1 // SPDX-License-Identifier: GPL-2.0
3 #include <net/strparser.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>
13 static void handle_nonesp(struct espintcp_ctx *ctx, struct sk_buff *skb,
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);
23 skb_set_owner_r(skb, sk);
25 memset(skb->cb, 0, sizeof(skb->cb));
26 skb_queue_tail(&ctx->ike_queue, skb);
27 ctx->saved_data_ready(sk);
30 static void handle_esp(struct sk_buff *skb, struct sock *sk)
32 struct tcp_skb_cb *tcp_cb = (struct tcp_skb_cb *)skb->cb;
34 skb_reset_transport_header(skb);
36 /* restore IP CB, we need at least IP6CB->nhoff */
37 memmove(skb->cb, &tcp_cb->header, sizeof(tcp_cb->header));
40 skb->dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
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);
47 xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, TCP_ENCAP_ESPINTCP);
52 static void espintcp_rcv(struct strparser *strp, struct sk_buff *skb)
54 struct espintcp_ctx *ctx = container_of(strp, struct espintcp_ctx,
56 struct strp_msg *rxm = strp_msg(skb);
57 int len = rxm->full_len - 2;
61 /* keepalive packet? */
62 if (unlikely(len == 1)) {
65 err = skb_copy_bits(skb, rxm->offset + 2, &data, 1);
67 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
78 /* drop other short messages */
79 if (unlikely(len <= sizeof(nonesp_marker))) {
80 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
85 err = skb_copy_bits(skb, rxm->offset + 2, &nonesp_marker,
86 sizeof(nonesp_marker));
88 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINHDRERROR);
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);
100 if (pskb_trim(skb, rxm->full_len - 2) != 0) {
101 XFRM_INC_STATS(sock_net(strp->sk), LINUX_MIB_XFRMINERROR);
106 if (nonesp_marker == 0)
107 handle_nonesp(ctx, skb, strp->sk);
109 handle_esp(skb, strp->sk);
112 static int espintcp_parse(struct strparser *strp, struct sk_buff *skb)
114 struct strp_msg *rxm = strp_msg(skb);
119 if (skb->len < rxm->offset + 2)
122 err = skb_copy_bits(skb, rxm->offset, &blen, sizeof(blen));
126 len = be16_to_cpu(blen);
133 static int espintcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
134 int nonblock, int flags, int *addr_len)
136 struct espintcp_ctx *ctx = espintcp_getctx(sk);
142 flags |= nonblock ? MSG_DONTWAIT : 0;
144 skb = __skb_recv_datagram(sk, &ctx->ike_queue, flags, &off, &err);
146 if (err == -EAGAIN && sk->sk_shutdown & RCV_SHUTDOWN)
152 if (copied > skb->len)
154 else if (copied < skb->len)
155 msg->msg_flags |= MSG_TRUNC;
157 err = skb_copy_datagram_msg(skb, 0, msg, copied);
163 if (flags & MSG_TRUNC)
169 int espintcp_queue_out(struct sock *sk, struct sk_buff *skb)
171 struct espintcp_ctx *ctx = espintcp_getctx(sk);
173 if (skb_queue_len(&ctx->out_queue) >= netdev_max_backlog)
176 __skb_queue_tail(&ctx->out_queue, skb);
180 EXPORT_SYMBOL_GPL(espintcp_queue_out);
182 /* espintcp length field is 2B and length includes the length field's size */
183 #define MAX_ESPINTCP_MSG (((1 << 16) - 1) - 2)
185 static int espintcp_sendskb_locked(struct sock *sk, struct espintcp_msg *emsg,
191 ret = skb_send_sock_locked(sk, emsg->skb,
192 emsg->offset, emsg->len);
198 } while (emsg->len > 0);
200 kfree_skb(emsg->skb);
201 memset(emsg, 0, sizeof(*emsg));
206 static int espintcp_sendskmsg_locked(struct sock *sk,
207 struct espintcp_msg *emsg, int flags)
209 struct sk_msg *skmsg = &emsg->skmsg;
210 struct scatterlist *sg;
214 flags |= MSG_SENDPAGE_NOTLAST;
215 sg = &skmsg->sg.data[skmsg->sg.start];
