Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * common code for virtio vsock
4 *
5 * Copyright (C) 2013-2015 Red Hat, Inc.
6 * Author: Asias He <asias@redhat.com>
7 * Stefan Hajnoczi <stefanha@redhat.com>
8 */
9#include <linux/spinlock.h>
10#include <linux/module.h>
11#include <linux/sched/signal.h>
12#include <linux/ctype.h>
13#include <linux/list.h>
14#include <linux/virtio_vsock.h>
15#include <uapi/linux/vsockmon.h>
16
17#include <net/sock.h>
18#include <net/af_vsock.h>
19
20#define CREATE_TRACE_POINTS
21#include <trace/events/vsock_virtio_transport_common.h>
22
23/* How long to wait for graceful shutdown of a connection */
24#define VSOCK_CLOSE_TIMEOUT (8 * HZ)
25
26/* Threshold for detecting small packets to copy */
27#define GOOD_COPY_LEN 128
28
29static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,
30 bool cancel_timeout);
31static s64 virtio_transport_has_space(struct virtio_vsock_sock *vvs);
32
33static const struct virtio_transport *
34virtio_transport_get_ops(struct vsock_sock *vsk)
35{
36 const struct vsock_transport *t = vsock_core_get_transport(vsk);
37
38 if (WARN_ON(!t))
39 return NULL;
40
41 return container_of(t, struct virtio_transport, transport);
42}
43
44static bool virtio_transport_can_zcopy(const struct virtio_transport *t_ops,
45 struct virtio_vsock_pkt_info *info,
46 size_t pkt_len)
47{
48 struct iov_iter *iov_iter;
49
50 if (!info->msg)
51 return false;
52
53 iov_iter = &info->msg->msg_iter;
54
55 if (iov_iter->iov_offset)
56 return false;
57
58 /* We can't send whole iov. */
59 if (iov_iter->count > pkt_len)
60 return false;
61
62 /* Check that transport can send data in zerocopy mode. */
63 if (t_ops->can_msgzerocopy) {
64 int pages_to_send = iov_iter_npages(iov_iter, MAX_SKB_FRAGS);
65
66 /* +1 is for packet header. */
67 return t_ops->can_msgzerocopy(pages_to_send + 1);
68 }
69
70 return true;
71}
72
73static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk,
74 struct sk_buff *skb,
75 struct msghdr *msg,
76 size_t pkt_len,
77 bool zerocopy)
78{
79 struct ubuf_info *uarg;
80
81 if (msg->msg_ubuf) {
82 uarg = msg->msg_ubuf;
83 net_zcopy_get(uarg);
84 } else {
85 struct ubuf_info_msgzc *uarg_zc;
86
87 uarg = msg_zerocopy_realloc(sk_vsock(vsk),
88 pkt_len, NULL, false);
89 if (!uarg)
90 return -1;
91
92 uarg_zc = uarg_to_msgzc(uarg);
93 uarg_zc->zerocopy = zerocopy ? 1 : 0;
94 }
95
96 skb_zcopy_init(skb, uarg);
97
98 return 0;
99}
100
101static int virtio_transport_fill_skb(struct sk_buff *skb,
102 struct virtio_vsock_pkt_info *info,
103 size_t len,
104 bool zcopy)
105{
106 struct msghdr *msg = info->msg;
107
108 if (zcopy)
109 return __zerocopy_sg_from_iter(msg, NULL, skb,
110 &msg->msg_iter, len, NULL);
111
112 virtio_vsock_skb_put(skb, len);
113 return skb_copy_datagram_from_iter_full(skb, 0, &msg->msg_iter, len);
114}
115
116static void virtio_transport_init_hdr(struct sk_buff *skb,
117 struct virtio_vsock_pkt_info *info,
118 size_t payload_len,
119 u32 src_cid,
120 u32 src_port,
121 u32 dst_cid,
122 u32 dst_port)
123{
124 struct virtio_vsock_hdr *hdr;
125
126 hdr = virtio_vsock_hdr(skb);
127 hdr->type = cpu_to_le16(info->type);
128 hdr->op = cpu_to_le16(info->op);
129 hdr->src_cid = cpu_to_le64(src_cid);
130 hdr->dst_cid = cpu_to_le64(dst_cid);
131 hdr->src_port = cpu_to_le32(src_port);
132 hdr->dst_port = cpu_to_le32(dst_port);
133 hdr->flags = cpu_to_le32(info->flags);
134 hdr->len = cpu_to_le32(payload_len);
135 hdr->buf_alloc = cpu_to_le32(0);
136 hdr->fwd_cnt = cpu_to_le32(0);
137}
138
139static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,
140 void *dst,
141 size_t len)
142{
143 struct iov_iter iov_iter = { 0 };
144 struct kvec kvec;
145 size_t to_copy;
146
147 kvec.iov_base = dst;
148 kvec.iov_len = len;
149
150 iov_iter.iter_type = ITER_KVEC;
151 iov_iter.kvec = &kvec;
152 iov_iter.nr_segs = 1;
153
154 to_copy = min_t(size_t, len, skb->len);
155
156 skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
157 &iov_iter, to_copy);
158}
159
160/* Packet capture */
161static struct sk_buff *virtio_transport_build_skb(void *opaque)
162{
163 struct virtio_vsock_hdr *pkt_hdr;
164 struct sk_buff *pkt = opaque;
165 struct af_vsockmon_hdr *hdr;
166 struct sk_buff *skb;
167 size_t payload_len;
168
169 /* A packet could be split to fit the RX buffer, so we can retrieve
170 * the payload length from the header and the buffer pointer taking
171 * care of the offset in the original packet.
