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kpacket_gen: use constants for cmdlength
[cor.git] / net / vmw_vsock / virtio_transport_common.c
blobe5ea29c6bca7eb782c47398ebc1e3c262257238c
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.h>
15 #include <linux/virtio_ids.h>
16 #include <linux/virtio_config.h>
17 #include <linux/virtio_vsock.h>
18 #include <uapi/linux/vsockmon.h>
19
20 #include <net/sock.h>
21 #include <net/af_vsock.h>
22
23 #define CREATE_TRACE_POINTS
24 #include <trace/events/vsock_virtio_transport_common.h>
25
26 /* How long to wait for graceful shutdown of a connection */
27 #define VSOCK_CLOSE_TIMEOUT (8 * HZ)
28
29 /* Threshold for detecting small packets to copy */
30 #define GOOD_COPY_LEN 128
31
32 static const struct virtio_transport *
33 virtio_transport_get_ops(struct vsock_sock *vsk)
34 {
35 const struct vsock_transport *t = vsock_core_get_transport(vsk);
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 vsock_deliver_tap(virtio_transport_build_skb, pkt);
161 }
162 EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
163
164 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
165 struct virtio_vsock_pkt_info *info)
166 {
167 u32 src_cid, src_port, dst_cid, dst_port;
168 struct virtio_vsock_sock *vvs;
169 struct virtio_vsock_pkt *pkt;
170 u32 pkt_len = info->pkt_len;
171
172 src_cid = virtio_transport_get_ops(vsk)->transport.get_local_cid();
173 src_port = vsk->local_addr.svm_port;
174 if (!info->remote_cid) {
175 dst_cid = vsk->remote_addr.svm_cid;
176 dst_port = vsk->remote_addr.svm_port;
177 } else {
178 dst_cid = info->remote_cid;
179 dst_port = info->remote_port;
180 }
181
182 vvs = vsk->trans;
183
184 /* we can send less than pkt_len bytes */
185 if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
186 pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
187
188 /* virtio_transport_get_credit might return less than pkt_len credit */
189 pkt_len = virtio_transport_get_credit(vvs, pkt_len);
190
191 /* Do not send zero length OP_RW pkt */
192 if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
193 return pkt_len;
194
195 pkt = virtio_transport_alloc_pkt(info, pkt_len,
196 src_cid, src_port,
197 dst_cid, dst_port);
198 if (!pkt) {
199 virtio_transport_put_credit(vvs, pkt_len);
200 return -ENOMEM;
201 }
202
203 virtio_transport_inc_tx_pkt(vvs, pkt);
204
205 return virtio_transport_get_ops(vsk)->send_pkt(pkt);
206 }
207
208 static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
209 struct virtio_vsock_pkt *pkt)
210 {
211 if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
212 return false;
213
214 vvs->rx_bytes += pkt->len;
215 return true;
216 }
217
218 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
219 struct virtio_vsock_pkt *pkt)
220 {
221 vvs->rx_bytes -= pkt->len;
222 vvs->fwd_cnt += pkt->len;
223 }
224
225 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
226 {
227 spin_lock_bh(&vvs->rx_lock);
228 vvs->last_fwd_cnt = vvs->fwd_cnt;
229 pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
230 pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
231 spin_unlock_bh(&vvs->rx_lock);
232 }
233 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
234
235 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
236 {
237 u32 ret;
238
239 spin_lock_bh(&vvs->tx_lock);
240 ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
241 if (ret > credit)
242 ret = credit;
243 vvs->tx_cnt += ret;
244 spin_unlock_bh(&vvs->tx_lock);
245
246 return ret;
247 }
248 EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
249
250 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
251 {
252 spin_lock_bh(&vvs->tx_lock);
253 vvs->tx_cnt -= credit;
254 spin_unlock_bh(&vvs->tx_lock);
255 }
256 EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
257
258 static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
259 int type,
260 struct virtio_vsock_hdr *hdr)
261 {
262 struct virtio_vsock_pkt_info info = {
263 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
264 .type = type,
265 .vsk = vsk,
266 };
267
268 return virtio_transport_send_pkt_info(vsk, &info);
269 }
270
271 static ssize_t
272 virtio_transport_stream_do_peek(struct vsock_sock *vsk,
273 struct msghdr *msg,
274 size_t len)
275 {
276 struct virtio_vsock_sock *vvs = vsk->trans;
277 struct virtio_vsock_pkt *pkt;
278 size_t bytes, total = 0, off;
279 int err = -EFAULT;
280
281 spin_lock_bh(&vvs->rx_lock);
282
283 list_for_each_entry(pkt, &vvs->rx_queue, list) {
284 off = pkt->off;
285
286 if (total == len)
287 break;
288
289 while (total < len && off < pkt->len) {
290 bytes = len - total;
291 if (bytes > pkt->len - off)
292 bytes = pkt->len - off;
293
294 /* sk_lock is held by caller so no one else can dequeue.
