net/vmw_vsock/af_vsock.c

   1 /*
   2  * VMware vSockets Driver
   3  *
   4  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation version 2 and no later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  */
  15
  16 /* Implementation notes:
  17  *
  18  * - There are two kinds of sockets: those created by user action (such as
  19  * calling socket(2)) and those created by incoming connection request packets.
  20  *
  21  * - There are two "global" tables, one for bound sockets (sockets that have
  22  * specified an address that they are responsible for) and one for connected
  23  * sockets (sockets that have established a connection with another socket).
  24  * These tables are "global" in that all sockets on the system are placed
  25  * within them. - Note, though, that the bound table contains an extra entry
  26  * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
  27  * that list. The bound table is used solely for lookup of sockets when packets
  28  * are received and that's not necessary for SOCK_DGRAM sockets since we create
  29  * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
  30  * sockets out of the bound hash buckets will reduce the chance of collisions
  31  * when looking for SOCK_STREAM sockets and prevents us from having to check the
  32  * socket type in the hash table lookups.
  33  *
  34  * - Sockets created by user action will either be "client" sockets that
  35  * initiate a connection or "server" sockets that listen for connections; we do
  36  * not support simultaneous connects (two "client" sockets connecting).
  37  *
  38  * - "Server" sockets are referred to as listener sockets throughout this
  39  * implementation because they are in the TCP_LISTEN state.  When a
  40  * connection request is received (the second kind of socket mentioned above),
  41  * we create a new socket and refer to it as a pending socket.  These pending
  42  * sockets are placed on the pending connection list of the listener socket.
  43  * When future packets are received for the address the listener socket is
  44  * bound to, we check if the source of the packet is from one that has an
  45  * existing pending connection.  If it does, we process the packet for the
  46  * pending socket.  When that socket reaches the connected state, it is removed
  47  * from the listener socket's pending list and enqueued in the listener
  48  * socket's accept queue.  Callers of accept(2) will accept connected sockets
  49  * from the listener socket's accept queue.  If the socket cannot be accepted
  50  * for some reason then it is marked rejected.  Once the connection is
  51  * accepted, it is owned by the user process and the responsibility for cleanup
  52  * falls with that user process.
  53  *
  54  * - It is possible that these pending sockets will never reach the connected
  55  * state; in fact, we may never receive another packet after the connection
  56  * request.  Because of this, we must schedule a cleanup function to run in the
  57  * future, after some amount of time passes where a connection should have been
  58  * established.  This function ensures that the socket is off all lists so it
  59  * cannot be retrieved, then drops all references to the socket so it is cleaned
  60  * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
  61  * function will also cleanup rejected sockets, those that reach the connected
  62  * state but leave it before they have been accepted.
  63  *
  64  * - Lock ordering for pending or accept queue sockets is:
  65  *
  66  *     lock_sock(listener);
  67  *     lock_sock_nested(pending, SINGLE_DEPTH_NESTING);
  68  *
  69  * Using explicit nested locking keeps lockdep happy since normally only one
  70  * lock of a given class may be taken at a time.
  71  *
  72  * - Sockets created by user action will be cleaned up when the user process
  73  * calls close(2), causing our release implementation to be called. Our release
  74  * implementation will perform some cleanup then drop the last reference so our
  75  * sk_destruct implementation is invoked.  Our sk_destruct implementation will
  76  * perform additional cleanup that's common for both types of sockets.
  77  *
  78  * - A socket's reference count is what ensures that the structure won't be
  79  * freed.  Each entry in a list (such as the "global" bound and connected tables
  80  * and the listener socket's pending list and connected queue) ensures a
  81  * reference.  When we defer work until process context and pass a socket as our
  82  * argument, we must ensure the reference count is increased to ensure the
  83  * socket isn't freed before the function is run; the deferred function will
  84  * then drop the reference.
  85  *
  86  * - sk->sk_state uses the TCP state constants because they are widely used by
  87  * other address families and exposed to userspace tools like ss(8):
  88  *
  89  *   TCP_CLOSE - unconnected
  90  *   TCP_SYN_SENT - connecting
  91  *   TCP_ESTABLISHED - connected
  92  *   TCP_CLOSING - disconnecting
  93  *   TCP_LISTEN - listening
  94  */
  95
  96 #include <linux/types.h>
  97 #include <linux/bitops.h>
  98 #include <linux/cred.h>
  99 #include <linux/init.h>
 100 #include <linux/io.h>
 101 #include <linux/kernel.h>
 102 #include <linux/sched/signal.h>
 103 #include <linux/kmod.h>
 104 #include <linux/list.h>
 105 #include <linux/miscdevice.h>
 106 #include <linux/module.h>
 107 #include <linux/mutex.h>
 108 #include <linux/net.h>
 109 #include <linux/poll.h>
 110 #include <linux/skbuff.h>
 111 #include <linux/smp.h>
 112 #include <linux/socket.h>
 113 #include <linux/stddef.h>
 114 #include <linux/unistd.h>
 115 #include <linux/wait.h>
 116 #include <linux/workqueue.h>
 117 #include <net/sock.h>
 118 #include <net/af_vsock.h>
 119
 120 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 121 static void vsock_sk_destruct(struct sock *sk);
 122 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 123
 124 /* Protocol family. */
 125 static struct proto vsock_proto = {
 126         .name = "AF_VSOCK",
 127         .owner = THIS_MODULE,
 128         .obj_size = sizeof(struct vsock_sock),
 129 };
 130
 131 /* The default peer timeout indicates how long we will wait for a peer response
 132  * to a control message.
 133  */
 134 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
 135
 136 static const struct vsock_transport *transport;
 137 static DEFINE_MUTEX(vsock_register_mutex);
 138
 139 /**** EXPORTS ****/
 140
 141 /* Get the ID of the local context.  This is transport dependent. */
 142
 143 int vm_sockets_get_local_cid(void)
 144 {
 145         return transport->get_local_cid();
 146 }
 147 EXPORT_SYMBOL_GPL(vm_sockets_get_local_cid);
 148
 149 /**** UTILS ****/
 150
 151 /* Each bound VSocket is stored in the bind hash table and each connected
 152  * VSocket is stored in the connected hash table.
 153  *
 154  * Unbound sockets are all put on the same list attached to the end of the hash
 155  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
 156  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
 157  * represents the list that addr hashes to).
 158  *
 159  * Specifically, we initialize the vsock_bind_table array to a size of
 160  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
 161  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
 162  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
 163  * mods with VSOCK_HASH_SIZE to ensure this.
