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 void vsock_data_ready(struct sock *sk)
 886 {
 887         struct vsock_sock *vsk = vsock_sk(sk);
 888
 889         if (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
 890             sock_flag(sk, SOCK_DONE))
 891                 sk->sk_data_ready(sk);
 892 }
 893 EXPORT_SYMBOL_GPL(vsock_data_ready);
 894
 895 static int vsock_release(struct socket *sock)
 896 {
 897         __vsock_release(sock->sk, 0);
 898         sock->sk = NULL;
 899         sock->state = SS_FREE;
 900
 901         return 0;
 902 }
 903
 904 static int
 905 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 906 {
 907         int err;
 908         struct sock *sk;
 909         struct sockaddr_vm *vm_addr;
 910
 911         sk = sock->sk;
 912
 913         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 914                 return -EINVAL;
 915
 916         lock_sock(sk);
 917         err = __vsock_bind(sk, vm_addr);
 918         release_sock(sk);
 919
 920         return err;
 921 }
 922
 923 static int vsock_getname(struct socket *sock,
 924                          struct sockaddr *addr, int peer)
 925 {
 926         int err;
 927         struct sock *sk;
 928         struct vsock_sock *vsk;
 929         struct sockaddr_vm *vm_addr;
 930
 931         sk = sock->sk;
 932         vsk = vsock_sk(sk);
 933         err = 0;
 934
 935         lock_sock(sk);
 936
 937         if (peer) {
 938                 if (sock->state != SS_CONNECTED) {
 939                         err = -ENOTCONN;
 940                         goto out;
 941                 }
 942                 vm_addr = &vsk->remote_addr;
 943         } else {
 944                 vm_addr = &vsk->local_addr;
 945         }
 946
 947         if (!vm_addr) {
 948                 err = -EINVAL;
 949                 goto out;
 950         }
 951
 952         /* sys_getsockname() and sys_getpeername() pass us a
 953          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 954          * that macro is defined in socket.c instead of .h, so we hardcode its
 955          * value here.
 956          */
 957         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 958         memcpy(addr, vm_addr, sizeof(*vm_addr));
 959         err = sizeof(*vm_addr);
 960
 961 out:
 962         release_sock(sk);
 963         return err;
 964 }
 965
 966 static int vsock_shutdown(struct socket *sock, int mode)
 967 {
 968         int err;
 969         struct sock *sk;
 970
 971         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 972          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 973          * here like the other address families do.  Note also that the
 974          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 975          * which is what we want.
 976          */
 977         mode++;
 978
 979         if ((mode & ~SHUTDOWN_MASK) || !mode)
 980                 return -EINVAL;
 981
 982         /* If this is a connection oriented socket and it is not connected then
 983          * bail out immediately.  If it is a DGRAM socket then we must first
 984          * kick the socket so that it wakes up from any sleeping calls, for
 985          * example recv(), and then afterwards return the error.
 986          */
 987
 988         sk = sock->sk;
 989
 990         lock_sock(sk);
 991         if (sock->state == SS_UNCONNECTED) {
 992                 err = -ENOTCONN;
 993                 if (sock_type_connectible(sk->sk_type))
 994                         goto out;
 995         } else {
 996                 sock->state = SS_DISCONNECTING;
 997                 err = 0;
 998         }
 999
1000         /* Receive and send shutdowns are treated alike. */
1001         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
1002         if (mode) {
1003                 sk->sk_shutdown |= mode;
1004                 sk->sk_state_change(sk);
1005
1006                 if (sock_type_connectible(sk->sk_type)) {
1007                         sock_reset_flag(sk, SOCK_DONE);
1008                         vsock_send_shutdown(sk, mode);
1009                 }
1010         }
1011
1012 out:
1013         release_sock(sk);
1014         return err;
1015 }
1016
1017 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1018                                poll_table *wait)
1019 {
1020         struct sock *sk;
1021         __poll_t mask;
1022         struct vsock_sock *vsk;
1023
1024         sk = sock->sk;
1025         vsk = vsock_sk(sk);
1026
1027         poll_wait(file, sk_sleep(sk), wait);
1028         mask = 0;
1029
1030         if (sk->sk_err)
1031                 /* Signify that there has been an error on this socket. */
1032                 mask |= EPOLLERR;
1033
1034         /* INET sockets treat local write shutdown and peer write shutdown as a
1035          * case of EPOLLHUP set.
1036          */
1037         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1038             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1039              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1040                 mask |= EPOLLHUP;
1041         }
1042
1043         if (sk->sk_shutdown & RCV_SHUTDOWN ||
1044             vsk->peer_shutdown & SEND_SHUTDOWN) {
1045                 mask |= EPOLLRDHUP;
1046         }
1047
1048         if (sock->type == SOCK_DGRAM) {
1049                 /* For datagram sockets we can read if there is something in
1050                  * the queue and write as long as the socket isn't shutdown for
1051                  * sending.
1052                  */
1053                 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1054                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
1055                         mask |= EPOLLIN | EPOLLRDNORM;
1056                 }
1057
1058                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1059                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1060
1061         } else if (sock_type_connectible(sk->sk_type)) {
1062                 const struct vsock_transport *transport;
1063
1064                 lock_sock(sk);
1065
1066                 transport = vsk->transport;
1067
1068                 /* Listening sockets that have connections in their accept
1069                  * queue can be read.
1070                  */
1071                 if (sk->sk_state == TCP_LISTEN
1072                     && !vsock_is_accept_queue_empty(sk))
1073                         mask |= EPOLLIN | EPOLLRDNORM;
1074
1075                 /* If there is something in the queue then we can read. */
1076                 if (transport && transport->stream_is_active(vsk) &&
1077                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1078                         bool data_ready_now = false;
1079                         int target = sock_rcvlowat(sk, 0, INT_MAX);
1080                         int ret = transport->notify_poll_in(
1081                                         vsk, target, &data_ready_now);
1082                         if (ret < 0) {
1083                                 mask |= EPOLLERR;
1084                         } else {
1085                                 if (data_ready_now)
1086                                         mask |= EPOLLIN | EPOLLRDNORM;
1087
1088                         }
1089                 }
1090
1091                 /* Sockets whose connections have been closed, reset, or
1092                  * terminated should also be considered read, and we check the
1093                  * shutdown flag for that.
