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Merge tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block
[thirdparty/linux.git] / net / vmw_vsock / virtio_transport_common.c
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
29 static const struct virtio_transport *
30 virtio_transport_get_ops(struct vsock_sock *vsk)
31 {
32 const struct vsock_transport *t = vsock_core_get_transport(vsk);
33
34 if (WARN_ON(!t))
35 return NULL;
36
37 return container_of(t, struct virtio_transport, transport);
38 }
39
40 static struct virtio_vsock_pkt *
41 virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
42 size_t len,
43 u32 src_cid,
44 u32 src_port,
45 u32 dst_cid,
46 u32 dst_port)
47 {
48 struct virtio_vsock_pkt *pkt;
49 int err;
50
51 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
52 if (!pkt)
53 return NULL;
54
55 pkt->hdr.type = cpu_to_le16(info->type);
56 pkt->hdr.op = cpu_to_le16(info->op);
57 pkt->hdr.src_cid = cpu_to_le64(src_cid);
58 pkt->hdr.dst_cid = cpu_to_le64(dst_cid);
59 pkt->hdr.src_port = cpu_to_le32(src_port);
60 pkt->hdr.dst_port = cpu_to_le32(dst_port);
61 pkt->hdr.flags = cpu_to_le32(info->flags);
62 pkt->len = len;
63 pkt->hdr.len = cpu_to_le32(len);
64 pkt->reply = info->reply;
65 pkt->vsk = info->vsk;
66
67 if (info->msg && len > 0) {
68 pkt->buf = kmalloc(len, GFP_KERNEL);
69 if (!pkt->buf)
70 goto out_pkt;
71
72 pkt->buf_len = len;
73
74 err = memcpy_from_msg(pkt->buf, info->msg, len);
75 if (err)
76 goto out;
77 }
78
79 trace_virtio_transport_alloc_pkt(src_cid, src_port,
80 dst_cid, dst_port,
81 len,
82 info->type,
83 info->op,
84 info->flags);
85
86 return pkt;
87
88 out:
89 kfree(pkt->buf);
90 out_pkt:
91 kfree(pkt);
92 return NULL;
93 }
94
95 /* Packet capture */
96 static struct sk_buff *virtio_transport_build_skb(void *opaque)
97 {
98 struct virtio_vsock_pkt *pkt = opaque;
99 struct af_vsockmon_hdr *hdr;
100 struct sk_buff *skb;
101 size_t payload_len;
102 void *payload_buf;
103
104 /* A packet could be split to fit the RX buffer, so we can retrieve
105 * the payload length from the header and the buffer pointer taking
106 * care of the offset in the original packet.
107 */
108 payload_len = le32_to_cpu(pkt->hdr.len);
109 payload_buf = pkt->buf + pkt->off;
110
111 skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + payload_len,
112 GFP_ATOMIC);
113 if (!skb)
114 return NULL;
115
116 hdr = skb_put(skb, sizeof(*hdr));
117
118 /* pkt->hdr is little-endian so no need to byteswap here */
119 hdr->src_cid = pkt->hdr.src_cid;
120 hdr->src_port = pkt->hdr.src_port;
121 hdr->dst_cid = pkt->hdr.dst_cid;
122 hdr->dst_port = pkt->hdr.dst_port;
123
124 hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
125 hdr->len = cpu_to_le16(sizeof(pkt->hdr));
126 memset(hdr->reserved, 0, sizeof(hdr->reserved));
127
128 switch (le16_to_cpu(pkt->hdr.op)) {
129 case VIRTIO_VSOCK_OP_REQUEST:
130 case VIRTIO_VSOCK_OP_RESPONSE:
131 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
132 break;
133 case VIRTIO_VSOCK_OP_RST:
134 case VIRTIO_VSOCK_OP_SHUTDOWN:
135 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
136 break;
137 case VIRTIO_VSOCK_OP_RW:
138 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
139 break;
140 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
141 case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
142 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
143 break;
144 default:
145 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
146 break;
147 }
148
149 skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr));
150
151 if (payload_len) {
152 skb_put_data(skb, payload_buf, payload_len);
153 }
154
155 return skb;
156 }
157
158 void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
159 {
160 if (pkt->tap_delivered)
161 return;
162
163 vsock_deliver_tap(virtio_transport_build_skb, pkt);
164 pkt->tap_delivered = true;
165 }
166 EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
167
168 /* This function can only be used on connecting/connected sockets,
169 * since a socket assigned to a transport is required.