295 * Unlock rx_lock since memcpy_to_msg() may sleep.
296 */
297 spin_unlock_bh(&vvs->rx_lock);
298
299 err = memcpy_to_msg(msg, pkt->buf + off, bytes);
300 if (err)
301 goto out;
302
303 spin_lock_bh(&vvs->rx_lock);
304
305 total += bytes;
306 off += bytes;
307 }
308 }
309
310 spin_unlock_bh(&vvs->rx_lock);
311
312 return total;
313
314 out:
315 if (total)
316 err = total;
317 return err;
318 }
319
320 static ssize_t
321 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
322 struct msghdr *msg,
323 size_t len)
324 {
325 struct virtio_vsock_sock *vvs = vsk->trans;
326 struct virtio_vsock_pkt *pkt;
327 size_t bytes, total = 0;
328 u32 free_space;
329 int err = -EFAULT;
330
331 spin_lock_bh(&vvs->rx_lock);
332 while (total < len && !list_empty(&vvs->rx_queue)) {
333 pkt = list_first_entry(&vvs->rx_queue,
334 struct virtio_vsock_pkt, list);
335
336 bytes = len - total;
337 if (bytes > pkt->len - pkt->off)
338 bytes = pkt->len - pkt->off;
339
340 /* sk_lock is held by caller so no one else can dequeue.
341 * Unlock rx_lock since memcpy_to_msg() may sleep.
342 */
343 spin_unlock_bh(&vvs->rx_lock);
344
345 err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
346 if (err)
347 goto out;
348
349 spin_lock_bh(&vvs->rx_lock);
350
351 total += bytes;
352 pkt->off += bytes;
353 if (pkt->off == pkt->len) {
354 virtio_transport_dec_rx_pkt(vvs, pkt);
355 list_del(&pkt->list);
356 virtio_transport_free_pkt(pkt);
357 }
358 }
359
360 free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
361
362 spin_unlock_bh(&vvs->rx_lock);
363
364 /* To reduce the number of credit update messages,
365 * don't update credits as long as lots of space is available.
366 * Note: the limit chosen here is arbitrary. Setting the limit
367 * too high causes extra messages. Too low causes transmitter
368 * stalls. As stalls are in theory more expensive than extra
369 * messages, we set the limit to a high value. TODO: experiment
370 * with different values.
371 */
372 if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
373 virtio_transport_send_credit_update(vsk,
374 VIRTIO_VSOCK_TYPE_STREAM,
375 NULL);
376 }
377
378 return total;
379
380 out:
381 if (total)
382 err = total;
383 return err;
384 }
385
386 ssize_t
387 virtio_transport_stream_dequeue(struct vsock_sock *vsk,
388 struct msghdr *msg,
389 size_t len, int flags)
390 {
391 if (flags & MSG_PEEK)
392 return virtio_transport_stream_do_peek(vsk, msg, len);
393 else
394 return virtio_transport_stream_do_dequeue(vsk, msg, len);
395 }
396 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
397
398 int
399 virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
400 struct msghdr *msg,
401 size_t len, int flags)
402 {
403 return -EOPNOTSUPP;
404 }
405 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
406
407 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
408 {
409 struct virtio_vsock_sock *vvs = vsk->trans;
410 s64 bytes;
411
412 spin_lock_bh(&vvs->rx_lock);
413 bytes = vvs->rx_bytes;
414 spin_unlock_bh(&vvs->rx_lock);
415
416 return bytes;
417 }
418 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
419
420 static s64 virtio_transport_has_space(struct vsock_sock *vsk)
421 {
422 struct virtio_vsock_sock *vvs = vsk->trans;
423 s64 bytes;
424
425 bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
426 if (bytes < 0)
427 bytes = 0;
428
429 return bytes;
430 }
431
432 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
433 {
434 struct virtio_vsock_sock *vvs = vsk->trans;
435 s64 bytes;
436
437 spin_lock_bh(&vvs->tx_lock);
438 bytes = virtio_transport_has_space(vsk);
439 spin_unlock_bh(&vvs->tx_lock);
440
441 return bytes;
442 }
443 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
444
445 int virtio_transport_do_socket_init(struct vsock_sock *vsk,
446 struct vsock_sock *psk)
447 {
448 struct virtio_vsock_sock *vvs;
449
450 vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
451 if (!vvs)
452 return -ENOMEM;
453
454 vsk->trans = vvs;
455 vvs->vsk = vsk;
456 if (psk && psk->trans) {
457 struct virtio_vsock_sock *ptrans = psk->trans;
458
459 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
460 }
461
462 if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
463 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
464
465 vvs->buf_alloc = vsk->buffer_size;
466
