1 /*
2  * VMware vSockets Driver
3  *
4  * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation version 2 and no later version.
9  *
10  * This program is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  */
15 
16 #include <linux/types.h>
17 #include <linux/bitops.h>
18 #include <linux/cred.h>
19 #include <linux/init.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/kmod.h>
23 #include <linux/list.h>
24 #include <linux/miscdevice.h>
25 #include <linux/module.h>
26 #include <linux/mutex.h>
27 #include <linux/net.h>
28 #include <linux/poll.h>
29 #include <linux/skbuff.h>
30 #include <linux/smp.h>
31 #include <linux/socket.h>
32 #include <linux/stddef.h>
33 #include <linux/unistd.h>
34 #include <linux/wait.h>
35 #include <linux/workqueue.h>
36 #include <net/sock.h>
37 
38 #include "af_vsock.h"
39 #include "vmci_transport_notify.h"
40 
41 static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg);
42 static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg);
43 static void vmci_transport_peer_attach_cb(u32 sub_id,
44 					  const struct vmci_event_data *ed,
45 					  void *client_data);
46 static void vmci_transport_peer_detach_cb(u32 sub_id,
47 					  const struct vmci_event_data *ed,
48 					  void *client_data);
49 static void vmci_transport_recv_pkt_work(struct work_struct *work);
50 static int vmci_transport_recv_listen(struct sock *sk,
51 				      struct vmci_transport_packet *pkt);
52 static int vmci_transport_recv_connecting_server(
53 					struct sock *sk,
54 					struct sock *pending,
55 					struct vmci_transport_packet *pkt);
56 static int vmci_transport_recv_connecting_client(
57 					struct sock *sk,
58 					struct vmci_transport_packet *pkt);
59 static int vmci_transport_recv_connecting_client_negotiate(
60 					struct sock *sk,
61 					struct vmci_transport_packet *pkt);
62 static int vmci_transport_recv_connecting_client_invalid(
63 					struct sock *sk,
64 					struct vmci_transport_packet *pkt);
65 static int vmci_transport_recv_connected(struct sock *sk,
66 					 struct vmci_transport_packet *pkt);
67 static bool vmci_transport_old_proto_override(bool *old_pkt_proto);
68 static u16 vmci_transport_new_proto_supported_versions(void);
69 static bool vmci_transport_proto_to_notify_struct(struct sock *sk, u16 *proto,
70 						  bool old_pkt_proto);
71 
72 struct vmci_transport_recv_pkt_info {
73 	struct work_struct work;
74 	struct sock *sk;
75 	struct vmci_transport_packet pkt;
76 };
77 
78 static struct vmci_handle vmci_transport_stream_handle = { VMCI_INVALID_ID,
79 							   VMCI_INVALID_ID };
80 static u32 vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
81 
82 static int PROTOCOL_OVERRIDE = -1;
83 
84 #define VMCI_TRANSPORT_DEFAULT_QP_SIZE_MIN   128
85 #define VMCI_TRANSPORT_DEFAULT_QP_SIZE       262144
86 #define VMCI_TRANSPORT_DEFAULT_QP_SIZE_MAX   262144
87 
88 /* The default peer timeout indicates how long we will wait for a peer response
89  * to a control message.
90  */
91 #define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
92 
93 #define SS_LISTEN 255
94 
95 /* Helper function to convert from a VMCI error code to a VSock error code. */
96 
97 static s32 vmci_transport_error_to_vsock_error(s32 vmci_error)
98 {
99 	int err;
100 
101 	switch (vmci_error) {
102 	case VMCI_ERROR_NO_MEM:
103 		err = ENOMEM;
104 		break;
105 	case VMCI_ERROR_DUPLICATE_ENTRY:
106 	case VMCI_ERROR_ALREADY_EXISTS:
107 		err = EADDRINUSE;
108 		break;
109 	case VMCI_ERROR_NO_ACCESS:
110 		err = EPERM;
111 		break;
112 	case VMCI_ERROR_NO_RESOURCES:
113 		err = ENOBUFS;
114 		break;
115 	case VMCI_ERROR_INVALID_RESOURCE:
116 		err = EHOSTUNREACH;
117 		break;
118 	case VMCI_ERROR_INVALID_ARGS:
119 	default:
120 		err = EINVAL;
121 	}
122 
123 	return err > 0 ? -err : err;
124 }
125 
126 static inline void
127 vmci_transport_packet_init(struct vmci_transport_packet *pkt,
128 			   struct sockaddr_vm *src,
129 			   struct sockaddr_vm *dst,
130 			   u8 type,
131 			   u64 size,
132 			   u64 mode,
133 			   struct vmci_transport_waiting_info *wait,
134 			   u16 proto,
135 			   struct vmci_handle handle)
136 {
137 	/* We register the stream control handler as an any cid handle so we
138 	 * must always send from a source address of VMADDR_CID_ANY
139 	 */
140 	pkt->dg.src = vmci_make_handle(VMADDR_CID_ANY,
141 				       VMCI_TRANSPORT_PACKET_RID);
142 	pkt->dg.dst = vmci_make_handle(dst->svm_cid,
143 				       VMCI_TRANSPORT_PACKET_RID);
144 	pkt->dg.payload_size = sizeof(*pkt) - sizeof(pkt->dg);
145 	pkt->version = VMCI_TRANSPORT_PACKET_VERSION;
146 	pkt->type = type;
147 	pkt->src_port = src->svm_port;
148 	pkt->dst_port = dst->svm_port;
149 	memset(&pkt->proto, 0, sizeof(pkt->proto));
150 	memset(&pkt->_reserved2, 0, sizeof(pkt->_reserved2));
151 
152 	switch (pkt->type) {
153 	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
154 		pkt->u.size = 0;
155 		break;
156 
157 	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST:
158 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
159 		pkt->u.size = size;
160 		break;
161 
162 	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
163 	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
164 		pkt->u.handle = handle;
165 		break;
166 
167 	case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
168 	case VMCI_TRANSPORT_PACKET_TYPE_READ:
169 	case VMCI_TRANSPORT_PACKET_TYPE_RST:
170 		pkt->u.size = 0;
171 		break;
172 
173 	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
174 		pkt->u.mode = mode;
175 		break;
176 
177 	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
178 	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
179 		memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
180 		break;
181 
182 	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2:
183 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
184 		pkt->u.size = size;
185 		pkt->proto = proto;
186 		break;
187 	}
188 }
189 
190 static inline void
191 vmci_transport_packet_get_addresses(struct vmci_transport_packet *pkt,
192 				    struct sockaddr_vm *local,
193 				    struct sockaddr_vm *remote)
194 {
195 	vsock_addr_init(local, pkt->dg.dst.context, pkt->dst_port);
196 	vsock_addr_init(remote, pkt->dg.src.context, pkt->src_port);
197 }
198 
199 static int
200 __vmci_transport_send_control_pkt(struct vmci_transport_packet *pkt,
201 				  struct sockaddr_vm *src,
202 				  struct sockaddr_vm *dst,
203 				  enum vmci_transport_packet_type type,
204 				  u64 size,
205 				  u64 mode,
206 				  struct vmci_transport_waiting_info *wait,
207 				  u16 proto,
208 				  struct vmci_handle handle,
209 				  bool convert_error)
210 {
211 	int err;
212 
213 	vmci_transport_packet_init(pkt, src, dst, type, size, mode, wait,
214 				   proto, handle);
215 	err = vmci_datagram_send(&pkt->dg);
216 	if (convert_error && (err < 0))
217 		return vmci_transport_error_to_vsock_error(err);
218 
219 	return err;
220 }
221 
222 static int
223 vmci_transport_reply_control_pkt_fast(struct vmci_transport_packet *pkt,
224 				      enum vmci_transport_packet_type type,
225 				      u64 size,
226 				      u64 mode,
227 				      struct vmci_transport_waiting_info *wait,
228 				      struct vmci_handle handle)
229 {
230 	struct vmci_transport_packet reply;
231 	struct sockaddr_vm src, dst;
232 
233 	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST) {
234 		return 0;
235 	} else {
236 		vmci_transport_packet_get_addresses(pkt, &src, &dst);
237 		return __vmci_transport_send_control_pkt(&reply, &src, &dst,
238 							 type,
239 							 size, mode, wait,
240 							 VSOCK_PROTO_INVALID,
241 							 handle, true);
242 	}
243 }
244 
245 static int
246 vmci_transport_send_control_pkt_bh(struct sockaddr_vm *src,
247 				   struct sockaddr_vm *dst,
248 				   enum vmci_transport_packet_type type,
249 				   u64 size,
250 				   u64 mode,
251 				   struct vmci_transport_waiting_info *wait,
252 				   struct vmci_handle handle)
253 {
254 	/* Note that it is safe to use a single packet across all CPUs since
255 	 * two tasklets of the same type are guaranteed to not ever run
256 	 * simultaneously. If that ever changes, or VMCI stops using tasklets,
257 	 * we can use per-cpu packets.
