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/types.h>
  89 #include <linux/bitops.h>
  90 #include <linux/cred.h>
  91 #include <linux/init.h>
  92 #include <linux/io.h>
  93 #include <linux/kernel.h>
  94 #include <linux/sched/signal.h>
  95 #include <linux/kmod.h>
  96 #include <linux/list.h>
  97 #include <linux/miscdevice.h>
  98 #include <linux/module.h>
  99 #include <linux/mutex.h>
 100 #include <linux/net.h>
 101 #include <linux/poll.h>
 102 #include <linux/random.h>
 103 #include <linux/skbuff.h>
 104 #include <linux/smp.h>
 105 #include <linux/socket.h>
 106 #include <linux/stddef.h>
 107 #include <linux/unistd.h>
 108 #include <linux/wait.h>
 109 #include <linux/workqueue.h>
 110 #include <net/sock.h>
 111 #include <net/af_vsock.h>
 112
 113 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 114 static void vsock_sk_destruct(struct sock *sk);
 115 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 116
 117 /* Protocol family. */
 118 static struct proto vsock_proto = {
 119         .name = "AF_VSOCK",
 120         .owner = THIS_MODULE,
 121         .obj_size = sizeof(struct vsock_sock),
 122 };
 123
 124 /* The default peer timeout indicates how long we will wait for a peer response
 125  * to a control message.
 126  */
 127 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
 128
 129 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
 130 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
 131 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
 132
 133 /* Transport used for host->guest communication */
 134 static const struct vsock_transport *transport_h2g;
 135 /* Transport used for guest->host communication */
 136 static const struct vsock_transport *transport_g2h;
 137 /* Transport used for DGRAM communication */
 138 static const struct vsock_transport *transport_dgram;
 139 /* Transport used for local communication */
 140 static const struct vsock_transport *transport_local;
 141 static DEFINE_MUTEX(vsock_register_mutex);
 142
 143 /**** UTILS ****/
 144
 145 /* Each bound VSocket is stored in the bind hash table and each connected
 146  * VSocket is stored in the connected hash table.
 147  *
 148  * Unbound sockets are all put on the same list attached to the end of the hash
 149  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
 150  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
 151  * represents the list that addr hashes to).
 152  *
 153  * Specifically, we initialize the vsock_bind_table array to a size of
 154  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
 155  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
 156  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
 157  * mods with VSOCK_HASH_SIZE to ensure this.
 158  */
 159 #define MAX_PORT_RETRIES        24
 160
 161 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
 162 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
 163 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
 164
 165 /* XXX This can probably be implemented in a better way. */
 166 #define VSOCK_CONN_HASH(src, dst)                               \
 167         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
 168 #define vsock_connected_sockets(src, dst)               \
 169         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
 170 #define vsock_connected_sockets_vsk(vsk)                                \
 171         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
 172
 173 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
 174 EXPORT_SYMBOL_GPL(vsock_bind_table);
 175 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
 176 EXPORT_SYMBOL_GPL(vsock_connected_table);
 177 DEFINE_SPINLOCK(vsock_table_lock);
 178 EXPORT_SYMBOL_GPL(vsock_table_lock);
 179
 180 /* Autobind this socket to the local address if necessary. */
 181 static int vsock_auto_bind(struct vsock_sock *vsk)
 182 {
 183         struct sock *sk = sk_vsock(vsk);
 184         struct sockaddr_vm local_addr;
 185
 186         if (vsock_addr_bound(&vsk->local_addr))
 187                 return 0;
 188         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 189         return __vsock_bind(sk, &local_addr);
 190 }
 191
 192 static void vsock_init_tables(void)
 193 {
 194         int i;
 195
 196         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
 197                 INIT_LIST_HEAD(&vsock_bind_table[i]);
 198
 199         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
 200                 INIT_LIST_HEAD(&vsock_connected_table[i]);
 201 }
 202
 203 static void __vsock_insert_bound(struct list_head *list,
 204                                  struct vsock_sock *vsk)
 205 {
 206         sock_hold(&vsk->sk);
 207         list_add(&vsk->bound_table, list);
 208 }
 209
 210 static void __vsock_insert_connected(struct list_head *list,
 211                                      struct vsock_sock *vsk)
 212 {
 213         sock_hold(&vsk->sk);
 214         list_add(&vsk->connected_table, list);
 215 }
 216
 217 static void __vsock_remove_bound(struct vsock_sock *vsk)
 218 {
 219         list_del_init(&vsk->bound_table);
 220         sock_put(&vsk->sk);
 221 }
 222
 223 static void __vsock_remove_connected(struct vsock_sock *vsk)
 224 {
 225         list_del_init(&vsk->connected_table);
 226         sock_put(&vsk->sk);
 227 }
 228
 229 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
 230 {
 231         struct vsock_sock *vsk;
 232
 233         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
 234                 if (vsock_addr_equals_addr(addr, &vsk->local_addr))
 235                         return sk_vsock(vsk);
 236
 237                 if (addr->svm_port == vsk->local_addr.svm_port &&
 238                     (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
 239                      addr->svm_cid == VMADDR_CID_ANY))
 240                         return sk_vsock(vsk);
 241         }
 242
 243         return NULL;
 244 }
 245
 246 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
 247                                                   struct sockaddr_vm *dst)
 248 {
 249         struct vsock_sock *vsk;
 250
 251         list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
 252                             connected_table) {
 253                 if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
 254                     dst->svm_port == vsk->local_addr.svm_port) {
 255                         return sk_vsock(vsk);
 256                 }
 257         }
 258
 259         return NULL;
 260 }
 261
 262 static void vsock_insert_unbound(struct vsock_sock *vsk)
 263 {
 264         spin_lock_bh(&vsock_table_lock);
 265         __vsock_insert_bound(vsock_unbound_sockets, vsk);
 266         spin_unlock_bh(&vsock_table_lock);
 267 }
 268
 269 void vsock_insert_connected(struct vsock_sock *vsk)
 270 {
 271         struct list_head *list = vsock_connected_sockets(
 272                 &vsk->remote_addr, &vsk->local_addr);
 273
 274         spin_lock_bh(&vsock_table_lock);
 275         __vsock_insert_connected(list, vsk);
 276         spin_unlock_bh(&vsock_table_lock);
 277 }
 278 EXPORT_SYMBOL_GPL(vsock_insert_connected);
 279
 280 void vsock_remove_bound(struct vsock_sock *vsk)
 281 {
 282         spin_lock_bh(&vsock_table_lock);
 283         if (__vsock_in_bound_table(vsk))
 284                 __vsock_remove_bound(vsk);
 285         spin_unlock_bh(&vsock_table_lock);
 286 }
 287 EXPORT_SYMBOL_GPL(vsock_remove_bound);
 288
 289 void vsock_remove_connected(struct vsock_sock *vsk)
 290 {
 291         spin_lock_bh(&vsock_table_lock);
 292         if (__vsock_in_connected_table(vsk))
 293                 __vsock_remove_connected(vsk);
 294         spin_unlock_bh(&vsock_table_lock);
 295 }
 296 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 297
 298 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 299 {
 300         struct sock *sk;
 301
 302         spin_lock_bh(&vsock_table_lock);
 303         sk = __vsock_find_bound_socket(addr);
 304         if (sk)
 305                 sock_hold(sk);
 306
 307         spin_unlock_bh(&vsock_table_lock);
 308
 309         return sk;
 310 }
 311 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 312
 313 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 314                                          struct sockaddr_vm *dst)
 315 {
 316         struct sock *sk;
 317
 318         spin_lock_bh(&vsock_table_lock);
 319         sk = __vsock_find_connected_socket(src, dst);
 320         if (sk)
 321                 sock_hold(sk);
 322
 323         spin_unlock_bh(&vsock_table_lock);
 324
 325         return sk;
 326 }
 327 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 328
 329 void vsock_remove_sock(struct vsock_sock *vsk)
 330 {
 331         vsock_remove_bound(vsk);
 332         vsock_remove_connected(vsk);
 333 }
 334 EXPORT_SYMBOL_GPL(vsock_remove_sock);
 335
 336 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
 337 {
 338         int i;
 339
 340         spin_lock_bh(&vsock_table_lock);
 341
 342         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
 343                 struct vsock_sock *vsk;
 344                 list_for_each_entry(vsk, &vsock_connected_table[i],
 345                                     connected_table)
 346                         fn(sk_vsock(vsk));
 347         }
 348
 349         spin_unlock_bh(&vsock_table_lock);
 350 }
 351 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
 352
 353 void vsock_add_pending(struct sock *listener, struct sock *pending)
 354 {
 355         struct vsock_sock *vlistener;
 356         struct vsock_sock *vpending;
 357
 358         vlistener = vsock_sk(listener);
 359         vpending = vsock_sk(pending);
 360
 361         sock_hold(pending);
 362         sock_hold(listener);
 363         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 364 }
 365 EXPORT_SYMBOL_GPL(vsock_add_pending);
 366
 367 void vsock_remove_pending(struct sock *listener, struct sock *pending)
 368 {
 369         struct vsock_sock *vpending = vsock_sk(pending);
 370
 371         list_del_init(&vpending->pending_links);
 372         sock_put(listener);
 373         sock_put(pending);
 374 }
 375 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 376
 377 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 378 {
 379         struct vsock_sock *vlistener;
 380         struct vsock_sock *vconnected;
 381
 382         vlistener = vsock_sk(listener);
 383         vconnected = vsock_sk(connected);
 384
 385         sock_hold(connected);
 386         sock_hold(listener);
 387         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 388 }
 389 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 390
 391 static bool vsock_use_local_transport(unsigned int remote_cid)
 392 {
 393         if (!transport_local)
 394                 return false;
 395
 396         if (remote_cid == VMADDR_CID_LOCAL)
 397                 return true;
 398
 399         if (transport_g2h) {
 400                 return remote_cid == transport_g2h->get_local_cid();
 401         } else {
 402                 return remote_cid == VMADDR_CID_HOST;
 403         }
 404 }
 405
 406 static void vsock_deassign_transport(struct vsock_sock *vsk)
 407 {
 408         if (!vsk->transport)
 409                 return;
 410
 411         vsk->transport->destruct(vsk);
 412         module_put(vsk->transport->module);
 413         vsk->transport = NULL;
 414 }
 415
 416 /* Assign a transport to a socket and call the .init transport callback.
