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/compat.h>
  89 #include <linux/types.h>
  90 #include <linux/bitops.h>
  91 #include <linux/cred.h>
  92 #include <linux/init.h>
  93 #include <linux/io.h>
  94 #include <linux/kernel.h>
  95 #include <linux/sched/signal.h>
  96 #include <linux/kmod.h>
  97 #include <linux/list.h>
  98 #include <linux/miscdevice.h>
  99 #include <linux/module.h>
 100 #include <linux/mutex.h>
 101 #include <linux/net.h>
 102 #include <linux/poll.h>
 103 #include <linux/random.h>
 104 #include <linux/skbuff.h>
 105 #include <linux/smp.h>
 106 #include <linux/socket.h>
 107 #include <linux/stddef.h>
 108 #include <linux/unistd.h>
 109 #include <linux/wait.h>
 110 #include <linux/workqueue.h>
 111 #include <net/sock.h>
 112 #include <net/af_vsock.h>
 113
 114 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 115 static void vsock_sk_destruct(struct sock *sk);
 116 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 117
 118 /* Protocol family. */
 119 static struct proto vsock_proto = {
 120         .name = "AF_VSOCK",
 121         .owner = THIS_MODULE,
 122         .obj_size = sizeof(struct vsock_sock),
 123 };
 124
 125 /* The default peer timeout indicates how long we will wait for a peer response
 126  * to a control message.
 127  */
 128 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
 129
 130 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
 131 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
 132 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
 133
 134 /* Transport used for host->guest communication */
 135 static const struct vsock_transport *transport_h2g;
 136 /* Transport used for guest->host communication */
 137 static const struct vsock_transport *transport_g2h;
 138 /* Transport used for DGRAM communication */
 139 static const struct vsock_transport *transport_dgram;
 140 /* Transport used for local communication */
 141 static const struct vsock_transport *transport_local;
 142 static DEFINE_MUTEX(vsock_register_mutex);
 143
 144 /**** UTILS ****/
 145
 146 /* Each bound VSocket is stored in the bind hash table and each connected
 147  * VSocket is stored in the connected hash table.
 148  *
 149  * Unbound sockets are all put on the same list attached to the end of the hash
 150  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
 151  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
 152  * represents the list that addr hashes to).
 153  *
 154  * Specifically, we initialize the vsock_bind_table array to a size of
 155  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
 156  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
 157  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
 158  * mods with VSOCK_HASH_SIZE to ensure this.
 159  */
 160 #define MAX_PORT_RETRIES        24
 161
 162 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
 163 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
 164 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
 165
 166 /* XXX This can probably be implemented in a better way. */
 167 #define VSOCK_CONN_HASH(src, dst)                               \
 168         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
 169 #define vsock_connected_sockets(src, dst)               \
 170         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
 171 #define vsock_connected_sockets_vsk(vsk)                                \
 172         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
 173
 174 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
 175 EXPORT_SYMBOL_GPL(vsock_bind_table);
 176 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
 177 EXPORT_SYMBOL_GPL(vsock_connected_table);
 178 DEFINE_SPINLOCK(vsock_table_lock);
 179 EXPORT_SYMBOL_GPL(vsock_table_lock);
 180
 181 /* Autobind this socket to the local address if necessary. */
 182 static int vsock_auto_bind(struct vsock_sock *vsk)
 183 {
 184         struct sock *sk = sk_vsock(vsk);
 185         struct sockaddr_vm local_addr;
 186
 187         if (vsock_addr_bound(&vsk->local_addr))
 188                 return 0;
 189         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 190         return __vsock_bind(sk, &local_addr);
 191 }
 192
 193 static void vsock_init_tables(void)
 194 {
 195         int i;
 196
 197         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
 198                 INIT_LIST_HEAD(&vsock_bind_table[i]);
 199
 200         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
 201                 INIT_LIST_HEAD(&vsock_connected_table[i]);
 202 }
 203
 204 static void __vsock_insert_bound(struct list_head *list,
 205                                  struct vsock_sock *vsk)
 206 {
 207         sock_hold(&vsk->sk);
 208         list_add(&vsk->bound_table, list);
 209 }
 210
 211 static void __vsock_insert_connected(struct list_head *list,
 212                                      struct vsock_sock *vsk)
 213 {
 214         sock_hold(&vsk->sk);
 215         list_add(&vsk->connected_table, list);
 216 }
 217
 218 static void __vsock_remove_bound(struct vsock_sock *vsk)
 219 {
 220         list_del_init(&vsk->bound_table);
 221         sock_put(&vsk->sk);
 222 }
 223
 224 static void __vsock_remove_connected(struct vsock_sock *vsk)
 225 {
 226         list_del_init(&vsk->connected_table);
 227         sock_put(&vsk->sk);
 228 }
 229
 230 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
 231 {
 232         struct vsock_sock *vsk;
 233
 234         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
 235                 if (vsock_addr_equals_addr(addr, &vsk->local_addr))
 236                         return sk_vsock(vsk);
 237
 238                 if (addr->svm_port == vsk->local_addr.svm_port &&
 239                     (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
 240                      addr->svm_cid == VMADDR_CID_ANY))
 241                         return sk_vsock(vsk);
 242         }
 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         if (__vsock_in_bound_table(vsk))
 285                 __vsock_remove_bound(vsk);
 286         spin_unlock_bh(&vsock_table_lock);
 287 }
 288 EXPORT_SYMBOL_GPL(vsock_remove_bound);
 289
 290 void vsock_remove_connected(struct vsock_sock *vsk)
 291 {
 292         spin_lock_bh(&vsock_table_lock);
 293         if (__vsock_in_connected_table(vsk))
 294                 __vsock_remove_connected(vsk);
 295         spin_unlock_bh(&vsock_table_lock);
 296 }
 297 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 298
 299 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 300 {
 301         struct sock *sk;
 302
 303         spin_lock_bh(&vsock_table_lock);
 304         sk = __vsock_find_bound_socket(addr);
 305         if (sk)
 306                 sock_hold(sk);
 307
 308         spin_unlock_bh(&vsock_table_lock);
 309
 310         return sk;
 311 }
 312 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 313
 314 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 315                                          struct sockaddr_vm *dst)
 316 {
 317         struct sock *sk;
 318
 319         spin_lock_bh(&vsock_table_lock);
 320         sk = __vsock_find_connected_socket(src, dst);
 321         if (sk)
 322                 sock_hold(sk);
 323
 324         spin_unlock_bh(&vsock_table_lock);
 325
 326         return sk;
 327 }
 328 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 329
 330 void vsock_remove_sock(struct vsock_sock *vsk)
 331 {
 332         vsock_remove_bound(vsk);
 333         vsock_remove_connected(vsk);
 334 }
 335 EXPORT_SYMBOL_GPL(vsock_remove_sock);
 336
 337 void vsock_for_each_connected_socket(struct vsock_transport *transport,
 338                                      void (*fn)(struct sock *sk))
 339 {
 340         int i;
 341
 342         spin_lock_bh(&vsock_table_lock);
 343
 344         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
 345                 struct vsock_sock *vsk;
 346                 list_for_each_entry(vsk, &vsock_connected_table[i],
 347                                     connected_table) {
 348                         if (vsk->transport != transport)
 349                                 continue;
 350
 351                         fn(sk_vsock(vsk));
 352                 }
 353         }
 354
 355         spin_unlock_bh(&vsock_table_lock);
 356 }
 357 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
 358
 359 void vsock_add_pending(struct sock *listener, struct sock *pending)
 360 {
 361         struct vsock_sock *vlistener;
 362         struct vsock_sock *vpending;
 363
 364         vlistener = vsock_sk(listener);
 365         vpending = vsock_sk(pending);
 366
 367         sock_hold(pending);
 368         sock_hold(listener);
 369         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 370 }
 371 EXPORT_SYMBOL_GPL(vsock_add_pending);
 372
 373 void vsock_remove_pending(struct sock *listener, struct sock *pending)
 374 {
 375         struct vsock_sock *vpending = vsock_sk(pending);
 376
 377         list_del_init(&vpending->pending_links);
 378         sock_put(listener);
 379         sock_put(pending);
 380 }
 381 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 382
 383 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 384 {
 385         struct vsock_sock *vlistener;
 386         struct vsock_sock *vconnected;
 387
 388         vlistener = vsock_sk(listener);
 389         vconnected = vsock_sk(connected);
 390
 391         sock_hold(connected);
 392         sock_hold(listener);
 393         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 394 }
 395 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 396
 397 static bool vsock_use_local_transport(unsigned int remote_cid)
 398 {
 399         if (!transport_local)
 400                 return false;
 401
 402         if (remote_cid == VMADDR_CID_LOCAL)
 403                 return true;
 404
 405         if (transport_g2h) {
 406                 return remote_cid == transport_g2h->get_local_cid();
 407         } else {
 408                 return remote_cid == VMADDR_CID_HOST;
 409         }
 410 }
 411
 412 static void vsock_deassign_transport(struct vsock_sock *vsk)
 413 {
 414         if (!vsk->transport)
 415                 return;
 416
 417         vsk->transport->destruct(vsk);
 418         module_put(vsk->transport->module);
 419         vsk->transport = NULL;
 420 }
 421
 422 /* Assign a transport to a socket and call the .init transport callback.
