xref: /openbmc/linux/net/vmw_vsock/af_vsock.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VMware vSockets Driver
4  *
5  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
6  */
7 
8 /* Implementation notes:
9  *
10  * - There are two kinds of sockets: those created by user action (such as
11  * calling socket(2)) and those created by incoming connection request packets.
12  *
13  * - There are two "global" tables, one for bound sockets (sockets that have
14  * specified an address that they are responsible for) and one for connected
15  * sockets (sockets that have established a connection with another socket).
16  * These tables are "global" in that all sockets on the system are placed
17  * within them. - Note, though, that the bound table contains an extra entry
18  * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
19  * that list. The bound table is used solely for lookup of sockets when packets
20  * are received and that's not necessary for SOCK_DGRAM sockets since we create
21  * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
22  * sockets out of the bound hash buckets will reduce the chance of collisions
23  * when looking for SOCK_STREAM sockets and prevents us from having to check the
24  * socket type in the hash table lookups.
25  *
26  * - Sockets created by user action will either be "client" sockets that
27  * initiate a connection or "server" sockets that listen for connections; we do
28  * not support simultaneous connects (two "client" sockets connecting).
29  *
30  * - "Server" sockets are referred to as listener sockets throughout this
31  * implementation because they are in the TCP_LISTEN state.  When a
32  * connection request is received (the second kind of socket mentioned above),
33  * we create a new socket and refer to it as a pending socket.  These pending
34  * sockets are placed on the pending connection list of the listener socket.
35  * When future packets are received for the address the listener socket is
36  * bound to, we check if the source of the packet is from one that has an
37  * existing pending connection.  If it does, we process the packet for the
38  * pending socket.  When that socket reaches the connected state, it is removed
39  * from the listener socket's pending list and enqueued in the listener
40  * socket's accept queue.  Callers of accept(2) will accept connected sockets
41  * from the listener socket's accept queue.  If the socket cannot be accepted
42  * for some reason then it is marked rejected.  Once the connection is
43  * accepted, it is owned by the user process and the responsibility for cleanup
44  * falls with that user process.
45  *
46  * - It is possible that these pending sockets will never reach the connected
47  * state; in fact, we may never receive another packet after the connection
48  * request.  Because of this, we must schedule a cleanup function to run in the
49  * future, after some amount of time passes where a connection should have been
50  * established.  This function ensures that the socket is off all lists so it
51  * cannot be retrieved, then drops all references to the socket so it is cleaned
52  * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
53  * function will also cleanup rejected sockets, those that reach the connected
54  * state but leave it before they have been accepted.
55  *
56  * - Lock ordering for pending or accept queue sockets is:
57  *
58  *     lock_sock(listener);
59  *     lock_sock_nested(pending, SINGLE_DEPTH_NESTING);
60  *
61  * Using explicit nested locking keeps lockdep happy since normally only one
62  * lock of a given class may be taken at a time.
63  *
64  * - Sockets created by user action will be cleaned up when the user process
65  * calls close(2), causing our release implementation to be called. Our release
66  * implementation will perform some cleanup then drop the last reference so our
67  * sk_destruct implementation is invoked.  Our sk_destruct implementation will
68  * perform additional cleanup that's common for both types of sockets.
69  *
70  * - A socket's reference count is what ensures that the structure won't be
71  * freed.  Each entry in a list (such as the "global" bound and connected tables
72  * and the listener socket's pending list and connected queue) ensures a
73  * reference.  When we defer work until process context and pass a socket as our
74  * argument, we must ensure the reference count is increased to ensure the
75  * socket isn't freed before the function is run; the deferred function will
76  * then drop the reference.
77  *
78  * - sk->sk_state uses the TCP state constants because they are widely used by
79  * other address families and exposed to userspace tools like ss(8):
80  *
81  *   TCP_CLOSE - unconnected
82  *   TCP_SYN_SENT - connecting
83  *   TCP_ESTABLISHED - connected
84  *   TCP_CLOSING - disconnecting
85  *   TCP_LISTEN - listening
86  */
87 
88 #include <linux/compat.h>
89 #include <linux/types.h>
90 #include <linux/bitops.h>
91 #include <linux/cred.h>
92 #include <linux/init.h>
93 #include <linux/io.h>
94 #include <linux/kernel.h>
95 #include <linux/sched/signal.h>
96 #include <linux/kmod.h>
97 #include <linux/list.h>
98 #include <linux/miscdevice.h>
99 #include <linux/module.h>
100 #include <linux/mutex.h>
101 #include <linux/net.h>
102 #include <linux/poll.h>
103 #include <linux/random.h>
104 #include <linux/skbuff.h>
105 #include <linux/smp.h>
106 #include <linux/socket.h>
107 #include <linux/stddef.h>
108 #include <linux/unistd.h>
109 #include <linux/wait.h>
110 #include <linux/workqueue.h>
111 #include <net/sock.h>
112 #include <net/af_vsock.h>
113 
114 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
115 static void vsock_sk_destruct(struct sock *sk);
116 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
117 
118 /* Protocol family. */
119 static struct proto vsock_proto = {
120 	.name = "AF_VSOCK",
121 	.owner = THIS_MODULE,
122 	.obj_size = sizeof(struct vsock_sock),
123 };
124 
125 /* The default peer timeout indicates how long we will wait for a peer response
126  * to a control message.
127  */
128 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
129 
130 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
131 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
132 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
133 
134 /* Transport used for host->guest communication */
135 static const struct vsock_transport *transport_h2g;
136 /* Transport used for guest->host communication */
137 static const struct vsock_transport *transport_g2h;
138 /* Transport used for DGRAM communication */
139 static const struct vsock_transport *transport_dgram;
140 /* Transport used for local communication */
141 static const struct vsock_transport *transport_local;
142 static DEFINE_MUTEX(vsock_register_mutex);
143 
144 /**** UTILS ****/
145 
146 /* Each bound VSocket is stored in the bind hash table and each connected
147  * VSocket is stored in the connected hash table.
148  *
149  * Unbound sockets are all put on the same list attached to the end of the hash
150  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
151  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
152  * represents the list that addr hashes to).
153  *
154  * Specifically, we initialize the vsock_bind_table array to a size of
155  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
156  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
157  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
158  * mods with VSOCK_HASH_SIZE to ensure this.
159  */
160 #define MAX_PORT_RETRIES        24
161 
162 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
163 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
164 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
165 
166 /* XXX This can probably be implemented in a better way. */
167 #define VSOCK_CONN_HASH(src, dst)				\
168 	(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
169 #define vsock_connected_sockets(src, dst)		\
170 	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
171 #define vsock_connected_sockets_vsk(vsk)				\
172 	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
173 
174 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
175 EXPORT_SYMBOL_GPL(vsock_bind_table);
176 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
177 EXPORT_SYMBOL_GPL(vsock_connected_table);
178 DEFINE_SPINLOCK(vsock_table_lock);
179 EXPORT_SYMBOL_GPL(vsock_table_lock);
180 
181 /* Autobind this socket to the local address if necessary. */
182 static int vsock_auto_bind(struct vsock_sock *vsk)
183 {
184 	struct sock *sk = sk_vsock(vsk);
185 	struct sockaddr_vm local_addr;
186 
187 	if (vsock_addr_bound(&vsk->local_addr))
188 		return 0;
189 	vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
190 	return __vsock_bind(sk, &local_addr);
191 }
192 
193 static void vsock_init_tables(void)
194 {
195 	int i;
196 
197 	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
198 		INIT_LIST_HEAD(&vsock_bind_table[i]);
199 
200 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
201 		INIT_LIST_HEAD(&vsock_connected_table[i]);
202 }
203 
204 static void __vsock_insert_bound(struct list_head *list,
205 				 struct vsock_sock *vsk)
206 {
207 	sock_hold(&vsk->sk);
208 	list_add(&vsk->bound_table, list);
209 }
210 
211 static void __vsock_insert_connected(struct list_head *list,
212 				     struct vsock_sock *vsk)
213 {
214 	sock_hold(&vsk->sk);
215 	list_add(&vsk->connected_table, list);
216 }
217 
218 static void __vsock_remove_bound(struct vsock_sock *vsk)
219 {
220 	list_del_init(&vsk->bound_table);
221 	sock_put(&vsk->sk);
222 }
223 
224 static void __vsock_remove_connected(struct vsock_sock *vsk)
225 {
226 	list_del_init(&vsk->connected_table);
227 	sock_put(&vsk->sk);
228 }
229 
230 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
231 {
232 	struct vsock_sock *vsk;
233 
234 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
235 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
236 			return sk_vsock(vsk);
237 
238 		if (addr->svm_port == vsk->local_addr.svm_port &&
239 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
