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tcp: Fix data-races around sk_pacing_rate.
[linux-block.git] / net / mptcp / protocol.c
CommitLineData
f870fa0b
MM		 1// SPDX-License-Identifier: GPL-2.0
2/* Multipath TCP
3 *
4 * Copyright (c) 2017 - 2019, Intel Corporation.
5 */
6
7#define pr_fmt(fmt) "MPTCP: " fmt
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/netdevice.h>
7a6a6cbc
PA		 12#include <linux/sched/signal.h>
13#include <linux/atomic.h>
f870fa0b
MM		 14#include <net/sock.h>
15#include <net/inet_common.h>
16#include <net/inet_hashtables.h>
17#include <net/protocol.h>
18#include <net/tcp.h>
3721b9b6 19#include <net/tcp_states.h>
cf7da0d6
PK		 20#if IS_ENABLED(CONFIG_MPTCP_IPV6)
21#include <net/transp_v6.h>
22#endif
f870fa0b 23#include <net/mptcp.h>
e16163b6 24#include <net/xfrm.h>
644807e3 25#include <asm/ioctls.h>
f870fa0b 26#include "protocol.h"
fc518953 27#include "mib.h"
f870fa0b 28
e10a9892
GT		 29#define CREATE_TRACE_POINTS
30#include <trace/events/mptcp.h>
31
b0519de8
FW		 32#if IS_ENABLED(CONFIG_MPTCP_IPV6)
33struct mptcp6_sock {
34 struct mptcp_sock msk;
35 struct ipv6_pinfo np;
36};
37#endif
38
6771bfd9 39struct mptcp_skb_cb {
ab174ad8
PA		 40 u64 map_seq;
41 u64 end_seq;
6771bfd9 42 u32 offset;
b7f653b2 43 u8 has_rxtstamp:1;
6771bfd9
FW		 44};
45
46#define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0]))
47
b7f653b2
FW		 48enum {
49 MPTCP_CMSG_TS = BIT(0),
2c9e7765 50 MPTCP_CMSG_INQ = BIT(1),
b7f653b2
FW		 51};
52
91b6d325 53static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp;
d027236c 54
e16163b6 55static void __mptcp_destroy_sock(struct sock *sk);
d9ca1de8 56static void __mptcp_check_send_data_fin(struct sock *sk);
e16163b6 57
b19bc294
PA		 58DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
59static struct net_device mptcp_napi_dev;
60
2303f994
PK		 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.
64 */
1729cf18 65struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk)
2303f994 66{
d22f4988 67 if (!msk->subflow || READ_ONCE(msk->can_ack))
2303f994
PK		 68 return NULL;
69
70 return msk->subflow;
71}
72
6f8a612a
FW		 73/* Returns end sequence number of the receiver's advertised window */
74static u64 mptcp_wnd_end(const struct mptcp_sock *msk)
75{
7439d687 76 return READ_ONCE(msk->wnd_end);
6f8a612a
FW		 77}
78
d2f77c53 79static bool mptcp_is_tcpsk(struct sock *sk)
0b4f33de
FW		 80{
81 struct socket *sock = sk->sk_socket;
82
0b4f33de
FW		 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,
86 * not an mptcp one.
87 *
88 * Hand the socket over to tcp so all further socket ops
89 * bypass mptcp.
90 */
91 sock->ops = &inet_stream_ops;
d2f77c53 92 return true;
0b4f33de
FW		 93#if IS_ENABLED(CONFIG_MPTCP_IPV6)
94 } else if (unlikely(sk->sk_prot == &tcpv6_prot)) {
95 sock->ops = &inet6_stream_ops;
d2f77c53 96 return true;
0b4f33de
FW		 97#endif
98 }
99
d2f77c53 100 return false;
0b4f33de
FW		 101}
102
fa68018d 103static int __mptcp_socket_create(struct mptcp_sock *msk)
2303f994
PK		 104{
105 struct mptcp_subflow_context *subflow;
106 struct sock *sk = (struct sock *)msk;
107 struct socket *ssock;
108 int err;
109
2303f994
PK		 110 err = mptcp_subflow_create_socket(sk, &ssock);
111 if (err)
fa68018d 112 return err;
2303f994 113
8ab183de 114 msk->first = ssock->sk;
2303f994
PK		 115 msk->subflow = ssock;
116 subflow = mptcp_subflow_ctx(ssock->sk);
cec37a6e 117 list_add(&subflow->node, &msk->conn_list);
e16163b6 118 sock_hold(ssock->sk);
2303f994 119 subflow->request_mptcp = 1;
4cf86ae8
PA		 120
121 /* This is the first subflow, always with id 0 */
122 subflow->local_id_valid = 1;
866f26f2 123 mptcp_sock_graft(msk->first, sk->sk_socket);
e1ff9e82 124
fa68018d 125 return 0;
2303f994
PK		 126}
127
ab174ad8
PA		 128static void mptcp_drop(struct sock *sk, struct sk_buff *skb)
129{
130 sk_drops_add(sk, skb);
131 __kfree_skb(skb);
132}
133
6511882c
PA		 134static void mptcp_rmem_charge(struct sock *sk, int size)
135{
136 mptcp_sk(sk)->rmem_fwd_alloc -= size;
137}
138
8268ed4c
PA		 139static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
140 struct sk_buff *from)
141{
142 bool fragstolen;
143 int delta;
144
145 if (MPTCP_SKB_CB(from)->offset ||
146 !skb_try_coalesce(to, from, &fragstolen, &delta))
147 return false;
148
06242e44
PA		 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);
ab174ad8 152 MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq;
8268ed4c
PA		 153 kfree_skb_partial(from, fragstolen);
154 atomic_add(delta, &sk->sk_rmem_alloc);
6511882c 155 mptcp_rmem_charge(sk, delta);
8268ed4c
PA		 156 return true;
157}
158
ab174ad8
PA		 159static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to,
160 struct sk_buff *from)
161{
162 if (MPTCP_SKB_CB(from)->map_seq != MPTCP_SKB_CB(to)->end_seq)
163 return false;
164
165 return mptcp_try_coalesce((struct sock *)msk, to, from);
166}
167
6511882c
PA		 168static void __mptcp_rmem_reclaim(struct sock *sk, int amount)
169{
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);
173}
174
175static void mptcp_rmem_uncharge(struct sock *sk, int size)
176{
177 struct mptcp_sock *msk = mptcp_sk(sk);
178 int reclaimable;
179
180 msk->rmem_fwd_alloc += size;
181 reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
182
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);
186}
187
188static void mptcp_rfree(struct sk_buff *skb)
189{
190 unsigned int len = skb->truesize;
191 struct sock *sk = skb->sk;
192
193 atomic_sub(len, &sk->sk_rmem_alloc);
194 mptcp_rmem_uncharge(sk, len);
195}
196
197static void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk)
198{
199 skb_orphan(skb);
200 skb->sk = sk;
201 skb->destructor = mptcp_rfree;
202 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
203 mptcp_rmem_charge(sk, skb->truesize);
204}
205
ab174ad8
PA		 206/* "inspired" by tcp_data_queue_ofo(), main differences:
207 * - use mptcp seqs
208 * - don't cope with sacks
209 */
210static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
211{
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;
216
217 seq = MPTCP_SKB_CB(skb)->map_seq;
218 end_seq = MPTCP_SKB_CB(skb)->end_seq;
f3589be0 219 max_seq = atomic64_read(&msk->rcv_wnd_sent);
ab174ad8 220
06242e44
PA		 221 pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq,
222 RB_EMPTY_ROOT(&msk->out_of_order_queue));
fa3fe2b1 223 if (after64(end_seq, max_seq)) {
ab174ad8
PA		 224 /* out of window */
225 mptcp_drop(sk, skb);
fa3fe2b1
FW		 226 pr_debug("oow by %lld, rcv_wnd_sent %llu\n",
227 (unsigned long long)end_seq - (unsigned long)max_seq,
f3589be0 228 (unsigned long long)atomic64_read(&msk->rcv_wnd_sent));
06242e44 229 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW);
ab174ad8
PA		 230 return;
231 }
232
233 p = &msk->out_of_order_queue.rb_node;
06242e44 234 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE);
ab174ad8
PA		 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;
239 goto end;
240 }
241
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.
244 */
06242e44
PA		 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);
ab174ad8 248 return;
06242e44 249 }
ab174ad8
PA		 250
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)) {
06242e44 253 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
ab174ad8
PA		 254 parent = &msk->ooo_last_skb->rbnode;
255 p = &parent->rb_right;
256 goto insert;
257 }
258
259 /* Find place to insert this segment. Handle overlaps on the way. */
260 parent = NULL;
261 while (*p) {
262 parent = *p;
263 skb1 = rb_to_skb(parent);
264 if (before64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
265 p = &parent->rb_left;
266 continue;
267 }
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. */
271 mptcp_drop(sk, skb);
06242e44 272 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 273 return;
274 }
275 if (after64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
276 /* partial overlap:
277 * | skb |
278 * | skb1 |
279 * continue traversing
280 */
281 } else {
282 /* skb's seq == skb1's seq and skb covers skb1.
283 * Replace skb1 with skb.
284 */
285 rb_replace_node(&skb1->rbnode, &skb->rbnode,
286 &msk->out_of_order_queue);
287 mptcp_drop(sk, skb1);
06242e44 288 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 289 goto merge_right;
290 }
291 } else if (mptcp_ooo_try_coalesce(msk, skb1, skb)) {
06242e44 292 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
ab174ad8
PA		 293 return;
294 }
295 p = &parent->rb_right;
296 }
06242e44 297
ab174ad8
PA		 298insert:
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);
302
303merge_right:
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))
307 break;
308 rb_erase(&skb1->rbnode, &msk->out_of_order_queue);
309 mptcp_drop(sk, skb1);
06242e44 310 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 311 }
312 /* If there is no skb after us, we are the last_skb ! */
313 if (!skb1)
314 msk->ooo_last_skb = skb;
315
316end:
317 skb_condense(skb);
6511882c
PA		 318 mptcp_set_owner_r(skb, sk);
319}
320
321static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
322{
323 struct mptcp_sock *msk = mptcp_sk(sk);
324 int amt, amount;
325
326 if (size < msk->rmem_fwd_alloc)
327 return true;
328
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;
335 return false;
336 }
337
338 ssk->sk_forward_alloc -= amount;
339 }
340 return true;
ab174ad8
PA		 341}
342
343static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
344 struct sk_buff *skb, unsigned int offset,
345 size_t copy_len)
6771bfd9 346{
ab174ad8 347 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
6771bfd9 348 struct sock *sk = (struct sock *)msk;
4e637c70 349 struct sk_buff *tail;
b7f653b2 350 bool has_rxtstamp;
6771bfd9
FW		 351
352 __skb_unlink(skb, &ssk->sk_receive_queue);
6771bfd9 353
4e637c70
FW		 354 skb_ext_reset(skb);
355 skb_orphan(skb);
ab174ad8 356
9c3f94e1 357 /* try to fetch required memory from subflow */
6511882c
PA		 358 if (!mptcp_rmem_schedule(sk, ssk, skb->truesize))
359 goto drop;
9c3f94e1 360
b7f653b2
FW		 361 has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp;
362
ab174ad8
PA		 363 /* the skb map_seq accounts for the skb offset:
364 * mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq
365 * value
366 */
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;
8268ed4c 369 MPTCP_SKB_CB(skb)->offset = offset;
b7f653b2 370 MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp;
4e637c70 371
ab174ad8
PA		 372 if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) {
373 /* in sequence */
8b0308fe 374 WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len);
ab174ad8
PA		 375 tail = skb_peek_tail(&sk->sk_receive_queue);
376 if (tail && mptcp_try_coalesce(sk, tail, skb))
377 return true;
4e637c70 378
6511882c 379 mptcp_set_owner_r(skb, sk);
ab174ad8
PA		 380 __skb_queue_tail(&sk->sk_receive_queue, skb);
381 return true;
382 } else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) {
383 mptcp_data_queue_ofo(msk, skb);
384 return false;
385 }
386
387 /* old data, keep it simple and drop the whole pkt, sender
388 * will retransmit as needed, if needed.
389 */
06242e44 390 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
9c3f94e1 391drop:
ab174ad8
PA		 392 mptcp_drop(sk, skb);
393 return false;
6771bfd9
FW		 394}
395
16a9a9da
MM		 396static void mptcp_stop_timer(struct sock *sk)
397{
398 struct inet_connection_sock *icsk = inet_csk(sk);
399
400 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
401 mptcp_sk(sk)->timer_ival = 0;
402}
403
e16163b6
PA		 404static void mptcp_close_wake_up(struct sock *sk)
405{
406 if (sock_flag(sk, SOCK_DEAD))
407 return;
408
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);
413 else
414 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
415}
416
6e628cd3 417static bool mptcp_pending_data_fin_ack(struct sock *sk)
16a9a9da
MM		 418{
419 struct mptcp_sock *msk = mptcp_sk(sk);
420
6e628cd3
PA		 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);
425}
426
427static void mptcp_check_data_fin_ack(struct sock *sk)
428{
429 struct mptcp_sock *msk = mptcp_sk(sk);
16a9a9da
MM		 430
431 /* Look for an acknowledged DATA_FIN */
6e628cd3 432 if (mptcp_pending_data_fin_ack(sk)) {
16a9a9da
MM		 433 WRITE_ONCE(msk->snd_data_fin_enable, 0);
434
435 switch (sk->sk_state) {
436 case TCP_FIN_WAIT1:
437 inet_sk_state_store(sk, TCP_FIN_WAIT2);
16a9a9da
MM		 438 break;
439 case TCP_CLOSING:
16a9a9da
MM		 440 case TCP_LAST_ACK:
441 inet_sk_state_store(sk, TCP_CLOSE);
16a9a9da
MM		 442 break;
443 }
444
e16163b6 445 mptcp_close_wake_up(sk);
16a9a9da
MM		 446 }
447}
448
3721b9b6
MM		 449static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq)
450{
451 struct mptcp_sock *msk = mptcp_sk(sk);
452
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);
457
458 if (msk->ack_seq == rcv_data_fin_seq) {
459 if (seq)
460 *seq = rcv_data_fin_seq;
461
462 return true;
463 }
464 }
465
466 return false;
467}
468
6477dd39
MM		 469static void mptcp_set_datafin_timeout(const struct sock *sk)
470{
471 struct inet_connection_sock *icsk = inet_csk(sk);
877d11f0 472 u32 retransmits;
6477dd39 473
877d11f0
MM		 474 retransmits = min_t(u32, icsk->icsk_retransmits,
475 ilog2(TCP_RTO_MAX / TCP_RTO_MIN));
476
477 mptcp_sk(sk)->timer_ival = TCP_RTO_MIN << retransmits;
6477dd39
MM		 478}
479
33d41c9c 480static void __mptcp_set_timeout(struct sock *sk, long tout)
3721b9b6 481{
3721b9b6
MM		 482 mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN;
483}
484
33d41c9c
PA		 485static long mptcp_timeout_from_subflow(const struct mptcp_subflow_context *subflow)
486{
487 const struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
488
71b7dec2
PA		 489 return inet_csk(ssk)->icsk_pending && !subflow->stale_count ?
490 inet_csk(ssk)->icsk_timeout - jiffies : 0;
33d41c9c
PA		 491}
492
493static void mptcp_set_timeout(struct sock *sk)
494{
495 struct mptcp_subflow_context *subflow;
496 long tout = 0;
497
498 mptcp_for_each_subflow(mptcp_sk(sk), subflow)
499 tout = max(tout, mptcp_timeout_from_subflow(subflow));
500 __mptcp_set_timeout(sk, tout);
501}
502
76a13b31 503static inline bool tcp_can_send_ack(const struct sock *ssk)
fd897679
PA		 504{
505 return !((1 << inet_sk_state_load(ssk)) &
20bc80b6 506 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN));
fd897679
PA		 507}
508
a6574302
MM		 509void __mptcp_subflow_send_ack(struct sock *ssk)
510{
511 if (tcp_can_send_ack(ssk))
512 tcp_send_ack(ssk);
513}
514
340fa666
MM		 515void mptcp_subflow_send_ack(struct sock *ssk)
516{
517 bool slow;
518
519 slow = lock_sock_fast(ssk);
a6574302 520 __mptcp_subflow_send_ack(ssk);
340fa666
MM		 521 unlock_sock_fast(ssk, slow);
522}
523
fd897679 524static void mptcp_send_ack(struct mptcp_sock *msk)
7ed90803
PA		 525{
526 struct mptcp_subflow_context *subflow;
527
340fa666
MM		 528 mptcp_for_each_subflow(msk, subflow)
529 mptcp_subflow_send_ack(mptcp_subflow_tcp_sock(subflow));
fd897679
PA		 530}
531
fde56eea 532static void mptcp_subflow_cleanup_rbuf(struct sock *ssk)
fd897679 533{
75e908c3 534 bool slow;
fd897679 535
75e908c3 536 slow = lock_sock_fast(ssk);
fde56eea 537 if (tcp_can_send_ack(ssk))
fd897679 538 tcp_cleanup_rbuf(ssk, 1);
75e908c3 539 unlock_sock_fast(ssk, slow);
fde56eea
PA		 540}
541
542static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_empty)
543{
544 const struct inet_connection_sock *icsk = inet_csk(ssk);
c4512c63 545 u8 ack_pending = READ_ONCE(icsk->icsk_ack.pending);
fde56eea
PA		 546 const struct tcp_sock *tp = tcp_sk(ssk);
547
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)));
fd897679
PA		 553}
554
555static void mptcp_cleanup_rbuf(struct mptcp_sock *msk)
556{
e3859603 557 int old_space = READ_ONCE(msk->old_wspace);
fd897679 558 struct mptcp_subflow_context *subflow;
e3859603 559 struct sock *sk = (struct sock *)msk;
fde56eea
PA		 560 int space = __mptcp_space(sk);
561 bool cleanup, rx_empty;
e3859603 562
fde56eea 563 cleanup = (space > 0) && (space >= (old_space << 1));
ce599c51 564 rx_empty = !__mptcp_rmem(sk);
fd897679 565
fde56eea
PA		 566 mptcp_for_each_subflow(msk, subflow) {
567 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
fd897679 568
fde56eea
PA		 569 if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty))
570 mptcp_subflow_cleanup_rbuf(ssk);
7ed90803
PA		 571 }
572}
573
574static bool mptcp_check_data_fin(struct sock *sk)
3721b9b6
MM		 575{
576 struct mptcp_sock *msk = mptcp_sk(sk);
577 u64 rcv_data_fin_seq;
7ed90803 578 bool ret = false;
3721b9b6 579
781bf13d 580 if (__mptcp_check_fallback(msk))
7ed90803 581 return ret;
3721b9b6
MM		 582
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
588 * the msk state.
