xref: /openbmc/linux/net/vmw_vsock/af_vsock.c (revision 7b73a9c8)
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 static DEFINE_MUTEX(vsock_register_mutex);
140 
141 /**** UTILS ****/
142 
143 /* Each bound VSocket is stored in the bind hash table and each connected
144  * VSocket is stored in the connected hash table.
145  *
146  * Unbound sockets are all put on the same list attached to the end of the hash
147  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
148  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
149  * represents the list that addr hashes to).
150  *
151  * Specifically, we initialize the vsock_bind_table array to a size of
152  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
153  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
154  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
155  * mods with VSOCK_HASH_SIZE to ensure this.
156  */
157 #define MAX_PORT_RETRIES        24
158 
159 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
160 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
161 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
162 
163 /* XXX This can probably be implemented in a better way. */
164 #define VSOCK_CONN_HASH(src, dst)				\
165 	(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
166 #define vsock_connected_sockets(src, dst)		\
167 	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
168 #define vsock_connected_sockets_vsk(vsk)				\
169 	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
170 
171 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
172 EXPORT_SYMBOL_GPL(vsock_bind_table);
173 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
174 EXPORT_SYMBOL_GPL(vsock_connected_table);
175 DEFINE_SPINLOCK(vsock_table_lock);
176 EXPORT_SYMBOL_GPL(vsock_table_lock);
177 
178 /* Autobind this socket to the local address if necessary. */
179 static int vsock_auto_bind(struct vsock_sock *vsk)
180 {
181 	struct sock *sk = sk_vsock(vsk);
182 	struct sockaddr_vm local_addr;
183 
184 	if (vsock_addr_bound(&vsk->local_addr))
185 		return 0;
186 	vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
187 	return __vsock_bind(sk, &local_addr);
188 }
189 
190 static void vsock_init_tables(void)
191 {
192 	int i;
193 
194 	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
195 		INIT_LIST_HEAD(&vsock_bind_table[i]);
196 
197 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
198 		INIT_LIST_HEAD(&vsock_connected_table[i]);
199 }
200 
201 static void __vsock_insert_bound(struct list_head *list,
202 				 struct vsock_sock *vsk)
203 {
204 	sock_hold(&vsk->sk);
205 	list_add(&vsk->bound_table, list);
206 }
207 
208 static void __vsock_insert_connected(struct list_head *list,
209 				     struct vsock_sock *vsk)
210 {
211 	sock_hold(&vsk->sk);
212 	list_add(&vsk->connected_table, list);
213 }
214 
215 static void __vsock_remove_bound(struct vsock_sock *vsk)
216 {
217 	list_del_init(&vsk->bound_table);
218 	sock_put(&vsk->sk);
219 }
220 
221 static void __vsock_remove_connected(struct vsock_sock *vsk)
222 {
223 	list_del_init(&vsk->connected_table);
224 	sock_put(&vsk->sk);
225 }
226 
227 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
228 {
229 	struct vsock_sock *vsk;
230 
231 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
232 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
233 			return sk_vsock(vsk);
234 
235 		if (addr->svm_port == vsk->local_addr.svm_port &&
236 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
237 		     addr->svm_cid == VMADDR_CID_ANY))
238 			return sk_vsock(vsk);
239 	}
240 
241 	return NULL;
242 }
243 
244 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
245 						  struct sockaddr_vm *dst)
246 {
247 	struct vsock_sock *vsk;
248 
249 	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
250 			    connected_table) {
251 		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
252 		    dst->svm_port == vsk->local_addr.svm_port) {
253 			return sk_vsock(vsk);
254 		}
255 	}
256 
257 	return NULL;
258 }
259 
260 static void vsock_insert_unbound(struct vsock_sock *vsk)
261 {
262 	spin_lock_bh(&vsock_table_lock);
263 	__vsock_insert_bound(vsock_unbound_sockets, vsk);
264 	spin_unlock_bh(&vsock_table_lock);
265 }
266 
267 void vsock_insert_connected(struct vsock_sock *vsk)
268 {
269 	struct list_head *list = vsock_connected_sockets(
270 		&vsk->remote_addr, &vsk->local_addr);
271 
272 	spin_lock_bh(&vsock_table_lock);
273 	__vsock_insert_connected(list, vsk);
274 	spin_unlock_bh(&vsock_table_lock);
275 }
276 EXPORT_SYMBOL_GPL(vsock_insert_connected);
277 
278 void vsock_remove_bound(struct vsock_sock *vsk)
279 {
280 	spin_lock_bh(&vsock_table_lock);
281 	if (__vsock_in_bound_table(vsk))
282 		__vsock_remove_bound(vsk);
283 	spin_unlock_bh(&vsock_table_lock);
284 }
285 EXPORT_SYMBOL_GPL(vsock_remove_bound);
286 
287 void vsock_remove_connected(struct vsock_sock *vsk)
288 {
289 	spin_lock_bh(&vsock_table_lock);
290 	if (__vsock_in_connected_table(vsk))
291 		__vsock_remove_connected(vsk);
292 	spin_unlock_bh(&vsock_table_lock);
293 }
294 EXPORT_SYMBOL_GPL(vsock_remove_connected);
295 
296 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
297 {
298 	struct sock *sk;
299 
300 	spin_lock_bh(&vsock_table_lock);
301 	sk = __vsock_find_bound_socket(addr);
302 	if (sk)
303 		sock_hold(sk);
304 
305 	spin_unlock_bh(&vsock_table_lock);
306 
307 	return sk;
308 }
309 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
310 
311 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
312 					 struct sockaddr_vm *dst)
313 {
314 	struct sock *sk;
315 
316 	spin_lock_bh(&vsock_table_lock);
317 	sk = __vsock_find_connected_socket(src, dst);
318 	if (sk)
319 		sock_hold(sk);
320 
321 	spin_unlock_bh(&vsock_table_lock);
322 
323 	return sk;
324 }
325 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
326 
327 void vsock_remove_sock(struct vsock_sock *vsk)
328 {
329 	vsock_remove_bound(vsk);
330 	vsock_remove_connected(vsk);
331 }
332 EXPORT_SYMBOL_GPL(vsock_remove_sock);
333 
334 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
335 {
336 	int i;
337 
338 	spin_lock_bh(&vsock_table_lock);
339 
340 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
341 		struct vsock_sock *vsk;
342 		list_for_each_entry(vsk, &vsock_connected_table[i],
343 				    connected_table)
344 			fn(sk_vsock(vsk));
345 	}
346 
347 	spin_unlock_bh(&vsock_table_lock);
348 }
349 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
350 
351 void vsock_add_pending(struct sock *listener, struct sock *pending)
352 {
353 	struct vsock_sock *vlistener;
354 	struct vsock_sock *vpending;
355 
356 	vlistener = vsock_sk(listener);
357 	vpending = vsock_sk(pending);
358 
359 	sock_hold(pending);
360 	sock_hold(listener);
361 	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
362 }
363 EXPORT_SYMBOL_GPL(vsock_add_pending);
364 
365 void vsock_remove_pending(struct sock *listener, struct sock *pending)
366 {
367 	struct vsock_sock *vpending = vsock_sk(pending);
368 
369 	list_del_init(&vpending->pending_links);
370 	sock_put(listener);
371 	sock_put(pending);
372 }
373 EXPORT_SYMBOL_GPL(vsock_remove_pending);
374 
375 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
376 {
377 	struct vsock_sock *vlistener;
378 	struct vsock_sock *vconnected;
379 
380 	vlistener = vsock_sk(listener);
381 	vconnected = vsock_sk(connected);
382 
383 	sock_hold(connected);
384 	sock_hold(listener);
385 	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
386 }
387 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
388 
389 static void vsock_deassign_transport(struct vsock_sock *vsk)
390 {
391 	if (!vsk->transport)
392 		return;
393 
394 	vsk->transport->destruct(vsk);
395 	module_put(vsk->transport->module);
396 	vsk->transport = NULL;
397 }
398 
399 /* Assign a transport to a socket and call the .init transport callback.
400  *
401  * Note: for stream socket this must be called when vsk->remote_addr is set
402  * (e.g. during the connect() or when a connection request on a listener
403  * socket is received).