240 		     addr->svm_cid == VMADDR_CID_ANY))
241 			return sk_vsock(vsk);
242 	}
243 
244 	return NULL;
245 }
246 
247 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
248 						  struct sockaddr_vm *dst)
249 {
250 	struct vsock_sock *vsk;
251 
252 	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
253 			    connected_table) {
254 		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
255 		    dst->svm_port == vsk->local_addr.svm_port) {
256 			return sk_vsock(vsk);
257 		}
258 	}
259 
260 	return NULL;
261 }
262 
263 static void vsock_insert_unbound(struct vsock_sock *vsk)
264 {
265 	spin_lock_bh(&vsock_table_lock);
266 	__vsock_insert_bound(vsock_unbound_sockets, vsk);
267 	spin_unlock_bh(&vsock_table_lock);
268 }
269 
270 void vsock_insert_connected(struct vsock_sock *vsk)
271 {
272 	struct list_head *list = vsock_connected_sockets(
273 		&vsk->remote_addr, &vsk->local_addr);
274 
275 	spin_lock_bh(&vsock_table_lock);
276 	__vsock_insert_connected(list, vsk);
277 	spin_unlock_bh(&vsock_table_lock);
278 }
279 EXPORT_SYMBOL_GPL(vsock_insert_connected);
280 
281 void vsock_remove_bound(struct vsock_sock *vsk)
282 {
283 	spin_lock_bh(&vsock_table_lock);
284 	if (__vsock_in_bound_table(vsk))
285 		__vsock_remove_bound(vsk);
286 	spin_unlock_bh(&vsock_table_lock);
287 }
288 EXPORT_SYMBOL_GPL(vsock_remove_bound);
289 
290 void vsock_remove_connected(struct vsock_sock *vsk)
291 {
292 	spin_lock_bh(&vsock_table_lock);
293 	if (__vsock_in_connected_table(vsk))
294 		__vsock_remove_connected(vsk);
295 	spin_unlock_bh(&vsock_table_lock);
296 }
297 EXPORT_SYMBOL_GPL(vsock_remove_connected);
298 
299 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
300 {
301 	struct sock *sk;
302 
303 	spin_lock_bh(&vsock_table_lock);
304 	sk = __vsock_find_bound_socket(addr);
305 	if (sk)
306 		sock_hold(sk);
307 
308 	spin_unlock_bh(&vsock_table_lock);
309 
310 	return sk;
311 }
312 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
313 
314 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
315 					 struct sockaddr_vm *dst)
316 {
317 	struct sock *sk;
318 
319 	spin_lock_bh(&vsock_table_lock);
320 	sk = __vsock_find_connected_socket(src, dst);
321 	if (sk)
322 		sock_hold(sk);
323 
324 	spin_unlock_bh(&vsock_table_lock);
325 
326 	return sk;
327 }
328 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
329 
330 void vsock_remove_sock(struct vsock_sock *vsk)
331 {
332 	vsock_remove_bound(vsk);
333 	vsock_remove_connected(vsk);
334 }
335 EXPORT_SYMBOL_GPL(vsock_remove_sock);
336 
337 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
338 {
339 	int i;
340 
341 	spin_lock_bh(&vsock_table_lock);
342 
343 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
344 		struct vsock_sock *vsk;
345 		list_for_each_entry(vsk, &vsock_connected_table[i],
346 				    connected_table)
347 			fn(sk_vsock(vsk));
348 	}
349 
350 	spin_unlock_bh(&vsock_table_lock);
351 }
352 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
353 
354 void vsock_add_pending(struct sock *listener, struct sock *pending)
355 {
356 	struct vsock_sock *vlistener;
357 	struct vsock_sock *vpending;
358 
359 	vlistener = vsock_sk(listener);
360 	vpending = vsock_sk(pending);
361 
362 	sock_hold(pending);
363 	sock_hold(listener);
364 	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
365 }
366 EXPORT_SYMBOL_GPL(vsock_add_pending);
367 
368 void vsock_remove_pending(struct sock *listener, struct sock *pending)
369 {
370 	struct vsock_sock *vpending = vsock_sk(pending);
371 
372 	list_del_init(&vpending->pending_links);
373 	sock_put(listener);
374 	sock_put(pending);
375 }
376 EXPORT_SYMBOL_GPL(vsock_remove_pending);
377 
378 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
379 {
380 	struct vsock_sock *vlistener;
381 	struct vsock_sock *vconnected;
382 
383 	vlistener = vsock_sk(listener);
384 	vconnected = vsock_sk(connected);
385 
386 	sock_hold(connected);
387 	sock_hold(listener);
388 	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
389 }
390 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
391 
392 static bool vsock_use_local_transport(unsigned int remote_cid)
393 {
394 	if (!transport_local)
395 		return false;
396 
397 	if (remote_cid == VMADDR_CID_LOCAL)
398 		return true;
399 
400 	if (transport_g2h) {
401 		return remote_cid == transport_g2h->get_local_cid();
402 	} else {
403 		return remote_cid == VMADDR_CID_HOST;
404 	}
405 }
406 
407 static void vsock_deassign_transport(struct vsock_sock *vsk)
408 {
409 	if (!vsk->transport)
410 		return;
411 
412 	vsk->transport->destruct(vsk);
413 	module_put(vsk->transport->module);
414 	vsk->transport = NULL;
415 }
416 
417 /* Assign a transport to a socket and call the .init transport callback.
418  *
419  * Note: for connection oriented socket this must be called when vsk->remote_addr
420  * is set (e.g. during the connect() or when a connection request on a listener
421  * socket is received).
422  * The vsk->remote_addr is used to decide which transport to use:
423  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
424  *    g2h is not loaded, will use local transport;
425  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
426  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
427  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
428  */
429 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
430 {
431 	const struct vsock_transport *new_transport;
432 	struct sock *sk = sk_vsock(vsk);
433 	unsigned int remote_cid = vsk->remote_addr.svm_cid;
434 	__u8 remote_flags;
435 	int ret;
436 
437 	/* If the packet is coming with the source and destination CIDs higher
438 	 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
439 	 * forwarded to the host should be established. Then the host will
440 	 * need to forward the packets to the guest.
441 	 *
442 	 * The flag is set on the (listen) receive path (psk is not NULL). On
443 	 * the connect path the flag can be set by the user space application.
444 	 */
445 	if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
446 	    vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
447 		vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
448 
449 	remote_flags = vsk->remote_addr.svm_flags;
450 
451 	switch (sk->sk_type) {
452 	case SOCK_DGRAM:
453 		new_transport = transport_dgram;
454 		break;
455 	case SOCK_STREAM:
456 	case SOCK_SEQPACKET:
457 		if (vsock_use_local_transport(remote_cid))
458 			new_transport = transport_local;
459 		else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
460 			 (remote_flags & VMADDR_FLAG_TO_HOST))
461 			new_transport = transport_g2h;
462 		else
463 			new_transport = transport_h2g;
464 		break;
465 	default:
466 		return -ESOCKTNOSUPPORT;
467 	}
468 
469 	if (vsk->transport) {
470 		if (vsk->transport == new_transport)
471 			return 0;
472 
473 		/* transport->release() must be called with sock lock acquired.
474 		 * This path can only be taken during vsock_connect(), where we
475 		 * have already held the sock lock. In the other cases, this
476 		 * function is called on a new socket which is not assigned to
477 		 * any transport.
478 		 */
479 		vsk->transport->release(vsk);
480 		vsock_deassign_transport(vsk);
481 	}
482 
483 	/* We increase the module refcnt to prevent the transport unloading
484 	 * while there are open sockets assigned to it.
485 	 */
486 	if (!new_transport || !try_module_get(new_transport->module))
487 		return -ENODEV;
488 
489 	if (sk->sk_type == SOCK_SEQPACKET) {
490 		if (!new_transport->seqpacket_allow ||
491 		    !new_transport->seqpacket_allow(remote_cid)) {
492 			module_put(new_transport->module);
493 			return -ESOCKTNOSUPPORT;
494 		}
495 	}
496 
497 	ret = new_transport->init(vsk, psk);
498 	if (ret) {
499 		module_put(new_transport->module);
500 		return ret;
501 	}
502 
503 	vsk->transport = new_transport;
504 
505 	return 0;
506 }
507 EXPORT_SYMBOL_GPL(vsock_assign_transport);
508 
509 bool vsock_find_cid(unsigned int cid)
510 {
511 	if (transport_g2h && cid == transport_g2h->get_local_cid())
512 		return true;
513 
514 	if (transport_h2g && cid == VMADDR_CID_HOST)
515 		return true;
516 
517 	if (transport_local && cid == VMADDR_CID_LOCAL)
518 		return true;
519 
520 	return false;
521 }
522 EXPORT_SYMBOL_GPL(vsock_find_cid);
523 
524 static struct sock *vsock_dequeue_accept(struct sock *listener)
525 {
526 	struct vsock_sock *vlistener;
527 	struct vsock_sock *vconnected;
528 
529 	vlistener = vsock_sk(listener);
530 
531 	if (list_empty(&vlistener->accept_queue))
532 		return NULL;
533 
534 	vconnected = list_entry(vlistener->accept_queue.next,
535 				struct vsock_sock, accept_queue);
536 
537 	list_del_init(&vconnected->accept_queue);
538 	sock_put(listener);
539 	/* The caller will need a reference on the connected socket so we let
540 	 * it call sock_put().
541 	 */
542 
543 	return sk_vsock(vconnected);
544 }
545 
546 static bool vsock_is_accept_queue_empty(struct sock *sk)
547 {
548 	struct vsock_sock *vsk = vsock_sk(sk);
549 	return list_empty(&vsk->accept_queue);
550 }
551 
552 static bool vsock_is_pending(struct sock *sk)
553 {
554 	struct vsock_sock *vsk = vsock_sk(sk);
555 	return !list_empty(&vsk->pending_links);
556 }
557 
558 static int vsock_send_shutdown(struct sock *sk, int mode)
559 {
560 	struct vsock_sock *vsk = vsock_sk(sk);
561 
562 	if (!vsk->transport)
563 		return -ENODEV;
564 
565 	return vsk->transport->shutdown(vsk, mode);
566 }
567 
568 static void vsock_pending_work(struct work_struct *work)
569 {
570 	struct sock *sk;
571 	struct sock *listener;
572 	struct vsock_sock *vsk;
573 	bool cleanup;
574 
575 	vsk = container_of(work, struct vsock_sock, pending_work.work);
576 	sk = sk_vsock(vsk);
577 	listener = vsk->listener;
578 	cleanup = true;
579 
580 	lock_sock(listener);
581 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
582 
583 	if (vsock_is_pending(sk)) {
584 		vsock_remove_pending(listener, sk);
585 
586 		sk_acceptq_removed(listener);
587 	} else if (!vsk->rejected) {
588 		/* We are not on the pending list and accept() did not reject
589 		 * us, so we must have been accepted by our user process.  We
590 		 * just need to drop our references to the sockets and be on
591 		 * our way.
