier; if ((q->ThisQInterval > 0) && (q->ThisQInterval < MinQuestionInterval)) // We do not want to retx within 1 sec q->ThisQInterval = MinQuestionInterval; q->unansweredQueries++; if (q->ThisQInterval > MAX_UCAST_POLL_INTERVAL) q->ThisQInterval = MAX_UCAST_POLL_INTERVAL; if (q->qDNSServer->isCell) { // We don't want to retransmit too soon. Schedule our first retransmisson at // MIN_UCAST_RETRANS_TIMEOUT seconds. if (q->ThisQInterval < MIN_UCAST_RETRANS_TIMEOUT) q->ThisQInterval = MIN_UCAST_RETRANS_TIMEOUT; } debugf("uDNS_CheckCurrentQuestion: Increased ThisQInterval to %d for %##s (%s), cell %d", q->ThisQInterval, q->qname.c, DNSTypeName(q->qtype), q->qDNSServer->isCell); } q->LastQTime = m->timenow; } SetNextQueryTime(m, q); } else { // If we have no server for this query, or the only server is a disabled one, then we deliver // a transient failure indication to the client. This is important for things like iPhone // where we want to return timely feedback to the user when no network is available. // After calling MakeNegativeCacheRecord() we store the resulting record in the // cache so that it will be visible to other clients asking the same question. // (When we have a group of identical questions, only the active representative of the group gets // passed to uDNS_CheckCurrentQuestion -- we only want one set of query packets hitting the wire -- // but we want *all* of the questions to get answer callbacks.) CacheRecord *cr; const mDNSu32 slot = HashSlotFromNameHash(q->qnamehash); CacheGroup *const cg = CacheGroupForName(m, q->qnamehash, &q->qname); if (!q->qDNSServer) { if (!mDNSOpaque128IsZero(&q->validDNSServers)) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u->Q%u] uDNS_CheckCurrentQuestion: ERROR!!: valid DNSServer bits not zero 0x%x, 0x%x 0x%x 0x%x for question " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), q->validDNSServers.l[3], q->validDNSServers.l[2], q->validDNSServers.l[1], q->validDNSServers.l[0], DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); // If we reached the end of list while picking DNS servers, then we don't want to deactivate the // question. Try after 60 seconds. We find this by looking for valid DNSServers for this question, // if we find any, then we must have tried them before we came here. This avoids maintaining // another state variable to see if we had valid DNS servers for this question. SetValidDNSServers(m, q); if (mDNSOpaque128IsZero(&q->validDNSServers)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_CheckCurrentQuestion: no DNS server for " PRI_DM_NAME " (" PUB_S ")", q->request_id, mDNSVal16(q->TargetQID), DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype)); q->ThisQInterval = 0; } else { DNSQuestion *qptr; // Pretend that we sent this question. As this is an ActiveQuestion, the NextScheduledQuery should // be set properly. Also, we need to properly backoff in cases where we don't set the question to // MaxQuestionInterval when we answer the question e.g., LongLived, we need to keep backing off q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; q->LastQTime = m->timenow; SetNextQueryTime(m, q); // Pick a new DNS server now. Otherwise, when the cache is 80% of its expiry, we will try // to send a query and come back to the same place here and log the above message. q->qDNSServer = GetServerForQuestion(m, q); for (qptr = q->next ; qptr; qptr = qptr->next) if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = q->qDNSServer; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_checkCurrentQuestion: Tried all DNS servers, retry question %p SuppressUnusable %d " PRI_DM_NAME " (" PUB_S ") with DNS Server " PRI_IP_ADDR ":%d after 60 seconds, ThisQInterval %d", q->request_id, mDNSVal16(q->TargetQID), q, q->SuppressUnusable, DM_NAME_PARAM(&q->qname), DNSTypeName(q->qtype), q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort), q->ThisQInterval); } } else { q->ThisQInterval = 0; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_CheckCurrentQuestion DNS server " PRI_IP_ADDR ":%d for " PRI_DM_NAME " is disabled", q->request_id, mDNSVal16(q->TargetQID), &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), DM_NAME_PARAM(&q->qname)); } if (cg) { for (cr = cg->members; cr; cr=cr->next) { if (SameNameCacheRecordAnswersQuestion(cr, q)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] uDNS_CheckCurrentQuestion: Purged resourcerecord " PRI_S, q->request_id, mDNSVal16(q->TargetQID), CRDisplayString(m, cr)); mDNS_PurgeCacheResourceRecord(m, cr); } } } // For some of the WAB queries that we generate form within the mDNSResponder, most of the home routers // don't understand and return ServFail/NXDomain. In those cases, we don't want to try too often. We try // every fifteen minutes in that case MakeNegativeCacheRecord(m, &m->rec.r, &q->qname, q->qnamehash, q->qtype, q->qclass, (DomainEnumQuery(&q->qname) ? 60 * 15 : 60), mDNSInterface_Any, q->qDNSServer); q->unansweredQueries = 0; if (!mDNSOpaque16IsZero(q->responseFlags)) m->rec.r.responseFlags = q->responseFlags; // We're already using the m->CurrentQuestion pointer, so CacheRecordAdd can't use it to walk the question list. // To solve this problem we set cr->DelayDelivery to a nonzero value (which happens to be 'now') so that we // momentarily defer generating answer callbacks until mDNS_Execute time. CreateNewCacheEntry(m, slot, cg, NonZeroTime(m->timenow), mDNStrue, mDNSNULL); ScheduleNextCacheCheckTime(m, slot, NonZeroTime(m->timenow)); m->rec.r.responseFlags = zeroID; m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it // MUST NOT touch m->CurrentQuestion (or q) after this -- client callback could have deleted it } } #endif // MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) } mDNSexport void CheckNATMappings(mDNS *m) { mDNSBool rfc1918 = mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4); mDNSBool HaveRoutable = !rfc1918 && !mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4); m->NextScheduledNATOp = m->timenow + FutureTime; if (HaveRoutable) m->ExtAddress = m->AdvertisedV4.ip.v4; if (m->NATTraversals && rfc1918) // Do we need to open a socket to receive multicast announcements from router? { if (m->NATMcastRecvskt == mDNSNULL) // If we are behind a NAT and the socket hasn't been opened yet, open it { // we need to log a message if we can't get our socket, but only the first time (after success) static mDNSBool needLog = mDNStrue; m->NATMcastRecvskt = mDNSPlatformUDPSocket(NATPMPAnnouncementPort); if (!m->NATMcastRecvskt) { if (needLog) { LogMsg("CheckNATMappings: Failed to allocate port 5350 UDP multicast socket for PCP & NAT-PMP announcements"); needLog = mDNSfalse; } } else needLog = mDNStrue; } } else // else, we don't want to listen for announcements, so close them if they're open { if (m->NATMcastRecvskt) { mDNSPlatformUDPClose(m->NATMcastRecvskt); m->NATMcastRecvskt = mDNSNULL; } if (m->SSDPSocket) { debugf("CheckNATMappings destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } } uDNS_RequestAddress(m); if (m->CurrentNATTraversal) LogMsg("WARNING m->CurrentNATTraversal already in use"); m->CurrentNATTraversal = m->NATTraversals; while (m->CurrentNATTraversal) { NATTraversalInfo *cur = m->CurrentNATTraversal; mDNSv4Addr EffectiveAddress = HaveRoutable ? m->AdvertisedV4.ip.v4 : cur->NewAddress; m->CurrentNATTraversal = m->CurrentNATTraversal->next; if (HaveRoutable) // If not RFC 1918 address, our own address and port are effectively our external address and port { cur->ExpiryTime = 0; cur->NewResult = mStatus_NoError; } else // Check if it's time to send port mapping packet(s) { if (m->timenow - cur->retryPortMap >= 0) // Time to send a mapping request for this packet { if (cur->ExpiryTime && cur->ExpiryTime - m->timenow < 0) // Mapping has expired { cur->ExpiryTime = 0; cur->retryInterval = NATMAP_INIT_RETRY; } uDNS_SendNATMsg(m, cur, mDNStrue, mDNSfalse); // Will also do UPnP discovery for us, if necessary if (cur->ExpiryTime) // If have active mapping then set next renewal time halfway to expiry NATSetNextRenewalTime(m, cur); else // else no mapping; use exponential backoff sequence { if (cur->retryInterval < NATMAP_INIT_RETRY ) cur->retryInterval = NATMAP_INIT_RETRY; else if (cur->retryInterval < NATMAP_MAX_RETRY_INTERVAL / 2) cur->retryInterval *= 2; else cur->retryInterval = NATMAP_MAX_RETRY_INTERVAL; cur->retryPortMap = m->timenow + cur->retryInterval; } } if (m->NextScheduledNATOp - cur->retryPortMap > 0) { m->NextScheduledNATOp = cur->retryPortMap; } } // Notify the client if necessary. We invoke the callback if: // (1) We have an effective address, // or we've tried and failed a couple of times to discover it // AND // (2) the client requested the address only, // or the client won't need a mapping because we have a routable address, // or the client has an expiry time and therefore a successful mapping, // or we've tried and failed a couple of times (see "Time line" below) // AND // (3) we have new data to give the client that's changed since the last callback // // Time line is: Send, Wait 500ms, Send, Wait 1sec, Send, Wait 2sec, Send // At this point we've sent three requests without an answer, we've just sent our fourth request, // retryInterval is now 4 seconds, which is greater than NATMAP_INIT_RETRY * 8 (2 seconds), // so we return an error result to the caller. if (!mDNSIPv4AddressIsZero(EffectiveAddress) || cur->retryInterval > NATMAP_INIT_RETRY * 8) { const mStatus EffectiveResult = cur->NewResult ? cur->NewResult : mDNSv4AddrIsRFC1918(&EffectiveAddress) ? mStatus_DoubleNAT : mStatus_NoError; const mDNSIPPort ExternalPort = HaveRoutable ? cur->IntPort : !mDNSIPv4AddressIsZero(EffectiveAddress) && cur->ExpiryTime ? cur->RequestedPort : zeroIPPort; if (!cur->Protocol || HaveRoutable || cur->ExpiryTime || cur->retryInterval > NATMAP_INIT_RETRY * 8) { if (!mDNSSameIPv4Address(cur->ExternalAddress, EffectiveAddress) || !mDNSSameIPPort (cur->ExternalPort, ExternalPort) || cur->Result != EffectiveResult) { //LogMsg("NAT callback %d %d %d", cur->Protocol, cur->ExpiryTime, cur->retryInterval); if (cur->Protocol && mDNSIPPortIsZero(ExternalPort) && !mDNSIPv4AddressIsZero(m->Router.ip.v4)) { if (!EffectiveResult) LogInfo("CheckNATMapping: Failed to obtain NAT port mapping %p from router %#a external address %.4a internal port %5d interval %d error %d", cur, &m->Router, &EffectiveAddress, mDNSVal16(cur->IntPort), cur->retryInterval, EffectiveResult); else LogMsg("CheckNATMapping: Failed to obtain NAT port mapping %p from router %#a external address %.4a internal port %5d interval %d error %d", cur, &m->Router, &EffectiveAddress, mDNSVal16(cur->IntPort), cur->retryInterval, EffectiveResult); } cur->ExternalAddress = EffectiveAddress; cur->ExternalPort = ExternalPort; cur->Lifetime = cur->ExpiryTime && !mDNSIPPortIsZero(ExternalPort) ? (cur->ExpiryTime - m->timenow + mDNSPlatformOneSecond/2) / mDNSPlatformOneSecond : 0; cur->Result = EffectiveResult; mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback if (cur->clientCallback) cur->clientCallback(m, cur); mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again // MUST NOT touch cur after invoking the callback } } } } } mDNSlocal mDNSs32 CheckRecordUpdates(mDNS *m) { AuthRecord *rr; mDNSs32 nextevent = m->timenow + FutureTime; CheckGroupRecordUpdates(m); for (rr = m->ResourceRecords; rr; rr = rr->next) { if (!AuthRecord_uDNS(rr)) continue; if (rr->state == regState_NoTarget) {debugf("CheckRecordUpdates: Record %##s in NoTarget", rr->resrec.name->c); continue;} // While we are waiting for the port mapping, we have nothing to do. The port mapping callback // will take care of this if (rr->state == regState_NATMap) {debugf("CheckRecordUpdates: Record %##s in NATMap", rr->resrec.name->c); continue;} if (rr->state == regState_Pending || rr->state == regState_DeregPending || rr->state == regState_UpdatePending || rr->state == regState_Refresh || rr->state == regState_Registered) { if (rr->LastAPTime + rr->ThisAPInterval - m->timenow <= 0) { if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) { // Zero out the updateid so that if we have a pending response from the server, it won't // be accepted as a valid response. If we accept the response, we might free the new "nta" if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); } rr->nta = StartGetZoneData(m, rr->resrec.name, ZoneServiceUpdate, RecordRegistrationGotZoneData, rr); // We have just started the GetZoneData. We need to wait for it to finish. SetRecordRetry here // schedules the update timer to fire in the future. // // There are three cases. // // 1) When the updates are sent the first time, the first retry is intended to be at three seconds // in the future. But by calling SetRecordRetry here we set it to nine seconds. But it does not // matter because when the answer comes back, RecordRegistrationGotZoneData resets the interval // back to INIT_RECORD_REG_INTERVAL. This also gives enough time for the query. // // 2) In the case of update errors (updateError), this causes further backoff as // RecordRegistrationGotZoneData does not reset the timer. This is intentional as in the case of // errors, we don't want to update aggressively. // // 3) We might be refreshing the update. This is very similar to case (1). RecordRegistrationGotZoneData // resets it back to INIT_RECORD_REG_INTERVAL. // SetRecordRetry(m, rr, 0); } else if (rr->state == regState_DeregPending) SendRecordDeregistration(m, rr); else SendRecordRegistration(m, rr); } } if (nextevent - (rr->LastAPTime + rr->ThisAPInterval) > 0) nextevent = (rr->LastAPTime + rr->ThisAPInterval); } return nextevent; } mDNSexport void uDNS_Tasks(mDNS *const m) { mDNSs32 nexte; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) DNSServer *d; #endif m->NextuDNSEvent = m->timenow + FutureTime; nexte = CheckRecordUpdates(m); if (m->NextuDNSEvent - nexte > 0) m->NextuDNSEvent = nexte; #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) for (d = m->DNSServers; d; d=d->next) if (d->penaltyTime) { if (m->timenow - d->penaltyTime >= 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "DNS server " PRI_IP_ADDR ":%d out of penalty box", &d->addr, mDNSVal16(d->port)); d->penaltyTime = 0; } else if (m->NextuDNSEvent - d->penaltyTime > 0) m->NextuDNSEvent = d->penaltyTime; } #endif if (m->CurrentQuestion) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "uDNS_Tasks ERROR m->CurrentQuestion already set: " PRI_DM_NAME " (" PRI_S ")", DM_NAME_PARAM(&m->CurrentQuestion->qname), DNSTypeName(m->CurrentQuestion->qtype)); } m->CurrentQuestion = m->Questions; while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) { DNSQuestion *const q = m->CurrentQuestion; if (ActiveQuestion(q) && !mDNSOpaque16IsZero(q->TargetQID)) { uDNS_CheckCurrentQuestion(m); if (q == m->CurrentQuestion) if (m->NextuDNSEvent - NextQSendTime(q) > 0) m->NextuDNSEvent = NextQSendTime(q); } // If m->CurrentQuestion wasn't modified out from under us, advance it now // We can't do this at the start of the loop because uDNS_CheckCurrentQuestion() // depends on having m->CurrentQuestion point to the right question if (m->CurrentQuestion == q) m->CurrentQuestion = q->next; } m->CurrentQuestion = mDNSNULL; } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - Startup, Shutdown, and Sleep #endif mDNSexport void SleepRecordRegistrations(mDNS *m) { AuthRecord *rr; for (rr = m->ResourceRecords; rr; rr=rr->next) { if (AuthRecord_uDNS(rr)) { // Zero out the updateid so that if we have a pending response from the server, it won't // be accepted as a valid response. if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); rr->nta = mDNSNULL; } if (rr->NATinfo.clientContext) { mDNS_StopNATOperation_internal(m, &rr->NATinfo); rr->NATinfo.clientContext = mDNSNULL; } // We are waiting to update the resource record. The original data of the record is // in OrigRData and the updated value is in InFlightRData. Free the old and the new // one will be registered when we come back. if (rr->state == regState_UpdatePending) { // act as if the update succeeded, since we're about to delete the name anyway rr->state = regState_Registered; // deallocate old RData if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->OrigRData, rr->OrigRDLen); SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); rr->OrigRData = mDNSNULL; rr->InFlightRData = mDNSNULL; } // If we have not begun the registration process i.e., never sent a registration packet, // then uDNS_DeregisterRecord will not send a deregistration uDNS_DeregisterRecord(m, rr); // When we wake, we call ActivateUnicastRegistration which starts at StartGetZoneData } } } mDNSexport void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID) { SearchListElem **p; SearchListElem *tmp = mDNSNULL; // Check to see if we already have this domain in our list for (p = &SearchList; *p; p = &(*p)->next) if (((*p)->InterfaceID == InterfaceID) && SameDomainName(&(*p)->domain, domain)) { // If domain is already in list, and marked for deletion, unmark the delete // Be careful not to touch the other flags that may be present LogInfo("mDNS_AddSearchDomain already in list %##s", domain->c); if ((*p)->flag & SLE_DELETE) (*p)->flag &= ~SLE_DELETE; tmp = *p; *p = tmp->next; tmp->next = mDNSNULL; break; } // move to end of list so that we maintain the same order while (*p) p = &(*p)->next; if (tmp) *p = tmp; else { // if domain not in list, add to list, mark as add (1) *p = (SearchListElem *) mDNSPlatformMemAllocateClear(sizeof(**p)); if (!*p) { LogMsg("ERROR: mDNS_AddSearchDomain - malloc"); return; } AssignDomainName(&(*p)->domain, domain); (*p)->next = mDNSNULL; (*p)->InterfaceID = InterfaceID; LogInfo("mDNS_AddSearchDomain created new %##s, InterfaceID %p", domain->c, InterfaceID); } } mDNSlocal void FreeARElemCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { (void)m; // unused if (result == mStatus_MemFree) mDNSPlatformMemFree(rr->RecordContext); } mDNSlocal void FoundDomain(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) { SearchListElem *slElem = question->QuestionContext; mStatus err; const char *name; if (answer->rrtype != kDNSType_PTR) return; if (answer->RecordType == kDNSRecordTypePacketNegative) return; if (answer->InterfaceID == mDNSInterface_LocalOnly) return; if (question == &slElem->BrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowse]; else if (question == &slElem->DefBrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseDefault]; else if (question == &slElem->AutomaticBrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseAutomatic]; else if (question == &slElem->RegisterQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeRegistration]; else if (question == &slElem->DefRegisterQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeRegistrationDefault]; else { LogMsg("FoundDomain - unknown question"); return; } LogInfo("FoundDomain: %p %s %s Q %##s A %s", answer->InterfaceID, AddRecord ? "Add" : "Rmv", name, question->qname.c, RRDisplayString(m, answer)); if (AddRecord) { ARListElem *arElem = (ARListElem *) mDNSPlatformMemAllocateClear(sizeof(*arElem)); if (!arElem) { LogMsg("ERROR: FoundDomain out of memory"); return; } mDNS_SetupResourceRecord(&arElem->ar, mDNSNULL, mDNSInterface_LocalOnly, kDNSType_PTR, 7200, kDNSRecordTypeShared, AuthRecordLocalOnly, FreeARElemCallback, arElem); MakeDomainNameFromDNSNameString(&arElem->ar.namestorage, name); AppendDNSNameString (&arElem->ar.namestorage, "local"); AssignDomainName(&arElem->ar.resrec.rdata->u.name, &answer->rdata->u.name); LogInfo("FoundDomain: Registering %s", ARDisplayString(m, &arElem->ar)); err = mDNS_Register(m, &arElem->ar); if (err) { LogMsg("ERROR: FoundDomain - mDNS_Register returned %d", err); mDNSPlatformMemFree(arElem); return; } arElem->next = slElem->AuthRecs; slElem->AuthRecs = arElem; } else { ARListElem **ptr = &slElem->AuthRecs; while (*ptr) { if (SameDomainName(&(*ptr)->ar.resrec.rdata->u.name, &answer->rdata->u.name)) { ARListElem *dereg = *ptr; *ptr = (*ptr)->next; LogInfo("FoundDomain: Deregistering %s", ARDisplayString(m, &dereg->ar)); err = mDNS_Deregister(m, &dereg->ar); if (err) LogMsg("ERROR: FoundDomain - mDNS_Deregister returned %d", err); // Memory will be freed in the FreeARElemCallback } else ptr = &(*ptr)->next; } } } #if APPLE_OSX_mDNSResponder && MACOSX_MDNS_MALLOC_DEBUGGING mDNSexport void udns_validatelists(void *const v) { mDNS *const m = v; NATTraversalInfo *n; for (n = m->NATTraversals; n; n=n->next) if (n->next == (NATTraversalInfo *)~0 || n->clientCallback == (NATTraversalClientCallback) ~0) LogMemCorruption("m->NATTraversals: %p is garbage", n); DNSServer *d; for (d = m->DNSServers; d; d=d->next) if (d->next == (DNSServer *)~0) LogMemCorruption("m->DNSServers: %p is garbage", d); DomainAuthInfo *info; for (info = m->AuthInfoList; info; info = info->next) if (info->next == (DomainAuthInfo *)~0) LogMemCorruption("m->AuthInfoList: %p is garbage", info); HostnameInfo *hi; for (hi = m->Hostnames; hi; hi = hi->next) if (hi->next == (HostnameInfo *)~0 || hi->StatusCallback == (mDNSRecordCallback*)~0) LogMemCorruption("m->Hostnames: %p is garbage", n); SearchListElem *ptr; for (ptr = SearchList; ptr; ptr = ptr->next) if (ptr->next == (SearchListElem *)~0 || ptr->AuthRecs == (void*)~0) LogMemCorruption("SearchList: %p is garbage (%X)", ptr, ptr->AuthRecs); } #endif // This should probably move to the UDS daemon -- the concept of legacy clients and automatic registration / automatic browsing // is really a UDS API issue, not something intrinsic to uDNS mDNSlocal void uDNS_DeleteWABQueries(mDNS *const m, SearchListElem *ptr, int delete) { const char *name1 = mDNSNULL; const char *name2 = mDNSNULL; ARListElem **arList = &ptr->AuthRecs; domainname namestorage1, namestorage2; mStatus err; // "delete" parameter indicates the type of query. switch (delete) { case UDNS_WAB_BROWSE_QUERY: mDNS_StopGetDomains(m, &ptr->BrowseQ); mDNS_StopGetDomains(m, &ptr->DefBrowseQ); name1 = mDNS_DomainTypeNames[mDNS_DomainTypeBrowse]; name2 = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseDefault]; break; case UDNS_WAB_LBROWSE_QUERY: mDNS_StopGetDomains(m, &ptr->AutomaticBrowseQ); name1 = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseAutomatic]; break; case UDNS_WAB_REG_QUERY: mDNS_StopGetDomains(m, &ptr->RegisterQ); mDNS_StopGetDomains(m, &ptr->DefRegisterQ); name1 = mDNS_DomainTypeNames[mDNS_DomainTypeRegistration]; name2 = mDNS_DomainTypeNames[mDNS_DomainTypeRegistrationDefault]; break; default: LogMsg("uDNS_DeleteWABQueries: ERROR!! returning from default"); return; } // When we get the results to the domain enumeration queries, we add a LocalOnly // entry. For example, if we issue a domain enumeration query for b._dns-sd._udp.xxxx.com, // and when we get a response, we add a LocalOnly entry b._dns-sd._udp.local whose RDATA // points to what we got in the response. Locate the appropriate LocalOnly entries and delete // them. if (name1) { MakeDomainNameFromDNSNameString(&namestorage1, name1); AppendDNSNameString(&namestorage1, "local"); } if (name2) { MakeDomainNameFromDNSNameString(&namestorage2, name2); AppendDNSNameString(&namestorage2, "local"); } while (*arList) { ARListElem *dereg = *arList; if ((name1 && SameDomainName(&dereg->ar.namestorage, &namestorage1)) || (name2 && SameDomainName(&dereg->ar.namestorage, &namestorage2))) { LogInfo("uDNS_DeleteWABQueries: Deregistering PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); *arList = dereg->next; err = mDNS_Deregister(m, &dereg->ar); if (err) LogMsg("uDNS_DeleteWABQueries:: ERROR!! mDNS_Deregister returned %d", err); // Memory will be freed in the FreeARElemCallback } else { LogInfo("uDNS_DeleteWABQueries: Skipping PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); arList = &(*arList)->next; } } } mDNSexport void uDNS_SetupWABQueries(mDNS *const m) { SearchListElem **p = &SearchList, *ptr; mStatus err; int action = 0; // step 1: mark each element for removal for (ptr = SearchList; ptr; ptr = ptr->next) ptr->flag |= SLE_DELETE; // Make sure we have the search domains from the platform layer so that if we start the WAB // queries below, we have the latest information. mDNS_Lock(m); if (!mDNSPlatformSetDNSConfig(mDNSfalse, mDNStrue, mDNSNULL, mDNSNULL, mDNSNULL, mDNSfalse)) { // If the configuration did not change, clear the flag so that we don't free the searchlist. // We still have to start the domain enumeration queries as we may not have started them // before. for (ptr = SearchList; ptr; ptr = ptr->next) ptr->flag &= ~SLE_DELETE; LogInfo("uDNS_SetupWABQueries: No config change"); } mDNS_Unlock(m); if (m->WABBrowseQueriesCount) action |= UDNS_WAB_BROWSE_QUERY; if (m->WABLBrowseQueriesCount) action |= UDNS_WAB_LBROWSE_QUERY; if (m->WABRegQueriesCount) action |= UDNS_WAB_REG_QUERY; // delete elems marked for removal, do queries for elems marked add while (*p) { ptr = *p; LogInfo("uDNS_SetupWABQueries:action 0x%x: Flags 0x%x, AuthRecs %p, InterfaceID %p %##s", action, ptr->flag, ptr->AuthRecs, ptr->InterfaceID, ptr->domain.c); // If SLE_DELETE is set, stop all the queries, deregister all the records and free the memory. // Otherwise, check to see what the "action" requires. If a particular action bit is not set and // we have started the corresponding queries as indicated by the "flags", stop those queries and // deregister the records corresponding to them. if ((ptr->flag & SLE_DELETE) || (!(action & UDNS_WAB_BROWSE_QUERY) && (ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED)) || (!(action & UDNS_WAB_LBROWSE_QUERY) && (ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED)) || (!(action & UDNS_WAB_REG_QUERY) && (ptr->flag & SLE_WAB_REG_QUERY_STARTED))) { if (ptr->flag & SLE_DELETE) { ARListElem *arList = ptr->AuthRecs; ptr->AuthRecs = mDNSNULL; *p = ptr->next; // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries // We suppressed the domain enumeration for scoped search domains below. When we enable that // enable this. if ((ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED) && !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { LogInfo("uDNS_SetupWABQueries: DELETE Browse for domain %##s", ptr->domain.c); mDNS_StopGetDomains(m, &ptr->BrowseQ); mDNS_StopGetDomains(m, &ptr->DefBrowseQ); } if ((ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED) && !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { LogInfo("uDNS_SetupWABQueries: DELETE Legacy Browse for domain %##s", ptr->domain.c); mDNS_StopGetDomains(m, &ptr->AutomaticBrowseQ); } if ((ptr->flag & SLE_WAB_REG_QUERY_STARTED) && !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { LogInfo("uDNS_SetupWABQueries: DELETE Registration for domain %##s", ptr->domain.c); mDNS_StopGetDomains(m, &ptr->RegisterQ); mDNS_StopGetDomains(m, &ptr->DefRegisterQ); } mDNSPlatformMemFree(ptr); // deregister records generated from answers to the query while (arList) { ARListElem *dereg = arList; arList = arList->next; LogInfo("uDNS_SetupWABQueries: DELETE Deregistering PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); err = mDNS_Deregister(m, &dereg->ar); if (err) LogMsg("uDNS_SetupWABQueries:: ERROR!! mDNS_Deregister returned %d", err); // Memory will be freed in the FreeARElemCallback } continue; } // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries // We suppressed the domain enumeration for scoped search domains below. When we enable that // enable this. if (!(action & UDNS_WAB_BROWSE_QUERY) && (ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED) && !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { LogInfo("uDNS_SetupWABQueries: Deleting Browse for domain %##s", ptr->domain.c); ptr->flag &= ~SLE_WAB_BROWSE_QUERY_STARTED; uDNS_DeleteWABQueries(m, ptr, UDNS_WAB_BROWSE_QUERY); } if (!(action & UDNS_WAB_LBROWSE_QUERY) && (ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED) && !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { LogInfo("uDNS_SetupWABQueries: Deleting Legacy Browse for domain %##s", ptr->domain.c); ptr->flag &= ~SLE_WAB_LBROWSE_QUERY_STARTED; uDNS_DeleteWABQueries(m, ptr, UDNS_WAB_LBROWSE_QUERY); } if (!(action & UDNS_WAB_REG_QUERY) && (ptr->flag & SLE_WAB_REG_QUERY_STARTED) && !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { LogInfo("uDNS_SetupWABQueries: Deleting Registration for domain %##s", ptr->domain.c); ptr->flag &= ~SLE_WAB_REG_QUERY_STARTED; uDNS_DeleteWABQueries(m, ptr, UDNS_WAB_REG_QUERY); } // Fall through to handle the ADDs } if ((action & UDNS_WAB_BROWSE_QUERY) && !(ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED)) { // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. // Also, suppress the domain enumeration for scoped search domains for now until there is a need. if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { mStatus err1, err2; err1 = mDNS_GetDomains(m, &ptr->BrowseQ, mDNS_DomainTypeBrowse, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); if (err1) { LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" "%d (mDNS_DomainTypeBrowse)\n", ptr->domain.c, err1); } else { LogInfo("uDNS_SetupWABQueries: Starting Browse for domain %##s", ptr->domain.c); } err2 = mDNS_GetDomains(m, &ptr->DefBrowseQ, mDNS_DomainTypeBrowseDefault, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); if (err2) { LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" "%d (mDNS_DomainTypeBrowseDefault)\n", ptr->domain.c, err2); } else { LogInfo("uDNS_SetupWABQueries: Starting Default Browse for domain %##s", ptr->domain.c); } // For simplicity, we mark a single bit for denoting that both the browse queries have started. // It is not clear as to why one would fail to start and the other would succeed in starting up. // If that happens, we will try to stop both the queries and one of them won't be in the list and // it is not a hard error. if (!err1 || !err2) { ptr->flag |= SLE_WAB_BROWSE_QUERY_STARTED; } } } if ((action & UDNS_WAB_LBROWSE_QUERY) && !(ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED)) { // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. // Also, suppress the domain enumeration for scoped search domains for now until there is a need. if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { mStatus err1; err1 = mDNS_GetDomains(m, &ptr->AutomaticBrowseQ, mDNS_DomainTypeBrowseAutomatic, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); if (err1) { LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" "%d (mDNS_DomainTypeBrowseAutomatic)\n", ptr->domain.c, err1); } else { ptr->flag |= SLE_WAB_LBROWSE_QUERY_STARTED; LogInfo("uDNS_SetupWABQueries: Starting Legacy Browse for domain %##s", ptr->domain.c); } } } if ((action & UDNS_WAB_REG_QUERY) && !(ptr->flag & SLE_WAB_REG_QUERY_STARTED)) { // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. // Also, suppress the domain enumeration for scoped search domains for now until there is a need. if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) { mStatus err1, err2; err1 = mDNS_GetDomains(m, &ptr->RegisterQ, mDNS_DomainTypeRegistration, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); if (err1) { LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" "%d (mDNS_DomainTypeRegistration)\n", ptr->domain.c, err1); } else { LogInfo("uDNS_SetupWABQueries: Starting Registration for domain %##s", ptr->domain.c); } err2 = mDNS_GetDomains(m, &ptr->DefRegisterQ, mDNS_DomainTypeRegistrationDefault, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); if (err2) { LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" "%d (mDNS_DomainTypeRegistrationDefault)", ptr->domain.c, err2); } else { LogInfo("uDNS_SetupWABQueries: Starting Default Registration for domain %##s", ptr->domain.c); } if (!err1 || !err2) { ptr->flag |= SLE_WAB_REG_QUERY_STARTED; } } } p = &ptr->next; } } // mDNS_StartWABQueries is called once per API invocation where normally // one of the bits is set. mDNSexport void uDNS_StartWABQueries(mDNS *const m, int queryType) { if (queryType & UDNS_WAB_BROWSE_QUERY) { m->WABBrowseQueriesCount++; LogInfo("uDNS_StartWABQueries: Browse query count %d", m->WABBrowseQueriesCount); } if (queryType & UDNS_WAB_LBROWSE_QUERY) { m->WABLBrowseQueriesCount++; LogInfo("uDNS_StartWABQueries: Legacy Browse query count %d", m->WABLBrowseQueriesCount); } if (queryType & UDNS_WAB_REG_QUERY) { m->WABRegQueriesCount++; LogInfo("uDNS_StartWABQueries: Reg query count %d", m->WABRegQueriesCount); } uDNS_SetupWABQueries(m); } // mDNS_StopWABQueries is called once per API invocation where normally // one of the bits is set. mDNSexport void uDNS_StopWABQueries(mDNS *const m, int queryType) { if (queryType & UDNS_WAB_BROWSE_QUERY) { m->WABBrowseQueriesCount--; LogInfo("uDNS_StopWABQueries: Browse query count %d", m->WABBrowseQueriesCount); } if (queryType & UDNS_WAB_LBROWSE_QUERY) { m->WABLBrowseQueriesCount--; LogInfo("uDNS_StopWABQueries: Legacy Browse query count %d", m->WABLBrowseQueriesCount); } if (queryType & UDNS_WAB_REG_QUERY) { m->WABRegQueriesCount--; LogInfo("uDNS_StopWABQueries: Reg query count %d", m->WABRegQueriesCount); } uDNS_SetupWABQueries(m); } mDNSexport domainname *uDNS_GetNextSearchDomain(mDNSInterfaceID InterfaceID, int *searchIndex, mDNSBool ignoreDotLocal) { SearchListElem *p = SearchList; int count = *searchIndex; if (count < 0) { LogMsg("uDNS_GetNextSearchDomain: count %d less than zero", count); return mDNSNULL; } // Skip the domains that we already looked at before. Guard against "p" // being NULL. When search domains change we may not set the SearchListIndex // of the question to zero immediately e.g., domain enumeration query calls // uDNS_SetupWABQueries which reads in the new search domain but does not // restart the questions immediately. Questions are restarted as part of // network change and hence temporarily SearchListIndex may be out of range. for (; count && p; count--) p = p->next; while (p) { int labels = CountLabels(&p->domain); if (labels > 0) { const domainname *d = SkipLeadingLabels(&p->domain, labels - 1); if (SameDomainLabel(d->c, (const mDNSu8 *)"\x4" "arpa")) { LogInfo("uDNS_GetNextSearchDomain: skipping search domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); (*searchIndex)++; p = p->next; continue; } if (ignoreDotLocal && SameDomainLabel(d->c, (const mDNSu8 *)"\x5" "local")) { LogInfo("uDNS_GetNextSearchDomain: skipping local domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); (*searchIndex)++; p = p->next; continue; } } // Point to the next one in the list which we will look at next time. (*searchIndex)++; if (p->InterfaceID == InterfaceID) { LogInfo("uDNS_GetNextSearchDomain returning domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); return &p->domain; } LogInfo("uDNS_GetNextSearchDomain skipping domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); p = p->next; } return mDNSNULL; } mDNSexport void uDNS_RestartQuestionAsTCP(mDNS *m, DNSQuestion *const q, const mDNSAddr *const srcaddr, const mDNSIPPort srcport) { // Don't reuse TCP connections. We might have failed over to a different DNS server // while the first TCP connection is in progress. We need a new TCP connection to the // new DNS server. So, always try to establish a new connection. if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } q->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_Zero, srcaddr, srcport, mDNSNULL, q, mDNSNULL); } mDNSlocal void FlushAddressCacheRecords(mDNS *const m) { mDNSu32 slot; CacheGroup *cg; CacheRecord *cr; FORALL_CACHERECORDS(slot, cg, cr) { if (cr->resrec.InterfaceID) continue; // If a resource record can answer A or AAAA, they need to be flushed so that we will // deliver an ADD or RMV if (RRTypeAnswersQuestionType(&cr->resrec, kDNSType_A) || RRTypeAnswersQuestionType(&cr->resrec, kDNSType_AAAA)) { LogInfo("FlushAddressCacheRecords: Purging Resourcerecord %s", CRDisplayString(m, cr)); mDNS_PurgeCacheResourceRecord(m, cr); } } } // Retry questions which has seach domains appended mDNSexport void RetrySearchDomainQuestions(mDNS *const m) { DNSQuestion *q; mDNSBool found = mDNSfalse; // Check to see if there are any questions which needs search domains to be applied. // If there is none, search domains can't possibly affect them. for (q = m->Questions; q; q = q->next) { if (q->AppendSearchDomains) { found = mDNStrue; break; } } if (!found) { LogInfo("RetrySearchDomainQuestions: Questions with AppendSearchDomain not found"); return; } LogInfo("RetrySearchDomainQuestions: Question with AppendSearchDomain found %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); // Purge all the A/AAAA cache records and restart the queries. mDNSCoreRestartAddressQueries // does this. When we restart the question, we first want to try the new search domains rather // than use the entries that is already in the cache. When we appended search domains, we might // have created cache entries which is no longer valid as there are new search domains now mDNSCoreRestartAddressQueries(m, mDNStrue, FlushAddressCacheRecords, mDNSNULL, mDNSNULL); } // Construction of Default Browse domain list (i.e. when clients pass NULL) is as follows: // 1) query for b._dns-sd._udp.local on LocalOnly interface // (.local manually generated via explicit callback) // 2) for each search domain (from prefs pane), query for b._dns-sd._udp.. // 3) for each result from (2), register LocalOnly PTR record b._dns-sd._udp.local. -> // 4) result above should generate a callback from question in (1). result added to global list // 5) global list delivered to client via GetSearchDomainList() // 6) client calls to enumerate domains now go over LocalOnly interface // (!!!KRS may add outgoing interface in addition) struct CompileTimeAssertionChecks_uDNS { // Check our structures are reasonable sizes. Including overly-large buffers, or embedding // other overly-large structures instead of having a pointer to them, can inadvertently // cause structure sizes (and therefore memory usage) to balloon unreasonably. char sizecheck_tcpInfo_t [(sizeof(tcpInfo_t) <= 9056) ? 1 : -1]; char sizecheck_SearchListElem[(sizeof(SearchListElem) <= 6381) ? 1 : -1]; }; #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - DNS Push Notification functions #endif #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) mDNSlocal void DNSPushProcessResponse(mDNS *const m, const DNSMessage *const msg, DNSPushNotificationServer *server, ResourceRecord *mrr) { // "(CacheRecord*)1" is a special (non-zero) end-of-list marker // We use this non-zero marker so that records in our CacheFlushRecords list will always have NextInCFList // set non-zero, and that tells GetCacheEntity() that they're not, at this moment, eligible for recycling. CacheRecord *CacheFlushRecords = (CacheRecord*)1; CacheRecord **cfp = &CacheFlushRecords; enum { removeName, removeClass, removeRRset, removeRR, addRR } action; // Ignore records we don't want to cache. // Don't want to cache OPT or TSIG pseudo-RRs if (mrr->rrtype == kDNSType_TSIG) { return; } if (mrr->rrtype == kDNSType_OPT) { return; } if ((mrr->rrtype == kDNSType_CNAME) && SameDomainName(mrr->name, &mrr->rdata->u.name)) { LogInfo("DNSPushProcessResponse: CNAME loop domain name %##s", mrr->name->c); return; } // TTL == -1: delete individual record // TTL == -2: wildcard delete // CLASS != ANY, TYPE != ANY: delete all records of specified type and class // CLASS != ANY, TYPE == ANY: delete all RRs of specified class // CLASS == ANY: delete all RRs on the name, regardless of type or class (TYPE is ignored). // If TTL is zero, this is a delete, not an add. if ((mDNSs32)mrr->rroriginalttl == -1) { LogMsg("DNSPushProcessResponse: Got remove on %##s with type %s", mrr->name, DNSTypeName(mrr->rrtype)); action = removeRR; } else if ((mDNSs32)mrr->rroriginalttl == -2) { if (mrr->rrclass == kDNSQClass_ANY) { LogMsg("DNSPushProcessResponse: Got Remove Name on %##s", mrr->name); action = removeName; } else if (mrr->rrtype == kDNSQType_ANY) { LogMsg("DNSPushProcessResponse: Got Remove Name on %##s", mrr->name); action = removeClass; } else { LogMsg("DNSPushProcessResponse: Got Remove RRset on %##s, type %s, rdlength %d", mrr->name, DNSTypeName(mrr->rrtype), mrr->rdlength); action = removeRRset; } } else { action = addRR; } if (action != addRR) { if (m->rrcache_size) { CacheRecord *rr; // Remember the unicast question that we found, which we use to make caching // decisions later on in this function CacheGroup *cg = CacheGroupForName(m, mrr->namehash, mrr->name); for (rr = cg ? cg->members : mDNSNULL; rr; rr=rr->next) { if ( action == removeName || (action == removeClass && rr->resrec.rrclass == mrr->rrclass) || (rr->resrec.rrclass == mrr->rrclass && ((action == removeRRset && rr->resrec.rrtype == mrr->rrtype) || (action == removeRR && rr->resrec.rrtype == mrr->rrtype && SameRDataBody(mrr, &rr->resrec.rdata->u, SameDomainName))))) { LogInfo("DNSPushProcessResponse purging %##s (%s) %s", rr->resrec.name, DNSTypeName(mrr->rrtype), CRDisplayString(m, rr)); // We've found a cache entry to delete. Now what? mDNS_PurgeCacheResourceRecord(m, rr); } } } } else { // It's an add. LogMsg("DNSPushProcessResponse: Got add RR on %##s, type %s, length %d", mrr->name, DNSTypeName(mrr->rrtype), mrr->rdlength); // When we receive DNS Push responses, we assume a long cache lifetime -- // This path is only reached for DNS Push responses; as long as the connection to the server is // live, the RR should stay updated. mrr->rroriginalttl = kLLQ_DefLease /* XXX */; // Use the DNS Server we remember from the question that created this DNS Push server structure. #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_replace(&mrr->dnsservice, server->dnsservice); #else mrr->rDNSServer = server->qDNSServer; #endif // 2. See if we want to add this packet resource record to our cache // We only try to cache answers if we have a cache to put them in if (m->rrcache_size) { const mDNSu32 slot = HashSlotFromNameHash(mrr->namehash); CacheGroup *cg = CacheGroupForName(m, mrr->namehash, mrr->name); CacheRecord *rr = mDNSNULL; // 2a. Check if this packet resource record is already in our cache. rr = mDNSCoreReceiveCacheCheck(m, msg, uDNS_LLQ_Events, slot, cg, &cfp, mDNSNULL); // If packet resource record not in our cache, add it now // (unless it is just a deletion of a record we never had, in which case we don't care) if (!rr && mrr->rroriginalttl > 0) { rr = CreateNewCacheEntry(m, slot, cg, 0, mDNStrue, &server->connection->transport->remote_addr); if (rr) { // Not clear that this is ever used, but for verisimilitude, set this to look like // an authoritative response to a regular query. rr->responseFlags.b[0] = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery | kDNSFlag0_AA; rr->responseFlags.b[1] = kDNSFlag1_RC_NoErr | kDNSFlag0_AA; } } } } } mDNSlocal void DNSPushProcessResponses(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *firstAnswer, const mDNSu8 *const end, DNSPushNotificationServer *server) { DNSQuestion *q; const mDNSu8 *ptr = firstAnswer; mDNSIPPort port; port.NotAnInteger = 0; ResourceRecord *mrr = &m->rec.r.resrec; // Validate the contents of the message // XXX Right now this code will happily parse all the valid data and then hit invalid data // and give up. I don't think there's a risk here, but we should discuss it. // XXX what about source validation? Like, if we have a VPN, are we safe? I think yes, but let's think about it. while ((ptr = GetLargeResourceRecord(m, msg, ptr, end, mDNSNULL, kDNSRecordTypePacketAns, &m->rec))) { int gotOne = 0; for (q = m->Questions; q; q = q->next) { if (q->LongLived && (q->qtype == mrr->rrtype || q->qtype == kDNSServiceType_ANY) && q->qnamehash == mrr->namehash && SameDomainName(&q->qname, mrr->name)) { LogMsg("DNSPushProcessResponses found %##s (%s) %d %s %s", q->qname.c, DNSTypeName(q->qtype), q->state, q->dnsPushServer ? (q->dnsPushServer->connection ? q->dnsPushServer->connection->remote_name : "") : "", server->connection->remote_name); if (q->dnsPushServer == server) { gotOne++; DNSPushProcessResponse(m, msg, server, mrr); break; // question list may have changed } } } if (!gotOne) { LogMsg("DNSPushProcessResponses: no match for %##s %d %d", mrr->name, mrr->rrtype, mrr->rrclass); } mrr->RecordType = 0; // Clear RecordType to show we're not still using it } } static void DNSPushStartConnecting(DNSPushNotificationServer *server) { if (dso_connect(server->connectInfo)) { server->connectState = DNSPushServerConnectionInProgress; } else { server->connectState = DNSPushServerConnectFailed; } } mDNSexport void DNSPushReconcileConnection(mDNS *m, DNSQuestion *q) { DNSPushNotificationZone *zone; DNSPushNotificationZone *nextZone; if (q->dnsPushServer == mDNSNULL) { return; } // Update the counts for (zone = m->DNSPushZones; zone != mDNSNULL; zone = zone->next) { if (zone->server == q->dnsPushServer) { zone->numberOfQuestions--; } } q->dnsPushServer->numberOfQuestions--; nextZone = mDNSNULL; for (zone = m->DNSPushZones; zone != mDNSNULL; zone = nextZone) { nextZone = zone->next; if (zone->numberOfQuestions == 0) { if (zone == m->DNSPushZones) m->DNSPushZones = nextZone; LogInfo("DNSPushReconcileConnection: zone %##s is being freed", &zone->zoneName); mDNSPlatformMemFree(zone); } } q->dnsPushServer = mDNSNULL; } static const char kDNSPushActivity_Subscription[] = "dns-push-subscription"; static void DNSPushSendKeepalive(DNSPushNotificationServer *server, mDNSu32 inactivity_timeout, mDNSu32 keepalive_interval) { dso_message_t state; dso_transport_t *transport = server->connection->transport; if (transport == NULL || transport->outbuf == NULL) { // Should be impossible, don't crash. LogInfo("DNSPushNotificationSendSubscribe: no transport!"); return; } dso_make_message(&state, transport->outbuf, transport->outbuf_size, server->connection, false, 0); dso_start_tlv(&state, kDSOType_Keepalive); dso_add_tlv_u32(&state, inactivity_timeout); dso_add_tlv_u32(&state, keepalive_interval); dso_finish_tlv(&state); dso_message_write(server->connection, &state, mDNSfalse); } static void DNSPushNotificationSendSubscriptionChange(mDNSBool subscribe, dso_state_t *dso, DNSQuestion *q) { dso_message_t state; dso_transport_t *transport = dso->transport; mDNSu16 len; if (transport == NULL || transport->outbuf == NULL) { // Should be impossible, don't crash. LogInfo("DNSPushNotificationSendSubscribe: no transport!"); return; } dso_make_message(&state, transport->outbuf, transport->outbuf_size, dso, subscribe ? false : true, q); dso_start_tlv(&state, subscribe ? kDSOType_DNSPushSubscribe : kDSOType_DNSPushUnsubscribe); len = DomainNameLengthLimit(&q->qname, q->qname.c + (sizeof q->qname)); dso_add_tlv_bytes(&state, q->qname.c, len); dso_add_tlv_u16(&state, q->qtype); dso_add_tlv_u16(&state, q->qclass); dso_finish_tlv(&state); dso_message_write(dso, &state, mDNSfalse); } static void DNSPushStop(mDNS *m, DNSPushNotificationServer *server) { mDNSBool found = mDNStrue; DNSQuestion *q; while (found) { found = mDNSfalse; server->connectState = DNSPushServerNoDNSPush; for (q = m->Questions; q; q = q->next) { if (q->dnsPushServer == server) { DNSPushReconcileConnection(m, q); q->dnsPushServer = NULL; q->state = LLQ_Poll; q->ThisQInterval = 0; q->LastQTime = m->timenow; SetNextQueryTime(m, q); break; } } } } mDNSexport void DNSPushServerDrop(DNSPushNotificationServer *server) { if (server->connection) { dso_drop(server->connection); server->connection = NULL; } if (server->connectInfo) { dso_connect_state_drop(server->connectInfo); } } static void DNSPushServerFree(mDNS *m, DNSPushNotificationServer *server) { DNSPushNotificationServer **sp; DNSPushServerDrop(server); sp = &m->DNSPushServers; while (*sp) { if (*sp == server) { *sp = server->next; break; } else { sp = &server->next; } } mDNSPlatformMemFree(server); } static void DNSPushDSOCallback(void *context, const void *event_context, dso_state_t *dso, dso_event_type_t eventType) { const DNSMessage *message; DNSPushNotificationServer *server = context; dso_activity_t *activity; const dso_query_receive_context_t *receive_context; const dso_disconnect_context_t *disconnect_context; const dso_keepalive_context_t *keepalive_context; DNSQuestion *q; uint16_t rcode; mDNSs32 reconnect_when = 0; mDNS *m = server->m; mDNS_CheckLock(m); switch(eventType) { case kDSOEventType_DNSMessage: // We shouldn't get here because we won't use this connection for DNS messages. message = event_context; LogMsg("DNSPushDSOCallback: DNS Message (opcode=%d) received from %##s", (message->h.flags.b[0] & kDNSFlag0_OP_Mask) >> 3, &server->serverName); break; case kDSOEventType_DNSResponse: // We shouldn't get here because we already handled any DNS messages message = event_context; LogMsg("DNSPushDSOCallback: DNS Response (opcode=%d) received from %##s", (message->h.flags.b[0] & kDNSFlag0_OP_Mask) >> 3, &server->serverName); break; case kDSOEventType_DSOMessage: message = event_context; if (dso->primary.opcode == kDSOType_DNSPushUpdate) { DNSPushProcessResponses(server->m, message, dso->primary.payload, dso->primary.payload + dso->primary.length, server); } else { dso_send_not_implemented(dso, &message->h); LogMsg("DNSPushDSOCallback: Unknown DSO Message (Primary TLV=%d) received from %##s", dso->primary.opcode, &server->serverName); } break; case kDSOEventType_DSOResponse: receive_context = event_context; q = receive_context->query_context; rcode = receive_context->rcode; if (q) { // If we got an error on a subscribe, we need to evaluate what went wrong if (rcode == kDNSFlag1_RC_NoErr) { LogMsg("DNSPushDSOCallback: Subscription for %##s/%d/%d succeeded.", q->qname.c, q->qtype, q->qclass); q->state = LLQ_DNSPush_Established; server->connectState = DNSPushServerSessionEstablished; } else { // Don't use this server. q->dnsPushServer->connectState = DNSPushServerNoDNSPush; q->state = LLQ_Poll; q->ThisQInterval = 0; q->LastQTime = m->timenow; SetNextQueryTime(m, q); LogMsg("DNSPushDSOCallback: Subscription for %##s/%d/%d failed.", q->qname.c, q->qtype, q->qclass); } } else { LogMsg("DNSPushDSOCallback: DSO Response (Primary TLV=%d) (RCODE=%d) (no query) received from %##s", dso->primary.opcode, receive_context->rcode, &server->serverName); server->connectState = DNSPushServerSessionEstablished; } break; case kDSOEventType_Finalize: LogMsg("DNSPushDSOCallback: Finalize"); break; case kDSOEventType_Connected: LogMsg("DNSPushDSOCallback: Connected to %##s", &server->serverName); server->connectState = DNSPushServerConnected; for (activity = dso->activities; activity; activity = activity->next) { DNSPushNotificationSendSubscriptionChange(mDNStrue, dso, activity->context); } break; case kDSOEventType_ConnectFailed: DNSPushStop(m, server); LogMsg("DNSPushDSOCallback: Connection to %##s failed", &server->serverName); break; case kDSOEventType_Disconnected: disconnect_context = event_context; // If a network glitch broke the connection, try to reconnect immediately. But if this happens // twice, don't just blindly reconnect. if (disconnect_context->reconnect_delay == 0) { if ((server->lastDisconnect + 90 * mDNSPlatformOneSecond) - m->timenow > 0) { reconnect_when = 3600000; // If we get two disconnects in quick succession, wait an hour before trying again. } else { DNSPushStartConnecting(server); LogMsg("DNSPushDSOCallback: Connection to %##s disconnected, trying immediate reconnect", &server->serverName); } } else { reconnect_when = disconnect_context->reconnect_delay; } if (reconnect_when != 0) { LogMsg("DNSPushDSOCallback: Holding server %##s out as not reconnectable for %lf seconds", &server->serverName, 1000.0 * (reconnect_when - m->timenow) / (double)mDNSPlatformOneSecond); dso_schedule_reconnect(m, server->connectInfo, reconnect_when); } server->lastDisconnect = m->timenow; server->connection = mDNSNULL; break; // We don't reconnect unless there is demand. The reason we have this event is so that we can // leave the DNSPushNotificationServer data structure around to _prevent_ attempts to reconnect // before the reconnect delay interval has expired. When we get this call, we just free up the // server. case kDSOEventType_ShouldReconnect: // This should be unnecessary, but it would be bad to accidentally have a question pointing at // a server that had been freed, so make sure we don't. LogMsg("DNSPushDSOCallback: ShouldReconnect timer for %##s fired, disposing of it.", &server->serverName); DNSPushStop(m, server); DNSPushServerFree(m, server); break; case kDSOEventType_Keepalive: LogMsg("DNSPushDSOCallback: Keepalive timer for %##s fired.", &server->serverName); keepalive_context = event_context; DNSPushSendKeepalive(server, keepalive_context->inactivity_timeout, keepalive_context->keepalive_interval); break; case kDSOEventType_KeepaliveRcvd: LogMsg("DNSPushDSOCallback: Keepalive message received from %##s.", &server->serverName); break; case kDSOEventType_Inactive: // The set of activities went to zero, and we set the idle timeout. And it expired without any // new activities starting. So we can disconnect. LogMsg("DNSPushDSOCallback: Inactivity timer for %##s fired, disposing of it.", &server->serverName); DNSPushStop(m, server); DNSPushServerFree(m, server); break; case kDSOEventType_RetryDelay: disconnect_context = event_context; DNSPushStop(m, server); dso_schedule_reconnect(m, server->connectInfo, disconnect_context->reconnect_delay); break; } } DNSPushNotificationServer *GetConnectionToDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { DNSPushNotificationZone *zone; DNSPushNotificationServer *server; DNSPushNotificationZone *newZone; DNSPushNotificationServer *newServer; char name[MAX_ESCAPED_DOMAIN_NAME]; // If we already have a question for this zone and if the server is the same, reuse it for (zone = m->DNSPushZones; zone != mDNSNULL; zone = zone->next) { LogMsg("GetConnectionToDNSPushNotificationServer: zone compare zone %##s question %##s", &zone->zoneName, &q->nta->ChildName); if (SameDomainName(&q->nta->ChildName, &zone->zoneName)) { DNSPushNotificationServer *zoneServer = mDNSNULL; zoneServer = zone->server; if (zoneServer != mDNSNULL) { LogMsg("GetConnectionToDNSPushNotificationServer: server compare server %##s question %##s", &zoneServer->serverName, &q->nta->Host); if (SameDomainName(&q->nta->Host, &zoneServer->serverName)) { LogMsg("GetConnectionToDNSPushNotificationServer: server and zone already present."); zone->numberOfQuestions++; zoneServer->numberOfQuestions++; return zoneServer; } } } } // If we have a connection to this server but it is for a differnt zone, create a new zone entry and reuse the connection for (server = m->DNSPushServers; server != mDNSNULL; server = server->next) { LogMsg("GetConnectionToDNSPushNotificationServer: server compare server %##s question %##s", &server->serverName, &q->nta->Host); if (SameDomainName(&q->nta->Host, &server->serverName)) { newZone = (DNSPushNotificationZone *) mDNSPlatformMemAllocateClear(sizeof(*newZone)); if (newZone == NULL) { return NULL; } newZone->numberOfQuestions = 1; newZone->zoneName = q->nta->ChildName; newZone->server = server; // Add the new zone to the begining of the list newZone->next = m->DNSPushZones; m->DNSPushZones = newZone; server->numberOfQuestions++; LogMsg("GetConnectionToDNSPushNotificationServer: server already present."); return server; } } // If we do not have any existing connections, create a new connection newServer = (DNSPushNotificationServer *) mDNSPlatformMemAllocateClear(sizeof(*newServer)); if (newServer == NULL) { return NULL; } newZone = (DNSPushNotificationZone *) mDNSPlatformMemAllocateClear(sizeof(*newZone)); if (newZone == NULL) { mDNSPlatformMemFree(newServer); return NULL; } newServer->m = m; newServer->numberOfQuestions = 1; AssignDomainName(&newServer->serverName, &q->nta->Host); newServer->port = q->nta->Port; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_replace(&newServer->dnsservice, q->dnsservice); #else newServer->qDNSServer = q->qDNSServer; #endif ConvertDomainNameToCString(&newServer->serverName, name); newServer->connection = dso_create(mDNSfalse, 10, name, DNSPushDSOCallback, newServer, NULL); if (newServer->connection == NULL) { mDNSPlatformMemFree(newServer); mDNSPlatformMemFree(newZone); return NULL; } newServer->connectInfo = dso_connect_state_create(name, mDNSNULL, newServer->port, 10, AbsoluteMaxDNSMessageData, AbsoluteMaxDNSMessageData, DNSPushDSOCallback, newServer->connection, newServer, "GetDSOConnectionToPushServer"); if (newServer->connectInfo) { dso_connect_state_use_tls(newServer->connectInfo); DNSPushStartConnecting(newServer); } else { newServer->connectState = DNSPushServerConnectFailed; } newZone->numberOfQuestions = 1; newZone->zoneName = q->nta->ChildName; newZone->server = newServer; // Add the new zone to the begining of the list newZone->next = m->DNSPushZones; m->DNSPushZones = newZone; newServer->next = m->DNSPushServers; m->DNSPushServers = newServer; LogMsg("GetConnectionToDNSPushNotificationServer: allocated new server."); return newServer; } DNSPushNotificationServer *SubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { DNSPushNotificationServer *server = GetConnectionToDNSPushNotificationServer(m, q); char name[MAX_ESCAPED_DOMAIN_NAME + 9]; // type(hex)+class(hex)+name dso_activity_t *activity; if (server == mDNSNULL) return server; // Now we have a connection to a push notification server. It may be pending, or it may be active, // but either way we can add a DNS Push subscription to the server object. mDNS_snprintf(name, sizeof name, "%04x%04x", q->qtype, q->qclass); ConvertDomainNameToCString(&q->qname, &name[8]); activity = dso_add_activity(server->connection, name, kDNSPushActivity_Subscription, q, mDNSNULL); if (activity == mDNSNULL) { LogInfo("SubscribeToDNSPushNotificationServer: failed to add question %##s", &q->qname); return mDNSNULL; } // If we're already connected, send the subscribe request immediately. if (server->connectState == DNSPushServerConnected || server->connectState == DNSPushServerSessionEstablished) { DNSPushNotificationSendSubscriptionChange(mDNStrue, server->connection, q); } return server; } mDNSexport void DiscoverDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { LogInfo("DiscoverDNSPushNotificationServer: StartGetZoneData for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes q->LastQTime = m->timenow; SetNextQueryTime(m, q); if (q->nta) CancelGetZoneData(m, q->nta); q->nta = StartGetZoneData(m, &q->qname, ZoneServiceDNSPush, DNSPushNotificationGotZoneData, q); q->state = LLQ_DNSPush_ServerDiscovery; } mDNSexport void UnSubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { dso_activity_t *activity; if (q->dnsPushServer != mDNSNULL) { if (q->dnsPushServer->connection != mDNSNULL) { if (q->dnsPushServer->connectState == DNSPushServerSessionEstablished || q->dnsPushServer->connectState == DNSPushServerConnected) { // Ignore any response we get to a pending subscribe. dso_ignore_response(q->dnsPushServer->connection, q); DNSPushNotificationSendSubscriptionChange(mDNSfalse, q->dnsPushServer->connection, q); } // activities linger even if we are not connected. activity = dso_find_activity(q->dnsPushServer->connection, mDNSNULL, kDNSPushActivity_Subscription, q); if (activity != mDNSNULL) { dso_drop_activity(q->dnsPushServer->connection, activity); } } DNSPushReconcileConnection(m, q); } // We let the DSO Idle mechanism clean up the connection to the server. } #endif // MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #endif #else // !UNICAST_DISABLED mDNSexport const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr) { (void) m; (void) rr; return mDNSNULL; } mDNSexport DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name) { (void) m; (void) name; return mDNSNULL; } mDNSexport DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q) { (void) m; (void) q; return mDNSNULL; } mDNSexport void startLLQHandshake(mDNS *m, DNSQuestion *q) { (void) m; (void) q; } mDNSexport void DisposeTCPConn(struct tcpInfo_t *tcp) { (void) tcp; } mDNSexport mStatus mDNS_StartNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) { (void) m; (void) traversal; return mStatus_UnsupportedErr; } mDNSexport mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) { (void) m; (void) traversal; return mStatus_UnsupportedErr; } mDNSexport void sendLLQRefresh(mDNS *m, DNSQuestion *q) { (void) m; (void) q; } mDNSexport ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *ZoneDataContext) { (void) m; (void) name; (void) target; (void) callback; (void) ZoneDataContext; return mDNSNULL; } mDNSexport void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData) { (void) m; (void) err; (void) zoneData; } mDNSexport uDNS_LLQType uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion) { (void) m; (void) msg; (void) end; (void) srcaddr; (void) srcport; (void) matchQuestion; return uDNS_LLQ_Not; } mDNSexport void PenalizeDNSServer(mDNS *const m, DNSQuestion *q, mDNSOpaque16 responseFlags) { (void) m; (void) q; (void) responseFlags; } mDNSexport void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID) { (void) domain; (void) InterfaceID; } mDNSexport void RetrySearchDomainQuestions(mDNS *const m) { (void) m; } mDNSexport mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info, const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port) { (void) m; (void) info; (void) domain; (void) keyname; (void) b64keydata; (void) hostname; (void) port; return mStatus_UnsupportedErr; } mDNSexport domainname *uDNS_GetNextSearchDomain(mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal) { (void) InterfaceID; (void) searchIndex; (void) ignoreDotLocal; return mDNSNULL; } mDNSexport DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name) { (void) m; (void) name; return mDNSNULL; } mDNSexport mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal) { (void) m; (void) traversal; return mStatus_UnsupportedErr; } mDNSexport mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal) { (void) m; (void) traversal; return mStatus_UnsupportedErr; } mDNSexport DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, const mDNSs32 serviceID, const mDNSAddr *addr, const mDNSIPPort port, ScopeType scopeType, mDNSu32 timeout, mDNSBool isCell, mDNSBool isExpensive, mDNSBool isConstrained, mDNSBool isCLAT46, mDNSu32 resGroupID, mDNSBool reqA, mDNSBool reqAAAA, mDNSBool reqDO) { (void) m; (void) d; (void) interface; (void) serviceID; (void) addr; (void) port; (void) scopeType; (void) timeout; (void) isCell; (void) isExpensive; (void) isCLAT46; (void) isConstrained; (void) resGroupID; (void) reqA; (void) reqAAAA; (void) reqDO; return mDNSNULL; } mDNSexport void uDNS_SetupWABQueries(mDNS *const m) { (void) m; } mDNSexport void uDNS_StartWABQueries(mDNS *const m, int queryType) { (void) m; (void) queryType; } mDNSexport void uDNS_StopWABQueries(mDNS *const m, int queryType) { (void) m; (void) queryType; } mDNSexport void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext) { (void) m; (void) fqdn; (void) StatusCallback; (void) StatusContext; } mDNSexport void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router) { (void) m; (void) v4addr; (void) v6addr; (void) router; } mDNSexport void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn) { (void) m; (void) fqdn; } mDNSexport void RecreateNATMappings(mDNS *const m, const mDNSu32 waitTicks) { (void) m; (void) waitTicks; } mDNSexport mDNSBool IsGetZoneDataQuestion(DNSQuestion *q) { (void)q; return mDNSfalse; } mDNSexport void SubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { (void)m; (void)q; } mDNSexport void UnSubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { (void)m; (void)q; } mDNSexport void DiscoverDNSPushNotificationServer(mDNS *m, DNSQuestion *q) { (void)m; (void)q; } #endif // !UNICAST_DISABLED // Local Variables: // mode: C // tab-width: 4 // c-file-style: "bsd" // c-basic-offset: 4 // fill-column: 108 // indent-tabs-mode: nil // End: /* * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __UDNS_H_ #define __UDNS_H_ #include "mDNSEmbeddedAPI.h" #include "DNSCommon.h" #include #include "dns_sd.h" #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) #include "dso.h" #include "dso-transport.h" #endif #ifdef __cplusplus extern "C" { #endif #define RESTART_GOODBYE_DELAY (6 * mDNSPlatformOneSecond) // delay after restarting LLQ before nuking previous known answers (avoids flutter if we restart before we have networking up) #define INIT_UCAST_POLL_INTERVAL (3 * mDNSPlatformOneSecond) // this interval is used after send failures on network transitions // which typically heal quickly, so we start agressively and exponentially back off #define MAX_UCAST_POLL_INTERVAL (60 * 60 * mDNSPlatformOneSecond) //#define MAX_UCAST_POLL_INTERVAL (1 * 60 * mDNSPlatformOneSecond) #define LLQ_POLL_INTERVAL (15 * 60 * mDNSPlatformOneSecond) // Polling interval for zones w/ an advertised LLQ port (ie not static zones) if LLQ fails due to NAT, etc. #define RESPONSE_WINDOW (60 * mDNSPlatformOneSecond) // require server responses within one minute of request #define MAX_UCAST_UNANSWERED_QUERIES 2 // number of unanswered queries from any one uDNS server before trying another server #define DNSSERVER_PENALTY_TIME (60 * mDNSPlatformOneSecond) // number of seconds for which new questions don't pick this server // On some interfaces, we want to delay the first retransmission to a minimum of 2 seconds // rather than the default (1 second). #define MIN_UCAST_RETRANS_TIMEOUT (2 * mDNSPlatformOneSecond) #define DEFAULT_UPDATE_LEASE 7200 #define QuestionIntervalStep 3 #define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep) #define QuestionIntervalStep3 (QuestionIntervalStep*QuestionIntervalStep*QuestionIntervalStep) #define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep) #define MaxQuestionInterval (3600 * mDNSPlatformOneSecond) #define UDNSBackOffMultiplier 2 #define MinQuestionInterval (1 * mDNSPlatformOneSecond) // For Unicast record registrations, we initialize the interval to 1 second. When we send any query for // the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep // so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done. #define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond) #define MAX_RECORD_REG_INTERVAL (15 * 60 * mDNSPlatformOneSecond) #define MERGE_DELAY_TIME (1 * mDNSPlatformOneSecond) // If we are refreshing, we do it at least 5 times with a min update frequency of // 5 minutes #define MAX_UPDATE_REFRESH_COUNT 5 #define MIN_UPDATE_REFRESH_TIME (5 * 60 * mDNSPlatformOneSecond) // For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers, // then use the default value of 30 seconds #define DEFAULT_UDNS_TIMEOUT 30 // in seconds #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) // Push notification structures struct mDNS_DNSPushNotificationServer { dso_connect_state_t *connectInfo; // DSO Connection state information dso_state_t *connection; // DNS Stateful Operations/TCP Connection pointer, might be null. mDNSu32 numberOfQuestions; // Number of questions for this server DNSPushServer_ConnectState connectState; // Current status of connection attempt to this server mDNSs32 lastDisconnect; // Last time we got a disconnect, used to avoid constant reconnects domainname serverName; // The hostname returned by the _dns-push-tls._tcp. SRV lookup mDNSIPPort port; // The port from the SRV lookup #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_dns_service_t dnsservice; #else DNSServer *qDNSServer; // DNS server stolen from the question that created this server structure. #endif mDNS *m; DNSPushNotificationServer *next; } ; struct mDNS_DNSPushNotificationZone { domainname zoneName; DNSPushNotificationServer *server; // DNS Push Notification Servers for this zone mDNSu32 numberOfQuestions; // Number of questions for this zone DNSPushNotificationZone *next; } ; #endif // Entry points into unicast-specific routines extern void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo); extern void startLLQHandshake(mDNS *m, DNSQuestion *q); extern void sendLLQRefresh(mDNS *m, DNSQuestion *q); #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) extern void DNSPushNotificationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo); extern void DiscoverDNSPushNotificationServer(mDNS *m, DNSQuestion *q); extern DNSPushNotificationServer *GetConnectionToDNSPushNotificationServer(mDNS *m, DNSQuestion *q); extern DNSPushNotificationServer *SubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q); extern void UnSubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q); extern void DNSPushReconcileConnection(mDNS *m, DNSQuestion *q); extern void DNSPushServerDrop(DNSPushNotificationServer *server); #endif extern void SleepRecordRegistrations(mDNS *m); // uDNS_UpdateRecord // following fields must be set, and the update validated, upon entry. // rr->NewRData // rr->newrdlength // rr->UpdateCallback extern mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr); extern void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q); extern mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr); extern mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt); extern mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question); extern mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question); extern mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal); extern void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData); extern mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr); extern const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr); // integer fields of msg header must be in HOST byte order before calling this routine extern void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport); extern void uDNS_Tasks(mDNS *const m); extern void UpdateAllSRVRecords(mDNS *m); extern void CheckNATMappings(mDNS *m); extern mStatus uDNS_SetupDNSConfig(mDNS *const m); // uDNS_SetupWABQueries reads search domains from the platform layer and starts the Wide Area Bonjour // (WAB) domain enumeration queries if necessary. #define UDNS_WAB_BROWSE_QUERY 0x00000001 // Browse queries (b, db) #define UDNS_WAB_LBROWSE_QUERY 0x00000002 // Browse queries (lb) #define UDNS_WAB_REG_QUERY 0x00000004 // Registration queries (r and dr) extern void uDNS_SetupWABQueries(mDNS *const m); extern void uDNS_StartWABQueries(mDNS *const m, int queryType); extern void uDNS_StopWABQueries(mDNS *const m, int queryType); extern domainname *uDNS_GetNextSearchDomain(mDNSInterfaceID InterfaceID, int *searchIndex, mDNSBool ignoreDotLocal); extern void uDNS_RestartQuestionAsTCP(mDNS *m, DNSQuestion *const q, const mDNSAddr *const srcaddr, const mDNSIPPort srcport); typedef enum { uDNS_LLQ_Not = 0, // Normal uDNS answer: Flush any stale records from cache, and respect record TTL uDNS_LLQ_Ignore, // LLQ initial challenge packet: ignore -- has no useful records for us uDNS_LLQ_Entire, // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval uDNS_LLQ_Events // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval } uDNS_LLQType; extern uDNS_LLQType uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion); extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name); extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q); extern void DisposeTCPConn(struct tcpInfo_t *tcp); // NAT traversal extern void uDNS_ReceiveNATPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len); // Called for each received PCP or NAT-PMP packet extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr); extern void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol); #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) // DNS Push Notification extern void SubscribeToDNSPushNotification(mDNS *m, DNSQuestion *q); #endif extern CacheRecord* mDNSCoreReceiveCacheCheck(mDNS *const m, const DNSMessage *const response, uDNS_LLQType LLQType, const mDNSu32 slot, CacheGroup *cg, CacheRecord ***cfp, mDNSInterfaceID InterfaceID); #ifdef __cplusplus } #endif #endif // __UDNS_H /* * Copyright (c) 2003-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. File: daemon.c Contains: main & associated Application layer for mDNSResponder on Linux. */ #if __APPLE__ // In Mac OS X 10.5 and later trying to use the daemon function gives a “‘daemon’ is deprecated” // error, which prevents compilation because we build with "-Werror". // Since this is supposed to be portable cross-platform code, we don't care that daemon is // deprecated on Mac OS X 10.5, so we use this preprocessor trick to eliminate the error message. #define daemon yes_we_know_that_daemon_is_deprecated_in_os_x_10_5_thankyou #endif #include #include #include #include #include #include #include #include #include #include #if __APPLE__ #undef daemon extern int daemon(int, int); #endif #include "mDNSEmbeddedAPI.h" #include "mDNSPosix.h" #include "mDNSUNP.h" // For daemon() #include "uds_daemon.h" #include "PlatformCommon.h" #include "posix_utilities.h" // For getLocalTimestamp() #ifndef MDNSD_USER #define MDNSD_USER "nobody" #endif #define CONFIG_FILE "/etc/mdnsd.conf" static domainname DynDNSZone; // Default wide-area zone for service registration static domainname DynDNSHostname; #define RR_CACHE_SIZE 500 static CacheEntity gRRCache[RR_CACHE_SIZE]; static mDNS_PlatformSupport PlatformStorage; mDNSlocal void mDNS_StatusCallback(mDNS *const m, mStatus result) { (void)m; // Unused if (result == mStatus_NoError) { // On successful registration of dot-local mDNS host name, daemon may want to check if // any name conflict and automatic renaming took place, and if so, record the newly negotiated // name in persistent storage for next time. It should also inform the user of the name change. // On Mac OS X we store the current dot-local mDNS host name in the SCPreferences store, // and notify the user with a CFUserNotification. } else if (result == mStatus_ConfigChanged) { udsserver_handle_configchange(m); } else if (result == mStatus_GrowCache) { // Allocate another chunk of cache storage CacheEntity *storage = malloc(sizeof(CacheEntity) * RR_CACHE_SIZE); if (storage) mDNS_GrowCache(m, storage, RR_CACHE_SIZE); } } // %%% Reconfigure() probably belongs in the platform support layer (mDNSPosix.c), not the daemon cde // -- all client layers running on top of mDNSPosix.c need to handle network configuration changes, // not only the Unix Domain Socket Daemon static void Reconfigure(mDNS *m) { mDNSAddr DynDNSIP; const mDNSAddr dummy = { mDNSAddrType_IPv4, { { { 1, 1, 1, 1 } } } };; mDNS_SetPrimaryInterfaceInfo(m, NULL, NULL, NULL); if (ParseDNSServers(m, uDNS_SERVERS_FILE) < 0) LogMsg("Unable to parse DNS server list. Unicast DNS-SD unavailable"); ReadDDNSSettingsFromConfFile(m, CONFIG_FILE, &DynDNSHostname, &DynDNSZone, NULL); mDNSPlatformSourceAddrForDest(&DynDNSIP, &dummy); if (DynDNSHostname.c[0]) mDNS_AddDynDNSHostName(m, &DynDNSHostname, NULL, NULL); if (DynDNSIP.type) mDNS_SetPrimaryInterfaceInfo(m, &DynDNSIP, NULL, NULL); mDNS_ConfigChanged(m); } // Do appropriate things at startup with command line arguments. Calls exit() if unhappy. mDNSlocal void ParseCmdLinArgs(int argc, char **argv) { if (argc > 1) { if (0 == strcmp(argv[1], "-debug")) mDNS_DebugMode = mDNStrue; else printf("Usage: %s [-debug]\n", argv[0]); } if (!mDNS_DebugMode) { int result = daemon(0, 0); if (result != 0) { LogMsg("Could not run as daemon - exiting"); exit(result); } #if __APPLE__ LogMsg("The POSIX mdnsd should only be used on OS X for testing - exiting"); exit(-1); #endif } } mDNSlocal void ToggleLog(void) { mDNS_LoggingEnabled = !mDNS_LoggingEnabled; } mDNSlocal void ToggleLogPacket(void) { mDNS_PacketLoggingEnabled = !mDNS_PacketLoggingEnabled; } // Dump a little log of what we've been up to. mDNSlocal void DumpStateLog() { char timestamp[64]; // 64 is enough to store the UTC timestmp mDNSu32 major_version = _DNS_SD_H / 10000; mDNSu32 minor_version1 = (_DNS_SD_H - major_version * 10000) / 100; mDNSu32 minor_version2 = _DNS_SD_H % 100; getLocalTimestamp(timestamp, sizeof(timestamp)); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "---- BEGIN STATE LOG ---- (%s mDNSResponder Build %d.%02d.%02d)", timestamp, major_version, minor_version1, minor_version2); udsserver_info_dump_to_fd(STDERR_FILENO); getLocalTimestamp(timestamp, sizeof(timestamp)); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "---- END STATE LOG ---- (%s mDNSResponder Build %d.%02d.%02d)", timestamp, major_version, minor_version1, minor_version2); } mDNSlocal mStatus MainLoop(mDNS *m) // Loop until we quit. { sigset_t signals; mDNSBool gotData = mDNSfalse; mDNSPosixListenForSignalInEventLoop(SIGINT); mDNSPosixListenForSignalInEventLoop(SIGTERM); mDNSPosixListenForSignalInEventLoop(SIGUSR1); mDNSPosixListenForSignalInEventLoop(SIGUSR2); mDNSPosixListenForSignalInEventLoop(SIGINFO); mDNSPosixListenForSignalInEventLoop(SIGPIPE); mDNSPosixListenForSignalInEventLoop(SIGHUP) ; for (; ;) { // Work out how long we expect to sleep before the next scheduled task struct timeval timeout; mDNSs32 ticks; // Only idle if we didn't find any data the last time around if (!gotData) { mDNSs32 nextTimerEvent = mDNS_Execute(m); nextTimerEvent = udsserver_idle(nextTimerEvent); ticks = nextTimerEvent - mDNS_TimeNow(m); if (ticks < 1) ticks = 1; } else // otherwise call EventLoop again with 0 timemout ticks = 0; timeout.tv_sec = ticks / mDNSPlatformOneSecond; timeout.tv_usec = (ticks % mDNSPlatformOneSecond) * 1000000 / mDNSPlatformOneSecond; (void) mDNSPosixRunEventLoopOnce(m, &timeout, &signals, &gotData); if (sigismember(&signals, SIGHUP )) Reconfigure(m); if (sigismember(&signals, SIGINFO)) DumpStateLog(); if (sigismember(&signals, SIGUSR1)) ToggleLog(); if (sigismember(&signals, SIGUSR2)) ToggleLogPacket(); // SIGPIPE happens when we try to write to a dead client; death should be detected soon in request_callback() and cleaned up. if (sigismember(&signals, SIGPIPE)) LogMsg("Received SIGPIPE - ignoring"); if (sigismember(&signals, SIGINT) || sigismember(&signals, SIGTERM)) break; } return EINTR; } int main(int argc, char **argv) { mStatus err; ParseCmdLinArgs(argc, argv); LogInfo("%s starting", mDNSResponderVersionString); err = mDNS_Init(&mDNSStorage, &PlatformStorage, gRRCache, RR_CACHE_SIZE, mDNS_Init_AdvertiseLocalAddresses, mDNS_StatusCallback, mDNS_Init_NoInitCallbackContext); if (mStatus_NoError == err) err = udsserver_init(mDNSNULL, 0); Reconfigure(&mDNSStorage); // Now that we're finished with anything privileged, switch over to running as "nobody" if (mStatus_NoError == err) { const struct passwd *pw = getpwnam(MDNSD_USER); if (pw != NULL) { if (setgid(pw->pw_gid) < 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "WARNING: mdnsd continuing as group root because setgid to \""MDNSD_USER"\" failed with " PUB_S, strerror(errno)); } if (setuid(pw->pw_uid) < 0) { LogMsg("WARNING: mdnsd continuing as root because setuid to \""MDNSD_USER"\" failed with %s", strerror(errno)); } } else { LogMsg("WARNING: mdnsd continuing as root because user \""MDNSD_USER"\" does not exist"); } } if (mStatus_NoError == err) err = MainLoop(&mDNSStorage); LogInfo("%s stopping", mDNSResponderVersionString); mDNS_Close(&mDNSStorage); if (udsserver_exit() < 0) LogMsg("ExitCallback: udsserver_exit failed"); #if MDNS_DEBUGMSGS > 0 printf("mDNSResponder exiting normally with %d\n", err); #endif return err; } // uds_daemon support //////////////////////////////////////////////////////////// mStatus udsSupportAddFDToEventLoop(int fd, udsEventCallback callback, void *context, void **platform_data) /* Support routine for uds_daemon.c */ { // Depends on the fact that udsEventCallback == mDNSPosixEventCallback (void) platform_data; return mDNSPosixAddFDToEventLoop(fd, callback, context); } int udsSupportReadFD(dnssd_sock_t fd, char *buf, int len, int flags, void *platform_data) { (void) platform_data; return recv(fd, buf, len, flags); } mStatus udsSupportRemoveFDFromEventLoop(int fd, void *platform_data) // Note: This also CLOSES the file descriptor { mStatus err = mDNSPosixRemoveFDFromEventLoop(fd); (void) platform_data; close(fd); return err; } mDNSexport void RecordUpdatedNiceLabel(mDNSs32 delay) { (void)delay; // No-op, for now } #if _BUILDING_XCODE_PROJECT_ // If the process crashes, then this string will be magically included in the automatically-generated crash log const char *__crashreporter_info__ = mDNSResponderVersionString_SCCS + 5; asm (".desc ___crashreporter_info__, 0x10"); #endif // For convenience when using the "strings" command, this is the last thing in the file #if defined(mDNSResponderVersion) // Note: The C preprocessor stringify operator ('#') makes a string from its argument, without macro expansion // e.g. If "version" is #define'd to be "4", then STRINGIFY_AWE(version) will return the string "version", not "4" // To expand "version" to its value before making the string, use STRINGIFY(version) instead #define STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) # s #define STRINGIFY(s) STRINGIFY_ARGUMENT_WITHOUT_EXPANSION(s) mDNSexport const char mDNSResponderVersionString_SCCS[] = "@(#) mDNSResponder-" STRINGIFY(mDNSResponderVersion); #elif MDNS_VERSIONSTR_NODTS mDNSexport const char mDNSResponderVersionString_SCCS[] = "@(#) mDNSResponder (Engineering Build)"; #else mDNSexport const char mDNSResponderVersionString_SCCS[] = "@(#) mDNSResponder (Engineering Build) (" __DATE__ " " __TIME__ ")"; #endif /* -*- Mode: C; tab-width: 4; c-file-style: "bsd"; c-basic-offset: 4; fill-column: 108; indent-tabs-mode: nil; -*- * * Copyright (c) 2002-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ #include "mDNSEmbeddedAPI.h" // Defines the interface provided to the client layer above #include "DNSCommon.h" #include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform #include "PlatformCommon.h" #include "dns_sd.