 423  *
 424  * Note: for connection oriented socket this must be called when vsk->remote_addr
 425  * is set (e.g. during the connect() or when a connection request on a listener
 426  * socket is received).
 427  * The vsk->remote_addr is used to decide which transport to use:
 428  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 429  *    g2h is not loaded, will use local transport;
 430  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 431  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 432  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 433  */
 434 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 435 {
 436         const struct vsock_transport *new_transport;
 437         struct sock *sk = sk_vsock(vsk);
 438         unsigned int remote_cid = vsk->remote_addr.svm_cid;
 439         __u8 remote_flags;
 440         int ret;
 441
 442         /* If the packet is coming with the source and destination CIDs higher
 443          * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 444          * forwarded to the host should be established. Then the host will
 445          * need to forward the packets to the guest.
 446          *
 447          * The flag is set on the (listen) receive path (psk is not NULL). On
 448          * the connect path the flag can be set by the user space application.
 449          */
 450         if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 451             vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 452                 vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 453
 454         remote_flags = vsk->remote_addr.svm_flags;
 455
 456         switch (sk->sk_type) {
 457         case SOCK_DGRAM:
 458                 new_transport = transport_dgram;
 459                 break;
 460         case SOCK_STREAM:
 461         case SOCK_SEQPACKET:
 462                 if (vsock_use_local_transport(remote_cid))
 463                         new_transport = transport_local;
 464                 else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 465                          (remote_flags & VMADDR_FLAG_TO_HOST))
 466                         new_transport = transport_g2h;
 467                 else
 468                         new_transport = transport_h2g;
 469                 break;
 470         default:
 471                 return -ESOCKTNOSUPPORT;
 472         }
 473
 474         if (vsk->transport) {
 475                 if (vsk->transport == new_transport)
 476                         return 0;
 477
 478                 /* transport->release() must be called with sock lock acquired.
 479                  * This path can only be taken during vsock_connect(), where we
 480                  * have already held the sock lock. In the other cases, this
 481                  * function is called on a new socket which is not assigned to
 482                  * any transport.
 483                  */
 484                 vsk->transport->release(vsk);
 485                 vsock_deassign_transport(vsk);
 486         }
 487
 488         /* We increase the module refcnt to prevent the transport unloading
 489          * while there are open sockets assigned to it.
 490          */
 491         if (!new_transport || !try_module_get(new_transport->module))
 492                 return -ENODEV;
 493
 494         if (sk->sk_type == SOCK_SEQPACKET) {
 495                 if (!new_transport->seqpacket_allow ||
 496                     !new_transport->seqpacket_allow(remote_cid)) {
 497                         module_put(new_transport->module);
 498                         return -ESOCKTNOSUPPORT;
 499                 }
 500         }
 501
 502         ret = new_transport->init(vsk, psk);
 503         if (ret) {
 504                 module_put(new_transport->module);
 505                 return ret;
 506         }
 507
 508         vsk->transport = new_transport;
 509
 510         return 0;
 511 }
 512 EXPORT_SYMBOL_GPL(vsock_assign_transport);
 513
 514 bool vsock_find_cid(unsigned int cid)
 515 {
 516         if (transport_g2h && cid == transport_g2h->get_local_cid())
 517                 return true;
 518
 519         if (transport_h2g && cid == VMADDR_CID_HOST)
 520                 return true;
 521
 522         if (transport_local && cid == VMADDR_CID_LOCAL)
 523                 return true;
 524
 525         return false;
 526 }
 527 EXPORT_SYMBOL_GPL(vsock_find_cid);
 528
 529 static struct sock *vsock_dequeue_accept(struct sock *listener)
 530 {
 531         struct vsock_sock *vlistener;
 532         struct vsock_sock *vconnected;
 533
 534         vlistener = vsock_sk(listener);
 535
 536         if (list_empty(&vlistener->accept_queue))
 537                 return NULL;
 538
 539         vconnected = list_entry(vlistener->accept_queue.next,
 540                                 struct vsock_sock, accept_queue);
 541
 542         list_del_init(&vconnected->accept_queue);
 543         sock_put(listener);
 544         /* The caller will need a reference on the connected socket so we let
 545          * it call sock_put().
 546          */
 547
 548         return sk_vsock(vconnected);
 549 }
 550
 551 static bool vsock_is_accept_queue_empty(struct sock *sk)
 552 {
 553         struct vsock_sock *vsk = vsock_sk(sk);
 554         return list_empty(&vsk->accept_queue);
 555 }
 556
 557 static bool vsock_is_pending(struct sock *sk)
 558 {
 559         struct vsock_sock *vsk = vsock_sk(sk);
 560         return !list_empty(&vsk->pending_links);
 561 }
 562
 563 static int vsock_send_shutdown(struct sock *sk, int mode)
 564 {
 565         struct vsock_sock *vsk = vsock_sk(sk);
 566
 567         if (!vsk->transport)
 568                 return -ENODEV;
 569
 570         return vsk->transport->shutdown(vsk, mode);
 571 }
 572
 573 static void vsock_pending_work(struct work_struct *work)
 574 {
 575         struct sock *sk;
 576         struct sock *listener;
 577         struct vsock_sock *vsk;
 578         bool cleanup;
 579
 580         vsk = container_of(work, struct vsock_sock, pending_work.work);
 581         sk = sk_vsock(vsk);
 582         listener = vsk->listener;
 583         cleanup = true;
 584
 585         lock_sock(listener);
 586         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 587
 588         if (vsock_is_pending(sk)) {
 589                 vsock_remove_pending(listener, sk);
 590
 591                 sk_acceptq_removed(listener);
 592         } else if (!vsk->rejected) {
 593                 /* We are not on the pending list and accept() did not reject
 594                  * us, so we must have been accepted by our user process.  We
 595                  * just need to drop our references to the sockets and be on
 596                  * our way.
 597                  */
 598                 cleanup = false;
 599                 goto out;
 600         }
 601
 602         /* We need to remove ourself from the global connected sockets list so
 603          * incoming packets can't find this socket, and to reduce the reference
 604          * count.
 605          */
 606         vsock_remove_connected(vsk);
 607
 608         sk->sk_state = TCP_CLOSE;
 609
 610 out:
 611         release_sock(sk);
 612         release_sock(listener);
 613         if (cleanup)
 614                 sock_put(sk);
 615
 616         sock_put(sk);
 617         sock_put(listener);
 618 }
 619
 620 /**** SOCKET OPERATIONS ****/
 621
 622 static int __vsock_bind_connectible(struct vsock_sock *vsk,
 623                                     struct sockaddr_vm *addr)
 624 {
 625         static u32 port;
 626         struct sockaddr_vm new_addr;
 627
 628         if (!port)
 629                 port = LAST_RESERVED_PORT + 1 +
 630                         prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
 631
 632         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 633
 634         if (addr->svm_port == VMADDR_PORT_ANY) {
 635                 bool found = false;
 636                 unsigned int i;
 637
 638                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
 639                         if (port <= LAST_RESERVED_PORT)
 640                                 port = LAST_RESERVED_PORT + 1;
 641
 642                         new_addr.svm_port = port++;
 643
 644                         if (!__vsock_find_bound_socket(&new_addr)) {
 645                                 found = true;
 646                                 break;
 647                         }
 648                 }
 649
 650                 if (!found)
 651                         return -EADDRNOTAVAIL;
 652         } else {
 653                 /* If port is in reserved range, ensure caller
 654                  * has necessary privileges.
 655                  */
 656                 if (addr->svm_port <= LAST_RESERVED_PORT &&
 657                     !capable(CAP_NET_BIND_SERVICE)) {
 658                         return -EACCES;
 659                 }
 660
 661                 if (__vsock_find_bound_socket(&new_addr))
 662                         return -EADDRINUSE;
 663         }
 664
 665         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
 666
 667         /* Remove connection oriented sockets from the unbound list and add them
 668          * to the hash table for easy lookup by its address.  The unbound list
 669          * is simply an extra entry at the end of the hash table, a trick used
 670          * by AF_UNIX.
