common - zygaena/hammerhead

root / base / usr / src / cmd / fs.d / pcfs / common
common Plain Text 1010 lines 26.7 KB
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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
 */
/*
 * Copyright (c) 1999 by Sun Microsystems, Inc.
 * All rights reserved.
 * Copyright 2024 MNX Cloud, Inc.
 */

#ifndef _PCFS_BPB_H
#define	_PCFS_BPB_H

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Common Bios Parameter Block definitions for the pcfs user-level utilities
 */
#define	MINBPS		512
#define	MAXBPS		4096

#define	OPCODE1		0xE9
#define	OPCODE2		0xEB
#define	BOOTSECSIG	0xAA55

/*
 * Offset (in bytes) from address of boot sector to where we put
 * the backup copy of that sector.  (FAT32 only)
 */
#define	BKUP_BOOTSECT_OFFSET	0xC00

#define	uppercase(c)	((c) >= 'a' && (c) <= 'z' ? (c) - 'a' + 'A' : (c))

#define	FAT12_TYPE_STRING	"FAT12   "
#define	FAT16_TYPE_STRING	"FAT16   "
#define	FAT32_TYPE_STRING	"FAT32   "

#define	FAT12_ENTSPERSECT	341
#define	FAT16_ENTSPERSECT	256
#define	FAT32_ENTSPERSECT	128

#ifndef	SUNIXOSBOOT
#define	SUNIXOSBOOT	190	/* Solaris UNIX boot partition */
#endif

/*
 *	MS-DOS Disk layout:
 *
 *	---------------------
 *	|    Boot sector    |
 *	|-------------------|
 *	|   Reserved area   |
 *	|-------------------|
 *	|	FAT #1      |
 *	|-------------------|
 *	|	FAT #2      |
 *	|-------------------|
 *	|   Root directory  |
 *	|-------------------|
 *	|                   |
 *	|     File area     |
 *	|___________________|
 */
#ifdef _LITTLE_ENDIAN
#pragma	pack(1)
#endif
struct _orig_bios_param_blk {
	uint16_t bytes_per_sector;
	uchar_t	 sectors_per_cluster;
	uint16_t resv_sectors;
	uchar_t	 num_fats;
	uint16_t num_root_entries;
/*
 *  The sectors_in_volume field will be zero on larger volumes (>32Mb)
 *  and newer file systems (>=MSDOS4.0).  In these cases the
 *  sectors_in_logical_volume field should be used instead.
 */
	uint16_t sectors_in_volume;
	uchar_t	 media;
	uint16_t sectors_per_fat;
	uint16_t sectors_per_track;
	uint16_t heads;
/*
 *  Number of sectors in the partition prior to the start of the logical disk
 */
	uint32_t hidden_sectors;
	uint32_t sectors_in_logical_volume;
};
#ifdef _LITTLE_ENDIAN
#pragma pack()
#endif

#ifdef _LITTLE_ENDIAN
#pragma	pack(1)
#endif
struct _bpb32_extensions {
	uint32_t big_sectors_per_fat;
	uint16_t ext_flags;
	uchar_t	 fs_vers_lo;
	uchar_t	 fs_vers_hi;
	uint32_t root_dir_clust;
	uint16_t fsinfosec;
	uint16_t backupboot;
	uint16_t reserved[6];
};
#ifdef _LITTLE_ENDIAN
#pragma pack()
#endif

#ifdef _LITTLE_ENDIAN
#pragma	pack(1)
#endif
struct _bpb_extensions {
	uchar_t  phys_drive_num;
	uchar_t  reserved;
	uchar_t  ext_signature;
	uint32_t volume_id;
	uchar_t  volume_label[11];
	uchar_t  type[8];
};
#ifdef _LITTLE_ENDIAN
#pragma pack()
#endif

#ifdef _LITTLE_ENDIAN
#pragma	pack(1)
#endif
struct _sun_bpb_extensions {
	uint16_t  bs_offset_high;
	uint16_t  bs_offset_low;
};
#ifdef _LITTLE_ENDIAN
#pragma pack()
#endif

