/* * VMware vSockets Driver * * Copyright (C) 2007-2013 VMware, Inc. All rights reserved. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation version 2 and no later version. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ /* Implementation notes: * * - There are two kinds of sockets: those created by user action (such as * calling socket(2)) and those created by incoming connection request packets. * * - There are two "global" tables, one for bound sockets (sockets that have * specified an address that they are responsible for) and one for connected * sockets (sockets that have established a connection with another socket). * These tables are "global" in that all sockets on the system are placed * within them. - Note, though, that the bound table contains an extra entry * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in * that list. The bound table is used solely for lookup of sockets when packets * are received and that's not necessary for SOCK_DGRAM sockets since we create * a datagram handle for each and need not perform a lookup. Keeping SOCK_DGRAM * sockets out of the bound hash buckets will reduce the chance of collisions * when looking for SOCK_STREAM sockets and prevents us from having to check the * socket type in the hash table lookups. * * - Sockets created by user action will either be "client" sockets that * initiate a connection or "server" sockets that listen for connections; we do * not support simultaneous connects (two "client" sockets connecting). * * - "Server" sockets are referred to as listener sockets throughout this * implementation because they are in the SS_LISTEN state. When a connection * request is received (the second kind of socket mentioned above), we create a * new socket and refer to it as a pending socket. These pending sockets are * placed on the pending connection list of the listener socket. When future * packets are received for the address the listener socket is bound to, we * check if the source of the packet is from one that has an existing pending * connection. If it does, we process the packet for the pending socket. When * that socket reaches the connected state, it is removed from the listener * socket's pending list and enqueued in the listener socket's accept queue. * Callers of accept(2) will accept connected sockets from the listener socket's * accept queue. If the socket cannot be accepted for some reason then it is * marked rejected. Once the connection is accepted, it is owned by the user * process and the responsibility for cleanup falls with that user process. * * - It is possible that these pending sockets will never reach the connected * state; in fact, we may never receive another packet after the connection * request. Because of this, we must schedule a cleanup function to run in the * future, after some amount of time passes where a connection should have been * established. This function ensures that the socket is off all lists so it * cannot be retrieved, then drops all references to the socket so it is cleaned * up (sock_put() -> sk_free() -> our sk_destruct implementation). Note this * function will also cleanup rejected sockets, those that reach the connected * state but leave it before they have been accepted. * * - Sockets created by user action will be cleaned up when the user process * calls close(2), causing our release implementation to be called. Our release * implementation will perform some cleanup then drop the last reference so our * sk_destruct implementation is invoked. Our sk_destruct implementation will * perform additional cleanup that's common for both types of sockets. * * - A socket's reference count is what ensures that the structure won't be * freed. Each entry in a list (such as the "global" bound and connected tables * and the listener socket's pending list and connected queue) ensures a * reference. When we defer work until process context and pass a socket as our * argument, we must ensure the reference count is increased to ensure the * socket isn't freed before the function is run; the deferred function will * then drop the reference. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "af_vsock.h" static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr); static void vsock_sk_destruct(struct sock *sk); static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); /* Protocol family. */ static struct proto vsock_proto = { .name = "AF_VSOCK", .owner = THIS_MODULE, .obj_size = sizeof(struct vsock_sock), }; /* The default peer timeout indicates how long we will wait for a peer response * to a control message. */ #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ) #define SS_LISTEN 255 static const struct vsock_transport *transport; static DEFINE_MUTEX(vsock_register_mutex); /**** EXPORTS ****/ /* Get the ID of the local context. This is transport dependent. */ int vm_sockets_get_local_cid(void) { return transport->get_local_cid(); } EXPORT_SYMBOL_GPL(vm_sockets_get_local_cid); /**** UTILS ****/ /* Each bound VSocket is stored in the bind hash table and each connected * VSocket is stored in the connected hash table. * * Unbound sockets are all put on the same list attached to the end of the hash * table (vsock_unbound_sockets). Bound sockets are added to the hash table in * the bucket that their local address hashes to (vsock_bound_sockets(addr) * represents the list that addr hashes