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 struct proto vsock_proto = {
 120         .name = "AF_VSOCK",
 121         .owner = THIS_MODULE,
 122         .obj_size = sizeof(struct vsock_sock),
 123 #ifdef CONFIG_BPF_SYSCALL
 124         .psock_update_sk_prot = vsock_bpf_update_proto,
 125 #endif
 126 };
 127
 128 /* The default peer timeout indicates how long we will wait for a peer response
 129  * to a control message.
 130  */
 131 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
 132
 133 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
 134 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
 135 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
 136
 137 /* Transport used for host->guest communication */
 138 static const struct vsock_transport *transport_h2g;
 139 /* Transport used for guest->host communication */
 140 static const struct vsock_transport *transport_g2h;
 141 /* Transport used for DGRAM communication */
 142 static const struct vsock_transport *transport_dgram;
 143 /* Transport used for local communication */
 144 static const struct vsock_transport *transport_local;
 145 static DEFINE_MUTEX(vsock_register_mutex);
 146
 147 /**** UTILS ****/
 148
 149 /* Each bound VSocket is stored in the bind hash table and each connected
 150  * VSocket is stored in the connected hash table.
 151  *
 152  * Unbound sockets are all put on the same list attached to the end of the hash
 153  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
 154  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
 155  * represents the list that addr hashes to).
 156  *
 157  * Specifically, we initialize the vsock_bind_table array to a size of
 158  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
 159  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
 160  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
 161  * mods with VSOCK_HASH_SIZE to ensure this.
 162  */
 163 #define MAX_PORT_RETRIES        24
 164
 165 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
 166 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
 167 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
 168
 169 /* XXX This can probably be implemented in a better way. */
 170 #define VSOCK_CONN_HASH(src, dst)                               \
 171         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
 172 #define vsock_connected_sockets(src, dst)               \
 173         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
 174 #define vsock_connected_sockets_vsk(vsk)                                \
 175         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
 176
 177 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
 178 EXPORT_SYMBOL_GPL(vsock_bind_table);
 179 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
 180 EXPORT_SYMBOL_GPL(vsock_connected_table);
 181 DEFINE_SPINLOCK(vsock_table_lock);
 182 EXPORT_SYMBOL_GPL(vsock_table_lock);
 183
 184 /* Autobind this socket to the local address if necessary. */
 185 static int vsock_auto_bind(struct vsock_sock *vsk)
 186 {
 187         struct sock *sk = sk_vsock(vsk);
 188         struct sockaddr_vm local_addr;
 189
 190         if (vsock_addr_bound(&vsk->local_addr))
 191                 return 0;
 192         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 193         return __vsock_bind(sk, &local_addr);
 194 }
 195
 196 static void vsock_init_tables(void)
 197 {
 198         int i;
 199
 200         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
 201                 INIT_LIST_HEAD(&vsock_bind_table[i]);
 202
 203         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
 204                 INIT_LIST_HEAD(&vsock_connected_table[i]);
 205 }
 206
 207 static void __vsock_insert_bound(struct list_head *list,
 208                                  struct vsock_sock *vsk)
 209 {
 210         sock_hold(&vsk->sk);
 211         list_add(&vsk->bound_table, list);
 212 }
 213
 214 static void __vsock_insert_connected(struct list_head *list,
 215                                      struct vsock_sock *vsk)
 216 {
 217         sock_hold(&vsk->sk);
 218         list_add(&vsk->connected_table, list);
 219 }
 220
 221 static void __vsock_remove_bound(struct vsock_sock *vsk)
 222 {
 223         list_del_init(&vsk->bound_table);
 224         sock_put(&vsk->sk);
 225 }
 226
 227 static void __vsock_remove_connected(struct vsock_sock *vsk)
 228 {
 229         list_del_init(&vsk->connected_table);
 230         sock_put(&vsk->sk);
 231 }
 232
 233 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
 234 {
 235         struct vsock_sock *vsk;
 236
 237         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
 238                 if (vsock_addr_equals_addr(addr, &vsk->local_addr))
 239                         return sk_vsock(vsk);
 240
 241                 if (addr->svm_port == vsk->local_addr.svm_port &&
 242                     (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
 243                      addr->svm_cid == VMADDR_CID_ANY))
 244                         return sk_vsock(vsk);
 245         }
 246
 247         return NULL;
 248 }
 249
 250 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
 251                                                   struct sockaddr_vm *dst)
 252 {
 253         struct vsock_sock *vsk;
 254
 255         list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
 256                             connected_table) {
 257                 if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
 258                     dst->svm_port == vsk->local_addr.svm_port) {
 259                         return sk_vsock(vsk);
 260                 }
 261         }
 262
 263         return NULL;
 264 }
 265
 266 static void vsock_insert_unbound(struct vsock_sock *vsk)
 267 {
 268         spin_lock_bh(&vsock_table_lock);
 269         __vsock_insert_bound(vsock_unbound_sockets, vsk);
 270         spin_unlock_bh(&vsock_table_lock);
 271 }
 272
 273 void vsock_insert_connected(struct vsock_sock *vsk)
 274 {
 275         struct list_head *list = vsock_connected_sockets(
 276                 &vsk->remote_addr, &vsk->local_addr);
 277
 278         spin_lock_bh(&vsock_table_lock);
 279         __vsock_insert_connected(list, vsk);
 280         spin_unlock_bh(&vsock_table_lock);
 281 }
 282 EXPORT_SYMBOL_GPL(vsock_insert_connected);
 283
 284 void vsock_remove_bound(struct vsock_sock *vsk)
 285 {
 286         spin_lock_bh(&vsock_table_lock);
 287         if (__vsock_in_bound_table(vsk))
 288                 __vsock_remove_bound(vsk);
 289         spin_unlock_bh(&vsock_table_lock);
 290 }
 291 EXPORT_SYMBOL_GPL(vsock_remove_bound);
 292
 293 void vsock_remove_connected(struct vsock_sock *vsk)
 294 {
 295         spin_lock_bh(&vsock_table_lock);
 296         if (__vsock_in_connected_table(vsk))
 297                 __vsock_remove_connected(vsk);
 298         spin_unlock_bh(&vsock_table_lock);
 299 }
 300 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 301
 302 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 303 {
 304         struct sock *sk;
 305
 306         spin_lock_bh(&vsock_table_lock);
 307         sk = __vsock_find_bound_socket(addr);
 308         if (sk)
 309                 sock_hold(sk);
 310
 311         spin_unlock_bh(&vsock_table_lock);
 312
 313         return sk;
 314 }
 315 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 316
 317 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 318                                          struct sockaddr_vm *dst)
 319 {
 320         struct sock *sk;
 321
 322         spin_lock_bh(&vsock_table_lock);
 323         sk = __vsock_find_connected_socket(src, dst);
 324         if (sk)
 325                 sock_hold(sk);
 326
 327         spin_unlock_bh(&vsock_table_lock);
 328
 329         return sk;
 330 }
 331 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 332
 333 void vsock_remove_sock(struct vsock_sock *vsk)
 334 {
 335         vsock_remove_bound(vsk);
 336         vsock_remove_connected(vsk);
 337 }
 338 EXPORT_SYMBOL_GPL(vsock_remove_sock);
 339
 340 void vsock_for_each_connected_socket(struct vsock_transport *transport,
 341                                      void (*fn)(struct sock *sk))
 342 {
 343         int i;
 344
 345         spin_lock_bh(&vsock_table_lock);
 346
 347         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
 348                 struct vsock_sock *vsk;
 349                 list_for_each_entry(vsk, &vsock_connected_table[i],
 350                                     connected_table) {
 351                         if (vsk->transport != transport)
 352                                 continue;
 353
 354                         fn(sk_vsock(vsk));
 355                 }
 356         }
 357
 358         spin_unlock_bh(&vsock_table_lock);
 359 }
 360 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
 361
 362 void vsock_add_pending(struct sock *listener, struct sock *pending)
 363 {
 364         struct vsock_sock *vlistener;
 365         struct vsock_sock *vpending;
 366
 367         vlistener = vsock_sk(listener);
 368         vpending = vsock_sk(pending);
 369
 370         sock_hold(pending);
 371         sock_hold(listener);
 372         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 373 }
 374 EXPORT_SYMBOL_GPL(vsock_add_pending);
 375
 376 void vsock_remove_pending(struct sock *listener, struct sock *pending)
 377 {
 378         struct vsock_sock *vpending = vsock_sk(pending);
 379
 380         list_del_init(&vpending->pending_links);
 381         sock_put(listener);
 382         sock_put(pending);
 383 }
 384 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 385
 386 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 387 {
 388         struct vsock_sock *vlistener;
 389         struct vsock_sock *vconnected;
 390
 391         vlistener = vsock_sk(listener);
 392         vconnected = vsock_sk(connected);
 393
 394         sock_hold(connected);
 395         sock_hold(listener);
 396         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 397 }
 398 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 399
 400 static bool vsock_use_local_transport(unsigned int remote_cid)
 401 {
 402         if (!transport_local)
 403                 return false;
 404
 405         if (remote_cid == VMADDR_CID_LOCAL)
 406                 return true;
 407
 408         if (transport_g2h) {
 409                 return remote_cid == transport_g2h->get_local_cid();
 410         } else {
 411                 return remote_cid == VMADDR_CID_HOST;
 412         }
 413 }
 414
 415 static void vsock_deassign_transport(struct vsock_sock *vsk)
 416 {
 417         if (!vsk->transport)
 418                 return;
 419
 420         vsk->transport->destruct(vsk);
 421         module_put(vsk->transport->module);
 422         vsk->transport = NULL;
 423 }
 424
 425 /* Assign a transport to a socket and call the .init transport callback.