404  * The vsk->remote_addr is used to decide which transport to use:
405  *  - remote CID <= VMADDR_CID_HOST will use guest->host transport;
406  *  - remote CID == local_cid (guest->host transport) will use guest->host
407  *    transport for loopback (host->guest transports don't support loopback);
408  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
409  */
410 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
411 {
412 	const struct vsock_transport *new_transport;
413 	struct sock *sk = sk_vsock(vsk);
414 	unsigned int remote_cid = vsk->remote_addr.svm_cid;
415 	int ret;
416 
417 	switch (sk->sk_type) {
418 	case SOCK_DGRAM:
419 		new_transport = transport_dgram;
420 		break;
421 	case SOCK_STREAM:
422 		if (remote_cid <= VMADDR_CID_HOST ||
423 		    (transport_g2h &&
424 		     remote_cid == transport_g2h->get_local_cid()))
425 			new_transport = transport_g2h;
426 		else
427 			new_transport = transport_h2g;
428 		break;
429 	default:
430 		return -ESOCKTNOSUPPORT;
431 	}
432 
433 	if (vsk->transport) {
434 		if (vsk->transport == new_transport)
435 			return 0;
436 
437 		vsk->transport->release(vsk);
438 		vsock_deassign_transport(vsk);
439 	}
440 
441 	/* We increase the module refcnt to prevent the transport unloading
442 	 * while there are open sockets assigned to it.
443 	 */
444 	if (!new_transport || !try_module_get(new_transport->module))
445 		return -ENODEV;
446 
447 	ret = new_transport->init(vsk, psk);
448 	if (ret) {
449 		module_put(new_transport->module);
450 		return ret;
451 	}
452 
453 	vsk->transport = new_transport;
454 
455 	return 0;
456 }
457 EXPORT_SYMBOL_GPL(vsock_assign_transport);
458 
459 bool vsock_find_cid(unsigned int cid)
460 {
461 	if (transport_g2h && cid == transport_g2h->get_local_cid())
462 		return true;
463 
464 	if (transport_h2g && cid == VMADDR_CID_HOST)
465 		return true;
466 
467 	return false;
468 }
469 EXPORT_SYMBOL_GPL(vsock_find_cid);
470 
471 static struct sock *vsock_dequeue_accept(struct sock *listener)
472 {
473 	struct vsock_sock *vlistener;
474 	struct vsock_sock *vconnected;
475 
476 	vlistener = vsock_sk(listener);
477 
478 	if (list_empty(&vlistener->accept_queue))
479 		return NULL;
480 
481 	vconnected = list_entry(vlistener->accept_queue.next,
482 				struct vsock_sock, accept_queue);
483 
484 	list_del_init(&vconnected->accept_queue);
485 	sock_put(listener);
486 	/* The caller will need a reference on the connected socket so we let
487 	 * it call sock_put().
488 	 */
489 
490 	return sk_vsock(vconnected);
491 }
492 
493 static bool vsock_is_accept_queue_empty(struct sock *sk)
494 {
495 	struct vsock_sock *vsk = vsock_sk(sk);
496 	return list_empty(&vsk->accept_queue);
497 }
498 
499 static bool vsock_is_pending(struct sock *sk)
500 {
501 	struct vsock_sock *vsk = vsock_sk(sk);
502 	return !list_empty(&vsk->pending_links);
503 }
504 
505 static int vsock_send_shutdown(struct sock *sk, int mode)
506 {
507 	struct vsock_sock *vsk = vsock_sk(sk);
508 
509 	if (!vsk->transport)
510 		return -ENODEV;
511 
512 	return vsk->transport->shutdown(vsk, mode);
513 }
514 
515 static void vsock_pending_work(struct work_struct *work)
516 {
517 	struct sock *sk;
518 	struct sock *listener;
519 	struct vsock_sock *vsk;
520 	bool cleanup;
521 
522 	vsk = container_of(work, struct vsock_sock, pending_work.work);
523 	sk = sk_vsock(vsk);
524 	listener = vsk->listener;
525 	cleanup = true;
526 
527 	lock_sock(listener);
528 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
529 
530 	if (vsock_is_pending(sk)) {
531 		vsock_remove_pending(listener, sk);
532 
533 		sk_acceptq_removed(listener);
534 	} else if (!vsk->rejected) {
535 		/* We are not on the pending list and accept() did not reject
536 		 * us, so we must have been accepted by our user process.  We
537 		 * just need to drop our references to the sockets and be on
538 		 * our way.
539 		 */
540 		cleanup = false;
541 		goto out;
542 	}
543 
544 	/* We need to remove ourself from the global connected sockets list so
545 	 * incoming packets can't find this socket, and to reduce the reference
546 	 * count.
547 	 */
548 	vsock_remove_connected(vsk);
549 
550 	sk->sk_state = TCP_CLOSE;
551 
552 out:
553 	release_sock(sk);
554 	release_sock(listener);
555 	if (cleanup)
556 		sock_put(sk);
557 
558 	sock_put(sk);
559 	sock_put(listener);
560 }
561 
562 /**** SOCKET OPERATIONS ****/
563 
564 static int __vsock_bind_stream(struct vsock_sock *vsk,
565 			       struct sockaddr_vm *addr)
566 {
567 	static u32 port;
568 	struct sockaddr_vm new_addr;
569 
570 	if (!port)
571 		port = LAST_RESERVED_PORT + 1 +
572 			prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
573 
574 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
575 
576 	if (addr->svm_port == VMADDR_PORT_ANY) {
577 		bool found = false;
578 		unsigned int i;
579 
580 		for (i = 0; i < MAX_PORT_RETRIES; i++) {
581 			if (port <= LAST_RESERVED_PORT)
582 				port = LAST_RESERVED_PORT + 1;
583 
584 			new_addr.svm_port = port++;
585 
586 			if (!__vsock_find_bound_socket(&new_addr)) {
587 				found = true;
588 				break;
589 			}
590 		}
591 
592 		if (!found)
593 			return -EADDRNOTAVAIL;
594 	} else {
595 		/* If port is in reserved range, ensure caller
596 		 * has necessary privileges.
597 		 */
598 		if (addr->svm_port <= LAST_RESERVED_PORT &&
599 		    !capable(CAP_NET_BIND_SERVICE)) {
600 			return -EACCES;
601 		}
602 
603 		if (__vsock_find_bound_socket(&new_addr))
604 			return -EADDRINUSE;
605 	}
606 
607 	vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
608 
609 	/* Remove stream sockets from the unbound list and add them to the hash
610 	 * table for easy lookup by its address.  The unbound list is simply an
611 	 * extra entry at the end of the hash table, a trick used by AF_UNIX.
612 	 */
613 	__vsock_remove_bound(vsk);
614 	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
615 
616 	return 0;
617 }
618 
619 static int __vsock_bind_dgram(struct vsock_sock *vsk,
620 			      struct sockaddr_vm *addr)
621 {
622 	return vsk->transport->dgram_bind(vsk, addr);
623 }
624 
625 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
626 {
627 	struct vsock_sock *vsk = vsock_sk(sk);
628 	int retval;
629 
630 	/* First ensure this socket isn't already bound. */
631 	if (vsock_addr_bound(&vsk->local_addr))
632 		return -EINVAL;
633 
634 	/* Now bind to the provided address or select appropriate values if
635 	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
636 	 * like AF_INET prevents binding to a non-local IP address (in most
637 	 * cases), we only allow binding to a local CID.
638 	 */
639 	if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
640 		return -EADDRNOTAVAIL;
641 
642 	switch (sk->sk_socket->type) {
643 	case SOCK_STREAM:
644 		spin_lock_bh(&vsock_table_lock);
645 		retval = __vsock_bind_stream(vsk, addr);
646 		spin_unlock_bh(&vsock_table_lock);
647 		break;
648 
649 	case SOCK_DGRAM:
650 		retval = __vsock_bind_dgram(vsk, addr);
651 		break;
652 
653 	default:
654 		retval = -EINVAL;
655 		break;
656 	}
657 
658 	return retval;
659 }
660 
661 static void vsock_connect_timeout(struct work_struct *work);
662 
663 static struct sock *__vsock_create(struct net *net,
664 				   struct socket *sock,
665 				   struct sock *parent,
666 				   gfp_t priority,
667 				   unsigned short type,
668 				   int kern)
669 {
670 	struct sock *sk;
671 	struct vsock_sock *psk;
672 	struct vsock_sock *vsk;
673 
674 	sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
675 	if (!sk)
676 		return NULL;
677 
678 	sock_init_data(sock, sk);
679 
680 	/* sk->sk_type is normally set in sock_init_data, but only if sock is
681 	 * non-NULL. We make sure that our sockets always have a type by
682 	 * setting it here if needed.