170 *
171 * Do not use on listener sockets!
172 */
173 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
174 struct virtio_vsock_pkt_info *info)
175 {
176 u32 src_cid, src_port, dst_cid, dst_port;
177 const struct virtio_transport *t_ops;
178 struct virtio_vsock_sock *vvs;
179 struct virtio_vsock_pkt *pkt;
180 u32 pkt_len = info->pkt_len;
181
182 t_ops = virtio_transport_get_ops(vsk);
183 if (unlikely(!t_ops))
184 return -EFAULT;
185
186 src_cid = t_ops->transport.get_local_cid();
187 src_port = vsk->local_addr.svm_port;
188 if (!info->remote_cid) {
189 dst_cid = vsk->remote_addr.svm_cid;
190 dst_port = vsk->remote_addr.svm_port;
191 } else {
192 dst_cid = info->remote_cid;
193 dst_port = info->remote_port;
194 }
195
196 vvs = vsk->trans;
197
198 /* we can send less than pkt_len bytes */
199 if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
200 pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
201
202 /* virtio_transport_get_credit might return less than pkt_len credit */
203 pkt_len = virtio_transport_get_credit(vvs, pkt_len);
204
205 /* Do not send zero length OP_RW pkt */
206 if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
207 return pkt_len;
208
209 pkt = virtio_transport_alloc_pkt(info, pkt_len,
210 src_cid, src_port,
211 dst_cid, dst_port);
212 if (!pkt) {
213 virtio_transport_put_credit(vvs, pkt_len);
214 return -ENOMEM;
215 }
216
217 virtio_transport_inc_tx_pkt(vvs, pkt);
218
219 return t_ops->send_pkt(pkt);
220 }
221
222 static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
223 struct virtio_vsock_pkt *pkt)
224 {
225 if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
226 return false;
227
228 vvs->rx_bytes += pkt->len;
229 return true;
230 }
231
232 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
233 struct virtio_vsock_pkt *pkt)
234 {
235 vvs->rx_bytes -= pkt->len;
236 vvs->fwd_cnt += pkt->len;
237 }
238
239 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
240 {
241 spin_lock_bh(&vvs->rx_lock);
242 vvs->last_fwd_cnt = vvs->fwd_cnt;
243 pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
244 pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
245 spin_unlock_bh(&vvs->rx_lock);
246 }
247 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
248
249 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
250 {
251 u32 ret;
252
253 spin_lock_bh(&vvs->tx_lock);
254 ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
255 if (ret > credit)
256 ret = credit;
257 vvs->tx_cnt += ret;
258 spin_unlock_bh(&vvs->tx_lock);
259
260 return ret;
261 }
262 EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
263
264 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
265 {
266 spin_lock_bh(&vvs->tx_lock);
267 vvs->tx_cnt -= credit;
268 spin_unlock_bh(&vvs->tx_lock);
269 }
270 EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
271
272 static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
273 int type,
274 struct virtio_vsock_hdr *hdr)
275 {
276 struct virtio_vsock_pkt_info info = {
277 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
278 .type = type,
279 .vsk = vsk,
280 };
281
282 return virtio_transport_send_pkt_info(vsk, &info);
283 }
284
285 static ssize_t
286 virtio_transport_stream_do_peek(struct vsock_sock *vsk,
287 struct msghdr *msg,
288 size_t len)
289 {
290 struct virtio_vsock_sock *vvs = vsk->trans;
291 struct virtio_vsock_pkt *pkt;
292 size_t bytes, total = 0, off;
293 int err = -EFAULT;
294
295 spin_lock_bh(&vvs->rx_lock);
296
297 list_for_each_entry(pkt, &vvs->rx_queue, list) {
298 off = pkt->off;
299
300 if (total == len)
301 break;
302
303 while (total < len && off < pkt->len) {
304 bytes = len - total;
305 if (bytes > pkt->len - off)
306 bytes = pkt->len - off;
307
308 /* sk_lock is held by caller so no one else can dequeue.
309 * Unlock rx_lock since memcpy_to_msg() may sleep.