589 *
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
593 * when catching up.
594 */
595
596 if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) {
917944da 597 WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1);
3721b9b6
MM		 598 WRITE_ONCE(msk->rcv_data_fin, 0);
599
600 sk->sk_shutdown |= RCV_SHUTDOWN;
16a9a9da 601 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
3721b9b6
MM		 602
603 switch (sk->sk_state) {
604 case TCP_ESTABLISHED:
605 inet_sk_state_store(sk, TCP_CLOSE_WAIT);
606 break;
607 case TCP_FIN_WAIT1:
608 inet_sk_state_store(sk, TCP_CLOSING);
609 break;
610 case TCP_FIN_WAIT2:
611 inet_sk_state_store(sk, TCP_CLOSE);
3721b9b6
MM		 612 break;
613 default:
614 /* Other states not expected */
615 WARN_ON_ONCE(1);
616 break;
617 }
618
7ed90803 619 ret = true;
fd897679 620 mptcp_send_ack(msk);
e16163b6 621 mptcp_close_wake_up(sk);
3721b9b6 622 }
7ed90803 623 return ret;
3721b9b6
MM		 624}
625
6771bfd9
FW		 626static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
627 struct sock *ssk,
628 unsigned int *bytes)
629{
630 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
600911ff 631 struct sock *sk = (struct sock *)msk;
6771bfd9
FW		 632 unsigned int moved = 0;
633 bool more_data_avail;
634 struct tcp_sock *tp;
635 bool done = false;
13c7ba0c
FW		 636 int sk_rbuf;
637
638 sk_rbuf = READ_ONCE(sk->sk_rcvbuf);
639
640 if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
641 int ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf);
642
643 if (unlikely(ssk_rbuf > sk_rbuf)) {
644 WRITE_ONCE(sk->sk_rcvbuf, ssk_rbuf);
645 sk_rbuf = ssk_rbuf;
646 }
647 }
600911ff 648
ab174ad8 649 pr_debug("msk=%p ssk=%p", msk, ssk);
6771bfd9
FW		 650 tp = tcp_sk(ssk);
651 do {
652 u32 map_remaining, offset;
653 u32 seq = tp->copied_seq;
654 struct sk_buff *skb;
655 bool fin;
656
657 /* try to move as much data as available */
658 map_remaining = subflow->map_data_len -
659 mptcp_subflow_get_map_offset(subflow);
660
661 skb = skb_peek(&ssk->sk_receive_queue);
d9fb8c50
PA		 662 if (!skb) {
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
666 */
667 if (!moved)
668 done = true;
6771bfd9 669 break;
d9fb8c50 670 }
6771bfd9 671
e1ff9e82
DC		 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
676 */
677 map_remaining = skb->len;
678 subflow->map_data_len = skb->len;
679 }
680
6771bfd9
FW		 681 offset = seq - TCP_SKB_CB(skb)->seq;
682 fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
683 if (fin) {
684 done = true;
685 seq++;
686 }
687
688 if (offset < skb->len) {
689 size_t len = skb->len - offset;
690
691 if (tp->urg_data)
692 done = true;
693
ab174ad8
PA		 694 if (__mptcp_move_skb(msk, ssk, skb, offset, len))
695 moved += len;
6771bfd9 696 seq += len;
6771bfd9
FW		 697
698 if (WARN_ON_ONCE(map_remaining < len))
699 break;
700 } else {
701 WARN_ON_ONCE(!fin);
702 sk_eat_skb(ssk, skb);
703 done = true;
704 }
705
706 WRITE_ONCE(tp->copied_seq, seq);
707 more_data_avail = mptcp_subflow_data_available(ssk);
600911ff 708
13c7ba0c 709 if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) {
600911ff
FW		 710 done = true;
711 break;
712 }
6771bfd9
FW		 713 } while (more_data_avail);
714
6719331c 715 *bytes += moved;
6771bfd9
FW		 716 return done;
717}
718
87952603 719static bool __mptcp_ofo_queue(struct mptcp_sock *msk)
ab174ad8
PA		 720{
721 struct sock *sk = (struct sock *)msk;
722 struct sk_buff *skb, *tail;
723 bool moved = false;
724 struct rb_node *p;
725 u64 end_seq;
726
727 p = rb_first(&msk->out_of_order_queue);
06242e44 728 pr_debug("msk=%p empty=%d", msk, RB_EMPTY_ROOT(&msk->out_of_order_queue));
ab174ad8
PA		 729 while (p) {
730 skb = rb_to_skb(p);
731 if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq))
732 break;
733
734 p = rb_next(p);
735 rb_erase(&skb->rbnode, &msk->out_of_order_queue);
736
737 if (unlikely(!after64(MPTCP_SKB_CB(skb)->end_seq,
738 msk->ack_seq))) {
739 mptcp_drop(sk, skb);
06242e44 740 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 741 continue;
742 }
743
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;
748
749 /* skip overlapping data, if any */
06242e44
PA		 750 pr_debug("uncoalesced seq=%llx ack seq=%llx delta=%d",
751 MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq,
752 delta);
ab174ad8 753 MPTCP_SKB_CB(skb)->offset += delta;
2c9e7765 754 MPTCP_SKB_CB(skb)->map_seq += delta;
ab174ad8
PA		 755 __skb_queue_tail(&sk->sk_receive_queue, skb);
756 }
757 msk->ack_seq = end_seq;
758 moved = true;
759 }
760 return moved;
761}
762
2e52213c
FW		 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.
765 */
99d1055c 766static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
2e52213c
FW		 767{
768 struct sock *sk = (struct sock *)msk;
769 unsigned int moved = 0;
770
87952603
PA		 771 __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
772 __mptcp_ofo_queue(msk);
499ada50
PA		 773 if (unlikely(ssk->sk_err)) {
774 if (!sock_owned_by_user(sk))
775 __mptcp_error_report(sk);
776 else
e9d09bac 777 __set_bit(MPTCP_ERROR_REPORT, &msk->cb_flags);
499ada50 778 }
2e52213c 779
87952603
PA		 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
783 * do it.
784 */
785 if (mptcp_pending_data_fin(sk, NULL))
786 mptcp_schedule_work(sk);
99d1055c 787 return moved > 0;
2e52213c
FW		 788}
789
790void mptcp_data_ready(struct sock *sk, struct sock *ssk)
101f6f85 791{
6719331c 792 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
101f6f85 793 struct mptcp_sock *msk = mptcp_sk(sk);
13c7ba0c 794 int sk_rbuf, ssk_rbuf;
101f6f85 795
d7b1bfd0
PA		 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
799 */
800 if (unlikely(subflow->disposable))
801 return;
802
13c7ba0c
FW		 803 ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf);
804 sk_rbuf = READ_ONCE(sk->sk_rcvbuf);
805 if (unlikely(ssk_rbuf > sk_rbuf))
806 sk_rbuf = ssk_rbuf;
807
99d1055c 808 /* over limit? can't append more skbs to msk, Also, no need to wake-up*/
ce599c51
PA		 809 if (__mptcp_rmem(sk) > sk_rbuf) {
810 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
99d1055c 811 return;
ce599c51 812 }
600911ff 813
99d1055c
PA		 814 /* Wake-up the reader only for in-sequence data */
815 mptcp_data_lock(sk);
612f71d7 816 if (move_skbs_to_msk(msk, ssk))
6719331c 817 sk->sk_data_ready(sk);
612f71d7 818
99d1055c 819 mptcp_data_unlock(sk);
101f6f85
FW		 820}
821
3e501490 822static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
ec3edaa7 823{
3e501490 824 struct sock *sk = (struct sock *)msk;
5cf92bba 825
3e501490 826 if (sk->sk_state != TCP_ESTABLISHED)
78962489 827 return false;
ec3edaa7 828
3e501490
PA		 829 /* attach to msk socket only after we are sure we will deal with it
830 * at close time
831 */
832 if (sk->sk_socket && !ssk->sk_socket)
833 mptcp_sock_graft(ssk, sk->sk_socket);
78962489 834
3e501490
PA		 835 mptcp_propagate_sndbuf((struct sock *)msk, ssk);
836 mptcp_sockopt_sync_locked(msk, ssk);
837 return true;
78962489
FW		 838}
839
3e501490 840static void __mptcp_flush_join_list(struct sock *sk)
78962489 841{
3e501490
PA		 842 struct mptcp_subflow_context *tmp, *subflow;
843 struct mptcp_sock *msk = mptcp_sk(sk);
78962489 844
3e501490
PA		 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);
78962489 848
3e501490
PA		 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);
853 }
ec3edaa7
PK		 854}
855
b51f9b80
PA		 856static bool mptcp_timer_pending(struct sock *sk)
857{
858 return timer_pending(&inet_csk(sk)->icsk_retransmit_timer);
859}
860
861static void mptcp_reset_timer(struct sock *sk)
862{
863 struct inet_connection_sock *icsk = inet_csk(sk);
864 unsigned long tout;
865
e16163b6
PA		 866 /* prevent rescheduling on close */
867 if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE))
868 return;
869
33d41c9c 870 tout = mptcp_sk(sk)->timer_ival;
b51f9b80
PA		 871 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout);
872}
873
ba8f48f7
PA		 874bool mptcp_schedule_work(struct sock *sk)
875{
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.
880 */
881 sock_hold(sk);
882 return true;
883 }
884 return false;
885}
886
59832e24
FW		 887void mptcp_subflow_eof(struct sock *sk)
888{
ba8f48f7
PA		 889 if (!test_and_set_bit(MPTCP_WORK_EOF, &mptcp_sk(sk)->flags))
890 mptcp_schedule_work(sk);
59832e24
FW		 891}
892
5969856a
PA		 893static void mptcp_check_for_eof(struct mptcp_sock *msk)
894{
895 struct mptcp_subflow_context *subflow;
896 struct sock *sk = (struct sock *)msk;
897 int receivers = 0;
898
899 mptcp_for_each_subflow(msk, subflow)
900 receivers += !subflow->rx_eof;
e16163b6
PA		 901 if (receivers)
902 return;
5969856a 903
e16163b6 904 if (!(sk->sk_shutdown & RCV_SHUTDOWN)) {
5969856a
PA		 905 /* hopefully temporary hack: propagate shutdown status
906 * to msk, when all subflows agree on it
907 */
908 sk->sk_shutdown |= RCV_SHUTDOWN;
909
910 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
5969856a
PA		 911 sk->sk_data_ready(sk);
912 }
e16163b6
PA		 913
914 switch (sk->sk_state) {
915 case TCP_ESTABLISHED:
916 inet_sk_state_store(sk, TCP_CLOSE_WAIT);
917 break;
918 case TCP_FIN_WAIT1:
26aa2314
PA		 919 inet_sk_state_store(sk, TCP_CLOSING);
920 break;
921 case TCP_FIN_WAIT2:
e16163b6
PA		 922 inet_sk_state_store(sk, TCP_CLOSE);
923 break;
924 default:
925 return;
926 }
927 mptcp_close_wake_up(sk);
5969856a
PA		 928}
929
7a6a6cbc
PA		 930static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
931{
932 struct mptcp_subflow_context *subflow;
933 struct sock *sk = (struct sock *)msk;
934
935 sock_owned_by_me(sk);
936
937 mptcp_for_each_subflow(msk, subflow) {
99d1055c 938 if (READ_ONCE(subflow->data_avail))
7a6a6cbc
PA		 939 return mptcp_subflow_tcp_sock(subflow);
940 }
941
942 return NULL;
943}
944
3f8e0aae
PA		 945static bool mptcp_skb_can_collapse_to(u64 write_seq,
946 const struct sk_buff *skb,
947 const struct mptcp_ext *mpext)
57040755
PA		 948{
949 if (!tcp_skb_can_collapse_to(skb))
950 return false;
951
5a369ca6
PA		 952 /* can collapse only if MPTCP level sequence is in order and this
953 * mapping has not been xmitted yet
954 */
955 return mpext && mpext->data_seq + mpext->data_len == write_seq &&
956 !mpext->frozen;
57040755
PA		 957}
958
29249eac
PA		 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
963 */
18b683bf
PA		 964static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
965 const struct page_frag *pfrag,
966 const struct mptcp_data_frag *df)
967{
968 return df && pfrag->page == df->page &&
d9ca1de8 969 pfrag->size - pfrag->offset > 0 &&
29249eac 970 pfrag->offset == (df->offset + df->data_len) &&
18b683bf
PA		 971 df->data_seq + df->data_len == msk->write_seq;
972}
973
6511882c 974static void __mptcp_mem_reclaim_partial(struct sock *sk)
e93da928 975{
6511882c 976 int reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
e93da928 977
765ff425 978 lockdep_assert_held_once(&sk->sk_lock.slock);
b5941f06 979
269bda9e
MM		 980 if (reclaimable > SK_MEM_QUANTUM)
981 __mptcp_rmem_reclaim(sk, reclaimable - 1);
982
1094c6fe
PA		 983 sk_mem_reclaim_partial(sk);
984}
985
724cfd2e
PA		 986static void mptcp_mem_reclaim_partial(struct sock *sk)
987{
724cfd2e 988 mptcp_data_lock(sk);
6511882c 989 __mptcp_mem_reclaim_partial(sk);
724cfd2e
PA		 990 mptcp_data_unlock(sk);
991}
992
d027236c
PA		 993static void dfrag_uncharge(struct sock *sk, int len)
994{
995 sk_mem_uncharge(sk, len);
7948f6cc 996 sk_wmem_queued_add(sk, -len);
d027236c
PA		 997}
998
999static void dfrag_clear(struct sock *sk, struct mptcp_data_frag *dfrag)
18b683bf 1000{
d027236c
PA		 1001 int len = dfrag->data_len + dfrag->overhead;
1002
18b683bf 1003 list_del(&dfrag->list);
d027236c 1004 dfrag_uncharge(sk, len);
18b683bf
PA		 1005 put_page(dfrag->page);
1006}
1007
6e628cd3 1008static void __mptcp_clean_una(struct sock *sk)
18b683bf
PA		 1009{
1010 struct mptcp_sock *msk = mptcp_sk(sk);
1011 struct mptcp_data_frag *dtmp, *dfrag;
d027236c 1012 bool cleaned = false;
e1ff9e82
DC		 1013 u64 snd_una;
1014
1015 /* on fallback we just need to ignore snd_una, as this is really
1016 * plain TCP
1017 */
1018 if (__mptcp_check_fallback(msk))
7439d687 1019 msk->snd_una = READ_ONCE(msk->snd_nxt);
6f8a612a 1020
7439d687 1021 snd_una = msk->snd_una;
18b683bf
PA		 1022 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) {
1023 if (after64(dfrag->data_seq + dfrag->data_len, snd_una))
1024 break;
1025
1e1d9d6f
PA		 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))
1029 break;
1030
1031 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1032 }
1033
d027236c
PA		 1034 dfrag_clear(sk, dfrag);
1035 cleaned = true;
1036 }
1037
7948f6cc
FW		 1038 dfrag = mptcp_rtx_head(sk);
1039 if (dfrag && after64(snd_una, dfrag->data_seq)) {
53eb4c38
PA		 1040 u64 delta = snd_una - dfrag->data_seq;
1041
1e1d9d6f
PA		 1042 /* prevent wrap around in recovery mode */
1043 if (unlikely(delta > dfrag->already_sent)) {
1044 if (WARN_ON_ONCE(!msk->recovery))
1045 goto out;
1046 if (WARN_ON_ONCE(delta > dfrag->data_len))
1047 goto out;
1048 dfrag->already_sent += delta - dfrag->already_sent;
1049 }
7948f6cc
FW		 1050
1051 dfrag->data_seq += delta;
53eb4c38 1052 dfrag->offset += delta;
7948f6cc 1053 dfrag->data_len -= delta;
d9ca1de8 1054 dfrag->already_sent -= delta;
7948f6cc
FW		 1055
1056 dfrag_uncharge(sk, delta);
1057 cleaned = true;
1058 }
1059
1e1d9d6f
PA		 1060 /* all retransmitted data acked, recovery completed */
1061 if (unlikely(msk->recovery) && after64(msk->snd_una, msk->recovery_snd_nxt))
1062 msk->recovery = false;
1063
53eb4c38 1064out:
1094c6fe
PA		 1065 if (cleaned && tcp_under_memory_pressure(sk))
1066 __mptcp_mem_reclaim_partial(sk);
95ed690e 1067
3241a9c0
FW		 1068 if (snd_una == READ_ONCE(msk->snd_nxt) &&
