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1// SPDX-License-Identifier: GPL-2.0
2#include <net/tcp.h>
3#include <net/strparser.h>
4#include <net/xfrm.h>
5#include <net/esp.h>
6#include <net/espintcp.h>
7#include <linux/skmsg.h>
8#include <net/inet_common.h>
9#if IS_ENABLED(CONFIG_IPV6)
10#include <net/ipv6_stubs.h>
11#endif
12
13static void handle_nonesp(struct espintcp_ctx *ctx, struct sk_buff *skb,
14 struct sock *sk)
15{
16 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf ||
17 !sk_rmem_schedule(sk, skb, skb->truesize)) {
18 XFRM_INC_STATS(sock_net(sk), LINUX_MIB_XFRMINERROR);
19 kfree_skb(skb);
20 return;
21 }
22
23 skb_set_owner_r(skb, sk);
24
25 memset(skb->cb, 0, sizeof(skb->cb));
26 skb_queue_tail(&ctx->ike_queue, skb);
27 ctx->saved_data_ready(sk);
28}
29
30static void handle_esp(struct sk_buff *skb, struct sock *sk)
31{
32 struct tcp_skb_cb *tcp_cb = (struct tcp_skb_cb *)skb->cb;
33
34 skb_reset_transport_header(skb);
35
36 /* restore IP CB, we need at least IP6CB->nhoff */
37 memmove(skb->cb, &tcp_cb->header, sizeof(tcp_cb->header));
38
39 rcu_read_lock();
40 skb->dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
41 local_bh_disable();
42#if IS_ENABLED(CONFIG_IPV6)
43 if (sk->sk_family == AF_INET6)
44 ipv6_stub->xfrm6_rcv_encap(skb, IPPROTO_ESP, 0, TCP_ENCAP_ESPINTCP);
45 else
46#endif
47 xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, TCP_ENCAP_ESPINTCP);
48 local_bh_enable();
49 rcu_read_unlock();
50}
51
52static void espintcp_rcv(struct strparser *strp, struct sk_buff *skb)
53{
54 struct espintcp_ctx *ctx = container_of(strp, struct espintcp_ctx,
55 strp);
56 struct strp_msg *rxm = strp_msg(skb);
57 int len = rxm->full_len - 2;
58 u32 nonesp_marker;
59 int err;
60
61 /* keepalive packet? */
62 if (unlikely(len == 1)) {
63 u8 data;
64
65 err = skb_copy_bits(skb, rxm->offset + 2, &data, 1);
66 if (err < 0) {
67 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
68 kfree_skb(skb);
69 return;
70 }
71
72 if (data == 0xff) {
73 kfree_skb(skb);
74 return;
75 }
76 }
77
78 /* drop other short messages */
79 if (unlikely(len <= sizeof(nonesp_marker))) {
80 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
81 kfree_skb(skb);
82 return;
83 }
84
85 err = skb_copy_bits(skb, rxm->offset + 2, &nonesp_marker,
86 sizeof(nonesp_marker));
87 if (err < 0) {
88 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
89 kfree_skb(skb);
90 return;
91 }
92
93 /* remove header, leave non-ESP marker/SPI */
94 if (!pskb_pull(skb, rxm->offset + 2)) {
95 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINERROR);
96 kfree_skb(skb);
97 return;
98 }
99
100 if (pskb_trim(skb, rxm->full_len - 2) != 0) {
101 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINERROR);
102 kfree_skb(skb);
103 return;
104 }
105
106 if (nonesp_marker == 0)
107 handle_nonesp(ctx, skb, strp->sk);
108 else
109 handle_esp(skb, strp->sk);
110}
111
112static int espintcp_parse(struct strparser *strp, struct sk_buff *skb)
113{
114 struct strp_msg *rxm = strp_msg(skb);
115 __be16 blen;
116 u16 len;
117 int err;
118
119 if (skb->len < rxm->offset + 2)
120 return 0;
121
122 err = skb_copy_bits(skb, rxm->offset, &blen, sizeof(blen));
123 if (err < 0)
124 return err;
125
126 len = be16_to_cpu(blen);
127 if (len < 2)
128 return -EINVAL;
129
130 return len;
131}
132
133static int espintcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
134 int flags, int *addr_len)
135{
136 struct espintcp_ctx *ctx = espintcp_getctx(sk);
137 struct sk_buff *skb;
138 int err = 0;
139 int copied;
140 int off = 0;
141
142 skb = __skb_recv_datagram(sk, &ctx->ike_queue, flags, &off, &err);
