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 #include <net/tcp_states.h>
20 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
21 #include <net/transp_v6.h>
23 #include <net/mptcp.h>
25 #include <asm/ioctls.h>
29 #define CREATE_TRACE_POINTS
30 #include <trace/events/mptcp.h>
32 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
34 struct mptcp_sock msk;
46 #define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0]))
49 MPTCP_CMSG_TS = BIT(0),
50 MPTCP_CMSG_INQ = BIT(1),
53 static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp;
55 static void __mptcp_destroy_sock(struct sock *sk);
56 static void __mptcp_check_send_data_fin(struct sock *sk);
58 DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
59 static struct net_device mptcp_napi_dev;
61 /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not
62 * completed yet or has failed, return the subflow socket.
63 * Otherwise return NULL.
65 struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk)
67 if (!msk->subflow || READ_ONCE(msk->can_ack))
73 /* Returns end sequence number of the receiver's advertised window */
74 static u64 mptcp_wnd_end(const struct mptcp_sock *msk)
76 return READ_ONCE(msk->wnd_end);
79 static bool mptcp_is_tcpsk(struct sock *sk)
81 struct socket *sock = sk->sk_socket;
83 if (unlikely(sk->sk_prot == &tcp_prot)) {
84 /* we are being invoked after mptcp_accept() has
85 * accepted a non-mp-capable flow: sk is a tcp_sk,
88 * Hand the socket over to tcp so all further socket ops
91 sock->ops = &inet_stream_ops;
93 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
94 } else if (unlikely(sk->sk_prot == &tcpv6_prot)) {
95 sock->ops = &inet6_stream_ops;
103 static int __mptcp_socket_create(struct mptcp_sock *msk)
105 struct mptcp_subflow_context *subflow;
106 struct sock *sk = (struct sock *)msk;
107 struct socket *ssock;
110 err = mptcp_subflow_create_socket(sk, &ssock);
114 msk->first = ssock->sk;
115 msk->subflow = ssock;
116 subflow = mptcp_subflow_ctx(ssock->sk);
117 list_add(&subflow->node, &msk->conn_list);
118 sock_hold(ssock->sk);
119 subflow->request_mptcp = 1;
121 /* This is the first subflow, always with id 0 */
122 subflow->local_id_valid = 1;
123 mptcp_sock_graft(msk->first, sk->sk_socket);
128 static void mptcp_drop(struct sock *sk, struct sk_buff *skb)
130 sk_drops_add(sk, skb);
134 static void mptcp_rmem_charge(struct sock *sk, int size)
136 mptcp_sk(sk)->rmem_fwd_alloc -= size;
139 static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
140 struct sk_buff *from)
145 if (MPTCP_SKB_CB(from)->offset ||
146 !skb_try_coalesce(to, from, &fragstolen, &delta))
149 pr_debug("colesced seq %llx into %llx new len %d new end seq %llx",
150 MPTCP_SKB_CB(from)->map_seq, MPTCP_SKB_CB(to)->map_seq,
151 to->len, MPTCP_SKB_CB(from)->end_seq);
152 MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq;
153 kfree_skb_partial(from, fragstolen);
154 atomic_add(delta, &sk->sk_rmem_alloc);
155 mptcp_rmem_charge(sk, delta);
159 static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to,
160 struct sk_buff *from)
162 if (MPTCP_SKB_CB(from)->map_seq != MPTCP_SKB_CB(to)->end_seq)
165 return mptcp_try_coalesce((struct sock *)msk, to, from);
168 static void __mptcp_rmem_reclaim(struct sock *sk, int amount)
170 amount >>= SK_MEM_QUANTUM_SHIFT;
171 mptcp_sk(sk)->rmem_fwd_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
172 __sk_mem_reduce_allocated(sk, amount);
175 static void mptcp_rmem_uncharge(struct sock *sk, int size)
177 struct mptcp_sock *msk = mptcp_sk(sk);
180 msk->rmem_fwd_alloc += size;
181 reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
183 /* see sk_mem_uncharge() for the rationale behind the following schema */
184 if (unlikely(reclaimable >= SK_RECLAIM_THRESHOLD))
185 __mptcp_rmem_reclaim(sk, SK_RECLAIM_CHUNK);
188 static void mptcp_rfree(struct sk_buff *skb)
190 unsigned int len = skb->truesize;
191 struct sock *sk = skb->sk;
193 atomic_sub(len, &sk->sk_rmem_alloc);
194 mptcp_rmem_uncharge(sk, len);
197 static void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk)
201 skb->destructor = mptcp_rfree;
202 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
203 mptcp_rmem_charge(sk, skb->truesize);
206 /* "inspired" by tcp_data_queue_ofo(), main differences:
208 * - don't cope with sacks
210 static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
212 struct sock *sk = (struct sock *)msk;
213 struct rb_node **p, *parent;
214 u64 seq, end_seq, max_seq;
215 struct sk_buff *skb1;
217 seq = MPTCP_SKB_CB(skb)->map_seq;
218 end_seq = MPTCP_SKB_CB(skb)->end_seq;
219 max_seq = atomic64_read(&msk->rcv_wnd_sent);
221 pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq,
222 RB_EMPTY_ROOT(&msk->out_of_order_queue));
223 if (after64(end_seq, max_seq)) {
226 pr_debug("oow by %lld, rcv_wnd_sent %llu\n",
227 (unsigned long long)end_seq - (unsigned long)max_seq,
228 (unsigned long long)atomic64_read(&msk->rcv_wnd_sent));
229 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW);
233 p = &msk->out_of_order_queue.rb_node;
234 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE);
235 if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) {
236 rb_link_node(&skb->rbnode, NULL, p);
237 rb_insert_color(&skb->rbnode, &msk->out_of_order_queue);
238 msk->ooo_last_skb = skb;
242 /* with 2 subflows, adding at end of ooo queue is quite likely
243 * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
245 if (mptcp_ooo_try_coalesce(msk, msk->ooo_last_skb, skb)) {
246 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
247 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
251 /* Can avoid an rbtree lookup if we are adding skb after ooo_last_skb */
252 if (!before64(seq, MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq)) {
253 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
254 parent = &msk->ooo_last_skb->rbnode;
255 p = &parent->rb_right;
259 /* Find place to insert this segment. Handle overlaps on the way. */
263 skb1 = rb_to_skb(parent);
264 if (before64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
265 p = &parent->rb_left;
268 if (before64(seq, MPTCP_SKB_CB(skb1)->end_seq)) {
269 if (!after64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) {
270 /* All the bits are present. Drop. */
272 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
275 if (after64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
279 * continue traversing
282 /* skb's seq == skb1's seq and skb covers skb1.
283 * Replace skb1 with skb.
285 rb_replace_node(&skb1->rbnode, &skb->rbnode,
286 &msk->out_of_order_queue);
287 mptcp_drop(sk, skb1);
288 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
291 } else if (mptcp_ooo_try_coalesce(msk, skb1, skb)) {
292 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
295 p = &parent->rb_right;
299 /* Insert segment into RB tree. */
300 rb_link_node(&skb->rbnode, parent, p);
301 rb_insert_color(&skb->rbnode, &msk->out_of_order_queue);
304 /* Remove other segments covered by skb. */
305 while ((skb1 = skb_rb_next(skb)) != NULL) {
306 if (before64(end_seq, MPTCP_SKB_CB(skb1)->end_seq))
308 rb_erase(&skb1->rbnode, &msk->out_of_order_queue);
309 mptcp_drop(sk, skb1);
310 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
312 /* If there is no skb after us, we are the last_skb ! */
314 msk->ooo_last_skb = skb;
318 mptcp_set_owner_r(skb, sk);
321 static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
323 struct mptcp_sock *msk = mptcp_sk(sk);
326 if (size < msk->rmem_fwd_alloc)
329 amt = sk_mem_pages(size);
330 amount = amt << SK_MEM_QUANTUM_SHIFT;
331 msk->rmem_fwd_alloc += amount;
332 if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) {
333 if (ssk->sk_forward_alloc < amount) {
334 msk->rmem_fwd_alloc -= amount;
338 ssk->sk_forward_alloc -= amount;
343 static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
344 struct sk_buff *skb, unsigned int offset,
347 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
348 struct sock *sk = (struct sock *)msk;
349 struct sk_buff *tail;
352 __skb_unlink(skb, &ssk->sk_receive_queue);
357 /* try to fetch required memory from subflow */
358 if (!mptcp_rmem_schedule(sk, ssk, skb->truesize))
361 has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp;
363 /* the skb map_seq accounts for the skb offset:
364 * mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq
367 MPTCP_SKB_CB(skb)->map_seq = mptcp_subflow_get_mapped_dsn(subflow);
368 MPTCP_SKB_CB(skb)->end_seq = MPTCP_SKB_CB(skb)->map_seq + copy_len;
369 MPTCP_SKB_CB(skb)->offset = offset;
370 MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp;
372 if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) {
374 WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len);
375 tail = skb_peek_tail(&sk->sk_receive_queue);
376 if (tail && mptcp_try_coalesce(sk, tail, skb))
379 mptcp_set_owner_r(skb, sk);
380 __skb_queue_tail(&sk->sk_receive_queue, skb);
382 } else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) {
383 mptcp_data_queue_ofo(msk, skb);
387 /* old data, keep it simple and drop the whole pkt, sender
388 * will retransmit as needed, if needed.
390 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
396 static void mptcp_stop_timer(struct sock *sk)
398 struct inet_connection_sock *icsk = inet_csk(sk);
400 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
401 mptcp_sk(sk)->timer_ival = 0;
404 static void mptcp_close_wake_up(struct sock *sk)
406 if (sock_flag(sk, SOCK_DEAD))
409 sk->sk_state_change(sk);
410 if (sk->sk_shutdown == SHUTDOWN_MASK ||
411 sk->sk_state == TCP_CLOSE)
412 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
414 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
417 static bool mptcp_pending_data_fin_ack(struct sock *sk)
419 struct mptcp_sock *msk = mptcp_sk(sk);
421 return !__mptcp_check_fallback(msk) &&
422 ((1 << sk->sk_state) &
423 (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK)) &&
424 msk->write_seq == READ_ONCE(msk->snd_una);
427 static void mptcp_check_data_fin_ack(struct sock *sk)
429 struct mptcp_sock *msk = mptcp_sk(sk);
431 /* Look for an acknowledged DATA_FIN */
432 if (mptcp_pending_data_fin_ack(sk)) {
433 WRITE_ONCE(msk->snd_data_fin_enable, 0);
435 switch (sk->sk_state) {
437 inet_sk_state_store(sk, TCP_FIN_WAIT2);
441 inet_sk_state_store(sk, TCP_CLOSE);
445 mptcp_close_wake_up(sk);
449 static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq)
451 struct mptcp_sock *msk = mptcp_sk(sk);
453 if (READ_ONCE(msk->rcv_data_fin) &&
454 ((1 << sk->sk_state) &
455 (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2))) {
456 u64 rcv_data_fin_seq = READ_ONCE(msk->rcv_data_fin_seq);
458 if (msk->ack_seq == rcv_data_fin_seq) {
460 *seq = rcv_data_fin_seq;
469 static void mptcp_set_datafin_timeout(const struct sock *sk)
471 struct inet_connection_sock *icsk = inet_csk(sk);
474 retransmits = min_t(u32, icsk->icsk_retransmits,
475 ilog2(TCP_RTO_MAX / TCP_RTO_MIN));
477 mptcp_sk(sk)->timer_ival = TCP_RTO_MIN << retransmits;
480 static void __mptcp_set_timeout(struct sock *sk, long tout)
482 mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN;
485 static long mptcp_timeout_from_subflow(const struct mptcp_subflow_context *subflow)
487 const struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
489 return inet_csk(ssk)->icsk_pending && !subflow->stale_count ?