 426  *
 427  * Note: for connection oriented socket this must be called when vsk->remote_addr
 428  * is set (e.g. during the connect() or when a connection request on a listener
 429  * socket is received).
 430  * The vsk->remote_addr is used to decide which transport to use:
 431  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 432  *    g2h is not loaded, will use local transport;
 433  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 434  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 435  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 436  */
 437 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 438 {
 439         const struct vsock_transport *new_transport;
 440         struct sock *sk = sk_vsock(vsk);
 441         unsigned int remote_cid = vsk->remote_addr.svm_cid;
 442         __u8 remote_flags;
 443         int ret;
 444
 445         /* If the packet is coming with the source and destination CIDs higher
 446          * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 447          * forwarded to the host should be established. Then the host will
 448          * need to forward the packets to the guest.
 449          *
 450          * The flag is set on the (listen) receive path (psk is not NULL). On
 451          * the connect path the flag can be set by the user space application.
 452          */
 453         if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 454             vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 455                 vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 456
 457         remote_flags = vsk->remote_addr.svm_flags;
 458
 459         switch (sk->sk_type) {
 460         case SOCK_DGRAM:
 461                 new_transport = transport_dgram;
 462                 break;
 463         case SOCK_STREAM:
 464         case SOCK_SEQPACKET:
 465                 if (vsock_use_local_transport(remote_cid))
 466                         new_transport = transport_local;
 467                 else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 468                          (remote_flags & VMADDR_FLAG_TO_HOST))
 469                         new_transport = transport_g2h;
 470                 else
 471                         new_transport = transport_h2g;
 472                 break;
 473         default:
 474                 return -ESOCKTNOSUPPORT;
 475         }
 476
 477         if (vsk->transport) {
 478                 if (vsk->transport == new_transport)
 479                         return 0;
 480
 481                 /* transport->release() must be called with sock lock acquired.
 482                  * This path can only be taken during vsock_connect(), where we
 483                  * have already held the sock lock. In the other cases, this
 484                  * function is called on a new socket which is not assigned to
 485                  * any transport.
 486                  */
 487                 vsk->transport->release(vsk);
 488                 vsock_deassign_transport(vsk);
 489         }
 490
 491         /* We increase the module refcnt to prevent the transport unloading
 492          * while there are open sockets assigned to it.
 493          */
 494         if (!new_transport || !try_module_get(new_transport->module))
 495                 return -ENODEV;
 496
 497         if (sk->sk_type == SOCK_SEQPACKET) {
 498                 if (!new_transport->seqpacket_allow ||
 499                     !new_transport->seqpacket_allow(remote_cid)) {
 500                         module_put(new_transport->module);
 501                         return -ESOCKTNOSUPPORT;
 502                 }
 503         }
 504
 505         ret = new_transport->init(vsk, psk);
 506         if (ret) {
 507                 module_put(new_transport->module);
 508                 return ret;
 509         }
 510
 511         vsk->transport = new_transport;
 512
 513         return 0;
 514 }
 515 EXPORT_SYMBOL_GPL(vsock_assign_transport);
 516
 517 bool vsock_find_cid(unsigned int cid)
 518 {
 519         if (transport_g2h && cid == transport_g2h->get_local_cid())
 520                 return true;
 521
 522         if (transport_h2g && cid == VMADDR_CID_HOST)
 523                 return true;
 524
 525         if (transport_local && cid == VMADDR_CID_LOCAL)
 526                 return true;
 527
 528         return false;
 529 }
 530 EXPORT_SYMBOL_GPL(vsock_find_cid);
 531
 532 static struct sock *vsock_dequeue_accept(struct sock *listener)
 533 {
 534         struct vsock_sock *vlistener;
 535         struct vsock_sock *vconnected;
 536
 537         vlistener = vsock_sk(listener);
 538
 539         if (list_empty(&vlistener->accept_queue))
 540                 return NULL;
 541
 542         vconnected = list_entry(vlistener->accept_queue.next,
 543                                 struct vsock_sock, accept_queue);
 544
 545         list_del_init(&vconnected->accept_queue);
 546         sock_put(listener);
 547         /* The caller will need a reference on the connected socket so we let
 548          * it call sock_put().
 549          */
 550
 551         return sk_vsock(vconnected);
 552 }
 553
 554 static bool vsock_is_accept_queue_empty(struct sock *sk)
 555 {
 556         struct vsock_sock *vsk = vsock_sk(sk);
 557         return list_empty(&vsk->accept_queue);
 558 }
 559
 560 static bool vsock_is_pending(struct sock *sk)
 561 {
 562         struct vsock_sock *vsk = vsock_sk(sk);
 563         return !list_empty(&vsk->pending_links);
 564 }
 565
 566 static int vsock_send_shutdown(struct sock *sk, int mode)
 567 {
 568         struct vsock_sock *vsk = vsock_sk(sk);
 569
 570         if (!vsk->transport)
 571                 return -ENODEV;
 572
 573         return vsk->transport->shutdown(vsk, mode);
 574 }
 575
 576 static void vsock_pending_work(struct work_struct *work)
 577 {
 578         struct sock *sk;
 579         struct sock *listener;
 580         struct vsock_sock *vsk;
 581         bool cleanup;
 582
 583         vsk = container_of(work, struct vsock_sock, pending_work.work);
 584         sk = sk_vsock(vsk);
 585         listener = vsk->listener;
 586         cleanup = true;
 587
 588         lock_sock(listener);
 589         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 590
 591         if (vsock_is_pending(sk)) {
 592                 vsock_remove_pending(listener, sk);
 593
 594                 sk_acceptq_removed(listener);
 595         } else if (!vsk->rejected) {
 596                 /* We are not on the pending list and accept() did not reject
 597                  * us, so we must have been accepted by our user process.  We
 598                  * just need to drop our references to the sockets and be on
 599                  * our way.
 600                  */
 601                 cleanup = false;
 602                 goto out;
 603         }
 604
 605         /* We need to remove ourself from the global connected sockets list so
 606          * incoming packets can't find this socket, and to reduce the reference
 607          * count.
 608          */
 609         vsock_remove_connected(vsk);
 610
 611         sk->sk_state = TCP_CLOSE;
 612
 613 out:
 614         release_sock(sk);
 615         release_sock(listener);
 616         if (cleanup)
 617                 sock_put(sk);
 618
 619         sock_put(sk);
 620         sock_put(listener);
 621 }
 622
 623 /**** SOCKET OPERATIONS ****/
 624
 625 static int __vsock_bind_connectible(struct vsock_sock *vsk,
 626                                     struct sockaddr_vm *addr)
 627 {
 628         static u32 port;
 629         struct sockaddr_vm new_addr;
 630
 631         if (!port)
 632                 port = get_random_u32_above(LAST_RESERVED_PORT);
 633
 634         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 635
 636         if (addr->svm_port == VMADDR_PORT_ANY) {
 637                 bool found = false;
 638                 unsigned int i;
 639
 640                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
 641                         if (port <= LAST_RESERVED_PORT)
 642                                 port = LAST_RESERVED_PORT + 1;
 643
 644                         new_addr.svm_port = port++;
 645
 646                         if (!__vsock_find_bound_socket(&new_addr)) {
 647                                 found = true;
 648                                 break;
 649                         }
 650                 }
 651
 652                 if (!found)
 653                         return -EADDRNOTAVAIL;
 654         } else {
 655                 /* If port is in reserved range, ensure caller
 656                  * has necessary privileges.
 657                  */
 658                 if (addr->svm_port <= LAST_RESERVED_PORT &&
 659                     !capable(CAP_NET_BIND_SERVICE)) {
 660                         return -EACCES;
 661                 }
 662
 663                 if (__vsock_find_bound_socket(&new_addr))
 664                         return -EADDRINUSE;
 665         }
 666
 667         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
 668
 669         /* Remove connection oriented sockets from the unbound list and add them
 670          * to the hash table for easy lookup by its address.  The unbound list
 671          * is simply an extra entry at the end of the hash table, a trick used
 672          * by AF_UNIX.
 673          */
 674         __vsock_remove_bound(vsk);
 675         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
 676
 677         return 0;
 678 }
 679
 680 static int __vsock_bind_dgram(struct vsock_sock *vsk,
 681                               struct sockaddr_vm *addr)
 682 {
 683         return vsk->transport->dgram_bind(vsk, addr);
 684 }
 685
 686 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 687 {
 688         struct vsock_sock *vsk = vsock_sk(sk);
 689         int retval;
 690
 691         /* First ensure this socket isn't already bound. */
 692         if (vsock_addr_bound(&vsk->local_addr))
 693                 return -EINVAL;
 694
 695         /* Now bind to the provided address or select appropriate values if
 696          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
 697          * like AF_INET prevents binding to a non-local IP address (in most
 698          * cases), we only allow binding to a local CID.