 164  */
 165 #define MAX_PORT_RETRIES        24
 166
 167 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
 168 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
 169 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
 170
 171 /* XXX This can probably be implemented in a better way. */
 172 #define VSOCK_CONN_HASH(src, dst)                               \
 173         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
 174 #define vsock_connected_sockets(src, dst)               \
 175         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
 176 #define vsock_connected_sockets_vsk(vsk)                                \
 177         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
 178
 179 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
 180 EXPORT_SYMBOL_GPL(vsock_bind_table);
 181 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
 182 EXPORT_SYMBOL_GPL(vsock_connected_table);
 183 DEFINE_SPINLOCK(vsock_table_lock);
 184 EXPORT_SYMBOL_GPL(vsock_table_lock);
 185
 186 /* Autobind this socket to the local address if necessary. */
 187 static int vsock_auto_bind(struct vsock_sock *vsk)
 188 {
 189         struct sock *sk = sk_vsock(vsk);
 190         struct sockaddr_vm local_addr;
 191
 192         if (vsock_addr_bound(&vsk->local_addr))
 193                 return 0;
 194         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 195         return __vsock_bind(sk, &local_addr);
 196 }
 197
 198 static int __init vsock_init_tables(void)
 199 {
 200         int i;
 201
 202         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
 203                 INIT_LIST_HEAD(&vsock_bind_table[i]);
 204
 205         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
 206                 INIT_LIST_HEAD(&vsock_connected_table[i]);
 207         return 0;
 208 }
 209
 210 static void __vsock_insert_bound(struct list_head *list,
 211                                  struct vsock_sock *vsk)
 212 {
 213         sock_hold(&vsk->sk);
 214         list_add(&vsk->bound_table, list);
 215 }
 216
 217 static void __vsock_insert_connected(struct list_head *list,
 218                                      struct vsock_sock *vsk)
 219 {
 220         sock_hold(&vsk->sk);
 221         list_add(&vsk->connected_table, list);
 222 }
 223
 224 static void __vsock_remove_bound(struct vsock_sock *vsk)
 225 {
 226         list_del_init(&vsk->bound_table);
 227         sock_put(&vsk->sk);
 228 }
 229
 230 static void __vsock_remove_connected(struct vsock_sock *vsk)
 231 {
 232         list_del_init(&vsk->connected_table);
 233         sock_put(&vsk->sk);
 234 }
 235
 236 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
 237 {
 238         struct vsock_sock *vsk;
 239
 240         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table)
 241                 if (addr->svm_port == vsk->local_addr.svm_port)
 242                         return sk_vsock(vsk);
 243
 244         return NULL;
 245 }
 246
 247 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
 248                                                   struct sockaddr_vm *dst)
 249 {
 250         struct vsock_sock *vsk;
 251
 252         list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
 253                             connected_table) {
 254                 if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
 255                     dst->svm_port == vsk->local_addr.svm_port) {
 256                         return sk_vsock(vsk);
 257                 }
 258         }
 259
 260         return NULL;
 261 }
 262
 263 static void vsock_insert_unbound(struct vsock_sock *vsk)
 264 {
 265         spin_lock_bh(&vsock_table_lock);
 266         __vsock_insert_bound(vsock_unbound_sockets, vsk);
 267         spin_unlock_bh(&vsock_table_lock);
 268 }
 269
 270 void vsock_insert_connected(struct vsock_sock *vsk)
 271 {
 272         struct list_head *list = vsock_connected_sockets(
 273                 &vsk->remote_addr, &vsk->local_addr);
 274
 275         spin_lock_bh(&vsock_table_lock);
 276         __vsock_insert_connected(list, vsk);
 277         spin_unlock_bh(&vsock_table_lock);
 278 }
 279 EXPORT_SYMBOL_GPL(vsock_insert_connected);
 280
 281 void vsock_remove_bound(struct vsock_sock *vsk)
 282 {
 283         spin_lock_bh(&vsock_table_lock);
 284         __vsock_remove_bound(vsk);
 285         spin_unlock_bh(&vsock_table_lock);
 286 }
 287 EXPORT_SYMBOL_GPL(vsock_remove_bound);
 288
 289 void vsock_remove_connected(struct vsock_sock *vsk)
 290 {
 291         spin_lock_bh(&vsock_table_lock);
 292         __vsock_remove_connected(vsk);
 293         spin_unlock_bh(&vsock_table_lock);
 294 }
 295 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 296
 297 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 298 {
 299         struct sock *sk;
 300
 301         spin_lock_bh(&vsock_table_lock);
 302         sk = __vsock_find_bound_socket(addr);
 303         if (sk)
 304                 sock_hold(sk);
 305
 306         spin_unlock_bh(&vsock_table_lock);
 307
 308         return sk;
 309 }
 310 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 311
 312 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 313                                          struct sockaddr_vm *dst)
 314 {
 315         struct sock *sk;
 316
 317         spin_lock_bh(&vsock_table_lock);
 318         sk = __vsock_find_connected_socket(src, dst);
 319         if (sk)
 320                 sock_hold(sk);
 321
 322         spin_unlock_bh(&vsock_table_lock);
 323
 324         return sk;
 325 }
 326 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 327
 328 static bool vsock_in_bound_table(struct vsock_sock *vsk)
 329 {
 330         bool ret;
 331
 332         spin_lock_bh(&vsock_table_lock);
 333         ret = __vsock_in_bound_table(vsk);
 334         spin_unlock_bh(&vsock_table_lock);
 335
 336         return ret;
 337 }
 338
 339 static bool vsock_in_connected_table(struct vsock_sock *vsk)
 340 {
 341         bool ret;
 342
 343         spin_lock_bh(&vsock_table_lock);
 344         ret = __vsock_in_connected_table(vsk);
 345         spin_unlock_bh(&vsock_table_lock);
 346
 347         return ret;
 348 }
 349
 350 void vsock_remove_sock(struct vsock_sock *vsk)
 351 {
 352         if (vsock_in_bound_table(vsk))
 353                 vsock_remove_bound(vsk);
 354
 355         if (vsock_in_connected_table(vsk))
 356                 vsock_remove_connected(vsk);
 357 }
 358 EXPORT_SYMBOL_GPL(vsock_remove_sock);
 359
 360 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
 361 {
 362         int i;
 363
 364         spin_lock_bh(&vsock_table_lock);
 365
 366         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
 367                 struct vsock_sock *vsk;
 368                 list_for_each_entry(vsk, &vsock_connected_table[i],
 369                                     connected_table)
 370                         fn(sk_vsock(vsk));
 371         }
 372
 373         spin_unlock_bh(&vsock_table_lock);
 374 }
 375 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
 376
 377 void vsock_add_pending(struct sock *listener, struct sock *pending)
 378 {
 379         struct vsock_sock *vlistener;
 380         struct vsock_sock *vpending;
 381
 382         vlistener = vsock_sk(listener);
 383         vpending = vsock_sk(pending);
 384
 385         sock_hold(pending);
 386         sock_hold(listener);
 387         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 388 }
 389 EXPORT_SYMBOL_GPL(vsock_add_pending);
 390
 391 void vsock_remove_pending(struct sock *listener, struct sock *pending)
 392 {
 393         struct vsock_sock *vpending = vsock_sk(pending);
 394
 395         list_del_init(&vpending->pending_links);
 396         sock_put(listener);
 397         sock_put(pending);
 398 }
 399 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 400
 401 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 402 {
 403         struct vsock_sock *vlistener;
 404         struct vsock_sock *vconnected;
 405
 406         vlistener = vsock_sk(listener);
 407         vconnected = vsock_sk(connected);
 408
 409         sock_hold(connected);
 410         sock_hold(listener);
 411         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 412 }
 413 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 414
 415 static struct sock *vsock_dequeue_accept(struct sock *listener)
 416 {
 417         struct vsock_sock *vlistener;
 418         struct vsock_sock *vconnected;
 419
 420         vlistener = vsock_sk(listener);
 421
 422         if (list_empty(&vlistener->accept_queue))
 423                 return NULL;
 424
 425         vconnected = list_entry(vlistener->accept_queue.next,
 426                                 struct vsock_sock, accept_queue);
 427
 428         list_del_init(&vconnected->accept_queue);
 429         sock_put(listener);
 430         /* The caller will need a reference on the connected socket so we let
 431          * it call sock_put().
 432          */
 433
 434         return sk_vsock(vconnected);
 435 }
 436
 437 static bool vsock_is_accept_queue_empty(struct sock *sk)
 438 {
 439         struct vsock_sock *vsk = vsock_sk(sk);
 440         return list_empty(&vsk->accept_queue);
 441 }
 442
 443 static bool vsock_is_pending(struct sock *sk)
 444 {
 445         struct vsock_sock *vsk = vsock_sk(sk);
 446         return !list_empty(&vsk->pending_links);
 447 }
 448
 449 static int vsock_send_shutdown(struct sock *sk, int mode)
 450 {
 451         return transport->shutdown(vsock_sk(sk), mode);
 452 }
 453
 454 static void vsock_pending_work(struct work_struct *work)
 455 {
 456         struct sock *sk;
 457         struct sock *listener;
 458         struct vsock_sock *vsk;
 459         bool cleanup;
 460
 461         vsk = container_of(work, struct vsock_sock, pending_work.work);
 462         sk = sk_vsock(vsk);
 463         listener = vsk->listener;
 464         cleanup = true;
 465
 466         lock_sock(listener);
 467         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 468
 469         if (vsock_is_pending(sk)) {
 470                 vsock_remove_pending(listener, sk);
 471
 472                 listener->sk_ack_backlog--;
 473         } else if (!vsk->rejected) {
 474                 /* We are not on the pending list and accept() did not reject
 475                  * us, so we must have been accepted by our user process.  We
 476                  * just need to drop our references to the sockets and be on
 477                  * our way.
