1/* SPDX-License-Identifier: GPL-2.0 */
2/* Multipath TCP
3 *
4 * Copyright (c) 2017 - 2019, Intel Corporation.
5 */
6
7#ifndef __MPTCP_PROTOCOL_H
8#define __MPTCP_PROTOCOL_H
9
10#include <linux/random.h>
11#include <net/tcp.h>
12#include <net/inet_connection_sock.h>
13#include <uapi/linux/mptcp.h>
14#include <net/genetlink.h>
15
16#include "mptcp_pm_gen.h"
17
18#define MPTCP_SUPPORTED_VERSION 1
19
20/* MPTCP option bits */
21#define OPTION_MPTCP_MPC_SYN BIT(0)
22#define OPTION_MPTCP_MPC_SYNACK BIT(1)
23#define OPTION_MPTCP_MPC_ACK BIT(2)
24#define OPTION_MPTCP_MPJ_SYN BIT(3)
25#define OPTION_MPTCP_MPJ_SYNACK BIT(4)
26#define OPTION_MPTCP_MPJ_ACK BIT(5)
27#define OPTION_MPTCP_ADD_ADDR BIT(6)
28#define OPTION_MPTCP_RM_ADDR BIT(7)
29#define OPTION_MPTCP_FASTCLOSE BIT(8)
30#define OPTION_MPTCP_PRIO BIT(9)
31#define OPTION_MPTCP_RST BIT(10)
32#define OPTION_MPTCP_DSS BIT(11)
33#define OPTION_MPTCP_FAIL BIT(12)
34
35#define OPTION_MPTCP_CSUMREQD BIT(13)
36
37#define OPTIONS_MPTCP_MPC (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
38 OPTION_MPTCP_MPC_ACK)
39#define OPTIONS_MPTCP_MPJ (OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
40 OPTION_MPTCP_MPJ_ACK)
41
42/* MPTCP option subtypes */
43#define MPTCPOPT_MP_CAPABLE 0
44#define MPTCPOPT_MP_JOIN 1
45#define MPTCPOPT_DSS 2
46#define MPTCPOPT_ADD_ADDR 3
47#define MPTCPOPT_RM_ADDR 4
48#define MPTCPOPT_MP_PRIO 5
49#define MPTCPOPT_MP_FAIL 6
50#define MPTCPOPT_MP_FASTCLOSE 7
51#define MPTCPOPT_RST 8
52
53/* MPTCP suboption lengths */
54#define TCPOLEN_MPTCP_MPC_SYN 4
55#define TCPOLEN_MPTCP_MPC_SYNACK 12
56#define TCPOLEN_MPTCP_MPC_ACK 20
57#define TCPOLEN_MPTCP_MPC_ACK_DATA 22
58#define TCPOLEN_MPTCP_MPJ_SYN 12
59#define TCPOLEN_MPTCP_MPJ_SYNACK 16
60#define TCPOLEN_MPTCP_MPJ_ACK 24
61#define TCPOLEN_MPTCP_DSS_BASE 4
62#define TCPOLEN_MPTCP_DSS_ACK32 4
63#define TCPOLEN_MPTCP_DSS_ACK64 8
64#define TCPOLEN_MPTCP_DSS_MAP32 10
65#define TCPOLEN_MPTCP_DSS_MAP64 14
66#define TCPOLEN_MPTCP_DSS_CHECKSUM 2
67#define TCPOLEN_MPTCP_ADD_ADDR 16
68#define TCPOLEN_MPTCP_ADD_ADDR_PORT 18
69#define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
70#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10
71#define TCPOLEN_MPTCP_ADD_ADDR6 28
72#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30
73#define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
74#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22
75#define TCPOLEN_MPTCP_PORT_LEN 2
76#define TCPOLEN_MPTCP_PORT_ALIGN 2
77#define TCPOLEN_MPTCP_RM_ADDR_BASE 3
78#define TCPOLEN_MPTCP_PRIO 3
79#define TCPOLEN_MPTCP_PRIO_ALIGN 4
80#define TCPOLEN_MPTCP_FASTCLOSE 12
81#define TCPOLEN_MPTCP_RST 4
82#define TCPOLEN_MPTCP_FAIL 12
83
84#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
85
86/* MPTCP MP_JOIN flags */
87#define MPTCPOPT_BACKUP BIT(0)
88#define MPTCPOPT_THMAC_LEN 8
89
90/* MPTCP MP_CAPABLE flags */
91#define MPTCP_VERSION_MASK (0x0F)
92#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
93#define MPTCP_CAP_EXTENSIBILITY BIT(6)
94#define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
95#define MPTCP_CAP_HMAC_SHA256 BIT(0)
96#define MPTCP_CAP_FLAG_MASK (0x1F)
97
98/* MPTCP DSS flags */
99#define MPTCP_DSS_DATA_FIN BIT(4)
100#define MPTCP_DSS_DSN64 BIT(3)
101#define MPTCP_DSS_HAS_MAP BIT(2)
102#define MPTCP_DSS_ACK64 BIT(1)
103#define MPTCP_DSS_HAS_ACK BIT(0)
104#define MPTCP_DSS_FLAG_MASK (0x1F)
105
106/* MPTCP ADD_ADDR flags */
107#define MPTCP_ADDR_ECHO BIT(0)
108
109/* MPTCP MP_PRIO flags */
110#define MPTCP_PRIO_BKUP BIT(0)
111
112/* MPTCP TCPRST flags */
113#define MPTCP_RST_TRANSIENT BIT(0)
114
115/* MPTCP socket atomic flags */
116#define MPTCP_NOSPACE 1
117#define MPTCP_WORK_RTX 2
118#define MPTCP_FALLBACK_DONE 4
119#define MPTCP_WORK_CLOSE_SUBFLOW 5
120
121/* MPTCP socket release cb flags */
122#define MPTCP_PUSH_PENDING 1
123#define MPTCP_CLEAN_UNA 2
124#define MPTCP_ERROR_REPORT 3
125#define MPTCP_RETRANSMIT 4
126#define MPTCP_FLUSH_JOIN_LIST 5
127#define MPTCP_CONNECTED 6
128#define MPTCP_SYNC_SNDBUF 7
129
130struct mptcp_skb_cb {
131 u64 map_seq;
132 u64 end_seq;
133 u32 offset;
134 u8 has_rxtstamp:1;
135};
136
137#define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0]))
138
