xref: /openbmc/linux/net/vmw_vsock/af_vsock.c (revision 7a010c3c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VMware vSockets Driver
4  *
5  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
6  */
7 
8 /* Implementation notes:
9  *
10  * - There are two kinds of sockets: those created by user action (such as
11  * calling socket(2)) and those created by incoming connection request packets.
12  *
13  * - There are two "global" tables, one for bound sockets (sockets that have
14  * specified an address that they are responsible for) and one for connected
15  * sockets (sockets that have established a connection with another socket).
16  * These tables are "global" in that all sockets on the system are placed
17  * within them. - Note, though, that the bound table contains an extra entry
18  * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
19  * that list. The bound table is used solely for lookup of sockets when packets
20  * are received and that's not necessary for SOCK_DGRAM sockets since we create
21  * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
22  * sockets out of the bound hash buckets will reduce the chance of collisions
23  * when looking for SOCK_STREAM sockets and prevents us from having to check the
24  * socket type in the hash table lookups.
25  *
26  * - Sockets created by user action will either be "client" sockets that
27  * initiate a connection or "server" sockets that listen for connections; we do
28  * not support simultaneous connects (two "client" sockets connecting).
29  *
30  * - "Server" sockets are referred to as listener sockets throughout this
31  * implementation because they are in the TCP_LISTEN state.  When a
32  * connection request is received (the second kind of socket mentioned above),
33  * we create a new socket and refer to it as a pending socket.  These pending
34  * sockets are placed on the pending connection list of the listener socket.
35  * When future packets are received for the address the listener socket is
36  * bound to, we check if the source of the packet is from one that has an
37  * existing pending connection.  If it does, we process the packet for the
38  * pending socket.  When that socket reaches the connected state, it is removed
39  * from the listener socket's pending list and enqueued in the listener
40  * socket's accept queue.  Callers of accept(2) will accept connected sockets
41  * from the listener socket's accept queue.  If the socket cannot be accepted
42  * for some reason then it is marked rejected.  Once the connection is
43  * accepted, it is owned by the user process and the responsibility for cleanup
44  * falls with that user process.
45  *
46  * - It is possible that these pending sockets will never reach the connected
47  * state; in fact, we may never receive another packet after the connection
48  * request.  Because of this, we must schedule a cleanup function to run in the
49  * future, after some amount of time passes where a connection should have been
50  * established.  This function ensures that the socket is off all lists so it
51  * cannot be retrieved, then drops all references to the socket so it is cleaned
52  * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
53  * function will also cleanup rejected sockets, those that reach the connected
54  * state but leave it before they have been accepted.
55  *
56  * - Lock ordering for pending or accept queue sockets is:
57  *
58  *     lock_sock(listener);
59  *     lock_sock_nested(pending, SINGLE_DEPTH_NESTING);
60  *
61  * Using explicit nested locking keeps lockdep happy since normally only one
62  * lock of a given class may be taken at a time.
63  *
64  * - Sockets created by user action will be cleaned up when the user process
65  * calls close(2), causing our release implementation to be called. Our release
66  * implementation will perform some cleanup then drop the last reference so our
67  * sk_destruct implementation is invoked.  Our sk_destruct implementation will
68  * perform additional cleanup that's common for both types of sockets.
69  *
70  * - A socket's reference count is what ensures that the structure won't be
71  * freed.  Each entry in a list (such as the "global" bound and connected tables
72  * and the listener socket's pending list and connected queue) ensures a
73  * reference.  When we defer work until process context and pass a socket as our
74  * argument, we must ensure the reference count is increased to ensure the
75  * socket isn't freed before the function is run; the deferred function will
76  * then drop the reference.
77  *
78  * - sk->sk_state uses the TCP state constants because they are widely used by
79  * other address families and exposed to userspace tools like ss(8):
80  *
81  *   TCP_CLOSE - unconnected
82  *   TCP_SYN_SENT - connecting
83  *   TCP_ESTABLISHED - connected
84  *   TCP_CLOSING - disconnecting
85  *   TCP_LISTEN - listening
86  */
87 
88 #include <linux/types.h>
89 #include <linux/bitops.h>
90 #include <linux/cred.h>
91 #include <linux/init.h>
92 #include <linux/io.h>
93 #include <linux/kernel.h>
94 #include <linux/sched/signal.h>
95 #include <linux/kmod.h>
96 #include <linux/list.h>
97 #include <linux/miscdevice.h>
98 #include <linux/module.h>
99 #include <linux/mutex.h>
100 #include <linux/net.h>
101 #include <linux/poll.h>
102 #include <linux/random.h>
103 #include <linux/skbuff.h>
104 #include <linux/smp.h>
105 #include <linux/socket.h>
106 #include <linux/stddef.h>
107 #include <linux/unistd.h>
108 #include <linux/wait.h>
109 #include <linux/workqueue.h>
110 #include <net/sock.h>
111 #include <net/af_vsock.h>
112 
113 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
114 static void vsock_sk_destruct(struct sock *sk);
115 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
116 
117 /* Protocol family. */
118 static struct proto vsock_proto = {
119 	.name = "AF_VSOCK",
120 	.owner = THIS_MODULE,
121 	.obj_size = sizeof(struct vsock_sock),
122 };
123 
124 /* The default peer timeout indicates how long we will wait for a peer response
125  * to a control message.
126  */
127 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
128 
129 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
130 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
131 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
132 
133 /* Transport used for host->guest communication */
134 static const struct vsock_transport *transport_h2g;
135 /* Transport used for guest->host communication */
136 static const struct vsock_transport *transport_g2h;
137 /* Transport used for DGRAM communication */
138 static const struct vsock_transport *transport_dgram;
139 /* Transport used for local communication */
140 static const struct vsock_transport *transport_local;
141 static DEFINE_MUTEX(vsock_register_mutex);
142 
143 /**** UTILS ****/
144 
145 /* Each bound VSocket is stored in the bind hash table and each connected
146  * VSocket is stored in the connected hash table.
147  *
148  * Unbound sockets are all put on the same list attached to the end of the hash
149  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
150  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
151  * represents the list that addr hashes to).
152  *
153  * Specifically, we initialize the vsock_bind_table array to a size of
154  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
155  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
156  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
157  * mods with VSOCK_HASH_SIZE to ensure this.
158  */
159 #define MAX_PORT_RETRIES        24
160 
161 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
162 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
163 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
164 
165 /* XXX This can probably be implemented in a better way. */
166 #define VSOCK_CONN_HASH(src, dst)				\
167 	(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
168 #define vsock_connected_sockets(src, dst)		\
169 	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
170 #define vsock_connected_sockets_vsk(vsk)				\
171 	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
172 
173 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
174 EXPORT_SYMBOL_GPL(vsock_bind_table);
175 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
176 EXPORT_SYMBOL_GPL(vsock_connected_table);
177 DEFINE_SPINLOCK(vsock_table_lock);
178 EXPORT_SYMBOL_GPL(vsock_table_lock);
179 
180 /* Autobind this socket to the local address if necessary. */
181 static int vsock_auto_bind(struct vsock_sock *vsk)
182 {
183 	struct sock *sk = sk_vsock(vsk);
184 	struct sockaddr_vm local_addr;
185 
186 	if (vsock_addr_bound(&vsk->local_addr))
187 		return 0;
188 	vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
189 	return __vsock_bind(sk, &local_addr);
190 }
191 
192 static void vsock_init_tables(void)
193 {
194 	int i;
195 
196 	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
197 		INIT_LIST_HEAD(&vsock_bind_table[i]);
198 
199 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
200 		INIT_LIST_HEAD(&vsock_connected_table[i]);
201 }
202 
203 static void __vsock_insert_bound(struct list_head *list,
204 				 struct vsock_sock *vsk)
205 {
206 	sock_hold(&vsk->sk);
207 	list_add(&vsk->bound_table, list);
208 }
209 
210 static void __vsock_insert_connected(struct list_head *list,
211 				     struct vsock_sock *vsk)
212 {
213 	sock_hold(&vsk->sk);
214 	list_add(&vsk->connected_table, list);
215 }
216 
217 static void __vsock_remove_bound(struct vsock_sock *vsk)
218 {
219 	list_del_init(&vsk->bound_table);
220 	sock_put(&vsk->sk);
221 }
222 
223 static void __vsock_remove_connected(struct vsock_sock *vsk)
224 {
225 	list_del_init(&vsk->connected_table);
226 	sock_put(&vsk->sk);
227 }
228 
229 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
230 {
231 	struct vsock_sock *vsk;
232 
233 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
234 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
235 			return sk_vsock(vsk);
236 
237 		if (addr->svm_port == vsk->local_addr.svm_port &&
238 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
