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 #include <linux/types.h>
9 #include <linux/bitops.h>
10 #include <linux/cred.h>
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/kmod.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/net.h>
19 #include <linux/poll.h>
20 #include <linux/skbuff.h>
21 #include <linux/smp.h>
22 #include <linux/socket.h>
23 #include <linux/stddef.h>
24 #include <linux/unistd.h>
25 #include <linux/wait.h>
26 #include <linux/workqueue.h>
27 #include <net/sock.h>
28 #include <net/af_vsock.h>
29 
30 #include "vmci_transport_notify.h"
31 
32 static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg);
33 static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg);
34 static void vmci_transport_peer_detach_cb(u32 sub_id,
35 					  const struct vmci_event_data *ed,
36 					  void *client_data);
37 static void vmci_transport_recv_pkt_work(struct work_struct *work);
38 static void vmci_transport_cleanup(struct work_struct *work);
39 static int vmci_transport_recv_listen(struct sock *sk,
40 				      struct vmci_transport_packet *pkt);
41 static int vmci_transport_recv_connecting_server(
42 					struct sock *sk,
43 					struct sock *pending,
44 					struct vmci_transport_packet *pkt);
45 static int vmci_transport_recv_connecting_client(
46 					struct sock *sk,
47 					struct vmci_transport_packet *pkt);
48 static int vmci_transport_recv_connecting_client_negotiate(
49 					struct sock *sk,
50 					struct vmci_transport_packet *pkt);
51 static int vmci_transport_recv_connecting_client_invalid(
52 					struct sock *sk,
53 					struct vmci_transport_packet *pkt);
54 static int vmci_transport_recv_connected(struct sock *sk,
55 					 struct vmci_transport_packet *pkt);
56 static bool vmci_transport_old_proto_override(bool *old_pkt_proto);
57 static u16 vmci_transport_new_proto_supported_versions(void);
58 static bool vmci_transport_proto_to_notify_struct(struct sock *sk, u16 *proto,
59 						  bool old_pkt_proto);
60 static bool vmci_check_transport(struct vsock_sock *vsk);
61 
62 struct vmci_transport_recv_pkt_info {
63 	struct work_struct work;
64 	struct sock *sk;
65 	struct vmci_transport_packet pkt;
66 };
67 
68 static LIST_HEAD(vmci_transport_cleanup_list);
69 static DEFINE_SPINLOCK(vmci_transport_cleanup_lock);
70 static DECLARE_WORK(vmci_transport_cleanup_work, vmci_transport_cleanup);
71 
72 static struct vmci_handle vmci_transport_stream_handle = { VMCI_INVALID_ID,
73 							   VMCI_INVALID_ID };
74 static u32 vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
75 
76 static int PROTOCOL_OVERRIDE = -1;
77 
78 static struct vsock_transport vmci_transport; /* forward declaration */
79 
80 /* Helper function to convert from a VMCI error code to a VSock error code. */
81 
82 static s32 vmci_transport_error_to_vsock_error(s32 vmci_error)
83 {
84 	switch (vmci_error) {
85 	case VMCI_ERROR_NO_MEM:
86 		return -ENOMEM;
87 	case VMCI_ERROR_DUPLICATE_ENTRY:
88 	case VMCI_ERROR_ALREADY_EXISTS:
89 		return -EADDRINUSE;
90 	case VMCI_ERROR_NO_ACCESS:
91 		return -EPERM;
92 	case VMCI_ERROR_NO_RESOURCES:
93 		return -ENOBUFS;
94 	case VMCI_ERROR_INVALID_RESOURCE:
95 		return -EHOSTUNREACH;
96 	case VMCI_ERROR_INVALID_ARGS:
97 	default:
98 		break;
99 	}
100 	return -EINVAL;
101 }
102 
103 static u32 vmci_transport_peer_rid(u32 peer_cid)
104 {
105 	if (VMADDR_CID_HYPERVISOR == peer_cid)
106 		return VMCI_TRANSPORT_HYPERVISOR_PACKET_RID;
107 
108 	return VMCI_TRANSPORT_PACKET_RID;
109 }
110 
111 static inline void
112 vmci_transport_packet_init(struct vmci_transport_packet *pkt,
113 			   struct sockaddr_vm *src,
114 			   struct sockaddr_vm *dst,
115 			   u8 type,
116 			   u64 size,
117 			   u64 mode,
118 			   struct vmci_transport_waiting_info *wait,
119 			   u16 proto,
120 			   struct vmci_handle handle)
121 {
122 	/* We register the stream control handler as an any cid handle so we
123 	 * must always send from a source address of VMADDR_CID_ANY
124 	 */
125 	pkt->dg.src = vmci_make_handle(VMADDR_CID_ANY,
126 				       VMCI_TRANSPORT_PACKET_RID);
127 	pkt->dg.dst = vmci_make_handle(dst->svm_cid,
128 				       vmci_transport_peer_rid(dst->svm_cid));
129 	pkt->dg.payload_size = sizeof(*pkt) - sizeof(pkt->dg);
130 	pkt->version = VMCI_TRANSPORT_PACKET_VERSION;
131 	pkt->type = type;
132 	pkt->src_port = src->svm_port;
133 	pkt->dst_port = dst->svm_port;
134 	memset(&pkt->proto, 0, sizeof(pkt->proto));
135 	memset(&pkt->_reserved2, 0, sizeof(pkt->_reserved2));
136 
137 	switch (pkt->type) {
138 	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
139 		pkt->u.size = 0;
140 		break;
141 
142 	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST:
143 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
144 		pkt->u.size = size;
145 		break;
146 
147 	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
148 	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
149 		pkt->u.handle = handle;
150 		break;
151 
152 	case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
153 	case VMCI_TRANSPORT_PACKET_TYPE_READ:
154 	case VMCI_TRANSPORT_PACKET_TYPE_RST:
155 		pkt->u.size = 0;
156 		break;
157 
158 	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
159 		pkt->u.mode = mode;
160 		break;
161 
162 	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
163 	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
164 		memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
165 		break;
166 
167 	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2:
168 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
169 		pkt->u.size = size;
170 		pkt->proto = proto;
171 		break;
172 	}
173 }
174 
175 static inline void
176 vmci_transport_packet_get_addresses(struct vmci_transport_packet *pkt,
177 				    struct sockaddr_vm *local,
178 				    struct sockaddr_vm *remote)
179 {
180 	vsock_addr_init(local, pkt->dg.dst.context, pkt->dst_port);
181 	vsock_addr_init(remote, pkt->dg.src.context, pkt->src_port);
182 }
183 
184 static int
185 __vmci_transport_send_control_pkt(struct vmci_transport_packet *pkt,
186 				  struct sockaddr_vm *src,
187 				  struct sockaddr_vm *dst,
188 				  enum vmci_transport_packet_type type,
189 				  u64 size,
190 				  u64 mode,
191 				  struct vmci_transport_waiting_info *wait,
192 				  u16 proto,
193 				  struct vmci_handle handle,
194 				  bool convert_error)
195 {
196 	int err;
197 
198 	vmci_transport_packet_init(pkt, src, dst, type, size, mode, wait,
199 				   proto, handle);
200 	err = vmci_datagram_send(&pkt->dg);
201 	if (convert_error && (err < 0))
202 		return vmci_transport_error_to_vsock_error(err);
203 
204 	return err;
205 }
206 
207 static int
208 vmci_transport_reply_control_pkt_fast(struct vmci_transport_packet *pkt,
209 				      enum vmci_transport_packet_type type,
210 				      u64 size,
211 				      u64 mode,
212 				      struct vmci_transport_waiting_info *wait,
213 				      struct vmci_handle handle)
214 {
215 	struct vmci_transport_packet reply;
216 	struct sockaddr_vm src, dst;
217 
218 	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST) {
219 		return 0;
220 	} else {
221 		vmci_transport_packet_get_addresses(pkt, &src, &dst);
222 		return __vmci_transport_send_control_pkt(&reply, &src, &dst,
223 							 type,
224 							 size, mode, wait,
225 							 VSOCK_PROTO_INVALID,
226 							 handle, true);
227 	}
228 }
229 
230 static int
231 vmci_transport_send_control_pkt_bh(struct sockaddr_vm *src,
232 				   struct sockaddr_vm *dst,
233 				   enum vmci_transport_packet_type type,
234 				   u64 size,
235 				   u64 mode,
236 				   struct vmci_transport_waiting_info *wait,
237 				   struct vmci_handle handle)
238 {
239 	/* Note that it is safe to use a single packet across all CPUs since
240 	 * two tasklets of the same type are guaranteed to not ever run
241 	 * simultaneously. If that ever changes, or VMCI stops using tasklets,
242 	 * we can use per-cpu packets.