139static inline bool before64(__u64 seq1, __u64 seq2)
140{
141 return (__s64)(seq1 - seq2) < 0;
142}
143
144#define after64(seq2, seq1) before64(seq1, seq2)
145
146struct mptcp_options_received {
147 u64 sndr_key;
148 u64 rcvr_key;
149 u64 data_ack;
150 u64 data_seq;
151 u32 subflow_seq;
152 u16 data_len;
153 __sum16 csum;
154 u16 suboptions;
155 u32 token;
156 u32 nonce;
157 u16 use_map:1,
158 dsn64:1,
159 data_fin:1,
160 use_ack:1,
161 ack64:1,
162 mpc_map:1,
163 reset_reason:4,
164 reset_transient:1,
165 echo:1,
166 backup:1,
167 deny_join_id0:1,
168 __unused:2;
169 u8 join_id;
170 u64 thmac;
171 u8 hmac[MPTCPOPT_HMAC_LEN];
172 struct mptcp_addr_info addr;
173 struct mptcp_rm_list rm_list;
174 u64 ahmac;
175 u64 fail_seq;
176};
177
178static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
179{
180 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
181 ((nib & 0xF) << 8) | field);
182}
183
184enum mptcp_pm_status {
185 MPTCP_PM_ADD_ADDR_RECEIVED,
186 MPTCP_PM_ADD_ADDR_SEND_ACK,
187 MPTCP_PM_RM_ADDR_RECEIVED,
188 MPTCP_PM_ESTABLISHED,
189 MPTCP_PM_SUBFLOW_ESTABLISHED,
190 MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */
191 MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
192 * accounted int id_avail_bitmap
193 */
194};
195
196enum mptcp_pm_type {
197 MPTCP_PM_TYPE_KERNEL = 0,
198 MPTCP_PM_TYPE_USERSPACE,
199
200 __MPTCP_PM_TYPE_NR,
201 __MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
202};
203
204/* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
205#define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
206
207enum mptcp_addr_signal_status {
208 MPTCP_ADD_ADDR_SIGNAL,
209 MPTCP_ADD_ADDR_ECHO,
210 MPTCP_RM_ADDR_SIGNAL,
211};
212
213/* max value of mptcp_addr_info.id */
214#define MPTCP_PM_MAX_ADDR_ID U8_MAX
215
216struct mptcp_pm_data {
217 struct mptcp_addr_info local;
218 struct mptcp_addr_info remote;
219 struct list_head anno_list;
220 struct list_head userspace_pm_local_addr_list;
221
222 spinlock_t lock; /*protects the whole PM data */
223
224 u8 addr_signal;
225 bool server_side;
226 bool work_pending;
227 bool accept_addr;
228 bool accept_subflow;
229 bool remote_deny_join_id0;
230 u8 add_addr_signaled;
231 u8 add_addr_accepted;
232 u8 local_addr_used;
233 u8 pm_type;
234 u8 subflows;
235 u8 status;
236 DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
237 struct mptcp_rm_list rm_list_tx;
238 struct mptcp_rm_list rm_list_rx;
239};
240
241struct mptcp_pm_addr_entry {
242 struct list_head list;
243 struct mptcp_addr_info addr;
244 u8 flags;
245 int ifindex;
246 struct socket *lsk;
247};
248
249struct mptcp_data_frag {
250 struct list_head list;
251 u64 data_seq;
252 u16 data_len;
253 u16 offset;
254 u16 overhead;
255 u16 already_sent;
256 struct page *page;
257};
258
259/* MPTCP connection sock */
260struct mptcp_sock {
261 /* inet_connection_sock must be the first member */
262 struct inet_connection_sock sk;
263 u64 local_key;
264 u64 remote_key;
265 u64 write_seq;
266 u64 bytes_sent;
267 u64 snd_nxt;
268 u64 bytes_received;
269 u64 ack_seq;
270 atomic64_t rcv_wnd_sent;
271 u64 rcv_data_fin_seq;
272 u64 bytes_retrans;
273 u64 bytes_consumed;
274 int rmem_fwd_alloc;
275 int snd_burst;
276 int old_wspace;
277 u64 recovery_snd_nxt; /* in recovery mode accept up to this seq;
278 * recovery related fields are under data_lock
279 * protection
280 */
281 u64 bytes_acked;
282 u64 snd_una;
283 u64 wnd_end;
284 unsigned long timer_ival;
285 u32 token;
286 int rmem_released;
287 unsigned long flags;
288 unsigned long cb_flags;
289 unsigned long push_pending;
290 bool recovery; /* closing subflow write queue reinjected */
291 bool can_ack;
292 bool fully_established;
293 bool rcv_data_fin;
294 bool snd_data_fin_enable;
295 bool rcv_fastclose;
296 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
297 bool csum_enabled;
298 bool allow_infinite_fallback;
299 u8 mpc_endpoint_id;
300 u8 recvmsg_inq:1,
301 cork:1,
302 nodelay:1,
303 fastopening:1,
304 in_accept_queue:1,
305 free_first:1;
306 struct work_struct work;
307 struct sk_buff *ooo_last_skb;
308 struct rb_root out_of_order_queue;
309 struct sk_buff_head receive_queue;
310 struct list_head conn_list;
311 struct list_head rtx_queue;