 417  *
 418  * Note: for stream socket this must be called when vsk->remote_addr is set
 419  * (e.g. during the connect() or when a connection request on a listener
 420  * socket is received).
 421  * The vsk->remote_addr is used to decide which transport to use:
 422  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 423  *    g2h is not loaded, will use local transport;
 424  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 425  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 426  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 427  */
 428 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 429 {
 430         const struct vsock_transport *new_transport;
 431         struct sock *sk = sk_vsock(vsk);
 432         unsigned int remote_cid = vsk->remote_addr.svm_cid;
 433         __u8 remote_flags;
 434         int ret;
 435
 436         /* If the packet is coming with the source and destination CIDs higher
 437          * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 438          * forwarded to the host should be established. Then the host will
 439          * need to forward the packets to the guest.
 440          *
 441          * The flag is set on the (listen) receive path (psk is not NULL). On
 442          * the connect path the flag can be set by the user space application.
 443          */
 444         if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 445             vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 446                 vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 447
 448         remote_flags = vsk->remote_addr.svm_flags;
 449
 450         switch (sk->sk_type) {
 451         case SOCK_DGRAM:
 452                 new_transport = transport_dgram;
 453                 break;
 454         case SOCK_STREAM:
 455                 if (vsock_use_local_transport(remote_cid))
 456                         new_transport = transport_local;
 457                 else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 458                          (remote_flags & VMADDR_FLAG_TO_HOST))
 459                         new_transport = transport_g2h;
 460                 else
 461                         new_transport = transport_h2g;
 462                 break;
 463         default:
 464                 return -ESOCKTNOSUPPORT;
 465         }
 466
 467         if (vsk->transport) {
 468                 if (vsk->transport == new_transport)
 469                         return 0;
 470
 471                 /* transport->release() must be called with sock lock acquired.
 472                  * This path can only be taken during vsock_stream_connect(),
 473                  * where we have already held the sock lock.
 474                  * In the other cases, this function is called on a new socket
 475                  * which is not assigned to any transport.
 476                  */
 477                 vsk->transport->release(vsk);
 478                 vsock_deassign_transport(vsk);
 479         }
 480
 481         /* We increase the module refcnt to prevent the transport unloading
 482          * while there are open sockets assigned to it.
 483          */
 484         if (!new_transport || !try_module_get(new_transport->module))
 485                 return -ENODEV;
 486
 487         ret = new_transport->init(vsk, psk);
 488         if (ret) {
 489                 module_put(new_transport->module);
 490                 return ret;
 491         }
 492
 493         vsk->transport = new_transport;
 494
 495         return 0;
 496 }
 497 EXPORT_SYMBOL_GPL(vsock_assign_transport);
 498
 499 bool vsock_find_cid(unsigned int cid)
 500 {
 501         if (transport_g2h && cid == transport_g2h->get_local_cid())
 502                 return true;
 503
 504         if (transport_h2g && cid == VMADDR_CID_HOST)
 505                 return true;
 506
 507         if (transport_local && cid == VMADDR_CID_LOCAL)
 508                 return true;
 509
 510         return false;
 511 }
 512 EXPORT_SYMBOL_GPL(vsock_find_cid);
 513
 514 static struct sock *vsock_dequeue_accept(struct sock *listener)
 515 {
 516         struct vsock_sock *vlistener;
 517         struct vsock_sock *vconnected;
 518
 519         vlistener = vsock_sk(listener);
 520
 521         if (list_empty(&vlistener->accept_queue))
 522                 return NULL;
 523
 524         vconnected = list_entry(vlistener->accept_queue.next,
 525                                 struct vsock_sock, accept_queue);
 526
 527         list_del_init(&vconnected->accept_queue);
 528         sock_put(listener);
 529         /* The caller will need a reference on the connected socket so we let
 530          * it call sock_put().
 531          */
 532
 533         return sk_vsock(vconnected);
 534 }
 535
 536 static bool vsock_is_accept_queue_empty(struct sock *sk)
 537 {
 538         struct vsock_sock *vsk = vsock_sk(sk);
 539         return list_empty(&vsk->accept_queue);
 540 }
 541
 542 static bool vsock_is_pending(struct sock *sk)
 543 {
 544         struct vsock_sock *vsk = vsock_sk(sk);
 545         return !list_empty(&vsk->pending_links);
 546 }
 547
 548 static int vsock_send_shutdown(struct sock *sk, int mode)
 549 {
 550         struct vsock_sock *vsk = vsock_sk(sk);
 551
 552         if (!vsk->transport)
 553                 return -ENODEV;
 554
 555         return vsk->transport->shutdown(vsk, mode);
 556 }
 557
 558 static void vsock_pending_work(struct work_struct *work)
 559 {
 560         struct sock *sk;
 561         struct sock *listener;
 562         struct vsock_sock *vsk;
 563         bool cleanup;
 564
 565         vsk = container_of(work, struct vsock_sock, pending_work.work);
 566         sk = sk_vsock(vsk);
 567         listener = vsk->listener;
 568         cleanup = true;
 569
 570         lock_sock(listener);
 571         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 572
 573         if (vsock_is_pending(sk)) {
 574                 vsock_remove_pending(listener, sk);
 575
 576                 sk_acceptq_removed(listener);
 577         } else if (!vsk->rejected) {
 578                 /* We are not on the pending list and accept() did not reject
 579                  * us, so we must have been accepted by our user process.  We
 580                  * just need to drop our references to the sockets and be on
 581                  * our way.
 582                  */
 583                 cleanup = false;
 584                 goto out;
 585         }
 586
 587         /* We need to remove ourself from the global connected sockets list so
 588          * incoming packets can't find this socket, and to reduce the reference
 589          * count.