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include // platform support for UTC time #include #if USES_NETLINK #include #include #include #else // USES_NETLINK #include #include #endif // USES_NETLINK #include "mDNSUNP.h" #include "GenLinkedList.h" #include "dnsproxy.h" // *************************************************************************** // Structures // Context record for interface change callback struct IfChangeRec { int NotifySD; mDNS *mDNS; }; typedef struct IfChangeRec IfChangeRec; // Note that static data is initialized to zero in (modern) C. static PosixEventSource *gEventSources; // linked list of PosixEventSource's static sigset_t gEventSignalSet; // Signals which event loop listens for static sigset_t gEventSignals; // Signals which were received while inside loop static PosixNetworkInterface *gRecentInterfaces; // *************************************************************************** // Globals (for debugging) static int num_registered_interfaces = 0; static int num_pkts_accepted = 0; static int num_pkts_rejected = 0; // *************************************************************************** // Locals mDNSlocal void requestReadEvents(PosixEventSource *eventSource, const char *taskName, mDNSPosixEventCallback callback, void *context); mDNSlocal mStatus stopReadOrWriteEvents(int fd, mDNSBool freeSource, mDNSBool removeSource, int flags); mDNSlocal void requestWriteEvents(PosixEventSource *eventSource, const char *taskName, mDNSPosixEventCallback callback, void *context); // *************************************************************************** // Functions #if MDNS_MALLOC_DEBUGGING mDNSexport void mDNSPlatformValidateLists(void) { // This should validate gEventSources and any other Posix-specific stuff that gets allocated. } #endif int gMDNSPlatformPosixVerboseLevel = 0; #define PosixErrorToStatus(errNum) ((errNum) == 0 ? mStatus_NoError : mStatus_UnknownErr) mDNSlocal void SockAddrTomDNSAddr(const struct sockaddr *const sa, mDNSAddr *ipAddr, mDNSIPPort *ipPort) { switch (sa->sa_family) { case AF_INET: { struct sockaddr_in *sin = (struct sockaddr_in*)sa; ipAddr->type = mDNSAddrType_IPv4; ipAddr->ip.v4.NotAnInteger = sin->sin_addr.s_addr; if (ipPort) ipPort->NotAnInteger = sin->sin_port; break; } #if HAVE_IPV6 case AF_INET6: { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)sa; #ifndef NOT_HAVE_SA_LEN assert(sin6->sin6_len == sizeof(*sin6)); #endif ipAddr->type = mDNSAddrType_IPv6; ipAddr->ip.v6 = *(mDNSv6Addr*)&sin6->sin6_addr; if (ipPort) ipPort->NotAnInteger = sin6->sin6_port; break; } #endif default: verbosedebugf("SockAddrTomDNSAddr: Uknown address family %d\n", sa->sa_family); ipAddr->type = mDNSAddrType_None; if (ipPort) ipPort->NotAnInteger = 0; break; } } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Send and Receive #endif // mDNS core calls this routine when it needs to send a packet. mDNSexport mStatus mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst, mDNSIPPort dstPort, mDNSBool useBackgroundTrafficClass) { int err = 0; struct sockaddr_storage to; PosixNetworkInterface * thisIntf = (PosixNetworkInterface *)(InterfaceID); int sendingsocket = -1; (void)src; // Will need to use this parameter once we implement mDNSPlatformUDPSocket/mDNSPlatformUDPClose (void) useBackgroundTrafficClass; assert(m != NULL); assert(msg != NULL); assert(end != NULL); assert((((char *) end) - ((char *) msg)) > 0); if (dstPort.NotAnInteger == 0) { LogMsg("mDNSPlatformSendUDP: Invalid argument -dstPort is set to 0"); return PosixErrorToStatus(EINVAL); } if (dst->type == mDNSAddrType_IPv4) { struct sockaddr_in *sin = (struct sockaddr_in*)&to; #ifndef NOT_HAVE_SA_LEN sin->sin_len = sizeof(*sin); #endif sin->sin_family = AF_INET; sin->sin_port = dstPort.NotAnInteger; sin->sin_addr.s_addr = dst->ip.v4.NotAnInteger; sendingsocket = thisIntf ? thisIntf->multicastSocket4 : m->p->unicastSocket4; } #if HAVE_IPV6 else if (dst->type == mDNSAddrType_IPv6) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&to; mDNSPlatformMemZero(sin6, sizeof(*sin6)); #ifndef NOT_HAVE_SA_LEN sin6->sin6_len = sizeof(*sin6); #endif sin6->sin6_family = AF_INET6; sin6->sin6_port = dstPort.NotAnInteger; sin6->sin6_addr = *(struct in6_addr*)&dst->ip.v6; sendingsocket = thisIntf ? thisIntf->multicastSocket6 : m->p->unicastSocket6; } #endif if (sendingsocket >= 0) err = sendto(sendingsocket, msg, (char*)end - (char*)msg, 0, (struct sockaddr *)&to, GET_SA_LEN(to)); if (err > 0) err = 0; else if (err < 0) { static int MessageCount = 0; // Don't report EHOSTDOWN (i.e. ARP failure), ENETDOWN, or no route to host for unicast destinations if (!mDNSAddressIsAllDNSLinkGroup(dst)) if (errno == EHOSTDOWN || errno == ENETDOWN || errno == EHOSTUNREACH || errno == ENETUNREACH) return(mStatus_TransientErr); /* dont report ENETUNREACH */ if (errno == ENETUNREACH) return(mStatus_TransientErr); if (MessageCount < 1000) { MessageCount++; if (thisIntf) LogMsg("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a on interface %#a/%s/%d", errno, strerror(errno), dst, &thisIntf->coreIntf.ip, thisIntf->intfName, thisIntf->index); else LogMsg("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a", errno, strerror(errno), dst); } } return PosixErrorToStatus(err); } mDNSlocal void TCPReadCallback(int fd, void *context) { TCPSocket *sock = context; (void)fd; if (sock->flags & kTCPSocketFlags_UseTLS) { // implement } else { sock->callback(sock, sock->context, mDNSfalse, sock->err); } } mDNSlocal void tcpConnectCallback(int fd, void *context) { TCPSocket *sock = context; mDNSBool c = !sock->connected; int result; socklen_t len = sizeof result; sock->connected = mDNStrue; if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &result, &len) < 0) { LogInfo("ERROR: TCPConnectCallback - unable to get connect error: socket %d: Error %d (%s)", sock->events.fd, result, strerror(result)); sock->err = mStatus_ConnFailed; } else { if (result != 0) { sock->err = mStatus_ConnFailed; if (result == EHOSTUNREACH || result == EADDRNOTAVAIL || result == ENETDOWN) { LogInfo("ERROR: TCPConnectCallback - connect failed: socket %d: Error %d (%s)", sock->events.fd, result, strerror(result)); } else { LogMsg("ERROR: TCPConnectCallback - connect failed: socket %d: Error %d (%s)", sock->events.fd, result, strerror(result)); } } else { // The connection succeeded. sock->connected = mDNStrue; // Select for read events. sock->events.fd = fd; requestReadEvents(&sock->events, "mDNSPosix::tcpConnectCallback", TCPReadCallback, sock); } } if (sock->callback) { sock->callback(sock, sock->context, c, sock->err); // Here sock must be assumed to be invalid, in case the callback freed it. return; } } // This routine is called when the main loop detects that data is available on a socket. mDNSlocal void SocketDataReady(mDNS *const m, PosixNetworkInterface *intf, int skt) { mDNSAddr senderAddr, destAddr; mDNSIPPort senderPort; ssize_t packetLen; DNSMessage packet; struct my_in_pktinfo packetInfo; struct sockaddr_storage from; socklen_t fromLen; int flags; mDNSu8 ttl; mDNSBool reject; const mDNSInterfaceID InterfaceID = intf ? intf->coreIntf.InterfaceID : NULL; assert(m != NULL); assert(skt >= 0); fromLen = sizeof(from); flags = 0; packetLen = recvfrom_flags(skt, &packet, sizeof(packet), &flags, (struct sockaddr *) &from, &fromLen, &packetInfo, &ttl); if (packetLen >= 0) { SockAddrTomDNSAddr((struct sockaddr*)&from, &senderAddr, &senderPort); SockAddrTomDNSAddr((struct sockaddr*)&packetInfo.ipi_addr, &destAddr, NULL); // If we have broken IP_RECVDSTADDR functionality (so far // I've only seen this on OpenBSD) then apply a hack to // convince mDNS Core that this isn't a spoof packet. // Basically what we do is check to see whether the // packet arrived as a multicast and, if so, set its // destAddr to the mDNS address. // // I must admit that I could just be doing something // wrong on OpenBSD and hence triggering this problem // but I'm at a loss as to how. // // If this platform doesn't have IP_PKTINFO or IP_RECVDSTADDR, then we have // no way to tell the destination address or interface this packet arrived on, // so all we can do is just assume it's a multicast #if HAVE_BROKEN_RECVDSTADDR || (!defined(IP_PKTINFO) && !defined(IP_RECVDSTADDR)) if ((destAddr.NotAnInteger == 0) && (flags & MSG_MCAST)) { destAddr.type = senderAddr.type; if (senderAddr.type == mDNSAddrType_IPv4) destAddr.ip.v4 = AllDNSLinkGroup_v4.ip.v4; else if (senderAddr.type == mDNSAddrType_IPv6) destAddr.ip.v6 = AllDNSLinkGroup_v6.ip.v6; } #endif // We only accept the packet if the interface on which it came // in matches the interface associated with this socket. // We do this match by name or by index, depending on which // information is available. recvfrom_flags sets the name // to "" if the name isn't available, or the index to -1 // if the index is available. This accomodates the various // different capabilities of our target platforms. reject = mDNSfalse; if (!intf) { // Ignore multicasts accidentally delivered to our unicast receiving socket if (mDNSAddrIsDNSMulticast(&destAddr)) packetLen = -1; } else { if (packetInfo.ipi_ifname[0] != 0) reject = (strcmp(packetInfo.ipi_ifname, intf->intfName) != 0); else if (packetInfo.ipi_ifindex != -1) reject = (packetInfo.ipi_ifindex != intf->index); if (reject) { verbosedebugf("SocketDataReady ignored a packet from %#a to %#a on interface %s/%d expecting %#a/%s/%d/%d", &senderAddr, &destAddr, packetInfo.ipi_ifname, packetInfo.ipi_ifindex, &intf->coreIntf.ip, intf->intfName, intf->index, skt); packetLen = -1; num_pkts_rejected++; if (num_pkts_rejected > (num_pkts_accepted + 1) * (num_registered_interfaces + 1) * 2) { fprintf(stderr, "*** WARNING: Received %d packets; Accepted %d packets; Rejected %d packets because of interface mismatch\n", num_pkts_accepted + num_pkts_rejected, num_pkts_accepted, num_pkts_rejected); num_pkts_accepted = 0; num_pkts_rejected = 0; } } else { verbosedebugf("SocketDataReady got a packet from %#a to %#a on interface %#a/%s/%d/%d", &senderAddr, &destAddr, &intf->coreIntf.ip, intf->intfName, intf->index, skt); num_pkts_accepted++; } } } if (packetLen >= 0) mDNSCoreReceive(m, &packet, (mDNSu8 *)&packet + packetLen, &senderAddr, senderPort, &destAddr, MulticastDNSPort, InterfaceID); } mDNSexport TCPSocket *mDNSPlatformTCPSocket(TCPSocketFlags flags, mDNSAddr_Type addrType, mDNSIPPort * port, domainname *hostname, mDNSBool useBackgroundTrafficClass) { TCPSocket *sock; int len = sizeof (TCPSocket); (void)useBackgroundTrafficClass; if (hostname) { len += sizeof (domainname); } sock = malloc(len); if (sock == NULL) { LogMsg("mDNSPlatformTCPSocket: no memory for socket"); return NULL; } memset(sock, 0, sizeof *sock); if (hostname) { sock->hostname = (domainname *)(sock + 1); LogMsg("mDNSPlatformTCPSocket: hostname %##s", hostname->c); AssignDomainName(sock->hostname, hostname); } sock->events.fd = -1; if (!mDNSPosixTCPSocketSetup(&sock->events.fd, addrType, port, &sock->port)) { if (sock->events.fd != -1) close(sock->events.fd); free(sock); return mDNSNULL; } // Set up the other fields in the structure. sock->flags = flags; sock->err = mStatus_NoError; sock->setup = mDNSfalse; sock->connected = mDNSfalse; return sock; } mDNSexport mStatus mDNSPlatformTCPSocketSetCallback(TCPSocket *sock, TCPConnectionCallback callback, void *context) { sock->callback = callback; sock->context = context; return mStatus_NoError; } mDNSexport TCPSocket *mDNSPlatformTCPAccept(TCPSocketFlags flags, int fd) { TCPSocket *sock; // XXX Add! if (flags & kTCPSocketFlags_UseTLS) { return mDNSNULL; // not supported yet. } sock = (TCPSocket *) mDNSPlatformMemAllocateClear(sizeof *sock); if (!sock) { return mDNSNULL; } sock->events.fd = fd; sock->flags = flags; sock->connected = mDNStrue; return sock; } mDNSlocal void tcpListenCallback(int fd, void *context) { TCPListener *listener = context; TCPSocket *sock; sock = mDNSPosixDoTCPListenCallback(fd, listener->addressType, listener->socketFlags, listener->callback, listener->context); if (sock != NULL) { requestReadEvents(&sock->events, "mDNSPosix::tcpListenCallback", TCPReadCallback, sock); } } mDNSexport TCPListener *mDNSPlatformTCPListen(mDNSAddr_Type addrType, mDNSIPPort *port, mDNSAddr *addr, TCPSocketFlags socketFlags, mDNSBool reuseAddr, int queueLength, TCPAcceptedCallback callback, void *context) { TCPListener *ret; int fd = -1; if (!mDNSPosixTCPListen(&fd, addrType, port, addr, reuseAddr, queueLength)) { if (fd != -1) { close(fd); } return mDNSNULL; } // Allocate a listener structure ret = (TCPListener *) mDNSPlatformMemAllocateClear(sizeof *ret); if (ret == NULL) { LogMsg("mDNSPlatformTCPListen: no memory for TCPListener struct."); close(fd); return mDNSNULL; } ret->events.fd = fd; ret->callback = callback; ret->context = context; ret->addressType = addrType; ret->socketFlags = socketFlags; // When we get a connection, mDNSPosixListenCallback will be called, and it will invoke the // callback we were passed. requestReadEvents(&ret->events, "tcpListenCallback", tcpListenCallback, ret); return ret; } mDNSexport int mDNSPlatformTCPGetFD(TCPSocket *sock) { return sock->events.fd; } mDNSexport mStatus mDNSPlatformTCPConnect(TCPSocket *sock, const mDNSAddr *dst, mDNSOpaque16 dstport, mDNSInterfaceID InterfaceID, TCPConnectionCallback callback, void *context) { int result; union { struct sockaddr sa; struct sockaddr_in sin; struct sockaddr_in6 sin6; } addr; socklen_t len; sock->callback = callback; sock->context = context; sock->setup = mDNSfalse; sock->connected = mDNSfalse; sock->err = mStatus_NoError; result = fcntl(sock->events.fd, F_GETFL, 0); if (result < 0) { LogMsg("mDNSPlatformTCPConnect: F_GETFL failed: %s", strerror(errno)); return mStatus_UnknownErr; } result = fcntl(sock->events.fd, F_SETFL, result | O_NONBLOCK); if (result < 0) { LogMsg("mDNSPlatformTCPConnect: F_SETFL failed: %s", strerror(errno)); return mStatus_UnknownErr; } // If we've been asked to bind to a single interface, do it. See comment in mDNSMacOSX.c for more info. if (InterfaceID) { PosixNetworkInterface *iface = (PosixNetworkInterface *)InterfaceID; #if defined(SO_BINDTODEVICE) result = setsockopt(sock->events.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->intfName, strlen(iface->intfName)); if (result < 0) { LogMsg("mDNSPlatformTCPConnect: SO_BINDTODEVICE failed on %s: %s", iface->intfName, strerror(errno)); return mStatus_BadParamErr; } #else if (dst->type == mDNSAddrType_IPv4) { #if defined(IP_BOUND_IF) result = setsockopt(sock->events.fd, IPPROTO_IP, IP_BOUND_IF, &iface->index, sizeof iface->index); if (result < 0) { LogMsg("mDNSPlatformTCPConnect: IP_BOUND_IF failed on %s (%d): %s", iface->intfName, iface->index, strerror(errno)); return mStatus_BadParamErr; } #else (void)iface; #endif // IP_BOUND_IF } else { // IPv6 #if defined(IPV6_BOUND_IF) result = setsockopt(sock->events.fd, IPPROTO_IPV6, IPV6_BOUND_IF, &iface->index, sizeof iface->index); if (result < 0) { LogMsg("mDNSPlatformTCPConnect: IP_BOUND_IF failed on %s (%d): %s", iface->intfName, iface->index, strerror(errno)); return mStatus_BadParamErr; } #else (void)iface; #endif // IPV6_BOUND_IF } #endif // SO_BINDTODEVICE } memset(&addr, 0, sizeof addr); if (dst->type == mDNSAddrType_IPv4) { addr.sa.sa_family = AF_INET; addr.sin.sin_port = dstport.NotAnInteger; len = sizeof (struct sockaddr_in); addr.sin.sin_addr.s_addr = dst->ip.v4.NotAnInteger; } else { addr.sa.sa_family = AF_INET6; len = sizeof (struct sockaddr_in6); addr.sin6.sin6_port = dstport.NotAnInteger; memcpy(&addr.sin6.sin6_addr.s6_addr, &dst->ip.v6, sizeof addr.sin6.sin6_addr.s6_addr); } #ifndef NOT_HAVE_SA_LEN addr.sa.sa_len = len; #endif result = connect(sock->events.fd, (struct sockaddr *)&addr, len); if (result < 0) { if (errno == EINPROGRESS) { requestWriteEvents(&sock->events, "mDNSPlatformConnect", tcpConnectCallback, sock); return mStatus_ConnPending; } if (errno == EHOSTUNREACH || errno == EADDRNOTAVAIL || errno == ENETDOWN) { LogInfo("ERROR: mDNSPlatformTCPConnect - connect failed: socket %d: Error %d (%s)", sock->events.fd, errno, strerror(errno)); } else { LogMsg("ERROR: mDNSPlatformTCPConnect - connect failed: socket %d: Error %d (%s) length %d", sock->events.fd, errno, strerror(errno), len); } return mStatus_ConnFailed; } LogMsg("NOTE: mDNSPlatformTCPConnect completed synchronously"); return mStatus_NoError; } mDNSexport void mDNSPlatformTCPCloseConnection(TCPSocket *sock) { if (sock) { // can sock really be NULL when this is called? shutdown(sock->events.fd, SHUT_RDWR); stopReadOrWriteEvents(sock->events.fd, mDNSfalse, mDNStrue, PosixEventFlag_Read | PosixEventFlag_Write); close(sock->events.fd); free(sock); } } mDNSexport long mDNSPlatformReadTCP(TCPSocket *sock, void *buf, unsigned long buflen, mDNSBool * closed) { ssize_t nread; *closed = mDNSfalse; if (sock->flags & kTCPSocketFlags_UseTLS) { // Implement... nread = -1; *closed = mDNStrue; } else { nread = mDNSPosixReadTCP(sock->events.fd, buf, buflen, closed); } return nread; } mDNSexport mDNSBool mDNSPlatformTCPWritable(TCPSocket *sock) { fd_set w = { 0 }; int nfds = sock->events.fd + 1; int count; struct timeval tv; if (nfds > FD_SETSIZE) { LogMsg("ERROR: mDNSPlatformTCPWritable called on an fd that won't fit in an fd_set."); return mDNStrue; // hope for the best? } FD_SET(sock->events.fd, &w); tv.tv_sec = tv.tv_usec = 0; count = select(nfds, NULL, &w, NULL, &tv); if (count > 0) { return mDNStrue; } return mDNSfalse; } mDNSexport long mDNSPlatformWriteTCP(TCPSocket *sock, const char *msg, unsigned long len) { if (sock->flags & kTCPSocketFlags_UseTLS) { // implement return -1; } else { return mDNSPosixWriteTCP(sock->events.fd, msg, len); } } mDNSexport UDPSocket *mDNSPlatformUDPSocket(mDNSIPPort port) { (void)port; // Unused return NULL; } mDNSexport void mDNSPlatformUDPClose(UDPSocket *sock) { (void)sock; // Unused } mDNSexport void mDNSPlatformUpdateProxyList(const mDNSInterfaceID InterfaceID) { (void)InterfaceID; // Unused } mDNSexport void mDNSPlatformSendRawPacket(const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID) { (void)msg; // Unused (void)end; // Unused (void)InterfaceID; // Unused } mDNSexport void mDNSPlatformSetLocalAddressCacheEntry(const mDNSAddr *const tpa, const mDNSEthAddr *const tha, mDNSInterfaceID InterfaceID) { (void)tpa; // Unused (void)tha; // Unused (void)InterfaceID; // Unused } mDNSexport mStatus mDNSPlatformTLSSetupCerts(void) { return(mStatus_UnsupportedErr); } mDNSexport void mDNSPlatformTLSTearDownCerts(void) { } mDNSexport void mDNSPlatformSetAllowSleep(mDNSBool allowSleep, const char *reason) { (void) allowSleep; (void) reason; } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - /etc/hosts support #endif mDNSexport void FreeEtcHosts(mDNS *const m, AuthRecord *const rr, mStatus result) { (void)m; // unused (void)rr; (void)result; } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** DDNS Config Platform Functions #endif mDNSexport mDNSBool mDNSPlatformSetDNSConfig(mDNSBool setservers, mDNSBool setsearch, domainname *const fqdn, DNameListElem **RegDomains, DNameListElem **BrowseDomains, mDNSBool ackConfig) { (void) setservers; (void) setsearch; (void) ackConfig; if (fqdn ) fqdn->c[0] = 0; if (RegDomains ) *RegDomains = NULL; if (BrowseDomains) *BrowseDomains = NULL; return mDNStrue; } mDNSexport mStatus mDNSPlatformGetPrimaryInterface(mDNSAddr * v4, mDNSAddr * v6, mDNSAddr * router) { (void) v4; (void) v6; (void) router; return mStatus_UnsupportedErr; } mDNSexport void mDNSPlatformDynDNSHostNameStatusChanged(const domainname *const dname, const mStatus status) { (void) dname; (void) status; } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Init and Term #endif // This gets the current hostname, truncating it at the first dot if necessary mDNSlocal void GetUserSpecifiedRFC1034ComputerName(domainlabel *const namelabel) { int len = 0; gethostname((char *)(&namelabel->c[1]), MAX_DOMAIN_LABEL); while (len < MAX_DOMAIN_LABEL && namelabel->c[len+1] && namelabel->c[len+1] != '.') len++; namelabel->c[0] = len; } // On OS X this gets the text of the field labelled "Computer Name" in the Sharing Prefs Control Panel // Other platforms can either get the information from the appropriate place, // or they can alternatively just require all registering services to provide an explicit name mDNSlocal void GetUserSpecifiedFriendlyComputerName(domainlabel *const namelabel) { // On Unix we have no better name than the host name, so we just use that. GetUserSpecifiedRFC1034ComputerName(namelabel); } mDNSexport int ParseDNSServers(mDNS *m, const char *filePath) { char line[256]; char nameserver[16]; char keyword[11]; int numOfServers = 0; FILE *fp = fopen(filePath, "r"); if (fp == NULL) return -1; while (fgets(line,sizeof(line),fp)) { struct in_addr ina; line[255]='\0'; // just to be safe if (sscanf(line,"%10s %15s", keyword, nameserver) != 2) continue; // it will skip whitespaces if (strncasecmp(keyword,"nameserver",10)) continue; if (inet_aton(nameserver, (struct in_addr *)&ina) != 0) { mDNSAddr DNSAddr; DNSAddr.type = mDNSAddrType_IPv4; DNSAddr.ip.v4.NotAnInteger = ina.s_addr; mDNS_AddDNSServer(m, NULL, mDNSInterface_Any, 0, &DNSAddr, UnicastDNSPort, kScopeNone, 0, mDNSfalse, mDNSfalse, mDNSfalse, mDNSfalse, 0, mDNStrue, mDNStrue, mDNSfalse); numOfServers++; } } fclose(fp); return (numOfServers > 0) ? 0 : -1; } // Searches the interface list looking for the named interface. // Returns a pointer to if it found, or NULL otherwise. mDNSlocal PosixNetworkInterface *SearchForInterfaceByName(mDNS *const m, const char *intfName) { PosixNetworkInterface *intf; assert(m != NULL); assert(intfName != NULL); intf = (PosixNetworkInterface*)(m->HostInterfaces); while ((intf != NULL) && (strcmp(intf->intfName, intfName) != 0)) intf = (PosixNetworkInterface *)(intf->coreIntf.next); return intf; } mDNSexport mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 index) { PosixNetworkInterface *intf; assert(m != NULL); if (index == kDNSServiceInterfaceIndexLocalOnly) return(mDNSInterface_LocalOnly); if (index == kDNSServiceInterfaceIndexP2P ) return(mDNSInterface_P2P); if (index == kDNSServiceInterfaceIndexAny ) return(mDNSInterface_Any); intf = (PosixNetworkInterface*)(m->HostInterfaces); while ((intf != NULL) && (mDNSu32) intf->index != index) intf = (PosixNetworkInterface *)(intf->coreIntf.next); return (mDNSInterfaceID) intf; } mDNSexport mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id, mDNSBool suppressNetworkChange) { PosixNetworkInterface *intf; (void) suppressNetworkChange; // Unused assert(m != NULL); if (id == mDNSInterface_LocalOnly) return(kDNSServiceInterfaceIndexLocalOnly); if (id == mDNSInterface_P2P ) return(kDNSServiceInterfaceIndexP2P); if (id == mDNSInterface_Any ) return(kDNSServiceInterfaceIndexAny); intf = (PosixNetworkInterface*)(m->HostInterfaces); while ((intf != NULL) && (mDNSInterfaceID) intf != id) intf = (PosixNetworkInterface *)(intf->coreIntf.next); if (intf) return intf->index; // If we didn't find the interface, check the RecentInterfaces list as well intf = gRecentInterfaces; while ((intf != NULL) && (mDNSInterfaceID) intf != id) intf = (PosixNetworkInterface *)(intf->coreIntf.next); return intf ? intf->index : 0; } // Frees the specified PosixNetworkInterface structure. The underlying // interface must have already been deregistered with the mDNS core. mDNSlocal void FreePosixNetworkInterface(PosixNetworkInterface *intf) { int rv; assert(intf != NULL); if (intf->intfName != NULL) free((void *)intf->intfName); if (intf->multicastSocket4 != -1) { rv = close(intf->multicastSocket4); assert(rv == 0); } #if HAVE_IPV6 if (intf->multicastSocket6 != -1) { rv = close(intf->multicastSocket6); assert(rv == 0); } #endif // Move interface to the RecentInterfaces list for a minute intf->LastSeen = mDNSPlatformUTC(); intf->coreIntf.next = &gRecentInterfaces->coreIntf; gRecentInterfaces = intf; } // Grab the first interface, deregister it, free it, and repeat until done. mDNSlocal void ClearInterfaceList(mDNS *const m) { assert(m != NULL); while (m->HostInterfaces) { PosixNetworkInterface *intf = (PosixNetworkInterface*)(m->HostInterfaces); mDNS_DeregisterInterface(m, &intf->coreIntf, NormalActivation); if (gMDNSPlatformPosixVerboseLevel > 0) fprintf(stderr, "Deregistered interface %s\n", intf->intfName); FreePosixNetworkInterface(intf); } num_registered_interfaces = 0; num_pkts_accepted = 0; num_pkts_rejected = 0; } // Sets up a send/receive socket. // If mDNSIPPort port is non-zero, then it's a multicast socket on the specified interface // If mDNSIPPort port is zero, then it's a randomly assigned port number, used for sending unicast queries mDNSlocal int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interfaceIndex, int *sktPtr) { int err = 0; static const int kOn = 1; static const int kIntTwoFiveFive = 255; static const unsigned char kByteTwoFiveFive = 255; const mDNSBool JoinMulticastGroup = (port.NotAnInteger != 0); (void) interfaceIndex; // This parameter unused on plaforms that don't have IPv6 assert(intfAddr != NULL); assert(sktPtr != NULL); assert(*sktPtr == -1); // Open the socket... if (intfAddr->sa_family == AF_INET) *sktPtr = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); #if HAVE_IPV6 else if (intfAddr->sa_family == AF_INET6) *sktPtr = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP); #endif else return EINVAL; if (*sktPtr < 0) { err = errno; perror((intfAddr->sa_family == AF_INET) ? "socket AF_INET" : "socket AF_INET6"); } // ... with a shared UDP port, if it's for multicast receiving if (err == 0 && port.NotAnInteger) { // Suggestions from Jonny Törnbom at Axis Communications // We test for SO_REUSEADDR first, as suggested by Jonny Törnbom from Axis Communications // Linux kernel versions 3.9 introduces support for socket option // SO_REUSEPORT, however this is not implemented the same as on *BSD // systems. Linux version implements a "port hijacking" prevention // mechanism, limiting processes wanting to bind to an already existing // addr:port to have the same effective UID as the first who bound it. What // this meant for us was that the daemon ran as one user and when for // instance mDNSClientPosix was executed by another user, it wasn't allowed // to bind to the socket. Our suggestion was to switch the order in which // SO_REUSEPORT and SO_REUSEADDR was tested so that SO_REUSEADDR stays on // top and SO_REUSEPORT to be used only if SO_REUSEADDR doesn't exist. #if defined(SO_REUSEADDR) && !defined(__MAC_OS_X_VERSION_MIN_REQUIRED) err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEADDR, &kOn, sizeof(kOn)); #elif defined(SO_REUSEPORT) err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEPORT, &kOn, sizeof(kOn)); #else #error This platform has no way to avoid address busy errors on multicast. #endif if (err < 0) { err = errno; perror("setsockopt - SO_REUSExxxx"); } #if TARGET_OS_MAC // Enable inbound packets on IFEF_AWDL interface. // Only done for multicast sockets, since we don't expect unicast socket operations // on the IFEF_AWDL interface. Operation is a no-op for other interface types. #ifndef SO_RECV_ANYIF #define SO_RECV_ANYIF 0x1104 /* unrestricted inbound processing */ #endif if (setsockopt(*sktPtr, SOL_SOCKET, SO_RECV_ANYIF, &kOn, sizeof(kOn)) < 0) perror("setsockopt - SO_RECV_ANYIF"); #endif } // We want to receive destination addresses and interface identifiers. if (intfAddr->sa_family == AF_INET) { struct ip_mreq imr; struct sockaddr_in bindAddr; if (err == 0) { #if defined(IP_PKTINFO) // Linux err = setsockopt(*sktPtr, IPPROTO_IP, IP_PKTINFO, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IP_PKTINFO"); } #elif defined(IP_RECVDSTADDR) || defined(IP_RECVIF) // BSD and Solaris #if defined(IP_RECVDSTADDR) err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVDSTADDR, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IP_RECVDSTADDR"); } #endif #if defined(IP_RECVIF) if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVIF, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IP_RECVIF"); } } #endif #else #warning This platform has no way to get the destination interface information -- will only work for single-homed hosts #endif } #if defined(IP_RECVTTL) // Linux if (err == 0) { setsockopt(*sktPtr, IPPROTO_IP, IP_RECVTTL, &kOn, sizeof(kOn)); // We no longer depend on being able to get the received TTL, so don't worry if the option fails } #endif // Add multicast group membership on this interface if (err == 0 && JoinMulticastGroup) { imr.imr_multiaddr.s_addr = AllDNSLinkGroup_v4.ip.v4.NotAnInteger; imr.imr_interface = ((struct sockaddr_in*)intfAddr)->sin_addr; err = setsockopt(*sktPtr, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr, sizeof(imr)); if (err < 0) { err = errno; perror("setsockopt - IP_ADD_MEMBERSHIP"); } } // Specify outgoing interface too if (err == 0 && JoinMulticastGroup) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_IF, &((struct sockaddr_in*)intfAddr)->sin_addr, sizeof(struct in_addr)); if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_IF"); } } // Per the mDNS spec, send unicast packets with TTL 255 if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IP_TTL"); } } // and multicast packets with TTL 255 too // There's some debate as to whether IP_MULTICAST_TTL is an int or a byte so we just try both. if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive)); if (err < 0 && errno == EINVAL) err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_TTL"); } } // And start listening for packets if (err == 0) { bindAddr.sin_family = AF_INET; bindAddr.sin_port = port.NotAnInteger; bindAddr.sin_addr.s_addr = INADDR_ANY; // Want to receive multicasts AND unicasts on this socket err = bind(*sktPtr, (struct sockaddr *) &bindAddr, sizeof(bindAddr)); if (err < 0) { err = errno; perror("bind"); fflush(stderr); } } } // endif (intfAddr->sa_family == AF_INET) #if HAVE_IPV6 else if (intfAddr->sa_family == AF_INET6) { struct ipv6_mreq imr6; struct sockaddr_in6 bindAddr6; #if defined(IPV6_RECVPKTINFO) // Solaris if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_RECVPKTINFO, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_RECVPKTINFO"); } } #elif defined(IPV6_PKTINFO) if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_2292_PKTINFO, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_PKTINFO"); } } #else #warning This platform has no way to get the destination interface information for IPv6 -- will only work for single-homed hosts #endif #if defined(IPV6_RECVHOPLIMIT) if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_RECVHOPLIMIT"); } } #elif defined(IPV6_HOPLIMIT) if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_2292_HOPLIMIT, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_HOPLIMIT"); } } #endif // Add multicast group membership on this interface if (err == 0 && JoinMulticastGroup) { imr6.ipv6mr_multiaddr = *(const struct in6_addr*)&AllDNSLinkGroup_v6.ip.v6; imr6.ipv6mr_interface = interfaceIndex; //LogMsg("Joining %.16a on %d", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface); err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_JOIN_GROUP, &imr6, sizeof(imr6)); if (err < 0) { err = errno; verbosedebugf("IPV6_JOIN_GROUP %.16a on %d failed.\n", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface); perror("setsockopt - IPV6_JOIN_GROUP"); } } // Specify outgoing interface too if (err == 0 && JoinMulticastGroup) { u_int multicast_if = interfaceIndex; err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_IF, &multicast_if, sizeof(multicast_if)); if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_IF"); } } // We want to receive only IPv6 packets on this socket. // Without this option, we may get IPv4 addresses as mapped addresses. if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_V6ONLY, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_V6ONLY"); } } // Per the mDNS spec, send unicast packets with TTL 255 if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IPV6_UNICAST_HOPS"); } } // and multicast packets with TTL 255 too // There's some debate as to whether IPV6_MULTICAST_HOPS is an int or a byte so we just try both. if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive)); if (err < 0 && errno == EINVAL) err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_HOPS"); } } // And start listening for packets if (err == 0) { mDNSPlatformMemZero(&bindAddr6, sizeof(bindAddr6)); #ifndef NOT_HAVE_SA_LEN bindAddr6.sin6_len = sizeof(bindAddr6); #endif bindAddr6.sin6_family = AF_INET6; bindAddr6.sin6_port = port.NotAnInteger; bindAddr6.sin6_flowinfo = 0; bindAddr6.sin6_addr = in6addr_any; // Want to receive multicasts AND unicasts on this socket bindAddr6.sin6_scope_id = 0; err = bind(*sktPtr, (struct sockaddr *) &bindAddr6, sizeof(bindAddr6)); if (err < 0) { err = errno; perror("bind"); fflush(stderr); } } } // endif (intfAddr->sa_family == AF_INET6) #endif // Set the socket to non-blocking. if (err == 0) { err = fcntl(*sktPtr, F_GETFL, 0); if (err < 0) err = errno; else { err = fcntl(*sktPtr, F_SETFL, err | O_NONBLOCK); if (err < 0) err = errno; } } // Clean up if (err != 0 && *sktPtr != -1) { int rv; rv = close(*sktPtr); assert(rv == 0); *sktPtr = -1; } assert((err == 0) == (*sktPtr != -1)); return err; } // Creates a PosixNetworkInterface for the interface whose IP address is // intfAddr and whose name is intfName and registers it with mDNS core. mDNSlocal int SetupOneInterface(mDNS *const m, struct sockaddr *intfAddr, struct sockaddr *intfMask, const char *intfName, int intfIndex) { int err = 0; PosixNetworkInterface *intf; PosixNetworkInterface *alias = NULL; assert(m != NULL); assert(intfAddr != NULL); assert(intfName != NULL); assert(intfMask != NULL); // Allocate the interface structure itself. intf = (PosixNetworkInterface*)calloc(1, sizeof(*intf)); if (intf == NULL) { assert(0); err = ENOMEM; } // And make a copy of the intfName. if (err == 0) { #ifdef LINUX char *s; int len; s = strchr(intfName, ':'); if (s != NULL) { len = (s - intfName) + 1; } else { len = strlen(intfName) + 1; } intf->intfName = malloc(len); if (intf->intfName == NULL) { assert(0); err = ENOMEM; } memcpy(intf->intfName, intfName, len - 1); intfName[len - 1] = 0; #else intf->intfName = strdup(intfName); if (intf->intfName == NULL) { assert(0); err = ENOMEM; } #endif } if (err == 0) { // Set up the fields required by the mDNS core. SockAddrTomDNSAddr(intfAddr, &intf->coreIntf.ip, NULL); SockAddrTomDNSAddr(intfMask, &intf->coreIntf.mask, NULL); //LogMsg("SetupOneInterface: %#a %#a", &intf->coreIntf.ip, &intf->coreIntf.mask); strncpy(intf->coreIntf.ifname, intfName, sizeof(intf->coreIntf.ifname)); intf->coreIntf.ifname[sizeof(intf->coreIntf.ifname)-1] = 0; intf->coreIntf.Advertise = m->AdvertiseLocalAddresses; intf->coreIntf.McastTxRx = mDNStrue; // Set up the extra fields in PosixNetworkInterface. assert(intf->intfName != NULL); // intf->intfName already set up above intf->index = intfIndex; intf->multicastSocket4 = -1; #if HAVE_IPV6 intf->multicastSocket6 = -1; #endif alias = SearchForInterfaceByName(m, intf->intfName); if (alias == NULL) alias = intf; intf->coreIntf.InterfaceID = (mDNSInterfaceID)alias; if (alias != intf) debugf("SetupOneInterface: %s %#a is an alias of %#a", intfName, &intf->coreIntf.ip, &alias->coreIntf.ip); } // Set up the multicast socket if (err == 0) { if (alias->multicastSocket4 == -1 && intfAddr->sa_family == AF_INET) err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket4); #if HAVE_IPV6 else if (alias->multicastSocket6 == -1 && intfAddr->sa_family == AF_INET6) err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket6); #endif } // If interface is a direct link, address record will be marked as kDNSRecordTypeKnownUnique // and skip the probe phase of the probe/announce packet sequence. intf->coreIntf.DirectLink = mDNSfalse; #ifdef DIRECTLINK_INTERFACE_NAME if (strcmp(intfName, STRINGIFY(DIRECTLINK_INTERFACE_NAME)) == 0) intf->coreIntf.DirectLink = mDNStrue; #endif intf->coreIntf.SupportsUnicastMDNSResponse = mDNStrue; // The interface is all ready to go, let's register it with the mDNS core. if (err == 0) err = mDNS_RegisterInterface(m, &intf->coreIntf, NormalActivation); // Clean up. if (err == 0) { num_registered_interfaces++; debugf("SetupOneInterface: %s %#a Registered", intf->intfName, &intf->coreIntf.ip); if (gMDNSPlatformPosixVerboseLevel > 0) fprintf(stderr, "Registered interface %s\n", intf->intfName); } else { // Use intfName instead of intf->intfName in the next line to avoid dereferencing NULL. debugf("SetupOneInterface: %s %#a failed to register %d", intfName, &intf->coreIntf.ip, err); if (intf) { FreePosixNetworkInterface(intf); intf = NULL; } } assert((err == 0) == (intf != NULL)); return err; } // Call get_ifi_info() to obtain a list of active interfaces and call SetupOneInterface() on each one. mDNSlocal int SetupInterfaceList(mDNS *const m) { mDNSBool foundav4 = mDNSfalse; int err = 0; struct ifaddrs *intfList; struct ifaddrs *firstLoopback = NULL; int firstLoopbackIndex = 0; assert(m != NULL); debugf("SetupInterfaceList"); if (getifaddrs(&intfList) < 0) { err = errno; } if (intfList == NULL) err = ENOENT; if (err == 0) { struct ifaddrs *i = intfList; while (i) { if ( i->ifa_addr != NULL && ((i->ifa_addr->sa_family == AF_INET) #if HAVE_IPV6 || (i->ifa_addr->sa_family == AF_INET6) #endif ) && (i->ifa_flags & IFF_UP) && !(i->ifa_flags & IFF_POINTOPOINT)) { int ifIndex = if_nametoindex(i->ifa_name); if (ifIndex == 0) { i = i->ifa_next; continue; } if (i->ifa_flags & IFF_LOOPBACK) { if (firstLoopback == NULL) { firstLoopback = i; firstLoopbackIndex = ifIndex; } } else { if (SetupOneInterface(m, i->ifa_addr, i->ifa_netmask, i->ifa_name, ifIndex) == 0) { if (i->ifa_addr->sa_family == AF_INET) { foundav4 = mDNStrue; } } } } i = i->ifa_next; } // If we found no normal interfaces but we did find a loopback interface, register the // loopback interface. This allows self-discovery if no interfaces are configured. // Temporary workaround: Multicast loopback on IPv6 interfaces appears not to work. // In the interim, we skip loopback interface only if we found at least one v4 interface to use // if ((m->HostInterfaces == NULL) && (firstLoopback != NULL)) if (!foundav4 && firstLoopback) { (void)SetupOneInterface(m, firstLoopback->ifa_addr, firstLoopback->ifa_netmask, firstLoopback->ifa_name, firstLoopbackIndex); } } // Clean up. if (intfList != NULL) freeifaddrs(intfList); // Clean up any interfaces that have been hanging around on the RecentInterfaces list for more than a minute PosixNetworkInterface **ri = &gRecentInterfaces; const mDNSs32 utc = mDNSPlatformUTC(); while (*ri) { PosixNetworkInterface *pi = *ri; if (utc - pi->LastSeen < 60) ri = (PosixNetworkInterface **)&pi->coreIntf.next; else { *ri = (PosixNetworkInterface *)pi->coreIntf.next; free(pi); } } return err; } #if USES_NETLINK // See for a description of NetLink // Open a socket that will receive interface change notifications mDNSlocal mStatus OpenIfNotifySocket(int *pFD) { mStatus err = mStatus_NoError; struct sockaddr_nl snl; int sock; int ret; sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock < 0) return errno; // Configure read to be non-blocking because inbound msg size is not known in advance (void) fcntl(sock, F_SETFL, O_NONBLOCK); /* Subscribe the socket to Link & IP addr notifications. */ mDNSPlatformMemZero(&snl, sizeof snl); snl.nl_family = AF_NETLINK; snl.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR; ret = bind(sock, (struct sockaddr *) &snl, sizeof snl); if (0 == ret) *pFD = sock; else err = errno; return err; } #if MDNS_DEBUGMSGS mDNSlocal void PrintNetLinkMsg(const struct nlmsghdr *pNLMsg) { const char *kNLMsgTypes[] = { "", "NLMSG_NOOP", "NLMSG_ERROR", "NLMSG_DONE", "NLMSG_OVERRUN" }; const char *kNLRtMsgTypes[] = { "RTM_NEWLINK", "RTM_DELLINK", "RTM_GETLINK", "RTM_NEWADDR", "RTM_DELADDR", "RTM_GETADDR" }; printf("nlmsghdr len=%d, type=%s, flags=0x%x\n", pNLMsg->nlmsg_len, pNLMsg->nlmsg_type < RTM_BASE ? kNLMsgTypes[pNLMsg->nlmsg_type] : kNLRtMsgTypes[pNLMsg->nlmsg_type - RTM_BASE], pNLMsg->nlmsg_flags); if (RTM_NEWLINK <= pNLMsg->nlmsg_type && pNLMsg->nlmsg_type <= RTM_GETLINK) { struct ifinfomsg *pIfInfo = (struct ifinfomsg*) NLMSG_DATA(pNLMsg); printf("ifinfomsg family=%d, type=%d, index=%d, flags=0x%x, change=0x%x\n", pIfInfo->ifi_family, pIfInfo->ifi_type, pIfInfo->ifi_index, pIfInfo->ifi_flags, pIfInfo->ifi_change); } else if (RTM_NEWADDR <= pNLMsg->nlmsg_type && pNLMsg->nlmsg_type <= RTM_GETADDR) { struct ifaddrmsg *pIfAddr = (struct ifaddrmsg*) NLMSG_DATA(pNLMsg); printf("ifaddrmsg family=%d, index=%d, flags=0x%x\n", pIfAddr->ifa_family, pIfAddr->ifa_index, pIfAddr->ifa_flags); } printf("\n"); } #endif mDNSlocal mDNSu32 ProcessRoutingNotification(int sd) // Read through the messages on sd and if any indicate that any interface records should // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0. { ssize_t readCount; char buff[4096]; struct nlmsghdr *pNLMsg = (struct nlmsghdr*) buff; mDNSu32 result = 0; // The structure here is more complex than it really ought to be because, // unfortunately, there's no good way to size a buffer in advance large // enough to hold all pending data and so avoid message fragmentation. // (Note that FIONREAD is not supported on AF_NETLINK.) readCount = read(sd, buff, sizeof buff); while (1) { // Make sure we've got an entire nlmsghdr in the buffer, and payload, too. // If not, discard already-processed messages in buffer and read more data. if (((char*) &pNLMsg[1] > (buff + readCount)) || // i.e. *pNLMsg extends off end of buffer ((char*) pNLMsg + pNLMsg->nlmsg_len > (buff + readCount))) { if (buff < (char*) pNLMsg) // we have space to shuffle { // discard processed data readCount -= ((char*) pNLMsg - buff); memmove(buff, pNLMsg, readCount); pNLMsg = (struct nlmsghdr*) buff; // read more data readCount += read(sd, buff + readCount, sizeof buff - readCount); continue; // spin around and revalidate with new readCount } else break; // Otherwise message does not fit in buffer } #if MDNS_DEBUGMSGS PrintNetLinkMsg(pNLMsg); #endif // Process the NetLink message if (pNLMsg->nlmsg_type == RTM_GETLINK || pNLMsg->nlmsg_type == RTM_NEWLINK) result |= 1 << ((struct ifinfomsg*) NLMSG_DATA(pNLMsg))->ifi_index; else if (pNLMsg->nlmsg_type == RTM_DELADDR || pNLMsg->nlmsg_type == RTM_NEWADDR) result |= 1 << ((struct ifaddrmsg*) NLMSG_DATA(pNLMsg))->ifa_index; // Advance pNLMsg to the next message in the buffer if ((pNLMsg->nlmsg_flags & NLM_F_MULTI) != 0 && pNLMsg->nlmsg_type != NLMSG_DONE) { ssize_t len = readCount - ((char*)pNLMsg - buff); pNLMsg = NLMSG_NEXT(pNLMsg, len); } else break; // all done! } return result; } #else // USES_NETLINK // Open a socket that will receive interface change notifications mDNSlocal mStatus OpenIfNotifySocket(int *pFD) { *pFD = socket(AF_ROUTE, SOCK_RAW, 0); if (*pFD < 0) return mStatus_UnknownErr; // Configure read to be non-blocking because inbound msg size is not known in advance (void) fcntl(*pFD, F_SETFL, O_NONBLOCK); return mStatus_NoError; } #if MDNS_DEBUGMSGS mDNSlocal void PrintRoutingSocketMsg(const struct ifa_msghdr *pRSMsg) { const char *kRSMsgTypes[] = { "", "RTM_ADD", "RTM_DELETE", "RTM_CHANGE", "RTM_GET", "RTM_LOSING", "RTM_REDIRECT", "RTM_MISS", "RTM_LOCK", "RTM_OLDADD", "RTM_OLDDEL", "RTM_RESOLVE", "RTM_NEWADDR", "RTM_DELADDR", "RTM_IFINFO", "RTM_NEWMADDR", "RTM_DELMADDR" }; int index = pRSMsg->ifam_type == RTM_IFINFO ? ((struct if_msghdr*) pRSMsg)->ifm_index : pRSMsg->ifam_index; printf("ifa_msghdr len=%d, type=%s, index=%d\n", pRSMsg->ifam_msglen, kRSMsgTypes[pRSMsg->ifam_type], index); } #endif mDNSlocal mDNSu32 ProcessRoutingNotification(int sd) // Read through the messages on sd and if any indicate that any interface records should // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0. { ssize_t readCount; char buff[4096]; struct ifa_msghdr *pRSMsg = (struct ifa_msghdr*) buff; mDNSu32 result = 0; readCount = read(sd, buff, sizeof buff); if (readCount < (ssize_t) sizeof(struct ifa_msghdr)) return mStatus_UnsupportedErr; // cannot decipher message #if MDNS_DEBUGMSGS PrintRoutingSocketMsg(pRSMsg); #endif // Process the message switch (pRSMsg->ifam_type) { case RTM_NEWADDR: case RTM_DELADDR: case RTM_IFINFO: /* * ADD & DELETE are happening when IPv6 announces are changing, * and for some reason it will stop mdnsd to announce IPv6 * addresses. So we force mdnsd to check interfaces. */ case RTM_ADD: case RTM_DELETE: if (pRSMsg->ifam_type == RTM_IFINFO) result |= 1 << ((struct if_msghdr*) pRSMsg)->ifm_index; else result |= 1 << pRSMsg->ifam_index; break; } return result; } #endif // USES_NETLINK // Called when data appears on interface change notification socket mDNSlocal void InterfaceChangeCallback(int fd, void *context) { IfChangeRec *pChgRec = (IfChangeRec*) context; fd_set readFDs; mDNSu32 changedInterfaces = 0; struct timeval zeroTimeout = { 0, 0 }; (void)fd; // Unused FD_ZERO(&readFDs); FD_SET(pChgRec->NotifySD, &readFDs); do { changedInterfaces |= ProcessRoutingNotification(pChgRec->NotifySD); } while (0 < select(pChgRec->NotifySD + 1, &readFDs, (fd_set*) NULL, (fd_set*) NULL, &zeroTimeout)); // Currently we rebuild the entire interface list whenever any interface change is // detected. If this ever proves to be a performance issue in a multi-homed // configuration, more care should be paid to changedInterfaces. if (changedInterfaces) mDNSPlatformPosixRefreshInterfaceList(pChgRec->mDNS); } // Register with either a Routing Socket or RtNetLink to listen for interface changes. mDNSlocal mStatus WatchForInterfaceChange(mDNS *const m) { mStatus err; IfChangeRec *pChgRec; pChgRec = (IfChangeRec*) mDNSPlatformMemAllocateClear(sizeof *pChgRec); if (pChgRec == NULL) return mStatus_NoMemoryErr; pChgRec->mDNS = m; err = OpenIfNotifySocket(&pChgRec->NotifySD); if (err == 0) err = mDNSPosixAddFDToEventLoop(pChgRec->NotifySD, InterfaceChangeCallback, pChgRec); if (err) mDNSPlatformMemFree(pChgRec); return err; } // Test to see if we're the first client running on UDP port 5353, by trying to bind to 5353 without using SO_REUSEPORT. // If we fail, someone else got here first. That's not a big problem; we can share the port for multicast responses -- // we just need to be aware that we shouldn't expect to successfully receive unicast UDP responses. mDNSlocal mDNSBool mDNSPlatformInit_CanReceiveUnicast(void) { int err; int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); struct sockaddr_in s5353; s5353.sin_family = AF_INET; s5353.sin_port = MulticastDNSPort.NotAnInteger; s5353.sin_addr.s_addr = 0; err = bind(s, (struct sockaddr *)&s5353, sizeof(s5353)); close(s); if (err) debugf("No unicast UDP responses"); else debugf("Unicast UDP responses okay"); return(err == 0); } // mDNS core calls this routine to initialise the platform-specific data. mDNSexport mStatus mDNSPlatformInit(mDNS *const m) { int err = 0; struct sockaddr sa; assert(m != NULL); if (mDNSPlatformInit_CanReceiveUnicast()) m->CanReceiveUnicastOn5353 = mDNStrue; // Tell mDNS core the names of this machine. // Set up the nice label m->nicelabel.c[0] = 0; GetUserSpecifiedFriendlyComputerName(&m->nicelabel); if (m->nicelabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->nicelabel, "Computer"); // Set up the RFC 1034-compliant label m->hostlabel.c[0] = 0; GetUserSpecifiedRFC1034ComputerName(&m->hostlabel); if (m->hostlabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->hostlabel, "Computer"); mDNS_SetFQDN(m); sa.sa_family = AF_INET; m->p->unicastSocket4 = -1; if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket4); #if HAVE_IPV6 sa.sa_family = AF_INET6; m->p->unicastSocket6 = -1; if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket6); #endif // Tell mDNS core about the network interfaces on this machine. if (err == mStatus_NoError) err = SetupInterfaceList(m); // Tell mDNS core about DNS Servers mDNS_Lock(m); if (err == mStatus_NoError) ParseDNSServers(m, uDNS_SERVERS_FILE); mDNS_Unlock(m); if (err == mStatus_NoError) { err = WatchForInterfaceChange(m); // Failure to observe interface changes is non-fatal. if (err != mStatus_NoError) { fprintf(stderr, "mDNS(%d) WARNING: Unable to detect interface changes (%d).\n", (int)getpid(), err); err = mStatus_NoError; } } // We don't do asynchronous initialization on the Posix platform, so by the time // we get here the setup will already have succeeded or failed. If it succeeded, // we should just call mDNSCoreInitComplete() immediately. if (err == mStatus_NoError) mDNSCoreInitComplete(m, mStatus_NoError); return PosixErrorToStatus(err); } // mDNS core calls this routine to clean up the platform-specific data. // In our case all we need to do is to tear down every network interface. mDNSexport void mDNSPlatformClose(mDNS *const m) { int rv; assert(m != NULL); ClearInterfaceList(m); if (m->p->unicastSocket4 != -1) { rv = close(m->p->unicastSocket4); assert(rv == 0); } #if HAVE_IPV6 if (m->p->unicastSocket6 != -1) { rv = close(m->p->unicastSocket6); assert(rv == 0); } #endif } // This is used internally by InterfaceChangeCallback. // It's also exported so that the Standalone Responder (mDNSResponderPosix) // can call it in response to a SIGHUP (mainly for debugging purposes). mDNSexport mStatus mDNSPlatformPosixRefreshInterfaceList(mDNS *const m) { int err; // This is a pretty heavyweight way to process interface changes -- // destroying the entire interface list and then making fresh one from scratch. // We should make it like the OS X version, which leaves unchanged interfaces alone. ClearInterfaceList(m); err = SetupInterfaceList(m); return PosixErrorToStatus(err); } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Locking #endif // On the Posix platform, locking is a no-op because we only ever enter // mDNS core on the main thread. // mDNS core calls this routine when it wants to prevent // the platform from reentering mDNS core code. mDNSexport void mDNSPlatformLock (const mDNS *const m) { (void) m; // Unused } // mDNS core calls this routine when it release the lock taken by // mDNSPlatformLock and allow the platform to reenter mDNS core code. mDNSexport void mDNSPlatformUnlock (const mDNS *const m) { (void) m; // Unused } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Strings #endif mDNSexport mDNSu32 mDNSPlatformStrLCopy(void *dst, const void *src, mDNSu32 len) { #if HAVE_STRLCPY return ((mDNSu32)strlcpy((char *)dst, (const char *)src, len)); #else size_t srcLen; srcLen = strlen((const char *)src); if (srcLen < len) { memcpy(dst, src, srcLen + 1); } else if (len > 0) { memcpy(dst, src, len - 1); ((char *)dst)[len - 1] = '\0'; } return ((mDNSu32)srcLen); #endif } // mDNS core calls this routine to get the length of a C string. // On the Posix platform this maps directly to the ANSI C strlen. mDNSexport mDNSu32 mDNSPlatformStrLen (const void *src) { return strlen((const char*)src); } // mDNS core calls this routine to copy memory. // On the Posix platform this maps directly to the ANSI C memcpy. mDNSexport void mDNSPlatformMemCopy(void *dst, const void *src, mDNSu32 len) { memcpy(dst, src, len); } // mDNS core calls this routine to test whether blocks of memory are byte-for-byte // identical. On the Posix platform this is a simple wrapper around ANSI C memcmp. mDNSexport mDNSBool mDNSPlatformMemSame(const void *dst, const void *src, mDNSu32 len) { return memcmp(dst, src, len) == 0; } // If the caller wants to know the exact return of memcmp, then use this instead // of mDNSPlatformMemSame mDNSexport int mDNSPlatformMemCmp(const void *dst, const void *src, mDNSu32 len) { return (memcmp(dst, src, len)); } mDNSexport void mDNSPlatformQsort(void *base, int nel, int width, int (*compar)(const void *, const void *)) { (void)qsort(base, nel, width, compar); } // Proxy stub functions mDNSexport mDNSu8 *DNSProxySetAttributes(DNSQuestion *q, DNSMessageHeader *h, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *limit) { (void) q; (void) h; (void) msg; (void) ptr; (void) limit; return ptr; } mDNSexport void DNSProxyInit(mDNSu32 IpIfArr[MaxIp], mDNSu32 OpIf) { (void) IpIfArr; (void) OpIf; } mDNSexport void DNSProxyTerminate(void) { } // mDNS core calls this routine to clear blocks of memory. // On the Posix platform this is a simple wrapper around ANSI C memset. mDNSexport void mDNSPlatformMemZero(void *dst, mDNSu32 len) { memset(dst, 0, len); } #if !MDNS_MALLOC_DEBUGGING mDNSexport void *mDNSPlatformMemAllocate(mDNSu32 len) { return(mallocL("mDNSPlatformMemAllocate", len)); } mDNSexport void *mDNSPlatformMemAllocateClear(mDNSu32 len) { return(callocL(name, len)); } mDNSexport void mDNSPlatformMemFree (void *mem) { freeL("mDNSPlatformMemFree", mem); } #endif #if _PLATFORM_HAS_STRONG_PRNG_ mDNSexport mDNSu32 mDNSPlatformRandomNumber(void) { return(arc4random()); } #else mDNSexport mDNSu32 mDNSPlatformRandomSeed(void) { struct timeval tv; gettimeofday(&tv, NULL); return(tv.tv_usec); } #endif mDNSexport mDNSs32 mDNSPlatformOneSecond = 1024; mDNSexport mStatus mDNSPlatformTimeInit(void) { // No special setup is required on Posix -- we just use gettimeofday(); // This is not really safe, because gettimeofday can go backwards if the user manually changes the date or time // We should find a better way to do this return(mStatus_NoError); } mDNSexport mDNSs32 mDNSPlatformRawTime() { struct timespec tm; int ret = clock_gettime(CLOCK_MONOTONIC, &tm); assert(ret == 0); // This call will only fail if the number of seconds does not fit in an object of type time_t. // tm.tv_sec is seconds since some unspecified starting point (it is usually the system start up time) // tm.tv_nsec is nanoseconds since the start of this second (i.e. values 0 to 999999999) // We use the lower 22 bits of tm.tv_sec for the top 22 bits of our result // and we multiply tm.tv_nsec by 2 / 1953125 to get a value in the range 0-1023 to go in the bottom 10 bits. // This gives us a proper modular (cyclic) counter that has a resolution of roughly 1ms (actually 1/1024 second) // and correctly cycles every 2^22 seconds (4194304 seconds = approx 48 days). return ((tm.tv_sec << 10) | (tm.tv_nsec * 2 / 1953125)); } mDNSexport mDNSs32 mDNSPlatformUTC(void) { return time(NULL); } mDNSexport void mDNSPlatformSendWakeupPacket(mDNSInterfaceID InterfaceID, char *EthAddr, char *IPAddr, int iteration) { (void) InterfaceID; (void) EthAddr; (void) IPAddr; (void) iteration; } mDNSexport mDNSBool mDNSPlatformValidRecordForInterface(const AuthRecord *rr, mDNSInterfaceID InterfaceID) { (void) rr; (void) InterfaceID; return 1; } mDNSexport mDNSBool mDNSPlatformValidQuestionForInterface(DNSQuestion *q, const NetworkInterfaceInfo *intf) { (void) q; (void) intf; return 1; } // Used for debugging purposes. For now, just set the buffer to zero mDNSexport void mDNSPlatformFormatTime(unsigned long te, mDNSu8 *buf, int bufsize) { (void) te; if (bufsize) buf[0] = 0; } mDNSexport void mDNSPlatformSendKeepalive(mDNSAddr *sadd, mDNSAddr *dadd, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu32 seq, mDNSu32 ack, mDNSu16 win) { (void) sadd; // Unused (void) dadd; // Unused (void) lport; // Unused (void) rport; // Unused (void) seq; // Unused (void) ack; // Unused (void) win; // Unused } mDNSexport mStatus mDNSPlatformRetrieveTCPInfo(mDNSAddr *laddr, mDNSIPPort *lport, mDNSAddr *raddr, mDNSIPPort *rport, mDNSTCPInfo *mti) { (void) laddr; // Unused (void) raddr; // Unused (void) lport; // Unused (void) rport; // Unused (void) mti; // Unused return mStatus_NoError; } mDNSexport mStatus mDNSPlatformGetRemoteMacAddr(mDNSAddr *raddr) { (void) raddr; // Unused return mStatus_NoError; } mDNSexport mStatus mDNSPlatformStoreSPSMACAddr(mDNSAddr *spsaddr, char *ifname) { (void) spsaddr; // Unused (void) ifname; // Unused return mStatus_NoError; } mDNSexport mStatus mDNSPlatformClearSPSData(void) { return mStatus_NoError; } mDNSexport mStatus mDNSPlatformStoreOwnerOptRecord(char *ifname, DNSMessage *msg, int length) { (void) ifname; // Unused (void) msg; // Unused (void) length; // Unused return mStatus_UnsupportedErr; } mDNSexport mDNSu16 mDNSPlatformGetUDPPort(UDPSocket *sock) { (void) sock; // unused return (mDNSu16)-1; } mDNSexport mDNSBool mDNSPlatformInterfaceIsD2D(mDNSInterfaceID InterfaceID) { (void) InterfaceID; // unused return mDNSfalse; } mDNSexport void mDNSPlatformSetSocktOpt(void *sock, mDNSTransport_Type transType, mDNSAddr_Type addrType, const DNSQuestion *q) { (void) sock; (void) transType; (void) addrType; (void) q; } mDNSexport mDNSs32 mDNSPlatformGetPID() { return 0; } mDNSlocal void mDNSPosixAddToFDSet(int *nfds, fd_set *readfds, int s) { if (*nfds < s + 1) *nfds = s + 1; FD_SET(s, readfds); } mDNSexport void mDNSPosixGetFDSetForSelect(mDNS *m, int *nfds, fd_set *readfds, fd_set *writefds) { int numFDs = *nfds; PosixEventSource *iSource; // 2. Build our list of active file descriptors PosixNetworkInterface *info = (PosixNetworkInterface *)(m->HostInterfaces); if (m->p->unicastSocket4 != -1) mDNSPosixAddToFDSet(&numFDs, readfds, m->p->unicastSocket4); #if HAVE_IPV6 if (m->p->unicastSocket6 != -1) mDNSPosixAddToFDSet(&numFDs, readfds, m->p->unicastSocket6); #endif while (info) { if (info->multicastSocket4 != -1) mDNSPosixAddToFDSet(&numFDs, readfds, info->multicastSocket4); #if HAVE_IPV6 if (info->multicastSocket6 != -1) mDNSPosixAddToFDSet(&numFDs, readfds, info->multicastSocket6); #endif info = (PosixNetworkInterface *)(info->coreIntf.next); } // Copy over the event fds. We have to do it this way because client-provided event loops expect // to initialize their FD sets first and then call mDNSPosixGetFDSet() for (iSource = gEventSources; iSource; iSource = iSource->next) { if (iSource->readCallback != NULL) FD_SET(iSource->fd, readfds); if (iSource->writeCallback != NULL) FD_SET(iSource->fd, writefds); if (numFDs <= iSource->fd) numFDs = iSource->fd + 1; } *nfds = numFDs; } mDNSexport void mDNSPosixGetNextDNSEventTime(mDNS *m, struct timeval *timeout) { mDNSs32 ticks; struct timeval interval; // 1. Call mDNS_Execute() to let mDNSCore do what it needs to do mDNSs32 nextevent = mDNS_Execute(m); // 3. Calculate the time remaining to the next scheduled event (in struct timeval format) ticks = nextevent - mDNS_TimeNow(m); if (ticks < 1) ticks = 1; interval.tv_sec = ticks >> 10; // The high 22 bits are seconds interval.tv_usec = ((ticks & 0x3FF) * 15625) / 16; // The low 10 bits are 1024ths // 4. If client's proposed timeout is more than what we want, then reduce it if (timeout->tv_sec > interval.tv_sec || (timeout->tv_sec == interval.tv_sec && timeout->tv_usec > interval.tv_usec)) *timeout = interval; } mDNSexport void mDNSPosixGetFDSet(mDNS *m, int *nfds, fd_set *readfds, fd_set *writefds, struct timeval *timeout) { mDNSPosixGetNextDNSEventTime(m, timeout); mDNSPosixGetFDSetForSelect(m, nfds, readfds, writefds); } mDNSexport void mDNSPosixProcessFDSet(mDNS *const m, fd_set *readfds, fd_set *writefds) { PosixNetworkInterface *info; PosixEventSource *iSource; assert(m != NULL); assert(readfds != NULL); info = (PosixNetworkInterface *)(m->HostInterfaces); if (m->p->unicastSocket4 != -1 && FD_ISSET(m->p->unicastSocket4, readfds)) { FD_CLR(m->p->unicastSocket4, readfds); SocketDataReady(m, NULL, m->p->unicastSocket4); } #if HAVE_IPV6 if (m->p->unicastSocket6 != -1 && FD_ISSET(m->p->unicastSocket6, readfds)) { FD_CLR(m->p->unicastSocket6, readfds); SocketDataReady(m, NULL, m->p->unicastSocket6); } #endif while (info) { if (info->multicastSocket4 != -1 && FD_ISSET(info->multicastSocket4, readfds)) { FD_CLR(info->multicastSocket4, readfds); SocketDataReady(m, info, info->multicastSocket4); } #if HAVE_IPV6 if (info->multicastSocket6 != -1 && FD_ISSET(info->multicastSocket6, readfds)) { FD_CLR(info->multicastSocket6, readfds); SocketDataReady(m, info, info->multicastSocket6); } #endif info = (PosixNetworkInterface *)(info->coreIntf.next); } // Now process routing socket events, discovery relay events and anything else of that ilk. for (iSource = gEventSources; iSource; iSource = iSource->next) { if (iSource->readCallback != NULL && FD_ISSET(iSource->fd, readfds)) { iSource->readCallback(iSource->fd, iSource->readContext); break; // in case callback removed elements from gEventSources } else if (iSource->writeCallback != NULL && FD_ISSET(iSource->fd, writefds)) { mDNSPosixEventCallback writeCallback = iSource->writeCallback; // Write events are one-shot: to get another event, the consumer has to put in a new request. // We reset this before calling the callback just in case the callback requests another write // callback, or deletes the event context from the list. iSource->writeCallback = NULL; writeCallback(iSource->fd, iSource->writeContext); break; // in case callback removed elements from gEventSources } } } mDNSu32 mDNSPlatformEventContextSize = sizeof (PosixEventSource); mDNSlocal void requestIOEvents(PosixEventSource *newSource, const char *taskName, mDNSPosixEventCallback callback, void *context, int flag) { PosixEventSource **epp = &gEventSources; if (newSource->fd >= (int) FD_SETSIZE || newSource->fd < 0) { LogMsg("requestIOEvents called with fd %d > FD_SETSIZE %d.", newSource->fd, FD_SETSIZE); assert(0); } if (callback == NULL) { LogMsg("requestIOEvents called no callback.", newSource->fd, FD_SETSIZE); assert(0); } // See if this event context is already on the list; if it is, no need to scan the list. if (!(newSource->flags & PosixEventFlag_OnList)) { while (*epp) { // This should never happen. if (newSource == *epp) { LogMsg("Event context marked not on list but is on list."); assert(0); } epp = &(*epp)->next; } if (*epp == NULL) { *epp = newSource; newSource->next = NULL; newSource->flags = PosixEventFlag_OnList; } } if (flag & PosixEventFlag_Read) { newSource->readCallback = callback; newSource->readContext = context; newSource->flags |= PosixEventFlag_Read; newSource->readTaskName = taskName; } if (flag & PosixEventFlag_Write) { newSource->writeCallback = callback; newSource->writeContext = context; newSource->flags |= PosixEventFlag_Write; newSource->writeTaskName = taskName; } } mDNSlocal void requestReadEvents(PosixEventSource *eventSource, const char *taskName, mDNSPosixEventCallback callback, void *context) { requestIOEvents(eventSource, taskName, callback, context, PosixEventFlag_Read); } mDNSlocal void requestWriteEvents(PosixEventSource *eventSource, const char *taskName, mDNSPosixEventCallback callback, void *context) { requestIOEvents(eventSource, taskName, callback, context, PosixEventFlag_Write); } // Remove a file descriptor from the set that mDNSPosixRunEventLoopOnce() listens to. mDNSlocal mStatus stopReadOrWriteEvents(int fd, mDNSBool freeContext, mDNSBool removeContext, int flags) { PosixEventSource *iSource, **epp = &gEventSources; while (*epp) { iSource = *epp; if (fd == iSource->fd) { if (flags & PosixEventFlag_Read) { iSource->readCallback = NULL; iSource->readContext = NULL; } if (flags & PosixEventFlag_Write) { iSource->writeCallback = NULL; iSource->writeContext = NULL; } if (iSource->writeCallback == NULL && iSource->readCallback == NULL) { if (removeContext || freeContext) *epp = iSource->next; if (freeContext) free(iSource); } return mStatus_NoError; } epp = &(*epp)->next; } return mStatus_NoSuchNameErr; } // Some of the mDNSPosix client code relies on being able to add FDs to the event loop without // providing storage for the event-related info. mDNSPosixAddFDToEventLoop and // mDNSPosixRemoveFDFromEventLoop handle the event structure storage automatically. mStatus mDNSPosixAddFDToEventLoop(int fd, mDNSPosixEventCallback callback, void *context) { PosixEventSource *newSource; newSource = (PosixEventSource*) malloc(sizeof *newSource); if (NULL == newSource) return mStatus_NoMemoryErr; memset(newSource, 0, sizeof *newSource); newSource->fd = fd; requestReadEvents(newSource, "mDNSPosixAddFDToEventLoop", callback, context); return mStatus_NoError; } mStatus mDNSPosixRemoveFDFromEventLoop(int fd) { return stopReadOrWriteEvents(fd, mDNStrue, mDNStrue, PosixEventFlag_Read | PosixEventFlag_Write); } // Simply note the received signal in gEventSignals. mDNSlocal void NoteSignal(int signum) { sigaddset(&gEventSignals, signum); } // Tell the event package to listen for signal and report it in mDNSPosixRunEventLoopOnce(). mStatus mDNSPosixListenForSignalInEventLoop(int signum) { struct sigaction action; mStatus err; mDNSPlatformMemZero(&action, sizeof action); // more portable than member-wise assignment action.sa_handler = NoteSignal; err = sigaction(signum, &action, (struct sigaction*) NULL); sigaddset(&gEventSignalSet, signum); return err; } // Tell the event package to stop listening for signal in mDNSPosixRunEventLoopOnce(). mStatus mDNSPosixIgnoreSignalInEventLoop(int signum) { struct sigaction action; mStatus err; mDNSPlatformMemZero(&action, sizeof action); // more portable than member-wise assignment action.sa_handler = SIG_DFL; err = sigaction(signum, &action, (struct sigaction*) NULL); sigdelset(&gEventSignalSet, signum); return err; } // Do a single pass through the attendent event sources and dispatch any found to their callbacks. // Return as soon as internal timeout expires, or a signal we're listening for is received. mStatus mDNSPosixRunEventLoopOnce(mDNS *m, const struct timeval *pTimeout, sigset_t *pSignalsReceived, mDNSBool *pDataDispatched) { fd_set listenFDs; fd_set writeFDs; int numFDs = 0, numReady; struct timeval timeout = *pTimeout; // 1. Set up the fd_set as usual here. // This example client has no file descriptors of its own, // but a real application would call FD_SET to add them to the set here FD_ZERO(&listenFDs); FD_ZERO(&writeFDs); // 2. Set up the timeout. mDNSPosixGetNextDNSEventTime(m, &timeout); // Include the sockets that are listening to the wire in our select() set mDNSPosixGetFDSetForSelect(m, &numFDs, &listenFDs, &writeFDs); numReady = select(numFDs, &listenFDs, &writeFDs, (fd_set*) NULL, &timeout); if (numReady > 0) { mDNSPosixProcessFDSet(m, &listenFDs, &writeFDs); *pDataDispatched = mDNStrue; } else if (numReady < 0) { if (errno != EINTR) { // This should never happen, represents a coding error, and is not recoverable, since // we'll just sit here spinning and never receive another event. The usual reason for // it to happen is that an FD was closed but not removed from the event list. LogMsg("select failed: %s", strerror(errno)); abort(); } } else *pDataDispatched = mDNSfalse; (void) sigprocmask(SIG_BLOCK, &gEventSignalSet, (sigset_t*) NULL); *pSignalsReceived = gEventSignals; sigemptyset(&gEventSignals); (void) sigprocmask(SIG_UNBLOCK, &gEventSignalSet, (sigset_t*) NULL); return mStatus_NoError; } /* -*- Mode: C; tab-width: 4; c-file-style: "bsd"; c-basic-offset: 4; fill-column: 108; indent-tabs-mode: nil; -*- * * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __mDNSPlatformPosix_h #define __mDNSPlatformPosix_h #include #include #ifdef __cplusplus extern "C" { #endif // PosixNetworkInterface is a record extension of the core NetworkInterfaceInfo // type that supports extra fields needed by the Posix platform. // // IMPORTANT: coreIntf must be the first field in the structure because // we cast between pointers to the two different types regularly. typedef struct PosixNetworkInterface PosixNetworkInterface; struct PosixNetworkInterface { NetworkInterfaceInfo coreIntf; // MUST be the first element in this structure mDNSs32 LastSeen; const char * intfName; PosixNetworkInterface * aliasIntf; int index; int multicastSocket4; #if HAVE_IPV6 int multicastSocket6; #endif }; // This is a global because debugf_() needs to be able to check its value extern int gMDNSPlatformPosixVerboseLevel; struct mDNS_PlatformSupport_struct { int unicastSocket4; #if HAVE_IPV6 int unicastSocket6; #endif }; // We keep a list of client-supplied event sources in PosixEventSource records // Add a file descriptor to the set that mDNSPosixRunEventLoopOnce() listens to. #define PosixEventFlag_OnList 1 #define PosixEventFlag_Read 2 #define PosixEventFlag_Write 4 typedef void (*mDNSPosixEventCallback)(int fd, void *context); struct PosixEventSource { struct PosixEventSource *next; mDNSPosixEventCallback readCallback; mDNSPosixEventCallback writeCallback; const char *readTaskName; const char *writeTaskName; void *readContext; void *writeContext; int fd; unsigned flags; }; typedef struct PosixEventSource PosixEventSource; struct TCPSocket_struct { mDNSIPPort port; // MUST BE FIRST FIELD -- mDNSCore expects every TCPSocket_struct to begin with mDNSIPPort TCPSocketFlags flags; // MUST BE SECOND FIELD -- mDNSCore expects every TCPSocket_struct have TCPSocketFlags flags after mDNSIPPort TCPConnectionCallback callback; PosixEventSource events; // SSL context goes here. domainname *hostname; mDNSAddr remoteAddress; mDNSIPPort remotePort; void *context; mDNSBool setup; mDNSBool connected; mStatus err; }; struct TCPListener_struct { TCPAcceptedCallback callback; PosixEventSource events; void *context; mDNSAddr_Type addressType; TCPSocketFlags socketFlags; }; #define uDNS_SERVERS_FILE "/etc/resolv.conf" extern int ParseDNSServers(mDNS *m, const char *filePath); extern mStatus mDNSPlatformPosixRefreshInterfaceList(mDNS *const m); // See comment in implementation. // Get the next upcoming mDNS (or DNS) event time as a posix timeval that can be passed to select. // This will only update timeout if the next mDNS event is sooner than the value that was passed. // Therefore, use { FutureTime, 0 } as an initializer if no other timer events are being managed. extern void mDNSPosixGetNextDNSEventTime(mDNS *m, struct timeval *timeout); // Returns all the FDs that the posix I/O event system expects to be passed to select. extern void mDNSPosixGetFDSetForSelect(mDNS *m, int *nfds, fd_set *readfds, fd_set *writefds); // Call mDNSPosixGetFDSet before calling select(), to update the parameters // as may be necessary to meet the needs of the mDNSCore code. // The timeout pointer MUST NOT be NULL. // Set timeout->tv_sec to FutureTime if you want to have effectively no timeout // After calling mDNSPosixGetFDSet(), call select(nfds, &readfds, NULL, NULL, &timeout); as usual // After select() returns, call mDNSPosixProcessFDSet() to let mDNSCore do its work // mDNSPosixGetFDSet simply calls mDNSPosixGetNextDNSEventTime and then mDNSPosixGetFDSetForSelect. extern void mDNSPosixGetFDSet(mDNS *m, int *nfds, fd_set *readfds, fd_set *writefds, struct timeval *timeout); extern void mDNSPosixProcessFDSet(mDNS *const m, fd_set *readfds, fd_set *writefds); extern mStatus mDNSPosixAddFDToEventLoop( int fd, mDNSPosixEventCallback callback, void *context); extern mStatus mDNSPosixRemoveFDFromEventLoop( int fd); extern mStatus mDNSPosixListenForSignalInEventLoop( int signum); extern mStatus mDNSPosixIgnoreSignalInEventLoop( int signum); extern mStatus mDNSPosixRunEventLoopOnce( mDNS *m, const struct timeval *pTimeout, sigset_t *pSignalsReceived, mDNSBool *pDataDispatched); extern mStatus mDNSPosixListenForSignalInEventLoop( int signum); extern mStatus mDNSPosixIgnoreSignalInEventLoop( int signum); extern mStatus mDNSPosixRunEventLoopOnce( mDNS *m, const struct timeval *pTimeout, sigset_t *pSignalsReceived, mDNSBool *pDataDispatched); #ifdef __cplusplus } #endif #endif /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2002-2018 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "mDNSUNP.h" #include #include #include #include #include #include #include #include #include /* Some weird platforms derived from 4.4BSD Lite (e.g. EFI) need the ALIGN(P) macro, usually defined in or someplace like that, to make sure the CMSG_NXTHDR macro is well-formed. On such platforms, the symbol NEED_ALIGN_MACRO should be set to the name of the header to include to get the ALIGN(P) macro. */ #ifdef NEED_ALIGN_MACRO #include NEED_ALIGN_MACRO #endif /* Solaris defined SIOCGIFCONF etc in but other platforms don't even have that include file. So, if we haven't yet got a definition, let's try to find . */ #ifndef SIOCGIFCONF #include #endif /* sockaddr_dl is only referenced if we're using IP_RECVIF, so only include the header in that case. */ #ifdef IP_RECVIF #include #endif #if defined(AF_INET6) && HAVE_IPV6 && !HAVE_LINUX #if !HAVE_SOLARIS #include #else #include #endif /* !HAVE_SOLARIS */ #include // Note: netinet/in_var.h implicitly includes netinet6/in6_var.h for us #endif #if defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX #include #include /* Converts a prefix length to IPv6 network mask */ void plen_to_mask(int plen, char *addr) { int i; int colons=7; /* Number of colons in IPv6 address */ int bits_in_block=16; /* Bits per IPv6 block */ for(i=0; i<=colons; i++) { int block, ones=0xffff, ones_in_block; if (plen>bits_in_block) ones_in_block=bits_in_block; else ones_in_block=plen; block = ones & (ones << (bits_in_block-ones_in_block)); i==0 ? sprintf(addr, "%x", block) : sprintf(addr, "%s:%x", addr, block); plen -= ones_in_block; } } /* Gets IPv6 interface information from the /proc filesystem in linux*/ struct ifi_info *get_ifi_info_linuxv6(int doaliases) { struct ifi_info *ifi, *ifihead, **ifipnext, *ifipold, **ifiptr; FILE *fp = NULL; int i, nitems, flags, index, plen, scope; struct addrinfo hints, *res0; int err; int sockfd = -1; struct ifreq ifr; char ifnameFmt[16], addrStr[32 + 7 + 1], ifname[IFNAMSIZ], lastname[IFNAMSIZ]; res0=NULL; ifihead = NULL; ifipnext = &ifihead; if ((fp = fopen(PROC_IFINET6_PATH, "r")) != NULL) { sockfd = socket(AF_INET6, SOCK_DGRAM, 0); if (sockfd < 0) { goto gotError; } // Parse /proc/net/if_inet6 according to . // Create a string specifier with a width of IFNAMSIZ - 1 ("%s") to scan the interface name. The // reason why we don't just use the string-ified macro expansion of IFNAMSIZ for the width is because the width // needs to be a decimal string and there's no guarantee that IFNAMSIZ will be defined as a decimal integer. For // example, it could be defined in hexadecimal or as an arithmetic expression. snprintf(ifnameFmt, sizeof(ifnameFmt), "%%%ds", IFNAMSIZ - 1); // Write the seven IPv6 address string colons and NUL terminator, i.e., "xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx". // The remaining 32 IPv6 address characters come from /proc/net/if_inet6. for (i = 4; i < 39; i += 5) addrStr[i] = ':'; addrStr[39] = '\0'; lastname[0] = '\0'; for (;;) { nitems = fscanf(fp, " %4c%4c%4c%4c%4c%4c%4c%4c %x %x %x %x", &addrStr[0], &addrStr[5], &addrStr[10], &addrStr[15], &addrStr[20], &addrStr[25], &addrStr[30], &addrStr[35], &index, &plen, &scope, &flags); if (nitems != 12) break; nitems = fscanf(fp, ifnameFmt, ifname); if (nitems != 1) break; if (strcmp(lastname, ifname) == 0) { if (doaliases == 0) continue; /* already processed this interface */ } memcpy(lastname, ifname, IFNAMSIZ); ifi = (struct ifi_info*)calloc(1, sizeof(struct ifi_info)); if (ifi == NULL) { goto gotError; } ifipold = *ifipnext; /* need this later */ ifiptr = ifipnext; *ifipnext = ifi; /* prev points to this new one */ ifipnext = &ifi->ifi_next; /* pointer to next one goes here */ /* Add address of the interface */ memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_INET6; hints.ai_flags = AI_NUMERICHOST; err = getaddrinfo(addrStr, NULL, &hints, &res0); if (err) { goto gotError; } ifi->ifi_addr = calloc(1, sizeof(struct sockaddr_in6)); if (ifi->ifi_addr == NULL) { goto gotError; } memcpy(ifi->ifi_addr, res0->ai_addr, sizeof(struct sockaddr_in6)); /* Add netmask of the interface */ char ipv6addr[INET6_ADDRSTRLEN]; plen_to_mask(plen, ipv6addr); ifi->ifi_netmask = calloc(1, sizeof(struct sockaddr_in6)); if (ifi->ifi_netmask == NULL) { goto gotError; } ((struct sockaddr_in6 *)ifi->ifi_netmask)->sin6_family=AF_INET6; ((struct sockaddr_in6 *)ifi->ifi_netmask)->sin6_scope_id=scope; inet_pton(AF_INET6, ipv6addr, &((struct sockaddr_in6 *)ifi->ifi_netmask)->sin6_addr); /* Add interface name */ memcpy(ifi->ifi_name, ifname, IFI_NAME); /* Add interface index */ ifi->ifi_index = index; /* Add interface flags*/ memcpy(ifr.ifr_name, ifname, IFNAMSIZ); if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) { if (errno == EADDRNOTAVAIL) { /* * If the main interface is configured with no IP address but * an alias interface exists with an IP address, you get * EADDRNOTAVAIL for the main interface */ free(ifi->ifi_addr); free(ifi->ifi_netmask); free(ifi); ifipnext = ifiptr; *ifipnext = ifipold; continue; } else { goto gotError; } } ifi->ifi_flags = ifr.ifr_flags; freeaddrinfo(res0); res0=NULL; } } goto done; gotError: if (ifihead != NULL) { free_ifi_info(ifihead); ifihead = NULL; } if (res0 != NULL) { freeaddrinfo(res0); res0=NULL; } done: if (sockfd != -1) { int rv; rv = close(sockfd); assert(rv == 0); } if (fp != NULL) { fclose(fp); } return(ifihead); /* pointer to first structure in linked list */ } #endif // defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX #if HAVE_SOLARIS /* * Converts prefix length to network mask. Assumes * addr points to a zeroed out buffer and prefix <= sizeof(addr) * Unlike plen_to_mask returns netmask in binary form and not * in text form. */ static void plen_to_netmask(int prefix, unsigned char *addr) { for (; prefix > 8; prefix -= 8) *addr++ = 0xff; for (; prefix > 0; prefix--) *addr = (*addr >> 1) | 0x80; } /* * This function goes through all the IP interfaces associated with a * physical interface and finds the best matched one for use by mDNS. * Returns NULL when none of the IP interfaces associated with a physical * interface are usable. Otherwise returns the best matched interface * information and a pointer to the best matched lifreq. */ struct ifi_info * select_src_ifi_info_solaris(int sockfd, int numifs, struct lifreq *lifrlist, const char *curifname, struct lifreq **best_lifr) { struct lifreq *lifr; struct lifreq lifrcopy; struct ifi_info *ifi; char *chptr; char cmpifname[LIFNAMSIZ]; int i; uint64_t best_lifrflags = 0; uint64_t ifflags; *best_lifr = NULL; /* * Check all logical interfaces associated with the physical * interface and figure out which one works best for us. */ for (i = numifs, lifr = lifrlist; i > 0; --i, ++lifr) { if (strlcpy(cmpifname, lifr->lifr_name, sizeof(cmpifname)) >= sizeof(cmpifname)) continue; /* skip interface */ /* Strip logical interface number before checking ifname */ if ((chptr = strchr(cmpifname, ':')) != NULL) *chptr = '\0'; /* * Check ifname to see if the logical interface is associated * with the physical interface we are interested in. */ if (strcmp(cmpifname, curifname) != 0) continue; lifrcopy = *lifr; if (ioctl(sockfd, SIOCGLIFFLAGS, &lifrcopy) < 0) { /* interface removed */ if (errno == ENXIO) continue; return(NULL); } ifflags = lifrcopy.lifr_flags; /* ignore address if not up */ if ((ifflags & IFF_UP) == 0) continue; /* * Avoid address if any of the following flags are set: * IFF_NOXMIT: no packets transmitted over interface * IFF_NOLOCAL: no address * IFF_PRIVATE: is not advertised */ if (ifflags & (IFF_NOXMIT | IFF_NOLOCAL | IFF_PRIVATE)) continue; /* A DHCP client will have IFF_UP set yet the address is zero. Ignore */ if (lifr->lifr_addr.ss_family == AF_INET) { struct sockaddr_in *sinptr; sinptr = (struct sockaddr_in *) &lifr->lifr_addr; if (sinptr->sin_addr.s_addr == INADDR_ANY) continue; } if (*best_lifr != NULL) { /* * Check if we found a better interface by checking * the flags. If flags are identical we prefer * the new found interface. */ uint64_t diff_flags = best_lifrflags ^ ifflags; /* If interface has a different set of flags */ if (diff_flags != 0) { /* Check flags in increasing order of ones we prefer */ /* Address temporary? */ if ((diff_flags & IFF_TEMPORARY) && (ifflags & IFF_TEMPORARY)) continue; /* Deprecated address? */ if ((diff_flags & IFF_DEPRECATED) && (ifflags & IFF_DEPRECATED)) continue; /* Last best-matched interface address has preferred? */ if ((diff_flags & IFF_PREFERRED) && ((ifflags & IFF_PREFERRED) == 0)) continue; } } /* Set best match interface & flags */ *best_lifr = lifr; best_lifrflags = ifflags; } if (*best_lifr == NULL) return(NULL); /* Found a match: return the interface information */ ifi = calloc(1, sizeof(struct ifi_info)); if (ifi == NULL) return(NULL); ifi->ifi_flags = best_lifrflags; ifi->ifi_index = if_nametoindex((*best_lifr)->lifr_name); if (strlcpy(ifi->ifi_name, (*best_lifr)->lifr_name, sizeof(ifi->ifi_name)) >= sizeof(ifi->ifi_name)) { free(ifi); return(NULL); } return(ifi); } /* * Returns a list of IP interface information on Solaris. The function * returns all IP interfaces on the system with IPv4 address assigned * when passed AF_INET and returns IP interfaces with IPv6 address assigned * when AF_INET6 is passed. */ struct ifi_info *get_ifi_info_solaris(int family) { struct ifi_info *ifi, *ifihead, **ifipnext; int sockfd; int len; char *buf; char *cptr; char ifname[LIFNAMSIZ], cmpifname[LIFNAMSIZ]; struct sockaddr_in *sinptr; struct lifnum lifn; struct lifconf lifc; struct lifreq *lifrp, *best_lifr; struct lifreq lifrcopy; int numifs, nlifr, n; #if defined(AF_INET6) && HAVE_IPV6 struct sockaddr_in6 *sinptr6; #endif ifihead = NULL; sockfd = socket(family, SOCK_DGRAM, 0); if (sockfd < 0) goto gotError; again: lifn.lifn_family = family; lifn.lifn_flags = 0; if (ioctl(sockfd, SIOCGLIFNUM, &lifn) < 0) goto gotError; /* * Pad interface count to detect & retrieve any * additional interfaces between IFNUM & IFCONF calls. */ lifn.lifn_count += 4; numifs = lifn.lifn_count; len = numifs * sizeof (struct lifreq); buf = alloca(len); lifc.lifc_family = family; lifc.lifc_len = len; lifc.lifc_buf = buf; lifc.lifc_flags = 0; if (ioctl(sockfd, SIOCGLIFCONF, &lifc) < 0) goto gotError; nlifr = lifc.lifc_len / sizeof(struct lifreq); if (nlifr >= numifs) goto again; lifrp = lifc.lifc_req; ifipnext = &ifihead; for (n = nlifr; n > 0; n--, lifrp++) { if (lifrp->lifr_addr.ss_family != family) continue; /* * See if we have already processed the interface * by checking the interface names. */ if (strlcpy(ifname, lifrp->lifr_name, sizeof(ifname)) >= sizeof(ifname)) goto gotError; if ((cptr = strchr(ifname, ':')) != NULL) *cptr = '\0'; /* * If any of the interfaces found so far share the physical * interface name then we have already processed the interface. */ for (ifi = ifihead; ifi != NULL; ifi = ifi->ifi_next) { /* Retrieve physical interface name */ (void) strlcpy(cmpifname, ifi->ifi_name, sizeof(cmpifname)); /* Strip logical interface number before checking ifname */ if ((cptr = strchr(cmpifname, ':')) != NULL) *cptr = '\0'; if (strcmp(cmpifname, ifname) == 0) break; } if (ifi != NULL) continue; /* already processed */ /* * New interface, find the one with the preferred source * address for our use in Multicast DNS. */ if ((ifi = select_src_ifi_info_solaris(sockfd, nlifr, lifc.lifc_req, ifname, &best_lifr)) == NULL) continue; assert(best_lifr != NULL); assert((best_lifr->lifr_addr.ss_family == AF_INET6) || (best_lifr->lifr_addr.ss_family == AF_INET)); switch (best_lifr->lifr_addr.ss_family) { #if defined(AF_INET6) && HAVE_IPV6 case AF_INET6: sinptr6 = (struct sockaddr_in6 *) &best_lifr->lifr_addr; ifi->ifi_addr = malloc(sizeof(struct sockaddr_in6)); if (ifi->ifi_addr == NULL) goto gotError; memcpy(ifi->ifi_addr, sinptr6, sizeof(struct sockaddr_in6)); ifi->ifi_netmask = calloc(1, sizeof(struct sockaddr_in6)); if (ifi->ifi_netmask == NULL) goto gotError; sinptr6 = (struct sockaddr_in6 *)(ifi->ifi_netmask); sinptr6->sin6_family = AF_INET6; plen_to_netmask(best_lifr->lifr_addrlen, (unsigned char *) &(sinptr6->sin6_addr)); break; #endif case AF_INET: sinptr = (struct sockaddr_in *) &best_lifr->lifr_addr; ifi->ifi_addr = malloc(sizeof(struct sockaddr_in)); if (ifi->ifi_addr == NULL) goto gotError; memcpy(ifi->ifi_addr, sinptr, sizeof(struct sockaddr_in)); lifrcopy = *best_lifr; if (ioctl(sockfd, SIOCGLIFNETMASK, &lifrcopy) < 0) { /* interface removed */ if (errno == ENXIO) { free(ifi->ifi_addr); free(ifi); continue; } goto gotError; } ifi->ifi_netmask = malloc(sizeof(struct sockaddr_in)); if (ifi->ifi_netmask == NULL) goto gotError; sinptr = (struct sockaddr_in *) &lifrcopy.lifr_addr; sinptr->sin_family = AF_INET; memcpy(ifi->ifi_netmask, sinptr, sizeof(struct sockaddr_in)); break; default: /* never reached */ break; } *ifipnext = ifi; /* prev points to this new one */ ifipnext = &ifi->ifi_next; /* pointer to next one goes here */ } (void) close(sockfd); return(ifihead); /* pointer to first structure in linked list */ gotError: if (sockfd != -1) (void) close(sockfd); if (ifihead != NULL) free_ifi_info(ifihead); return(NULL); } #endif /* HAVE_SOLARIS */ struct ifi_info *get_ifi_info(int family, int doaliases) { int junk; struct ifi_info *ifi, *ifihead, **ifipnext, *ifipold, **ifiptr; int sockfd, sockf6, len, lastlen, flags, myflags; #ifdef NOT_HAVE_IF_NAMETOINDEX int index = 200; #endif char *ptr, *buf, lastname[IFNAMSIZ], *cptr; struct ifconf ifc; struct ifreq *ifr, ifrcopy; struct sockaddr_in *sinptr; #if defined(AF_INET6) && HAVE_IPV6 struct sockaddr_in6 *sinptr6; #endif #if defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX if (family == AF_INET6) return get_ifi_info_linuxv6(doaliases); #elif HAVE_SOLARIS return get_ifi_info_solaris(family); #endif sockfd = -1; sockf6 = -1; buf = NULL; ifihead = NULL; sockfd = socket(AF_INET, SOCK_DGRAM, 0); if (sockfd < 0) { goto gotError; } lastlen = 0; len = 100 * sizeof(struct ifreq); /* initial buffer size guess */ for ( ; ; ) { buf = (char*)malloc(len); if (buf == NULL) { goto gotError; } ifc.ifc_len = len; ifc.ifc_buf = buf; if (ioctl(sockfd, SIOCGIFCONF, &ifc) < 0) { if (errno != EINVAL || lastlen != 0) { goto gotError; } } else { if (ifc.ifc_len == lastlen) break; /* success, len has not changed */ lastlen = ifc.ifc_len; } len += 10 * sizeof(struct ifreq); /* increment */ free(buf); } ifihead = NULL; ifipnext = &ifihead; lastname[0] = 0; /* end get_ifi_info1 */ /* include get_ifi_info2 */ for (ptr = buf; ptr < buf + ifc.ifc_len; ) { ifr = (struct ifreq *) ptr; /* Advance to next one in buffer */ if (sizeof(struct ifreq) > sizeof(ifr->ifr_name) + GET_SA_LEN(ifr->ifr_addr)) ptr += sizeof(struct ifreq); else ptr += sizeof(ifr->ifr_name) + GET_SA_LEN(ifr->ifr_addr); // fprintf(stderr, "intf %p name=%s AF=%d\n", index, ifr->ifr_name, ifr->ifr_addr.sa_family); if (ifr->ifr_addr.sa_family != family) continue; /* ignore if not desired address family */ myflags = 0; if ( (cptr = strchr(ifr->ifr_name, ':')) != NULL) *cptr = 0; /* replace colon will null */ if (strncmp(lastname, ifr->ifr_name, IFNAMSIZ) == 0) { if (doaliases == 0) continue; /* already processed this interface */ myflags = IFI_ALIAS; } memcpy(lastname, ifr->ifr_name, IFNAMSIZ); ifrcopy = *ifr; if (ioctl(sockfd, SIOCGIFFLAGS, &ifrcopy) < 0) { goto gotError; } flags = ifrcopy.ifr_flags; if ((flags & IFF_UP) == 0) continue; /* ignore if interface not up */ ifi = (struct ifi_info*)calloc(1, sizeof(struct ifi_info)); if (ifi == NULL) { goto gotError; } ifipold = *ifipnext; /* need this later */ ifiptr = ifipnext; *ifipnext = ifi; /* prev points to this new one */ ifipnext = &ifi->ifi_next; /* pointer to next one goes here */ ifi->ifi_flags = flags; /* IFF_xxx values */ ifi->ifi_myflags = myflags; /* IFI_xxx values */ #ifndef NOT_HAVE_IF_NAMETOINDEX ifi->ifi_index = if_nametoindex(ifr->ifr_name); #else ifrcopy = *ifr; #ifdef SIOCGIFINDEX if ( 0 >= ioctl(sockfd, SIOCGIFINDEX, &ifrcopy)) ifi->ifi_index = ifrcopy.ifr_index; else #endif ifi->ifi_index = index++; /* SIOCGIFINDEX is broken on Solaris 2.5ish, so fake it */ #endif memcpy(ifi->ifi_name, ifr->ifr_name, IFI_NAME); ifi->ifi_name[IFI_NAME-1] = '\0'; /* end get_ifi_info2 */ /* include get_ifi_info3 */ switch (ifr->ifr_addr.sa_family) { case AF_INET: sinptr = (struct sockaddr_in *) &ifr->ifr_addr; if (ifi->ifi_addr == NULL) { ifi->ifi_addr = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); if (ifi->ifi_addr == NULL) { goto gotError; } memcpy(ifi->ifi_addr, sinptr, sizeof(struct sockaddr_in)); #ifdef SIOCGIFNETMASK if (ioctl(sockfd, SIOCGIFNETMASK, &ifrcopy) < 0) { if (errno == EADDRNOTAVAIL) { /* * If the main interface is configured with no IP address but * an alias interface exists with an IP address, you get * EADDRNOTAVAIL for the main interface */ free(ifi->ifi_addr); free(ifi); ifipnext = ifiptr; *ifipnext = ifipold; continue; } else { goto gotError; } } ifi->ifi_netmask = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); if (ifi->ifi_netmask == NULL) goto gotError; sinptr = (struct sockaddr_in *) &ifrcopy.ifr_addr; /* The BSD ioctls (including Mac OS X) stick some weird values in for sin_len and sin_family */ #ifndef NOT_HAVE_SA_LEN sinptr->sin_len = sizeof(struct sockaddr_in); #endif sinptr->sin_family = AF_INET; memcpy(ifi->ifi_netmask, sinptr, sizeof(struct sockaddr_in)); #endif #ifdef SIOCGIFBRDADDR if (flags & IFF_BROADCAST) { if (ioctl(sockfd, SIOCGIFBRDADDR, &ifrcopy) < 0) { goto gotError; } sinptr = (struct sockaddr_in *) &ifrcopy.ifr_broadaddr; /* The BSD ioctls (including Mac OS X) stick some weird values in for sin_len and sin_family */ #ifndef NOT_HAVE_SA_LEN sinptr->sin_len = sizeof( struct sockaddr_in ); #endif sinptr->sin_family = AF_INET; ifi->ifi_brdaddr = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); if (ifi->ifi_brdaddr == NULL) { goto gotError; } memcpy(ifi->ifi_brdaddr, sinptr, sizeof(struct sockaddr_in)); } #endif #ifdef SIOCGIFDSTADDR if (flags & IFF_POINTOPOINT) { if (ioctl(sockfd, SIOCGIFDSTADDR, &ifrcopy) < 0) { goto gotError; } sinptr = (struct sockaddr_in *) &ifrcopy.ifr_dstaddr; /* The BSD ioctls (including Mac OS X) stick some weird values in for sin_len and sin_family */ #ifndef NOT_HAVE_SA_LEN sinptr->sin_len = sizeof( struct sockaddr_in ); #endif sinptr->sin_family = AF_INET; ifi->ifi_dstaddr = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in)); if (ifi->ifi_dstaddr == NULL) { goto gotError; } memcpy(ifi->ifi_dstaddr, sinptr, sizeof(struct sockaddr_in)); } #endif } break; #if defined(AF_INET6) && HAVE_IPV6 case AF_INET6: sinptr6 = (struct sockaddr_in6 *) &ifr->ifr_addr; if (ifi->ifi_addr == NULL) { ifi->ifi_addr = calloc(1, sizeof(struct sockaddr_in6)); if (ifi->ifi_addr == NULL) { goto gotError; } /* Some platforms (*BSD) inject the prefix in IPv6LL addresses */ /* We need to strip that out */ if (IN6_IS_ADDR_LINKLOCAL(&sinptr6->sin6_addr)) sinptr6->sin6_addr.s6_addr[2] = sinptr6->sin6_addr.s6_addr[3] = 0; memcpy(ifi->ifi_addr, sinptr6, sizeof(struct sockaddr_in6)); #ifdef SIOCGIFNETMASK_IN6 { struct in6_ifreq ifr6; if (sockf6 == -1) sockf6 = socket(AF_INET6, SOCK_DGRAM, 0); memset(&ifr6, 0, sizeof(ifr6)); memcpy(&ifr6.ifr_name, &ifr->ifr_name, sizeof(ifr6.ifr_name )); memcpy(&ifr6.ifr_ifru.ifru_addr, &ifr->ifr_addr, sizeof(ifr6.ifr_ifru.ifru_addr)); if (ioctl(sockf6, SIOCGIFNETMASK_IN6, &ifr6) < 0) { if (errno == EADDRNOTAVAIL) { /* * If the main interface is configured with no IP address but * an alias interface exists with an IP address, you get * EADDRNOTAVAIL for the main interface */ free(ifi->ifi_addr); free(ifi); ifipnext = ifiptr; *ifipnext = ifipold; continue; } else { goto gotError; } } ifi->ifi_netmask = (struct sockaddr*)calloc(1, sizeof(struct sockaddr_in6)); if (ifi->ifi_netmask == NULL) goto gotError; sinptr6 = (struct sockaddr_in6 *) &ifr6.ifr_ifru.ifru_addr; memcpy(ifi->ifi_netmask, sinptr6, sizeof(struct sockaddr_in6)); } #endif } break; #endif default: break; } } goto done; gotError: if (ifihead != NULL) { free_ifi_info(ifihead); ifihead = NULL; } done: if (buf != NULL) { free(buf); } if (sockfd != -1) { junk = close(sockfd); assert(junk == 0); } if (sockf6 != -1) { junk = close(sockf6); assert(junk == 0); } return(ifihead); /* pointer to first structure in linked list */ } /* end get_ifi_info3 */ /* include free_ifi_info */ void free_ifi_info(struct ifi_info *ifihead) { struct ifi_info *ifi, *ifinext; for (ifi = ifihead; ifi != NULL; ifi = ifinext) { if (ifi->ifi_addr != NULL) free(ifi->ifi_addr); if (ifi->ifi_netmask != NULL) free(ifi->ifi_netmask); if (ifi->ifi_brdaddr != NULL) free(ifi->ifi_brdaddr); if (ifi->ifi_dstaddr != NULL) free(ifi->ifi_dstaddr); ifinext = ifi->ifi_next; /* can't fetch ifi_next after free() */ free(ifi); /* the ifi_info{} itself */ } } /* end free_ifi_info */ ssize_t recvfrom_flags(int fd, void *ptr, size_t nbytes, int *flagsp, struct sockaddr *sa, socklen_t *salenptr, struct my_in_pktinfo *pktp, u_char *ttl) { struct msghdr msg; struct iovec iov[1]; ssize_t n; #ifdef CMSG_FIRSTHDR struct cmsghdr *cmptr; union { struct cmsghdr cm; char control[1024]; pad64_t align8; /* ensure structure is 8-byte aligned on sparc */ } control_un; *ttl = 255; // If kernel fails to provide TTL data then assume the TTL was 255 as it should be msg.msg_control = (void *) control_un.control; msg.msg_controllen = sizeof(control_un.control); msg.msg_flags = 0; #else memset(&msg, 0, sizeof(msg)); /* make certain msg_accrightslen = 0 */ #endif /* CMSG_FIRSTHDR */ msg.msg_name = (char *) sa; msg.msg_namelen = *salenptr; iov[0].iov_base = (char *)ptr; iov[0].iov_len = nbytes; msg.msg_iov = iov; msg.msg_iovlen = 1; if ( (n = recvmsg(fd, &msg, *flagsp)) < 0) return(n); *salenptr = msg.msg_namelen; /* pass back results */ if (pktp) { /* 0.0.0.0, i/f = -1 */ /* We set the interface to -1 so that the caller can tell whether we returned a meaningful value or just some default. Previously this code just set the value to 0, but I'm concerned that 0 might be a valid interface value. */ memset(pktp, 0, sizeof(struct my_in_pktinfo)); pktp->ipi_ifindex = -1; } /* end recvfrom_flags1 */ /* include recvfrom_flags2 */ #ifndef CMSG_FIRSTHDR #warning CMSG_FIRSTHDR not defined. Will not be able to determine destination address, received interface, etc. *flagsp = 0; /* pass back results */ return(n); #else *flagsp = msg.msg_flags; /* pass back results */ if (msg.msg_controllen < (socklen_t)sizeof(struct cmsghdr) || (msg.msg_flags & MSG_CTRUNC) || pktp == NULL) return(n); for (cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL; cmptr = CMSG_NXTHDR(&msg, cmptr)) { #ifdef IP_PKTINFO #if in_pktinfo_definition_is_missing struct in_pktinfo { int ipi_ifindex; struct in_addr ipi_spec_dst; struct in_addr ipi_addr; }; #endif if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO) { struct in_pktinfo *tmp; struct sockaddr_in *sin = (struct sockaddr_in*)&pktp->ipi_addr; tmp = (struct in_pktinfo *) CMSG_DATA(cmptr); sin->sin_family = AF_INET; sin->sin_addr = tmp->ipi_addr; sin->sin_port = 0; pktp->ipi_ifindex = tmp->ipi_ifindex; continue; } #endif #ifdef IP_RECVDSTADDR if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) { struct sockaddr_in *sin = (struct sockaddr_in*)&pktp->ipi_addr; sin->sin_family = AF_INET; sin->sin_addr = *(struct in_addr*)CMSG_DATA(cmptr); sin->sin_port = 0; continue; } #endif #ifdef IP_RECVIF if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) { struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA(cmptr); #ifndef HAVE_BROKEN_RECVIF_NAME int nameLen = (sdl->sdl_nlen < IFI_NAME - 1) ? sdl->sdl_nlen : (IFI_NAME - 1); strncpy(pktp->ipi_ifname, sdl->sdl_data, nameLen); #endif /* * the is memcpy used for sparc? no idea;) * pktp->ipi_ifindex = sdl->sdl_index; */ (void) memcpy(&pktp->ipi_ifindex, CMSG_DATA(cmptr), sizeof(uint_t)); #ifdef HAVE_BROKEN_RECVIF_NAME if (sdl->sdl_index == 0) { pktp->ipi_ifindex = *(uint_t*)sdl; } #endif assert(pktp->ipi_ifname[IFI_NAME - 1] == 0); // null terminated because of memset above continue; } #endif #ifdef IP_RECVTTL if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVTTL) { *ttl = *(u_char*)CMSG_DATA(cmptr); continue; } else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_TTL) { // some implementations seem to send IP_TTL instead of IP_RECVTTL *ttl = *(int*)CMSG_DATA(cmptr); continue; } #endif #if defined(IPV6_PKTINFO) && HAVE_IPV6 if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == IPV6_PKTINFO) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&pktp->ipi_addr; struct in6_pktinfo *ip6_info = (struct in6_pktinfo*)CMSG_DATA(cmptr); sin6->sin6_family = AF_INET6; #ifndef NOT_HAVE_SA_LEN sin6->sin6_len = sizeof(*sin6); #endif sin6->sin6_addr = ip6_info->ipi6_addr; sin6->sin6_flowinfo = 0; sin6->sin6_scope_id = 0; sin6->sin6_port = 0; pktp->ipi_ifindex = ip6_info->ipi6_ifindex; continue; } #endif #if defined(IPV6_HOPLIMIT) && HAVE_IPV6 if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == IPV6_HOPLIMIT) { *ttl = *(int*)CMSG_DATA(cmptr); continue; } #endif assert(0); // unknown ancillary data } return(n); #endif /* CMSG_FIRSTHDR */ } // ********************************************************************************************** // daemonize the process. Adapted from "Unix Network Programming" vol 1 by Stevens, section 12.4. // Returns 0 on success, -1 on failure. #ifdef NOT_HAVE_DAEMON #include #include #include int daemon(int nochdir, int noclose) { switch (fork()) { case -1: return (-1); // Fork failed case 0: break; // Child -- continue default: _exit(0); // Parent -- exit } if (setsid() == -1) return(-1); signal(SIGHUP, SIG_IGN); switch (fork()) // Fork again, primarily for reasons of Unix trivia { case -1: return (-1); // Fork failed case 0: break; // Child -- continue default: _exit(0); // Parent -- exit } if (!nochdir) (void)chdir("/"); umask(0); if (!noclose) { int fd = open("/dev/null", O_RDWR, 0); if (fd != -1) { // Avoid unnecessarily duplicating a file descriptor to itself if (fd != STDIN_FILENO) (void)dup2(fd, STDIN_FILENO); if (fd != STDOUT_FILENO) (void)dup2(fd, STDOUT_FILENO); if (fd != STDERR_FILENO) (void)dup2(fd, STDERR_FILENO); if (fd != STDIN_FILENO && fd != STDOUT_FILENO && fd != STDERR_FILENO) (void)close (fd); } } return (0); } #endif /* NOT_HAVE_DAEMON */ /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2002-2018 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __mDNSUNP_h #define __mDNSUNP_h #include #include #include #include #ifdef HAVE_LINUX #include #define IPV6_2292_PKTINFO IPV6_2292PKTINFO #define IPV6_2292_HOPLIMIT IPV6_2292HOPLIMIT #else // The following are the supported non-linux posix OSes - // netbsd, freebsd and openbsd. #if HAVE_IPV6 #define IPV6_2292_PKTINFO 19 #define IPV6_2292_HOPLIMIT 20 #endif #endif #ifdef __cplusplus extern "C" { #endif #ifdef NOT_HAVE_SOCKLEN_T typedef unsigned int socklen_t; #endif #ifndef NOT_HAVE_SA_LEN #define GET_SA_LEN(X) (sizeof(struct sockaddr) > ((struct sockaddr*)&(X))->sa_len ? \ sizeof(struct sockaddr) : ((struct sockaddr*)&(X))->sa_len ) #elif HAVE_IPV6 #define GET_SA_LEN(X) (((struct sockaddr*)&(X))->sa_family == AF_INET ? sizeof(struct sockaddr_in) : \ ((struct sockaddr*)&(X))->sa_family == AF_INET6 ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr)) #else #define GET_SA_LEN(X) (((struct sockaddr*)&(X))->sa_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr)) #endif #define IFI_NAME IFNAMSIZ /* same as IFNAMSIZ in */ #define IFI_HADDR 8 /* allow for 64-bit EUI-64 in future */ // Renamed from my_in_pktinfo because in_pktinfo is used by Linux. struct my_in_pktinfo { struct sockaddr_storage ipi_addr; int ipi_ifindex; /* received interface index */ char ipi_ifname[IFI_NAME]; /* received interface name */ }; /* From the text (Stevens, section 20.2): */ /* 'As an example of recvmsg we will write a function named recvfrom_flags that */ /* is similar to recvfrom but also returns: */ /* 1. the returned msg_flags value, */ /* 2. the destination addres of the received datagram (from the IP_RECVDSTADDR socket option, and */ /* 3. the index of the interface on which the datagram was received (the IP_RECVIF socket option).' */ extern ssize_t recvfrom_flags(int fd, void *ptr, size_t nbytes, int *flagsp, struct sockaddr *sa, socklen_t *salenptr, struct my_in_pktinfo *pktp, u_char *ttl); struct ifi_info { char ifi_name[IFI_NAME]; /* interface name, null terminated */ u_char ifi_haddr[IFI_HADDR]; /* hardware address */ u_short ifi_hlen; /* #bytes in hardware address: 0, 6, 8 */ short ifi_flags; /* IFF_xxx constants from */ short ifi_myflags; /* our own IFI_xxx flags */ int ifi_index; /* interface index */ struct sockaddr *ifi_addr; /* primary address */ struct sockaddr *ifi_netmask; struct sockaddr *ifi_brdaddr; /* broadcast address */ struct sockaddr *ifi_dstaddr; /* destination address */ struct ifi_info *ifi_next; /* next of these structures */ }; #define IFI_ALIAS 1 /* ifi_addr is an alias */ /* From the text (Stevens, section 16.6): */ /* 'Since many programs need to know all the interfaces on a system, we will develop a */ /* function of our own named get_ifi_info that returns a linked list of structures, one */ /* for each interface that is currently "up."' */ extern struct ifi_info *get_ifi_info(int family, int doaliases); /* 'The free_ifi_info function, which takes a pointer that was */ /* returned by get_ifi_info and frees all the dynamic memory.' */ extern void free_ifi_info(struct ifi_info *); #if defined(AF_INET6) && HAVE_IPV6 #define INET6_ADDRSTRLEN 46 /*Maximum length of IPv6 address */ #endif #ifdef NOT_HAVE_DAEMON extern int daemon(int nochdir, int noclose); #endif #ifdef __cplusplus } #endif #endif // // posix_utilities.c // mDNSResponder // // Copyright (c) 2019 Apple Inc. All rights reserved. // #include "posix_utilities.h" #include "mDNSEmbeddedAPI.h" #include // for NULL #include // for snprintf #include #include // for gettimeofday mDNSexport void getLocalTimestamp(char * const buffer, mDNSu32 buffer_len) { struct timeval now; struct tm local_time; char date_time_str[32]; char time_zone_str[32]; gettimeofday(&now, NULL); localtime_r(&now.tv_sec, &local_time); strftime(date_time_str, sizeof(date_time_str), "%F %T", &local_time); strftime(time_zone_str, sizeof(time_zone_str), "%z", &local_time); snprintf(buffer, buffer_len, "%s.