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         .sendpage = sock_no_sendpage,
1310         .read_skb = vsock_read_skb,
1311 };
1312
1313 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1314 {
1315         const struct vsock_transport *transport = vsk->transport;
1316
1317         if (!transport || !transport->cancel_pkt)
1318                 return -EOPNOTSUPP;
1319
1320         return transport->cancel_pkt(vsk);
1321 }
1322
1323 static void vsock_connect_timeout(struct work_struct *work)
1324 {
1325         struct sock *sk;
1326         struct vsock_sock *vsk;
1327
1328         vsk = container_of(work, struct vsock_sock, connect_work.work);
1329         sk = sk_vsock(vsk);
1330
1331         lock_sock(sk);
1332         if (sk->sk_state == TCP_SYN_SENT &&
1333             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1334                 sk->sk_state = TCP_CLOSE;
1335                 sk->sk_socket->state = SS_UNCONNECTED;
1336                 sk->sk_err = ETIMEDOUT;
1337                 sk_error_report(sk);
1338                 vsock_transport_cancel_pkt(vsk);
1339         }
1340         release_sock(sk);
1341
1342         sock_put(sk);
1343 }
1344
1345 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1346                          int addr_len, int flags)
1347 {
1348         int err;
1349         struct sock *sk;
1350         struct vsock_sock *vsk;
1351         const struct vsock_transport *transport;
1352         struct sockaddr_vm *remote_addr;
1353         long timeout;
1354         DEFINE_WAIT(wait);
1355
1356         err = 0;
1357         sk = sock->sk;
1358         vsk = vsock_sk(sk);
1359
1360         lock_sock(sk);
1361
1362         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1363         switch (sock->state) {
1364         case SS_CONNECTED:
1365                 err = -EISCONN;
1366                 goto out;
1367         case SS_DISCONNECTING:
1368                 err = -EINVAL;
1369                 goto out;
1370         case SS_CONNECTING:
1371                 /* This continues on so we can move sock into the SS_CONNECTED
1372                  * state once the connection has completed (at which point err
1373                  * will be set to zero also).  Otherwise, we will either wait
1374                  * for the connection or return -EALREADY should this be a
1375                  * non-blocking call.
1376                  */
1377                 err = -EALREADY;
1378                 if (flags & O_NONBLOCK)
1379                         goto out;
1380                 break;
1381         default:
1382                 if ((sk->sk_state == TCP_LISTEN) ||
1383                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1384                         err = -EINVAL;
1385                         goto out;
1386                 }
1387
1388                 /* Set the remote address that we are connecting to. */
1389                 memcpy(&vsk->remote_addr, remote_addr,
1390                        sizeof(vsk->remote_addr));
1391
1392                 err = vsock_assign_transport(vsk, NULL);
1393                 if (err)
1394                         goto out;
1395
1396                 transport = vsk->transport;
1397
1398                 /* The hypervisor and well-known contexts do not have socket
1399                  * endpoints.
1400                  */
1401                 if (!transport ||
1402                     !transport->stream_allow(remote_addr->svm_cid,
1403                                              remote_addr->svm_port)) {
1404                         err = -ENETUNREACH;
1405                         goto out;
1406                 }
1407
1408                 err = vsock_auto_bind(vsk);
1409                 if (err)
1410                         goto out;
1411
1412                 sk->sk_state = TCP_SYN_SENT;
1413
1414                 err = transport->connect(vsk);
1415                 if (err < 0)
1416                         goto out;
1417
1418                 /* Mark sock as connecting and set the error code to in
1419                  * progress in case this is a non-blocking connect.
1420                  */
1421                 sock->state = SS_CONNECTING;
1422                 err = -EINPROGRESS;
1423         }
1424
1425         /* The receive path will handle all communication until we are able to
1426          * enter the connected state.  Here we wait for the connection to be
1427          * completed or a notification of an error.
1428          */
1429         timeout = vsk->connect_timeout;
1430         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1431
1432         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1433                 if (flags & O_NONBLOCK) {
1434                         /* If we're not going to block, we schedule a timeout
1435                          * function to generate a timeout on the connection
1436                          * attempt, in case the peer doesn't respond in a
1437                          * timely manner. We hold on to the socket until the
1438                          * timeout fires.
1439                          */
1440                         sock_hold(sk);
1441
1442                         /* If the timeout function is already scheduled,
1443                          * reschedule it, then ungrab the socket refcount to
1444                          * keep it balanced.