172 */
173 pkt_hdr = virtio_vsock_hdr(pkt);
174 payload_len = pkt->len;
175
176 skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len,
177 GFP_ATOMIC);
178 if (!skb)
179 return NULL;
180
181 hdr = skb_put(skb, sizeof(*hdr));
182
183 /* pkt->hdr is little-endian so no need to byteswap here */
184 hdr->src_cid = pkt_hdr->src_cid;
185 hdr->src_port = pkt_hdr->src_port;
186 hdr->dst_cid = pkt_hdr->dst_cid;
187 hdr->dst_port = pkt_hdr->dst_port;
188
189 hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
190 hdr->len = cpu_to_le16(sizeof(*pkt_hdr));
191 memset(hdr->reserved, 0, sizeof(hdr->reserved));
192
193 switch (le16_to_cpu(pkt_hdr->op)) {
194 case VIRTIO_VSOCK_OP_REQUEST:
195 case VIRTIO_VSOCK_OP_RESPONSE:
196 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
197 break;
198 case VIRTIO_VSOCK_OP_RST:
199 case VIRTIO_VSOCK_OP_SHUTDOWN:
200 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
201 break;
202 case VIRTIO_VSOCK_OP_RW:
203 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
204 break;
205 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
206 case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
207 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
208 break;
209 default:
210 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
211 break;
212 }
213
214 skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr));
215
216 if (payload_len) {
217 if (skb_is_nonlinear(pkt)) {
218 void *data = skb_put(skb, payload_len);
219
220 virtio_transport_copy_nonlinear_skb(pkt, data, payload_len);
221 } else {
222 skb_put_data(skb, pkt->data, payload_len);
223 }
224 }
225
226 return skb;
227}
228
229void virtio_transport_deliver_tap_pkt(struct sk_buff *skb)
230{
231 if (virtio_vsock_skb_tap_delivered(skb))
232 return;
233
234 vsock_deliver_tap(virtio_transport_build_skb, skb);
235 virtio_vsock_skb_set_tap_delivered(skb);
236}
237EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
238
239static u16 virtio_transport_get_type(struct sock *sk)
240{
241 if (sk->sk_type == SOCK_STREAM)
242 return VIRTIO_VSOCK_TYPE_STREAM;
243 else
244 return VIRTIO_VSOCK_TYPE_SEQPACKET;
245}
246
247/* Returns new sk_buff on success, otherwise returns NULL. */
248static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info,
249 size_t payload_len,
250 bool zcopy,
251 u32 src_cid,
252 u32 src_port,
253 u32 dst_cid,
254 u32 dst_port)
255{
256 struct vsock_sock *vsk;
257 struct sk_buff *skb;
258 size_t skb_len;
259
260 skb_len = VIRTIO_VSOCK_SKB_HEADROOM;
261
262 if (!zcopy)
263 skb_len += payload_len;
264
265 skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
266 if (!skb)
267 return NULL;
268
269 virtio_transport_init_hdr(skb, info, payload_len, src_cid, src_port,
270 dst_cid, dst_port);
271
272 vsk = info->vsk;
273
274 /* If 'vsk' != NULL then payload is always present, so we
275 * will never call '__zerocopy_sg_from_iter()' below without
276 * setting skb owner in 'skb_set_owner_w()'. The only case
277 * when 'vsk' == NULL is VIRTIO_VSOCK_OP_RST control message
278 * without payload.
279 */
280 WARN_ON_ONCE(!(vsk && (info->msg && payload_len)) && zcopy);
281
282 /* Set owner here, because '__zerocopy_sg_from_iter()' uses
283 * owner of skb without check to update 'sk_wmem_alloc'.
284 */
285 if (vsk)
286 skb_set_owner_w(skb, sk_vsock(vsk));
287
288 if (info->msg && payload_len > 0) {
289 int err;
290
291 err = virtio_transport_fill_skb(skb, info, payload_len, zcopy);
292 if (err)
293 goto out;
294
295 if (msg_data_left(info->msg) == 0 &&
296 info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
297 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
298
299 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
300
301 if (info->msg->msg_flags & MSG_EOR)
302 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
303 }
304 }
305
306 if (info->reply)
307 virtio_vsock_skb_set_reply(skb);
308
309 trace_virtio_transport_alloc_pkt(src_cid, src_port,
310 dst_cid, dst_port,
311 payload_len,
312 info->type,
313 info->op,
314 info->flags,
315 zcopy);
316
317 return skb;
318out:
319 kfree_skb(skb);
320 return NULL;
321}
322
323/* This function can only be used on connecting/connected sockets,
324 * since a socket assigned to a transport is required.
325 *
326 * Do not use on listener sockets!
327 */
328static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
329 struct virtio_vsock_pkt_info *info)
330{
331 u32 max_skb_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
332 u32 src_cid, src_port, dst_cid, dst_port;
333 const struct virtio_transport *t_ops;
334 struct virtio_vsock_sock *vvs;
335 u32 pkt_len = info->pkt_len;
336 bool can_zcopy = false;
337 u32 rest_len;
338 int ret;
339
340 info->type = virtio_transport_get_type(sk_vsock(vsk));
341
342 t_ops = virtio_transport_get_ops(vsk);
343 if (unlikely(!t_ops))
344 return -EFAULT;
345
346 src_cid = t_ops->transport.get_local_cid();
347 src_port = vsk->local_addr.svm_port;
348 if (!info->remote_cid) {
349 dst_cid = vsk->remote_addr.svm_cid;
350 dst_port = vsk->remote_addr.svm_port;
351 } else {
352 dst_cid = info->remote_cid;
353 dst_port = info->remote_port;
354 }
355
356 vvs = vsk->trans;
357
358 /* virtio_transport_get_credit might return less than pkt_len credit */
359 pkt_len = virtio_transport_get_credit(vvs, pkt_len);
360
361 /* Do not send zero length OP_RW pkt */
362 if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
363 return pkt_len;
364
365 if (info->msg) {
366 /* If zerocopy is not enabled by 'setsockopt()', we behave as
367 * there is no MSG_ZEROCOPY flag set.
368 */
369 if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY))
370 info->msg->msg_flags &= ~MSG_ZEROCOPY;
371
372 if (info->msg->msg_flags & MSG_ZEROCOPY)
373 can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len);
374
375 if (can_zcopy)
376 max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE,
377 (MAX_SKB_FRAGS * PAGE_SIZE));
378 }
379
380 rest_len = pkt_len;
381
382 do {
383 struct sk_buff *skb;
384 size_t skb_len;
385
386 skb_len = min(max_skb_len, rest_len);
387
388 skb = virtio_transport_alloc_skb(info, skb_len, can_zcopy,
389 src_cid, src_port,
390 dst_cid, dst_port);
391 if (!skb) {
392 ret = -ENOMEM;
393 break;
394 }
395
396 /* We process buffer part by part, allocating skb on
397 * each iteration. If this is last skb for this buffer
398 * and MSG_ZEROCOPY mode is in use - we must allocate
399 * completion for the current syscall.
400 *
401 * Pass pkt_len because msg iter is already consumed
402 * by virtio_transport_fill_skb(), so iter->count
403 * can not be used for RLIMIT_MEMLOCK pinned-pages
404 * accounting done by msg_zerocopy_realloc().
405 */
406 if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY &&
407 skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) {
408 if (virtio_transport_init_zcopy_skb(vsk, skb,
409 info->msg,
410 pkt_len,
411 can_zcopy)) {
412 kfree_skb(skb);
413 ret = -ENOMEM;
414 break;
415 }
416 }
417
418 virtio_transport_inc_tx_pkt(vvs, skb);
419
420 ret = t_ops->send_pkt(skb, info->net);
421 if (ret < 0)
422 break;
423
424 /* Both virtio and vhost 'send_pkt()' returns 'skb_len',
425 * but for reliability use 'ret' instead of 'skb_len'.
426 * Also if partial send happens (e.g. 'ret' != 'skb_len')
427 * somehow, we break this loop, but account such returned
428 * value in 'virtio_transport_put_credit()'.