%06lu%s", date_time_str, (unsigned long)now.tv_usec, time_zone_str); } // // posix_utilities.h // mDNSResponder // // Copyright (c) 2019 Apple Inc. All rights reserved. // #ifndef posix_utilities_h #define posix_utilities_h #include "mDNSEmbeddedAPI.h" // timestamp format: "2008-08-08 20:00:00.000000+0800", a 64-byte buffer is enough to store the result extern void getLocalTimestamp(char * const buffer, mDNSu32 buffer_len); #endif /* posix_utilities_h */ /* * Copyright (c) 2018-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "ClientRequests.h" #include "DNSCommon.h" #include "uDNS.h" #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) #include "QuerierSupport.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) #include "D2D.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, REACHABILITY_TRIGGER) #include "mDNSMacOSX.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, UNREADY_INTERFACES) #include #include #endif #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) #include int WCFIsServerRunning(WCFConnection *conn) __attribute__((weak_import)); int WCFNameResolvesToAddr(WCFConnection *conn, char* domainName, struct sockaddr* address, uid_t userid) __attribute__((weak_import)); int WCFNameResolvesToName(WCFConnection *conn, char* fromName, char* toName, uid_t userid) __attribute__((weak_import)); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #include "dnssec_v2.h" #endif #define RecordTypeIsAddress(TYPE) (((TYPE) == kDNSType_A) || ((TYPE) == kDNSType_AAAA)) extern mDNS mDNSStorage; #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) extern domainname ActiveDirectoryPrimaryDomain; #endif // Normally we append search domains only for queries with a single label that are not fully qualified. This can be // overridden to apply search domains for queries (that are not fully qualified) with any number of labels e.g., moon, // moon.cs, moon.cs.be, etc. - Mohan mDNSBool AlwaysAppendSearchDomains = mDNSfalse; // Control enabling optimistic DNS - Phil mDNSBool EnableAllowExpired = mDNStrue; typedef struct { mDNSu32 requestID; const domainname * qname; mDNSu16 qtype; mDNSu16 qclass; mDNSInterfaceID interfaceID; mDNSs32 serviceID; mDNSu32 flags; mDNSBool appendSearchDomains; mDNSs32 effectivePID; const mDNSu8 * effectiveUUID; mDNSu32 peerUID; mDNSBool isInAppBrowserRequest; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) const mDNSu8 * resolverUUID; mdns_dns_service_id_t customID; mDNSBool needEncryption; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) const audit_token_t * peerAuditToken; const audit_token_t * delegatorAuditToken; #endif } QueryRecordOpParams; mDNSlocal void QueryRecordOpParamsInit(QueryRecordOpParams *inParams) { mDNSPlatformMemZero(inParams, (mDNSu32)sizeof(*inParams)); inParams->serviceID = -1; } mDNSlocal mStatus QueryRecordOpCreate(QueryRecordOp **outOp); mDNSlocal void QueryRecordOpFree(QueryRecordOp *operation); mDNSlocal mStatus QueryRecordOpStart(QueryRecordOp *inOp, const QueryRecordOpParams *inParams, QueryRecordResultHandler inResultHandler, void *inResultContext); mDNSlocal void QueryRecordOpStop(QueryRecordOp *op); mDNSlocal mDNSBool QueryRecordOpIsMulticast(const QueryRecordOp *op); mDNSlocal void QueryRecordOpCallback(mDNS *m, DNSQuestion *inQuestion, const ResourceRecord *inAnswer, QC_result inAddRecord); mDNSlocal void QueryRecordOpResetHandler(DNSQuestion *inQuestion); mDNSlocal mStatus QueryRecordOpStartQuestion(QueryRecordOp *inOp, DNSQuestion *inQuestion); mDNSlocal mStatus QueryRecordOpStopQuestion(DNSQuestion *inQuestion); mDNSlocal mStatus QueryRecordOpRestartUnicastQuestion(QueryRecordOp *inOp, DNSQuestion *inQuestion, const domainname *inSearchDomain); mDNSlocal mStatus InterfaceIndexToInterfaceID(mDNSu32 inInterfaceIndex, mDNSInterfaceID *outInterfaceID); mDNSlocal mDNSBool DomainNameIsSingleLabel(const domainname *inName); mDNSlocal mDNSBool StringEndsWithDot(const char *inString); mDNSlocal const domainname * NextSearchDomain(QueryRecordOp *inOp); #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) mDNSlocal mDNSBool DomainNameIsInSearchList(const domainname *domain, mDNSBool inExcludeLocal); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) mDNSlocal void NotifyWebContentFilter(const ResourceRecord *inAnswer, uid_t inUID); #endif mDNSexport void GetAddrInfoClientRequestParamsInit(GetAddrInfoClientRequestParams *inParams) { mDNSPlatformMemZero(inParams, (mDNSu32)sizeof(*inParams)); } mDNSexport mStatus GetAddrInfoClientRequestStart(GetAddrInfoClientRequest *inRequest, const GetAddrInfoClientRequestParams *inParams, QueryRecordResultHandler inResultHandler, void *inResultContext) { mStatus err; domainname hostname; mDNSBool appendSearchDomains; mDNSInterfaceID interfaceID; DNSServiceFlags flags; mDNSs32 serviceID; QueryRecordOpParams opParams; if (!MakeDomainNameFromDNSNameString(&hostname, inParams->hostnameStr)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] ERROR: bad hostname '" PRI_S "'", inParams->requestID, inParams->hostnameStr); err = mStatus_BadParamErr; goto exit; } if (inParams->protocols & ~(kDNSServiceProtocol_IPv4|kDNSServiceProtocol_IPv6)) { err = mStatus_BadParamErr; goto exit; } flags = inParams->flags; if (inParams->protocols == 0) { flags |= kDNSServiceFlagsSuppressUnusable; inRequest->protocols = kDNSServiceProtocol_IPv4 | kDNSServiceProtocol_IPv6; } else { inRequest->protocols = inParams->protocols; } if (flags & kDNSServiceFlagsServiceIndex) { // NOTE: kDNSServiceFlagsServiceIndex flag can only be set for DNSServiceGetAddrInfo() LogInfo("GetAddrInfoClientRequestStart: kDNSServiceFlagsServiceIndex is SET by the client"); // If kDNSServiceFlagsServiceIndex is SET, interpret the interfaceID as the serviceId and set the interfaceID to 0. serviceID = (mDNSs32)inParams->interfaceIndex; interfaceID = mDNSNULL; } else { serviceID = -1; err = InterfaceIndexToInterfaceID(inParams->interfaceIndex, &interfaceID); if (err) goto exit; } inRequest->interfaceID = interfaceID; if (!StringEndsWithDot(inParams->hostnameStr) && (AlwaysAppendSearchDomains || DomainNameIsSingleLabel(&hostname))) { appendSearchDomains = mDNStrue; } else { appendSearchDomains = mDNSfalse; } QueryRecordOpParamsInit(&opParams); opParams.requestID = inParams->requestID; opParams.qname = &hostname; opParams.qclass = kDNSClass_IN; opParams.interfaceID = inRequest->interfaceID; opParams.serviceID = serviceID; opParams.flags = flags; opParams.appendSearchDomains = appendSearchDomains; opParams.effectivePID = inParams->effectivePID; opParams.effectiveUUID = inParams->effectiveUUID; opParams.peerUID = inParams->peerUID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) opParams.resolverUUID = inParams->resolverUUID; opParams.customID = inParams->customID; opParams.needEncryption = inParams->needEncryption; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) opParams.peerAuditToken = inParams->peerAuditToken; opParams.delegatorAuditToken = inParams->delegatorAuditToken; opParams.isInAppBrowserRequest = inParams->isInAppBrowserRequest; #endif if (inRequest->protocols & kDNSServiceProtocol_IPv6) { err = QueryRecordOpCreate(&inRequest->op6); if (err) goto exit; opParams.qtype = kDNSType_AAAA; err = QueryRecordOpStart(inRequest->op6, &opParams, inResultHandler, inResultContext); if (err) goto exit; } if (inRequest->protocols & kDNSServiceProtocol_IPv4) { err = QueryRecordOpCreate(&inRequest->op4); if (err) goto exit; opParams.qtype = kDNSType_A; err = QueryRecordOpStart(inRequest->op4, &opParams, inResultHandler, inResultContext); if (err) goto exit; } err = mStatus_NoError; exit: if (err) GetAddrInfoClientRequestStop(inRequest); return err; } mDNSexport void GetAddrInfoClientRequestStop(GetAddrInfoClientRequest *inRequest) { if (inRequest->op4) QueryRecordOpStop(inRequest->op4); if (inRequest->op6) QueryRecordOpStop(inRequest->op6); #if MDNSRESPONDER_SUPPORTS(APPLE, REACHABILITY_TRIGGER) { const QueryRecordOp * const op4 = inRequest->op4; const QueryRecordOp * const op6 = inRequest->op6; const DNSQuestion * q4 = mDNSNULL; const DNSQuestion * q6 = mDNSNULL; if (op4) { if (op4->answered) { // If we have a v4 answer and if we timed out prematurely before, provide a trigger to the upper layer so // that it can retry questions if needed. - Mohan q4 = &op4->q; } else if (op4->q.TimeoutQuestion) { // If we are not delivering answers, we may be timing out prematurely. Note down the current state so that // we know to retry when we see a valid response again. - Mohan mDNSPlatformUpdateDNSStatus(&op4->q); } } if (op6) { if (op6->answered) { q6 = &op6->q; } else if (op6->q.TimeoutQuestion) { mDNSPlatformUpdateDNSStatus(&op6->q); } } mDNSPlatformTriggerDNSRetry(q4, q6); } #endif if (inRequest->op4) { QueryRecordOpFree(inRequest->op4); inRequest->op4 = mDNSNULL; } if (inRequest->op6) { QueryRecordOpFree(inRequest->op6); inRequest->op6 = mDNSNULL; } } mDNSexport const domainname * GetAddrInfoClientRequestGetQName(const GetAddrInfoClientRequest *inRequest) { if (inRequest->op4) return &inRequest->op4->q.qname; if (inRequest->op6) return &inRequest->op6->q.qname; return (const domainname *)""; } mDNSexport mDNSBool GetAddrInfoClientRequestIsMulticast(const GetAddrInfoClientRequest *inRequest) { if ((inRequest->op4 && QueryRecordOpIsMulticast(inRequest->op4)) || (inRequest->op6 && QueryRecordOpIsMulticast(inRequest->op6))) { return mDNStrue; } return mDNSfalse; } mDNSexport void QueryRecordClientRequestParamsInit(QueryRecordClientRequestParams *inParams) { mDNSPlatformMemZero(inParams, (mDNSu32)sizeof(*inParams)); } mDNSexport mStatus QueryRecordClientRequestStart(QueryRecordClientRequest *inRequest, const QueryRecordClientRequestParams *inParams, QueryRecordResultHandler inResultHandler, void *inResultContext) { mStatus err; domainname qname; mDNSInterfaceID interfaceID; mDNSBool appendSearchDomains; QueryRecordOpParams opParams; #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) dnssec_context_t * dnssecContext = mDNSNULL; #endif err = InterfaceIndexToInterfaceID(inParams->interfaceIndex, &interfaceID); if (err) goto exit; if (!MakeDomainNameFromDNSNameString(&qname, inParams->qnameStr)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] ERROR: bad domain name '" PRI_S "'", inParams->requestID, inParams->qnameStr); err = mStatus_BadParamErr; goto exit; } if (RecordTypeIsAddress(inParams->qtype) && !StringEndsWithDot(inParams->qnameStr) && (AlwaysAppendSearchDomains || DomainNameIsSingleLabel(&qname))) { appendSearchDomains = mDNStrue; } else { appendSearchDomains = mDNSfalse; } QueryRecordOpParamsInit(&opParams); opParams.requestID = inParams->requestID; opParams.qname = &qname; opParams.qtype = inParams->qtype; opParams.qclass = inParams->qclass; opParams.interfaceID = interfaceID; opParams.appendSearchDomains = appendSearchDomains; opParams.effectivePID = inParams->effectivePID; opParams.effectiveUUID = inParams->effectiveUUID; opParams.peerUID = inParams->peerUID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) opParams.resolverUUID = inParams->resolverUUID; opParams.customID = inParams->customID; opParams.needEncryption = inParams->needEncryption; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) opParams.peerAuditToken = inParams->peerAuditToken; opParams.delegatorAuditToken = inParams->delegatorAuditToken; opParams.isInAppBrowserRequest = inParams->isInAppBrowserRequest; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // Query ends with ".local." and query for RRSIG or ANY type cannot be validated by DNSSEC even if the user sets the // kDNSServiceFlagsEnableDNSSEC flag. if (FLAGS_CONTAIN_DNSOK_BIT(inParams->flags) && is_eligible_for_dnssec(&qname, inParams->qtype)) { opParams.flags = inParams->flags | kDNSServiceFlagsReturnIntermediates; // to handle CNAME reference err = create_dnssec_context_t(inRequest, inParams->requestID, &qname, inParams->qtype, inParams->qclass, interfaceID, -1, inParams->flags, appendSearchDomains, inParams->effectivePID, inParams->effectiveUUID, inParams->peerUID, #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) inParams->peerAuditToken, inParams->delegatorAuditToken, #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSNULL, inParams->needEncryption, inParams->customID, #endif inResultHandler, inResultContext, mDNSNULL, &dnssecContext); require_action(err == mStatus_NoError, exit, log_debug("create_dnssec_context_t failed; error_description='%s'", mStatusDescription(err))); err = QueryRecordOpStart(&inRequest->op, &opParams, query_record_result_reply_with_dnssec, dnssecContext); } else #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) { opParams.flags = inParams->flags; err = QueryRecordOpStart(&inRequest->op, &opParams, inResultHandler, inResultContext); } exit: if (err) QueryRecordClientRequestStop(inRequest); return err; } mDNSexport void QueryRecordClientRequestStop(QueryRecordClientRequest *inRequest) { QueryRecordOpStop(&inRequest->op); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) stop_dnssec_if_enable_dnssec(inRequest); #endif #if MDNSRESPONDER_SUPPORTS(APPLE, REACHABILITY_TRIGGER) if (inRequest->op.answered) { DNSQuestion *v4q, *v6q; // If we are receiving positive answers, provide the hint to the upper layer. - Mohan v4q = (inRequest->op.q.qtype == kDNSType_A) ? &inRequest->op.q : mDNSNULL; v6q = (inRequest->op.q.qtype == kDNSType_AAAA) ? &inRequest->op.q : mDNSNULL; mDNSPlatformTriggerDNSRetry(v4q, v6q); } #endif } mDNSexport const domainname * QueryRecordClientRequestGetQName(const QueryRecordClientRequest *inRequest) { return &inRequest->op.q.qname; } mDNSexport mDNSu16 QueryRecordClientRequestGetType(const QueryRecordClientRequest *inRequest) { return inRequest->op.q.qtype; } mDNSexport mDNSBool QueryRecordClientRequestIsMulticast(QueryRecordClientRequest *inRequest) { return (QueryRecordOpIsMulticast(&inRequest->op) ? mDNStrue : mDNSfalse); } #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) mDNSexport mStatus QueryRecordOpStartForClientRequest( QueryRecordOp * inOp, mDNSu32 inReqID, const domainname * inQName, mDNSu16 inQType, mDNSu16 inQClass, mDNSInterfaceID inInterfaceID, mDNSs32 inServiceID, mDNSu32 inFlags, mDNSBool inAppendSearchDomains, mDNSs32 inPID, const mDNSu8 inUUID[UUID_SIZE], mDNSu32 inUID, #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) const audit_token_t * inPeerAuditTokenPtr, const audit_token_t * inDelegateAuditTokenPtr, #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) const mDNSu8 inResolverUUID[UUID_SIZE], mDNSBool inNeedEncryption, const mdns_dns_service_id_t inCustomID, #endif QueryRecordResultHandler inResultHandler, void * inResultContext) { QueryRecordOpParams opParams; QueryRecordOpParamsInit(&opParams); opParams.requestID = inReqID; opParams.qname = inQName; opParams.qtype = inQType; opParams.qclass = inQClass; opParams.interfaceID = inInterfaceID; opParams.serviceID = inServiceID; opParams.flags = inFlags; opParams.appendSearchDomains = inAppendSearchDomains; opParams.effectivePID = inPID; opParams.effectiveUUID = inUUID; opParams.peerUID = inUID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) opParams.resolverUUID = inResolverUUID; opParams.customID = inCustomID; opParams.needEncryption = inNeedEncryption; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) opParams.peerAuditToken = inPeerAuditTokenPtr; opParams.delegatorAuditToken = inDelegateAuditTokenPtr; #endif return QueryRecordOpStart(inOp, &opParams, inResultHandler, inResultContext); } mDNSexport void QueryRecordOpStopForClientRequest(QueryRecordOp *op) { QueryRecordOpStop(op); } #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) mDNSlocal mStatus QueryRecordOpCreate(QueryRecordOp **outOp) { mStatus err; QueryRecordOp *op; op = (QueryRecordOp *) mDNSPlatformMemAllocateClear(sizeof(*op)); if (!op) { err = mStatus_NoMemoryErr; goto exit; } *outOp = op; err = mStatus_NoError; exit: return err; } mDNSlocal void QueryRecordOpFree(QueryRecordOp *operation) { mDNSPlatformMemFree(operation); } #define VALID_MSAD_SRV_TRANSPORT(T) \ (SameDomainLabel((T)->c, (const mDNSu8 *)"\x4_tcp") || SameDomainLabel((T)->c, (const mDNSu8 *)"\x4_udp")) #define VALID_MSAD_SRV(Q) ((Q)->qtype == kDNSType_SRV && VALID_MSAD_SRV_TRANSPORT(SecondLabel(&(Q)->qname))) mDNSlocal mStatus QueryRecordOpStart(QueryRecordOp *inOp, const QueryRecordOpParams *inParams, QueryRecordResultHandler inResultHandler, void *inResultContext) { mStatus err; DNSQuestion * const q = &inOp->q; mDNSu32 len; // Save the original qname. len = DomainNameLength(inParams->qname); inOp->qname = (domainname *) mDNSPlatformMemAllocate(len); if (!inOp->qname) { err = mStatus_NoMemoryErr; goto exit; } mDNSPlatformMemCopy(inOp->qname, inParams->qname, len); inOp->interfaceID = inParams->interfaceID; inOp->reqID = inParams->requestID; inOp->resultHandler = inResultHandler; inOp->resultContext = inResultContext; // Set up DNSQuestion. if (EnableAllowExpired && (inParams->flags & kDNSServiceFlagsAllowExpiredAnswers)) { q->allowExpired = AllowExpired_AllowExpiredAnswers; } else { q->allowExpired = AllowExpired_None; } q->ServiceID = inParams->serviceID; #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) q->inAppBrowserRequest = inParams->isInAppBrowserRequest; if (inParams->peerAuditToken) { q->peerAuditToken = *inParams->peerAuditToken; } if (inParams->delegatorAuditToken) { q->delegateAuditToken = *inParams->delegatorAuditToken; } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (inParams->resolverUUID) { mDNSPlatformMemCopy(q->ResolverUUID, inParams->resolverUUID, UUID_SIZE); } #endif q->InterfaceID = inParams->interfaceID; q->flags = inParams->flags; AssignDomainName(&q->qname, inParams->qname); q->qtype = inParams->qtype; q->qclass = inParams->qclass; q->LongLived = (inParams->flags & kDNSServiceFlagsLongLivedQuery) ? mDNStrue : mDNSfalse; q->ForceMCast = (inParams->flags & kDNSServiceFlagsForceMulticast) ? mDNStrue : mDNSfalse; q->ReturnIntermed = (inParams->flags & kDNSServiceFlagsReturnIntermediates) ? mDNStrue : mDNSfalse; q->SuppressUnusable = (inParams->flags & kDNSServiceFlagsSuppressUnusable) ? mDNStrue : mDNSfalse; q->TimeoutQuestion = (inParams->flags & kDNSServiceFlagsTimeout) ? mDNStrue : mDNSfalse; q->UseBackgroundTraffic = (inParams->flags & kDNSServiceFlagsBackgroundTrafficClass) ? mDNStrue : mDNSfalse; q->AppendSearchDomains = inParams->appendSearchDomains; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) q->RequireEncryption = inParams->needEncryption; q->CustomID = inParams->customID; #endif q->InitialCacheMiss = mDNSfalse; #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) err = initialize_dnssec_status_t(&q->DNSSECStatus, inParams->qname, inParams->qtype, inParams->flags, inResultContext); require_action(err == mStatus_NoError, exit, log_debug("initialize_dnssec_status failed; error_description='%s'", mStatusDescription(err))); #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) q->pid = inParams->effectivePID; if (inParams->effectiveUUID) { mDNSPlatformMemCopy(q->uuid, inParams->effectiveUUID, UUID_SIZE); } q->euid = inParams->peerUID; q->request_id = inParams->requestID; q->QuestionCallback = QueryRecordOpCallback; q->ResetHandler = QueryRecordOpResetHandler; // For single label queries that are not fully qualified, look at /etc/hosts, cache and try search domains before trying // them on the wire as a single label query. - Mohan if (q->AppendSearchDomains && DomainNameIsSingleLabel(inOp->qname)) q->InterfaceID = mDNSInterface_LocalOnly; err = QueryRecordOpStartQuestion(inOp, q); if (err) goto exit; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(q->InterfaceID, &q->qname, q->flags)) { external_start_browsing_for_service(q->InterfaceID, &q->qname, q->qtype, q->flags, q->pid); } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) if ((RecordTypeIsAddress(q->qtype) || VALID_MSAD_SRV(&inOp->q)) && !q->ForceMCast && SameDomainLabel(LastLabel(&q->qname), (const mDNSu8 *)&localdomain)) { DNSQuestion * q2; q2 = (DNSQuestion *) mDNSPlatformMemAllocate((mDNSu32)sizeof(*inOp->q2)); if (!q2) { err = mStatus_NoMemoryErr; goto exit; } inOp->q2 = q2; *q2 = *q; q2->IsUnicastDotLocal = mDNStrue; if ((CountLabels(&q2->qname) == 2) && !SameDomainName(&q2->qname, &ActiveDirectoryPrimaryDomain) && !DomainNameIsInSearchList(&q2->qname, mDNSfalse)) { inOp->q2Type = q2->qtype; inOp->q2LongLived = q2->LongLived; inOp->q2ReturnIntermed = q2->ReturnIntermed; inOp->q2TimeoutQuestion = q2->TimeoutQuestion; inOp->q2AppendSearchDomains = q2->AppendSearchDomains; AssignDomainName(&q2->qname, &localdomain); q2->qtype = kDNSType_SOA; q2->LongLived = mDNSfalse; q2->ReturnIntermed = mDNStrue; q2->TimeoutQuestion = mDNSfalse; q2->AppendSearchDomains = mDNSfalse; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] QueryRecordOpStart: starting parallel unicast query for " PRI_DM_NAME " " PUB_S, inOp->reqID, DM_NAME_PARAM(&q2->qname), DNSTypeName(q2->qtype)); err = QueryRecordOpStartQuestion(inOp, q2); if (err) goto exit; } #endif err = mStatus_NoError; exit: if (err) QueryRecordOpStop(inOp); return err; } mDNSlocal void QueryRecordOpStop(QueryRecordOp *op) { if (op->q.QuestionContext) { QueryRecordOpStopQuestion(&op->q); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(op->q.InterfaceID, op->qname, op->q.flags)) { external_stop_browsing_for_service(op->q.InterfaceID, &op->q.qname, op->q.qtype, op->q.flags, op->q.pid); } #endif } if (op->qname) { mDNSPlatformMemFree(op->qname); op->qname = mDNSNULL; } #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) if (op->q2) { if (op->q2->QuestionContext) QueryRecordOpStopQuestion(op->q2); mDNSPlatformMemFree(op->q2); op->q2 = mDNSNULL; } #endif } mDNSlocal mDNSBool QueryRecordOpIsMulticast(const QueryRecordOp *op) { return ((mDNSOpaque16IsZero(op->q.TargetQID) && (op->q.ThisQInterval > 0)) ? mDNStrue : mDNSfalse); } // GetTimeNow is a callback-safe alternative to mDNS_TimeNow(), which expects to be called with m->mDNS_busy == 0. mDNSlocal mDNSs32 GetTimeNow(mDNS *m) { mDNSs32 time; mDNS_Lock(m); time = m->timenow; mDNS_Unlock(m); return time; } mDNSlocal void QueryRecordOpCallback(mDNS *m, DNSQuestion *inQuestion, const ResourceRecord *inAnswer, QC_result inAddRecord) { mStatus resultErr; QueryRecordOp *const op = (QueryRecordOp *)inQuestion->QuestionContext; const domainname * domain; #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) if ((inQuestion == op->q2) && (inQuestion->qtype == kDNSType_SOA)) { DNSQuestion * const q2 = op->q2; if (inAnswer->rrtype != kDNSType_SOA) goto exit; QueryRecordOpStopQuestion(q2); // Restore DNSQuestion variables that were modified for the SOA query. q2->qtype = op->q2Type; q2->LongLived = op->q2LongLived; q2->ReturnIntermed = op->q2ReturnIntermed; q2->TimeoutQuestion = op->q2TimeoutQuestion; q2->AppendSearchDomains = op->q2AppendSearchDomains; if (inAnswer->RecordType != kDNSRecordTypePacketNegative) { QueryRecordOpRestartUnicastQuestion(op, q2, mDNSNULL); } else if (q2->AppendSearchDomains) { domain = NextSearchDomain(op); if (domain) QueryRecordOpRestartUnicastQuestion(op, q2, domain); } goto exit; } #endif if (inAddRecord == QC_suppressed) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%u] QueryRecordOpCallback: Suppressed question " PRI_DM_NAME " (" PUB_S ")", op->reqID, DM_NAME_PARAM(&inQuestion->qname), DNSTypeName(inQuestion->qtype)); resultErr = kDNSServiceErr_NoSuchRecord; } else if (inAnswer->RecordType == kDNSRecordTypePacketNegative) { if (inQuestion->TimeoutQuestion && ((GetTimeNow(m) - inQuestion->StopTime) >= 0)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] QueryRecordOpCallback: Question " PRI_DM_NAME " (" PUB_S ") timing out, InterfaceID %p", op->reqID, DM_NAME_PARAM(&inQuestion->qname), DNSTypeName(inQuestion->qtype), inQuestion->InterfaceID); resultErr = kDNSServiceErr_Timeout; } else { if (inQuestion->AppendSearchDomains && (op->searchListIndex >= 0) && inAddRecord) { domain = NextSearchDomain(op); if (domain || DomainNameIsSingleLabel(op->qname)) { QueryRecordOpStopQuestion(inQuestion); QueryRecordOpRestartUnicastQuestion(op, inQuestion, domain); goto exit; } } #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) if (!inAnswer->InterfaceID && IsLocalDomain(inAnswer->name)) { if ((RecordTypeIsAddress(inQuestion->qtype) && (inAnswer->negativeRecordType == kNegativeRecordType_NoData)) || DomainNameIsInSearchList(&inQuestion->qname, mDNStrue)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] QueryRecordOpCallback: Question " PRI_DM_NAME " (" PUB_S ") answering local with negative unicast response", op->reqID, DM_NAME_PARAM(&inQuestion->qname), DNSTypeName(inQuestion->qtype)); } else { goto exit; } } #endif resultErr = kDNSServiceErr_NoSuchRecord; } } else { resultErr = kDNSServiceErr_NoError; } #if MDNSRESPONDER_SUPPORTS(APPLE, REACHABILITY_TRIGGER) if ((resultErr != kDNSServiceErr_Timeout) && (inAddRecord == QC_add)) { op->answered = mDNStrue; } #endif if (op->resultHandler) op->resultHandler(m, inQuestion, inAnswer, inAddRecord, resultErr, op->resultContext); if (resultErr == kDNSServiceErr_Timeout) QueryRecordOpStopQuestion(inQuestion); #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) NotifyWebContentFilter(inAnswer, inQuestion->euid); #endif exit: return; } mDNSlocal void QueryRecordOpResetHandler(DNSQuestion *inQuestion) { QueryRecordOp *const op = (QueryRecordOp *)inQuestion->QuestionContext; AssignDomainName(&inQuestion->qname, op->qname); if (inQuestion->AppendSearchDomains && DomainNameIsSingleLabel(op->qname)) { inQuestion->InterfaceID = mDNSInterface_LocalOnly; } else { inQuestion->InterfaceID = op->interfaceID; } op->searchListIndex = 0; } mDNSlocal mStatus QueryRecordOpStartQuestion(QueryRecordOp *inOp, DNSQuestion *inQuestion) { mStatus err; inQuestion->QuestionContext = inOp; err = mDNS_StartQuery(&mDNSStorage, inQuestion); if (err) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] ERROR: QueryRecordOpStartQuestion mDNS_StartQuery for " PRI_DM_NAME " " PUB_S " failed with error %d", inOp->reqID, DM_NAME_PARAM(&inQuestion->qname), DNSTypeName(inQuestion->qtype), err); inQuestion->QuestionContext = mDNSNULL; } return err; } mDNSlocal mStatus QueryRecordOpStopQuestion(DNSQuestion *inQuestion) { mStatus err; err = mDNS_StopQuery(&mDNSStorage, inQuestion); inQuestion->QuestionContext = mDNSNULL; return err; } mDNSlocal mStatus QueryRecordOpRestartUnicastQuestion(QueryRecordOp *inOp, DNSQuestion *inQuestion, const domainname *inSearchDomain) { mStatus err; inQuestion->InterfaceID = inOp->interfaceID; AssignDomainName(&inQuestion->qname, inOp->qname); if (inSearchDomain) AppendDomainName(&inQuestion->qname, inSearchDomain); if (SameDomainLabel(LastLabel(&inQuestion->qname), (const mDNSu8 *)&localdomain)) { inQuestion->IsUnicastDotLocal = mDNStrue; } else { inQuestion->IsUnicastDotLocal = mDNSfalse; } err = QueryRecordOpStartQuestion(inOp, inQuestion); return err; } mDNSlocal mStatus InterfaceIndexToInterfaceID(mDNSu32 inInterfaceIndex, mDNSInterfaceID *outInterfaceID) { mStatus err; mDNSInterfaceID interfaceID; interfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, inInterfaceIndex); #if MDNSRESPONDER_SUPPORTS(APPLE, UNREADY_INTERFACES) // The request is scoped to a specific interface index, but the interface is not currently in our list. if ((inInterfaceIndex != kDNSServiceInterfaceIndexAny) && (interfaceID == mDNSInterface_Any)) { static dispatch_once_t getLoopbackIndexOnce = 0; static mDNSu32 loopbackIndex = 0; dispatch_once(&getLoopbackIndexOnce, ^{ loopbackIndex = if_nametoindex("lo0"); }); // If it's one of the specially defined inteface index values, just return an error. Also, caller should return an // error immediately if lo0 is not configured into the current active interfaces. See . if ((inInterfaceIndex == kDNSServiceInterfaceIndexLocalOnly) || (inInterfaceIndex == kDNSServiceInterfaceIndexUnicast) || (inInterfaceIndex == kDNSServiceInterfaceIndexP2P) || (inInterfaceIndex == kDNSServiceInterfaceIndexBLE) || (inInterfaceIndex == loopbackIndex)) { LogInfo("ERROR: bad interfaceIndex %d", inInterfaceIndex); err = mStatus_BadParamErr; goto exit; } // Otherwise, use the specified interface index value and the request will be applied to that interface when it // comes up. interfaceID = (mDNSInterfaceID)(uintptr_t)inInterfaceIndex; LogInfo("Query pending for interface index %d", inInterfaceIndex); } #endif *outInterfaceID = interfaceID; err = mStatus_NoError; #if MDNSRESPONDER_SUPPORTS(APPLE, UNREADY_INTERFACES) exit: #endif return err; } mDNSlocal mDNSBool DomainNameIsSingleLabel(const domainname *inName) { const mDNSu8 *const label = inName->c; return (((label[0] != 0) && (label[1 + label[0]] == 0)) ? mDNStrue : mDNSfalse); } mDNSlocal mDNSBool StringEndsWithDot(const char *inString) { const char * ptr; mDNSu32 escapeCount; mDNSBool result; // Loop invariant: escapeCount is the number of consecutive escape characters that immediately precede *ptr. // - If escapeCount is even, then *ptr is immediately preceded by escapeCount / 2 consecutive literal backslash // characters, so *ptr is not escaped. // - If escapeCount is odd, then *ptr is immediately preceded by (escapeCount - 1) / 2 consecutive literal backslash // characters followed by an escape character, so *ptr is escaped. escapeCount = 0; result = mDNSfalse; for (ptr = inString; *ptr != '\0'; ptr++) { if (*ptr == '\\') { escapeCount++; } else { if ((*ptr == '.') && (ptr[1] == '\0')) { if ((escapeCount % 2) == 0) result = mDNStrue; break; } escapeCount = 0; } } return result; } mDNSlocal const domainname * NextSearchDomain(QueryRecordOp *inOp) { const domainname * domain; while ((domain = uDNS_GetNextSearchDomain(inOp->interfaceID, &inOp->searchListIndex, mDNSfalse)) != mDNSNULL) { if ((DomainNameLength(inOp->qname) - 1 + DomainNameLength(domain)) <= MAX_DOMAIN_NAME) break; } if (!domain) inOp->searchListIndex = -1; return domain; } #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) mDNSlocal mDNSBool DomainNameIsInSearchList(const domainname *inName, mDNSBool inExcludeLocal) { const SearchListElem * item; int labelCount, domainLabelCount; labelCount = CountLabels(inName); for (item = SearchList; item; item = item->next) { if (inExcludeLocal && SameDomainName(&item->domain, &localdomain)) continue; domainLabelCount = CountLabels(&item->domain); if (labelCount >= domainLabelCount) { if (SameDomainName(&item->domain, SkipLeadingLabels(inName, (labelCount - domainLabelCount)))) { return mDNStrue; } } } return mDNSfalse; } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, WEB_CONTENT_FILTER) mDNSlocal void NotifyWebContentFilter(const ResourceRecord *inAnswer, uid_t inUID) { if (WCFIsServerRunning) { const mDNS *const m = &mDNSStorage; if (WCFIsServerRunning(m->WCF) && inAnswer->rdlength != 0) { struct sockaddr_storage addr; addr.ss_len = 0; if (inAnswer->rrtype == kDNSType_A || inAnswer->rrtype == kDNSType_AAAA) { if (inAnswer->rrtype == kDNSType_A) { struct sockaddr_in *const sin = (struct sockaddr_in *)&addr; sin->sin_port = 0; // Instead of this stupid call to putRData it would be much simpler to just assign the value in the sensible way, like this: // sin->sin_addr.s_addr = inAnswer->rdata->u.ipv4.NotAnInteger; if (!putRData(mDNSNULL, (mDNSu8 *)&sin->sin_addr, (mDNSu8 *)(&sin->sin_addr + sizeof(mDNSv4Addr)), inAnswer)) LogMsg("NotifyWebContentFilter: WCF AF_INET putRData failed"); else { addr.ss_len = sizeof (struct sockaddr_in); addr.ss_family = AF_INET; } } else if (inAnswer->rrtype == kDNSType_AAAA) { struct sockaddr_in6 *const sin6 = (struct sockaddr_in6 *)&addr; sin6->sin6_port = 0; // Instead of this stupid call to putRData it would be much simpler to just assign the value in the sensible way, like this: // sin6->sin6_addr.__u6_addr.__u6_addr32[0] = inAnswer->rdata->u.ipv6.l[0]; // sin6->sin6_addr.__u6_addr.__u6_addr32[1] = inAnswer->rdata->u.ipv6.l[1]; // sin6->sin6_addr.__u6_addr.__u6_addr32[2] = inAnswer->rdata->u.ipv6.l[2]; // sin6->sin6_addr.__u6_addr.__u6_addr32[3] = inAnswer->rdata->u.ipv6.l[3]; if (!putRData(mDNSNULL, (mDNSu8 *)&sin6->sin6_addr, (mDNSu8 *)(&sin6->sin6_addr + sizeof(mDNSv6Addr)), inAnswer)) LogMsg("NotifyWebContentFilter: WCF AF_INET6 putRData failed"); else { addr.ss_len = sizeof (struct sockaddr_in6); addr.ss_family = AF_INET6; } } if (addr.ss_len) { char name[MAX_ESCAPED_DOMAIN_NAME]; ConvertDomainNameToCString(inAnswer->name, name); debugf("NotifyWebContentFilter: Name %s, uid %u, addr length %d", name, inUID, addr.ss_len); if (WCFNameResolvesToAddr) { WCFNameResolvesToAddr(m->WCF, name, (struct sockaddr *)&addr, inUID); } } } else if (inAnswer->rrtype == kDNSType_CNAME) { domainname cname; char name[MAX_ESCAPED_DOMAIN_NAME]; char cname_cstr[MAX_ESCAPED_DOMAIN_NAME]; if (!putRData(mDNSNULL, cname.c, (mDNSu8 *)(cname.c + MAX_DOMAIN_NAME), inAnswer)) LogMsg("NotifyWebContentFilter: WCF CNAME putRData failed"); else { ConvertDomainNameToCString(inAnswer->name, name); ConvertDomainNameToCString(&cname, cname_cstr); if (WCFNameResolvesToAddr) { WCFNameResolvesToName(m->WCF, name, cname_cstr, inUID); } } } } } } #endif /* * Copyright (c) 2018-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __ClientRequests_h #define __ClientRequests_h #include "mDNSEmbeddedAPI.h" #include "dns_sd_internal.h" typedef void (*QueryRecordResultHandler)(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord, DNSServiceErrorType error, void *context); typedef struct { DNSQuestion q; // DNSQuestion for record query. domainname * qname; // Name of the original record. mDNSInterfaceID interfaceID; // Interface over which to perform query. QueryRecordResultHandler resultHandler; // Handler for query record operation results. void * resultContext; // Context to pass to result handler. mDNSu32 reqID; // int searchListIndex; // Index that indicates the next search domain to try. #if MDNSRESPONDER_SUPPORTS(APPLE, UNICAST_DOTLOCAL) DNSQuestion * q2; // DNSQuestion for unicast version of a record with a dot-local name. mDNSu16 q2Type; // q2's original qtype value. mDNSBool q2LongLived; // q2's original LongLived value. mDNSBool q2ReturnIntermed; // q2's original ReturnIntermed value. mDNSBool q2TimeoutQuestion; // q2's original TimeoutQuestion value. mDNSBool q2AppendSearchDomains; // q2's original AppendSearchDomains value. #endif #if MDNSRESPONDER_SUPPORTS(APPLE, REACHABILITY_TRIGGER) mDNSBool answered; // True if the query was answered. #endif } QueryRecordOp; typedef struct { mDNSInterfaceID interfaceID; // InterfaceID being used for query record operations. mDNSu32 protocols; // Protocols (IPv4, IPv6) specified by client. QueryRecordOp * op4; // Query record operation object for A record. QueryRecordOp * op6; // Query record operation object for AAAA record. } GetAddrInfoClientRequest; typedef struct { QueryRecordOp op; // Query record operation object. } QueryRecordClientRequest; typedef struct { mDNSu32 requestID; const char * hostnameStr; mDNSu32 interfaceIndex; DNSServiceFlags flags; mDNSu32 protocols; mDNSs32 effectivePID; const mDNSu8 * effectiveUUID; mDNSu32 peerUID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool needEncryption; const mDNSu8 * resolverUUID; mdns_dns_service_id_t customID; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) const audit_token_t * peerAuditToken; const audit_token_t * delegatorAuditToken; mDNSBool isInAppBrowserRequest; #endif } GetAddrInfoClientRequestParams; typedef struct { mDNSu32 requestID; const char * qnameStr; mDNSu32 interfaceIndex; DNSServiceFlags flags; mDNSu16 qtype; mDNSu16 qclass; mDNSs32 effectivePID; const mDNSu8 * effectiveUUID; mDNSu32 peerUID; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool needEncryption; const mDNSu8 * resolverUUID; mdns_dns_service_id_t customID; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) const audit_token_t * peerAuditToken; const audit_token_t * delegatorAuditToken; mDNSBool isInAppBrowserRequest; #endif } QueryRecordClientRequestParams; #ifdef __cplusplus extern "C" { #endif mDNSexport void GetAddrInfoClientRequestParamsInit(GetAddrInfoClientRequestParams *inParams); mDNSexport mStatus GetAddrInfoClientRequestStart(GetAddrInfoClientRequest *inRequest, const GetAddrInfoClientRequestParams *inParams, QueryRecordResultHandler inResultHandler, void *inResultContext); mDNSexport void GetAddrInfoClientRequestStop(GetAddrInfoClientRequest *inRequest); mDNSexport const domainname * GetAddrInfoClientRequestGetQName(const GetAddrInfoClientRequest *inRequest); mDNSexport mDNSBool GetAddrInfoClientRequestIsMulticast(const GetAddrInfoClientRequest *inRequest); mDNSexport void QueryRecordClientRequestParamsInit(QueryRecordClientRequestParams *inParams); mDNSexport mStatus QueryRecordClientRequestStart(QueryRecordClientRequest *inRequest, const QueryRecordClientRequestParams *inParams, QueryRecordResultHandler inResultHandler, void *inResultContext); mDNSexport void QueryRecordClientRequestStop(QueryRecordClientRequest *inRequest); mDNSexport const domainname * QueryRecordClientRequestGetQName(const QueryRecordClientRequest *inRequest); mDNSexport mDNSu16 QueryRecordClientRequestGetType(const QueryRecordClientRequest *inRequest); mDNSexport mDNSBool QueryRecordClientRequestIsMulticast(QueryRecordClientRequest *inRequest); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) // This is a "mDNSexport" wrapper around the "static" QueryRecordOpStart that cannot be called by outside, which can be // called by the outside(dnssec related function). mDNSexport mStatus QueryRecordOpStartForClientRequest( QueryRecordOp * inOp, mDNSu32 inReqID, const domainname * inQName, mDNSu16 inQType, mDNSu16 inQClass, mDNSInterfaceID inInterfaceID, mDNSs32 inServiceID, mDNSu32 inFlags, mDNSBool inAppendSearchDomains, mDNSs32 inPID, const mDNSu8 inUUID[UUID_SIZE], mDNSu32 inUID, #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) const audit_token_t * inPeerAuditTokenPtr, const audit_token_t * inDelegateAuditTokenPtr, #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) const mDNSu8 inResolverUUID[UUID_SIZE], mDNSBool inNeedEncryption, const mdns_dns_service_id_t inCustomID, #endif QueryRecordResultHandler inResultHandler, void * inResultContext); mDNSexport void QueryRecordOpStopForClientRequest(QueryRecordOp *op); #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #ifdef __cplusplus } #endif #endif // __ClientRequests_h /* * Copyright (c) 2003-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "GenLinkedList.h" // Return the link pointer contained within element e at offset o. #define GETLINK( e, o) ( *(void**)((char*) (e) + (o)) ) // Assign the link pointer l to element e at offset o. #define ASSIGNLINK( e, l, o) ( *((void**)((char*) (e) + (o))) = (l)) // GenLinkedList ///////////////////////////////////////////////////////////// void InitLinkedList( GenLinkedList *pList, size_t linkOffset) /* Initialize the block of memory pointed to by pList as a linked list. */ { pList->Head = NULL; pList->Tail = NULL; pList->LinkOffset = linkOffset; } void AddToTail( GenLinkedList *pList, void *elem) /* Add a linked list element to the tail of the list. */ { if ( pList->Tail) { ASSIGNLINK( pList->Tail, elem, pList->LinkOffset); } else pList->Head = elem; ASSIGNLINK( elem, NULL, pList->LinkOffset); pList->Tail = elem; } void AddToHead( GenLinkedList *pList, void *elem) /* Add a linked list element to the head of the list. */ { ASSIGNLINK( elem, pList->Head, pList->LinkOffset); if ( pList->Tail == NULL) pList->Tail = elem; pList->Head = elem; } int RemoveFromList( GenLinkedList *pList, void *elem) /* Remove a linked list element from the list. Return 0 if it was not found. */ /* If the element is removed, its link will be set to NULL. */ { void *iElem, *lastElem; for ( iElem = pList->Head, lastElem = NULL; iElem; iElem = GETLINK( iElem, pList->LinkOffset)) { if ( iElem == elem) { if ( lastElem) { // somewhere past the head ASSIGNLINK( lastElem, GETLINK( elem, pList->LinkOffset), pList->LinkOffset); } else { // at the head pList->Head = GETLINK( elem, pList->LinkOffset); } if ( pList->Tail == elem) pList->Tail = lastElem ? lastElem : NULL; ASSIGNLINK( elem, NULL, pList->LinkOffset); // maybe catch a stale reference bug. return 1; } lastElem = iElem; } return 0; } int ReplaceElem( GenLinkedList *pList, void *elemInList, void *newElem) /* Replace an element in the list with a new element, in the same position. */ { void *iElem, *lastElem; if ( elemInList == NULL || newElem == NULL) return 0; for ( iElem = pList->Head, lastElem = NULL; iElem; iElem = GETLINK( iElem, pList->LinkOffset)) { if ( iElem == elemInList) { ASSIGNLINK( newElem, GETLINK( elemInList, pList->LinkOffset), pList->LinkOffset); if ( lastElem) // somewhere past the head { ASSIGNLINK( lastElem, newElem, pList->LinkOffset); } else // at the head { pList->Head = newElem; } if ( pList->Tail == elemInList) pList->Tail = newElem; return 1; } lastElem = iElem; } return 0; } // GenDoubleLinkedList ///////////////////////////////////////////////////////// void InitDoubleLinkedList( GenDoubleLinkedList *pList, size_t fwdLinkOffset, size_t backLinkOffset) /* Initialize the block of memory pointed to by pList as a double linked list. */ { pList->Head = NULL; pList->Tail = NULL; pList->FwdLinkOffset = fwdLinkOffset; pList->BackLinkOffset = backLinkOffset; } void DLLAddToHead( GenDoubleLinkedList *pList, void *elem) /* Add a linked list element to the head of the list. */ { void *pNext; pNext = pList->Head; // fix up the forward links ASSIGNLINK( elem, pList->Head, pList->FwdLinkOffset); pList->Head = elem; // fix up the backward links if ( pNext) { ASSIGNLINK( pNext, elem, pList->BackLinkOffset); } else pList->Tail = elem; ASSIGNLINK( elem, NULL, pList->BackLinkOffset); } void DLLRemoveFromList( GenDoubleLinkedList *pList, void *elem) /* Remove a linked list element from the list. */ /* When the element is removed, its link will be set to NULL. */ { void *pNext, *pPrev; pNext = GETLINK( elem, pList->FwdLinkOffset); pPrev = GETLINK( elem, pList->BackLinkOffset); // fix up the forward links if ( pPrev) ASSIGNLINK( pPrev, pNext, pList->FwdLinkOffset); else pList->Head = pNext; // fix up the backward links if ( pNext) ASSIGNLINK( pNext, pPrev, pList->BackLinkOffset); else pList->Tail = pPrev; ASSIGNLINK( elem, NULL, pList->FwdLinkOffset); ASSIGNLINK( elem, NULL, pList->BackLinkOffset); } // GenLinkedOffsetList ///////////////////////////////////////////////////// // Extract the Next offset from element #define GETOFFSET( e, o) ( *(size_t*)((char*) (e) + (o)) ) static void AssignOffsetLink( void *elem, void *link, size_t linkOffset); static void AssignOffsetLink( void *elem, void *link, size_t linkOffset) // Assign link to elem as an offset from elem. Assign 0 to elem if link is NULL. { GETOFFSET( elem, linkOffset) = link ? (size_t) link - (size_t) elem : 0; } void *GetHeadPtr( GenLinkedOffsetList *pList) /* Return a pointer to the head element of a list, or NULL if none. */ { return pList->Head ? ( (char*) (pList) + pList->Head) : NULL; } void *GetTailPtr( GenLinkedOffsetList *pList) /* Return a pointer to the tail element of a list, or NULL if none. */ { return pList->Tail ? ( (char*) (pList) + pList->Tail) : NULL; } void *GetOffsetLink( GenLinkedOffsetList *pList, void *elem) /* Return the link pointer contained within element e for pList, or NULL if it is 0. */ { size_t nextOffset; nextOffset = GETOFFSET( elem, pList->LinkOffset); return nextOffset ? (char*) elem + nextOffset : NULL; } void InitLinkedOffsetList( GenLinkedOffsetList *pList, size_t linkOffset) /* Initialize the block of memory pointed to by pList as a linked list. */ { pList->Head = 0; pList->Tail = 0; pList->LinkOffset = linkOffset; } void OffsetAddToTail( GenLinkedOffsetList *pList, void *elem) /* Add a linked list element to the tail of the list. */ { if ( pList->Tail) { AssignOffsetLink( GetTailPtr( pList), elem, pList->LinkOffset); } else pList->Head = (size_t) elem - (size_t) pList; AssignOffsetLink( elem, NULL, pList->LinkOffset); pList->Tail = (size_t) elem - (size_t) pList; } void OffsetAddToHead( GenLinkedOffsetList *pList, void *elem) /* Add a linked list element to the head of the list. */ { AssignOffsetLink( elem, GetHeadPtr( pList), pList->LinkOffset); if ( pList->Tail == 0) pList->Tail = (size_t) elem - (size_t) pList; pList->Head = (size_t) elem - (size_t) pList; } int OffsetRemoveFromList( GenLinkedOffsetList *pList, void *elem) /* Remove a linked list element from the list. Return 0 if it was not found. */ /* If the element is removed, its link will be set to NULL. */ { void *iElem, *lastElem; if (elem == NULL) { return 0; } for ( iElem = GetHeadPtr( pList), lastElem = NULL; iElem; iElem = GetOffsetLink( pList, iElem)) { if ( iElem == elem) { if ( lastElem) { // somewhere past the head AssignOffsetLink( lastElem, GetOffsetLink( pList, elem), pList->LinkOffset); } else { // at the head iElem = GetOffsetLink( pList, elem); pList->Head = iElem ? (size_t) iElem - (size_t) pList : 0; } if ( GetTailPtr( pList) == elem) pList->Tail = lastElem ? (size_t) lastElem - (size_t) pList : 0; AssignOffsetLink( elem, NULL, pList->LinkOffset); // maybe catch a stale reference bug. return 1; } lastElem = iElem; } return 0; } int OffsetReplaceElem( GenLinkedOffsetList *pList, void *elemInList, void *newElem) /* Replace an element in the list with a new element, in the same position. */ { void *iElem, *lastElem; if ( elemInList == NULL || newElem == NULL) return 0; for ( iElem = GetHeadPtr( pList), lastElem = NULL; iElem; iElem = GetOffsetLink( pList, iElem)) { if ( iElem == elemInList) { AssignOffsetLink( newElem, GetOffsetLink( pList, elemInList), pList->LinkOffset); if ( lastElem) // somewhere past the head { AssignOffsetLink( lastElem, newElem, pList->LinkOffset); } else // at the head { pList->Head = (size_t) newElem - (size_t) pList; } if ( GetTailPtr( pList) == elemInList) pList->Tail = (size_t) newElem - (size_t) pList; return 1; } lastElem = iElem; } return 0; } /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2003 Apple Computer, Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __GenLinkedList__ #define __GenLinkedList__ #include struct GenLinkedList { void *Head, *Tail; size_t LinkOffset; }; typedef struct GenLinkedList GenLinkedList; void InitLinkedList( GenLinkedList *pList, size_t linkOffset); void AddToHead( GenLinkedList *pList, void *elem); void AddToTail( GenLinkedList *pList, void *elem); int RemoveFromList( GenLinkedList *pList, void *elem); int ReplaceElem( GenLinkedList *pList, void *elemInList, void *newElem); struct GenDoubleLinkedList { void *Head, *Tail; size_t FwdLinkOffset, BackLinkOffset; }; typedef struct GenDoubleLinkedList GenDoubleLinkedList; void InitDoubleLinkedList( GenDoubleLinkedList *pList, size_t fwdLinkOffset, size_t backLinkOffset); void DLLAddToHead( GenDoubleLinkedList *pList, void *elem); void DLLRemoveFromList( GenDoubleLinkedList *pList, void *elem); /* A GenLinkedOffsetList is like a GenLinkedList that stores the *Next field as a signed */ /* offset from the address of the beginning of the element, rather than as a pointer. */ struct GenLinkedOffsetList { size_t Head, Tail; size_t LinkOffset; }; typedef struct GenLinkedOffsetList GenLinkedOffsetList; void InitLinkedOffsetList( GenLinkedOffsetList *pList, size_t linkOffset); void *GetHeadPtr( GenLinkedOffsetList *pList); void *GetTailPtr( GenLinkedOffsetList *pList); void *GetOffsetLink( GenLinkedOffsetList *pList, void *elem); void OffsetAddToHead( GenLinkedOffsetList *pList, void *elem); void OffsetAddToTail( GenLinkedOffsetList *pList, void *elem); int OffsetRemoveFromList( GenLinkedOffsetList *pList, void *elem); int OffsetReplaceElem( GenLinkedOffsetList *pList, void *elemInList, void *newElem); #endif // __GenLinkedList__ /* -*- Mode: C; tab-width: 4; c-file-style: "bsd"; c-basic-offset: 4; fill-column: 108; indent-tabs-mode: nil; -*- * * Copyright (c) 2004-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * This file defines functions that are common to platforms with Posix APIs. * Current examples are mDNSMacOSX and mDNSPosix. */ #include // Needed for fopen() etc. #include // Needed for close() #include // Needed for malloc() #include // Needed for strlen() etc. #include // Needed for errno etc. #include // Needed for socket() etc. #include // Needed for sockaddr_in #include #include #include #include #include #if APPLE_OSX_mDNSResponder #include #endif #include "mDNSEmbeddedAPI.h" // Defines the interface provided to the client layer above #include "DNSCommon.h" #include "PlatformCommon.h" #ifdef NOT_HAVE_SOCKLEN_T typedef unsigned int socklen_t; #endif #if MDNS_MALLOC_DEBUGGING // We ONLY want this for malloc debugging--on a running production system we want to deal with // malloc failures, not just die. There is a small performance penalty for enabling these options // as well, so they are all only appropriate for debugging. The flags mean: // // A = warnings are errors // X = abort on failure // Z = sets J & R // J = allocated memory is initialized to a pattern // R causes realloc to always reallocate even if not needed char _malloc_options[] = "AXZ"; mDNSlocal mDNSListValidator *listValidators; mDNSexport void mDNSPlatformAddListValidator(mDNSListValidator *lv, mDNSListValidationFunction *lvf, const char *lvfName, void *context) { mDNSPlatformMemZero(lv, sizeof *lv); lv->validator = lvf; lv->validationFunctionName = lvfName; lv->context = context; lv->next = listValidators; listValidators = lv; } mDNSlocal void validateLists(void) { mDNSListValidator *vfp; // Check Unix Domain Socket client lists (uds_daemon.c) for (vfp = listValidators; vfp; vfp = vfp->next) { vfp->validator(vfp->context); } mDNSPlatformValidateLists(); } #define kAllocMagic 0xDEAD1234 #define kGuardMagic 0xDEAD1234 #define kFreeMagic 0xDEADDEAD #define kAllocLargeSize 32768 mDNSexport void *mallocL(const char *msg, mDNSu32 size) { // Allocate space for two words of sanity checking data before the requested block and two words after. // Adjust the length for alignment. mDNSu32 *mem = malloc(sizeof(mDNSu32) * 4 + size); mDNSu32 guard[2]; if (!mem) { LogMsg("malloc( %s : %u ) failed", msg, size); return(NULL); } else { mDNSu32 *after = (mDNSu32 *)((mDNSu8 *)(mem + 2) + size); if (size > kAllocLargeSize) LogMsg("malloc( %s : %lu ) @ %p suspiciously large", msg, size, &mem[2]); else if (MDNS_MALLOC_DEBUGGING >= 2) LogMsg("malloc( %s : %lu ) @ %p", msg, size, &mem[2]); mem[ 0] = kAllocMagic; guard[0] = kGuardMagic; mem[ 1] = size; guard[1] = size; memcpy(after, &guard, sizeof guard); memset(&mem[2], 0xFF, size); validateLists(); return(&mem[2]); } } mDNSexport void *callocL(const char *msg, mDNSu32 size) { mDNSu32 guard[2]; const mDNSu32 headerSize = 4 * sizeof(mDNSu32); // Allocate space for two words of sanity checking data before the requested block and two words after. // Adjust the length for alignment. mDNSu32 *mem = (mDNSu32 *)calloc(1, headerSize + size); if (!mem) { LogMsg("calloc( %s : %u ) failed", msg, size); return(NULL); } else { mDNSu32 *after = (mDNSu32 *)((mDNSu8 *)(mem + 2) + size); if (size > kAllocLargeSize) LogMsg("calloc( %s : %lu ) @ %p suspiciously large", msg, size, &mem[2]); else if (MDNS_MALLOC_DEBUGGING >= 2) LogMsg("calloc( %s : %lu ) @ %p", msg, size, &mem[2]); mem[ 0] = kAllocMagic; guard[0] = kGuardMagic; mem[ 1] = size; guard[1] = size; memcpy(after, guard, sizeof guard); validateLists(); return(&mem[2]); } } mDNSexport void freeL(const char *msg, void *x) { if (!x) LogMsg("free( %s @ NULL )!", msg); else { mDNSu32 *mem = ((mDNSu32 *)x) - 2; if (mem[0] == kFreeMagic) { LogMemCorruption("free( %s : %lu @ %p ) !!!! ALREADY DISPOSED !!!!", msg, mem[1], &mem[2]); return; } if (mem[0] != kAllocMagic) { LogMemCorruption("free( %s : %lu @ %p ) !!!! NEVER ALLOCATED !!!!", msg, mem[1], &mem[2]); return; } if (mem[1] > kAllocLargeSize) LogMsg("free( %s : %lu @ %p) suspiciously large", msg, mem[1], &mem[2]); else if (MDNS_MALLOC_DEBUGGING >= 2) LogMsg("free( %s : %ld @ %p)", msg, mem[1], &mem[2]); mDNSu32 *after = (mDNSu32 *)((mDNSu8 *)x + mem[1]); mDNSu32 guard[2]; memcpy(guard, after, sizeof guard); if (guard[0] != kGuardMagic) { LogMemCorruption("free( %s : %lu @ %p ) !!!! END GUARD OVERWRITE !!!!", msg, mem[1], &mem[2]); return; } if (guard[1] != mem[1]) { LogMemCorruption("free( %s : %lu @ %p ) !!!! LENGTH MISMATCH !!!!", msg, mem[1], &mem[2]); return; } mem[0] = kFreeMagic; memset(mem + 2, 0xFF, mem[1] + 2 * sizeof(mDNSu32)); validateLists(); free(mem); } } #endif // Bind a UDP socket to find the source address to a destination mDNSexport void mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst) { union { struct sockaddr s; struct sockaddr_in a4; struct sockaddr_in6 a6; } addr; socklen_t len = sizeof(addr); socklen_t inner_len = 0; int sock = socket(AF_INET, SOCK_DGRAM, 0); src->type = mDNSAddrType_None; if (sock == -1) return; if (dst->type == mDNSAddrType_IPv4) { inner_len = sizeof(addr.a4); #ifndef NOT_HAVE_SA_LEN addr.a4.sin_len = inner_len; #endif addr.a4.sin_family = AF_INET; addr.a4.sin_port = 1; // Not important, any port will do addr.a4.sin_addr.s_addr = dst->ip.v4.NotAnInteger; } else if (dst->type == mDNSAddrType_IPv6) { inner_len = sizeof(addr.a6); #ifndef NOT_HAVE_SA_LEN addr.a6.sin6_len = inner_len; #endif addr.a6.sin6_family = AF_INET6; addr.a6.sin6_flowinfo = 0; addr.a6.sin6_port = 1; // Not important, any port will do addr.a6.sin6_addr = *(struct in6_addr*)&dst->ip.v6; addr.a6.sin6_scope_id = 0; } else return; if ((connect(sock, &addr.s, inner_len)) < 0) { if (errno != ENETUNREACH) LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno, strerror(errno)); goto exit; } if ((getsockname(sock, &addr.s, &len)) < 0) { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; } src->type = dst->type; if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr; else src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr; exit: close(sock); } // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f) { char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value size_t len = strlen(option); if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; } fseek(f, 0, SEEK_SET); // set position to beginning of stream while (fgets(buf, sizeof(buf), f)) // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator { if (!strncmp(buf, option, len)) { strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1); if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0'; len = strlen(dst); if (len && dst[len-1] == '\n') dst[len-1] = '\0'; // chop newline return mDNStrue; } } debugf("Option %s not set", option); return mDNSfalse; } mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled) { char buf[MAX_ESCAPED_DOMAIN_NAME] = ""; mStatus err; FILE *f = fopen(filename, "r"); if (hostname) hostname->c[0] = 0; if (domain) domain->c[0] = 0; if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse; if (f) { if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue; if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf; if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf; buf[0] = 0; GetConfigOption(buf, "secret-64", f); // failure means no authentication fclose(f); f = NULL; } else { if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened."); return; } if (domain && domain->c[0] && buf[0]) { DomainAuthInfo *info = (DomainAuthInfo*) mDNSPlatformMemAllocateClear(sizeof(*info)); // for now we assume keyname = service reg domain and we use same key for service and hostname registration err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, NULL, 0); if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c); } return; badf: LogMsg("ERROR: malformatted config file"); if (f) fclose(f); } #if MDNS_DEBUGMSGS mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg) { fprintf(stderr,"%s\n", msg); fflush(stderr); } #endif #if !MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, mDNSLogLevel_t loglevel) { #if APPLE_OSX_mDNSResponder && LogTimeStamps extern mDNS mDNSStorage; extern mDNSu32 mDNSPlatformClockDivisor; mDNSs32 t = mDNSStorage.timenow ? mDNSStorage.timenow : mDNSPlatformClockDivisor ? mDNS_TimeNow_NoLock(&mDNSStorage) : 0; int ms = ((t < 0) ? -t : t) % 1000; #endif if (mDNS_DebugMode) // In debug mode we write to stderr { #if APPLE_OSX_mDNSResponder && LogTimeStamps if (ident && ident[0] && mDNSPlatformClockDivisor) fprintf(stderr,"%8d.%03d: %s\n", (int)(t/1000), ms, buffer); else #endif fprintf(stderr,"%s\n", buffer); fflush(stderr); } else // else, in production mode, we write to syslog { static int log_inited = 0; int syslog_level; switch (loglevel) { case MDNS_LOG_FAULT: syslog_level = LOG_ERR; break; case MDNS_LOG_ERROR: syslog_level = LOG_ERR; break; case MDNS_LOG_WARNING: syslog_level = LOG_WARNING; break; case MDNS_LOG_DEFAULT: syslog_level = LOG_NOTICE; break; case MDNS_LOG_INFO: syslog_level = LOG_INFO; break; case MDNS_LOG_DEBUG: syslog_level = LOG_DEBUG; break; default: syslog_level = LOG_NOTICE; break; } if (!log_inited) { openlog(ident, LOG_CONS, LOG_DAEMON); log_inited++; } #if APPLE_OSX_mDNSResponder && LogTimeStamps if (ident && ident[0] && mDNSPlatformClockDivisor) syslog(syslog_level, "%8d.%03d: %s", (int)(t/1000), ms, buffer); else #endif { syslog(syslog_level, "%s", buffer); } } } #endif // !MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) mDNSexport mDNSBool mDNSPosixTCPSocketSetup(int *fd, mDNSAddr_Type addrType, mDNSIPPort *port, mDNSIPPort *outTcpPort) { int sa_family = (addrType == mDNSAddrType_IPv4) ? AF_INET : AF_INET6; int err; int sock; mDNSu32 lowWater = 15384; sock = socket(sa_family, SOCK_STREAM, IPPROTO_TCP); if (sock < 3) { if (errno != EAFNOSUPPORT) { LogMsg("mDNSPosixTCPSocketSetup: socket error %d errno %d (%s)", sock, errno, strerror(errno)); } return mDNStrue; } *fd = sock; union { struct sockaddr sa; struct sockaddr_in sin; struct sockaddr_in6 sin6; } addr; // If port is not NULL, bind to it. if (port != NULL) { socklen_t len = (sa_family == AF_INET) ? sizeof (struct sockaddr_in) : sizeof (struct sockaddr_in6); mDNSPlatformMemZero(&addr, sizeof addr); addr.sa.sa_family = sa_family; #ifndef NOT_HAVE_SA_LEN addr.sa.sa_len = len; #endif if (sa_family == AF_INET6) { addr.sin6.sin6_port = port->NotAnInteger; } else { addr.sin.sin_port = port->NotAnInteger; } err = bind(sock, &addr.sa, len); if (err < 0) { LogMsg("mDNSPosixTCPSocketSetup getsockname: %s", strerror(errno)); return mDNSfalse; } } socklen_t addrlen = sizeof addr; err = getsockname(sock, (struct sockaddr *)&addr, &addrlen); if (err < 0) { LogMsg("mDNSPosixTCPSocketSetup getsockname: %s", strerror(errno)); return mDNSfalse; } if (sa_family == AF_INET6) { outTcpPort->NotAnInteger = addr.sin6.sin6_port; } else { outTcpPort->NotAnInteger = addr.sin.sin_port; } if (port) port->NotAnInteger = outTcpPort->NotAnInteger; #ifdef TCP_NOTSENT_LOWAT err = setsockopt(sock, IPPROTO_TCP, TCP_NOTSENT_LOWAT, &lowWater, sizeof lowWater); if (err < 0) { LogMsg("mDNSPosixTCPSocketSetup: TCP_NOTSENT_LOWAT failed: %s", strerror(errno)); return mDNSfalse; } #endif return mDNStrue; } mDNSexport TCPSocket *mDNSPosixDoTCPListenCallback(int fd, mDNSAddr_Type addressType, TCPSocketFlags socketFlags, TCPAcceptedCallback callback, void *context) { union { struct sockaddr_in6 sin6; struct sockaddr_in sin; struct sockaddr sa; } address; socklen_t slen = sizeof address; int remoteSock; mDNSAddr addr; mDNSIPPort port; TCPSocket *sock = mDNSNULL; int failed; char *nbp; int i; mDNSu32 lowWater = 16384; // When we remember our connection, we remember a name that we can print for logging. But // since we are the listener in this case, we don't /have/ a name for it. This buffer // is used to print the IP address into a human readable string which will serve that purpose // for this case. char namebuf[INET6_ADDRSTRLEN + 1 + 5 + 1]; remoteSock = accept(fd, &address.sa, &slen); if (remoteSock < 0) { LogMsg("mDNSPosixDoTCPListenCallback: accept returned %d", remoteSock); goto out; } failed = fcntl(remoteSock, F_SETFL, O_NONBLOCK); if (failed < 0) { close(remoteSock); LogMsg("mDNSPosixDoTCPListenCallback: fcntl returned %d", errno); goto out; } #ifdef TCP_NOTSENT_LOWAT failed = setsockopt(remoteSock, IPPROTO_TCP, TCP_NOTSENT_LOWAT, &lowWater, sizeof lowWater); if (failed < 0) { close(remoteSock); LogMsg("mDNSPosixDoTCPListenCallback: TCP_NOTSENT_LOWAT returned %d", errno); goto out; } #endif if (address.sa.sa_family == AF_INET6) { // If we are listening on an IPv4/IPv6 socket, the incoming address might be an IPv4-in-IPv6 address for (i = 0; i < 10; i++) { if (address.sin6.sin6_addr.s6_addr[i] != 0) { addr.type = mDNSAddrType_IPv6; goto nope; } } // a legit IPv4 address would be ::ffff:a.b.c.d; if there's no ::ffff bit, then it's an IPv6 // address with a really weird prefix. if (address.sin6.sin6_addr.s6_addr[10] != 0xFF || address.sin6.sin6_addr.s6_addr[11] != 0xFF) { addr.type = mDNSAddrType_IPv6; } else if (addressType != mDNSAddrType_None) { if (inet_ntop(AF_INET, &address.sin6.sin6_addr.s6_addr[12], namebuf, INET6_ADDRSTRLEN + 1) == NULL) { strcpy(namebuf, ":unknown:"); } LogMsg("mDNSPosixDoTCPListenCallback received an IPv4 connection from %s on an IPv6-only socket.", namebuf); close(remoteSock); goto out; } else { addr.type = mDNSAddrType_IPv4; } nope: if (addr.type == mDNSAddrType_IPv6) { if (inet_ntop(address.sin6.sin6_family, &address.sin6.sin6_addr, namebuf, INET6_ADDRSTRLEN + 1) == NULL) { strcpy(namebuf, ":unknown:"); } memcpy(&addr.ip.v6, &address.sin6.sin6_addr, sizeof addr.ip.v6); } else { if (inet_ntop(AF_INET, &address.sin6.sin6_addr.s6_addr[12], namebuf, INET6_ADDRSTRLEN + 1) == NULL) { strcpy(namebuf, ":unknown:"); } memcpy(&addr.ip.v4, &address.sin6.sin6_addr.s6_addr[12], sizeof addr.ip.v4); } port.NotAnInteger = address.sin6.sin6_port; } else if (address.sa.sa_family == AF_INET) { addr.type = mDNSAddrType_IPv4; memcpy(&addr.ip.v4, &address.sin.sin_addr, sizeof addr.ip.v4); port.NotAnInteger = address.sin.sin_port; if (inet_ntop(AF_INET, &address.sin.sin_addr, namebuf, INET6_ADDRSTRLEN + 1) == NULL) { strcpy(namebuf, ":unknown:"); } } else { LogMsg("mDNSPosixDoTCPListenCallback: connection from unknown address family %d", address.sa.sa_family); close(remoteSock); goto out; } nbp = namebuf + strlen(namebuf); *nbp++ = '%'; snprintf(nbp, 6, "%u", ntohs(port.NotAnInteger)); sock = mDNSPlatformTCPAccept(socketFlags, remoteSock); if (sock == NULL) { LogMsg("mDNSPosixDoTCPListenCallback: mDNSPlatformTCPAccept returned NULL; dropping connection from %s", namebuf); close(remoteSock); goto out; } callback(sock, &addr, &port, namebuf, context); out: return sock; } mDNSexport mDNSBool mDNSPosixTCPListen(int *fd, mDNSAddr_Type addrtype, mDNSIPPort *port, mDNSAddr *addr, mDNSBool reuseAddr, int queueLength) { union { struct sockaddr_in6 sin6; struct sockaddr_in sin; struct sockaddr sa; } address; int failed; int sock; int one = 1; socklen_t sock_len; // We require an addrtype parameter because addr is allowed to be null, but they have to agree. if (addr != mDNSNULL && addr->type != addrtype) { LogMsg("mDNSPlatformTCPListen: address type conflict: %d:%d", addr->type, addrtype); return mDNSfalse; } if (port == mDNSNULL) { LogMsg("mDNSPlatformTCPListen: port must not be NULL"); return mDNSfalse; } mDNSPlatformMemZero(&address, sizeof address); if (addrtype == mDNSAddrType_None || addrtype == mDNSAddrType_IPv6) { // Set up DNS listener socket if (addr != mDNSNULL) { memcpy(&address.sin6.sin6_addr.s6_addr, &addr->ip, sizeof address.sin6.sin6_addr.s6_addr); } address.sin6.sin6_port = port->NotAnInteger; sock_len = sizeof address.sin6; address.sin6.sin6_family = AF_INET6; } else if (addrtype == mDNSAddrType_IPv4) { if (addr != mDNSNULL) { memcpy(&address.sin.sin_addr.s_addr, &addr->ip, sizeof address.sin.sin_addr.s_addr); } address.sin.sin_port = port->NotAnInteger; sock_len = sizeof address.sin; address.sin.sin_family = AF_INET; } else { LogMsg("mDNSPlatformTCPListen: invalid address type: %d", addrtype); return mDNSfalse; } #ifndef NOT_HAVE_SA_LEN address.sa.sa_len = sock_len; #endif sock = socket(address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP); if (sock < 0) { LogMsg("mDNSPlatformTCPListen: socket call failed: %s", strerror(errno)); return mDNSfalse; } *fd = sock; // The reuseAddr flag is used to indicate that we want to listen on this port even if // there are still lingering sockets. We will still fail if there is another listener. // Note that this requires SO_REUSEADDR, not SO_REUSEPORT, which does not have special // handling for lingering sockets. if (reuseAddr) { failed = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one); if (failed < 0) { LogMsg("mDNSPlatformTCPListen: SO_REUSEADDR failed %s", strerror(errno)); return mDNSfalse; } } // Bind to the port and (if provided) address failed = bind(sock, &address.sa, sock_len); if (failed < 0) { LogMsg("mDNSPlatformTCPListen: bind failed %s", strerror(errno)); return mDNSfalse; } // If there was no specified listen port, we need to know what port we got. if (port->NotAnInteger == 0) { mDNSPlatformMemZero(&address, sizeof address); failed = getsockname(sock, &address.sa, &sock_len); if (failed < 0) { LogMsg("mDNSRelay: getsockname failed: %s", strerror(errno)); return mDNSfalse; } if (address.sa.sa_family == AF_INET) { port->NotAnInteger = address.sin.sin_port; } else { port->NotAnInteger = address.sin6.sin6_port; } } failed = listen(sock, queueLength); if (failed < 0) { LogMsg("mDNSPlatformTCPListen: listen failed: %s", strerror(errno)); return mDNSfalse; } return mDNStrue; } mDNSexport long mDNSPosixReadTCP(int fd, void *buf, unsigned long buflen, mDNSBool *closed) { static int CLOSEDcount = 0; static int EAGAINcount = 0; ssize_t nread = recv(fd, buf, buflen, 0); if (nread > 0) { CLOSEDcount = 0; EAGAINcount = 0; } // On success, clear our error counters else if (nread == 0) { *closed = mDNStrue; if ((++CLOSEDcount % 20) == 0) { LogMsg("ERROR: mDNSPosixReadFromSocket - recv %d got CLOSED %d times", fd, CLOSEDcount); assert(CLOSEDcount < 1000); // Recovery Mechanism to bail mDNSResponder out of trouble: Instead of logging the same error // msg multiple times, crash mDNSResponder using assert() and restart fresh. See advantages // below: // 1.Better User Experience // 2.CrashLogs frequency can be monitored // 3.StackTrace can be used for more info } } // else nread is negative -- see what kind of error we got else if (errno == ECONNRESET) { nread = 0; *closed = mDNStrue; } else if (errno != EAGAIN) { LogMsg("ERROR: mDNSPosixReadFromSocket - recv: %d (%s)", errno, strerror(errno)); nread = -1; } else { // errno is EAGAIN (EWOULDBLOCK) -- no data available nread = 0; if ((++EAGAINcount % 1000) == 0) { LogMsg("ERROR: mDNSPosixReadFromSocket - recv %d got EAGAIN %d times", fd, EAGAINcount); sleep(1); } } return nread; } mDNSexport long mDNSPosixWriteTCP(int fd, const char *msg, unsigned long len) { ssize_t result; long nsent; result = write(fd, msg, len); if (result < 0) { if (errno == EAGAIN) { nsent = 0; } else { LogMsg("ERROR: mDNSPosixWriteTCP - send %s", strerror(errno)); nsent = -1; } } else { nsent = (long)result; } return nsent; } /* -*- Mode: C; tab-width: 4; c-file-style: "bsd"; c-basic-offset: 4; fill-column: 108; indent-tabs-mode: nil; -*- * * Copyright (c) 2004 Apple Computer, Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __PLATFORM_COMMON_H #define __PLATFORM_COMMON_H extern void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled); extern mDNSBool mDNSPosixTCPSocketSetup(int *fd, mDNSAddr_Type addrType, mDNSIPPort *port, mDNSIPPort *outTcpPort); extern TCPSocket *mDNSPosixDoTCPListenCallback(int fd, mDNSAddr_Type addressType, TCPSocketFlags socketFlags, TCPAcceptedCallback callback, void *context); extern mDNSBool mDNSPosixTCPListen(int *fd, mDNSAddr_Type addrtype, mDNSIPPort *port, mDNSAddr *addr, mDNSBool reuseAddr, int queueLength); extern long mDNSPosixReadTCP(int fd, void *buf, unsigned long buflen, mDNSBool *closed); extern long mDNSPosixWriteTCP(int fd, const char *msg, unsigned long len); #endif /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2003-2018 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of Apple Inc. ("Apple") nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /*! @header DNS Service Discovery * * @discussion This section describes the functions, callbacks, and data structures * that make up the DNS Service Discovery API. * * The DNS Service Discovery API is part of Bonjour, Apple's implementation * of zero-configuration networking (ZEROCONF). * * Bonjour allows you to register a network service, such as a * printer or file server, so that it can be found by name or browsed * for by service type and domain. Using Bonjour, applications can * discover what services are available on the network, along with * all the information -- such as name, IP address, and port -- * necessary to access a particular service. * * In effect, Bonjour combines the functions of a local DNS server and * AppleTalk. Bonjour allows applications to provide user-friendly printer * and server browsing, among other things, over standard IP networks. * This behavior is a result of combining protocols such as multicast and * DNS to add new functionality to the network (such as multicast DNS). * * Bonjour gives applications easy access to services over local IP * networks without requiring the service or the application to support * an AppleTalk or a Netbeui stack, and without requiring a DNS server * for the local network. */ /* _DNS_SD_H contains the API version number for this header file * The API version defined in this header file symbol allows for compile-time * checking, so that C code building with earlier versions of the header file * can avoid compile errors trying to use functions that aren't even defined * in those earlier versions. Similar checks may also be performed at run-time: * => weak linking -- to avoid link failures if run with an earlier * version of the library that's missing some desired symbol, or * => DNSServiceGetProperty(DaemonVersion) -- to verify whether the running daemon * ("system service" on Windows) meets some required minimum functionality level. */ #ifndef _DNS_SD_H #define _DNS_SD_H 13108001 #ifdef __cplusplus extern "C" { #endif /* Set to 1 if libdispatch is supported * Note: May also be set by project and/or Makefile */ #if defined(__APPLE__) #define _DNS_SD_LIBDISPATCH 1 #else #define _DNS_SD_LIBDISPATCH 0 #endif /* standard calling convention under Win32 is __stdcall */ /* Note: When compiling Intel EFI (Extensible Firmware Interface) under MS Visual Studio, the */ /* _WIN32 symbol is defined by the compiler even though it's NOT compiling code for Windows32 */ #if defined(_WIN32) && !defined(EFI32) && !defined(EFI64) #define DNSSD_API __stdcall #else #define DNSSD_API #endif #if (defined(__GNUC__) && (__GNUC__ >= 4)) #define DNSSD_EXPORT __attribute__((visibility("default"))) #else #define DNSSD_EXPORT #endif #if defined(_WIN32) #include typedef SOCKET dnssd_sock_t; #else typedef int dnssd_sock_t; #endif /* stdint.h does not exist on FreeBSD 4.x; its types are defined in sys/types.h instead */ #if defined(__FreeBSD__) && (__FreeBSD__ < 5) #include /* Likewise, on Sun, standard integer types are in sys/types.h */ #elif defined(__sun__) #include /* EFI does not have stdint.h, or anything else equivalent */ #elif defined(EFI32) || defined(EFI64) || defined(EFIX64) #include "Tiano.h" #if !defined(_STDINT_H_) typedef UINT8 uint8_t; typedef INT8 int8_t; typedef UINT16 uint16_t; typedef INT16 int16_t; typedef UINT32 uint32_t; typedef INT32 int32_t; #endif /* Windows has its own differences */ #elif defined(_WIN32) #include #define _UNUSED #ifndef _MSL_STDINT_H typedef UINT8 uint8_t; typedef INT8 int8_t; typedef UINT16 uint16_t; typedef INT16 int16_t; typedef UINT32 uint32_t; typedef INT32 int32_t; #endif /* All other Posix platforms use stdint.h */ #else #include #endif #if _DNS_SD_LIBDISPATCH #include #endif /* DNSServiceRef, DNSRecordRef * * Opaque internal data types. * Note: client is responsible for serializing access to these structures if * they are shared between concurrent threads. */ typedef struct _DNSServiceRef_t *DNSServiceRef; typedef struct _DNSRecordRef_t *DNSRecordRef; struct sockaddr; /*! @enum General flags * Most DNS-SD API functions and callbacks include a DNSServiceFlags parameter. * As a general rule, any given bit in the 32-bit flags field has a specific fixed meaning, * regardless of the function or callback being used. For any given function or callback, * typically only a subset of the possible flags are meaningful, and all others should be zero. * The discussion section for each API call describes which flags are valid for that call * and callback. In some cases, for a particular call, it may be that no flags are currently * defined, in which case the DNSServiceFlags parameter exists purely to allow future expansion. * In all cases, developers should expect that in future releases, it is possible that new flag * values will be defined, and write code with this in mind. For example, code that tests * if (flags == kDNSServiceFlagsAdd) ... * will fail if, in a future release, another bit in the 32-bit flags field is also set. * The reliable way to test whether a particular bit is set is not with an equality test, * but with a bitwise mask: * if (flags & kDNSServiceFlagsAdd) ... * With the exception of kDNSServiceFlagsValidate, each flag can be valid(be set) * EITHER only as an input to one of the DNSService*() APIs OR only as an output * (provide status) through any of the callbacks used. For example, kDNSServiceFlagsAdd * can be set only as an output in the callback, whereas the kDNSServiceFlagsIncludeP2P * can be set only as an input to the DNSService*() APIs. See comments on kDNSServiceFlagsValidate * defined in enum below. */ enum { kDNSServiceFlagsMoreComing = 0x1, /* MoreComing indicates to a callback that at least one more result is * queued and will be delivered following immediately after this one. * When the MoreComing flag is set, applications should not immediately * update their UI, because this can result in a great deal of ugly flickering * on the screen, and can waste a great deal of CPU time repeatedly updating * the screen with content that is then immediately erased, over and over. * Applications should wait until MoreComing is not set, and then * update their UI when no more changes are imminent. * When MoreComing is not set, that doesn't mean there will be no more * answers EVER, just that there are no more answers immediately * available right now at this instant. If more answers become available * in the future they will be delivered as usual. */ kDNSServiceFlagsAutoTrigger = 0x1, /* Valid for browses using kDNSServiceInterfaceIndexAny. * Will auto trigger the browse over AWDL as well once the service is discovered * over BLE. * This flag is an input value to DNSServiceBrowse(), which is why we can * use the same value as kDNSServiceFlagsMoreComing, which is an output flag * for various client callbacks. */ kDNSServiceFlagsAdd = 0x2, kDNSServiceFlagsDefault = 0x4, /* Flags for domain enumeration and browse/query reply callbacks. * "Default" applies only to enumeration and is only valid in * conjunction with "Add". An enumeration callback with the "Add" * flag NOT set indicates a "Remove", i.e. the domain is no longer * valid. */ kDNSServiceFlagsNoAutoRename = 0x8, /* Flag for specifying renaming behavior on name conflict when registering * non-shared records. By default, name conflicts are automatically handled * by renaming the service. NoAutoRename overrides this behavior - with this * flag set, name conflicts will result in a callback. The NoAutorename flag * is only valid if a name is explicitly specified when registering a service * (i.e. the default name is not used.) */ kDNSServiceFlagsShared = 0x10, kDNSServiceFlagsUnique = 0x20, /* Flag for registering individual records on a connected * DNSServiceRef. Shared indicates that there may be multiple records * with this name on the network (e.g. PTR records). Unique indicates that the * record's name is to be unique on the network (e.g. SRV records). */ kDNSServiceFlagsBrowseDomains = 0x40, kDNSServiceFlagsRegistrationDomains = 0x80, /* Flags for specifying domain enumeration type in DNSServiceEnumerateDomains. * BrowseDomains enumerates domains recommended for browsing, RegistrationDomains * enumerates domains recommended for registration. */ kDNSServiceFlagsLongLivedQuery = 0x100, /* Flag for creating a long-lived unicast query for the DNSServiceQueryRecord call. */ kDNSServiceFlagsAllowRemoteQuery = 0x200, /* Flag for creating a record for which we will answer remote queries * (queries from hosts more than one hop away; hosts not directly connected to the local link). */ kDNSServiceFlagsForceMulticast = 0x400, /* Flag for signifying that a query or registration should be performed exclusively via multicast * DNS, even for a name in a domain (e.g. foo.apple.com.) that would normally imply unicast DNS. */ kDNSServiceFlagsForce = 0x800, // This flag is deprecated. kDNSServiceFlagsKnownUnique = 0x800, /* * Client guarantees that record names are unique, so we can skip sending out initial * probe messages. Standard name conflict resolution is still done if a conflict is discovered. */ kDNSServiceFlagsReturnIntermediates = 0x1000, /* Flag for returning intermediate results. * For example, if a query results in an authoritative NXDomain (name does not exist) * then that result is returned to the client. However the query is not implicitly * cancelled -- it remains active and if the answer subsequently changes * (e.g. because a VPN tunnel is subsequently established) then that positive * result will still be returned to the client. * Similarly, if a query results in a CNAME record, then in addition to following * the CNAME referral, the intermediate CNAME result is also returned to the client. * When this flag is not set, NXDomain errors are not returned, and CNAME records * are followed silently without informing the client of the intermediate steps. * (In earlier builds this flag was briefly calledkDNSServiceFlagsReturnCNAME) */ kDNSServiceFlagsShareConnection = 0x4000, /* For efficiency, clients that perform many concurrent