310 */
311 spin_unlock_bh(&vvs->rx_lock);
312
313 err = memcpy_to_msg(msg, pkt->buf + off, bytes);
314 if (err)
315 goto out;
316
317 spin_lock_bh(&vvs->rx_lock);
318
319 total += bytes;
320 off += bytes;
321 }
322 }
323
324 spin_unlock_bh(&vvs->rx_lock);
325
326 return total;
327
328 out:
329 if (total)
330 err = total;
331 return err;
332 }
333
334 static ssize_t
335 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
336 struct msghdr *msg,
337 size_t len)
338 {
339 struct virtio_vsock_sock *vvs = vsk->trans;
340 struct virtio_vsock_pkt *pkt;
341 size_t bytes, total = 0;
342 u32 free_space;
343 int err = -EFAULT;
344
345 spin_lock_bh(&vvs->rx_lock);
346 while (total < len && !list_empty(&vvs->rx_queue)) {
347 pkt = list_first_entry(&vvs->rx_queue,
348 struct virtio_vsock_pkt, list);
349
350 bytes = len - total;
351 if (bytes > pkt->len - pkt->off)
352 bytes = pkt->len - pkt->off;
353
354 /* sk_lock is held by caller so no one else can dequeue.
355 * Unlock rx_lock since memcpy_to_msg() may sleep.
356 */
357 spin_unlock_bh(&vvs->rx_lock);
358
359 err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
360 if (err)
361 goto out;
362
363 spin_lock_bh(&vvs->rx_lock);
364
365 total += bytes;
366 pkt->off += bytes;
367 if (pkt->off == pkt->len) {
368 virtio_transport_dec_rx_pkt(vvs, pkt);
369 list_del(&pkt->list);
370 virtio_transport_free_pkt(pkt);
371 }
372 }
373
374 free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
375
376 spin_unlock_bh(&vvs->rx_lock);
377
378 /* To reduce the number of credit update messages,
379 * don't update credits as long as lots of space is available.
380 * Note: the limit chosen here is arbitrary. Setting the limit
381 * too high causes extra messages. Too low causes transmitter
382 * stalls. As stalls are in theory more expensive than extra
383 * messages, we set the limit to a high value. TODO: experiment
384 * with different values.
385 */
386 if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
387 virtio_transport_send_credit_update(vsk,
388 VIRTIO_VSOCK_TYPE_STREAM,
389 NULL);
390 }
391
392 return total;
393
394 out:
395 if (total)
396 err = total;
397 return err;
398 }
399
400 ssize_t
401 virtio_transport_stream_dequeue(struct vsock_sock *vsk,
402 struct msghdr *msg,
403 size_t len, int flags)
404 {
405 if (flags & MSG_PEEK)
406 return virtio_transport_stream_do_peek(vsk, msg, len);
407 else
408 return virtio_transport_stream_do_dequeue(vsk, msg, len);
409 }
410 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
411
412 int
413 virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
414 struct msghdr *msg,
415 size_t len, int flags)
416 {
417 return -EOPNOTSUPP;
418 }
419 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
420
421 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
422 {
423 struct virtio_vsock_sock *vvs = vsk->trans;
424 s64 bytes;
425
426 spin_lock_bh(&vvs->rx_lock);
427 bytes = vvs->rx_bytes;
428 spin_unlock_bh(&vvs->rx_lock);
429
430 return bytes;
431 }
432 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
433
434 static s64 virtio_transport_has_space(struct vsock_sock *vsk)
435 {
436 struct virtio_vsock_sock *vvs = vsk->trans;
437 s64 bytes;
438
439 bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
440 if (bytes < 0)
441 bytes = 0;
442
443 return bytes;
444 }
445
446 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
447 {
448 struct virtio_vsock_sock *vvs = vsk->trans;
449 s64 bytes;
450
451 spin_lock_bh(&vvs->tx_lock);
452 bytes = virtio_transport_has_space(vsk);
453 spin_unlock_bh(&vvs->tx_lock);
454
455 return bytes;
456 }
457 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
458
459 int virtio_transport_do_socket_init(struct vsock_sock *vsk,
460 struct vsock_sock *psk)
461 {
462 struct virtio_vsock_sock *vvs;
463
464 vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
465 if (!vvs)
466 return -ENOMEM;
467
468 vsk->trans = vvs;
469 vvs->vsk = vsk;
470 if (psk && psk->trans) {
471 struct virtio_vsock_sock *ptrans = psk->trans;
472
473 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
474 }
475
476 if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
477 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
478
479 vvs->buf_alloc = vsk->buffer_size;
480
481 spin_lock_init(&vvs->rx_lock);
482 spin_lock_init(&vvs->tx_lock);
483 INIT_LIST_HEAD(&vvs->rx_queue);
484