592 		 */
593 		cleanup = false;
594 		goto out;
595 	}
596 
597 	/* We need to remove ourself from the global connected sockets list so
598 	 * incoming packets can't find this socket, and to reduce the reference
599 	 * count.
600 	 */
601 	vsock_remove_connected(vsk);
602 
603 	sk->sk_state = TCP_CLOSE;
604 
605 out:
606 	release_sock(sk);
607 	release_sock(listener);
608 	if (cleanup)
609 		sock_put(sk);
610 
611 	sock_put(sk);
612 	sock_put(listener);
613 }
614 
615 /**** SOCKET OPERATIONS ****/
616 
617 static int __vsock_bind_connectible(struct vsock_sock *vsk,
618 				    struct sockaddr_vm *addr)
619 {
620 	static u32 port;
621 	struct sockaddr_vm new_addr;
622 
623 	if (!port)
624 		port = LAST_RESERVED_PORT + 1 +
625 			prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
626 
627 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
628 
629 	if (addr->svm_port == VMADDR_PORT_ANY) {
630 		bool found = false;
631 		unsigned int i;
632 
633 		for (i = 0; i < MAX_PORT_RETRIES; i++) {
634 			if (port <= LAST_RESERVED_PORT)
635 				port = LAST_RESERVED_PORT + 1;
636 
637 			new_addr.svm_port = port++;
638 
639 			if (!__vsock_find_bound_socket(&new_addr)) {
640 				found = true;
641 				break;
642 			}
643 		}
644 
645 		if (!found)
646 			return -EADDRNOTAVAIL;
647 	} else {
648 		/* If port is in reserved range, ensure caller
649 		 * has necessary privileges.
650 		 */
651 		if (addr->svm_port <= LAST_RESERVED_PORT &&
652 		    !capable(CAP_NET_BIND_SERVICE)) {
653 			return -EACCES;
654 		}
655 
656 		if (__vsock_find_bound_socket(&new_addr))
657 			return -EADDRINUSE;
658 	}
659 
660 	vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
661 
662 	/* Remove connection oriented sockets from the unbound list and add them
663 	 * to the hash table for easy lookup by its address.  The unbound list
664 	 * is simply an extra entry at the end of the hash table, a trick used
665 	 * by AF_UNIX.
666 	 */
667 	__vsock_remove_bound(vsk);
668 	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
669 
670 	return 0;
671 }
672 
673 static int __vsock_bind_dgram(struct vsock_sock *vsk,
674 			      struct sockaddr_vm *addr)
675 {
676 	return vsk->transport->dgram_bind(vsk, addr);
677 }
678 
679 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
680 {
681 	struct vsock_sock *vsk = vsock_sk(sk);
682 	int retval;
683 
684 	/* First ensure this socket isn't already bound. */
685 	if (vsock_addr_bound(&vsk->local_addr))
686 		return -EINVAL;
687 
688 	/* Now bind to the provided address or select appropriate values if
689 	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
690 	 * like AF_INET prevents binding to a non-local IP address (in most
691 	 * cases), we only allow binding to a local CID.
692 	 */
693 	if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
694 		return -EADDRNOTAVAIL;
695 
696 	switch (sk->sk_socket->type) {
697 	case SOCK_STREAM:
698 	case SOCK_SEQPACKET:
699 		spin_lock_bh(&vsock_table_lock);
700 		retval = __vsock_bind_connectible(vsk, addr);
701 		spin_unlock_bh(&vsock_table_lock);
702 		break;
703 
704 	case SOCK_DGRAM:
705 		retval = __vsock_bind_dgram(vsk, addr);
706 		break;
707 
708 	default:
709 		retval = -EINVAL;
710 		break;
711 	}
712 
713 	return retval;
714 }
715 
716 static void vsock_connect_timeout(struct work_struct *work);
717 
718 static struct sock *__vsock_create(struct net *net,
719 				   struct socket *sock,
720 				   struct sock *parent,
721 				   gfp_t priority,
722 				   unsigned short type,
723 				   int kern)
724 {
725 	struct sock *sk;
726 	struct vsock_sock *psk;
727 	struct vsock_sock *vsk;
728 
729 	sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
730 	if (!sk)
731 		return NULL;
732 
733 	sock_init_data(sock, sk);
734 
735 	/* sk->sk_type is normally set in sock_init_data, but only if sock is
736 	 * non-NULL. We make sure that our sockets always have a type by
737 	 * setting it here if needed.
738 	 */
739 	if (!sock)
740 		sk->sk_type = type;
741 
742 	vsk = vsock_sk(sk);
743 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
744 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
745 
746 	sk->sk_destruct = vsock_sk_destruct;
747 	sk->sk_backlog_rcv = vsock_queue_rcv_skb;
748 	sock_reset_flag(sk, SOCK_DONE);
749 
750 	INIT_LIST_HEAD(&vsk->bound_table);
751 	INIT_LIST_HEAD(&vsk->connected_table);
752 	vsk->listener = NULL;
753 	INIT_LIST_HEAD(&vsk->pending_links);
754 	INIT_LIST_HEAD(&vsk->accept_queue);
755 	vsk->rejected = false;
756 	vsk->sent_request = false;
757 	vsk->ignore_connecting_rst = false;
758 	vsk->peer_shutdown = 0;
759 	INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
760 	INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
761 
762 	psk = parent ? vsock_sk(parent) : NULL;
763 	if (parent) {
764 		vsk->trusted = psk->trusted;
765 		vsk->owner = get_cred(psk->owner);
766 		vsk->connect_timeout = psk->connect_timeout;
767 		vsk->buffer_size = psk->buffer_size;
768 		vsk->buffer_min_size = psk->buffer_min_size;
769 		vsk->buffer_max_size = psk->buffer_max_size;
770 		security_sk_clone(parent, sk);
771 	} else {
772 		vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
773 		vsk->owner = get_current_cred();
774 		vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
775 		vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
776 		vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
777 		vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
778 	}
779 
780 	return sk;
781 }
782 
783 static bool sock_type_connectible(u16 type)
784 {
785 	return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
786 }
787 
788 static void __vsock_release(struct sock *sk, int level)
789 {
790 	if (sk) {
791 		struct sock *pending;
792 		struct vsock_sock *vsk;
793 
794 		vsk = vsock_sk(sk);
795 		pending = NULL;	/* Compiler warning. */
796 
797 		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
798 		 * version to avoid the warning "possible recursive locking
799 		 * detected". When "level" is 0, lock_sock_nested(sk, level)
800 		 * is the same as lock_sock(sk).
801 		 */
802 		lock_sock_nested(sk, level);
803 
804 		if (vsk->transport)
805 			vsk->transport->release(vsk);
806 		else if (sock_type_connectible(sk->sk_type))
807 			vsock_remove_sock(vsk);
808 
809 		sock_orphan(sk);
810 		sk->sk_shutdown = SHUTDOWN_MASK;
811 
812 		skb_queue_purge(&sk->sk_receive_queue);
813 
814 		/* Clean up any sockets that never were accepted. */
815 		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
816 			__vsock_release(pending, SINGLE_DEPTH_NESTING);
817 			sock_put(pending);
818 		}
819 
820 		release_sock(sk);
821 		sock_put(sk);
822 	}
823 }
824 
825 static void vsock_sk_destruct(struct sock *sk)
826 {
827 	struct vsock_sock *vsk = vsock_sk(sk);
828 
829 	vsock_deassign_transport(vsk);
830 
831 	/* When clearing these addresses, there's no need to set the family and
832 	 * possibly register the address family with the kernel.
