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/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2016 Joyent, Inc.
 * Copyright 2022 MNX Cloud, Inc.
 */

/*
 * Overlay Devices
 *
 * Overlay devices provide a means for creating overlay networks, a means of
 * multiplexing multiple logical, isolated, and discrete layer two and layer
 * three networks on top of one physical network.
 *
 * In general, these overlay devices encapsulate the logic to answer two
 * different questions:
 *
 *   1) How should I transform a packet to put it on the wire?
 *   2) Where should I send a transformed packet?
 *
 * Each overlay device is presented to the user as a GLDv3 device. While the
 * link itself cannot have an IP interface created on top of it, it allows for
 * additional GLDv3 devices, such as a VNIC, to be created on top of it which
 * can be plumbed up with IP interfaces.
 *
 *
 * --------------------
 * General Architecture
 * --------------------
 *
 * The logical overlay device that a user sees in dladm(8) is a combination of
 * two different components that work together. The first component is this
 * kernel module, which is responsible for answering question one -- how should
 * I transform a packet to put it on the wire.
 *
 * The second component is what we call the virtual ARP daemon, or varpd. It is
 * a userland component that is responsible for answering the second question --
 * Where should I send a transformed packet. Instances of the kernel overlay
 * GLDv3 device ask varpd the question of where should a packet go.
 *
 * The split was done for a few reasons. Importantly, we wanted to keep the act
 * of generating encapsulated packets in the kernel so as to ensure that the
 * general data path was fast and also kept simple. On the flip side, while the
 * question of where should something go may be simple, it may often be
 * complicated and need to interface with several different external or
 * distributed systems. In those cases, it's simpler to allow for the full
 * flexibility of userland to be brought to bear to solve that problem and in
 * general, the path isn't very common.
 *
 * The following is what makes up the logical overlay device that a user would
 * create with dladm(8).
 *
 *       Kernel                                     Userland
 *   . . . . . . . . . . . . . . . . . . . . .   . . . . . . . . . . . . .
 *   . +--------+   +--------+  +--------+   .   .                       .
 *   . | VNIC 0 |   | VNIC 1 |  | VNIC 2 |   .   .                       .
 *   . +--------+   +--------+  +--------+   .   .                       .
 *   .     |            |           |        .   .                       .
 *   .     |            |           |        .   .                       .
 *   .     +------------+-----------+        .   .                       .
 *   .                  |              . . /dev/overlay                  .
 *   .           +--------------+      .     .   .       +------------+  .
 *   .           |              |      .     .   .       |            |  .
 *   .           |    Overlay   |======*=================|   Virtual  |  .
 *   .           | GLDv3 Device |========================| ARP Daemon |  .
 *   .           |              |            .   .       |            |  .
 *   .           +--------------+            .   .       +------------+  .
 *   .                  |                    .   .              |        .
 *   .                  |                    .   .              |        .
 *   .           +----------------+          .   .         +--------+    .
 *   .           |  Overlay       |          .   .         | varpd  |    .
 *   .           |  Encapsulation |          .   .         | Lookup |    .
 *   .           |  Plugin        |          .   .         | Plugin |    .
 *   .           +----------------+          .   .         +--------+    .
 *   . . . . . . . . . . . . . . . . . . . . .   . . . . . . . . . . . . .
 *
 *
 * This image shows the two different components and where they live.
 * Importantly, it also shows that both the kernel overlay device and the
 * userland varpd both support plugins. The plugins actually implement the
 * things that users care about and the APIs have been designed to try to
 * minimize the amount of things that a module writer needs to worry about it.
 *
 * IDENTIFIERS
 *
 * Every overlay device is defined by a unique identifier which is the overlay
 * identifier. Its purpose is similar to that of a VLAN identifier, it's a
 * unique number that is used to differentiate between different entries on the
 * wire.
 *
 * ENCAPSULATION
 *
 * An overlay encapsulation plugin is a kernel miscellaneous module whose
 * purpose is to contain knowledge about how to transform packets to put them
 * onto the wire and to take them off. An example of an encapsulation plugin is
 * vxlan. It's also how support for things like nvgre or geneve would be brought
 * into the system.
 *
 * Each encapsulation plugins defines a series of operation vectors and
 * properties. For the full details on everything they should provide, please
 * read uts/common/sys/overlay_plugin.h. The encapsulation plugin is responsible
 * for telling the system what information is required to send a packet. For
 * example, vxlan is defined to send everything over a UDP packet and therefore
 * requires a port and an IP address, while nvgre on the other hand is its own
 * IP type and therefore just requires an IP address. In addition, it also
 * provides information about the kind of socket that should be created. This is
 * used by the kernel multiplexor, more of that in the Kernel Components
 * section.
 *
 * LOOKUPS
 *
 * The kernel communicates requests for lookups over the character device
 * /dev/overlay. varpd is responsible for listening for requests on that device
 * and answering them. The character device is specific to the target path and
 * varpd.
 *
 * Much as the kernel overlay module handles the bulk of the scaffolding but
 * leaves the important work to the encapsulation plugin, varpd provides a
 * similar role and leaves the full brunt of lookups to a userland dynamic
 * shared object which implements the logic of lookups.
 *
 * Each lookup plugin defines a series of operation vectors and properties. For
 * the full details on everything that they should provide, please read
 * lib/varpd/libvarpd/libvarpd_provider.h. Essentially, they are given a MAC
 * address and asked to give an address on the physical network that it should
 * be sent to. In addition, they handle questions related to how to handle
 * things like broadcast and multicast traffic, etc.
 *
 * ----------
 * Properties
 * ----------
 *
 * A device from a dladm perspective has a unique set of properties that are
 * combined from three different sources:
 *
 *   1) Generic properties that every overlay device has
 *   2) Properties that are specific to the encapsulation plugin
 *   3) Properties that are specific to the lookup plugin
 *
 * All of these are exposed in a single set of properties in dladm. Note that
 * these are not necessarily traditional link properties. However, if something
 * is both a traditional GLDv3 link property, say the MTU of a device, and a
 * specific property here, than the driver ensures that all existing GLDv3
 * specific means of manipulating it are used and wraps up its private property
 * interfaces to ensure that works.
 *
 * Properties in the second and third category are prefixed with the name of
 * their module. For example, the vxlan encapsulation module has a property
 * called the 'listen_ip'. This property would show up in dladm as
 * 'vxlan/listen_ip'. This allows different plugins to both use similar names
 * for similar properties and to also have independent name spaces so that
 * overlapping names do not conflict with anything else.
 *
 * While the kernel combines both sets one and two into a single coherent view,
 * it does not do anything with respect to the properties that are owned by the
 * lookup plugin -- those are owned wholly by varpd. Instead, libdladm is in
 * charge of bridging these two worlds into one magical experience for the user.
 * It carries the burden of knowing about both overlay specific and varpd
 * specific properties. Importantly, we want to maintain this distinction. We
 * don't want to treat the kernel as an arbitrary key/value store for varpd and
 * we want the kernel to own its own data and not have to ask userland for
 * information that it owns.
 *
 * Every property in the system has the following attributes:
 *
 *   o A name
 *   o A type
 *   o A size
 *   o Permissions
 *   o Default value
 *   o Valid value ranges
 *   o A value
 *
 * Everything except for the value is obtained by callers through the propinfo
 * callbacks and a property has a maximum size of OVERLAY_PROP_SIZEMAX,
 * currently 256 bytes.
 *
 * The following are the supported types of properties:
 *
 *	OVERLAY_PROP_T_INT
 *
 *		A signed integer, its length is 8 bytes, corresponding to a
 *		int64_t.
 *
 *	OVERLAY_PROP_T_UINT
 *
 *		An unsigned integer, its length is 8 bytes, corresponding to a
 *		uint64_t.
 *
 *	OVERLAY_PROP_T_IP
 *
 *		A struct in6_addr, it has a fixed size.
 *
 *	OVERLAY_PROP_T_STRING
 *
 *		A null-terminated character string encoded in either ASCII or
 *		UTF-8. Note that the size of the string includes the null
 *		terminator.
 *
 * The next thing that we apply to a property is its permission. The permissions
 * are put together by the bitwise or of the following flags and values.
 *
 *	OVERLAY_PROP_PERM_REQ
 *
 *		This indicates a required property. A property that is required
 *		must be set by a consumer before the device can be created. If a
 *		required property has a default property, this constraint is
 *		loosened because the default property defines the value.
 *
 *	OVERLAY_PORP_PERM_READ
 *
 *		This indicates that a property can be read. All properties will
 *		have this value set.
 *
 *	OVERLAY_PROP_PERM_WRITE
 *
 *		This indicates that a property can be written to and thus
 *		updated by userland. Properties that are only intended to
 *		display information, will not have OVERLAY_PROP_PERM_WRITE set.
 *
 * In addition, a few additional values are defined as a convenience to
 * consumers. The first, OVERLAY_PROP_PERM_RW, is a combination of
 * OVERLAY_PROP_PERM_READ and OVERLAY_PERM_PROP_WRITE. The second,
 * OVERLAY_PROP_PERM_RRW, is a combination of OVERLAY_PROP_PERM_REQ,
 * OVERLAY_PROP_PERM_READ, and OVERLAY_PROP_PERM_WRITE. The protection mode of a
 * property should generally be a constant across its lifetime.
 *
 * A property may optionally have a default value. If it does have a default
 * value, and that property is not set to be a different value, then the default
 * value is inherited automatically. It also means that if the default value is
 * acceptable, there is no need to set the value for a required property. For
 * example, the vxlan module has the vxlan/listen_port property which is
 * required, but has a default value of 4789 (the IANA assigned port). Because
 * of that default value, there is no need for it to be set.
 *
 * Finally, a property may declare a list of valid values. These valid values
 * are used for display purposes, they are not enforced by the broader system,
 * but merely allow a means for the information to be communicated to the user
 * through dladm(8). Like a default value, this is optional.
 *
 * The general scaffolding does not do very much with respect to the getting and
 * setting of properties. That is really owned by the individual plugins
 * themselves.
 *
 * -----------------------------
 * Destinations and Plugin Types
 * -----------------------------
 *
 * Both encapsulation and lookup plugins define the kinds of destinations that
 * they know how to support. There are three different pieces of information
 * that can be used to address to a destination currently, all of which is
 * summarized in the type overlay_point_t. Any combination of these is
 * supported.
 *
 *	OVERLAY_PLUGIN_D_ETHERNET
 *
 *		An Ethernet MAC address is required.
 *
 *	OVERLAY_PLUGIN_D_IP
 *
 *		An IP address is required. All IP addresses used by the overlay
 *		system are transmitted as IPv6 addresses. IPv4 addresses can be
 *		represented by using IPv4-mapped IPv6 addresses.
 *
 *	OVERLAY_PLUGIN_D_PORT
 *
 *		A TCP/UDP port is required.
 *
 * A kernel encapsulation plugin declares which of these that it requires, it's
 * a static set. On the other hand, a userland lookup plugin can be built to
 * support all of these or any combination thereof. It gets passed the required
 * destination type, based on the kernel encapsulation method, and then it makes
 * the determination as to whether or not it supports it. For example, the
 * direct plugin can support either an IP or both an IP and a port, it simply
 * doesn't display the direct/dest_port property in the cases where a port is
 * not required to support this.
 *
 * The user lookup plugins have two different modes of operation which
 * determines how they interact with the broader system and how look ups are
 * performed. These types are:
 *
 *	OVERLAY_TARGET_POINT
 *
 *		A point to point plugin has a single static definition for where
 *		to send all traffic. Every packet in the system always gets sent
 *		to the exact same destination which is programmed into the
 *		kernel when the general device is activated.
 *
 *	OVERLAY_TARGET_DYNAMIC
 *
 *		A dynamic plugin does not have a single static definition.
 *		Instead, for each destination, the kernel makes an asynchronous
 *		request to varpd to determine where the packet should be routed,
 *		and if a specific destination is found, then that destination is
 *		cached in the overlay device's target cache.
 *
 * This distinction, while important for the general overlay device's operation,
 * is not important to the encapsulation plugins. They don't need to know about
 * any of these pieces. It's just a concern for varpd, the userland plugin, and
 * the general overlay scaffolding.
 *
 * When an overlay device is set to OVERLAY_TARGET_POINT, then it does not
 * maintain a target cache, and instead just keeps track of the destination and
 * always sends encapsulated packets to that address. When the target type is of
 * OVERLAY_TARGET_DYNAMIC, then the kernel maintains a cache of all such
 * destinations. These destinations are kept around in an instance of a
 * reference hash that is specific to the given overlay device. Entries in the
 * cache can be invalidated and replaced by varpd and its lookup plugins.
 *
 * ----------------------------------
 * Kernel Components and Architecture
 * ----------------------------------
 *
 * There are multiple pieces inside the kernel that work together, there is the
 * general overlay_dev_t structure, which is the logical GLDv3 device, but it
 * itself has references to things like an instance of an encapsulation plugin,
 * a pointer to a mux and a target cache. It can roughly be summarized in the
 * following image:
 *
 *     +------------------+
 *     | global           |
 *     | overlay list     |
 *     | overlay_dev_list |
 *     +------------------+
 *        |
 *        |  +-----------------------+            +---------------+
 *        +->| GLDv3 Device          |----------->| GLDv3 Device  | -> ...
 *           | overlay_dev_t         |            | overlay_dev_t |
 *           |                       |            +---------------+
 *           |                       |
 *           | mac_handle_t     -----+---> GLDv3 handle to MAC
 *           | datalink_id_t    -----+---> Datalink ID used by DLS
 *           | overlay_dev_flag_t ---+---> Device state
 *           | uint_t           -----+---> Current device MTU
 *           | uint_t           -----+---> In-progress RX operations
 *           | uint_t           -----+---> In-progress TX operations
 *           | char[]           -----+---> FMA degraded message
 *           | void *           -----+---> plugin private data
 *           | overlay_target_t * ---+---------------------+
 *           | overlay_plugin_t * ---+---------+           |
 *           +-----------------------+         |           |
 *                           ^                 |           |
 *   +--------------------+  |                 |           |
 *   | Kernel Socket      |  |                 |           |
 *   | Multiplexor        |  |                 |           |
 *   | overlay_mux_t      |  |                 |           |
 *   |                    |  |                 |           |
 *   | avl_tree_t        -+--+                 |           |
 *   | uint_t            -+--> socket family   |           |
 *   | uint_t            -+--> socket type     |           |
 *   | uint_t            -+--> socket protocol |           |
 *   | ksocket_t         -+--> I/O socket      |           |
 *   | struct sockaddr * -+--> ksocket address |           |
 *   | overlay_plugin_t --+--------+           |           |
 *   +--------------------+        |           |           |
 *                                 |           |           |
 *   +-------------------------+   |           |           |
 *   | Encap Plugin            |<--+-----------+           |
 *   | overlay_plugin_t        |                           |
 *   |                         |                           |
 *   | char *               ---+--> plugin name            |
 *   | overlay_plugin_ops_t * -+--> plugin downcalls       |
 *   | char ** (props)      ---+--> property list          |
 *   | uint_t               ---+--> id length              |
 *   | overlay_plugin_flags_t -+--> plugin flags           |
 *   | overlay_plugin_dest_t --+--> destination type       v
 *   +-------------------------+                    +-------------------------+
 *                                                  |   Target Cache          |
 *                                                  |   overlay_target_t      |
 *                                                  |                         |
 *                                    cache mode <--+- overlay_target_mode_t  |
 *                                     dest type <--+- overlay_plugin_dest_t  |
 *                                   cache flags <--+- overlay_target_flag_t  |
 *                                     varpd id  <--+- uint64_t               |
 *                       outstanding varpd reqs. <--+- uint_t                 |
 *                   OVERLAY_TARGET_POINT state  <--+- overlay_target_point_t |
 *               OVERLAY_TARGET_DYNAMIC state <-+---+- overlay_target_dyn_t   |
 *                                              |   +-------------------------+
 *                      +-----------------------+
 *                      |
 *                      v
 *   +-------------------------------+   +------------------------+
 *   | Target Entry                  |-->| Target Entry           |--> ...
 *   | overlay_target_entry_t        |   | overlay_target_entry_t |
 *   |                               |   +------------------------+
 *   |                               |
 *   | overlay_target_entry_flags_t -+--> Entry flags
 *   | uint8_t[ETHERADDRL]        ---+--> Target MAC address
 *   | overlay_target_point_t     ---+--> Target underlay address
 *   | mblk_t *                   ---+--> outstanding mblk head
 *   | mblk_t *                   ---+--> outstanding mblk tail
 *   | size_t                     ---+--> outstanding mblk size
 *   +-------------------------------+
 *
 * The primary entries that we care about are the overlay_dev_t, which
 * correspond to each overlay device that is created with dladm(8). Globally,
 * these devices are maintained in a simple list_t which is protected with a
 * lock.  Hence, these include important information such as the mac_handle_t
 * and a datalink_id_t which is used to interact with the broader MAC and DLS
 * ecosystem. We also maintain additional information such as the current state,
 * outstanding operations, the mtu, and importantly, the plugin's private data.
 * This is the instance of an encapsulation plugin that gets created as part of
 * creating an overlay device. Another aspect of this is that the overlay_dev_t
 * also includes information with respect to FMA. For more information, see the
 * FMA section.
 *
 * Each overlay_dev_t has a pointer to a plugin, a mux, and a target. The plugin
 * is the encapsulation plugin. This allows the device to make downcalls into it
 * based on doing things like getting and setting properties. Otherwise, the
 * plugin itself is a fairly straightforward entity. They are maintained in an
 * (not pictured above) list. The plugins themselves mostly maintain things like
 * the static list of properties, what kind of destination they require, and the
 * operations vector. A given module may contain more if necessary.
 *
 * The next piece of the puzzle is the mux, or a multiplexor. The mux itself
 * maintains a ksocket and it is through the mux that we send and receive
 * message blocks. The mux represents a socket type and address, as well as a
 * plugin. Multiple overlay_dev_t devices may then share the same mux. For
 * example, consider the case where you have different instances of vxlan all on
 * the same underlay network. These would all logically share the same IP
 * address and port that packets are sent and received on; however, what differs
 * is the decapuslation ID.
 *
 * Each mux maintains a ksocket_t which is similar to a socket(3SOCKET). Unlike
 * a socket, we enable a direct callback on the ksocket. This means that
 * whenever a message block chain is received, rather than sitting there and
 * getting a callback in a context and kicking that back out to a taskq. Instead
 * data comes into the callback function overlay_mux_recv().
 *
 * The mux is given encapsulated packets (via overlay_m_tx, the GLDv3 tx
 * function) to transmit. It receives encapsulated packets, decapsulates them to
 * determine the overlay identifier, looks up the given device that matches that
 * identifier, and then causes the broader MAC world to receive the packet with
 * a call to mac_rx().
 *
 * Today, we don't do too much that's special with the ksocket; however, as
 * hardware is gaining understanding for these encapsulation protocols, we'll
 * probably want to think of better ways to get those capabilities passed down
 * and potentially better ways to program receive filters so they get directly
 * to us. Though, that's all fantasy future land.
 *
 * The next part of the puzzle is the target cache. The purpose of the target
 * cache is to cache where we should send a packet on the underlay network,
 * given its mac address. The target cache operates in two modes depending on
 * whether the lookup module was declared to OVERLAY_TARGET_POINT or
 * OVERLAY_TARGET_DYANMIC.
 *
 * In the case where the target cache has been programmed to be
 * OVERLAY_TARGET_POINT, then we only maintain a single overlay_target_point_t
 * which has the destination that we send everything, no matter the destination
 * mac address.
 *
 * On the other hand, when we have an instance of OVERLAY_TARGET_DYNAMIC, things
 * are much more interesting and as a result, more complicated. We primarily
 * store lists of overlay_target_entry_t's which are stored in both an avl tree
 * and a refhash_t. The primary look up path uses the refhash_t and the avl tree
 * is only used for a few of the target ioctls used to dump data such that we
 * can get a consistent iteration order for things like dladm show-overlay -t.
 * The key that we use for the reference hashtable is based on the mac address
 * in the cache and currently we just do a simple CRC32 to transform it into a
 * hash.
 *
 * Each entry maintains a set of flags to indicate the current status of the
 * request. The flags may indicate one of three states: that current cache entry
 * is valid, that the current cache entry has been directed to drop all output,
 * and that the current cache entry is invalid and may be being looked up. In
 * the case where it's valid, we just take the destination address and run with
 * it.
 *
 * If it's invalid and a lookup has not been made, then we start the process
 * that prepares a query that will make its way up to varpd. The cache entry
 * entry maintains a message block chain of outstanding message blocks and a
 * size. These lists are populated only when we don't know the answer as to
 * where should these be sent. The size entry is used to cap the amount of
 * outstanding data that we don't know the answer to. If we exceed a cap on the
 * amount of outstanding data (currently 1 Mb), then we'll drop any additional
 * packets. Once we get an answer indicating a valid destination, we transmit
 * any outstanding data to that place. For the full story on how we look that up
 * will be discussed in the section on the Target Cache Lifecycle.
 *
 * ------------------------
 * FMA and Degraded Devices
 * ------------------------
 *
 * Every kernel overlay device keeps track of its FMA state. Today in FMA we
 * cannot represent partitions between resources nor can we represent that a
 * given minor node of a pseudo device has failed -- if we degrade the overlay
 * device, then the entire dev_info_t is degraded. However, we still want to be
 * able to indicate to administrators that things may go wrong.
 *
 * To this end, we've added a notion of a degraded state to every overlay
 * device. This state is primarily dictated by userland and it can happen for
 * various reasons. Generally, because a userland lookup plugin has been
 * partitioned, or something has gone wrong such that there is no longer any
 * userland lookup module for a device, then we'll mark it degraded.
 *
 * As long as any of our minor instances is degraded, then we'll fire off the
 * FMA event to note that. Once the last degraded instance is no longer
 * degraded, then we'll end up telling FMA that we're all clean.
 *
 * To help administrators get a better sense of which of the various minor
 * devices is wrong, we store the odd_fmamsg[] character array. This character
 * array can be fetched with doing a dladm show-overlay -f.