 671          */
 672         __vsock_remove_bound(vsk);
 673         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
 674
 675         return 0;
 676 }
 677
 678 static int __vsock_bind_dgram(struct vsock_sock *vsk,
 679                               struct sockaddr_vm *addr)
 680 {
 681         return vsk->transport->dgram_bind(vsk, addr);
 682 }
 683
 684 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 685 {
 686         struct vsock_sock *vsk = vsock_sk(sk);
 687         int retval;
 688
 689         /* First ensure this socket isn't already bound. */
 690         if (vsock_addr_bound(&vsk->local_addr))
 691                 return -EINVAL;
 692
 693         /* Now bind to the provided address or select appropriate values if
 694          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
 695          * like AF_INET prevents binding to a non-local IP address (in most
 696          * cases), we only allow binding to a local CID.
 697          */
 698         if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
 699                 return -EADDRNOTAVAIL;
 700
 701         switch (sk->sk_socket->type) {
 702         case SOCK_STREAM:
 703         case SOCK_SEQPACKET:
 704                 spin_lock_bh(&vsock_table_lock);
 705                 retval = __vsock_bind_connectible(vsk, addr);
 706                 spin_unlock_bh(&vsock_table_lock);
 707                 break;
 708
 709         case SOCK_DGRAM:
 710                 retval = __vsock_bind_dgram(vsk, addr);
 711                 break;
 712
 713         default:
 714                 retval = -EINVAL;
 715                 break;
 716         }
 717
 718         return retval;
 719 }
 720
 721 static void vsock_connect_timeout(struct work_struct *work);
 722
 723 static struct sock *__vsock_create(struct net *net,
 724                                    struct socket *sock,
 725                                    struct sock *parent,
 726                                    gfp_t priority,
 727                                    unsigned short type,
 728                                    int kern)
 729 {
 730         struct sock *sk;
 731         struct vsock_sock *psk;
 732         struct vsock_sock *vsk;
 733
 734         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 735         if (!sk)
 736                 return NULL;
 737
 738         sock_init_data(sock, sk);
 739
 740         /* sk->sk_type is normally set in sock_init_data, but only if sock is
 741          * non-NULL. We make sure that our sockets always have a type by
 742          * setting it here if needed.
 743          */
 744         if (!sock)
 745                 sk->sk_type = type;
 746
 747         vsk = vsock_sk(sk);
 748         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 749         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 750
 751         sk->sk_destruct = vsock_sk_destruct;
 752         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 753         sock_reset_flag(sk, SOCK_DONE);
 754
 755         INIT_LIST_HEAD(&vsk->bound_table);
 756         INIT_LIST_HEAD(&vsk->connected_table);
 757         vsk->listener = NULL;
 758         INIT_LIST_HEAD(&vsk->pending_links);
 759         INIT_LIST_HEAD(&vsk->accept_queue);
 760         vsk->rejected = false;
 761         vsk->sent_request = false;
 762         vsk->ignore_connecting_rst = false;
 763         vsk->peer_shutdown = 0;
 764         INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 765         INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 766
 767         psk = parent ? vsock_sk(parent) : NULL;
 768         if (parent) {
 769                 vsk->trusted = psk->trusted;
 770                 vsk->owner = get_cred(psk->owner);
 771                 vsk->connect_timeout = psk->connect_timeout;
 772                 vsk->buffer_size = psk->buffer_size;
 773                 vsk->buffer_min_size = psk->buffer_min_size;
 774                 vsk->buffer_max_size = psk->buffer_max_size;
 775                 security_sk_clone(parent, sk);
 776         } else {
 777                 vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
 778                 vsk->owner = get_current_cred();
 779                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 780                 vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
 781                 vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
 782                 vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
 783         }
 784
 785         return sk;
 786 }
 787
 788 static bool sock_type_connectible(u16 type)
 789 {
 790         return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
 791 }
 792
 793 static void __vsock_release(struct sock *sk, int level)
 794 {
 795         if (sk) {
 796                 struct sock *pending;
 797                 struct vsock_sock *vsk;
 798
 799                 vsk = vsock_sk(sk);
 800                 pending = NULL; /* Compiler warning. */
 801
 802                 /* When "level" is SINGLE_DEPTH_NESTING, use the nested
 803                  * version to avoid the warning "possible recursive locking
 804                  * detected". When "level" is 0, lock_sock_nested(sk, level)
 805                  * is the same as lock_sock(sk).
 806                  */
 807                 lock_sock_nested(sk, level);
 808
 809                 if (vsk->transport)
 810                         vsk->transport->release(vsk);
 811                 else if (sock_type_connectible(sk->sk_type))
 812                         vsock_remove_sock(vsk);
 813
 814                 sock_orphan(sk);
 815                 sk->sk_shutdown = SHUTDOWN_MASK;
 816
 817                 skb_queue_purge(&sk->sk_receive_queue);
 818
 819                 /* Clean up any sockets that never were accepted. */
 820                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 821                         __vsock_release(pending, SINGLE_DEPTH_NESTING);
 822                         sock_put(pending);
 823                 }
 824
 825                 release_sock(sk);
 826                 sock_put(sk);
 827         }
 828 }
 829
 830 static void vsock_sk_destruct(struct sock *sk)
 831 {
 832         struct vsock_sock *vsk = vsock_sk(sk);
 833
 834         vsock_deassign_transport(vsk);
 835
 836         /* When clearing these addresses, there's no need to set the family and
 837          * possibly register the address family with the kernel.
 838          */
 839         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 840         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 841
 842         put_cred(vsk->owner);
 843 }
 844
 845 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 846 {
 847         int err;
 848
 849         err = sock_queue_rcv_skb(sk, skb);
 850         if (err)
 851                 kfree_skb(skb);
 852
 853         return err;
 854 }
 855
 856 struct sock *vsock_create_connected(struct sock *parent)
 857 {
 858         return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
 859                               parent->sk_type, 0);
 860 }
 861 EXPORT_SYMBOL_GPL(vsock_create_connected);
 862
 863 s64 vsock_stream_has_data(struct vsock_sock *vsk)
 864 {
 865         return vsk->transport->stream_has_data(vsk);
 866 }
 867 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 868
 869 static s64 vsock_connectible_has_data(struct vsock_sock *vsk)
 870 {
 871         struct sock *sk = sk_vsock(vsk);
 872
 873         if (sk->sk_type == SOCK_SEQPACKET)
 874                 return vsk->transport->seqpacket_has_data(vsk);
 875         else
 876                 return vsock_stream_has_data(vsk);
 877 }
 878
 879 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 880 {
 881         return vsk->transport->stream_has_space(vsk);
 882 }
 883 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 884
 885 static int vsock_release(struct socket *sock)
 886 {
 887         __vsock_release(sock->sk, 0);
 888         sock->sk = NULL;
 889         sock->state = SS_FREE;
 890
 891         return 0;
 892 }
 893
 894 static int
 895 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 896 {
 897         int err;
 898         struct sock *sk;
 899         struct sockaddr_vm *vm_addr;
 900
 901         sk = sock->sk;
 902
 903         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 904                 return -EINVAL;
 905
 906         lock_sock(sk);
 907         err = __vsock_bind(sk, vm_addr);
 908         release_sock(sk);
 909
 910         return err;
 911 }
 912
 913 static int vsock_getname(struct socket *sock,
 914                          struct sockaddr *addr, int peer)
 915 {
 916         int err;
 917         struct sock *sk;
 918         struct vsock_sock *vsk;
 919         struct sockaddr_vm *vm_addr;
 920
 921         sk = sock->sk;
 922         vsk = vsock_sk(sk);
 923         err = 0;
 924
 925         lock_sock(sk);
 926
 927         if (peer) {
 928                 if (sock->state != SS_CONNECTED) {
 929                         err = -ENOTCONN;
 930                         goto out;
 931                 }
 932                 vm_addr = &vsk->remote_addr;
 933         } else {
 934                 vm_addr = &vsk->local_addr;
 935         }
 936
 937         if (!vm_addr) {
 938                 err = -EINVAL;
 939                 goto out;
 940         }
 941
 942         /* sys_getsockname() and sys_getpeername() pass us a
 943          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 944          * that macro is defined in socket.c instead of .h, so we hardcode its
 945          * value here.
 946          */
 947         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 948         memcpy(addr, vm_addr, sizeof(*vm_addr));
 949         err = sizeof(*vm_addr);
 950
 951 out:
 952         release_sock(sk);
 953         return err;
 954 }
 955
 956 static int vsock_shutdown(struct socket *sock, int mode)
 957 {
 958         int err;
 959         struct sock *sk;
 960
 961         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 962          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 963          * here like the other address families do.  Note also that the
 964          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 965          * which is what we want.
