xref: /openbmc/linux/net/vmw_vsock/af_vsock.c (revision 29c37341)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VMware vSockets Driver
4  *
5  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
6  */
7 
8 /* Implementation notes:
9  *
10  * - There are two kinds of sockets: those created by user action (such as
11  * calling socket(2)) and those created by incoming connection request packets.
12  *
13  * - There are two "global" tables, one for bound sockets (sockets that have
14  * specified an address that they are responsible for) and one for connected
15  * sockets (sockets that have established a connection with another socket).
16  * These tables are "global" in that all sockets on the system are placed
17  * within them. - Note, though, that the bound table contains an extra entry
18  * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
19  * that list. The bound table is used solely for lookup of sockets when packets
20  * are received and that's not necessary for SOCK_DGRAM sockets since we create
21  * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
22  * sockets out of the bound hash buckets will reduce the chance of collisions
23  * when looking for SOCK_STREAM sockets and prevents us from having to check the
24  * socket type in the hash table lookups.
25  *
26  * - Sockets created by user action will either be "client" sockets that
27  * initiate a connection or "server" sockets that listen for connections; we do
28  * not support simultaneous connects (two "client" sockets connecting).
29  *
30  * - "Server" sockets are referred to as listener sockets throughout this
31  * implementation because they are in the TCP_LISTEN state.  When a
32  * connection request is received (the second kind of socket mentioned above),
33  * we create a new socket and refer to it as a pending socket.  These pending
34  * sockets are placed on the pending connection list of the listener socket.
35  * When future packets are received for the address the listener socket is
36  * bound to, we check if the source of the packet is from one that has an
37  * existing pending connection.  If it does, we process the packet for the
38  * pending socket.  When that socket reaches the connected state, it is removed
39  * from the listener socket's pending list and enqueued in the listener
40  * socket's accept queue.  Callers of accept(2) will accept connected sockets
41  * from the listener socket's accept queue.  If the socket cannot be accepted
42  * for some reason then it is marked rejected.  Once the connection is
43  * accepted, it is owned by the user process and the responsibility for cleanup
44  * falls with that user process.
45  *
46  * - It is possible that these pending sockets will never reach the connected
47  * state; in fact, we may never receive another packet after the connection
48  * request.  Because of this, we must schedule a cleanup function to run in the
49  * future, after some amount of time passes where a connection should have been
50  * established.  This function ensures that the socket is off all lists so it
51  * cannot be retrieved, then drops all references to the socket so it is cleaned
52  * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
53  * function will also cleanup rejected sockets, those that reach the connected
54  * state but leave it before they have been accepted.
55  *
56  * - Lock ordering for pending or accept queue sockets is:
57  *
58  *     lock_sock(listener);
59  *     lock_sock_nested(pending, SINGLE_DEPTH_NESTING);
60  *
61  * Using explicit nested locking keeps lockdep happy since normally only one
62  * lock of a given class may be taken at a time.
63  *
64  * - Sockets created by user action will be cleaned up when the user process
65  * calls close(2), causing our release implementation to be called. Our release
66  * implementation will perform some cleanup then drop the last reference so our
67  * sk_destruct implementation is invoked.  Our sk_destruct implementation will
68  * perform additional cleanup that's common for both types of sockets.
69  *
70  * - A socket's reference count is what ensures that the structure won't be
71  * freed.  Each entry in a list (such as the "global" bound and connected tables
72  * and the listener socket's pending list and connected queue) ensures a
73  * reference.  When we defer work until process context and pass a socket as our
74  * argument, we must ensure the reference count is increased to ensure the
75  * socket isn't freed before the function is run; the deferred function will
76  * then drop the reference.
77  *
78  * - sk->sk_state uses the TCP state constants because they are widely used by
79  * other address families and exposed to userspace tools like ss(8):
80  *
81  *   TCP_CLOSE - unconnected
82  *   TCP_SYN_SENT - connecting
83  *   TCP_ESTABLISHED - connected
84  *   TCP_CLOSING - disconnecting
85  *   TCP_LISTEN - listening
86  */
87 
88 #include <linux/types.h>
89 #include <linux/bitops.h>
90 #include <linux/cred.h>
91 #include <linux/init.h>
92 #include <linux/io.h>
93 #include <linux/kernel.h>
94 #include <linux/sched/signal.h>
95 #include <linux/kmod.h>
96 #include <linux/list.h>
97 #include <linux/miscdevice.h>
98 #include <linux/module.h>
99 #include <linux/mutex.h>
100 #include <linux/net.h>
101 #include <linux/poll.h>
102 #include <linux/random.h>
103 #include <linux/skbuff.h>
104 #include <linux/smp.h>
105 #include <linux/socket.h>
106 #include <linux/stddef.h>
107 #include <linux/unistd.h>
108 #include <linux/wait.h>
109 #include <linux/workqueue.h>
110 #include <net/sock.h>
111 #include <net/af_vsock.h>
112 
113 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
114 static void vsock_sk_destruct(struct sock *sk);
115 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
116 
117 /* Protocol family. */
118 static struct proto vsock_proto = {
119 	.name = "AF_VSOCK",
120 	.owner = THIS_MODULE,
121 	.obj_size = sizeof(struct vsock_sock),
122 };
123 
124 /* The default peer timeout indicates how long we will wait for a peer response
125  * to a control message.
126  */
127 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
128 
129 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
130 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
131 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
132 
133 /* Transport used for host->guest communication */
134 static const struct vsock_transport *transport_h2g;
135 /* Transport used for guest->host communication */
136 static const struct vsock_transport *transport_g2h;
137 /* Transport used for DGRAM communication */
138 static const struct vsock_transport *transport_dgram;
139 /* Transport used for local communication */
140 static const struct vsock_transport *transport_local;
141 static DEFINE_MUTEX(vsock_register_mutex);
142 
143 /**** UTILS ****/
144 
145 /* Each bound VSocket is stored in the bind hash table and each connected
146  * VSocket is stored in the connected hash table.
147  *
148  * Unbound sockets are all put on the same list attached to the end of the hash
149  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
150  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
151  * represents the list that addr hashes to).
152  *
153  * Specifically, we initialize the vsock_bind_table array to a size of
154  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
155  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
156  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
157  * mods with VSOCK_HASH_SIZE to ensure this.
158  */
159 #define MAX_PORT_RETRIES        24
160 
161 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
162 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
163 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
164 
165 /* XXX This can probably be implemented in a better way. */
166 #define VSOCK_CONN_HASH(src, dst)				\
167 	(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
168 #define vsock_connected_sockets(src, dst)		\
169 	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
170 #define vsock_connected_sockets_vsk(vsk)				\
171 	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
172 
173 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
174 EXPORT_SYMBOL_GPL(vsock_bind_table);
175 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
176 EXPORT_SYMBOL_GPL(vsock_connected_table);
177 DEFINE_SPINLOCK(vsock_table_lock);
178 EXPORT_SYMBOL_GPL(vsock_table_lock);
179 
180 /* Autobind this socket to the local address if necessary. */
181 static int vsock_auto_bind(struct vsock_sock *vsk)
182 {
183 	struct sock *sk = sk_vsock(vsk);
184 	struct sockaddr_vm local_addr;
185 
186 	if (vsock_addr_bound(&vsk->local_addr))
187 		return 0;
188 	vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
189 	return __vsock_bind(sk, &local_addr);
190 }
191 
192 static void vsock_init_tables(void)
193 {
194 	int i;
195 
196 	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