1069 snd_una == READ_ONCE(msk->write_seq)) {
33d41c9c 1070 if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk))
6e628cd3
PA		 1071 mptcp_stop_timer(sk);
1072 } else {
1073 mptcp_reset_timer(sk);
18b683bf
PA		 1074 }
1075}
1076
417789df
PA		 1077static void __mptcp_clean_una_wakeup(struct sock *sk)
1078{
765ff425
PA		 1079 lockdep_assert_held_once(&sk->sk_lock.slock);
1080
417789df
PA		 1081 __mptcp_clean_una(sk);
1082 mptcp_write_space(sk);
1083}
1084
b5941f06
PA		 1085static void mptcp_clean_una_wakeup(struct sock *sk)
1086{
1087 mptcp_data_lock(sk);
1088 __mptcp_clean_una_wakeup(sk);
1089 mptcp_data_unlock(sk);
1090}
1091
724cfd2e 1092static void mptcp_enter_memory_pressure(struct sock *sk)
18b683bf 1093{
d9ca1de8
PA		 1094 struct mptcp_subflow_context *subflow;
1095 struct mptcp_sock *msk = mptcp_sk(sk);
1096 bool first = true;
1097
18b683bf 1098 sk_stream_moderate_sndbuf(sk);
d9ca1de8
PA		 1099 mptcp_for_each_subflow(msk, subflow) {
1100 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
1101
1102 if (first)
1103 tcp_enter_memory_pressure(ssk);
1104 sk_stream_moderate_sndbuf(ssk);
1105 first = false;
1106 }
724cfd2e
PA		 1107}
1108
1109/* ensure we get enough memory for the frag hdr, beyond some minimal amount of
1110 * data
1111 */
1112static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1113{
1114 if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
1115 pfrag, sk->sk_allocation)))
1116 return true;
1117
1118 mptcp_enter_memory_pressure(sk);
18b683bf
PA		 1119 return false;
1120}
1121
1122static struct mptcp_data_frag *
1123mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
1124 int orig_offset)
1125{
1126 int offset = ALIGN(orig_offset, sizeof(long));
1127 struct mptcp_data_frag *dfrag;
1128
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);
d9ca1de8 1134 dfrag->already_sent = 0;
18b683bf
PA		 1135 dfrag->page = pfrag->page;
1136
1137 return dfrag;
1138}
1139
caf971df
PA		 1140struct mptcp_sendmsg_info {
1141 int mss_now;
1142 int size_goal;
d9ca1de8
PA		 1143 u16 limit;
1144 u16 sent;
1145 unsigned int flags;
1094c6fe 1146 bool data_lock_held;
caf971df
PA		 1147};
1148
b713d006
PA		 1149static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *ssk,
1150 u64 data_seq, int avail_size)
6f8a612a
FW		 1151{
1152 u64 window_end = mptcp_wnd_end(msk);
b713d006 1153 u64 mptcp_snd_wnd;
6f8a612a
FW		 1154
1155 if (__mptcp_check_fallback(msk))
1156 return avail_size;
1157
b713d006
PA		 1158 mptcp_snd_wnd = window_end - data_seq;
1159 avail_size = min_t(unsigned int, mptcp_snd_wnd, avail_size);
6f8a612a 1160
92be2f52 1161 if (unlikely(tcp_sk(ssk)->snd_wnd < mptcp_snd_wnd)) {
b713d006 1162 tcp_sk(ssk)->snd_wnd = min_t(u64, U32_MAX, mptcp_snd_wnd);
92be2f52
PA		 1163 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_SNDWNDSHARED);
1164 }
6f8a612a
FW		 1165
1166 return avail_size;
1167}
1168
724cfd2e
PA		 1169static bool __mptcp_add_ext(struct sk_buff *skb, gfp_t gfp)
1170{
1171 struct skb_ext *mpext = __skb_ext_alloc(gfp);
1172
1173 if (!mpext)
1174 return false;
1175 __skb_ext_set(skb, SKB_EXT_MPTCP, mpext);
1176 return true;
1177}
1178
6e628cd3 1179static struct sk_buff *__mptcp_do_alloc_tx_skb(struct sock *sk, gfp_t gfp)
724cfd2e
PA		 1180{
1181 struct sk_buff *skb;
1182
6e628cd3 1183 skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp);
724cfd2e 1184 if (likely(skb)) {
6e628cd3 1185 if (likely(__mptcp_add_ext(skb, gfp))) {
724cfd2e 1186 skb_reserve(skb, MAX_TCP_HEADER);
a52fe46e 1187 skb->ip_summed = CHECKSUM_PARTIAL;
f70cad10 1188 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
724cfd2e
PA		 1189 return skb;
1190 }
1191 __kfree_skb(skb);
1192 } else {
1193 mptcp_enter_memory_pressure(sk);
1194 }
1195 return NULL;
1196}
1197
f70cad10 1198static struct sk_buff *__mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp)
724cfd2e 1199{
724cfd2e
PA		 1200 struct sk_buff *skb;
1201
6e628cd3 1202 skb = __mptcp_do_alloc_tx_skb(sk, gfp);
724cfd2e 1203 if (!skb)
f70cad10 1204 return NULL;
724cfd2e
PA		 1205
1206 if (likely(sk_wmem_schedule(ssk, skb->truesize))) {
f70cad10
PA		 1207 tcp_skb_entail(ssk, skb);
1208 return skb;
724cfd2e 1209 }
3ef3905a 1210 tcp_skb_tsorted_anchor_cleanup(skb);
724cfd2e 1211 kfree_skb(skb);
f70cad10 1212 return NULL;
724cfd2e
PA		 1213}
1214
f70cad10 1215static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, bool data_lock_held)
724cfd2e 1216{
1094c6fe 1217 gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation;
724cfd2e 1218
1094c6fe
PA		 1219 if (unlikely(tcp_under_memory_pressure(sk))) {
1220 if (data_lock_held)
1221 __mptcp_mem_reclaim_partial(sk);
1222 else
1223 mptcp_mem_reclaim_partial(sk);
1224 }
1225 return __mptcp_alloc_tx_skb(sk, ssk, gfp);
724cfd2e
PA		 1226}
1227
d0cc2987
GT		 1228/* note: this always recompute the csum on the whole skb, even
1229 * if we just appended a single frag. More status info needed
1230 */
1231static void mptcp_update_data_checksum(struct sk_buff *skb, int added)
1232{
1233 struct mptcp_ext *mpext = mptcp_get_ext(skb);
1234 __wsum csum = ~csum_unfold(mpext->csum);
1235 int offset = skb->len - added;
1236
1237 mpext->csum = csum_fold(csum_block_add(csum, skb_checksum(skb, offset, added, 0), offset));
1238}
1239
1e39e5a3
GT		 1240static void mptcp_update_infinite_map(struct mptcp_sock *msk,
1241 struct sock *ssk,
1242 struct mptcp_ext *mpext)
1243{
1244 if (!mpext)
1245 return;
1246
1247 mpext->infinite_map = 1;
1248 mpext->data_len = 0;
1249
104125b8 1250 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX);
1e39e5a3
GT		 1251 mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
1252 pr_fallback(msk);
d51991e2 1253 mptcp_do_fallback(ssk);
1e39e5a3
GT		 1254}
1255
6d0060f6 1256static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
d9ca1de8 1257 struct mptcp_data_frag *dfrag,
caf971df 1258 struct mptcp_sendmsg_info *info)
6d0060f6 1259{
d9ca1de8 1260 u64 data_seq = dfrag->data_seq + info->sent;
f70cad10 1261 int offset = dfrag->offset + info->sent;
6d0060f6 1262 struct mptcp_sock *msk = mptcp_sk(sk);
6f8a612a 1263 bool zero_window_probe = false;
6d0060f6 1264 struct mptcp_ext *mpext = NULL;
f70cad10
PA		 1265 bool can_coalesce = false;
1266 bool reuse_skb = true;
1267 struct sk_buff *skb;
1268 size_t copy;
1269 int i;
6d0060f6 1270
e4b61351 1271 pr_debug("msk=%p ssk=%p sending dfrag at seq=%llu len=%u already sent=%u",
d9ca1de8
PA		 1272 msk, ssk, dfrag->data_seq, dfrag->data_len, info->sent);
1273
f70cad10
PA		 1274 if (WARN_ON_ONCE(info->sent > info->limit ||
1275 info->limit > dfrag->data_len))
1276 return 0;
1277
d9ca1de8
PA		 1278 /* compute send limit */
1279 info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags);
f70cad10
PA		 1280 copy = info->size_goal;
1281
57040755 1282 skb = tcp_write_queue_tail(ssk);
f70cad10 1283 if (skb && copy > skb->len) {
57040755
PA		 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
1289 */
d9ca1de8 1290 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
1094c6fe 1291 if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) {
57040755 1292 TCP_SKB_CB(skb)->eor = 1;
1094c6fe
PA		 1293 goto alloc_skb;
1294 }
1295
f70cad10
PA		 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);
1300 goto alloc_skb;
15e6ca97 1301 }
18b683bf 1302
f70cad10
PA		 1303 copy -= skb->len;
1304 } else {
1094c6fe 1305alloc_skb:
f70cad10
PA		 1306 skb = mptcp_alloc_tx_skb(sk, ssk, info->data_lock_held);
1307 if (!skb)
1308 return -ENOMEM;
1309
1310 i = skb_shinfo(skb)->nr_frags;
1311 reuse_skb = false;
1312 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
1313 }
1094c6fe 1314
6f8a612a 1315 /* Zero window and all data acked? Probe. */
b713d006 1316 copy = mptcp_check_allowed_size(msk, ssk, data_seq, copy);
f70cad10 1317 if (copy == 0) {
7439d687
PA		 1318 u64 snd_una = READ_ONCE(msk->snd_una);
1319
f70cad10 1320 if (snd_una != msk->snd_nxt) {
27728ba8 1321 tcp_remove_empty_skb(ssk);
6f8a612a 1322 return 0;
f70cad10
PA		 1323 }
1324
6f8a612a 1325 zero_window_probe = true;
7439d687 1326 data_seq = snd_una - 1;
f70cad10 1327 copy = 1;
6f8a612a 1328
f70cad10
PA		 1329 /* all mptcp-level data is acked, no skbs should be present into the
1330 * ssk write queue
1331 */
1332 WARN_ON_ONCE(reuse_skb);
1333 }
d027236c 1334
f70cad10
PA		 1335 copy = min_t(size_t, copy, info->limit - info->sent);
1336 if (!sk_wmem_schedule(ssk, copy)) {
27728ba8 1337 tcp_remove_empty_skb(ssk);
e2223995 1338 return -ENOMEM;
35759383 1339 }
18b683bf 1340
f70cad10
PA		 1341 if (can_coalesce) {
1342 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1343 } else {
1344 get_page(dfrag->page);
1345 skb_fill_page_desc(skb, i, dfrag->page, offset, copy);
57040755
PA		 1346 }
1347
f70cad10
PA		 1348 skb->len += copy;
1349 skb->data_len += copy;
1350 skb->truesize += copy;
1351 sk_wmem_queued_add(ssk, copy);
1352 sk_mem_charge(ssk, copy);
f70cad10
PA		 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);
1356
1357 /* on skb reuse we just need to update the DSS len */
1358 if (reuse_skb) {
1359 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1360 mpext->data_len += copy;
1361 WARN_ON_ONCE(zero_window_probe);
1362 goto out;
724cfd2e 1363 }
6d0060f6
MM		 1364
1365 memset(mpext, 0, sizeof(*mpext));
d9ca1de8 1366 mpext->data_seq = data_seq;
6d0060f6 1367 mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq;
f70cad10 1368 mpext->data_len = copy;
6d0060f6
MM		 1369 mpext->use_map = 1;
1370 mpext->dsn64 = 1;
1371
1372 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d",
1373 mpext->data_seq, mpext->subflow_seq, mpext->data_len,
1374 mpext->dsn64);
1375
6f8a612a 1376 if (zero_window_probe) {
f70cad10 1377 mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
6f8a612a 1378 mpext->frozen = 1;
d0cc2987 1379 if (READ_ONCE(msk->csum_enabled))
f70cad10 1380 mptcp_update_data_checksum(skb, copy);
6f8a612a 1381 tcp_push_pending_frames(ssk);
d0cc2987 1382 return 0;
6f8a612a 1383 }
57040755 1384out:
d0cc2987 1385 if (READ_ONCE(msk->csum_enabled))
f70cad10 1386 mptcp_update_data_checksum(skb, copy);
1e39e5a3
GT		 1387 if (mptcp_subflow_ctx(ssk)->send_infinite_map)
1388 mptcp_update_infinite_map(msk, ssk, mpext);
0eb4e7ee 1389 trace_mptcp_sendmsg_frag(mpext);
f70cad10
PA		 1390 mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
1391 return copy;
6d0060f6
MM		 1392}
1393
d5f49190
PA		 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))
1399
1400struct subflow_send_info {
1401 struct sock *ssk;
3ce0852c 1402 u64 linger_time;
d5f49190
PA		 1403};
1404
ff5a0b42
PA		 1405void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow)
1406{
1407 if (!subflow->stale)
1408 return;
1409
1410 subflow->stale = 0;
fc1b4e3b 1411 MPTCP_INC_STATS(sock_net(mptcp_subflow_tcp_sock(subflow)), MPTCP_MIB_SUBFLOWRECOVER);
ff5a0b42
PA		 1412}
1413
1414bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
1415{
1416 if (unlikely(subflow->stale)) {
1417 u32 rcv_tstamp = READ_ONCE(tcp_sk(mptcp_subflow_tcp_sock(subflow))->rcv_tstamp);
1418
1419 if (subflow->stale_rcv_tstamp == rcv_tstamp)
1420 return false;
1421
1422 mptcp_subflow_set_active(subflow);
1423 }
1424 return __mptcp_subflow_active(subflow);
1425}
1426
3ce0852c
PA		 1427#define SSK_MODE_ACTIVE 0
1428#define SSK_MODE_BACKUP 1
1429#define SSK_MODE_MAX 2
1430
33d41c9c
PA		 1431/* implement the mptcp packet scheduler;
1432 * returns the subflow that will transmit the next DSS
1433 * additionally updates the rtx timeout
1434 */
5cf92bba 1435static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
f296234c 1436{
3ce0852c 1437 struct subflow_send_info send_info[SSK_MODE_MAX];
f296234c 1438 struct mptcp_subflow_context *subflow;
33d41c9c 1439 struct sock *sk = (struct sock *)msk;
3ce0852c 1440 u32 pace, burst, wmem;
d5f49190
PA		 1441 int i, nr_active = 0;
1442 struct sock *ssk;
3ce0852c 1443 u64 linger_time;
33d41c9c 1444 long tout = 0;
f296234c 1445
33d41c9c 1446 sock_owned_by_me(sk);
f296234c 1447
d5f49190
PA		 1448 if (__mptcp_check_fallback(msk)) {
1449 if (!msk->first)
f296234c 1450 return NULL;
d5f49190
PA		 1451 return sk_stream_memory_free(msk->first) ? msk->first : NULL;
1452 }
1453
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) &&
33d41c9c
PA		 1457 mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) {
1458 mptcp_set_timeout(sk);
d5f49190 1459 return msk->last_snd;
33d41c9c 1460 }
f296234c 1461
d5f49190 1462 /* pick the subflow with the lower wmem/wspace ratio */
3ce0852c 1463 for (i = 0; i < SSK_MODE_MAX; ++i) {
d5f49190 1464 send_info[i].ssk = NULL;
3ce0852c 1465 send_info[i].linger_time = -1;
d5f49190 1466 }
3ce0852c 1467
d5f49190 1468 mptcp_for_each_subflow(msk, subflow) {
e10a9892 1469 trace_mptcp_subflow_get_send(subflow);
d5f49190
PA		 1470 ssk = mptcp_subflow_tcp_sock(subflow);
1471 if (!mptcp_subflow_active(subflow))
1472 continue;
1473
33d41c9c 1474 tout = max(tout, mptcp_timeout_from_subflow(subflow));
d5f49190 1475 nr_active += !subflow->backup;
3ce0852c
PA		 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;
1481 if (!pace)
1482 continue;
1483 }
f296234c 1484
3ce0852c
PA		 1485 linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace);
1486 if (linger_time < send_info[subflow->backup].linger_time) {
d5f49190 1487 send_info[subflow->backup].ssk = ssk;
3ce0852c 1488 send_info[subflow->backup].linger_time = linger_time;
d5f49190 1489 }
f296234c 1490 }
33d41c9c 1491 __mptcp_set_timeout(sk, tout);
f296234c 1492
d5f49190
PA		 1493 /* pick the best backup if no other subflow is active */
1494 if (!nr_active)
3ce0852c
PA		 1495 send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk;
1496
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.