239 		     addr->svm_cid == VMADDR_CID_ANY))
240 			return sk_vsock(vsk);
241 	}
242 
243 	return NULL;
244 }
245 
246 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
247 						  struct sockaddr_vm *dst)
248 {
249 	struct vsock_sock *vsk;
250 
251 	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
252 			    connected_table) {
253 		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
254 		    dst->svm_port == vsk->local_addr.svm_port) {
255 			return sk_vsock(vsk);
256 		}
257 	}
258 
259 	return NULL;
260 }
261 
262 static void vsock_insert_unbound(struct vsock_sock *vsk)
263 {
264 	spin_lock_bh(&vsock_table_lock);
265 	__vsock_insert_bound(vsock_unbound_sockets, vsk);
266 	spin_unlock_bh(&vsock_table_lock);
267 }
268 
269 void vsock_insert_connected(struct vsock_sock *vsk)
270 {
271 	struct list_head *list = vsock_connected_sockets(
272 		&vsk->remote_addr, &vsk->local_addr);
273 
274 	spin_lock_bh(&vsock_table_lock);
275 	__vsock_insert_connected(list, vsk);
276 	spin_unlock_bh(&vsock_table_lock);
277 }
278 EXPORT_SYMBOL_GPL(vsock_insert_connected);
279 
280 void vsock_remove_bound(struct vsock_sock *vsk)
281 {
282 	spin_lock_bh(&vsock_table_lock);
283 	if (__vsock_in_bound_table(vsk))
284 		__vsock_remove_bound(vsk);
285 	spin_unlock_bh(&vsock_table_lock);
286 }
287 EXPORT_SYMBOL_GPL(vsock_remove_bound);
288 
289 void vsock_remove_connected(struct vsock_sock *vsk)
290 {
291 	spin_lock_bh(&vsock_table_lock);
292 	if (__vsock_in_connected_table(vsk))
293 		__vsock_remove_connected(vsk);
294 	spin_unlock_bh(&vsock_table_lock);
295 }
296 EXPORT_SYMBOL_GPL(vsock_remove_connected);
297 
298 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
299 {
300 	struct sock *sk;
301 
302 	spin_lock_bh(&vsock_table_lock);
303 	sk = __vsock_find_bound_socket(addr);
304 	if (sk)
305 		sock_hold(sk);
306 
307 	spin_unlock_bh(&vsock_table_lock);
308 
309 	return sk;
310 }
311 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
312 
313 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
314 					 struct sockaddr_vm *dst)
315 {
316 	struct sock *sk;
317 
318 	spin_lock_bh(&vsock_table_lock);
319 	sk = __vsock_find_connected_socket(src, dst);
320 	if (sk)
321 		sock_hold(sk);
322 
323 	spin_unlock_bh(&vsock_table_lock);
324 
325 	return sk;
326 }
327 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
328 
329 void vsock_remove_sock(struct vsock_sock *vsk)
330 {
331 	vsock_remove_bound(vsk);
332 	vsock_remove_connected(vsk);
333 }
334 EXPORT_SYMBOL_GPL(vsock_remove_sock);
335 
336 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
337 {
338 	int i;
339 
340 	spin_lock_bh(&vsock_table_lock);
341 
342 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
343 		struct vsock_sock *vsk;
344 		list_for_each_entry(vsk, &vsock_connected_table[i],
345 				    connected_table)
346 			fn(sk_vsock(vsk));
347 	}
348 
349 	spin_unlock_bh(&vsock_table_lock);
350 }
351 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
352 
353 void vsock_add_pending(struct sock *listener, struct sock *pending)
354 {
355 	struct vsock_sock *vlistener;
356 	struct vsock_sock *vpending;
357 
358 	vlistener = vsock_sk(listener);
359 	vpending = vsock_sk(pending);
360 
361 	sock_hold(pending);
362 	sock_hold(listener);
363 	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
364 }
365 EXPORT_SYMBOL_GPL(vsock_add_pending);
366 
367 void vsock_remove_pending(struct sock *listener, struct sock *pending)
368 {
369 	struct vsock_sock *vpending = vsock_sk(pending);
370 
371 	list_del_init(&vpending->pending_links);
372 	sock_put(listener);
373 	sock_put(pending);
374 }
375 EXPORT_SYMBOL_GPL(vsock_remove_pending);
376 
377 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
378 {
379 	struct vsock_sock *vlistener;
380 	struct vsock_sock *vconnected;
381 
382 	vlistener = vsock_sk(listener);
383 	vconnected = vsock_sk(connected);
384 
385 	sock_hold(connected);
386 	sock_hold(listener);
387 	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
388 }
389 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
390 
391 static bool vsock_use_local_transport(unsigned int remote_cid)
392 {
393 	if (!transport_local)
394 		return false;
395 
396 	if (remote_cid == VMADDR_CID_LOCAL)
397 		return true;
398 
399 	if (transport_g2h) {
400 		return remote_cid == transport_g2h->get_local_cid();
401 	} else {
402 		return remote_cid == VMADDR_CID_HOST;
403 	}
404 }
405 
406 static void vsock_deassign_transport(struct vsock_sock *vsk)
407 {
408 	if (!vsk->transport)
409 		return;
410 
411 	vsk->transport->destruct(vsk);
412 	module_put(vsk->transport->module);
413 	vsk->transport = NULL;
414 }
415 
416 /* Assign a transport to a socket and call the .init transport callback.
417  *
418  * Note: for connection oriented socket this must be called when vsk->remote_addr
419  * is set (e.g. during the connect() or when a connection request on a listener
420  * socket is received).
421  * The vsk->remote_addr is used to decide which transport to use:
422  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
423  *    g2h is not loaded, will use local transport;
424  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
425  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
426  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
427  */
428 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
429 {
430 	const struct vsock_transport *new_transport;
431 	struct sock *sk = sk_vsock(vsk);
432 	unsigned int remote_cid = vsk->remote_addr.svm_cid;
433 	__u8 remote_flags;
434 	int ret;
435 
436 	/* If the packet is coming with the source and destination CIDs higher
437 	 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
438 	 * forwarded to the host should be established. Then the host will
439 	 * need to forward the packets to the guest.
440 	 *
441 	 * The flag is set on the (listen) receive path (psk is not NULL). On
442 	 * the connect path the flag can be set by the user space application.
443 	 */
444 	if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
445 	    vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
446 		vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
447 
448 	remote_flags = vsk->remote_addr.svm_flags;
449 
450 	switch (sk->sk_type) {
451 	case SOCK_DGRAM:
452 		new_transport = transport_dgram;
453 		break;
454 	case SOCK_STREAM:
455 	case SOCK_SEQPACKET:
456 		if (vsock_use_local_transport(remote_cid))
457 			new_transport = transport_local;
458 		else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
459 			 (remote_flags & VMADDR_FLAG_TO_HOST))
460 			new_transport = transport_g2h;
461 		else
462 			new_transport = transport_h2g;
463 		break;
464 	default:
465 		return -ESOCKTNOSUPPORT;
466 	}
467 
468 	if (vsk->transport) {
469 		if (vsk->transport == new_transport)
470 			return 0;
471 
472 		/* transport->release() must be called with sock lock acquired.
473 		 * This path can only be taken during vsock_connect(), where we
474 		 * have already held the sock lock. In the other cases, this
475 		 * function is called on a new socket which is not assigned to
476 		 * any transport.
477 		 */
478 		vsk->transport->release(vsk);
479 		vsock_deassign_transport(vsk);
480 	}
481 
482 	/* We increase the module refcnt to prevent the transport unloading
483 	 * while there are open sockets assigned to it.
484 	 */
485 	if (!new_transport || !try_module_get(new_transport->module))
486 		return -ENODEV;
487 
488 	if (sk->sk_type == SOCK_SEQPACKET) {
489 		if (!new_transport->seqpacket_allow ||
490 		    !new_transport->seqpacket_allow(remote_cid)) {
491 			module_put(new_transport->module);
492 			return -ESOCKTNOSUPPORT;
493 		}
494 	}
495 
496 	ret = new_transport->init(vsk, psk);
497 	if (ret) {
498 		module_put(new_transport->module);
499 		return ret;
500 	}
501 
502 	vsk->transport = new_transport;
503 
504 	return 0;
505 }
506 EXPORT_SYMBOL_GPL(vsock_assign_transport);
507 
508 bool vsock_find_cid(unsigned int cid)
509 {
510 	if (transport_g2h && cid == transport_g2h->get_local_cid())
511 		return true;
512 
513 	if (transport_h2g && cid == VMADDR_CID_HOST)
514 		return true;
515 
516 	if (transport_local && cid == VMADDR_CID_LOCAL)
517 		return true;
518 
519 	return false;
520 }
521 EXPORT_SYMBOL_GPL(vsock_find_cid);
522 
523 static struct sock *vsock_dequeue_accept(struct sock *listener)
524 {
525 	struct vsock_sock *vlistener;
526 	struct vsock_sock *vconnected;
527 
528 	vlistener = vsock_sk(listener);
529 
530 	if (list_empty(&vlistener->accept_queue))
531 		return NULL;
532 
533 	vconnected = list_entry(vlistener->accept_queue.next,
534 				struct vsock_sock, accept_queue);
535 
536 	list_del_init(&vconnected->accept_queue);
537 	sock_put(listener);
538 	/* The caller will need a reference on the connected socket so we let
539 	 * it call sock_put().
540 	 */
541 
542 	return sk_vsock(vconnected);
543 }
544 
545 static bool vsock_is_accept_queue_empty(struct sock *sk)
546 {
547 	struct vsock_sock *vsk = vsock_sk(sk);
548 	return list_empty(&vsk->accept_queue);
549 }
550 
551 static bool vsock_is_pending(struct sock *sk)
552 {
553 	struct vsock_sock *vsk = vsock_sk(sk);
554 	return !list_empty(&vsk->pending_links);
555 }
556 
557 static int vsock_send_shutdown(struct sock *sk, int mode)
558 {
559 	struct vsock_sock *vsk = vsock_sk(sk);
560 
561 	if (!vsk->transport)
562 		return -ENODEV;
563 
564 	return vsk->transport->shutdown(vsk, mode);
565 }
566 
567 static void vsock_pending_work(struct work_struct *work)
568 {
569 	struct sock *sk;
570 	struct sock *listener;
571 	struct vsock_sock *vsk;
572 	bool cleanup;
573 
574 	vsk = container_of(work, struct vsock_sock, pending_work.work);
575 	sk = sk_vsock(vsk);
576 	listener = vsk->listener;
577 	cleanup = true;
578 
579 	lock_sock(listener);
580 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
581 
582 	if (vsock_is_pending(sk)) {
583 		vsock_remove_pending(listener, sk);
584 
585 		sk_acceptq_removed(listener);
586 	} else if (!vsk->rejected) {
587 		/* We are not on the pending list and accept() did not reject
588 		 * us, so we must have been accepted by our user process.  We
589 		 * just need to drop our references to the sockets and be on
590 		 * our way.
