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TOMOYO Linux Cross Reference
Linux/net/vmw_vsock/af_vsock.c

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  1 /*
  2  * VMware vSockets Driver
  3  *
  4  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License as published by the Free
  8  * Software Foundation version 2 and no later version.
  9  *
 10  * This program is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 13  * more details.
 14  */
 15 
 16 /* Implementation notes:
 17  *
 18  * - There are two kinds of sockets: those created by user action (such as
 19  * calling socket(2)) and those created by incoming connection request packets.
 20  *
 21  * - There are two "global" tables, one for bound sockets (sockets that have
 22  * specified an address that they are responsible for) and one for connected
 23  * sockets (sockets that have established a connection with another socket).
 24  * These tables are "global" in that all sockets on the system are placed
 25  * within them. - Note, though, that the bound table contains an extra entry
 26  * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
 27  * that list. The bound table is used solely for lookup of sockets when packets
 28  * are received and that's not necessary for SOCK_DGRAM sockets since we create
 29  * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
 30  * sockets out of the bound hash buckets will reduce the chance of collisions
 31  * when looking for SOCK_STREAM sockets and prevents us from having to check the
 32  * socket type in the hash table lookups.
 33  *
 34  * - Sockets created by user action will either be "client" sockets that
 35  * initiate a connection or "server" sockets that listen for connections; we do
 36  * not support simultaneous connects (two "client" sockets connecting).
 37  *
 38  * - "Server" sockets are referred to as listener sockets throughout this
 39  * implementation because they are in the SS_LISTEN state.  When a connection
 40  * request is received (the second kind of socket mentioned above), we create a
 41  * new socket and refer to it as a pending socket.  These pending sockets are
 42  * placed on the pending connection list of the listener socket.  When future
 43  * packets are received for the address the listener socket is bound to, we
 44  * check if the source of the packet is from one that has an existing pending
 45  * connection.  If it does, we process the packet for the pending socket.  When
 46  * that socket reaches the connected state, it is removed from the listener
 47  * socket's pending list and enqueued in the listener socket's accept queue.
 48  * Callers of accept(2) will accept connected sockets from the listener socket's
 49  * accept queue.  If the socket cannot be accepted for some reason then it is
 50  * marked rejected.  Once the connection is accepted, it is owned by the user
 51  * process and the responsibility for cleanup falls with that user process.
 52  *
 53  * - It is possible that these pending sockets will never reach the connected
 54  * state; in fact, we may never receive another packet after the connection
 55  * request.  Because of this, we must schedule a cleanup function to run in the
 56  * future, after some amount of time passes where a connection should have been
 57  * established.  This function ensures that the socket is off all lists so it
 58  * cannot be retrieved, then drops all references to the socket so it is cleaned
 59  * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
 60  * function will also cleanup rejected sockets, those that reach the connected
 61  * state but leave it before they have been accepted.
 62  *
 63  * - Sockets created by user action will be cleaned up when the user process
 64  * calls close(2), causing our release implementation to be called. Our release
 65  * implementation will perform some cleanup then drop the last reference so our
 66  * sk_destruct implementation is invoked.  Our sk_destruct implementation will
 67  * perform additional cleanup that's common for both types of sockets.
 68  *
 69  * - A socket's reference count is what ensures that the structure won't be
 70  * freed.  Each entry in a list (such as the "global" bound and connected tables
 71  * and the listener socket's pending list and connected queue) ensures a
 72  * reference.  When we defer work until process context and pass a socket as our
 73  * argument, we must ensure the reference count is increased to ensure the
 74  * socket isn't freed before the function is run; the deferred function will
 75  * then drop the reference.
 76  */
 77 
 78 #include <linux/types.h>
 79 #include <linux/bitops.h>
 80 #include <linux/cred.h>
 81 #include <linux/init.h>
 82 #include <linux/io.h>
 83 #include <linux/kernel.h>
 84 #include <linux/kmod.h>
 85 #include <linux/list.h>
 86 #include <linux/miscdevice.h>
 87 #include <linux/module.h>
 88 #include <linux/mutex.h>
 89 #include <linux/net.h>
 90 #include <linux/poll.h>
 91 #include <linux/skbuff.h>
 92 #include <linux/smp.h>
 93 #include <linux/socket.h>
 94 #include <linux/stddef.h>
 95 #include <linux/unistd.h>
 96 #include <linux/wait.h>
 97 #include <linux/workqueue.h>
 98 #include <net/sock.h>
 99 #include <net/af_vsock.h>
100 
101 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
102 static void vsock_sk_destruct(struct sock *sk);
103 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
104 
105 /* Protocol family. */
106 static struct proto vsock_proto = {
107         .name = "AF_VSOCK",
108         .owner = THIS_MODULE,
109         .obj_size = sizeof(struct vsock_sock),
110 };
111 
112 /* The default peer timeout indicates how long we will wait for a peer response
113  * to a control message.
114  */
115 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
116 
117 #define SS_LISTEN 255
118 
119 static const struct vsock_transport *transport;
120 static DEFINE_MUTEX(vsock_register_mutex);
121 
122 /**** EXPORTS ****/
123 
124 /* Get the ID of the local context.  This is transport dependent. */
125 
126 int vm_sockets_get_local_cid(void)
127 {
128         return transport->get_local_cid();
129 }
130 EXPORT_SYMBOL_GPL(vm_sockets_get_local_cid);
131 
132 /**** UTILS ****/
133 
134 /* Each bound VSocket is stored in the bind hash table and each connected
135  * VSocket is stored in the connected hash table.
136  *
137  * Unbound sockets are all put on the same list attached to the end of the hash
138  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
139  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
140  * represents the list that addr hashes to).
141  *
142  * Specifically, we initialize the vsock_bind_table array to a size of
143  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
144  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
145  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
146  * mods with VSOCK_HASH_SIZE to ensure this.