683 	 */
684 	if (!sock)
685 		sk->sk_type = type;
686 
687 	vsk = vsock_sk(sk);
688 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
689 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
690 
691 	sk->sk_destruct = vsock_sk_destruct;
692 	sk->sk_backlog_rcv = vsock_queue_rcv_skb;
693 	sock_reset_flag(sk, SOCK_DONE);
694 
695 	INIT_LIST_HEAD(&vsk->bound_table);
696 	INIT_LIST_HEAD(&vsk->connected_table);
697 	vsk->listener = NULL;
698 	INIT_LIST_HEAD(&vsk->pending_links);
699 	INIT_LIST_HEAD(&vsk->accept_queue);
700 	vsk->rejected = false;
701 	vsk->sent_request = false;
702 	vsk->ignore_connecting_rst = false;
703 	vsk->peer_shutdown = 0;
704 	INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
705 	INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
706 
707 	psk = parent ? vsock_sk(parent) : NULL;
708 	if (parent) {
709 		vsk->trusted = psk->trusted;
710 		vsk->owner = get_cred(psk->owner);
711 		vsk->connect_timeout = psk->connect_timeout;
712 		vsk->buffer_size = psk->buffer_size;
713 		vsk->buffer_min_size = psk->buffer_min_size;
714 		vsk->buffer_max_size = psk->buffer_max_size;
715 	} else {
716 		vsk->trusted = capable(CAP_NET_ADMIN);
717 		vsk->owner = get_current_cred();
718 		vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
719 		vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
720 		vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
721 		vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
722 	}
723 
724 	return sk;
725 }
726 
727 static void __vsock_release(struct sock *sk, int level)
728 {
729 	if (sk) {
730 		struct sock *pending;
731 		struct vsock_sock *vsk;
732 
733 		vsk = vsock_sk(sk);
734 		pending = NULL;	/* Compiler warning. */
735 
736 		/* The release call is supposed to use lock_sock_nested()
737 		 * rather than lock_sock(), if a sock lock should be acquired.
738 		 */
739 		if (vsk->transport)
740 			vsk->transport->release(vsk);
741 		else if (sk->sk_type == SOCK_STREAM)
742 			vsock_remove_sock(vsk);
743 
744 		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
745 		 * version to avoid the warning "possible recursive locking
746 		 * detected". When "level" is 0, lock_sock_nested(sk, level)
747 		 * is the same as lock_sock(sk).
748 		 */
749 		lock_sock_nested(sk, level);
750 		sock_orphan(sk);
751 		sk->sk_shutdown = SHUTDOWN_MASK;
752 
753 		skb_queue_purge(&sk->sk_receive_queue);
754 
755 		/* Clean up any sockets that never were accepted. */
756 		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
757 			__vsock_release(pending, SINGLE_DEPTH_NESTING);
758 			sock_put(pending);
759 		}
760 
761 		release_sock(sk);
762 		sock_put(sk);
763 	}
764 }
765 
766 static void vsock_sk_destruct(struct sock *sk)
767 {
768 	struct vsock_sock *vsk = vsock_sk(sk);
769 
770 	vsock_deassign_transport(vsk);
771 
772 	/* When clearing these addresses, there's no need to set the family and
773 	 * possibly register the address family with the kernel.
774 	 */
775 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
776 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
777 
778 	put_cred(vsk->owner);
779 }
780 
781 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
782 {
783 	int err;
784 
785 	err = sock_queue_rcv_skb(sk, skb);
786 	if (err)
787 		kfree_skb(skb);
788 
789 	return err;
790 }
791 
792 struct sock *vsock_create_connected(struct sock *parent)
793 {
794 	return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
795 			      parent->sk_type, 0);
796 }
797 EXPORT_SYMBOL_GPL(vsock_create_connected);
798 
799 s64 vsock_stream_has_data(struct vsock_sock *vsk)
800 {
801 	return vsk->transport->stream_has_data(vsk);
802 }
803 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
804 
805 s64 vsock_stream_has_space(struct vsock_sock *vsk)
806 {
807 	return vsk->transport->stream_has_space(vsk);
808 }
809 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
810 
811 static int vsock_release(struct socket *sock)
812 {
813 	__vsock_release(sock->sk, 0);
814 	sock->sk = NULL;
815 	sock->state = SS_FREE;
816 
817 	return 0;
818 }
819 
820 static int
821 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
822 {
823 	int err;
824 	struct sock *sk;
825 	struct sockaddr_vm *vm_addr;
826 
827 	sk = sock->sk;
828 
829 	if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
830 		return -EINVAL;
831 
832 	lock_sock(sk);
833 	err = __vsock_bind(sk, vm_addr);
834 	release_sock(sk);
835 
836 	return err;
837 }
838 
839 static int vsock_getname(struct socket *sock,
840 			 struct sockaddr *addr, int peer)
841 {
842 	int err;
843 	struct sock *sk;
844 	struct vsock_sock *vsk;
845 	struct sockaddr_vm *vm_addr;
846 
847 	sk = sock->sk;
848 	vsk = vsock_sk(sk);
849 	err = 0;
850 
851 	lock_sock(sk);
852 
853 	if (peer) {
854 		if (sock->state != SS_CONNECTED) {
855 			err = -ENOTCONN;
856 			goto out;
857 		}
858 		vm_addr = &vsk->remote_addr;
859 	} else {
860 		vm_addr = &vsk->local_addr;
861 	}
862 
863 	if (!vm_addr) {
864 		err = -EINVAL;
865 		goto out;
866 	}
867 
868 	/* sys_getsockname() and sys_getpeername() pass us a
869 	 * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
870 	 * that macro is defined in socket.c instead of .h, so we hardcode its
871 	 * value here.
872 	 */
873 	BUILD_BUG_ON(sizeof(*vm_addr) > 128);
874 	memcpy(addr, vm_addr, sizeof(*vm_addr));
875 	err = sizeof(*vm_addr);
876 
877 out:
878 	release_sock(sk);
879 	return err;
880 }
881 
882 static int vsock_shutdown(struct socket *sock, int mode)
883 {
884 	int err;
885 	struct sock *sk;
886 
887 	/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
888 	 * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
889 	 * here like the other address families do.  Note also that the
890 	 * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
891 	 * which is what we want.
892 	 */
893 	mode++;
894 
895 	if ((mode & ~SHUTDOWN_MASK) || !mode)
896 		return -EINVAL;
897 
898 	/* If this is a STREAM socket and it is not connected then bail out
899 	 * immediately.  If it is a DGRAM socket then we must first kick the
900 	 * socket so that it wakes up from any sleeping calls, for example
901 	 * recv(), and then afterwards return the error.
902 	 */
903 
904 	sk = sock->sk;
905 	if (sock->state == SS_UNCONNECTED) {
906 		err = -ENOTCONN;
907 		if (sk->sk_type == SOCK_STREAM)
908 			return err;
909 	} else {
910 		sock->state = SS_DISCONNECTING;
911 		err = 0;
912 	}
913 
914 	/* Receive and send shutdowns are treated alike. */
915 	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
916 	if (mode) {
917 		lock_sock(sk);
918 		sk->sk_shutdown |= mode;
919 		sk->sk_state_change(sk);
920 		release_sock(sk);
921 
922 		if (sk->sk_type == SOCK_STREAM) {
923 			sock_reset_flag(sk, SOCK_DONE);
924 			vsock_send_shutdown(sk, mode);
925 		}
926 	}
927 
928 	return err;
929 }
930 
931 static __poll_t vsock_poll(struct file *file, struct socket *sock,
932 			       poll_table *wait)
933 {
934 	struct sock *sk;
935 	__poll_t mask;
936 	struct vsock_sock *vsk;
937 
938 	sk = sock->sk;
939 	vsk = vsock_sk(sk);
940 
941 	poll_wait(file, sk_sleep(sk), wait);
942 	mask = 0;
943 
944 	if (sk->sk_err)
945 		/* Signify that there has been an error on this socket. */
946 		mask |= EPOLLERR;
947 
948 	/* INET sockets treat local write shutdown and peer write shutdown as a
949 	 * case of EPOLLHUP set.