591 		 */
592 		cleanup = false;
593 		goto out;
594 	}
595 
596 	/* We need to remove ourself from the global connected sockets list so
597 	 * incoming packets can't find this socket, and to reduce the reference
598 	 * count.
599 	 */
600 	vsock_remove_connected(vsk);
601 
602 	sk->sk_state = TCP_CLOSE;
603 
604 out:
605 	release_sock(sk);
606 	release_sock(listener);
607 	if (cleanup)
608 		sock_put(sk);
609 
610 	sock_put(sk);
611 	sock_put(listener);
612 }
613 
614 /**** SOCKET OPERATIONS ****/
615 
616 static int __vsock_bind_connectible(struct vsock_sock *vsk,
617 				    struct sockaddr_vm *addr)
618 {
619 	static u32 port;
620 	struct sockaddr_vm new_addr;
621 
622 	if (!port)
623 		port = LAST_RESERVED_PORT + 1 +
624 			prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
625 
626 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
627 
628 	if (addr->svm_port == VMADDR_PORT_ANY) {
629 		bool found = false;
630 		unsigned int i;
631 
632 		for (i = 0; i < MAX_PORT_RETRIES; i++) {
633 			if (port <= LAST_RESERVED_PORT)
634 				port = LAST_RESERVED_PORT + 1;
635 
636 			new_addr.svm_port = port++;
637 
638 			if (!__vsock_find_bound_socket(&new_addr)) {
639 				found = true;
640 				break;
641 			}
642 		}
643 
644 		if (!found)
645 			return -EADDRNOTAVAIL;
646 	} else {
647 		/* If port is in reserved range, ensure caller
648 		 * has necessary privileges.
649 		 */
650 		if (addr->svm_port <= LAST_RESERVED_PORT &&
651 		    !capable(CAP_NET_BIND_SERVICE)) {
652 			return -EACCES;
653 		}
654 
655 		if (__vsock_find_bound_socket(&new_addr))
656 			return -EADDRINUSE;
657 	}
658 
659 	vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
660 
661 	/* Remove connection oriented sockets from the unbound list and add them
662 	 * to the hash table for easy lookup by its address.  The unbound list
663 	 * is simply an extra entry at the end of the hash table, a trick used
664 	 * by AF_UNIX.
665 	 */
666 	__vsock_remove_bound(vsk);
667 	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
668 
669 	return 0;
670 }
671 
672 static int __vsock_bind_dgram(struct vsock_sock *vsk,
673 			      struct sockaddr_vm *addr)
674 {
675 	return vsk->transport->dgram_bind(vsk, addr);
676 }
677 
678 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
679 {
680 	struct vsock_sock *vsk = vsock_sk(sk);
681 	int retval;
682 
683 	/* First ensure this socket isn't already bound. */
684 	if (vsock_addr_bound(&vsk->local_addr))
685 		return -EINVAL;
686 
687 	/* Now bind to the provided address or select appropriate values if
688 	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
689 	 * like AF_INET prevents binding to a non-local IP address (in most
690 	 * cases), we only allow binding to a local CID.
691 	 */
692 	if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
693 		return -EADDRNOTAVAIL;
694 
695 	switch (sk->sk_socket->type) {
696 	case SOCK_STREAM:
697 	case SOCK_SEQPACKET:
698 		spin_lock_bh(&vsock_table_lock);
699 		retval = __vsock_bind_connectible(vsk, addr);
700 		spin_unlock_bh(&vsock_table_lock);
701 		break;
702 
703 	case SOCK_DGRAM:
704 		retval = __vsock_bind_dgram(vsk, addr);
705 		break;
706 
707 	default:
708 		retval = -EINVAL;
709 		break;
710 	}
711 
712 	return retval;
713 }
714 
715 static void vsock_connect_timeout(struct work_struct *work);
716 
717 static struct sock *__vsock_create(struct net *net,
718 				   struct socket *sock,
719 				   struct sock *parent,
720 				   gfp_t priority,
721 				   unsigned short type,
722 				   int kern)
723 {
724 	struct sock *sk;
725 	struct vsock_sock *psk;
726 	struct vsock_sock *vsk;
727 
728 	sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
729 	if (!sk)
730 		return NULL;
731 
732 	sock_init_data(sock, sk);
733 
734 	/* sk->sk_type is normally set in sock_init_data, but only if sock is
735 	 * non-NULL. We make sure that our sockets always have a type by
736 	 * setting it here if needed.
737 	 */
738 	if (!sock)
739 		sk->sk_type = type;
740 
741 	vsk = vsock_sk(sk);
742 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
743 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
744 
745 	sk->sk_destruct = vsock_sk_destruct;
746 	sk->sk_backlog_rcv = vsock_queue_rcv_skb;
747 	sock_reset_flag(sk, SOCK_DONE);
748 
749 	INIT_LIST_HEAD(&vsk->bound_table);
750 	INIT_LIST_HEAD(&vsk->connected_table);
751 	vsk->listener = NULL;
752 	INIT_LIST_HEAD(&vsk->pending_links);
753 	INIT_LIST_HEAD(&vsk->accept_queue);
754 	vsk->rejected = false;
755 	vsk->sent_request = false;
756 	vsk->ignore_connecting_rst = false;
757 	vsk->peer_shutdown = 0;
758 	INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
759 	INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
760 
761 	psk = parent ? vsock_sk(parent) : NULL;
762 	if (parent) {
763 		vsk->trusted = psk->trusted;
764 		vsk->owner = get_cred(psk->owner);
765 		vsk->connect_timeout = psk->connect_timeout;
766 		vsk->buffer_size = psk->buffer_size;
767 		vsk->buffer_min_size = psk->buffer_min_size;
768 		vsk->buffer_max_size = psk->buffer_max_size;
769 		security_sk_clone(parent, sk);
770 	} else {
771 		vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
772 		vsk->owner = get_current_cred();
773 		vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
774 		vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
775 		vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
776 		vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
777 	}
778 
779 	return sk;
780 }
781 
782 static bool sock_type_connectible(u16 type)
783 {
784 	return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
785 }
786 
787 static void __vsock_release(struct sock *sk, int level)
788 {
789 	if (sk) {
790 		struct sock *pending;
791 		struct vsock_sock *vsk;
792 
793 		vsk = vsock_sk(sk);
794 		pending = NULL;	/* Compiler warning. */
795 
796 		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
797 		 * version to avoid the warning "possible recursive locking
798 		 * detected". When "level" is 0, lock_sock_nested(sk, level)
799 		 * is the same as lock_sock(sk).
800 		 */
801 		lock_sock_nested(sk, level);
802 
803 		if (vsk->transport)
804 			vsk->transport->release(vsk);
805 		else if (sock_type_connectible(sk->sk_type))
806 			vsock_remove_sock(vsk);
807 
808 		sock_orphan(sk);
809 		sk->sk_shutdown = SHUTDOWN_MASK;
810 
811 		skb_queue_purge(&sk->sk_receive_queue);
812 
813 		/* Clean up any sockets that never were accepted. */
814 		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
815 			__vsock_release(pending, SINGLE_DEPTH_NESTING);
816 			sock_put(pending);
817 		}
818 
819 		release_sock(sk);
820 		sock_put(sk);
821 	}
822 }
823 
824 static void vsock_sk_destruct(struct sock *sk)
825 {
826 	struct vsock_sock *vsk = vsock_sk(sk);
827 
828 	vsock_deassign_transport(vsk);
829 
830 	/* When clearing these addresses, there's no need to set the family and
831 	 * possibly register the address family with the kernel.
