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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_SYNC_STATE 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 bool recovery; /* closing subflow write queue reinjected */
290 bool can_ack;
291 bool fully_established;
292 bool rcv_data_fin;
293 bool snd_data_fin_enable;
294 bool rcv_fastclose;
295 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
296 bool csum_enabled;
297 bool allow_infinite_fallback;
298 u8 pending_state; /* A subflow asked to set this sk_state,
299 * protected by the msk data lock
300 */
301 u8 mpc_endpoint_id;
302 u8 recvmsg_inq:1,
303 cork:1,
304 nodelay:1,
305 fastopening:1,
306 in_accept_queue:1,
307 free_first:1,
308 rcvspace_init:1;
309 struct work_struct work;
310 struct sk_buff *ooo_last_skb;
311 struct rb_root out_of_order_queue;
312 struct sk_buff_head receive_queue;
313 struct list_head conn_list;
314 struct list_head rtx_queue;
315 struct mptcp_data_frag *first_pending;
316 struct list_head join_list;
317 struct sock *first; /* The mptcp ops can safely dereference, using suitable
318 * ONCE annotation, the subflow outside the socket
319 * lock as such sock is freed after close().
320 */
321 struct mptcp_pm_data pm;
322 struct mptcp_sched_ops *sched;
323 struct {
324 u32 space; /* bytes copied in last measurement window */
325 u32 copied; /* bytes copied in this measurement window */
326 u64 time; /* start time of measurement window */
327 u64 rtt_us; /* last maximum rtt of subflows */
328 } rcvq_space;
329 u8 scaling_ratio;
330
331 u32 subflow_id;
332 u32 setsockopt_seq;
333 char ca_name[TCP_CA_NAME_MAX];
334};
335
336#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
337#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
338
339#define mptcp_for_each_subflow(__msk, __subflow) \
340 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
341#define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp) \
342 list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
343
344static inline void msk_owned_by_me(const struct mptcp_sock *msk)
345{
346 sock_owned_by_me((const struct sock *)msk);
347}
348
349#define mptcp_sk(ptr) container_of_const(ptr, struct mptcp_sock, sk.icsk_inet.sk)
350
351/* the msk socket don't use the backlog, also account for the bulk
352 * free memory
353 */
354static inline int __mptcp_rmem(const struct sock *sk)
355{
356 return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
357}
358
359static inline int mptcp_win_from_space(const struct sock *sk, int space)
360{
361 return __tcp_win_from_space(mptcp_sk(sk)->scaling_ratio, space);
362}
363
364static inline int __mptcp_space(const struct sock *sk)
365{
366 return mptcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
367}
368
369static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
370{
371 const struct mptcp_sock *msk = mptcp_sk(sk);
372
373 return READ_ONCE(msk->first_pending);
374}
375
376static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
377{
378 struct mptcp_sock *msk = mptcp_sk(sk);
379 struct mptcp_data_frag *cur;
380
381 cur = msk->first_pending;
382 return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
383 list_next_entry(cur, list);
384}
385
386static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
387{
388 const struct mptcp_sock *msk = mptcp_sk(sk);
389
390 if (!msk->first_pending)
391 return NULL;
392
393 if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
394 return NULL;
395
396 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
397}
398
399static inline struct mptcp_data_frag *mptcp_rtx_head(struct sock *sk)
400{
401 struct mptcp_sock *msk = mptcp_sk(sk);
402
403 if (msk->snd_una == READ_ONCE(msk->snd_nxt))
404 return NULL;
405
406 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
407}
408
409struct csum_pseudo_header {
410 __be64 data_seq;
411 __be32 subflow_seq;
412 __be16 data_len;
413 __sum16 csum;
414};
415
416struct mptcp_subflow_request_sock {
417 struct tcp_request_sock sk;
418 u16 mp_capable : 1,
419 mp_join : 1,
420 backup : 1,
421 csum_reqd : 1,
422 allow_join_id0 : 1;
423 u8 local_id;
424 u8 remote_id;
425 u64 local_key;
426 u64 idsn;
427 u32 token;
428 u32 ssn_offset;
429 u64 thmac;
430 u32 local_nonce;
431 u32 remote_nonce;
432 struct mptcp_sock *msk;
433 struct hlist_nulls_node token_node;
434};
435
436static inline struct mptcp_subflow_request_sock *
437mptcp_subflow_rsk(const struct request_sock *rsk)
438{
439 return (struct mptcp_subflow_request_sock *)rsk;
440}
441
442struct mptcp_delegated_action {
443 struct napi_struct napi;
444 struct list_head head;
445};
446
447DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
448
449#define MPTCP_DELEGATE_SCHEDULED 0
450#define MPTCP_DELEGATE_SEND 1
451#define MPTCP_DELEGATE_ACK 2
452#define MPTCP_DELEGATE_SNDBUF 3
453
454#define MPTCP_DELEGATE_ACTIONS_MASK (~BIT(MPTCP_DELEGATE_SCHEDULED))
455/* MPTCP subflow context */
456struct mptcp_subflow_context {
457 struct list_head node;/* conn_list of subflows */
458
459 struct_group(reset,
460
461 unsigned long avg_pacing_rate; /* protected by msk socket lock */
462 u64 local_key;
463 u64 remote_key;
464 u64 idsn;
465 u64 map_seq;
466 u32 snd_isn;
467 u32 token;
468 u32 rel_write_seq;
469 u32 map_subflow_seq;
470 u32 ssn_offset;
471 u32 map_data_len;
472 __wsum map_data_csum;
473 u32 map_csum_len;
474 u32 request_mptcp : 1, /* send MP_CAPABLE */
475 request_join : 1, /* send MP_JOIN */
476 request_bkup : 1,
477 mp_capable : 1, /* remote is MPTCP capable */
478 mp_join : 1, /* remote is JOINing */
479 fully_established : 1, /* path validated */
480 pm_notified : 1, /* PM hook called for established status */
481 conn_finished : 1,
482 map_valid : 1,
483 map_csum_reqd : 1,
484 map_data_fin : 1,
485 mpc_map : 1,
486 backup : 1,
487 send_mp_prio : 1,
488 send_mp_fail : 1,
489 send_fastclose : 1,
490 send_infinite_map : 1,
491 remote_key_valid : 1, /* received the peer key from */
492 disposable : 1, /* ctx can be free at ulp release time */
493 stale : 1, /* unable to snd/rcv data, do not use for xmit */