950 	 */
951 	if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
952 	    ((sk->sk_shutdown & SEND_SHUTDOWN) &&
953 	     (vsk->peer_shutdown & SEND_SHUTDOWN))) {
954 		mask |= EPOLLHUP;
955 	}
956 
957 	if (sk->sk_shutdown & RCV_SHUTDOWN ||
958 	    vsk->peer_shutdown & SEND_SHUTDOWN) {
959 		mask |= EPOLLRDHUP;
960 	}
961 
962 	if (sock->type == SOCK_DGRAM) {
963 		/* For datagram sockets we can read if there is something in
964 		 * the queue and write as long as the socket isn't shutdown for
965 		 * sending.
966 		 */
967 		if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
968 		    (sk->sk_shutdown & RCV_SHUTDOWN)) {
969 			mask |= EPOLLIN | EPOLLRDNORM;
970 		}
971 
972 		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
973 			mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
974 
975 	} else if (sock->type == SOCK_STREAM) {
976 		const struct vsock_transport *transport = vsk->transport;
977 		lock_sock(sk);
978 
979 		/* Listening sockets that have connections in their accept
980 		 * queue can be read.
981 		 */
982 		if (sk->sk_state == TCP_LISTEN
983 		    && !vsock_is_accept_queue_empty(sk))
984 			mask |= EPOLLIN | EPOLLRDNORM;
985 
986 		/* If there is something in the queue then we can read. */
987 		if (transport && transport->stream_is_active(vsk) &&
988 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
989 			bool data_ready_now = false;
990 			int ret = transport->notify_poll_in(
991 					vsk, 1, &data_ready_now);
992 			if (ret < 0) {
993 				mask |= EPOLLERR;
994 			} else {
995 				if (data_ready_now)
996 					mask |= EPOLLIN | EPOLLRDNORM;
997 
998 			}
999 		}
1000 
1001 		/* Sockets whose connections have been closed, reset, or
1002 		 * terminated should also be considered read, and we check the
1003 		 * shutdown flag for that.
1004 		 */
1005 		if (sk->sk_shutdown & RCV_SHUTDOWN ||
1006 		    vsk->peer_shutdown & SEND_SHUTDOWN) {
1007 			mask |= EPOLLIN | EPOLLRDNORM;
1008 		}
1009 
1010 		/* Connected sockets that can produce data can be written. */
1011 		if (sk->sk_state == TCP_ESTABLISHED) {
1012 			if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1013 				bool space_avail_now = false;
1014 				int ret = transport->notify_poll_out(
1015 						vsk, 1, &space_avail_now);
1016 				if (ret < 0) {
1017 					mask |= EPOLLERR;
1018 				} else {
1019 					if (space_avail_now)
1020 						/* Remove EPOLLWRBAND since INET
1021 						 * sockets are not setting it.
1022 						 */
1023 						mask |= EPOLLOUT | EPOLLWRNORM;
1024 
1025 				}
1026 			}
1027 		}
1028 
1029 		/* Simulate INET socket poll behaviors, which sets
1030 		 * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1031 		 * but local send is not shutdown.
1032 		 */
1033 		if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1034 			if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1035 				mask |= EPOLLOUT | EPOLLWRNORM;
1036 
1037 		}
1038 
1039 		release_sock(sk);
1040 	}
1041 
1042 	return mask;
1043 }
1044 
1045 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1046 			       size_t len)
1047 {
1048 	int err;
1049 	struct sock *sk;
1050 	struct vsock_sock *vsk;
1051 	struct sockaddr_vm *remote_addr;
1052 	const struct vsock_transport *transport;
1053 
1054 	if (msg->msg_flags & MSG_OOB)
1055 		return -EOPNOTSUPP;
1056 
1057 	/* For now, MSG_DONTWAIT is always assumed... */
1058 	err = 0;
1059 	sk = sock->sk;
1060 	vsk = vsock_sk(sk);
1061 	transport = vsk->transport;
1062 
1063 	lock_sock(sk);
1064 
1065 	err = vsock_auto_bind(vsk);
1066 	if (err)
1067 		goto out;
1068 
1069 
1070 	/* If the provided message contains an address, use that.  Otherwise
1071 	 * fall back on the socket's remote handle (if it has been connected).
1072 	 */
1073 	if (msg->msg_name &&
1074 	    vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1075 			    &remote_addr) == 0) {
1076 		/* Ensure this address is of the right type and is a valid
1077 		 * destination.
1078 		 */
1079 
1080 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1081 			remote_addr->svm_cid = transport->get_local_cid();
1082 
1083 		if (!vsock_addr_bound(remote_addr)) {
1084 			err = -EINVAL;
1085 			goto out;
1086 		}
1087 	} else if (sock->state == SS_CONNECTED) {
1088 		remote_addr = &vsk->remote_addr;
1089 
1090 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1091 			remote_addr->svm_cid = transport->get_local_cid();
1092 
1093 		/* XXX Should connect() or this function ensure remote_addr is
1094 		 * bound?
1095 		 */
1096 		if (!vsock_addr_bound(&vsk->remote_addr)) {
1097 			err = -EINVAL;
1098 			goto out;
1099 		}
1100 	} else {
1101 		err = -EINVAL;
1102 		goto out;
1103 	}
1104 
1105 	if (!transport->dgram_allow(remote_addr->svm_cid,
1106 				    remote_addr->svm_port)) {
1107 		err = -EINVAL;
1108 		goto out;
1109 	}
1110 
1111 	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1112 
1113 out:
1114 	release_sock(sk);
1115 	return err;
1116 }
1117 
1118 static int vsock_dgram_connect(struct socket *sock,
1119 			       struct sockaddr *addr, int addr_len, int flags)
1120 {
1121 	int err;
1122 	struct sock *sk;
1123 	struct vsock_sock *vsk;
1124 	struct sockaddr_vm *remote_addr;
1125 
1126 	sk = sock->sk;
1127 	vsk = vsock_sk(sk);
1128 
1129 	err = vsock_addr_cast(addr, addr_len, &remote_addr);
1130 	if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1131 		lock_sock(sk);
1132 		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1133 				VMADDR_PORT_ANY);
1134 		sock->state = SS_UNCONNECTED;
1135 		release_sock(sk);
1136 		return 0;
1137 	} else if (err != 0)
1138 		return -EINVAL;
1139 
1140 	lock_sock(sk);
1141 
1142 	err = vsock_auto_bind(vsk);
1143 	if (err)
1144 		goto out;
1145 
1146 	if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1147 					 remote_addr->svm_port)) {
1148 		err = -EINVAL;
1149 		goto out;
1150 	}
1151 
1152 	memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1153 	sock->state = SS_CONNECTED;
1154 
1155 out:
1156 	release_sock(sk);
1157 	return err;
1158 }
1159 
1160 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1161 			       size_t len, int flags)
1162 {
1163 	struct vsock_sock *vsk = vsock_sk(sock->sk);
1164 
1165 	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1166 }
1167 
1168 static const struct proto_ops vsock_dgram_ops = {
1169 	.family = PF_VSOCK,
1170 	.owner = THIS_MODULE,
1171 	.release = vsock_release,
1172 	.bind = vsock_bind,
1173 	.connect = vsock_dgram_connect,
1174 	.socketpair = sock_no_socketpair,
1175 	.accept = sock_no_accept,
1176 	.getname = vsock_getname,
1177 	.poll = vsock_poll,
1178 	.ioctl = sock_no_ioctl,
1179 	.listen = sock_no_listen,
1180 	.shutdown = vsock_shutdown,
1181 	.setsockopt = sock_no_setsockopt,
1182 	.getsockopt = sock_no_getsockopt,
1183 	.sendmsg = vsock_dgram_sendmsg,
1184 	.recvmsg = vsock_dgram_recvmsg,