490 inet_csk(ssk)->icsk_timeout - jiffies : 0;
493 static void mptcp_set_timeout(struct sock *sk)
495 struct mptcp_subflow_context *subflow;
498 mptcp_for_each_subflow(mptcp_sk(sk), subflow)
499 tout = max(tout, mptcp_timeout_from_subflow(subflow));
500 __mptcp_set_timeout(sk, tout);
503 static inline bool tcp_can_send_ack(const struct sock *ssk)
505 return !((1 << inet_sk_state_load(ssk)) &
506 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN));
509 void __mptcp_subflow_send_ack(struct sock *ssk)
511 if (tcp_can_send_ack(ssk))
515 void mptcp_subflow_send_ack(struct sock *ssk)
519 slow = lock_sock_fast(ssk);
520 __mptcp_subflow_send_ack(ssk);
521 unlock_sock_fast(ssk, slow);
524 static void mptcp_send_ack(struct mptcp_sock *msk)
526 struct mptcp_subflow_context *subflow;
528 mptcp_for_each_subflow(msk, subflow)
529 mptcp_subflow_send_ack(mptcp_subflow_tcp_sock(subflow));
532 static void mptcp_subflow_cleanup_rbuf(struct sock *ssk)
536 slow = lock_sock_fast(ssk);
537 if (tcp_can_send_ack(ssk))
538 tcp_cleanup_rbuf(ssk, 1);
539 unlock_sock_fast(ssk, slow);
542 static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_empty)
544 const struct inet_connection_sock *icsk = inet_csk(ssk);
545 u8 ack_pending = READ_ONCE(icsk->icsk_ack.pending);
546 const struct tcp_sock *tp = tcp_sk(ssk);
548 return (ack_pending & ICSK_ACK_SCHED) &&
549 ((READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->rcv_wup) >
550 READ_ONCE(icsk->icsk_ack.rcv_mss)) ||
551 (rx_empty && ack_pending &
552 (ICSK_ACK_PUSHED2 | ICSK_ACK_PUSHED)));
555 static void mptcp_cleanup_rbuf(struct mptcp_sock *msk)
557 int old_space = READ_ONCE(msk->old_wspace);
558 struct mptcp_subflow_context *subflow;
559 struct sock *sk = (struct sock *)msk;
560 int space = __mptcp_space(sk);
561 bool cleanup, rx_empty;
563 cleanup = (space > 0) && (space >= (old_space << 1));
564 rx_empty = !__mptcp_rmem(sk);
566 mptcp_for_each_subflow(msk, subflow) {
567 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
569 if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty))
570 mptcp_subflow_cleanup_rbuf(ssk);
574 static bool mptcp_check_data_fin(struct sock *sk)
576 struct mptcp_sock *msk = mptcp_sk(sk);
577 u64 rcv_data_fin_seq;
580 if (__mptcp_check_fallback(msk))
583 /* Need to ack a DATA_FIN received from a peer while this side
584 * of the connection is in ESTABLISHED, FIN_WAIT1, or FIN_WAIT2.
585 * msk->rcv_data_fin was set when parsing the incoming options
586 * at the subflow level and the msk lock was not held, so this
587 * is the first opportunity to act on the DATA_FIN and change
590 * If we are caught up to the sequence number of the incoming
591 * DATA_FIN, send the DATA_ACK now and do state transition. If
592 * not caught up, do nothing and let the recv code send DATA_ACK
596 if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) {
597 WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1);
598 WRITE_ONCE(msk->rcv_data_fin, 0);
600 sk->sk_shutdown |= RCV_SHUTDOWN;
601 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
603 switch (sk->sk_state) {
604 case TCP_ESTABLISHED:
605 inet_sk_state_store(sk, TCP_CLOSE_WAIT);
608 inet_sk_state_store(sk, TCP_CLOSING);
611 inet_sk_state_store(sk, TCP_CLOSE);
614 /* Other states not expected */
621 mptcp_close_wake_up(sk);
626 static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
630 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
631 struct sock *sk = (struct sock *)msk;
632 unsigned int moved = 0;
633 bool more_data_avail;
638 sk_rbuf = READ_ONCE(sk->sk_rcvbuf);
640 if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
641 int ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf);
643 if (unlikely(ssk_rbuf > sk_rbuf)) {
644 WRITE_ONCE(sk->sk_rcvbuf, ssk_rbuf);
649 pr_debug("msk=%p ssk=%p", msk, ssk);
652 u32 map_remaining, offset;
653 u32 seq = tp->copied_seq;
657 /* try to move as much data as available */
658 map_remaining = subflow->map_data_len -
659 mptcp_subflow_get_map_offset(subflow);
661 skb = skb_peek(&ssk->sk_receive_queue);
663 /* if no data is found, a racing workqueue/recvmsg
664 * already processed the new data, stop here or we
665 * can enter an infinite loop
672 if (__mptcp_check_fallback(msk)) {
673 /* if we are running under the workqueue, TCP could have
674 * collapsed skbs between dummy map creation and now
675 * be sure to adjust the size
677 map_remaining = skb->len;
678 subflow->map_data_len = skb->len;
681 offset = seq - TCP_SKB_CB(skb)->seq;
682 fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
688 if (offset < skb->len) {
689 size_t len = skb->len - offset;
694 if (__mptcp_move_skb(msk, ssk, skb, offset, len))
698 if (WARN_ON_ONCE(map_remaining < len))
702 sk_eat_skb(ssk, skb);
706 WRITE_ONCE(tp->copied_seq, seq);
707 more_data_avail = mptcp_subflow_data_available(ssk);
709 if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) {
713 } while (more_data_avail);
719 static bool __mptcp_ofo_queue(struct mptcp_sock *msk)
721 struct sock *sk = (struct sock *)msk;
722 struct sk_buff *skb, *tail;
727 p = rb_first(&msk->out_of_order_queue);
728 pr_debug("msk=%p empty=%d", msk, RB_EMPTY_ROOT(&msk->out_of_order_queue));
731 if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq))
735 rb_erase(&skb->rbnode, &msk->out_of_order_queue);
737 if (unlikely(!after64(MPTCP_SKB_CB(skb)->end_seq,
740 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
744 end_seq = MPTCP_SKB_CB(skb)->end_seq;
745 tail = skb_peek_tail(&sk->sk_receive_queue);
746 if (!tail || !mptcp_ooo_try_coalesce(msk, tail, skb)) {
747 int delta = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq;
749 /* skip overlapping data, if any */
750 pr_debug("uncoalesced seq=%llx ack seq=%llx delta=%d",
751 MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq,
753 MPTCP_SKB_CB(skb)->offset += delta;
754 MPTCP_SKB_CB(skb)->map_seq += delta;
755 __skb_queue_tail(&sk->sk_receive_queue, skb);
757 msk->ack_seq = end_seq;
763 /* In most cases we will be able to lock the mptcp socket. If its already
764 * owned, we need to defer to the work queue to avoid ABBA deadlock.
766 static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
768 struct sock *sk = (struct sock *)msk;
769 unsigned int moved = 0;
771 __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
772 __mptcp_ofo_queue(msk);
773 if (unlikely(ssk->sk_err)) {
774 if (!sock_owned_by_user(sk))
775 __mptcp_error_report(sk);
777 __set_bit(MPTCP_ERROR_REPORT, &msk->cb_flags);
780 /* If the moves have caught up with the DATA_FIN sequence number
781 * it's time to ack the DATA_FIN and change socket state, but
782 * this is not a good place to change state. Let the workqueue
785 if (mptcp_pending_data_fin(sk, NULL))
786 mptcp_schedule_work(sk);
790 void mptcp_data_ready(struct sock *sk, struct sock *ssk)
792 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
793 struct mptcp_sock *msk = mptcp_sk(sk);
794 int sk_rbuf, ssk_rbuf;
796 /* The peer can send data while we are shutting down this
797 * subflow at msk destruction time, but we must avoid enqueuing
798 * more data to the msk receive queue
800 if (unlikely(subflow->disposable))
803 ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf);
804 sk_rbuf = READ_ONCE(sk->sk_rcvbuf);
805 if (unlikely(ssk_rbuf > sk_rbuf))
808 /* over limit? can't append more skbs to msk, Also, no need to wake-up*/
809 if (__mptcp_rmem(sk) > sk_rbuf) {
810 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
814 /* Wake-up the reader only for in-sequence data */
816 if (move_skbs_to_msk(msk, ssk))
817 sk->sk_data_ready(sk);
819 mptcp_data_unlock(sk);
822 static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
824 struct sock *sk = (struct sock *)msk;
826 if (sk->sk_state != TCP_ESTABLISHED)
829 /* attach to msk socket only after we are sure we will deal with it
832 if (sk->sk_socket && !ssk->sk_socket)
833 mptcp_sock_graft(ssk, sk->sk_socket);
835 mptcp_propagate_sndbuf((struct sock *)msk, ssk);
836 mptcp_sockopt_sync_locked(msk, ssk);
840 static void __mptcp_flush_join_list(struct sock *sk)
842 struct mptcp_subflow_context *tmp, *subflow;
843 struct mptcp_sock *msk = mptcp_sk(sk);
845 list_for_each_entry_safe(subflow, tmp, &msk->join_list, node) {
846 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
847 bool slow = lock_sock_fast(ssk);
849 list_move_tail(&subflow->node, &msk->conn_list);
850 if (!__mptcp_finish_join(msk, ssk))
851 mptcp_subflow_reset(ssk);
852 unlock_sock_fast(ssk, slow);
856 static bool mptcp_timer_pending(struct sock *sk)
858 return timer_pending(&inet_csk(sk)->icsk_retransmit_timer);
861 static void mptcp_reset_timer(struct sock *sk)
863 struct inet_connection_sock *icsk = inet_csk(sk);
866 /* prevent rescheduling on close */
867 if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE))
870 tout = mptcp_sk(sk)->timer_ival;
871 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout);
874 bool mptcp_schedule_work(struct sock *sk)
876 if (inet_sk_state_load(sk) != TCP_CLOSE &&
877 schedule_work(&mptcp_sk(sk)->work)) {
878 /* each subflow already holds a reference to the sk, and the
879 * workqueue is invoked by a subflow, so sk can't go away here.