 *
 * Note, that it's important that we do not update the link status of the
 * devices. We want to remain up as much as possible. By changing the link in a
 * degraded state, this may end up making things worse. We may still actually
 * have information in the target cache and if we mark the link down, that'll
 * result in not being able to use it. The reason being that this'll mark all
 * the downstream VNICs down which will go to IP and from there we end up
 * dealing with sadness.
 *
 * -----------------------
 * Target Cache Life Cycle
 * -----------------------
 *
 * This section only applies when we have a lookup plugin of
 * OVERLAY_TARGET_DYNAMIC. None of this applies to those of type
 * OVERLAY_TARGET_POINT.
 *
 * While we got into the target cache in the general architecture section, it's
 * worth going into more details as to how this actually works and showing some
 * examples and state machines. Recall that a target cache entry basically has
 * the following state transition diagram:
 *
 * Initial state
 *    . . .           . . . first access       . . . varpd lookup enqueued
 *        .           .                        .
 *        .           .                        .
 *     +-------+      .     +----------+       .
 *     |  No   |------*---->| Invalid  |-------*----+
 *     | Entry |            |  Entry   |            |
 *     +-------+            +----------+            |
 *                 varpd      ^      ^   varpd      |
 *                 invalidate |      |   drop       |
 *                      . . . *      * . .          v
 *          +-------+         |      |         +---------+
 *          | Entry |--->-----+      +----<----| Entry   |
 *          | Valid |<----------*---------<----| Pending |->-+     varpd
 *          +-------+           .              +---------+   * . . drop, but
 *                              . varpd                ^     |     other queued
 *                              . success              |     |     entries
 *                                                     +-----+
 *
 * When the table is first created, it is empty. As we attempt to lookup entries
 * and we find there is no entry at all, we'll create a new table entry for it.
 * At that point the entry is technically in an invalid state, that means that
 * we have no valid data from varpd. In that case, we'll go ahead and queue the
 * packet into the entry's pending chain, and queue a varpd lookup, setting the
 * OVERLAY_ENTRY_F_PENDING flag in the progress.
 *
 * If additional mblk_t's come in for this entry, we end up appending them to
 * the tail of the chain, if and only if, we don't exceed the threshold for the
 * amount of space they can take up. An entry remains pending until we get a
 * varpd reply. If varpd replies with a valid results, we move to the valid
 * entry state, and remove the OVERLAY_ENTRY_F_PENDING flag and set it with one
 * of OVERLAY_ENTRY_F_VALID or OVERLAY_ENTRY_F_DROP as appropriate.
 *
 * Once an entry is valid, it stays valid until user land tells us to invalidate
 * it with an ioctl or replace it, OVERLAY_TARG_CACHE_REMOE and
 * OVERLAY_TARG_CACHE_SET respectively.
 *
 * If the lookup fails with a call to drop the packet, then the next state is
 * determined by the state of the queue. If the set of outstanding entries is
 * empty, then we just transition back to the invalid state. If instead, the
 * set of outstanding entries is not empty, then we'll queue another entry and
 * stay in the same state, repeating this until the number of requests is
 * drained.
 *
 * The following images describes the flow of a given lookup and where the
 * overlay_target_entry_t is at any given time.
 *
 *     +-------------------+
 *     | Invalid Entry     |		An entry starts off as an invalid entry
 *     | de:ad:be:ef:00:00 |		and only exists in the target cache.
 *     +-------------------+
 *
 *	~~~~
 *
 *     +---------------------+
 *     | Global list_t       |		A mblk_t comes in for an entry. We
 *     | overlay_target_list |		append it to the overlay_target_list.
 *     +---------------------+
 *                   |
 *                   v
 *             +-------------------+      +-------------------+
 *             | Pending Entry     |----->| Pending Entry     |--->...
 *             | 42:5e:1a:10:d6:2d |      | de:ad:be:ef:00:00 |
 *             +-------------------+      +-------------------+
 *
 *	~~~~
 *
 *     +--------------------------+
 *     | /dev/overlay minor state |	User land said that it would look up an
 *     | overlay_target_hdl_t     |	entry for us. We remove it from the
 *     +--------------------------+	global list and add it to the handle's
 *                  |			outstanding list.
 *                  |
 *                  v
 *            +-------------------+      +-------------------+
 *            | Pending Entry     |----->| Pending Entry     |
 *            | 90:b8:d0:79:02:dd |      | de:ad:be:ef:00:00 |
 *            +-------------------+      +-------------------+
 *
 *	~~~~
 *
 *     +-------------------+
 *     | Valid Entry       |		varpd returned an answer with
 *     | de:ad:be:ef:00:00 |		OVERLAY_IOC_RESPOND and the target cache
 *     | 10.169.23.42:4789 |		entry is now populated with a
 *     +-------------------+		destination and marked as valid
 *
 *
 * The lookup mechanism is performed via a series of operations on the character
 * pseudo-device /dev/overlay. The only thing that uses this device is the
 * userland daemon varpd. /dev/overlay is a cloneable device, each open of it
 * granting a new minor number which maintains its own state. We maintain this
 * state so that way if an outstanding lookup was queued to something that
 * crashed or closed its handle without responding, we can know about this and
 * thus handle it appropriately.
 *
 * When a lookup is first created it's added to our global list of outstanding
 * lookups. To service requests, userland is required to perform an ioctl to ask
 * for a request. We will block it in the kernel a set amount of time waiting
 * for a request. When we give a request to a given minor instance of the
 * device, we remove it from the global list and append the request to the
 * device's list of outstanding entries, for the reasons we discussed above.
 * When a lookup comes in, we give user land a smaller amount of information
 * specific to that packet, the overlay_targ_lookup_t. It includes a request id
 * to identify this, and then the overlay id, the varpd id, the header and
 * packet size, the source and destination mac address, the SAP, and any
 * potential VLAN header.
 *
 * At that point, it stays in that outstanding list until one of two ioctls are
 * returned: OVERLAY_TARG_RESPOND or OVERLAY_TARG_DROP. During this time,
 * userland may also perform other operations. For example, it may use
 * OVERLAY_TARG_PKT to get a copy of this packet so it can perform more in-depth
 * analysis of what to do beyond what we gave it initially. This is useful for
 * providing proxy arp and the like. Finally, there are two other ioctls that
 * varpd can then do. The first is OVERLAY_TARG_INJECT which injects the
 * non-jumbo frame packet up into that mac device and OVERLAY_TARG_RESEND which
 * causes us to encapsulate and send out the packet they've given us.
 *
 *
 * Finally, through the target cache, several ioctls are provided to allow for
 * interrogation and management of the cache. They allow for individual entries
 * to be retrieved, set, or have the entire table flushed. For the full set of
 * ioctls here and what they do, take a look at uts/common/sys/overlay_target.h.
 *
 * ------------------
 * Sample Packet Flow
 * ------------------
 *
 * There's a lot of pieces here, hopefully an example of how this all fits
 * together will help clarify and elucidate what's going on. We're going to
 * first track an outgoing packet, eg. one that is sent from an IP interface on
 * a VNIC on top of an overlay device, and then we'll look at what it means to
 * respond to that.
 *
 *
 *    +----------------+        +--------------+            +------------------+
 *    | IP/DLS send    |------->| MAC sends it |----------->| mblk_t reaches   |
 *    | packet to MAC  |        | to the GLDv3 |            | overlay GLDv3 tx |
 *    +----------------+        | VNIC device  |            | overlay_m_tx()   |
 *                              +--------------+            +------------------+
 *                                                                   |
 *                             . lookup              . cache         |
 *                             . drop                . miss          v
 *            +---------+      .       +--------+    .      +------------------+
 *            | freemsg |<-----*-------| varpd  |<---*------| Lookup each mblk |
 *            | mblk_t  |              | lookup |           | in the target    |
 *            +---------+              | queued |           | cache            |
 *                ^                    +--------+           +------------------+
 *      on send   |                        |                         |     cache
 *      error . . *                        *. . lookup               * . . hit
 *                |                        |    success              v
 *                |                        |                +------------------+
 *    +-----------------+                  +--------------->| call plugin      |
 *    | Send out        |                                   | ovpo_encap() to  |
 *    | overlay_mux_t's |<----------------------------------| get encap mblk_t |
 *    | ksocket         |                                   +------------------+
 *    +-----------------+
 *
 * The receive end point looks a little different and looks more like:
 *
 *  +------------------+     +----------------+    +-----------+
 *  | mblk_t comes off |---->| enter netstack |--->| delivered |---+
 *  | the physical     |     | IP stack       |    |     to    |   * . . direct
 *  | device           |     +----------------+    |  ksocket  |   |   callback
 *  +------------------+                           +-----------+   |
 *                       . overlay id                              |
 *                       . not found                               v
 *       +-----------+   .      +-----------------+       +--------------------+
 *       | freemsg   |<--*------| call plugin     |<------| overlay_mux_recv() |
 *       | mblk_t    |          | ovpo_decap() to |       +--------------------+
 *       +-----------+          | decap mblk_t    |
 *                              +-----------------+
 *                                     |
 *                                     * . . overlay id
 *                                     v     found
 *                                 +--------+      +----------------+
 *                                 | adjust |----->| call mac_rx    |
 *                                 | mblk_t |      | on original    |
 *                                 +--------+      | decaped packet |
 *                                                 +----------------+
 *
 * ------------------
 * Netstack Awareness
 * ------------------
 *
 * In the above image we note that this enters a netstack. Today the only
 * netstack that can be is the global zone as the overlay driver itself is not
 * exactly netstack aware. What this really means is that varpd cannot run in a
 * non-global zone and an overlay device cannot belong to a non-global zone.
 * Non-global zones can still have a VNIC assigned to them that's been created
 * over the overlay device the same way they would if it had been created over
 * an etherstub or a physical device.
 *
 * The majority of the work to make it netstack aware is straightforward and the
 * biggest thing is to create a netstack module that allows us to hook into
 * netstack (and thus zone) creation and destruction.  From there, we need to
 * amend the target cache lookup routines that we discussed earlier to not have
 * a global outstanding list and a global list of handles, but rather, one per
 * netstack.
 *
 * For the mux, we'll need to open the ksocket in the context of the zone, we
 * can likely do this with a properly composed credential, but we'll need to do
 * some more work on that path. Finally, we'll want to make sure the dld ioctls
 * are aware of the zoneid of the caller and we use that appropriately and store
 * it in the overlay_dev_t.
 *
 * -----------
 * GLDv3 Notes
 * -----------
 *
 * The overlay driver implements a GLDv3 device. Parts of GLDv3 are more
 * relevant and other parts are much less relevant for us. For example, the
 * GLDv3 is used to toggle the device being put into and out of promiscuous
 * mode, to program MAC addresses for unicast and multicast hardware filters.
 * Today, an overlay device doesn't have a notion of promiscuous mode nor does
 * it have a notion of unicast and multicast addresses programmed into the
 * device. Instead, for the purposes of the hardware filter, we don't do
 * anything and just always accept new addresses being added and removed.
 *
 * If the GLDv3 start function has not been called, then we will not use this
 * device for I/O purposes. Any calls to transmit or receive should be dropped,
 * though the GLDv3 guarantees us that transmit will not be called without
 * calling start. Similarly, once stop is called, then no packets can be dealt
 * with.
 *
 * Today we don't support the stat interfaces, though there's no good reason
 * that we shouldn't assemble some of the stats based on what we have in the
 * future.
 *
 * When it comes to link properties, many of the traditional link properties do
 * not apply and many others MAC handles for us. For example, we don't need to
 * implement anything for overlay_m_getprop() to deal with returning the MTU, as
 * MAC never calls into us for that. As such, there isn't much of anything to
 * support in terms of properties.
 *
 * Today, we don't support any notion of hardware capabilities. However, if
 * future NIC hardware or other changes to the system cause it to make sense for
 * us to emulate logical groups, then we should do that. However, we still do
 * implement a capab function so that we can identify ourselves as an overlay
 * device to the broader MAC framework. This is done mostly so that a device
 * created on top of us can have fanout rings as we don't try to lie about a
 * speed for our device.
 *
 * The other question is what should be done for a device's MTU and margin. We
 * set our minimum supported MTU to be the minimum value that an IP network may
 * be set to 576 -- which mimics what an etherstub does. On the flip side, we
 * have our upper bound set to 8900. This value comes from the fact that a lot
 * of jumbo networks use their maximum as 9000. As such, we want to reserve 100
 * bytes, which isn't exactly the most accurate number, but it'll be good enough
 * for now. Because of that, our default MTU off of these devices is 1400, as
 * the default MTU for everything is usually 1500 or whatever the underlying
 * device is at; however, this is a bit simpler than asking the netstack what
 * are all the IP interfaces at. It also calls into question how PMTU and PMTU
 * discovery should work here. The challenge, especially for
 * OVERLAY_TARG_DYNAMIC is that the MTU to any of the places will vary and it's
 * not clear that if you have a single bad entry that the overall MTU should be
 * lowered. Instead, we should figure out a better way of determining these
 * kinds of PMTU errors and appropriately alerting the administrator via FMA.
 *
 * Regarding margin, we allow a margin of up to VLAN_TAGSZ depending on whether
 * or not the underlying encapsulation device supports VLAN tags. If it does,
 * then we'll set the margin to allow for it, otherwise, we will not.
 */

#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/modctl.h>
#include <sys/policy.h>
#include <sys/stream.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/types.h>
#include <sys/kmem.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/ddifm.h>

#include <sys/dls.h>
#include <sys/dld_ioc.h>
#include <sys/mac_provider.h>
#include <sys/mac_client_priv.h>
#include <sys/mac_ether.h>
#include <sys/vlan.h>

#include <sys/overlay_impl.h>

dev_info_t *overlay_dip;
static kmutex_t overlay_dev_lock;
static list_t overlay_dev_list;
static uint8_t overlay_macaddr[ETHERADDRL] =
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

typedef enum overlay_dev_prop {
	OVERLAY_DEV_P_MTU = 0,
	OVERLAY_DEV_P_VNETID,
	OVERLAY_DEV_P_ENCAP,
	OVERLAY_DEV_P_VARPDID
} overlay_dev_prop_t;

#define	OVERLAY_DEV_NPROPS	4
static const char *overlay_dev_props[] = {
	"mtu",
	"vnetid",
	"encap",
	"varpd/id"
};

#define	OVERLAY_MTU_MIN	576
#define	OVERLAY_MTU_DEF	1400
#define	OVERLAY_MTU_MAX	8900

overlay_dev_t *
overlay_hold_by_dlid(datalink_id_t id)
{
	overlay_dev_t *o;

	mutex_enter(&overlay_dev_lock);
	for (o = list_head(&overlay_dev_list); o != NULL;
	    o = list_next(&overlay_dev_list, o)) {
		if (id == o->odd_linkid) {
			mutex_enter(&o->odd_lock);
			o->odd_ref++;
			mutex_exit(&o->odd_lock);
			mutex_exit(&overlay_dev_lock);
			return (o);
		}
	}

	mutex_exit(&overlay_dev_lock);
	return (NULL);
}

void
overlay_hold_rele(overlay_dev_t *odd)
{
	mutex_enter(&odd->odd_lock);
	ASSERT(odd->odd_ref > 0);
	odd->odd_ref--;
	mutex_exit(&odd->odd_lock);
}

void
overlay_io_start(overlay_dev_t *odd, overlay_dev_flag_t flag)
{
	ASSERT(flag == OVERLAY_F_IN_RX || flag == OVERLAY_F_IN_TX);
	ASSERT(MUTEX_HELD(&odd->odd_lock));

	if (flag & OVERLAY_F_IN_RX)
		odd->odd_rxcount++;
	if (flag & OVERLAY_F_IN_TX)
		odd->odd_txcount++;
	odd->odd_flags |= flag;
}

void
overlay_io_done(overlay_dev_t *odd, overlay_dev_flag_t flag)
{
	boolean_t signal = B_FALSE;

	ASSERT(flag == OVERLAY_F_IN_RX || flag == OVERLAY_F_IN_TX);
	ASSERT(MUTEX_HELD(&odd->odd_lock));

	if (flag & OVERLAY_F_IN_RX) {
		ASSERT(odd->odd_rxcount > 0);
		odd->odd_rxcount--;
		if (odd->odd_rxcount == 0) {
			signal = B_TRUE;
			odd->odd_flags &= ~OVERLAY_F_IN_RX;
		}
	}
	if (flag & OVERLAY_F_IN_TX) {
		ASSERT(odd->odd_txcount > 0);
		odd->odd_txcount--;
		if (odd->odd_txcount == 0) {
			signal = B_TRUE;
			odd->odd_flags &= ~OVERLAY_F_IN_TX;
		}
	}

	if (signal == B_TRUE)
		cv_broadcast(&odd->odd_iowait);
}

static void
overlay_io_wait(overlay_dev_t *odd, overlay_dev_flag_t flag)
{
	ASSERT((flag & ~OVERLAY_F_IOMASK) == 0);
	ASSERT(MUTEX_HELD(&odd->odd_lock));

	while (odd->odd_flags & flag) {
		cv_wait(&odd->odd_iowait, &odd->odd_lock);
	}
}

void
overlay_dev_iter(overlay_dev_iter_f func, void *arg)
{
	overlay_dev_t *odd;

	mutex_enter(&overlay_dev_lock);
	for (odd = list_head(&overlay_dev_list); odd != NULL;
	    odd = list_next(&overlay_dev_list, odd)) {
		if (func(odd, arg) != 0) {
			mutex_exit(&overlay_dev_lock);
			return;
		}
	}
	mutex_exit(&overlay_dev_lock);
}

/* ARGSUSED */
static int
overlay_m_stat(void *arg, uint_t stat, uint64_t *val)
{
	return (ENOTSUP);
}

static int
overlay_m_start(void *arg)
{
	overlay_dev_t *odd = arg;
	overlay_mux_t *mux;
	int ret, domain, family, prot;
	struct sockaddr_storage storage;
	socklen_t slen;

	mutex_enter(&odd->odd_lock);
	if ((odd->odd_flags & OVERLAY_F_ACTIVATED) == 0) {
		mutex_exit(&odd->odd_lock);
		return (EAGAIN);
	}
	mutex_exit(&odd->odd_lock);

	ret = odd->odd_plugin->ovp_ops->ovpo_socket(odd->odd_pvoid, &domain,
	    &family, &prot, (struct sockaddr *)&storage, &slen);
	if (ret != 0)
		return (ret);

	mux = overlay_mux_open(odd->odd_plugin, domain, family, prot,
	    (struct sockaddr *)&storage, slen, &ret);
	if (mux == NULL)
		return (ret);

	overlay_mux_add_dev(mux, odd);
	odd->odd_mux = mux;
	mutex_enter(&odd->odd_lock);
	ASSERT(!(odd->odd_flags & OVERLAY_F_IN_MUX));
	odd->odd_flags |= OVERLAY_F_IN_MUX;
	mutex_exit(&odd->odd_lock);

	return (0);
}

static void
overlay_m_stop(void *arg)
{
	overlay_dev_t *odd = arg;

	/*
	 * The MAC Perimeter is held here, so we don't have to worry about
	 * synchronizing this with respect to metadata operations.
	 */
	mutex_enter(&odd->odd_lock);
	VERIFY(odd->odd_flags & OVERLAY_F_IN_MUX);
	VERIFY(!(odd->odd_flags & OVERLAY_F_MDDROP));
	odd->odd_flags |= OVERLAY_F_MDDROP;
	overlay_io_wait(odd, OVERLAY_F_IOMASK);
	mutex_exit(&odd->odd_lock);

	overlay_mux_remove_dev(odd->odd_mux, odd);
	overlay_mux_close(odd->odd_mux);
	odd->odd_mux = NULL;

	mutex_enter(&odd->odd_lock);
	odd->odd_flags &= ~OVERLAY_F_IN_MUX;
	odd->odd_flags &= ~OVERLAY_F_MDDROP;
	VERIFY((odd->odd_flags & OVERLAY_F_STOPMASK) == 0);
	mutex_exit(&odd->odd_lock);
}

/*
 * For more info on this, see the big theory statement.
 */
/* ARGSUSED */
static int
overlay_m_promisc(void *arg, boolean_t on)
{
	return (0);
}

/*
 * For more info on this, see the big theory statement.
 */
/* ARGSUSED */
static int
overlay_m_multicast(void *arg, boolean_t add, const uint8_t *addrp)
{
	return (0);
}

/*
 * For more info on this, see the big theory statement.
 */
/* ARGSUSED */
static int
overlay_m_unicast(void *arg, const uint8_t *macaddr)
{
	return (0);
}

mblk_t *
overlay_m_tx(void *arg, mblk_t *mp_chain)
{
	overlay_dev_t *odd = arg;
	mblk_t *mp, *ep;
	int ret;
	ovep_encap_info_t einfo;
	struct msghdr hdr;

	mutex_enter(&odd->odd_lock);
	if ((odd->odd_flags & OVERLAY_F_MDDROP) ||
	    !(odd->odd_flags & OVERLAY_F_IN_MUX)) {
		mutex_exit(&odd->odd_lock);
		freemsgchain(mp_chain);
		return (NULL);
	}
	overlay_io_start(odd, OVERLAY_F_IN_TX);
	mutex_exit(&odd->odd_lock);

	bzero(&hdr, sizeof (struct msghdr));

	bzero(&einfo, sizeof (ovep_encap_info_t));
	einfo.ovdi_id = odd->odd_vid;
	mp = mp_chain;
	while (mp != NULL) {
		socklen_t slen;
		struct sockaddr_storage storage;

		mp_chain = mp->b_next;
		mp->b_next = NULL;
		ep = NULL;

		ret = overlay_target_lookup(odd, mp,
		    (struct sockaddr *)&storage, &slen);
		if (ret != OVERLAY_TARGET_OK) {
			if (ret == OVERLAY_TARGET_DROP)
				freemsg(mp);
			mp = mp_chain;
			continue;
		}

		hdr.msg_name = &storage;
		hdr.msg_namelen = slen;

		ret = odd->odd_plugin->ovp_ops->ovpo_encap(odd->odd_mh, mp,
		    &einfo, &ep);
		if (ret != 0 || ep == NULL) {
			freemsg(mp);
			goto out;
		}

		ASSERT(ep->b_cont == mp || ep == mp);
		ret = overlay_mux_tx(odd->odd_mux, &hdr, ep);
		if (ret != 0)
			goto out;

		mp = mp_chain;
	}

out:
	mutex_enter(&odd->odd_lock);
	overlay_io_done(odd, OVERLAY_F_IN_TX);
	mutex_exit(&odd->odd_lock);
	return (mp_chain);
}

/* ARGSUSED */
static void
overlay_m_ioctl(void *arg, queue_t *q, mblk_t *mp)
{
	miocnak(q, mp, 0, ENOTSUP);
}

/* ARGSUSED */
static boolean_t
overlay_m_getcapab(void *arg, mac_capab_t cap, void *cap_data)
{
	/*
	 * Tell MAC we're an overlay.