 590          */
 591         vsock_remove_connected(vsk);
 592
 593         sk->sk_state = TCP_CLOSE;
 594
 595 out:
 596         release_sock(sk);
 597         release_sock(listener);
 598         if (cleanup)
 599                 sock_put(sk);
 600
 601         sock_put(sk);
 602         sock_put(listener);
 603 }
 604
 605 /**** SOCKET OPERATIONS ****/
 606
 607 static int __vsock_bind_stream(struct vsock_sock *vsk,
 608                                struct sockaddr_vm *addr)
 609 {
 610         static u32 port;
 611         struct sockaddr_vm new_addr;
 612
 613         if (!port)
 614                 port = LAST_RESERVED_PORT + 1 +
 615                         prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
 616
 617         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 618
 619         if (addr->svm_port == VMADDR_PORT_ANY) {
 620                 bool found = false;
 621                 unsigned int i;
 622
 623                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
 624                         if (port <= LAST_RESERVED_PORT)
 625                                 port = LAST_RESERVED_PORT + 1;
 626
 627                         new_addr.svm_port = port++;
 628
 629                         if (!__vsock_find_bound_socket(&new_addr)) {
 630                                 found = true;
 631                                 break;
 632                         }
 633                 }
 634
 635                 if (!found)
 636                         return -EADDRNOTAVAIL;
 637         } else {
 638                 /* If port is in reserved range, ensure caller
 639                  * has necessary privileges.
 640                  */
 641                 if (addr->svm_port <= LAST_RESERVED_PORT &&
 642                     !capable(CAP_NET_BIND_SERVICE)) {
 643                         return -EACCES;
 644                 }
 645
 646                 if (__vsock_find_bound_socket(&new_addr))
 647                         return -EADDRINUSE;
 648         }
 649
 650         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
 651
 652         /* Remove stream sockets from the unbound list and add them to the hash
 653          * table for easy lookup by its address.  The unbound list is simply an
 654          * extra entry at the end of the hash table, a trick used by AF_UNIX.
 655          */
 656         __vsock_remove_bound(vsk);
 657         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
 658
 659         return 0;
 660 }
 661
 662 static int __vsock_bind_dgram(struct vsock_sock *vsk,
 663                               struct sockaddr_vm *addr)
 664 {
 665         return vsk->transport->dgram_bind(vsk, addr);
 666 }
 667
 668 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 669 {
 670         struct vsock_sock *vsk = vsock_sk(sk);
 671         int retval;
 672
 673         /* First ensure this socket isn't already bound. */
 674         if (vsock_addr_bound(&vsk->local_addr))
 675                 return -EINVAL;
 676
 677         /* Now bind to the provided address or select appropriate values if
 678          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
 679          * like AF_INET prevents binding to a non-local IP address (in most
 680          * cases), we only allow binding to a local CID.
 681          */
 682         if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
 683                 return -EADDRNOTAVAIL;
 684
 685         switch (sk->sk_socket->type) {
 686         case SOCK_STREAM:
 687                 spin_lock_bh(&vsock_table_lock);
 688                 retval = __vsock_bind_stream(vsk, addr);
 689                 spin_unlock_bh(&vsock_table_lock);
 690                 break;
 691
 692         case SOCK_DGRAM:
 693                 retval = __vsock_bind_dgram(vsk, addr);
 694                 break;
 695
 696         default:
 697                 retval = -EINVAL;
 698                 break;
 699         }
 700
 701         return retval;
 702 }
 703
 704 static void vsock_connect_timeout(struct work_struct *work);
 705
 706 static struct sock *__vsock_create(struct net *net,
 707                                    struct socket *sock,
 708                                    struct sock *parent,
 709                                    gfp_t priority,
 710                                    unsigned short type,
 711                                    int kern)
 712 {
 713         struct sock *sk;
 714         struct vsock_sock *psk;
 715         struct vsock_sock *vsk;
 716
 717         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 718         if (!sk)
 719                 return NULL;
 720
 721         sock_init_data(sock, sk);
 722
 723         /* sk->sk_type is normally set in sock_init_data, but only if sock is
 724          * non-NULL. We make sure that our sockets always have a type by
 725          * setting it here if needed.
 726          */
 727         if (!sock)
 728                 sk->sk_type = type;
 729
 730         vsk = vsock_sk(sk);
 731         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 732         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 733
 734         sk->sk_destruct = vsock_sk_destruct;
 735         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 736         sock_reset_flag(sk, SOCK_DONE);
 737
 738         INIT_LIST_HEAD(&vsk->bound_table);
 739         INIT_LIST_HEAD(&vsk->connected_table);
 740         vsk->listener = NULL;
 741         INIT_LIST_HEAD(&vsk->pending_links);
 742         INIT_LIST_HEAD(&vsk->accept_queue);
 743         vsk->rejected = false;
 744         vsk->sent_request = false;
 745         vsk->ignore_connecting_rst = false;
 746         vsk->peer_shutdown = 0;
 747         INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 748         INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 749
 750         psk = parent ? vsock_sk(parent) : NULL;
 751         if (parent) {
 752                 vsk->trusted = psk->trusted;
 753                 vsk->owner = get_cred(psk->owner);
 754                 vsk->connect_timeout = psk->connect_timeout;
 755                 vsk->buffer_size = psk->buffer_size;
 756                 vsk->buffer_min_size = psk->buffer_min_size;
 757                 vsk->buffer_max_size = psk->buffer_max_size;
 758         } else {
 759                 vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
 760                 vsk->owner = get_current_cred();
 761                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 762                 vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
 763                 vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
 764                 vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
 765         }
 766
 767         return sk;
 768 }
 769
 770 static void __vsock_release(struct sock *sk, int level)
 771 {
 772         if (sk) {
 773                 struct sock *pending;
 774                 struct vsock_sock *vsk;
 775
 776                 vsk = vsock_sk(sk);
 777                 pending = NULL; /* Compiler warning. */
 778
 779                 /* When "level" is SINGLE_DEPTH_NESTING, use the nested
 780                  * version to avoid the warning "possible recursive locking
 781                  * detected". When "level" is 0, lock_sock_nested(sk, level)
 782                  * is the same as lock_sock(sk).
 783                  */
 784                 lock_sock_nested(sk, level);
 785
 786                 if (vsk->transport)
 787                         vsk->transport->release(vsk);
 788                 else if (sk->sk_type == SOCK_STREAM)
 789                         vsock_remove_sock(vsk);
 790
 791                 sock_orphan(sk);
 792                 sk->sk_shutdown = SHUTDOWN_MASK;
 793
 794                 skb_queue_purge(&sk->sk_receive_queue);
 795
 796                 /* Clean up any sockets that never were accepted. */
 797                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 798                         __vsock_release(pending, SINGLE_DEPTH_NESTING);
 799                         sock_put(pending);
 800                 }
 801
 802                 release_sock(sk);
 803                 sock_put(sk);
 804         }
 805 }
 806
 807 static void vsock_sk_destruct(struct sock *sk)
 808 {
 809         struct vsock_sock *vsk = vsock_sk(sk);
 810
 811         vsock_deassign_transport(vsk);
 812
 813         /* When clearing these addresses, there's no need to set the family and
 814          * possibly register the address family with the kernel.
 815          */
 816         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 817         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 818
 819         put_cred(vsk->owner);
 820 }
 821
 822 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 823 {
 824         int err;
 825
 826         err = sock_queue_rcv_skb(sk, skb);
 827         if (err)
 828                 kfree_skb(skb);
 829
 830         return err;
 831 }
 832
 833 struct sock *vsock_create_connected(struct sock *parent)
 834 {
 835         return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
 836                               parent->sk_type, 0);
 837 }
 838 EXPORT_SYMBOL_GPL(vsock_create_connected);
 839
 840 s64 vsock_stream_has_data(struct vsock_sock *vsk)
 841 {
 842         return vsk->transport->stream_has_data(vsk);
 843 }
 844 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 845
 846 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 847 {
 848         return vsk->transport->stream_has_space(vsk);
 849 }
 850 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
 851
 852 static int vsock_release(struct socket *sock)
 853 {
 854         __vsock_release(sock->sk, 0);
 855         sock->sk = NULL;
 856         sock->state = SS_FREE;
 857
 858         return 0;
 859 }
 860
 861 static int
 862 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 863 {
 864         int err;
 865         struct sock *sk;
 866         struct sockaddr_vm *vm_addr;
 867
 868         sk = sock->sk;
 869
 870         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
 871                 return -EINVAL;
 872
 873         lock_sock(sk);
 874         err = __vsock_bind(sk, vm_addr);
 875         release_sock(sk);
 876
 877         return err;
 878 }
 879
 880 static int vsock_getname(struct socket *sock,
 881                          struct sockaddr *addr, int peer)
 882 {
 883         int err;
 884         struct sock *sk;
 885         struct vsock_sock *vsk;
 886         struct sockaddr_vm *vm_addr;
 887
 888         sk = sock->sk;
 889         vsk = vsock_sk(sk);
 890         err = 0;
 891
 892         lock_sock(sk);
 893
 894         if (peer) {
 895                 if (sock->state != SS_CONNECTED) {
 896                         err = -ENOTCONN;
 897                         goto out;
 898                 }
 899                 vm_addr = &vsk->remote_addr;
 900         } else {
 901                 vm_addr = &vsk->local_addr;
 902         }
 903
 904         if (!vm_addr) {
 905                 err = -EINVAL;
 906                 goto out;
 907         }
 908
 909         /* sys_getsockname() and sys_getpeername() pass us a
 910          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
 911          * that macro is defined in socket.c instead of .h, so we hardcode its
 912          * value here.