887 void mptcp_subflow_eof(struct sock *sk)
889 if (!test_and_set_bit(MPTCP_WORK_EOF, &mptcp_sk(sk)->flags))
890 mptcp_schedule_work(sk);
893 static void mptcp_check_for_eof(struct mptcp_sock *msk)
895 struct mptcp_subflow_context *subflow;
896 struct sock *sk = (struct sock *)msk;
899 mptcp_for_each_subflow(msk, subflow)
900 receivers += !subflow->rx_eof;
904 if (!(sk->sk_shutdown & RCV_SHUTDOWN)) {
905 /* hopefully temporary hack: propagate shutdown status
906 * to msk, when all subflows agree on it
908 sk->sk_shutdown |= RCV_SHUTDOWN;
910 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
911 sk->sk_data_ready(sk);
914 switch (sk->sk_state) {
915 case TCP_ESTABLISHED:
916 inet_sk_state_store(sk, TCP_CLOSE_WAIT);
919 inet_sk_state_store(sk, TCP_CLOSING);
922 inet_sk_state_store(sk, TCP_CLOSE);
927 mptcp_close_wake_up(sk);
930 static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
932 struct mptcp_subflow_context *subflow;
933 struct sock *sk = (struct sock *)msk;
935 sock_owned_by_me(sk);
937 mptcp_for_each_subflow(msk, subflow) {
938 if (READ_ONCE(subflow->data_avail))
939 return mptcp_subflow_tcp_sock(subflow);
945 static bool mptcp_skb_can_collapse_to(u64 write_seq,
946 const struct sk_buff *skb,
947 const struct mptcp_ext *mpext)
949 if (!tcp_skb_can_collapse_to(skb))
952 /* can collapse only if MPTCP level sequence is in order and this
953 * mapping has not been xmitted yet
955 return mpext && mpext->data_seq + mpext->data_len == write_seq &&
959 /* we can append data to the given data frag if:
960 * - there is space available in the backing page_frag
961 * - the data frag tail matches the current page_frag free offset
962 * - the data frag end sequence number matches the current write seq
964 static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
965 const struct page_frag *pfrag,
966 const struct mptcp_data_frag *df)
968 return df && pfrag->page == df->page &&
969 pfrag->size - pfrag->offset > 0 &&
970 pfrag->offset == (df->offset + df->data_len) &&
971 df->data_seq + df->data_len == msk->write_seq;
974 static void __mptcp_mem_reclaim_partial(struct sock *sk)
976 int reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
978 lockdep_assert_held_once(&sk->sk_lock.slock);
980 if (reclaimable > SK_MEM_QUANTUM)
981 __mptcp_rmem_reclaim(sk, reclaimable - 1);
983 sk_mem_reclaim_partial(sk);
986 static void mptcp_mem_reclaim_partial(struct sock *sk)
989 __mptcp_mem_reclaim_partial(sk);
990 mptcp_data_unlock(sk);
993 static void dfrag_uncharge(struct sock *sk, int len)
995 sk_mem_uncharge(sk, len);
996 sk_wmem_queued_add(sk, -len);
999 static void dfrag_clear(struct sock *sk, struct mptcp_data_frag *dfrag)
1001 int len = dfrag->data_len + dfrag->overhead;
1003 list_del(&dfrag->list);
1004 dfrag_uncharge(sk, len);
1005 put_page(dfrag->page);
1008 static void __mptcp_clean_una(struct sock *sk)
1010 struct mptcp_sock *msk = mptcp_sk(sk);
1011 struct mptcp_data_frag *dtmp, *dfrag;
1012 bool cleaned = false;
1015 /* on fallback we just need to ignore snd_una, as this is really
1018 if (__mptcp_check_fallback(msk))
1019 msk->snd_una = READ_ONCE(msk->snd_nxt);
1021 snd_una = msk->snd_una;
1022 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) {
1023 if (after64(dfrag->data_seq + dfrag->data_len, snd_una))
1026 if (unlikely(dfrag == msk->first_pending)) {
1027 /* in recovery mode can see ack after the current snd head */
1028 if (WARN_ON_ONCE(!msk->recovery))
1031 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1034 dfrag_clear(sk, dfrag);
1038 dfrag = mptcp_rtx_head(sk);
1039 if (dfrag && after64(snd_una, dfrag->data_seq)) {
1040 u64 delta = snd_una - dfrag->data_seq;
1042 /* prevent wrap around in recovery mode */
1043 if (unlikely(delta > dfrag->already_sent)) {
1044 if (WARN_ON_ONCE(!msk->recovery))
1046 if (WARN_ON_ONCE(delta > dfrag->data_len))
1048 dfrag->already_sent += delta - dfrag->already_sent;
1051 dfrag->data_seq += delta;
1052 dfrag->offset += delta;
1053 dfrag->data_len -= delta;
1054 dfrag->already_sent -= delta;
1056 dfrag_uncharge(sk, delta);
1060 /* all retransmitted data acked, recovery completed */
1061 if (unlikely(msk->recovery) && after64(msk->snd_una, msk->recovery_snd_nxt))
1062 msk->recovery = false;
1065 if (cleaned && tcp_under_memory_pressure(sk))
1066 __mptcp_mem_reclaim_partial(sk);
1068 if (snd_una == READ_ONCE(msk->snd_nxt) &&
1069 snd_una == READ_ONCE(msk->write_seq)) {
1070 if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk))
1071 mptcp_stop_timer(sk);
1073 mptcp_reset_timer(sk);
1077 static void __mptcp_clean_una_wakeup(struct sock *sk)
1079 lockdep_assert_held_once(&sk->sk_lock.slock);
1081 __mptcp_clean_una(sk);
1082 mptcp_write_space(sk);
1085 static void mptcp_clean_una_wakeup(struct sock *sk)
1087 mptcp_data_lock(sk);
1088 __mptcp_clean_una_wakeup(sk);
1089 mptcp_data_unlock(sk);
1092 static void mptcp_enter_memory_pressure(struct sock *sk)
1094 struct mptcp_subflow_context *subflow;
1095 struct mptcp_sock *msk = mptcp_sk(sk);
1098 sk_stream_moderate_sndbuf(sk);
1099 mptcp_for_each_subflow(msk, subflow) {
1100 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
1103 tcp_enter_memory_pressure(ssk);
1104 sk_stream_moderate_sndbuf(ssk);
1109 /* ensure we get enough memory for the frag hdr, beyond some minimal amount of
1112 static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1114 if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
1115 pfrag, sk->sk_allocation)))
1118 mptcp_enter_memory_pressure(sk);
1122 static struct mptcp_data_frag *
1123 mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
1126 int offset = ALIGN(orig_offset, sizeof(long));
1127 struct mptcp_data_frag *dfrag;
1129 dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset);
1130 dfrag->data_len = 0;
1131 dfrag->data_seq = msk->write_seq;
1132 dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
1133 dfrag->offset = offset + sizeof(struct mptcp_data_frag);
1134 dfrag->already_sent = 0;
1135 dfrag->page = pfrag->page;
1140 struct mptcp_sendmsg_info {
1146 bool data_lock_held;
1149 static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *ssk,
1150 u64 data_seq, int avail_size)
1152 u64 window_end = mptcp_wnd_end(msk);
1155 if (__mptcp_check_fallback(msk))
1158 mptcp_snd_wnd = window_end - data_seq;
1159 avail_size = min_t(unsigned int, mptcp_snd_wnd, avail_size);
1161 if (unlikely(tcp_sk(ssk)->snd_wnd < mptcp_snd_wnd)) {
1162 tcp_sk(ssk)->snd_wnd = min_t(u64, U32_MAX, mptcp_snd_wnd);
1163 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_SNDWNDSHARED);
1169 static bool __mptcp_add_ext(struct sk_buff *skb, gfp_t gfp)
1171 struct skb_ext *mpext = __skb_ext_alloc(gfp);
1175 __skb_ext_set(skb, SKB_EXT_MPTCP, mpext);
1179 static struct sk_buff *__mptcp_do_alloc_tx_skb(struct sock *sk, gfp_t gfp)
1181 struct sk_buff *skb;
1183 skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp);
1185 if (likely(__mptcp_add_ext(skb, gfp))) {
1186 skb_reserve(skb, MAX_TCP_HEADER);
1187 skb->ip_summed = CHECKSUM_PARTIAL;
1188 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
1193 mptcp_enter_memory_pressure(sk);
1198 static struct sk_buff *__mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp)
1200 struct sk_buff *skb;
1202 skb = __mptcp_do_alloc_tx_skb(sk, gfp);
1206 if (likely(sk_wmem_schedule(ssk, skb->truesize))) {
1207 tcp_skb_entail(ssk, skb);
1210 tcp_skb_tsorted_anchor_cleanup(skb);
1215 static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, bool data_lock_held)
1217 gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation;
1219 if (unlikely(tcp_under_memory_pressure(sk))) {
1221 __mptcp_mem_reclaim_partial(sk);
1223 mptcp_mem_reclaim_partial(sk);
1225 return __mptcp_alloc_tx_skb(sk, ssk, gfp);
1228 /* note: this always recompute the csum on the whole skb, even
1229 * if we just appended a single frag. More status info needed
1231 static void mptcp_update_data_checksum(struct sk_buff *skb, int added)
1233 struct mptcp_ext *mpext = mptcp_get_ext(skb);
1234 __wsum csum = ~csum_unfold(mpext->csum);
1235 int offset = skb->len - added;
1237 mpext->csum = csum_fold(csum_block_add(csum, skb_checksum(skb, offset, added, 0), offset));
1240 static void mptcp_update_infinite_map(struct mptcp_sock *msk,
1242 struct mptcp_ext *mpext)
1247 mpext->infinite_map = 1;
1248 mpext->data_len = 0;
1250 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX);
1251 mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
1253 mptcp_do_fallback(ssk);
1256 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
1257 struct mptcp_data_frag *dfrag,
1258 struct mptcp_sendmsg_info *info)
1260 u64 data_seq = dfrag->data_seq + info->sent;
1261 int offset = dfrag->offset + info->sent;
1262 struct mptcp_sock *msk = mptcp_sk(sk);
1263 bool zero_window_probe = false;
1264 struct mptcp_ext *mpext = NULL;
1265 bool can_coalesce = false;
1266 bool reuse_skb = true;
1267 struct sk_buff *skb;
1271 pr_debug("msk=%p ssk=%p sending dfrag at seq=%llu len=%u already sent=%u",
1272 msk, ssk, dfrag->data_seq, dfrag->data_len, info->sent);
1274 if (WARN_ON_ONCE(info->sent > info->limit ||
1275 info->limit > dfrag->data_len))
1278 /* compute send limit */
1279 info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags);
1280 copy = info->size_goal;
1282 skb = tcp_write_queue_tail(ssk);
1283 if (skb && copy > skb->len) {
1284 /* Limit the write to the size available in the
1285 * current skb, if any, so that we create at most a new skb.
1286 * Explicitly tells TCP internals to avoid collapsing on later
1287 * queue management operation, to avoid breaking the ext <->
1288 * SSN association set here
1290 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
1291 if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) {
1292 TCP_SKB_CB(skb)->eor = 1;
1296 i = skb_shinfo(skb)->nr_frags;
1297 can_coalesce = skb_can_coalesce(skb, i, dfrag->page, offset);
1298 if (!can_coalesce && i >= sysctl_max_skb_frags) {
1299 tcp_mark_push(tcp_sk(ssk), skb);
1306 skb = mptcp_alloc_tx_skb(sk, ssk, info->data_lock_held);
1310 i = skb_shinfo(skb)->nr_frags;
1312 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
1315 /* Zero window and all data acked? Probe. */
1316 copy = mptcp_check_allowed_size(msk, ssk, data_seq, copy);
1318 u64 snd_una = READ_ONCE(msk->snd_una);
1320 if (snd_una != msk->snd_nxt) {
1321 tcp_remove_empty_skb(ssk);
1325 zero_window_probe = true;
1326 data_seq = snd_una - 1;
1329 /* all mptcp-level data is acked, no skbs should be present into the
1332 WARN_ON_ONCE(reuse_skb);
1335 copy = min_t(size_t, copy, info->limit - info->sent);
1336 if (!sk_wmem_schedule(ssk, copy)) {
1337 tcp_remove_empty_skb(ssk);
1342 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1344 get_page(dfrag->page);
1345 skb_fill_page_desc(skb, i, dfrag->page, offset, copy);
1349 skb->data_len += copy;
1350 skb->truesize += copy;
1351 sk_wmem_queued_add(ssk, copy);
1352 sk_mem_charge(ssk, copy);
1353 WRITE_ONCE(tcp_sk(ssk)->write_seq, tcp_sk(ssk)->write_seq + copy);
1354 TCP_SKB_CB(skb)->end_seq += copy;
1355 tcp_skb_pcount_set(skb, 0);
1357 /* on skb reuse we just need to update the DSS len */
1359 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1360 mpext->data_len += copy;
1361 WARN_ON_ONCE(zero_window_probe);
1365 memset(mpext, 0, sizeof(*mpext));
1366 mpext->data_seq = data_seq;
1367 mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq;
1368 mpext->data_len = copy;
1372 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d",
1373 mpext->data_seq, mpext->subflow_seq, mpext->data_len,
1376 if (zero_window_probe) {
1377 mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
1379 if (READ_ONCE(msk->csum_enabled))
1380 mptcp_update_data_checksum(skb, copy);
1381 tcp_push_pending_frames(ssk);
1385 if (READ_ONCE(msk->csum_enabled))
1386 mptcp_update_data_checksum(skb, copy);
1387 if (mptcp_subflow_ctx(ssk)->send_infinite_map)
1388 mptcp_update_infinite_map(msk, ssk, mpext);
1389 trace_mptcp_sendmsg_frag(mpext);
1390 mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
1394 #define MPTCP_SEND_BURST_SIZE ((1 << 16) - \
1395 sizeof(struct tcphdr) - \
1396 MAX_TCP_OPTION_SPACE - \
1397 sizeof(struct ipv6hdr) - \
1398 sizeof(struct frag_hdr))
1400 struct subflow_send_info {
1405 void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow)
1407 if (!subflow->stale)
1411 MPTCP_INC_STATS(sock_net(mptcp_subflow_tcp_sock(subflow)), MPTCP_MIB_SUBFLOWRECOVER);
1414 bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
1416 if (unlikely(subflow->stale)) {
1417 u32 rcv_tstamp = READ_ONCE(tcp_sk(mptcp_subflow_tcp_sock(subflow))->rcv_tstamp);
1419 if (subflow->stale_rcv_tstamp == rcv_tstamp)
1422 mptcp_subflow_set_active(subflow);
1424 return __mptcp_subflow_active(subflow);
1427 #define SSK_MODE_ACTIVE 0
1428 #define SSK_MODE_BACKUP 1
1429 #define SSK_MODE_MAX 2
1431 /* implement the mptcp packet scheduler;
1432 * returns the subflow that will transmit the next DSS
1433 * additionally updates the rtx timeout
1435 static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
1437 struct subflow_send_info send_info[SSK_MODE_MAX];
1438 struct mptcp_subflow_context *subflow;
1439 struct sock *sk = (struct sock *)msk;
1440 u32 pace, burst, wmem;
1441 int i, nr_active = 0;
1446 sock_owned_by_me(sk);
1448 if (__mptcp_check_fallback(msk)) {
1451 return sk_stream_memory_free(msk->first) ? msk->first : NULL;
1454 /* re-use last subflow, if the burst allow that */
1455 if (msk->last_snd && msk->snd_burst > 0 &&
1456 sk_stream_memory_free(msk->last_snd) &&
1457 mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) {
1458 mptcp_set_timeout(sk);
1459 return msk->last_snd;
1462 /* pick the subflow with the lower wmem/wspace ratio */
1463 for (i = 0; i < SSK_MODE_MAX; ++i) {
1464 send_info[i].ssk = NULL;
1465 send_info[i].linger_time = -1;
1468 mptcp_for_each_subflow(msk, subflow) {
1469 trace_mptcp_subflow_get_send(subflow);
1470 ssk = mptcp_subflow_tcp_sock(subflow);
1471 if (!mptcp_subflow_active(subflow))
1474 tout = max(tout, mptcp_timeout_from_subflow(subflow));
1475 nr_active += !subflow->backup;
1476 pace = subflow->avg_pacing_rate;
1477 if (unlikely(!pace)) {
1478 /* init pacing rate from socket */
1479 subflow->avg_pacing_rate = READ_ONCE(ssk->sk_pacing_rate);
1480 pace = subflow->avg_pacing_rate;
1485 linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace);
1486 if (linger_time < send_info[subflow->backup].linger_time) {
1487 send_info[subflow->backup].ssk = ssk;
1488 send_info[subflow->backup].linger_time = linger_time;
1491 __mptcp_set_timeout(sk, tout);
1493 /* pick the best backup if no other subflow is active */
1495 send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk;
1497 /* According to the blest algorithm, to avoid HoL blocking for the
1498 * faster flow, we need to:
1499 * - estimate the faster flow linger time
1500 * - use the above to estimate the amount of byte transferred
1501 * by the faster flow
1502 * - check that the amount of queued data is greter than the above,
1503 * otherwise do not use the picked, slower, subflow
1504 * We select the subflow with the shorter estimated time to flush
1505 * the queued mem, which basically ensure the above. We just need
1506 * to check that subflow has a non empty cwin.