	 */
	if (cap == MAC_CAPAB_OVERLAY)
		return (B_TRUE);
	return (B_FALSE);
}

/* ARGSUSED */
static int
overlay_m_setprop(void *arg, const char *pr_name, mac_prop_id_t pr_num,
    uint_t pr_valsize, const void *pr_val)
{
	uint32_t mtu, old;
	int err;
	overlay_dev_t *odd = arg;

	if (pr_num != MAC_PROP_MTU)
		return (ENOTSUP);

	bcopy(pr_val, &mtu, sizeof (mtu));
	if (mtu < OVERLAY_MTU_MIN || mtu > OVERLAY_MTU_MAX)
		return (EINVAL);

	mutex_enter(&odd->odd_lock);
	old = odd->odd_mtu;
	odd->odd_mtu = mtu;
	err = mac_maxsdu_update(odd->odd_mh, mtu);
	if (err != 0)
		odd->odd_mtu = old;
	mutex_exit(&odd->odd_lock);

	return (err);
}

/* ARGSUSED */
static int
overlay_m_getprop(void *arg, const char *pr_name, mac_prop_id_t pr_num,
    uint_t pr_valsize, void *pr_val)
{
	return (ENOTSUP);
}

/* ARGSUSED */
static void
overlay_m_propinfo(void *arg, const char *pr_name, mac_prop_id_t pr_num,
    mac_prop_info_handle_t prh)
{
	if (pr_num != MAC_PROP_MTU)
		return;

	mac_prop_info_set_default_uint32(prh, OVERLAY_MTU_DEF);
	mac_prop_info_set_range_uint32(prh, OVERLAY_MTU_MIN, OVERLAY_MTU_MAX);
}

static mac_callbacks_t overlay_m_callbacks = {
	.mc_callbacks = (MC_IOCTL | MC_GETCAPAB | MC_SETPROP | MC_GETPROP |
	    MC_PROPINFO),
	.mc_getstat = overlay_m_stat,
	.mc_start = overlay_m_start,
	.mc_stop = overlay_m_stop,
	.mc_setpromisc = overlay_m_promisc,
	.mc_multicst = overlay_m_multicast,
	.mc_unicst = overlay_m_unicast,
	.mc_tx = overlay_m_tx,
	.mc_ioctl = overlay_m_ioctl,
	.mc_getcapab = overlay_m_getcapab,
	.mc_getprop = overlay_m_getprop,
	.mc_setprop = overlay_m_setprop,
	.mc_propinfo = overlay_m_propinfo
};

static boolean_t
overlay_valid_name(const char *name, size_t buflen)
{
	size_t actlen;
	int err, i;

	for (i = 0; i < buflen; i++) {
		if (name[i] == '\0')
			break;
	}

	if (i == 0 || i == buflen)
		return (B_FALSE);
	actlen = i;
	if (strchr(name, '/') != NULL)
		return (B_FALSE);
	if (u8_validate((char *)name, actlen, NULL,
	    U8_VALIDATE_ENTIRE, &err) < 0)
		return (B_FALSE);
	return (B_TRUE);
}

/* ARGSUSED */
static int
overlay_i_create(void *karg, intptr_t arg, int mode, cred_t *cred, int *rvalp)
{
	int err;
	uint64_t maxid;
	overlay_dev_t *odd, *o;
	mac_register_t *mac;
	overlay_ioc_create_t *oicp = karg;

	if (overlay_valid_name(oicp->oic_encap, MAXLINKNAMELEN) == B_FALSE)
		return (EINVAL);

	odd = kmem_zalloc(sizeof (overlay_dev_t), KM_SLEEP);
	odd->odd_linkid = oicp->oic_linkid;
	odd->odd_plugin = overlay_plugin_lookup(oicp->oic_encap);
	if (odd->odd_plugin == NULL) {
		kmem_free(odd, sizeof (overlay_dev_t));
		return (ENOENT);
	}
	err = odd->odd_plugin->ovp_ops->ovpo_init((overlay_handle_t)odd,
	    &odd->odd_pvoid);
	if (err != 0) {
		odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
		overlay_plugin_rele(odd->odd_plugin);
		kmem_free(odd, sizeof (overlay_dev_t));
		return (EINVAL);
	}

	/*
	 * Make sure that our virtual network id is valid for the given plugin
	 * that we're working with.
	 */
	ASSERT(odd->odd_plugin->ovp_id_size <= 8);
	maxid = UINT64_MAX;
	if (odd->odd_plugin->ovp_id_size != 8)
		maxid = (1ULL << (odd->odd_plugin->ovp_id_size * 8)) - 1ULL;
	if (oicp->oic_vnetid > maxid) {
		odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
		overlay_plugin_rele(odd->odd_plugin);
		kmem_free(odd, sizeof (overlay_dev_t));
		return (EINVAL);
	}
	odd->odd_vid = oicp->oic_vnetid;

	mac = mac_alloc(MAC_VERSION);
	if (mac == NULL) {
		mutex_exit(&overlay_dev_lock);
		odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
		overlay_plugin_rele(odd->odd_plugin);
		kmem_free(odd, sizeof (overlay_dev_t));
		return (EINVAL);
	}

	mac->m_type_ident = MAC_PLUGIN_IDENT_ETHER;
	mac->m_driver = odd;
	mac->m_dip = overlay_dip;
	mac->m_dst_addr = NULL;
	mac->m_callbacks = &overlay_m_callbacks;
	mac->m_pdata = NULL;
	mac->m_pdata_size = 0;

	mac->m_priv_props = NULL;

	/* Let mac handle this itself. */
	mac->m_instance = (uint_t)-1;

	/*
	 * There is no real source address that should be used here, but saying
	 * that we're not ethernet is going to cause its own problems. At the
	 * end of the say, this is fine.
	 */
	mac->m_src_addr = overlay_macaddr;

	/*
	 * Start with the default MTU as the max SDU. If the MTU is changed, the
	 * SDU will be changed to reflect that.
	 */
	mac->m_min_sdu = 1;
	mac->m_max_sdu = OVERLAY_MTU_DEF;
	mac->m_multicast_sdu = 0;

	/*
	 * The underlying device doesn't matter, instead this comes from the
	 * encapsulation protocol and whether or not they allow VLAN tags.
	 */
	if (odd->odd_plugin->ovp_flags & OVEP_F_VLAN_TAG) {
		mac->m_margin = VLAN_TAGSZ;
	} else {
		mac->m_margin = 0;
	}

	/*
	 * Today, we have no MAC virtualization, it may make sense in the future
	 * to go ahead and emulate some subset of this, but it doesn't today.
	 */
	mac->m_v12n = MAC_VIRT_NONE;

	mutex_enter(&overlay_dev_lock);
	for (o = list_head(&overlay_dev_list); o != NULL;
	    o = list_next(&overlay_dev_list, o)) {
		if (o->odd_linkid == oicp->oic_linkid) {
			mutex_exit(&overlay_dev_lock);
			odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
			overlay_plugin_rele(odd->odd_plugin);
			kmem_free(odd, sizeof (overlay_dev_t));
			return (EEXIST);
		}

		if (o->odd_vid == oicp->oic_vnetid &&
		    o->odd_plugin == odd->odd_plugin) {
			mutex_exit(&overlay_dev_lock);
			odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
			overlay_plugin_rele(odd->odd_plugin);
			kmem_free(odd, sizeof (overlay_dev_t));
			return (EEXIST);
		}
	}

	err = mac_register(mac, &odd->odd_mh);
	mac_free(mac);
	if (err != 0) {
		mutex_exit(&overlay_dev_lock);
		odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
		overlay_plugin_rele(odd->odd_plugin);
		kmem_free(odd, sizeof (overlay_dev_t));
		return (err);
	}

	err = dls_devnet_create(odd->odd_mh, odd->odd_linkid,
	    crgetzoneid(cred));
	if (err != 0) {
		mutex_exit(&overlay_dev_lock);
		(void) mac_unregister(odd->odd_mh);
		odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
		overlay_plugin_rele(odd->odd_plugin);
		kmem_free(odd, sizeof (overlay_dev_t));
		return (err);
	}

	mutex_init(&odd->odd_lock, NULL, MUTEX_DRIVER, NULL);
	cv_init(&odd->odd_iowait, NULL, CV_DRIVER, NULL);
	odd->odd_ref = 0;
	odd->odd_flags = 0;
	list_insert_tail(&overlay_dev_list, odd);
	mutex_exit(&overlay_dev_lock);

	return (0);
}

/* ARGSUSED */
static int
overlay_i_activate(void *karg, intptr_t arg, int mode, cred_t *cred, int *rvalp)
{
	int i, ret;
	overlay_dev_t *odd;
	mac_perim_handle_t mph;
	overlay_ioc_activate_t *oiap = karg;
	overlay_ioc_propinfo_t *infop;
	overlay_ioc_prop_t *oip;
	overlay_prop_handle_t phdl;

	odd = overlay_hold_by_dlid(oiap->oia_linkid);
	if (odd == NULL)
		return (ENOENT);

	infop = kmem_alloc(sizeof (overlay_ioc_propinfo_t), KM_SLEEP);
	oip = kmem_alloc(sizeof (overlay_ioc_prop_t), KM_SLEEP);
	phdl = (overlay_prop_handle_t)infop;

	mac_perim_enter_by_mh(odd->odd_mh, &mph);
	mutex_enter(&odd->odd_lock);
	if (odd->odd_flags & OVERLAY_F_ACTIVATED) {
		mutex_exit(&odd->odd_lock);
		mac_perim_exit(mph);
		overlay_hold_rele(odd);
		kmem_free(infop, sizeof (overlay_ioc_propinfo_t));
		kmem_free(oip, sizeof (overlay_ioc_prop_t));
		return (EEXIST);
	}
	mutex_exit(&odd->odd_lock);

	for (i = 0; i < odd->odd_plugin->ovp_nprops; i++) {
		const char *pname = odd->odd_plugin->ovp_props[i];
		bzero(infop, sizeof (overlay_ioc_propinfo_t));
		overlay_prop_init(phdl);
		ret = odd->odd_plugin->ovp_ops->ovpo_propinfo(pname, phdl);
		if (ret != 0) {
			mac_perim_exit(mph);
			overlay_hold_rele(odd);
			kmem_free(infop, sizeof (overlay_ioc_propinfo_t));
			kmem_free(oip, sizeof (overlay_ioc_prop_t));
			return (ret);
		}

		if ((infop->oipi_prot & OVERLAY_PROP_PERM_REQ) == 0)
			continue;
		bzero(oip, sizeof (overlay_ioc_prop_t));
		oip->oip_size = sizeof (oip->oip_value);
		ret = odd->odd_plugin->ovp_ops->ovpo_getprop(odd->odd_pvoid,
		    pname, oip->oip_value, &oip->oip_size);
		if (ret != 0) {
			mac_perim_exit(mph);
			overlay_hold_rele(odd);
			kmem_free(infop, sizeof (overlay_ioc_propinfo_t));
			kmem_free(oip, sizeof (overlay_ioc_prop_t));
			return (ret);
		}
		if (oip->oip_size == 0) {
			mac_perim_exit(mph);
			overlay_hold_rele(odd);
			kmem_free(infop, sizeof (overlay_ioc_propinfo_t));
			kmem_free(oip, sizeof (overlay_ioc_prop_t));
			return (EINVAL);
		}
	}

	mutex_enter(&odd->odd_lock);
	if ((odd->odd_flags & OVERLAY_F_VARPD) == 0) {
		mutex_exit(&odd->odd_lock);
		mac_perim_exit(mph);
		overlay_hold_rele(odd);
		kmem_free(infop, sizeof (overlay_ioc_propinfo_t));
		kmem_free(oip, sizeof (overlay_ioc_prop_t));
		return (ENXIO);
	}

	ASSERT((odd->odd_flags & OVERLAY_F_ACTIVATED) == 0);
	odd->odd_flags |= OVERLAY_F_ACTIVATED;

	/*
	 * Now that we've activated ourselves, we should indicate to the world
	 * that we're up. Note that we may not be able to perform lookups at
	 * this time, but our notion of being 'up' isn't dependent on that
	 * ability.
	 */
	mac_link_update(odd->odd_mh, LINK_STATE_UP);
	mutex_exit(&odd->odd_lock);

	mac_perim_exit(mph);
	overlay_hold_rele(odd);
	kmem_free(infop, sizeof (overlay_ioc_propinfo_t));
	kmem_free(oip, sizeof (overlay_ioc_prop_t));

	return (0);
}

/* ARGSUSED */
static int
overlay_i_delete(void *karg, intptr_t arg, int mode, cred_t *cred, int *rvalp)
{
	overlay_ioc_delete_t *oidp = karg;
	overlay_dev_t *odd;
	datalink_id_t tid;
	int ret;

	odd = overlay_hold_by_dlid(oidp->oid_linkid);
	if (odd == NULL) {
		return (ENOENT);
	}

	mutex_enter(&odd->odd_lock);
	/* If we're not the only hold, we're busy */
	if (odd->odd_ref != 1) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (EBUSY);
	}

	if (odd->odd_flags & OVERLAY_F_IN_MUX) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (EBUSY);
	}

	/*
	 * To remove this, we need to first remove it from dls and then remove
	 * it from mac. The act of removing it from mac will check if there are
	 * devices on top of this, eg. vnics. If there are, then that will fail
	 * and we'll have to go through and recreate the dls entry. Only after
	 * mac_unregister has succeeded, then we'll go through and actually free
	 * everything and drop the dev lock.
	 */
	ret = dls_devnet_destroy(odd->odd_mh, &tid, B_TRUE);
	if (ret != 0) {
		overlay_hold_rele(odd);
		return (ret);
	}

	ASSERT(oidp->oid_linkid == tid);
	ret = mac_disable(odd->odd_mh);
	if (ret != 0) {
		(void) dls_devnet_create(odd->odd_mh, odd->odd_linkid,
		    crgetzoneid(cred));
		overlay_hold_rele(odd);
		return (ret);
	}

	overlay_target_quiesce(odd->odd_target);

	mutex_enter(&overlay_dev_lock);
	list_remove(&overlay_dev_list, odd);
	mutex_exit(&overlay_dev_lock);

	cv_destroy(&odd->odd_iowait);
	mutex_destroy(&odd->odd_lock);
	overlay_target_free(odd);
	odd->odd_plugin->ovp_ops->ovpo_fini(odd->odd_pvoid);
	overlay_plugin_rele(odd->odd_plugin);
	kmem_free(odd, sizeof (overlay_dev_t));

	return (0);
}

/* ARGSUSED */
static int
overlay_i_nprops(void *karg, intptr_t arg, int mode, cred_t *cred,
    int *rvalp)
{
	overlay_dev_t *odd;
	overlay_ioc_nprops_t *on = karg;

	odd = overlay_hold_by_dlid(on->oipn_linkid);
	if (odd == NULL)
		return (ENOENT);
	on->oipn_nprops = odd->odd_plugin->ovp_nprops + OVERLAY_DEV_NPROPS;
	overlay_hold_rele(odd);

	return (0);
}

static int
overlay_propinfo_plugin_cb(overlay_plugin_t *opp, void *arg)
{
	overlay_prop_handle_t phdl = arg;
	overlay_prop_set_range_str(phdl, opp->ovp_name);
	return (0);
}

static int
overlay_i_name_to_propid(overlay_dev_t *odd, const char *name, uint_t *id)
{
	int i;

	for (i = 0; i < OVERLAY_DEV_NPROPS; i++) {
		if (strcmp(overlay_dev_props[i], name) == 0) {
			*id = i;
			return (0);
		}
	}

	for (i = 0; i < odd->odd_plugin->ovp_nprops; i++) {
		if (strcmp(odd->odd_plugin->ovp_props[i], name) == 0) {
			*id = i + OVERLAY_DEV_NPROPS;
			return (0);
		}
	}

	return (ENOENT);
}

static void
overlay_i_propinfo_mtu(overlay_dev_t *odd, overlay_prop_handle_t phdl)
{
	uint32_t def;
	mac_propval_range_t range;
	uint_t perm;

	ASSERT(MAC_PERIM_HELD(odd->odd_mh));

	bzero(&range, sizeof (mac_propval_range_t));
	range.mpr_count = 1;
	if (mac_prop_info(odd->odd_mh, MAC_PROP_MTU, "mtu", &def,
	    sizeof (def), &range, &perm) != 0)
		return;

	if (perm == MAC_PROP_PERM_READ)
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_READ);
	else if (perm == MAC_PROP_PERM_WRITE)
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_WRITE);
	else if (perm == MAC_PROP_PERM_RW)
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_RW);

	overlay_prop_set_type(phdl, OVERLAY_PROP_T_UINT);
	overlay_prop_set_default(phdl, &def, sizeof (def));
	overlay_prop_set_range_uint32(phdl, range.mpr_range_uint32[0].mpur_min,
	    range.mpr_range_uint32[0].mpur_max);
}

/* ARGSUSED */
static int
overlay_i_propinfo(void *karg, intptr_t arg, int mode, cred_t *cred,
    int *rvalp)
{
	overlay_dev_t *odd;
	int ret;
	mac_perim_handle_t mph;
	uint_t propid = UINT_MAX;
	overlay_ioc_propinfo_t *oip = karg;
	overlay_prop_handle_t phdl = (overlay_prop_handle_t)oip;

	odd = overlay_hold_by_dlid(oip->oipi_linkid);
	if (odd == NULL)
		return (ENOENT);

	overlay_prop_init(phdl);
	mac_perim_enter_by_mh(odd->odd_mh, &mph);

	/*
	 * If the id is -1, then the property that we're looking for is named in
	 * oipi_name and we should fill in its id. Otherwise, we've been given
	 * an id and we need to turn that into a name for our plugin's sake. The
	 * id is our own fabrication for property discovery.
	 */
	if (oip->oipi_id == -1) {
		/*
		 * Determine if it's a known generic property or it belongs to a
		 * module by checking against the list of known names.
		 */
		oip->oipi_name[OVERLAY_PROP_NAMELEN-1] = '\0';
		if ((ret = overlay_i_name_to_propid(odd, oip->oipi_name,
		    &propid)) != 0) {
			overlay_hold_rele(odd);
			mac_perim_exit(mph);
			return (ret);
		}
		oip->oipi_id = propid;
		if (propid >= OVERLAY_DEV_NPROPS) {
			ret = odd->odd_plugin->ovp_ops->ovpo_propinfo(
			    oip->oipi_name, phdl);
			overlay_hold_rele(odd);
			mac_perim_exit(mph);
			return (ret);

		}
	} else if (oip->oipi_id >= OVERLAY_DEV_NPROPS) {
		uint_t id = oip->oipi_id - OVERLAY_DEV_NPROPS;

		if (id >= odd->odd_plugin->ovp_nprops) {
			overlay_hold_rele(odd);
			mac_perim_exit(mph);
			return (EINVAL);
		}
		ret = odd->odd_plugin->ovp_ops->ovpo_propinfo(
		    odd->odd_plugin->ovp_props[id], phdl);
		overlay_hold_rele(odd);
		mac_perim_exit(mph);
		return (ret);
	} else if (oip->oipi_id < -1) {
		overlay_hold_rele(odd);
		mac_perim_exit(mph);
		return (EINVAL);
	} else {
		ASSERT(oip->oipi_id < OVERLAY_DEV_NPROPS);
		ASSERT(oip->oipi_id >= 0);
		propid = oip->oipi_id;
		(void) strlcpy(oip->oipi_name, overlay_dev_props[propid],
		    sizeof (oip->oipi_name));
	}

	switch (propid) {
	case OVERLAY_DEV_P_MTU:
		overlay_i_propinfo_mtu(odd, phdl);
		break;
	case OVERLAY_DEV_P_VNETID:
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_RW);
		overlay_prop_set_type(phdl, OVERLAY_PROP_T_UINT);
		overlay_prop_set_nodefault(phdl);
		break;
	case OVERLAY_DEV_P_ENCAP:
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_READ);
		overlay_prop_set_type(phdl, OVERLAY_PROP_T_STRING);
		overlay_prop_set_nodefault(phdl);
		overlay_plugin_walk(overlay_propinfo_plugin_cb, phdl);
		break;
	case OVERLAY_DEV_P_VARPDID:
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_READ);
		overlay_prop_set_type(phdl, OVERLAY_PROP_T_UINT);
		overlay_prop_set_nodefault(phdl);
		break;
	default:
		overlay_hold_rele(odd);
		mac_perim_exit(mph);
		return (ENOENT);
	}

	overlay_hold_rele(odd);
	mac_perim_exit(mph);
	return (0);
}

/* ARGSUSED */
static int
overlay_i_getprop(void *karg, intptr_t arg, int mode, cred_t *cred,
    int *rvalp)
{
	int ret;
	overlay_dev_t *odd;
	mac_perim_handle_t mph;
	overlay_ioc_prop_t *oip = karg;
	uint_t propid, mtu;

	odd = overlay_hold_by_dlid(oip->oip_linkid);
	if (odd == NULL)
		return (ENOENT);

	mac_perim_enter_by_mh(odd->odd_mh, &mph);
	oip->oip_size = OVERLAY_PROP_SIZEMAX;
	oip->oip_name[OVERLAY_PROP_NAMELEN-1] = '\0';
	if (oip->oip_id == -1) {
		int i;

		for (i = 0; i < OVERLAY_DEV_NPROPS; i++) {
			if (strcmp(overlay_dev_props[i], oip->oip_name) == 0)
				break;
			if (i == OVERLAY_DEV_NPROPS) {
				ret = odd->odd_plugin->ovp_ops->ovpo_getprop(
				    odd->odd_pvoid, oip->oip_name,
				    oip->oip_value, &oip->oip_size);
				overlay_hold_rele(odd);
				mac_perim_exit(mph);
				return (ret);
			}
		}

		propid = i;
	} else if (oip->oip_id >= OVERLAY_DEV_NPROPS) {
		uint_t id = oip->oip_id - OVERLAY_DEV_NPROPS;

		if (id > odd->odd_plugin->ovp_nprops) {
			overlay_hold_rele(odd);
			mac_perim_exit(mph);
			return (EINVAL);
		}
		ret = odd->odd_plugin->ovp_ops->ovpo_getprop(odd->odd_pvoid,
		    odd->odd_plugin->ovp_props[id], oip->oip_value,
		    &oip->oip_size);
		overlay_hold_rele(odd);
		mac_perim_exit(mph);
		return (ret);
	} else if (oip->oip_id < -1) {
		overlay_hold_rele(odd);
		mac_perim_exit(mph);
		return (EINVAL);
	} else {
		ASSERT(oip->oip_id < OVERLAY_DEV_NPROPS);
		ASSERT(oip->oip_id >= 0);
		propid = oip->oip_id;
	}

	ret = 0;
	switch (propid) {
	case OVERLAY_DEV_P_MTU:
		/*
		 * The MTU is always set and retrieved through MAC, to allow for
		 * MAC to do whatever it wants, as really that property belongs
		 * to MAC. This is important for things where vnics have hold on
		 * the MTU.