147  */
148 #define VSOCK_HASH_SIZE         251
149 #define MAX_PORT_RETRIES        24
150 
151 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
152 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
153 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
154 
155 /* XXX This can probably be implemented in a better way. */
156 #define VSOCK_CONN_HASH(src, dst)                               \
157         (((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
158 #define vsock_connected_sockets(src, dst)               \
159         (&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
160 #define vsock_connected_sockets_vsk(vsk)                                \
161         vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
162 
163 static struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
164 static struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
165 static DEFINE_SPINLOCK(vsock_table_lock);
166 
167 /* Autobind this socket to the local address if necessary. */
168 static int vsock_auto_bind(struct vsock_sock *vsk)
169 {
170         struct sock *sk = sk_vsock(vsk);
171         struct sockaddr_vm local_addr;
172 
173         if (vsock_addr_bound(&vsk->local_addr))
174                 return 0;
175         vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
176         return __vsock_bind(sk, &local_addr);
177 }
178 
179 static void vsock_init_tables(void)
180 {
181         int i;
182 
183         for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
184                 INIT_LIST_HEAD(&vsock_bind_table[i]);
185 
186         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
187                 INIT_LIST_HEAD(&vsock_connected_table[i]);
188 }
189 
190 static void __vsock_insert_bound(struct list_head *list,
191                                  struct vsock_sock *vsk)
192 {
193         sock_hold(&vsk->sk);
194         list_add(&vsk->bound_table, list);
195 }
196 
197 static void __vsock_insert_connected(struct list_head *list,
198                                      struct vsock_sock *vsk)
199 {
200         sock_hold(&vsk->sk);
201         list_add(&vsk->connected_table, list);
202 }
203 
204 static void __vsock_remove_bound(struct vsock_sock *vsk)
205 {
206         list_del_init(&vsk->bound_table);
207         sock_put(&vsk->sk);
208 }
209 
210 static void __vsock_remove_connected(struct vsock_sock *vsk)
211 {
212         list_del_init(&vsk->connected_table);
213         sock_put(&vsk->sk);
214 }
215 
216 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
217 {
218         struct vsock_sock *vsk;
219 
220         list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table)
221                 if (addr->svm_port == vsk->local_addr.svm_port)
222                         return sk_vsock(vsk);
223 
224         return NULL;
225 }
226 
227 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
228                                                   struct sockaddr_vm *dst)
229 {
230         struct vsock_sock *vsk;
231 
232         list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
233                             connected_table) {
234                 if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
235                     dst->svm_port == vsk->local_addr.svm_port) {
236                         return sk_vsock(vsk);
237                 }
238         }
239 
240         return NULL;
241 }
242 
243 static bool __vsock_in_bound_table(struct vsock_sock *vsk)
244 {
245         return !list_empty(&vsk->bound_table);
246 }
247 
248 static bool __vsock_in_connected_table(struct vsock_sock *vsk)
249 {
250         return !list_empty(&vsk->connected_table);
251 }
252 
253 static void vsock_insert_unbound(struct vsock_sock *vsk)
254 {
255         spin_lock_bh(&vsock_table_lock);
256         __vsock_insert_bound(vsock_unbound_sockets, vsk);
257         spin_unlock_bh(&vsock_table_lock);
258 }
259 
260 void vsock_insert_connected(struct vsock_sock *vsk)
261 {
262         struct list_head *list = vsock_connected_sockets(
263                 &vsk->remote_addr, &vsk->local_addr);
264 
265         spin_lock_bh(&vsock_table_lock);
266         __vsock_insert_connected(list, vsk);
267         spin_unlock_bh(&vsock_table_lock);
268 }
269 EXPORT_SYMBOL_GPL(vsock_insert_connected);
270 
271 void vsock_remove_bound(struct vsock_sock *vsk)
272 {
273         spin_lock_bh(&vsock_table_lock);
274         __vsock_remove_bound(vsk);
275         spin_unlock_bh(&vsock_table_lock);
276 }
277 EXPORT_SYMBOL_GPL(vsock_remove_bound);
278 
279 void vsock_remove_connected(struct vsock_sock *vsk)
280 {
281         spin_lock_bh(&vsock_table_lock);
282         __vsock_remove_connected(vsk);
283         spin_unlock_bh(&vsock_table_lock);
284 }
285 EXPORT_SYMBOL_GPL(vsock_remove_connected);
286 
287 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
288 {
289         struct sock *sk;
290 
291         spin_lock_bh(&vsock_table_lock);
292         sk = __vsock_find_bound_socket(addr);
293         if (sk)
294                 sock_hold(sk);
295 
296         spin_unlock_bh(&vsock_table_lock);
297 
298         return sk;
299 }
300 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
301 
302 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
303                                          struct sockaddr_vm *dst)
304 {
305         struct sock *sk;
306 
307         spin_lock_bh(&vsock_table_lock);
308         sk = __vsock_find_connected_socket(src, dst);
309         if (sk)
310                 sock_hold(sk);
311 
312         spin_unlock_bh(&vsock_table_lock);
313 
314         return sk;
315 }
316 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
317 
318 static bool vsock_in_bound_table(struct vsock_sock *vsk)
319 {
320         bool ret;
321 
322         spin_lock_bh(&vsock_table_lock);
323         ret = __vsock_in_bound_table(vsk);
324         spin_unlock_bh(&vsock_table_lock);
325 
326         return ret;
327 }
328 
329 static bool vsock_in_connected_table(struct vsock_sock *vsk)
330 {
331         bool ret;
332 
333         spin_lock_bh(&vsock_table_lock);
334         ret = __vsock_in_connected_table(vsk);
335         spin_unlock_bh(&vsock_table_lock);
336 
337         return ret;
338 }
339 
340 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
341 {
342         int i;
343 
344         spin_lock_bh(&vsock_table_lock);
345 
346         for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
347                 struct vsock_sock *vsk;
348                 list_for_each_entry(vsk, &vsock_connected_table[i],
349                                     connected_table)
350                         fn(sk_vsock(vsk));
351         }
352 
353         spin_unlock_bh(&vsock_table_lock);
354 }
355 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
356 
357 void vsock_add_pending(struct sock *listener, struct sock *pending)
358 {
359         struct vsock_sock *vlistener;
360         struct vsock_sock *vpending;
361 
362         vlistener = vsock_sk(listener);
363         vpending = vsock_sk(pending);
364 
365         sock_hold(pending);
366         sock_hold(listener);
367         list_add_tail(&vpending->pending_links, &vlistener->pending_links);
368 }
369 EXPORT_SYMBOL_GPL(vsock_add_pending);
370 
371 void vsock_remove_pending(struct sock *listener, struct sock *pending)
372 {
373         struct vsock_sock *vpending = vsock_sk(pending);
374 
375         list_del_init(&vpending->pending_links);
376         sock_put(listener);
377         sock_put(pending);
378 }
379 EXPORT_SYMBOL_GPL(vsock_remove_pending);
380 
381 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
382 {
383         struct vsock_sock *vlistener;
384         struct vsock_sock *vconnected;
385 
386         vlistener = vsock_sk(listener);
387         vconnected = vsock_sk(connected);
388 
389         sock_hold(connected);
390         sock_hold(listener);
391         list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
392 }
393 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
394 
395 static struct sock *vsock_dequeue_accept(struct sock *listener)
396 {
397         struct vsock_sock *vlistener;
398         struct vsock_sock *vconnected;
399 
400         vlistener = vsock_sk(listener);
401 
402         if (list_empty(&vlistener->accept_queue))
403                 return NULL;
404 
405         vconnected = list_entry(vlistener->accept_queue.next,
406                                 struct vsock_sock, accept_queue);
407 
408         list_del_init(&vconnected->accept_queue);
409         sock_put(listener);
410         /* The caller will need a reference on the connected socket so we let
411          * it call sock_put().
412          */
413 
414         return sk_vsock(vconnected);
415 }
416 
417 static bool vsock_is_accept_queue_empty(struct sock *sk)
418 {
419         struct vsock_sock *vsk = vsock_sk(sk);
420         return list_empty(&vsk->accept_queue);
421 }
422 
423 static bool vsock_is_pending(struct sock *sk)
424 {
425         struct vsock_sock *vsk = vsock_sk(sk);
426         return !list_empty(&vsk->pending_links);
427 }
428 
429 static int vsock_send_shutdown(struct sock *sk, int mode)
430 {
431         return transport->shutdown(vsock_sk(sk), mode);
432 }
433 
434 void vsock_pending_work(struct work_struct *work)
435 {
436         struct sock *sk;
437         struct sock *listener;
438         struct vsock_sock *vsk;
439         bool cleanup;
440 
441         vsk = container_of(work, struct vsock_sock, dwork.work);
442         sk = sk_vsock(vsk);
443         listener = vsk->listener;
444         cleanup = true;
445 
446         lock_sock(listener);
447         lock_sock(sk);
448 
449         if (vsock_is_pending(sk)) {
450                 vsock_remove_pending(listener, sk);
451         } else if (!vsk->rejected) {
452                 /* We are not on the pending list and accept() did not reject
453                  * us, so we must have been accepted by our user process.  We
454                  * just need to drop our references to the sockets and be on
455                  * our way.
456                  */
457                 cleanup = false;
458                 goto out;
459         }
460 
461         listener->sk_ack_backlog--;
462 
463         /* We need to remove ourself from the global connected sockets list so
464          * incoming packets can't find this socket, and to reduce the reference
465          * count.
