net/vmw_vsock/af_vsock.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VMware vSockets Driver
   4  *
   5  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
   6  */
   7
   8 /* Implementation notes:
   9  *
  10  * - There are two kinds of sockets: those created by user action (such as
  11  * calling socket(2)) and those created by incoming connection request packets.
  12  *
  13  * - There are two "global" tables, one for bound sockets (sockets that have
  14  * specified an address that they are responsible for) and one for connected
  15  * sockets (sockets that have established a connection with another socket).
  16  * These tables are "global" in that all sockets on the system are placed
  17  * within them. - Note, though, that the bound table contains an extra entry
  18  * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
  19  * that list. The bound table is used solely for lookup of sockets when packets
  20  * are received and that's not necessary for SOCK_DGRAM sockets since we create
  21  * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
  22  * sockets out of the bound hash buckets will reduce the chance of collisions
  23  * when looking for SOCK_STREAM sockets and prevents us from having to check the
  24  * socket type in the hash table lookups.
  25  *
  26  * - Sockets created by user action will either be "client" sockets that
  27  * initiate a connection or "server" sockets that listen for connections; we do
  28  * not support simultaneous connects (two "client" sockets connecting).
  29  *
  30  * - "Server" sockets are referred to as listener sockets throughout this
  31  * implementation because they are in the TCP_LISTEN state.  When a
  32  * connection request is received (the second kind of socket mentioned above),
  33  * we create a new socket and refer to it as a pending socket.  These pending
  34  * sockets are placed on the pending connection list of the listener socket.
  35  * When future packets are received for the address the listener socket is
  36  * bound to, we check if the source of the packet is from one that has an
  37  * existing pending connection.  If it does, we process the packet for the
  38  * pending socket.  When that socket reaches the connected state, it is removed
  39  * from the listener socket's pending list and enqueued in the listener
  40  * socket's accept queue.  Callers of accept(2) will accept connected sockets
  41  * from the listener socket's accept queue.  If the socket cannot be accepted
  42  * for some reason then it is marked rejected.  Once the connection is
  43  * accepted, it is owned by the user process and the responsibility for cleanup
  44  * falls with that user process.
  45  *
  46  * - It is possible that these pending sockets will never reach the connected
  47  * state; in fact, we may never receive another packet after the connection
  48  * request.  Because of this, we must schedule a cleanup function to run in the
  49  * future, after some amount of time passes where a connection should have been
  50  * established.  This function ensures that the socket is off all lists so it
  51  * cannot be retrieved, then drops all references to the socket so it is cleaned
  52  * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
  53  * function will also cleanup rejected sockets, those that reach the connected
  54  * state but leave it before they have been accepted.
  55  *
  56  * - Lock ordering for pending or accept queue sockets is:
  57  *
  58  *     lock_sock(listener);
  59  *     lock_sock_nested(pending, SINGLE_DEPTH_NESTING);
  60  *
  61  * Using explicit nested locking keeps lockdep happy since normally only one
  62  * lock of a given class may be taken at a time.
  63  *
  64  * - Sockets created by user action will be cleaned up when the user process
  65  * calls close(2), causing our release implementation to be called. Our release
  66  * implementation will perform some cleanup then drop the last reference so our
  67  * sk_destruct implementation is invoked.  Our sk_destruct implementation will
  68  * perform additional cleanup that's common for both types of sockets.
  69  *
  70  * - A socket's reference count is what ensures that the structure won't be
  71  * freed.  Each entry in a list (such as the "global" bound and connected tables
  72  * and the listener socket's pending list and connected queue) ensures a
  73  * reference.  When we defer work until process context and pass a socket as our
  74  * argument, we must ensure the reference count is increased to ensure the
  75  * socket isn't freed before the function is run; the deferred function will
  76  * then drop the reference.
  77  *
  78  * - sk->sk_state uses the TCP state constants because they are widely used by
  79  * other address families and exposed to userspace tools like ss(8):
  80  *
  81  *   TCP_CLOSE - unconnected
  82  *   TCP_SYN_SENT - connecting
  83  *   TCP_ESTABLISHED - connected
  84  *   TCP_CLOSING - disconnecting
  85  *   TCP_LISTEN - listening
  86  */
  87
  88 #include <linux/types.h>
  89 #include <linux/bitops.h>
  90 #include <linux/cred.h>
  91 #include <linux/init.h>
  92 #include <linux/io.h>
  93 #include <linux/kernel.h>
  94 #include <linux/sched/signal.h>
  95 #include <linux/kmod.h>
  96 #include <linux/list.h>
  97 #include <linux/miscdevice.h>
  98 #include <linux/module.h>
  99 #include <linux/mutex.h>
 100 #include <linux/net.h>
 101 #include <linux/poll.h>
 102 #include <linux/random.h>
 103 #include <linux/skbuff.h>
 104 #include <linux/smp.h>
 105 #include <linux/socket.h>
 106 #include <linux/stddef.h>
 107 #include <linux/unistd.h>
 108 #include <linux/wait.h>
 109 #include <linux/workqueue.h>
 110 #include <net/sock.h>
 111 #include <net/af_vsock.h>
 112
 113 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 114 static void vsock_sk_destruct(struct sock *sk);
 115 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 116
 117 /* Protocol family. */
 118 static struct proto vsock_proto = {
 119         .name = "AF_VSOCK",
 120         .owner = THIS_MODULE,
 121         .obj_size = sizeof(struct vsock_sock),
 122 };
 123
 124 /* The default peer timeout indicates how long we will wait for a peer response
 125  * to a control message.
 126  */
 127 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
 128
 129 static const struct vsock_transport *transport;
 130 static DEFINE_MUTEX(vsock_register_mutex);
 131
 132 /**** EXPORTS ****/
 133
 134 /* Get the ID of the local context.  This is transport dependent. */
 135
 136 int vm_sockets_get_local_cid(void)
 137 {
 138         return transport->get_local_cid();
 139 }
 140 EXPORT_SYMBOL_GPL(vm_sockets_get_local_cid);
 141
 142 /**** UTILS ****/
 143
 144 /* Each bound VSocket is stored in the bind hash table and each connected
 145  * VSocket is stored in the connected hash table.
 146  *
 147  * Unbound sockets are all put on the same list attached to the end of the hash
 148  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
 149  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
 150  * represents the list that addr hashes to).
 151  *
 152  * Specifically, we initialize the vsock_bind_table array to a size of
 153  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
 154  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
 155  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
 156  * mods with VSOCK_HASH_SIZE to ensure this.