 966          */
 967         mode++;
 968
 969         if ((mode & ~SHUTDOWN_MASK) || !mode)
 970                 return -EINVAL;
 971
 972         /* If this is a connection oriented socket and it is not connected then
 973          * bail out immediately.  If it is a DGRAM socket then we must first
 974          * kick the socket so that it wakes up from any sleeping calls, for
 975          * example recv(), and then afterwards return the error.
 976          */
 977
 978         sk = sock->sk;
 979
 980         lock_sock(sk);
 981         if (sock->state == SS_UNCONNECTED) {
 982                 err = -ENOTCONN;
 983                 if (sock_type_connectible(sk->sk_type))
 984                         goto out;
 985         } else {
 986                 sock->state = SS_DISCONNECTING;
 987                 err = 0;
 988         }
 989
 990         /* Receive and send shutdowns are treated alike. */
 991         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
 992         if (mode) {
 993                 sk->sk_shutdown |= mode;
 994                 sk->sk_state_change(sk);
 995
 996                 if (sock_type_connectible(sk->sk_type)) {
 997                         sock_reset_flag(sk, SOCK_DONE);
 998                         vsock_send_shutdown(sk, mode);
 999                 }
1000         }
1001
1002 out:
1003         release_sock(sk);
1004         return err;
1005 }
1006
1007 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1008                                poll_table *wait)
1009 {
1010         struct sock *sk;
1011         __poll_t mask;
1012         struct vsock_sock *vsk;
1013
1014         sk = sock->sk;
1015         vsk = vsock_sk(sk);
1016
1017         poll_wait(file, sk_sleep(sk), wait);
1018         mask = 0;
1019
1020         if (sk->sk_err)
1021                 /* Signify that there has been an error on this socket. */
1022                 mask |= EPOLLERR;
1023
1024         /* INET sockets treat local write shutdown and peer write shutdown as a
1025          * case of EPOLLHUP set.
1026          */
1027         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1028             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1029              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1030                 mask |= EPOLLHUP;
1031         }
1032
1033         if (sk->sk_shutdown & RCV_SHUTDOWN ||
1034             vsk->peer_shutdown & SEND_SHUTDOWN) {
1035                 mask |= EPOLLRDHUP;
1036         }
1037
1038         if (sock->type == SOCK_DGRAM) {
1039                 /* For datagram sockets we can read if there is something in
1040                  * the queue and write as long as the socket isn't shutdown for
1041                  * sending.
1042                  */
1043                 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1044                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
1045                         mask |= EPOLLIN | EPOLLRDNORM;
1046                 }
1047
1048                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1049                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1050
1051         } else if (sock_type_connectible(sk->sk_type)) {
1052                 const struct vsock_transport *transport;
1053
1054                 lock_sock(sk);
1055
1056                 transport = vsk->transport;
1057
1058                 /* Listening sockets that have connections in their accept
1059                  * queue can be read.
1060                  */
1061                 if (sk->sk_state == TCP_LISTEN
1062                     && !vsock_is_accept_queue_empty(sk))
1063                         mask |= EPOLLIN | EPOLLRDNORM;
1064
1065                 /* If there is something in the queue then we can read. */
1066                 if (transport && transport->stream_is_active(vsk) &&
1067                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1068                         bool data_ready_now = false;
1069                         int ret = transport->notify_poll_in(
1070                                         vsk, 1, &data_ready_now);
1071                         if (ret < 0) {
1072                                 mask |= EPOLLERR;
1073                         } else {
1074                                 if (data_ready_now)
1075                                         mask |= EPOLLIN | EPOLLRDNORM;
1076
1077                         }
1078                 }
1079
1080                 /* Sockets whose connections have been closed, reset, or
1081                  * terminated should also be considered read, and we check the
1082                  * shutdown flag for that.
1083                  */
1084                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
1085                     vsk->peer_shutdown & SEND_SHUTDOWN) {
1086                         mask |= EPOLLIN | EPOLLRDNORM;
1087                 }
1088
1089                 /* Connected sockets that can produce data can be written. */
1090                 if (transport && sk->sk_state == TCP_ESTABLISHED) {
1091                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1092                                 bool space_avail_now = false;
1093                                 int ret = transport->notify_poll_out(
1094                                                 vsk, 1, &space_avail_now);
1095                                 if (ret < 0) {
1096                                         mask |= EPOLLERR;
1097                                 } else {
1098                                         if (space_avail_now)
1099                                                 /* Remove EPOLLWRBAND since INET
1100                                                  * sockets are not setting it.
1101                                                  */
1102                                                 mask |= EPOLLOUT | EPOLLWRNORM;
1103
1104                                 }
1105                         }
1106                 }
1107
1108                 /* Simulate INET socket poll behaviors, which sets
1109                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1110                  * but local send is not shutdown.
1111                  */
1112                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1113                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1114                                 mask |= EPOLLOUT | EPOLLWRNORM;
1115
1116                 }
1117
1118                 release_sock(sk);
1119         }
1120
1121         return mask;
1122 }
1123
1124 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1125                                size_t len)
1126 {
1127         int err;
1128         struct sock *sk;
1129         struct vsock_sock *vsk;
1130         struct sockaddr_vm *remote_addr;
1131         const struct vsock_transport *transport;
1132
1133         if (msg->msg_flags & MSG_OOB)
1134                 return -EOPNOTSUPP;
1135
1136         /* For now, MSG_DONTWAIT is always assumed... */
1137         err = 0;
1138         sk = sock->sk;
1139         vsk = vsock_sk(sk);
1140
1141         lock_sock(sk);
1142
1143         transport = vsk->transport;
1144
1145         err = vsock_auto_bind(vsk);
1146         if (err)
1147                 goto out;
1148
1149
1150         /* If the provided message contains an address, use that.  Otherwise
1151          * fall back on the socket's remote handle (if it has been connected).
1152          */
1153         if (msg->msg_name &&
1154             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1155                             &remote_addr) == 0) {
1156                 /* Ensure this address is of the right type and is a valid
1157                  * destination.
1158                  */
1159
1160                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1161                         remote_addr->svm_cid = transport->get_local_cid();
1162
1163                 if (!vsock_addr_bound(remote_addr)) {
1164                         err = -EINVAL;
1165                         goto out;
1166                 }
1167         } else if (sock->state == SS_CONNECTED) {
1168                 remote_addr = &vsk->remote_addr;
1169
1170                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1171                         remote_addr->svm_cid = transport->get_local_cid();
1172
1173                 /* XXX Should connect() or this function ensure remote_addr is
1174                  * bound?