		 */
		mac_sdu_get(odd->odd_mh, NULL, &mtu);
		bcopy(&mtu, oip->oip_value, sizeof (uint_t));
		oip->oip_size = sizeof (uint_t);
		break;
	case OVERLAY_DEV_P_VNETID:
		/*
		 * While it's read-only while inside of a mux, we're not in a
		 * context that can guarantee that. Therefore we always grab the
		 * overlay_dev_t's odd_lock.
		 */
		mutex_enter(&odd->odd_lock);
		bcopy(&odd->odd_vid, oip->oip_value, sizeof (uint64_t));
		mutex_exit(&odd->odd_lock);
		oip->oip_size = sizeof (uint64_t);
		break;
	case OVERLAY_DEV_P_ENCAP:
		oip->oip_size = strlcpy((char *)oip->oip_value,
		    odd->odd_plugin->ovp_name, oip->oip_size);
		break;
	case OVERLAY_DEV_P_VARPDID:
		mutex_enter(&odd->odd_lock);
		if (odd->odd_flags & OVERLAY_F_VARPD) {
			const uint64_t val = odd->odd_target->ott_id;
			bcopy(&val, oip->oip_value, sizeof (uint64_t));
			oip->oip_size = sizeof (uint64_t);
		} else {
			oip->oip_size = 0;
		}
		mutex_exit(&odd->odd_lock);
		break;
	default:
		ret = ENOENT;
	}

	overlay_hold_rele(odd);
	mac_perim_exit(mph);
	return (ret);
}

static void
overlay_setprop_vnetid(overlay_dev_t *odd, uint64_t vnetid)
{
	mutex_enter(&odd->odd_lock);

	/* Simple case, not active */
	if (!(odd->odd_flags & OVERLAY_F_IN_MUX)) {
		odd->odd_vid = vnetid;
		mutex_exit(&odd->odd_lock);
		return;
	}

	/*
	 * In the hard case, we need to set the drop flag, quiesce I/O and then
	 * we can go ahead and do everything.
	 */
	odd->odd_flags |= OVERLAY_F_MDDROP;
	overlay_io_wait(odd, OVERLAY_F_IOMASK);
	mutex_exit(&odd->odd_lock);

	overlay_mux_remove_dev(odd->odd_mux, odd);

	mutex_enter(&odd->odd_lock);
	odd->odd_vid = vnetid;
	mutex_exit(&odd->odd_lock);

	overlay_mux_add_dev(odd->odd_mux, odd);

	mutex_enter(&odd->odd_lock);
	ASSERT(odd->odd_flags & OVERLAY_F_IN_MUX);
	odd->odd_flags &= ~OVERLAY_F_MDDROP;
	mutex_exit(&odd->odd_lock);
}

/* ARGSUSED */
static int
overlay_i_setprop(void *karg, intptr_t arg, int mode, cred_t *cred,
    int *rvalp)
{
	int ret;
	overlay_dev_t *odd;
	overlay_ioc_prop_t *oip = karg;
	uint_t propid = UINT_MAX;
	mac_perim_handle_t mph;
	uint64_t maxid, *vidp;

	if (oip->oip_size > OVERLAY_PROP_SIZEMAX)
		return (EINVAL);

	odd = overlay_hold_by_dlid(oip->oip_linkid);
	if (odd == NULL)
		return (ENOENT);

	oip->oip_name[OVERLAY_PROP_NAMELEN-1] = '\0';
	mac_perim_enter_by_mh(odd->odd_mh, &mph);
	mutex_enter(&odd->odd_lock);
	if (odd->odd_flags & OVERLAY_F_ACTIVATED) {
		mac_perim_exit(mph);
		mutex_exit(&odd->odd_lock);
		return (ENOTSUP);
	}
	mutex_exit(&odd->odd_lock);
	if (oip->oip_id == -1) {
		int i;

		for (i = 0; i < OVERLAY_DEV_NPROPS; i++) {
			if (strcmp(overlay_dev_props[i], oip->oip_name) == 0)
				break;
			if (i == OVERLAY_DEV_NPROPS) {
				ret = odd->odd_plugin->ovp_ops->ovpo_setprop(
				    odd->odd_pvoid, oip->oip_name,
				    oip->oip_value, oip->oip_size);
				overlay_hold_rele(odd);
				mac_perim_exit(mph);
				return (ret);
			}
		}

		propid = i;
	} else if (oip->oip_id >= OVERLAY_DEV_NPROPS) {
		uint_t id = oip->oip_id - OVERLAY_DEV_NPROPS;

		if (id > odd->odd_plugin->ovp_nprops) {
			mac_perim_exit(mph);
			overlay_hold_rele(odd);
			return (EINVAL);
		}
		ret = odd->odd_plugin->ovp_ops->ovpo_setprop(odd->odd_pvoid,
		    odd->odd_plugin->ovp_props[id], oip->oip_value,
		    oip->oip_size);
		mac_perim_exit(mph);
		overlay_hold_rele(odd);
		return (ret);
	} else if (oip->oip_id < -1) {
		mac_perim_exit(mph);
		overlay_hold_rele(odd);
		return (EINVAL);
	} else {
		ASSERT(oip->oip_id < OVERLAY_DEV_NPROPS);
		ASSERT(oip->oip_id >= 0);
		propid = oip->oip_id;
	}

	ret = 0;
	switch (propid) {
	case OVERLAY_DEV_P_MTU:
		ret = mac_set_prop(odd->odd_mh, MAC_PROP_MTU, "mtu",
		    oip->oip_value, oip->oip_size);
		break;
	case OVERLAY_DEV_P_VNETID:
		if (oip->oip_size != sizeof (uint64_t)) {
			ret = EINVAL;
			break;
		}
		vidp = (uint64_t *)oip->oip_value;
		ASSERT(odd->odd_plugin->ovp_id_size <= 8);
		maxid = UINT64_MAX;
		if (odd->odd_plugin->ovp_id_size != 8)
			maxid = (1ULL << (odd->odd_plugin->ovp_id_size * 8)) -
			    1ULL;
		if (*vidp >= maxid) {
			ret = EINVAL;
			break;
		}
		overlay_setprop_vnetid(odd, *vidp);
		break;
	case OVERLAY_DEV_P_ENCAP:
	case OVERLAY_DEV_P_VARPDID:
		ret = EPERM;
		break;
	default:
		ret = ENOENT;
	}

	mac_perim_exit(mph);
	overlay_hold_rele(odd);
	return (ret);
}

/* ARGSUSED */
static int
overlay_i_status(void *karg, intptr_t arg, int mode, cred_t *cred,
    int *rvalp)
{
	overlay_dev_t *odd;
	overlay_ioc_status_t *os = karg;

	odd = overlay_hold_by_dlid(os->ois_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	if ((odd->odd_flags & OVERLAY_F_DEGRADED) != 0) {
		os->ois_status = OVERLAY_I_DEGRADED;
		(void) strlcpy(os->ois_message, odd->odd_fmamsg,
		    OVERLAY_STATUS_BUFLEN);
	} else {
		os->ois_status = OVERLAY_I_OK;
		os->ois_message[0] = '\0';
	}
	mutex_exit(&odd->odd_lock);
	overlay_hold_rele(odd);

	return (0);
}

static dld_ioc_info_t overlay_ioc_list[] = {
	{ OVERLAY_IOC_CREATE, DLDCOPYIN, sizeof (overlay_ioc_create_t),
		overlay_i_create, secpolicy_dl_config },
	{ OVERLAY_IOC_ACTIVATE, DLDCOPYIN, sizeof (overlay_ioc_activate_t),
		overlay_i_activate, secpolicy_dl_config },
	{ OVERLAY_IOC_DELETE, DLDCOPYIN, sizeof (overlay_ioc_delete_t),
		overlay_i_delete, secpolicy_dl_config },
	{ OVERLAY_IOC_PROPINFO, DLDCOPYIN | DLDCOPYOUT,
		sizeof (overlay_ioc_propinfo_t), overlay_i_propinfo,
		secpolicy_dl_config },
	{ OVERLAY_IOC_GETPROP, DLDCOPYIN | DLDCOPYOUT,
		sizeof (overlay_ioc_prop_t), overlay_i_getprop,
		secpolicy_dl_config },
	{ OVERLAY_IOC_SETPROP, DLDCOPYIN,
		sizeof (overlay_ioc_prop_t), overlay_i_setprop,
		secpolicy_dl_config },
	{ OVERLAY_IOC_NPROPS, DLDCOPYIN | DLDCOPYOUT,
		sizeof (overlay_ioc_nprops_t), overlay_i_nprops,
		secpolicy_dl_config },
	{ OVERLAY_IOC_STATUS, DLDCOPYIN | DLDCOPYOUT,
		sizeof (overlay_ioc_status_t), overlay_i_status,
		NULL }
};

static int
overlay_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
	int fmcap = DDI_FM_EREPORT_CAPABLE;
	if (cmd != DDI_ATTACH)
		return (DDI_FAILURE);

	if (overlay_dip != NULL || ddi_get_instance(dip) != 0)
		return (DDI_FAILURE);

	ddi_fm_init(dip, &fmcap, NULL);

	if (ddi_create_minor_node(dip, OVERLAY_CTL, S_IFCHR,
	    ddi_get_instance(dip), DDI_PSEUDO, 0) == DDI_FAILURE)
		return (DDI_FAILURE);

	if (dld_ioc_register(OVERLAY_IOC, overlay_ioc_list,
	    DLDIOCCNT(overlay_ioc_list)) != 0) {
		ddi_remove_minor_node(dip, OVERLAY_CTL);
		return (DDI_FAILURE);
	}

	overlay_dip = dip;
	return (DDI_SUCCESS);
}

/* ARGSUSED */
static int
overlay_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg, void **resp)
{
	int error;

	switch (cmd) {
	case DDI_INFO_DEVT2DEVINFO:
		*resp = (void *)overlay_dip;
		error = DDI_SUCCESS;
		break;
	case DDI_INFO_DEVT2INSTANCE:
		*resp = (void *)0;
		error = DDI_SUCCESS;
		break;
	default:
		error = DDI_FAILURE;
		break;
	}

	return (error);
}

static int
overlay_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
	if (cmd != DDI_DETACH)
		return (DDI_FAILURE);

	mutex_enter(&overlay_dev_lock);
	if (!list_is_empty(&overlay_dev_list) || overlay_target_busy()) {
		mutex_exit(&overlay_dev_lock);
		return (EBUSY);
	}
	mutex_exit(&overlay_dev_lock);


	dld_ioc_unregister(OVERLAY_IOC);
	ddi_remove_minor_node(dip, OVERLAY_CTL);
	ddi_fm_fini(dip);
	overlay_dip = NULL;
	return (DDI_SUCCESS);
}

static struct cb_ops overlay_cbops = {
	overlay_target_open,	/* cb_open */
	overlay_target_close,	/* cb_close */
	nodev,			/* cb_strategy */
	nodev,			/* cb_print */
	nodev,			/* cb_dump */
	nodev,			/* cb_read */
	nodev,			/* cb_write */
	overlay_target_ioctl,	/* cb_ioctl */
	nodev,			/* cb_devmap */
	nodev,			/* cb_mmap */
	nodev,			/* cb_segmap */
	nochpoll,		/* cb_chpoll */
	ddi_prop_op,		/* cb_prop_op */
	NULL,			/* cb_stream */
	D_MP,			/* cb_flag */
	CB_REV,			/* cb_rev */
	nodev,			/* cb_aread */
	nodev,			/* cb_awrite */
};

static struct dev_ops overlay_dev_ops = {
	DEVO_REV,		/* devo_rev */
	0,			/* devo_refcnt */
	overlay_getinfo,	/* devo_getinfo */
	nulldev,		/* devo_identify */
	nulldev,		/* devo_probe */
	overlay_attach,		/* devo_attach */
	overlay_detach,		/* devo_detach */
	nulldev,		/* devo_reset */
	&overlay_cbops,		/* devo_cb_ops */
	NULL,			/* devo_bus_ops */
	NULL,			/* devo_power */
	ddi_quiesce_not_supported	/* devo_quiesce */
};

static struct modldrv overlay_modldrv = {
	&mod_driverops,
	"Overlay Network Driver",
	&overlay_dev_ops
};

static struct modlinkage overlay_linkage = {
	MODREV_1,
	&overlay_modldrv
};

static int
overlay_init(void)
{
	mutex_init(&overlay_dev_lock, NULL, MUTEX_DRIVER, NULL);
	list_create(&overlay_dev_list, sizeof (overlay_dev_t),
	    offsetof(overlay_dev_t, odd_link));
	overlay_mux_init();
	overlay_plugin_init();
	overlay_target_init();

	return (DDI_SUCCESS);
}

static void
overlay_fini(void)
{
	overlay_target_fini();
	overlay_plugin_fini();
	overlay_mux_fini();
	mutex_destroy(&overlay_dev_lock);
	list_destroy(&overlay_dev_list);
}

int
_init(void)
{
	int err;

	if ((err = overlay_init()) != DDI_SUCCESS)
		return (err);

	mac_init_ops(NULL, "overlay");
	err = mod_install(&overlay_linkage);
	if (err != DDI_SUCCESS) {
		overlay_fini();
		return (err);
	}

	return (0);
}

int
_info(struct modinfo *modinfop)
{
	return (mod_info(&overlay_linkage, modinfop));
}

int
_fini(void)
{
	int err;

	err = mod_remove(&overlay_linkage);
	if (err != 0)
		return (err);

	overlay_fini();
	return (0);
}
#
# This file and its contents are supplied under the terms of the
# Common Development and Distribution License ("CDDL"), version 1.0.
# You may only use this file in accordance with the terms of version
# 1.0 of the CDDL.
#
# A full copy of the text of the CDDL should have accompanied this
# source.  A copy of the CDDL is also available via the Internet at
# http://www.illumos.org/license/CDDL.
#

#
# Copyright 2015, Joyent, Inc.
#

name="overlay" parent="pseudo" instance=0;
#
# This file and its contents are supplied under the terms of the
# Common Development and Distribution License ("CDDL"), version 1.0.
# You may only use this file in accordance with the terms of version
# 1.0 of the CDDL.
#
# A full copy of the text of the CDDL should have accompanied this
# source.  A copy of the CDDL is also available via the Internet at
# http://www.illumos.org/license/CDDL.
#

#
# Copyright 2015 Joyent, Inc.
#

#
# MAPFILE HEADER START
#
# WARNING:  STOP NOW.  DO NOT MODIFY THIS FILE.
# Object versioning must comply with the rules detailed in
#
#	usr/src/lib/README.mapfiles
#
# You should not be making modifications here until you've read the most current
# copy of that file. If you need help, contact a gatekeeper for guidance.
#
# MAPFILE HEADER END
#

$mapfile_version 2

SYMBOL_VERSION ILLUMOSprivate {
    global:
	# DDI Interfaces
	_fini;
	_init;
	_info;

	# Encapsualation Plugin interfaces
	overlay_plugin_alloc;
	overlay_plugin_free;
	overlay_plugin_register;
	overlay_plugin_unregister;
    local:
	*;
};
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2016 Joyent, Inc.
 */

/*
 * Overlay device FMA operations.
 *
 * For more information, see the big theory statement in
 * uts/common/io/overlay/overlay.c
 */

#include <sys/ddifm.h>
#include <sys/overlay_impl.h>

kmutex_t overlay_fm_lock;
uint_t overlay_fm_count;

void
overlay_fm_init(void)
{
	overlay_fm_count = 0;
	mutex_init(&overlay_fm_lock, NULL, MUTEX_DRIVER, NULL);
}

void
overlay_fm_fini(void)
{
	VERIFY(overlay_fm_count == 0);
	mutex_destroy(&overlay_fm_lock);
}

void
overlay_fm_degrade(overlay_dev_t *odd, const char *msg)
{
	mutex_enter(&overlay_fm_lock);
	mutex_enter(&odd->odd_lock);

	if (msg != NULL)
		(void) strlcpy(odd->odd_fmamsg, msg, OVERLAY_STATUS_BUFLEN);

	if (odd->odd_flags & OVERLAY_F_DEGRADED)
		goto out;

	odd->odd_flags |= OVERLAY_F_DEGRADED;
	overlay_fm_count++;
	if (overlay_fm_count == 1) {
		ddi_fm_service_impact(overlay_dip, DDI_SERVICE_DEGRADED);
	}
out:
	mutex_exit(&odd->odd_lock);
	mutex_exit(&overlay_fm_lock);
}

void
overlay_fm_restore(overlay_dev_t *odd)
{
	mutex_enter(&overlay_fm_lock);
	mutex_enter(&odd->odd_lock);
	if (!(odd->odd_flags & OVERLAY_F_DEGRADED))
		goto out;

	odd->odd_fmamsg[0] = '\0';
	odd->odd_flags &= ~OVERLAY_F_DEGRADED;
	overlay_fm_count--;
	if (overlay_fm_count == 0) {
		ddi_fm_service_impact(overlay_dip, DDI_SERVICE_RESTORED);
	}
out:
	mutex_exit(&odd->odd_lock);
	mutex_exit(&overlay_fm_lock);
}
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2019 Joyent, Inc.
 */

/*
 * Overlay device ksocket multiplexer.
 *
 * For more information, see the big theory statement in
 * uts/common/io/overlay/overlay.c
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ksynch.h>
#include <sys/ksocket.h>
#include <sys/avl.h>
#include <sys/list.h>
#include <sys/pattr.h>
#include <sys/sysmacros.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/tihdr.h>

#include <sys/overlay_impl.h>

#include <sys/sdt.h>

static list_t overlay_mux_list;
static kmutex_t overlay_mux_lock;

void
overlay_mux_init(void)
{
	list_create(&overlay_mux_list, sizeof (overlay_mux_t),
	    offsetof(overlay_mux_t, omux_lnode));
	mutex_init(&overlay_mux_lock, NULL, MUTEX_DRIVER, NULL);
}

void
overlay_mux_fini(void)
{
	mutex_destroy(&overlay_mux_lock);
	list_destroy(&overlay_mux_list);
}

static int
overlay_mux_comparator(const void *a, const void *b)
{
	const overlay_dev_t *odl, *odr;
	odl = a;
	odr = b;
	if (odl->odd_vid > odr->odd_vid)
		return (1);
	else if (odl->odd_vid < odr->odd_vid)
		return (-1);
	else
		return (0);
}

/*
 * This is the central receive data path. We need to decode the packet, if we
 * can, and then deliver it to the appropriate overlay.
 */
/* ARGSUSED */
static boolean_t
overlay_mux_recv(ksocket_t ks, mblk_t *mpchain, size_t msgsize, int oob,
    void *arg)
{
	mblk_t *mp, *nmp, *fmp;
	overlay_mux_t *mux = arg;

	/*
	 * We may have a received a chain of messages. Each message in the
	 * chain will likely have a T_unitdata_ind attached to it as an M_PROTO.
	 * If we aren't getting that, we should probably drop that for the
	 * moment.
	 */
	for (mp = mpchain; mp != NULL; mp = nmp) {
		struct T_unitdata_ind *tudi;
		ovep_encap_info_t infop;
		overlay_dev_t od, *odd;
		int ret;

		nmp = mp->b_next;
		mp->b_next = NULL;

		if (DB_TYPE(mp) != M_PROTO) {
			OVERLAY_FREEMSG(mp, "first one isn't M_PROTO");
			freemsg(mp);
			continue;
		}

		if (mp->b_cont == NULL) {
			OVERLAY_FREEMSG(mp, "missing a b_cont");
			freemsg(mp);
			continue;
		}

		tudi = (struct T_unitdata_ind *)mp->b_rptr;
		if (tudi->PRIM_type != T_UNITDATA_IND) {
			OVERLAY_FREEMSG(mp, "Not a T_unitdata_ind *");
			freemsg(mp);
			continue;
		}

		/*
		 * In the future, we'll care about the source information
		 * for purposes of telling varpd for oob invalidation. But for
		 * now, just drop that block.
