xref: /linux/net/vmw_vsock/af_vsock.c (revision 7b26bc6582b13a52a42a4a9765e8f30d58a81198)
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/errqueue.h>
93 #include <linux/init.h>
94 #include <linux/io.h>
95 #include <linux/kernel.h>
96 #include <linux/sched/signal.h>
97 #include <linux/kmod.h>
98 #include <linux/list.h>
99 #include <linux/miscdevice.h>
100 #include <linux/module.h>
101 #include <linux/mutex.h>
102 #include <linux/net.h>
103 #include <linux/poll.h>
104 #include <linux/random.h>
105 #include <linux/skbuff.h>
106 #include <linux/smp.h>
107 #include <linux/socket.h>
108 #include <linux/stddef.h>
109 #include <linux/unistd.h>
110 #include <linux/wait.h>
111 #include <linux/workqueue.h>
112 #include <net/sock.h>
113 #include <net/af_vsock.h>
114 #include <uapi/linux/vm_sockets.h>
115 #include <uapi/asm-generic/ioctls.h>
116 
117 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
118 static void vsock_sk_destruct(struct sock *sk);
119 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
120 static void vsock_close(struct sock *sk, long timeout);
121 
122 /* Protocol family. */
123 struct proto vsock_proto = {
124 	.name = "AF_VSOCK",
125 	.owner = THIS_MODULE,
126 	.obj_size = sizeof(struct vsock_sock),
127 	.close = vsock_close,
128 #ifdef CONFIG_BPF_SYSCALL
129 	.psock_update_sk_prot = vsock_bpf_update_proto,
130 #endif
131 };
132 
133 /* The default peer timeout indicates how long we will wait for a peer response
134  * to a control message.
135  */
136 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
137 
138 #define VSOCK_DEFAULT_BUFFER_SIZE     (1024 * 256)
139 #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
140 #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
141 
142 /* Transport used for host->guest communication */
143 static const struct vsock_transport *transport_h2g;
144 /* Transport used for guest->host communication */
145 static const struct vsock_transport *transport_g2h;
146 /* Transport used for DGRAM communication */
147 static const struct vsock_transport *transport_dgram;
148 /* Transport used for local communication */
149 static const struct vsock_transport *transport_local;
150 static DEFINE_MUTEX(vsock_register_mutex);
151 
152 /**** UTILS ****/
153 
154 /* Each bound VSocket is stored in the bind hash table and each connected
155  * VSocket is stored in the connected hash table.
156  *
157  * Unbound sockets are all put on the same list attached to the end of the hash
158  * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
159  * the bucket that their local address hashes to (vsock_bound_sockets(addr)
160  * represents the list that addr hashes to).
161  *
162  * Specifically, we initialize the vsock_bind_table array to a size of
163  * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
164  * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
165  * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
166  * mods with VSOCK_HASH_SIZE to ensure this.
167  */
168 #define MAX_PORT_RETRIES        24
169 
170 #define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
171 #define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
172 #define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
173 
174 /* XXX This can probably be implemented in a better way. */
175 #define VSOCK_CONN_HASH(src, dst)				\
176 	(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
177 #define vsock_connected_sockets(src, dst)		\
178 	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
179 #define vsock_connected_sockets_vsk(vsk)				\
180 	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
181 
182 struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
183 EXPORT_SYMBOL_GPL(vsock_bind_table);
184 struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
185 EXPORT_SYMBOL_GPL(vsock_connected_table);
186 DEFINE_SPINLOCK(vsock_table_lock);
187 EXPORT_SYMBOL_GPL(vsock_table_lock);
188 
189 /* Autobind this socket to the local address if necessary. */
190 static int vsock_auto_bind(struct vsock_sock *vsk)
191 {
192 	struct sock *sk = sk_vsock(vsk);
193 	struct sockaddr_vm local_addr;
194 
195 	if (vsock_addr_bound(&vsk->local_addr))
196 		return 0;
197 	vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
198 	return __vsock_bind(sk, &local_addr);
199 }
200 
201 static void vsock_init_tables(void)
202 {
203 	int i;
204 
205 	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
206 		INIT_LIST_HEAD(&vsock_bind_table[i]);
207 
208 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
209 		INIT_LIST_HEAD(&vsock_connected_table[i]);
210 }
211 
212 static void __vsock_insert_bound(struct list_head *list,
213 				 struct vsock_sock *vsk)
214 {
215 	sock_hold(&vsk->sk);
216 	list_add(&vsk->bound_table, list);
217 }
218 
219 static void __vsock_insert_connected(struct list_head *list,
220 				     struct vsock_sock *vsk)
221 {
222 	sock_hold(&vsk->sk);
223 	list_add(&vsk->connected_table, list);
224 }
225 
226 static void __vsock_remove_bound(struct vsock_sock *vsk)
227 {
228 	list_del_init(&vsk->bound_table);
229 	sock_put(&vsk->sk);
230 }
231 
232 static void __vsock_remove_connected(struct vsock_sock *vsk)
233 {
234 	list_del_init(&vsk->connected_table);
235 	sock_put(&vsk->sk);
236 }
237 
238 static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
239 {
240 	struct vsock_sock *vsk;
241 
242 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
243 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
244 			return sk_vsock(vsk);
245 
246 		if (addr->svm_port == vsk->local_addr.svm_port &&
247 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
248 		     addr->svm_cid == VMADDR_CID_ANY))
249 			return sk_vsock(vsk);
250 	}
251 
252 	return NULL;
253 }
254 
255 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
256 						  struct sockaddr_vm *dst)
257 {
258 	struct vsock_sock *vsk;
259 
260 	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
261 			    connected_table) {
262 		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
263 		    dst->svm_port == vsk->local_addr.svm_port) {
264 			return sk_vsock(vsk);
265 		}
266 	}
267 
268 	return NULL;
269 }
270 
271 static void vsock_insert_unbound(struct vsock_sock *vsk)
272 {
273 	spin_lock_bh(&vsock_table_lock);
274 	__vsock_insert_bound(vsock_unbound_sockets, vsk);
275 	spin_unlock_bh(&vsock_table_lock);
276 }
277 
278 void vsock_insert_connected(struct vsock_sock *vsk)
279 {
280 	struct list_head *list = vsock_connected_sockets(
281 		&vsk->remote_addr, &vsk->local_addr);
282 
283 	spin_lock_bh(&vsock_table_lock);
284 	__vsock_insert_connected(list, vsk);
285 	spin_unlock_bh(&vsock_table_lock);
286 }
287 EXPORT_SYMBOL_GPL(vsock_insert_connected);
288 
289 void vsock_remove_bound(struct vsock_sock *vsk)
290 {
291 	spin_lock_bh(&vsock_table_lock);
292 	if (__vsock_in_bound_table(vsk))
293 		__vsock_remove_bound(vsk);
294 	spin_unlock_bh(&vsock_table_lock);
295 }
296 EXPORT_SYMBOL_GPL(vsock_remove_bound);
297 
298 void vsock_remove_connected(struct vsock_sock *vsk)
299 {
300 	spin_lock_bh(&vsock_table_lock);
301 	if (__vsock_in_connected_table(vsk))
302 		__vsock_remove_connected(vsk);
303 	spin_unlock_bh(&vsock_table_lock);
304 }
305 EXPORT_SYMBOL_GPL(vsock_remove_connected);
306 
307 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
308 {
309 	struct sock *sk;
310 
311 	spin_lock_bh(&vsock_table_lock);
312 	sk = __vsock_find_bound_socket(addr);
313 	if (sk)
314 		sock_hold(sk);
315 
316 	spin_unlock_bh(&vsock_table_lock);
317 
318 	return sk;
319 }
320 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
321 
322 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
323 					 struct sockaddr_vm *dst)
324 {
325 	struct sock *sk;
326 
327 	spin_lock_bh(&vsock_table_lock);
328 	sk = __vsock_find_connected_socket(src, dst);
329 	if (sk)
330 		sock_hold(sk);
331 
332 	spin_unlock_bh(&vsock_table_lock);
333 
334 	return sk;
335 }
336 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
337 
338 void vsock_remove_sock(struct vsock_sock *vsk)
339 {
340 	vsock_remove_bound(vsk);
341 	vsock_remove_connected(vsk);
342 }
343 EXPORT_SYMBOL_GPL(vsock_remove_sock);
344 
345 void vsock_for_each_connected_socket(struct vsock_transport *transport,
346 				     void (*fn)(struct sock *sk))
347 {
348 	int i;
349 
350 	spin_lock_bh(&vsock_table_lock);
351 
352 	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
353 		struct vsock_sock *vsk;
354 		list_for_each_entry(vsk, &vsock_connected_table[i],
355 				    connected_table) {
356 			if (vsk->transport != transport)
357 				continue;
358 
359 			fn(sk_vsock(vsk));
360 		}
361 	}
362 
363 	spin_unlock_bh(&vsock_table_lock);
364 }
365 EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
366 
367 void vsock_add_pending(struct sock *listener, struct sock *pending)
368 {
369 	struct vsock_sock *vlistener;
370 	struct vsock_sock *vpending;
371 
372 	vlistener = vsock_sk(listener);
373 	vpending = vsock_sk(pending);
374 
375 	sock_hold(pending);
376 	sock_hold(listener);
377 	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
378 }
379 EXPORT_SYMBOL_GPL(vsock_add_pending);
380 
381 void vsock_remove_pending(struct sock *listener, struct sock *pending)
382 {
383 	struct vsock_sock *vpending = vsock_sk(pending);
384 
385 	list_del_init(&vpending->pending_links);
386 	sock_put(listener);
387 	sock_put(pending);
388 }
389 EXPORT_SYMBOL_GPL(vsock_remove_pending);
390 
391 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
392 {
393 	struct vsock_sock *vlistener;
394 	struct vsock_sock *vconnected;
395 
396 	vlistener = vsock_sk(listener);
397 	vconnected = vsock_sk(connected);
398 
399 	sock_hold(connected);
400 	sock_hold(listener);
401 	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
402 }
403 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
404 
405 static bool vsock_use_local_transport(unsigned int remote_cid)
406 {
407 	if (!transport_local)
408 		return false;
409 
410 	if (remote_cid == VMADDR_CID_LOCAL)
411 		return true;
412 
413 	if (transport_g2h) {
414 		return remote_cid == transport_g2h->get_local_cid();
415 	} else {
416 		return remote_cid == VMADDR_CID_HOST;
417 	}
418 }
419 
420 static void vsock_deassign_transport(struct vsock_sock *vsk)
421 {
422 	if (!vsk->transport)
423 		return;
424 
425 	vsk->transport->destruct(vsk);
426 	module_put(vsk->transport->module);
427 	vsk->transport = NULL;
428 }
429 
430 /* Assign a transport to a socket and call the .init transport callback.