197 		INIT_LIST_HEAD(&vsock_bind_table[i]);
198 
199 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
200 		INIT_LIST_HEAD(&vsock_connected_table[i]);
201 }
202 
203 static void __vsock_insert_bound(struct list_head *list,
204 				 struct vsock_sock *vsk)
205 {
206 	sock_hold(&vsk->sk);
207 	list_add(&vsk->bound_table, list);
208 }
209 
210 static void __vsock_insert_connected(struct list_head *list,
211 				     struct vsock_sock *vsk)
212 {
213 	sock_hold(&vsk->sk);
214 	list_add(&vsk->connected_table, list);
215 }
216 
217 static void __vsock_remove_bound(struct vsock_sock *vsk)
218 {
219 	list_del_init(&vsk->bound_table);
220 	sock_put(&vsk->sk);
221 }
222 
223 static void __vsock_remove_connected(struct vsock_sock *vsk)
224 {
225 	list_del_init(&vsk->connected_table);
226 	sock_put(&vsk->sk);
227 }
228 
229 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
230 {
231 	struct vsock_sock *vsk;
232 
233 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
234 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
235 			return sk_vsock(vsk);
236 
237 		if (addr->svm_port == vsk->local_addr.svm_port &&
238 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
239 		     addr->svm_cid == VMADDR_CID_ANY))
240 			return sk_vsock(vsk);
241 	}
242 
243 	return NULL;
244 }
245 
246 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
247 						  struct sockaddr_vm *dst)
248 {
249 	struct vsock_sock *vsk;
250 
251 	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
252 			    connected_table) {
253 		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
254 		    dst->svm_port == vsk->local_addr.svm_port) {
255 			return sk_vsock(vsk);
256 		}
257 	}
258 
259 	return NULL;
260 }
261 
262 static void vsock_insert_unbound(struct vsock_sock *vsk)
263 {
264 	spin_lock_bh(&vsock_table_lock);
265 	__vsock_insert_bound(vsock_unbound_sockets, vsk);
266 	spin_unlock_bh(&vsock_table_lock);
267 }
268 
269 void vsock_insert_connected(struct vsock_sock *vsk)
270 {
271 	struct list_head *list = vsock_connected_sockets(
272 		&vsk->remote_addr, &vsk->local_addr);
273 
274 	spin_lock_bh(&vsock_table_lock);
275 	__vsock_insert_connected(list, vsk);
276 	spin_unlock_bh(&vsock_table_lock);
277 }
278 EXPORT_SYMBOL_GPL(vsock_insert_connected);
279 
280 void vsock_remove_bound(struct vsock_sock *vsk)
281 {
282 	spin_lock_bh(&vsock_table_lock);
283 	if (__vsock_in_bound_table(vsk))
284 		__vsock_remove_bound(vsk);
285 	spin_unlock_bh(&vsock_table_lock);
286 }
287 EXPORT_SYMBOL_GPL(vsock_remove_bound);
288 
289 void vsock_remove_connected(struct vsock_sock *vsk)
290 {
291 	spin_lock_bh(&vsock_table_lock);
292 	if (__vsock_in_connected_table(vsk))
293 		__vsock_remove_connected(vsk);
294 	spin_unlock_bh(&vsock_table_lock);
295 }
296 EXPORT_SYMBOL_GPL(vsock_remove_connected);
297 
298 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
299 {
300 	struct sock *sk;
301 
302 	spin_lock_bh(&vsock_table_lock);
303 	sk = __vsock_find_bound_socket(addr);
304 	if (sk)
305 		sock_hold(sk);
306 
307 	spin_unlock_bh(&vsock_table_lock);
308 
309 	return sk;
310 }
311 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
312 
313 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
314 					 struct sockaddr_vm *dst)
315 {
316 	struct sock *sk;
317 
318 	spin_lock_bh(&vsock_table_lock);
319 	sk = __vsock_find_connected_socket(src, dst);
320 	if (sk)
321 		sock_hold(sk);
322 
323 	spin_unlock_bh(&vsock_table_lock);
324 
325 	return sk;
326 }
327 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
328 
329 void vsock_remove_sock(struct vsock_sock *vsk)
330 {
331 	vsock_remove_bound(vsk);
332 	vsock_remove_connected(vsk);
333 }
334 EXPORT_SYMBOL_GPL(vsock_remove_sock);
335 
336 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
337 {
338 	int i;
339 
340 	spin_lock_bh(&vsock_table_lock);
341 
342 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
343 		struct vsock_sock *vsk;
344 		list_for_each_entry(vsk, &vsock_connected_table[i],
345 				    connected_table)
346 			fn(sk_vsock(vsk));
347 	}
348 
349 	spin_unlock_bh(&vsock_table_lock);
350 }
351 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
352 
353 void vsock_add_pending(struct sock *listener, struct sock *pending)
354 {
355 	struct vsock_sock *vlistener;
356 	struct vsock_sock *vpending;
357 
358 	vlistener = vsock_sk(listener);
359 	vpending = vsock_sk(pending);
360 
361 	sock_hold(pending);
362 	sock_hold(listener);
363 	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
364 }
365 EXPORT_SYMBOL_GPL(vsock_add_pending);
366 
367 void vsock_remove_pending(struct sock *listener, struct sock *pending)
368 {
369 	struct vsock_sock *vpending = vsock_sk(pending);
370 
371 	list_del_init(&vpending->pending_links);
372 	sock_put(listener);
373 	sock_put(pending);
374 }
375 EXPORT_SYMBOL_GPL(vsock_remove_pending);
376 
377 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
378 {
379 	struct vsock_sock *vlistener;
380 	struct vsock_sock *vconnected;
381 
382 	vlistener = vsock_sk(listener);
383 	vconnected = vsock_sk(connected);
384 
385 	sock_hold(connected);
386 	sock_hold(listener);
387 	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
388 }
389 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
390 
391 static bool vsock_use_local_transport(unsigned int remote_cid)
392 {
393 	if (!transport_local)
394 		return false;
395 
396 	if (remote_cid == VMADDR_CID_LOCAL)
397 		return true;
398 
399 	if (transport_g2h) {
400 		return remote_cid == transport_g2h->get_local_cid();
401 	} else {
402 		return remote_cid == VMADDR_CID_HOST;
403 	}
404 }
405 
406 static void vsock_deassign_transport(struct vsock_sock *vsk)
407 {
408 	if (!vsk->transport)
409 		return;
410 
411 	vsk->transport->destruct(vsk);
412 	module_put(vsk->transport->module);
413 	vsk->transport = NULL;
414 }
415 
416 /* Assign a transport to a socket and call the .init transport callback.
417  *
418  * Note: for stream socket this must be called when vsk->remote_addr is set
419  * (e.g. during the connect() or when a connection request on a listener
420  * socket is received).
421  * The vsk->remote_addr is used to decide which transport to use:
422  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
423  *    g2h is not loaded, will use local transport;
424  *  - remote CID <= VMADDR_CID_HOST will use guest->host transport;
425  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
426  */
427 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
428 {
429 	const struct vsock_transport *new_transport;
430 	struct sock *sk = sk_vsock(vsk);
431 	unsigned int remote_cid = vsk->remote_addr.svm_cid;
432 	int ret;
433 
434 	switch (sk->sk_type) {
435 	case SOCK_DGRAM:
436 		new_transport = transport_dgram;
437 		break;
438 	case SOCK_STREAM:
439 		if (vsock_use_local_transport(remote_cid))
440 			new_transport = transport_local;
441 		else if (remote_cid <= VMADDR_CID_HOST)
442 			new_transport = transport_g2h;
443 		else
444 			new_transport = transport_h2g;
445 		break;
446 	default:
447 		return -ESOCKTNOSUPPORT;
448 	}
449 
450 	if (vsk->transport) {
451 		if (vsk->transport == new_transport)
452 			return 0;
453 
454 		/* transport->release() must be called with sock lock acquired.
455 		 * This path can only be taken during vsock_stream_connect(),
456 		 * where we have already held the sock lock.
457 		 * In the other cases, this function is called on a new socket
458 		 * which is not assigned to any transport.
459 		 */
460 		vsk->transport->release(vsk);
461 		vsock_deassign_transport(vsk);
462 	}
463 
464 	/* We increase the module refcnt to prevent the transport unloading
465 	 * while there are open sockets assigned to it.
466 	 */
467 	if (!new_transport || !try_module_get(new_transport->module))
468 		return -ENODEV;
469 
470 	ret = new_transport->init(vsk, psk);
471 	if (ret) {
472 		module_put(new_transport->module);
473 		return ret;
474 	}
475 
476 	vsk->transport = new_transport;
477 
478 	return 0;
479 }
480 EXPORT_SYMBOL_GPL(vsock_assign_transport);
481 
482 bool vsock_find_cid(unsigned int cid)
483 {
484 	if (transport_g2h && cid == transport_g2h->get_local_cid())
485 		return true;
486 
487 	if (transport_h2g && cid == VMADDR_CID_HOST)
488 		return true;
489 
490 	if (transport_local && cid == VMADDR_CID_LOCAL)
491 		return true;
492 
493 	return false;
494 }
495 EXPORT_SYMBOL_GPL(vsock_find_cid);
496 
497 static struct sock *vsock_dequeue_accept(struct sock *listener)
498 {
499 	struct vsock_sock *vlistener;
500 	struct vsock_sock *vconnected;
501 
502 	vlistener = vsock_sk(listener);
503 
504 	if (list_empty(&vlistener->accept_queue))
505 		return NULL;
506 
507 	vconnected = list_entry(vlistener->accept_queue.next,
508 				struct vsock_sock, accept_queue);
509 
510 	list_del_init(&vconnected->accept_queue);
511 	sock_put(listener);
512 	/* The caller will need a reference on the connected socket so we let
513 	 * it call sock_put().