1508 ssk = send_info[SSK_MODE_ACTIVE].ssk;
1509 if (!ssk || !sk_stream_memory_free(ssk))
1512 burst = min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
1513 wmem = READ_ONCE(ssk->sk_wmem_queued);
1515 msk->last_snd = NULL;
1519 subflow = mptcp_subflow_ctx(ssk);
1520 subflow->avg_pacing_rate = div_u64((u64)subflow->avg_pacing_rate * wmem +
1521 READ_ONCE(ssk->sk_pacing_rate) * burst,
1523 msk->last_snd = ssk;
1524 msk->snd_burst = burst;
1528 static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info)
1530 tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal);
1534 static void mptcp_update_post_push(struct mptcp_sock *msk,
1535 struct mptcp_data_frag *dfrag,
1538 u64 snd_nxt_new = dfrag->data_seq;
1540 dfrag->already_sent += sent;
1542 msk->snd_burst -= sent;
1544 snd_nxt_new += dfrag->already_sent;
1546 /* snd_nxt_new can be smaller than snd_nxt in case mptcp
1547 * is recovering after a failover. In that event, this re-sends
1550 * Thus compute snd_nxt_new candidate based on
1551 * the dfrag->data_seq that was sent and the data
1552 * that has been handed to the subflow for transmission
1553 * and skip update in case it was old dfrag.
1555 if (likely(after64(snd_nxt_new, msk->snd_nxt)))
1556 msk->snd_nxt = snd_nxt_new;
1559 void mptcp_check_and_set_pending(struct sock *sk)
1561 if (mptcp_send_head(sk))
1562 mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING);
1565 void __mptcp_push_pending(struct sock *sk, unsigned int flags)
1567 struct sock *prev_ssk = NULL, *ssk = NULL;
1568 struct mptcp_sock *msk = mptcp_sk(sk);
1569 struct mptcp_sendmsg_info info = {
1572 struct mptcp_data_frag *dfrag;
1573 int len, copied = 0;
1575 while ((dfrag = mptcp_send_head(sk))) {
1576 info.sent = dfrag->already_sent;
1577 info.limit = dfrag->data_len;
1578 len = dfrag->data_len - dfrag->already_sent;
1583 ssk = mptcp_subflow_get_send(msk);
1585 /* First check. If the ssk has changed since
1586 * the last round, release prev_ssk
1588 if (ssk != prev_ssk && prev_ssk)
1589 mptcp_push_release(prev_ssk, &info);
1593 /* Need to lock the new subflow only if different
1594 * from the previous one, otherwise we are still
1595 * helding the relevant lock
1597 if (ssk != prev_ssk)
1600 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
1602 mptcp_push_release(ssk, &info);
1610 mptcp_update_post_push(msk, dfrag, ret);
1612 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1615 /* at this point we held the socket lock for the last subflow we used */
1617 mptcp_push_release(ssk, &info);
1620 /* ensure the rtx timer is running */
1621 if (!mptcp_timer_pending(sk))
1622 mptcp_reset_timer(sk);
1624 __mptcp_check_send_data_fin(sk);
1627 static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk)
1629 struct mptcp_sock *msk = mptcp_sk(sk);
1630 struct mptcp_sendmsg_info info = {
1631 .data_lock_held = true,
1633 struct mptcp_data_frag *dfrag;
1634 struct sock *xmit_ssk;
1635 int len, copied = 0;
1639 while ((dfrag = mptcp_send_head(sk))) {
1640 info.sent = dfrag->already_sent;
1641 info.limit = dfrag->data_len;
1642 len = dfrag->data_len - dfrag->already_sent;
1646 /* the caller already invoked the packet scheduler,
1647 * check for a different subflow usage only after
1648 * spooling the first chunk of data
1650 xmit_ssk = first ? ssk : mptcp_subflow_get_send(mptcp_sk(sk));
1653 if (xmit_ssk != ssk) {
1654 mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk),
1655 MPTCP_DELEGATE_SEND);
1659 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
1668 mptcp_update_post_push(msk, dfrag, ret);
1670 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1674 /* __mptcp_alloc_tx_skb could have released some wmem and we are
1675 * not going to flush it via release_sock()
1678 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
1680 if (!mptcp_timer_pending(sk))
1681 mptcp_reset_timer(sk);
1683 if (msk->snd_data_fin_enable &&
1684 msk->snd_nxt + 1 == msk->write_seq)
1685 mptcp_schedule_work(sk);
1689 static void mptcp_set_nospace(struct sock *sk)
1691 /* enable autotune */
1692 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1694 /* will be cleared on avail space */
1695 set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags);
1698 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1700 struct mptcp_sock *msk = mptcp_sk(sk);
1701 struct page_frag *pfrag;
1706 /* we don't support FASTOPEN yet */
1707 if (msg->msg_flags & MSG_FASTOPEN)
1710 /* silently ignore everything else */
1711 msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL;
1715 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1717 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
1718 ret = sk_stream_wait_connect(sk, &timeo);
1723 pfrag = sk_page_frag(sk);
1725 while (msg_data_left(msg)) {
1726 int total_ts, frag_truesize = 0;
1727 struct mptcp_data_frag *dfrag;
1728 bool dfrag_collapsed;
1729 size_t psize, offset;
1731 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) {
1736 /* reuse tail pfrag, if possible, or carve a new one from the
1739 dfrag = mptcp_pending_tail(sk);
1740 dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
1741 if (!dfrag_collapsed) {
1742 if (!sk_stream_memory_free(sk))
1743 goto wait_for_memory;
1745 if (!mptcp_page_frag_refill(sk, pfrag))
1746 goto wait_for_memory;
1748 dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
1749 frag_truesize = dfrag->overhead;
1752 /* we do not bound vs wspace, to allow a single packet.
1753 * memory accounting will prevent execessive memory usage
1756 offset = dfrag->offset + dfrag->data_len;
1757 psize = pfrag->size - offset;
1758 psize = min_t(size_t, psize, msg_data_left(msg));
1759 total_ts = psize + frag_truesize;
1761 if (!sk_wmem_schedule(sk, total_ts))
1762 goto wait_for_memory;
1764 if (copy_page_from_iter(dfrag->page, offset, psize,
1765 &msg->msg_iter) != psize) {
1770 /* data successfully copied into the write queue */
1771 sk->sk_forward_alloc -= total_ts;
1773 dfrag->data_len += psize;
1774 frag_truesize += psize;
1775 pfrag->offset += frag_truesize;
1776 WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
1778 /* charge data on mptcp pending queue to the msk socket
1779 * Note: we charge such data both to sk and ssk
1781 sk_wmem_queued_add(sk, frag_truesize);
1782 if (!dfrag_collapsed) {
1783 get_page(dfrag->page);
1784 list_add_tail(&dfrag->list, &msk->rtx_queue);
1785 if (!msk->first_pending)
1786 WRITE_ONCE(msk->first_pending, dfrag);
1788 pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk,
1789 dfrag->data_seq, dfrag->data_len, dfrag->already_sent,
1795 mptcp_set_nospace(sk);
1796 __mptcp_push_pending(sk, msg->msg_flags);
1797 ret = sk_stream_wait_memory(sk, &timeo);
1803 __mptcp_push_pending(sk, msg->msg_flags);
1807 return copied ? : ret;
1810 static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk,
1812 size_t len, int flags,
1813 struct scm_timestamping_internal *tss,
1816 struct sk_buff *skb, *tmp;
1819 skb_queue_walk_safe(&msk->receive_queue, skb, tmp) {
1820 u32 offset = MPTCP_SKB_CB(skb)->offset;
1821 u32 data_len = skb->len - offset;
1822 u32 count = min_t(size_t, len - copied, data_len);
1825 if (!(flags & MSG_TRUNC)) {
1826 err = skb_copy_datagram_msg(skb, offset, msg, count);
1827 if (unlikely(err < 0)) {
1834 if (MPTCP_SKB_CB(skb)->has_rxtstamp) {
1835 tcp_update_recv_tstamps(skb, tss);
1836 *cmsg_flags |= MPTCP_CMSG_TS;
1841 if (count < data_len) {
1842 if (!(flags & MSG_PEEK)) {
1843 MPTCP_SKB_CB(skb)->offset += count;
1844 MPTCP_SKB_CB(skb)->map_seq += count;
1849 if (!(flags & MSG_PEEK)) {
1850 /* we will bulk release the skb memory later */
1851 skb->destructor = NULL;
1852 WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize);
1853 __skb_unlink(skb, &msk->receive_queue);
1864 /* receive buffer autotuning. See tcp_rcv_space_adjust for more information.
1866 * Only difference: Use highest rtt estimate of the subflows in use.
1868 static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
1870 struct mptcp_subflow_context *subflow;
1871 struct sock *sk = (struct sock *)msk;
1872 u32 time, advmss = 1;
1875 sock_owned_by_me(sk);
1880 msk->rcvq_space.copied += copied;
1882 mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC);
1883 time = tcp_stamp_us_delta(mstamp, msk->rcvq_space.time);
1885 rtt_us = msk->rcvq_space.rtt_us;
1886 if (rtt_us && time < (rtt_us >> 3))
1890 mptcp_for_each_subflow(msk, subflow) {
1891 const struct tcp_sock *tp;
1895 tp = tcp_sk(mptcp_subflow_tcp_sock(subflow));
1897 sf_rtt_us = READ_ONCE(tp->rcv_rtt_est.rtt_us);
1898 sf_advmss = READ_ONCE(tp->advmss);
1900 rtt_us = max(sf_rtt_us, rtt_us);
1901 advmss = max(sf_advmss, advmss);
1904 msk->rcvq_space.rtt_us = rtt_us;
1905 if (time < (rtt_us >> 3) || rtt_us == 0)
1908 if (msk->rcvq_space.copied <= msk->rcvq_space.space)
1911 if (sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf &&
1912 !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
1916 rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss;
1918 grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space);
1920 do_div(grow, msk->rcvq_space.space);
1921 rcvwin += (grow << 1);
1923 rcvmem = SKB_TRUESIZE(advmss + MAX_TCP_HEADER);
1924 while (tcp_win_from_space(sk, rcvmem) < advmss)
1927 do_div(rcvwin, advmss);
1928 rcvbuf = min_t(u64, rcvwin * rcvmem,
1929 sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
1931 if (rcvbuf > sk->sk_rcvbuf) {
1934 window_clamp = tcp_win_from_space(sk, rcvbuf);
1935 WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
1937 /* Make subflows follow along. If we do not do this, we
1938 * get drops at subflow level if skbs can't be moved to
1939 * the mptcp rx queue fast enough (announced rcv_win can
1940 * exceed ssk->sk_rcvbuf).
1942 mptcp_for_each_subflow(msk, subflow) {
1946 ssk = mptcp_subflow_tcp_sock(subflow);
1947 slow = lock_sock_fast(ssk);
1948 WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf);
1949 tcp_sk(ssk)->window_clamp = window_clamp;
1950 tcp_cleanup_rbuf(ssk, 1);
1951 unlock_sock_fast(ssk, slow);
1956 msk->rcvq_space.space = msk->rcvq_space.copied;
1958 msk->rcvq_space.copied = 0;
1959 msk->rcvq_space.time = mstamp;
1962 static void __mptcp_update_rmem(struct sock *sk)
1964 struct mptcp_sock *msk = mptcp_sk(sk);
1966 if (!msk->rmem_released)
1969 atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc);
1970 mptcp_rmem_uncharge(sk, msk->rmem_released);
1971 WRITE_ONCE(msk->rmem_released, 0);
1974 static void __mptcp_splice_receive_queue(struct sock *sk)
1976 struct mptcp_sock *msk = mptcp_sk(sk);
1978 skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue);
1981 static bool __mptcp_move_skbs(struct mptcp_sock *msk)
1983 struct sock *sk = (struct sock *)msk;
1984 unsigned int moved = 0;
1988 struct sock *ssk = mptcp_subflow_recv_lookup(msk);
1991 /* we can have data pending in the subflows only if the msk
1992 * receive buffer was full at subflow_data_ready() time,
1993 * that is an unlikely slow path.