431  *
432  * Note: for connection oriented socket this must be called when vsk->remote_addr
433  * is set (e.g. during the connect() or when a connection request on a listener
434  * socket is received).
435  * The vsk->remote_addr is used to decide which transport to use:
436  *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
437  *    g2h is not loaded, will use local transport;
438  *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
439  *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
440  *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
441  */
442 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
443 {
444 	const struct vsock_transport *new_transport;
445 	struct sock *sk = sk_vsock(vsk);
446 	unsigned int remote_cid = vsk->remote_addr.svm_cid;
447 	__u8 remote_flags;
448 	int ret;
449 
450 	/* If the packet is coming with the source and destination CIDs higher
451 	 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
452 	 * forwarded to the host should be established. Then the host will
453 	 * need to forward the packets to the guest.
454 	 *
455 	 * The flag is set on the (listen) receive path (psk is not NULL). On
456 	 * the connect path the flag can be set by the user space application.
457 	 */
458 	if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
459 	    vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
460 		vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
461 
462 	remote_flags = vsk->remote_addr.svm_flags;
463 
464 	switch (sk->sk_type) {
465 	case SOCK_DGRAM:
466 		new_transport = transport_dgram;
467 		break;
468 	case SOCK_STREAM:
469 	case SOCK_SEQPACKET:
470 		if (vsock_use_local_transport(remote_cid))
471 			new_transport = transport_local;
472 		else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
473 			 (remote_flags & VMADDR_FLAG_TO_HOST))
474 			new_transport = transport_g2h;
475 		else
476 			new_transport = transport_h2g;
477 		break;
478 	default:
479 		return -ESOCKTNOSUPPORT;
480 	}
481 
482 	if (vsk->transport) {
483 		if (vsk->transport == new_transport)
484 			return 0;
485 
486 		/* transport->release() must be called with sock lock acquired.
487 		 * This path can only be taken during vsock_connect(), where we
488 		 * have already held the sock lock. In the other cases, this
489 		 * function is called on a new socket which is not assigned to
490 		 * any transport.
491 		 */
492 		vsk->transport->release(vsk);
493 		vsock_deassign_transport(vsk);
494 	}
495 
496 	/* We increase the module refcnt to prevent the transport unloading
497 	 * while there are open sockets assigned to it.
498 	 */
499 	if (!new_transport || !try_module_get(new_transport->module))
500 		return -ENODEV;
501 
502 	if (sk->sk_type == SOCK_SEQPACKET) {
503 		if (!new_transport->seqpacket_allow ||
504 		    !new_transport->seqpacket_allow(remote_cid)) {
505 			module_put(new_transport->module);
506 			return -ESOCKTNOSUPPORT;
507 		}
508 	}
509 
510 	ret = new_transport->init(vsk, psk);
511 	if (ret) {
512 		module_put(new_transport->module);
513 		return ret;
514 	}
515 
516 	vsk->transport = new_transport;
517 
518 	return 0;
519 }
520 EXPORT_SYMBOL_GPL(vsock_assign_transport);
521 
522 bool vsock_find_cid(unsigned int cid)
523 {
524 	if (transport_g2h && cid == transport_g2h->get_local_cid())
525 		return true;
526 
527 	if (transport_h2g && cid == VMADDR_CID_HOST)
528 		return true;
529 
530 	if (transport_local && cid == VMADDR_CID_LOCAL)
531 		return true;
532 
533 	return false;
534 }
535 EXPORT_SYMBOL_GPL(vsock_find_cid);
536 
537 static struct sock *vsock_dequeue_accept(struct sock *listener)
538 {
539 	struct vsock_sock *vlistener;
540 	struct vsock_sock *vconnected;
541 
542 	vlistener = vsock_sk(listener);
543 
544 	if (list_empty(&vlistener->accept_queue))
545 		return NULL;
546 
547 	vconnected = list_entry(vlistener->accept_queue.next,
548 				struct vsock_sock, accept_queue);
549 
550 	list_del_init(&vconnected->accept_queue);
551 	sock_put(listener);
552 	/* The caller will need a reference on the connected socket so we let
553 	 * it call sock_put().
554 	 */
555 
556 	return sk_vsock(vconnected);
557 }
558 
559 static bool vsock_is_accept_queue_empty(struct sock *sk)
560 {
561 	struct vsock_sock *vsk = vsock_sk(sk);
562 	return list_empty(&vsk->accept_queue);
563 }
564 
565 static bool vsock_is_pending(struct sock *sk)
566 {
567 	struct vsock_sock *vsk = vsock_sk(sk);
568 	return !list_empty(&vsk->pending_links);
569 }
570 
571 static int vsock_send_shutdown(struct sock *sk, int mode)
572 {
573 	struct vsock_sock *vsk = vsock_sk(sk);
574 
575 	if (!vsk->transport)
576 		return -ENODEV;
577 
578 	return vsk->transport->shutdown(vsk, mode);
579 }
580 
581 static void vsock_pending_work(struct work_struct *work)
582 {
583 	struct sock *sk;
584 	struct sock *listener;
585 	struct vsock_sock *vsk;
586 	bool cleanup;
587 
588 	vsk = container_of(work, struct vsock_sock, pending_work.work);
589 	sk = sk_vsock(vsk);
590 	listener = vsk->listener;
591 	cleanup = true;
592 
593 	lock_sock(listener);
594 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
595 
596 	if (vsock_is_pending(sk)) {
597 		vsock_remove_pending(listener, sk);
598 
599 		sk_acceptq_removed(listener);
600 	} else if (!vsk->rejected) {
601 		/* We are not on the pending list and accept() did not reject
602 		 * us, so we must have been accepted by our user process.  We
603 		 * just need to drop our references to the sockets and be on
604 		 * our way.
605 		 */
606 		cleanup = false;
607 		goto out;
608 	}
609 
610 	/* We need to remove ourself from the global connected sockets list so
611 	 * incoming packets can't find this socket, and to reduce the reference
612 	 * count.
613 	 */
614 	vsock_remove_connected(vsk);
615 
616 	sk->sk_state = TCP_CLOSE;
617 
618 out:
619 	release_sock(sk);
620 	release_sock(listener);
621 	if (cleanup)
622 		sock_put(sk);
623 
624 	sock_put(sk);
625 	sock_put(listener);
626 }
627 
628 /**** SOCKET OPERATIONS ****/
629 
630 static int __vsock_bind_connectible(struct vsock_sock *vsk,
631 				    struct sockaddr_vm *addr)
632 {
633 	static u32 port;
634 	struct sockaddr_vm new_addr;
635 
636 	if (!port)
637 		port = get_random_u32_above(LAST_RESERVED_PORT);
638 
639 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
640 
641 	if (addr->svm_port == VMADDR_PORT_ANY) {
642 		bool found = false;
643 		unsigned int i;
644 
645 		for (i = 0; i < MAX_PORT_RETRIES; i++) {
646 			if (port <= LAST_RESERVED_PORT)
647 				port = LAST_RESERVED_PORT + 1;
648 
649 			new_addr.svm_port = port++;
650 
651 			if (!__vsock_find_bound_socket(&new_addr)) {
652 				found = true;
653 				break;
654 			}
655 		}
656 
657 		if (!found)
658 			return -EADDRNOTAVAIL;
659 	} else {
660 		/* If port is in reserved range, ensure caller
661 		 * has necessary privileges.
662 		 */
663 		if (addr->svm_port <= LAST_RESERVED_PORT &&
664 		    !capable(CAP_NET_BIND_SERVICE)) {
665 			return -EACCES;
666 		}
667 
668 		if (__vsock_find_bound_socket(&new_addr))
669 			return -EADDRINUSE;
670 	}
671 
672 	vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
673 
674 	/* Remove connection oriented sockets from the unbound list and add them
675 	 * to the hash table for easy lookup by its address.  The unbound list
676 	 * is simply an extra entry at the end of the hash table, a trick used
677 	 * by AF_UNIX.
678 	 */
679 	__vsock_remove_bound(vsk);
680 	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
681 
682 	return 0;
683 }
684 
685 static int __vsock_bind_dgram(struct vsock_sock *vsk,
686 			      struct sockaddr_vm *addr)
687 {
688 	return vsk->transport->dgram_bind(vsk, addr);
689 }
690 
691 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
692 {
693 	struct vsock_sock *vsk = vsock_sk(sk);
694 	int retval;
695 
696 	/* First ensure this socket isn't already bound. */
697 	if (vsock_addr_bound(&vsk->local_addr))
698 		return -EINVAL;
699 
700 	/* Now bind to the provided address or select appropriate values if
701 	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
702 	 * like AF_INET prevents binding to a non-local IP address (in most
703 	 * cases), we only allow binding to a local CID.
704 	 */
705 	if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
706 		return -EADDRNOTAVAIL;
707 
708 	switch (sk->sk_socket->type) {
709 	case SOCK_STREAM:
710 	case SOCK_SEQPACKET:
711 		spin_lock_bh(&vsock_table_lock);
712 		retval = __vsock_bind_connectible(vsk, addr);
713 		spin_unlock_bh(&vsock_table_lock);
714 		break;
715 
716 	case SOCK_DGRAM:
717 		retval = __vsock_bind_dgram(vsk, addr);
718 		break;
719 
720 	default:
721 		retval = -EINVAL;
722 		break;
723 	}
724 
725 	return retval;
726 }
727 
728 static void vsock_connect_timeout(struct work_struct *work);
729 
730 static struct sock *__vsock_create(struct net *net,
731 				   struct socket *sock,
732 				   struct sock *parent,
733 				   gfp_t priority,
734 				   unsigned short type,
735 				   int kern)
736 {
737 	struct sock *sk;
738 	struct vsock_sock *psk;
739 	struct vsock_sock *vsk;
740 
741 	sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
742 	if (!sk)
743 		return NULL;
744 
745 	sock_init_data(sock, sk);
746 
747 	/* sk->sk_type is normally set in sock_init_data, but only if sock is
748 	 * non-NULL. We make sure that our sockets always have a type by
749 	 * setting it here if needed.
