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ASoC: Merge up v6.6-rc7
[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
b7f653b2
FW		 39enum {
40 MPTCP_CMSG_TS = BIT(0),
2c9e7765 41 MPTCP_CMSG_INQ = BIT(1),
b7f653b2
FW		 42};
43
91b6d325 44static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp;
d027236c 45
e16163b6 46static void __mptcp_destroy_sock(struct sock *sk);
81c1d029 47static void mptcp_check_send_data_fin(struct sock *sk);
e16163b6 48
b19bc294
PA		 49DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
50static struct net_device mptcp_napi_dev;
51
6f8a612a
FW		 52/* Returns end sequence number of the receiver's advertised window */
53static u64 mptcp_wnd_end(const struct mptcp_sock *msk)
54{
7439d687 55 return READ_ONCE(msk->wnd_end);
6f8a612a
FW		 56}
57
d2f77c53 58static bool mptcp_is_tcpsk(struct sock *sk)
0b4f33de
FW		 59{
60 struct socket *sock = sk->sk_socket;
61
0b4f33de
FW		 62 if (unlikely(sk->sk_prot == &tcp_prot)) {
63 /* we are being invoked after mptcp_accept() has
64 * accepted a non-mp-capable flow: sk is a tcp_sk,
65 * not an mptcp one.
66 *
67 * Hand the socket over to tcp so all further socket ops
68 * bypass mptcp.
69 */
1ded5e5a 70 WRITE_ONCE(sock->ops, &inet_stream_ops);
d2f77c53 71 return true;
0b4f33de
FW		 72#if IS_ENABLED(CONFIG_MPTCP_IPV6)
73 } else if (unlikely(sk->sk_prot == &tcpv6_prot)) {
1ded5e5a 74 WRITE_ONCE(sock->ops, &inet6_stream_ops);
d2f77c53 75 return true;
0b4f33de
FW		 76#endif
77 }
78
d2f77c53 79 return false;
0b4f33de
FW		 80}
81
fa68018d 82static int __mptcp_socket_create(struct mptcp_sock *msk)
2303f994
PK		 83{
84 struct mptcp_subflow_context *subflow;
85 struct sock *sk = (struct sock *)msk;
86 struct socket *ssock;
87 int err;
88
6bc1fe7d 89 err = mptcp_subflow_create_socket(sk, sk->sk_family, &ssock);
2303f994 90 if (err)
fa68018d 91 return err;
2303f994 92
b8dc6d6c 93 msk->scaling_ratio = tcp_sk(ssock->sk)->scaling_ratio;
1b1b43ee 94 WRITE_ONCE(msk->first, ssock->sk);
2303f994 95 subflow = mptcp_subflow_ctx(ssock->sk);
cec37a6e 96 list_add(&subflow->node, &msk->conn_list);
e16163b6 97 sock_hold(ssock->sk);
2303f994 98 subflow->request_mptcp = 1;
6f06b4d4 99 subflow->subflow_id = msk->subflow_id++;
4cf86ae8
PA		 100
101 /* This is the first subflow, always with id 0 */
102 subflow->local_id_valid = 1;
866f26f2 103 mptcp_sock_graft(msk->first, sk->sk_socket);
39880bd8 104 iput(SOCK_INODE(ssock));
e1ff9e82 105
fa68018d 106 return 0;
2303f994
PK		 107}
108
ddb1a072
PA		 109/* If the MPC handshake is not started, returns the first subflow,
110 * eventually allocating it.
111 */
3f326a82 112struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk)
ddb1a072
PA		 113{
114 struct sock *sk = (struct sock *)msk;
115 int ret;
116
117 if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
118 return ERR_PTR(-EINVAL);
119
3f326a82 120 if (!msk->first) {
ddb1a072
PA		 121 ret = __mptcp_socket_create(msk);
122 if (ret)
123 return ERR_PTR(ret);
124
125 mptcp_sockopt_sync(msk, msk->first);
126 }
127
3f326a82 128 return msk->first;
ddb1a072
PA		 129}
130
ab174ad8
PA		 131static void mptcp_drop(struct sock *sk, struct sk_buff *skb)
132{
133 sk_drops_add(sk, skb);
134 __kfree_skb(skb);
135}
136
9531e4a8
ED		 137static void mptcp_rmem_fwd_alloc_add(struct sock *sk, int size)
138{
139 WRITE_ONCE(mptcp_sk(sk)->rmem_fwd_alloc,
140 mptcp_sk(sk)->rmem_fwd_alloc + size);
141}
142
6511882c
PA		 143static void mptcp_rmem_charge(struct sock *sk, int size)
144{
9531e4a8 145 mptcp_rmem_fwd_alloc_add(sk, -size);
6511882c
PA		 146}
147
8268ed4c
PA		 148static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
149 struct sk_buff *from)
150{
151 bool fragstolen;
152 int delta;
153
154 if (MPTCP_SKB_CB(from)->offset ||
155 !skb_try_coalesce(to, from, &fragstolen, &delta))
156 return false;
157
06242e44
PA		 158 pr_debug("colesced seq %llx into %llx new len %d new end seq %llx",
159 MPTCP_SKB_CB(from)->map_seq, MPTCP_SKB_CB(to)->map_seq,
160 to->len, MPTCP_SKB_CB(from)->end_seq);
ab174ad8 161 MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq;
7288ff6e
PA		 162
163 /* note the fwd memory can reach a negative value after accounting
164 * for the delta, but the later skb free will restore a non
165 * negative one
166 */
8268ed4c 167 atomic_add(delta, &sk->sk_rmem_alloc);
6511882c 168 mptcp_rmem_charge(sk, delta);
7288ff6e
PA		 169 kfree_skb_partial(from, fragstolen);
170
8268ed4c
PA		 171 return true;
172}
173
ab174ad8
PA		 174static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to,
175 struct sk_buff *from)
176{
177 if (MPTCP_SKB_CB(from)->map_seq != MPTCP_SKB_CB(to)->end_seq)
178 return false;
179
180 return mptcp_try_coalesce((struct sock *)msk, to, from);
181}
182
6511882c
PA		 183static void __mptcp_rmem_reclaim(struct sock *sk, int amount)
184{
100fdd1f 185 amount >>= PAGE_SHIFT;
9531e4a8 186 mptcp_rmem_charge(sk, amount << PAGE_SHIFT);
6511882c
PA		 187 __sk_mem_reduce_allocated(sk, amount);
188}
189
190static void mptcp_rmem_uncharge(struct sock *sk, int size)
191{
192 struct mptcp_sock *msk = mptcp_sk(sk);
193 int reclaimable;
194
9531e4a8 195 mptcp_rmem_fwd_alloc_add(sk, size);
6511882c
PA		 196 reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
197
198 /* see sk_mem_uncharge() for the rationale behind the following schema */
d24141fe
PA		 199 if (unlikely(reclaimable >= PAGE_SIZE))
200 __mptcp_rmem_reclaim(sk, reclaimable);
6511882c
PA		 201}
202
203static void mptcp_rfree(struct sk_buff *skb)
204{
205 unsigned int len = skb->truesize;
206 struct sock *sk = skb->sk;
207
208 atomic_sub(len, &sk->sk_rmem_alloc);
209 mptcp_rmem_uncharge(sk, len);
210}
211
36b122ba 212void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk)
6511882c
PA		 213{
214 skb_orphan(skb);
215 skb->sk = sk;
216 skb->destructor = mptcp_rfree;
217 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
218 mptcp_rmem_charge(sk, skb->truesize);
219}
220
ab174ad8
PA		 221/* "inspired" by tcp_data_queue_ofo(), main differences:
222 * - use mptcp seqs
223 * - don't cope with sacks
224 */
225static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
226{
227 struct sock *sk = (struct sock *)msk;
228 struct rb_node **p, *parent;
229 u64 seq, end_seq, max_seq;
230 struct sk_buff *skb1;
231
232 seq = MPTCP_SKB_CB(skb)->map_seq;
233 end_seq = MPTCP_SKB_CB(skb)->end_seq;
f3589be0 234 max_seq = atomic64_read(&msk->rcv_wnd_sent);
ab174ad8 235
06242e44
PA		 236 pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq,
237 RB_EMPTY_ROOT(&msk->out_of_order_queue));
fa3fe2b1 238 if (after64(end_seq, max_seq)) {
ab174ad8
PA		 239 /* out of window */
240 mptcp_drop(sk, skb);
fa3fe2b1
FW		 241 pr_debug("oow by %lld, rcv_wnd_sent %llu\n",
242 (unsigned long long)end_seq - (unsigned long)max_seq,
f3589be0 243 (unsigned long long)atomic64_read(&msk->rcv_wnd_sent));
06242e44 244 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW);
ab174ad8
PA		 245 return;
246 }
247
248 p = &msk->out_of_order_queue.rb_node;
06242e44 249 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE);
ab174ad8
PA		 250 if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) {
251 rb_link_node(&skb->rbnode, NULL, p);
252 rb_insert_color(&skb->rbnode, &msk->out_of_order_queue);
253 msk->ooo_last_skb = skb;
254 goto end;
255 }
256
257 /* with 2 subflows, adding at end of ooo queue is quite likely
258 * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
259 */
06242e44
PA		 260 if (mptcp_ooo_try_coalesce(msk, msk->ooo_last_skb, skb)) {
261 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
262 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
ab174ad8 263 return;
06242e44 264 }
ab174ad8
PA		 265
266 /* Can avoid an rbtree lookup if we are adding skb after ooo_last_skb */
267 if (!before64(seq, MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq)) {
06242e44 268 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
ab174ad8
PA		 269 parent = &msk->ooo_last_skb->rbnode;
270 p = &parent->rb_right;
271 goto insert;
272 }
273
274 /* Find place to insert this segment. Handle overlaps on the way. */
275 parent = NULL;
276 while (*p) {
277 parent = *p;
278 skb1 = rb_to_skb(parent);
279 if (before64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
280 p = &parent->rb_left;
281 continue;
282 }
283 if (before64(seq, MPTCP_SKB_CB(skb1)->end_seq)) {
284 if (!after64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) {
285 /* All the bits are present. Drop. */
286 mptcp_drop(sk, skb);
06242e44 287 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 288 return;
289 }
290 if (after64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
291 /* partial overlap:
292 * | skb |
293 * | skb1 |
294 * continue traversing
295 */
296 } else {
297 /* skb's seq == skb1's seq and skb covers skb1.
298 * Replace skb1 with skb.
299 */
300 rb_replace_node(&skb1->rbnode, &skb->rbnode,
301 &msk->out_of_order_queue);
302 mptcp_drop(sk, skb1);
06242e44 303 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 304 goto merge_right;
305 }
306 } else if (mptcp_ooo_try_coalesce(msk, skb1, skb)) {
06242e44 307 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
ab174ad8
PA		 308 return;
309 }
310 p = &parent->rb_right;
311 }
06242e44 312
ab174ad8
PA		 313insert:
314 /* Insert segment into RB tree. */
315 rb_link_node(&skb->rbnode, parent, p);
316 rb_insert_color(&skb->rbnode, &msk->out_of_order_queue);
317
318merge_right:
319 /* Remove other segments covered by skb. */
320 while ((skb1 = skb_rb_next(skb)) != NULL) {
321 if (before64(end_seq, MPTCP_SKB_CB(skb1)->end_seq))
322 break;
323 rb_erase(&skb1->rbnode, &msk->out_of_order_queue);
324 mptcp_drop(sk, skb1);
06242e44 325 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 326 }
327 /* If there is no skb after us, we are the last_skb ! */
328 if (!skb1)
329 msk->ooo_last_skb = skb;
330
331end:
332 skb_condense(skb);
6511882c
PA		 333 mptcp_set_owner_r(skb, sk);
334}
335
336static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
337{
338 struct mptcp_sock *msk = mptcp_sk(sk);
339 int amt, amount;
340
69d93dae 341 if (size <= msk->rmem_fwd_alloc)
6511882c
PA		 342 return true;
343
69d93dae 344 size -= msk->rmem_fwd_alloc;
6511882c 345 amt = sk_mem_pages(size);
100fdd1f 346 amount = amt << PAGE_SHIFT;
4aaa1685
PA		 347 if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
348 return false;
6511882c 349
9531e4a8 350 mptcp_rmem_fwd_alloc_add(sk, amount);
6511882c 351 return true;
ab174ad8
PA		 352}
353
354static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
355 struct sk_buff *skb, unsigned int offset,
356 size_t copy_len)
6771bfd9 357{
ab174ad8 358 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
6771bfd9 359 struct sock *sk = (struct sock *)msk;
4e637c70 360 struct sk_buff *tail;
b7f653b2 361 bool has_rxtstamp;
6771bfd9
FW		 362
363 __skb_unlink(skb, &ssk->sk_receive_queue);
6771bfd9 364
4e637c70
FW		 365 skb_ext_reset(skb);
366 skb_orphan(skb);
ab174ad8 367
9c3f94e1 368 /* try to fetch required memory from subflow */
6511882c
PA		 369 if (!mptcp_rmem_schedule(sk, ssk, skb->truesize))
370 goto drop;
9c3f94e1 371
b7f653b2
FW		 372 has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp;
373
ab174ad8
PA		 374 /* the skb map_seq accounts for the skb offset:
375 * mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq
376 * value
377 */
378 MPTCP_SKB_CB(skb)->map_seq = mptcp_subflow_get_mapped_dsn(subflow);
379 MPTCP_SKB_CB(skb)->end_seq = MPTCP_SKB_CB(skb)->map_seq + copy_len;
8268ed4c 380 MPTCP_SKB_CB(skb)->offset = offset;
b7f653b2 381 MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp;
4e637c70 382
ab174ad8
PA		 383 if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) {
384 /* in sequence */
38967f42 385 msk->bytes_received += copy_len;
8b0308fe 386 WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len);
ab174ad8
PA		 387 tail = skb_peek_tail(&sk->sk_receive_queue);
388 if (tail && mptcp_try_coalesce(sk, tail, skb))
389 return true;
4e637c70 390
6511882c 391 mptcp_set_owner_r(skb, sk);
ab174ad8
PA		 392 __skb_queue_tail(&sk->sk_receive_queue, skb);
393 return true;
394 } else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) {
395 mptcp_data_queue_ofo(msk, skb);
396 return false;
397 }
398
399 /* old data, keep it simple and drop the whole pkt, sender
400 * will retransmit as needed, if needed.
401 */
06242e44 402 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
9c3f94e1 403drop:
ab174ad8
PA		 404 mptcp_drop(sk, skb);
405 return false;
6771bfd9
FW		 406}
407
f6909dc1 408static void mptcp_stop_rtx_timer(struct sock *sk)
16a9a9da
MM		 409{
410 struct inet_connection_sock *icsk = inet_csk(sk);
411
412 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
413 mptcp_sk(sk)->timer_ival = 0;
414}
415
e16163b6
PA		 416static void mptcp_close_wake_up(struct sock *sk)
417{
418 if (sock_flag(sk, SOCK_DEAD))
419 return;
420
421 sk->sk_state_change(sk);
422 if (sk->sk_shutdown == SHUTDOWN_MASK ||
423 sk->sk_state == TCP_CLOSE)
424 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
425 else
426 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
427}
428
6e628cd3 429static bool mptcp_pending_data_fin_ack(struct sock *sk)
16a9a9da
MM		 430{
431 struct mptcp_sock *msk = mptcp_sk(sk);
432
81c1d029 433 return ((1 << sk->sk_state) &
6e628cd3
PA		 434 (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK)) &&
435 msk->write_seq == READ_ONCE(msk->snd_una);
436}
437
438static void mptcp_check_data_fin_ack(struct sock *sk)
439{
440 struct mptcp_sock *msk = mptcp_sk(sk);
16a9a9da
MM		 441
442 /* Look for an acknowledged DATA_FIN */
6e628cd3 443 if (mptcp_pending_data_fin_ack(sk)) {
16a9a9da
MM		 444 WRITE_ONCE(msk->snd_data_fin_enable, 0);
445
446 switch (sk->sk_state) {
447 case TCP_FIN_WAIT1:
448 inet_sk_state_store(sk, TCP_FIN_WAIT2);
16a9a9da
MM		 449 break;
450 case TCP_CLOSING:
16a9a9da
MM		 451 case TCP_LAST_ACK:
452 inet_sk_state_store(sk, TCP_CLOSE);
16a9a9da
MM		 453 break;
454 }
455
e16163b6 456 mptcp_close_wake_up(sk);
16a9a9da
MM		 457 }
458}
459
3721b9b6
MM		 460static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq)
461{
462 struct mptcp_sock *msk = mptcp_sk(sk);
463
464 if (READ_ONCE(msk->rcv_data_fin) &&
465 ((1 << sk->sk_state) &
466 (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2))) {
467 u64 rcv_data_fin_seq = READ_ONCE(msk->rcv_data_fin_seq);
468
469 if (msk->ack_seq == rcv_data_fin_seq) {
470 if (seq)
471 *seq = rcv_data_fin_seq;
472
473 return true;
474 }
475 }
476
477 return false;
478}
479
403a40f2 480static void mptcp_set_datafin_timeout(struct sock *sk)
6477dd39
MM		 481{
482 struct inet_connection_sock *icsk = inet_csk(sk);
877d11f0 483 u32 retransmits;
6477dd39 484
877d11f0
MM		 485 retransmits = min_t(u32, icsk->icsk_retransmits,
486 ilog2(TCP_RTO_MAX / TCP_RTO_MIN));
487
488 mptcp_sk(sk)->timer_ival = TCP_RTO_MIN << retransmits;
6477dd39
MM		 489}
490
33d41c9c 491static void __mptcp_set_timeout(struct sock *sk, long tout)
3721b9b6 492{
3721b9b6
MM		 493 mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN;
494}
495
33d41c9c
PA		 496static long mptcp_timeout_from_subflow(const struct mptcp_subflow_context *subflow)
497{
498 const struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
499
71b7dec2
PA		 500 return inet_csk(ssk)->icsk_pending && !subflow->stale_count ?
501 inet_csk(ssk)->icsk_timeout - jiffies : 0;
33d41c9c
PA		 502}
503
504static void mptcp_set_timeout(struct sock *sk)
505{
506 struct mptcp_subflow_context *subflow;
507 long tout = 0;
508
509 mptcp_for_each_subflow(mptcp_sk(sk), subflow)
510 tout = max(tout, mptcp_timeout_from_subflow(subflow));
511 __mptcp_set_timeout(sk, tout);
512}
513
76a13b31 514static inline bool tcp_can_send_ack(const struct sock *ssk)
fd897679
PA		 515{
516 return !((1 << inet_sk_state_load(ssk)) &
20bc80b6 517 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN));
fd897679
PA		 518}
519
a6574302
MM		 520void __mptcp_subflow_send_ack(struct sock *ssk)
521{
522 if (tcp_can_send_ack(ssk))
523 tcp_send_ack(ssk);
524}
525
f5360e9b 526static void mptcp_subflow_send_ack(struct sock *ssk)
340fa666
MM		 527{
528 bool slow;
529
530 slow = lock_sock_fast(ssk);
a6574302 531 __mptcp_subflow_send_ack(ssk);
340fa666
MM		 532 unlock_sock_fast(ssk, slow);
533}
534
fd897679 535static void mptcp_send_ack(struct mptcp_sock *msk)
7ed90803
PA		 536{
537 struct mptcp_subflow_context *subflow;
538
340fa666
MM		 539 mptcp_for_each_subflow(msk, subflow)
540 mptcp_subflow_send_ack(mptcp_subflow_tcp_sock(subflow));
fd897679
PA		 541}
542
fde56eea 543static void mptcp_subflow_cleanup_rbuf(struct sock *ssk)
fd897679 544{
75e908c3 545 bool slow;
fd897679 546
75e908c3 547 slow = lock_sock_fast(ssk);
fde56eea 548 if (tcp_can_send_ack(ssk))
fd897679 549 tcp_cleanup_rbuf(ssk, 1);
75e908c3 550 unlock_sock_fast(ssk, slow);
fde56eea
PA		 551}
552
553static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_empty)
554{
555 const struct inet_connection_sock *icsk = inet_csk(ssk);
c4512c63 556 u8 ack_pending = READ_ONCE(icsk->icsk_ack.pending);
fde56eea
PA		 557 const struct tcp_sock *tp = tcp_sk(ssk);
558
559 return (ack_pending & ICSK_ACK_SCHED) &&
560 ((READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->rcv_wup) >
561 READ_ONCE(icsk->icsk_ack.rcv_mss)) ||
562 (rx_empty && ack_pending &
563 (ICSK_ACK_PUSHED2 | ICSK_ACK_PUSHED)));
fd897679
PA		 564}
565
566static void mptcp_cleanup_rbuf(struct mptcp_sock *msk)
567{
e3859603 568 int old_space = READ_ONCE(msk->old_wspace);
fd897679 569 struct mptcp_subflow_context *subflow;
e3859603 570 struct sock *sk = (struct sock *)msk;
fde56eea
PA		 571 int space = __mptcp_space(sk);
572 bool cleanup, rx_empty;
e3859603 573
fde56eea 574 cleanup = (space > 0) && (space >= (old_space << 1));
ce599c51 575 rx_empty = !__mptcp_rmem(sk);
fd897679 576
fde56eea
PA		 577 mptcp_for_each_subflow(msk, subflow) {
578 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
fd897679 579
fde56eea
PA		 580 if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty))
581 mptcp_subflow_cleanup_rbuf(ssk);
7ed90803
PA		 582 }
583}
584
585static bool mptcp_check_data_fin(struct sock *sk)
3721b9b6
MM		 586{
587 struct mptcp_sock *msk = mptcp_sk(sk);
588 u64 rcv_data_fin_seq;
7ed90803 589 bool ret = false;
3721b9b6 590
3721b9b6
MM		 591 /* Need to ack a DATA_FIN received from a peer while this side
592 * of the connection is in ESTABLISHED, FIN_WAIT1, or FIN_WAIT2.