143 if (!skb) {
144 if (err == -EAGAIN && sk->sk_shutdown & RCV_SHUTDOWN)
145 return 0;
146 return err;
147 }
148
149 copied = len;
150 if (copied > skb->len)
151 copied = skb->len;
152 else if (copied < skb->len)
153 msg->msg_flags |= MSG_TRUNC;
154
155 err = skb_copy_datagram_msg(skb, 0, msg, copied);
156 if (unlikely(err)) {
157 kfree_skb(skb);
158 return err;
159 }
160
161 if (flags & MSG_TRUNC)
162 copied = skb->len;
163 kfree_skb(skb);
164 return copied;
165}
166
167int espintcp_queue_out(struct sock *sk, struct sk_buff *skb)
168{
169 struct espintcp_ctx *ctx = espintcp_getctx(sk);
170
171 if (skb_queue_len(&ctx->out_queue) >= READ_ONCE(netdev_max_backlog))
172 return -ENOBUFS;
173
174 __skb_queue_tail(&ctx->out_queue, skb);
175
176 return 0;
177}
178EXPORT_SYMBOL_GPL(espintcp_queue_out);
179
180/* espintcp length field is 2B and length includes the length field's size */
181#define MAX_ESPINTCP_MSG (((1 << 16) - 1) - 2)
182
183static int espintcp_sendskb_locked(struct sock *sk, struct espintcp_msg *emsg,
184 int flags)
185{
186 do {
187 int ret;
188
189 ret = skb_send_sock_locked(sk, emsg->skb,
190 emsg->offset, emsg->len);
191 if (ret < 0)
192 return ret;
193
194 emsg->len -= ret;
195 emsg->offset += ret;
196 } while (emsg->len > 0);
197
198 kfree_skb(emsg->skb);
199 memset(emsg, 0, sizeof(*emsg));
200
201 return 0;
202}
203
204static int espintcp_sendskmsg_locked(struct sock *sk,
205 struct espintcp_msg *emsg, int flags)
206{
207 struct sk_msg *skmsg = &emsg->skmsg;
208 struct scatterlist *sg;
209 int done = 0;
210 int ret;
211
212 flags |= MSG_SENDPAGE_NOTLAST;
213 sg = &skmsg->sg.data[skmsg->sg.start];
214 do {
215 size_t size = sg->length - emsg->offset;
216 int offset = sg->offset + emsg->offset;
217 struct page *p;
218
219 emsg->offset = 0;
220
221 if (sg_is_last(sg))
222 flags &= ~MSG_SENDPAGE_NOTLAST;
223
224 p = sg_page(sg);
225retry:
226 ret = do_tcp_sendpages(sk, p, offset, size, flags);
227 if (ret < 0) {
228 emsg->offset = offset - sg->offset;
229 skmsg->sg.start += done;
230 return ret;
231 }
232
233 if (ret != size) {
234 offset += ret;
235 size -= ret;
236 goto retry;
237 }
238
239 done++;
240 put_page(p);
241 sk_mem_uncharge(sk, sg->length);
242 sg = sg_next(sg);
243 } while (sg);
244
245 memset(emsg, 0, sizeof(*emsg));
246
247 return 0;
248}
249
250static int espintcp_push_msgs(struct sock *sk, int flags)
251{
252 struct espintcp_ctx *ctx = espintcp_getctx(sk);
253 struct espintcp_msg *emsg = &ctx->partial;
254 int err;
255
256 if (!emsg->len)
257 return 0;
258
259 if (ctx->tx_running)
260 return -EAGAIN;
261 ctx->tx_running = 1;
262
263 if (emsg->skb)
264 err = espintcp_sendskb_locked(sk, emsg, flags);
265 else
266 err = espintcp_sendskmsg_locked(sk, emsg, flags);
267 if (err == -EAGAIN) {
268 ctx->tx_running = 0;
269 return flags & MSG_DONTWAIT ? -EAGAIN : 0;
270 }
271 if (!err)
272 memset(emsg, 0, sizeof(*emsg));
273
274 ctx->tx_running = 0;
275
276 return err;
277}
278
279int espintcp_push_skb(struct sock *sk, struct sk_buff *skb)
280{
281 struct espintcp_ctx *ctx = espintcp_getctx(sk);
282 struct espintcp_msg *emsg = &ctx->partial;
283 unsigned int len;
284 int offset;
285
286 if (sk->sk_state != TCP_ESTABLISHED) {
287 kfree_skb(skb);
288 return -ECONNRESET;
289 }
290
291 offset = skb_transport_offset(skb);
292 len = skb->len - offset;
293
294 espintcp_push_msgs(sk, 0);
295
296 if (emsg->len) {
297 kfree_skb(skb);
298 return -ENOBUFS;
299 }
300
301 skb_set_owner_w(skb, sk);
302
303 emsg->offset = offset;
304 emsg->len = len;
305 emsg->skb = skb;
306
307 espintcp_push_msgs(sk, 0);
308
309 return 0;
310}