1094                  */
1095                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
1096                     vsk->peer_shutdown & SEND_SHUTDOWN) {
1097                         mask |= EPOLLIN | EPOLLRDNORM;
1098                 }
1099
1100                 /* Connected sockets that can produce data can be written. */
1101                 if (transport && sk->sk_state == TCP_ESTABLISHED) {
1102                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1103                                 bool space_avail_now = false;
1104                                 int ret = transport->notify_poll_out(
1105                                                 vsk, 1, &space_avail_now);
1106                                 if (ret < 0) {
1107                                         mask |= EPOLLERR;
1108                                 } else {
1109                                         if (space_avail_now)
1110                                                 /* Remove EPOLLWRBAND since INET
1111                                                  * sockets are not setting it.
1112                                                  */
1113                                                 mask |= EPOLLOUT | EPOLLWRNORM;
1114
1115                                 }
1116                         }
1117                 }
1118
1119                 /* Simulate INET socket poll behaviors, which sets
1120                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1121                  * but local send is not shutdown.
1122                  */
1123                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1124                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1125                                 mask |= EPOLLOUT | EPOLLWRNORM;
1126
1127                 }
1128
1129                 release_sock(sk);
1130         }
1131
1132         return mask;
1133 }
1134
1135 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1136                                size_t len)
1137 {
1138         int err;
1139         struct sock *sk;
1140         struct vsock_sock *vsk;
1141         struct sockaddr_vm *remote_addr;
1142         const struct vsock_transport *transport;
1143
1144         if (msg->msg_flags & MSG_OOB)
1145                 return -EOPNOTSUPP;
1146
1147         /* For now, MSG_DONTWAIT is always assumed... */
1148         err = 0;
1149         sk = sock->sk;
1150         vsk = vsock_sk(sk);
1151
1152         lock_sock(sk);
1153
1154         transport = vsk->transport;
1155
1156         err = vsock_auto_bind(vsk);
1157         if (err)
1158                 goto out;
1159
1160
1161         /* If the provided message contains an address, use that.  Otherwise
1162          * fall back on the socket's remote handle (if it has been connected).
1163          */
1164         if (msg->msg_name &&
1165             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1166                             &remote_addr) == 0) {
1167                 /* Ensure this address is of the right type and is a valid
1168                  * destination.
1169                  */
1170
1171                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1172                         remote_addr->svm_cid = transport->get_local_cid();
1173
1174                 if (!vsock_addr_bound(remote_addr)) {
1175                         err = -EINVAL;
1176                         goto out;
1177                 }
1178         } else if (sock->state == SS_CONNECTED) {
1179                 remote_addr = &vsk->remote_addr;
1180
1181                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1182                         remote_addr->svm_cid = transport->get_local_cid();
1183
1184                 /* XXX Should connect() or this function ensure remote_addr is
1185                  * bound?
1186                  */
1187                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1188                         err = -EINVAL;
1189                         goto out;
1190                 }
1191         } else {
1192                 err = -EINVAL;
1193                 goto out;
1194         }
1195
1196         if (!transport->dgram_allow(remote_addr->svm_cid,
1197                                     remote_addr->svm_port)) {
1198                 err = -EINVAL;
1199                 goto out;
1200         }
1201
1202         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1203
1204 out:
1205         release_sock(sk);
1206         return err;
1207 }
1208
1209 static int vsock_dgram_connect(struct socket *sock,
1210                                struct sockaddr *addr, int addr_len, int flags)
1211 {
1212         int err;
1213         struct sock *sk;
1214         struct vsock_sock *vsk;
1215         struct sockaddr_vm *remote_addr;
1216
1217         sk = sock->sk;
1218         vsk = vsock_sk(sk);
1219
1220         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1221         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1222                 lock_sock(sk);
1223                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1224                                 VMADDR_PORT_ANY);
1225                 sock->state = SS_UNCONNECTED;
1226                 release_sock(sk);
1227                 return 0;
1228         } else if (err != 0)
1229                 return -EINVAL;
1230
1231         lock_sock(sk);
1232
1233         err = vsock_auto_bind(vsk);
1234         if (err)
1235                 goto out;
1236
1237         if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1238                                          remote_addr->svm_port)) {
1239                 err = -EINVAL;
1240                 goto out;
1241         }
1242
1243         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1244         sock->state = SS_CONNECTED;
1245
1246 out:
1247         release_sock(sk);
1248         return err;
1249 }
1250
1251 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1252                                size_t len, int flags)
1253 {
1254         struct vsock_sock *vsk = vsock_sk(sock->sk);
1255
1256         return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1257 }
1258
1259 static const struct proto_ops vsock_dgram_ops = {
1260         .family = PF_VSOCK,
1261         .owner = THIS_MODULE,
1262         .release = vsock_release,
1263         .bind = vsock_bind,
1264         .connect = vsock_dgram_connect,
1265         .socketpair = sock_no_socketpair,
1266         .accept = sock_no_accept,
1267         .getname = vsock_getname,
1268         .poll = vsock_poll,
1269         .ioctl = sock_no_ioctl,
1270         .listen = sock_no_listen,
1271         .shutdown = vsock_shutdown,
1272         .sendmsg = vsock_dgram_sendmsg,
1273         .recvmsg = vsock_dgram_recvmsg,
1274         .mmap = sock_no_mmap,
1275         .sendpage = sock_no_sendpage,
1276 };
1277
1278 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1279 {
1280         const struct vsock_transport *transport = vsk->transport;
1281
1282         if (!transport || !transport->cancel_pkt)
1283                 return -EOPNOTSUPP;
1284
1285         return transport->cancel_pkt(vsk);
1286 }
1287
1288 static void vsock_connect_timeout(struct work_struct *work)
1289 {
1290         struct sock *sk;
1291         struct vsock_sock *vsk;
1292
1293         vsk = container_of(work, struct vsock_sock, connect_work.work);