243 	 */
244 	static struct vmci_transport_packet pkt;
245 
246 	return __vmci_transport_send_control_pkt(&pkt, src, dst, type,
247 						 size, mode, wait,
248 						 VSOCK_PROTO_INVALID, handle,
249 						 false);
250 }
251 
252 static int
253 vmci_transport_alloc_send_control_pkt(struct sockaddr_vm *src,
254 				      struct sockaddr_vm *dst,
255 				      enum vmci_transport_packet_type type,
256 				      u64 size,
257 				      u64 mode,
258 				      struct vmci_transport_waiting_info *wait,
259 				      u16 proto,
260 				      struct vmci_handle handle)
261 {
262 	struct vmci_transport_packet *pkt;
263 	int err;
264 
265 	pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
266 	if (!pkt)
267 		return -ENOMEM;
268 
269 	err = __vmci_transport_send_control_pkt(pkt, src, dst, type, size,
270 						mode, wait, proto, handle,
271 						true);
272 	kfree(pkt);
273 
274 	return err;
275 }
276 
277 static int
278 vmci_transport_send_control_pkt(struct sock *sk,
279 				enum vmci_transport_packet_type type,
280 				u64 size,
281 				u64 mode,
282 				struct vmci_transport_waiting_info *wait,
283 				u16 proto,
284 				struct vmci_handle handle)
285 {
286 	struct vsock_sock *vsk;
287 
288 	vsk = vsock_sk(sk);
289 
290 	if (!vsock_addr_bound(&vsk->local_addr))
291 		return -EINVAL;
292 
293 	if (!vsock_addr_bound(&vsk->remote_addr))
294 		return -EINVAL;
295 
296 	return vmci_transport_alloc_send_control_pkt(&vsk->local_addr,
297 						     &vsk->remote_addr,
298 						     type, size, mode,
299 						     wait, proto, handle);
300 }
301 
302 static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
303 					struct sockaddr_vm *src,
304 					struct vmci_transport_packet *pkt)
305 {
306 	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
307 		return 0;
308 	return vmci_transport_send_control_pkt_bh(
309 					dst, src,
310 					VMCI_TRANSPORT_PACKET_TYPE_RST, 0,
311 					0, NULL, VMCI_INVALID_HANDLE);
312 }
313 
314 static int vmci_transport_send_reset(struct sock *sk,
315 				     struct vmci_transport_packet *pkt)
316 {
317 	struct sockaddr_vm *dst_ptr;
318 	struct sockaddr_vm dst;
319 	struct vsock_sock *vsk;
320 
321 	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
322 		return 0;
323 
324 	vsk = vsock_sk(sk);
325 
326 	if (!vsock_addr_bound(&vsk->local_addr))
327 		return -EINVAL;
328 
329 	if (vsock_addr_bound(&vsk->remote_addr)) {
330 		dst_ptr = &vsk->remote_addr;
331 	} else {
332 		vsock_addr_init(&dst, pkt->dg.src.context,
333 				pkt->src_port);
334 		dst_ptr = &dst;
335 	}
336 	return vmci_transport_alloc_send_control_pkt(&vsk->local_addr, dst_ptr,
337 					     VMCI_TRANSPORT_PACKET_TYPE_RST,
338 					     0, 0, NULL, VSOCK_PROTO_INVALID,
339 					     VMCI_INVALID_HANDLE);
340 }
341 
342 static int vmci_transport_send_negotiate(struct sock *sk, size_t size)
343 {
344 	return vmci_transport_send_control_pkt(
345 					sk,
346 					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE,
347 					size, 0, NULL,
348 					VSOCK_PROTO_INVALID,
349 					VMCI_INVALID_HANDLE);
350 }
351 
352 static int vmci_transport_send_negotiate2(struct sock *sk, size_t size,
353 					  u16 version)
354 {
355 	return vmci_transport_send_control_pkt(
356 					sk,
357 					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2,
358 					size, 0, NULL, version,
359 					VMCI_INVALID_HANDLE);
360 }
361 
362 static int vmci_transport_send_qp_offer(struct sock *sk,
363 					struct vmci_handle handle)
364 {
365 	return vmci_transport_send_control_pkt(
366 					sk, VMCI_TRANSPORT_PACKET_TYPE_OFFER, 0,
367 					0, NULL,
368 					VSOCK_PROTO_INVALID, handle);
369 }
370 
371 static int vmci_transport_send_attach(struct sock *sk,
372 				      struct vmci_handle handle)
373 {
374 	return vmci_transport_send_control_pkt(
375 					sk, VMCI_TRANSPORT_PACKET_TYPE_ATTACH,
376 					0, 0, NULL, VSOCK_PROTO_INVALID,
377 					handle);
378 }
379 
380 static int vmci_transport_reply_reset(struct vmci_transport_packet *pkt)
381 {
382 	return vmci_transport_reply_control_pkt_fast(
383 						pkt,
384 						VMCI_TRANSPORT_PACKET_TYPE_RST,
385 						0, 0, NULL,
386 						VMCI_INVALID_HANDLE);
387 }
388 
389 static int vmci_transport_send_invalid_bh(struct sockaddr_vm *dst,
390 					  struct sockaddr_vm *src)
391 {
392 	return vmci_transport_send_control_pkt_bh(
393 					dst, src,
394 					VMCI_TRANSPORT_PACKET_TYPE_INVALID,
395 					0, 0, NULL, VMCI_INVALID_HANDLE);
396 }
397 
398 int vmci_transport_send_wrote_bh(struct sockaddr_vm *dst,
399 				 struct sockaddr_vm *src)
400 {
401 	return vmci_transport_send_control_pkt_bh(
402 					dst, src,
403 					VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
404 					0, NULL, VMCI_INVALID_HANDLE);
405 }
406 
407 int vmci_transport_send_read_bh(struct sockaddr_vm *dst,
408 				struct sockaddr_vm *src)
409 {
410 	return vmci_transport_send_control_pkt_bh(
411 					dst, src,
412 					VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
413 					0, NULL, VMCI_INVALID_HANDLE);
414 }
415 
416 int vmci_transport_send_wrote(struct sock *sk)
417 {
418 	return vmci_transport_send_control_pkt(
419 					sk, VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
420 					0, NULL, VSOCK_PROTO_INVALID,
421 					VMCI_INVALID_HANDLE);
422 }
423 
424 int vmci_transport_send_read(struct sock *sk)
425 {
426 	return vmci_transport_send_control_pkt(
427 					sk, VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
428 					0, NULL, VSOCK_PROTO_INVALID,
429 					VMCI_INVALID_HANDLE);
430 }
431 
432 int vmci_transport_send_waiting_write(struct sock *sk,
433 				      struct vmci_transport_waiting_info *wait)
434 {
435 	return vmci_transport_send_control_pkt(
436 				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE,
437 				0, 0, wait, VSOCK_PROTO_INVALID,
438 				VMCI_INVALID_HANDLE);
439 }
440 
441 int vmci_transport_send_waiting_read(struct sock *sk,
442 				     struct vmci_transport_waiting_info *wait)
443 {
444 	return vmci_transport_send_control_pkt(
445 				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ,
446 				0, 0, wait, VSOCK_PROTO_INVALID,
447 				VMCI_INVALID_HANDLE);
448 }
449 
450 static int vmci_transport_shutdown(struct vsock_sock *vsk, int mode)
451 {
452 	return vmci_transport_send_control_pkt(
453 					&vsk->sk,
454 					VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN,
455 					0, mode, NULL,
456 					VSOCK_PROTO_INVALID,
457 					VMCI_INVALID_HANDLE);
458 }
459 
460 static int vmci_transport_send_conn_request(struct sock *sk, size_t size)
461 {
462 	return vmci_transport_send_control_pkt(sk,
463 					VMCI_TRANSPORT_PACKET_TYPE_REQUEST,
464 					size, 0, NULL,
465 					VSOCK_PROTO_INVALID,
466 					VMCI_INVALID_HANDLE);
467 }
468 
469 static int vmci_transport_send_conn_request2(struct sock *sk, size_t size,
470 					     u16 version)
471 {
472 	return vmci_transport_send_control_pkt(
473 					sk, VMCI_TRANSPORT_PACKET_TYPE_REQUEST2,
474 					size, 0, NULL, version,
475 					VMCI_INVALID_HANDLE);
476 }
477 
478 static struct sock *vmci_transport_get_pending(
479 					struct sock *listener,
480 					struct vmci_transport_packet *pkt)
481 {
482 	struct vsock_sock *vlistener;
483 	struct vsock_sock *vpending;
484 	struct sock *pending;
485 	struct sockaddr_vm src;
486 
487 	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
488 
489 	vlistener = vsock_sk(listener);
490 
491 	list_for_each_entry(vpending, &vlistener->pending_links,
492 			    pending_links) {
493 		if (vsock_addr_equals_addr(&src, &vpending->remote_addr) &&
494 		    pkt->dst_port == vpending->local_addr.svm_port) {
495 			pending = sk_vsock(vpending);
496 			sock_hold(pending);
497 			goto found;
498 		}
499 	}
500 
501 	pending = NULL;
502 found:
503 	return pending;
504 
505 }
506 
507 static void vmci_transport_release_pending(struct sock *pending)
508 {
509 	sock_put(pending);
510 }
511 
512 /* We allow two kinds of sockets to communicate with a restricted VM: 1)
513  * trusted sockets 2) sockets from applications running as the same user as the
514  * VM (this is only true for the host side and only when using hosted products)
515  */
516 
517 static bool vmci_transport_is_trusted(struct vsock_sock *vsock, u32 peer_cid)
518 {
519 	return vsock->trusted ||
520 	       vmci_is_context_owner(peer_cid, vsock->owner->uid);
521 }
522 
523 /* We allow sending datagrams to and receiving datagrams from a restricted VM
524  * only if it is trusted as described in vmci_transport_is_trusted.
525  */
526 
527 static bool vmci_transport_allow_dgram(struct vsock_sock *vsock, u32 peer_cid)
528 {
529 	if (VMADDR_CID_HYPERVISOR == peer_cid)
530 		return true;
531 
532 	if (vsock->cached_peer != peer_cid) {
533 		vsock->cached_peer = peer_cid;
534 		if (!vmci_transport_is_trusted(vsock, peer_cid) &&
535 		    (vmci_context_get_priv_flags(peer_cid) &
536 		     VMCI_PRIVILEGE_FLAG_RESTRICTED)) {
537 			vsock->cached_peer_allow_dgram = false;
538 		} else {
539 			vsock->cached_peer_allow_dgram = true;
540 		}
541 	}
542 
543 	return vsock->cached_peer_allow_dgram;
544 }
545 
546 static int
547 vmci_transport_queue_pair_alloc(struct vmci_qp **qpair,
548 				struct vmci_handle *handle,
549 				u64 produce_size,
550 				u64 consume_size,
551 				u32 peer, u32 flags, bool trusted)
552 {
553 	int err = 0;
554 
555 	if (trusted) {
556 		/* Try to allocate our queue pair as trusted. This will only
557 		 * work if vsock is running in the host.