1185 	.mmap = sock_no_mmap,
1186 	.sendpage = sock_no_sendpage,
1187 };
1188 
1189 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1190 {
1191 	const struct vsock_transport *transport = vsk->transport;
1192 
1193 	if (!transport->cancel_pkt)
1194 		return -EOPNOTSUPP;
1195 
1196 	return transport->cancel_pkt(vsk);
1197 }
1198 
1199 static void vsock_connect_timeout(struct work_struct *work)
1200 {
1201 	struct sock *sk;
1202 	struct vsock_sock *vsk;
1203 	int cancel = 0;
1204 
1205 	vsk = container_of(work, struct vsock_sock, connect_work.work);
1206 	sk = sk_vsock(vsk);
1207 
1208 	lock_sock(sk);
1209 	if (sk->sk_state == TCP_SYN_SENT &&
1210 	    (sk->sk_shutdown != SHUTDOWN_MASK)) {
1211 		sk->sk_state = TCP_CLOSE;
1212 		sk->sk_err = ETIMEDOUT;
1213 		sk->sk_error_report(sk);
1214 		cancel = 1;
1215 	}
1216 	release_sock(sk);
1217 	if (cancel)
1218 		vsock_transport_cancel_pkt(vsk);
1219 
1220 	sock_put(sk);
1221 }
1222 
1223 static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
1224 				int addr_len, int flags)
1225 {
1226 	int err;
1227 	struct sock *sk;
1228 	struct vsock_sock *vsk;
1229 	const struct vsock_transport *transport;
1230 	struct sockaddr_vm *remote_addr;
1231 	long timeout;
1232 	DEFINE_WAIT(wait);
1233 
1234 	err = 0;
1235 	sk = sock->sk;
1236 	vsk = vsock_sk(sk);
1237 
1238 	lock_sock(sk);
1239 
1240 	/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1241 	switch (sock->state) {
1242 	case SS_CONNECTED:
1243 		err = -EISCONN;
1244 		goto out;
1245 	case SS_DISCONNECTING:
1246 		err = -EINVAL;
1247 		goto out;
1248 	case SS_CONNECTING:
1249 		/* This continues on so we can move sock into the SS_CONNECTED
1250 		 * state once the connection has completed (at which point err
1251 		 * will be set to zero also).  Otherwise, we will either wait
1252 		 * for the connection or return -EALREADY should this be a
1253 		 * non-blocking call.
1254 		 */
1255 		err = -EALREADY;
1256 		break;
1257 	default:
1258 		if ((sk->sk_state == TCP_LISTEN) ||
1259 		    vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1260 			err = -EINVAL;
1261 			goto out;
1262 		}
1263 
1264 		/* Set the remote address that we are connecting to. */
1265 		memcpy(&vsk->remote_addr, remote_addr,
1266 		       sizeof(vsk->remote_addr));
1267 
1268 		err = vsock_assign_transport(vsk, NULL);
1269 		if (err)
1270 			goto out;
1271 
1272 		transport = vsk->transport;
1273 
1274 		/* The hypervisor and well-known contexts do not have socket
1275 		 * endpoints.
1276 		 */
1277 		if (!transport ||
1278 		    !transport->stream_allow(remote_addr->svm_cid,
1279 					     remote_addr->svm_port)) {
1280 			err = -ENETUNREACH;
1281 			goto out;
1282 		}
1283 
1284 		err = vsock_auto_bind(vsk);
1285 		if (err)
1286 			goto out;
1287 
1288 		sk->sk_state = TCP_SYN_SENT;
1289 
1290 		err = transport->connect(vsk);
1291 		if (err < 0)
1292 			goto out;
1293 
1294 		/* Mark sock as connecting and set the error code to in
1295 		 * progress in case this is a non-blocking connect.
1296 		 */
1297 		sock->state = SS_CONNECTING;
1298 		err = -EINPROGRESS;
1299 	}
1300 
1301 	/* The receive path will handle all communication until we are able to
1302 	 * enter the connected state.  Here we wait for the connection to be
1303 	 * completed or a notification of an error.
1304 	 */
1305 	timeout = vsk->connect_timeout;
1306 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1307 
1308 	while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1309 		if (flags & O_NONBLOCK) {
1310 			/* If we're not going to block, we schedule a timeout
1311 			 * function to generate a timeout on the connection
1312 			 * attempt, in case the peer doesn't respond in a
1313 			 * timely manner. We hold on to the socket until the
1314 			 * timeout fires.
1315 			 */
1316 			sock_hold(sk);
1317 			schedule_delayed_work(&vsk->connect_work, timeout);
1318 
1319 			/* Skip ahead to preserve error code set above. */
1320 			goto out_wait;
1321 		}
1322 
1323 		release_sock(sk);
1324 		timeout = schedule_timeout(timeout);
1325 		lock_sock(sk);
1326 
1327 		if (signal_pending(current)) {
1328 			err = sock_intr_errno(timeout);
1329 			sk->sk_state = TCP_CLOSE;
1330 			sock->state = SS_UNCONNECTED;
1331 			vsock_transport_cancel_pkt(vsk);
1332 			goto out_wait;
1333 		} else if (timeout == 0) {
1334 			err = -ETIMEDOUT;
1335 			sk->sk_state = TCP_CLOSE;
1336 			sock->state = SS_UNCONNECTED;
1337 			vsock_transport_cancel_pkt(vsk);
1338 			goto out_wait;
1339 		}
1340 
1341 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1342 	}
1343 
1344 	if (sk->sk_err) {
1345 		err = -sk->sk_err;
1346 		sk->sk_state = TCP_CLOSE;
1347 		sock->state = SS_UNCONNECTED;
1348 	} else {
1349 		err = 0;
1350 	}
1351 
1352 out_wait:
1353 	finish_wait(sk_sleep(sk), &wait);
1354 out:
1355 	release_sock(sk);
1356 	return err;
1357 }
1358 
1359 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1360 			bool kern)
1361 {
1362 	struct sock *listener;
1363 	int err;
1364 	struct sock *connected;
1365 	struct vsock_sock *vconnected;
1366 	long timeout;
1367 	DEFINE_WAIT(wait);
1368 
1369 	err = 0;
1370 	listener = sock->sk;
1371 
1372 	lock_sock(listener);
1373 
1374 	if (sock->type != SOCK_STREAM) {
1375 		err = -EOPNOTSUPP;
1376 		goto out;
1377 	}
1378 
1379 	if (listener->sk_state != TCP_LISTEN) {
1380 		err = -EINVAL;
1381 		goto out;
1382 	}
1383 
1384 	/* Wait for children sockets to appear; these are the new sockets
1385 	 * created upon connection establishment.
1386 	 */
1387 	timeout = sock_sndtimeo(listener, flags & O_NONBLOCK);
1388 	prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1389 
1390 	while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1391 	       listener->sk_err == 0) {
1392 		release_sock(listener);
1393 		timeout = schedule_timeout(timeout);
1394 		finish_wait(sk_sleep(listener), &wait);
1395 		lock_sock(listener);
1396 
1397 		if (signal_pending(current)) {
1398 			err = sock_intr_errno(timeout);
1399 			goto out;
1400 		} else if (timeout == 0) {
1401 			err = -EAGAIN;
1402 			goto out;
1403 		}
1404 
1405 		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1406 	}
1407 	finish_wait(sk_sleep(listener), &wait);
1408 
1409 	if (listener->sk_err)
1410 		err = -listener->sk_err;
1411 
1412 	if (connected) {
1413 		sk_acceptq_removed(listener);
1414 
1415 		lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1416 		vconnected = vsock_sk(connected);
1417 
1418 		/* If the listener socket has received an error, then we should
1419 		 * reject this socket and return.  Note that we simply mark the
1420 		 * socket rejected, drop our reference, and let the cleanup
1421 		 * function handle the cleanup; the fact that we found it in
1422 		 * the listener's accept queue guarantees that the cleanup
1423 		 * function hasn't run yet.