514 	 */
515 
516 	return sk_vsock(vconnected);
517 }
518 
519 static bool vsock_is_accept_queue_empty(struct sock *sk)
520 {
521 	struct vsock_sock *vsk = vsock_sk(sk);
522 	return list_empty(&vsk->accept_queue);
523 }
524 
525 static bool vsock_is_pending(struct sock *sk)
526 {
527 	struct vsock_sock *vsk = vsock_sk(sk);
528 	return !list_empty(&vsk->pending_links);
529 }
530 
531 static int vsock_send_shutdown(struct sock *sk, int mode)
532 {
533 	struct vsock_sock *vsk = vsock_sk(sk);
534 
535 	if (!vsk->transport)
536 		return -ENODEV;
537 
538 	return vsk->transport->shutdown(vsk, mode);
539 }
540 
541 static void vsock_pending_work(struct work_struct *work)
542 {
543 	struct sock *sk;
544 	struct sock *listener;
545 	struct vsock_sock *vsk;
546 	bool cleanup;
547 
548 	vsk = container_of(work, struct vsock_sock, pending_work.work);
549 	sk = sk_vsock(vsk);
550 	listener = vsk->listener;
551 	cleanup = true;
552 
553 	lock_sock(listener);
554 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
555 
556 	if (vsock_is_pending(sk)) {
557 		vsock_remove_pending(listener, sk);
558 
559 		sk_acceptq_removed(listener);
560 	} else if (!vsk->rejected) {
561 		/* We are not on the pending list and accept() did not reject
562 		 * us, so we must have been accepted by our user process.  We
563 		 * just need to drop our references to the sockets and be on
564 		 * our way.
565 		 */
566 		cleanup = false;
567 		goto out;
568 	}
569 
570 	/* We need to remove ourself from the global connected sockets list so
571 	 * incoming packets can't find this socket, and to reduce the reference
572 	 * count.
573 	 */
574 	vsock_remove_connected(vsk);
575 
576 	sk->sk_state = TCP_CLOSE;
577 
578 out:
579 	release_sock(sk);
580 	release_sock(listener);
581 	if (cleanup)
582 		sock_put(sk);
583 
584 	sock_put(sk);
585 	sock_put(listener);
586 }
587 
588 /**** SOCKET OPERATIONS ****/
589 
590 static int __vsock_bind_stream(struct vsock_sock *vsk,
591 			       struct sockaddr_vm *addr)
592 {
593 	static u32 port;
594 	struct sockaddr_vm new_addr;
595 
596 	if (!port)
597 		port = LAST_RESERVED_PORT + 1 +
598 			prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
599 
600 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
601 
602 	if (addr->svm_port == VMADDR_PORT_ANY) {
603 		bool found = false;
604 		unsigned int i;
605 
606 		for (i = 0; i < MAX_PORT_RETRIES; i++) {
607 			if (port <= LAST_RESERVED_PORT)
608 				port = LAST_RESERVED_PORT + 1;
609 
610 			new_addr.svm_port = port++;
611 
612 			if (!__vsock_find_bound_socket(&new_addr)) {
613 				found = true;
614 				break;
615 			}
616 		}
617 
618 		if (!found)
619 			return -EADDRNOTAVAIL;
620 	} else {
621 		/* If port is in reserved range, ensure caller
622 		 * has necessary privileges.
623 		 */
624 		if (addr->svm_port <= LAST_RESERVED_PORT &&
625 		    !capable(CAP_NET_BIND_SERVICE)) {
626 			return -EACCES;
627 		}
628 
629 		if (__vsock_find_bound_socket(&new_addr))
630 			return -EADDRINUSE;
631 	}
632 
633 	vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
634 
635 	/* Remove stream sockets from the unbound list and add them to the hash
636 	 * table for easy lookup by its address.  The unbound list is simply an
637 	 * extra entry at the end of the hash table, a trick used by AF_UNIX.
638 	 */
639 	__vsock_remove_bound(vsk);
640 	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
641 
642 	return 0;
643 }
644 
645 static int __vsock_bind_dgram(struct vsock_sock *vsk,
646 			      struct sockaddr_vm *addr)
647 {
648 	return vsk->transport->dgram_bind(vsk, addr);
649 }
650 
651 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
652 {
653 	struct vsock_sock *vsk = vsock_sk(sk);
654 	int retval;
655 
656 	/* First ensure this socket isn't already bound. */
657 	if (vsock_addr_bound(&vsk->local_addr))
658 		return -EINVAL;
659 
660 	/* Now bind to the provided address or select appropriate values if
661 	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
662 	 * like AF_INET prevents binding to a non-local IP address (in most
663 	 * cases), we only allow binding to a local CID.
664 	 */
665 	if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
666 		return -EADDRNOTAVAIL;
667 
668 	switch (sk->sk_socket->type) {
669 	case SOCK_STREAM:
670 		spin_lock_bh(&vsock_table_lock);
671 		retval = __vsock_bind_stream(vsk, addr);
672 		spin_unlock_bh(&vsock_table_lock);
673 		break;
674 
675 	case SOCK_DGRAM:
676 		retval = __vsock_bind_dgram(vsk, addr);
677 		break;
678 
679 	default:
680 		retval = -EINVAL;
681 		break;
682 	}
683 
684 	return retval;
685 }
686 
687 static void vsock_connect_timeout(struct work_struct *work);
688 
689 static struct sock *__vsock_create(struct net *net,
690 				   struct socket *sock,
691 				   struct sock *parent,
692 				   gfp_t priority,
693 				   unsigned short type,
694 				   int kern)
695 {
696 	struct sock *sk;
697 	struct vsock_sock *psk;
698 	struct vsock_sock *vsk;
699 
700 	sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
701 	if (!sk)
702 		return NULL;
703 
704 	sock_init_data(sock, sk);
705 
706 	/* sk->sk_type is normally set in sock_init_data, but only if sock is
707 	 * non-NULL. We make sure that our sockets always have a type by
708 	 * setting it here if needed.
709 	 */
710 	if (!sock)
711 		sk->sk_type = type;
712 
713 	vsk = vsock_sk(sk);
714 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
715 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
716 
717 	sk->sk_destruct = vsock_sk_destruct;
718 	sk->sk_backlog_rcv = vsock_queue_rcv_skb;
719 	sock_reset_flag(sk, SOCK_DONE);
720 
721 	INIT_LIST_HEAD(&vsk->bound_table);
722 	INIT_LIST_HEAD(&vsk->connected_table);
723 	vsk->listener = NULL;
724 	INIT_LIST_HEAD(&vsk->pending_links);
725 	INIT_LIST_HEAD(&vsk->accept_queue);
726 	vsk->rejected = false;
727 	vsk->sent_request = false;
728 	vsk->ignore_connecting_rst = false;
729 	vsk->peer_shutdown = 0;
730 	INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
731 	INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
732 
733 	psk = parent ? vsock_sk(parent) : NULL;
734 	if (parent) {
735 		vsk->trusted = psk->trusted;
736 		vsk->owner = get_cred(psk->owner);
737 		vsk->connect_timeout = psk->connect_timeout;
738 		vsk->buffer_size = psk->buffer_size;
739 		vsk->buffer_min_size = psk->buffer_min_size;
740 		vsk->buffer_max_size = psk->buffer_max_size;
741 	} else {
742 		vsk->trusted = capable(CAP_NET_ADMIN);
743 		vsk->owner = get_current_cred();
744 		vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
745 		vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
746 		vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
747 		vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
748 	}
749 
750 	return sk;
751 }
752 
753 static void __vsock_release(struct sock *sk, int level)
754 {
755 	if (sk) {
756 		struct sock *pending;
757 		struct vsock_sock *vsk;
758 
759 		vsk = vsock_sk(sk);
760 		pending = NULL;	/* Compiler warning. */
761 
762 		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
763 		 * version to avoid the warning "possible recursive locking
764 		 * detected". When "level" is 0, lock_sock_nested(sk, level)
765 		 * is the same as lock_sock(sk).
766 		 */
767 		lock_sock_nested(sk, level);
768 
769 		if (vsk->transport)
770 			vsk->transport->release(vsk);
771 		else if (sk->sk_type == SOCK_STREAM)
772 			vsock_remove_sock(vsk);
773 
774 		sock_orphan(sk);
775 		sk->sk_shutdown = SHUTDOWN_MASK;
776 
777 		skb_queue_purge(&sk->sk_receive_queue);
778 
779 		/* Clean up any sockets that never were accepted. */
780 		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
781 			__vsock_release(pending, SINGLE_DEPTH_NESTING);
782 			sock_put(pending);
783 		}
784 
785 		release_sock(sk);
786 		sock_put(sk);
787 	}
788 }
789 
790 static void vsock_sk_destruct(struct sock *sk)
791 {
792 	struct vsock_sock *vsk = vsock_sk(sk);
793 
794 	vsock_deassign_transport(vsk);
795 
796 	/* When clearing these addresses, there's no need to set the family and
797 	 * possibly register the address family with the kernel.