258 	 */
259 	static struct vmci_transport_packet pkt;
260 
261 	return __vmci_transport_send_control_pkt(&pkt, src, dst, type,
262 						 size, mode, wait,
263 						 VSOCK_PROTO_INVALID, handle,
264 						 false);
265 }
266 
267 static int
268 vmci_transport_send_control_pkt(struct sock *sk,
269 				enum vmci_transport_packet_type type,
270 				u64 size,
271 				u64 mode,
272 				struct vmci_transport_waiting_info *wait,
273 				u16 proto,
274 				struct vmci_handle handle)
275 {
276 	struct vmci_transport_packet *pkt;
277 	struct vsock_sock *vsk;
278 	int err;
279 
280 	vsk = vsock_sk(sk);
281 
282 	if (!vsock_addr_bound(&vsk->local_addr))
283 		return -EINVAL;
284 
285 	if (!vsock_addr_bound(&vsk->remote_addr))
286 		return -EINVAL;
287 
288 	pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
289 	if (!pkt)
290 		return -ENOMEM;
291 
292 	err = __vmci_transport_send_control_pkt(pkt, &vsk->local_addr,
293 						&vsk->remote_addr, type, size,
294 						mode, wait, proto, handle,
295 						true);
296 	kfree(pkt);
297 
298 	return err;
299 }
300 
301 static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
302 					struct sockaddr_vm *src,
303 					struct vmci_transport_packet *pkt)
304 {
305 	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
306 		return 0;
307 	return vmci_transport_send_control_pkt_bh(
308 					dst, src,
309 					VMCI_TRANSPORT_PACKET_TYPE_RST, 0,
310 					0, NULL, VMCI_INVALID_HANDLE);
311 }
312 
313 static int vmci_transport_send_reset(struct sock *sk,
314 				     struct vmci_transport_packet *pkt)
315 {
316 	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
317 		return 0;
318 	return vmci_transport_send_control_pkt(sk,
319 					VMCI_TRANSPORT_PACKET_TYPE_RST,
320 					0, 0, NULL, VSOCK_PROTO_INVALID,
321 					VMCI_INVALID_HANDLE);
322 }
323 
324 static int vmci_transport_send_negotiate(struct sock *sk, size_t size)
325 {
326 	return vmci_transport_send_control_pkt(
327 					sk,
328 					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE,
329 					size, 0, NULL,
330 					VSOCK_PROTO_INVALID,
331 					VMCI_INVALID_HANDLE);
332 }
333 
334 static int vmci_transport_send_negotiate2(struct sock *sk, size_t size,
335 					  u16 version)
336 {
337 	return vmci_transport_send_control_pkt(
338 					sk,
339 					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2,
340 					size, 0, NULL, version,
341 					VMCI_INVALID_HANDLE);
342 }
343 
344 static int vmci_transport_send_qp_offer(struct sock *sk,
345 					struct vmci_handle handle)
346 {
347 	return vmci_transport_send_control_pkt(
348 					sk, VMCI_TRANSPORT_PACKET_TYPE_OFFER, 0,
349 					0, NULL,
350 					VSOCK_PROTO_INVALID, handle);
351 }
352 
353 static int vmci_transport_send_attach(struct sock *sk,
354 				      struct vmci_handle handle)
355 {
356 	return vmci_transport_send_control_pkt(
357 					sk, VMCI_TRANSPORT_PACKET_TYPE_ATTACH,
358 					0, 0, NULL, VSOCK_PROTO_INVALID,
359 					handle);
360 }
361 
362 static int vmci_transport_reply_reset(struct vmci_transport_packet *pkt)
363 {
364 	return vmci_transport_reply_control_pkt_fast(
365 						pkt,
366 						VMCI_TRANSPORT_PACKET_TYPE_RST,
367 						0, 0, NULL,
368 						VMCI_INVALID_HANDLE);
369 }
370 
371 static int vmci_transport_send_invalid_bh(struct sockaddr_vm *dst,
372 					  struct sockaddr_vm *src)
373 {
374 	return vmci_transport_send_control_pkt_bh(
375 					dst, src,
376 					VMCI_TRANSPORT_PACKET_TYPE_INVALID,
377 					0, 0, NULL, VMCI_INVALID_HANDLE);
378 }
379 
380 int vmci_transport_send_wrote_bh(struct sockaddr_vm *dst,
381 				 struct sockaddr_vm *src)
382 {
383 	return vmci_transport_send_control_pkt_bh(
384 					dst, src,
385 					VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
386 					0, NULL, VMCI_INVALID_HANDLE);
387 }
388 
389 int vmci_transport_send_read_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_READ, 0,
395 					0, NULL, VMCI_INVALID_HANDLE);
396 }
397 
398 int vmci_transport_send_wrote(struct sock *sk)
399 {
400 	return vmci_transport_send_control_pkt(
401 					sk, VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
402 					0, NULL, VSOCK_PROTO_INVALID,
403 					VMCI_INVALID_HANDLE);
404 }
405 
406 int vmci_transport_send_read(struct sock *sk)
407 {
408 	return vmci_transport_send_control_pkt(
409 					sk, VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
410 					0, NULL, VSOCK_PROTO_INVALID,
411 					VMCI_INVALID_HANDLE);
412 }
413 
414 int vmci_transport_send_waiting_write(struct sock *sk,
415 				      struct vmci_transport_waiting_info *wait)
416 {
417 	return vmci_transport_send_control_pkt(
418 				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE,
419 				0, 0, wait, VSOCK_PROTO_INVALID,
420 				VMCI_INVALID_HANDLE);
421 }
422 
423 int vmci_transport_send_waiting_read(struct sock *sk,
424 				     struct vmci_transport_waiting_info *wait)
425 {
426 	return vmci_transport_send_control_pkt(
427 				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ,
428 				0, 0, wait, VSOCK_PROTO_INVALID,
429 				VMCI_INVALID_HANDLE);
430 }
431 
432 static int vmci_transport_shutdown(struct vsock_sock *vsk, int mode)
433 {
434 	return vmci_transport_send_control_pkt(
435 					&vsk->sk,
436 					VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN,
437 					0, mode, NULL,
438 					VSOCK_PROTO_INVALID,
439 					VMCI_INVALID_HANDLE);
440 }
441 
442 static int vmci_transport_send_conn_request(struct sock *sk, size_t size)
443 {
444 	return vmci_transport_send_control_pkt(sk,
445 					VMCI_TRANSPORT_PACKET_TYPE_REQUEST,
446 					size, 0, NULL,
447 					VSOCK_PROTO_INVALID,
448 					VMCI_INVALID_HANDLE);
449 }
450 
451 static int vmci_transport_send_conn_request2(struct sock *sk, size_t size,
452 					     u16 version)
453 {
454 	return vmci_transport_send_control_pkt(
455 					sk, VMCI_TRANSPORT_PACKET_TYPE_REQUEST2,
456 					size, 0, NULL, version,
457 					VMCI_INVALID_HANDLE);
458 }
459 
460 static struct sock *vmci_transport_get_pending(
461 					struct sock *listener,
462 					struct vmci_transport_packet *pkt)
463 {
464 	struct vsock_sock *vlistener;
465 	struct vsock_sock *vpending;
466 	struct sock *pending;
467 
468 	vlistener = vsock_sk(listener);
469 
470 	list_for_each_entry(vpending, &vlistener->pending_links,
471 			    pending_links) {
472 		struct sockaddr_vm src;
473 		struct sockaddr_vm dst;
474 
475 		vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
476 		vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);
477 
478 		if (vsock_addr_equals_addr(&src, &vpending->remote_addr) &&
479 		    vsock_addr_equals_addr(&dst, &vpending->local_addr)) {
480 			pending = sk_vsock(vpending);
481 			sock_hold(pending);
482 			goto found;
483 		}
484 	}
485 
486 	pending = NULL;
487 found:
488 	return pending;
489 
490 }
491 
492 static void vmci_transport_release_pending(struct sock *pending)
493 {
494 	sock_put(pending);
495 }
496 
497 /* We allow two kinds of sockets to communicate with a restricted VM: 1)
498  * trusted sockets 2) sockets from applications running as the same user as the
499  * VM (this is only true for the host side and only when using hosted products)
500  */
501 
502 static bool vmci_transport_is_trusted(struct vsock_sock *vsock, u32 peer_cid)
503 {
504 	return vsock->trusted ||
505 	       vmci_is_context_owner(peer_cid, vsock->owner->uid);
506 }
507 
508 /* We allow sending datagrams to and receiving datagrams from a restricted VM
509  * only if it is trusted as described in vmci_transport_is_trusted.
510  */
511 
512 static bool vmci_transport_allow_dgram(struct vsock_sock *vsock, u32 peer_cid)
513 {
514 	if (vsock->cached_peer != peer_cid) {
515 		vsock->cached_peer = peer_cid;
516 		if (!vmci_transport_is_trusted(vsock, peer_cid) &&
517 		    (vmci_context_get_priv_flags(peer_cid) &
518 		     VMCI_PRIVILEGE_FLAG_RESTRICTED)) {
519 			vsock->cached_peer_allow_dgram = false;
520 		} else {
521 			vsock->cached_peer_allow_dgram = true;
522 		}
523 	}
524 
525 	return vsock->cached_peer_allow_dgram;
526 }
527 
528 static int
529 vmci_transport_queue_pair_alloc(struct vmci_qp **qpair,
530 				struct vmci_handle *handle,
531 				u64 produce_size,
532 				u64 consume_size,
533 				u32 peer, u32 flags, bool trusted)
534 {
535 	int err = 0;
536 
537 	if (trusted) {
538 		/* Try to allocate our queue pair as trusted. This will only
539 		 * work if vsock is running in the host.
540 		 */
541 
542 		err = vmci_qpair_alloc(qpair, handle, produce_size,
543 				       consume_size,
544 				       peer, flags,
545 				       VMCI_PRIVILEGE_FLAG_TRUSTED);
546 		if (err != VMCI_ERROR_NO_ACCESS)
547 			goto out;
548 
549 	}
550 
551 	err = vmci_qpair_alloc(qpair, handle, produce_size, consume_size,
552 			       peer, flags, VMCI_NO_PRIVILEGE_FLAGS);
553 out:
554 	if (err < 0) {
555 		pr_err("Could not attach to queue pair with %d\n",
556 		       err);
557 		err = vmci_transport_error_to_vsock_error(err);
558 	}
559 
560 	return err;
561 }
562 
563 static int
564 vmci_transport_datagram_create_hnd(u32 resource_id,
565 				   u32 flags,
566 				   vmci_datagram_recv_cb recv_cb,
567 				   void *client_data,
568 				   struct vmci_handle *out_handle)
569 {
570 	int err = 0;
571 
572 	/* Try to allocate our datagram handler as trusted. This will only work
573 	 * if vsock is running in the host.