1424 		 */
1425 		if (err) {
1426 			vconnected->rejected = true;
1427 		} else {
1428 			newsock->state = SS_CONNECTED;
1429 			sock_graft(connected, newsock);
1430 		}
1431 
1432 		release_sock(connected);
1433 		sock_put(connected);
1434 	}
1435 
1436 out:
1437 	release_sock(listener);
1438 	return err;
1439 }
1440 
1441 static int vsock_listen(struct socket *sock, int backlog)
1442 {
1443 	int err;
1444 	struct sock *sk;
1445 	struct vsock_sock *vsk;
1446 
1447 	sk = sock->sk;
1448 
1449 	lock_sock(sk);
1450 
1451 	if (sock->type != SOCK_STREAM) {
1452 		err = -EOPNOTSUPP;
1453 		goto out;
1454 	}
1455 
1456 	if (sock->state != SS_UNCONNECTED) {
1457 		err = -EINVAL;
1458 		goto out;
1459 	}
1460 
1461 	vsk = vsock_sk(sk);
1462 
1463 	if (!vsock_addr_bound(&vsk->local_addr)) {
1464 		err = -EINVAL;
1465 		goto out;
1466 	}
1467 
1468 	sk->sk_max_ack_backlog = backlog;
1469 	sk->sk_state = TCP_LISTEN;
1470 
1471 	err = 0;
1472 
1473 out:
1474 	release_sock(sk);
1475 	return err;
1476 }
1477 
1478 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1479 				     const struct vsock_transport *transport,
1480 				     u64 val)
1481 {
1482 	if (val > vsk->buffer_max_size)
1483 		val = vsk->buffer_max_size;
1484 
1485 	if (val < vsk->buffer_min_size)
1486 		val = vsk->buffer_min_size;
1487 
1488 	if (val != vsk->buffer_size &&
1489 	    transport && transport->notify_buffer_size)
1490 		transport->notify_buffer_size(vsk, &val);
1491 
1492 	vsk->buffer_size = val;
1493 }
1494 
1495 static int vsock_stream_setsockopt(struct socket *sock,
1496 				   int level,
1497 				   int optname,
1498 				   char __user *optval,
1499 				   unsigned int optlen)
1500 {
1501 	int err;
1502 	struct sock *sk;
1503 	struct vsock_sock *vsk;
1504 	const struct vsock_transport *transport;
1505 	u64 val;
1506 
1507 	if (level != AF_VSOCK)
1508 		return -ENOPROTOOPT;
1509 
1510 #define COPY_IN(_v)                                       \
1511 	do {						  \
1512 		if (optlen < sizeof(_v)) {		  \
1513 			err = -EINVAL;			  \
1514 			goto exit;			  \
1515 		}					  \
1516 		if (copy_from_user(&_v, optval, sizeof(_v)) != 0) {	\
1517 			err = -EFAULT;					\
1518 			goto exit;					\
1519 		}							\
1520 	} while (0)
1521 
1522 	err = 0;
1523 	sk = sock->sk;
1524 	vsk = vsock_sk(sk);
1525 	transport = vsk->transport;
1526 
1527 	lock_sock(sk);
1528 
1529 	switch (optname) {
1530 	case SO_VM_SOCKETS_BUFFER_SIZE:
1531 		COPY_IN(val);
1532 		vsock_update_buffer_size(vsk, transport, val);
1533 		break;
1534 
1535 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1536 		COPY_IN(val);
1537 		vsk->buffer_max_size = val;
1538 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1539 		break;
1540 
1541 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1542 		COPY_IN(val);
1543 		vsk->buffer_min_size = val;
1544 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1545 		break;
1546 
1547 	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1548 		struct __kernel_old_timeval tv;
1549 		COPY_IN(tv);
1550 		if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1551 		    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1552 			vsk->connect_timeout = tv.tv_sec * HZ +
1553 			    DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1554 			if (vsk->connect_timeout == 0)
1555 				vsk->connect_timeout =
1556 				    VSOCK_DEFAULT_CONNECT_TIMEOUT;
1557 
1558 		} else {
1559 			err = -ERANGE;
1560 		}
1561 		break;
1562 	}
1563 
1564 	default:
1565 		err = -ENOPROTOOPT;
1566 		break;
1567 	}
1568 
1569 #undef COPY_IN
1570 
1571 exit:
1572 	release_sock(sk);
1573 	return err;
1574 }
1575 
1576 static int vsock_stream_getsockopt(struct socket *sock,
1577 				   int level, int optname,
1578 				   char __user *optval,
1579 				   int __user *optlen)
1580 {
1581 	int err;
1582 	int len;
1583 	struct sock *sk;
1584 	struct vsock_sock *vsk;
1585 	u64 val;
1586 
1587 	if (level != AF_VSOCK)
1588 		return -ENOPROTOOPT;
1589 
1590 	err = get_user(len, optlen);
1591 	if (err != 0)
1592 		return err;
1593 
1594 #define COPY_OUT(_v)                            \
1595 	do {					\
1596 		if (len < sizeof(_v))		\
1597 			return -EINVAL;		\
1598 						\
1599 		len = sizeof(_v);		\
1600 		if (copy_to_user(optval, &_v, len) != 0)	\
1601 			return -EFAULT;				\
1602 								\
1603 	} while (0)
1604 
1605 	err = 0;
1606 	sk = sock->sk;
1607 	vsk = vsock_sk(sk);
1608 
1609 	switch (optname) {
1610 	case SO_VM_SOCKETS_BUFFER_SIZE:
1611 		val = vsk->buffer_size;
1612 		COPY_OUT(val);
1613 		break;
1614 
1615 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1616 		val = vsk->buffer_max_size;
1617 		COPY_OUT(val);
1618 		break;
1619 
1620 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1621 		val = vsk->buffer_min_size;
1622 		COPY_OUT(val);
1623 		break;
1624 
1625 	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1626 		struct __kernel_old_timeval tv;
1627 		tv.tv_sec = vsk->connect_timeout / HZ;
1628 		tv.tv_usec =
1629 		    (vsk->connect_timeout -
1630 		     tv.tv_sec * HZ) * (1000000 / HZ);
1631 		COPY_OUT(tv);
1632 		break;
1633 	}
1634 	default:
1635 		return -ENOPROTOOPT;
1636 	}
1637 
1638 	err = put_user(len, optlen);
1639 	if (err != 0)
1640 		return -EFAULT;
1641 
1642 #undef COPY_OUT
1643 
1644 	return 0;
1645 }
1646 
1647 static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1648 				size_t len)
1649 {
1650 	struct sock *sk;
1651 	struct vsock_sock *vsk;
1652 	const struct vsock_transport *transport;
1653 	ssize_t total_written;
1654 	long timeout;
1655 	int err;
1656 	struct vsock_transport_send_notify_data send_data;
1657 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1658 
1659 	sk = sock->sk;
1660 	vsk = vsock_sk(sk);
1661 	transport = vsk->transport;
1662 	total_written = 0;
1663 	err = 0;
1664 
1665 	if (msg->msg_flags & MSG_OOB)
1666 		return -EOPNOTSUPP;
1667 
1668 	lock_sock(sk);
1669 
1670 	/* Callers should not provide a destination with stream sockets. */
1671 	if (msg->msg_namelen) {
1672 		err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1673 		goto out;
1674 	}
1675 
1676 	/* Send data only if both sides are not shutdown in the direction. */
1677 	if (sk->sk_shutdown & SEND_SHUTDOWN ||
1678 	    vsk->peer_shutdown & RCV_SHUTDOWN) {
1679 		err = -EPIPE;
1680 		goto out;
1681 	}
1682 
1683 	if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1684 	    !vsock_addr_bound(&vsk->local_addr)) {
1685 		err = -ENOTCONN;
1686 		goto out;
1687 	}
1688 
1689 	if (!vsock_addr_bound(&vsk->remote_addr)) {
1690 		err = -EDESTADDRREQ;
1691 		goto out;
1692 	}
1693 
1694 	/* Wait for room in the produce queue to enqueue our user's data. */
1695 	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1696 
1697 	err = transport->notify_send_init(vsk, &send_data);
1698 	if (err < 0)
1699 		goto out;
1700 
1701 	while (total_written < len) {
1702 		ssize_t written;
1703 
1704 		add_wait_queue(sk_sleep(sk), &wait);
1705 		while (vsock_stream_has_space(vsk) == 0 &&
1706 		       sk->sk_err == 0 &&
1707 		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1708 		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1709 
1710 			/* Don't wait for non-blocking sockets. */
1711 			if (timeout == 0) {
1712 				err = -EAGAIN;
1713 				remove_wait_queue(sk_sleep(sk), &wait);
1714 				goto out_err;
1715 			}
1716 
1717 			err = transport->notify_send_pre_block(vsk, &send_data);
1718 			if (err < 0) {
1719 				remove_wait_queue(sk_sleep(sk), &wait);
1720 				goto out_err;
1721 			}
1722 
1723 			release_sock(sk);
1724 			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1725 			lock_sock(sk);
1726 			if (signal_pending(current)) {
1727 				err = sock_intr_errno(timeout);
1728 				remove_wait_queue(sk_sleep(sk), &wait);
1729 				goto out_err;
1730 			} else if (timeout == 0) {
1731 				err = -EAGAIN;
1732 				remove_wait_queue(sk_sleep(sk), &wait);
1733 				goto out_err;
1734 			}
1735 		}
1736 		remove_wait_queue(sk_sleep(sk), &wait);
1737 
1738 		/* These checks occur both as part of and after the loop
1739 		 * conditional since we need to check before and after
1740 		 * sleeping.