466          */
467         if (vsock_in_connected_table(vsk))
468                 vsock_remove_connected(vsk);
469 
470         sk->sk_state = SS_FREE;
471 
472 out:
473         release_sock(sk);
474         release_sock(listener);
475         if (cleanup)
476                 sock_put(sk);
477 
478         sock_put(sk);
479         sock_put(listener);
480 }
481 EXPORT_SYMBOL_GPL(vsock_pending_work);
482 
483 /**** SOCKET OPERATIONS ****/
484 
485 static int __vsock_bind_stream(struct vsock_sock *vsk,
486                                struct sockaddr_vm *addr)
487 {
488         static u32 port = LAST_RESERVED_PORT + 1;
489         struct sockaddr_vm new_addr;
490 
491         vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
492 
493         if (addr->svm_port == VMADDR_PORT_ANY) {
494                 bool found = false;
495                 unsigned int i;
496 
497                 for (i = 0; i < MAX_PORT_RETRIES; i++) {
498                         if (port <= LAST_RESERVED_PORT)
499                                 port = LAST_RESERVED_PORT + 1;
500 
501                         new_addr.svm_port = port++;
502 
503                         if (!__vsock_find_bound_socket(&new_addr)) {
504                                 found = true;
505                                 break;
506                         }
507                 }
508 
509                 if (!found)
510                         return -EADDRNOTAVAIL;
511         } else {
512                 /* If port is in reserved range, ensure caller
513                  * has necessary privileges.
514                  */
515                 if (addr->svm_port <= LAST_RESERVED_PORT &&
516                     !capable(CAP_NET_BIND_SERVICE)) {
517                         return -EACCES;
518                 }
519 
520                 if (__vsock_find_bound_socket(&new_addr))
521                         return -EADDRINUSE;
522         }
523 
524         vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
525 
526         /* Remove stream sockets from the unbound list and add them to the hash
527          * table for easy lookup by its address.  The unbound list is simply an
528          * extra entry at the end of the hash table, a trick used by AF_UNIX.
529          */
530         __vsock_remove_bound(vsk);
531         __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
532 
533         return 0;
534 }
535 
536 static int __vsock_bind_dgram(struct vsock_sock *vsk,
537                               struct sockaddr_vm *addr)
538 {
539         return transport->dgram_bind(vsk, addr);
540 }
541 
542 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
543 {
544         struct vsock_sock *vsk = vsock_sk(sk);
545         u32 cid;
546         int retval;
547 
548         /* First ensure this socket isn't already bound. */
549         if (vsock_addr_bound(&vsk->local_addr))
550                 return -EINVAL;
551 
552         /* Now bind to the provided address or select appropriate values if
553          * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
554          * like AF_INET prevents binding to a non-local IP address (in most
555          * cases), we only allow binding to the local CID.
556          */
557         cid = transport->get_local_cid();
558         if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)
559                 return -EADDRNOTAVAIL;
560 
561         switch (sk->sk_socket->type) {
562         case SOCK_STREAM:
563                 spin_lock_bh(&vsock_table_lock);
564                 retval = __vsock_bind_stream(vsk, addr);
565                 spin_unlock_bh(&vsock_table_lock);
566                 break;
567 
568         case SOCK_DGRAM:
569                 retval = __vsock_bind_dgram(vsk, addr);
570                 break;
571 
572         default:
573                 retval = -EINVAL;
574                 break;
575         }
576 
577         return retval;
578 }
579 
580 struct sock *__vsock_create(struct net *net,
581                             struct socket *sock,
582                             struct sock *parent,
583                             gfp_t priority,
584                             unsigned short type)
585 {
586         struct sock *sk;
587         struct vsock_sock *psk;
588         struct vsock_sock *vsk;
589 
590         sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto);
591         if (!sk)
592                 return NULL;
593 
594         sock_init_data(sock, sk);
595 
596         /* sk->sk_type is normally set in sock_init_data, but only if sock is
597          * non-NULL. We make sure that our sockets always have a type by
598          * setting it here if needed.
599          */
600         if (!sock)
601                 sk->sk_type = type;
602 
603         vsk = vsock_sk(sk);
604         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
605         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
606 
607         sk->sk_destruct = vsock_sk_destruct;
608         sk->sk_backlog_rcv = vsock_queue_rcv_skb;
609         sk->sk_state = 0;
610         sock_reset_flag(sk, SOCK_DONE);
611 
612         INIT_LIST_HEAD(&vsk->bound_table);
613         INIT_LIST_HEAD(&vsk->connected_table);
614         vsk->listener = NULL;
615         INIT_LIST_HEAD(&vsk->pending_links);
616         INIT_LIST_HEAD(&vsk->accept_queue);
617         vsk->rejected = false;
618         vsk->sent_request = false;
619         vsk->ignore_connecting_rst = false;
620         vsk->peer_shutdown = 0;
621 
622         psk = parent ? vsock_sk(parent) : NULL;
623         if (parent) {
624                 vsk->trusted = psk->trusted;
625                 vsk->owner = get_cred(psk->owner);
626                 vsk->connect_timeout = psk->connect_timeout;
627         } else {
628                 vsk->trusted = capable(CAP_NET_ADMIN);
629                 vsk->owner = get_current_cred();
630                 vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
631         }
632 
633         if (transport->init(vsk, psk) < 0) {
634                 sk_free(sk);
635                 return NULL;
636         }
637 
638         if (sock)
639                 vsock_insert_unbound(vsk);
640 
641         return sk;
642 }
643 EXPORT_SYMBOL_GPL(__vsock_create);
644 
645 static void __vsock_release(struct sock *sk)
646 {
647         if (sk) {
648                 struct sk_buff *skb;
649                 struct sock *pending;
650                 struct vsock_sock *vsk;
651 
652                 vsk = vsock_sk(sk);
653                 pending = NULL; /* Compiler warning. */
654 
655                 if (vsock_in_bound_table(vsk))
656                         vsock_remove_bound(vsk);
657 
658                 if (vsock_in_connected_table(vsk))
659                         vsock_remove_connected(vsk);
660 
661                 transport->release(vsk);
662 
663                 lock_sock(sk);
664                 sock_orphan(sk);
665                 sk->sk_shutdown = SHUTDOWN_MASK;
666 
667                 while ((skb = skb_dequeue(&sk->sk_receive_queue)))
668                         kfree_skb(skb);
669 
670                 /* Clean up any sockets that never were accepted. */
671                 while ((pending = vsock_dequeue_accept(sk)) != NULL) {
672                         __vsock_release(pending);
673                         sock_put(pending);
674                 }
675 
676                 release_sock(sk);
677                 sock_put(sk);
678         }
679 }
680 
681 static void vsock_sk_destruct(struct sock *sk)
682 {
683         struct vsock_sock *vsk = vsock_sk(sk);
684 
685         transport->destruct(vsk);
686 
687         /* When clearing these addresses, there's no need to set the family and
688          * possibly register the address family with the kernel.
689          */
690         vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
691         vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
692 
693         put_cred(vsk->owner);
694 }
695 
696 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
697 {
698         int err;
699 
700         err = sock_queue_rcv_skb(sk, skb);
701         if (err)
702                 kfree_skb(skb);
703 
704         return err;
705 }
706 
707 s64 vsock_stream_has_data(struct vsock_sock *vsk)
708 {
709         return transport->stream_has_data(vsk);
710 }
711 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
712 
713 s64 vsock_stream_has_space(struct vsock_sock *vsk)
714 {
715         return transport->stream_has_space(vsk);
716 }
717 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
718 
719 static int vsock_release(struct socket *sock)
720 {
721         __vsock_release(sock->sk);
722         sock->sk = NULL;
723         sock->state = SS_FREE;
724 
725         return 0;
726 }
727 
728 static int
729 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
730 {
731         int err;
732         struct sock *sk;
733         struct sockaddr_vm *vm_addr;
734 
735         sk = sock->sk;
736 
737         if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
738                 return -EINVAL;
739 
740         lock_sock(sk);
741         err = __vsock_bind(sk, vm_addr);
742         release_sock(sk);
743 
744         return err;
745 }
746 
747 static int vsock_getname(struct socket *sock,
748                          struct sockaddr *addr, int *addr_len, int peer)
749 {
750         int err;
751         struct sock *sk;
752         struct vsock_sock *vsk;
753         struct sockaddr_vm *vm_addr;
754 
755         sk = sock->sk;
756         vsk = vsock_sk(sk);
757         err = 0;
758 
759         lock_sock(sk);
760 
761         if (peer) {
762                 if (sock->state != SS_CONNECTED) {
763                         err = -ENOTCONN;
764                         goto out;
765                 }
766                 vm_addr = &vsk->remote_addr;
767         } else {
768                 vm_addr = &vsk->local_addr;
769         }
770 
771         if (!vm_addr) {
772                 err = -EINVAL;
773                 goto out;
774         }
775 
776         /* sys_getsockname() and sys_getpeername() pass us a
777          * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
778          * that macro is defined in socket.c instead of .h, so we hardcode its
779          * value here.