1294         sk = sk_vsock(vsk);
1295
1296         lock_sock(sk);
1297         if (sk->sk_state == TCP_SYN_SENT &&
1298             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1299                 sk->sk_state = TCP_CLOSE;
1300                 sk->sk_socket->state = SS_UNCONNECTED;
1301                 sk->sk_err = ETIMEDOUT;
1302                 sk_error_report(sk);
1303                 vsock_transport_cancel_pkt(vsk);
1304         }
1305         release_sock(sk);
1306
1307         sock_put(sk);
1308 }
1309
1310 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1311                          int addr_len, int flags)
1312 {
1313         int err;
1314         struct sock *sk;
1315         struct vsock_sock *vsk;
1316         const struct vsock_transport *transport;
1317         struct sockaddr_vm *remote_addr;
1318         long timeout;
1319         DEFINE_WAIT(wait);
1320
1321         err = 0;
1322         sk = sock->sk;
1323         vsk = vsock_sk(sk);
1324
1325         lock_sock(sk);
1326
1327         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1328         switch (sock->state) {
1329         case SS_CONNECTED:
1330                 err = -EISCONN;
1331                 goto out;
1332         case SS_DISCONNECTING:
1333                 err = -EINVAL;
1334                 goto out;
1335         case SS_CONNECTING:
1336                 /* This continues on so we can move sock into the SS_CONNECTED
1337                  * state once the connection has completed (at which point err
1338                  * will be set to zero also).  Otherwise, we will either wait
1339                  * for the connection or return -EALREADY should this be a
1340                  * non-blocking call.
1341                  */
1342                 err = -EALREADY;
1343                 if (flags & O_NONBLOCK)
1344                         goto out;
1345                 break;
1346         default:
1347                 if ((sk->sk_state == TCP_LISTEN) ||
1348                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1349                         err = -EINVAL;
1350                         goto out;
1351                 }
1352
1353                 /* Set the remote address that we are connecting to. */
1354                 memcpy(&vsk->remote_addr, remote_addr,
1355                        sizeof(vsk->remote_addr));
1356
1357                 err = vsock_assign_transport(vsk, NULL);
1358                 if (err)
1359                         goto out;
1360
1361                 transport = vsk->transport;
1362
1363                 /* The hypervisor and well-known contexts do not have socket
1364                  * endpoints.
1365                  */
1366                 if (!transport ||
1367                     !transport->stream_allow(remote_addr->svm_cid,
1368                                              remote_addr->svm_port)) {
1369                         err = -ENETUNREACH;
1370                         goto out;
1371                 }
1372
1373                 err = vsock_auto_bind(vsk);
1374                 if (err)
1375                         goto out;
1376
1377                 sk->sk_state = TCP_SYN_SENT;
1378
1379                 err = transport->connect(vsk);
1380                 if (err < 0)
1381                         goto out;
1382
1383                 /* Mark sock as connecting and set the error code to in
1384                  * progress in case this is a non-blocking connect.
1385                  */
1386                 sock->state = SS_CONNECTING;
1387                 err = -EINPROGRESS;
1388         }
1389
1390         /* The receive path will handle all communication until we are able to
1391          * enter the connected state.  Here we wait for the connection to be
1392          * completed or a notification of an error.
1393          */
1394         timeout = vsk->connect_timeout;
1395         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1396
1397         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1398                 if (flags & O_NONBLOCK) {
1399                         /* If we're not going to block, we schedule a timeout
1400                          * function to generate a timeout on the connection
1401                          * attempt, in case the peer doesn't respond in a
1402                          * timely manner. We hold on to the socket until the
1403                          * timeout fires.
1404                          */
1405                         sock_hold(sk);
1406
1407                         /* If the timeout function is already scheduled,
1408                          * reschedule it, then ungrab the socket refcount to
1409                          * keep it balanced.
1410                          */
1411                         if (mod_delayed_work(system_wq, &vsk->connect_work,
1412                                              timeout))
1413                                 sock_put(sk);
1414
1415                         /* Skip ahead to preserve error code set above. */
1416                         goto out_wait;
1417                 }
1418
1419                 release_sock(sk);
1420                 timeout = schedule_timeout(timeout);
1421                 lock_sock(sk);
1422
1423                 if (signal_pending(current)) {
1424                         err = sock_intr_errno(timeout);
1425                         sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1426                         sock->state = SS_UNCONNECTED;
1427                         vsock_transport_cancel_pkt(vsk);
1428                         vsock_remove_connected(vsk);
1429                         goto out_wait;
1430                 } else if ((sk->sk_state != TCP_ESTABLISHED) && (timeout == 0)) {
1431                         err = -ETIMEDOUT;
1432                         sk->sk_state = TCP_CLOSE;
1433                         sock->state = SS_UNCONNECTED;
1434                         vsock_transport_cancel_pkt(vsk);
1435                         goto out_wait;
1436                 }
1437
1438                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1439         }
1440
1441         if (sk->sk_err) {
1442                 err = -sk->sk_err;
1443                 sk->sk_state = TCP_CLOSE;
1444                 sock->state = SS_UNCONNECTED;
1445         } else {
1446                 err = 0;
1447         }
1448
1449 out_wait:
1450         finish_wait(sk_sleep(sk), &wait);
1451 out:
1452         release_sock(sk);
1453         return err;
1454 }
1455
1456 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1457                         bool kern)
1458 {
1459         struct sock *listener;
1460         int err;
1461         struct sock *connected;
1462         struct vsock_sock *vconnected;
1463         long timeout;
1464         DEFINE_WAIT(wait);
1465
1466         err = 0;
1467         listener = sock->sk;
1468
1469         lock_sock(listener);
1470
1471         if (!sock_type_connectible(sock->type)) {
1472                 err = -EOPNOTSUPP;
1473                 goto out;
1474         }
1475
1476         if (listener->sk_state != TCP_LISTEN) {
1477                 err = -EINVAL;
1478                 goto out;
1479         }
1480
1481         /* Wait for children sockets to appear; these are the new sockets
1482          * created upon connection establishment.