1741 		 */
1742 		if (sk->sk_err) {
1743 			err = -sk->sk_err;
1744 			goto out_err;
1745 		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1746 			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1747 			err = -EPIPE;
1748 			goto out_err;
1749 		}
1750 
1751 		err = transport->notify_send_pre_enqueue(vsk, &send_data);
1752 		if (err < 0)
1753 			goto out_err;
1754 
1755 		/* Note that enqueue will only write as many bytes as are free
1756 		 * in the produce queue, so we don't need to ensure len is
1757 		 * smaller than the queue size.  It is the caller's
1758 		 * responsibility to check how many bytes we were able to send.
1759 		 */
1760 
1761 		written = transport->stream_enqueue(
1762 				vsk, msg,
1763 				len - total_written);
1764 		if (written < 0) {
1765 			err = -ENOMEM;
1766 			goto out_err;
1767 		}
1768 
1769 		total_written += written;
1770 
1771 		err = transport->notify_send_post_enqueue(
1772 				vsk, written, &send_data);
1773 		if (err < 0)
1774 			goto out_err;
1775 
1776 	}
1777 
1778 out_err:
1779 	if (total_written > 0)
1780 		err = total_written;
1781 out:
1782 	release_sock(sk);
1783 	return err;
1784 }
1785 
1786 
1787 static int
1788 vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1789 		     int flags)
1790 {
1791 	struct sock *sk;
1792 	struct vsock_sock *vsk;
1793 	const struct vsock_transport *transport;
1794 	int err;
1795 	size_t target;
1796 	ssize_t copied;
1797 	long timeout;
1798 	struct vsock_transport_recv_notify_data recv_data;
1799 
1800 	DEFINE_WAIT(wait);
1801 
1802 	sk = sock->sk;
1803 	vsk = vsock_sk(sk);
1804 	transport = vsk->transport;
1805 	err = 0;
1806 
1807 	lock_sock(sk);
1808 
1809 	if (!transport || sk->sk_state != TCP_ESTABLISHED) {
1810 		/* Recvmsg is supposed to return 0 if a peer performs an
1811 		 * orderly shutdown. Differentiate between that case and when a
1812 		 * peer has not connected or a local shutdown occured with the
1813 		 * SOCK_DONE flag.
1814 		 */
1815 		if (sock_flag(sk, SOCK_DONE))
1816 			err = 0;
1817 		else
1818 			err = -ENOTCONN;
1819 
1820 		goto out;
1821 	}
1822 
1823 	if (flags & MSG_OOB) {
1824 		err = -EOPNOTSUPP;
1825 		goto out;
1826 	}
1827 
1828 	/* We don't check peer_shutdown flag here since peer may actually shut
1829 	 * down, but there can be data in the queue that a local socket can
1830 	 * receive.
1831 	 */
1832 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1833 		err = 0;
1834 		goto out;
1835 	}
1836 
1837 	/* It is valid on Linux to pass in a zero-length receive buffer.  This
1838 	 * is not an error.  We may as well bail out now.
1839 	 */
1840 	if (!len) {
1841 		err = 0;
1842 		goto out;
1843 	}
1844 
1845 	/* We must not copy less than target bytes into the user's buffer
1846 	 * before returning successfully, so we wait for the consume queue to
1847 	 * have that much data to consume before dequeueing.  Note that this
1848 	 * makes it impossible to handle cases where target is greater than the
1849 	 * queue size.
1850 	 */
1851 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1852 	if (target >= transport->stream_rcvhiwat(vsk)) {
1853 		err = -ENOMEM;
1854 		goto out;
1855 	}
1856 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1857 	copied = 0;
1858 
1859 	err = transport->notify_recv_init(vsk, target, &recv_data);
1860 	if (err < 0)
1861 		goto out;
1862 
1863 
1864 	while (1) {
1865 		s64 ready;
1866 
1867 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1868 		ready = vsock_stream_has_data(vsk);
1869 
1870 		if (ready == 0) {
1871 			if (sk->sk_err != 0 ||
1872 			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
1873 			    (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1874 				finish_wait(sk_sleep(sk), &wait);
1875 				break;
1876 			}
1877 			/* Don't wait for non-blocking sockets. */
1878 			if (timeout == 0) {
1879 				err = -EAGAIN;
1880 				finish_wait(sk_sleep(sk), &wait);
1881 				break;
1882 			}
1883 
1884 			err = transport->notify_recv_pre_block(
1885 					vsk, target, &recv_data);
1886 			if (err < 0) {
1887 				finish_wait(sk_sleep(sk), &wait);
1888 				break;
1889 			}
1890 			release_sock(sk);
1891 			timeout = schedule_timeout(timeout);
1892 			lock_sock(sk);
1893 
1894 			if (signal_pending(current)) {
1895 				err = sock_intr_errno(timeout);
1896 				finish_wait(sk_sleep(sk), &wait);
1897 				break;
1898 			} else if (timeout == 0) {
1899 				err = -EAGAIN;
1900 				finish_wait(sk_sleep(sk), &wait);
1901 				break;
1902 			}
1903 		} else {
1904 			ssize_t read;
1905 
1906 			finish_wait(sk_sleep(sk), &wait);
1907 
1908 			if (ready < 0) {
1909 				/* Invalid queue pair content. XXX This should
1910 				* be changed to a connection reset in a later
1911 				* change.