429 */
430 rest_len -= ret;
431
432 if (WARN_ONCE(ret != skb_len,
433 "'send_pkt()' returns %i, but %zu expected\n",
434 ret, skb_len))
435 break;
436 } while (rest_len);
437
438 virtio_transport_put_credit(vvs, rest_len);
439
440 /* Return number of bytes, if any data has been sent. */
441 if (rest_len != pkt_len)
442 ret = pkt_len - rest_len;
443
444 return ret;
445}
446
447static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
448 u32 len)
449{
450 if (vvs->buf_used + len > vvs->buf_alloc)
451 return false;
452
453 vvs->rx_bytes += len;
454 vvs->buf_used += len;
455 return true;
456}
457
458static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
459 u32 bytes_read, u32 bytes_dequeued)
460{
461 vvs->rx_bytes -= bytes_read;
462 vvs->buf_used -= bytes_dequeued;
463 vvs->fwd_cnt += bytes_dequeued;
464}
465
466void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb)
467{
468 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
469
470 spin_lock_bh(&vvs->rx_lock);
471 vvs->last_fwd_cnt = vvs->fwd_cnt;
472 hdr->fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
473 hdr->buf_alloc = cpu_to_le32(vvs->buf_alloc);
474 spin_unlock_bh(&vvs->rx_lock);
475}
476EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
477
478void virtio_transport_consume_skb_sent(struct sk_buff *skb, bool consume)
479{
480 struct sock *s = skb->sk;
481
482 if (s && skb->len) {
483 struct vsock_sock *vs = vsock_sk(s);
484 struct virtio_vsock_sock *vvs;
485
486 vvs = vs->trans;
487
488 spin_lock_bh(&vvs->tx_lock);
489 vvs->bytes_unsent -= skb->len;
490 spin_unlock_bh(&vvs->tx_lock);
491 }
492
493 if (consume)
494 consume_skb(skb);
495}
496EXPORT_SYMBOL_GPL(virtio_transport_consume_skb_sent);
497
498u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
499{
500 u32 ret;
501
502 if (!credit)
503 return 0;
504
505 spin_lock_bh(&vvs->tx_lock);
506 ret = min_t(u32, credit, virtio_transport_has_space(vvs));
507 vvs->tx_cnt += ret;
508 vvs->bytes_unsent += ret;
509 spin_unlock_bh(&vvs->tx_lock);
510
511 return ret;
512}
513EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
514
515void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
516{
517 if (!credit)
518 return;
519
520 spin_lock_bh(&vvs->tx_lock);
521 vvs->tx_cnt -= credit;
522 vvs->bytes_unsent -= credit;
523 spin_unlock_bh(&vvs->tx_lock);
524}
525EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
526
527static int virtio_transport_send_credit_update(struct vsock_sock *vsk)
528{
529 struct virtio_vsock_pkt_info info = {
530 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
531 .vsk = vsk,
532 .net = sock_net(sk_vsock(vsk)),
533 };
534
535 return virtio_transport_send_pkt_info(vsk, &info);
536}
537
538static ssize_t
539virtio_transport_stream_do_peek(struct vsock_sock *vsk,
540 struct msghdr *msg,
541 size_t len)
542{
543 struct virtio_vsock_sock *vvs = vsk->trans;
544 struct sk_buff *skb;
545 size_t total = 0;
546 int err;
547
548 spin_lock_bh(&vvs->rx_lock);
549
550 skb_queue_walk(&vvs->rx_queue, skb) {
551 size_t bytes;
552
553 bytes = min_t(size_t, len - total,
554 skb->len - VIRTIO_VSOCK_SKB_CB(skb)->offset);
555
556 spin_unlock_bh(&vvs->rx_lock);
557
558 /* sk_lock is held by caller so no one else can dequeue.
559 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
560 */
561 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
562 &msg->msg_iter, bytes);
563 if (err)
564 goto out;
565
566 total += bytes;
567
568 spin_lock_bh(&vvs->rx_lock);
569
570 if (total == len)
571 break;
572 }
573
574 spin_unlock_bh(&vvs->rx_lock);
575
576 return total;
577
578out:
579 if (total)
580 err = total;
581 return err;
582}
583
584static ssize_t
585virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
586 struct msghdr *msg,
587 size_t len)
588{
589 struct virtio_vsock_sock *vvs = vsk->trans;
590 struct sk_buff *skb;
591 u32 fwd_cnt_delta;
592 bool low_rx_bytes;
593 int err = -EFAULT;
594 size_t total = 0;
595 u32 free_space;
596
597 spin_lock_bh(&vvs->rx_lock);
598
599 if (WARN_ONCE(skb_queue_empty(&vvs->rx_queue) && vvs->rx_bytes,
600 "rx_queue is empty, but rx_bytes is non-zero\n")) {
601 spin_unlock_bh(&vvs->rx_lock);
602 return err;
603 }
604
605 while (total < len && !skb_queue_empty(&vvs->rx_queue)) {
606 size_t bytes, dequeued = 0;
607
608 skb = skb_peek(&vvs->rx_queue);
609
610 bytes = min_t(size_t, len - total,
611 skb->len - VIRTIO_VSOCK_SKB_CB(skb)->offset);
612
613 /* sk_lock is held by caller so no one else can dequeue.
614 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
615 */
616 spin_unlock_bh(&vvs->rx_lock);
617
618 err = skb_copy_datagram_iter(skb,
619 VIRTIO_VSOCK_SKB_CB(skb)->offset,
620 &msg->msg_iter, bytes);
621 if (err)
622 goto out;
623
624 spin_lock_bh(&vvs->rx_lock);
625
626 total += bytes;
627
628 VIRTIO_VSOCK_SKB_CB(skb)->offset += bytes;
629
630 if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->offset) {
631 dequeued = le32_to_cpu(virtio_vsock_hdr(skb)->len);
632 __skb_unlink(skb, &vvs->rx_queue);
633 consume_skb(skb);
634 }
635
636 virtio_transport_dec_rx_pkt(vvs, bytes, dequeued);
637 }
638
639 fwd_cnt_delta = vvs->fwd_cnt - vvs->last_fwd_cnt;
640 free_space = vvs->buf_alloc - fwd_cnt_delta;
641 low_rx_bytes = (vvs->rx_bytes <
642 sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX));
643
644 spin_unlock_bh(&vvs->rx_lock);
645
646 /* To reduce the number of credit update messages,
647 * don't update credits as long as lots of space is available.
648 * Note: the limit chosen here is arbitrary. Setting the limit
649 * too high causes extra messages. Too low causes transmitter
650 * stalls. As stalls are in theory more expensive than extra
651 * messages, we set the limit to a high value. TODO: experiment
652 * with different values. Also send credit update message when
653 * number of bytes in rx queue is not enough to wake up reader.
654 */
655 if (fwd_cnt_delta &&
656 (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || low_rx_bytes))
657 virtio_transport_send_credit_update(vsk);
658
659 return total;
660
661out:
662 if (total)
663 err = total;
664 return err;
665}
666
667static ssize_t
668virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
669 struct msghdr *msg)
670{
671 struct virtio_vsock_sock *vvs = vsk->trans;
672 struct sk_buff *skb;
673 size_t total, len;
674
675 spin_lock_bh(&vvs->rx_lock);
676
677 if (!vvs->msg_count) {
678 spin_unlock_bh(&vvs->rx_lock);
679 return 0;
680 }
681
682 total = 0;
683 len = msg_data_left(msg);
684
685 skb_queue_walk(&vvs->rx_queue, skb) {
686 struct virtio_vsock_hdr *hdr;
687
688 if (total < len) {
689 size_t bytes;
690 int err;
691
692 bytes = len - total;
693 if (bytes > skb->len)
694 bytes = skb->len;
695
696 spin_unlock_bh(&vvs->rx_lock);
697
698 /* sk_lock is held by caller so no one else can dequeue.