311EXPORT_SYMBOL_GPL(espintcp_push_skb);
312
313static int espintcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
314{
315 long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
316 struct espintcp_ctx *ctx = espintcp_getctx(sk);
317 struct espintcp_msg *emsg = &ctx->partial;
318 struct iov_iter pfx_iter;
319 struct kvec pfx_iov = {};
320 size_t msglen = size + 2;
321 char buf[2] = {0};
322 int err, end;
323
324 if (msg->msg_flags & ~MSG_DONTWAIT)
325 return -EOPNOTSUPP;
326
327 if (size > MAX_ESPINTCP_MSG)
328 return -EMSGSIZE;
329
330 if (msg->msg_controllen)
331 return -EOPNOTSUPP;
332
333 lock_sock(sk);
334
335 err = espintcp_push_msgs(sk, msg->msg_flags & MSG_DONTWAIT);
336 if (err < 0) {
337 if (err != -EAGAIN || !(msg->msg_flags & MSG_DONTWAIT))
338 err = -ENOBUFS;
339 goto unlock;
340 }
341
342 sk_msg_init(&emsg->skmsg);
343 while (1) {
344 /* only -ENOMEM is possible since we don't coalesce */
345 err = sk_msg_alloc(sk, &emsg->skmsg, msglen, 0);
346 if (!err)
347 break;
348
349 err = sk_stream_wait_memory(sk, &timeo);
350 if (err)
351 goto fail;
352 }
353
354 *((__be16 *)buf) = cpu_to_be16(msglen);
355 pfx_iov.iov_base = buf;
356 pfx_iov.iov_len = sizeof(buf);
357 iov_iter_kvec(&pfx_iter, ITER_SOURCE, &pfx_iov, 1, pfx_iov.iov_len);
358
359 err = sk_msg_memcopy_from_iter(sk, &pfx_iter, &emsg->skmsg,
360 pfx_iov.iov_len);
361 if (err < 0)
362 goto fail;
363
364 err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, &emsg->skmsg, size);
365 if (err < 0)
366 goto fail;
367
368 end = emsg->skmsg.sg.end;
369 emsg->len = size;
370 sk_msg_iter_var_prev(end);
371 sg_mark_end(sk_msg_elem(&emsg->skmsg, end));
372
373 tcp_rate_check_app_limited(sk);
374
375 err = espintcp_push_msgs(sk, msg->msg_flags & MSG_DONTWAIT);
376 /* this message could be partially sent, keep it */
377
378 release_sock(sk);
379
380 return size;
381
382fail:
383 sk_msg_free(sk, &emsg->skmsg);
384 memset(emsg, 0, sizeof(*emsg));
385unlock:
386 release_sock(sk);
387 return err;
388}
389
390static struct proto espintcp_prot __ro_after_init;
391static struct proto_ops espintcp_ops __ro_after_init;
392static struct proto espintcp6_prot;
393static struct proto_ops espintcp6_ops;
394static DEFINE_MUTEX(tcpv6_prot_mutex);
395
396static void espintcp_data_ready(struct sock *sk)
397{
398 struct espintcp_ctx *ctx = espintcp_getctx(sk);
399
400 strp_data_ready(&ctx->strp);
401}
402
403static void espintcp_tx_work(struct work_struct *work)
404{
405 struct espintcp_ctx *ctx = container_of(work,
406 struct espintcp_ctx, work);
407 struct sock *sk = ctx->strp.sk;
408
409 lock_sock(sk);
410 if (!ctx->tx_running)
411 espintcp_push_msgs(sk, 0);
412 release_sock(sk);
413}
414
415static void espintcp_write_space(struct sock *sk)
416{
417 struct espintcp_ctx *ctx = espintcp_getctx(sk);
418
419 schedule_work(&ctx->work);
420 ctx->saved_write_space(sk);
421}
422
423static void espintcp_destruct(struct sock *sk)
424{
425 struct espintcp_ctx *ctx = espintcp_getctx(sk);
426
427 ctx->saved_destruct(sk);
428 kfree(ctx);
429}
430
431bool tcp_is_ulp_esp(struct sock *sk)
432{
433 return sk->sk_prot == &espintcp_prot || sk->sk_prot == &espintcp6_prot;
434}
435EXPORT_SYMBOL_GPL(tcp_is_ulp_esp);
436
437static void build_protos(struct proto *espintcp_prot,
438 struct proto_ops *espintcp_ops,
439 const struct proto *orig_prot,
440 const struct proto_ops *orig_ops);
441static int espintcp_init_sk(struct sock *sk)
442{
443 struct inet_connection_sock *icsk = inet_csk(sk);
444 struct strp_callbacks cb = {
445 .rcv_msg = espintcp_rcv,
446 .parse_msg = espintcp_parse,
447 };
448 struct espintcp_ctx *ctx;
449 int err;
450
