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/errqueue.h>
  93 #include <linux/init.h>
  94 #include <linux/io.h>
  95 #include <linux/kernel.h>
  96 #include <linux/sched/signal.h>
  97 #include <linux/kmod.h>
  98 #include <linux/list.h>
  99 #include <linux/miscdevice.h>
 100 #include <linux/module.h>
 101 #include <linux/mutex.h>
 102 #include <linux/net.h>
 103 #include <linux/poll.h>
 104 #include <linux/random.h>
 105 #include <linux/skbuff.h>
 106 #include <linux/smp.h>
 107 #include <linux/socket.h>
 108 #include <linux/stddef.h>
 109 #include <linux/unistd.h>
 110 #include <linux/wait.h>
 111 #include <linux/workqueue.h>
 112 #include <net/sock.h>
 113 #include <net/af_vsock.h>
 114 #include <uapi/linux/vm_sockets.h>
 115
 116 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 117 static void vsock_sk_destruct(struct sock *sk);
 118 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 119
 120 /* Protocol family. */
 121 struct proto vsock_proto = {
 122         .name = "AF_VSOCK",
 123         .owner = THIS_MODULE,
 124         .obj_size = sizeof(struct vsock_sock),
 125 #ifdef CONFIG_BPF_SYSCALL
 126         .psock_update_sk_prot = vsock_bpf_update_proto,
 127 #endif
 128 };
 129
 130 /* The default peer timeout indicates how long we will wait for a peer response
 131  * to a control message.
 132  */
 133 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
 134
 135 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
 136 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
 137 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
 138
 139 /* Transport used for host->guest communication */
 140 static const struct vsock_transport *transport_h2g;
 141 /* Transport used for guest->host communication */
 142 static const struct vsock_transport *transport_g2h;
 143 /* Transport used for DGRAM communication */
 144 static const struct vsock_transport *transport_dgram;
 145 /* Transport used for local communication */
 146 static const struct vsock_transport *transport_local;
 147 static DEFINE_MUTEX(vsock_register_mutex);
 148
 149 /**** UTILS ****/
 150
 151 /* Each bound VSocket is stored in the bind hash table and each connected
 152  * VSocket is stored in the connected hash table.
 153  *
 154  * Unbound sockets are all put on the same list attached to the end of the hash
 155  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
 156  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
 157  * represents the list that addr hashes to).
 158  *
 159  * Specifically, we initialize the vsock_bind_table array to a size of
 160  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
 161  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
 162  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
 163  * mods with VSOCK_HASH_SIZE to ensure this.
 164  */
 165 #define MAX_PORT_RETRIES        24
 166
 167 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
 168 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
 169 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
 170
 171 /* XXX This can probably be implemented in a better way. */
 172 #define VSOCK_CONN_HASH(src, dst)                               \
 173         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
 174 #define vsock_connected_sockets(src, dst)               \
 175         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
 176 #define vsock_connected_sockets_vsk(vsk)                                \
 177         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
 178
 179 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
 180 EXPORT_SYMBOL_GPL(vsock_bind_table);
 181 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
 182 EXPORT_SYMBOL_GPL(vsock_connected_table);
 183 DEFINE_SPINLOCK(vsock_table_lock);
 184 EXPORT_SYMBOL_GPL(vsock_table_lock);
 185
 186 /* Autobind this socket to the local address if necessary. */
 187 static int vsock_auto_bind(struct vsock_sock *vsk)
 188 {
 189         struct sock *sk = sk_vsock(vsk);
 190         struct sockaddr_vm local_addr;
 191
 192         if (vsock_addr_bound(&vsk->local_addr))
 193                 return 0;
 194         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 195         return __vsock_bind(sk, &local_addr);
 196 }
 197
 198 static void vsock_init_tables(void)
 199 {
 200         int i;
 201
 202         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
 203                 INIT_LIST_HEAD(&vsock_bind_table[i]);
 204
 205         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
 206                 INIT_LIST_HEAD(&vsock_connected_table[i]);
 207 }
 208
 209 static void __vsock_insert_bound(struct list_head *list,
 210                                  struct vsock_sock *vsk)
 211 {
 212         sock_hold(&vsk->sk);
 213         list_add(&vsk->bound_table, list);
 214 }
 215
 216 static void __vsock_insert_connected(struct list_head *list,
 217                                      struct vsock_sock *vsk)
 218 {
 219         sock_hold(&vsk->sk);
 220         list_add(&vsk->connected_table, list);
 221 }
 222
 223 static void __vsock_remove_bound(struct vsock_sock *vsk)
 224 {
 225         list_del_init(&vsk->bound_table);
 226         sock_put(&vsk->sk);
 227 }
 228
 229 static void __vsock_remove_connected(struct vsock_sock *vsk)
 230 {
 231         list_del_init(&vsk->connected_table);
 232         sock_put(&vsk->sk);
 233 }
 234
 235 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
 236 {
 237         struct vsock_sock *vsk;
 238
 239         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
 240                 if (vsock_addr_equals_addr(addr, &vsk->local_addr))
 241                         return sk_vsock(vsk);
 242
 243                 if (addr->svm_port == vsk->local_addr.svm_port &&
 244                     (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
 245                      addr->svm_cid == VMADDR_CID_ANY))
 246                         return sk_vsock(vsk);
 247         }
 248
 249         return NULL;
 250 }
 251
 252 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
 253                                                   struct sockaddr_vm *dst)
 254 {
 255         struct vsock_sock *vsk;
 256
 257         list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
 258                             connected_table) {
 259                 if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
 260                     dst->svm_port == vsk->local_addr.svm_port) {
 261                         return sk_vsock(vsk);
 262                 }
 263         }
 264
 265         return NULL;
 266 }
 267
 268 static void vsock_insert_unbound(struct vsock_sock *vsk)
 269 {
 270         spin_lock_bh(&vsock_table_lock);
 271         __vsock_insert_bound(vsock_unbound_sockets, vsk);
 272         spin_unlock_bh(&vsock_table_lock);
 273 }
 274
 275 void vsock_insert_connected(struct vsock_sock *vsk)
 276 {
 277         struct list_head *list = vsock_connected_sockets(
 278                 &vsk->remote_addr, &vsk->local_addr);
 279
 280         spin_lock_bh(&vsock_table_lock);
 281         __vsock_insert_connected(list, vsk);
 282         spin_unlock_bh(&vsock_table_lock);
 283 }
 284 EXPORT_SYMBOL_GPL(vsock_insert_connected);
 285
 286 void vsock_remove_bound(struct vsock_sock *vsk)
 287 {
 288         spin_lock_bh(&vsock_table_lock);
 289         if (__vsock_in_bound_table(vsk))
 290                 __vsock_remove_bound(vsk);
 291         spin_unlock_bh(&vsock_table_lock);
 292 }
 293 EXPORT_SYMBOL_GPL(vsock_remove_bound);
 294
 295 void vsock_remove_connected(struct vsock_sock *vsk)
 296 {
 297         spin_lock_bh(&vsock_table_lock);
 298         if (__vsock_in_connected_table(vsk))
 299                 __vsock_remove_connected(vsk);
 300         spin_unlock_bh(&vsock_table_lock);
 301 }
 302 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 303
 304 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 305 {
 306         struct sock *sk;
 307
 308         spin_lock_bh(&vsock_table_lock);
 309         sk = __vsock_find_bound_socket(addr);
 310         if (sk)
 311                 sock_hold(sk);
 312
 313         spin_unlock_bh(&vsock_table_lock);
 314
 315         return sk;
 316 }
 317 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 318
 319 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 320                                          struct sockaddr_vm *dst)
 321 {
 322         struct sock *sk;
 323
 324         spin_lock_bh(&vsock_table_lock);
 325         sk = __vsock_find_connected_socket(src, dst);
 326         if (sk)
 327                 sock_hold(sk);
 328
 329         spin_unlock_bh(&vsock_table_lock);
 330
 331         return sk;
 332 }
 333 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 334
 335 void vsock_remove_sock(struct vsock_sock *vsk)
 336 {
 337         vsock_remove_bound(vsk);
 338         vsock_remove_connected(vsk);
 339 }
 340 EXPORT_SYMBOL_GPL(vsock_remove_sock);
 341
 342 void vsock_for_each_connected_socket(struct vsock_transport *transport,
 343                                      void (*fn)(struct sock *sk))
 344 {
 345         int i;
 346
 347         spin_lock_bh(&vsock_table_lock);
 348
 349         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
 350                 struct vsock_sock *vsk;
 351                 list_for_each_entry(vsk, &vsock_connected_table[i],
 352                                     connected_table) {
 353                         if (vsk->transport != transport)
 354                                 continue;
 355
 356                         fn(sk_vsock(vsk));
 357                 }
 358         }
 359
 360         spin_unlock_bh(&vsock_table_lock);
 361 }
 362 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
 363
 364 void vsock_add_pending(struct sock *listener, struct sock *pending)
 365 {
 366         struct vsock_sock *vlistener;
 367         struct vsock_sock *vpending;
 368
 369         vlistener = vsock_sk(listener);
 370         vpending = vsock_sk(pending);
 371
 372         sock_hold(pending);
 373         sock_hold(listener);
 374         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 375 }
 376 EXPORT_SYMBOL_GPL(vsock_add_pending);
 377
 378 void vsock_remove_pending(struct sock *listener, struct sock *pending)
 379 {
 380         struct vsock_sock *vpending = vsock_sk(pending);
 381
 382         list_del_init(&vpending->pending_links);
 383         sock_put(listener);
 384         sock_put(pending);
 385 }
 386 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 387
 388 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 389 {
 390         struct vsock_sock *vlistener;
 391         struct vsock_sock *vconnected;
 392
 393         vlistener = vsock_sk(listener);
 394         vconnected = vsock_sk(connected);
 395
 396         sock_hold(connected);
 397         sock_hold(listener);
 398         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 399 }
 400 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 401
 402 static bool vsock_use_local_transport(unsigned int remote_cid)
 403 {
 404         if (!transport_local)
 405                 return false;
 406
 407         if (remote_cid == VMADDR_CID_LOCAL)
 408                 return true;
 409
 410         if (transport_g2h) {
 411                 return remote_cid == transport_g2h->get_local_cid();
 412         } else {
 413                 return remote_cid == VMADDR_CID_HOST;
 414         }
 415 }
 416
 417 static void vsock_deassign_transport(struct vsock_sock *vsk)
 418 {
 419         if (!vsk->transport)
 420                 return;
 421
 422         vsk->transport->destruct(vsk);
 423         module_put(vsk->transport->module);
 424         vsk->transport = NULL;
 425 }
 426
 427 /* Assign a transport to a socket and call the .init transport callback.