1483          */
1484         timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1485         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1486
1487         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1488                listener->sk_err == 0) {
1489                 release_sock(listener);
1490                 timeout = schedule_timeout(timeout);
1491                 finish_wait(sk_sleep(listener), &wait);
1492                 lock_sock(listener);
1493
1494                 if (signal_pending(current)) {
1495                         err = sock_intr_errno(timeout);
1496                         goto out;
1497                 } else if (timeout == 0) {
1498                         err = -EAGAIN;
1499                         goto out;
1500                 }
1501
1502                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1503         }
1504         finish_wait(sk_sleep(listener), &wait);
1505
1506         if (listener->sk_err)
1507                 err = -listener->sk_err;
1508
1509         if (connected) {
1510                 sk_acceptq_removed(listener);
1511
1512                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1513                 vconnected = vsock_sk(connected);
1514
1515                 /* If the listener socket has received an error, then we should
1516                  * reject this socket and return.  Note that we simply mark the
1517                  * socket rejected, drop our reference, and let the cleanup
1518                  * function handle the cleanup; the fact that we found it in
1519                  * the listener's accept queue guarantees that the cleanup
1520                  * function hasn't run yet.
1521                  */
1522                 if (err) {
1523                         vconnected->rejected = true;
1524                 } else {
1525                         newsock->state = SS_CONNECTED;
1526                         sock_graft(connected, newsock);
1527                 }
1528
1529                 release_sock(connected);
1530                 sock_put(connected);
1531         }
1532
1533 out:
1534         release_sock(listener);
1535         return err;
1536 }
1537
1538 static int vsock_listen(struct socket *sock, int backlog)
1539 {
1540         int err;
1541         struct sock *sk;
1542         struct vsock_sock *vsk;
1543
1544         sk = sock->sk;
1545
1546         lock_sock(sk);
1547
1548         if (!sock_type_connectible(sk->sk_type)) {
1549                 err = -EOPNOTSUPP;
1550                 goto out;
1551         }
1552
1553         if (sock->state != SS_UNCONNECTED) {
1554                 err = -EINVAL;
1555                 goto out;
1556         }
1557
1558         vsk = vsock_sk(sk);
1559
1560         if (!vsock_addr_bound(&vsk->local_addr)) {
1561                 err = -EINVAL;
1562                 goto out;
1563         }
1564
1565         sk->sk_max_ack_backlog = backlog;
1566         sk->sk_state = TCP_LISTEN;
1567
1568         err = 0;
1569
1570 out:
1571         release_sock(sk);
1572         return err;
1573 }
1574
1575 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1576                                      const struct vsock_transport *transport,
1577                                      u64 val)
1578 {
1579         if (val > vsk->buffer_max_size)
1580                 val = vsk->buffer_max_size;
1581
1582         if (val < vsk->buffer_min_size)
1583                 val = vsk->buffer_min_size;
1584
1585         if (val != vsk->buffer_size &&
1586             transport && transport->notify_buffer_size)
1587                 transport->notify_buffer_size(vsk, &val);
1588
1589         vsk->buffer_size = val;
1590 }
1591
1592 static int vsock_connectible_setsockopt(struct socket *sock,
1593                                         int level,
1594                                         int optname,
1595                                         sockptr_t optval,
1596                                         unsigned int optlen)
1597 {
1598         int err;
1599         struct sock *sk;
1600         struct vsock_sock *vsk;
1601         const struct vsock_transport *transport;
1602         u64 val;
1603
1604         if (level != AF_VSOCK)
1605                 return -ENOPROTOOPT;
1606
1607 #define COPY_IN(_v)                                       \
1608         do {                                              \
1609                 if (optlen < sizeof(_v)) {                \
1610                         err = -EINVAL;                    \
1611                         goto exit;                        \
1612                 }                                         \
1613                 if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {  \
1614                         err = -EFAULT;                                  \
1615                         goto exit;                                      \
1616                 }                                                       \
1617         } while (0)
1618
1619         err = 0;
1620         sk = sock->sk;
1621         vsk = vsock_sk(sk);
1622
1623         lock_sock(sk);
1624
1625         transport = vsk->transport;
1626
1627         switch (optname) {
1628         case SO_VM_SOCKETS_BUFFER_SIZE:
1629                 COPY_IN(val);
1630                 vsock_update_buffer_size(vsk, transport, val);
1631                 break;
1632
1633         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1634                 COPY_IN(val);
1635                 vsk->buffer_max_size = val;
1636                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1637                 break;
1638
1639         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1640                 COPY_IN(val);
1641                 vsk->buffer_min_size = val;
1642                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1643                 break;
1644
1645         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1646         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1647                 struct __kernel_sock_timeval tv;
1648
1649                 err = sock_copy_user_timeval(&tv, optval, optlen,
1650                                              optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1651                 if (err)
1652                         break;
1653                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1654                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1655                         vsk->connect_timeout = tv.tv_sec * HZ +
1656                                 DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1657                         if (vsk->connect_timeout == 0)
1658                                 vsk->connect_timeout =
1659                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1660
1661                 } else {
1662                         err = -ERANGE;
1663                 }
1664                 break;
1665         }
1666
1667         default:
1668                 err = -ENOPROTOOPT;
1669                 break;