/*
 * bpb_t is a conglomeration of all the fields a bpb can have.  Every
 * bpb will have the orig_bios struct, but only FAT32's will have bpb32,
 * and only Solaris boot diskettes will have the sunbpb structure.
 */
typedef struct _bios_param_blk {
	struct _orig_bios_param_blk bpb;
	struct _bpb32_extensions    bpb32;
	struct _bpb_extensions	    ebpb;
	struct _sun_bpb_extensions  sunbpb;
} bpb_t;

#ifdef _LITTLE_ENDIAN
#pragma	pack(1)
struct _bpb_head {
	uchar_t			    bs_jump_code[3];
	uchar_t			    bs_oem_name[8];
	struct _orig_bios_param_blk bs_bpb;
};
#pragma pack()

#pragma	pack(1)
struct _boot_sector {
	struct _bpb_head	    bs_front;
	struct _bpb_extensions	    bs_ebpb;
	struct _sun_bpb_extensions  bs_sebpb;
	uchar_t			    bs_bootstrap[444];
	uchar_t			    bs_signature[2];
};
#pragma pack()

#pragma	pack(1)
struct _boot_sector32 {
	struct _bpb_head	    bs_front;
	struct _bpb32_extensions    bs_bpb32;
	struct _bpb_extensions	    bs_ebpb;
	uchar_t			    bs_bootstrap[420];
	uchar_t			    bs_signature[2];
};
#pragma pack()
#else
#define	ORIG_BPB_START_INDEX	8	/* index into filler field */
#define	EXT_BPB_START_INDEX	33	/* index into filler field */
#define	BPB_32_START_INDEX	33	/* index into filler field */
#define	EXT_BPB_32_START_INDEX	61	/* index into filler field */
struct _boot_sector {
	uchar_t	 bs_jump_code[3];
	uchar_t  bs_filler[59];
	uchar_t  bs_sun_bpb[4];
	uchar_t	 bs_bootstrap[444];
	uchar_t  bs_signature[2];
};

struct _boot_sector32 {
	uchar_t	 bs_jump_code[3];
	uchar_t  bs_filler[87];
	uchar_t	 bs_bootstrap[420];
	uchar_t  bs_signature[2];
};
#endif

typedef union _ubso {
	struct _boot_sector	bs;
	struct _boot_sector32	bs32;
	struct mboot		mb;
	uchar_t			buf[MAXBPS];
} boot_sector_t;

#ifdef __cplusplus
}
#endif

#endif /* _PCFS_BPB_H */
/*
 * 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
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2011 Gary Mills
 * Copyright 2024 MNX Cloud, Inc.
 */

/*
 * common functions used by pcfs tools.
 */
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <err.h>
#include <unistd.h>
#include <stdlib.h>
#include <libintl.h>
#include <locale.h>
#include <langinfo.h>
#include <regex.h>
#include <sys/isa_defs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <sys/dktp/fdisk.h>
#include <sys/dkio.h>
#include <sys/fs/pc_fs.h>
#include <sys/fs/pc_dir.h>
#include <sys/fs/pc_label.h>
#include "pcfs_common.h"
#include "pcfs_bpb.h"

/*
 *	The assumption here is that _BIG_ENDIAN implies sparc, and
 *	so in addition to swapping bytes we also have to construct
 *	packed structures by hand to avoid bus errors due to improperly
 *	aligned pointers.
 */
#ifdef _BIG_ENDIAN
void swap_pack_grab32bpb(bpb_t *wbpb, struct _boot_sector *bsp);
void swap_pack_grabbpb(bpb_t *wbpb, struct _boot_sector *bsp);
#endif /* _BIG_ENDIAN */

/*
 * Validate sector size.
 */
bool
is_sector_size_valid(size_t size)
{
	if (size != 512 && size != 1024 && size != 2048 && size != 4096)
		return (false);
	return (true);
}

/*
 * Use DKIOCGMEDIAINFO to get sector size.
 */
int
get_media_sector_size(int fd, size_t *sizep)
{
	struct dk_minfo dkminfo;

	if (ioctl(fd, DKIOCGMEDIAINFO, &dkminfo) != -1) {
		*sizep = dkminfo.dki_lbsize;
		return (0);
	}
	/* In case the DKIOCGMEDIAINFO is not supported, return MINBPS. */
	if (errno == ENOTTY) {
		*sizep = MINBPS;
		return (0);
	}

	return (errno);
}

/*
 * store_16_bits
 *	Save the lower 16 bits of a 32 bit value (v) into the provided
 *	buffer (pointed at by *bp), and increment the buffer pointer
 *	as well.  This way the routine can be called multiple times in
 *	succession to fill buffers.  The value is stored in little-endian
 *	order.
 */
void
store_16_bits(uchar_t **bp, uint32_t v)
{
	uchar_t *l = *bp;