574 	 */
575 
576 	err = vmci_datagram_create_handle_priv(resource_id, flags,
577 					       VMCI_PRIVILEGE_FLAG_TRUSTED,
578 					       recv_cb,
579 					       client_data, out_handle);
580 
581 	if (err == VMCI_ERROR_NO_ACCESS)
582 		err = vmci_datagram_create_handle(resource_id, flags,
583 						  recv_cb, client_data,
584 						  out_handle);
585 
586 	return err;
587 }
588 
589 /* This is invoked as part of a tasklet that's scheduled when the VMCI
590  * interrupt fires.  This is run in bottom-half context and if it ever needs to
591  * sleep it should defer that work to a work queue.
592  */
593 
594 static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
595 {
596 	struct sock *sk;
597 	size_t size;
598 	struct sk_buff *skb;
599 	struct vsock_sock *vsk;
600 
601 	sk = (struct sock *)data;
602 
603 	/* This handler is privileged when this module is running on the host.
604 	 * We will get datagrams from all endpoints (even VMs that are in a
605 	 * restricted context). If we get one from a restricted context then
606 	 * the destination socket must be trusted.
607 	 *
608 	 * NOTE: We access the socket struct without holding the lock here.
609 	 * This is ok because the field we are interested is never modified
610 	 * outside of the create and destruct socket functions.
611 	 */
612 	vsk = vsock_sk(sk);
613 	if (!vmci_transport_allow_dgram(vsk, dg->src.context))
614 		return VMCI_ERROR_NO_ACCESS;
615 
616 	size = VMCI_DG_SIZE(dg);
617 
618 	/* Attach the packet to the socket's receive queue as an sk_buff. */
619 	skb = alloc_skb(size, GFP_ATOMIC);
620 	if (skb) {
621 		/* sk_receive_skb() will do a sock_put(), so hold here. */
622 		sock_hold(sk);
623 		skb_put(skb, size);
624 		memcpy(skb->data, dg, size);
625 		sk_receive_skb(sk, skb, 0);
626 	}
627 
628 	return VMCI_SUCCESS;
629 }
630 
631 static bool vmci_transport_stream_allow(u32 cid, u32 port)
632 {
633 	static const u32 non_socket_contexts[] = {
634 		VMADDR_CID_HYPERVISOR,
635 		VMADDR_CID_RESERVED,
636 	};
637 	int i;
638 
639 	BUILD_BUG_ON(sizeof(cid) != sizeof(*non_socket_contexts));
640 
641 	for (i = 0; i < ARRAY_SIZE(non_socket_contexts); i++) {
642 		if (cid == non_socket_contexts[i])
643 			return false;
644 	}
645 
646 	return true;
647 }
648 
649 /* This is invoked as part of a tasklet that's scheduled when the VMCI
650  * interrupt fires.  This is run in bottom-half context but it defers most of
651  * its work to the packet handling work queue.
652  */
653 
654 static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
655 {
656 	struct sock *sk;
657 	struct sockaddr_vm dst;
658 	struct sockaddr_vm src;
659 	struct vmci_transport_packet *pkt;
660 	struct vsock_sock *vsk;
661 	bool bh_process_pkt;
662 	int err;
663 
664 	sk = NULL;
665 	err = VMCI_SUCCESS;
666 	bh_process_pkt = false;
667 
668 	/* Ignore incoming packets from contexts without sockets, or resources
669 	 * that aren't vsock implementations.
670 	 */
671 
672 	if (!vmci_transport_stream_allow(dg->src.context, -1)
673 	    || VMCI_TRANSPORT_PACKET_RID != dg->src.resource)
674 		return VMCI_ERROR_NO_ACCESS;
675 
676 	if (VMCI_DG_SIZE(dg) < sizeof(*pkt))
677 		/* Drop datagrams that do not contain full VSock packets. */
678 		return VMCI_ERROR_INVALID_ARGS;
679 
680 	pkt = (struct vmci_transport_packet *)dg;
681 
682 	/* Find the socket that should handle this packet.  First we look for a
683 	 * connected socket and if there is none we look for a socket bound to
684 	 * the destintation address.
685 	 */
686 	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
687 	vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);
688 
689 	sk = vsock_find_connected_socket(&src, &dst);
690 	if (!sk) {
691 		sk = vsock_find_bound_socket(&dst);
692 		if (!sk) {
693 			/* We could not find a socket for this specified
694 			 * address.  If this packet is a RST, we just drop it.
695 			 * If it is another packet, we send a RST.  Note that
696 			 * we do not send a RST reply to RSTs so that we do not
697 			 * continually send RSTs between two endpoints.
698 			 *
699 			 * Note that since this is a reply, dst is src and src
700 			 * is dst.
701 			 */
702 			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
703 				pr_err("unable to send reset\n");
704 
705 			err = VMCI_ERROR_NOT_FOUND;
706 			goto out;
707 		}
708 	}
709 
710 	/* If the received packet type is beyond all types known to this
711 	 * implementation, reply with an invalid message.  Hopefully this will
712 	 * help when implementing backwards compatibility in the future.
713 	 */
714 	if (pkt->type >= VMCI_TRANSPORT_PACKET_TYPE_MAX) {
715 		vmci_transport_send_invalid_bh(&dst, &src);
716 		err = VMCI_ERROR_INVALID_ARGS;
717 		goto out;
718 	}
719 
720 	/* This handler is privileged when this module is running on the host.
721 	 * We will get datagram connect requests from all endpoints (even VMs
722 	 * that are in a restricted context). If we get one from a restricted
723 	 * context then the destination socket must be trusted.
724 	 *
725 	 * NOTE: We access the socket struct without holding the lock here.
726 	 * This is ok because the field we are interested is never modified
727 	 * outside of the create and destruct socket functions.
728 	 */
729 	vsk = vsock_sk(sk);
730 	if (!vmci_transport_allow_dgram(vsk, pkt->dg.src.context)) {
731 		err = VMCI_ERROR_NO_ACCESS;
732 		goto out;
733 	}
734 
735 	/* We do most everything in a work queue, but let's fast path the
736 	 * notification of reads and writes to help data transfer performance.
737 	 * We can only do this if there is no process context code executing
738 	 * for this socket since that may change the state.
739 	 */
740 	bh_lock_sock(sk);
741 
742 	if (!sock_owned_by_user(sk) && sk->sk_state == SS_CONNECTED)
743 		vmci_trans(vsk)->notify_ops->handle_notify_pkt(
744 				sk, pkt, true, &dst, &src,
745 				&bh_process_pkt);
746 
747 	bh_unlock_sock(sk);
748 
749 	if (!bh_process_pkt) {
750 		struct vmci_transport_recv_pkt_info *recv_pkt_info;
751 
752 		recv_pkt_info = kmalloc(sizeof(*recv_pkt_info), GFP_ATOMIC);
753 		if (!recv_pkt_info) {
754 			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
755 				pr_err("unable to send reset\n");
756 
757 			err = VMCI_ERROR_NO_MEM;
758 			goto out;
759 		}
760 
761 		recv_pkt_info->sk = sk;
762 		memcpy(&recv_pkt_info->pkt, pkt, sizeof(recv_pkt_info->pkt));
763 		INIT_WORK(&recv_pkt_info->work, vmci_transport_recv_pkt_work);
764 
765 		schedule_work(&recv_pkt_info->work);
766 		/* Clear sk so that the reference count incremented by one of
767 		 * the Find functions above is not decremented below.  We need
768 		 * that reference count for the packet handler we've scheduled
769 		 * to run.
770 		 */
771 		sk = NULL;
772 	}
773 
774 out:
775 	if (sk)
776 		sock_put(sk);
777 
778 	return err;
779 }
780 
781 static void vmci_transport_peer_attach_cb(u32 sub_id,
782 					  const struct vmci_event_data *e_data,
783 					  void *client_data)
784 {
785 	struct sock *sk = client_data;
786 	const struct vmci_event_payload_qp *e_payload;
787 	struct vsock_sock *vsk;
788 
789 	e_payload = vmci_event_data_const_payload(e_data);
790 
791 	vsk = vsock_sk(sk);
792 
793 	/* We don't ask for delayed CBs when we subscribe to this event (we
794 	 * pass 0 as flags to vmci_event_subscribe()).  VMCI makes no
795 	 * guarantees in that case about what context we might be running in,
796 	 * so it could be BH or process, blockable or non-blockable.  So we
797 	 * need to account for all possible contexts here.
798 	 */
799 	local_bh_disable();
800 	bh_lock_sock(sk);
801 
802 	/* XXX This is lame, we should provide a way to lookup sockets by
803 	 * qp_handle.
804 	 */
805 	if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
806 				 e_payload->handle)) {
807 		/* XXX This doesn't do anything, but in the future we may want
808 		 * to set a flag here to verify the attach really did occur and
809 		 * we weren't just sent a datagram claiming it was.
810 		 */
811 		goto out;
812 	}
813 
814 out:
815 	bh_unlock_sock(sk);
816 	local_bh_enable();
817 }
818 
819 static void vmci_transport_handle_detach(struct sock *sk)
820 {
821 	struct vsock_sock *vsk;
822 
823 	vsk = vsock_sk(sk);
824 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
825 		sock_set_flag(sk, SOCK_DONE);
826 
827 		/* On a detach the peer will not be sending or receiving
828 		 * anymore.
829 		 */
830 		vsk->peer_shutdown = SHUTDOWN_MASK;
831 
832 		/* We should not be sending anymore since the peer won't be
833 		 * there to receive, but we can still receive if there is data
834 		 * left in our consume queue.
835 		 */
836 		if (vsock_stream_has_data(vsk) <= 0) {
837 			if (sk->sk_state == SS_CONNECTING) {
838 				/* The peer may detach from a queue pair while
839 				 * we are still in the connecting state, i.e.,
840 				 * if the peer VM is killed after attaching to
841 				 * a queue pair, but before we complete the
842 				 * handshake. In that case, we treat the detach
843 				 * event like a reset.