1445                          */
1446                         if (mod_delayed_work(system_wq, &vsk->connect_work,
1447                                              timeout))
1448                                 sock_put(sk);
1449
1450                         /* Skip ahead to preserve error code set above. */
1451                         goto out_wait;
1452                 }
1453
1454                 release_sock(sk);
1455                 timeout = schedule_timeout(timeout);
1456                 lock_sock(sk);
1457
1458                 if (signal_pending(current)) {
1459                         err = sock_intr_errno(timeout);
1460                         sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1461                         sock->state = SS_UNCONNECTED;
1462                         vsock_transport_cancel_pkt(vsk);
1463                         vsock_remove_connected(vsk);
1464                         goto out_wait;
1465                 } else if ((sk->sk_state != TCP_ESTABLISHED) && (timeout == 0)) {
1466                         err = -ETIMEDOUT;
1467                         sk->sk_state = TCP_CLOSE;
1468                         sock->state = SS_UNCONNECTED;
1469                         vsock_transport_cancel_pkt(vsk);
1470                         goto out_wait;
1471                 }
1472
1473                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1474         }
1475
1476         if (sk->sk_err) {
1477                 err = -sk->sk_err;
1478                 sk->sk_state = TCP_CLOSE;
1479                 sock->state = SS_UNCONNECTED;
1480         } else {
1481                 err = 0;
1482         }
1483
1484 out_wait:
1485         finish_wait(sk_sleep(sk), &wait);
1486 out:
1487         release_sock(sk);
1488         return err;
1489 }
1490
1491 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1492                         bool kern)
1493 {
1494         struct sock *listener;
1495         int err;
1496         struct sock *connected;
1497         struct vsock_sock *vconnected;
1498         long timeout;
1499         DEFINE_WAIT(wait);
1500
1501         err = 0;
1502         listener = sock->sk;
1503
1504         lock_sock(listener);
1505
1506         if (!sock_type_connectible(sock->type)) {
1507                 err = -EOPNOTSUPP;
1508                 goto out;
1509         }
1510
1511         if (listener->sk_state != TCP_LISTEN) {
1512                 err = -EINVAL;
1513                 goto out;
1514         }
1515
1516         /* Wait for children sockets to appear; these are the new sockets
1517          * created upon connection establishment.
1518          */
1519         timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1520         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1521
1522         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1523                listener->sk_err == 0) {
1524                 release_sock(listener);
1525                 timeout = schedule_timeout(timeout);
1526                 finish_wait(sk_sleep(listener), &wait);
1527                 lock_sock(listener);
1528
1529                 if (signal_pending(current)) {
1530                         err = sock_intr_errno(timeout);
1531                         goto out;
1532                 } else if (timeout == 0) {
1533                         err = -EAGAIN;
1534                         goto out;
1535                 }
1536
1537                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1538         }
1539         finish_wait(sk_sleep(listener), &wait);
1540
1541         if (listener->sk_err)
1542                 err = -listener->sk_err;
1543
1544         if (connected) {
1545                 sk_acceptq_removed(listener);
1546
1547                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1548                 vconnected = vsock_sk(connected);
1549
1550                 /* If the listener socket has received an error, then we should
1551                  * reject this socket and return.  Note that we simply mark the
1552                  * socket rejected, drop our reference, and let the cleanup
1553                  * function handle the cleanup; the fact that we found it in
1554                  * the listener's accept queue guarantees that the cleanup
1555                  * function hasn't run yet.
