1 // SPDX-License-Identifier: GPL-2.0
4 * Copyright (c) 2017 - 2019, Intel Corporation.
7 #define pr_fmt(fmt) "MPTCP: " fmt
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/netdevice.h>
12 #include <linux/sched/signal.h>
13 #include <linux/atomic.h>
15 #include <net/inet_common.h>
16 #include <net/inet_hashtables.h>
17 #include <net/protocol.h>
19 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
20 #include <net/transp_v6.h>
22 #include <net/mptcp.h>
25 #define MPTCP_SAME_STATE TCP_MAX_STATES
27 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
29 struct mptcp_sock msk;
34 /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not
35 * completed yet or has failed, return the subflow socket.
36 * Otherwise return NULL.
38 static struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk)
40 if (!msk->subflow || READ_ONCE(msk->can_ack))
46 static bool __mptcp_needs_tcp_fallback(const struct mptcp_sock *msk)
48 return msk->first && !sk_is_mptcp(msk->first);
51 static struct socket *__mptcp_tcp_fallback(struct mptcp_sock *msk)
53 sock_owned_by_me((const struct sock *)msk);
55 if (likely(!__mptcp_needs_tcp_fallback(msk)))
59 release_sock((struct sock *)msk);
66 static bool __mptcp_can_create_subflow(const struct mptcp_sock *msk)
71 static struct socket *__mptcp_socket_create(struct mptcp_sock *msk, int state)
73 struct mptcp_subflow_context *subflow;
74 struct sock *sk = (struct sock *)msk;
78 ssock = __mptcp_nmpc_socket(msk);
82 if (!__mptcp_can_create_subflow(msk))
83 return ERR_PTR(-EINVAL);
85 err = mptcp_subflow_create_socket(sk, &ssock);
89 msk->first = ssock->sk;
91 subflow = mptcp_subflow_ctx(ssock->sk);
92 list_add(&subflow->node, &msk->conn_list);
93 subflow->request_mptcp = 1;
96 if (state != MPTCP_SAME_STATE)
97 inet_sk_state_store(sk, state);
101 static struct sock *mptcp_subflow_get(const struct mptcp_sock *msk)
103 struct mptcp_subflow_context *subflow;
105 sock_owned_by_me((const struct sock *)msk);
107 mptcp_for_each_subflow(msk, subflow) {
108 return mptcp_subflow_tcp_sock(subflow);
114 static bool mptcp_ext_cache_refill(struct mptcp_sock *msk)
116 if (!msk->cached_ext)
117 msk->cached_ext = __skb_ext_alloc();
119 return !!msk->cached_ext;
122 static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
124 struct mptcp_subflow_context *subflow;
125 struct sock *sk = (struct sock *)msk;
127 sock_owned_by_me(sk);
129 mptcp_for_each_subflow(msk, subflow) {
130 if (subflow->data_avail)
131 return mptcp_subflow_tcp_sock(subflow);
137 static inline bool mptcp_skb_can_collapse_to(const struct mptcp_sock *msk,
138 const struct sk_buff *skb,
139 const struct mptcp_ext *mpext)
141 if (!tcp_skb_can_collapse_to(skb))
144 /* can collapse only if MPTCP level sequence is in order */
145 return mpext && mpext->data_seq + mpext->data_len == msk->write_seq;
148 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
149 struct msghdr *msg, long *timeo, int *pmss_now,
152 int mss_now, avail_size, size_goal, ret;
153 struct mptcp_sock *msk = mptcp_sk(sk);
154 struct mptcp_ext *mpext = NULL;
155 struct sk_buff *skb, *tail;
156 bool can_collapse = false;
157 struct page_frag *pfrag;
160 /* use the mptcp page cache so that we can easily move the data
161 * from one substream to another, but do per subflow memory accounting
163 pfrag = sk_page_frag(sk);
164 while (!sk_page_frag_refill(ssk, pfrag) ||
165 !mptcp_ext_cache_refill(msk)) {
166 ret = sk_stream_wait_memory(ssk, timeo);
169 if (unlikely(__mptcp_needs_tcp_fallback(msk)))
173 /* compute copy limit */
174 mss_now = tcp_send_mss(ssk, &size_goal, msg->msg_flags);
176 *ps_goal = size_goal;
177 avail_size = size_goal;
178 skb = tcp_write_queue_tail(ssk);
180 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
182 /* Limit the write to the size available in the
183 * current skb, if any, so that we create at most a new skb.