844 				 */
845 
846 				sk->sk_state = SS_UNCONNECTED;
847 				sk->sk_err = ECONNRESET;
848 				sk->sk_error_report(sk);
849 				return;
850 			}
851 			sk->sk_state = SS_UNCONNECTED;
852 		}
853 		sk->sk_state_change(sk);
854 	}
855 }
856 
857 static void vmci_transport_peer_detach_cb(u32 sub_id,
858 					  const struct vmci_event_data *e_data,
859 					  void *client_data)
860 {
861 	struct sock *sk = client_data;
862 	const struct vmci_event_payload_qp *e_payload;
863 	struct vsock_sock *vsk;
864 
865 	e_payload = vmci_event_data_const_payload(e_data);
866 	vsk = vsock_sk(sk);
867 	if (vmci_handle_is_invalid(e_payload->handle))
868 		return;
869 
870 	/* Same rules for locking as for peer_attach_cb(). */
871 	local_bh_disable();
872 	bh_lock_sock(sk);
873 
874 	/* XXX This is lame, we should provide a way to lookup sockets by
875 	 * qp_handle.
876 	 */
877 	if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
878 				 e_payload->handle))
879 		vmci_transport_handle_detach(sk);
880 
881 	bh_unlock_sock(sk);
882 	local_bh_enable();
883 }
884 
885 static void vmci_transport_qp_resumed_cb(u32 sub_id,
886 					 const struct vmci_event_data *e_data,
887 					 void *client_data)
888 {
889 	vsock_for_each_connected_socket(vmci_transport_handle_detach);
890 }
891 
892 static void vmci_transport_recv_pkt_work(struct work_struct *work)
893 {
894 	struct vmci_transport_recv_pkt_info *recv_pkt_info;
895 	struct vmci_transport_packet *pkt;
896 	struct sock *sk;
897 
898 	recv_pkt_info =
899 		container_of(work, struct vmci_transport_recv_pkt_info, work);
900 	sk = recv_pkt_info->sk;
901 	pkt = &recv_pkt_info->pkt;
902 
903 	lock_sock(sk);
904 
905 	switch (sk->sk_state) {
906 	case SS_LISTEN:
907 		vmci_transport_recv_listen(sk, pkt);
908 		break;
909 	case SS_CONNECTING:
910 		/* Processing of pending connections for servers goes through
911 		 * the listening socket, so see vmci_transport_recv_listen()
912 		 * for that path.
913 		 */
914 		vmci_transport_recv_connecting_client(sk, pkt);
915 		break;
916 	case SS_CONNECTED:
917 		vmci_transport_recv_connected(sk, pkt);
918 		break;
919 	default:
920 		/* Because this function does not run in the same context as
921 		 * vmci_transport_recv_stream_cb it is possible that the
922 		 * socket has closed. We need to let the other side know or it
923 		 * could be sitting in a connect and hang forever. Send a
924 		 * reset to prevent that.
925 		 */
926 		vmci_transport_send_reset(sk, pkt);
927 		goto out;
928 	}
929 
930 out:
931 	release_sock(sk);
932 	kfree(recv_pkt_info);
933 	/* Release reference obtained in the stream callback when we fetched
934 	 * this socket out of the bound or connected list.
935 	 */
936 	sock_put(sk);
937 }
938 
939 static int vmci_transport_recv_listen(struct sock *sk,
940 				      struct vmci_transport_packet *pkt)
941 {
942 	struct sock *pending;
943 	struct vsock_sock *vpending;
944 	int err;
945 	u64 qp_size;
946 	bool old_request = false;
947 	bool old_pkt_proto = false;
948 
949 	err = 0;
950 
951 	/* Because we are in the listen state, we could be receiving a packet
952 	 * for ourself or any previous connection requests that we received.
953 	 * If it's the latter, we try to find a socket in our list of pending
954 	 * connections and, if we do, call the appropriate handler for the
955 	 * state that that socket is in.  Otherwise we try to service the
956 	 * connection request.
957 	 */
958 	pending = vmci_transport_get_pending(sk, pkt);
959 	if (pending) {
960 		lock_sock(pending);
961 		switch (pending->sk_state) {
962 		case SS_CONNECTING:
963 			err = vmci_transport_recv_connecting_server(sk,
964 								    pending,
965 								    pkt);
966 			break;
967 		default:
968 			vmci_transport_send_reset(pending, pkt);
969 			err = -EINVAL;
970 		}
971 
972 		if (err < 0)
973 			vsock_remove_pending(sk, pending);
974 
975 		release_sock(pending);
976 		vmci_transport_release_pending(pending);
977 
978 		return err;
979 	}
980 
981 	/* The listen state only accepts connection requests.  Reply with a
982 	 * reset unless we received a reset.
983 	 */
984 
985 	if (!(pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST ||
986 	      pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)) {
987 		vmci_transport_reply_reset(pkt);
988 		return -EINVAL;
989 	}
990 
991 	if (pkt->u.size == 0) {
992 		vmci_transport_reply_reset(pkt);
993 		return -EINVAL;
994 	}
995 
996 	/* If this socket can't accommodate this connection request, we send a
997 	 * reset.  Otherwise we create and initialize a child socket and reply
998 	 * with a connection negotiation.
999 	 */
1000 	if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) {
1001 		vmci_transport_reply_reset(pkt);
1002 		return -ECONNREFUSED;
1003 	}
1004 
1005 	pending = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
1006 				 sk->sk_type);
1007 	if (!pending) {
1008 		vmci_transport_send_reset(sk, pkt);
1009 		return -ENOMEM;
1010 	}
1011 
1012 	vpending = vsock_sk(pending);
1013 
1014 	vsock_addr_init(&vpending->local_addr, pkt->dg.dst.context,
1015 			pkt->dst_port);
1016 	vsock_addr_init(&vpending->remote_addr, pkt->dg.src.context,
1017 			pkt->src_port);
1018 
1019 	/* If the proposed size fits within our min/max, accept it. Otherwise
1020 	 * propose our own size.
1021 	 */
1022 	if (pkt->u.size >= vmci_trans(vpending)->queue_pair_min_size &&
1023 	    pkt->u.size <= vmci_trans(vpending)->queue_pair_max_size) {
1024 		qp_size = pkt->u.size;
1025 	} else {
1026 		qp_size = vmci_trans(vpending)->queue_pair_size;
1027 	}
1028 
1029 	/* Figure out if we are using old or new requests based on the
1030 	 * overrides pkt types sent by our peer.
1031 	 */
1032 	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
1033 		old_request = old_pkt_proto;
1034 	} else {
1035 		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST)
1036 			old_request = true;
1037 		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)
1038 			old_request = false;
1039 
1040 	}
1041 
1042 	if (old_request) {
1043 		/* Handle a REQUEST (or override) */
1044 		u16 version = VSOCK_PROTO_INVALID;
1045 		if (vmci_transport_proto_to_notify_struct(
1046 			pending, &version, true))
1047 			err = vmci_transport_send_negotiate(pending, qp_size);
1048 		else
1049 			err = -EINVAL;
1050 
1051 	} else {
1052 		/* Handle a REQUEST2 (or override) */
1053 		int proto_int = pkt->proto;
1054 		int pos;
1055 		u16 active_proto_version = 0;
1056 
1057 		/* The list of possible protocols is the intersection of all
1058 		 * protocols the client supports ... plus all the protocols we
1059 		 * support.
1060 		 */
1061 		proto_int &= vmci_transport_new_proto_supported_versions();
1062 
1063 		/* We choose the highest possible protocol version and use that
1064 		 * one.
1065 		 */
1066 		pos = fls(proto_int);
1067 		if (pos) {
1068 			active_proto_version = (1 << (pos - 1));
1069 			if (vmci_transport_proto_to_notify_struct(
1070 				pending, &active_proto_version, false))
1071 				err = vmci_transport_send_negotiate2(pending,
1072 							qp_size,
1073 							active_proto_version);
1074 			else
1075 				err = -EINVAL;
1076 
1077 		} else {
1078 			err = -EINVAL;
1079 		}
1080 	}
1081 
1082 	if (err < 0) {
1083 		vmci_transport_send_reset(sk, pkt);
1084 		sock_put(pending);
1085 		err = vmci_transport_error_to_vsock_error(err);
1086 		goto out;
1087 	}
1088 
1089 	vsock_add_pending(sk, pending);
1090 	sk->sk_ack_backlog++;
1091 
1092 	pending->sk_state = SS_CONNECTING;
1093 	vmci_trans(vpending)->produce_size =
1094 		vmci_trans(vpending)->consume_size = qp_size;
1095 	vmci_trans(vpending)->queue_pair_size = qp_size;
1096 
1097 	vmci_trans(vpending)->notify_ops->process_request(pending);
1098 
1099 	/* We might never receive another message for this socket and it's not
1100 	 * connected to any process, so we have to ensure it gets cleaned up
1101 	 * ourself.  Our delayed work function will take care of that.  Note
1102 	 * that we do not ever cancel this function since we have few
1103 	 * guarantees about its state when calling cancel_delayed_work().
1104 	 * Instead we hold a reference on the socket for that function and make
1105 	 * it capable of handling cases where it needs to do nothing but
1106 	 * release that reference.