1556                  */
1557                 if (err) {
1558                         vconnected->rejected = true;
1559                 } else {
1560                         newsock->state = SS_CONNECTED;
1561                         sock_graft(connected, newsock);
1562                 }
1563
1564                 release_sock(connected);
1565                 sock_put(connected);
1566         }
1567
1568 out:
1569         release_sock(listener);
1570         return err;
1571 }
1572
1573 static int vsock_listen(struct socket *sock, int backlog)
1574 {
1575         int err;
1576         struct sock *sk;
1577         struct vsock_sock *vsk;
1578
1579         sk = sock->sk;
1580
1581         lock_sock(sk);
1582
1583         if (!sock_type_connectible(sk->sk_type)) {
1584                 err = -EOPNOTSUPP;
1585                 goto out;
1586         }
1587
1588         if (sock->state != SS_UNCONNECTED) {
1589                 err = -EINVAL;
1590                 goto out;
1591         }
1592
1593         vsk = vsock_sk(sk);
1594
1595         if (!vsock_addr_bound(&vsk->local_addr)) {
1596                 err = -EINVAL;
1597                 goto out;
1598         }
1599
1600         sk->sk_max_ack_backlog = backlog;
1601         sk->sk_state = TCP_LISTEN;
1602
1603         err = 0;
1604
1605 out:
1606         release_sock(sk);
1607         return err;
1608 }
1609
1610 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1611                                      const struct vsock_transport *transport,
1612                                      u64 val)
1613 {
1614         if (val > vsk->buffer_max_size)
1615                 val = vsk->buffer_max_size;
1616
1617         if (val < vsk->buffer_min_size)
1618                 val = vsk->buffer_min_size;
1619
1620         if (val != vsk->buffer_size &&
1621             transport && transport->notify_buffer_size)
1622                 transport->notify_buffer_size(vsk, &val);
1623
1624         vsk->buffer_size = val;
1625 }
1626
1627 static int vsock_connectible_setsockopt(struct socket *sock,
1628                                         int level,
1629                                         int optname,
1630                                         sockptr_t optval,
1631                                         unsigned int optlen)
1632 {
1633         int err;
1634         struct sock *sk;
1635         struct vsock_sock *vsk;
1636         const struct vsock_transport *transport;
1637         u64 val;
1638
1639         if (level != AF_VSOCK)
1640                 return -ENOPROTOOPT;
1641
1642 #define COPY_IN(_v)                                       \
1643         do {                                              \
1644                 if (optlen < sizeof(_v)) {                \
1645                         err = -EINVAL;                    \
1646                         goto exit;                        \
1647                 }                                         \
1648                 if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {  \
1649                         err = -EFAULT;                                  \
1650                         goto exit;                                      \
1651                 }                                                       \
1652         } while (0)
1653
1654         err = 0;
1655         sk = sock->sk;
1656         vsk = vsock_sk(sk);
1657
1658         lock_sock(sk);
1659
1660         transport = vsk->transport;
1661
1662         switch (optname) {
1663         case SO_VM_SOCKETS_BUFFER_SIZE:
1664                 COPY_IN(val);
1665                 vsock_update_buffer_size(vsk, transport, val);
1666                 break;
1667
1668         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1669                 COPY_IN(val);
1670                 vsk->buffer_max_size = val;
1671                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1672                 break;
1673
1674         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1675                 COPY_IN(val);
1676                 vsk->buffer_min_size = val;
1677                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1678                 break;
1679
1680         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1681         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1682                 struct __kernel_sock_timeval tv;
1683
1684                 err = sock_copy_user_timeval(&tv, optval, optlen,
1685                                              optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1686                 if (err)
1687                         break;
1688                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1689                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1690                         vsk->connect_timeout = tv.tv_sec * HZ +
1691                                 DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1692                         if (vsk->connect_timeout == 0)
1693                                 vsk->connect_timeout =
1694                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1695
1696                 } else {
1697                         err = -ERANGE;
1698                 }
1699                 break;
1700         }
1701
1702         default:
1703                 err = -ENOPROTOOPT;
1704                 break;
1705         }
1706
1707 #undef COPY_IN
1708
1709 exit:
1710         release_sock(sk);
1711         return err;
1712 }
1713
1714 static int vsock_connectible_getsockopt(struct socket *sock,
1715                                         int level, int optname,
1716                                         char __user *optval,
1717                                         int __user *optlen)
1718 {
1719         struct sock *sk = sock->sk;
1720         struct vsock_sock *vsk = vsock_sk(sk);
1721
1722         union {
1723                 u64 val64;
1724                 struct old_timeval32 tm32;
1725                 struct __kernel_old_timeval tm;
1726                 struct  __kernel_sock_timeval stm;
1727         } v;
1728
1729         int lv = sizeof(v.val64);
1730         int len;
1731
1732         if (level != AF_VSOCK)
1733                 return -ENOPROTOOPT;
1734
1735         if (get_user(len, optlen))
1736                 return -EFAULT;
1737
1738         memset(&v, 0, sizeof(v));
1739
1740         switch (optname) {
1741         case SO_VM_SOCKETS_BUFFER_SIZE:
1742                 v.val64 = vsk->buffer_size;
1743                 break;
1744
1745         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1746                 v.val64 = vsk->buffer_max_size;
1747                 break;
1748
1749         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1750                 v.val64 = vsk->buffer_min_size;
1751                 break;
1752
1753         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1754         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1755                 lv = sock_get_timeout(vsk->connect_timeout, &v,
1756                                       optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1757                 break;
1758
1759         default:
1760                 return -ENOPROTOOPT;
1761         }
1762
1763         if (len < lv)
1764                 return -EINVAL;
1765         if (len > lv)
1766                 len = lv;
1767         if (copy_to_user(optval, &v, len))
1768                 return -EFAULT;
1769
1770         if (put_user(len, optlen))
1771                 return -EFAULT;
1772
1773         return 0;
1774 }
1775
1776 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1777                                      size_t len)
1778 {
1779         struct sock *sk;
1780         struct vsock_sock *vsk;
1781         const struct vsock_transport *transport;
1782         ssize_t total_written;
1783         long timeout;
1784         int err;
1785         struct vsock_transport_send_notify_data send_data;
1786         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1787
1788         sk = sock->sk;
1789         vsk = vsock_sk(sk);
1790         total_written = 0;
1791         err = 0;
1792
1793         if (msg->msg_flags & MSG_OOB)
1794                 return -EOPNOTSUPP;
1795
1796         lock_sock(sk);
1797
1798         transport = vsk->transport;
1799
1800         /* Callers should not provide a destination with connection oriented
1801          * sockets.