494 valid_csum_seen : 1, /* at least one csum validated */
495 is_mptfo : 1, /* subflow is doing TFO */
496 __unused : 10;
497 bool data_avail;
498 bool scheduled;
499 u32 remote_nonce;
500 u64 thmac;
501 u32 local_nonce;
502 u32 remote_token;
503 union {
504 u8 hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */
505 u64 iasn; /* initial ack sequence number, MPC subflows only */
506 };
507 s16 local_id; /* if negative not initialized yet */
508 u8 remote_id;
509 u8 reset_seen:1;
510 u8 reset_transient:1;
511 u8 reset_reason:4;
512 u8 stale_count;
513
514 u32 subflow_id;
515
516 long delegated_status;
517 unsigned long fail_tout;
518
519 );
520
521 struct list_head delegated_node; /* link into delegated_action, protected by local BH */
522
523 u32 setsockopt_seq;
524 u32 stale_rcv_tstamp;
525 int cached_sndbuf; /* sndbuf size when last synced with the msk sndbuf,
526 * protected by the msk socket lock
527 */
528
529 struct sock *tcp_sock; /* tcp sk backpointer */
530 struct sock *conn; /* parent mptcp_sock */
531 const struct inet_connection_sock_af_ops *icsk_af_ops;
532 void (*tcp_state_change)(struct sock *sk);
533 void (*tcp_error_report)(struct sock *sk);
534
535 struct rcu_head rcu;
536};
537
538static inline struct mptcp_subflow_context *
539mptcp_subflow_ctx(const struct sock *sk)
540{
541 struct inet_connection_sock *icsk = inet_csk(sk);
542
543 /* Use RCU on icsk_ulp_data only for sock diag code */
544 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
545}
546
547static inline struct sock *
548mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
549{
550 return subflow->tcp_sock;
551}
552
553static inline void
554mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
555{
556 memset(&subflow->reset, 0, sizeof(subflow->reset));
557 subflow->request_mptcp = 1;
558 WRITE_ONCE(subflow->local_id, -1);
559}
560
561static inline u64
562mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
563{
564 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
565 subflow->ssn_offset -
566 subflow->map_subflow_seq;
567}
568
569static inline u64
570mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
571{
572 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
573}
574
575void mptcp_subflow_process_delegated(struct sock *ssk, long actions);
576
577static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
578{
579 long old, set_bits = BIT(MPTCP_DELEGATE_SCHEDULED) | BIT(action);
580 struct mptcp_delegated_action *delegated;
581 bool schedule;
582
583 /* the caller held the subflow bh socket lock */
584 lockdep_assert_in_softirq();
585
586 /* The implied barrier pairs with tcp_release_cb_override()
587 * mptcp_napi_poll(), and ensures the below list check sees list
588 * updates done prior to delegated status bits changes
589 */
590 old = set_mask_bits(&subflow->delegated_status, 0, set_bits);
591 if (!(old & BIT(MPTCP_DELEGATE_SCHEDULED))) {
592 if (WARN_ON_ONCE(!list_empty(&subflow->delegated_node)))
593 return;
594
595 delegated = this_cpu_ptr(&mptcp_delegated_actions);
596 schedule = list_empty(&delegated->head);
597 list_add_tail(&subflow->delegated_node, &delegated->head);
598 sock_hold(mptcp_subflow_tcp_sock(subflow));
599 if (schedule)
600 napi_schedule(&delegated->napi);
601 }
602}
603
604static inline struct mptcp_subflow_context *
605mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
606{
607 struct mptcp_subflow_context *ret;
608
609 if (list_empty(&delegated->head))
610 return NULL;
611
612 ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
613 list_del_init(&ret->delegated_node);
614 return ret;
615}
616
617int mptcp_is_enabled(const struct net *net);
618unsigned int mptcp_get_add_addr_timeout(const struct net *net);
619int mptcp_is_checksum_enabled(const struct net *net);
620int mptcp_allow_join_id0(const struct net *net);
621unsigned int mptcp_stale_loss_cnt(const struct net *net);
622unsigned int mptcp_close_timeout(const struct sock *sk);
623int mptcp_get_pm_type(const struct net *net);
624const char *mptcp_get_scheduler(const struct net *net);
625void __mptcp_subflow_fully_established(struct mptcp_sock *msk,
626 struct mptcp_subflow_context *subflow,
627 const struct mptcp_options_received *mp_opt);
628bool __mptcp_retransmit_pending_data(struct sock *sk);
629void mptcp_check_and_set_pending(struct sock *sk);
630void __mptcp_push_pending(struct sock *sk, unsigned int flags);
631bool mptcp_subflow_data_available(struct sock *sk);
632void __init mptcp_subflow_init(void);
633void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
634void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
635 struct mptcp_subflow_context *subflow);
636void __mptcp_subflow_send_ack(struct sock *ssk);
637void mptcp_subflow_reset(struct sock *ssk);
638void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
639void mptcp_sock_graft(struct sock *sk, struct socket *parent);
640struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk);
641bool __mptcp_close(struct sock *sk, long timeout);
642void mptcp_cancel_work(struct sock *sk);
643void __mptcp_unaccepted_force_close(struct sock *sk);
644void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk);
645void mptcp_set_state(struct sock *sk, int state);
646
647bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
648 const struct mptcp_addr_info *b, bool use_port);
649void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr);
650
651/* called with sk socket lock held */
652int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
653 const struct mptcp_addr_info *remote);
654int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,
655 struct socket **new_sock);
656void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
657 struct sockaddr_storage *addr,
658 unsigned short family);
659struct mptcp_sched_ops *mptcp_sched_find(const char *name);
660int mptcp_register_scheduler(struct mptcp_sched_ops *sched);
661void mptcp_unregister_scheduler(struct mptcp_sched_ops *sched);
662void mptcp_sched_init(void);
663int mptcp_init_sched(struct mptcp_sock *msk,