 913          */
 914         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
 915         memcpy(addr, vm_addr, sizeof(*vm_addr));
 916         err = sizeof(*vm_addr);
 917
 918 out:
 919         release_sock(sk);
 920         return err;
 921 }
 922
 923 static int vsock_shutdown(struct socket *sock, int mode)
 924 {
 925         int err;
 926         struct sock *sk;
 927
 928         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
 929          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
 930          * here like the other address families do.  Note also that the
 931          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
 932          * which is what we want.
 933          */
 934         mode++;
 935
 936         if ((mode & ~SHUTDOWN_MASK) || !mode)
 937                 return -EINVAL;
 938
 939         /* If this is a STREAM socket and it is not connected then bail out
 940          * immediately.  If it is a DGRAM socket then we must first kick the
 941          * socket so that it wakes up from any sleeping calls, for example
 942          * recv(), and then afterwards return the error.
 943          */
 944
 945         sk = sock->sk;
 946         if (sock->state == SS_UNCONNECTED) {
 947                 err = -ENOTCONN;
 948                 if (sk->sk_type == SOCK_STREAM)
 949                         return err;
 950         } else {
 951                 sock->state = SS_DISCONNECTING;
 952                 err = 0;
 953         }
 954
 955         /* Receive and send shutdowns are treated alike. */
 956         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
 957         if (mode) {
 958                 lock_sock(sk);
 959                 sk->sk_shutdown |= mode;
 960                 sk->sk_state_change(sk);
 961                 release_sock(sk);
 962
 963                 if (sk->sk_type == SOCK_STREAM) {
 964                         sock_reset_flag(sk, SOCK_DONE);
 965                         vsock_send_shutdown(sk, mode);
 966                 }
 967         }
 968
 969         return err;
 970 }
 971
 972 static __poll_t vsock_poll(struct file *file, struct socket *sock,
 973                                poll_table *wait)
 974 {
 975         struct sock *sk;
 976         __poll_t mask;
 977         struct vsock_sock *vsk;
 978
 979         sk = sock->sk;
 980         vsk = vsock_sk(sk);
 981
 982         poll_wait(file, sk_sleep(sk), wait);
 983         mask = 0;
 984
 985         if (sk->sk_err)
 986                 /* Signify that there has been an error on this socket. */
 987                 mask |= EPOLLERR;
 988
 989         /* INET sockets treat local write shutdown and peer write shutdown as a
 990          * case of EPOLLHUP set.
 991          */
 992         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
 993             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
 994              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
 995                 mask |= EPOLLHUP;
 996         }
 997
 998         if (sk->sk_shutdown & RCV_SHUTDOWN ||
 999             vsk->peer_shutdown & SEND_SHUTDOWN) {
1000                 mask |= EPOLLRDHUP;
1001         }
1002
1003         if (sock->type == SOCK_DGRAM) {
1004                 /* For datagram sockets we can read if there is something in
1005                  * the queue and write as long as the socket isn't shutdown for
1006                  * sending.
1007                  */
1008                 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1009                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
1010                         mask |= EPOLLIN | EPOLLRDNORM;
1011                 }
1012
1013                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1014                         mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1015
1016         } else if (sock->type == SOCK_STREAM) {
1017                 const struct vsock_transport *transport;
1018
1019                 lock_sock(sk);
1020
1021                 transport = vsk->transport;
1022
1023                 /* Listening sockets that have connections in their accept
1024                  * queue can be read.
1025                  */
1026                 if (sk->sk_state == TCP_LISTEN
1027                     && !vsock_is_accept_queue_empty(sk))
1028                         mask |= EPOLLIN | EPOLLRDNORM;
1029
1030                 /* If there is something in the queue then we can read. */
1031                 if (transport && transport->stream_is_active(vsk) &&
1032                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1033                         bool data_ready_now = false;
1034                         int ret = transport->notify_poll_in(
1035                                         vsk, 1, &data_ready_now);
1036                         if (ret < 0) {
1037                                 mask |= EPOLLERR;
1038                         } else {
1039                                 if (data_ready_now)
1040                                         mask |= EPOLLIN | EPOLLRDNORM;
1041
1042                         }
1043                 }
1044
1045                 /* Sockets whose connections have been closed, reset, or
1046                  * terminated should also be considered read, and we check the
1047                  * shutdown flag for that.
1048                  */
1049                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
1050                     vsk->peer_shutdown & SEND_SHUTDOWN) {
1051                         mask |= EPOLLIN | EPOLLRDNORM;
1052                 }
1053
1054                 /* Connected sockets that can produce data can be written. */
1055                 if (transport && sk->sk_state == TCP_ESTABLISHED) {
1056                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1057                                 bool space_avail_now = false;
1058                                 int ret = transport->notify_poll_out(
1059                                                 vsk, 1, &space_avail_now);
1060                                 if (ret < 0) {
1061                                         mask |= EPOLLERR;
1062                                 } else {
1063                                         if (space_avail_now)
1064                                                 /* Remove EPOLLWRBAND since INET
1065                                                  * sockets are not setting it.
1066                                                  */
1067                                                 mask |= EPOLLOUT | EPOLLWRNORM;
1068
1069                                 }
1070                         }
1071                 }
1072
1073                 /* Simulate INET socket poll behaviors, which sets
1074                  * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1075                  * but local send is not shutdown.
1076                  */
1077                 if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1078                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1079                                 mask |= EPOLLOUT | EPOLLWRNORM;
1080
1081                 }
1082
1083                 release_sock(sk);
1084         }
1085
1086         return mask;
1087 }
1088
1089 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1090                                size_t len)
1091 {
1092         int err;
1093         struct sock *sk;
1094         struct vsock_sock *vsk;
1095         struct sockaddr_vm *remote_addr;
1096         const struct vsock_transport *transport;
1097
1098         if (msg->msg_flags & MSG_OOB)
1099                 return -EOPNOTSUPP;
1100
1101         /* For now, MSG_DONTWAIT is always assumed... */
1102         err = 0;
1103         sk = sock->sk;
1104         vsk = vsock_sk(sk);
1105
1106         lock_sock(sk);
1107
1108         transport = vsk->transport;
1109
1110         err = vsock_auto_bind(vsk);
1111         if (err)
1112                 goto out;
1113
1114
1115         /* If the provided message contains an address, use that.  Otherwise
1116          * fall back on the socket's remote handle (if it has been connected).
1117          */
1118         if (msg->msg_name &&
1119             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1120                             &remote_addr) == 0) {
1121                 /* Ensure this address is of the right type and is a valid
1122                  * destination.
1123                  */
1124
1125                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1126                         remote_addr->svm_cid = transport->get_local_cid();
1127
1128                 if (!vsock_addr_bound(remote_addr)) {
1129                         err = -EINVAL;
1130                         goto out;
1131                 }
1132         } else if (sock->state == SS_CONNECTED) {
1133                 remote_addr = &vsk->remote_addr;
1134
1135                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
1136                         remote_addr->svm_cid = transport->get_local_cid();
1137
1138                 /* XXX Should connect() or this function ensure remote_addr is
1139                  * bound?