780          */
781         BUILD_BUG_ON(sizeof(*vm_addr) > 128);
782         memcpy(addr, vm_addr, sizeof(*vm_addr));
783         *addr_len = sizeof(*vm_addr);
784 
785 out:
786         release_sock(sk);
787         return err;
788 }
789 
790 static int vsock_shutdown(struct socket *sock, int mode)
791 {
792         int err;
793         struct sock *sk;
794 
795         /* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
796          * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
797          * here like the other address families do.  Note also that the
798          * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
799          * which is what we want.
800          */
801         mode++;
802 
803         if ((mode & ~SHUTDOWN_MASK) || !mode)
804                 return -EINVAL;
805 
806         /* If this is a STREAM socket and it is not connected then bail out
807          * immediately.  If it is a DGRAM socket then we must first kick the
808          * socket so that it wakes up from any sleeping calls, for example
809          * recv(), and then afterwards return the error.
810          */
811 
812         sk = sock->sk;
813         if (sock->state == SS_UNCONNECTED) {
814                 err = -ENOTCONN;
815                 if (sk->sk_type == SOCK_STREAM)
816                         return err;
817         } else {
818                 sock->state = SS_DISCONNECTING;
819                 err = 0;
820         }
821 
822         /* Receive and send shutdowns are treated alike. */
823         mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
824         if (mode) {
825                 lock_sock(sk);
826                 sk->sk_shutdown |= mode;
827                 sk->sk_state_change(sk);
828                 release_sock(sk);
829 
830                 if (sk->sk_type == SOCK_STREAM) {
831                         sock_reset_flag(sk, SOCK_DONE);
832                         vsock_send_shutdown(sk, mode);
833                 }
834         }
835 
836         return err;
837 }
838 
839 static unsigned int vsock_poll(struct file *file, struct socket *sock,
840                                poll_table *wait)
841 {
842         struct sock *sk;
843         unsigned int mask;
844         struct vsock_sock *vsk;
845 
846         sk = sock->sk;
847         vsk = vsock_sk(sk);
848 
849         poll_wait(file, sk_sleep(sk), wait);
850         mask = 0;
851 
852         if (sk->sk_err)
853                 /* Signify that there has been an error on this socket. */
854                 mask |= POLLERR;
855 
856         /* INET sockets treat local write shutdown and peer write shutdown as a
857          * case of POLLHUP set.
858          */
859         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
860             ((sk->sk_shutdown & SEND_SHUTDOWN) &&
861              (vsk->peer_shutdown & SEND_SHUTDOWN))) {
862                 mask |= POLLHUP;
863         }
864 
865         if (sk->sk_shutdown & RCV_SHUTDOWN ||
866             vsk->peer_shutdown & SEND_SHUTDOWN) {
867                 mask |= POLLRDHUP;
868         }
869 
870         if (sock->type == SOCK_DGRAM) {
871                 /* For datagram sockets we can read if there is something in
872                  * the queue and write as long as the socket isn't shutdown for
873                  * sending.
874                  */
875                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
876                     (sk->sk_shutdown & RCV_SHUTDOWN)) {
877                         mask |= POLLIN | POLLRDNORM;
878                 }
879 
880                 if (!(sk->sk_shutdown & SEND_SHUTDOWN))
881                         mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
882 
883         } else if (sock->type == SOCK_STREAM) {
884                 lock_sock(sk);
885 
886                 /* Listening sockets that have connections in their accept
887                  * queue can be read.
888                  */
889                 if (sk->sk_state == SS_LISTEN
890                     && !vsock_is_accept_queue_empty(sk))
891                         mask |= POLLIN | POLLRDNORM;
892 
893                 /* If there is something in the queue then we can read. */
894                 if (transport->stream_is_active(vsk) &&
895                     !(sk->sk_shutdown & RCV_SHUTDOWN)) {
896                         bool data_ready_now = false;
897                         int ret = transport->notify_poll_in(
898                                         vsk, 1, &data_ready_now);
899                         if (ret < 0) {
900                                 mask |= POLLERR;
901                         } else {
902                                 if (data_ready_now)
903                                         mask |= POLLIN | POLLRDNORM;
904 
905                         }
906                 }
907 
908                 /* Sockets whose connections have been closed, reset, or
909                  * terminated should also be considered read, and we check the
910                  * shutdown flag for that.
911                  */
912                 if (sk->sk_shutdown & RCV_SHUTDOWN ||
913                     vsk->peer_shutdown & SEND_SHUTDOWN) {
914                         mask |= POLLIN | POLLRDNORM;
915                 }
916 
917                 /* Connected sockets that can produce data can be written. */
918                 if (sk->sk_state == SS_CONNECTED) {
919                         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
920                                 bool space_avail_now = false;
921                                 int ret = transport->notify_poll_out(
922                                                 vsk, 1, &space_avail_now);
923                                 if (ret < 0) {
924                                         mask |= POLLERR;
925                                 } else {
926                                         if (space_avail_now)
927                                                 /* Remove POLLWRBAND since INET
928                                                  * sockets are not setting it.
929                                                  */
930                                                 mask |= POLLOUT | POLLWRNORM;
931 
932                                 }
933                         }
934                 }
935 
936                 /* Simulate INET socket poll behaviors, which sets
937                  * POLLOUT|POLLWRNORM when peer is closed and nothing to read,
938                  * but local send is not shutdown.
939                  */
940                 if (sk->sk_state == SS_UNCONNECTED) {
941                         if (!(sk->sk_shutdown & SEND_SHUTDOWN))
942                                 mask |= POLLOUT | POLLWRNORM;
943 
944                 }
945 
946                 release_sock(sk);
947         }
948 
949         return mask;
950 }
951 
952 static int vsock_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
953                                struct msghdr *msg, size_t len)
954 {
955         int err;
956         struct sock *sk;
957         struct vsock_sock *vsk;
958         struct sockaddr_vm *remote_addr;
959 
960         if (msg->msg_flags & MSG_OOB)
961                 return -EOPNOTSUPP;
962 
963         /* For now, MSG_DONTWAIT is always assumed... */
964         err = 0;
965         sk = sock->sk;
966         vsk = vsock_sk(sk);
967 
968         lock_sock(sk);
969 
970         err = vsock_auto_bind(vsk);
971         if (err)
972                 goto out;
973 
974 
975         /* If the provided message contains an address, use that.  Otherwise
976          * fall back on the socket's remote handle (if it has been connected).
977          */
978         if (msg->msg_name &&
979             vsock_addr_cast(msg->msg_name, msg->msg_namelen,
980                             &remote_addr) == 0) {
981                 /* Ensure this address is of the right type and is a valid
982                  * destination.
983                  */
984 
985                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
986                         remote_addr->svm_cid = transport->get_local_cid();
987 
988                 if (!vsock_addr_bound(remote_addr)) {
989                         err = -EINVAL;
990                         goto out;
991                 }
992         } else if (sock->state == SS_CONNECTED) {
993                 remote_addr = &vsk->remote_addr;
994 
995                 if (remote_addr->svm_cid == VMADDR_CID_ANY)
996                         remote_addr->svm_cid = transport->get_local_cid();
997 
998                 /* XXX Should connect() or this function ensure remote_addr is
999                  * bound?