558 		 */
559 
560 		err = vmci_qpair_alloc(qpair, handle, produce_size,
561 				       consume_size,
562 				       peer, flags,
563 				       VMCI_PRIVILEGE_FLAG_TRUSTED);
564 		if (err != VMCI_ERROR_NO_ACCESS)
565 			goto out;
566 
567 	}
568 
569 	err = vmci_qpair_alloc(qpair, handle, produce_size, consume_size,
570 			       peer, flags, VMCI_NO_PRIVILEGE_FLAGS);
571 out:
572 	if (err < 0) {
573 		pr_err_once("Could not attach to queue pair with %d\n", err);
574 		err = vmci_transport_error_to_vsock_error(err);
575 	}
576 
577 	return err;
578 }
579 
580 static int
581 vmci_transport_datagram_create_hnd(u32 resource_id,
582 				   u32 flags,
583 				   vmci_datagram_recv_cb recv_cb,
584 				   void *client_data,
585 				   struct vmci_handle *out_handle)
586 {
587 	int err = 0;
588 
589 	/* Try to allocate our datagram handler as trusted. This will only work
590 	 * if vsock is running in the host.
591 	 */
592 
593 	err = vmci_datagram_create_handle_priv(resource_id, flags,
594 					       VMCI_PRIVILEGE_FLAG_TRUSTED,
595 					       recv_cb,
596 					       client_data, out_handle);
597 
598 	if (err == VMCI_ERROR_NO_ACCESS)
599 		err = vmci_datagram_create_handle(resource_id, flags,
600 						  recv_cb, client_data,
601 						  out_handle);
602 
603 	return err;
604 }
605 
606 /* This is invoked as part of a tasklet that's scheduled when the VMCI
607  * interrupt fires.  This is run in bottom-half context and if it ever needs to
608  * sleep it should defer that work to a work queue.
609  */
610 
611 static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
612 {
613 	struct sock *sk;
614 	size_t size;
615 	struct sk_buff *skb;
616 	struct vsock_sock *vsk;
617 
618 	sk = (struct sock *)data;
619 
620 	/* This handler is privileged when this module is running on the host.
621 	 * We will get datagrams from all endpoints (even VMs that are in a
622 	 * restricted context). If we get one from a restricted context then
623 	 * the destination socket must be trusted.
624 	 *
625 	 * NOTE: We access the socket struct without holding the lock here.
626 	 * This is ok because the field we are interested is never modified
627 	 * outside of the create and destruct socket functions.
628 	 */
629 	vsk = vsock_sk(sk);
630 	if (!vmci_transport_allow_dgram(vsk, dg->src.context))
631 		return VMCI_ERROR_NO_ACCESS;
632 
633 	size = VMCI_DG_SIZE(dg);
634 
635 	/* Attach the packet to the socket's receive queue as an sk_buff. */
636 	skb = alloc_skb(size, GFP_ATOMIC);
637 	if (!skb)
638 		return VMCI_ERROR_NO_MEM;
639 
640 	/* sk_receive_skb() will do a sock_put(), so hold here. */
641 	sock_hold(sk);
642 	skb_put(skb, size);
643 	memcpy(skb->data, dg, size);
644 	sk_receive_skb(sk, skb, 0);
645 
646 	return VMCI_SUCCESS;
647 }
648 
649 static bool vmci_transport_stream_allow(u32 cid, u32 port)
650 {
651 	static const u32 non_socket_contexts[] = {
652 		VMADDR_CID_LOCAL,
653 	};
654 	int i;
655 
656 	BUILD_BUG_ON(sizeof(cid) != sizeof(*non_socket_contexts));
657 
658 	for (i = 0; i < ARRAY_SIZE(non_socket_contexts); i++) {
659 		if (cid == non_socket_contexts[i])
660 			return false;
661 	}
662 
663 	return true;
664 }
665 
666 /* This is invoked as part of a tasklet that's scheduled when the VMCI
667  * interrupt fires.  This is run in bottom-half context but it defers most of
668  * its work to the packet handling work queue.
669  */
670 
671 static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
672 {
673 	struct sock *sk;
674 	struct sockaddr_vm dst;
675 	struct sockaddr_vm src;
676 	struct vmci_transport_packet *pkt;
677 	struct vsock_sock *vsk;
678 	bool bh_process_pkt;
679 	int err;
680 
681 	sk = NULL;
682 	err = VMCI_SUCCESS;
683 	bh_process_pkt = false;
684 
685 	/* Ignore incoming packets from contexts without sockets, or resources
686 	 * that aren't vsock implementations.
687 	 */
688 
689 	if (!vmci_transport_stream_allow(dg->src.context, -1)
690 	    || vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
691 		return VMCI_ERROR_NO_ACCESS;
692 
693 	if (VMCI_DG_SIZE(dg) < sizeof(*pkt))
694 		/* Drop datagrams that do not contain full VSock packets. */
695 		return VMCI_ERROR_INVALID_ARGS;
696 
697 	pkt = (struct vmci_transport_packet *)dg;
698 
699 	/* Find the socket that should handle this packet.  First we look for a
700 	 * connected socket and if there is none we look for a socket bound to
701 	 * the destintation address.
702 	 */
703 	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
704 	vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);
705 
706 	sk = vsock_find_connected_socket(&src, &dst);
707 	if (!sk) {
708 		sk = vsock_find_bound_socket(&dst);
709 		if (!sk) {
710 			/* We could not find a socket for this specified
711 			 * address.  If this packet is a RST, we just drop it.
712 			 * If it is another packet, we send a RST.  Note that
713 			 * we do not send a RST reply to RSTs so that we do not
714 			 * continually send RSTs between two endpoints.
715 			 *
716 			 * Note that since this is a reply, dst is src and src
717 			 * is dst.
718 			 */
719 			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
720 				pr_err("unable to send reset\n");
721 
722 			err = VMCI_ERROR_NOT_FOUND;
723 			goto out;
724 		}
725 	}
726 
727 	/* If the received packet type is beyond all types known to this
728 	 * implementation, reply with an invalid message.  Hopefully this will
729 	 * help when implementing backwards compatibility in the future.
730 	 */
731 	if (pkt->type >= VMCI_TRANSPORT_PACKET_TYPE_MAX) {
732 		vmci_transport_send_invalid_bh(&dst, &src);
733 		err = VMCI_ERROR_INVALID_ARGS;
734 		goto out;
735 	}
736 
737 	/* This handler is privileged when this module is running on the host.
738 	 * We will get datagram connect requests from all endpoints (even VMs
739 	 * that are in a restricted context). If we get one from a restricted
740 	 * context then the destination socket must be trusted.
741 	 *
742 	 * NOTE: We access the socket struct without holding the lock here.
743 	 * This is ok because the field we are interested is never modified
744 	 * outside of the create and destruct socket functions.
745 	 */
746 	vsk = vsock_sk(sk);
747 	if (!vmci_transport_allow_dgram(vsk, pkt->dg.src.context)) {
748 		err = VMCI_ERROR_NO_ACCESS;
749 		goto out;
750 	}
751 
752 	/* We do most everything in a work queue, but let's fast path the
753 	 * notification of reads and writes to help data transfer performance.
754 	 * We can only do this if there is no process context code executing
755 	 * for this socket since that may change the state.
756 	 */
757 	bh_lock_sock(sk);
758 
759 	if (!sock_owned_by_user(sk)) {
760 		/* The local context ID may be out of date, update it. */
761 		vsk->local_addr.svm_cid = dst.svm_cid;
762 
763 		if (sk->sk_state == TCP_ESTABLISHED)
764 			vmci_trans(vsk)->notify_ops->handle_notify_pkt(
765 					sk, pkt, true, &dst, &src,
766 					&bh_process_pkt);
767 	}
768 
769 	bh_unlock_sock(sk);
770 
771 	if (!bh_process_pkt) {
772 		struct vmci_transport_recv_pkt_info *recv_pkt_info;
773 
774 		recv_pkt_info = kmalloc(sizeof(*recv_pkt_info), GFP_ATOMIC);
775 		if (!recv_pkt_info) {
776 			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
777 				pr_err("unable to send reset\n");
778 
779 			err = VMCI_ERROR_NO_MEM;
780 			goto out;
781 		}
782 
783 		recv_pkt_info->sk = sk;
784 		memcpy(&recv_pkt_info->pkt, pkt, sizeof(recv_pkt_info->pkt));
785 		INIT_WORK(&recv_pkt_info->work, vmci_transport_recv_pkt_work);
786 
787 		schedule_work(&recv_pkt_info->work);
788 		/* Clear sk so that the reference count incremented by one of
789 		 * the Find functions above is not decremented below.  We need
790 		 * that reference count for the packet handler we've scheduled
791 		 * to run.
792 		 */
793 		sk = NULL;
794 	}
795 
796 out:
797 	if (sk)
798 		sock_put(sk);
799 
800 	return err;
801 }
802 
803 static void vmci_transport_handle_detach(struct sock *sk)
804 {
805 	struct vsock_sock *vsk;
806 
807 	vsk = vsock_sk(sk);
808 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
809 		sock_set_flag(sk, SOCK_DONE);
810 
811 		/* On a detach the peer will not be sending or receiving
812 		 * anymore.
813 		 */
814 		vsk->peer_shutdown = SHUTDOWN_MASK;
815 
816 		/* We should not be sending anymore since the peer won't be
817 		 * there to receive, but we can still receive if there is data
818 		 * left in our consume queue. If the local endpoint is a host,
819 		 * we can't call vsock_stream_has_data, since that may block,
820 		 * but a host endpoint can't read data once the VM has
821 		 * detached, so there is no available data in that case.
822 		 */
823 		if (vsk->local_addr.svm_cid == VMADDR_CID_HOST ||
824 		    vsock_stream_has_data(vsk) <= 0) {
825 			if (sk->sk_state == TCP_SYN_SENT) {
826 				/* The peer may detach from a queue pair while
827 				 * we are still in the connecting state, i.e.,
828 				 * if the peer VM is killed after attaching to
829 				 * a queue pair, but before we complete the
830 				 * handshake. In that case, we treat the detach
831 				 * event like a reset.