 428  *
 429  * Note: for connection oriented socket this must be called when vsk->remote_addr
 430  * is set (e.g. during the connect() or when a connection request on a listener
 431  * socket is received).
 432  * The vsk->remote_addr is used to decide which transport to use:
 433  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 434  *    g2h is not loaded, will use local transport;
 435  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 436  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 437  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 438  */
 439 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 440 {
 441         const struct vsock_transport *new_transport;
 442         struct sock *sk = sk_vsock(vsk);
 443         unsigned int remote_cid = vsk->remote_addr.svm_cid;
 444         __u8 remote_flags;
 445         int ret;
 446
 447         /* If the packet is coming with the source and destination CIDs higher
 448          * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 449          * forwarded to the host should be established. Then the host will
 450          * need to forward the packets to the guest.
 451          *
 452          * The flag is set on the (listen) receive path (psk is not NULL). On
 453          * the connect path the flag can be set by the user space application.
 454          */
 455         if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 456             vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 457                 vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 458
 459         remote_flags = vsk->remote_addr.svm_flags;
 460
 461         switch (sk->sk_type) {
 462         case SOCK_DGRAM:
 463                 new_transport = transport_dgram;
 464                 break;
 465         case SOCK_STREAM:
 466         case SOCK_SEQPACKET:
 467                 if (vsock_use_local_transport(remote_cid))
 468                         new_transport = transport_local;
 469                 else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 470                          (remote_flags & VMADDR_FLAG_TO_HOST))
 471                         new_transport = transport_g2h;
 472                 else
 473                         new_transport = transport_h2g;
 474                 break;
 475         default:
 476                 return -ESOCKTNOSUPPORT;
 477         }
 478
 479         if (vsk->transport) {
 480                 if (vsk->transport == new_transport)
 481                         return 0;
 482
 483                 /* transport->release() must be called with sock lock acquired.
 484                  * This path can only be taken during vsock_connect(), where we
 485                  * have already held the sock lock. In the other cases, this
 486                  * function is called on a new socket which is not assigned to
 487                  * any transport.
 488                  */
 489                 vsk->transport->release(vsk);
 490                 vsock_deassign_transport(vsk);
 491         }
 492
 493         /* We increase the module refcnt to prevent the transport unloading
 494          * while there are open sockets assigned to it.
 495          */
 496         if (!new_transport || !try_module_get(new_transport->module))
 497                 return -ENODEV;
 498
 499         if (sk->sk_type == SOCK_SEQPACKET) {
 500                 if (!new_transport->seqpacket_allow ||
 501                     !new_transport->seqpacket_allow(remote_cid)) {
 502                         module_put(new_transport->module);
 503                         return -ESOCKTNOSUPPORT;
 504                 }
 505         }
 506
 507         ret = new_transport->init(vsk, psk);
 508         if (ret) {
 509                 module_put(new_transport->module);
 510                 return ret;
 511         }
 512
 513         vsk->transport = new_transport;
 514
 515         return 0;
 516 }
 517 EXPORT_SYMBOL_GPL(vsock_assign_transport);
 518
 519 bool vsock_find_cid(unsigned int cid)
 520 {
 521         if (transport_g2h && cid == transport_g2h->get_local_cid())
 522                 return true;
 523
 524         if (transport_h2g && cid == VMADDR_CID_HOST)
 525                 return true;
 526
 527         if (transport_local && cid == VMADDR_CID_LOCAL)
 528                 return true;
 529
 530         return false;
 531 }
 532 EXPORT_SYMBOL_GPL(vsock_find_cid);
 533
 534 static struct sock *vsock_dequeue_accept(struct sock *listener)
 535 {
 536         struct vsock_sock *vlistener;
 537         struct vsock_sock *vconnected;
 538
 539         vlistener = vsock_sk(listener);
 540
 541         if (list_empty(&vlistener->accept_queue))
 542                 return NULL;
 543
 544         vconnected = list_entry(vlistener->accept_queue.next,
 545                                 struct vsock_sock, accept_queue);
 546
 547         list_del_init(&vconnected->accept_queue);
 548         sock_put(listener);
 549         /* The caller will need a reference on the connected socket so we let
 550          * it call sock_put().
 551          */
 552
 553         return sk_vsock(vconnected);
 554 }
 555
 556 static bool vsock_is_accept_queue_empty(struct sock *sk)
 557 {
 558         struct vsock_sock *vsk = vsock_sk(sk);
 559         return list_empty(&vsk->accept_queue);
 560 }
 561
 562 static bool vsock_is_pending(struct sock *sk)
 563 {
 564         struct vsock_sock *vsk = vsock_sk(sk);
 565         return !list_empty(&vsk->pending_links);
 566 }
 567
 568 static int vsock_send_shutdown(struct sock *sk, int mode)
 569 {
 570         struct vsock_sock *vsk = vsock_sk(sk);
 571
 572         if (!vsk->transport)
 573                 return -ENODEV;
 574
 575         return vsk->transport->shutdown(vsk, mode);
 576 }
 577
 578 static void vsock_pending_work(struct work_struct *work)
 579 {
 580         struct sock *sk;
 581         struct sock *listener;
 582         struct vsock_sock *vsk;
 583         bool cleanup;
 584
 585         vsk = container_of(work, struct vsock_sock, pending_work.work);
 586         sk = sk_vsock(vsk);
 587         listener = vsk->listener;
 588         cleanup = true;
 589
 590         lock_sock(listener);
 591         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 592
 593         if (vsock_is_pending(sk)) {
 594                 vsock_remove_pending(listener, sk);
 595
 596                 sk_acceptq_removed(listener);
 597         } else if (!vsk->rejected) {
 598                 /* We are not on the pending list and accept() did not reject
 599                  * us, so we must have been accepted by our user process.  We
 600                  * just need to drop our references to the sockets and be on
 601                  * our way.
 602                  */
 603                 cleanup = false;
 604                 goto out;
 605         }
 606
 607         /* We need to remove ourself from the global connected sockets list so
 608          * incoming packets can't find this socket, and to reduce the reference
 609          * count.
 610          */
 611         vsock_remove_connected(vsk);
 612
 613         sk->sk_state = TCP_CLOSE;
 614
 615 out:
 616         release_sock(sk);
 617         release_sock(listener);
 618         if (cleanup)
 619                 sock_put(sk);
 620
 621         sock_put(sk);
 622         sock_put(listener);
 623 }
 624
 625 /**** SOCKET OPERATIONS ****/
 626
 627 static int __vsock_bind_connectible(struct vsock_sock *vsk,
 628                                     struct sockaddr_vm *addr)
 629 {
 630         static u32 port;
 631         struct sockaddr_vm new_addr;
 632
 633         if (!port)
 634                 port = get_random_u32_above(LAST_RESERVED_PORT);
 635
 636         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 637
 638         if (addr->svm_port == VMADDR_PORT_ANY) {
 639                 bool found = false;
 640                 unsigned int i;
 641
 642                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
 643                         if (port <= LAST_RESERVED_PORT)
 644                                 port = LAST_RESERVED_PORT + 1;
 645
 646                         new_addr.svm_port = port++;
 647
 648                         if (!__vsock_find_bound_socket(&new_addr)) {
 649                                 found = true;
 650                                 break;
 651                         }
 652                 }
 653
 654                 if (!found)
 655                         return -EADDRNOTAVAIL;
 656         } else {
 657                 /* If port is in reserved range, ensure caller
 658                  * has necessary privileges.
 659                  */
 660                 if (addr->svm_port <= LAST_RESERVED_PORT &&
 661                     !capable(CAP_NET_BIND_SERVICE)) {
 662                         return -EACCES;
 663                 }
 664
 665                 if (__vsock_find_bound_socket(&new_addr))
 666                         return -EADDRINUSE;
 667         }
 668
 669         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
 670
 671         /* Remove connection oriented sockets from the unbound list and add them
 672          * to the hash table for easy lookup by its address.  The unbound list
 673          * is simply an extra entry at the end of the hash table, a trick used
 674          * by AF_UNIX.