1507 */
1508 ssk = send_info[SSK_MODE_ACTIVE].ssk;
b713d006 1509 if (!ssk || !sk_stream_memory_free(ssk))
3ce0852c 1510 return NULL;
5cf92bba 1511
b713d006 1512 burst = min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
3ce0852c 1513 wmem = READ_ONCE(ssk->sk_wmem_queued);
b713d006
PA		 1514 if (!burst) {
1515 msk->last_snd = NULL;
1516 return ssk;
1517 }
1518
3ce0852c
PA		 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,
1522 burst + wmem);
1523 msk->last_snd = ssk;
1524 msk->snd_burst = burst;
1525 return ssk;
f296234c
PK		 1526}
1527
b8e0def3 1528static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info)
d9ca1de8 1529{
d9ca1de8
PA		 1530 tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal);
1531 release_sock(ssk);
1532}
1533
0d199e43
FW		 1534static void mptcp_update_post_push(struct mptcp_sock *msk,
1535 struct mptcp_data_frag *dfrag,
1536 u32 sent)
1537{
1538 u64 snd_nxt_new = dfrag->data_seq;
1539
1540 dfrag->already_sent += sent;
1541
1542 msk->snd_burst -= sent;
0d199e43
FW		 1543
1544 snd_nxt_new += dfrag->already_sent;
1545
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
1548 * old segments.
1549 *
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.
1554 */
1555 if (likely(after64(snd_nxt_new, msk->snd_nxt)))
1556 msk->snd_nxt = snd_nxt_new;
1557}
1558
8b38217a 1559void mptcp_check_and_set_pending(struct sock *sk)
3241a9c0 1560{
e9d09bac
PA		 1561 if (mptcp_send_head(sk))
1562 mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING);
3241a9c0
FW		 1563}
1564
ff5a0b42 1565void __mptcp_push_pending(struct sock *sk, unsigned int flags)
f870fa0b 1566{
d9ca1de8 1567 struct sock *prev_ssk = NULL, *ssk = NULL;
f870fa0b 1568 struct mptcp_sock *msk = mptcp_sk(sk);
caf971df 1569 struct mptcp_sendmsg_info info = {
d9ca1de8 1570 .flags = flags,
caf971df 1571 };
d9ca1de8
PA		 1572 struct mptcp_data_frag *dfrag;
1573 int len, copied = 0;
d9ca1de8
PA		 1574
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;
1579 while (len > 0) {
1580 int ret = 0;
1581
1582 prev_ssk = ssk;
5cf92bba 1583 ssk = mptcp_subflow_get_send(msk);
d9ca1de8 1584
9758f40e
PA		 1585 /* First check. If the ssk has changed since
1586 * the last round, release prev_ssk
d9ca1de8
PA		 1587 */
1588 if (ssk != prev_ssk && prev_ssk)
b8e0def3 1589 mptcp_push_release(prev_ssk, &info);
d9ca1de8
PA		 1590 if (!ssk)
1591 goto out;
1592
9758f40e
PA		 1593 /* Need to lock the new subflow only if different
1594 * from the previous one, otherwise we are still
1595 * helding the relevant lock
1596 */
1597 if (ssk != prev_ssk)
d9ca1de8
PA		 1598 lock_sock(ssk);
1599
1600 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
1601 if (ret <= 0) {
b8e0def3 1602 mptcp_push_release(ssk, &info);
d9ca1de8
PA		 1603 goto out;
1604 }
1605
1606 info.sent += ret;
d9ca1de8
PA		 1607 copied += ret;
1608 len -= ret;
0d199e43
FW		 1609
1610 mptcp_update_post_push(msk, dfrag, ret);
d9ca1de8
PA		 1611 }
1612 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1613 }
1614
1615 /* at this point we held the socket lock for the last subflow we used */
1616 if (ssk)
b8e0def3 1617 mptcp_push_release(ssk, &info);
d9ca1de8
PA		 1618
1619out:
33d41c9c
PA		 1620 /* ensure the rtx timer is running */
1621 if (!mptcp_timer_pending(sk))
1622 mptcp_reset_timer(sk);
1623 if (copied)
d9ca1de8
PA		 1624 __mptcp_check_send_data_fin(sk);
1625}
1626
6e628cd3
PA		 1627static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk)
1628{
1629 struct mptcp_sock *msk = mptcp_sk(sk);
1094c6fe
PA		 1630 struct mptcp_sendmsg_info info = {
1631 .data_lock_held = true,
1632 };
6e628cd3 1633 struct mptcp_data_frag *dfrag;
b19bc294 1634 struct sock *xmit_ssk;
6e628cd3 1635 int len, copied = 0;
b19bc294 1636 bool first = true;
6e628cd3
PA		 1637
1638 info.flags = 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;
1643 while (len > 0) {
1644 int ret = 0;
1645
b19bc294
PA		 1646 /* the caller already invoked the packet scheduler,
1647 * check for a different subflow usage only after
1648 * spooling the first chunk of data
1649 */
1650 xmit_ssk = first ? ssk : mptcp_subflow_get_send(mptcp_sk(sk));
1651 if (!xmit_ssk)
1652 goto out;
1653 if (xmit_ssk != ssk) {
bcd97734
PA		 1654 mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk),
1655 MPTCP_DELEGATE_SEND);
b19bc294
PA		 1656 goto out;
1657 }
1658
6e628cd3
PA		 1659 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
1660 if (ret <= 0)
1661 goto out;
1662
1663 info.sent += ret;
6e628cd3
PA		 1664 copied += ret;
1665 len -= ret;
b19bc294 1666 first = false;
0d199e43
FW		 1667
1668 mptcp_update_post_push(msk, dfrag, ret);
6e628cd3
PA		 1669 }
1670 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1671 }
1672
1673out:
1674 /* __mptcp_alloc_tx_skb could have released some wmem and we are
1675 * not going to flush it via release_sock()
1676 */
6e628cd3 1677 if (copied) {
6e628cd3
PA		 1678 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
1679 info.size_goal);
d09d818e
PA		 1680 if (!mptcp_timer_pending(sk))
1681 mptcp_reset_timer(sk);
1682
6e628cd3
PA		 1683 if (msk->snd_data_fin_enable &&
1684 msk->snd_nxt + 1 == msk->write_seq)
1685 mptcp_schedule_work(sk);
1686 }
1687}
1688
5cf92bba
PA		 1689static void mptcp_set_nospace(struct sock *sk)
1690{
1691 /* enable autotune */
1692 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1693
1694 /* will be cleared on avail space */
1695 set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags);
1696}
1697
d9ca1de8
PA		 1698static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1699{
1700 struct mptcp_sock *msk = mptcp_sk(sk);
17091708 1701 struct page_frag *pfrag;
6d0060f6 1702 size_t copied = 0;
caf971df 1703 int ret = 0;
6d0060f6 1704 long timeo;
f870fa0b 1705
987858e5
PA		 1706 /* we don't support FASTOPEN yet */
1707 if (msg->msg_flags & MSG_FASTOPEN)
f870fa0b
MM		 1708 return -EOPNOTSUPP;
1709
987858e5
PA		 1710 /* silently ignore everything else */
1711 msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL;
1712
6511882c 1713 lock_sock(sk);
1954b860
MM		 1714
1715 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1716
1717 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
1718 ret = sk_stream_wait_connect(sk, &timeo);
1719 if (ret)
1720 goto out;
1721 }
1722
17091708 1723 pfrag = sk_page_frag(sk);
18b683bf 1724
d9ca1de8 1725 while (msg_data_left(msg)) {
724cfd2e 1726 int total_ts, frag_truesize = 0;
d9ca1de8 1727 struct mptcp_data_frag *dfrag;
d9ca1de8
PA		 1728 bool dfrag_collapsed;
1729 size_t psize, offset;
18b683bf 1730
d9ca1de8
PA		 1731 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) {
1732 ret = -EPIPE;
f296234c
PK		 1733 goto out;
1734 }
da51aef5 1735
d9ca1de8
PA		 1736 /* reuse tail pfrag, if possible, or carve a new one from the
1737 * page allocator
1738 */
1739 dfrag = mptcp_pending_tail(sk);
1740 dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
1741 if (!dfrag_collapsed) {
6e628cd3
PA		 1742 if (!sk_stream_memory_free(sk))
1743 goto wait_for_memory;
1744
d9ca1de8
PA		 1745 if (!mptcp_page_frag_refill(sk, pfrag))
1746 goto wait_for_memory;
1747
1748 dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
1749 frag_truesize = dfrag->overhead;
72511aab 1750 }
6d0060f6 1751
d9ca1de8
PA		 1752 /* we do not bound vs wspace, to allow a single packet.
1753 * memory accounting will prevent execessive memory usage
1754 * anyway
d5f49190 1755 */
d9ca1de8
PA		 1756 offset = dfrag->offset + dfrag->data_len;
1757 psize = pfrag->size - offset;
1758 psize = min_t(size_t, psize, msg_data_left(msg));
724cfd2e 1759 total_ts = psize + frag_truesize;
d9ca1de8 1760
6511882c 1761 if (!sk_wmem_schedule(sk, total_ts))
724cfd2e 1762 goto wait_for_memory;
724cfd2e 1763
d9ca1de8
PA		 1764 if (copy_page_from_iter(dfrag->page, offset, psize,
1765 &msg->msg_iter) != psize) {
1766 ret = -EFAULT;
1767 goto out;
72511aab
FW		 1768 }
1769
d9ca1de8 1770 /* data successfully copied into the write queue */
6511882c 1771 sk->sk_forward_alloc -= total_ts;
d9ca1de8
PA		 1772 copied += psize;
1773 dfrag->data_len += psize;
1774 frag_truesize += psize;
1775 pfrag->offset += frag_truesize;
1776 WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
1777
1778 /* charge data on mptcp pending queue to the msk socket
1779 * Note: we charge such data both to sk and ssk
fb529e62 1780 */
d9ca1de8 1781 sk_wmem_queued_add(sk, frag_truesize);
d9ca1de8
PA		 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);
fb529e62 1787 }
e4b61351 1788 pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk,
d9ca1de8
PA		 1789 dfrag->data_seq, dfrag->data_len, dfrag->already_sent,
1790 !dfrag_collapsed);
6d0060f6 1791
d9ca1de8 1792 continue;
b51f9b80 1793
d9ca1de8 1794wait_for_memory:
5cf92bba 1795 mptcp_set_nospace(sk);
c2e6048f 1796 __mptcp_push_pending(sk, msg->msg_flags);
d9ca1de8
PA		 1797 ret = sk_stream_wait_memory(sk, &timeo);
1798 if (ret)
1799 goto out;
57040755 1800 }
6d0060f6 1801
13e16037 1802 if (copied)
c2e6048f 1803 __mptcp_push_pending(sk, msg->msg_flags);
d9ca1de8 1804
1954b860 1805out:
cec37a6e 1806 release_sock(sk);
8555c6bf 1807 return copied ? : ret;
f870fa0b
MM		 1808}
1809
6771bfd9
FW		 1810static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk,
1811 struct msghdr *msg,
b7f653b2
FW		 1812 size_t len, int flags,
1813 struct scm_timestamping_internal *tss,
1814 int *cmsg_flags)
6771bfd9 1815{
ca4fb892 1816 struct sk_buff *skb, *tmp;
6771bfd9
FW		 1817 int copied = 0;
1818
ca4fb892 1819 skb_queue_walk_safe(&msk->receive_queue, skb, tmp) {
6771bfd9
FW		 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);
1823 int err;
1824
d976092c
PA		 1825 if (!(flags & MSG_TRUNC)) {
1826 err = skb_copy_datagram_msg(skb, offset, msg, count);
1827 if (unlikely(err < 0)) {
1828 if (!copied)
1829 return err;
1830 break;
1831 }
6771bfd9
FW		 1832 }
1833
b7f653b2
FW		 1834 if (MPTCP_SKB_CB(skb)->has_rxtstamp) {
1835 tcp_update_recv_tstamps(skb, tss);
1836 *cmsg_flags |= MPTCP_CMSG_TS;
1837 }
1838
6771bfd9
FW		 1839 copied += count;
1840
1841 if (count < data_len) {
2c9e7765 1842 if (!(flags & MSG_PEEK)) {
ca4fb892 1843 MPTCP_SKB_CB(skb)->offset += count;
2c9e7765
FW		 1844 MPTCP_SKB_CB(skb)->map_seq += count;
1845 }
6771bfd9
FW		 1846 break;
1847 }
1848
ca4fb892
YL		 1849 if (!(flags & MSG_PEEK)) {
1850 /* we will bulk release the skb memory later */
1851 skb->destructor = NULL;
ce599c51 1852 WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize);
ca4fb892
YL		 1853 __skb_unlink(skb, &msk->receive_queue);
1854 __kfree_skb(skb);
1855 }
6771bfd9
FW		 1856
1857 if (copied >= len)
1858 break;
1859 }
1860
1861 return copied;
1862}
1863
a6b118fe
FW		 1864/* receive buffer autotuning. See tcp_rcv_space_adjust for more information.
1865 *
1866 * Only difference: Use highest rtt estimate of the subflows in use.
1867 */
1868static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
1869{
1870 struct mptcp_subflow_context *subflow;
1871 struct sock *sk = (struct sock *)msk;
1872 u32 time, advmss = 1;
1873 u64 rtt_us, mstamp;
1874
1875 sock_owned_by_me(sk);
1876
1877 if (copied <= 0)
1878 return;
1879
1880 msk->rcvq_space.copied += copied;
1881
1882 mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC);
1883 time = tcp_stamp_us_delta(mstamp, msk->rcvq_space.time);
1884
1885 rtt_us = msk->rcvq_space.rtt_us;
1886 if (rtt_us && time < (rtt_us >> 3))
1887 return;
1888
1889 rtt_us = 0;
1890 mptcp_for_each_subflow(msk, subflow) {
1891 const struct tcp_sock *tp;
1892 u64 sf_rtt_us;
1893 u32 sf_advmss;
1894
1895 tp = tcp_sk(mptcp_subflow_tcp_sock(subflow));
1896
1897 sf_rtt_us = READ_ONCE(tp->rcv_rtt_est.rtt_us);
1898 sf_advmss = READ_ONCE(tp->advmss);
1899
1900 rtt_us = max(sf_rtt_us, rtt_us);
1901 advmss = max(sf_advmss, advmss);
1902 }
1903
1904 msk->rcvq_space.rtt_us = rtt_us;
1905 if (time < (rtt_us >> 3) || rtt_us == 0)
1906 return;
1907
1908 if (msk->rcvq_space.copied <= msk->rcvq_space.space)
1909 goto new_measure;
1910
78047648 1911 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) &&
a6b118fe
FW		 1912 !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
1913 int rcvmem, rcvbuf;
1914 u64 rcvwin, grow;
1915
1916 rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss;
1917
1918 grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space);
1919
1920 do_div(grow, msk->rcvq_space.space);
1921 rcvwin += (grow << 1);
1922
1923 rcvmem = SKB_TRUESIZE(advmss + MAX_TCP_HEADER);
1924 while (tcp_win_from_space(sk, rcvmem) < advmss)
1925 rcvmem += 128;
1926
1927 do_div(rcvwin, advmss);
1928 rcvbuf = min_t(u64, rcvwin * rcvmem,
1929 sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
1930
1931 if (rcvbuf > sk->sk_rcvbuf) {
1932 u32 window_clamp;
1933
1934 window_clamp = tcp_win_from_space(sk, rcvbuf);
1935 WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
1936
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).
1941 */
1942 mptcp_for_each_subflow(msk, subflow) {
1943 struct sock *ssk;
c76c6956 1944 bool slow;
a6b118fe
FW		 1945
1946 ssk = mptcp_subflow_tcp_sock(subflow);
c76c6956 1947 slow = lock_sock_fast(ssk);
a6b118fe
FW		 1948 WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf);
1949 tcp_sk(ssk)->window_clamp = window_clamp;
c76c6956
PA		 1950 tcp_cleanup_rbuf(ssk, 1);
1951 unlock_sock_fast(ssk, slow);
a6b118fe
FW		 1952 }
1953 }
1954 }
1955
1956 msk->rcvq_space.space = msk->rcvq_space.copied;
1957new_measure:
1958 msk->rcvq_space.copied = 0;
1959 msk->rcvq_space.time = mstamp;
1960}
1961
87952603
PA		 1962static void __mptcp_update_rmem(struct sock *sk)
1963{
1964 struct mptcp_sock *msk = mptcp_sk(sk);
1965
1966 if (!msk->rmem_released)
1967 return;
1968
1969 atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc);
6511882c 1970 mptcp_rmem_uncharge(sk, msk->rmem_released);
ce599c51 1971 WRITE_ONCE(msk->rmem_released, 0);
87952603
PA		 1972}
1973
1974static void __mptcp_splice_receive_queue(struct sock *sk)
1975{
1976 struct mptcp_sock *msk = mptcp_sk(sk);
1977
1978 skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue);
1979}
1980
e3859603 1981static bool __mptcp_move_skbs(struct mptcp_sock *msk)
6771bfd9 1982{
87952603 1983 struct sock *sk = (struct sock *)msk;
6771bfd9 1984 unsigned int moved = 0;
87952603 1985 bool ret, done;
d5f49190 1986
6771bfd9
FW		 1987 do {
1988 struct sock *ssk = mptcp_subflow_recv_lookup(msk);
65f49fe7 1989 bool slowpath;
6771bfd9 1990
87952603
PA		 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.