750 	 */
751 	if (!sock)
752 		sk->sk_type = type;
753 
754 	vsk = vsock_sk(sk);
755 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
756 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
757 
758 	sk->sk_destruct = vsock_sk_destruct;
759 	sk->sk_backlog_rcv = vsock_queue_rcv_skb;
760 	sock_reset_flag(sk, SOCK_DONE);
761 
762 	INIT_LIST_HEAD(&vsk->bound_table);
763 	INIT_LIST_HEAD(&vsk->connected_table);
764 	vsk->listener = NULL;
765 	INIT_LIST_HEAD(&vsk->pending_links);
766 	INIT_LIST_HEAD(&vsk->accept_queue);
767 	vsk->rejected = false;
768 	vsk->sent_request = false;
769 	vsk->ignore_connecting_rst = false;
770 	vsk->peer_shutdown = 0;
771 	INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
772 	INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
773 
774 	psk = parent ? vsock_sk(parent) : NULL;
775 	if (parent) {
776 		vsk->trusted = psk->trusted;
777 		vsk->owner = get_cred(psk->owner);
778 		vsk->connect_timeout = psk->connect_timeout;
779 		vsk->buffer_size = psk->buffer_size;
780 		vsk->buffer_min_size = psk->buffer_min_size;
781 		vsk->buffer_max_size = psk->buffer_max_size;
782 		security_sk_clone(parent, sk);
783 	} else {
784 		vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
785 		vsk->owner = get_current_cred();
786 		vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
787 		vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
788 		vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
789 		vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
790 	}
791 
792 	return sk;
793 }
794 
795 static bool sock_type_connectible(u16 type)
796 {
797 	return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
798 }
799 
800 static void __vsock_release(struct sock *sk, int level)
801 {
802 	struct vsock_sock *vsk;
803 	struct sock *pending;
804 
805 	vsk = vsock_sk(sk);
806 	pending = NULL;	/* Compiler warning. */
807 
808 	/* When "level" is SINGLE_DEPTH_NESTING, use the nested
809 	 * version to avoid the warning "possible recursive locking
810 	 * detected". When "level" is 0, lock_sock_nested(sk, level)
811 	 * is the same as lock_sock(sk).
812 	 */
813 	lock_sock_nested(sk, level);
814 
815 	if (vsk->transport)
816 		vsk->transport->release(vsk);
817 	else if (sock_type_connectible(sk->sk_type))
818 		vsock_remove_sock(vsk);
819 
820 	sock_orphan(sk);
821 	sk->sk_shutdown = SHUTDOWN_MASK;
822 
823 	skb_queue_purge(&sk->sk_receive_queue);
824 
825 	/* Clean up any sockets that never were accepted. */
826 	while ((pending = vsock_dequeue_accept(sk)) != NULL) {
827 		__vsock_release(pending, SINGLE_DEPTH_NESTING);
828 		sock_put(pending);
829 	}
830 
831 	release_sock(sk);
832 	sock_put(sk);
833 }
834 
835 static void vsock_sk_destruct(struct sock *sk)
836 {
837 	struct vsock_sock *vsk = vsock_sk(sk);
838 
839 	/* Flush MSG_ZEROCOPY leftovers. */
840 	__skb_queue_purge(&sk->sk_error_queue);
841 
842 	vsock_deassign_transport(vsk);
843 
844 	/* When clearing these addresses, there's no need to set the family and
845 	 * possibly register the address family with the kernel.
846 	 */
847 	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
848 	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
849 
850 	put_cred(vsk->owner);
851 }
852 
853 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
854 {
855 	int err;
856 
857 	err = sock_queue_rcv_skb(sk, skb);
858 	if (err)
859 		kfree_skb(skb);
860 
861 	return err;
862 }
863 
864 struct sock *vsock_create_connected(struct sock *parent)
865 {
866 	return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
867 			      parent->sk_type, 0);
868 }
869 EXPORT_SYMBOL_GPL(vsock_create_connected);
870 
871 s64 vsock_stream_has_data(struct vsock_sock *vsk)
872 {
873 	return vsk->transport->stream_has_data(vsk);
874 }
875 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
876 
877 s64 vsock_connectible_has_data(struct vsock_sock *vsk)
878 {
879 	struct sock *sk = sk_vsock(vsk);
880 
881 	if (sk->sk_type == SOCK_SEQPACKET)
882 		return vsk->transport->seqpacket_has_data(vsk);
883 	else
884 		return vsock_stream_has_data(vsk);
885 }
886 EXPORT_SYMBOL_GPL(vsock_connectible_has_data);
887 
888 s64 vsock_stream_has_space(struct vsock_sock *vsk)
889 {
890 	return vsk->transport->stream_has_space(vsk);
891 }
892 EXPORT_SYMBOL_GPL(vsock_stream_has_space);
893 
894 void vsock_data_ready(struct sock *sk)
895 {
896 	struct vsock_sock *vsk = vsock_sk(sk);
897 
898 	if (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
899 	    sock_flag(sk, SOCK_DONE))
900 		sk->sk_data_ready(sk);
901 }
902 EXPORT_SYMBOL_GPL(vsock_data_ready);
903 
904 /* Dummy callback required by sockmap.
905  * See unconditional call of saved_close() in sock_map_close().
906  */
907 static void vsock_close(struct sock *sk, long timeout)
908 {
909 }
910 
911 static int vsock_release(struct socket *sock)
912 {
913 	struct sock *sk = sock->sk;
914 
915 	if (!sk)
916 		return 0;
917 
918 	sk->sk_prot->close(sk, 0);
919 	__vsock_release(sk, 0);
920 	sock->sk = NULL;
921 	sock->state = SS_FREE;
922 
923 	return 0;
924 }
925 
926 static int
927 vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
928 {
929 	int err;
930 	struct sock *sk;
931 	struct sockaddr_vm *vm_addr;
932 
933 	sk = sock->sk;
934 
935 	if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
936 		return -EINVAL;
937 
938 	lock_sock(sk);
939 	err = __vsock_bind(sk, vm_addr);
940 	release_sock(sk);
941 
942 	return err;
943 }
944 
945 static int vsock_getname(struct socket *sock,
946 			 struct sockaddr *addr, int peer)
947 {
948 	int err;
949 	struct sock *sk;
950 	struct vsock_sock *vsk;
951 	struct sockaddr_vm *vm_addr;
952 
953 	sk = sock->sk;
954 	vsk = vsock_sk(sk);
955 	err = 0;
956 
957 	lock_sock(sk);
958 
959 	if (peer) {
960 		if (sock->state != SS_CONNECTED) {
961 			err = -ENOTCONN;
962 			goto out;
963 		}
964 		vm_addr = &vsk->remote_addr;
965 	} else {
966 		vm_addr = &vsk->local_addr;
967 	}
968 
969 	if (!vm_addr) {
970 		err = -EINVAL;
971 		goto out;
972 	}
973 
974 	/* sys_getsockname() and sys_getpeername() pass us a
975 	 * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
976 	 * that macro is defined in socket.c instead of .h, so we hardcode its
977 	 * value here.
978 	 */
979 	BUILD_BUG_ON(sizeof(*vm_addr) > 128);
980 	memcpy(addr, vm_addr, sizeof(*vm_addr));
981 	err = sizeof(*vm_addr);
982 
983 out:
984 	release_sock(sk);
985 	return err;
986 }
987 
988 static int vsock_shutdown(struct socket *sock, int mode)
989 {
990 	int err;
991 	struct sock *sk;
992 
993 	/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
994 	 * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
995 	 * here like the other address families do.  Note also that the
996 	 * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
997 	 * which is what we want.
998 	 */
999 	mode++;
1000 
1001 	if ((mode & ~SHUTDOWN_MASK) || !mode)
1002 		return -EINVAL;
1003 
1004 	/* If this is a connection oriented socket and it is not connected then
1005 	 * bail out immediately.  If it is a DGRAM socket then we must first
1006 	 * kick the socket so that it wakes up from any sleeping calls, for
1007 	 * example recv(), and then afterwards return the error.
1008 	 */
1009 
1010 	sk = sock->sk;
1011 
1012 	lock_sock(sk);
1013 	if (sock->state == SS_UNCONNECTED) {
1014 		err = -ENOTCONN;
1015 		if (sock_type_connectible(sk->sk_type))
1016 			goto out;
1017 	} else {
1018 		sock->state = SS_DISCONNECTING;
1019 		err = 0;
1020 	}
1021 
1022 	/* Receive and send shutdowns are treated alike. */
1023 	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
1024 	if (mode) {
1025 		sk->sk_shutdown |= mode;
1026 		sk->sk_state_change(sk);
1027 
1028 		if (sock_type_connectible(sk->sk_type)) {
1029 			sock_reset_flag(sk, SOCK_DONE);
1030 			vsock_send_shutdown(sk, mode);
1031 		}
1032 	}
1033 
1034 out:
1035 	release_sock(sk);
1036 	return err;
1037 }
1038 
1039 static __poll_t vsock_poll(struct file *file, struct socket *sock,
1040 			       poll_table *wait)
1041 {
1042 	struct sock *sk;
1043 	__poll_t mask;
1044 	struct vsock_sock *vsk;
1045 
1046 	sk = sock->sk;
1047 	vsk = vsock_sk(sk);
1048 
1049 	poll_wait(file, sk_sleep(sk), wait);
1050 	mask = 0;
1051 
1052 	if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
1053 		/* Signify that there has been an error on this socket. */
1054 		mask |= EPOLLERR;
1055 
1056 	/* INET sockets treat local write shutdown and peer write shutdown as a
1057 	 * case of EPOLLHUP set.
1058 	 */
1059 	if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
1060 	    ((sk->sk_shutdown & SEND_SHUTDOWN) &&
1061 	     (vsk->peer_shutdown & SEND_SHUTDOWN))) {
1062 		mask |= EPOLLHUP;
1063 	}
1064 
1065 	if (sk->sk_shutdown & RCV_SHUTDOWN ||
1066 	    vsk->peer_shutdown & SEND_SHUTDOWN) {
1067 		mask |= EPOLLRDHUP;
1068 	}
1069 
1070 	if (sk_is_readable(sk))
1071 		mask |= EPOLLIN | EPOLLRDNORM;
1072 
1073 	if (sock->type == SOCK_DGRAM) {
1074 		/* For datagram sockets we can read if there is something in
1075 		 * the queue and write as long as the socket isn't shutdown for
1076 		 * sending.