1670         }
1671
1672 #undef COPY_IN
1673
1674 exit:
1675         release_sock(sk);
1676         return err;
1677 }
1678
1679 static int vsock_connectible_getsockopt(struct socket *sock,
1680                                         int level, int optname,
1681                                         char __user *optval,
1682                                         int __user *optlen)
1683 {
1684         struct sock *sk = sock->sk;
1685         struct vsock_sock *vsk = vsock_sk(sk);
1686
1687         union {
1688                 u64 val64;
1689                 struct old_timeval32 tm32;
1690                 struct __kernel_old_timeval tm;
1691                 struct  __kernel_sock_timeval stm;
1692         } v;
1693
1694         int lv = sizeof(v.val64);
1695         int len;
1696
1697         if (level != AF_VSOCK)
1698                 return -ENOPROTOOPT;
1699
1700         if (get_user(len, optlen))
1701                 return -EFAULT;
1702
1703         memset(&v, 0, sizeof(v));
1704
1705         switch (optname) {
1706         case SO_VM_SOCKETS_BUFFER_SIZE:
1707                 v.val64 = vsk->buffer_size;
1708                 break;
1709
1710         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1711                 v.val64 = vsk->buffer_max_size;
1712                 break;
1713
1714         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1715                 v.val64 = vsk->buffer_min_size;
1716                 break;
1717
1718         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1719         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1720                 lv = sock_get_timeout(vsk->connect_timeout, &v,
1721                                       optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1722                 break;
1723
1724         default:
1725                 return -ENOPROTOOPT;
1726         }
1727
1728         if (len < lv)
1729                 return -EINVAL;
1730         if (len > lv)
1731                 len = lv;
1732         if (copy_to_user(optval, &v, len))
1733                 return -EFAULT;
1734
1735         if (put_user(len, optlen))
1736                 return -EFAULT;
1737
1738         return 0;
1739 }
1740
1741 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1742                                      size_t len)
1743 {
1744         struct sock *sk;
1745         struct vsock_sock *vsk;
1746         const struct vsock_transport *transport;
1747         ssize_t total_written;
1748         long timeout;
1749         int err;
1750         struct vsock_transport_send_notify_data send_data;
1751         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1752
1753         sk = sock->sk;
1754         vsk = vsock_sk(sk);
1755         total_written = 0;
1756         err = 0;
1757
1758         if (msg->msg_flags & MSG_OOB)
1759                 return -EOPNOTSUPP;
1760
1761         lock_sock(sk);
1762
1763         transport = vsk->transport;
1764
1765         /* Callers should not provide a destination with connection oriented
1766          * sockets.
1767          */
1768         if (msg->msg_namelen) {
1769                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1770                 goto out;
1771         }
1772
1773         /* Send data only if both sides are not shutdown in the direction. */
1774         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1775             vsk->peer_shutdown & RCV_SHUTDOWN) {
1776                 err = -EPIPE;
1777                 goto out;
1778         }
1779
1780         if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1781             !vsock_addr_bound(&vsk->local_addr)) {
1782                 err = -ENOTCONN;
1783                 goto out;
1784         }
1785
1786         if (!vsock_addr_bound(&vsk->remote_addr)) {
1787                 err = -EDESTADDRREQ;
1788                 goto out;
1789         }
1790
1791         /* Wait for room in the produce queue to enqueue our user's data. */
1792         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1793
1794         err = transport->notify_send_init(vsk, &send_data);
1795         if (err < 0)
1796                 goto out;
1797
1798         while (total_written < len) {
1799                 ssize_t written;
1800
1801                 add_wait_queue(sk_sleep(sk), &wait);
1802                 while (vsock_stream_has_space(vsk) == 0 &&
1803                        sk->sk_err == 0 &&
1804                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1805                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1806
1807                         /* Don't wait for non-blocking sockets. */
1808                         if (timeout == 0) {
1809                                 err = -EAGAIN;
1810                                 remove_wait_queue(sk_sleep(sk), &wait);
1811                                 goto out_err;
1812                         }
1813
1814                         err = transport->notify_send_pre_block(vsk, &send_data);
1815                         if (err < 0) {
1816                                 remove_wait_queue(sk_sleep(sk), &wait);
1817                                 goto out_err;
1818                         }
1819
1820                         release_sock(sk);
1821                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1822                         lock_sock(sk);
1823                         if (signal_pending(current)) {
1824                                 err = sock_intr_errno(timeout);
1825                                 remove_wait_queue(sk_sleep(sk), &wait);
1826                                 goto out_err;
1827                         } else if (timeout == 0) {
1828                                 err = -EAGAIN;
1829                                 remove_wait_queue(sk_sleep(sk), &wait);
1830                                 goto out_err;
1831                         }
1832                 }
1833                 remove_wait_queue(sk_sleep(sk), &wait);
1834
1835                 /* These checks occur both as part of and after the loop
1836                  * conditional since we need to check before and after
1837                  * sleeping.
1838                  */
1839                 if (sk->sk_err) {
1840                         err = -sk->sk_err;
1841                         goto out_err;
1842                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1843                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1844                         err = -EPIPE;
1845                         goto out_err;
1846                 }
1847
1848                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1849                 if (err < 0)
1850                         goto out_err;
1851
1852                 /* Note that enqueue will only write as many bytes as are free
1853                  * in the produce queue, so we don't need to ensure len is
1854                  * smaller than the queue size.  It is the caller's
1855                  * responsibility to check how many bytes we were able to send.