 699          */
 700         if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
 701                 return -EADDRNOTAVAIL;
 702
 703         switch (sk->sk_socket->type) {
 704         case SOCK_STREAM:
 705         case SOCK_SEQPACKET:
 706                 spin_lock_bh(&vsock_table_lock);
 707                 retval = __vsock_bind_connectible(vsk, addr);
 708                 spin_unlock_bh(&vsock_table_lock);
 709                 break;
 710
 711         case SOCK_DGRAM:
 712                 retval = __vsock_bind_dgram(vsk, addr);
 713                 break;
 714
 715         default:
 716                 retval = -EINVAL;
 717                 break;
 718         }
 719
 720         return retval;
 721 }
 722
 723 static void vsock_connect_timeout(struct work_struct *work);
 724
 725 static struct sock *__vsock_create(struct net *net,
 726                                    struct socket *sock,
 727                                    struct sock *parent,
 728                                    gfp_t priority,
 729                                    unsigned short type,
 730                                    int kern)
 731 {
 732         struct sock *sk;
 733         struct vsock_sock *psk;
 734         struct vsock_sock *vsk;
 735
 736         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 737         if (!sk)
 738                 return NULL;
 739
 740         sock_init_data(sock, sk);
 741
 742         /* sk->sk_type is normally set in sock_init_data, but only if sock is
 743          * non-NULL. We make sure that our sockets always have a type by
 744          * setting it here if needed.
 745          */
 746         if (!sock)
 747                 sk->sk_type = type;
 748
 749         vsk = vsock_sk(sk);
 750         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 751         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 752
 753         sk->sk_destruct = vsock_sk_destruct;
 754         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 755         sock_reset_flag(sk, SOCK_DONE);
 756
 757         INIT_LIST_HEAD(&vsk->bound_table);
 758         INIT_LIST_HEAD(&vsk->connected_table);
 759         vsk->listener = NULL;
 760         INIT_LIST_HEAD(&vsk->pending_links);
 761         INIT_LIST_HEAD(&vsk->accept_queue);
 762         vsk->rejected = false;
 763         vsk->sent_request = false;
 764         vsk->ignore_connecting_rst = false;
 765         vsk->peer_shutdown = 0;
 766         INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 767         INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 768
 769         psk = parent ? vsock_sk(parent) : NULL;
 770         if (parent) {
 771                 vsk->trusted = psk->trusted;
 772                 vsk->owner = get_cred(psk->owner);
 773                 vsk->connect_timeout = psk->connect_timeout;
 774                 vsk->buffer_size = psk->buffer_size;
 775                 vsk->buffer_min_size = psk->buffer_min_size;
 776                 vsk->buffer_max_size = psk->buffer_max_size;
 777                 security_sk_clone(parent, sk);
 778         } else {
 779                 vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
 780                 vsk->owner = get_current_cred();
 781                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 782                 vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
 783                 vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
 784                 vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
 785         }
 786
 787         return sk;
 788 }
 789
 790 static bool sock_type_connectible(u16 type)
 791 {
 792         return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
 793 }
 794
 795 static void __vsock_release(struct sock *sk, int level)
 796 {
 797         if (sk) {
 798                 struct sock *pending;
 799                 struct vsock_sock *vsk;
 800
 801                 vsk = vsock_sk(sk);
 802                 pending = NULL; /* Compiler warning. */
 803
 804                 /* When "level" is SINGLE_DEPTH_NESTING, use the nested
 805                  * version to avoid the warning "possible recursive locking
 806                  * detected". When "level" is 0, lock_sock_nested(sk, level)
 807                  * is the same as lock_sock(sk).
 808                  */
 809                 lock_sock_nested(sk, level);
 810
 811                 if (vsk->transport)
 812                         vsk->transport->release(vsk);
 813                 else if (sock_type_connectible(sk->sk_type))
 814                         vsock_remove_sock(vsk);
 815
 816                 sock_orphan(sk);
 817                 sk->sk_shutdown = SHUTDOWN_MASK;
 818
 819                 skb_queue_purge(&sk->sk_receive_queue);
 820
 821                 /* Clean up any sockets that never were accepted. */
 822                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 823                         __vsock_release(pending, SINGLE_DEPTH_NESTING);
 824                         sock_put(pending);
 825                 }
 826
 827                 release_sock(sk);
 828                 sock_put(sk);
 829         }
 830 }
 831
 832 static void vsock_sk_destruct(struct sock *sk)
 833 {
 834         struct vsock_sock *vsk = vsock_sk(sk);
 835
 836         vsock_deassign_transport(vsk);
 837
 838         /* When clearing these addresses, there's no need to set the family and
 839          * possibly register the address family with the kernel.
 840          */
 841         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 842         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 843
 844         put_cred(vsk->owner);
 845 }
 846
 847 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 848 {
 849         int err;
 850
 851         err = sock_queue_rcv_skb(sk, skb);
 852         if (err)
 853                 kfree_skb(skb);
 854
 855         return err;
 856 }
 857
 858 struct sock *vsock_create_connected(struct sock *parent)
 859 {
 860         return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
 861                               parent->sk_type, 0);
 862 }
 863 EXPORT_SYMBOL_GPL(vsock_create_connected);
 864
 865 s64 vsock_stream_has_data(struct vsock_sock *vsk)
 866 {
 867         return vsk->transport->stream_has_data(vsk);
 868 }
 869 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 870
 871 s64 vsock_connectible_has_data(struct vsock_sock *vsk)
 872 {
 873         struct sock *sk = sk_vsock(vsk);
 874
 875         if (sk->sk_type == SOCK_SEQPACKET)
 876                 return vsk->transport->seqpacket_has_data(vsk);
 877         else
 878                 return vsock_stream_has_data(vsk);
 879 }
 880 EXPORT_SYMBOL_GPL(vsock_connectible_has_data);
 881
 882 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 883 {
 884         return vsk->transport->stream_has_space(vsk);
 885 }
 886 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 887
 888 void vsock_data_ready(struct sock *sk)
 889 {
 890         struct vsock_sock *vsk = vsock_sk(sk);
 891
 892         if (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
 893             sock_flag(sk, SOCK_DONE))
 894                 sk->sk_data_ready(sk);
 895 }
 896 EXPORT_SYMBOL_GPL(vsock_data_ready);
 897
 898 static int vsock_release(struct socket *sock)
 899 {
 900         __vsock_release(sock->sk, 0);
 901         sock->sk = NULL;
 902         sock->state = SS_FREE;
 903
 904         return 0;
 905 }
 906
 907 static int
 908 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 909 {
 910         int err;
 911         struct sock *sk;
 912         struct sockaddr_vm *vm_addr;
 913
 914         sk = sock->sk;
 915
 916         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 917                 return -EINVAL;
 918
 919         lock_sock(sk);
 920         err = __vsock_bind(sk, vm_addr);
 921         release_sock(sk);
 922
 923         return err;
 924 }
 925
 926 static int vsock_getname(struct socket *sock,
 927                          struct sockaddr *addr, int peer)
 928 {
 929         int err;
 930         struct sock *sk;
 931         struct vsock_sock *vsk;
 932         struct sockaddr_vm *vm_addr;
 933
 934         sk = sock->sk;
 935         vsk = vsock_sk(sk);
 936         err = 0;
 937
 938         lock_sock(sk);
 939
 940         if (peer) {
 941                 if (sock->state != SS_CONNECTED) {
 942                         err = -ENOTCONN;
 943                         goto out;
 944                 }
 945                 vm_addr = &vsk->remote_addr;
 946         } else {
 947                 vm_addr = &vsk->local_addr;
 948         }
 949
 950         if (!vm_addr) {
 951                 err = -EINVAL;
 952                 goto out;
 953         }
 954
 955         /* sys_getsockname() and sys_getpeername() pass us a
 956          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 957          * that macro is defined in socket.c instead of .h, so we hardcode its
 958          * value here.
 959          */
 960         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 961         memcpy(addr, vm_addr, sizeof(*vm_addr));
 962         err = sizeof(*vm_addr);
 963
 964 out:
 965         release_sock(sk);
 966         return err;
 967 }
 968
 969 static int vsock_shutdown(struct socket *sock, int mode)
 970 {
 971         int err;
 972         struct sock *sk;
 973
 974         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 975          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 976          * here like the other address families do.  Note also that the
 977          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 978          * which is what we want.
 979          */
 980         mode++;
 981
 982         if ((mode & ~SHUTDOWN_MASK) || !mode)
 983                 return -EINVAL;
 984
 985         /* If this is a connection oriented socket and it is not connected then
 986          * bail out immediately.  If it is a DGRAM socket then we must first
 987          * kick the socket so that it wakes up from any sleeping calls, for
 988          * example recv(), and then afterwards return the error.