1912 				*/
1913 
1914 				err = -ENOMEM;
1915 				goto out;
1916 			}
1917 
1918 			err = transport->notify_recv_pre_dequeue(
1919 					vsk, target, &recv_data);
1920 			if (err < 0)
1921 				break;
1922 
1923 			read = transport->stream_dequeue(
1924 					vsk, msg,
1925 					len - copied, flags);
1926 			if (read < 0) {
1927 				err = -ENOMEM;
1928 				break;
1929 			}
1930 
1931 			copied += read;
1932 
1933 			err = transport->notify_recv_post_dequeue(
1934 					vsk, target, read,
1935 					!(flags & MSG_PEEK), &recv_data);
1936 			if (err < 0)
1937 				goto out;
1938 
1939 			if (read >= target || flags & MSG_PEEK)
1940 				break;
1941 
1942 			target -= read;
1943 		}
1944 	}
1945 
1946 	if (sk->sk_err)
1947 		err = -sk->sk_err;
1948 	else if (sk->sk_shutdown & RCV_SHUTDOWN)
1949 		err = 0;
1950 
1951 	if (copied > 0)
1952 		err = copied;
1953 
1954 out:
1955 	release_sock(sk);
1956 	return err;
1957 }
1958 
1959 static const struct proto_ops vsock_stream_ops = {
1960 	.family = PF_VSOCK,
1961 	.owner = THIS_MODULE,
1962 	.release = vsock_release,
1963 	.bind = vsock_bind,
1964 	.connect = vsock_stream_connect,
1965 	.socketpair = sock_no_socketpair,
1966 	.accept = vsock_accept,
1967 	.getname = vsock_getname,
1968 	.poll = vsock_poll,
1969 	.ioctl = sock_no_ioctl,
1970 	.listen = vsock_listen,
1971 	.shutdown = vsock_shutdown,
1972 	.setsockopt = vsock_stream_setsockopt,
1973 	.getsockopt = vsock_stream_getsockopt,
1974 	.sendmsg = vsock_stream_sendmsg,
1975 	.recvmsg = vsock_stream_recvmsg,
1976 	.mmap = sock_no_mmap,
1977 	.sendpage = sock_no_sendpage,
1978 };
1979 
1980 static int vsock_create(struct net *net, struct socket *sock,
1981 			int protocol, int kern)
1982 {
1983 	struct vsock_sock *vsk;
1984 	struct sock *sk;
1985 	int ret;
1986 
1987 	if (!sock)
1988 		return -EINVAL;
1989 
1990 	if (protocol && protocol != PF_VSOCK)
1991 		return -EPROTONOSUPPORT;
1992 
1993 	switch (sock->type) {
1994 	case SOCK_DGRAM:
1995 		sock->ops = &vsock_dgram_ops;
1996 		break;
1997 	case SOCK_STREAM:
1998 		sock->ops = &vsock_stream_ops;
1999 		break;
2000 	default:
2001 		return -ESOCKTNOSUPPORT;
2002 	}
2003 
2004 	sock->state = SS_UNCONNECTED;
2005 
2006 	sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2007 	if (!sk)
2008 		return -ENOMEM;
2009 
2010 	vsk = vsock_sk(sk);
2011 
2012 	if (sock->type == SOCK_DGRAM) {
2013 		ret = vsock_assign_transport(vsk, NULL);
2014 		if (ret < 0) {
2015 			sock_put(sk);
2016 			return ret;
2017 		}
2018 	}
2019 
2020 	vsock_insert_unbound(vsk);
2021 
2022 	return 0;
2023 }
2024 
2025 static const struct net_proto_family vsock_family_ops = {
2026 	.family = AF_VSOCK,
2027 	.create = vsock_create,
2028 	.owner = THIS_MODULE,
2029 };
2030 
2031 static long vsock_dev_do_ioctl(struct file *filp,
2032 			       unsigned int cmd, void __user *ptr)
2033 {
2034 	u32 __user *p = ptr;
2035 	u32 cid = VMADDR_CID_ANY;
2036 	int retval = 0;
2037 
2038 	switch (cmd) {
2039 	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2040 		/* To be compatible with the VMCI behavior, we prioritize the
2041 		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2042 		 */
2043 		if (transport_g2h)
2044 			cid = transport_g2h->get_local_cid();
2045 		else if (transport_h2g)
2046 			cid = transport_h2g->get_local_cid();
2047 
2048 		if (put_user(cid, p) != 0)
2049 			retval = -EFAULT;
2050 		break;
2051 
2052 	default:
2053 		pr_err("Unknown ioctl %d\n", cmd);
2054 		retval = -EINVAL;
2055 	}
2056 
2057 	return retval;
2058 }
2059 
2060 static long vsock_dev_ioctl(struct file *filp,
2061 			    unsigned int cmd, unsigned long arg)
2062 {
2063 	return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2064 }
2065 
2066 #ifdef CONFIG_COMPAT
2067 static long vsock_dev_compat_ioctl(struct file *filp,
2068 				   unsigned int cmd, unsigned long arg)
2069 {
2070 	return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2071 }
2072 #endif
2073 
2074 static const struct file_operations vsock_device_ops = {
2075 	.owner		= THIS_MODULE,
2076 	.unlocked_ioctl	= vsock_dev_ioctl,
2077 #ifdef CONFIG_COMPAT
2078 	.compat_ioctl	= vsock_dev_compat_ioctl,
2079 #endif
2080 	.open		= nonseekable_open,
2081 };
2082 
2083 static struct miscdevice vsock_device = {
2084 	.name		= "vsock",
2085 	.fops		= &vsock_device_ops,
2086 };
2087 
2088 static int __init vsock_init(void)
2089 {
2090 	int err = 0;
2091 
2092 	vsock_init_tables();
2093 
2094 	vsock_proto.owner = THIS_MODULE;
2095 	vsock_device.minor = MISC_DYNAMIC_MINOR;
2096 	err = misc_register(&vsock_device);
2097 	if (err) {
2098 		pr_err("Failed to register misc device\n");
2099 		goto err_reset_transport;
2100 	}
2101 
2102 	err = proto_register(&vsock_proto, 1);	/* we want our slab */
2103 	if (err) {
2104 		pr_err("Cannot register vsock protocol\n");
2105 		goto err_deregister_misc;
2106 	}
2107 
2108 	err = sock_register(&vsock_family_ops);
2109 	if (err) {
2110 		pr_err("could not register af_vsock (%d) address family: %d\n",
2111 		       AF_VSOCK, err);
2112 		goto err_unregister_proto;
2113 	}
2114 
2115 	return 0;
2116 
2117 err_unregister_proto:
2118 	proto_unregister(&vsock_proto);
2119 err_deregister_misc:
2120 	misc_deregister(&vsock_device);
2121 err_reset_transport:
2122 	return err;
2123 }
2124 
2125 static void __exit vsock_exit(void)
2126 {
2127 	misc_deregister(&vsock_device);
2128 	sock_unregister(AF_VSOCK);
2129 	proto_unregister(&vsock_proto);
2130 }
2131 
2132 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2133 {
2134 	return vsk->transport;
2135 }
2136 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2137 
2138 int vsock_core_register(const struct vsock_transport *t, int features)
2139 {
2140 	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram;
2141 	int err = mutex_lock_interruptible(&vsock_register_mutex);
2142 
2143 	if (err)
2144 		return err;
2145 
2146 	t_h2g = transport_h2g;
2147 	t_g2h = transport_g2h;
2148 	t_dgram = transport_dgram;
2149 
2150 	if (features & VSOCK_TRANSPORT_F_H2G) {
2151 		if (t_h2g) {
2152 			err = -EBUSY;
2153 			goto err_busy;
2154 		}
2155 		t_h2g = t;
2156 	}
2157 
2158 	if (features & VSOCK_TRANSPORT_F_G2H) {
2159 		if (t_g2h) {
2160 			err = -EBUSY;
2161 			goto err_busy;
2162 		}
2163 		t_g2h = t;
2164 	}
2165 
2166 	if (features & VSOCK_TRANSPORT_F_DGRAM) {
2167 		if (t_dgram) {
2168 			err = -EBUSY;
2169 			goto err_busy;
2170 		}
2171 		t_dgram = t;
2172 	}
2173 
2174 	transport_h2g = t_h2g;
2175 	transport_g2h = t_g2h;
2176 	transport_dgram = t_dgram;
2177 
2178 err_busy:
2179 	mutex_unlock(&vsock_register_mutex);
2180 	return err;
2181 }
2182 EXPORT_SYMBOL_GPL(vsock_core_register);
2183 
2184 void vsock_core_unregister(const struct vsock_transport *t)
2185 {
2186 	mutex_lock(&vsock_register_mutex);
2187 
2188 	if (transport_h2g == t)
2189 		transport_h2g = NULL;
2190 
2191 	if (transport_g2h == t)
2192 		transport_g2h = NULL;
2193 
2194 	if (transport_dgram == t)
2195 		transport_dgram = NULL;
2196 
2197 	mutex_unlock(&vsock_register_mutex);
2198 }
2199 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2200 
2201 module_init(vsock_init);
2202 module_exit(vsock_exit);
2203 
2204 MODULE_AUTHOR("VMware, Inc.");
2205 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2206 MODULE_VERSION("1.0.2.0-k");
2207 MODULE_LICENSE("GPL v2");
2208