1994 */
1995 if (likely(!ssk))
6771bfd9
FW		 1996 break;
1997
65f49fe7 1998 slowpath = lock_sock_fast(ssk);
87952603 1999 mptcp_data_lock(sk);
e3859603 2000 __mptcp_update_rmem(sk);
6771bfd9 2001 done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
87952603 2002 mptcp_data_unlock(sk);
499ada50
PA		 2003
2004 if (unlikely(ssk->sk_err))
2005 __mptcp_error_report(sk);
65f49fe7 2006 unlock_sock_fast(ssk, slowpath);
6771bfd9
FW		 2007 } while (!done);
2008
87952603
PA		 2009 /* acquire the data lock only if some input data is pending */
2010 ret = moved > 0;
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);
ab174ad8 2018 }
87952603
PA		 2019 if (ret)
2020 mptcp_check_data_fin((struct sock *)msk);
2021 return !skb_queue_empty(&msk->receive_queue);
6771bfd9
FW		 2022}
2023
2c9e7765
FW		 2024static unsigned int mptcp_inq_hint(const struct sock *sk)
2025{
2026 const struct mptcp_sock *msk = mptcp_sk(sk);
2027 const struct sk_buff *skb;
2028
2029 skb = skb_peek(&msk->receive_queue);
2030 if (skb) {
2031 u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq;
2032
2033 if (hint_val >= INT_MAX)
2034 return INT_MAX;
2035
2036 return (unsigned int)hint_val;
2037 }
2038
2039 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
2040 return 1;
2041
2042 return 0;
2043}
2044
f870fa0b 2045static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
ec095263 2046 int flags, int *addr_len)
f870fa0b
MM		 2047{
2048 struct mptcp_sock *msk = mptcp_sk(sk);
b7f653b2
FW		 2049 struct scm_timestamping_internal tss;
2050 int copied = 0, cmsg_flags = 0;
7a6a6cbc
PA		 2051 int target;
2052 long timeo;
f870fa0b 2053
cb9d80f4
PA		 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);
2057
6511882c 2058 lock_sock(sk);
fd897679
PA		 2059 if (unlikely(sk->sk_state == TCP_LISTEN)) {
2060 copied = -ENOTCONN;
2061 goto out_err;
2062 }
2063
ec095263 2064 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
7a6a6cbc
PA		 2065
2066 len = min_t(size_t, len, INT_MAX);
2067 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2068
2c9e7765
FW		 2069 if (unlikely(msk->recvmsg_inq))
2070 cmsg_flags = MPTCP_CMSG_INQ;
2071
05e3ecea 2072 while (copied < len) {
e3859603 2073 int bytes_read;
7a6a6cbc 2074
b7f653b2 2075 bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags);
6771bfd9
FW		 2076 if (unlikely(bytes_read < 0)) {
2077 if (!copied)
2078 copied = bytes_read;
2079 goto out_err;
2080 }
7a6a6cbc 2081
6771bfd9 2082 copied += bytes_read;
7a6a6cbc 2083
ea4ca586 2084 /* be sure to advertise window change */
e3859603
PA		 2085 mptcp_cleanup_rbuf(msk);
2086
2087 if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk))
2088 continue;
ea4ca586 2089
7a6a6cbc
PA		 2090 /* only the master socket status is relevant here. The exit
2091 * conditions mirror closely tcp_recvmsg()
2092 */
2093 if (copied >= target)
2094 break;
2095
2096 if (copied) {
2097 if (sk->sk_err ||
2098 sk->sk_state == TCP_CLOSE ||
2099 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2100 !timeo ||
2101 signal_pending(current))
2102 break;
2103 } else {
2104 if (sk->sk_err) {
2105 copied = sock_error(sk);
2106 break;
2107 }
2108
5969856a
PA		 2109 if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
2110 mptcp_check_for_eof(msk);
2111
87952603
PA		 2112 if (sk->sk_shutdown & RCV_SHUTDOWN) {
2113 /* race breaker: the shutdown could be after the
2114 * previous receive queue check
2115 */
e3859603 2116 if (__mptcp_move_skbs(msk))
87952603 2117 continue;
7a6a6cbc 2118 break;
87952603 2119 }
7a6a6cbc
PA		 2120
2121 if (sk->sk_state == TCP_CLOSE) {
2122 copied = -ENOTCONN;
2123 break;
2124 }
2125
2126 if (!timeo) {
2127 copied = -EAGAIN;
2128 break;
2129 }
2130
2131 if (signal_pending(current)) {
2132 copied = sock_intr_errno(timeo);
2133 break;
2134 }
2135 }
2136
2137 pr_debug("block timeout %ld", timeo);
612f71d7 2138 sk_wait_data(sk, &timeo, NULL);
7a6a6cbc 2139 }
3c90e377 2140
6771bfd9 2141out_err:
b7f653b2
FW		 2142 if (cmsg_flags && copied >= 0) {
2143 if (cmsg_flags & MPTCP_CMSG_TS)
2144 tcp_recv_timestamp(msg, sk, &tss);
2c9e7765
FW		 2145
2146 if (cmsg_flags & MPTCP_CMSG_INQ) {
2147 unsigned int inq = mptcp_inq_hint(sk);
2148
2149 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);
2150 }
b7f653b2
FW		 2151 }
2152
612f71d7
PA		 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);
ca4fb892
YL		 2156 if (!(flags & MSG_PEEK))
2157 mptcp_rcv_space_adjust(msk, copied);
a6b118fe 2158
7a6a6cbc 2159 release_sock(sk);
cec37a6e
PK		 2160 return copied;
2161}
2162
b51f9b80
PA		 2163static void mptcp_retransmit_timer(struct timer_list *t)
2164{
2165 struct inet_connection_sock *icsk = from_timer(icsk, t,
2166 icsk_retransmit_timer);
2167 struct sock *sk = &icsk->icsk_inet.sk;
2d6f5a2b 2168 struct mptcp_sock *msk = mptcp_sk(sk);
b51f9b80
PA		 2169
2170 bh_lock_sock(sk);
2171 if (!sock_owned_by_user(sk)) {
2d6f5a2b
PA		 2172 /* we need a process context to retransmit */
2173 if (!test_and_set_bit(MPTCP_WORK_RTX, &msk->flags))
2174 mptcp_schedule_work(sk);
b51f9b80
PA		 2175 } else {
2176 /* delegate our work to tcp_release_cb() */
e9d09bac 2177 __set_bit(MPTCP_RETRANSMIT, &msk->cb_flags);
b51f9b80
PA		 2178 }
2179 bh_unlock_sock(sk);
2180 sock_put(sk);
2181}
2182
e16163b6
PA		 2183static void mptcp_timeout_timer(struct timer_list *t)
2184{
2185 struct sock *sk = from_timer(sk, t, sk_timer);
2186
2187 mptcp_schedule_work(sk);
b6d69fc8 2188 sock_put(sk);
e16163b6
PA		 2189}
2190
3b1d6210
PA		 2191/* Find an idle subflow. Return NULL if there is unacked data at tcp
2192 * level.
2193 *
2194 * A backup subflow is returned only if that is the only kind available.
2195 */
ff5a0b42 2196static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
3b1d6210 2197{
71b7dec2 2198 struct sock *backup = NULL, *pick = NULL;
3b1d6210 2199 struct mptcp_subflow_context *subflow;
71b7dec2 2200 int min_stale_count = INT_MAX;
3b1d6210
PA		 2201
2202 sock_owned_by_me((const struct sock *)msk);
2203
d5f49190 2204 if (__mptcp_check_fallback(msk))
d9ca1de8 2205 return NULL;
d5f49190 2206
3b1d6210
PA		 2207 mptcp_for_each_subflow(msk, subflow) {
2208 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2209
ff5a0b42 2210 if (!__mptcp_subflow_active(subflow))
d5f49190
PA		 2211 continue;
2212
71b7dec2
PA		 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);
2217 continue;
860975c6 2218 }
3b1d6210
PA		 2219
2220 if (subflow->backup) {
2221 if (!backup)
2222 backup = ssk;
2223 continue;
2224 }
2225
71b7dec2
PA		 2226 if (!pick)
2227 pick = ssk;
3b1d6210
PA		 2228 }
2229
71b7dec2
PA		 2230 if (pick)
2231 return pick;
2232
2233 /* use backup only if there are no progresses anywhere */
2234 return min_stale_count > 1 ? backup : NULL;
3b1d6210
PA		 2235}
2236
17aee05d
FW		 2237static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk)
2238{
2239 if (msk->subflow) {
2240 iput(SOCK_INODE(msk->subflow));
2241 msk->subflow = NULL;
2242 }
2243}
2244
1e1d9d6f
PA		 2245bool __mptcp_retransmit_pending_data(struct sock *sk)
2246{
2247 struct mptcp_data_frag *cur, *rtx_head;
2248 struct mptcp_sock *msk = mptcp_sk(sk);
2249
2250 if (__mptcp_check_fallback(mptcp_sk(sk)))
2251 return false;
2252
2253 if (tcp_rtx_and_write_queues_empty(sk))
2254 return false;
2255
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
2259 */
2260 mptcp_data_lock(sk);
2261 __mptcp_clean_una_wakeup(sk);
2262 rtx_head = mptcp_rtx_head(sk);
2263 if (!rtx_head) {
2264 mptcp_data_unlock(sk);
2265 return false;
2266 }
2267
0d199e43 2268 msk->recovery_snd_nxt = msk->snd_nxt;
1e1d9d6f
PA		 2269 msk->recovery = true;
2270 mptcp_data_unlock(sk);
2271
2272 msk->first_pending = rtx_head;
1e1d9d6f
PA		 2273 msk->snd_burst = 0;
2274
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)
2278 break;
2279 cur->already_sent = 0;
2280 }
2281
2282 return true;
2283}
2284
b29fcfb5
PA		 2285/* flags for __mptcp_close_ssk() */
2286#define MPTCP_CF_PUSH BIT(1)
2287#define MPTCP_CF_FASTCLOSE BIT(2)
2288
cec37a6e
PK		 2289/* subflow sockets can be either outgoing (connect) or incoming
2290 * (accept).
2291 *
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
2295 * parent socket.
2296 */
a141e02e 2297static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
b29fcfb5
PA		 2298 struct mptcp_subflow_context *subflow,
2299 unsigned int flags)
cec37a6e 2300{
e0be4931 2301 struct mptcp_sock *msk = mptcp_sk(sk);
b29fcfb5 2302 bool need_push, dispose_it;
e0be4931 2303
b29fcfb5
PA		 2304 dispose_it = !msk->subflow || ssk != msk->subflow->sk;
2305 if (dispose_it)
2306 list_del(&subflow->node);
cec37a6e 2307
3f8b2667 2308 lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
e16163b6 2309
b29fcfb5
PA		 2310 if (flags & MPTCP_CF_FASTCLOSE)
2311 subflow->send_fastclose = 1;
2312
2313 need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk);
2314 if (!dispose_it) {
2315 tcp_disconnect(ssk, 0);
2316 msk->subflow->state = SS_UNCONNECTED;
2317 mptcp_subflow_ctx_reset(subflow);
2318 release_sock(ssk);
2319
2320 goto out;
2321 }
2322
e16163b6
PA		 2323 /* if we are invoked by the msk cleanup code, the subflow is
2324 * already orphaned
2325 */
866f26f2 2326 if (ssk->sk_socket)
e16163b6 2327 sock_orphan(ssk);
e16163b6 2328
d7b1bfd0
PA		 2329 subflow->disposable = 1;
2330
e16163b6
PA		 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;
2334 */
2335 if (!inet_csk(ssk)->icsk_ulp_ops) {
2336 kfree_rcu(subflow, rcu);
cec37a6e 2337 } else {
d7b1bfd0 2338 /* otherwise tcp will dispose of the ssk and subflow ctx */
6aeed904
PA		 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);
2343 }
e16163b6
PA		 2344 __tcp_close(ssk, 0);
2345
2346 /* close acquired an extra ref */
2347 __sock_put(ssk);
cec37a6e 2348 }
e16163b6 2349 release_sock(ssk);
e16163b6
PA		 2350
2351 sock_put(ssk);
e0be4931 2352
c8fe62f0
FW		 2353 if (ssk == msk->first)
2354 msk->first = NULL;
2355
b29fcfb5
PA		 2356out:
2357 if (ssk == msk->last_snd)
2358 msk->last_snd = NULL;
1e1d9d6f
PA		 2359
2360 if (need_push)
2361 __mptcp_push_pending(sk, 0);
f870fa0b
MM		 2362}
2363
a141e02e
FW		 2364void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
2365 struct mptcp_subflow_context *subflow)
2366{
b911c97c
FW		 2367 if (sk->sk_state == TCP_ESTABLISHED)
2368 mptcp_event(MPTCP_EVENT_SUB_CLOSED, mptcp_sk(sk), ssk, GFP_KERNEL);
a88c9e49
PA		 2369
2370 /* subflow aborted before reaching the fully_established status
2371 * attempt the creation of the next subflow
2372 */
2373 mptcp_pm_subflow_check_next(mptcp_sk(sk), ssk, subflow);
2374
b29fcfb5 2375 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_PUSH);
a141e02e
FW		 2376}
2377
dc24f8b4
PA		 2378static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu)
2379{
2380 return 0;
2381}
2382
0e4f35d7
PA		 2383static void __mptcp_close_subflow(struct mptcp_sock *msk)
2384{
2385 struct mptcp_subflow_context *subflow, *tmp;
2386
3abc05d9
FW		 2387 might_sleep();
2388
0e4f35d7
PA		 2389 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
2390 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2391
2392 if (inet_sk_state_load(ssk) != TCP_CLOSE)
2393 continue;
2394
40947e13
FW		 2395 /* 'subflow_data_ready' will re-sched once rx queue is empty */
2396 if (!skb_queue_empty_lockless(&ssk->sk_receive_queue))
2397 continue;
2398
a141e02e 2399 mptcp_close_ssk((struct sock *)msk, ssk, subflow);
0e4f35d7
PA		 2400 }
2401}
2402
e16163b6
PA		 2403static bool mptcp_check_close_timeout(const struct sock *sk)
2404{
2405 s32 delta = tcp_jiffies32 - inet_csk(sk)->icsk_mtup.probe_timestamp;
2406 struct mptcp_subflow_context *subflow;
2407
2408 if (delta >= TCP_TIMEWAIT_LEN)
2409 return true;
2410
2411 /* if all subflows are in closed status don't bother with additional
2412 * timeout
2413 */
2414 mptcp_for_each_subflow(mptcp_sk(sk), subflow) {
2415 if (inet_sk_state_load(mptcp_subflow_tcp_sock(subflow)) !=
2416 TCP_CLOSE)
2417 return false;
2418 }
2419 return true;
2420}
2421
50c504a2
FW		 2422static void mptcp_check_fastclose(struct mptcp_sock *msk)
2423{
2424 struct mptcp_subflow_context *subflow, *tmp;
2425 struct sock *sk = &msk->sk.icsk_inet.sk;
2426
2427 if (likely(!READ_ONCE(msk->rcv_fastclose)))
2428 return;
2429
2430 mptcp_token_destroy(msk);
2431
2432 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
2433 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
75e908c3 2434 bool slow;
50c504a2 2435
75e908c3 2436 slow = lock_sock_fast(tcp_sk);
50c504a2
FW		 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);
2440 }
75e908c3 2441 unlock_sock_fast(tcp_sk, slow);
50c504a2
FW		 2442 }
2443
2444 inet_sk_state_store(sk, TCP_CLOSE);
2445 sk->sk_shutdown = SHUTDOWN_MASK;
2446 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
50c504a2
FW		 2447 set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags);
2448
2449 mptcp_close_wake_up(sk);
2450}
2451
2948d0a1 2452static void __mptcp_retrans(struct sock *sk)
80992017 2453{
2948d0a1 2454 struct mptcp_sock *msk = mptcp_sk(sk);
caf971df 2455 struct mptcp_sendmsg_info info = {};
3b1d6210 2456 struct mptcp_data_frag *dfrag;
3b1d6210 2457 size_t copied = 0;
2948d0a1
PA		 2458 struct sock *ssk;
2459 int ret;
3b1d6210 2460
b5941f06 2461 mptcp_clean_una_wakeup(sk);
3241a9c0
FW		 2462
2463 /* first check ssk: need to kick "stale" logic */
2464 ssk = mptcp_subflow_get_retrans(msk);
3b1d6210 2465 dfrag = mptcp_rtx_head(sk);
6477dd39
MM		 2466 if (!dfrag) {
2467 if (mptcp_data_fin_enabled(msk)) {
2468 struct inet_connection_sock *icsk = inet_csk(sk);
2469
2470 icsk->icsk_retransmits++;
2471 mptcp_set_datafin_timeout(sk);
2472 mptcp_send_ack(msk);
2473
2474 goto reset_timer;
2475 }
2476
3241a9c0
FW		 2477 if (!mptcp_send_head(sk))
2478 return;
2479
2480 goto reset_timer;
6477dd39 2481 }
3b1d6210 2482
3b1d6210 2483 if (!ssk)
2948d0a1 2484 goto reset_timer;
3b1d6210
PA		 2485
2486 lock_sock(ssk);
2487
d9ca1de8
PA		 2488 /* limit retransmission to the bytes already sent on some subflows */