 478                  */
 479                 cleanup = false;
 480                 goto out;
 481         }
 482
 483         /* We need to remove ourself from the global connected sockets list so
 484          * incoming packets can't find this socket, and to reduce the reference
 485          * count.
 486          */
 487         if (vsock_in_connected_table(vsk))
 488                 vsock_remove_connected(vsk);
 489
 490         sk->sk_state = TCP_CLOSE;
 491
 492 out:
 493         release_sock(sk);
 494         release_sock(listener);
 495         if (cleanup)
 496                 sock_put(sk);
 497
 498         sock_put(sk);
 499         sock_put(listener);
 500 }
 501
 502 /**** SOCKET OPERATIONS ****/
 503
 504 static int __vsock_bind_stream(struct vsock_sock *vsk,
 505                                struct sockaddr_vm *addr)
 506 {
 507         static u32 port = LAST_RESERVED_PORT + 1;
 508         struct sockaddr_vm new_addr;
 509
 510         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 511
 512         if (addr->svm_port == VMADDR_PORT_ANY) {
 513                 bool found = false;
 514                 unsigned int i;
 515
 516                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
 517                         if (port <= LAST_RESERVED_PORT)
 518                                 port = LAST_RESERVED_PORT + 1;
 519
 520                         new_addr.svm_port = port++;
 521
 522                         if (!__vsock_find_bound_socket(&new_addr)) {
 523                                 found = true;
 524                                 break;
 525                         }
 526                 }
 527
 528                 if (!found)
 529                         return -EADDRNOTAVAIL;
 530         } else {
 531                 /* If port is in reserved range, ensure caller
 532                  * has necessary privileges.
 533                  */
 534                 if (addr->svm_port <= LAST_RESERVED_PORT &&
 535                     !capable(CAP_NET_BIND_SERVICE)) {
 536                         return -EACCES;
 537                 }
 538
 539                 if (__vsock_find_bound_socket(&new_addr))
 540                         return -EADDRINUSE;
 541         }
 542
 543         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
 544
 545         /* Remove stream sockets from the unbound list and add them to the hash
 546          * table for easy lookup by its address.  The unbound list is simply an
 547          * extra entry at the end of the hash table, a trick used by AF_UNIX.
 548          */
 549         __vsock_remove_bound(vsk);
 550         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
 551
 552         return 0;
 553 }
 554
 555 static int __vsock_bind_dgram(struct vsock_sock *vsk,
 556                               struct sockaddr_vm *addr)
 557 {
 558         return transport->dgram_bind(vsk, addr);
 559 }
 560
 561 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 562 {
 563         struct vsock_sock *vsk = vsock_sk(sk);
 564         u32 cid;
 565         int retval;
 566
 567         /* First ensure this socket isn't already bound. */
 568         if (vsock_addr_bound(&vsk->local_addr))
 569                 return -EINVAL;
 570
 571         /* Now bind to the provided address or select appropriate values if
 572          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
 573          * like AF_INET prevents binding to a non-local IP address (in most
 574          * cases), we only allow binding to the local CID.
 575          */
 576         cid = transport->get_local_cid();
 577         if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)
 578                 return -EADDRNOTAVAIL;
 579
 580         switch (sk->sk_socket->type) {
 581         case SOCK_STREAM:
 582                 spin_lock_bh(&vsock_table_lock);
 583                 retval = __vsock_bind_stream(vsk, addr);
 584                 spin_unlock_bh(&vsock_table_lock);
 585                 break;
 586
 587         case SOCK_DGRAM:
 588                 retval = __vsock_bind_dgram(vsk, addr);
 589                 break;
 590
 591         default:
 592                 retval = -EINVAL;
 593                 break;
 594         }
 595
 596         return retval;
 597 }
 598
 599 static void vsock_connect_timeout(struct work_struct *work);
 600
 601 struct sock *__vsock_create(struct net *net,
 602                             struct socket *sock,
 603                             struct sock *parent,
 604                             gfp_t priority,
 605                             unsigned short type,
 606                             int kern)
 607 {
 608         struct sock *sk;
 609         struct vsock_sock *psk;
 610         struct vsock_sock *vsk;
 611
 612         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 613         if (!sk)
 614                 return NULL;
 615
 616         sock_init_data(sock, sk);
 617
 618         /* sk->sk_type is normally set in sock_init_data, but only if sock is
 619          * non-NULL. We make sure that our sockets always have a type by
 620          * setting it here if needed.
 621          */
 622         if (!sock)
 623                 sk->sk_type = type;
 624
 625         vsk = vsock_sk(sk);
 626         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 627         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 628
 629         sk->sk_destruct = vsock_sk_destruct;
 630         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 631         sock_reset_flag(sk, SOCK_DONE);
 632
 633         INIT_LIST_HEAD(&vsk->bound_table);
 634         INIT_LIST_HEAD(&vsk->connected_table);
 635         vsk->listener = NULL;
 636         INIT_LIST_HEAD(&vsk->pending_links);
 637         INIT_LIST_HEAD(&vsk->accept_queue);
 638         vsk->rejected = false;
 639         vsk->sent_request = false;
 640         vsk->ignore_connecting_rst = false;
 641         vsk->peer_shutdown = 0;
 642         INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 643         INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 644
 645         psk = parent ? vsock_sk(parent) : NULL;
 646         if (parent) {
 647                 vsk->trusted = psk->trusted;
 648                 vsk->owner = get_cred(psk->owner);
 649                 vsk->connect_timeout = psk->connect_timeout;
 650         } else {
 651                 vsk->trusted = capable(CAP_NET_ADMIN);
 652                 vsk->owner = get_current_cred();
 653                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 654         }
 655
 656         if (transport->init(vsk, psk) < 0) {
 657                 sk_free(sk);
 658                 return NULL;
 659         }
 660
 661         if (sock)
 662                 vsock_insert_unbound(vsk);
 663
 664         return sk;
 665 }
 666 EXPORT_SYMBOL_GPL(__vsock_create);
 667
 668 static void __vsock_release(struct sock *sk)
 669 {
 670         if (sk) {
 671                 struct sk_buff *skb;
 672                 struct sock *pending;
 673                 struct vsock_sock *vsk;
 674
 675                 vsk = vsock_sk(sk);
 676                 pending = NULL; /* Compiler warning. */
 677
 678                 transport->release(vsk);
 679
 680                 lock_sock(sk);
 681                 sock_orphan(sk);
 682                 sk->sk_shutdown = SHUTDOWN_MASK;
 683
 684                 while ((skb = skb_dequeue(&sk->sk_receive_queue)))
 685                         kfree_skb(skb);
 686
 687                 /* Clean up any sockets that never were accepted. */
 688                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 689                         __vsock_release(pending);
 690                         sock_put(pending);
 691                 }
 692
 693                 release_sock(sk);
 694                 sock_put(sk);
 695         }
 696 }
 697
 698 static void vsock_sk_destruct(struct sock *sk)
 699 {
 700         struct vsock_sock *vsk = vsock_sk(sk);
 701
 702         transport->destruct(vsk);
 703
 704         /* When clearing these addresses, there's no need to set the family and
 705          * possibly register the address family with the kernel.