312 struct mptcp_data_frag *first_pending;
313 struct list_head join_list;
314 struct sock *first; /* The mptcp ops can safely dereference, using suitable
315 * ONCE annotation, the subflow outside the socket
316 * lock as such sock is freed after close().
317 */
318 struct mptcp_pm_data pm;
319 struct mptcp_sched_ops *sched;
320 struct {
321 u32 space; /* bytes copied in last measurement window */
322 u32 copied; /* bytes copied in this measurement window */
323 u64 time; /* start time of measurement window */
324 u64 rtt_us; /* last maximum rtt of subflows */
325 } rcvq_space;
326 u8 scaling_ratio;
327
328 u32 subflow_id;
329 u32 setsockopt_seq;
330 char ca_name[TCP_CA_NAME_MAX];
331};
332
333#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
334#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
335
336#define mptcp_for_each_subflow(__msk, __subflow) \
337 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
338#define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp) \
339 list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
340
341static inline void msk_owned_by_me(const struct mptcp_sock *msk)
342{
343 sock_owned_by_me(sk: (const struct sock *)msk);
344}
345
346#define mptcp_sk(ptr) container_of_const(ptr, struct mptcp_sock, sk.icsk_inet.sk)
347
348/* the msk socket don't use the backlog, also account for the bulk
349 * free memory
350 */
351static inline int __mptcp_rmem(const struct sock *sk)
352{
353 return atomic_read(v: &sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
354}
355
356static inline int mptcp_win_from_space(const struct sock *sk, int space)
357{
358 return __tcp_win_from_space(mptcp_sk(sk)->scaling_ratio, space);
359}
360
361static inline int __mptcp_space(const struct sock *sk)
362{
363 return mptcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
364}
365
366static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
367{
368 const struct mptcp_sock *msk = mptcp_sk(sk);
369
370 return READ_ONCE(msk->first_pending);
371}
372
373static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
374{
375 struct mptcp_sock *msk = mptcp_sk(sk);
376 struct mptcp_data_frag *cur;
377
378 cur = msk->first_pending;
379 return list_is_last(list: &cur->list, head: &msk->rtx_queue) ? NULL :
380 list_next_entry(cur, list);
381}
382
383static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
384{
385 const struct mptcp_sock *msk = mptcp_sk(sk);
386
387 if (!msk->first_pending)
388 return NULL;
389
390 if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
391 return NULL;
392
393 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
394}
395
396static inline struct mptcp_data_frag *mptcp_rtx_head(struct sock *sk)
397{
398 struct mptcp_sock *msk = mptcp_sk(sk);
399
400 if (msk->snd_una == READ_ONCE(msk->snd_nxt))
401 return NULL;
402
403 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
404}
405
406struct csum_pseudo_header {
407 __be64 data_seq;
408 __be32 subflow_seq;
409 __be16 data_len;
410 __sum16 csum;
411};
412
413struct mptcp_subflow_request_sock {
414 struct tcp_request_sock sk;
415 u16 mp_capable : 1,
416 mp_join : 1,
417 backup : 1,
418 csum_reqd : 1,
419 allow_join_id0 : 1;
420 u8 local_id;
421 u8 remote_id;
422 u64 local_key;
423 u64 idsn;
424 u32 token;
425 u32 ssn_offset;
426 u64 thmac;
427 u32 local_nonce;
428 u32 remote_nonce;
429 struct mptcp_sock *msk;
430 struct hlist_nulls_node token_node;
431};
432
433static inline struct mptcp_subflow_request_sock *
434mptcp_subflow_rsk(const struct request_sock *rsk)
435{
436 return (struct mptcp_subflow_request_sock *)rsk;
437}
438
439struct mptcp_delegated_action {
440 struct napi_struct napi;
441 struct list_head head;
442};
443
444DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
445
446#define MPTCP_DELEGATE_SCHEDULED 0
447#define MPTCP_DELEGATE_SEND 1
448#define MPTCP_DELEGATE_ACK 2
449#define MPTCP_DELEGATE_SNDBUF 3
450
451#define MPTCP_DELEGATE_ACTIONS_MASK (~BIT(MPTCP_DELEGATE_SCHEDULED))
452/* MPTCP subflow context */
453struct mptcp_subflow_context {
454 struct list_head node;/* conn_list of subflows */
455
456 struct_group(reset,
457
458 unsigned long avg_pacing_rate; /* protected by msk socket lock */
459 u64 local_key;