184 * Explicitly tells TCP internals to avoid collapsing on later
185 * queue management operation, to avoid breaking the ext <->
186 * SSN association set here
188 can_collapse = (size_goal - skb->len > 0) &&
189 mptcp_skb_can_collapse_to(msk, skb, mpext);
191 TCP_SKB_CB(skb)->eor = 1;
193 avail_size = size_goal - skb->len;
195 psize = min_t(size_t, pfrag->size - pfrag->offset, avail_size);
198 pr_debug("left=%zu", msg_data_left(msg));
199 psize = copy_page_from_iter(pfrag->page, pfrag->offset,
200 min_t(size_t, msg_data_left(msg), psize),
202 pr_debug("left=%zu", msg_data_left(msg));
206 /* tell the TCP stack to delay the push so that we can safely
207 * access the skb after the sendpages call
209 ret = do_tcp_sendpages(ssk, pfrag->page, pfrag->offset, psize,
210 msg->msg_flags | MSG_SENDPAGE_NOTLAST);
213 if (unlikely(ret < psize))
214 iov_iter_revert(&msg->msg_iter, psize - ret);
216 /* if the tail skb extension is still the cached one, collapsing
217 * really happened. Note: we can't check for 'same skb' as the sk_buff
218 * hdr on tail can be transmitted, freed and re-allocated by the
219 * do_tcp_sendpages() call
221 tail = tcp_write_queue_tail(ssk);
222 if (mpext && tail && mpext == skb_ext_find(tail, SKB_EXT_MPTCP)) {
223 WARN_ON_ONCE(!can_collapse);
224 mpext->data_len += ret;
228 skb = tcp_write_queue_tail(ssk);
229 mpext = __skb_ext_set(skb, SKB_EXT_MPTCP, msk->cached_ext);
230 msk->cached_ext = NULL;
232 memset(mpext, 0, sizeof(*mpext));
233 mpext->data_seq = msk->write_seq;
234 mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq;
235 mpext->data_len = ret;
239 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d",
240 mpext->data_seq, mpext->subflow_seq, mpext->data_len,
244 pfrag->offset += ret;
245 msk->write_seq += ret;
246 mptcp_subflow_ctx(ssk)->rel_write_seq += ret;
251 static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk)
255 if (likely(sk_stream_is_writeable(ssk)))
258 sock = READ_ONCE(ssk->sk_socket);
261 clear_bit(MPTCP_SEND_SPACE, &msk->flags);
262 smp_mb__after_atomic();
263 /* set NOSPACE only after clearing SEND_SPACE flag */
264 set_bit(SOCK_NOSPACE, &sock->flags);
268 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
270 int mss_now = 0, size_goal = 0, ret = 0;
271 struct mptcp_sock *msk = mptcp_sk(sk);
272 struct socket *ssock;
277 if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
281 ssock = __mptcp_tcp_fallback(msk);
282 if (unlikely(ssock)) {
284 pr_debug("fallback passthrough");
285 ret = sock_sendmsg(ssock, msg);
286 return ret >= 0 ? ret + copied : (copied ? copied : ret);
289 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
291 ssk = mptcp_subflow_get(msk);
297 pr_debug("conn_list->subflow=%p", ssk);
300 while (msg_data_left(msg)) {
301 ret = mptcp_sendmsg_frag(sk, ssk, msg, &timeo, &mss_now,
305 if (ret == 0 && unlikely(__mptcp_needs_tcp_fallback(msk))) {
307 ssock = __mptcp_tcp_fallback(msk);
316 tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle,
320 ssk_check_wmem(msk, ssk);
326 int mptcp_read_actor(read_descriptor_t *desc, struct sk_buff *skb,
327 unsigned int offset, size_t len)
329 struct mptcp_read_arg *arg = desc->arg.data;
332 copy_len = min(desc->count, len);
334 if (likely(arg->msg)) {