1998 slowpath = lock_sock_fast(ssk);
1999 mptcp_data_lock(sk);
2000 __mptcp_update_rmem(sk);
2001 done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
2002 mptcp_data_unlock(sk);
2004 if (unlikely(ssk->sk_err))
2005 __mptcp_error_report(sk);
2006 unlock_sock_fast(ssk, slowpath);
2009 /* acquire the data lock only if some input data is pending */
2011 if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) ||
2012 !skb_queue_empty_lockless(&sk->sk_receive_queue)) {
2013 mptcp_data_lock(sk);
2014 __mptcp_update_rmem(sk);
2015 ret |= __mptcp_ofo_queue(msk);
2016 __mptcp_splice_receive_queue(sk);
2017 mptcp_data_unlock(sk);
2020 mptcp_check_data_fin((struct sock *)msk);
2021 return !skb_queue_empty(&msk->receive_queue);
2024 static unsigned int mptcp_inq_hint(const struct sock *sk)
2026 const struct mptcp_sock *msk = mptcp_sk(sk);
2027 const struct sk_buff *skb;
2029 skb = skb_peek(&msk->receive_queue);
2031 u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq;
2033 if (hint_val >= INT_MAX)
2036 return (unsigned int)hint_val;
2039 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
2045 static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
2046 int flags, int *addr_len)
2048 struct mptcp_sock *msk = mptcp_sk(sk);
2049 struct scm_timestamping_internal tss;
2050 int copied = 0, cmsg_flags = 0;
2054 /* MSG_ERRQUEUE is really a no-op till we support IP_RECVERR */
2055 if (unlikely(flags & MSG_ERRQUEUE))
2056 return inet_recv_error(sk, msg, len, addr_len);
2059 if (unlikely(sk->sk_state == TCP_LISTEN)) {
2064 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2066 len = min_t(size_t, len, INT_MAX);
2067 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2069 if (unlikely(msk->recvmsg_inq))
2070 cmsg_flags = MPTCP_CMSG_INQ;
2072 while (copied < len) {
2075 bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags);
2076 if (unlikely(bytes_read < 0)) {
2078 copied = bytes_read;
2082 copied += bytes_read;
2084 /* be sure to advertise window change */
2085 mptcp_cleanup_rbuf(msk);
2087 if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk))
2090 /* only the master socket status is relevant here. The exit
2091 * conditions mirror closely tcp_recvmsg()
2093 if (copied >= target)
2098 sk->sk_state == TCP_CLOSE ||
2099 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2101 signal_pending(current))
2105 copied = sock_error(sk);
2109 if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
2110 mptcp_check_for_eof(msk);
2112 if (sk->sk_shutdown & RCV_SHUTDOWN) {
2113 /* race breaker: the shutdown could be after the
2114 * previous receive queue check
2116 if (__mptcp_move_skbs(msk))
2121 if (sk->sk_state == TCP_CLOSE) {
2131 if (signal_pending(current)) {
2132 copied = sock_intr_errno(timeo);
2137 pr_debug("block timeout %ld", timeo);
2138 sk_wait_data(sk, &timeo, NULL);
2142 if (cmsg_flags && copied >= 0) {
2143 if (cmsg_flags & MPTCP_CMSG_TS)
2144 tcp_recv_timestamp(msg, sk, &tss);
2146 if (cmsg_flags & MPTCP_CMSG_INQ) {
2147 unsigned int inq = mptcp_inq_hint(sk);
2149 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);
2153 pr_debug("msk=%p rx queue empty=%d:%d copied=%d",
2154 msk, skb_queue_empty_lockless(&sk->sk_receive_queue),
2155 skb_queue_empty(&msk->receive_queue), copied);
2156 if (!(flags & MSG_PEEK))
2157 mptcp_rcv_space_adjust(msk, copied);
2163 static void mptcp_retransmit_timer(struct timer_list *t)
2165 struct inet_connection_sock *icsk = from_timer(icsk, t,
2166 icsk_retransmit_timer);
2167 struct sock *sk = &icsk->icsk_inet.sk;
2168 struct mptcp_sock *msk = mptcp_sk(sk);
2171 if (!sock_owned_by_user(sk)) {
2172 /* we need a process context to retransmit */
2173 if (!test_and_set_bit(MPTCP_WORK_RTX, &msk->flags))
2174 mptcp_schedule_work(sk);
2176 /* delegate our work to tcp_release_cb() */
2177 __set_bit(MPTCP_RETRANSMIT, &msk->cb_flags);
2183 static void mptcp_timeout_timer(struct timer_list *t)
2185 struct sock *sk = from_timer(sk, t, sk_timer);
2187 mptcp_schedule_work(sk);
2191 /* Find an idle subflow. Return NULL if there is unacked data at tcp
2194 * A backup subflow is returned only if that is the only kind available.
2196 static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
2198 struct sock *backup = NULL, *pick = NULL;
2199 struct mptcp_subflow_context *subflow;
2200 int min_stale_count = INT_MAX;
2202 sock_owned_by_me((const struct sock *)msk);
2204 if (__mptcp_check_fallback(msk))
2207 mptcp_for_each_subflow(msk, subflow) {
2208 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2210 if (!__mptcp_subflow_active(subflow))
2213 /* still data outstanding at TCP level? skip this */
2214 if (!tcp_rtx_and_write_queues_empty(ssk)) {
2215 mptcp_pm_subflow_chk_stale(msk, ssk);
2216 min_stale_count = min_t(int, min_stale_count, subflow->stale_count);
2220 if (subflow->backup) {
2233 /* use backup only if there are no progresses anywhere */
2234 return min_stale_count > 1 ? backup : NULL;
2237 static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk)
2240 iput(SOCK_INODE(msk->subflow));
2241 msk->subflow = NULL;
2245 bool __mptcp_retransmit_pending_data(struct sock *sk)
2247 struct mptcp_data_frag *cur, *rtx_head;
2248 struct mptcp_sock *msk = mptcp_sk(sk);
2250 if (__mptcp_check_fallback(mptcp_sk(sk)))
2253 if (tcp_rtx_and_write_queues_empty(sk))
2256 /* the closing socket has some data untransmitted and/or unacked:
2257 * some data in the mptcp rtx queue has not really xmitted yet.
2258 * keep it simple and re-inject the whole mptcp level rtx queue
2260 mptcp_data_lock(sk);
2261 __mptcp_clean_una_wakeup(sk);
2262 rtx_head = mptcp_rtx_head(sk);
2264 mptcp_data_unlock(sk);
2268 msk->recovery_snd_nxt = msk->snd_nxt;
2269 msk->recovery = true;
2270 mptcp_data_unlock(sk);
2272 msk->first_pending = rtx_head;
2275 /* be sure to clear the "sent status" on all re-injected fragments */
2276 list_for_each_entry(cur, &msk->rtx_queue, list) {
2277 if (!cur->already_sent)
2279 cur->already_sent = 0;
2285 /* flags for __mptcp_close_ssk() */
2286 #define MPTCP_CF_PUSH BIT(1)
2287 #define MPTCP_CF_FASTCLOSE BIT(2)
2289 /* subflow sockets can be either outgoing (connect) or incoming
2292 * Outgoing subflows use in-kernel sockets.
2293 * Incoming subflows do not have their own 'struct socket' allocated,
2294 * so we need to use tcp_close() after detaching them from the mptcp
2297 static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
2298 struct mptcp_subflow_context *subflow,
2301 struct mptcp_sock *msk = mptcp_sk(sk);
2302 bool need_push, dispose_it;
2304 dispose_it = !msk->subflow || ssk != msk->subflow->sk;
2306 list_del(&subflow->node);
2308 lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
2310 if (flags & MPTCP_CF_FASTCLOSE)
2311 subflow->send_fastclose = 1;
2313 need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk);
2315 tcp_disconnect(ssk, 0);
2316 msk->subflow->state = SS_UNCONNECTED;
2317 mptcp_subflow_ctx_reset(subflow);
2323 /* if we are invoked by the msk cleanup code, the subflow is
2329 subflow->disposable = 1;
2331 /* if ssk hit tcp_done(), tcp_cleanup_ulp() cleared the related ops
2332 * the ssk has been already destroyed, we just need to release the
2333 * reference owned by msk;
2335 if (!inet_csk(ssk)->icsk_ulp_ops) {
2336 kfree_rcu(subflow, rcu);
2338 /* otherwise tcp will dispose of the ssk and subflow ctx */
2339 if (ssk->sk_state == TCP_LISTEN) {
2340 tcp_set_state(ssk, TCP_CLOSE);
2341 mptcp_subflow_queue_clean(ssk);
2342 inet_csk_listen_stop(ssk);
2344 __tcp_close(ssk, 0);
2346 /* close acquired an extra ref */
2353 if (ssk == msk->first)
2357 if (ssk == msk->last_snd)
2358 msk->last_snd = NULL;
2361 __mptcp_push_pending(sk, 0);
2364 void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
2365 struct mptcp_subflow_context *subflow)
2367 if (sk->sk_state == TCP_ESTABLISHED)
2368 mptcp_event(MPTCP_EVENT_SUB_CLOSED, mptcp_sk(sk), ssk, GFP_KERNEL);
2370 /* subflow aborted before reaching the fully_established status
2371 * attempt the creation of the next subflow
2373 mptcp_pm_subflow_check_next(mptcp_sk(sk), ssk, subflow);
2375 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_PUSH);
2378 static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu)
2383 static void __mptcp_close_subflow(struct mptcp_sock *msk)
2385 struct mptcp_subflow_context *subflow, *tmp;
2389 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
2390 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2392 if (inet_sk_state_load(ssk) != TCP_CLOSE)
2395 /* 'subflow_data_ready' will re-sched once rx queue is empty */
2396 if (!skb_queue_empty_lockless(&ssk->sk_receive_queue))
2399 mptcp_close_ssk((struct sock *)msk, ssk, subflow);
2403 static bool mptcp_check_close_timeout(const struct sock *sk)
2405 s32 delta = tcp_jiffies32 - inet_csk(sk)->icsk_mtup.probe_timestamp;
2406 struct mptcp_subflow_context *subflow;
2408 if (delta >= TCP_TIMEWAIT_LEN)
2411 /* if all subflows are in closed status don't bother with additional
2414 mptcp_for_each_subflow(mptcp_sk(sk), subflow) {
2415 if (inet_sk_state_load(mptcp_subflow_tcp_sock(subflow)) !=
2422 static void mptcp_check_fastclose(struct mptcp_sock *msk)
2424 struct mptcp_subflow_context *subflow, *tmp;
2425 struct sock *sk = &msk->sk.icsk_inet.sk;
2427 if (likely(!READ_ONCE(msk->rcv_fastclose)))
2430 mptcp_token_destroy(msk);
2432 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
2433 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
2436 slow = lock_sock_fast(tcp_sk);
2437 if (tcp_sk->sk_state != TCP_CLOSE) {
2438 tcp_send_active_reset(tcp_sk, GFP_ATOMIC);
2439 tcp_set_state(tcp_sk, TCP_CLOSE);
2441 unlock_sock_fast(tcp_sk, slow);
2444 inet_sk_state_store(sk, TCP_CLOSE);
2445 sk->sk_shutdown = SHUTDOWN_MASK;
2446 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
2447 set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags);
2449 mptcp_close_wake_up(sk);
2452 static void __mptcp_retrans(struct sock *sk)
2454 struct mptcp_sock *msk = mptcp_sk(sk);
2455 struct mptcp_sendmsg_info info = {};
2456 struct mptcp_data_frag *dfrag;
2461 mptcp_clean_una_wakeup(sk);
2463 /* first check ssk: need to kick "stale" logic */
2464 ssk = mptcp_subflow_get_retrans(msk);
2465 dfrag = mptcp_rtx_head(sk);
2467 if (mptcp_data_fin_enabled(msk)) {
2468 struct inet_connection_sock *icsk = inet_csk(sk);
2470 icsk->icsk_retransmits++;
2471 mptcp_set_datafin_timeout(sk);
2472 mptcp_send_ack(msk);
2477 if (!mptcp_send_head(sk))
2488 /* limit retransmission to the bytes already sent on some subflows */
2490 info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len : dfrag->already_sent;
2491 while (info.sent < info.limit) {
2492 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
2496 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RETRANSSEGS);
2501 dfrag->already_sent = max(dfrag->already_sent, info.sent);
2502 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
2504 WRITE_ONCE(msk->allow_infinite_fallback, false);
2510 mptcp_check_and_set_pending(sk);
2512 if (!mptcp_timer_pending(sk))
2513 mptcp_reset_timer(sk);
2516 /* schedule the timeout timer for the relevant event: either close timeout
2517 * or mp_fail timeout. The close timeout takes precedence on the mp_fail one
2519 void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout)
2521 struct sock *sk = (struct sock *)msk;
2522 unsigned long timeout, close_timeout;