 675          */
 676         __vsock_remove_bound(vsk);
 677         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
 678
 679         return 0;
 680 }
 681
 682 static int __vsock_bind_dgram(struct vsock_sock *vsk,
 683                               struct sockaddr_vm *addr)
 684 {
 685         return vsk->transport->dgram_bind(vsk, addr);
 686 }
 687
 688 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 689 {
 690         struct vsock_sock *vsk = vsock_sk(sk);
 691         int retval;
 692
 693         /* First ensure this socket isn't already bound. */
 694         if (vsock_addr_bound(&vsk->local_addr))
 695                 return -EINVAL;
 696
 697         /* Now bind to the provided address or select appropriate values if
 698          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
 699          * like AF_INET prevents binding to a non-local IP address (in most
 700          * cases), we only allow binding to a local CID.
 701          */
 702         if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
 703                 return -EADDRNOTAVAIL;
 704
 705         switch (sk->sk_socket->type) {
 706         case SOCK_STREAM:
 707         case SOCK_SEQPACKET:
 708                 spin_lock_bh(&vsock_table_lock);
 709                 retval = __vsock_bind_connectible(vsk, addr);
 710                 spin_unlock_bh(&vsock_table_lock);
 711                 break;
 712
 713         case SOCK_DGRAM:
 714                 retval = __vsock_bind_dgram(vsk, addr);
 715                 break;
 716
 717         default:
 718                 retval = -EINVAL;
 719                 break;
 720         }
 721
 722         return retval;
 723 }
 724
 725 static void vsock_connect_timeout(struct work_struct *work);
 726
 727 static struct sock *__vsock_create(struct net *net,
 728                                    struct socket *sock,
 729                                    struct sock *parent,
 730                                    gfp_t priority,
 731                                    unsigned short type,
 732                                    int kern)
 733 {
 734         struct sock *sk;
 735         struct vsock_sock *psk;
 736         struct vsock_sock *vsk;
 737
 738         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 739         if (!sk)
 740                 return NULL;
 741
 742         sock_init_data(sock, sk);
 743
 744         /* sk->sk_type is normally set in sock_init_data, but only if sock is
 745          * non-NULL. We make sure that our sockets always have a type by
 746          * setting it here if needed.
 747          */
 748         if (!sock)
 749                 sk->sk_type = type;
 750
 751         vsk = vsock_sk(sk);
 752         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 753         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 754
 755         sk->sk_destruct = vsock_sk_destruct;
 756         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 757         sock_reset_flag(sk, SOCK_DONE);
 758
 759         INIT_LIST_HEAD(&vsk->bound_table);
 760         INIT_LIST_HEAD(&vsk->connected_table);
 761         vsk->listener = NULL;
 762         INIT_LIST_HEAD(&vsk->pending_links);
 763         INIT_LIST_HEAD(&vsk->accept_queue);
 764         vsk->rejected = false;
 765         vsk->sent_request = false;
 766         vsk->ignore_connecting_rst = false;
 767         vsk->peer_shutdown = 0;
 768         INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 769         INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 770
 771         psk = parent ? vsock_sk(parent) : NULL;
 772         if (parent) {
 773                 vsk->trusted = psk->trusted;
 774                 vsk->owner = get_cred(psk->owner);
 775                 vsk->connect_timeout = psk->connect_timeout;
 776                 vsk->buffer_size = psk->buffer_size;
 777                 vsk->buffer_min_size = psk->buffer_min_size;
 778                 vsk->buffer_max_size = psk->buffer_max_size;
 779                 security_sk_clone(parent, sk);
 780         } else {
 781                 vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
 782                 vsk->owner = get_current_cred();
 783                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 784                 vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
 785                 vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
 786                 vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
 787         }
 788
 789         return sk;
 790 }
 791
 792 static bool sock_type_connectible(u16 type)
 793 {
 794         return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
 795 }
 796
 797 static void __vsock_release(struct sock *sk, int level)
 798 {
 799         if (sk) {
 800                 struct sock *pending;
 801                 struct vsock_sock *vsk;
 802
 803                 vsk = vsock_sk(sk);
 804                 pending = NULL; /* Compiler warning. */
 805
 806                 /* When "level" is SINGLE_DEPTH_NESTING, use the nested
 807                  * version to avoid the warning "possible recursive locking
 808                  * detected". When "level" is 0, lock_sock_nested(sk, level)
 809                  * is the same as lock_sock(sk).
 810                  */
 811                 lock_sock_nested(sk, level);
 812
 813                 if (vsk->transport)
 814                         vsk->transport->release(vsk);
 815                 else if (sock_type_connectible(sk->sk_type))
 816                         vsock_remove_sock(vsk);
 817
 818                 sock_orphan(sk);
 819                 sk->sk_shutdown = SHUTDOWN_MASK;
 820
 821                 skb_queue_purge(&sk->sk_receive_queue);
 822
 823                 /* Clean up any sockets that never were accepted. */
 824                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 825                         __vsock_release(pending, SINGLE_DEPTH_NESTING);
 826                         sock_put(pending);
 827                 }
 828
 829                 release_sock(sk);
 830                 sock_put(sk);
 831         }
 832 }
 833
 834 static void vsock_sk_destruct(struct sock *sk)
 835 {
 836         struct vsock_sock *vsk = vsock_sk(sk);
 837
 838         vsock_deassign_transport(vsk);
 839
 840         /* When clearing these addresses, there's no need to set the family and
 841          * possibly register the address family with the kernel.
 842          */
 843         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 844         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 845
 846         put_cred(vsk->owner);
 847 }
 848
 849 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 850 {
 851         int err;
 852
 853         err = sock_queue_rcv_skb(sk, skb);
 854         if (err)
 855                 kfree_skb(skb);
 856
 857         return err;
 858 }
 859
 860 struct sock *vsock_create_connected(struct sock *parent)
 861 {
 862         return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
 863                               parent->sk_type, 0);
 864 }
 865 EXPORT_SYMBOL_GPL(vsock_create_connected);
 866
 867 s64 vsock_stream_has_data(struct vsock_sock *vsk)
 868 {
 869         return vsk->transport->stream_has_data(vsk);
 870 }
 871 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 872
 873 s64 vsock_connectible_has_data(struct vsock_sock *vsk)
 874 {
 875         struct sock *sk = sk_vsock(vsk);
 876
 877         if (sk->sk_type == SOCK_SEQPACKET)
 878                 return vsk->transport->seqpacket_has_data(vsk);
 879         else
 880                 return vsock_stream_has_data(vsk);
 881 }
 882 EXPORT_SYMBOL_GPL(vsock_connectible_has_data);
 883
 884 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 885 {
 886         return vsk->transport->stream_has_space(vsk);
 887 }
 888 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 889
 890 void vsock_data_ready(struct sock *sk)
 891 {
 892         struct vsock_sock *vsk = vsock_sk(sk);
 893
 894         if (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
 895             sock_flag(sk, SOCK_DONE))
 896                 sk->sk_data_ready(sk);
 897 }
 898 EXPORT_SYMBOL_GPL(vsock_data_ready);
 899
 900 static int vsock_release(struct socket *sock)
 901 {
 902         __vsock_release(sock->sk, 0);
 903         sock->sk = NULL;
 904         sock->state = SS_FREE;
 905
 906         return 0;
 907 }
 908
 909 static int
 910 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 911 {
 912         int err;
 913         struct sock *sk;
 914         struct sockaddr_vm *vm_addr;
 915
 916         sk = sock->sk;
 917
 918         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 919                 return -EINVAL;
 920
 921         lock_sock(sk);
 922         err = __vsock_bind(sk, vm_addr);
 923         release_sock(sk);
 924
 925         return err;
 926 }
 927
 928 static int vsock_getname(struct socket *sock,
 929                          struct sockaddr *addr, int peer)
 930 {
 931         int err;
 932         struct sock *sk;
 933         struct vsock_sock *vsk;
 934         struct sockaddr_vm *vm_addr;
 935
 936         sk = sock->sk;
 937         vsk = vsock_sk(sk);
 938         err = 0;
 939
 940         lock_sock(sk);
 941
 942         if (peer) {
 943                 if (sock->state != SS_CONNECTED) {
 944                         err = -ENOTCONN;
 945                         goto out;
 946                 }
 947                 vm_addr = &vsk->remote_addr;
 948         } else {
 949                 vm_addr = &vsk->local_addr;
 950         }
 951
 952         if (!vm_addr) {
 953                 err = -EINVAL;
 954                 goto out;
 955         }
 956
 957         /* sys_getsockname() and sys_getpeername() pass us a
 958          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 959          * that macro is defined in socket.c instead of .h, so we hardcode its
 960          * value here.
 961          */
 962         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 963         memcpy(addr, vm_addr, sizeof(*vm_addr));
 964         err = sizeof(*vm_addr);
 965
 966 out:
 967         release_sock(sk);
 968         return err;
 969 }
 970
 971 static int vsock_shutdown(struct socket *sock, int mode)
 972 {
 973         int err;
 974         struct sock *sk;
 975
 976         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 977          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 978          * here like the other address families do.  Note also that the
 979          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 980          * which is what we want.