451 /* sockmap is not compatible with espintcp */
452 if (sk->sk_user_data)
453 return -EBUSY;
454
455 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
456 if (!ctx)
457 return -ENOMEM;
458
459 err = strp_init(&ctx->strp, sk, &cb);
460 if (err)
461 goto free;
462
463 __sk_dst_reset(sk);
464
465 strp_check_rcv(&ctx->strp);
466 skb_queue_head_init(&ctx->ike_queue);
467 skb_queue_head_init(&ctx->out_queue);
468
469 if (sk->sk_family == AF_INET) {
470 sk->sk_prot = &espintcp_prot;
471 sk->sk_socket->ops = &espintcp_ops;
472 } else {
473 mutex_lock(&tcpv6_prot_mutex);
474 if (!espintcp6_prot.recvmsg)
475 build_protos(&espintcp6_prot, &espintcp6_ops, sk->sk_prot, sk->sk_socket->ops);
476 mutex_unlock(&tcpv6_prot_mutex);
477
478 sk->sk_prot = &espintcp6_prot;
479 sk->sk_socket->ops = &espintcp6_ops;
480 }
481 ctx->saved_data_ready = sk->sk_data_ready;
482 ctx->saved_write_space = sk->sk_write_space;
483 ctx->saved_destruct = sk->sk_destruct;
484 sk->sk_data_ready = espintcp_data_ready;
485 sk->sk_write_space = espintcp_write_space;
486 sk->sk_destruct = espintcp_destruct;
487 rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
488 INIT_WORK(&ctx->work, espintcp_tx_work);
489
490 /* avoid using task_frag */
491 sk->sk_allocation = GFP_ATOMIC;
492 sk->sk_use_task_frag = false;
493
494 return 0;
495
496free:
497 kfree(ctx);
498 return err;
499}
500
501static void espintcp_release(struct sock *sk)
502{
503 struct espintcp_ctx *ctx = espintcp_getctx(sk);
504 struct sk_buff_head queue;
505 struct sk_buff *skb;
506
507 __skb_queue_head_init(&queue);
508 skb_queue_splice_init(&ctx->out_queue, &queue);
509
510 while ((skb = __skb_dequeue(&queue)))
511 espintcp_push_skb(sk, skb);
512
513 tcp_release_cb(sk);
514}
515
516static void espintcp_close(struct sock *sk, long timeout)
517{
518 struct espintcp_ctx *ctx = espintcp_getctx(sk);
519 struct espintcp_msg *emsg = &ctx->partial;
520
521 strp_stop(&ctx->strp);
522
523 sk->sk_prot = &tcp_prot;
524 barrier();
525
526 cancel_work_sync(&ctx->work);
527 strp_done(&ctx->strp);
528
529 skb_queue_purge(&ctx->out_queue);
530 skb_queue_purge(&ctx->ike_queue);
531
532 if (emsg->len) {
533 if (emsg->skb)
534 kfree_skb(emsg->skb);
535 else
536 sk_msg_free(sk, &emsg->skmsg);
537 }
538
539 tcp_close(sk, timeout);
540}
541
542static __poll_t espintcp_poll(struct file *file, struct socket *sock,
543 poll_table *wait)
544{
545 __poll_t mask = datagram_poll(file, sock, wait);
546 struct sock *sk = sock->sk;
547 struct espintcp_ctx *ctx = espintcp_getctx(sk);
548
549 if (!skb_queue_empty(&ctx->ike_queue))
550 mask |= EPOLLIN | EPOLLRDNORM;
551
552 return mask;
553}
554
555static void build_protos(struct proto *espintcp_prot,
556 struct proto_ops *espintcp_ops,
557 const struct proto *orig_prot,
558 const struct proto_ops *orig_ops)
559{
560 memcpy(espintcp_prot, orig_prot, sizeof(struct proto));
561 memcpy(espintcp_ops, orig_ops, sizeof(struct proto_ops));
562 espintcp_prot->sendmsg = espintcp_sendmsg;
563 espintcp_prot->recvmsg = espintcp_recvmsg;
564 espintcp_prot->close = espintcp_close;
565 espintcp_prot->release_cb = espintcp_release;
566 espintcp_ops->poll = espintcp_poll;
567}
568
569static struct tcp_ulp_ops espintcp_ulp __read_mostly = {
570 .name = "espintcp",
571 .owner = THIS_MODULE,
572 .init = espintcp_init_sk,
573};
574
575void __init espintcp_init(void)
576{
577 build_protos(&espintcp_prot, &espintcp_ops, &tcp_prot, &inet_stream_ops);
578
579 tcp_register_ulp(&espintcp_ulp);
580}
1// SPDX-License-Identifier: GPL-2.0
2#include <net/tcp.h>
3#include <net/strparser.h>
4#include <net/xfrm.h>
5#include <net/esp.h>