664 struct mptcp_sched_ops *sched);
665void mptcp_release_sched(struct mptcp_sock *msk);
666void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
667 bool scheduled);
668struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
669struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
670int mptcp_sched_get_send(struct mptcp_sock *msk);
671int mptcp_sched_get_retrans(struct mptcp_sock *msk);
672
673static inline u64 mptcp_data_avail(const struct mptcp_sock *msk)
674{
675 return READ_ONCE(msk->bytes_received) - READ_ONCE(msk->bytes_consumed);
676}
677
678static inline bool mptcp_epollin_ready(const struct sock *sk)
679{
680 /* mptcp doesn't have to deal with small skbs in the receive queue,
681 * at it can always coalesce them
682 */
683 return (mptcp_data_avail(mptcp_sk(sk)) >= sk->sk_rcvlowat) ||
684 (mem_cgroup_sockets_enabled && sk->sk_memcg &&
685 mem_cgroup_under_socket_pressure(sk->sk_memcg)) ||
686 READ_ONCE(tcp_memory_pressure);
687}
688
689int mptcp_set_rcvlowat(struct sock *sk, int val);
690
691static inline bool __tcp_can_send(const struct sock *ssk)
692{
693 /* only send if our side has not closed yet */
694 return ((1 << inet_sk_state_load(ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
695}
696
697static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
698{
699 /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
700 if (subflow->request_join && !subflow->fully_established)
701 return false;
702
703 return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
704}
705
706void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
707
708bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
709
710void mptcp_subflow_drop_ctx(struct sock *ssk);
711
712static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
713 struct mptcp_subflow_context *ctx)
714{
715 sk->sk_data_ready = sock_def_readable;
716 sk->sk_state_change = ctx->tcp_state_change;
717 sk->sk_write_space = sk_stream_write_space;
718 sk->sk_error_report = ctx->tcp_error_report;
719
720 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
721}
722
723void __init mptcp_proto_init(void);
724#if IS_ENABLED(CONFIG_MPTCP_IPV6)
725int __init mptcp_proto_v6_init(void);
726#endif
727
728struct sock *mptcp_sk_clone_init(const struct sock *sk,
729 const struct mptcp_options_received *mp_opt,
730 struct sock *ssk,
731 struct request_sock *req);
732void mptcp_get_options(const struct sk_buff *skb,
733 struct mptcp_options_received *mp_opt);
734
735void mptcp_finish_connect(struct sock *sk);
736void __mptcp_sync_state(struct sock *sk, int state);
737void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout);
738
739static inline void mptcp_stop_tout_timer(struct sock *sk)
740{
741 if (!inet_csk(sk)->icsk_mtup.probe_timestamp)
742 return;
743
744 sk_stop_timer(sk, &sk->sk_timer);
745 inet_csk(sk)->icsk_mtup.probe_timestamp = 0;
746}
747
748static inline void mptcp_set_close_tout(struct sock *sk, unsigned long tout)
749{
750 /* avoid 0 timestamp, as that means no close timeout */
751 inet_csk(sk)->icsk_mtup.probe_timestamp = tout ? : 1;
752}
753
754static inline void mptcp_start_tout_timer(struct sock *sk)
755{
756 mptcp_set_close_tout(sk, tcp_jiffies32);
757 mptcp_reset_tout_timer(mptcp_sk(sk), 0);
758}
759
760static inline bool mptcp_is_fully_established(struct sock *sk)
761{
762 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
763 READ_ONCE(mptcp_sk(sk)->fully_established);
764}
765
766void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
767void mptcp_data_ready(struct sock *sk, struct sock *ssk);
768bool mptcp_finish_join(struct sock *sk);
769bool mptcp_schedule_work(struct sock *sk);
770int mptcp_setsockopt(struct sock *sk, int level, int optname,
771 sockptr_t optval, unsigned int optlen);
772int mptcp_getsockopt(struct sock *sk, int level, int optname,
773 char __user *optval, int __user *option);
774
775u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
776static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
777{
778 if (use_64bit)
779 return cur_seq;
780
781 return __mptcp_expand_seq(old_seq, cur_seq);
782}
783void __mptcp_check_push(struct sock *sk, struct sock *ssk);
784void __mptcp_data_acked(struct sock *sk);
785void __mptcp_error_report(struct sock *sk);
786bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
787static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
788{
789 return READ_ONCE(msk->snd_data_fin_enable) &&
790 READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
791}
792
793static inline void mptcp_write_space(struct sock *sk)
794{
795 if (sk_stream_is_writeable(sk)) {
796 /* pairs with memory barrier in mptcp_poll */
797 smp_mb();
798 if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
799 sk_stream_write_space(sk);
800 }
801}
802
803static inline void __mptcp_sync_sndbuf(struct sock *sk)
804{
805 struct mptcp_subflow_context *subflow;
806 int ssk_sndbuf, new_sndbuf;
807
808 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
809 return;
810
811 new_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[0];
812 mptcp_for_each_subflow(mptcp_sk(sk), subflow) {
813 ssk_sndbuf = READ_ONCE(mptcp_subflow_tcp_sock(subflow)->sk_sndbuf);
814
815 subflow->cached_sndbuf = ssk_sndbuf;
816 new_sndbuf += ssk_sndbuf;
817 }
818
819 /* the msk max wmem limit is <nr_subflows> * tcp wmem[2] */
820 WRITE_ONCE(sk->sk_sndbuf, new_sndbuf);
821 mptcp_write_space(sk);
822}
823
824/* The called held both the msk socket and the subflow socket locks,
825 * possibly under BH
826 */
827static inline void __mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
828{
829 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
830
831 if (READ_ONCE(ssk->sk_sndbuf) != subflow->cached_sndbuf)
832 __mptcp_sync_sndbuf(sk);
833}
834
835/* the caller held only the subflow socket lock, either in process or
836 * BH context. Additionally this can be called under the msk data lock,
837 * so we can't acquire such lock here: let the delegate action acquires
838 * the needed locks in suitable order.