1802          */
1803         if (msg->msg_namelen) {
1804                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1805                 goto out;
1806         }
1807
1808         /* Send data only if both sides are not shutdown in the direction. */
1809         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1810             vsk->peer_shutdown & RCV_SHUTDOWN) {
1811                 err = -EPIPE;
1812                 goto out;
1813         }
1814
1815         if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1816             !vsock_addr_bound(&vsk->local_addr)) {
1817                 err = -ENOTCONN;
1818                 goto out;
1819         }
1820
1821         if (!vsock_addr_bound(&vsk->remote_addr)) {
1822                 err = -EDESTADDRREQ;
1823                 goto out;
1824         }
1825
1826         /* Wait for room in the produce queue to enqueue our user's data. */
1827         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1828
1829         err = transport->notify_send_init(vsk, &send_data);
1830         if (err < 0)
1831                 goto out;
1832
1833         while (total_written < len) {
1834                 ssize_t written;
1835
1836                 add_wait_queue(sk_sleep(sk), &wait);
1837                 while (vsock_stream_has_space(vsk) == 0 &&
1838                        sk->sk_err == 0 &&
1839                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1840                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1841
1842                         /* Don't wait for non-blocking sockets. */
1843                         if (timeout == 0) {
1844                                 err = -EAGAIN;
1845                                 remove_wait_queue(sk_sleep(sk), &wait);
1846                                 goto out_err;
1847                         }
1848
1849                         err = transport->notify_send_pre_block(vsk, &send_data);
1850                         if (err < 0) {
1851                                 remove_wait_queue(sk_sleep(sk), &wait);
1852                                 goto out_err;
1853                         }
1854
1855                         release_sock(sk);
1856                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1857                         lock_sock(sk);
1858                         if (signal_pending(current)) {
1859                                 err = sock_intr_errno(timeout);
1860                                 remove_wait_queue(sk_sleep(sk), &wait);
1861                                 goto out_err;
1862                         } else if (timeout == 0) {
1863                                 err = -EAGAIN;
1864                                 remove_wait_queue(sk_sleep(sk), &wait);
1865                                 goto out_err;
1866                         }
1867                 }
1868                 remove_wait_queue(sk_sleep(sk), &wait);
1869
1870                 /* These checks occur both as part of and after the loop
1871                  * conditional since we need to check before and after
1872                  * sleeping.
1873                  */
1874                 if (sk->sk_err) {
1875                         err = -sk->sk_err;
1876                         goto out_err;
1877                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1878                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1879                         err = -EPIPE;
1880                         goto out_err;
1881                 }
1882
1883                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1884                 if (err < 0)
1885                         goto out_err;
1886
1887                 /* Note that enqueue will only write as many bytes as are free
1888                  * in the produce queue, so we don't need to ensure len is
1889                  * smaller than the queue size.  It is the caller's
1890                  * responsibility to check how many bytes we were able to send.
1891                  */
1892
1893                 if (sk->sk_type == SOCK_SEQPACKET) {
1894                         written = transport->seqpacket_enqueue(vsk,
1895                                                 msg, len - total_written);
1896                 } else {
1897                         written = transport->stream_enqueue(vsk,
1898                                         msg, len - total_written);
1899                 }
1900
1901                 if (written < 0) {
1902                         err = written;
1903                         goto out_err;
1904                 }
1905
1906                 total_written += written;
1907
1908                 err = transport->notify_send_post_enqueue(
1909                                 vsk, written, &send_data);
1910                 if (err < 0)
1911                         goto out_err;
1912
1913         }
1914
1915 out_err:
1916         if (total_written > 0) {
1917                 /* Return number of written bytes only if:
1918                  * 1) SOCK_STREAM socket.