593 * msk->rcv_data_fin was set when parsing the incoming options
594 * at the subflow level and the msk lock was not held, so this
595 * is the first opportunity to act on the DATA_FIN and change
596 * the msk state.
597 *
598 * If we are caught up to the sequence number of the incoming
599 * DATA_FIN, send the DATA_ACK now and do state transition. If
600 * not caught up, do nothing and let the recv code send DATA_ACK
601 * when catching up.
602 */
603
604 if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) {
917944da 605 WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1);
3721b9b6
MM		 606 WRITE_ONCE(msk->rcv_data_fin, 0);
607
6b9831bf 608 WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | RCV_SHUTDOWN);
16a9a9da 609 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
3721b9b6
MM		 610
611 switch (sk->sk_state) {
612 case TCP_ESTABLISHED:
613 inet_sk_state_store(sk, TCP_CLOSE_WAIT);
614 break;
615 case TCP_FIN_WAIT1:
616 inet_sk_state_store(sk, TCP_CLOSING);
617 break;
618 case TCP_FIN_WAIT2:
619 inet_sk_state_store(sk, TCP_CLOSE);
3721b9b6
MM		 620 break;
621 default:
622 /* Other states not expected */
623 WARN_ON_ONCE(1);
624 break;
625 }
626
7ed90803 627 ret = true;
81c1d029
PA		 628 if (!__mptcp_check_fallback(msk))
629 mptcp_send_ack(msk);
e16163b6 630 mptcp_close_wake_up(sk);
3721b9b6 631 }
7ed90803 632 return ret;
3721b9b6
MM		 633}
634
6771bfd9
FW		 635static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
636 struct sock *ssk,
637 unsigned int *bytes)
638{
639 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
600911ff 640 struct sock *sk = (struct sock *)msk;
6771bfd9
FW		 641 unsigned int moved = 0;
642 bool more_data_avail;
643 struct tcp_sock *tp;
644 bool done = false;
13c7ba0c
FW		 645 int sk_rbuf;
646
647 sk_rbuf = READ_ONCE(sk->sk_rcvbuf);
648
649 if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
650 int ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf);
651
652 if (unlikely(ssk_rbuf > sk_rbuf)) {
653 WRITE_ONCE(sk->sk_rcvbuf, ssk_rbuf);
654 sk_rbuf = ssk_rbuf;
655 }
656 }
600911ff 657
ab174ad8 658 pr_debug("msk=%p ssk=%p", msk, ssk);
6771bfd9
FW		 659 tp = tcp_sk(ssk);
660 do {
661 u32 map_remaining, offset;
662 u32 seq = tp->copied_seq;
663 struct sk_buff *skb;
664 bool fin;
665
666 /* try to move as much data as available */
667 map_remaining = subflow->map_data_len -
668 mptcp_subflow_get_map_offset(subflow);
669
670 skb = skb_peek(&ssk->sk_receive_queue);
d9fb8c50 671 if (!skb) {
d89e3ed7
PA		 672 /* With racing move_skbs_to_msk() and __mptcp_move_skbs(),
673 * a different CPU can have already processed the pending
674 * data, stop here or we can enter an infinite loop
d9fb8c50
PA		 675 */
676 if (!moved)
677 done = true;
6771bfd9 678 break;
d9fb8c50 679 }
6771bfd9 680
e1ff9e82 681 if (__mptcp_check_fallback(msk)) {
d89e3ed7
PA		 682 /* Under fallback skbs have no MPTCP extension and TCP could
683 * collapse them between the dummy map creation and the
684 * current dequeue. Be sure to adjust the map size.
e1ff9e82
DC		 685 */
686 map_remaining = skb->len;
687 subflow->map_data_len = skb->len;
688 }
689
6771bfd9
FW		 690 offset = seq - TCP_SKB_CB(skb)->seq;
691 fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
692 if (fin) {
693 done = true;
694 seq++;
695 }
696
697 if (offset < skb->len) {
698 size_t len = skb->len - offset;
699
700 if (tp->urg_data)
701 done = true;
702
ab174ad8
PA		 703 if (__mptcp_move_skb(msk, ssk, skb, offset, len))
704 moved += len;
6771bfd9 705 seq += len;
6771bfd9
FW		 706
707 if (WARN_ON_ONCE(map_remaining < len))
708 break;
709 } else {
710 WARN_ON_ONCE(!fin);
711 sk_eat_skb(ssk, skb);
712 done = true;
713 }
714
715 WRITE_ONCE(tp->copied_seq, seq);
716 more_data_avail = mptcp_subflow_data_available(ssk);
600911ff 717
13c7ba0c 718 if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) {
600911ff
FW		 719 done = true;
720 break;
721 }
6771bfd9
FW		 722 } while (more_data_avail);
723
6719331c 724 *bytes += moved;
6771bfd9
FW		 725 return done;
726}
727
87952603 728static bool __mptcp_ofo_queue(struct mptcp_sock *msk)
ab174ad8
PA		 729{
730 struct sock *sk = (struct sock *)msk;
731 struct sk_buff *skb, *tail;
732 bool moved = false;
733 struct rb_node *p;
734 u64 end_seq;
735
736 p = rb_first(&msk->out_of_order_queue);
06242e44 737 pr_debug("msk=%p empty=%d", msk, RB_EMPTY_ROOT(&msk->out_of_order_queue));
ab174ad8
PA		 738 while (p) {
739 skb = rb_to_skb(p);
740 if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq))
741 break;
742
743 p = rb_next(p);
744 rb_erase(&skb->rbnode, &msk->out_of_order_queue);
745
746 if (unlikely(!after64(MPTCP_SKB_CB(skb)->end_seq,
747 msk->ack_seq))) {
748 mptcp_drop(sk, skb);
06242e44 749 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
ab174ad8
PA		 750 continue;
751 }
752
753 end_seq = MPTCP_SKB_CB(skb)->end_seq;
754 tail = skb_peek_tail(&sk->sk_receive_queue);
755 if (!tail || !mptcp_ooo_try_coalesce(msk, tail, skb)) {
756 int delta = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq;
757
758 /* skip overlapping data, if any */
06242e44
PA		 759 pr_debug("uncoalesced seq=%llx ack seq=%llx delta=%d",
760 MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq,
761 delta);
ab174ad8 762 MPTCP_SKB_CB(skb)->offset += delta;
2c9e7765 763 MPTCP_SKB_CB(skb)->map_seq += delta;
ab174ad8
PA		 764 __skb_queue_tail(&sk->sk_receive_queue, skb);
765 }
38967f42 766 msk->bytes_received += end_seq - msk->ack_seq;
ab174ad8
PA		 767 msk->ack_seq = end_seq;
768 moved = true;
769 }
770 return moved;
771}
772
9f1a9881 773static bool __mptcp_subflow_error_report(struct sock *sk, struct sock *ssk)
d5fbeff1 774{
9f1a9881
PA		 775 int err = sock_error(ssk);
776 int ssk_state;
d5fbeff1 777
9f1a9881
PA		 778 if (!err)
779 return false;
d5fbeff1 780
9f1a9881
PA		 781 /* only propagate errors on fallen-back sockets or
782 * on MPC connect
783 */
784 if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(mptcp_sk(sk)))
785 return false;
d5fbeff1 786
9f1a9881
PA		 787 /* We need to propagate only transition to CLOSE state.
788 * Orphaned socket will see such state change via
789 * subflow_sched_work_if_closed() and that path will properly
790 * destroy the msk as needed.
791 */
792 ssk_state = inet_sk_state_load(ssk);
793 if (ssk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DEAD))
794 inet_sk_state_store(sk, ssk_state);
795 WRITE_ONCE(sk->sk_err, -err);
796
797 /* This barrier is coupled with smp_rmb() in mptcp_poll() */
798 smp_wmb();
799 sk_error_report(sk);
800 return true;
801}
d5fbeff1 802
9f1a9881
PA		 803void __mptcp_error_report(struct sock *sk)
804{
805 struct mptcp_subflow_context *subflow;
806 struct mptcp_sock *msk = mptcp_sk(sk);
807
808 mptcp_for_each_subflow(msk, subflow)
809 if (__mptcp_subflow_error_report(sk, mptcp_subflow_tcp_sock(subflow)))
810 break;
d5fbeff1
PA		 811}
812
2e52213c
FW		 813/* In most cases we will be able to lock the mptcp socket. If its already
814 * owned, we need to defer to the work queue to avoid ABBA deadlock.
815 */
99d1055c 816static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
2e52213c
FW		 817{
818 struct sock *sk = (struct sock *)msk;
819 unsigned int moved = 0;
820
87952603
PA		 821 __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
822 __mptcp_ofo_queue(msk);
499ada50
PA		 823 if (unlikely(ssk->sk_err)) {
824 if (!sock_owned_by_user(sk))
825 __mptcp_error_report(sk);
826 else
e9d09bac 827 __set_bit(MPTCP_ERROR_REPORT, &msk->cb_flags);
499ada50 828 }
2e52213c 829
87952603
PA		 830 /* If the moves have caught up with the DATA_FIN sequence number
831 * it's time to ack the DATA_FIN and change socket state, but
832 * this is not a good place to change state. Let the workqueue
833 * do it.
834 */
835 if (mptcp_pending_data_fin(sk, NULL))
836 mptcp_schedule_work(sk);
99d1055c 837 return moved > 0;
2e52213c
FW		 838}
839
840void mptcp_data_ready(struct sock *sk, struct sock *ssk)
101f6f85 841{
6719331c 842 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
101f6f85 843 struct mptcp_sock *msk = mptcp_sk(sk);
13c7ba0c 844 int sk_rbuf, ssk_rbuf;
101f6f85 845
d7b1bfd0
PA		 846 /* The peer can send data while we are shutting down this
847 * subflow at msk destruction time, but we must avoid enqueuing
848 * more data to the msk receive queue
849 */
850 if (unlikely(subflow->disposable))
851 return;
852
13c7ba0c
FW		 853 ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf);
854 sk_rbuf = READ_ONCE(sk->sk_rcvbuf);
855 if (unlikely(ssk_rbuf > sk_rbuf))
856 sk_rbuf = ssk_rbuf;
857
99d1055c 858 /* over limit? can't append more skbs to msk, Also, no need to wake-up*/
ce599c51
PA		 859 if (__mptcp_rmem(sk) > sk_rbuf) {
860 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
99d1055c 861 return;
ce599c51 862 }
600911ff 863
99d1055c
PA		 864 /* Wake-up the reader only for in-sequence data */
865 mptcp_data_lock(sk);
612f71d7 866 if (move_skbs_to_msk(msk, ssk))
6719331c 867 sk->sk_data_ready(sk);
612f71d7 868
99d1055c 869 mptcp_data_unlock(sk);
101f6f85
FW		 870}
871
55b47ca7
PA		 872static void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk)
873{
874 mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq);
875 WRITE_ONCE(msk->allow_infinite_fallback, false);
876 mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
877}
878
3e501490 879static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
ec3edaa7 880{
3e501490 881 struct sock *sk = (struct sock *)msk;
5cf92bba 882
3e501490 883 if (sk->sk_state != TCP_ESTABLISHED)
78962489 884 return false;
ec3edaa7 885
3e501490
PA		 886 /* attach to msk socket only after we are sure we will deal with it
887 * at close time
888 */
889 if (sk->sk_socket && !ssk->sk_socket)
890 mptcp_sock_graft(ssk, sk->sk_socket);
78962489 891
6f06b4d4 892 mptcp_subflow_ctx(ssk)->subflow_id = msk->subflow_id++;
3e501490 893 mptcp_sockopt_sync_locked(msk, ssk);
55b47ca7 894 mptcp_subflow_joined(msk, ssk);
27e5ccc2 895 mptcp_stop_tout_timer(sk);
3e501490 896 return true;
78962489
FW		 897}
898
56a666c4 899static void __mptcp_flush_join_list(struct sock *sk, struct list_head *join_list)
78962489 900{
3e501490
PA		 901 struct mptcp_subflow_context *tmp, *subflow;
902 struct mptcp_sock *msk = mptcp_sk(sk);
78962489 903
56a666c4 904 list_for_each_entry_safe(subflow, tmp, join_list, node) {
3e501490
PA		 905 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
906 bool slow = lock_sock_fast(ssk);
78962489 907
3e501490
PA		 908 list_move_tail(&subflow->node, &msk->conn_list);
909 if (!__mptcp_finish_join(msk, ssk))
910 mptcp_subflow_reset(ssk);
911 unlock_sock_fast(ssk, slow);
912 }
ec3edaa7
PK		 913}
914
f6909dc1 915static bool mptcp_rtx_timer_pending(struct sock *sk)
b51f9b80
PA		 916{
917 return timer_pending(&inet_csk(sk)->icsk_retransmit_timer);
918}
919
f6909dc1 920static void mptcp_reset_rtx_timer(struct sock *sk)
b51f9b80
PA		 921{
922 struct inet_connection_sock *icsk = inet_csk(sk);
923 unsigned long tout;
924
e16163b6
PA		 925 /* prevent rescheduling on close */
926 if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE))
927 return;
928
33d41c9c 929 tout = mptcp_sk(sk)->timer_ival;
b51f9b80
PA		 930 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout);
931}
932
ba8f48f7
PA		 933bool mptcp_schedule_work(struct sock *sk)
934{
935 if (inet_sk_state_load(sk) != TCP_CLOSE &&
936 schedule_work(&mptcp_sk(sk)->work)) {
937 /* each subflow already holds a reference to the sk, and the
938 * workqueue is invoked by a subflow, so sk can't go away here.
939 */
940 sock_hold(sk);
941 return true;
942 }
943 return false;
944}
945
7a6a6cbc
PA		 946static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
947{
948 struct mptcp_subflow_context *subflow;
7a6a6cbc 949
109cdeb8 950 msk_owned_by_me(msk);
7a6a6cbc
PA		 951
952 mptcp_for_each_subflow(msk, subflow) {
99d1055c 953 if (READ_ONCE(subflow->data_avail))
7a6a6cbc
PA		 954 return mptcp_subflow_tcp_sock(subflow);
955 }
956
957 return NULL;
958}
959
3f8e0aae
PA		 960static bool mptcp_skb_can_collapse_to(u64 write_seq,
961 const struct sk_buff *skb,
962 const struct mptcp_ext *mpext)
57040755
PA		 963{
964 if (!tcp_skb_can_collapse_to(skb))
965 return false;
966
5a369ca6
PA		 967 /* can collapse only if MPTCP level sequence is in order and this
968 * mapping has not been xmitted yet
969 */
970 return mpext && mpext->data_seq + mpext->data_len == write_seq &&
971 !mpext->frozen;
57040755
PA		 972}
973
29249eac
PA		 974/* we can append data to the given data frag if:
975 * - there is space available in the backing page_frag
976 * - the data frag tail matches the current page_frag free offset
977 * - the data frag end sequence number matches the current write seq
978 */
18b683bf
PA		 979static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
980 const struct page_frag *pfrag,
981 const struct mptcp_data_frag *df)
982{
983 return df && pfrag->page == df->page &&
d9ca1de8 984 pfrag->size - pfrag->offset > 0 &&
29249eac 985 pfrag->offset == (df->offset + df->data_len) &&
18b683bf
PA		 986 df->data_seq + df->data_len == msk->write_seq;
987}
988
d027236c
PA		 989static void dfrag_uncharge(struct sock *sk, int len)
990{
991 sk_mem_uncharge(sk, len);
7948f6cc 992 sk_wmem_queued_add(sk, -len);
d027236c
PA		 993}
994
995static void dfrag_clear(struct sock *sk, struct mptcp_data_frag *dfrag)
18b683bf 996{
d027236c
PA		 997 int len = dfrag->data_len + dfrag->overhead;
998
18b683bf 999 list_del(&dfrag->list);
d027236c 1000 dfrag_uncharge(sk, len);
18b683bf
PA		 1001 put_page(dfrag->page);
1002}
1003
6e628cd3 1004static void __mptcp_clean_una(struct sock *sk)
18b683bf
PA		 1005{
1006 struct mptcp_sock *msk = mptcp_sk(sk);
1007 struct mptcp_data_frag *dtmp, *dfrag;
e1ff9e82
DC		 1008 u64 snd_una;
1009
7439d687 1010 snd_una = msk->snd_una;
18b683bf
PA		 1011 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) {
1012 if (after64(dfrag->data_seq + dfrag->data_len, snd_una))
1013 break;
1014
1e1d9d6f
PA		 1015 if (unlikely(dfrag == msk->first_pending)) {
1016 /* in recovery mode can see ack after the current snd head */
1017 if (WARN_ON_ONCE(!msk->recovery))
1018 break;
1019
1020 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
1021 }
1022
d027236c 1023 dfrag_clear(sk, dfrag);
d027236c
PA		 1024 }
1025
7948f6cc
FW		 1026 dfrag = mptcp_rtx_head(sk);
1027 if (dfrag && after64(snd_una, dfrag->data_seq)) {
53eb4c38
PA		 1028 u64 delta = snd_una - dfrag->data_seq;
1029
1e1d9d6f
PA		 1030 /* prevent wrap around in recovery mode */
1031 if (unlikely(delta > dfrag->already_sent)) {
1032 if (WARN_ON_ONCE(!msk->recovery))
1033 goto out;
1034 if (WARN_ON_ONCE(delta > dfrag->data_len))
1035 goto out;
1036 dfrag->already_sent += delta - dfrag->already_sent;
1037 }
7948f6cc
FW		 1038
1039 dfrag->data_seq += delta;
53eb4c38 1040 dfrag->offset += delta;
7948f6cc 1041 dfrag->data_len -= delta;
d9ca1de8 1042 dfrag->already_sent -= delta;
7948f6cc
FW		 1043
1044 dfrag_uncharge(sk, delta);
7948f6cc
FW		 1045 }
1046
1e1d9d6f
PA		 1047 /* all retransmitted data acked, recovery completed */
1048 if (unlikely(msk->recovery) && after64(msk->snd_una, msk->recovery_snd_nxt))
1049 msk->recovery = false;
1050
53eb4c38 1051out:
3241a9c0
FW		 1052 if (snd_una == READ_ONCE(msk->snd_nxt) &&
1053 snd_una == READ_ONCE(msk->write_seq)) {
f6909dc1
PA		 1054 if (mptcp_rtx_timer_pending(sk) && !mptcp_data_fin_enabled(msk))
1055 mptcp_stop_rtx_timer(sk);
6e628cd3 1056 } else {
f6909dc1 1057 mptcp_reset_rtx_timer(sk);
18b683bf
PA		 1058 }
1059}
1060
417789df
PA		 1061static void __mptcp_clean_una_wakeup(struct sock *sk)
1062{
765ff425
PA		 1063 lockdep_assert_held_once(&sk->sk_lock.slock);
1064
417789df
PA		 1065 __mptcp_clean_una(sk);
1066 mptcp_write_space(sk);
1067}
1068
b5941f06
PA		 1069static void mptcp_clean_una_wakeup(struct sock *sk)
1070{
1071 mptcp_data_lock(sk);
1072 __mptcp_clean_una_wakeup(sk);
1073 mptcp_data_unlock(sk);
1074}
1075
724cfd2e 1076static void mptcp_enter_memory_pressure(struct sock *sk)
18b683bf 1077{
d9ca1de8
PA		 1078 struct mptcp_subflow_context *subflow;
1079 struct mptcp_sock *msk = mptcp_sk(sk);
1080 bool first = true;
1081
18b683bf 1082 sk_stream_moderate_sndbuf(sk);
d9ca1de8
PA		 1083 mptcp_for_each_subflow(msk, subflow) {
1084 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
1085
1086 if (first)
1087 tcp_enter_memory_pressure(ssk);
1088 sk_stream_moderate_sndbuf(ssk);
1089 first = false;
1090 }
724cfd2e
PA		 1091}
1092
1093/* ensure we get enough memory for the frag hdr, beyond some minimal amount of
1094 * data
1095 */
1096static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1097{
1098 if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag),
1099 pfrag, sk->sk_allocation)))
1100 return true;
1101
1102 mptcp_enter_memory_pressure(sk);
18b683bf
PA		 1103 return false;
1104}
1105
1106static struct mptcp_data_frag *
1107mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
1108 int orig_offset)
1109{
1110 int offset = ALIGN(orig_offset, sizeof(long));
1111 struct mptcp_data_frag *dfrag;
1112
1113 dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset);
1114 dfrag->data_len = 0;
1115 dfrag->data_seq = msk->write_seq;
1116 dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
1117 dfrag->offset = offset + sizeof(struct mptcp_data_frag);
d9ca1de8 1118 dfrag->already_sent = 0;
18b683bf
PA		 1119 dfrag->page = pfrag->page;
1120
1121 return dfrag;
1122}
1123
caf971df
PA		 1124struct mptcp_sendmsg_info {
1125 int mss_now;
1126 int size_goal;
d9ca1de8
PA		 1127 u16 limit;
1128 u16 sent;
1129 unsigned int flags;
1094c6fe 1130 bool data_lock_held;
caf971df
PA		 1131};
1132
b713d006
PA		 1133static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *ssk,
1134 u64 data_seq, int avail_size)
6f8a612a
FW		 1135{
1136 u64 window_end = mptcp_wnd_end(msk);
b713d006 1137 u64 mptcp_snd_wnd;
6f8a612a
FW		 1138
1139 if (__mptcp_check_fallback(msk))
1140 return avail_size;
1141
b713d006
PA		 1142 mptcp_snd_wnd = window_end - data_seq;
1143 avail_size = min_t(unsigned int, mptcp_snd_wnd, avail_size);
6f8a612a 1144
92be2f52 1145 if (unlikely(tcp_sk(ssk)->snd_wnd < mptcp_snd_wnd)) {
b713d006 1146 tcp_sk(ssk)->snd_wnd = min_t(u64, U32_MAX, mptcp_snd_wnd);
92be2f52
PA		 1147 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_SNDWNDSHARED);
1148 }
6f8a612a
FW		 1149
1150 return avail_size;
1151}
1152
724cfd2e
PA		 1153static bool __mptcp_add_ext(struct sk_buff *skb, gfp_t gfp)
1154{
1155 struct skb_ext *mpext = __skb_ext_alloc(gfp);
1156
1157 if (!mpext)
1158 return false;
1159 __skb_ext_set(skb, SKB_EXT_MPTCP, mpext);
1160 return true;
1161}
1162
6e628cd3 1163static struct sk_buff *__mptcp_do_alloc_tx_skb(struct sock *sk, gfp_t gfp)
724cfd2e
PA		 1164{
1165 struct sk_buff *skb;
1166
6e628cd3 1167 skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp);
724cfd2e 1168 if (likely(skb)) {
6e628cd3 1169 if (likely(__mptcp_add_ext(skb, gfp))) {
724cfd2e 1170 skb_reserve(skb, MAX_TCP_HEADER);
a52fe46e 1171 skb->ip_summed = CHECKSUM_PARTIAL;
f70cad10 1172 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
724cfd2e
PA		 1173 return skb;
1174 }
1175 __kfree_skb(skb);
1176 } else {
1177 mptcp_enter_memory_pressure(sk);
1178 }
1179 return NULL;
1180}
1181
f70cad10 1182static struct sk_buff *__mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp)
724cfd2e 1183{
724cfd2e
PA		 1184 struct sk_buff *skb;
1185
6e628cd3 1186 skb = __mptcp_do_alloc_tx_skb(sk, gfp);
724cfd2e 1187 if (!skb)
f70cad10 1188 return NULL;
724cfd2e
PA		 1189
1190 if (likely(sk_wmem_schedule(ssk, skb->truesize))) {
f70cad10
PA		 1191 tcp_skb_entail(ssk, skb);
1192 return skb;
724cfd2e 1193 }
3ef3905a 1194 tcp_skb_tsorted_anchor_cleanup(skb);
724cfd2e 1195 kfree_skb(skb);
f70cad10 1196 return NULL;
724cfd2e
PA		 1197}
1198
f70cad10 1199static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, bool data_lock_held)
724cfd2e 1200{
1094c6fe 1201 gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation;
724cfd2e 1202
1094c6fe 1203 return __mptcp_alloc_tx_skb(sk, ssk, gfp);
724cfd2e
PA		 1204}
1205
d0cc2987
GT		 1206/* note: this always recompute the csum on the whole skb, even
1207 * if we just appended a single frag. More status info needed
1208 */
1209static void mptcp_update_data_checksum(struct sk_buff *skb, int added)
1210{
1211 struct mptcp_ext *mpext = mptcp_get_ext(skb);
1212 __wsum csum = ~csum_unfold(mpext->csum);
1213 int offset = skb->len - added;
1214
1215 mpext->csum = csum_fold(csum_block_add(csum, skb_checksum(skb, offset, added, 0), offset));
1216}
1217
1e39e5a3
GT		 1218static void mptcp_update_infinite_map(struct mptcp_sock *msk,
1219 struct sock *ssk,
1220 struct mptcp_ext *mpext)
1221{
1222 if (!mpext)
1223 return;
1224
1225 mpext->infinite_map = 1;
1226 mpext->data_len = 0;
1227
104125b8 1228 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX);
1e39e5a3
GT		 1229 mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
1230 pr_fallback(msk);
d51991e2 1231 mptcp_do_fallback(ssk);
1e39e5a3
GT		 1232}
1233
6d0060f6 1234static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
d9ca1de8 1235 struct mptcp_data_frag *dfrag,
caf971df 1236 struct mptcp_sendmsg_info *info)
6d0060f6 1237{
d9ca1de8 1238 u64 data_seq = dfrag->data_seq + info->sent;
f70cad10 1239 int offset = dfrag->offset + info->sent;
6d0060f6 1240 struct mptcp_sock *msk = mptcp_sk(sk);
6f8a612a 1241 bool zero_window_probe = false;
6d0060f6 1242 struct mptcp_ext *mpext = NULL;
f70cad10
PA		 1243 bool can_coalesce = false;
1244 bool reuse_skb = true;
1245 struct sk_buff *skb;
1246 size_t copy;
1247 int i;
6d0060f6 1248
e4b61351 1249 pr_debug("msk=%p ssk=%p sending dfrag at seq=%llu len=%u already sent=%u",
d9ca1de8
PA		 1250 msk, ssk, dfrag->data_seq, dfrag->data_len, info->sent);
1251
f70cad10
PA		 1252 if (WARN_ON_ONCE(info->sent > info->limit ||
1253 info->limit > dfrag->data_len))
1254 return 0;
1255
c886d702
PA		 1256 if (unlikely(!__tcp_can_send(ssk)))
1257 return -EAGAIN;
1258
d9ca1de8
PA		 1259 /* compute send limit */
1260 info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags);
f70cad10
PA		 1261 copy = info->size_goal;
1262
57040755 1263 skb = tcp_write_queue_tail(ssk);
f70cad10 1264 if (skb && copy > skb->len) {
57040755
PA		 1265 /* Limit the write to the size available in the
1266 * current skb, if any, so that we create at most a new skb.