 706          */
 707         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 708         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 709
 710         put_cred(vsk->owner);
 711 }
 712
 713 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 714 {
 715         int err;
 716
 717         err = sock_queue_rcv_skb(sk, skb);
 718         if (err)
 719                 kfree_skb(skb);
 720
 721         return err;
 722 }
 723
 724 s64 vsock_stream_has_data(struct vsock_sock *vsk)
 725 {
 726         return transport->stream_has_data(vsk);
 727 }
 728 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 729
 730 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 731 {
 732         return transport->stream_has_space(vsk);
 733 }
 734 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 735
 736 static int vsock_release(struct socket *sock)
 737 {
 738         __vsock_release(sock->sk);
 739         sock->sk = NULL;
 740         sock->state = SS_FREE;
 741
 742         return 0;
 743 }
 744
 745 static int
 746 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 747 {
 748         int err;
 749         struct sock *sk;
 750         struct sockaddr_vm *vm_addr;
 751
 752         sk = sock->sk;
 753
 754         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 755                 return -EINVAL;
 756
 757         lock_sock(sk);
 758         err = __vsock_bind(sk, vm_addr);
 759         release_sock(sk);
 760
 761         return err;
 762 }
 763
 764 static int vsock_getname(struct socket *sock,
 765                          struct sockaddr *addr, int peer)
 766 {
 767         int err;
 768         struct sock *sk;
 769         struct vsock_sock *vsk;
 770         struct sockaddr_vm *vm_addr;
 771
 772         sk = sock->sk;
 773         vsk = vsock_sk(sk);
 774         err = 0;
 775
 776         lock_sock(sk);
 777
 778         if (peer) {
 779                 if (sock->state != SS_CONNECTED) {
 780                         err = -ENOTCONN;
 781                         goto out;
 782                 }
 783                 vm_addr = &vsk->remote_addr;
 784         } else {
 785                 vm_addr = &vsk->local_addr;
 786         }
 787
 788         if (!vm_addr) {
 789                 err = -EINVAL;
 790                 goto out;
 791         }
 792
 793         /* sys_getsockname() and sys_getpeername() pass us a
 794          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 795          * that macro is defined in socket.c instead of .h, so we hardcode its
 796          * value here.
 797          */
 798         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 799         memcpy(addr, vm_addr, sizeof(*vm_addr));
 800         err = sizeof(*vm_addr);
 801
 802 out:
 803         release_sock(sk);
 804         return err;
 805 }
 806
 807 static int vsock_shutdown(struct socket *sock, int mode)
 808 {
 809         int err;
 810         struct sock *sk;
 811
 812         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 813          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 814          * here like the other address families do.  Note also that the
 815          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 816          * which is what we want.
 817          */
 818         mode++;
 819
 820         if ((mode & ~SHUTDOWN_MASK) || !mode)
 821                 return -EINVAL;
 822
 823         /* If this is a STREAM socket and it is not connected then bail out
 824          * immediately.  If it is a DGRAM socket then we must first kick the
 825          * socket so that it wakes up from any sleeping calls, for example
 826          * recv(), and then afterwards return the error.
 827          */
 828
 829         sk = sock->sk;
 830         if (sock->state == SS_UNCONNECTED) {
 831                 err = -ENOTCONN;
 832                 if (sk->sk_type == SOCK_STREAM)
 833                         return err;
 834         } else {
 835                 sock->state = SS_DISCONNECTING;
 836                 err = 0;
 837         }
 838
 839         /* Receive and send shutdowns are treated alike. */
 840         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
 841         if (mode) {
 842                 lock_sock(sk);
 843                 sk->sk_shutdown |= mode;
 844                 sk->sk_state_change(sk);
 845                 release_sock(sk);
 846
 847                 if (sk->sk_type == SOCK_STREAM) {
 848                         sock_reset_flag(sk, SOCK_DONE);
 849                         vsock_send_shutdown(sk, mode);
 850                 }
 851         }
 852
 853         return err;
 854 }
 855
 856 static __poll_t vsock_poll(struct file *file, struct socket *sock,
 857                                poll_table *wait)
 858 {
 859         struct sock *sk;
 860         __poll_t mask;
 861         struct vsock_sock *vsk;
 862
 863         sk = sock->sk;
 864         vsk = vsock_sk(sk);
 865
 866         poll_wait(file, sk_sleep(sk), wait);
 867         mask = 0;
 868
 869         if (sk->sk_err)
 870                 /* Signify that there has been an error on this socket. */
 871                 mask |= EPOLLERR;
 872
 873         /* INET sockets treat local write shutdown and peer write shutdown as a
 874          * case of EPOLLHUP set.
 875          */
 876         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
 877             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
 878              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
 879                 mask |= EPOLLHUP;
 880         }
 881
 882         if (sk->sk_shutdown & RCV_SHUTDOWN ||
 883             vsk->peer_shutdown & SEND_SHUTDOWN) {
 884                 mask |= EPOLLRDHUP;
 885         }
 886
 887         if (sock->type == SOCK_DGRAM) {
 888                 /* For datagram sockets we can read if there is something in
 889                  * the queue and write as long as the socket isn't shutdown for
 890                  * sending.
 891                  */
 892                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
 893                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
 894                         mask |= EPOLLIN | EPOLLRDNORM;
 895                 }
 896
 897                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
 898                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
 899
 900         } else if (sock->type == SOCK_STREAM) {
 901                 lock_sock(sk);
 902
 903                 /* Listening sockets that have connections in their accept
 904                  * queue can be read.
 905                  */
 906                 if (sk->sk_state == TCP_LISTEN
 907                     && !vsock_is_accept_queue_empty(sk))
 908                         mask |= EPOLLIN | EPOLLRDNORM;
 909
 910                 /* If there is something in the queue then we can read. */
 911                 if (transport->stream_is_active(vsk) &&
 912                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
 913                         bool data_ready_now = false;
 914                         int ret = transport->notify_poll_in(
 915                                         vsk, 1, &data_ready_now);
 916                         if (ret < 0) {
 917                                 mask |= EPOLLERR;
 918                         } else {
 919                                 if (data_ready_now)
 920                                         mask |= EPOLLIN | EPOLLRDNORM;
 921
 922                         }
 923                 }
 924
 925                 /* Sockets whose connections have been closed, reset, or
 926                  * terminated should also be considered read, and we check the
 927                  * shutdown flag for that.
 928                  */
 929                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
 930                     vsk->peer_shutdown & SEND_SHUTDOWN) {
 931                         mask |= EPOLLIN | EPOLLRDNORM;
 932                 }
 933
 934                 /* Connected sockets that can produce data can be written. */
 935                 if (sk->sk_state == TCP_ESTABLISHED) {
 936                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 937                                 bool space_avail_now = false;
 938                                 int ret = transport->notify_poll_out(
 939                                                 vsk, 1, &space_avail_now);
 940                                 if (ret < 0) {
 941                                         mask |= EPOLLERR;
 942                                 } else {
 943                                         if (space_avail_now)
 944                                                 /* Remove EPOLLWRBAND since INET
 945                                                  * sockets are not setting it.
 946                                                  */
 947                                                 mask |= EPOLLOUT | EPOLLWRNORM;
 948
 949                                 }
 950                         }
 951                 }
 952
 953                 /* Simulate INET socket poll behaviors, which sets
 954                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
 955                  * but local send is not shutdown.
 956                  */
 957                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
 958                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
 959                                 mask |= EPOLLOUT | EPOLLWRNORM;
 960
 961                 }
 962
 963                 release_sock(sk);
 964         }
 965
 966         return mask;
 967 }
 968
 969 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 970                                size_t len)
 971 {
 972         int err;
 973         struct sock *sk;
 974         struct vsock_sock *vsk;
 975         struct sockaddr_vm *remote_addr;
 976
 977         if (msg->msg_flags & MSG_OOB)
 978                 return -EOPNOTSUPP;
 979
 980         /* For now, MSG_DONTWAIT is always assumed... */
 981         err = 0;
 982         sk = sock->sk;
 983         vsk = vsock_sk(sk);
 984
 985         lock_sock(sk);
 986
 987         err = vsock_auto_bind(vsk);
 988         if (err)
 989                 goto out;
 990
 991
 992         /* If the provided message contains an address, use that.  Otherwise
 993          * fall back on the socket's remote handle (if it has been connected).