2524 if (!fail_tout && !sock_flag(sk, SOCK_DEAD))
2527 close_timeout = inet_csk(sk)->icsk_mtup.probe_timestamp - tcp_jiffies32 + jiffies + TCP_TIMEWAIT_LEN;
2529 /* the close timeout takes precedence on the fail one, and here at least one of
2532 timeout = sock_flag(sk, SOCK_DEAD) ? close_timeout : fail_tout;
2534 sk_reset_timer(sk, &sk->sk_timer, timeout);
2537 static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)
2539 struct sock *ssk = msk->first;
2545 pr_debug("MP_FAIL doesn't respond, reset the subflow");
2547 slow = lock_sock_fast(ssk);
2548 mptcp_subflow_reset(ssk);
2549 WRITE_ONCE(mptcp_subflow_ctx(ssk)->fail_tout, 0);
2550 unlock_sock_fast(ssk, slow);
2552 mptcp_reset_timeout(msk, 0);
2555 static void mptcp_worker(struct work_struct *work)
2557 struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
2558 struct sock *sk = &msk->sk.icsk_inet.sk;
2559 unsigned long fail_tout;
2563 state = sk->sk_state;
2564 if (unlikely(state == TCP_CLOSE))
2567 mptcp_check_data_fin_ack(sk);
2569 mptcp_check_fastclose(msk);
2571 mptcp_pm_nl_work(msk);
2573 if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
2574 mptcp_check_for_eof(msk);
2576 __mptcp_check_send_data_fin(sk);
2577 mptcp_check_data_fin(sk);
2579 /* There is no point in keeping around an orphaned sk timedout or
2580 * closed, but we need the msk around to reply to incoming DATA_FIN,
2581 * even if it is orphaned and in FIN_WAIT2 state
2583 if (sock_flag(sk, SOCK_DEAD) &&
2584 (mptcp_check_close_timeout(sk) || sk->sk_state == TCP_CLOSE)) {
2585 inet_sk_state_store(sk, TCP_CLOSE);
2586 __mptcp_destroy_sock(sk);
2590 if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags))
2591 __mptcp_close_subflow(msk);
2593 if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags))
2594 __mptcp_retrans(sk);
2596 fail_tout = msk->first ? READ_ONCE(mptcp_subflow_ctx(msk->first)->fail_tout) : 0;
2597 if (fail_tout && time_after(jiffies, fail_tout))
2598 mptcp_mp_fail_no_response(msk);
2605 static int __mptcp_init_sock(struct sock *sk)
2607 struct mptcp_sock *msk = mptcp_sk(sk);
2609 INIT_LIST_HEAD(&msk->conn_list);
2610 INIT_LIST_HEAD(&msk->join_list);
2611 INIT_LIST_HEAD(&msk->rtx_queue);
2612 INIT_WORK(&msk->work, mptcp_worker);
2613 __skb_queue_head_init(&msk->receive_queue);
2614 msk->out_of_order_queue = RB_ROOT;
2615 msk->first_pending = NULL;
2616 msk->rmem_fwd_alloc = 0;
2617 WRITE_ONCE(msk->rmem_released, 0);
2618 msk->timer_ival = TCP_RTO_MIN;
2621 inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
2622 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
2623 WRITE_ONCE(msk->allow_infinite_fallback, true);
2624 msk->recovery = false;
2626 mptcp_pm_data_init(msk);
2628 /* re-use the csk retrans timer for MPTCP-level retrans */
2629 timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0);
2630 timer_setup(&sk->sk_timer, mptcp_timeout_timer, 0);
2635 static void mptcp_ca_reset(struct sock *sk)
2637 struct inet_connection_sock *icsk = inet_csk(sk);
2639 tcp_assign_congestion_control(sk);
2640 strcpy(mptcp_sk(sk)->ca_name, icsk->icsk_ca_ops->name);
2642 /* no need to keep a reference to the ops, the name will suffice */
2643 tcp_cleanup_congestion_control(sk);
2644 icsk->icsk_ca_ops = NULL;
2647 static int mptcp_init_sock(struct sock *sk)
2649 struct net *net = sock_net(sk);
2652 ret = __mptcp_init_sock(sk);
2656 if (!mptcp_is_enabled(net))
2657 return -ENOPROTOOPT;
2659 if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net))
2662 ret = __mptcp_socket_create(mptcp_sk(sk));
2666 /* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will
2667 * propagate the correct value
2671 sk_sockets_allocated_inc(sk);
2672 sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
2673 sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
2678 static void __mptcp_clear_xmit(struct sock *sk)
2680 struct mptcp_sock *msk = mptcp_sk(sk);
2681 struct mptcp_data_frag *dtmp, *dfrag;
2683 WRITE_ONCE(msk->first_pending, NULL);
2684 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list)
2685 dfrag_clear(sk, dfrag);
2688 static void mptcp_cancel_work(struct sock *sk)
2690 struct mptcp_sock *msk = mptcp_sk(sk);
2692 if (cancel_work_sync(&msk->work))
2696 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
2700 switch (ssk->sk_state) {
2702 if (!(how & RCV_SHUTDOWN))
2706 tcp_disconnect(ssk, O_NONBLOCK);
2709 if (__mptcp_check_fallback(mptcp_sk(sk))) {
2710 pr_debug("Fallback");
2711 ssk->sk_shutdown |= how;
2712 tcp_shutdown(ssk, how);
2714 pr_debug("Sending DATA_FIN on subflow %p", ssk);
2716 if (!mptcp_timer_pending(sk))
2717 mptcp_reset_timer(sk);
2725 static const unsigned char new_state[16] = {
2726 /* current state: new state: action: */
2727 [0 /* (Invalid) */] = TCP_CLOSE,
2728 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2729 [TCP_SYN_SENT] = TCP_CLOSE,
2730 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2731 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
2732 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
2733 [TCP_TIME_WAIT] = TCP_CLOSE, /* should not happen ! */
2734 [TCP_CLOSE] = TCP_CLOSE,
2735 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
2736 [TCP_LAST_ACK] = TCP_LAST_ACK,
2737 [TCP_LISTEN] = TCP_CLOSE,
2738 [TCP_CLOSING] = TCP_CLOSING,
2739 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
2742 static int mptcp_close_state(struct sock *sk)
2744 int next = (int)new_state[sk->sk_state];
2745 int ns = next & TCP_STATE_MASK;
2747 inet_sk_state_store(sk, ns);
2749 return next & TCP_ACTION_FIN;
2752 static void __mptcp_check_send_data_fin(struct sock *sk)
2754 struct mptcp_subflow_context *subflow;
2755 struct mptcp_sock *msk = mptcp_sk(sk);
2757 pr_debug("msk=%p snd_data_fin_enable=%d pending=%d snd_nxt=%llu write_seq=%llu",
2758 msk, msk->snd_data_fin_enable, !!mptcp_send_head(sk),
2759 msk->snd_nxt, msk->write_seq);
2761 /* we still need to enqueue subflows or not really shutting down,
2764 if (!msk->snd_data_fin_enable || msk->snd_nxt + 1 != msk->write_seq ||
2765 mptcp_send_head(sk))
2768 WRITE_ONCE(msk->snd_nxt, msk->write_seq);
2770 /* fallback socket will not get data_fin/ack, can move to the next
2773 if (__mptcp_check_fallback(msk)) {
2774 WRITE_ONCE(msk->snd_una, msk->write_seq);
2775 if ((1 << sk->sk_state) & (TCPF_CLOSING | TCPF_LAST_ACK)) {
2776 inet_sk_state_store(sk, TCP_CLOSE);
2777 mptcp_close_wake_up(sk);
2778 } else if (sk->sk_state == TCP_FIN_WAIT1) {
2779 inet_sk_state_store(sk, TCP_FIN_WAIT2);
2783 mptcp_for_each_subflow(msk, subflow) {
2784 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
2786 mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN);
2790 static void __mptcp_wr_shutdown(struct sock *sk)
2792 struct mptcp_sock *msk = mptcp_sk(sk);
2794 pr_debug("msk=%p snd_data_fin_enable=%d shutdown=%x state=%d pending=%d",
2795 msk, msk->snd_data_fin_enable, sk->sk_shutdown, sk->sk_state,
2796 !!mptcp_send_head(sk));
2798 /* will be ignored by fallback sockets */
2799 WRITE_ONCE(msk->write_seq, msk->write_seq + 1);
2800 WRITE_ONCE(msk->snd_data_fin_enable, 1);
2802 __mptcp_check_send_data_fin(sk);
2805 static void __mptcp_destroy_sock(struct sock *sk)
2807 struct mptcp_subflow_context *subflow, *tmp;
2808 struct mptcp_sock *msk = mptcp_sk(sk);
2809 LIST_HEAD(conn_list);
2811 pr_debug("msk=%p", msk);
2815 /* join list will be eventually flushed (with rst) at sock lock release time*/
2816 list_splice_init(&msk->conn_list, &conn_list);
2818 mptcp_stop_timer(sk);
2819 sk_stop_timer(sk, &sk->sk_timer);
2822 /* clears msk->subflow, allowing the following loop to close
2823 * even the initial subflow
2825 mptcp_dispose_initial_subflow(msk);
2826 list_for_each_entry_safe(subflow, tmp, &conn_list, node) {
2827 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2828 __mptcp_close_ssk(sk, ssk, subflow, 0);
2831 sk->sk_prot->destroy(sk);
2833 WARN_ON_ONCE(msk->rmem_fwd_alloc);
2834 WARN_ON_ONCE(msk->rmem_released);
2835 sk_stream_kill_queues(sk);
2836 xfrm_sk_free_policy(sk);
2838 sk_refcnt_debug_release(sk);
2842 static void mptcp_close(struct sock *sk, long timeout)
2844 struct mptcp_subflow_context *subflow;
2845 struct mptcp_sock *msk = mptcp_sk(sk);
2846 bool do_cancel_work = false;
2849 sk->sk_shutdown = SHUTDOWN_MASK;
2851 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) {
2852 inet_sk_state_store(sk, TCP_CLOSE);
2856 if (mptcp_close_state(sk))
2857 __mptcp_wr_shutdown(sk);
2859 sk_stream_wait_close(sk, timeout);
2862 /* orphan all the subflows */
2863 inet_csk(sk)->icsk_mtup.probe_timestamp = tcp_jiffies32;
2864 mptcp_for_each_subflow(msk, subflow) {
2865 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2866 bool slow = lock_sock_fast_nested(ssk);
2868 /* since the close timeout takes precedence on the fail one,
2871 if (ssk == msk->first)
2872 subflow->fail_tout = 0;
2875 unlock_sock_fast(ssk, slow);
2880 pr_debug("msk=%p state=%d", sk, sk->sk_state);
2881 if (mptcp_sk(sk)->token)
2882 mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);
2884 if (sk->sk_state == TCP_CLOSE) {
2885 __mptcp_destroy_sock(sk);
2886 do_cancel_work = true;
2888 mptcp_reset_timeout(msk, 0);
2892 mptcp_cancel_work(sk);
2897 static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
2899 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2900 const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
2901 struct ipv6_pinfo *msk6 = inet6_sk(msk);
2903 msk->sk_v6_daddr = ssk->sk_v6_daddr;
2904 msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;
2907 msk6->saddr = ssk6->saddr;
2908 msk6->flow_label = ssk6->flow_label;
2912 inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num;
2913 inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport;
2914 inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport;
2915 inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr;
2916 inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr;
2917 inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr;
2920 static int mptcp_disconnect(struct sock *sk, int flags)
2922 struct mptcp_subflow_context *subflow;
2923 struct mptcp_sock *msk = mptcp_sk(sk);
2925 inet_sk_state_store(sk, TCP_CLOSE);
2927 mptcp_for_each_subflow(msk, subflow) {
2928 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2930 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_FASTCLOSE);
2933 mptcp_stop_timer(sk);
2934 sk_stop_timer(sk, &sk->sk_timer);
2936 if (mptcp_sk(sk)->token)
2937 mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL);
2939 mptcp_destroy_common(msk);
2940 msk->last_snd = NULL;
2941 WRITE_ONCE(msk->flags, 0);
2943 msk->push_pending = 0;
2944 msk->recovery = false;
2945 msk->can_ack = false;
2946 msk->fully_established = false;
2947 msk->rcv_data_fin = false;
2948 msk->snd_data_fin_enable = false;
2949 msk->rcv_fastclose = false;
2950 msk->use_64bit_ack = false;
2951 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
2952 mptcp_pm_data_reset(msk);
2955 sk->sk_shutdown = 0;
2956 sk_error_report(sk);
2960 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2961 static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
2963 unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);
2965 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
2969 struct sock *mptcp_sk_clone(const struct sock *sk,
2970 const struct mptcp_options_received *mp_opt,
2971 struct request_sock *req)
2973 struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