1140                  */
1141                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1142                         err = -EINVAL;
1143                         goto out;
1144                 }
1145         } else {
1146                 err = -EINVAL;
1147                 goto out;
1148         }
1149
1150         if (!transport->dgram_allow(remote_addr->svm_cid,
1151                                     remote_addr->svm_port)) {
1152                 err = -EINVAL;
1153                 goto out;
1154         }
1155
1156         err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1157
1158 out:
1159         release_sock(sk);
1160         return err;
1161 }
1162
1163 static int vsock_dgram_connect(struct socket *sock,
1164                                struct sockaddr *addr, int addr_len, int flags)
1165 {
1166         int err;
1167         struct sock *sk;
1168         struct vsock_sock *vsk;
1169         struct sockaddr_vm *remote_addr;
1170
1171         sk = sock->sk;
1172         vsk = vsock_sk(sk);
1173
1174         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1175         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1176                 lock_sock(sk);
1177                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1178                                 VMADDR_PORT_ANY);
1179                 sock->state = SS_UNCONNECTED;
1180                 release_sock(sk);
1181                 return 0;
1182         } else if (err != 0)
1183                 return -EINVAL;
1184
1185         lock_sock(sk);
1186
1187         err = vsock_auto_bind(vsk);
1188         if (err)
1189                 goto out;
1190
1191         if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1192                                          remote_addr->svm_port)) {
1193                 err = -EINVAL;
1194                 goto out;
1195         }
1196
1197         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1198         sock->state = SS_CONNECTED;
1199
1200 out:
1201         release_sock(sk);
1202         return err;
1203 }
1204
1205 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1206                                size_t len, int flags)
1207 {
1208         struct vsock_sock *vsk = vsock_sk(sock->sk);
1209
1210         return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1211 }
1212
1213 static const struct proto_ops vsock_dgram_ops = {
1214         .family = PF_VSOCK,
1215         .owner = THIS_MODULE,
1216         .release = vsock_release,
1217         .bind = vsock_bind,
1218         .connect = vsock_dgram_connect,
1219         .socketpair = sock_no_socketpair,
1220         .accept = sock_no_accept,
1221         .getname = vsock_getname,
1222         .poll = vsock_poll,
1223         .ioctl = sock_no_ioctl,
1224         .listen = sock_no_listen,
1225         .shutdown = vsock_shutdown,
1226         .sendmsg = vsock_dgram_sendmsg,
1227         .recvmsg = vsock_dgram_recvmsg,
1228         .mmap = sock_no_mmap,
1229         .sendpage = sock_no_sendpage,
1230 };
1231
1232 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1233 {
1234         const struct vsock_transport *transport = vsk->transport;
1235
1236         if (!transport->cancel_pkt)
1237                 return -EOPNOTSUPP;
1238
1239         return transport->cancel_pkt(vsk);
1240 }
1241
1242 static void vsock_connect_timeout(struct work_struct *work)
1243 {
1244         struct sock *sk;
1245         struct vsock_sock *vsk;
1246         int cancel = 0;
1247
1248         vsk = container_of(work, struct vsock_sock, connect_work.work);
1249         sk = sk_vsock(vsk);
1250
1251         lock_sock(sk);
1252         if (sk->sk_state == TCP_SYN_SENT &&
1253             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1254                 sk->sk_state = TCP_CLOSE;
1255                 sk->sk_err = ETIMEDOUT;
1256                 sk->sk_error_report(sk);
1257                 cancel = 1;
1258         }
1259         release_sock(sk);
1260         if (cancel)
1261                 vsock_transport_cancel_pkt(vsk);
1262
1263         sock_put(sk);
1264 }
1265
1266 static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
1267                                 int addr_len, int flags)
1268 {
1269         int err;
1270         struct sock *sk;
1271         struct vsock_sock *vsk;
1272         const struct vsock_transport *transport;
1273         struct sockaddr_vm *remote_addr;
1274         long timeout;
1275         DEFINE_WAIT(wait);
1276
1277         err = 0;
1278         sk = sock->sk;
1279         vsk = vsock_sk(sk);
1280
1281         lock_sock(sk);
1282
1283         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1284         switch (sock->state) {
1285         case SS_CONNECTED:
1286                 err = -EISCONN;
1287                 goto out;
1288         case SS_DISCONNECTING:
1289                 err = -EINVAL;
1290                 goto out;
1291         case SS_CONNECTING:
1292                 /* This continues on so we can move sock into the SS_CONNECTED
1293                  * state once the connection has completed (at which point err
1294                  * will be set to zero also).  Otherwise, we will either wait
1295                  * for the connection or return -EALREADY should this be a
1296                  * non-blocking call.
1297                  */
1298                 err = -EALREADY;
1299                 break;
1300         default:
1301                 if ((sk->sk_state == TCP_LISTEN) ||
1302                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1303                         err = -EINVAL;
1304                         goto out;
1305                 }
1306
1307                 /* Set the remote address that we are connecting to. */
1308                 memcpy(&vsk->remote_addr, remote_addr,
1309                        sizeof(vsk->remote_addr));
1310
1311                 err = vsock_assign_transport(vsk, NULL);
1312                 if (err)
1313                         goto out;
1314
1315                 transport = vsk->transport;
1316
1317                 /* The hypervisor and well-known contexts do not have socket
1318                  * endpoints.
1319                  */
1320                 if (!transport ||
1321                     !transport->stream_allow(remote_addr->svm_cid,
1322                                              remote_addr->svm_port)) {
1323                         err = -ENETUNREACH;
1324                         goto out;
1325                 }
1326
1327                 err = vsock_auto_bind(vsk);
1328                 if (err)
1329                         goto out;
1330
1331                 sk->sk_state = TCP_SYN_SENT;
1332
1333                 err = transport->connect(vsk);
1334                 if (err < 0)
1335                         goto out;
1336
1337                 /* Mark sock as connecting and set the error code to in
1338                  * progress in case this is a non-blocking connect.
1339                  */
1340                 sock->state = SS_CONNECTING;
1341                 err = -EINPROGRESS;
1342         }
1343
1344         /* The receive path will handle all communication until we are able to
1345          * enter the connected state.  Here we wait for the connection to be
1346          * completed or a notification of an error.
1347          */
1348         timeout = vsk->connect_timeout;
1349         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1350
1351         while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1352                 if (flags & O_NONBLOCK) {
1353                         /* If we're not going to block, we schedule a timeout
1354                          * function to generate a timeout on the connection
1355                          * attempt, in case the peer doesn't respond in a
1356                          * timely manner. We hold on to the socket until the
1357                          * timeout fires.
1358                          */
1359                         sock_hold(sk);
1360                         schedule_delayed_work(&vsk->connect_work, timeout);
1361
1362                         /* Skip ahead to preserve error code set above. */
1363                         goto out_wait;
1364                 }
1365
1366                 release_sock(sk);
1367                 timeout = schedule_timeout(timeout);
1368                 lock_sock(sk);
1369
1370                 if (signal_pending(current)) {
1371                         err = sock_intr_errno(timeout);
1372                         sk->sk_state = TCP_CLOSE;
1373                         sock->state = SS_UNCONNECTED;
1374                         vsock_transport_cancel_pkt(vsk);
1375                         goto out_wait;
1376                 } else if (timeout == 0) {
1377                         err = -ETIMEDOUT;
1378                         sk->sk_state = TCP_CLOSE;
1379                         sock->state = SS_UNCONNECTED;
1380                         vsock_transport_cancel_pkt(vsk);
1381                         goto out_wait;
1382                 }
1383
1384                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1385         }
1386
1387         if (sk->sk_err) {
1388                 err = -sk->sk_err;
1389                 sk->sk_state = TCP_CLOSE;
1390                 sock->state = SS_UNCONNECTED;
1391         } else {
1392                 err = 0;
1393         }
1394
1395 out_wait:
1396         finish_wait(sk_sleep(sk), &wait);
1397 out:
1398         release_sock(sk);
1399         return err;
1400 }
1401
1402 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1403                         bool kern)
1404 {
1405         struct sock *listener;
1406         int err;
1407         struct sock *connected;
1408         struct vsock_sock *vconnected;
1409         long timeout;
1410         DEFINE_WAIT(wait);
1411
1412         err = 0;
1413         listener = sock->sk;
1414
1415         lock_sock(listener);
1416
1417         if (sock->type != SOCK_STREAM) {
1418                 err = -EOPNOTSUPP;
1419                 goto out;
1420         }
1421
1422         if (listener->sk_state != TCP_LISTEN) {
1423                 err = -EINVAL;
1424                 goto out;
1425         }
1426
1427         /* Wait for children sockets to appear; these are the new sockets
1428          * created upon connection establishment.