 989          */
 990
 991         sk = sock->sk;
 992
 993         lock_sock(sk);
 994         if (sock->state == SS_UNCONNECTED) {
 995                 err = -ENOTCONN;
 996                 if (sock_type_connectible(sk->sk_type))
 997                         goto out;
 998         } else {
 999                 sock->state = SS_DISCONNECTING;
1000                 err = 0;
1001         }
1002
1003         /* Receive and send shutdowns are treated alike. */
1004         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
1005         if (mode) {
1006                 sk->sk_shutdown |= mode;
1007                 sk->sk_state_change(sk);
1008
1009                 if (sock_type_connectible(sk->sk_type)) {
1010                         sock_reset_flag(sk, SOCK_DONE);
1011                         vsock_send_shutdown(sk, mode);
1012                 }
1013         }
1014
1015 out:
1016         release_sock(sk);
1017         return err;
1018 }
1019
1020 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1021                                poll_table *wait)
1022 {
1023         struct sock *sk;
1024         __poll_t mask;
1025         struct vsock_sock *vsk;
1026
1027         sk = sock->sk;
1028         vsk = vsock_sk(sk);
1029
1030         poll_wait(file, sk_sleep(sk), wait);
1031         mask = 0;
1032
1033         if (sk->sk_err)
1034                 /* Signify that there has been an error on this socket. */
1035                 mask |= EPOLLERR;
1036
1037         /* INET sockets treat local write shutdown and peer write shutdown as a
1038          * case of EPOLLHUP set.
1039          */
1040         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1041             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1042              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1043                 mask |= EPOLLHUP;
1044         }
1045
1046         if (sk->sk_shutdown & RCV_SHUTDOWN ||
1047             vsk->peer_shutdown & SEND_SHUTDOWN) {
1048                 mask |= EPOLLRDHUP;
1049         }
1050
1051         if (sock->type == SOCK_DGRAM) {
1052                 /* For datagram sockets we can read if there is something in
1053                  * the queue and write as long as the socket isn't shutdown for
1054                  * sending.
1055                  */
1056                 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1057                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
1058                         mask |= EPOLLIN | EPOLLRDNORM;
1059                 }
1060
1061                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1062                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1063
1064         } else if (sock_type_connectible(sk->sk_type)) {
1065                 const struct vsock_transport *transport;
1066
1067                 lock_sock(sk);
1068
1069                 transport = vsk->transport;
1070
1071                 /* Listening sockets that have connections in their accept
1072                  * queue can be read.
1073                  */
1074                 if (sk->sk_state == TCP_LISTEN
1075                     && !vsock_is_accept_queue_empty(sk))
1076                         mask |= EPOLLIN | EPOLLRDNORM;
1077
1078                 /* If there is something in the queue then we can read. */
1079                 if (transport && transport->stream_is_active(vsk) &&
1080                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1081                         bool data_ready_now = false;
1082                         int target = sock_rcvlowat(sk, 0, INT_MAX);
1083                         int ret = transport->notify_poll_in(
1084                                         vsk, target, &data_ready_now);
1085                         if (ret < 0) {
1086                                 mask |= EPOLLERR;
1087                         } else {
1088                                 if (data_ready_now)
1089                                         mask |= EPOLLIN | EPOLLRDNORM;
1090
1091                         }
1092                 }
1093
1094                 /* Sockets whose connections have been closed, reset, or
1095                  * terminated should also be considered read, and we check the
1096                  * shutdown flag for that.
1097                  */
1098                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
1099                     vsk->peer_shutdown & SEND_SHUTDOWN) {
1100                         mask |= EPOLLIN | EPOLLRDNORM;
1101                 }
1102
1103                 /* Connected sockets that can produce data can be written. */
1104                 if (transport && sk->sk_state == TCP_ESTABLISHED) {
1105                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1106                                 bool space_avail_now = false;
1107                                 int ret = transport->notify_poll_out(
1108                                                 vsk, 1, &space_avail_now);
1109                                 if (ret < 0) {
1110                                         mask |= EPOLLERR;
1111                                 } else {
1112                                         if (space_avail_now)
1113                                                 /* Remove EPOLLWRBAND since INET
1114                                                  * sockets are not setting it.
1115                                                  */
1116                                                 mask |= EPOLLOUT | EPOLLWRNORM;
1117
1118                                 }
1119                         }
1120                 }
1121
1122                 /* Simulate INET socket poll behaviors, which sets
1123                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1124                  * but local send is not shutdown.
1125                  */
1126                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1127                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1128                                 mask |= EPOLLOUT | EPOLLWRNORM;
1129
1130                 }
1131
1132                 release_sock(sk);
1133         }
1134
1135         return mask;
1136 }
1137
1138 static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor)
1139 {
1140         struct vsock_sock *vsk = vsock_sk(sk);
1141
1142         return vsk->transport->read_skb(vsk, read_actor);
1143 }
1144
1145 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1146                                size_t len)
1147 {
1148         int err;
1149         struct sock *sk;
1150         struct vsock_sock *vsk;
1151         struct sockaddr_vm *remote_addr;
1152         const struct vsock_transport *transport;
1153
1154         if (msg->msg_flags & MSG_OOB)
1155                 return -EOPNOTSUPP;
1156
1157         /* For now, MSG_DONTWAIT is always assumed... */
1158         err = 0;
1159         sk = sock->sk;
1160         vsk = vsock_sk(sk);
1161
1162         lock_sock(sk);
1163
1164         transport = vsk->transport;
1165
1166         err = vsock_auto_bind(vsk);
1167         if (err)
1168                 goto out;
1169
1170
1171         /* If the provided message contains an address, use that.  Otherwise
1172          * fall back on the socket's remote handle (if it has been connected).
1173          */
1174         if (msg->msg_name &&
1175             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1176                             &remote_addr) == 0) {
1177                 /* Ensure this address is of the right type and is a valid
1178                  * destination.
1179                  */
1180
1181                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1182                         remote_addr->svm_cid = transport->get_local_cid();
1183
1184                 if (!vsock_addr_bound(remote_addr)) {
1185                         err = -EINVAL;
1186                         goto out;
1187                 }
1188         } else if (sock->state == SS_CONNECTED) {
1189                 remote_addr = &vsk->remote_addr;
1190
1191                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1192                         remote_addr->svm_cid = transport->get_local_cid();
1193
1194                 /* XXX Should connect() or this function ensure remote_addr is
1195                  * bound?
1196                  */
1197                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1198                         err = -EINVAL;
1199                         goto out;
1200                 }
1201         } else {
1202                 err = -EINVAL;
1203                 goto out;
1204         }
1205
1206         if (!transport->dgram_allow(remote_addr->svm_cid,
1207                                     remote_addr->svm_port)) {
1208                 err = -EINVAL;
1209                 goto out;
1210         }
1211
1212         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1213
1214 out:
1215         release_sock(sk);
1216         return err;
1217 }
1218
1219 static int vsock_dgram_connect(struct socket *sock,
1220                                struct sockaddr *addr, int addr_len, int flags)
1221 {
1222         int err;
1223         struct sock *sk;
1224         struct vsock_sock *vsk;
1225         struct sockaddr_vm *remote_addr;
1226
1227         sk = sock->sk;
1228         vsk = vsock_sk(sk);
1229
1230         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1231         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1232                 lock_sock(sk);
1233                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1234                                 VMADDR_PORT_ANY);
1235                 sock->state = SS_UNCONNECTED;
1236                 release_sock(sk);
1237                 return 0;
1238         } else if (err != 0)
1239                 return -EINVAL;
1240
1241         lock_sock(sk);
1242
1243         err = vsock_auto_bind(vsk);
1244         if (err)
1245                 goto out;
1246
1247         if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1248                                          remote_addr->svm_port)) {
1249                 err = -EINVAL;
1250                 goto out;
1251         }
1252
1253         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1254         sock->state = SS_CONNECTED;
1255
1256         /* sock map disallows redirection of non-TCP sockets with sk_state !=
1257          * TCP_ESTABLISHED (see sock_map_redirect_allowed()), so we set
1258          * TCP_ESTABLISHED here to allow redirection of connected vsock dgrams.
1259          *
1260          * This doesn't seem to be abnormal state for datagram sockets, as the
1261          * same approach can be see in other datagram socket types as well
1262          * (such as unix sockets).