839 */
840static inline void mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
841{
842 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
843
844 if (likely(READ_ONCE(ssk->sk_sndbuf) == subflow->cached_sndbuf))
845 return;
846
847 local_bh_disable();
848 mptcp_subflow_delegate(subflow, MPTCP_DELEGATE_SNDBUF);
849 local_bh_enable();
850}
851
852void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
853
854#define MPTCP_TOKEN_MAX_RETRIES 4
855
856void __init mptcp_token_init(void);
857static inline void mptcp_token_init_request(struct request_sock *req)
858{
859 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
860}
861
862int mptcp_token_new_request(struct request_sock *req);
863void mptcp_token_destroy_request(struct request_sock *req);
864int mptcp_token_new_connect(struct sock *ssk);
865void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
866 struct mptcp_sock *msk);
867bool mptcp_token_exists(u32 token);
868struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
869struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
870 long *s_num);
871void mptcp_token_destroy(struct mptcp_sock *msk);
872
873void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
874
875void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
876__sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
877
878void __init mptcp_pm_init(void);
879void mptcp_pm_data_init(struct mptcp_sock *msk);
880void mptcp_pm_data_reset(struct mptcp_sock *msk);
881int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
882 struct mptcp_addr_info *addr);
883int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
884 bool require_family,
885 struct mptcp_pm_addr_entry *entry);
886bool mptcp_pm_addr_families_match(const struct sock *sk,
887 const struct mptcp_addr_info *loc,
888 const struct mptcp_addr_info *rem);
889void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
890void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
891void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
892void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk);
893bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
894void mptcp_pm_connection_closed(struct mptcp_sock *msk);
895void mptcp_pm_subflow_established(struct mptcp_sock *msk);
896bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
897void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
898 const struct mptcp_subflow_context *subflow);
899void mptcp_pm_add_addr_received(const struct sock *ssk,
900 const struct mptcp_addr_info *addr);
901void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
902 const struct mptcp_addr_info *addr);
903void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
904void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
905void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
906 const struct mptcp_rm_list *rm_list);
907void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
908void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
909int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
910 struct mptcp_addr_info *addr,
911 struct mptcp_addr_info *rem,
912 u8 bkup);
913bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
914 const struct mptcp_addr_info *addr);
915void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
916bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
917struct mptcp_pm_add_entry *
918mptcp_pm_del_add_timer(struct mptcp_sock *msk,
919 const struct mptcp_addr_info *addr, bool check_id);
920struct mptcp_pm_add_entry *
921mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
922 const struct mptcp_addr_info *addr);
923int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
924 unsigned int id,
925 u8 *flags, int *ifindex);
926int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
927 u8 *flags, int *ifindex);
928int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
929 unsigned int id,
930 u8 *flags, int *ifindex);
931int mptcp_pm_set_flags(struct net *net, struct nlattr *token,
932 struct mptcp_pm_addr_entry *loc,
933 struct mptcp_pm_addr_entry *rem, u8 bkup);
934int mptcp_pm_nl_set_flags(struct net *net, struct mptcp_pm_addr_entry *addr, u8 bkup);
935int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
936 struct mptcp_pm_addr_entry *loc,
937 struct mptcp_pm_addr_entry *rem, u8 bkup);
938int mptcp_pm_announce_addr(struct mptcp_sock *msk,
939 const struct mptcp_addr_info *addr,
940 bool echo);
941int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
942int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
943void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list);
944void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
945 struct list_head *rm_list);
946
947void mptcp_free_local_addr_list(struct mptcp_sock *msk);
948
949void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
950 const struct sock *ssk, gfp_t gfp);
951void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
952void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
953void mptcp_event_pm_listener(const struct sock *ssk,
954 enum mptcp_event_type event);
955bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
956
957void __mptcp_fastopen_gen_msk_ackseq(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
958 const struct mptcp_options_received *mp_opt);
959void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow,
960 struct request_sock *req);
961
962static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
963{
964 return READ_ONCE(msk->pm.addr_signal) &
965 (BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
966}
967
968static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
969{
970 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
971}
972
973static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
974{
975 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
976}
977
978static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
979{
980 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
981}
982
983static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
984{
985 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
986}
987
988static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
989{
990 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
991}
992
993static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
994{
995 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
996
997 if (family == AF_INET6)
998 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
999 if (!echo)
1000 len += MPTCPOPT_THMAC_LEN;
1001 /* account for 2 trailing 'nop' options */
1002 if (port)
1003 len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
1004
1005 return len;
1006}
1007
1008static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
1009{
1010 if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
1011 return -EINVAL;
1012
1013 return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
1014}
1015
1016bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
1017 unsigned int opt_size, unsigned int remaining,
1018 struct mptcp_addr_info *addr, bool *echo,
1019 bool *drop_other_suboptions);
1020bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
1021 struct mptcp_rm_list *rm_list);
1022int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
1023int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1024int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1025
1026static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow)
1027{
1028 int local_id = READ_ONCE(subflow->local_id);
1029
1030 if (local_id < 0)
1031 return 0;
1032 return local_id;
1033}
1034
1035void __init mptcp_pm_nl_init(void);