1919                  * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1920                  */
1921                 if (sk->sk_type == SOCK_STREAM || total_written == len)
1922                         err = total_written;
1923         }
1924 out:
1925         release_sock(sk);
1926         return err;
1927 }
1928
1929 static int vsock_connectible_wait_data(struct sock *sk,
1930                                        struct wait_queue_entry *wait,
1931                                        long timeout,
1932                                        struct vsock_transport_recv_notify_data *recv_data,
1933                                        size_t target)
1934 {
1935         const struct vsock_transport *transport;
1936         struct vsock_sock *vsk;
1937         s64 data;
1938         int err;
1939
1940         vsk = vsock_sk(sk);
1941         err = 0;
1942         transport = vsk->transport;
1943
1944         while (1) {
1945                 prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1946                 data = vsock_connectible_has_data(vsk);
1947                 if (data != 0)
1948                         break;
1949
1950                 if (sk->sk_err != 0 ||
1951                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1952                     (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1953                         break;
1954                 }
1955
1956                 /* Don't wait for non-blocking sockets. */
1957                 if (timeout == 0) {
1958                         err = -EAGAIN;
1959                         break;
1960                 }
1961
1962                 if (recv_data) {
1963                         err = transport->notify_recv_pre_block(vsk, target, recv_data);
1964                         if (err < 0)
1965                                 break;
1966                 }
1967
1968                 release_sock(sk);
1969                 timeout = schedule_timeout(timeout);
1970                 lock_sock(sk);
1971
1972                 if (signal_pending(current)) {
1973                         err = sock_intr_errno(timeout);
1974                         break;
1975                 } else if (timeout == 0) {
1976                         err = -EAGAIN;
1977                         break;
1978                 }
1979         }
1980
1981         finish_wait(sk_sleep(sk), wait);
1982
1983         if (err)
1984                 return err;
1985
1986         /* Internal transport error when checking for available
1987          * data. XXX This should be changed to a connection
1988          * reset in a later change.
1989          */
1990         if (data < 0)
1991                 return -ENOMEM;
1992
1993         return data;
1994 }
1995
1996 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1997                                   size_t len, int flags)
1998 {
1999         struct vsock_transport_recv_notify_data recv_data;
2000         const struct vsock_transport *transport;
2001         struct vsock_sock *vsk;
2002         ssize_t copied;
2003         size_t target;
2004         long timeout;
2005         int err;
2006
2007         DEFINE_WAIT(wait);
2008
2009         vsk = vsock_sk(sk);
2010         transport = vsk->transport;
2011
2012         /* We must not copy less than target bytes into the user's buffer
2013          * before returning successfully, so we wait for the consume queue to
2014          * have that much data to consume before dequeueing.  Note that this
2015          * makes it impossible to handle cases where target is greater than the
2016          * queue size.
2017          */
2018         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2019         if (target >= transport->stream_rcvhiwat(vsk)) {
2020                 err = -ENOMEM;
2021                 goto out;
2022         }
2023         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2024         copied = 0;
2025
2026         err = transport->notify_recv_init(vsk, target, &recv_data);
2027         if (err < 0)
2028                 goto out;
2029
2030
2031         while (1) {
2032                 ssize_t read;
2033
2034                 err = vsock_connectible_wait_data(sk, &wait, timeout,
2035                                                   &recv_data, target);
2036                 if (err <= 0)
2037                         break;
2038
2039                 err = transport->notify_recv_pre_dequeue(vsk, target,
2040                                                          &recv_data);
2041                 if (err < 0)
2042                         break;
2043
2044                 read = transport->stream_dequeue(vsk, msg, len - copied, flags);
2045                 if (read < 0) {
2046                         err = read;
2047                         break;
2048                 }
2049
2050                 copied += read;
2051
2052                 err = transport->notify_recv_post_dequeue(vsk, target, read,
2053                                                 !(flags & MSG_PEEK), &recv_data);
2054                 if (err < 0)
2055                         goto out;
2056
2057                 if (read >= target || flags & MSG_PEEK)
2058                         break;
2059
2060                 target -= read;
2061         }
2062
2063         if (sk->sk_err)
2064                 err = -sk->sk_err;
2065         else if (sk->sk_shutdown & RCV_SHUTDOWN)
2066                 err = 0;
2067
2068         if (copied > 0)
2069                 err = copied;
2070
2071 out:
2072         return err;
2073 }
2074
2075 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2076                                      size_t len, int flags)
2077 {
2078         const struct vsock_transport *transport;
2079         struct vsock_sock *vsk;
2080         ssize_t msg_len;
2081         long timeout;
2082         int err = 0;
2083         DEFINE_WAIT(wait);
2084
2085         vsk = vsock_sk(sk);
2086         transport = vsk->transport;
2087
2088         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2089
2090         err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2091         if (err <= 0)
2092                 goto out;
2093
2094         msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2095
2096         if (msg_len < 0) {
2097                 err = msg_len;
2098                 goto out;
2099         }
2100
2101         if (sk->sk_err) {
2102                 err = -sk->sk_err;
2103         } else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2104                 err = 0;
2105         } else {
2106                 /* User sets MSG_TRUNC, so return real length of
2107                  * packet.