		 */
		fmp = mp;
		mp = fmp->b_cont;
		freeb(fmp);

		/*
		 * Until we have VXLAN-or-other-decap HW acceleration support
		 * (e.g.  we support NICs that reach into VXLAN-encapsulated
		 * packets and check the inside-VXLAN IP packets' checksums,
		 * or do LSO with VXLAN), we should clear any HW-accelerated-
		 * performed bits.
		 */
		DB_CKSUMFLAGS(mp) = 0;

		/*
		 * Decap and deliver.
		 */
		bzero(&infop, sizeof (ovep_encap_info_t));
		ret = mux->omux_plugin->ovp_ops->ovpo_decap(NULL, mp, &infop);
		if (ret != 0) {
			OVERLAY_FREEMSG(mp, "decap failed");
			freemsg(mp);
			continue;
		}
		if (MBLKL(mp) > infop.ovdi_hdr_size) {
			mp->b_rptr += infop.ovdi_hdr_size;
		} else {
			while (infop.ovdi_hdr_size != 0) {
				size_t rem, blkl;

				if (mp == NULL)
					break;

				blkl = MBLKL(mp);
				rem = MIN(infop.ovdi_hdr_size, blkl);
				infop.ovdi_hdr_size -= rem;
				mp->b_rptr += rem;
				if (rem == blkl) {
					fmp = mp;
					mp = fmp->b_cont;
					fmp->b_cont = NULL;
					OVERLAY_FREEMSG(mp,
					    "freed a fmp block");
					freemsg(fmp);
				}
			}
			if (mp == NULL) {
				OVERLAY_FREEMSG(mp, "freed it all...");
				continue;
			}
		}


		od.odd_vid = infop.ovdi_id;
		mutex_enter(&mux->omux_lock);
		odd = avl_find(&mux->omux_devices, &od, NULL);
		if (odd == NULL) {
			mutex_exit(&mux->omux_lock);
			OVERLAY_FREEMSG(mp, "no matching vid");
			freemsg(mp);
			continue;
		}
		mutex_enter(&odd->odd_lock);
		if ((odd->odd_flags & OVERLAY_F_MDDROP) ||
		    !(odd->odd_flags & OVERLAY_F_IN_MUX)) {
			mutex_exit(&odd->odd_lock);
			mutex_exit(&mux->omux_lock);
			OVERLAY_FREEMSG(mp, "dev dropped");
			freemsg(mp);
			continue;
		}
		overlay_io_start(odd, OVERLAY_F_IN_RX);
		mutex_exit(&odd->odd_lock);
		mutex_exit(&mux->omux_lock);

		mac_rx(odd->odd_mh, NULL, mp);

		mutex_enter(&odd->odd_lock);
		overlay_io_done(odd, OVERLAY_F_IN_RX);
		mutex_exit(&odd->odd_lock);
	}

	return (B_TRUE);
}

/*
 * Register a given device with a socket backend. If no such device socket
 * exists, create a new one.
 */
overlay_mux_t *
overlay_mux_open(overlay_plugin_t *opp, int domain, int family, int protocol,
    struct sockaddr *addr, socklen_t len, int *errp)
{
	int err;
	overlay_mux_t *mux;
	ksocket_t ksock;

	if (errp == NULL)
		errp = &err;

	mutex_enter(&overlay_mux_lock);
	for (mux = list_head(&overlay_mux_list); mux != NULL;
	    mux = list_next(&overlay_mux_list, mux)) {
		if (domain == mux->omux_domain &&
		    family == mux->omux_family &&
		    protocol == mux->omux_protocol &&
		    len == mux->omux_alen &&
		    bcmp(addr, mux->omux_addr, len) == 0) {

			if (opp != mux->omux_plugin) {
				*errp = EEXIST;
				return (NULL);
			}

			mutex_enter(&mux->omux_lock);
			mux->omux_count++;
			mutex_exit(&mux->omux_lock);
			mutex_exit(&overlay_mux_lock);
			*errp = 0;
			return (mux);
		}
	}

	/*
	 * Today we aren't zone-aware and only exist in the global zone. When we
	 * allow for things to exist in the non-global zone, we'll want to use a
	 * credential that's actually specific to the zone.
	 */
	*errp = ksocket_socket(&ksock, domain, family, protocol, KSOCKET_SLEEP,
	    kcred);
	if (*errp != 0) {
		mutex_exit(&overlay_mux_lock);
		return (NULL);
	}

	*errp = ksocket_bind(ksock, addr, len, kcred);
	if (*errp != 0) {
		mutex_exit(&overlay_mux_lock);
		ksocket_close(ksock, kcred);
		return (NULL);
	}

	/*
	 * Ask our lower layer to optionally toggle anything they need on this
	 * socket. Because a socket is owned by a single type of plugin, we can
	 * then ask it to perform any additional socket set up it'd like to do.
	 */
	if (opp->ovp_ops->ovpo_sockopt != NULL &&
	    (*errp = opp->ovp_ops->ovpo_sockopt(ksock)) != 0) {
		mutex_exit(&overlay_mux_lock);
		ksocket_close(ksock, kcred);
		return (NULL);
	}

	mux = kmem_alloc(sizeof (overlay_mux_t), KM_SLEEP);
	list_link_init(&mux->omux_lnode);
	mux->omux_ksock = ksock;
	mux->omux_plugin = opp;
	mux->omux_domain = domain;
	mux->omux_family = family;
	mux->omux_protocol = protocol;
	mux->omux_addr = kmem_alloc(len, KM_SLEEP);
	bcopy(addr, mux->omux_addr, len);
	mux->omux_alen = len;
	mux->omux_count = 1;
	avl_create(&mux->omux_devices, overlay_mux_comparator,
	    sizeof (overlay_dev_t), offsetof(overlay_dev_t, odd_muxnode));
	mutex_init(&mux->omux_lock, NULL, MUTEX_DRIVER, NULL);


	/* Once this is called, we need to expect to rx data */
	*errp = ksocket_krecv_set(ksock, overlay_mux_recv, mux);
	if (*errp != 0) {
		ksocket_close(ksock, kcred);
		mutex_destroy(&mux->omux_lock);
		avl_destroy(&mux->omux_devices);
		kmem_free(mux->omux_addr, len);
		kmem_free(mux, sizeof (overlay_mux_t));
		return (NULL);
	}

	list_insert_tail(&overlay_mux_list, mux);
	mutex_exit(&overlay_mux_lock);

	*errp = 0;
	return (mux);
}

void
overlay_mux_close(overlay_mux_t *mux)
{
	mutex_enter(&overlay_mux_lock);
	mutex_enter(&mux->omux_lock);
	mux->omux_count--;
	if (mux->omux_count != 0) {
		mutex_exit(&mux->omux_lock);
		mutex_exit(&overlay_mux_lock);
		return;
	}
	list_remove(&overlay_mux_list, mux);
	mutex_exit(&mux->omux_lock);
	mutex_exit(&overlay_mux_lock);

	ksocket_close(mux->omux_ksock, kcred);
	avl_destroy(&mux->omux_devices);
	kmem_free(mux->omux_addr, mux->omux_alen);
	kmem_free(mux, sizeof (overlay_mux_t));
}

void
overlay_mux_add_dev(overlay_mux_t *mux, overlay_dev_t *odd)
{
	mutex_enter(&mux->omux_lock);
	avl_add(&mux->omux_devices, odd);
	mutex_exit(&mux->omux_lock);
}

void
overlay_mux_remove_dev(overlay_mux_t *mux, overlay_dev_t *odd)
{
	mutex_enter(&mux->omux_lock);
	avl_remove(&mux->omux_devices, odd);
	mutex_exit(&mux->omux_lock);
}

int
overlay_mux_tx(overlay_mux_t *mux, struct msghdr *hdr, mblk_t *mp)
{
	int ret;

	/*
	 * It'd be nice to be able to use MSG_MBLK_QUICKRELE, unfortunately,
	 * that isn't actually supported by UDP at this time.
	 */
	ret = ksocket_sendmblk(mux->omux_ksock, hdr, 0, &mp, kcred);
	if (ret != 0)
		freemsg(mp);

	return (ret);
}
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2015 Joyent, Inc.
 */

/*
 * Overlay device encapsulation plugin management
 *
 * For more information, see the big theory statement in
 * uts/common/io/overlay/overlay.c
 */

#include <sys/types.h>
#include <sys/kmem.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/errno.h>
#include <sys/sysmacros.h>
#include <sys/modctl.h>

#include <sys/overlay_impl.h>

static kmem_cache_t *overlay_plugin_cache;
static kmutex_t overlay_plugin_lock;
static list_t overlay_plugin_list;

#define	OVERLAY_MODDIR	"overlay"

/* ARGSUSED */
static int
overlay_plugin_cache_constructor(void *buf, void *arg, int kmflags)
{
	overlay_plugin_t *opp = buf;

	mutex_init(&opp->ovp_mutex, NULL, MUTEX_DRIVER, NULL);
	list_link_init(&opp->ovp_link);

	return (0);
}

/* ARGSUSED */
static void
overlay_plugin_cache_destructor(void *buf, void *arg)
{
	overlay_plugin_t *opp = buf;
	ASSERT(list_link_active(&opp->ovp_link) == 0);
	mutex_destroy(&opp->ovp_mutex);
}

void
overlay_plugin_init(void)
{
	mutex_init(&overlay_plugin_lock, NULL, MUTEX_DRIVER, 0);

	/*
	 * In the future we may want to have a reaper to unload unused modules
	 * to help the kernel be able to reclaim memory.
	 */
	overlay_plugin_cache = kmem_cache_create("overlay_plugin_cache",
	    sizeof (overlay_plugin_t), 0, overlay_plugin_cache_constructor,
	    overlay_plugin_cache_destructor, NULL, NULL, NULL, 0);
	list_create(&overlay_plugin_list, sizeof (overlay_plugin_t),
	    offsetof(overlay_plugin_t, ovp_link));
}

void
overlay_plugin_fini(void)
{
	mutex_enter(&overlay_plugin_lock);
	VERIFY(list_is_empty(&overlay_plugin_list));
	mutex_exit(&overlay_plugin_lock);

	list_destroy(&overlay_plugin_list);
	kmem_cache_destroy(overlay_plugin_cache);
	mutex_destroy(&overlay_plugin_lock);
}

overlay_plugin_register_t *
overlay_plugin_alloc(uint_t version)
{
	overlay_plugin_register_t *ovrp;
	/* Version 1 is the only one that exists */
	if (version != OVEP_VERSION_ONE)
		return (NULL);

	ovrp = kmem_zalloc(sizeof (overlay_plugin_register_t), KM_SLEEP);
	ovrp->ovep_version = version;
	return (ovrp);
}

void
overlay_plugin_free(overlay_plugin_register_t *ovrp)
{
	kmem_free(ovrp, sizeof (overlay_plugin_register_t));
}

int
overlay_plugin_register(overlay_plugin_register_t *ovrp)
{
	overlay_plugin_t *opp, *ipp;

	/* Sanity check parameters of the registration */
	if (ovrp->ovep_version != OVEP_VERSION_ONE)
		return (EINVAL);

	if (ovrp->ovep_name == NULL || ovrp->ovep_ops == NULL)
		return (EINVAL);

	if ((ovrp->ovep_flags & ~(OVEP_F_VLAN_TAG)) != 0)
		return (EINVAL);

	if (ovrp->ovep_id_size < 1)
		return (EINVAL);

	/* Don't support anything that has an id size larger than 8 bytes */
	if (ovrp->ovep_id_size > 8)
		return (ENOTSUP);

	if (ovrp->ovep_dest == OVERLAY_PLUGIN_D_INVALID)
		return (EINVAL);

	if ((ovrp->ovep_dest & ~OVERLAY_PLUGIN_D_MASK) != 0)
		return (EINVAL);

	if (ovrp->ovep_ops->ovpo_callbacks != 0)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_init == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_fini == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_encap == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_decap == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_socket == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_getprop == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_setprop == NULL)
		return (EINVAL);
	if (ovrp->ovep_ops->ovpo_propinfo == NULL)
		return (EINVAL);


	opp = kmem_cache_alloc(overlay_plugin_cache, KM_SLEEP);
	opp->ovp_active = 0;
	opp->ovp_name = ovrp->ovep_name;
	opp->ovp_ops = ovrp->ovep_ops;
	opp->ovp_props = ovrp->ovep_props;
	opp->ovp_id_size = ovrp->ovep_id_size;
	opp->ovp_flags = ovrp->ovep_flags;
	opp->ovp_dest = ovrp->ovep_dest;

	opp->ovp_nprops = 0;
	if (ovrp->ovep_props != NULL) {
		while (ovrp->ovep_props[opp->ovp_nprops] != NULL) {
			if (strlen(ovrp->ovep_props[opp->ovp_nprops]) >=
			    OVERLAY_PROP_NAMELEN) {
				mutex_exit(&overlay_plugin_lock);
				kmem_cache_free(overlay_plugin_cache, opp);
				return (EINVAL);
			}
			opp->ovp_nprops++;
		}
	}

	mutex_enter(&overlay_plugin_lock);
	for (ipp = list_head(&overlay_plugin_list); ipp != NULL;
	    ipp = list_next(&overlay_plugin_list, ipp)) {
		if (strcmp(ipp->ovp_name, opp->ovp_name) == 0) {
			mutex_exit(&overlay_plugin_lock);
			kmem_cache_free(overlay_plugin_cache, opp);
			return (EEXIST);
		}
	}
	list_insert_tail(&overlay_plugin_list, opp);
	mutex_exit(&overlay_plugin_lock);

	return (0);
}

int
overlay_plugin_unregister(const char *name)
{
	overlay_plugin_t *opp;

	mutex_enter(&overlay_plugin_lock);
	for (opp = list_head(&overlay_plugin_list); opp != NULL;
	    opp = list_next(&overlay_plugin_list, opp)) {
		if (strcmp(opp->ovp_name, name) == 0)
			break;
	}

	if (opp == NULL) {
		mutex_exit(&overlay_plugin_lock);
		return (ENOENT);
	}

	mutex_enter(&opp->ovp_mutex);
	if (opp->ovp_active > 0) {
		mutex_exit(&opp->ovp_mutex);
		mutex_exit(&overlay_plugin_lock);
		return (EBUSY);
	}
	mutex_exit(&opp->ovp_mutex);

	list_remove(&overlay_plugin_list, opp);
	mutex_exit(&overlay_plugin_lock);

	kmem_cache_free(overlay_plugin_cache, opp);
	return (0);
}

overlay_plugin_t *
overlay_plugin_lookup(const char *name)
{
	overlay_plugin_t *opp;
	boolean_t trymodload = B_FALSE;

	for (;;) {
		mutex_enter(&overlay_plugin_lock);
		for (opp = list_head(&overlay_plugin_list); opp != NULL;
		    opp = list_next(&overlay_plugin_list, opp)) {
			if (strcmp(name, opp->ovp_name) == 0) {
				mutex_enter(&opp->ovp_mutex);
				opp->ovp_active++;
				mutex_exit(&opp->ovp_mutex);
				mutex_exit(&overlay_plugin_lock);
				return (opp);
			}
		}
		mutex_exit(&overlay_plugin_lock);

		if (trymodload == B_TRUE)
			return (NULL);

		/*
		 * If we didn't find it, it may still exist, but just not have
		 * been a loaded module. In that case, we'll do one attempt to
		 * load it.
		 */
		if (modload(OVERLAY_MODDIR, (char *)name) == -1)
			return (NULL);
		trymodload = B_TRUE;
	}

}

void
overlay_plugin_rele(overlay_plugin_t *opp)
{
	mutex_enter(&opp->ovp_mutex);
	ASSERT(opp->ovp_active > 0);
	opp->ovp_active--;
	mutex_exit(&opp->ovp_mutex);
}

void
overlay_plugin_walk(overlay_plugin_walk_f func, void *arg)
{
	overlay_plugin_t *opp;
	mutex_enter(&overlay_plugin_lock);
	for (opp = list_head(&overlay_plugin_list); opp != NULL;
	    opp = list_next(&overlay_plugin_list, opp)) {
		if (func(opp, arg) != 0) {
			mutex_exit(&overlay_plugin_lock);
			return;
		}
	}
	mutex_exit(&overlay_plugin_lock);
}
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2015, Joyent, Inc.
 */

/*
 * Routines for manipulating property information structures.
 *
 * For more information, see the big theory statement in
 * uts/common/io/overlay/overlay.c
 */

#include <sys/overlay_impl.h>

void
overlay_prop_init(overlay_prop_handle_t phdl)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	mac_propval_range_t *rangep = (mac_propval_range_t *)infop->oipi_poss;

	infop->oipi_posssize = sizeof (mac_propval_range_t);
	bzero(rangep, sizeof (mac_propval_range_t));
}

void
overlay_prop_set_name(overlay_prop_handle_t phdl, const char *name)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	(void) strlcpy(infop->oipi_name, name, OVERLAY_PROP_NAMELEN);
}

void
overlay_prop_set_prot(overlay_prop_handle_t phdl, overlay_prop_prot_t prot)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	infop->oipi_prot = prot;
}

void
overlay_prop_set_type(overlay_prop_handle_t phdl, overlay_prop_type_t type)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	infop->oipi_type = type;
}

int
overlay_prop_set_default(overlay_prop_handle_t phdl, void *def, ssize_t len)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;

	if (len > OVERLAY_PROP_SIZEMAX)
		return (E2BIG);

	if (len < 0)
		return (EOVERFLOW);

	bcopy(def, infop->oipi_default, len);
	infop->oipi_defsize = (uint32_t)len;

	return (0);
}

void
overlay_prop_set_nodefault(overlay_prop_handle_t phdl)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	infop->oipi_default[0] = '\0';
	infop->oipi_defsize = 0;
}

void
overlay_prop_set_range_uint32(overlay_prop_handle_t phdl, uint32_t min,
    uint32_t max)
{
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	mac_propval_range_t *rangep = (mac_propval_range_t *)infop->oipi_poss;

	if (rangep->mpr_count != 0 && rangep->mpr_type != MAC_PROPVAL_UINT32)
		return;

	if (infop->oipi_posssize + sizeof (mac_propval_uint32_range_t) >
	    sizeof (infop->oipi_poss))
		return;

	infop->oipi_posssize += sizeof (mac_propval_uint32_range_t);
	rangep->mpr_count++;
	rangep->mpr_type = MAC_PROPVAL_UINT32;
	rangep->u.mpr_uint32[rangep->mpr_count-1].mpur_min = min;
	rangep->u.mpr_uint32[rangep->mpr_count-1].mpur_max = max;
}

void
overlay_prop_set_range_str(overlay_prop_handle_t phdl, const char *str)
{
	size_t len = strlen(str) + 1; /* Account for a null terminator */
	overlay_ioc_propinfo_t *infop = (overlay_ioc_propinfo_t *)phdl;
	mac_propval_range_t *rangep = (mac_propval_range_t *)infop->oipi_poss;
	mac_propval_str_range_t *pstr = &rangep->u.mpr_str;

	if (rangep->mpr_count != 0 && rangep->mpr_type != MAC_PROPVAL_STR)
		return;

	if (infop->oipi_posssize + len > sizeof (infop->oipi_poss))
		return;

	rangep->mpr_count++;
	rangep->mpr_type = MAC_PROPVAL_STR;
	strlcpy((char *)&pstr->mpur_data[pstr->mpur_nextbyte], str,
	    sizeof (infop->oipi_poss) - infop->oipi_posssize);
	pstr->mpur_nextbyte += len;
	infop->oipi_posssize += len;
}
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2016 Joyent, Inc.
 * Copyright 2022 MNX Cloud, Inc.
 */

/*
 * Overlay device target cache management
 *
 * For more information, see the big theory statement in
 * uts/common/io/overlay/overlay.c
 */

#include <sys/types.h>
#include <sys/ethernet.h>
#include <sys/kmem.h>
#include <sys/policy.h>
#include <sys/sysmacros.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/strsubr.h>
#include <sys/mac_provider.h>
#include <sys/mac_client.h>
#include <sys/mac_client_priv.h>
#include <sys/vlan.h>
#include <sys/crc32.h>
#include <sys/cred.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

#include <sys/overlay_impl.h>
#include <sys/sdt.h>

/*
 * This is total straw man, but at least it's a prime number. Here we're
 * going to have to go through and do a lot of evaluation and understanding as
 * to how these target caches should grow and shrink, as well as, memory
 * pressure and evictions. This just gives us a starting point that'll be 'good
 * enough', until it's not.
 */
#define	OVERLAY_HSIZE	823

/*
 * We use this data structure to keep track of what requests have been actively
 * allocated to a given instance so we know what to put back on the pending
 * list.
 */
typedef struct overlay_target_hdl {
	minor_t oth_minor;		/* RO */
	zoneid_t oth_zoneid;		/* RO */
	int oth_oflags;			/* RO */
	list_node_t oth_link;		/* overlay_target_lock */
	kmutex_t oth_lock;
	list_t	oth_outstanding;	/* oth_lock */
} overlay_target_hdl_t;

typedef int (*overlay_target_copyin_f)(const void *, void **, size_t *, int);
typedef int (*overlay_target_ioctl_f)(overlay_target_hdl_t *, void *);
typedef int (*overlay_target_copyout_f)(void *, void *, size_t, int);

typedef struct overlay_target_ioctl {
	int		oti_cmd;	/* ioctl id */
	boolean_t	oti_write;	/* ioctl requires FWRITE */
	boolean_t	oti_ncopyout;	/* copyout data? */
	overlay_target_copyin_f oti_copyin;	/* copyin func */
	overlay_target_ioctl_f oti_func; /* function to call */
	overlay_target_copyout_f oti_copyout;	/* copyin func */
	size_t		oti_size;	/* size of user level structure */
} overlay_target_ioctl_t;

static kmem_cache_t *overlay_target_cache;
static kmem_cache_t *overlay_entry_cache;
static id_space_t *overlay_thdl_idspace;
static void *overlay_thdl_state;

/*
 * When we support overlay devices in the NGZ, then all of these need to become
 * zone aware, by plugging into the netstack engine and becoming per-netstack
 * data.