832 	 */
833 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
834 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
835 
836 	put_cred(vsk->owner);
837 }
838 
839 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
840 {
841 	int err;
842 
843 	err = sock_queue_rcv_skb(sk, skb);
844 	if (err)
845 		kfree_skb(skb);
846 
847 	return err;
848 }
849 
850 struct sock *vsock_create_connected(struct sock *parent)
851 {
852 	return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
853 			      parent->sk_type, 0);
854 }
855 EXPORT_SYMBOL_GPL(vsock_create_connected);
856 
857 s64 vsock_stream_has_data(struct vsock_sock *vsk)
858 {
859 	return vsk->transport->stream_has_data(vsk);
860 }
861 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
862 
863 static s64 vsock_connectible_has_data(struct vsock_sock *vsk)
864 {
865 	struct sock *sk = sk_vsock(vsk);
866 
867 	if (sk->sk_type == SOCK_SEQPACKET)
868 		return vsk->transport->seqpacket_has_data(vsk);
869 	else
870 		return vsock_stream_has_data(vsk);
871 }
872 
873 s64 vsock_stream_has_space(struct vsock_sock *vsk)
874 {
875 	return vsk->transport->stream_has_space(vsk);
876 }
877 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
878 
879 static int vsock_release(struct socket *sock)
880 {
881 	__vsock_release(sock->sk, 0);
882 	sock->sk = NULL;
883 	sock->state = SS_FREE;
884 
885 	return 0;
886 }
887 
888 static int
889 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
890 {
891 	int err;
892 	struct sock *sk;
893 	struct sockaddr_vm *vm_addr;
894 
895 	sk = sock->sk;
896 
897 	if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
898 		return -EINVAL;
899 
900 	lock_sock(sk);
901 	err = __vsock_bind(sk, vm_addr);
902 	release_sock(sk);
903 
904 	return err;
905 }
906 
907 static int vsock_getname(struct socket *sock,
908 			 struct sockaddr *addr, int peer)
909 {
910 	int err;
911 	struct sock *sk;
912 	struct vsock_sock *vsk;
913 	struct sockaddr_vm *vm_addr;
914 
915 	sk = sock->sk;
916 	vsk = vsock_sk(sk);
917 	err = 0;
918 
919 	lock_sock(sk);
920 
921 	if (peer) {
922 		if (sock->state != SS_CONNECTED) {
923 			err = -ENOTCONN;
924 			goto out;
925 		}
926 		vm_addr = &vsk->remote_addr;
927 	} else {
928 		vm_addr = &vsk->local_addr;
929 	}
930 
931 	if (!vm_addr) {
932 		err = -EINVAL;
933 		goto out;
934 	}
935 
936 	/* sys_getsockname() and sys_getpeername() pass us a
937 	 * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
938 	 * that macro is defined in socket.c instead of .h, so we hardcode its
939 	 * value here.
940 	 */
941 	BUILD_BUG_ON(sizeof(*vm_addr) > 128);
942 	memcpy(addr, vm_addr, sizeof(*vm_addr));
943 	err = sizeof(*vm_addr);
944 
945 out:
946 	release_sock(sk);
947 	return err;
948 }
949 
950 static int vsock_shutdown(struct socket *sock, int mode)
951 {
952 	int err;
953 	struct sock *sk;
954 
955 	/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
956 	 * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
957 	 * here like the other address families do.  Note also that the
958 	 * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
959 	 * which is what we want.
960 	 */
961 	mode++;
962 
963 	if ((mode & ~SHUTDOWN_MASK) || !mode)
964 		return -EINVAL;
965 
966 	/* If this is a connection oriented socket and it is not connected then
967 	 * bail out immediately.  If it is a DGRAM socket then we must first
968 	 * kick the socket so that it wakes up from any sleeping calls, for
969 	 * example recv(), and then afterwards return the error.
970 	 */
971 
972 	sk = sock->sk;
973 
974 	lock_sock(sk);
975 	if (sock->state == SS_UNCONNECTED) {
976 		err = -ENOTCONN;
977 		if (sock_type_connectible(sk->sk_type))
978 			goto out;
979 	} else {
980 		sock->state = SS_DISCONNECTING;
981 		err = 0;
982 	}
983 
984 	/* Receive and send shutdowns are treated alike. */
985 	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
986 	if (mode) {
987 		sk->sk_shutdown |= mode;
988 		sk->sk_state_change(sk);
989 
990 		if (sock_type_connectible(sk->sk_type)) {
991 			sock_reset_flag(sk, SOCK_DONE);
992 			vsock_send_shutdown(sk, mode);
993 		}
994 	}
995 
996 out:
997 	release_sock(sk);
998 	return err;
999 }
1000 
1001 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1002 			       poll_table *wait)
1003 {
1004 	struct sock *sk;
1005 	__poll_t mask;
1006 	struct vsock_sock *vsk;
1007 
1008 	sk = sock->sk;
1009 	vsk = vsock_sk(sk);
1010 
1011 	poll_wait(file, sk_sleep(sk), wait);
1012 	mask = 0;
1013 
1014 	if (sk->sk_err)
1015 		/* Signify that there has been an error on this socket. */
1016 		mask |= EPOLLERR;
1017 
1018 	/* INET sockets treat local write shutdown and peer write shutdown as a
1019 	 * case of EPOLLHUP set.
1020 	 */
1021 	if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1022 	    ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1023 	     (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1024 		mask |= EPOLLHUP;
1025 	}
1026 
1027 	if (sk->sk_shutdown & RCV_SHUTDOWN ||
1028 	    vsk->peer_shutdown & SEND_SHUTDOWN) {
1029 		mask |= EPOLLRDHUP;
1030 	}
1031 
1032 	if (sock->type == SOCK_DGRAM) {
1033 		/* For datagram sockets we can read if there is something in
1034 		 * the queue and write as long as the socket isn't shutdown for
1035 		 * sending.
1036 		 */
1037 		if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1038 		    (sk->sk_shutdown & RCV_SHUTDOWN)) {
1039 			mask |= EPOLLIN | EPOLLRDNORM;
1040 		}
1041 
1042 		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1043 			mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1044 
1045 	} else if (sock_type_connectible(sk->sk_type)) {
1046 		const struct vsock_transport *transport;
1047 
1048 		lock_sock(sk);
1049 
1050 		transport = vsk->transport;
1051 
1052 		/* Listening sockets that have connections in their accept
1053 		 * queue can be read.
1054 		 */
1055 		if (sk->sk_state == TCP_LISTEN
1056 		    && !vsock_is_accept_queue_empty(sk))
1057 			mask |= EPOLLIN | EPOLLRDNORM;
1058 
1059 		/* If there is something in the queue then we can read. */
1060 		if (transport && transport->stream_is_active(vsk) &&
1061 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1062 			bool data_ready_now = false;
1063 			int ret = transport->notify_poll_in(
1064 					vsk, 1, &data_ready_now);
1065 			if (ret < 0) {
1066 				mask |= EPOLLERR;
1067 			} else {
1068 				if (data_ready_now)
1069 					mask |= EPOLLIN | EPOLLRDNORM;
1070 
1071 			}
1072 		}
1073 
1074 		/* Sockets whose connections have been closed, reset, or
1075 		 * terminated should also be considered read, and we check the
1076 		 * shutdown flag for that.
1077 		 */
1078 		if (sk->sk_shutdown & RCV_SHUTDOWN ||
1079 		    vsk->peer_shutdown & SEND_SHUTDOWN) {
1080 			mask |= EPOLLIN | EPOLLRDNORM;
1081 		}
1082 
1083 		/* Connected sockets that can produce data can be written. */
1084 		if (transport && sk->sk_state == TCP_ESTABLISHED) {
1085 			if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1086 				bool space_avail_now = false;
1087 				int ret = transport->notify_poll_out(
1088 						vsk, 1, &space_avail_now);
1089 				if (ret < 0) {
1090 					mask |= EPOLLERR;
1091 				} else {
1092 					if (space_avail_now)
1093 						/* Remove EPOLLWRBAND since INET
1094 						 * sockets are not setting it.
1095 						 */
1096 						mask |= EPOLLOUT | EPOLLWRNORM;
1097 
1098 				}
1099 			}
1100 		}
1101 
1102 		/* Simulate INET socket poll behaviors, which sets
1103 		 * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1104 		 * but local send is not shutdown.
1105 		 */
1106 		if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1107 			if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1108 				mask |= EPOLLOUT | EPOLLWRNORM;
1109 
1110 		}
1111 
1112 		release_sock(sk);
1113 	}
1114 
1115 	return mask;
1116 }
1117 
1118 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1119 			       size_t len)
1120 {
1121 	int err;
1122 	struct sock *sk;
1123 	struct vsock_sock *vsk;
1124 	struct sockaddr_vm *remote_addr;
1125 	const struct vsock_transport *transport;
1126 
1127 	if (msg->msg_flags & MSG_OOB)
1128 		return -EOPNOTSUPP;
1129 
1130 	/* For now, MSG_DONTWAIT is always assumed... */
1131 	err = 0;
1132 	sk = sock->sk;
1133 	vsk = vsock_sk(sk);
1134 
1135 	lock_sock(sk);
1136 
1137 	transport = vsk->transport;
1138 
1139 	err = vsock_auto_bind(vsk);
1140 	if (err)
1141 		goto out;
1142 
1143 
1144 	/* If the provided message contains an address, use that.  Otherwise
1145 	 * fall back on the socket's remote handle (if it has been connected).
1146 	 */
1147 	if (msg->msg_name &&
1148 	    vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1149 			    &remote_addr) == 0) {
1150 		/* Ensure this address is of the right type and is a valid
1151 		 * destination.
1152 		 */
1153 
1154 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1155 			remote_addr->svm_cid = transport->get_local_cid();
1156 
1157 		if (!vsock_addr_bound(remote_addr)) {
1158 			err = -EINVAL;
1159 			goto out;
1160 		}
1161 	} else if (sock->state == SS_CONNECTED) {
1162 		remote_addr = &vsk->remote_addr;
1163 
1164 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1165 			remote_addr->svm_cid = transport->get_local_cid();
1166 
1167 		/* XXX Should connect() or this function ensure remote_addr is
1168 		 * bound?