467 spin_lock_init(&vvs->rx_lock);
468 spin_lock_init(&vvs->tx_lock);
469 INIT_LIST_HEAD(&vvs->rx_queue);
470
471 return 0;
472 }
473 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
474
475 /* sk_lock held by the caller */
476 void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
477 {
478 struct virtio_vsock_sock *vvs = vsk->trans;
479
480 if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
481 *val = VIRTIO_VSOCK_MAX_BUF_SIZE;
482
483 vvs->buf_alloc = *val;
484
485 virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
486 NULL);
487 }
488 EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
489
490 int
491 virtio_transport_notify_poll_in(struct vsock_sock *vsk,
492 size_t target,
493 bool *data_ready_now)
494 {
495 if (vsock_stream_has_data(vsk))
496 *data_ready_now = true;
497 else
498 *data_ready_now = false;
499
500 return 0;
501 }
502 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
503
504 int
505 virtio_transport_notify_poll_out(struct vsock_sock *vsk,
506 size_t target,
507 bool *space_avail_now)
508 {
509 s64 free_space;
510
511 free_space = vsock_stream_has_space(vsk);
512 if (free_space > 0)
513 *space_avail_now = true;
514 else if (free_space == 0)
515 *space_avail_now = false;
516
517 return 0;
518 }
519 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
520
521 int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
522 size_t target, struct vsock_transport_recv_notify_data *data)
523 {
524 return 0;
525 }
526 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
527
528 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
529 size_t target, struct vsock_transport_recv_notify_data *data)
530 {
531 return 0;
532 }
533 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
534
535 int virtio_transport_notify_recv_pre_dequeue(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_pre_dequeue);
541
542 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
543 size_t target, ssize_t copied, bool data_read,
544 struct vsock_transport_recv_notify_data *data)
545 {
546 return 0;
547 }
548 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
549
550 int virtio_transport_notify_send_init(struct vsock_sock *vsk,
551 struct vsock_transport_send_notify_data *data)
552 {
553 return 0;
554 }
555 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
556
557 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
558 struct vsock_transport_send_notify_data *data)
559 {
560 return 0;
561 }
562 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
563
564 int virtio_transport_notify_send_pre_enqueue(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_pre_enqueue);
570
571 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
572 ssize_t written, struct vsock_transport_send_notify_data *data)
573 {
574 return 0;
575 }
576 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
577
578 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
579 {
580 return vsk->buffer_size;
581 }
582 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
583
584 bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
585 {
586 return true;
587 }
588 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
589
590 bool virtio_transport_stream_allow(u32 cid, u32 port)
591 {
592 return true;
593 }
594 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
595
596 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
597 struct sockaddr_vm *addr)
598 {
599 return -EOPNOTSUPP;
600 }
601 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
602
603 bool virtio_transport_dgram_allow(u32 cid, u32 port)
604 {
605 return false;
606 }
607 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
608
609 int virtio_transport_connect(struct vsock_sock *vsk)
610 {
611 struct virtio_vsock_pkt_info info = {
612 .op = VIRTIO_VSOCK_OP_REQUEST,
613 .type = VIRTIO_VSOCK_TYPE_STREAM,
614 .vsk = vsk,
615 };
616
617 return virtio_transport_send_pkt_info(vsk, &info);
618 }
619 EXPORT_SYMBOL_GPL(virtio_transport_connect);
620
621 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
622 {
623 struct virtio_vsock_pkt_info info = {
624 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
625 .type = VIRTIO_VSOCK_TYPE_STREAM,
626 .flags = (mode & RCV_SHUTDOWN ?
627 VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
628 (mode & SEND_SHUTDOWN ?