	*l++ = v & 0xff;
	*l = (v >> 8) & 0xff;
	*bp += 2;
}

void
read_16_bits(uchar_t *bp, uint32_t *value)
{
	*value = *bp++;
	*value += *bp << 8;
}

/*
 * store_32_bits
 *	Save the 32 bit value (v) into the provided buffer (pointed
 *	at by *bp), and increment the buffer pointer as well.  This way
 *	the routine can be called multiple times in succession to fill
 *	buffers.  The value is stored in little-endian order.
 */
void
store_32_bits(uchar_t **bp, uint32_t v)
{
	uchar_t *l = *bp;
	int b;

	for (b = 0; b < 4; b++) {
		*l++ = v & 0xff;
		v = v >> 8;
	}
	*bp += 4;
}

void
read_32_bits(uchar_t *bp, uint32_t *value)
{
	*value = *bp++;
	*value += *bp++ << 8;
	*value += *bp++ << 16;
	*value += *bp++ << 24;
}

/*
 *  dump_bytes  -- display bytes as hex numbers.
 *		   b is the pointer to the byte buffer
 *		   n is the number of bytes in the buffer
 */
/* Note: BPL = bytes to display per line */
#define	BPL 16

void
dump_bytes(uchar_t *buf, int n)
{
	int printedCount;
	int countdown = n;
	int countup = 0;
	int offset = 0;
	int byte;

	/* Display offset, 16 bytes per line, and printable ascii version */
	while (countdown > 0) {
		printedCount = 0;
		(void) fprintf(stderr, "\n%06x: ", offset);
		/*
		 * Print Hex value of characters in columns on left
		 */
		for (byte = 0; byte < BPL; byte++) {
			if (countup + byte < n) {
				(void) fprintf(stderr,
				    "%02x ", (buf[countup + byte] & 0xff));
				printedCount++;
			} else {
				(void) fprintf(stderr, "   ");
			}
		}
		/*
		 * Right side has the printable character or '.' for
		 * unprintable for each column of the left.
		 */
		for (byte = 0; byte < BPL; byte++) {
			if ((countup + byte < n) &&
			    ((buf[countup + byte] >= ' ') &&
			    (buf[countup + byte] <= '~'))) {
				(void) fprintf(stderr, "%c",
				    buf[countup + byte]);
			} else {
				(void) fprintf(stderr, ".");
			}
		}
		countup += printedCount;
		offset += printedCount;
		countdown -= printedCount;
	}
	(void) fprintf(stderr, "\n\n");
}

/*
 *  header_for_dump  --  display simple header over what will be output.
 */
void
header_for_dump(void)
{
	int byte;

	(void) fprintf(stderr, "\n        ");
	for (byte = 0; byte < BPL; byte++)
		(void) fprintf(stderr, "%02x ", byte);
	(void) fprintf(stderr, "\n       ");
	byte = 3 * BPL;
	while (byte-- > 0)
		(void) fprintf(stderr, "-");
}

/*
 *  We are basically (incorrectly) assuming that if you aren't running
 *  on x86 the BPB has to be packed by hand AND that the bytes must
 *  be swapped.  One or both of these assumptions may one day be invalid.
 *  (if they aren't already :-))
 */
#ifdef _BIG_ENDIAN
/*
 *  swap_pack_grab{32}bpb
 *	If not on an x86 we assume the structures making up the bpb
 *	were not packed and that longs and shorts need to be byte swapped
 *	(we've kept everything in host order up until now).  A new architecture
 *	might not need to swap or might not need to pack, in which case
 *	new routines will have to be written.  Of course if an architecture
 *	supports both packing and little-endian host order, it can follow the
 *	same path as the x86 code.
 */
void
swap_pack_grabbpb(bpb_t *wbpb, struct _boot_sector *bsp)
{
	uchar_t *grabp;

	grabp = (uchar_t *)&(bsp->bs_filler[ORIG_BPB_START_INDEX]);