 157  */
 158 #define MAX_PORT_RETRIES        24
 159
 160 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
 161 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
 162 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
 163
 164 /* XXX This can probably be implemented in a better way. */
 165 #define VSOCK_CONN_HASH(src, dst)                               \
 166         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
 167 #define vsock_connected_sockets(src, dst)               \
 168         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
 169 #define vsock_connected_sockets_vsk(vsk)                                \
 170         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
 171
 172 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
 173 EXPORT_SYMBOL_GPL(vsock_bind_table);
 174 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
 175 EXPORT_SYMBOL_GPL(vsock_connected_table);
 176 DEFINE_SPINLOCK(vsock_table_lock);
 177 EXPORT_SYMBOL_GPL(vsock_table_lock);
 178
 179 /* Autobind this socket to the local address if necessary. */
 180 static int vsock_auto_bind(struct vsock_sock *vsk)
 181 {
 182         struct sock *sk = sk_vsock(vsk);
 183         struct sockaddr_vm local_addr;
 184
 185         if (vsock_addr_bound(&vsk->local_addr))
 186                 return 0;
 187         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 188         return __vsock_bind(sk, &local_addr);
 189 }
 190
 191 static int __init vsock_init_tables(void)
 192 {
 193         int i;
 194
 195         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
 196                 INIT_LIST_HEAD(&vsock_bind_table[i]);
 197
 198         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
 199                 INIT_LIST_HEAD(&vsock_connected_table[i]);
 200         return 0;
 201 }
 202
 203 static void __vsock_insert_bound(struct list_head *list,
 204                                  struct vsock_sock *vsk)
 205 {
 206         sock_hold(&vsk->sk);
 207         list_add(&vsk->bound_table, list);
 208 }
 209
 210 static void __vsock_insert_connected(struct list_head *list,
 211                                      struct vsock_sock *vsk)
 212 {
 213         sock_hold(&vsk->sk);
 214         list_add(&vsk->connected_table, list);
 215 }
 216
 217 static void __vsock_remove_bound(struct vsock_sock *vsk)
 218 {
 219         list_del_init(&vsk->bound_table);
 220         sock_put(&vsk->sk);
 221 }
 222
 223 static void __vsock_remove_connected(struct vsock_sock *vsk)
 224 {
 225         list_del_init(&vsk->connected_table);
 226         sock_put(&vsk->sk);
 227 }
 228
 229 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
 230 {
 231         struct vsock_sock *vsk;
 232
 233         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table)
 234                 if (addr->svm_port == vsk->local_addr.svm_port)
 235                         return sk_vsock(vsk);
 236
 237         return NULL;
 238 }
 239
 240 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
 241                                                   struct sockaddr_vm *dst)
 242 {
 243         struct vsock_sock *vsk;
 244
 245         list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
 246                             connected_table) {
 247                 if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
 248                     dst->svm_port == vsk->local_addr.svm_port) {
 249                         return sk_vsock(vsk);
 250                 }
 251         }
 252
 253         return NULL;
 254 }
 255
 256 static void vsock_insert_unbound(struct vsock_sock *vsk)
 257 {
 258         spin_lock_bh(&vsock_table_lock);
 259         __vsock_insert_bound(vsock_unbound_sockets, vsk);
 260         spin_unlock_bh(&vsock_table_lock);
 261 }
 262
 263 void vsock_insert_connected(struct vsock_sock *vsk)
 264 {
 265         struct list_head *list = vsock_connected_sockets(
 266                 &vsk->remote_addr, &vsk->local_addr);
 267
 268         spin_lock_bh(&vsock_table_lock);
 269         __vsock_insert_connected(list, vsk);
 270         spin_unlock_bh(&vsock_table_lock);
 271 }
 272 EXPORT_SYMBOL_GPL(vsock_insert_connected);
 273
 274 void vsock_remove_bound(struct vsock_sock *vsk)
 275 {
 276         spin_lock_bh(&vsock_table_lock);
 277         __vsock_remove_bound(vsk);
 278         spin_unlock_bh(&vsock_table_lock);
 279 }
 280 EXPORT_SYMBOL_GPL(vsock_remove_bound);
 281
 282 void vsock_remove_connected(struct vsock_sock *vsk)
 283 {
 284         spin_lock_bh(&vsock_table_lock);
 285         __vsock_remove_connected(vsk);
 286         spin_unlock_bh(&vsock_table_lock);
 287 }
 288 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 289
 290 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 291 {
 292         struct sock *sk;
 293
 294         spin_lock_bh(&vsock_table_lock);
 295         sk = __vsock_find_bound_socket(addr);
 296         if (sk)
 297                 sock_hold(sk);
 298
 299         spin_unlock_bh(&vsock_table_lock);
 300
 301         return sk;
 302 }
 303 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 304
 305 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 306                                          struct sockaddr_vm *dst)
 307 {
 308         struct sock *sk;
 309
 310         spin_lock_bh(&vsock_table_lock);
 311         sk = __vsock_find_connected_socket(src, dst);
 312         if (sk)
 313                 sock_hold(sk);
 314
 315         spin_unlock_bh(&vsock_table_lock);
 316
 317         return sk;
 318 }
 319 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 320
 321 static bool vsock_in_bound_table(struct vsock_sock *vsk)
 322 {
 323         bool ret;
 324
 325         spin_lock_bh(&vsock_table_lock);
 326         ret = __vsock_in_bound_table(vsk);
 327         spin_unlock_bh(&vsock_table_lock);
 328
 329         return ret;
 330 }
 331
 332 static bool vsock_in_connected_table(struct vsock_sock *vsk)
 333 {
 334         bool ret;
 335
 336         spin_lock_bh(&vsock_table_lock);
 337         ret = __vsock_in_connected_table(vsk);
 338         spin_unlock_bh(&vsock_table_lock);
 339
 340         return ret;
 341 }
 342
 343 void vsock_remove_sock(struct vsock_sock *vsk)
 344 {
 345         if (vsock_in_bound_table(vsk))
 346                 vsock_remove_bound(vsk);
 347
 348         if (vsock_in_connected_table(vsk))
 349                 vsock_remove_connected(vsk);
 350 }
 351 EXPORT_SYMBOL_GPL(vsock_remove_sock);
 352
 353 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
 354 {
 355         int i;
 356
 357         spin_lock_bh(&vsock_table_lock);
 358
 359         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
 360                 struct vsock_sock *vsk;
 361                 list_for_each_entry(vsk, &vsock_connected_table[i],
 362                                     connected_table)
 363                         fn(sk_vsock(vsk));
 364         }
 365
 366         spin_unlock_bh(&vsock_table_lock);
 367 }
 368 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
 369
 370 void vsock_add_pending(struct sock *listener, struct sock *pending)
 371 {
 372         struct vsock_sock *vlistener;
 373         struct vsock_sock *vpending;
 374
 375         vlistener = vsock_sk(listener);
 376         vpending = vsock_sk(pending);
 377
 378         sock_hold(pending);
 379         sock_hold(listener);
 380         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 381 }
 382 EXPORT_SYMBOL_GPL(vsock_add_pending);
 383
 384 void vsock_remove_pending(struct sock *listener, struct sock *pending)
 385 {
 386         struct vsock_sock *vpending = vsock_sk(pending);
 387
 388         list_del_init(&vpending->pending_links);
 389         sock_put(listener);
 390         sock_put(pending);
 391 }
 392 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 393
 394 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 395 {
 396         struct vsock_sock *vlistener;
 397         struct vsock_sock *vconnected;
 398
 399         vlistener = vsock_sk(listener);
 400         vconnected = vsock_sk(connected);
 401
 402         sock_hold(connected);
 403         sock_hold(listener);
 404         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 405 }
 406 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 407
 408 static struct sock *vsock_dequeue_accept(struct sock *listener)
 409 {
 410         struct vsock_sock *vlistener;
 411         struct vsock_sock *vconnected;
 412
 413         vlistener = vsock_sk(listener);
 414
 415         if (list_empty(&vlistener->accept_queue))
 416                 return NULL;
 417
 418         vconnected = list_entry(vlistener->accept_queue.next,
 419                                 struct vsock_sock, accept_queue);
 420
 421         list_del_init(&vconnected->accept_queue);
 422         sock_put(listener);
 423         /* The caller will need a reference on the connected socket so we let
 424          * it call sock_put().
 425          */
 426
 427         return sk_vsock(vconnected);
 428 }
 429
 430 static bool vsock_is_accept_queue_empty(struct sock *sk)
 431 {
 432         struct vsock_sock *vsk = vsock_sk(sk);
 433         return list_empty(&vsk->accept_queue);
 434 }
 435
 436 static bool vsock_is_pending(struct sock *sk)
 437 {
 438         struct vsock_sock *vsk = vsock_sk(sk);
 439         return !list_empty(&vsk->pending_links);
 440 }
 441
 442 static int vsock_send_shutdown(struct sock *sk, int mode)
 443 {
 444         return transport->shutdown(vsock_sk(sk), mode);
 445 }
 446
 447 static void vsock_pending_work(struct work_struct *work)
 448 {
 449         struct sock *sk;
 450         struct sock *listener;
 451         struct vsock_sock *vsk;
 452         bool cleanup;
 453
 454         vsk = container_of(work, struct vsock_sock, pending_work.work);
 455         sk = sk_vsock(vsk);
 456         listener = vsk->listener;
 457         cleanup = true;
 458
 459         lock_sock(listener);
 460         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 461
 462         if (vsock_is_pending(sk)) {
 463                 vsock_remove_pending(listener, sk);
 464
 465                 listener->sk_ack_backlog--;
 466         } else if (!vsk->rejected) {
 467                 /* We are not on the pending list and accept() did not reject
 468                  * us, so we must have been accepted by our user process.  We
 469                  * just need to drop our references to the sockets and be on
 470                  * our way.