1107 	 */
1108 	vpending->listener = sk;
1109 	sock_hold(sk);
1110 	sock_hold(pending);
1111 	INIT_DELAYED_WORK(&vpending->dwork, vsock_pending_work);
1112 	schedule_delayed_work(&vpending->dwork, HZ);
1113 
1114 out:
1115 	return err;
1116 }
1117 
1118 static int
1119 vmci_transport_recv_connecting_server(struct sock *listener,
1120 				      struct sock *pending,
1121 				      struct vmci_transport_packet *pkt)
1122 {
1123 	struct vsock_sock *vpending;
1124 	struct vmci_handle handle;
1125 	struct vmci_qp *qpair;
1126 	bool is_local;
1127 	u32 flags;
1128 	u32 detach_sub_id;
1129 	int err;
1130 	int skerr;
1131 
1132 	vpending = vsock_sk(pending);
1133 	detach_sub_id = VMCI_INVALID_ID;
1134 
1135 	switch (pkt->type) {
1136 	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
1137 		if (vmci_handle_is_invalid(pkt->u.handle)) {
1138 			vmci_transport_send_reset(pending, pkt);
1139 			skerr = EPROTO;
1140 			err = -EINVAL;
1141 			goto destroy;
1142 		}
1143 		break;
1144 	default:
1145 		/* Close and cleanup the connection. */
1146 		vmci_transport_send_reset(pending, pkt);
1147 		skerr = EPROTO;
1148 		err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;
1149 		goto destroy;
1150 	}
1151 
1152 	/* In order to complete the connection we need to attach to the offered
1153 	 * queue pair and send an attach notification.  We also subscribe to the
1154 	 * detach event so we know when our peer goes away, and we do that
1155 	 * before attaching so we don't miss an event.  If all this succeeds,
1156 	 * we update our state and wakeup anything waiting in accept() for a
1157 	 * connection.
1158 	 */
1159 
1160 	/* We don't care about attach since we ensure the other side has
1161 	 * attached by specifying the ATTACH_ONLY flag below.
1162 	 */
1163 	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
1164 				   vmci_transport_peer_detach_cb,
1165 				   pending, &detach_sub_id);
1166 	if (err < VMCI_SUCCESS) {
1167 		vmci_transport_send_reset(pending, pkt);
1168 		err = vmci_transport_error_to_vsock_error(err);
1169 		skerr = -err;
1170 		goto destroy;
1171 	}
1172 
1173 	vmci_trans(vpending)->detach_sub_id = detach_sub_id;
1174 
1175 	/* Now attach to the queue pair the client created. */
1176 	handle = pkt->u.handle;
1177 
1178 	/* vpending->local_addr always has a context id so we do not need to
1179 	 * worry about VMADDR_CID_ANY in this case.
1180 	 */
1181 	is_local =
1182 	    vpending->remote_addr.svm_cid == vpending->local_addr.svm_cid;
1183 	flags = VMCI_QPFLAG_ATTACH_ONLY;
1184 	flags |= is_local ? VMCI_QPFLAG_LOCAL : 0;
1185 
1186 	err = vmci_transport_queue_pair_alloc(
1187 					&qpair,
1188 					&handle,
1189 					vmci_trans(vpending)->produce_size,
1190 					vmci_trans(vpending)->consume_size,
1191 					pkt->dg.src.context,
1192 					flags,
1193 					vmci_transport_is_trusted(
1194 						vpending,
1195 						vpending->remote_addr.svm_cid));
1196 	if (err < 0) {
1197 		vmci_transport_send_reset(pending, pkt);
1198 		skerr = -err;
1199 		goto destroy;
1200 	}
1201 
1202 	vmci_trans(vpending)->qp_handle = handle;
1203 	vmci_trans(vpending)->qpair = qpair;
1204 
1205 	/* When we send the attach message, we must be ready to handle incoming
1206 	 * control messages on the newly connected socket. So we move the
1207 	 * pending socket to the connected state before sending the attach
1208 	 * message. Otherwise, an incoming packet triggered by the attach being
1209 	 * received by the peer may be processed concurrently with what happens
1210 	 * below after sending the attach message, and that incoming packet
1211 	 * will find the listening socket instead of the (currently) pending
1212 	 * socket. Note that enqueueing the socket increments the reference
1213 	 * count, so even if a reset comes before the connection is accepted,
1214 	 * the socket will be valid until it is removed from the queue.
1215 	 *
1216 	 * If we fail sending the attach below, we remove the socket from the
1217 	 * connected list and move the socket to SS_UNCONNECTED before
1218 	 * releasing the lock, so a pending slow path processing of an incoming
1219 	 * packet will not see the socket in the connected state in that case.
1220 	 */
1221 	pending->sk_state = SS_CONNECTED;
1222 
1223 	vsock_insert_connected(vpending);
1224 
1225 	/* Notify our peer of our attach. */
1226 	err = vmci_transport_send_attach(pending, handle);
1227 	if (err < 0) {
1228 		vsock_remove_connected(vpending);
1229 		pr_err("Could not send attach\n");
1230 		vmci_transport_send_reset(pending, pkt);
1231 		err = vmci_transport_error_to_vsock_error(err);
1232 		skerr = -err;
1233 		goto destroy;
1234 	}
1235 
1236 	/* We have a connection. Move the now connected socket from the
1237 	 * listener's pending list to the accept queue so callers of accept()
1238 	 * can find it.
1239 	 */
1240 	vsock_remove_pending(listener, pending);
1241 	vsock_enqueue_accept(listener, pending);
1242 
1243 	/* Callers of accept() will be be waiting on the listening socket, not
1244 	 * the pending socket.
1245 	 */
1246 	listener->sk_state_change(listener);
1247 
1248 	return 0;
1249 
1250 destroy:
1251 	pending->sk_err = skerr;
1252 	pending->sk_state = SS_UNCONNECTED;
1253 	/* As long as we drop our reference, all necessary cleanup will handle
1254 	 * when the cleanup function drops its reference and our destruct
1255 	 * implementation is called.  Note that since the listen handler will
1256 	 * remove pending from the pending list upon our failure, the cleanup
1257 	 * function won't drop the additional reference, which is why we do it
1258 	 * here.
1259 	 */
1260 	sock_put(pending);
1261 
1262 	return err;
1263 }
1264 
1265 static int
1266 vmci_transport_recv_connecting_client(struct sock *sk,
1267 				      struct vmci_transport_packet *pkt)
1268 {
1269 	struct vsock_sock *vsk;
1270 	int err;
1271 	int skerr;
1272 
1273 	vsk = vsock_sk(sk);
1274 
1275 	switch (pkt->type) {
1276 	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
1277 		if (vmci_handle_is_invalid(pkt->u.handle) ||
1278 		    !vmci_handle_is_equal(pkt->u.handle,
1279 					  vmci_trans(vsk)->qp_handle)) {
1280 			skerr = EPROTO;
1281 			err = -EINVAL;
1282 			goto destroy;
1283 		}
1284 
1285 		/* Signify the socket is connected and wakeup the waiter in
1286 		 * connect(). Also place the socket in the connected table for
1287 		 * accounting (it can already be found since it's in the bound
1288 		 * table).
1289 		 */
1290 		sk->sk_state = SS_CONNECTED;
1291 		sk->sk_socket->state = SS_CONNECTED;
1292 		vsock_insert_connected(vsk);
1293 		sk->sk_state_change(sk);
1294 
1295 		break;
1296 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
1297 	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
1298 		if (pkt->u.size == 0
1299 		    || pkt->dg.src.context != vsk->remote_addr.svm_cid
1300 		    || pkt->src_port != vsk->remote_addr.svm_port
1301 		    || !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)
1302 		    || vmci_trans(vsk)->qpair
1303 		    || vmci_trans(vsk)->produce_size != 0
1304 		    || vmci_trans(vsk)->consume_size != 0
1305 		    || vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID
1306 		    || vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
1307 			skerr = EPROTO;
1308 			err = -EINVAL;
1309 
1310 			goto destroy;
1311 		}
1312 
1313 		err = vmci_transport_recv_connecting_client_negotiate(sk, pkt);
1314 		if (err) {
1315 			skerr = -err;
1316 			goto destroy;
1317 		}
1318 
1319 		break;
1320 	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
1321 		err = vmci_transport_recv_connecting_client_invalid(sk, pkt);
1322 		if (err) {
1323 			skerr = -err;
1324 			goto destroy;
1325 		}
1326 
1327 		break;
1328 	case VMCI_TRANSPORT_PACKET_TYPE_RST:
1329 		/* Older versions of the linux code (WS 6.5 / ESX 4.0) used to
1330 		 * continue processing here after they sent an INVALID packet.
1331 		 * This meant that we got a RST after the INVALID. We ignore a
1332 		 * RST after an INVALID. The common code doesn't send the RST
1333 		 * ... so we can hang if an old version of the common code
1334 		 * fails between getting a REQUEST and sending an OFFER back.
1335 		 * Not much we can do about it... except hope that it doesn't
1336 		 * happen.
1337 		 */
1338 		if (vsk->ignore_connecting_rst) {
1339 			vsk->ignore_connecting_rst = false;
1340 		} else {
1341 			skerr = ECONNRESET;
1342 			err = 0;
1343 			goto destroy;
1344 		}
1345 
1346 		break;
1347 	default:
1348 		/* Close and cleanup the connection. */
1349 		skerr = EPROTO;
1350 		err = -EINVAL;
1351 		goto destroy;
1352 	}
1353 
1354 	return 0;
1355 
1356 destroy:
1357 	vmci_transport_send_reset(sk, pkt);
1358 
1359 	sk->sk_state = SS_UNCONNECTED;
1360 	sk->sk_err = skerr;
1361 	sk->sk_error_report(sk);
1362 	return err;
1363 }
1364 
1365 static int vmci_transport_recv_connecting_client_negotiate(
1366 					struct sock *sk,
1367 					struct vmci_transport_packet *pkt)
1368 {
1369 	int err;
1370 	struct vsock_sock *vsk;
1371 	struct vmci_handle handle;
1372 	struct vmci_qp *qpair;
1373 	u32 attach_sub_id;
1374 	u32 detach_sub_id;
1375 	bool is_local;
1376 	u32 flags;
1377 	bool old_proto = true;
1378 	bool old_pkt_proto;
1379 	u16 version;
1380 
1381 	vsk = vsock_sk(sk);
1382 	handle = VMCI_INVALID_HANDLE;
1383 	attach_sub_id = VMCI_INVALID_ID;
1384 	detach_sub_id = VMCI_INVALID_ID;
1385 
1386 	/* If we have gotten here then we should be past the point where old
1387 	 * linux vsock could have sent the bogus rst.