833 	 */
834 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
835 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
836 
837 	put_cred(vsk->owner);
838 }
839 
840 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
841 {
842 	int err;
843 
844 	err = sock_queue_rcv_skb(sk, skb);
845 	if (err)
846 		kfree_skb(skb);
847 
848 	return err;
849 }
850 
851 struct sock *vsock_create_connected(struct sock *parent)
852 {
853 	return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
854 			      parent->sk_type, 0);
855 }
856 EXPORT_SYMBOL_GPL(vsock_create_connected);
857 
858 s64 vsock_stream_has_data(struct vsock_sock *vsk)
859 {
860 	return vsk->transport->stream_has_data(vsk);
861 }
862 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
863 
864 static s64 vsock_connectible_has_data(struct vsock_sock *vsk)
865 {
866 	struct sock *sk = sk_vsock(vsk);
867 
868 	if (sk->sk_type == SOCK_SEQPACKET)
869 		return vsk->transport->seqpacket_has_data(vsk);
870 	else
871 		return vsock_stream_has_data(vsk);
872 }
873 
874 s64 vsock_stream_has_space(struct vsock_sock *vsk)
875 {
876 	return vsk->transport->stream_has_space(vsk);
877 }
878 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
879 
880 static int vsock_release(struct socket *sock)
881 {
882 	__vsock_release(sock->sk, 0);
883 	sock->sk = NULL;
884 	sock->state = SS_FREE;
885 
886 	return 0;
887 }
888 
889 static int
890 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
891 {
892 	int err;
893 	struct sock *sk;
894 	struct sockaddr_vm *vm_addr;
895 
896 	sk = sock->sk;
897 
898 	if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
899 		return -EINVAL;
900 
901 	lock_sock(sk);
902 	err = __vsock_bind(sk, vm_addr);
903 	release_sock(sk);
904 
905 	return err;
906 }
907 
908 static int vsock_getname(struct socket *sock,
909 			 struct sockaddr *addr, int peer)
910 {
911 	int err;
912 	struct sock *sk;
913 	struct vsock_sock *vsk;
914 	struct sockaddr_vm *vm_addr;
915 
916 	sk = sock->sk;
917 	vsk = vsock_sk(sk);
918 	err = 0;
919 
920 	lock_sock(sk);
921 
922 	if (peer) {
923 		if (sock->state != SS_CONNECTED) {
924 			err = -ENOTCONN;
925 			goto out;
926 		}
927 		vm_addr = &vsk->remote_addr;
928 	} else {
929 		vm_addr = &vsk->local_addr;
930 	}
931 
932 	if (!vm_addr) {
933 		err = -EINVAL;
934 		goto out;
935 	}
936 
937 	/* sys_getsockname() and sys_getpeername() pass us a
938 	 * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
939 	 * that macro is defined in socket.c instead of .h, so we hardcode its
940 	 * value here.
941 	 */
942 	BUILD_BUG_ON(sizeof(*vm_addr) > 128);
943 	memcpy(addr, vm_addr, sizeof(*vm_addr));
944 	err = sizeof(*vm_addr);
945 
946 out:
947 	release_sock(sk);
948 	return err;
949 }
950 
951 static int vsock_shutdown(struct socket *sock, int mode)
952 {
953 	int err;
954 	struct sock *sk;
955 
956 	/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
957 	 * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
958 	 * here like the other address families do.  Note also that the
959 	 * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
960 	 * which is what we want.
961 	 */
962 	mode++;
963 
964 	if ((mode & ~SHUTDOWN_MASK) || !mode)
965 		return -EINVAL;
966 
967 	/* If this is a connection oriented socket and it is not connected then
968 	 * bail out immediately.  If it is a DGRAM socket then we must first
969 	 * kick the socket so that it wakes up from any sleeping calls, for
970 	 * example recv(), and then afterwards return the error.
971 	 */
972 
973 	sk = sock->sk;
974 
975 	lock_sock(sk);
976 	if (sock->state == SS_UNCONNECTED) {
977 		err = -ENOTCONN;
978 		if (sock_type_connectible(sk->sk_type))
979 			goto out;
980 	} else {
981 		sock->state = SS_DISCONNECTING;
982 		err = 0;
983 	}
984 
985 	/* Receive and send shutdowns are treated alike. */
986 	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
987 	if (mode) {
988 		sk->sk_shutdown |= mode;
989 		sk->sk_state_change(sk);
990 
991 		if (sock_type_connectible(sk->sk_type)) {
992 			sock_reset_flag(sk, SOCK_DONE);
993 			vsock_send_shutdown(sk, mode);
994 		}
995 	}
996 
997 out:
998 	release_sock(sk);
999 	return err;
1000 }
1001 
1002 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1003 			       poll_table *wait)
1004 {
1005 	struct sock *sk;
1006 	__poll_t mask;
1007 	struct vsock_sock *vsk;
1008 
1009 	sk = sock->sk;
1010 	vsk = vsock_sk(sk);
1011 
1012 	poll_wait(file, sk_sleep(sk), wait);
1013 	mask = 0;
1014 
1015 	if (sk->sk_err)
1016 		/* Signify that there has been an error on this socket. */
1017 		mask |= EPOLLERR;
1018 
1019 	/* INET sockets treat local write shutdown and peer write shutdown as a
1020 	 * case of EPOLLHUP set.
1021 	 */
1022 	if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1023 	    ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1024 	     (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1025 		mask |= EPOLLHUP;
1026 	}
1027 
1028 	if (sk->sk_shutdown & RCV_SHUTDOWN ||
1029 	    vsk->peer_shutdown & SEND_SHUTDOWN) {
1030 		mask |= EPOLLRDHUP;
1031 	}
1032 
1033 	if (sock->type == SOCK_DGRAM) {
1034 		/* For datagram sockets we can read if there is something in
1035 		 * the queue and write as long as the socket isn't shutdown for
1036 		 * sending.
1037 		 */
1038 		if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1039 		    (sk->sk_shutdown & RCV_SHUTDOWN)) {
1040 			mask |= EPOLLIN | EPOLLRDNORM;
1041 		}
1042 
1043 		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1044 			mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1045 
1046 	} else if (sock_type_connectible(sk->sk_type)) {
1047 		const struct vsock_transport *transport;
1048 
1049 		lock_sock(sk);
1050 
1051 		transport = vsk->transport;
1052 
1053 		/* Listening sockets that have connections in their accept
1054 		 * queue can be read.
1055 		 */
1056 		if (sk->sk_state == TCP_LISTEN
1057 		    && !vsock_is_accept_queue_empty(sk))
1058 			mask |= EPOLLIN | EPOLLRDNORM;
1059 
1060 		/* If there is something in the queue then we can read. */
1061 		if (transport && transport->stream_is_active(vsk) &&
1062 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1063 			bool data_ready_now = false;
1064 			int ret = transport->notify_poll_in(
1065 					vsk, 1, &data_ready_now);
1066 			if (ret < 0) {
1067 				mask |= EPOLLERR;
1068 			} else {
1069 				if (data_ready_now)
1070 					mask |= EPOLLIN | EPOLLRDNORM;
1071 
1072 			}
1073 		}
1074 
1075 		/* Sockets whose connections have been closed, reset, or
1076 		 * terminated should also be considered read, and we check the
1077 		 * shutdown flag for that.
1078 		 */
1079 		if (sk->sk_shutdown & RCV_SHUTDOWN ||
1080 		    vsk->peer_shutdown & SEND_SHUTDOWN) {
1081 			mask |= EPOLLIN | EPOLLRDNORM;
1082 		}
1083 
1084 		/* Connected sockets that can produce data can be written. */
1085 		if (transport && sk->sk_state == TCP_ESTABLISHED) {
1086 			if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1087 				bool space_avail_now = false;
1088 				int ret = transport->notify_poll_out(
1089 						vsk, 1, &space_avail_now);
1090 				if (ret < 0) {
1091 					mask |= EPOLLERR;
1092 				} else {
1093 					if (space_avail_now)
1094 						/* Remove EPOLLWRBAND since INET
1095 						 * sockets are not setting it.
1096 						 */
1097 						mask |= EPOLLOUT | EPOLLWRNORM;
1098 
1099 				}
1100 			}
1101 		}
1102 
1103 		/* Simulate INET socket poll behaviors, which sets
1104 		 * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1105 		 * but local send is not shutdown.
1106 		 */
1107 		if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1108 			if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1109 				mask |= EPOLLOUT | EPOLLWRNORM;
1110 
1111 		}
1112 
1113 		release_sock(sk);
1114 	}
1115 
1116 	return mask;
1117 }
1118 
1119 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1120 			       size_t len)
1121 {
1122 	int err;
1123 	struct sock *sk;
1124 	struct vsock_sock *vsk;
1125 	struct sockaddr_vm *remote_addr;
1126 	const struct vsock_transport *transport;
1127 
1128 	if (msg->msg_flags & MSG_OOB)
1129 		return -EOPNOTSUPP;
1130 
1131 	/* For now, MSG_DONTWAIT is always assumed... */
1132 	err = 0;
1133 	sk = sock->sk;
1134 	vsk = vsock_sk(sk);
1135 
1136 	lock_sock(sk);
1137 
1138 	transport = vsk->transport;
1139 
1140 	err = vsock_auto_bind(vsk);
1141 	if (err)
1142 		goto out;
1143 
1144 
1145 	/* If the provided message contains an address, use that.  Otherwise
1146 	 * fall back on the socket's remote handle (if it has been connected).
1147 	 */
1148 	if (msg->msg_name &&
1149 	    vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1150 			    &remote_addr) == 0) {
1151 		/* Ensure this address is of the right type and is a valid
1152 		 * destination.
1153 		 */
1154 
1155 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1156 			remote_addr->svm_cid = transport->get_local_cid();
1157 
1158 		if (!vsock_addr_bound(remote_addr)) {
1159 			err = -EINVAL;
1160 			goto out;
1161 		}
1162 	} else if (sock->state == SS_CONNECTED) {
1163 		remote_addr = &vsk->remote_addr;
1164 
1165 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1166 			remote_addr->svm_cid = transport->get_local_cid();
1167 
1168 		/* XXX Should connect() or this function ensure remote_addr is
1169 		 * bound?