 981          */
 982         mode++;
 983
 984         if ((mode & ~SHUTDOWN_MASK) || !mode)
 985                 return -EINVAL;
 986
 987         /* If this is a connection oriented socket and it is not connected then
 988          * bail out immediately.  If it is a DGRAM socket then we must first
 989          * kick the socket so that it wakes up from any sleeping calls, for
 990          * example recv(), and then afterwards return the error.
 991          */
 992
 993         sk = sock->sk;
 994
 995         lock_sock(sk);
 996         if (sock->state == SS_UNCONNECTED) {
 997                 err = -ENOTCONN;
 998                 if (sock_type_connectible(sk->sk_type))
 999                         goto out;
1000         } else {
1001                 sock->state = SS_DISCONNECTING;
1002                 err = 0;
1003         }
1004
1005         /* Receive and send shutdowns are treated alike. */
1006         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
1007         if (mode) {
1008                 sk->sk_shutdown |= mode;
1009                 sk->sk_state_change(sk);
1010
1011                 if (sock_type_connectible(sk->sk_type)) {
1012                         sock_reset_flag(sk, SOCK_DONE);
1013                         vsock_send_shutdown(sk, mode);
1014                 }
1015         }
1016
1017 out:
1018         release_sock(sk);
1019         return err;
1020 }
1021
1022 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1023                                poll_table *wait)
1024 {
1025         struct sock *sk;
1026         __poll_t mask;
1027         struct vsock_sock *vsk;
1028
1029         sk = sock->sk;
1030         vsk = vsock_sk(sk);
1031
1032         poll_wait(file, sk_sleep(sk), wait);
1033         mask = 0;
1034
1035         if (sk->sk_err)
1036                 /* Signify that there has been an error on this socket. */
1037                 mask |= EPOLLERR;
1038
1039         /* INET sockets treat local write shutdown and peer write shutdown as a
1040          * case of EPOLLHUP set.
1041          */
1042         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1043             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1044              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1045                 mask |= EPOLLHUP;
1046         }
1047
1048         if (sk->sk_shutdown & RCV_SHUTDOWN ||
1049             vsk->peer_shutdown & SEND_SHUTDOWN) {
1050                 mask |= EPOLLRDHUP;
1051         }
1052
1053         if (sock->type == SOCK_DGRAM) {
1054                 /* For datagram sockets we can read if there is something in
1055                  * the queue and write as long as the socket isn't shutdown for
1056                  * sending.
1057                  */
1058                 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1059                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
1060                         mask |= EPOLLIN | EPOLLRDNORM;
1061                 }
1062
1063                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1064                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1065
1066         } else if (sock_type_connectible(sk->sk_type)) {
1067                 const struct vsock_transport *transport;
1068
1069                 lock_sock(sk);
1070
1071                 transport = vsk->transport;
1072
1073                 /* Listening sockets that have connections in their accept
1074                  * queue can be read.
1075                  */
1076                 if (sk->sk_state == TCP_LISTEN
1077                     && !vsock_is_accept_queue_empty(sk))
1078                         mask |= EPOLLIN | EPOLLRDNORM;
1079
1080                 /* If there is something in the queue then we can read. */
1081                 if (transport && transport->stream_is_active(vsk) &&
1082                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1083                         bool data_ready_now = false;
1084                         int target = sock_rcvlowat(sk, 0, INT_MAX);
1085                         int ret = transport->notify_poll_in(
1086                                         vsk, target, &data_ready_now);
1087                         if (ret < 0) {
1088                                 mask |= EPOLLERR;
1089                         } else {
1090                                 if (data_ready_now)
1091                                         mask |= EPOLLIN | EPOLLRDNORM;
1092
1093                         }
1094                 }
1095
1096                 /* Sockets whose connections have been closed, reset, or
1097                  * terminated should also be considered read, and we check the
1098                  * shutdown flag for that.
1099                  */
1100                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
1101                     vsk->peer_shutdown & SEND_SHUTDOWN) {
1102                         mask |= EPOLLIN | EPOLLRDNORM;
1103                 }
1104
1105                 /* Connected sockets that can produce data can be written. */
1106                 if (transport && sk->sk_state == TCP_ESTABLISHED) {
1107                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1108                                 bool space_avail_now = false;
1109                                 int ret = transport->notify_poll_out(
1110                                                 vsk, 1, &space_avail_now);
1111                                 if (ret < 0) {
1112                                         mask |= EPOLLERR;
1113                                 } else {
1114                                         if (space_avail_now)
1115                                                 /* Remove EPOLLWRBAND since INET
1116                                                  * sockets are not setting it.
1117                                                  */
1118                                                 mask |= EPOLLOUT | EPOLLWRNORM;
1119
1120                                 }
1121                         }
1122                 }
1123
1124                 /* Simulate INET socket poll behaviors, which sets
1125                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1126                  * but local send is not shutdown.
1127                  */
1128                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1129                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1130                                 mask |= EPOLLOUT | EPOLLWRNORM;
1131
1132                 }
1133
1134                 release_sock(sk);
1135         }
1136
1137         return mask;
1138 }
1139
1140 static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor)
1141 {
1142         struct vsock_sock *vsk = vsock_sk(sk);
1143
1144         return vsk->transport->read_skb(vsk, read_actor);
1145 }
1146
1147 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1148                                size_t len)
1149 {
1150         int err;
1151         struct sock *sk;
1152         struct vsock_sock *vsk;
1153         struct sockaddr_vm *remote_addr;
1154         const struct vsock_transport *transport;
1155
1156         if (msg->msg_flags & MSG_OOB)
1157                 return -EOPNOTSUPP;
1158
1159         /* For now, MSG_DONTWAIT is always assumed... */
1160         err = 0;
1161         sk = sock->sk;
1162         vsk = vsock_sk(sk);
1163
1164         lock_sock(sk);
1165
1166         transport = vsk->transport;
1167
1168         err = vsock_auto_bind(vsk);
1169         if (err)
1170                 goto out;
1171
1172
1173         /* If the provided message contains an address, use that.  Otherwise
1174          * fall back on the socket's remote handle (if it has been connected).
1175          */
1176         if (msg->msg_name &&
1177             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1178                             &remote_addr) == 0) {
1179                 /* Ensure this address is of the right type and is a valid
1180                  * destination.
1181                  */
1182
1183                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1184                         remote_addr->svm_cid = transport->get_local_cid();
1185
1186                 if (!vsock_addr_bound(remote_addr)) {
1187                         err = -EINVAL;
1188                         goto out;
1189                 }
1190         } else if (sock->state == SS_CONNECTED) {
1191                 remote_addr = &vsk->remote_addr;
1192
1193                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1194                         remote_addr->svm_cid = transport->get_local_cid();
1195
1196                 /* XXX Should connect() or this function ensure remote_addr is
1197                  * bound?
1198                  */
1199                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1200                         err = -EINVAL;
1201                         goto out;
1202                 }
1203         } else {
1204                 err = -EINVAL;
1205                 goto out;
1206         }
1207
1208         if (!transport->dgram_allow(remote_addr->svm_cid,
1209                                     remote_addr->svm_port)) {
1210                 err = -EINVAL;
1211                 goto out;
1212         }
1213
1214         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1215
1216 out:
1217         release_sock(sk);
1218         return err;
1219 }
1220
1221 static int vsock_dgram_connect(struct socket *sock,
1222                                struct sockaddr *addr, int addr_len, int flags)
1223 {
1224         int err;
1225         struct sock *sk;
1226         struct vsock_sock *vsk;
1227         struct sockaddr_vm *remote_addr;
1228
1229         sk = sock->sk;
1230         vsk = vsock_sk(sk);
1231
1232         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1233         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1234                 lock_sock(sk);
1235                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1236                                 VMADDR_PORT_ANY);
1237                 sock->state = SS_UNCONNECTED;
1238                 release_sock(sk);
1239                 return 0;
1240         } else if (err != 0)
1241                 return -EINVAL;
1242
1243         lock_sock(sk);
1244
1245         err = vsock_auto_bind(vsk);
1246         if (err)
1247                 goto out;
1248
1249         if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1250                                          remote_addr->svm_port)) {
1251                 err = -EINVAL;
1252                 goto out;
1253         }
1254
1255         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1256         sock->state = SS_CONNECTED;
1257
1258         /* sock map disallows redirection of non-TCP sockets with sk_state !=
1259          * TCP_ESTABLISHED (see sock_map_redirect_allowed()), so we set
1260          * TCP_ESTABLISHED here to allow redirection of connected vsock dgrams.
1261          *
1262          * This doesn't seem to be abnormal state for datagram sockets, as the
1263          * same approach can be see in other datagram socket types as well
1264          * (such as unix sockets).