 */
static list_t overlay_thdl_list;
static kmutex_t overlay_target_lock;
static kcondvar_t overlay_target_condvar;
static list_t overlay_target_list;
static boolean_t overlay_target_excl;

/*
 * Outstanding data per hash table entry.
 */
static int overlay_ent_size = 128 * 1024;

/* ARGSUSED */
static int
overlay_target_cache_constructor(void *buf, void *arg, int kmflgs)
{
	overlay_target_t *ott = buf;

	mutex_init(&ott->ott_lock, NULL, MUTEX_DRIVER, NULL);
	cv_init(&ott->ott_cond, NULL, CV_DRIVER, NULL);
	return (0);
}

/* ARGSUSED */
static void
overlay_target_cache_destructor(void *buf, void *arg)
{
	overlay_target_t *ott = buf;

	cv_destroy(&ott->ott_cond);
	mutex_destroy(&ott->ott_lock);
}

/* ARGSUSED */
static int
overlay_entry_cache_constructor(void *buf, void *arg, int kmflgs)
{
	overlay_target_entry_t *ote = buf;

	bzero(ote, sizeof (overlay_target_entry_t));
	mutex_init(&ote->ote_lock, NULL, MUTEX_DRIVER, NULL);
	return (0);
}

/* ARGSUSED */
static void
overlay_entry_cache_destructor(void *buf, void *arg)
{
	overlay_target_entry_t *ote = buf;

	mutex_destroy(&ote->ote_lock);
}

static uint64_t
overlay_mac_hash(const void *v)
{
	uint32_t crc;
	CRC32(crc, v, ETHERADDRL, -1U, crc32_table);
	return (crc);
}

static int
overlay_mac_cmp(const void *a, const void *b)
{
	return (bcmp(a, b, ETHERADDRL));
}

/* ARGSUSED */
static void
overlay_target_entry_dtor(void *arg)
{
	overlay_target_entry_t *ote = arg;

	ote->ote_flags = 0;
	bzero(ote->ote_addr, ETHERADDRL);
	ote->ote_ott = NULL;
	ote->ote_odd = NULL;
	freemsgchain(ote->ote_chead);
	ote->ote_chead = ote->ote_ctail = NULL;
	ote->ote_mbsize = 0;
	ote->ote_vtime = 0;
	kmem_cache_free(overlay_entry_cache, ote);
}

static int
overlay_mac_avl(const void *a, const void *b)
{
	int i;
	const overlay_target_entry_t *l, *r;
	l = a;
	r = b;

	for (i = 0; i < ETHERADDRL; i++) {
		if (l->ote_addr[i] > r->ote_addr[i])
			return (1);
		else if (l->ote_addr[i] < r->ote_addr[i])
			return (-1);
	}

	return (0);
}

void
overlay_target_init(void)
{
	int ret;
	ret = ddi_soft_state_init(&overlay_thdl_state,
	    sizeof (overlay_target_hdl_t), 1);
	VERIFY(ret == 0);
	overlay_target_cache = kmem_cache_create("overlay_target",
	    sizeof (overlay_target_t), 0, overlay_target_cache_constructor,
	    overlay_target_cache_destructor, NULL, NULL, NULL, 0);
	overlay_entry_cache = kmem_cache_create("overlay_entry",
	    sizeof (overlay_target_entry_t), 0, overlay_entry_cache_constructor,
	    overlay_entry_cache_destructor, NULL, NULL, NULL, 0);
	mutex_init(&overlay_target_lock, NULL, MUTEX_DRIVER, NULL);
	cv_init(&overlay_target_condvar, NULL, CV_DRIVER, NULL);
	list_create(&overlay_target_list, sizeof (overlay_target_entry_t),
	    offsetof(overlay_target_entry_t, ote_qlink));
	list_create(&overlay_thdl_list, sizeof (overlay_target_hdl_t),
	    offsetof(overlay_target_hdl_t, oth_link));
	overlay_thdl_idspace = id_space_create("overlay_target_minors",
	    1, INT32_MAX);
}

void
overlay_target_fini(void)
{
	id_space_destroy(overlay_thdl_idspace);
	list_destroy(&overlay_thdl_list);
	list_destroy(&overlay_target_list);
	cv_destroy(&overlay_target_condvar);
	mutex_destroy(&overlay_target_lock);
	kmem_cache_destroy(overlay_entry_cache);
	kmem_cache_destroy(overlay_target_cache);
	ddi_soft_state_fini(&overlay_thdl_state);
}

void
overlay_target_free(overlay_dev_t *odd)
{
	if (odd->odd_target == NULL)
		return;

	if (odd->odd_target->ott_mode == OVERLAY_TARGET_DYNAMIC) {
		refhash_t *rp = odd->odd_target->ott_u.ott_dyn.ott_dhash;
		avl_tree_t *ap = &odd->odd_target->ott_u.ott_dyn.ott_tree;
		overlay_target_entry_t *ote;

		/*
		 * Our AVL tree and hashtable contain the same elements,
		 * therefore we should just remove it from the tree, but then
		 * delete the entries when we remove them from the hash table
		 * (which happens through the refhash dtor).
		 */
		while ((ote = avl_first(ap)) != NULL)
			avl_remove(ap, ote);

		avl_destroy(ap);
		for (ote = refhash_first(rp); ote != NULL;
		    ote = refhash_next(rp, ote)) {
			refhash_remove(rp, ote);
		}
		refhash_destroy(rp);
	}

	ASSERT(odd->odd_target->ott_ocount == 0);
	kmem_cache_free(overlay_target_cache, odd->odd_target);
}

int
overlay_target_busy()
{
	int ret;

	mutex_enter(&overlay_target_lock);
	ret = !list_is_empty(&overlay_thdl_list);
	mutex_exit(&overlay_target_lock);

	return (ret);
}

static void
overlay_target_queue(overlay_target_entry_t *entry)
{
	mutex_enter(&overlay_target_lock);
	mutex_enter(&entry->ote_ott->ott_lock);
	if (entry->ote_ott->ott_flags & OVERLAY_T_TEARDOWN) {
		mutex_exit(&entry->ote_ott->ott_lock);
		mutex_exit(&overlay_target_lock);
		return;
	}
	entry->ote_ott->ott_ocount++;
	mutex_exit(&entry->ote_ott->ott_lock);
	list_insert_tail(&overlay_target_list, entry);
	cv_signal(&overlay_target_condvar);
	mutex_exit(&overlay_target_lock);
}

void
overlay_target_quiesce(overlay_target_t *ott)
{
	if (ott == NULL)
		return;
	mutex_enter(&ott->ott_lock);
	ott->ott_flags |= OVERLAY_T_TEARDOWN;
	while (ott->ott_ocount != 0)
		cv_wait(&ott->ott_cond, &ott->ott_lock);
	mutex_exit(&ott->ott_lock);
}

/*
 * This functions assumes that the destination mode is OVERLAY_PLUGIN_D_IP |
 * OVERLAY_PLUGIN_D_PORT. As we don't have an implementation of anything else at
 * this time, say for NVGRE, we drop all packets that mcuh this.
 */
int
overlay_target_lookup(overlay_dev_t *odd, mblk_t *mp, struct sockaddr *sock,
    socklen_t *slenp)
{
	int ret;
	struct sockaddr_in6 *v6;
	overlay_target_t *ott;
	mac_header_info_t mhi;
	overlay_target_entry_t *entry;

	ASSERT(odd->odd_target != NULL);

	/*
	 * At this point, the overlay device is in a mux which means that it's
	 * been activated. At this point, parts of the target, such as the mode
	 * and the destination are now read-only and we don't have to worry
	 * about synchronization for them.
	 */
	ott = odd->odd_target;
	if (ott->ott_dest != (OVERLAY_PLUGIN_D_IP | OVERLAY_PLUGIN_D_PORT))
		return (OVERLAY_TARGET_DROP);

	v6 = (struct sockaddr_in6 *)sock;
	bzero(v6, sizeof (struct sockaddr_in6));
	v6->sin6_family = AF_INET6;

	if (ott->ott_mode == OVERLAY_TARGET_POINT) {
		mutex_enter(&ott->ott_lock);
		bcopy(&ott->ott_u.ott_point.otp_ip, &v6->sin6_addr,
		    sizeof (struct in6_addr));
		v6->sin6_port = htons(ott->ott_u.ott_point.otp_port);
		mutex_exit(&ott->ott_lock);
		*slenp = sizeof (struct sockaddr_in6);

		return (OVERLAY_TARGET_OK);
	}

	ASSERT(ott->ott_mode == OVERLAY_TARGET_DYNAMIC);

	/*
	 * Note we only want the MAC address here, therefore we won't bother
	 * using mac_vlan_header_info(). If any caller needs the vlan info at
	 * this point, this should change to a call to mac_vlan_header_info().
	 */
	if (mac_header_info(odd->odd_mh, mp, &mhi) != 0)
		return (OVERLAY_TARGET_DROP);
	mutex_enter(&ott->ott_lock);
	entry = refhash_lookup(ott->ott_u.ott_dyn.ott_dhash,
	    mhi.mhi_daddr);
	if (entry == NULL) {
		entry = kmem_cache_alloc(overlay_entry_cache, KM_NOSLEEP_LAZY);
		if (entry == NULL) {
			mutex_exit(&ott->ott_lock);
			return (OVERLAY_TARGET_DROP);
		}
		bcopy(mhi.mhi_daddr, entry->ote_addr, ETHERADDRL);
		entry->ote_chead = entry->ote_ctail = mp;
		entry->ote_mbsize = msgsize(mp);
		entry->ote_flags |= OVERLAY_ENTRY_F_PENDING;
		entry->ote_ott = ott;
		entry->ote_odd = odd;
		refhash_insert(ott->ott_u.ott_dyn.ott_dhash, entry);
		avl_add(&ott->ott_u.ott_dyn.ott_tree, entry);
		mutex_exit(&ott->ott_lock);
		overlay_target_queue(entry);
		return (OVERLAY_TARGET_ASYNC);
	}
	refhash_hold(ott->ott_u.ott_dyn.ott_dhash, entry);
	mutex_exit(&ott->ott_lock);

	mutex_enter(&entry->ote_lock);
	if (entry->ote_flags & OVERLAY_ENTRY_F_DROP) {
		ret = OVERLAY_TARGET_DROP;
	} else if (entry->ote_flags & OVERLAY_ENTRY_F_VALID) {
		bcopy(&entry->ote_dest.otp_ip, &v6->sin6_addr,
		    sizeof (struct in6_addr));
		v6->sin6_port = htons(entry->ote_dest.otp_port);
		*slenp = sizeof (struct sockaddr_in6);
		ret = OVERLAY_TARGET_OK;
	} else {
		size_t mlen = msgsize(mp);

		if (mlen + entry->ote_mbsize > overlay_ent_size) {
			ret = OVERLAY_TARGET_DROP;
		} else {
			if (entry->ote_ctail != NULL) {
				ASSERT(entry->ote_ctail->b_next ==
				    NULL);
				entry->ote_ctail->b_next = mp;
				entry->ote_ctail = mp;
			} else {
				entry->ote_chead = mp;
				entry->ote_ctail = mp;
			}
			entry->ote_mbsize += mlen;
			if ((entry->ote_flags &
			    OVERLAY_ENTRY_F_PENDING) == 0) {
				entry->ote_flags |=
				    OVERLAY_ENTRY_F_PENDING;
				overlay_target_queue(entry);
			}
			ret = OVERLAY_TARGET_ASYNC;
		}
	}
	mutex_exit(&entry->ote_lock);

	mutex_enter(&ott->ott_lock);
	refhash_rele(ott->ott_u.ott_dyn.ott_dhash, entry);
	mutex_exit(&ott->ott_lock);

	return (ret);
}

/* ARGSUSED */
static int
overlay_target_info(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_targ_info_t *oti = arg;

	odd = overlay_hold_by_dlid(oti->oti_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	oti->oti_flags = 0;
	oti->oti_needs = odd->odd_plugin->ovp_dest;
	if (odd->odd_flags & OVERLAY_F_DEGRADED)
		oti->oti_flags |= OVERLAY_TARG_INFO_F_DEGRADED;
	if (odd->odd_flags & OVERLAY_F_ACTIVATED)
		oti->oti_flags |= OVERLAY_TARG_INFO_F_ACTIVE;
	oti->oti_vnetid = odd->odd_vid;
	mutex_exit(&odd->odd_lock);
	overlay_hold_rele(odd);
	return (0);
}

/* ARGSUSED */
static int
overlay_target_associate(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_target_t *ott;
	overlay_targ_associate_t *ota = arg;

	odd = overlay_hold_by_dlid(ota->ota_linkid);
	if (odd == NULL)
		return (ENOENT);

	if (ota->ota_id == 0) {
		overlay_hold_rele(odd);
		return (EINVAL);
	}

	if (ota->ota_mode != OVERLAY_TARGET_POINT &&
	    ota->ota_mode != OVERLAY_TARGET_DYNAMIC) {
		overlay_hold_rele(odd);
		return (EINVAL);
	}

	if (ota->ota_provides != odd->odd_plugin->ovp_dest) {
		overlay_hold_rele(odd);
		return (EINVAL);
	}

	if (ota->ota_mode == OVERLAY_TARGET_POINT) {
		if (ota->ota_provides & OVERLAY_PLUGIN_D_IP) {
			if (IN6_IS_ADDR_UNSPECIFIED(&ota->ota_point.otp_ip) ||
			    IN6_IS_ADDR_V4COMPAT(&ota->ota_point.otp_ip) ||
			    IN6_IS_ADDR_V4MAPPED_ANY(&ota->ota_point.otp_ip)) {
				overlay_hold_rele(odd);
				return (EINVAL);
			}
		}

		if (ota->ota_provides & OVERLAY_PLUGIN_D_PORT) {
			if (ota->ota_point.otp_port == 0) {
				overlay_hold_rele(odd);
				return (EINVAL);
			}
		}
	}

	ott = kmem_cache_alloc(overlay_target_cache, KM_SLEEP);
	ott->ott_flags = 0;
	ott->ott_ocount = 0;
	ott->ott_mode = ota->ota_mode;
	ott->ott_dest = ota->ota_provides;
	ott->ott_id = ota->ota_id;

	if (ott->ott_mode == OVERLAY_TARGET_POINT) {
		bcopy(&ota->ota_point, &ott->ott_u.ott_point,
		    sizeof (overlay_target_point_t));
	} else {
		ott->ott_u.ott_dyn.ott_dhash = refhash_create(OVERLAY_HSIZE,
		    overlay_mac_hash, overlay_mac_cmp,
		    overlay_target_entry_dtor, sizeof (overlay_target_entry_t),
		    offsetof(overlay_target_entry_t, ote_reflink),
		    offsetof(overlay_target_entry_t, ote_addr), KM_SLEEP);
		avl_create(&ott->ott_u.ott_dyn.ott_tree, overlay_mac_avl,
		    sizeof (overlay_target_entry_t),
		    offsetof(overlay_target_entry_t, ote_avllink));
	}
	mutex_enter(&odd->odd_lock);
	if (odd->odd_flags & OVERLAY_F_VARPD) {
		mutex_exit(&odd->odd_lock);
		kmem_cache_free(overlay_target_cache, ott);
		overlay_hold_rele(odd);
		return (EEXIST);
	}

	odd->odd_flags |= OVERLAY_F_VARPD;
	odd->odd_target = ott;
	mutex_exit(&odd->odd_lock);

	overlay_hold_rele(odd);


	return (0);
}


/* ARGSUSED */
static int
overlay_target_degrade(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_targ_degrade_t *otd = arg;

	odd = overlay_hold_by_dlid(otd->otd_linkid);
	if (odd == NULL)
		return (ENOENT);

	overlay_fm_degrade(odd, otd->otd_buf);
	overlay_hold_rele(odd);
	return (0);
}

/* ARGSUSED */
static int
overlay_target_restore(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_targ_id_t *otid = arg;

	odd = overlay_hold_by_dlid(otid->otid_linkid);
	if (odd == NULL)
		return (ENOENT);

	overlay_fm_restore(odd);
	overlay_hold_rele(odd);
	return (0);
}

/* ARGSUSED */
static int
overlay_target_disassociate(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_targ_id_t *otid = arg;

	odd = overlay_hold_by_dlid(otid->otid_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	odd->odd_flags &= ~OVERLAY_F_VARPD;
	mutex_exit(&odd->odd_lock);

	overlay_hold_rele(odd);
	return (0);

}

static int
overlay_target_lookup_request(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_targ_lookup_t *otl = arg;
	overlay_target_entry_t *entry;
	clock_t ret, timeout;
	mac_header_info_t mhi;

	timeout = ddi_get_lbolt() + drv_usectohz(MICROSEC);
again:
	mutex_enter(&overlay_target_lock);
	while (list_is_empty(&overlay_target_list)) {
		ret = cv_timedwait(&overlay_target_condvar,
		    &overlay_target_lock, timeout);
		if (ret == -1) {
			mutex_exit(&overlay_target_lock);
			return (ETIME);
		}
	}
	entry = list_remove_head(&overlay_target_list);
	mutex_exit(&overlay_target_lock);
	mutex_enter(&entry->ote_lock);
	if (entry->ote_flags & OVERLAY_ENTRY_F_VALID) {
		ASSERT(entry->ote_chead == NULL);
		mutex_exit(&entry->ote_lock);
		goto again;
	}
	ASSERT(entry->ote_chead != NULL);

	/*
	 * If we have a bogon that doesn't have a valid mac header, drop it and
	 * try again.
	 */
	if (mac_vlan_header_info(entry->ote_odd->odd_mh, entry->ote_chead,
	    &mhi) != 0) {
		boolean_t queue = B_FALSE;
		mblk_t *mp = entry->ote_chead;
		entry->ote_chead = mp->b_next;
		mp->b_next = NULL;
		if (entry->ote_ctail == mp)
			entry->ote_ctail = entry->ote_chead;
		entry->ote_mbsize -= msgsize(mp);
		if (entry->ote_chead != NULL)
			queue = B_TRUE;
		mutex_exit(&entry->ote_lock);
		if (queue == B_TRUE)
			overlay_target_queue(entry);
		freemsg(mp);
		goto again;
	}

	otl->otl_dlid = entry->ote_odd->odd_linkid;
	otl->otl_reqid = (uintptr_t)entry;
	otl->otl_varpdid = entry->ote_ott->ott_id;
	otl->otl_vnetid = entry->ote_odd->odd_vid;

	otl->otl_hdrsize = mhi.mhi_hdrsize;
	otl->otl_pktsize = msgsize(entry->ote_chead) - otl->otl_hdrsize;
	bcopy(mhi.mhi_daddr, otl->otl_dstaddr, ETHERADDRL);
	bcopy(mhi.mhi_saddr, otl->otl_srcaddr, ETHERADDRL);
	otl->otl_dsttype = mhi.mhi_dsttype;
	otl->otl_sap = mhi.mhi_bindsap;
	otl->otl_vlan = VLAN_ID(mhi.mhi_tci);
	mutex_exit(&entry->ote_lock);

	mutex_enter(&thdl->oth_lock);
	list_insert_tail(&thdl->oth_outstanding, entry);
	mutex_exit(&thdl->oth_lock);

	return (0);
}

static int
overlay_target_lookup_respond(overlay_target_hdl_t *thdl, void *arg)
{
	const overlay_targ_resp_t *otr = arg;
	overlay_target_entry_t *entry;
	mblk_t *mp;

	mutex_enter(&thdl->oth_lock);
	for (entry = list_head(&thdl->oth_outstanding); entry != NULL;
	    entry = list_next(&thdl->oth_outstanding, entry)) {
		if ((uintptr_t)entry == otr->otr_reqid)
			break;
	}

	if (entry == NULL) {
		mutex_exit(&thdl->oth_lock);
		return (EINVAL);
	}
	list_remove(&thdl->oth_outstanding, entry);
	mutex_exit(&thdl->oth_lock);

	mutex_enter(&entry->ote_lock);
	bcopy(&otr->otr_answer, &entry->ote_dest,
	    sizeof (overlay_target_point_t));
	entry->ote_flags &= ~OVERLAY_ENTRY_F_PENDING;
	entry->ote_flags |= OVERLAY_ENTRY_F_VALID;
	mp = entry->ote_chead;
	entry->ote_chead = NULL;
	entry->ote_ctail = NULL;
	entry->ote_mbsize = 0;
	entry->ote_vtime = gethrtime();
	mutex_exit(&entry->ote_lock);

	/*
	 * For now do an in-situ drain.