1388 	 */
1389 	vsk->sent_request = false;
1390 	vsk->ignore_connecting_rst = false;
1391 
1392 	/* Verify that we're OK with the proposed queue pair size */
1393 	if (pkt->u.size < vmci_trans(vsk)->queue_pair_min_size ||
1394 	    pkt->u.size > vmci_trans(vsk)->queue_pair_max_size) {
1395 		err = -EINVAL;
1396 		goto destroy;
1397 	}
1398 
1399 	/* At this point we know the CID the peer is using to talk to us. */
1400 
1401 	if (vsk->local_addr.svm_cid == VMADDR_CID_ANY)
1402 		vsk->local_addr.svm_cid = pkt->dg.dst.context;
1403 
1404 	/* Setup the notify ops to be the highest supported version that both
1405 	 * the server and the client support.
1406 	 */
1407 
1408 	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
1409 		old_proto = old_pkt_proto;
1410 	} else {
1411 		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE)
1412 			old_proto = true;
1413 		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2)
1414 			old_proto = false;
1415 
1416 	}
1417 
1418 	if (old_proto)
1419 		version = VSOCK_PROTO_INVALID;
1420 	else
1421 		version = pkt->proto;
1422 
1423 	if (!vmci_transport_proto_to_notify_struct(sk, &version, old_proto)) {
1424 		err = -EINVAL;
1425 		goto destroy;
1426 	}
1427 
1428 	/* Subscribe to attach and detach events first.
1429 	 *
1430 	 * XXX We attach once for each queue pair created for now so it is easy
1431 	 * to find the socket (it's provided), but later we should only
1432 	 * subscribe once and add a way to lookup sockets by queue pair handle.
1433 	 */
1434 	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_ATTACH,
1435 				   vmci_transport_peer_attach_cb,
1436 				   sk, &attach_sub_id);
1437 	if (err < VMCI_SUCCESS) {
1438 		err = vmci_transport_error_to_vsock_error(err);
1439 		goto destroy;
1440 	}
1441 
1442 	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
1443 				   vmci_transport_peer_detach_cb,
1444 				   sk, &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)->attach_sub_id = attach_sub_id;
1481 	vmci_trans(vsk)->detach_sub_id = detach_sub_id;
1482 
1483 	vmci_trans(vsk)->notify_ops->process_negotiate(sk);
1484 
1485 	return 0;
1486 
1487 destroy:
1488 	if (attach_sub_id != VMCI_INVALID_ID)
1489 		vmci_event_unsubscribe(attach_sub_id);
1490 
1491 	if (detach_sub_id != VMCI_INVALID_ID)
1492 		vmci_event_unsubscribe(detach_sub_id);
1493 
1494 	if (!vmci_handle_is_invalid(handle))
1495 		vmci_qpair_detach(&qpair);
1496 
1497 	return err;
1498 }
1499 
1500 static int
1501 vmci_transport_recv_connecting_client_invalid(struct sock *sk,
1502 					      struct vmci_transport_packet *pkt)
1503 {
1504 	int err = 0;
1505 	struct vsock_sock *vsk = vsock_sk(sk);
1506 
1507 	if (vsk->sent_request) {
1508 		vsk->sent_request = false;
1509 		vsk->ignore_connecting_rst = true;
1510 
1511 		err = vmci_transport_send_conn_request(
1512 			sk, vmci_trans(vsk)->queue_pair_size);
1513 		if (err < 0)
1514 			err = vmci_transport_error_to_vsock_error(err);
1515 		else
1516 			err = 0;
1517 
1518 	}
1519 
1520 	return err;
1521 }
1522 
1523 static int vmci_transport_recv_connected(struct sock *sk,
1524 					 struct vmci_transport_packet *pkt)
1525 {
1526 	struct vsock_sock *vsk;
1527 	bool pkt_processed = false;
1528 
1529 	/* In cases where we are closing the connection, it's sufficient to
1530 	 * mark the state change (and maybe error) and wake up any waiting
1531 	 * threads. Since this is a connected socket, it's owned by a user
1532 	 * process and will be cleaned up when the failure is passed back on
1533 	 * the current or next system call.  Our system call implementations
1534 	 * must therefore check for error and state changes on entry and when
1535 	 * being awoken.
1536 	 */
1537 	switch (pkt->type) {
1538 	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
1539 		if (pkt->u.mode) {
1540 			vsk = vsock_sk(sk);
1541 
1542 			vsk->peer_shutdown |= pkt->u.mode;
1543 			sk->sk_state_change(sk);
1544 		}
1545 		break;
1546 
1547 	case VMCI_TRANSPORT_PACKET_TYPE_RST:
1548 		vsk = vsock_sk(sk);
1549 		/* It is possible that we sent our peer a message (e.g a
1550 		 * WAITING_READ) right before we got notified that the peer had
1551 		 * detached. If that happens then we can get a RST pkt back
1552 		 * from our peer even though there is data available for us to
1553 		 * read. In that case, don't shutdown the socket completely but
1554 		 * instead allow the local client to finish reading data off
1555 		 * the queuepair. Always treat a RST pkt in connected mode like
1556 		 * a clean shutdown.
1557 		 */
1558 		sock_set_flag(sk, SOCK_DONE);
1559 		vsk->peer_shutdown = SHUTDOWN_MASK;
1560 		if (vsock_stream_has_data(vsk) <= 0)
1561 			sk->sk_state = SS_DISCONNECTING;
1562 
1563 		sk->sk_state_change(sk);
1564 		break;
1565 
1566 	default:
1567 		vsk = vsock_sk(sk);
1568 		vmci_trans(vsk)->notify_ops->handle_notify_pkt(
1569 				sk, pkt, false, NULL, NULL,
1570 				&pkt_processed);
1571 		if (!pkt_processed)
1572 			return -EINVAL;
1573 
1574 		break;
1575 	}
1576 
1577 	return 0;
1578 }
1579 
1580 static int vmci_transport_socket_init(struct vsock_sock *vsk,
1581 				      struct vsock_sock *psk)
1582 {
1583 	vsk->trans = kmalloc(sizeof(struct vmci_transport), GFP_KERNEL);
1584 	if (!vsk->trans)
1585 		return -ENOMEM;
1586 
1587 	vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
1588 	vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
1589 	vmci_trans(vsk)->qpair = NULL;
1590 	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size = 0;
1591 	vmci_trans(vsk)->attach_sub_id = vmci_trans(vsk)->detach_sub_id =
1592 		VMCI_INVALID_ID;
1593 	vmci_trans(vsk)->notify_ops = NULL;
1594 	if (psk) {
1595 		vmci_trans(vsk)->queue_pair_size =
1596 			vmci_trans(psk)->queue_pair_size;
1597 		vmci_trans(vsk)->queue_pair_min_size =
1598 			vmci_trans(psk)->queue_pair_min_size;
1599 		vmci_trans(vsk)->queue_pair_max_size =
1600 			vmci_trans(psk)->queue_pair_max_size;
1601 	} else {
1602 		vmci_trans(vsk)->queue_pair_size =
1603 			VMCI_TRANSPORT_DEFAULT_QP_SIZE;
1604 		vmci_trans(vsk)->queue_pair_min_size =
1605 			 VMCI_TRANSPORT_DEFAULT_QP_SIZE_MIN;
1606 		vmci_trans(vsk)->queue_pair_max_size =
1607 			VMCI_TRANSPORT_DEFAULT_QP_SIZE_MAX;
1608 	}
1609 
1610 	return 0;
1611 }
1612 
1613 static void vmci_transport_destruct(struct vsock_sock *vsk)
1614 {
1615 	if (vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID) {
1616 		vmci_event_unsubscribe(vmci_trans(vsk)->attach_sub_id);
1617 		vmci_trans(vsk)->attach_sub_id = VMCI_INVALID_ID;
1618 	}
1619 
1620 	if (vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
1621 		vmci_event_unsubscribe(vmci_trans(vsk)->detach_sub_id);
1622 		vmci_trans(vsk)->detach_sub_id = VMCI_INVALID_ID;
1623 	}
1624 
1625 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
1626 		vmci_qpair_detach(&vmci_trans(vsk)->qpair);
1627 		vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
1628 		vmci_trans(vsk)->produce_size = 0;
1629 		vmci_trans(vsk)->consume_size = 0;
1630 	}
1631 
1632 	if (vmci_trans(vsk)->notify_ops)
1633 		vmci_trans(vsk)->notify_ops->socket_destruct(vsk);
1634 
1635 	kfree(vsk->trans);
1636 	vsk->trans = NULL;
1637 }
1638 
1639 static void vmci_transport_release(struct vsock_sock *vsk)
1640 {
1641 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->dg_handle)) {
1642 		vmci_datagram_destroy_handle(vmci_trans(vsk)->dg_handle);
1643 		vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
1644 	}
1645 }
1646 
1647 static int vmci_transport_dgram_bind(struct vsock_sock *vsk,
1648 				     struct sockaddr_vm *addr)
1649 {
1650 	u32 port;
1651 	u32 flags;
1652 	int err;
1653 
1654 	/* VMCI will select a resource ID for us if we provide
1655 	 * VMCI_INVALID_ID.
1656 	 */
1657 	port = addr->svm_port == VMADDR_PORT_ANY ?
1658 			VMCI_INVALID_ID : addr->svm_port;
1659 
1660 	if (port <= LAST_RESERVED_PORT && !capable(CAP_NET_BIND_SERVICE))
1661 		return -EACCES;
1662 
1663 	flags = addr->svm_cid == VMADDR_CID_ANY ?