1077 		 */
1078 		if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1079 		    (sk->sk_shutdown & RCV_SHUTDOWN)) {
1080 			mask |= EPOLLIN | EPOLLRDNORM;
1081 		}
1082 
1083 		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1084 			mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1085 
1086 	} else if (sock_type_connectible(sk->sk_type)) {
1087 		const struct vsock_transport *transport;
1088 
1089 		lock_sock(sk);
1090 
1091 		transport = vsk->transport;
1092 
1093 		/* Listening sockets that have connections in their accept
1094 		 * queue can be read.
1095 		 */
1096 		if (sk->sk_state == TCP_LISTEN
1097 		    && !vsock_is_accept_queue_empty(sk))
1098 			mask |= EPOLLIN | EPOLLRDNORM;
1099 
1100 		/* If there is something in the queue then we can read. */
1101 		if (transport && transport->stream_is_active(vsk) &&
1102 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1103 			bool data_ready_now = false;
1104 			int target = sock_rcvlowat(sk, 0, INT_MAX);
1105 			int ret = transport->notify_poll_in(
1106 					vsk, target, &data_ready_now);
1107 			if (ret < 0) {
1108 				mask |= EPOLLERR;
1109 			} else {
1110 				if (data_ready_now)
1111 					mask |= EPOLLIN | EPOLLRDNORM;
1112 
1113 			}
1114 		}
1115 
1116 		/* Sockets whose connections have been closed, reset, or
1117 		 * terminated should also be considered read, and we check the
1118 		 * shutdown flag for that.
1119 		 */
1120 		if (sk->sk_shutdown & RCV_SHUTDOWN ||
1121 		    vsk->peer_shutdown & SEND_SHUTDOWN) {
1122 			mask |= EPOLLIN | EPOLLRDNORM;
1123 		}
1124 
1125 		/* Connected sockets that can produce data can be written. */
1126 		if (transport && sk->sk_state == TCP_ESTABLISHED) {
1127 			if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1128 				bool space_avail_now = false;
1129 				int ret = transport->notify_poll_out(
1130 						vsk, 1, &space_avail_now);
1131 				if (ret < 0) {
1132 					mask |= EPOLLERR;
1133 				} else {
1134 					if (space_avail_now)
1135 						/* Remove EPOLLWRBAND since INET
1136 						 * sockets are not setting it.
1137 						 */
1138 						mask |= EPOLLOUT | EPOLLWRNORM;
1139 
1140 				}
1141 			}
1142 		}
1143 
1144 		/* Simulate INET socket poll behaviors, which sets
1145 		 * EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
1146 		 * but local send is not shutdown.
1147 		 */
1148 		if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
1149 			if (!(sk->sk_shutdown & SEND_SHUTDOWN))
1150 				mask |= EPOLLOUT | EPOLLWRNORM;
1151 
1152 		}
1153 
1154 		release_sock(sk);
1155 	}
1156 
1157 	return mask;
1158 }
1159 
1160 static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor)
1161 {
1162 	struct vsock_sock *vsk = vsock_sk(sk);
1163 
1164 	return vsk->transport->read_skb(vsk, read_actor);
1165 }
1166 
1167 static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
1168 			       size_t len)
1169 {
1170 	int err;
1171 	struct sock *sk;
1172 	struct vsock_sock *vsk;
1173 	struct sockaddr_vm *remote_addr;
1174 	const struct vsock_transport *transport;
1175 
1176 	if (msg->msg_flags & MSG_OOB)
1177 		return -EOPNOTSUPP;
1178 
1179 	/* For now, MSG_DONTWAIT is always assumed... */
1180 	err = 0;
1181 	sk = sock->sk;
1182 	vsk = vsock_sk(sk);
1183 
1184 	lock_sock(sk);
1185 
1186 	transport = vsk->transport;
1187 
1188 	err = vsock_auto_bind(vsk);
1189 	if (err)
1190 		goto out;
1191 
1192 
1193 	/* If the provided message contains an address, use that.  Otherwise
1194 	 * fall back on the socket's remote handle (if it has been connected).
1195 	 */
1196 	if (msg->msg_name &&
1197 	    vsock_addr_cast(msg->msg_name, msg->msg_namelen,
1198 			    &remote_addr) == 0) {
1199 		/* Ensure this address is of the right type and is a valid
1200 		 * destination.
1201 		 */
1202 
1203 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1204 			remote_addr->svm_cid = transport->get_local_cid();
1205 
1206 		if (!vsock_addr_bound(remote_addr)) {
1207 			err = -EINVAL;
1208 			goto out;
1209 		}
1210 	} else if (sock->state == SS_CONNECTED) {
1211 		remote_addr = &vsk->remote_addr;
1212 
1213 		if (remote_addr->svm_cid == VMADDR_CID_ANY)
1214 			remote_addr->svm_cid = transport->get_local_cid();
1215 
1216 		/* XXX Should connect() or this function ensure remote_addr is
1217 		 * bound?
1218 		 */
1219 		if (!vsock_addr_bound(&vsk->remote_addr)) {
1220 			err = -EINVAL;
1221 			goto out;
1222 		}
1223 	} else {
1224 		err = -EINVAL;
1225 		goto out;
1226 	}
1227 
1228 	if (!transport->dgram_allow(remote_addr->svm_cid,
1229 				    remote_addr->svm_port)) {
1230 		err = -EINVAL;
1231 		goto out;
1232 	}
1233 
1234 	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
1235 
1236 out:
1237 	release_sock(sk);
1238 	return err;
1239 }
1240 
1241 static int vsock_dgram_connect(struct socket *sock,
1242 			       struct sockaddr *addr, int addr_len, int flags)
1243 {
1244 	int err;
1245 	struct sock *sk;
1246 	struct vsock_sock *vsk;
1247 	struct sockaddr_vm *remote_addr;
1248 
1249 	sk = sock->sk;
1250 	vsk = vsock_sk(sk);
1251 
1252 	err = vsock_addr_cast(addr, addr_len, &remote_addr);
1253 	if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
1254 		lock_sock(sk);
1255 		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
1256 				VMADDR_PORT_ANY);
1257 		sock->state = SS_UNCONNECTED;
1258 		release_sock(sk);
1259 		return 0;
1260 	} else if (err != 0)
1261 		return -EINVAL;
1262 
1263 	lock_sock(sk);
1264 
1265 	err = vsock_auto_bind(vsk);
1266 	if (err)
1267 		goto out;
1268 
1269 	if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
1270 					 remote_addr->svm_port)) {
1271 		err = -EINVAL;
1272 		goto out;
1273 	}
1274 
1275 	memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
1276 	sock->state = SS_CONNECTED;
1277 
1278 	/* sock map disallows redirection of non-TCP sockets with sk_state !=
1279 	 * TCP_ESTABLISHED (see sock_map_redirect_allowed()), so we set
1280 	 * TCP_ESTABLISHED here to allow redirection of connected vsock dgrams.
1281 	 *
1282 	 * This doesn't seem to be abnormal state for datagram sockets, as the
1283 	 * same approach can be see in other datagram socket types as well
1284 	 * (such as unix sockets).
1285 	 */
1286 	sk->sk_state = TCP_ESTABLISHED;
1287 
1288 out:
1289 	release_sock(sk);
1290 	return err;
1291 }
1292 
1293 int __vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1294 			  size_t len, int flags)
1295 {
1296 	struct sock *sk = sock->sk;
1297 	struct vsock_sock *vsk = vsock_sk(sk);
1298 
1299 	return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
1300 }
1301 
1302 int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
1303 			size_t len, int flags)
1304 {
1305 #ifdef CONFIG_BPF_SYSCALL
1306 	struct sock *sk = sock->sk;
1307 	const struct proto *prot;
1308 
1309 	prot = READ_ONCE(sk->sk_prot);
1310 	if (prot != &vsock_proto)
1311 		return prot->recvmsg(sk, msg, len, flags, NULL);
1312 #endif
1313 
1314 	return __vsock_dgram_recvmsg(sock, msg, len, flags);
1315 }
1316 EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
1317 
1318 static int vsock_do_ioctl(struct socket *sock, unsigned int cmd,
1319 			  int __user *arg)
1320 {
1321 	struct sock *sk = sock->sk;
1322 	struct vsock_sock *vsk;
1323 	int ret;
1324 
1325 	vsk = vsock_sk(sk);
1326 
1327 	switch (cmd) {
1328 	case SIOCOUTQ: {
1329 		ssize_t n_bytes;
1330 
1331 		if (!vsk->transport || !vsk->transport->unsent_bytes) {
1332 			ret = -EOPNOTSUPP;
1333 			break;
1334 		}
1335 
1336 		if (sock_type_connectible(sk->sk_type) && sk->sk_state == TCP_LISTEN) {
1337 			ret = -EINVAL;
1338 			break;
1339 		}
1340 
1341 		n_bytes = vsk->transport->unsent_bytes(vsk);
1342 		if (n_bytes < 0) {
1343 			ret = n_bytes;
1344 			break;
1345 		}
1346 
1347 		ret = put_user(n_bytes, arg);
1348 		break;
1349 	}
1350 	default:
1351 		ret = -ENOIOCTLCMD;
1352 	}
1353 
1354 	return ret;
1355 }
1356 
1357 static int vsock_ioctl(struct socket *sock, unsigned int cmd,
1358 		       unsigned long arg)
1359 {
1360 	int ret;
1361 
1362 	lock_sock(sock->sk);
1363 	ret = vsock_do_ioctl(sock, cmd, (int __user *)arg);
1364 	release_sock(sock->sk);
1365 
1366 	return ret;
1367 }
1368 
1369 static const struct proto_ops vsock_dgram_ops = {
1370 	.family = PF_VSOCK,
1371 	.owner = THIS_MODULE,
1372 	.release = vsock_release,
1373 	.bind = vsock_bind,
1374 	.connect = vsock_dgram_connect,
1375 	.socketpair = sock_no_socketpair,
1376 	.accept = sock_no_accept,
1377 	.getname = vsock_getname,
1378 	.poll = vsock_poll,
1379 	.ioctl = vsock_ioctl,
1380 	.listen = sock_no_listen,
1381 	.shutdown = vsock_shutdown,
1382 	.sendmsg = vsock_dgram_sendmsg,
1383 	.recvmsg = vsock_dgram_recvmsg,
1384 	.mmap = sock_no_mmap,
1385 	.read_skb = vsock_read_skb,
1386 };
1387 
1388 static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
1389 {
1390 	const struct vsock_transport *transport = vsk->transport;
1391 
1392 	if (!transport || !transport->cancel_pkt)
1393 		return -EOPNOTSUPP;
1394 
1395 	return transport->cancel_pkt(vsk);
1396 }
1397 
1398 static void vsock_connect_timeout(struct work_struct *work)
1399 {
1400 	struct sock *sk;
1401 	struct vsock_sock *vsk;
1402 
1403 	vsk = container_of(work, struct vsock_sock, connect_work.work);
1404 	sk = sk_vsock(vsk);
1405 
1406 	lock_sock(sk);
1407 	if (sk->sk_state == TCP_SYN_SENT &&
1408 	    (sk->sk_shutdown != SHUTDOWN_MASK)) {
1409 		sk->sk_state = TCP_CLOSE;
1410 		sk->sk_socket->state = SS_UNCONNECTED;
1411 		sk->sk_err = ETIMEDOUT;
1412 		sk_error_report(sk);
1413 		vsock_transport_cancel_pkt(vsk);
1414 	}
1415 	release_sock(sk);
1416 
1417 	sock_put(sk);
1418 }
1419 
1420 static int vsock_connect(struct socket *sock, struct sockaddr *addr,
1421 			 int addr_len, int flags)
1422 {
1423 	int err;
1424 	struct sock *sk;
1425 	struct vsock_sock *vsk;
1426 	const struct vsock_transport *transport;
1427 	struct sockaddr_vm *remote_addr;
1428 	long timeout;
1429 	DEFINE_WAIT(wait);
1430 
1431 	err = 0;
1432 	sk = sock->sk;
1433 	vsk = vsock_sk(sk);
1434 
1435 	lock_sock(sk);
1436 
1437 	/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
1438 	switch (sock->state) {
1439 	case SS_CONNECTED:
1440 		err = -EISCONN;
1441 		goto out;
1442 	case SS_DISCONNECTING:
1443 		err = -EINVAL;
1444 		goto out;
1445 	case SS_CONNECTING:
1446 		/* This continues on so we can move sock into the SS_CONNECTED
1447 		 * state once the connection has completed (at which point err
1448 		 * will be set to zero also).  Otherwise, we will either wait
1449 		 * for the connection or return -EALREADY should this be a
1450 		 * non-blocking call.