6#include <net/espintcp.h>
7#include <linux/skmsg.h>
8#include <net/inet_common.h>
9#include <trace/events/sock.h>
10#if IS_ENABLED(CONFIG_IPV6)
11#include <net/ipv6_stubs.h>
12#endif
13#include <net/hotdata.h>
14
15static void handle_nonesp(struct espintcp_ctx *ctx, struct sk_buff *skb,
16 struct sock *sk)
17{
18 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf ||
19 !sk_rmem_schedule(sk, skb, skb->truesize)) {
20 XFRM_INC_STATS(sock_net(sk), LINUX_MIB_XFRMINERROR);
21 kfree_skb(skb);
22 return;
23 }
24
25 skb_set_owner_r(skb, sk);
26
27 memset(skb->cb, 0, sizeof(skb->cb));
28 skb_queue_tail(&ctx->ike_queue, skb);
29 ctx->saved_data_ready(sk);
30}
31
32static void handle_esp(struct sk_buff *skb, struct sock *sk)
33{
34 struct tcp_skb_cb *tcp_cb = (struct tcp_skb_cb *)skb->cb;
35
36 skb_reset_transport_header(skb);
37
38 /* restore IP CB, we need at least IP6CB->nhoff */
39 memmove(skb->cb, &tcp_cb->header, sizeof(tcp_cb->header));
40
41 rcu_read_lock();
42 skb->dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
43 local_bh_disable();
44#if IS_ENABLED(CONFIG_IPV6)
45 if (sk->sk_family == AF_INET6)
46 ipv6_stub->xfrm6_rcv_encap(skb, IPPROTO_ESP, 0, TCP_ENCAP_ESPINTCP);
47 else
48#endif
49 xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, TCP_ENCAP_ESPINTCP);
50 local_bh_enable();
51 rcu_read_unlock();
52}
53
54static void espintcp_rcv(struct strparser *strp, struct sk_buff *skb)
55{
56 struct espintcp_ctx *ctx = container_of(strp, struct espintcp_ctx,
57 strp);
58 struct strp_msg *rxm = strp_msg(skb);
59 int len = rxm->full_len - 2;
60 u32 nonesp_marker;
61 int err;
62
63 /* keepalive packet? */
64 if (unlikely(len == 1)) {
65 u8 data;
66
67 err = skb_copy_bits(skb, rxm->offset + 2, &data, 1);
68 if (err < 0) {
69 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
70 kfree_skb(skb);
71 return;
72 }
73
74 if (data == 0xff) {
75 kfree_skb(skb);
76 return;
77 }
78 }
79
80 /* drop other short messages */
81 if (unlikely(len <= sizeof(nonesp_marker))) {
82 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
83 kfree_skb(skb);
84 return;
85 }
86
87 err = skb_copy_bits(skb, rxm->offset + 2, &nonesp_marker,
88 sizeof(nonesp_marker));
89 if (err < 0) {
90 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
91 kfree_skb(skb);
92 return;
93 }
94
95 /* remove header, leave non-ESP marker/SPI */
96 if (!pskb_pull(skb, rxm->offset + 2)) {
97 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINERROR);
98 kfree_skb(skb);
99 return;
100 }
101
102 if (pskb_trim(skb, rxm->full_len - 2) != 0) {
103 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINERROR);
104 kfree_skb(skb);
105 return;
106 }
107
108 if (nonesp_marker == 0)
109 handle_nonesp(ctx, skb, strp->sk);
110 else
111 handle_esp(skb, strp->sk);
112}
113
114static int espintcp_parse(struct strparser *strp, struct sk_buff *skb)
115{
116 struct strp_msg *rxm = strp_msg(skb);
117 __be16 blen;
118 u16 len;
119 int err;
120
121 if (skb->len < rxm->offset + 2)
122 return 0;
123
124 err = skb_copy_bits(skb, rxm->offset, &blen, sizeof(blen));
125 if (err < 0)
126 return err;
127
128 len = be16_to_cpu(blen);
129 if (len < 2)
130 return -EINVAL;
131
132 return len;
133}
134
135static int espintcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
136 int flags, int *addr_len)
137{
138 struct espintcp_ctx *ctx = espintcp_getctx(sk);
139 struct sk_buff *skb;
140 int err = 0;
141 int copied;
142 int off = 0;
143
144 skb = __skb_recv_datagram(sk, &ctx->ike_queue, flags, &off, &err);
145 if (!skb) {
146 if (err == -EAGAIN && sk->sk_shutdown & RCV_SHUTDOWN)
147 return 0;
148 return err;
149 }
150