485 return 0;
486 }
487 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
488
489 /* sk_lock held by the caller */
490 void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
491 {
492 struct virtio_vsock_sock *vvs = vsk->trans;
493
494 if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
495 *val = VIRTIO_VSOCK_MAX_BUF_SIZE;
496
497 vvs->buf_alloc = *val;
498
499 virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
500 NULL);
501 }
502 EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
503
504 int
505 virtio_transport_notify_poll_in(struct vsock_sock *vsk,
506 size_t target,
507 bool *data_ready_now)
508 {
509 if (vsock_stream_has_data(vsk))
510 *data_ready_now = true;
511 else
512 *data_ready_now = false;
513
514 return 0;
515 }
516 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
517
518 int
519 virtio_transport_notify_poll_out(struct vsock_sock *vsk,
520 size_t target,
521 bool *space_avail_now)
522 {
523 s64 free_space;
524
525 free_space = vsock_stream_has_space(vsk);
526 if (free_space > 0)
527 *space_avail_now = true;
528 else if (free_space == 0)
529 *space_avail_now = false;
530
531 return 0;
532 }
533 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
534
535 int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
536 size_t target, struct vsock_transport_recv_notify_data *data)
537 {
538 return 0;
539 }
540 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
541
542 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
543 size_t target, struct vsock_transport_recv_notify_data *data)
544 {
545 return 0;
546 }
547 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
548
549 int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
550 size_t target, struct vsock_transport_recv_notify_data *data)
551 {
552 return 0;
553 }
554 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
555
556 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
557 size_t target, ssize_t copied, bool data_read,
558 struct vsock_transport_recv_notify_data *data)
559 {
560 return 0;
561 }
562 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
563
564 int virtio_transport_notify_send_init(struct vsock_sock *vsk,
565 struct vsock_transport_send_notify_data *data)
566 {
567 return 0;
568 }
569 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
570
571 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
572 struct vsock_transport_send_notify_data *data)
573 {
574 return 0;
575 }
576 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
577
578 int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
579 struct vsock_transport_send_notify_data *data)
580 {
581 return 0;
582 }
583 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
584
585 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
586 ssize_t written, struct vsock_transport_send_notify_data *data)
587 {
588 return 0;
589 }
590 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
591
592 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
593 {
594 return vsk->buffer_size;
595 }
596 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
597
598 bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
599 {
600 return true;
601 }
602 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
603
604 bool virtio_transport_stream_allow(u32 cid, u32 port)
605 {
606 return true;
607 }
608 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
609
610 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
611 struct sockaddr_vm *addr)
612 {
613 return -EOPNOTSUPP;
614 }
615 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
616
617 bool virtio_transport_dgram_allow(u32 cid, u32 port)
618 {
619 return false;
620 }
621 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
622
623 int virtio_transport_connect(struct vsock_sock *vsk)
624 {
625 struct virtio_vsock_pkt_info info = {
626 .op = VIRTIO_VSOCK_OP_REQUEST,
627 .type = VIRTIO_VSOCK_TYPE_STREAM,
628 .vsk = vsk,
629 };
630
631 return virtio_transport_send_pkt_info(vsk, &info);
632 }
633 EXPORT_SYMBOL_GPL(virtio_transport_connect);
634
635 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
636 {
637 struct virtio_vsock_pkt_info info = {
638 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
639 .type = VIRTIO_VSOCK_TYPE_STREAM,
640 .flags = (mode & RCV_SHUTDOWN ?
641 VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
642 (mode & SEND_SHUTDOWN ?