operations may want to use a * single Unix Domain Socket connection with the background daemon, instead of having a * separate connection for each independent operation. To use this mode, clients first * call DNSServiceCreateConnection(&SharedRef) to initialize the main DNSServiceRef. * For each subsequent operation that is to share that same connection, the client copies * the SharedRef, and then passes the address of that copy, setting the ShareConnection flag * to tell the library that this DNSServiceRef is not a typical uninitialized DNSServiceRef; * it's a copy of an existing DNSServiceRef whose connection information should be reused. * * For example: * * DNSServiceErrorType error; * DNSServiceRef SharedRef; * error = DNSServiceCreateConnection(&SharedRef); * if (error) ... * DNSServiceRef BrowseRef = SharedRef; // Important: COPY the primary DNSServiceRef first... * error = DNSServiceBrowse(&BrowseRef, kDNSServiceFlagsShareConnection, ...); // then use the copy * if (error) ... * ... * DNSServiceRefDeallocate(BrowseRef); // Terminate the browse operation * DNSServiceRefDeallocate(SharedRef); // Terminate the shared connection * * Notes: * * 1. Collective kDNSServiceFlagsMoreComing flag * When callbacks are invoked using a shared DNSServiceRef, the * kDNSServiceFlagsMoreComing flag applies collectively to *all* active * operations sharing the same parent DNSServiceRef. If the MoreComing flag is * set it means that there are more results queued on this parent DNSServiceRef, * but not necessarily more results for this particular callback function. * The implication of this for client programmers is that when a callback * is invoked with the MoreComing flag set, the code should update its * internal data structures with the new result, and set a variable indicating * that its UI needs to be updated. Then, later when a callback is eventually * invoked with the MoreComing flag not set, the code should update *all* * stale UI elements related to that shared parent DNSServiceRef that need * updating, not just the UI elements related to the particular callback * that happened to be the last one to be invoked. * * 2. Canceling operations and kDNSServiceFlagsMoreComing * Whenever you cancel any operation for which you had deferred UI updates * waiting because of a kDNSServiceFlagsMoreComing flag, you should perform * those deferred UI updates. This is because, after cancelling the operation, * you can no longer wait for a callback *without* MoreComing set, to tell * you do perform your deferred UI updates (the operation has been canceled, * so there will be no more callbacks). An implication of the collective * kDNSServiceFlagsMoreComing flag for shared connections is that this * guideline applies more broadly -- any time you cancel an operation on * a shared connection, you should perform all deferred UI updates for all * operations sharing that connection. This is because the MoreComing flag * might have been referring to events coming for the operation you canceled, * which will now not be coming because the operation has been canceled. * * 3. Only share DNSServiceRef's created with DNSServiceCreateConnection * Calling DNSServiceCreateConnection(&ref) creates a special shareable DNSServiceRef. * DNSServiceRef's created by other calls like DNSServiceBrowse() or DNSServiceResolve() * cannot be shared by copying them and using kDNSServiceFlagsShareConnection. * * 4. Don't Double-Deallocate * Calling DNSServiceRefDeallocate(OpRef) for a particular operation's DNSServiceRef terminates * just that operation. Calling DNSServiceRefDeallocate(SharedRef) for the main shared DNSServiceRef * (the parent DNSServiceRef, originally created by DNSServiceCreateConnection(&SharedRef)) * automatically terminates the shared connection *and* all operations that were still using it. * After doing this, DO NOT then attempt to deallocate any remaining subordinate DNSServiceRef's. * The memory used by those subordinate DNSServiceRef's has already been freed, so any attempt * to do a DNSServiceRefDeallocate (or any other operation) on them will result in accesses * to freed memory, leading to crashes or other equally undesirable results. * You can deallocate individual operations first and then deallocate the parent DNSServiceRef last, * but if you deallocate the parent DNSServiceRef first, then all of the subordinate DNSServiceRef's * are implicitly deallocated, and explicitly deallocating them a second time will lead to crashes. * * 5. Thread Safety * The dns_sd.h API does not presuppose any particular threading model, and consequently * does no locking internally (which would require linking with a specific threading library). * If the client concurrently, from multiple threads (or contexts), calls API routines using * the same DNSServiceRef, it is the client's responsibility to provide mutual exclusion for * that DNSServiceRef. * * For example, use of DNSServiceRefDeallocate requires caution. A common mistake is as follows: * Thread B calls DNSServiceRefDeallocate to deallocate sdRef while Thread A is processing events * using sdRef. Doing this will lead to intermittent crashes on thread A if the sdRef is used after * it was deallocated. * * A telltale sign of this crash type is to see DNSServiceProcessResult on the stack preceding the * actual crash location. * * To state this more explicitly, mDNSResponder does not queue DNSServiceRefDeallocate so * that it occurs discretely before or after an event is handled. */ kDNSServiceFlagsSuppressUnusable = 0x8000, /* * This flag is meaningful only in DNSServiceQueryRecord which suppresses unusable queries on the * wire. If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) * but this host has no routable IPv6 address, then the call will not try to look up IPv6 addresses * for "hostname", since any addresses it found would be unlikely to be of any use anyway. Similarly, * if this host has no routable IPv4 address, the call will not try to look up IPv4 addresses for * "hostname". */ kDNSServiceFlagsTimeout = 0x10000, /* * When kDNServiceFlagsTimeout is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, the query is * stopped after a certain number of seconds have elapsed. The time at which the query will be stopped * is determined by the system and cannot be configured by the user. The query will be stopped irrespective * of whether a response was given earlier or not. When the query is stopped, the callback will be called * with an error code of kDNSServiceErr_Timeout and a NULL sockaddr will be returned for DNSServiceGetAddrInfo * and zero length rdata will be returned for DNSServiceQueryRecord. */ kDNSServiceFlagsIncludeP2P = 0x20000, /* * Include P2P interfaces when kDNSServiceInterfaceIndexAny is specified. * By default, specifying kDNSServiceInterfaceIndexAny does not include P2P interfaces. */ kDNSServiceFlagsWakeOnResolve = 0x40000, /* * This flag is meaningful only in DNSServiceResolve. When set, it tries to send a magic packet * to wake up the client. */ kDNSServiceFlagsBackgroundTrafficClass = 0x80000, /* * This flag is meaningful for Unicast DNS queries. When set, it uses the background traffic * class for packets that service the request. */ kDNSServiceFlagsIncludeAWDL = 0x100000, /* * Include AWDL interface when kDNSServiceInterfaceIndexAny is specified. */ kDNSServiceFlagsEnableDNSSEC = 0x200000, /* * Perform DNSSEC validation on the client request when kDNSServiceFlagsEnableDNSSEC is specified * Since the client API has not been finalized, we will use it as a temporary flag to turn on the DNSSEC validation. */ kDNSServiceFlagsValidate = 0x200000, /* * This flag is meaningful in DNSServiceGetAddrInfo and DNSServiceQueryRecord. This is the ONLY flag to be valid * as an input to the APIs and also an output through the callbacks in the APIs. * * When this flag is passed to DNSServiceQueryRecord and DNSServiceGetAddrInfo to resolve unicast names, * the response will be validated using DNSSEC. The validation results are delivered using the flags field in * the callback and kDNSServiceFlagsValidate is marked in the flags to indicate that DNSSEC status is also available. * When the callback is called to deliver the query results, the validation results may or may not be available. * If it is not delivered along with the results, the validation status is delivered when the validation completes. * * When the validation results are delivered in the callback, it is indicated by marking the flags with * kDNSServiceFlagsValidate and kDNSServiceFlagsAdd along with the DNSSEC status flags (described below) and a NULL * sockaddr will be returned for DNSServiceGetAddrInfo and zero length rdata will be returned for DNSServiceQueryRecord. * DNSSEC validation results are for the whole RRSet and not just individual records delivered in the callback. When * kDNSServiceFlagsAdd is not set in the flags, applications should implicitly assume that the DNSSEC status of the * RRSet that has been delivered up until that point is not valid anymore, till another callback is called with * kDNSServiceFlagsAdd and kDNSServiceFlagsValidate. * * The following four flags indicate the status of the DNSSEC validation and marked in the flags field of the callback. * When any of the four flags is set, kDNSServiceFlagsValidate will also be set. To check the validation status, the * other applicable output flags should be masked. */ kDNSServiceFlagsSecure = 0x200010, /* * The response has been validated by verifying all the signatures in the response and was able to * build a successful authentication chain starting from a known trust anchor. */ kDNSServiceFlagsInsecure = 0x200020, /* * A chain of trust cannot be built starting from a known trust anchor to the response. */ kDNSServiceFlagsBogus = 0x200040, /* * If the response cannot be verified to be secure due to expired signatures, missing signatures etc., * then the results are considered to be bogus. */ kDNSServiceFlagsIndeterminate = 0x200080, /* * There is no valid trust anchor that can be used to determine whether a response is secure or not. */ kDNSServiceFlagsUnicastResponse = 0x400000, /* * Request unicast response to query. */ kDNSServiceFlagsValidateOptional = 0x800000, /* * This flag is identical to kDNSServiceFlagsValidate except for the case where the response * cannot be validated. If this flag is set in DNSServiceQueryRecord or DNSServiceGetAddrInfo, * the DNSSEC records will be requested for validation. If they cannot be received for some reason * during the validation (e.g., zone is not signed, zone is signed but cannot be traced back to * root, recursive server does not understand DNSSEC etc.), then this will fallback to the default * behavior where the validation will not be performed and no DNSSEC results will be provided. * * If the zone is signed and there is a valid path to a known trust anchor configured in the system * and the application requires DNSSEC validation irrespective of the DNSSEC awareness in the current * network, then this option MUST not be used. This is only intended to be used during the transition * period where the different nodes participating in the DNS resolution may not understand DNSSEC or * managed properly (e.g. missing DS record) but still want to be able to resolve DNS successfully. */ kDNSServiceFlagsWakeOnlyService = 0x1000000, /* * This flag is meaningful only in DNSServiceRegister. When set, the service will not be registered * with sleep proxy server during sleep. */ kDNSServiceFlagsThresholdOne = 0x2000000, kDNSServiceFlagsThresholdFinder = 0x4000000, kDNSServiceFlagsThresholdReached = kDNSServiceFlagsThresholdOne, /* * kDNSServiceFlagsThresholdOne is meaningful only in DNSServiceBrowse. When set, * the system will stop issuing browse queries on the network once the number * of answers returned is one or more. It will issue queries on the network * again if the number of answers drops to zero. * This flag is for Apple internal use only. Third party developers * should not rely on this behavior being supported in any given software release. * * kDNSServiceFlagsThresholdFinder is meaningful only in DNSServiceBrowse. When set, * the system will stop issuing browse queries on the network once the number * of answers has reached the threshold set for Finder. * It will issue queries on the network again if the number of answers drops below * this threshold. * This flag is for Apple internal use only. Third party developers * should not rely on this behavior being supported in any given software release. * * When kDNSServiceFlagsThresholdReached is set in the client callback add or remove event, * it indicates that the browse answer threshold has been reached and no * browse requests will be generated on the network until the number of answers falls * below the threshold value. Add and remove events can still occur based * on incoming Bonjour traffic observed by the system. * The set of services return to the client is not guaranteed to represent the * entire set of services present on the network once the threshold has been reached. * * Note, while kDNSServiceFlagsThresholdReached and kDNSServiceFlagsThresholdOne * have the same value, there isn't a conflict because kDNSServiceFlagsThresholdReached * is only set in the callbacks and kDNSServiceFlagsThresholdOne is only set on * input to a DNSServiceBrowse call. */ kDNSServiceFlagsPrivateOne = 0x2000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateTwo = 0x8000000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateThree = 0x10000000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateFour = 0x20000000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateFive = 0x40000000, /* * This flag is private and should not be used. */ kDNSServiceFlagAnsweredFromCache = 0x40000000, /* * When kDNSServiceFlagAnsweredFromCache is passed back in the flags parameter of DNSServiceQueryRecordReply or DNSServiceGetAddrInfoReply, * an answer will have this flag set if it was answered from the cache. */ kDNSServiceFlagsAllowExpiredAnswers = 0x80000000, /* * When kDNSServiceFlagsAllowExpiredAnswers is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, * if there are matching expired records still in the cache, then they are immediately returned to the * client, and in parallel a network query for that name is issued. All returned records from the query will * remain in the cache after expiration. */ kDNSServiceFlagsExpiredAnswer = 0x80000000 /* * When kDNSServiceFlagsAllowExpiredAnswers is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, * an expired answer will have this flag set. */ }; /* Possible protocol values */ enum { /* for DNSServiceGetAddrInfo() */ kDNSServiceProtocol_IPv4 = 0x01, kDNSServiceProtocol_IPv6 = 0x02, /* 0x04 and 0x08 reserved for future internetwork protocols */ /* for DNSServiceNATPortMappingCreate() */ kDNSServiceProtocol_UDP = 0x10, kDNSServiceProtocol_TCP = 0x20 /* 0x40 and 0x80 reserved for future transport protocols, e.g. SCTP [RFC 2960] * or DCCP [RFC 4340]. If future NAT gateways are created that support port * mappings for these protocols, new constants will be defined here. */ }; /* * The values for DNS Classes and Types are listed in RFC 1035, and are available * on every OS in its DNS header file. Unfortunately every OS does not have the * same header file containing DNS Class and Type constants, and the names of * the constants are not consistent. For example, BIND 8 uses "T_A", * BIND 9 uses "ns_t_a", Windows uses "DNS_TYPE_A", etc. * For this reason, these constants are also listed here, so that code using * the DNS-SD programming APIs can use these constants, so that the same code * can compile on all our supported platforms. */ enum { kDNSServiceClass_IN = 1 /* Internet */ }; enum { kDNSServiceType_A = 1, /* Host address. */ kDNSServiceType_NS = 2, /* Authoritative server. */ kDNSServiceType_MD = 3, /* Mail destination. */ kDNSServiceType_MF = 4, /* Mail forwarder. */ kDNSServiceType_CNAME = 5, /* Canonical name. */ kDNSServiceType_SOA = 6, /* Start of authority zone. */ kDNSServiceType_MB = 7, /* Mailbox domain name. */ kDNSServiceType_MG = 8, /* Mail group member. */ kDNSServiceType_MR = 9, /* Mail rename name. */ kDNSServiceType_NULL = 10, /* Null resource record. */ kDNSServiceType_WKS = 11, /* Well known service. */ kDNSServiceType_PTR = 12, /* Domain name pointer. */ kDNSServiceType_HINFO = 13, /* Host information. */ kDNSServiceType_MINFO = 14, /* Mailbox information. */ kDNSServiceType_MX = 15, /* Mail routing information. */ kDNSServiceType_TXT = 16, /* One or more text strings (NOT "zero or more..."). */ kDNSServiceType_RP = 17, /* Responsible person. */ kDNSServiceType_AFSDB = 18, /* AFS cell database. */ kDNSServiceType_X25 = 19, /* X_25 calling address. */ kDNSServiceType_ISDN = 20, /* ISDN calling address. */ kDNSServiceType_RT = 21, /* Router. */ kDNSServiceType_NSAP = 22, /* NSAP address. */ kDNSServiceType_NSAP_PTR = 23, /* Reverse NSAP lookup (deprecated). */ kDNSServiceType_SIG = 24, /* Security signature. */ kDNSServiceType_KEY = 25, /* Security key. */ kDNSServiceType_PX = 26, /* X.400 mail mapping. */ kDNSServiceType_GPOS = 27, /* Geographical position (withdrawn). */ kDNSServiceType_AAAA = 28, /* IPv6 Address. */ kDNSServiceType_LOC = 29, /* Location Information. */ kDNSServiceType_NXT = 30, /* Next domain (security). */ kDNSServiceType_EID = 31, /* Endpoint identifier. */ kDNSServiceType_NIMLOC = 32, /* Nimrod Locator. */ kDNSServiceType_SRV = 33, /* Server Selection. */ kDNSServiceType_ATMA = 34, /* ATM Address */ kDNSServiceType_NAPTR = 35, /* Naming Authority PoinTeR */ kDNSServiceType_KX = 36, /* Key Exchange */ kDNSServiceType_CERT = 37, /* Certification record */ kDNSServiceType_A6 = 38, /* IPv6 Address (deprecated) */ kDNSServiceType_DNAME = 39, /* Non-terminal DNAME (for IPv6) */ kDNSServiceType_SINK = 40, /* Kitchen sink (experimental) */ kDNSServiceType_OPT = 41, /* EDNS0 option (meta-RR) */ kDNSServiceType_APL = 42, /* Address Prefix List */ kDNSServiceType_DS = 43, /* Delegation Signer */ kDNSServiceType_SSHFP = 44, /* SSH Key Fingerprint */ kDNSServiceType_IPSECKEY = 45, /* IPSECKEY */ kDNSServiceType_RRSIG = 46, /* RRSIG */ kDNSServiceType_NSEC = 47, /* Denial of Existence */ kDNSServiceType_DNSKEY = 48, /* DNSKEY */ kDNSServiceType_DHCID = 49, /* DHCP Client Identifier */ kDNSServiceType_NSEC3 = 50, /* Hashed Authenticated Denial of Existence */ kDNSServiceType_NSEC3PARAM = 51, /* Hashed Authenticated Denial of Existence */ kDNSServiceType_HIP = 55, /* Host Identity Protocol */ kDNSServiceType_SVCB = 64, /* Service Binding. */ kDNSServiceType_HTTPS = 65, /* HTTPS Service Binding. */ kDNSServiceType_SPF = 99, /* Sender Policy Framework for E-Mail */ kDNSServiceType_UINFO = 100, /* IANA-Reserved */ kDNSServiceType_UID = 101, /* IANA-Reserved */ kDNSServiceType_GID = 102, /* IANA-Reserved */ kDNSServiceType_UNSPEC = 103, /* IANA-Reserved */ kDNSServiceType_TKEY = 249, /* Transaction key */ kDNSServiceType_TSIG = 250, /* Transaction signature. */ kDNSServiceType_IXFR = 251, /* Incremental zone transfer. */ kDNSServiceType_AXFR = 252, /* Transfer zone of authority. */ kDNSServiceType_MAILB = 253, /* Transfer mailbox records. */ kDNSServiceType_MAILA = 254, /* Transfer mail agent records. */ kDNSServiceType_ANY = 255 /* Wildcard match. */ }; /* possible error code values */ enum { kDNSServiceErr_NoError = 0, kDNSServiceErr_Unknown = -65537, /* 0xFFFE FFFF */ kDNSServiceErr_NoSuchName = -65538, kDNSServiceErr_NoMemory = -65539, kDNSServiceErr_BadParam = -65540, kDNSServiceErr_BadReference = -65541, kDNSServiceErr_BadState = -65542, kDNSServiceErr_BadFlags = -65543, kDNSServiceErr_Unsupported = -65544, kDNSServiceErr_NotInitialized = -65545, kDNSServiceErr_AlreadyRegistered = -65547, kDNSServiceErr_NameConflict = -65548, kDNSServiceErr_Invalid = -65549, kDNSServiceErr_Firewall = -65550, kDNSServiceErr_Incompatible = -65551, /* client library incompatible with daemon */ kDNSServiceErr_BadInterfaceIndex = -65552, kDNSServiceErr_Refused = -65553, kDNSServiceErr_NoSuchRecord = -65554, kDNSServiceErr_NoAuth = -65555, kDNSServiceErr_NoSuchKey = -65556, kDNSServiceErr_NATTraversal = -65557, kDNSServiceErr_DoubleNAT = -65558, kDNSServiceErr_BadTime = -65559, /* Codes up to here existed in Tiger */ kDNSServiceErr_BadSig = -65560, kDNSServiceErr_BadKey = -65561, kDNSServiceErr_Transient = -65562, kDNSServiceErr_ServiceNotRunning = -65563, /* Background daemon not running */ kDNSServiceErr_NATPortMappingUnsupported = -65564, /* NAT doesn't support PCP, NAT-PMP or UPnP */ kDNSServiceErr_NATPortMappingDisabled = -65565, /* NAT supports PCP, NAT-PMP or UPnP, but it's disabled by the administrator */ kDNSServiceErr_NoRouter = -65566, /* No router currently configured (probably no network connectivity) */ kDNSServiceErr_PollingMode = -65567, kDNSServiceErr_Timeout = -65568, kDNSServiceErr_DefunctConnection = -65569, /* Connection to daemon returned a SO_ISDEFUNCT error result */ kDNSServiceErr_PolicyDenied = -65570 /* mDNS Error codes are in the range * FFFE FF00 (-65792) to FFFE FFFF (-65537) */ }; /* Maximum length, in bytes, of a service name represented as a */ /* literal C-String, including the terminating NULL at the end. */ #define kDNSServiceMaxServiceName 64 /* Maximum length, in bytes, of a domain name represented as an *escaped* C-String */ /* including the final trailing dot, and the C-String terminating NULL at the end. */ #define kDNSServiceMaxDomainName 1009 /* * Notes on DNS Name Escaping * -- or -- * "Why is kDNSServiceMaxDomainName 1009, when the maximum legal domain name is 256 bytes?" * * All strings used in the DNS-SD APIs are UTF-8 strings. * Apart from the exceptions noted below, the APIs expect the strings to be properly escaped, using the * conventional DNS escaping rules, as used by the traditional DNS res_query() API, as described below: * * Generally all UTF-8 characters (which includes all US ASCII characters) represent themselves, * with three exceptions: * the dot ('.') character, which is the DNS label separator, * the backslash ('\') character, which is the DNS escape character, and * the ASCII NUL (0) byte value, which is the C-string terminator character. * The escape character ('\') is interpreted as described below: * * '\ddd', where ddd is a three-digit decimal value from 000 to 255, * represents a single literal byte with that value. Any byte value may be * represented in '\ddd' format, even characters that don't strictly need to be escaped. * For example, the ASCII code for 'w' is 119, and therefore '\119' is equivalent to 'w'. * Thus the command "ping '\119\119\119.apple.com'" is the equivalent to the command "ping 'www.apple.com'". * Nonprinting ASCII characters in the range 0-31 are often represented this way. * In particular, the ASCII NUL character (0) cannot appear in a C-string because C uses it as the * string terminator character, so ASCII NUL in a domain name has to be represented in a C-string as '\000'. * Other characters like space (ASCII code 32) are sometimes represented as '\032' * in contexts where having an actual space character in a C-string would be inconvenient. * * Otherwise, for all cases where a '\' is followed by anything other than a three-digit decimal value * from 000 to 255, the character sequence '\x' represents a single literal occurrence of character 'x'. * This is legal for any character, so, for example, '\w' is equivalent to 'w'. * Thus the command "ping '\w\w\w.apple.com'" is the equivalent to the command "ping 'www.apple.com'". * However, this encoding is most useful when representing the characters '.' and '\', * which otherwise would have special meaning in DNS name strings. * This means that the following encodings are particularly common: * '\\' represents a single literal '\' in the name * '\.' represents a single literal '.' in the name * * A lone escape character ('\') appearing at the end of a string is not allowed, since it is * followed by neither a three-digit decimal value from 000 to 255 nor a single character. * If a lone escape character ('\') does appear as the last character of a string, it is silently ignored. * * The worse-case length for an escaped domain name is calculated as follows: * The longest legal domain name is 256 bytes in wire format (see RFC 6762, Appendix C, DNS Name Length). * For our calculation of the longest *escaped* domain name, we use * the longest legal domain name, with the most characters escaped. * * We consider a domain name of the form: "label63.label63.label63.label62." * where "label63" is a 63-byte label and "label62" is a 62-byte label. * Counting four label-length bytes, 251 bytes of label data, and the terminating zero, * this makes a total of 256 bytes in wire format, the longest legal domain name. * * If each one of the 251 bytes of label data is represented using '\ddd', * then it takes 251 * 4 = 1004 bytes to represent these in a C-string. * Adding four '.' characters as shown above, plus the C-string terminating * zero at the end, results in a maximum storage requirement of 1009 bytes. * * The exceptions, that do not use escaping, are the routines where the full * DNS name of a resource is broken, for convenience, into servicename/regtype/domain. * In these routines, the "servicename" is NOT escaped. It does not need to be, since * it is, by definition, just a single literal string. Any characters in that string * represent exactly what they are. The "regtype" portion is, technically speaking, * escaped, but since legal regtypes are only allowed to contain US ASCII letters, * digits, and hyphens, there is nothing to escape, so the issue is moot. * The "domain" portion is also escaped, though most domains in use on the public * Internet today, like regtypes, don't contain any characters that need to be escaped. * As DNS-SD becomes more popular, rich-text domains for service discovery will * become common, so software should be written to cope with domains with escaping. * * The servicename may be up to 63 bytes of UTF-8 text (not counting the C-String * terminating NULL at the end). The regtype is of the form _service._tcp or * _service._udp, where the "service" part is 1-15 characters, which may be * letters, digits, or hyphens. The domain part of the three-part name may be * any legal domain, providing that the resulting servicename+regtype+domain * name does not exceed 256 bytes. * * For most software, these issues are transparent. When browsing, the discovered * servicenames should simply be displayed as-is. When resolving, the discovered * servicename/regtype/domain are simply passed unchanged to DNSServiceResolve(). * When a DNSServiceResolve() succeeds, the returned fullname is already in * the correct format to pass to standard system DNS APIs such as res_query(). * For converting from servicename/regtype/domain to a single properly-escaped * full DNS name, the helper function DNSServiceConstructFullName() is provided. * * The following (highly contrived) example illustrates the escaping process. * Suppose you have a service called "Dr. Smith\Dr. Johnson", of type "_ftp._tcp" * in subdomain "4th. Floor" of subdomain "Building 2" of domain "apple.com." * The full (escaped) DNS name of this service's SRV record would be: * Dr\.\032Smith\\Dr\.\032Johnson._ftp._tcp.4th\.\032Floor.Building\0322.apple.com. */ /* * Constants for specifying an interface index * * Specific interface indexes are identified via a 32-bit unsigned integer returned * by the if_nametoindex() family of calls. * * If the client passes 0 for interface index, that means "do the right thing", * which (at present) means, "if the name is in an mDNS local multicast domain * (e.g. 'local.', '254.169.in-addr.arpa.', '{8,9,A,B}.E.F.ip6.arpa.') then multicast * on all applicable interfaces, otherwise send via unicast to the appropriate * DNS server." Normally, most clients will use 0 for interface index to * automatically get the default sensible behaviour. * * If the client passes a positive interface index, then that indicates to do the * operation only on that one specified interface. * * If the client passes kDNSServiceInterfaceIndexLocalOnly when registering * a service, then that service will be found *only* by other local clients * on the same machine that are browsing using kDNSServiceInterfaceIndexLocalOnly * or kDNSServiceInterfaceIndexAny. * If a client has a 'private' service, accessible only to other processes * running on the same machine, this allows the client to advertise that service * in a way such that it does not inadvertently appear in service lists on * all the other machines on the network. * * If the client passes kDNSServiceInterfaceIndexLocalOnly when querying or * browsing, then the LocalOnly authoritative records and /etc/hosts caches * are searched and will find *all* records registered or configured on that * same local machine. * * If interested in getting negative answers to local questions while querying * or browsing, then set both the kDNSServiceInterfaceIndexLocalOnly and the * kDNSServiceFlagsReturnIntermediates flags. If no local answers exist at this * moment in time, then the reply will return an immediate negative answer. If * local records are subsequently created that answer the question, then those * answers will be delivered, for as long as the question is still active. * * If the kDNSServiceFlagsTimeout and kDNSServiceInterfaceIndexLocalOnly flags * are set simultaneously when either DNSServiceQueryRecord or DNSServiceGetAddrInfo * is called then both flags take effect. However, if DNSServiceQueryRecord is called * with both the kDNSServiceFlagsSuppressUnusable and kDNSServiceInterfaceIndexLocalOnly * flags set, then the kDNSServiceFlagsSuppressUnusable flag is ignored. * * Clients explicitly wishing to discover *only* LocalOnly services during a * browse may do this, without flags, by inspecting the interfaceIndex of each * service reported to a DNSServiceBrowseReply() callback function, and * discarding those answers where the interface index is not set to * kDNSServiceInterfaceIndexLocalOnly. * * kDNSServiceInterfaceIndexP2P is meaningful only in Browse, QueryRecord, Register, * and Resolve operations. It should not be used in other DNSService APIs. * * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceBrowse or * DNSServiceQueryRecord, it restricts the operation to P2P. * * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceRegister, it is * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P * set. * * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceResolve, it is * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P * set, because resolving a P2P service may create and/or enable an interface whose * index is not known a priori. The resolve callback will indicate the index of the * interface via which the service can be accessed. * * If applications pass kDNSServiceInterfaceIndexAny to DNSServiceBrowse * or DNSServiceQueryRecord, they must set the kDNSServiceFlagsIncludeP2P flag * to include P2P. In this case, if a service instance or the record being queried * is found over P2P, the resulting ADD event will indicate kDNSServiceInterfaceIndexP2P * as the interface index. */ #define kDNSServiceInterfaceIndexAny 0 #define kDNSServiceInterfaceIndexLocalOnly ((uint32_t)-1) #define kDNSServiceInterfaceIndexUnicast ((uint32_t)-2) #define kDNSServiceInterfaceIndexP2P ((uint32_t)-3) #define kDNSServiceInterfaceIndexBLE ((uint32_t)-4) typedef uint32_t DNSServiceFlags; typedef uint32_t DNSServiceProtocol; typedef int32_t DNSServiceErrorType; /********************************************************************************************* * * Version checking * *********************************************************************************************/ /* DNSServiceGetProperty() Parameters: * * property: The requested property. * Currently the only property defined is kDNSServiceProperty_DaemonVersion. * * result: Place to store result. * For retrieving DaemonVersion, this should be the address of a uint32_t. * * size: Pointer to uint32_t containing size of the result location. * For retrieving DaemonVersion, this should be sizeof(uint32_t). * On return the uint32_t is updated to the size of the data returned. * For DaemonVersion, the returned size is always sizeof(uint32_t), but * future properties could be defined which return variable-sized results. * * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning * if the daemon (or "system service" on Windows) is not running. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceGetProperty ( const char *property, /* Requested property (i.e. kDNSServiceProperty_DaemonVersion) */ void *result, /* Pointer to place to store result */ uint32_t *size /* size of result location */ ); /* * When requesting kDNSServiceProperty_DaemonVersion, the result pointer must point * to a 32-bit unsigned integer, and the size parameter must be set to sizeof(uint32_t). * * On return, the 32-bit unsigned integer contains the API version number * * For example, Mac OS X 10.4.9 has API version 1080400. * This allows applications to do simple greater-than and less-than comparisons: * e.g. an application that requires at least API version 1080400 can check: * if (version >= 1080400) ... * * Example usage: * uint32_t version; * uint32_t size = sizeof(version); * DNSServiceErrorType err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &version, &size); * if (!err) printf("DNS_SD API version is %d.%d\n", version / 10000, version / 100 % 100); */ #define kDNSServiceProperty_DaemonVersion "DaemonVersion" /********************************************************************************************* * * Unix Domain Socket access, DNSServiceRef deallocation, and data processing functions * *********************************************************************************************/ /* DNSServiceRefSockFD() * * Access underlying Unix domain socket for an initialized DNSServiceRef. * The DNS Service Discovery implementation uses this socket to communicate between the client and * the daemon. The application MUST NOT directly read from or write to this socket. * Access to the socket is provided so that it can be used as a kqueue event source, a CFRunLoop * event source, in a select() loop, etc. When the underlying event management subsystem (kqueue/ * select/CFRunLoop etc.) indicates to the client that data is available for reading on the * socket, the client should call DNSServiceProcessResult(), which will extract the daemon's * reply from the socket, and pass it to the appropriate application callback. By using a run * loop or select(), results from the daemon can be processed asynchronously. Alternatively, * a client can choose to fork a thread and have it loop calling "DNSServiceProcessResult(ref);" * If DNSServiceProcessResult() is called when no data is available for reading on the socket, it * will block until data does become available, and then process the data and return to the caller. * The application is responsible for checking the return value of DNSServiceProcessResult() * to determine if the socket is valid and if it should continue to process data on the socket. * When data arrives on the socket, the client is responsible for calling DNSServiceProcessResult(ref) * in a timely fashion -- if the client allows a large backlog of data to build up the daemon * may terminate the connection. * * sdRef: A DNSServiceRef initialized by any of the DNSService calls. * * return value: The DNSServiceRef's underlying socket descriptor, or -1 on * error. */ DNSSD_EXPORT dnssd_sock_t DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef); /* DNSServiceProcessResult() * * Read a reply from the daemon, calling the appropriate application callback. This call will * block until the daemon's response is received. Use DNSServiceRefSockFD() in * conjunction with a run loop or select() to determine the presence of a response from the * server before calling this function to process the reply without blocking. Call this function * at any point if it is acceptable to block until the daemon's response arrives. Note that the * client is responsible for ensuring that DNSServiceProcessResult() is called whenever there is * a reply from the daemon - the daemon may terminate its connection with a client that does not * process the daemon's responses. * * sdRef: A DNSServiceRef initialized by any of the DNSService calls * that take a callback parameter. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns * an error code indicating the specific failure that occurred. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef); /* DNSServiceRefDeallocate() * * Terminate a connection with the daemon and free memory associated with the DNSServiceRef. * Any services or records registered with this DNSServiceRef will be deregistered. Any * Browse, Resolve, or Query operations called with this reference will be terminated. * * Note: If the reference's underlying socket is used in a run loop or select() call, it should * be removed BEFORE DNSServiceRefDeallocate() is called, as this function closes the reference's * socket. * * Note: If the reference was initialized with DNSServiceCreateConnection(), any DNSRecordRefs * created via this reference will be invalidated by this call - the resource records are * deregistered, and their DNSRecordRefs may not be used in subsequent functions. Similarly, * if the reference was initialized with DNSServiceRegister, and an extra resource record was * added to the service via DNSServiceAddRecord(), the DNSRecordRef created by the Add() call * is invalidated when this function is called - the DNSRecordRef may not be used in subsequent * functions. * * If the reference was passed to DNSServiceSetDispatchQueue(), DNSServiceRefDeallocate() must * be called on the same queue originally passed as an argument to DNSServiceSetDispatchQueue(). * * Note: This call is to be used only with the DNSServiceRef defined by this API. * * sdRef: A DNSServiceRef initialized by any of the DNSService calls. * */ DNSSD_EXPORT void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef); /********************************************************************************************* * * Domain Enumeration * *********************************************************************************************/ /* DNSServiceEnumerateDomains() * * Asynchronously enumerate domains available for browsing and registration. * * The enumeration MUST be cancelled via DNSServiceRefDeallocate() when no more domains * are to be found. * * Note that the names returned are (like all of DNS-SD) UTF-8 strings, * and are escaped using standard DNS escaping rules. * (See "Notes on DNS Name Escaping" earlier in this file for more details.) * A graphical browser displaying a hierarchical tree-structured view should cut * the names at the bare dots to yield individual labels, then de-escape each * label according to the escaping rules, and then display the resulting UTF-8 text. * * DNSServiceDomainEnumReply Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceEnumerateDomains(). * * flags: Possible values are: * kDNSServiceFlagsMoreComing * kDNSServiceFlagsAdd * kDNSServiceFlagsDefault * * interfaceIndex: Specifies the interface on which the domain exists. (The index for a given * interface is determined via the if_nametoindex() family of calls.) * * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise indicates * the failure that occurred (other parameters are undefined if errorCode is nonzero). * * replyDomain: The name of the domain. * * context: The context pointer passed to DNSServiceEnumerateDomains. * */ typedef void (DNSSD_API *DNSServiceDomainEnumReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *replyDomain, void *context ); /* DNSServiceEnumerateDomains() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the enumeration operation * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * kDNSServiceFlagsBrowseDomains to enumerate domains recommended for browsing. * kDNSServiceFlagsRegistrationDomains to enumerate domains recommended * for registration. * * interfaceIndex: If non-zero, specifies the interface on which to look for domains. * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Most applications will pass 0 to enumerate domains on * all interfaces. See "Constants for specifying an interface index" for more details. * * callBack: The function to be called when a domain is found or the call asynchronously * fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is not invoked and the DNSServiceRef * is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceDomainEnumReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Service Registration * *********************************************************************************************/ /* Register a service that is discovered via Browse() and Resolve() calls. * * DNSServiceRegisterReply() Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceRegister(). * * flags: When a name is successfully registered, the callback will be * invoked with the kDNSServiceFlagsAdd flag set. When Wide-Area * DNS-SD is in use, it is possible for a single service to get * more than one success callback (e.g. one in the "local" multicast * DNS domain, and another in a wide-area unicast DNS domain). * If a successfully-registered name later suffers a name conflict * or similar problem and has to be deregistered, the callback will * be invoked with the kDNSServiceFlagsAdd flag not set. The callback * is *not* invoked in the case where the caller explicitly terminates * the service registration by calling DNSServiceRefDeallocate(ref); * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred (including name conflicts, * if the kDNSServiceFlagsNoAutoRename flag was used when registering.) * Other parameters are undefined if errorCode is nonzero. * * name: The service name registered (if the application did not specify a name in * DNSServiceRegister(), this indicates what name was automatically chosen). * * regtype: The type of service registered, as it was passed to the callout. * * domain: The domain on which the service was registered (if the application did not * specify a domain in DNSServiceRegister(), this indicates the default domain * on which the service was registered). * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceRegisterReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, DNSServiceErrorType errorCode, const char *name, const char *regtype, const char *domain, void *context ); /* DNSServiceRegister() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the service registration * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * Other flags indicate the renaming behavior on name conflict * (not required for most applications). * See flag definitions above for details. * * interfaceIndex: If non-zero, specifies the interface on which to register the service * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Most applications will pass 0 to register on all * available interfaces. See "Constants for specifying an interface index" for more details. * * name: If non-NULL, specifies the service name to be registered. * Most applications will not specify a name, in which case the computer * name is used (this name is communicated to the client via the callback). * If a name is specified, it must be 1-63 bytes of UTF-8 text. * If the name is longer than 63 bytes it will be automatically truncated * to a legal length, unless the NoAutoRename flag is set, * in which case kDNSServiceErr_BadParam will be returned. * * regtype: The service type followed by the protocol, separated by a dot * (e.g. "_ftp._tcp"). The service type must be an underscore, followed * by 1-15 characters, which may be letters, digits, or hyphens. * The transport protocol must be "_tcp" or "_udp". New service types * should be registered at . * * Additional subtypes of the primary service type (where a service * type has defined subtypes) follow the primary service type in a * comma-separated list, with no additional spaces, e.g. * "_primarytype._tcp,_subtype1,_subtype2,_subtype3" * Subtypes provide a mechanism for filtered browsing: A client browsing * for "_primarytype._tcp" will discover all instances of this type; * a client browsing for "_primarytype._tcp,_subtype2" will discover only * those instances that were registered with "_subtype2" in their list of * registered subtypes. * * The subtype mechanism can be illustrated with some examples using the * dns-sd command-line tool: * * % dns-sd -R Simple _test._tcp "" 1001 & * % dns-sd -R Better _test._tcp,HasFeatureA "" 1002 & * % dns-sd -R Best _test._tcp,HasFeatureA,HasFeatureB "" 1003 & * * Now: * % dns-sd -B _test._tcp # will find all three services * % dns-sd -B _test._tcp,HasFeatureA # finds "Better" and "Best" * % dns-sd -B _test._tcp,HasFeatureB # finds only "Best" * * Subtype labels may be up to 63 bytes long, and may contain any eight- * bit byte values, including zero bytes. However, due to the nature of * using a C-string-based API, conventional DNS escaping must be used for * dots ('.'), commas (','), backslashes ('\') and zero bytes, as shown below: * * % dns-sd -R Test '_test._tcp,s\.one,s\,two,s\\three,s\000four' local 123 * * domain: If non-NULL, specifies the domain on which to advertise the service. * Most applications will not specify a domain, instead automatically * registering in the default domain(s). * * host: If non-NULL, specifies the SRV target host name. Most applications * will not specify a host, instead automatically using the machine's * default host name(s). Note that specifying a non-NULL host does NOT * create an address record for that host - the application is responsible * for ensuring that the appropriate address record exists, or creating it * via DNSServiceRegisterRecord(). * * port: The port, in network byte order, on which the service accepts connections. * Pass 0 for a "placeholder" service (i.e. a service that will not be discovered * by browsing, but will cause a name conflict if another client tries to * register that same name). Most clients will not use placeholder services. * * txtLen: The length of the txtRecord, in bytes. Must be zero if the txtRecord is NULL. * * txtRecord: The TXT record rdata. A non-NULL txtRecord MUST be a properly formatted DNS * TXT record, i.e. ... * Passing NULL for the txtRecord is allowed as a synonym for txtLen=1, txtRecord="", * i.e. it creates a TXT record of length one containing a single empty string. * RFC 1035 doesn't allow a TXT record to contain *zero* strings, so a single empty * string is the smallest legal DNS TXT record. * As with the other parameters, the DNSServiceRegister call copies the txtRecord * data; e.g. if you allocated the storage for the txtRecord parameter with malloc() * then you can safely free that memory right after the DNSServiceRegister call returns. * * callBack: The function to be called when the registration completes or asynchronously * fails. The client MAY pass NULL for the callback - The client will NOT be notified * of the default values picked on its behalf, and the client will NOT be notified of any * asynchronous errors (e.g. out of memory errors, etc.) that may prevent the registration * of the service. The client may NOT pass the NoAutoRename flag if the callback is NULL. * The client may still deregister the service at any time via DNSServiceRefDeallocate(). * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSServiceRef * is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceRegister ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, /* may be NULL */ const char *regtype, const char *domain, /* may be NULL */ const char *host, /* may be NULL */ uint16_t port, /* In network byte order */ uint16_t txtLen, const void *txtRecord, /* may be NULL */ DNSServiceRegisterReply callBack, /* may be NULL */ void *context /* may be NULL */ ); /* DNSServiceAddRecord() * * Add a record to a registered service. The name of the record will be the same as the * registered service's name. * The record can later be updated or deregistered by passing the RecordRef initialized * by this function to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). * * Note that the DNSServiceAddRecord/UpdateRecord/RemoveRecord are *NOT* thread-safe * with respect to a single DNSServiceRef. If you plan to have multiple threads * in your program simultaneously add, update, or remove records from the same * DNSServiceRef, then it's the caller's responsibility to use a mutex lock * or take similar appropriate precautions to serialize those calls. * * Parameters; * * sdRef: A DNSServiceRef initialized by DNSServiceRegister(). * * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). * If the above DNSServiceRef is passed to DNSServiceRefDeallocate(), RecordRef is also * invalidated and may not be used further. * * flags: Currently ignored, reserved for future use. * * rrtype: The type of the record (e.g. kDNSServiceType_TXT, kDNSServiceType_SRV, etc) * * rdlen: The length, in bytes, of the rdata. * * rdata: The raw rdata to be contained in the added resource record. * * ttl: The time to live of the resource record, in seconds. * Most clients should pass 0 to indicate that the system should * select a sensible default value. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an * error code indicating the error that occurred (the RecordRef is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceAddRecord ( DNSServiceRef sdRef, DNSRecordRef *RecordRef, DNSServiceFlags flags, uint16_t rrtype, uint16_t rdlen, const void *rdata, uint32_t ttl ); /* DNSServiceUpdateRecord * * Update a registered resource record. The record must either be: * - The primary txt record of a service registered via DNSServiceRegister() * - A record added to a registered service via DNSServiceAddRecord() * - An individual record registered by DNSServiceRegisterRecord() * * Parameters: * * sdRef: A DNSServiceRef that was initialized by DNSServiceRegister() * or DNSServiceCreateConnection(). * * RecordRef: A DNSRecordRef initialized by DNSServiceAddRecord, or NULL to update the * service's primary txt record. * * flags: Currently ignored, reserved for future use. * * rdlen: The length, in bytes, of the new rdata. * * rdata: The new rdata to be contained in the updated resource record. * * ttl: The time to live of the updated resource record, in seconds. * Most clients should pass 0 to indicate that the system should * select a sensible default value. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an * error code indicating the error that occurred. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord ( DNSServiceRef sdRef, DNSRecordRef RecordRef, /* may be NULL */ DNSServiceFlags flags, uint16_t rdlen, const void *rdata, uint32_t ttl ); /* DNSServiceRemoveRecord * * Remove a record previously added to a service record set via DNSServiceAddRecord(), or deregister * a record registered individually via DNSServiceRegisterRecord(). * * Parameters: * * sdRef: A DNSServiceRef initialized by DNSServiceRegister() (if the * record being removed was registered via DNSServiceAddRecord()) or by * DNSServiceCreateConnection() (if the record being removed was registered via * DNSServiceRegisterRecord()). * * recordRef: A DNSRecordRef initialized by a successful call to DNSServiceAddRecord() * or DNSServiceRegisterRecord(). * * flags: Currently ignored, reserved for future use. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an * error code indicating the error that occurred. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord ( DNSServiceRef sdRef, DNSRecordRef RecordRef, DNSServiceFlags flags ); /********************************************************************************************* * * Service Discovery * *********************************************************************************************/ /* Browse for instances of a service. * * DNSServiceBrowseReply() Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceBrowse(). * * flags: Possible values are kDNSServiceFlagsMoreComing and kDNSServiceFlagsAdd. * See flag definitions for details. * * interfaceIndex: The interface on which the service is advertised. This index should * be passed to DNSServiceResolve() when resolving the service. * * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will * indicate the failure that occurred. Other parameters are undefined if * the errorCode is nonzero. * * serviceName: The discovered service name. This name should be displayed to the user, * and stored for subsequent use in the DNSServiceResolve() call. * * regtype: The service type, which is usually (but not always) the same as was passed * to DNSServiceBrowse(). One case where the discovered service type may * not be the same as the requested service type is when using subtypes: * The client may want to browse for only those ftp servers that allow * anonymous connections. The client will pass the string "_ftp._tcp,_anon" * to DNSServiceBrowse(), but the type of the service that's discovered * is simply "_ftp._tcp". The regtype for each discovered service instance * should be stored along with the name, so that it can be passed to * DNSServiceResolve() when the service is later resolved. * * domain: The domain of the discovered service instance. This may or may not be the * same as the domain that was passed to DNSServiceBrowse(). The domain for each * discovered service instance should be stored along with the name, so that * it can be passed to DNSServiceResolve() when the service is later resolved. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceBrowseReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *serviceName, const char *regtype, const char *replyDomain, void *context ); /* DNSServiceBrowse() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the browse operation * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * * interfaceIndex: If non-zero, specifies the interface on which to browse for services * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Most applications will pass 0 to browse on all available * interfaces. See "Constants for specifying an interface index" for more details. * * regtype: The service type being browsed for followed by the protocol, separated by a * dot (e.g. "_ftp._tcp"). The transport protocol must be "_tcp" or "_udp". * A client may optionally specify a single subtype to perform filtered browsing: * e.g. browsing for "_primarytype._tcp,_subtype" will discover only those * instances of "_primarytype._tcp" that were registered specifying "_subtype" * in their list of registered subtypes. * * domain: If non-NULL, specifies the domain on which to browse for services. * Most applications will not specify a domain, instead browsing on the * default domain(s). * * callBack: The function to be called when an instance of the service being browsed for * is found, or if the call asynchronously fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is not invoked and the DNSServiceRef * is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceBrowse ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *regtype, const char *domain, /* may be NULL */ DNSServiceBrowseReply callBack, void *context /* may be NULL */ ); /* DNSServiceResolve() * * Resolve a service name discovered via DNSServiceBrowse() to a target host name, port number, and * txt record. * * Note: Applications should NOT use DNSServiceResolve() solely for txt record monitoring - use * DNSServiceQueryRecord() instead, as it is more efficient for this task. * * Note: When the desired results have been returned, the client MUST terminate the resolve by calling * DNSServiceRefDeallocate(). * * Note: DNSServiceResolve() behaves correctly for typical services that have a single SRV record * and a single TXT record. To resolve non-standard services with multiple SRV or TXT records, * DNSServiceQueryRecord() should be used. * * DNSServiceResolveReply Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceResolve(). * * flags: Possible values: kDNSServiceFlagsMoreComing * * interfaceIndex: The interface on which the service was resolved. * * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will * indicate the failure that occurred. Other parameters are undefined if * the errorCode is nonzero. * * fullname: The full service domain name, in the form ... * (This name is escaped following standard DNS rules, making it suitable for * passing to standard system DNS APIs such as res_query(), or to the * special-purpose functions included in this API that take fullname parameters. * See "Notes on DNS Name Escaping" earlier in this file for more details.) * * hosttarget: The target hostname of the machine providing the service. This name can * be passed to functions like gethostbyname() to identify the host's IP address. * * port: The port, in network byte order, on which connections are accepted for this service. * * txtLen: The length of the txt record, in bytes. * * txtRecord: The service's primary txt record, in standard txt record format. * * context: The context pointer that was passed to the callout. * * NOTE: In earlier versions of this header file, the txtRecord parameter was declared "const char *" * This is incorrect, since it contains length bytes which are values in the range 0 to 255, not -128 to +127. * Depending on your compiler settings, this change may cause signed/unsigned mismatch warnings. * These should be fixed by updating your own callback function definition to match the corrected * function signature using "const unsigned char *txtRecord". Making this change may also fix inadvertent * bugs in your callback function, where it could have incorrectly interpreted a length byte with value 250 * as being -6 instead, with various bad consequences ranging from incorrect operation to software crashes. * If you need to maintain portable code that will compile cleanly with both the old and new versions of * this header file, you should update your callback function definition to use the correct unsigned value, * and then in the place where you pass your callback function to DNSServiceResolve(), use a cast to eliminate * the compiler warning, e.g.: * DNSServiceResolve(sd, flags, index, name, regtype, domain, (DNSServiceResolveReply)MyCallback, context); * This will ensure that your code compiles cleanly without warnings (and more importantly, works correctly) * with both the old header and with the new corrected version. * */ typedef void (DNSSD_API *DNSServiceResolveReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t port, /* In network byte order */ uint16_t txtLen, const unsigned char *txtRecord, void *context ); /* DNSServiceResolve() Parameters * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the resolve operation * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * Specifying kDNSServiceFlagsForceMulticast will cause query to be * performed with a link-local mDNS query, even if the name is an * apparently non-local name (i.e. a name not ending in ".local.") * * interfaceIndex: The interface on which to resolve the service. If this resolve call is * as a result of a currently active DNSServiceBrowse() operation, then the * interfaceIndex should be the index reported in the DNSServiceBrowseReply * callback. If this resolve call is using information previously saved * (e.g. in a preference file) for later use, then use interfaceIndex 0, because * the desired service may now be reachable via a different physical interface. * See "Constants for specifying an interface index" for more details. * * name: The name of the service instance to be resolved, as reported to the * DNSServiceBrowseReply() callback. * * regtype: The type of the service instance to be resolved, as reported to the * DNSServiceBrowseReply() callback. * * domain: The domain of the service instance to be resolved, as reported to the * DNSServiceBrowseReply() callback. * * callBack: The function to be called when a result is found, or if the call * asynchronously fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSServiceRef * is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceResolve ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, const char *regtype, const char *domain, DNSServiceResolveReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Querying Individual Specific Records * *********************************************************************************************/ /* DNSServiceQueryRecord * * Query for an arbitrary DNS record. * * DNSServiceQueryRecordReply() Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceQueryRecord(). * * flags: Possible values are kDNSServiceFlagsMoreComing and * kDNSServiceFlagsAdd. The Add flag is NOT set for PTR records * with a ttl of 0, i.e. "Remove" events. * * interfaceIndex: The interface on which the query was resolved (the index for a given * interface is determined via the if_nametoindex() family of calls). * See "Constants for specifying an interface index" for more details. * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred. Other parameters are undefined if * errorCode is nonzero. * * fullname: The resource record's full domain name. * * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN). * * rdlen: The length, in bytes, of the resource record rdata. * * rdata: The raw rdata of the resource record. * * ttl: If the client wishes to cache the result for performance reasons, * the TTL indicates how long the client may legitimately hold onto * this result, in seconds. After the TTL expires, the client should * consider the result no longer valid, and if it requires this data * again, it should be re-fetched with a new query. Of course, this * only applies to clients that cancel the asynchronous operation when * they get a result. Clients that leave the asynchronous operation * running can safely assume that the data remains valid until they * get another callback telling them otherwise. The ttl value is not * updated when the daemon answers from the cache, hence relying on * the accuracy of the ttl value is not recommended. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceQueryRecordReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, void *context ); /* DNSServiceQueryRecord() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the query operation * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast * query to a unicast DNS server that implements the protocol. This flag * has no effect on link-local multicast queries. * * interfaceIndex: If non-zero, specifies the interface on which to issue the query * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Passing 0 causes the name to be queried for on all * interfaces. See "Constants for specifying an interface index" for more details. * * fullname: The full domain name of the resource record to be queried for. * * rrtype: The numerical type of the resource record to be queried for * (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN). * * callBack: The function to be called when a result is found, or if the call * asynchronously fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSServiceRef * is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceQueryRecord ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, DNSServiceQueryRecordReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Unified lookup of both IPv4 and IPv6 addresses for a fully qualified hostname * *********************************************************************************************/ /* DNSServiceGetAddrInfo * * Queries for the IP address of a hostname by using either Multicast or Unicast DNS. * * DNSServiceGetAddrInfoReply() parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceGetAddrInfo(). * * flags: Possible values are kDNSServiceFlagsMoreComing and * kDNSServiceFlagsAdd. * * interfaceIndex: The interface to which the answers pertain. * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred. Other parameters are * undefined if errorCode is nonzero. * * hostname: The fully qualified domain name of the host to be queried for. * * address: IPv4 or IPv6 address. * * ttl: If the client wishes to cache the result for performance reasons, * the TTL indicates how long the client may legitimately hold onto * this result, in seconds. After the TTL expires, the client should * consider the result no longer valid, and if it requires this data * again, it should be re-fetched with a new query. Of course, this * only applies to clients that cancel the asynchronous operation when * they get a result. Clients that leave the asynchronous operation * running can safely assume that the data remains valid until they * get another callback telling them otherwise. The ttl value is not * updated when the daemon answers from the cache, hence relying on * the accuracy of the ttl value is not recommended. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceGetAddrInfoReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *hostname, const struct sockaddr *address, uint32_t ttl, void *context ); /* DNSServiceGetAddrInfo() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the address query operation * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * kDNSServiceFlagsForceMulticast * * interfaceIndex: The interface on which to issue the query. Passing 0 causes the query to be * sent on all active interfaces via Multicast or the primary interface via Unicast. * * protocol: Pass in kDNSServiceProtocol_IPv4 to look up IPv4 addresses, or kDNSServiceProtocol_IPv6 * to look up IPv6 addresses, or both to look up both kinds. If neither flag is * set, the system will apply an intelligent heuristic, which is (currently) * that it will attempt to look up both, except: * * * If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) * but this host has no routable IPv6 address, then the call will not try to * look up IPv6 addresses for "hostname", since any addresses it found would be * unlikely to be of any use anyway. Similarly, if this host has no routable * IPv4 address, the call will not try to look up IPv4 addresses for "hostname". * * hostname: The fully qualified domain name of the host to be queried for. * * callBack: The function to be called when the query succeeds or fails asynchronously. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceProtocol protocol, const char *hostname, DNSServiceGetAddrInfoReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Special Purpose Calls: * DNSServiceCreateConnection(), DNSServiceRegisterRecord(), DNSServiceReconfirmRecord() * (most applications will not use these) * *********************************************************************************************/ /* DNSServiceCreateConnection() * * Create a connection to the daemon allowing efficient registration of * multiple individual records. * * Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. * Deallocating the reference (via DNSServiceRefDeallocate()) * severs the connection and cancels all operations and * deregisters all records registered on this connection. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns * an error code indicating the specific failure that occurred * (in which case the DNSServiceRef is not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef); /* DNSServiceRegisterRecord * * Register an individual resource record on a connected DNSServiceRef. * * Note that name conflicts occurring for records registered via this call must be handled * by the client in the callback. * * DNSServiceRegisterRecordReply() parameters: * * sdRef: The connected DNSServiceRef initialized by * DNSServiceCreateConnection(). * * RecordRef: The DNSRecordRef initialized by DNSServiceRegisterRecord(). If the above * DNSServiceRef is passed to DNSServiceRefDeallocate(), this DNSRecordRef is * invalidated, and may not be used further. * * flags: Currently unused, reserved for future use. * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred (including name conflicts.) * Other parameters are undefined if errorCode is nonzero. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceRegisterRecordReply) ( DNSServiceRef sdRef, DNSRecordRef RecordRef, DNSServiceFlags flags, DNSServiceErrorType errorCode, void *context ); /* DNSServiceRegisterRecord() Parameters: * * sdRef: A DNSServiceRef initialized by DNSServiceCreateConnection(). * * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). * (To deregister ALL records registered on a single connected DNSServiceRef * and deallocate each of their corresponding DNSServiceRecordRefs, call * DNSServiceRefDeallocate()). * * flags: One of either kDNSServiceFlagsShared, kDNSServiceFlagsUnique or kDNSServiceFlagsKnownUnique must be set. * * interfaceIndex: If non-zero, specifies the interface on which to register the record * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Passing 0 causes the record to be registered on all interfaces. * See "Constants for specifying an interface index" for more details. * * fullname: The full domain name of the resource record. * * rrtype: The numerical type of the resource record (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN) * * rdlen: Length, in bytes, of the rdata. * * rdata: A pointer to the raw rdata, as it is to appear in the DNS record. * * ttl: The time to live of the resource record, in seconds. * Most clients should pass 0 to indicate that the system should * select a sensible default value. * * callBack: The function to be called when a result is found, or if the call * asynchronously fails (e.g. because of a name conflict.) * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSRecordRef is * not initialized). */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord ( DNSServiceRef sdRef, DNSRecordRef *RecordRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, DNSServiceRegisterRecordReply callBack, void *context /* may be NULL */ ); /* DNSServiceReconfirmRecord * * Instruct the daemon to verify the validity of a resource record that appears * to be out of date (e.g. because TCP connection to a service's target failed.) * Causes the record to be flushed from the daemon's cache (as well as all other * daemons' caches on the network) if the record is determined to be invalid. * Use this routine conservatively. Reconfirming a record necessarily consumes * network bandwidth, so this should not be done indiscriminately. * * Parameters: * * flags: Not currently used. * * interfaceIndex: Specifies the interface of the record in question. * The caller must specify the interface. * This API (by design) causes increased network traffic, so it requires * the caller to be precise about which record should be reconfirmed. * It is not possible to pass zero for the interface index to perform * a "wildcard" reconfirmation, where *all* matching records are reconfirmed. * * fullname: The resource record's full domain name. * * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN). * * rdlen: The length, in bytes, of the resource record rdata. * * rdata: The raw rdata of the resource record. * */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord ( DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata ); /********************************************************************************************* * * NAT Port Mapping * *********************************************************************************************/ /* DNSServiceNATPortMappingCreate * * Request a port mapping in the NAT gateway, which maps a port on the local machine * to an external port on the NAT. The NAT should support either PCP, NAT-PMP or the * UPnP/IGD protocol for this API to create a successful mapping. Note that this API * currently supports IPv4 addresses/mappings only. If the NAT gateway supports PCP and * returns an IPv6 address (incorrectly, since this API specifically requests IPv4 * addresses), the DNSServiceNATPortMappingReply callback will be invoked with errorCode * kDNSServiceErr_NATPortMappingUnsupported. * * The port mapping will be renewed indefinitely until the client process exits, or * explicitly terminates the port mapping request by calling DNSServiceRefDeallocate(). * The client callback will be invoked, informing the client of the NAT gateway's * external IP address and the external port that has been allocated for this client. * The client should then record this external IP address and port using whatever * directory service mechanism it is using to enable peers to connect to it. * (Clients advertising services using Wide-Area DNS-SD DO NOT need to use this API * -- when a client calls DNSServiceRegister() NAT mappings are automatically created * and the external IP address and port for the service are recorded in the global DNS. * Only clients using some directory mechanism other than Wide-Area DNS-SD need to use * this API to explicitly map their own ports.) * * It's possible that the client callback could be called multiple times, for example * if the NAT gateway's IP address changes, or if a configuration change results in a * different external port being mapped for this client. Over the lifetime of any long-lived * port mapping, the client should be prepared to handle these notifications of changes * in the environment, and should update its recorded address and/or port as appropriate. * * NOTE: There are two unusual aspects of how the DNSServiceNATPortMappingCreate API works, * which were intentionally designed to help simplify client code: * * 1. It's not an error to request a NAT mapping when the machine is not behind a NAT gateway. * In other NAT mapping APIs, if you request a NAT mapping and the machine is not behind a NAT * gateway, then the API returns an error code -- it can't get you a NAT mapping if there's no * NAT gateway. The DNSServiceNATPortMappingCreate API takes a different view. Working out * whether or not you need a NAT mapping can be tricky and non-obvious, particularly on * a machine with multiple active network interfaces. Rather than make every client recreate * this logic for deciding whether a NAT mapping is required, the PortMapping API does that * work for you. If the client calls the PortMapping API when the machine already has a * routable public IP address, then instead of complaining about it and giving an error, * the PortMapping API just invokes your callback, giving the machine's public address * and your own port number. This means you don't need to write code to work out whether * your client needs to call the PortMapping API -- just call it anyway, and if it wasn't * necessary, no harm is done: * * - If the machine already has a routable public IP address, then your callback * will just be invoked giving your own address and port. * - If a NAT mapping is required and obtained, then your callback will be invoked * giving you the external address and port. * - If a NAT mapping is required but not obtained from the local NAT gateway, * or the machine has no network connectivity, then your callback will be * invoked giving zero address and port. * * 2. In other NAT mapping APIs, if a laptop computer is put to sleep and woken up on a new * network, it's the client's job to notice this, and work out whether a NAT mapping * is required on the new network, and make a new NAT mapping request if necessary. * The DNSServiceNATPortMappingCreate API does this for you, automatically. * The client just needs to make one call to the PortMapping API, and its callback will * be invoked any time the mapping state changes. This property complements point (1) above. * If the client didn't make a NAT mapping request just because it determined that one was * not required at that particular moment in time, the client would then have to monitor * for network state changes to determine if a NAT port mapping later became necessary. * By unconditionally making a NAT mapping request, even when a NAT mapping not to be * necessary, the PortMapping API will then begin monitoring network state changes on behalf of * the client, and if a NAT mapping later becomes necessary, it will automatically create a NAT * mapping and inform the client with a new callback giving the new address and port information. * * DNSServiceNATPortMappingReply() parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceNATPortMappingCreate(). * * flags: Currently unused, reserved for future use. * * interfaceIndex: The interface through which the NAT gateway is reached. * * errorCode: Will be kDNSServiceErr_NoError on success. * Will be kDNSServiceErr_DoubleNAT when the NAT gateway is itself behind one or * more layers of NAT, in which case the other parameters have the defined values. * For other failures, will indicate the failure that occurred, and the other * parameters are undefined. * * externalAddress: Four byte IPv4 address in network byte order. * * protocol: Will be kDNSServiceProtocol_UDP or kDNSServiceProtocol_TCP or both. * * internalPort: The port on the local machine that was mapped. * * externalPort: The actual external port in the NAT gateway that was mapped. * This is likely to be different than the requested external port. * * ttl: The lifetime of the NAT port mapping created on the gateway. * This controls how quickly stale mappings will be garbage-collected * if the client machine crashes, suffers a power failure, is disconnected * from the network, or suffers some other unfortunate demise which * causes it to vanish without explicitly removing its NAT port mapping. * It's possible that the ttl value will differ from the requested ttl value. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceNATPortMappingReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, uint32_t externalAddress, /* four byte IPv4 address in network byte order */ DNSServiceProtocol protocol, uint16_t internalPort, /* In network byte order */ uint16_t externalPort, /* In network byte order and may be different than the requested port */ uint32_t ttl, /* may be different than the requested ttl */ void *context ); /* DNSServiceNATPortMappingCreate() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef * (or, if the kDNSServiceFlagsShareConnection flag is used, * a copy of the shared connection reference that is to be used). * If the call succeeds then it initializes (or updates) the DNSServiceRef, * returns kDNSServiceErr_NoError, and the NAT port mapping * will remain active indefinitely until the client terminates it * by passing this DNSServiceRef to DNSServiceRefDeallocate() * (or by closing the underlying shared connection, if used). * * flags: Possible values are: * kDNSServiceFlagsShareConnection to use a shared connection. * * interfaceIndex: The interface on which to create port mappings in a NAT gateway. * Passing 0 causes the port mapping request to be sent on the primary interface. * * protocol: To request a port mapping, pass in kDNSServiceProtocol_UDP, or kDNSServiceProtocol_TCP, * or (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP) to map both. * The local listening port number must also be specified in the internalPort parameter. * To just discover the NAT gateway's external IP address, pass zero for protocol, * internalPort, externalPort and ttl. * * internalPort: The port number in network byte order on the local machine which is listening for packets. * * externalPort: The requested external port in network byte order in the NAT gateway that you would * like to map to the internal port. Pass 0 if you don't care which external port is chosen for you. * * ttl: The requested renewal period of the NAT port mapping, in seconds. * If the client machine crashes, suffers a power failure, is disconnected from * the network, or suffers some other unfortunate demise which causes it to vanish * unexpectedly without explicitly removing its NAT port mappings, then the NAT gateway * will garbage-collect old stale NAT port mappings when their lifetime expires. * Requesting a short TTL causes such orphaned mappings to be garbage-collected * more promptly, but consumes system resources and network bandwidth with * frequent renewal packets to keep the mapping from expiring. * Requesting a long TTL is more efficient on the network, but in the event of the * client vanishing, stale NAT port mappings will not be garbage-collected as quickly. * Most clients should pass 0 to use a system-wide default value. * * callBack: The function to be called when the port mapping request succeeds or fails asynchronously. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred. * * If you don't actually want a port mapped, and are just calling the API * because you want to find out the NAT's external IP address (e.g. for UI * display) then pass zero for protocol, internalPort, externalPort and ttl. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceProtocol protocol, /* TCP and/or UDP */ uint16_t internalPort, /* network byte order */ uint16_t externalPort, /* network byte order */ uint32_t ttl, /* time to live in seconds */ DNSServiceNATPortMappingReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * General Utility Functions * *********************************************************************************************/ /* DNSServiceConstructFullName() * * Concatenate a three-part domain name (as returned by the above callbacks) into a * properly-escaped full domain name. Note that callbacks in the above functions ALREADY ESCAPE * strings where necessary. * * Parameters: * * fullName: A pointer to a buffer that where the resulting full domain name is to be written. * The buffer must be kDNSServiceMaxDomainName (1009) bytes in length to * accommodate the longest legal domain name without buffer overrun. * * service: The service name - any dots or backslashes must NOT be escaped. * May be NULL (to construct a PTR record name, e.g. * "_ftp._tcp.apple.com."). * * regtype: The service type followed by the protocol, separated by a dot * (e.g. "_ftp._tcp"). * * domain: The domain name, e.g. "apple.com.". Literal dots or backslashes, * if any, must be escaped, e.g. "1st\. Floor.apple.com." * * return value: Returns kDNSServiceErr_NoError (0) on success, kDNSServiceErr_BadParam on error. * */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceConstructFullName ( char * const fullName, const char * const service, /* may be NULL */ const char * const regtype, const char * const domain ); /********************************************************************************************* * * TXT Record Construction Functions * *********************************************************************************************/ /* * A typical calling sequence for TXT record construction is something like: * * Client allocates storage for TXTRecord data (e.g. declare buffer on the stack) * TXTRecordCreate(); * TXTRecordSetValue(); * TXTRecordSetValue(); * TXTRecordSetValue(); * ... * DNSServiceRegister( ... TXTRecordGetLength(), TXTRecordGetBytesPtr() ... ); * TXTRecordDeallocate(); * Explicitly deallocate storage for TXTRecord data (if not allocated on the stack) */ /* TXTRecordRef * * Opaque internal data type. * Note: Represents a DNS-SD TXT record. */ typedef union _TXTRecordRef_t { char PrivateData[16]; char *ForceNaturalAlignment; } TXTRecordRef; /* TXTRecordCreate() * * Creates a new empty TXTRecordRef referencing the specified storage. * * If the buffer parameter is NULL, or the specified storage size is not * large enough to hold a key subsequently added using TXTRecordSetValue(), * then additional memory will be added as needed using malloc(). Note that * an existing TXT record buffer should not be passed to TXTRecordCreate * to create a copy of another TXT Record. The correct way to copy TXTRecordRef * is creating an empty TXTRecordRef with TXTRecordCreate() first, and using * TXTRecordSetValue to set the same value. * * On some platforms, when memory is low, malloc() may fail. In this * case, TXTRecordSetValue() will return kDNSServiceErr_NoMemory, and this * error condition will need to be handled as appropriate by the caller. * * You can avoid the need to handle this error condition if you ensure * that the storage you initially provide is large enough to hold all * the key/value pairs that are to be added to the record. * The caller can precompute the exact length required for all of the * key/value pairs to be added, or simply provide a fixed-sized buffer * known in advance to be large enough. * A no-value (key-only) key requires (1 + key length) bytes. * A key with empty value requires (1 + key length + 1) bytes. * A key with non-empty value requires (1 + key length + 1 + value length). * For most applications, DNS-SD TXT records are generally * less than 100 bytes, so in most cases a simple fixed-sized * 256-byte buffer will be more than sufficient. * Recommended size limits for DNS-SD TXT Records are discussed in RFC 6763 * * * Note: When passing parameters to and from these TXT record APIs, * the key name does not include the '=' character. The '=' character * is the separator between the key and value in the on-the-wire * packet format; it is not part of either the key or the value. * * txtRecord: A pointer to an uninitialized TXTRecordRef. * * bufferLen: The size of the storage provided in the "buffer" parameter. * * buffer: Optional caller-supplied storage used to hold the TXTRecord data. * This storage must remain valid for as long as * the TXTRecordRef. */ DNSSD_EXPORT void DNSSD_API TXTRecordCreate ( TXTRecordRef *txtRecord, uint16_t bufferLen, void *buffer ); /* TXTRecordDeallocate() * * Releases any resources allocated in the course of preparing a TXT Record * using TXTRecordCreate()/TXTRecordSetValue()/TXTRecordRemoveValue(). * Ownership of the buffer provided in TXTRecordCreate() returns to the client. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * */ DNSSD_EXPORT void DNSSD_API TXTRecordDeallocate ( TXTRecordRef *txtRecord ); /* TXTRecordSetValue() * * Adds a key (optionally with value) to a TXTRecordRef. If the "key" already * exists in the TXTRecordRef, then the current value will be replaced with * the new value. * Keys may exist in four states with respect to a given TXT record: * - Absent (key does not appear at all) * - Present with no value ("key" appears alone) * - Present with empty value ("key=" appears in TXT record) * - Present with non-empty value ("key=value" appears in TXT record) * For more details refer to "Data Syntax for DNS-SD TXT Records" in RFC 6763 * * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * key: A null-terminated string which only contains printable ASCII * values (0x20-0x7E), excluding '=' (0x3D). Keys should be * 9 characters or fewer (not counting the terminating null). * * valueSize: The size of the value. * * value: Any binary value. For values that represent * textual data, UTF-8 is STRONGLY recommended. * For values that represent textual data, valueSize * should NOT include the terminating null (if any) * at the end of the string. * If NULL, then "key" will be added with no value. * If non-NULL but valueSize is zero, then "key=" will be * added with empty value. * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_Invalid if the "key" string contains * illegal characters. * Returns kDNSServiceErr_NoMemory if adding this key would * exceed the available storage. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API TXTRecordSetValue ( TXTRecordRef *txtRecord, const char *key, uint8_t valueSize, /* may be zero */ const void *value /* may be NULL */ ); /* TXTRecordRemoveValue() * * Removes a key from a TXTRecordRef. The "key" must be an * ASCII string which exists in the TXTRecordRef. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * key: A key name which exists in the TXTRecordRef. * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_NoSuchKey if the "key" does not * exist in the TXTRecordRef. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API TXTRecordRemoveValue ( TXTRecordRef *txtRecord, const char *key ); /* TXTRecordGetLength() * * Allows you to determine the length of the raw bytes within a TXTRecordRef. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * return value: Returns the size of the raw bytes inside a TXTRecordRef * which you can pass directly to DNSServiceRegister() or * to DNSServiceUpdateRecord(). * Returns 0 if the TXTRecordRef is empty. */ DNSSD_EXPORT uint16_t DNSSD_API TXTRecordGetLength ( const TXTRecordRef *txtRecord ); /* TXTRecordGetBytesPtr() * * Allows you to retrieve a pointer to the raw bytes within a TXTRecordRef. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * return value: Returns a pointer to the raw bytes inside the TXTRecordRef * which you can pass directly to DNSServiceRegister() or * to DNSServiceUpdateRecord(). */ DNSSD_EXPORT const void * DNSSD_API TXTRecordGetBytesPtr ( const TXTRecordRef *txtRecord ); /********************************************************************************************* * * TXT Record Parsing Functions * *********************************************************************************************/ /* * A typical calling sequence for TXT record parsing is something like: * * Receive TXT record data in DNSServiceResolve() callback * if (TXTRecordContainsKey(txtLen, txtRecord, "key")) then do something * val1ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key1", &len1); * val2ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key2", &len2); * ... * memcpy(myval1, val1ptr, len1); * memcpy(myval2, val2ptr, len2); * ... * return; * * If you wish to retain the values after return from the DNSServiceResolve() * callback, then you need to copy the data to your own storage using memcpy() * or similar, as shown in the example above. * * If for some reason you need to parse a TXT record you built yourself * using the TXT record construction functions above, then you can do * that using TXTRecordGetLength and TXTRecordGetBytesPtr calls: * TXTRecordGetValue(TXTRecordGetLength(x), TXTRecordGetBytesPtr(x), key, &len); * * Most applications only fetch keys they know about from a TXT record and * ignore the rest. * However, some debugging tools wish to fetch and display all keys. * To do that, use the TXTRecordGetCount() and TXTRecordGetItemAtIndex() calls. */ /* TXTRecordContainsKey() * * Allows you to determine if a given TXT Record contains a specified key. * * txtLen: The size of the received TXT Record. * * txtRecord: Pointer to the received TXT Record bytes. * * key: A null-terminated ASCII string containing the key name. * * return value: Returns 1 if the TXT Record contains the specified key. * Otherwise, it returns 0. */ DNSSD_EXPORT int DNSSD_API TXTRecordContainsKey ( uint16_t txtLen, const void *txtRecord, const char *key ); /* TXTRecordGetValuePtr() * * Allows you to retrieve the value for a given key from a TXT Record. * * txtLen: The size of the received TXT Record * * txtRecord: Pointer to the received TXT Record bytes. * * key: A null-terminated ASCII string containing the key name. * * valueLen: On output, will be set to the size of the "value" data. * * return value: Returns NULL if the key does not exist in this TXT record, * or exists with no value (to differentiate between * these two cases use TXTRecordContainsKey()). * Returns pointer to location within TXT Record bytes * if the key exists with empty or non-empty value. * For empty value, valueLen will be zero. * For non-empty value, valueLen will be length of value data. */ DNSSD_EXPORT const void * DNSSD_API TXTRecordGetValuePtr ( uint16_t txtLen, const void *txtRecord, const char *key, uint8_t *valueLen ); /* TXTRecordGetCount() * * Returns the number of keys stored in the TXT Record. The count * can be used with TXTRecordGetItemAtIndex() to iterate through the keys. * * txtLen: The size of the received TXT Record. * * txtRecord: Pointer to the received TXT Record bytes. * * return value: Returns the total number of keys in the TXT Record. * */ DNSSD_EXPORT uint16_t DNSSD_API TXTRecordGetCount ( uint16_t txtLen, const void *txtRecord ); /* TXTRecordGetItemAtIndex() * * Allows you to retrieve a key name and value pointer, given an index into * a TXT Record. Legal index values range from zero to TXTRecordGetCount()-1. * It's also possible to iterate through keys in a TXT record by simply * calling TXTRecordGetItemAtIndex() repeatedly, beginning with index zero * and increasing until TXTRecordGetItemAtIndex() returns kDNSServiceErr_Invalid. * * On return: * For keys with no value, *value is set to NULL and *valueLen is zero. * For keys with empty value, *value is non-NULL and *valueLen is zero. * For keys with non-empty value, *value is non-NULL and *valueLen is non-zero. * * txtLen: The size of the received TXT Record. * * txtRecord: Pointer to the received TXT Record bytes. * * itemIndex: An index into the TXT Record. * * keyBufLen: The size of the string buffer being supplied. * * key: A string buffer used to store the key name. * On return, the buffer contains a null-terminated C-string * giving the key name. DNS-SD TXT keys are usually * 9 characters or fewer. To hold the maximum possible * key name, the buffer should be 256 bytes long. * * valueLen: On output, will be set to the size of the "value" data. * * value: On output, *value is set to point to location within TXT * Record bytes that holds the value data. * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_NoMemory if keyBufLen is too short. * Returns kDNSServiceErr_Invalid if index is greater than * TXTRecordGetCount()-1. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex ( uint16_t txtLen, const void *txtRecord, uint16_t itemIndex, uint16_t keyBufLen, char *key, uint8_t *valueLen, const void **value ); #if _DNS_SD_LIBDISPATCH /* * DNSServiceSetDispatchQueue * * Allows you to schedule a DNSServiceRef on a serial dispatch queue for receiving asynchronous * callbacks. It's the clients responsibility to ensure that the provided dispatch queue is running. * * A typical application that uses CFRunLoopRun or dispatch_main on its main thread will * usually schedule DNSServiceRefs on its main queue (which is always a serial queue) * using "DNSServiceSetDispatchQueue(sdref, dispatch_get_main_queue());" * * If there is any error during the processing of events, the application callback will * be called with an error code. For shared connections, each subordinate DNSServiceRef * will get its own error callback. Currently these error callbacks only happen * if the daemon is manually terminated or crashes, and the error * code in this case is kDNSServiceErr_ServiceNotRunning. The application must call * DNSServiceRefDeallocate to free the DNSServiceRef when it gets such an error code. * These error callbacks are rare and should not normally happen on customer machines, * but application code should be written defensively to handle such error callbacks * gracefully if they occur. * * After using DNSServiceSetDispatchQueue on a DNSServiceRef, calling DNSServiceProcessResult * on the same DNSServiceRef will result in undefined behavior and should be avoided. * * Once the application successfully schedules a DNSServiceRef on a serial dispatch queue using * DNSServiceSetDispatchQueue, it cannot remove the DNSServiceRef from the dispatch queue, or use * DNSServiceSetDispatchQueue a second time to schedule the DNSServiceRef onto a different serial dispatch * queue. Once scheduled onto a dispatch queue a DNSServiceRef will deliver events to that queue until * the application no longer requires that operation and terminates it using DNSServiceRefDeallocate. * Note that the call to DNSServiceRefDeallocate() must be done on the same queue originally passed * as an argument to DNSServiceSetDispatchQueue(). * * service: DNSServiceRef that was allocated and returned to the application, when the * application calls one of the DNSService API. * * queue: dispatch queue where the application callback will be scheduled * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_NoMemory if it cannot create a dispatch source * Returns kDNSServiceErr_BadParam if the service param is invalid or the * queue param is invalid */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue ( DNSServiceRef service, dispatch_queue_t queue ); #endif //_DNS_SD_LIBDISPATCH #if !defined(_WIN32) typedef void (DNSSD_API *DNSServiceSleepKeepaliveReply) ( DNSServiceRef sdRef, DNSServiceErrorType errorCode, void *context ); DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive ( DNSServiceRef *sdRef, DNSServiceFlags flags, int fd, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void *context ); #endif /* Some C compiler cleverness. We can make the compiler check certain things for us, * and report errors at compile-time if anything is wrong. The usual way to do this would * be to use a run-time "if" statement or the conventional run-time "assert" mechanism, but * then you don't find out what's wrong until you run the software. This way, if the assertion * condition is false, the array size is negative, and the complier complains immediately. */ struct CompileTimeAssertionChecks_DNS_SD { char assert0[(sizeof(union _TXTRecordRef_t) == 16) ? 1 : -1]; }; #ifdef __cplusplus } #endif #endif /* _DNS_SD_H */ /* * Copyright (c) 2016-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef _DNS_SD_INTERNAL_H #define _DNS_SD_INTERNAL_H // The mDNSResponder daemon doesn't call the private DNS-SD API. #if !defined(DNS_SD_EXCLUDE_PRIVATE_API) #define DNS_SD_EXCLUDE_PRIVATE_API 1 #endif #include "dns_sd_private.h" #endif // _DNS_SD_INTERNAL_H /* * Copyright (c) 2015-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef _DNS_SD_PRIVATE_H #define _DNS_SD_PRIVATE_H #include #if !defined(DNS_SD_EXCLUDE_PRIVATE_API) #if defined(__APPLE__) #define DNS_SD_EXCLUDE_PRIVATE_API 0 #else #define DNS_SD_EXCLUDE_PRIVATE_API 1 #endif #endif // Private flags (kDNSServiceFlagsPrivateOne, kDNSServiceFlagsPrivateTwo, kDNSServiceFlagsPrivateThree, kDNSServiceFlagsPrivateFour, kDNSServiceFlagsPrivateFive) from dns_sd.h enum { kDNSServiceFlagsDenyConstrained = 0x2000, /* * This flag is meaningful only for Unicast DNS queries. When set, the daemon will restrict * DNS resolutions on interfaces defined as constrained for that request. */ kDNSServiceFlagsDenyCellular = 0x8000000, /* * This flag is meaningful only for Unicast DNS queries. When set, the daemon will restrict * DNS resolutions on the cellular interface for that request. */ kDNSServiceFlagsServiceIndex = 0x10000000, /* * This flag is meaningful only for DNSServiceGetAddrInfo() for Unicast DNS queries. * When set, DNSServiceGetAddrInfo() will interpret the "interfaceIndex" argument of the call * as the "serviceIndex". */ kDNSServiceFlagsDenyExpensive = 0x20000000, /* * This flag is meaningful only for Unicast DNS queries. When set, the daemon will restrict * DNS resolutions on interfaces defined as expensive for that request. */ kDNSServiceFlagsPathEvaluationDone = 0x40000000 /* * This flag is meaningful for only Unicast DNS queries. * When set, it indicates that Network PathEvaluation has already been performed. */ }; #if !DNS_SD_EXCLUDE_PRIVATE_API /* DNSServiceCreateDelegateConnection() * * Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. Deallocating * the reference (via DNSServiceRefDeallocate()) severs the * connection and deregisters all records registered on this connection. * * pid : Process ID of the delegate * * uuid: UUID of the delegate * * Note that only one of the two arguments (pid or uuid) can be specified. If pid * is zero, uuid will be assumed to be a valid value; otherwise pid will be used. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns * an error code indicating the specific failure that occurred (in which * case the DNSServiceRef is not initialized). kDNSServiceErr_NotAuth is * returned to indicate that the calling process does not have entitlements * to use this API. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceCreateDelegateConnection(DNSServiceRef *sdRef, int32_t pid, uuid_t uuid); // Map the source port of the local UDP socket that was opened for sending the DNS query // to the process ID of the application that triggered the DNS resolution. // /* DNSServiceGetPID() Parameters: * * srcport: Source port (in network byte order) of the UDP socket that was created by * the daemon to send the DNS query on the wire. * * pid: Process ID of the application that started the name resolution which triggered * the daemon to send the query on the wire. The value can be -1 if the srcport * cannot be mapped. * * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning * if the daemon is not running. The value of the pid is undefined if the return * value has error. */ DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceGetPID ( uint16_t srcport, int32_t *pid ); DNSSD_EXPORT DNSServiceErrorType DNSSD_API DNSServiceSetDefaultDomainForUser(DNSServiceFlags flags, const char *domain); SPI_AVAILABLE(macos(10.15.4), ios(13.2.2), watchos(6.2), tvos(13.2)) DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive_sockaddr ( DNSServiceRef * sdRef, DNSServiceFlags flags, const struct sockaddr * localAddr, const struct sockaddr * remoteAddr, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void * context ); /*! * @brief * Sets the default DNS resolver settings for the caller's process. * * @param plist_data_ptr * Pointer to an nw_resolver_config's binary property list data. * * @param plist_data_len * Byte-length of the binary property list data. Ignored if plist_data_ptr is NULL. * * @param require_encryption * Pass true if the process requires that DNS queries use an encrypted DNS service, such as DNS over HTTPS. * * @result * This function returns kDNSServiceErr_NoError on success, kDNSServiceErr_Invalid if plist_data_len * exceeds 32,768, and kDNSServiceErr_NoMemory if it fails to allocate memory. * * @discussion * These settings only apply to the calling process's DNSServiceGetAddrInfo and DNSServiceQueryRecord * requests. This function exists for code that may still use the legacy DNS-SD API for resolving * hostnames, i.e., it implements the functionality of dnssd_getaddrinfo_set_need_encrypted_query(), but at * a process-wide level of granularity. * * Due to underlying IPC limitations, there's currently a 32 KB limit on the size of the binary property * list data. */ SPI_AVAILABLE(macos(10.16), ios(14.0), watchos(7.0), tvos(14.0)) DNSServiceErrorType DNSSD_API DNSServiceSetResolverDefaults(const void *plist_data_ptr, size_t plist_data_len, bool require_encryption); #endif // !DNS_SD_EXCLUDE_PRIVATE_API #define kDNSServiceCompPrivateDNS "PrivateDNS" #define kDNSServiceCompMulticastDNS "MulticastDNS" #endif // _DNS_SD_PRIVATE_H /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2004-2018 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of Apple Inc. ("Apple") nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include "dns_sd.h" #if defined(_WIN32) // disable warning "conversion from to uint16_t" #pragma warning(disable:4244) #define strncasecmp _strnicmp #define strcasecmp _stricmp #endif /********************************************************************************************* * * Supporting Functions * *********************************************************************************************/ #define mDNSIsDigit(X) ((X) >= '0' && (X) <= '9') // DomainEndsInDot returns 1 if name ends with a dot, 0 otherwise // (DNSServiceConstructFullName depends this returning 1 for true, rather than any non-zero value meaning true) static int DomainEndsInDot(const char *dom) { while (dom[0] && dom[1]) { if (dom[0] == '\\') // advance past escaped byte sequence { if (mDNSIsDigit(dom[1]) && mDNSIsDigit(dom[2]) && mDNSIsDigit(dom[3])) dom += 4; // If "\ddd" then skip four else dom += 2; // else if "\x" then skip two } else dom++; // else goto next character } return (dom[0] == '.'); } static uint8_t *InternalTXTRecordSearch ( uint16_t txtLen, const void *txtRecord, const char *key, unsigned long *keylen ) { uint8_t *p = (uint8_t*)txtRecord; uint8_t *e = p + txtLen; *keylen = (unsigned long) strlen(key); while (p= lim) goto fail; *fn++ = '\\'; *fn++ = '0' + (c / 100); *fn++ = '0' + (c / 10) % 10; c = '0' + (c ) % 10; } else if (c == '.' || (c == '\\')) // Escape dot and backslash literals { if (fn+2 >= lim) goto fail; *fn++ = '\\'; } else if (fn+1 >= lim) goto fail; *fn++ = (char)c; } *fn++ = '.'; } while (*r) if (fn+1 >= lim) goto fail;else *fn++ = *r++; if (!DomainEndsInDot(regtype)) { if (fn+1 >= lim) goto fail;else *fn++ = '.';} while (*d) if (fn+1 >= lim) goto fail;else *fn++ = *d++; if (!DomainEndsInDot(domain)) { if (fn+1 >= lim) goto fail;else *fn++ = '.';} *fn = '\0'; return kDNSServiceErr_NoError; fail: *fn = '\0'; return kDNSServiceErr_BadParam; } /********************************************************************************************* * * TXT Record Construction Functions * *********************************************************************************************/ typedef struct _TXTRecordRefRealType { uint8_t *buffer; // Pointer to data uint16_t buflen; // Length of buffer uint16_t datalen; // Length currently in use uint16_t malloced; // Non-zero if buffer was allocated via malloc() } TXTRecordRefRealType; #define txtRec ((TXTRecordRefRealType*)txtRecord) // The opaque storage defined in the public dns_sd.h header is 16 bytes; // make sure we don't exceed that. struct CompileTimeAssertionCheck_dnssd_clientlib { char assert0[(sizeof(TXTRecordRefRealType) <= 16) ? 1 : -1]; }; void DNSSD_API TXTRecordCreate ( TXTRecordRef *txtRecord, uint16_t bufferLen, void *buffer ) { txtRec->buffer = buffer; txtRec->buflen = buffer ? bufferLen : (uint16_t)0; txtRec->datalen = 0; txtRec->malloced = 0; } void DNSSD_API TXTRecordDeallocate(TXTRecordRef *txtRecord) { if (txtRec->malloced) free(txtRec->buffer); } DNSServiceErrorType DNSSD_API TXTRecordSetValue ( TXTRecordRef *txtRecord, const char *key, uint8_t valueSize, const void *value ) { uint8_t *start, *p; const char *k; unsigned long keysize, keyvalsize; for (k = key; *k; k++) if (*k < 0x20 || *k > 0x7E || *k == '=') return(kDNSServiceErr_Invalid); keysize = (unsigned long)(k - key); keyvalsize = 1 + keysize + (value ? (1 + valueSize) : 0); if (keysize < 1 || keyvalsize > 255) return(kDNSServiceErr_Invalid); (void)TXTRecordRemoveValue(txtRecord, key); if (txtRec->datalen + keyvalsize > txtRec->buflen) { unsigned char *newbuf; unsigned long newlen = txtRec->datalen + keyvalsize; if (newlen > 0xFFFF) return(kDNSServiceErr_Invalid); newbuf = malloc((size_t)newlen); if (!newbuf) return(kDNSServiceErr_NoMemory); memcpy(newbuf, txtRec->buffer, txtRec->datalen); if (txtRec->malloced) free(txtRec->buffer); txtRec->buffer = newbuf; txtRec->buflen = (uint16_t)(newlen); txtRec->malloced = 1; } start = txtRec->buffer + txtRec->datalen; p = start + 1; memcpy(p, key, keysize); p += keysize; if (value) { *p++ = '='; memcpy(p, value, valueSize); p += valueSize; } *start = (uint8_t)(p - start - 1); txtRec->datalen += p - start; return(kDNSServiceErr_NoError); } DNSServiceErrorType DNSSD_API TXTRecordRemoveValue ( TXTRecordRef *txtRecord, const char *key ) { unsigned long keylen, itemlen, remainder; uint8_t *item = InternalTXTRecordSearch(txtRec->datalen, txtRec->buffer, key, &keylen); if (!item) return(kDNSServiceErr_NoSuchKey); itemlen = (unsigned long)(1 + item[0]); remainder = (unsigned long)((txtRec->buffer + txtRec->datalen) - (item + itemlen)); // Use memmove because memcpy behaviour is undefined for overlapping regions memmove(item, item + itemlen, remainder); txtRec->datalen -= itemlen; return(kDNSServiceErr_NoError); } uint16_t DNSSD_API TXTRecordGetLength (const TXTRecordRef *txtRecord) { return(txtRec->datalen); } const void * DNSSD_API TXTRecordGetBytesPtr(const TXTRecordRef *txtRecord) { return(txtRec->buffer); } /********************************************************************************************* * * TXT Record Parsing Functions * *********************************************************************************************/ int DNSSD_API TXTRecordContainsKey ( uint16_t txtLen, const void *txtRecord, const char *key ) { unsigned long keylen; return (InternalTXTRecordSearch(txtLen, txtRecord, key, &keylen) ? 1 : 0); } const void * DNSSD_API TXTRecordGetValuePtr ( uint16_t txtLen, const void *txtRecord, const char *key, uint8_t *valueLen ) { unsigned long keylen; uint8_t *item = InternalTXTRecordSearch(txtLen, txtRecord, key, &keylen); if (!item || item[0] <= keylen) return(NULL); // If key not found, or found with no value, return NULL *valueLen = (uint8_t)(item[0] - (keylen + 1)); return (item + 1 + keylen + 1); } uint16_t DNSSD_API TXTRecordGetCount ( uint16_t txtLen, const void *txtRecord ) { uint16_t count = 0; uint8_t *p = (uint8_t*)txtRecord; uint8_t *e = p + txtLen; while (pe) ? (uint16_t)0 : count); } DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex ( uint16_t txtLen, const void *txtRecord, uint16_t itemIndex, uint16_t keyBufLen, char *key, uint8_t *valueLen, const void **value ) { uint16_t count = 0; uint8_t *p = (uint8_t*)txtRecord; uint8_t *e = p + txtLen; while (p= keyBufLen) return(kDNSServiceErr_NoMemory); memcpy(key, x, len); key[len] = 0; if (x+len #include #include #include "dnssd_ipc.h" #if APPLE_OSX_mDNSResponder #include #include #include #include "dns_sd_private.h" #include "dnssd_clientstub_apple.h" #include #if !defined(__i386__) #define CHECK_BUNDLE_VERSION 1 #else #define CHECK_BUNDLE_VERSION 0 #endif #endif #if defined(_WIN32) #define _SSIZE_T #include #include #include #include #include #include #include #define sockaddr_mdns sockaddr_in #define AF_MDNS AF_INET // Disable warning: "'type cast' : from data pointer 'void *' to function pointer" #pragma warning(disable:4055) // Disable warning: "nonstandard extension, function/data pointer conversion in expression" #pragma warning(disable:4152) extern BOOL IsSystemServiceDisabled(); #define sleep(X) Sleep((X) * 1000) static int g_initWinsock = 0; #define LOG_WARNING kDebugLevelWarning #define LOG_INFO kDebugLevelInfo static void syslog( int priority, const char * message, ...) { va_list args; int len; char * buffer; DWORD err = WSAGetLastError(); (void) priority; va_start( args, message ); len = _vscprintf( message, args ) + 1; buffer = malloc( len * sizeof(char) ); if ( buffer ) { vsnprintf( buffer, len, message, args ); OutputDebugString( buffer ); free( buffer ); } WSASetLastError( err ); } #else #include // For O_RDWR etc. #include #include #include #define sockaddr_mdns sockaddr_un #define AF_MDNS AF_LOCAL #endif #if CHECK_BUNDLE_VERSION #include "bundle_utilities.h" #include #endif #if defined(_WIN32) // Specifies how many times we'll try and connect to the server. #define DNSSD_CLIENT_MAXTRIES 4 #endif // _WIN32 // Uncomment the line below to use the old error return mechanism of creating a temporary named socket (e.g. in /var/tmp) //#define USE_NAMED_ERROR_RETURN_SOCKET 1 // If the UDS client has not received a response from the daemon in 60 secs, it is unlikely to get one // Note: Timeout of 3 secs should be sufficient in normal scenarios, but 60 secs is chosen as a safeguard since // some clients may come up before mDNSResponder itself after a BOOT and on rare ocassions IOPM/Keychain/D2D calls // in mDNSResponder's INIT may take a much longer time to return #define DNSSD_CLIENT_TIMEOUT 60 #ifndef CTL_PATH_PREFIX #define CTL_PATH_PREFIX "/var/tmp/dnssd_result_socket." #endif typedef struct { ipc_msg_hdr ipc_hdr; DNSServiceFlags cb_flags; uint32_t cb_interface; DNSServiceErrorType cb_err; } CallbackHeader; typedef struct _DNSServiceRef_t DNSServiceOp; typedef struct _DNSRecordRef_t DNSRecord; #if !defined(_WIN32) typedef struct { void *AppCallback; // Client callback function and context void *AppContext; } SleepKAContext; #endif // client stub callback to process message from server and deliver results to client application typedef void (*ProcessReplyFn)(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *msg, const char *const end); #define ValidatorBits 0x12345678 #define DNSServiceRefValid(X) (dnssd_SocketValid((X)->sockfd) && (((X)->sockfd ^ (X)->validator) == ValidatorBits)) // When using kDNSServiceFlagsShareConnection, there is one primary _DNSServiceOp_t, and zero or more subordinates // For the primary, the 'next' field points to the first subordinate, and its 'next' field points to the next, and so on. // For the primary, the 'primary' field is NULL; for subordinates the 'primary' field points back to the associated primary // // _DNS_SD_LIBDISPATCH is defined where libdispatch/GCD is available. This does not mean that the application will use the // DNSServiceSetDispatchQueue API. Hence any new code guarded with _DNS_SD_LIBDISPATCH should still be backwards compatible. struct _DNSServiceRef_t { DNSServiceOp *next; // For shared connection DNSServiceOp *primary; // For shared connection dnssd_sock_t sockfd; // Connected socket between client and daemon dnssd_sock_t validator; // Used to detect memory corruption, double disposals, etc. client_context_t uid; // For shared connection requests, each subordinate DNSServiceRef has its own ID, // unique within the scope of the same shared parent DNSServiceRef uint32_t op; // request_op_t or reply_op_t uint32_t max_index; // Largest assigned record index - 0 if no additional records registered uint32_t logcounter; // Counter used to control number of syslog messages we write int *moreptr; // Set while DNSServiceProcessResult working on this particular DNSServiceRef ProcessReplyFn ProcessReply; // Function pointer to the code to handle received messages void *AppCallback; // Client callback function and context void *AppContext; DNSRecord *rec; #if _DNS_SD_LIBDISPATCH dispatch_source_t disp_source; dispatch_queue_t disp_queue; #endif void *kacontext; }; struct _DNSRecordRef_t { DNSRecord *recnext; void *AppContext; DNSServiceRegisterRecordReply AppCallback; DNSRecordRef recref; uint32_t record_index; // index is unique to the ServiceDiscoveryRef client_context_t uid; // For demultiplexing multiple DNSServiceRegisterRecord calls DNSServiceOp *sdr; }; #if CHECK_BUNDLE_VERSION static bool _should_return_noauth_error(void) { static dispatch_once_t s_once = 0; static bool s_should = false; dispatch_once(&s_once, ^{ s_should = bundle_sdk_is_ios14_or_later(); }); return s_should; } #endif #if !defined(USE_TCP_LOOPBACK) static void SetUDSPath(struct sockaddr_un *saddr, const char *path) { size_t pathLen; pathLen = strlen(path); if (pathLen < sizeof(saddr->sun_path)) memcpy(saddr->sun_path, path, pathLen + 1); else saddr->sun_path[0] = '\0'; } #endif enum { write_all_success = 0, write_all_fail = -1, write_all_defunct = -2 }; // Write len bytes. Return 0 on success, -1 on error static int write_all(dnssd_sock_t sd, char *buf, size_t len) { // Don't use "MSG_WAITALL"; it returns "Invalid argument" on some Linux versions; use an explicit while() loop instead. //if (send(sd, buf, len, MSG_WAITALL) != len) return write_all_fail; while (len) { ssize_t num_written = send(sd, buf, (long)len, 0); if (num_written < 0 || (size_t)num_written > len) { // Check whether socket has gone defunct, // otherwise, an error here indicates some OS bug // or that the mDNSResponder daemon crashed (which should never happen). #if !defined(__ppc__) && defined(SO_ISDEFUNCT) int defunct = 0; socklen_t dlen = sizeof (defunct); if (getsockopt(sd, SOL_SOCKET, SO_ISDEFUNCT, &defunct, &dlen) < 0) syslog(LOG_WARNING, "dnssd_clientstub write_all: SO_ISDEFUNCT failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); if (!defunct) syslog(LOG_WARNING, "dnssd_clientstub write_all(%d) failed %ld/%ld %d %s", sd, (long)num_written, (long)len, (num_written < 0) ? dnssd_errno : 0, (num_written < 0) ? dnssd_strerror(dnssd_errno) : ""); else syslog(LOG_INFO, "dnssd_clientstub write_all(%d) DEFUNCT", sd); return defunct ? write_all_defunct : write_all_fail; #else syslog(LOG_WARNING, "dnssd_clientstub write_all(%d) failed %ld/%ld %d %s", sd, (long)num_written, (long)len, (num_written < 0) ? dnssd_errno : 0, (num_written < 0) ? dnssd_strerror(dnssd_errno) : ""); return write_all_fail; #endif } buf += num_written; len -= num_written; } return write_all_success; } enum { read_all_success = 0, read_all_fail = -1, read_all_wouldblock = -2, read_all_defunct = -3 }; // Read len bytes. Return 0 on success, read_all_fail on error, or read_all_wouldblock for static int read_all(dnssd_sock_t sd, char *buf, int len) { // Don't use "MSG_WAITALL"; it returns "Invalid argument" on some Linux versions; use an explicit while() loop instead. //if (recv(sd, buf, len, MSG_WAITALL) != len) return -1; while (len) { ssize_t num_read = recv(sd, buf, len, 0); // It is valid to get an interrupted system call error e.g., somebody attaching // in a debugger, retry without failing if ((num_read < 0) && (errno == EINTR)) { syslog(LOG_INFO, "dnssd_clientstub read_all: EINTR continue"); continue; } if ((num_read == 0) || (num_read < 0) || (num_read > len)) { int printWarn = 0; int defunct = 0; // Check whether socket has gone defunct, // otherwise, an error here indicates some OS bug // or that the mDNSResponder daemon crashed (which should never happen). #if defined(WIN32) // Suppress logs for "A non-blocking socket operation // could not be completed immediately" if (WSAGetLastError() != WSAEWOULDBLOCK) printWarn = 1; #endif #if !defined(__ppc__) && defined(SO_ISDEFUNCT) { socklen_t dlen = sizeof (defunct); if (getsockopt(sd, SOL_SOCKET, SO_ISDEFUNCT, &defunct, &dlen) < 0) syslog(LOG_WARNING, "dnssd_clientstub read_all: SO_ISDEFUNCT failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); } if (!defunct) printWarn = 1; #endif if (printWarn) syslog(LOG_WARNING, "dnssd_clientstub read_all(%d) failed %ld/%ld %d %s", sd, (long)num_read, (long)len, (num_read < 0) ? dnssd_errno : 0, (num_read < 0) ? dnssd_strerror(dnssd_errno) : ""); else if (defunct) syslog(LOG_INFO, "dnssd_clientstub read_all(%d) DEFUNCT", sd); return (num_read < 0 && dnssd_errno == dnssd_EWOULDBLOCK) ? read_all_wouldblock : (defunct ? read_all_defunct : read_all_fail); } buf += num_read; len -= num_read; } return read_all_success; } // Returns 1 if more bytes remain to be read on socket descriptor sd, 0 otherwise static int more_bytes(dnssd_sock_t sd) { struct timeval tv = { 0, 0 }; fd_set readfds; fd_set *fs; int ret; #if defined(_WIN32) fs = &readfds; FD_ZERO(fs); FD_SET(sd, fs); ret = select((int)sd+1, fs, (fd_set*)NULL, (fd_set*)NULL, &tv); #else // This whole thing would probably be better done using kevent() instead of select() if (sd < FD_SETSIZE) { fs = &readfds; FD_ZERO(fs); } else { // Compute the number of integers needed for storing "sd". Internally fd_set is stored // as an array of ints with one bit for each fd and hence we need to compute // the number of ints needed rather than the number of bytes. If "sd" is 32, we need // two ints and not just one. int nfdbits = sizeof (int) * 8; int nints = (sd/nfdbits) + 1; fs = (fd_set *)calloc(nints, (size_t)sizeof(int)); if (fs == NULL) { syslog(LOG_WARNING, "dnssd_clientstub more_bytes: malloc failed"); return 0; } } FD_SET(sd, fs); ret = select((int)sd+1, fs, (fd_set*)NULL, (fd_set*)NULL, &tv); if (fs != &readfds) free(fs); #endif return (ret > 0); } // set_waitlimit() implements a timeout using select. It is called from deliver_request() before recv() OR accept() // to ensure the UDS clients are not blocked in these system calls indefinitely. // Note: Ideally one should never be blocked here, because it indicates either mDNSResponder daemon is not yet up/hung/ // superbusy/crashed or some other OS bug. For eg: On Windows which suffers from 3rd party software // (primarily 3rd party firewall software) interfering with proper functioning of the TCP protocol stack it is possible // the next operation on this socket(recv/accept) is blocked since we depend on TCP to communicate with the system service. static int set_waitlimit(dnssd_sock_t sock, int timeout) { int gDaemonErr = kDNSServiceErr_NoError; // The comment below is wrong. The select() routine does not cause stack corruption. // The use of FD_SET out of range for the bitmap is what causes stack corruption. // For how to do this correctly, see the example using calloc() in more_bytes() above. // Even better, both should be changed to use kevent() instead of select(). // To prevent stack corruption since select does not work with timeout if fds > FD_SETSIZE(1024) if (!gDaemonErr && sock < FD_SETSIZE) { struct timeval tv; fd_set set; FD_ZERO(&set); FD_SET(sock, &set); tv.tv_sec = timeout; tv.tv_usec = 0; if (!select((int)(sock + 1), &set, NULL, NULL, &tv)) { // Ideally one should never hit this case: See comments before set_waitlimit() syslog(LOG_WARNING, "dnssd_clientstub set_waitlimit:_daemon timed out (%d secs) without any response: Socket %d", timeout, sock); gDaemonErr = kDNSServiceErr_Timeout; } } return gDaemonErr; } /* create_hdr * * allocate and initialize an ipc message header. Value of len should initially be the * length of the data, and is set to the value of the data plus the header. data_start * is set to point to the beginning of the data section. SeparateReturnSocket should be * non-zero for calls that can't receive an immediate error return value on their primary * socket, and therefore require a separate return path for the error code result. * if zero, the path to a control socket is appended at the beginning of the message buffer. * data_start is set past this string. */ static ipc_msg_hdr *create_hdr(uint32_t op, size_t *len, char **data_start, int SeparateReturnSocket, DNSServiceOp *ref) { char *msg = NULL; ipc_msg_hdr *hdr; int datalen; #if !defined(USE_TCP_LOOPBACK) char ctrl_path[64] = ""; // "/var/tmp/dnssd_result_socket.xxxxxxxxxx-xxx-xxxxxx" #endif if (SeparateReturnSocket) { #if defined(USE_TCP_LOOPBACK) *len += 2; // Allocate space for two-byte port number #elif defined(USE_NAMED_ERROR_RETURN_SOCKET) struct timeval tv; if (gettimeofday(&tv, NULL) < 0) { syslog(LOG_WARNING, "dnssd_clientstub create_hdr: gettimeofday failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); return NULL; } snprintf(ctrl_path, sizeof(ctrl_path), "%s%d-%.3lx-%.6lu", CTL_PATH_PREFIX, (int)getpid(), (unsigned long)(tv.tv_sec & 0xFFF), (unsigned long)(tv.tv_usec)); *len += strlen(ctrl_path) + 1; #else *len += 1; // Allocate space for single zero byte (empty C string) #endif } datalen = (int) *len; *len += sizeof(ipc_msg_hdr); // Write message to buffer msg = malloc(*len); if (!msg) { syslog(LOG_WARNING, "dnssd_clientstub create_hdr: malloc failed"); return NULL; } memset(msg, 0, *len); hdr = (ipc_msg_hdr *)msg; hdr->version = VERSION; hdr->datalen = datalen; hdr->ipc_flags = 0; hdr->op = op; hdr->client_context = ref->uid; hdr->reg_index = 0; *data_start = msg + sizeof(ipc_msg_hdr); #if defined(USE_TCP_LOOPBACK) // Put dummy data in for the port, since we don't know what it is yet. // The data will get filled in before we send the message. This happens in deliver_request(). if (SeparateReturnSocket) put_uint16(0, data_start); #else if (SeparateReturnSocket) put_string(ctrl_path, data_start); #endif return hdr; } static void FreeDNSRecords(DNSServiceOp *sdRef) { DNSRecord *rec = sdRef->rec; while (rec) { DNSRecord *next = rec->recnext; free(rec); rec = next; } } static void FreeDNSServiceOp(DNSServiceOp *x) { // We don't use our DNSServiceRefValid macro here because if we're cleaning up after a socket() call failed // then sockfd could legitimately contain a failing value (e.g. dnssd_InvalidSocket) if ((x->sockfd ^ x->validator) != ValidatorBits) { } else { x->next = NULL; x->primary = NULL; x->sockfd = dnssd_InvalidSocket; x->validator = 0xDDDDDDDD; x->op = request_op_none; x->max_index = 0; x->logcounter = 0; x->moreptr = NULL; x->ProcessReply = NULL; x->AppCallback = NULL; x->AppContext = NULL; #if _DNS_SD_LIBDISPATCH if (x->disp_source) dispatch_release(x->disp_source); x->disp_source = NULL; x->disp_queue = NULL; #endif // DNSRecords may have been added to subordinate sdRef e.g., DNSServiceRegister/DNSServiceAddRecord // or on the main sdRef e.g., DNSServiceCreateConnection/DNSServiceRegisterRecord. // DNSRecords may have been freed if the application called DNSRemoveRecord. FreeDNSRecords(x); if (x->kacontext) { free(x->kacontext); x->kacontext = NULL; } free(x); } } // Return a connected service ref (deallocate with DNSServiceRefDeallocate) static DNSServiceErrorType ConnectToServer(DNSServiceRef *ref, DNSServiceFlags flags, uint32_t op, ProcessReplyFn ProcessReply, void *AppCallback, void *AppContext) { #if defined(_WIN32) int NumTries = 0; #endif // _WIN32 dnssd_sockaddr_t saddr; DNSServiceOp *sdr; if (!ref) { syslog(LOG_WARNING, "dnssd_clientstub DNSService operation with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; } if (flags & kDNSServiceFlagsShareConnection) { if (!*ref) { syslog(LOG_WARNING, "dnssd_clientstub kDNSServiceFlagsShareConnection used with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; } if (!DNSServiceRefValid(*ref) || ((*ref)->op != connection_request && (*ref)->op != connection_delegate_request) || (*ref)->primary) { syslog(LOG_WARNING, "dnssd_clientstub kDNSServiceFlagsShareConnection used with invalid DNSServiceRef %p %08X %08X op %d", (*ref), (*ref)->sockfd, (*ref)->validator, (*ref)->op); *ref = NULL; return kDNSServiceErr_BadReference; } } #if defined(_WIN32) if (!g_initWinsock) { WSADATA wsaData; g_initWinsock = 1; if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0) { *ref = NULL; return kDNSServiceErr_ServiceNotRunning; } } // If the system service is disabled, we only want to try to connect once if (IsSystemServiceDisabled()) NumTries = DNSSD_CLIENT_MAXTRIES; #endif sdr = malloc(sizeof(DNSServiceOp)); if (!sdr) { syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: malloc failed"); *ref = NULL; return kDNSServiceErr_NoMemory; } sdr->next = NULL; sdr->primary = NULL; sdr->sockfd = dnssd_InvalidSocket; sdr->validator = sdr->sockfd ^ ValidatorBits; sdr->op = op; sdr->max_index = 0; sdr->logcounter = 0; sdr->moreptr = NULL; sdr->uid.u32[0] = 0; sdr->uid.u32[1] = 0; sdr->ProcessReply = ProcessReply; sdr->AppCallback = AppCallback; sdr->AppContext = AppContext; sdr->rec = NULL; #if _DNS_SD_LIBDISPATCH sdr->disp_source = NULL; sdr->disp_queue = NULL; #endif sdr->kacontext = NULL; if (flags & kDNSServiceFlagsShareConnection) { DNSServiceOp **p = &(*ref)->next; // Append ourselves to end of primary's list while (*p) p = &(*p)->next; *p = sdr; // Preincrement counter before we use it -- it helps with debugging if we know the all-zeroes ID should never appear if (++(*ref)->uid.u32[0] == 0) ++(*ref)->uid.u32[1]; // In parent DNSServiceOp increment UID counter sdr->primary = *ref; // Set our primary pointer sdr->sockfd = (*ref)->sockfd; // Inherit primary's socket sdr->validator = (*ref)->validator; sdr->uid = (*ref)->uid; //printf("ConnectToServer sharing socket %d\n", sdr->sockfd); } else { #ifdef SO_NOSIGPIPE const unsigned long optval = 1; #endif #ifndef USE_TCP_LOOPBACK char* uds_serverpath = getenv(MDNS_UDS_SERVERPATH_ENVVAR); if (uds_serverpath == NULL) uds_serverpath = MDNS_UDS_SERVERPATH; else if (strlen(uds_serverpath) >= MAX_CTLPATH) { uds_serverpath = MDNS_UDS_SERVERPATH; syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: using default path since env len is invalid"); } #endif *ref = NULL; sdr->sockfd = socket(AF_DNSSD, SOCK_STREAM, 0); sdr->validator = sdr->sockfd ^ ValidatorBits; if (!dnssd_SocketValid(sdr->sockfd)) { syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: socket failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); FreeDNSServiceOp(sdr); return kDNSServiceErr_NoMemory; } #if !defined(_WIN32) int fcntl_flags = fcntl(sdr->sockfd, F_GETFD); if (fcntl_flags != -1) { fcntl_flags |= FD_CLOEXEC; int ret = fcntl(sdr->sockfd, F_SETFD, fcntl_flags); if (ret == -1) syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: Failed to set FD_CLOEXEC on socket %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); } else { syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: Failed to get the file descriptor flags of socket %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); } #endif // !defined(_WIN32) #ifdef SO_NOSIGPIPE // Some environments (e.g. OS X) support turning off SIGPIPE for a socket if (setsockopt(sdr->sockfd, SOL_SOCKET, SO_NOSIGPIPE, &optval, sizeof(optval)) < 0) syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: SO_NOSIGPIPE failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); #endif #if defined(USE_TCP_LOOPBACK) saddr.sin_family = AF_INET; saddr.sin_addr.s_addr = inet_addr(MDNS_TCP_SERVERADDR); saddr.sin_port = htons(MDNS_TCP_SERVERPORT); #else saddr.sun_family = AF_LOCAL; SetUDSPath(&saddr, uds_serverpath); #if !defined(__ppc__) && defined(SO_DEFUNCTOK) { int defunct = 1; if (setsockopt(sdr->sockfd, SOL_SOCKET, SO_DEFUNCTOK, &defunct, sizeof(defunct)) < 0) syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: SO_DEFUNCTOK failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); } #endif #endif #if defined(_WIN32) while (1) { int err = connect(sdr->sockfd, (struct sockaddr *) &saddr, sizeof(saddr)); if (!err) break; // If we succeeded, return sdr // If we failed, then it may be because the daemon is still launching. // This can happen for processes that launch early in the boot process, while the // daemon is still coming up. Rather than fail here, we wait 1 sec and try again. // If, after DNSSD_CLIENT_MAXTRIES, we still can't connect to the daemon, // then we give up and return a failure code. if (++NumTries < DNSSD_CLIENT_MAXTRIES) { syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: connect()-> No of tries: %d", NumTries); sleep(1); // Sleep a bit, then try again } else { #if !defined(USE_TCP_LOOPBACK) syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: connect() failed path:%s Socket:%d Err:%d Errno:%d %s", uds_serverpath, sdr->sockfd, err, dnssd_errno, dnssd_strerror(dnssd_errno)); #endif dnssd_close(sdr->sockfd); FreeDNSServiceOp(sdr); return kDNSServiceErr_ServiceNotRunning; } } #else int err = connect(sdr->sockfd, (struct sockaddr *) &saddr, sizeof(saddr)); if (err) { #if !defined(USE_TCP_LOOPBACK) syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: connect() failed path:%s Socket:%d Err:%d Errno:%d %s", uds_serverpath, sdr->sockfd, err, dnssd_errno, dnssd_strerror(dnssd_errno)); #endif dnssd_close(sdr->sockfd); FreeDNSServiceOp(sdr); return kDNSServiceErr_ServiceNotRunning; } #endif } *ref = sdr; return kDNSServiceErr_NoError; } #define deliver_request_bailout(MSG) \ syslog(LOG_WARNING, "dnssd_clientstub deliver_request: %s failed %d (%s)", (MSG), dnssd_errno, dnssd_strerror(dnssd_errno)); goto cleanup static DNSServiceErrorType deliver_request(ipc_msg_hdr *hdr, DNSServiceOp *sdr) { uint32_t datalen; dnssd_sock_t listenfd = dnssd_InvalidSocket, errsd = dnssd_InvalidSocket; DNSServiceErrorType err = kDNSServiceErr_Unknown; // Default for the "goto cleanup" cases int MakeSeparateReturnSocket; int ioresult; #if defined(USE_TCP_LOOPBACK) || defined(USE_NAMED_ERROR_RETURN_SOCKET) char *data; #endif if (!hdr) { syslog(LOG_WARNING, "dnssd_clientstub deliver_request: !hdr"); return kDNSServiceErr_Unknown; } datalen = hdr->datalen; // We take a copy here because we're going to convert hdr->datalen to network byte order #if defined(USE_TCP_LOOPBACK) || defined(USE_NAMED_ERROR_RETURN_SOCKET) data = (char *)hdr + sizeof(ipc_msg_hdr); #endif // Note: need to check hdr->op, not sdr->op. // hdr->op contains the code for the specific operation we're currently doing, whereas sdr->op // contains the original parent DNSServiceOp (e.g. for an add_record_request, hdr->op will be // add_record_request but the parent sdr->op will be connection_request or reg_service_request) MakeSeparateReturnSocket = (sdr->primary || hdr->op == reg_record_request || hdr->op == add_record_request || hdr->op == update_record_request || hdr->op == remove_record_request); if (!DNSServiceRefValid(sdr)) { if (hdr) free(hdr); syslog(LOG_WARNING, "dnssd_clientstub deliver_request: invalid DNSServiceRef %p %08X %08X", sdr, sdr->sockfd, sdr->validator); return kDNSServiceErr_BadReference; } if (MakeSeparateReturnSocket) { #if defined(USE_TCP_LOOPBACK) { union { uint16_t s; u_char b[2]; } port; dnssd_sockaddr_t caddr; dnssd_socklen_t len = (dnssd_socklen_t) sizeof(caddr); listenfd = socket(AF_DNSSD, SOCK_STREAM, 0); if (!dnssd_SocketValid(listenfd)) { deliver_request_bailout("TCP socket"); } caddr.sin_family = AF_INET; caddr.sin_port = 0; caddr.sin_addr.s_addr = inet_addr(MDNS_TCP_SERVERADDR); if (bind(listenfd, (struct sockaddr*) &caddr, sizeof(caddr)) < 0) { deliver_request_bailout("TCP bind"); } if (getsockname(listenfd, (struct sockaddr*) &caddr, &len) < 0) { deliver_request_bailout("TCP getsockname"); } if (listen(listenfd, 1) < 0) { deliver_request_bailout("TCP listen"); } port.s = caddr.sin_port; data[0] = port.b[0]; // don't switch the byte order, as the data[1] = port.b[1]; // daemon expects it in network byte order } #elif defined(USE_NAMED_ERROR_RETURN_SOCKET) { mode_t mask; int bindresult; dnssd_sockaddr_t caddr; listenfd = socket(AF_DNSSD, SOCK_STREAM, 0); if (!dnssd_SocketValid(listenfd)) { deliver_request_bailout("USE_NAMED_ERROR_RETURN_SOCKET socket"); } caddr.sun_family = AF_LOCAL; // According to Stevens (section 3.2), there is no portable way to // determine whether sa_len is defined on a particular platform. #ifndef NOT_HAVE_SA_LEN caddr.sun_len = sizeof(struct sockaddr_un); #endif SetUDSPath(&caddr, data); mask = umask(0); bindresult = bind(listenfd, (struct sockaddr *)&caddr, sizeof(caddr)); umask(mask); if (bindresult < 0) { deliver_request_bailout("USE_NAMED_ERROR_RETURN_SOCKET bind"); } if (listen(listenfd, 1) < 0) { deliver_request_bailout("USE_NAMED_ERROR_RETURN_SOCKET listen"); } } #else { dnssd_sock_t sp[2]; if (socketpair(AF_DNSSD, SOCK_STREAM, 0, sp) < 0) { deliver_request_bailout("socketpair"); } else { errsd = sp[0]; // We'll read our four-byte error code from sp[0] listenfd = sp[1]; // We'll send sp[1] to the daemon #if !defined(__ppc__) && defined(SO_DEFUNCTOK) { int defunct = 1; if (setsockopt(errsd, SOL_SOCKET, SO_DEFUNCTOK, &defunct, sizeof(defunct)) < 0) syslog(LOG_WARNING, "dnssd_clientstub deliver_request: SO_DEFUNCTOK failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); } #endif } } #endif } #if !defined(USE_TCP_LOOPBACK) && !defined(USE_NAMED_ERROR_RETURN_SOCKET) // If we're going to make a separate error return socket, and pass it to the daemon // using sendmsg, then we'll hold back one data byte to go with it. // On some versions of Unix (including Leopard) sending a control message without // any associated data does not work reliably -- e.g. one particular issue we ran // into is that if the receiving program is in a kqueue loop waiting to be notified // of the received message, it doesn't get woken up when the control message arrives. if (MakeSeparateReturnSocket || sdr->op == send_bpf) datalen--; // Okay to use sdr->op when checking for op == send_bpf #endif // At this point, our listening socket is set up and waiting, if necessary, for the daemon to connect back to ConvertHeaderBytes(hdr); //syslog(LOG_WARNING, "dnssd_clientstub deliver_request writing %lu bytes", (unsigned long)(datalen + sizeof(ipc_msg_hdr))); //if (MakeSeparateReturnSocket) syslog(LOG_WARNING, "dnssd_clientstub deliver_request name is %s", data); #if TEST_SENDING_ONE_BYTE_AT_A_TIME unsigned int i; for (i=0; isockfd, ((char *)hdr)+i, 1); if (ioresult < write_all_success) { syslog(LOG_WARNING, "dnssd_clientstub deliver_request write_all (byte %u) failed", i); err = (ioresult == write_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; goto cleanup; } usleep(10000); } #else ioresult = write_all(sdr->sockfd, (char *)hdr, datalen + sizeof(ipc_msg_hdr)); if (ioresult < write_all_success) { // write_all already prints an error message if there is an error writing to // the socket except for DEFUNCT. Logging here is unnecessary and also wrong // in the case of DEFUNCT sockets syslog(LOG_INFO, "dnssd_clientstub deliver_request ERROR: write_all(%d, %lu bytes) failed", sdr->sockfd, (unsigned long)(datalen + sizeof(ipc_msg_hdr))); err = (ioresult == write_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; goto cleanup; } #endif if (!MakeSeparateReturnSocket) errsd = sdr->sockfd; if (MakeSeparateReturnSocket || sdr->op == send_bpf) // Okay to use sdr->op when checking for op == send_bpf { #if defined(USE_TCP_LOOPBACK) || defined(USE_NAMED_ERROR_RETURN_SOCKET) // At this point we may wait in accept for a few milliseconds waiting for the daemon to connect back to us, // but that's okay -- the daemon should not take more than a few milliseconds to respond. // set_waitlimit() ensures we do not block indefinitely just in case something is wrong dnssd_sockaddr_t daddr; dnssd_socklen_t len = sizeof(daddr); if ((err = set_waitlimit(listenfd, DNSSD_CLIENT_TIMEOUT)) != kDNSServiceErr_NoError) goto cleanup; errsd = accept(listenfd, (struct sockaddr *)&daddr, &len); if (!dnssd_SocketValid(errsd)) { deliver_request_bailout("accept"); } #else struct iovec vec = { ((char *)hdr) + sizeof(ipc_msg_hdr) + datalen, 1 }; // Send the last byte along with the SCM_RIGHTS struct msghdr msg; struct cmsghdr *cmsg; char cbuf[CMSG_SPACE(4 * sizeof(dnssd_sock_t))]; msg.msg_name = 0; msg.msg_namelen = 0; msg.msg_iov = &vec; msg.msg_iovlen = 1; msg.msg_flags = 0; if (MakeSeparateReturnSocket || sdr->op == send_bpf) // Okay to use sdr->op when checking for op == send_bpf { if (sdr->op == send_bpf) { int i; char p[12]; // Room for "/dev/bpf999" with terminating null for (i=0; i<100; i++) { snprintf(p, sizeof(p), "/dev/bpf%d", i); listenfd = open(p, O_RDWR, 0); //if (dnssd_SocketValid(listenfd)) syslog(LOG_WARNING, "dnssd_clientstub deliver_request Sending fd %d for %s", listenfd, p); if (!dnssd_SocketValid(listenfd) && dnssd_errno != EBUSY) syslog(LOG_WARNING, "dnssd_clientstub deliver_request Error opening %s %d (%s)", p, dnssd_errno, dnssd_strerror(dnssd_errno)); if (dnssd_SocketValid(listenfd) || dnssd_errno != EBUSY) break; } } msg.msg_control = cbuf; msg.msg_controllen = CMSG_LEN(sizeof(dnssd_sock_t)); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_len = CMSG_LEN(sizeof(dnssd_sock_t)); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; *((dnssd_sock_t *)CMSG_DATA(cmsg)) = listenfd; } #if TEST_KQUEUE_CONTROL_MESSAGE_BUG sleep(1); #endif #if DEBUG_64BIT_SCM_RIGHTS syslog(LOG_WARNING, "dnssd_clientstub deliver_request sendmsg read sd=%d write sd=%d %ld %ld %ld/%ld/%ld/%ld", errsd, listenfd, sizeof(dnssd_sock_t), sizeof(void*), sizeof(struct cmsghdr) + sizeof(dnssd_sock_t), CMSG_LEN(sizeof(dnssd_sock_t)), (long)CMSG_SPACE(sizeof(dnssd_sock_t)), (long)((char*)CMSG_DATA(cmsg) + 4 - cbuf)); #endif // DEBUG_64BIT_SCM_RIGHTS if (sendmsg(sdr->sockfd, &msg, 0) < 0) { syslog(LOG_WARNING, "dnssd_clientstub deliver_request ERROR: sendmsg failed read sd=%d write sd=%d errno %d (%s)", errsd, listenfd, dnssd_errno, dnssd_strerror(dnssd_errno)); err = kDNSServiceErr_Incompatible; goto cleanup; } #if DEBUG_64BIT_SCM_RIGHTS syslog(LOG_WARNING, "dnssd_clientstub deliver_request sendmsg read sd=%d write sd=%d okay", errsd, listenfd); #endif // DEBUG_64BIT_SCM_RIGHTS #endif // Close our end of the socketpair *before* calling read_all() to get the four-byte error code. // Otherwise, if the daemon closes our socket (or crashes), we will have to wait for a timeout // in read_all() because the socket is not closed (we still have an open reference to it) // Note: listenfd is overwritten in the case of send_bpf above and that will be closed here // for send_bpf operation. dnssd_close(listenfd); listenfd = dnssd_InvalidSocket; // Make sure we don't close it a second time in the cleanup handling below } // At this point we may wait in read_all for a few milliseconds waiting for the daemon to send us the error code, // but that's okay -- the daemon should not take more than a few milliseconds to respond. // set_waitlimit() ensures we do not block indefinitely just in case something is wrong if (sdr->op == send_bpf) // Okay to use sdr->op when checking for op == send_bpf err = kDNSServiceErr_NoError; else if ((err = set_waitlimit(errsd, DNSSD_CLIENT_TIMEOUT)) == kDNSServiceErr_NoError) { ioresult = read_all(errsd, (char*)&err, (int)sizeof(err)); if (ioresult < read_all_success) err = (ioresult == read_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; // On failure read_all will have written a message to syslog for us else err = ntohl(err); } //syslog(LOG_WARNING, "dnssd_clientstub deliver_request: retrieved error code %d", err); cleanup: if (MakeSeparateReturnSocket) { if (dnssd_SocketValid(listenfd)) dnssd_close(listenfd); if (dnssd_SocketValid(errsd)) dnssd_close(errsd); #if defined(USE_NAMED_ERROR_RETURN_SOCKET) // syslog(LOG_WARNING, "dnssd_clientstub deliver_request: removing UDS: %s", data); if (unlink(data) != 0) syslog(LOG_WARNING, "dnssd_clientstub WARNING: unlink(\"%s\") failed errno %d (%s)", data, dnssd_errno, dnssd_strerror(dnssd_errno)); // else syslog(LOG_WARNING, "dnssd_clientstub deliver_request: removed UDS: %s", data); #endif } free(hdr); return err; } dnssd_sock_t DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef) { if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefSockFD called with NULL DNSServiceRef"); return dnssd_InvalidSocket; } if (!DNSServiceRefValid(sdRef)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefSockFD called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return dnssd_InvalidSocket; } if (sdRef->primary) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefSockFD undefined for kDNSServiceFlagsShareConnection subordinate DNSServiceRef %p", sdRef); return dnssd_InvalidSocket; } return sdRef->sockfd; } #if _DNS_SD_LIBDISPATCH static void CallbackWithError(DNSServiceRef sdRef, DNSServiceErrorType error) { DNSServiceOp *sdr = sdRef; DNSServiceOp *sdrNext; DNSRecord *rec; DNSRecord *recnext; int morebytes; while (sdr) { // We can't touch the sdr after the callback as it can be deallocated in the callback sdrNext = sdr->next; morebytes = 1; sdr->moreptr = &morebytes; switch (sdr->op) { case resolve_request: if (sdr->AppCallback) ((DNSServiceResolveReply) sdr->AppCallback)(sdr, 0, 0, error, NULL, 0, 0, 0, NULL, sdr->AppContext); break; case query_request: if (sdr->AppCallback) ((DNSServiceQueryRecordReply)sdr->AppCallback)(sdr, 0, 0, error, NULL, 0, 0, 0, NULL, 0, sdr->AppContext); break; case addrinfo_request: if (sdr->AppCallback) ((DNSServiceGetAddrInfoReply)sdr->AppCallback)(sdr, 0, 0, error, NULL, NULL, 0, sdr->AppContext); break; case browse_request: if (sdr->AppCallback) ((DNSServiceBrowseReply) sdr->AppCallback)(sdr, 0, 0, error, NULL, 0, NULL, sdr->AppContext); break; case reg_service_request: if (sdr->AppCallback) ((DNSServiceRegisterReply) sdr->AppCallback)(sdr, 0, error, NULL, 0, NULL, sdr->AppContext); break; case enumeration_request: if (sdr->AppCallback) ((DNSServiceDomainEnumReply) sdr->AppCallback)(sdr, 0, 0, error, NULL, sdr->AppContext); break; case connection_request: case connection_delegate_request: // This means Register Record, walk the list of DNSRecords to do the callback rec = sdr->rec; while (rec) { recnext = rec->recnext; if (rec->AppCallback) ((DNSServiceRegisterRecordReply)rec->AppCallback)(sdr, 0, 0, error, rec->AppContext); // The Callback can call DNSServiceRefDeallocate which in turn frees sdr and all the records. // Detect that and return early if (!morebytes) { syslog(LOG_WARNING, "dnssd_clientstub:Record: CallbackwithError morebytes zero"); return; } rec = recnext; } break; case port_mapping_request: if (sdr->AppCallback) ((DNSServiceNATPortMappingReply)sdr->AppCallback)(sdr, 0, 0, error, 0, 0, 0, 0, 0, sdr->AppContext); break; default: syslog(LOG_WARNING, "dnssd_clientstub CallbackWithError called with bad op %d", sdr->op); } // If DNSServiceRefDeallocate was called in the callback, morebytes will be zero. As the sdRef // (and its subordinates) have been freed, we should not proceed further. Note that when we // call the callback with a subordinate sdRef the application can call DNSServiceRefDeallocate // on the main sdRef and DNSServiceRefDeallocate handles this case by walking all the sdRefs and // clears the moreptr so that we can terminate here. // // If DNSServiceRefDeallocate was not called in the callback, then set moreptr to NULL so that // we don't access the stack variable after we return from this function. if (!morebytes) { syslog(LOG_WARNING, "dnssd_clientstub:sdRef: CallbackwithError morebytes zero sdr %p", sdr); return; } else {sdr->moreptr = NULL;} sdr = sdrNext; } } #endif // _DNS_SD_LIBDISPATCH // Handle reply from server, calling application client callback. If there is no reply // from the daemon on the socket contained in sdRef, the call will block. DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef) { int morebytes = 0; int ioresult; DNSServiceErrorType error; if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult called with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; } if (!DNSServiceRefValid(sdRef)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return kDNSServiceErr_BadReference; } if (sdRef->primary) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult undefined for kDNSServiceFlagsShareConnection subordinate DNSServiceRef %p", sdRef); return kDNSServiceErr_BadReference; } if (!sdRef->ProcessReply) { static int num_logs = 0; if (num_logs < 10) syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult called with DNSServiceRef with no ProcessReply function"); if (num_logs < 1000) num_logs++;else sleep(1); return kDNSServiceErr_BadReference; } do { CallbackHeader cbh; char *data; // return NoError on EWOULDBLOCK. This will handle the case // where a non-blocking socket is told there is data, but it was a false positive. // On error, read_all will write a message to syslog for us, so don't need to duplicate that here // Note: If we want to properly support using non-blocking sockets in the future ioresult = read_all(sdRef->sockfd, (void *)&cbh.ipc_hdr, sizeof(cbh.ipc_hdr)); if (ioresult == read_all_fail || ioresult == read_all_defunct) { error = (ioresult == read_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; // Set the ProcessReply to NULL before callback as the sdRef can get deallocated // in the callback. sdRef->ProcessReply = NULL; #if _DNS_SD_LIBDISPATCH // Call the callbacks with an error if using the dispatch API, as DNSServiceProcessResult // is not called by the application and hence need to communicate the error. Cancel the // source so that we don't get any more events // Note: read_all fails if we could not read from the daemon which can happen if the // daemon dies or the file descriptor is disconnected (defunct). if (sdRef->disp_source) { dispatch_source_cancel(sdRef->disp_source); dispatch_release(sdRef->disp_source); sdRef->disp_source = NULL; CallbackWithError(sdRef, error); } #endif // Don't touch sdRef anymore as it might have been deallocated return error; } else if (ioresult == read_all_wouldblock) { if (morebytes && sdRef->logcounter < 100) { sdRef->logcounter++; syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult error: select indicated data was waiting but read_all returned EWOULDBLOCK"); } return kDNSServiceErr_NoError; } ConvertHeaderBytes(&cbh.ipc_hdr); if (cbh.ipc_hdr.version != VERSION) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult daemon version %d does not match client version %d", cbh.ipc_hdr.version, VERSION); sdRef->ProcessReply = NULL; return kDNSServiceErr_Incompatible; } data = malloc(cbh.ipc_hdr.datalen); if (!data) return kDNSServiceErr_NoMemory; ioresult = read_all(sdRef->sockfd, data, cbh.ipc_hdr.datalen); if (ioresult < read_all_success) // On error, read_all will write a message to syslog for us { error = (ioresult == read_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; // Set the ProcessReply to NULL before callback as the sdRef can get deallocated // in the callback. sdRef->ProcessReply = NULL; #if _DNS_SD_LIBDISPATCH // Call the callbacks with an error if using the dispatch API, as DNSServiceProcessResult // is not called by the application and hence need to communicate the error. Cancel the // source so that we don't get any more events if (sdRef->disp_source) { dispatch_source_cancel(sdRef->disp_source); dispatch_release(sdRef->disp_source); sdRef->disp_source = NULL; CallbackWithError(sdRef, error); } #endif // Don't touch sdRef anymore as it might have been deallocated free(data); return error; } else { const char *ptr = data; cbh.cb_flags = get_flags (&ptr, data + cbh.ipc_hdr.datalen); cbh.cb_interface = get_uint32 (&ptr, data + cbh.ipc_hdr.datalen); cbh.cb_err = get_error_code(&ptr, data + cbh.ipc_hdr.datalen); // CAUTION: We have to handle the case where the client calls DNSServiceRefDeallocate from within the callback function. // To do this we set moreptr to point to morebytes. If the client does call DNSServiceRefDeallocate(), // then that routine will clear morebytes for us, and cause us to exit our loop. morebytes = more_bytes(sdRef->sockfd); if (morebytes) { cbh.cb_flags |= kDNSServiceFlagsMoreComing; sdRef->moreptr = &morebytes; } if (ptr) sdRef->ProcessReply(sdRef, &cbh, ptr, data + cbh.ipc_hdr.datalen); // Careful code here: // If morebytes is non-zero, that means we set sdRef->moreptr above, and the operation was not // cancelled out from under us, so now we need to clear sdRef->moreptr so we don't leave a stray // dangling pointer pointing to a long-gone stack variable. // If morebytes is zero, then one of two thing happened: // (a) morebytes was 0 above, so we didn't set sdRef->moreptr, so we don't need to clear it // (b) morebytes was 1 above, and we set sdRef->moreptr, but the operation was cancelled (with DNSServiceRefDeallocate()), // so we MUST NOT try to dereference our stale sdRef pointer. if (morebytes) sdRef->moreptr = NULL; } free(data); } while (morebytes); return kDNSServiceErr_NoError; } void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef) { if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefDeallocate called with NULL DNSServiceRef"); return; } if (!DNSServiceRefValid(sdRef)) // Also verifies dnssd_SocketValid(sdRef->sockfd) for us too { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return; } // If we're in the middle of a DNSServiceProcessResult() invocation for this DNSServiceRef, clear its morebytes flag to break it out of its while loop if (sdRef->moreptr) *(sdRef->moreptr) = 0; if (sdRef->primary) // If this is a subordinate DNSServiceOp, just send a 'stop' command { DNSServiceOp **p = &sdRef->primary->next; while (*p && *p != sdRef) p = &(*p)->next; if (*p) { char *ptr; size_t len = 0; ipc_msg_hdr *hdr = create_hdr(cancel_request, &len, &ptr, 0, sdRef); if (hdr) { ConvertHeaderBytes(hdr); write_all(sdRef->sockfd, (char *)hdr, len); free(hdr); } *p = sdRef->next; FreeDNSServiceOp(sdRef); } } else // else, make sure to terminate all subordinates as well { #if _DNS_SD_LIBDISPATCH // The cancel handler will close the fd if a dispatch source has been set if (sdRef->disp_source) { // By setting the ProcessReply to NULL, we make sure that we never call // the application callbacks ever, after returning from this function. We // assume that DNSServiceRefDeallocate is called from the serial queue // that was passed to DNSServiceSetDispatchQueue. Hence, dispatch_source_cancel // should cancel all the blocks on the queue and hence there should be no more // callbacks when we return from this function. Setting ProcessReply to NULL // provides extra protection. sdRef->ProcessReply = NULL; shutdown(sdRef->sockfd, SHUT_WR); dispatch_source_cancel(sdRef->disp_source); dispatch_release(sdRef->disp_source); sdRef->disp_source = NULL; } // if disp_queue is set, it means it used the DNSServiceSetDispatchQueue API. In that case, // when the source was cancelled, the fd was closed in the handler. Currently the source // is cancelled only when the mDNSResponder daemon dies else if (!sdRef->disp_queue) dnssd_close(sdRef->sockfd); #else dnssd_close(sdRef->sockfd); #endif // Free DNSRecords added in DNSRegisterRecord if they have not // been freed in DNSRemoveRecord while (sdRef) { DNSServiceOp *p = sdRef; sdRef = sdRef->next; // When there is an error reading from the daemon e.g., bad fd, CallbackWithError // is called which sets moreptr. It might set the moreptr on a subordinate sdRef // but the application might call DNSServiceRefDeallocate with the main sdRef from // the callback. Hence, when we loop through the subordinate sdRefs, we need // to clear the moreptr so that CallbackWithError can terminate itself instead of // walking through the freed sdRefs. if (p->moreptr) *(p->moreptr) = 0; FreeDNSServiceOp(p); } } } DNSServiceErrorType DNSSD_API DNSServiceGetProperty(const char *property, void *result, uint32_t *size) { DNSServiceErrorType err; char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceOp *tmp; uint32_t actualsize; int ioresult; if (!property || !result || !size) return kDNSServiceErr_BadParam; len = strlen(property) + 1; err = ConnectToServer(&tmp, 0, getproperty_request, NULL, NULL, NULL); if (err) return err; hdr = create_hdr(getproperty_request, &len, &ptr, 0, tmp); if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; } put_string(property, &ptr); err = deliver_request(hdr, tmp); // Will free hdr for us if (err) { DNSServiceRefDeallocate(tmp); return err; } ioresult = read_all(tmp->sockfd, (char*)&actualsize, (int)sizeof(actualsize)); if (ioresult < read_all_success) { DNSServiceRefDeallocate(tmp); return (ioresult == read_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; } actualsize = ntohl(actualsize); ioresult = read_all(tmp->sockfd, (char*)result, actualsize < *size ? actualsize : *size); if (ioresult < read_all_success) { DNSServiceRefDeallocate(tmp); return (ioresult == read_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; } DNSServiceRefDeallocate(tmp); // Swap version result back to local process byte order if (!strcmp(property, kDNSServiceProperty_DaemonVersion) && *size >= 4) *(uint32_t*)result = ntohl(*(uint32_t*)result); *size = actualsize; return kDNSServiceErr_NoError; } DNSServiceErrorType DNSSD_API DNSServiceGetPID(const uint16_t srcport, int32_t *pid) { char *ptr; ipc_msg_hdr *hdr; DNSServiceOp *tmp = NULL; size_t len = sizeof(int32_t); int ioresult; DNSServiceErrorType err = ConnectToServer(&tmp, 0, getpid_request, NULL, NULL, NULL); if (err) return err; hdr = create_hdr(getpid_request, &len, &ptr, 0, tmp); if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; } put_uint16(srcport, &ptr); err = deliver_request(hdr, tmp); // Will free hdr for us if (err) { DNSServiceRefDeallocate(tmp); return err; } ioresult = read_all(tmp->sockfd, (char*)pid, sizeof(int32_t)); if (ioresult < read_all_success) { DNSServiceRefDeallocate(tmp); return (ioresult == read_all_defunct) ? kDNSServiceErr_DefunctConnection : kDNSServiceErr_ServiceNotRunning; } DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoError; } static void handle_resolve_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *end) { char fullname[kDNSServiceMaxDomainName]; char target[kDNSServiceMaxDomainName]; uint16_t txtlen; union { uint16_t s; u_char b[2]; } port; unsigned char *txtrecord; get_string(&data, end, fullname, kDNSServiceMaxDomainName); get_string(&data, end, target, kDNSServiceMaxDomainName); if (!data || data + 2 > end) goto fail; port.b[0] = *data++; port.b[1] = *data++; txtlen = get_uint16(&data, end); txtrecord = (unsigned char *)get_rdata(&data, end, txtlen); if (!data) goto fail; ((DNSServiceResolveReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, fullname, target, port.s, txtlen, txtrecord, sdr->AppContext); return; // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function fail: syslog(LOG_WARNING, "dnssd_clientstub handle_resolve_response: error reading result from daemon"); } #if TARGET_OS_IPHONE static int32_t libSystemVersion = 0; // Return true if the iOS application linked against a version of libsystem where P2P // interfaces were included by default when using kDNSServiceInterfaceIndexAny. // Using 160.0.0 == 0xa00000 as the version threshold. static int includeP2PWithIndexAny() { if (libSystemVersion == 0) libSystemVersion = NSVersionOfLinkTimeLibrary("System"); if (libSystemVersion < 0xa00000) return 1; else return 0; } #else // TARGET_OS_IPHONE // always return false for non iOS platforms static int includeP2PWithIndexAny() { return 0; } #endif // TARGET_OS_IPHONE DNSServiceErrorType DNSSD_API DNSServiceResolve ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, const char *regtype, const char *domain, DNSServiceResolveReply callBack, void *context ) { char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceErrorType err; if (!sdRef || !name || !regtype || !domain || !callBack) return kDNSServiceErr_BadParam; // Need a real InterfaceID for WakeOnResolve if ((flags & kDNSServiceFlagsWakeOnResolve) != 0 && ((interfaceIndex == kDNSServiceInterfaceIndexAny) || (interfaceIndex == kDNSServiceInterfaceIndexLocalOnly) || (interfaceIndex == kDNSServiceInterfaceIndexUnicast) || (interfaceIndex == kDNSServiceInterfaceIndexP2P) || (interfaceIndex == kDNSServiceInterfaceIndexBLE))) { return kDNSServiceErr_BadParam; } if ((interfaceIndex == kDNSServiceInterfaceIndexAny) && includeP2PWithIndexAny()) flags |= kDNSServiceFlagsIncludeP2P; err = ConnectToServer(sdRef, flags, resolve_request, handle_resolve_response, (void *)callBack, context); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL // Calculate total message length len = sizeof(flags); len += sizeof(interfaceIndex); len += strlen(name) + 1; len += strlen(regtype) + 1; len += strlen(domain) + 1; hdr = create_hdr(resolve_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_string(name, &ptr); put_string(regtype, &ptr); put_string(domain, &ptr); err = deliver_request(hdr, *sdRef); // Will free hdr for us #if CHECK_BUNDLE_VERSION if (err == kDNSServiceErr_NoAuth && !_should_return_noauth_error()) { err = kDNSServiceErr_NoError; } #endif if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } static void handle_query_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end) { #if CHECK_BUNDLE_VERSION if (cbh->cb_err == kDNSServiceErr_PolicyDenied && !_should_return_noauth_error()) { return; } #endif uint32_t ttl; char name[kDNSServiceMaxDomainName]; uint16_t rrtype, rrclass, rdlen; const char *rdata; get_string(&data, end, name, kDNSServiceMaxDomainName); rrtype = get_uint16(&data, end); rrclass = get_uint16(&data, end); rdlen = get_uint16(&data, end); rdata = get_rdata(&data, end, rdlen); ttl = get_uint32(&data, end); if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_query_response: error reading result from daemon"); else ((DNSServiceQueryRecordReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, name, rrtype, rrclass, rdlen, rdata, ttl, sdr->AppContext); // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function } #if APPLE_OSX_mDNSResponder static size_t get_required_length_for_defaults(const xpc_object_t defaults) { size_t required_len = 0; size_t plist_data_len = 0; // Add length for IPC_TLV_TYPE_RESOLVER_CONFIG_PLIST_DATA. if (xpc_dictionary_get_data(defaults, kDNSServiceDefaultsKey_ResolverConfigPListData, &plist_data_len)) { required_len += get_required_tlv16_length(plist_data_len); } // Add length for IPC_TLV_TYPE_REQUIRE_PRIVACY. required_len += get_required_tlv16_length(sizeof(uint8_t)); return required_len; } static void put_tlvs_for_defaults(const xpc_object_t defaults, ipc_msg_hdr *const hdr, char **ptr) { uint8_t require_privacy; size_t plist_data_len = 0; const uint8_t *const plist_data_ptr = xpc_dictionary_get_data(defaults, kDNSServiceDefaultsKey_ResolverConfigPListData, &plist_data_len); if (plist_data_ptr) { put_tlv16(IPC_TLV_TYPE_RESOLVER_CONFIG_PLIST_DATA, (uint16_t)plist_data_len, plist_data_ptr, ptr); } require_privacy = xpc_dictionary_get_bool(defaults, kDNSServiceDefaultsKey_RequirePrivacy) ? 1 : 0; put_tlv16(IPC_TLV_TYPE_REQUIRE_PRIVACY, sizeof(require_privacy), &require_privacy, ptr); hdr->ipc_flags |= IPC_FLAGS_TRAILING_TLVS; } #endif DNSServiceErrorType DNSSD_API DNSServiceQueryRecord ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, uint16_t rrtype, uint16_t rrclass, DNSServiceQueryRecordReply callBack, void *context ) { char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceErrorType err; #if APPLE_OSX_mDNSResponder xpc_object_t defaults; #endif // NULL name handled below. if (!sdRef || !callBack) return kDNSServiceErr_BadParam; if ((interfaceIndex == kDNSServiceInterfaceIndexAny) && includeP2PWithIndexAny()) flags |= kDNSServiceFlagsIncludeP2P; err = ConnectToServer(sdRef, flags, query_request, handle_query_response, (void *)callBack, context); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL if (!name) name = "\0"; // Calculate total message length len = sizeof(flags); len += sizeof(uint32_t); // interfaceIndex len += strlen(name) + 1; len += 2 * sizeof(uint16_t); // rrtype, rrclass #if APPLE_OSX_mDNSResponder defaults = DNSServiceGetRetainedResolverDefaults(); if (defaults) { len += get_required_length_for_defaults(defaults); } #endif hdr = create_hdr(query_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; #if APPLE_OSX_mDNSResponder xpc_forget(&defaults); #endif return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_string(name, &ptr); put_uint16(rrtype, &ptr); put_uint16(rrclass, &ptr); #if APPLE_OSX_mDNSResponder if (defaults) { put_tlvs_for_defaults(defaults, hdr, &ptr); xpc_forget(&defaults); } #endif err = deliver_request(hdr, *sdRef); // Will free hdr for us #if CHECK_BUNDLE_VERSION if (err == kDNSServiceErr_NoAuth && !_should_return_noauth_error()) { err = kDNSServiceErr_NoError; } #endif if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } static void handle_addrinfo_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end) { #if CHECK_BUNDLE_VERSION if (cbh->cb_err == kDNSServiceErr_PolicyDenied && !_should_return_noauth_error()) { return; } #endif char hostname[kDNSServiceMaxDomainName]; uint16_t rrtype, rrclass, rdlen; const char *rdata; uint32_t ttl; get_string(&data, end, hostname, kDNSServiceMaxDomainName); rrtype = get_uint16(&data, end); rrclass = get_uint16(&data, end); rdlen = get_uint16(&data, end); rdata = get_rdata (&data, end, rdlen); ttl = get_uint32(&data, end); (void)rrclass; // Unused // We only generate client callbacks for A and AAAA results (including NXDOMAIN results for // those types, if the client has requested those with the kDNSServiceFlagsReturnIntermediates). // Other result types, specifically CNAME referrals, are not communicated to the client, because // the DNSServiceGetAddrInfoReply interface doesn't have any meaningful way to communiate CNAME referrals. if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_addrinfo_response: error reading result from daemon"); else if (rrtype == kDNSServiceType_A || rrtype == kDNSServiceType_AAAA) { struct sockaddr_in sa4; struct sockaddr_in6 sa6; const struct sockaddr *const sa = (rrtype == kDNSServiceType_A) ? (struct sockaddr*)&sa4 : (struct sockaddr*)&sa6; if (rrtype == kDNSServiceType_A) { memset(&sa4, 0, sizeof(sa4)); #ifndef NOT_HAVE_SA_LEN sa4.sin_len = sizeof(struct sockaddr_in); #endif sa4.sin_family = AF_INET; // sin_port = 0; if (!cbh->cb_err) memcpy(&sa4.sin_addr, rdata, rdlen); } else { memset(&sa6, 0, sizeof(sa6)); #ifndef NOT_HAVE_SA_LEN sa6.sin6_len = sizeof(struct sockaddr_in6); #endif sa6.sin6_family = AF_INET6; // sin6_port = 0; // sin6_flowinfo = 0; // sin6_scope_id = 0; if (!cbh->cb_err) { memcpy(&sa6.sin6_addr, rdata, rdlen); if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr)) sa6.sin6_scope_id = cbh->cb_interface; } } ((DNSServiceGetAddrInfoReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, hostname, sa, ttl, sdr->AppContext); } else if (cbh->cb_err == kDNSServiceErr_PolicyDenied) { ((DNSServiceGetAddrInfoReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, hostname, NULL, ttl, sdr->AppContext); } } DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, uint32_t protocol, const char *hostname, DNSServiceGetAddrInfoReply callBack, void *context /* may be NULL */ ) { char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceErrorType err; #if APPLE_OSX_mDNSResponder xpc_object_t defaults; #endif if (!sdRef || !hostname || !callBack) return kDNSServiceErr_BadParam; err = ConnectToServer(sdRef, flags, addrinfo_request, handle_addrinfo_response, (void *)callBack, context); if (err) { return err; // On error ConnectToServer leaves *sdRef set to NULL } // Calculate total message length len = sizeof(flags); len += sizeof(uint32_t); // interfaceIndex len += sizeof(uint32_t); // protocol len += strlen(hostname) + 1; #if APPLE_OSX_mDNSResponder defaults = DNSServiceGetRetainedResolverDefaults(); if (defaults) { len += get_required_length_for_defaults(defaults); } #endif hdr = create_hdr(addrinfo_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; #if APPLE_OSX_mDNSResponder xpc_forget(&defaults); #endif return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_uint32(protocol, &ptr); put_string(hostname, &ptr); #if APPLE_OSX_mDNSResponder if (defaults) { put_tlvs_for_defaults(defaults, hdr, &ptr); xpc_forget(&defaults); } #endif err = deliver_request(hdr, *sdRef); // Will free hdr for us #if CHECK_BUNDLE_VERSION if (err == kDNSServiceErr_NoAuth && !_should_return_noauth_error()) { err = kDNSServiceErr_NoError; } #endif if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } static void handle_browse_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end) { #if CHECK_BUNDLE_VERSION if (cbh->cb_err == kDNSServiceErr_PolicyDenied && !_should_return_noauth_error()) { return; } #endif char replyName[256], replyType[kDNSServiceMaxDomainName], replyDomain[kDNSServiceMaxDomainName]; get_string(&data, end, replyName, 256); get_string(&data, end, replyType, kDNSServiceMaxDomainName); get_string(&data, end, replyDomain, kDNSServiceMaxDomainName); if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_browse_response: error reading result from daemon"); else ((DNSServiceBrowseReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, replyName, replyType, replyDomain, sdr->AppContext); // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function } DNSServiceErrorType DNSSD_API DNSServiceBrowse ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *regtype, const char *domain, DNSServiceBrowseReply callBack, void *context ) { char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceErrorType err; // NULL domain handled below if (!sdRef || !regtype || !callBack) return kDNSServiceErr_BadParam; if ((interfaceIndex == kDNSServiceInterfaceIndexAny) && includeP2PWithIndexAny()) flags |= kDNSServiceFlagsIncludeP2P; err = ConnectToServer(sdRef, flags, browse_request, handle_browse_response, (void *)callBack, context); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL if (!domain) domain = ""; len = sizeof(flags); len += sizeof(interfaceIndex); len += strlen(regtype) + 1; len += strlen(domain) + 1; hdr = create_hdr(browse_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_string(regtype, &ptr); put_string(domain, &ptr); err = deliver_request(hdr, *sdRef); // Will free hdr for us #if CHECK_BUNDLE_VERSION if (err == kDNSServiceErr_NoAuth && !_should_return_noauth_error()) { err = kDNSServiceErr_NoError; } #endif if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } DNSServiceErrorType DNSSD_API DNSServiceSetDefaultDomainForUser(DNSServiceFlags flags, const char *domain) { DNSServiceErrorType err; DNSServiceOp *tmp; char *ptr; size_t len; ipc_msg_hdr *hdr; if (!domain) return kDNSServiceErr_BadParam; len = sizeof(flags) + strlen(domain) + 1; err = ConnectToServer(&tmp, 0, setdomain_request, NULL, NULL, NULL); if (err) return err; hdr = create_hdr(setdomain_request, &len, &ptr, 0, tmp); if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_string(domain, &ptr); err = deliver_request(hdr, tmp); // Will free hdr for us DNSServiceRefDeallocate(tmp); return err; } static void handle_regservice_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end) { #if CHECK_BUNDLE_VERSION if (cbh->cb_err == kDNSServiceErr_PolicyDenied && !_should_return_noauth_error()) { return; } #endif char name[256], regtype[kDNSServiceMaxDomainName], domain[kDNSServiceMaxDomainName]; get_string(&data, end, name, 256); get_string(&data, end, regtype, kDNSServiceMaxDomainName); get_string(&data, end, domain, kDNSServiceMaxDomainName); if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_regservice_response: error reading result from daemon"); else ((DNSServiceRegisterReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_err, name, regtype, domain, sdr->AppContext); // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function } DNSServiceErrorType DNSSD_API DNSServiceRegister ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, const char *regtype, const char *domain, const char *host, uint16_t PortInNetworkByteOrder, uint16_t txtLen, const void *txtRecord, DNSServiceRegisterReply callBack, void *context ) { char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceErrorType err; union { uint16_t s; u_char b[2]; } port = { PortInNetworkByteOrder }; if (!sdRef || !regtype) return kDNSServiceErr_BadParam; if (!name) name = ""; if (!domain) domain = ""; if (!host) host = ""; if (!txtRecord) txtRecord = (void*)""; // No callback must have auto-rename if (!callBack && (flags & kDNSServiceFlagsNoAutoRename)) return kDNSServiceErr_BadParam; if ((interfaceIndex == kDNSServiceInterfaceIndexAny) && includeP2PWithIndexAny()) flags |= kDNSServiceFlagsIncludeP2P; err = ConnectToServer(sdRef, flags, reg_service_request, callBack ? handle_regservice_response : NULL, (void *)callBack, context); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL len = sizeof(DNSServiceFlags); len += sizeof(uint32_t); // interfaceIndex len += strlen(name) + strlen(regtype) + strlen(domain) + strlen(host) + 4; len += 2 * sizeof(uint16_t); // port, txtLen len += txtLen; hdr = create_hdr(reg_service_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } if (!callBack) hdr->ipc_flags |= IPC_FLAGS_NOREPLY; put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_string(name, &ptr); put_string(regtype, &ptr); put_string(domain, &ptr); put_string(host, &ptr); *ptr++ = port.b[0]; *ptr++ = port.b[1]; put_uint16(txtLen, &ptr); put_rdata(txtLen, txtRecord, &ptr); err = deliver_request(hdr, *sdRef); // Will free hdr for us #if CHECK_BUNDLE_VERSION if (err == kDNSServiceErr_NoAuth && !_should_return_noauth_error()) { err = kDNSServiceErr_NoError; } #endif if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } static void handle_enumeration_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end) { char domain[kDNSServiceMaxDomainName]; get_string(&data, end, domain, kDNSServiceMaxDomainName); if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_enumeration_response: error reading result from daemon"); else ((DNSServiceDomainEnumReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, domain, sdr->AppContext); // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function } DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceDomainEnumReply callBack, void *context ) { char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceErrorType err; int f1; int f2; if (!sdRef || !callBack) return kDNSServiceErr_BadParam; f1 = (flags & kDNSServiceFlagsBrowseDomains) != 0; f2 = (flags & kDNSServiceFlagsRegistrationDomains) != 0; if (f1 + f2 != 1) return kDNSServiceErr_BadParam; err = ConnectToServer(sdRef, flags, enumeration_request, handle_enumeration_response, (void *)callBack, context); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL len = sizeof(DNSServiceFlags); len += sizeof(uint32_t); hdr = create_hdr(enumeration_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); err = deliver_request(hdr, *sdRef); // Will free hdr for us if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } static void ConnectionResponse(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *const data, const char *const end) { (void)data; // Unused //printf("ConnectionResponse got %d\n", cbh->ipc_hdr.op); if (cbh->ipc_hdr.op != reg_record_reply_op) { // When using kDNSServiceFlagsShareConnection, need to search the list of associated DNSServiceOps // to find the one this response is intended for, and then call through to its ProcessReply handler. // We start with our first subordinate DNSServiceRef -- don't want to accidentally match the parent DNSServiceRef. DNSServiceOp *op = sdr->next; while (op && (op->uid.u32[0] != cbh->ipc_hdr.client_context.u32[0] || op->uid.u32[1] != cbh->ipc_hdr.client_context.u32[1])) op = op->next; // Note: We may sometimes not find a matching DNSServiceOp, in the case where the client has // cancelled the subordinate DNSServiceOp, but there are still messages in the pipeline from the daemon if (op && op->ProcessReply) op->ProcessReply(op, cbh, data, end); // WARNING: Don't touch op or sdr after this -- client may have called DNSServiceRefDeallocate return; } else { #if CHECK_BUNDLE_VERSION if (cbh->cb_err == kDNSServiceErr_PolicyDenied && !