1036void mptcp_pm_nl_work(struct mptcp_sock *msk);
1037void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
1038 const struct mptcp_rm_list *rm_list);
1039unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
1040unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
1041unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
1042unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
1043
1044/* called under PM lock */
1045static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
1046{
1047 if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
1048 WRITE_ONCE(msk->pm.accept_subflow, true);
1049}
1050
1051static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
1052{
1053 spin_lock_bh(&msk->pm.lock);
1054 __mptcp_pm_close_subflow(msk);
1055 spin_unlock_bh(&msk->pm.lock);
1056}
1057
1058void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
1059void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
1060
1061static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
1062{
1063 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
1064}
1065
1066void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
1067
1068static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
1069{
1070 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
1071}
1072
1073static inline bool mptcp_check_fallback(const struct sock *sk)
1074{
1075 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1076 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
1077
1078 return __mptcp_check_fallback(msk);
1079}
1080
1081static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
1082{
1083 if (__mptcp_check_fallback(msk)) {
1084 pr_debug("TCP fallback already done (msk=%p)", msk);
1085 return;
1086 }
1087 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
1088}
1089
1090static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
1091{
1092 struct sock *ssk = READ_ONCE(msk->first);
1093
1094 return ssk && ((1 << inet_sk_state_load(ssk)) &
1095 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1096 TCPF_SYN_RECV | TCPF_LISTEN));
1097}
1098
1099static inline void mptcp_do_fallback(struct sock *ssk)
1100{
1101 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
1102 struct sock *sk = subflow->conn;
1103 struct mptcp_sock *msk;
1104
1105 msk = mptcp_sk(sk);
1106 __mptcp_do_fallback(msk);
1107 if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
1108 gfp_t saved_allocation = ssk->sk_allocation;
1109
1110 /* we are in a atomic (BH) scope, override ssk default for data
1111 * fin allocation
1112 */
1113 ssk->sk_allocation = GFP_ATOMIC;
1114 ssk->sk_shutdown |= SEND_SHUTDOWN;
1115 tcp_shutdown(ssk, SEND_SHUTDOWN);
1116 ssk->sk_allocation = saved_allocation;
1117 }
1118}
1119
1120#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
1121
1122static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
1123{
1124 struct mptcp_ext *mpext;
1125
1126 mpext = skb ? mptcp_get_ext(skb) : NULL;
1127 if (mpext && mpext->infinite_map)
1128 return true;
1129
1130 return false;
1131}
1132
1133static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
1134{
1135 return (subflow->request_mptcp || subflow->request_join);
1136}
1137
1138static inline bool subflow_simultaneous_connect(struct sock *sk)
1139{
1140 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1141
1142 return (1 << sk->sk_state) &
1143 (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSING) &&
1144 is_active_ssk(subflow) &&
1145 !subflow->conn_finished;
1146}
1147
1148#ifdef CONFIG_SYN_COOKIES
1149void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1150 struct sk_buff *skb);
1151bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1152 struct sk_buff *skb);
1153void __init mptcp_join_cookie_init(void);
1154#else
1155static inline void
1156subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1157 struct sk_buff *skb) {}
1158static inline bool
1159mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1160 struct sk_buff *skb)
1161{
1162 return false;
1163}
1164
1165static inline void mptcp_join_cookie_init(void) {}
1166#endif
1167
1168#endif /* __MPTCP_PROTOCOL_H */
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
15#define MPTCP_SUPPORTED_VERSION 1
16
17/* MPTCP option bits */
18#define OPTION_MPTCP_MPC_SYN BIT(0)
19#define OPTION_MPTCP_MPC_SYNACK BIT(1)
20#define OPTION_MPTCP_MPC_ACK BIT(2)
21#define OPTION_MPTCP_MPJ_SYN BIT(3)
22#define OPTION_MPTCP_MPJ_SYNACK BIT(4)
23#define OPTION_MPTCP_MPJ_ACK BIT(5)
24#define OPTION_MPTCP_ADD_ADDR BIT(6)
25#define OPTION_MPTCP_RM_ADDR BIT(7)
26#define OPTION_MPTCP_FASTCLOSE BIT(8)
27#define OPTION_MPTCP_PRIO BIT(9)
28#define OPTION_MPTCP_RST BIT(10)
29
30/* MPTCP option subtypes */
31#define MPTCPOPT_MP_CAPABLE 0
32#define MPTCPOPT_MP_JOIN 1
33#define MPTCPOPT_DSS 2
34#define MPTCPOPT_ADD_ADDR 3
35#define MPTCPOPT_RM_ADDR 4
36#define MPTCPOPT_MP_PRIO 5
37#define MPTCPOPT_MP_FAIL 6
38#define MPTCPOPT_MP_FASTCLOSE 7
39#define MPTCPOPT_RST 8
40
41/* MPTCP suboption lengths */
42#define TCPOLEN_MPTCP_MPC_SYN 4
43#define TCPOLEN_MPTCP_MPC_SYNACK 12
44#define TCPOLEN_MPTCP_MPC_ACK 20
45#define TCPOLEN_MPTCP_MPC_ACK_DATA 22
46#define TCPOLEN_MPTCP_MPJ_SYN 12
47#define TCPOLEN_MPTCP_MPJ_SYNACK 16
48#define TCPOLEN_MPTCP_MPJ_ACK 24
49#define TCPOLEN_MPTCP_DSS_BASE 4
50#define TCPOLEN_MPTCP_DSS_ACK32 4
51#define TCPOLEN_MPTCP_DSS_ACK64 8
52#define TCPOLEN_MPTCP_DSS_MAP32 10
53#define TCPOLEN_MPTCP_DSS_MAP64 14
54#define TCPOLEN_MPTCP_DSS_CHECKSUM 2
55#define TCPOLEN_MPTCP_ADD_ADDR 16
56#define TCPOLEN_MPTCP_ADD_ADDR_PORT 18
57#define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
58#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10
59#define TCPOLEN_MPTCP_ADD_ADDR6 28
60#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30
61#define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
62#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22
63#define TCPOLEN_MPTCP_PORT_LEN 2
64#define TCPOLEN_MPTCP_PORT_ALIGN 2
65#define TCPOLEN_MPTCP_RM_ADDR_BASE 3
66#define TCPOLEN_MPTCP_PRIO 3
67#define TCPOLEN_MPTCP_PRIO_ALIGN 4
68#define TCPOLEN_MPTCP_FASTCLOSE 12
69#define TCPOLEN_MPTCP_RST 4
70
71#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
72
73/* MPTCP MP_JOIN flags */
74#define MPTCPOPT_BACKUP BIT(0)
75#define MPTCPOPT_HMAC_LEN 20
76#define MPTCPOPT_THMAC_LEN 8
77
78/* MPTCP MP_CAPABLE flags */
79#define MPTCP_VERSION_MASK (0x0F)
80#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
81#define MPTCP_CAP_EXTENSIBILITY BIT(6)
82#define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
83#define MPTCP_CAP_HMAC_SHA256 BIT(0)
84#define MPTCP_CAP_FLAG_MASK (0x1F)
85
86/* MPTCP DSS flags */
87#define MPTCP_DSS_DATA_FIN BIT(4)
88#define MPTCP_DSS_DSN64 BIT(3)
89#define MPTCP_DSS_HAS_MAP BIT(2)
90#define MPTCP_DSS_ACK64 BIT(1)
91#define MPTCP_DSS_HAS_ACK BIT(0)
92#define MPTCP_DSS_FLAG_MASK (0x1F)
93
94/* MPTCP ADD_ADDR flags */
95#define MPTCP_ADDR_ECHO BIT(0)
96
97/* MPTCP MP_PRIO flags */
98#define MPTCP_PRIO_BKUP BIT(0)
99
100/* MPTCP TCPRST flags */
101#define MPTCP_RST_TRANSIENT BIT(0)
102
103/* MPTCP socket flags */
104#define MPTCP_DATA_READY 0
105#define MPTCP_NOSPACE 1
106#define MPTCP_WORK_RTX 2
107#define MPTCP_WORK_EOF 3
108#define MPTCP_FALLBACK_DONE 4
109#define MPTCP_WORK_CLOSE_SUBFLOW 5
110#define MPTCP_PUSH_PENDING 6
111#define MPTCP_CLEAN_UNA 7
112#define MPTCP_ERROR_REPORT 8
113#define MPTCP_RETRANSMIT 9
114#define MPTCP_WORK_SYNC_SETSOCKOPT 10
115#define MPTCP_CONNECTED 11
116
117static inline bool before64(__u64 seq1, __u64 seq2)
118{
119 return (__s64)(seq1 - seq2) < 0;
120}
121
122#define after64(seq2, seq1) before64(seq1, seq2)