1263          */
1264         sk->sk_state = TCP_ESTABLISHED;
1265
1266 out:
1267         release_sock(sk);
1268         return err;
1269 }
1270
1271 int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1272                         size_t len, int flags)
1273 {
1274 #ifdef CONFIG_BPF_SYSCALL
1275         const struct proto *prot;
1276 #endif
1277         struct vsock_sock *vsk;
1278         struct sock *sk;
1279
1280         sk = sock->sk;
1281         vsk = vsock_sk(sk);
1282
1283 #ifdef CONFIG_BPF_SYSCALL
1284         prot = READ_ONCE(sk->sk_prot);
1285         if (prot != &vsock_proto)
1286                 return prot->recvmsg(sk, msg, len, flags, NULL);
1287 #endif
1288
1289         return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1290 }
1291 EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
1292
1293 static const struct proto_ops vsock_dgram_ops = {
1294         .family = PF_VSOCK,
1295         .owner = THIS_MODULE,
1296         .release = vsock_release,
1297         .bind = vsock_bind,
1298         .connect = vsock_dgram_connect,
1299         .socketpair = sock_no_socketpair,
1300         .accept = sock_no_accept,
1301         .getname = vsock_getname,
1302         .poll = vsock_poll,
1303         .ioctl = sock_no_ioctl,
1304         .listen = sock_no_listen,
1305         .shutdown = vsock_shutdown,
1306         .sendmsg = vsock_dgram_sendmsg,
1307         .recvmsg = vsock_dgram_recvmsg,
1308         .mmap = sock_no_mmap,
1309         .read_skb = vsock_read_skb,
1310 };
1311
1312 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1313 {
1314         const struct vsock_transport *transport = vsk->transport;
1315
1316         if (!transport || !transport->cancel_pkt)
1317                 return -EOPNOTSUPP;
1318
1319         return transport->cancel_pkt(vsk);
1320 }
1321
1322 static void vsock_connect_timeout(struct work_struct *work)
1323 {
1324         struct sock *sk;
1325         struct vsock_sock *vsk;
1326
1327         vsk = container_of(work, struct vsock_sock, connect_work.work);
1328         sk = sk_vsock(vsk);
1329
1330         lock_sock(sk);
1331         if (sk->sk_state == TCP_SYN_SENT &&
1332             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1333                 sk->sk_state = TCP_CLOSE;
1334                 sk->sk_socket->state = SS_UNCONNECTED;
1335                 sk->sk_err = ETIMEDOUT;
1336                 sk_error_report(sk);
1337                 vsock_transport_cancel_pkt(vsk);
1338         }
1339         release_sock(sk);
1340
1341         sock_put(sk);
1342 }
1343
1344 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1345                          int addr_len, int flags)
1346 {
1347         int err;
1348         struct sock *sk;
1349         struct vsock_sock *vsk;
1350         const struct vsock_transport *transport;
1351         struct sockaddr_vm *remote_addr;
1352         long timeout;
1353         DEFINE_WAIT(wait);
1354
1355         err = 0;
1356         sk = sock->sk;
1357         vsk = vsock_sk(sk);
1358
1359         lock_sock(sk);
1360
1361         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1362         switch (sock->state) {
1363         case SS_CONNECTED:
1364                 err = -EISCONN;
1365                 goto out;
1366         case SS_DISCONNECTING:
1367                 err = -EINVAL;
1368                 goto out;
1369         case SS_CONNECTING:
1370                 /* This continues on so we can move sock into the SS_CONNECTED
1371                  * state once the connection has completed (at which point err
1372                  * will be set to zero also).  Otherwise, we will either wait
1373                  * for the connection or return -EALREADY should this be a
1374                  * non-blocking call.
1375                  */
1376                 err = -EALREADY;
1377                 if (flags & O_NONBLOCK)
1378                         goto out;
1379                 break;
1380         default:
1381                 if ((sk->sk_state == TCP_LISTEN) ||
1382                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1383                         err = -EINVAL;
1384                         goto out;
1385                 }
1386
1387                 /* Set the remote address that we are connecting to. */
1388                 memcpy(&vsk->remote_addr, remote_addr,
1389                        sizeof(vsk->remote_addr));
1390
1391                 err = vsock_assign_transport(vsk, NULL);
1392                 if (err)
1393                         goto out;
1394
1395                 transport = vsk->transport;
1396
1397                 /* The hypervisor and well-known contexts do not have socket
1398                  * endpoints.
1399                  */
1400                 if (!transport ||
1401                     !transport->stream_allow(remote_addr->svm_cid,
1402                                              remote_addr->svm_port)) {
1403                         err = -ENETUNREACH;
1404                         goto out;
1405                 }
1406
1407                 err = vsock_auto_bind(vsk);
1408                 if (err)
1409                         goto out;
1410
1411                 sk->sk_state = TCP_SYN_SENT;
1412
1413                 err = transport->connect(vsk);
1414                 if (err < 0)
1415                         goto out;
1416
1417                 /* Mark sock as connecting and set the error code to in
1418                  * progress in case this is a non-blocking connect.
1419                  */
1420                 sock->state = SS_CONNECTING;
1421                 err = -EINPROGRESS;
1422         }
1423
1424         /* The receive path will handle all communication until we are able to
1425          * enter the connected state.  Here we wait for the connection to be
1426          * completed or a notification of an error.
1427          */
1428         timeout = vsk->connect_timeout;
1429         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1430
1431         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1432                 if (flags & O_NONBLOCK) {
1433                         /* If we're not going to block, we schedule a timeout
1434                          * function to generate a timeout on the connection
1435                          * attempt, in case the peer doesn't respond in a
1436                          * timely manner. We hold on to the socket until the
1437                          * timeout fires.
1438                          */
1439                         sock_hold(sk);
1440
1441                         /* If the timeout function is already scheduled,
1442                          * reschedule it, then ungrab the socket refcount to
1443                          * keep it balanced.
1444                          */
1445                         if (mod_delayed_work(system_wq, &vsk->connect_work,
1446                                              timeout))
1447                                 sock_put(sk);
1448
1449                         /* Skip ahead to preserve error code set above. */
1450                         goto out_wait;
1451                 }
1452
1453                 release_sock(sk);
1454                 timeout = schedule_timeout(timeout);
1455                 lock_sock(sk);
1456
1457                 if (signal_pending(current)) {
1458                         err = sock_intr_errno(timeout);
1459                         sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1460                         sock->state = SS_UNCONNECTED;
1461                         vsock_transport_cancel_pkt(vsk);
1462                         vsock_remove_connected(vsk);
1463                         goto out_wait;
1464                 } else if ((sk->sk_state != TCP_ESTABLISHED) && (timeout == 0)) {
1465                         err = -ETIMEDOUT;
1466                         sk->sk_state = TCP_CLOSE;
1467                         sock->state = SS_UNCONNECTED;
1468                         vsock_transport_cancel_pkt(vsk);
1469                         goto out_wait;
1470                 }
1471
1472                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1473         }
1474
1475         if (sk->sk_err) {
1476                 err = -sk->sk_err;
1477                 sk->sk_state = TCP_CLOSE;
1478                 sock->state = SS_UNCONNECTED;
1479         } else {
1480                 err = 0;
1481         }
1482
1483 out_wait:
1484         finish_wait(sk_sleep(sk), &wait);
1485 out:
1486         release_sock(sk);
1487         return err;
1488 }
1489
1490 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1491                         bool kern)
1492 {
1493         struct sock *listener;
1494         int err;
1495         struct sock *connected;
1496         struct vsock_sock *vconnected;
1497         long timeout;
1498         DEFINE_WAIT(wait);
1499
1500         err = 0;
1501         listener = sock->sk;
1502
1503         lock_sock(listener);
1504
1505         if (!sock_type_connectible(sock->type)) {
1506                 err = -EOPNOTSUPP;
1507                 goto out;
1508         }
1509
1510         if (listener->sk_state != TCP_LISTEN) {
1511                 err = -EINVAL;
1512                 goto out;
1513         }
1514
1515         /* Wait for children sockets to appear; these are the new sockets
1516          * created upon connection establishment.
1517          */
1518         timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1519         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1520
1521         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1522                listener->sk_err == 0) {
1523                 release_sock(listener);
1524                 timeout = schedule_timeout(timeout);
1525                 finish_wait(sk_sleep(listener), &wait);
1526                 lock_sock(listener);
1527
1528                 if (signal_pending(current)) {
1529                         err = sock_intr_errno(timeout);
1530                         goto out;
1531                 } else if (timeout == 0) {
1532                         err = -EAGAIN;
1533                         goto out;
1534                 }
1535
1536                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1537         }
1538         finish_wait(sk_sleep(listener), &wait);
1539
1540         if (listener->sk_err)
1541                 err = -listener->sk_err;
1542
1543         if (connected) {
1544                 sk_acceptq_removed(listener);
1545
1546                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1547                 vconnected = vsock_sk(connected);
1548
1549                 /* If the listener socket has received an error, then we should
1550                  * reject this socket and return.  Note that we simply mark the
1551                  * socket rejected, drop our reference, and let the cleanup
1552                  * function handle the cleanup; the fact that we found it in
1553                  * the listener's accept queue guarantees that the cleanup
1554                  * function hasn't run yet.
