diff options
Diffstat (limited to 'net/vmw_vsock/af_vsock.c')
| -rw-r--r-- | net/vmw_vsock/af_vsock.c | 2025 |
1 files changed, 2025 insertions, 0 deletions
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c new file mode 100644 index 000000000..22931a5f6 --- /dev/null +++ b/net/vmw_vsock/af_vsock.c @@ -0,0 +1,2025 @@ +/* + * 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 TCP_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. + * + * - Lock ordering for pending or accept queue sockets is: + * + * lock_sock(listener); + * lock_sock_nested(pending, SINGLE_DEPTH_NESTING); + * + * Using explicit nested locking keeps lockdep happy since normally only one + * lock of a given class may be taken at a time. + * + * - 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. + * + * - sk->sk_state uses the TCP state constants because they are widely used by + * other address families and exposed to userspace tools like ss(8): + * + * TCP_CLOSE - unconnected + * TCP_SYN_SENT - connecting + * TCP_ESTABLISHED - connected + * TCP_CLOSING - disconnecting + * TCP_LISTEN - listening + */ + +#include <linux/types.h> +#include <linux/bitops.h> +#include <linux/cred.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/kmod.h> +#include <linux/list.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/net.h> +#include <linux/poll.h> +#include <linux/random.h> +#include <linux/skbuff.h> +#include <linux/smp.h> +#include <linux/socket.h> +#include <linux/stddef.h> +#include <linux/unistd.h> +#include <linux/wait.h> +#include <linux/workqueue.h> +#include <net/sock.h> +#include <net/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) + +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 to ensure this. + */ +#define MAX_PORT_RETRIES 24 + +#define VSOCK_HASH(addr) ((addr)->svm_port % VSOCK_HASH_SIZE) +#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) +#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) + +struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1]; +EXPORT_SYMBOL_GPL(vsock_bind_table); +struct list_head vsock_connected_table[VSOCK_HASH_SIZE]; +EXPORT_SYMBOL_GPL(vsock_connected_table); +DEFINE_SPINLOCK(vsock_table_lock); +EXPORT_SYMBOL_GPL(vsock_table_lock); + +/* Autobind this socket to the local address if necessary. */ +static int vsock_auto_bind(struct vsock_sock *vsk) +{ + struct sock *sk = sk_vsock(vsk); + struct sockaddr_vm local_addr; + + if (vsock_addr_bound(&vsk->local_addr)) + return 0; + vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); + return __vsock_bind(sk, &local_addr); +} + +static int __init 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]); + return 0; +} + +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 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); + if (__vsock_in_bound_table(vsk)) + __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); + if (__vsock_in_connected_table(vsk)) + __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); + +void vsock_remove_sock(struct vsock_sock *vsk) +{ + vsock_remove_bound(vsk); + vsock_remove_connected(vsk); +} +EXPORT_SYMBOL_GPL(vsock_remove_sock); + +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); +} + +static 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, pending_work.work); + sk = sk_vsock(vsk); + listener = vsk->listener; + cleanup = true; + + lock_sock(listener); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); + + if (vsock_is_pending(sk)) { + vsock_remove_pending(listener, sk); + + listener->sk_ack_backlog--; + } 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; + } + + /* 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. + */ + vsock_remove_connected(vsk); + + sk->sk_state = TCP_CLOSE; + +out: + release_sock(sk); + release_sock(listener); + if (cleanup) + sock_put(sk); + + sock_put(sk); + sock_put(listener); +} + +/**** SOCKET OPERATIONS ****/ + +static int __vsock_bind_stream(struct vsock_sock *vsk, + struct sockaddr_vm *addr) +{ + static u32 port = 0; + struct sockaddr_vm new_addr; + + if (!port) + port = LAST_RESERVED_PORT + 1 + + prandom_u32_max(U32_MAX - LAST_RESERVED_PORT); + + 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; +} + +static void vsock_connect_timeout(struct work_struct *work); + +struct