1000                  */
1001                 if (!vsock_addr_bound(&vsk->remote_addr)) {
1002                         err = -EINVAL;
1003                         goto out;
1004                 }
1005         } else {
1006                 err = -EINVAL;
1007                 goto out;
1008         }
1009 
1010         if (!transport->dgram_allow(remote_addr->svm_cid,
1011                                     remote_addr->svm_port)) {
1012                 err = -EINVAL;
1013                 goto out;
1014         }
1015 
1016         err = transport->dgram_enqueue(vsk, remote_addr, msg->msg_iov, len);
1017 
1018 out:
1019         release_sock(sk);
1020         return err;
1021 }
1022 
1023 static int vsock_dgram_connect(struct socket *sock,
1024                                struct sockaddr *addr, int addr_len, int flags)
1025 {
1026         int err;
1027         struct sock *sk;
1028         struct vsock_sock *vsk;
1029         struct sockaddr_vm *remote_addr;
1030 
1031         sk = sock->sk;
1032         vsk = vsock_sk(sk);
1033 
1034         err = vsock_addr_cast(addr, addr_len, &remote_addr);
1035         if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1036                 lock_sock(sk);
1037                 vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1038                                 VMADDR_PORT_ANY);
1039                 sock->state = SS_UNCONNECTED;
1040                 release_sock(sk);
1041                 return 0;
1042         } else if (err != 0)
1043                 return -EINVAL;
1044 
1045         lock_sock(sk);
1046 
1047         err = vsock_auto_bind(vsk);
1048         if (err)
1049                 goto out;
1050 
1051         if (!transport->dgram_allow(remote_addr->svm_cid,
1052                                     remote_addr->svm_port)) {
1053                 err = -EINVAL;
1054                 goto out;
1055         }
1056 
1057         memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1058         sock->state = SS_CONNECTED;
1059 
1060 out:
1061         release_sock(sk);
1062         return err;
1063 }
1064 
1065 static int vsock_dgram_recvmsg(struct kiocb *kiocb, struct socket *sock,
1066                                struct msghdr *msg, size_t len, int flags)
1067 {
1068         return transport->dgram_dequeue(kiocb, vsock_sk(sock->sk), msg, len,
1069                                         flags);
1070 }
1071 
1072 static const struct proto_ops vsock_dgram_ops = {
1073         .family = PF_VSOCK,
1074         .owner = THIS_MODULE,
1075         .release = vsock_release,
1076         .bind = vsock_bind,
1077         .connect = vsock_dgram_connect,
1078         .socketpair = sock_no_socketpair,
1079         .accept = sock_no_accept,
1080         .getname = vsock_getname,
1081         .poll = vsock_poll,
1082         .ioctl = sock_no_ioctl,
1083         .listen = sock_no_listen,
1084         .shutdown = vsock_shutdown,
1085         .setsockopt = sock_no_setsockopt,
1086         .getsockopt = sock_no_getsockopt,
1087         .sendmsg = vsock_dgram_sendmsg,
1088         .recvmsg = vsock_dgram_recvmsg,
1089         .mmap = sock_no_mmap,
1090         .sendpage = sock_no_sendpage,
1091 };
1092 
1093 static void vsock_connect_timeout(struct work_struct *work)
1094 {
1095         struct sock *sk;
1096         struct vsock_sock *vsk;
1097 
1098         vsk = container_of(work, struct vsock_sock, dwork.work);
1099         sk = sk_vsock(vsk);
1100 
1101         lock_sock(sk);
1102         if (sk->sk_state == SS_CONNECTING &&
1103             (sk->sk_shutdown != SHUTDOWN_MASK)) {
1104                 sk->sk_state = SS_UNCONNECTED;
1105                 sk->sk_err = ETIMEDOUT;
1106                 sk->sk_error_report(sk);
1107         }
1108         release_sock(sk);
1109 
1110         sock_put(sk);
1111 }
1112 
1113 static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
1114                                 int addr_len, int flags)
1115 {
1116         int err;
1117         struct sock *sk;
1118         struct vsock_sock *vsk;
1119         struct sockaddr_vm *remote_addr;
1120         long timeout;
1121         DEFINE_WAIT(wait);
1122 
1123         err = 0;
1124         sk = sock->sk;
1125         vsk = vsock_sk(sk);
1126 
1127         lock_sock(sk);
1128 
1129         /* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1130         switch (sock->state) {
1131         case SS_CONNECTED:
1132                 err = -EISCONN;
1133                 goto out;
1134         case SS_DISCONNECTING:
1135                 err = -EINVAL;
1136                 goto out;
1137         case SS_CONNECTING:
1138                 /* This continues on so we can move sock into the SS_CONNECTED
1139                  * state once the connection has completed (at which point err
1140                  * will be set to zero also).  Otherwise, we will either wait
1141                  * for the connection or return -EALREADY should this be a
1142                  * non-blocking call.
1143                  */
1144                 err = -EALREADY;
1145                 break;
1146         default:
1147                 if ((sk->sk_state == SS_LISTEN) ||
1148                     vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1149                         err = -EINVAL;
1150                         goto out;
1151                 }
1152 
1153                 /* The hypervisor and well-known contexts do not have socket
1154                  * endpoints.
1155                  */
1156                 if (!transport->stream_allow(remote_addr->svm_cid,
1157                                              remote_addr->svm_port)) {
1158                         err = -ENETUNREACH;
1159                         goto out;
1160                 }
1161 
1162                 /* Set the remote address that we are connecting to. */
1163                 memcpy(&vsk->remote_addr, remote_addr,
1164                        sizeof(vsk->remote_addr));
1165 
1166                 err = vsock_auto_bind(vsk);
1167                 if (err)
1168                         goto out;
1169 
1170                 sk->sk_state = SS_CONNECTING;
1171 
1172                 err = transport->connect(vsk);
1173                 if (err < 0)
1174                         goto out;
1175 
1176                 /* Mark sock as connecting and set the error code to in
1177                  * progress in case this is a non-blocking connect.
1178                  */
1179                 sock->state = SS_CONNECTING;
1180                 err = -EINPROGRESS;
1181         }
1182 
1183         /* The receive path will handle all communication until we are able to
1184          * enter the connected state.  Here we wait for the connection to be
1185          * completed or a notification of an error.
1186          */
1187         timeout = vsk->connect_timeout;
1188         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1189 
1190         while (sk->sk_state != SS_CONNECTED && sk->sk_err == 0) {
1191                 if (flags & O_NONBLOCK) {
1192                         /* If we're not going to block, we schedule a timeout
1193                          * function to generate a timeout on the connection
1194                          * attempt, in case the peer doesn't respond in a
1195                          * timely manner. We hold on to the socket until the
1196                          * timeout fires.
1197                          */
1198                         sock_hold(sk);
1199                         INIT_DELAYED_WORK(&vsk->dwork,
1200                                           vsock_connect_timeout);
1201                         schedule_delayed_work(&vsk->dwork, timeout);
1202 
1203                         /* Skip ahead to preserve error code set above. */
1204                         goto out_wait;
1205                 }
1206 
1207                 release_sock(sk);
1208                 timeout = schedule_timeout(timeout);
1209                 lock_sock(sk);
1210 
1211                 if (signal_pending(current)) {
1212                         err = sock_intr_errno(timeout);
1213                         goto out_wait_error;
1214                 } else if (timeout == 0) {
1215                         err = -ETIMEDOUT;
1216                         goto out_wait_error;
1217                 }
1218 
1219                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1220         }
1221 
1222         if (sk->sk_err) {
1223                 err = -sk->sk_err;
1224                 goto out_wait_error;
1225         } else
1226                 err = 0;
1227 
1228 out_wait:
1229         finish_wait(sk_sleep(sk), &wait);
1230 out:
1231         release_sock(sk);
1232         return err;
1233 
1234 out_wait_error:
1235         sk->sk_state = SS_UNCONNECTED;
1236         sock->state = SS_UNCONNECTED;
1237         goto out_wait;
1238 }
1239 
1240 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags)
1241 {
1242         struct sock *listener;
1243         int err;
1244         struct sock *connected;
1245         struct vsock_sock *vconnected;
1246         long timeout;
1247         DEFINE_WAIT(wait);
1248 
1249         err = 0;
1250         listener = sock->sk;
1251 
1252         lock_sock(listener);
1253 
1254         if (sock->type != SOCK_STREAM) {
1255                 err = -EOPNOTSUPP;
1256                 goto out;
1257         }
1258 
1259         if (listener->sk_state != SS_LISTEN) {
1260                 err = -EINVAL;
1261                 goto out;
1262         }
1263 
1264         /* Wait for children sockets to appear; these are the new sockets
1265          * created upon connection establishment.