629 VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
630 .vsk = vsk,
631 };
632
633 return virtio_transport_send_pkt_info(vsk, &info);
634 }
635 EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
636
637 int
638 virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
639 struct sockaddr_vm *remote_addr,
640 struct msghdr *msg,
641 size_t dgram_len)
642 {
643 return -EOPNOTSUPP;
644 }
645 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
646
647 ssize_t
648 virtio_transport_stream_enqueue(struct vsock_sock *vsk,
649 struct msghdr *msg,
650 size_t len)
651 {
652 struct virtio_vsock_pkt_info info = {
653 .op = VIRTIO_VSOCK_OP_RW,
654 .type = VIRTIO_VSOCK_TYPE_STREAM,
655 .msg = msg,
656 .pkt_len = len,
657 .vsk = vsk,
658 };
659
660 return virtio_transport_send_pkt_info(vsk, &info);
661 }
662 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
663
664 void virtio_transport_destruct(struct vsock_sock *vsk)
665 {
666 struct virtio_vsock_sock *vvs = vsk->trans;
667
668 kfree(vvs);
669 }
670 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
671
672 static int virtio_transport_reset(struct vsock_sock *vsk,
673 struct virtio_vsock_pkt *pkt)
674 {
675 struct virtio_vsock_pkt_info info = {
676 .op = VIRTIO_VSOCK_OP_RST,
677 .type = VIRTIO_VSOCK_TYPE_STREAM,
678 .reply = !!pkt,
679 .vsk = vsk,
680 };
681
682 /* Send RST only if the original pkt is not a RST pkt */
683 if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
684 return 0;
685
686 return virtio_transport_send_pkt_info(vsk, &info);
687 }
688
689 /* Normally packets are associated with a socket. There may be no socket if an
690 * attempt was made to connect to a socket that does not exist.
691 */
692 static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
693 struct virtio_vsock_pkt *pkt)
694 {
695 struct virtio_vsock_pkt *reply;
696 struct virtio_vsock_pkt_info info = {
697 .op = VIRTIO_VSOCK_OP_RST,
698 .type = le16_to_cpu(pkt->hdr.type),
699 .reply = true,
700 };
701
702 /* Send RST only if the original pkt is not a RST pkt */
703 if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
704 return 0;
705
706 reply = virtio_transport_alloc_pkt(&info, 0,
707 le64_to_cpu(pkt->hdr.dst_cid),
708 le32_to_cpu(pkt->hdr.dst_port),
709 le64_to_cpu(pkt->hdr.src_cid),
710 le32_to_cpu(pkt->hdr.src_port));
711 if (!reply)
712 return -ENOMEM;
713
714 if (!t) {
715 virtio_transport_free_pkt(reply);
716 return -ENOTCONN;
717 }
718
719 return t->send_pkt(reply);
720 }
721
722 static void virtio_transport_wait_close(struct sock *sk, long timeout)
723 {
724 if (timeout) {
725 DEFINE_WAIT_FUNC(wait, woken_wake_function);
726
727 add_wait_queue(sk_sleep(sk), &wait);
728
729 do {
730 if (sk_wait_event(sk, &timeout,
731 sock_flag(sk, SOCK_DONE), &wait))
732 break;
733 } while (!signal_pending(current) && timeout);
734
735 remove_wait_queue(sk_sleep(sk), &wait);
736 }
737 }
738
739 static void virtio_transport_do_close(struct vsock_sock *vsk,
740 bool cancel_timeout)
741 {
742 struct sock *sk = sk_vsock(vsk);
743
744 sock_set_flag(sk, SOCK_DONE);
745 vsk->peer_shutdown = SHUTDOWN_MASK;
746 if (vsock_stream_has_data(vsk) <= 0)
747 sk->sk_state = TCP_CLOSING;
748 sk->sk_state_change(sk);
749
750 if (vsk->close_work_scheduled &&
751 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
752 vsk->close_work_scheduled = false;
753
754 vsock_remove_sock(vsk);
755
756 /* Release refcnt obtained when we scheduled the timeout */
757 sock_put(sk);
758 }
759 }
760
761 static void virtio_transport_close_timeout(struct work_struct *work)
762 {
763 struct vsock_sock *vsk =
764 container_of(work, struct vsock_sock, close_work.work);