 471                  */
 472                 cleanup = false;
 473                 goto out;
 474         }
 475
 476         /* We need to remove ourself from the global connected sockets list so
 477          * incoming packets can't find this socket, and to reduce the reference
 478          * count.
 479          */
 480         if (vsock_in_connected_table(vsk))
 481                 vsock_remove_connected(vsk);
 482
 483         sk->sk_state = TCP_CLOSE;
 484
 485 out:
 486         release_sock(sk);
 487         release_sock(listener);
 488         if (cleanup)
 489                 sock_put(sk);
 490
 491         sock_put(sk);
 492         sock_put(listener);
 493 }
 494
 495 /**** SOCKET OPERATIONS ****/
 496
 497 static int __vsock_bind_stream(struct vsock_sock *vsk,
 498                                struct sockaddr_vm *addr)
 499 {
 500         static u32 port;
 501         struct sockaddr_vm new_addr;
 502
 503         if (!port)
 504                 port = LAST_RESERVED_PORT + 1 +
 505                         prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
 506
 507         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 508
 509         if (addr->svm_port == VMADDR_PORT_ANY) {
 510                 bool found = false;
 511                 unsigned int i;
 512
 513                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
 514                         if (port <= LAST_RESERVED_PORT)
 515                                 port = LAST_RESERVED_PORT + 1;
 516
 517                         new_addr.svm_port = port++;
 518
 519                         if (!__vsock_find_bound_socket(&new_addr)) {
 520                                 found = true;
 521                                 break;
 522                         }
 523                 }
 524
 525                 if (!found)
 526                         return -EADDRNOTAVAIL;
 527         } else {
 528                 /* If port is in reserved range, ensure caller
 529                  * has necessary privileges.
 530                  */
 531                 if (addr->svm_port <= LAST_RESERVED_PORT &&
 532                     !capable(CAP_NET_BIND_SERVICE)) {
 533                         return -EACCES;
 534                 }
 535
 536                 if (__vsock_find_bound_socket(&new_addr))
 537                         return -EADDRINUSE;
 538         }
 539
 540         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
 541
 542         /* Remove stream sockets from the unbound list and add them to the hash
 543          * table for easy lookup by its address.  The unbound list is simply an
 544          * extra entry at the end of the hash table, a trick used by AF_UNIX.
 545          */
 546         __vsock_remove_bound(vsk);
 547         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
 548
 549         return 0;
 550 }
 551
 552 static int __vsock_bind_dgram(struct vsock_sock *vsk,
 553                               struct sockaddr_vm *addr)
 554 {
 555         return transport->dgram_bind(vsk, addr);
 556 }
 557
 558 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 559 {
 560         struct vsock_sock *vsk = vsock_sk(sk);
 561         u32 cid;
 562         int retval;
 563
 564         /* First ensure this socket isn't already bound. */
 565         if (vsock_addr_bound(&vsk->local_addr))
 566                 return -EINVAL;
 567
 568         /* Now bind to the provided address or select appropriate values if
 569          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
 570          * like AF_INET prevents binding to a non-local IP address (in most
 571          * cases), we only allow binding to the local CID.
 572          */
 573         cid = transport->get_local_cid();
 574         if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)
 575                 return -EADDRNOTAVAIL;
 576
 577         switch (sk->sk_socket->type) {
 578         case SOCK_STREAM:
 579                 spin_lock_bh(&vsock_table_lock);
 580                 retval = __vsock_bind_stream(vsk, addr);
 581                 spin_unlock_bh(&vsock_table_lock);
 582                 break;
 583
 584         case SOCK_DGRAM:
 585                 retval = __vsock_bind_dgram(vsk, addr);
 586                 break;
 587
 588         default:
 589                 retval = -EINVAL;
 590                 break;
 591         }
 592
 593         return retval;
 594 }
 595
 596 static void vsock_connect_timeout(struct work_struct *work);
 597
 598 struct sock *__vsock_create(struct net *net,
 599                             struct socket *sock,
 600                             struct sock *parent,
 601                             gfp_t priority,
 602                             unsigned short type,
 603                             int kern)
 604 {
 605         struct sock *sk;
 606         struct vsock_sock *psk;
 607         struct vsock_sock *vsk;
 608
 609         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 610         if (!sk)
 611                 return NULL;
 612
 613         sock_init_data(sock, sk);
 614
 615         /* sk->sk_type is normally set in sock_init_data, but only if sock is
 616          * non-NULL. We make sure that our sockets always have a type by
 617          * setting it here if needed.
 618          */
 619         if (!sock)
 620                 sk->sk_type = type;
 621
 622         vsk = vsock_sk(sk);
 623         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 624         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 625
 626         sk->sk_destruct = vsock_sk_destruct;
 627         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 628         sock_reset_flag(sk, SOCK_DONE);
 629
 630         INIT_LIST_HEAD(&vsk->bound_table);
 631         INIT_LIST_HEAD(&vsk->connected_table);
 632         vsk->listener = NULL;
 633         INIT_LIST_HEAD(&vsk->pending_links);
 634         INIT_LIST_HEAD(&vsk->accept_queue);
 635         vsk->rejected = false;
 636         vsk->sent_request = false;
 637         vsk->ignore_connecting_rst = false;
 638         vsk->peer_shutdown = 0;
 639         INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 640         INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 641
 642         psk = parent ? vsock_sk(parent) : NULL;
 643         if (parent) {
 644                 vsk->trusted = psk->trusted;
 645                 vsk->owner = get_cred(psk->owner);
 646                 vsk->connect_timeout = psk->connect_timeout;
 647         } else {
 648                 vsk->trusted = capable(CAP_NET_ADMIN);
 649                 vsk->owner = get_current_cred();
 650                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 651         }
 652
 653         if (transport->init(vsk, psk) < 0) {
 654                 sk_free(sk);
 655                 return NULL;
 656         }
 657
 658         if (sock)
 659                 vsock_insert_unbound(vsk);
 660
 661         return sk;
 662 }
 663 EXPORT_SYMBOL_GPL(__vsock_create);
 664
 665 static void __vsock_release(struct sock *sk)
 666 {
 667         if (sk) {
 668                 struct sk_buff *skb;
 669                 struct sock *pending;
 670                 struct vsock_sock *vsk;
 671
 672                 vsk = vsock_sk(sk);
 673                 pending = NULL; /* Compiler warning. */
 674
 675                 transport->release(vsk);
 676
 677                 lock_sock(sk);
 678                 sock_orphan(sk);
 679                 sk->sk_shutdown = SHUTDOWN_MASK;
 680
 681                 while ((skb = skb_dequeue(&sk->sk_receive_queue)))
 682                         kfree_skb(skb);
 683
 684                 /* Clean up any sockets that never were accepted. */
 685                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 686                         __vsock_release(pending);
 687                         sock_put(pending);
 688                 }
 689
 690                 release_sock(sk);
 691                 sock_put(sk);
 692         }
 693 }
 694
 695 static void vsock_sk_destruct(struct sock *sk)
 696 {
 697         struct vsock_sock *vsk = vsock_sk(sk);
 698
 699         transport->destruct(vsk);
 700
 701         /* When clearing these addresses, there's no need to set the family and
 702          * possibly register the address family with the kernel.