1170 		 */
1171 		if (!vsock_addr_bound(&vsk->remote_addr)) {
1172 			err = -EINVAL;
1173 			goto out;
1174 		}
1175 	} else {
1176 		err = -EINVAL;
1177 		goto out;
1178 	}
1179 
1180 	if (!transport->dgram_allow(remote_addr->svm_cid,
1181 				    remote_addr->svm_port)) {
1182 		err = -EINVAL;
1183 		goto out;
1184 	}
1185 
1186 	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1187 
1188 out:
1189 	release_sock(sk);
1190 	return err;
1191 }
1192 
1193 static int vsock_dgram_connect(struct socket *sock,
1194 			       struct sockaddr *addr, int addr_len, int flags)
1195 {
1196 	int err;
1197 	struct sock *sk;
1198 	struct vsock_sock *vsk;
1199 	struct sockaddr_vm *remote_addr;
1200 
1201 	sk = sock->sk;
1202 	vsk = vsock_sk(sk);
1203 
1204 	err = vsock_addr_cast(addr, addr_len, &remote_addr);
1205 	if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1206 		lock_sock(sk);
1207 		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1208 				VMADDR_PORT_ANY);
1209 		sock->state = SS_UNCONNECTED;
1210 		release_sock(sk);
1211 		return 0;
1212 	} else if (err != 0)
1213 		return -EINVAL;
1214 
1215 	lock_sock(sk);
1216 
1217 	err = vsock_auto_bind(vsk);
1218 	if (err)
1219 		goto out;
1220 
1221 	if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1222 					 remote_addr->svm_port)) {
1223 		err = -EINVAL;
1224 		goto out;
1225 	}
1226 
1227 	memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1228 	sock->state = SS_CONNECTED;
1229 
1230 out:
1231 	release_sock(sk);
1232 	return err;
1233 }
1234 
1235 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1236 			       size_t len, int flags)
1237 {
1238 	struct vsock_sock *vsk = vsock_sk(sock->sk);
1239 
1240 	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1241 }
1242 
1243 static const struct proto_ops vsock_dgram_ops = {
1244 	.family = PF_VSOCK,
1245 	.owner = THIS_MODULE,
1246 	.release = vsock_release,
1247 	.bind = vsock_bind,
1248 	.connect = vsock_dgram_connect,
1249 	.socketpair = sock_no_socketpair,
1250 	.accept = sock_no_accept,
1251 	.getname = vsock_getname,
1252 	.poll = vsock_poll,
1253 	.ioctl = sock_no_ioctl,
1254 	.listen = sock_no_listen,
1255 	.shutdown = vsock_shutdown,
1256 	.sendmsg = vsock_dgram_sendmsg,
1257 	.recvmsg = vsock_dgram_recvmsg,
1258 	.mmap = sock_no_mmap,
1259 	.sendpage = sock_no_sendpage,
1260 };
1261 
1262 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1263 {
1264 	const struct vsock_transport *transport = vsk->transport;
1265 
1266 	if (!transport || !transport->cancel_pkt)
1267 		return -EOPNOTSUPP;
1268 
1269 	return transport->cancel_pkt(vsk);
1270 }
1271 
1272 static void vsock_connect_timeout(struct work_struct *work)
1273 {
1274 	struct sock *sk;
1275 	struct vsock_sock *vsk;
1276 
1277 	vsk = container_of(work, struct vsock_sock, connect_work.work);
1278 	sk = sk_vsock(vsk);
1279 
1280 	lock_sock(sk);
1281 	if (sk->sk_state == TCP_SYN_SENT &&
1282 	    (sk->sk_shutdown != SHUTDOWN_MASK)) {
1283 		sk->sk_state = TCP_CLOSE;
1284 		sk->sk_err = ETIMEDOUT;
1285 		sk_error_report(sk);
1286 		vsock_transport_cancel_pkt(vsk);
1287 	}
1288 	release_sock(sk);
1289 
1290 	sock_put(sk);
1291 }
1292 
1293 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1294 			 int addr_len, int flags)
1295 {
1296 	int err;
1297 	struct sock *sk;
1298 	struct vsock_sock *vsk;
1299 	const struct vsock_transport *transport;
1300 	struct sockaddr_vm *remote_addr;
1301 	long timeout;
1302 	DEFINE_WAIT(wait);
1303 
1304 	err = 0;
1305 	sk = sock->sk;
1306 	vsk = vsock_sk(sk);
1307 
1308 	lock_sock(sk);
1309 
1310 	/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1311 	switch (sock->state) {
1312 	case SS_CONNECTED:
1313 		err = -EISCONN;
1314 		goto out;
1315 	case SS_DISCONNECTING:
1316 		err = -EINVAL;
1317 		goto out;
1318 	case SS_CONNECTING:
1319 		/* This continues on so we can move sock into the SS_CONNECTED
1320 		 * state once the connection has completed (at which point err
1321 		 * will be set to zero also).  Otherwise, we will either wait
1322 		 * for the connection or return -EALREADY should this be a
1323 		 * non-blocking call.
1324 		 */
1325 		err = -EALREADY;
1326 		if (flags & O_NONBLOCK)
1327 			goto out;
1328 		break;
1329 	default:
1330 		if ((sk->sk_state == TCP_LISTEN) ||
1331 		    vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1332 			err = -EINVAL;
1333 			goto out;
1334 		}
1335 
1336 		/* Set the remote address that we are connecting to. */
1337 		memcpy(&vsk->remote_addr, remote_addr,
1338 		       sizeof(vsk->remote_addr));
1339 
1340 		err = vsock_assign_transport(vsk, NULL);
1341 		if (err)
1342 			goto out;
1343 
1344 		transport = vsk->transport;
1345 
1346 		/* The hypervisor and well-known contexts do not have socket
1347 		 * endpoints.
1348 		 */
1349 		if (!transport ||
1350 		    !transport->stream_allow(remote_addr->svm_cid,
1351 					     remote_addr->svm_port)) {
1352 			err = -ENETUNREACH;
1353 			goto out;
1354 		}
1355 
1356 		err = vsock_auto_bind(vsk);
1357 		if (err)
1358 			goto out;
1359 
1360 		sk->sk_state = TCP_SYN_SENT;
1361 
1362 		err = transport->connect(vsk);
1363 		if (err < 0)
1364 			goto out;
1365 
1366 		/* Mark sock as connecting and set the error code to in
1367 		 * progress in case this is a non-blocking connect.
1368 		 */
1369 		sock->state = SS_CONNECTING;
1370 		err = -EINPROGRESS;
1371 	}
1372 
1373 	/* The receive path will handle all communication until we are able to
1374 	 * enter the connected state.  Here we wait for the connection to be
1375 	 * completed or a notification of an error.
1376 	 */
1377 	timeout = vsk->connect_timeout;
1378 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1379 
1380 	while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1381 		if (flags & O_NONBLOCK) {
1382 			/* If we're not going to block, we schedule a timeout
1383 			 * function to generate a timeout on the connection
1384 			 * attempt, in case the peer doesn't respond in a
1385 			 * timely manner. We hold on to the socket until the
1386 			 * timeout fires.
1387 			 */
1388 			sock_hold(sk);
1389 			schedule_delayed_work(&vsk->connect_work, timeout);
1390 
1391 			/* Skip ahead to preserve error code set above. */
1392 			goto out_wait;
1393 		}
1394 
1395 		release_sock(sk);
1396 		timeout = schedule_timeout(timeout);
1397 		lock_sock(sk);
1398 
1399 		if (signal_pending(current)) {
1400 			err = sock_intr_errno(timeout);
1401 			sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1402 			sock->state = SS_UNCONNECTED;
1403 			vsock_transport_cancel_pkt(vsk);
1404 			goto out_wait;
1405 		} else if (timeout == 0) {
1406 			err = -ETIMEDOUT;
1407 			sk->sk_state = TCP_CLOSE;
1408 			sock->state = SS_UNCONNECTED;
1409 			vsock_transport_cancel_pkt(vsk);
1410 			goto out_wait;
1411 		}
1412 
1413 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1414 	}
1415 
1416 	if (sk->sk_err) {
1417 		err = -sk->sk_err;
1418 		sk->sk_state = TCP_CLOSE;
1419 		sock->state = SS_UNCONNECTED;
1420 	} else {
1421 		err = 0;
1422 	}
1423 
1424 out_wait:
1425 	finish_wait(sk_sleep(sk), &wait);
1426 out:
1427 	release_sock(sk);
1428 	return err;
1429 }
1430 
1431 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1432 			bool kern)
1433 {
1434 	struct sock *listener;
1435 	int err;
1436 	struct sock *connected;
1437 	struct vsock_sock *vconnected;
1438 	long timeout;
1439 	DEFINE_WAIT(wait);
1440 
1441 	err = 0;
1442 	listener = sock->sk;
1443 
1444 	lock_sock(listener);
1445 
1446 	if (!sock_type_connectible(sock->type)) {
1447 		err = -EOPNOTSUPP;
1448 		goto out;
1449 	}
1450 
1451 	if (listener->sk_state != TCP_LISTEN) {
1452 		err = -EINVAL;
1453 		goto out;
1454 	}
1455 
1456 	/* Wait for children sockets to appear; these are the new sockets
1457 	 * created upon connection establishment.
1458 	 */
1459 	timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1460 	prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1461 
1462 	while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1463 	       listener->sk_err == 0) {
1464 		release_sock(listener);
1465 		timeout = schedule_timeout(timeout);
1466 		finish_wait(sk_sleep(listener), &wait);
1467 		lock_sock(listener);
1468 
1469 		if (signal_pending(current)) {
1470 			err = sock_intr_errno(timeout);
1471 			goto out;
1472 		} else if (timeout == 0) {
1473 			err = -EAGAIN;
1474 			goto out;
1475 		}
1476 
1477 		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1478 	}
1479 	finish_wait(sk_sleep(listener), &wait);
1480 
1481 	if (listener->sk_err)
1482 		err = -listener->sk_err;
1483 
1484 	if (connected) {
1485 		sk_acceptq_removed(listener);
1486 
1487 		lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1488 		vconnected = vsock_sk(connected);
1489 
1490 		/* If the listener socket has received an error, then we should
1491 		 * reject this socket and return.  Note that we simply mark the
1492 		 * socket rejected, drop our reference, and let the cleanup
1493 		 * function handle the cleanup; the fact that we found it in
1494 		 * the listener's accept queue guarantees that the cleanup
1495 		 * function hasn't run yet.