798 	 */
799 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
800 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
801 
802 	put_cred(vsk->owner);
803 }
804 
805 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
806 {
807 	int err;
808 
809 	err = sock_queue_rcv_skb(sk, skb);
810 	if (err)
811 		kfree_skb(skb);
812 
813 	return err;
814 }
815 
816 struct sock *vsock_create_connected(struct sock *parent)
817 {
818 	return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
819 			      parent->sk_type, 0);
820 }
821 EXPORT_SYMBOL_GPL(vsock_create_connected);
822 
823 s64 vsock_stream_has_data(struct vsock_sock *vsk)
824 {
825 	return vsk->transport->stream_has_data(vsk);
826 }
827 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
828 
829 s64 vsock_stream_has_space(struct vsock_sock *vsk)
830 {
831 	return vsk->transport->stream_has_space(vsk);
832 }
833 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
834 
835 static int vsock_release(struct socket *sock)
836 {
837 	__vsock_release(sock->sk, 0);
838 	sock->sk = NULL;
839 	sock->state = SS_FREE;
840 
841 	return 0;
842 }
843 
844 static int
845 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
846 {
847 	int err;
848 	struct sock *sk;
849 	struct sockaddr_vm *vm_addr;
850 
851 	sk = sock->sk;
852 
853 	if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
854 		return -EINVAL;
855 
856 	lock_sock(sk);
857 	err = __vsock_bind(sk, vm_addr);
858 	release_sock(sk);
859 
860 	return err;
861 }
862 
863 static int vsock_getname(struct socket *sock,
864 			 struct sockaddr *addr, int peer)
865 {
866 	int err;
867 	struct sock *sk;
868 	struct vsock_sock *vsk;
869 	struct sockaddr_vm *vm_addr;
870 
871 	sk = sock->sk;
872 	vsk = vsock_sk(sk);
873 	err = 0;
874 
875 	lock_sock(sk);
876 
877 	if (peer) {
878 		if (sock->state != SS_CONNECTED) {
879 			err = -ENOTCONN;
880 			goto out;
881 		}
882 		vm_addr = &vsk->remote_addr;
883 	} else {
884 		vm_addr = &vsk->local_addr;
885 	}
886 
887 	if (!vm_addr) {
888 		err = -EINVAL;
889 		goto out;
890 	}
891 
892 	/* sys_getsockname() and sys_getpeername() pass us a
893 	 * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
894 	 * that macro is defined in socket.c instead of .h, so we hardcode its
895 	 * value here.
896 	 */
897 	BUILD_BUG_ON(sizeof(*vm_addr) > 128);
898 	memcpy(addr, vm_addr, sizeof(*vm_addr));
899 	err = sizeof(*vm_addr);
900 
901 out:
902 	release_sock(sk);
903 	return err;
904 }
905 
906 static int vsock_shutdown(struct socket *sock, int mode)
907 {
908 	int err;
909 	struct sock *sk;
910 
911 	/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
912 	 * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
913 	 * here like the other address families do.  Note also that the
914 	 * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
915 	 * which is what we want.
916 	 */
917 	mode++;
918 
919 	if ((mode & ~SHUTDOWN_MASK) || !mode)
920 		return -EINVAL;
921 
922 	/* If this is a STREAM socket and it is not connected then bail out
923 	 * immediately.  If it is a DGRAM socket then we must first kick the
924 	 * socket so that it wakes up from any sleeping calls, for example
925 	 * recv(), and then afterwards return the error.
926 	 */
927 
928 	sk = sock->sk;
929 	if (sock->state == SS_UNCONNECTED) {
930 		err = -ENOTCONN;
931 		if (sk->sk_type == SOCK_STREAM)
932 			return err;
933 	} else {
934 		sock->state = SS_DISCONNECTING;
935 		err = 0;
936 	}
937 
938 	/* Receive and send shutdowns are treated alike. */
939 	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
940 	if (mode) {
941 		lock_sock(sk);
942 		sk->sk_shutdown |= mode;
943 		sk->sk_state_change(sk);
944 		release_sock(sk);
945 
946 		if (sk->sk_type == SOCK_STREAM) {
947 			sock_reset_flag(sk, SOCK_DONE);
948 			vsock_send_shutdown(sk, mode);
949 		}
950 	}
951 
952 	return err;
953 }
954 
955 static __poll_t vsock_poll(struct file *file, struct socket *sock,
956 			       poll_table *wait)
957 {
958 	struct sock *sk;
959 	__poll_t mask;
960 	struct vsock_sock *vsk;
961 
962 	sk = sock->sk;
963 	vsk = vsock_sk(sk);
964 
965 	poll_wait(file, sk_sleep(sk), wait);
966 	mask = 0;
967 
968 	if (sk->sk_err)
969 		/* Signify that there has been an error on this socket. */
970 		mask |= EPOLLERR;
971 
972 	/* INET sockets treat local write shutdown and peer write shutdown as a
973 	 * case of EPOLLHUP set.
974 	 */
975 	if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
976 	    ((sk->sk_shutdown & SEND_SHUTDOWN) &&
977 	     (vsk->peer_shutdown & SEND_SHUTDOWN))) {
978 		mask |= EPOLLHUP;
979 	}
980 
981 	if (sk->sk_shutdown & RCV_SHUTDOWN ||
982 	    vsk->peer_shutdown & SEND_SHUTDOWN) {
983 		mask |= EPOLLRDHUP;
984 	}
985 
986 	if (sock->type == SOCK_DGRAM) {
987 		/* For datagram sockets we can read if there is something in
988 		 * the queue and write as long as the socket isn't shutdown for
989 		 * sending.
990 		 */
991 		if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
992 		    (sk->sk_shutdown & RCV_SHUTDOWN)) {
993 			mask |= EPOLLIN | EPOLLRDNORM;
994 		}
995 
996 		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
997 			mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
998 
999 	} else if (sock->type == SOCK_STREAM) {
1000 		const struct vsock_transport *transport = vsk->transport;
1001 		lock_sock(sk);
1002 
1003 		/* Listening sockets that have connections in their accept
1004 		 * queue can be read.
1005 		 */
1006 		if (sk->sk_state == TCP_LISTEN
1007 		    && !vsock_is_accept_queue_empty(sk))
1008 			mask |= EPOLLIN | EPOLLRDNORM;
1009 
1010 		/* If there is something in the queue then we can read. */
1011 		if (transport && transport->stream_is_active(vsk) &&
1012 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1013 			bool data_ready_now = false;
1014 			int ret = transport->notify_poll_in(
1015 					vsk, 1, &data_ready_now);
1016 			if (ret < 0) {
1017 				mask |= EPOLLERR;
1018 			} else {
1019 				if (data_ready_now)
1020 					mask |= EPOLLIN | EPOLLRDNORM;
1021 
1022 			}
1023 		}
1024 
1025 		/* Sockets whose connections have been closed, reset, or
1026 		 * terminated should also be considered read, and we check the
1027 		 * shutdown flag for that.
1028 		 */
1029 		if (sk->sk_shutdown & RCV_SHUTDOWN ||
1030 		    vsk->peer_shutdown & SEND_SHUTDOWN) {
1031 			mask |= EPOLLIN | EPOLLRDNORM;
1032 		}
1033 
1034 		/* Connected sockets that can produce data can be written. */
1035 		if (transport && sk->sk_state == TCP_ESTABLISHED) {
1036 			if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1037 				bool space_avail_now = false;
1038 				int ret = transport->notify_poll_out(
1039 						vsk, 1, &space_avail_now);
1040 				if (ret < 0) {
1041 					mask |= EPOLLERR;
1042 				} else {
1043 					if (space_avail_now)
1044 						/* Remove EPOLLWRBAND since INET
1045 						 * sockets are not setting it.
1046 						 */
1047 						mask |= EPOLLOUT | EPOLLWRNORM;
1048 
1049 				}
1050 			}
1051 		}
1052 
1053 		/* Simulate INET socket poll behaviors, which sets
1054 		 * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1055 		 * but local send is not shutdown.
1056 		 */
1057 		if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1058 			if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1059 				mask |= EPOLLOUT | EPOLLWRNORM;
1060 
1061 		}
1062 
1063 		release_sock(sk);
1064 	}
1065 
1066 	return mask;
1067 }
1068 
1069 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1070 			       size_t len)
1071 {
1072 	int err;
1073 	struct sock *sk;
1074 	struct vsock_sock *vsk;
1075 	struct sockaddr_vm *remote_addr;
1076 	const struct vsock_transport *transport;
1077 
1078 	if (msg->msg_flags & MSG_OOB)
1079 		return -EOPNOTSUPP;
1080 
1081 	/* For now, MSG_DONTWAIT is always assumed... */
1082 	err = 0;
1083 	sk = sock->sk;
1084 	vsk = vsock_sk(sk);
1085 	transport = vsk->transport;
1086 
1087 	lock_sock(sk);
1088 
1089 	err = vsock_auto_bind(vsk);
1090 	if (err)
1091 		goto out;
1092 
1093 
1094 	/* If the provided message contains an address, use that.  Otherwise
1095 	 * fall back on the socket's remote handle (if it has been connected).
1096 	 */
1097 	if (msg->msg_name &&
1098 	    vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1099 			    &remote_addr) == 0) {
1100 		/* Ensure this address is of the right type and is a valid
1101 		 * destination.