1265          */
1266         sk->sk_state = TCP_ESTABLISHED;
1267
1268 out:
1269         release_sock(sk);
1270         return err;
1271 }
1272
1273 int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1274                         size_t len, int flags)
1275 {
1276 #ifdef CONFIG_BPF_SYSCALL
1277         const struct proto *prot;
1278 #endif
1279         struct vsock_sock *vsk;
1280         struct sock *sk;
1281
1282         sk = sock->sk;
1283         vsk = vsock_sk(sk);
1284
1285 #ifdef CONFIG_BPF_SYSCALL
1286         prot = READ_ONCE(sk->sk_prot);
1287         if (prot != &vsock_proto)
1288                 return prot->recvmsg(sk, msg, len, flags, NULL);
1289 #endif
1290
1291         return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1292 }
1293 EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
1294
1295 static const struct proto_ops vsock_dgram_ops = {
1296         .family = PF_VSOCK,
1297         .owner = THIS_MODULE,
1298         .release = vsock_release,
1299         .bind = vsock_bind,
1300         .connect = vsock_dgram_connect,
1301         .socketpair = sock_no_socketpair,
1302         .accept = sock_no_accept,
1303         .getname = vsock_getname,
1304         .poll = vsock_poll,
1305         .ioctl = sock_no_ioctl,
1306         .listen = sock_no_listen,
1307         .shutdown = vsock_shutdown,
1308         .sendmsg = vsock_dgram_sendmsg,
1309         .recvmsg = vsock_dgram_recvmsg,
1310         .mmap = sock_no_mmap,
1311         .read_skb = vsock_read_skb,
1312 };
1313
1314 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1315 {
1316         const struct vsock_transport *transport = vsk->transport;
1317
1318         if (!transport || !transport->cancel_pkt)
1319                 return -EOPNOTSUPP;
1320
1321         return transport->cancel_pkt(vsk);
1322 }
1323
1324 static void vsock_connect_timeout(struct work_struct *work)
1325 {
1326         struct sock *sk;
1327         struct vsock_sock *vsk;
1328
1329         vsk = container_of(work, struct vsock_sock, connect_work.work);
1330         sk = sk_vsock(vsk);
1331
1332         lock_sock(sk);
1333         if (sk->sk_state == TCP_SYN_SENT &&
1334             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1335                 sk->sk_state = TCP_CLOSE;
1336                 sk->sk_socket->state = SS_UNCONNECTED;
1337                 sk->sk_err = ETIMEDOUT;
1338                 sk_error_report(sk);
1339                 vsock_transport_cancel_pkt(vsk);
1340         }
1341         release_sock(sk);
1342
1343         sock_put(sk);
1344 }
1345
1346 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1347                          int addr_len, int flags)
1348 {
1349         int err;
1350         struct sock *sk;
1351         struct vsock_sock *vsk;
1352         const struct vsock_transport *transport;
1353         struct sockaddr_vm *remote_addr;
1354         long timeout;
1355         DEFINE_WAIT(wait);
1356
1357         err = 0;
1358         sk = sock->sk;
1359         vsk = vsock_sk(sk);
1360
1361         lock_sock(sk);
1362
1363         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1364         switch (sock->state) {
1365         case SS_CONNECTED:
1366                 err = -EISCONN;
1367                 goto out;
1368         case SS_DISCONNECTING:
1369                 err = -EINVAL;
1370                 goto out;
1371         case SS_CONNECTING:
1372                 /* This continues on so we can move sock into the SS_CONNECTED
1373                  * state once the connection has completed (at which point err
1374                  * will be set to zero also).  Otherwise, we will either wait
1375                  * for the connection or return -EALREADY should this be a
1376                  * non-blocking call.
1377                  */
1378                 err = -EALREADY;
1379                 if (flags & O_NONBLOCK)
1380                         goto out;
1381                 break;
1382         default:
1383                 if ((sk->sk_state == TCP_LISTEN) ||
1384                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1385                         err = -EINVAL;
1386                         goto out;
1387                 }
1388
1389                 /* Set the remote address that we are connecting to. */
1390                 memcpy(&vsk->remote_addr, remote_addr,
1391                        sizeof(vsk->remote_addr));
1392
1393                 err = vsock_assign_transport(vsk, NULL);
1394                 if (err)
1395                         goto out;
1396
1397                 transport = vsk->transport;
1398
1399                 /* The hypervisor and well-known contexts do not have socket
1400                  * endpoints.
1401                  */
1402                 if (!transport ||
1403                     !transport->stream_allow(remote_addr->svm_cid,
1404                                              remote_addr->svm_port)) {
1405                         err = -ENETUNREACH;
1406                         goto out;
1407                 }
1408
1409                 err = vsock_auto_bind(vsk);
1410                 if (err)
1411                         goto out;
1412
1413                 sk->sk_state = TCP_SYN_SENT;
1414
1415                 err = transport->connect(vsk);
1416                 if (err < 0)
1417                         goto out;
1418
1419                 /* Mark sock as connecting and set the error code to in
1420                  * progress in case this is a non-blocking connect.
1421                  */
1422                 sock->state = SS_CONNECTING;
1423                 err = -EINPROGRESS;
1424         }
1425
1426         /* The receive path will handle all communication until we are able to
1427          * enter the connected state.  Here we wait for the connection to be
1428          * completed or a notification of an error.
1429          */
1430         timeout = vsk->connect_timeout;
1431         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1432
1433         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1434                 if (flags & O_NONBLOCK) {
1435                         /* If we're not going to block, we schedule a timeout
1436                          * function to generate a timeout on the connection
1437                          * attempt, in case the peer doesn't respond in a
1438                          * timely manner. We hold on to the socket until the
1439                          * timeout fires.
1440                          */
1441                         sock_hold(sk);
1442
1443                         /* If the timeout function is already scheduled,
1444                          * reschedule it, then ungrab the socket refcount to
1445                          * keep it balanced.
1446                          */
1447                         if (mod_delayed_work(system_wq, &vsk->connect_work,
1448                                              timeout))
1449                                 sock_put(sk);
1450
1451                         /* Skip ahead to preserve error code set above. */
1452                         goto out_wait;
1453                 }
1454
1455                 release_sock(sk);
1456                 timeout = schedule_timeout(timeout);
1457                 lock_sock(sk);
1458
1459                 if (signal_pending(current)) {
1460                         err = sock_intr_errno(timeout);
1461                         sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1462                         sock->state = SS_UNCONNECTED;
1463                         vsock_transport_cancel_pkt(vsk);
1464                         vsock_remove_connected(vsk);
1465                         goto out_wait;
1466                 } else if ((sk->sk_state != TCP_ESTABLISHED) && (timeout == 0)) {
1467                         err = -ETIMEDOUT;
1468                         sk->sk_state = TCP_CLOSE;
1469                         sock->state = SS_UNCONNECTED;
1470                         vsock_transport_cancel_pkt(vsk);
1471                         goto out_wait;
1472                 }
1473
1474                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1475         }
1476
1477         if (sk->sk_err) {
1478                 err = -sk->sk_err;
1479                 sk->sk_state = TCP_CLOSE;
1480                 sock->state = SS_UNCONNECTED;
1481         } else {
1482                 err = 0;
1483         }
1484
1485 out_wait:
1486         finish_wait(sk_sleep(sk), &wait);
1487 out:
1488         release_sock(sk);
1489         return err;
1490 }
1491
1492 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1493                         bool kern)
1494 {
1495         struct sock *listener;
1496         int err;
1497         struct sock *connected;
1498         struct vsock_sock *vconnected;
1499         long timeout;
1500         DEFINE_WAIT(wait);
1501
1502         err = 0;
1503         listener = sock->sk;
1504
1505         lock_sock(listener);
1506
1507         if (!sock_type_connectible(sock->type)) {
1508                 err = -EOPNOTSUPP;
1509                 goto out;
1510         }
1511
1512         if (listener->sk_state != TCP_LISTEN) {
1513                 err = -EINVAL;
1514                 goto out;
1515         }
1516
1517         /* Wait for children sockets to appear; these are the new sockets
1518          * created upon connection establishment.
1519          */
1520         timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1521         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1522
1523         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1524                listener->sk_err == 0) {
1525                 release_sock(listener);
1526                 timeout = schedule_timeout(timeout);
1527                 finish_wait(sk_sleep(listener), &wait);
1528                 lock_sock(listener);
1529
1530                 if (signal_pending(current)) {
1531                         err = sock_intr_errno(timeout);
1532                         goto out;
1533                 } else if (timeout == 0) {
1534                         err = -EAGAIN;
1535                         goto out;
1536                 }
1537
1538                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1539         }
1540         finish_wait(sk_sleep(listener), &wait);
1541
1542         if (listener->sk_err)
1543                 err = -listener->sk_err;
1544
1545         if (connected) {
1546                 sk_acceptq_removed(listener);
1547
1548                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1549                 vconnected = vsock_sk(connected);
1550
1551                 /* If the listener socket has received an error, then we should
1552                  * reject this socket and return.  Note that we simply mark the
1553                  * socket rejected, drop our reference, and let the cleanup
1554                  * function handle the cleanup; the fact that we found it in
1555                  * the listener's accept queue guarantees that the cleanup
1556                  * function hasn't run yet.