sock *__vsock_create(struct net *net, + struct socket *sock, + struct sock *parent, + gfp_t priority, + unsigned short type, + int kern) +{ + struct sock *sk; + struct vsock_sock *psk; + struct vsock_sock *vsk; + + sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern); + 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; + 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; + INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout); + INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work); + + psk = parent ? vsock_sk(parent) : NULL; + if (parent) { + vsk->trusted = psk->trusted; + vsk->owner = get_cred(psk->owner); + vsk->connect_timeout = psk->connect_timeout; + security_sk_clone(parent, sk); + } else { + vsk->trusted = ns_capable_noaudit(&init_user_ns, 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, int level) +{ + if (sk) { + struct sk_buff *skb; + struct sock *pending; + struct vsock_sock *vsk; + + vsk = vsock_sk(sk); + pending = NULL; /* Compiler warning. */ + + /* The release call is supposed to use lock_sock_nested() + * rather than lock_sock(), if a sock lock should be acquired. + */ + transport->release(vsk); + + /* When "level" is SINGLE_DEPTH_NESTING, use the nested + * version to avoid the warning "possible recursive locking + * detected". When "level" is 0, lock_sock_nested(sk, level) + * is the same as lock_sock(sk). + */ + lock_sock_nested(sk, level); + 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, SINGLE_DEPTH_NESTING); + 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, 0); + 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 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)); + err = 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; + + lock_sock(sk); + if (sock->state == SS_UNCONNECTED) { + err = -ENOTCONN; + if (sk->sk_type == SOCK_STREAM) + goto out; + } else { + sock->state = SS_DISCONNECTING; + err = 0; + } + + /* Receive and send shutdowns are treated alike. */ + mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN); + if (mode) { + sk->sk_shutdown |= mode; + sk->sk_state_change(sk); + + if (sk->sk_type == SOCK_STREAM) { + sock_reset_flag(sk, SOCK_DONE); + vsock_send_shutdown(sk, mode); + } + } + +out: + release_sock(sk); + return err; +} + +static __poll_t vsock_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk; + __poll_t 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 |= EPOLLERR; + + /* INET sockets treat local write shutdown and peer write shutdown as a + * case of EPOLLHUP set. + */ + if ((sk->sk_shutdown == SHUTDOWN_MASK) || + ((sk->sk_shutdown & SEND_SHUTDOWN) && + (vsk->peer_shutdown & SEND_SHUTDOWN))) { + mask |= EPOLLHUP; + } + + if (sk->sk_shutdown & RCV_SHUTDOWN || + vsk->peer_shutdown & SEND_SHUTDOWN) { + mask |= EPOLLRDHUP; + } + + 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_lockless(&sk->sk_receive_queue) || + (sk->sk_shutdown & RCV_SHUTDOWN)) { + mask |= EPOLLIN | EPOLLRDNORM; + } + + if (!(sk->sk_shutdown & SEND_SHUTDOWN)) + mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; + + } 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 == TCP_LISTEN + && !vsock_is_accept_queue_empty(sk)) + mask |= EPOLLIN | EPOLLRDNORM; + + /* 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 |= EPOLLERR; + } else { + if (data_ready_now) + mask |= EPOLLIN | EPOLLRDNORM; + + } + } + + /* 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 |= EPOLLIN | EPOLLRDNORM; + } + + /* Connected sockets that can produce data can be written. */ + if (sk->sk_state == TCP_ESTABLISHED) { + 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 |= EPOLLERR; + } else { + if (space_avail_now) + /* Remove EPOLLWRBAND since INET + * sockets are not setting it. + */ + mask |= EPOLLOUT | EPOLLWRNORM; + + } + } + } + + /* Simulate INET socket poll behaviors, which sets + * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read, + * but local send is not shutdown. + */ + if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) { + if (!