151 copied = len;
152 if (copied > skb->len)
153 copied = skb->len;
154 else if (copied < skb->len)
155 msg->msg_flags |= MSG_TRUNC;
156
157 err = skb_copy_datagram_msg(skb, 0, msg, copied);
158 if (unlikely(err)) {
159 kfree_skb(skb);
160 return err;
161 }
162
163 if (flags & MSG_TRUNC)
164 copied = skb->len;
165 kfree_skb(skb);
166 return copied;
167}
168
169int espintcp_queue_out(struct sock *sk, struct sk_buff *skb)
170{
171 struct espintcp_ctx *ctx = espintcp_getctx(sk);
172
173 if (skb_queue_len(&ctx->out_queue) >=
174 READ_ONCE(net_hotdata.max_backlog))
175 return -ENOBUFS;
176
177 __skb_queue_tail(&ctx->out_queue, skb);
178
179 return 0;
180}
181EXPORT_SYMBOL_GPL(espintcp_queue_out);
182
183/* espintcp length field is 2B and length includes the length field's size */
184#define MAX_ESPINTCP_MSG (((1 << 16) - 1) - 2)
185
186static int espintcp_sendskb_locked(struct sock *sk, struct espintcp_msg *emsg,
187 int flags)
188{
189 do {
190 int ret;
191
192 ret = skb_send_sock_locked(sk, emsg->skb,
193 emsg->offset, emsg->len);
194 if (ret < 0)
195 return ret;
196
197 emsg->len -= ret;
198 emsg->offset += ret;
199 } while (emsg->len > 0);
200
201 kfree_skb(emsg->skb);
202 memset(emsg, 0, sizeof(*emsg));
203
204 return 0;
205}
206
207static int espintcp_sendskmsg_locked(struct sock *sk,
208 struct espintcp_msg *emsg, int flags)
209{
210 struct msghdr msghdr = {
211 .msg_flags = flags | MSG_SPLICE_PAGES | MSG_MORE,
212 };
213 struct sk_msg *skmsg = &emsg->skmsg;
214 bool more = flags & MSG_MORE;
215 struct scatterlist *sg;
216 int done = 0;
217 int ret;
218
219 sg = &skmsg->sg.data[skmsg->sg.start];
220 do {
221 struct bio_vec bvec;
222 size_t size = sg->length - emsg->offset;
223 int offset = sg->offset + emsg->offset;
224 struct page *p;
225
226 emsg->offset = 0;
227
228 if (sg_is_last(sg) && !more)
229 msghdr.msg_flags &= ~MSG_MORE;
230
231 p = sg_page(sg);
232retry:
233 bvec_set_page(&bvec, p, size, offset);
234 iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size);
235 ret = tcp_sendmsg_locked(sk, &msghdr, size);
236 if (ret < 0) {
237 emsg->offset = offset - sg->offset;
238 skmsg->sg.start += done;
239 return ret;
240 }
241
242 if (ret != size) {
243 offset += ret;
244 size -= ret;
245 goto retry;
246 }
247
248 done++;
249 put_page(p);
250 sk_mem_uncharge(sk, sg->length);
251 sg = sg_next(sg);
252 } while (sg);
253
254 memset(emsg, 0, sizeof(*emsg));
255
256 return 0;
257}
258
259static int espintcp_push_msgs(struct sock *sk, int flags)
260{
261 struct espintcp_ctx *ctx = espintcp_getctx(sk);
262 struct espintcp_msg *emsg = &ctx->partial;
263 int err;
264
265 if (!emsg->len)
266 return 0;
267
268 if (ctx->tx_running)
269 return -EAGAIN;
270 ctx->tx_running = 1;
271
272 if (emsg->skb)
273 err = espintcp_sendskb_locked(sk, emsg, flags);
274 else
275 err = espintcp_sendskmsg_locked(sk, emsg, flags);
276 if (err == -EAGAIN) {
277 ctx->tx_running = 0;
278 return flags & MSG_DONTWAIT ? -EAGAIN : 0;
279 }
280 if (!err)
281 memset(emsg, 0, sizeof(*emsg));
282
283 ctx->tx_running = 0;
284
285 return err;
286}
287
288int espintcp_push_skb(struct sock *sk, struct sk_buff *skb)
289{
290 struct espintcp_ctx *ctx = espintcp_getctx(sk);
291 struct espintcp_msg *emsg = &ctx->partial;
292 unsigned int len;
293 int offset;
294
295 if (sk->sk_state != TCP_ESTABLISHED) {
296 kfree_skb(skb);
297 return -ECONNRESET;
298 }
299
300 offset = skb_transport_offset(skb);
301 len = skb->len - offset;
302
303 espintcp_push_msgs(sk, 0);
304
305 if (emsg->len) {
306 kfree_skb(skb);
307 return -ENOBUFS;
308 }
309
310 skb_set_owner_w(skb, sk);
311
312 emsg->offset = offset;