643 VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
644 .vsk = vsk,
645 };
646
647 return virtio_transport_send_pkt_info(vsk, &info);
648 }
649 EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
650
651 int
652 virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
653 struct sockaddr_vm *remote_addr,
654 struct msghdr *msg,
655 size_t dgram_len)
656 {
657 return -EOPNOTSUPP;
658 }
659 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
660
661 ssize_t
662 virtio_transport_stream_enqueue(struct vsock_sock *vsk,
663 struct msghdr *msg,
664 size_t len)
665 {
666 struct virtio_vsock_pkt_info info = {
667 .op = VIRTIO_VSOCK_OP_RW,
668 .type = VIRTIO_VSOCK_TYPE_STREAM,
669 .msg = msg,
670 .pkt_len = len,
671 .vsk = vsk,
672 };
673
674 return virtio_transport_send_pkt_info(vsk, &info);
675 }
676 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
677
678 void virtio_transport_destruct(struct vsock_sock *vsk)
679 {
680 struct virtio_vsock_sock *vvs = vsk->trans;
681
682 kfree(vvs);
683 }
684 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
685
686 static int virtio_transport_reset(struct vsock_sock *vsk,
687 struct virtio_vsock_pkt *pkt)
688 {
689 struct virtio_vsock_pkt_info info = {
690 .op = VIRTIO_VSOCK_OP_RST,
691 .type = VIRTIO_VSOCK_TYPE_STREAM,
692 .reply = !!pkt,
693 .vsk = vsk,
694 };
695
696 /* Send RST only if the original pkt is not a RST pkt */
697 if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
698 return 0;
699
700 return virtio_transport_send_pkt_info(vsk, &info);
701 }
702
703 /* Normally packets are associated with a socket. There may be no socket if an
704 * attempt was made to connect to a socket that does not exist.
705 */
706 static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
707 struct virtio_vsock_pkt *pkt)
708 {
709 struct virtio_vsock_pkt *reply;
710 struct virtio_vsock_pkt_info info = {
711 .op = VIRTIO_VSOCK_OP_RST,
712 .type = le16_to_cpu(pkt->hdr.type),
713 .reply = true,
714 };
715
716 /* Send RST only if the original pkt is not a RST pkt */
717 if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
718 return 0;
719
720 reply = virtio_transport_alloc_pkt(&info, 0,
721 le64_to_cpu(pkt->hdr.dst_cid),
722 le32_to_cpu(pkt->hdr.dst_port),
723 le64_to_cpu(pkt->hdr.src_cid),
724 le32_to_cpu(pkt->hdr.src_port));
725 if (!reply)
726 return -ENOMEM;
727
728 if (!t) {
729 virtio_transport_free_pkt(reply);
730 return -ENOTCONN;
731 }
732
733 return t->send_pkt(reply);
734 }
735
736 static void virtio_transport_wait_close(struct sock *sk, long timeout)
737 {
738 if (timeout) {
739 DEFINE_WAIT_FUNC(wait, woken_wake_function);
740
741 add_wait_queue(sk_sleep(sk), &wait);
742
743 do {
744 if (sk_wait_event(sk, &timeout,
745 sock_flag(sk, SOCK_DONE), &wait))
746 break;
747 } while (!signal_pending(current) && timeout);
748
749 remove_wait_queue(sk_sleep(sk), &wait);
750 }
751 }
752
753 static void virtio_transport_do_close(struct vsock_sock *vsk,
754 bool cancel_timeout)
755 {
756 struct sock *sk = sk_vsock(vsk);
757
758 sock_set_flag(sk, SOCK_DONE);
759 vsk->peer_shutdown = SHUTDOWN_MASK;
760 if (vsock_stream_has_data(vsk) <= 0)
761 sk->sk_state = TCP_CLOSING;
762 sk->sk_state_change(sk);
763
764 if (vsk->close_work_scheduled &&
765 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
766 vsk->close_work_scheduled = false;
767
768 vsock_remove_sock(vsk);
769
770 /* Release refcnt obtained when we scheduled the timeout */
771 sock_put(sk);
772 }
773 }
774
775 static void virtio_transport_close_timeout(struct work_struct *work)
776 {
777 struct vsock_sock *vsk =