_should_return_noauth_error()) { return; } #endif DNSRecordRef rec; for (rec = sdr->rec; rec; rec = rec->recnext) { if (rec->uid.u32[0] == cbh->ipc_hdr.client_context.u32[0] && rec->uid.u32[1] == cbh->ipc_hdr.client_context.u32[1]) break; } // The record might have been freed already and hence not an // error if the record is not found. if (!rec) { syslog(LOG_INFO, "dnssd_clientstub ConnectionResponse: Record not found"); return; } if (rec->sdr != sdr) { syslog(LOG_WARNING, "dnssd_clientstub ConnectionResponse: Record sdr mismatch: rec %p sdr %p", rec->sdr, sdr); return; } if (sdr->op == connection_request || sdr->op == connection_delegate_request) { rec->AppCallback(rec->sdr, rec, cbh->cb_flags, cbh->cb_err, rec->AppContext); } else { syslog(LOG_WARNING, "dnssd_clientstub ConnectionResponse: sdr->op != connection_request"); rec->AppCallback(rec->sdr, rec, 0, kDNSServiceErr_Unknown, rec->AppContext); } // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function } } DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef) { DNSServiceErrorType err; char *ptr; size_t len = 0; ipc_msg_hdr *hdr; if (!sdRef) return kDNSServiceErr_BadParam; err = ConnectToServer(sdRef, 0, connection_request, ConnectionResponse, NULL, NULL); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL hdr = create_hdr(connection_request, &len, &ptr, 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } err = deliver_request(hdr, *sdRef); // Will free hdr for us if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } #if APPLE_OSX_mDNSResponder && !TARGET_OS_SIMULATOR DNSServiceErrorType DNSSD_API DNSServiceCreateDelegateConnection(DNSServiceRef *sdRef, int32_t pid, uuid_t uuid) { char *ptr; size_t len = 0; ipc_msg_hdr *hdr; if (!sdRef) return kDNSServiceErr_BadParam; DNSServiceErrorType err = ConnectToServer(sdRef, 0, connection_delegate_request, ConnectionResponse, NULL, NULL); if (err) { return err; // On error ConnectToServer leaves *sdRef set to NULL } // Only one of the two options can be set. If pid is zero, uuid is used. // If both are specified only pid will be used. We send across the pid // so that the daemon knows what to read from the socket. len += sizeof(int32_t); hdr = create_hdr(connection_delegate_request, &len, &ptr, 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } if (pid && setsockopt((*sdRef)->sockfd, SOL_SOCKET, SO_DELEGATED, &pid, sizeof(pid)) == -1) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceCreateDelegateConnection: Could not setsockopt() for PID[%d], no entitlements or process(pid) invalid errno:%d (%s)", pid, errno, strerror(errno)); // Free the hdr in case we return before calling deliver_request() if (hdr) free(hdr); DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoAuth; } if (!pid && setsockopt((*sdRef)->sockfd, SOL_SOCKET, SO_DELEGATED_UUID, uuid, sizeof(uuid_t)) == -1) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceCreateDelegateConnection: Could not setsockopt() for UUID, no entitlements or process(uuid) invalid errno:%d (%s) ", errno, strerror(errno)); // Free the hdr in case we return before calling deliver_request() if (hdr) free(hdr); DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoAuth; } put_uint32(pid, &ptr); err = deliver_request(hdr, *sdRef); // Will free hdr for us if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } #elif TARGET_OS_SIMULATOR // This hack is for Simulator platform only DNSServiceErrorType DNSSD_API DNSServiceCreateDelegateConnection(DNSServiceRef *sdRef, int32_t pid, uuid_t uuid) { (void) pid; (void) uuid; return DNSServiceCreateConnection(sdRef); } #endif DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord ( DNSServiceRef sdRef, DNSRecordRef *RecordRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, DNSServiceRegisterRecordReply callBack, void *context ) { DNSServiceErrorType err; char *ptr; size_t len; ipc_msg_hdr *hdr = NULL; DNSRecordRef rref = NULL; DNSRecord **p; // Verify that only one of the following flags is set. int f1 = (flags & kDNSServiceFlagsShared) != 0; int f2 = (flags & kDNSServiceFlagsUnique) != 0; int f3 = (flags & kDNSServiceFlagsKnownUnique) != 0; if (f1 + f2 + f3 != 1) return kDNSServiceErr_BadParam; if ((interfaceIndex == kDNSServiceInterfaceIndexAny) && includeP2PWithIndexAny()) flags |= kDNSServiceFlagsIncludeP2P; if (!sdRef || !RecordRef || !fullname || (!rdata && rdlen) || !callBack) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRegisterRecord called with NULL parameter"); return kDNSServiceErr_BadParam; } if (!DNSServiceRefValid(sdRef)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRegisterRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return kDNSServiceErr_BadReference; } if (sdRef->op != connection_request && sdRef->op != connection_delegate_request) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRegisterRecord called with non-DNSServiceCreateConnection DNSServiceRef %p %d", sdRef, sdRef->op); return kDNSServiceErr_BadReference; } *RecordRef = NULL; len = sizeof(DNSServiceFlags); len += 2 * sizeof(uint32_t); // interfaceIndex, ttl len += 3 * sizeof(uint16_t); // rrtype, rrclass, rdlen len += strlen(fullname) + 1; len += rdlen; // Bump up the uid. Normally for shared operations (kDNSServiceFlagsShareConnection), this // is done in ConnectToServer. For DNSServiceRegisterRecord, ConnectToServer has already // been called. As multiple DNSServiceRegisterRecords can be multiplexed over a single // connection, we need a way to demultiplex the response so that the callback corresponding // to the right DNSServiceRegisterRecord instance can be called. Use the same mechanism that // is used by kDNSServiceFlagsShareConnection. create_hdr copies the uid value to ipc // hdr->client_context which will be returned in the ipc response. if (++sdRef->uid.u32[0] == 0) ++sdRef->uid.u32[1]; hdr = create_hdr(reg_record_request, &len, &ptr, 1, sdRef); if (!hdr) return kDNSServiceErr_NoMemory; put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_string(fullname, &ptr); put_uint16(rrtype, &ptr); put_uint16(rrclass, &ptr); put_uint16(rdlen, &ptr); put_rdata(rdlen, rdata, &ptr); put_uint32(ttl, &ptr); rref = malloc(sizeof(DNSRecord)); if (!rref) { free(hdr); return kDNSServiceErr_NoMemory; } rref->AppContext = context; rref->AppCallback = callBack; rref->record_index = sdRef->max_index++; rref->sdr = sdRef; rref->recnext = NULL; *RecordRef = rref; // Remember the uid that we are sending across so that we can match // when the response comes back. rref->uid = sdRef->uid; hdr->reg_index = rref->record_index; p = &(sdRef)->rec; while (*p) p = &(*p)->recnext; *p = rref; err = deliver_request(hdr, sdRef); // Will free hdr for us #if CHECK_BUNDLE_VERSION if (err == kDNSServiceErr_NoAuth && !_should_return_noauth_error()) { err = kDNSServiceErr_NoError; } #endif return err; } // sdRef returned by DNSServiceRegister() DNSServiceErrorType DNSSD_API DNSServiceAddRecord ( DNSServiceRef sdRef, DNSRecordRef *RecordRef, DNSServiceFlags flags, uint16_t rrtype, uint16_t rdlen, const void *rdata, uint32_t ttl ) { ipc_msg_hdr *hdr; size_t len = 0; char *ptr; DNSRecordRef rref; DNSRecord **p; if (!sdRef || !RecordRef || (!rdata && rdlen)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with NULL parameter"); return kDNSServiceErr_BadParam; } if (sdRef->op != reg_service_request) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with non-DNSServiceRegister DNSServiceRef %p %d", sdRef, sdRef->op); return kDNSServiceErr_BadReference; } if (!DNSServiceRefValid(sdRef)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return kDNSServiceErr_BadReference; } *RecordRef = NULL; len += 2 * sizeof(uint16_t); // rrtype, rdlen len += rdlen; len += sizeof(uint32_t); len += sizeof(DNSServiceFlags); hdr = create_hdr(add_record_request, &len, &ptr, 1, sdRef); if (!hdr) return kDNSServiceErr_NoMemory; put_flags(flags, &ptr); put_uint16(rrtype, &ptr); put_uint16(rdlen, &ptr); put_rdata(rdlen, rdata, &ptr); put_uint32(ttl, &ptr); rref = malloc(sizeof(DNSRecord)); if (!rref) { free(hdr); return kDNSServiceErr_NoMemory; } rref->AppContext = NULL; rref->AppCallback = NULL; rref->record_index = sdRef->max_index++; rref->sdr = sdRef; rref->recnext = NULL; *RecordRef = rref; hdr->reg_index = rref->record_index; p = &(sdRef)->rec; while (*p) p = &(*p)->recnext; *p = rref; return deliver_request(hdr, sdRef); // Will free hdr for us } // DNSRecordRef returned by DNSServiceRegisterRecord or DNSServiceAddRecord DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord ( DNSServiceRef sdRef, DNSRecordRef RecordRef, DNSServiceFlags flags, uint16_t rdlen, const void *rdata, uint32_t ttl ) { ipc_msg_hdr *hdr; size_t len = 0; char *ptr; if (!sdRef || (!rdata && rdlen)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceUpdateRecord called with NULL parameter"); return kDNSServiceErr_BadParam; } if (!DNSServiceRefValid(sdRef)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceUpdateRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return kDNSServiceErr_BadReference; } // Note: RecordRef is allowed to be NULL len += sizeof(uint16_t); len += rdlen; len += sizeof(uint32_t); len += sizeof(DNSServiceFlags); hdr = create_hdr(update_record_request, &len, &ptr, 1, sdRef); if (!hdr) return kDNSServiceErr_NoMemory; hdr->reg_index = RecordRef ? RecordRef->record_index : TXT_RECORD_INDEX; put_flags(flags, &ptr); put_uint16(rdlen, &ptr); put_rdata(rdlen, rdata, &ptr); put_uint32(ttl, &ptr); return deliver_request(hdr, sdRef); // Will free hdr for us } DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord ( DNSServiceRef sdRef, DNSRecordRef RecordRef, DNSServiceFlags flags ) { ipc_msg_hdr *hdr; size_t len = 0; char *ptr; DNSServiceErrorType err; if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; } if (!RecordRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with NULL DNSRecordRef"); return kDNSServiceErr_BadParam; } if (!sdRef->max_index) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with bad DNSServiceRef"); return kDNSServiceErr_BadReference; } if (!DNSServiceRefValid(sdRef)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator); return kDNSServiceErr_BadReference; } len += sizeof(flags); hdr = create_hdr(remove_record_request, &len, &ptr, 1, sdRef); if (!hdr) return kDNSServiceErr_NoMemory; hdr->reg_index = RecordRef->record_index; put_flags(flags, &ptr); err = deliver_request(hdr, sdRef); // Will free hdr for us if (!err) { // This RecordRef could have been allocated in DNSServiceRegisterRecord or DNSServiceAddRecord. // If so, delink from the list before freeing DNSRecord **p = &sdRef->rec; while (*p && *p != RecordRef) p = &(*p)->recnext; if (*p) *p = RecordRef->recnext; free(RecordRef); } return err; } DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord ( DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata ) { DNSServiceErrorType err; char *ptr; size_t len; ipc_msg_hdr *hdr; DNSServiceOp *tmp = NULL; if (!fullname || (!rdata && rdlen)) return kDNSServiceErr_BadParam; err = ConnectToServer(&tmp, flags, reconfirm_record_request, NULL, NULL, NULL); if (err) return err; len = sizeof(DNSServiceFlags); len += sizeof(uint32_t); len += strlen(fullname) + 1; len += 3 * sizeof(uint16_t); len += rdlen; hdr = create_hdr(reconfirm_record_request, &len, &ptr, 0, tmp); if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_string(fullname, &ptr); put_uint16(rrtype, &ptr); put_uint16(rrclass, &ptr); put_uint16(rdlen, &ptr); put_rdata(rdlen, rdata, &ptr); err = deliver_request(hdr, tmp); // Will free hdr for us DNSServiceRefDeallocate(tmp); return err; } static void handle_port_mapping_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end) { union { uint32_t l; u_char b[4]; } addr; uint8_t protocol; union { uint16_t s; u_char b[2]; } internalPort; union { uint16_t s; u_char b[2]; } externalPort; uint32_t ttl; if (!data || data + 13 > end) goto fail; addr.b[0] = *data++; addr.b[1] = *data++; addr.b[2] = *data++; addr.b[3] = *data++; protocol = *data++; internalPort.b[0] = *data++; internalPort.b[1] = *data++; externalPort.b[0] = *data++; externalPort.b[1] = *data++; ttl = get_uint32(&data, end); if (!data) goto fail; ((DNSServiceNATPortMappingReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, addr.l, protocol, internalPort.s, externalPort.s, ttl, sdr->AppContext); return; // MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function fail : syslog(LOG_WARNING, "dnssd_clientstub handle_port_mapping_response: error reading result from daemon"); } DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, uint32_t protocol, /* TCP and/or UDP */ uint16_t internalPortInNetworkByteOrder, uint16_t externalPortInNetworkByteOrder, uint32_t ttl, /* time to live in seconds */ DNSServiceNATPortMappingReply callBack, void *context /* may be NULL */ ) { char *ptr; size_t len; ipc_msg_hdr *hdr; union { uint16_t s; u_char b[2]; } internalPort = { internalPortInNetworkByteOrder }; union { uint16_t s; u_char b[2]; } externalPort = { externalPortInNetworkByteOrder }; DNSServiceErrorType err = ConnectToServer(sdRef, flags, port_mapping_request, handle_port_mapping_response, (void *)callBack, context); if (err) return err; // On error ConnectToServer leaves *sdRef set to NULL len = sizeof(flags); len += sizeof(interfaceIndex); len += sizeof(protocol); len += sizeof(internalPort); len += sizeof(externalPort); len += sizeof(ttl); hdr = create_hdr(port_mapping_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef); if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; } put_flags(flags, &ptr); put_uint32(interfaceIndex, &ptr); put_uint32(protocol, &ptr); *ptr++ = internalPort.b[0]; *ptr++ = internalPort.b[1]; *ptr++ = externalPort.b[0]; *ptr++ = externalPort.b[1]; put_uint32(ttl, &ptr); err = deliver_request(hdr, *sdRef); // Will free hdr for us if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; } return err; } #if _DNS_SD_LIBDISPATCH DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue ( DNSServiceRef service, dispatch_queue_t queue ) { int dnssd_fd = DNSServiceRefSockFD(service); if (dnssd_fd == dnssd_InvalidSocket) return kDNSServiceErr_BadParam; if (!queue) { syslog(LOG_WARNING, "dnssd_clientstub: DNSServiceSetDispatchQueue dispatch queue NULL"); return kDNSServiceErr_BadParam; } if (service->disp_queue) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSetDispatchQueue dispatch queue set already"); return kDNSServiceErr_BadParam; } if (service->disp_source) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSetDispatchQueue dispatch source set already"); return kDNSServiceErr_BadParam; } service->disp_source = dispatch_source_create(DISPATCH_SOURCE_TYPE_READ, dnssd_fd, 0, queue); if (!service->disp_source) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSetDispatchQueue dispatch_source_create failed"); return kDNSServiceErr_NoMemory; } service->disp_queue = queue; dispatch_source_set_event_handler(service->disp_source, ^{DNSServiceProcessResult(service);}); dispatch_source_set_cancel_handler(service->disp_source, ^{dnssd_close(dnssd_fd);}); dispatch_resume(service->disp_source); return kDNSServiceErr_NoError; } #endif // _DNS_SD_LIBDISPATCH #if !defined(_WIN32) static void DNSSD_API SleepKeepaliveCallback(DNSServiceRef sdRef, DNSRecordRef rec, const DNSServiceFlags flags, DNSServiceErrorType errorCode, void *context) { SleepKAContext *ka = (SleepKAContext *)context; (void)rec; // Unused (void)flags; // Unused if (sdRef->kacontext != context) syslog(LOG_WARNING, "dnssd_clientstub SleepKeepaliveCallback context mismatch"); if (ka->AppCallback) ((DNSServiceSleepKeepaliveReply)ka->AppCallback)(sdRef, errorCode, ka->AppContext); } static DNSServiceErrorType _DNSServiceSleepKeepalive_sockaddr ( DNSServiceRef * sdRef, DNSServiceFlags flags, const struct sockaddr * localAddr, const struct sockaddr * remoteAddr, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void * context ); DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive ( DNSServiceRef *sdRef, DNSServiceFlags flags, int fd, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void *context ) { struct sockaddr_storage lss; struct sockaddr_storage rss; socklen_t len1, len2; len1 = sizeof(lss); if (getsockname(fd, (struct sockaddr *)&lss, &len1) < 0) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive: getsockname %d\n", errno); return kDNSServiceErr_BadParam; } len2 = sizeof(rss); if (getpeername(fd, (struct sockaddr *)&rss, &len2) < 0) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive: getpeername %d\n", errno); return kDNSServiceErr_BadParam; } if (len1 != len2) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive local/remote info not same"); return kDNSServiceErr_Unknown; } return _DNSServiceSleepKeepalive_sockaddr(sdRef, flags, (const struct sockaddr *)&lss, (const struct sockaddr *)&rss, timeout, callBack, context); } DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive_sockaddr ( DNSServiceRef * sdRef, DNSServiceFlags flags, const struct sockaddr * localAddr, const struct sockaddr * remoteAddr, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void * context ) { return _DNSServiceSleepKeepalive_sockaddr(sdRef, flags, localAddr, remoteAddr, timeout, callBack, context ); } static DNSServiceErrorType _DNSServiceSleepKeepalive_sockaddr ( DNSServiceRef * sdRef, DNSServiceFlags flags, const struct sockaddr * localAddr, const struct sockaddr * remoteAddr, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void * context ) { char source_str[INET6_ADDRSTRLEN]; char target_str[INET6_ADDRSTRLEN]; unsigned int len, proxyreclen; char buf[256]; DNSServiceErrorType err; DNSRecordRef record = NULL; char name[10]; char recname[128]; SleepKAContext *ka; unsigned int i, unique; (void) flags; //unused if (!timeout) return kDNSServiceErr_BadParam; unique = 0; if ((localAddr->sa_family == AF_INET) && (remoteAddr->sa_family == AF_INET)) { const struct sockaddr_in *sl = (const struct sockaddr_in *)localAddr; const struct sockaddr_in *sr = (const struct sockaddr_in *)remoteAddr; unsigned char *ptr = (unsigned char *)&sl->sin_addr; if (!inet_ntop(AF_INET, (const void *)&sr->sin_addr, target_str, sizeof (target_str))) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive remote info failed %d", errno); return kDNSServiceErr_Unknown; } if (!inet_ntop(AF_INET, (const void *)&sl->sin_addr, source_str, sizeof (source_str))) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive local info failed %d", errno); return kDNSServiceErr_Unknown; } // Sum of all bytes in the local address and port should result in a unique // number in the local network for (i = 0; i < sizeof(struct in_addr); i++) unique += ptr[i]; unique += sl->sin_port; len = snprintf(buf+1, sizeof(buf) - 1, "t=%u h=%s d=%s l=%u r=%u", timeout, source_str, target_str, ntohs(sl->sin_port), ntohs(sr->sin_port)); } else if ((localAddr->sa_family == AF_INET6) && (remoteAddr->sa_family == AF_INET6)) { const struct sockaddr_in6 *sl6 = (const struct sockaddr_in6 *)localAddr; const struct sockaddr_in6 *sr6 = (const struct sockaddr_in6 *)remoteAddr; unsigned char *ptr = (unsigned char *)&sl6->sin6_addr; if (!inet_ntop(AF_INET6, (const void *)&sr6->sin6_addr, target_str, sizeof (target_str))) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive remote6 info failed %d", errno); return kDNSServiceErr_Unknown; } if (!inet_ntop(AF_INET6, (const void *)&sl6->sin6_addr, source_str, sizeof (source_str))) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive local6 info failed %d", errno); return kDNSServiceErr_Unknown; } for (i = 0; i < sizeof(struct in6_addr); i++) unique += ptr[i]; unique += sl6->sin6_port; len = snprintf(buf+1, sizeof(buf) - 1, "t=%u H=%s D=%s l=%u r=%u", timeout, source_str, target_str, ntohs(sl6->sin6_port), ntohs(sr6->sin6_port)); } else { return kDNSServiceErr_BadParam; } if (len >= (sizeof(buf) - 1)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive could not fit local/remote info"); return kDNSServiceErr_Unknown; } // Include the NULL byte also in the first byte. The total length of the record includes the // first byte also. buf[0] = len + 1; proxyreclen = len + 2; len = snprintf(name, sizeof(name), "%u", unique); if (len >= sizeof(name)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive could not fit unique"); return kDNSServiceErr_Unknown; } len = snprintf(recname, sizeof(recname), "%s.%s", name, "_keepalive._dns-sd._udp.local"); if (len >= sizeof(recname)) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive could not fit name"); return kDNSServiceErr_Unknown; } ka = malloc(sizeof(SleepKAContext)); if (!ka) return kDNSServiceErr_NoMemory; ka->AppCallback = (void *)callBack; ka->AppContext = context; err = DNSServiceCreateConnection(sdRef); if (err) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive cannot create connection"); free(ka); return err; } // we don't care about the "record". When sdRef gets deallocated later, it will be freed too err = DNSServiceRegisterRecord(*sdRef, &record, kDNSServiceFlagsUnique, 0, recname, kDNSServiceType_NULL, kDNSServiceClass_IN, proxyreclen, buf, kDNSServiceInterfaceIndexAny, SleepKeepaliveCallback, ka); if (err) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSleepKeepalive cannot create connection"); free(ka); return err; } (*sdRef)->kacontext = ka; return kDNSServiceErr_NoError; } #endif /* * Copyright (c) 2003-2020 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of Apple Inc. ("Apple") nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "dnssd_ipc.h" #if APPLE_OSX_mDNSResponder #include "mdns_tlv.h" #endif #if defined(_WIN32) char *win32_strerror(int inErrorCode) { static char buffer[1024]; DWORD n; memset(buffer, 0, sizeof(buffer)); n = FormatMessageA( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, (DWORD) inErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), buffer, sizeof(buffer), NULL); if (n > 0) { // Remove any trailing CR's or LF's since some messages have them. while ((n > 0) && isspace(((unsigned char *) buffer)[n - 1])) buffer[--n] = '\0'; } return buffer; } #endif void put_uint32(const uint32_t l, char **ptr) { (*ptr)[0] = (char)((l >> 24) & 0xFF); (*ptr)[1] = (char)((l >> 16) & 0xFF); (*ptr)[2] = (char)((l >> 8) & 0xFF); (*ptr)[3] = (char)((l ) & 0xFF); *ptr += sizeof(uint32_t); } uint32_t get_uint32(const char **ptr, const char *end) { if (!*ptr || *ptr + sizeof(uint32_t) > end) { *ptr = NULL; return(0); } else { uint8_t *p = (uint8_t*) *ptr; *ptr += sizeof(uint32_t); return((uint32_t) ((uint32_t)p[0] << 24 | (uint32_t)p[1] << 16 | (uint32_t)p[2] << 8 | p[3])); } } void put_uint16(uint16_t s, char **ptr) { (*ptr)[0] = (char)((s >> 8) & 0xFF); (*ptr)[1] = (char)((s ) & 0xFF); *ptr += sizeof(uint16_t); } uint16_t get_uint16(const char **ptr, const char *end) { if (!*ptr || *ptr + sizeof(uint16_t) > end) { *ptr = NULL; return(0); } else { uint8_t *p = (uint8_t*) *ptr; *ptr += sizeof(uint16_t); return((uint16_t) ((uint16_t)p[0] << 8 | p[1])); } } int put_string(const char *str, char **ptr) { size_t len; if (!str) str = ""; len = strlen(str) + 1; memcpy(*ptr, str, len); *ptr += len; return 0; } int get_string(const char **ptr, const char *const end, char *buffer, int buflen) { if (!*ptr) { *buffer = 0; return(-1); } else { char *lim = buffer + buflen; // Calculate limit while (*ptr < end && buffer < lim) { char c = *buffer++ = *(*ptr)++; if (c == 0) return(0); // Success } if (buffer == lim) buffer--; *buffer = 0; // Failed, so terminate string, *ptr = NULL; // clear pointer, return(-1); // and return failure indication } } void put_rdata(const int rdlen, const unsigned char *rdata, char **ptr) { memcpy(*ptr, rdata, rdlen); *ptr += rdlen; } const char *get_rdata(const char **ptr, const char *end, int rdlen) { if (!*ptr || *ptr + rdlen > end) { *ptr = NULL; return(0); } else { const char *rd = *ptr; *ptr += rdlen; return rd; } } #if APPLE_OSX_mDNSResponder size_t get_required_tlv16_length(const uint16_t valuelen) { return mdns_tlv16_get_required_length(valuelen); } void put_tlv16(const uint16_t type, const uint16_t length, const uint8_t *value, char **ptr) { uint8_t *dst = (uint8_t *)*ptr; mdns_tlv16_set(dst, NULL, type, length, value, &dst); *ptr = (char *)dst; } #endif void ConvertHeaderBytes(ipc_msg_hdr *hdr) { hdr->version = htonl(hdr->version); hdr->datalen = htonl(hdr->datalen); hdr->ipc_flags = htonl(hdr->ipc_flags); hdr->op = htonl(hdr->op ); hdr->reg_index = htonl(hdr->reg_index); } /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2003-2020 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of Apple Inc. ("Apple") nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef DNSSD_IPC_H #define DNSSD_IPC_H #include "dns_sd.h" // // Common cross platform services // #if defined(WIN32) # include # define dnssd_InvalidSocket INVALID_SOCKET # define dnssd_SocketValid(s) ((s) != INVALID_SOCKET) # define dnssd_EWOULDBLOCK WSAEWOULDBLOCK # define dnssd_EINTR WSAEINTR # define dnssd_ECONNRESET WSAECONNRESET # define dnssd_socklen_t int # define dnssd_close(sock) closesocket(sock) # define dnssd_errno WSAGetLastError() # define dnssd_strerror(X) win32_strerror(X) # define ssize_t int # define getpid _getpid # define unlink _unlink extern char *win32_strerror(int inErrorCode); #else # include # include # include # include # include # include # include # include # include # include # define dnssd_InvalidSocket -1 # define dnssd_SocketValid(s) ((s) >= 0) # define dnssd_EWOULDBLOCK EWOULDBLOCK # define dnssd_EINTR EINTR # define dnssd_ECONNRESET ECONNRESET # define dnssd_EPIPE EPIPE # define dnssd_socklen_t unsigned int # define dnssd_close(sock) close(sock) # define dnssd_errno errno # define dnssd_strerror(X) strerror(X) #endif #if defined(USE_TCP_LOOPBACK) # define AF_DNSSD AF_INET # define MDNS_TCP_SERVERADDR "127.0.0.1" # define MDNS_TCP_SERVERPORT 5354 # define LISTENQ 5 # define dnssd_sockaddr_t struct sockaddr_in #else # define AF_DNSSD AF_LOCAL # ifndef MDNS_UDS_SERVERPATH # define MDNS_UDS_SERVERPATH "/var/run/mDNSResponder" # endif # define MDNS_UDS_SERVERPATH_ENVVAR "DNSSD_UDS_PATH" # define LISTENQ 100 // longest legal control path length # define MAX_CTLPATH (sizeof(((struct sockaddr_un*)0)->sun_path)) # define dnssd_sockaddr_t struct sockaddr_un #endif // Compatibility workaround #ifndef AF_LOCAL #define AF_LOCAL AF_UNIX #endif // General UDS constants #define TXT_RECORD_INDEX ((uint32_t)(-1)) // record index for default text record // IPC data encoding constants and types #define VERSION 1 #define IPC_FLAGS_NOREPLY (1U << 0) // Set flag if no asynchronous replies are to be sent to client. #define IPC_FLAGS_TRAILING_TLVS (1U << 1) // Set flag if TLVs follow the standard request data. #define IPC_TLV_TYPE_RESOLVER_CONFIG_PLIST_DATA 1 // An nw_resolver_config as a binary property list. #define IPC_TLV_TYPE_REQUIRE_PRIVACY 2 // A uint8. Non-zero means privacy is required, zero means not required. // Structure packing macro. If we're not using GNUC, it's not fatal. Most compilers naturally pack the on-the-wire // structures correctly anyway, so a plain "struct" is usually fine. In the event that structures are not packed // correctly, our compile-time assertion checks will catch it and prevent inadvertent generation of non-working code. #ifndef packedstruct #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9))) #define packedstruct struct __attribute__((__packed__)) #define packedunion union __attribute__((__packed__)) #else #define packedstruct struct #define packedunion union #endif #endif typedef enum { request_op_none = 0, // No request yet received on this connection connection_request = 1, // connected socket via DNSServiceConnect() reg_record_request, // reg/remove record only valid for connected sockets remove_record_request, enumeration_request, reg_service_request, browse_request, resolve_request, query_request, reconfirm_record_request, add_record_request, update_record_request, setdomain_request, // Up to here is in Tiger and B4W 1.0.3 getproperty_request, // New in B4W 1.0.4 port_mapping_request, // New in Leopard and B4W 2.0 addrinfo_request, send_bpf, // New in SL getpid_request, release_request, connection_delegate_request, cancel_request = 63 } request_op_t; typedef enum { enumeration_reply_op = 64, reg_service_reply_op, browse_reply_op, resolve_reply_op, query_reply_op, reg_record_reply_op, // Up to here is in Tiger and B4W 1.0.3 getproperty_reply_op, // New in B4W 1.0.4 port_mapping_reply_op, // New in Leopard and B4W 2.0 addrinfo_reply_op } reply_op_t; #if defined(_WIN64) # pragma pack(push,4) #elif !defined(__GNUC__) # pragma pack(1) #endif // Define context object big enough to hold a 64-bit pointer, // to accomodate 64-bit clients communicating with 32-bit daemon. // There's no reason for the daemon to ever be a 64-bit process, but its clients might be typedef packedunion { void *context; uint32_t u32[2]; } client_context_t; typedef packedstruct { uint32_t version; uint32_t datalen; uint32_t ipc_flags; uint32_t op; // request_op_t or reply_op_t client_context_t client_context; // context passed from client, returned by server in corresponding reply uint32_t reg_index; // identifier for a record registered via DNSServiceRegisterRecord() on a // socket connected by DNSServiceCreateConnection(). Must be unique in the scope of the connection, such that and // index/socket pair uniquely identifies a record. (Used to select records for removal by DNSServiceRemoveRecord()) } ipc_msg_hdr; #if defined(_WIN64) # pragma pack(pop) #elif !defined(__GNUC__) # pragma pack() #endif // routines to write to and extract data from message buffers. // caller responsible for bounds checking. // ptr is the address of the pointer to the start of the field. // it is advanced to point to the next field, or the end of the message void put_uint32(const uint32_t l, char **ptr); uint32_t get_uint32(const char **ptr, const char *end); void put_uint16(uint16_t s, char **ptr); uint16_t get_uint16(const char **ptr, const char *end); #define put_flags put_uint32 #define get_flags get_uint32 #define put_error_code put_uint32 #define get_error_code get_uint32 int put_string(const char *str, char **ptr); int get_string(const char **ptr, const char *const end, char *buffer, int buflen); void put_rdata(const int rdlen, const unsigned char *rdata, char **ptr); const char *get_rdata(const char **ptr, const char *end, int rdlen); // return value is rdata pointed to by *ptr - // rdata is not copied from buffer. #if APPLE_OSX_mDNSResponder size_t get_required_tlv16_length(const uint16_t valuelen); void put_tlv16(const uint16_t type, const uint16_t length, const uint8_t *value, char **ptr); #endif void ConvertHeaderBytes(ipc_msg_hdr *hdr); struct CompileTimeAssertionChecks_dnssd_ipc { // Check that the compiler generated our on-the-wire packet format structure definitions // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries. char assert0[(sizeof(client_context_t) == 8) ? 1 : -1]; char assert1[(sizeof(ipc_msg_hdr) == 28) ? 1 : -1]; }; #endif // DNSSD_IPC_H /* * Copyright (c) 2003-2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #if defined(WIN32) || defined(EFI32) || defined(EFI64) || defined(EFIX64) // Need to add Windows/EFI syslog support here #define LOG_PID 0x01 #define LOG_CONS 0x02 #define LOG_PERROR 0x20 #else #include #endif #include "mDNSEmbeddedAPI.h" mDNSexport int mDNS_LoggingEnabled = 0; mDNSexport int mDNS_PacketLoggingEnabled = 0; mDNSexport int mDNS_McastLoggingEnabled = 0; mDNSexport int mDNS_McastTracingEnabled = 0; #if MDNS_DEBUGMSGS mDNSexport int mDNS_DebugMode = mDNStrue; #else mDNSexport int mDNS_DebugMode = mDNSfalse; #endif // Note, this uses mDNS_vsnprintf instead of standard "vsnprintf", because mDNS_vsnprintf knows // how to print special data types like IP addresses and length-prefixed domain names #if MDNS_DEBUGMSGS > 1 mDNSexport void verbosedebugf_(const char *format, ...) { char buffer[512]; va_list args; va_start(args, format); buffer[mDNS_vsnprintf(buffer, sizeof(buffer), format, args)] = 0; va_end(args); mDNSPlatformWriteDebugMsg(buffer); } #endif // Log message with default "mDNSResponder" ident string at the start #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG) mDNSlocal void LogMsgWithLevelv(os_log_t category, os_log_type_t level, const char *format, va_list args) { char buffer[512]; mDNS_vsnprintf(buffer, (mDNSu32)sizeof(buffer), format, args); os_log_with_type(category ? category : mDNSLogCategory_Default, level, "%{private}s", buffer); } #else mDNSlocal void LogMsgWithLevelv(const char *category, mDNSLogLevel_t level, const char *format, va_list args) { char buffer[512]; char *dst = buffer; const char *const lim = &buffer[512]; if (category) mDNS_snprintf_add(&dst, lim, "%s: ", category); mDNS_vsnprintf(dst, (mDNSu32)(lim - dst), format, args); mDNSPlatformWriteLogMsg(ProgramName, buffer, level); } #endif #define LOG_HELPER_BODY(CATEGORY, LEVEL) \ { \ va_list args; \ va_start(args,format); \ LogMsgWithLevelv(CATEGORY, LEVEL, format, args); \ va_end(args); \ } // see mDNSDebug.h #if !MDNS_HAS_VA_ARG_MACROS void LogMsg_(const char *format, ...) LOG_HELPER_BODY(NULL, MDNS_LOG_INFO) void LogOperation_(const char *format, ...) LOG_HELPER_BODY(NULL, MDNS_LOG_INFO) void LogSPS_(const char *format, ...) LOG_HELPER_BODY(NULL, MDNS_LOG_INFO) void LogInfo_(const char *format, ...) LOG_HELPER_BODY(NULL, MDNS_LOG_INFO) void LogDebug_(const char *format, ...) LOG_HELPER_BODY(NULL, MDNS_LOG_DEBUG) #endif #if MDNS_DEBUGMSGS void debugf_(const char *format, ...) LOG_HELPER_BODY(MDNS_LOG_DEBUG) #endif // Log message with default "mDNSResponder" ident string at the start mDNSexport void LogMsgWithLevel(mDNSLogCategory_t category, mDNSLogLevel_t level, const char *format, ...) LOG_HELPER_BODY(category, level) mDNSexport void LogToFD(int fd, const char *format, ...) { va_list args; va_start(args, format); #if APPLE_OSX_mDNSResponder char buffer[1024]; buffer[mDNS_vsnprintf(buffer, (mDNSu32)sizeof(buffer), format, args)] = '\0'; dprintf(fd, "%s\n", buffer); #else (void)fd; LogMsgWithLevelv(NULL, MDNS_LOG_INFO, format, args); #endif va_end(args); } /* * Copyright (c) 2019 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef __mDNSFeatures_h #define __mDNSFeatures_h #if MDNSRESPONDER_PLATFORM_APPLE #include "ApplePlatformFeatures.h" #endif // Common Features #undef MDNSRESPONDER_PLATFORM_COMMON #define MDNSRESPONDER_PLATFORM_COMMON 1 // Feature: DNS Push // Radar: // Enabled: Yes, for Apple. #if !defined(MDNSRESPONDER_SUPPORTS_COMMON_DNS_PUSH) #if defined(MDNSRESPONDER_PLATFORM_APPLE) && MDNSRESPONDER_PLATFORM_APPLE #define MDNSRESPONDER_SUPPORTS_COMMON_DNS_PUSH 1 #else #define MDNSRESPONDER_SUPPORTS_COMMON_DNS_PUSH 0 #endif #endif #define HAS_FEATURE_CAT(A, B) A ## B #define HAS_FEATURE_CHECK_0 1 #define HAS_FEATURE_CHECK_1 1 #define HAS_FEATURE(X) ((X) / HAS_FEATURE_CAT(HAS_FEATURE_CHECK_, X)) #define MDNSRESPONDER_SUPPORTS(PLATFORM, FEATURE) \ (defined(MDNSRESPONDER_PLATFORM_ ## PLATFORM) && MDNSRESPONDER_PLATFORM_ ## PLATFORM && \ HAS_FEATURE(MDNSRESPONDER_SUPPORTS_ ## PLATFORM ## _ ## FEATURE)) #endif // __mDNSFeatures_h /* * Copyright (c) 2003-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #if defined(_WIN32) #include #define usleep(X) Sleep(((X)+999)/1000) #else #include #include #include #include #include #include #endif #include #include #include "mDNSEmbeddedAPI.h" #include "DNSCommon.h" #include "uDNS.h" #include "uds_daemon.h" #include "dns_sd_internal.h" // Apple-specific functionality, not required for other platforms #if APPLE_OSX_mDNSResponder #include #include #ifndef PID_FILE #define NO_PID_FILE // We need to signal that this platform has no PID file, and not just that we are taking the default #endif #endif #ifdef LOCAL_PEEREPID #include // for LOCAL_PEEREPID #include // for getsockopt #include // for struct proc_bsdshortinfo #include // for proc_pidinfo() #endif //LOCAL_PEEREPID #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) #include "D2D.h" #endif #if APPLE_OSX_mDNSResponder #include "BLE.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) #include "mDNSMacOSX.h" #include #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) #include #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) #include "QuerierSupport.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) && MDNSRESPONDER_SUPPORTS(APPLE, IPC_TLV) #include "mdns_tlv.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) #include "dnssec_v2.h" #endif #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSD_XPC_SERVICE) #include "dnssd_server.h" #endif // User IDs 0-500 are system-wide processes, not actual users in the usual sense // User IDs for real user accounts start at 501 and count up from there #define SystemUID(X) ((X) <= 500) // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Globals #endif // globals mDNSexport mDNS mDNSStorage; mDNSexport const char ProgramName[] = "mDNSResponder"; #if defined(USE_TCP_LOOPBACK) static char* boundPath = NULL; #else static char* boundPath = MDNS_UDS_SERVERPATH; #endif #if DEBUG #define MDNS_UDS_SERVERPATH_DEBUG "/var/tmp/mDNSResponder" #endif static dnssd_sock_t listenfd = dnssd_InvalidSocket; static request_state *all_requests = NULL; #ifdef LOCAL_PEEREPID struct proc_bsdshortinfo proc; #endif //LOCAL_PEEREPID mDNSlocal void set_peer_pid(request_state *request); mDNSlocal void LogMcastClientInfo(request_state *req); mDNSlocal void GetMcastClients(request_state *req); static mDNSu32 mcount; // tracks the current active mcast operations for McastLogging static mDNSu32 i_mcount; // sets mcount when McastLogging is enabled(PROF signal is sent) static mDNSu32 n_mrecords; // tracks the current active mcast records for McastLogging static mDNSu32 n_mquests; // tracks the current active mcast questions for McastLogging #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) mDNSu32 curr_num_regservices = 0; mDNSu32 max_num_regservices = 0; #endif // Note asymmetry here between registration and browsing. // For service registrations we only automatically register in domains that explicitly appear in local configuration data // (so AutoRegistrationDomains could equally well be called SCPrefRegDomains) // For service browsing we also learn automatic browsing domains from the network, so for that case we have: // 1. SCPrefBrowseDomains (local configuration data) // 2. LocalDomainEnumRecords (locally-generated local-only PTR records -- equivalent to slElem->AuthRecs in uDNS.c) // 3. AutoBrowseDomains, which is populated by tracking add/rmv events in AutomaticBrowseDomainChange, the callback function for our mDNS_GetDomains call. // By creating and removing our own LocalDomainEnumRecords, we trigger AutomaticBrowseDomainChange callbacks just like domains learned from the network would. mDNSexport DNameListElem *AutoRegistrationDomains; // Domains where we automatically register for empty-string registrations static DNameListElem *SCPrefBrowseDomains; // List of automatic browsing domains read from SCPreferences for "empty string" browsing static ARListElem *LocalDomainEnumRecords; // List of locally-generated PTR records to augment those we learn from the network mDNSexport DNameListElem *AutoBrowseDomains; // List created from those local-only PTR records plus records we get from the network #define MSG_PAD_BYTES 5 // pad message buffer (read from client) with n zero'd bytes to guarantee // n get_string() calls w/o buffer overrun // initialization, setup/teardown functions // If a platform specifies its own PID file name, we use that #ifndef PID_FILE #define PID_FILE "/var/run/mDNSResponder.pid" #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - General Utility Functions #endif mDNSlocal mDNSu32 GetNewRequestID(void) { #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSD_XPC_SERVICE) return dnssd_server_get_new_request_id(); #else static mDNSu32 s_last_id = 0; return ++s_last_id; #endif } mDNSlocal void FatalError(char *errmsg) { LogMsg("%s: %s", errmsg, dnssd_strerror(dnssd_errno)); abort(); } mDNSlocal mDNSu32 dnssd_htonl(mDNSu32 l) { mDNSu32 ret; char *data = (char*) &ret; put_uint32(l, &data); return ret; } // hack to search-replace perror's to LogMsg's mDNSlocal void my_perror(char *errmsg) { LogMsg("%s: %d (%s)", errmsg, dnssd_errno, dnssd_strerror(dnssd_errno)); } // Throttled version of my_perror: Logs once every 250 msgs mDNSlocal void my_throttled_perror(char *err_msg) { static int uds_throttle_count = 0; if ((uds_throttle_count++ % 250) == 0) my_perror(err_msg); } // LogMcastQuestion/LogMcastQ should be called after the DNSQuestion struct is initialized(especially for q->TargetQID) // Hence all calls are made after mDNS_StartQuery()/mDNS_StopQuery()/mDNS_StopBrowse() is called. mDNSlocal void LogMcastQuestion(const DNSQuestion *const q, request_state *req, q_state status) { if (mDNSOpaque16IsZero(q->TargetQID)) // Check for Mcast Query { mDNSBool mflag = mDNSfalse; if (status == q_start) { if (++mcount == 1) mflag = mDNStrue; } else { mcount--; } LogMcast("%s: %##s (%s) (%s) Client(%d)[%s]", status ? "+Question" : "-Question", q->qname.c, DNSTypeName(q->qtype), q->InterfaceID == mDNSInterface_LocalOnly ? "lo" : q->InterfaceID == mDNSInterface_P2P ? "p2p" : q->InterfaceID == mDNSInterface_BLE ? "BLE" : q->InterfaceID == mDNSInterface_Any ? "any" : InterfaceNameForID(&mDNSStorage, q->InterfaceID), req->process_id, req->pid_name); LogMcastStateInfo(mflag, mDNSfalse, mDNSfalse); } return; } // LogMcastService/LogMcastS should be called after the AuthRecord struct is initialized // Hence all calls are made after mDNS_Register()/ just before mDNS_Deregister() mDNSlocal void LogMcastService(const AuthRecord *const ar, request_state *req, reg_state status) { if (!AuthRecord_uDNS(ar)) // Check for Mcast Service { mDNSBool mflag = mDNSfalse; if (status == reg_start) { if (++mcount == 1) mflag = mDNStrue; } else { mcount--; } LogMcast("%s: %##s (%s) (%s) Client(%d)[%s]", status ? "+Service" : "-Service", ar->resrec.name->c, DNSTypeName(ar->resrec.rrtype), ar->resrec.InterfaceID == mDNSInterface_LocalOnly ? "lo" : ar->resrec.InterfaceID == mDNSInterface_P2P ? "p2p" : ar->resrec.InterfaceID == mDNSInterface_BLE ? "BLE" : ar->resrec.InterfaceID == mDNSInterface_Any ? "all" : InterfaceNameForID(&mDNSStorage, ar->resrec.InterfaceID), req->process_id, req->pid_name); LogMcastStateInfo(mflag, mDNSfalse, mDNSfalse); } return; } // For complete Mcast State Log, pass mDNStrue to mstatelog in LogMcastStateInfo() mDNSexport void LogMcastStateInfo(mDNSBool mflag, mDNSBool start, mDNSBool mstatelog) { mDNS *const m = &mDNSStorage; if (!mstatelog) { if (!all_requests) { LogMcastNoIdent(""); } else { request_state *req, *r; for (req = all_requests; req; req=req->next) { if (req->primary) // If this is a subbordinate operation, check that the parent is in the list { for (r = all_requests; r && r != req; r=r->next) if (r == req->primary) goto foundpar; } // For non-subbordinate operations, and subbordinate operations that have lost their parent, write out their info GetMcastClients(req); foundpar:; } LogMcastNoIdent("--- MCAST RECORDS COUNT[%d] MCAST QUESTIONS COUNT[%d] ---", n_mrecords, n_mquests); n_mrecords = n_mquests = 0; // Reset the values } } else { static mDNSu32 i_mpktnum; i_mcount = 0; if (start) mcount = 0; // mcount is initialized to 0 when the PROF signal is sent since mcount could have // wrong value if MulticastLogging is disabled and then re-enabled LogMcastNoIdent("--- START MCAST STATE LOG ---"); if (!all_requests) { mcount = 0; LogMcastNoIdent(""); } else { request_state *req, *r; for (req = all_requests; req; req=req->next) { if (req->primary) // If this is a subbordinate operation, check that the parent is in the list { for (r = all_requests; r && r != req; r=r->next) if (r == req->primary) goto foundparent; LogMcastNoIdent("%3d: Orphan operation; parent not found in request list", req->sd); } // For non-subbordinate operations, and subbordinate operations that have lost their parent, write out their info LogMcastClientInfo(req); foundparent:; } if(!mcount) // To initially set mcount mcount = i_mcount; } if (mcount == 0) { i_mpktnum = m->MPktNum; LogMcastNoIdent("--- MCOUNT[%d]: IMPKTNUM[%d] ---", mcount, i_mpktnum); } if (mflag) LogMcastNoIdent("--- MCOUNT[%d]: CMPKTNUM[%d] - IMPKTNUM[%d] = [%d]PKTS ---", mcount, m->MPktNum, i_mpktnum, (m->MPktNum - i_mpktnum)); LogMcastNoIdent("--- END MCAST STATE LOG ---"); } } mDNSlocal void abort_request(request_state *req) { if (req->terminate == (req_termination_fn) ~0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] abort_request: ERROR: Attempt to abort operation %p with req->terminate %p", req->request_id, req, req->terminate); return; } // First stop whatever mDNSCore operation we were doing // If this is actually a shared connection operation, then its req->terminate function will scan // the all_requests list and terminate any subbordinate operations sharing this file descriptor if (req->terminate) req->terminate(req); #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (req->custom_service_id != 0) { Querier_DeregisterCustomDNSService(req->custom_service_id); req->custom_service_id = 0; } #endif if (!dnssd_SocketValid(req->sd)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] abort_request: ERROR: Attempt to abort operation %p with invalid fd %d", req->request_id, req, req->sd); return; } // Now, if this request_state is not subordinate to some other primary, close file descriptor and discard replies if (!req->primary) { if (req->errsd != req->sd) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%d] Removing FD %d and closing errsd %d", req->request_id, req->sd, req->errsd); } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%d] Removing FD %d", req->request_id, req->sd); } udsSupportRemoveFDFromEventLoop(req->sd, req->platform_data); // Note: This also closes file descriptor req->sd for us if (req->errsd != req->sd) { dnssd_close(req->errsd); req->errsd = req->sd; } while (req->replies) // free pending replies { reply_state *ptr = req->replies; req->replies = req->replies->next; freeL("reply_state (abort)", ptr); } } // Set req->sd to something invalid, so that udsserver_idle knows to unlink and free this structure #if MDNS_MALLOC_DEBUGGING // Don't use dnssd_InvalidSocket (-1) because that's the sentinel value MDNS_MALLOC_DEBUGGING uses // for detecting when the memory for an object is inadvertently freed while the object is still on some list #ifdef WIN32 #error This will not work on Windows, look at IsValidSocket in mDNSShared/CommonServices.h to see why #endif req->sd = req->errsd = -2; #else req->sd = req->errsd = dnssd_InvalidSocket; #endif // We also set req->terminate to a bogus value so we know if abort_request() gets called again for this request req->terminate = (req_termination_fn) ~0; } #if DEBUG mDNSexport void SetDebugBoundPath(void) { #if !defined(USE_TCP_LOOPBACK) boundPath = MDNS_UDS_SERVERPATH_DEBUG; #endif } mDNSexport int IsDebugSocketInUse(void) { #if !defined(USE_TCP_LOOPBACK) return !strcmp(boundPath, MDNS_UDS_SERVERPATH_DEBUG); #else return mDNSfalse; #endif } #endif mDNSlocal void AbortUnlinkAndFree(request_state *req) { request_state **p = &all_requests; abort_request(req); while (*p && *p != req) p=&(*p)->next; if (*p) { *p = req->next; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (req->trust) { void * context = mdns_trust_get_context(req->trust); mdns_trust_set_context(req->trust, NULL); if (context) freeL("context/AbortUnlinkAndFree", context); mdns_trust_forget(&req->trust); } #endif freeL("request_state/AbortUnlinkAndFree", req); } else LogMsg("AbortUnlinkAndFree: ERROR: Attempt to abort operation %p not in list", req); } mDNSlocal reply_state *create_reply(const reply_op_t op, const size_t datalen, request_state *const request) { reply_state *reply; if ((unsigned)datalen < sizeof(reply_hdr)) { LogMsg("ERROR: create_reply - data length less than length of required fields"); return NULL; } reply = (reply_state *) callocL("reply_state", sizeof(reply_state) + datalen - sizeof(reply_hdr)); if (!reply) FatalError("ERROR: calloc"); reply->next = mDNSNULL; reply->totallen = (mDNSu32)datalen + sizeof(ipc_msg_hdr); reply->nwriten = 0; reply->mhdr->version = VERSION; reply->mhdr->datalen = (mDNSu32)datalen; reply->mhdr->ipc_flags = 0; reply->mhdr->op = op; reply->mhdr->client_context = request->hdr.client_context; reply->mhdr->reg_index = 0; return reply; } // Append a reply to the list in a request object // If our request is sharing a connection, then we append our reply_state onto the primary's list // If the request does not want asynchronous replies, then the reply is freed instead of being appended to any list. mDNSlocal void append_reply(request_state *req, reply_state *rep) { request_state *r; reply_state **ptr; if (req->no_reply) { freeL("reply_state/append_reply", rep); return; } r = req->primary ? req->primary : req; ptr = &r->replies; while (*ptr) ptr = &(*ptr)->next; *ptr = rep; rep->next = NULL; } // Generates a response message giving name, type, domain, plus interface index, // suitable for a browse result or service registration result. // On successful completion rep is set to point to a malloc'd reply_state struct mDNSlocal mStatus GenerateNTDResponse(const domainname *const servicename, const mDNSInterfaceID id, request_state *const request, reply_state **const rep, reply_op_t op, DNSServiceFlags flags, mStatus err) { domainlabel name; domainname type, dom; *rep = NULL; if (servicename && !DeconstructServiceName(servicename, &name, &type, &dom)) return kDNSServiceErr_Invalid; else { char namestr[MAX_DOMAIN_LABEL+1]; char typestr[MAX_ESCAPED_DOMAIN_NAME]; char domstr [MAX_ESCAPED_DOMAIN_NAME]; int len; char *data; if (servicename) { ConvertDomainLabelToCString_unescaped(&name, namestr); ConvertDomainNameToCString(&type, typestr); ConvertDomainNameToCString(&dom, domstr); } else { namestr[0] = 0; typestr[0] = 0; domstr[0] = 0; } // Calculate reply data length len = sizeof(DNSServiceFlags); len += sizeof(mDNSu32); // if index len += sizeof(DNSServiceErrorType); len += (int) (strlen(namestr) + 1); len += (int) (strlen(typestr) + 1); len += (int) (strlen(domstr) + 1); // Build reply header *rep = create_reply(op, len, request); (*rep)->rhdr->flags = dnssd_htonl(flags); (*rep)->rhdr->ifi = dnssd_htonl(mDNSPlatformInterfaceIndexfromInterfaceID(&mDNSStorage, id, mDNSfalse)); (*rep)->rhdr->error = dnssd_htonl(err); // Build reply body data = (char *)&(*rep)->rhdr[1]; put_string(namestr, &data); put_string(typestr, &data); put_string(domstr, &data); return mStatus_NoError; } } mDNSlocal void GenerateBrowseReply(const domainname *const servicename, const mDNSInterfaceID id, request_state *const request, reply_state **const rep, reply_op_t op, DNSServiceFlags flags, mStatus err) { char namestr[MAX_DOMAIN_LABEL+1]; char typestr[MAX_ESCAPED_DOMAIN_NAME]; static const char domstr[] = "."; int len; char *data; *rep = NULL; if (servicename) { // 1. Put first label in namestr ConvertDomainLabelToCString_unescaped((const domainlabel *)servicename, namestr); // 2. Put second label and "local" into typestr mDNS_snprintf(typestr, sizeof(typestr), "%#s.local.", SecondLabel(servicename)); } else { namestr[0] = 0; typestr[0] = 0; } // Calculate reply data length len = sizeof(DNSServiceFlags); len += sizeof(mDNSu32); // if index len += sizeof(DNSServiceErrorType); len += (int) (strlen(namestr) + 1); len += (int) (strlen(typestr) + 1); len += (int) (strlen(domstr) + 1); // Build reply header *rep = create_reply(op, len, request); (*rep)->rhdr->flags = dnssd_htonl(flags); (*rep)->rhdr->ifi = dnssd_htonl(mDNSPlatformInterfaceIndexfromInterfaceID(&mDNSStorage, id, mDNSfalse)); (*rep)->rhdr->error = dnssd_htonl(err); // Build reply body data = (char *)&(*rep)->rhdr[1]; put_string(namestr, &data); put_string(typestr, &data); put_string(domstr, &data); } // Returns a resource record (allocated w/ malloc) containing the data found in an IPC message // Data must be in the following format: flags, interfaceIndex, name, rrtype, rrclass, rdlen, rdata, (optional) ttl // (ttl only extracted/set if ttl argument is non-zero). Returns NULL for a bad-parameter error mDNSlocal AuthRecord *read_rr_from_ipc_msg(request_state *request, int GetTTL, int validate_flags) { DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); mDNSu32 interfaceIndex = get_uint32(&request->msgptr, request->msgend); char name[MAX_ESCAPED_DOMAIN_NAME]; int str_err = get_string(&request->msgptr, request->msgend, name, sizeof(name)); mDNSu16 type = get_uint16(&request->msgptr, request->msgend); mDNSu16 class = get_uint16(&request->msgptr, request->msgend); mDNSu16 rdlen = get_uint16(&request->msgptr, request->msgend); const mDNSu8 *const rdata = (const mDNSu8 *)get_rdata (&request->msgptr, request->msgend, rdlen); mDNSu32 ttl = GetTTL ? get_uint32(&request->msgptr, request->msgend) : 0; size_t rdcapacity; AuthRecord *rr; mDNSInterfaceID InterfaceID; AuthRecType artype; mDNSu8 recordType; request->flags = flags; request->interfaceIndex = interfaceIndex; if (str_err) { LogMsg("ERROR: read_rr_from_ipc_msg - get_string"); return NULL; } if (!request->msgptr) { LogMsg("Error reading Resource Record from client"); return NULL; } if (validate_flags && !((flags & kDNSServiceFlagsShared) == kDNSServiceFlagsShared) && !((flags & kDNSServiceFlagsUnique) == kDNSServiceFlagsUnique) && !((flags & kDNSServiceFlagsKnownUnique) == kDNSServiceFlagsKnownUnique)) { LogMsg("ERROR: Bad resource record flags (must be one of either kDNSServiceFlagsShared, kDNSServiceFlagsUnique or kDNSServiceFlagsKnownUnique)"); return NULL; } InterfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, interfaceIndex); // The registration is scoped to a specific interface index, but the interface is not currently on our list. if ((InterfaceID == mDNSInterface_Any) && (interfaceIndex != kDNSServiceInterfaceIndexAny)) { // On Apple platforms, an interface's mDNSInterfaceID is equal to its index. Using an interface index that isn't // currently valid will cause the registration to take place as soon as it becomes valid. On other platforms, // mDNSInterfaceID is actually a pointer to a platform-specific interface object, but we don't know what the pointer // for the interface index will be ahead of time. For now, just return NULL to indicate an error condition since the // interface index is invalid. Otherwise, the registration would be performed on all interfaces. #if APPLE_OSX_mDNSResponder InterfaceID = (mDNSInterfaceID)(uintptr_t)interfaceIndex; #else return NULL; #endif } rdcapacity = (rdlen > sizeof(RDataBody2)) ? rdlen : sizeof(RDataBody2); rr = (AuthRecord *) callocL("AuthRecord/read_rr_from_ipc_msg", sizeof(*rr) - sizeof(RDataBody) + rdcapacity); if (!rr) FatalError("ERROR: calloc"); if (InterfaceID == mDNSInterface_LocalOnly) artype = AuthRecordLocalOnly; else if (InterfaceID == mDNSInterface_P2P || InterfaceID == mDNSInterface_BLE) artype = AuthRecordP2P; else if ((InterfaceID == mDNSInterface_Any) && (flags & kDNSServiceFlagsIncludeP2P) && (flags & kDNSServiceFlagsIncludeAWDL)) artype = AuthRecordAnyIncludeAWDLandP2P; else if ((InterfaceID == mDNSInterface_Any) && (flags & kDNSServiceFlagsIncludeP2P)) artype = AuthRecordAnyIncludeP2P; else if ((InterfaceID == mDNSInterface_Any) && (flags & kDNSServiceFlagsIncludeAWDL)) artype = AuthRecordAnyIncludeAWDL; else artype = AuthRecordAny; if (flags & kDNSServiceFlagsShared) recordType = (mDNSu8) kDNSRecordTypeShared; else if (flags & kDNSServiceFlagsKnownUnique) recordType = (mDNSu8) kDNSRecordTypeKnownUnique; else recordType = (mDNSu8) kDNSRecordTypeUnique; mDNS_SetupResourceRecord(rr, mDNSNULL, InterfaceID, type, 0, recordType, artype, mDNSNULL, mDNSNULL); if (!MakeDomainNameFromDNSNameString(&rr->namestorage, name)) { LogMsg("ERROR: bad name: %s", name); freeL("AuthRecord/read_rr_from_ipc_msg", rr); return NULL; } if (flags & kDNSServiceFlagsAllowRemoteQuery) rr->AllowRemoteQuery = mDNStrue; rr->resrec.rrclass = class; rr->resrec.rdlength = rdlen; rr->resrec.rdata->MaxRDLength = (mDNSu16)rdcapacity; if (!SetRData(mDNSNULL, rdata, rdata + rdlen, &rr->resrec, rdlen)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] read_rr_from_ipc_msg: SetRData failed for " PRI_DM_NAME " (" PUB_S ")", request->request_id, DM_NAME_PARAM(rr->resrec.name), DNSTypeName(type)); freeL("AuthRecord/read_rr_from_ipc_msg", rr); return NULL; } if (GetTTL) rr->resrec.rroriginalttl = ttl; rr->resrec.namehash = DomainNameHashValue(rr->resrec.name); SetNewRData(&rr->resrec, mDNSNULL, 0); // Sets rr->rdatahash for us return rr; } mDNSlocal int build_domainname_from_strings(domainname *srv, char *name, char *regtype, char *domain) { domainlabel n; domainname d, t; if (!MakeDomainLabelFromLiteralString(&n, name)) return -1; if (!MakeDomainNameFromDNSNameString(&t, regtype)) return -1; if (!MakeDomainNameFromDNSNameString(&d, domain)) return -1; if (!ConstructServiceName(srv, &n, &t, &d)) return -1; return 0; } mDNSlocal void send_all(dnssd_sock_t s, const char *ptr, int len) { const ssize_t n = send(s, ptr, len, 0); // On a freshly-created Unix Domain Socket, the kernel should *never* fail to buffer a small write for us // (four bytes for a typical error code return, 12 bytes for DNSServiceGetProperty(DaemonVersion)). // If it does fail, we don't attempt to handle this failure, but we do log it so we know something is wrong. if (n < len) { LogMsg("ERROR: send_all(%d) wrote %ld of %d errno %d (%s)", s, (long)n, len, dnssd_errno, dnssd_strerror(dnssd_errno)); } } #if 0 mDNSlocal mDNSBool AuthorizedDomain(const request_state * const request, const domainname * const d, const DNameListElem * const doms) { const DNameListElem *delem = mDNSNULL; int bestDelta = -1; // the delta of the best match, lower is better int dLabels = 0; mDNSBool allow = mDNSfalse; if (SystemUID(request->uid)) return mDNStrue; dLabels = CountLabels(d); for (delem = doms; delem; delem = delem->next) { if (delem->uid) { int delemLabels = CountLabels(&delem->name); int delta = dLabels - delemLabels; if ((bestDelta == -1 || delta <= bestDelta) && SameDomainName(&delem->name, SkipLeadingLabels(d, delta))) { bestDelta = delta; allow = (allow || (delem->uid == request->uid)); } } } return bestDelta == -1 ? mDNStrue : allow; } #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) mDNSlocal void SetupAuditTokenForRequest(request_state *request) { pid_t audit_pid = audit_token_to_pid(request->audit_token); if (audit_pid == 0) { #if !defined(LOCAL_PEERTOKEN) #define LOCAL_PEERTOKEN 0x006 /* retrieve peer audit token */ #endif socklen_t len = sizeof(audit_token_t); int ret = getsockopt(request->sd, SOL_LOCAL, LOCAL_PEERTOKEN, &request->audit_token, &len); if (ret != 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "SetupAuditTokenForRequest: No audit_token using LOCAL_PEERTOKEN (%s PID %d) for op %d ret(%d)", request->pid_name, request->process_id, request->hdr.op, ret); } } } #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - external helpers #endif #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) mDNSlocal void external_start_advertising_helper(service_instance *const instance) { AuthRecord *st = instance->subtypes; ExtraResourceRecord *e; int i; const pid_t requestPID = instance->request->process_id; if (mDNSIPPortIsZero(instance->request->u.servicereg.port)) { LogInfo("external_start_advertising_helper: Not registering service with port number zero"); return; } if (instance->external_advertise) LogMsg("external_start_advertising_helper: external_advertise already set!"); for ( i = 0; i < instance->request->u.servicereg.num_subtypes; i++) external_start_advertising_service(&st[i].resrec, instance->request->flags, requestPID); external_start_advertising_service(&instance->srs.RR_PTR.resrec, instance->request->flags, requestPID); external_start_advertising_service(&instance->srs.RR_SRV.resrec, instance->request->flags, requestPID); external_start_advertising_service(&instance->srs.RR_TXT.resrec, instance->request->flags, requestPID); for (e = instance->srs.Extras; e; e = e->next) external_start_advertising_service(&e->r.resrec, instance->request->flags, requestPID); instance->external_advertise = mDNStrue; } mDNSlocal void external_stop_advertising_helper(service_instance *const instance) { AuthRecord *st = instance->subtypes; ExtraResourceRecord *e; int i; if (!instance->external_advertise) return; LogInfo("external_stop_advertising_helper: calling external_stop_advertising_service"); if (instance->request) { const pid_t requestPID = instance->request->process_id; for (i = 0; i < instance->request->u.servicereg.num_subtypes; i++) { external_stop_advertising_service(&st[i].resrec, instance->request->flags, requestPID); } external_stop_advertising_service(&instance->srs.RR_PTR.resrec, instance->request->flags, requestPID); external_stop_advertising_service(&instance->srs.RR_SRV.resrec, instance->request->flags, requestPID); external_stop_advertising_service(&instance->srs.RR_TXT.resrec, instance->request->flags, requestPID); for (e = instance->srs.Extras; e; e = e->next) { external_stop_advertising_service(&e->r.resrec, instance->request->flags, requestPID); } } instance->external_advertise = mDNSfalse; } #endif // MDNSRESPONDER_SUPPORTS(APPLE, D2D) #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal dispatch_queue_t _get_trust_results_dispatch_queue(void) { static dispatch_once_t once = 0; static dispatch_queue_t queue = NULL; dispatch_once(&once, ^{ dispatch_queue_attr_t const attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_UTILITY, 0); queue = dispatch_queue_create("com.apple.mDNSResponder.trust_results-queue", attr); }); return queue; } #endif // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceRegister #endif mDNSexport void FreeExtraRR(mDNS *const m, AuthRecord *const rr, mStatus result) { ExtraResourceRecord *extra = (ExtraResourceRecord *)rr->RecordContext; (void)m; // Unused if (result != mStatus_MemFree) { LogMsg("Error: FreeExtraRR invoked with unexpected error %d", result); return; } LogInfo(" FreeExtraRR %s", RRDisplayString(m, &rr->resrec)); if (rr->resrec.rdata != &rr->rdatastorage) freeL("Extra RData", rr->resrec.rdata); freeL("ExtraResourceRecord/FreeExtraRR", extra); } mDNSlocal void unlink_and_free_service_instance(service_instance *srv) { ExtraResourceRecord *e = srv->srs.Extras, *tmp; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_helper(srv); #endif // clear pointers from parent struct if (srv->request) { service_instance **p = &srv->request->u.servicereg.instances; while (*p) { if (*p == srv) { *p = (*p)->next; break; } p = &(*p)->next; } } while (e) { e->r.RecordContext = e; tmp = e; e = e->next; FreeExtraRR(&mDNSStorage, &tmp->r, mStatus_MemFree); } if (srv->srs.RR_TXT.resrec.rdata != &srv->srs.RR_TXT.rdatastorage) freeL("TXT RData", srv->srs.RR_TXT.resrec.rdata); if (srv->subtypes) { freeL("ServiceSubTypes", srv->subtypes); srv->subtypes = NULL; } freeL("service_instance", srv); } // Count how many other service records we have locally with the same name, but different rdata. // For auto-named services, we can have at most one per machine -- if we allowed two auto-named services of // the same type on the same machine, we'd get into an infinite autoimmune-response loop of continuous renaming. mDNSexport int CountPeerRegistrations(ServiceRecordSet *const srs) { int count = 0; ResourceRecord *r = &srs->RR_SRV.resrec; AuthRecord *rr; for (rr = mDNSStorage.ResourceRecords; rr; rr=rr->next) if (rr->resrec.rrtype == kDNSType_SRV && SameDomainName(rr->resrec.name, r->name) && !IdenticalSameNameRecord(&rr->resrec, r)) count++; verbosedebugf("%d peer registrations for %##s", count, r->name->c); return(count); } mDNSexport int CountExistingRegistrations(domainname *srv, mDNSIPPort port) { int count = 0; AuthRecord *rr; for (rr = mDNSStorage.ResourceRecords; rr; rr=rr->next) if (rr->resrec.rrtype == kDNSType_SRV && mDNSSameIPPort(rr->resrec.rdata->u.srv.port, port) && SameDomainName(rr->resrec.name, srv)) count++; return(count); } mDNSlocal void SendServiceRemovalNotification(ServiceRecordSet *const srs) { reply_state *rep; service_instance *instance = srs->ServiceContext; if (GenerateNTDResponse(srs->RR_SRV.resrec.name, srs->RR_SRV.resrec.InterfaceID, instance->request, &rep, reg_service_reply_op, 0, mStatus_NoError) != mStatus_NoError) LogMsg("%3d: SendServiceRemovalNotification: %##s is not valid DNS-SD SRV name", instance->request->sd, srs->RR_SRV.resrec.name->c); else { append_reply(instance->request, rep); instance->clientnotified = mDNSfalse; } } // service registration callback performs three duties - frees memory for deregistered services, // handles name conflicts, and delivers completed registration information to the client mDNSlocal void regservice_callback(mDNS *const m, ServiceRecordSet *const srs, mStatus result) { mStatus err; mDNSBool SuppressError = mDNSfalse; service_instance *instance; reply_state *rep; (void)m; // Unused if (!srs) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "regservice_callback: srs is NULL %d", result); return; } instance = srs->ServiceContext; if (!instance) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "regservice_callback: srs->ServiceContext is NULL %d", result); return; } // don't send errors up to client for wide-area, empty-string registrations if (instance->request && instance->request->u.servicereg.default_domain && !instance->default_local) SuppressError = mDNStrue; if (mDNS_LoggingEnabled) { const char *result_description; char description[32]; // 32-byte is enough for holding "suppressed error -2147483648\0" mDNSu32 request_id = instance->request ? instance->request->request_id : 0; switch (result) { case mStatus_NoError: result_description = "REGISTERED"; break; case mStatus_MemFree: result_description = "DEREGISTERED"; break; case mStatus_NameConflict: result_description = "NAME CONFLICT"; break; default: mDNS_snprintf(description, sizeof(description), "%s %d", SuppressError ? "suppressed error" : "CALLBACK", result); result_description = description; break; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSServiceRegister(" PRI_DM_NAME ", %u) %s", request_id, DM_NAME_PARAM(srs->RR_SRV.resrec.name), mDNSVal16(srs->RR_SRV.resrec.rdata->u.srv.port), result_description); } if (!instance->request && result != mStatus_MemFree) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "regservice_callback: instance->request is NULL %d", result); return; } if (result == mStatus_NoError) { if (instance->request->u.servicereg.allowremotequery) { ExtraResourceRecord *e; srs->RR_ADV.AllowRemoteQuery = mDNStrue; srs->RR_PTR.AllowRemoteQuery = mDNStrue; srs->RR_SRV.AllowRemoteQuery = mDNStrue; srs->RR_TXT.AllowRemoteQuery = mDNStrue; for (e = instance->srs.Extras; e; e = e->next) e->r.AllowRemoteQuery = mDNStrue; } if (GenerateNTDResponse(srs->RR_SRV.resrec.name, srs->RR_SRV.resrec.InterfaceID, instance->request, &rep, reg_service_reply_op, kDNSServiceFlagsAdd, result) != mStatus_NoError) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] regservice_callback: " PRI_DM_NAME " is not valid DNS-SD SRV name", instance->request->request_id, DM_NAME_PARAM(srs->RR_SRV.resrec.name)); else { append_reply(instance->request, rep); instance->clientnotified = mDNStrue; } #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(instance->request->u.servicereg.InterfaceID, &instance->domain, instance->request->flags)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] regservice_callback: calling external_start_advertising_helper()", instance->request->request_id); external_start_advertising_helper(instance); } #endif if (instance->request->u.servicereg.autoname && CountPeerRegistrations(srs) == 0) RecordUpdatedNiceLabel(0); // Successfully got new name, tell user immediately } else if (result == mStatus_MemFree) { #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) curr_num_regservices--; #endif if (instance->request && instance->renameonmemfree) { #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_helper(instance); #endif instance->renameonmemfree = 0; err = mDNS_RenameAndReregisterService(m, srs, &instance->request->u.servicereg.name); if (err) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] ERROR: regservice_callback - RenameAndReregisterService returned %d", instance->request->request_id, err); // error should never happen - safest to log and continue } else unlink_and_free_service_instance(instance); } else if (result == mStatus_NameConflict) { if (instance->request->u.servicereg.autorename) { #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_helper(instance); #endif if (instance->request->u.servicereg.autoname && CountPeerRegistrations(srs) == 0) { // On conflict for an autoname service, rename and reregister *all* autoname services IncrementLabelSuffix(&m->nicelabel, mDNStrue); mDNS_ConfigChanged(m); // Will call back into udsserver_handle_configchange() } else // On conflict for a non-autoname service, rename and reregister just that one service { if (instance->clientnotified) SendServiceRemovalNotification(srs); mDNS_RenameAndReregisterService(m, srs, mDNSNULL); } } else { if (!SuppressError) { if (GenerateNTDResponse(srs->RR_SRV.resrec.name, srs->RR_SRV.resrec.InterfaceID, instance->request, &rep, reg_service_reply_op, kDNSServiceFlagsAdd, result) != mStatus_NoError) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] regservice_callback: " PRI_DM_NAME " is not valid DNS-SD SRV name", instance->request->request_id, DM_NAME_PARAM(srs->RR_SRV.resrec.name)); else { append_reply(instance->request, rep); instance->clientnotified = mDNStrue; } } unlink_and_free_service_instance(instance); } } else // Not mStatus_NoError, mStatus_MemFree, or mStatus_NameConflict { if (!SuppressError) { if (GenerateNTDResponse(srs->RR_SRV.resrec.name, srs->RR_SRV.resrec.InterfaceID, instance->request, &rep, reg_service_reply_op, kDNSServiceFlagsAdd, result) != mStatus_NoError) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] regservice_callback: " PRI_DM_NAME " is not valid DNS-SD SRV name", instance->request->request_id, DM_NAME_PARAM(srs->RR_SRV.resrec.name)); else { append_reply(instance->request, rep); instance->clientnotified = mDNStrue; } } } } mDNSlocal void regrecord_callback(mDNS *const m, AuthRecord *rr, mStatus result) { (void)m; // Unused if (!rr->RecordContext) // parent struct already freed by termination callback { if (result == mStatus_NoError) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "Error: regrecord_callback: successful registration of orphaned record " PRI_S, ARDisplayString(m, rr)); else { if (result != mStatus_MemFree) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "regrecord_callback: error %d received after parent termination", result); // We come here when the record is being deregistered either from DNSServiceRemoveRecord or connection_termination. // If the record has been updated, we need to free the rdata. Every time we call mDNS_Update, it calls update_callback // with the old rdata (so that we can free it) and stores the new rdata in "rr->resrec.rdata". This means, we need // to free the latest rdata for which the update_callback was never called with. if (rr->resrec.rdata != &rr->rdatastorage) freeL("RData/regrecord_callback", rr->resrec.rdata); freeL("AuthRecord/regrecord_callback", rr); } } else { registered_record_entry *re = rr->RecordContext; request_state *request = re->request; if (mDNS_LoggingEnabled) { const char *result_description; char description[16]; // 16-byte is enough for holding -2147483648\0 switch (result) { case mStatus_NoError: result_description = "REGISTERED"; break; case mStatus_MemFree: result_description = "DEREGISTERED"; break; case mStatus_NameConflict: result_description = "NAME CONFLICT"; break; default: mDNS_snprintf(description, sizeof(description), "%d", result); result_description = description; break; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSServiceRegisterRecord(%u " PRI_S ")" PUB_S, request->request_id, re->key, RRDisplayString(m, &rr->resrec), result_description); } if (result != mStatus_MemFree) { int len = sizeof(DNSServiceFlags) + sizeof(mDNSu32) + sizeof(DNSServiceErrorType); reply_state *reply = create_reply(reg_record_reply_op, len, request); reply->mhdr->client_context = re->regrec_client_context; reply->rhdr->flags = dnssd_htonl(0); reply->rhdr->ifi = dnssd_htonl(mDNSPlatformInterfaceIndexfromInterfaceID(m, rr->resrec.InterfaceID, mDNSfalse)); reply->rhdr->error = dnssd_htonl(result); append_reply(request, reply); } if (result) { // If this is a callback to a keepalive record, do not free it. if (result == mStatus_BadStateErr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] regrecord_callback: Callback with error code mStatus_BadStateErr - not freeing the record.", request->request_id); } else { // unlink from list, free memory registered_record_entry **ptr = &request->u.reg_recs; while (*ptr && (*ptr) != re) ptr = &(*ptr)->next; if (!*ptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] regrecord_callback - record not in list!", request->request_id); return; } *ptr = (*ptr)->next; freeL("registered_record_entry AuthRecord regrecord_callback", re->rr); freeL("registered_record_entry regrecord_callback", re); } } else { if (re->external_advertise) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] regrecord_callback: external_advertise already set!", request->request_id); } #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(re->origInterfaceID, &rr->namestorage, request->flags)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] regrecord_callback: calling external_start_advertising_service", request->request_id); external_start_advertising_service(&rr->resrec, request->flags, request->process_id); re->external_advertise = mDNStrue; } #endif } } } // set_peer_pid() is called after mem is allocated for each new request in NewRequest() // This accounts for 2 places (connect_callback, request_callback) mDNSlocal void set_peer_pid(request_state *request) { request->pid_name[0] = '\0'; request->process_id = -1; #ifdef LOCAL_PEEREPID pid_t p = (pid_t) -1; socklen_t len = sizeof(p); if (request->sd < 0) return; // to extract the effective pid value if (getsockopt(request->sd, SOL_LOCAL, LOCAL_PEEREPID, &p, &len) != 0) return; // to extract the process name from the pid value if (proc_pidinfo(p, PROC_PIDT_SHORTBSDINFO, 1, &proc, PROC_PIDT_SHORTBSDINFO_SIZE) == 0) return; mDNSPlatformStrLCopy(request->pid_name, proc.pbsi_comm, sizeof(request->pid_name)); request->process_id = p; debugf("set_peer_pid: Client PEEREPID is %d %s", p, request->pid_name); #else // !LOCAL_PEEREPID LogInfo("set_peer_pid: Not Supported on this version of OS"); if (request->sd < 0) return; #endif // LOCAL_PEEREPID } mDNSlocal void connection_termination(request_state *request) { // When terminating a shared connection, we need to scan the all_requests list // and terminate any subbordinate operations sharing this file descriptor request_state **req = &all_requests; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceCreateConnection STOP PID[%d](" PUB_S ")", request->request_id, request->process_id, request->pid_name); while (*req) { if ((*req)->primary == request) { // Since we're already doing a list traversal, we unlink the request directly instead of using AbortUnlinkAndFree() request_state *tmp = *req; if (tmp->primary == tmp) LogMsg("connection_termination ERROR (*req)->primary == *req for %p %d", tmp, tmp->sd); if (tmp->replies) LogMsg("connection_termination ERROR How can subordinate req %p %d have replies queued?", tmp, tmp->sd); abort_request(tmp); *req = tmp->next; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (tmp->trust) { void * context = mdns_trust_get_context(tmp->trust); mdns_trust_set_context(tmp->trust, NULL); if (context) freeL("context/connection_termination", context); mdns_trust_forget(&tmp->trust); } #endif freeL("request_state/connection_termination", tmp); } else req = &(*req)->next; } while (request->u.reg_recs) { registered_record_entry *ptr = request->u.reg_recs; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceRegisterRecord(0x%X, %d, " PRI_S ") STOP PID[%d](" PUB_S ")", request->request_id, request->flags, request->interfaceIndex, RRDisplayString(&mDNSStorage, &ptr->rr->resrec), request->process_id, request->pid_name); request->u.reg_recs = request->u.reg_recs->next; ptr->rr->RecordContext = NULL; if (ptr->external_advertise) { ptr->external_advertise = mDNSfalse; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_service(&ptr->rr->resrec, request->flags, request->process_id); #endif } LogMcastS(ptr->rr, request, reg_stop); mDNS_Deregister(&mDNSStorage, ptr->rr); // Will free ptr->rr for us freeL("registered_record_entry/connection_termination", ptr); } } mDNSlocal void handle_cancel_request(request_state *request) { request_state **req = &all_requests; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%d] Cancel %08X %08X", request->request_id, request->hdr.client_context.u32[1], request->hdr.client_context.u32[0]); while (*req) { if ((*req)->primary == request && (*req)->hdr.client_context.u32[0] == request->hdr.client_context.u32[0] && (*req)->hdr.client_context.u32[1] == request->hdr.client_context.u32[1]) { // Since we're already doing a list traversal, we unlink the request directly instead of using AbortUnlinkAndFree() request_state *tmp = *req; abort_request(tmp); *req = tmp->next; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (tmp->trust) { void * context = mdns_trust_get_context(tmp->trust); mdns_trust_set_context(tmp->trust, NULL); if (context) freeL("context/handle_cancel_request", context); mdns_trust_forget(&tmp->trust); } #endif freeL("request_state/handle_cancel_request", tmp); } else req = &(*req)->next; } } mDNSlocal mStatus _handle_regrecord_request_start(request_state *request, AuthRecord * rr) { mStatus err; registered_record_entry *re; // Don't allow non-local domains to be regsitered as LocalOnly. Allowing this would permit // clients to register records such as www.bigbank.com A w.x.y.z to redirect Safari. if (rr->resrec.InterfaceID == mDNSInterface_LocalOnly && !IsLocalDomain(rr->resrec.name) && rr->resrec.rrclass == kDNSClass_IN && (rr->resrec.rrtype == kDNSType_A || rr->resrec.rrtype == kDNSType_AAAA || rr->resrec.rrtype == kDNSType_CNAME)) { freeL("AuthRecord/handle_regrecord_request", rr); return (mStatus_BadParamErr); } // allocate registration entry, link into list re = (registered_record_entry *) callocL("registered_record_entry", sizeof(*re)); if (!re) FatalError("ERROR: calloc"); re->key = request->hdr.reg_index; re->rr = rr; re->regrec_client_context = request->hdr.client_context; re->request = request; re->external_advertise = mDNSfalse; rr->RecordContext = re; rr->RecordCallback = regrecord_callback; re->origInterfaceID = rr->resrec.InterfaceID; if (rr->resrec.InterfaceID == mDNSInterface_P2P) rr->resrec.InterfaceID = mDNSInterface_Any; #if 0 if (!AuthorizedDomain(request, rr->resrec.name, AutoRegistrationDomains)) return (mStatus_NoError); #endif if (rr->resrec.rroriginalttl == 0) rr->resrec.rroriginalttl = DefaultTTLforRRType(rr->resrec.rrtype); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceRegisterRecord(0x%X, %d, " PRI_S ") START PID[%d](" PUB_S ")", request->request_id, request->flags, request->interfaceIndex, RRDisplayString(&mDNSStorage, &rr->resrec), request->process_id, request->pid_name); err = mDNS_Register(&mDNSStorage, rr); if (err) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceRegisterRecord(0x%X, %d," PRI_S ") ERROR (%d)", request->request_id, request->flags, request->interfaceIndex, RRDisplayString(&mDNSStorage, &rr->resrec), err); freeL("registered_record_entry", re); freeL("registered_record_entry/AuthRecord", rr); } else { LogMcastS(rr, request, reg_start); re->next = request->u.reg_recs; request->u.reg_recs = re; } return err; } #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal void _return_regrecord_request_error(request_state *request, mStatus error) { reply_state *rep; if (GenerateNTDResponse(NULL, 0, request, &rep, reg_record_reply_op, 0, error) != mStatus_NoError) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] DNSServiceRegisterRecord _return_regrecord_request_error: error(%d)", request->request_id, error); } else { append_reply(request, rep); } } mDNSlocal mStatus _handle_regrecord_request_with_trust(request_state *request, AuthRecord * rr) { mStatus err; if (audit_token_to_pid(request->audit_token) == 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_WARNING, "[R%u] _handle_regrecord_request_with_trust: no audit token for pid(%s %d)", request->request_id, request->pid_name, request->process_id); err = _handle_regrecord_request_start(request, rr); } else { const char *service_ptr = NULL; char type_str[MAX_ESCAPED_DOMAIN_NAME] = ""; domainlabel name; domainname type, domain; bool good = DeconstructServiceName(rr->resrec.name, &name, &type, &domain); if (good) { ConvertDomainNameToCString(&type, type_str); service_ptr = type_str; } mdns_trust_flags_t flags = mdns_trust_flags_none; mdns_trust_status_t status = mdns_trust_check_bonjour(request->audit_token, service_ptr, &flags); switch (status) { case mdns_trust_status_denied: case mdns_trust_status_pending: { mdns_trust_t trust = mdns_trust_create(request->audit_token, service_ptr, flags); if (!trust) { freeL("AuthRecord/_handle_regrecord_request_with_trust", rr); err = mStatus_NoMemoryErr; goto exit; } mdns_trust_set_context(trust, rr); mdns_trust_set_queue(trust, _get_trust_results_dispatch_queue()); mdns_trust_set_event_handler(trust, ^(mdns_trust_event_t event, mdns_trust_status_t update) { if (event == mdns_trust_event_result) { mStatus error = (update != mdns_trust_status_granted) ? mStatus_PolicyDenied : mStatus_NoError; KQueueLock(); AuthRecord * _rr = mdns_trust_get_context(trust); if (_rr) { if (!error) { mdns_trust_set_context(trust, NULL); // _handle_regrecord_request_start handles free error = _handle_regrecord_request_start(request, _rr); // No context means the request was canceled before we got here } if (error) // (not else if) Always check for error result { _return_regrecord_request_error(request, error); } } KQueueUnlock("_handle_regrecord_request_with_trust"); } }); request->trust = trust; mdns_trust_activate(trust); err = mStatus_NoError; break; } case mdns_trust_status_no_entitlement: err = mStatus_NoAuth; break; case mdns_trust_status_granted: err = _handle_regrecord_request_start(request, rr); break; default: err = mStatus_UnknownErr; break; } } exit: return err; } #endif // TRUST_ENFORCEMENT mDNSlocal mStatus handle_regrecord_request(request_state *request) { mStatus err = mStatus_BadParamErr; AuthRecord *rr; if (request->terminate != connection_termination) { LogMsg("%3d: DNSServiceRegisterRecord(not a shared connection ref)", request->sd); return(err); } rr = read_rr_from_ipc_msg(request, 1, 1); if (rr) { #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (os_feature_enabled(mDNSResponder, bonjour_privacy) && IsLocalDomain(rr->resrec.name)) { err = _handle_regrecord_request_with_trust(request, rr); } else { err = _handle_regrecord_request_start(request, rr); } #else err = _handle_regrecord_request_start(request, rr); #endif } return(err); } mDNSlocal void UpdateDeviceInfoRecord(mDNS *const m); mDNSlocal void regservice_termination_callback(request_state *request) { if (!request) { LogMsg("regservice_termination_callback context is NULL"); return; } while (request->u.servicereg.instances) { service_instance *p = request->u.servicereg.instances; request->u.servicereg.instances = request->u.servicereg.instances->next; // only safe to free memory if registration is not valid, i.e. deregister fails (which invalidates p) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceRegister(" PRI_DM_NAME ", %u) STOP PID[%d](" PUB_S ")", request->request_id, DM_NAME_PARAM(p->srs.RR_SRV.resrec.name), mDNSVal16(p->srs.RR_SRV.resrec.rdata->u.srv.port), request->process_id, request->pid_name); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_helper(p); #endif // Clear backpointer *before* calling mDNS_DeregisterService/unlink_and_free_service_instance // We don't need unlink_and_free_service_instance to cut its element from the list, because we're already advancing // request->u.servicereg.instances as we work our way through the list, implicitly cutting one element at a time // We can't clear p->request *after* the calling mDNS_DeregisterService/unlink_and_free_service_instance // because by then we might have already freed p p->request = NULL; LogMcastS(&p->srs.RR_SRV, request, reg_stop); if (mDNS_DeregisterService(&mDNSStorage, &p->srs)) { unlink_and_free_service_instance(p); // Don't touch service_instance *p after this -- it's likely to have been freed already } } if (request->u.servicereg.txtdata) { freeL("service_info txtdata", request->u.servicereg.txtdata); request->u.servicereg.txtdata = NULL; } if (request->u.servicereg.autoname) { // Clear autoname before calling UpdateDeviceInfoRecord() so it doesn't mistakenly include this in its count of active autoname registrations request->u.servicereg.autoname = mDNSfalse; UpdateDeviceInfoRecord(&mDNSStorage); } } mDNSlocal request_state *LocateSubordinateRequest(request_state *request) { request_state *req; for (req = all_requests; req; req = req->next) if (req->primary == request && req->hdr.client_context.u32[0] == request->hdr.client_context.u32[0] && req->hdr.client_context.u32[1] == request->hdr.client_context.u32[1]) return(req); return(request); } mDNSlocal mStatus add_record_to_service(request_state *request, service_instance *instance, mDNSu16 rrtype, mDNSu16 rdlen, const mDNSu8 *const rdata, mDNSu32 ttl) { ServiceRecordSet *srs = &instance->srs; mStatus result; const size_t rdcapacity = (rdlen > sizeof(RDataBody2)) ? rdlen : sizeof(RDataBody2); ExtraResourceRecord *extra = (ExtraResourceRecord *)callocL("ExtraResourceRecord", sizeof(*extra) - sizeof(RDataBody) + rdcapacity); if (!extra) { my_perror("ERROR: calloc"); return mStatus_NoMemoryErr; } extra->r.resrec.rrtype = rrtype; extra->r.resrec.rdata = &extra->r.rdatastorage; extra->r.resrec.rdata->MaxRDLength = (mDNSu16)rdcapacity; extra->r.resrec.rdlength = rdlen; if (!SetRData(mDNSNULL, rdata, rdata + rdlen, &extra->r.resrec, rdlen)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] read_rr_from_ipc_msg: SetRData failed for " PRI_DM_NAME " (" PUB_S ")", request->request_id, DM_NAME_PARAM(request->u.servicereg.instances ? request->u.servicereg.instances->srs.RR_SRV.resrec.name : mDNSNULL), DNSTypeName(rrtype)); freeL("ExtraResourceRecord/add_record_to_service", extra); return mStatus_BadParamErr; } SetNewRData(&extra->r.resrec, mDNSNULL, 0); // Sets rr->rdatahash for us // use InterfaceID value from DNSServiceRegister() call that created the original service extra->r.resrec.InterfaceID = request->u.servicereg.InterfaceID; result = mDNS_AddRecordToService(&mDNSStorage, srs, extra, &extra->r.rdatastorage, ttl, request->flags); if (result) { freeL("ExtraResourceRecord/add_record_to_service", extra); return result; } LogMcastS(&srs->RR_PTR, request, reg_start); extra->ClientID = request->hdr.reg_index; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if ( instance->external_advertise && callExternalHelpers(request->u.servicereg.InterfaceID, &instance->domain, request->flags)) { LogInfo("add_record_to_service: calling external_start_advertising_service"); external_start_advertising_service(&extra->r.resrec, request->flags, request->process_id); } #endif return result; } mDNSlocal mStatus handle_add_request(request_state *request) { service_instance *i; mStatus result = mStatus_UnknownErr; DNSServiceFlags flags = get_flags (&request->msgptr, request->msgend); mDNSu16 rrtype = get_uint16(&request->msgptr, request->msgend); mDNSu16 rdlen = get_uint16(&request->msgptr, request->msgend); const mDNSu8 *const rdata = (const mDNSu8 *)get_rdata(&request->msgptr, request->msgend, rdlen); mDNSu32 ttl = get_uint32(&request->msgptr, request->msgend); if (!ttl) ttl = DefaultTTLforRRType(rrtype); (void)flags; // Unused if (!request->msgptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceAddRecord(unreadable parameters)", request->request_id); return(mStatus_BadParamErr); } // If this is a shared connection, check if the operation actually applies to a subordinate request_state object if (request->terminate == connection_termination) request = LocateSubordinateRequest(request); if (request->terminate != regservice_termination_callback) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceAddRecord(not a registered service ref)", request->request_id); return(mStatus_BadParamErr); } // For a service registered with zero port, don't allow adding records. This mostly happens due to a bug // in the application. See radar://9165807. if (mDNSIPPortIsZero(request->u.servicereg.port)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceAddRecord: adding record to a service registered with zero port", request->request_id); return(mStatus_BadParamErr); } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceAddRecord(%X, " PRI_DM_NAME ", " PUB_S ", %d) PID[%d](" PUB_S ")", request->request_id, flags, DM_NAME_PARAM((request->u.servicereg.instances) ? (request->u.servicereg.instances->srs.RR_SRV.resrec.name) : mDNSNULL), DNSTypeName(rrtype), rdlen, request->process_id, request->pid_name); for (i = request->u.servicereg.instances; i; i = i->next) { result = add_record_to_service(request, i, rrtype, rdlen, rdata, ttl); if (result && i->default_local) break; else result = mStatus_NoError; // suppress non-local default errors } return(result); } mDNSlocal void update_callback(mDNS *const m, AuthRecord *const rr, RData *oldrd, mDNSu16 oldrdlen) { mDNSBool external_advertise = (rr->UpdateContext) ? *((mDNSBool *)rr->UpdateContext) : mDNSfalse; (void)m; // Unused // There are three cases. // // 1. We have updated the primary TXT record of the service // 2. We have updated the TXT record that was added to the service using DNSServiceAddRecord // 3. We have updated the TXT record that was registered using DNSServiceRegisterRecord // // external_advertise is set if we have advertised at least once during the initial addition // of the record in all of the three cases above. We should have checked for InterfaceID/LocalDomain // checks during the first time and hence we don't do any checks here if (external_advertise) { ResourceRecord ext = rr->resrec; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) DNSServiceFlags flags = deriveD2DFlagsFromAuthRecType(rr->ARType); #endif if (ext.rdlength == oldrdlen && mDNSPlatformMemSame(&ext.rdata->u, &oldrd->u, oldrdlen)) goto exit; SetNewRData(&ext, oldrd, oldrdlen); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_service(&ext, flags, 0); LogInfo("update_callback: calling external_start_advertising_service"); external_start_advertising_service(&rr->resrec, flags, 0); #endif } exit: if (oldrd != &rr->rdatastorage) freeL("RData/update_callback", oldrd); } mDNSlocal mStatus update_record(AuthRecord *ar, mDNSu16 rdlen, const mDNSu8 *const rdata, mDNSu32 ttl, const mDNSBool *const external_advertise, const mDNSu32 request_id) { ResourceRecord rr; mStatus result; const size_t rdcapacity = (rdlen > sizeof(RDataBody2)) ? rdlen : sizeof(RDataBody2); RData *newrd = (RData *) callocL("RData/update_record", sizeof(*newrd) - sizeof(RDataBody) + rdcapacity); if (!newrd) FatalError("ERROR: calloc"); mDNSPlatformMemZero(&rr, (mDNSu32)sizeof(rr)); rr.name = ar->resrec.name; rr.rrtype = ar->resrec.rrtype; rr.rrclass = ar->resrec.rrclass; rr.rdata = newrd; rr.rdata->MaxRDLength = (mDNSu16)rdcapacity; rr.rdlength = rdlen; if (!SetRData(mDNSNULL, rdata, rdata + rdlen, &rr, rdlen)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] update_record: SetRData failed for " PRI_DM_NAME " (" PUB_S ")", request_id, DM_NAME_PARAM(rr.name), DNSTypeName(rr.rrtype)); freeL("RData/update_record", newrd); return mStatus_BadParamErr; } rdlen = GetRDLength(&rr, mDNSfalse); // BIND named (name daemon) doesn't allow TXT records with zero-length rdata. This is strictly speaking correct, // since RFC 1035 specifies a TXT record as "One or more s", not "Zero or more s". // Since some legacy apps try to create zero-length TXT records, we'll silently correct it here. if (ar->resrec.rrtype == kDNSType_TXT && rdlen == 0) { rdlen = 1; newrd->u.txt.c[0] = 0; } if (external_advertise) ar->UpdateContext = (void *)external_advertise; result = mDNS_Update(&mDNSStorage, ar, ttl, rdlen, newrd, update_callback); if (result) { LogMsg("update_record: Error %d for %s", (int)result, ARDisplayString(&mDNSStorage, ar)); freeL("RData/update_record", newrd); } return result; } mDNSlocal mStatus handle_update_request(request_state *request) { const ipc_msg_hdr *const hdr = &request->hdr; mStatus result = mStatus_BadReferenceErr; service_instance *i; AuthRecord *rr = NULL; // get the message data DNSServiceFlags flags = get_flags (&request->msgptr, request->msgend); // flags unused mDNSu16 rdlen = get_uint16(&request->msgptr, request->msgend); const mDNSu8 *const rdata = (const mDNSu8 *)get_rdata(&request->msgptr, request->msgend, rdlen); mDNSu32 ttl = get_uint32(&request->msgptr, request->msgend); (void)flags; // Unused if (!request->msgptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceUpdateRecord(unreadable parameters)", request->request_id); return(mStatus_BadParamErr); } // If this is a shared connection, check if the operation actually applies to a subordinate request_state object if (request->terminate == connection_termination) request = LocateSubordinateRequest(request); if (request->terminate == connection_termination) { // update an individually registered record registered_record_entry *reptr; for (reptr = request->u.reg_recs; reptr; reptr = reptr->next) { if (reptr->key == hdr->reg_index) { result = update_record(reptr->rr, rdlen, rdata, ttl, &reptr->external_advertise, request->request_id); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceUpdateRecord(" PRI_DM_NAME ", " PUB_S ") PID[%d](" PUB_S ")", request->request_id, DM_NAME_PARAM(reptr->rr->resrec.name), reptr->rr ? DNSTypeName(reptr->rr->resrec.rrtype) : "", request->process_id, request->pid_name); goto end; } } result = mStatus_BadReferenceErr; goto end; } if (request->terminate != regservice_termination_callback) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceUpdateRecord(not a registered service ref)", request->request_id); return(mStatus_BadParamErr); } // For a service registered with zero port, only SRV record is initialized. Don't allow any updates. if (mDNSIPPortIsZero(request->u.servicereg.port)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceUpdateRecord: updating the record of a service registered with zero port", request->request_id); return(mStatus_BadParamErr); } // update the saved off TXT data for the service if (hdr->reg_index == TXT_RECORD_INDEX) { if (request->u.servicereg.txtdata) { freeL("service_info txtdata", request->u.servicereg.txtdata); request->u.servicereg.txtdata = NULL; } if (rdlen > 0) { request->u.servicereg.txtdata = mallocL("service_info txtdata", rdlen); if (!request->u.servicereg.txtdata) FatalError("ERROR: handle_update_request - malloc"); mDNSPlatformMemCopy(request->u.servicereg.txtdata, rdata, rdlen); } request->u.servicereg.txtlen = rdlen; } // update a record from a service record set for (i = request->u.servicereg.instances; i; i = i->next) { if (hdr->reg_index == TXT_RECORD_INDEX) rr = &i->srs.RR_TXT; else { ExtraResourceRecord *e; for (e = i->srs.Extras; e; e = e->next) if (e->ClientID == hdr->reg_index) { rr = &e->r; break; } } if (!rr) { result = mStatus_BadReferenceErr; goto end; } result = update_record(rr, rdlen, rdata, ttl, &i->external_advertise, request->request_id); if (result && i->default_local) goto end; else result = mStatus_NoError; // suppress non-local default errors } end: if (request->terminate == regservice_termination_callback) LogOperation("%3d: DNSServiceUpdateRecord(%##s, %s) PID[%d](%s)", request->sd, (request->u.servicereg.instances) ? request->u.servicereg.instances->srs.RR_SRV.resrec.name->c : NULL, rr ? DNSTypeName(rr->resrec.rrtype) : "", request->process_id, request->pid_name); return(result); } // remove a resource record registered via DNSServiceRegisterRecord() mDNSlocal mStatus remove_record(request_state *request) { mStatus err = mStatus_UnknownErr; registered_record_entry *e, **ptr = &request->u.reg_recs; while (*ptr && (*ptr)->key != request->hdr.reg_index) ptr = &(*ptr)->next; if (!