1856                  */
1857
1858                 if (sk->sk_type == SOCK_SEQPACKET) {
1859                         written = transport->seqpacket_enqueue(vsk,
1860                                                 msg, len - total_written);
1861                 } else {
1862                         written = transport->stream_enqueue(vsk,
1863                                         msg, len - total_written);
1864                 }
1865                 if (written < 0) {
1866                         err = -ENOMEM;
1867                         goto out_err;
1868                 }
1869
1870                 total_written += written;
1871
1872                 err = transport->notify_send_post_enqueue(
1873                                 vsk, written, &send_data);
1874                 if (err < 0)
1875                         goto out_err;
1876
1877         }
1878
1879 out_err:
1880         if (total_written > 0) {
1881                 /* Return number of written bytes only if:
1882                  * 1) SOCK_STREAM socket.
1883                  * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1884                  */
1885                 if (sk->sk_type == SOCK_STREAM || total_written == len)
1886                         err = total_written;
1887         }
1888 out:
1889         release_sock(sk);
1890         return err;
1891 }
1892
1893 static int vsock_connectible_wait_data(struct sock *sk,
1894                                        struct wait_queue_entry *wait,
1895                                        long timeout,
1896                                        struct vsock_transport_recv_notify_data *recv_data,
1897                                        size_t target)
1898 {
1899         const struct vsock_transport *transport;
1900         struct vsock_sock *vsk;
1901         s64 data;
1902         int err;
1903
1904         vsk = vsock_sk(sk);
1905         err = 0;
1906         transport = vsk->transport;
1907
1908         while (1) {
1909                 prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1910                 data = vsock_connectible_has_data(vsk);
1911                 if (data != 0)
1912                         break;
1913
1914                 if (sk->sk_err != 0 ||
1915                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1916                     (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1917                         break;
1918                 }
1919
1920                 /* Don't wait for non-blocking sockets. */
1921                 if (timeout == 0) {
1922                         err = -EAGAIN;
1923                         break;
1924                 }
1925
1926                 if (recv_data) {
1927                         err = transport->notify_recv_pre_block(vsk, target, recv_data);
1928                         if (err < 0)
1929                                 break;
1930                 }
1931
1932                 release_sock(sk);
1933                 timeout = schedule_timeout(timeout);
1934                 lock_sock(sk);
1935
1936                 if (signal_pending(current)) {
1937                         err = sock_intr_errno(timeout);
1938                         break;
1939                 } else if (timeout == 0) {
1940                         err = -EAGAIN;
1941                         break;
1942                 }
1943         }
1944
1945         finish_wait(sk_sleep(sk), wait);
1946
1947         if (err)
1948                 return err;
1949
1950         /* Internal transport error when checking for available
1951          * data. XXX This should be changed to a connection
1952          * reset in a later change.
1953          */
1954         if (data < 0)
1955                 return -ENOMEM;
1956
1957         return data;
1958 }
1959
1960 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1961                                   size_t len, int flags)
1962 {
1963         struct vsock_transport_recv_notify_data recv_data;
1964         const struct vsock_transport *transport;
1965         struct vsock_sock *vsk;
1966         ssize_t copied;
1967         size_t target;
1968         long timeout;
1969         int err;
1970
1971         DEFINE_WAIT(wait);
1972
1973         vsk = vsock_sk(sk);
1974         transport = vsk->transport;
1975
1976         /* We must not copy less than target bytes into the user's buffer
1977          * before returning successfully, so we wait for the consume queue to
1978          * have that much data to consume before dequeueing.  Note that this
1979          * makes it impossible to handle cases where target is greater than the
1980          * queue size.
1981          */
1982         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1983         if (target >= transport->stream_rcvhiwat(vsk)) {
1984                 err = -ENOMEM;
1985                 goto out;
1986         }
1987         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1988         copied = 0;
1989
1990         err = transport->notify_recv_init(vsk, target, &recv_data);
1991         if (err < 0)
1992                 goto out;
1993
1994
1995         while (1) {
1996                 ssize_t read;
1997
1998                 err = vsock_connectible_wait_data(sk, &wait, timeout,
1999                                                   &recv_data, target);
2000                 if (err <= 0)
2001                         break;
2002
2003                 err = transport->notify_recv_pre_dequeue(vsk, target,
2004                                                          &recv_data);
2005                 if (err < 0)
2006                         break;
2007
2008                 read = transport->stream_dequeue(vsk, msg, len - copied, flags);
2009                 if (read < 0) {
2010                         err = -ENOMEM;
2011                         break;
2012                 }
2013
2014                 copied += read;
2015
2016                 err = transport->notify_recv_post_dequeue(vsk, target, read,
2017                                                 !(flags & MSG_PEEK), &recv_data);
2018                 if (err < 0)
2019                         goto out;
2020
2021                 if (read >= target || flags & MSG_PEEK)
2022                         break;
2023
2024                 target -= read;
2025         }
2026
2027         if (sk->sk_err)
2028                 err = -sk->sk_err;
2029         else if (sk->sk_shutdown & RCV_SHUTDOWN)
2030                 err = 0;
2031
2032         if (copied > 0)
2033                 err = copied;
2034
2035 out:
2036         return err;
2037 }
2038
2039 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2040                                      size_t len, int flags)
2041 {
2042         const struct vsock_transport *transport;
2043         struct vsock_sock *vsk;
2044         ssize_t msg_len;
2045         long timeout;
2046         int err = 0;
2047         DEFINE_WAIT(wait);
2048
2049         vsk = vsock_sk(sk);
2050         transport = vsk->transport;
2051
2052         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2053
2054         err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2055         if (err <= 0)
2056                 goto out;
2057
2058         msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2059
2060         if (msg_len < 0) {
2061                 err = -ENOMEM;
2062                 goto out;
2063         }
2064
2065         if (sk->sk_err) {
2066                 err = -sk->sk_err;
2067         } else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2068                 err = 0;
2069         } else {
2070                 /* User sets MSG_TRUNC, so return real length of
2071                  * packet.
2072                  */
2073                 if (flags & MSG_TRUNC)
2074                         err = msg_len;
2075                 else
2076                         err = len - msg_data_left(msg);
2077
2078                 /* Always set MSG_TRUNC if real length of packet is
2079                  * bigger than user's buffer.