123
124struct mptcp_options_received {
125 u64 sndr_key;
126 u64 rcvr_key;
127 u64 data_ack;
128 u64 data_seq;
129 u32 subflow_seq;
130 u16 data_len;
131 __sum16 csum;
132 u16 mp_capable : 1,
133 mp_join : 1,
134 fastclose : 1,
135 reset : 1,
136 dss : 1,
137 add_addr : 1,
138 rm_addr : 1,
139 mp_prio : 1,
140 echo : 1,
141 csum_reqd : 1,
142 backup : 1,
143 deny_join_id0 : 1;
144 u32 token;
145 u32 nonce;
146 u64 thmac;
147 u8 hmac[MPTCPOPT_HMAC_LEN];
148 u8 join_id;
149 u8 use_map:1,
150 dsn64:1,
151 data_fin:1,
152 use_ack:1,
153 ack64:1,
154 mpc_map:1,
155 __unused:2;
156 struct mptcp_addr_info addr;
157 struct mptcp_rm_list rm_list;
158 u64 ahmac;
159 u8 reset_reason:4;
160 u8 reset_transient:1;
161};
162
163static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
164{
165 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
166 ((nib & 0xF) << 8) | field);
167}
168
169enum mptcp_pm_status {
170 MPTCP_PM_ADD_ADDR_RECEIVED,
171 MPTCP_PM_ADD_ADDR_SEND_ACK,
172 MPTCP_PM_RM_ADDR_RECEIVED,
173 MPTCP_PM_ESTABLISHED,
174 MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */
175 MPTCP_PM_SUBFLOW_ESTABLISHED,
176};
177
178enum mptcp_addr_signal_status {
179 MPTCP_ADD_ADDR_SIGNAL,
180 MPTCP_ADD_ADDR_ECHO,
181 MPTCP_ADD_ADDR_IPV6,
182 MPTCP_ADD_ADDR_PORT,
183 MPTCP_RM_ADDR_SIGNAL,
184};
185
186struct mptcp_pm_data {
187 struct mptcp_addr_info local;
188 struct mptcp_addr_info remote;
189 struct list_head anno_list;
190
191 spinlock_t lock; /*protects the whole PM data */
192
193 u8 addr_signal;
194 bool server_side;
195 bool work_pending;
196 bool accept_addr;
197 bool accept_subflow;
198 bool remote_deny_join_id0;
199 u8 add_addr_signaled;
200 u8 add_addr_accepted;
201 u8 local_addr_used;
202 u8 subflows;
203 u8 status;
204 struct mptcp_rm_list rm_list_tx;
205 struct mptcp_rm_list rm_list_rx;
206};
207
208struct mptcp_data_frag {
209 struct list_head list;
210 u64 data_seq;
211 u16 data_len;
212 u16 offset;
213 u16 overhead;
214 u16 already_sent;
215 struct page *page;
216};
217
218/* MPTCP connection sock */
219struct mptcp_sock {
220 /* inet_connection_sock must be the first member */
221 struct inet_connection_sock sk;
222 u64 local_key;
223 u64 remote_key;
224 u64 write_seq;
225 u64 snd_nxt;
226 u64 ack_seq;
227 u64 rcv_wnd_sent;
228 u64 rcv_data_fin_seq;
229 int wmem_reserved;
230 struct sock *last_snd;
231 int snd_burst;
232 int old_wspace;
233 u64 snd_una;
234 u64 wnd_end;
235 unsigned long timer_ival;
236 u32 token;
237 int rmem_released;
238 unsigned long flags;
239 bool can_ack;
240 bool fully_established;
241 bool rcv_data_fin;
242 bool snd_data_fin_enable;
243 bool rcv_fastclose;
244 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
245 bool csum_enabled;
246 spinlock_t join_list_lock;
247 struct work_struct work;
248 struct sk_buff *ooo_last_skb;
249 struct rb_root out_of_order_queue;
250 struct sk_buff_head receive_queue;
251 int tx_pending_data;
252 struct list_head conn_list;
253 struct list_head rtx_queue;
254 struct mptcp_data_frag *first_pending;
255 struct list_head join_list;
256 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
257 struct sock *first;
258 struct mptcp_pm_data pm;
259 struct {
260 u32 space; /* bytes copied in last measurement window */
261 u32 copied; /* bytes copied in this measurement window */
262 u64 time; /* start time of measurement window */
263 u64 rtt_us; /* last maximum rtt of subflows */
264 } rcvq_space;
265
266 u32 setsockopt_seq;
267 char ca_name[TCP_CA_NAME_MAX];
268};
269
270#define mptcp_lock_sock(___sk, cb) do { \
271 struct sock *__sk = (___sk); /* silence macro reuse warning */ \
272 might_sleep(); \
273 spin_lock_bh(&__sk->sk_lock.slock); \
274 if (__sk->sk_lock.owned) \
275 __lock_sock(__sk); \
276 cb; \
277 __sk->sk_lock.owned = 1; \
278 spin_unlock(&__sk->sk_lock.slock); \
279 mutex_acquire(&__sk->sk_lock.dep_map, 0, 0, _RET_IP_); \
280 local_bh_enable(); \
281} while (0)
282
283#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
284#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
285
286#define mptcp_for_each_subflow(__msk, __subflow) \
287 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
288
289static inline void msk_owned_by_me(const struct mptcp_sock *msk)
290{
291 sock_owned_by_me((const struct sock *)msk);
292}
293
294static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
295{
296 return (struct mptcp_sock *)sk;
297}
298
299/* the msk socket don't use the backlog, also account for the bulk
300 * free memory
301 */
302static inline int __mptcp_rmem(const struct sock *sk)
303{
304 return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
305}
306
307static inline int __mptcp_space(const struct sock *sk)
308{
309 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
310}
311
312static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
313{
314 const struct mptcp_sock *msk = mptcp_sk(sk);
315
316 return READ_ONCE(msk->first_pending);
317}
318
319static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
320{
321 struct mptcp_sock *msk = mptcp_sk(sk);
322 struct mptcp_data_frag *cur;
323
324 cur = msk->first_pending;
325 return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
326 list_next_entry(cur, list);
327}
328
329static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
330{
331 struct mptcp_sock *msk = mptcp_sk(sk);
332
333 if (!msk->first_pending)
334 return NULL;
335
336 if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
337 return NULL;
338
339 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
340}
341
342static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
343{
344 struct mptcp_sock *msk = mptcp_sk(sk);
345
346 if (msk->snd_una == READ_ONCE(msk->snd_nxt))
347 return NULL;
348
349 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
350}
351
352struct csum_pseudo_header {
353 __be64 data_seq;
354 __be32 subflow_seq;
355 __be16 data_len;
356 __sum16 csum;
357};
358
359struct mptcp_subflow_request_sock {
360 struct tcp_request_sock sk;
361 u16 mp_capable : 1,
362 mp_join : 1,
363 backup : 1,
364 csum_reqd : 1,
365 allow_join_id0 : 1;
366 u8 local_id;
367 u8 remote_id;
368 u64 local_key;
369 u64 idsn;
370 u32 token;
371 u32 ssn_offset;
372 u64 thmac;
373 u32 local_nonce;
374 u32 remote_nonce;
375 struct mptcp_sock *msk;
376 struct hlist_nulls_node token_node;
377};
378
379static inline struct mptcp_subflow_request_sock *
380mptcp_subflow_rsk(const struct request_sock *rsk)
381{
382 return (struct mptcp_subflow_request_sock *)rsk;
383}
384
385enum mptcp_data_avail {
386 MPTCP_SUBFLOW_NODATA,
387 MPTCP_SUBFLOW_DATA_AVAIL,
388};
389
390struct mptcp_delegated_action {
391 struct napi_struct napi;
392 struct list_head head;
393};
394
395DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
396
397#define MPTCP_DELEGATE_SEND 0
398
399/* MPTCP subflow context */
400struct mptcp_subflow_context {
401 struct list_head node;/* conn_list of subflows */
402 u64 local_key;
403 u64 remote_key;
404 u64 idsn;
405 u64 map_seq;
406 u32 snd_isn;
407 u32 token;
408 u32 rel_write_seq;
409 u32 map_subflow_seq;
410 u32 ssn_offset;
411 u32 map_data_len;
412 __wsum map_data_csum;
413 u32 map_csum_len;
414 u32 request_mptcp : 1, /* send MP_CAPABLE */
415 request_join : 1, /* send MP_JOIN */
416 request_bkup : 1,
417 mp_capable : 1, /* remote is MPTCP capable */
418 mp_join : 1, /* remote is JOINing */
419 fully_established : 1, /* path validated */
420 pm_notified : 1, /* PM hook called for established status */
421 conn_finished : 1,
422 map_valid : 1,
423 map_csum_reqd : 1,
424 map_data_fin : 1,
425 mpc_map : 1,
426 backup : 1,