1266          */
1267         timeout = sock_sndtimeo(listener, flags & O_NONBLOCK);
1268         prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1269 
1270         while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1271                listener->sk_err == 0) {
1272                 release_sock(listener);
1273                 timeout = schedule_timeout(timeout);
1274                 lock_sock(listener);
1275 
1276                 if (signal_pending(current)) {
1277                         err = sock_intr_errno(timeout);
1278                         goto out_wait;
1279                 } else if (timeout == 0) {
1280                         err = -EAGAIN;
1281                         goto out_wait;
1282                 }
1283 
1284                 prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1285         }
1286 
1287         if (listener->sk_err)
1288                 err = -listener->sk_err;
1289 
1290         if (connected) {
1291                 listener->sk_ack_backlog--;
1292 
1293                 lock_sock(connected);
1294                 vconnected = vsock_sk(connected);
1295 
1296                 /* If the listener socket has received an error, then we should
1297                  * reject this socket and return.  Note that we simply mark the
1298                  * socket rejected, drop our reference, and let the cleanup
1299                  * function handle the cleanup; the fact that we found it in
1300                  * the listener's accept queue guarantees that the cleanup
1301                  * function hasn't run yet.
1302                  */
1303                 if (err) {
1304                         vconnected->rejected = true;
1305                         release_sock(connected);
1306                         sock_put(connected);
1307                         goto out_wait;
1308                 }
1309 
1310                 newsock->state = SS_CONNECTED;
1311                 sock_graft(connected, newsock);
1312                 release_sock(connected);
1313                 sock_put(connected);
1314         }
1315 
1316 out_wait:
1317         finish_wait(sk_sleep(listener), &wait);
1318 out:
1319         release_sock(listener);
1320         return err;
1321 }
1322 
1323 static int vsock_listen(struct socket *sock, int backlog)
1324 {
1325         int err;
1326         struct sock *sk;
1327         struct vsock_sock *vsk;
1328 
1329         sk = sock->sk;
1330 
1331         lock_sock(sk);
1332 
1333         if (sock->type != SOCK_STREAM) {
1334                 err = -EOPNOTSUPP;
1335                 goto out;
1336         }
1337 
1338         if (sock->state != SS_UNCONNECTED) {
1339                 err = -EINVAL;
1340                 goto out;
1341         }
1342 
1343         vsk = vsock_sk(sk);
1344 
1345         if (!vsock_addr_bound(&vsk->local_addr)) {
1346                 err = -EINVAL;
1347                 goto out;
1348         }
1349 
1350         sk->sk_max_ack_backlog = backlog;
1351         sk->sk_state = SS_LISTEN;
1352 
1353         err = 0;
1354 
1355 out:
1356         release_sock(sk);
1357         return err;
1358 }
1359 
1360 static int vsock_stream_setsockopt(struct socket *sock,
1361                                    int level,
1362                                    int optname,
1363                                    char __user *optval,
1364                                    unsigned int optlen)
1365 {
1366         int err;
1367         struct sock *sk;
1368         struct vsock_sock *vsk;
1369         u64 val;
1370 
1371         if (level != AF_VSOCK)
1372                 return -ENOPROTOOPT;
1373 
1374 #define COPY_IN(_v)                                       \
1375         do {                                              \
1376                 if (optlen < sizeof(_v)) {                \
1377                         err = -EINVAL;                    \
1378                         goto exit;                        \
1379                 }                                         \
1380                 if (copy_from_user(&_v, optval, sizeof(_v)) != 0) {     \
1381                         err = -EFAULT;                                  \
1382                         goto exit;                                      \
1383                 }                                                       \
1384         } while (0)
1385 
1386         err = 0;
1387         sk = sock->sk;
1388         vsk = vsock_sk(sk);
1389 
1390         lock_sock(sk);
1391 
1392         switch (optname) {
1393         case SO_VM_SOCKETS_BUFFER_SIZE:
1394                 COPY_IN(val);
1395                 transport->set_buffer_size(vsk, val);
1396                 break;
1397 
1398         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1399                 COPY_IN(val);
1400                 transport->set_max_buffer_size(vsk, val);
1401                 break;
1402 
1403         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1404                 COPY_IN(val);
1405                 transport->set_min_buffer_size(vsk, val);
1406                 break;
1407 
1408         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1409                 struct timeval tv;
1410                 COPY_IN(tv);
1411                 if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1412                     tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1413                         vsk->connect_timeout = tv.tv_sec * HZ +
1414                             DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1415                         if (vsk->connect_timeout == 0)
1416                                 vsk->connect_timeout =
1417                                     VSOCK_DEFAULT_CONNECT_TIMEOUT;
1418 
1419                 } else {
1420                         err = -ERANGE;
1421                 }
1422                 break;
1423         }
1424 
1425         default:
1426                 err = -ENOPROTOOPT;
1427                 break;
1428         }
1429 
1430 #undef COPY_IN
1431 
1432 exit:
1433         release_sock(sk);
1434         return err;
1435 }
1436 
1437 static int vsock_stream_getsockopt(struct socket *sock,
1438                                    int level, int optname,
1439                                    char __user *optval,
1440                                    int __user *optlen)
1441 {
1442         int err;
1443         int len;
1444         struct sock *sk;
1445         struct vsock_sock *vsk;
1446         u64 val;
1447 
1448         if (level != AF_VSOCK)
1449                 return -ENOPROTOOPT;
1450 
1451         err = get_user(len, optlen);
1452         if (err != 0)
1453                 return err;
1454 
1455 #define COPY_OUT(_v)                            \
1456         do {                                    \
1457                 if (len < sizeof(_v))           \
1458                         return -EINVAL;         \
1459                                                 \
1460                 len = sizeof(_v);               \
1461                 if (copy_to_user(optval, &_v, len) != 0)        \
1462                         return -EFAULT;                         \
1463                                                                 \
1464         } while (0)
1465 
1466         err = 0;
1467         sk = sock->sk;
1468         vsk = vsock_sk(sk);
1469 
1470         switch (optname) {
1471         case SO_VM_SOCKETS_BUFFER_SIZE:
1472                 val = transport->get_buffer_size(vsk);
1473                 COPY_OUT(val);
1474                 break;
1475 
1476         case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1477                 val = transport->get_max_buffer_size(vsk);
1478                 COPY_OUT(val);
1479                 break;
1480 
1481         case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1482                 val = transport->get_min_buffer_size(vsk);
1483                 COPY_OUT(val);
1484                 break;
1485 
1486         case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1487                 struct timeval tv;
1488                 tv.tv_sec = vsk->connect_timeout / HZ;
1489                 tv.tv_usec =
1490                     (vsk->connect_timeout -
1491                      tv.tv_sec * HZ) * (1000000 / HZ);
1492                 COPY_OUT(tv);
1493                 break;
1494         }
1495         default:
1496                 return -ENOPROTOOPT;
1497         }
1498 
1499         err = put_user(len, optlen);
1500         if (err != 0)
1501                 return -EFAULT;