337 err = skb_copy_datagram_msg(skb, offset, arg->msg, copy_len);
339 pr_debug("error path");
344 pr_debug("Flushing skb payload");
347 desc->count -= copy_len;
349 pr_debug("consumed %zu bytes, %zu left", copy_len, desc->count);
353 static void mptcp_wait_data(struct sock *sk, long *timeo)
355 DEFINE_WAIT_FUNC(wait, woken_wake_function);
356 struct mptcp_sock *msk = mptcp_sk(sk);
358 add_wait_queue(sk_sleep(sk), &wait);
359 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
361 sk_wait_event(sk, timeo,
362 test_and_clear_bit(MPTCP_DATA_READY, &msk->flags), &wait);
364 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
365 remove_wait_queue(sk_sleep(sk), &wait);
368 static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
369 int nonblock, int flags, int *addr_len)
371 struct mptcp_sock *msk = mptcp_sk(sk);
372 struct mptcp_subflow_context *subflow;
373 bool more_data_avail = false;
374 struct mptcp_read_arg arg;
375 read_descriptor_t desc;
376 bool wait_data = false;
377 struct socket *ssock;
385 if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT))
389 ssock = __mptcp_tcp_fallback(msk);
390 if (unlikely(ssock)) {
392 pr_debug("fallback-read subflow=%p",
393 mptcp_subflow_ctx(ssock->sk));
394 copied = sock_recvmsg(ssock, msg, flags);
399 desc.arg.data = &arg;
402 timeo = sock_rcvtimeo(sk, nonblock);
404 len = min_t(size_t, len, INT_MAX);
405 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
411 ssk = mptcp_subflow_recv_lookup(msk);
412 pr_debug("msk=%p ssk=%p", msk, ssk);
416 subflow = mptcp_subflow_ctx(ssk);
421 /* try to read as much data as available */
422 map_remaining = subflow->map_data_len -
423 mptcp_subflow_get_map_offset(subflow);
424 desc.count = min_t(size_t, len - copied, map_remaining);
425 pr_debug("reading %zu bytes, copied %d", desc.count,
427 bytes_read = tcp_read_sock(ssk, &desc,
429 if (bytes_read < 0) {
436 pr_debug("msk ack_seq=%llx -> %llx", msk->ack_seq,
437 msk->ack_seq + bytes_read);
438 msk->ack_seq += bytes_read;
439 copied += bytes_read;
444 if (tp->urg_data && tp->urg_seq == tp->copied_seq) {
445 pr_err("Urgent data present, cannot proceed");
450 more_data_avail = mptcp_subflow_data_available(ssk);
451 } while (more_data_avail && !done);
456 more_data_avail = false;
458 /* only the master socket status is relevant here. The exit
459 * conditions mirror closely tcp_recvmsg()
461 if (copied >= target)
466 sk->sk_state == TCP_CLOSE ||
467 (sk->sk_shutdown & RCV_SHUTDOWN) ||
469 signal_pending(current))
473 copied = sock_error(sk);
477 if (sk->sk_shutdown & RCV_SHUTDOWN)
480 if (sk->sk_state == TCP_CLOSE) {
490 if (signal_pending(current)) {
491 copied = sock_intr_errno(timeo);
496 pr_debug("block timeout %ld", timeo);
498 mptcp_wait_data(sk, &timeo);
499 if (unlikely(__mptcp_tcp_fallback(msk)))
503 if (more_data_avail) {
504 if (!test_bit(MPTCP_DATA_READY, &msk->flags))
505 set_bit(MPTCP_DATA_READY, &msk->flags);
506 } else if (!wait_data) {
507 clear_bit(MPTCP_DATA_READY, &msk->flags);
509 /* .. race-breaker: ssk might get new data after last
510 * data_available() returns false.
512 ssk = mptcp_subflow_recv_lookup(msk);
514 set_bit(MPTCP_DATA_READY, &msk->flags);
521 /* subflow sockets can be either outgoing (connect) or incoming
524 * Outgoing subflows use in-kernel sockets.