427 send_mp_prio : 1,
428 rx_eof : 1,
429 can_ack : 1, /* only after processing the remote a key */
430 disposable : 1; /* ctx can be free at ulp release time */
431 enum mptcp_data_avail data_avail;
432 u32 remote_nonce;
433 u64 thmac;
434 u32 local_nonce;
435 u32 remote_token;
436 u8 hmac[MPTCPOPT_HMAC_LEN];
437 u8 local_id;
438 u8 remote_id;
439 u8 reset_seen:1;
440 u8 reset_transient:1;
441 u8 reset_reason:4;
442
443 long delegated_status;
444 struct list_head delegated_node; /* link into delegated_action, protected by local BH */
445
446 u32 setsockopt_seq;
447
448 struct sock *tcp_sock; /* tcp sk backpointer */
449 struct sock *conn; /* parent mptcp_sock */
450 const struct inet_connection_sock_af_ops *icsk_af_ops;
451 void (*tcp_data_ready)(struct sock *sk);
452 void (*tcp_state_change)(struct sock *sk);
453 void (*tcp_write_space)(struct sock *sk);
454 void (*tcp_error_report)(struct sock *sk);
455
456 struct rcu_head rcu;
457};
458
459static inline struct mptcp_subflow_context *
460mptcp_subflow_ctx(const struct sock *sk)
461{
462 struct inet_connection_sock *icsk = inet_csk(sk);
463
464 /* Use RCU on icsk_ulp_data only for sock diag code */
465 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
466}
467
468static inline struct sock *
469mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
470{
471 return subflow->tcp_sock;
472}
473
474static inline u64
475mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
476{
477 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
478 subflow->ssn_offset -
479 subflow->map_subflow_seq;
480}
481
482static inline u64
483mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
484{
485 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
486}
487
488static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk,
489 struct mptcp_subflow_context *subflow)
490{
491 sock_hold(mptcp_subflow_tcp_sock(subflow));
492 spin_lock_bh(&msk->join_list_lock);
493 list_add_tail(&subflow->node, &msk->join_list);
494 spin_unlock_bh(&msk->join_list_lock);
495}
496
497void mptcp_subflow_process_delegated(struct sock *ssk);
498
499static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow)
500{
501 struct mptcp_delegated_action *delegated;
502 bool schedule;
503
504 /* The implied barrier pairs with mptcp_subflow_delegated_done(), and
505 * ensures the below list check sees list updates done prior to status
506 * bit changes
507 */
508 if (!test_and_set_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) {
509 /* still on delegated list from previous scheduling */
510 if (!list_empty(&subflow->delegated_node))
511 return;
512
513 /* the caller held the subflow bh socket lock */
514 lockdep_assert_in_softirq();
515
516 delegated = this_cpu_ptr(&mptcp_delegated_actions);
517 schedule = list_empty(&delegated->head);
518 list_add_tail(&subflow->delegated_node, &delegated->head);
519 sock_hold(mptcp_subflow_tcp_sock(subflow));
520 if (schedule)
521 napi_schedule(&delegated->napi);
522 }
523}
524
525static inline struct mptcp_subflow_context *
526mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
527{
528 struct mptcp_subflow_context *ret;
529
530 if (list_empty(&delegated->head))
531 return NULL;
532
533 ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
534 list_del_init(&ret->delegated_node);
535 return ret;
536}
537
538static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
539{
540 return test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
541}
542
543static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow)
544{
545 /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
546 * touching the status bit
547 */
548 smp_wmb();
549 clear_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status);
550}
551
552int mptcp_is_enabled(struct net *net);
553unsigned int mptcp_get_add_addr_timeout(struct net *net);
554int mptcp_is_checksum_enabled(struct net *net);
555int mptcp_allow_join_id0(struct net *net);
556void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
557 struct mptcp_options_received *mp_opt);
558bool mptcp_subflow_data_available(struct sock *sk);
559void __init mptcp_subflow_init(void);
560void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
561void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
562 struct mptcp_subflow_context *subflow);
563void mptcp_subflow_send_ack(struct sock *ssk);
564void mptcp_subflow_reset(struct sock *ssk);
565void mptcp_sock_graft(struct sock *sk, struct socket *parent);
566struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
567
568/* called with sk socket lock held */
569int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
570 const struct mptcp_addr_info *remote,
571 u8 flags, int ifindex);
572int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
573void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
574 struct sockaddr_storage *addr,
575 unsigned short family);
576
577static inline bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
578{
579 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
580
581 /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
582 if (subflow->request_join && !subflow->fully_established)
583 return false;
584
585 /* only send if our side has not closed yet */
586 return ((1 << ssk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
587}
588
589static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
590 struct mptcp_subflow_context *ctx)
591{
592 sk->sk_data_ready = ctx->tcp_data_ready;
593 sk->sk_state_change = ctx->tcp_state_change;
594 sk->sk_write_space = ctx->tcp_write_space;
595 sk->sk_error_report = ctx->tcp_error_report;
596
597 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
598}
599
600void __init mptcp_proto_init(void);
601#if IS_ENABLED(CONFIG_MPTCP_IPV6)
602int __init mptcp_proto_v6_init(void);
603#endif
604
605struct sock *mptcp_sk_clone(const struct sock *sk,
606 const struct mptcp_options_received *mp_opt,
607 struct request_sock *req);
608void mptcp_get_options(const struct sock *sk,
609 const struct sk_buff *skb,
610 struct mptcp_options_received *mp_opt);
611
612void mptcp_finish_connect(struct sock *sk);
613void __mptcp_set_connected(struct sock *sk);
614static inline bool mptcp_is_fully_established(struct sock *sk)
615{
616 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
617 READ_ONCE(mptcp_sk(sk)->fully_established);
618}
619void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
620void mptcp_data_ready(struct sock *sk, struct sock *ssk);
621bool mptcp_finish_join(struct sock *sk);
622bool mptcp_schedule_work(struct sock *sk);
623int mptcp_setsockopt(struct sock *sk, int level, int optname,
624 sockptr_t optval, unsigned int optlen);
625int mptcp_getsockopt(struct sock *sk, int level, int optname,
626 char __user *optval, int __user *option);
627
628u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
629static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
630{
631 if (use_64bit)
632 return cur_seq;
633
634 return __mptcp_expand_seq(old_seq, cur_seq);
635}
636void __mptcp_check_push(struct sock *sk, struct sock *ssk);
637void __mptcp_data_acked(struct sock *sk);
638void __mptcp_error_report(struct sock *sk);
639void mptcp_subflow_eof(struct sock *sk);
640bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
641void __mptcp_flush_join_list(struct mptcp_sock *msk);
642static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
643{
644 return READ_ONCE(msk->snd_data_fin_enable) &&
645 READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
646}
647
648static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
649{