1267 * Explicitly tells TCP internals to avoid collapsing on later
1268 * queue management operation, to avoid breaking the ext <->
1269 * SSN association set here
1270 */
d9ca1de8 1271 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
1094c6fe 1272 if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) {
57040755 1273 TCP_SKB_CB(skb)->eor = 1;
1094c6fe
PA		 1274 goto alloc_skb;
1275 }
1276
f70cad10
PA		 1277 i = skb_shinfo(skb)->nr_frags;
1278 can_coalesce = skb_can_coalesce(skb, i, dfrag->page, offset);
657b991a 1279 if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) {
f70cad10
PA		 1280 tcp_mark_push(tcp_sk(ssk), skb);
1281 goto alloc_skb;
15e6ca97 1282 }
18b683bf 1283
f70cad10
PA		 1284 copy -= skb->len;
1285 } else {
1094c6fe 1286alloc_skb:
f70cad10
PA		 1287 skb = mptcp_alloc_tx_skb(sk, ssk, info->data_lock_held);
1288 if (!skb)
1289 return -ENOMEM;
1290
1291 i = skb_shinfo(skb)->nr_frags;
1292 reuse_skb = false;
1293 mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
1294 }
1094c6fe 1295
6f8a612a 1296 /* Zero window and all data acked? Probe. */
b713d006 1297 copy = mptcp_check_allowed_size(msk, ssk, data_seq, copy);
f70cad10 1298 if (copy == 0) {
7439d687
PA		 1299 u64 snd_una = READ_ONCE(msk->snd_una);
1300
72377ab2 1301 if (snd_una != msk->snd_nxt || tcp_write_queue_tail(ssk)) {
27728ba8 1302 tcp_remove_empty_skb(ssk);
6f8a612a 1303 return 0;
f70cad10
PA		 1304 }
1305
6f8a612a 1306 zero_window_probe = true;
7439d687 1307 data_seq = snd_una - 1;
f70cad10 1308 copy = 1;
f70cad10 1309 }
d027236c 1310
f70cad10
PA		 1311 copy = min_t(size_t, copy, info->limit - info->sent);
1312 if (!sk_wmem_schedule(ssk, copy)) {
27728ba8 1313 tcp_remove_empty_skb(ssk);
e2223995 1314 return -ENOMEM;
35759383 1315 }
18b683bf 1316
f70cad10
PA		 1317 if (can_coalesce) {
1318 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1319 } else {
1320 get_page(dfrag->page);
1321 skb_fill_page_desc(skb, i, dfrag->page, offset, copy);
57040755
PA		 1322 }
1323
f70cad10
PA		 1324 skb->len += copy;
1325 skb->data_len += copy;
1326 skb->truesize += copy;
1327 sk_wmem_queued_add(ssk, copy);
1328 sk_mem_charge(ssk, copy);
f70cad10
PA		 1329 WRITE_ONCE(tcp_sk(ssk)->write_seq, tcp_sk(ssk)->write_seq + copy);
1330 TCP_SKB_CB(skb)->end_seq += copy;
1331 tcp_skb_pcount_set(skb, 0);
1332
1333 /* on skb reuse we just need to update the DSS len */
1334 if (reuse_skb) {
1335 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1336 mpext->data_len += copy;
f70cad10 1337 goto out;
724cfd2e 1338 }
6d0060f6
MM		 1339
1340 memset(mpext, 0, sizeof(*mpext));
d9ca1de8 1341 mpext->data_seq = data_seq;
6d0060f6 1342 mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq;
f70cad10 1343 mpext->data_len = copy;
6d0060f6
MM		 1344 mpext->use_map = 1;
1345 mpext->dsn64 = 1;
1346
1347 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d",
1348 mpext->data_seq, mpext->subflow_seq, mpext->data_len,
1349 mpext->dsn64);
1350
6f8a612a 1351 if (zero_window_probe) {
f70cad10 1352 mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
6f8a612a 1353 mpext->frozen = 1;
d0cc2987 1354 if (READ_ONCE(msk->csum_enabled))
f70cad10 1355 mptcp_update_data_checksum(skb, copy);
6f8a612a 1356 tcp_push_pending_frames(ssk);
d0cc2987 1357 return 0;
6f8a612a 1358 }
57040755 1359out:
d0cc2987 1360 if (READ_ONCE(msk->csum_enabled))
f70cad10 1361 mptcp_update_data_checksum(skb, copy);
1e39e5a3
GT		 1362 if (mptcp_subflow_ctx(ssk)->send_infinite_map)
1363 mptcp_update_infinite_map(msk, ssk, mpext);
0eb4e7ee 1364 trace_mptcp_sendmsg_frag(mpext);
f70cad10
PA		 1365 mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
1366 return copy;
6d0060f6
MM		 1367}
1368
d5f49190
PA		 1369#define MPTCP_SEND_BURST_SIZE ((1 << 16) - \
1370 sizeof(struct tcphdr) - \
1371 MAX_TCP_OPTION_SPACE - \
1372 sizeof(struct ipv6hdr) - \
1373 sizeof(struct frag_hdr))
1374
1375struct subflow_send_info {
1376 struct sock *ssk;
3ce0852c 1377 u64 linger_time;
d5f49190
PA		 1378};
1379
ff5a0b42
PA		 1380void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow)
1381{
1382 if (!subflow->stale)
1383 return;
1384
1385 subflow->stale = 0;
fc1b4e3b 1386 MPTCP_INC_STATS(sock_net(mptcp_subflow_tcp_sock(subflow)), MPTCP_MIB_SUBFLOWRECOVER);
ff5a0b42
PA		 1387}
1388
1389bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
1390{
1391 if (unlikely(subflow->stale)) {
1392 u32 rcv_tstamp = READ_ONCE(tcp_sk(mptcp_subflow_tcp_sock(subflow))->rcv_tstamp);
1393
1394 if (subflow->stale_rcv_tstamp == rcv_tstamp)
1395 return false;
1396
1397 mptcp_subflow_set_active(subflow);
1398 }
1399 return __mptcp_subflow_active(subflow);
1400}
1401
3ce0852c
PA		 1402#define SSK_MODE_ACTIVE 0
1403#define SSK_MODE_BACKUP 1
1404#define SSK_MODE_MAX 2
1405
33d41c9c
PA		 1406/* implement the mptcp packet scheduler;
1407 * returns the subflow that will transmit the next DSS
1408 * additionally updates the rtx timeout
1409 */
07336a87 1410struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
f296234c 1411{
3ce0852c 1412 struct subflow_send_info send_info[SSK_MODE_MAX];
f296234c 1413 struct mptcp_subflow_context *subflow;
33d41c9c 1414 struct sock *sk = (struct sock *)msk;
3ce0852c 1415 u32 pace, burst, wmem;
d5f49190
PA		 1416 int i, nr_active = 0;
1417 struct sock *ssk;
3ce0852c 1418 u64 linger_time;
33d41c9c 1419 long tout = 0;
f296234c 1420
d5f49190 1421 /* pick the subflow with the lower wmem/wspace ratio */
3ce0852c 1422 for (i = 0; i < SSK_MODE_MAX; ++i) {
d5f49190 1423 send_info[i].ssk = NULL;
3ce0852c 1424 send_info[i].linger_time = -1;
d5f49190 1425 }
3ce0852c 1426
d5f49190 1427 mptcp_for_each_subflow(msk, subflow) {
e10a9892 1428 trace_mptcp_subflow_get_send(subflow);
d5f49190
PA		 1429 ssk = mptcp_subflow_tcp_sock(subflow);
1430 if (!mptcp_subflow_active(subflow))
1431 continue;
1432
33d41c9c 1433 tout = max(tout, mptcp_timeout_from_subflow(subflow));
d5f49190 1434 nr_active += !subflow->backup;
3ce0852c
PA		 1435 pace = subflow->avg_pacing_rate;
1436 if (unlikely(!pace)) {
1437 /* init pacing rate from socket */
1438 subflow->avg_pacing_rate = READ_ONCE(ssk->sk_pacing_rate);
1439 pace = subflow->avg_pacing_rate;
1440 if (!pace)
1441 continue;
1442 }
f296234c 1443
3ce0852c
PA		 1444 linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace);
1445 if (linger_time < send_info[subflow->backup].linger_time) {
d5f49190 1446 send_info[subflow->backup].ssk = ssk;
3ce0852c 1447 send_info[subflow->backup].linger_time = linger_time;
d5f49190 1448 }
f296234c 1449 }
33d41c9c 1450 __mptcp_set_timeout(sk, tout);
f296234c 1451
d5f49190
PA		 1452 /* pick the best backup if no other subflow is active */
1453 if (!nr_active)
3ce0852c
PA		 1454 send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk;
1455
1456 /* According to the blest algorithm, to avoid HoL blocking for the
1457 * faster flow, we need to:
1458 * - estimate the faster flow linger time
1459 * - use the above to estimate the amount of byte transferred
1460 * by the faster flow
1461 * - check that the amount of queued data is greter than the above,
1462 * otherwise do not use the picked, slower, subflow
1463 * We select the subflow with the shorter estimated time to flush
1464 * the queued mem, which basically ensure the above. We just need
1465 * to check that subflow has a non empty cwin.
1466 */
1467 ssk = send_info[SSK_MODE_ACTIVE].ssk;
b713d006 1468 if (!ssk || !sk_stream_memory_free(ssk))
3ce0852c 1469 return NULL;
5cf92bba 1470
b713d006 1471 burst = min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
3ce0852c 1472 wmem = READ_ONCE(ssk->sk_wmem_queued);
ebc1e08f 1473 if (!burst)
b713d006 1474 return ssk;
b713d006 1475
3ce0852c
PA		 1476 subflow = mptcp_subflow_ctx(ssk);
1477 subflow->avg_pacing_rate = div_u64((u64)subflow->avg_pacing_rate * wmem +
1478 READ_ONCE(ssk->sk_pacing_rate) * burst,
1479 burst + wmem);
3ce0852c
PA		 1480 msk->snd_burst = burst;
1481 return ssk;
f296234c
PK		 1482}
1483
b8e0def3 1484static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info)
d9ca1de8 1485{
d9ca1de8
PA		 1486 tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal);
1487 release_sock(ssk);
1488}
1489
0d199e43
FW		 1490static void mptcp_update_post_push(struct mptcp_sock *msk,
1491 struct mptcp_data_frag *dfrag,
1492 u32 sent)
1493{
1494 u64 snd_nxt_new = dfrag->data_seq;
1495
1496 dfrag->already_sent += sent;
1497
1498 msk->snd_burst -= sent;
0d199e43
FW		 1499
1500 snd_nxt_new += dfrag->already_sent;
1501
1502 /* snd_nxt_new can be smaller than snd_nxt in case mptcp
1503 * is recovering after a failover. In that event, this re-sends
1504 * old segments.
1505 *
1506 * Thus compute snd_nxt_new candidate based on
1507 * the dfrag->data_seq that was sent and the data
1508 * that has been handed to the subflow for transmission
1509 * and skip update in case it was old dfrag.