*ptr) { LogMsg("%3d: DNSServiceRemoveRecord(%u) not found", request->sd, request->hdr.reg_index); return mStatus_BadReferenceErr; } e = *ptr; *ptr = e->next; // unlink LogOperation("%3d: DNSServiceRemoveRecord(%u %s) PID[%d](%s)", request->sd, e->key, RRDisplayString(&mDNSStorage, &e->rr->resrec), request->process_id, request->pid_name); e->rr->RecordContext = NULL; if (e->external_advertise) { #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_stop_advertising_service(&e->rr->resrec, request->flags, request->process_id); #endif e->external_advertise = mDNSfalse; } LogMcastS(e->rr, request, reg_stop); err = mDNS_Deregister(&mDNSStorage, e->rr); // Will free e->rr for us; we're responsible for freeing e if (err) { LogMsg("ERROR: remove_record, mDNS_Deregister: %d", err); freeL("registered_record_entry AuthRecord remove_record", e->rr); } freeL("registered_record_entry remove_record", e); return err; } mDNSlocal mStatus remove_extra(const request_state *const request, service_instance *const serv, mDNSu16 *const rrtype) { mStatus err = mStatus_BadReferenceErr; ExtraResourceRecord *ptr; for (ptr = serv->srs.Extras; ptr; ptr = ptr->next) { if (ptr->ClientID == request->hdr.reg_index) // found match { *rrtype = ptr->r.resrec.rrtype; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (serv->external_advertise) { external_stop_advertising_service(&ptr->r.resrec, request->flags, request->process_id); } #endif err = mDNS_RemoveRecordFromService(&mDNSStorage, &serv->srs, ptr, FreeExtraRR, ptr); break; } } return err; } mDNSlocal mStatus handle_removerecord_request(request_state *request) { mStatus err = mStatus_BadReferenceErr; get_flags(&request->msgptr, request->msgend); // flags unused if (!request->msgptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceRemoveRecord(unreadable parameters)", request->request_id); return(mStatus_BadParamErr); } // If this is a shared connection, check if the operation actually applies to a subordinate request_state object if (request->terminate == connection_termination) request = LocateSubordinateRequest(request); if (request->terminate == connection_termination) err = remove_record(request); // remove individually registered record else if (request->terminate != regservice_termination_callback) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceRemoveRecord(not a registered service ref)", request->request_id); return(mStatus_BadParamErr); } else { service_instance *i; mDNSu16 rrtype = 0; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceRemoveRecord(" PRI_DM_NAME ", " PUB_S ") PID[%d](" PUB_S ")", request->request_id, DM_NAME_PARAM((request->u.servicereg.instances) ? (request->u.servicereg.instances->srs.RR_SRV.resrec.name) : mDNSNULL), rrtype ? DNSTypeName(rrtype) : "", request->process_id, request->pid_name); for (i = request->u.servicereg.instances; i; i = i->next) { err = remove_extra(request, i, &rrtype); if (err && i->default_local) break; else err = mStatus_NoError; // suppress non-local default errors } } return(err); } // If there's a comma followed by another character, // FindFirstSubType overwrites the comma with a nul and returns the pointer to the next character. // Otherwise, it returns a pointer to the final nul at the end of the string mDNSlocal char *FindFirstSubType(char *p) { while (*p) { if (p[0] == '\\' && p[1]) { p += 2; } else if (p[0] == ',' && p[1]) { *p++ = 0; return(p); } else { p++; } } return(p); } // If there's a comma followed by another character, // FindNextSubType overwrites the comma with a nul and returns the pointer to the next character. // If it finds an illegal unescaped dot in the subtype name, it returns mDNSNULL // Otherwise, it returns a pointer to the final nul at the end of the string mDNSlocal char *FindNextSubType(char *p) { while (*p) { if (p[0] == '\\' && p[1]) // If escape character p += 2; // ignore following character else if (p[0] == ',') // If we found a comma { if (p[1]) *p++ = 0; return(p); } else if (p[0] == '.') return(mDNSNULL); else p++; } return(p); } // Returns -1 if illegal subtype found mDNSlocal mDNSs32 ChopSubTypes(char *regtype) { mDNSs32 NumSubTypes = 0; char *stp = FindFirstSubType(regtype); while (stp && *stp) // If we found a comma... { if (*stp == ',') return(-1); NumSubTypes++; stp = FindNextSubType(stp); } if (!stp) return(-1); return(NumSubTypes); } mDNSlocal AuthRecord *AllocateSubTypes(mDNSs32 NumSubTypes, char *p) { AuthRecord *st = mDNSNULL; if (NumSubTypes) { mDNSs32 i; st = (AuthRecord *) callocL("ServiceSubTypes", NumSubTypes * sizeof(AuthRecord)); if (!st) return(mDNSNULL); for (i = 0; i < NumSubTypes; i++) { mDNS_SetupResourceRecord(&st[i], mDNSNULL, mDNSInterface_Any, kDNSQType_ANY, kStandardTTL, 0, AuthRecordAny, mDNSNULL, mDNSNULL); while (*p) p++; p++; if (!MakeDomainNameFromDNSNameString(&st[i].namestorage, p)) { freeL("ServiceSubTypes", st); return(mDNSNULL); } } } return(st); } mDNSlocal mStatus register_service_instance(request_state *request, const domainname *domain) { service_instance **ptr, *instance; size_t extra_size = (request->u.servicereg.txtlen > sizeof(RDataBody)) ? (request->u.servicereg.txtlen - sizeof(RDataBody)) : 0; const mDNSBool DomainIsLocal = SameDomainName(domain, &localdomain); mStatus result; mDNSInterfaceID interfaceID = request->u.servicereg.InterfaceID; // If the client specified an interface, but no domain, then we honor the specified interface for the "local" (mDNS) // registration but for the wide-area registrations we don't (currently) have any concept of a wide-area unicast // registrations scoped to a specific interface, so for the automatic domains we add we must *not* specify an interface. // (Specifying an interface with an apparently wide-area domain (i.e. something other than "local") // currently forces the registration to use mDNS multicast despite the apparently wide-area domain.) if (request->u.servicereg.default_domain && !DomainIsLocal) interfaceID = mDNSInterface_Any; for (ptr = &request->u.servicereg.instances; *ptr; ptr = &(*ptr)->next) { if (SameDomainName(&(*ptr)->domain, domain)) { LogMsg("register_service_instance: domain %##s already registered for %#s.%##s", domain->c, &request->u.servicereg.name, &request->u.servicereg.type); return mStatus_AlreadyRegistered; } } instance = (service_instance *) callocL("service_instance", sizeof(*instance) + extra_size); if (!instance) { my_perror("ERROR: calloc"); return mStatus_NoMemoryErr; } instance->next = mDNSNULL; instance->request = request; instance->renameonmemfree = 0; instance->clientnotified = mDNSfalse; instance->default_local = (request->u.servicereg.default_domain && DomainIsLocal); instance->external_advertise = mDNSfalse; AssignDomainName(&instance->domain, domain); instance->subtypes = AllocateSubTypes(request->u.servicereg.num_subtypes, request->u.servicereg.type_as_string); if (request->u.servicereg.num_subtypes && !instance->subtypes) { unlink_and_free_service_instance(instance); instance = NULL; FatalError("ERROR: malloc"); } result = mDNS_RegisterService(&mDNSStorage, &instance->srs, &request->u.servicereg.name, &request->u.servicereg.type, domain, request->u.servicereg.host.c[0] ? &request->u.servicereg.host : NULL, request->u.servicereg.port, mDNSNULL, request->u.servicereg.txtdata, request->u.servicereg.txtlen, instance->subtypes, request->u.servicereg.num_subtypes, interfaceID, regservice_callback, instance, request->flags); if (!result) { *ptr = instance; // Append this to the end of our request->u.servicereg.instances list LogOperation("%3d: DNSServiceRegister(%##s, %u) ADDED", instance->request->sd, instance->srs.RR_SRV.resrec.name->c, mDNSVal16(request->u.servicereg.port)); LogMcastS(&instance->srs.RR_SRV, request, reg_start); } else { LogMsg("register_service_instance %#s.%##s%##s error %d", &request->u.servicereg.name, &request->u.servicereg.type, domain->c, result); unlink_and_free_service_instance(instance); } return result; } mDNSlocal void udsserver_default_reg_domain_changed(const DNameListElem *const d, const mDNSBool add) { request_state *request; LogMsg("%s registration domain %##s", add ? "Adding" : "Removing", d->name.c); for (request = all_requests; request; request = request->next) { if (request->terminate != regservice_termination_callback) continue; if (!request->u.servicereg.default_domain) continue; if (!d->uid || SystemUID(request->uid) || request->uid == d->uid) { service_instance **ptr = &request->u.servicereg.instances; while (*ptr && !SameDomainName(&(*ptr)->domain, &d->name)) ptr = &(*ptr)->next; if (add) { // If we don't already have this domain in our list for this registration, add it now if (!*ptr) register_service_instance(request, &d->name); else debugf("udsserver_default_reg_domain_changed %##s already in list, not re-adding", &d->name); } else { // Normally we should not fail to find the specified instance // One case where this can happen is if a uDNS update fails for some reason, // and regservice_callback then calls unlink_and_free_service_instance and disposes of that instance. if (!*ptr) LogMsg("udsserver_default_reg_domain_changed domain %##s not found for service %#s type %s", &d->name, request->u.servicereg.name.c, request->u.servicereg.type_as_string); else { DNameListElem *p; for (p = AutoRegistrationDomains; p; p=p->next) if (!p->uid || SystemUID(request->uid) || request->uid == p->uid) if (SameDomainName(&d->name, &p->name)) break; if (p) debugf("udsserver_default_reg_domain_changed %##s still in list, not removing", &d->name); else { mStatus err; service_instance *si = *ptr; *ptr = si->next; if (si->clientnotified) SendServiceRemovalNotification(&si->srs); // Do this *before* clearing si->request backpointer // Now that we've cut this service_instance from the list, we MUST clear the si->request backpointer. // Otherwise what can happen is this: While our mDNS_DeregisterService is in the // process of completing asynchronously, the client cancels the entire operation, so // regservice_termination_callback then runs through the whole list deregistering each // instance, clearing the backpointers, and then disposing the parent request_state object. // However, because this service_instance isn't in the list any more, regservice_termination_callback // has no way to find it and clear its backpointer, and then when our mDNS_DeregisterService finally // completes later with a mStatus_MemFree message, it calls unlink_and_free_service_instance() with // a service_instance with a stale si->request backpointer pointing to memory that's already been freed. si->request = NULL; err = mDNS_DeregisterService(&mDNSStorage, &si->srs); if (err) { LogMsg("udsserver_default_reg_domain_changed err %d", err); unlink_and_free_service_instance(si); } } } } } } } // Returns true if the interfaceIndex value matches one of the pre-defined // special values listed in the switch statement below. mDNSlocal mDNSBool PreDefinedInterfaceIndex(mDNSu32 interfaceIndex) { switch(interfaceIndex) { case kDNSServiceInterfaceIndexAny: case kDNSServiceInterfaceIndexLocalOnly: case kDNSServiceInterfaceIndexUnicast: case kDNSServiceInterfaceIndexP2P: case kDNSServiceInterfaceIndexBLE: return mDNStrue; default: return mDNSfalse; } } mDNSlocal mStatus _handle_regservice_request_start(request_state *request, const domainname * const d) { mStatus err; request->terminate = regservice_termination_callback; err = register_service_instance(request, d); #if MDNSRESPONDER_SUPPORTS(APPLE, METRICS) ++curr_num_regservices; if (curr_num_regservices > max_num_regservices) max_num_regservices = curr_num_regservices; #endif #if 0 err = AuthorizedDomain(request, d, AutoRegistrationDomains) ? register_service_instance(request, d) : mStatus_NoError; #endif if (!err) { if (request->u.servicereg.autoname) UpdateDeviceInfoRecord(&mDNSStorage); if (request->u.servicereg.default_domain) { DNameListElem *ptr; // Note that we don't report errors for non-local, non-explicit domains for (ptr = AutoRegistrationDomains; ptr; ptr = ptr->next) if (!ptr->uid || SystemUID(request->uid) || request->uid == ptr->uid) register_service_instance(request, &ptr->name); } } return err; } #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal void _return_regservice_request_error(request_state *request, mStatus error) { if (request->u.servicereg.txtdata) { freeL("service_info txtdata", request->u.servicereg.txtdata); request->u.servicereg.txtdata = NULL; } reply_state *rep; if (GenerateNTDResponse(NULL, 0, request, &rep, reg_service_reply_op, 0, error) != mStatus_NoError) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] DNSServiceRegister _return_regservice_request_error: error(%d)", request->request_id, error); } else { append_reply(request, rep); } } mDNSlocal mStatus _handle_regservice_request_with_trust(request_state *request, const domainname * const d) { mStatus err; if (audit_token_to_pid(request->audit_token) == 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_WARNING, "[R%u] _handle_regservice_request_with_trust: no audit token for pid(%s %d)", request->request_id, request->pid_name, request->process_id); err = _handle_regservice_request_start(request, d); } else { mdns_trust_flags_t flags = mdns_trust_flags_none; mdns_trust_status_t status = mdns_trust_check_register_service(request->audit_token, request->u.servicereg.type_as_string, &flags); switch (status) { case mdns_trust_status_denied: case mdns_trust_status_pending: { mdns_trust_t trust = mdns_trust_create(request->audit_token, request->u.servicereg.type_as_string, flags); if (!trust) { err = mStatus_NoMemoryErr; goto exit; } void * context = mallocL("context/_handle_regservice_request_with_trust", sizeof(domainname)); if (!context) { my_perror("ERROR: mallocL context/_handle_regservice_request_with_trust"); mdns_release(trust); err = mStatus_NoMemoryErr; goto exit; } memcpy(context, d, sizeof(domainname)); mdns_trust_set_context(trust, context); mdns_trust_set_queue(trust, _get_trust_results_dispatch_queue()); mdns_trust_set_event_handler(trust, ^(mdns_trust_event_t event, mdns_trust_status_t update) { if (event == mdns_trust_event_result) { mStatus error = (update != mdns_trust_status_granted) ? mStatus_PolicyDenied : mStatus_NoError; KQueueLock(); const domainname * _d = mdns_trust_get_context(trust); if (_d) { if (!error) { error = _handle_regservice_request_start(request, _d); // No context means the request was canceled before we got here } if (error) // (not else if) Always check for error result { _return_regservice_request_error(request, error); } } KQueueUnlock("_register_service_instance_with_trust"); } }); request->trust = trust; mdns_trust_activate(trust); err = mStatus_NoError; break; } case mdns_trust_status_no_entitlement: err = mStatus_NoAuth; break; case mdns_trust_status_granted: err = _handle_regservice_request_start(request, d); break; default: err = mStatus_UnknownErr; break; } } exit: return err; } #endif // TRUST_ENFORCEMENT mDNSlocal mStatus handle_regservice_request(request_state *request) { char name[256]; // Lots of spare space for extra-long names that we'll auto-truncate down to 63 bytes char domain[MAX_ESCAPED_DOMAIN_NAME], host[MAX_ESCAPED_DOMAIN_NAME]; char type_as_string[MAX_ESCAPED_DOMAIN_NAME]; // Note that this service type may include a trailing list of subtypes domainname d, srv; mStatus err; const char *msgTXTData; DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); mDNSu32 interfaceIndex = get_uint32(&request->msgptr, request->msgend); mDNSInterfaceID InterfaceID; // Map kDNSServiceInterfaceIndexP2P to kDNSServiceInterfaceIndexAny with the // kDNSServiceFlagsIncludeP2P flag set. if (interfaceIndex == kDNSServiceInterfaceIndexP2P) { LogOperation("handle_regservice_request: mapping kDNSServiceInterfaceIndexP2P to kDNSServiceInterfaceIndexAny + kDNSServiceFlagsIncludeP2P"); flags |= kDNSServiceFlagsIncludeP2P; interfaceIndex = kDNSServiceInterfaceIndexAny; } InterfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, interfaceIndex); // The registration is scoped to a specific interface index, but the // interface is not currently in our list. if (interfaceIndex && !InterfaceID) { // If it's one of the specially defined inteface index values, just return an error. if (PreDefinedInterfaceIndex(interfaceIndex)) { LogInfo("handle_regservice_request: bad interfaceIndex %d", interfaceIndex); return(mStatus_BadParamErr); } // Otherwise, use the specified interface index value and the registration will // be applied to that interface when it comes up. InterfaceID = (mDNSInterfaceID)(uintptr_t)interfaceIndex; LogInfo("handle_regservice_request: registration pending for interface index %d", interfaceIndex); } if (get_string(&request->msgptr, request->msgend, name, sizeof(name )) < 0 || get_string(&request->msgptr, request->msgend, type_as_string, sizeof(type_as_string)) < 0 || get_string(&request->msgptr, request->msgend, domain, sizeof(domain )) < 0 || get_string(&request->msgptr, request->msgend, host, sizeof(host )) < 0) { LogMsg("ERROR: handle_regservice_request - Couldn't read name/regtype/domain"); return(mStatus_BadParamErr); } request->flags = flags; request->interfaceIndex = interfaceIndex; request->u.servicereg.InterfaceID = InterfaceID; request->u.servicereg.instances = NULL; request->u.servicereg.txtlen = 0; request->u.servicereg.txtdata = NULL; mDNSPlatformStrLCopy(request->u.servicereg.type_as_string, type_as_string, sizeof(request->u.servicereg.type_as_string)); if (request->msgptr + 2 > request->msgend) request->msgptr = NULL; else { request->u.servicereg.port.b[0] = *request->msgptr++; request->u.servicereg.port.b[1] = *request->msgptr++; } request->u.servicereg.txtlen = get_uint16(&request->msgptr, request->msgend); msgTXTData = get_rdata(&request->msgptr, request->msgend, request->u.servicereg.txtlen); if (!request->msgptr) { LogMsg("%3d: DNSServiceRegister(unreadable parameters)", request->sd); return(mStatus_BadParamErr); } if (request->u.servicereg.txtlen) { request->u.servicereg.txtdata = mallocL("service_info txtdata", request->u.servicereg.txtlen); if (!request->u.servicereg.txtdata) FatalError("ERROR: handle_regservice_request - malloc"); mDNSPlatformMemCopy(request->u.servicereg.txtdata, msgTXTData, request->u.servicereg.txtlen); } // Check for sub-types after the service type request->u.servicereg.num_subtypes = ChopSubTypes(request->u.servicereg.type_as_string); // Note: Modifies regtype string to remove trailing subtypes if (request->u.servicereg.num_subtypes < 0) { LogMsg("ERROR: handle_regservice_request - ChopSubTypes failed %s", request->u.servicereg.type_as_string); goto bad_param; } // Don't try to construct "domainname t" until *after* ChopSubTypes has worked its magic if (!*request->u.servicereg.type_as_string || !MakeDomainNameFromDNSNameString(&request->u.servicereg.type, request->u.servicereg.type_as_string)) { LogMsg("ERROR: handle_regservice_request - type_as_string bad %s", request->u.servicereg.type_as_string); goto bad_param; } if (!name[0]) { request->u.servicereg.name = mDNSStorage.nicelabel; request->u.servicereg.autoname = mDNStrue; } else { // If the client is allowing AutoRename, then truncate name to legal length before converting it to a DomainLabel if ((flags & kDNSServiceFlagsNoAutoRename) == 0) { int newlen = TruncateUTF8ToLength((mDNSu8*)name, mDNSPlatformStrLen(name), MAX_DOMAIN_LABEL); name[newlen] = 0; } if (!MakeDomainLabelFromLiteralString(&request->u.servicereg.name, name)) { LogMsg("ERROR: handle_regservice_request - name bad %s", name); goto bad_param; } request->u.servicereg.autoname = mDNSfalse; } if (*domain) { request->u.servicereg.default_domain = mDNSfalse; if (!MakeDomainNameFromDNSNameString(&d, domain)) { LogMsg("ERROR: handle_regservice_request - domain bad %s", domain); goto bad_param; } } else { request->u.servicereg.default_domain = mDNStrue; MakeDomainNameFromDNSNameString(&d, "local."); } if (!ConstructServiceName(&srv, &request->u.servicereg.name, &request->u.servicereg.type, &d)) { LogMsg("ERROR: handle_regservice_request - Couldn't ConstructServiceName from, “%#s” “%##s” “%##s”", request->u.servicereg.name.c, request->u.servicereg.type.c, d.c); goto bad_param; } if (!MakeDomainNameFromDNSNameString(&request->u.servicereg.host, host)) { LogMsg("ERROR: handle_regservice_request - host bad %s", host); goto bad_param; } request->u.servicereg.autorename = (flags & kDNSServiceFlagsNoAutoRename ) == 0; request->u.servicereg.allowremotequery = (flags & kDNSServiceFlagsAllowRemoteQuery) != 0; // Some clients use mDNS for lightweight copy protection, registering a pseudo-service with // a port number of zero. When two instances of the protected client are allowed to run on one // machine, we don't want to see misleading "Bogus client" messages in syslog and the console. if (!mDNSIPPortIsZero(request->u.servicereg.port)) { int count = CountExistingRegistrations(&srv, request->u.servicereg.port); if (count) LogMsg("Client application[%d](%s) registered %d identical instances of service %##s port %u.", request->process_id, request->pid_name, count+1, srv.c, mDNSVal16(request->u.servicereg.port)); } #if APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR // Determine if this request should be promoted to use BLE triggered feature. if (shouldUseBLE(InterfaceID, 0, &request->u.servicereg.type, &d)) { request->flags |= (kDNSServiceFlagsAutoTrigger | kDNSServiceFlagsIncludeAWDL); LogInfo("handle_regservice_request: registration promoted to use kDNSServiceFlagsAutoTrigger"); } #endif // APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceRegister(%X, %d, \"" PRI_S "\", \"" PRI_S "\", \"" PRI_S "\", \"" PRI_S "\", %u) START PID[%d](" PUB_S ")", request->request_id, request->flags, interfaceIndex, name, request->u.servicereg.type_as_string, domain, host, mDNSVal16(request->u.servicereg.port), request->process_id, request->pid_name); // We need to unconditionally set request->terminate, because even if we didn't successfully // start any registrations right now, subsequent configuration changes may cause successful // registrations to be added, and we'll need to cancel them before freeing this memory. // We also need to set request->terminate first, before adding additional service instances, // because the udsserver_validatelists uses the request->terminate function pointer to determine // what kind of request this is, and therefore what kind of list validation is required. request->terminate = NULL; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (os_feature_enabled(mDNSResponder, bonjour_privacy) && (request->u.servicereg.default_domain || IsLocalDomain(&d))) { err = _handle_regservice_request_with_trust(request, &d); if (err == mStatus_NoAuth && request->u.servicereg.txtdata) { freeL("service_info txtdata", request->u.servicereg.txtdata); request->u.servicereg.txtdata = NULL; } } else { err = _handle_regservice_request_start(request, &d); } #else err = _handle_regservice_request_start(request, &d); #endif return(err); bad_param: freeL("handle_regservice_request (txtdata)", request->u.servicereg.txtdata); request->u.servicereg.txtdata = NULL; return mStatus_BadParamErr; } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceBrowse #endif mDNSlocal void FoundInstance(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) { DNSServiceFlags flags = AddRecord ? kDNSServiceFlagsAdd : 0; request_state *req = question->QuestionContext; reply_state *rep; (void)m; // Unused if (answer->rrtype != kDNSType_PTR) { LogMsg("%3d: FoundInstance: Should not be called with rrtype %d (not a PTR record)", req->sd, answer->rrtype); return; } if (mDNSOpaque16IsZero(question->TargetQID) && (question->BrowseThreshold > 0) && (question->CurrentAnswers >= question->BrowseThreshold)) { flags |= kDNSServiceFlagsThresholdReached; } // if returning a negative answer, then use question's name in reply if (answer->RecordType == kDNSRecordTypePacketNegative) { GenerateBrowseReply(&question->qname, answer->InterfaceID, req, &rep, browse_reply_op, flags, kDNSServiceErr_NoSuchRecord); goto validReply; } if (GenerateNTDResponse(&answer->rdata->u.name, answer->InterfaceID, req, &rep, browse_reply_op, flags, mStatus_NoError) != mStatus_NoError) { if (SameDomainName(&req->u.browser.regtype, (const domainname*)"\x09_services\x07_dns-sd\x04_udp")) { // Special support to enable the DNSServiceBrowse call made by Bonjour Browser // Remove after Bonjour Browser is updated to use DNSServiceQueryRecord instead of DNSServiceBrowse GenerateBrowseReply(&answer->rdata->u.name, answer->InterfaceID, req, &rep, browse_reply_op, flags, mStatus_NoError); goto validReply; } LogMsg("%3d: FoundInstance: %##s PTR %##s received from network is not valid DNS-SD service pointer", req->sd, answer->name->c, answer->rdata->u.name.c); return; } validReply: LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] DNSServiceBrowse(" PRI_DM_NAME ", " PUB_S ") RESULT " PUB_S " interface %d: " PRI_S, req->request_id, mDNSVal16(question->TargetQID), DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype), AddRecord ? "ADD" : "RMV", mDNSPlatformInterfaceIndexfromInterfaceID(m, answer->InterfaceID, mDNSfalse), RRDisplayString(m, answer)); append_reply(req, rep); } mDNSlocal void SetQuestionPolicy(DNSQuestion *q, request_state *req) { q->euid = req->uid; // The policy is either based on pid or UUID. Pass a zero pid // to the "core" if the UUID is valid. If we always pass the pid, // then the "core" needs to determine whether the uuid is valid // by examining all the 16 bytes at the time of the policy // check and also when setting the delegate socket option. Also, it // requires that we zero out the uuid wherever the question is // initialized to make sure that it is not interpreted as valid. // To prevent these intrusive changes, just pass a zero pid to indicate // that pid is not valid when uuid is valid. In future if we need the // pid in the question, we will reevaluate this strategy. if (req->validUUID) { mDNSPlatformMemCopy(q->uuid, req->uuid, UUID_SIZE); q->pid = 0; } else { q->pid = req->process_id; } //debugf("SetQuestionPolicy: q->euid[%d] q->pid[%d] uuid is valid : %s", q->euid, q->pid, req->validUUID ? "true" : "false"); } mDNSlocal mStatus add_domain_to_browser(request_state *info, const domainname *d) { browser_t *b, *p; mStatus err; for (p = info->u.browser.browsers; p; p = p->next) { if (SameDomainName(&p->domain, d)) { debugf("add_domain_to_browser %##s already in list", d->c); return mStatus_AlreadyRegistered; } } b = (browser_t *) callocL("browser_t", sizeof(*b)); if (!b) return mStatus_NoMemoryErr; AssignDomainName(&b->domain, d); SetQuestionPolicy(&b->q, info); err = mDNS_StartBrowse(&mDNSStorage, &b->q, &info->u.browser.regtype, d, info->u.browser.interface_id, info->flags, info->u.browser.ForceMCast, (info->flags & kDNSServiceFlagsBackgroundTrafficClass) != 0, FoundInstance, info); if (err) { LogMsg("mDNS_StartBrowse returned %d for type %##s domain %##s", err, info->u.browser.regtype.c, d->c); freeL("browser_t/add_domain_to_browser", b); } else { b->next = info->u.browser.browsers; info->u.browser.browsers = b; #if APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR // Determine if this request should be promoted to use BLE triggered discovery. if (shouldUseBLE(info->u.browser.interface_id, 0, &info->u.browser.regtype, (domainname *) d)) { info->flags |= (kDNSServiceFlagsAutoTrigger | kDNSServiceFlagsIncludeAWDL); b->q.flags |= (kDNSServiceFlagsAutoTrigger | kDNSServiceFlagsIncludeAWDL); LogInfo("add_domain_to_browser: request promoted to use kDNSServiceFlagsAutoTrigger"); } #endif // APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR LogMcastQ(&b->q, info, q_start); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(info->u.browser.interface_id, &b->domain, info->flags)) { domainname tmp; ConstructServiceName(&tmp, NULL, &info->u.browser.regtype, &b->domain); LogDebug("add_domain_to_browser: calling external_start_browsing_for_service()"); external_start_browsing_for_service(info->u.browser.interface_id, &tmp, kDNSType_PTR, info->flags, info->process_id); } #endif } return err; } mDNSlocal void browse_termination_callback(request_state *info) { if (info->u.browser.default_domain) { // Stop the domain enumeration queries to discover the WAB legacy browse domains LogInfo("%3d: DNSServiceBrowse Cancel WAB PID[%d](%s)", info->sd, info->process_id, info->pid_name); uDNS_StopWABQueries(&mDNSStorage, UDNS_WAB_LBROWSE_QUERY); } while (info->u.browser.browsers) { browser_t *ptr = info->u.browser.browsers; #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(ptr->q.InterfaceID, &ptr->domain, ptr->q.flags)) { domainname tmp; ConstructServiceName(&tmp, NULL, &info->u.browser.regtype, &ptr->domain); LogInfo("browse_termination_callback: calling external_stop_browsing_for_service()"); external_stop_browsing_for_service(ptr->q.InterfaceID, &tmp, kDNSType_PTR, ptr->q.flags, info->process_id); } #endif LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceBrowse(%X, %d, \"" PRI_DM_NAME "\") STOP PID[%d](" PUB_S ")", info->request_id, info->flags, info->interfaceIndex, DM_NAME_PARAM(&ptr->q.qname), info->process_id, info->pid_name); info->u.browser.browsers = ptr->next; mDNS_StopBrowse(&mDNSStorage, &ptr->q); // no need to error-check result LogMcastQ(&ptr->q, info, q_stop); freeL("browser_t/browse_termination_callback", ptr); } } mDNSlocal void udsserver_automatic_browse_domain_changed(const DNameListElem *const d, const mDNSBool add) { request_state *request; debugf("udsserver_automatic_browse_domain_changed: %s default browse domain %##s", add ? "Adding" : "Removing", d->name.c); for (request = all_requests; request; request = request->next) { if (request->terminate != browse_termination_callback) continue; // Not a browse operation if (!request->u.browser.default_domain) continue; // Not an auto-browse operation if (!d->uid || SystemUID(request->uid) || request->uid == d->uid) { browser_t **ptr = &request->u.browser.browsers; while (*ptr && !SameDomainName(&(*ptr)->domain, &d->name)) ptr = &(*ptr)->next; if (add) { // If we don't already have this domain in our list for this browse operation, add it now if (!*ptr) add_domain_to_browser(request, &d->name); else debugf("udsserver_automatic_browse_domain_changed %##s already in list, not re-adding", &d->name); } else { if (!*ptr) LogMsg("udsserver_automatic_browse_domain_changed ERROR %##s not found", &d->name); else { DNameListElem *p; for (p = AutoBrowseDomains; p; p=p->next) if (!p->uid || SystemUID(request->uid) || request->uid == p->uid) if (SameDomainName(&d->name, &p->name)) break; if (p) debugf("udsserver_automatic_browse_domain_changed %##s still in list, not removing", &d->name); else { browser_t *rem = *ptr; *ptr = (*ptr)->next; mDNS_StopQueryWithRemoves(&mDNSStorage, &rem->q); freeL("browser_t/udsserver_automatic_browse_domain_changed", rem); } } } } } } mDNSlocal void FreeARElemCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { (void)m; // unused if (result == mStatus_MemFree) { // On shutdown, mDNS_Close automatically deregisters all records // Since in this case no one has called DeregisterLocalOnlyDomainEnumPTR to cut the record // from the LocalDomainEnumRecords list, we do this here before we free the memory. // (This should actually no longer be necessary, now that we do the proper cleanup in // udsserver_exit. To confirm this, we'll log an error message if we do find a record that // hasn't been cut from the list yet. If these messages don't appear, we can delete this code.) ARListElem **ptr = &LocalDomainEnumRecords; while (*ptr && &(*ptr)->ar != rr) ptr = &(*ptr)->next; if (*ptr) { *ptr = (*ptr)->next; LogMsg("FreeARElemCallback: Have to cut %s", ARDisplayString(m, rr)); } mDNSPlatformMemFree(rr->RecordContext); } } // RegisterLocalOnlyDomainEnumPTR and DeregisterLocalOnlyDomainEnumPTR largely duplicate code in // "FoundDomain" in uDNS.c for creating and destroying these special mDNSInterface_LocalOnly records. // We may want to turn the common code into a subroutine. mDNSlocal void RegisterLocalOnlyDomainEnumPTR(mDNS *m, const domainname *d, int type) { // allocate/register legacy and non-legacy _browse PTR record mStatus err; ARListElem *ptr = (ARListElem *) mDNSPlatformMemAllocateClear(sizeof(*ptr)); debugf("Incrementing %s refcount for %##s", (type == mDNS_DomainTypeBrowse ) ? "browse domain " : (type == mDNS_DomainTypeRegistration ) ? "registration dom" : (type == mDNS_DomainTypeBrowseAutomatic) ? "automatic browse" : "?", d->c); mDNS_SetupResourceRecord(&ptr->ar, mDNSNULL, mDNSInterface_LocalOnly, kDNSType_PTR, 7200, kDNSRecordTypeShared, AuthRecordLocalOnly, FreeARElemCallback, ptr); MakeDomainNameFromDNSNameString(&ptr->ar.namestorage, mDNS_DomainTypeNames[type]); AppendDNSNameString (&ptr->ar.namestorage, "local"); AssignDomainName(&ptr->ar.resrec.rdata->u.name, d); err = mDNS_Register(m, &ptr->ar); if (err) { LogMsg("SetSCPrefsBrowseDomain: mDNS_Register returned error %d", err); mDNSPlatformMemFree(ptr); } else { ptr->next = LocalDomainEnumRecords; LocalDomainEnumRecords = ptr; } } mDNSlocal void DeregisterLocalOnlyDomainEnumPTR(mDNS *m, const domainname *d, int type) { ARListElem **ptr = &LocalDomainEnumRecords; domainname lhs; // left-hand side of PTR, for comparison debugf("Decrementing %s refcount for %##s", (type == mDNS_DomainTypeBrowse ) ? "browse domain " : (type == mDNS_DomainTypeRegistration ) ? "registration dom" : (type == mDNS_DomainTypeBrowseAutomatic) ? "automatic browse" : "?", d->c); MakeDomainNameFromDNSNameString(&lhs, mDNS_DomainTypeNames[type]); AppendDNSNameString (&lhs, "local"); while (*ptr) { if (SameDomainName(&(*ptr)->ar.resrec.rdata->u.name, d) && SameDomainName((*ptr)->ar.resrec.name, &lhs)) { ARListElem *rem = *ptr; *ptr = (*ptr)->next; mDNS_Deregister(m, &rem->ar); return; } else ptr = &(*ptr)->next; } } mDNSlocal void AddAutoBrowseDomain(const mDNSu32 uid, const domainname *const name) { DNameListElem *new = (DNameListElem *) mDNSPlatformMemAllocateClear(sizeof(*new)); if (!new) { LogMsg("ERROR: malloc"); return; } AssignDomainName(&new->name, name); new->uid = uid; new->next = AutoBrowseDomains; AutoBrowseDomains = new; udsserver_automatic_browse_domain_changed(new, mDNStrue); } mDNSlocal void RmvAutoBrowseDomain(const mDNSu32 uid, const domainname *const name) { DNameListElem **p = &AutoBrowseDomains; while (*p && (!SameDomainName(&(*p)->name, name) || (*p)->uid != uid)) p = &(*p)->next; if (!*p) LogMsg("RmvAutoBrowseDomain: Got remove event for domain %##s not in list", name->c); else { DNameListElem *ptr = *p; *p = ptr->next; udsserver_automatic_browse_domain_changed(ptr, mDNSfalse); mDNSPlatformMemFree(ptr); } } mDNSlocal void SetPrefsBrowseDomains(mDNS *m, DNameListElem *browseDomains, mDNSBool add) { DNameListElem *d; for (d = browseDomains; d; d = d->next) { if (add) { RegisterLocalOnlyDomainEnumPTR(m, &d->name, mDNS_DomainTypeBrowse); AddAutoBrowseDomain(d->uid, &d->name); } else { DeregisterLocalOnlyDomainEnumPTR(m, &d->name, mDNS_DomainTypeBrowse); RmvAutoBrowseDomain(d->uid, &d->name); } } } #if APPLE_OSX_mDNSResponder mDNSlocal void UpdateDeviceInfoRecord(mDNS *const m) { int num_autoname = 0; request_state *req; // Don't need to register the device info record for kDNSServiceInterfaceIndexLocalOnly registrations. for (req = all_requests; req; req = req->next) { if (req->terminate == regservice_termination_callback && req->u.servicereg.autoname && req->interfaceIndex != kDNSServiceInterfaceIndexLocalOnly) num_autoname++; } // If DeviceInfo record is currently registered, see if we need to deregister it if (m->DeviceInfo.resrec.RecordType != kDNSRecordTypeUnregistered) if (num_autoname == 0 || !SameDomainLabelCS(m->DeviceInfo.resrec.name->c, m->nicelabel.c)) { LogOperation("UpdateDeviceInfoRecord Deregister %##s", m->DeviceInfo.resrec.name); mDNS_Deregister(m, &m->DeviceInfo); } // If DeviceInfo record is not currently registered, see if we need to register it if (m->DeviceInfo.resrec.RecordType == kDNSRecordTypeUnregistered) if (num_autoname > 0) { mDNS_SetupResourceRecord(&m->DeviceInfo, mDNSNULL, mDNSNULL, kDNSType_TXT, kStandardTTL, kDNSRecordTypeAdvisory, AuthRecordAny, mDNSNULL, mDNSNULL); ConstructServiceName(&m->DeviceInfo.namestorage, &m->nicelabel, &DeviceInfoName, &localdomain); m->DeviceInfo.resrec.rdlength = initializeDeviceInfoTXT(m, m->DeviceInfo.resrec.rdata->u.data); LogOperation("UpdateDeviceInfoRecord Register %##s", m->DeviceInfo.resrec.name); mDNS_Register(m, &m->DeviceInfo); } } #else // APPLE_OSX_mDNSResponder mDNSlocal void UpdateDeviceInfoRecord(mDNS *const m) { (void)m; // unused } #endif // APPLE_OSX_mDNSResponder mDNSexport void udsserver_handle_configchange(mDNS *const m) { request_state *req; service_instance *ptr; DNameListElem *RegDomains = NULL; DNameListElem *BrowseDomains = NULL; DNameListElem *p; UpdateDeviceInfoRecord(m); // For autoname services, see if the default service name has changed, necessitating an automatic update for (req = all_requests; req; req = req->next) if (req->terminate == regservice_termination_callback) if (req->u.servicereg.autoname && !SameDomainLabelCS(req->u.servicereg.name.c, m->nicelabel.c)) { req->u.servicereg.name = m->nicelabel; for (ptr = req->u.servicereg.instances; ptr; ptr = ptr->next) { ptr->renameonmemfree = 1; if (ptr->clientnotified) SendServiceRemovalNotification(&ptr->srs); LogInfo("udsserver_handle_configchange: Calling deregister for Service %##s", ptr->srs.RR_PTR.resrec.name->c); if (mDNS_DeregisterService_drt(m, &ptr->srs, mDNS_Dereg_rapid)) regservice_callback(m, &ptr->srs, mStatus_MemFree); // If service deregistered already, we can re-register immediately } } // Let the platform layer get the current DNS information mDNS_Lock(m); mDNSPlatformSetDNSConfig(mDNSfalse, mDNSfalse, mDNSNULL, &RegDomains, &BrowseDomains, mDNSfalse); mDNS_Unlock(m); // Any automatic registration domains are also implicitly automatic browsing domains if (RegDomains) SetPrefsBrowseDomains(m, RegDomains, mDNStrue); // Add the new list first if (AutoRegistrationDomains) SetPrefsBrowseDomains(m, AutoRegistrationDomains, mDNSfalse); // Then clear the old list // Add any new domains not already in our AutoRegistrationDomains list for (p=RegDomains; p; p=p->next) { DNameListElem **pp = &AutoRegistrationDomains; while (*pp && ((*pp)->uid != p->uid || !SameDomainName(&(*pp)->name, &p->name))) pp = &(*pp)->next; if (!*pp) // If not found in our existing list, this is a new default registration domain { RegisterLocalOnlyDomainEnumPTR(m, &p->name, mDNS_DomainTypeRegistration); udsserver_default_reg_domain_changed(p, mDNStrue); } else // else found same domainname in both old and new lists, so no change, just delete old copy { DNameListElem *del = *pp; *pp = (*pp)->next; mDNSPlatformMemFree(del); } } // Delete any domains in our old AutoRegistrationDomains list that are now gone while (AutoRegistrationDomains) { DNameListElem *del = AutoRegistrationDomains; AutoRegistrationDomains = AutoRegistrationDomains->next; // Cut record from list FIRST, DeregisterLocalOnlyDomainEnumPTR(m, &del->name, mDNS_DomainTypeRegistration); udsserver_default_reg_domain_changed(del, mDNSfalse); // before calling udsserver_default_reg_domain_changed() mDNSPlatformMemFree(del); } // Now we have our new updated automatic registration domain list AutoRegistrationDomains = RegDomains; // Add new browse domains to internal list if (BrowseDomains) SetPrefsBrowseDomains(m, BrowseDomains, mDNStrue); // Remove old browse domains from internal list if (SCPrefBrowseDomains) { SetPrefsBrowseDomains(m, SCPrefBrowseDomains, mDNSfalse); while (SCPrefBrowseDomains) { DNameListElem *fptr = SCPrefBrowseDomains; SCPrefBrowseDomains = SCPrefBrowseDomains->next; mDNSPlatformMemFree(fptr); } } // Replace the old browse domains array with the new array SCPrefBrowseDomains = BrowseDomains; } mDNSlocal void AutomaticBrowseDomainChange(mDNS *const m, DNSQuestion *q, const ResourceRecord *const answer, QC_result AddRecord) { (void)m; // unused; (void)q; // unused LogOperation("AutomaticBrowseDomainChange: %s automatic browse domain %##s", AddRecord ? "Adding" : "Removing", answer->rdata->u.name.c); if (AddRecord) AddAutoBrowseDomain(0, &answer->rdata->u.name); else RmvAutoBrowseDomain(0, &answer->rdata->u.name); } mDNSlocal mStatus _handle_browse_request_start(request_state *request, const char * domain) { domainname d; mStatus err = mStatus_NoError; request->terminate = browse_termination_callback; if (domain[0]) { if (!MakeDomainNameFromDNSNameString(&d, domain)) return(mStatus_BadParamErr); err = add_domain_to_browser(request, &d); } else { DNameListElem *sdom; for (sdom = AutoBrowseDomains; sdom; sdom = sdom->next) if (!sdom->uid || SystemUID(request->uid) || request->uid == sdom->uid) { err = add_domain_to_browser(request, &sdom->name); if (err) { if (SameDomainName(&sdom->name, &localdomain)) break; else err = mStatus_NoError; // suppress errors for non-local "default" domains } } } return(err); } #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal void _return_browse_request_error(request_state *request, mStatus error) { reply_state *rep; GenerateBrowseReply(NULL, 0, request, &rep, browse_reply_op, 0, error); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceBrowse _return_browse_request_error: error (%d)", request->request_id, error); append_reply(request, rep); } mDNSlocal mStatus _handle_browse_request_with_trust(request_state *request, const char * domain) { mStatus err; if (audit_token_to_pid(request->audit_token) == 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_WARNING, "[R%u] _handle_browse_request_with_trust: no audit token for pid(%s %d)", request->request_id, request->pid_name, request->process_id); err = _handle_browse_request_start(request, domain); } else { char typestr[MAX_ESCAPED_DOMAIN_NAME]; typestr[0] = 0; (void)ConvertDomainNameToCString(&request->u.browser.regtype, typestr); mdns_trust_flags_t flags = mdns_trust_flags_none; mdns_trust_status_t status = mdns_trust_check_bonjour(request->audit_token, typestr, &flags); switch (status) { case mdns_trust_status_denied: case mdns_trust_status_pending: { mdns_trust_t trust = mdns_trust_create(request->audit_token, typestr, flags); if (!trust ) { err = mStatus_NoMemoryErr; goto exit; } size_t len = strlen(domain) + 1; void * context = mallocL("context/_handle_browse_request_with_trust", len); if (!context) { my_perror("ERROR: mallocL context/_handle_browse_request_with_trust"); mdns_release(trust); err = mStatus_NoMemoryErr; goto exit; } memcpy(context, domain, len); mdns_trust_set_context(trust, context); mdns_trust_set_queue(trust, _get_trust_results_dispatch_queue()); mdns_trust_set_event_handler(trust, ^(mdns_trust_event_t event, mdns_trust_status_t update) { if (event == mdns_trust_event_result) { mStatus error = (update != mdns_trust_status_granted) ? mStatus_PolicyDenied : mStatus_NoError; KQueueLock(); const char * _domain = mdns_trust_get_context(trust); if (_domain) { if (!error) { error = _handle_browse_request_start(request, _domain); // No context means the request was canceled before we got here } if (error) // (not else if) Always check for error result { _return_browse_request_error(request, error); } } KQueueUnlock("_handle_browse_request_with_trust"); } }); request->trust = trust; mdns_trust_activate(trust); err = mStatus_NoError; break; } case mdns_trust_status_no_entitlement: err = mStatus_NoAuth; break; case mdns_trust_status_granted: err = _handle_browse_request_start(request, domain); break; default: err = mStatus_UnknownErr; break; } } exit: return err; } #endif // TRUST_ENFORCEMENT mDNSlocal mStatus handle_browse_request(request_state *request) { // Note that regtype may include a trailing subtype char regtype[MAX_ESCAPED_DOMAIN_NAME], domain[MAX_ESCAPED_DOMAIN_NAME]; domainname typedn, temp; mDNSs32 NumSubTypes; mStatus err = mStatus_NoError; DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); mDNSu32 interfaceIndex = get_uint32(&request->msgptr, request->msgend); mDNSInterfaceID InterfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, interfaceIndex); // The browse is scoped to a specific interface index, but the // interface is not currently in our list. if (interfaceIndex && !InterfaceID) { // If it's one of the specially defined inteface index values, just return an error. if (PreDefinedInterfaceIndex(interfaceIndex)) { LogInfo("handle_browse_request: bad interfaceIndex %d", interfaceIndex); return(mStatus_BadParamErr); } // Otherwise, use the specified interface index value and the browse will // be applied to that interface when it comes up. InterfaceID = (mDNSInterfaceID)(uintptr_t)interfaceIndex; LogInfo("handle_browse_request: browse pending for interface index %d", interfaceIndex); } if (get_string(&request->msgptr, request->msgend, regtype, sizeof(regtype)) < 0 || get_string(&request->msgptr, request->msgend, domain, sizeof(domain )) < 0) return(mStatus_BadParamErr); if (!request->msgptr) { LogMsg("%3d: DNSServiceBrowse(unreadable parameters)", request->sd); return(mStatus_BadParamErr); } request->flags = flags; request->interfaceIndex = interfaceIndex; typedn.c[0] = 0; NumSubTypes = ChopSubTypes(regtype); // Note: Modifies regtype string to remove trailing subtypes if (NumSubTypes < 0 || NumSubTypes > 1) return(mStatus_BadParamErr); if (NumSubTypes == 1) { if (!AppendDNSNameString(&typedn, regtype + strlen(regtype) + 1)) return(mStatus_BadParamErr); } if (!regtype[0] || !AppendDNSNameString(&typedn, regtype)) return(mStatus_BadParamErr); if (!MakeDomainNameFromDNSNameString(&temp, regtype)) return(mStatus_BadParamErr); // For over-long service types, we only allow domain "local" if (temp.c[0] > 15 && domain[0] == 0) mDNSPlatformStrLCopy(domain, "local.", sizeof(domain)); // Set up browser info request->u.browser.ForceMCast = (flags & kDNSServiceFlagsForceMulticast) != 0; request->u.browser.interface_id = InterfaceID; AssignDomainName(&request->u.browser.regtype, &typedn); request->u.browser.default_domain = !domain[0]; request->u.browser.browsers = NULL; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceBrowse(%X, %d, \"" PRI_DM_NAME "\", \"" PRI_S "\") START PID[%d](" PUB_S ")", request->request_id, request->flags, interfaceIndex, DM_NAME_PARAM(&request->u.browser.regtype), domain, request->process_id, request->pid_name); if (request->u.browser.default_domain) { // Start the domain enumeration queries to discover the WAB browse domains LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceBrowse Start WAB PID[%d](" PUB_S ")", request->request_id, request->process_id, request->pid_name); uDNS_StartWABQueries(&mDNSStorage, UDNS_WAB_LBROWSE_QUERY); } // We need to unconditionally set request->terminate, because even if we didn't successfully // start any browses right now, subsequent configuration changes may cause successful // browses to be added, and we'll need to cancel them before freeing this memory. request->terminate = NULL; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) domainname d; if (!MakeDomainNameFromDNSNameString(&d, domain)) return(mStatus_BadParamErr); if (os_feature_enabled(mDNSResponder, bonjour_privacy) && (request->u.browser.default_domain || IsLocalDomain(&d) || request->u.browser.ForceMCast)) { err = _handle_browse_request_with_trust(request, domain); } else { err = _handle_browse_request_start(request, domain); } #else err = _handle_browse_request_start(request, domain); #endif return(err); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceResolve #endif mDNSlocal void resolve_termination_callback(request_state *request) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceResolve(%X, %d, \"" PRI_DM_NAME "\") STOP PID[%d](" PUB_S ")", request->request_id, request->flags, request->interfaceIndex, DM_NAME_PARAM(&request->u.resolve.qtxt.qname), request->process_id, request->pid_name); mDNS_StopQuery(&mDNSStorage, &request->u.resolve.qtxt); mDNS_StopQuery(&mDNSStorage, &request->u.resolve.qsrv); LogMcastQ(&request->u.resolve.qsrv, request, q_stop); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (request->u.resolve.external_advertise) { external_stop_resolving_service(request->u.resolve.qsrv.InterfaceID, &request->u.resolve.qsrv.qname, request->flags, request->process_id); } #endif } typedef struct { char regtype[MAX_ESCAPED_DOMAIN_NAME]; domainname fqdn; mDNSInterfaceID InterfaceID; } _resolve_start_params_t; mDNSlocal mStatus _handle_resolve_request_start(request_state *request, const _resolve_start_params_t * const params) { mStatus err; err = mDNS_StartQuery(&mDNSStorage, &request->u.resolve.qsrv); if (!err) { err = mDNS_StartQuery(&mDNSStorage, &request->u.resolve.qtxt); if (err) { mDNS_StopQuery(&mDNSStorage, &request->u.resolve.qsrv); } else { request->terminate = resolve_termination_callback; LogMcastQ(&request->u.resolve.qsrv, request, q_start); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) if (callExternalHelpers(params->InterfaceID, ¶ms->fqdn, request->flags)) { request->u.resolve.external_advertise = mDNStrue; LogInfo("handle_resolve_request: calling external_start_resolving_service()"); external_start_resolving_service(params->InterfaceID, ¶ms->fqdn, request->flags, request->process_id); } #else (void)params; #endif } } return err; } mDNSlocal void resolve_result_callback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) { size_t len = 0; char fullname[MAX_ESCAPED_DOMAIN_NAME], target[MAX_ESCAPED_DOMAIN_NAME] = "0"; char *data; reply_state *rep; request_state *req = question->QuestionContext; const DNSServiceErrorType error = (answer->RecordType == kDNSRecordTypePacketNegative) ? kDNSServiceErr_NoSuchRecord : kDNSServiceErr_NoError; (void)m; // Unused LogOperation("%3d: DNSServiceResolve(%##s) %s interface %d: %s", req->sd, question->qname.c, AddRecord ? "ADD" : "RMV", mDNSPlatformInterfaceIndexfromInterfaceID(m, answer->InterfaceID, mDNSfalse), RRDisplayString(m, answer)); if (!AddRecord) { if (req->u.resolve.srv == answer) req->u.resolve.srv = mDNSNULL; if (req->u.resolve.txt == answer) req->u.resolve.txt = mDNSNULL; return; } if (answer->rrtype == kDNSType_SRV) req->u.resolve.srv = answer; if (answer->rrtype == kDNSType_TXT) req->u.resolve.txt = answer; if (!req->u.resolve.txt || !req->u.resolve.srv) return; // only deliver result to client if we have both answers ConvertDomainNameToCString(answer->name, fullname); if (answer->RecordType != kDNSRecordTypePacketNegative) ConvertDomainNameToCString(&req->u.resolve.srv->rdata->u.srv.target, target); // calculate reply length len += sizeof(DNSServiceFlags); len += sizeof(mDNSu32); // interface index len += sizeof(DNSServiceErrorType); len += strlen(fullname) + 1; len += strlen(target) + 1; len += 2 * sizeof(mDNSu16); // port, txtLen len += req->u.resolve.txt->rdlength; // allocate/init reply header rep = create_reply(resolve_reply_op, len, req); rep->rhdr->flags = dnssd_htonl(0); rep->rhdr->ifi = dnssd_htonl(mDNSPlatformInterfaceIndexfromInterfaceID(m, answer->InterfaceID, mDNSfalse)); rep->rhdr->error = dnssd_htonl(error); data = (char *)&rep->rhdr[1]; // write reply data to message put_string(fullname, &data); put_string(target, &data); *data++ = req->u.resolve.srv->rdata->u.srv.port.b[0]; *data++ = req->u.resolve.srv->rdata->u.srv.port.b[1]; put_uint16(req->u.resolve.txt->rdlength, &data); put_rdata (req->u.resolve.txt->rdlength, req->u.resolve.txt->rdata->u.data, &data); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] DNSServiceResolve(" PRI_S ") RESULT " PRI_S ":%d", req->request_id, mDNSVal16(question->TargetQID), fullname, target, mDNSVal16(req->u.resolve.srv->rdata->u.srv.port)); append_reply(req, rep); } #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal void _return_resolve_request_error(request_state * request, mStatus error) { size_t len; char * emptystr = "\0"; char * data; reply_state *rep; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSServiceResolve _return_resolve_request_error: error(%d)", request->request_id, error); // calculate reply length len = sizeof(DNSServiceFlags); len += sizeof(mDNSu32); // interface index len += sizeof(DNSServiceErrorType); len += 2; // name, target len += 2 * sizeof(mDNSu16); // port, txtLen len += 0; //req->u.resolve.txt->rdlength; rep = create_reply(resolve_reply_op, len, request); rep->rhdr->flags = 0; rep->rhdr->ifi = 0; rep->rhdr->error = dnssd_htonl(error); data = (char *)&rep->rhdr[1]; // write reply data to message put_string(emptystr, &data); // name put_string(emptystr, &data); // target put_uint16(0, &data); // port put_uint16(0, &data); // txtLen append_reply(request, rep); } mDNSlocal mStatus _handle_resolve_request_with_trust(request_state *request, const _resolve_start_params_t * const params) { mStatus err; if (audit_token_to_pid(request->audit_token) == 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_WARNING, "[R%u] _handle_resolve_request_with_trust: no audit token for pid(%s %d)", request->request_id, request->pid_name, request->process_id); err = _handle_resolve_request_start(request, params); } else { mdns_trust_flags_t flags = mdns_trust_flags_none; mdns_trust_status_t status = mdns_trust_check_bonjour(request->audit_token, params->regtype, &flags); switch (status) { case mdns_trust_status_denied: case mdns_trust_status_pending: { mdns_trust_t trust = mdns_trust_create(request->audit_token, params->regtype, flags); if (!trust ) { err = mStatus_NoMemoryErr; goto exit; } void * context = mallocL("context/_handle_resolve_request_with_trust", sizeof(_resolve_start_params_t)); if (!context) { my_perror("ERROR: mallocL context/_handle_resolve_request_with_trust"); mdns_release(trust); err = mStatus_NoMemoryErr; goto exit; } memcpy(context, params, sizeof(_resolve_start_params_t)); mdns_trust_set_context(trust, context); mdns_trust_set_queue(trust, _get_trust_results_dispatch_queue()); mdns_trust_set_event_handler(trust, ^(mdns_trust_event_t event, mdns_trust_status_t update) { if (event == mdns_trust_event_result) { mStatus error = (update != mdns_trust_status_granted) ? mStatus_PolicyDenied : mStatus_NoError; KQueueLock(); _resolve_start_params_t * _params = mdns_trust_get_context(trust); if (_params) { if (!error) { error = _handle_resolve_request_start(request, _params); // No context means the request was canceled before we got here } if (error) // (not else if) Always check for error result { _return_resolve_request_error(request, error); } } KQueueUnlock("_handle_resolve_request_with_trust"); } }); request->trust = trust; mdns_trust_activate(trust); err = mStatus_NoError; break; } case mdns_trust_status_no_entitlement: err = mStatus_NoAuth; break; case mdns_trust_status_granted: err = _handle_resolve_request_start(request, params); break; default: err = mStatus_UnknownErr; break; } } exit: return err; } #endif // TRUST_ENFORCEMENT mDNSlocal mStatus handle_resolve_request(request_state *request) { char name[256], domain[MAX_ESCAPED_DOMAIN_NAME]; _resolve_start_params_t params; mStatus err; // extract the data from the message DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); mDNSu32 interfaceIndex = get_uint32(&request->msgptr, request->msgend); // Map kDNSServiceInterfaceIndexP2P to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P // flag set so that the resolve will run over P2P interfaces that are not yet created. if (interfaceIndex == kDNSServiceInterfaceIndexP2P) { LogOperation("handle_resolve_request: mapping kDNSServiceInterfaceIndexP2P to kDNSServiceInterfaceIndexAny + kDNSServiceFlagsIncludeP2P"); flags |= kDNSServiceFlagsIncludeP2P; interfaceIndex = kDNSServiceInterfaceIndexAny; } params.InterfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, interfaceIndex); // The operation is scoped to a specific interface index, but the // interface is not currently in our list. if (interfaceIndex && !params.InterfaceID) { // If it's one of the specially defined inteface index values, just return an error. if (PreDefinedInterfaceIndex(interfaceIndex)) { LogInfo("handle_resolve_request: bad interfaceIndex %d", interfaceIndex); return(mStatus_BadParamErr); } // Otherwise, use the specified interface index value and the operation will // be applied to that interface when it comes up. params.InterfaceID = (mDNSInterfaceID)(uintptr_t)interfaceIndex; LogInfo("handle_resolve_request: resolve pending for interface index %d", interfaceIndex); } if (get_string(&request->msgptr, request->msgend, name, sizeof(name )) < 0 || get_string(&request->msgptr, request->msgend, params.regtype, sizeof(params.regtype)) < 0 || get_string(&request->msgptr, request->msgend, domain, sizeof(domain )) < 0) { LogMsg("ERROR: handle_resolve_request - Couldn't read name/regtype/domain"); return(mStatus_BadParamErr); } if (!request->msgptr) { LogMsg("%3d: DNSServiceResolve(unreadable parameters)", request->sd); return(mStatus_BadParamErr); } if (build_domainname_from_strings(¶ms.fqdn, name, params.regtype, domain) < 0) { LogMsg("ERROR: handle_resolve_request bad “%s” “%s” “%s”", name, params.regtype, domain); return(mStatus_BadParamErr); } mDNSPlatformMemZero(&request->u.resolve, sizeof(request->u.resolve)); #if APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR // Determine if this request should be promoted to use BLE triggered discovery. if (shouldUseBLE(InterfaceID, 0, (domainname *)SkipLeadingLabels(&fqdn, 1), &fqdn)) { flags |= (kDNSServiceFlagsAutoTrigger | kDNSServiceFlagsIncludeAWDL); LogInfo("handle_resolve_request: request promoted to use kDNSServiceFlagsAutoTrigger"); } #endif // APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR request->flags = flags; request->interfaceIndex = interfaceIndex; // format questions request->u.resolve.qsrv.InterfaceID = params.InterfaceID; request->u.resolve.qsrv.flags = flags; AssignDomainName(&request->u.resolve.qsrv.qname, ¶ms.fqdn); request->u.resolve.qsrv.qtype = kDNSType_SRV; request->u.resolve.qsrv.qclass = kDNSClass_IN; request->u.resolve.qsrv.LongLived = (flags & kDNSServiceFlagsLongLivedQuery ) != 0; request->u.resolve.qsrv.ExpectUnique = mDNStrue; request->u.resolve.qsrv.ForceMCast = (flags & kDNSServiceFlagsForceMulticast ) != 0; request->u.resolve.qsrv.ReturnIntermed = (flags & kDNSServiceFlagsReturnIntermediates) != 0; request->u.resolve.qsrv.SuppressUnusable = mDNSfalse; request->u.resolve.qsrv.AppendSearchDomains = 0; request->u.resolve.qsrv.TimeoutQuestion = 0; request->u.resolve.qsrv.WakeOnResolve = (flags & kDNSServiceFlagsWakeOnResolve) != 0; request->u.resolve.qsrv.UseBackgroundTraffic = (flags & kDNSServiceFlagsBackgroundTrafficClass) != 0; request->u.resolve.qsrv.ProxyQuestion = 0; request->u.resolve.qsrv.pid = request->process_id; request->u.resolve.qsrv.euid = request->uid; request->u.resolve.qsrv.QuestionCallback = resolve_result_callback; request->u.resolve.qsrv.QuestionContext = request; request->u.resolve.qtxt.InterfaceID = params.InterfaceID; request->u.resolve.qtxt.flags = flags; AssignDomainName(&request->u.resolve.qtxt.qname, ¶ms.fqdn); request->u.resolve.qtxt.qtype = kDNSType_TXT; request->u.resolve.qtxt.qclass = kDNSClass_IN; request->u.resolve.qtxt.LongLived = (flags & kDNSServiceFlagsLongLivedQuery ) != 0; request->u.resolve.qtxt.ExpectUnique = mDNStrue; request->u.resolve.qtxt.ForceMCast = (flags & kDNSServiceFlagsForceMulticast ) != 0; request->u.resolve.qtxt.ReturnIntermed = (flags & kDNSServiceFlagsReturnIntermediates) != 0; request->u.resolve.qtxt.SuppressUnusable = mDNSfalse; request->u.resolve.qtxt.AppendSearchDomains = 0; request->u.resolve.qtxt.TimeoutQuestion = 0; request->u.resolve.qtxt.WakeOnResolve = 0; request->u.resolve.qtxt.UseBackgroundTraffic = (flags & kDNSServiceFlagsBackgroundTrafficClass) != 0; request->u.resolve.qtxt.ProxyQuestion = 0; request->u.resolve.qtxt.pid = request->process_id; request->u.resolve.qtxt.euid = request->uid; request->u.resolve.qtxt.QuestionCallback = resolve_result_callback; request->u.resolve.qtxt.QuestionContext = request; request->u.resolve.ReportTime = NonZeroTime(mDNS_TimeNow(&mDNSStorage) + 130 * mDNSPlatformOneSecond); request->u.resolve.external_advertise = mDNSfalse; #if 0 if (!AuthorizedDomain(request, &fqdn, AutoBrowseDomains)) return(mStatus_NoError); #endif // ask the questions LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceResolve(%X, %d, \"" PRI_DM_NAME "\") START PID[%d](" PUB_S ")", request->request_id, flags, interfaceIndex, DM_NAME_PARAM(&request->u.resolve.qsrv.qname), request->process_id, request->pid_name); request->terminate = NULL; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) domainname d; if (!MakeDomainNameFromDNSNameString(&d, domain)) return(mStatus_BadParamErr); if (os_feature_enabled(mDNSResponder, bonjour_privacy) && (IsLocalDomain(&d) || request->u.resolve.qsrv.ForceMCast)) { err = _handle_resolve_request_with_trust(request, ¶ms); } else { err = _handle_resolve_request_start(request, ¶ms); } #else err = _handle_resolve_request_start(request, ¶ms); #endif return(err); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceQueryRecord #endif mDNSlocal void queryrecord_result_reply(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord, DNSServiceErrorType error, void *context) { char name[MAX_ESCAPED_DOMAIN_NAME]; size_t len; DNSServiceFlags flags = 0; reply_state *rep; char *data; request_state *req = (request_state *)context; const char *dnssec_result_description = ""; ConvertDomainNameToCString(answer->name, name); #if MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) if (question->DNSSECStatus.enable_dnssec) { if (answer->dnssec_result == dnssec_secure) { flags |= kDNSServiceFlagsSecure; dnssec_result_description = ", DNSSEC_Secure"; } else if (answer->dnssec_result == dnssec_insecure) { flags |= kDNSServiceFlagsInsecure; dnssec_result_description = ", DNSSEC_Insecure"; } else if (answer->dnssec_result == dnssec_bogus) { flags |= kDNSServiceFlagsBogus; dnssec_result_description = ", DNSSEC_Bogus"; } else if (answer->dnssec_result == dnssec_indeterminate) { flags |= kDNSServiceFlagsIndeterminate; dnssec_result_description = ", DNSSEC_Indeterminate"; } } else if (question->DNSSECStatus.tried_dnssec_but_unsigned) { // handle the case where we restart the question without the DNSSEC while the user requires DNSSEC result, for // some reason we failed to get DNSSEC records. In which case, even if we go back to normal query, we should pass // the DNSSEC result flags |= kDNSServiceFlagsInsecure; dnssec_result_description = ", DNSSEC_Insecure"; } #endif // MDNSRESPONDER_SUPPORTS(APPLE, DNSSECv2) LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u->Q%u] DNSService" PUB_S "(" PRI_DM_NAME ", " PUB_S ") RESULT " PUB_S " interface %d: (" PUB_S PUB_S ")" PRI_S, req->request_id, mDNSVal16(question->TargetQID), req->hdr.op == query_request ? "QueryRecord" : "GetAddrInfo", DM_NAME_PARAM(&question->qname), DNSTypeName(question->qtype), AddRecord ? "ADD" : "RMV", mDNSPlatformInterfaceIndexfromInterfaceID(m, answer->InterfaceID, mDNSfalse), MortalityDisplayString(answer->mortality), dnssec_result_description, RRDisplayString(m, answer)); len = sizeof(DNSServiceFlags); // calculate reply data length len += sizeof(mDNSu32); // interface index len += sizeof(DNSServiceErrorType); len += strlen(name) + 1; len += 3 * sizeof(mDNSu16); // type, class, rdlen len += answer->rdlength; len += sizeof(mDNSu32); // TTL rep = create_reply(req->hdr.op == query_request ? query_reply_op : addrinfo_reply_op, len, req); if (AddRecord) flags |= kDNSServiceFlagsAdd; if (answer->mortality == Mortality_Ghost) flags |= kDNSServiceFlagsExpiredAnswer; if (!question->InitialCacheMiss) flags |= kDNSServiceFlagAnsweredFromCache; rep->rhdr->flags = dnssd_htonl(flags); // Call mDNSPlatformInterfaceIndexfromInterfaceID, but suppressNetworkChange (last argument). Otherwise, if the // InterfaceID is not valid, then it simulates a "NetworkChanged" which in turn makes questions // to be stopped and started including *this* one. Normally the InterfaceID is valid. But when we // are using the /etc/hosts entries to answer a question, the InterfaceID may not be known to the // mDNS core . Eventually, we should remove the calls to "NetworkChanged" in // mDNSPlatformInterfaceIndexfromInterfaceID when it can't find InterfaceID as ResourceRecords // should not have existed to answer this question if the corresponding interface is not valid. rep->rhdr->ifi = dnssd_htonl(mDNSPlatformInterfaceIndexfromInterfaceID(m, answer->InterfaceID, mDNStrue)); rep->rhdr->error = dnssd_htonl(error); data = (char *)&rep->rhdr[1]; put_string(name, &data); put_uint16(answer->rrtype, &data); put_uint16(answer->rrclass, &data); put_uint16(answer->rdlength, &data); // We need to use putRData here instead of the crude put_rdata function, because the crude put_rdata // function just does a blind memory copy without regard to structures that may have holes in them. if (answer->rdlength) if (!putRData(mDNSNULL, (mDNSu8 *)data, (mDNSu8 *)rep->rhdr + len, answer)) LogMsg("queryrecord_result_reply putRData failed %d", (mDNSu8 *)rep->rhdr + len - (mDNSu8 *)data); data += answer->rdlength; put_uint32(AddRecord ? answer->rroriginalttl : 0, &data); append_reply(req, rep); } mDNSlocal void queryrecord_termination_callback(request_state *request) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSServiceQueryRecord(%X, %d, " PRI_DM_NAME ", " PUB_S ") STOP PID[%d](" PUB_S ")", request->request_id, request->flags, request->interfaceIndex, DM_NAME_PARAM(QueryRecordClientRequestGetQName(&request->u.queryrecord)), DNSTypeName(QueryRecordClientRequestGetType(&request->u.queryrecord)), request->process_id, request->pid_name); QueryRecordClientRequestStop(&request->u.queryrecord); } typedef struct { char qname[MAX_ESCAPED_DOMAIN_NAME]; mDNSu32 interfaceIndex; DNSServiceFlags flags; mDNSu16 qtype; mDNSu16 qclass; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool require_privacy; #endif } _queryrecord_start_params_t; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) && MDNSRESPONDER_SUPPORTS(APPLE, IPC_TLV) mDNSlocal const mDNSu8 * ipc_tlv_get_resolver_config_plist_data(const mDNSu8 *const start, const mDNSu8 *const end, size_t *outLen) { size_t len = 0; const mDNSu8 *value = NULL; mdns_tlv16_get_value(start, end, IPC_TLV_TYPE_RESOLVER_CONFIG_PLIST_DATA, &len, &value, NULL); if (outLen) { *outLen = len; } return value; } mDNSlocal mDNSBool ipc_tlv_get_require_privacy(const mDNSu8 *const start, const mDNSu8 *const end) { size_t len = 0; const mDNSu8 *value = NULL; mdns_tlv16_get_value(start, end, IPC_TLV_TYPE_REQUIRE_PRIVACY, &len, &value, NULL); return ((len == 1) && (*value != 0)) ? mDNStrue : mDNSfalse; } #endif mDNSlocal mStatus _handle_queryrecord_request_start(request_state *request, const _queryrecord_start_params_t * const params) { mStatus err; request->terminate = queryrecord_termination_callback; QueryRecordClientRequestParams queryParams; QueryRecordClientRequestParamsInit(&queryParams); queryParams.requestID = request->request_id; queryParams.qnameStr = params->qname; queryParams.interfaceIndex = params->interfaceIndex; queryParams.flags = params->flags; queryParams.qtype = params->qtype; queryParams.qclass = params->qclass; queryParams.effectivePID = request->validUUID ? 0 : request->process_id; queryParams.effectiveUUID = request->validUUID ? request->uuid : mDNSNULL; queryParams.peerUID = request->uid; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) queryParams.needEncryption = params->require_privacy ? mDNStrue : mDNSfalse; queryParams.customID = request->custom_service_id; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) queryParams.peerAuditToken = &request->audit_token; #endif err = QueryRecordClientRequestStart(&request->u.queryrecord, &queryParams, queryrecord_result_reply, request); return err; } #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal void _return_queryrecord_request_error(request_state * request, mStatus error) { size_t len; char * emptystr = "\0"; char * data; reply_state *rep; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSService" PUB_S " _return_queryrecord_request_error: error(%d)", request->request_id, request->hdr.op == query_request ? "QueryRecord" : "GetAddrInfo", error); len = sizeof(DNSServiceFlags); // calculate reply data length len += sizeof(mDNSu32); // interface index len += sizeof(DNSServiceErrorType); len += strlen(emptystr) + 1; len += 3 * sizeof(mDNSu16); // type, class, rdlen len += 0;//answer->rdlength; len += sizeof(mDNSu32); // TTL rep = create_reply(request->hdr.op == query_request ? query_reply_op : addrinfo_reply_op, len, request); rep->rhdr->flags = 0; rep->rhdr->ifi = 0; rep->rhdr->error = dnssd_htonl(error); data = (char *)&rep->rhdr[1]; put_string(emptystr, &data); put_uint16(0, &data); put_uint16(0, &data); put_uint16(0, &data); data += 0; put_uint32(0, &data); append_reply(request, rep); } mDNSlocal mStatus _handle_queryrecord_request_with_trust(request_state *request, const _queryrecord_start_params_t * const params) { mStatus err; if (audit_token_to_pid(request->audit_token) == 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_WARNING, "[R%u] _handle_queryrecord_request_with_trust: no audit token for pid(%s %d)", request->request_id, request->pid_name, request->process_id); err = _handle_queryrecord_request_start(request, params); } else { const char *service_ptr = NULL; char type_str[MAX_ESCAPED_DOMAIN_NAME] = ""; domainname query_name; if (MakeDomainNameFromDNSNameString(&query_name, params->qname)) { domainlabel name; domainname type, domain; bool good = DeconstructServiceName(&query_name, &name, &type, &domain); if (good) { ConvertDomainNameToCString(&type, type_str); service_ptr = type_str; } } mdns_trust_flags_t flags = mdns_trust_flags_none; mdns_trust_status_t status = mdns_trust_check_query(request->audit_token, params->qname, service_ptr, params->qtype, (params->flags & kDNSServiceFlagsForceMulticast) != 0, &flags); switch (status) { case mdns_trust_status_denied: case mdns_trust_status_pending: { mdns_trust_t trust = mdns_trust_create(request->audit_token, service_ptr, flags); if (!trust ) { err = mStatus_NoMemoryErr; goto exit; } void * context = mallocL("context/_handle_queryrecord_request_with_trust", sizeof(_queryrecord_start_params_t)); if (!context) { my_perror("ERROR: mallocL context/_handle_queryrecord_request_with_trust"); mdns_release(trust); err = mStatus_NoMemoryErr; goto exit; } memcpy(context, params, sizeof(_queryrecord_start_params_t)); mdns_trust_set_context(trust, context); mdns_trust_set_queue(trust, _get_trust_results_dispatch_queue()); mdns_trust_set_event_handler(trust, ^(mdns_trust_event_t event, mdns_trust_status_t update) { if (event == mdns_trust_event_result) { mStatus error = (update != mdns_trust_status_granted) ? mStatus_PolicyDenied : mStatus_NoError; KQueueLock(); _queryrecord_start_params_t * _params = mdns_trust_get_context(trust); if (_params) { if (!error) { error = _handle_queryrecord_request_start(request, _params); // No context means the request was canceled before we got here } if (error) // (not else if) Always check for error result { _return_queryrecord_request_error(request, error); } } KQueueUnlock("_handle_queryrecord_request_with_trust"); } }); request->trust = trust; mdns_trust_activate(trust); err = mStatus_NoError; break; } case mdns_trust_status_no_entitlement: err = mStatus_NoAuth; break; case mdns_trust_status_granted: err = _handle_queryrecord_request_start(request, params); break; default: err = mStatus_UnknownErr; break; } } exit: return err; } #endif // TRUST_ENFORCEMENT mDNSlocal mStatus handle_queryrecord_request(request_state *request) { mStatus err; _queryrecord_start_params_t params; params.flags = get_flags(&request->msgptr, request->msgend); params.interfaceIndex = get_uint32(&request->msgptr, request->msgend); if (get_string(&request->msgptr, request->msgend, params.qname, sizeof(params.qname)) < 0) { err = mStatus_BadParamErr; goto exit; } params.qtype = get_uint16(&request->msgptr, request->msgend); params.qclass = get_uint16(&request->msgptr, request->msgend); if (!request->msgptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceQueryRecord(unreadable parameters)", request->request_id); err = mStatus_BadParamErr; goto exit; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) params.require_privacy = mDNSfalse; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) && MDNSRESPONDER_SUPPORTS(APPLE, IPC_TLV) if (request->msgptr && (request->hdr.ipc_flags & IPC_FLAGS_TRAILING_TLVS)) { size_t len; const mDNSu8 *const start = (const mDNSu8 *)request->msgptr; const mDNSu8 *const end = (const mDNSu8 *)request->msgend; const mDNSu8 *const data = ipc_tlv_get_resolver_config_plist_data(start, end, &len); if (data) { request->custom_service_id = Querier_RegisterCustomDNSServiceWithPListData(data, len); } params.require_privacy = ipc_tlv_get_require_privacy(start, end); } #endif request->flags = params.flags; request->interfaceIndex = params.interfaceIndex; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceQueryRecord(%X, %d, " PRI_S ", " PUB_S ") START PID[%d](" PUB_S ")", request->request_id, request->flags, request->interfaceIndex, params.qname, DNSTypeName(params.qtype), request->process_id, request->pid_name); mDNSPlatformMemZero(&request->u.queryrecord, (mDNSu32)sizeof(request->u.queryrecord)); request->terminate = NULL; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (os_feature_enabled(mDNSResponder, bonjour_privacy)) { err = _handle_queryrecord_request_with_trust(request, ¶ms); } else { err = _handle_queryrecord_request_start(request, ¶ms); } #else err = _handle_queryrecord_request_start(request, ¶ms); #endif exit: return(err); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceEnumerateDomains #endif mDNSlocal reply_state *format_enumeration_reply(request_state *request, const char *domain, DNSServiceFlags flags, mDNSu32 ifi, DNSServiceErrorType err) { size_t len; reply_state *reply; char *data; len = sizeof(DNSServiceFlags); len += sizeof(mDNSu32); len += sizeof(DNSServiceErrorType); len += strlen(domain) + 1; reply = create_reply(enumeration_reply_op, len, request); reply->rhdr->flags = dnssd_htonl(flags); reply->rhdr->ifi = dnssd_htonl(ifi); reply->rhdr->error = dnssd_htonl(err); data = (char *)&reply->rhdr[1]; put_string(domain, &data); return reply; } mDNSlocal void enum_termination_callback(request_state *request) { // Stop the domain enumeration queries to discover the WAB Browse/Registration domains if (request->u.enumeration.flags & kDNSServiceFlagsRegistrationDomains) { LogInfo("%3d: DNSServiceEnumeration Cancel WAB Registration PID[%d](%s)", request->sd, request->process_id, request->pid_name); uDNS_StopWABQueries(&mDNSStorage, UDNS_WAB_REG_QUERY); } else { LogInfo("%3d: DNSServiceEnumeration Cancel WAB Browse PID[%d](%s)", request->sd, request->process_id, request->pid_name); uDNS_StopWABQueries(&mDNSStorage, UDNS_WAB_BROWSE_QUERY | UDNS_WAB_LBROWSE_QUERY); mDNS_StopGetDomains(&mDNSStorage, &request->u.enumeration.q_autoall); } mDNS_StopGetDomains(&mDNSStorage, &request->u.enumeration.q_all); mDNS_StopGetDomains(&mDNSStorage, &request->u.enumeration.q_default); } mDNSlocal void enum_result_callback(mDNS *const m, DNSQuestion *const question, const ResourceRecord *const answer, QC_result AddRecord) { char domain[MAX_ESCAPED_DOMAIN_NAME]; request_state *request = question->QuestionContext; DNSServiceFlags flags = 0; reply_state *reply; (void)m; // Unused if (answer->rrtype != kDNSType_PTR) return; #if 0 if (!AuthorizedDomain(request, &answer->rdata->u.name, request->u.enumeration.flags ? AutoRegistrationDomains : AutoBrowseDomains)) return; #endif // We only return add/remove events for the browse and registration lists // For the default browse and registration answers, we only give an "ADD" event if (question == &request->u.enumeration.q_default && !AddRecord) return; if (AddRecord) { flags |= kDNSServiceFlagsAdd; if (question == &request->u.enumeration.q_default) flags |= kDNSServiceFlagsDefault; } ConvertDomainNameToCString(&answer->rdata->u.name, domain); // Note that we do NOT propagate specific interface indexes to the client - for example, a domain we learn from // a machine's system preferences may be discovered on the LocalOnly interface, but should be browsed on the // network, so we just pass kDNSServiceInterfaceIndexAny reply = format_enumeration_reply(request, domain, flags, kDNSServiceInterfaceIndexAny, kDNSServiceErr_NoError); if (!reply) { LogMsg("ERROR: enum_result_callback, format_enumeration_reply"); return; } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d->Q%d] DNSServiceEnumerateDomains(%2.