778 container_of(work, struct vsock_sock, close_work.work);
779 struct sock *sk = sk_vsock(vsk);
780
781 sock_hold(sk);
782 lock_sock(sk);
783
784 if (!sock_flag(sk, SOCK_DONE)) {
785 (void)virtio_transport_reset(vsk, NULL);
786
787 virtio_transport_do_close(vsk, false);
788 }
789
790 vsk->close_work_scheduled = false;
791
792 release_sock(sk);
793 sock_put(sk);
794 }
795
796 /* User context, vsk->sk is locked */
797 static bool virtio_transport_close(struct vsock_sock *vsk)
798 {
799 struct sock *sk = &vsk->sk;
800
801 if (!(sk->sk_state == TCP_ESTABLISHED ||
802 sk->sk_state == TCP_CLOSING))
803 return true;
804
805 /* Already received SHUTDOWN from peer, reply with RST */
806 if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
807 (void)virtio_transport_reset(vsk, NULL);
808 return true;
809 }
810
811 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
812 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
813
814 if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
815 virtio_transport_wait_close(sk, sk->sk_lingertime);
816
817 if (sock_flag(sk, SOCK_DONE)) {
818 return true;
819 }
820
821 sock_hold(sk);
822 INIT_DELAYED_WORK(&vsk->close_work,
823 virtio_transport_close_timeout);
824 vsk->close_work_scheduled = true;
825 schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
826 return false;
827 }
828
829 void virtio_transport_release(struct vsock_sock *vsk)
830 {
831 struct virtio_vsock_sock *vvs = vsk->trans;
832 struct virtio_vsock_pkt *pkt, *tmp;
833 struct sock *sk = &vsk->sk;
834 bool remove_sock = true;
835
836 if (sk->sk_type == SOCK_STREAM)
837 remove_sock = virtio_transport_close(vsk);
838
839 list_for_each_entry_safe(pkt, tmp, &vvs->rx_queue, list) {
840 list_del(&pkt->list);
841 virtio_transport_free_pkt(pkt);
842 }
843
844 if (remove_sock)
845 vsock_remove_sock(vsk);
846 }
847 EXPORT_SYMBOL_GPL(virtio_transport_release);
848
849 static int
850 virtio_transport_recv_connecting(struct sock *sk,
851 struct virtio_vsock_pkt *pkt)
852 {
853 struct vsock_sock *vsk = vsock_sk(sk);
854 int err;
855 int skerr;
856
857 switch (le16_to_cpu(pkt->hdr.op)) {
858 case VIRTIO_VSOCK_OP_RESPONSE:
859 sk->sk_state = TCP_ESTABLISHED;
860 sk->sk_socket->state = SS_CONNECTED;
861 vsock_insert_connected(vsk);
862 sk->sk_state_change(sk);
863 break;
864 case VIRTIO_VSOCK_OP_INVALID:
865 break;
866 case VIRTIO_VSOCK_OP_RST:
867 skerr = ECONNRESET;
868 err = 0;
869 goto destroy;
870 default:
871 skerr = EPROTO;
872 err = -EINVAL;
873 goto destroy;
874 }
875 return 0;
876
877 destroy:
878 virtio_transport_reset(vsk, pkt);
879 sk->sk_state = TCP_CLOSE;
880 sk->sk_err = skerr;
881 sk->sk_error_report(sk);
882 return err;
883 }
884
885 static void
886 virtio_transport_recv_enqueue(struct vsock_sock *vsk,
887 struct virtio_vsock_pkt *pkt)
888 {
889 struct virtio_vsock_sock *vvs = vsk->trans;
890 bool can_enqueue, free_pkt = false;
891
892 pkt->len = le32_to_cpu(pkt->hdr.len);
893 pkt->off = 0;
894
895 spin_lock_bh(&vvs->rx_lock);
896
897 can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
898 if (!can_enqueue) {
899 free_pkt = true;
900 goto out;
901 }
902
903 /* Try to copy small packets into the buffer of last packet queued,
904 * to avoid wasting memory queueing the entire buffer with a small
905 * payload.
906 */
907 if (pkt->len <= GOOD_COPY_LEN && !list_empty(&vvs->rx_queue)) {
908 struct virtio_vsock_pkt *last_pkt;
909
910 last_pkt = list_last_entry(&vvs->rx_queue,
911 struct virtio_vsock_pkt, list);
912
913 /* If there is space in the last packet queued, we copy the
914 * new packet in its buffer.