313 emsg->len = len;
314 emsg->skb = skb;
315
316 espintcp_push_msgs(sk, 0);
317
318 return 0;
319}
320EXPORT_SYMBOL_GPL(espintcp_push_skb);
321
322static int espintcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
323{
324 long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
325 struct espintcp_ctx *ctx = espintcp_getctx(sk);
326 struct espintcp_msg *emsg = &ctx->partial;
327 struct iov_iter pfx_iter;
328 struct kvec pfx_iov = {};
329 size_t msglen = size + 2;
330 char buf[2] = {0};
331 int err, end;
332
333 if (msg->msg_flags & ~MSG_DONTWAIT)
334 return -EOPNOTSUPP;
335
336 if (size > MAX_ESPINTCP_MSG)
337 return -EMSGSIZE;
338
339 if (msg->msg_controllen)
340 return -EOPNOTSUPP;
341
342 lock_sock(sk);
343
344 err = espintcp_push_msgs(sk, msg->msg_flags & MSG_DONTWAIT);
345 if (err < 0) {
346 if (err != -EAGAIN || !(msg->msg_flags & MSG_DONTWAIT))
347 err = -ENOBUFS;
348 goto unlock;
349 }
350
351 sk_msg_init(&emsg->skmsg);
352 while (1) {
353 /* only -ENOMEM is possible since we don't coalesce */
354 err = sk_msg_alloc(sk, &emsg->skmsg, msglen, 0);
355 if (!err)
356 break;
357
358 err = sk_stream_wait_memory(sk, &timeo);
359 if (err)
360 goto fail;
361 }
362
363 *((__be16 *)buf) = cpu_to_be16(msglen);
364 pfx_iov.iov_base = buf;
365 pfx_iov.iov_len = sizeof(buf);
366 iov_iter_kvec(&pfx_iter, ITER_SOURCE, &pfx_iov, 1, pfx_iov.iov_len);
367
368 err = sk_msg_memcopy_from_iter(sk, &pfx_iter, &emsg->skmsg,
369 pfx_iov.iov_len);
370 if (err < 0)
371 goto fail;
372
373 err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, &emsg->skmsg, size);
374 if (err < 0)
375 goto fail;
376
377 end = emsg->skmsg.sg.end;
378 emsg->len = size;
379 sk_msg_iter_var_prev(end);
380 sg_mark_end(sk_msg_elem(&emsg->skmsg, end));
381
382 tcp_rate_check_app_limited(sk);
383
384 err = espintcp_push_msgs(sk, msg->msg_flags & MSG_DONTWAIT);
385 /* this message could be partially sent, keep it */
386
387 release_sock(sk);
388
389 return size;
390
391fail:
392 sk_msg_free(sk, &emsg->skmsg);
393 memset(emsg, 0, sizeof(*emsg));
394unlock:
395 release_sock(sk);
396 return err;
397}
398
399static struct proto espintcp_prot __ro_after_init;
400static struct proto_ops espintcp_ops __ro_after_init;
401static struct proto espintcp6_prot;
402static struct proto_ops espintcp6_ops;
403static DEFINE_MUTEX(tcpv6_prot_mutex);
404
405static void espintcp_data_ready(struct sock *sk)
406{
407 struct espintcp_ctx *ctx = espintcp_getctx(sk);
408
409 trace_sk_data_ready(sk);
410
411 strp_data_ready(&ctx->strp);
412}
413
414static void espintcp_tx_work(struct work_struct *work)
415{
416 struct espintcp_ctx *ctx = container_of(work,
417 struct espintcp_ctx, work);
418 struct sock *sk = ctx->strp.sk;
419
420 lock_sock(sk);
421 if (!ctx->tx_running)
422 espintcp_push_msgs(sk, 0);
423 release_sock(sk);
424}
425
426static void espintcp_write_space(struct sock *sk)
427{
428 struct espintcp_ctx *ctx = espintcp_getctx(sk);
429
430 schedule_work(&ctx->work);
431 ctx->saved_write_space(sk);
432}
433
434static void espintcp_destruct(struct sock *sk)
435{
436 struct espintcp_ctx *ctx = espintcp_getctx(sk);
437
438 ctx->saved_destruct(sk);
439 kfree(ctx);
440}
441
442bool tcp_is_ulp_esp(struct sock *sk)
443{
444 return sk->sk_prot == &espintcp_prot || sk->sk_prot == &espintcp6_prot;
445}
446EXPORT_SYMBOL_GPL(tcp_is_ulp_esp);
447
448static void build_protos(struct proto *espintcp_prot,
449 struct proto_ops *espintcp_ops,
450 const struct proto *orig_prot,
451 const struct proto_ops *orig_ops);
452static int espintcp_init_sk(struct sock *sk)
453{
454 struct inet_connection_sock *icsk = inet_csk(sk);