1557                  */
1558                 if (err) {
1559                         vconnected->rejected = true;
1560                 } else {
1561                         newsock->state = SS_CONNECTED;
1562                         sock_graft(connected, newsock);
1563                 }
1564
1565                 release_sock(connected);
1566                 sock_put(connected);
1567         }
1568
1569 out:
1570         release_sock(listener);
1571         return err;
1572 }
1573
1574 static int vsock_listen(struct socket *sock, int backlog)
1575 {
1576         int err;
1577         struct sock *sk;
1578         struct vsock_sock *vsk;
1579
1580         sk = sock->sk;
1581
1582         lock_sock(sk);
1583
1584         if (!sock_type_connectible(sk->sk_type)) {
1585                 err = -EOPNOTSUPP;
1586                 goto out;
1587         }
1588
1589         if (sock->state != SS_UNCONNECTED) {
1590                 err = -EINVAL;
1591                 goto out;
1592         }
1593
1594         vsk = vsock_sk(sk);
1595
1596         if (!vsock_addr_bound(&vsk->local_addr)) {
1597                 err = -EINVAL;
1598                 goto out;
1599         }
1600
1601         sk->sk_max_ack_backlog = backlog;
1602         sk->sk_state = TCP_LISTEN;
1603
1604         err = 0;
1605
1606 out:
1607         release_sock(sk);
1608         return err;
1609 }
1610
1611 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1612                                      const struct vsock_transport *transport,
1613                                      u64 val)
1614 {
1615         if (val > vsk->buffer_max_size)
1616                 val = vsk->buffer_max_size;
1617
1618         if (val < vsk->buffer_min_size)
1619                 val = vsk->buffer_min_size;
1620
1621         if (val != vsk->buffer_size &&
1622             transport && transport->notify_buffer_size)
1623                 transport->notify_buffer_size(vsk, &val);
1624
1625         vsk->buffer_size = val;
1626 }
1627
1628 static int vsock_connectible_setsockopt(struct socket *sock,
1629                                         int level,
1630                                         int optname,
1631                                         sockptr_t optval,
1632                                         unsigned int optlen)
1633 {
1634         int err;
1635         struct sock *sk;
1636         struct vsock_sock *vsk;
1637         const struct vsock_transport *transport;
1638         u64 val;
1639
1640         if (level != AF_VSOCK)
1641                 return -ENOPROTOOPT;
1642
1643 #define COPY_IN(_v)                                       \
1644         do {                                              \
1645                 if (optlen < sizeof(_v)) {                \
1646                         err = -EINVAL;                    \
1647                         goto exit;                        \
1648                 }                                         \
1649                 if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {  \
1650                         err = -EFAULT;                                  \
1651                         goto exit;                                      \
1652                 }                                                       \
1653         } while (0)
1654
1655         err = 0;
1656         sk = sock->sk;
1657         vsk = vsock_sk(sk);
1658
1659         lock_sock(sk);
1660
1661         transport = vsk->transport;
1662
1663         switch (optname) {
1664         case SO_VM_SOCKETS_BUFFER_SIZE:
1665                 COPY_IN(val);
1666                 vsock_update_buffer_size(vsk, transport, val);
1667                 break;
1668
1669         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1670                 COPY_IN(val);
1671                 vsk->buffer_max_size = val;
1672                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1673                 break;
1674
1675         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1676                 COPY_IN(val);
1677                 vsk->buffer_min_size = val;
1678                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1679                 break;
1680
1681         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1682         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1683                 struct __kernel_sock_timeval tv;
1684
1685                 err = sock_copy_user_timeval(&tv, optval, optlen,
1686                                              optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1687                 if (err)
1688                         break;
1689                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1690                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1691                         vsk->connect_timeout = tv.tv_sec * HZ +
1692                                 DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1693                         if (vsk->connect_timeout == 0)
1694                                 vsk->connect_timeout =
1695                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1696
1697                 } else {
1698                         err = -ERANGE;
1699                 }
1700                 break;
1701         }
1702
1703         default:
1704                 err = -ENOPROTOOPT;
1705                 break;
1706         }
1707
1708 #undef COPY_IN
1709
1710 exit:
1711         release_sock(sk);
1712         return err;
1713 }
1714
1715 static int vsock_connectible_getsockopt(struct socket *sock,
1716                                         int level, int optname,
1717                                         char __user *optval,
1718                                         int __user *optlen)
1719 {
1720         struct sock *sk = sock->sk;
1721         struct vsock_sock *vsk = vsock_sk(sk);
1722
1723         union {
1724                 u64 val64;
1725                 struct old_timeval32 tm32;
1726                 struct __kernel_old_timeval tm;
1727                 struct  __kernel_sock_timeval stm;
1728         } v;
1729
1730         int lv = sizeof(v.val64);
1731         int len;
1732
1733         if (level != AF_VSOCK)
1734                 return -ENOPROTOOPT;
1735
1736         if (get_user(len, optlen))
1737                 return -EFAULT;
1738
1739         memset(&v, 0, sizeof(v));
1740
1741         switch (optname) {
1742         case SO_VM_SOCKETS_BUFFER_SIZE:
1743                 v.val64 = vsk->buffer_size;
1744                 break;
1745
1746         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1747                 v.val64 = vsk->buffer_max_size;
1748                 break;
1749
1750         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1751                 v.val64 = vsk->buffer_min_size;
1752                 break;
1753
1754         case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1755         case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1756                 lv = sock_get_timeout(vsk->connect_timeout, &v,
1757                                       optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1758                 break;
1759
1760         default:
1761                 return -ENOPROTOOPT;
1762         }
1763
1764         if (len < lv)
1765                 return -EINVAL;
1766         if (len > lv)
1767                 len = lv;
1768         if (copy_to_user(optval, &v, len))
1769                 return -EFAULT;
1770
1771         if (put_user(len, optlen))
1772                 return -EFAULT;
1773
1774         return 0;
1775 }
1776
1777 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1778                                      size_t len)
1779 {
1780         struct sock *sk;
1781         struct vsock_sock *vsk;
1782         const struct vsock_transport *transport;
1783         ssize_t total_written;
1784         long timeout;
1785         int err;
1786         struct vsock_transport_send_notify_data send_data;
1787         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1788
1789         sk = sock->sk;
1790         vsk = vsock_sk(sk);
1791         total_written = 0;
1792         err = 0;
1793
1794         if (msg->msg_flags & MSG_OOB)
1795                 return -EOPNOTSUPP;
1796
1797         lock_sock(sk);
1798
1799         transport = vsk->transport;
1800
1801         /* Callers should not provide a destination with connection oriented
1802          * sockets.
1803          */
1804         if (msg->msg_namelen) {
1805                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1806                 goto out;
1807         }
1808
1809         /* Send data only if both sides are not shutdown in the direction. */
1810         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1811             vsk->peer_shutdown & RCV_SHUTDOWN) {
1812                 err = -EPIPE;
1813                 goto out;
1814         }
1815
1816         if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1817             !vsock_addr_bound(&vsk->local_addr)) {
1818                 err = -ENOTCONN;
1819                 goto out;
1820         }
1821
1822         if (!vsock_addr_bound(&vsk->remote_addr)) {
1823                 err = -EDESTADDRREQ;
1824                 goto out;
1825         }
1826
1827         /* Wait for room in the produce queue to enqueue our user's data. */
1828         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1829
1830         err = transport->notify_send_init(vsk, &send_data);
1831         if (err < 0)
1832                 goto out;
1833
1834         while (total_written < len) {
1835                 ssize_t written;
1836
1837                 add_wait_queue(sk_sleep(sk), &wait);
1838                 while (vsock_stream_has_space(vsk) == 0 &&
1839                        sk->sk_err == 0 &&
1840                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1841                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1842
1843                         /* Don't wait for non-blocking sockets. */
1844                         if (timeout == 0) {
1845                                 err = -EAGAIN;
1846                                 remove_wait_queue(sk_sleep(sk), &wait);
1847                                 goto out_err;
1848                         }
1849
1850                         err = transport->notify_send_pre_block(vsk, &send_data);
1851                         if (err < 0) {
1852                                 remove_wait_queue(sk_sleep(sk), &wait);
1853                                 goto out_err;
1854                         }
1855
1856                         release_sock(sk);
1857                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1858                         lock_sock(sk);
1859                         if (signal_pending(current)) {
1860                                 err = sock_intr_errno(timeout);
1861                                 remove_wait_queue(sk_sleep(sk), &wait);
1862                                 goto out_err;
1863                         } else if (timeout == 0) {
1864                                 err = -EAGAIN;
1865                                 remove_wait_queue(sk_sleep(sk), &wait);
1866                                 goto out_err;
1867                         }
1868                 }
1869                 remove_wait_queue(sk_sleep(sk), &wait);
1870
1871                 /* These checks occur both as part of and after the loop
1872                  * conditional since we need to check before and after
1873                  * sleeping.
1874                  */
1875                 if (sk->sk_err) {
1876                         err = -sk->sk_err;
1877                         goto out_err;
1878                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1879                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1880                         err = -EPIPE;
1881                         goto out_err;
1882                 }
1883
1884                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1885                 if (err < 0)
1886                         goto out_err;
1887
1888                 /* Note that enqueue will only write as many bytes as are free
1889                  * in the produce queue, so we don't need to ensure len is
1890                  * smaller than the queue size.  It is the caller's
1891                  * responsibility to check how many bytes we were able to send.