1510 */
38967f42
PA		 1511 if (likely(after64(snd_nxt_new, msk->snd_nxt))) {
1512 msk->bytes_sent += snd_nxt_new - msk->snd_nxt;
0d199e43 1513 msk->snd_nxt = snd_nxt_new;
38967f42 1514 }
0d199e43
FW		 1515}
1516
8b38217a 1517void mptcp_check_and_set_pending(struct sock *sk)
3241a9c0 1518{
e9d09bac
PA		 1519 if (mptcp_send_head(sk))
1520 mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING);
3241a9c0
FW		 1521}
1522
c5b4297d
GT		 1523static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
1524 struct mptcp_sendmsg_info *info)
f870fa0b
MM		 1525{
1526 struct mptcp_sock *msk = mptcp_sk(sk);
d9ca1de8 1527 struct mptcp_data_frag *dfrag;
c5b4297d 1528 int len, copied = 0, err = 0;
d9ca1de8
PA		 1529
1530 while ((dfrag = mptcp_send_head(sk))) {
c5b4297d
GT		 1531 info->sent = dfrag->already_sent;
1532 info->limit = dfrag->data_len;
d9ca1de8
PA		 1533 len = dfrag->data_len - dfrag->already_sent;
1534 while (len > 0) {
1535 int ret = 0;
1536
c5b4297d 1537 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, info);
d9ca1de8 1538 if (ret <= 0) {
c5b4297d 1539 err = copied ? : ret;
d9ca1de8
PA		 1540 goto out;
1541 }
1542
c5b4297d
GT		 1543 info->sent += ret;
1544 copied += ret;
d9ca1de8 1545 len -= ret;
0d199e43
FW		 1546
1547 mptcp_update_post_push(msk, dfrag, ret);
d9ca1de8
PA		 1548 }
1549 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
c5b4297d
GT		 1550
1551 if (msk->snd_burst <= 0 ||
1552 !sk_stream_memory_free(ssk) ||
1553 !mptcp_subflow_active(mptcp_subflow_ctx(ssk))) {
1554 err = copied;
1555 goto out;
1556 }
1557 mptcp_set_timeout(sk);
1558 }
1559 err = copied;
1560
1561out:
1562 return err;
1563}
1564
1565void __mptcp_push_pending(struct sock *sk, unsigned int flags)
1566{
1567 struct sock *prev_ssk = NULL, *ssk = NULL;
1568 struct mptcp_sock *msk = mptcp_sk(sk);
1569 struct mptcp_sendmsg_info info = {
1570 .flags = flags,
1571 };
1572 bool do_check_data_fin = false;
0fa1b378 1573 int push_count = 1;
c5b4297d 1574
0fa1b378
GT		 1575 while (mptcp_send_head(sk) && (push_count > 0)) {
1576 struct mptcp_subflow_context *subflow;
c5b4297d
GT		 1577 int ret = 0;
1578
0fa1b378
GT		 1579 if (mptcp_sched_get_send(msk))
1580 break;
c5b4297d 1581
0fa1b378
GT		 1582 push_count = 0;
1583
1584 mptcp_for_each_subflow(msk, subflow) {
1585 if (READ_ONCE(subflow->scheduled)) {
1586 mptcp_subflow_set_scheduled(subflow, false);
1587
1588 prev_ssk = ssk;
1589 ssk = mptcp_subflow_tcp_sock(subflow);
1590 if (ssk != prev_ssk) {
1591 /* First check. If the ssk has changed since
1592 * the last round, release prev_ssk
1593 */
1594 if (prev_ssk)
1595 mptcp_push_release(prev_ssk, &info);
1596
1597 /* Need to lock the new subflow only if different
1598 * from the previous one, otherwise we are still
1599 * helding the relevant lock
1600 */
1601 lock_sock(ssk);
1602 }
1603
1604 push_count++;
1605
1606 ret = __subflow_push_pending(sk, ssk, &info);
1607 if (ret <= 0) {
1608 if (ret != -EAGAIN ||
1609 (1 << ssk->sk_state) &
1610 (TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSE))
1611 push_count--;
1612 continue;
1613 }
1614 do_check_data_fin = true;
1615 }
c5b4297d 1616 }
d9ca1de8
PA		 1617 }
1618
1619 /* at this point we held the socket lock for the last subflow we used */
1620 if (ssk)
b8e0def3 1621 mptcp_push_release(ssk, &info);
d9ca1de8 1622
33d41c9c 1623 /* ensure the rtx timer is running */
f6909dc1
PA		 1624 if (!mptcp_rtx_timer_pending(sk))
1625 mptcp_reset_rtx_timer(sk);
0522b424 1626 if (do_check_data_fin)
81c1d029 1627 mptcp_check_send_data_fin(sk);
d9ca1de8
PA		 1628}
1629
73a0052a 1630static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool first)
6e628cd3
PA		 1631{
1632 struct mptcp_sock *msk = mptcp_sk(sk);
1094c6fe
PA		 1633 struct mptcp_sendmsg_info info = {
1634 .data_lock_held = true,
1635 };
0fa1b378 1636 bool keep_pushing = true;
b19bc294 1637 struct sock *xmit_ssk;
c5b4297d 1638 int copied = 0;
6e628cd3
PA		 1639
1640 info.flags = 0;
0fa1b378
GT		 1641 while (mptcp_send_head(sk) && keep_pushing) {
1642 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
c5b4297d 1643 int ret = 0;
b19bc294 1644
c5b4297d
GT		 1645 /* check for a different subflow usage only after
1646 * spooling the first chunk of data
1647 */
0fa1b378
GT		 1648 if (first) {
1649 mptcp_subflow_set_scheduled(subflow, false);
1650 ret = __subflow_push_pending(sk, ssk, &info);
1651 first = false;
1652 if (ret <= 0)
1653 break;
1654 copied += ret;
1655 continue;
1656 }
1657
1658 if (mptcp_sched_get_send(msk))
c5b4297d 1659 goto out;
0fa1b378
GT		 1660
1661 if (READ_ONCE(subflow->scheduled)) {
1662 mptcp_subflow_set_scheduled(subflow, false);
1663 ret = __subflow_push_pending(sk, ssk, &info);
1664 if (ret <= 0)
1665 keep_pushing = false;
1666 copied += ret;
6e628cd3 1667 }
c5b4297d 1668
0fa1b378
GT		 1669 mptcp_for_each_subflow(msk, subflow) {
1670 if (READ_ONCE(subflow->scheduled)) {
1671 xmit_ssk = mptcp_subflow_tcp_sock(subflow);
1672 if (xmit_ssk != ssk) {
1673 mptcp_subflow_delegate(subflow,
1674 MPTCP_DELEGATE_SEND);
1675 keep_pushing = false;
1676 }
1677 }
1678 }
6e628cd3
PA		 1679 }
1680
1681out:
1682 /* __mptcp_alloc_tx_skb could have released some wmem and we are
1683 * not going to flush it via release_sock()
1684 */
6e628cd3 1685 if (copied) {
6e628cd3
PA		 1686 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
1687 info.size_goal);
f6909dc1
PA		 1688 if (!mptcp_rtx_timer_pending(sk))
1689 mptcp_reset_rtx_timer(sk);
d09d818e 1690
6e628cd3
PA		 1691 if (msk->snd_data_fin_enable &&
1692 msk->snd_nxt + 1 == msk->write_seq)
1693 mptcp_schedule_work(sk);
1694 }
1695}
1696
5cf92bba
PA		 1697static void mptcp_set_nospace(struct sock *sk)
1698{
1699 /* enable autotune */
1700 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1701
1702 /* will be cleared on avail space */
1703 set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags);
1704}
1705
7d803344
PA		 1706static int mptcp_disconnect(struct sock *sk, int flags);
1707
a2702a07 1708static int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
fa9e5746
PA		 1709 size_t len, int *copied_syn)
1710{
1711 unsigned int saved_flags = msg->msg_flags;
1712 struct mptcp_sock *msk = mptcp_sk(sk);
a2702a07 1713 struct sock *ssk;
fa9e5746
PA		 1714 int ret;
1715
a2702a07
PA		 1716 /* on flags based fastopen the mptcp is supposed to create the
1717 * first subflow right now. Otherwise we are in the defer_connect
1718 * path, and the first subflow must be already present.
1719 * Since the defer_connect flag is cleared after the first succsful
1720 * fastopen attempt, no need to check for additional subflow status.
1721 */
ddb1a072 1722 if (msg->msg_flags & MSG_FASTOPEN) {
3f326a82
PA		 1723 ssk = __mptcp_nmpc_sk(msk);
1724 if (IS_ERR(ssk))
1725 return PTR_ERR(ssk);
ddb1a072 1726 }
a2702a07
PA		 1727 if (!msk->first)
1728 return -EINVAL;
1729
1730 ssk = msk->first;
1731
fa9e5746
PA		 1732 lock_sock(ssk);
1733 msg->msg_flags |= MSG_DONTWAIT;
7d803344 1734 msk->fastopening = 1;
fa9e5746 1735 ret = tcp_sendmsg_fastopen(ssk, msg, copied_syn, len, NULL);
7d803344 1736 msk->fastopening = 0;
fa9e5746
PA		 1737 msg->msg_flags = saved_flags;
1738 release_sock(ssk);
1739
1740 /* do the blocking bits of inet_stream_connect outside the ssk socket lock */
1741 if (ret == -EINPROGRESS && !(msg->msg_flags & MSG_DONTWAIT)) {
1742 ret = __inet_stream_connect(sk->sk_socket, msg->msg_name,
1743 msg->msg_namelen, msg->msg_flags, 1);
1744
1745 /* Keep the same behaviour of plain TCP: zero the copied bytes in
1746 * case of any error, except timeout or signal
1747 */
1748 if (ret && ret != -EINPROGRESS && ret != -ERESTARTSYS && ret != -EINTR)
1749 *copied_syn = 0;
7d803344 1750 } else if (ret && ret != -EINPROGRESS) {
c2b2ae39
PA		 1751 /* The disconnect() op called by tcp_sendmsg_fastopen()/
1752 * __inet_stream_connect() can fail, due to looking check,
1753 * see mptcp_disconnect().
1754 * Attempt it again outside the problematic scope.
1755 */
1756 if (!mptcp_disconnect(sk, 0))
1757 sk->sk_socket->state = SS_UNCONNECTED;
fa9e5746 1758 }
08e39c0d 1759 inet_clear_bit(DEFER_CONNECT, sk);
fa9e5746
PA		 1760
1761 return ret;
1762}
1763
d9ca1de8
PA		 1764static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1765{
1766 struct mptcp_sock *msk = mptcp_sk(sk);
17091708 1767 struct page_frag *pfrag;
6d0060f6 1768 size_t copied = 0;
caf971df 1769 int ret = 0;
6d0060f6 1770 long timeo;
f870fa0b 1771
987858e5 1772 /* silently ignore everything else */
1e777f39 1773 msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_FASTOPEN;
987858e5 1774
6511882c 1775 lock_sock(sk);
1954b860 1776
08e39c0d
ED		 1777 if (unlikely(inet_test_bit(DEFER_CONNECT, sk) ||
1778 msg->msg_flags & MSG_FASTOPEN)) {
d98a82a6
DS		 1779 int copied_syn = 0;
1780
a2702a07 1781 ret = mptcp_sendmsg_fastopen(sk, msg, len, &copied_syn);
d98a82a6 1782 copied += copied_syn;
fa9e5746 1783 if (ret == -EINPROGRESS && copied_syn > 0)
d98a82a6 1784 goto out;
fa9e5746 1785 else if (ret)
69800e51 1786 goto do_error;
d98a82a6
DS		 1787 }
1788
1954b860
MM		 1789 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1790
1791 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
1792 ret = sk_stream_wait_connect(sk, &timeo);
1793 if (ret)
69800e51 1794 goto do_error;
1954b860
MM		 1795 }
1796
69800e51
PA		 1797 ret = -EPIPE;
1798 if (unlikely(sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)))
1799 goto do_error;
1800
17091708 1801 pfrag = sk_page_frag(sk);
18b683bf 1802
d9ca1de8 1803 while (msg_data_left(msg)) {
724cfd2e 1804 int total_ts, frag_truesize = 0;
d9ca1de8 1805 struct mptcp_data_frag *dfrag;
d9ca1de8
PA		 1806 bool dfrag_collapsed;
1807 size_t psize, offset;
18b683bf 1808
d9ca1de8
PA		 1809 /* reuse tail pfrag, if possible, or carve a new one from the
1810 * page allocator
1811 */
1812 dfrag = mptcp_pending_tail(sk);
1813 dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag);
1814 if (!dfrag_collapsed) {
6e628cd3
PA		 1815 if (!sk_stream_memory_free(sk))
1816 goto wait_for_memory;
1817
d9ca1de8
PA		 1818 if (!mptcp_page_frag_refill(sk, pfrag))
1819 goto wait_for_memory;
1820
1821 dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset);
1822 frag_truesize = dfrag->overhead;
72511aab 1823 }
6d0060f6 1824
d9ca1de8
PA		 1825 /* we do not bound vs wspace, to allow a single packet.
1826 * memory accounting will prevent execessive memory usage
1827 * anyway
d5f49190 1828 */
d9ca1de8
PA		 1829 offset = dfrag->offset + dfrag->data_len;
1830 psize = pfrag->size - offset;
1831 psize = min_t(size_t, psize, msg_data_left(msg));
724cfd2e 1832 total_ts = psize + frag_truesize;
d9ca1de8 1833
6511882c 1834 if (!sk_wmem_schedule(sk, total_ts))
724cfd2e 1835 goto wait_for_memory;
724cfd2e 1836
d9ca1de8
PA		 1837 if (copy_page_from_iter(dfrag->page, offset, psize,
1838 &msg->msg_iter) != psize) {
1839 ret = -EFAULT;
69800e51 1840 goto do_error;
72511aab
FW		 1841 }
1842
d9ca1de8 1843 /* data successfully copied into the write queue */
5e6300e7 1844 sk_forward_alloc_add(sk, -total_ts);
d9ca1de8
PA		 1845 copied += psize;
1846 dfrag->data_len += psize;
1847 frag_truesize += psize;
1848 pfrag->offset += frag_truesize;
1849 WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
1850
1851 /* charge data on mptcp pending queue to the msk socket
1852 * Note: we charge such data both to sk and ssk
fb529e62 1853 */
d9ca1de8 1854 sk_wmem_queued_add(sk, frag_truesize);
d9ca1de8
PA		 1855 if (!dfrag_collapsed) {
1856 get_page(dfrag->page);
1857 list_add_tail(&dfrag->list, &msk->rtx_queue);
1858 if (!msk->first_pending)
1859 WRITE_ONCE(msk->first_pending, dfrag);
fb529e62 1860 }
e4b61351 1861 pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk,
d9ca1de8
PA		 1862 dfrag->data_seq, dfrag->data_len, dfrag->already_sent,
1863 !dfrag_collapsed);
6d0060f6 1864
d9ca1de8 1865 continue;
b51f9b80 1866
d9ca1de8 1867wait_for_memory:
5cf92bba 1868 mptcp_set_nospace(sk);
c2e6048f 1869 __mptcp_push_pending(sk, msg->msg_flags);
d9ca1de8
PA		 1870 ret = sk_stream_wait_memory(sk, &timeo);
1871 if (ret)
69800e51 1872 goto do_error;
57040755 1873 }
6d0060f6 1874
13e16037 1875 if (copied)
c2e6048f 1876 __mptcp_push_pending(sk, msg->msg_flags);
d9ca1de8 1877
1954b860 1878out:
cec37a6e 1879 release_sock(sk);
69800e51
PA		 1880 return copied;
1881
1882do_error:
1883 if (copied)
1884 goto out;
1885
1886 copied = sk_stream_error(sk, msg->msg_flags, ret);
1887 goto out;
f870fa0b
MM		 1888}
1889
6771bfd9
FW		 1890static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk,
1891 struct msghdr *msg,
b7f653b2
FW		 1892 size_t len, int flags,
1893 struct scm_timestamping_internal *tss,
1894 int *cmsg_flags)
6771bfd9 1895{
ca4fb892 1896 struct sk_buff *skb, *tmp;
6771bfd9
FW		 1897 int copied = 0;
1898
ca4fb892 1899 skb_queue_walk_safe(&msk->receive_queue, skb, tmp) {
6771bfd9
FW		 1900 u32 offset = MPTCP_SKB_CB(skb)->offset;
1901 u32 data_len = skb->len - offset;
1902 u32 count = min_t(size_t, len - copied, data_len);
1903 int err;
1904
d976092c
PA		 1905 if (!(flags & MSG_TRUNC)) {
1906 err = skb_copy_datagram_msg(skb, offset, msg, count);
1907 if (unlikely(err < 0)) {
1908 if (!copied)
1909 return err;
1910 break;
1911 }
6771bfd9
FW		 1912 }
1913
b7f653b2
FW		 1914 if (MPTCP_SKB_CB(skb)->has_rxtstamp) {
1915 tcp_update_recv_tstamps(skb, tss);
1916 *cmsg_flags |= MPTCP_CMSG_TS;
1917 }
1918
6771bfd9
FW		 1919 copied += count;
1920
1921 if (count < data_len) {
2c9e7765 1922 if (!(flags & MSG_PEEK)) {
ca4fb892 1923 MPTCP_SKB_CB(skb)->offset += count;
2c9e7765
FW		 1924 MPTCP_SKB_CB(skb)->map_seq += count;
1925 }
6771bfd9
FW		 1926 break;
1927 }
1928
ca4fb892
YL		 1929 if (!(flags & MSG_PEEK)) {
1930 /* we will bulk release the skb memory later */
1931 skb->destructor = NULL;
ce599c51 1932 WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize);
ca4fb892
YL		 1933 __skb_unlink(skb, &msk->receive_queue);
1934 __kfree_skb(skb);
1935 }
6771bfd9
FW		 1936
1937 if (copied >= len)
1938 break;
1939 }
1940
1941 return copied;
1942}
1943
a6b118fe
FW		 1944/* receive buffer autotuning. See tcp_rcv_space_adjust for more information.
1945 *
1946 * Only difference: Use highest rtt estimate of the subflows in use.
1947 */
1948static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
1949{
1950 struct mptcp_subflow_context *subflow;
1951 struct sock *sk = (struct sock *)msk;
b8dc6d6c 1952 u8 scaling_ratio = U8_MAX;
a6b118fe
FW		 1953 u32 time, advmss = 1;
1954 u64 rtt_us, mstamp;
1955
109cdeb8 1956 msk_owned_by_me(msk);
a6b118fe
FW		 1957
1958 if (copied <= 0)
1959 return;
1960
1961 msk->rcvq_space.copied += copied;
1962
1963 mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC);
1964 time = tcp_stamp_us_delta(mstamp, msk->rcvq_space.time);
1965
1966 rtt_us = msk->rcvq_space.rtt_us;
1967 if (rtt_us && time < (rtt_us >> 3))
1968 return;
1969
1970 rtt_us = 0;
1971 mptcp_for_each_subflow(msk, subflow) {
1972 const struct tcp_sock *tp;
1973 u64 sf_rtt_us;
1974 u32 sf_advmss;
1975
1976 tp = tcp_sk(mptcp_subflow_tcp_sock(subflow));
1977
1978 sf_rtt_us = READ_ONCE(tp->rcv_rtt_est.rtt_us);
1979 sf_advmss = READ_ONCE(tp->advmss);
1980
1981 rtt_us = max(sf_rtt_us, rtt_us);
1982 advmss = max(sf_advmss, advmss);
b8dc6d6c 1983 scaling_ratio = min(tp->scaling_ratio, scaling_ratio);
a6b118fe
FW		 1984 }
1985
1986 msk->rcvq_space.rtt_us = rtt_us;
b8dc6d6c 1987 msk->scaling_ratio = scaling_ratio;
a6b118fe
FW		 1988 if (time < (rtt_us >> 3) || rtt_us == 0)
1989 return;
1990
1991 if (msk->rcvq_space.copied <= msk->rcvq_space.space)
1992 goto new_measure;
1993
78047648 1994 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) &&
a6b118fe 1995 !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
a6b118fe 1996 u64 rcvwin, grow;
b8dc6d6c 1997 int rcvbuf;
a6b118fe
FW		 1998
1999 rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss;
2000
2001 grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space);
2002
2003 do_div(grow, msk->rcvq_space.space);
2004 rcvwin += (grow << 1);
2005
b8dc6d6c 2006 rcvbuf = min_t(u64, __tcp_space_from_win(scaling_ratio, rcvwin),
02739545 2007 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2]));
a6b118fe
FW		 2008
2009 if (rcvbuf > sk->sk_rcvbuf) {
2010 u32 window_clamp;
2011
b8dc6d6c 2012 window_clamp = __tcp_win_from_space(scaling_ratio, rcvbuf);
a6b118fe
FW		 2013 WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
2014
2015 /* Make subflows follow along. If we do not do this, we
2016 * get drops at subflow level if skbs can't be moved to
2017 * the mptcp rx queue fast enough (announced rcv_win can
2018 * exceed ssk->sk_rcvbuf).
2019 */
2020 mptcp_for_each_subflow(msk, subflow) {
2021 struct sock *ssk;
c76c6956 2022 bool slow;
a6b118fe
FW		 2023
2024 ssk = mptcp_subflow_tcp_sock(subflow);
c76c6956 2025 slow = lock_sock_fast(ssk);
a6b118fe
FW		 2026 WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf);
2027 tcp_sk(ssk)->window_clamp = window_clamp;
c76c6956
PA		 2028 tcp_cleanup_rbuf(ssk, 1);
2029 unlock_sock_fast(ssk, slow);
a6b118fe
FW		 2030 }
2031 }
2032 }
2033
2034 msk->rcvq_space.space = msk->rcvq_space.copied;
2035new_measure:
2036 msk->rcvq_space.copied = 0;
2037 msk->rcvq_space.time = mstamp;
2038}
2039
87952603
PA		 2040static void __mptcp_update_rmem(struct sock *sk)
2041{
2042 struct mptcp_sock *msk = mptcp_sk(sk);
2043
2044 if (!msk->rmem_released)
2045 return;
2046
2047 atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc);
6511882c 2048 mptcp_rmem_uncharge(sk, msk->rmem_released);
ce599c51 2049 WRITE_ONCE(msk->rmem_released, 0);
87952603
PA		 2050}
2051
2052static void __mptcp_splice_receive_queue(struct sock *sk)
2053{
2054 struct mptcp_sock *msk = mptcp_sk(sk);
2055
2056 skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue);
2057}
2058
e3859603 2059static bool __mptcp_move_skbs(struct mptcp_sock *msk)
6771bfd9 2060{
87952603 2061 struct sock *sk = (struct sock *)msk;
6771bfd9 2062 unsigned int moved = 0;
87952603 2063 bool ret, done;
d5f49190 2064
6771bfd9
FW		 2065 do {
2066 struct sock *ssk = mptcp_subflow_recv_lookup(msk);
65f49fe7 2067 bool slowpath;
6771bfd9 2068
87952603
PA		 2069 /* we can have data pending in the subflows only if the msk
2070 * receive buffer was full at subflow_data_ready() time,
2071 * that is an unlikely slow path.