1175                  */
1176                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1177                         err = -EINVAL;
1178                         goto out;
1179                 }
1180         } else {
1181                 err = -EINVAL;
1182                 goto out;
1183         }
1184
1185         if (!transport->dgram_allow(remote_addr->svm_cid,
1186                                     remote_addr->svm_port)) {
1187                 err = -EINVAL;
1188                 goto out;
1189         }
1190
1191         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1192
1193 out:
1194         release_sock(sk);
1195         return err;
1196 }
1197
1198 static int vsock_dgram_connect(struct socket *sock,
1199                                struct sockaddr *addr, int addr_len, int flags)
1200 {
1201         int err;
1202         struct sock *sk;
1203         struct vsock_sock *vsk;
1204         struct sockaddr_vm *remote_addr;
1205
1206         sk = sock->sk;
1207         vsk = vsock_sk(sk);
1208
1209         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1210         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1211                 lock_sock(sk);
1212                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1213                                 VMADDR_PORT_ANY);
1214                 sock->state = SS_UNCONNECTED;
1215                 release_sock(sk);
1216                 return 0;
1217         } else if (err != 0)
1218                 return -EINVAL;
1219
1220         lock_sock(sk);
1221
1222         err = vsock_auto_bind(vsk);
1223         if (err)
1224                 goto out;
1225
1226         if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1227                                          remote_addr->svm_port)) {
1228                 err = -EINVAL;
1229                 goto out;
1230         }
1231
1232         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1233         sock->state = SS_CONNECTED;
1234
1235 out:
1236         release_sock(sk);
1237         return err;
1238 }
1239
1240 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1241                                size_t len, int flags)
1242 {
1243         struct vsock_sock *vsk = vsock_sk(sock->sk);
1244
1245         return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1246 }
1247
1248 static const struct proto_ops vsock_dgram_ops = {
1249         .family = PF_VSOCK,
1250         .owner = THIS_MODULE,
1251         .release = vsock_release,
1252         .bind = vsock_bind,
1253         .connect = vsock_dgram_connect,
1254         .socketpair = sock_no_socketpair,
1255         .accept = sock_no_accept,
1256         .getname = vsock_getname,
1257         .poll = vsock_poll,
1258         .ioctl = sock_no_ioctl,
1259         .listen = sock_no_listen,
1260         .shutdown = vsock_shutdown,
1261         .sendmsg = vsock_dgram_sendmsg,
1262         .recvmsg = vsock_dgram_recvmsg,
1263         .mmap = sock_no_mmap,
1264         .sendpage = sock_no_sendpage,
1265 };
1266
1267 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1268 {
1269         const struct vsock_transport *transport = vsk->transport;
1270
1271         if (!transport || !transport->cancel_pkt)
1272                 return -EOPNOTSUPP;
1273
1274         return transport->cancel_pkt(vsk);
1275 }
1276
1277 static void vsock_connect_timeout(struct work_struct *work)
1278 {
1279         struct sock *sk;
1280         struct vsock_sock *vsk;
1281
1282         vsk = container_of(work, struct vsock_sock, connect_work.work);
1283         sk = sk_vsock(vsk);
1284
1285         lock_sock(sk);
1286         if (sk->sk_state == TCP_SYN_SENT &&
1287             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1288                 sk->sk_state = TCP_CLOSE;
1289                 sk->sk_socket->state = SS_UNCONNECTED;
1290                 sk->sk_err = ETIMEDOUT;
1291                 sk_error_report(sk);
1292                 vsock_transport_cancel_pkt(vsk);
1293         }
1294         release_sock(sk);
1295
1296         sock_put(sk);
1297 }
1298
1299 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1300                          int addr_len, int flags)
1301 {
1302         int err;
1303         struct sock *sk;
1304         struct vsock_sock *vsk;
1305         const struct vsock_transport *transport;
1306         struct sockaddr_vm *remote_addr;
1307         long timeout;
1308         DEFINE_WAIT(wait);
1309
1310         err = 0;
1311         sk = sock->sk;
1312         vsk = vsock_sk(sk);
1313
1314         lock_sock(sk);
1315
1316         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1317         switch (sock->state) {
1318         case SS_CONNECTED:
1319                 err = -EISCONN;
1320                 goto out;
1321         case SS_DISCONNECTING:
1322                 err = -EINVAL;
1323                 goto out;
1324         case SS_CONNECTING:
1325                 /* This continues on so we can move sock into the SS_CONNECTED
1326                  * state once the connection has completed (at which point err
1327                  * will be set to zero also).  Otherwise, we will either wait
1328                  * for the connection or return -EALREADY should this be a
1329                  * non-blocking call.
1330                  */
1331                 err = -EALREADY;
1332                 if (flags & O_NONBLOCK)
1333                         goto out;
1334                 break;
1335         default:
1336                 if ((sk->sk_state == TCP_LISTEN) ||
1337                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1338                         err = -EINVAL;
1339                         goto out;
1340                 }
1341
1342                 /* Set the remote address that we are connecting to. */
1343                 memcpy(&vsk->remote_addr, remote_addr,
1344                        sizeof(vsk->remote_addr));
1345
1346                 err = vsock_assign_transport(vsk, NULL);
1347                 if (err)
1348                         goto out;
1349
1350                 transport = vsk->transport;
1351
1352                 /* The hypervisor and well-known contexts do not have socket
1353                  * endpoints.
1354                  */
1355                 if (!transport ||
1356                     !transport->stream_allow(remote_addr->svm_cid,
1357                                              remote_addr->svm_port)) {
1358                         err = -ENETUNREACH;
1359                         goto out;
1360                 }
1361
1362                 err = vsock_auto_bind(vsk);
1363                 if (err)
1364                         goto out;
1365
1366                 sk->sk_state = TCP_SYN_SENT;
1367
1368                 err = transport->connect(vsk);
1369                 if (err < 0)
1370                         goto out;
1371
1372                 /* Mark sock as connecting and set the error code to in
1373                  * progress in case this is a non-blocking connect.
1374                  */
1375                 sock->state = SS_CONNECTING;
1376                 err = -EINPROGRESS;
1377         }
1378
1379         /* The receive path will handle all communication until we are able to
1380          * enter the connected state.  Here we wait for the connection to be
1381          * completed or a notification of an error.
1382          */
1383         timeout = vsk->connect_timeout;
1384         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1385
1386         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1387                 if (flags & O_NONBLOCK) {
1388                         /* If we're not going to block, we schedule a timeout
1389                          * function to generate a timeout on the connection
1390                          * attempt, in case the peer doesn't respond in a
1391                          * timely manner. We hold on to the socket until the
1392                          * timeout fires.
1393                          */
1394                         sock_hold(sk);
1395
1396                         /* If the timeout function is already scheduled,
1397                          * reschedule it, then ungrab the socket refcount to
1398                          * keep it balanced.
1399                          */
1400                         if (mod_delayed_work(system_wq, &vsk->connect_work,
1401                                              timeout))
1402                                 sock_put(sk);
1403
1404                         /* Skip ahead to preserve error code set above. */
1405                         goto out_wait;
1406                 }
1407
1408                 release_sock(sk);
1409                 timeout = schedule_timeout(timeout);
1410                 lock_sock(sk);
1411
1412                 if (signal_pending(current)) {
1413                         err = sock_intr_errno(timeout);
1414                         sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1415                         sock->state = SS_UNCONNECTED;
1416                         vsock_transport_cancel_pkt(vsk);
1417                         vsock_remove_connected(vsk);
1418                         goto out_wait;
1419                 } else if (timeout == 0) {
1420                         err = -ETIMEDOUT;
1421                         sk->sk_state = TCP_CLOSE;
1422                         sock->state = SS_UNCONNECTED;
1423                         vsock_transport_cancel_pkt(vsk);
1424                         goto out_wait;
1425                 }
1426
1427                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1428         }
1429
1430         if (sk->sk_err) {
1431                 err = -sk->sk_err;
1432                 sk->sk_state = TCP_CLOSE;
1433                 sock->state = SS_UNCONNECTED;
1434         } else {
1435                 err = 0;
1436         }
1437
1438 out_wait:
1439         finish_wait(sk_sleep(sk), &wait);
1440 out:
1441         release_sock(sk);
1442         return err;
1443 }
1444
1445 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1446                         bool kern)
1447 {
1448         struct sock *listener;
1449         int err;
1450         struct sock *connected;
1451         struct vsock_sock *vconnected;
1452         long timeout;
1453         DEFINE_WAIT(wait);
1454
1455         err = 0;
1456         listener = sock->sk;
1457
1458         lock_sock(listener);
1459
1460         if (!sock_type_connectible(sock->type)) {
1461                 err = -EOPNOTSUPP;
1462                 goto out;
1463         }
1464
1465         if (listener->sk_state != TCP_LISTEN) {
1466                 err = -EINVAL;
1467                 goto out;
1468         }
1469
1470         /* Wait for children sockets to appear; these are the new sockets
1471          * created upon connection establishment.
1472          */
1473         timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1474         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1475
1476         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1477                listener->sk_err == 0) {
1478                 release_sock(listener);
1479                 timeout = schedule_timeout(timeout);
1480                 finish_wait(sk_sleep(listener), &wait);
1481                 lock_sock(listener);
1482
1483                 if (signal_pending(current)) {
1484                         err = sock_intr_errno(timeout);
1485                         goto out;
1486                 } else if (timeout == 0) {
1487                         err = -EAGAIN;
1488                         goto out;
1489                 }
1490
1491                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1492         }
1493         finish_wait(sk_sleep(listener), &wait);
1494
1495         if (listener->sk_err)
1496                 err = -listener->sk_err;
1497
1498         if (connected) {
1499                 sk_acceptq_removed(listener);
1500
1501                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1502                 vconnected = vsock_sk(connected);
1503
1504                 /* If the listener socket has received an error, then we should
1505                  * reject this socket and return.  Note that we simply mark the
1506                  * socket rejected, drop our reference, and let the cleanup
1507                  * function handle the cleanup; the fact that we found it in
1508                  * the listener's accept queue guarantees that the cleanup
1509                  * function hasn't run yet.