460 u64 remote_key;
461 u64 idsn;
462 u64 map_seq;
463 u32 snd_isn;
464 u32 token;
465 u32 rel_write_seq;
466 u32 map_subflow_seq;
467 u32 ssn_offset;
468 u32 map_data_len;
469 __wsum map_data_csum;
470 u32 map_csum_len;
471 u32 request_mptcp : 1, /* send MP_CAPABLE */
472 request_join : 1, /* send MP_JOIN */
473 request_bkup : 1,
474 mp_capable : 1, /* remote is MPTCP capable */
475 mp_join : 1, /* remote is JOINing */
476 fully_established : 1, /* path validated */
477 pm_notified : 1, /* PM hook called for established status */
478 conn_finished : 1,
479 map_valid : 1,
480 map_csum_reqd : 1,
481 map_data_fin : 1,
482 mpc_map : 1,
483 backup : 1,
484 send_mp_prio : 1,
485 send_mp_fail : 1,
486 send_fastclose : 1,
487 send_infinite_map : 1,
488 remote_key_valid : 1, /* received the peer key from */
489 disposable : 1, /* ctx can be free at ulp release time */
490 stale : 1, /* unable to snd/rcv data, do not use for xmit */
491 local_id_valid : 1, /* local_id is correctly initialized */
492 valid_csum_seen : 1, /* at least one csum validated */
493 is_mptfo : 1, /* subflow is doing TFO */
494 __unused : 9;
495 bool data_avail;
496 bool scheduled;
497 u32 remote_nonce;
498 u64 thmac;
499 u32 local_nonce;
500 u32 remote_token;
501 union {
502 u8 hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */
503 u64 iasn; /* initial ack sequence number, MPC subflows only */
504 };
505 u8 local_id;
506 u8 remote_id;
507 u8 reset_seen:1;
508 u8 reset_transient:1;
509 u8 reset_reason:4;
510 u8 stale_count;
511
512 u32 subflow_id;
513
514 long delegated_status;
515 unsigned long fail_tout;
516
517 );
518
519 struct list_head delegated_node; /* link into delegated_action, protected by local BH */
520
521 u32 setsockopt_seq;
522 u32 stale_rcv_tstamp;
523 int cached_sndbuf; /* sndbuf size when last synced with the msk sndbuf,
524 * protected by the msk socket lock
525 */
526
527 struct sock *tcp_sock; /* tcp sk backpointer */
528 struct sock *conn; /* parent mptcp_sock */
529 const struct inet_connection_sock_af_ops *icsk_af_ops;
530 void (*tcp_state_change)(struct sock *sk);
531 void (*tcp_error_report)(struct sock *sk);
532
533 struct rcu_head rcu;
534};
535
536static inline struct mptcp_subflow_context *
537mptcp_subflow_ctx(const struct sock *sk)
538{
539 struct inet_connection_sock *icsk = inet_csk(sk);
540
541 /* Use RCU on icsk_ulp_data only for sock diag code */
542 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
543}
544
545static inline struct sock *
546mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
547{
548 return subflow->tcp_sock;
549}
550
551static inline void
552mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
553{
554 memset(&subflow->reset, 0, sizeof(subflow->reset));
555 subflow->request_mptcp = 1;
556}
557
558static inline u64
559mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
560{
561 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
562 subflow->ssn_offset -
563 subflow->map_subflow_seq;
564}
565
566static inline u64
567mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
568{
569 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
570}
571
572void mptcp_subflow_process_delegated(struct sock *ssk, long actions);
573
574static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
575{
576 long old, set_bits = BIT(MPTCP_DELEGATE_SCHEDULED) | BIT(action);
577 struct mptcp_delegated_action *delegated;
578 bool schedule;
579
580 /* the caller held the subflow bh socket lock */
581 lockdep_assert_in_softirq();
582
583 /* The implied barrier pairs with tcp_release_cb_override()
584 * mptcp_napi_poll(), and ensures the below list check sees list
585 * updates done prior to delegated status bits changes
586 */
587 old = set_mask_bits(&subflow->delegated_status, 0, set_bits);
588 if (!(old & BIT(MPTCP_DELEGATE_SCHEDULED))) {
589 if (WARN_ON_ONCE(!list_empty(&subflow->delegated_node)))
590 return;
591
592 delegated = this_cpu_ptr(&mptcp_delegated_actions);
593 schedule = list_empty(head: &delegated->head);
594 list_add_tail(new: &subflow->delegated_node, head: &delegated->head);
595 sock_hold(sk: mptcp_subflow_tcp_sock(subflow));
596 if (schedule)
597 napi_schedule(n: &delegated->napi);
598 }
599}
600