	((uchar_t *)&(wbpb->bpb.bytes_per_sector))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.bytes_per_sector))[0] = *grabp++;
	wbpb->bpb.sectors_per_cluster = *grabp++;
	((uchar_t *)&(wbpb->bpb.resv_sectors))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.resv_sectors))[0] = *grabp++;
	wbpb->bpb.num_fats = *grabp++;
	((uchar_t *)&(wbpb->bpb.num_root_entries))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.num_root_entries))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_in_volume))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_in_volume))[0] = *grabp++;
	wbpb->bpb.media = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_per_fat))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_per_fat))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_per_track))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_per_track))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb.heads))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.heads))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb.hidden_sectors))[3] = *grabp++;
	((uchar_t *)&(wbpb->bpb.hidden_sectors))[2] = *grabp++;
	((uchar_t *)&(wbpb->bpb.hidden_sectors))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.hidden_sectors))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_in_logical_volume))[3] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_in_logical_volume))[2] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_in_logical_volume))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb.sectors_in_logical_volume))[0] = *grabp++;
	wbpb->ebpb.phys_drive_num = *grabp++;
	wbpb->ebpb.reserved = *grabp++;
	wbpb->ebpb.ext_signature = *grabp++;
	((uchar_t *)&(wbpb->ebpb.volume_id))[3] = *grabp++;
	((uchar_t *)&(wbpb->ebpb.volume_id))[2] = *grabp++;
	((uchar_t *)&(wbpb->ebpb.volume_id))[1] = *grabp++;
	((uchar_t *)&(wbpb->ebpb.volume_id))[0] = *grabp++;

	(void) strncpy((char *)wbpb->ebpb.volume_label, (char *)grabp, 11);
	grabp += 11;
	(void) strncpy((char *)wbpb->ebpb.type, (char *)grabp, 8);
}

void
swap_pack_grab32bpb(bpb_t *wbpb, struct _boot_sector *bsp)
{
	uchar_t *grabp;

	grabp = (uchar_t *)&(bsp->bs_filler[BPB_32_START_INDEX]);

	((uchar_t *)&(wbpb->bpb32.big_sectors_per_fat))[3] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.big_sectors_per_fat))[2] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.big_sectors_per_fat))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.big_sectors_per_fat))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.ext_flags))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.ext_flags))[0] = *grabp++;
	wbpb->bpb32.fs_vers_lo = *grabp++;
	wbpb->bpb32.fs_vers_hi = *grabp++;
	((uchar_t *)&(wbpb->bpb32.root_dir_clust))[3] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.root_dir_clust))[2] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.root_dir_clust))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.root_dir_clust))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.fsinfosec))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.fsinfosec))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.backupboot))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.backupboot))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[0]))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[0]))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[1]))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[1]))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[2]))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[2]))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[3]))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[3]))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[4]))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[4]))[0] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[5]))[1] = *grabp++;
	((uchar_t *)&(wbpb->bpb32.reserved[5]))[0] = *grabp++;
}
#endif	/* _BIG_ENDIAN */

char *
stat_actual_disk(const char *diskname, struct stat *info, char **suffix)
{
	char *actualdisk;

	if (stat(diskname, info) != 0) {
		/*
		 *  Device named on command line doesn't exist.  That
		 *  probably means there is a partition-specifying
		 *  suffix attached to the actual disk name.
		 */
		if ((actualdisk = strdup(diskname)) == NULL) {
			(void) fprintf(stderr,
			    gettext("Out of memory for disk name.\n"));
			exit(2);
		}
		if ((*suffix = strchr(actualdisk, ':')) != NULL) {
			**suffix = '\0';
			(*suffix)++;
		}

		if (stat(actualdisk, info)) {
			err(2, "Failed to stat disk device %s",
			    actualdisk);
		}
	} else {
		if ((actualdisk = strdup(diskname)) == NULL) {
			(void) fprintf(stderr,
			    gettext("Out of memory for disk name.\n"));
			exit(2);
		}
	}

	return (actualdisk);
}

extern void usage(void);

void
bad_arg(char *option)
{
	(void) fprintf(stderr,
	    gettext("Unrecognized option -o %s.\n"), option);
	usage();
	exit(2);
}

void
missing_arg(char *option)
{
	(void) fprintf(stderr,
	    gettext("Option %s requires a value.\n"), option);
	usage();
	exit(3);
}

static int
parse_drvnum(char *pn)
{
	int drvnum;