915 */
916 if (pkt->len <= last_pkt->buf_len - last_pkt->len) {
917 memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
918 pkt->len);
919 last_pkt->len += pkt->len;
920 free_pkt = true;
921 goto out;
922 }
923 }
924
925 list_add_tail(&pkt->list, &vvs->rx_queue);
926
927 out:
928 spin_unlock_bh(&vvs->rx_lock);
929 if (free_pkt)
930 virtio_transport_free_pkt(pkt);
931 }
932
933 static int
934 virtio_transport_recv_connected(struct sock *sk,
935 struct virtio_vsock_pkt *pkt)
936 {
937 struct vsock_sock *vsk = vsock_sk(sk);
938 int err = 0;
939
940 switch (le16_to_cpu(pkt->hdr.op)) {
941 case VIRTIO_VSOCK_OP_RW:
942 virtio_transport_recv_enqueue(vsk, pkt);
943 sk->sk_data_ready(sk);
944 return err;
945 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
946 sk->sk_write_space(sk);
947 break;
948 case VIRTIO_VSOCK_OP_SHUTDOWN:
949 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
950 vsk->peer_shutdown |= RCV_SHUTDOWN;
951 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
952 vsk->peer_shutdown |= SEND_SHUTDOWN;
953 if (vsk->peer_shutdown == SHUTDOWN_MASK &&
954 vsock_stream_has_data(vsk) <= 0 &&
955 !sock_flag(sk, SOCK_DONE)) {
956 (void)virtio_transport_reset(vsk, NULL);
957
958 virtio_transport_do_close(vsk, true);
959 }
960 if (le32_to_cpu(pkt->hdr.flags))
961 sk->sk_state_change(sk);
962 break;
963 case VIRTIO_VSOCK_OP_RST:
964 virtio_transport_do_close(vsk, true);
965 break;
966 default:
967 err = -EINVAL;
968 break;
969 }
970
971 virtio_transport_free_pkt(pkt);
972 return err;
973 }
974
975 static void
976 virtio_transport_recv_disconnecting(struct sock *sk,
977 struct virtio_vsock_pkt *pkt)
978 {
979 struct vsock_sock *vsk = vsock_sk(sk);
980
981 if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
982 virtio_transport_do_close(vsk, true);
983 }
984
985 static int
986 virtio_transport_send_response(struct vsock_sock *vsk,
987 struct virtio_vsock_pkt *pkt)
988 {
989 struct virtio_vsock_pkt_info info = {
990 .op = VIRTIO_VSOCK_OP_RESPONSE,
991 .type = VIRTIO_VSOCK_TYPE_STREAM,
992 .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
993 .remote_port = le32_to_cpu(pkt->hdr.src_port),
994 .reply = true,
995 .vsk = vsk,
996 };
997
998 return virtio_transport_send_pkt_info(vsk, &info);
999 }
1000
1001 static bool virtio_transport_space_update(struct sock *sk,
1002 struct virtio_vsock_pkt *pkt)
1003 {
1004 struct vsock_sock *vsk = vsock_sk(sk);
1005 struct virtio_vsock_sock *vvs = vsk->trans;
1006 bool space_available;
1007
1008 /* Listener sockets are not associated with any transport, so we are
1009 * not able to take the state to see if there is space available in the
1010 * remote peer, but since they are only used to receive requests, we
1011 * can assume that there is always space available in the other peer.
1012 */
1013 if (!vvs)
1014 return true;
1015
1016 /* buf_alloc and fwd_cnt is always included in the hdr */
1017 spin_lock_bh(&vvs->tx_lock);
1018 vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
1019 vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
1020 space_available = virtio_transport_has_space(vsk);
1021 spin_unlock_bh(&vvs->tx_lock);
1022 return space_available;
1023 }
1024
1025 /* Handle server socket */
1026 static int
1027 virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
1028 struct virtio_transport *t)
1029 {
1030 struct vsock_sock *vsk = vsock_sk(sk);
1031 struct vsock_sock *vchild;
1032 struct sock *child;
1033 int ret;
1034
1035 if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
1036 virtio_transport_reset_no_sock(t, pkt);
1037 return -EINVAL;
1038 }
1039
1040 if (sk_acceptq_is_full(sk)) {
1041 virtio_transport_reset_no_sock(t, pkt);
1042 return -ENOMEM;
1043 }
1044
1045 child = vsock_create_connected(sk);
1046 if (!child) {
1047 virtio_transport_reset_no_sock(t, pkt);
1048 return -ENOMEM;
1049 }
1050
1051 sk_acceptq_added(sk);
1052
1053 lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1054
1055 child->sk_state = TCP_ESTABLISHED;
1056
1057 vchild = vsock_sk(child);
1058 vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
1059 le32_to_cpu(pkt->hdr.dst_port));
1060 vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
1061 le32_to_cpu(pkt->hdr.src_port));
1062
1063 ret = vsock_assign_transport(vchild, vsk);
1064 /* Transport assigned (looking at remote_addr) must be the same
1065 * where we received the request.