1169 		 */
1170 		if (!vsock_addr_bound(&vsk->remote_addr)) {
1171 			err = -EINVAL;
1172 			goto out;
1173 		}
1174 	} else {
1175 		err = -EINVAL;
1176 		goto out;
1177 	}
1178 
1179 	if (!transport->dgram_allow(remote_addr->svm_cid,
1180 				    remote_addr->svm_port)) {
1181 		err = -EINVAL;
1182 		goto out;
1183 	}
1184 
1185 	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1186 
1187 out:
1188 	release_sock(sk);
1189 	return err;
1190 }
1191 
1192 static int vsock_dgram_connect(struct socket *sock,
1193 			       struct sockaddr *addr, int addr_len, int flags)
1194 {
1195 	int err;
1196 	struct sock *sk;
1197 	struct vsock_sock *vsk;
1198 	struct sockaddr_vm *remote_addr;
1199 
1200 	sk = sock->sk;
1201 	vsk = vsock_sk(sk);
1202 
1203 	err = vsock_addr_cast(addr, addr_len, &remote_addr);
1204 	if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1205 		lock_sock(sk);
1206 		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1207 				VMADDR_PORT_ANY);
1208 		sock->state = SS_UNCONNECTED;
1209 		release_sock(sk);
1210 		return 0;
1211 	} else if (err != 0)
1212 		return -EINVAL;
1213 
1214 	lock_sock(sk);
1215 
1216 	err = vsock_auto_bind(vsk);
1217 	if (err)
1218 		goto out;
1219 
1220 	if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1221 					 remote_addr->svm_port)) {
1222 		err = -EINVAL;
1223 		goto out;
1224 	}
1225 
1226 	memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1227 	sock->state = SS_CONNECTED;
1228 
1229 out:
1230 	release_sock(sk);
1231 	return err;
1232 }
1233 
1234 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1235 			       size_t len, int flags)
1236 {
1237 	struct vsock_sock *vsk = vsock_sk(sock->sk);
1238 
1239 	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1240 }
1241 
1242 static const struct proto_ops vsock_dgram_ops = {
1243 	.family = PF_VSOCK,
1244 	.owner = THIS_MODULE,
1245 	.release = vsock_release,
1246 	.bind = vsock_bind,
1247 	.connect = vsock_dgram_connect,
1248 	.socketpair = sock_no_socketpair,
1249 	.accept = sock_no_accept,
1250 	.getname = vsock_getname,
1251 	.poll = vsock_poll,
1252 	.ioctl = sock_no_ioctl,
1253 	.listen = sock_no_listen,
1254 	.shutdown = vsock_shutdown,
1255 	.sendmsg = vsock_dgram_sendmsg,
1256 	.recvmsg = vsock_dgram_recvmsg,
1257 	.mmap = sock_no_mmap,
1258 	.sendpage = sock_no_sendpage,
1259 };
1260 
1261 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1262 {
1263 	const struct vsock_transport *transport = vsk->transport;
1264 
1265 	if (!transport || !transport->cancel_pkt)
1266 		return -EOPNOTSUPP;
1267 
1268 	return transport->cancel_pkt(vsk);
1269 }
1270 
1271 static void vsock_connect_timeout(struct work_struct *work)
1272 {
1273 	struct sock *sk;
1274 	struct vsock_sock *vsk;
1275 
1276 	vsk = container_of(work, struct vsock_sock, connect_work.work);
1277 	sk = sk_vsock(vsk);
1278 
1279 	lock_sock(sk);
1280 	if (sk->sk_state == TCP_SYN_SENT &&
1281 	    (sk->sk_shutdown != SHUTDOWN_MASK)) {
1282 		sk->sk_state = TCP_CLOSE;
1283 		sk->sk_err = ETIMEDOUT;
1284 		sk_error_report(sk);
1285 		vsock_transport_cancel_pkt(vsk);
1286 	}
1287 	release_sock(sk);
1288 
1289 	sock_put(sk);
1290 }
1291 
1292 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1293 			 int addr_len, int flags)
1294 {
1295 	int err;
1296 	struct sock *sk;
1297 	struct vsock_sock *vsk;
1298 	const struct vsock_transport *transport;
1299 	struct sockaddr_vm *remote_addr;
1300 	long timeout;
1301 	DEFINE_WAIT(wait);
1302 
1303 	err = 0;
1304 	sk = sock->sk;
1305 	vsk = vsock_sk(sk);
1306 
1307 	lock_sock(sk);
1308 
1309 	/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1310 	switch (sock->state) {
1311 	case SS_CONNECTED:
1312 		err = -EISCONN;
1313 		goto out;
1314 	case SS_DISCONNECTING:
1315 		err = -EINVAL;
1316 		goto out;
1317 	case SS_CONNECTING:
1318 		/* This continues on so we can move sock into the SS_CONNECTED
1319 		 * state once the connection has completed (at which point err
1320 		 * will be set to zero also).  Otherwise, we will either wait
1321 		 * for the connection or return -EALREADY should this be a
1322 		 * non-blocking call.
1323 		 */
1324 		err = -EALREADY;
1325 		break;
1326 	default:
1327 		if ((sk->sk_state == TCP_LISTEN) ||
1328 		    vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1329 			err = -EINVAL;
1330 			goto out;
1331 		}
1332 
1333 		/* Set the remote address that we are connecting to. */
1334 		memcpy(&vsk->remote_addr, remote_addr,
1335 		       sizeof(vsk->remote_addr));
1336 
1337 		err = vsock_assign_transport(vsk, NULL);
1338 		if (err)
1339 			goto out;
1340 
1341 		transport = vsk->transport;
1342 
1343 		/* The hypervisor and well-known contexts do not have socket
1344 		 * endpoints.
1345 		 */
1346 		if (!transport ||
1347 		    !transport->stream_allow(remote_addr->svm_cid,
1348 					     remote_addr->svm_port)) {
1349 			err = -ENETUNREACH;
1350 			goto out;
1351 		}
1352 
1353 		err = vsock_auto_bind(vsk);
1354 		if (err)
1355 			goto out;
1356 
1357 		sk->sk_state = TCP_SYN_SENT;
1358 
1359 		err = transport->connect(vsk);
1360 		if (err < 0)
1361 			goto out;
1362 
1363 		/* Mark sock as connecting and set the error code to in
1364 		 * progress in case this is a non-blocking connect.
1365 		 */
1366 		sock->state = SS_CONNECTING;
1367 		err = -EINPROGRESS;
1368 	}
1369 
1370 	/* The receive path will handle all communication until we are able to
1371 	 * enter the connected state.  Here we wait for the connection to be
1372 	 * completed or a notification of an error.
1373 	 */
1374 	timeout = vsk->connect_timeout;
1375 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1376 
1377 	while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1378 		if (flags & O_NONBLOCK) {
1379 			/* If we're not going to block, we schedule a timeout
1380 			 * function to generate a timeout on the connection
1381 			 * attempt, in case the peer doesn't respond in a
1382 			 * timely manner. We hold on to the socket until the
1383 			 * timeout fires.
1384 			 */
1385 			sock_hold(sk);
1386 			schedule_delayed_work(&vsk->connect_work, timeout);
1387 
1388 			/* Skip ahead to preserve error code set above. */
1389 			goto out_wait;
1390 		}
1391 
1392 		release_sock(sk);
1393 		timeout = schedule_timeout(timeout);
1394 		lock_sock(sk);
1395 
1396 		if (signal_pending(current)) {
1397 			err = sock_intr_errno(timeout);
1398 			sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1399 			sock->state = SS_UNCONNECTED;
1400 			vsock_transport_cancel_pkt(vsk);
1401 			goto out_wait;
1402 		} else if (timeout == 0) {
1403 			err = -ETIMEDOUT;
1404 			sk->sk_state = TCP_CLOSE;
1405 			sock->state = SS_UNCONNECTED;
1406 			vsock_transport_cancel_pkt(vsk);
1407 			goto out_wait;
1408 		}
1409 
1410 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1411 	}
1412 
1413 	if (sk->sk_err) {
1414 		err = -sk->sk_err;
1415 		sk->sk_state = TCP_CLOSE;
1416 		sock->state = SS_UNCONNECTED;
1417 	} else {
1418 		err = 0;
1419 	}
1420 
1421 out_wait:
1422 	finish_wait(sk_sleep(sk), &wait);
1423 out:
1424 	release_sock(sk);
1425 	return err;
1426 }
1427 
1428 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1429 			bool kern)
1430 {
1431 	struct sock *listener;
1432 	int err;
1433 	struct sock *connected;
1434 	struct vsock_sock *vconnected;
1435 	long timeout;
1436 	DEFINE_WAIT(wait);
1437 
1438 	err = 0;
1439 	listener = sock->sk;
1440 
1441 	lock_sock(listener);
1442 
1443 	if (!sock_type_connectible(sock->type)) {
1444 		err = -EOPNOTSUPP;
1445 		goto out;
1446 	}
1447 
1448 	if (listener->sk_state != TCP_LISTEN) {
1449 		err = -EINVAL;
1450 		goto out;
1451 	}
1452 
1453 	/* Wait for children sockets to appear; these are the new sockets
1454 	 * created upon connection establishment.
1455 	 */
1456 	timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1457 	prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1458 
1459 	while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1460 	       listener->sk_err == 0) {
1461 		release_sock(listener);
1462 		timeout = schedule_timeout(timeout);
1463 		finish_wait(sk_sleep(listener), &wait);
1464 		lock_sock(listener);
1465 
1466 		if (signal_pending(current)) {
1467 			err = sock_intr_errno(timeout);
1468 			goto out;
1469 		} else if (timeout == 0) {
1470 			err = -EAGAIN;
1471 			goto out;
1472 		}
1473 
1474 		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1475 	}
1476 	finish_wait(sk_sleep(listener), &wait);
1477 
1478 	if (listener->sk_err)
1479 		err = -listener->sk_err;
1480 
1481 	if (connected) {
1482 		sk_acceptq_removed(listener);
1483 
1484 		lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1485 		vconnected = vsock_sk(connected);
1486 
1487 		/* If the listener socket has received an error, then we should
1488 		 * reject this socket and return.  Note that we simply mark the
1489 		 * socket rejected, drop our reference, and let the cleanup
1490 		 * function handle the cleanup; the fact that we found it in
1491 		 * the listener's accept queue guarantees that the cleanup
1492 		 * function hasn't run yet.