765 struct sock *sk = sk_vsock(vsk);
766
767 sock_hold(sk);
768 lock_sock(sk);
769
770 if (!sock_flag(sk, SOCK_DONE)) {
771 (void)virtio_transport_reset(vsk, NULL);
772
773 virtio_transport_do_close(vsk, false);
774 }
775
776 vsk->close_work_scheduled = false;
777
778 release_sock(sk);
779 sock_put(sk);
780 }
781
782 /* User context, vsk->sk is locked */
783 static bool virtio_transport_close(struct vsock_sock *vsk)
784 {
785 struct sock *sk = &vsk->sk;
786
787 if (!(sk->sk_state == TCP_ESTABLISHED ||
788 sk->sk_state == TCP_CLOSING))
789 return true;
790
791 /* Already received SHUTDOWN from peer, reply with RST */
792 if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
793 (void)virtio_transport_reset(vsk, NULL);
794 return true;
795 }
796
797 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
798 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
799
800 if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
801 virtio_transport_wait_close(sk, sk->sk_lingertime);
802
803 if (sock_flag(sk, SOCK_DONE)) {
804 return true;
805 }
806
807 sock_hold(sk);
808 INIT_DELAYED_WORK(&vsk->close_work,
809 virtio_transport_close_timeout);
810 vsk->close_work_scheduled = true;
811 schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
812 return false;
813 }
814
815 void virtio_transport_release(struct vsock_sock *vsk)
816 {
817 struct virtio_vsock_sock *vvs = vsk->trans;
818 struct virtio_vsock_pkt *pkt, *tmp;
819 struct sock *sk = &vsk->sk;
820 bool remove_sock = true;
821
822 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
823 if (sk->sk_type == SOCK_STREAM)
824 remove_sock = virtio_transport_close(vsk);
825
826 list_for_each_entry_safe(pkt, tmp, &vvs->rx_queue, list) {
827 list_del(&pkt->list);
828 virtio_transport_free_pkt(pkt);
829 }
830 release_sock(sk);
831
832 if (remove_sock)
833 vsock_remove_sock(vsk);
834 }
835 EXPORT_SYMBOL_GPL(virtio_transport_release);
836
837 static int
838 virtio_transport_recv_connecting(struct sock *sk,
839 struct virtio_vsock_pkt *pkt)
840 {
841 struct vsock_sock *vsk = vsock_sk(sk);
842 int err;
843 int skerr;
844
845 switch (le16_to_cpu(pkt->hdr.op)) {
846 case VIRTIO_VSOCK_OP_RESPONSE:
847 sk->sk_state = TCP_ESTABLISHED;
848 sk->sk_socket->state = SS_CONNECTED;
849 vsock_insert_connected(vsk);
850 sk->sk_state_change(sk);
851 break;
852 case VIRTIO_VSOCK_OP_INVALID:
853 break;
854 case VIRTIO_VSOCK_OP_RST:
855 skerr = ECONNRESET;
856 err = 0;
857 goto destroy;
858 default:
859 skerr = EPROTO;
860 err = -EINVAL;
861 goto destroy;
862 }
863 return 0;
864
865 destroy:
866 virtio_transport_reset(vsk, pkt);
867 sk->sk_state = TCP_CLOSE;
868 sk->sk_err = skerr;
869 sk->sk_error_report(sk);
870 return err;
871 }
872
873 static void
874 virtio_transport_recv_enqueue(struct vsock_sock *vsk,
875 struct virtio_vsock_pkt *pkt)
876 {
877 struct virtio_vsock_sock *vvs = vsk->trans;
878 bool can_enqueue, free_pkt = false;
879
880 pkt->len = le32_to_cpu(pkt->hdr.len);
881 pkt->off = 0;
882
883 spin_lock_bh(&vvs->rx_lock);
884
885 can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
886 if (!can_enqueue) {
887 free_pkt = true;
888 goto out;
889 }
890
891 /* Try to copy small packets into the buffer of last packet queued,
892 * to avoid wasting memory queueing the entire buffer with a small
893 * payload.
894 */
895 if (pkt->len <= GOOD_COPY_LEN && !list_empty(&vvs->rx_queue)) {
896 struct virtio_vsock_pkt *last_pkt;
897
898 last_pkt = list_last_entry(&vvs->rx_queue,
899 struct virtio_vsock_pkt, list);
900
901 /* If there is space in the last packet queued, we copy the
902 * new packet in its buffer.