525 * Incoming subflows do not have their own 'struct socket' allocated,
526 * so we need to use tcp_close() after detaching them from the mptcp
529 static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
530 struct mptcp_subflow_context *subflow,
533 struct socket *sock = READ_ONCE(ssk->sk_socket);
535 list_del(&subflow->node);
537 if (sock && sock != sk->sk_socket) {
538 /* outgoing subflow */
541 /* incoming subflow */
542 tcp_close(ssk, timeout);
546 static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu)
551 static int __mptcp_init_sock(struct sock *sk)
553 struct mptcp_sock *msk = mptcp_sk(sk);
555 INIT_LIST_HEAD(&msk->conn_list);
556 __set_bit(MPTCP_SEND_SPACE, &msk->flags);
559 inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
564 static int mptcp_init_sock(struct sock *sk)
566 if (!mptcp_is_enabled(sock_net(sk)))
569 return __mptcp_init_sock(sk);
572 static void mptcp_subflow_shutdown(struct sock *ssk, int how)
576 switch (ssk->sk_state) {
578 if (!(how & RCV_SHUTDOWN))
582 tcp_disconnect(ssk, O_NONBLOCK);
585 ssk->sk_shutdown |= how;
586 tcp_shutdown(ssk, how);
590 /* Wake up anyone sleeping in poll. */
591 ssk->sk_state_change(ssk);
595 /* Called with msk lock held, releases such lock before returning */
596 static void mptcp_close(struct sock *sk, long timeout)
598 struct mptcp_subflow_context *subflow, *tmp;
599 struct mptcp_sock *msk = mptcp_sk(sk);
600 LIST_HEAD(conn_list);
604 mptcp_token_destroy(msk->token);
605 inet_sk_state_store(sk, TCP_CLOSE);
607 list_splice_init(&msk->conn_list, &conn_list);
611 list_for_each_entry_safe(subflow, tmp, &conn_list, node) {
612 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
614 __mptcp_close_ssk(sk, ssk, subflow, timeout);
617 sk_common_release(sk);
620 static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
622 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
623 const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
624 struct ipv6_pinfo *msk6 = inet6_sk(msk);
626 msk->sk_v6_daddr = ssk->sk_v6_daddr;
627 msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;
630 msk6->saddr = ssk6->saddr;
631 msk6->flow_label = ssk6->flow_label;
635 inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num;
636 inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport;
637 inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport;
638 inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr;
639 inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr;
640 inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr;
643 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
644 static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
646 unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);
648 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
652 static struct sock *mptcp_sk_clone_lock(const struct sock *sk)
654 struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC);
659 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
660 if (nsk->sk_family == AF_INET6)
661 inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk);
667 static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
670 struct mptcp_sock *msk = mptcp_sk(sk);
671 struct socket *listener;
674 listener = __mptcp_nmpc_socket(msk);
675 if (WARN_ON_ONCE(!listener)) {
680 pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));
681 newsk = inet_csk_accept(listener->sk, flags, err, kern);
685 pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk));
687 if (sk_is_mptcp(newsk)) {
688 struct mptcp_subflow_context *subflow;
689 struct sock *new_mptcp_sock;
690 struct sock *ssk = newsk;
693 subflow = mptcp_subflow_ctx(newsk);
697 new_mptcp_sock = mptcp_sk_clone_lock(sk);
698 if (!new_mptcp_sock) {
702 mptcp_subflow_shutdown(newsk, SHUT_RDWR + 1);
707 __mptcp_init_sock(new_mptcp_sock);
709 msk = mptcp_sk(new_mptcp_sock);
710 msk->local_key = subflow->local_key;
711 msk->token = subflow->token;
715 mptcp_token_update_accept(newsk, new_mptcp_sock);
717 msk->write_seq = subflow->idsn + 1;
718 if (subflow->can_ack) {
720 msk->remote_key = subflow->remote_key;
721 mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq);
723 msk->ack_seq = ack_seq;
725 newsk = new_mptcp_sock;
726 mptcp_copy_inaddrs(newsk, ssk);
727 list_add(&subflow->node, &msk->conn_list);
729 /* will be fully established at mptcp_stream_accept()
732 inet_sk_state_store(new_mptcp_sock, TCP_SYN_RECV);
733 bh_unlock_sock(new_mptcp_sock);
737 /* the subflow can already receive packet, avoid racing with
738 * the receive path and process the pending ones
741 subflow->rel_write_seq = 1;
742 subflow->tcp_sock = ssk;
743 subflow->conn = new_mptcp_sock;
744 if (unlikely(!skb_queue_empty(&ssk->sk_receive_queue)))
745 mptcp_subflow_data_available(ssk);
752 static void mptcp_destroy(struct sock *sk)
754 struct mptcp_sock *msk = mptcp_sk(sk);
757 __skb_ext_put(msk->cached_ext);
760 static int mptcp_setsockopt(struct sock *sk, int level, int optname,
761 char __user *optval, unsigned int optlen)
763 struct mptcp_sock *msk = mptcp_sk(sk);
764 struct socket *ssock;
766 pr_debug("msk=%p", msk);
768 /* @@ the meaning of setsockopt() when the socket is connected and
769 * there are multiple subflows is not yet defined. It is up to the
770 * MPTCP-level socket to configure the subflows until the subflow
771 * is in TCP fallback, when TCP socket options are passed through
772 * to the one remaining subflow.