1451 		 */
1452 		err = -EALREADY;
1453 		if (flags & O_NONBLOCK)
1454 			goto out;
1455 		break;
1456 	default:
1457 		if ((sk->sk_state == TCP_LISTEN) ||
1458 		    vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
1459 			err = -EINVAL;
1460 			goto out;
1461 		}
1462 
1463 		/* Set the remote address that we are connecting to. */
1464 		memcpy(&vsk->remote_addr, remote_addr,
1465 		       sizeof(vsk->remote_addr));
1466 
1467 		err = vsock_assign_transport(vsk, NULL);
1468 		if (err)
1469 			goto out;
1470 
1471 		transport = vsk->transport;
1472 
1473 		/* The hypervisor and well-known contexts do not have socket
1474 		 * endpoints.
1475 		 */
1476 		if (!transport ||
1477 		    !transport->stream_allow(remote_addr->svm_cid,
1478 					     remote_addr->svm_port)) {
1479 			err = -ENETUNREACH;
1480 			goto out;
1481 		}
1482 
1483 		if (vsock_msgzerocopy_allow(transport)) {
1484 			set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1485 		} else if (sock_flag(sk, SOCK_ZEROCOPY)) {
1486 			/* If this option was set before 'connect()',
1487 			 * when transport was unknown, check that this
1488 			 * feature is supported here.
1489 			 */
1490 			err = -EOPNOTSUPP;
1491 			goto out;
1492 		}
1493 
1494 		err = vsock_auto_bind(vsk);
1495 		if (err)
1496 			goto out;
1497 
1498 		sk->sk_state = TCP_SYN_SENT;
1499 
1500 		err = transport->connect(vsk);
1501 		if (err < 0)
1502 			goto out;
1503 
1504 		/* Mark sock as connecting and set the error code to in
1505 		 * progress in case this is a non-blocking connect.
1506 		 */
1507 		sock->state = SS_CONNECTING;
1508 		err = -EINPROGRESS;
1509 	}
1510 
1511 	/* The receive path will handle all communication until we are able to
1512 	 * enter the connected state.  Here we wait for the connection to be
1513 	 * completed or a notification of an error.
1514 	 */
1515 	timeout = vsk->connect_timeout;
1516 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1517 
1518 	while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
1519 		if (flags & O_NONBLOCK) {
1520 			/* If we're not going to block, we schedule a timeout
1521 			 * function to generate a timeout on the connection
1522 			 * attempt, in case the peer doesn't respond in a
1523 			 * timely manner. We hold on to the socket until the
1524 			 * timeout fires.
1525 			 */
1526 			sock_hold(sk);
1527 
1528 			/* If the timeout function is already scheduled,
1529 			 * reschedule it, then ungrab the socket refcount to
1530 			 * keep it balanced.
1531 			 */
1532 			if (mod_delayed_work(system_wq, &vsk->connect_work,
1533 					     timeout))
1534 				sock_put(sk);
1535 
1536 			/* Skip ahead to preserve error code set above. */
1537 			goto out_wait;
1538 		}
1539 
1540 		release_sock(sk);
1541 		timeout = schedule_timeout(timeout);
1542 		lock_sock(sk);
1543 
1544 		if (signal_pending(current)) {
1545 			err = sock_intr_errno(timeout);
1546 			sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
1547 			sock->state = SS_UNCONNECTED;
1548 			vsock_transport_cancel_pkt(vsk);
1549 			vsock_remove_connected(vsk);
1550 			goto out_wait;
1551 		} else if ((sk->sk_state != TCP_ESTABLISHED) && (timeout == 0)) {
1552 			err = -ETIMEDOUT;
1553 			sk->sk_state = TCP_CLOSE;
1554 			sock->state = SS_UNCONNECTED;
1555 			vsock_transport_cancel_pkt(vsk);
1556 			goto out_wait;
1557 		}
1558 
1559 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1560 	}
1561 
1562 	if (sk->sk_err) {
1563 		err = -sk->sk_err;
1564 		sk->sk_state = TCP_CLOSE;
1565 		sock->state = SS_UNCONNECTED;
1566 	} else {
1567 		err = 0;
1568 	}
1569 
1570 out_wait:
1571 	finish_wait(sk_sleep(sk), &wait);
1572 out:
1573 	release_sock(sk);
1574 	return err;
1575 }
1576 
1577 static int vsock_accept(struct socket *sock, struct socket *newsock,
1578 			struct proto_accept_arg *arg)
1579 {
1580 	struct sock *listener;
1581 	int err;
1582 	struct sock *connected;
1583 	struct vsock_sock *vconnected;
1584 	long timeout;
1585 	DEFINE_WAIT(wait);
1586 
1587 	err = 0;
1588 	listener = sock->sk;
1589 
1590 	lock_sock(listener);
1591 
1592 	if (!sock_type_connectible(sock->type)) {
1593 		err = -EOPNOTSUPP;
1594 		goto out;
1595 	}
1596 
1597 	if (listener->sk_state != TCP_LISTEN) {
1598 		err = -EINVAL;
1599 		goto out;
1600 	}
1601 
1602 	/* Wait for children sockets to appear; these are the new sockets
1603 	 * created upon connection establishment.
1604 	 */
1605 	timeout = sock_rcvtimeo(listener, arg->flags & O_NONBLOCK);
1606 	prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1607 
1608 	while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1609 	       listener->sk_err == 0) {
1610 		release_sock(listener);
1611 		timeout = schedule_timeout(timeout);
1612 		finish_wait(sk_sleep(listener), &wait);
1613 		lock_sock(listener);
1614 
1615 		if (signal_pending(current)) {
1616 			err = sock_intr_errno(timeout);
1617 			goto out;
1618 		} else if (timeout == 0) {
1619 			err = -EAGAIN;
1620 			goto out;
1621 		}
1622 
1623 		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1624 	}
1625 	finish_wait(sk_sleep(listener), &wait);
1626 
1627 	if (listener->sk_err)
1628 		err = -listener->sk_err;
1629 
1630 	if (connected) {
1631 		sk_acceptq_removed(listener);
1632 
1633 		lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1634 		vconnected = vsock_sk(connected);
1635 
1636 		/* If the listener socket has received an error, then we should
1637 		 * reject this socket and return.  Note that we simply mark the
1638 		 * socket rejected, drop our reference, and let the cleanup
1639 		 * function handle the cleanup; the fact that we found it in
1640 		 * the listener's accept queue guarantees that the cleanup
1641 		 * function hasn't run yet.