903 */
904 if (pkt->len <= last_pkt->buf_len - last_pkt->len) {
905 memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
906 pkt->len);
907 last_pkt->len += pkt->len;
908 free_pkt = true;
909 goto out;
910 }
911 }
912
913 list_add_tail(&pkt->list, &vvs->rx_queue);
914
915 out:
916 spin_unlock_bh(&vvs->rx_lock);
917 if (free_pkt)
918 virtio_transport_free_pkt(pkt);
919 }
920
921 static int
922 virtio_transport_recv_connected(struct sock *sk,
923 struct virtio_vsock_pkt *pkt)
924 {
925 struct vsock_sock *vsk = vsock_sk(sk);
926 int err = 0;
927
928 switch (le16_to_cpu(pkt->hdr.op)) {
929 case VIRTIO_VSOCK_OP_RW:
930 virtio_transport_recv_enqueue(vsk, pkt);
931 sk->sk_data_ready(sk);
932 return err;
933 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
934 sk->sk_write_space(sk);
935 break;
936 case VIRTIO_VSOCK_OP_SHUTDOWN:
937 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
938 vsk->peer_shutdown |= RCV_SHUTDOWN;
939 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
940 vsk->peer_shutdown |= SEND_SHUTDOWN;
941 if (vsk->peer_shutdown == SHUTDOWN_MASK &&
942 vsock_stream_has_data(vsk) <= 0 &&
943 !sock_flag(sk, SOCK_DONE)) {
944 (void)virtio_transport_reset(vsk, NULL);
945
946 virtio_transport_do_close(vsk, true);
947 }
948 if (le32_to_cpu(pkt->hdr.flags))
949 sk->sk_state_change(sk);
950 break;
951 case VIRTIO_VSOCK_OP_RST:
952 virtio_transport_do_close(vsk, true);
953 break;
954 default:
955 err = -EINVAL;
956 break;
957 }
958
959 virtio_transport_free_pkt(pkt);
960 return err;
961 }
962
963 static void
964 virtio_transport_recv_disconnecting(struct sock *sk,
965 struct virtio_vsock_pkt *pkt)
966 {
967 struct vsock_sock *vsk = vsock_sk(sk);
968
969 if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
970 virtio_transport_do_close(vsk, true);
971 }
972
973 static int
974 virtio_transport_send_response(struct vsock_sock *vsk,
975 struct virtio_vsock_pkt *pkt)
976 {
977 struct virtio_vsock_pkt_info info = {
978 .op = VIRTIO_VSOCK_OP_RESPONSE,
979 .type = VIRTIO_VSOCK_TYPE_STREAM,
980 .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
981 .remote_port = le32_to_cpu(pkt->hdr.src_port),
982 .reply = true,
983 .vsk = vsk,
984 };
985
986 return virtio_transport_send_pkt_info(vsk, &info);
987 }
988
989 static bool virtio_transport_space_update(struct sock *sk,
990 struct virtio_vsock_pkt *pkt)
991 {
992 struct vsock_sock *vsk = vsock_sk(sk);
993 struct virtio_vsock_sock *vvs = vsk->trans;
994 bool space_available;
995
996 /* Listener sockets are not associated with any transport, so we are
997 * not able to take the state to see if there is space available in the
998 * remote peer, but since they are only used to receive requests, we
999 * can assume that there is always space available in the other peer.
1000 */
1001 if (!vvs)
1002 return true;
1003
1004 /* buf_alloc and fwd_cnt is always included in the hdr */
1005 spin_lock_bh(&vvs->tx_lock);
1006 vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
1007 vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
1008 space_available = virtio_transport_has_space(vsk);
1009 spin_unlock_bh(&vvs->tx_lock);
1010 return space_available;
1011 }
1012
1013 /* Handle server socket */
1014 static int
1015 virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
1016 struct virtio_transport *t)
1017 {
1018 struct vsock_sock *vsk = vsock_sk(sk);
1019 struct vsock_sock *vchild;
1020 struct sock *child;
1021 int ret;
1022
1023 if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
1024 virtio_transport_reset(vsk, pkt);
1025 return -EINVAL;
1026 }
1027
1028 if (sk_acceptq_is_full(sk)) {
1029 virtio_transport_reset(vsk, pkt);
1030 return -ENOMEM;
1031 }
1032
1033 child = vsock_create_connected(sk);
1034 if (!child) {
1035 virtio_transport_reset(vsk, pkt);
1036 return -ENOMEM;
1037 }
1038
1039 sk_acceptq_added(sk);
1040
1041 lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1042
1043 child->sk_state = TCP_ESTABLISHED;
1044
1045 vchild = vsock_sk(child);
1046 vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
1047 le32_to_cpu(pkt->hdr.dst_port));
1048 vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
1049 le32_to_cpu(pkt->hdr.src_port));
1050
1051 ret = vsock_assign_transport(vchild, vsk);
1052 /* Transport assigned (looking at remote_addr) must be the same
1053 * where we received the request.