775 ssock = __mptcp_tcp_fallback(msk);
777 return tcp_setsockopt(ssock->sk, level, optname, optval,
785 static int mptcp_getsockopt(struct sock *sk, int level, int optname,
786 char __user *optval, int __user *option)
788 struct mptcp_sock *msk = mptcp_sk(sk);
789 struct socket *ssock;
791 pr_debug("msk=%p", msk);
793 /* @@ the meaning of setsockopt() when the socket is connected and
794 * there are multiple subflows is not yet defined. It is up to the
795 * MPTCP-level socket to configure the subflows until the subflow
796 * is in TCP fallback, when socket options are passed through
797 * to the one remaining subflow.
800 ssock = __mptcp_tcp_fallback(msk);
802 return tcp_getsockopt(ssock->sk, level, optname, optval,
810 static int mptcp_get_port(struct sock *sk, unsigned short snum)
812 struct mptcp_sock *msk = mptcp_sk(sk);
813 struct socket *ssock;
815 ssock = __mptcp_nmpc_socket(msk);
816 pr_debug("msk=%p, subflow=%p", msk, ssock);
817 if (WARN_ON_ONCE(!ssock))
820 return inet_csk_get_port(ssock->sk, snum);
823 void mptcp_finish_connect(struct sock *ssk)
825 struct mptcp_subflow_context *subflow;
826 struct mptcp_sock *msk;
830 subflow = mptcp_subflow_ctx(ssk);
832 if (!subflow->mp_capable)
838 pr_debug("msk=%p, token=%u", sk, subflow->token);
840 mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq);
842 subflow->map_seq = ack_seq;
843 subflow->map_subflow_seq = 1;
844 subflow->rel_write_seq = 1;
846 /* the socket is not connected yet, no msk/subflow ops can access/race
847 * accessing the field below
849 WRITE_ONCE(msk->remote_key, subflow->remote_key);
850 WRITE_ONCE(msk->local_key, subflow->local_key);
851 WRITE_ONCE(msk->token, subflow->token);
852 WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
853 WRITE_ONCE(msk->ack_seq, ack_seq);
854 WRITE_ONCE(msk->can_ack, 1);
857 static void mptcp_sock_graft(struct sock *sk, struct socket *parent)
859 write_lock_bh(&sk->sk_callback_lock);
860 rcu_assign_pointer(sk->sk_wq, &parent->wq);
861 sk_set_socket(sk, parent);
862 sk->sk_uid = SOCK_INODE(parent)->i_uid;
863 write_unlock_bh(&sk->sk_callback_lock);
866 static bool mptcp_memory_free(const struct sock *sk, int wake)
868 struct mptcp_sock *msk = mptcp_sk(sk);
870 return wake ? test_bit(MPTCP_SEND_SPACE, &msk->flags) : true;
873 static struct proto mptcp_prot = {
875 .owner = THIS_MODULE,
876 .init = mptcp_init_sock,
877 .close = mptcp_close,
878 .accept = mptcp_accept,
879 .setsockopt = mptcp_setsockopt,
880 .getsockopt = mptcp_getsockopt,
881 .shutdown = tcp_shutdown,
882 .destroy = mptcp_destroy,
883 .sendmsg = mptcp_sendmsg,
884 .recvmsg = mptcp_recvmsg,
886 .unhash = inet_unhash,
887 .get_port = mptcp_get_port,
888 .stream_memory_free = mptcp_memory_free,
889 .obj_size = sizeof(struct mptcp_sock),
893 static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
895 struct mptcp_sock *msk = mptcp_sk(sock->sk);
896 struct socket *ssock;
900 ssock = __mptcp_socket_create(msk, MPTCP_SAME_STATE);
902 err = PTR_ERR(ssock);
906 err = ssock->ops->bind(ssock, uaddr, addr_len);
908 mptcp_copy_inaddrs(sock->sk, ssock->sk);
911 release_sock(sock->sk);
915 static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
916 int addr_len, int flags)
918 struct mptcp_sock *msk = mptcp_sk(sock->sk);
919 struct socket *ssock;
923 ssock = __mptcp_socket_create(msk, TCP_SYN_SENT);
925 err = PTR_ERR(ssock);
929 #ifdef CONFIG_TCP_MD5SIG
930 /* no MPTCP if MD5SIG is enabled on this socket or we may run out of
933 if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
934 mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0;
937 err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
938 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
939 mptcp_copy_inaddrs(sock->sk, ssock->sk);
942 release_sock(sock->sk);
946 static int mptcp_v4_getname(struct socket *sock, struct sockaddr *uaddr,
949 if (sock->sk->sk_prot == &tcp_prot) {
950 /* we are being invoked from __sys_accept4, after
951 * mptcp_accept() has just accepted a non-mp-capable
952 * flow: sk is a tcp_sk, not an mptcp one.