1102 		 */
1103 
1104 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1105 			remote_addr->svm_cid = transport->get_local_cid();
1106 
1107 		if (!vsock_addr_bound(remote_addr)) {
1108 			err = -EINVAL;
1109 			goto out;
1110 		}
1111 	} else if (sock->state == SS_CONNECTED) {
1112 		remote_addr = &vsk->remote_addr;
1113 
1114 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1115 			remote_addr->svm_cid = transport->get_local_cid();
1116 
1117 		/* XXX Should connect() or this function ensure remote_addr is
1118 		 * bound?
1119 		 */
1120 		if (!vsock_addr_bound(&vsk->remote_addr)) {
1121 			err = -EINVAL;
1122 			goto out;
1123 		}
1124 	} else {
1125 		err = -EINVAL;
1126 		goto out;
1127 	}
1128 
1129 	if (!transport->dgram_allow(remote_addr->svm_cid,
1130 				    remote_addr->svm_port)) {
1131 		err = -EINVAL;
1132 		goto out;
1133 	}
1134 
1135 	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1136 
1137 out:
1138 	release_sock(sk);
1139 	return err;
1140 }
1141 
1142 static int vsock_dgram_connect(struct socket *sock,
1143 			       struct sockaddr *addr, int addr_len, int flags)
1144 {
1145 	int err;
1146 	struct sock *sk;
1147 	struct vsock_sock *vsk;
1148 	struct sockaddr_vm *remote_addr;
1149 
1150 	sk = sock->sk;
1151 	vsk = vsock_sk(sk);
1152 
1153 	err = vsock_addr_cast(addr, addr_len, &remote_addr);
1154 	if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1155 		lock_sock(sk);
1156 		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1157 				VMADDR_PORT_ANY);
1158 		sock->state = SS_UNCONNECTED;
1159 		release_sock(sk);
1160 		return 0;
1161 	} else if (err != 0)
1162 		return -EINVAL;
1163 
1164 	lock_sock(sk);
1165 
1166 	err = vsock_auto_bind(vsk);
1167 	if (err)
1168 		goto out;
1169 
1170 	if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1171 					 remote_addr->svm_port)) {
1172 		err = -EINVAL;
1173 		goto out;
1174 	}
1175 
1176 	memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1177 	sock->state = SS_CONNECTED;
1178 
1179 out:
1180 	release_sock(sk);
1181 	return err;
1182 }
1183 
1184 static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1185 			       size_t len, int flags)
1186 {
1187 	struct vsock_sock *vsk = vsock_sk(sock->sk);
1188 
1189 	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1190 }
1191 
1192 static const struct proto_ops vsock_dgram_ops = {
1193 	.family = PF_VSOCK,
1194 	.owner = THIS_MODULE,
1195 	.release = vsock_release,
1196 	.bind = vsock_bind,
1197 	.connect = vsock_dgram_connect,
1198 	.socketpair = sock_no_socketpair,
1199 	.accept = sock_no_accept,
1200 	.getname = vsock_getname,
1201 	.poll = vsock_poll,
1202 	.ioctl = sock_no_ioctl,
1203 	.listen = sock_no_listen,
1204 	.shutdown = vsock_shutdown,
1205 	.sendmsg = vsock_dgram_sendmsg,
1206 	.recvmsg = vsock_dgram_recvmsg,
1207 	.mmap = sock_no_mmap,
1208 	.sendpage = sock_no_sendpage,
1209 };
1210 
1211 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1212 {
1213 	const struct vsock_transport *transport = vsk->transport;
1214 
1215 	if (!transport->cancel_pkt)
1216 		return -EOPNOTSUPP;
1217 
1218 	return transport->cancel_pkt(vsk);
1219 }
1220 
1221 static void vsock_connect_timeout(struct work_struct *work)
1222 {
1223 	struct sock *sk;
1224 	struct vsock_sock *vsk;
1225 	int cancel = 0;
1226 
1227 	vsk = container_of(work, struct vsock_sock, connect_work.work);
1228 	sk = sk_vsock(vsk);
1229 
1230 	lock_sock(sk);
1231 	if (sk->sk_state == TCP_SYN_SENT &&
1232 	    (sk->sk_shutdown != SHUTDOWN_MASK)) {
1233 		sk->sk_state = TCP_CLOSE;
1234 		sk->sk_err = ETIMEDOUT;
1235 		sk->sk_error_report(sk);
1236 		cancel = 1;
1237 	}
1238 	release_sock(sk);
1239 	if (cancel)
1240 		vsock_transport_cancel_pkt(vsk);
1241 
1242 	sock_put(sk);
1243 }
1244 
1245 static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
1246 				int addr_len, int flags)
1247 {
1248 	int err;
1249 	struct sock *sk;
1250 	struct vsock_sock *vsk;
1251 	const struct vsock_transport *transport;
1252 	struct sockaddr_vm *remote_addr;
1253 	long timeout;
1254 	DEFINE_WAIT(wait);
1255 
1256 	err = 0;
1257 	sk = sock->sk;
1258 	vsk = vsock_sk(sk);
1259 
1260 	lock_sock(sk);
1261 
1262 	/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1263 	switch (sock->state) {
1264 	case SS_CONNECTED:
1265 		err = -EISCONN;
1266 		goto out;
1267 	case SS_DISCONNECTING:
1268 		err = -EINVAL;
1269 		goto out;
1270 	case SS_CONNECTING:
1271 		/* This continues on so we can move sock into the SS_CONNECTED
1272 		 * state once the connection has completed (at which point err
1273 		 * will be set to zero also).  Otherwise, we will either wait
1274 		 * for the connection or return -EALREADY should this be a
1275 		 * non-blocking call.
1276 		 */
1277 		err = -EALREADY;
1278 		break;
1279 	default:
1280 		if ((sk->sk_state == TCP_LISTEN) ||
1281 		    vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1282 			err = -EINVAL;
1283 			goto out;
1284 		}
1285 
1286 		/* Set the remote address that we are connecting to. */
1287 		memcpy(&vsk->remote_addr, remote_addr,
1288 		       sizeof(vsk->remote_addr));
1289 
1290 		err = vsock_assign_transport(vsk, NULL);
1291 		if (err)
1292 			goto out;
1293 
1294 		transport = vsk->transport;
1295 
1296 		/* The hypervisor and well-known contexts do not have socket
1297 		 * endpoints.
1298 		 */
1299 		if (!transport ||
1300 		    !transport->stream_allow(remote_addr->svm_cid,
1301 					     remote_addr->svm_port)) {
1302 			err = -ENETUNREACH;
1303 			goto out;
1304 		}
1305 
1306 		err = vsock_auto_bind(vsk);
1307 		if (err)
1308 			goto out;
1309 
1310 		sk->sk_state = TCP_SYN_SENT;
1311 
1312 		err = transport->connect(vsk);
1313 		if (err < 0)
1314 			goto out;
1315 
1316 		/* Mark sock as connecting and set the error code to in
1317 		 * progress in case this is a non-blocking connect.
1318 		 */
1319 		sock->state = SS_CONNECTING;
1320 		err = -EINPROGRESS;
1321 	}
1322 
1323 	/* The receive path will handle all communication until we are able to
1324 	 * enter the connected state.  Here we wait for the connection to be
1325 	 * completed or a notification of an error.
1326 	 */
1327 	timeout = vsk->connect_timeout;
1328 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1329 
1330 	while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1331 		if (flags & O_NONBLOCK) {
1332 			/* If we're not going to block, we schedule a timeout
1333 			 * function to generate a timeout on the connection
1334 			 * attempt, in case the peer doesn't respond in a
1335 			 * timely manner. We hold on to the socket until the
1336 			 * timeout fires.
1337 			 */
1338 			sock_hold(sk);
1339 			schedule_delayed_work(&vsk->connect_work, timeout);
1340 
1341 			/* Skip ahead to preserve error code set above. */
1342 			goto out_wait;
1343 		}
1344 
1345 		release_sock(sk);
1346 		timeout = schedule_timeout(timeout);
1347 		lock_sock(sk);
1348 
1349 		if (signal_pending(current)) {
1350 			err = sock_intr_errno(timeout);
1351 			sk->sk_state = TCP_CLOSE;
1352 			sock->state = SS_UNCONNECTED;
1353 			vsock_transport_cancel_pkt(vsk);
1354 			goto out_wait;
1355 		} else if (timeout == 0) {
1356 			err = -ETIMEDOUT;
1357 			sk->sk_state = TCP_CLOSE;
1358 			sock->state = SS_UNCONNECTED;
1359 			vsock_transport_cancel_pkt(vsk);
1360 			goto out_wait;
1361 		}
1362 
1363 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1364 	}
1365 
1366 	if (sk->sk_err) {
1367 		err = -sk->sk_err;
1368 		sk->sk_state = TCP_CLOSE;
1369 		sock->state = SS_UNCONNECTED;
1370 	} else {
1371 		err = 0;
1372 	}
1373 
1374 out_wait:
1375 	finish_wait(sk_sleep(sk), &wait);
1376 out:
1377 	release_sock(sk);
1378 	return err;
1379 }
1380 
1381 static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
1382 			bool kern)
1383 {
1384 	struct sock *listener;
1385 	int err;
1386 	struct sock *connected;
1387 	struct vsock_sock *vconnected;
1388 	long timeout;
1389 	DEFINE_WAIT(wait);
1390 
1391 	err = 0;
1392 	listener = sock->sk;
1393 
1394 	lock_sock(listener);
1395 
1396 	if (sock->type != SOCK_STREAM) {
1397 		err = -EOPNOTSUPP;
1398 		goto out;
1399 	}
1400 
1401 	if (listener->sk_state != TCP_LISTEN) {
1402 		err = -EINVAL;
1403 		goto out;
1404 	}
1405 
1406 	/* Wait for children sockets to appear; these are the new sockets
1407 	 * created upon connection establishment.