601static inline struct mptcp_subflow_context *
602mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
603{
604 struct mptcp_subflow_context *ret;
605
606 if (list_empty(head: &delegated->head))
607 return NULL;
608
609 ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
610 list_del_init(entry: &ret->delegated_node);
611 return ret;
612}
613
614int mptcp_is_enabled(const struct net *net);
615unsigned int mptcp_get_add_addr_timeout(const struct net *net);
616int mptcp_is_checksum_enabled(const struct net *net);
617int mptcp_allow_join_id0(const struct net *net);
618unsigned int mptcp_stale_loss_cnt(const struct net *net);
619unsigned int mptcp_close_timeout(const struct sock *sk);
620int mptcp_get_pm_type(const struct net *net);
621const char *mptcp_get_scheduler(const struct net *net);
622void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
623 const struct mptcp_options_received *mp_opt);
624bool __mptcp_retransmit_pending_data(struct sock *sk);
625void mptcp_check_and_set_pending(struct sock *sk);
626void __mptcp_push_pending(struct sock *sk, unsigned int flags);
627bool mptcp_subflow_data_available(struct sock *sk);
628void __init mptcp_subflow_init(void);
629void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
630void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
631 struct mptcp_subflow_context *subflow);
632void __mptcp_subflow_send_ack(struct sock *ssk);
633void mptcp_subflow_reset(struct sock *ssk);
634void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
635void mptcp_sock_graft(struct sock *sk, struct socket *parent);
636struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk);
637bool __mptcp_close(struct sock *sk, long timeout);
638void mptcp_cancel_work(struct sock *sk);
639void __mptcp_unaccepted_force_close(struct sock *sk);
640void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk);
641
642bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
643 const struct mptcp_addr_info *b, bool use_port);
644void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr);
645
646/* called with sk socket lock held */
647int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
648 const struct mptcp_addr_info *remote);
649int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,
650 struct socket **new_sock);
651void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
652 struct sockaddr_storage *addr,
653 unsigned short family);
654struct mptcp_sched_ops *mptcp_sched_find(const char *name);
655int mptcp_register_scheduler(struct mptcp_sched_ops *sched);
656void mptcp_unregister_scheduler(struct mptcp_sched_ops *sched);
657void mptcp_sched_init(void);
658int mptcp_init_sched(struct mptcp_sock *msk,
659 struct mptcp_sched_ops *sched);
660void mptcp_release_sched(struct mptcp_sock *msk);
661void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
662 bool scheduled);
663struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
664struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
665int mptcp_sched_get_send(struct mptcp_sock *msk);
666int mptcp_sched_get_retrans(struct mptcp_sock *msk);
667
668static inline u64 mptcp_data_avail(const struct mptcp_sock *msk)
669{
670 return READ_ONCE(msk->bytes_received) - READ_ONCE(msk->bytes_consumed);
671}
672
673static inline bool mptcp_epollin_ready(const struct sock *sk)
674{
675 /* mptcp doesn't have to deal with small skbs in the receive queue,
676 * at it can always coalesce them
677 */
678 return (mptcp_data_avail(mptcp_sk(sk)) >= sk->sk_rcvlowat) ||
679 (mem_cgroup_sockets_enabled && sk->sk_memcg &&
680 mem_cgroup_under_socket_pressure(memcg: sk->sk_memcg)) ||
681 READ_ONCE(tcp_memory_pressure);
682}
683
684int mptcp_set_rcvlowat(struct sock *sk, int val);
685
686static inline bool __tcp_can_send(const struct sock *ssk)
687{
688 /* only send if our side has not closed yet */
689 return ((1 << inet_sk_state_load(sk: ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
690}
691
692static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
693{
694 /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
695 if (subflow->request_join && !subflow->fully_established)
696 return false;
697
698 return __tcp_can_send(ssk: mptcp_subflow_tcp_sock(subflow));
699}