954 * Hand the socket over to tcp so all further socket ops
957 sock->ops = &inet_stream_ops;
960 return inet_getname(sock, uaddr, peer);
963 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
964 static int mptcp_v6_getname(struct socket *sock, struct sockaddr *uaddr,
967 if (sock->sk->sk_prot == &tcpv6_prot) {
968 /* we are being invoked from __sys_accept4 after
969 * mptcp_accept() has accepted a non-mp-capable
970 * subflow: sk is a tcp_sk, not mptcp.
972 * Hand the socket over to tcp so all further
973 * socket ops bypass mptcp.
975 sock->ops = &inet6_stream_ops;
978 return inet6_getname(sock, uaddr, peer);
982 static int mptcp_listen(struct socket *sock, int backlog)
984 struct mptcp_sock *msk = mptcp_sk(sock->sk);
985 struct socket *ssock;
988 pr_debug("msk=%p", msk);
991 ssock = __mptcp_socket_create(msk, TCP_LISTEN);
993 err = PTR_ERR(ssock);
997 err = ssock->ops->listen(ssock, backlog);
998 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
1000 mptcp_copy_inaddrs(sock->sk, ssock->sk);
1003 release_sock(sock->sk);
1007 static bool is_tcp_proto(const struct proto *p)
1009 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1010 return p == &tcp_prot || p == &tcpv6_prot;
1012 return p == &tcp_prot;
1016 static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
1017 int flags, bool kern)
1019 struct mptcp_sock *msk = mptcp_sk(sock->sk);
1020 struct socket *ssock;
1023 pr_debug("msk=%p", msk);
1025 lock_sock(sock->sk);
1026 if (sock->sk->sk_state != TCP_LISTEN)
1029 ssock = __mptcp_nmpc_socket(msk);
1033 sock_hold(ssock->sk);
1034 release_sock(sock->sk);
1036 err = ssock->ops->accept(sock, newsock, flags, kern);
1037 if (err == 0 && !is_tcp_proto(newsock->sk->sk_prot)) {
1038 struct mptcp_sock *msk = mptcp_sk(newsock->sk);
1039 struct mptcp_subflow_context *subflow;
1041 /* set ssk->sk_socket of accept()ed flows to mptcp socket.
1042 * This is needed so NOSPACE flag can be set from tcp stack.
1044 list_for_each_entry(subflow, &msk->conn_list, node) {
1045 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
1047 if (!ssk->sk_socket)
1048 mptcp_sock_graft(ssk, newsock);
1051 inet_sk_state_store(newsock->sk, TCP_ESTABLISHED);
1054 sock_put(ssock->sk);
1058 release_sock(sock->sk);
1062 static __poll_t mptcp_poll(struct file *file, struct socket *sock,
1063 struct poll_table_struct *wait)
1065 struct sock *sk = sock->sk;
1066 struct mptcp_sock *msk;
1067 struct socket *ssock;
1072 ssock = __mptcp_nmpc_socket(msk);
1074 mask = ssock->ops->poll(file, ssock, wait);
1080 sock_poll_wait(file, sock, wait);
1082 ssock = __mptcp_tcp_fallback(msk);
1083 if (unlikely(ssock))
1084 return ssock->ops->poll(file, ssock, NULL);
1086 if (test_bit(MPTCP_DATA_READY, &msk->flags))
1087 mask = EPOLLIN | EPOLLRDNORM;
1088 if (sk_stream_is_writeable(sk) &&
1089 test_bit(MPTCP_SEND_SPACE, &msk->flags))
1090 mask |= EPOLLOUT | EPOLLWRNORM;
1091 if (sk->sk_shutdown & RCV_SHUTDOWN)
1092 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
1099 static int mptcp_shutdown(struct socket *sock, int how)
1101 struct mptcp_sock *msk = mptcp_sk(sock->sk);
1102 struct mptcp_subflow_context *subflow;
1105 pr_debug("sk=%p, how=%d", msk, how);
1107 lock_sock(sock->sk);