1408 	 */
1409 	timeout = sock_rcvtimeo(listener, flags & O_NONBLOCK);
1410 	prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1411 
1412 	while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1413 	       listener->sk_err == 0) {
1414 		release_sock(listener);
1415 		timeout = schedule_timeout(timeout);
1416 		finish_wait(sk_sleep(listener), &wait);
1417 		lock_sock(listener);
1418 
1419 		if (signal_pending(current)) {
1420 			err = sock_intr_errno(timeout);
1421 			goto out;
1422 		} else if (timeout == 0) {
1423 			err = -EAGAIN;
1424 			goto out;
1425 		}
1426 
1427 		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1428 	}
1429 	finish_wait(sk_sleep(listener), &wait);
1430 
1431 	if (listener->sk_err)
1432 		err = -listener->sk_err;
1433 
1434 	if (connected) {
1435 		sk_acceptq_removed(listener);
1436 
1437 		lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1438 		vconnected = vsock_sk(connected);
1439 
1440 		/* If the listener socket has received an error, then we should
1441 		 * reject this socket and return.  Note that we simply mark the
1442 		 * socket rejected, drop our reference, and let the cleanup
1443 		 * function handle the cleanup; the fact that we found it in
1444 		 * the listener's accept queue guarantees that the cleanup
1445 		 * function hasn't run yet.
1446 		 */
1447 		if (err) {
1448 			vconnected->rejected = true;
1449 		} else {
1450 			newsock->state = SS_CONNECTED;
1451 			sock_graft(connected, newsock);
1452 		}
1453 
1454 		release_sock(connected);
1455 		sock_put(connected);
1456 	}
1457 
1458 out:
1459 	release_sock(listener);
1460 	return err;
1461 }
1462 
1463 static int vsock_listen(struct socket *sock, int backlog)
1464 {
1465 	int err;
1466 	struct sock *sk;
1467 	struct vsock_sock *vsk;
1468 
1469 	sk = sock->sk;
1470 
1471 	lock_sock(sk);
1472 
1473 	if (sock->type != SOCK_STREAM) {
1474 		err = -EOPNOTSUPP;
1475 		goto out;
1476 	}
1477 
1478 	if (sock->state != SS_UNCONNECTED) {
1479 		err = -EINVAL;
1480 		goto out;
1481 	}
1482 
1483 	vsk = vsock_sk(sk);
1484 
1485 	if (!vsock_addr_bound(&vsk->local_addr)) {
1486 		err = -EINVAL;
1487 		goto out;
1488 	}
1489 
1490 	sk->sk_max_ack_backlog = backlog;
1491 	sk->sk_state = TCP_LISTEN;
1492 
1493 	err = 0;
1494 
1495 out:
1496 	release_sock(sk);
1497 	return err;
1498 }
1499 
1500 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1501 				     const struct vsock_transport *transport,
1502 				     u64 val)
1503 {
1504 	if (val > vsk->buffer_max_size)
1505 		val = vsk->buffer_max_size;
1506 
1507 	if (val < vsk->buffer_min_size)
1508 		val = vsk->buffer_min_size;
1509 
1510 	if (val != vsk->buffer_size &&
1511 	    transport && transport->notify_buffer_size)
1512 		transport->notify_buffer_size(vsk, &val);
1513 
1514 	vsk->buffer_size = val;
1515 }
1516 
1517 static int vsock_stream_setsockopt(struct socket *sock,
1518 				   int level,
1519 				   int optname,
1520 				   sockptr_t optval,
1521 				   unsigned int optlen)
1522 {
1523 	int err;
1524 	struct sock *sk;
1525 	struct vsock_sock *vsk;
1526 	const struct vsock_transport *transport;
1527 	u64 val;
1528 
1529 	if (level != AF_VSOCK)
1530 		return -ENOPROTOOPT;
1531 
1532 #define COPY_IN(_v)                                       \
1533 	do {						  \
1534 		if (optlen < sizeof(_v)) {		  \
1535 			err = -EINVAL;			  \
1536 			goto exit;			  \
1537 		}					  \
1538 		if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {	\
1539 			err = -EFAULT;					\
1540 			goto exit;					\
1541 		}							\
1542 	} while (0)
1543 
1544 	err = 0;
1545 	sk = sock->sk;
1546 	vsk = vsock_sk(sk);
1547 	transport = vsk->transport;
1548 
1549 	lock_sock(sk);
1550 
1551 	switch (optname) {
1552 	case SO_VM_SOCKETS_BUFFER_SIZE:
1553 		COPY_IN(val);
1554 		vsock_update_buffer_size(vsk, transport, val);
1555 		break;
1556 
1557 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1558 		COPY_IN(val);
1559 		vsk->buffer_max_size = val;
1560 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1561 		break;
1562 
1563 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1564 		COPY_IN(val);
1565 		vsk->buffer_min_size = val;
1566 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1567 		break;
1568 
1569 	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1570 		struct __kernel_old_timeval tv;
1571 		COPY_IN(tv);
1572 		if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1573 		    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1574 			vsk->connect_timeout = tv.tv_sec * HZ +
1575 			    DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
1576 			if (vsk->connect_timeout == 0)
1577 				vsk->connect_timeout =
1578 				    VSOCK_DEFAULT_CONNECT_TIMEOUT;
1579 
1580 		} else {
1581 			err = -ERANGE;
1582 		}
1583 		break;
1584 	}
1585 
1586 	default:
1587 		err = -ENOPROTOOPT;
1588 		break;
1589 	}
1590 
1591 #undef COPY_IN
1592 
1593 exit:
1594 	release_sock(sk);
1595 	return err;
1596 }
1597 
1598 static int vsock_stream_getsockopt(struct socket *sock,
1599 				   int level, int optname,
1600 				   char __user *optval,
1601 				   int __user *optlen)
1602 {
1603 	int err;
1604 	int len;
1605 	struct sock *sk;
1606 	struct vsock_sock *vsk;
1607 	u64 val;
1608 
1609 	if (level != AF_VSOCK)
1610 		return -ENOPROTOOPT;
1611 
1612 	err = get_user(len, optlen);
1613 	if (err != 0)
1614 		return err;
1615 
1616 #define COPY_OUT(_v)                            \
1617 	do {					\
1618 		if (len < sizeof(_v))		\
1619 			return -EINVAL;		\
1620 						\
1621 		len = sizeof(_v);		\
1622 		if (copy_to_user(optval, &_v, len) != 0)	\
1623 			return -EFAULT;				\
1624 								\
1625 	} while (0)
1626 
1627 	err = 0;
1628 	sk = sock->sk;
1629 	vsk = vsock_sk(sk);
1630 
1631 	switch (optname) {
1632 	case SO_VM_SOCKETS_BUFFER_SIZE:
1633 		val = vsk->buffer_size;
1634 		COPY_OUT(val);
1635 		break;
1636 
1637 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1638 		val = vsk->buffer_max_size;
1639 		COPY_OUT(val);
1640 		break;
1641 
1642 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1643 		val = vsk->buffer_min_size;
1644 		COPY_OUT(val);
1645 		break;
1646 
1647 	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
1648 		struct __kernel_old_timeval tv;
1649 		tv.tv_sec = vsk->connect_timeout / HZ;
1650 		tv.tv_usec =
1651 		    (vsk->connect_timeout -
1652 		     tv.tv_sec * HZ) * (1000000 / HZ);
1653 		COPY_OUT(tv);
1654 		break;
1655 	}
1656 	default:
1657 		return -ENOPROTOOPT;
1658 	}
1659 
1660 	err = put_user(len, optlen);
1661 	if (err != 0)
1662 		return -EFAULT;
1663 
1664 #undef COPY_OUT
1665 
1666 	return 0;
1667 }
1668 
1669 static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
1670 				size_t len)
1671 {
1672 	struct sock *sk;
1673 	struct vsock_sock *vsk;
1674 	const struct vsock_transport *transport;
1675 	ssize_t total_written;
1676 	long timeout;
1677 	int err;
1678 	struct vsock_transport_send_notify_data send_data;
1679 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1680 
1681 	sk = sock->sk;
1682 	vsk = vsock_sk(sk);
1683 	transport = vsk->transport;
1684 	total_written = 0;