217 size_t size = sg->length - emsg->offset;
218 int offset = sg->offset + emsg->offset;
224 flags &= ~MSG_SENDPAGE_NOTLAST;
228 ret = do_tcp_sendpages(sk, p, offset, size, flags);
230 emsg->offset = offset - sg->offset;
231 skmsg->sg.start += done;
243 sk_mem_uncharge(sk, sg->length);
247 memset(emsg, 0, sizeof(*emsg));
252 static int espintcp_push_msgs(struct sock *sk, int flags)
254 struct espintcp_ctx *ctx = espintcp_getctx(sk);
255 struct espintcp_msg *emsg = &ctx->partial;
266 err = espintcp_sendskb_locked(sk, emsg, flags);
268 err = espintcp_sendskmsg_locked(sk, emsg, flags);
269 if (err == -EAGAIN) {
271 return flags & MSG_DONTWAIT ? -EAGAIN : 0;
274 memset(emsg, 0, sizeof(*emsg));
281 int espintcp_push_skb(struct sock *sk, struct sk_buff *skb)
283 struct espintcp_ctx *ctx = espintcp_getctx(sk);
284 struct espintcp_msg *emsg = &ctx->partial;
288 if (sk->sk_state != TCP_ESTABLISHED) {
293 offset = skb_transport_offset(skb);
294 len = skb->len - offset;
296 espintcp_push_msgs(sk, 0);
303 skb_set_owner_w(skb, sk);
305 emsg->offset = offset;
309 espintcp_push_msgs(sk, 0);
313 EXPORT_SYMBOL_GPL(espintcp_push_skb);
315 static int espintcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
317 long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
318 struct espintcp_ctx *ctx = espintcp_getctx(sk);
319 struct espintcp_msg *emsg = &ctx->partial;
320 struct iov_iter pfx_iter;
321 struct kvec pfx_iov = {};
322 size_t msglen = size + 2;
326 if (msg->msg_flags & ~MSG_DONTWAIT)
329 if (size > MAX_ESPINTCP_MSG)
332 if (msg->msg_controllen)
337 err = espintcp_push_msgs(sk, msg->msg_flags & MSG_DONTWAIT);
339 if (err != -EAGAIN || !(msg->msg_flags & MSG_DONTWAIT))
344 sk_msg_init(&emsg->skmsg);
346 /* only -ENOMEM is possible since we don't coalesce */
347 err = sk_msg_alloc(sk, &emsg->skmsg, msglen, 0);
351 err = sk_stream_wait_memory(sk, &timeo);
356 *((__be16 *)buf) = cpu_to_be16(msglen);
357 pfx_iov.iov_base = buf;
358 pfx_iov.iov_len = sizeof(buf);
359 iov_iter_kvec(&pfx_iter, WRITE, &pfx_iov, 1, pfx_iov.iov_len);
361 err = sk_msg_memcopy_from_iter(sk, &pfx_iter, &emsg->skmsg,
366 err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, &emsg->skmsg, size);
370 end = emsg->skmsg.sg.end;
372 sk_msg_iter_var_prev(end);
373 sg_mark_end(sk_msg_elem(&emsg->skmsg, end));
375 tcp_rate_check_app_limited(sk);
377 err = espintcp_push_msgs(sk, msg->msg_flags & MSG_DONTWAIT);
378 /* this message could be partially sent, keep it */
385 sk_msg_free(sk, &emsg->skmsg);
386 memset(emsg, 0, sizeof(*emsg));
392 static struct proto espintcp_prot __ro_after_init;
393 static struct proto_ops espintcp_ops __ro_after_init;
394 static struct proto espintcp6_prot;
395 static struct proto_ops espintcp6_ops;
396 static DEFINE_MUTEX(tcpv6_prot_mutex);
398 static void espintcp_data_ready(struct sock *sk)
400 struct espintcp_ctx *ctx = espintcp_getctx(sk);
402 strp_data_ready(&ctx->strp);
405 static void espintcp_tx_work(struct work_struct *work)
407 struct espintcp_ctx *ctx = container_of(work,
408 struct espintcp_ctx, work);
409 struct sock *sk = ctx->strp.sk;
412 if (!ctx->tx_running)
413 espintcp_push_msgs(sk, 0);
417 static void espintcp_write_space(struct sock *sk)
419 struct espintcp_ctx *ctx = espintcp_getctx(sk);
421 schedule_work(&ctx->work);
422 ctx->saved_write_space(sk);
425 static void espintcp_destruct(struct sock *sk)
427 struct espintcp_ctx *ctx = espintcp_getctx(sk);
429 ctx->saved_destruct(sk);