1642 		 */
1643 		if (err) {
1644 			vconnected->rejected = true;
1645 		} else {
1646 			newsock->state = SS_CONNECTED;
1647 			sock_graft(connected, newsock);
1648 			if (vsock_msgzerocopy_allow(vconnected->transport))
1649 				set_bit(SOCK_SUPPORT_ZC,
1650 					&connected->sk_socket->flags);
1651 		}
1652 
1653 		release_sock(connected);
1654 		sock_put(connected);
1655 	}
1656 
1657 out:
1658 	release_sock(listener);
1659 	return err;
1660 }
1661 
1662 static int vsock_listen(struct socket *sock, int backlog)
1663 {
1664 	int err;
1665 	struct sock *sk;
1666 	struct vsock_sock *vsk;
1667 
1668 	sk = sock->sk;
1669 
1670 	lock_sock(sk);
1671 
1672 	if (!sock_type_connectible(sk->sk_type)) {
1673 		err = -EOPNOTSUPP;
1674 		goto out;
1675 	}
1676 
1677 	if (sock->state != SS_UNCONNECTED) {
1678 		err = -EINVAL;
1679 		goto out;
1680 	}
1681 
1682 	vsk = vsock_sk(sk);
1683 
1684 	if (!vsock_addr_bound(&vsk->local_addr)) {
1685 		err = -EINVAL;
1686 		goto out;
1687 	}
1688 
1689 	sk->sk_max_ack_backlog = backlog;
1690 	sk->sk_state = TCP_LISTEN;
1691 
1692 	err = 0;
1693 
1694 out:
1695 	release_sock(sk);
1696 	return err;
1697 }
1698 
1699 static void vsock_update_buffer_size(struct vsock_sock *vsk,
1700 				     const struct vsock_transport *transport,
1701 				     u64 val)
1702 {
1703 	if (val > vsk->buffer_max_size)
1704 		val = vsk->buffer_max_size;
1705 
1706 	if (val < vsk->buffer_min_size)
1707 		val = vsk->buffer_min_size;
1708 
1709 	if (val != vsk->buffer_size &&
1710 	    transport && transport->notify_buffer_size)
1711 		transport->notify_buffer_size(vsk, &val);
1712 
1713 	vsk->buffer_size = val;
1714 }
1715 
1716 static int vsock_connectible_setsockopt(struct socket *sock,
1717 					int level,
1718 					int optname,
1719 					sockptr_t optval,
1720 					unsigned int optlen)
1721 {
1722 	int err;
1723 	struct sock *sk;
1724 	struct vsock_sock *vsk;
1725 	const struct vsock_transport *transport;
1726 	u64 val;
1727 
1728 	if (level != AF_VSOCK && level != SOL_SOCKET)
1729 		return -ENOPROTOOPT;
1730 
1731 #define COPY_IN(_v)                                       \
1732 	do {						  \
1733 		if (optlen < sizeof(_v)) {		  \
1734 			err = -EINVAL;			  \
1735 			goto exit;			  \
1736 		}					  \
1737 		if (copy_from_sockptr(&_v, optval, sizeof(_v)) != 0) {	\
1738 			err = -EFAULT;					\
1739 			goto exit;					\
1740 		}							\
1741 	} while (0)
1742 
1743 	err = 0;
1744 	sk = sock->sk;
1745 	vsk = vsock_sk(sk);
1746 
1747 	lock_sock(sk);
1748 
1749 	transport = vsk->transport;
1750 
1751 	if (level == SOL_SOCKET) {
1752 		int zerocopy;
1753 
1754 		if (optname != SO_ZEROCOPY) {
1755 			release_sock(sk);
1756 			return sock_setsockopt(sock, level, optname, optval, optlen);
1757 		}
1758 
1759 		/* Use 'int' type here, because variable to
1760 		 * set this option usually has this type.
1761 		 */
1762 		COPY_IN(zerocopy);
1763 
1764 		if (zerocopy < 0 || zerocopy > 1) {
1765 			err = -EINVAL;
1766 			goto exit;
1767 		}
1768 
1769 		if (transport && !vsock_msgzerocopy_allow(transport)) {
1770 			err = -EOPNOTSUPP;
1771 			goto exit;
1772 		}
1773 
1774 		sock_valbool_flag(sk, SOCK_ZEROCOPY, zerocopy);
1775 		goto exit;
1776 	}
1777 
1778 	switch (optname) {
1779 	case SO_VM_SOCKETS_BUFFER_SIZE:
1780 		COPY_IN(val);
1781 		vsock_update_buffer_size(vsk, transport, val);
1782 		break;
1783 
1784 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1785 		COPY_IN(val);
1786 		vsk->buffer_max_size = val;
1787 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1788 		break;
1789 
1790 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1791 		COPY_IN(val);
1792 		vsk->buffer_min_size = val;
1793 		vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
1794 		break;
1795 
1796 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1797 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD: {
1798 		struct __kernel_sock_timeval tv;
1799 
1800 		err = sock_copy_user_timeval(&tv, optval, optlen,
1801 					     optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1802 		if (err)
1803 			break;
1804 		if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
1805 		    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
1806 			vsk->connect_timeout = tv.tv_sec * HZ +
1807 				DIV_ROUND_UP((unsigned long)tv.tv_usec, (USEC_PER_SEC / HZ));
1808 			if (vsk->connect_timeout == 0)
1809 				vsk->connect_timeout =
1810 				    VSOCK_DEFAULT_CONNECT_TIMEOUT;
1811 
1812 		} else {
1813 			err = -ERANGE;
1814 		}
1815 		break;
1816 	}
1817 
1818 	default:
1819 		err = -ENOPROTOOPT;
1820 		break;
1821 	}
1822 
1823 #undef COPY_IN
1824 
1825 exit:
1826 	release_sock(sk);
1827 	return err;
1828 }
1829 
1830 static int vsock_connectible_getsockopt(struct socket *sock,
1831 					int level, int optname,
1832 					char __user *optval,
1833 					int __user *optlen)
1834 {
1835 	struct sock *sk = sock->sk;
1836 	struct vsock_sock *vsk = vsock_sk(sk);
1837 
1838 	union {
1839 		u64 val64;
1840 		struct old_timeval32 tm32;
1841 		struct __kernel_old_timeval tm;
1842 		struct  __kernel_sock_timeval stm;
1843 	} v;
1844 
1845 	int lv = sizeof(v.val64);
1846 	int len;
1847 
1848 	if (level != AF_VSOCK)
1849 		return -ENOPROTOOPT;
1850 
1851 	if (get_user(len, optlen))
1852 		return -EFAULT;
1853 
1854 	memset(&v, 0, sizeof(v));
1855 
1856 	switch (optname) {
1857 	case SO_VM_SOCKETS_BUFFER_SIZE:
1858 		v.val64 = vsk->buffer_size;
1859 		break;
1860 
1861 	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
1862 		v.val64 = vsk->buffer_max_size;
1863 		break;
1864 
1865 	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
1866 		v.val64 = vsk->buffer_min_size;
1867 		break;
1868 
1869 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW:
1870 	case SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD:
1871 		lv = sock_get_timeout(vsk->connect_timeout, &v,
1872 				      optname == SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
1873 		break;
1874 
1875 	default:
1876 		return -ENOPROTOOPT;
1877 	}
1878 
1879 	if (len < lv)
1880 		return -EINVAL;
1881 	if (len > lv)
1882 		len = lv;
1883 	if (copy_to_user(optval, &v, len))
1884 		return -EFAULT;
1885 
1886 	if (put_user(len, optlen))
1887 		return -EFAULT;
1888 
1889 	return 0;
1890 }
1891 
1892 static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
1893 				     size_t len)
1894 {
1895 	struct sock *sk;
1896 	struct vsock_sock *vsk;
1897 	const struct vsock_transport *transport;
1898 	ssize_t total_written;
1899 	long timeout;
1900 	int err;
1901 	struct vsock_transport_send_notify_data send_data;
1902 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1903 
1904 	sk = sock->sk;
1905 	vsk = vsock_sk(sk);
1906 	total_written = 0;
1907 	err = 0;
1908 
1909 	if (msg->msg_flags & MSG_OOB)
1910 		return -EOPNOTSUPP;
1911 
1912 	lock_sock(sk);
1913 
1914 	transport = vsk->transport;
1915 
1916 	/* Callers should not provide a destination with connection oriented
1917 	 * sockets.
1918 	 */
1919 	if (msg->msg_namelen) {
1920 		err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
1921 		goto out;
1922 	}
1923 
1924 	/* Send data only if both sides are not shutdown in the direction. */
1925 	if (sk->sk_shutdown & SEND_SHUTDOWN ||
1926 	    vsk->peer_shutdown & RCV_SHUTDOWN) {
1927 		err = -EPIPE;
1928 		goto out;
1929 	}
1930 
1931 	if (!transport || sk->sk_state != TCP_ESTABLISHED ||
1932 	    !vsock_addr_bound(&vsk->local_addr)) {
1933 		err = -ENOTCONN;
1934 		goto out;
1935 	}
1936 
1937 	if (!vsock_addr_bound(&vsk->remote_addr)) {
1938 		err = -EDESTADDRREQ;
1939 		goto out;
1940 	}
1941 
1942 	if (msg->msg_flags & MSG_ZEROCOPY &&
1943 	    !vsock_msgzerocopy_allow(transport)) {
1944 		err = -EOPNOTSUPP;
1945 		goto out;
1946 	}
1947 
1948 	/* Wait for room in the produce queue to enqueue our user's data. */
1949 	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1950 
1951 	err = transport->notify_send_init(vsk, &send_data);
1952 	if (err < 0)
1953 		goto out;
1954 
1955 	while (total_written < len) {
1956 		ssize_t written;
1957 
1958 		add_wait_queue(sk_sleep(sk), &wait);
1959 		while (vsock_stream_has_space(vsk) == 0 &&
1960 		       sk->sk_err == 0 &&
1961 		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
1962 		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
1963 
1964 			/* Don't wait for non-blocking sockets. */
1965 			if (timeout == 0) {
1966 				err = -EAGAIN;
1967 				remove_wait_queue(sk_sleep(sk), &wait);
1968 				goto out_err;
1969 			}
1970 
1971 			err = transport->notify_send_pre_block(vsk, &send_data);
1972 			if (err < 0) {
1973 				remove_wait_queue(sk_sleep(sk), &wait);
1974 				goto out_err;
1975 			}
1976 
1977 			release_sock(sk);
1978 			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
1979 			lock_sock(sk);
1980 			if (signal_pending(current)) {
1981 				err = sock_intr_errno(timeout);
1982 				remove_wait_queue(sk_sleep(sk), &wait);
1983 				goto out_err;
1984 			} else if (timeout == 0) {
1985 				err = -EAGAIN;
1986 				remove_wait_queue(sk_sleep(sk), &wait);
1987 				goto out_err;
1988 			}
1989 		}
1990 		remove_wait_queue(sk_sleep(sk), &wait);
1991 
1992 		/* These checks occur both as part of and after the loop
1993 		 * conditional since we need to check before and after
1994 		 * sleeping.
1995 		 */
1996 		if (sk->sk_err) {
1997 			err = -sk->sk_err;
1998 			goto out_err;
1999 		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
2000 			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
2001 			err = -EPIPE;
2002 			goto out_err;
2003 		}
2004 
2005 		err = transport->notify_send_pre_enqueue(vsk, &send_data);
2006 		if (err < 0)
2007 			goto out_err;
2008 
2009 		/* Note that enqueue will only write as many bytes as are free
2010 		 * in the produce queue, so we don't need to ensure len is
2011 		 * smaller than the queue size.  It is the caller's
2012 		 * responsibility to check how many bytes we were able to send.