1685 	err = 0;
1686 
1687 	if (msg->msg_flags & MSG_OOB)
1688 		return -EOPNOTSUPP;
1689 
1690 	lock_sock(sk);
1691 
1692 	/* Callers should not provide a destination with stream sockets. */
1693 	if (msg->msg_namelen) {
1694 		err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1695 		goto out;
1696 	}
1697 
1698 	/* Send data only if both sides are not shutdown in the direction. */
1699 	if (sk->sk_shutdown & SEND_SHUTDOWN ||
1700 	    vsk->peer_shutdown & RCV_SHUTDOWN) {
1701 		err = -EPIPE;
1702 		goto out;
1703 	}
1704 
1705 	if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1706 	    !vsock_addr_bound(&vsk->local_addr)) {
1707 		err = -ENOTCONN;
1708 		goto out;
1709 	}
1710 
1711 	if (!vsock_addr_bound(&vsk->remote_addr)) {
1712 		err = -EDESTADDRREQ;
1713 		goto out;
1714 	}
1715 
1716 	/* Wait for room in the produce queue to enqueue our user's data. */
1717 	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1718 
1719 	err = transport->notify_send_init(vsk, &send_data);
1720 	if (err < 0)
1721 		goto out;
1722 
1723 	while (total_written < len) {
1724 		ssize_t written;
1725 
1726 		add_wait_queue(sk_sleep(sk), &wait);
1727 		while (vsock_stream_has_space(vsk) == 0 &&
1728 		       sk->sk_err == 0 &&
1729 		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1730 		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1731 
1732 			/* Don't wait for non-blocking sockets. */
1733 			if (timeout == 0) {
1734 				err = -EAGAIN;
1735 				remove_wait_queue(sk_sleep(sk), &wait);
1736 				goto out_err;
1737 			}
1738 
1739 			err = transport->notify_send_pre_block(vsk, &send_data);
1740 			if (err < 0) {
1741 				remove_wait_queue(sk_sleep(sk), &wait);
1742 				goto out_err;
1743 			}
1744 
1745 			release_sock(sk);
1746 			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1747 			lock_sock(sk);
1748 			if (signal_pending(current)) {
1749 				err = sock_intr_errno(timeout);
1750 				remove_wait_queue(sk_sleep(sk), &wait);
1751 				goto out_err;
1752 			} else if (timeout == 0) {
1753 				err = -EAGAIN;
1754 				remove_wait_queue(sk_sleep(sk), &wait);
1755 				goto out_err;
1756 			}
1757 		}
1758 		remove_wait_queue(sk_sleep(sk), &wait);
1759 
1760 		/* These checks occur both as part of and after the loop
1761 		 * conditional since we need to check before and after
1762 		 * sleeping.
1763 		 */
1764 		if (sk->sk_err) {
1765 			err = -sk->sk_err;
1766 			goto out_err;
1767 		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
1768 			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
1769 			err = -EPIPE;
1770 			goto out_err;
1771 		}
1772 
1773 		err = transport->notify_send_pre_enqueue(vsk, &send_data);
1774 		if (err < 0)
1775 			goto out_err;
1776 
1777 		/* Note that enqueue will only write as many bytes as are free
1778 		 * in the produce queue, so we don't need to ensure len is
1779 		 * smaller than the queue size.  It is the caller's
1780 		 * responsibility to check how many bytes we were able to send.
1781 		 */
1782 
1783 		written = transport->stream_enqueue(
1784 				vsk, msg,
1785 				len - total_written);
1786 		if (written < 0) {
1787 			err = -ENOMEM;
1788 			goto out_err;
1789 		}
1790 
1791 		total_written += written;
1792 
1793 		err = transport->notify_send_post_enqueue(
1794 				vsk, written, &send_data);
1795 		if (err < 0)
1796 			goto out_err;
1797 
1798 	}
1799 
1800 out_err:
1801 	if (total_written > 0)
1802 		err = total_written;
1803 out:
1804 	release_sock(sk);
1805 	return err;
1806 }
1807 
1808 
1809 static int
1810 vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1811 		     int flags)
1812 {
1813 	struct sock *sk;
1814 	struct vsock_sock *vsk;
1815 	const struct vsock_transport *transport;
1816 	int err;
1817 	size_t target;
1818 	ssize_t copied;
1819 	long timeout;
1820 	struct vsock_transport_recv_notify_data recv_data;
1821 
1822 	DEFINE_WAIT(wait);
1823 
1824 	sk = sock->sk;
1825 	vsk = vsock_sk(sk);
1826 	transport = vsk->transport;
1827 	err = 0;
1828 
1829 	lock_sock(sk);
1830 
1831 	if (!transport || sk->sk_state != TCP_ESTABLISHED) {
1832 		/* Recvmsg is supposed to return 0 if a peer performs an
1833 		 * orderly shutdown. Differentiate between that case and when a
1834 		 * peer has not connected or a local shutdown occured with the
1835 		 * SOCK_DONE flag.
1836 		 */
1837 		if (sock_flag(sk, SOCK_DONE))
1838 			err = 0;
1839 		else
1840 			err = -ENOTCONN;
1841 
1842 		goto out;
1843 	}
1844 
1845 	if (flags & MSG_OOB) {
1846 		err = -EOPNOTSUPP;
1847 		goto out;
1848 	}
1849 
1850 	/* We don't check peer_shutdown flag here since peer may actually shut
1851 	 * down, but there can be data in the queue that a local socket can
1852 	 * receive.
1853 	 */
1854 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
1855 		err = 0;
1856 		goto out;
1857 	}
1858 
1859 	/* It is valid on Linux to pass in a zero-length receive buffer.  This
1860 	 * is not an error.  We may as well bail out now.
1861 	 */
1862 	if (!len) {
1863 		err = 0;
1864 		goto out;
1865 	}
1866 
1867 	/* We must not copy less than target bytes into the user's buffer
1868 	 * before returning successfully, so we wait for the consume queue to
1869 	 * have that much data to consume before dequeueing.  Note that this
1870 	 * makes it impossible to handle cases where target is greater than the
1871 	 * queue size.
1872 	 */
1873 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1874 	if (target >= transport->stream_rcvhiwat(vsk)) {
1875 		err = -ENOMEM;
1876 		goto out;
1877 	}
1878 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1879 	copied = 0;
1880 
1881 	err = transport->notify_recv_init(vsk, target, &recv_data);
1882 	if (err < 0)
1883 		goto out;
1884 
1885 
1886 	while (1) {
1887 		s64 ready;
1888 
1889 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1890 		ready = vsock_stream_has_data(vsk);
1891 
1892 		if (ready == 0) {
1893 			if (sk->sk_err != 0 ||
1894 			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
1895 			    (vsk->peer_shutdown & SEND_SHUTDOWN)) {
1896 				finish_wait(sk_sleep(sk), &wait);
1897 				break;
1898 			}
1899 			/* Don't wait for non-blocking sockets. */
1900 			if (timeout == 0) {
1901 				err = -EAGAIN;
1902 				finish_wait(sk_sleep(sk), &wait);
1903 				break;
1904 			}
1905 
1906 			err = transport->notify_recv_pre_block(
1907 					vsk, target, &recv_data);
1908 			if (err < 0) {
1909 				finish_wait(sk_sleep(sk), &wait);
1910 				break;
1911 			}
1912 			release_sock(sk);
1913 			timeout = schedule_timeout(timeout);
1914 			lock_sock(sk);
1915 
1916 			if (signal_pending(current)) {
1917 				err = sock_intr_errno(timeout);
1918 				finish_wait(sk_sleep(sk), &wait);
1919 				break;
1920 			} else if (timeout == 0) {
1921 				err = -EAGAIN;
1922 				finish_wait(sk_sleep(sk), &wait);
1923 				break;
1924 			}
1925 		} else {
1926 			ssize_t read;
1927 
1928 			finish_wait(sk_sleep(sk), &wait);
1929 
1930 			if (ready < 0) {
1931 				/* Invalid queue pair content. XXX This should
1932 				* be changed to a connection reset in a later
1933 				* change.