700
701void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
702
703bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
704
705void mptcp_subflow_drop_ctx(struct sock *ssk);
706
707static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
708 struct mptcp_subflow_context *ctx)
709{
710 sk->sk_data_ready = sock_def_readable;
711 sk->sk_state_change = ctx->tcp_state_change;
712 sk->sk_write_space = sk_stream_write_space;
713 sk->sk_error_report = ctx->tcp_error_report;
714
715 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
716}
717
718void __init mptcp_proto_init(void);
719#if IS_ENABLED(CONFIG_MPTCP_IPV6)
720int __init mptcp_proto_v6_init(void);
721#endif
722
723struct sock *mptcp_sk_clone_init(const struct sock *sk,
724 const struct mptcp_options_received *mp_opt,
725 struct sock *ssk,
726 struct request_sock *req);
727void mptcp_get_options(const struct sk_buff *skb,
728 struct mptcp_options_received *mp_opt);
729
730void mptcp_finish_connect(struct sock *sk);
731void __mptcp_set_connected(struct sock *sk);
732void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout);
733
734static inline void mptcp_stop_tout_timer(struct sock *sk)
735{
736 if (!inet_csk(sk)->icsk_mtup.probe_timestamp)
737 return;
738
739 sk_stop_timer(sk, timer: &sk->sk_timer);
740 inet_csk(sk)->icsk_mtup.probe_timestamp = 0;
741}
742
743static inline void mptcp_set_close_tout(struct sock *sk, unsigned long tout)
744{
745 /* avoid 0 timestamp, as that means no close timeout */
746 inet_csk(sk)->icsk_mtup.probe_timestamp = tout ? : 1;
747}
748
749static inline void mptcp_start_tout_timer(struct sock *sk)
750{
751 mptcp_set_close_tout(sk, tcp_jiffies32);
752 mptcp_reset_tout_timer(mptcp_sk(sk), fail_tout: 0);
753}
754
755static inline bool mptcp_is_fully_established(struct sock *sk)
756{
757 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
758 READ_ONCE(mptcp_sk(sk)->fully_established);
759}
760
761void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
762void mptcp_data_ready(struct sock *sk, struct sock *ssk);
763bool mptcp_finish_join(struct sock *sk);
764bool mptcp_schedule_work(struct sock *sk);
765int mptcp_setsockopt(struct sock *sk, int level, int optname,
766 sockptr_t optval, unsigned int optlen);
767int mptcp_getsockopt(struct sock *sk, int level, int optname,
768 char __user *optval, int __user *option);
769
770u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
771static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
772{
773 if (use_64bit)
774 return cur_seq;
775
776 return __mptcp_expand_seq(old_seq, cur_seq);
777}
778void __mptcp_check_push(struct sock *sk, struct sock *ssk);
779void __mptcp_data_acked(struct sock *sk);
780void __mptcp_error_report(struct sock *sk);
781bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
782static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
783{
784 return READ_ONCE(msk->snd_data_fin_enable) &&
785 READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
786}
787
788static inline void __mptcp_sync_sndbuf(struct sock *sk)
789{
790 struct mptcp_subflow_context *subflow;
791 int ssk_sndbuf, new_sndbuf;
792
793 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
794 return;
795
796 new_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[0];
797 mptcp_for_each_subflow(mptcp_sk(sk), subflow) {
798 ssk_sndbuf = READ_ONCE(mptcp_subflow_tcp_sock(subflow)->sk_sndbuf);
799
800 subflow->cached_sndbuf = ssk_sndbuf;
801 new_sndbuf += ssk_sndbuf;
802 }
803
804 /* the msk max wmem limit is <nr_subflows> * tcp wmem[2] */
805 WRITE_ONCE(sk->sk_sndbuf, new_sndbuf);
806}
807
808/* The called held both the msk socket and the subflow socket locks,
809 * possibly under BH
810 */
811static inline void __mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
812{
813 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk: ssk);
814
815 if (READ_ONCE(ssk->sk_sndbuf) != subflow->cached_sndbuf)
816 __mptcp_sync_sndbuf(sk);
817}
818
819/* the caller held only the subflow socket lock, either in process or
820 * BH context. Additionally this can be called under the msk data lock,
821 * so we can't acquire such lock here: let the delegate action acquires
822 * the needed locks in suitable order.