699 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
700 */
701 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
702 &msg->msg_iter, bytes);
703 if (err)
704 return err;
705
706 spin_lock_bh(&vvs->rx_lock);
707 }
708
709 total += skb->len;
710 hdr = virtio_vsock_hdr(skb);
711
712 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
713 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
714 msg->msg_flags |= MSG_EOR;
715
716 break;
717 }
718 }
719
720 spin_unlock_bh(&vvs->rx_lock);
721
722 return total;
723}
724
725static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
726 struct msghdr *msg,
727 int flags)
728{
729 struct virtio_vsock_sock *vvs = vsk->trans;
730 int dequeued_len = 0;
731 size_t user_buf_len = msg_data_left(msg);
732 bool msg_ready = false;
733 struct sk_buff *skb;
734
735 spin_lock_bh(&vvs->rx_lock);
736
737 if (vvs->msg_count == 0) {
738 spin_unlock_bh(&vvs->rx_lock);
739 return 0;
740 }
741
742 while (!msg_ready) {
743 struct virtio_vsock_hdr *hdr;
744 size_t pkt_len;
745
746 skb = __skb_dequeue(&vvs->rx_queue);
747 if (!skb)
748 break;
749 hdr = virtio_vsock_hdr(skb);
750 pkt_len = (size_t)le32_to_cpu(hdr->len);
751
752 if (dequeued_len >= 0) {
753 size_t bytes_to_copy;
754
755 bytes_to_copy = min(user_buf_len, pkt_len);
756
757 if (bytes_to_copy) {
758 int err;
759
760 /* sk_lock is held by caller so no one else can dequeue.
761 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
762 */
763 spin_unlock_bh(&vvs->rx_lock);
764
765 err = skb_copy_datagram_iter(skb, 0,
766 &msg->msg_iter,
767 bytes_to_copy);
768 if (err) {
769 /* Copy of message failed. Rest of
770 * fragments will be freed without copy.
771 */
772 dequeued_len = err;
773 } else {
774 user_buf_len -= bytes_to_copy;
775 }
776
777 spin_lock_bh(&vvs->rx_lock);
778 }
779
780 if (dequeued_len >= 0)
781 dequeued_len += pkt_len;
782 }
783
784 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
785 msg_ready = true;
786 vvs->msg_count--;
787
788 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
789 msg->msg_flags |= MSG_EOR;
790 }
791
792 virtio_transport_dec_rx_pkt(vvs, pkt_len, pkt_len);
793 kfree_skb(skb);
794 }
795
796 spin_unlock_bh(&vvs->rx_lock);
797
798 virtio_transport_send_credit_update(vsk);
799
800 return dequeued_len;
801}
802
803ssize_t
804virtio_transport_stream_dequeue(struct vsock_sock *vsk,
805 struct msghdr *msg,
806 size_t len, int flags)
807{
808 if (flags & MSG_PEEK)
809 return virtio_transport_stream_do_peek(vsk, msg, len);
810 else
811 return virtio_transport_stream_do_dequeue(vsk, msg, len);
812}
813EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
814
815ssize_t
816virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
817 struct msghdr *msg,
818 int flags)
819{
820 if (flags & MSG_PEEK)
821 return virtio_transport_seqpacket_do_peek(vsk, msg);
822 else
823 return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
824}
825EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
826
827static u32 virtio_transport_tx_buf_size(struct virtio_vsock_sock *vvs)
828{
829 /* The peer advertises its receive buffer via peer_buf_alloc, but we
830 * cap it to our local buf_alloc so a remote peer cannot force us to
831 * queue more data than our own buffer configuration allows.
832 */
833 return min(vvs->peer_buf_alloc, vvs->buf_alloc);
834}
835
836int
837virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
838 struct msghdr *msg,
839 size_t len)
840{
841 struct virtio_vsock_sock *vvs = vsk->trans;
842
843 spin_lock_bh(&vvs->tx_lock);
844
845 if (len > virtio_transport_tx_buf_size(vvs)) {
846 spin_unlock_bh(&vvs->tx_lock);
847 return -EMSGSIZE;
848 }
849
850 spin_unlock_bh(&vvs->tx_lock);
851
852 return virtio_transport_stream_enqueue(vsk, msg, len);
853}
854EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
855
856int
857virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
858 struct msghdr *msg,
859 size_t len, int flags)
860{
861 return -EOPNOTSUPP;
862}
863EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
864
865s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
866{
867 struct virtio_vsock_sock *vvs = vsk->trans;
868 s64 bytes;
869
870 spin_lock_bh(&vvs->rx_lock);
871 bytes = vvs->rx_bytes;
872 spin_unlock_bh(&vvs->rx_lock);
873
874 return bytes;
875}
876EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
877
878u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk)
879{
880 struct virtio_vsock_sock *vvs = vsk->trans;
881 u32 msg_count;
882
883 spin_lock_bh(&vvs->rx_lock);
884 msg_count = vvs->msg_count;
885 spin_unlock_bh(&vvs->rx_lock);
886
887 return msg_count;
888}
889EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data);
890
891static s64 virtio_transport_has_space(struct virtio_vsock_sock *vvs)
892{
893 s64 bytes;
894
895 /* Use s64 arithmetic so if the peer shrinks peer_buf_alloc while
896 * we have bytes in flight (tx_cnt - peer_fwd_cnt), the subtraction
897 * does not underflow.