1892                  */
1893
1894                 if (sk->sk_type == SOCK_SEQPACKET) {
1895                         written = transport->seqpacket_enqueue(vsk,
1896                                                 msg, len - total_written);
1897                 } else {
1898                         written = transport->stream_enqueue(vsk,
1899                                         msg, len - total_written);
1900                 }
1901
1902                 if (written < 0) {
1903                         err = written;
1904                         goto out_err;
1905                 }
1906
1907                 total_written += written;
1908
1909                 err = transport->notify_send_post_enqueue(
1910                                 vsk, written, &send_data);
1911                 if (err < 0)
1912                         goto out_err;
1913
1914         }
1915
1916 out_err:
1917         if (total_written > 0) {
1918                 /* Return number of written bytes only if:
1919                  * 1) SOCK_STREAM socket.
1920                  * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1921                  */
1922                 if (sk->sk_type == SOCK_STREAM || total_written == len)
1923                         err = total_written;
1924         }
1925 out:
1926         release_sock(sk);
1927         return err;
1928 }
1929
1930 static int vsock_connectible_wait_data(struct sock *sk,
1931                                        struct wait_queue_entry *wait,
1932                                        long timeout,
1933                                        struct vsock_transport_recv_notify_data *recv_data,
1934                                        size_t target)
1935 {
1936         const struct vsock_transport *transport;
1937         struct vsock_sock *vsk;
1938         s64 data;
1939         int err;
1940
1941         vsk = vsock_sk(sk);
1942         err = 0;
1943         transport = vsk->transport;
1944
1945         while (1) {
1946                 prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1947                 data = vsock_connectible_has_data(vsk);
1948                 if (data != 0)
1949                         break;
1950
1951                 if (sk->sk_err != 0 ||
1952                     (sk->sk_shutdown & RCV_SHUTDOWN) ||
1953                     (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1954                         break;
1955                 }
1956
1957                 /* Don't wait for non-blocking sockets. */
1958                 if (timeout == 0) {
1959                         err = -EAGAIN;
1960                         break;
1961                 }
1962
1963                 if (recv_data) {
1964                         err = transport->notify_recv_pre_block(vsk, target, recv_data);
1965                         if (err < 0)
1966                                 break;
1967                 }
1968
1969                 release_sock(sk);
1970                 timeout = schedule_timeout(timeout);
1971                 lock_sock(sk);
1972
1973                 if (signal_pending(current)) {
1974                         err = sock_intr_errno(timeout);
1975                         break;
1976                 } else if (timeout == 0) {
1977                         err = -EAGAIN;
1978                         break;
1979                 }
1980         }
1981
1982         finish_wait(sk_sleep(sk), wait);
1983
1984         if (err)
1985                 return err;
1986
1987         /* Internal transport error when checking for available
1988          * data. XXX This should be changed to a connection
1989          * reset in a later change.
1990          */
1991         if (data < 0)
1992                 return -ENOMEM;
1993
1994         return data;
1995 }
1996
1997 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1998                                   size_t len, int flags)
1999 {
2000         struct vsock_transport_recv_notify_data recv_data;
2001         const struct vsock_transport *transport;
2002         struct vsock_sock *vsk;
2003         ssize_t copied;
2004         size_t target;
2005         long timeout;
2006         int err;
2007
2008         DEFINE_WAIT(wait);
2009
2010         vsk = vsock_sk(sk);
2011         transport = vsk->transport;
2012
2013         /* We must not copy less than target bytes into the user's buffer
2014          * before returning successfully, so we wait for the consume queue to
2015          * have that much data to consume before dequeueing.  Note that this
2016          * makes it impossible to handle cases where target is greater than the
2017          * queue size.
2018          */
2019         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2020         if (target >= transport->stream_rcvhiwat(vsk)) {
2021                 err = -ENOMEM;
2022                 goto out;
2023         }
2024         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2025         copied = 0;
2026
2027         err = transport->notify_recv_init(vsk, target, &recv_data);
2028         if (err < 0)
2029                 goto out;
2030
2031
2032         while (1) {
2033                 ssize_t read;
2034
2035                 err = vsock_connectible_wait_data(sk, &wait, timeout,
2036                                                   &recv_data, target);
2037                 if (err <= 0)
2038                         break;
2039
2040                 err = transport->notify_recv_pre_dequeue(vsk, target,
2041                                                          &recv_data);
2042                 if (err < 0)
2043                         break;
2044
2045                 read = transport->stream_dequeue(vsk, msg, len - copied, flags);
2046                 if (read < 0) {
2047                         err = read;
2048                         break;
2049                 }
2050
2051                 copied += read;
2052
2053                 err = transport->notify_recv_post_dequeue(vsk, target, read,
2054                                                 !(flags & MSG_PEEK), &recv_data);
2055                 if (err < 0)
2056                         goto out;
2057
2058                 if (read >= target || flags & MSG_PEEK)
2059                         break;
2060
2061                 target -= read;
2062         }
2063
2064         if (sk->sk_err)
2065                 err = -sk->sk_err;
2066         else if (sk->sk_shutdown & RCV_SHUTDOWN)
2067                 err = 0;
2068
2069         if (copied > 0)
2070                 err = copied;
2071
2072 out:
2073         return err;
2074 }
2075
2076 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2077                                      size_t len, int flags)
2078 {
2079         const struct vsock_transport *transport;
2080         struct vsock_sock *vsk;
2081         ssize_t msg_len;
2082         long timeout;
2083         int err = 0;
2084         DEFINE_WAIT(wait);
2085
2086         vsk = vsock_sk(sk);
2087         transport = vsk->transport;
2088
2089         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2090
2091         err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2092         if (err <= 0)
2093                 goto out;
2094
2095         msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2096
2097         if (msg_len < 0) {
2098                 err = msg_len;
2099                 goto out;
2100         }
2101
2102         if (sk->sk_err) {
2103                 err = -sk->sk_err;
2104         } else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2105                 err = 0;
2106         } else {
2107                 /* User sets MSG_TRUNC, so return real length of
2108                  * packet.
2109                  */
2110                 if (flags & MSG_TRUNC)
2111                         err = msg_len;
2112                 else
2113                         err = len - msg_data_left(msg);
2114
2115                 /* Always set MSG_TRUNC if real length of packet is
2116                  * bigger than user's buffer.
2117                  */
2118                 if (msg_len > len)
2119                         msg->msg_flags |= MSG_TRUNC;
2120         }
2121
2122 out:
2123         return err;
2124 }
2125
2126 int
2127 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2128                           int flags)
2129 {
2130         struct sock *sk;
2131         struct vsock_sock *vsk;
2132         const struct vsock_transport *transport;
2133 #ifdef CONFIG_BPF_SYSCALL
2134         const struct proto *prot;
2135 #endif
2136         int err;
2137
2138         sk = sock->sk;
2139
2140         if (unlikely(flags & MSG_ERRQUEUE))
2141                 return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, VSOCK_RECVERR);
2142
2143         vsk = vsock_sk(sk);
2144         err = 0;
2145
2146         lock_sock(sk);
2147
2148         transport = vsk->transport;
2149
2150         if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2151                 /* Recvmsg is supposed to return 0 if a peer performs an
2152                  * orderly shutdown. Differentiate between that case and when a
2153                  * peer has not connected or a local shutdown occurred with the
2154                  * SOCK_DONE flag.
2155                  */
2156                 if (sock_flag(sk, SOCK_DONE))
2157                         err = 0;
2158                 else
2159                         err = -ENOTCONN;
2160
2161                 goto out;
2162         }
2163
2164         if (flags & MSG_OOB) {
2165                 err = -EOPNOTSUPP;
2166                 goto out;
2167         }
2168
2169         /* We don't check peer_shutdown flag here since peer may actually shut
2170          * down, but there can be data in the queue that a local socket can
2171          * receive.
2172          */
2173         if (sk->sk_shutdown & RCV_SHUTDOWN) {
2174                 err = 0;
2175                 goto out;
2176         }
2177
2178         /* It is valid on Linux to pass in a zero-length receive buffer.  This
2179          * is not an error.  We may as well bail out now.