 994          */
 995         if (msg->msg_name &&
 996             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
 997                             &remote_addr) == 0) {
 998                 /* Ensure this address is of the right type and is a valid
 999                  * destination.
1000                  */
1001
1002                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1003                         remote_addr->svm_cid = transport->get_local_cid();
1004
1005                 if (!vsock_addr_bound(remote_addr)) {
1006                         err = -EINVAL;
1007                         goto out;
1008                 }
1009         } else if (sock->state == SS_CONNECTED) {
1010                 remote_addr = &vsk->remote_addr;
1011
1012                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1013                         remote_addr->svm_cid = transport->get_local_cid();
1014
1015                 /* XXX Should connect() or this function ensure remote_addr is
1016                  * bound?
1017                  */
1018                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1019                         err = -EINVAL;
1020                         goto out;
1021                 }
1022         } else {
1023                 err = -EINVAL;
1024                 goto out;
1025         }
1026
1027         if (!transport->dgram_allow(remote_addr->svm_cid,
1028                                     remote_addr->svm_port)) {
1029                 err = -EINVAL;
1030                 goto out;
1031         }
1032
1033         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1034
1035 out:
1036         release_sock(sk);
1037         return err;
1038 }
1039
1040 static int vsock_dgram_connect(struct socket *sock,
1041                                struct sockaddr *addr, int addr_len, int flags)
1042 {
1043         int err;
1044         struct sock *sk;
1045         struct vsock_sock *vsk;
1046         struct sockaddr_vm *remote_addr;
1047
1048         sk = sock->sk;
1049         vsk = vsock_sk(sk);
1050
1051         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1052         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1053                 lock_sock(sk);
1054                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1055                                 VMADDR_PORT_ANY);
1056                 sock->state = SS_UNCONNECTED;
1057                 release_sock(sk);
1058                 return 0;
1059         } else if (err != 0)
1060                 return -EINVAL;
1061
1062         lock_sock(sk);
1063
1064         err = vsock_auto_bind(vsk);
1065         if (err)
1066                 goto out;
1067
1068         if (!transport->dgram_allow(remote_addr->svm_cid,
1069                                     remote_addr->svm_port)) {
1070                 err = -EINVAL;
1071                 goto out;
1072         }
1073
1074         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1075         sock->state = SS_CONNECTED;
1076
1077 out:
1078         release_sock(sk);
1079         return err;
1080 }
1081
1082 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1083                                size_t len, int flags)
1084 {
1085         return transport->dgram_dequeue(vsock_sk(sock->sk), msg, len, flags);
1086 }
1087
1088 static const struct proto_ops vsock_dgram_ops = {
1089         .family = PF_VSOCK,
1090         .owner = THIS_MODULE,
1091         .release = vsock_release,
1092         .bind = vsock_bind,
1093         .connect = vsock_dgram_connect,
1094         .socketpair = sock_no_socketpair,
1095         .accept = sock_no_accept,
1096         .getname = vsock_getname,
1097         .poll = vsock_poll,
1098         .ioctl = sock_no_ioctl,
1099         .listen = sock_no_listen,
1100         .shutdown = vsock_shutdown,
1101         .setsockopt = sock_no_setsockopt,
1102         .getsockopt = sock_no_getsockopt,
1103         .sendmsg = vsock_dgram_sendmsg,
1104         .recvmsg = vsock_dgram_recvmsg,
1105         .mmap = sock_no_mmap,
1106         .sendpage = sock_no_sendpage,
1107 };
1108
1109 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1110 {
1111         if (!transport->cancel_pkt)
1112                 return -EOPNOTSUPP;
1113
1114         return transport->cancel_pkt(vsk);
1115 }
1116
1117 static void vsock_connect_timeout(struct work_struct *work)
1118 {
1119         struct sock *sk;
1120         struct vsock_sock *vsk;
1121         int cancel = 0;
1122
1123         vsk = container_of(work, struct vsock_sock, connect_work.work);
1124         sk = sk_vsock(vsk);
1125
1126         lock_sock(sk);
1127         if (sk->sk_state == TCP_SYN_SENT &&
1128             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1129                 sk->sk_state = TCP_CLOSE;
1130                 sk->sk_err = ETIMEDOUT;
1131                 sk->sk_error_report(sk);
1132                 cancel = 1;
1133         }
1134         release_sock(sk);
1135         if (cancel)
1136                 vsock_transport_cancel_pkt(vsk);
1137
1138         sock_put(sk);
1139 }
1140
1141 static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
1142                                 int addr_len, int flags)
1143 {
1144         int err;
1145         struct sock *sk;
1146         struct vsock_sock *vsk;
1147         struct sockaddr_vm *remote_addr;
1148         long timeout;
1149         DEFINE_WAIT(wait);
1150
1151         err = 0;
1152         sk = sock->sk;
1153         vsk = vsock_sk(sk);
1154
1155         lock_sock(sk);
1156
1157         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1158         switch (sock->state) {
1159         case SS_CONNECTED:
1160                 err = -EISCONN;
1161                 goto out;
1162         case SS_DISCONNECTING:
1163                 err = -EINVAL;
1164                 goto out;
1165         case SS_CONNECTING:
1166                 /* This continues on so we can move sock into the SS_CONNECTED
1167                  * state once the connection has completed (at which point err
1168                  * will be set to zero also).  Otherwise, we will either wait
1169                  * for the connection or return -EALREADY should this be a
1170                  * non-blocking call.
1171                  */
1172                 err = -EALREADY;
1173                 break;
1174         default:
1175                 if ((sk->sk_state == TCP_LISTEN) ||
1176                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1177                         err = -EINVAL;
1178                         goto out;
1179                 }
1180
1181                 /* The hypervisor and well-known contexts do not have socket
1182                  * endpoints.
1183                  */
1184                 if (!transport->stream_allow(remote_addr->svm_cid,
1185                                              remote_addr->svm_port)) {
1186                         err = -ENETUNREACH;
1187                         goto out;
1188                 }
1189
1190                 /* Set the remote address that we are connecting to. */
1191                 memcpy(&vsk->remote_addr, remote_addr,
1192                        sizeof(vsk->remote_addr));
1193
1194                 err = vsock_auto_bind(vsk);
1195                 if (err)
1196                         goto out;
1197
1198                 sk->sk_state = TCP_SYN_SENT;
1199
1200                 err = transport->connect(vsk);
1201                 if (err < 0)
1202                         goto out;
1203
1204                 /* Mark sock as connecting and set the error code to in
1205                  * progress in case this is a non-blocking connect.
1206                  */
1207                 sock->state = SS_CONNECTING;
1208                 err = -EINPROGRESS;
1209         }
1210
1211         /* The receive path will handle all communication until we are able to
1212          * enter the connected state.  Here we wait for the connection to be
1213          * completed or a notification of an error.
1214          */
1215         timeout = vsk->connect_timeout;
1216         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1217
1218         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1219                 if (flags & O_NONBLOCK) {
1220                         /* If we're not going to block, we schedule a timeout
1221                          * function to generate a timeout on the connection
1222                          * attempt, in case the peer doesn't respond in a
1223                          * timely manner. We hold on to the socket until the
1224                          * timeout fires.