(sk->sk_shutdown & SEND_SHUTDOWN)) + mask |= EPOLLOUT | EPOLLWRNORM; + + } + + release_sock(sk); + } + + return mask; +} + +static int vsock_dgram_sendmsg(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); + + err = vsock_auto_bind(vsk); + if (err) + 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, 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); + + err = vsock_auto_bind(vsk); + if (err) + 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 socket *sock, struct msghdr *msg, + size_t len, int flags) +{ + return transport->dgram_dequeue(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 int vsock_transport_cancel_pkt(struct vsock_sock *vsk) +{ + if (!transport->cancel_pkt) + return -EOPNOTSUPP; + + return transport->cancel_pkt(vsk); +} + +static void vsock_connect_timeout(struct work_struct *work) +{ + struct sock *sk; + struct vsock_sock *vsk; + + vsk = container_of(work, struct vsock_sock, connect_work.work); + sk = sk_vsock(vsk); + + lock_sock(sk); + if (sk->sk_state == TCP_SYN_SENT && + (sk->sk_shutdown != SHUTDOWN_MASK)) { + sk->sk_state = TCP_CLOSE; + sk->sk_err = ETIMEDOUT; + sk->sk_error_report(sk); + vsock_transport_cancel_pkt(vsk); + } + 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; + if (flags & O_NONBLOCK) + goto out; + break; + default: + if ((sk->sk_state == TCP_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)); + + err = vsock_auto_bind(vsk); + if (err) + goto out; + + sk->sk_state = TCP_SYN_SENT; + + 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 != TCP_ESTABLISHED && 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); + schedule_delayed_work(&vsk->connect_work, 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); + sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE; + sock->state = SS_UNCONNECTED; + vsock_transport_cancel_pkt(vsk); + vsock_remove_connected(vsk); + goto out_wait; + } else if (timeout == 0) { + err = -ETIMEDOUT; + sk->sk_state = TCP_CLOSE; + sock->state = SS_UNCONNECTED; + vsock_transport_cancel_pkt(vsk); + goto out_wait; + } + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + } + + if (sk->sk_err) { + err = -sk->sk_err; + sk->sk_state = TCP_CLOSE; + sock->state = SS_UNCONNECTED; + } else { + err = 0; + } + +out_wait: + finish_wait(sk_sleep(sk), &wait); +out: + release_sock(sk); + return err; +} + +static int vsock_accept(struct socket *sock, struct socket *newsock, int flags, + bool kern) +{ + 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 != TCP_LISTEN) { + err = -EINVAL; + goto out; + } + + /* Wait for children sockets to appear; these are the new sockets + * created upon connection establishment. + */ + timeout = sock_rcvtimeo(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); + finish_wait(sk_sleep(listener), &wait); + lock_sock(listener); + + if (signal_pending(current)) { + err = sock_intr_errno(timeout); + goto out; + } else if (timeout == 0) { + err = -EAGAIN; + goto out; + } + + prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE); + } + finish_wait(sk_sleep(listener), &wait); + + if (listener->sk_err) + err = -listener->sk_err; + + if (connected) { + listener->sk_ack_backlog--; + + lock_sock_nested(connected, SINGLE_DEPTH_NESTING); + 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; + } else { + newsock->state = SS_CONNECTED; + sock_graft(connected, newsock); + } + + release_sock(connected); + sock_put(connected); + } + +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 = TCP_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 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_FUNC(wait, woken_wake_function); + + 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 == TCP_ESTABLISHED ? -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 != TCP_ESTABLISHED || + !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; + + while (total_written < len) { + ssize_t written; + + add_wait_queue(sk_sleep(sk), &wait); + 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; + remove_wait_queue(sk_sleep(sk), &wait); + goto out_err; + } + + err = transport->notify_send_pre_block(vsk, &send_data); + if (err < 0) { + remove_wait_queue(sk_sleep(sk), &wait); + goto out_err; + } + + release_sock(sk); + timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); + lock_sock(sk); + if (signal_pending(current)) { + err = sock_intr_errno(timeout); + remove_wait_queue(sk_sleep(sk), &wait); + goto out_err; + } else if (timeout == 0) { + err = -EAGAIN; + remove_wait_queue(sk_sleep(sk), &wait); + goto