2072 */
2073 if (likely(!ssk))
6771bfd9
FW		 2074 break;
2075
65f49fe7 2076 slowpath = lock_sock_fast(ssk);
87952603 2077 mptcp_data_lock(sk);
e3859603 2078 __mptcp_update_rmem(sk);
6771bfd9 2079 done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
87952603 2080 mptcp_data_unlock(sk);
499ada50
PA		 2081
2082 if (unlikely(ssk->sk_err))
2083 __mptcp_error_report(sk);
65f49fe7 2084 unlock_sock_fast(ssk, slowpath);
6771bfd9
FW		 2085 } while (!done);
2086
87952603
PA		 2087 /* acquire the data lock only if some input data is pending */
2088 ret = moved > 0;
2089 if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) ||
2090 !skb_queue_empty_lockless(&sk->sk_receive_queue)) {
2091 mptcp_data_lock(sk);
2092 __mptcp_update_rmem(sk);
2093 ret |= __mptcp_ofo_queue(msk);
2094 __mptcp_splice_receive_queue(sk);
2095 mptcp_data_unlock(sk);
ab174ad8 2096 }
87952603
PA		 2097 if (ret)
2098 mptcp_check_data_fin((struct sock *)msk);
2099 return !skb_queue_empty(&msk->receive_queue);
6771bfd9
FW		 2100}
2101
2c9e7765
FW		 2102static unsigned int mptcp_inq_hint(const struct sock *sk)
2103{
2104 const struct mptcp_sock *msk = mptcp_sk(sk);
2105 const struct sk_buff *skb;
2106
2107 skb = skb_peek(&msk->receive_queue);
2108 if (skb) {
2109 u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq;
2110
2111 if (hint_val >= INT_MAX)
2112 return INT_MAX;
2113
2114 return (unsigned int)hint_val;
2115 }
2116
2117 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
2118 return 1;
2119
2120 return 0;
2121}
2122
f870fa0b 2123static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
ec095263 2124 int flags, int *addr_len)
f870fa0b
MM		 2125{
2126 struct mptcp_sock *msk = mptcp_sk(sk);
b7f653b2
FW		 2127 struct scm_timestamping_internal tss;
2128 int copied = 0, cmsg_flags = 0;
7a6a6cbc
PA		 2129 int target;
2130 long timeo;
f870fa0b 2131
cb9d80f4
PA		 2132 /* MSG_ERRQUEUE is really a no-op till we support IP_RECVERR */
2133 if (unlikely(flags & MSG_ERRQUEUE))
2134 return inet_recv_error(sk, msg, len, addr_len);
2135
6511882c 2136 lock_sock(sk);
fd897679
PA		 2137 if (unlikely(sk->sk_state == TCP_LISTEN)) {
2138 copied = -ENOTCONN;
2139 goto out_err;
2140 }
2141
ec095263 2142 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
7a6a6cbc
PA		 2143
2144 len = min_t(size_t, len, INT_MAX);
2145 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2146
2c9e7765
FW		 2147 if (unlikely(msk->recvmsg_inq))
2148 cmsg_flags = MPTCP_CMSG_INQ;
2149
05e3ecea 2150 while (copied < len) {
e3859603 2151 int bytes_read;
7a6a6cbc 2152
b7f653b2 2153 bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags);
6771bfd9
FW		 2154 if (unlikely(bytes_read < 0)) {
2155 if (!copied)
2156 copied = bytes_read;
2157 goto out_err;
2158 }
7a6a6cbc 2159
6771bfd9 2160 copied += bytes_read;
7a6a6cbc 2161
ea4ca586 2162 /* be sure to advertise window change */
e3859603
PA		 2163 mptcp_cleanup_rbuf(msk);
2164
2165 if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk))
2166 continue;
ea4ca586 2167
7a6a6cbc
PA		 2168 /* only the master socket status is relevant here. The exit
2169 * conditions mirror closely tcp_recvmsg()
2170 */
2171 if (copied >= target)
2172 break;
2173
2174 if (copied) {
2175 if (sk->sk_err ||
2176 sk->sk_state == TCP_CLOSE ||
2177 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2178 !timeo ||
2179 signal_pending(current))
2180 break;
2181 } else {
2182 if (sk->sk_err) {
2183 copied = sock_error(sk);
2184 break;
2185 }
2186
87952603
PA		 2187 if (sk->sk_shutdown & RCV_SHUTDOWN) {
2188 /* race breaker: the shutdown could be after the
2189 * previous receive queue check
2190 */
e3859603 2191 if (__mptcp_move_skbs(msk))
87952603 2192 continue;
7a6a6cbc 2193 break;
87952603 2194 }
7a6a6cbc
PA		 2195
2196 if (sk->sk_state == TCP_CLOSE) {
2197 copied = -ENOTCONN;
2198 break;
2199 }
2200
2201 if (!timeo) {
2202 copied = -EAGAIN;
2203 break;
2204 }
2205
2206 if (signal_pending(current)) {
2207 copied = sock_intr_errno(timeo);
2208 break;
2209 }
2210 }
2211
2212 pr_debug("block timeout %ld", timeo);
612f71d7 2213 sk_wait_data(sk, &timeo, NULL);
7a6a6cbc 2214 }
3c90e377 2215
6771bfd9 2216out_err:
b7f653b2
FW		 2217 if (cmsg_flags && copied >= 0) {
2218 if (cmsg_flags & MPTCP_CMSG_TS)
2219 tcp_recv_timestamp(msg, sk, &tss);
2c9e7765
FW		 2220
2221 if (cmsg_flags & MPTCP_CMSG_INQ) {
2222 unsigned int inq = mptcp_inq_hint(sk);
2223
2224 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);
2225 }
b7f653b2
FW		 2226 }
2227
612f71d7
PA		 2228 pr_debug("msk=%p rx queue empty=%d:%d copied=%d",
2229 msk, skb_queue_empty_lockless(&sk->sk_receive_queue),
2230 skb_queue_empty(&msk->receive_queue), copied);
ca4fb892
YL		 2231 if (!(flags & MSG_PEEK))
2232 mptcp_rcv_space_adjust(msk, copied);
a6b118fe 2233
7a6a6cbc 2234 release_sock(sk);
cec37a6e
PK		 2235 return copied;
2236}
2237
b51f9b80
PA		 2238static void mptcp_retransmit_timer(struct timer_list *t)
2239{
2240 struct inet_connection_sock *icsk = from_timer(icsk, t,
2241 icsk_retransmit_timer);
2242 struct sock *sk = &icsk->icsk_inet.sk;
2d6f5a2b 2243 struct mptcp_sock *msk = mptcp_sk(sk);
b51f9b80
PA		 2244
2245 bh_lock_sock(sk);
2246 if (!sock_owned_by_user(sk)) {
2d6f5a2b
PA		 2247 /* we need a process context to retransmit */
2248 if (!test_and_set_bit(MPTCP_WORK_RTX, &msk->flags))
2249 mptcp_schedule_work(sk);
b51f9b80
PA		 2250 } else {
2251 /* delegate our work to tcp_release_cb() */
e9d09bac 2252 __set_bit(MPTCP_RETRANSMIT, &msk->cb_flags);
b51f9b80
PA		 2253 }
2254 bh_unlock_sock(sk);
2255 sock_put(sk);
2256}
2257
f6909dc1 2258static void mptcp_tout_timer(struct timer_list *t)
e16163b6
PA		 2259{
2260 struct sock *sk = from_timer(sk, t, sk_timer);
2261
2262 mptcp_schedule_work(sk);
b6d69fc8 2263 sock_put(sk);
e16163b6
PA		 2264}
2265
3b1d6210
PA		 2266/* Find an idle subflow. Return NULL if there is unacked data at tcp
2267 * level.
2268 *
2269 * A backup subflow is returned only if that is the only kind available.
2270 */
07336a87 2271struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
3b1d6210 2272{
71b7dec2 2273 struct sock *backup = NULL, *pick = NULL;
3b1d6210 2274 struct mptcp_subflow_context *subflow;
71b7dec2 2275 int min_stale_count = INT_MAX;
3b1d6210 2276
3b1d6210
PA		 2277 mptcp_for_each_subflow(msk, subflow) {
2278 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2279
ff5a0b42 2280 if (!__mptcp_subflow_active(subflow))
d5f49190
PA		 2281 continue;
2282
71b7dec2
PA		 2283 /* still data outstanding at TCP level? skip this */
2284 if (!tcp_rtx_and_write_queues_empty(ssk)) {
2285 mptcp_pm_subflow_chk_stale(msk, ssk);
2286 min_stale_count = min_t(int, min_stale_count, subflow->stale_count);
2287 continue;
860975c6 2288 }
3b1d6210
PA		 2289
2290 if (subflow->backup) {
2291 if (!backup)
2292 backup = ssk;
2293 continue;
2294 }
2295
71b7dec2
PA		 2296 if (!pick)
2297 pick = ssk;
3b1d6210
PA		 2298 }
2299
71b7dec2
PA		 2300 if (pick)
2301 return pick;
2302
2303 /* use backup only if there are no progresses anywhere */
2304 return min_stale_count > 1 ? backup : NULL;
3b1d6210
PA		 2305}
2306
1e1d9d6f
PA		 2307bool __mptcp_retransmit_pending_data(struct sock *sk)
2308{
2309 struct mptcp_data_frag *cur, *rtx_head;
2310 struct mptcp_sock *msk = mptcp_sk(sk);
2311
00df24f1 2312 if (__mptcp_check_fallback(msk))
1e1d9d6f
PA		 2313 return false;
2314
2315 if (tcp_rtx_and_write_queues_empty(sk))
2316 return false;
2317
2318 /* the closing socket has some data untransmitted and/or unacked:
2319 * some data in the mptcp rtx queue has not really xmitted yet.
2320 * keep it simple and re-inject the whole mptcp level rtx queue
2321 */
2322 mptcp_data_lock(sk);
2323 __mptcp_clean_una_wakeup(sk);
2324 rtx_head = mptcp_rtx_head(sk);
2325 if (!rtx_head) {
2326 mptcp_data_unlock(sk);
2327 return false;
2328 }
2329
0d199e43 2330 msk->recovery_snd_nxt = msk->snd_nxt;
1e1d9d6f
PA		 2331 msk->recovery = true;
2332 mptcp_data_unlock(sk);
2333
2334 msk->first_pending = rtx_head;
1e1d9d6f
PA		 2335 msk->snd_burst = 0;
2336
2337 /* be sure to clear the "sent status" on all re-injected fragments */
2338 list_for_each_entry(cur, &msk->rtx_queue, list) {
2339 if (!cur->already_sent)
2340 break;
2341 cur->already_sent = 0;
2342 }
2343
2344 return true;
2345}
2346
b29fcfb5
PA		 2347/* flags for __mptcp_close_ssk() */
2348#define MPTCP_CF_PUSH BIT(1)
2349#define MPTCP_CF_FASTCLOSE BIT(2)
2350
14c56686
GT		 2351/* be sure to send a reset only if the caller asked for it, also
2352 * clean completely the subflow status when the subflow reaches
2353 * TCP_CLOSE state
2354 */
2355static void __mptcp_subflow_disconnect(struct sock *ssk,
2356 struct mptcp_subflow_context *subflow,
2357 unsigned int flags)
2358{
2359 if (((1 << ssk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) ||
2360 (flags & MPTCP_CF_FASTCLOSE)) {
2361 /* The MPTCP code never wait on the subflow sockets, TCP-level
2362 * disconnect should never fail
2363 */
2364 WARN_ON_ONCE(tcp_disconnect(ssk, 0));
2365 mptcp_subflow_ctx_reset(subflow);
2366 } else {
2367 tcp_shutdown(ssk, SEND_SHUTDOWN);
2368 }
2369}
2370
cec37a6e
PK		 2371/* subflow sockets can be either outgoing (connect) or incoming
2372 * (accept).
2373 *
2374 * Outgoing subflows use in-kernel sockets.
2375 * Incoming subflows do not have their own 'struct socket' allocated,
2376 * so we need to use tcp_close() after detaching them from the mptcp
2377 * parent socket.
2378 */
a141e02e 2379static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
b29fcfb5
PA		 2380 struct mptcp_subflow_context *subflow,
2381 unsigned int flags)
cec37a6e 2382{
e0be4931 2383 struct mptcp_sock *msk = mptcp_sk(sk);
63740448
PA		 2384 bool dispose_it, need_push = false;
2385
2386 /* If the first subflow moved to a close state before accept, e.g. due
27e5ccc2
PA		 2387 * to an incoming reset or listener shutdown, the subflow socket is
2388 * already deleted by inet_child_forget() and the mptcp socket can't
2389 * survive too.
63740448 2390 */
27e5ccc2
PA		 2391 if (msk->in_accept_queue && msk->first == ssk &&
2392 (sock_flag(sk, SOCK_DEAD) || sock_flag(ssk, SOCK_DEAD))) {
63740448 2393 /* ensure later check in mptcp_worker() will dispose the msk */
27e5ccc2 2394 mptcp_set_close_tout(sk, tcp_jiffies32 - (TCP_TIMEWAIT_LEN + 1));
63740448
PA		 2395 sock_set_flag(sk, SOCK_DEAD);
2396 lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
2397 mptcp_subflow_drop_ctx(ssk);
2398 goto out_release;
2399 }
e0be4931 2400
39880bd8 2401 dispose_it = msk->free_first || ssk != msk->first;
b29fcfb5
PA		 2402 if (dispose_it)
2403 list_del(&subflow->node);
cec37a6e 2404
3f8b2667 2405 lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
e16163b6 2406
ff18f9ef 2407 if ((flags & MPTCP_CF_FASTCLOSE) && !__mptcp_check_fallback(msk)) {
14c56686 2408 /* be sure to force the tcp_close path
d21f8348
PA		 2409 * to generate the egress reset
2410 */
2411 ssk->sk_lingertime = 0;
2412 sock_set_flag(ssk, SOCK_LINGER);
b29fcfb5 2413 subflow->send_fastclose = 1;
d21f8348 2414 }
b29fcfb5
PA		 2415
2416 need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk);
2417 if (!dispose_it) {
14c56686 2418 __mptcp_subflow_disconnect(ssk, subflow, flags);
b29fcfb5
PA		 2419 release_sock(ssk);
2420
2421 goto out;
2422 }
2423
d7b1bfd0
PA		 2424 subflow->disposable = 1;
2425
e16163b6
PA		 2426 /* if ssk hit tcp_done(), tcp_cleanup_ulp() cleared the related ops
2427 * the ssk has been already destroyed, we just need to release the
2428 * reference owned by msk;
2429 */
2430 if (!inet_csk(ssk)->icsk_ulp_ops) {
b6985b9b 2431 WARN_ON_ONCE(!sock_flag(ssk, SOCK_DEAD));
e16163b6 2432 kfree_rcu(subflow, rcu);
cec37a6e 2433 } else {
d7b1bfd0 2434 /* otherwise tcp will dispose of the ssk and subflow ctx */
e16163b6
PA		 2435 __tcp_close(ssk, 0);
2436
2437 /* close acquired an extra ref */
2438 __sock_put(ssk);
cec37a6e 2439 }
63740448
PA		 2440
2441out_release:
9f1a9881 2442 __mptcp_subflow_error_report(sk, ssk);
e16163b6 2443 release_sock(ssk);
e16163b6
PA		 2444
2445 sock_put(ssk);
e0be4931 2446
c8fe62f0 2447 if (ssk == msk->first)
1b1b43ee 2448 WRITE_ONCE(msk->first, NULL);
c8fe62f0 2449
b29fcfb5 2450out:
1e1d9d6f
PA		 2451 if (need_push)
2452 __mptcp_push_pending(sk, 0);
27e5ccc2
PA		 2453
2454 /* Catch every 'all subflows closed' scenario, including peers silently
2455 * closing them, e.g. due to timeout.
2456 * For established sockets, allow an additional timeout before closing,
2457 * as the protocol can still create more subflows.
2458 */
2459 if (list_is_singular(&msk->conn_list) && msk->first &&
2460 inet_sk_state_load(msk->first) == TCP_CLOSE) {
2461 if (sk->sk_state != TCP_ESTABLISHED ||
2462 msk->in_accept_queue || sock_flag(sk, SOCK_DEAD)) {
2463 inet_sk_state_store(sk, TCP_CLOSE);
2464 mptcp_close_wake_up(sk);
2465 } else {
2466 mptcp_start_tout_timer(sk);
2467 }
2468 }
f870fa0b
MM		 2469}
2470
a141e02e
FW		 2471void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
2472 struct mptcp_subflow_context *subflow)
2473{
b911c97c
FW		 2474 if (sk->sk_state == TCP_ESTABLISHED)
2475 mptcp_event(MPTCP_EVENT_SUB_CLOSED, mptcp_sk(sk), ssk, GFP_KERNEL);
a88c9e49
PA		 2476
2477 /* subflow aborted before reaching the fully_established status
2478 * attempt the creation of the next subflow
2479 */
2480 mptcp_pm_subflow_check_next(mptcp_sk(sk), ssk, subflow);
2481
b29fcfb5 2482 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_PUSH);
a141e02e
FW		 2483}
2484
dc24f8b4
PA		 2485static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu)
2486{
2487 return 0;
2488}
2489
b6985b9b 2490static void __mptcp_close_subflow(struct sock *sk)
0e4f35d7
PA		 2491{
2492 struct mptcp_subflow_context *subflow, *tmp;
b6985b9b 2493 struct mptcp_sock *msk = mptcp_sk(sk);
0e4f35d7 2494
3abc05d9
FW		 2495 might_sleep();
2496
5efbf6f7 2497 mptcp_for_each_subflow_safe(msk, subflow, tmp) {
0e4f35d7
PA		 2498 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
2499
2500 if (inet_sk_state_load(ssk) != TCP_CLOSE)
2501 continue;
2502
40947e13
FW		 2503 /* 'subflow_data_ready' will re-sched once rx queue is empty */
2504 if (!skb_queue_empty_lockless(&ssk->sk_receive_queue))
2505 continue;
2506
b6985b9b
PA		 2507 mptcp_close_ssk(sk, ssk, subflow);
2508 }
2509
0e4f35d7
PA		 2510}
2511
27e5ccc2 2512static bool mptcp_close_tout_expired(const struct sock *sk)
e16163b6 2513{
27e5ccc2
PA		 2514 if (!inet_csk(sk)->icsk_mtup.probe_timestamp ||
2515 sk->sk_state == TCP_CLOSE)
2516 return false;
e16163b6 2517
27e5ccc2
PA		 2518 return time_after32(tcp_jiffies32,
2519 inet_csk(sk)->icsk_mtup.probe_timestamp + TCP_TIMEWAIT_LEN);
e16163b6
PA		 2520}
2521
50c504a2
FW		 2522static void mptcp_check_fastclose(struct mptcp_sock *msk)
2523{
2524 struct mptcp_subflow_context *subflow, *tmp;
80638684 2525 struct sock *sk = (struct sock *)msk;
50c504a2
FW		 2526
2527 if (likely(!READ_ONCE(msk->rcv_fastclose)))
2528 return;
2529
2530 mptcp_token_destroy(msk);
2531
5efbf6f7 2532 mptcp_for_each_subflow_safe(msk, subflow, tmp) {
50c504a2 2533 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
75e908c3 2534 bool slow;
50c504a2 2535
75e908c3 2536 slow = lock_sock_fast(tcp_sk);
50c504a2
FW		 2537 if (tcp_sk->sk_state != TCP_CLOSE) {
2538 tcp_send_active_reset(tcp_sk, GFP_ATOMIC);
2539 tcp_set_state(tcp_sk, TCP_CLOSE);
2540 }
75e908c3 2541 unlock_sock_fast(tcp_sk, slow);
50c504a2
FW		 2542 }
2543
69800e51
PA		 2544 /* Mirror the tcp_reset() error propagation */
2545 switch (sk->sk_state) {
2546 case TCP_SYN_SENT:
9ae8e5ad 2547 WRITE_ONCE(sk->sk_err, ECONNREFUSED);
69800e51
PA		 2548 break;
2549 case TCP_CLOSE_WAIT:
9ae8e5ad 2550 WRITE_ONCE(sk->sk_err, EPIPE);
69800e51
PA		 2551 break;
2552 case TCP_CLOSE:
2553 return;
2554 default:
9ae8e5ad 2555 WRITE_ONCE(sk->sk_err, ECONNRESET);
69800e51
PA		 2556 }
2557
50c504a2 2558 inet_sk_state_store(sk, TCP_CLOSE);
6b9831bf 2559 WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
50c504a2 2560 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
50c504a2
FW		 2561 set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags);
2562
69800e51
PA		 2563 /* the calling mptcp_worker will properly destroy the socket */
2564 if (sock_flag(sk, SOCK_DEAD))
2565 return;
2566
2567 sk->sk_state_change(sk);
2568 sk_error_report(sk);
50c504a2
FW		 2569}
2570
2948d0a1 2571static void __mptcp_retrans(struct sock *sk)
80992017 2572{
2948d0a1 2573 struct mptcp_sock *msk = mptcp_sk(sk);
ee2708ae 2574 struct mptcp_subflow_context *subflow;
caf971df 2575 struct mptcp_sendmsg_info info = {};
3b1d6210 2576 struct mptcp_data_frag *dfrag;
2948d0a1 2577 struct sock *ssk;
ee2708ae
GT		 2578 int ret, err;
2579 u16 len = 0;
3b1d6210 2580
b5941f06 2581 mptcp_clean_una_wakeup(sk);
3241a9c0
FW		 2582
2583 /* first check ssk: need to kick "stale" logic */
ee2708ae 2584 err = mptcp_sched_get_retrans(msk);
3b1d6210 2585 dfrag = mptcp_rtx_head(sk);
6477dd39
MM		 2586 if (!dfrag) {
2587 if (mptcp_data_fin_enabled(msk)) {
2588 struct inet_connection_sock *icsk = inet_csk(sk);
2589
2590 icsk->icsk_retransmits++;
2591 mptcp_set_datafin_timeout(sk);
2592 mptcp_send_ack(msk);
2593
2594 goto reset_timer;
2595 }
2596
3241a9c0
FW		 2597 if (!mptcp_send_head(sk))
2598 return;
2599
2600 goto reset_timer;
6477dd39 2601 }
3b1d6210 2602
ee2708ae 2603 if (err)
2948d0a1 2604 goto reset_timer;
3b1d6210 2605