1510                  */
1511                 if (err) {
1512                         vconnected->rejected = true;
1513                 } else {
1514                         newsock->state = SS_CONNECTED;
1515                         sock_graft(connected, newsock);
1516                 }
1517
1518                 release_sock(connected);
1519                 sock_put(connected);
1520         }
1521
1522 out:
1523         release_sock(listener);
1524         return err;
1525 }
1526
1527 static int vsock_listen(struct socket *sock, int backlog)
1528 {
1529         int err;
1530         struct sock *sk;
1531         struct vsock_sock *vsk;
1532
1533         sk = sock->sk;
1534
1535         lock_sock(sk);
1536
1537         if (!sock_type_connectible(sk->sk_type)) {
1538                 err = -EOPNOTSUPP;
1539                 goto out;
1540         }
1541
1542         if (sock->state != SS_UNCONNECTED) {
1543                 err = -EINVAL;
1544                 goto out;
1545         }
1546
1547         vsk = vsock_sk(sk);
1548
1549         if (!vsock_addr_bound(&vsk->local_addr)) {
1550                 err = -EINVAL;
1551                 goto out;
1552         }
1553
1554         sk->sk_max_ack_backlog = backlog;
1555         sk->sk_state = TCP_LISTEN;
1556
1557         err = 0;
1558
1559 out:
1560         release_sock(sk);
1561         return err;
1562 }
1563
1564 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1565                                      const struct vsock_transport *transport,
1566                                      u64 val)
1567 {
1568         if (val > vsk->buffer_max_size)
1569                 val = vsk->buffer_max_size;
1570
1571         if (val < vsk->buffer_min_size)
1572                 val = vsk->buffer_min_size;
1573
1574         if (val != vsk->buffer_size &&
1575             transport && transport->notify_buffer_size)
1576                 transport->notify_buffer_size(vsk, &val);
1577
1578         vsk->buffer_size = val;
1579 }
1580
1581 static int vsock_connectible_setsockopt(struct socket *sock,
1582                                         int level,
1583                                         int optname,
1584                                         sockptr_t optval,
1585                                         unsigned int optlen)
1586 {
1587         int err;
1588         struct sock *sk;
1589         struct vsock_sock *vsk;
1590         const struct vsock_transport *transport;
1591         u64 val;
1592
1593         if (level != AF_VSOCK)
1594                 return -ENOPROTOOPT;
1595
1596 #define COPY_IN(_v)                                       \
1597         do {                                              \
1598                 if (optlen < sizeof(_v)) {                \
1599                         err = -EINVAL;                    \
1600                         goto exit;                        \
1601                 }                                         \
1602                 if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {  \
1603                         err = -EFAULT;                                  \
1604                         goto exit;                                      \
1605                 }                                                       \
1606         } while (0)
1607
1608         err = 0;
1609         sk = sock->sk;
1610         vsk = vsock_sk(sk);
1611
1612         lock_sock(sk);
1613
1614         transport = vsk->transport;
1615
1616         switch (optname) {
1617         case SO_VM_SOCKETS_BUFFER_SIZE:
1618                 COPY_IN(val);
1619                 vsock_update_buffer_size(vsk, transport, val);
1620                 break;
1621
1622         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1623                 COPY_IN(val);
1624                 vsk->buffer_max_size = val;
1625                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1626                 break;
1627
1628         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1629                 COPY_IN(val);
1630                 vsk->buffer_min_size = val;
1631                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1632                 break;
1633
1634         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1635         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1636                 struct __kernel_sock_timeval tv;
1637
1638                 err = sock_copy_user_timeval(&tv, optval, optlen,
1639                                              optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1640                 if (err)
1641                         break;
1642                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1643                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1644                         vsk->connect_timeout = tv.tv_sec * HZ +
1645                                 DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1646                         if (vsk->connect_timeout == 0)
1647                                 vsk->connect_timeout =
1648                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1649
1650                 } else {
1651                         err = -ERANGE;
1652                 }
1653                 break;
1654         }
1655
1656         default:
1657                 err = -ENOPROTOOPT;
1658                 break;
1659         }
1660
1661 #undef COPY_IN
1662
1663 exit:
1664         release_sock(sk);
1665         return err;
1666 }
1667
1668 static int vsock_connectible_getsockopt(struct socket *sock,
1669                                         int level, int optname,
1670                                         char __user *optval,
1671                                         int __user *optlen)
1672 {
1673         struct sock *sk = sock->sk;
1674         struct vsock_sock *vsk = vsock_sk(sk);
1675
1676         union {
1677                 u64 val64;
1678                 struct old_timeval32 tm32;
1679                 struct __kernel_old_timeval tm;
1680                 struct  __kernel_sock_timeval stm;
1681         } v;
1682
1683         int lv = sizeof(v.val64);
1684         int len;
1685
1686         if (level != AF_VSOCK)
1687                 return -ENOPROTOOPT;
1688
1689         if (get_user(len, optlen))
1690                 return -EFAULT;
1691
1692         memset(&v, 0, sizeof(v));
1693
1694         switch (optname) {
1695         case SO_VM_SOCKETS_BUFFER_SIZE:
1696                 v.val64 = vsk->buffer_size;
1697                 break;
1698
1699         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1700                 v.val64 = vsk->buffer_max_size;
1701                 break;
1702
1703         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1704                 v.val64 = vsk->buffer_min_size;
1705                 break;
1706
1707         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1708         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1709                 lv = sock_get_timeout(vsk->connect_timeout, &v,
1710                                       optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1711                 break;
1712
1713         default:
1714                 return -ENOPROTOOPT;
1715         }
1716
1717         if (len < lv)
1718                 return -EINVAL;
1719         if (len > lv)
1720                 len = lv;
1721         if (copy_to_user(optval, &v, len))
1722                 return -EFAULT;
1723
1724         if (put_user(len, optlen))
1725                 return -EFAULT;
1726
1727         return 0;
1728 }
1729
1730 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1731                                      size_t len)
1732 {
1733         struct sock *sk;
1734         struct vsock_sock *vsk;
1735         const struct vsock_transport *transport;
1736         ssize_t total_written;
1737         long timeout;
1738         int err;
1739         struct vsock_transport_send_notify_data send_data;
1740         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1741
1742         sk = sock->sk;
1743         vsk = vsock_sk(sk);
1744         total_written = 0;
1745         err = 0;
1746
1747         if (msg->msg_flags & MSG_OOB)
1748                 return -EOPNOTSUPP;
1749
1750         lock_sock(sk);
1751
1752         transport = vsk->transport;
1753
1754         /* Callers should not provide a destination with connection oriented
1755          * sockets.
1756          */
1757         if (msg->msg_namelen) {
1758                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1759                 goto out;
1760         }
1761
1762         /* Send data only if both sides are not shutdown in the direction. */
1763         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1764             vsk->peer_shutdown & RCV_SHUTDOWN) {
1765                 err = -EPIPE;
1766                 goto out;
1767         }
1768
1769         if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1770             !vsock_addr_bound(&vsk->local_addr)) {
1771                 err = -ENOTCONN;
1772                 goto out;
1773         }
1774
1775         if (!vsock_addr_bound(&vsk->remote_addr)) {
1776                 err = -EDESTADDRREQ;
1777                 goto out;
1778         }
1779
1780         /* Wait for room in the produce queue to enqueue our user's data. */
1781         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1782
1783         err = transport->notify_send_init(vsk, &send_data);
1784         if (err < 0)
1785                 goto out;
1786
1787         while (total_written < len) {
1788                 ssize_t written;
1789
1790                 add_wait_queue(sk_sleep(sk), &wait);
1791                 while (vsock_stream_has_space(vsk) == 0 &&
1792                        sk->sk_err == 0 &&
1793                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1794                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1795
1796                         /* Don't wait for non-blocking sockets. */
1797                         if (timeout == 0) {
1798                                 err = -EAGAIN;
1799                                 remove_wait_queue(sk_sleep(sk), &wait);
1800                                 goto out_err;
1801                         }
1802
1803                         err = transport->notify_send_pre_block(vsk, &send_data);
1804                         if (err < 0) {
1805                                 remove_wait_queue(sk_sleep(sk), &wait);
1806                                 goto out_err;
1807                         }
1808
1809                         release_sock(sk);
1810                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1811                         lock_sock(sk);
1812                         if (signal_pending(current)) {
1813                                 err = sock_intr_errno(timeout);
1814                                 remove_wait_queue(sk_sleep(sk), &wait);
1815                                 goto out_err;
1816                         } else if (timeout == 0) {
1817                                 err = -EAGAIN;
1818                                 remove_wait_queue(sk_sleep(sk), &wait);
1819                                 goto out_err;
1820                         }
1821                 }
1822                 remove_wait_queue(sk_sleep(sk), &wait);
1823
1824                 /* These checks occur both as part of and after the loop
1825                  * conditional since we need to check before and after
1826                  * sleeping.
1827                  */
1828                 if (sk->sk_err) {
1829                         err = -sk->sk_err;
1830                         goto out_err;
1831                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1832                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1833                         err = -EPIPE;
1834                         goto out_err;
1835                 }
1836
1837                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1838                 if (err < 0)
1839                         goto out_err;
1840
1841                 /* Note that enqueue will only write as many bytes as are free
1842                  * in the produce queue, so we don't need to ensure len is
1843                  * smaller than the queue size.  It is the caller's
1844                  * responsibility to check how many bytes we were able to send.