832 				 */
833 
834 				sk->sk_state = TCP_CLOSE;
835 				sk->sk_err = ECONNRESET;
836 				sk_error_report(sk);
837 				return;
838 			}
839 			sk->sk_state = TCP_CLOSE;
840 		}
841 		sk->sk_state_change(sk);
842 	}
843 }
844 
845 static void vmci_transport_peer_detach_cb(u32 sub_id,
846 					  const struct vmci_event_data *e_data,
847 					  void *client_data)
848 {
849 	struct vmci_transport *trans = client_data;
850 	const struct vmci_event_payload_qp *e_payload;
851 
852 	e_payload = vmci_event_data_const_payload(e_data);
853 
854 	/* XXX This is lame, we should provide a way to lookup sockets by
855 	 * qp_handle.
856 	 */
857 	if (vmci_handle_is_invalid(e_payload->handle) ||
858 	    !vmci_handle_is_equal(trans->qp_handle, e_payload->handle))
859 		return;
860 
861 	/* We don't ask for delayed CBs when we subscribe to this event (we
862 	 * pass 0 as flags to vmci_event_subscribe()).  VMCI makes no
863 	 * guarantees in that case about what context we might be running in,
864 	 * so it could be BH or process, blockable or non-blockable.  So we
865 	 * need to account for all possible contexts here.
866 	 */
867 	spin_lock_bh(&trans->lock);
868 	if (!trans->sk)
869 		goto out;
870 
871 	/* Apart from here, trans->lock is only grabbed as part of sk destruct,
872 	 * where trans->sk isn't locked.
873 	 */
874 	bh_lock_sock(trans->sk);
875 
876 	vmci_transport_handle_detach(trans->sk);
877 
878 	bh_unlock_sock(trans->sk);
879  out:
880 	spin_unlock_bh(&trans->lock);
881 }
882 
883 static void vmci_transport_qp_resumed_cb(u32 sub_id,
884 					 const struct vmci_event_data *e_data,
885 					 void *client_data)
886 {
887 	vsock_for_each_connected_socket(&vmci_transport,
888 					vmci_transport_handle_detach);
889 }
890 
891 static void vmci_transport_recv_pkt_work(struct work_struct *work)
892 {
893 	struct vmci_transport_recv_pkt_info *recv_pkt_info;
894 	struct vmci_transport_packet *pkt;
895 	struct sock *sk;
896 
897 	recv_pkt_info =
898 		container_of(work, struct vmci_transport_recv_pkt_info, work);
899 	sk = recv_pkt_info->sk;
900 	pkt = &recv_pkt_info->pkt;
901 
902 	lock_sock(sk);
903 
904 	/* The local context ID may be out of date. */
905 	vsock_sk(sk)->local_addr.svm_cid = pkt->dg.dst.context;
906 
907 	switch (sk->sk_state) {
908 	case TCP_LISTEN:
909 		vmci_transport_recv_listen(sk, pkt);
910 		break;
911 	case TCP_SYN_SENT:
912 		/* Processing of pending connections for servers goes through
913 		 * the listening socket, so see vmci_transport_recv_listen()
914 		 * for that path.
915 		 */
916 		vmci_transport_recv_connecting_client(sk, pkt);
917 		break;
918 	case TCP_ESTABLISHED:
919 		vmci_transport_recv_connected(sk, pkt);
920 		break;
921 	default:
922 		/* Because this function does not run in the same context as
923 		 * vmci_transport_recv_stream_cb it is possible that the
924 		 * socket has closed. We need to let the other side know or it
925 		 * could be sitting in a connect and hang forever. Send a
926 		 * reset to prevent that.
927 		 */
928 		vmci_transport_send_reset(sk, pkt);
929 		break;
930 	}
931 
932 	release_sock(sk);
933 	kfree(recv_pkt_info);
934 	/* Release reference obtained in the stream callback when we fetched
935 	 * this socket out of the bound or connected list.
936 	 */
937 	sock_put(sk);
938 }
939 
940 static int vmci_transport_recv_listen(struct sock *sk,
941 				      struct vmci_transport_packet *pkt)
942 {
943 	struct sock *pending;
944 	struct vsock_sock *vpending;
945 	int err;
946 	u64 qp_size;
947 	bool old_request = false;
948 	bool old_pkt_proto = false;
949 
950 	/* Because we are in the listen state, we could be receiving a packet
951 	 * for ourself or any previous connection requests that we received.
952 	 * If it's the latter, we try to find a socket in our list of pending
953 	 * connections and, if we do, call the appropriate handler for the
954 	 * state that socket is in.  Otherwise we try to service the
955 	 * connection request.
956 	 */
957 	pending = vmci_transport_get_pending(sk, pkt);
958 	if (pending) {
959 		lock_sock(pending);
960 
961 		/* The local context ID may be out of date. */
962 		vsock_sk(pending)->local_addr.svm_cid = pkt->dg.dst.context;
963 
964 		switch (pending->sk_state) {
965 		case TCP_SYN_SENT:
966 			err = vmci_transport_recv_connecting_server(sk,
967 								    pending,
968 								    pkt);
969 			break;
970 		default:
971 			vmci_transport_send_reset(pending, pkt);
972 			err = -EINVAL;
973 		}
974 
975 		if (err < 0)
976 			vsock_remove_pending(sk, pending);
977 
978 		release_sock(pending);
979 		vmci_transport_release_pending(pending);
980 
981 		return err;
982 	}
983 
984 	/* The listen state only accepts connection requests.  Reply with a
985 	 * reset unless we received a reset.
986 	 */
987 
988 	if (!(pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST ||
989 	      pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)) {
990 		vmci_transport_reply_reset(pkt);
991 		return -EINVAL;
992 	}
993 
994 	if (pkt->u.size == 0) {
995 		vmci_transport_reply_reset(pkt);
996 		return -EINVAL;
997 	}
998 
999 	/* If this socket can't accommodate this connection request, we send a
1000 	 * reset.  Otherwise we create and initialize a child socket and reply
1001 	 * with a connection negotiation.
1002 	 */
1003 	if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) {
1004 		vmci_transport_reply_reset(pkt);
1005 		return -ECONNREFUSED;
1006 	}
1007 
1008 	pending = vsock_create_connected(sk);
1009 	if (!pending) {
1010 		vmci_transport_send_reset(sk, pkt);
1011 		return -ENOMEM;
1012 	}
1013 
1014 	vpending = vsock_sk(pending);
1015 
1016 	vsock_addr_init(&vpending->local_addr, pkt->dg.dst.context,
1017 			pkt->dst_port);
1018 	vsock_addr_init(&vpending->remote_addr, pkt->dg.src.context,
1019 			pkt->src_port);
1020 
1021 	err = vsock_assign_transport(vpending, vsock_sk(sk));
1022 	/* Transport assigned (looking at remote_addr) must be the same
1023 	 * where we received the request.
1024 	 */
1025 	if (err || !vmci_check_transport(vpending)) {
1026 		vmci_transport_send_reset(sk, pkt);
1027 		sock_put(pending);
1028 		return err;
1029 	}
1030 
1031 	/* If the proposed size fits within our min/max, accept it. Otherwise
1032 	 * propose our own size.
1033 	 */
1034 	if (pkt->u.size >= vpending->buffer_min_size &&
1035 	    pkt->u.size <= vpending->buffer_max_size) {
1036 		qp_size = pkt->u.size;
1037 	} else {
1038 		qp_size = vpending->buffer_size;
1039 	}
1040 
1041 	/* Figure out if we are using old or new requests based on the
1042 	 * overrides pkt types sent by our peer.
1043 	 */
1044 	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
1045 		old_request = old_pkt_proto;
1046 	} else {
1047 		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST)
1048 			old_request = true;
1049 		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)
1050 			old_request = false;
1051 
1052 	}
1053 
1054 	if (old_request) {
1055 		/* Handle a REQUEST (or override) */
1056 		u16 version = VSOCK_PROTO_INVALID;
1057 		if (vmci_transport_proto_to_notify_struct(
1058 			pending, &version, true))
1059 			err = vmci_transport_send_negotiate(pending, qp_size);
1060 		else
1061 			err = -EINVAL;
1062 
1063 	} else {
1064 		/* Handle a REQUEST2 (or override) */
1065 		int proto_int = pkt->proto;
1066 		int pos;
1067 		u16 active_proto_version = 0;
1068 
1069 		/* The list of possible protocols is the intersection of all
1070 		 * protocols the client supports ... plus all the protocols we
1071 		 * support.
1072 		 */
1073 		proto_int &= vmci_transport_new_proto_supported_versions();
1074 
1075 		/* We choose the highest possible protocol version and use that
1076 		 * one.
1077 		 */
1078 		pos = fls(proto_int);
1079 		if (pos) {
1080 			active_proto_version = (1 << (pos - 1));
1081 			if (vmci_transport_proto_to_notify_struct(
1082 				pending, &active_proto_version, false))
1083 				err = vmci_transport_send_negotiate2(pending,
1084 							qp_size,
1085 							active_proto_version);
1086 			else
1087 				err = -EINVAL;
1088 
1089 		} else {
1090 			err = -EINVAL;
1091 		}
1092 	}
1093 
1094 	if (err < 0) {
1095 		vmci_transport_send_reset(sk, pkt);
1096 		sock_put(pending);
1097 		err = vmci_transport_error_to_vsock_error(err);
1098 		goto out;
1099 	}
1100 
1101 	vsock_add_pending(sk, pending);
1102 	sk_acceptq_added(sk);
1103 
1104 	pending->sk_state = TCP_SYN_SENT;
1105 	vmci_trans(vpending)->produce_size =
1106 		vmci_trans(vpending)->consume_size = qp_size;
1107 	vpending->buffer_size = qp_size;
1108 
1109 	vmci_trans(vpending)->notify_ops->process_request(pending);
1110 
1111 	/* We might never receive another message for this socket and it's not
1112 	 * connected to any process, so we have to ensure it gets cleaned up
1113 	 * ourself.  Our delayed work function will take care of that.  Note
1114 	 * that we do not ever cancel this function since we have few
1115 	 * guarantees about its state when calling cancel_delayed_work().
1116 	 * Instead we hold a reference on the socket for that function and make
1117 	 * it capable of handling cases where it needs to do nothing but
1118 	 * release that reference.