1429          */
1430         timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1431         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1432
1433         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1434                listener->sk_err == 0) {
1435                 release_sock(listener);
1436                 timeout = schedule_timeout(timeout);
1437                 finish_wait(sk_sleep(listener), &wait);
1438                 lock_sock(listener);
1439
1440                 if (signal_pending(current)) {
1441                         err = sock_intr_errno(timeout);
1442                         goto out;
1443                 } else if (timeout == 0) {
1444                         err = -EAGAIN;
1445                         goto out;
1446                 }
1447
1448                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1449         }
1450         finish_wait(sk_sleep(listener), &wait);
1451
1452         if (listener->sk_err)
1453                 err = -listener->sk_err;
1454
1455         if (connected) {
1456                 sk_acceptq_removed(listener);
1457
1458                 lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1459                 vconnected = vsock_sk(connected);
1460
1461                 /* If the listener socket has received an error, then we should
1462                  * reject this socket and return.  Note that we simply mark the
1463                  * socket rejected, drop our reference, and let the cleanup
1464                  * function handle the cleanup; the fact that we found it in
1465                  * the listener's accept queue guarantees that the cleanup
1466                  * function hasn't run yet.
1467                  */
1468                 if (err) {
1469                         vconnected->rejected = true;
1470                 } else {
1471                         newsock->state = SS_CONNECTED;
1472                         sock_graft(connected, newsock);
1473                 }
1474
1475                 release_sock(connected);
1476                 sock_put(connected);
1477         }
1478
1479 out:
1480         release_sock(listener);
1481         return err;
1482 }
1483
1484 static int vsock_listen(struct socket *sock, int backlog)
1485 {
1486         int err;
1487         struct sock *sk;
1488         struct vsock_sock *vsk;
1489
1490         sk = sock->sk;
1491
1492         lock_sock(sk);
1493
1494         if (sock->type != SOCK_STREAM) {
1495                 err = -EOPNOTSUPP;
1496                 goto out;
1497         }
1498
1499         if (sock->state != SS_UNCONNECTED) {
1500                 err = -EINVAL;
1501                 goto out;
1502         }
1503
1504         vsk = vsock_sk(sk);
1505
1506         if (!vsock_addr_bound(&vsk->local_addr)) {
1507                 err = -EINVAL;
1508                 goto out;
1509         }
1510
1511         sk->sk_max_ack_backlog = backlog;
1512         sk->sk_state = TCP_LISTEN;
1513
1514         err = 0;
1515
1516 out:
1517         release_sock(sk);
1518         return err;
1519 }
1520
1521 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1522                                      const struct vsock_transport *transport,
1523                                      u64 val)
1524 {
1525         if (val > vsk->buffer_max_size)
1526                 val = vsk->buffer_max_size;
1527
1528         if (val < vsk->buffer_min_size)
1529                 val = vsk->buffer_min_size;
1530
1531         if (val != vsk->buffer_size &&
1532             transport && transport->notify_buffer_size)
1533                 transport->notify_buffer_size(vsk, &val);
1534
1535         vsk->buffer_size = val;
1536 }
1537
1538 static int vsock_stream_setsockopt(struct socket *sock,
1539                                    int level,
1540                                    int optname,
1541                                    sockptr_t optval,
1542                                    unsigned int optlen)
1543 {
1544         int err;
1545         struct sock *sk;
1546         struct vsock_sock *vsk;
1547         const struct vsock_transport *transport;
1548         u64 val;
1549
1550         if (level != AF_VSOCK)
1551                 return -ENOPROTOOPT;
1552
1553 #define COPY_IN(_v)                                       \
1554         do {                                              \
1555                 if (optlen < sizeof(_v)) {                \
1556                         err = -EINVAL;                    \
1557                         goto exit;                        \
1558                 }                                         \
1559                 if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {  \
1560                         err = -EFAULT;                                  \
1561                         goto exit;                                      \
1562                 }                                                       \
1563         } while (0)
1564
1565         err = 0;
1566         sk = sock->sk;
1567         vsk = vsock_sk(sk);
1568
1569         lock_sock(sk);
1570
1571         transport = vsk->transport;
1572
1573         switch (optname) {
1574         case SO_VM_SOCKETS_BUFFER_SIZE:
1575                 COPY_IN(val);
1576                 vsock_update_buffer_size(vsk, transport, val);
1577                 break;
1578
1579         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1580                 COPY_IN(val);
1581                 vsk->buffer_max_size = val;
1582                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1583                 break;
1584
1585         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1586                 COPY_IN(val);
1587                 vsk->buffer_min_size = val;
1588                 vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1589                 break;
1590
1591         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1592                 struct __kernel_old_timeval tv;
1593                 COPY_IN(tv);
1594                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1595                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1596                         vsk->connect_timeout = tv.tv_sec * HZ +
1597                             DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1598                         if (vsk->connect_timeout == 0)
1599                                 vsk->connect_timeout =
1600                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1601
1602                 } else {
1603                         err = -ERANGE;
1604                 }
1605                 break;
1606         }
1607
1608         default:
1609                 err = -ENOPROTOOPT;
1610                 break;
1611         }
1612
1613 #undef COPY_IN
1614
1615 exit:
1616         release_sock(sk);
1617         return err;
1618 }
1619
1620 static int vsock_stream_getsockopt(struct socket *sock,
1621                                    int level, int optname,
1622                                    char __user *optval,
1623                                    int __user *optlen)
1624 {
1625         int err;
1626         int len;
1627         struct sock *sk;
1628         struct vsock_sock *vsk;
1629         u64 val;
1630
1631         if (level != AF_VSOCK)
1632                 return -ENOPROTOOPT;
1633
1634         err = get_user(len, optlen);
1635         if (err != 0)
1636                 return err;
1637
1638 #define COPY_OUT(_v)                            \
1639         do {                                    \
1640                 if (len < sizeof(_v))           \
1641                         return -EINVAL;         \
1642                                                 \
1643                 len = sizeof(_v);               \
1644                 if (copy_to_user(optval, &_v, len) != 0)        \
1645                         return -EFAULT;                         \
1646                                                                 \
1647         } while (0)
1648
1649         err = 0;
1650         sk = sock->sk;
1651         vsk = vsock_sk(sk);
1652
1653         switch (optname) {
1654         case SO_VM_SOCKETS_BUFFER_SIZE:
1655                 val = vsk->buffer_size;
1656                 COPY_OUT(val);
1657                 break;
1658
1659         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1660                 val = vsk->buffer_max_size;
1661                 COPY_OUT(val);
1662                 break;
1663
1664         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1665                 val = vsk->buffer_min_size;
1666                 COPY_OUT(val);
1667                 break;
1668
1669         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1670                 struct __kernel_old_timeval tv;
1671                 tv.tv_sec = vsk->connect_timeout / HZ;
1672                 tv.tv_usec =
1673                     (vsk->connect_timeout -
1674                      tv.tv_sec * HZ) * (1000000 / HZ);
1675                 COPY_OUT(tv);
1676                 break;
1677         }
1678         default:
1679                 return -ENOPROTOOPT;
1680         }
1681
1682         err = put_user(len, optlen);
1683         if (err != 0)
1684                 return -EFAULT;
1685
1686 #undef COPY_OUT
1687
1688         return 0;
1689 }
1690
1691 static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1692                                 size_t len)
1693 {
1694         struct sock *sk;
1695         struct vsock_sock *vsk;
1696         const struct vsock_transport *transport;
1697         ssize_t total_written;
1698         long timeout;
1699         int err;
1700         struct vsock_transport_send_notify_data send_data;
1701         DEFINE_WAIT_FUNC(wait, woken_wake_function);
1702
1703         sk = sock->sk;
1704         vsk = vsock_sk(sk);
1705         total_written = 0;
1706         err = 0;
1707
1708         if (msg->msg_flags & MSG_OOB)
1709                 return -EOPNOTSUPP;
1710
1711         lock_sock(sk);
1712
1713         transport = vsk->transport;
1714
1715         /* Callers should not provide a destination with stream sockets. */
1716         if (msg->msg_namelen) {
1717                 err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1718                 goto out;
1719         }
1720
1721         /* Send data only if both sides are not shutdown in the direction. */
1722         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1723             vsk->peer_shutdown & RCV_SHUTDOWN) {
1724                 err = -EPIPE;
1725                 goto out;
1726         }
1727
1728         if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1729             !vsock_addr_bound(&vsk->local_addr)) {
1730                 err = -ENOTCONN;
1731                 goto out;
1732         }
1733
1734         if (!vsock_addr_bound(&vsk->remote_addr)) {
1735                 err = -EDESTADDRREQ;
1736                 goto out;
1737         }
1738
1739         /* Wait for room in the produce queue to enqueue our user's data. */
1740         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1741
1742         err = transport->notify_send_init(vsk, &send_data);
1743         if (err < 0)
1744                 goto out;
1745
1746         while (total_written < len) {
1747                 ssize_t written;
1748
1749                 add_wait_queue(sk_sleep(sk), &wait);
1750                 while (vsock_stream_has_space(vsk) == 0 &&
1751                        sk->sk_err == 0 &&
1752                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1753                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1754
1755                         /* Don't wait for non-blocking sockets. */
1756                         if (timeout == 0) {
1757                                 err = -EAGAIN;
1758                                 remove_wait_queue(sk_sleep(sk), &wait);
1759                                 goto out_err;
1760                         }
1761
1762                         err = transport->notify_send_pre_block(vsk, &send_data);
1763                         if (err < 0) {
1764                                 remove_wait_queue(sk_sleep(sk), &wait);
1765                                 goto out_err;
1766                         }
1767
1768                         release_sock(sk);
1769                         timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1770                         lock_sock(sk);
1771                         if (signal_pending(current)) {
1772                                 err = sock_intr_errno(timeout);
1773                                 remove_wait_queue(sk_sleep(sk), &wait);
1774                                 goto out_err;
1775                         } else if (timeout == 0) {
1776                                 err = -EAGAIN;
1777                                 remove_wait_queue(sk_sleep(sk), &wait);
1778                                 goto out_err;
1779                         }
1780                 }
1781                 remove_wait_queue(sk_sleep(sk), &wait);
1782
1783                 /* These checks occur both as part of and after the loop
1784                  * conditional since we need to check before and after
1785                  * sleeping.