1845                  */
1846
1847                 if (sk->sk_type == SOCK_SEQPACKET) {
1848                         written = transport->seqpacket_enqueue(vsk,
1849                                                 msg, len - total_written);
1850                 } else {
1851                         written = transport->stream_enqueue(vsk,
1852                                         msg, len - total_written);
1853                 }
1854                 if (written < 0) {
1855                         err = -ENOMEM;
1856                         goto out_err;
1857                 }
1858
1859                 total_written += written;
1860
1861                 err = transport->notify_send_post_enqueue(
1862                                 vsk, written, &send_data);
1863                 if (err < 0)
1864                         goto out_err;
1865
1866         }
1867
1868 out_err:
1869         if (total_written > 0) {
1870                 /* Return number of written bytes only if:
1871                  * 1) SOCK_STREAM socket.
1872                  * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1873                  */
1874                 if (sk->sk_type == SOCK_STREAM || total_written == len)
1875                         err = total_written;
1876         }
1877 out:
1878         release_sock(sk);
1879         return err;
1880 }
1881
1882 static int vsock_connectible_wait_data(struct sock *sk,
1883                                        struct wait_queue_entry *wait,
1884                                        long timeout,
1885                                        struct vsock_transport_recv_notify_data *recv_data,
1886                                        size_t target)
1887 {
1888         const struct vsock_transport *transport;
1889         struct vsock_sock *vsk;
1890         s64 data;
1891         int err;
1892
1893         vsk = vsock_sk(sk);
1894         err = 0;
1895         transport = vsk->transport;
1896
1897         while ((data = vsock_connectible_has_data(vsk)) == 0) {
1898                 prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1899
1900                 if (sk->sk_err != 0 ||
1901                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1902                     (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1903                         break;
1904                 }
1905
1906                 /* Don't wait for non-blocking sockets. */
1907                 if (timeout == 0) {
1908                         err = -EAGAIN;
1909                         break;
1910                 }
1911
1912                 if (recv_data) {
1913                         err = transport->notify_recv_pre_block(vsk, target, recv_data);
1914                         if (err < 0)
1915                                 break;
1916                 }
1917
1918                 release_sock(sk);
1919                 timeout = schedule_timeout(timeout);
1920                 lock_sock(sk);
1921
1922                 if (signal_pending(current)) {
1923                         err = sock_intr_errno(timeout);
1924                         break;
1925                 } else if (timeout == 0) {
1926                         err = -EAGAIN;
1927                         break;
1928                 }
1929         }
1930
1931         finish_wait(sk_sleep(sk), wait);
1932
1933         if (err)
1934                 return err;
1935
1936         /* Internal transport error when checking for available
1937          * data. XXX This should be changed to a connection
1938          * reset in a later change.
1939          */
1940         if (data < 0)
1941                 return -ENOMEM;
1942
1943         return data;
1944 }
1945
1946 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1947                                   size_t len, int flags)
1948 {
1949         struct vsock_transport_recv_notify_data recv_data;
1950         const struct vsock_transport *transport;
1951         struct vsock_sock *vsk;
1952         ssize_t copied;
1953         size_t target;
1954         long timeout;
1955         int err;
1956
1957         DEFINE_WAIT(wait);
1958
1959         vsk = vsock_sk(sk);
1960         transport = vsk->transport;
1961
1962         /* We must not copy less than target bytes into the user's buffer
1963          * before returning successfully, so we wait for the consume queue to
1964          * have that much data to consume before dequeueing.  Note that this
1965          * makes it impossible to handle cases where target is greater than the
1966          * queue size.
1967          */
1968         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1969         if (target >= transport->stream_rcvhiwat(vsk)) {
1970                 err = -ENOMEM;
1971                 goto out;
1972         }
1973         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1974         copied = 0;
1975
1976         err = transport->notify_recv_init(vsk, target, &recv_data);
1977         if (err < 0)
1978                 goto out;
1979
1980
1981         while (1) {
1982                 ssize_t read;
1983
1984                 err = vsock_connectible_wait_data(sk, &wait, timeout,
1985                                                   &recv_data, target);
1986                 if (err <= 0)
1987                         break;
1988
1989                 err = transport->notify_recv_pre_dequeue(vsk, target,
1990                                                          &recv_data);
1991                 if (err < 0)
1992                         break;
1993
1994                 read = transport->stream_dequeue(vsk, msg, len - copied, flags);
1995                 if (read < 0) {
1996                         err = -ENOMEM;
1997                         break;
1998                 }
1999
2000                 copied += read;
2001
2002                 err = transport->notify_recv_post_dequeue(vsk, target, read,
2003                                                 !(flags & MSG_PEEK), &recv_data);
2004                 if (err < 0)
2005                         goto out;
2006
2007                 if (read >= target || flags & MSG_PEEK)
2008                         break;
2009
2010                 target -= read;
2011         }
2012
2013         if (sk->sk_err)
2014                 err = -sk->sk_err;
2015         else if (sk->sk_shutdown & RCV_SHUTDOWN)
2016                 err = 0;
2017
2018         if (copied > 0)
2019                 err = copied;
2020
2021 out:
2022         return err;
2023 }
2024
2025 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2026                                      size_t len, int flags)
2027 {
2028         const struct vsock_transport *transport;
2029         struct vsock_sock *vsk;
2030         ssize_t msg_len;
2031         long timeout;
2032         int err = 0;
2033         DEFINE_WAIT(wait);
2034
2035         vsk = vsock_sk(sk);
2036         transport = vsk->transport;
2037
2038         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2039
2040         err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2041         if (err <= 0)
2042                 goto out;
2043
2044         msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2045
2046         if (msg_len < 0) {
2047                 err = -ENOMEM;
2048                 goto out;
2049         }
2050
2051         if (sk->sk_err) {
2052                 err = -sk->sk_err;
2053         } else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2054                 err = 0;
2055         } else {
2056                 /* User sets MSG_TRUNC, so return real length of
2057                  * packet.
2058                  */
2059                 if (flags & MSG_TRUNC)
2060                         err = msg_len;
2061                 else
2062                         err = len - msg_data_left(msg);
2063
2064                 /* Always set MSG_TRUNC if real length of packet is
2065                  * bigger than user's buffer.
2066                  */
2067                 if (msg_len > len)
2068                         msg->msg_flags |= MSG_TRUNC;
2069         }
2070
2071 out:
2072         return err;
2073 }
2074
2075 static int
2076 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2077                           int flags)
2078 {
2079         struct sock *sk;
2080         struct vsock_sock *vsk;
2081         const struct vsock_transport *transport;
2082         int err;
2083
2084         DEFINE_WAIT(wait);
2085
2086         sk = sock->sk;
2087         vsk = vsock_sk(sk);
2088         err = 0;
2089
2090         lock_sock(sk);
2091
2092         transport = vsk->transport;
2093
2094         if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2095                 /* Recvmsg is supposed to return 0 if a peer performs an
2096                  * orderly shutdown. Differentiate between that case and when a
2097                  * peer has not connected or a local shutdown occurred with the
2098                  * SOCK_DONE flag.
2099                  */
2100                 if (sock_flag(sk, SOCK_DONE))
2101                         err = 0;
2102                 else
2103                         err = -ENOTCONN;
2104
2105                 goto out;
2106         }
2107
2108         if (flags & MSG_OOB) {
2109                 err = -EOPNOTSUPP;
2110                 goto out;
2111         }
2112
2113         /* We don't check peer_shutdown flag here since peer may actually shut
2114          * down, but there can be data in the queue that a local socket can
2115          * receive.
2116          */
2117         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2118                 err = 0;
2119                 goto out;
2120         }
2121
2122         /* It is valid on Linux to pass in a zero-length receive buffer.  This
2123          * is not an error.  We may as well bail out now.