1502 
1503 #undef COPY_OUT
1504 
1505         return 0;
1506 }
1507 
1508 static int vsock_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
1509                                 struct msghdr *msg, size_t len)
1510 {
1511         struct sock *sk;
1512         struct vsock_sock *vsk;
1513         ssize_t total_written;
1514         long timeout;
1515         int err;
1516         struct vsock_transport_send_notify_data send_data;
1517 
1518         DEFINE_WAIT(wait);
1519 
1520         sk = sock->sk;
1521         vsk = vsock_sk(sk);
1522         total_written = 0;
1523         err = 0;
1524 
1525         if (msg->msg_flags & MSG_OOB)
1526                 return -EOPNOTSUPP;
1527 
1528         lock_sock(sk);
1529 
1530         /* Callers should not provide a destination with stream sockets. */
1531         if (msg->msg_namelen) {
1532                 err = sk->sk_state == SS_CONNECTED ? -EISCONN : -EOPNOTSUPP;
1533                 goto out;
1534         }
1535 
1536         /* Send data only if both sides are not shutdown in the direction. */
1537         if (sk->sk_shutdown & SEND_SHUTDOWN ||
1538             vsk->peer_shutdown & RCV_SHUTDOWN) {
1539                 err = -EPIPE;
1540                 goto out;
1541         }
1542 
1543         if (sk->sk_state != SS_CONNECTED ||
1544             !vsock_addr_bound(&vsk->local_addr)) {
1545                 err = -ENOTCONN;
1546                 goto out;
1547         }
1548 
1549         if (!vsock_addr_bound(&vsk->remote_addr)) {
1550                 err = -EDESTADDRREQ;
1551                 goto out;
1552         }
1553 
1554         /* Wait for room in the produce queue to enqueue our user's data. */
1555         timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1556 
1557         err = transport->notify_send_init(vsk, &send_data);
1558         if (err < 0)
1559                 goto out;
1560 
1561         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1562 
1563         while (total_written < len) {
1564                 ssize_t written;
1565 
1566                 while (vsock_stream_has_space(vsk) == 0 &&
1567                        sk->sk_err == 0 &&
1568                        !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1569                        !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1570 
1571                         /* Don't wait for non-blocking sockets. */
1572                         if (timeout == 0) {
1573                                 err = -EAGAIN;
1574                                 goto out_wait;
1575                         }
1576 
1577                         err = transport->notify_send_pre_block(vsk, &send_data);
1578                         if (err < 0)
1579                                 goto out_wait;
1580 
1581                         release_sock(sk);
1582                         timeout = schedule_timeout(timeout);
1583                         lock_sock(sk);
1584                         if (signal_pending(current)) {
1585                                 err = sock_intr_errno(timeout);
1586                                 goto out_wait;
1587                         } else if (timeout == 0) {
1588                                 err = -EAGAIN;
1589                                 goto out_wait;
1590                         }
1591 
1592                         prepare_to_wait(sk_sleep(sk), &wait,
1593                                         TASK_INTERRUPTIBLE);
1594                 }
1595 
1596                 /* These checks occur both as part of and after the loop
1597                  * conditional since we need to check before and after
1598                  * sleeping.
1599                  */
1600                 if (sk->sk_err) {
1601                         err = -sk->sk_err;
1602                         goto out_wait;
1603                 } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1604                            (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1605                         err = -EPIPE;
1606                         goto out_wait;
1607                 }
1608 
1609                 err = transport->notify_send_pre_enqueue(vsk, &send_data);
1610                 if (err < 0)
1611                         goto out_wait;
1612 
1613                 /* Note that enqueue will only write as many bytes as are free
1614                  * in the produce queue, so we don't need to ensure len is
1615                  * smaller than the queue size.  It is the caller's
1616                  * responsibility to check how many bytes we were able to send.
1617                  */
1618 
1619                 written = transport->stream_enqueue(
1620                                 vsk, msg->msg_iov,
1621                                 len - total_written);
1622                 if (written < 0) {
1623                         err = -ENOMEM;
1624                         goto out_wait;
1625                 }
1626 
1627                 total_written += written;
1628 
1629                 err = transport->notify_send_post_enqueue(
1630                                 vsk, written, &send_data);
1631                 if (err < 0)
1632                         goto out_wait;
1633 
1634         }
1635 
1636 out_wait:
1637         if (total_written > 0)
1638                 err = total_written;
1639         finish_wait(sk_sleep(sk), &wait);
1640 out:
1641         release_sock(sk);
1642         return err;
1643 }
1644 
1645 
1646 static int
1647 vsock_stream_recvmsg(struct kiocb *kiocb,
1648                      struct socket *sock,
1649                      struct msghdr *msg, size_t len, int flags)
1650 {
1651         struct sock *sk;
1652         struct vsock_sock *vsk;
1653         int err;
1654         size_t target;
1655         ssize_t copied;
1656         long timeout;
1657         struct vsock_transport_recv_notify_data recv_data;
1658 
1659         DEFINE_WAIT(wait);
1660 
1661         sk = sock->sk;
1662         vsk = vsock_sk(sk);
1663         err = 0;
1664 
1665         lock_sock(sk);
1666 
1667         if (sk->sk_state != SS_CONNECTED) {
1668                 /* Recvmsg is supposed to return 0 if a peer performs an
1669                  * orderly shutdown. Differentiate between that case and when a
1670                  * peer has not connected or a local shutdown occured with the
1671                  * SOCK_DONE flag.
1672                  */
1673                 if (sock_flag(sk, SOCK_DONE))
1674                         err = 0;
1675                 else
1676                         err = -ENOTCONN;
1677 
1678                 goto out;
1679         }
1680 
1681         if (flags & MSG_OOB) {
1682                 err = -EOPNOTSUPP;
1683                 goto out;
1684         }
1685 
1686         /* We don't check peer_shutdown flag here since peer may actually shut
1687          * down, but there can be data in the queue that a local socket can
1688          * receive.
1689          */
1690         if (sk->sk_shutdown & RCV_SHUTDOWN) {
1691                 err = 0;
1692                 goto out;
1693         }
1694 
1695         /* It is valid on Linux to pass in a zero-length receive buffer.  This
1696          * is not an error.  We may as well bail out now.
1697          */
1698         if (!len) {
1699                 err = 0;
1700                 goto out;
1701         }
1702 
1703         /* We must not copy less than target bytes into the user's buffer
1704          * before returning successfully, so we wait for the consume queue to
1705          * have that much data to consume before dequeueing.  Note that this
1706          * makes it impossible to handle cases where target is greater than the
1707          * queue size.
1708          */
1709         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1710         if (target >= transport->stream_rcvhiwat(vsk)) {
1711                 err = -ENOMEM;
1712                 goto out;
1713         }
1714         timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1715         copied = 0;
1716 
1717         err = transport->notify_recv_init(vsk, target, &recv_data);
1718         if (err < 0)
1719                 goto out;
1720 
1721         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1722 
1723         while (1) {
1724                 s64 ready = vsock_stream_has_data(vsk);
1725 
1726                 if (ready < 0) {
1727                         /* Invalid queue pair content. XXX This should be
1728                          * changed to a connection reset in a later change.