 703          */
 704         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 705         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 706
 707         put_cred(vsk->owner);
 708 }
 709
 710 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 711 {
 712         int err;
 713
 714         err = sock_queue_rcv_skb(sk, skb);
 715         if (err)
 716                 kfree_skb(skb);
 717
 718         return err;
 719 }
 720
 721 s64 vsock_stream_has_data(struct vsock_sock *vsk)
 722 {
 723         return transport->stream_has_data(vsk);
 724 }
 725 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 726
 727 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 728 {
 729         return transport->stream_has_space(vsk);
 730 }
 731 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 732
 733 static int vsock_release(struct socket *sock)
 734 {
 735         __vsock_release(sock->sk);
 736         sock->sk = NULL;
 737         sock->state = SS_FREE;
 738
 739         return 0;
 740 }
 741
 742 static int
 743 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 744 {
 745         int err;
 746         struct sock *sk;
 747         struct sockaddr_vm *vm_addr;
 748
 749         sk = sock->sk;
 750
 751         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 752                 return -EINVAL;
 753
 754         lock_sock(sk);
 755         err = __vsock_bind(sk, vm_addr);
 756         release_sock(sk);
 757
 758         return err;
 759 }
 760
 761 static int vsock_getname(struct socket *sock,
 762                          struct sockaddr *addr, int peer)
 763 {
 764         int err;
 765         struct sock *sk;
 766         struct vsock_sock *vsk;
 767         struct sockaddr_vm *vm_addr;
 768
 769         sk = sock->sk;
 770         vsk = vsock_sk(sk);
 771         err = 0;
 772
 773         lock_sock(sk);
 774
 775         if (peer) {
 776                 if (sock->state != SS_CONNECTED) {
 777                         err = -ENOTCONN;
 778                         goto out;
 779                 }
 780                 vm_addr = &vsk->remote_addr;
 781         } else {
 782                 vm_addr = &vsk->local_addr;
 783         }
 784
 785         if (!vm_addr) {
 786                 err = -EINVAL;
 787                 goto out;
 788         }
 789
 790         /* sys_getsockname() and sys_getpeername() pass us a
 791          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 792          * that macro is defined in socket.c instead of .h, so we hardcode its
 793          * value here.
 794          */
 795         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 796         memcpy(addr, vm_addr, sizeof(*vm_addr));
 797         err = sizeof(*vm_addr);
 798
 799 out:
 800         release_sock(sk);
 801         return err;
 802 }
 803
 804 static int vsock_shutdown(struct socket *sock, int mode)
 805 {
 806         int err;
 807         struct sock *sk;
 808
 809         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 810          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 811          * here like the other address families do.  Note also that the
 812          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 813          * which is what we want.
 814          */
 815         mode++;
 816
 817         if ((mode & ~SHUTDOWN_MASK) || !mode)
 818                 return -EINVAL;
 819
 820         /* If this is a STREAM socket and it is not connected then bail out
 821          * immediately.  If it is a DGRAM socket then we must first kick the
 822          * socket so that it wakes up from any sleeping calls, for example
 823          * recv(), and then afterwards return the error.
 824          */
 825
 826         sk = sock->sk;
 827         if (sock->state == SS_UNCONNECTED) {
 828                 err = -ENOTCONN;
 829                 if (sk->sk_type == SOCK_STREAM)
 830                         return err;
 831         } else {
 832                 sock->state = SS_DISCONNECTING;
 833                 err = 0;
 834         }
 835
 836         /* Receive and send shutdowns are treated alike. */
 837         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
 838         if (mode) {
 839                 lock_sock(sk);
 840                 sk->sk_shutdown |= mode;
 841                 sk->sk_state_change(sk);
 842                 release_sock(sk);
 843
 844                 if (sk->sk_type == SOCK_STREAM) {
 845                         sock_reset_flag(sk, SOCK_DONE);
 846                         vsock_send_shutdown(sk, mode);
 847                 }
 848         }
 849
 850         return err;
 851 }
 852
 853 static __poll_t vsock_poll(struct file *file, struct socket *sock,
 854                                poll_table *wait)
 855 {
 856         struct sock *sk;
 857         __poll_t mask;
 858         struct vsock_sock *vsk;
 859
 860         sk = sock->sk;
 861         vsk = vsock_sk(sk);
 862
 863         poll_wait(file, sk_sleep(sk), wait);
 864         mask = 0;
 865
 866         if (sk->sk_err)
 867                 /* Signify that there has been an error on this socket. */
 868                 mask |= EPOLLERR;
 869
 870         /* INET sockets treat local write shutdown and peer write shutdown as a
 871          * case of EPOLLHUP set.
 872          */
 873         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
 874             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
 875              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
 876                 mask |= EPOLLHUP;
 877         }
 878
 879         if (sk->sk_shutdown & RCV_SHUTDOWN ||
 880             vsk->peer_shutdown & SEND_SHUTDOWN) {
 881                 mask |= EPOLLRDHUP;
 882         }
 883
 884         if (sock->type == SOCK_DGRAM) {
 885                 /* For datagram sockets we can read if there is something in
 886                  * the queue and write as long as the socket isn't shutdown for
 887                  * sending.
 888                  */
 889                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
 890                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
 891                         mask |= EPOLLIN | EPOLLRDNORM;
 892                 }
 893
 894                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
 895                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
 896
 897         } else if (sock->type == SOCK_STREAM) {
 898                 lock_sock(sk);
 899
 900                 /* Listening sockets that have connections in their accept
 901                  * queue can be read.
 902                  */
 903                 if (sk->sk_state == TCP_LISTEN
 904                     && !vsock_is_accept_queue_empty(sk))
 905                         mask |= EPOLLIN | EPOLLRDNORM;
 906
 907                 /* If there is something in the queue then we can read. */
 908                 if (transport->stream_is_active(vsk) &&
 909                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
 910                         bool data_ready_now = false;
 911                         int ret = transport->notify_poll_in(
 912                                         vsk, 1, &data_ready_now);
 913                         if (ret < 0) {
 914                                 mask |= EPOLLERR;
 915                         } else {
 916                                 if (data_ready_now)
 917                                         mask |= EPOLLIN | EPOLLRDNORM;
 918
 919                         }
 920                 }
 921
 922                 /* Sockets whose connections have been closed, reset, or
 923                  * terminated should also be considered read, and we check the
 924                  * shutdown flag for that.
 925                  */
 926                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
 927                     vsk->peer_shutdown & SEND_SHUTDOWN) {
 928                         mask |= EPOLLIN | EPOLLRDNORM;
 929                 }
 930
 931                 /* Connected sockets that can produce data can be written. */
 932                 if (sk->sk_state == TCP_ESTABLISHED) {
 933                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 934                                 bool space_avail_now = false;
 935                                 int ret = transport->notify_poll_out(
 936                                                 vsk, 1, &space_avail_now);
 937                                 if (ret < 0) {
 938                                         mask |= EPOLLERR;
 939                                 } else {
 940                                         if (space_avail_now)
 941                                                 /* Remove EPOLLWRBAND since INET
 942                                                  * sockets are not setting it.
 943                                                  */
 944                                                 mask |= EPOLLOUT | EPOLLWRNORM;
 945
 946                                 }
 947                         }
 948                 }
 949
 950                 /* Simulate INET socket poll behaviors, which sets
 951                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
 952                  * but local send is not shutdown.
 953                  */
 954                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
 955                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
 956                                 mask |= EPOLLOUT | EPOLLWRNORM;
 957
 958                 }
 959
 960                 release_sock(sk);
 961         }
 962
 963         return mask;
 964 }
 965
 966 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 967                                size_t len)
 968 {
 969         int err;
 970         struct sock *sk;
 971         struct vsock_sock *vsk;
 972         struct sockaddr_vm *remote_addr;
 973
 974         if (msg->msg_flags & MSG_OOB)
 975                 return -EOPNOTSUPP;
 976
 977         /* For now, MSG_DONTWAIT is always assumed... */
 978         err = 0;
 979         sk = sock->sk;
 980         vsk = vsock_sk(sk);
 981
 982         lock_sock(sk);
 983
 984         err = vsock_auto_bind(vsk);
 985         if (err)
 986                 goto out;
 987
 988
 989         /* If the provided message contains an address, use that.  Otherwise
 990          * fall back on the socket's remote handle (if it has been connected).