2124          */
2125         if (!len) {
2126                 err = 0;
2127                 goto out;
2128         }
2129
2130         if (sk->sk_type == SOCK_STREAM)
2131                 err = __vsock_stream_recvmsg(sk, msg, len, flags);
2132         else
2133                 err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2134
2135 out:
2136         release_sock(sk);
2137         return err;
2138 }
2139
2140 static const struct proto_ops vsock_stream_ops = {
2141         .family = PF_VSOCK,
2142         .owner = THIS_MODULE,
2143         .release = vsock_release,
2144         .bind = vsock_bind,
2145         .connect = vsock_connect,
2146         .socketpair = sock_no_socketpair,
2147         .accept = vsock_accept,
2148         .getname = vsock_getname,
2149         .poll = vsock_poll,
2150         .ioctl = sock_no_ioctl,
2151         .listen = vsock_listen,
2152         .shutdown = vsock_shutdown,
2153         .setsockopt = vsock_connectible_setsockopt,
2154         .getsockopt = vsock_connectible_getsockopt,
2155         .sendmsg = vsock_connectible_sendmsg,
2156         .recvmsg = vsock_connectible_recvmsg,
2157         .mmap = sock_no_mmap,
2158         .sendpage = sock_no_sendpage,
2159 };
2160
2161 static const struct proto_ops vsock_seqpacket_ops = {
2162         .family = PF_VSOCK,
2163         .owner = THIS_MODULE,
2164         .release = vsock_release,
2165         .bind = vsock_bind,
2166         .connect = vsock_connect,
2167         .socketpair = sock_no_socketpair,
2168         .accept = vsock_accept,
2169         .getname = vsock_getname,
2170         .poll = vsock_poll,
2171         .ioctl = sock_no_ioctl,
2172         .listen = vsock_listen,
2173         .shutdown = vsock_shutdown,
2174         .setsockopt = vsock_connectible_setsockopt,
2175         .getsockopt = vsock_connectible_getsockopt,
2176         .sendmsg = vsock_connectible_sendmsg,
2177         .recvmsg = vsock_connectible_recvmsg,
2178         .mmap = sock_no_mmap,
2179         .sendpage = sock_no_sendpage,
2180 };
2181
2182 static int vsock_create(struct net *net, struct socket *sock,
2183                         int protocol, int kern)
2184 {
2185         struct vsock_sock *vsk;
2186         struct sock *sk;
2187         int ret;
2188
2189         if (!sock)
2190                 return -EINVAL;
2191
2192         if (protocol && protocol != PF_VSOCK)
2193                 return -EPROTONOSUPPORT;
2194
2195         switch (sock->type) {
2196         case SOCK_DGRAM:
2197                 sock->ops = &vsock_dgram_ops;
2198                 break;
2199         case SOCK_STREAM:
2200                 sock->ops = &vsock_stream_ops;
2201                 break;
2202         case SOCK_SEQPACKET:
2203                 sock->ops = &vsock_seqpacket_ops;
2204                 break;
2205         default:
2206                 return -ESOCKTNOSUPPORT;
2207         }
2208
2209         sock->state = SS_UNCONNECTED;
2210
2211         sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2212         if (!sk)
2213                 return -ENOMEM;
2214
2215         vsk = vsock_sk(sk);
2216
2217         if (sock->type == SOCK_DGRAM) {
2218                 ret = vsock_assign_transport(vsk, NULL);
2219                 if (ret < 0) {
2220                         sock_put(sk);
2221                         return ret;
2222                 }
2223         }
2224
2225         vsock_insert_unbound(vsk);
2226
2227         return 0;
2228 }
2229
2230 static const struct net_proto_family vsock_family_ops = {
2231         .family = AF_VSOCK,
2232         .create = vsock_create,
2233         .owner = THIS_MODULE,
2234 };
2235
2236 static long vsock_dev_do_ioctl(struct file *filp,
2237                                unsigned int cmd, void __user *ptr)
2238 {
2239         u32 __user *p = ptr;
2240         u32 cid = VMADDR_CID_ANY;
2241         int retval = 0;
2242
2243         switch (cmd) {
2244         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2245                 /* To be compatible with the VMCI behavior, we prioritize the
2246                  * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2247                  */
2248                 if (transport_g2h)
2249                         cid = transport_g2h->get_local_cid();
2250                 else if (transport_h2g)
2251                         cid = transport_h2g->get_local_cid();
2252
2253                 if (put_user(cid, p) != 0)
2254                         retval = -EFAULT;
2255                 break;
2256
2257         default:
2258                 retval = -ENOIOCTLCMD;
2259         }
2260
2261         return retval;
2262 }
2263
2264 static long vsock_dev_ioctl(struct file *filp,
2265                             unsigned int cmd, unsigned long arg)
2266 {
2267         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2268 }
2269
2270 #ifdef CONFIG_COMPAT
2271 static long vsock_dev_compat_ioctl(struct file *filp,
2272                                    unsigned int cmd, unsigned long arg)
2273 {
2274         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2275 }
2276 #endif
2277
2278 static const struct file_operations vsock_device_ops = {
2279         .owner          = THIS_MODULE,
2280         .unlocked_ioctl = vsock_dev_ioctl,
2281 #ifdef CONFIG_COMPAT
2282         .compat_ioctl   = vsock_dev_compat_ioctl,
2283 #endif
2284         .open           = nonseekable_open,
2285 };
2286
2287 static struct miscdevice vsock_device = {
2288         .name           = "vsock",
2289         .fops           = &vsock_device_ops,
2290 };
2291
2292 static int __init vsock_init(void)
2293 {
2294         int err = 0;
2295
2296         vsock_init_tables();
2297
2298         vsock_proto.owner = THIS_MODULE;
2299         vsock_device.minor = MISC_DYNAMIC_MINOR;
2300         err = misc_register(&vsock_device);
2301         if (err) {
2302                 pr_err("Failed to register misc device\n");
2303                 goto err_reset_transport;
2304         }
2305
2306         err = proto_register(&vsock_proto, 1);  /* we want our slab */
2307         if (err) {
2308                 pr_err("Cannot register vsock protocol\n");
2309                 goto err_deregister_misc;
2310         }
2311
2312         err = sock_register(&vsock_family_ops);
2313         if (err) {
2314                 pr_err("could not register af_vsock (%d) address family: %d\n",
2315                        AF_VSOCK, err);
2316                 goto err_unregister_proto;
2317         }
2318
2319         return 0;
2320
2321 err_unregister_proto:
2322         proto_unregister(&vsock_proto);
2323 err_deregister_misc:
2324         misc_deregister(&vsock_device);
2325 err_reset_transport:
2326         return err;
2327 }
2328
2329 static void __exit vsock_exit(void)
2330 {
2331         misc_deregister(&vsock_device);
2332         sock_unregister(AF_VSOCK);
2333         proto_unregister(&vsock_proto);
2334 }
2335
2336 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2337 {
2338         return vsk->transport;
2339 }
2340 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2341
2342 int vsock_core_register(const struct vsock_transport *t, int features)
2343 {
2344         const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2345         int err = mutex_lock_interruptible(&vsock_register_mutex);
2346
2347         if (err)
2348                 return err;
2349
2350         t_h2g = transport_h2g;
2351         t_g2h = transport_g2h;
2352         t_dgram = transport_dgram;
2353         t_local = transport_local;
2354
2355         if (features & VSOCK_TRANSPORT_F_H2G) {
2356                 if (t_h2g) {
2357                         err = -EBUSY;
2358                         goto err_busy;
2359                 }
2360                 t_h2g = t;
2361         }
2362
2363         if (features & VSOCK_TRANSPORT_F_G2H) {
2364                 if (t_g2h) {
2365                         err = -EBUSY;
2366                         goto err_busy;
2367                 }
2368                 t_g2h = t;
2369         }
2370
2371         if (features & VSOCK_TRANSPORT_F_DGRAM) {
2372                 if (t_dgram) {
2373                         err = -EBUSY;
2374                         goto err_busy;
2375                 }
2376                 t_dgram = t;
2377         }
2378
2379         if (features & VSOCK_TRANSPORT_F_LOCAL) {
2380                 if (t_local) {
2381                         err = -EBUSY;
2382                         goto err_busy;
2383                 }
2384                 t_local = t;
2385         }
2386
2387         transport_h2g = t_h2g;
2388         transport_g2h = t_g2h;
2389         transport_dgram = t_dgram;
2390         transport_local = t_local;
2391
2392 err_busy:
2393         mutex_unlock(&vsock_register_mutex);
2394         return err;
2395 }
2396 EXPORT_SYMBOL_GPL(vsock_core_register);
2397
2398 void vsock_core_unregister(const struct vsock_transport *t)
2399 {
2400         mutex_lock(&vsock_register_mutex);
2401
2402         if (transport_h2g == t)
2403                 transport_h2g = NULL;
2404
2405         if (transport_g2h == t)
2406                 transport_g2h = NULL;
2407
2408         if (transport_dgram == t)
2409                 transport_dgram = NULL;
2410
2411         if (transport_local == t)
2412                 transport_local = NULL;
2413
2414         mutex_unlock(&vsock_register_mutex);
2415 }
2416 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2417
2418 module_init(vsock_init);
2419 module_exit(vsock_exit);
2420
2421 MODULE_AUTHOR("VMware, Inc.");
2422 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2423 MODULE_VERSION("1.0.2.0-k");
2424 MODULE_LICENSE("GPL v2");