	 */
	mp = overlay_m_tx(entry->ote_odd, mp);
	freemsgchain(mp);

	mutex_enter(&entry->ote_ott->ott_lock);
	entry->ote_ott->ott_ocount--;
	cv_signal(&entry->ote_ott->ott_cond);
	mutex_exit(&entry->ote_ott->ott_lock);

	return (0);
}

static int
overlay_target_lookup_drop(overlay_target_hdl_t *thdl, void *arg)
{
	const overlay_targ_resp_t *otr = arg;
	overlay_target_entry_t *entry;
	mblk_t *mp;
	boolean_t queue = B_FALSE;

	mutex_enter(&thdl->oth_lock);
	for (entry = list_head(&thdl->oth_outstanding); entry != NULL;
	    entry = list_next(&thdl->oth_outstanding, entry)) {
		if ((uintptr_t)entry == otr->otr_reqid)
			break;
	}

	if (entry == NULL) {
		mutex_exit(&thdl->oth_lock);
		return (EINVAL);
	}
	list_remove(&thdl->oth_outstanding, entry);
	mutex_exit(&thdl->oth_lock);

	mutex_enter(&entry->ote_lock);

	/* Safeguard against a confused varpd */
	if (entry->ote_flags & OVERLAY_ENTRY_F_VALID) {
		entry->ote_flags &= ~OVERLAY_ENTRY_F_PENDING;
		DTRACE_PROBE1(overlay__target__valid__drop,
		    overlay_target_entry_t *, entry);
		mutex_exit(&entry->ote_lock);
		goto done;
	}

	mp = entry->ote_chead;
	if (mp != NULL) {
		entry->ote_chead = mp->b_next;
		mp->b_next = NULL;
		if (entry->ote_ctail == mp)
			entry->ote_ctail = entry->ote_chead;
		entry->ote_mbsize -= msgsize(mp);
	}
	if (entry->ote_chead != NULL) {
		queue = B_TRUE;
		entry->ote_flags |= OVERLAY_ENTRY_F_PENDING;
	} else {
		entry->ote_flags &= ~OVERLAY_ENTRY_F_PENDING;
	}
	mutex_exit(&entry->ote_lock);

	if (queue == B_TRUE)
		overlay_target_queue(entry);
	freemsg(mp);

done:
	mutex_enter(&entry->ote_ott->ott_lock);
	entry->ote_ott->ott_ocount--;
	cv_signal(&entry->ote_ott->ott_cond);
	mutex_exit(&entry->ote_ott->ott_lock);

	return (0);
}

/* ARGSUSED */
static int
overlay_target_pkt_copyin(const void *ubuf, void **outp, size_t *bsize,
    int flags)
{
	overlay_targ_pkt_t *pkt;
	overlay_targ_pkt32_t *pkt32;

	pkt = kmem_alloc(sizeof (overlay_targ_pkt_t), KM_SLEEP);
	*outp = pkt;
	*bsize = sizeof (overlay_targ_pkt_t);
	if (ddi_model_convert_from(flags & FMODELS) == DDI_MODEL_ILP32) {
		uintptr_t addr;

		if (ddi_copyin(ubuf, pkt, sizeof (overlay_targ_pkt32_t),
		    flags & FKIOCTL) != 0) {
			kmem_free(pkt, *bsize);
			return (EFAULT);
		}
		pkt32 = (overlay_targ_pkt32_t *)pkt;
		addr = pkt32->otp_buf;
		pkt->otp_buf = (void *)addr;
	} else {
		if (ddi_copyin(ubuf, pkt, *bsize, flags & FKIOCTL) != 0) {
			kmem_free(pkt, *bsize);
			return (EFAULT);
		}
	}
	return (0);
}

static int
overlay_target_pkt_copyout(void *ubuf, void *buf, size_t bufsize,
    int flags)
{
	if (ddi_model_convert_from(flags & FMODELS) == DDI_MODEL_ILP32) {
		overlay_targ_pkt_t *pkt = buf;
		overlay_targ_pkt32_t *pkt32 = buf;
		uintptr_t addr = (uintptr_t)pkt->otp_buf;
		pkt32->otp_buf = (caddr32_t)addr;
		if (ddi_copyout(buf, ubuf, sizeof (overlay_targ_pkt32_t),
		    flags & FKIOCTL) != 0)
			return (EFAULT);
	} else {
		if (ddi_copyout(buf, ubuf, bufsize, flags & FKIOCTL) != 0)
			return (EFAULT);
	}
	return (0);
}

static int
overlay_target_packet(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_targ_pkt_t *pkt = arg;
	overlay_target_entry_t *entry;
	mblk_t *mp;
	size_t mlen;
	size_t boff;

	mutex_enter(&thdl->oth_lock);
	for (entry = list_head(&thdl->oth_outstanding); entry != NULL;
	    entry = list_next(&thdl->oth_outstanding, entry)) {
		if ((uintptr_t)entry == pkt->otp_reqid)
			break;
	}

	if (entry == NULL) {
		mutex_exit(&thdl->oth_lock);
		return (EINVAL);
	}
	mutex_enter(&entry->ote_lock);
	mutex_exit(&thdl->oth_lock);
	mp = entry->ote_chead;
	/* Protect against a rogue varpd */
	if (mp == NULL) {
		mutex_exit(&entry->ote_lock);
		return (EINVAL);
	}
	mlen = MIN(msgsize(mp), pkt->otp_size);
	pkt->otp_size = mlen;
	boff = 0;
	while (mlen > 0) {
		size_t wlen = MIN(MBLKL(mp), mlen);
		if (ddi_copyout(mp->b_rptr,
		    (void *)((uintptr_t)pkt->otp_buf + boff),
		    wlen, 0) != 0) {
			mutex_exit(&entry->ote_lock);
			return (EFAULT);
		}
		mlen -= wlen;
		boff += wlen;
		mp = mp->b_cont;
	}
	mutex_exit(&entry->ote_lock);
	return (0);
}

static int
overlay_target_inject(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_targ_pkt_t *pkt = arg;
	overlay_target_entry_t *entry;
	overlay_dev_t *odd;
	mblk_t *mp;

	if (pkt->otp_size > ETHERMAX + VLAN_TAGSZ)
		return (EINVAL);

	mp = allocb(pkt->otp_size, 0);
	if (mp == NULL)
		return (ENOMEM);

	if (ddi_copyin(pkt->otp_buf, mp->b_rptr, pkt->otp_size, 0) != 0) {
		freeb(mp);
		return (EFAULT);
	}
	mp->b_wptr += pkt->otp_size;

	if (pkt->otp_linkid != UINT64_MAX) {
		odd = overlay_hold_by_dlid(pkt->otp_linkid);
		if (odd == NULL) {
			freeb(mp);
			return (ENOENT);
		}
	} else {
		mutex_enter(&thdl->oth_lock);
		for (entry = list_head(&thdl->oth_outstanding); entry != NULL;
		    entry = list_next(&thdl->oth_outstanding, entry)) {
			if ((uintptr_t)entry == pkt->otp_reqid)
				break;
		}

		if (entry == NULL) {
			mutex_exit(&thdl->oth_lock);
			freeb(mp);
			return (ENOENT);
		}
		odd = entry->ote_odd;
		mutex_exit(&thdl->oth_lock);
	}

	mutex_enter(&odd->odd_lock);
	if ((odd->odd_flags & OVERLAY_F_MDDROP) ||
	    !(odd->odd_flags & OVERLAY_F_IN_MUX)) {
		/* Can't do receive... */
		mutex_exit(&odd->odd_lock);
		OVERLAY_FREEMSG(mp, "dev dropped");
		freeb(mp);
		return (EBUSY);
	}
	overlay_io_start(odd, OVERLAY_F_IN_RX);
	mutex_exit(&odd->odd_lock);

	mac_rx(odd->odd_mh, NULL, mp);

	mutex_enter(&odd->odd_lock);
	overlay_io_done(odd, OVERLAY_F_IN_RX);
	mutex_exit(&odd->odd_lock);

	return (0);
}

static int
overlay_target_resend(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_targ_pkt_t *pkt = arg;
	overlay_target_entry_t *entry;
	overlay_dev_t *odd;
	mblk_t *mp;

	if (pkt->otp_size > ETHERMAX + VLAN_TAGSZ)
		return (EINVAL);

	mp = allocb(pkt->otp_size, 0);
	if (mp == NULL)
		return (ENOMEM);

	if (ddi_copyin(pkt->otp_buf, mp->b_rptr, pkt->otp_size, 0) != 0) {
		freeb(mp);
		return (EFAULT);
	}
	mp->b_wptr += pkt->otp_size;

	if (pkt->otp_linkid != UINT64_MAX) {
		odd = overlay_hold_by_dlid(pkt->otp_linkid);
		if (odd == NULL) {
			freeb(mp);
			return (ENOENT);
		}
	} else {
		mutex_enter(&thdl->oth_lock);
		for (entry = list_head(&thdl->oth_outstanding); entry != NULL;
		    entry = list_next(&thdl->oth_outstanding, entry)) {
			if ((uintptr_t)entry == pkt->otp_reqid)
				break;
		}

		if (entry == NULL) {
			mutex_exit(&thdl->oth_lock);
			freeb(mp);
			return (ENOENT);
		}
		odd = entry->ote_odd;
		mutex_exit(&thdl->oth_lock);
	}

	mp = overlay_m_tx(odd, mp);
	freemsgchain(mp);

	return (0);
}

typedef struct overlay_targ_list_int {
	boolean_t	otli_count;
	uint32_t	otli_cur;
	uint32_t	otli_nents;
	uint32_t	otli_ents[];
} overlay_targ_list_int_t;

static int
overlay_target_list_copyin(const void *ubuf, void **outp, size_t *bsize,
    int flags)
{
	overlay_targ_list_t n;
	overlay_targ_list_int_t *otl;

	if (ddi_copyin(ubuf, &n, sizeof (overlay_targ_list_t),
	    flags & FKIOCTL) != 0)
		return (EFAULT);

	/*
	 */
	if (n.otl_nents >= INT32_MAX / sizeof (uint32_t))
		return (EINVAL);
	*bsize = sizeof (overlay_targ_list_int_t) +
	    sizeof (uint32_t) * n.otl_nents;
	otl = kmem_zalloc(*bsize, KM_SLEEP);
	otl->otli_cur = 0;
	otl->otli_nents = n.otl_nents;
	if (otl->otli_nents != 0) {
		otl->otli_count = B_FALSE;
		if (ddi_copyin((void *)((uintptr_t)ubuf +
		    offsetof(overlay_targ_list_t, otl_ents)),
		    otl->otli_ents, n.otl_nents * sizeof (uint32_t),
		    flags & FKIOCTL) != 0) {
			kmem_free(otl, *bsize);
			return (EFAULT);
		}
	} else {
		otl->otli_count = B_TRUE;
	}

	*outp = otl;
	return (0);
}

static int
overlay_target_ioctl_list_cb(overlay_dev_t *odd, void *arg)
{
	overlay_targ_list_int_t *otl = arg;

	if (otl->otli_cur < otl->otli_nents)
		otl->otli_ents[otl->otli_cur] = odd->odd_linkid;
	otl->otli_cur++;
	return (0);
}

/* ARGSUSED */
static int
overlay_target_ioctl_list(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_iter(overlay_target_ioctl_list_cb, arg);
	return (0);
}

/* ARGSUSED */
static int
overlay_target_list_copyout(void *ubuf, void *buf, size_t bufsize, int flags)
{
	overlay_targ_list_int_t *otl = buf;

	if (ddi_copyout(&otl->otli_cur, ubuf, sizeof (uint32_t),
	    flags & FKIOCTL) != 0)
		return (EFAULT);

	if (otl->otli_count == B_FALSE) {
		if (ddi_copyout(otl->otli_ents,
		    (void *)((uintptr_t)ubuf +
		    offsetof(overlay_targ_list_t, otl_ents)),
		    sizeof (uint32_t) * otl->otli_nents,
		    flags & FKIOCTL) != 0)
			return (EFAULT);
	}
	return (0);
}

/* ARGSUSED */
static int
overlay_target_cache_get(overlay_target_hdl_t *thdl, void *arg)
{
	int ret = 0;
	overlay_dev_t *odd;
	overlay_target_t *ott;
	overlay_targ_cache_t *otc = arg;

	odd = overlay_hold_by_dlid(otc->otc_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	if (!(odd->odd_flags & OVERLAY_F_VARPD)) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENXIO);
	}
	ott = odd->odd_target;
	if (ott->ott_mode != OVERLAY_TARGET_POINT &&
	    ott->ott_mode != OVERLAY_TARGET_DYNAMIC) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENOTSUP);
	}
	mutex_enter(&ott->ott_lock);
	mutex_exit(&odd->odd_lock);

	if (ott->ott_mode == OVERLAY_TARGET_POINT) {
		otc->otc_entry.otce_flags = 0;
		bcopy(&ott->ott_u.ott_point, &otc->otc_entry.otce_dest,
		    sizeof (overlay_target_point_t));
	} else {
		overlay_target_entry_t *ote;
		ote = refhash_lookup(ott->ott_u.ott_dyn.ott_dhash,
		    otc->otc_entry.otce_mac);
		if (ote != NULL) {
			mutex_enter(&ote->ote_lock);
			if ((ote->ote_flags &
			    OVERLAY_ENTRY_F_VALID_MASK) != 0) {
				if (ote->ote_flags & OVERLAY_ENTRY_F_DROP) {
					otc->otc_entry.otce_flags =
					    OVERLAY_TARGET_CACHE_DROP;
				} else {
					otc->otc_entry.otce_flags = 0;
					bcopy(&ote->ote_dest,
					    &otc->otc_entry.otce_dest,
					    sizeof (overlay_target_point_t));
				}
				ret = 0;
			} else {
				ret = ENOENT;
			}
			mutex_exit(&ote->ote_lock);
		} else {
			ret = ENOENT;
		}
	}

	mutex_exit(&ott->ott_lock);
	overlay_hold_rele(odd);

	return (ret);
}

/* ARGSUSED */
static int
overlay_target_cache_set(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_target_t *ott;
	overlay_target_entry_t *ote;
	overlay_targ_cache_t *otc = arg;
	mblk_t *mp = NULL;

	if (otc->otc_entry.otce_flags & ~OVERLAY_TARGET_CACHE_DROP)
		return (EINVAL);

	odd = overlay_hold_by_dlid(otc->otc_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	if (!(odd->odd_flags & OVERLAY_F_VARPD)) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENXIO);
	}
	ott = odd->odd_target;
	if (ott->ott_mode != OVERLAY_TARGET_DYNAMIC) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENOTSUP);
	}
	mutex_enter(&ott->ott_lock);
	mutex_exit(&odd->odd_lock);

	ote = refhash_lookup(ott->ott_u.ott_dyn.ott_dhash,
	    otc->otc_entry.otce_mac);
	if (ote == NULL) {
		ote = kmem_cache_alloc(overlay_entry_cache, KM_SLEEP);
		bcopy(otc->otc_entry.otce_mac, ote->ote_addr, ETHERADDRL);
		ote->ote_chead = ote->ote_ctail = NULL;
		ote->ote_mbsize = 0;
		ote->ote_ott = ott;
		ote->ote_odd = odd;
		mutex_enter(&ote->ote_lock);
		refhash_insert(ott->ott_u.ott_dyn.ott_dhash, ote);
		avl_add(&ott->ott_u.ott_dyn.ott_tree, ote);
	} else {
		mutex_enter(&ote->ote_lock);
	}

	if (otc->otc_entry.otce_flags & OVERLAY_TARGET_CACHE_DROP) {
		ote->ote_flags |= OVERLAY_ENTRY_F_DROP;
	} else {
		ote->ote_flags |= OVERLAY_ENTRY_F_VALID;
		bcopy(&otc->otc_entry.otce_dest, &ote->ote_dest,
		    sizeof (overlay_target_point_t));
		mp = ote->ote_chead;
		ote->ote_chead = NULL;
		ote->ote_ctail = NULL;
		ote->ote_mbsize = 0;
		ote->ote_vtime = gethrtime();
	}

	mutex_exit(&ote->ote_lock);
	mutex_exit(&ott->ott_lock);

	if (mp != NULL) {
		mp = overlay_m_tx(ote->ote_odd, mp);
		freemsgchain(mp);
	}

	overlay_hold_rele(odd);

	return (0);
}

/* ARGSUSED */
static int
overlay_target_cache_remove(overlay_target_hdl_t *thdl, void *arg)
{
	int ret = 0;
	overlay_dev_t *odd;
	overlay_target_t *ott;
	overlay_target_entry_t *ote;
	overlay_targ_cache_t *otc = arg;

	odd = overlay_hold_by_dlid(otc->otc_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	if (!(odd->odd_flags & OVERLAY_F_VARPD)) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENXIO);
	}
	ott = odd->odd_target;
	if (ott->ott_mode != OVERLAY_TARGET_DYNAMIC) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENOTSUP);
	}
	mutex_enter(&ott->ott_lock);
	mutex_exit(&odd->odd_lock);

	ote = refhash_lookup(ott->ott_u.ott_dyn.ott_dhash,
	    otc->otc_entry.otce_mac);
	if (ote != NULL) {
		mutex_enter(&ote->ote_lock);
		ote->ote_flags &= ~OVERLAY_ENTRY_F_VALID_MASK;
		mutex_exit(&ote->ote_lock);
		ret = 0;
	} else {
		ret = ENOENT;
	}

	mutex_exit(&ott->ott_lock);
	overlay_hold_rele(odd);

	return (ret);
}

/* ARGSUSED */
static int
overlay_target_cache_flush(overlay_target_hdl_t *thdl, void *arg)
{
	avl_tree_t *avl;
	overlay_dev_t *odd;
	overlay_target_t *ott;
	overlay_target_entry_t *ote;
	overlay_targ_cache_t *otc = arg;

	odd = overlay_hold_by_dlid(otc->otc_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	if (!(odd->odd_flags & OVERLAY_F_VARPD)) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENXIO);
	}
	ott = odd->odd_target;
	if (ott->ott_mode != OVERLAY_TARGET_DYNAMIC) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENOTSUP);
	}
	mutex_enter(&ott->ott_lock);
	mutex_exit(&odd->odd_lock);
	avl = &ott->ott_u.ott_dyn.ott_tree;

	for (ote = avl_first(avl); ote != NULL; ote = AVL_NEXT(avl, ote)) {
		mutex_enter(&ote->ote_lock);
		ote->ote_flags &= ~OVERLAY_ENTRY_F_VALID_MASK;
		mutex_exit(&ote->ote_lock);
	}
	ote = refhash_lookup(ott->ott_u.ott_dyn.ott_dhash,
	    otc->otc_entry.otce_mac);

	mutex_exit(&ott->ott_lock);
	overlay_hold_rele(odd);

	return (0);
}

static int
overlay_target_cache_iter_copyin(const void *ubuf, void **outp, size_t *bsize,
    int flags)
{
	overlay_targ_cache_iter_t base, *iter;

	if (ddi_copyin(ubuf, &base, sizeof (overlay_targ_cache_iter_t),
	    flags & FKIOCTL) != 0)
		return (EFAULT);

	if (base.otci_count > OVERLAY_TARGET_ITER_MAX)
		return (E2BIG);

	if (base.otci_count == 0)
		return (EINVAL);

	*bsize = sizeof (overlay_targ_cache_iter_t) +
	    base.otci_count * sizeof (overlay_targ_cache_entry_t);
	iter = kmem_alloc(*bsize, KM_SLEEP);
	bcopy(&base, iter, sizeof (overlay_targ_cache_iter_t));
	*outp = iter;

	return (0);
}

typedef struct overlay_targ_cache_marker {
	uint8_t		otcm_mac[ETHERADDRL];
	uint16_t	otcm_done;
} overlay_targ_cache_marker_t;

/* ARGSUSED */
static int
overlay_target_cache_iter(overlay_target_hdl_t *thdl, void *arg)
{
	overlay_dev_t *odd;
	overlay_target_t *ott;
	overlay_target_entry_t lookup, *ent;
	overlay_targ_cache_marker_t *mark;
	avl_index_t where;
	avl_tree_t *avl;
	uint16_t written = 0;

	overlay_targ_cache_iter_t *iter = arg;
	mark = (void *)&iter->otci_marker;

	if (mark->otcm_done != 0) {
		iter->otci_count = 0;
		return (0);
	}

	odd = overlay_hold_by_dlid(iter->otci_linkid);
	if (odd == NULL)
		return (ENOENT);

	mutex_enter(&odd->odd_lock);
	if (!(odd->odd_flags & OVERLAY_F_VARPD)) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENXIO);
	}
	ott = odd->odd_target;
	if (ott->ott_mode != OVERLAY_TARGET_DYNAMIC &&
	    ott->ott_mode != OVERLAY_TARGET_POINT) {
		mutex_exit(&odd->odd_lock);
		overlay_hold_rele(odd);
		return (ENOTSUP);
	}

	/*
	 * Holding this lock across the entire iteration probably isn't very
	 * good. We should perhaps add an r/w lock for the avl tree. But we'll
	 * wait until we now it's necessary before we do more.
	 */
	mutex_enter(&ott->ott_lock);
	mutex_exit(&odd->odd_lock);

	if (ott->ott_mode == OVERLAY_TARGET_POINT) {
		overlay_targ_cache_entry_t *out = &iter->otci_ents[0];
		bzero(out->otce_mac, ETHERADDRL);
		out->otce_flags = 0;
		bcopy(&ott->ott_u.ott_point, &out->otce_dest,
		    sizeof (overlay_target_point_t));
		written++;
		mark->otcm_done = 1;
	}

	avl = &ott->ott_u.ott_dyn.ott_tree;
	bcopy(mark->otcm_mac, lookup.ote_addr, ETHERADDRL);
	ent = avl_find(avl, &lookup, &where);

	/*
	 * NULL ent means that the entry does not exist, so we want to start
	 * with the closest node in the tree. This means that we implicitly rely
	 * on the tree's order and the first node will be the mac 00:00:00:00:00
	 * and the last will be ff:ff:ff:ff:ff:ff.