 991          */
 992         if (msg->msg_name &&
 993             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
 994                             &remote_addr) == 0) {
 995                 /* Ensure this address is of the right type and is a valid
 996                  * destination.
 997                  */
 998
 999                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1000                         remote_addr->svm_cid = transport->get_local_cid();
1001
1002                 if (!vsock_addr_bound(remote_addr)) {
1003                         err = -EINVAL;
1004                         goto out;
1005                 }
1006         } else if (sock->state == SS_CONNECTED) {
1007                 remote_addr = &vsk->remote_addr;
1008
1009                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1010                         remote_addr->svm_cid = transport->get_local_cid();
1011
1012                 /* XXX Should connect() or this function ensure remote_addr is
1013                  * bound?
1014                  */
1015                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1016                         err = -EINVAL;
1017                         goto out;
1018                 }
1019         } else {
1020                 err = -EINVAL;
1021                 goto out;
1022         }
1023
1024         if (!transport->dgram_allow(remote_addr->svm_cid,
1025                                     remote_addr->svm_port)) {
1026                 err = -EINVAL;
1027                 goto out;
1028         }
1029
1030         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1031
1032 out:
1033         release_sock(sk);
1034         return err;
1035 }
1036
1037 static int vsock_dgram_connect(struct socket *sock,
1038                                struct sockaddr *addr, int addr_len, int flags)
1039 {
1040         int err;
1041         struct sock *sk;
1042         struct vsock_sock *vsk;
1043         struct sockaddr_vm *remote_addr;
1044
1045         sk = sock->sk;
1046         vsk = vsock_sk(sk);
1047
1048         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1049         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1050                 lock_sock(sk);
1051                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1052                                 VMADDR_PORT_ANY);
1053                 sock->state = SS_UNCONNECTED;
1054                 release_sock(sk);
1055                 return 0;
1056         } else if (err != 0)
1057                 return -EINVAL;
1058
1059         lock_sock(sk);
1060
1061         err = vsock_auto_bind(vsk);
1062         if (err)
1063                 goto out;
1064
1065         if (!transport->dgram_allow(remote_addr->svm_cid,
1066                                     remote_addr->svm_port)) {
1067                 err = -EINVAL;
1068                 goto out;
1069         }
1070
1071         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1072         sock->state = SS_CONNECTED;
1073
1074 out:
1075         release_sock(sk);
1076         return err;
1077 }
1078
1079 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1080                                size_t len, int flags)
1081 {
1082         return transport->dgram_dequeue(vsock_sk(sock->sk), msg, len, flags);
1083 }
1084
1085 static const struct proto_ops vsock_dgram_ops = {
1086         .family = PF_VSOCK,
1087         .owner = THIS_MODULE,
1088         .release = vsock_release,
1089         .bind = vsock_bind,
1090         .connect = vsock_dgram_connect,
1091         .socketpair = sock_no_socketpair,
1092         .accept = sock_no_accept,
1093         .getname = vsock_getname,
1094         .poll = vsock_poll,
1095         .ioctl = sock_no_ioctl,
1096         .listen = sock_no_listen,
1097         .shutdown = vsock_shutdown,
1098         .setsockopt = sock_no_setsockopt,
1099         .getsockopt = sock_no_getsockopt,
1100         .sendmsg = vsock_dgram_sendmsg,
1101         .recvmsg = vsock_dgram_recvmsg,
1102         .mmap = sock_no_mmap,
1103         .sendpage = sock_no_sendpage,
1104 };
1105
1106 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1107 {
1108         if (!transport->cancel_pkt)
1109                 return -EOPNOTSUPP;
1110
1111         return transport->cancel_pkt(vsk);
1112 }
1113
1114 static void vsock_connect_timeout(struct work_struct *work)
1115 {
1116         struct sock *sk;
1117         struct vsock_sock *vsk;
1118         int cancel = 0;
1119
1120         vsk = container_of(work, struct vsock_sock, connect_work.work);
1121         sk = sk_vsock(vsk);
1122
1123         lock_sock(sk);
1124         if (sk->sk_state == TCP_SYN_SENT &&
1125             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1126                 sk->sk_state = TCP_CLOSE;
1127                 sk->sk_err = ETIMEDOUT;
1128                 sk->sk_error_report(sk);
1129                 cancel = 1;
1130         }
1131         release_sock(sk);
1132         if (cancel)
1133                 vsock_transport_cancel_pkt(vsk);
1134
1135         sock_put(sk);
1136 }
1137
1138 static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
1139                                 int addr_len, int flags)
1140 {
1141         int err;
1142         struct sock *sk;
1143         struct vsock_sock *vsk;
1144         struct sockaddr_vm *remote_addr;
1145         long timeout;
1146         DEFINE_WAIT(wait);
1147
1148         err = 0;
1149         sk = sock->sk;
1150         vsk = vsock_sk(sk);
1151
1152         lock_sock(sk);
1153
1154         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1155         switch (sock->state) {
1156         case SS_CONNECTED:
1157                 err = -EISCONN;
1158                 goto out;
1159         case SS_DISCONNECTING:
1160                 err = -EINVAL;
1161                 goto out;
1162         case SS_CONNECTING:
1163                 /* This continues on so we can move sock into the SS_CONNECTED
1164                  * state once the connection has completed (at which point err
1165                  * will be set to zero also).  Otherwise, we will either wait
1166                  * for the connection or return -EALREADY should this be a
1167                  * non-blocking call.
1168                  */
1169                 err = -EALREADY;
1170                 break;
1171         default:
1172                 if ((sk->sk_state == TCP_LISTEN) ||
1173                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1174                         err = -EINVAL;
1175                         goto out;
1176                 }
1177
1178                 /* The hypervisor and well-known contexts do not have socket
1179                  * endpoints.
1180                  */
1181                 if (!transport->stream_allow(remote_addr->svm_cid,
1182                                              remote_addr->svm_port)) {
1183                         err = -ENETUNREACH;
1184                         goto out;
1185                 }
1186
1187                 /* Set the remote address that we are connecting to. */
1188                 memcpy(&vsk->remote_addr, remote_addr,
1189                        sizeof(vsk->remote_addr));
1190
1191                 err = vsock_auto_bind(vsk);
1192                 if (err)
1193                         goto out;
1194
1195                 sk->sk_state = TCP_SYN_SENT;
1196
1197                 err = transport->connect(vsk);
1198                 if (err < 0)
1199                         goto out;
1200
1201                 /* Mark sock as connecting and set the error code to in
1202                  * progress in case this is a non-blocking connect.
1203                  */
1204                 sock->state = SS_CONNECTING;
1205                 err = -EINPROGRESS;
1206         }
1207
1208         /* The receive path will handle all communication until we are able to
1209          * enter the connected state.  Here we wait for the connection to be
1210          * completed or a notification of an error.
1211          */
1212         timeout = vsk->connect_timeout;
1213         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1214
1215         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1216                 if (flags & O_NONBLOCK) {
1217                         /* If we're not going to block, we schedule a timeout
1218                          * function to generate a timeout on the connection
1219                          * attempt, in case the peer doesn't respond in a
1220                          * timely manner. We hold on to the socket until the
1221                          * timeout fires.