to). * * Specifically, we initialize the vsock_bind_table array to a size of * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets. The hash function * mods with VSOCK_HASH_SIZE - 1 to ensure this. */ #define VSOCK_HASH_SIZE 251 #define MAX_PORT_RETRIES 24 #define VSOCK_HASH(addr) ((addr)->svm_port % (VSOCK_HASH_SIZE - 1)) #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)]) #define vsock_unbound_sockets (&vsock_bind_table[VSOCK_HASH_SIZE]) /* XXX This can probably be implemented in a better way. */ #define VSOCK_CONN_HASH(src, dst) \ (((src)->svm_cid ^ (dst)->svm_port) % (VSOCK_HASH_SIZE - 1)) #define vsock_connected_sockets(src, dst) \ (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)]) #define vsock_connected_sockets_vsk(vsk) \ vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr) static struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1]; static struct list_head vsock_connected_table[VSOCK_HASH_SIZE]; static DEFINE_SPINLOCK(vsock_table_lock); static void vsock_init_tables(void) { int i; for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++) INIT_LIST_HEAD(&vsock_bind_table[i]); for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) INIT_LIST_HEAD(&vsock_connected_table[i]); } static void __vsock_insert_bound(struct list_head *list, struct vsock_sock *vsk) { sock_hold(&vsk->sk); list_add(&vsk->bound_table, list); } static void __vsock_insert_connected(struct list_head *list, struct vsock_sock *vsk) { sock_hold(&vsk->sk); list_add(&vsk->connected_table, list); } static void __vsock_remove_bound(struct vsock_sock *vsk) { list_del_init(&vsk->bound_table); sock_put(&vsk->sk); } static void __vsock_remove_connected(struct vsock_sock *vsk) { list_del_init(&vsk->connected_table); sock_put(&vsk->sk); } static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr) { struct vsock_sock *vsk; list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) if (addr->svm_port == vsk->local_addr.svm_port) return sk_vsock(vsk); return NULL; } static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src, struct sockaddr_vm *dst) { struct vsock_sock *vsk; list_for_each_entry(vsk, vsock_connected_sockets(src, dst), connected_table) { if (vsock_addr_equals_addr(src, &vsk->remote_addr) && dst->svm_port == vsk->local_addr.svm_port) { return sk_vsock(vsk); } } return NULL; } static bool __vsock_in_bound_table(struct vsock_sock *vsk) { return !list_empty(&vsk->bound_table); } static bool __vsock_in_connected_table(struct vsock_sock *vsk) { return !list_empty(&vsk->connected_table); } static void vsock_insert_unbound(struct vsock_sock *vsk) { spin_lock_bh(&vsock_table_lock); __vsock_insert_bound(vsock_unbound_sockets, vsk); spin_unlock_bh(&vsock_table_lock); } void vsock_insert_connected(struct vsock_sock *vsk) { struct list_head *list = vsock_connected_sockets( &vsk->remote_addr, &vsk->local_addr); spin_lock_bh(&vsock_table_lock); __vsock_insert_connected(list, vsk); spin_unlock_bh(&vsock_table_lock); } EXPORT_SYMBOL_GPL(vsock_insert_connected); void vsock_remove_bound(struct vsock_sock *vsk) { spin_lock_bh(&vsock_table_lock); __vsock_remove_bound(vsk); spin_unlock_bh(&vsock_table_lock); } EXPORT_SYMBOL_GPL(vsock_remove_bound); void vsock_remove_connected(struct vsock_sock *vsk) { spin_lock_bh(&vsock_table_lock); __vsock_remove_connected(vsk); spin_unlock_bh(&vsock_table_lock); } EXPORT_SYMBOL_GPL(vsock_remove_connected); struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr) { struct sock *sk; spin_lock_bh(&vsock_table_lock); sk = __vsock_find_bound_socket(addr); if (sk) sock_hold(sk); spin_unlock_bh(&vsock_table_lock); return sk; } EXPORT_SYMBOL_GPL(vsock_find_bound_socket); struct sock *vsock_find_connected_socket(struct sockaddr_vm *src, struct sockaddr_vm *dst) { struct sock *sk; spin_lock_bh(&vsock_table_lock); sk = __vsock_find_connected_socket(src, dst); if (sk) sock_hold(sk); spin_unlock_bh(&vsock_table_lock); return sk; } EXPORT_SYMBOL_GPL(vsock_find_connected_socket); static bool vsock_in_bound_table(struct vsock_sock *vsk) { bool ret; spin_lock_bh(&vsock_table_lock); ret = __vsock_in_bound_table(vsk); spin_unlock_bh(&vsock_table_lock); return ret; } static bool vsock_in_connected_table(struct vsock_sock *vsk) { bool ret; spin_lock_bh(&vsock_table_lock); ret = __vsock_in_connected_table(vsk); spin_unlock_bh(&vsock_table_lock); return ret; } void vsock_for_each_connected_socket(void (*fn)(struct sock *sk)) { int i; spin_lock_bh(&vsock_table_lock); for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) { struct vsock_sock *vsk; list_for_each_entry(vsk, &vsock_connected_table[i], connected_table); fn(sk_vsock(vsk)); } spin_unlock_bh(&vsock_table_lock); } EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket); void vsock_add_pending(struct sock *listener, struct sock *pending) { struct vsock_sock *vlistener; struct vsock_sock *vpending; vlistener = vsock_sk(listener); vpending = vsock_sk(pending); sock_hold(pending); sock_hold(listener); list_add_tail(&vpending->pending_links, &vlistener->pending_links); } EXPORT_SYMBOL_GPL(vsock_add_pending); void vsock_remove_pending(struct sock *listener, struct sock *pending) { struct vsock_sock *vpending = vsock_sk(pending); list_del_init(&vpending->pending_links); sock_put(listener); sock_put(pending); } EXPORT_SYMBOL_GPL(vsock_remove_pending); void vsock_enqueue_accept(struct sock *listener, struct sock *connected) { struct vsock_sock *vlistener; struct vsock_sock *vconnected; vlistener = vsock_sk(listener); vconnected = vsock_sk(connected); sock_hold(connected); sock_hold(listener); list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue); } EXPORT_SYMBOL_GPL(vsock_enqueue_accept); static struct sock *vsock_dequeue_accept(struct sock *listener) { struct vsock_sock *vlistener; struct vsock_sock *vconnected; vlistener = vsock_sk(listener); if (list_empty(&vlistener->accept_queue)) return NULL; vconnected = list_entry(vlistener->accept_queue.next, struct vsock_sock, accept_queue); list_del_init(&vconnected->accept_queue); sock_put(listener); /* The caller will need a reference on the connected socket so we let * it call sock_put(). */ return sk_vsock(vconnected); } static bool vsock_is_accept_queue_empty(struct sock *sk) { struct vsock_sock *vsk = vsock_sk(sk); return list_empty(&vsk->accept_queue); } static bool vsock_is_pending(struct sock *sk) { struct vsock_sock *vsk = vsock_sk(sk); return !list_empty(&vsk->pending_links); } static int vsock_send_shutdown(struct sock *sk, int mode) { return transport->shutdown(vsock_sk(sk), mode); } void vsock_pending_work(struct work_struct *work) { struct sock *sk; struct sock *listener; struct vsock_sock *vsk; bool cleanup; vsk = container_of(work, struct vsock_sock, dwork.work); sk = sk_vsock(vsk); listener = vsk->listener; cleanup = true; lock_sock(listener); lock_sock(sk); if (vsock_is_pending(sk)) { vsock_remove_pending(listener, sk); } else if (!vsk->rejected) { /* We are not on the pending list and accept() did not reject * us, so we must have been accepted by our user process. We * just need to drop our references to the sockets and be on * our way. */ cleanup = false; goto out; } listener->sk_ack_backlog--; /* We need to remove ourself from the global connected sockets list so * incoming packets can't find this socket, and to reduce the reference * count. */ if (vsock_in_connected_table(vsk)) vsock_remove_connected(vsk); sk->sk_state = SS_FREE; out: release_sock(sk); release_sock(listener); if (cleanup) sock_put(sk); sock_put(sk); sock_put(listener); } EXPORT_SYMBOL_GPL(vsock_pending_work); /**** SOCKET OPERATIONS ****/ static int __vsock_bind_stream(struct vsock_sock *vsk, struct sockaddr_vm *addr) { static u32 port = LAST_RESERVED_PORT + 1; struct sockaddr_vm new_addr; vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port); if (addr->svm_port == VMADDR_PORT_ANY) { bool found = false; unsigned int i; for (i = 0; i < MAX_PORT_RETRIES; i++) { if (port <= LAST_RESERVED_PORT) port = LAST_RESERVED_PORT + 1; new_addr.svm_port = port++; if (!__vsock_find_bound_socket(&new_addr)) { found = true; break; } } if (!found) return -EADDRNOTAVAIL; } else { /* If port is in reserved range, ensure caller * has necessary privileges. */ if (addr->svm_port <= LAST_RESERVED_PORT && !capable(CAP_NET_BIND_SERVICE)) { return -EACCES; } if (__vsock_find_bound_socket(&new_addr)) return -EADDRINUSE; } vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port); /* Remove stream sockets from the unbound list and add them to the hash * table for easy lookup by its address. The unbound list is simply an * extra entry at the end of the hash table, a trick used by AF_UNIX. */ __vsock_remove_bound(vsk); __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk); return 0; } static int __vsock_bind_dgram(struct vsock_sock *vsk, struct sockaddr_vm *addr) { return transport->dgram_bind(vsk, addr); } static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr) { struct vsock_sock *vsk = vsock_sk(sk); u32 cid; int retval; /* First ensure this socket isn't already bound. */ if (vsock_addr_bound(&vsk->local_addr)) return -EINVAL; /* Now bind to the provided address or select appropriate values if * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY). Note that * like AF_INET prevents binding to a non-local IP address (in most * cases), we only allow binding to the local CID. */ cid = transport->get_local_cid(); if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY) return -EADDRNOTAVAIL; switch (sk->sk_socket->type) { case SOCK_STREAM: spin_lock_bh(&vsock_table_lock); retval = __vsock_bind_stream(vsk, addr); spin_unlock_bh(&vsock_table_lock); break; case SOCK_DGRAM: retval = __vsock_bind_dgram(vsk, addr); break; default: retval = -EINVAL; break; } return retval; } struct sock *__vsock_create(struct net *net, struct socket *sock, struct sock *parent, gfp_t priority, unsigned short type) { struct sock *sk; struct vsock_sock *psk; struct vsock_sock *vsk; sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto); if (!sk) return NULL; sock_init_data(sock, sk); /* sk->sk_type is normally set in sock_init_data, but only if sock is * non-NULL. We make sure that our sockets always have a type by * setting it here if needed. */ if (!sock) sk->sk_type = type; vsk = vsock_sk(sk); vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); sk->sk_destruct = vsock_sk_destruct; sk->sk_backlog_rcv = vsock_queue_rcv_skb; sk->sk_state = 0; sock_reset_flag(sk, SOCK_DONE); INIT_LIST_HEAD(&vsk->bound_table); INIT_LIST_HEAD(&vsk->connected_table); vsk->listener = NULL; INIT_LIST_HEAD(&vsk->pending_links); INIT_LIST_HEAD(&vsk->accept_queue); vsk->rejected = false; vsk->sent_request = false; vsk->ignore_connecting_rst = false; vsk->peer_shutdown = 0; psk = parent ? vsock_sk(parent) : NULL; if (parent) { vsk->trusted = psk->trusted; vsk->owner = get_cred(psk->owner); vsk->connect_timeout = psk->connect_timeout; } else { vsk->trusted = capable(CAP_NET_ADMIN); vsk->owner = get_current_cred(); vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT; } if (transport->init(vsk, psk) < 0) { sk_free(sk); return NULL; } if (sock) vsock_insert_unbound(vsk); return sk; } EXPORT_SYMBOL_GPL(__vsock_create); static void __vsock_release(struct sock *sk) { if (sk) { struct sk_buff *skb; struct sock *pending; struct vsock_sock *vsk; vsk = vsock_sk(sk); pending = NULL; /* Compiler warning. */ if (vsock_in_bound_table(vsk)) vsock_remove_bound(vsk); if (vsock_in_connected_table(vsk)) vsock_remove_connected(vsk); transport->release(vsk); lock_sock(sk); sock_orphan(sk); sk->sk_shutdown = SHUTDOWN_MASK; while ((skb = skb_dequeue(&sk->sk_receive_queue))) kfree_skb(skb); /* Clean up any sockets that never were accepted. */ while ((pending = vsock_dequeue_accept(sk)) != NULL) { __vsock_release(pending); sock_put(pending); } release_sock(sk); sock_put(sk); } } static void vsock_sk_destruct(struct sock *sk) { struct vsock_sock *vsk = vsock_sk(sk); transport->destruct(vsk); /* When clearing these addresses, there's no need to set the family and * possibly register the address family with the kernel. */ vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); put_cred(vsk->owner); } static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { int err; err = sock_queue_rcv_skb(sk, skb); if (err) kfree_skb(skb); return err; } s64 vsock_stream_has_data(struct vsock_sock *vsk) { return transport->stream_has_data(vsk); } EXPORT_SYMBOL_GPL(vsock_stream_has_data); s64 vsock_stream_has_space(struct vsock_sock *vsk) { return transport->stream_has_space(vsk); } EXPORT_SYMBOL_GPL(vsock_stream_has_space); static int vsock_release(struct socket *sock) { __vsock_release(sock->sk); sock->sk = NULL; sock->state = SS_FREE; return 0; } static int vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len) { int err; struct sock *sk; struct sockaddr_vm *vm_addr; sk = sock->sk; if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0) return -EINVAL; lock_sock(sk); err = __vsock_bind(sk, vm_addr); release_sock(sk); return err; } static int vsock_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) { int err; struct sock *sk; struct vsock_sock *vsk; struct sockaddr_vm *vm_addr; sk = sock->sk; vsk = vsock_sk(sk); err = 0; lock_sock(sk); if (peer) { if (sock->state != SS_CONNECTED) { err = -ENOTCONN; goto out; } vm_addr = &vsk->remote_addr; } else { vm_addr = &vsk->local_addr; } if (!vm_addr) { err = -EINVAL; goto out; } /* sys_getsockname() and sys_getpeername() pass us a * MAX_SOCK_ADDR-sized buffer and don't set addr_len. Unfortunately * that macro is defined in socket.c instead of .h, so we hardcode its * value here. */ BUILD_BUG_ON(sizeof(*vm_addr) > 128); memcpy(addr, vm_addr, sizeof(*vm_addr)); *addr_len = sizeof(*vm_addr); out: release_sock(sk); return err; } static int vsock_shutdown(struct socket *sock, int mode) { int err; struct sock *sk; /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode * here like the other address families do. Note also that the * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3), * which is what we want. */ mode++; if ((mode & ~SHUTDOWN_MASK) || !mode) return -EINVAL; /* If this is a STREAM socket and it is not connected then bail out * immediately. If it is a DGRAM socket then we must first kick the * socket so that it wakes up from any sleeping calls, for example * recv(), and then afterwards return the error. */ sk = sock->sk; if (sock->state == SS_UNCONNECTED) { err = -ENOTCONN; if (sk->sk_type == SOCK_STREAM) return err; } else { sock->state = SS_DISCONNECTING; err = 0; } /* Receive and send shutdowns are treated alike. */ mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN); if (mode) { lock_sock(sk); sk->sk_shutdown |= mode; sk->sk_state_change(sk); release_sock(sk); if (sk->sk_type == SOCK_STREAM) { sock_reset_flag(sk, SOCK_DONE); vsock_send_shutdown(sk, mode); } } return err; } static unsigned int vsock_poll(struct file *file, struct socket *sock, poll_table *wait) { struct sock *sk; unsigned int mask; struct vsock_sock *vsk; sk = sock->sk; vsk = vsock_sk(sk); poll_wait(file, sk_sleep(sk), wait); mask = 0; if (sk->sk_err) /* Signify that there has been an error on this socket. */ mask |= POLLERR; /* INET sockets treat local write shutdown and peer write shutdown as a * case of POLLHUP set. */ if ((sk->sk_shutdown == SHUTDOWN_MASK) || ((sk->sk_shutdown & SEND_SHUTDOWN) && (vsk->peer_shutdown & SEND_SHUTDOWN))) { mask |= POLLHUP; } if (sk->sk_shutdown & RCV_SHUTDOWN || vsk->peer_shutdown & SEND_SHUTDOWN) { mask |= POLLRDHUP; } if (sock->type == SOCK_DGRAM) { /* For datagram sockets we can read if there is something in * the queue and write as long as the socket isn't shutdown for * sending. */ if (!skb_queue_empty(&sk->sk_receive_queue) || (sk->sk_shutdown & RCV_SHUTDOWN)) { mask |= POLLIN | POLLRDNORM; } if (!