	/*
	 * Determine logical drive to seek after.
	 */
	if ((strlen(pn) == 1) && ((*pn >= 'c') && (*pn <= 'z'))) {
		drvnum = *pn - 'c' + 1;
	} else if ((*pn >= '0') && (*pn <= '9')) {
		char *d;
		int v = 0;

		d = pn;
		while ((*d != '\0') && (*d >= '0') && (*d <= '9')) {
			v *= 10;
			v += *d - '0';
			d++;
		}
		if ((*d != '\0') || (v > 24)) {
			(void) fprintf(stderr,
			    gettext("%s: bogus logical drive specification.\n"),
			    pn);
			return (-1);
		}
		drvnum = v;
	} else if (strcmp(pn, "boot") == 0) {
		drvnum = 99;
	} else {
		(void) fprintf(stderr,
		    gettext("%s: bogus logical drive specification.\n"), pn);
		return (-1);
	}

	return (drvnum);
}

/*
 * isDosDrive()
 *	Boolean function.  Give it the systid field for an fdisk partition
 *	and it decides if that's a systid that describes a DOS drive.  We
 *	use systid values defined in sys/dktp/fdisk.h.
 */
static int
isDosDrive(uchar_t checkMe)
{
	return ((checkMe == DOSOS12) || (checkMe == DOSOS16) ||
	    (checkMe == DOSHUGE) || (checkMe == FDISK_WINDOWS) ||
	    (checkMe == FDISK_EXT_WIN) || (checkMe == FDISK_FAT95) ||
	    (checkMe == DIAGPART));
}

/*
 * isDosExtended()
 *	Boolean function.  Give it the systid field for an fdisk partition
 *	and it decides if that's a systid that describes an extended DOS
 *	partition.
 */
static int
isDosExtended(uchar_t checkMe)
{
	return ((checkMe == EXTDOS) || (checkMe == FDISK_EXTLBA));
}

/*
 * isBootPart()
 *	Boolean function.  Give it the systid field for an fdisk partition
 *	and it decides if that's a systid that describes a Solaris boot
 *	partition.
 */
static int
isBootPart(uchar_t checkMe)
{
	return (checkMe == X86BOOT);
}

off64_t
findPartitionOffset(int fd, size_t bpsec, char *ldrive)
{
	struct ipart part[FD_NUMPART];
	struct mboot extmboot;
	struct mboot mb;
	diskaddr_t xstartsect;
	off64_t nextseek = 0;
	off64_t lastseek = 0;
	off64_t found = 0;
	off64_t error = -1;
	int logicalDriveCount = 0;
	int extendedPart = -1;
	int primaryPart = -1;
	int bootPart = -1;
	uint32_t xnumsect = 0;
	int drvnum;
	int driveIndex;
	int i;
	/*
	 * Count of drives in the current extended partition's
	 * FDISK table, and indexes of the drives themselves.
	 */
	int extndDrives[FD_NUMPART];
	int numDrives = 0;
	/*
	 * Count of drives (beyond primary) in master boot record's
	 * FDISK table, and indexes of the drives themselves.
	 */
	int extraDrives[FD_NUMPART];
	int numExtraDrives = 0;

	if ((drvnum = parse_drvnum(ldrive)) < 0)
		return (error);

	if (read(fd, &mb, bpsec) != (ssize_t)bpsec) {
		(void) fprintf(stderr,
		    gettext("Couldn't read a Master Boot Record\n"));
		return (error);
	}

	if (ltohs(mb.signature) != BOOTSECSIG) {
		(void) fprintf(stderr,
		    gettext("Bad signature on master boot record (%x)\n"),
		    ltohs(mb.signature));
		return (error);
	}

	/*
	 * Copy partition table into memory
	 */
	(void) memcpy(part, mb.parts, sizeof (part));