1054 */
1055 if (ret || vchild->transport != &t->transport) {
1056 release_sock(child);
1057 virtio_transport_reset(vsk, pkt);
1058 sock_put(child);
1059 return ret;
1060 }
1061
1062 if (virtio_transport_space_update(child, pkt))
1063 child->sk_write_space(child);
1064
1065 vsock_insert_connected(vchild);
1066 vsock_enqueue_accept(sk, child);
1067 virtio_transport_send_response(vchild, pkt);
1068
1069 release_sock(child);
1070
1071 sk->sk_data_ready(sk);
1072 return 0;
1073 }
1074
1075 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1076 * lock.
1077 */
1078 void virtio_transport_recv_pkt(struct virtio_transport *t,
1079 struct virtio_vsock_pkt *pkt)
1080 {
1081 struct sockaddr_vm src, dst;
1082 struct vsock_sock *vsk;
1083 struct sock *sk;
1084 bool space_available;
1085
1086 vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
1087 le32_to_cpu(pkt->hdr.src_port));
1088 vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
1089 le32_to_cpu(pkt->hdr.dst_port));
1090
1091 trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1092 dst.svm_cid, dst.svm_port,
1093 le32_to_cpu(pkt->hdr.len),
1094 le16_to_cpu(pkt->hdr.type),
1095 le16_to_cpu(pkt->hdr.op),
1096 le32_to_cpu(pkt->hdr.flags),
1097 le32_to_cpu(pkt->hdr.buf_alloc),
1098 le32_to_cpu(pkt->hdr.fwd_cnt));
1099
1100 if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
1101 (void)virtio_transport_reset_no_sock(t, pkt);
1102 goto free_pkt;
1103 }
1104
1105 /* The socket must be in connected or bound table
1106 * otherwise send reset back
1107 */
1108 sk = vsock_find_connected_socket(&src, &dst);
1109 if (!sk) {
1110 sk = vsock_find_bound_socket(&dst);
1111 if (!sk) {
1112 (void)virtio_transport_reset_no_sock(t, pkt);
1113 goto free_pkt;
1114 }
1115 }
1116
1117 vsk = vsock_sk(sk);
1118
1119 space_available = virtio_transport_space_update(sk, pkt);
1120
1121 lock_sock(sk);
1122
1123 /* Update CID in case it has changed after a transport reset event */
1124 vsk->local_addr.svm_cid = dst.svm_cid;
1125
1126 if (space_available)
1127 sk->sk_write_space(sk);
1128
1129 switch (sk->sk_state) {
1130 case TCP_LISTEN:
1131 virtio_transport_recv_listen(sk, pkt, t);
1132 virtio_transport_free_pkt(pkt);
1133 break;
1134 case TCP_SYN_SENT:
1135 virtio_transport_recv_connecting(sk, pkt);
1136 virtio_transport_free_pkt(pkt);
1137 break;
1138 case TCP_ESTABLISHED:
1139 virtio_transport_recv_connected(sk, pkt);
1140 break;
1141 case TCP_CLOSING:
1142 virtio_transport_recv_disconnecting(sk, pkt);
1143 virtio_transport_free_pkt(pkt);
1144 break;
1145 default:
1146 virtio_transport_free_pkt(pkt);
1147 break;
1148 }
1149
1150 release_sock(sk);
1151
1152 /* Release refcnt obtained when we fetched this socket out of the
1153 * bound or connected list.
1154 */
1155 sock_put(sk);
1156 return;
1157
1158 free_pkt:
1159 virtio_transport_free_pkt(pkt);
1160 }
1161 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1162
1163 void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
1164 {
1165 kfree(pkt->buf);
1166 kfree(pkt);
1167 }
1168 EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
1169
1170 MODULE_LICENSE("GPL v2");
1171 MODULE_AUTHOR("Asias He");
1172 MODULE_DESCRIPTION("common code for virtio vsock");
connection oriented routing