ee2708ae
GT		 2606 mptcp_for_each_subflow(msk, subflow) {
2607 if (READ_ONCE(subflow->scheduled)) {
2608 u16 copied = 0;
3b1d6210 2609
ee2708ae 2610 mptcp_subflow_set_scheduled(subflow, false);
3b1d6210 2611
ee2708ae
GT		 2612 ssk = mptcp_subflow_tcp_sock(subflow);
2613
2614 lock_sock(ssk);
2615
2616 /* limit retransmission to the bytes already sent on some subflows */
2617 info.sent = 0;
2618 info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len :
2619 dfrag->already_sent;
2620 while (info.sent < info.limit) {
2621 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
2622 if (ret <= 0)
2623 break;
2624
2625 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RETRANSSEGS);
2626 copied += ret;
2627 info.sent += ret;
2628 }
2629 if (copied) {
2630 len = max(copied, len);
2631 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
2632 info.size_goal);
2633 WRITE_ONCE(msk->allow_infinite_fallback, false);
2634 }
2635
2636 release_sock(ssk);
2637 }
4e14867d 2638 }
3b1d6210 2639
ee2708ae
GT		 2640 msk->bytes_retrans += len;
2641 dfrag->already_sent = max(dfrag->already_sent, len);
3b1d6210 2642
2948d0a1 2643reset_timer:
3241a9c0
FW		 2644 mptcp_check_and_set_pending(sk);
2645
f6909dc1
PA		 2646 if (!mptcp_rtx_timer_pending(sk))
2647 mptcp_reset_rtx_timer(sk);
2948d0a1
PA		 2648}
2649
76a13b31
GT		 2650/* schedule the timeout timer for the relevant event: either close timeout
2651 * or mp_fail timeout. The close timeout takes precedence on the mp_fail one
2652 */
f6909dc1 2653void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout)
76a13b31
GT		 2654{
2655 struct sock *sk = (struct sock *)msk;
2656 unsigned long timeout, close_timeout;
2657
27e5ccc2 2658 if (!fail_tout && !inet_csk(sk)->icsk_mtup.probe_timestamp)
76a13b31
GT		 2659 return;
2660
27e5ccc2
PA		 2661 close_timeout = inet_csk(sk)->icsk_mtup.probe_timestamp - tcp_jiffies32 + jiffies +
2662 TCP_TIMEWAIT_LEN;
76a13b31
GT		 2663
2664 /* the close timeout takes precedence on the fail one, and here at least one of
2665 * them is active
2666 */
27e5ccc2 2667 timeout = inet_csk(sk)->icsk_mtup.probe_timestamp ? close_timeout : fail_tout;
76a13b31
GT		 2668
2669 sk_reset_timer(sk, &sk->sk_timer, timeout);
2670}
2671
49fa1919
GT		 2672static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)
2673{
76a13b31 2674 struct sock *ssk = msk->first;
49fa1919
GT		 2675 bool slow;
2676
76a13b31
GT		 2677 if (!ssk)
2678 return;
49fa1919 2679
76a13b31
GT		 2680 pr_debug("MP_FAIL doesn't respond, reset the subflow");
2681
2682 slow = lock_sock_fast(ssk);
2683 mptcp_subflow_reset(ssk);
2684 WRITE_ONCE(mptcp_subflow_ctx(ssk)->fail_tout, 0);
2685 unlock_sock_fast(ssk, slow);
49fa1919
GT		 2686}
2687
d21f8348
PA		 2688static void mptcp_do_fastclose(struct sock *sk)
2689{
2690 struct mptcp_subflow_context *subflow, *tmp;
2691 struct mptcp_sock *msk = mptcp_sk(sk);
2692
bbd49d11 2693 inet_sk_state_store(sk, TCP_CLOSE);
d21f8348
PA		 2694 mptcp_for_each_subflow_safe(msk, subflow, tmp)
2695 __mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow),
2696 subflow, MPTCP_CF_FASTCLOSE);
2697}
2698
2948d0a1
PA		 2699static void mptcp_worker(struct work_struct *work)
2700{
2701 struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
80638684 2702 struct sock *sk = (struct sock *)msk;
76a13b31 2703 unsigned long fail_tout;
2948d0a1
PA		 2704 int state;
2705
2706 lock_sock(sk);
2707 state = sk->sk_state;
d6a04437 2708 if (unlikely((1 << state) & (TCPF_CLOSE | TCPF_LISTEN)))
2948d0a1
PA		 2709 goto unlock;
2710
2948d0a1
PA		 2711 mptcp_check_fastclose(msk);
2712
86e39e04 2713 mptcp_pm_nl_work(msk);
2948d0a1 2714
81c1d029
PA		 2715 mptcp_check_send_data_fin(sk);
2716 mptcp_check_data_fin_ack(sk);
2948d0a1
PA		 2717 mptcp_check_data_fin(sk);
2718
b6985b9b
PA		 2719 if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags))
2720 __mptcp_close_subflow(sk);
2721
27e5ccc2
PA		 2722 if (mptcp_close_tout_expired(sk)) {
2723 mptcp_do_fastclose(sk);
2724 mptcp_close_wake_up(sk);
2725 }
bbd49d11 2726
27e5ccc2
PA		 2727 if (sock_flag(sk, SOCK_DEAD) && sk->sk_state == TCP_CLOSE) {
2728 __mptcp_destroy_sock(sk);
2729 goto unlock;
2948d0a1
PA		 2730 }
2731
2948d0a1
PA		 2732 if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags))
2733 __mptcp_retrans(sk);
3b1d6210 2734
76a13b31
GT		 2735 fail_tout = msk->first ? READ_ONCE(mptcp_subflow_ctx(msk->first)->fail_tout) : 0;
2736 if (fail_tout && time_after(jiffies, fail_tout))
2737 mptcp_mp_fail_no_response(msk);
49fa1919 2738
3b1d6210 2739unlock:
80992017
PA		 2740 release_sock(sk);
2741 sock_put(sk);
2742}
2743
e2636917 2744static void __mptcp_init_sock(struct sock *sk)
f870fa0b 2745{
cec37a6e
PK		 2746 struct mptcp_sock *msk = mptcp_sk(sk);
2747
2748 INIT_LIST_HEAD(&msk->conn_list);
ec3edaa7 2749 INIT_LIST_HEAD(&msk->join_list);
18b683bf 2750 INIT_LIST_HEAD(&msk->rtx_queue);
80992017 2751 INIT_WORK(&msk->work, mptcp_worker);
87952603 2752 __skb_queue_head_init(&msk->receive_queue);
ab174ad8 2753 msk->out_of_order_queue = RB_ROOT;
f0e6a4cf 2754 msk->first_pending = NULL;
6511882c 2755 msk->rmem_fwd_alloc = 0;
ce599c51 2756 WRITE_ONCE(msk->rmem_released, 0);
33d41c9c 2757 msk->timer_ival = TCP_RTO_MIN;
cec37a6e 2758
1b1b43ee 2759 WRITE_ONCE(msk->first, NULL);
dc24f8b4 2760 inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
752e9067 2761 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
0530020a 2762 WRITE_ONCE(msk->allow_infinite_fallback, true);
1e1d9d6f 2763 msk->recovery = false;
6f06b4d4 2764 msk->subflow_id = 1;
8ab183de 2765
1b1c7a0e
PK		 2766 mptcp_pm_data_init(msk);
2767
b51f9b80
PA		 2768 /* re-use the csk retrans timer for MPTCP-level retrans */
2769 timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0);
f6909dc1 2770 timer_setup(&sk->sk_timer, mptcp_tout_timer, 0);
f870fa0b
MM		 2771}
2772
b29fcfb5 2773static void mptcp_ca_reset(struct sock *sk)
784325e9 2774{
20b5759f 2775 struct inet_connection_sock *icsk = inet_csk(sk);
b29fcfb5
PA		 2776
2777 tcp_assign_congestion_control(sk);
2778 strcpy(mptcp_sk(sk)->ca_name, icsk->icsk_ca_ops->name);
2779
2780 /* no need to keep a reference to the ops, the name will suffice */
2781 tcp_cleanup_congestion_control(sk);
2782 icsk->icsk_ca_ops = NULL;
2783}
2784
2785static int mptcp_init_sock(struct sock *sk)
2786{
fc518953 2787 struct net *net = sock_net(sk);
1730b2b2 2788 int ret;
18b683bf 2789
e2636917 2790 __mptcp_init_sock(sk);
b6c08380 2791
fc518953
FW		 2792 if (!mptcp_is_enabled(net))
2793 return -ENOPROTOOPT;
2794
2795 if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net))
2796 return -ENOMEM;
2797
1730b2b2
GT		 2798 ret = mptcp_init_sched(mptcp_sk(sk),
2799 mptcp_sched_find(mptcp_get_scheduler(net)));
2800 if (ret)
2801 return ret;
2802
a5ef058d
PA		 2803 set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
2804
20b5759f
PA		 2805 /* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will
2806 * propagate the correct value
2807 */
b29fcfb5 2808 mptcp_ca_reset(sk);
20b5759f 2809
d027236c 2810 sk_sockets_allocated_inc(sk);
a963853f
GT		 2811 sk->sk_rcvbuf = READ_ONCE(net->ipv4.sysctl_tcp_rmem[1]);
2812 sk->sk_sndbuf = READ_ONCE(net->ipv4.sysctl_tcp_wmem[1]);
d027236c 2813
18b683bf
PA		 2814 return 0;
2815}
2816
2817static void __mptcp_clear_xmit(struct sock *sk)
2818{
2819 struct mptcp_sock *msk = mptcp_sk(sk);
2820 struct mptcp_data_frag *dtmp, *dfrag;
2821
d9ca1de8 2822 WRITE_ONCE(msk->first_pending, NULL);
18b683bf 2823 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list)
d027236c 2824 dfrag_clear(sk, dfrag);
784325e9
MB		 2825}
2826
30e51b92 2827void mptcp_cancel_work(struct sock *sk)
80992017
PA		 2828{
2829 struct mptcp_sock *msk = mptcp_sk(sk);
2830
b2771d24 2831 if (cancel_work_sync(&msk->work))
e16163b6 2832 __sock_put(sk);
80992017
PA		 2833}
2834
d0876b22 2835void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
21498490
PK		 2836{
2837 lock_sock(ssk);
2838
2839 switch (ssk->sk_state) {
2840 case TCP_LISTEN:
2841 if (!(how & RCV_SHUTDOWN))
2842 break;
df561f66 2843 fallthrough;
21498490 2844 case TCP_SYN_SENT:
c2b2ae39 2845 WARN_ON_ONCE(tcp_disconnect(ssk, O_NONBLOCK));
21498490
PK		 2846 break;
2847 default:
43b54c6e
MM		 2848 if (__mptcp_check_fallback(mptcp_sk(sk))) {
2849 pr_debug("Fallback");
2850 ssk->sk_shutdown |= how;
2851 tcp_shutdown(ssk, how);
81c1d029
PA		 2852
2853 /* simulate the data_fin ack reception to let the state
2854 * machine move forward
2855 */
2856 WRITE_ONCE(mptcp_sk(sk)->snd_una, mptcp_sk(sk)->snd_nxt);
2857 mptcp_schedule_work(sk);
43b54c6e
MM		 2858 } else {
2859 pr_debug("Sending DATA_FIN on subflow %p", ssk);
43b54c6e 2860 tcp_send_ack(ssk);
f6909dc1
PA		 2861 if (!mptcp_rtx_timer_pending(sk))
2862 mptcp_reset_rtx_timer(sk);
43b54c6e 2863 }
21498490
PK		 2864 break;
2865 }
2866
21498490
PK		 2867 release_sock(ssk);
2868}
2869
6920b851
MM		 2870static const unsigned char new_state[16] = {
2871 /* current state: new state: action: */
2872 [0 /* (Invalid) */] = TCP_CLOSE,
2873 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2874 [TCP_SYN_SENT] = TCP_CLOSE,
2875 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2876 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
2877 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
2878 [TCP_TIME_WAIT] = TCP_CLOSE, /* should not happen ! */
2879 [TCP_CLOSE] = TCP_CLOSE,
2880 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
2881 [TCP_LAST_ACK] = TCP_LAST_ACK,
2882 [TCP_LISTEN] = TCP_CLOSE,
2883 [TCP_CLOSING] = TCP_CLOSING,
2884 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
2885};
2886
2887static int mptcp_close_state(struct sock *sk)
2888{
2889 int next = (int)new_state[sk->sk_state];
2890 int ns = next & TCP_STATE_MASK;
2891
2892 inet_sk_state_store(sk, ns);
2893
2894 return next & TCP_ACTION_FIN;
2895}
2896
81c1d029 2897static void mptcp_check_send_data_fin(struct sock *sk)
f870fa0b 2898{
e16163b6 2899 struct mptcp_subflow_context *subflow;
f870fa0b
MM		 2900 struct mptcp_sock *msk = mptcp_sk(sk);
2901
e16163b6
PA		 2902 pr_debug("msk=%p snd_data_fin_enable=%d pending=%d snd_nxt=%llu write_seq=%llu",
2903 msk, msk->snd_data_fin_enable, !!mptcp_send_head(sk),
2904 msk->snd_nxt, msk->write_seq);
43b54c6e 2905
e16163b6
PA		 2906 /* we still need to enqueue subflows or not really shutting down,
2907 * skip this
2908 */
2909 if (!msk->snd_data_fin_enable || msk->snd_nxt + 1 != msk->write_seq ||
2910 mptcp_send_head(sk))
2911 return;
2912
2913 WRITE_ONCE(msk->snd_nxt, msk->write_seq);
2914
e16163b6
PA		 2915 mptcp_for_each_subflow(msk, subflow) {
2916 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
43b54c6e 2917
e16163b6 2918 mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN);
43b54c6e 2919 }
e16163b6 2920}
2c22c06c 2921
e16163b6
PA		 2922static void __mptcp_wr_shutdown(struct sock *sk)
2923{
2924 struct mptcp_sock *msk = mptcp_sk(sk);
43b54c6e 2925
e16163b6
PA		 2926 pr_debug("msk=%p snd_data_fin_enable=%d shutdown=%x state=%d pending=%d",
2927 msk, msk->snd_data_fin_enable, sk->sk_shutdown, sk->sk_state,
2928 !!mptcp_send_head(sk));
2929
2930 /* will be ignored by fallback sockets */
2931 WRITE_ONCE(msk->write_seq, msk->write_seq + 1);
2932 WRITE_ONCE(msk->snd_data_fin_enable, 1);
2933
81c1d029 2934 mptcp_check_send_data_fin(sk);
e16163b6
PA		 2935}
2936
2937static void __mptcp_destroy_sock(struct sock *sk)
2938{
e16163b6 2939 struct mptcp_sock *msk = mptcp_sk(sk);
e16163b6
PA		 2940
2941 pr_debug("msk=%p", msk);
f870fa0b 2942
3abc05d9
FW		 2943 might_sleep();
2944
f6909dc1 2945 mptcp_stop_rtx_timer(sk);
e16163b6
PA		 2946 sk_stop_timer(sk, &sk->sk_timer);
2947 msk->pm.status = 0;
1730b2b2 2948 mptcp_release_sched(msk);
b2c5b614 2949
e16163b6 2950 sk->sk_prot->destroy(sk);
80992017 2951
6511882c 2952 WARN_ON_ONCE(msk->rmem_fwd_alloc);
87952603 2953 WARN_ON_ONCE(msk->rmem_released);
e16163b6
PA		 2954 sk_stream_kill_queues(sk);
2955 xfrm_sk_free_policy(sk);
aa1fbd94 2956
e16163b6
PA		 2957 sock_put(sk);
2958}
2959
63740448
PA		 2960void __mptcp_unaccepted_force_close(struct sock *sk)
2961{
2962 sock_set_flag(sk, SOCK_DEAD);
63740448
PA		 2963 mptcp_do_fastclose(sk);
2964 __mptcp_destroy_sock(sk);
2965}
2966
d21f8348
PA		 2967static __poll_t mptcp_check_readable(struct mptcp_sock *msk)
2968{
2969 /* Concurrent splices from sk_receive_queue into receive_queue will
2970 * always show at least one non-empty queue when checked in this order.
2971 */
2972 if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) &&
2973 skb_queue_empty_lockless(&msk->receive_queue))
2974 return 0;
2975
2976 return EPOLLIN | EPOLLRDNORM;
2977}
2978
57fc0f1c 2979static void mptcp_check_listen_stop(struct sock *sk)
c558246e 2980{
57fc0f1c
PA		 2981 struct sock *ssk;
2982
2983 if (inet_sk_state_load(sk) != TCP_LISTEN)
2984 return;
2985
2986 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
2987 ssk = mptcp_sk(sk)->first;
2988 if (WARN_ON_ONCE(!ssk || inet_sk_state_load(ssk) != TCP_LISTEN))
2989 return;
2990
2991 lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
3fffa15b 2992 tcp_set_state(ssk, TCP_CLOSE);
57fc0f1c
PA		 2993 mptcp_subflow_queue_clean(sk, ssk);
2994 inet_csk_listen_stop(ssk);
2995 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CLOSED);
57fc0f1c 2996 release_sock(ssk);
c558246e
MD		 2997}
2998
26d3e21c 2999bool __mptcp_close(struct sock *sk, long timeout)
e16163b6
PA		 3000{
3001 struct mptcp_subflow_context *subflow;
76a13b31 3002 struct mptcp_sock *msk = mptcp_sk(sk);
e16163b6 3003 bool do_cancel_work = false;
d4e85922 3004 int subflows_alive = 0;
e16163b6 3005
6b9831bf 3006 WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
e16163b6
PA		 3007
3008 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) {
57fc0f1c 3009 mptcp_check_listen_stop(sk);
e16163b6
PA		 3010 inet_sk_state_store(sk, TCP_CLOSE);
3011 goto cleanup;
3012 }
6771bfd9 3013
8d547809
PA		 3014 if (mptcp_check_readable(msk) || timeout < 0) {
3015 /* If the msk has read data, or the caller explicitly ask it,
3016 * do the MPTCP equivalent of TCP reset, aka MPTCP fastclose
3017 */
d21f8348 3018 mptcp_do_fastclose(sk);
8d547809 3019 timeout = 0;
d21f8348 3020 } else if (mptcp_close_state(sk)) {
e16163b6 3021 __mptcp_wr_shutdown(sk);
d21f8348 3022 }
e16163b6
PA		 3023
3024 sk_stream_wait_close(sk, timeout);
3025
3026cleanup:
3027 /* orphan all the subflows */
76a13b31 3028 mptcp_for_each_subflow(msk, subflow) {
e16163b6 3029 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
49054556 3030 bool slow = lock_sock_fast_nested(ssk);
e16163b6 3031
d4e85922
PA		 3032 subflows_alive += ssk->sk_state != TCP_CLOSE;
3033
76a13b31
GT		 3034 /* since the close timeout takes precedence on the fail one,
3035 * cancel the latter
3036 */
3037 if (ssk == msk->first)
3038 subflow->fail_tout = 0;
3039
fe948001
MD		 3040 /* detach from the parent socket, but allow data_ready to
3041 * push incoming data into the mptcp stack, to properly ack it
3042 */
3043 ssk->sk_socket = NULL;
3044 ssk->sk_wq = NULL;
e16163b6 3045 unlock_sock_fast(ssk, slow);
e16163b6
PA		 3046 }
3047 sock_orphan(sk);
3048
d4e85922
PA		 3049 /* all the subflows are closed, only timeout can change the msk
3050 * state, let's not keep resources busy for no reasons
3051 */
3052 if (subflows_alive == 0)
3053 inet_sk_state_store(sk, TCP_CLOSE);
3054
e16163b6
PA		 3055 sock_hold(sk);
3056 pr_debug("msk=%p state=%d", sk, sk->sk_state);
00df24f1 3057 if (msk->token)
76a13b31 3058 mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);
b29fcfb5 3059
e16163b6
PA		 3060 if (sk->sk_state == TCP_CLOSE) {
3061 __mptcp_destroy_sock(sk);
3062 do_cancel_work = true;
3063 } else {
27e5ccc2 3064 mptcp_start_tout_timer(sk);
e16163b6 3065 }
26d3e21c
MD		 3066
3067 return do_cancel_work;
3068}
3069
3070static void mptcp_close(struct sock *sk, long timeout)
3071{
3072 bool do_cancel_work;
3073
3074 lock_sock(sk);
3075
3076 do_cancel_work = __mptcp_close(sk, timeout);
e16163b6
PA		 3077 release_sock(sk);
3078 if (do_cancel_work)
3079 mptcp_cancel_work(sk);
b911c97c 3080
e16163b6 3081 sock_put(sk);
f870fa0b
MM		 3082}
3083
7e8b88ec 3084static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
cf7da0d6
PK		 3085{
3086#if IS_ENABLED(CONFIG_MPTCP_IPV6)
3087 const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
3088 struct ipv6_pinfo *msk6 = inet6_sk(msk);
3089
3090 msk->sk_v6_daddr = ssk->sk_v6_daddr;
3091 msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;
3092
3093 if (msk6 && ssk6) {
3094 msk6->saddr = ssk6->saddr;
3095 msk6->flow_label = ssk6->flow_label;
3096 }
3097#endif
3098
3099 inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num;
3100 inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport;
3101 inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport;
3102 inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr;
3103 inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr;
3104 inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr;
3105}
3106
18b683bf
PA		 3107static int mptcp_disconnect(struct sock *sk, int flags)
3108{
76e2a55d
PA		 3109 struct mptcp_sock *msk = mptcp_sk(sk);
3110
7d803344
PA		 3111 /* We are on the fastopen error path. We can't call straight into the
3112 * subflows cleanup code due to lock nesting (we are already under
c2b2ae39 3113 * msk->firstsocket lock).