(sk->sk_shutdown & SEND_SHUTDOWN)) mask |= POLLOUT | POLLWRNORM | POLLWRBAND; } else if (sock->type == SOCK_STREAM) { lock_sock(sk); /* Listening sockets that have connections in their accept * queue can be read. */ if (sk->sk_state == SS_LISTEN && !vsock_is_accept_queue_empty(sk)) mask |= POLLIN | POLLRDNORM; /* If there is something in the queue then we can read. */ if (transport->stream_is_active(vsk) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { bool data_ready_now = false; int ret = transport->notify_poll_in( vsk, 1, &data_ready_now); if (ret < 0) { mask |= POLLERR; } else { if (data_ready_now) mask |= POLLIN | POLLRDNORM; } } /* Sockets whose connections have been closed, reset, or * terminated should also be considered read, and we check the * shutdown flag for that. */ if (sk->sk_shutdown & RCV_SHUTDOWN || vsk->peer_shutdown & SEND_SHUTDOWN) { mask |= POLLIN | POLLRDNORM; } /* Connected sockets that can produce data can be written. */ if (sk->sk_state == SS_CONNECTED) { if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { bool space_avail_now = false; int ret = transport->notify_poll_out( vsk, 1, &space_avail_now); if (ret < 0) { mask |= POLLERR; } else { if (space_avail_now) /* Remove POLLWRBAND since INET * sockets are not setting it. */ mask |= POLLOUT | POLLWRNORM; } } } /* Simulate INET socket poll behaviors, which sets * POLLOUT|POLLWRNORM when peer is closed and nothing to read, * but local send is not shutdown. */ if (sk->sk_state == SS_UNCONNECTED) { if (!(sk->sk_shutdown & SEND_SHUTDOWN)) mask |= POLLOUT | POLLWRNORM; } release_sock(sk); } return mask; } static int vsock_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, struct msghdr *msg, size_t len) { int err; struct sock *sk; struct vsock_sock *vsk; struct sockaddr_vm *remote_addr; if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; /* For now, MSG_DONTWAIT is always assumed... */ err = 0; sk = sock->sk; vsk = vsock_sk(sk); lock_sock(sk); if (!vsock_addr_bound(&vsk->local_addr)) { struct sockaddr_vm local_addr; vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); err = __vsock_bind(sk, &local_addr); if (err != 0) goto out; } /* If the provided message contains an address, use that. Otherwise * fall back on the socket's remote handle (if it has been connected). */ if (msg->msg_name && vsock_addr_cast(msg->msg_name, msg->msg_namelen, &remote_addr) == 0) { /* Ensure this address is of the right type and is a valid * destination. */ if (remote_addr->svm_cid == VMADDR_CID_ANY) remote_addr->svm_cid = transport->get_local_cid(); if (!vsock_addr_bound(remote_addr)) { err = -EINVAL; goto out; } } else if (sock->state == SS_CONNECTED) { remote_addr = &vsk->remote_addr; if (remote_addr->svm_cid == VMADDR_CID_ANY) remote_addr->svm_cid = transport->get_local_cid(); /* XXX Should connect() or this function ensure remote_addr is * bound? */ if (!vsock_addr_bound(&vsk->remote_addr)) { err = -EINVAL; goto out; } } else { err = -EINVAL; goto out; } if (!transport->dgram_allow(remote_addr->svm_cid, remote_addr->svm_port)) { err = -EINVAL; goto out; } err = transport->dgram_enqueue(vsk, remote_addr, msg->msg_iov, len); out: release_sock(sk); return err; } static int vsock_dgram_connect(struct socket *sock, struct sockaddr *addr, int addr_len, int flags) { int err; struct sock *sk; struct vsock_sock *vsk; struct sockaddr_vm *remote_addr; sk = sock->sk; vsk = vsock_sk(sk); err = vsock_addr_cast(addr, addr_len, &remote_addr); if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) { lock_sock(sk); vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); sock->state = SS_UNCONNECTED; release_sock(sk); return 0; } else if (err != 0) return -EINVAL; lock_sock(sk); if (!vsock_addr_bound(&vsk->local_addr)) { struct sockaddr_vm local_addr; vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); err = __vsock_bind(sk, &local_addr); if (err != 0) goto out; } if (!transport->dgram_allow(remote_addr->svm_cid, remote_addr->svm_port)) { err = -EINVAL; goto out; } memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr)); sock->state = SS_CONNECTED; out: release_sock(sk); return err; } static int vsock_dgram_recvmsg(struct kiocb *kiocb, struct socket *sock, struct msghdr *msg, size_t len, int flags) { return transport->dgram_dequeue(kiocb, vsock_sk(sock->sk), msg, len, flags); } static const struct proto_ops vsock_dgram_ops = { .family = PF_VSOCK, .owner = THIS_MODULE, .release = vsock_release, .bind = vsock_bind, .connect = vsock_dgram_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, .getname = vsock_getname, .poll = vsock_poll, .ioctl = sock_no_ioctl, .listen = sock_no_listen, .shutdown = vsock_shutdown, .setsockopt = sock_no_setsockopt, .getsockopt = sock_no_getsockopt, .sendmsg = vsock_dgram_sendmsg, .recvmsg = vsock_dgram_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, }; static void vsock_connect_timeout(struct work_struct *work) { struct sock *sk; struct vsock_sock *vsk; vsk = container_of(work, struct vsock_sock, dwork.work); sk = sk_vsock(vsk); lock_sock(sk); if (sk->sk_state == SS_CONNECTING && (sk->sk_shutdown != SHUTDOWN_MASK)) { sk->sk_state = SS_UNCONNECTED; sk->sk_err = ETIMEDOUT; sk->sk_error_report(sk); } release_sock(sk); sock_put(sk); } static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr, int addr_len, int flags) { int err; struct sock *sk; struct vsock_sock *vsk; struct sockaddr_vm *remote_addr; long timeout; DEFINE_WAIT(wait); err = 0; sk = sock->sk; vsk = vsock_sk(sk); lock_sock(sk); /* XXX AF_UNSPEC should make us disconnect like AF_INET. */ switch (sock->state) { case SS_CONNECTED: err = -EISCONN; goto out; case SS_DISCONNECTING: err = -EINVAL; goto out; case SS_CONNECTING: /* This continues on so we can move sock into the SS_CONNECTED * state once the connection has completed (at which point err * will be set to zero also). Otherwise, we will either wait * for the connection or return -EALREADY should this be a * non-blocking call. */ err = -EALREADY; break; default: if ((sk->sk_state == SS_LISTEN) || vsock_addr_cast(addr, addr_len, &remote_addr) != 0) { err = -EINVAL; goto out; } /* The hypervisor and well-known contexts do not have socket * endpoints. */ if (!transport->stream_allow(remote_addr->svm_cid, remote_addr->svm_port)) { err = -ENETUNREACH; goto out; } /* Set the remote address that we are connecting to. */ memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr)); /* Autobind this socket to the local address if necessary. */ if (!vsock_addr_bound(&vsk->local_addr)) { struct sockaddr_vm local_addr; vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); err = __vsock_bind(sk, &local_addr); if (err != 0) goto out; } sk->sk_state = SS_CONNECTING; err = transport->connect(vsk); if (err < 0) goto out; /* Mark sock as connecting and set the error code to in * progress in case this is a non-blocking connect. */ sock->state = SS_CONNECTING; err = -EINPROGRESS; } /* The receive path will handle all communication until we are able to * enter the connected state. Here we wait for the connection to be * completed or a notification of an error. */ timeout = vsk->connect_timeout; prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); while (sk->sk_state != SS_CONNECTED && sk->sk_err == 0) { if (flags & O_NONBLOCK) { /* If we're not going to block, we schedule a timeout * function to generate a timeout on the connection * attempt, in case the peer doesn't respond in a * timely manner. We hold on to the socket until the * timeout fires. */ sock_hold(sk); INIT_DELAYED_WORK(&vsk->dwork, vsock_connect_timeout); schedule_delayed_work(&vsk->dwork, timeout); /* Skip ahead to preserve error code set above. */ goto out_wait; } release_sock(sk); timeout = schedule_timeout(timeout); lock_sock(sk); if (signal_pending(current)) { err = sock_intr_errno(timeout); goto out_wait_error; } else if (timeout == 0) { err = -ETIMEDOUT; goto out_wait_error; } prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); } if (sk->sk_err) { err = -sk->sk_err; goto out_wait_error; } else err = 0; out_wait: finish_wait(sk_sleep(sk), &wait); out: release_sock(sk); return err; out_wait_error: sk->sk_state = SS_UNCONNECTED; sock->state = SS_UNCONNECTED; goto out_wait; } static int vsock_accept(struct socket *sock, struct socket *newsock, int flags) { struct sock *listener; int err; struct sock *connected; struct vsock_sock *vconnected; long timeout; DEFINE_WAIT(wait); err = 0; listener = sock->sk; lock_sock(listener); if (sock->type != SOCK_STREAM) { err = -EOPNOTSUPP; goto out; } if (listener->sk_state != SS_LISTEN) { err = -EINVAL; goto out; } /* Wait for children sockets to appear; these are the new sockets * created upon connection establishment. */ timeout = sock_sndtimeo(listener, flags & O_NONBLOCK); prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE); while ((connected = vsock_dequeue_accept(listener)) == NULL && listener->sk_err == 0) { release_sock(listener); timeout = schedule_timeout(timeout); lock_sock(listener); if (signal_pending(current)) { err = sock_intr_errno(timeout); goto out_wait; } else if (timeout == 0) { err = -EAGAIN; goto out_wait; } prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE); } if (listener->sk_err) err = -listener->sk_err; if (connected) { listener->sk_ack_backlog--; lock_sock(connected); vconnected = vsock_sk(connected); /* If the listener socket has received an error, then we should * reject this socket and return. Note that we simply mark the * socket rejected, drop our reference, and let the cleanup * function handle the cleanup; the fact that we found it in * the listener's accept queue guarantees that the cleanup * function hasn't run yet. */ if (err) { vconnected->rejected = true; release_sock(connected); sock_put(connected); goto out_wait; } newsock->state = SS_CONNECTED; sock_graft(connected, newsock); release_sock(connected); sock_put(connected); } out_wait: finish_wait(sk_sleep(listener), &wait); out: release_sock(listener); return err; } static int vsock_listen(struct socket *sock, int backlog) { int err; struct sock *sk; struct vsock_sock *vsk; sk = sock->sk; lock_sock(sk); if (sock->type != SOCK_STREAM) { err = -EOPNOTSUPP; goto out; } if (sock->state != SS_UNCONNECTED) { err = -EINVAL; goto out; } vsk = vsock_sk(sk); if (!vsock_addr_bound(&vsk->local_addr)) { err = -EINVAL; goto out; } sk->sk_max_ack_backlog = backlog; sk->sk_state = SS_LISTEN; err = 0; out: release_sock(sk); return err; } static int vsock_stream_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) { int err; struct sock *sk; struct vsock_sock *vsk; u64 val; if (level != AF_VSOCK) return -ENOPROTOOPT; #define COPY_IN(_v) \ do { \ if (optlen < sizeof(_v)) { \ err = -EINVAL; \ goto exit; \ } \ if (copy_from_user(&_v, optval, sizeof(_v)) != 0) { \ err = -EFAULT; \ goto exit; \ } \ } while (0) err = 0; sk = sock->sk; vsk = vsock_sk(sk); lock_sock(sk); switch (optname) { case SO_VM_SOCKETS_BUFFER_SIZE: COPY_IN(val); transport->set_buffer_size(vsk, val); break; case SO_VM_SOCKETS_BUFFER_MAX_SIZE: COPY_IN(val); transport->set_max_buffer_size(vsk, val); break; case SO_VM_SOCKETS_BUFFER_MIN_SIZE: COPY_IN(val); transport->set_min_buffer_size(vsk, val); break; case SO_VM_SOCKETS_CONNECT_TIMEOUT: { struct timeval tv; COPY_IN(tv); if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC && tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) { vsk->connect_timeout = tv.tv_sec * HZ + DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ)); if (vsk->connect_timeout == 0) vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT; } else { err = -ERANGE; } break; } default: err = -ENOPROTOOPT; break; } #undef COPY_IN exit: release_sock(sk); return err; } static int vsock_stream_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { int err; int len; struct sock *sk; struct vsock_sock *vsk; u64 val; if (level != AF_VSOCK) return -ENOPROTOOPT; err = get_user(len, optlen); if (err != 0) return err; #define COPY_OUT(_v) \ do { \ if (len < sizeof(_v)) \ return -EINVAL; \ \ len = sizeof(_v); \ if (copy_to_user(optval, &_v, len) != 0) \ return -EFAULT; \ \ } while (0) err = 0; sk = sock->sk; vsk = vsock_sk(sk); switch (optname) { case SO_VM_SOCKETS_BUFFER_SIZE: val = transport->get_buffer_size(vsk); COPY_OUT(val); break; case SO_VM_SOCKETS_BUFFER_MAX_SIZE: val = transport->get_max_buffer_size(vsk); COPY_OUT(val); break; case SO_VM_SOCKETS_BUFFER_MIN_SIZE: val = transport->get_min_buffer_size(vsk); COPY_OUT(val); break; case SO_VM_SOCKETS_CONNECT_TIMEOUT: { struct timeval tv; tv.tv_sec = vsk->connect_timeout / HZ; tv.tv_usec = (vsk->connect_timeout - tv.tv_sec * HZ) * (1000000 / HZ); COPY_OUT(tv); break; } default: return -ENOPROTOOPT; } err = put_user(len, optlen); if (err != 0) return -EFAULT; #undef COPY_OUT return 0; } static int vsock_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk; struct vsock_sock *vsk; ssize_t total_written; long timeout; int err; struct vsock_transport_send_notify_data send_data; DEFINE_WAIT(wait); sk = sock->sk; vsk = vsock_sk(sk); total_written = 0; err = 0; if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; lock_sock(sk); /* Callers should not provide a destination with stream sockets. */ if (msg->msg_namelen) { err = sk->sk_state == SS_CONNECTED ? -EISCONN : -EOPNOTSUPP; goto out; } /* Send data only if both sides are not shutdown in the direction. */ if (sk->sk_shutdown & SEND_SHUTDOWN || vsk->peer_shutdown & RCV_SHUTDOWN) { err = -EPIPE; goto out; } if (sk->sk_state != SS_CONNECTED || !vsock_addr_bound(&vsk->local_addr)) { err = -ENOTCONN; goto out; } if (!vsock_addr_bound(&vsk->remote_addr)) { err = -EDESTADDRREQ; goto out; } /* Wait for room in the produce queue to enqueue our user's data. */ timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); err = transport->notify_send_init(vsk, &send_data); if (err < 0) goto out; prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); while (total_written < len) { ssize_t written; while (vsock_stream_has_space(vsk) == 0 && sk->sk_err == 0 && !(sk->sk_shutdown & SEND_SHUTDOWN) && !(vsk->peer_shutdown & RCV_SHUTDOWN)) { /* Don't wait for non-blocking sockets. */ if (timeout == 0) { err = -EAGAIN; goto out_wait; } err = transport->notify_send_pre_block(vsk, &send_data); if (err < 0) goto out_wait; release_sock(sk); timeout = schedule_timeout(timeout); lock_sock(sk); if (signal_pending(current)) { err = sock_intr_errno(timeout); goto out_wait; } else if (timeout == 0) { err = -EAGAIN; goto out_wait; } prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); } /* These checks occur both as part of and after the loop * conditional since we need to check before and after * sleeping. */ if (sk->sk_err) { err = -sk->sk_err; goto out_wait; } else if ((sk->sk_shutdown & SEND_SHUTDOWN) || (vsk->peer_shutdown & RCV_SHUTDOWN)) { err = -EPIPE; goto out_wait; } err = transport->notify_send_pre_enqueue(vsk, &send_data); if (err < 0) goto out_wait; /* Note that enqueue will only write as many bytes as are free * in the produce queue, so we don't need to ensure len is * smaller than the queue size. It is the caller's * responsibility to check how many bytes we were able to send. */ written = transport->stream_enqueue( vsk, msg->msg_iov, len - total_written); if (written < 0) { err = -ENOMEM; goto out_wait; } total_written += written; err = transport->notify_send_post_enqueue( vsk, written, &send_data); if (err < 0) goto out_wait; } out_wait: if (total_written > 0) err = total_written; finish_wait(sk_sleep(sk), &wait); out: release_sock(sk); return err; } static int vsock_stream_recvmsg(struct kiocb *kiocb, struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct sock *sk; struct vsock_sock *vsk; int err; size_t target; ssize_t copied; long timeout; struct vsock_transport_recv_notify_data recv_data; DEFINE_WAIT(wait); sk = sock->sk; vsk = vsock_sk(sk); err = 0; lock_sock(sk); if (sk->sk_state != SS_CONNECTED) { /* Recvmsg is supposed to return 0 if a peer performs an * orderly shutdown. Differentiate between that case and when a * peer has not connected or a local shutdown occured with the * SOCK_DONE flag. */ if (sock_flag(sk, SOCK_DONE)) err = 0; else err = -ENOTCONN; goto out; } if (flags & MSG_OOB) { err = -EOPNOTSUPP; goto out; } /* We don't check peer_shutdown flag here since peer may actually shut * down, but there can be data in the queue that a local socket can * receive. */ if (sk->sk_shutdown & RCV_SHUTDOWN) { err = 0; goto out; } /* It is valid on Linux to pass in a zero-length receive buffer. This * is not an error. We may as well bail out now. */ if (!len) { err = 0; goto out; } /* We must not copy less than