823 */
824static inline void mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
825{
826 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk: ssk);
827
828 if (likely(READ_ONCE(ssk->sk_sndbuf) == subflow->cached_sndbuf))
829 return;
830
831 local_bh_disable();
832 mptcp_subflow_delegate(subflow, MPTCP_DELEGATE_SNDBUF);
833 local_bh_enable();
834}
835
836static inline void mptcp_write_space(struct sock *sk)
837{
838 if (sk_stream_is_writeable(sk)) {
839 /* pairs with memory barrier in mptcp_poll */
840 smp_mb();
841 if (test_and_clear_bit(MPTCP_NOSPACE, addr: &mptcp_sk(sk)->flags))
842 sk_stream_write_space(sk);
843 }
844}
845
846void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
847
848#define MPTCP_TOKEN_MAX_RETRIES 4
849
850void __init mptcp_token_init(void);
851static inline void mptcp_token_init_request(struct request_sock *req)
852{
853 mptcp_subflow_rsk(rsk: req)->token_node.pprev = NULL;
854}
855
856int mptcp_token_new_request(struct request_sock *req);
857void mptcp_token_destroy_request(struct request_sock *req);
858int mptcp_token_new_connect(struct sock *ssk);
859void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
860 struct mptcp_sock *msk);
861bool mptcp_token_exists(u32 token);
862struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
863struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
864 long *s_num);
865void mptcp_token_destroy(struct mptcp_sock *msk);
866
867void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
868
869void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
870__sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
871
872void __init mptcp_pm_init(void);
873void mptcp_pm_data_init(struct mptcp_sock *msk);
874void mptcp_pm_data_reset(struct mptcp_sock *msk);
875int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
876 struct mptcp_addr_info *addr);
877int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
878 bool require_family,
879 struct mptcp_pm_addr_entry *entry);
880bool mptcp_pm_addr_families_match(const struct sock *sk,
881 const struct mptcp_addr_info *loc,
882 const struct mptcp_addr_info *rem);
883void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
884void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
885void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
886void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk);
887bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
888void mptcp_pm_connection_closed(struct mptcp_sock *msk);
889void mptcp_pm_subflow_established(struct mptcp_sock *msk);
890bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
891void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
892 const struct mptcp_subflow_context *subflow);
893void mptcp_pm_add_addr_received(const struct sock *ssk,
894 const struct mptcp_addr_info *addr);
895void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
896 const struct mptcp_addr_info *addr);
897void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
898void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
899void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
900 const struct mptcp_rm_list *rm_list);
901void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
902void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
903int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
904 struct mptcp_addr_info *addr,
905 struct mptcp_addr_info *rem,
906 u8 bkup);
907bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
908 const struct mptcp_addr_info *addr);
909void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
910bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
911struct mptcp_pm_add_entry *
912mptcp_pm_del_add_timer(struct mptcp_sock *msk,
913 const struct mptcp_addr_info *addr, bool check_id);
914struct mptcp_pm_add_entry *
915mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
916 const struct mptcp_addr_info *addr);
917int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
918 unsigned int id,
919 u8 *flags, int *ifindex);
920int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
921 u8 *flags, int *ifindex);
922int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
923 unsigned int id,
924 u8 *flags, int *ifindex);
925int mptcp_pm_set_flags(struct net *net, struct nlattr *token,
926 struct mptcp_pm_addr_entry *loc,
927 struct mptcp_pm_addr_entry *rem, u8 bkup);
928int mptcp_pm_nl_set_flags(struct net *net, struct mptcp_pm_addr_entry *addr, u8 bkup);
929int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
930 struct mptcp_pm_addr_entry *loc,
931 struct mptcp_pm_addr_entry *rem, u8 bkup);
932int mptcp_pm_announce_addr(struct mptcp_sock *msk,
933 const struct mptcp_addr_info *addr,
934 bool echo);
935int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
936int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
937void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list);
938void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
939 struct list_head *rm_list);
940
941void mptcp_free_local_addr_list(struct mptcp_sock *msk);
942
943void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
944 const struct sock *ssk, gfp_t gfp);
945void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
946void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
947void mptcp_event_pm_listener(const struct sock *ssk,
948 enum mptcp_event_type event);
949bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
950
951void mptcp_fastopen_gen_msk_ackseq(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
952 const struct mptcp_options_received *mp_opt);
953void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow,
954 struct request_sock *req);
955
956static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
957{
958 return READ_ONCE(msk->pm.addr_signal) &