1664 				VMCI_FLAG_ANYCID_DG_HND : 0;
1665 
1666 	err = vmci_transport_datagram_create_hnd(port, flags,
1667 						 vmci_transport_recv_dgram_cb,
1668 						 &vsk->sk,
1669 						 &vmci_trans(vsk)->dg_handle);
1670 	if (err < VMCI_SUCCESS)
1671 		return vmci_transport_error_to_vsock_error(err);
1672 	vsock_addr_init(&vsk->local_addr, addr->svm_cid,
1673 			vmci_trans(vsk)->dg_handle.resource);
1674 
1675 	return 0;
1676 }
1677 
1678 static int vmci_transport_dgram_enqueue(
1679 	struct vsock_sock *vsk,
1680 	struct sockaddr_vm *remote_addr,
1681 	struct iovec *iov,
1682 	size_t len)
1683 {
1684 	int err;
1685 	struct vmci_datagram *dg;
1686 
1687 	if (len > VMCI_MAX_DG_PAYLOAD_SIZE)
1688 		return -EMSGSIZE;
1689 
1690 	if (!vmci_transport_allow_dgram(vsk, remote_addr->svm_cid))
1691 		return -EPERM;
1692 
1693 	/* Allocate a buffer for the user's message and our packet header. */
1694 	dg = kmalloc(len + sizeof(*dg), GFP_KERNEL);
1695 	if (!dg)
1696 		return -ENOMEM;
1697 
1698 	memcpy_fromiovec(VMCI_DG_PAYLOAD(dg), iov, len);
1699 
1700 	dg->dst = vmci_make_handle(remote_addr->svm_cid,
1701 				   remote_addr->svm_port);
1702 	dg->src = vmci_make_handle(vsk->local_addr.svm_cid,
1703 				   vsk->local_addr.svm_port);
1704 	dg->payload_size = len;
1705 
1706 	err = vmci_datagram_send(dg);
1707 	kfree(dg);
1708 	if (err < 0)
1709 		return vmci_transport_error_to_vsock_error(err);
1710 
1711 	return err - sizeof(*dg);
1712 }
1713 
1714 static int vmci_transport_dgram_dequeue(struct kiocb *kiocb,
1715 					struct vsock_sock *vsk,
1716 					struct msghdr *msg, size_t len,
1717 					int flags)
1718 {
1719 	int err;
1720 	int noblock;
1721 	struct vmci_datagram *dg;
1722 	size_t payload_len;
1723 	struct sk_buff *skb;
1724 
1725 	noblock = flags & MSG_DONTWAIT;
1726 
1727 	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
1728 		return -EOPNOTSUPP;
1729 
1730 	/* Retrieve the head sk_buff from the socket's receive queue. */
1731 	err = 0;
1732 	skb = skb_recv_datagram(&vsk->sk, flags, noblock, &err);
1733 	if (err)
1734 		return err;
1735 
1736 	if (!skb)
1737 		return -EAGAIN;
1738 
1739 	dg = (struct vmci_datagram *)skb->data;
1740 	if (!dg)
1741 		/* err is 0, meaning we read zero bytes. */
1742 		goto out;
1743 
1744 	payload_len = dg->payload_size;
1745 	/* Ensure the sk_buff matches the payload size claimed in the packet. */
1746 	if (payload_len != skb->len - sizeof(*dg)) {
1747 		err = -EINVAL;
1748 		goto out;
1749 	}
1750 
1751 	if (payload_len > len) {
1752 		payload_len = len;
1753 		msg->msg_flags |= MSG_TRUNC;
1754 	}
1755 
1756 	/* Place the datagram payload in the user's iovec. */
1757 	err = skb_copy_datagram_iovec(skb, sizeof(*dg), msg->msg_iov,
1758 		payload_len);
1759 	if (err)
1760 		goto out;
1761 
1762 	msg->msg_namelen = 0;
1763 	if (msg->msg_name) {
1764 		struct sockaddr_vm *vm_addr;
1765 
1766 		/* Provide the address of the sender. */
1767 		vm_addr = (struct sockaddr_vm *)msg->msg_name;
1768 		vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
1769 		msg->msg_namelen = sizeof(*vm_addr);
1770 	}
1771 	err = payload_len;
1772 
1773 out:
1774 	skb_free_datagram(&vsk->sk, skb);
1775 	return err;
1776 }
1777 
1778 static bool vmci_transport_dgram_allow(u32 cid, u32 port)
1779 {
1780 	if (cid == VMADDR_CID_HYPERVISOR) {
1781 		/* Registrations of PBRPC Servers do not modify VMX/Hypervisor
1782 		 * state and are allowed.
1783 		 */
1784 		return port == VMCI_UNITY_PBRPC_REGISTER;
1785 	}
1786 
1787 	return true;
1788 }
1789 
1790 static int vmci_transport_connect(struct vsock_sock *vsk)
1791 {
1792 	int err;
1793 	bool old_pkt_proto = false;
1794 	struct sock *sk = &vsk->sk;
1795 
1796 	if (vmci_transport_old_proto_override(&old_pkt_proto) &&
1797 		old_pkt_proto) {
1798 		err = vmci_transport_send_conn_request(
1799 			sk, vmci_trans(vsk)->queue_pair_size);
1800 		if (err < 0) {
1801 			sk->sk_state = SS_UNCONNECTED;
1802 			return err;
1803 		}
1804 	} else {
1805 		int supported_proto_versions =
1806 			vmci_transport_new_proto_supported_versions();
1807 		err = vmci_transport_send_conn_request2(
1808 				sk, vmci_trans(vsk)->queue_pair_size,
1809 				supported_proto_versions);
1810 		if (err < 0) {
1811 			sk->sk_state = SS_UNCONNECTED;
1812 			return err;
1813 		}
1814 
1815 		vsk->sent_request = true;
1816 	}
1817 
1818 	return err;
1819 }
1820 
1821 static ssize_t vmci_transport_stream_dequeue(
1822 	struct vsock_sock *vsk,
1823 	struct iovec *iov,
1824 	size_t len,
1825 	int flags)
1826 {
1827 	if (flags & MSG_PEEK)
1828 		return vmci_qpair_peekv(vmci_trans(vsk)->qpair, iov, len, 0);
1829 	else
1830 		return vmci_qpair_dequev(vmci_trans(vsk)->qpair, iov, len, 0);
1831 }
1832 
1833 static ssize_t vmci_transport_stream_enqueue(
1834 	struct vsock_sock *vsk,
1835 	struct iovec *iov,
1836 	size_t len)
1837 {
1838 	return vmci_qpair_enquev(vmci_trans(vsk)->qpair, iov, len, 0);
1839 }
1840 
1841 static s64 vmci_transport_stream_has_data(struct vsock_sock *vsk)
1842 {
1843 	return vmci_qpair_consume_buf_ready(vmci_trans(vsk)->qpair);
1844 }
1845 
1846 static s64 vmci_transport_stream_has_space(struct vsock_sock *vsk)
1847 {
1848 	return vmci_qpair_produce_free_space(vmci_trans(vsk)->qpair);
1849 }
1850 
1851 static u64 vmci_transport_stream_rcvhiwat(struct vsock_sock *vsk)
1852 {
1853 	return vmci_trans(vsk)->consume_size;
1854 }
1855 
1856 static bool vmci_transport_stream_is_active(struct vsock_sock *vsk)
1857 {
1858 	return !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle);
1859 }
1860 
1861 static u64 vmci_transport_get_buffer_size(struct vsock_sock *vsk)
1862 {
1863 	return vmci_trans(vsk)->queue_pair_size;
1864 }
1865 
1866 static u64 vmci_transport_get_min_buffer_size(struct vsock_sock *vsk)
1867 {
1868 	return vmci_trans(vsk)->queue_pair_min_size;
1869 }
1870 
1871 static u64 vmci_transport_get_max_buffer_size(struct vsock_sock *vsk)
1872 {
1873 	return vmci_trans(vsk)->queue_pair_max_size;
1874 }
1875 
1876 static void vmci_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
1877 {
1878 	if (val < vmci_trans(vsk)->queue_pair_min_size)
1879 		vmci_trans(vsk)->queue_pair_min_size = val;
1880 	if (val > vmci_trans(vsk)->queue_pair_max_size)
1881 		vmci_trans(vsk)->queue_pair_max_size = val;
1882 	vmci_trans(vsk)->queue_pair_size = val;
1883 }
1884 
1885 static void vmci_transport_set_min_buffer_size(struct vsock_sock *vsk,
1886 					       u64 val)
1887 {
1888 	if (val > vmci_trans(vsk)->queue_pair_size)
1889 		vmci_trans(vsk)->queue_pair_size = val;
1890 	vmci_trans(vsk)->queue_pair_min_size = val;
1891 }
1892 
1893 static void vmci_transport_set_max_buffer_size(struct vsock_sock *vsk,
1894 					       u64 val)
1895 {
1896 	if (val < vmci_trans(vsk)->queue_pair_size)
1897 		vmci_trans(vsk)->queue_pair_size = val;
1898 	vmci_trans(vsk)->queue_pair_max_size = val;
1899 }
1900 
1901 static int vmci_transport_notify_poll_in(
1902 	struct vsock_sock *vsk,
1903 	size_t target,
1904 	bool *data_ready_now)
1905 {
1906 	return vmci_trans(vsk)->notify_ops->poll_in(
1907 			&vsk->sk, target, data_ready_now);
1908 }
1909 
1910 static int vmci_transport_notify_poll_out(
1911 	struct vsock_sock *vsk,
1912 	size_t target,
1913 	bool *space_available_now)
1914 {
1915 	return vmci_trans(vsk)->notify_ops->poll_out(
1916 			&vsk->sk, target, space_available_now);
1917 }
1918 
1919 static int vmci_transport_notify_recv_init(
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_init(
1925 			&vsk->sk, target,
1926 			(struct vmci_transport_recv_notify_data *)data);
1927 }
1928 
1929 static int vmci_transport_notify_recv_pre_block(