2489 info.sent = 0;
4e14867d
PA		 2490 info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len : dfrag->already_sent;
2491 while (info.sent < info.limit) {
d9ca1de8 2492 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
6f8a612a 2493 if (ret <= 0)
3b1d6210
PA		 2494 break;
2495
fc518953 2496 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RETRANSSEGS);
3b1d6210 2497 copied += ret;
d9ca1de8 2498 info.sent += ret;
3b1d6210 2499 }
4e14867d
PA		 2500 if (copied) {
2501 dfrag->already_sent = max(dfrag->already_sent, info.sent);
caf971df
PA		 2502 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
2503 info.size_goal);
0530020a 2504 WRITE_ONCE(msk->allow_infinite_fallback, false);
4e14867d 2505 }
3b1d6210 2506
3b1d6210
PA		 2507 release_sock(ssk);
2508
2948d0a1 2509reset_timer:
3241a9c0
FW		 2510 mptcp_check_and_set_pending(sk);
2511
3b1d6210
PA		 2512 if (!mptcp_timer_pending(sk))
2513 mptcp_reset_timer(sk);
2948d0a1
PA		 2514}
2515
76a13b31
GT		 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
2518 */
2519void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout)
2520{
2521 struct sock *sk = (struct sock *)msk;
2522 unsigned long timeout, close_timeout;
2523
2524 if (!fail_tout && !sock_flag(sk, SOCK_DEAD))
2525 return;
2526
2527 close_timeout = inet_csk(sk)->icsk_mtup.probe_timestamp - tcp_jiffies32 + jiffies + TCP_TIMEWAIT_LEN;
2528
2529 /* the close timeout takes precedence on the fail one, and here at least one of
2530 * them is active
2531 */
2532 timeout = sock_flag(sk, SOCK_DEAD) ? close_timeout : fail_tout;
2533
2534 sk_reset_timer(sk, &sk->sk_timer, timeout);
2535}
2536
49fa1919
GT		 2537static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)
2538{
76a13b31 2539 struct sock *ssk = msk->first;
49fa1919
GT		 2540 bool slow;
2541
76a13b31
GT		 2542 if (!ssk)
2543 return;
49fa1919 2544
76a13b31
GT		 2545 pr_debug("MP_FAIL doesn't respond, reset the subflow");
2546
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);
2551
2552 mptcp_reset_timeout(msk, 0);
49fa1919
GT		 2553}
2554
2948d0a1
PA		 2555static void mptcp_worker(struct work_struct *work)
2556{
2557 struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
2558 struct sock *sk = &msk->sk.icsk_inet.sk;
76a13b31 2559 unsigned long fail_tout;
2948d0a1
PA		 2560 int state;
2561
2562 lock_sock(sk);
2563 state = sk->sk_state;
2564 if (unlikely(state == TCP_CLOSE))
2565 goto unlock;
2566
2567 mptcp_check_data_fin_ack(sk);
2948d0a1
PA		 2568
2569 mptcp_check_fastclose(msk);
2570
86e39e04 2571 mptcp_pm_nl_work(msk);
2948d0a1
PA		 2572
2573 if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
2574 mptcp_check_for_eof(msk);
2575
2576 __mptcp_check_send_data_fin(sk);
2577 mptcp_check_data_fin(sk);
2578
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
2582 */
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);
2587 goto unlock;
2588 }
2589
2590 if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags))
2591 __mptcp_close_subflow(msk);
2592
2593 if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags))
2594 __mptcp_retrans(sk);
3b1d6210 2595
76a13b31
GT		 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);
49fa1919 2599
3b1d6210 2600unlock:
80992017
PA		 2601 release_sock(sk);
2602 sock_put(sk);
2603}
2604
784325e9 2605static int __mptcp_init_sock(struct sock *sk)
f870fa0b 2606{
cec37a6e
PK		 2607 struct mptcp_sock *msk = mptcp_sk(sk);
2608
2609 INIT_LIST_HEAD(&msk->conn_list);
ec3edaa7 2610 INIT_LIST_HEAD(&msk->join_list);
18b683bf 2611 INIT_LIST_HEAD(&msk->rtx_queue);
80992017 2612 INIT_WORK(&msk->work, mptcp_worker);
87952603 2613 __skb_queue_head_init(&msk->receive_queue);
ab174ad8 2614 msk->out_of_order_queue = RB_ROOT;
f0e6a4cf 2615 msk->first_pending = NULL;
6511882c 2616 msk->rmem_fwd_alloc = 0;
ce599c51 2617 WRITE_ONCE(msk->rmem_released, 0);
33d41c9c 2618 msk->timer_ival = TCP_RTO_MIN;
cec37a6e 2619
8ab183de 2620 msk->first = NULL;
dc24f8b4 2621 inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
752e9067 2622 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
0530020a 2623 WRITE_ONCE(msk->allow_infinite_fallback, true);
1e1d9d6f 2624 msk->recovery = false;
8ab183de 2625
1b1c7a0e
PK		 2626 mptcp_pm_data_init(msk);
2627
b51f9b80
PA		 2628 /* re-use the csk retrans timer for MPTCP-level retrans */
2629 timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0);
e16163b6 2630 timer_setup(&sk->sk_timer, mptcp_timeout_timer, 0);
aa1fbd94 2631
f870fa0b
MM		 2632 return 0;
2633}
2634
b29fcfb5 2635static void mptcp_ca_reset(struct sock *sk)
784325e9 2636{
20b5759f 2637 struct inet_connection_sock *icsk = inet_csk(sk);
b29fcfb5
PA		 2638
2639 tcp_assign_congestion_control(sk);
2640 strcpy(mptcp_sk(sk)->ca_name, icsk->icsk_ca_ops->name);
2641
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;
2645}
2646
2647static int mptcp_init_sock(struct sock *sk)
2648{
fc518953
FW		 2649 struct net *net = sock_net(sk);
2650 int ret;
18b683bf 2651
b6c08380
GT		 2652 ret = __mptcp_init_sock(sk);
2653 if (ret)
2654 return ret;
2655
fc518953
FW		 2656 if (!mptcp_is_enabled(net))
2657 return -ENOPROTOOPT;
2658
2659 if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net))
2660 return -ENOMEM;
2661
fa68018d
PA		 2662 ret = __mptcp_socket_create(mptcp_sk(sk));
2663 if (ret)
2664 return ret;
2665
20b5759f
PA		 2666 /* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will
2667 * propagate the correct value
2668 */
b29fcfb5 2669 mptcp_ca_reset(sk);
20b5759f 2670
d027236c 2671 sk_sockets_allocated_inc(sk);
a6b118fe 2672 sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
da51aef5 2673 sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
d027236c 2674
18b683bf
PA		 2675 return 0;
2676}
2677
2678static void __mptcp_clear_xmit(struct sock *sk)
2679{
2680 struct mptcp_sock *msk = mptcp_sk(sk);
2681 struct mptcp_data_frag *dtmp, *dfrag;
2682
d9ca1de8 2683 WRITE_ONCE(msk->first_pending, NULL);
18b683bf 2684 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list)
d027236c 2685 dfrag_clear(sk, dfrag);
784325e9
MB		 2686}
2687
80992017
PA		 2688static void mptcp_cancel_work(struct sock *sk)
2689{
2690 struct mptcp_sock *msk = mptcp_sk(sk);
2691
b2771d24 2692 if (cancel_work_sync(&msk->work))
e16163b6 2693 __sock_put(sk);
80992017
PA		 2694}
2695
d0876b22 2696void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
21498490
PK		 2697{
2698 lock_sock(ssk);
2699
2700 switch (ssk->sk_state) {
2701 case TCP_LISTEN:
2702 if (!(how & RCV_SHUTDOWN))
2703 break;
df561f66 2704 fallthrough;
21498490
PK		 2705 case TCP_SYN_SENT:
2706 tcp_disconnect(ssk, O_NONBLOCK);
2707 break;
2708 default:
43b54c6e
MM		 2709 if (__mptcp_check_fallback(mptcp_sk(sk))) {
2710 pr_debug("Fallback");
2711 ssk->sk_shutdown |= how;
2712 tcp_shutdown(ssk, how);
2713 } else {
2714 pr_debug("Sending DATA_FIN on subflow %p", ssk);
43b54c6e 2715 tcp_send_ack(ssk);
6477dd39
MM		 2716 if (!mptcp_timer_pending(sk))
2717 mptcp_reset_timer(sk);
43b54c6e 2718 }
21498490
PK		 2719 break;
2720 }
2721
21498490
PK		 2722 release_sock(ssk);
2723}
2724
6920b851
MM		 2725static 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 ! */
2740};
2741
2742static int mptcp_close_state(struct sock *sk)
2743{
2744 int next = (int)new_state[sk->sk_state];
2745 int ns = next & TCP_STATE_MASK;
2746
2747 inet_sk_state_store(sk, ns);
2748
2749 return next & TCP_ACTION_FIN;
2750}
2751
e16163b6 2752static void __mptcp_check_send_data_fin(struct sock *sk)
f870fa0b 2753{
e16163b6 2754 struct mptcp_subflow_context *subflow;
f870fa0b
MM		 2755 struct mptcp_sock *msk = mptcp_sk(sk);
2756
e16163b6
PA		 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);
43b54c6e 2760
e16163b6
PA		 2761 /* we still need to enqueue subflows or not really shutting down,
2762 * skip this
2763 */
2764 if (!msk->snd_data_fin_enable || msk->snd_nxt + 1 != msk->write_seq ||
2765 mptcp_send_head(sk))
2766 return;
2767
2768 WRITE_ONCE(msk->snd_nxt, msk->write_seq);
2769
26aa2314
PA		 2770 /* fallback socket will not get data_fin/ack, can move to the next
2771 * state now
2772 */
2773 if (__mptcp_check_fallback(msk)) {
58cd405b 2774 WRITE_ONCE(msk->snd_una, msk->write_seq);
26aa2314
PA		 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);
2780 }
43b54c6e
MM		 2781 }
2782
e16163b6
PA		 2783 mptcp_for_each_subflow(msk, subflow) {
2784 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
43b54c6e 2785
e16163b6 2786 mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN);
43b54c6e 2787 }
e16163b6 2788}
2c22c06c 2789
e16163b6
PA		 2790static void __mptcp_wr_shutdown(struct sock *sk)
2791{
2792 struct mptcp_sock *msk = mptcp_sk(sk);
43b54c6e 2793
e16163b6
PA		 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));
2797
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);
2801
2802 __mptcp_check_send_data_fin(sk);
2803}
2804
2805static void __mptcp_destroy_sock(struct sock *sk)
2806{
2807 struct mptcp_subflow_context *subflow, *tmp;
2808 struct mptcp_sock *msk = mptcp_sk(sk);
2809 LIST_HEAD(conn_list);
2810
2811 pr_debug("msk=%p", msk);
f870fa0b 2812
3abc05d9
FW		 2813 might_sleep();
2814
3e501490 2815 /* join list will be eventually flushed (with rst) at sock lock release time*/
b2c5b614
FW		 2816 list_splice_init(&msk->conn_list, &conn_list);
2817
bcf3cf93 2818 mptcp_stop_timer(sk);
e16163b6
PA		 2819 sk_stop_timer(sk, &sk->sk_timer);
2820 msk->pm.status = 0;
b2c5b614 2821
b29fcfb5
PA		 2822 /* clears msk->subflow, allowing the following loop to close
2823 * even the initial subflow
2824 */
2825 mptcp_dispose_initial_subflow(msk);
b2c5b614 2826 list_for_each_entry_safe(subflow, tmp, &conn_list, node) {
cec37a6e 2827 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
b29fcfb5 2828 __mptcp_close_ssk(sk, ssk, subflow, 0);
f870fa0b
MM		 2829 }
2830
e16163b6 2831 sk->sk_prot->destroy(sk);
80992017 2832
6511882c 2833 WARN_ON_ONCE(msk->rmem_fwd_alloc);
87952603 2834 WARN_ON_ONCE(msk->rmem_released);
e16163b6
PA		 2835 sk_stream_kill_queues(sk);
2836 xfrm_sk_free_policy(sk);
aa1fbd94 2837
e16163b6
PA		 2838 sk_refcnt_debug_release(sk);
2839 sock_put(sk);
2840}
2841
2842static void mptcp_close(struct sock *sk, long timeout)
2843{
2844 struct mptcp_subflow_context *subflow;
76a13b31 2845 struct mptcp_sock *msk = mptcp_sk(sk);
e16163b6
PA		 2846 bool do_cancel_work = false;
2847
2848 lock_sock(sk);
2849 sk->sk_shutdown = SHUTDOWN_MASK;
2850
2851 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) {
2852 inet_sk_state_store(sk, TCP_CLOSE);
2853 goto cleanup;
2854 }
6771bfd9 2855
e16163b6
PA		 2856 if (mptcp_close_state(sk))
2857 __mptcp_wr_shutdown(sk);
2858
2859 sk_stream_wait_close(sk, timeout);
2860
2861cleanup:
2862 /* orphan all the subflows */
2863 inet_csk(sk)->icsk_mtup.probe_timestamp = tcp_jiffies32;
76a13b31 2864 mptcp_for_each_subflow(msk, subflow) {
e16163b6 2865 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
49054556 2866 bool slow = lock_sock_fast_nested(ssk);
e16163b6 2867
76a13b31
GT		 2868 /* since the close timeout takes precedence on the fail one,
2869 * cancel the latter
2870 */
2871 if (ssk == msk->first)
2872 subflow->fail_tout = 0;
2873
e16163b6
PA		 2874 sock_orphan(ssk);
2875 unlock_sock_fast(ssk, slow);
e16163b6
PA		 2876 }
2877 sock_orphan(sk);
2878
2879 sock_hold(sk);
2880 pr_debug("msk=%p state=%d", sk, sk->sk_state);
b29fcfb5 2881 if (mptcp_sk(sk)->token)
76a13b31 2882 mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);
b29fcfb5 2883
e16163b6
PA		 2884 if (sk->sk_state == TCP_CLOSE) {
2885 __mptcp_destroy_sock(sk);
2886 do_cancel_work = true;
2887 } else {
76a13b31 2888 mptcp_reset_timeout(msk, 0);
e16163b6
PA		 2889 }
2890 release_sock(sk);
2891 if (do_cancel_work)
2892 mptcp_cancel_work(sk);
b911c97c 2893
e16163b6 2894 sock_put(sk);
f870fa0b
MM		 2895}
2896
cf7da0d6
PK		 2897static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
2898{
2899#if IS_ENABLED(CONFIG_MPTCP_IPV6)
2900 const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
2901 struct ipv6_pinfo *msk6 = inet6_sk(msk);
2902
2903 msk->sk_v6_daddr = ssk->sk_v6_daddr;
2904 msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;
2905
2906 if (msk6 && ssk6) {
2907 msk6->saddr = ssk6->saddr;
2908 msk6->flow_label = ssk6->flow_label;
2909 }
2910#endif
2911
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;
2918}
2919
18b683bf
PA		 2920static int mptcp_disconnect(struct sock *sk, int flags)
2921{
5c835bb1 2922 struct mptcp_subflow_context *subflow, *tmp;
76e2a55d
PA		 2923 struct mptcp_sock *msk = mptcp_sk(sk);
2924
b29fcfb5
PA		 2925 inet_sk_state_store(sk, TCP_CLOSE);
2926
5c835bb1 2927 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
13a9499e
PA		 2928 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2929
b29fcfb5 2930 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_FASTCLOSE);
13a9499e 2931 }
b29fcfb5 2932
bcf3cf93 2933 mptcp_stop_timer(sk);
b29fcfb5
PA		 2934 sk_stop_timer(sk, &sk->sk_timer);
2935
2936 if (mptcp_sk(sk)->token)
2937 mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL);
2938
2939 mptcp_destroy_common(msk);
2940 msk->last_snd = NULL;
e9d09bac
PA		 2941 WRITE_ONCE(msk->flags, 0);
2942 msk->cb_flags = 0;
2943 msk->push_pending = 0;
b29fcfb5
PA		 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);
2953 mptcp_ca_reset(sk);
2954
2955 sk->sk_shutdown = 0;
2956 sk_error_report(sk);
42c556fe 2957 return 0;
18b683bf
PA		 2958}
2959
b0519de8
FW		 2960#if IS_ENABLED(CONFIG_MPTCP_IPV6)
2961static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
2962{
2963 unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);
2964
2965 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
2966}
2967#endif
2968
fca5c82c 2969struct sock *mptcp_sk_clone(const struct sock *sk,
cfde141e 2970 const struct mptcp_options_received *mp_opt,
fca5c82c 2971 struct request_sock *req)