1493 		 */
1494 		if (err) {
1495 			vconnected->rejected = true;
1496 		} else {
1497 			newsock->state = SS_CONNECTED;
1498 			sock_graft(connected, newsock);
1499 		}
1500 
1501 		release_sock(connected);
1502 		sock_put(connected);
1503 	}
1504 
1505 out:
1506 	release_sock(listener);
1507 	return err;
1508 }
1509 
1510 static int vsock_listen(struct socket *sock, int backlog)
1511 {
1512 	int err;
1513 	struct sock *sk;
1514 	struct vsock_sock *vsk;
1515 
1516 	sk = sock->sk;
1517 
1518 	lock_sock(sk);
1519 
1520 	if (!sock_type_connectible(sk->sk_type)) {
1521 		err = -EOPNOTSUPP;
1522 		goto out;
1523 	}
1524 
1525 	if (sock->state != SS_UNCONNECTED) {
1526 		err = -EINVAL;
1527 		goto out;
1528 	}
1529 
1530 	vsk = vsock_sk(sk);
1531 
1532 	if (!vsock_addr_bound(&vsk->local_addr)) {
1533 		err = -EINVAL;
1534 		goto out;
1535 	}
1536 
1537 	sk->sk_max_ack_backlog = backlog;
1538 	sk->sk_state = TCP_LISTEN;
1539 
1540 	err = 0;
1541 
1542 out:
1543 	release_sock(sk);
1544 	return err;
1545 }
1546 
1547 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1548 				     const struct vsock_transport *transport,
1549 				     u64 val)
1550 {
1551 	if (val > vsk->buffer_max_size)
1552 		val = vsk->buffer_max_size;
1553 
1554 	if (val < vsk->buffer_min_size)
1555 		val = vsk->buffer_min_size;
1556 
1557 	if (val != vsk->buffer_size &&
1558 	    transport && transport->notify_buffer_size)
1559 		transport->notify_buffer_size(vsk, &val);
1560 
1561 	vsk->buffer_size = val;
1562 }
1563 
1564 static int vsock_connectible_setsockopt(struct socket *sock,
1565 					int level,
1566 					int optname,
1567 					sockptr_t optval,
1568 					unsigned int optlen)
1569 {
1570 	int err;
1571 	struct sock *sk;
1572 	struct vsock_sock *vsk;
1573 	const struct vsock_transport *transport;
1574 	u64 val;
1575 
1576 	if (level != AF_VSOCK)
1577 		return -ENOPROTOOPT;
1578 
1579 #define COPY_IN(_v)                                       \
1580 	do {						  \
1581 		if (optlen < sizeof(_v)) {		  \
1582 			err = -EINVAL;			  \
1583 			goto exit;			  \
1584 		}					  \
1585 		if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {	\
1586 			err = -EFAULT;					\
1587 			goto exit;					\
1588 		}							\
1589 	} while (0)
1590 
1591 	err = 0;
1592 	sk = sock->sk;
1593 	vsk = vsock_sk(sk);
1594 
1595 	lock_sock(sk);
1596 
1597 	transport = vsk->transport;
1598 
1599 	switch (optname) {
1600 	case SO_VM_SOCKETS_BUFFER_SIZE:
1601 		COPY_IN(val);
1602 		vsock_update_buffer_size(vsk, transport, val);
1603 		break;
1604 
1605 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1606 		COPY_IN(val);
1607 		vsk->buffer_max_size = val;
1608 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1609 		break;
1610 
1611 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1612 		COPY_IN(val);
1613 		vsk->buffer_min_size = val;
1614 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1615 		break;
1616 
1617 	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1618 		struct __kernel_old_timeval tv;
1619 		COPY_IN(tv);
1620 		if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1621 		    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1622 			vsk->connect_timeout = tv.tv_sec * HZ +
1623 			    DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1624 			if (vsk->connect_timeout == 0)
1625 				vsk->connect_timeout =
1626 				    VSOCK_DEFAULT_CONNECT_TIMEOUT;
1627 
1628 		} else {
1629 			err = -ERANGE;
1630 		}
1631 		break;
1632 	}
1633 
1634 	default:
1635 		err = -ENOPROTOOPT;
1636 		break;
1637 	}
1638 
1639 #undef COPY_IN
1640 
1641 exit:
1642 	release_sock(sk);
1643 	return err;
1644 }
1645 
1646 static int vsock_connectible_getsockopt(struct socket *sock,
1647 					int level, int optname,
1648 					char __user *optval,
1649 					int __user *optlen)
1650 {
1651 	int err;
1652 	int len;
1653 	struct sock *sk;
1654 	struct vsock_sock *vsk;
1655 	u64 val;
1656 
1657 	if (level != AF_VSOCK)
1658 		return -ENOPROTOOPT;
1659 
1660 	err = get_user(len, optlen);
1661 	if (err != 0)
1662 		return err;
1663 
1664 #define COPY_OUT(_v)                            \
1665 	do {					\
1666 		if (len < sizeof(_v))		\
1667 			return -EINVAL;		\
1668 						\
1669 		len = sizeof(_v);		\
1670 		if (copy_to_user(optval, &_v, len) != 0)	\
1671 			return -EFAULT;				\
1672 								\
1673 	} while (0)
1674 
1675 	err = 0;
1676 	sk = sock->sk;
1677 	vsk = vsock_sk(sk);
1678 
1679 	switch (optname) {
1680 	case SO_VM_SOCKETS_BUFFER_SIZE:
1681 		val = vsk->buffer_size;
1682 		COPY_OUT(val);
1683 		break;
1684 
1685 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1686 		val = vsk->buffer_max_size;
1687 		COPY_OUT(val);
1688 		break;
1689 
1690 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1691 		val = vsk->buffer_min_size;
1692 		COPY_OUT(val);
1693 		break;
1694 
1695 	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1696 		struct __kernel_old_timeval tv;
1697 		tv.tv_sec = vsk->connect_timeout / HZ;
1698 		tv.tv_usec =
1699 		    (vsk->connect_timeout -
1700 		     tv.tv_sec * HZ) * (1000000 / HZ);
1701 		COPY_OUT(tv);
1702 		break;
1703 	}
1704 	default:
1705 		return -ENOPROTOOPT;
1706 	}
1707 
1708 	err = put_user(len, optlen);
1709 	if (err != 0)
1710 		return -EFAULT;
1711 
1712 #undef COPY_OUT
1713 
1714 	return 0;
1715 }
1716 
1717 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1718 				     size_t len)
1719 {
1720 	struct sock *sk;
1721 	struct vsock_sock *vsk;
1722 	const struct vsock_transport *transport;
1723 	ssize_t total_written;
1724 	long timeout;
1725 	int err;
1726 	struct vsock_transport_send_notify_data send_data;
1727 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1728 
1729 	sk = sock->sk;
1730 	vsk = vsock_sk(sk);
1731 	total_written = 0;
1732 	err = 0;
1733 
1734 	if (msg->msg_flags & MSG_OOB)
1735 		return -EOPNOTSUPP;
1736 
1737 	lock_sock(sk);
1738 
1739 	transport = vsk->transport;
1740 
1741 	/* Callers should not provide a destination with connection oriented
1742 	 * sockets.
1743 	 */
1744 	if (msg->msg_namelen) {
1745 		err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1746 		goto out;
1747 	}
1748 
1749 	/* Send data only if both sides are not shutdown in the direction. */
1750 	if (sk->sk_shutdown & SEND_SHUTDOWN ||
1751 	    vsk->peer_shutdown & RCV_SHUTDOWN) {
1752 		err = -EPIPE;
1753 		goto out;
1754 	}
1755 
1756 	if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1757 	    !vsock_addr_bound(&vsk->local_addr)) {
1758 		err = -ENOTCONN;
1759 		goto out;
1760 	}
1761 
1762 	if (!vsock_addr_bound(&vsk->remote_addr)) {
1763 		err = -EDESTADDRREQ;
1764 		goto out;
1765 	}
1766 
1767 	/* Wait for room in the produce queue to enqueue our user's data. */
1768 	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1769 
1770 	err = transport->notify_send_init(vsk, &send_data);
1771 	if (err < 0)
1772 		goto out;
1773 
1774 	while (total_written < len) {
1775 		ssize_t written;
1776 
1777 		add_wait_queue(sk_sleep(sk), &wait);
1778 		while (vsock_stream_has_space(vsk) == 0 &&
1779 		       sk->sk_err == 0 &&
1780 		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1781 		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1782 
1783 			/* Don't wait for non-blocking sockets. */
1784 			if (timeout == 0) {
1785 				err = -EAGAIN;
1786 				remove_wait_queue(sk_sleep(sk), &wait);
1787 				goto out_err;
1788 			}
1789 
1790 			err = transport->notify_send_pre_block(vsk, &send_data);
1791 			if (err < 0) {
1792 				remove_wait_queue(sk_sleep(sk), &wait);
1793 				goto out_err;
1794 			}
1795 
1796 			release_sock(sk);
1797 			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1798 			lock_sock(sk);
1799 			if (signal_pending(current)) {
1800 				err = sock_intr_errno(timeout);
1801 				remove_wait_queue(sk_sleep(sk), &wait);
1802 				goto out_err;
1803 			} else if (timeout == 0) {
1804 				err = -EAGAIN;
1805 				remove_wait_queue(sk_sleep(sk), &wait);
1806 				goto out_err;
1807 			}
1808 		}
1809 		remove_wait_queue(sk_sleep(sk), &wait);
1810 
1811 		/* These checks occur both as part of and after the loop
1812 		 * conditional since we need to check before and after
1813 		 * sleeping.