898 */
899 bytes = (s64)virtio_transport_tx_buf_size(vvs) -
900 (vvs->tx_cnt - vvs->peer_fwd_cnt);
901 if (bytes < 0)
902 bytes = 0;
903
904 return bytes;
905}
906
907s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
908{
909 struct virtio_vsock_sock *vvs = vsk->trans;
910 s64 bytes;
911
912 spin_lock_bh(&vvs->tx_lock);
913 bytes = virtio_transport_has_space(vvs);
914 spin_unlock_bh(&vvs->tx_lock);
915
916 return bytes;
917}
918EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
919
920int virtio_transport_do_socket_init(struct vsock_sock *vsk,
921 struct vsock_sock *psk)
922{
923 struct virtio_vsock_sock *vvs;
924
925 vvs = kzalloc_obj(*vvs);
926 if (!vvs)
927 return -ENOMEM;
928
929 vsk->trans = vvs;
930 vvs->vsk = vsk;
931 if (psk && psk->trans) {
932 struct virtio_vsock_sock *ptrans = psk->trans;
933
934 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
935 }
936
937 if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
938 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
939
940 vvs->buf_alloc = vsk->buffer_size;
941
942 spin_lock_init(&vvs->rx_lock);
943 spin_lock_init(&vvs->tx_lock);
944 skb_queue_head_init(&vvs->rx_queue);
945
946 return 0;
947}
948EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
949
950/* sk_lock held by the caller */
951void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
952{
953 struct virtio_vsock_sock *vvs = vsk->trans;
954
955 if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
956 *val = VIRTIO_VSOCK_MAX_BUF_SIZE;
957
958 vvs->buf_alloc = *val;
959
960 virtio_transport_send_credit_update(vsk);
961}
962EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
963
964int
965virtio_transport_notify_poll_in(struct vsock_sock *vsk,
966 size_t target,
967 bool *data_ready_now)
968{
969 *data_ready_now = vsock_stream_has_data(vsk) >= target;
970
971 return 0;
972}
973EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
974
975int
976virtio_transport_notify_poll_out(struct vsock_sock *vsk,
977 size_t target,
978 bool *space_avail_now)
979{
980 s64 free_space;
981
982 free_space = vsock_stream_has_space(vsk);
983 if (free_space > 0)
984 *space_avail_now = true;
985 else if (free_space == 0)
986 *space_avail_now = false;
987
988 return 0;
989}
990EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
991
992int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
993 size_t target, struct vsock_transport_recv_notify_data *data)
994{
995 return 0;
996}
997EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
998
999int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
1000 size_t target, struct vsock_transport_recv_notify_data *data)
1001{
1002 return 0;
1003}
1004EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
1005
1006int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
1007 size_t target, struct vsock_transport_recv_notify_data *data)
1008{
1009 return 0;
1010}
1011EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
1012
1013int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
1014 size_t target, ssize_t copied, bool data_read,
1015 struct vsock_transport_recv_notify_data *data)
1016{
1017 return 0;
1018}
1019EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
1020
1021int virtio_transport_notify_send_init(struct vsock_sock *vsk,
1022 struct vsock_transport_send_notify_data *data)
1023{
1024 return 0;
1025}
1026EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
1027
1028int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
1029 struct vsock_transport_send_notify_data *data)
1030{
1031 return 0;
1032}
1033EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
1034
1035int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
1036 struct vsock_transport_send_notify_data *data)
1037{
1038 return 0;
1039}
1040EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
1041
1042int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
1043 ssize_t written, struct vsock_transport_send_notify_data *data)
1044{
1045 return 0;
1046}
1047EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
1048
1049u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
1050{
1051 return vsk->buffer_size;
1052}
1053EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
1054
1055bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
1056{
1057 return true;
1058}
1059EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
1060
1061int virtio_transport_dgram_bind(struct vsock_sock *vsk,
1062 struct sockaddr_vm *addr)
1063{
1064 return -EOPNOTSUPP;
1065}
1066EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
1067
1068bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port)
1069{
1070 return false;
1071}
1072EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
1073
1074int virtio_transport_connect(struct vsock_sock *vsk)
1075{
1076 struct virtio_vsock_pkt_info info = {
1077 .op = VIRTIO_VSOCK_OP_REQUEST,
1078 .vsk = vsk,
1079 .net = sock_net(sk_vsock(vsk)),
1080 };
1081
1082 return virtio_transport_send_pkt_info(vsk, &info);
1083}
1084EXPORT_SYMBOL_GPL(virtio_transport_connect);
1085
1086int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
1087{
1088 struct virtio_vsock_pkt_info info = {
1089 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
1090 .flags = (mode & RCV_SHUTDOWN ?
1091 VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
1092 (mode & SEND_SHUTDOWN ?
1093 VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
1094 .vsk = vsk,
1095 .net = sock_net(sk_vsock(vsk)),
1096 };
1097
1098 return virtio_transport_send_pkt_info(vsk, &info);
1099}
1100EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
1101
1102int
1103virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
1104 struct sockaddr_vm *remote_addr,
1105 struct msghdr *msg,
1106 size_t dgram_len)
1107{
1108 return -EOPNOTSUPP;
1109}
1110EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
1111
1112ssize_t
1113virtio_transport_stream_enqueue(struct vsock_sock *vsk,
1114 struct msghdr *msg,
1115 size_t len)
1116{
1117 struct virtio_vsock_pkt_info info = {
1118 .op = VIRTIO_VSOCK_OP_RW,
1119 .msg = msg,
1120 .pkt_len = len,
1121 .vsk = vsk,
1122 .net = sock_net(sk_vsock(vsk)),
1123 };
1124
1125 return virtio_transport_send_pkt_info(vsk, &info);
1126}
1127EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
1128
1129void virtio_transport_destruct(struct vsock_sock *vsk)
1130{
1131 struct virtio_vsock_sock *vvs = vsk->trans;
1132
1133 virtio_transport_cancel_close_work(vsk, true);
1134
1135 kfree(vvs);
1136 vsk->trans = NULL;
1137}
1138EXPORT_SYMBOL_GPL(virtio_transport_destruct);
1139
1140ssize_t virtio_transport_unsent_bytes(struct vsock_sock *vsk)
1141{
1142 struct virtio_vsock_sock *vvs = vsk->trans;
1143 size_t ret;
1144
1145 spin_lock_bh(&vvs->tx_lock);
1146 ret = vvs->bytes_unsent;
1147 spin_unlock_bh(&vvs->tx_lock);
1148
1149 return ret;
1150}
1151EXPORT_SYMBOL_GPL(virtio_transport_unsent_bytes);
1152
1153static int virtio_transport_reset(struct vsock_sock *vsk,
1154 struct sk_buff *skb)
1155{
1156 struct virtio_vsock_pkt_info info = {
1157 .op = VIRTIO_VSOCK_OP_RST,
1158 .reply = !!skb,
1159 .vsk = vsk,
1160 .net = sock_net(sk_vsock(vsk)),
1161 };
1162
1163 /* Send RST only if the original pkt is not a RST pkt */
1164 if (skb && le16_to_cpu(virtio_vsock_hdr(skb)->op) == VIRTIO_VSOCK_OP_RST)
1165 return 0;
1166
1167 return virtio_transport_send_pkt_info(vsk, &info);
1168}
1169
1170/* Normally packets are associated with a socket. There may be no socket if an
1171 * attempt was made to connect to a socket that does not exist.
1172 *
1173 * net refers to the namespace of whoever sent the invalid message. For
1174 * loopback, this is the namespace of the socket. For vhost, this is the
1175 * namespace of the VM (i.e., vhost_vsock).
1176 */
1177static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
1178 struct sk_buff *skb, struct net *net)
1179{
1180 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1181 struct virtio_vsock_pkt_info info = {
1182 .op = VIRTIO_VSOCK_OP_RST,
1183 .type = le16_to_cpu(hdr->type),
1184 .reply = true,
1185
1186 /* Set sk owner to socket we are replying to (may be NULL for
1187 * non-loopback). This keeps a reference to the sock and
1188 * sock_net(sk) until the reply skb is freed.