455 struct strp_callbacks cb = {
456 .rcv_msg = espintcp_rcv,
457 .parse_msg = espintcp_parse,
458 };
459 struct espintcp_ctx *ctx;
460 int err;
461
462 /* sockmap is not compatible with espintcp */
463 if (sk->sk_user_data)
464 return -EBUSY;
465
466 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
467 if (!ctx)
468 return -ENOMEM;
469
470 err = strp_init(&ctx->strp, sk, &cb);
471 if (err)
472 goto free;
473
474 __sk_dst_reset(sk);
475
476 strp_check_rcv(&ctx->strp);
477 skb_queue_head_init(&ctx->ike_queue);
478 skb_queue_head_init(&ctx->out_queue);
479
480 if (sk->sk_family == AF_INET) {
481 sk->sk_prot = &espintcp_prot;
482 sk->sk_socket->ops = &espintcp_ops;
483 } else {
484 mutex_lock(&tcpv6_prot_mutex);
485 if (!espintcp6_prot.recvmsg)
486 build_protos(&espintcp6_prot, &espintcp6_ops, sk->sk_prot, sk->sk_socket->ops);
487 mutex_unlock(&tcpv6_prot_mutex);
488
489 sk->sk_prot = &espintcp6_prot;
490 sk->sk_socket->ops = &espintcp6_ops;
491 }
492 ctx->saved_data_ready = sk->sk_data_ready;
493 ctx->saved_write_space = sk->sk_write_space;
494 ctx->saved_destruct = sk->sk_destruct;
495 sk->sk_data_ready = espintcp_data_ready;
496 sk->sk_write_space = espintcp_write_space;
497 sk->sk_destruct = espintcp_destruct;
498 rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
499 INIT_WORK(&ctx->work, espintcp_tx_work);
500
501 /* avoid using task_frag */
502 sk->sk_allocation = GFP_ATOMIC;
503 sk->sk_use_task_frag = false;
504
505 return 0;
506
507free:
508 kfree(ctx);
509 return err;
510}
511
512static void espintcp_release(struct sock *sk)
513{
514 struct espintcp_ctx *ctx = espintcp_getctx(sk);
515 struct sk_buff_head queue;
516 struct sk_buff *skb;
517
518 __skb_queue_head_init(&queue);
519 skb_queue_splice_init(&ctx->out_queue, &queue);
520
521 while ((skb = __skb_dequeue(&queue)))
522 espintcp_push_skb(sk, skb);
523
524 tcp_release_cb(sk);
525}
526
527static void espintcp_close(struct sock *sk, long timeout)
528{
529 struct espintcp_ctx *ctx = espintcp_getctx(sk);
530 struct espintcp_msg *emsg = &ctx->partial;
531
532 strp_stop(&ctx->strp);
533
534 sk->sk_prot = &tcp_prot;
535 barrier();
536
537 cancel_work_sync(&ctx->work);
538 strp_done(&ctx->strp);
539
540 skb_queue_purge(&ctx->out_queue);
541 skb_queue_purge(&ctx->ike_queue);
542
543 if (emsg->len) {
544 if (emsg->skb)
545 kfree_skb(emsg->skb);
546 else
547 sk_msg_free(sk, &emsg->skmsg);
548 }
549
550 tcp_close(sk, timeout);
551}
552
553static __poll_t espintcp_poll(struct file *file, struct socket *sock,
554 poll_table *wait)
555{
556 __poll_t mask = datagram_poll(file, sock, wait);
557 struct sock *sk = sock->sk;
558 struct espintcp_ctx *ctx = espintcp_getctx(sk);
559
560 if (!skb_queue_empty(&ctx->ike_queue))
561 mask |= EPOLLIN | EPOLLRDNORM;
562
563 return mask;
564}
565
566static void build_protos(struct proto *espintcp_prot,
567 struct proto_ops *espintcp_ops,
568 const struct proto *orig_prot,
569 const struct proto_ops *orig_ops)
570{
571 memcpy(espintcp_prot, orig_prot, sizeof(struct proto));
572 memcpy(espintcp_ops, orig_ops, sizeof(struct proto_ops));
573 espintcp_prot->sendmsg = espintcp_sendmsg;
574 espintcp_prot->recvmsg = espintcp_recvmsg;
575 espintcp_prot->close = espintcp_close;
576 espintcp_prot->release_cb = espintcp_release;
577 espintcp_ops->poll = espintcp_poll;
578}
579
580static struct tcp_ulp_ops espintcp_ulp __read_mostly = {
581 .name = "espintcp",
582 .owner = THIS_MODULE,
583 .init = espintcp_init_sk,
584};
585
586void __init espintcp_init(void)
587{
588 build_protos(&espintcp_prot, &espintcp_ops, &tcp_prot, &inet_stream_ops);
589
590 tcp_register_ulp(&espintcp_ulp);
591}