1555                  */
1556                 if (err) {
1557                         vconnected->rejected = true;
1558                 } else {
1559                         newsock->state = SS_CONNECTED;
1560                         sock_graft(connected, newsock);
1561                 }
1562
1563                 release_sock(connected);
1564                 sock_put(connected);
1565         }
1566
1567 out:
1568         release_sock(listener);
1569         return err;
1570 }
1571
1572 static int vsock_listen(struct socket *sock, int backlog)
1573 {
1574         int err;
1575         struct sock *sk;
1576         struct vsock_sock *vsk;
1577
1578         sk = sock->sk;
1579
1580         lock_sock(sk);
1581
1582         if (!sock_type_connectible(sk->sk_type)) {
1583                 err = -EOPNOTSUPP;
1584                 goto out;
1585         }
1586
1587         if (sock->state != SS_UNCONNECTED) {
1588                 err = -EINVAL;
1589                 goto out;
1590         }
1591
1592         vsk = vsock_sk(sk);
1593
1594         if (!vsock_addr_bound(&vsk->local_addr)) {
1595                 err = -EINVAL;
1596                 goto out;
1597         }
1598
1599         sk->sk_max_ack_backlog = backlog;
1600         sk->sk_state = TCP_LISTEN;
1601
1602         err = 0;
1603
1604 out:
1605         release_sock(sk);
1606         return err;
1607 }
1608
1609 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1610                                      const struct vsock_transport *transport,
1611                                      u64 val)
1612 {
1613         if (val > vsk->buffer_max_size)
1614                 val = vsk->buffer_max_size;
1615
1616         if (val < vsk->buffer_min_size)
1617                 val = vsk->buffer_min_size;
1618
1619         if (val != vsk->buffer_size &&
1620             transport && transport->notify_buffer_size)
1621                 transport->notify_buffer_size(vsk, &val);
1622
1623         vsk->buffer_size = val;
1624 }
1625
1626 static int vsock_connectible_setsockopt(struct socket *sock,
1627                                         int level,
1628                                         int optname,
1629                                         sockptr_t optval,
1630                                         unsigned int optlen)
1631 {
1632         int err;
1633         struct sock *sk;
1634         struct vsock_sock *vsk;
1635         const struct vsock_transport *transport;
1636         u64 val;
1637
1638         if (level != AF_VSOCK)
1639                 return -ENOPROTOOPT;
1640
1641 #define COPY_IN(_v)                                       \
1642         do {                                              \
1643                 if (optlen < sizeof(_v)) {                \
1644                         err = -EINVAL;                    \
1645                         goto exit;                        \
1646                 }                                         \
1647                 if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {  \
1648                         err = -EFAULT;                                  \
1649                         goto exit;                                      \
1650                 }                                                       \
1651         } while (0)
1652
1653         err = 0;
1654         sk = sock->sk;
1655         vsk = vsock_sk(sk);
1656
1657         lock_sock(sk);
1658
1659         transport = vsk->transport;
1660
1661         switch (optname) {
1662         case SO_VM_SOCKETS_BUFFER_SIZE:
1663                 COPY_IN(val);
1664                 vsock_update_buffer_size(vsk, transport, val);
1665                 break;
1666
1667         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1668                 COPY_IN(val);
1669                 vsk->buffer_max_size = val;
1670                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1671                 break;
1672
1673         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1674                 COPY_IN(val);
1675                 vsk->buffer_min_size = val;
1676                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1677                 break;
1678
1679         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1680         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1681                 struct __kernel_sock_timeval tv;
1682
1683                 err = sock_copy_user_timeval(&tv, optval, optlen,
1684                                              optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1685                 if (err)
1686                         break;
1687                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1688                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1689                         vsk->connect_timeout = tv.tv_sec * HZ +
1690                                 DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1691                         if (vsk->connect_timeout == 0)
1692                                 vsk->connect_timeout =
1693                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1694
1695                 } else {
1696                         err = -ERANGE;
1697                 }
1698                 break;
1699         }
1700
1701         default:
1702                 err = -ENOPROTOOPT;
1703                 break;
1704         }
1705
1706 #undef COPY_IN
1707
1708 exit:
1709         release_sock(sk);
1710         return err;
1711 }
1712
1713 static int vsock_connectible_getsockopt(struct socket *sock,
1714                                         int level, int optname,
1715                                         char __user *optval,
1716                                         int __user *optlen)
1717 {
1718         struct sock *sk = sock->sk;
1719         struct vsock_sock *vsk = vsock_sk(sk);
1720
1721         union {
1722                 u64 val64;
1723                 struct old_timeval32 tm32;
1724                 struct __kernel_old_timeval tm;
1725                 struct  __kernel_sock_timeval stm;
1726         } v;
1727
1728         int lv = sizeof(v.val64);
1729         int len;
1730
1731         if (level != AF_VSOCK)
1732                 return -ENOPROTOOPT;
1733
1734         if (get_user(len, optlen))
1735                 return -EFAULT;
1736
1737         memset(&v, 0, sizeof(v));
1738
1739         switch (optname) {
1740         case SO_VM_SOCKETS_BUFFER_SIZE:
1741                 v.val64 = vsk->buffer_size;
1742                 break;
1743
1744         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1745                 v.val64 = vsk->buffer_max_size;
1746                 break;
1747
1748         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1749                 v.val64 = vsk->buffer_min_size;
1750                 break;
1751
1752         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1753         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1754                 lv = sock_get_timeout(vsk->connect_timeout, &v,
1755                                       optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1756                 break;
1757
1758         default:
1759                 return -ENOPROTOOPT;
1760         }
1761
1762         if (len < lv)
1763                 return -EINVAL;
1764         if (len > lv)
1765                 len = lv;
1766         if (copy_to_user(optval, &v, len))
1767                 return -EFAULT;
1768
1769         if (put_user(len, optlen))
1770                 return -EFAULT;
1771
1772         return 0;
1773 }
1774
1775 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1776                                      size_t len)
1777 {
1778         struct sock *sk;
1779         struct vsock_sock *vsk;
1780         const struct vsock_transport *transport;
1781         ssize_t total_written;
1782         long timeout;
1783         int err;
1784         struct vsock_transport_send_notify_data send_data;
1785         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1786
1787         sk = sock->sk;
1788         vsk = vsock_sk(sk);
1789         total_written = 0;
1790         err = 0;
1791
1792         if (msg->msg_flags & MSG_OOB)
1793                 return -EOPNOTSUPP;
1794
1795         lock_sock(sk);
1796
1797         transport = vsk->transport;
1798
1799         /* Callers should not provide a destination with connection oriented
1800          * sockets.
1801          */
1802         if (msg->msg_namelen) {
1803                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1804                 goto out;
1805         }
1806
1807         /* Send data only if both sides are not shutdown in the direction. */
1808         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1809             vsk->peer_shutdown & RCV_SHUTDOWN) {
1810                 err = -EPIPE;
1811                 goto out;
1812         }
1813
1814         if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1815             !vsock_addr_bound(&vsk->local_addr)) {
1816                 err = -ENOTCONN;
1817                 goto out;
1818         }
1819
1820         if (!vsock_addr_bound(&vsk->remote_addr)) {
1821                 err = -EDESTADDRREQ;
1822                 goto out;
1823         }
1824
1825         /* Wait for room in the produce queue to enqueue our user's data. */
1826         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1827
1828         err = transport->notify_send_init(vsk, &send_data);
1829         if (err < 0)
1830                 goto out;
1831
1832         while (total_written < len) {
1833                 ssize_t written;
1834
1835                 add_wait_queue(sk_sleep(sk), &wait);
1836                 while (vsock_stream_has_space(vsk) == 0 &&
1837                        sk->sk_err == 0 &&
1838                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1839                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1840
1841                         /* Don't wait for non-blocking sockets. */
1842                         if (timeout == 0) {
1843                                 err = -EAGAIN;
1844                                 remove_wait_queue(sk_sleep(sk), &wait);
1845                                 goto out_err;
1846                         }
1847
1848                         err = transport->notify_send_pre_block(vsk, &send_data);
1849                         if (err < 0) {
1850                                 remove_wait_queue(sk_sleep(sk), &wait);
1851                                 goto out_err;
1852                         }
1853
1854                         release_sock(sk);
1855                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1856                         lock_sock(sk);
1857                         if (signal_pending(current)) {
1858                                 err = sock_intr_errno(timeout);
1859                                 remove_wait_queue(sk_sleep(sk), &wait);
1860                                 goto out_err;
1861                         } else if (timeout == 0) {
1862                                 err = -EAGAIN;
1863                                 remove_wait_queue(sk_sleep(sk), &wait);
1864                                 goto out_err;
1865                         }
1866                 }
1867                 remove_wait_queue(sk_sleep(sk), &wait);
1868
1869                 /* These checks occur both as part of and after the loop
1870                  * conditional since we need to check before and after
1871                  * sleeping.
1872                  */
1873                 if (sk->sk_err) {
1874                         err = -sk->sk_err;
1875                         goto out_err;
1876                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1877                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1878                         err = -EPIPE;
1879                         goto out_err;
1880                 }
1881
1882                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1883                 if (err < 0)
1884                         goto out_err;
1885
1886                 /* Note that enqueue will only write as many bytes as are free
1887                  * in the produce queue, so we don't need to ensure len is
1888                  * smaller than the queue size.  It is the caller's
1889                  * responsibility to check how many bytes we were able to send.