1225                          */
1226                         sock_hold(sk);
1227                         schedule_delayed_work(&vsk->connect_work, timeout);
1228
1229                         /* Skip ahead to preserve error code set above. */
1230                         goto out_wait;
1231                 }
1232
1233                 release_sock(sk);
1234                 timeout = schedule_timeout(timeout);
1235                 lock_sock(sk);
1236
1237                 if (signal_pending(current)) {
1238                         err = sock_intr_errno(timeout);
1239                         sk->sk_state = TCP_CLOSE;
1240                         sock->state = SS_UNCONNECTED;
1241                         vsock_transport_cancel_pkt(vsk);
1242                         goto out_wait;
1243                 } else if (timeout == 0) {
1244                         err = -ETIMEDOUT;
1245                         sk->sk_state = TCP_CLOSE;
1246                         sock->state = SS_UNCONNECTED;
1247                         vsock_transport_cancel_pkt(vsk);
1248                         goto out_wait;
1249                 }
1250
1251                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1252         }
1253
1254         if (sk->sk_err) {
1255                 err = -sk->sk_err;
1256                 sk->sk_state = TCP_CLOSE;
1257                 sock->state = SS_UNCONNECTED;
1258         } else {
1259                 err = 0;
1260         }
1261
1262 out_wait:
1263         finish_wait(sk_sleep(sk), &wait);
1264 out:
1265         release_sock(sk);
1266         return err;
1267 }
1268
1269 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1270                         bool kern)
1271 {
1272         struct sock *listener;
1273         int err;
1274         struct sock *connected;
1275         struct vsock_sock *vconnected;
1276         long timeout;
1277         DEFINE_WAIT(wait);
1278
1279         err = 0;
1280         listener = sock->sk;
1281
1282         lock_sock(listener);
1283
1284         if (sock->type != SOCK_STREAM) {
1285                 err = -EOPNOTSUPP;
1286                 goto out;
1287         }
1288
1289         if (listener->sk_state != TCP_LISTEN) {
1290                 err = -EINVAL;
1291                 goto out;
1292         }
1293
1294         /* Wait for children sockets to appear; these are the new sockets
1295          * created upon connection establishment.
1296          */
1297         timeout = sock_sndtimeo(listener, flags & O_NONBLOCK);
1298         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1299
1300         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1301                listener->sk_err == 0) {
1302                 release_sock(listener);
1303                 timeout = schedule_timeout(timeout);
1304                 finish_wait(sk_sleep(listener), &wait);
1305                 lock_sock(listener);
1306
1307                 if (signal_pending(current)) {
1308                         err = sock_intr_errno(timeout);
1309                         goto out;
1310                 } else if (timeout == 0) {
1311                         err = -EAGAIN;
1312                         goto out;
1313                 }
1314
1315                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1316         }
1317         finish_wait(sk_sleep(listener), &wait);
1318
1319         if (listener->sk_err)
1320                 err = -listener->sk_err;
1321
1322         if (connected) {
1323                 listener->sk_ack_backlog--;
1324
1325                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1326                 vconnected = vsock_sk(connected);
1327
1328                 /* If the listener socket has received an error, then we should
1329                  * reject this socket and return.  Note that we simply mark the
1330                  * socket rejected, drop our reference, and let the cleanup
1331                  * function handle the cleanup; the fact that we found it in
1332                  * the listener's accept queue guarantees that the cleanup
1333                  * function hasn't run yet.
1334                  */
1335                 if (err) {
1336                         vconnected->rejected = true;
1337                 } else {
1338                         newsock->state = SS_CONNECTED;
1339                         sock_graft(connected, newsock);
1340                 }
1341
1342                 release_sock(connected);
1343                 sock_put(connected);
1344         }
1345
1346 out:
1347         release_sock(listener);
1348         return err;
1349 }
1350
1351 static int vsock_listen(struct socket *sock, int backlog)
1352 {
1353         int err;
1354         struct sock *sk;
1355         struct vsock_sock *vsk;
1356
1357         sk = sock->sk;
1358
1359         lock_sock(sk);
1360
1361         if (sock->type != SOCK_STREAM) {
1362                 err = -EOPNOTSUPP;
1363                 goto out;
1364         }
1365
1366         if (sock->state != SS_UNCONNECTED) {
1367                 err = -EINVAL;
1368                 goto out;
1369         }
1370
1371         vsk = vsock_sk(sk);
1372
1373         if (!vsock_addr_bound(&vsk->local_addr)) {
1374                 err = -EINVAL;
1375                 goto out;
1376         }
1377
1378         sk->sk_max_ack_backlog = backlog;
1379         sk->sk_state = TCP_LISTEN;
1380
1381         err = 0;
1382
1383 out:
1384         release_sock(sk);
1385         return err;
1386 }
1387
1388 static int vsock_stream_setsockopt(struct socket *sock,
1389                                    int level,
1390                                    int optname,
1391                                    char __user *optval,
1392                                    unsigned int optlen)
1393 {
1394         int err;
1395         struct sock *sk;
1396         struct vsock_sock *vsk;
1397         u64 val;
1398
1399         if (level != AF_VSOCK)
1400                 return -ENOPROTOOPT;
1401
1402 #define COPY_IN(_v)                                       \
1403         do {                                              \
1404                 if (optlen < sizeof(_v)) {                \
1405                         err = -EINVAL;                    \
1406                         goto exit;                        \
1407                 }                                         \
1408                 if (copy_from_user(&_v, optval, sizeof(_v)) != 0) {     \
1409                         err = -EFAULT;                                  \
1410                         goto exit;                                      \
1411                 }                                                       \
1412         } while (0)
1413
1414         err = 0;
1415         sk = sock->sk;
1416         vsk = vsock_sk(sk);
1417
1418         lock_sock(sk);
1419
1420         switch (optname) {
1421         case SO_VM_SOCKETS_BUFFER_SIZE:
1422                 COPY_IN(val);
1423                 transport->set_buffer_size(vsk, val);
1424                 break;
1425
1426         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1427                 COPY_IN(val);
1428                 transport->set_max_buffer_size(vsk, val);
1429                 break;
1430
1431         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1432                 COPY_IN(val);
1433                 transport->set_min_buffer_size(vsk, val);
1434                 break;
1435
1436         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1437                 struct timeval tv;
1438                 COPY_IN(tv);
1439                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1440                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1441                         vsk->connect_timeout = tv.tv_sec * HZ +
1442                             DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1443                         if (vsk->connect_timeout == 0)
1444                                 vsk->connect_timeout =
1445                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1446
1447                 } else {
1448                         err = -ERANGE;
1449                 }
1450                 break;
1451         }
1452
1453         default:
1454                 err = -ENOPROTOOPT;
1455                 break;
1456         }
1457
1458 #undef COPY_IN
1459
1460 exit:
1461         release_sock(sk);
1462         return err;
1463 }
1464
1465 static int vsock_stream_getsockopt(struct socket *sock,
1466                                    int level, int optname,
1467                                    char __user *optval,
1468                                    int __user *optlen)
1469 {
1470         int err;
1471         int len;
1472         struct sock *sk;
1473         struct vsock_sock *vsk;
1474         u64 val;
1475
1476         if (level != AF_VSOCK)
1477                 return -ENOPROTOOPT;
1478
1479         err = get_user(len, optlen);
1480         if (err != 0)
1481                 return err;
1482
1483 #define COPY_OUT(_v)                            \
1484         do {                                    \
1485                 if (len < sizeof(_v))           \
1486                         return -EINVAL;         \
1487                                                 \
1488                 len = sizeof(_v);               \
1489                 if (copy_to_user(optval, &_v, len) != 0)        \
1490                         return -EFAULT;                         \
1491                                                                 \
1492         } while (0)
1493
1494         err = 0;
1495         sk = sock->sk;
1496         vsk = vsock_sk(sk);
1497
1498         switch (optname) {
1499         case SO_VM_SOCKETS_BUFFER_SIZE:
1500                 val = transport->get_buffer_size(vsk);
1501                 COPY_OUT(val);
1502                 break;
1503
1504         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1505                 val = transport->get_max_buffer_size(vsk);
1506                 COPY_OUT(val);
1507                 break;
1508
1509         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1510                 val = transport->get_min_buffer_size(vsk);
1511                 COPY_OUT(val);
1512                 break;
1513
1514         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1515                 struct timeval tv;
1516                 tv.tv_sec = vsk->connect_timeout / HZ;
1517                 tv.tv_usec =
1518                     (vsk->connect_timeout -
1519                      tv.tv_sec * HZ) * (1000000 / HZ);
1520                 COPY_OUT(tv);
1521                 break;
1522         }
1523         default:
1524                 return -ENOPROTOOPT;
1525         }
1526
1527         err = put_user(len, optlen);
1528         if (err != 0)
1529                 return -EFAULT;
1530
1531 #undef COPY_OUT
1532
1533         return 0;
1534 }
1535
1536 static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1537                                 size_t len)
1538 {
1539         struct sock *sk;
1540         struct vsock_sock *vsk;
1541         ssize_t total_written;
1542         long timeout;
1543         int err;
1544         struct vsock_transport_send_notify_data send_data;
1545         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1546
1547         sk = sock->sk;
1548         vsk = vsock_sk(sk);
1549         total_written = 0;
1550         err = 0;
1551
1552         if (msg->msg_flags & MSG_OOB)
1553                 return -EOPNOTSUPP;
1554
1555         lock_sock(sk);
1556
1557         /* Callers should not provide a destination with stream sockets. */
1558         if (msg->msg_namelen) {
1559                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1560                 goto out;
1561         }
1562
1563         /* Send data only if both sides are not shutdown in the direction. */
1564         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1565             vsk->peer_shutdown & RCV_SHUTDOWN) {
1566                 err = -EPIPE;
1567                 goto out;
1568         }
1569
1570         if (sk->sk_state != TCP_ESTABLISHED ||
1571             !vsock_addr_bound(&vsk->local_addr)) {
1572                 err = -ENOTCONN;
1573                 goto out;
1574         }
1575
1576         if (!vsock_addr_bound(&vsk->remote_addr)) {
1577                 err = -EDESTADDRREQ;
1578                 goto out;
1579         }
1580
1581         /* Wait for room in the produce queue to enqueue our user's data. */
1582         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1583
1584         err = transport->notify_send_init(vsk, &send_data);
1585         if (err < 0)
1586                 goto out;
1587
1588         while (total_written < len) {
1589                 ssize_t written;
1590
1591                 add_wait_queue(sk_sleep(sk), &wait);
1592                 while (vsock_stream_has_space(vsk) == 0 &&
1593                        sk->sk_err == 0 &&
1594                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1595                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1596
1597                         /* Don't wait for non-blocking sockets. */
1598                         if (timeout == 0) {
1599                                 err = -EAGAIN;
1600                                 remove_wait_queue(sk_sleep(sk), &wait);
1601                                 goto out_err;
1602                         }
1603
1604                         err = transport->notify_send_pre_block(vsk, &send_data);
1605                         if (err < 0) {
1606                                 remove_wait_queue(sk_sleep(sk), &wait);
1607                                 goto out_err;
1608                         }
1609
1610                         release_sock(sk);
1611                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1612                         lock_sock(sk);
1613                         if (signal_pending(current)) {
1614                                 err = sock_intr_errno(timeout);
1615                                 remove_wait_queue(sk_sleep(sk), &wait);
1616                                 goto out_err;
1617                         } else if (timeout == 0) {
1618                                 err = -EAGAIN;
1619                                 remove_wait_queue(sk_sleep(sk), &wait);
1620                                 goto out_err;
1621                         }
1622                 }
1623                 remove_wait_queue(sk_sleep(sk), &wait);
1624
1625                 /* These checks occur both as part of and after the loop
1626                  * conditional since we need to check before and after
1627                  * sleeping.
1628                  */
1629                 if (sk->sk_err) {
1630                         err = -sk->sk_err;
1631                         goto out_err;
1632                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1633                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1634                         err = -EPIPE;
1635                         goto out_err;
1636                 }
1637
1638                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1639                 if (err < 0)
1640                         goto out_err;
1641
1642                 /* Note that enqueue will only write as many bytes as are free
1643                  * in the produce queue, so we don't need to ensure len is
1644                  * smaller than the queue size.  It is the caller's
1645                  * responsibility to check how many bytes we were able to send.
1646                  */
1647
1648                 written = transport->stream_enqueue(
1649                                 vsk, msg,
1650                                 len - total_written);
1651                 if (written < 0) {
1652                         err = -ENOMEM;
1653                         goto out_err;
1654                 }
1655
1656                 total_written += written;
1657
1658                 err = transport->notify_send_post_enqueue(
1659                                 vsk, written, &send_data);
1660                 if (err < 0)
1661                         goto out_err;
1662
1663         }
1664
1665 out_err:
1666         if (total_written > 0)
1667                 err = total_written;
1668 out:
1669         release_sock(sk);
1670         return err;
1671 }
1672
1673
1674 static int
1675 vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1676                      int flags)
1677 {
1678         struct sock *sk;
1679         struct vsock_sock *vsk;
1680         int err;
1681         size_t target;
1682         ssize_t copied;
1683         long timeout;
1684         struct vsock_transport_recv_notify_data recv_data;
1685
1686         DEFINE_WAIT(wait);
1687
1688         sk = sock->sk;
1689         vsk = vsock_sk(sk);
1690         err = 0;
1691
1692         lock_sock(sk);
1693
1694         if (sk->sk_state != TCP_ESTABLISHED) {
1695                 /* Recvmsg is supposed to return 0 if a peer performs an
1696                  * orderly shutdown. Differentiate between that case and when a
1697                  * peer has not connected or a local shutdown occured with the
1698                  * SOCK_DONE flag.
1699                  */
1700                 if (sock_flag(sk, SOCK_DONE))
1701                         err = 0;
1702                 else
1703                         err = -ENOTCONN;
1704
1705                 goto out;
1706         }
1707
1708         if (flags & MSG_OOB) {
1709                 err = -EOPNOTSUPP;
1710                 goto out;
1711         }
1712
1713         /* We don't check peer_shutdown flag here since peer may actually shut
1714          * down, but there can be data in the queue that a local socket can
1715          * receive.
1716          */
1717         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1718                 err = 0;
1719                 goto out;
1720         }
1721
1722         /* It is valid on Linux to pass in a zero-length receive buffer.  This
1723          * is not an error.  We may as well bail out now.
1724          */
1725         if (!len) {
1726                 err = 0;
1727                 goto out;
1728         }
1729
1730         /* We must not copy less than target bytes into the user's buffer
1731          * before returning successfully, so we wait for the consume queue to
1732          * have that much data to consume before dequeueing.  Note that this
1733          * makes it impossible to handle cases where target is greater than the
1734          * queue size.
1735          */
1736         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1737         if (target >= transport->stream_rcvhiwat(vsk)) {
1738                 err = -ENOMEM;
1739                 goto out;
1740         }
1741         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1742         copied = 0;
1743
1744         err = transport->notify_recv_init(vsk, target, &recv_data);
1745         if (err < 0)
1746                 goto out;
1747
1748
1749         while (1) {
1750                 s64 ready;
1751
1752                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1753                 ready = vsock_stream_has_data(vsk);
1754
1755                 if (ready == 0) {
1756                         if (sk->sk_err != 0 ||
1757                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
1758                             (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1759                                 finish_wait(sk_sleep(sk), &wait);
1760                                 break;
1761                         }
1762                         /* Don't wait for non-blocking sockets. */
1763                         if (timeout == 0) {
1764                                 err = -EAGAIN;
1765                                 finish_wait(sk_sleep(sk), &wait);
1766                                 break;
1767                         }
1768
1769                         err = transport->notify_recv_pre_block(
1770                                         vsk, target, &recv_data);
1771                         if (err < 0) {
1772                                 finish_wait(sk_sleep(sk), &wait);
1773                                 break;
1774                         }
1775                         release_sock(sk);
1776                         timeout = schedule_timeout(timeout);
1777                         lock_sock(sk);
1778
1779                         if (signal_pending(current)) {
1780                                 err = sock_intr_errno(timeout);
1781                                 finish_wait(sk_sleep(sk), &wait);
1782                                 break;
1783                         } else if (timeout == 0) {
1784                                 err = -EAGAIN;
1785                                 finish_wait(sk_sleep(sk), &wait);
1786                                 break;
1787                         }
1788                 } else {
1789                         ssize_t read;
1790
1791                         finish_wait(sk_sleep(sk), &wait);
1792
1793                         if (ready < 0) {
1794                                 /* Invalid queue pair content. XXX This should
1795                                 * be changed to a connection reset in a later
1796                                 * change.