1786                  */
1787                 if (sk->sk_err) {
1788                         err = -sk->sk_err;
1789                         goto out_err;
1790                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1791                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1792                         err = -EPIPE;
1793                         goto out_err;
1794                 }
1795
1796                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1797                 if (err < 0)
1798                         goto out_err;
1799
1800                 /* Note that enqueue will only write as many bytes as are free
1801                  * in the produce queue, so we don't need to ensure len is
1802                  * smaller than the queue size.  It is the caller's
1803                  * responsibility to check how many bytes we were able to send.
1804                  */
1805
1806                 written = transport->stream_enqueue(
1807                                 vsk, msg,
1808                                 len - total_written);
1809                 if (written < 0) {
1810                         err = -ENOMEM;
1811                         goto out_err;
1812                 }
1813
1814                 total_written += written;
1815
1816                 err = transport->notify_send_post_enqueue(
1817                                 vsk, written, &send_data);
1818                 if (err < 0)
1819                         goto out_err;
1820
1821         }
1822
1823 out_err:
1824         if (total_written > 0)
1825                 err = total_written;
1826 out:
1827         release_sock(sk);
1828         return err;
1829 }
1830
1831
1832 static int
1833 vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1834                      int flags)
1835 {
1836         struct sock *sk;
1837         struct vsock_sock *vsk;
1838         const struct vsock_transport *transport;
1839         int err;
1840         size_t target;
1841         ssize_t copied;
1842         long timeout;
1843         struct vsock_transport_recv_notify_data recv_data;
1844
1845         DEFINE_WAIT(wait);
1846
1847         sk = sock->sk;
1848         vsk = vsock_sk(sk);
1849         err = 0;
1850
1851         lock_sock(sk);
1852
1853         transport = vsk->transport;
1854
1855         if (!transport || sk->sk_state != TCP_ESTABLISHED) {
1856                 /* Recvmsg is supposed to return 0 if a peer performs an
1857                  * orderly shutdown. Differentiate between that case and when a
1858                  * peer has not connected or a local shutdown occured with the
1859                  * SOCK_DONE flag.
1860                  */
1861                 if (sock_flag(sk, SOCK_DONE))
1862                         err = 0;
1863                 else
1864                         err = -ENOTCONN;
1865
1866                 goto out;
1867         }
1868
1869         if (flags & MSG_OOB) {
1870                 err = -EOPNOTSUPP;
1871                 goto out;
1872         }
1873
1874         /* We don't check peer_shutdown flag here since peer may actually shut
1875          * down, but there can be data in the queue that a local socket can
1876          * receive.
1877          */
1878         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1879                 err = 0;
1880                 goto out;
1881         }
1882
1883         /* It is valid on Linux to pass in a zero-length receive buffer.  This
1884          * is not an error.  We may as well bail out now.
1885          */
1886         if (!len) {
1887                 err = 0;
1888                 goto out;
1889         }
1890
1891         /* We must not copy less than target bytes into the user's buffer
1892          * before returning successfully, so we wait for the consume queue to
1893          * have that much data to consume before dequeueing.  Note that this
1894          * makes it impossible to handle cases where target is greater than the
1895          * queue size.
1896          */
1897         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1898         if (target >= transport->stream_rcvhiwat(vsk)) {
1899                 err = -ENOMEM;
1900                 goto out;
1901         }
1902         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1903         copied = 0;
1904
1905         err = transport->notify_recv_init(vsk, target, &recv_data);
1906         if (err < 0)
1907                 goto out;
1908
1909
1910         while (1) {
1911                 s64 ready;
1912
1913                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1914                 ready = vsock_stream_has_data(vsk);
1915
1916                 if (ready == 0) {
1917                         if (sk->sk_err != 0 ||
1918                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
1919                             (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1920                                 finish_wait(sk_sleep(sk), &wait);
1921                                 break;
1922                         }
1923                         /* Don't wait for non-blocking sockets. */
1924                         if (timeout == 0) {
1925                                 err = -EAGAIN;
1926                                 finish_wait(sk_sleep(sk), &wait);
1927                                 break;
1928                         }
1929
1930                         err = transport->notify_recv_pre_block(
1931                                         vsk, target, &recv_data);
1932                         if (err < 0) {
1933                                 finish_wait(sk_sleep(sk), &wait);
1934                                 break;
1935                         }
1936                         release_sock(sk);
1937                         timeout = schedule_timeout(timeout);
1938                         lock_sock(sk);
1939
1940                         if (signal_pending(current)) {
1941                                 err = sock_intr_errno(timeout);
1942                                 finish_wait(sk_sleep(sk), &wait);
1943                                 break;
1944                         } else if (timeout == 0) {
1945                                 err = -EAGAIN;
1946                                 finish_wait(sk_sleep(sk), &wait);
1947                                 break;
1948                         }
1949                 } else {
1950                         ssize_t read;
1951
1952                         finish_wait(sk_sleep(sk), &wait);
1953
1954                         if (ready < 0) {
1955                                 /* Invalid queue pair content. XXX This should
1956                                 * be changed to a connection reset in a later
1957                                 * change.