b0519de8 2972{
58b09919 2973 struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
b0519de8 2974 struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC);
58b09919
PA		 2975 struct mptcp_sock *msk;
2976 u64 ack_seq;
b0519de8
FW		 2977
2978 if (!nsk)
2979 return NULL;
2980
2981#if IS_ENABLED(CONFIG_MPTCP_IPV6)
2982 if (nsk->sk_family == AF_INET6)
2983 inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk);
2984#endif
2985
58b09919
PA		 2986 __mptcp_init_sock(nsk);
2987
2988 msk = mptcp_sk(nsk);
2989 msk->local_key = subflow_req->local_key;
2990 msk->token = subflow_req->token;
2991 msk->subflow = NULL;
b93df08c 2992 WRITE_ONCE(msk->fully_established, false);
74c7dfbe 2993 if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD)
06251181 2994 WRITE_ONCE(msk->csum_enabled, true);
58b09919 2995
58b09919 2996 msk->write_seq = subflow_req->idsn + 1;
eaa2ffab 2997 msk->snd_nxt = msk->write_seq;
7439d687
PA		 2998 msk->snd_una = msk->write_seq;
2999 msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
df00b087 3000 msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
6f8a612a 3001
74c7dfbe 3002 if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) {
58b09919 3003 msk->can_ack = true;
cfde141e 3004 msk->remote_key = mp_opt->sndr_key;
58b09919
PA		 3005 mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq);
3006 ack_seq++;
917944da 3007 WRITE_ONCE(msk->ack_seq, ack_seq);
f3589be0 3008 atomic64_set(&msk->rcv_wnd_sent, ack_seq);
58b09919 3009 }
7f20d5fc 3010
5e20087d 3011 sock_reset_flag(nsk, SOCK_RCU_FREE);
7f20d5fc
PA		 3012 /* will be fully established after successful MPC subflow creation */
3013 inet_sk_state_store(nsk, TCP_SYN_RECV);
0c148460
PA		 3014
3015 security_inet_csk_clone(nsk, req);
58b09919
PA		 3016 bh_unlock_sock(nsk);
3017
3018 /* keep a single reference */
3019 __sock_put(nsk);
b0519de8
FW		 3020 return nsk;
3021}
3022
a6b118fe
FW		 3023void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk)
3024{
3025 const struct tcp_sock *tp = tcp_sk(ssk);
3026
3027 msk->rcvq_space.copied = 0;
3028 msk->rcvq_space.rtt_us = 0;
3029
3030 msk->rcvq_space.time = tp->tcp_mstamp;
3031
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;
6f8a612a 3037
7439d687 3038 WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);
a6b118fe
FW		 3039}
3040
cf7da0d6
PK		 3041static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
3042 bool kern)
3043{
3044 struct mptcp_sock *msk = mptcp_sk(sk);
3045 struct socket *listener;
3046 struct sock *newsk;
3047
3048 listener = __mptcp_nmpc_socket(msk);
3049 if (WARN_ON_ONCE(!listener)) {
3050 *err = -EINVAL;
3051 return NULL;
3052 }
3053
3054 pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));
3055 newsk = inet_csk_accept(listener->sk, flags, err, kern);
3056 if (!newsk)
3057 return NULL;
3058
3059 pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk));
cf7da0d6
PK		 3060 if (sk_is_mptcp(newsk)) {
3061 struct mptcp_subflow_context *subflow;
3062 struct sock *new_mptcp_sock;
cf7da0d6
PK		 3063
3064 subflow = mptcp_subflow_ctx(newsk);
58b09919 3065 new_mptcp_sock = subflow->conn;
cf7da0d6 3066
58b09919
PA		 3067 /* is_mptcp should be false if subflow->conn is missing, see
3068 * subflow_syn_recv_sock()
3069 */
3070 if (WARN_ON_ONCE(!new_mptcp_sock)) {
3071 tcp_sk(newsk)->is_mptcp = 0;
d6692b3b 3072 goto out;
cf7da0d6
PK		 3073 }
3074
58b09919
PA		 3075 /* acquire the 2nd reference for the owning socket */
3076 sock_hold(new_mptcp_sock);
cf7da0d6 3077 newsk = new_mptcp_sock;
0397c6d8 3078 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
fc518953
FW		 3079 } else {
3080 MPTCP_INC_STATS(sock_net(sk),
3081 MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
cf7da0d6
PK		 3082 }
3083
d6692b3b
FW		 3084out:
3085 newsk->sk_kern_sock = kern;
cf7da0d6
PK		 3086 return newsk;
3087}
3088
5c8c1640
GT		 3089void mptcp_destroy_common(struct mptcp_sock *msk)
3090{
87952603
PA		 3091 struct sock *sk = (struct sock *)msk;
3092
6e628cd3
PA		 3093 __mptcp_clear_xmit(sk);
3094
87952603 3095 /* move to sk_receive_queue, sk_stream_kill_queues will purge it */
b29fcfb5 3096 mptcp_data_lock(sk);
87952603 3097 skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue);
6511882c 3098 __skb_queue_purge(&sk->sk_receive_queue);
5c8c1640 3099 skb_rbtree_purge(&msk->out_of_order_queue);
b29fcfb5 3100 mptcp_data_unlock(sk);
6511882c
PA		 3101
3102 /* move all the rx fwd alloc into the sk_mem_reclaim_final in
3103 * inet_sock_destruct() will dispose it
3104 */
3105 sk->sk_forward_alloc += msk->rmem_fwd_alloc;
3106 msk->rmem_fwd_alloc = 0;
5c8c1640
GT		 3107 mptcp_token_destroy(msk);
3108 mptcp_pm_free_anno_list(msk);
4638de5a 3109 mptcp_free_local_addr_list(msk);
5c8c1640
GT		 3110}
3111
79c0949e
PK		 3112static void mptcp_destroy(struct sock *sk)
3113{
c9fd9c5f
FW		 3114 struct mptcp_sock *msk = mptcp_sk(sk);
3115
5c8c1640 3116 mptcp_destroy_common(msk);
d027236c 3117 sk_sockets_allocated_dec(sk);
79c0949e
PK		 3118}
3119
6e628cd3
PA		 3120void __mptcp_data_acked(struct sock *sk)
3121{
3122 if (!sock_owned_by_user(sk))
3123 __mptcp_clean_una(sk);
3124 else
e9d09bac 3125 __set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags);
6e628cd3
PA		 3126
3127 if (mptcp_pending_data_fin_ack(sk))
3128 mptcp_schedule_work(sk);
3129}
3130
219d0499 3131void __mptcp_check_push(struct sock *sk, struct sock *ssk)
6e628cd3
PA		 3132{
3133 if (!mptcp_send_head(sk))
3134 return;
3135
40dc9416 3136 if (!sock_owned_by_user(sk)) {
b19bc294
PA		 3137 struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk));
3138
3139 if (xmit_ssk == ssk)
40dc9416 3140 __mptcp_subflow_push_pending(sk, ssk);
b19bc294 3141 else if (xmit_ssk)
bcd97734 3142 mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), MPTCP_DELEGATE_SEND);
40dc9416 3143 } else {
e9d09bac 3144 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags);
40dc9416 3145 }
6e628cd3
PA		 3146}
3147
e9d09bac
PA		 3148#define MPTCP_FLAGS_PROCESS_CTX_NEED (BIT(MPTCP_PUSH_PENDING) | \
3149 BIT(MPTCP_RETRANSMIT) | \
3150 BIT(MPTCP_FLUSH_JOIN_LIST))
3151
e93da928 3152/* processes deferred events and flush wmem */
14c441b5 3153static void mptcp_release_cb(struct sock *sk)
e9d09bac 3154 __must_hold(&sk->sk_lock.slock)
14c441b5 3155{
e9d09bac
PA		 3156 struct mptcp_sock *msk = mptcp_sk(sk);
3157
c2e6048f 3158 for (;;) {
e9d09bac
PA		 3159 unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) |
3160 msk->push_pending;
c2e6048f
PA		 3161 if (!flags)
3162 break;
3163
3164 /* the following actions acquire the subflow socket lock
6e628cd3
PA		 3165 *
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
3170 */
e9d09bac
PA		 3171 msk->push_pending = 0;
3172 msk->cb_flags &= ~flags;
6e628cd3 3173 spin_unlock_bh(&sk->sk_lock.slock);
3e501490
PA		 3174 if (flags & BIT(MPTCP_FLUSH_JOIN_LIST))
3175 __mptcp_flush_join_list(sk);
2e5de7e0 3176 if (flags & BIT(MPTCP_PUSH_PENDING))
c2e6048f 3177 __mptcp_push_pending(sk, 0);
2d6f5a2b
PA		 3178 if (flags & BIT(MPTCP_RETRANSMIT))
3179 __mptcp_retrans(sk);
c2e6048f
PA		 3180
3181 cond_resched();
6e628cd3
PA		 3182 spin_lock_bh(&sk->sk_lock.slock);
3183 }
c2e6048f 3184
e9d09bac 3185 if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags))
417789df 3186 __mptcp_clean_una_wakeup(sk);
65a569b0
PA		 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
3190 */
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);
43f5b111
PA		 3195 if (__test_and_clear_bit(MPTCP_RESET_SCHEDULER, &msk->cb_flags))
3196 msk->last_snd = NULL;
65a569b0 3197 }
6e628cd3 3198
87952603 3199 __mptcp_update_rmem(sk);
14c441b5
PA		 3200}
3201
bcd97734
PA		 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
3205 */
3206static void schedule_3rdack_retransmission(struct sock *ssk)
3207{
3208 struct inet_connection_sock *icsk = inet_csk(ssk);
3209 struct tcp_sock *tp = tcp_sk(ssk);
3210 unsigned long timeout;
3211
3212 if (mptcp_subflow_ctx(ssk)->fully_established)
3213 return;
3214
3215 /* reschedule with a timeout above RTT, as we must look only for drop */
3216 if (tp->srtt_us)
3217 timeout = usecs_to_jiffies(tp->srtt_us >> (3 - 1));
3218 else
3219 timeout = TCP_TIMEOUT_INIT;
3220 timeout += jiffies;
3221
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);
3226}
3227
b19bc294
PA		 3228void mptcp_subflow_process_delegated(struct sock *ssk)
3229{
3230 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
3231 struct sock *sk = subflow->conn;
3232
bcd97734
PA		 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);
3237 else
e9d09bac 3238 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags);
bcd97734
PA		 3239 mptcp_data_unlock(sk);
3240 mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_SEND);
3241 }
3242 if (test_bit(MPTCP_DELEGATE_ACK, &subflow->delegated_status)) {
3243 schedule_3rdack_retransmission(ssk);
3244 mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_ACK);
3245 }
b19bc294
PA		 3246}
3247
2c5ebd00
PA		 3248static int mptcp_hash(struct sock *sk)
3249{
3250 /* should never be called,
3251 * we hash the TCP subflows not the master socket
3252 */
3253 WARN_ON_ONCE(1);
3254 return 0;
3255}
3256
3257static void mptcp_unhash(struct sock *sk)
3258{
3259 /* called from sk_common_release(), but nothing to do here */
3260}
3261
cec37a6e 3262static int mptcp_get_port(struct sock *sk, unsigned short snum)
f870fa0b
MM		 3263{
3264 struct mptcp_sock *msk = mptcp_sk(sk);
cec37a6e 3265 struct socket *ssock;
f870fa0b 3266
cec37a6e
PK		 3267 ssock = __mptcp_nmpc_socket(msk);
3268 pr_debug("msk=%p, subflow=%p", msk, ssock);
3269 if (WARN_ON_ONCE(!ssock))
3270 return -EINVAL;
f870fa0b 3271
cec37a6e
PK		 3272 return inet_csk_get_port(ssock->sk, snum);
3273}
f870fa0b 3274
cec37a6e
PK		 3275void mptcp_finish_connect(struct sock *ssk)
3276{
3277 struct mptcp_subflow_context *subflow;
3278 struct mptcp_sock *msk;
3279 struct sock *sk;
6d0060f6 3280 u64 ack_seq;
f870fa0b 3281
cec37a6e 3282 subflow = mptcp_subflow_ctx(ssk);
cec37a6e
PK		 3283 sk = subflow->conn;
3284 msk = mptcp_sk(sk);
3285
648ef4b8
MM		 3286 pr_debug("msk=%p, token=%u", sk, subflow->token);
3287
6d0060f6
MM		 3288 mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq);
3289 ack_seq++;
648ef4b8
MM		 3290 subflow->map_seq = ack_seq;
3291 subflow->map_subflow_seq = 1;
6d0060f6 3292
cec37a6e
PK		 3293 /* the socket is not connected yet, no msk/subflow ops can access/race
3294 * accessing the field below
3295 */
3296 WRITE_ONCE(msk->remote_key, subflow->remote_key);
3297 WRITE_ONCE(msk->local_key, subflow->local_key);
6d0060f6 3298 WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
eaa2ffab 3299 WRITE_ONCE(msk->snd_nxt, msk->write_seq);
6d0060f6 3300 WRITE_ONCE(msk->ack_seq, ack_seq);
d22f4988 3301 WRITE_ONCE(msk->can_ack, 1);
7439d687 3302 WRITE_ONCE(msk->snd_una, msk->write_seq);
f3589be0 3303 atomic64_set(&msk->rcv_wnd_sent, ack_seq);
1b1c7a0e 3304
6c714f1b 3305 mptcp_pm_new_connection(msk, ssk, 0);
a6b118fe
FW		 3306
3307 mptcp_rcv_space_init(msk, ssk);
f870fa0b
MM		 3308}
3309
866f26f2 3310void mptcp_sock_graft(struct sock *sk, struct socket *parent)
cf7da0d6
PK		 3311{
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);
3317}
3318
e16163b6 3319bool mptcp_finish_join(struct sock *ssk)
f296234c 3320{
e16163b6 3321 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
f296234c
PK		 3322 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
3323 struct sock *parent = (void *)msk;
3e501490 3324 bool ret = true;
f296234c
PK		 3325
3326 pr_debug("msk=%p, subflow=%p", msk, subflow);
3327
3328 /* mptcp socket already closing? */
dc87efdb
FW		 3329 if (!mptcp_is_fully_established(parent)) {
3330 subflow->reset_reason = MPTCP_RST_EMPTCP;
f296234c 3331 return false;
dc87efdb 3332 }
f296234c 3333
70c708e8 3334 if (!list_empty(&subflow->node))
b911c97c 3335 goto out;
f296234c 3336
3e501490
PA		 3337 if (!mptcp_pm_allow_new_subflow(msk))
3338 goto err_prohibited;
10f6d46c 3339
3e501490
PA		 3340 /* active connections are already on conn_list.
3341 * If we can't acquire msk socket lock here, let the release callback
3342 * handle it
10f6d46c 3343 */
3e501490
PA		 3344 mptcp_data_lock(parent);
3345 if (!sock_owned_by_user(parent)) {
3346 ret = __mptcp_finish_join(msk, ssk);
3347 if (ret) {
3348 sock_hold(ssk);
3349 list_add_tail(&subflow->node, &msk->conn_list);
3350 }
3351 } else {
e16163b6 3352 sock_hold(ssk);
3e501490 3353 list_add_tail(&subflow->node, &msk->join_list);
e9d09bac 3354 __set_bit(MPTCP_FLUSH_JOIN_LIST, &msk->cb_flags);
e16163b6 3355 }
3e501490
PA		 3356 mptcp_data_unlock(parent);
3357
dc87efdb 3358 if (!ret) {
3e501490 3359err_prohibited:
dc87efdb 3360 subflow->reset_reason = MPTCP_RST_EPROHIBIT;
10f6d46c 3361 return false;
dc87efdb 3362 }
10f6d46c 3363
917944da 3364 subflow->map_seq = READ_ONCE(msk->ack_seq);
0530020a 3365 WRITE_ONCE(msk->allow_infinite_fallback, false);
3e501490 3366
b911c97c
FW		 3367out:
3368 mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
10f6d46c 3369 return true;
f296234c
PK		 3370}
3371
76e2a55d
PA		 3372static void mptcp_shutdown(struct sock *sk, int how)
3373{
3374 pr_debug("sk=%p, how=%d", sk, how);
3375
3376 if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk))
3377 __mptcp_wr_shutdown(sk);
3378}
3379
6511882c
PA		 3380static int mptcp_forward_alloc_get(const struct sock *sk)
3381{
3382 return sk->sk_forward_alloc + mptcp_sk(sk)->rmem_fwd_alloc;
3383}
3384
644807e3
FW		 3385static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v)
3386{
3387 const struct sock *sk = (void *)msk;
3388 u64 delta;
3389
3390 if (sk->sk_state == TCP_LISTEN)
3391 return -EINVAL;
3392
3393 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
3394 return 0;
3395
3396 delta = msk->write_seq - v;
07c2c7a3
PA		 3397 if (__mptcp_check_fallback(msk) && msk->first) {
3398 struct tcp_sock *tp = tcp_sk(msk->first);
3399
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.