*s) RESULT " PUB_S ": " PRI_S, request->request_id, mDNSVal16(question->TargetQID), question->qname.c[0], &question->qname.c[1], AddRecord ? "ADD" : "RMV", domain); append_reply(request, reply); } mDNSlocal mStatus handle_enum_request(request_state *request) { mStatus err; DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); DNSServiceFlags reg = flags & kDNSServiceFlagsRegistrationDomains; mDNS_DomainType t_all = reg ? mDNS_DomainTypeRegistration : mDNS_DomainTypeBrowse; mDNS_DomainType t_default = reg ? mDNS_DomainTypeRegistrationDefault : mDNS_DomainTypeBrowseDefault; mDNSu32 interfaceIndex = get_uint32(&request->msgptr, request->msgend); mDNSInterfaceID InterfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, interfaceIndex); if (interfaceIndex && !InterfaceID) return(mStatus_BadParamErr); if (!request->msgptr) { LogMsg("%3d: DNSServiceEnumerateDomains(unreadable parameters)", request->sd); return(mStatus_BadParamErr); } request->flags = flags; request->interfaceIndex = interfaceIndex; // mark which kind of enumeration we're doing so that we know what domain enumeration queries to stop request->u.enumeration.flags = reg; // enumeration requires multiple questions, so we must link all the context pointers so that // necessary context can be reached from the callbacks request->u.enumeration.q_all.QuestionContext = request; request->u.enumeration.q_default.QuestionContext = request; if (!reg) request->u.enumeration.q_autoall.QuestionContext = request; // if the caller hasn't specified an explicit interface, we use local-only to get the system-wide list. if (!InterfaceID) InterfaceID = mDNSInterface_LocalOnly; // make the calls LogOperation("%3d: DNSServiceEnumerateDomains(%X=%s)", request->sd, flags, (flags & kDNSServiceFlagsBrowseDomains ) ? "kDNSServiceFlagsBrowseDomains" : (flags & kDNSServiceFlagsRegistrationDomains) ? "kDNSServiceFlagsRegistrationDomains" : "<>"); err = mDNS_GetDomains(&mDNSStorage, &request->u.enumeration.q_all, t_all, NULL, InterfaceID, enum_result_callback, request); if (!err) { err = mDNS_GetDomains(&mDNSStorage, &request->u.enumeration.q_default, t_default, NULL, InterfaceID, enum_result_callback, request); if (err) mDNS_StopGetDomains(&mDNSStorage, &request->u.enumeration.q_all); else if (!reg) { err = mDNS_GetDomains(&mDNSStorage, &request->u.enumeration.q_autoall, mDNS_DomainTypeBrowseAutomatic, NULL, InterfaceID, enum_result_callback, request); if (err) { mDNS_StopGetDomains(&mDNSStorage, &request->u.enumeration.q_all); mDNS_StopGetDomains(&mDNSStorage, &request->u.enumeration.q_default); } } if (!err) request->terminate = enum_termination_callback; } if (!err) { // Start the domain enumeration queries to discover the WAB Browse/Registration domains if (reg) { LogInfo("%3d: DNSServiceEnumerateDomains Start WAB Registration PID[%d](%s)", request->sd, request->process_id, request->pid_name); uDNS_StartWABQueries(&mDNSStorage, UDNS_WAB_REG_QUERY); } else { LogInfo("%3d: DNSServiceEnumerateDomains Start WAB Browse PID[%d](%s)", request->sd, request->process_id, request->pid_name); uDNS_StartWABQueries(&mDNSStorage, UDNS_WAB_BROWSE_QUERY | UDNS_WAB_LBROWSE_QUERY); } } return(err); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceReconfirmRecord & Misc #endif mDNSlocal mStatus handle_reconfirm_request(request_state *request) { mStatus status = mStatus_BadParamErr; AuthRecord *rr = read_rr_from_ipc_msg(request, 0, 0); if (rr) { status = mDNS_ReconfirmByValue(&mDNSStorage, &rr->resrec); LogOperation( (status == mStatus_NoError) ? "%3d: DNSServiceReconfirmRecord(%s) interface %d initiated PID[%d](%s)" : "%3d: DNSServiceReconfirmRecord(%s) interface %d failed PID[%d](%s) status %d", request->sd, RRDisplayString(&mDNSStorage, &rr->resrec), mDNSPlatformInterfaceIndexfromInterfaceID(&mDNSStorage, rr->resrec.InterfaceID, mDNSfalse), request->process_id, request->pid_name, status); freeL("AuthRecord/handle_reconfirm_request", rr); } return(status); } #if APPLE_OSX_mDNSResponder mDNSlocal mStatus handle_release_request(request_state *request) { mStatus err = 0; char name[256], regtype[MAX_ESCAPED_DOMAIN_NAME], domain[MAX_ESCAPED_DOMAIN_NAME]; domainname instance; // extract the data from the message DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); if (get_string(&request->msgptr, request->msgend, name, sizeof(name )) < 0 || get_string(&request->msgptr, request->msgend, regtype, sizeof(regtype)) < 0 || get_string(&request->msgptr, request->msgend, domain, sizeof(domain )) < 0) { LogMsg("ERROR: handle_release_request - Couldn't read name/regtype/domain"); return(mStatus_BadParamErr); } if (!request->msgptr) { LogMsg("%3d: PeerConnectionRelease(unreadable parameters)", request->sd); return(mStatus_BadParamErr); } if (build_domainname_from_strings(&instance, name, regtype, domain) < 0) { LogMsg("ERROR: handle_release_request bad “%s” “%s” “%s”", name, regtype, domain); return(mStatus_BadParamErr); } LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] PeerConnectionRelease(%X " PRI_DM_NAME ") START PID[%d](" PUB_S ")", request->request_id, flags, DM_NAME_PARAM(&instance), request->process_id, request->pid_name); #if MDNSRESPONDER_SUPPORTS(APPLE, D2D) external_connection_release(&instance); #endif return(err); } #else // APPLE_OSX_mDNSResponder mDNSlocal mStatus handle_release_request(request_state *request) { (void) request; return mStatus_UnsupportedErr; } #endif // APPLE_OSX_mDNSResponder mDNSlocal mStatus handle_setdomain_request(request_state *request) { char domainstr[MAX_ESCAPED_DOMAIN_NAME]; domainname domain; DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); (void)flags; // Unused if (get_string(&request->msgptr, request->msgend, domainstr, sizeof(domainstr)) < 0 || !MakeDomainNameFromDNSNameString(&domain, domainstr)) { LogMsg("%3d: DNSServiceSetDefaultDomainForUser(unreadable parameters)", request->sd); return(mStatus_BadParamErr); } LogOperation("%3d: DNSServiceSetDefaultDomainForUser(%##s)", request->sd, domain.c); return(mStatus_NoError); } typedef packedstruct { mStatus err; mDNSu32 len; mDNSu32 vers; } DaemonVersionReply; mDNSlocal void handle_getproperty_request(request_state *request) { const mStatus BadParamErr = dnssd_htonl((mDNSu32)mStatus_BadParamErr); char prop[256]; if (get_string(&request->msgptr, request->msgend, prop, sizeof(prop)) >= 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceGetProperty(" PUB_S ")", request->request_id, prop); if (!strcmp(prop, kDNSServiceProperty_DaemonVersion)) { DaemonVersionReply x = { 0, dnssd_htonl(4), dnssd_htonl(_DNS_SD_H) }; send_all(request->sd, (const char *)&x, sizeof(x)); return; } } // If we didn't recogize the requested property name, return BadParamErr send_all(request->sd, (const char *)&BadParamErr, sizeof(BadParamErr)); } #ifdef APPLE_OSX_mDNSResponder // The caller can specify either the pid or the uuid. If the pid is not specified, // update the effective uuid. Don't overwrite the pid which is used for debugging // purposes and initialized when the socket is opened. mDNSlocal void handle_connection_delegate_request(request_state *request) { mDNSs32 pid; socklen_t len; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceCreateDelegateConnection START PID[%d](" PUB_S ")", request->request_id, request->process_id, request->pid_name); request->terminate = connection_termination; len = 0; pid = get_uint32(&request->msgptr, request->msgend); #ifdef LOCAL_PEEREPID if (pid) { len = sizeof(pid); if (getsockopt(request->sd, SOL_LOCAL, LOCAL_PEEREPID, &request->process_id, &len) != 0) { LogMsg("handle_connection_delegate_request: getsockopt for LOCAL_PEEREPID failed errno:%d / %s", errno, strerror(errno)); return; } // to extract the process name from the pid value if (proc_pidinfo(request->process_id, PROC_PIDT_SHORTBSDINFO, 1, &proc, PROC_PIDT_SHORTBSDINFO_SIZE) == 0) return; mDNSPlatformStrLCopy(request->pid_name, proc.pbsi_comm, sizeof(request->pid_name)); debugf("handle_connection_delegate_request: process id %d, name %s", request->process_id, request->pid_name); } #endif #ifdef LOCAL_PEEREUUID if (!pid) { len = UUID_SIZE; if (getsockopt(request->sd, SOL_LOCAL, LOCAL_PEEREUUID, request->uuid, &len) != 0) { LogMsg("handle_connection_delegate_request: getsockopt for LOCAL_PEEREUUID failed errno:%d / %s", errno, strerror(errno)); return; } request->validUUID = mDNStrue; } #endif } #else mDNSlocal void handle_connection_delegate_request(request_state *request) { (void) request; } #endif typedef packedstruct { mStatus err; mDNSs32 pid; } PIDInfo; // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceNATPortMappingCreate #endif #define DNSServiceProtocol(X) ((X) == NATOp_AddrRequest ? 0 : (X) == NATOp_MapUDP ? kDNSServiceProtocol_UDP : kDNSServiceProtocol_TCP) mDNSlocal void port_mapping_termination_callback(request_state *request) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceNATPortMappingCreate(%X, %u, %u, %d) STOP PID[%d](" PUB_S ")", request->request_id, DNSServiceProtocol(request->u.pm.NATinfo.Protocol), mDNSVal16(request->u.pm.NATinfo.IntPort), mDNSVal16(request->u.pm.ReqExt), request->u.pm.NATinfo.NATLease, request->process_id, request->pid_name); mDNS_StopNATOperation(&mDNSStorage, &request->u.pm.NATinfo); } // Called via function pointer when we get a NAT Traversal (address request or port mapping) response mDNSlocal void port_mapping_create_request_callback(mDNS *m, NATTraversalInfo *n) { request_state *request = (request_state *)n->clientContext; reply_state *rep; int replyLen; char *data; if (!request) { LogMsg("port_mapping_create_request_callback called with unknown request_state object"); return; } // calculate reply data length replyLen = sizeof(DNSServiceFlags); replyLen += 3 * sizeof(mDNSu32); // if index + addr + ttl replyLen += sizeof(DNSServiceErrorType); replyLen += 2 * sizeof(mDNSu16); // Internal Port + External Port replyLen += sizeof(mDNSu8); // protocol rep = create_reply(port_mapping_reply_op, replyLen, request); rep->rhdr->flags = dnssd_htonl(0); rep->rhdr->ifi = dnssd_htonl(mDNSPlatformInterfaceIndexfromInterfaceID(m, n->InterfaceID, mDNSfalse)); rep->rhdr->error = dnssd_htonl(n->Result); data = (char *)&rep->rhdr[1]; *data++ = request->u.pm.NATinfo.ExternalAddress.b[0]; *data++ = request->u.pm.NATinfo.ExternalAddress.b[1]; *data++ = request->u.pm.NATinfo.ExternalAddress.b[2]; *data++ = request->u.pm.NATinfo.ExternalAddress.b[3]; *data++ = DNSServiceProtocol(request->u.pm.NATinfo.Protocol); *data++ = request->u.pm.NATinfo.IntPort.b[0]; *data++ = request->u.pm.NATinfo.IntPort.b[1]; *data++ = request->u.pm.NATinfo.ExternalPort.b[0]; *data++ = request->u.pm.NATinfo.ExternalPort.b[1]; put_uint32(request->u.pm.NATinfo.Lifetime, &data); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceNATPortMappingCreate(%X, %u, %u, %d) RESULT " PRI_IPv4_ADDR ":%u TTL %u", request->request_id, DNSServiceProtocol(request->u.pm.NATinfo.Protocol), mDNSVal16(request->u.pm.NATinfo.IntPort), mDNSVal16(request->u.pm.ReqExt), request->u.pm.NATinfo.NATLease, &request->u.pm.NATinfo.ExternalAddress, mDNSVal16(request->u.pm.NATinfo.ExternalPort), request->u.pm.NATinfo.Lifetime); append_reply(request, rep); } mDNSlocal mStatus handle_port_mapping_request(request_state *request) { mDNSu32 ttl = 0; mStatus err = mStatus_NoError; DNSServiceFlags flags = get_flags(&request->msgptr, request->msgend); mDNSu32 interfaceIndex = get_uint32(&request->msgptr, request->msgend); mDNSInterfaceID InterfaceID = mDNSPlatformInterfaceIDfromInterfaceIndex(&mDNSStorage, interfaceIndex); mDNSu8 protocol = (mDNSu8)get_uint32(&request->msgptr, request->msgend); (void)flags; // Unused if (interfaceIndex && !InterfaceID) return(mStatus_BadParamErr); if (request->msgptr + 8 > request->msgend) request->msgptr = NULL; else { request->u.pm.NATinfo.IntPort.b[0] = *request->msgptr++; request->u.pm.NATinfo.IntPort.b[1] = *request->msgptr++; request->u.pm.ReqExt.b[0] = *request->msgptr++; request->u.pm.ReqExt.b[1] = *request->msgptr++; ttl = get_uint32(&request->msgptr, request->msgend); } if (!request->msgptr) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%d] DNSServiceNATPortMappingCreate(unreadable parameters)", request->request_id); return(mStatus_BadParamErr); } if (protocol == 0) // If protocol == 0 (i.e. just request public address) then IntPort, ExtPort, ttl must be zero too { if (!mDNSIPPortIsZero(request->u.pm.NATinfo.IntPort) || !mDNSIPPortIsZero(request->u.pm.ReqExt) || ttl) return(mStatus_BadParamErr); } else { if (mDNSIPPortIsZero(request->u.pm.NATinfo.IntPort)) return(mStatus_BadParamErr); if (!(protocol & (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP))) return(mStatus_BadParamErr); } request->flags = flags; request->interfaceIndex = interfaceIndex; request->u.pm.NATinfo.Protocol = !protocol ? NATOp_AddrRequest : (protocol == kDNSServiceProtocol_UDP) ? NATOp_MapUDP : NATOp_MapTCP; // u.pm.NATinfo.IntPort = already set above request->u.pm.NATinfo.RequestedPort = request->u.pm.ReqExt; request->u.pm.NATinfo.NATLease = ttl; request->u.pm.NATinfo.clientCallback = port_mapping_create_request_callback; request->u.pm.NATinfo.clientContext = request; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceNATPortMappingCreate(%X, %u, %u, %d) START PID[%d](" PUB_S ")", request->request_id, protocol, mDNSVal16(request->u.pm.NATinfo.IntPort), mDNSVal16(request->u.pm.ReqExt), request->u.pm.NATinfo.NATLease, request->process_id, request->pid_name); err = mDNS_StartNATOperation(&mDNSStorage, &request->u.pm.NATinfo); if (err) LogMsg("ERROR: mDNS_StartNATOperation: %d", (int)err); else request->terminate = port_mapping_termination_callback; return(err); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - DNSServiceGetAddrInfo #endif mDNSlocal void addrinfo_termination_callback(request_state *request) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSServiceGetAddrInfo(" PRI_DM_NAME ") STOP PID[%d](" PUB_S ")", request->request_id, DM_NAME_PARAM(GetAddrInfoClientRequestGetQName(&request->u.addrinfo)), request->process_id, request->pid_name); GetAddrInfoClientRequestStop(&request->u.addrinfo); } typedef struct { mDNSu32 protocols; char hostname[MAX_ESCAPED_DOMAIN_NAME]; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mDNSBool require_privacy; #endif } _addrinfo_start_params_t; mDNSlocal mStatus _handle_addrinfo_request_start(request_state *request, const _addrinfo_start_params_t * const params) { mStatus err; request->terminate = addrinfo_termination_callback; GetAddrInfoClientRequestParams gaiParams; GetAddrInfoClientRequestParamsInit(&gaiParams); gaiParams.requestID = request->request_id; gaiParams.hostnameStr = params->hostname; gaiParams.interfaceIndex = request->interfaceIndex; gaiParams.flags = request->flags; gaiParams.protocols = params->protocols; gaiParams.effectivePID = request->validUUID ? 0 : request->process_id; gaiParams.effectiveUUID = request->validUUID ? request->uuid : mDNSNULL; gaiParams.peerUID = request->uid; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) gaiParams.needEncryption = params->require_privacy ? mDNStrue : mDNSfalse; gaiParams.customID = request->custom_service_id; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) gaiParams.peerAuditToken = &request->audit_token; #endif err = GetAddrInfoClientRequestStart(&request->u.addrinfo, &gaiParams, queryrecord_result_reply, request); return err; } #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mDNSlocal void _return_addrinfo_request_error(request_state * request, mStatus error) { _return_queryrecord_request_error(request, error); } mDNSlocal mStatus _handle_addrinfo_request_with_trust(request_state *request, const _addrinfo_start_params_t * const params) { mStatus err; if (audit_token_to_pid(request->audit_token) == 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_WARNING, "[R%u] _handle_addrinfo_request_with_trust: no audit token for pid(%s %d)", request->request_id, request->pid_name, request->process_id); err = _handle_addrinfo_request_start(request, params); } else { mdns_trust_flags_t flags = mdns_trust_flags_none; mdns_trust_status_t status = mdns_trust_check_getaddrinfo(request->audit_token, params->hostname, &flags); switch (status) { case mdns_trust_status_denied: case mdns_trust_status_pending: { mdns_trust_t trust = mdns_trust_create(request->audit_token, NULL, flags); if (!trust ) { err = mStatus_NoMemoryErr; goto exit; } void * context = mallocL("context/_handle_addrinfo_request_with_trust", sizeof(_addrinfo_start_params_t)); if (!context) { my_perror("ERROR: mallocL context/_handle_addrinfo_request_with_trust"); mdns_release(trust); err = mStatus_NoMemoryErr; goto exit; } memcpy(context, params, sizeof(_addrinfo_start_params_t)); mdns_trust_set_context(trust, context); mdns_trust_set_queue(trust, _get_trust_results_dispatch_queue()); mdns_trust_set_event_handler(trust, ^(mdns_trust_event_t event, mdns_trust_status_t update) { if (event == mdns_trust_event_result) { mStatus error = (update != mdns_trust_status_granted) ? mStatus_PolicyDenied : mStatus_NoError; KQueueLock(); _addrinfo_start_params_t * _params = mdns_trust_get_context(trust); if (_params) { if (!error) { error = _handle_addrinfo_request_start(request, _params); // No context means the request was canceled before we got here } if (error) // (not else if) Always check for error result { _return_addrinfo_request_error(request, error); } } KQueueUnlock("_handle_addrinfo_request_with_trust"); } }); request->trust = trust; mdns_trust_activate(trust); err = mStatus_NoError; break; } case mdns_trust_status_no_entitlement: err = mStatus_NoAuth; break; case mdns_trust_status_granted: err = _handle_addrinfo_request_start(request, params); break; default: err = mStatus_UnknownErr; break; } } exit: return err; } #endif // TRUST_ENFORCEMENT mDNSlocal mStatus handle_addrinfo_request(request_state *request) { mStatus err; DNSServiceFlags flags; mDNSu32 interfaceIndex; _addrinfo_start_params_t params; flags = get_flags(&request->msgptr, request->msgend); interfaceIndex = get_uint32(&request->msgptr, request->msgend); params.protocols = get_uint32(&request->msgptr, request->msgend); if (get_string(&request->msgptr, request->msgend, params.hostname, sizeof(params.hostname)) < 0) { err = mStatus_BadParamErr; goto exit; } if (!request->msgptr) { LogMsg("%3d: DNSServiceGetAddrInfo(unreadable parameters)", request->sd); err = mStatus_BadParamErr; goto exit; } #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) params.require_privacy = mDNSfalse; #endif #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) && MDNSRESPONDER_SUPPORTS(APPLE, IPC_TLV) if (request->msgptr && (request->hdr.ipc_flags & IPC_FLAGS_TRAILING_TLVS)) { size_t len; const mDNSu8 *const start = (const mDNSu8 *)request->msgptr; const mDNSu8 *const end = (const mDNSu8 *)request->msgend; const mDNSu8 *const data = ipc_tlv_get_resolver_config_plist_data(start, end, &len); if (data) { request->custom_service_id = Querier_RegisterCustomDNSServiceWithPListData(data, len); } params.require_privacy = ipc_tlv_get_require_privacy(start, end); } #endif request->flags = flags; request->interfaceIndex = interfaceIndex; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] DNSServiceGetAddrInfo(%X, %d, %u, " PRI_S ") START PID[%d](" PUB_S ")", request->request_id, request->flags, request->interfaceIndex, params.protocols, params.hostname, request->process_id, request->pid_name); mDNSPlatformMemZero(&request->u.addrinfo, (mDNSu32)sizeof(request->u.addrinfo)); request->terminate = NULL; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) if (os_feature_enabled(mDNSResponder, bonjour_privacy)) { err = _handle_addrinfo_request_with_trust(request, ¶ms); } else { err = _handle_addrinfo_request_start(request, ¶ms); } #else err = _handle_addrinfo_request_start(request, ¶ms); #endif exit: return(err); } // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Main Request Handler etc. #endif mDNSlocal request_state *NewRequest(void) { request_state *request; request_state **p = &all_requests; request = (request_state *) callocL("request_state", sizeof(*request)); if (!request) FatalError("ERROR: calloc"); while (*p) p = &(*p)->next; *p = request; return(request); } // read_msg may be called any time when the transfer state (req->ts) is t_morecoming. // if there is no data on the socket, the socket will be closed and t_terminated will be returned mDNSlocal void read_msg(request_state *req) { if (req->ts == t_terminated || req->ts == t_error) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read_msg called with transfer state terminated or error", req->request_id); req->ts = t_error; return; } if (req->ts == t_complete) // this must be death or something is wrong { char buf[4]; // dummy for death notification int nread = udsSupportReadFD(req->sd, buf, 4, 0, req->platform_data); if (!nread) { req->ts = t_terminated; return; } if (nread < 0) goto rerror; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read data from a completed request", req->request_id); req->ts = t_error; return; } if (req->ts != t_morecoming) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read_msg called with invalid transfer state (%d)", req->request_id, req->ts); req->ts = t_error; return; } if (req->hdr_bytes < sizeof(ipc_msg_hdr)) { mDNSu32 nleft = sizeof(ipc_msg_hdr) - req->hdr_bytes; int nread = udsSupportReadFD(req->sd, (char *)&req->hdr + req->hdr_bytes, nleft, 0, req->platform_data); if (nread == 0) { req->ts = t_terminated; return; } if (nread < 0) goto rerror; req->hdr_bytes += nread; if (req->hdr_bytes > sizeof(ipc_msg_hdr)) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read_msg - read too many header bytes", req->request_id); req->ts = t_error; return; } // only read data if header is complete if (req->hdr_bytes == sizeof(ipc_msg_hdr)) { ConvertHeaderBytes(&req->hdr); if (req->hdr.version != VERSION) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: client version 0x%08X daemon version 0x%08X", req->request_id, req->hdr.version, VERSION); req->ts = t_error; return; } // Largest conceivable single request is a DNSServiceRegisterRecord() or DNSServiceAddRecord() // with 64kB of rdata. Adding 1009 byte for a maximal domain name, plus a safety margin // for other overhead, this means any message above 70kB is definitely bogus. if (req->hdr.datalen > 70000) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read_msg: hdr.datalen %u (0x%X) > 70000", req->request_id, req->hdr.datalen, req->hdr.datalen); req->ts = t_error; return; } req->msgbuf = (char *) callocL("request_state msgbuf", req->hdr.datalen + MSG_PAD_BYTES); if (!req->msgbuf) { my_perror("ERROR: calloc"); req->ts = t_error; return; } req->msgptr = req->msgbuf; req->msgend = req->msgbuf + req->hdr.datalen; } } // If our header is complete, but we're still needing more body data, then try to read it now // Note: For cancel_request req->hdr.datalen == 0, but there's no error return socket for cancel_request // Any time we need to get the error return socket we know we'll have at least one data byte // (even if only the one-byte empty C string placeholder for the old ctrl_path parameter) if (req->hdr_bytes == sizeof(ipc_msg_hdr) && req->data_bytes < req->hdr.datalen) { mDNSu32 nleft = req->hdr.datalen - req->data_bytes; ssize_t nread; #if !defined(_WIN32) struct iovec vec = { req->msgbuf + req->data_bytes, nleft }; // Tell recvmsg where we want the bytes put struct msghdr msg; struct cmsghdr *cmsg; char cbuf[CMSG_SPACE(4 * sizeof(dnssd_sock_t))]; msg.msg_name = 0; msg.msg_namelen = 0; msg.msg_iov = &vec; msg.msg_iovlen = 1; msg.msg_control = cbuf; msg.msg_controllen = sizeof(cbuf); msg.msg_flags = 0; nread = recvmsg(req->sd, &msg, 0); #else nread = udsSupportReadFD(req->sd, (char *)req->msgbuf + req->data_bytes, nleft, 0, req->platform_data); #endif if (nread == 0) { req->ts = t_terminated; return; } if (nread < 0) goto rerror; req->data_bytes += nread; if (req->data_bytes > req->hdr.datalen) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read_msg - read too many data bytes", req->request_id); req->ts = t_error; return; } #if !defined(_WIN32) cmsg = CMSG_FIRSTHDR(&msg); #if DEBUG_64BIT_SCM_RIGHTS LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] Expecting %d %d %d %d", req->request_id, sizeof(cbuf), sizeof(cbuf), SOL_SOCKET, SCM_RIGHTS); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] Got %d %d %d %d", req->request_id, msg.msg_controllen, cmsg ? cmsg->cmsg_len : -1, cmsg ? cmsg->cmsg_level : -1, cmsg ? cmsg->cmsg_type : -1); #endif // DEBUG_64BIT_SCM_RIGHTS if (cmsg && cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { #if APPLE_OSX_mDNSResponder // Strictly speaking BPF_fd belongs solely in the platform support layer, but because // of privilege separation on Mac OS X we need to get BPF_fd from mDNSResponderHelper, // and it's convenient to repurpose the existing fd-passing code here for that task if (req->hdr.op == send_bpf) { dnssd_sock_t x = *(dnssd_sock_t *)CMSG_DATA(cmsg); LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] Got len %d, BPF %d", req->request_id, cmsg->cmsg_len, x); mDNSPlatformReceiveBPF_fd(x); } else #endif // APPLE_OSX_mDNSResponder req->errsd = *(dnssd_sock_t *)CMSG_DATA(cmsg); #if DEBUG_64BIT_SCM_RIGHTS LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, "[R%u] read req->errsd %d", req->request_id, req->errsd); #endif // DEBUG_64BIT_SCM_RIGHTS if (req->data_bytes < req->hdr.datalen) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEBUG, "[R%u] Client(PID [%d](" PUB_S ")) sent result code socket %d via SCM_RIGHTS with req->data_bytes %d < req->hdr.datalen %d", req->request_id, req->process_id, req->pid_name, req->errsd, req->data_bytes, req->hdr.datalen); req->ts = t_error; return; } } #endif } // If our header and data are both complete, see if we need to make our separate error return socket if (req->hdr_bytes == sizeof(ipc_msg_hdr) && req->data_bytes == req->hdr.datalen) { if (req->terminate && req->hdr.op != cancel_request) { dnssd_sockaddr_t cliaddr; #if defined(USE_TCP_LOOPBACK) mDNSOpaque16 port; u_long opt = 1; port.b[0] = req->msgptr[0]; port.b[1] = req->msgptr[1]; req->msgptr += 2; cliaddr.sin_family = AF_INET; cliaddr.sin_port = port.NotAnInteger; cliaddr.sin_addr.s_addr = inet_addr(MDNS_TCP_SERVERADDR); #else char ctrl_path[MAX_CTLPATH]; get_string(&req->msgptr, req->msgend, ctrl_path, MAX_CTLPATH); // path is first element in message buffer mDNSPlatformMemZero(&cliaddr, sizeof(cliaddr)); cliaddr.sun_family = AF_LOCAL; mDNSPlatformStrLCopy(cliaddr.sun_path, ctrl_path, sizeof(cliaddr.sun_path)); // If the error return path UDS name is empty string, that tells us // that this is a new version of the library that's going to pass us // the error return path socket via sendmsg/recvmsg if (ctrl_path[0] == 0) { if (req->errsd == req->sd) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] read_msg: ERROR failed to get errsd via SCM_RIGHTS", req->request_id); req->ts = t_error; return; } goto got_errfd; } #endif req->errsd = socket(AF_DNSSD, SOCK_STREAM, 0); if (!dnssd_SocketValid(req->errsd)) { my_throttled_perror("ERROR: socket"); req->ts = t_error; return; } if (connect(req->errsd, (struct sockaddr *)&cliaddr, sizeof(cliaddr)) < 0) { #if !defined(USE_TCP_LOOPBACK) struct stat sb; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] read_msg: Couldn't connect to error return path socket " PUB_S " errno %d (" PUB_S ")", req->request_id, cliaddr.sun_path, dnssd_errno, dnssd_strerror(dnssd_errno)); if (stat(cliaddr.sun_path, &sb) < 0) { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] read_msg: stat failed " PUB_S " errno %d (" PUB_S ")", req->request_id, cliaddr.sun_path, dnssd_errno, dnssd_strerror(dnssd_errno)); } else { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] read_msg: file " PUB_S " mode %o (octal) uid %d gid %d", req->request_id, cliaddr.sun_path, sb.st_mode, sb.st_uid, sb.st_gid); } #endif req->ts = t_error; return; } #if !defined(USE_TCP_LOOPBACK) got_errfd: #endif #if defined(_WIN32) if (ioctlsocket(req->errsd, FIONBIO, &opt) != 0) #else if (fcntl(req->errsd, F_SETFL, fcntl(req->errsd, F_GETFL, 0) | O_NONBLOCK) != 0) #endif { LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: could not set control socket to non-blocking mode errno %d (" PUB_S ")", req->request_id, dnssd_errno, dnssd_strerror(dnssd_errno)); req->ts = t_error; return; } } req->ts = t_complete; } return; rerror: if (dnssd_errno == dnssd_EWOULDBLOCK || dnssd_errno == dnssd_EINTR) return; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "[R%u] ERROR: read_msg errno %d (" PUB_S ")", req->request_id, dnssd_errno, dnssd_strerror(dnssd_errno)); req->ts = t_error; } mDNSlocal mStatus handle_client_request(request_state *req) { mStatus err = mStatus_NoError; #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) SetupAuditTokenForRequest(req); #endif switch(req->hdr.op) { // These are all operations that have their own first-class request_state object case connection_request: LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceCreateConnection START PID[%d](" PUB_S ")", req->request_id, req->process_id, req->pid_name); req->terminate = connection_termination; break; case connection_delegate_request: LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%d] DNSServiceCreateDelegateConnection START PID[%d](" PRI_S ")", req->request_id, req->process_id, req->pid_name); req->terminate = connection_termination; handle_connection_delegate_request(req); break; case resolve_request: err = handle_resolve_request (req); break; case query_request: err = handle_queryrecord_request (req); break; case browse_request: err = handle_browse_request (req); break; case reg_service_request: err = handle_regservice_request (req); break; case enumeration_request: err = handle_enum_request (req); break; case reconfirm_record_request: err = handle_reconfirm_request (req); break; case setdomain_request: err = handle_setdomain_request (req); break; case getproperty_request: handle_getproperty_request (req); break; case port_mapping_request: err = handle_port_mapping_request(req); break; case addrinfo_request: err = handle_addrinfo_request (req); break; case send_bpf: /* Do nothing for send_bpf */ break; // These are all operations that work with an existing request_state object case reg_record_request: err = handle_regrecord_request (req); break; case add_record_request: err = handle_add_request (req); break; case update_record_request: err = handle_update_request (req); break; case remove_record_request: err = handle_removerecord_request(req); break; case cancel_request: handle_cancel_request (req); break; case release_request: err = handle_release_request (req); break; default: LogMsg("request_callback: %3d:ERROR: Unsupported UDS req:%d PID[%d][%s]", req->sd, req->hdr.op, req->process_id, req->pid_name); err = mStatus_BadParamErr; break; } return err; } #define RecordOrientedOp(X) \ ((X) == reg_record_request || (X) == add_record_request || (X) == update_record_request || (X) == remove_record_request) // The lightweight operations are the ones that don't need a dedicated request_state structure allocated for them #define LightweightOp(X) (RecordOrientedOp(X) || (X) == cancel_request) mDNSlocal void request_callback(int fd, void *info) { mStatus err = 0; request_state *req = info; mDNSs32 min_size = sizeof(DNSServiceFlags); (void)fd; // Unused for (;;) { read_msg(req); if (req->ts == t_morecoming) return; if (req->ts == t_terminated || req->ts == t_error) { AbortUnlinkAndFree(req); return; } if (req->ts != t_complete) { LogMsg("request_callback: req->ts %d != t_complete PID[%d][%s]", req->ts, req->process_id, req->pid_name); AbortUnlinkAndFree(req); return; } switch(req->hdr.op) // Interface + other data { case connection_request: min_size = 0; break; case connection_delegate_request: min_size = 4; /* pid */ break; case reg_service_request: min_size += sizeof(mDNSu32) + 4 /* name, type, domain, host */ + 4 /* port, textlen */; break; case add_record_request: min_size += 4 /* type, rdlen */ + 4 /* ttl */; break; case update_record_request: min_size += 2 /* rdlen */ + 4 /* ttl */; break; case remove_record_request: break; case browse_request: min_size += sizeof(mDNSu32) + 2 /* type, domain */; break; case resolve_request: min_size += sizeof(mDNSu32) + 3 /* type, type, domain */; break; case query_request: min_size += sizeof(mDNSu32) + 1 /* name */ + 4 /* type, class*/; break; case enumeration_request: min_size += sizeof(mDNSu32); break; case reg_record_request: min_size += sizeof(mDNSu32) + 1 /* name */ + 6 /* type, class, rdlen */ + 4 /* ttl */; break; case reconfirm_record_request: min_size += sizeof(mDNSu32) + 1 /* name */ + 6 /* type, class, rdlen */; break; case setdomain_request: min_size += 1 /* domain */; break; case getproperty_request: min_size = 2; break; case port_mapping_request: min_size += sizeof(mDNSu32) + 4 /* udp/tcp */ + 4 /* int/ext port */ + 4 /* ttl */; break; case addrinfo_request: min_size += sizeof(mDNSu32) + 4 /* v4/v6 */ + 1 /* hostname */; break; case send_bpf: // Same as cancel_request below case cancel_request: min_size = 0; break; case release_request: min_size += sizeof(mDNSu32) + 3 /* type, type, domain */; break; default: LogMsg("request_callback: ERROR: validate_message - unsupported req type: %d PID[%d][%s]", req->hdr.op, req->process_id, req->pid_name); min_size = -1; break; } if ((mDNSs32)req->data_bytes < min_size) { LogMsg("request_callback: Invalid message %d bytes; min for %d is %d PID[%d][%s]", req->data_bytes, req->hdr.op, min_size, req->process_id, req->pid_name); AbortUnlinkAndFree(req); return; } if (LightweightOp(req->hdr.op) && !req->terminate) { LogMsg("request_callback: Reg/Add/Update/Remove %d require existing connection PID[%d][%s]", req->hdr.op, req->process_id, req->pid_name); AbortUnlinkAndFree(req); return; } // If req->terminate is already set, this means this operation is sharing an existing connection if (req->terminate && !LightweightOp(req->hdr.op)) { request_state *newreq = NewRequest(); newreq->primary = req; newreq->sd = req->sd; newreq->errsd = req->errsd; newreq->uid = req->uid; newreq->hdr = req->hdr; newreq->msgbuf = req->msgbuf; newreq->msgptr = req->msgptr; newreq->msgend = req->msgend; newreq->request_id = GetNewRequestID(); #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) newreq->audit_token = req->audit_token; #endif // if the parent request is a delegate connection, copy the // relevant bits if (req->validUUID) { newreq->validUUID = mDNStrue; mDNSPlatformMemCopy(newreq->uuid, req->uuid, UUID_SIZE); } else { if (req->process_id) { newreq->process_id = req->process_id; mDNSPlatformStrLCopy(newreq->pid_name, req->pid_name, (mDNSu32)sizeof(newreq->pid_name)); } else { set_peer_pid(newreq); } } req = newreq; } // Check if the request wants no asynchronous replies. if (req->hdr.ipc_flags & IPC_FLAGS_NOREPLY) req->no_reply = 1; // If we're shutting down, don't allow new client requests // We do allow "cancel" and "getproperty" during shutdown if (mDNSStorage.ShutdownTime && req->hdr.op != cancel_request && req->hdr.op != getproperty_request) err = mStatus_ServiceNotRunning; else err = handle_client_request(req); // req->msgbuf may be NULL, e.g. for connection_request or remove_record_request if (req->msgbuf) freeL("request_state msgbuf", req->msgbuf); // There's no return data for a cancel request (DNSServiceRefDeallocate returns no result) // For a DNSServiceGetProperty call, the handler already generated the response, so no need to do it again here if (req->hdr.op != cancel_request && req->hdr.op != getproperty_request && req->hdr.op != send_bpf && req->hdr.op != getpid_request) { const mStatus err_netorder = dnssd_htonl(err); send_all(req->errsd, (const char *)&err_netorder, sizeof(err_netorder)); if (req->errsd != req->sd) { dnssd_close(req->errsd); req->errsd = req->sd; // Also need to reset the parent's errsd, if this is a subordinate operation if (req->primary) req->primary->errsd = req->primary->sd; } } // Reset ready to accept the next req on this pipe if (req->primary) req = req->primary; req->ts = t_morecoming; req->hdr_bytes = 0; req->data_bytes = 0; req->msgbuf = mDNSNULL; req->msgptr = mDNSNULL; req->msgend = 0; } } mDNSlocal void connect_callback(int fd, void *info) { dnssd_sockaddr_t cliaddr; dnssd_socklen_t len = (dnssd_socklen_t) sizeof(cliaddr); dnssd_sock_t sd = accept(fd, (struct sockaddr*) &cliaddr, &len); #if defined(SO_NOSIGPIPE) || defined(_WIN32) unsigned long optval = 1; #endif (void)info; // Unused if (!dnssd_SocketValid(sd)) { if (dnssd_errno != dnssd_EWOULDBLOCK) my_throttled_perror("ERROR: accept"); return; } #ifdef SO_NOSIGPIPE // Some environments (e.g. OS X) support turning off SIGPIPE for a socket if (setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &optval, sizeof(optval)) < 0) LogMsg("%3d: WARNING: setsockopt - SO_NOSIGPIPE %d (%s)", sd, dnssd_errno, dnssd_strerror(dnssd_errno)); #endif #if defined(_WIN32) if (ioctlsocket(sd, FIONBIO, &optval) != 0) #else if (fcntl(sd, F_SETFL, fcntl(sd, F_GETFL, 0) | O_NONBLOCK) != 0) #endif { my_perror("ERROR: fcntl(sd, F_SETFL, O_NONBLOCK) - aborting client"); dnssd_close(sd); return; } else { request_state *request = NewRequest(); request->ts = t_morecoming; request->sd = sd; request->errsd = sd; request->request_id = GetNewRequestID(); set_peer_pid(request); #if APPLE_OSX_mDNSResponder struct xucred x; socklen_t xucredlen = sizeof(x); if (getsockopt(sd, 0, LOCAL_PEERCRED, &x, &xucredlen) >= 0 && x.cr_version == XUCRED_VERSION) request->uid = x.cr_uid; // save the effective userid of the client else my_perror("ERROR: getsockopt, LOCAL_PEERCRED"); debugf("LOCAL_PEERCRED %d %u %u %d", xucredlen, x.cr_version, x.cr_uid, x.cr_ngroups); #endif // APPLE_OSX_mDNSResponder LogDebug("%3d: connect_callback: Adding FD for uid %u", request->sd, request->uid); udsSupportAddFDToEventLoop(sd, request_callback, request, &request->platform_data); } } mDNSlocal mDNSBool uds_socket_setup(dnssd_sock_t skt) { #if defined(SO_NP_EXTENSIONS) struct so_np_extensions sonpx; socklen_t optlen = sizeof(struct so_np_extensions); sonpx.npx_flags = SONPX_SETOPTSHUT; sonpx.npx_mask = SONPX_SETOPTSHUT; if (setsockopt(skt, SOL_SOCKET, SO_NP_EXTENSIONS, &sonpx, optlen) < 0) my_perror("WARNING: could not set sockopt - SO_NP_EXTENSIONS"); #endif #if defined(_WIN32) // SEH: do we even need to do this on windows? // This socket will be given to WSAEventSelect which will automatically set it to non-blocking u_long opt = 1; if (ioctlsocket(skt, FIONBIO, &opt) != 0) #else if (fcntl(skt, F_SETFL, fcntl(skt, F_GETFL, 0) | O_NONBLOCK) != 0) #endif { my_perror("ERROR: could not set listen socket to non-blocking mode"); return mDNSfalse; } if (listen(skt, LISTENQ) != 0) { my_perror("ERROR: could not listen on listen socket"); return mDNSfalse; } if (mStatus_NoError != udsSupportAddFDToEventLoop(skt, connect_callback, (void *) NULL, (void **) NULL)) { my_perror("ERROR: could not add listen socket to event loop"); return mDNSfalse; } else { LogOperation("%3d: Listening for incoming Unix Domain Socket client requests", skt); mDNSStorage.uds_listener_skt = skt; } return mDNStrue; } #if MDNS_MALLOC_DEBUGGING mDNSlocal void udsserver_validatelists(void *context); #endif mDNSexport int udsserver_init(dnssd_sock_t skts[], const size_t count) { dnssd_sockaddr_t laddr; int ret; #ifndef NO_PID_FILE FILE *fp = fopen(PID_FILE, "w"); if (fp != NULL) { fprintf(fp, "%d\n", getpid()); fclose(fp); } #endif #if MDNS_MALLOC_DEBUGGING static mDNSListValidator validator; mDNSPlatformAddListValidator(&validator, udsserver_validatelists, "udsserver_validatelists", NULL); #endif if (skts) { size_t i; for (i = 0; i < count; i++) if (dnssd_SocketValid(skts[i]) && !uds_socket_setup(skts[i])) goto error; } else { listenfd = socket(AF_DNSSD, SOCK_STREAM, 0); if (!dnssd_SocketValid(listenfd)) { my_perror("ERROR: socket(AF_DNSSD, SOCK_STREAM, 0); failed"); goto error; } mDNSPlatformMemZero(&laddr, sizeof(laddr)); #if defined(USE_TCP_LOOPBACK) { laddr.sin_family = AF_INET; laddr.sin_port = htons(MDNS_TCP_SERVERPORT); laddr.sin_addr.s_addr = inet_addr(MDNS_TCP_SERVERADDR); ret = bind(listenfd, (struct sockaddr *) &laddr, sizeof(laddr)); if (ret < 0) { my_perror("ERROR: bind(listenfd, (struct sockaddr *) &laddr, sizeof(laddr)); failed"); goto error; } } #else { mode_t mask = umask(0); unlink(boundPath); // OK if this fails laddr.sun_family = AF_LOCAL; #ifndef NOT_HAVE_SA_LEN // According to Stevens (section 3.2), there is no portable way to // determine whether sa_len is defined on a particular platform. laddr.sun_len = sizeof(struct sockaddr_un); #endif if (strlen(boundPath) >= sizeof(laddr.sun_path)) { LogMsg("ERROR: MDNS_UDS_SERVERPATH must be < %d characters", (int)sizeof(laddr.sun_path)); goto error; } mDNSPlatformStrLCopy(laddr.sun_path, boundPath, sizeof(laddr.sun_path)); ret = bind(listenfd, (struct sockaddr *) &laddr, sizeof(laddr)); umask(mask); if (ret < 0) { my_perror("ERROR: bind(listenfd, (struct sockaddr *) &laddr, sizeof(laddr)); failed"); goto error; } } #endif if (!uds_socket_setup(listenfd)) goto error; } #if !defined(PLATFORM_NO_RLIMIT) { // Set maximum number of open file descriptors #define MIN_OPENFILES 10240 struct rlimit maxfds, newfds; // Due to bugs in OS X (, , ) // you have to get and set rlimits once before getrlimit will return sensible values if (getrlimit(RLIMIT_NOFILE, &maxfds) < 0) { my_perror("ERROR: Unable to get file descriptor limit"); return 0; } if (setrlimit(RLIMIT_NOFILE, &maxfds) < 0) my_perror("ERROR: Unable to set maximum file descriptor limit"); if (getrlimit(RLIMIT_NOFILE, &maxfds) < 0) { my_perror("ERROR: Unable to get file descriptor limit"); return 0; } newfds.rlim_max = (maxfds.rlim_max > MIN_OPENFILES) ? maxfds.rlim_max : MIN_OPENFILES; newfds.rlim_cur = (maxfds.rlim_cur > MIN_OPENFILES) ? maxfds.rlim_cur : MIN_OPENFILES; if (newfds.rlim_max != maxfds.rlim_max || newfds.rlim_cur != maxfds.rlim_cur) if (setrlimit(RLIMIT_NOFILE, &newfds) < 0) my_perror("ERROR: Unable to set maximum file descriptor limit"); if (getrlimit(RLIMIT_NOFILE, &maxfds) < 0) { my_perror("ERROR: Unable to get file descriptor limit"); return 0; } debugf("maxfds.rlim_max %d", (long)maxfds.rlim_max); debugf("maxfds.rlim_cur %d", (long)maxfds.rlim_cur); } #endif // We start a "LocalOnly" query looking for Automatic Browse Domain records. // When Domain Enumeration in uDNS.c finds an "lb" record from the network, its "FoundDomain" routine // creates a "LocalOnly" record, which results in our AutomaticBrowseDomainChange callback being invoked mDNS_GetDomains(&mDNSStorage, &mDNSStorage.AutomaticBrowseDomainQ, mDNS_DomainTypeBrowseAutomatic, mDNSNULL, mDNSInterface_LocalOnly, AutomaticBrowseDomainChange, mDNSNULL); // Add "local" as recommended registration domain ("dns-sd -E"), recommended browsing domain ("dns-sd -F"), and automatic browsing domain RegisterLocalOnlyDomainEnumPTR(&mDNSStorage, &localdomain, mDNS_DomainTypeRegistration); RegisterLocalOnlyDomainEnumPTR(&mDNSStorage, &localdomain, mDNS_DomainTypeBrowse); AddAutoBrowseDomain(0, &localdomain); udsserver_handle_configchange(&mDNSStorage); return 0; error: my_perror("ERROR: udsserver_init"); return -1; } mDNSexport int udsserver_exit(void) { // Cancel all outstanding client requests while (all_requests) AbortUnlinkAndFree(all_requests); // Clean up any special mDNSInterface_LocalOnly records we created, both the entries for "local" we // created in udsserver_init, and others we created as a result of reading local configuration data while (LocalDomainEnumRecords) { ARListElem *rem = LocalDomainEnumRecords; LocalDomainEnumRecords = LocalDomainEnumRecords->next; mDNS_Deregister(&mDNSStorage, &rem->ar); } // If the launching environment created no listening socket, // that means we created it ourselves, so we should clean it up on exit if (dnssd_SocketValid(listenfd)) { dnssd_close(listenfd); #if !defined(USE_TCP_LOOPBACK) // Currently, we're unable to remove /var/run/mdnsd because we've changed to userid "nobody" // to give up unnecessary privilege, but we need to be root to remove this Unix Domain Socket. // It would be nice if we could find a solution to this problem if (unlink(boundPath)) debugf("Unable to remove %s", MDNS_UDS_SERVERPATH); #endif } #ifndef NO_PID_FILE unlink(PID_FILE); #endif return 0; } mDNSlocal void LogClientInfoToFD(int fd, request_state *req) { char reqIDStr[14]; char prefix[18]; mDNS_snprintf(reqIDStr, sizeof(reqIDStr), "[R%u]", req->request_id); mDNS_snprintf(prefix, sizeof(prefix), "%-6s %2s", reqIDStr, req->primary ? "->" : ""); if (!req->terminate) LogToFD(fd, "%s No operation yet on this socket", prefix); else if (req->terminate == connection_termination) { int num_records = 0, num_ops = 0; const registered_record_entry *p; request_state *r; for (p = req->u.reg_recs; p; p=p->next) num_records++; for (r = req->next; r; r=r->next) if (r->primary == req) num_ops++; LogToFD(fd, "%s DNSServiceCreateConnection: %d registered record%s, %d kDNSServiceFlagsShareConnection operation%s PID[%d](%s)", prefix, num_records, num_records != 1 ? "s" : "", num_ops, num_ops != 1 ? "s" : "", req->process_id, req->pid_name); for (p = req->u.reg_recs; p; p=p->next) LogToFD(fd, " -> DNSServiceRegisterRecord 0x%08X %2d %3d %s PID[%d](%s)", req->flags, req->interfaceIndex, p->key, ARDisplayString(&mDNSStorage, p->rr), req->process_id, req->pid_name); for (r = req->next; r; r=r->next) if (r->primary == req) LogClientInfoToFD(fd, r); } else if (req->terminate == regservice_termination_callback) { service_instance *ptr; for (ptr = req->u.servicereg.instances; ptr; ptr = ptr->next) LogToFD(fd, "%-9s DNSServiceRegister 0x%08X %2d %##s %u/%u PID[%d](%s)", (ptr == req->u.servicereg.instances) ? prefix : "", req->flags, req->interfaceIndex, ptr->srs.RR_SRV.resrec.name->c, mDNSVal16(req->u.servicereg.port), SRS_PORT(&ptr->srs), req->process_id, req->pid_name); } else if (req->terminate == browse_termination_callback) { browser_t *blist; for (blist = req->u.browser.browsers; blist; blist = blist->next) LogToFD(fd, "%-9s DNSServiceBrowse 0x%08X %2d %##s PID[%d](%s)", (blist == req->u.browser.browsers) ? prefix : "", req->flags, req->interfaceIndex, blist->q.qname.c, req->process_id, req->pid_name); } else if (req->terminate == resolve_termination_callback) LogToFD(fd, "%s DNSServiceResolve 0x%08X %2d %##s PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.resolve.qsrv.qname.c, req->process_id, req->pid_name); else if (req->terminate == queryrecord_termination_callback) LogToFD(fd, "%s DNSServiceQueryRecord 0x%08X %2d %##s (%s) PID[%d](%s)", prefix, req->flags, req->interfaceIndex, QueryRecordClientRequestGetQName(&req->u.queryrecord), DNSTypeName(QueryRecordClientRequestGetType(&req->u.queryrecord)), req->process_id, req->pid_name); else if (req->terminate == enum_termination_callback) LogToFD(fd, "%s DNSServiceEnumerateDomains 0x%08X %2d %##s PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.enumeration.q_all.qname.c, req->process_id, req->pid_name); else if (req->terminate == port_mapping_termination_callback) LogToFD(fd, "%s DNSServiceNATPortMapping 0x%08X %2d %s%s Int %5d Req %5d Ext %.4a:%5d Req TTL %5d Granted TTL %5d PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.pm.NATinfo.Protocol & NATOp_MapTCP ? "TCP" : " ", req->u.pm.NATinfo.Protocol & NATOp_MapUDP ? "UDP" : " ", mDNSVal16(req->u.pm.NATinfo.IntPort), mDNSVal16(req->u.pm.ReqExt), &req->u.pm.NATinfo.ExternalAddress, mDNSVal16(req->u.pm.NATinfo.ExternalPort), req->u.pm.NATinfo.NATLease, req->u.pm.NATinfo.Lifetime, req->process_id, req->pid_name); else if (req->terminate == addrinfo_termination_callback) LogToFD(fd, "%s DNSServiceGetAddrInfo 0x%08X %2d %s%s %##s PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.addrinfo.protocols & kDNSServiceProtocol_IPv4 ? "v4" : " ", req->u.addrinfo.protocols & kDNSServiceProtocol_IPv6 ? "v6" : " ", GetAddrInfoClientRequestGetQName(&req->u.addrinfo), req->process_id, req->pid_name); else LogToFD(fd, "%s Unrecognized operation %p", prefix, req->terminate); } mDNSlocal void LogClientInfo(request_state *req) { char reqIDStr[14]; char prefix[18]; mDNS_snprintf(reqIDStr, sizeof(reqIDStr), "[R%u]", req->request_id); mDNS_snprintf(prefix, sizeof(prefix), "%-6s %2s", reqIDStr, req->primary ? "->" : ""); if (!req->terminate) LogMsgNoIdent("%s No operation yet on this socket", prefix); else if (req->terminate == connection_termination) { int num_records = 0, num_ops = 0; const registered_record_entry *p; request_state *r; for (p = req->u.reg_recs; p; p=p->next) num_records++; for (r = req->next; r; r=r->next) if (r->primary == req) num_ops++; LogMsgNoIdent("%s DNSServiceCreateConnection: %d registered record%s, %d kDNSServiceFlagsShareConnection operation%s PID[%d](%s)", prefix, num_records, num_records != 1 ? "s" : "", num_ops, num_ops != 1 ? "s" : "", req->process_id, req->pid_name); for (p = req->u.reg_recs; p; p=p->next) LogMsgNoIdent(" -> DNSServiceRegisterRecord 0x%08X %2d %3d %s PID[%d](%s)", req->flags, req->interfaceIndex, p->key, ARDisplayString(&mDNSStorage, p->rr), req->process_id, req->pid_name); for (r = req->next; r; r=r->next) if (r->primary == req) LogClientInfo(r); } else if (req->terminate == regservice_termination_callback) { service_instance *ptr; for (ptr = req->u.servicereg.instances; ptr; ptr = ptr->next) LogMsgNoIdent("%-9s DNSServiceRegister 0x%08X %2d %##s %u/%u PID[%d](%s)", (ptr == req->u.servicereg.instances) ? prefix : "", req->flags, req->interfaceIndex, ptr->srs.RR_SRV.resrec.name->c, mDNSVal16(req->u.servicereg.port), SRS_PORT(&ptr->srs), req->process_id, req->pid_name); } else if (req->terminate == browse_termination_callback) { browser_t *blist; for (blist = req->u.browser.browsers; blist; blist = blist->next) LogMsgNoIdent("%-9s DNSServiceBrowse 0x%08X %2d %##s PID[%d](%s)", (blist == req->u.browser.browsers) ? prefix : "", req->flags, req->interfaceIndex, blist->q.qname.c, req->process_id, req->pid_name); } else if (req->terminate == resolve_termination_callback) LogMsgNoIdent("%s DNSServiceResolve 0x%08X %2d %##s PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.resolve.qsrv.qname.c, req->process_id, req->pid_name); else if (req->terminate == queryrecord_termination_callback) LogMsgNoIdent("%s DNSServiceQueryRecord 0x%08X %2d %##s (%s) PID[%d](%s)", prefix, req->flags, req->interfaceIndex, QueryRecordClientRequestGetQName(&req->u.queryrecord), DNSTypeName(QueryRecordClientRequestGetType(&req->u.queryrecord)), req->process_id, req->pid_name); else if (req->terminate == enum_termination_callback) LogMsgNoIdent("%s DNSServiceEnumerateDomains 0x%08X %2d %##s PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.enumeration.q_all.qname.c, req->process_id, req->pid_name); else if (req->terminate == port_mapping_termination_callback) LogMsgNoIdent("%s DNSServiceNATPortMapping 0x%08X %2d %s%s Int %5d Req %5d Ext %.4a:%5d Req TTL %5d Granted TTL %5d PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.pm.NATinfo.Protocol & NATOp_MapTCP ? "TCP" : " ", req->u.pm.NATinfo.Protocol & NATOp_MapUDP ? "UDP" : " ", mDNSVal16(req->u.pm.NATinfo.IntPort), mDNSVal16(req->u.pm.ReqExt), &req->u.pm.NATinfo.ExternalAddress, mDNSVal16(req->u.pm.NATinfo.ExternalPort), req->u.pm.NATinfo.NATLease, req->u.pm.NATinfo.Lifetime, req->process_id, req->pid_name); else if (req->terminate == addrinfo_termination_callback) LogMsgNoIdent("%s DNSServiceGetAddrInfo 0x%08X %2d %s%s %##s PID[%d](%s)", prefix, req->flags, req->interfaceIndex, req->u.addrinfo.protocols & kDNSServiceProtocol_IPv4 ? "v4" : " ", req->u.addrinfo.protocols & kDNSServiceProtocol_IPv6 ? "v6" : " ", GetAddrInfoClientRequestGetQName(&req->u.addrinfo), req->process_id, req->pid_name); else LogMsgNoIdent("%s Unrecognized operation %p", prefix, req->terminate); } mDNSlocal void GetMcastClients(request_state *req) { if (req->terminate == connection_termination) { int num_records = 0, num_ops = 0; const registered_record_entry *p; request_state *r; for (p = req->u.reg_recs; p; p=p->next) num_records++; for (r = req->next; r; r=r->next) if (r->primary == req) num_ops++; for (p = req->u.reg_recs; p; p=p->next) { if (!AuthRecord_uDNS(p->rr)) n_mrecords++; } for (r = req->next; r; r=r->next) if (r->primary == req) GetMcastClients(r); } else if (req->terminate == regservice_termination_callback) { service_instance *ptr; for (ptr = req->u.servicereg.instances; ptr; ptr = ptr->next) { if (!AuthRecord_uDNS(&ptr->srs.RR_SRV)) n_mrecords++; } } else if (req->terminate == browse_termination_callback) { browser_t *blist; for (blist = req->u.browser.browsers; blist; blist = blist->next) { if (mDNSOpaque16IsZero(blist->q.TargetQID)) n_mquests++; } } else if (req->terminate == resolve_termination_callback) { if ((mDNSOpaque16IsZero(req->u.resolve.qsrv.TargetQID)) && (req->u.resolve.qsrv.ThisQInterval > 0)) n_mquests++; } else if (req->terminate == queryrecord_termination_callback) { if (QueryRecordClientRequestIsMulticast(&req->u.queryrecord)) n_mquests++; } else if (req->terminate == addrinfo_termination_callback) { if (GetAddrInfoClientRequestIsMulticast(&req->u.addrinfo)) n_mquests++; } else { return; } } mDNSlocal void LogMcastClientInfo(request_state *req) { if (!req->terminate) LogMcastNoIdent("No operation yet on this socket"); else if (req->terminate == connection_termination) { int num_records = 0, num_ops = 0; const registered_record_entry *p; request_state *r; for (p = req->u.reg_recs; p; p=p->next) num_records++; for (r = req->next; r; r=r->next) if (r->primary == req) num_ops++; for (p = req->u.reg_recs; p; p=p->next) { if (!AuthRecord_uDNS(p->rr)) LogMcastNoIdent("R: -> DNSServiceRegisterRecord: %##s %s PID[%d](%s)", p->rr->resrec.name->c, DNSTypeName(p->rr->resrec.rrtype), req->process_id, req->pid_name, i_mcount++); } for (r = req->next; r; r=r->next) if (r->primary == req) LogMcastClientInfo(r); } else if (req->terminate == regservice_termination_callback) { service_instance *ptr; for (ptr = req->u.servicereg.instances; ptr; ptr = ptr->next) { if (!AuthRecord_uDNS(&ptr->srs.RR_SRV)) LogMcastNoIdent("R: DNSServiceRegister: %##s %u/%u PID[%d](%s)", ptr->srs.RR_SRV.resrec.name->c, mDNSVal16(req->u.servicereg.port), SRS_PORT(&ptr->srs), req->process_id, req->pid_name, i_mcount++); } } else if (req->terminate == browse_termination_callback) { browser_t *blist; for (blist = req->u.browser.browsers; blist; blist = blist->next) { if (mDNSOpaque16IsZero(blist->q.TargetQID)) LogMcastNoIdent("Q: DNSServiceBrowse %##s %s PID[%d](%s)", blist->q.qname.c, DNSTypeName(blist->q.qtype), req->process_id, req->pid_name, i_mcount++); } } else if (req->terminate == resolve_termination_callback) { if ((mDNSOpaque16IsZero(req->u.resolve.qsrv.TargetQID)) && (req->u.resolve.qsrv.ThisQInterval > 0)) LogMcastNoIdent("Q: DNSServiceResolve %##s %s PID[%d](%s)", req->u.resolve.qsrv.qname.c, DNSTypeName(req->u.resolve.qsrv.qtype), req->process_id, req->pid_name, i_mcount++); } else if (req->terminate == queryrecord_termination_callback) { if (QueryRecordClientRequestIsMulticast(&req->u.queryrecord)) { LogMcastNoIdent("Q: DNSServiceQueryRecord %##s %s PID[%d](%s)", QueryRecordClientRequestGetQName(&req->u.queryrecord), DNSTypeName(QueryRecordClientRequestGetType(&req->u.queryrecord)), req->process_id, req->pid_name, i_mcount++); } } else if (req->terminate == addrinfo_termination_callback) { if (GetAddrInfoClientRequestIsMulticast(&req->u.addrinfo)) { LogMcastNoIdent("Q: DNSServiceGetAddrInfo %s%s %##s PID[%d](%s)", req->u.addrinfo.protocols & kDNSServiceProtocol_IPv4 ? "v4" : " ", req->u.addrinfo.protocols & kDNSServiceProtocol_IPv6 ? "v6" : " ", GetAddrInfoClientRequestGetQName(&req->u.addrinfo), req->process_id, req->pid_name, i_mcount++); } } } mDNSlocal char *RecordTypeName(mDNSu8 rtype) { switch (rtype) { case kDNSRecordTypeUnregistered: return ("Unregistered "); case kDNSRecordTypeDeregistering: return ("Deregistering"); case kDNSRecordTypeUnique: return ("Unique "); case kDNSRecordTypeAdvisory: return ("Advisory "); case kDNSRecordTypeShared: return ("Shared "); case kDNSRecordTypeVerified: return ("Verified "); case kDNSRecordTypeKnownUnique: return ("KnownUnique "); default: return("Unknown"); } } mDNSlocal int LogEtcHostsToFD(int fd, mDNS *const m) { mDNSBool showheader = mDNStrue; const AuthRecord *ar; mDNSu32 slot; AuthGroup *ag; int count = 0; int authslot = 0; mDNSBool truncated = 0; for (slot = 0; slot < AUTH_HASH_SLOTS; slot++) { if (m->rrauth.rrauth_hash[slot]) authslot++; for (ag = m->rrauth.rrauth_hash[slot]; ag; ag = ag->next) for (ar = ag->members; ar; ar = ar->next) { if (ar->RecordCallback != FreeEtcHosts) continue; if (showheader) { showheader = mDNSfalse; LogToFD(fd, " State Interface"); } // Print a maximum of 50 records if (count++ >= 50) { truncated = mDNStrue; continue; } if (ar->ARType == AuthRecordLocalOnly) { if (ar->resrec.InterfaceID == mDNSInterface_LocalOnly) LogToFD(fd, " %s LO %s", RecordTypeName(ar->resrec.RecordType), ARDisplayString(m, ar)); else { mDNSu32 scopeid = (mDNSu32)(uintptr_t)ar->resrec.InterfaceID; LogToFD(fd, " %s %u %s", RecordTypeName(ar->resrec.RecordType), scopeid, ARDisplayString(m, ar)); } } } } if (showheader) LogToFD(fd, ""); else if (truncated) LogToFD(fd, "", count, m->rrauth.rrauth_totalused, authslot); return count; } mDNSlocal void LogLocalOnlyAuthRecordsToFD(int fd, mDNS *const m) { mDNSBool showheader = mDNStrue; const AuthRecord *ar; mDNSu32 slot; AuthGroup *ag; for (slot = 0; slot < AUTH_HASH_SLOTS; slot++) { for (ag = m->rrauth.rrauth_hash[slot]; ag; ag = ag->next) for (ar = ag->members; ar; ar = ar->next) { if (ar->RecordCallback == FreeEtcHosts) continue; if (showheader) { showheader = mDNSfalse; LogToFD(fd, " State Interface"); } // Print a maximum of 400 records if (ar->ARType == AuthRecordLocalOnly) LogToFD(fd, " %s LO %s", RecordTypeName(ar->resrec.RecordType), ARDisplayString(m, ar)); else if (ar->ARType == AuthRecordP2P) { if (ar->resrec.InterfaceID == mDNSInterface_BLE) LogToFD(fd, " %s BLE %s", RecordTypeName(ar->resrec.RecordType), ARDisplayString(m, ar)); else LogToFD(fd, " %s PP %s", RecordTypeName(ar->resrec.RecordType), ARDisplayString(m, ar)); } } } if (showheader) LogToFD(fd, ""); } mDNSlocal void LogOneAuthRecordToFD(int fd, const AuthRecord *ar, mDNSs32 now, const char *ifname) { if (AuthRecord_uDNS(ar)) { LogToFD(fd, "%7d %7d %7d %-7s %4d %s %s", ar->ThisAPInterval / mDNSPlatformOneSecond, (ar->LastAPTime + ar->ThisAPInterval - now) / mDNSPlatformOneSecond, ar->expire ? (ar->expire - now) / mDNSPlatformOneSecond : 0, "-U-", ar->state, ar->AllowRemoteQuery ? "☠" : " ", ARDisplayString(&mDNSStorage, ar)); } else { LogToFD(fd, "%7d %7d %7d %-7s 0x%02X %s %s", ar->ThisAPInterval / mDNSPlatformOneSecond, ar->AnnounceCount ? (ar->LastAPTime + ar->ThisAPInterval - now) / mDNSPlatformOneSecond : 0, ar->TimeExpire ? (ar->TimeExpire - now) / mDNSPlatformOneSecond : 0, ifname ? ifname : "ALL", ar->resrec.RecordType, ar->AllowRemoteQuery ? "☠" : " ", ARDisplayString(&mDNSStorage, ar)); } } mDNSlocal void LogAuthRecordsToFD(int fd, const mDNSs32 now, AuthRecord *ResourceRecords, int *proxy) { mDNSBool showheader = mDNStrue; const AuthRecord *ar; OwnerOptData owner = zeroOwner; for (ar = ResourceRecords; ar; ar=ar->next) { const char *const ifname = InterfaceNameForID(&mDNSStorage, ar->resrec.InterfaceID); if ((ar->WakeUp.HMAC.l[0] != 0) == (proxy != mDNSNULL)) { if (showheader) { showheader = mDNSfalse; LogToFD(fd, " Int Next Expire if State"); } if (proxy) (*proxy)++; if (!mDNSPlatformMemSame(&owner, &ar->WakeUp, sizeof(owner))) { owner = ar->WakeUp; if (owner.password.l[0]) LogToFD(fd, "Proxying for H-MAC %.6a I-MAC %.6a Password %.6a seq %d", &owner.HMAC, &owner.IMAC, &owner.password, owner.seq); else if (!mDNSSameEthAddress(&owner.HMAC, &owner.IMAC)) LogToFD(fd, "Proxying for H-MAC %.6a I-MAC %.6a seq %d", &owner.HMAC, &owner.IMAC, owner.seq); else LogToFD(fd, "Proxying for %.6a seq %d", &owner.HMAC, owner.seq); } if (AuthRecord_uDNS(ar)) { LogOneAuthRecordToFD(fd, ar, now, ifname); } else if (ar->ARType == AuthRecordLocalOnly) { LogToFD(fd, " LO %s", ARDisplayString(&mDNSStorage, ar)); } else if (ar->ARType == AuthRecordP2P) { if (ar->resrec.InterfaceID == mDNSInterface_BLE) LogToFD(fd, " BLE %s", ARDisplayString(&mDNSStorage, ar)); else LogToFD(fd, " PP %s", ARDisplayString(&mDNSStorage, ar)); } else { LogOneAuthRecordToFD(fd, ar, now, ifname); } } } if (showheader) LogToFD(fd, ""); } mDNSlocal void PrintOneCacheRecordToFD(int fd, const CacheRecord *cr, mDNSu32 slot, const mDNSu32 remain, const char *ifname, mDNSu32 *CacheUsed) { LogToFD(fd, "%3d %s%8d %-7s%s %-6s%s", slot, cr->CRActiveQuestion ? "*" : " ", remain, ifname ? ifname : "-U-", (cr->resrec.RecordType == kDNSRecordTypePacketNegative) ? "-" : (cr->resrec.RecordType & kDNSRecordTypePacketUniqueMask) ? " " : "+", DNSTypeName(cr->resrec.rrtype), CRDisplayString(&mDNSStorage, cr)); (*CacheUsed)++; } mDNSlocal void PrintCachedRecordsToFD(int fd, const CacheRecord *cr, mDNSu32 slot, const mDNSu32 remain, const char *ifname, mDNSu32 *CacheUsed) { CacheRecord *soa; soa = cr->soa; if (soa) { PrintOneCacheRecordToFD(fd, soa, slot, remain, ifname, CacheUsed); } } mDNSexport void LogMDNSStatisticsToFD(int fd, mDNS *const m) { LogToFD(fd, "--- MDNS Statistics ---"); LogToFD(fd, "Name Conflicts %u", m->mDNSStats.NameConflicts); LogToFD(fd, "KnownUnique Name Conflicts %u", m->mDNSStats.KnownUniqueNameConflicts); LogToFD(fd, "Duplicate Query Suppressions %u", m->mDNSStats.DupQuerySuppressions); LogToFD(fd, "KA Suppressions %u", m->mDNSStats.KnownAnswerSuppressions); LogToFD(fd, "KA Multiple Packets %u", m->mDNSStats.KnownAnswerMultiplePkts); LogToFD(fd, "Poof Cache Deletions %u", m->mDNSStats.PoofCacheDeletions); LogToFD(fd, "--------------------------------"); LogToFD(fd, "Multicast packets Sent %u", m->MulticastPacketsSent); LogToFD(fd, "Multicast packets Received %u", m->MPktNum); LogToFD(fd, "Remote Subnet packets %u", m->RemoteSubnet); LogToFD(fd, "QU questions received %u", m->mDNSStats.UnicastBitInQueries); LogToFD(fd, "Normal multicast questions %u", m->mDNSStats.NormalQueries); LogToFD(fd, "Answers for questions %u", m->mDNSStats.MatchingAnswersForQueries); LogToFD(fd, "Unicast responses %u", m->mDNSStats.UnicastResponses); LogToFD(fd, "Multicast responses %u", m->mDNSStats.MulticastResponses); LogToFD(fd, "Unicast response Demotions %u", m->mDNSStats.UnicastDemotedToMulticast); LogToFD(fd, "--------------------------------"); LogToFD(fd, "Sleeps %u", m->mDNSStats.Sleeps); LogToFD(fd, "Wakeups %u", m->mDNSStats.Wakes); LogToFD(fd, "Interface UP events %u", m->mDNSStats.InterfaceUp); LogToFD(fd, "Interface UP Flap events %u", m->mDNSStats.InterfaceUpFlap); LogToFD(fd, "Interface Down events %u", m->mDNSStats.InterfaceDown); LogToFD(fd, "Interface DownFlap events %u", m->mDNSStats.InterfaceDownFlap); LogToFD(fd, "Cache refresh queries %u", m->mDNSStats.CacheRefreshQueries); LogToFD(fd, "Cache refreshed %u", m->mDNSStats.CacheRefreshed); LogToFD(fd, "Wakeup on Resolves %u", m->mDNSStats.WakeOnResolves); } mDNSexport void udsserver_info_dump_to_fd(int fd) { mDNS *const m = &mDNSStorage; const mDNSs32 now = mDNS_TimeNow(m); mDNSu32 CacheUsed = 0, CacheActive = 0, slot; int ProxyA = 0, ProxyD = 0; mDNSu32 groupCount = 0; mDNSu32 mcastRecordCount = 0; mDNSu32 ucastRecordCount = 0; const CacheGroup *cg; const CacheRecord *cr; const DNSQuestion *q; const DNameListElem *d; const SearchListElem *s; LogToFD(fd, "------------ Cache -------------"); LogToFD(fd, "Slt Q TTL if U Type rdlen"); for (slot = 0; slot < CACHE_HASH_SLOTS; slot++) { for (cg = m->rrcache_hash[slot]; cg; cg=cg->next) { groupCount++; // Count one cache entity for the CacheGroup object for (cr = cg->members; cr; cr=cr->next) { const mDNSs32 remain = cr->resrec.rroriginalttl - (now - cr->TimeRcvd) / mDNSPlatformOneSecond; const char *ifname; mDNSInterfaceID InterfaceID = cr->resrec.InterfaceID; mDNSu32 *const countPtr = InterfaceID ? &mcastRecordCount : &ucastRecordCount; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) if (!InterfaceID && cr->resrec.dnsservice && (mdns_dns_service_get_scope(cr->resrec.dnsservice) == mdns_dns_service_scope_interface)) { InterfaceID = (mDNSInterfaceID)(uintptr_t)mdns_dns_service_get_interface_index(cr->resrec.dnsservice); } #else if (!InterfaceID && cr->resrec.rDNSServer && cr->resrec.rDNSServer->scopeType) InterfaceID = cr->resrec.rDNSServer->interface; #endif ifname = InterfaceNameForID(m, InterfaceID); if (cr->CRActiveQuestion) CacheActive++; PrintOneCacheRecordToFD(fd, cr, slot, remain, ifname, countPtr); PrintCachedRecordsToFD(fd, cr, slot, remain, ifname, countPtr); } } } CacheUsed = groupCount + mcastRecordCount + ucastRecordCount; if (m->rrcache_totalused != CacheUsed) LogToFD(fd, "Cache use mismatch: rrcache_totalused is %lu, true count %lu", m->rrcache_totalused, CacheUsed); if (m->rrcache_active != CacheActive) LogToFD(fd, "Cache use mismatch: rrcache_active is %lu, true count %lu", m->rrcache_active, CacheActive); LogToFD(fd, "Cache size %u entities; %u in use (%u group, %u multicast, %u unicast); %u referenced by active questions", m->rrcache_size, CacheUsed, groupCount, mcastRecordCount, ucastRecordCount, CacheActive); LogToFD(fd, "--------- Auth Records ---------"); LogAuthRecordsToFD(fd, now, m->ResourceRecords, mDNSNULL); LogToFD(fd, "--------- LocalOnly, P2P Auth Records ---------"); LogLocalOnlyAuthRecordsToFD(fd, m); LogToFD(fd, "--------- /etc/hosts ---------"); LogEtcHostsToFD(fd, m); LogToFD(fd, "------ Duplicate Records -------"); LogAuthRecordsToFD(fd, now, m->DuplicateRecords, mDNSNULL); LogToFD(fd, "----- Auth Records Proxied -----"); LogAuthRecordsToFD(fd, now, m->ResourceRecords, &ProxyA); LogToFD(fd, "-- Duplicate Records Proxied ---"); LogAuthRecordsToFD(fd, now, m->DuplicateRecords, &ProxyD); LogToFD(fd, "---------- Questions -----------"); if (!m->Questions) LogToFD(fd, ""); else { CacheUsed = 0; CacheActive = 0; LogToFD(fd, " Int Next if T NumAns VDNS Qptr DupOf SU SQ Type Name"); for (q = m->Questions; q; q=q->next) { mDNSs32 i = q->ThisQInterval / mDNSPlatformOneSecond; mDNSs32 n = (NextQSendTime(q) - now) / mDNSPlatformOneSecond; char *ifname = InterfaceNameForID(m, q->InterfaceID); CacheUsed++; if (q->ThisQInterval) CacheActive++; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) LogToFD(fd, "%6d%6d %-7s%s %5d 0x%p 0x%p %1d %2d %-5s%##s%s", #else LogToFD(fd, "%6d%6d %-7s%s %5d 0x%08x%08x%08x%08x 0x%p 0x%p %1d %2d %-5s%##s%s", #endif i, n, ifname ? ifname : mDNSOpaque16IsZero(q->TargetQID) ? "" : "-U-", mDNSOpaque16IsZero(q->TargetQID) ? (q->LongLived ? "l" : " ") : (q->LongLived ? "L" : "O"), q->CurrentAnswers, #if !MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) q->validDNSServers.l[3], q->validDNSServers.l[2], q->validDNSServers.l[1], q->validDNSServers.l[0], #endif q, q->DuplicateOf, q->SuppressUnusable, q->Suppressed, DNSTypeName(q->qtype), q->qname.c, q->DuplicateOf ? " (dup)" : ""); } LogToFD(fd, "%lu question%s; %lu active", CacheUsed, CacheUsed > 1 ? "s" : "", CacheActive); } LogToFD(fd, "----- LocalOnly, P2P Questions -----"); if (!m->LocalOnlyQuestions) LogToFD(fd, ""); else for (q = m->LocalOnlyQuestions; q; q=q->next) LogToFD(fd, " %3s %5d %-6s%##s%s", q->InterfaceID == mDNSInterface_LocalOnly ? "LO ": q->InterfaceID == mDNSInterface_BLE ? "BLE": "P2P", q->CurrentAnswers, DNSTypeName(q->qtype), q->qname.c, q->DuplicateOf ? " (dup)" : ""); LogToFD(fd, "---- Active UDS Client Requests ----"); if (!all_requests) LogToFD(fd, ""); else { request_state *req, *r; for (req = all_requests; req; req=req->next) { if (req->primary) // If this is a subbordinate operation, check that the parent is in the list { for (r = all_requests; r && r != req; r=r->next) if (r == req->primary) goto foundparent; LogToFD(fd, "%3d: Orhpan operation %p; parent %p not found in request list", req->sd); } // For non-subbordinate operations, and subbordinate operations that have lost their parent, write out their info LogClientInfoToFD(fd, req); foundparent:; } } LogToFD(fd, "-------- NAT Traversals --------"); LogToFD(fd, "ExtAddress %.4a Retry %d Interval %d", &m->ExtAddress, m->retryGetAddr ? (m->retryGetAddr - now) / mDNSPlatformOneSecond : 0, m->retryIntervalGetAddr / mDNSPlatformOneSecond); if (m->NATTraversals) { const NATTraversalInfo *nat; for (nat = m->NATTraversals; nat; nat=nat->next) { LogToFD(fd, "%p %s Int %5d %s Err %d Retry %5d Interval %5d Expire %5d Req %.4a:%d Ext %.4a:%d", nat, nat->Protocol ? (nat->Protocol == NATOp_MapTCP ? "TCP" : "UDP") : "ADD", mDNSVal16(nat->IntPort), (nat->lastSuccessfulProtocol == NATTProtocolNone ? "None " : nat->lastSuccessfulProtocol == NATTProtocolNATPMP ? "NAT-PMP " : nat->lastSuccessfulProtocol == NATTProtocolUPNPIGD ? "UPnP/IGD" : nat->lastSuccessfulProtocol == NATTProtocolPCP ? "PCP " : /* else */ "Unknown " ), nat->Result, nat->retryPortMap ? (nat->retryPortMap - now) / mDNSPlatformOneSecond : 0, nat->retryInterval / mDNSPlatformOneSecond, nat->ExpiryTime ? (nat->ExpiryTime - now) / mDNSPlatformOneSecond : 0, &nat->NewAddress, mDNSVal16(nat->RequestedPort), &nat->ExternalAddress, mDNSVal16(nat->ExternalPort)); } } LogToFD(fd, "--------- AuthInfoList ---------"); if (!m->AuthInfoList) LogToFD(fd, ""); else { const DomainAuthInfo *a; for (a = m->AuthInfoList; a; a = a->next) { LogToFD(fd, "%##s %##s %##s %d %d", a->domain.c, a->keyname.c, a->hostname.c, (a->port.b[0] << 8 | a->port.b[1]), (a->deltime ? (a->deltime - now) : 0)); } } LogToFD(fd, "---------- Misc State ----------"); LogToFD(fd, "PrimaryMAC: %.6a", &m->PrimaryMAC); LogToFD(fd, "m->SleepState %d (%s) seq %d", m->SleepState, m->SleepState == SleepState_Awake ? "Awake" : m->SleepState == SleepState_Transferring ? "Transferring" : m->SleepState == SleepState_Sleeping ? "Sleeping" : "?", m->SleepSeqNum); if (!m->SPSSocket) LogToFD(fd, "Not offering Sleep Proxy Service"); #ifndef SPC_DISABLED else LogToFD(fd, "Offering Sleep Proxy Service: %#s", m->SPSRecords.RR_SRV.resrec.name->c); #endif if (m->ProxyRecords == ProxyA + ProxyD) LogToFD(fd, "ProxyRecords: %d + %d = %d", ProxyA, ProxyD, ProxyA + ProxyD); else LogToFD(fd, "ProxyRecords: MISMATCH %d + %d = %d ≠ %d", ProxyA, ProxyD, ProxyA + ProxyD, m->ProxyRecords); LogToFD(fd, "------ Auto Browse Domains -----"); if (!AutoBrowseDomains) LogToFD(fd, ""); else for (d=AutoBrowseDomains; d; d=d->next) LogToFD(fd, "%##s", d->name.c); LogToFD(fd, "--- Auto Registration Domains --"); if (!AutoRegistrationDomains) LogToFD(fd, ""); else for (d=AutoRegistrationDomains; d; d=d->next) LogToFD(fd, "%##s", d->name.c); LogToFD(fd, "--- Search Domains --"); if (!SearchList) LogToFD(fd, ""); else { for (s=SearchList; s; s=s->next) { char *ifname = InterfaceNameForID(m, s->InterfaceID); LogToFD(fd, "%##s %s", s->domain.c, ifname ? ifname : ""); } } LogMDNSStatisticsToFD(fd, m); LogToFD(fd, "---- Task Scheduling Timers ----"); #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) LogToFD(fd, "BonjourEnabled %d", m->BonjourEnabled); #endif #if APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR LogToFD(fd, "EnableBLEBasedDiscovery %d", EnableBLEBasedDiscovery); LogToFD(fd, "DefaultToBLETriggered %d", DefaultToBLETriggered); #endif // APPLE_OSX_mDNSResponder && ENABLE_BLE_TRIGGERED_BONJOUR if (!m->NewQuestions) LogToFD(fd, "NewQuestion "); else LogToFD(fd, "NewQuestion DelayAnswering %d %d %##s (%s)", m->NewQuestions->DelayAnswering, m->NewQuestions->DelayAnswering-now, m->NewQuestions->qname.c, DNSTypeName(m->NewQuestions->qtype)); if (!m->NewLocalOnlyQuestions) LogToFD(fd, "NewLocalOnlyQuestions "); else LogToFD(fd, "NewLocalOnlyQuestions %##s (%s)", m->NewLocalOnlyQuestions->qname.c, DNSTypeName(m->NewLocalOnlyQuestions->qtype)); if (!m->NewLocalRecords) LogToFD(fd, "NewLocalRecords "); else LogToFD(fd, "NewLocalRecords %02X %s", m->NewLocalRecords->resrec.RecordType, ARDisplayString(m, m->NewLocalRecords)); LogToFD(fd, "SPSProxyListChanged%s", m->SPSProxyListChanged ? "" : " "); LogToFD(fd, "LocalRemoveEvents%s", m->LocalRemoveEvents ? "" : " "); LogToFD(fd, "m->WABBrowseQueriesCount %d", m->WABBrowseQueriesCount); LogToFD(fd, "m->WABLBrowseQueriesCount %d", m->WABLBrowseQueriesCount); LogToFD(fd, "m->WABRegQueriesCount %d", m->WABRegQueriesCount); LogToFD(fd, "m->AutoTargetServices %u", m->AutoTargetServices); #if MDNSRESPONDER_SUPPORTS(APPLE, RANDOM_AWDL_HOSTNAME) LogToFD(fd, "m->AutoTargetAWDLIncludedCount %u", m->AutoTargetAWDLIncludedCount); LogToFD(fd, "m->AutoTargetAWDLOnlyCount %u", m->AutoTargetAWDLOnlyCount); #endif LogToFD(fd, " ABS (hex) ABS (dec) REL (hex) REL (dec)"); LogToFD(fd, "m->timenow %08X %11d", now, now); LogToFD(fd, "m->timenow_adjust %08X %11d", m->timenow_adjust, m->timenow_adjust); LogTimerToFD(fd, "m->NextScheduledEvent ", m->NextScheduledEvent); #ifndef UNICAST_DISABLED LogTimerToFD(fd, "m->NextuDNSEvent ", m->NextuDNSEvent); LogTimerToFD(fd, "m->NextSRVUpdate ", m->NextSRVUpdate); LogTimerToFD(fd, "m->NextScheduledNATOp ", m->NextScheduledNATOp); LogTimerToFD(fd, "m->retryGetAddr ", m->retryGetAddr); #endif LogTimerToFD(fd, "m->NextCacheCheck ", m->NextCacheCheck); LogTimerToFD(fd, "m->NextScheduledSPS ", m->NextScheduledSPS); LogTimerToFD(fd, "m->NextScheduledKA ", m->NextScheduledKA); #if MDNSRESPONDER_SUPPORTS(APPLE, BONJOUR_ON_DEMAND) LogTimerToFD(fd, "m->NextBonjourDisableTime ", m->NextBonjourDisableTime); #endif LogTimerToFD(fd, "m->NextScheduledSPRetry ", m->NextScheduledSPRetry); LogTimerToFD(fd, "m->DelaySleep ", m->DelaySleep); LogTimerToFD(fd, "m->NextScheduledQuery ", m->NextScheduledQuery); LogTimerToFD(fd, "m->NextScheduledProbe ", m->NextScheduledProbe); LogTimerToFD(fd, "m->NextScheduledResponse", m->NextScheduledResponse); LogTimerToFD(fd, "m->SuppressSending ", m->SuppressSending); LogTimerToFD(fd, "m->SuppressProbes ", m->SuppressProbes); LogTimerToFD(fd, "m->ProbeFailTime ", m->ProbeFailTime); LogTimerToFD(fd, "m->DelaySleep ", m->DelaySleep); LogTimerToFD(fd, "m->SleepLimit ", m->SleepLimit); LogTimerToFD(fd, "m->NextScheduledStopTime ", m->NextScheduledStopTime); } #if MDNS_MALLOC_DEBUGGING mDNSlocal void udsserver_validatelists(void *context) { const request_state *req, *p; (void)context; // unused for (req = all_requests; req; req=req->next) { if (req->next == (request_state *)~0 || (req->sd < 0 && req->sd != -2)) LogMemCorruption("UDS request list: %p is garbage (%d)", req, req->sd); if (req->primary == req) LogMemCorruption("UDS request list: req->primary should not point to self %p/%d", req, req->sd); if (req->primary && req->replies) LogMemCorruption("UDS request list: Subordinate request %p/%d/%p should not have replies (%p)", req, req->sd, req->primary && req->replies); p = req->primary; if ((long)p & 3) LogMemCorruption("UDS request list: req %p primary %p is misaligned (%d)", req, p, req->sd); else if (p && (p->next == (request_state *)~0 || (p->sd < 0 && p->sd != -2))) LogMemCorruption("UDS request list: req %p primary %p is garbage (%d)", req, p, p->sd); reply_state *rep; for (rep = req->replies; rep; rep=rep->next) if (rep->next == (reply_state *)~0) LogMemCorruption("UDS req->replies: %p is garbage", rep); if (req->terminate == connection_termination) { registered_record_entry *r; for (r = req->u.reg_recs; r; r=r->next) if (r->next == (registered_record_entry *)~0) LogMemCorruption("UDS req->u.reg_recs: %p is garbage", r); } else if (req->terminate == regservice_termination_callback) { service_instance *s; for (s = req->u.servicereg.instances; s; s=s->next) if (s->next == (service_instance *)~0) LogMemCorruption("UDS req->u.servicereg.instances: %p is garbage", s); } else if (req->terminate == browse_termination_callback) { browser_t *b; for (b = req->u.browser.browsers; b; b=b->next) if (b->next == (browser_t *)~0) LogMemCorruption("UDS req->u.browser.browsers: %p is garbage", b); } } DNameListElem *d; for (d = SCPrefBrowseDomains; d; d=d->next) if (d->next == (DNameListElem *)~0 || d->name.c[0] > 63) LogMemCorruption("SCPrefBrowseDomains: %p is garbage (%d)", d, d->name.c[0]); ARListElem *b; for (b = LocalDomainEnumRecords; b; b=b->next) if (b->next == (ARListElem *)~0 || b->ar.resrec.name->c[0] > 63) LogMemCorruption("LocalDomainEnumRecords: %p is garbage (%d)", b, b->ar.resrec.name->c[0]); for (d = AutoBrowseDomains; d; d=d->next) if (d->next == (DNameListElem *)~0 || d->name.c[0] > 63) LogMemCorruption("AutoBrowseDomains: %p is garbage (%d)", d, d->name.c[0]); for (d = AutoRegistrationDomains; d; d=d->next) if (d->next == (DNameListElem *)~0 || d->name.c[0] > 63) LogMemCorruption("AutoRegistrationDomains: %p is garbage (%d)", d, d->name.c[0]); } #endif // MDNS_MALLOC_DEBUGGING mDNSlocal int send_msg(request_state *const req) { reply_state *const rep = req->replies; // Send the first waiting reply ssize_t nwriten; ConvertHeaderBytes(rep->mhdr); nwriten = send(req->sd, (char *)&rep->mhdr + rep->nwriten, rep->totallen - rep->nwriten, 0); ConvertHeaderBytes(rep->mhdr); if (nwriten < 0) { if (dnssd_errno == dnssd_EINTR || dnssd_errno == dnssd_EWOULDBLOCK) nwriten = 0; else { #if !defined(PLATFORM_NO_EPIPE) if (dnssd_errno == EPIPE) return(req->ts = t_terminated); else #endif { LogMsg("send_msg ERROR: failed to write %d of %d bytes to fd %d errno %d (%s)", rep->totallen - rep->nwriten, rep->totallen, req->sd, dnssd_errno, dnssd_strerror(dnssd_errno)); return(t_error); } } } rep->nwriten += nwriten; return (rep->nwriten == rep->totallen) ? t_complete : t_morecoming; } mDNSexport mDNSs32 udsserver_idle(mDNSs32 nextevent) { mDNSs32 now = mDNS_TimeNow(&mDNSStorage); request_state **req = &all_requests; while (*req) { request_state *const r = *req; if (r->terminate == resolve_termination_callback) if (r->u.resolve.ReportTime && now - r->u.resolve.ReportTime >= 0) { r->u.resolve.ReportTime = 0; // if client received results and resolve still active if (r->u.resolve.txt && r->u.resolve.srv) LogMsgNoIdent("Client application PID[%d](%s) has received results for DNSServiceResolve(%##s) yet remains active over two minutes.", r->process_id, r->pid_name, r->u.resolve.qsrv.qname.c); } // Note: Only primary req's have reply lists, not subordinate req's. while (r->replies) // Send queued replies { transfer_state result; if (r->replies->next) r->replies->rhdr->flags |= dnssd_htonl(kDNSServiceFlagsMoreComing); result = send_msg(r); // Returns t_morecoming if buffer full because client is not reading if (result == t_complete) { reply_state *fptr = r->replies; r->replies = r->replies->next; freeL("reply_state/udsserver_idle", fptr); r->time_blocked = 0; // reset failure counter after successful send r->unresponsiveness_reports = 0; continue; } else if (result == t_terminated) { LogInfo("%3d: Could not write data to client PID[%d](%s) because connection is terminated by the client", r->sd, r->process_id, r->pid_name); abort_request(r); } else if (result == t_error) { LogMsg("%3d: Could not write data to client PID[%d](%s) because of error - aborting connection", r->sd, r->process_id, r->pid_name); LogClientInfo(r); abort_request(r); } break; } if (r->replies) // If we failed to send everything, check our time_blocked timer { if (nextevent - now > mDNSPlatformOneSecond) nextevent = now + mDNSPlatformOneSecond; LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_INFO, "[R%u] Could not send all replies. Will try again in %d ticks.", r->request_id, nextevent - now); if (mDNSStorage.SleepState != SleepState_Awake) r->time_blocked = 0; else if (!r->time_blocked) r->time_blocked = NonZeroTime(now); else if (now - r->time_blocked >= 10 * mDNSPlatformOneSecond * (r->unresponsiveness_reports+1)) { int num = 0; struct reply_state *x = r->replies; while (x) { num++; x=x->next; } LogMsg("%3d: Could not write data to client PID[%d](%s) after %ld seconds, %d repl%s waiting", r->sd, r->process_id, r->pid_name, (now - r->time_blocked) / mDNSPlatformOneSecond, num, num == 1 ? "y" : "ies"); if (++r->unresponsiveness_reports >= 60) { LogMsg("%3d: Client PID[%d](%s) unresponsive; aborting connection", r->sd, r->process_id, r->pid_name); LogClientInfo(r); abort_request(r); } } } if (!dnssd_SocketValid(r->sd)) // If this request is finished, unlink it from the list and free the memory { // Since we're already doing a list traversal, we unlink the request directly instead of using AbortUnlinkAndFree() *req = r->next; freeL("request_state/udsserver_idle", r); } else req = &r->next; } return nextevent; } struct CompileTimeAssertionChecks_uds_daemon { // Check our structures are reasonable sizes. Including overly-large buffers, or embedding // other overly-large structures instead of having a pointer to them, can inadvertently // cause structure sizes (and therefore memory usage) to balloon unreasonably. char sizecheck_request_state [(sizeof(request_state) <= 3880) ? 1 : -1]; char sizecheck_registered_record_entry[(sizeof(registered_record_entry) <= 60) ? 1 : -1]; char sizecheck_service_instance [(sizeof(service_instance) <= 6552) ? 1 : -1]; char sizecheck_browser_t [(sizeof(browser_t) <= 1480) ? 1 : -1]; char sizecheck_reply_hdr [(sizeof(reply_hdr) <= 12) ? 1 : -1]; char sizecheck_reply_state [(sizeof(reply_state) <= 64) ? 1 : -1]; }; #ifdef UNIT_TEST #include "../unittests/uds_daemon_ut.c" #endif // UNIT_TEST /* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2002-2020 Apple Inc. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef UDS_DAEMON_H #define UDS_DAEMON_H #include "mDNSEmbeddedAPI.h" #include "dnssd_ipc.h" #include "ClientRequests.h" #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) #include "mdns_private.h" #endif /* Client request: */ // *************************************************************************** #if COMPILER_LIKES_PRAGMA_MARK #pragma mark - #pragma mark - Types and Data Structures #endif typedef enum { t_uninitialized, t_morecoming, t_complete, t_error, t_terminated } transfer_state; typedef struct request_state request_state; typedef void (*req_termination_fn)(request_state *request); typedef struct registered_record_entry { struct registered_record_entry *next; mDNSu32 key; client_context_t regrec_client_context; request_state *request; mDNSBool external_advertise; mDNSInterfaceID origInterfaceID; AuthRecord *rr; // Pointer to variable-sized AuthRecord (Why a pointer? Why not just embed it here?) } registered_record_entry; // A single registered service: ServiceRecordSet + bookkeeping // Note that we duplicate some fields from parent service_info object // to facilitate cleanup, when instances and parent may be deallocated at different times. typedef struct service_instance { struct service_instance *next; request_state *request; AuthRecord *subtypes; mDNSBool renameonmemfree; // Set on config change when we deregister original name mDNSBool clientnotified; // Has client been notified of successful registration yet? mDNSBool default_local; // is this the "local." from an empty-string registration? mDNSBool external_advertise; // is this is being advertised externally? domainname domain; ServiceRecordSet srs; // note -- variable-sized object -- must be last field in struct } service_instance; // for multi-domain default browsing typedef struct browser_t { struct browser_t *next; domainname domain; DNSQuestion q; } browser_t; #ifdef _WIN32 typedef unsigned int pid_t; typedef unsigned int socklen_t; #endif #if (!defined(MAXCOMLEN)) #define MAXCOMLEN 16 #endif struct request_state { request_state *next; request_state *primary; // If this operation is on a shared socket, pointer to primary // request_state for the original DNSServiceCreateConnection() operation dnssd_sock_t sd; pid_t process_id; // Client's PID value char pid_name[MAXCOMLEN]; // Client's process name mDNSu8 uuid[UUID_SIZE]; mDNSBool validUUID; dnssd_sock_t errsd; #if MDNSRESPONDER_SUPPORTS(APPLE, AUDIT_TOKEN) audit_token_t audit_token; #endif mDNSu32 uid; mDNSu32 request_id; void * platform_data; #if MDNSRESPONDER_SUPPORTS(APPLE, TRUST_ENFORCEMENT) mdns_trust_t trust; #endif // Note: On a shared connection these fields in the primary structure, including hdr, are re-used // for each new request. This is because, until we've read the ipc_msg_hdr to find out what the // operation is, we don't know if we're going to need to allocate a new request_state or not. transfer_state ts; mDNSu32 hdr_bytes; // bytes of header already read ipc_msg_hdr hdr; mDNSu32 data_bytes; // bytes of message data already read char *msgbuf; // pointer to data storage to pass to free() const char *msgptr; // pointer to data to be read from (may be modified) char *msgend; // pointer to byte after last byte of message // reply, termination, error, and client context info int no_reply; // don't send asynchronous replies to client mDNSs32 time_blocked; // record time of a blocked client int unresponsiveness_reports; struct reply_state *replies; // corresponding (active) reply list req_termination_fn terminate; DNSServiceFlags flags; mDNSu32 interfaceIndex; #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) mdns_dns_service_id_t custom_service_id; #endif union { registered_record_entry *reg_recs; // list of registrations for a connection-oriented request struct { mDNSInterfaceID interface_id; mDNSBool default_domain; mDNSBool ForceMCast; domainname regtype; browser_t *browsers; } browser; struct { mDNSInterfaceID InterfaceID; mDNSu16 txtlen; void *txtdata; mDNSIPPort port; domainlabel name; char type_as_string[MAX_ESCAPED_DOMAIN_NAME]; domainname type; mDNSBool default_domain; domainname host; mDNSBool autoname; // Set if this name is tied to the Computer Name mDNSBool autorename; // Set if this client wants us to automatically rename on conflict mDNSBool allowremotequery; // Respond to unicast queries from outside the local link? int num_subtypes; service_instance *instances; } servicereg; struct { mDNSIPPort ReqExt; // External port we originally requested, for logging purposes NATTraversalInfo NATinfo; } pm; struct { DNSServiceFlags flags; DNSQuestion q_all; DNSQuestion q_default; DNSQuestion q_autoall; } enumeration; struct { DNSQuestion qtxt; DNSQuestion qsrv; const ResourceRecord *txt; const ResourceRecord *srv; mDNSs32 ReportTime; mDNSBool external_advertise; } resolve; GetAddrInfoClientRequest addrinfo; QueryRecordClientRequest queryrecord; } u; }; // struct physically sits between ipc message header and call-specific fields in the message buffer typedef struct { DNSServiceFlags flags; // Note: This field is in NETWORK byte order mDNSu32 ifi; // Note: This field is in NETWORK byte order DNSServiceErrorType error; // Note: This field is in NETWORK byte order } reply_hdr; typedef struct reply_state { struct reply_state *next; // If there are multiple unsent replies mDNSu32 totallen; mDNSu32 nwriten; ipc_msg_hdr mhdr[1]; reply_hdr rhdr[1]; } reply_state; /* Client interface: */ #define SRS_PORT(S) mDNSVal16((S)->RR_SRV.resrec.rdata->u.srv.port) #define LogTimerToFD(FILE_DESCRIPTOR, MSG, T) LogToFD((FILE_DESCRIPTOR), MSG " %08X %11d %08X %11d", (T), (T), (T)-now, (T)-now) extern int udsserver_init(dnssd_sock_t skts[], size_t count); extern mDNSs32 udsserver_idle(mDNSs32 nextevent); extern void udsserver_info_dump_to_fd(int fd); extern void udsserver_handle_configchange(mDNS *const m); extern int udsserver_exit(void); // should be called prior to app exit extern void LogMcastStateInfo(mDNSBool mflag, mDNSBool start, mDNSBool mstatelog); #define LogMcastQ (mDNS_McastLoggingEnabled == 0) ? ((void)0) : LogMcastQuestion #define LogMcastS (mDNS_McastLoggingEnabled == 0) ? ((void)0) : LogMcastService #define LogMcast (mDNS_McastLoggingEnabled == 0) ? ((void)0) : LogMsg #define LogMcastNoIdent (mDNS_McastLoggingEnabled == 0) ? ((void)0) : LogMsgNoIdent /* Routines that uds_daemon expects to link against: */ typedef void (*udsEventCallback)(int fd, void *context); extern mStatus udsSupportAddFDToEventLoop(dnssd_sock_t fd, udsEventCallback callback, void *context, void **platform_data); extern int udsSupportReadFD(dnssd_sock_t fd, char* buf, int len, int flags, void *platform_data); extern mStatus udsSupportRemoveFDFromEventLoop(dnssd_sock_t fd, void *platform_data); // Note: This also CLOSES the file descriptor as well extern void RecordUpdatedNiceLabel(mDNSs32 delay); // Globals and functions defined in uds_daemon.c and also shared with the old "daemon.c" on OS X extern mDNS mDNSStorage; extern DNameListElem *AutoRegistrationDomains; extern DNameListElem *AutoBrowseDomains; extern int CountExistingRegistrations(domainname *srv, mDNSIPPort port); extern void FreeExtraRR(mDNS *const m, AuthRecord *const rr, mStatus result); extern int CountPeerRegistrations(ServiceRecordSet *const srs); extern const char mDNSResponderVersionString_SCCS[]; #define mDNSResponderVersionString (mDNSResponderVersionString_SCCS+5) #if DEBUG extern void SetDebugBoundPath(void); extern int IsDebugSocketInUse(void); #endif #endif /* UDS_DAEMON_H */