1814 		 */
1815 		if (sk->sk_err) {
1816 			err = -sk->sk_err;
1817 			goto out_err;
1818 		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1819 			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1820 			err = -EPIPE;
1821 			goto out_err;
1822 		}
1823 
1824 		err = transport->notify_send_pre_enqueue(vsk, &send_data);
1825 		if (err < 0)
1826 			goto out_err;
1827 
1828 		/* Note that enqueue will only write as many bytes as are free
1829 		 * in the produce queue, so we don't need to ensure len is
1830 		 * smaller than the queue size.  It is the caller's
1831 		 * responsibility to check how many bytes we were able to send.
1832 		 */
1833 
1834 		if (sk->sk_type == SOCK_SEQPACKET) {
1835 			written = transport->seqpacket_enqueue(vsk,
1836 						msg, len - total_written);
1837 		} else {
1838 			written = transport->stream_enqueue(vsk,
1839 					msg, len - total_written);
1840 		}
1841 		if (written < 0) {
1842 			err = -ENOMEM;
1843 			goto out_err;
1844 		}
1845 
1846 		total_written += written;
1847 
1848 		err = transport->notify_send_post_enqueue(
1849 				vsk, written, &send_data);
1850 		if (err < 0)
1851 			goto out_err;
1852 
1853 	}
1854 
1855 out_err:
1856 	if (total_written > 0) {
1857 		/* Return number of written bytes only if:
1858 		 * 1) SOCK_STREAM socket.
1859 		 * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1860 		 */
1861 		if (sk->sk_type == SOCK_STREAM || total_written == len)
1862 			err = total_written;
1863 	}
1864 out:
1865 	release_sock(sk);
1866 	return err;
1867 }
1868 
1869 static int vsock_connectible_wait_data(struct sock *sk,
1870 				       struct wait_queue_entry *wait,
1871 				       long timeout,
1872 				       struct vsock_transport_recv_notify_data *recv_data,
1873 				       size_t target)
1874 {
1875 	const struct vsock_transport *transport;
1876 	struct vsock_sock *vsk;
1877 	s64 data;
1878 	int err;
1879 
1880 	vsk = vsock_sk(sk);
1881 	err = 0;
1882 	transport = vsk->transport;
1883 
1884 	while ((data = vsock_connectible_has_data(vsk)) == 0) {
1885 		prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1886 
1887 		if (sk->sk_err != 0 ||
1888 		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
1889 		    (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1890 			break;
1891 		}
1892 
1893 		/* Don't wait for non-blocking sockets. */
1894 		if (timeout == 0) {
1895 			err = -EAGAIN;
1896 			break;
1897 		}
1898 
1899 		if (recv_data) {
1900 			err = transport->notify_recv_pre_block(vsk, target, recv_data);
1901 			if (err < 0)
1902 				break;
1903 		}
1904 
1905 		release_sock(sk);
1906 		timeout = schedule_timeout(timeout);
1907 		lock_sock(sk);
1908 
1909 		if (signal_pending(current)) {
1910 			err = sock_intr_errno(timeout);
1911 			break;
1912 		} else if (timeout == 0) {
1913 			err = -EAGAIN;
1914 			break;
1915 		}
1916 	}
1917 
1918 	finish_wait(sk_sleep(sk), wait);
1919 
1920 	if (err)
1921 		return err;
1922 
1923 	/* Internal transport error when checking for available
1924 	 * data. XXX This should be changed to a connection
1925 	 * reset in a later change.
1926 	 */
1927 	if (data < 0)
1928 		return -ENOMEM;
1929 
1930 	return data;
1931 }
1932 
1933 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1934 				  size_t len, int flags)
1935 {
1936 	struct vsock_transport_recv_notify_data recv_data;
1937 	const struct vsock_transport *transport;
1938 	struct vsock_sock *vsk;
1939 	ssize_t copied;
1940 	size_t target;
1941 	long timeout;
1942 	int err;
1943 
1944 	DEFINE_WAIT(wait);
1945 
1946 	vsk = vsock_sk(sk);
1947 	transport = vsk->transport;
1948 
1949 	/* We must not copy less than target bytes into the user's buffer
1950 	 * before returning successfully, so we wait for the consume queue to
1951 	 * have that much data to consume before dequeueing.  Note that this
1952 	 * makes it impossible to handle cases where target is greater than the
1953 	 * queue size.
1954 	 */
1955 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1956 	if (target >= transport->stream_rcvhiwat(vsk)) {
1957 		err = -ENOMEM;
1958 		goto out;
1959 	}
1960 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1961 	copied = 0;
1962 
1963 	err = transport->notify_recv_init(vsk, target, &recv_data);
1964 	if (err < 0)
1965 		goto out;
1966 
1967 
1968 	while (1) {
1969 		ssize_t read;
1970 
1971 		err = vsock_connectible_wait_data(sk, &wait, timeout,
1972 						  &recv_data, target);
1973 		if (err <= 0)
1974 			break;
1975 
1976 		err = transport->notify_recv_pre_dequeue(vsk, target,
1977 							 &recv_data);
1978 		if (err < 0)
1979 			break;
1980 
1981 		read = transport->stream_dequeue(vsk, msg, len - copied, flags);
1982 		if (read < 0) {
1983 			err = -ENOMEM;
1984 			break;
1985 		}
1986 
1987 		copied += read;
1988 
1989 		err = transport->notify_recv_post_dequeue(vsk, target, read,
1990 						!(flags & MSG_PEEK), &recv_data);
1991 		if (err < 0)
1992 			goto out;
1993 
1994 		if (read >= target || flags & MSG_PEEK)
1995 			break;
1996 
1997 		target -= read;
1998 	}
1999 
2000 	if (sk->sk_err)
2001 		err = -sk->sk_err;
2002 	else if (sk->sk_shutdown & RCV_SHUTDOWN)
2003 		err = 0;
2004 
2005 	if (copied > 0)
2006 		err = copied;
2007 
2008 out:
2009 	return err;
2010 }
2011 
2012 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2013 				     size_t len, int flags)
2014 {
2015 	const struct vsock_transport *transport;
2016 	struct vsock_sock *vsk;
2017 	ssize_t msg_len;
2018 	long timeout;
2019 	int err = 0;
2020 	DEFINE_WAIT(wait);
2021 
2022 	vsk = vsock_sk(sk);
2023 	transport = vsk->transport;
2024 
2025 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2026 
2027 	err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2028 	if (err <= 0)
2029 		goto out;
2030 
2031 	msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2032 
2033 	if (msg_len < 0) {
2034 		err = -ENOMEM;
2035 		goto out;
2036 	}
2037 
2038 	if (sk->sk_err) {
2039 		err = -sk->sk_err;
2040 	} else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2041 		err = 0;
2042 	} else {
2043 		/* User sets MSG_TRUNC, so return real length of
2044 		 * packet.
2045 		 */
2046 		if (flags & MSG_TRUNC)
2047 			err = msg_len;
2048 		else
2049 			err = len - msg_data_left(msg);
2050 
2051 		/* Always set MSG_TRUNC if real length of packet is
2052 		 * bigger than user's buffer.
2053 		 */
2054 		if (msg_len > len)
2055 			msg->msg_flags |= MSG_TRUNC;
2056 	}
2057 
2058 out:
2059 	return err;
2060 }
2061 
2062 static int
2063 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2064 			  int flags)
2065 {
2066 	struct sock *sk;
2067 	struct vsock_sock *vsk;
2068 	const struct vsock_transport *transport;
2069 	int err;
2070 
2071 	DEFINE_WAIT(wait);
2072 
2073 	sk = sock->sk;
2074 	vsk = vsock_sk(sk);
2075 	err = 0;
2076 
2077 	lock_sock(sk);
2078 
2079 	transport = vsk->transport;
2080 
2081 	if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2082 		/* Recvmsg is supposed to return 0 if a peer performs an
2083 		 * orderly shutdown. Differentiate between that case and when a
2084 		 * peer has not connected or a local shutdown occurred with the
2085 		 * SOCK_DONE flag.
2086 		 */
2087 		if (sock_flag(sk, SOCK_DONE))
2088 			err = 0;
2089 		else
2090 			err = -ENOTCONN;
2091 
2092 		goto out;
2093 	}
2094 
2095 	if (flags & MSG_OOB) {
2096 		err = -EOPNOTSUPP;
2097 		goto out;
2098 	}
2099 
2100 	/* We don't check peer_shutdown flag here since peer may actually shut
2101 	 * down, but there can be data in the queue that a local socket can
2102 	 * receive.
2103 	 */
2104 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2105 		err = 0;
2106 		goto out;
2107 	}
2108 
2109 	/* It is valid on Linux to pass in a zero-length receive buffer.  This
2110 	 * is not an error.  We may as well bail out now.