	/*
	 * Get a summary of what is in the Master FDISK table.
	 * Normally we expect to find one partition marked as a DOS drive.
	 * This partition is the one Windows calls the primary dos partition.
	 * If the machine has any logical drives then we also expect
	 * to find a partition marked as an extended DOS partition.
	 *
	 * Sometimes we'll find multiple partitions marked as DOS drives.
	 * The Solaris fdisk program allows these partitions
	 * to be created, but Windows fdisk no longer does.  We still need
	 * to support these, though, since Windows does.  We also need to fix
	 * our fdisk to behave like the Windows version.
	 *
	 * It turns out that some off-the-shelf media have *only* an
	 * Extended partition, so we need to deal with that case as
	 * well.
	 *
	 * Only a single (the first) Extended or Boot Partition will
	 * be recognized.  Any others will be ignored.
	 */
	for (i = 0; i < FD_NUMPART; i++) {
		if (isDosDrive(part[i].systid)) {
			if (primaryPart < 0) {
				logicalDriveCount++;
				primaryPart = i;
			} else {
				extraDrives[numExtraDrives++] = i;
			}
			continue;
		}
		if ((extendedPart < 0) && isDosExtended(part[i].systid)) {
			extendedPart = i;
			continue;
		}
		if ((bootPart < 0) && isBootPart(part[i].systid)) {
			bootPart = i;
			continue;
		}
	}

	if (drvnum == BOOT_PARTITION_DRIVE) {
		if (bootPart < 0) {
			(void) fprintf(stderr,
			    gettext("No boot partition found on drive\n"));
			return (error);
		}
		found = ltohi(part[bootPart].relsect) * bpsec;
		return (found);
	}

	if (drvnum == PRIMARY_DOS_DRIVE && primaryPart >= 0) {
		found = ltohi(part[primaryPart].relsect) * bpsec;
		return (found);
	}

	/*
	 * We are not looking for the C: drive (or there was no primary
	 * drive found), so we had better have an extended partition or
	 * extra drives in the Master FDISK table.
	 */
	if ((extendedPart < 0) && (numExtraDrives == 0)) {
		(void) fprintf(stderr,
		    gettext("No such logical drive "
		    "(missing extended partition entry)\n"));
		return (error);
	}

	if (extendedPart >= 0) {
		nextseek = xstartsect = ltohi(part[extendedPart].relsect);
		xnumsect = ltohi(part[extendedPart].numsect);
		do {
			/*
			 *  If the seek would not cause us to change
			 *  position on the drive, then we're out of
			 *  extended partitions to examine.
			 */
			if (nextseek == lastseek)
				break;
			logicalDriveCount += numDrives;
			/*
			 *  Seek the next extended partition, and find
			 *  logical drives within it.
			 */
			if (lseek64(fd, nextseek * bpsec, SEEK_SET) < 0 ||
			    read(fd, &extmboot, sizeof (extmboot)) !=
			    sizeof (extmboot)) {
				perror(gettext("Unable to read extended "
				    "partition record"));
				return (error);
			}
			(void) memcpy(part, extmboot.parts, sizeof (part));
			lastseek = nextseek;
			if (ltohs(extmboot.signature) != MBB_MAGIC) {
				(void) fprintf(stderr,
				    gettext("Bad signature on "
				    "extended partition\n"));
				return (error);
			}
			/*
			 *  Count up drives, and track where the next
			 *  extended partition is in case we need it.  We
			 *  are expecting only one extended partition.  If
			 *  there is more than one we'll only go to the
			 *  first one we see, but warn about ignoring.
			 */
			numDrives = 0;
			for (i = 0; i < FD_NUMPART; i++) {
				if (isDosDrive(part[i].systid)) {
					extndDrives[numDrives++] = i;
					continue;
				} else if (isDosExtended(part[i].systid)) {
					if (nextseek != lastseek) {
						/*
						 * Already found an extended
						 * partition in this table.
						 */
						(void) fprintf(stderr,
						    gettext("WARNING: "
						    "Ignoring unexpected "
						    "additional extended "
						    "partition"));
						continue;
					}
					nextseek = xstartsect +
					    ltohi(part[i].relsect);
					continue;
				}
			}
		} while (drvnum > logicalDriveCount + numDrives);