target bytes into the user's buffer * before returning successfully, so we wait for the consume queue to * have that much data to consume before dequeueing. Note that this * makes it impossible to handle cases where target is greater than the * queue size. */ target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); if (target >= transport->stream_rcvhiwat(vsk)) { err = -ENOMEM; goto out; } timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); copied = 0; err = transport->notify_recv_init(vsk, target, &recv_data); if (err < 0) goto out; prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); while (1) { s64 ready = vsock_stream_has_data(vsk); if (ready < 0) { /* Invalid queue pair content. XXX This should be * changed to a connection reset in a later change. */ err = -ENOMEM; goto out_wait; } else if (ready > 0) { ssize_t read; err = transport->notify_recv_pre_dequeue( vsk, target, &recv_data); if (err < 0) break; read = transport->stream_dequeue( vsk, msg->msg_iov, len - copied, flags); if (read < 0) { err = -ENOMEM; break; } copied += read; err = transport->notify_recv_post_dequeue( vsk, target, read, !(flags & MSG_PEEK), &recv_data); if (err < 0) goto out_wait; if (read >= target || flags & MSG_PEEK) break; target -= read; } else { if (sk->sk_err != 0 || (sk->sk_shutdown & RCV_SHUTDOWN) || (vsk->peer_shutdown & SEND_SHUTDOWN)) { break; } /* Don't wait for non-blocking sockets. */ if (timeout == 0) { err = -EAGAIN; break; } err = transport->notify_recv_pre_block( vsk, target, &recv_data); if (err < 0) break; release_sock(sk); timeout = schedule_timeout(timeout); lock_sock(sk); if (signal_pending(current)) { err = sock_intr_errno(timeout); break; } else if (timeout == 0) { err = -EAGAIN; break; } prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); } } if (sk->sk_err) err = -sk->sk_err; else if (sk->sk_shutdown & RCV_SHUTDOWN) err = 0; if (copied > 0) err = copied; out_wait: finish_wait(sk_sleep(sk), &wait); out: release_sock(sk); return err; } static const struct proto_ops vsock_stream_ops = { .family = PF_VSOCK, .owner = THIS_MODULE, .release = vsock_release, .bind = vsock_bind, .connect = vsock_stream_connect, .socketpair = sock_no_socketpair, .accept = vsock_accept, .getname = vsock_getname, .poll = vsock_poll, .ioctl = sock_no_ioctl, .listen = vsock_listen, .shutdown = vsock_shutdown, .setsockopt = vsock_stream_setsockopt, .getsockopt = vsock_stream_getsockopt, .sendmsg = vsock_stream_sendmsg, .recvmsg = vsock_stream_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, }; static int vsock_create(struct net *net, struct socket *sock, int protocol, int kern) { if (!sock) return -EINVAL; if (protocol && protocol != PF_VSOCK) return -EPROTONOSUPPORT; switch (sock->type) { case SOCK_DGRAM: sock->ops = &vsock_dgram_ops; break; case SOCK_STREAM: sock->ops = &vsock_stream_ops; break; default: return -ESOCKTNOSUPPORT; } sock->state = SS_UNCONNECTED; return __vsock_create(net, sock, NULL, GFP_KERNEL, 0) ? 0 : -ENOMEM; } static const struct net_proto_family vsock_family_ops = { .family = AF_VSOCK, .create = vsock_create, .owner = THIS_MODULE, }; static long vsock_dev_do_ioctl(struct file *filp, unsigned int cmd, void __user *ptr) { u32 __user *p = ptr; int retval = 0; switch (cmd) { case IOCTL_VM_SOCKETS_GET_LOCAL_CID: if (put_user(transport->get_local_cid(), p) != 0) retval = -EFAULT; break; default: pr_err("Unknown ioctl %d\n", cmd); retval = -EINVAL; } return retval; } static long vsock_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg); } #ifdef CONFIG_COMPAT static long vsock_dev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg)); } #endif static const struct file_operations vsock_device_ops = { .owner = THIS_MODULE, .unlocked_ioctl = vsock_dev_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = vsock_dev_compat_ioctl, #endif .open = nonseekable_open, }; static struct miscdevice vsock_device = { .name = "vsock", .fops = &vsock_device_ops, }; static int __vsock_core_init(void) { int err; vsock_init_tables(); vsock_device.minor = MISC_DYNAMIC_MINOR; err = misc_register(&vsock_device); if (err) { pr_err("Failed to register misc device\n"); return -ENOENT; } err = proto_register(&vsock_proto, 1); /* we want our slab */ if (err) { pr_err("Cannot register vsock protocol\n"); goto err_misc_deregister; } err = sock_register(&vsock_family_ops); if (err) { pr_err("could not register af_vsock (%d) address family: %d\n", AF_VSOCK, err); goto err_unregister_proto; } return 0; err_unregister_proto: proto_unregister(&vsock_proto); err_misc_deregister: misc_deregister(&vsock_device); return err; } int vsock_core_init(const struct vsock_transport *t) { int retval = mutex_lock_interruptible(&vsock_register_mutex); if (retval) return retval; if (transport) { retval = -EBUSY; goto out; } transport = t; retval = __vsock_core_init(); if (retval) transport = NULL; out: mutex_unlock(&vsock_register_mutex); return retval; } EXPORT_SYMBOL_GPL(vsock_core_init); void vsock_core_exit(void) { mutex_lock(&vsock_register_mutex); misc_deregister(&vsock_device); sock_unregister(AF_VSOCK); proto_unregister(&vsock_proto); /* We do not want the assignment below re-ordered. */ mb(); transport = NULL; mutex_unlock(&vsock_register_mutex); } EXPORT_SYMBOL_GPL(vsock_core_exit); MODULE_AUTHOR("VMware, Inc."); MODULE_DESCRIPTION("VMware Virtual Socket Family"); MODULE_VERSION("1.0.0.0-k"); MODULE_LICENSE("GPL v2");