1934 				*/
1935 
1936 				err = -ENOMEM;
1937 				goto out;
1938 			}
1939 
1940 			err = transport->notify_recv_pre_dequeue(
1941 					vsk, target, &recv_data);
1942 			if (err < 0)
1943 				break;
1944 
1945 			read = transport->stream_dequeue(
1946 					vsk, msg,
1947 					len - copied, flags);
1948 			if (read < 0) {
1949 				err = -ENOMEM;
1950 				break;
1951 			}
1952 
1953 			copied += read;
1954 
1955 			err = transport->notify_recv_post_dequeue(
1956 					vsk, target, read,
1957 					!(flags & MSG_PEEK), &recv_data);
1958 			if (err < 0)
1959 				goto out;
1960 
1961 			if (read >= target || flags & MSG_PEEK)
1962 				break;
1963 
1964 			target -= read;
1965 		}
1966 	}
1967 
1968 	if (sk->sk_err)
1969 		err = -sk->sk_err;
1970 	else if (sk->sk_shutdown & RCV_SHUTDOWN)
1971 		err = 0;
1972 
1973 	if (copied > 0)
1974 		err = copied;
1975 
1976 out:
1977 	release_sock(sk);
1978 	return err;
1979 }
1980 
1981 static const struct proto_ops vsock_stream_ops = {
1982 	.family = PF_VSOCK,
1983 	.owner = THIS_MODULE,
1984 	.release = vsock_release,
1985 	.bind = vsock_bind,
1986 	.connect = vsock_stream_connect,
1987 	.socketpair = sock_no_socketpair,
1988 	.accept = vsock_accept,
1989 	.getname = vsock_getname,
1990 	.poll = vsock_poll,
1991 	.ioctl = sock_no_ioctl,
1992 	.listen = vsock_listen,
1993 	.shutdown = vsock_shutdown,
1994 	.setsockopt = vsock_stream_setsockopt,
1995 	.getsockopt = vsock_stream_getsockopt,
1996 	.sendmsg = vsock_stream_sendmsg,
1997 	.recvmsg = vsock_stream_recvmsg,
1998 	.mmap = sock_no_mmap,
1999 	.sendpage = sock_no_sendpage,
2000 };
2001 
2002 static int vsock_create(struct net *net, struct socket *sock,
2003 			int protocol, int kern)
2004 {
2005 	struct vsock_sock *vsk;
2006 	struct sock *sk;
2007 	int ret;
2008 
2009 	if (!sock)
2010 		return -EINVAL;
2011 
2012 	if (protocol && protocol != PF_VSOCK)
2013 		return -EPROTONOSUPPORT;
2014 
2015 	switch (sock->type) {
2016 	case SOCK_DGRAM:
2017 		sock->ops = &vsock_dgram_ops;
2018 		break;
2019 	case SOCK_STREAM:
2020 		sock->ops = &vsock_stream_ops;
2021 		break;
2022 	default:
2023 		return -ESOCKTNOSUPPORT;
2024 	}
2025 
2026 	sock->state = SS_UNCONNECTED;
2027 
2028 	sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2029 	if (!sk)
2030 		return -ENOMEM;
2031 
2032 	vsk = vsock_sk(sk);
2033 
2034 	if (sock->type == SOCK_DGRAM) {
2035 		ret = vsock_assign_transport(vsk, NULL);
2036 		if (ret < 0) {
2037 			sock_put(sk);
2038 			return ret;
2039 		}
2040 	}
2041 
2042 	vsock_insert_unbound(vsk);
2043 
2044 	return 0;
2045 }
2046 
2047 static const struct net_proto_family vsock_family_ops = {
2048 	.family = AF_VSOCK,
2049 	.create = vsock_create,
2050 	.owner = THIS_MODULE,
2051 };
2052 
2053 static long vsock_dev_do_ioctl(struct file *filp,
2054 			       unsigned int cmd, void __user *ptr)
2055 {
2056 	u32 __user *p = ptr;
2057 	u32 cid = VMADDR_CID_ANY;
2058 	int retval = 0;
2059 
2060 	switch (cmd) {
2061 	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2062 		/* To be compatible with the VMCI behavior, we prioritize the
2063 		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2064 		 */
2065 		if (transport_g2h)
2066 			cid = transport_g2h->get_local_cid();
2067 		else if (transport_h2g)
2068 			cid = transport_h2g->get_local_cid();
2069 
2070 		if (put_user(cid, p) != 0)
2071 			retval = -EFAULT;
2072 		break;
2073 
2074 	default:
2075 		pr_err("Unknown ioctl %d\n", cmd);
2076 		retval = -EINVAL;
2077 	}
2078 
2079 	return retval;
2080 }
2081 
2082 static long vsock_dev_ioctl(struct file *filp,
2083 			    unsigned int cmd, unsigned long arg)
2084 {
2085 	return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2086 }
2087 
2088 #ifdef CONFIG_COMPAT
2089 static long vsock_dev_compat_ioctl(struct file *filp,
2090 				   unsigned int cmd, unsigned long arg)
2091 {
2092 	return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2093 }
2094 #endif
2095 
2096 static const struct file_operations vsock_device_ops = {
2097 	.owner		= THIS_MODULE,
2098 	.unlocked_ioctl	= vsock_dev_ioctl,
2099 #ifdef CONFIG_COMPAT
2100 	.compat_ioctl	= vsock_dev_compat_ioctl,
2101 #endif
2102 	.open		= nonseekable_open,
2103 };
2104 
2105 static struct miscdevice vsock_device = {
2106 	.name		= "vsock",
2107 	.fops		= &vsock_device_ops,
2108 };
2109 
2110 static int __init vsock_init(void)
2111 {
2112 	int err = 0;
2113 
2114 	vsock_init_tables();
2115 
2116 	vsock_proto.owner = THIS_MODULE;
2117 	vsock_device.minor = MISC_DYNAMIC_MINOR;
2118 	err = misc_register(&vsock_device);
2119 	if (err) {
2120 		pr_err("Failed to register misc device\n");
2121 		goto err_reset_transport;
2122 	}
2123 
2124 	err = proto_register(&vsock_proto, 1);	/* we want our slab */
2125 	if (err) {
2126 		pr_err("Cannot register vsock protocol\n");
2127 		goto err_deregister_misc;
2128 	}
2129 
2130 	err = sock_register(&vsock_family_ops);
2131 	if (err) {
2132 		pr_err("could not register af_vsock (%d) address family: %d\n",
2133 		       AF_VSOCK, err);
2134 		goto err_unregister_proto;
2135 	}
2136 
2137 	return 0;
2138 
2139 err_unregister_proto:
2140 	proto_unregister(&vsock_proto);
2141 err_deregister_misc:
2142 	misc_deregister(&vsock_device);
2143 err_reset_transport:
2144 	return err;
2145 }
2146 
2147 static void __exit vsock_exit(void)
2148 {
2149 	misc_deregister(&vsock_device);
2150 	sock_unregister(AF_VSOCK);
2151 	proto_unregister(&vsock_proto);
2152 }
2153 
2154 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2155 {
2156 	return vsk->transport;
2157 }
2158 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2159 
2160 int vsock_core_register(const struct vsock_transport *t, int features)
2161 {
2162 	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2163 	int err = mutex_lock_interruptible(&vsock_register_mutex);
2164 
2165 	if (err)
2166 		return err;
2167 
2168 	t_h2g = transport_h2g;
2169 	t_g2h = transport_g2h;
2170 	t_dgram = transport_dgram;
2171 	t_local = transport_local;
2172 
2173 	if (features & VSOCK_TRANSPORT_F_H2G) {
2174 		if (t_h2g) {
2175 			err = -EBUSY;
2176 			goto err_busy;
2177 		}
2178 		t_h2g = t;
2179 	}
2180 
2181 	if (features & VSOCK_TRANSPORT_F_G2H) {
2182 		if (t_g2h) {
2183 			err = -EBUSY;
2184 			goto err_busy;
2185 		}
2186 		t_g2h = t;
2187 	}
2188 
2189 	if (features & VSOCK_TRANSPORT_F_DGRAM) {
2190 		if (t_dgram) {
2191 			err = -EBUSY;
2192 			goto err_busy;
2193 		}
2194 		t_dgram = t;
2195 	}
2196 
2197 	if (features & VSOCK_TRANSPORT_F_LOCAL) {
2198 		if (t_local) {
2199 			err = -EBUSY;
2200 			goto err_busy;
2201 		}
2202 		t_local = t;
2203 	}
2204 
2205 	transport_h2g = t_h2g;
2206 	transport_g2h = t_g2h;
2207 	transport_dgram = t_dgram;
2208 	transport_local = t_local;
2209 
2210 err_busy:
2211 	mutex_unlock(&vsock_register_mutex);
2212 	return err;
2213 }
2214 EXPORT_SYMBOL_GPL(vsock_core_register);
2215 
2216 void vsock_core_unregister(const struct vsock_transport *t)
2217 {
2218 	mutex_lock(&vsock_register_mutex);
2219 
2220 	if (transport_h2g == t)
2221 		transport_h2g = NULL;
2222 
2223 	if (transport_g2h == t)
2224 		transport_g2h = NULL;
2225 
2226 	if (transport_dgram == t)
2227 		transport_dgram = NULL;
2228 
2229 	if (transport_local == t)
2230 		transport_local = NULL;
2231 
2232 	mutex_unlock(&vsock_register_mutex);
2233 }
2234 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2235 
2236 module_init(vsock_init);
2237 module_exit(vsock_exit);
2238 
2239 MODULE_AUTHOR("VMware, Inc.");
2240 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2241 MODULE_VERSION("1.0.2.0-k");
2242 MODULE_LICENSE("GPL v2");
2243