2108                  */
2109                 if (flags & MSG_TRUNC)
2110                         err = msg_len;
2111                 else
2112                         err = len - msg_data_left(msg);
2113
2114                 /* Always set MSG_TRUNC if real length of packet is
2115                  * bigger than user's buffer.
2116                  */
2117                 if (msg_len > len)
2118                         msg->msg_flags |= MSG_TRUNC;
2119         }
2120
2121 out:
2122         return err;
2123 }
2124
2125 int
2126 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2127                           int flags)
2128 {
2129         struct sock *sk;
2130         struct vsock_sock *vsk;
2131         const struct vsock_transport *transport;
2132 #ifdef CONFIG_BPF_SYSCALL
2133         const struct proto *prot;
2134 #endif
2135         int err;
2136
2137         sk = sock->sk;
2138         vsk = vsock_sk(sk);
2139         err = 0;
2140
2141         lock_sock(sk);
2142
2143         transport = vsk->transport;
2144
2145         if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2146                 /* Recvmsg is supposed to return 0 if a peer performs an
2147                  * orderly shutdown. Differentiate between that case and when a
2148                  * peer has not connected or a local shutdown occurred with the
2149                  * SOCK_DONE flag.
2150                  */
2151                 if (sock_flag(sk, SOCK_DONE))
2152                         err = 0;
2153                 else
2154                         err = -ENOTCONN;
2155
2156                 goto out;
2157         }
2158
2159         if (flags & MSG_OOB) {
2160                 err = -EOPNOTSUPP;
2161                 goto out;
2162         }
2163
2164         /* We don't check peer_shutdown flag here since peer may actually shut
2165          * down, but there can be data in the queue that a local socket can
2166          * receive.
2167          */
2168         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2169                 err = 0;
2170                 goto out;
2171         }
2172
2173         /* It is valid on Linux to pass in a zero-length receive buffer.  This
2174          * is not an error.  We may as well bail out now.
2175          */
2176         if (!len) {
2177                 err = 0;
2178                 goto out;
2179         }
2180
2181 #ifdef CONFIG_BPF_SYSCALL
2182         prot = READ_ONCE(sk->sk_prot);
2183         if (prot != &vsock_proto) {
2184                 release_sock(sk);
2185                 return prot->recvmsg(sk, msg, len, flags, NULL);
2186         }
2187 #endif
2188
2189         if (sk->sk_type == SOCK_STREAM)
2190                 err = __vsock_stream_recvmsg(sk, msg, len, flags);
2191         else
2192                 err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2193
2194 out:
2195         release_sock(sk);
2196         return err;
2197 }
2198 EXPORT_SYMBOL_GPL(vsock_connectible_recvmsg);
2199
2200 static int vsock_set_rcvlowat(struct sock *sk, int val)
2201 {
2202         const struct vsock_transport *transport;
2203         struct vsock_sock *vsk;
2204
2205         vsk = vsock_sk(sk);
2206
2207         if (val > vsk->buffer_size)
2208                 return -EINVAL;
2209
2210         transport = vsk->transport;
2211
2212         if (transport && transport->set_rcvlowat)
2213                 return transport->set_rcvlowat(vsk, val);
2214
2215         WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
2216         return 0;
2217 }
2218
2219 static const struct proto_ops vsock_stream_ops = {
2220         .family = PF_VSOCK,
2221         .owner = THIS_MODULE,
2222         .release = vsock_release,
2223         .bind = vsock_bind,
2224         .connect = vsock_connect,
2225         .socketpair = sock_no_socketpair,
2226         .accept = vsock_accept,
2227         .getname = vsock_getname,
2228         .poll = vsock_poll,
2229         .ioctl = sock_no_ioctl,
2230         .listen = vsock_listen,
2231         .shutdown = vsock_shutdown,
2232         .setsockopt = vsock_connectible_setsockopt,
2233         .getsockopt = vsock_connectible_getsockopt,
2234         .sendmsg = vsock_connectible_sendmsg,
2235         .recvmsg = vsock_connectible_recvmsg,
2236         .mmap = sock_no_mmap,
2237         .sendpage = sock_no_sendpage,