1890                  */
1891
1892                 if (sk->sk_type == SOCK_SEQPACKET) {
1893                         written = transport->seqpacket_enqueue(vsk,
1894                                                 msg, len - total_written);
1895                 } else {
1896                         written = transport->stream_enqueue(vsk,
1897                                         msg, len - total_written);
1898                 }
1899
1900                 if (written < 0) {
1901                         err = written;
1902                         goto out_err;
1903                 }
1904
1905                 total_written += written;
1906
1907                 err = transport->notify_send_post_enqueue(
1908                                 vsk, written, &send_data);
1909                 if (err < 0)
1910                         goto out_err;
1911
1912         }
1913
1914 out_err:
1915         if (total_written > 0) {
1916                 /* Return number of written bytes only if:
1917                  * 1) SOCK_STREAM socket.
1918                  * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1919                  */
1920                 if (sk->sk_type == SOCK_STREAM || total_written == len)
1921                         err = total_written;
1922         }
1923 out:
1924         release_sock(sk);
1925         return err;
1926 }
1927
1928 static int vsock_connectible_wait_data(struct sock *sk,
1929                                        struct wait_queue_entry *wait,
1930                                        long timeout,
1931                                        struct vsock_transport_recv_notify_data *recv_data,
1932                                        size_t target)
1933 {
1934         const struct vsock_transport *transport;
1935         struct vsock_sock *vsk;
1936         s64 data;
1937         int err;
1938
1939         vsk = vsock_sk(sk);
1940         err = 0;
1941         transport = vsk->transport;
1942
1943         while (1) {
1944                 prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1945                 data = vsock_connectible_has_data(vsk);
1946                 if (data != 0)
1947                         break;
1948
1949                 if (sk->sk_err != 0 ||
1950                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1951                     (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1952                         break;
1953                 }
1954
1955                 /* Don't wait for non-blocking sockets. */
1956                 if (timeout == 0) {
1957                         err = -EAGAIN;
1958                         break;
1959                 }
1960
1961                 if (recv_data) {
1962                         err = transport->notify_recv_pre_block(vsk, target, recv_data);
1963                         if (err < 0)
1964                                 break;
1965                 }
1966
1967                 release_sock(sk);
1968                 timeout = schedule_timeout(timeout);
1969                 lock_sock(sk);
1970
1971                 if (signal_pending(current)) {
1972                         err = sock_intr_errno(timeout);
1973                         break;
1974                 } else if (timeout == 0) {
1975                         err = -EAGAIN;
1976                         break;
1977                 }
1978         }
1979
1980         finish_wait(sk_sleep(sk), wait);
1981
1982         if (err)
1983                 return err;
1984
1985         /* Internal transport error when checking for available
1986          * data. XXX This should be changed to a connection
1987          * reset in a later change.
1988          */
1989         if (data < 0)
1990                 return -ENOMEM;
1991
1992         return data;
1993 }
1994
1995 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1996                                   size_t len, int flags)
1997 {
1998         struct vsock_transport_recv_notify_data recv_data;
1999         const struct vsock_transport *transport;
2000         struct vsock_sock *vsk;
2001         ssize_t copied;
2002         size_t target;
2003         long timeout;
2004         int err;
2005
2006         DEFINE_WAIT(wait);
2007
2008         vsk = vsock_sk(sk);
2009         transport = vsk->transport;
2010
2011         /* We must not copy less than target bytes into the user's buffer
2012          * before returning successfully, so we wait for the consume queue to
2013          * have that much data to consume before dequeueing.  Note that this
2014          * makes it impossible to handle cases where target is greater than the
2015          * queue size.
2016          */
2017         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2018         if (target >= transport->stream_rcvhiwat(vsk)) {
2019                 err = -ENOMEM;
2020                 goto out;
2021         }
2022         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2023         copied = 0;
2024
2025         err = transport->notify_recv_init(vsk, target, &recv_data);
2026         if (err < 0)
2027                 goto out;
2028
2029
2030         while (1) {
2031                 ssize_t read;
2032
2033                 err = vsock_connectible_wait_data(sk, &wait, timeout,
2034                                                   &recv_data, target);
2035                 if (err <= 0)
2036                         break;
2037
2038                 err = transport->notify_recv_pre_dequeue(vsk, target,
2039                                                          &recv_data);
2040                 if (err < 0)
2041                         break;
2042
2043                 read = transport->stream_dequeue(vsk, msg, len - copied, flags);
2044                 if (read < 0) {
2045                         err = read;
2046                         break;
2047                 }
2048
2049                 copied += read;
2050
2051                 err = transport->notify_recv_post_dequeue(vsk, target, read,
2052                                                 !(flags & MSG_PEEK), &recv_data);
2053                 if (err < 0)
2054                         goto out;
2055
2056                 if (read >= target || flags & MSG_PEEK)
2057                         break;
2058
2059                 target -= read;
2060         }
2061
2062         if (sk->sk_err)
2063                 err = -sk->sk_err;
2064         else if (sk->sk_shutdown & RCV_SHUTDOWN)
2065                 err = 0;
2066
2067         if (copied > 0)
2068                 err = copied;
2069
2070 out:
2071         return err;
2072 }
2073
2074 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2075                                      size_t len, int flags)
2076 {
2077         const struct vsock_transport *transport;
2078         struct vsock_sock *vsk;
2079         ssize_t msg_len;
2080         long timeout;
2081         int err = 0;
2082         DEFINE_WAIT(wait);
2083
2084         vsk = vsock_sk(sk);
2085         transport = vsk->transport;
2086
2087         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2088
2089         err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2090         if (err <= 0)
2091                 goto out;
2092
2093         msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2094
2095         if (msg_len < 0) {
2096                 err = msg_len;
2097                 goto out;
2098         }
2099
2100         if (sk->sk_err) {
2101                 err = -sk->sk_err;
2102         } else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2103                 err = 0;
2104         } else {
2105                 /* User sets MSG_TRUNC, so return real length of
2106                  * packet.
2107                  */
2108                 if (flags & MSG_TRUNC)
2109                         err = msg_len;
2110                 else
2111                         err = len - msg_data_left(msg);
2112
2113                 /* Always set MSG_TRUNC if real length of packet is
2114                  * bigger than user's buffer.
2115                  */
2116                 if (msg_len > len)
2117                         msg->msg_flags |= MSG_TRUNC;
2118         }
2119
2120 out:
2121         return err;
2122 }
2123
2124 int
2125 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2126                           int flags)
2127 {
2128         struct sock *sk;
2129         struct vsock_sock *vsk;
2130         const struct vsock_transport *transport;
2131 #ifdef CONFIG_BPF_SYSCALL
2132         const struct proto *prot;
2133 #endif
2134         int err;
2135
2136         sk = sock->sk;
2137         vsk = vsock_sk(sk);
2138         err = 0;
2139
2140         lock_sock(sk);
2141
2142         transport = vsk->transport;
2143
2144         if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2145                 /* Recvmsg is supposed to return 0 if a peer performs an
2146                  * orderly shutdown. Differentiate between that case and when a
2147                  * peer has not connected or a local shutdown occurred with the
2148                  * SOCK_DONE flag.
2149                  */
2150                 if (sock_flag(sk, SOCK_DONE))
2151                         err = 0;
2152                 else
2153                         err = -ENOTCONN;
2154
2155                 goto out;
2156         }
2157
2158         if (flags & MSG_OOB) {
2159                 err = -EOPNOTSUPP;
2160                 goto out;
2161         }
2162
2163         /* We don't check peer_shutdown flag here since peer may actually shut
2164          * down, but there can be data in the queue that a local socket can
2165          * receive.
2166          */
2167         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2168                 err = 0;
2169                 goto out;
2170         }
2171
2172         /* It is valid on Linux to pass in a zero-length receive buffer.  This
2173          * is not an error.  We may as well bail out now.