2080                  */
2081                 if (msg_len > len)
2082                         msg->msg_flags |= MSG_TRUNC;
2083         }
2084
2085 out:
2086         return err;
2087 }
2088
2089 static int
2090 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2091                           int flags)
2092 {
2093         struct sock *sk;
2094         struct vsock_sock *vsk;
2095         const struct vsock_transport *transport;
2096         int err;
2097
2098         sk = sock->sk;
2099         vsk = vsock_sk(sk);
2100         err = 0;
2101
2102         lock_sock(sk);
2103
2104         transport = vsk->transport;
2105
2106         if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2107                 /* Recvmsg is supposed to return 0 if a peer performs an
2108                  * orderly shutdown. Differentiate between that case and when a
2109                  * peer has not connected or a local shutdown occurred with the
2110                  * SOCK_DONE flag.
2111                  */
2112                 if (sock_flag(sk, SOCK_DONE))
2113                         err = 0;
2114                 else
2115                         err = -ENOTCONN;
2116
2117                 goto out;
2118         }
2119
2120         if (flags & MSG_OOB) {
2121                 err = -EOPNOTSUPP;
2122                 goto out;
2123         }
2124
2125         /* We don't check peer_shutdown flag here since peer may actually shut
2126          * down, but there can be data in the queue that a local socket can
2127          * receive.
2128          */
2129         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2130                 err = 0;
2131                 goto out;
2132         }
2133
2134         /* It is valid on Linux to pass in a zero-length receive buffer.  This
2135          * is not an error.  We may as well bail out now.
2136          */
2137         if (!len) {
2138                 err = 0;
2139                 goto out;
2140         }
2141
2142         if (sk->sk_type == SOCK_STREAM)
2143                 err = __vsock_stream_recvmsg(sk, msg, len, flags);
2144         else
2145                 err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2146
2147 out:
2148         release_sock(sk);
2149         return err;
2150 }
2151
2152 static int vsock_set_rcvlowat(struct sock *sk, int val)
2153 {
2154         const struct vsock_transport *transport;
2155         struct vsock_sock *vsk;
2156
2157         vsk = vsock_sk(sk);
2158
2159         if (val > vsk->buffer_size)
2160                 return -EINVAL;
2161
2162         transport = vsk->transport;
2163
2164         if (transport && transport->set_rcvlowat)
2165                 return transport->set_rcvlowat(vsk, val);
2166
2167         WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
2168         return 0;
2169 }
2170
2171 static const struct proto_ops vsock_stream_ops = {
2172         .family = PF_VSOCK,
2173         .owner = THIS_MODULE,
2174         .release = vsock_release,
2175         .bind = vsock_bind,
2176         .connect = vsock_connect,
2177         .socketpair = sock_no_socketpair,
2178         .accept = vsock_accept,
2179         .getname = vsock_getname,
2180         .poll = vsock_poll,
2181         .ioctl = sock_no_ioctl,
2182         .listen = vsock_listen,
2183         .shutdown = vsock_shutdown,
2184         .setsockopt = vsock_connectible_setsockopt,
2185         .getsockopt = vsock_connectible_getsockopt,
2186         .sendmsg = vsock_connectible_sendmsg,
2187         .recvmsg = vsock_connectible_recvmsg,
2188         .mmap = sock_no_mmap,
2189         .sendpage = sock_no_sendpage,
2190         .set_rcvlowat = vsock_set_rcvlowat,
2191 };
2192
2193 static const struct proto_ops vsock_seqpacket_ops = {
2194         .family = PF_VSOCK,
2195         .owner = THIS_MODULE,
2196         .release = vsock_release,
2197         .bind = vsock_bind,
2198         .connect = vsock_connect,
2199         .socketpair = sock_no_socketpair,
2200         .accept = vsock_accept,
2201         .getname = vsock_getname,
2202         .poll = vsock_poll,
2203         .ioctl = sock_no_ioctl,
2204         .listen = vsock_listen,
2205         .shutdown = vsock_shutdown,
2206         .setsockopt = vsock_connectible_setsockopt,
2207         .getsockopt = vsock_connectible_getsockopt,
2208         .sendmsg = vsock_connectible_sendmsg,
2209         .recvmsg = vsock_connectible_recvmsg,
2210         .mmap = sock_no_mmap,
2211         .sendpage = sock_no_sendpage,
2212 };
2213
2214 static int vsock_create(struct net *net, struct socket *sock,
2215                         int protocol, int kern)
2216 {
2217         struct vsock_sock *vsk;
2218         struct sock *sk;
2219         int ret;
2220
2221         if (!sock)
2222                 return -EINVAL;
2223
2224         if (protocol && protocol != PF_VSOCK)
2225                 return -EPROTONOSUPPORT;
2226
2227         switch (sock->type) {
2228         case SOCK_DGRAM:
2229                 sock->ops = &vsock_dgram_ops;
2230                 break;
2231         case SOCK_STREAM:
2232                 sock->ops = &vsock_stream_ops;
2233                 break;
2234         case SOCK_SEQPACKET:
2235                 sock->ops = &vsock_seqpacket_ops;
2236                 break;
2237         default:
2238                 return -ESOCKTNOSUPPORT;
2239         }
2240
2241         sock->state = SS_UNCONNECTED;
2242
2243         sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2244         if (!sk)
2245                 return -ENOMEM;
2246
2247         vsk = vsock_sk(sk);
2248
2249         if (sock->type == SOCK_DGRAM) {
2250                 ret = vsock_assign_transport(vsk, NULL);
2251                 if (ret < 0) {
2252                         sock_put(sk);
2253                         return ret;
2254                 }
2255         }
2256
2257         vsock_insert_unbound(vsk);
2258
2259         return 0;
2260 }
2261
2262 static const struct net_proto_family vsock_family_ops = {
2263         .family = AF_VSOCK,
2264         .create = vsock_create,