1119 	 */
1120 	vpending->listener = sk;
1121 	sock_hold(sk);
1122 	sock_hold(pending);
1123 	schedule_delayed_work(&vpending->pending_work, HZ);
1124 
1125 out:
1126 	return err;
1127 }
1128 
1129 static int
1130 vmci_transport_recv_connecting_server(struct sock *listener,
1131 				      struct sock *pending,
1132 				      struct vmci_transport_packet *pkt)
1133 {
1134 	struct vsock_sock *vpending;
1135 	struct vmci_handle handle;
1136 	struct vmci_qp *qpair;
1137 	bool is_local;
1138 	u32 flags;
1139 	u32 detach_sub_id;
1140 	int err;
1141 	int skerr;
1142 
1143 	vpending = vsock_sk(pending);
1144 	detach_sub_id = VMCI_INVALID_ID;
1145 
1146 	switch (pkt->type) {
1147 	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
1148 		if (vmci_handle_is_invalid(pkt->u.handle)) {
1149 			vmci_transport_send_reset(pending, pkt);
1150 			skerr = EPROTO;
1151 			err = -EINVAL;
1152 			goto destroy;
1153 		}
1154 		break;
1155 	default:
1156 		/* Close and cleanup the connection. */
1157 		vmci_transport_send_reset(pending, pkt);
1158 		skerr = EPROTO;
1159 		err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;
1160 		goto destroy;
1161 	}
1162 
1163 	/* In order to complete the connection we need to attach to the offered
1164 	 * queue pair and send an attach notification.  We also subscribe to the
1165 	 * detach event so we know when our peer goes away, and we do that
1166 	 * before attaching so we don't miss an event.  If all this succeeds,
1167 	 * we update our state and wakeup anything waiting in accept() for a
1168 	 * connection.
1169 	 */
1170 
1171 	/* We don't care about attach since we ensure the other side has
1172 	 * attached by specifying the ATTACH_ONLY flag below.
1173 	 */
1174 	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
1175 				   vmci_transport_peer_detach_cb,
1176 				   vmci_trans(vpending), &detach_sub_id);
1177 	if (err < VMCI_SUCCESS) {
1178 		vmci_transport_send_reset(pending, pkt);
1179 		err = vmci_transport_error_to_vsock_error(err);
1180 		skerr = -err;
1181 		goto destroy;
1182 	}
1183 
1184 	vmci_trans(vpending)->detach_sub_id = detach_sub_id;
1185 
1186 	/* Now attach to the queue pair the client created. */
1187 	handle = pkt->u.handle;
1188 
1189 	/* vpending->local_addr always has a context id so we do not need to
1190 	 * worry about VMADDR_CID_ANY in this case.
1191 	 */
1192 	is_local =
1193 	    vpending->remote_addr.svm_cid == vpending->local_addr.svm_cid;
1194 	flags = VMCI_QPFLAG_ATTACH_ONLY;
1195 	flags |= is_local ? VMCI_QPFLAG_LOCAL : 0;
1196 
1197 	err = vmci_transport_queue_pair_alloc(
1198 					&qpair,
1199 					&handle,
1200 					vmci_trans(vpending)->produce_size,
1201 					vmci_trans(vpending)->consume_size,
1202 					pkt->dg.src.context,
1203 					flags,
1204 					vmci_transport_is_trusted(
1205 						vpending,
1206 						vpending->remote_addr.svm_cid));
1207 	if (err < 0) {
1208 		vmci_transport_send_reset(pending, pkt);
1209 		skerr = -err;
1210 		goto destroy;
1211 	}
1212 
1213 	vmci_trans(vpending)->qp_handle = handle;
1214 	vmci_trans(vpending)->qpair = qpair;
1215 
1216 	/* When we send the attach message, we must be ready to handle incoming
1217 	 * control messages on the newly connected socket. So we move the
1218 	 * pending socket to the connected state before sending the attach
1219 	 * message. Otherwise, an incoming packet triggered by the attach being
1220 	 * received by the peer may be processed concurrently with what happens
1221 	 * below after sending the attach message, and that incoming packet
1222 	 * will find the listening socket instead of the (currently) pending
1223 	 * socket. Note that enqueueing the socket increments the reference
1224 	 * count, so even if a reset comes before the connection is accepted,
1225 	 * the socket will be valid until it is removed from the queue.
1226 	 *
1227 	 * If we fail sending the attach below, we remove the socket from the
1228 	 * connected list and move the socket to TCP_CLOSE before
1229 	 * releasing the lock, so a pending slow path processing of an incoming
1230 	 * packet will not see the socket in the connected state in that case.
1231 	 */
1232 	pending->sk_state = TCP_ESTABLISHED;
1233 
1234 	vsock_insert_connected(vpending);
1235 
1236 	/* Notify our peer of our attach. */
1237 	err = vmci_transport_send_attach(pending, handle);
1238 	if (err < 0) {
1239 		vsock_remove_connected(vpending);
1240 		pr_err("Could not send attach\n");
1241 		vmci_transport_send_reset(pending, pkt);
1242 		err = vmci_transport_error_to_vsock_error(err);
1243 		skerr = -err;
1244 		goto destroy;
1245 	}
1246 
1247 	/* We have a connection. Move the now connected socket from the
1248 	 * listener's pending list to the accept queue so callers of accept()
1249 	 * can find it.
1250 	 */
1251 	vsock_remove_pending(listener, pending);
1252 	vsock_enqueue_accept(listener, pending);
1253 
1254 	/* Callers of accept() will be waiting on the listening socket, not
1255 	 * the pending socket.
1256 	 */
1257 	listener->sk_data_ready(listener);
1258 
1259 	return 0;
1260 
1261 destroy:
1262 	pending->sk_err = skerr;
1263 	pending->sk_state = TCP_CLOSE;
1264 	/* As long as we drop our reference, all necessary cleanup will handle
1265 	 * when the cleanup function drops its reference and our destruct
1266 	 * implementation is called.  Note that since the listen handler will
1267 	 * remove pending from the pending list upon our failure, the cleanup
1268 	 * function won't drop the additional reference, which is why we do it
1269 	 * here.
1270 	 */
1271 	sock_put(pending);
1272 
1273 	return err;
1274 }
1275 
1276 static int
1277 vmci_transport_recv_connecting_client(struct sock *sk,
1278 				      struct vmci_transport_packet *pkt)
1279 {
1280 	struct vsock_sock *vsk;
1281 	int err;
1282 	int skerr;
1283 
1284 	vsk = vsock_sk(sk);
1285 
1286 	switch (pkt->type) {
1287 	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
1288 		if (vmci_handle_is_invalid(pkt->u.handle) ||
1289 		    !vmci_handle_is_equal(pkt->u.handle,
1290 					  vmci_trans(vsk)->qp_handle)) {
1291 			skerr = EPROTO;
1292 			err = -EINVAL;
1293 			goto destroy;
1294 		}
1295 
1296 		/* Signify the socket is connected and wakeup the waiter in
1297 		 * connect(). Also place the socket in the connected table for
1298 		 * accounting (it can already be found since it's in the bound
1299 		 * table).
1300 		 */
1301 		sk->sk_state = TCP_ESTABLISHED;
1302 		sk->sk_socket->state = SS_CONNECTED;
1303 		vsock_insert_connected(vsk);
1304 		sk->sk_state_change(sk);
1305 
1306 		break;
1307 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
1308 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
1309 		if (pkt->u.size == 0
1310 		    || pkt->dg.src.context != vsk->remote_addr.svm_cid
1311 		    || pkt->src_port != vsk->remote_addr.svm_port
1312 		    || !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)
1313 		    || vmci_trans(vsk)->qpair
1314 		    || vmci_trans(vsk)->produce_size != 0
1315 		    || vmci_trans(vsk)->consume_size != 0
1316 		    || vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
1317 			skerr = EPROTO;
1318 			err = -EINVAL;
1319 
1320 			goto destroy;
1321 		}
1322 
1323 		err = vmci_transport_recv_connecting_client_negotiate(sk, pkt);
1324 		if (err) {
1325 			skerr = -err;
1326 			goto destroy;
1327 		}
1328 
1329 		break;
1330 	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
1331 		err = vmci_transport_recv_connecting_client_invalid(sk, pkt);
1332 		if (err) {
1333 			skerr = -err;
1334 			goto destroy;
1335 		}
1336 
1337 		break;
1338 	case VMCI_TRANSPORT_PACKET_TYPE_RST:
1339 		/* Older versions of the linux code (WS 6.5 / ESX 4.0) used to
1340 		 * continue processing here after they sent an INVALID packet.
1341 		 * This meant that we got a RST after the INVALID. We ignore a
1342 		 * RST after an INVALID. The common code doesn't send the RST
1343 		 * ... so we can hang if an old version of the common code
1344 		 * fails between getting a REQUEST and sending an OFFER back.
1345 		 * Not much we can do about it... except hope that it doesn't
1346 		 * happen.
1347 		 */
1348 		if (vsk->ignore_connecting_rst) {
1349 			vsk->ignore_connecting_rst = false;
1350 		} else {
1351 			skerr = ECONNRESET;
1352 			err = 0;
1353 			goto destroy;
1354 		}
1355 
1356 		break;
1357 	default:
1358 		/* Close and cleanup the connection. */
1359 		skerr = EPROTO;
1360 		err = -EINVAL;
1361 		goto destroy;
1362 	}
1363 
1364 	return 0;
1365 
1366 destroy:
1367 	vmci_transport_send_reset(sk, pkt);
1368 
1369 	sk->sk_state = TCP_CLOSE;
1370 	sk->sk_err = skerr;
1371 	sk_error_report(sk);
1372 	return err;
1373 }
1374 
1375 static int vmci_transport_recv_connecting_client_negotiate(
1376 					struct sock *sk,
1377 					struct vmci_transport_packet *pkt)
1378 {
1379 	int err;
1380 	struct vsock_sock *vsk;
1381 	struct vmci_handle handle;
1382 	struct vmci_qp *qpair;
1383 	u32 detach_sub_id;
1384 	bool is_local;
1385 	u32 flags;
1386 	bool old_proto = true;
1387 	bool old_pkt_proto;
1388 	u16 version;
1389 
1390 	vsk = vsock_sk(sk);
1391 	handle = VMCI_INVALID_HANDLE;
1392 	detach_sub_id = VMCI_INVALID_ID;
1393 
1394 	/* If we have gotten here then we should be past the point where old
1395 	 * linux vsock could have sent the bogus rst.