2174          */
2175         if (!len) {
2176                 err = 0;
2177                 goto out;
2178         }
2179
2180 #ifdef CONFIG_BPF_SYSCALL
2181         prot = READ_ONCE(sk->sk_prot);
2182         if (prot != &vsock_proto) {
2183                 release_sock(sk);
2184                 return prot->recvmsg(sk, msg, len, flags, NULL);
2185         }
2186 #endif
2187
2188         if (sk->sk_type == SOCK_STREAM)
2189                 err = __vsock_stream_recvmsg(sk, msg, len, flags);
2190         else
2191                 err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2192
2193 out:
2194         release_sock(sk);
2195         return err;
2196 }
2197 EXPORT_SYMBOL_GPL(vsock_connectible_recvmsg);
2198
2199 static int vsock_set_rcvlowat(struct sock *sk, int val)
2200 {
2201         const struct vsock_transport *transport;
2202         struct vsock_sock *vsk;
2203
2204         vsk = vsock_sk(sk);
2205
2206         if (val > vsk->buffer_size)
2207                 return -EINVAL;
2208
2209         transport = vsk->transport;
2210
2211         if (transport && transport->set_rcvlowat)
2212                 return transport->set_rcvlowat(vsk, val);
2213
2214         WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
2215         return 0;
2216 }
2217
2218 static const struct proto_ops vsock_stream_ops = {
2219         .family = PF_VSOCK,
2220         .owner = THIS_MODULE,
2221         .release = vsock_release,
2222         .bind = vsock_bind,
2223         .connect = vsock_connect,
2224         .socketpair = sock_no_socketpair,
2225         .accept = vsock_accept,
2226         .getname = vsock_getname,
2227         .poll = vsock_poll,
2228         .ioctl = sock_no_ioctl,
2229         .listen = vsock_listen,
2230         .shutdown = vsock_shutdown,
2231         .setsockopt = vsock_connectible_setsockopt,
2232         .getsockopt = vsock_connectible_getsockopt,
2233         .sendmsg = vsock_connectible_sendmsg,
2234         .recvmsg = vsock_connectible_recvmsg,
2235         .mmap = sock_no_mmap,
2236         .set_rcvlowat = vsock_set_rcvlowat,
2237         .read_skb = vsock_read_skb,
2238 };
2239
2240 static const struct proto_ops vsock_seqpacket_ops = {
2241         .family = PF_VSOCK,
2242         .owner = THIS_MODULE,
2243         .release = vsock_release,
2244         .bind = vsock_bind,
2245         .connect = vsock_connect,
2246         .socketpair = sock_no_socketpair,
2247         .accept = vsock_accept,
2248         .getname = vsock_getname,
2249         .poll = vsock_poll,
2250         .ioctl = sock_no_ioctl,
2251         .listen = vsock_listen,
2252         .shutdown = vsock_shutdown,
2253         .setsockopt = vsock_connectible_setsockopt,
2254         .getsockopt = vsock_connectible_getsockopt,
2255         .sendmsg = vsock_connectible_sendmsg,
2256         .recvmsg = vsock_connectible_recvmsg,
2257         .mmap = sock_no_mmap,
2258         .read_skb = vsock_read_skb,
2259 };
2260
2261 static int vsock_create(struct net *net, struct socket *sock,
2262                         int protocol, int kern)
2263 {
2264         struct vsock_sock *vsk;
2265         struct sock *sk;
2266         int ret;
2267
2268         if (!sock)
2269                 return -EINVAL;
2270
2271         if (protocol && protocol != PF_VSOCK)
2272                 return -EPROTONOSUPPORT;
2273
2274         switch (sock->type) {
2275         case SOCK_DGRAM:
2276                 sock->ops = &vsock_dgram_ops;
2277                 break;
2278         case SOCK_STREAM:
2279                 sock->ops = &vsock_stream_ops;
2280                 break;
2281         case SOCK_SEQPACKET:
2282                 sock->ops = &vsock_seqpacket_ops;
2283                 break;
2284         default:
2285                 return -ESOCKTNOSUPPORT;
2286         }
2287
2288         sock->state = SS_UNCONNECTED;
2289
2290         sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2291         if (!sk)
2292                 return -ENOMEM;
2293
2294         vsk = vsock_sk(sk);
2295
2296         if (sock->type == SOCK_DGRAM) {
2297                 ret = vsock_assign_transport(vsk, NULL);
2298                 if (ret < 0) {
2299                         sock_put(sk);
2300                         return ret;
2301                 }
2302         }
2303
2304         vsock_insert_unbound(vsk);
2305
2306         return 0;
2307 }
2308
2309 static const struct net_proto_family vsock_family_ops = {
2310         .family = AF_VSOCK,
2311         .create = vsock_create,
2312         .owner = THIS_MODULE,
2313 };
2314
2315 static long vsock_dev_do_ioctl(struct file *filp,
2316                                unsigned int cmd, void __user *ptr)
2317 {
2318         u32 __user *p = ptr;
2319         u32 cid = VMADDR_CID_ANY;
2320         int retval = 0;
2321
2322         switch (cmd) {
2323         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2324                 /* To be compatible with the VMCI behavior, we prioritize the
2325                  * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2326                  */
2327                 if (transport_g2h)
2328                         cid = transport_g2h->get_local_cid();
2329                 else if (transport_h2g)
2330                         cid = transport_h2g->get_local_cid();
2331
2332                 if (put_user(cid, p) != 0)
2333                         retval = -EFAULT;
2334                 break;
2335
2336         default:
2337                 retval = -ENOIOCTLCMD;
2338         }
2339
2340         return retval;
2341 }
2342
2343 static long vsock_dev_ioctl(struct file *filp,
2344                             unsigned int cmd, unsigned long arg)
2345 {
2346         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2347 }
2348
2349 #ifdef CONFIG_COMPAT
2350 static long vsock_dev_compat_ioctl(struct file *filp,
2351                                    unsigned int cmd, unsigned long arg)
2352 {
2353         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2354 }
2355 #endif
2356
2357 static const struct file_operations vsock_device_ops = {
2358         .owner          = THIS_MODULE,
2359         .unlocked_ioctl = vsock_dev_ioctl,
2360 #ifdef CONFIG_COMPAT
2361         .compat_ioctl   = vsock_dev_compat_ioctl,
2362 #endif
2363         .open           = nonseekable_open,
2364 };
2365
2366 static struct miscdevice vsock_device = {
2367         .name           = "vsock",
2368         .fops           = &vsock_device_ops,
2369 };
2370
2371 static int __init vsock_init(void)
2372 {
2373         int err = 0;
2374
2375         vsock_init_tables();
2376
2377         vsock_proto.owner = THIS_MODULE;
2378         vsock_device.minor = MISC_DYNAMIC_MINOR;
2379         err = misc_register(&vsock_device);
2380         if (err) {
2381                 pr_err("Failed to register misc device\n");
2382                 goto err_reset_transport;
2383         }
2384
2385         err = proto_register(&vsock_proto, 1);  /* we want our slab */
2386         if (err) {
2387                 pr_err("Cannot register vsock protocol\n");
2388                 goto err_deregister_misc;
2389         }
2390
2391         err = sock_register(&vsock_family_ops);
2392         if (err) {
2393                 pr_err("could not register af_vsock (%d) address family: %d\n",
2394                        AF_VSOCK, err);
2395                 goto err_unregister_proto;
2396         }
2397
2398         vsock_bpf_build_proto();
2399
2400         return 0;
2401
2402 err_unregister_proto:
2403         proto_unregister(&vsock_proto);
2404 err_deregister_misc:
2405         misc_deregister(&vsock_device);
2406 err_reset_transport:
2407         return err;
2408 }
2409
2410 static void __exit vsock_exit(void)
2411 {
2412         misc_deregister(&vsock_device);
2413         sock_unregister(AF_VSOCK);
2414         proto_unregister(&vsock_proto);
2415 }
2416
2417 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2418 {
2419         return vsk->transport;
2420 }
2421 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2422
2423 int vsock_core_register(const struct vsock_transport *t, int features)
2424 {
2425         const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2426         int err = mutex_lock_interruptible(&vsock_register_mutex);
2427
2428         if (err)
2429                 return err;
2430
2431         t_h2g = transport_h2g;
2432         t_g2h = transport_g2h;
2433         t_dgram = transport_dgram;
2434         t_local = transport_local;
2435
2436         if (features & VSOCK_TRANSPORT_F_H2G) {
2437                 if (t_h2g) {
2438                         err = -EBUSY;
2439                         goto err_busy;
2440                 }
2441                 t_h2g = t;
2442         }
2443
2444         if (features & VSOCK_TRANSPORT_F_G2H) {
2445                 if (t_g2h) {
2446                         err = -EBUSY;
2447                         goto err_busy;
2448                 }
2449                 t_g2h = t;
2450         }
2451
2452         if (features & VSOCK_TRANSPORT_F_DGRAM) {
2453                 if (t_dgram) {
2454                         err = -EBUSY;
2455                         goto err_busy;
2456                 }
2457                 t_dgram = t;
2458         }
2459
2460         if (features & VSOCK_TRANSPORT_F_LOCAL) {
2461                 if (t_local) {
2462                         err = -EBUSY;
2463                         goto err_busy;
2464                 }
2465                 t_local = t;
2466         }
2467
2468         transport_h2g = t_h2g;
2469         transport_g2h = t_g2h;
2470         transport_dgram = t_dgram;
2471         transport_local = t_local;
2472
2473 err_busy:
2474         mutex_unlock(&vsock_register_mutex);
2475         return err;
2476 }
2477 EXPORT_SYMBOL_GPL(vsock_core_register);
2478
2479 void vsock_core_unregister(const struct vsock_transport *t)
2480 {
2481         mutex_lock(&vsock_register_mutex);
2482
2483         if (transport_h2g == t)
2484                 transport_h2g = NULL;
2485
2486         if (transport_g2h == t)
2487                 transport_g2h = NULL;
2488
2489         if (transport_dgram == t)
2490                 transport_dgram = NULL;
2491
2492         if (transport_local == t)
2493                 transport_local = NULL;
2494
2495         mutex_unlock(&vsock_register_mutex);
2496 }
2497 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2498
2499 module_init(vsock_init);
2500 module_exit(vsock_exit);
2501
2502 MODULE_AUTHOR("VMware, Inc.");
2503 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2504 MODULE_VERSION("1.0.2.0-k");
2505 MODULE_LICENSE("GPL v2");