1189 */
1190 .vsk = vsock_sk(skb->sk),
1191
1192 /* net is not defined here because we pass it directly to
1193 * t->send_pkt(), instead of relying on
1194 * virtio_transport_send_pkt_info() to pass it. It is not needed
1195 * by virtio_transport_alloc_skb().
1196 */
1197 };
1198 struct sk_buff *reply;
1199
1200 /* Send RST only if the original pkt is not a RST pkt */
1201 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
1202 return 0;
1203
1204 if (!t)
1205 return -ENOTCONN;
1206
1207 reply = virtio_transport_alloc_skb(&info, 0, false,
1208 le64_to_cpu(hdr->dst_cid),
1209 le32_to_cpu(hdr->dst_port),
1210 le64_to_cpu(hdr->src_cid),
1211 le32_to_cpu(hdr->src_port));
1212 if (!reply)
1213 return -ENOMEM;
1214
1215 return t->send_pkt(reply, net);
1216}
1217
1218/* This function should be called with sk_lock held and SOCK_DONE set */
1219static void virtio_transport_remove_sock(struct vsock_sock *vsk)
1220{
1221 struct virtio_vsock_sock *vvs = vsk->trans;
1222
1223 /* We don't need to take rx_lock, as the socket is closing and we are
1224 * removing it.
1225 */
1226 __skb_queue_purge(&vvs->rx_queue);
1227 vsock_remove_sock(vsk);
1228}
1229
1230static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,
1231 bool cancel_timeout)
1232{
1233 struct sock *sk = sk_vsock(vsk);
1234
1235 if (vsk->close_work_scheduled &&
1236 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
1237 vsk->close_work_scheduled = false;
1238
1239 virtio_transport_remove_sock(vsk);
1240
1241 /* Release refcnt obtained when we scheduled the timeout */
1242 sock_put(sk);
1243 }
1244}
1245
1246static void virtio_transport_do_close(struct vsock_sock *vsk,
1247 bool cancel_timeout)
1248{
1249 struct sock *sk = sk_vsock(vsk);
1250
1251 sock_set_flag(sk, SOCK_DONE);
1252 vsk->peer_shutdown = SHUTDOWN_MASK;
1253 if (vsock_stream_has_data(vsk) <= 0)
1254 sk->sk_state = TCP_CLOSING;
1255 sk->sk_state_change(sk);
1256
1257 virtio_transport_cancel_close_work(vsk, cancel_timeout);
1258}
1259
1260static void virtio_transport_close_timeout(struct work_struct *work)
1261{
1262 struct vsock_sock *vsk =
1263 container_of(work, struct vsock_sock, close_work.work);
1264 struct sock *sk = sk_vsock(vsk);
1265
1266 sock_hold(sk);
1267 lock_sock(sk);
1268
1269 if (!sock_flag(sk, SOCK_DONE)) {
1270 (void)virtio_transport_reset(vsk, NULL);
1271
1272 virtio_transport_do_close(vsk, false);
1273 }
1274
1275 vsk->close_work_scheduled = false;
1276
1277 release_sock(sk);
1278 sock_put(sk);
1279}
1280
1281/* User context, vsk->sk is locked */
1282static bool virtio_transport_close(struct vsock_sock *vsk)
1283{
1284 struct sock *sk = &vsk->sk;
1285
1286 if (!(sk->sk_state == TCP_ESTABLISHED ||
1287 sk->sk_state == TCP_CLOSING))
1288 return true;
1289
1290 /* Already received SHUTDOWN from peer, reply with RST */
1291 if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
1292 (void)virtio_transport_reset(vsk, NULL);
1293 return true;
1294 }
1295
1296 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
1297 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
1298
1299 if (!(current->flags & PF_EXITING))
1300 vsock_linger(sk);
1301
1302 if (sock_flag(sk, SOCK_DONE)) {
1303 return true;
1304 }
1305
1306 sock_hold(sk);
1307 INIT_DELAYED_WORK(&vsk->close_work,
1308 virtio_transport_close_timeout);
1309 vsk->close_work_scheduled = true;
1310 schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
1311 return false;
1312}
1313
1314void virtio_transport_release(struct vsock_sock *vsk)
1315{
1316 struct sock *sk = &vsk->sk;
1317 bool remove_sock = true;
1318
1319 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
1320 remove_sock = virtio_transport_close(vsk);
1321
1322 if (remove_sock) {
1323 sock_set_flag(sk, SOCK_DONE);
1324 virtio_transport_remove_sock(vsk);
1325 }
1326}
1327EXPORT_SYMBOL_GPL(virtio_transport_release);
1328
1329static int
1330virtio_transport_recv_connecting(struct sock *sk,
1331 struct sk_buff *skb)
1332{
1333 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1334 struct vsock_sock *vsk = vsock_sk(sk);
1335 int skerr;
1336 int err;
1337
1338 switch (le16_to_cpu(hdr->op)) {
1339 case VIRTIO_VSOCK_OP_RESPONSE:
1340 sk->sk_state = TCP_ESTABLISHED;
1341 sk->sk_socket->state = SS_CONNECTED;
1342 vsock_insert_connected(vsk);
1343 sk->sk_state_change(sk);
1344 break;
1345 case VIRTIO_VSOCK_OP_INVALID:
1346 break;
1347 case VIRTIO_VSOCK_OP_RST:
1348 skerr = ECONNRESET;
1349 err = 0;
1350 goto destroy;
1351 default:
1352 skerr = EPROTO;
1353 err = -EINVAL;
1354 goto destroy;
1355 }
1356 return 0;
1357
1358destroy:
1359 virtio_transport_reset(vsk, skb);
1360 sk->sk_state = TCP_CLOSE;
1361 sk->sk_err = skerr;
1362 sk_error_report(sk);
1363 return err;
1364}
1365
1366static void
1367virtio_transport_recv_enqueue(struct vsock_sock *vsk,
1368 struct sk_buff *skb)
1369{
1370 struct virtio_vsock_sock *vvs = vsk->trans;
1371 bool can_enqueue, free_pkt = false;
1372 struct virtio_vsock_hdr *hdr;
1373 u32 len;
1374
1375 hdr = virtio_vsock_hdr(skb);
1376 len = le32_to_cpu(hdr->len);
1377
1378 spin_lock_bh(&vvs->rx_lock);
1379
1380 can_enqueue = virtio_transport_inc_rx_pkt(vvs, len);
1381 if (!can_enqueue) {
1382 free_pkt = true;
1383 goto out;
1384 }
1385
1386 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)
1387 vvs->msg_count++;
1388
1389 /* Try to copy small packets into the buffer of last packet queued,
1390 * to avoid wasting memory queueing the entire buffer with a small
1391 * payload. Skip non-linear (e.g. zerocopy) skbs; these carry payload
1392 * in skb_shinfo.