1958                                 */
1959
1960                                 err = -ENOMEM;
1961                                 goto out;
1962                         }
1963
1964                         err = transport->notify_recv_pre_dequeue(
1965                                         vsk, target, &recv_data);
1966                         if (err < 0)
1967                                 break;
1968
1969                         read = transport->stream_dequeue(
1970                                         vsk, msg,
1971                                         len - copied, flags);
1972                         if (read < 0) {
1973                                 err = -ENOMEM;
1974                                 break;
1975                         }
1976
1977                         copied += read;
1978
1979                         err = transport->notify_recv_post_dequeue(
1980                                         vsk, target, read,
1981                                         !(flags & MSG_PEEK), &recv_data);
1982                         if (err < 0)
1983                                 goto out;
1984
1985                         if (read >= target || flags & MSG_PEEK)
1986                                 break;
1987
1988                         target -= read;
1989                 }
1990         }
1991
1992         if (sk->sk_err)
1993                 err = -sk->sk_err;
1994         else if (sk->sk_shutdown & RCV_SHUTDOWN)
1995                 err = 0;
1996
1997         if (copied > 0)
1998                 err = copied;
1999
2000 out:
2001         release_sock(sk);
2002         return err;
2003 }
2004
2005 static const struct proto_ops vsock_stream_ops = {
2006         .family = PF_VSOCK,
2007         .owner = THIS_MODULE,
2008         .release = vsock_release,
2009         .bind = vsock_bind,
2010         .connect = vsock_stream_connect,
2011         .socketpair = sock_no_socketpair,
2012         .accept = vsock_accept,
2013         .getname = vsock_getname,
2014         .poll = vsock_poll,
2015         .ioctl = sock_no_ioctl,
2016         .listen = vsock_listen,
2017         .shutdown = vsock_shutdown,
2018         .setsockopt = vsock_stream_setsockopt,
2019         .getsockopt = vsock_stream_getsockopt,
2020         .sendmsg = vsock_stream_sendmsg,
2021         .recvmsg = vsock_stream_recvmsg,
2022         .mmap = sock_no_mmap,
2023         .sendpage = sock_no_sendpage,
2024 };
2025
2026 static int vsock_create(struct net *net, struct socket *sock,
2027                         int protocol, int kern)
2028 {
2029         struct vsock_sock *vsk;
2030         struct sock *sk;
2031         int ret;
2032
2033         if (!sock)
2034                 return -EINVAL;
2035
2036         if (protocol && protocol != PF_VSOCK)
2037                 return -EPROTONOSUPPORT;
2038
2039         switch (sock->type) {
2040         case SOCK_DGRAM:
2041                 sock->ops = &vsock_dgram_ops;
2042                 break;
2043         case SOCK_STREAM:
2044                 sock->ops = &vsock_stream_ops;
2045                 break;
2046         default:
2047                 return -ESOCKTNOSUPPORT;
2048         }
2049
2050         sock->state = SS_UNCONNECTED;
2051
2052         sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2053         if (!sk)
2054                 return -ENOMEM;
2055
2056         vsk = vsock_sk(sk);
2057
2058         if (sock->type == SOCK_DGRAM) {
2059                 ret = vsock_assign_transport(vsk, NULL);
2060                 if (ret < 0) {
2061                         sock_put(sk);
2062                         return ret;
2063                 }
2064         }
2065
2066         vsock_insert_unbound(vsk);
2067
2068         return 0;
2069 }
2070
2071 static const struct net_proto_family vsock_family_ops = {
2072         .family = AF_VSOCK,
2073         .create = vsock_create,
2074         .owner = THIS_MODULE,
2075 };
2076
2077 static long vsock_dev_do_ioctl(struct file *filp,
2078                                unsigned int cmd, void __user *ptr)
2079 {
2080         u32 __user *p = ptr;
2081         u32 cid = VMADDR_CID_ANY;
2082         int retval = 0;
2083
2084         switch (cmd) {
2085         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2086                 /* To be compatible with the VMCI behavior, we prioritize the
2087                  * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2088                  */
2089                 if (transport_g2h)
2090                         cid = transport_g2h->get_local_cid();
2091                 else if (transport_h2g)
2092                         cid = transport_h2g->get_local_cid();
2093
2094                 if (put_user(cid, p) != 0)
2095                         retval = -EFAULT;
2096                 break;
2097
2098         default:
2099                 retval = -ENOIOCTLCMD;
2100         }
2101
2102         return retval;
2103 }
2104
2105 static long vsock_dev_ioctl(struct file *filp,
2106                             unsigned int cmd, unsigned long arg)
2107 {
2108         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2109 }
2110
2111 #ifdef CONFIG_COMPAT
2112 static long vsock_dev_compat_ioctl(struct file *filp,
2113                                    unsigned int cmd, unsigned long arg)
2114 {
2115         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2116 }
2117 #endif
2118
2119 static const struct file_operations vsock_device_ops = {
2120         .owner          = THIS_MODULE,
2121         .unlocked_ioctl = vsock_dev_ioctl,
2122 #ifdef CONFIG_COMPAT
2123         .compat_ioctl   = vsock_dev_compat_ioctl,
2124 #endif
2125         .open           = nonseekable_open,
2126 };
2127
2128 static struct miscdevice vsock_device = {
2129         .name           = "vsock",
2130         .fops           = &vsock_device_ops,
2131 };
2132
2133 static int __init vsock_init(void)
2134 {
2135         int err = 0;
2136
2137         vsock_init_tables();
2138
2139         vsock_proto.owner = THIS_MODULE;
2140         vsock_device.minor = MISC_DYNAMIC_MINOR;
2141         err = misc_register(&vsock_device);
2142         if (err) {
2143                 pr_err("Failed to register misc device\n");
2144                 goto err_reset_transport;
2145         }
2146
2147         err = proto_register(&vsock_proto, 1);  /* we want our slab */
2148         if (err) {
2149                 pr_err("Cannot register vsock protocol\n");
2150                 goto err_deregister_misc;
2151         }
2152
2153         err = sock_register(&vsock_family_ops);
2154         if (err) {
2155                 pr_err("could not register af_vsock (%d) address family: %d\n",
2156                        AF_VSOCK, err);
2157                 goto err_unregister_proto;
2158         }
2159
2160         return 0;
2161
2162 err_unregister_proto:
2163         proto_unregister(&vsock_proto);
2164 err_deregister_misc:
2165         misc_deregister(&vsock_device);
2166 err_reset_transport:
2167         return err;
2168 }
2169
2170 static void __exit vsock_exit(void)
2171 {
2172         misc_deregister(&vsock_device);
2173         sock_unregister(AF_VSOCK);
2174         proto_unregister(&vsock_proto);
2175 }
2176
2177 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2178 {
2179         return vsk->transport;
2180 }
2181 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2182
2183 int vsock_core_register(const struct vsock_transport *t, int features)
2184 {
2185         const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2186         int err = mutex_lock_interruptible(&vsock_register_mutex);
2187
2188         if (err)
2189                 return err;
2190
2191         t_h2g = transport_h2g;
2192         t_g2h = transport_g2h;
2193         t_dgram = transport_dgram;
2194         t_local = transport_local;
2195
2196         if (features & VSOCK_TRANSPORT_F_H2G) {
2197                 if (t_h2g) {
2198                         err = -EBUSY;
2199                         goto err_busy;
2200                 }
2201                 t_h2g = t;
2202         }
2203
2204         if (features & VSOCK_TRANSPORT_F_G2H) {
2205                 if (t_g2h) {
2206                         err = -EBUSY;
2207                         goto err_busy;
2208                 }
2209                 t_g2h = t;
2210         }
2211
2212         if (features & VSOCK_TRANSPORT_F_DGRAM) {
2213                 if (t_dgram) {
2214                         err = -EBUSY;
2215                         goto err_busy;
2216                 }
2217                 t_dgram = t;
2218         }
2219
2220         if (features & VSOCK_TRANSPORT_F_LOCAL) {
2221                 if (t_local) {
2222                         err = -EBUSY;
2223                         goto err_busy;
2224                 }
2225                 t_local = t;
2226         }
2227
2228         transport_h2g = t_h2g;
2229         transport_g2h = t_g2h;
2230         transport_dgram = t_dgram;
2231         transport_local = t_local;
2232
2233 err_busy:
2234         mutex_unlock(&vsock_register_mutex);
2235         return err;
2236 }
2237 EXPORT_SYMBOL_GPL(vsock_core_register);
2238
2239 void vsock_core_unregister(const struct vsock_transport *t)
2240 {
2241         mutex_lock(&vsock_register_mutex);
2242
2243         if (transport_h2g == t)
2244                 transport_h2g = NULL;
2245
2246         if (transport_g2h == t)
2247                 transport_g2h = NULL;
2248
2249         if (transport_dgram == t)
2250                 transport_dgram = NULL;
2251
2252         if (transport_local == t)
2253                 transport_local = NULL;
2254
2255         mutex_unlock(&vsock_register_mutex);
2256 }
2257 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2258
2259 module_init(vsock_init);
2260 module_exit(vsock_exit);
2261
2262 MODULE_AUTHOR("VMware, Inc.");
2263 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2264 MODULE_VERSION("1.0.2.0-k");
2265 MODULE_LICENSE("GPL v2");