2974 struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC);
2975 struct mptcp_sock *msk;
2981 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2982 if (nsk->sk_family == AF_INET6)
2983 inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk);
2986 __mptcp_init_sock(nsk);
2988 msk = mptcp_sk(nsk);
2989 msk->local_key = subflow_req->local_key;
2990 msk->token = subflow_req->token;
2991 msk->subflow = NULL;
2992 WRITE_ONCE(msk->fully_established, false);
2993 if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD)
2994 WRITE_ONCE(msk->csum_enabled, true);
2996 msk->write_seq = subflow_req->idsn + 1;
2997 msk->snd_nxt = msk->write_seq;
2998 msk->snd_una = msk->write_seq;
2999 msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
3000 msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
3002 if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) {
3003 msk->can_ack = true;
3004 msk->remote_key = mp_opt->sndr_key;
3005 mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq);
3007 WRITE_ONCE(msk->ack_seq, ack_seq);
3008 atomic64_set(&msk->rcv_wnd_sent, ack_seq);
3011 sock_reset_flag(nsk, SOCK_RCU_FREE);
3012 /* will be fully established after successful MPC subflow creation */
3013 inet_sk_state_store(nsk, TCP_SYN_RECV);
3015 security_inet_csk_clone(nsk, req);
3016 bh_unlock_sock(nsk);
3018 /* keep a single reference */
3023 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk)
3025 const struct tcp_sock *tp = tcp_sk(ssk);
3027 msk->rcvq_space.copied = 0;
3028 msk->rcvq_space.rtt_us = 0;
3030 msk->rcvq_space.time = tp->tcp_mstamp;
3032 /* initial rcv_space offering made to peer */
3033 msk->rcvq_space.space = min_t(u32, tp->rcv_wnd,
3034 TCP_INIT_CWND * tp->advmss);
3035 if (msk->rcvq_space.space == 0)
3036 msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT;
3038 WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);
3041 static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
3044 struct mptcp_sock *msk = mptcp_sk(sk);
3045 struct socket *listener;
3048 listener = __mptcp_nmpc_socket(msk);
3049 if (WARN_ON_ONCE(!listener)) {
3054 pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));
3055 newsk = inet_csk_accept(listener->sk, flags, err, kern);
3059 pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk));
3060 if (sk_is_mptcp(newsk)) {
3061 struct mptcp_subflow_context *subflow;
3062 struct sock *new_mptcp_sock;
3064 subflow = mptcp_subflow_ctx(newsk);
3065 new_mptcp_sock = subflow->conn;
3067 /* is_mptcp should be false if subflow->conn is missing, see
3068 * subflow_syn_recv_sock()
3070 if (WARN_ON_ONCE(!new_mptcp_sock)) {
3071 tcp_sk(newsk)->is_mptcp = 0;
3075 /* acquire the 2nd reference for the owning socket */
3076 sock_hold(new_mptcp_sock);
3077 newsk = new_mptcp_sock;
3078 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
3080 MPTCP_INC_STATS(sock_net(sk),
3081 MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
3085 newsk->sk_kern_sock = kern;
3089 void mptcp_destroy_common(struct mptcp_sock *msk)
3091 struct sock *sk = (struct sock *)msk;
3093 __mptcp_clear_xmit(sk);
3095 /* move to sk_receive_queue, sk_stream_kill_queues will purge it */
3096 mptcp_data_lock(sk);
3097 skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue);
3098 __skb_queue_purge(&sk->sk_receive_queue);
3099 skb_rbtree_purge(&msk->out_of_order_queue);
3100 mptcp_data_unlock(sk);
3102 /* move all the rx fwd alloc into the sk_mem_reclaim_final in
3103 * inet_sock_destruct() will dispose it
3105 sk->sk_forward_alloc += msk->rmem_fwd_alloc;
3106 msk->rmem_fwd_alloc = 0;
3107 mptcp_token_destroy(msk);
3108 mptcp_pm_free_anno_list(msk);
3109 mptcp_free_local_addr_list(msk);
3112 static void mptcp_destroy(struct sock *sk)
3114 struct mptcp_sock *msk = mptcp_sk(sk);
3116 mptcp_destroy_common(msk);
3117 sk_sockets_allocated_dec(sk);
3120 void __mptcp_data_acked(struct sock *sk)
3122 if (!sock_owned_by_user(sk))
3123 __mptcp_clean_una(sk);
3125 __set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags);
3127 if (mptcp_pending_data_fin_ack(sk))
3128 mptcp_schedule_work(sk);
3131 void __mptcp_check_push(struct sock *sk, struct sock *ssk)
3133 if (!mptcp_send_head(sk))
3136 if (!sock_owned_by_user(sk)) {
3137 struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk));
3139 if (xmit_ssk == ssk)
3140 __mptcp_subflow_push_pending(sk, ssk);
3142 mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), MPTCP_DELEGATE_SEND);
3144 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags);
3148 #define MPTCP_FLAGS_PROCESS_CTX_NEED (BIT(MPTCP_PUSH_PENDING) | \
3149 BIT(MPTCP_RETRANSMIT) | \
3150 BIT(MPTCP_FLUSH_JOIN_LIST))
3152 /* processes deferred events and flush wmem */
3153 static void mptcp_release_cb(struct sock *sk)
3154 __must_hold(&sk->sk_lock.slock)
3156 struct mptcp_sock *msk = mptcp_sk(sk);
3159 unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) |
3164 /* the following actions acquire the subflow socket lock
3166 * 1) can't be invoked in atomic scope
3167 * 2) must avoid ABBA deadlock with msk socket spinlock: the RX
3168 * datapath acquires the msk socket spinlock while helding
3169 * the subflow socket lock
3171 msk->push_pending = 0;
3172 msk->cb_flags &= ~flags;
3173 spin_unlock_bh(&sk->sk_lock.slock);
3174 if (flags & BIT(MPTCP_FLUSH_JOIN_LIST))
3175 __mptcp_flush_join_list(sk);
3176 if (flags & BIT(MPTCP_PUSH_PENDING))
3177 __mptcp_push_pending(sk, 0);
3178 if (flags & BIT(MPTCP_RETRANSMIT))
3179 __mptcp_retrans(sk);
3182 spin_lock_bh(&sk->sk_lock.slock);
3185 if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags))
3186 __mptcp_clean_una_wakeup(sk);
3187 if (unlikely(&msk->cb_flags)) {
3188 /* be sure to set the current sk state before tacking actions
3189 * depending on sk_state, that is processing MPTCP_ERROR_REPORT
3191 if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags))
3192 __mptcp_set_connected(sk);
3193 if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags))
3194 __mptcp_error_report(sk);
3195 if (__test_and_clear_bit(MPTCP_RESET_SCHEDULER, &msk->cb_flags))
3196 msk->last_snd = NULL;
3199 __mptcp_update_rmem(sk);
3202 /* MP_JOIN client subflow must wait for 4th ack before sending any data:
3203 * TCP can't schedule delack timer before the subflow is fully established.
3204 * MPTCP uses the delack timer to do 3rd ack retransmissions
3206 static void schedule_3rdack_retransmission(struct sock *ssk)
3208 struct inet_connection_sock *icsk = inet_csk(ssk);
3209 struct tcp_sock *tp = tcp_sk(ssk);
3210 unsigned long timeout;
3212 if (mptcp_subflow_ctx(ssk)->fully_established)
3215 /* reschedule with a timeout above RTT, as we must look only for drop */
3217 timeout = usecs_to_jiffies(tp->srtt_us >> (3 - 1));
3219 timeout = TCP_TIMEOUT_INIT;
3222 WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER);
3223 icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
3224 icsk->icsk_ack.timeout = timeout;
3225 sk_reset_timer(ssk, &icsk->icsk_delack_timer, timeout);
3228 void mptcp_subflow_process_delegated(struct sock *ssk)
3230 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
3231 struct sock *sk = subflow->conn;
3233 if (test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) {
3234 mptcp_data_lock(sk);
3235 if (!sock_owned_by_user(sk))
3236 __mptcp_subflow_push_pending(sk, ssk);
3238 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags);
3239 mptcp_data_unlock(sk);
3240 mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_SEND);
3242 if (test_bit(MPTCP_DELEGATE_ACK, &subflow->delegated_status)) {
3243 schedule_3rdack_retransmission(ssk);
3244 mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_ACK);
3248 static int mptcp_hash(struct sock *sk)
3250 /* should never be called,
3251 * we hash the TCP subflows not the master socket
3257 static void mptcp_unhash(struct sock *sk)
3259 /* called from sk_common_release(), but nothing to do here */
3262 static int mptcp_get_port(struct sock *sk, unsigned short snum)
3264 struct mptcp_sock *msk = mptcp_sk(sk);
3265 struct socket *ssock;
3267 ssock = __mptcp_nmpc_socket(msk);
3268 pr_debug("msk=%p, subflow=%p", msk, ssock);
3269 if (WARN_ON_ONCE(!ssock))
3272 return inet_csk_get_port(ssock->sk, snum);
3275 void mptcp_finish_connect(struct sock *ssk)
3277 struct mptcp_subflow_context *subflow;
3278 struct mptcp_sock *msk;
3282 subflow = mptcp_subflow_ctx(ssk);
3286 pr_debug("msk=%p, token=%u", sk, subflow->token);
3288 mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq);
3290 subflow->map_seq = ack_seq;
3291 subflow->map_subflow_seq = 1;
3293 /* the socket is not connected yet, no msk/subflow ops can access/race
3294 * accessing the field below
3296 WRITE_ONCE(msk->remote_key, subflow->remote_key);
3297 WRITE_ONCE(msk->local_key, subflow->local_key);
3298 WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
3299 WRITE_ONCE(msk->snd_nxt, msk->write_seq);
3300 WRITE_ONCE(msk->ack_seq, ack_seq);
3301 WRITE_ONCE(msk->can_ack, 1);
3302 WRITE_ONCE(msk->snd_una, msk->write_seq);
3303 atomic64_set(&msk->rcv_wnd_sent, ack_seq);
3305 mptcp_pm_new_connection(msk, ssk, 0);
3307 mptcp_rcv_space_init(msk, ssk);
3310 void mptcp_sock_graft(struct sock *sk, struct socket *parent)
3312 write_lock_bh(&sk->sk_callback_lock);
3313 rcu_assign_pointer(sk->sk_wq, &parent->wq);
3314 sk_set_socket(sk, parent);
3315 sk->sk_uid = SOCK_INODE(parent)->i_uid;
3316 write_unlock_bh(&sk->sk_callback_lock);
3319 bool mptcp_finish_join(struct sock *ssk)
3321 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
3322 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
3323 struct sock *parent = (void *)msk;
3326 pr_debug("msk=%p, subflow=%p", msk, subflow);
3328 /* mptcp socket already closing? */
3329 if (!mptcp_is_fully_established(parent)) {
3330 subflow->reset_reason = MPTCP_RST_EMPTCP;
3334 if (!list_empty(&subflow->node))
3337 if (!mptcp_pm_allow_new_subflow(msk))
3338 goto err_prohibited;
3340 /* active connections are already on conn_list.
3341 * If we can't acquire msk socket lock here, let the release callback
3344 mptcp_data_lock(parent);
3345 if (!sock_owned_by_user(parent)) {
3346 ret = __mptcp_finish_join(msk, ssk);
3349 list_add_tail(&subflow->node, &msk->conn_list);
3353 list_add_tail(&subflow->node, &msk->join_list);
3354 __set_bit(MPTCP_FLUSH_JOIN_LIST, &msk->cb_flags);
3356 mptcp_data_unlock(parent);
3360 subflow->reset_reason = MPTCP_RST_EPROHIBIT;
3364 subflow->map_seq = READ_ONCE(msk->ack_seq);
3365 WRITE_ONCE(msk->allow_infinite_fallback, false);
3368 mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
3372 static void mptcp_shutdown(struct sock *sk, int how)
3374 pr_debug("sk=%p, how=%d", sk, how);
3376 if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk))
3377 __mptcp_wr_shutdown(sk);
3380 static int mptcp_forward_alloc_get(const struct sock *sk)
3382 return sk->sk_forward_alloc + mptcp_sk(sk)->rmem_fwd_alloc;
3385 static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v)
3387 const struct sock *sk = (void *)msk;
3390 if (sk->sk_state == TCP_LISTEN)
3393 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
3396 delta = msk->write_seq - v;
3397 if (__mptcp_check_fallback(msk) && msk->first) {
3398 struct tcp_sock *tp = tcp_sk(msk->first);
3400 /* the first subflow is disconnected after close - see
3401 * __mptcp_close_ssk(). tcp_disconnect() moves the write_seq
3402 * so ignore that status, too.