1393 */
1394 if (len <= GOOD_COPY_LEN && !skb_queue_empty(&vvs->rx_queue) &&
1395 !skb_is_nonlinear(skb)) {
1396 struct virtio_vsock_hdr *last_hdr;
1397 struct sk_buff *last_skb;
1398
1399 last_skb = skb_peek_tail(&vvs->rx_queue);
1400 last_hdr = virtio_vsock_hdr(last_skb);
1401
1402 /* If there is space in the last packet queued, we copy the
1403 * new packet in its buffer. We avoid this if the last packet
1404 * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is
1405 * delimiter of SEQPACKET message, so 'pkt' is the first packet
1406 * of a new message.
1407 */
1408 if (skb->len < skb_tailroom(last_skb) &&
1409 !(le32_to_cpu(last_hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)) {
1410 memcpy(skb_put(last_skb, skb->len), skb->data, skb->len);
1411 free_pkt = true;
1412 last_hdr->flags |= hdr->flags;
1413 le32_add_cpu(&last_hdr->len, len);
1414 goto out;
1415 }
1416 }
1417
1418 __skb_queue_tail(&vvs->rx_queue, skb);
1419
1420out:
1421 spin_unlock_bh(&vvs->rx_lock);
1422 if (free_pkt)
1423 kfree_skb(skb);
1424}
1425
1426static int
1427virtio_transport_recv_connected(struct sock *sk,
1428 struct sk_buff *skb)
1429{
1430 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1431 struct vsock_sock *vsk = vsock_sk(sk);
1432 int err = 0;
1433
1434 switch (le16_to_cpu(hdr->op)) {
1435 case VIRTIO_VSOCK_OP_RW:
1436 virtio_transport_recv_enqueue(vsk, skb);
1437 vsock_data_ready(sk);
1438 return err;
1439 case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
1440 virtio_transport_send_credit_update(vsk);
1441 break;
1442 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
1443 sk->sk_write_space(sk);
1444 break;
1445 case VIRTIO_VSOCK_OP_SHUTDOWN:
1446 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
1447 vsk->peer_shutdown |= RCV_SHUTDOWN;
1448 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
1449 vsk->peer_shutdown |= SEND_SHUTDOWN;
1450 if (vsk->peer_shutdown == SHUTDOWN_MASK) {
1451 if (vsock_stream_has_data(vsk) <= 0 && !sock_flag(sk, SOCK_DONE)) {
1452 (void)virtio_transport_reset(vsk, NULL);
1453 virtio_transport_do_close(vsk, true);
1454 }
1455 /* Remove this socket anyway because the remote peer sent
1456 * the shutdown. This way a new connection will succeed
1457 * if the remote peer uses the same source port,
1458 * even if the old socket is still unreleased, but now disconnected.
1459 */
1460 vsock_remove_sock(vsk);
1461 }
1462 if (le32_to_cpu(virtio_vsock_hdr(skb)->flags))
1463 sk->sk_state_change(sk);
1464 break;
1465 case VIRTIO_VSOCK_OP_RST:
1466 virtio_transport_do_close(vsk, true);
1467 break;
1468 default:
1469 err = -EINVAL;
1470 break;
1471 }
1472
1473 kfree_skb(skb);
1474 return err;
1475}
1476
1477static void
1478virtio_transport_recv_disconnecting(struct sock *sk,
1479 struct sk_buff *skb)
1480{
1481 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1482 struct vsock_sock *vsk = vsock_sk(sk);
1483
1484 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
1485 virtio_transport_do_close(vsk, true);
1486}
1487
1488static int
1489virtio_transport_send_response(struct vsock_sock *vsk,
1490 struct sk_buff *skb)
1491{
1492 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1493 struct virtio_vsock_pkt_info info = {
1494 .op = VIRTIO_VSOCK_OP_RESPONSE,
1495 .remote_cid = le64_to_cpu(hdr->src_cid),
1496 .remote_port = le32_to_cpu(hdr->src_port),
1497 .reply = true,
1498 .vsk = vsk,
1499 .net = sock_net(sk_vsock(vsk)),
1500 };
1501
1502 return virtio_transport_send_pkt_info(vsk, &info);
1503}
1504
1505static bool virtio_transport_space_update(struct sock *sk,
1506 struct sk_buff *skb)
1507{
1508 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1509 struct vsock_sock *vsk = vsock_sk(sk);
1510 struct virtio_vsock_sock *vvs = vsk->trans;
1511 bool space_available;
1512
1513 /* Listener sockets are not associated with any transport, so we are
1514 * not able to take the state to see if there is space available in the
1515 * remote peer, but since they are only used to receive requests, we
1516 * can assume that there is always space available in the other peer.
1517 */
1518 if (!vvs)
1519 return true;
1520
1521 /* buf_alloc and fwd_cnt is always included in the hdr */
1522 spin_lock_bh(&vvs->tx_lock);
1523 vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc);
1524 vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt);
1525 space_available = virtio_transport_has_space(vvs);
1526 spin_unlock_bh(&vvs->tx_lock);
1527 return space_available;
1528}
1529
1530/* Handle server socket */
1531static int
1532virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
1533 struct virtio_transport *t)
1534{
1535 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1536 struct vsock_sock *vsk = vsock_sk(sk);
1537 struct vsock_sock *vchild;
1538 struct sock *child;
1539 int ret;
1540
1541 if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
1542 virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1543 return -EINVAL;
1544 }
1545
1546 if (sk_acceptq_is_full(sk)) {
1547 virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1548 return -ENOMEM;
1549 }
1550
1551 /* __vsock_release() might have already flushed accept_queue.
1552 * Subsequent enqueues would lead to a memory leak.
1553 */
1554 if (sk->sk_shutdown == SHUTDOWN_MASK) {
1555 virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1556 return -ESHUTDOWN;
1557 }
1558
1559 child = vsock_create_connected(sk);
1560 if (!child) {
1561 virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1562 return -ENOMEM;
1563 }
1564
1565 lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1566
1567 child->sk_state = TCP_ESTABLISHED;
1568
1569 vchild = vsock_sk(child);
1570 vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid),
1571 le32_to_cpu(hdr->dst_port));
1572 vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid),
1573 le32_to_cpu(hdr->src_port));
1574
1575 ret = vsock_assign_transport(vchild, vsk);
1576 /* Transport assigned (looking at remote_addr) must be the same
1577 * where we received the request.
1578 */
1579 if (ret || vchild->transport != &t->transport) {
1580 release_sock(child);
1581 virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1582 sock_put(child);
1583 return ret;
1584 }
1585
1586 sk_acceptq_added(sk);
1587 if (virtio_transport_space_update(child, skb))
1588 child->sk_write_space(child);
1589
1590 vsock_insert_connected(vchild);
1591 vsock_enqueue_accept(sk, child);
1592 virtio_transport_send_response(vchild, skb);
1593
1594 release_sock(child);
1595
1596 sk->sk_data_ready(sk);
1597 return 0;
1598}
1599
1600static bool virtio_transport_valid_type(u16 type)
1601{
1602 return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
1603 (type == VIRTIO_VSOCK_TYPE_SEQPACKET);
1604}
1605
1606/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1607 * lock.