3403 */
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;
3407 }
644807e3
FW		 3408 if (delta > INT_MAX)
3409 delta = INT_MAX;
3410
3411 return (int)delta;
3412}
3413
3414static int mptcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
3415{
3416 struct mptcp_sock *msk = mptcp_sk(sk);
3417 bool slow;
3418 int answ;
3419
3420 switch (cmd) {
3421 case SIOCINQ:
3422 if (sk->sk_state == TCP_LISTEN)
3423 return -EINVAL;
3424
3425 lock_sock(sk);
3426 __mptcp_move_skbs(msk);
3427 answ = mptcp_inq_hint(sk);
3428 release_sock(sk);
3429 break;
3430 case SIOCOUTQ:
3431 slow = lock_sock_fast(sk);
3432 answ = mptcp_ioctl_outq(msk, READ_ONCE(msk->snd_una));
3433 unlock_sock_fast(sk, slow);
3434 break;
3435 case SIOCOUTQNSD:
3436 slow = lock_sock_fast(sk);
3437 answ = mptcp_ioctl_outq(msk, msk->snd_nxt);
3438 unlock_sock_fast(sk, slow);
3439 break;
3440 default:
3441 return -ENOIOCTLCMD;
3442 }
3443
3444 return put_user(answ, (int __user *)arg);
3445}
3446
f870fa0b
MM		 3447static struct proto mptcp_prot = {
3448 .name = "MPTCP",
3449 .owner = THIS_MODULE,
3450 .init = mptcp_init_sock,
18b683bf 3451 .disconnect = mptcp_disconnect,
f870fa0b 3452 .close = mptcp_close,
cf7da0d6 3453 .accept = mptcp_accept,
717e79c8
PK		 3454 .setsockopt = mptcp_setsockopt,
3455 .getsockopt = mptcp_getsockopt,
76e2a55d 3456 .shutdown = mptcp_shutdown,
79c0949e 3457 .destroy = mptcp_destroy,
f870fa0b 3458 .sendmsg = mptcp_sendmsg,
644807e3 3459 .ioctl = mptcp_ioctl,
f870fa0b 3460 .recvmsg = mptcp_recvmsg,
14c441b5 3461 .release_cb = mptcp_release_cb,
2c5ebd00
PA		 3462 .hash = mptcp_hash,
3463 .unhash = mptcp_unhash,
cec37a6e 3464 .get_port = mptcp_get_port,
6511882c 3465 .forward_alloc_get = mptcp_forward_alloc_get,
d027236c
PA		 3466 .sockets_allocated = &mptcp_sockets_allocated,
3467 .memory_allocated = &tcp_memory_allocated,
3468 .memory_pressure = &tcp_memory_pressure,
d027236c 3469 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
989ef49b 3470 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
d027236c 3471 .sysctl_mem = sysctl_tcp_mem,
f870fa0b 3472 .obj_size = sizeof(struct mptcp_sock),
2c5ebd00 3473 .slab_flags = SLAB_TYPESAFE_BY_RCU,
f870fa0b
MM		 3474 .no_autobind = true,
3475};
3476
2303f994
PK		 3477static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3478{
3479 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3480 struct socket *ssock;
cf7da0d6 3481 int err;
2303f994
PK		 3482
3483 lock_sock(sock->sk);
fa68018d
PA		 3484 ssock = __mptcp_nmpc_socket(msk);
3485 if (!ssock) {
3486 err = -EINVAL;
2303f994
PK		 3487 goto unlock;
3488 }
3489
3490 err = ssock->ops->bind(ssock, uaddr, addr_len);
cf7da0d6
PK		 3491 if (!err)
3492 mptcp_copy_inaddrs(sock->sk, ssock->sk);
2303f994
PK		 3493
3494unlock:
3495 release_sock(sock->sk);
3496 return err;
3497}
3498
0235d075
PA		 3499static void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
3500 struct mptcp_subflow_context *subflow)
3501{
3502 subflow->request_mptcp = 0;
3503 __mptcp_do_fallback(msk);
3504}
3505
2303f994
PK		 3506static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
3507 int addr_len, int flags)
3508{
3509 struct mptcp_sock *msk = mptcp_sk(sock->sk);
2c5ebd00 3510 struct mptcp_subflow_context *subflow;
2303f994 3511 struct socket *ssock;
3d1d6d66 3512 int err = -EINVAL;
2303f994
PK		 3513
3514 lock_sock(sock->sk);
3d1d6d66
PA		 3515 if (uaddr) {
3516 if (addr_len < sizeof(uaddr->sa_family))
3517 goto unlock;
3518
3519 if (uaddr->sa_family == AF_UNSPEC) {
3520 err = mptcp_disconnect(sock->sk, flags);
3521 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
3522 goto unlock;
3523 }
3524 }
3525
41be81a8
PA		 3526 if (sock->state != SS_UNCONNECTED && msk->subflow) {
3527 /* pending connection or invalid state, let existing subflow
3528 * cope with that
3529 */
3530 ssock = msk->subflow;
3531 goto do_connect;
3532 }
3533
fa68018d 3534 ssock = __mptcp_nmpc_socket(msk);
3d1d6d66 3535 if (!ssock)
2303f994 3536 goto unlock;
2303f994 3537
fa68018d
PA		 3538 mptcp_token_destroy(msk);
3539 inet_sk_state_store(sock->sk, TCP_SYN_SENT);
2c5ebd00 3540 subflow = mptcp_subflow_ctx(ssock->sk);
cf7da0d6
PK		 3541#ifdef CONFIG_TCP_MD5SIG
3542 /* no MPTCP if MD5SIG is enabled on this socket or we may run out of
3543 * TCP option space.
3544 */
3545 if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
0235d075 3546 mptcp_subflow_early_fallback(msk, subflow);
cf7da0d6 3547#endif
a16195e3
PA		 3548 if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) {
3549 MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT);
0235d075 3550 mptcp_subflow_early_fallback(msk, subflow);
a16195e3 3551 }
5695eb88
PA		 3552 if (likely(!__mptcp_check_fallback(msk)))
3553 MPTCP_INC_STATS(sock_net(sock->sk), MPTCP_MIB_MPCAPABLEACTIVE);
cf7da0d6 3554
41be81a8 3555do_connect:
2303f994 3556 err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
41be81a8
PA		 3557 sock->state = ssock->state;
3558
3559 /* on successful connect, the msk state will be moved to established by
3560 * subflow_finish_connect()
3561 */
367fe04e 3562 if (!err || err == -EINPROGRESS)
41be81a8
PA		 3563 mptcp_copy_inaddrs(sock->sk, ssock->sk);
3564 else
3565 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
2303f994
PK		 3566
3567unlock:
3568 release_sock(sock->sk);
3569 return err;
3570}
3571
cf7da0d6
PK		 3572static int mptcp_listen(struct socket *sock, int backlog)
3573{
3574 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3575 struct socket *ssock;
3576 int err;
3577
3578 pr_debug("msk=%p", msk);
3579
3580 lock_sock(sock->sk);
fa68018d
PA		 3581 ssock = __mptcp_nmpc_socket(msk);
3582 if (!ssock) {
3583 err = -EINVAL;
cf7da0d6
PK		 3584 goto unlock;
3585 }
3586
fa68018d
PA		 3587 mptcp_token_destroy(msk);
3588 inet_sk_state_store(sock->sk, TCP_LISTEN);
5e20087d
FW		 3589 sock_set_flag(sock->sk, SOCK_RCU_FREE);
3590
cf7da0d6
PK		 3591 err = ssock->ops->listen(ssock, backlog);
3592 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
3593 if (!err)
3594 mptcp_copy_inaddrs(sock->sk, ssock->sk);
3595
3596unlock:
3597 release_sock(sock->sk);
3598 return err;
3599}
3600
cf7da0d6
PK		 3601static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
3602 int flags, bool kern)
3603{
3604 struct mptcp_sock *msk = mptcp_sk(sock->sk);
3605 struct socket *ssock;
3606 int err;
3607
3608 pr_debug("msk=%p", msk);
3609
cf7da0d6
PK		 3610 ssock = __mptcp_nmpc_socket(msk);
3611 if (!ssock)
71ba088c 3612 return -EINVAL;
cf7da0d6
PK		 3613
3614 err = ssock->ops->accept(sock, newsock, flags, kern);
d2f77c53 3615 if (err == 0 && !mptcp_is_tcpsk(newsock->sk)) {
cf7da0d6
PK		 3616 struct mptcp_sock *msk = mptcp_sk(newsock->sk);
3617 struct mptcp_subflow_context *subflow;
0397c6d8 3618 struct sock *newsk = newsock->sk;
0397c6d8 3619
4d54cc32 3620 lock_sock(newsk);
5b950ff4
PA		 3621
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.
c8fe62f0
FW		 3625 *
3626 * Even if remote has reset the initial subflow by now
3627 * the refcnt is still at least one.
5b950ff4
PA		 3628 */
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))
6c714f1b 3633 mptcp_pm_fully_established(msk, msk->first, GFP_KERNEL);
5b950ff4 3634
0397c6d8
PA		 3635 mptcp_copy_inaddrs(newsk, msk->first);
3636 mptcp_rcv_space_init(msk, msk->first);
5cf92bba 3637 mptcp_propagate_sndbuf(newsk, msk->first);
cf7da0d6
PK		 3638
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.
3641 */
190f8b06 3642 mptcp_for_each_subflow(msk, subflow) {
cf7da0d6
PK		 3643 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
3644
3645 if (!ssk->sk_socket)
3646 mptcp_sock_graft(ssk, newsock);
3647 }
4d54cc32 3648 release_sock(newsk);
cf7da0d6
PK		 3649 }
3650
cf7da0d6 3651 return err;
cf7da0d6
PK		 3652}
3653
8a05661b
PA		 3654static __poll_t mptcp_check_readable(struct mptcp_sock *msk)
3655{
612f71d7
PA		 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.
3658 */
3659 if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) &&
3660 skb_queue_empty_lockless(&msk->receive_queue))
3661 return 0;
3662
3663 return EPOLLIN | EPOLLRDNORM;
8a05661b
PA		 3664}
3665
8edf0864
FW		 3666static __poll_t mptcp_check_writeable(struct mptcp_sock *msk)
3667{
3668 struct sock *sk = (struct sock *)msk;
8edf0864
FW		 3669
3670 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
dd913410 3671 return EPOLLOUT | EPOLLWRNORM;
8edf0864
FW		 3672
3673 if (sk_stream_is_writeable(sk))
3674 return EPOLLOUT | EPOLLWRNORM;
3675
5cf92bba 3676 mptcp_set_nospace(sk);
6e628cd3
PA		 3677 smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */
3678 if (sk_stream_is_writeable(sk))
3679 return EPOLLOUT | EPOLLWRNORM;
8edf0864 3680
6e628cd3 3681 return 0;
8edf0864
FW		 3682}
3683
2303f994
PK		 3684static __poll_t mptcp_poll(struct file *file, struct socket *sock,
3685 struct poll_table_struct *wait)
3686{
1891c4a0 3687 struct sock *sk = sock->sk;
8ab183de 3688 struct mptcp_sock *msk;
2303f994 3689 __poll_t mask = 0;
8a05661b 3690 int state;
2303f994 3691
1891c4a0 3692 msk = mptcp_sk(sk);
1891c4a0 3693 sock_poll_wait(file, sock, wait);
1891c4a0 3694
8a05661b 3695 state = inet_sk_state_load(sk);
6719331c 3696 pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags);
71ba088c
PA		 3697 if (state == TCP_LISTEN) {
3698 if (WARN_ON_ONCE(!msk->subflow || !msk->subflow->sk))
3699 return 0;
3700
3701 return inet_csk_listen_poll(msk->subflow->sk);
3702 }
8a05661b
PA		 3703
3704 if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) {
3705 mask |= mptcp_check_readable(msk);
8edf0864 3706 mask |= mptcp_check_writeable(msk);
8a05661b 3707 }
dd913410
PA		 3708 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
3709 mask |= EPOLLHUP;
1891c4a0
FW		 3710 if (sk->sk_shutdown & RCV_SHUTDOWN)
3711 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
3712
15cc1045
PA		 3713 /* This barrier is coupled with smp_wmb() in tcp_reset() */
3714 smp_rmb();
3715 if (sk->sk_err)
3716 mask |= EPOLLERR;
3717
2303f994
PK		 3718 return mask;
3719}
3720
e42f1ac6
FW		 3721static const struct proto_ops mptcp_stream_ops = {
3722 .family = PF_INET,
3723 .owner = THIS_MODULE,
0a3cc579 3724 .release = inet_release,
e42f1ac6
FW		 3725 .bind = mptcp_bind,
3726 .connect = mptcp_stream_connect,
3727 .socketpair = sock_no_socketpair,
3728 .accept = mptcp_stream_accept,
d2f77c53 3729 .getname = inet_getname,
e42f1ac6
FW		 3730 .poll = mptcp_poll,
3731 .ioctl = inet_ioctl,
3732 .gettstamp = sock_gettstamp,
3733 .listen = mptcp_listen,
76e2a55d 3734 .shutdown = inet_shutdown,
e42f1ac6
FW		 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,
e42f1ac6 3741};
2303f994 3742
f870fa0b
MM		 3743static struct inet_protosw mptcp_protosw = {
3744 .type = SOCK_STREAM,
3745 .protocol = IPPROTO_MPTCP,
3746 .prot = &mptcp_prot,
2303f994
PK		 3747 .ops = &mptcp_stream_ops,
3748 .flags = INET_PROTOSW_ICSK,
f870fa0b
MM		 3749};
3750
b19bc294
PA		 3751static int mptcp_napi_poll(struct napi_struct *napi, int budget)
3752{
3753 struct mptcp_delegated_action *delegated;
3754 struct mptcp_subflow_context *subflow;
3755 int work_done = 0;
3756
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);
3760
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.
3769 */
3770 bh_unlock_sock(ssk);
3771 sock_put(ssk);
3772
3773 if (++work_done == budget)
3774 return budget;
3775 }
3776
3777 /* always provide a 0 'work_done' argument, so that napi_complete_done
3778 * will not try accessing the NULL napi->dev ptr
3779 */
3780 napi_complete_done(napi, 0);
3781 return work_done;
3782}
3783
d39dceca 3784void __init mptcp_proto_init(void)
f870fa0b 3785{
b19bc294
PA		 3786 struct mptcp_delegated_action *delegated;
3787 int cpu;
3788
2303f994 3789 mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;
2303f994 3790
d027236c
PA		 3791 if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL))
3792 panic("Failed to allocate MPTCP pcpu counter\n");
3793
b19bc294
PA		 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);
16d083e2
JK		 3798 netif_napi_add_tx(&mptcp_napi_dev, &delegated->napi,
3799 mptcp_napi_poll);
b19bc294
PA		 3800 napi_enable(&delegated->napi);
3801 }
3802
2303f994 3803 mptcp_subflow_init();
1b1c7a0e 3804 mptcp_pm_init();
2c5ebd00 3805 mptcp_token_init();
2303f994 3806
f870fa0b
MM		 3807 if (proto_register(&mptcp_prot, 1) != 0)
3808 panic("Failed to register MPTCP proto.\n");
3809
3810 inet_register_protosw(&mptcp_protosw);
6771bfd9
FW		 3811
3812 BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, cb));
f870fa0b
MM		 3813}
3814
3815#if IS_ENABLED(CONFIG_MPTCP_IPV6)
e42f1ac6
FW		 3816static const struct proto_ops mptcp_v6_stream_ops = {
3817 .family = PF_INET6,
3818 .owner = THIS_MODULE,
0a3cc579 3819 .release = inet6_release,
e42f1ac6
FW		 3820 .bind = mptcp_bind,
3821 .connect = mptcp_stream_connect,
3822 .socketpair = sock_no_socketpair,
3823 .accept = mptcp_stream_accept,
d2f77c53 3824 .getname = inet6_getname,
e42f1ac6
FW		 3825 .poll = mptcp_poll,
3826 .ioctl = inet6_ioctl,
3827 .gettstamp = sock_gettstamp,
3828 .listen = mptcp_listen,
76e2a55d 3829 .shutdown = inet_shutdown,
e42f1ac6
FW		 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
3986912f 3837 .compat_ioctl = inet6_compat_ioctl,
e42f1ac6
FW		 3838#endif
3839};
3840
f870fa0b
MM		 3841static struct proto mptcp_v6_prot;
3842
79c0949e
PK		 3843static void mptcp_v6_destroy(struct sock *sk)
3844{
3845 mptcp_destroy(sk);
3846 inet6_destroy_sock(sk);
3847}
3848
f870fa0b
MM		 3849static struct inet_protosw mptcp_v6_protosw = {
3850 .type = SOCK_STREAM,
3851 .protocol = IPPROTO_MPTCP,
3852 .prot = &mptcp_v6_prot,
2303f994 3853 .ops = &mptcp_v6_stream_ops,
f870fa0b
MM		 3854 .flags = INET_PROTOSW_ICSK,
3855};
3856
d39dceca 3857int __init mptcp_proto_v6_init(void)
f870fa0b
MM		 3858{
3859 int err;
3860
3861 mptcp_v6_prot = mptcp_prot;
3862 strcpy(mptcp_v6_prot.name, "MPTCPv6");
3863 mptcp_v6_prot.slab = NULL;
79c0949e 3864 mptcp_v6_prot.destroy = mptcp_v6_destroy;
b0519de8 3865 mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock);
f870fa0b
MM		 3866
3867 err = proto_register(&mptcp_v6_prot, 1);
3868 if (err)
3869 return err;
3870
3871 err = inet6_register_protosw(&mptcp_v6_protosw);
3872 if (err)
3873 proto_unregister(&mptcp_v6_prot);
3874
3875 return err;
3876}
3877#endif
Linux 6.x block layer and io_uring tree(s)