1066 */
1067 if (ret || vchild->transport != &t->transport) {
1068 release_sock(child);
1069 virtio_transport_reset_no_sock(t, pkt);
1070 sock_put(child);
1071 return ret;
1072 }
1073
1074 if (virtio_transport_space_update(child, pkt))
1075 child->sk_write_space(child);
1076
1077 vsock_insert_connected(vchild);
1078 vsock_enqueue_accept(sk, child);
1079 virtio_transport_send_response(vchild, pkt);
1080
1081 release_sock(child);
1082
1083 sk->sk_data_ready(sk);
1084 return 0;
1085 }
1086
1087 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1088 * lock.
1089 */
1090 void virtio_transport_recv_pkt(struct virtio_transport *t,
1091 struct virtio_vsock_pkt *pkt)
1092 {
1093 struct sockaddr_vm src, dst;
1094 struct vsock_sock *vsk;
1095 struct sock *sk;
1096 bool space_available;
1097
1098 vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
1099 le32_to_cpu(pkt->hdr.src_port));
1100 vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
1101 le32_to_cpu(pkt->hdr.dst_port));
1102
1103 trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1104 dst.svm_cid, dst.svm_port,
1105 le32_to_cpu(pkt->hdr.len),
1106 le16_to_cpu(pkt->hdr.type),
1107 le16_to_cpu(pkt->hdr.op),
1108 le32_to_cpu(pkt->hdr.flags),
1109 le32_to_cpu(pkt->hdr.buf_alloc),
1110 le32_to_cpu(pkt->hdr.fwd_cnt));
1111
1112 if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
1113 (void)virtio_transport_reset_no_sock(t, pkt);
1114 goto free_pkt;
1115 }
1116
1117 /* The socket must be in connected or bound table
1118 * otherwise send reset back
1119 */
1120 sk = vsock_find_connected_socket(&src, &dst);
1121 if (!sk) {
1122 sk = vsock_find_bound_socket(&dst);
1123 if (!sk) {
1124 (void)virtio_transport_reset_no_sock(t, pkt);
1125 goto free_pkt;
1126 }
1127 }
1128
1129 vsk = vsock_sk(sk);
1130
1131 space_available = virtio_transport_space_update(sk, pkt);
1132
1133 lock_sock(sk);
1134
1135 /* Update CID in case it has changed after a transport reset event */
1136 vsk->local_addr.svm_cid = dst.svm_cid;
1137
1138 if (space_available)
1139 sk->sk_write_space(sk);
1140
1141 switch (sk->sk_state) {
1142 case TCP_LISTEN:
1143 virtio_transport_recv_listen(sk, pkt, t);
1144 virtio_transport_free_pkt(pkt);
1145 break;
1146 case TCP_SYN_SENT:
1147 virtio_transport_recv_connecting(sk, pkt);
1148 virtio_transport_free_pkt(pkt);
1149 break;
1150 case TCP_ESTABLISHED:
1151 virtio_transport_recv_connected(sk, pkt);
1152 break;
1153 case TCP_CLOSING:
1154 virtio_transport_recv_disconnecting(sk, pkt);
1155 virtio_transport_free_pkt(pkt);
1156 break;
1157 default:
1158 (void)virtio_transport_reset_no_sock(t, pkt);
1159 virtio_transport_free_pkt(pkt);
1160 break;
1161 }
1162
1163 release_sock(sk);
1164
1165 /* Release refcnt obtained when we fetched this socket out of the
1166 * bound or connected list.
1167 */
1168 sock_put(sk);
1169 return;
1170
1171 free_pkt:
1172 virtio_transport_free_pkt(pkt);
1173 }
1174 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1175
1176 void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
1177 {
1178 kfree(pkt->buf);
1179 kfree(pkt);
1180 }
1181 EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
1182
1183 MODULE_LICENSE("GPL v2");
1184 MODULE_AUTHOR("Asias He");
1185 MODULE_DESCRIPTION("common code for virtio vsock");