1729                          */
1730 
1731                         err = -ENOMEM;
1732                         goto out_wait;
1733                 } else if (ready > 0) {
1734                         ssize_t read;
1735 
1736                         err = transport->notify_recv_pre_dequeue(
1737                                         vsk, target, &recv_data);
1738                         if (err < 0)
1739                                 break;
1740 
1741                         read = transport->stream_dequeue(
1742                                         vsk, msg->msg_iov,
1743                                         len - copied, flags);
1744                         if (read < 0) {
1745                                 err = -ENOMEM;
1746                                 break;
1747                         }
1748 
1749                         copied += read;
1750 
1751                         err = transport->notify_recv_post_dequeue(
1752                                         vsk, target, read,
1753                                         !(flags & MSG_PEEK), &recv_data);
1754                         if (err < 0)
1755                                 goto out_wait;
1756 
1757                         if (read >= target || flags & MSG_PEEK)
1758                                 break;
1759 
1760                         target -= read;
1761                 } else {
1762                         if (sk->sk_err != 0 || (sk->sk_shutdown & RCV_SHUTDOWN)
1763                             || (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1764                                 break;
1765                         }
1766                         /* Don't wait for non-blocking sockets. */
1767                         if (timeout == 0) {
1768                                 err = -EAGAIN;
1769                                 break;
1770                         }
1771 
1772                         err = transport->notify_recv_pre_block(
1773                                         vsk, target, &recv_data);
1774                         if (err < 0)
1775                                 break;
1776 
1777                         release_sock(sk);
1778                         timeout = schedule_timeout(timeout);
1779                         lock_sock(sk);
1780 
1781                         if (signal_pending(current)) {
1782                                 err = sock_intr_errno(timeout);
1783                                 break;
1784                         } else if (timeout == 0) {
1785                                 err = -EAGAIN;
1786                                 break;
1787                         }
1788 
1789                         prepare_to_wait(sk_sleep(sk), &wait,
1790                                         TASK_INTERRUPTIBLE);
1791                 }
1792         }
1793 
1794         if (sk->sk_err)
1795                 err = -sk->sk_err;
1796         else if (sk->sk_shutdown & RCV_SHUTDOWN)
1797                 err = 0;
1798 
1799         if (copied > 0) {
1800                 /* We only do these additional bookkeeping/notification steps
1801                  * if we actually copied something out of the queue pair
1802                  * instead of just peeking ahead.
1803                  */
1804 
1805                 if (!(flags & MSG_PEEK)) {
1806                         /* If the other side has shutdown for sending and there
1807                          * is nothing more to read, then modify the socket
1808                          * state.
1809                          */
1810                         if (vsk->peer_shutdown & SEND_SHUTDOWN) {
1811                                 if (vsock_stream_has_data(vsk) <= 0) {
1812                                         sk->sk_state = SS_UNCONNECTED;
1813                                         sock_set_flag(sk, SOCK_DONE);
1814                                         sk->sk_state_change(sk);
1815                                 }
1816                         }
1817                 }
1818                 err = copied;
1819         }
1820 
1821 out_wait:
1822         finish_wait(sk_sleep(sk), &wait);
1823 out:
1824         release_sock(sk);
1825         return err;
1826 }
1827 
1828 static const struct proto_ops vsock_stream_ops = {
1829         .family = PF_VSOCK,
1830         .owner = THIS_MODULE,
1831         .release = vsock_release,
1832         .bind = vsock_bind,
1833         .connect = vsock_stream_connect,
1834         .socketpair = sock_no_socketpair,
1835         .accept = vsock_accept,
1836         .getname = vsock_getname,
1837         .poll = vsock_poll,
1838         .ioctl = sock_no_ioctl,
1839         .listen = vsock_listen,
1840         .shutdown = vsock_shutdown,
1841         .setsockopt = vsock_stream_setsockopt,
1842         .getsockopt = vsock_stream_getsockopt,
1843         .sendmsg = vsock_stream_sendmsg,
1844         .recvmsg = vsock_stream_recvmsg,
1845         .mmap = sock_no_mmap,
1846         .sendpage = sock_no_sendpage,
1847 };
1848 
1849 static int vsock_create(struct net *net, struct socket *sock,
1850                         int protocol, int kern)
1851 {
1852         if (!sock)
1853                 return -EINVAL;
1854 
1855         if (protocol && protocol != PF_VSOCK)
1856                 return -EPROTONOSUPPORT;
1857 
1858         switch (sock->type) {
1859         case SOCK_DGRAM:
1860                 sock->ops = &vsock_dgram_ops;
1861                 break;
1862         case SOCK_STREAM:
1863                 sock->ops = &vsock_stream_ops;
1864                 break;
1865         default:
1866                 return -ESOCKTNOSUPPORT;
1867         }
1868 
1869         sock->state = SS_UNCONNECTED;
1870 
1871         return __vsock_create(net, sock, NULL, GFP_KERNEL, 0) ? 0 : -ENOMEM;
1872 }
1873 
1874 static const struct net_proto_family vsock_family_ops = {
1875         .family = AF_VSOCK,
1876         .create = vsock_create,
1877         .owner = THIS_MODULE,
1878 };
1879 
1880 static long vsock_dev_do_ioctl(struct file *filp,
1881                                unsigned int cmd, void __user *ptr)
1882 {
1883         u32 __user *p = ptr;
1884         int retval = 0;
1885 
1886         switch (cmd) {
1887         case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
1888                 if (put_user(transport->get_local_cid(), p) != 0)
1889                         retval = -EFAULT;
1890                 break;
1891 
1892         default:
1893                 pr_err("Unknown ioctl %d\n", cmd);
1894                 retval = -EINVAL;
1895         }
1896 
1897         return retval;
1898 }
1899 
1900 static long vsock_dev_ioctl(struct file *filp,
1901                             unsigned int cmd, unsigned long arg)
1902 {
1903         return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
1904 }
1905 
1906 #ifdef CONFIG_COMPAT
1907 static long vsock_dev_compat_ioctl(struct file *filp,
1908                                    unsigned int cmd, unsigned long arg)
1909 {
1910         return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
1911 }
1912 #endif
1913 
1914 static const struct file_operations vsock_device_ops = {
1915         .owner          = THIS_MODULE,
1916         .unlocked_ioctl = vsock_dev_ioctl,
1917 #ifdef CONFIG_COMPAT
1918         .compat_ioctl   = vsock_dev_compat_ioctl,
1919 #endif
1920         .open           = nonseekable_open,
1921 };
1922 
1923 static struct miscdevice vsock_device = {
1924         .name           = "vsock",
1925         .fops           = &vsock_device_ops,
1926 };
1927 
1928 int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
1929 {
1930         int err = mutex_lock_interruptible(&vsock_register_mutex);
1931 
1932         if (err)
1933                 return err;
1934 
1935         if (transport) {
1936                 err = -EBUSY;
1937                 goto err_busy;
1938         }
1939 
1940         /* Transport must be the owner of the protocol so that it can't
1941          * unload while there are open sockets.
1942          */
1943         vsock_proto.owner = owner;
1944         transport = t;
1945 
1946         vsock_init_tables();
1947 
1948         vsock_device.minor = MISC_DYNAMIC_MINOR;
1949         err = misc_register(&vsock_device);
1950         if (err) {
1951                 pr_err("Failed to register misc device\n");
1952                 return -ENOENT;
1953         }
1954 
1955         err = proto_register(&vsock_proto, 1);  /* we want our slab */
1956         if (err) {
1957                 pr_err("Cannot register vsock protocol\n");
1958                 goto err_misc_deregister;
1959         }
1960 
1961         err = sock_register(&vsock_family_ops);
1962         if (err) {
1963                 pr_err("could not register af_vsock (%d) address family: %d\n",
1964                        AF_VSOCK, err);
1965                 goto err_unregister_proto;
1966         }
1967 
1968         mutex_unlock(&vsock_register_mutex);
1969         return 0;
1970 
1971 err_unregister_proto:
1972         proto_unregister(&vsock_proto);
1973 err_misc_deregister:
1974         misc_deregister(&vsock_device);
1975         transport = NULL;
1976 err_busy:
1977         mutex_unlock(&vsock_register_mutex);
1978         return err;
1979 }
1980 EXPORT_SYMBOL_GPL(__vsock_core_init);
1981 
1982 void vsock_core_exit(void)
1983 {
1984         mutex_lock(&vsock_register_mutex);
1985 
1986         misc_deregister(&vsock_device);
1987         sock_unregister(AF_VSOCK);
1988         proto_unregister(&vsock_proto);
1989 
1990         /* We do not want the assignment below re-ordered. */
1991         mb();
1992         transport = NULL;
1993 
1994         mutex_unlock(&vsock_register_mutex);
1995 }
1996 EXPORT_SYMBOL_GPL(vsock_core_exit);
1997 
1998 MODULE_AUTHOR("VMware, Inc.");
1999 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2000 MODULE_VERSION("1.0.1.0-k");
2001 MODULE_LICENSE("GPL v2");
2002 

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