1396 	 */
1397 	vsk->sent_request = false;
1398 	vsk->ignore_connecting_rst = false;
1399 
1400 	/* Verify that we're OK with the proposed queue pair size */
1401 	if (pkt->u.size < vsk->buffer_min_size ||
1402 	    pkt->u.size > vsk->buffer_max_size) {
1403 		err = -EINVAL;
1404 		goto destroy;
1405 	}
1406 
1407 	/* At this point we know the CID the peer is using to talk to us. */
1408 
1409 	if (vsk->local_addr.svm_cid == VMADDR_CID_ANY)
1410 		vsk->local_addr.svm_cid = pkt->dg.dst.context;
1411 
1412 	/* Setup the notify ops to be the highest supported version that both
1413 	 * the server and the client support.
1414 	 */
1415 
1416 	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
1417 		old_proto = old_pkt_proto;
1418 	} else {
1419 		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE)
1420 			old_proto = true;
1421 		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2)
1422 			old_proto = false;
1423 
1424 	}
1425 
1426 	if (old_proto)
1427 		version = VSOCK_PROTO_INVALID;
1428 	else
1429 		version = pkt->proto;
1430 
1431 	if (!vmci_transport_proto_to_notify_struct(sk, &version, old_proto)) {
1432 		err = -EINVAL;
1433 		goto destroy;
1434 	}
1435 
1436 	/* Subscribe to detach events first.
1437 	 *
1438 	 * XXX We attach once for each queue pair created for now so it is easy
1439 	 * to find the socket (it's provided), but later we should only
1440 	 * subscribe once and add a way to lookup sockets by queue pair handle.
1441 	 */
1442 	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
1443 				   vmci_transport_peer_detach_cb,
1444 				   vmci_trans(vsk), &detach_sub_id);
1445 	if (err < VMCI_SUCCESS) {
1446 		err = vmci_transport_error_to_vsock_error(err);
1447 		goto destroy;
1448 	}
1449 
1450 	/* Make VMCI select the handle for us. */
1451 	handle = VMCI_INVALID_HANDLE;
1452 	is_local = vsk->remote_addr.svm_cid == vsk->local_addr.svm_cid;
1453 	flags = is_local ? VMCI_QPFLAG_LOCAL : 0;
1454 
1455 	err = vmci_transport_queue_pair_alloc(&qpair,
1456 					      &handle,
1457 					      pkt->u.size,
1458 					      pkt->u.size,
1459 					      vsk->remote_addr.svm_cid,
1460 					      flags,
1461 					      vmci_transport_is_trusted(
1462 						  vsk,
1463 						  vsk->
1464 						  remote_addr.svm_cid));
1465 	if (err < 0)
1466 		goto destroy;
1467 
1468 	err = vmci_transport_send_qp_offer(sk, handle);
1469 	if (err < 0) {
1470 		err = vmci_transport_error_to_vsock_error(err);
1471 		goto destroy;
1472 	}
1473 
1474 	vmci_trans(vsk)->qp_handle = handle;
1475 	vmci_trans(vsk)->qpair = qpair;
1476 
1477 	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size =
1478 		pkt->u.size;
1479 
1480 	vmci_trans(vsk)->detach_sub_id = detach_sub_id;
1481 
1482 	vmci_trans(vsk)->notify_ops->process_negotiate(sk);
1483 
1484 	return 0;
1485 
1486 destroy:
1487 	if (detach_sub_id != VMCI_INVALID_ID)
1488 		vmci_event_unsubscribe(detach_sub_id);
1489 
1490 	if (!vmci_handle_is_invalid(handle))
1491 		vmci_qpair_detach(&qpair);
1492 
1493 	return err;
1494 }
1495 
1496 static int
1497 vmci_transport_recv_connecting_client_invalid(struct sock *sk,
1498 					      struct vmci_transport_packet *pkt)
1499 {
1500 	int err = 0;
1501 	struct vsock_sock *vsk = vsock_sk(sk);
1502 
1503 	if (vsk->sent_request) {
1504 		vsk->sent_request = false;
1505 		vsk->ignore_connecting_rst = true;
1506 
1507 		err = vmci_transport_send_conn_request(sk, vsk->buffer_size);
1508 		if (err < 0)
1509 			err = vmci_transport_error_to_vsock_error(err);
1510 		else
1511 			err = 0;
1512 
1513 	}
1514 
1515 	return err;
1516 }
1517 
1518 static int vmci_transport_recv_connected(struct sock *sk,
1519 					 struct vmci_transport_packet *pkt)
1520 {
1521 	struct vsock_sock *vsk;
1522 	bool pkt_processed = false;
1523 
1524 	/* In cases where we are closing the connection, it's sufficient to
1525 	 * mark the state change (and maybe error) and wake up any waiting
1526 	 * threads. Since this is a connected socket, it's owned by a user
1527 	 * process and will be cleaned up when the failure is passed back on
1528 	 * the current or next system call.  Our system call implementations
1529 	 * must therefore check for error and state changes on entry and when
1530 	 * being awoken.
1531 	 */
1532 	switch (pkt->type) {
1533 	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
1534 		if (pkt->u.mode) {
1535 			vsk = vsock_sk(sk);
1536 
1537 			vsk->peer_shutdown |= pkt->u.mode;
1538 			sk->sk_state_change(sk);
1539 		}
1540 		break;
1541 
1542 	case VMCI_TRANSPORT_PACKET_TYPE_RST:
1543 		vsk = vsock_sk(sk);
1544 		/* It is possible that we sent our peer a message (e.g a
1545 		 * WAITING_READ) right before we got notified that the peer had
1546 		 * detached. If that happens then we can get a RST pkt back
1547 		 * from our peer even though there is data available for us to
1548 		 * read. In that case, don't shutdown the socket completely but
1549 		 * instead allow the local client to finish reading data off
1550 		 * the queuepair. Always treat a RST pkt in connected mode like
1551 		 * a clean shutdown.
1552 		 */
1553 		sock_set_flag(sk, SOCK_DONE);
1554 		vsk->peer_shutdown = SHUTDOWN_MASK;
1555 		if (vsock_stream_has_data(vsk) <= 0)
1556 			sk->sk_state = TCP_CLOSING;
1557 
1558 		sk->sk_state_change(sk);
1559 		break;
1560 
1561 	default:
1562 		vsk = vsock_sk(sk);
1563 		vmci_trans(vsk)->notify_ops->handle_notify_pkt(
1564 				sk, pkt, false, NULL, NULL,
1565 				&pkt_processed);
1566 		if (!pkt_processed)
1567 			return -EINVAL;
1568 
1569 		break;
1570 	}
1571 
1572 	return 0;
1573 }
1574 
1575 static int vmci_transport_socket_init(struct vsock_sock *vsk,
1576 				      struct vsock_sock *psk)
1577 {
1578 	vsk->trans = kmalloc(sizeof(struct vmci_transport), GFP_KERNEL);
1579 	if (!vsk->trans)
1580 		return -ENOMEM;
1581 
1582 	vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
1583 	vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
1584 	vmci_trans(vsk)->qpair = NULL;
1585 	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size = 0;
1586 	vmci_trans(vsk)->detach_sub_id = VMCI_INVALID_ID;
1587 	vmci_trans(vsk)->notify_ops = NULL;
1588 	INIT_LIST_HEAD(&vmci_trans(vsk)->elem);
1589 	vmci_trans(vsk)->sk = &vsk->sk;
1590 	spin_lock_init(&vmci_trans(vsk)->lock);
1591 
1592 	return 0;
1593 }
1594 
1595 static void vmci_transport_free_resources(struct list_head *transport_list)
1596 {
1597 	while (!list_empty(transport_list)) {
1598 		struct vmci_transport *transport =
1599 		    list_first_entry(transport_list, struct vmci_transport,
1600 				     elem);
1601 		list_del(&transport->elem);
1602 
1603 		if (transport->detach_sub_id != VMCI_INVALID_ID) {
1604 			vmci_event_unsubscribe(transport->detach_sub_id);
1605 			transport->detach_sub_id = VMCI_INVALID_ID;
1606 		}
1607 
1608 		if (!vmci_handle_is_invalid(transport->qp_handle)) {
1609 			vmci_qpair_detach(&transport->qpair);
1610 			transport->qp_handle = VMCI_INVALID_HANDLE;
1611 			transport->produce_size = 0;
1612 			transport->consume_size = 0;
1613 		}
1614 
1615 		kfree(transport);
1616 	}
1617 }
1618 
1619 static void vmci_transport_cleanup(struct work_struct *work)
1620 {
1621 	LIST_HEAD(pending);
1622 
1623 	spin_lock_bh(&vmci_transport_cleanup_lock);
1624 	list_replace_init(&vmci_transport_cleanup_list, &pending);
1625 	spin_unlock_bh(&vmci_transport_cleanup_lock);
1626 	vmci_transport_free_resources(&pending);
1627 }
1628 
1629 static void vmci_transport_destruct(struct vsock_sock *vsk)
1630 {
1631 	/* transport can be NULL if we hit a failure at init() time */
1632 	if (!vmci_trans(vsk))
1633 		return;
1634 
1635 	/* Ensure that the detach callback doesn't use the sk/vsk
1636 	 * we are about to destruct.