1222                          */
1223                         sock_hold(sk);
1224                         schedule_delayed_work(&vsk->connect_work, timeout);
1225
1226                         /* Skip ahead to preserve error code set above. */
1227                         goto out_wait;
1228                 }
1229
1230                 release_sock(sk);
1231                 timeout = schedule_timeout(timeout);
1232                 lock_sock(sk);
1233
1234                 if (signal_pending(current)) {
1235                         err = sock_intr_errno(timeout);
1236                         sk->sk_state = TCP_CLOSE;
1237                         sock->state = SS_UNCONNECTED;
1238                         vsock_transport_cancel_pkt(vsk);
1239                         goto out_wait;
1240                 } else if (timeout == 0) {
1241                         err = -ETIMEDOUT;
1242                         sk->sk_state = TCP_CLOSE;
1243                         sock->state = SS_UNCONNECTED;
1244                         vsock_transport_cancel_pkt(vsk);
1245                         goto out_wait;
1246                 }
1247
1248                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1249         }
1250
1251         if (sk->sk_err) {
1252                 err = -sk->sk_err;
1253                 sk->sk_state = TCP_CLOSE;
1254                 sock->state = SS_UNCONNECTED;
1255         } else {
1256                 err = 0;
1257         }
1258
1259 out_wait:
1260         finish_wait(sk_sleep(sk), &wait);
1261 out:
1262         release_sock(sk);
1263         return err;
1264 }
1265
1266 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1267                         bool kern)
1268 {
1269         struct sock *listener;
1270         int err;
1271         struct sock *connected;
1272         struct vsock_sock *vconnected;
1273         long timeout;
1274         DEFINE_WAIT(wait);
1275
1276         err = 0;
1277         listener = sock->sk;
1278
1279         lock_sock(listener);
1280
1281         if (sock->type != SOCK_STREAM) {
1282                 err = -EOPNOTSUPP;
1283                 goto out;
1284         }
1285
1286         if (listener->sk_state != TCP_LISTEN) {
1287                 err = -EINVAL;
1288                 goto out;
1289         }
1290
1291         /* Wait for children sockets to appear; these are the new sockets
1292          * created upon connection establishment.
1293          */
1294         timeout = sock_sndtimeo(listener, flags & O_NONBLOCK);
1295         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1296
1297         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1298                listener->sk_err == 0) {
1299                 release_sock(listener);
1300                 timeout = schedule_timeout(timeout);
1301                 finish_wait(sk_sleep(listener), &wait);
1302                 lock_sock(listener);
1303
1304                 if (signal_pending(current)) {
1305                         err = sock_intr_errno(timeout);
1306                         goto out;
1307                 } else if (timeout == 0) {
1308                         err = -EAGAIN;
1309                         goto out;
1310                 }
1311
1312                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1313         }
1314         finish_wait(sk_sleep(listener), &wait);
1315
1316         if (listener->sk_err)
1317                 err = -listener->sk_err;
1318
1319         if (connected) {
1320                 listener->sk_ack_backlog--;
1321
1322                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1323                 vconnected = vsock_sk(connected);
1324
1325                 /* If the listener socket has received an error, then we should
1326                  * reject this socket and return.  Note that we simply mark the
1327                  * socket rejected, drop our reference, and let the cleanup
1328                  * function handle the cleanup; the fact that we found it in
1329                  * the listener's accept queue guarantees that the cleanup
1330                  * function hasn't run yet.
1331                  */
1332                 if (err) {
1333                         vconnected->rejected = true;
1334                 } else {
1335                         newsock->state = SS_CONNECTED;
1336                         sock_graft(connected, newsock);
1337                 }
1338
1339                 release_sock(connected);
1340                 sock_put(connected);
1341         }
1342
1343 out:
1344         release_sock(listener);
1345         return err;
1346 }
1347
1348 static int vsock_listen(struct socket *sock, int backlog)
1349 {
1350         int err;
1351         struct sock *sk;
1352         struct vsock_sock *vsk;
1353
1354         sk = sock->sk;
1355
1356         lock_sock(sk);
1357
1358         if (sock->type != SOCK_STREAM) {
1359                 err = -EOPNOTSUPP;
1360                 goto out;
1361         }
1362
1363         if (sock->state != SS_UNCONNECTED) {
1364                 err = -EINVAL;
1365                 goto out;
1366         }
1367
1368         vsk = vsock_sk(sk);
1369
1370         if (!vsock_addr_bound(&vsk->local_addr)) {
1371                 err = -EINVAL;
1372                 goto out;
1373         }
1374
1375         sk->sk_max_ack_backlog = backlog;
1376         sk->sk_state = TCP_LISTEN;
1377
1378         err = 0;
1379
1380 out:
1381         release_sock(sk);
1382         return err;
1383 }
1384
1385 static int vsock_stream_setsockopt(struct socket *sock,
1386                                    int level,
1387                                    int optname,
1388                                    char __user *optval,
1389                                    unsigned int optlen)
1390 {
1391         int err;
1392         struct sock *sk;
1393         struct vsock_sock *vsk;
1394         u64 val;
1395
1396         if (level != AF_VSOCK)
1397                 return -ENOPROTOOPT;
1398
1399 #define COPY_IN(_v)                                       \
1400         do {                                              \
1401                 if (optlen < sizeof(_v)) {                \
1402                         err = -EINVAL;                    \
1403                         goto exit;                        \
1404                 }                                         \
1405                 if (copy_from_user(&_v, optval, sizeof(_v)) != 0) {     \
1406                         err = -EFAULT;                                  \
1407                         goto exit;                                      \
1408                 }                                                       \
1409         } while (0)
1410
1411         err = 0;
1412         sk = sock->sk;
1413         vsk = vsock_sk(sk);
1414
1415         lock_sock(sk);
1416
1417         switch (optname) {
1418         case SO_VM_SOCKETS_BUFFER_SIZE:
1419                 COPY_IN(val);
1420                 transport->set_buffer_size(vsk, val);
1421                 break;
1422
1423         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1424                 COPY_IN(val);
1425                 transport->set_max_buffer_size(vsk, val);
1426                 break;
1427
1428         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1429                 COPY_IN(val);
1430                 transport->set_min_buffer_size(vsk, val);
1431                 break;
1432
1433         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1434                 struct __kernel_old_timeval tv;
1435                 COPY_IN(tv);
1436                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1437                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1438                         vsk->connect_timeout = tv.tv_sec * HZ +
1439                             DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1440                         if (vsk->connect_timeout == 0)
1441                                 vsk->connect_timeout =
1442                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1443
1444                 } else {
1445                         err = -ERANGE;
1446                 }
1447                 break;
1448         }
1449
1450         default:
1451                 err = -ENOPROTOOPT;
1452                 break;
1453         }
1454
1455 #undef COPY_IN
1456
1457 exit:
1458         release_sock(sk);
1459         return err;
1460 }
1461
1462 static int vsock_stream_getsockopt(struct socket *sock,
1463                                    int level, int optname,
1464                                    char __user *optval,
1465                                    int __user *optlen)
1466 {
1467         int err;
1468         int len;
1469         struct sock *sk;
1470         struct vsock_sock *vsk;
1471         u64 val;
1472
1473         if (level != AF_VSOCK)
1474                 return -ENOPROTOOPT;
1475
1476         err = get_user(len, optlen);
1477         if (err != 0)
1478                 return err;
1479
1480 #define COPY_OUT(_v)                            \
1481         do {                                    \
1482                 if (len < sizeof(_v))           \
1483                         return -EINVAL;         \
1484                                                 \
1485                 len = sizeof(_v);               \
1486                 if (copy_to_user(optval, &_v, len) != 0)        \
1487                         return -EFAULT;                         \
1488                                                                 \
1489         } while (0)
1490
1491         err = 0;
1492         sk = sock->sk;
1493         vsk = vsock_sk(sk);
1494
1495         switch (optname) {
1496         case SO_VM_SOCKETS_BUFFER_SIZE:
1497                 val = transport->get_buffer_size(vsk);
1498                 COPY_OUT(val);
1499                 break;
1500
1501         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1502                 val = transport->get_max_buffer_size(vsk);
1503                 COPY_OUT(val);
1504                 break;
1505
1506         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1507                 val = transport->get_min_buffer_size(vsk);
1508                 COPY_OUT(val);
1509                 break;
1510
1511         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1512                 struct __kernel_old_timeval tv;
1513                 tv.tv_sec = vsk->connect_timeout / HZ;
1514                 tv.tv_usec =
1515                     (vsk->connect_timeout -
1516                      tv.tv_sec * HZ) * (1000000 / HZ);
1517                 COPY_OUT(tv);
1518                 break;
1519         }
1520         default:
1521                 return -ENOPROTOOPT;
1522         }
1523
1524         err = put_user(len, optlen);
1525         if (err != 0)
1526                 return -EFAULT;
1527
1528 #undef COPY_OUT
1529
1530         return 0;
1531 }
1532
1533 static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1534                                 size_t len)
1535 {
1536         struct sock *sk;
1537         struct vsock_sock *vsk;
1538         ssize_t total_written;
1539         long timeout;
1540         int err;
1541         struct vsock_transport_send_notify_data send_data;
1542         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1543
1544         sk = sock->sk;
1545         vsk = vsock_sk(sk);
1546         total_written = 0;
1547         err = 0;
1548
1549         if (msg->msg_flags & MSG_OOB)
1550                 return -EOPNOTSUPP;
1551
1552         lock_sock(sk);
1553
1554         /* Callers should not provide a destination with stream sockets. */
1555         if (msg->msg_namelen) {
1556                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1557                 goto out;
1558         }
1559
1560         /* Send data only if both sides are not shutdown in the direction. */
1561         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1562             vsk->peer_shutdown & RCV_SHUTDOWN) {
1563                 err = -EPIPE;
1564                 goto out;
1565         }
1566
1567         if (sk->sk_state != TCP_ESTABLISHED ||
1568             !vsock_addr_bound(&vsk->local_addr)) {
1569                 err = -ENOTCONN;
1570                 goto out;
1571         }
1572
1573         if (!vsock_addr_bound(&vsk->remote_addr)) {
1574                 err = -EDESTADDRREQ;
1575                 goto out;
1576         }
1577
1578         /* Wait for room in the produce queue to enqueue our user's data. */
1579         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1580
1581         err = transport->notify_send_init(vsk, &send_data);
1582         if (err < 0)
1583                 goto out;
1584
1585         while (total_written < len) {
1586                 ssize_t written;
1587
1588                 add_wait_queue(sk_sleep(sk), &wait);
1589                 while (vsock_stream_has_space(vsk) == 0 &&
1590                        sk->sk_err == 0 &&
1591                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1592                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1593
1594                         /* Don't wait for non-blocking sockets. */
1595                         if (timeout == 0) {
1596                                 err = -EAGAIN;
1597                                 remove_wait_queue(sk_sleep(sk), &wait);
1598                                 goto out_err;
1599                         }
1600
1601                         err = transport->notify_send_pre_block(vsk, &send_data);
1602                         if (err < 0) {
1603                                 remove_wait_queue(sk_sleep(sk), &wait);
1604                                 goto out_err;
1605                         }
1606
1607                         release_sock(sk);
1608                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1609                         lock_sock(sk);
1610                         if (signal_pending(current)) {
1611                                 err = sock_intr_errno(timeout);
1612                                 remove_wait_queue(sk_sleep(sk), &wait);
1613                                 goto out_err;
1614                         } else if (timeout == 0) {
1615                                 err = -EAGAIN;
1616                                 remove_wait_queue(sk_sleep(sk), &wait);
1617                                 goto out_err;
1618                         }
1619                 }
1620                 remove_wait_queue(sk_sleep(sk), &wait);
1621
1622                 /* These checks occur both as part of and after the loop
1623                  * conditional since we need to check before and after
1624                  * sleeping.
1625                  */
1626                 if (sk->sk_err) {
1627                         err = -sk->sk_err;
1628                         goto out_err;
1629                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1630                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1631                         err = -EPIPE;
1632                         goto out_err;
1633                 }
1634
1635                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1636                 if (err < 0)
1637                         goto out_err;
1638
1639                 /* Note that enqueue will only write as many bytes as are free
1640                  * in the produce queue, so we don't need to ensure len is
1641                  * smaller than the queue size.  It is the caller's
1642                  * responsibility to check how many bytes we were able to send.
1643                  */
1644
1645                 written = transport->stream_enqueue(
1646                                 vsk, msg,
1647                                 len - total_written);
1648                 if (written < 0) {
1649                         err = -ENOMEM;
1650                         goto out_err;
1651                 }
1652
1653                 total_written += written;
1654
1655                 err = transport->notify_send_post_enqueue(
1656                                 vsk, written, &send_data);
1657                 if (err < 0)
1658                         goto out_err;
1659
1660         }
1661
1662 out_err:
1663         if (total_written > 0)
1664                 err = total_written;
1665 out:
1666         release_sock(sk);
1667         return err;
1668 }
1669
1670
1671 static int
1672 vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1673                      int flags)
1674 {
1675         struct sock *sk;
1676         struct vsock_sock *vsk;
1677         int err;
1678         size_t target;
1679         ssize_t copied;
1680         long timeout;
1681         struct vsock_transport_recv_notify_data recv_data;
1682
1683         DEFINE_WAIT(wait);
1684
1685         sk = sock->sk;
1686         vsk = vsock_sk(sk);
1687         err = 0;
1688
1689         lock_sock(sk);
1690
1691         if (sk->sk_state != TCP_ESTABLISHED) {
1692                 /* Recvmsg is supposed to return 0 if a peer performs an
1693                  * orderly shutdown. Differentiate between that case and when a
1694                  * peer has not connected or a local shutdown occured with the
1695                  * SOCK_DONE flag.
1696                  */
1697                 if (sock_flag(sk, SOCK_DONE))
1698                         err = 0;
1699                 else
1700                         err = -ENOTCONN;
1701
1702                 goto out;
1703         }
1704
1705         if (flags & MSG_OOB) {
1706                 err = -EOPNOTSUPP;
1707                 goto out;
1708         }
1709
1710         /* We don't check peer_shutdown flag here since peer may actually shut
1711          * down, but there can be data in the queue that a local socket can
1712          * receive.
1713          */
1714         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1715                 err = 0;
1716                 goto out;
1717         }
1718
1719         /* It is valid on Linux to pass in a zero-length receive buffer.  This
1720          * is not an error.  We may as well bail out now.
1721          */
1722         if (!len) {
1723                 err = 0;
1724                 goto out;
1725         }
1726
1727         /* We must not copy less than target bytes into the user's buffer
1728          * before returning successfully, so we wait for the consume queue to
1729          * have that much data to consume before dequeueing.  Note that this
1730          * makes it impossible to handle cases where target is greater than the
1731          * queue size.
1732          */
1733         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1734         if (target >= transport->stream_rcvhiwat(vsk)) {
1735                 err = -ENOMEM;
1736                 goto out;
1737         }
1738         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1739         copied = 0;
1740
1741         err = transport->notify_recv_init(vsk, target, &recv_data);
1742         if (err < 0)
1743                 goto out;
1744
1745
1746         while (1) {
1747                 s64 ready;
1748
1749                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1750                 ready = vsock_stream_has_data(vsk);
1751
1752                 if (ready == 0) {
1753                         if (sk->sk_err != 0 ||
1754                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
1755                             (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1756                                 finish_wait(sk_sleep(sk), &wait);
1757                                 break;
1758                         }
1759                         /* Don't wait for non-blocking sockets. */
1760                         if (timeout == 0) {
1761                                 err = -EAGAIN;
1762                                 finish_wait(sk_sleep(sk), &wait);
1763                                 break;
1764                         }
1765
1766                         err = transport->notify_recv_pre_block(
1767                                         vsk, target, &recv_data);
1768                         if (err < 0) {
1769                                 finish_wait(sk_sleep(sk), &wait);
1770                                 break;
1771                         }
1772                         release_sock(sk);
1773                         timeout = schedule_timeout(timeout);
1774                         lock_sock(sk);
1775
1776                         if (signal_pending(current)) {
1777                                 err = sock_intr_errno(timeout);
1778                                 finish_wait(sk_sleep(sk), &wait);
1779                                 break;
1780                         } else if (timeout == 0) {
1781                                 err = -EAGAIN;
1782                                 finish_wait(sk_sleep(sk), &wait);
1783                                 break;
1784                         }
1785                 } else {
1786                         ssize_t read;
1787
1788                         finish_wait(sk_sleep(sk), &wait);
1789
1790                         if (ready < 0) {
1791                                 /* Invalid queue pair content. XXX This should
1792                                 * be changed to a connection reset in a later
1793                                 * change.