1496 		 */
1497 		if (err) {
1498 			vconnected->rejected = true;
1499 		} else {
1500 			newsock->state = SS_CONNECTED;
1501 			sock_graft(connected, newsock);
1502 		}
1503 
1504 		release_sock(connected);
1505 		sock_put(connected);
1506 	}
1507 
1508 out:
1509 	release_sock(listener);
1510 	return err;
1511 }
1512 
1513 static int vsock_listen(struct socket *sock, int backlog)
1514 {
1515 	int err;
1516 	struct sock *sk;
1517 	struct vsock_sock *vsk;
1518 
1519 	sk = sock->sk;
1520 
1521 	lock_sock(sk);
1522 
1523 	if (!sock_type_connectible(sk->sk_type)) {
1524 		err = -EOPNOTSUPP;
1525 		goto out;
1526 	}
1527 
1528 	if (sock->state != SS_UNCONNECTED) {
1529 		err = -EINVAL;
1530 		goto out;
1531 	}
1532 
1533 	vsk = vsock_sk(sk);
1534 
1535 	if (!vsock_addr_bound(&vsk->local_addr)) {
1536 		err = -EINVAL;
1537 		goto out;
1538 	}
1539 
1540 	sk->sk_max_ack_backlog = backlog;
1541 	sk->sk_state = TCP_LISTEN;
1542 
1543 	err = 0;
1544 
1545 out:
1546 	release_sock(sk);
1547 	return err;
1548 }
1549 
1550 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1551 				     const struct vsock_transport *transport,
1552 				     u64 val)
1553 {
1554 	if (val > vsk->buffer_max_size)
1555 		val = vsk->buffer_max_size;
1556 
1557 	if (val < vsk->buffer_min_size)
1558 		val = vsk->buffer_min_size;
1559 
1560 	if (val != vsk->buffer_size &&
1561 	    transport && transport->notify_buffer_size)
1562 		transport->notify_buffer_size(vsk, &val);
1563 
1564 	vsk->buffer_size = val;
1565 }
1566 
1567 static int vsock_connectible_setsockopt(struct socket *sock,
1568 					int level,
1569 					int optname,
1570 					sockptr_t optval,
1571 					unsigned int optlen)
1572 {
1573 	int err;
1574 	struct sock *sk;
1575 	struct vsock_sock *vsk;
1576 	const struct vsock_transport *transport;
1577 	u64 val;
1578 
1579 	if (level != AF_VSOCK)
1580 		return -ENOPROTOOPT;
1581 
1582 #define COPY_IN(_v)                                       \
1583 	do {						  \
1584 		if (optlen < sizeof(_v)) {		  \
1585 			err = -EINVAL;			  \
1586 			goto exit;			  \
1587 		}					  \
1588 		if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {	\
1589 			err = -EFAULT;					\
1590 			goto exit;					\
1591 		}							\
1592 	} while (0)
1593 
1594 	err = 0;
1595 	sk = sock->sk;
1596 	vsk = vsock_sk(sk);
1597 
1598 	lock_sock(sk);
1599 
1600 	transport = vsk->transport;
1601 
1602 	switch (optname) {
1603 	case SO_VM_SOCKETS_BUFFER_SIZE:
1604 		COPY_IN(val);
1605 		vsock_update_buffer_size(vsk, transport, val);
1606 		break;
1607 
1608 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1609 		COPY_IN(val);
1610 		vsk->buffer_max_size = val;
1611 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1612 		break;
1613 
1614 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1615 		COPY_IN(val);
1616 		vsk->buffer_min_size = val;
1617 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1618 		break;
1619 
1620 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1621 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1622 		struct __kernel_sock_timeval tv;
1623 
1624 		err = sock_copy_user_timeval(&tv, optval, optlen,
1625 					     optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1626 		if (err)
1627 			break;
1628 		if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1629 		    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1630 			vsk->connect_timeout = tv.tv_sec * HZ +
1631 				DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1632 			if (vsk->connect_timeout == 0)
1633 				vsk->connect_timeout =
1634 				    VSOCK_DEFAULT_CONNECT_TIMEOUT;
1635 
1636 		} else {
1637 			err = -ERANGE;
1638 		}
1639 		break;
1640 	}
1641 
1642 	default:
1643 		err = -ENOPROTOOPT;
1644 		break;
1645 	}
1646 
1647 #undef COPY_IN
1648 
1649 exit:
1650 	release_sock(sk);
1651 	return err;
1652 }
1653 
1654 static int vsock_connectible_getsockopt(struct socket *sock,
1655 					int level, int optname,
1656 					char __user *optval,
1657 					int __user *optlen)
1658 {
1659 	struct sock *sk = sock->sk;
1660 	struct vsock_sock *vsk = vsock_sk(sk);
1661 
1662 	union {
1663 		u64 val64;
1664 		struct old_timeval32 tm32;
1665 		struct __kernel_old_timeval tm;
1666 		struct  __kernel_sock_timeval stm;
1667 	} v;
1668 
1669 	int lv = sizeof(v.val64);
1670 	int len;
1671 
1672 	if (level != AF_VSOCK)
1673 		return -ENOPROTOOPT;
1674 
1675 	if (get_user(len, optlen))
1676 		return -EFAULT;
1677 
1678 	memset(&v, 0, sizeof(v));
1679 
1680 	switch (optname) {
1681 	case SO_VM_SOCKETS_BUFFER_SIZE:
1682 		v.val64 = vsk->buffer_size;
1683 		break;
1684 
1685 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1686 		v.val64 = vsk->buffer_max_size;
1687 		break;
1688 
1689 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1690 		v.val64 = vsk->buffer_min_size;
1691 		break;
1692 
1693 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1694 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1695 		lv = sock_get_timeout(vsk->connect_timeout, &v,
1696 				      optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1697 		break;
1698 
1699 	default:
1700 		return -ENOPROTOOPT;
1701 	}
1702 
1703 	if (len < lv)
1704 		return -EINVAL;
1705 	if (len > lv)
1706 		len = lv;
1707 	if (copy_to_user(optval, &v, len))
1708 		return -EFAULT;
1709 
1710 	if (put_user(len, optlen))
1711 		return -EFAULT;
1712 
1713 	return 0;
1714 }
1715 
1716 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1717 				     size_t len)
1718 {
1719 	struct sock *sk;
1720 	struct vsock_sock *vsk;
1721 	const struct vsock_transport *transport;
1722 	ssize_t total_written;
1723 	long timeout;
1724 	int err;
1725 	struct vsock_transport_send_notify_data send_data;
1726 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1727 
1728 	sk = sock->sk;
1729 	vsk = vsock_sk(sk);
1730 	total_written = 0;
1731 	err = 0;
1732 
1733 	if (msg->msg_flags & MSG_OOB)
1734 		return -EOPNOTSUPP;
1735 
1736 	lock_sock(sk);
1737 
1738 	transport = vsk->transport;
1739 
1740 	/* Callers should not provide a destination with connection oriented
1741 	 * sockets.
1742 	 */
1743 	if (msg->msg_namelen) {
1744 		err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1745 		goto out;
1746 	}
1747 
1748 	/* Send data only if both sides are not shutdown in the direction. */
1749 	if (sk->sk_shutdown & SEND_SHUTDOWN ||
1750 	    vsk->peer_shutdown & RCV_SHUTDOWN) {
1751 		err = -EPIPE;
1752 		goto out;
1753 	}
1754 
1755 	if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1756 	    !vsock_addr_bound(&vsk->local_addr)) {
1757 		err = -ENOTCONN;
1758 		goto out;
1759 	}
1760 
1761 	if (!vsock_addr_bound(&vsk->remote_addr)) {
1762 		err = -EDESTADDRREQ;
1763 		goto out;
1764 	}
1765 
1766 	/* Wait for room in the produce queue to enqueue our user's data. */
1767 	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1768 
1769 	err = transport->notify_send_init(vsk, &send_data);
1770 	if (err < 0)
1771 		goto out;
1772 
1773 	while (total_written < len) {
1774 		ssize_t written;
1775 
1776 		add_wait_queue(sk_sleep(sk), &wait);
1777 		while (vsock_stream_has_space(vsk) == 0 &&
1778 		       sk->sk_err == 0 &&
1779 		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1780 		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1781 
1782 			/* Don't wait for non-blocking sockets. */
1783 			if (timeout == 0) {
1784 				err = -EAGAIN;
1785 				remove_wait_queue(sk_sleep(sk), &wait);
1786 				goto out_err;
1787 			}
1788 
1789 			err = transport->notify_send_pre_block(vsk, &send_data);
1790 			if (err < 0) {
1791 				remove_wait_queue(sk_sleep(sk), &wait);
1792 				goto out_err;
1793 			}
1794 
1795 			release_sock(sk);
1796 			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1797 			lock_sock(sk);
1798 			if (signal_pending(current)) {
1799 				err = sock_intr_errno(timeout);
1800 				remove_wait_queue(sk_sleep(sk), &wait);
1801 				goto out_err;
1802 			} else if (timeout == 0) {
1803 				err = -EAGAIN;
1804 				remove_wait_queue(sk_sleep(sk), &wait);
1805 				goto out_err;
1806 			}
1807 		}
1808 		remove_wait_queue(sk_sleep(sk), &wait);
1809 
1810 		/* These checks occur both as part of and after the loop
1811 		 * conditional since we need to check before and after
1812 		 * sleeping.