2238         .set_rcvlowat = vsock_set_rcvlowat,
2239         .read_skb = vsock_read_skb,
2240 };
2241
2242 static const struct proto_ops vsock_seqpacket_ops = {
2243         .family = PF_VSOCK,
2244         .owner = THIS_MODULE,
2245         .release = vsock_release,
2246         .bind = vsock_bind,
2247         .connect = vsock_connect,
2248         .socketpair = sock_no_socketpair,
2249         .accept = vsock_accept,
2250         .getname = vsock_getname,
2251         .poll = vsock_poll,
2252         .ioctl = sock_no_ioctl,
2253         .listen = vsock_listen,
2254         .shutdown = vsock_shutdown,
2255         .setsockopt = vsock_connectible_setsockopt,
2256         .getsockopt = vsock_connectible_getsockopt,
2257         .sendmsg = vsock_connectible_sendmsg,
2258         .recvmsg = vsock_connectible_recvmsg,
2259         .mmap = sock_no_mmap,
2260         .sendpage = sock_no_sendpage,
2261         .read_skb = vsock_read_skb,
2262 };
2263
2264 static int vsock_create(struct net *net, struct socket *sock,
2265                         int protocol, int kern)
2266 {
2267         struct vsock_sock *vsk;
2268         struct sock *sk;
2269         int ret;
2270
2271         if (!sock)
2272                 return -EINVAL;
2273
2274         if (protocol && protocol != PF_VSOCK)
2275                 return -EPROTONOSUPPORT;
2276
2277         switch (sock->type) {
2278         case SOCK_DGRAM:
2279                 sock->ops = &vsock_dgram_ops;
2280                 break;
2281         case SOCK_STREAM:
2282                 sock->ops = &vsock_stream_ops;
2283                 break;
2284         case SOCK_SEQPACKET:
2285                 sock->ops = &vsock_seqpacket_ops;
2286                 break;
2287         default:
2288                 return -ESOCKTNOSUPPORT;
2289         }
2290
2291         sock->state = SS_UNCONNECTED;
2292
2293         sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2294         if (!sk)
2295                 return -ENOMEM;
2296
2297         vsk = vsock_sk(sk);
2298
2299         if (sock->type == SOCK_DGRAM) {
2300                 ret = vsock_assign_transport(vsk, NULL);
2301                 if (ret < 0) {
2302                         sock_put(sk);
2303                         return ret;
2304                 }
2305         }
2306
2307         vsock_insert_unbound(vsk);
2308
2309         return 0;
2310 }
2311
2312 static const struct net_proto_family vsock_family_ops = {
2313         .family = AF_VSOCK,
2314         .create = vsock_create,
2315         .owner = THIS_MODULE,
2316 };
2317
2318 static long vsock_dev_do_ioctl(struct file *filp,
2319                                unsigned int cmd, void __user *ptr)
2320 {
2321         u32 __user *p = ptr;
2322         u32 cid = VMADDR_CID_ANY;
2323         int retval = 0;
2324
2325         switch (cmd) {
2326         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2327                 /* To be compatible with the VMCI behavior, we prioritize the
2328                  * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2329                  */
2330                 if (transport_g2h)
2331                         cid = transport_g2h->get_local_cid();
2332                 else if (transport_h2g)
2333                         cid = transport_h2g->get_local_cid();
2334
2335                 if (put_user(cid, p) != 0)
2336                         retval = -EFAULT;
2337                 break;
2338
2339         default:
2340                 retval = -ENOIOCTLCMD;
2341         }
2342
2343         return retval;
2344 }
2345
2346 static long vsock_dev_ioctl(struct file *filp,
2347                             unsigned int cmd, unsigned long arg)
2348 {
2349         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2350 }
2351
2352 #ifdef CONFIG_COMPAT
2353 static long vsock_dev_compat_ioctl(struct file *filp,
2354                                    unsigned int cmd, unsigned long arg)
2355 {
2356         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2357 }
2358 #endif
2359
2360 static const struct file_operations vsock_device_ops = {
2361         .owner          = THIS_MODULE,
2362         .unlocked_ioctl = vsock_dev_ioctl,
2363 #ifdef CONFIG_COMPAT
2364         .compat_ioctl   = vsock_dev_compat_ioctl,
2365 #endif
2366         .open           = nonseekable_open,