2013 		 */
2014 
2015 		if (sk->sk_type == SOCK_SEQPACKET) {
2016 			written = transport->seqpacket_enqueue(vsk,
2017 						msg, len - total_written);
2018 		} else {
2019 			written = transport->stream_enqueue(vsk,
2020 					msg, len - total_written);
2021 		}
2022 
2023 		if (written < 0) {
2024 			err = written;
2025 			goto out_err;
2026 		}
2027 
2028 		total_written += written;
2029 
2030 		err = transport->notify_send_post_enqueue(
2031 				vsk, written, &send_data);
2032 		if (err < 0)
2033 			goto out_err;
2034 
2035 	}
2036 
2037 out_err:
2038 	if (total_written > 0) {
2039 		/* Return number of written bytes only if:
2040 		 * 1) SOCK_STREAM socket.
2041 		 * 2) SOCK_SEQPACKET socket when whole buffer is sent.
2042 		 */
2043 		if (sk->sk_type == SOCK_STREAM || total_written == len)
2044 			err = total_written;
2045 	}
2046 out:
2047 	if (sk->sk_type == SOCK_STREAM)
2048 		err = sk_stream_error(sk, msg->msg_flags, err);
2049 
2050 	release_sock(sk);
2051 	return err;
2052 }
2053 
2054 static int vsock_connectible_wait_data(struct sock *sk,
2055 				       struct wait_queue_entry *wait,
2056 				       long timeout,
2057 				       struct vsock_transport_recv_notify_data *recv_data,
2058 				       size_t target)
2059 {
2060 	const struct vsock_transport *transport;
2061 	struct vsock_sock *vsk;
2062 	s64 data;
2063 	int err;
2064 
2065 	vsk = vsock_sk(sk);
2066 	err = 0;
2067 	transport = vsk->transport;
2068 
2069 	while (1) {
2070 		prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
2071 		data = vsock_connectible_has_data(vsk);
2072 		if (data != 0)
2073 			break;
2074 
2075 		if (sk->sk_err != 0 ||
2076 		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
2077 		    (vsk->peer_shutdown & SEND_SHUTDOWN)) {
2078 			break;
2079 		}
2080 
2081 		/* Don't wait for non-blocking sockets. */
2082 		if (timeout == 0) {
2083 			err = -EAGAIN;
2084 			break;
2085 		}
2086 
2087 		if (recv_data) {
2088 			err = transport->notify_recv_pre_block(vsk, target, recv_data);
2089 			if (err < 0)
2090 				break;
2091 		}
2092 
2093 		release_sock(sk);
2094 		timeout = schedule_timeout(timeout);
2095 		lock_sock(sk);
2096 
2097 		if (signal_pending(current)) {
2098 			err = sock_intr_errno(timeout);
2099 			break;
2100 		} else if (timeout == 0) {
2101 			err = -EAGAIN;
2102 			break;
2103 		}
2104 	}
2105 
2106 	finish_wait(sk_sleep(sk), wait);
2107 
2108 	if (err)
2109 		return err;
2110 
2111 	/* Internal transport error when checking for available
2112 	 * data. XXX This should be changed to a connection
2113 	 * reset in a later change.
2114 	 */
2115 	if (data < 0)
2116 		return -ENOMEM;
2117 
2118 	return data;
2119 }
2120 
2121 static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
2122 				  size_t len, int flags)
2123 {
2124 	struct vsock_transport_recv_notify_data recv_data;
2125 	const struct vsock_transport *transport;
2126 	struct vsock_sock *vsk;
2127 	ssize_t copied;
2128 	size_t target;
2129 	long timeout;
2130 	int err;
2131 
2132 	DEFINE_WAIT(wait);
2133 
2134 	vsk = vsock_sk(sk);
2135 	transport = vsk->transport;
2136 
2137 	/* We must not copy less than target bytes into the user's buffer
2138 	 * before returning successfully, so we wait for the consume queue to
2139 	 * have that much data to consume before dequeueing.  Note that this
2140 	 * makes it impossible to handle cases where target is greater than the
2141 	 * queue size.
2142 	 */
2143 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2144 	if (target >= transport->stream_rcvhiwat(vsk)) {
2145 		err = -ENOMEM;
2146 		goto out;
2147 	}
2148 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2149 	copied = 0;
2150 
2151 	err = transport->notify_recv_init(vsk, target, &recv_data);
2152 	if (err < 0)
2153 		goto out;
2154 
2155 
2156 	while (1) {
2157 		ssize_t read;
2158 
2159 		err = vsock_connectible_wait_data(sk, &wait, timeout,
2160 						  &recv_data, target);
2161 		if (err <= 0)
2162 			break;
2163 
2164 		err = transport->notify_recv_pre_dequeue(vsk, target,
2165 							 &recv_data);
2166 		if (err < 0)
2167 			break;
2168 
2169 		read = transport->stream_dequeue(vsk, msg, len - copied, flags);
2170 		if (read < 0) {
2171 			err = read;
2172 			break;
2173 		}
2174 
2175 		copied += read;
2176 
2177 		err = transport->notify_recv_post_dequeue(vsk, target, read,
2178 						!(flags & MSG_PEEK), &recv_data);
2179 		if (err < 0)
2180 			goto out;
2181 
2182 		if (read >= target || flags & MSG_PEEK)
2183 			break;
2184 
2185 		target -= read;
2186 	}
2187 
2188 	if (sk->sk_err)
2189 		err = -sk->sk_err;
2190 	else if (sk->sk_shutdown & RCV_SHUTDOWN)
2191 		err = 0;
2192 
2193 	if (copied > 0)
2194 		err = copied;
2195 
2196 out:
2197 	return err;
2198 }
2199 
2200 static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
2201 				     size_t len, int flags)
2202 {
2203 	const struct vsock_transport *transport;
2204 	struct vsock_sock *vsk;
2205 	ssize_t msg_len;
2206 	long timeout;
2207 	int err = 0;
2208 	DEFINE_WAIT(wait);
2209 
2210 	vsk = vsock_sk(sk);
2211 	transport = vsk->transport;
2212 
2213 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2214 
2215 	err = vsock_connectible_wait_data(sk, &wait, timeout, NULL, 0);
2216 	if (err <= 0)
2217 		goto out;
2218 
2219 	msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
2220 
2221 	if (msg_len < 0) {
2222 		err = msg_len;
2223 		goto out;
2224 	}
2225 
2226 	if (sk->sk_err) {
2227 		err = -sk->sk_err;
2228 	} else if (sk->sk_shutdown & RCV_SHUTDOWN) {
2229 		err = 0;
2230 	} else {
2231 		/* User sets MSG_TRUNC, so return real length of
2232 		 * packet.
2233 		 */
2234 		if (flags & MSG_TRUNC)
2235 			err = msg_len;
2236 		else
2237 			err = len - msg_data_left(msg);
2238 
2239 		/* Always set MSG_TRUNC if real length of packet is
2240 		 * bigger than user's buffer.
2241 		 */
2242 		if (msg_len > len)
2243 			msg->msg_flags |= MSG_TRUNC;
2244 	}
2245 
2246 out:
2247 	return err;
2248 }
2249 
2250 int
2251 __vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2252 			    int flags)
2253 {
2254 	struct sock *sk;
2255 	struct vsock_sock *vsk;
2256 	const struct vsock_transport *transport;
2257 	int err;
2258 
2259 	sk = sock->sk;
2260 
2261 	if (unlikely(flags & MSG_ERRQUEUE))
2262 		return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, VSOCK_RECVERR);
2263 
2264 	vsk = vsock_sk(sk);
2265 	err = 0;
2266 
2267 	lock_sock(sk);
2268 
2269 	transport = vsk->transport;
2270 
2271 	if (!transport || sk->sk_state != TCP_ESTABLISHED) {
2272 		/* Recvmsg is supposed to return 0 if a peer performs an
2273 		 * orderly shutdown. Differentiate between that case and when a
2274 		 * peer has not connected or a local shutdown occurred with the
2275 		 * SOCK_DONE flag.
2276 		 */
2277 		if (sock_flag(sk, SOCK_DONE))
2278 			err = 0;
2279 		else
2280 			err = -ENOTCONN;
2281 
2282 		goto out;
2283 	}
2284 
2285 	if (flags & MSG_OOB) {
2286 		err = -EOPNOTSUPP;
2287 		goto out;
2288 	}
2289 
2290 	/* We don't check peer_shutdown flag here since peer may actually shut
2291 	 * down, but there can be data in the queue that a local socket can
2292 	 * receive.
2293 	 */
2294 	if (sk->sk_shutdown & RCV_SHUTDOWN) {
2295 		err = 0;
2296 		goto out;
2297 	}
2298 
2299 	/* It is valid on Linux to pass in a zero-length receive buffer.  This
2300 	 * is not an error.  We may as well bail out now.