1813 		 */
1814 		if (sk->sk_err) {
1815 			err = -sk->sk_err;
1816 			goto out_err;
1817 		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1818 			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1819 			err = -EPIPE;
1820 			goto out_err;
1821 		}
1822 
1823 		err = transport->notify_send_pre_enqueue(vsk, &send_data);
1824 		if (err < 0)
1825 			goto out_err;
1826 
1827 		/* Note that enqueue will only write as many bytes as are free
1828 		 * in the produce queue, so we don't need to ensure len is
1829 		 * smaller than the queue size.  It is the caller's
1830 		 * responsibility to check how many bytes we were able to send.
1831 		 */
1832 
1833 		if (sk->sk_type == SOCK_SEQPACKET) {
1834 			written = transport->seqpacket_enqueue(vsk,
1835 						msg, len - total_written);
1836 		} else {
1837 			written = transport->stream_enqueue(vsk,
1838 					msg, len - total_written);
1839 		}
1840 		if (written < 0) {
1841 			err = -ENOMEM;
1842 			goto out_err;
1843 		}
1844 
1845 		total_written += written;
1846 
1847 		err = transport->notify_send_post_enqueue(
1848 				vsk, written, &send_data);
1849 		if (err < 0)
1850 			goto out_err;
1851 
1852 	}
1853 
1854 out_err:
1855 	if (total_written > 0) {
1856 		/* Return number of written bytes only if:
1857 		 * 1) SOCK_STREAM socket.
1858 		 * 2) SOCK_SEQPACKET socket when whole buffer is sent.
1859 		 */
1860 		if (sk->sk_type == SOCK_STREAM || total_written == len)
1861 			err = total_written;
1862 	}
1863 out:
1864 	release_sock(sk);
1865 	return err;
1866 }
1867 
1868 static int vsock_connectible_wait_data(struct sock *sk,
1869 				       struct wait_queue_entry *wait,
1870 				       long timeout,
1871 				       struct vsock_transport_recv_notify_data *recv_data,
1872 				       size_t target)
1873 {
1874 	const struct vsock_transport *transport;
1875 	struct vsock_sock *vsk;
1876 	s64 data;
1877 	int err;
1878 
1879 	vsk = vsock_sk(sk);
1880 	err = 0;
1881 	transport = vsk->transport;
1882 
1883 	while ((data = vsock_connectible_has_data(vsk)) == 0) {
1884 		prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
1885 
1886 		if (sk->sk_err != 0 ||
1887 		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
1888 		    (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1889 			break;
1890 		}
1891 
1892 		/* Don't wait for non-blocking sockets. */
1893 		if (timeout == 0) {
1894 			err = -EAGAIN;
1895 			break;
1896 		}
1897 
1898 		if (recv_data) {
1899 			err = transport->notify_recv_pre_block(vsk, target, recv_data);
1900 			if (err < 0)
1901 				break;
1902 		}
1903 
1904 		release_sock(sk);
1905 		timeout = schedule_timeout(timeout);
1906 		lock_sock(sk);
1907 
1908 		if (signal_pending(current)) {
1909 			err = sock_intr_errno(timeout);
1910 			break;
1911 		} else if (timeout == 0) {
1912 			err = -EAGAIN;
1913 			break;
1914 		}
1915 	}
1916 
1917 	finish_wait(sk_sleep(sk), wait);
1918 
1919 	if (err)
1920 		return err;
1921 
1922 	/* Internal transport error when checking for available
1923 	 * data. XXX This should be changed to a connection
1924 	 * reset in a later change.
1925 	 */
1926 	if (data < 0)
1927 		return -ENOMEM;
1928 
1929 	return data;
1930 }
1931 
1932 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
1933 				  size_t len, int flags)
1934 {
1935 	struct vsock_transport_recv_notify_data recv_data;
1936 	const struct vsock_transport *transport;
1937 	struct vsock_sock *vsk;
1938 	ssize_t copied;
1939 	size_t target;
1940 	long timeout;
1941 	int err;
1942 
1943 	DEFINE_WAIT(wait);
1944 
1945 	vsk = vsock_sk(sk);
1946 	transport = vsk->transport;
1947 
1948 	/* We must not copy less than target bytes into the user's buffer
1949 	 * before returning successfully, so we wait for the consume queue to
1950 	 * have that much data to consume before dequeueing.  Note that this
1951 	 * makes it impossible to handle cases where target is greater than the
1952 	 * queue size.
1953 	 */
1954 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1955 	if (target >= transport->stream_rcvhiwat(vsk)) {
1956 		err = -ENOMEM;
1957 		goto out;
1958 	}
1959 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1960 	copied = 0;
1961 
1962 	err = transport->notify_recv_init(vsk, target, &recv_data);
1963 	if (err < 0)
1964 		goto out;
1965 
1966 
1967 	while (1) {
1968 		ssize_t read;
1969 
1970 		err = vsock_connectible_wait_data(sk, &wait, timeout,
1971 						  &recv_data, target);
1972 		if (err <= 0)
1973 			break;
1974 
1975 		err = transport->notify_recv_pre_dequeue(vsk, target,
1976 							 &recv_data);
1977 		if (err < 0)
1978 			break;
1979 
1980 		read = transport->stream_dequeue(vsk, msg, len - copied, flags);
1981 		if (read < 0) {
1982 			err = -ENOMEM;
1983 			break;
1984 		}
1985 
1986 		copied += read;
1987 
1988 		err = transport->notify_recv_post_dequeue(vsk, target, read,
1989 						!(flags & MSG_PEEK), &recv_data);
1990 		if (err < 0)
1991 			goto out;
1992 
1993 		if (read >= target || flags & MSG_PEEK)
1994 			break;
1995 
1996 		target -= read;
1997 	}
1998 
1999 	if (sk->sk_err)
2000 		err = -sk->sk_err;
2001 	else if (sk->sk_shutdown & RCV_SHUTDOWN)
2002 		err = 0;
2003 
2004 	if (copied > 0)
2005 		err = copied;
2006 
2007 out:
2008 	return err;
2009 }
2010 
2011 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2012 				     size_t len, int flags)
2013 {
2014 	const struct vsock_transport *transport;
2015 	struct vsock_sock *vsk;
2016 	ssize_t msg_len;
2017 	long timeout;
2018 	int err = 0;
2019 	DEFINE_WAIT(wait);
2020 
2021 	vsk = vsock_sk(sk);
2022 	transport = vsk->transport;
2023 
2024 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2025 
2026 	err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2027 	if (err <= 0)
2028 		goto out;
2029 
2030 	msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2031 
2032 	if (msg_len < 0) {
2033 		err = -ENOMEM;
2034 		goto out;
2035 	}
2036 
2037 	if (sk->sk_err) {
2038 		err = -sk->sk_err;
2039 	} else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2040 		err = 0;
2041 	} else {
2042 		/* User sets MSG_TRUNC, so return real length of
2043 		 * packet.
2044 		 */
2045 		if (flags & MSG_TRUNC)
2046 			err = msg_len;
2047 		else
2048 			err = len - msg_data_left(msg);
2049 
2050 		/* Always set MSG_TRUNC if real length of packet is
2051 		 * bigger than user's buffer.
2052 		 */
2053 		if (msg_len > len)
2054 			msg->msg_flags |= MSG_TRUNC;
2055 	}
2056 
2057 out:
2058 	return err;
2059 }
2060 
2061 static int
2062 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2063 			  int flags)
2064 {
2065 	struct sock *sk;
2066 	struct vsock_sock *vsk;
2067 	const struct vsock_transport *transport;
2068 	int err;
2069 
2070 	DEFINE_WAIT(wait);
2071 
2072 	sk = sock->sk;
2073 	vsk = vsock_sk(sk);
2074 	err = 0;
2075 
2076 	lock_sock(sk);
2077 
2078 	transport = vsk->transport;
2079 
2080 	if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2081 		/* Recvmsg is supposed to return 0 if a peer performs an
2082 		 * orderly shutdown. Differentiate between that case and when a
2083 		 * peer has not connected or a local shutdown occurred with the
2084 		 * SOCK_DONE flag.
2085 		 */
2086 		if (sock_flag(sk, SOCK_DONE))
2087 			err = 0;
2088 		else
2089 			err = -ENOTCONN;
2090 
2091 		goto out;
2092 	}
2093 
2094 	if (flags & MSG_OOB) {
2095 		err = -EOPNOTSUPP;
2096 		goto out;
2097 	}
2098 
2099 	/* We don't check peer_shutdown flag here since peer may actually shut
2100 	 * down, but there can be data in the queue that a local socket can
2101 	 * receive.
2102 	 */
2103 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2104 		err = 0;
2105 		goto out;
2106 	}
2107 
2108 	/* It is valid on Linux to pass in a zero-length receive buffer.  This
2109 	 * is not an error.  We may as well bail out now.