2180          */
2181         if (!len) {
2182                 err = 0;
2183                 goto out;
2184         }
2185
2186 #ifdef CONFIG_BPF_SYSCALL
2187         prot = READ_ONCE(sk->sk_prot);
2188         if (prot != &vsock_proto) {
2189                 release_sock(sk);
2190                 return prot->recvmsg(sk, msg, len, flags, NULL);
2191         }
2192 #endif
2193
2194         if (sk->sk_type == SOCK_STREAM)
2195                 err = __vsock_stream_recvmsg(sk, msg, len, flags);
2196         else
2197                 err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2198
2199 out:
2200         release_sock(sk);
2201         return err;
2202 }
2203 EXPORT_SYMBOL_GPL(vsock_connectible_recvmsg);
2204
2205 static int vsock_set_rcvlowat(struct sock *sk, int val)
2206 {
2207         const struct vsock_transport *transport;
2208         struct vsock_sock *vsk;
2209
2210         vsk = vsock_sk(sk);
2211
2212         if (val > vsk->buffer_size)
2213                 return -EINVAL;
2214
2215         transport = vsk->transport;
2216
2217         if (transport && transport->set_rcvlowat)
2218                 return transport->set_rcvlowat(vsk, val);
2219
2220         WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
2221         return 0;
2222 }
2223
2224 static const struct proto_ops vsock_stream_ops = {
2225         .family = PF_VSOCK,
2226         .owner = THIS_MODULE,
2227         .release = vsock_release,
2228         .bind = vsock_bind,
2229         .connect = vsock_connect,
2230         .socketpair = sock_no_socketpair,
2231         .accept = vsock_accept,
2232         .getname = vsock_getname,
2233         .poll = vsock_poll,
2234         .ioctl = sock_no_ioctl,
2235         .listen = vsock_listen,
2236         .shutdown = vsock_shutdown,
2237         .setsockopt = vsock_connectible_setsockopt,
2238         .getsockopt = vsock_connectible_getsockopt,
2239         .sendmsg = vsock_connectible_sendmsg,
2240         .recvmsg = vsock_connectible_recvmsg,
2241         .mmap = sock_no_mmap,
2242         .set_rcvlowat = vsock_set_rcvlowat,
2243         .read_skb = vsock_read_skb,
2244 };
2245
2246 static const struct proto_ops vsock_seqpacket_ops = {
2247         .family = PF_VSOCK,
2248         .owner = THIS_MODULE,
2249         .release = vsock_release,
2250         .bind = vsock_bind,
2251         .connect = vsock_connect,
2252         .socketpair = sock_no_socketpair,
2253         .accept = vsock_accept,
2254         .getname = vsock_getname,
2255         .poll = vsock_poll,
2256         .ioctl = sock_no_ioctl,
2257         .listen = vsock_listen,
2258         .shutdown = vsock_shutdown,
2259         .setsockopt = vsock_connectible_setsockopt,
2260         .getsockopt = vsock_connectible_getsockopt,
2261         .sendmsg = vsock_connectible_sendmsg,
2262         .recvmsg = vsock_connectible_recvmsg,
2263         .mmap = sock_no_mmap,
2264         .read_skb = vsock_read_skb,
2265 };
2266
2267 static int vsock_create(struct net *net, struct socket *sock,
2268                         int protocol, int kern)
2269 {
2270         struct vsock_sock *vsk;
2271         struct sock *sk;
2272         int ret;
2273
2274         if (!sock)
2275                 return -EINVAL;
2276
2277         if (protocol && protocol != PF_VSOCK)
2278                 return -EPROTONOSUPPORT;
2279
2280         switch (sock->type) {
2281         case SOCK_DGRAM:
2282                 sock->ops = &vsock_dgram_ops;
2283                 break;
2284         case SOCK_STREAM:
2285                 sock->ops = &vsock_stream_ops;
2286                 break;
2287         case SOCK_SEQPACKET:
2288                 sock->ops = &vsock_seqpacket_ops;
2289                 break;
2290         default:
2291                 return -ESOCKTNOSUPPORT;
2292         }
2293
2294         sock->state = SS_UNCONNECTED;
2295
2296         sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2297         if (!sk)
2298                 return -ENOMEM;
2299
2300         vsk = vsock_sk(sk);
2301
2302         if (sock->type == SOCK_DGRAM) {
2303                 ret = vsock_assign_transport(vsk, NULL);
2304                 if (ret < 0) {
2305                         sock_put(sk);
2306                         return ret;
2307                 }
2308         }
2309
2310         vsock_insert_unbound(vsk);
2311
2312         return 0;
2313 }
2314
2315 static const struct net_proto_family vsock_family_ops = {
2316         .family = AF_VSOCK,
2317         .create = vsock_create,
2318         .owner = THIS_MODULE,
2319 };
2320
2321 static long vsock_dev_do_ioctl(struct file *filp,
2322                                unsigned int cmd, void __user *ptr)
2323 {
2324         u32 __user *p = ptr;
2325         u32 cid = VMADDR_CID_ANY;
2326         int retval = 0;
2327
2328         switch (cmd) {
2329         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2330                 /* To be compatible with the VMCI behavior, we prioritize the
2331                  * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2332                  */
2333                 if (transport_g2h)
2334                         cid = transport_g2h->get_local_cid();
2335                 else if (transport_h2g)
2336                         cid = transport_h2g->get_local_cid();
2337
2338                 if (put_user(cid, p) != 0)
2339                         retval = -EFAULT;
2340                 break;
2341
2342         default:
2343                 retval = -ENOIOCTLCMD;
2344         }
2345
2346         return retval;
2347 }
2348
2349 static long vsock_dev_ioctl(struct file *filp,
2350                             unsigned int cmd, unsigned long arg)
2351 {
2352         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2353 }
2354
2355 #ifdef CONFIG_COMPAT
2356 static long vsock_dev_compat_ioctl(struct file *filp,
2357                                    unsigned int cmd, unsigned long arg)
2358 {
2359         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2360 }
2361 #endif
2362
2363 static const struct file_operations vsock_device_ops = {
2364         .owner          = THIS_MODULE,
2365         .unlocked_ioctl = vsock_dev_ioctl,
2366 #ifdef CONFIG_COMPAT
2367         .compat_ioctl   = vsock_dev_compat_ioctl,
2368 #endif
2369         .open           = nonseekable_open,
2370 };
2371
2372 static struct miscdevice vsock_device = {
2373         .name           = "vsock",
2374         .fops           = &vsock_device_ops,
2375 };
2376
2377 static int __init vsock_init(void)
2378 {
2379         int err = 0;
2380
2381         vsock_init_tables();
2382
2383         vsock_proto.owner = THIS_MODULE;
2384         vsock_device.minor = MISC_DYNAMIC_MINOR;
2385         err = misc_register(&vsock_device);
2386         if (err) {
2387                 pr_err("Failed to register misc device\n");
2388                 goto err_reset_transport;
2389         }
2390
2391         err = proto_register(&vsock_proto, 1);  /* we want our slab */
2392         if (err) {
2393                 pr_err("Cannot register vsock protocol\n");
2394                 goto err_deregister_misc;
2395         }
2396
2397         err = sock_register(&vsock_family_ops);
2398         if (err) {
2399                 pr_err("could not register af_vsock (%d) address family: %d\n",
2400                        AF_VSOCK, err);
2401                 goto err_unregister_proto;
2402         }
2403
2404         vsock_bpf_build_proto();
2405
2406         return 0;
2407
2408 err_unregister_proto:
2409         proto_unregister(&vsock_proto);
2410 err_deregister_misc:
2411         misc_deregister(&vsock_device);
2412 err_reset_transport:
2413         return err;
2414 }
2415
2416 static void __exit vsock_exit(void)
2417 {
2418         misc_deregister(&vsock_device);
2419         sock_unregister(AF_VSOCK);
2420         proto_unregister(&vsock_proto);
2421 }
2422
2423 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2424 {
2425         return vsk->transport;
2426 }
2427 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2428
2429 int vsock_core_register(const struct vsock_transport *t, int features)
2430 {
2431         const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2432         int err = mutex_lock_interruptible(&vsock_register_mutex);
2433
2434         if (err)
2435                 return err;
2436
2437         t_h2g = transport_h2g;
2438         t_g2h = transport_g2h;
2439         t_dgram = transport_dgram;
2440         t_local = transport_local;
2441
2442         if (features & VSOCK_TRANSPORT_F_H2G) {
2443                 if (t_h2g) {
2444                         err = -EBUSY;
2445                         goto err_busy;
2446                 }
2447                 t_h2g = t;
2448         }
2449
2450         if (features & VSOCK_TRANSPORT_F_G2H) {
2451                 if (t_g2h) {
2452                         err = -EBUSY;
2453                         goto err_busy;
2454                 }
2455                 t_g2h = t;
2456         }
2457
2458         if (features & VSOCK_TRANSPORT_F_DGRAM) {
2459                 if (t_dgram) {
2460                         err = -EBUSY;
2461                         goto err_busy;
2462                 }
2463                 t_dgram = t;
2464         }
2465
2466         if (features & VSOCK_TRANSPORT_F_LOCAL) {
2467                 if (t_local) {
2468                         err = -EBUSY;
2469                         goto err_busy;
2470                 }
2471                 t_local = t;
2472         }
2473
2474         transport_h2g = t_h2g;
2475         transport_g2h = t_g2h;
2476         transport_dgram = t_dgram;
2477         transport_local = t_local;
2478
2479 err_busy:
2480         mutex_unlock(&vsock_register_mutex);
2481         return err;
2482 }
2483 EXPORT_SYMBOL_GPL(vsock_core_register);
2484
2485 void vsock_core_unregister(const struct vsock_transport *t)
2486 {
2487         mutex_lock(&vsock_register_mutex);
2488
2489         if (transport_h2g == t)
2490                 transport_h2g = NULL;
2491
2492         if (transport_g2h == t)
2493                 transport_g2h = NULL;
2494
2495         if (transport_dgram == t)
2496                 transport_dgram = NULL;
2497
2498         if (transport_local == t)
2499                 transport_local = NULL;
2500
2501         mutex_unlock(&vsock_register_mutex);
2502 }
2503 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2504
2505 module_init(vsock_init);
2506 module_exit(vsock_exit);
2507
2508 MODULE_AUTHOR("VMware, Inc.");
2509 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2510 MODULE_VERSION("1.0.2.0-k");
2511 MODULE_LICENSE("GPL v2");