1109 if (how == SHUT_WR || how == SHUT_RDWR)
1110 inet_sk_state_store(sock->sk, TCP_FIN_WAIT1);
1114 if ((how & ~SHUTDOWN_MASK) || !how) {
1119 if (sock->state == SS_CONNECTING) {
1120 if ((1 << sock->sk->sk_state) &
1121 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
1122 sock->state = SS_DISCONNECTING;
1124 sock->state = SS_CONNECTED;
1127 mptcp_for_each_subflow(msk, subflow) {
1128 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
1130 mptcp_subflow_shutdown(tcp_sk, how);
1134 release_sock(sock->sk);
1139 static const struct proto_ops mptcp_stream_ops = {
1141 .owner = THIS_MODULE,
1142 .release = inet_release,
1144 .connect = mptcp_stream_connect,
1145 .socketpair = sock_no_socketpair,
1146 .accept = mptcp_stream_accept,
1147 .getname = mptcp_v4_getname,
1149 .ioctl = inet_ioctl,
1150 .gettstamp = sock_gettstamp,
1151 .listen = mptcp_listen,
1152 .shutdown = mptcp_shutdown,
1153 .setsockopt = sock_common_setsockopt,
1154 .getsockopt = sock_common_getsockopt,
1155 .sendmsg = inet_sendmsg,
1156 .recvmsg = inet_recvmsg,
1157 .mmap = sock_no_mmap,
1158 .sendpage = inet_sendpage,
1159 #ifdef CONFIG_COMPAT
1160 .compat_setsockopt = compat_sock_common_setsockopt,
1161 .compat_getsockopt = compat_sock_common_getsockopt,
1165 static struct inet_protosw mptcp_protosw = {
1166 .type = SOCK_STREAM,
1167 .protocol = IPPROTO_MPTCP,
1168 .prot = &mptcp_prot,
1169 .ops = &mptcp_stream_ops,
1170 .flags = INET_PROTOSW_ICSK,
1173 void mptcp_proto_init(void)
1175 mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;
1177 mptcp_subflow_init();
1179 if (proto_register(&mptcp_prot, 1) != 0)
1180 panic("Failed to register MPTCP proto.\n");
1182 inet_register_protosw(&mptcp_protosw);
1185 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1186 static const struct proto_ops mptcp_v6_stream_ops = {
1188 .owner = THIS_MODULE,
1189 .release = inet6_release,
1191 .connect = mptcp_stream_connect,
1192 .socketpair = sock_no_socketpair,
1193 .accept = mptcp_stream_accept,
1194 .getname = mptcp_v6_getname,
1196 .ioctl = inet6_ioctl,
1197 .gettstamp = sock_gettstamp,
1198 .listen = mptcp_listen,
1199 .shutdown = mptcp_shutdown,
1200 .setsockopt = sock_common_setsockopt,
1201 .getsockopt = sock_common_getsockopt,
1202 .sendmsg = inet6_sendmsg,
1203 .recvmsg = inet6_recvmsg,
1204 .mmap = sock_no_mmap,
1205 .sendpage = inet_sendpage,
1206 #ifdef CONFIG_COMPAT
1207 .compat_setsockopt = compat_sock_common_setsockopt,
1208 .compat_getsockopt = compat_sock_common_getsockopt,
1212 static struct proto mptcp_v6_prot;
1214 static void mptcp_v6_destroy(struct sock *sk)
1217 inet6_destroy_sock(sk);
1220 static struct inet_protosw mptcp_v6_protosw = {
1221 .type = SOCK_STREAM,
1222 .protocol = IPPROTO_MPTCP,
1223 .prot = &mptcp_v6_prot,
1224 .ops = &mptcp_v6_stream_ops,
1225 .flags = INET_PROTOSW_ICSK,
1228 int mptcp_proto_v6_init(void)
1232 mptcp_v6_prot = mptcp_prot;
1233 strcpy(mptcp_v6_prot.name, "MPTCPv6");
1234 mptcp_v6_prot.slab = NULL;
1235 mptcp_v6_prot.destroy = mptcp_v6_destroy;
1236 mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock);
1238 err = proto_register(&mptcp_v6_prot, 1);
1242 err = inet6_register_protosw(&mptcp_v6_protosw);
1244 proto_unregister(&mptcp_v6_prot);