7d803344
PA		 3114 */
3115 if (msk->fastopening)
c2b2ae39 3116 return -EBUSY;
7d803344 3117
57fc0f1c 3118 mptcp_check_listen_stop(sk);
b29fcfb5
PA		 3119 inet_sk_state_store(sk, TCP_CLOSE);
3120
f6909dc1 3121 mptcp_stop_rtx_timer(sk);
27e5ccc2 3122 mptcp_stop_tout_timer(sk);
b29fcfb5 3123
00df24f1
GT		 3124 if (msk->token)
3125 mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);
b29fcfb5 3126
c0bf3c6a
PA		 3127 /* msk->subflow is still intact, the following will not free the first
3128 * subflow
3129 */
3130 mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE);
e9d09bac
PA		 3131 WRITE_ONCE(msk->flags, 0);
3132 msk->cb_flags = 0;
3133 msk->push_pending = 0;
b29fcfb5
PA		 3134 msk->recovery = false;
3135 msk->can_ack = false;
3136 msk->fully_established = false;
3137 msk->rcv_data_fin = false;
3138 msk->snd_data_fin_enable = false;
3139 msk->rcv_fastclose = false;
3140 msk->use_64bit_ack = false;
3141 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
3142 mptcp_pm_data_reset(msk);
3143 mptcp_ca_reset(sk);
38967f42
PA		 3144 msk->bytes_acked = 0;
3145 msk->bytes_received = 0;
3146 msk->bytes_sent = 0;
3147 msk->bytes_retrans = 0;
b29fcfb5 3148
6b9831bf 3149 WRITE_ONCE(sk->sk_shutdown, 0);
b29fcfb5 3150 sk_error_report(sk);
42c556fe 3151 return 0;
18b683bf
PA		 3152}
3153
b0519de8
FW		 3154#if IS_ENABLED(CONFIG_MPTCP_IPV6)
3155static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
3156{
3157 unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);
3158
3159 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
3160}
3161#endif
3162
7e8b88ec
PA		 3163struct sock *mptcp_sk_clone_init(const struct sock *sk,
3164 const struct mptcp_options_received *mp_opt,
3165 struct sock *ssk,
3166 struct request_sock *req)
b0519de8 3167{
58b09919 3168 struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
b0519de8 3169 struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC);
58b09919 3170 struct mptcp_sock *msk;
b0519de8
FW		 3171
3172 if (!nsk)
3173 return NULL;
3174
3175#if IS_ENABLED(CONFIG_MPTCP_IPV6)
3176 if (nsk->sk_family == AF_INET6)
3177 inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk);
3178#endif
3179
58b09919
PA		 3180 __mptcp_init_sock(nsk);
3181
3182 msk = mptcp_sk(nsk);
3183 msk->local_key = subflow_req->local_key;
3184 msk->token = subflow_req->token;
b6985b9b 3185 msk->in_accept_queue = 1;
b93df08c 3186 WRITE_ONCE(msk->fully_established, false);
74c7dfbe 3187 if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD)
06251181 3188 WRITE_ONCE(msk->csum_enabled, true);
58b09919 3189
58b09919 3190 msk->write_seq = subflow_req->idsn + 1;
eaa2ffab 3191 msk->snd_nxt = msk->write_seq;
7439d687
PA		 3192 msk->snd_una = msk->write_seq;
3193 msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
df00b087 3194 msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
1730b2b2 3195 mptcp_init_sched(msk, mptcp_sk(sk)->sched);
6f8a612a 3196
6f06b4d4
PA		 3197 /* passive msk is created after the first/MPC subflow */
3198 msk->subflow_id = 2;
3199
5e20087d 3200 sock_reset_flag(nsk, SOCK_RCU_FREE);
0c148460 3201 security_inet_csk_clone(nsk, req);
7e8b88ec
PA		 3202
3203 /* this can't race with mptcp_close(), as the msk is
3204 * not yet exposted to user-space
3205 */
3206 inet_sk_state_store(nsk, TCP_ESTABLISHED);
3207
3208 /* The msk maintain a ref to each subflow in the connections list */
3209 WRITE_ONCE(msk->first, ssk);
3210 list_add(&mptcp_subflow_ctx(ssk)->node, &msk->conn_list);
3211 sock_hold(ssk);
3212
3213 /* new mpc subflow takes ownership of the newly
3214 * created mptcp socket
3215 */
3216 mptcp_token_accept(subflow_req, msk);
3217
3218 /* set msk addresses early to ensure mptcp_pm_get_local_id()
3219 * uses the correct data
3220 */
3221 mptcp_copy_inaddrs(nsk, ssk);
3222 mptcp_propagate_sndbuf(nsk, ssk);
3223
3224 mptcp_rcv_space_init(msk, ssk);
58b09919
PA		 3225 bh_unlock_sock(nsk);
3226
b6985b9b 3227 /* note: the newly allocated socket refcount is 2 now */
b0519de8
FW		 3228 return nsk;
3229}
3230
a6b118fe
FW		 3231void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk)
3232{
3233 const struct tcp_sock *tp = tcp_sk(ssk);
3234
3235 msk->rcvq_space.copied = 0;
3236 msk->rcvq_space.rtt_us = 0;
3237
3238 msk->rcvq_space.time = tp->tcp_mstamp;
3239
3240 /* initial rcv_space offering made to peer */
3241 msk->rcvq_space.space = min_t(u32, tp->rcv_wnd,
3242 TCP_INIT_CWND * tp->advmss);
3243 if (msk->rcvq_space.space == 0)
3244 msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT;
6f8a612a 3245
7439d687 3246 WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);
a6b118fe
FW		 3247}
3248
1f6610b9 3249static struct sock *mptcp_accept(struct sock *ssk, int flags, int *err,
cf7da0d6
PK		 3250 bool kern)
3251{
cf7da0d6
PK		 3252 struct sock *newsk;
3253
1f6610b9
PA		 3254 pr_debug("ssk=%p, listener=%p", ssk, mptcp_subflow_ctx(ssk));
3255 newsk = inet_csk_accept(ssk, flags, err, kern);
cf7da0d6
PK		 3256 if (!newsk)
3257 return NULL;
3258
1f6610b9 3259 pr_debug("newsk=%p, subflow is mptcp=%d", newsk, sk_is_mptcp(newsk));
cf7da0d6
PK		 3260 if (sk_is_mptcp(newsk)) {
3261 struct mptcp_subflow_context *subflow;
3262 struct sock *new_mptcp_sock;
cf7da0d6
PK		 3263
3264 subflow = mptcp_subflow_ctx(newsk);
58b09919 3265 new_mptcp_sock = subflow->conn;
cf7da0d6 3266
58b09919
PA		 3267 /* is_mptcp should be false if subflow->conn is missing, see
3268 * subflow_syn_recv_sock()
3269 */
3270 if (WARN_ON_ONCE(!new_mptcp_sock)) {
3271 tcp_sk(newsk)->is_mptcp = 0;
d6692b3b 3272 goto out;
cf7da0d6
PK		 3273 }
3274
cf7da0d6 3275 newsk = new_mptcp_sock;
1f6610b9 3276 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
fc518953 3277 } else {
1f6610b9 3278 MPTCP_INC_STATS(sock_net(ssk),
fc518953 3279 MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
cf7da0d6
PK		 3280 }
3281
d6692b3b
FW		 3282out:
3283 newsk->sk_kern_sock = kern;
cf7da0d6
PK		 3284 return newsk;
3285}
3286
c0bf3c6a 3287void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags)
5c8c1640 3288{
c0bf3c6a 3289 struct mptcp_subflow_context *subflow, *tmp;
87952603
PA		 3290 struct sock *sk = (struct sock *)msk;
3291
6e628cd3
PA		 3292 __mptcp_clear_xmit(sk);
3293
c0bf3c6a 3294 /* join list will be eventually flushed (with rst) at sock lock release time */
5efbf6f7 3295 mptcp_for_each_subflow_safe(msk, subflow, tmp)
c0bf3c6a
PA		 3296 __mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow), subflow, flags);
3297
87952603 3298 /* move to sk_receive_queue, sk_stream_kill_queues will purge it */
b29fcfb5 3299 mptcp_data_lock(sk);
87952603 3300 skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue);
6511882c 3301 __skb_queue_purge(&sk->sk_receive_queue);
5c8c1640 3302 skb_rbtree_purge(&msk->out_of_order_queue);
b29fcfb5 3303 mptcp_data_unlock(sk);
6511882c
PA		 3304
3305 /* move all the rx fwd alloc into the sk_mem_reclaim_final in
3306 * inet_sock_destruct() will dispose it
3307 */
5e6300e7 3308 sk_forward_alloc_add(sk, msk->rmem_fwd_alloc);
9531e4a8 3309 WRITE_ONCE(msk->rmem_fwd_alloc, 0);
5c8c1640
GT		 3310 mptcp_token_destroy(msk);
3311 mptcp_pm_free_anno_list(msk);
4638de5a 3312 mptcp_free_local_addr_list(msk);
5c8c1640
GT		 3313}
3314
79c0949e
PK		 3315static void mptcp_destroy(struct sock *sk)
3316{
c9fd9c5f
FW		 3317 struct mptcp_sock *msk = mptcp_sk(sk);
3318
39880bd8
PA		 3319 /* allow the following to close even the initial subflow */
3320 msk->free_first = 1;
c0bf3c6a 3321 mptcp_destroy_common(msk, 0);
d027236c 3322 sk_sockets_allocated_dec(sk);
79c0949e
PK		 3323}
3324
6e628cd3
PA		 3325void __mptcp_data_acked(struct sock *sk)
3326{
3327 if (!sock_owned_by_user(sk))
3328 __mptcp_clean_una(sk);
3329 else
e9d09bac 3330 __set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags);
6e628cd3
PA		 3331
3332 if (mptcp_pending_data_fin_ack(sk))
3333 mptcp_schedule_work(sk);
3334}
3335
219d0499 3336void __mptcp_check_push(struct sock *sk, struct sock *ssk)
6e628cd3
PA		 3337{
3338 if (!mptcp_send_head(sk))
3339 return;
3340
73a0052a
GT		 3341 if (!sock_owned_by_user(sk))
3342 __mptcp_subflow_push_pending(sk, ssk, false);
3343 else
e9d09bac 3344 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags);
6e628cd3
PA		 3345}
3346
e9d09bac
PA		 3347#define MPTCP_FLAGS_PROCESS_CTX_NEED (BIT(MPTCP_PUSH_PENDING) | \
3348 BIT(MPTCP_RETRANSMIT) | \
3349 BIT(MPTCP_FLUSH_JOIN_LIST))
3350
e93da928 3351/* processes deferred events and flush wmem */
14c441b5 3352static void mptcp_release_cb(struct sock *sk)
e9d09bac 3353 __must_hold(&sk->sk_lock.slock)
14c441b5 3354{
e9d09bac
PA		 3355 struct mptcp_sock *msk = mptcp_sk(sk);
3356
c2e6048f 3357 for (;;) {
e9d09bac
PA		 3358 unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) |
3359 msk->push_pending;
56a666c4
PA		 3360 struct list_head join_list;
3361
c2e6048f
PA		 3362 if (!flags)
3363 break;
3364
56a666c4
PA		 3365 INIT_LIST_HEAD(&join_list);
3366 list_splice_init(&msk->join_list, &join_list);
3367
c2e6048f 3368 /* the following actions acquire the subflow socket lock
6e628cd3
PA		 3369 *
3370 * 1) can't be invoked in atomic scope
3371 * 2) must avoid ABBA deadlock with msk socket spinlock: the RX
3372 * datapath acquires the msk socket spinlock while helding
3373 * the subflow socket lock
3374 */
e9d09bac
PA		 3375 msk->push_pending = 0;
3376 msk->cb_flags &= ~flags;
6e628cd3 3377 spin_unlock_bh(&sk->sk_lock.slock);
56a666c4 3378
3e501490 3379 if (flags & BIT(MPTCP_FLUSH_JOIN_LIST))
56a666c4 3380 __mptcp_flush_join_list(sk, &join_list);
2e5de7e0 3381 if (flags & BIT(MPTCP_PUSH_PENDING))
c2e6048f 3382 __mptcp_push_pending(sk, 0);
2d6f5a2b
PA		 3383 if (flags & BIT(MPTCP_RETRANSMIT))
3384 __mptcp_retrans(sk);
c2e6048f
PA		 3385
3386 cond_resched();
6e628cd3
PA		 3387 spin_lock_bh(&sk->sk_lock.slock);
3388 }
c2e6048f 3389
e9d09bac 3390 if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags))
417789df 3391 __mptcp_clean_una_wakeup(sk);
17ebf8a4 3392 if (unlikely(msk->cb_flags)) {
65a569b0
PA		 3393 /* be sure to set the current sk state before tacking actions
3394 * depending on sk_state, that is processing MPTCP_ERROR_REPORT
3395 */
3396 if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags))
3397 __mptcp_set_connected(sk);
3398 if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags))
3399 __mptcp_error_report(sk);
3400 }
6e628cd3 3401
87952603 3402 __mptcp_update_rmem(sk);
14c441b5
PA		 3403}
3404
bcd97734
PA		 3405/* MP_JOIN client subflow must wait for 4th ack before sending any data:
3406 * TCP can't schedule delack timer before the subflow is fully established.
3407 * MPTCP uses the delack timer to do 3rd ack retransmissions
3408 */
3409static void schedule_3rdack_retransmission(struct sock *ssk)
3410{
3411 struct inet_connection_sock *icsk = inet_csk(ssk);
3412 struct tcp_sock *tp = tcp_sk(ssk);
3413 unsigned long timeout;
3414
3415 if (mptcp_subflow_ctx(ssk)->fully_established)
3416 return;
3417
3418 /* reschedule with a timeout above RTT, as we must look only for drop */
3419 if (tp->srtt_us)
3420 timeout = usecs_to_jiffies(tp->srtt_us >> (3 - 1));
3421 else
3422 timeout = TCP_TIMEOUT_INIT;
3423 timeout += jiffies;
3424
3425 WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER);
3426 icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
3427 icsk->icsk_ack.timeout = timeout;
3428 sk_reset_timer(ssk, &icsk->icsk_delack_timer, timeout);
3429}
3430
a5efdbce 3431void mptcp_subflow_process_delegated(struct sock *ssk, long status)
b19bc294
PA		 3432{
3433 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
3434 struct sock *sk = subflow->conn;
3435
a5efdbce 3436 if (status & BIT(MPTCP_DELEGATE_SEND)) {
bcd97734
PA		 3437 mptcp_data_lock(sk);
3438 if (!sock_owned_by_user(sk))
73a0052a 3439 __mptcp_subflow_push_pending(sk, ssk, true);
bcd97734 3440 else
e9d09bac 3441 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags);
bcd97734 3442 mptcp_data_unlock(sk);
bcd97734 3443 }
a5efdbce 3444 if (status & BIT(MPTCP_DELEGATE_ACK))
bcd97734 3445 schedule_3rdack_retransmission(ssk);
b19bc294
PA		 3446}
3447
2c5ebd00
PA		 3448static int mptcp_hash(struct sock *sk)
3449{
3450 /* should never be called,
3451 * we hash the TCP subflows not the master socket
3452 */
3453 WARN_ON_ONCE(1);
3454 return 0;
3455}
3456
3457static void mptcp_unhash(struct sock *sk)
3458{
3459 /* called from sk_common_release(), but nothing to do here */
3460}
3461
cec37a6e 3462static int mptcp_get_port(struct sock *sk, unsigned short snum)
f870fa0b
MM		 3463{
3464 struct mptcp_sock *msk = mptcp_sk(sk);
f870fa0b 3465
cfb63e50
PA		 3466 pr_debug("msk=%p, ssk=%p", msk, msk->first);
3467 if (WARN_ON_ONCE(!msk->first))
cec37a6e 3468 return -EINVAL;
f870fa0b 3469
cfb63e50 3470 return inet_csk_get_port(msk->first, snum);
cec37a6e 3471}
f870fa0b 3472
cec37a6e
PK		 3473void mptcp_finish_connect(struct sock *ssk)
3474{
3475 struct mptcp_subflow_context *subflow;
3476 struct mptcp_sock *msk;
3477 struct sock *sk;
f870fa0b 3478
cec37a6e 3479 subflow = mptcp_subflow_ctx(ssk);
cec37a6e
PK		 3480 sk = subflow->conn;
3481 msk = mptcp_sk(sk);
3482
648ef4b8
MM		 3483 pr_debug("msk=%p, token=%u", sk, subflow->token);
3484
b3ea6b27 3485 subflow->map_seq = subflow->iasn;
648ef4b8 3486 subflow->map_subflow_seq = 1;
6d0060f6 3487
cec37a6e
PK		 3488 /* the socket is not connected yet, no msk/subflow ops can access/race
3489 * accessing the field below
3490 */
cec37a6e 3491 WRITE_ONCE(msk->local_key, subflow->local_key);
6d0060f6 3492 WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
eaa2ffab 3493 WRITE_ONCE(msk->snd_nxt, msk->write_seq);
7439d687 3494 WRITE_ONCE(msk->snd_una, msk->write_seq);
1b1c7a0e 3495
6c714f1b 3496 mptcp_pm_new_connection(msk, ssk, 0);
a6b118fe
FW		 3497
3498 mptcp_rcv_space_init(msk, ssk);
f870fa0b
MM		 3499}
3500
866f26f2 3501void mptcp_sock_graft(struct sock *sk, struct socket *parent)
cf7da0d6
PK		 3502{
3503 write_lock_bh(&sk->sk_callback_lock);
3504 rcu_assign_pointer(sk->sk_wq, &parent->wq);
3505 sk_set_socket(sk, parent);
3506 sk->sk_uid = SOCK_INODE(parent)->i_uid;
3507 write_unlock_bh(&sk->sk_callback_lock);
3508}
3509
e16163b6 3510bool mptcp_finish_join(struct sock *ssk)
f296234c 3511{
e16163b6 3512 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
f296234c
PK		 3513 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
3514 struct sock *parent = (void *)msk;
3e501490 3515 bool ret = true;
f296234c
PK		 3516
3517 pr_debug("msk=%p, subflow=%p", msk, subflow);
3518
3519 /* mptcp socket already closing? */
dc87efdb
FW		 3520 if (!mptcp_is_fully_established(parent)) {
3521 subflow->reset_reason = MPTCP_RST_EMPTCP;
f296234c 3522 return false;
dc87efdb 3523 }
f296234c 3524
55b47ca7
PA		 3525 /* active subflow, already present inside the conn_list */
3526 if (!list_empty(&subflow->node)) {
3527 mptcp_subflow_joined(msk, ssk);
3528 return true;
3529 }
f296234c 3530
3e501490
PA		 3531 if (!mptcp_pm_allow_new_subflow(msk))
3532 goto err_prohibited;
10f6d46c 3533
55b47ca7 3534 /* If we can't acquire msk socket lock here, let the release callback
3e501490 3535 * handle it
10f6d46c 3536 */
3e501490
PA		 3537 mptcp_data_lock(parent);
3538 if (!sock_owned_by_user(parent)) {
3539 ret = __mptcp_finish_join(msk, ssk);
3540 if (ret) {
3541 sock_hold(ssk);
3542 list_add_tail(&subflow->node, &msk->conn_list);
3543 }
3544 } else {
e16163b6 3545 sock_hold(ssk);
3e501490 3546 list_add_tail(&subflow->node, &msk->join_list);
e9d09bac 3547 __set_bit(MPTCP_FLUSH_JOIN_LIST, &msk->cb_flags);
e16163b6 3548 }
3e501490
PA		 3549 mptcp_data_unlock(parent);
3550
dc87efdb 3551 if (!ret) {
3e501490 3552err_prohibited:
dc87efdb 3553 subflow->reset_reason = MPTCP_RST_EPROHIBIT;
10f6d46c 3554 return false;
dc87efdb 3555 }
10f6d46c 3556
10f6d46c 3557 return true;
f296234c
PK		 3558}
3559
76e2a55d
PA		 3560static void mptcp_shutdown(struct sock *sk, int how)
3561{
3562 pr_debug("sk=%p, how=%d", sk, how);
3563
3564 if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk))
3565 __mptcp_wr_shutdown(sk);
3566}
3567
6511882c
PA		 3568static int mptcp_forward_alloc_get(const struct sock *sk)
3569{
9531e4a8
ED		 3570 return READ_ONCE(sk->sk_forward_alloc) +
3571 READ_ONCE(mptcp_sk(sk)->rmem_fwd_alloc);
6511882c
PA		 3572}
3573
644807e3
FW		 3574static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v)
3575{
3576 const struct sock *sk = (void *)msk;
3577 u64 delta;
3578
3579 if (sk->sk_state == TCP_LISTEN)
3580 return -EINVAL;
3581
3582 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
3583 return 0;
3584
3585 delta = msk->write_seq - v;
07c2c7a3
PA		 3586 if (__mptcp_check_fallback(msk) && msk->first) {
3587 struct tcp_sock *tp = tcp_sk(msk->first);
3588
3589 /* the first subflow is disconnected after close - see
3590 * __mptcp_close_ssk(). tcp_disconnect() moves the write_seq
3591 * so ignore that status, too.