2111 	 */
2112 	if (!len) {
2113 		err = 0;
2114 		goto out;
2115 	}
2116 
2117 	if (sk->sk_type == SOCK_STREAM)
2118 		err = __vsock_stream_recvmsg(sk, msg, len, flags);
2119 	else
2120 		err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2121 
2122 out:
2123 	release_sock(sk);
2124 	return err;
2125 }
2126 
2127 static const struct proto_ops vsock_stream_ops = {
2128 	.family = PF_VSOCK,
2129 	.owner = THIS_MODULE,
2130 	.release = vsock_release,
2131 	.bind = vsock_bind,
2132 	.connect = vsock_connect,
2133 	.socketpair = sock_no_socketpair,
2134 	.accept = vsock_accept,
2135 	.getname = vsock_getname,
2136 	.poll = vsock_poll,
2137 	.ioctl = sock_no_ioctl,
2138 	.listen = vsock_listen,
2139 	.shutdown = vsock_shutdown,
2140 	.setsockopt = vsock_connectible_setsockopt,
2141 	.getsockopt = vsock_connectible_getsockopt,
2142 	.sendmsg = vsock_connectible_sendmsg,
2143 	.recvmsg = vsock_connectible_recvmsg,
2144 	.mmap = sock_no_mmap,
2145 	.sendpage = sock_no_sendpage,
2146 };
2147 
2148 static const struct proto_ops vsock_seqpacket_ops = {
2149 	.family = PF_VSOCK,
2150 	.owner = THIS_MODULE,
2151 	.release = vsock_release,
2152 	.bind = vsock_bind,
2153 	.connect = vsock_connect,
2154 	.socketpair = sock_no_socketpair,
2155 	.accept = vsock_accept,
2156 	.getname = vsock_getname,
2157 	.poll = vsock_poll,
2158 	.ioctl = sock_no_ioctl,
2159 	.listen = vsock_listen,
2160 	.shutdown = vsock_shutdown,
2161 	.setsockopt = vsock_connectible_setsockopt,
2162 	.getsockopt = vsock_connectible_getsockopt,
2163 	.sendmsg = vsock_connectible_sendmsg,
2164 	.recvmsg = vsock_connectible_recvmsg,
2165 	.mmap = sock_no_mmap,
2166 	.sendpage = sock_no_sendpage,
2167 };
2168 
2169 static int vsock_create(struct net *net, struct socket *sock,
2170 			int protocol, int kern)
2171 {
2172 	struct vsock_sock *vsk;
2173 	struct sock *sk;
2174 	int ret;
2175 
2176 	if (!sock)
2177 		return -EINVAL;
2178 
2179 	if (protocol && protocol != PF_VSOCK)
2180 		return -EPROTONOSUPPORT;
2181 
2182 	switch (sock->type) {
2183 	case SOCK_DGRAM:
2184 		sock->ops = &vsock_dgram_ops;
2185 		break;
2186 	case SOCK_STREAM:
2187 		sock->ops = &vsock_stream_ops;
2188 		break;
2189 	case SOCK_SEQPACKET:
2190 		sock->ops = &vsock_seqpacket_ops;
2191 		break;
2192 	default:
2193 		return -ESOCKTNOSUPPORT;
2194 	}
2195 
2196 	sock->state = SS_UNCONNECTED;
2197 
2198 	sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2199 	if (!sk)
2200 		return -ENOMEM;
2201 
2202 	vsk = vsock_sk(sk);
2203 
2204 	if (sock->type == SOCK_DGRAM) {
2205 		ret = vsock_assign_transport(vsk, NULL);
2206 		if (ret < 0) {
2207 			sock_put(sk);
2208 			return ret;
2209 		}
2210 	}
2211 
2212 	vsock_insert_unbound(vsk);
2213 
2214 	return 0;
2215 }
2216 
2217 static const struct net_proto_family vsock_family_ops = {
2218 	.family = AF_VSOCK,
2219 	.create = vsock_create,
2220 	.owner = THIS_MODULE,
2221 };
2222 
2223 static long vsock_dev_do_ioctl(struct file *filp,
2224 			       unsigned int cmd, void __user *ptr)
2225 {
2226 	u32 __user *p = ptr;
2227 	u32 cid = VMADDR_CID_ANY;
2228 	int retval = 0;
2229 
2230 	switch (cmd) {
2231 	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2232 		/* To be compatible with the VMCI behavior, we prioritize the
2233 		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2234 		 */
2235 		if (transport_g2h)
2236 			cid = transport_g2h->get_local_cid();
2237 		else if (transport_h2g)
2238 			cid = transport_h2g->get_local_cid();
2239 
2240 		if (put_user(cid, p) != 0)
2241 			retval = -EFAULT;
2242 		break;
2243 
2244 	default:
2245 		retval = -ENOIOCTLCMD;
2246 	}
2247 
2248 	return retval;
2249 }
2250 
2251 static long vsock_dev_ioctl(struct file *filp,
2252 			    unsigned int cmd, unsigned long arg)
2253 {
2254 	return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2255 }
2256 
2257 #ifdef CONFIG_COMPAT
2258 static long vsock_dev_compat_ioctl(struct file *filp,
2259 				   unsigned int cmd, unsigned long arg)
2260 {
2261 	return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2262 }
2263 #endif
2264 
2265 static const struct file_operations vsock_device_ops = {
2266 	.owner		= THIS_MODULE,
2267 	.unlocked_ioctl	= vsock_dev_ioctl,
2268 #ifdef CONFIG_COMPAT
2269 	.compat_ioctl	= vsock_dev_compat_ioctl,
2270 #endif
2271 	.open		= nonseekable_open,
2272 };
2273 
2274 static struct miscdevice vsock_device = {
2275 	.name		= "vsock",
2276 	.fops		= &vsock_device_ops,
2277 };
2278 
2279 static int __init vsock_init(void)
2280 {
2281 	int err = 0;
2282 
2283 	vsock_init_tables();
2284 
2285 	vsock_proto.owner = THIS_MODULE;
2286 	vsock_device.minor = MISC_DYNAMIC_MINOR;
2287 	err = misc_register(&vsock_device);
2288 	if (err) {
2289 		pr_err("Failed to register misc device\n");
2290 		goto err_reset_transport;
2291 	}
2292 
2293 	err = proto_register(&vsock_proto, 1);	/* we want our slab */
2294 	if (err) {
2295 		pr_err("Cannot register vsock protocol\n");
2296 		goto err_deregister_misc;
2297 	}
2298 
2299 	err = sock_register(&vsock_family_ops);
2300 	if (err) {
2301 		pr_err("could not register af_vsock (%d) address family: %d\n",
2302 		       AF_VSOCK, err);
2303 		goto err_unregister_proto;
2304 	}
2305 
2306 	return 0;
2307 
2308 err_unregister_proto:
2309 	proto_unregister(&vsock_proto);
2310 err_deregister_misc:
2311 	misc_deregister(&vsock_device);
2312 err_reset_transport:
2313 	return err;
2314 }
2315 
2316 static void __exit vsock_exit(void)
2317 {
2318 	misc_deregister(&vsock_device);
2319 	sock_unregister(AF_VSOCK);
2320 	proto_unregister(&vsock_proto);
2321 }
2322 
2323 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2324 {
2325 	return vsk->transport;
2326 }
2327 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2328 
2329 int vsock_core_register(const struct vsock_transport *t, int features)
2330 {
2331 	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2332 	int err = mutex_lock_interruptible(&vsock_register_mutex);
2333 
2334 	if (err)
2335 		return err;
2336 
2337 	t_h2g = transport_h2g;
2338 	t_g2h = transport_g2h;
2339 	t_dgram = transport_dgram;
2340 	t_local = transport_local;
2341 
2342 	if (features & VSOCK_TRANSPORT_F_H2G) {
2343 		if (t_h2g) {
2344 			err = -EBUSY;
2345 			goto err_busy;
2346 		}
2347 		t_h2g = t;
2348 	}
2349 
2350 	if (features & VSOCK_TRANSPORT_F_G2H) {
2351 		if (t_g2h) {
2352 			err = -EBUSY;
2353 			goto err_busy;
2354 		}
2355 		t_g2h = t;
2356 	}
2357 
2358 	if (features & VSOCK_TRANSPORT_F_DGRAM) {
2359 		if (t_dgram) {
2360 			err = -EBUSY;
2361 			goto err_busy;
2362 		}
2363 		t_dgram = t;
2364 	}
2365 
2366 	if (features & VSOCK_TRANSPORT_F_LOCAL) {
2367 		if (t_local) {
2368 			err = -EBUSY;
2369 			goto err_busy;
2370 		}
2371 		t_local = t;
2372 	}
2373 
2374 	transport_h2g = t_h2g;
2375 	transport_g2h = t_g2h;
2376 	transport_dgram = t_dgram;
2377 	transport_local = t_local;
2378 
2379 err_busy:
2380 	mutex_unlock(&vsock_register_mutex);
2381 	return err;
2382 }
2383 EXPORT_SYMBOL_GPL(vsock_core_register);
2384 
2385 void vsock_core_unregister(const struct vsock_transport *t)
2386 {
2387 	mutex_lock(&vsock_register_mutex);
2388 
2389 	if (transport_h2g == t)
2390 		transport_h2g = NULL;
2391 
2392 	if (transport_g2h == t)
2393 		transport_g2h = NULL;
2394 
2395 	if (transport_dgram == t)
2396 		transport_dgram = NULL;
2397 
2398 	if (transport_local == t)
2399 		transport_local = NULL;
2400 
2401 	mutex_unlock(&vsock_register_mutex);
2402 }
2403 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2404 
2405 module_init(vsock_init);
2406 module_exit(vsock_exit);
2407 
2408 MODULE_AUTHOR("VMware, Inc.");
2409 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2410 MODULE_VERSION("1.0.2.0-k");
2411 MODULE_LICENSE("GPL v2");
2412