1930 	struct vsock_sock *vsk,
1931 	size_t target,
1932 	struct vsock_transport_recv_notify_data *data)
1933 {
1934 	return vmci_trans(vsk)->notify_ops->recv_pre_block(
1935 			&vsk->sk, target,
1936 			(struct vmci_transport_recv_notify_data *)data);
1937 }
1938 
1939 static int vmci_transport_notify_recv_pre_dequeue(
1940 	struct vsock_sock *vsk,
1941 	size_t target,
1942 	struct vsock_transport_recv_notify_data *data)
1943 {
1944 	return vmci_trans(vsk)->notify_ops->recv_pre_dequeue(
1945 			&vsk->sk, target,
1946 			(struct vmci_transport_recv_notify_data *)data);
1947 }
1948 
1949 static int vmci_transport_notify_recv_post_dequeue(
1950 	struct vsock_sock *vsk,
1951 	size_t target,
1952 	ssize_t copied,
1953 	bool data_read,
1954 	struct vsock_transport_recv_notify_data *data)
1955 {
1956 	return vmci_trans(vsk)->notify_ops->recv_post_dequeue(
1957 			&vsk->sk, target, copied, data_read,
1958 			(struct vmci_transport_recv_notify_data *)data);
1959 }
1960 
1961 static int vmci_transport_notify_send_init(
1962 	struct vsock_sock *vsk,
1963 	struct vsock_transport_send_notify_data *data)
1964 {
1965 	return vmci_trans(vsk)->notify_ops->send_init(
1966 			&vsk->sk,
1967 			(struct vmci_transport_send_notify_data *)data);
1968 }
1969 
1970 static int vmci_transport_notify_send_pre_block(
1971 	struct vsock_sock *vsk,
1972 	struct vsock_transport_send_notify_data *data)
1973 {
1974 	return vmci_trans(vsk)->notify_ops->send_pre_block(
1975 			&vsk->sk,
1976 			(struct vmci_transport_send_notify_data *)data);
1977 }
1978 
1979 static int vmci_transport_notify_send_pre_enqueue(
1980 	struct vsock_sock *vsk,
1981 	struct vsock_transport_send_notify_data *data)
1982 {
1983 	return vmci_trans(vsk)->notify_ops->send_pre_enqueue(
1984 			&vsk->sk,
1985 			(struct vmci_transport_send_notify_data *)data);
1986 }
1987 
1988 static int vmci_transport_notify_send_post_enqueue(
1989 	struct vsock_sock *vsk,
1990 	ssize_t written,
1991 	struct vsock_transport_send_notify_data *data)
1992 {
1993 	return vmci_trans(vsk)->notify_ops->send_post_enqueue(
1994 			&vsk->sk, written,
1995 			(struct vmci_transport_send_notify_data *)data);
1996 }
1997 
1998 static bool vmci_transport_old_proto_override(bool *old_pkt_proto)
1999 {
2000 	if (PROTOCOL_OVERRIDE != -1) {
2001 		if (PROTOCOL_OVERRIDE == 0)
2002 			*old_pkt_proto = true;
2003 		else
2004 			*old_pkt_proto = false;
2005 
2006 		pr_info("Proto override in use\n");
2007 		return true;
2008 	}
2009 
2010 	return false;
2011 }
2012 
2013 static bool vmci_transport_proto_to_notify_struct(struct sock *sk,
2014 						  u16 *proto,
2015 						  bool old_pkt_proto)
2016 {
2017 	struct vsock_sock *vsk = vsock_sk(sk);
2018 
2019 	if (old_pkt_proto) {
2020 		if (*proto != VSOCK_PROTO_INVALID) {
2021 			pr_err("Can't set both an old and new protocol\n");
2022 			return false;
2023 		}
2024 		vmci_trans(vsk)->notify_ops = &vmci_transport_notify_pkt_ops;
2025 		goto exit;
2026 	}
2027 
2028 	switch (*proto) {
2029 	case VSOCK_PROTO_PKT_ON_NOTIFY:
2030 		vmci_trans(vsk)->notify_ops =
2031 			&vmci_transport_notify_pkt_q_state_ops;
2032 		break;
2033 	default:
2034 		pr_err("Unknown notify protocol version\n");
2035 		return false;
2036 	}
2037 
2038 exit:
2039 	vmci_trans(vsk)->notify_ops->socket_init(sk);
2040 	return true;
2041 }
2042 
2043 static u16 vmci_transport_new_proto_supported_versions(void)
2044 {
2045 	if (PROTOCOL_OVERRIDE != -1)
2046 		return PROTOCOL_OVERRIDE;
2047 
2048 	return VSOCK_PROTO_ALL_SUPPORTED;
2049 }
2050 
2051 static u32 vmci_transport_get_local_cid(void)
2052 {
2053 	return vmci_get_context_id();
2054 }
2055 
2056 static struct vsock_transport vmci_transport = {
2057 	.init = vmci_transport_socket_init,
2058 	.destruct = vmci_transport_destruct,
2059 	.release = vmci_transport_release,
2060 	.connect = vmci_transport_connect,
2061 	.dgram_bind = vmci_transport_dgram_bind,
2062 	.dgram_dequeue = vmci_transport_dgram_dequeue,
2063 	.dgram_enqueue = vmci_transport_dgram_enqueue,
2064 	.dgram_allow = vmci_transport_dgram_allow,
2065 	.stream_dequeue = vmci_transport_stream_dequeue,
2066 	.stream_enqueue = vmci_transport_stream_enqueue,
2067 	.stream_has_data = vmci_transport_stream_has_data,
2068 	.stream_has_space = vmci_transport_stream_has_space,
2069 	.stream_rcvhiwat = vmci_transport_stream_rcvhiwat,
2070 	.stream_is_active = vmci_transport_stream_is_active,
2071 	.stream_allow = vmci_transport_stream_allow,
2072 	.notify_poll_in = vmci_transport_notify_poll_in,
2073 	.notify_poll_out = vmci_transport_notify_poll_out,
2074 	.notify_recv_init = vmci_transport_notify_recv_init,
2075 	.notify_recv_pre_block = vmci_transport_notify_recv_pre_block,
2076 	.notify_recv_pre_dequeue = vmci_transport_notify_recv_pre_dequeue,
2077 	.notify_recv_post_dequeue = vmci_transport_notify_recv_post_dequeue,
2078 	.notify_send_init = vmci_transport_notify_send_init,
2079 	.notify_send_pre_block = vmci_transport_notify_send_pre_block,
2080 	.notify_send_pre_enqueue = vmci_transport_notify_send_pre_enqueue,
2081 	.notify_send_post_enqueue = vmci_transport_notify_send_post_enqueue,
2082 	.shutdown = vmci_transport_shutdown,
2083 	.set_buffer_size = vmci_transport_set_buffer_size,
2084 	.set_min_buffer_size = vmci_transport_set_min_buffer_size,
2085 	.set_max_buffer_size = vmci_transport_set_max_buffer_size,
2086 	.get_buffer_size = vmci_transport_get_buffer_size,
2087 	.get_min_buffer_size = vmci_transport_get_min_buffer_size,
2088 	.get_max_buffer_size = vmci_transport_get_max_buffer_size,
2089 	.get_local_cid = vmci_transport_get_local_cid,
2090 };
2091 
2092 static int __init vmci_transport_init(void)
2093 {
2094 	int err;
2095 
2096 	/* Create the datagram handle that we will use to send and receive all
2097 	 * VSocket control messages for this context.
2098 	 */
2099 	err = vmci_transport_datagram_create_hnd(VMCI_TRANSPORT_PACKET_RID,
2100 						 VMCI_FLAG_ANYCID_DG_HND,
2101 						 vmci_transport_recv_stream_cb,
2102 						 NULL,
2103 						 &vmci_transport_stream_handle);
2104 	if (err < VMCI_SUCCESS) {
2105 		pr_err("Unable to create datagram handle. (%d)\n", err);
2106 		return vmci_transport_error_to_vsock_error(err);
2107 	}
2108 
2109 	err = vmci_event_subscribe(VMCI_EVENT_QP_RESUMED,
2110 				   vmci_transport_qp_resumed_cb,
2111 				   NULL, &vmci_transport_qp_resumed_sub_id);
2112 	if (err < VMCI_SUCCESS) {
2113 		pr_err("Unable to subscribe to resumed event. (%d)\n", err);
2114 		err = vmci_transport_error_to_vsock_error(err);
2115 		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
2116 		goto err_destroy_stream_handle;
2117 	}
2118 
2119 	err = vsock_core_init(&vmci_transport);
2120 	if (err < 0)
2121 		goto err_unsubscribe;
2122 
2123 	return 0;
2124 
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 	if (!vmci_handle_is_invalid(vmci_transport_stream_handle)) {
2136 		if (vmci_datagram_destroy_handle(
2137 			vmci_transport_stream_handle) != VMCI_SUCCESS)
2138 			pr_err("Couldn't destroy datagram handle\n");
2139 		vmci_transport_stream_handle = VMCI_INVALID_HANDLE;
2140 	}
2141 
2142 	if (vmci_transport_qp_resumed_sub_id != VMCI_INVALID_ID) {
2143 		vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
2144 		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
2145 	}
2146 
2147 	vsock_core_exit();
2148 }
2149 module_exit(vmci_transport_exit);
2150 
2151 MODULE_AUTHOR("VMware, Inc.");
2152 MODULE_DESCRIPTION("VMCI transport for Virtual Sockets");
2153 MODULE_LICENSE("GPL v2");
2154 MODULE_ALIAS("vmware_vsock");
2155 MODULE_ALIAS_NETPROTO(PF_VSOCK);
2156