		if (drvnum <= logicalDriveCount + numDrives) {
			/*
			 * The number of logical drives we've found thus
			 * far is enough to get us to the one we were
			 * searching for.
			 */
			driveIndex = logicalDriveCount + numDrives - drvnum;
			found =
			    ltohi(part[extndDrives[driveIndex]].relsect) +
			    lastseek;
			if (found > (xstartsect + xnumsect)) {
				(void) fprintf(stderr,
				    gettext("Logical drive start sector (%d) "
				    "is not within the partition!\n"), found);
				return (error);
			} else {
				found *= bpsec;
			}
			return (found);
		} else {
			/*
			 * We ran out of extended dos partition
			 * drives.  The only hope now is to go
			 * back to extra drives defined in the master
			 * fdisk table.  But we overwrote that table
			 * already, so we must load it in again.
			 */
			logicalDriveCount += numDrives;
			(void) memcpy(part, mb.parts, sizeof (part));
		}
	}
	/*
	 *  Still haven't found the drive, is it an extra
	 *  drive defined in the main FDISK table?
	 */
	if (drvnum <= logicalDriveCount + numExtraDrives) {
		driveIndex = logicalDriveCount + numExtraDrives - drvnum;
		found = ltohi(part[extraDrives[driveIndex]].relsect) * bpsec;
		return (found);
	}
	return (error);
}
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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
 */
/*
 * Copyright (c) 1999 by Sun Microsystems, Inc.
 * All rights reserved.
 * Copyright (c) 2011 Gary Mills
 * Copyright 2024 MNX Cloud, Inc.
 */

#ifndef _PCFS_COMMON_H
#define	_PCFS_COMMON_H

/*
 * Common routines for the pcfs user-level utilities
 */

#ifdef __cplusplus
extern "C" {
#endif

#include <stdbool.h>
#include <sys/isa_defs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include "pcfs_bpb.h"

#define	IN_RANGE(n, x, y) (((n) >= (x)) && ((n) <= (y)))

/*
 *  A macro implementing a ceiling function for integer divides.
 */
#define	idivceil(dvend, dvsor) \
	((dvend)/(dvsor) + (((dvend)%(dvsor) == 0) ? 0 : 1))

/*
 * These defines should move into a kernel header file eventually
 * and pcfs_mount may want to refuse to mount FAT32's that aren't "clean"
 *
 *	If Windows shuts down properly it sets the fourth bit of the 8th
 *	and final reserved byte at the start of the FAT.
 */
#define	WIN_SHUTDOWN_STATUS_BYTE	7
#define	WIN_SHUTDOWN_BIT_MASK		0x8

/*
 *  Define some special logical drives we use.
 */
#define	BOOT_PARTITION_DRIVE	99
#define	PRIMARY_DOS_DRIVE	1

/*
 * Function prototypes
 */
extern off64_t findPartitionOffset(int fd, size_t bpsec, char *ldrive);
extern char *stat_actual_disk(const char *diskname, struct stat *info,
	char **suffix);
extern void header_for_dump(void);
extern void store_16_bits(uchar_t **bp, uint32_t v);
extern void store_32_bits(uchar_t **bp, uint32_t v);
extern void read_16_bits(uchar_t *bp, uint32_t *value);
extern void read_32_bits(uchar_t *bp, uint32_t *value);
extern void missing_arg(char *option);
extern void dump_bytes(uchar_t *b, int n);
extern void bad_arg(char *option);
extern void usage(void);
extern bool is_sector_size_valid(size_t size);
extern int  get_media_sector_size(int fd, size_t *sizep);

/*
 *	The assumption here is that _BIG_ENDIAN implies sparc, and
 *	so in addition to swapping bytes we also have to construct
 *	packed structures by hand to avoid bus errors due to improperly
 *	aligned pointers.
 */
#ifdef _BIG_ENDIAN
extern void swap_pack_grab32bpb(bpb_t *wbpb, struct _boot_sector *bsp);
extern void swap_pack_grabbpb(bpb_t *wbpb, struct _boot_sector *bsp);
#endif	/* _BIG_ENDIAN */

#ifdef __cplusplus
}
#endif

#endif /* _PCFS_COMMON_H */