3404 if (!((1 << msk->first->sk_state) &
3405 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)))
3406 delta += READ_ONCE(tp->write_seq) - tp->snd_una;
3408 if (delta > INT_MAX)
3414 static int mptcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
3416 struct mptcp_sock *msk = mptcp_sk(sk);
3422 if (sk->sk_state == TCP_LISTEN)
3426 __mptcp_move_skbs(msk);
3427 answ = mptcp_inq_hint(sk);
3431 slow = lock_sock_fast(sk);
3432 answ = mptcp_ioctl_outq(msk, READ_ONCE(msk->snd_una));
3433 unlock_sock_fast(sk, slow);
3436 slow = lock_sock_fast(sk);
3437 answ = mptcp_ioctl_outq(msk, msk->snd_nxt);
3438 unlock_sock_fast(sk, slow);
3441 return -ENOIOCTLCMD;
3444 return put_user(answ, (int __user *)arg);
3447 static struct proto mptcp_prot = {
3449 .owner = THIS_MODULE,
3450 .init = mptcp_init_sock,
3451 .disconnect = mptcp_disconnect,
3452 .close = mptcp_close,
3453 .accept = mptcp_accept,
3454 .setsockopt = mptcp_setsockopt,
3455 .getsockopt = mptcp_getsockopt,
3456 .shutdown = mptcp_shutdown,
3457 .destroy = mptcp_destroy,
3458 .sendmsg = mptcp_sendmsg,
3459 .ioctl = mptcp_ioctl,
3460 .recvmsg = mptcp_recvmsg,
3461 .release_cb = mptcp_release_cb,
3463 .unhash = mptcp_unhash,
3464 .get_port = mptcp_get_port,
3465 .forward_alloc_get = mptcp_forward_alloc_get,
3466 .sockets_allocated = &mptcp_sockets_allocated,
3467 .memory_allocated = &tcp_memory_allocated,
3468 .memory_pressure = &tcp_memory_pressure,
3469 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
3470 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
3471 .sysctl_mem = sysctl_tcp_mem,
3472 .obj_size = sizeof(struct mptcp_sock),
3473 .slab_flags = SLAB_TYPESAFE_BY_RCU,
3474 .no_autobind = true,
3477 static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3479 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3480 struct socket *ssock;
3483 lock_sock(sock->sk);
3484 ssock = __mptcp_nmpc_socket(msk);
3490 err = ssock->ops->bind(ssock, uaddr, addr_len);
3492 mptcp_copy_inaddrs(sock->sk, ssock->sk);
3495 release_sock(sock->sk);
3499 static void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
3500 struct mptcp_subflow_context *subflow)
3502 subflow->request_mptcp = 0;
3503 __mptcp_do_fallback(msk);
3506 static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
3507 int addr_len, int flags)
3509 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3510 struct mptcp_subflow_context *subflow;
3511 struct socket *ssock;
3514 lock_sock(sock->sk);
3516 if (addr_len < sizeof(uaddr->sa_family))
3519 if (uaddr->sa_family == AF_UNSPEC) {
3520 err = mptcp_disconnect(sock->sk, flags);
3521 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
3526 if (sock->state != SS_UNCONNECTED && msk->subflow) {
3527 /* pending connection or invalid state, let existing subflow
3530 ssock = msk->subflow;
3534 ssock = __mptcp_nmpc_socket(msk);
3538 mptcp_token_destroy(msk);
3539 inet_sk_state_store(sock->sk, TCP_SYN_SENT);
3540 subflow = mptcp_subflow_ctx(ssock->sk);
3541 #ifdef CONFIG_TCP_MD5SIG
3542 /* no MPTCP if MD5SIG is enabled on this socket or we may run out of
3545 if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
3546 mptcp_subflow_early_fallback(msk, subflow);
3548 if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) {
3549 MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT);
3550 mptcp_subflow_early_fallback(msk, subflow);
3552 if (likely(!__mptcp_check_fallback(msk)))
3553 MPTCP_INC_STATS(sock_net(sock->sk), MPTCP_MIB_MPCAPABLEACTIVE);
3556 err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
3557 sock->state = ssock->state;
3559 /* on successful connect, the msk state will be moved to established by
3560 * subflow_finish_connect()
3562 if (!err || err == -EINPROGRESS)
3563 mptcp_copy_inaddrs(sock->sk, ssock->sk);
3565 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
3568 release_sock(sock->sk);
3572 static int mptcp_listen(struct socket *sock, int backlog)
3574 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3575 struct socket *ssock;
3578 pr_debug("msk=%p", msk);
3580 lock_sock(sock->sk);
3581 ssock = __mptcp_nmpc_socket(msk);
3587 mptcp_token_destroy(msk);
3588 inet_sk_state_store(sock->sk, TCP_LISTEN);
3589 sock_set_flag(sock->sk, SOCK_RCU_FREE);
3591 err = ssock->ops->listen(ssock, backlog);
3592 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
3594 mptcp_copy_inaddrs(sock->sk, ssock->sk);
3597 release_sock(sock->sk);
3601 static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
3602 int flags, bool kern)
3604 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3605 struct socket *ssock;
3608 pr_debug("msk=%p", msk);
3610 ssock = __mptcp_nmpc_socket(msk);
3614 err = ssock->ops->accept(sock, newsock, flags, kern);
3615 if (err == 0 && !mptcp_is_tcpsk(newsock->sk)) {
3616 struct mptcp_sock *msk = mptcp_sk(newsock->sk);
3617 struct mptcp_subflow_context *subflow;
3618 struct sock *newsk = newsock->sk;
3622 /* PM/worker can now acquire the first subflow socket
3623 * lock without racing with listener queue cleanup,
3624 * we can notify it, if needed.
3626 * Even if remote has reset the initial subflow by now
3627 * the refcnt is still at least one.
3629 subflow = mptcp_subflow_ctx(msk->first);
3630 list_add(&subflow->node, &msk->conn_list);
3631 sock_hold(msk->first);
3632 if (mptcp_is_fully_established(newsk))
3633 mptcp_pm_fully_established(msk, msk->first, GFP_KERNEL);
3635 mptcp_copy_inaddrs(newsk, msk->first);
3636 mptcp_rcv_space_init(msk, msk->first);
3637 mptcp_propagate_sndbuf(newsk, msk->first);
3639 /* set ssk->sk_socket of accept()ed flows to mptcp socket.
3640 * This is needed so NOSPACE flag can be set from tcp stack.
3642 mptcp_for_each_subflow(msk, subflow) {
3643 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
3645 if (!ssk->sk_socket)
3646 mptcp_sock_graft(ssk, newsock);
3648 release_sock(newsk);
3654 static __poll_t mptcp_check_readable(struct mptcp_sock *msk)
3656 /* Concurrent splices from sk_receive_queue into receive_queue will
3657 * always show at least one non-empty queue when checked in this order.
3659 if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) &&
3660 skb_queue_empty_lockless(&msk->receive_queue))
3663 return EPOLLIN | EPOLLRDNORM;
3666 static __poll_t mptcp_check_writeable(struct mptcp_sock *msk)
3668 struct sock *sk = (struct sock *)msk;
3670 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
3671 return EPOLLOUT | EPOLLWRNORM;
3673 if (sk_stream_is_writeable(sk))
3674 return EPOLLOUT | EPOLLWRNORM;
3676 mptcp_set_nospace(sk);
3677 smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */
3678 if (sk_stream_is_writeable(sk))
3679 return EPOLLOUT | EPOLLWRNORM;
3684 static __poll_t mptcp_poll(struct file *file, struct socket *sock,
3685 struct poll_table_struct *wait)
3687 struct sock *sk = sock->sk;
3688 struct mptcp_sock *msk;
3693 sock_poll_wait(file, sock, wait);
3695 state = inet_sk_state_load(sk);
3696 pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags);
3697 if (state == TCP_LISTEN) {
3698 if (WARN_ON_ONCE(!msk->subflow || !msk->subflow->sk))
3701 return inet_csk_listen_poll(msk->subflow->sk);
3704 if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) {
3705 mask |= mptcp_check_readable(msk);
3706 mask |= mptcp_check_writeable(msk);
3708 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
3710 if (sk->sk_shutdown & RCV_SHUTDOWN)
3711 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
3713 /* This barrier is coupled with smp_wmb() in tcp_reset() */
3721 static const struct proto_ops mptcp_stream_ops = {
3723 .owner = THIS_MODULE,
3724 .release = inet_release,
3726 .connect = mptcp_stream_connect,
3727 .socketpair = sock_no_socketpair,
3728 .accept = mptcp_stream_accept,
3729 .getname = inet_getname,
3731 .ioctl = inet_ioctl,
3732 .gettstamp = sock_gettstamp,
3733 .listen = mptcp_listen,
3734 .shutdown = inet_shutdown,
3735 .setsockopt = sock_common_setsockopt,
3736 .getsockopt = sock_common_getsockopt,
3737 .sendmsg = inet_sendmsg,
3738 .recvmsg = inet_recvmsg,
3739 .mmap = sock_no_mmap,
3740 .sendpage = inet_sendpage,
3743 static struct inet_protosw mptcp_protosw = {
3744 .type = SOCK_STREAM,
3745 .protocol = IPPROTO_MPTCP,
3746 .prot = &mptcp_prot,
3747 .ops = &mptcp_stream_ops,
3748 .flags = INET_PROTOSW_ICSK,
3751 static int mptcp_napi_poll(struct napi_struct *napi, int budget)
3753 struct mptcp_delegated_action *delegated;
3754 struct mptcp_subflow_context *subflow;
3757 delegated = container_of(napi, struct mptcp_delegated_action, napi);
3758 while ((subflow = mptcp_subflow_delegated_next(delegated)) != NULL) {
3759 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
3761 bh_lock_sock_nested(ssk);
3762 if (!sock_owned_by_user(ssk) &&
3763 mptcp_subflow_has_delegated_action(subflow))
3764 mptcp_subflow_process_delegated(ssk);
3765 /* ... elsewhere tcp_release_cb_override already processed
3766 * the action or will do at next release_sock().
3767 * In both case must dequeue the subflow here - on the same
3768 * CPU that scheduled it.
3770 bh_unlock_sock(ssk);
3773 if (++work_done == budget)
3777 /* always provide a 0 'work_done' argument, so that napi_complete_done
3778 * will not try accessing the NULL napi->dev ptr
3780 napi_complete_done(napi, 0);
3784 void __init mptcp_proto_init(void)
3786 struct mptcp_delegated_action *delegated;
3789 mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;
3791 if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL))
3792 panic("Failed to allocate MPTCP pcpu counter\n");
3794 init_dummy_netdev(&mptcp_napi_dev);
3795 for_each_possible_cpu(cpu) {
3796 delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu);
3797 INIT_LIST_HEAD(&delegated->head);
3798 netif_napi_add_tx(&mptcp_napi_dev, &delegated->napi,
3800 napi_enable(&delegated->napi);
3803 mptcp_subflow_init();
3807 if (proto_register(&mptcp_prot, 1) != 0)
3808 panic("Failed to register MPTCP proto.\n");
3810 inet_register_protosw(&mptcp_protosw);
3812 BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, cb));
3815 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
3816 static const struct proto_ops mptcp_v6_stream_ops = {
3818 .owner = THIS_MODULE,
3819 .release = inet6_release,
3821 .connect = mptcp_stream_connect,
3822 .socketpair = sock_no_socketpair,
3823 .accept = mptcp_stream_accept,
3824 .getname = inet6_getname,
3826 .ioctl = inet6_ioctl,
3827 .gettstamp = sock_gettstamp,
3828 .listen = mptcp_listen,
3829 .shutdown = inet_shutdown,
3830 .setsockopt = sock_common_setsockopt,
3831 .getsockopt = sock_common_getsockopt,
3832 .sendmsg = inet6_sendmsg,
3833 .recvmsg = inet6_recvmsg,
3834 .mmap = sock_no_mmap,
3835 .sendpage = inet_sendpage,
3836 #ifdef CONFIG_COMPAT
3837 .compat_ioctl = inet6_compat_ioctl,
3841 static struct proto mptcp_v6_prot;
3843 static void mptcp_v6_destroy(struct sock *sk)
3846 inet6_destroy_sock(sk);
3849 static struct inet_protosw mptcp_v6_protosw = {
3850 .type = SOCK_STREAM,
3851 .protocol = IPPROTO_MPTCP,
3852 .prot = &mptcp_v6_prot,
3853 .ops = &mptcp_v6_stream_ops,
3854 .flags = INET_PROTOSW_ICSK,
3857 int __init mptcp_proto_v6_init(void)
3861 mptcp_v6_prot = mptcp_prot;
3862 strcpy(mptcp_v6_prot.name, "MPTCPv6");
3863 mptcp_v6_prot.slab = NULL;
3864 mptcp_v6_prot.destroy = mptcp_v6_destroy;
3865 mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock);
3867 err = proto_register(&mptcp_v6_prot, 1);
3871 err = inet6_register_protosw(&mptcp_v6_protosw);
3873 proto_unregister(&mptcp_v6_prot);