2110 	 */
2111 	if (!len) {
2112 		err = 0;
2113 		goto out;
2114 	}
2115 
2116 	if (sk->sk_type == SOCK_STREAM)
2117 		err = __vsock_stream_recvmsg(sk, msg, len, flags);
2118 	else
2119 		err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2120 
2121 out:
2122 	release_sock(sk);
2123 	return err;
2124 }
2125 
2126 static const struct proto_ops vsock_stream_ops = {
2127 	.family = PF_VSOCK,
2128 	.owner = THIS_MODULE,
2129 	.release = vsock_release,
2130 	.bind = vsock_bind,
2131 	.connect = vsock_connect,
2132 	.socketpair = sock_no_socketpair,
2133 	.accept = vsock_accept,
2134 	.getname = vsock_getname,
2135 	.poll = vsock_poll,
2136 	.ioctl = sock_no_ioctl,
2137 	.listen = vsock_listen,
2138 	.shutdown = vsock_shutdown,
2139 	.setsockopt = vsock_connectible_setsockopt,
2140 	.getsockopt = vsock_connectible_getsockopt,
2141 	.sendmsg = vsock_connectible_sendmsg,
2142 	.recvmsg = vsock_connectible_recvmsg,
2143 	.mmap = sock_no_mmap,
2144 	.sendpage = sock_no_sendpage,
2145 };
2146 
2147 static const struct proto_ops vsock_seqpacket_ops = {
2148 	.family = PF_VSOCK,
2149 	.owner = THIS_MODULE,
2150 	.release = vsock_release,
2151 	.bind = vsock_bind,
2152 	.connect = vsock_connect,
2153 	.socketpair = sock_no_socketpair,
2154 	.accept = vsock_accept,
2155 	.getname = vsock_getname,
2156 	.poll = vsock_poll,
2157 	.ioctl = sock_no_ioctl,
2158 	.listen = vsock_listen,
2159 	.shutdown = vsock_shutdown,
2160 	.setsockopt = vsock_connectible_setsockopt,
2161 	.getsockopt = vsock_connectible_getsockopt,
2162 	.sendmsg = vsock_connectible_sendmsg,
2163 	.recvmsg = vsock_connectible_recvmsg,
2164 	.mmap = sock_no_mmap,
2165 	.sendpage = sock_no_sendpage,
2166 };
2167 
2168 static int vsock_create(struct net *net, struct socket *sock,
2169 			int protocol, int kern)
2170 {
2171 	struct vsock_sock *vsk;
2172 	struct sock *sk;
2173 	int ret;
2174 
2175 	if (!sock)
2176 		return -EINVAL;
2177 
2178 	if (protocol && protocol != PF_VSOCK)
2179 		return -EPROTONOSUPPORT;
2180 
2181 	switch (sock->type) {
2182 	case SOCK_DGRAM:
2183 		sock->ops = &vsock_dgram_ops;
2184 		break;
2185 	case SOCK_STREAM:
2186 		sock->ops = &vsock_stream_ops;
2187 		break;
2188 	case SOCK_SEQPACKET:
2189 		sock->ops = &vsock_seqpacket_ops;
2190 		break;
2191 	default:
2192 		return -ESOCKTNOSUPPORT;
2193 	}
2194 
2195 	sock->state = SS_UNCONNECTED;
2196 
2197 	sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2198 	if (!sk)
2199 		return -ENOMEM;
2200 
2201 	vsk = vsock_sk(sk);
2202 
2203 	if (sock->type == SOCK_DGRAM) {
2204 		ret = vsock_assign_transport(vsk, NULL);
2205 		if (ret < 0) {
2206 			sock_put(sk);
2207 			return ret;
2208 		}
2209 	}
2210 
2211 	vsock_insert_unbound(vsk);
2212 
2213 	return 0;
2214 }
2215 
2216 static const struct net_proto_family vsock_family_ops = {
2217 	.family = AF_VSOCK,
2218 	.create = vsock_create,
2219 	.owner = THIS_MODULE,
2220 };
2221 
2222 static long vsock_dev_do_ioctl(struct file *filp,
2223 			       unsigned int cmd, void __user *ptr)
2224 {
2225 	u32 __user *p = ptr;
2226 	u32 cid = VMADDR_CID_ANY;
2227 	int retval = 0;
2228 
2229 	switch (cmd) {
2230 	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2231 		/* To be compatible with the VMCI behavior, we prioritize the
2232 		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2233 		 */
2234 		if (transport_g2h)
2235 			cid = transport_g2h->get_local_cid();
2236 		else if (transport_h2g)
2237 			cid = transport_h2g->get_local_cid();
2238 
2239 		if (put_user(cid, p) != 0)
2240 			retval = -EFAULT;
2241 		break;
2242 
2243 	default:
2244 		retval = -ENOIOCTLCMD;
2245 	}
2246 
2247 	return retval;
2248 }
2249 
2250 static long vsock_dev_ioctl(struct file *filp,
2251 			    unsigned int cmd, unsigned long arg)
2252 {
2253 	return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2254 }
2255 
2256 #ifdef CONFIG_COMPAT
2257 static long vsock_dev_compat_ioctl(struct file *filp,
2258 				   unsigned int cmd, unsigned long arg)
2259 {
2260 	return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2261 }
2262 #endif
2263 
2264 static const struct file_operations vsock_device_ops = {
2265 	.owner		= THIS_MODULE,
2266 	.unlocked_ioctl	= vsock_dev_ioctl,
2267 #ifdef CONFIG_COMPAT
2268 	.compat_ioctl	= vsock_dev_compat_ioctl,
2269 #endif
2270 	.open		= nonseekable_open,
2271 };
2272 
2273 static struct miscdevice vsock_device = {
2274 	.name		= "vsock",
2275 	.fops		= &vsock_device_ops,
2276 };
2277 
2278 static int __init vsock_init(void)
2279 {
2280 	int err = 0;
2281 
2282 	vsock_init_tables();
2283 
2284 	vsock_proto.owner = THIS_MODULE;
2285 	vsock_device.minor = MISC_DYNAMIC_MINOR;
2286 	err = misc_register(&vsock_device);
2287 	if (err) {
2288 		pr_err("Failed to register misc device\n");
2289 		goto err_reset_transport;
2290 	}
2291 
2292 	err = proto_register(&vsock_proto, 1);	/* we want our slab */
2293 	if (err) {
2294 		pr_err("Cannot register vsock protocol\n");
2295 		goto err_deregister_misc;
2296 	}
2297 
2298 	err = sock_register(&vsock_family_ops);
2299 	if (err) {
2300 		pr_err("could not register af_vsock (%d) address family: %d\n",
2301 		       AF_VSOCK, err);
2302 		goto err_unregister_proto;
2303 	}
2304 
2305 	return 0;
2306 
2307 err_unregister_proto:
2308 	proto_unregister(&vsock_proto);
2309 err_deregister_misc:
2310 	misc_deregister(&vsock_device);
2311 err_reset_transport:
2312 	return err;
2313 }
2314 
2315 static void __exit vsock_exit(void)
2316 {
2317 	misc_deregister(&vsock_device);
2318 	sock_unregister(AF_VSOCK);
2319 	proto_unregister(&vsock_proto);
2320 }
2321 
2322 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2323 {
2324 	return vsk->transport;
2325 }
2326 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2327 
2328 int vsock_core_register(const struct vsock_transport *t, int features)
2329 {
2330 	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2331 	int err = mutex_lock_interruptible(&vsock_register_mutex);
2332 
2333 	if (err)
2334 		return err;
2335 
2336 	t_h2g = transport_h2g;
2337 	t_g2h = transport_g2h;
2338 	t_dgram = transport_dgram;
2339 	t_local = transport_local;
2340 
2341 	if (features & VSOCK_TRANSPORT_F_H2G) {
2342 		if (t_h2g) {
2343 			err = -EBUSY;
2344 			goto err_busy;
2345 		}
2346 		t_h2g = t;
2347 	}
2348 
2349 	if (features & VSOCK_TRANSPORT_F_G2H) {
2350 		if (t_g2h) {
2351 			err = -EBUSY;
2352 			goto err_busy;
2353 		}
2354 		t_g2h = t;
2355 	}
2356 
2357 	if (features & VSOCK_TRANSPORT_F_DGRAM) {
2358 		if (t_dgram) {
2359 			err = -EBUSY;
2360 			goto err_busy;
2361 		}
2362 		t_dgram = t;
2363 	}
2364 
2365 	if (features & VSOCK_TRANSPORT_F_LOCAL) {
2366 		if (t_local) {
2367 			err = -EBUSY;
2368 			goto err_busy;
2369 		}
2370 		t_local = t;
2371 	}
2372 
2373 	transport_h2g = t_h2g;
2374 	transport_g2h = t_g2h;
2375 	transport_dgram = t_dgram;
2376 	transport_local = t_local;
2377 
2378 err_busy:
2379 	mutex_unlock(&vsock_register_mutex);
2380 	return err;
2381 }
2382 EXPORT_SYMBOL_GPL(vsock_core_register);
2383 
2384 void vsock_core_unregister(const struct vsock_transport *t)
2385 {
2386 	mutex_lock(&vsock_register_mutex);
2387 
2388 	if (transport_h2g == t)
2389 		transport_h2g = NULL;
2390 
2391 	if (transport_g2h == t)
2392 		transport_g2h = NULL;
2393 
2394 	if (transport_dgram == t)
2395 		transport_dgram = NULL;
2396 
2397 	if (transport_local == t)
2398 		transport_local = NULL;
2399 
2400 	mutex_unlock(&vsock_register_mutex);
2401 }
2402 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2403 
2404 module_init(vsock_init);
2405 module_exit(vsock_exit);
2406 
2407 MODULE_AUTHOR("VMware, Inc.");
2408 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2409 MODULE_VERSION("1.0.2.0-k");
2410 MODULE_LICENSE("GPL v2");
2411