	 */
	if (ent == NULL) {
		ent = avl_nearest(avl, where, AVL_AFTER);
		if (ent == NULL) {
			mark->otcm_done = 1;
			goto done;
		}
	}

	for (; ent != NULL && written < iter->otci_count;
	    ent = AVL_NEXT(avl, ent)) {
		overlay_targ_cache_entry_t *out = &iter->otci_ents[written];
		mutex_enter(&ent->ote_lock);
		if ((ent->ote_flags & OVERLAY_ENTRY_F_VALID_MASK) == 0) {
			mutex_exit(&ent->ote_lock);
			continue;
		}
		bcopy(ent->ote_addr, out->otce_mac, ETHERADDRL);
		out->otce_flags = 0;
		if (ent->ote_flags & OVERLAY_ENTRY_F_DROP)
			out->otce_flags |= OVERLAY_TARGET_CACHE_DROP;
		if (ent->ote_flags & OVERLAY_ENTRY_F_VALID)
			bcopy(&ent->ote_dest, &out->otce_dest,
			    sizeof (overlay_target_point_t));
		written++;
		mutex_exit(&ent->ote_lock);
	}

	if (ent != NULL) {
		bcopy(ent->ote_addr, mark->otcm_mac, ETHERADDRL);
	} else {
		mark->otcm_done = 1;
	}

done:
	iter->otci_count = written;
	mutex_exit(&ott->ott_lock);
	overlay_hold_rele(odd);

	return (0);
}

/* ARGSUSED */
static int
overlay_target_cache_iter_copyout(void *ubuf, void *buf, size_t bufsize,
    int flags)
{
	size_t outsize;
	const overlay_targ_cache_iter_t *iter = buf;

	outsize = sizeof (overlay_targ_cache_iter_t) +
	    iter->otci_count * sizeof (overlay_targ_cache_entry_t);

	if (ddi_copyout(buf, ubuf, outsize, flags & FKIOCTL) != 0)
		return (EFAULT);

	return (0);
}

static overlay_target_ioctl_t overlay_target_ioctab[] = {
	{ OVERLAY_TARG_INFO, B_TRUE, B_TRUE,
		NULL, overlay_target_info,
		NULL, sizeof (overlay_targ_info_t)	},
	{ OVERLAY_TARG_ASSOCIATE, B_TRUE, B_FALSE,
		NULL, overlay_target_associate,
		NULL, sizeof (overlay_targ_associate_t)	},
	{ OVERLAY_TARG_DISASSOCIATE, B_TRUE, B_FALSE,
		NULL, overlay_target_disassociate,
		NULL, sizeof (overlay_targ_id_t)	},
	{ OVERLAY_TARG_DEGRADE, B_TRUE, B_FALSE,
		NULL, overlay_target_degrade,
		NULL, sizeof (overlay_targ_degrade_t)	},
	{ OVERLAY_TARG_RESTORE, B_TRUE, B_FALSE,
		NULL, overlay_target_restore,
		NULL, sizeof (overlay_targ_id_t)	},
	{ OVERLAY_TARG_LOOKUP, B_FALSE, B_TRUE,
		NULL, overlay_target_lookup_request,
		NULL, sizeof (overlay_targ_lookup_t)	},
	{ OVERLAY_TARG_RESPOND, B_TRUE, B_FALSE,
		NULL, overlay_target_lookup_respond,
		NULL, sizeof (overlay_targ_resp_t)	},
	{ OVERLAY_TARG_DROP, B_TRUE, B_FALSE,
		NULL, overlay_target_lookup_drop,
		NULL, sizeof (overlay_targ_resp_t)	},
	{ OVERLAY_TARG_PKT, B_TRUE, B_TRUE,
		overlay_target_pkt_copyin,
		overlay_target_packet,
		overlay_target_pkt_copyout,
		sizeof (overlay_targ_pkt_t)		},
	{ OVERLAY_TARG_INJECT, B_TRUE, B_FALSE,
		overlay_target_pkt_copyin,
		overlay_target_inject,
		NULL, sizeof (overlay_targ_pkt_t)	},
	{ OVERLAY_TARG_RESEND, B_TRUE, B_FALSE,
		overlay_target_pkt_copyin,
		overlay_target_resend,
		NULL, sizeof (overlay_targ_pkt_t)	},
	{ OVERLAY_TARG_LIST, B_FALSE, B_TRUE,
		overlay_target_list_copyin,
		overlay_target_ioctl_list,
		overlay_target_list_copyout,
		sizeof (overlay_targ_list_t)		},
	{ OVERLAY_TARG_CACHE_GET, B_FALSE, B_TRUE,
		NULL, overlay_target_cache_get,
		NULL, sizeof (overlay_targ_cache_t)	},
	{ OVERLAY_TARG_CACHE_SET, B_TRUE, B_TRUE,
		NULL, overlay_target_cache_set,
		NULL, sizeof (overlay_targ_cache_t)	},
	{ OVERLAY_TARG_CACHE_REMOVE, B_TRUE, B_TRUE,
		NULL, overlay_target_cache_remove,
		NULL, sizeof (overlay_targ_cache_t)	},
	{ OVERLAY_TARG_CACHE_FLUSH, B_TRUE, B_TRUE,
		NULL, overlay_target_cache_flush,
		NULL, sizeof (overlay_targ_cache_t)	},
	{ OVERLAY_TARG_CACHE_ITER, B_FALSE, B_TRUE,
		overlay_target_cache_iter_copyin,
		overlay_target_cache_iter,
		overlay_target_cache_iter_copyout,
		sizeof (overlay_targ_cache_iter_t)		},
	{ 0 }
};

int
overlay_target_open(dev_t *devp, int flags, int otype, cred_t *credp)
{
	minor_t mid;
	overlay_target_hdl_t *thdl;

	if (secpolicy_dl_config(credp) != 0)
		return (EPERM);

	if (getminor(*devp) != 0)
		return (ENXIO);

	if (otype & OTYP_BLK)
		return (EINVAL);

	if (flags & ~(FREAD | FWRITE | FEXCL))
		return (EINVAL);

	if ((flags & FWRITE) &&
	    !(flags & FEXCL))
		return (EINVAL);

	if (!(flags & FREAD) && !(flags & FWRITE))
		return (EINVAL);

	if (crgetzoneid(credp) != GLOBAL_ZONEID)
		return (EPERM);

	mid = id_alloc(overlay_thdl_idspace);
	if (ddi_soft_state_zalloc(overlay_thdl_state, mid) != 0) {
		id_free(overlay_thdl_idspace, mid);
		return (ENXIO);
	}

	thdl = ddi_get_soft_state(overlay_thdl_state, mid);
	VERIFY(thdl != NULL);
	thdl->oth_minor = mid;
	thdl->oth_zoneid = crgetzoneid(credp);
	thdl->oth_oflags = flags;
	mutex_init(&thdl->oth_lock, NULL, MUTEX_DRIVER, NULL);
	list_create(&thdl->oth_outstanding, sizeof (overlay_target_entry_t),
	    offsetof(overlay_target_entry_t, ote_qlink));
	*devp = makedevice(getmajor(*devp), mid);

	mutex_enter(&overlay_target_lock);
	if ((flags & FEXCL) && overlay_target_excl == B_TRUE) {
		mutex_exit(&overlay_target_lock);
		list_destroy(&thdl->oth_outstanding);
		mutex_destroy(&thdl->oth_lock);
		ddi_soft_state_free(overlay_thdl_state, mid);
		id_free(overlay_thdl_idspace, mid);
		return (EEXIST);
	} else if ((flags & FEXCL) != 0) {
		VERIFY(overlay_target_excl == B_FALSE);
		overlay_target_excl = B_TRUE;
	}
	list_insert_tail(&overlay_thdl_list, thdl);
	mutex_exit(&overlay_target_lock);

	return (0);
}

/* ARGSUSED */
int
overlay_target_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp,
    int *rvalp)
{
	overlay_target_ioctl_t *ioc;
	overlay_target_hdl_t *thdl;

	if (secpolicy_dl_config(credp) != 0)
		return (EPERM);

	if ((thdl = ddi_get_soft_state(overlay_thdl_state,
	    getminor(dev))) == NULL)
		return (ENXIO);

	for (ioc = &overlay_target_ioctab[0]; ioc->oti_cmd != 0; ioc++) {
		int ret;
		caddr_t buf;
		size_t bufsize;

		if (ioc->oti_cmd != cmd)
			continue;

		if (ioc->oti_write == B_TRUE && !(mode & FWRITE))
			return (EBADF);

		if (ioc->oti_copyin == NULL) {
			bufsize = ioc->oti_size;
			buf = kmem_alloc(bufsize, KM_SLEEP);
			if (ddi_copyin((void *)(uintptr_t)arg, buf, bufsize,
			    mode & FKIOCTL) != 0) {
				kmem_free(buf, bufsize);
				return (EFAULT);
			}
		} else {
			if ((ret = ioc->oti_copyin((void *)(uintptr_t)arg,
			    (void **)&buf, &bufsize, mode)) != 0)
				return (ret);
		}

		ret = ioc->oti_func(thdl, buf);
		if (ret == 0 && ioc->oti_size != 0 &&
		    ioc->oti_ncopyout == B_TRUE) {
			if (ioc->oti_copyout == NULL) {
				if (ddi_copyout(buf, (void *)(uintptr_t)arg,
				    bufsize, mode & FKIOCTL) != 0)
					ret = EFAULT;
			} else {
				ret = ioc->oti_copyout((void *)(uintptr_t)arg,
				    buf, bufsize, mode);
			}
		}

		kmem_free(buf, bufsize);
		return (ret);
	}

	return (ENOTTY);
}

/* ARGSUSED */
int
overlay_target_close(dev_t dev, int flags, int otype, cred_t *credp)
{
	overlay_target_hdl_t *thdl;
	overlay_target_entry_t *entry;
	minor_t mid = getminor(dev);

	if ((thdl = ddi_get_soft_state(overlay_thdl_state, mid)) == NULL)
		return (ENXIO);

	mutex_enter(&overlay_target_lock);
	list_remove(&overlay_thdl_list, thdl);
	mutex_enter(&thdl->oth_lock);
	while ((entry = list_remove_head(&thdl->oth_outstanding)) != NULL)
		list_insert_tail(&overlay_target_list, entry);
	cv_signal(&overlay_target_condvar);
	mutex_exit(&thdl->oth_lock);
	if ((thdl->oth_oflags & FEXCL) != 0) {
		VERIFY(overlay_target_excl == B_TRUE);
		overlay_target_excl = B_FALSE;
	}
	mutex_exit(&overlay_target_lock);

	list_destroy(&thdl->oth_outstanding);
	mutex_destroy(&thdl->oth_lock);
	mid = thdl->oth_minor;
	ddi_soft_state_free(overlay_thdl_state, mid);
	id_free(overlay_thdl_idspace, mid);

	return (0);
}
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2018 Joyent, Inc.
 * Copyright 2022 MNX Cloud, Inc.
 */

/*
 * VXLAN encapsulation module
 *
 *
 * The VXLAN header looks as follows in network byte order:
 *
 * |0        3| 4 |5                     31|
 * +----------+---+------------------------+
 * | Reserved | I | Reserved               |
 * +---------------------------------------+
 * | Virtual Network ID         | Reserved |
 * +----------------------------+----------+
 * |0                         23|24      31|
 *
 * All reserved values must be 0. The I bit must be 1. We call the top
 * word the VXLAN magic field for the time being. The second word is
 * definitely not the most friendly way to operate. Specifically, the ID
 * is a 24-bit big endian value, but we have to make sure not to use the
 * reserved byte.
 *
 * For us, VXLAN encapsulation is a fairly straightforward implementation. It
 * only has two properties, a listen_ip and a listen_port. These determine on
 * what address we should be listening on. While we do not have a default
 * address to listen upon, we do have a default port, which is the IANA assigned
 * port for VXLAN -- 4789.
 */

#include <sys/overlay_plugin.h>
#include <sys/modctl.h>
#include <sys/errno.h>
#include <sys/byteorder.h>
#include <sys/vxlan.h>
#include <inet/ip.h>
#include <netinet/in.h>
#include <sys/strsun.h>
#include <netinet/udp.h>

static const char *vxlan_ident = "vxlan";
static uint16_t vxlan_defport = IPPORT_VXLAN;

/*
 * Should we enable UDP source port hashing for fanout.
 */
boolean_t vxlan_fanout = B_TRUE;

/*
 * This represents the size in bytes that we want to allocate when allocating a
 * vxlan header block. This is intended such that lower levels can try and use
 * the message block that we allocate for the IP and UPD header. The hope is
 * that even if this is tunneled, that this is enough space.
 *
 * The vxlan_noalloc_min value represents the minimum amount of space we need to
 * consider not allocating a message block and just passing it down the stack in
 * this form. This number assumes that we have a VLAN tag, so 18 byte Ethernet
 * header, 20 byte IP header, 8 byte UDP header, and 8 byte VXLAN header.
 */
uint_t vxlan_alloc_size = 128;
uint_t vxlan_noalloc_min = 54;

static const char *vxlan_props[] = {
	"vxlan/listen_ip",
	"vxlan/listen_port",
	NULL
};

typedef struct vxlan {
	kmutex_t vxl_lock;
	overlay_handle_t vxl_oh;
	uint16_t vxl_lport;
	boolean_t vxl_hladdr;
	struct in6_addr vxl_laddr;
} vxlan_t;

static int
vxlan_o_init(overlay_handle_t oh, void **outp)
{
	vxlan_t *vxl;

	vxl = kmem_alloc(sizeof (vxlan_t), KM_SLEEP);
	*outp = vxl;
	mutex_init(&vxl->vxl_lock, NULL, MUTEX_DRIVER, NULL);
	vxl->vxl_oh = oh;
	vxl->vxl_lport = vxlan_defport;
	vxl->vxl_hladdr = B_FALSE;

	return (0);
}

static void
vxlan_o_fini(void *arg)
{
	vxlan_t *vxl = arg;

	mutex_destroy(&vxl->vxl_lock);
	kmem_free(arg, sizeof (vxlan_t));
}

static int
vxlan_o_socket(void *arg, int *dp, int *fp, int *pp, struct sockaddr *addr,
    socklen_t *slenp)
{
	vxlan_t *vxl = arg;
	struct sockaddr_in6 *in;

	in = (struct sockaddr_in6 *)addr;
	*dp = AF_INET6;
	*fp = SOCK_DGRAM;
	*pp = 0;
	bzero(in, sizeof (struct sockaddr_in6));
	in->sin6_family = AF_INET6;

	/*
	 * We should consider a more expressive private errno set that
	 * provider's can use.
	 */
	mutex_enter(&vxl->vxl_lock);
	if (vxl->vxl_hladdr == B_FALSE) {
		mutex_exit(&vxl->vxl_lock);
		return (EINVAL);
	}
	in->sin6_port = htons(vxl->vxl_lport);
	in->sin6_addr = vxl->vxl_laddr;
	mutex_exit(&vxl->vxl_lock);
	*slenp = sizeof (struct sockaddr_in6);

	return (0);
}

static int
vxlan_o_sockopt(ksocket_t ksock)
{
	int val, err;
	if (vxlan_fanout == B_FALSE)
		return (0);

	val = UDP_HASH_VXLAN;
	err = ksocket_setsockopt(ksock, IPPROTO_UDP, UDP_SRCPORT_HASH, &val,
	    sizeof (val), kcred);
	return (err);
}

/* ARGSUSED */
static int
vxlan_o_encap(void *arg, mblk_t *mp, ovep_encap_info_t *einfop,
    mblk_t **outp)
{
	mblk_t *ob;
	vxlan_hdr_t *vxh;

	ASSERT(einfop->ovdi_id < (1 << 24));

	if (DB_REF(mp) != 1 || mp->b_rptr - vxlan_noalloc_min < DB_BASE(mp)) {
		/*
		 * This allocation could get hot. We may want to have a good
		 * way to cache and handle this allocation the same way that IP
		 * does with keeping around a message block per entry, or
		 * basically treating this as an immutable message block in the
		 * system. Basically freemsg() will be a nop, but we'll do the
		 * right thing with respect to the rest of the chain.
		 */
		ob = allocb(vxlan_alloc_size, 0);
		if (ob == NULL)
			return (ENOMEM);

		ob->b_wptr = DB_LIM(ob);
		ob->b_rptr = ob->b_wptr;
		ob->b_cont = mp;
	} else {
		ob = mp;
	}
	ob->b_rptr -= VXLAN_HDR_LEN;

	vxh = (vxlan_hdr_t *)ob->b_rptr;
	vxh->vxlan_flags = ntohl(VXLAN_F_VDI);
	vxh->vxlan_id = htonl((uint32_t)einfop->ovdi_id << VXLAN_ID_SHIFT);
	*outp = ob;

	return (0);
}

/* ARGSUSED */
static int
vxlan_o_decap(void *arg, mblk_t *mp, ovep_encap_info_t *dinfop)
{
	vxlan_hdr_t *vxh;

	if (MBLKL(mp) < sizeof (vxlan_hdr_t))
		return (EINVAL);
	vxh = (vxlan_hdr_t *)mp->b_rptr;
	if ((ntohl(vxh->vxlan_flags) & VXLAN_F_VDI) == 0)
		return (EINVAL);

	dinfop->ovdi_id = ntohl(vxh->vxlan_id) >> VXLAN_ID_SHIFT;
	dinfop->ovdi_hdr_size = VXLAN_HDR_LEN;

	return (0);
}

static int
vxlan_o_getprop(void *arg, const char *pr_name, void *buf, uint32_t *bufsize)
{
	vxlan_t *vxl = arg;

	/* vxlan/listen_ip */
	if (strcmp(pr_name, vxlan_props[0]) == 0) {
		if (*bufsize < sizeof (struct in6_addr))
			return (EOVERFLOW);

		mutex_enter(&vxl->vxl_lock);
		if (vxl->vxl_hladdr == B_FALSE) {
			*bufsize = 0;
		} else {
			bcopy(&vxl->vxl_laddr, buf, sizeof (struct in6_addr));
			*bufsize = sizeof (struct in6_addr);
		}
		mutex_exit(&vxl->vxl_lock);
		return (0);
	}

	/* vxlan/listen_port */
	if (strcmp(pr_name, vxlan_props[1]) == 0) {
		uint64_t val;
		if (*bufsize < sizeof (uint64_t))
			return (EOVERFLOW);

		mutex_enter(&vxl->vxl_lock);
		val = vxl->vxl_lport;
		bcopy(&val, buf, sizeof (uint64_t));
		*bufsize = sizeof (uint64_t);
		mutex_exit(&vxl->vxl_lock);
		return (0);
	}

	return (EINVAL);
}

static int
vxlan_o_setprop(void *arg, const char *pr_name, const void *buf,
    uint32_t bufsize)
{
	vxlan_t *vxl = arg;

	/* vxlan/listen_ip */
	if (strcmp(pr_name, vxlan_props[0]) == 0) {
		const struct in6_addr *ipv6 = buf;
		if (bufsize != sizeof (struct in6_addr))
			return (EINVAL);

		if (IN6_IS_ADDR_V4COMPAT(ipv6))
			return (EINVAL);

		if (IN6_IS_ADDR_MULTICAST(ipv6))
			return (EINVAL);

		if (IN6_IS_ADDR_6TO4(ipv6))
			return (EINVAL);

		if (IN6_IS_ADDR_V4MAPPED(ipv6)) {
			ipaddr_t v4;
			IN6_V4MAPPED_TO_IPADDR(ipv6, v4);
			if (IN_MULTICAST(ntohl(v4)))
				return (EINVAL);
		}

		mutex_enter(&vxl->vxl_lock);
		vxl->vxl_hladdr = B_TRUE;
		bcopy(ipv6, &vxl->vxl_laddr, sizeof (struct in6_addr));
		mutex_exit(&vxl->vxl_lock);

		return (0);
	}

	/* vxlan/listen_port */
	if (strcmp(pr_name, vxlan_props[1]) == 0) {
		const uint64_t *valp = buf;
		if (bufsize != 8)
			return (EINVAL);

		if (*valp == 0 || *valp > UINT16_MAX)
			return (EINVAL);

		mutex_enter(&vxl->vxl_lock);
		vxl->vxl_lport = *valp;
		mutex_exit(&vxl->vxl_lock);
		return (0);
	}
	return (EINVAL);
}

static int
vxlan_o_propinfo(const char *pr_name, overlay_prop_handle_t phdl)
{
	/* vxlan/listen_ip */
	if (strcmp(pr_name, vxlan_props[0]) == 0) {
		overlay_prop_set_name(phdl, vxlan_props[0]);
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_RRW);
		overlay_prop_set_type(phdl, OVERLAY_PROP_T_IP);
		overlay_prop_set_nodefault(phdl);
		return (0);
	}

	if (strcmp(pr_name, vxlan_props[1]) == 0) {
		overlay_prop_set_name(phdl, vxlan_props[1]);
		overlay_prop_set_prot(phdl, OVERLAY_PROP_PERM_RRW);
		overlay_prop_set_type(phdl, OVERLAY_PROP_T_UINT);
		(void) overlay_prop_set_default(phdl, &vxlan_defport,
		    sizeof (vxlan_defport));
		overlay_prop_set_range_uint32(phdl, 1, UINT16_MAX);
		return (0);
	}

	return (EINVAL);
}

static struct overlay_plugin_ops vxlan_o_ops = {
	0,
	vxlan_o_init,
	vxlan_o_fini,
	vxlan_o_encap,
	vxlan_o_decap,
	vxlan_o_socket,
	vxlan_o_sockopt,
	vxlan_o_getprop,
	vxlan_o_setprop,
	vxlan_o_propinfo
};

static struct modlmisc vxlan_modlmisc = {
	&mod_miscops,
	"VXLAN encap plugin"
};

static struct modlinkage vxlan_modlinkage = {
	MODREV_1,
	&vxlan_modlmisc
};

int
_init(void)
{
	int err;
	overlay_plugin_register_t *ovrp;

	ovrp = overlay_plugin_alloc(OVEP_VERSION);
	if (ovrp == NULL)
		return (ENOTSUP);
	ovrp->ovep_name = vxlan_ident;
	ovrp->ovep_ops = &vxlan_o_ops;
	ovrp->ovep_id_size = VXLAN_ID_LEN;
	ovrp->ovep_flags = OVEP_F_VLAN_TAG;
	ovrp->ovep_dest = OVERLAY_PLUGIN_D_IP | OVERLAY_PLUGIN_D_PORT;
	ovrp->ovep_props = vxlan_props;

	if ((err = overlay_plugin_register(ovrp)) == 0) {
		if ((err = mod_install(&vxlan_modlinkage)) != 0) {
			(void) overlay_plugin_unregister(vxlan_ident);
		}
	}

	overlay_plugin_free(ovrp);
	return (err);
}

int
_info(struct modinfo *modinfop)
{
	return (mod_info(&vxlan_modlinkage, modinfop));
}

int
_fini(void)
{
	int err;

	if ((err = overlay_plugin_unregister(vxlan_ident)) != 0)
		return (err);

	return (mod_remove(&vxlan_modlinkage));
}