1797                                 */
1798
1799                                 err = -ENOMEM;
1800                                 goto out;
1801                         }
1802
1803                         err = transport->notify_recv_pre_dequeue(
1804                                         vsk, target, &recv_data);
1805                         if (err < 0)
1806                                 break;
1807
1808                         read = transport->stream_dequeue(
1809                                         vsk, msg,
1810                                         len - copied, flags);
1811                         if (read < 0) {
1812                                 err = -ENOMEM;
1813                                 break;
1814                         }
1815
1816                         copied += read;
1817
1818                         err = transport->notify_recv_post_dequeue(
1819                                         vsk, target, read,
1820                                         !(flags & MSG_PEEK), &recv_data);
1821                         if (err < 0)
1822                                 goto out;
1823
1824                         if (read >= target || flags & MSG_PEEK)
1825                                 break;
1826
1827                         target -= read;
1828                 }
1829         }
1830
1831         if (sk->sk_err)
1832                 err = -sk->sk_err;
1833         else if (sk->sk_shutdown & RCV_SHUTDOWN)
1834                 err = 0;
1835
1836         if (copied > 0)
1837                 err = copied;
1838
1839 out:
1840         release_sock(sk);
1841         return err;
1842 }
1843
1844 static const struct proto_ops vsock_stream_ops = {
1845         .family = PF_VSOCK,
1846         .owner = THIS_MODULE,
1847         .release = vsock_release,
1848         .bind = vsock_bind,
1849         .connect = vsock_stream_connect,
1850         .socketpair = sock_no_socketpair,
1851         .accept = vsock_accept,
1852         .getname = vsock_getname,
1853         .poll = vsock_poll,
1854         .ioctl = sock_no_ioctl,
1855         .listen = vsock_listen,
1856         .shutdown = vsock_shutdown,
1857         .setsockopt = vsock_stream_setsockopt,
1858         .getsockopt = vsock_stream_getsockopt,
1859         .sendmsg = vsock_stream_sendmsg,
1860         .recvmsg = vsock_stream_recvmsg,
1861         .mmap = sock_no_mmap,
1862         .sendpage = sock_no_sendpage,
1863 };
1864
1865 static int vsock_create(struct net *net, struct socket *sock,
1866                         int protocol, int kern)
1867 {
1868         if (!sock)
1869                 return -EINVAL;
1870
1871         if (protocol && protocol != PF_VSOCK)
1872                 return -EPROTONOSUPPORT;
1873
1874         switch (sock->type) {
1875         case SOCK_DGRAM:
1876                 sock->ops = &vsock_dgram_ops;
1877                 break;
1878         case SOCK_STREAM:
1879                 sock->ops = &vsock_stream_ops;
1880                 break;
1881         default:
1882                 return -ESOCKTNOSUPPORT;
1883         }
1884
1885         sock->state = SS_UNCONNECTED;
1886
1887         return __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern) ? 0 : -ENOMEM;
1888 }
1889
1890 static const struct net_proto_family vsock_family_ops = {
1891         .family = AF_VSOCK,
1892         .create = vsock_create,
1893         .owner = THIS_MODULE,
1894 };
1895
1896 static long vsock_dev_do_ioctl(struct file *filp,
1897                                unsigned int cmd, void __user *ptr)
1898 {
1899         u32 __user *p = ptr;
1900         int retval = 0;
1901
1902         switch (cmd) {
1903         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
1904                 if (put_user(transport->get_local_cid(), p) != 0)
1905                         retval = -EFAULT;
1906                 break;
1907
1908         default:
1909                 pr_err("Unknown ioctl %d\n", cmd);
1910                 retval = -EINVAL;
1911         }
1912
1913         return retval;
1914 }
1915
1916 static long vsock_dev_ioctl(struct file *filp,
1917                             unsigned int cmd, unsigned long arg)
1918 {
1919         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
1920 }
1921
1922 #ifdef CONFIG_COMPAT
1923 static long vsock_dev_compat_ioctl(struct file *filp,
1924                                    unsigned int cmd, unsigned long arg)
1925 {
1926         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
1927 }
1928 #endif
1929
1930 static const struct file_operations vsock_device_ops = {
1931         .owner          = THIS_MODULE,
1932         .unlocked_ioctl = vsock_dev_ioctl,
1933 #ifdef CONFIG_COMPAT
1934         .compat_ioctl   = vsock_dev_compat_ioctl,
1935 #endif
1936         .open           = nonseekable_open,
1937 };
1938
1939 static struct miscdevice vsock_device = {
1940         .name           = "vsock",
1941         .fops           = &vsock_device_ops,
1942 };
1943
1944 int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
1945 {
1946         int err = mutex_lock_interruptible(&vsock_register_mutex);
1947
1948         if (err)
1949                 return err;
1950
1951         if (transport) {
1952                 err = -EBUSY;
1953                 goto err_busy;
1954         }
1955
1956         /* Transport must be the owner of the protocol so that it can't
1957          * unload while there are open sockets.
1958          */
1959         vsock_proto.owner = owner;
1960         transport = t;
1961
1962         vsock_device.minor = MISC_DYNAMIC_MINOR;
1963         err = misc_register(&vsock_device);
1964         if (err) {
1965                 pr_err("Failed to register misc device\n");
1966                 goto err_reset_transport;
1967         }
1968
1969         err = proto_register(&vsock_proto, 1);  /* we want our slab */
1970         if (err) {
1971                 pr_err("Cannot register vsock protocol\n");
1972                 goto err_deregister_misc;
1973         }
1974
1975         err = sock_register(&vsock_family_ops);
1976         if (err) {
1977                 pr_err("could not register af_vsock (%d) address family: %d\n",
1978                        AF_VSOCK, err);
1979                 goto err_unregister_proto;
1980         }
1981
1982         mutex_unlock(&vsock_register_mutex);
1983         return 0;
1984
1985 err_unregister_proto:
1986         proto_unregister(&vsock_proto);
1987 err_deregister_misc:
1988         misc_deregister(&vsock_device);
1989 err_reset_transport:
1990         transport = NULL;
1991 err_busy:
1992         mutex_unlock(&vsock_register_mutex);
1993         return err;
1994 }
1995 EXPORT_SYMBOL_GPL(__vsock_core_init);
1996
1997 void vsock_core_exit(void)
1998 {
1999         mutex_lock(&vsock_register_mutex);
2000
2001         misc_deregister(&vsock_device);
2002         sock_unregister(AF_VSOCK);
2003         proto_unregister(&vsock_proto);
2004
2005         /* We do not want the assignment below re-ordered. */
2006         mb();
2007         transport = NULL;
2008
2009         mutex_unlock(&vsock_register_mutex);
2010 }
2011 EXPORT_SYMBOL_GPL(vsock_core_exit);
2012
2013 const struct vsock_transport *vsock_core_get_transport(void)
2014 {
2015         /* vsock_register_mutex not taken since only the transport uses this
2016          * function and only while registered.
2017          */
2018         return transport;
2019 }
2020 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2021
2022 static void __exit vsock_exit(void)
2023 {
2024         /* Do nothing.  This function makes this module removable. */
2025 }
2026
2027 module_init(vsock_init_tables);
2028 module_exit(vsock_exit);
2029
2030 MODULE_AUTHOR("VMware, Inc.");
2031 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2032 MODULE_VERSION("1.0.2.0-k");
2033 MODULE_LICENSE("GPL v2");