1637 	 */
1638 	spin_lock_bh(&vmci_trans(vsk)->lock);
1639 	vmci_trans(vsk)->sk = NULL;
1640 	spin_unlock_bh(&vmci_trans(vsk)->lock);
1641 
1642 	if (vmci_trans(vsk)->notify_ops)
1643 		vmci_trans(vsk)->notify_ops->socket_destruct(vsk);
1644 
1645 	spin_lock_bh(&vmci_transport_cleanup_lock);
1646 	list_add(&vmci_trans(vsk)->elem, &vmci_transport_cleanup_list);
1647 	spin_unlock_bh(&vmci_transport_cleanup_lock);
1648 	schedule_work(&vmci_transport_cleanup_work);
1649 
1650 	vsk->trans = NULL;
1651 }
1652 
1653 static void vmci_transport_release(struct vsock_sock *vsk)
1654 {
1655 	vsock_remove_sock(vsk);
1656 
1657 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->dg_handle)) {
1658 		vmci_datagram_destroy_handle(vmci_trans(vsk)->dg_handle);
1659 		vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
1660 	}
1661 }
1662 
1663 static int vmci_transport_dgram_bind(struct vsock_sock *vsk,
1664 				     struct sockaddr_vm *addr)
1665 {
1666 	u32 port;
1667 	u32 flags;
1668 	int err;
1669 
1670 	/* VMCI will select a resource ID for us if we provide
1671 	 * VMCI_INVALID_ID.
1672 	 */
1673 	port = addr->svm_port == VMADDR_PORT_ANY ?
1674 			VMCI_INVALID_ID : addr->svm_port;
1675 
1676 	if (port <= LAST_RESERVED_PORT && !capable(CAP_NET_BIND_SERVICE))
1677 		return -EACCES;
1678 
1679 	flags = addr->svm_cid == VMADDR_CID_ANY ?
1680 				VMCI_FLAG_ANYCID_DG_HND : 0;
1681 
1682 	err = vmci_transport_datagram_create_hnd(port, flags,
1683 						 vmci_transport_recv_dgram_cb,
1684 						 &vsk->sk,
1685 						 &vmci_trans(vsk)->dg_handle);
1686 	if (err < VMCI_SUCCESS)
1687 		return vmci_transport_error_to_vsock_error(err);
1688 	vsock_addr_init(&vsk->local_addr, addr->svm_cid,
1689 			vmci_trans(vsk)->dg_handle.resource);
1690 
1691 	return 0;
1692 }
1693 
1694 static int vmci_transport_dgram_enqueue(
1695 	struct vsock_sock *vsk,
1696 	struct sockaddr_vm *remote_addr,
1697 	struct msghdr *msg,
1698 	size_t len)
1699 {
1700 	int err;
1701 	struct vmci_datagram *dg;
1702 
1703 	if (len > VMCI_MAX_DG_PAYLOAD_SIZE)
1704 		return -EMSGSIZE;
1705 
1706 	if (!vmci_transport_allow_dgram(vsk, remote_addr->svm_cid))
1707 		return -EPERM;
1708 
1709 	/* Allocate a buffer for the user's message and our packet header. */
1710 	dg = kmalloc(len + sizeof(*dg), GFP_KERNEL);
1711 	if (!dg)
1712 		return -ENOMEM;
1713 
1714 	err = memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);
1715 	if (err) {
1716 		kfree(dg);
1717 		return err;
1718 	}
1719 
1720 	dg->dst = vmci_make_handle(remote_addr->svm_cid,
1721 				   remote_addr->svm_port);
1722 	dg->src = vmci_make_handle(vsk->local_addr.svm_cid,
1723 				   vsk->local_addr.svm_port);
1724 	dg->payload_size = len;
1725 
1726 	err = vmci_datagram_send(dg);
1727 	kfree(dg);
1728 	if (err < 0)
1729 		return vmci_transport_error_to_vsock_error(err);
1730 
1731 	return err - sizeof(*dg);
1732 }
1733 
1734 static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
1735 					struct msghdr *msg, size_t len,
1736 					int flags)
1737 {
1738 	int err;
1739 	struct vmci_datagram *dg;
1740 	size_t payload_len;
1741 	struct sk_buff *skb;
1742 
1743 	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
1744 		return -EOPNOTSUPP;
1745 
1746 	/* Retrieve the head sk_buff from the socket's receive queue. */
1747 	err = 0;
1748 	skb = skb_recv_datagram(&vsk->sk, flags, &err);
1749 	if (!skb)
1750 		return err;
1751 
1752 	dg = (struct vmci_datagram *)skb->data;
1753 	if (!dg)
1754 		/* err is 0, meaning we read zero bytes. */
1755 		goto out;
1756 
1757 	payload_len = dg->payload_size;
1758 	/* Ensure the sk_buff matches the payload size claimed in the packet. */
1759 	if (payload_len != skb->len - sizeof(*dg)) {
1760 		err = -EINVAL;
1761 		goto out;
1762 	}
1763 
1764 	if (payload_len > len) {
1765 		payload_len = len;
1766 		msg->msg_flags |= MSG_TRUNC;
1767 	}
1768 
1769 	/* Place the datagram payload in the user's iovec. */
1770 	err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len);
1771 	if (err)
1772 		goto out;
1773 
1774 	if (msg->msg_name) {
1775 		/* Provide the address of the sender. */
1776 		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
1777 		vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
1778 		msg->msg_namelen = sizeof(*vm_addr);
1779 	}
1780 	err = payload_len;
1781 
1782 out:
1783 	skb_free_datagram(&vsk->sk, skb);
1784 	return err;
1785 }
1786 
1787 static bool vmci_transport_dgram_allow(u32 cid, u32 port)
1788 {
1789 	if (cid == VMADDR_CID_HYPERVISOR) {
1790 		/* Registrations of PBRPC Servers do not modify VMX/Hypervisor
1791 		 * state and are allowed.
1792 		 */
1793 		return port == VMCI_UNITY_PBRPC_REGISTER;
1794 	}
1795 
1796 	return true;
1797 }
1798 
1799 static int vmci_transport_connect(struct vsock_sock *vsk)
1800 {
1801 	int err;
1802 	bool old_pkt_proto = false;
1803 	struct sock *sk = &vsk->sk;
1804 
1805 	if (vmci_transport_old_proto_override(&old_pkt_proto) &&
1806 		old_pkt_proto) {
1807 		err = vmci_transport_send_conn_request(sk, vsk->buffer_size);
1808 		if (err < 0) {
1809 			sk->sk_state = TCP_CLOSE;
1810 			return err;
1811 		}
1812 	} else {
1813 		int supported_proto_versions =
1814 			vmci_transport_new_proto_supported_versions();
1815 		err = vmci_transport_send_conn_request2(sk, vsk->buffer_size,
1816 				supported_proto_versions);
1817 		if (err < 0) {
1818 			sk->sk_state = TCP_CLOSE;
1819 			return err;
1820 		}
1821 
1822 		vsk->sent_request = true;
1823 	}
1824 
1825 	return err;
1826 }
1827 
1828 static ssize_t vmci_transport_stream_dequeue(
1829 	struct vsock_sock *vsk,
1830 	struct msghdr *msg,
1831 	size_t len,
1832 	int flags)
1833 {
1834 	ssize_t err;
1835 
1836 	if (flags & MSG_PEEK)
1837 		err = vmci_qpair_peekv(vmci_trans(vsk)->qpair, msg, len, 0);
1838 	else
1839 		err = vmci_qpair_dequev(vmci_trans(vsk)->qpair, msg, len, 0);
1840 
1841 	if (err < 0)
1842 		err = -ENOMEM;
1843 
1844 	return err;
1845 }
1846 
1847 static ssize_t vmci_transport_stream_enqueue(
1848 	struct vsock_sock *vsk,
1849 	struct msghdr *msg,
1850 	size_t len)
1851 {
1852 	ssize_t err;
1853 
1854 	err = vmci_qpair_enquev(vmci_trans(vsk)->qpair, msg, len, 0);
1855 	if (err < 0)
1856 		err = -ENOMEM;
1857 
1858 	return err;
1859 }
1860 
1861 static s64 vmci_transport_stream_has_data(struct vsock_sock *vsk)
1862 {
1863 	return vmci_qpair_consume_buf_ready(vmci_trans(vsk)->qpair);
1864 }
1865 
1866 static s64 vmci_transport_stream_has_space(struct vsock_sock *vsk)
1867 {
1868 	return vmci_qpair_produce_free_space(vmci_trans(vsk)->qpair);
1869 }
1870 
1871 static u64 vmci_transport_stream_rcvhiwat(struct vsock_sock *vsk)
1872 {
1873 	return vmci_trans(vsk)->consume_size;
1874 }
1875 
1876 static bool vmci_transport_stream_is_active(struct vsock_sock *vsk)
1877 {
1878 	return !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle);
1879 }
1880 
1881 static int vmci_transport_notify_poll_in(
1882 	struct vsock_sock *vsk,
1883 	size_t target,
1884 	bool *data_ready_now)
1885 {
1886 	return vmci_trans(vsk)->notify_ops->poll_in(
1887 			&vsk->sk, target, data_ready_now);
1888 }
1889 
1890 static int vmci_transport_notify_poll_out(
1891 	struct vsock_sock *vsk,
1892 	size_t target,
1893 	bool *space_available_now)
1894 {
1895 	return vmci_trans(vsk)->notify_ops->poll_out(
1896 			&vsk->sk, target, space_available_now);
1897 }
1898 
1899 static int vmci_transport_notify_recv_init(
1900 	struct vsock_sock *vsk,
1901 	size_t target,
1902 	struct vsock_transport_recv_notify_data *data)
1903 {
1904 	return vmci_trans(vsk)->notify_ops->recv_init(
1905 			&vsk->sk, target,
1906 			(struct vmci_transport_recv_notify_data *)data);
1907 }
1908 
1909 static int vmci_transport_notify_recv_pre_block(
1910 	struct vsock_sock *vsk,
1911 	size_t target,
1912 	struct vsock_transport_recv_notify_data *data)
1913 {
1914 	return vmci_trans(vsk)->notify_ops->recv_pre_block(
1915 			&vsk->sk, target,
1916 			(struct vmci_transport_recv_notify_data *)data);
1917 }
1918 
1919 static int vmci_transport_notify_recv_pre_dequeue(
1920 	struct vsock_sock *vsk,
1921 	size_t target,