out_err; + } + } + remove_wait_queue(sk_sleep(sk), &wait); + + /* 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_err; + } else if ((sk->sk_shutdown & SEND_SHUTDOWN) || + (vsk->peer_shutdown & RCV_SHUTDOWN)) { + err = -EPIPE; + goto out_err; + } + + err = transport->notify_send_pre_enqueue(vsk, &send_data); + if (err < 0) + goto out_err; + + /* 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, + len - total_written); + if (written < 0) { + err = -ENOMEM; + goto out_err; + } + + total_written += written; + + err = transport->notify_send_post_enqueue( + vsk, written, &send_data); + if (err < 0) + goto out_err; + + } + +out_err: + if (total_written > 0) + err = total_written; +out: + release_sock(sk); + return err; +} + + +static int +vsock_stream_recvmsg(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 != TCP_ESTABLISHED) { + /* 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; + + + while (1) { + s64 ready; + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + ready = vsock_stream_has_data(vsk); + + if (ready == 0) { + if (sk->sk_err != 0 || + (sk->sk_shutdown & RCV_SHUTDOWN) || + (vsk->peer_shutdown & SEND_SHUTDOWN)) { + finish_wait(sk_sleep(sk), &wait); + break; + } + /* Don't wait for non-blocking sockets. */ + if (timeout == 0) { + err = -EAGAIN; + finish_wait(sk_sleep(sk), &wait); + break; + } + + err = transport->notify_recv_pre_block( + vsk, target, &recv_data); + if (err < 0) { + finish_wait(sk_sleep(sk), &wait); + break; + } + release_sock(sk); + timeout = schedule_timeout(timeout); + lock_sock(sk); + + if (signal_pending(current)) { + err = sock_intr_errno(timeout); + finish_wait(sk_sleep(sk), &wait); + break; + } else if (timeout == 0) { + err = -EAGAIN; + finish_wait(sk_sleep(sk), &wait); + break; + } + } else { + ssize_t read; + + finish_wait(sk_sleep(sk), &wait); + + if (ready < 0) { + /* Invalid queue pair content. XXX This should + * be changed to a connection reset in a later + * change. + */ + + err = -ENOMEM; + goto out; + } + + err = transport->notify_recv_pre_dequeue( + vsk, target, &recv_data); + if (err < 0) + break; + + read = transport->stream_dequeue( + vsk, msg, + 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; + + if (read >= target || flags & MSG_PEEK) + break; + + target -= read; + } + } + + if (sk->sk_err) + err = -sk->sk_err; + else if (sk->sk_shutdown & RCV_SHUTDOWN) + err = 0; + + if (copied > 0) + err = copied; + +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, kern) ? 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, +}; + +int __vsock_core_init(const struct vsock_transport *t, struct module *owner) +{ + int err = mutex_lock_interruptible(&vsock_register_mutex); + + if (err) + return err; + + if (transport) { + err = -EBUSY; + goto err_busy; + } + + /* Transport must be the owner of the protocol so that it can't + * unload while there are open sockets. + */ + vsock_proto.owner = owner; + transport = t; + + vsock_device.minor = MISC_DYNAMIC_MINOR; + err = misc_register(&vsock_device); + if (err) { + pr_err("Failed to register misc device\n"); + goto err_reset_transport; + } + + err = proto_register(&vsock_proto, 1); /* we want our slab */ + if (err) { + pr_err("Cannot register vsock protocol\n"); + goto err_deregister_misc; + } + + 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; + } + + mutex_unlock(&vsock_register_mutex); + return 0; + +err_unregister_proto: + proto_unregister(&vsock_proto); +err_deregister_misc: + misc_deregister(&vsock_device); +err_reset_transport: + transport = NULL; +err_busy: + mutex_unlock(&vsock_register_mutex); + return err; +} +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); + +const struct vsock_transport *vsock_core_get_transport(void) +{ + /* vsock_register_mutex not taken since only the transport uses this + * function and only while registered. + */ + return transport; +} +EXPORT_SYMBOL_GPL(vsock_core_get_transport); + +static void __exit vsock_exit(void) +{ + /* Do nothing. This function makes this module removable. */ +} + +module_init(vsock_init_tables); +module_exit(vsock_exit); + +MODULE_AUTHOR("VMware, Inc."); +MODULE_DESCRIPTION("VMware Virtual Socket Family"); +MODULE_VERSION("1.0.2.0-k"); +MODULE_LICENSE("GPL v2"); |