2301 	 */
2302 	if (!len) {
2303 		err = 0;
2304 		goto out;
2305 	}
2306 
2307 	if (sk->sk_type == SOCK_STREAM)
2308 		err = __vsock_stream_recvmsg(sk, msg, len, flags);
2309 	else
2310 		err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);
2311 
2312 out:
2313 	release_sock(sk);
2314 	return err;
2315 }
2316 
2317 int
2318 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2319 			  int flags)
2320 {
2321 #ifdef CONFIG_BPF_SYSCALL
2322 	struct sock *sk = sock->sk;
2323 	const struct proto *prot;
2324 
2325 	prot = READ_ONCE(sk->sk_prot);
2326 	if (prot != &vsock_proto)
2327 		return prot->recvmsg(sk, msg, len, flags, NULL);
2328 #endif
2329 
2330 	return __vsock_connectible_recvmsg(sock, msg, len, flags);
2331 }
2332 EXPORT_SYMBOL_GPL(vsock_connectible_recvmsg);
2333 
2334 static int vsock_set_rcvlowat(struct sock *sk, int val)
2335 {
2336 	const struct vsock_transport *transport;
2337 	struct vsock_sock *vsk;
2338 
2339 	vsk = vsock_sk(sk);
2340 
2341 	if (val > vsk->buffer_size)
2342 		return -EINVAL;
2343 
2344 	transport = vsk->transport;
2345 
2346 	if (transport && transport->notify_set_rcvlowat) {
2347 		int err;
2348 
2349 		err = transport->notify_set_rcvlowat(vsk, val);
2350 		if (err)
2351 			return err;
2352 	}
2353 
2354 	WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
2355 	return 0;
2356 }
2357 
2358 static const struct proto_ops vsock_stream_ops = {
2359 	.family = PF_VSOCK,
2360 	.owner = THIS_MODULE,
2361 	.release = vsock_release,
2362 	.bind = vsock_bind,
2363 	.connect = vsock_connect,
2364 	.socketpair = sock_no_socketpair,
2365 	.accept = vsock_accept,
2366 	.getname = vsock_getname,
2367 	.poll = vsock_poll,
2368 	.ioctl = vsock_ioctl,
2369 	.listen = vsock_listen,
2370 	.shutdown = vsock_shutdown,
2371 	.setsockopt = vsock_connectible_setsockopt,
2372 	.getsockopt = vsock_connectible_getsockopt,
2373 	.sendmsg = vsock_connectible_sendmsg,
2374 	.recvmsg = vsock_connectible_recvmsg,
2375 	.mmap = sock_no_mmap,
2376 	.set_rcvlowat = vsock_set_rcvlowat,
2377 	.read_skb = vsock_read_skb,
2378 };
2379 
2380 static const struct proto_ops vsock_seqpacket_ops = {
2381 	.family = PF_VSOCK,
2382 	.owner = THIS_MODULE,
2383 	.release = vsock_release,
2384 	.bind = vsock_bind,
2385 	.connect = vsock_connect,
2386 	.socketpair = sock_no_socketpair,
2387 	.accept = vsock_accept,
2388 	.getname = vsock_getname,
2389 	.poll = vsock_poll,
2390 	.ioctl = vsock_ioctl,
2391 	.listen = vsock_listen,
2392 	.shutdown = vsock_shutdown,
2393 	.setsockopt = vsock_connectible_setsockopt,
2394 	.getsockopt = vsock_connectible_getsockopt,
2395 	.sendmsg = vsock_connectible_sendmsg,
2396 	.recvmsg = vsock_connectible_recvmsg,
2397 	.mmap = sock_no_mmap,
2398 	.read_skb = vsock_read_skb,
2399 };
2400 
2401 static int vsock_create(struct net *net, struct socket *sock,
2402 			int protocol, int kern)
2403 {
2404 	struct vsock_sock *vsk;
2405 	struct sock *sk;
2406 	int ret;
2407 
2408 	if (!sock)
2409 		return -EINVAL;
2410 
2411 	if (protocol && protocol != PF_VSOCK)
2412 		return -EPROTONOSUPPORT;
2413 
2414 	switch (sock->type) {
2415 	case SOCK_DGRAM:
2416 		sock->ops = &vsock_dgram_ops;
2417 		break;
2418 	case SOCK_STREAM:
2419 		sock->ops = &vsock_stream_ops;
2420 		break;
2421 	case SOCK_SEQPACKET:
2422 		sock->ops = &vsock_seqpacket_ops;
2423 		break;
2424 	default:
2425 		return -ESOCKTNOSUPPORT;
2426 	}
2427 
2428 	sock->state = SS_UNCONNECTED;
2429 
2430 	sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2431 	if (!sk)
2432 		return -ENOMEM;
2433 
2434 	vsk = vsock_sk(sk);
2435 
2436 	if (sock->type == SOCK_DGRAM) {
2437 		ret = vsock_assign_transport(vsk, NULL);
2438 		if (ret < 0) {
2439 			sock->sk = NULL;
2440 			sock_put(sk);
2441 			return ret;
2442 		}
2443 	}
2444 
2445 	/* SOCK_DGRAM doesn't have 'setsockopt' callback set in its
2446 	 * proto_ops, so there is no handler for custom logic.
2447 	 */
2448 	if (sock_type_connectible(sock->type))
2449 		set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
2450 
2451 	vsock_insert_unbound(vsk);
2452 
2453 	return 0;
2454 }
2455 
2456 static const struct net_proto_family vsock_family_ops = {
2457 	.family = AF_VSOCK,
2458 	.create = vsock_create,
2459 	.owner = THIS_MODULE,
2460 };
2461 
2462 static long vsock_dev_do_ioctl(struct file *filp,
2463 			       unsigned int cmd, void __user *ptr)
2464 {
2465 	u32 __user *p = ptr;
2466 	u32 cid = VMADDR_CID_ANY;
2467 	int retval = 0;
2468 
2469 	switch (cmd) {
2470 	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
2471 		/* To be compatible with the VMCI behavior, we prioritize the
2472 		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).
2473 		 */
2474 		if (transport_g2h)
2475 			cid = transport_g2h->get_local_cid();
2476 		else if (transport_h2g)
2477 			cid = transport_h2g->get_local_cid();
2478 
2479 		if (put_user(cid, p) != 0)
2480 			retval = -EFAULT;
2481 		break;
2482 
2483 	default:
2484 		retval = -ENOIOCTLCMD;
2485 	}
2486 
2487 	return retval;
2488 }
2489 
2490 static long vsock_dev_ioctl(struct file *filp,
2491 			    unsigned int cmd, unsigned long arg)
2492 {
2493 	return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
2494 }
2495 
2496 #ifdef CONFIG_COMPAT
2497 static long vsock_dev_compat_ioctl(struct file *filp,
2498 				   unsigned int cmd, unsigned long arg)
2499 {
2500 	return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
2501 }
2502 #endif
2503 
2504 static const struct file_operations vsock_device_ops = {
2505 	.owner		= THIS_MODULE,
2506 	.unlocked_ioctl	= vsock_dev_ioctl,
2507 #ifdef CONFIG_COMPAT
2508 	.compat_ioctl	= vsock_dev_compat_ioctl,
2509 #endif
2510 	.open		= nonseekable_open,
2511 };
2512 
2513 static struct miscdevice vsock_device = {
2514 	.name		= "vsock",
2515 	.fops		= &vsock_device_ops,
2516 };
2517 
2518 static int __init vsock_init(void)
2519 {
2520 	int err = 0;
2521 
2522 	vsock_init_tables();
2523 
2524 	vsock_proto.owner = THIS_MODULE;
2525 	vsock_device.minor = MISC_DYNAMIC_MINOR;
2526 	err = misc_register(&vsock_device);
2527 	if (err) {
2528 		pr_err("Failed to register misc device\n");
2529 		goto err_reset_transport;
2530 	}
2531 
2532 	err = proto_register(&vsock_proto, 1);	/* we want our slab */
2533 	if (err) {
2534 		pr_err("Cannot register vsock protocol\n");
2535 		goto err_deregister_misc;
2536 	}
2537 
2538 	err = sock_register(&vsock_family_ops);
2539 	if (err) {
2540 		pr_err("could not register af_vsock (%d) address family: %d\n",
2541 		       AF_VSOCK, err);
2542 		goto err_unregister_proto;
2543 	}
2544 
2545 	vsock_bpf_build_proto();
2546 
2547 	return 0;
2548 
2549 err_unregister_proto:
2550 	proto_unregister(&vsock_proto);
2551 err_deregister_misc:
2552 	misc_deregister(&vsock_device);
2553 err_reset_transport:
2554 	return err;
2555 }
2556 
2557 static void __exit vsock_exit(void)
2558 {
2559 	misc_deregister(&vsock_device);
2560 	sock_unregister(AF_VSOCK);
2561 	proto_unregister(&vsock_proto);
2562 }
2563 
2564 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
2565 {
2566 	return vsk->transport;
2567 }
2568 EXPORT_SYMBOL_GPL(vsock_core_get_transport);
2569 
2570 int vsock_core_register(const struct vsock_transport *t, int features)
2571 {
2572 	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
2573 	int err = mutex_lock_interruptible(&vsock_register_mutex);
2574 
2575 	if (err)
2576 		return err;
2577 
2578 	t_h2g = transport_h2g;
2579 	t_g2h = transport_g2h;
2580 	t_dgram = transport_dgram;
2581 	t_local = transport_local;
2582 
2583 	if (features & VSOCK_TRANSPORT_F_H2G) {
2584 		if (t_h2g) {
2585 			err = -EBUSY;
2586 			goto err_busy;
2587 		}
2588 		t_h2g = t;
2589 	}
2590 
2591 	if (features & VSOCK_TRANSPORT_F_G2H) {
2592 		if (t_g2h) {
2593 			err = -EBUSY;
2594 			goto err_busy;
2595 		}
2596 		t_g2h = t;
2597 	}
2598 
2599 	if (features & VSOCK_TRANSPORT_F_DGRAM) {
2600 		if (t_dgram) {
2601 			err = -EBUSY;
2602 			goto err_busy;
2603 		}
2604 		t_dgram = t;
2605 	}
2606 
2607 	if (features & VSOCK_TRANSPORT_F_LOCAL) {
2608 		if (t_local) {
2609 			err = -EBUSY;
2610 			goto err_busy;
2611 		}
2612 		t_local = t;
2613 	}
2614 
2615 	transport_h2g = t_h2g;
2616 	transport_g2h = t_g2h;
2617 	transport_dgram = t_dgram;
2618 	transport_local = t_local;
2619 
2620 err_busy:
2621 	mutex_unlock(&vsock_register_mutex);
2622 	return err;
2623 }
2624 EXPORT_SYMBOL_GPL(vsock_core_register);
2625 
2626 void vsock_core_unregister(const struct vsock_transport *t)
2627 {
2628 	mutex_lock(&vsock_register_mutex);
2629 
2630 	if (transport_h2g == t)
2631 		transport_h2g = NULL;
2632 
2633 	if (transport_g2h == t)
2634 		transport_g2h = NULL;
2635 
2636 	if (transport_dgram == t)
2637 		transport_dgram = NULL;
2638 
2639 	if (transport_local == t)
2640 		transport_local = NULL;
2641 
2642 	mutex_unlock(&vsock_register_mutex);
2643 }
2644 EXPORT_SYMBOL_GPL(vsock_core_unregister);
2645 
2646 module_init(vsock_init);
2647 module_exit(vsock_exit);
2648 
2649 MODULE_AUTHOR("VMware, Inc.");
2650 MODULE_DESCRIPTION("VMware Virtual Socket Family");
2651 MODULE_VERSION("1.0.2.0-k");
2652 MODULE_LICENSE("GPL v2");
2653