433 bool tcp_is_ulp_esp(struct sock *sk)
435 return sk->sk_prot == &espintcp_prot || sk->sk_prot == &espintcp6_prot;
437 EXPORT_SYMBOL_GPL(tcp_is_ulp_esp);
439 static void build_protos(struct proto *espintcp_prot,
440 struct proto_ops *espintcp_ops,
441 const struct proto *orig_prot,
442 const struct proto_ops *orig_ops);
443 static int espintcp_init_sk(struct sock *sk)
445 struct inet_connection_sock *icsk = inet_csk(sk);
446 struct strp_callbacks cb = {
447 .rcv_msg = espintcp_rcv,
448 .parse_msg = espintcp_parse,
450 struct espintcp_ctx *ctx;
453 /* sockmap is not compatible with espintcp */
454 if (sk->sk_user_data)
457 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
461 err = strp_init(&ctx->strp, sk, &cb);
467 strp_check_rcv(&ctx->strp);
468 skb_queue_head_init(&ctx->ike_queue);
469 skb_queue_head_init(&ctx->out_queue);
471 if (sk->sk_family == AF_INET) {
472 sk->sk_prot = &espintcp_prot;
473 sk->sk_socket->ops = &espintcp_ops;
475 mutex_lock(&tcpv6_prot_mutex);
476 if (!espintcp6_prot.recvmsg)
477 build_protos(&espintcp6_prot, &espintcp6_ops, sk->sk_prot, sk->sk_socket->ops);
478 mutex_unlock(&tcpv6_prot_mutex);
480 sk->sk_prot = &espintcp6_prot;
481 sk->sk_socket->ops = &espintcp6_ops;
483 ctx->saved_data_ready = sk->sk_data_ready;
484 ctx->saved_write_space = sk->sk_write_space;
485 ctx->saved_destruct = sk->sk_destruct;
486 sk->sk_data_ready = espintcp_data_ready;
487 sk->sk_write_space = espintcp_write_space;
488 sk->sk_destruct = espintcp_destruct;
489 rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
490 INIT_WORK(&ctx->work, espintcp_tx_work);
492 /* avoid using task_frag */
493 sk->sk_allocation = GFP_ATOMIC;
502 static void espintcp_release(struct sock *sk)
504 struct espintcp_ctx *ctx = espintcp_getctx(sk);
505 struct sk_buff_head queue;
508 __skb_queue_head_init(&queue);
509 skb_queue_splice_init(&ctx->out_queue, &queue);
511 while ((skb = __skb_dequeue(&queue)))
512 espintcp_push_skb(sk, skb);
517 static void espintcp_close(struct sock *sk, long timeout)
519 struct espintcp_ctx *ctx = espintcp_getctx(sk);
520 struct espintcp_msg *emsg = &ctx->partial;
522 strp_stop(&ctx->strp);
524 sk->sk_prot = &tcp_prot;
527 cancel_work_sync(&ctx->work);
528 strp_done(&ctx->strp);
530 skb_queue_purge(&ctx->out_queue);
531 skb_queue_purge(&ctx->ike_queue);
535 kfree_skb(emsg->skb);
537 sk_msg_free(sk, &emsg->skmsg);
540 tcp_close(sk, timeout);
543 static __poll_t espintcp_poll(struct file *file, struct socket *sock,
546 __poll_t mask = datagram_poll(file, sock, wait);
547 struct sock *sk = sock->sk;
548 struct espintcp_ctx *ctx = espintcp_getctx(sk);
550 if (!skb_queue_empty(&ctx->ike_queue))
551 mask |= EPOLLIN | EPOLLRDNORM;
556 static void build_protos(struct proto *espintcp_prot,
557 struct proto_ops *espintcp_ops,
558 const struct proto *orig_prot,
559 const struct proto_ops *orig_ops)
561 memcpy(espintcp_prot, orig_prot, sizeof(struct proto));
562 memcpy(espintcp_ops, orig_ops, sizeof(struct proto_ops));
563 espintcp_prot->sendmsg = espintcp_sendmsg;
564 espintcp_prot->recvmsg = espintcp_recvmsg;
565 espintcp_prot->close = espintcp_close;
566 espintcp_prot->release_cb = espintcp_release;
567 espintcp_ops->poll = espintcp_poll;
570 static struct tcp_ulp_ops espintcp_ulp __read_mostly = {
572 .owner = THIS_MODULE,
573 .init = espintcp_init_sk,
576 void __init espintcp_init(void)
578 build_protos(&espintcp_prot, &espintcp_ops, &tcp_prot, &inet_stream_ops);
580 tcp_register_ulp(&espintcp_ulp);