2265         .owner = THIS_MODULE,
2266 };
2267
2268 static long vsock_dev_do_ioctl(struct file *filp,
2269                                unsigned int cmd, void __user *ptr)
2270 {
2271         u32 __user *p = ptr;
2272         u32 cid = VMADDR_CID_ANY;
2273         int retval = 0;
2274
2275         switch (cmd) {
2276         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2277                 /* To be compatible with the VMCI behavior, we prioritize the
2278                  * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2279                  */
2280                 if (transport_g2h)
2281                         cid = transport_g2h->get_local_cid();
2282                 else if (transport_h2g)
2283                         cid = transport_h2g->get_local_cid();
2284
2285                 if (put_user(cid, p) != 0)
2286                         retval = -EFAULT;
2287                 break;
2288
2289         default:
2290                 retval = -ENOIOCTLCMD;
2291         }
2292
2293         return retval;
2294 }
2295
2296 static long vsock_dev_ioctl(struct file *filp,
2297                             unsigned int cmd, unsigned long arg)
2298 {
2299         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2300 }
2301
2302 #ifdef CONFIG_COMPAT
2303 static long vsock_dev_compat_ioctl(struct file *filp,
2304                                    unsigned int cmd, unsigned long arg)
2305 {
2306         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2307 }
2308 #endif
2309
2310 static const struct file_operations vsock_device_ops = {
2311         .owner          = THIS_MODULE,
2312         .unlocked_ioctl = vsock_dev_ioctl,
2313 #ifdef CONFIG_COMPAT
2314         .compat_ioctl   = vsock_dev_compat_ioctl,
2315 #endif
2316         .open           = nonseekable_open,
2317 };
2318
2319 static struct miscdevice vsock_device = {
2320         .name           = "vsock",
2321         .fops           = &vsock_device_ops,
2322 };
2323
2324 static int __init vsock_init(void)
2325 {
2326         int err = 0;
2327
2328         vsock_init_tables();
2329
2330         vsock_proto.owner = THIS_MODULE;
2331         vsock_device.minor = MISC_DYNAMIC_MINOR;
2332         err = misc_register(&vsock_device);
2333         if (err) {
2334                 pr_err("Failed to register misc device\n");
2335                 goto err_reset_transport;
2336         }
2337
2338         err = proto_register(&vsock_proto, 1);  /* we want our slab */
2339         if (err) {
2340                 pr_err("Cannot register vsock protocol\n");
2341                 goto err_deregister_misc;
2342         }
2343
2344         err = sock_register(&vsock_family_ops);
2345         if (err) {
2346                 pr_err("could not register af_vsock (%d) address family: %d\n",
2347                        AF_VSOCK, err);
2348                 goto err_unregister_proto;
2349         }
2350
2351         return 0;
2352
2353 err_unregister_proto:
2354         proto_unregister(&vsock_proto);
2355 err_deregister_misc:
2356         misc_deregister(&vsock_device);
2357 err_reset_transport:
2358         return err;
2359 }
2360
2361 static void __exit vsock_exit(void)
2362 {
2363         misc_deregister(&vsock_device);
2364         sock_unregister(AF_VSOCK);
2365         proto_unregister(&vsock_proto);
2366 }
2367
2368 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2369 {
2370         return vsk->transport;
2371 }
2372 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2373
2374 int vsock_core_register(const struct vsock_transport *t, int features)
2375 {
2376         const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2377         int err = mutex_lock_interruptible(&vsock_register_mutex);
2378
2379         if (err)
2380                 return err;
2381
2382         t_h2g = transport_h2g;
2383         t_g2h = transport_g2h;
2384         t_dgram = transport_dgram;
2385         t_local = transport_local;
2386
2387         if (features & VSOCK_TRANSPORT_F_H2G) {
2388                 if (t_h2g) {
2389                         err = -EBUSY;
2390                         goto err_busy;
2391                 }
2392                 t_h2g = t;
2393         }
2394
2395         if (features & VSOCK_TRANSPORT_F_G2H) {
2396                 if (t_g2h) {
2397                         err = -EBUSY;
2398                         goto err_busy;
2399                 }
2400                 t_g2h = t;
2401         }
2402
2403         if (features & VSOCK_TRANSPORT_F_DGRAM) {
2404                 if (t_dgram) {
2405                         err = -EBUSY;
2406                         goto err_busy;
2407                 }
2408                 t_dgram = t;
2409         }
2410
2411         if (features & VSOCK_TRANSPORT_F_LOCAL) {
2412                 if (t_local) {
2413                         err = -EBUSY;
2414                         goto err_busy;
2415                 }
2416                 t_local = t;
2417         }
2418
2419         transport_h2g = t_h2g;
2420         transport_g2h = t_g2h;
2421         transport_dgram = t_dgram;
2422         transport_local = t_local;
2423
2424 err_busy:
2425         mutex_unlock(&vsock_register_mutex);
2426         return err;
2427 }
2428 EXPORT_SYMBOL_GPL(vsock_core_register);
2429
2430 void vsock_core_unregister(const struct vsock_transport *t)
2431 {
2432         mutex_lock(&vsock_register_mutex);
2433
2434         if (transport_h2g == t)
2435                 transport_h2g = NULL;
2436
2437         if (transport_g2h == t)
2438                 transport_g2h = NULL;
2439
2440         if (transport_dgram == t)
2441                 transport_dgram = NULL;
2442
2443         if (transport_local == t)
2444                 transport_local = NULL;
2445
2446         mutex_unlock(&vsock_register_mutex);
2447 }
2448 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2449
2450 module_init(vsock_init);
2451 module_exit(vsock_exit);
2452
2453 MODULE_AUTHOR("VMware, Inc.");
2454 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2455 MODULE_VERSION("1.0.2.0-k");
2456 MODULE_LICENSE("GPL v2");