1922 	struct vsock_transport_recv_notify_data *data)
1923 {
1924 	return vmci_trans(vsk)->notify_ops->recv_pre_dequeue(
1925 			&vsk->sk, target,
1926 			(struct vmci_transport_recv_notify_data *)data);
1927 }
1928 
1929 static int vmci_transport_notify_recv_post_dequeue(
1930 	struct vsock_sock *vsk,
1931 	size_t target,
1932 	ssize_t copied,
1933 	bool data_read,
1934 	struct vsock_transport_recv_notify_data *data)
1935 {
1936 	return vmci_trans(vsk)->notify_ops->recv_post_dequeue(
1937 			&vsk->sk, target, copied, data_read,
1938 			(struct vmci_transport_recv_notify_data *)data);
1939 }
1940 
1941 static int vmci_transport_notify_send_init(
1942 	struct vsock_sock *vsk,
1943 	struct vsock_transport_send_notify_data *data)
1944 {
1945 	return vmci_trans(vsk)->notify_ops->send_init(
1946 			&vsk->sk,
1947 			(struct vmci_transport_send_notify_data *)data);
1948 }
1949 
1950 static int vmci_transport_notify_send_pre_block(
1951 	struct vsock_sock *vsk,
1952 	struct vsock_transport_send_notify_data *data)
1953 {
1954 	return vmci_trans(vsk)->notify_ops->send_pre_block(
1955 			&vsk->sk,
1956 			(struct vmci_transport_send_notify_data *)data);
1957 }
1958 
1959 static int vmci_transport_notify_send_pre_enqueue(
1960 	struct vsock_sock *vsk,
1961 	struct vsock_transport_send_notify_data *data)
1962 {
1963 	return vmci_trans(vsk)->notify_ops->send_pre_enqueue(
1964 			&vsk->sk,
1965 			(struct vmci_transport_send_notify_data *)data);
1966 }
1967 
1968 static int vmci_transport_notify_send_post_enqueue(
1969 	struct vsock_sock *vsk,
1970 	ssize_t written,
1971 	struct vsock_transport_send_notify_data *data)
1972 {
1973 	return vmci_trans(vsk)->notify_ops->send_post_enqueue(
1974 			&vsk->sk, written,
1975 			(struct vmci_transport_send_notify_data *)data);
1976 }
1977 
1978 static bool vmci_transport_old_proto_override(bool *old_pkt_proto)
1979 {
1980 	if (PROTOCOL_OVERRIDE != -1) {
1981 		if (PROTOCOL_OVERRIDE == 0)
1982 			*old_pkt_proto = true;
1983 		else
1984 			*old_pkt_proto = false;
1985 
1986 		pr_info("Proto override in use\n");
1987 		return true;
1988 	}
1989 
1990 	return false;
1991 }
1992 
1993 static bool vmci_transport_proto_to_notify_struct(struct sock *sk,
1994 						  u16 *proto,
1995 						  bool old_pkt_proto)
1996 {
1997 	struct vsock_sock *vsk = vsock_sk(sk);
1998 
1999 	if (old_pkt_proto) {
2000 		if (*proto != VSOCK_PROTO_INVALID) {
2001 			pr_err("Can't set both an old and new protocol\n");
2002 			return false;
2003 		}
2004 		vmci_trans(vsk)->notify_ops = &vmci_transport_notify_pkt_ops;
2005 		goto exit;
2006 	}
2007 
2008 	switch (*proto) {
2009 	case VSOCK_PROTO_PKT_ON_NOTIFY:
2010 		vmci_trans(vsk)->notify_ops =
2011 			&vmci_transport_notify_pkt_q_state_ops;
2012 		break;
2013 	default:
2014 		pr_err("Unknown notify protocol version\n");
2015 		return false;
2016 	}
2017 
2018 exit:
2019 	vmci_trans(vsk)->notify_ops->socket_init(sk);
2020 	return true;
2021 }
2022 
2023 static u16 vmci_transport_new_proto_supported_versions(void)
2024 {
2025 	if (PROTOCOL_OVERRIDE != -1)
2026 		return PROTOCOL_OVERRIDE;
2027 
2028 	return VSOCK_PROTO_ALL_SUPPORTED;
2029 }
2030 
2031 static u32 vmci_transport_get_local_cid(void)
2032 {
2033 	return vmci_get_context_id();
2034 }
2035 
2036 static struct vsock_transport vmci_transport = {
2037 	.module = THIS_MODULE,
2038 	.init = vmci_transport_socket_init,
2039 	.destruct = vmci_transport_destruct,
2040 	.release = vmci_transport_release,
2041 	.connect = vmci_transport_connect,
2042 	.dgram_bind = vmci_transport_dgram_bind,
2043 	.dgram_dequeue = vmci_transport_dgram_dequeue,
2044 	.dgram_enqueue = vmci_transport_dgram_enqueue,
2045 	.dgram_allow = vmci_transport_dgram_allow,
2046 	.stream_dequeue = vmci_transport_stream_dequeue,
2047 	.stream_enqueue = vmci_transport_stream_enqueue,
2048 	.stream_has_data = vmci_transport_stream_has_data,
2049 	.stream_has_space = vmci_transport_stream_has_space,
2050 	.stream_rcvhiwat = vmci_transport_stream_rcvhiwat,
2051 	.stream_is_active = vmci_transport_stream_is_active,
2052 	.stream_allow = vmci_transport_stream_allow,
2053 	.notify_poll_in = vmci_transport_notify_poll_in,
2054 	.notify_poll_out = vmci_transport_notify_poll_out,
2055 	.notify_recv_init = vmci_transport_notify_recv_init,
2056 	.notify_recv_pre_block = vmci_transport_notify_recv_pre_block,
2057 	.notify_recv_pre_dequeue = vmci_transport_notify_recv_pre_dequeue,
2058 	.notify_recv_post_dequeue = vmci_transport_notify_recv_post_dequeue,
2059 	.notify_send_init = vmci_transport_notify_send_init,
2060 	.notify_send_pre_block = vmci_transport_notify_send_pre_block,
2061 	.notify_send_pre_enqueue = vmci_transport_notify_send_pre_enqueue,
2062 	.notify_send_post_enqueue = vmci_transport_notify_send_post_enqueue,
2063 	.shutdown = vmci_transport_shutdown,
2064 	.get_local_cid = vmci_transport_get_local_cid,
2065 };
2066 
2067 static bool vmci_check_transport(struct vsock_sock *vsk)
2068 {
2069 	return vsk->transport == &vmci_transport;
2070 }
2071 
2072 static void vmci_vsock_transport_cb(bool is_host)
2073 {
2074 	int features;
2075 
2076 	if (is_host)
2077 		features = VSOCK_TRANSPORT_F_H2G;
2078 	else
2079 		features = VSOCK_TRANSPORT_F_G2H;
2080 
2081 	vsock_core_register(&vmci_transport, features);
2082 }
2083 
2084 static int __init vmci_transport_init(void)
2085 {
2086 	int err;
2087 
2088 	/* Create the datagram handle that we will use to send and receive all
2089 	 * VSocket control messages for this context.
2090 	 */
2091 	err = vmci_transport_datagram_create_hnd(VMCI_TRANSPORT_PACKET_RID,
2092 						 VMCI_FLAG_ANYCID_DG_HND,
2093 						 vmci_transport_recv_stream_cb,
2094 						 NULL,
2095 						 &vmci_transport_stream_handle);
2096 	if (err < VMCI_SUCCESS) {
2097 		pr_err("Unable to create datagram handle. (%d)\n", err);
2098 		return vmci_transport_error_to_vsock_error(err);
2099 	}
2100 	err = vmci_event_subscribe(VMCI_EVENT_QP_RESUMED,
2101 				   vmci_transport_qp_resumed_cb,
2102 				   NULL, &vmci_transport_qp_resumed_sub_id);
2103 	if (err < VMCI_SUCCESS) {
2104 		pr_err("Unable to subscribe to resumed event. (%d)\n", err);
2105 		err = vmci_transport_error_to_vsock_error(err);
2106 		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
2107 		goto err_destroy_stream_handle;
2108 	}
2109 
2110 	/* Register only with dgram feature, other features (H2G, G2H) will be
2111 	 * registered when the first host or guest becomes active.
2112 	 */
2113 	err = vsock_core_register(&vmci_transport, VSOCK_TRANSPORT_F_DGRAM);
2114 	if (err < 0)
2115 		goto err_unsubscribe;
2116 
2117 	err = vmci_register_vsock_callback(vmci_vsock_transport_cb);
2118 	if (err < 0)
2119 		goto err_unregister;
2120 
2121 	return 0;
2122 
2123 err_unregister:
2124 	vsock_core_unregister(&vmci_transport);
2125 err_unsubscribe:
2126 	vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
2127 err_destroy_stream_handle:
2128 	vmci_datagram_destroy_handle(vmci_transport_stream_handle);
2129 	return err;
2130 }
2131 module_init(vmci_transport_init);
2132 
2133 static void __exit vmci_transport_exit(void)
2134 {
2135 	cancel_work_sync(&vmci_transport_cleanup_work);
2136 	vmci_transport_free_resources(&vmci_transport_cleanup_list);
2137 
2138 	if (!vmci_handle_is_invalid(vmci_transport_stream_handle)) {
2139 		if (vmci_datagram_destroy_handle(
2140 			vmci_transport_stream_handle) != VMCI_SUCCESS)
2141 			pr_err("Couldn't destroy datagram handle\n");
2142 		vmci_transport_stream_handle = VMCI_INVALID_HANDLE;
2143 	}
2144 
2145 	if (vmci_transport_qp_resumed_sub_id != VMCI_INVALID_ID) {
2146 		vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
2147 		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
2148 	}
2149 
2150 	vmci_register_vsock_callback(NULL);
2151 	vsock_core_unregister(&vmci_transport);
2152 }
2153 module_exit(vmci_transport_exit);
2154 
2155 MODULE_AUTHOR("VMware, Inc.");
2156 MODULE_DESCRIPTION("VMCI transport for Virtual Sockets");
2157 MODULE_VERSION("1.0.5.0-k");
2158 MODULE_LICENSE("GPL v2");
2159 MODULE_ALIAS("vmware_vsock");
2160 MODULE_ALIAS_NETPROTO(PF_VSOCK);
2161