650 if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
651 return false;
652
653 WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
654 return true;
655}
656
657static inline void mptcp_write_space(struct sock *sk)
658{
659 if (sk_stream_is_writeable(sk)) {
660 /* pairs with memory barrier in mptcp_poll */
661 smp_mb();
662 if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
663 sk_stream_write_space(sk);
664 }
665}
666
667void mptcp_destroy_common(struct mptcp_sock *msk);
668
669#define MPTCP_TOKEN_MAX_RETRIES 4
670
671void __init mptcp_token_init(void);
672static inline void mptcp_token_init_request(struct request_sock *req)
673{
674 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
675}
676
677int mptcp_token_new_request(struct request_sock *req);
678void mptcp_token_destroy_request(struct request_sock *req);
679int mptcp_token_new_connect(struct sock *sk);
680void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
681 struct mptcp_sock *msk);
682bool mptcp_token_exists(u32 token);
683struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
684struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
685 long *s_num);
686void mptcp_token_destroy(struct mptcp_sock *msk);
687
688void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
689
690void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
691
692void __init mptcp_pm_init(void);
693void mptcp_pm_data_init(struct mptcp_sock *msk);
694void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
695void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
696bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
697void mptcp_pm_connection_closed(struct mptcp_sock *msk);
698void mptcp_pm_subflow_established(struct mptcp_sock *msk);
699void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
700void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
701 const struct mptcp_addr_info *addr);
702void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
703 struct mptcp_addr_info *addr);
704void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
705void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
706void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
707 const struct mptcp_rm_list *rm_list);
708void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
709int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
710 struct mptcp_addr_info *addr,
711 u8 bkup);
712void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
713bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
714struct mptcp_pm_add_entry *
715mptcp_pm_del_add_timer(struct mptcp_sock *msk,
716 struct mptcp_addr_info *addr, bool check_id);
717struct mptcp_pm_add_entry *
718mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk,
719 struct mptcp_addr_info *addr);
720
721int mptcp_pm_announce_addr(struct mptcp_sock *msk,
722 const struct mptcp_addr_info *addr,
723 bool echo);
724int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
725int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
726
727void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
728 const struct sock *ssk, gfp_t gfp);
729void mptcp_event_addr_announced(const struct mptcp_sock *msk, const struct mptcp_addr_info *info);
730void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
731
732static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
733{
734 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
735}
736
737static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
738{
739 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
740}
741
742static inline bool mptcp_pm_should_add_signal_ipv6(struct mptcp_sock *msk)
743{
744 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_IPV6);
745}
746
747static inline bool mptcp_pm_should_add_signal_port(struct mptcp_sock *msk)
748{
749 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_PORT);
750}
751
752static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
753{
754 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
755}
756
757static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
758{
759 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
760
761 if (family == AF_INET6)
762 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
763 if (!echo)
764 len += MPTCPOPT_THMAC_LEN;
765 /* account for 2 trailing 'nop' options */
766 if (port)
767 len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
768
769 return len;
770}
771
772static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
773{
774 if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
775 return -EINVAL;
776
777 return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
778}
779
780bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
781 struct mptcp_addr_info *saddr, bool *echo, bool *port);
782bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
783 struct mptcp_rm_list *rm_list);
784int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
785
786void __init mptcp_pm_nl_init(void);
787void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
788void mptcp_pm_nl_work(struct mptcp_sock *msk);
789void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
790 const struct mptcp_rm_list *rm_list);
791int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
792unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk);
793unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk);
794unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk);
795unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk);
796
797void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
798void mptcp_sockopt_sync_all(struct mptcp_sock *msk);
799
800static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
801{
802 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
803}
804
805void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
806
807static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
808{
809 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
810}
811
812static inline bool mptcp_check_fallback(const struct sock *sk)
813{
814 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
815 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
816
817 return __mptcp_check_fallback(msk);
818}
819
820static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
821{
822 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
823 pr_debug("TCP fallback already done (msk=%p)", msk);
824 return;
825 }
826 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
827}
828
829static inline void mptcp_do_fallback(struct sock *sk)
830{
831 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
832 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
833
834 __mptcp_do_fallback(msk);
835}
836
837#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
838
839static inline bool subflow_simultaneous_connect(struct sock *sk)
840{
841 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
842 struct sock *parent = subflow->conn;
843
844 return sk->sk_state == TCP_ESTABLISHED &&
845 !mptcp_sk(parent)->pm.server_side &&
846 !subflow->conn_finished;
847}
848
849#ifdef CONFIG_SYN_COOKIES
850void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
851 struct sk_buff *skb);
852bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
853 struct sk_buff *skb);
854void __init mptcp_join_cookie_init(void);
855#else
856static inline void
857subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
858 struct sk_buff *skb) {}
859static inline bool
860mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
861 struct sk_buff *skb)
862{
863 return false;
864}
865
866static inline void mptcp_join_cookie_init(void) {}
867#endif
868
869#endif /* __MPTCP_PROTOCOL_H */