3592 */
3593 if (!((1 << msk->first->sk_state) &
3594 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)))
3595 delta += READ_ONCE(tp->write_seq) - tp->snd_una;
3596 }
644807e3
FW		 3597 if (delta > INT_MAX)
3598 delta = INT_MAX;
3599
3600 return (int)delta;
3601}
3602
e1d001fa 3603static int mptcp_ioctl(struct sock *sk, int cmd, int *karg)
644807e3
FW		 3604{
3605 struct mptcp_sock *msk = mptcp_sk(sk);
3606 bool slow;
644807e3
FW		 3607
3608 switch (cmd) {
3609 case SIOCINQ:
3610 if (sk->sk_state == TCP_LISTEN)
3611 return -EINVAL;
3612
3613 lock_sock(sk);
3614 __mptcp_move_skbs(msk);
e1d001fa 3615 *karg = mptcp_inq_hint(sk);
644807e3
FW		 3616 release_sock(sk);
3617 break;
3618 case SIOCOUTQ:
3619 slow = lock_sock_fast(sk);
e1d001fa 3620 *karg = mptcp_ioctl_outq(msk, READ_ONCE(msk->snd_una));
644807e3
FW		 3621 unlock_sock_fast(sk, slow);
3622 break;
3623 case SIOCOUTQNSD:
3624 slow = lock_sock_fast(sk);
e1d001fa 3625 *karg = mptcp_ioctl_outq(msk, msk->snd_nxt);
644807e3
FW		 3626 unlock_sock_fast(sk, slow);
3627 break;
3628 default:
3629 return -ENOIOCTLCMD;
3630 }
3631
e1d001fa 3632 return 0;
644807e3
FW		 3633}
3634
54f1944e
PA		 3635static void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
3636 struct mptcp_subflow_context *subflow)
3637{
3638 subflow->request_mptcp = 0;
3639 __mptcp_do_fallback(msk);
3640}
3641
3642static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
3643{
3644 struct mptcp_subflow_context *subflow;
3645 struct mptcp_sock *msk = mptcp_sk(sk);
54f1944e 3646 int err = -EINVAL;
ccae357c 3647 struct sock *ssk;
54f1944e 3648
3f326a82
PA		 3649 ssk = __mptcp_nmpc_sk(msk);
3650 if (IS_ERR(ssk))
3651 return PTR_ERR(ssk);
54f1944e 3652
54f1944e 3653 inet_sk_state_store(sk, TCP_SYN_SENT);
ccae357c 3654 subflow = mptcp_subflow_ctx(ssk);
54f1944e
PA		 3655#ifdef CONFIG_TCP_MD5SIG
3656 /* no MPTCP if MD5SIG is enabled on this socket or we may run out of
3657 * TCP option space.
3658 */
ccae357c 3659 if (rcu_access_pointer(tcp_sk(ssk)->md5sig_info))
54f1944e
PA		 3660 mptcp_subflow_early_fallback(msk, subflow);
3661#endif
ccae357c
PA		 3662 if (subflow->request_mptcp && mptcp_token_new_connect(ssk)) {
3663 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_TOKENFALLBACKINIT);
54f1944e
PA		 3664 mptcp_subflow_early_fallback(msk, subflow);
3665 }
3666 if (likely(!__mptcp_check_fallback(msk)))
3667 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVE);
3668
3669 /* if reaching here via the fastopen/sendmsg path, the caller already
3670 * acquired the subflow socket lock, too.
3671 */
ccae357c
PA		 3672 if (!msk->fastopening)
3673 lock_sock(ssk);
3674
3675 /* the following mirrors closely a very small chunk of code from
3676 * __inet_stream_connect()
3677 */
3678 if (ssk->sk_state != TCP_CLOSE)
3679 goto out;
3680
3681 if (BPF_CGROUP_PRE_CONNECT_ENABLED(ssk)) {
3682 err = ssk->sk_prot->pre_connect(ssk, uaddr, addr_len);
3683 if (err)
3684 goto out;
3685 }
3686
3687 err = ssk->sk_prot->connect(ssk, uaddr, addr_len);
3688 if (err < 0)
3689 goto out;
3690
08e39c0d 3691 inet_assign_bit(DEFER_CONNECT, sk, inet_test_bit(DEFER_CONNECT, ssk));
ccae357c
PA		 3692
3693out:
3694 if (!msk->fastopening)
3695 release_sock(ssk);
54f1944e
PA		 3696
3697 /* on successful connect, the msk state will be moved to established by
3698 * subflow_finish_connect()
3699 */
ccae357c 3700 if (unlikely(err)) {
131a6277
PA		 3701 /* avoid leaving a dangling token in an unconnected socket */
3702 mptcp_token_destroy(msk);
ccae357c 3703 inet_sk_state_store(sk, TCP_CLOSE);
54f1944e
PA		 3704 return err;
3705 }
3706
ccae357c 3707 mptcp_copy_inaddrs(sk, ssk);
786fc124 3708 return 0;
54f1944e
PA		 3709}
3710
f870fa0b
MM		 3711static struct proto mptcp_prot = {
3712 .name = "MPTCP",
3713 .owner = THIS_MODULE,
3714 .init = mptcp_init_sock,
54f1944e 3715 .connect = mptcp_connect,
18b683bf 3716 .disconnect = mptcp_disconnect,
f870fa0b 3717 .close = mptcp_close,
cf7da0d6 3718 .accept = mptcp_accept,
717e79c8
PK		 3719 .setsockopt = mptcp_setsockopt,
3720 .getsockopt = mptcp_getsockopt,
76e2a55d 3721 .shutdown = mptcp_shutdown,
79c0949e 3722 .destroy = mptcp_destroy,
f870fa0b 3723 .sendmsg = mptcp_sendmsg,
644807e3 3724 .ioctl = mptcp_ioctl,
f870fa0b 3725 .recvmsg = mptcp_recvmsg,
14c441b5 3726 .release_cb = mptcp_release_cb,
2c5ebd00
PA		 3727 .hash = mptcp_hash,
3728 .unhash = mptcp_unhash,
cec37a6e 3729 .get_port = mptcp_get_port,
6511882c 3730 .forward_alloc_get = mptcp_forward_alloc_get,
d027236c 3731 .sockets_allocated = &mptcp_sockets_allocated,
0defbb0a 3732
d027236c 3733 .memory_allocated = &tcp_memory_allocated,
0defbb0a
ED		 3734 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
3735
d027236c 3736 .memory_pressure = &tcp_memory_pressure,
d027236c 3737 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
989ef49b 3738 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
d027236c 3739 .sysctl_mem = sysctl_tcp_mem,
f870fa0b 3740 .obj_size = sizeof(struct mptcp_sock),
2c5ebd00 3741 .slab_flags = SLAB_TYPESAFE_BY_RCU,
f870fa0b
MM		 3742 .no_autobind = true,
3743};
3744
2303f994
PK		 3745static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3746{
3747 struct mptcp_sock *msk = mptcp_sk(sock->sk);
8cf2ebdc 3748 struct sock *ssk, *sk = sock->sk;
8cf2ebdc 3749 int err = -EINVAL;
2303f994 3750
8cf2ebdc 3751 lock_sock(sk);
3f326a82
PA		 3752 ssk = __mptcp_nmpc_sk(msk);
3753 if (IS_ERR(ssk)) {
3754 err = PTR_ERR(ssk);
2303f994
PK		 3755 goto unlock;
3756 }
3757
8cf2ebdc
PA		 3758 if (sk->sk_family == AF_INET)
3759 err = inet_bind_sk(ssk, uaddr, addr_len);
3760#if IS_ENABLED(CONFIG_MPTCP_IPV6)
3761 else if (sk->sk_family == AF_INET6)
3762 err = inet6_bind_sk(ssk, uaddr, addr_len);
3763#endif
cf7da0d6 3764 if (!err)
8cf2ebdc 3765 mptcp_copy_inaddrs(sk, ssk);
2303f994
PK		 3766
3767unlock:
8cf2ebdc 3768 release_sock(sk);
2303f994
PK		 3769 return err;
3770}
3771
cf7da0d6
PK		 3772static int mptcp_listen(struct socket *sock, int backlog)
3773{
3774 struct mptcp_sock *msk = mptcp_sk(sock->sk);
cfdcfeed 3775 struct sock *sk = sock->sk;
40f56d0c 3776 struct sock *ssk;
cf7da0d6
PK		 3777 int err;
3778
3779 pr_debug("msk=%p", msk);
3780
cfdcfeed 3781 lock_sock(sk);
0226436a
PA		 3782
3783 err = -EINVAL;
3784 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
3785 goto unlock;
3786
3f326a82
PA		 3787 ssk = __mptcp_nmpc_sk(msk);
3788 if (IS_ERR(ssk)) {
3789 err = PTR_ERR(ssk);
cf7da0d6
PK		 3790 goto unlock;
3791 }
3792
cfdcfeed
MD		 3793 inet_sk_state_store(sk, TCP_LISTEN);
3794 sock_set_flag(sk, SOCK_RCU_FREE);
5e20087d 3795
40f56d0c
PA		 3796 lock_sock(ssk);
3797 err = __inet_listen_sk(ssk, backlog);
3798 release_sock(ssk);
3799 inet_sk_state_store(sk, inet_sk_state_load(ssk));
3800
c558246e
MD		 3801 if (!err) {
3802 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
40f56d0c
PA		 3803 mptcp_copy_inaddrs(sk, ssk);
3804 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED);
c558246e 3805 }
cf7da0d6
PK		 3806
3807unlock:
cfdcfeed 3808 release_sock(sk);
cf7da0d6
PK		 3809 return err;
3810}
3811
cf7da0d6
PK		 3812static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
3813 int flags, bool kern)
3814{
3815 struct mptcp_sock *msk = mptcp_sk(sock->sk);
1f6610b9 3816 struct sock *ssk, *newsk;
cf7da0d6
PK		 3817 int err;
3818
3819 pr_debug("msk=%p", msk);
3820
5b825727 3821 /* Buggy applications can call accept on socket states other then LISTEN
61761231
PA		 3822 * but no need to allocate the first subflow just to error out.
3823 */
1f6610b9
PA		 3824 ssk = READ_ONCE(msk->first);
3825 if (!ssk)
71ba088c 3826 return -EINVAL;
cf7da0d6 3827
1f6610b9 3828 newsk = mptcp_accept(ssk, flags, &err, kern);
e76c8ef5
PA		 3829 if (!newsk)
3830 return err;
3831
3832 lock_sock(newsk);
3833
3834 __inet_accept(sock, newsock, newsk);
3835 if (!mptcp_is_tcpsk(newsock->sk)) {
3836 struct mptcp_sock *msk = mptcp_sk(newsk);
cf7da0d6 3837 struct mptcp_subflow_context *subflow;
0397c6d8 3838
a5ef058d 3839 set_bit(SOCK_CUSTOM_SOCKOPT, &newsock->flags);
b6985b9b 3840 msk->in_accept_queue = 0;
a5ef058d 3841
cf7da0d6
PK		 3842 /* set ssk->sk_socket of accept()ed flows to mptcp socket.
3843 * This is needed so NOSPACE flag can be set from tcp stack.
3844 */
190f8b06 3845 mptcp_for_each_subflow(msk, subflow) {
cf7da0d6
PK		 3846 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
3847
3848 if (!ssk->sk_socket)
3849 mptcp_sock_graft(ssk, newsock);
3850 }
63740448
PA		 3851
3852 /* Do late cleanup for the first subflow as necessary. Also
3853 * deal with bad peers not doing a complete shutdown.
3854 */
39880bd8 3855 if (unlikely(inet_sk_state_load(msk->first) == TCP_CLOSE)) {
63740448
PA		 3856 __mptcp_close_ssk(newsk, msk->first,
3857 mptcp_subflow_ctx(msk->first), 0);
39880bd8 3858 if (unlikely(list_is_singular(&msk->conn_list)))
63740448
PA		 3859 inet_sk_state_store(newsk, TCP_CLOSE);
3860 }
cf7da0d6 3861 }
e76c8ef5 3862 release_sock(newsk);
cf7da0d6 3863
e76c8ef5 3864 return 0;
cf7da0d6
PK		 3865}
3866
8edf0864
FW		 3867static __poll_t mptcp_check_writeable(struct mptcp_sock *msk)
3868{
3869 struct sock *sk = (struct sock *)msk;
8edf0864 3870
8edf0864
FW		 3871 if (sk_stream_is_writeable(sk))
3872 return EPOLLOUT | EPOLLWRNORM;
3873
5cf92bba 3874 mptcp_set_nospace(sk);
6e628cd3
PA		 3875 smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */
3876 if (sk_stream_is_writeable(sk))
3877 return EPOLLOUT | EPOLLWRNORM;
8edf0864 3878
6e628cd3 3879 return 0;
8edf0864
FW		 3880}
3881
2303f994
PK		 3882static __poll_t mptcp_poll(struct file *file, struct socket *sock,
3883 struct poll_table_struct *wait)
3884{
1891c4a0 3885 struct sock *sk = sock->sk;
8ab183de 3886 struct mptcp_sock *msk;
2303f994 3887 __poll_t mask = 0;
6b9831bf 3888 u8 shutdown;
8a05661b 3889 int state;
2303f994 3890
1891c4a0 3891 msk = mptcp_sk(sk);
1891c4a0 3892 sock_poll_wait(file, sock, wait);
1891c4a0 3893
8a05661b 3894 state = inet_sk_state_load(sk);
6719331c 3895 pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags);
71ba088c 3896 if (state == TCP_LISTEN) {
5426a4ef 3897 struct sock *ssk = READ_ONCE(msk->first);
5b825727 3898
5426a4ef 3899 if (WARN_ON_ONCE(!ssk))
71ba088c
PA		 3900 return 0;
3901
5426a4ef 3902 return inet_csk_listen_poll(ssk);
71ba088c 3903 }
8a05661b 3904
6b9831bf
PA		 3905 shutdown = READ_ONCE(sk->sk_shutdown);
3906 if (shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
3907 mask |= EPOLLHUP;
3908 if (shutdown & RCV_SHUTDOWN)
3909 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
3910
8a05661b
PA		 3911 if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) {
3912 mask |= mptcp_check_readable(msk);
6b9831bf
PA		 3913 if (shutdown & SEND_SHUTDOWN)
3914 mask |= EPOLLOUT | EPOLLWRNORM;
3915 else
3916 mask |= mptcp_check_writeable(msk);
08e39c0d
ED		 3917 } else if (state == TCP_SYN_SENT &&
3918 inet_test_bit(DEFER_CONNECT, sk)) {
a42cf9d1
BH		 3919 /* cf tcp_poll() note about TFO */
3920 mask |= EPOLLOUT | EPOLLWRNORM;
8a05661b 3921 }
1891c4a0 3922
d89e3ed7 3923 /* This barrier is coupled with smp_wmb() in __mptcp_error_report() */
15cc1045 3924 smp_rmb();
9ae8e5ad 3925 if (READ_ONCE(sk->sk_err))
15cc1045
PA		 3926 mask |= EPOLLERR;
3927
2303f994
PK		 3928 return mask;
3929}
3930
e42f1ac6
FW		 3931static const struct proto_ops mptcp_stream_ops = {
3932 .family = PF_INET,
3933 .owner = THIS_MODULE,
0a3cc579 3934 .release = inet_release,
e42f1ac6 3935 .bind = mptcp_bind,
786fc124 3936 .connect = inet_stream_connect,
e42f1ac6
FW		 3937 .socketpair = sock_no_socketpair,
3938 .accept = mptcp_stream_accept,
d2f77c53 3939 .getname = inet_getname,
e42f1ac6
FW		 3940 .poll = mptcp_poll,
3941 .ioctl = inet_ioctl,
3942 .gettstamp = sock_gettstamp,
3943 .listen = mptcp_listen,
76e2a55d 3944 .shutdown = inet_shutdown,
e42f1ac6
FW		 3945 .setsockopt = sock_common_setsockopt,
3946 .getsockopt = sock_common_getsockopt,
3947 .sendmsg = inet_sendmsg,
3948 .recvmsg = inet_recvmsg,
3949 .mmap = sock_no_mmap,
e42f1ac6 3950};
2303f994 3951
f870fa0b
MM		 3952static struct inet_protosw mptcp_protosw = {
3953 .type = SOCK_STREAM,
3954 .protocol = IPPROTO_MPTCP,
3955 .prot = &mptcp_prot,
2303f994
PK		 3956 .ops = &mptcp_stream_ops,
3957 .flags = INET_PROTOSW_ICSK,
f870fa0b
MM		 3958};
3959
b19bc294
PA		 3960static int mptcp_napi_poll(struct napi_struct *napi, int budget)
3961{
3962 struct mptcp_delegated_action *delegated;
3963 struct mptcp_subflow_context *subflow;
3964 int work_done = 0;
3965
3966 delegated = container_of(napi, struct mptcp_delegated_action, napi);
3967 while ((subflow = mptcp_subflow_delegated_next(delegated)) != NULL) {
3968 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
3969
3970 bh_lock_sock_nested(ssk);
a5efdbce
PA		 3971 if (!sock_owned_by_user(ssk)) {
3972 mptcp_subflow_process_delegated(ssk, xchg(&subflow->delegated_status, 0));
3973 } else {
3974 /* tcp_release_cb_override already processed
3975 * the action or will do at next release_sock().
3976 * In both case must dequeue the subflow here - on the same
3977 * CPU that scheduled it.
3978 */
3979 smp_wmb();
3980 clear_bit(MPTCP_DELEGATE_SCHEDULED, &subflow->delegated_status);
3981 }
b19bc294
PA		 3982 bh_unlock_sock(ssk);
3983 sock_put(ssk);
3984
3985 if (++work_done == budget)
3986 return budget;
3987 }
3988
3989 /* always provide a 0 'work_done' argument, so that napi_complete_done
3990 * will not try accessing the NULL napi->dev ptr
3991 */
3992 napi_complete_done(napi, 0);
3993 return work_done;
3994}
3995
d39dceca 3996void __init mptcp_proto_init(void)
f870fa0b 3997{
b19bc294
PA		 3998 struct mptcp_delegated_action *delegated;
3999 int cpu;
4000
2303f994 4001 mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;
2303f994 4002
d027236c
PA		 4003 if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL))
4004 panic("Failed to allocate MPTCP pcpu counter\n");
4005
b19bc294
PA		 4006 init_dummy_netdev(&mptcp_napi_dev);
4007 for_each_possible_cpu(cpu) {
4008 delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu);
4009 INIT_LIST_HEAD(&delegated->head);
16d083e2
JK		 4010 netif_napi_add_tx(&mptcp_napi_dev, &delegated->napi,
4011 mptcp_napi_poll);
b19bc294
PA		 4012 napi_enable(&delegated->napi);
4013 }
4014
2303f994 4015 mptcp_subflow_init();
1b1c7a0e 4016 mptcp_pm_init();
ed1ad86b 4017 mptcp_sched_init();
2c5ebd00 4018 mptcp_token_init();
2303f994 4019
f870fa0b
MM		 4020 if (proto_register(&mptcp_prot, 1) != 0)
4021 panic("Failed to register MPTCP proto.\n");
4022
4023 inet_register_protosw(&mptcp_protosw);
6771bfd9
FW		 4024
4025 BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, cb));
f870fa0b
MM		 4026}
4027
4028#if IS_ENABLED(CONFIG_MPTCP_IPV6)
e42f1ac6
FW		 4029static const struct proto_ops mptcp_v6_stream_ops = {
4030 .family = PF_INET6,
4031 .owner = THIS_MODULE,
0a3cc579 4032 .release = inet6_release,
e42f1ac6 4033 .bind = mptcp_bind,
786fc124 4034 .connect = inet_stream_connect,
e42f1ac6
FW		 4035 .socketpair = sock_no_socketpair,
4036 .accept = mptcp_stream_accept,
d2f77c53 4037 .getname = inet6_getname,
e42f1ac6
FW		 4038 .poll = mptcp_poll,
4039 .ioctl = inet6_ioctl,
4040 .gettstamp = sock_gettstamp,
4041 .listen = mptcp_listen,
76e2a55d 4042 .shutdown = inet_shutdown,
e42f1ac6
FW		 4043 .setsockopt = sock_common_setsockopt,
4044 .getsockopt = sock_common_getsockopt,
4045 .sendmsg = inet6_sendmsg,
4046 .recvmsg = inet6_recvmsg,
4047 .mmap = sock_no_mmap,
e42f1ac6 4048#ifdef CONFIG_COMPAT
3986912f 4049 .compat_ioctl = inet6_compat_ioctl,
e42f1ac6
FW		 4050#endif
4051};
4052
f870fa0b
MM		 4053static struct proto mptcp_v6_prot;
4054
4055static struct inet_protosw mptcp_v6_protosw = {
4056 .type = SOCK_STREAM,
4057 .protocol = IPPROTO_MPTCP,
4058 .prot = &mptcp_v6_prot,
2303f994 4059 .ops = &mptcp_v6_stream_ops,
f870fa0b
MM		 4060 .flags = INET_PROTOSW_ICSK,
4061};
4062
d39dceca 4063int __init mptcp_proto_v6_init(void)
f870fa0b
MM		 4064{
4065 int err;
4066
4067 mptcp_v6_prot = mptcp_prot;
4068 strcpy(mptcp_v6_prot.name, "MPTCPv6");
4069 mptcp_v6_prot.slab = NULL;
b0519de8 4070 mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock);
f5f80e32 4071 mptcp_v6_prot.ipv6_pinfo_offset = offsetof(struct mptcp6_sock, np);
f870fa0b
MM		 4072
4073 err = proto_register(&mptcp_v6_prot, 1);
4074 if (err)
4075 return err;
4076
4077 err = inet6_register_protosw(&mptcp_v6_protosw);
4078 if (err)
4079 proto_unregister(&mptcp_v6_prot);
4080
4081 return err;
4082}
4083#endif
Linux 6.x block layer and io_uring tree(s)