959 (BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
960}
961
962static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
963{
964 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
965}
966
967static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
968{
969 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
970}
971
972static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
973{
974 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
975}
976
977static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
978{
979 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
980}
981
982static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
983{
984 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
985}
986
987static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
988{
989 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
990
991 if (family == AF_INET6)
992 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
993 if (!echo)
994 len += MPTCPOPT_THMAC_LEN;
995 /* account for 2 trailing 'nop' options */
996 if (port)
997 len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
998
999 return len;
1000}
1001
1002static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
1003{
1004 if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
1005 return -EINVAL;
1006
1007 return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
1008}
1009
1010bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
1011 unsigned int opt_size, unsigned int remaining,
1012 struct mptcp_addr_info *addr, bool *echo,
1013 bool *drop_other_suboptions);
1014bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
1015 struct mptcp_rm_list *rm_list);
1016int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
1017int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1018int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1019
1020void __init mptcp_pm_nl_init(void);
1021void mptcp_pm_nl_work(struct mptcp_sock *msk);
1022void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
1023 const struct mptcp_rm_list *rm_list);
1024unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
1025unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
1026unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
1027unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
1028
1029/* called under PM lock */
1030static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
1031{
1032 if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
1033 WRITE_ONCE(msk->pm.accept_subflow, true);
1034}
1035
1036static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
1037{
1038 spin_lock_bh(lock: &msk->pm.lock);
1039 __mptcp_pm_close_subflow(msk);
1040 spin_unlock_bh(lock: &msk->pm.lock);
1041}
1042
1043void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
1044void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
1045
1046static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
1047{
1048 return (struct mptcp_ext *)skb_ext_find(skb, id: SKB_EXT_MPTCP);
1049}
1050
1051void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
1052
1053static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
1054{
1055 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
1056}
1057
1058static inline bool mptcp_check_fallback(const struct sock *sk)
1059{
1060 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1061 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
1062
1063 return __mptcp_check_fallback(msk);
1064}
1065
1066static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
1067{
1068 if (__mptcp_check_fallback(msk)) {
1069 pr_debug("TCP fallback already done (msk=%p)", msk);
1070 return;
1071 }
1072 set_bit(MPTCP_FALLBACK_DONE, addr: &msk->flags);
1073}
1074
1075static inline void mptcp_do_fallback(struct sock *ssk)
1076{
1077 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk: ssk);
1078 struct sock *sk = subflow->conn;
1079 struct mptcp_sock *msk;
1080
1081 msk = mptcp_sk(sk);
1082 __mptcp_do_fallback(msk);
1083 if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
1084 gfp_t saved_allocation = ssk->sk_allocation;
1085
1086 /* we are in a atomic (BH) scope, override ssk default for data
1087 * fin allocation
1088 */
1089 ssk->sk_allocation = GFP_ATOMIC;
1090 ssk->sk_shutdown |= SEND_SHUTDOWN;
1091 tcp_shutdown(sk: ssk, SEND_SHUTDOWN);
1092 ssk->sk_allocation = saved_allocation;
1093 }
1094}
1095
1096#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
1097
1098static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
1099{
1100 struct mptcp_ext *mpext;
1101
1102 mpext = skb ? mptcp_get_ext(skb) : NULL;
1103 if (mpext && mpext->infinite_map)
1104 return true;
1105
1106 return false;
1107}
1108
1109static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
1110{
1111 return (subflow->request_mptcp || subflow->request_join);
1112}
1113
1114static inline bool subflow_simultaneous_connect(struct sock *sk)
1115{
1116 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1117
1118 return sk->sk_state == TCP_ESTABLISHED &&
1119 is_active_ssk(subflow) &&
1120 !subflow->conn_finished;
1121}
1122
1123#ifdef CONFIG_SYN_COOKIES
1124void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1125 struct sk_buff *skb);
1126bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1127 struct sk_buff *skb);
1128void __init mptcp_join_cookie_init(void);
1129#else
1130static inline void
1131subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1132 struct sk_buff *skb) {}
1133static inline bool
1134mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1135 struct sk_buff *skb)
1136{
1137 return false;
1138}
1139
1140static inline void mptcp_join_cookie_init(void) {}
1141#endif
1142
1143#endif /* __MPTCP_PROTOCOL_H */
1144

source code of linux/net/mptcp/protocol.h