1794                                 */
1795
1796                                 err = -ENOMEM;
1797                                 goto out;
1798                         }
1799
1800                         err = transport->notify_recv_pre_dequeue(
1801                                         vsk, target, &recv_data);
1802                         if (err < 0)
1803                                 break;
1804
1805                         read = transport->stream_dequeue(
1806                                         vsk, msg,
1807                                         len - copied, flags);
1808                         if (read < 0) {
1809                                 err = -ENOMEM;
1810                                 break;
1811                         }
1812
1813                         copied += read;
1814
1815                         err = transport->notify_recv_post_dequeue(
1816                                         vsk, target, read,
1817                                         !(flags & MSG_PEEK), &recv_data);
1818                         if (err < 0)
1819                                 goto out;
1820
1821                         if (read >= target || flags & MSG_PEEK)
1822                                 break;
1823
1824                         target -= read;
1825                 }
1826         }
1827
1828         if (sk->sk_err)
1829                 err = -sk->sk_err;
1830         else if (sk->sk_shutdown & RCV_SHUTDOWN)
1831                 err = 0;
1832
1833         if (copied > 0)
1834                 err = copied;
1835
1836 out:
1837         release_sock(sk);
1838         return err;
1839 }
1840
1841 static const struct proto_ops vsock_stream_ops = {
1842         .family = PF_VSOCK,
1843         .owner = THIS_MODULE,
1844         .release = vsock_release,
1845         .bind = vsock_bind,
1846         .connect = vsock_stream_connect,
1847         .socketpair = sock_no_socketpair,
1848         .accept = vsock_accept,
1849         .getname = vsock_getname,
1850         .poll = vsock_poll,
1851         .ioctl = sock_no_ioctl,
1852         .listen = vsock_listen,
1853         .shutdown = vsock_shutdown,
1854         .setsockopt = vsock_stream_setsockopt,
1855         .getsockopt = vsock_stream_getsockopt,
1856         .sendmsg = vsock_stream_sendmsg,
1857         .recvmsg = vsock_stream_recvmsg,
1858         .mmap = sock_no_mmap,
1859         .sendpage = sock_no_sendpage,
1860 };
1861
1862 static int vsock_create(struct net *net, struct socket *sock,
1863                         int protocol, int kern)
1864 {
1865         if (!sock)
1866                 return -EINVAL;
1867
1868         if (protocol && protocol != PF_VSOCK)
1869                 return -EPROTONOSUPPORT;
1870
1871         switch (sock->type) {
1872         case SOCK_DGRAM:
1873                 sock->ops = &vsock_dgram_ops;
1874                 break;
1875         case SOCK_STREAM:
1876                 sock->ops = &vsock_stream_ops;
1877                 break;
1878         default:
1879                 return -ESOCKTNOSUPPORT;
1880         }
1881
1882         sock->state = SS_UNCONNECTED;
1883
1884         return __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern) ? 0 : -ENOMEM;
1885 }
1886
1887 static const struct net_proto_family vsock_family_ops = {
1888         .family = AF_VSOCK,
1889         .create = vsock_create,
1890         .owner = THIS_MODULE,
1891 };
1892
1893 static long vsock_dev_do_ioctl(struct file *filp,
1894                                unsigned int cmd, void __user *ptr)
1895 {
1896         u32 __user *p = ptr;
1897         int retval = 0;
1898
1899         switch (cmd) {
1900         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
1901                 if (put_user(transport->get_local_cid(), p) != 0)
1902                         retval = -EFAULT;
1903                 break;
1904
1905         default:
1906                 pr_err("Unknown ioctl %d\n", cmd);
1907                 retval = -EINVAL;
1908         }
1909
1910         return retval;
1911 }
1912
1913 static long vsock_dev_ioctl(struct file *filp,
1914                             unsigned int cmd, unsigned long arg)
1915 {
1916         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
1917 }
1918
1919 #ifdef CONFIG_COMPAT
1920 static long vsock_dev_compat_ioctl(struct file *filp,
1921                                    unsigned int cmd, unsigned long arg)
1922 {
1923         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
1924 }
1925 #endif
1926
1927 static const struct file_operations vsock_device_ops = {
1928         .owner          = THIS_MODULE,
1929         .unlocked_ioctl = vsock_dev_ioctl,
1930 #ifdef CONFIG_COMPAT
1931         .compat_ioctl   = vsock_dev_compat_ioctl,
1932 #endif
1933         .open           = nonseekable_open,
1934 };
1935
1936 static struct miscdevice vsock_device = {
1937         .name           = "vsock",
1938         .fops           = &vsock_device_ops,
1939 };
1940
1941 int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
1942 {
1943         int err = mutex_lock_interruptible(&vsock_register_mutex);
1944
1945         if (err)
1946                 return err;
1947
1948         if (transport) {
1949                 err = -EBUSY;
1950                 goto err_busy;
1951         }
1952
1953         /* Transport must be the owner of the protocol so that it can't
1954          * unload while there are open sockets.
1955          */
1956         vsock_proto.owner = owner;
1957         transport = t;
1958
1959         vsock_device.minor = MISC_DYNAMIC_MINOR;
1960         err = misc_register(&vsock_device);
1961         if (err) {
1962                 pr_err("Failed to register misc device\n");
1963                 goto err_reset_transport;
1964         }
1965
1966         err = proto_register(&vsock_proto, 1);  /* we want our slab */
1967         if (err) {
1968                 pr_err("Cannot register vsock protocol\n");
1969                 goto err_deregister_misc;
1970         }
1971
1972         err = sock_register(&vsock_family_ops);
1973         if (err) {
1974                 pr_err("could not register af_vsock (%d) address family: %d\n",
1975                        AF_VSOCK, err);
1976                 goto err_unregister_proto;
1977         }
1978
1979         mutex_unlock(&vsock_register_mutex);
1980         return 0;
1981
1982 err_unregister_proto:
1983         proto_unregister(&vsock_proto);
1984 err_deregister_misc:
1985         misc_deregister(&vsock_device);
1986 err_reset_transport:
1987         transport = NULL;
1988 err_busy:
1989         mutex_unlock(&vsock_register_mutex);
1990         return err;
1991 }
1992 EXPORT_SYMBOL_GPL(__vsock_core_init);
1993
1994 void vsock_core_exit(void)
1995 {
1996         mutex_lock(&vsock_register_mutex);
1997
1998         misc_deregister(&vsock_device);
1999         sock_unregister(AF_VSOCK);
2000         proto_unregister(&vsock_proto);
2001
2002         /* We do not want the assignment below re-ordered. */
2003         mb();
2004         transport = NULL;
2005
2006         mutex_unlock(&vsock_register_mutex);
2007 }
2008 EXPORT_SYMBOL_GPL(vsock_core_exit);
2009
2010 const struct vsock_transport *vsock_core_get_transport(void)
2011 {
2012         /* vsock_register_mutex not taken since only the transport uses this
2013          * function and only while registered.
2014          */
2015         return transport;
2016 }
2017 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2018
2019 static void __exit vsock_exit(void)
2020 {
2021         /* Do nothing.  This function makes this module removable. */
2022 }
2023
2024 module_init(vsock_init_tables);
2025 module_exit(vsock_exit);
2026
2027 MODULE_AUTHOR("VMware, Inc.");
2028 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2029 MODULE_VERSION("1.0.2.0-k");
2030 MODULE_LICENSE("GPL v2");