1608 */
1609void virtio_transport_recv_pkt(struct virtio_transport *t,
1610 struct sk_buff *skb, struct net *net)
1611{
1612 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1613 struct sockaddr_vm src, dst;
1614 struct vsock_sock *vsk;
1615 struct sock *sk;
1616 bool space_available;
1617
1618 vsock_addr_init(&src, le64_to_cpu(hdr->src_cid),
1619 le32_to_cpu(hdr->src_port));
1620 vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid),
1621 le32_to_cpu(hdr->dst_port));
1622
1623 trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1624 dst.svm_cid, dst.svm_port,
1625 le32_to_cpu(hdr->len),
1626 le16_to_cpu(hdr->type),
1627 le16_to_cpu(hdr->op),
1628 le32_to_cpu(hdr->flags),
1629 le32_to_cpu(hdr->buf_alloc),
1630 le32_to_cpu(hdr->fwd_cnt));
1631
1632 if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
1633 (void)virtio_transport_reset_no_sock(t, skb, net);
1634 goto free_pkt;
1635 }
1636
1637 /* The socket must be in connected or bound table
1638 * otherwise send reset back
1639 */
1640 sk = vsock_find_connected_socket_net(&src, &dst, net);
1641 if (!sk) {
1642 sk = vsock_find_bound_socket_net(&dst, net);
1643 if (!sk) {
1644 (void)virtio_transport_reset_no_sock(t, skb, net);
1645 goto free_pkt;
1646 }
1647 }
1648
1649 if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
1650 (void)virtio_transport_reset_no_sock(t, skb, net);
1651 sock_put(sk);
1652 goto free_pkt;
1653 }
1654
1655 if (!skb_set_owner_sk_safe(skb, sk)) {
1656 WARN_ONCE(1, "receiving vsock socket has sk_refcnt == 0\n");
1657 goto free_pkt;
1658 }
1659
1660 vsk = vsock_sk(sk);
1661
1662 lock_sock(sk);
1663
1664 /* Check if sk has been closed or assigned to another transport before
1665 * lock_sock (note: listener sockets are not assigned to any transport)
1666 */
1667 if (sock_flag(sk, SOCK_DONE) ||
1668 (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) {
1669 (void)virtio_transport_reset_no_sock(t, skb, net);
1670 release_sock(sk);
1671 sock_put(sk);
1672 goto free_pkt;
1673 }
1674
1675 space_available = virtio_transport_space_update(sk, skb);
1676
1677 /* Update CID in case it has changed after a transport reset event */
1678 if (vsk->local_addr.svm_cid != VMADDR_CID_ANY)
1679 vsk->local_addr.svm_cid = dst.svm_cid;
1680
1681 if (space_available)
1682 sk->sk_write_space(sk);
1683
1684 switch (sk->sk_state) {
1685 case TCP_LISTEN:
1686 virtio_transport_recv_listen(sk, skb, t);
1687 kfree_skb(skb);
1688 break;
1689 case TCP_SYN_SENT:
1690 virtio_transport_recv_connecting(sk, skb);
1691 kfree_skb(skb);
1692 break;
1693 case TCP_ESTABLISHED:
1694 virtio_transport_recv_connected(sk, skb);
1695 break;
1696 case TCP_CLOSING:
1697 virtio_transport_recv_disconnecting(sk, skb);
1698 kfree_skb(skb);
1699 break;
1700 default:
1701 (void)virtio_transport_reset_no_sock(t, skb, net);
1702 kfree_skb(skb);
1703 break;
1704 }
1705
1706 release_sock(sk);
1707
1708 /* Release refcnt obtained when we fetched this socket out of the
1709 * bound or connected list.
1710 */
1711 sock_put(sk);
1712 return;
1713
1714free_pkt:
1715 kfree_skb(skb);
1716}
1717EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1718
1719/* Remove skbs found in a queue that have a vsk that matches.
1720 *
1721 * Each skb is freed.
1722 *
1723 * Returns the count of skbs that were reply packets.
1724 */
1725int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue)
1726{
1727 struct sk_buff_head freeme;
1728 struct sk_buff *skb, *tmp;
1729 int cnt = 0;
1730
1731 skb_queue_head_init(&freeme);
1732
1733 spin_lock_bh(&queue->lock);
1734 skb_queue_walk_safe(queue, skb, tmp) {
1735 if (vsock_sk(skb->sk) != vsk)
1736 continue;
1737
1738 __skb_unlink(skb, queue);
1739 __skb_queue_tail(&freeme, skb);
1740
1741 if (virtio_vsock_skb_reply(skb))
1742 cnt++;
1743 }
1744 spin_unlock_bh(&queue->lock);
1745
1746 __skb_queue_purge(&freeme);
1747
1748 return cnt;
1749}
1750EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs);
1751
1752int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor)
1753{
1754 struct virtio_vsock_sock *vvs = vsk->trans;
1755 struct sock *sk = sk_vsock(vsk);
1756 struct virtio_vsock_hdr *hdr;
1757 struct sk_buff *skb;
1758 u32 pkt_len;
1759 int off = 0;
1760 int err;
1761
1762 spin_lock_bh(&vvs->rx_lock);
1763 /* Use __skb_recv_datagram() for race-free handling of the receive. It
1764 * works for types other than dgrams.
1765 */
1766 skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err);
1767 if (!skb) {
1768 spin_unlock_bh(&vvs->rx_lock);
1769 return err;
1770 }
1771
1772 hdr = virtio_vsock_hdr(skb);
1773 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)
1774 vvs->msg_count--;
1775
1776 pkt_len = le32_to_cpu(hdr->len);
1777 virtio_transport_dec_rx_pkt(vvs, pkt_len, pkt_len);
1778 spin_unlock_bh(&vvs->rx_lock);
1779
1780 virtio_transport_send_credit_update(vsk);
1781
1782 return recv_actor(sk, skb);
1783}
1784EXPORT_SYMBOL_GPL(virtio_transport_read_skb);
1785
1786int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val)
1787{
1788 struct virtio_vsock_sock *vvs = vsk->trans;
1789 bool send_update;
1790
1791 spin_lock_bh(&vvs->rx_lock);
1792
1793 /* If number of available bytes is less than new SO_RCVLOWAT value,
1794 * kick sender to send more data, because sender may sleep in its
1795 * 'send()' syscall waiting for enough space at our side. Also
1796 * don't send credit update when peer already knows actual value -
1797 * such transmission will be useless.
1798 */
1799 send_update = (vvs->rx_bytes < val) &&
1800 (vvs->fwd_cnt != vvs->last_fwd_cnt);
1801
1802 spin_unlock_bh(&vvs->rx_lock);
1803
1804 if (send_update) {
1805 int err;
1806
1807 err = virtio_transport_send_credit_update(vsk);
1808 if (err < 0)
1809 return err;
1810 }
1811
1812 return 0;
1813}
1814EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat);
1815
1816MODULE_LICENSE("GPL v2");
1817MODULE_AUTHOR("Asias He");
1818MODULE_DESCRIPTION("common code for virtio vsock");