2367 };
2368
2369 static struct miscdevice vsock_device = {
2370         .name           = "vsock",
2371         .fops           = &vsock_device_ops,
2372 };
2373
2374 static int __init vsock_init(void)
2375 {
2376         int err = 0;
2377
2378         vsock_init_tables();
2379
2380         vsock_proto.owner = THIS_MODULE;
2381         vsock_device.minor = MISC_DYNAMIC_MINOR;
2382         err = misc_register(&vsock_device);
2383         if (err) {
2384                 pr_err("Failed to register misc device\n");
2385                 goto err_reset_transport;
2386         }
2387
2388         err = proto_register(&vsock_proto, 1);  /* we want our slab */
2389         if (err) {
2390                 pr_err("Cannot register vsock protocol\n");
2391                 goto err_deregister_misc;
2392         }
2393
2394         err = sock_register(&vsock_family_ops);
2395         if (err) {
2396                 pr_err("could not register af_vsock (%d) address family: %d\n",
2397                        AF_VSOCK, err);
2398                 goto err_unregister_proto;
2399         }
2400
2401         vsock_bpf_build_proto();
2402
2403         return 0;
2404
2405 err_unregister_proto:
2406         proto_unregister(&vsock_proto);
2407 err_deregister_misc:
2408         misc_deregister(&vsock_device);
2409 err_reset_transport:
2410         return err;
2411 }
2412
2413 static void __exit vsock_exit(void)
2414 {
2415         misc_deregister(&vsock_device);
2416         sock_unregister(AF_VSOCK);
2417         proto_unregister(&vsock_proto);
2418 }
2419
2420 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2421 {
2422         return vsk->transport;
2423 }
2424 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2425
2426 int vsock_core_register(const struct vsock_transport *t, int features)
2427 {
2428         const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2429         int err = mutex_lock_interruptible(&vsock_register_mutex);
2430
2431         if (err)
2432                 return err;
2433
2434         t_h2g = transport_h2g;
2435         t_g2h = transport_g2h;
2436         t_dgram = transport_dgram;
2437         t_local = transport_local;
2438
2439         if (features & VSOCK_TRANSPORT_F_H2G) {
2440                 if (t_h2g) {
2441                         err = -EBUSY;
2442                         goto err_busy;
2443                 }
2444                 t_h2g = t;
2445         }
2446
2447         if (features & VSOCK_TRANSPORT_F_G2H) {
2448                 if (t_g2h) {
2449                         err = -EBUSY;
2450                         goto err_busy;
2451                 }
2452                 t_g2h = t;
2453         }
2454
2455         if (features & VSOCK_TRANSPORT_F_DGRAM) {
2456                 if (t_dgram) {
2457                         err = -EBUSY;
2458                         goto err_busy;
2459                 }
2460                 t_dgram = t;
2461         }
2462
2463         if (features & VSOCK_TRANSPORT_F_LOCAL) {
2464                 if (t_local) {
2465                         err = -EBUSY;
2466                         goto err_busy;
2467                 }
2468                 t_local = t;
2469         }
2470
2471         transport_h2g = t_h2g;
2472         transport_g2h = t_g2h;
2473         transport_dgram = t_dgram;
2474         transport_local = t_local;
2475
2476 err_busy:
2477         mutex_unlock(&vsock_register_mutex);
2478         return err;
2479 }
2480 EXPORT_SYMBOL_GPL(vsock_core_register);
2481
2482 void vsock_core_unregister(const struct vsock_transport *t)
2483 {
2484         mutex_lock(&vsock_register_mutex);
2485
2486         if (transport_h2g == t)
2487                 transport_h2g = NULL;
2488
2489         if (transport_g2h == t)
2490                 transport_g2h = NULL;
2491
2492         if (transport_dgram == t)
2493                 transport_dgram = NULL;
2494
2495         if (transport_local == t)
2496                 transport_local = NULL;
2497
2498         mutex_unlock(&vsock_register_mutex);
2499 }
2500 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2501
2502 module_init(vsock_init);
2503 module_exit(vsock_exit);
2504
2505 MODULE_AUTHOR("VMware, Inc.");
2506 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2507 MODULE_VERSION("1.0.2.0-k");
2508 MODULE_LICENSE("GPL v2");