1 /* SPDX-License-Identifier: GPL-2.0 */
4 * Copyright (c) 2017 - 2019, Intel Corporation.
7 #ifndef __MPTCP_PROTOCOL_H
8 #define __MPTCP_PROTOCOL_H
10 #include <linux/random.h>
12 #include <net/inet_connection_sock.h>
14 #define MPTCP_SUPPORTED_VERSION 1
16 /* MPTCP option bits */
17 #define OPTION_MPTCP_MPC_SYN BIT(0)
18 #define OPTION_MPTCP_MPC_SYNACK BIT(1)
19 #define OPTION_MPTCP_MPC_ACK BIT(2)
20 #define OPTION_MPTCP_MPJ_SYN BIT(3)
21 #define OPTION_MPTCP_MPJ_SYNACK BIT(4)
22 #define OPTION_MPTCP_MPJ_ACK BIT(5)
23 #define OPTION_MPTCP_ADD_ADDR BIT(6)
24 #define OPTION_MPTCP_ADD_ADDR6 BIT(7)
25 #define OPTION_MPTCP_RM_ADDR BIT(8)
26 #define OPTION_MPTCP_FASTCLOSE BIT(9)
28 /* MPTCP option subtypes */
29 #define MPTCPOPT_MP_CAPABLE 0
30 #define MPTCPOPT_MP_JOIN 1
31 #define MPTCPOPT_DSS 2
32 #define MPTCPOPT_ADD_ADDR 3
33 #define MPTCPOPT_RM_ADDR 4
34 #define MPTCPOPT_MP_PRIO 5
35 #define MPTCPOPT_MP_FAIL 6
36 #define MPTCPOPT_MP_FASTCLOSE 7
38 /* MPTCP suboption lengths */
39 #define TCPOLEN_MPTCP_MPC_SYN 4
40 #define TCPOLEN_MPTCP_MPC_SYNACK 12
41 #define TCPOLEN_MPTCP_MPC_ACK 20
42 #define TCPOLEN_MPTCP_MPC_ACK_DATA 22
43 #define TCPOLEN_MPTCP_MPJ_SYN 12
44 #define TCPOLEN_MPTCP_MPJ_SYNACK 16
45 #define TCPOLEN_MPTCP_MPJ_ACK 24
46 #define TCPOLEN_MPTCP_DSS_BASE 4
47 #define TCPOLEN_MPTCP_DSS_ACK32 4
48 #define TCPOLEN_MPTCP_DSS_ACK64 8
49 #define TCPOLEN_MPTCP_DSS_MAP32 10
50 #define TCPOLEN_MPTCP_DSS_MAP64 14
51 #define TCPOLEN_MPTCP_DSS_CHECKSUM 2
52 #define TCPOLEN_MPTCP_ADD_ADDR 16
53 #define TCPOLEN_MPTCP_ADD_ADDR_PORT 20
54 #define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
55 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 12
56 #define TCPOLEN_MPTCP_ADD_ADDR6 28
57 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT 32
58 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
59 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 24
60 #define TCPOLEN_MPTCP_PORT_LEN 4
61 #define TCPOLEN_MPTCP_RM_ADDR_BASE 4
62 #define TCPOLEN_MPTCP_FASTCLOSE 12
64 /* MPTCP MP_JOIN flags */
65 #define MPTCPOPT_BACKUP BIT(0)
66 #define MPTCPOPT_HMAC_LEN 20
67 #define MPTCPOPT_THMAC_LEN 8
69 /* MPTCP MP_CAPABLE flags */
70 #define MPTCP_VERSION_MASK (0x0F)
71 #define MPTCP_CAP_CHECKSUM_REQD BIT(7)
72 #define MPTCP_CAP_EXTENSIBILITY BIT(6)
73 #define MPTCP_CAP_HMAC_SHA256 BIT(0)
74 #define MPTCP_CAP_FLAG_MASK (0x3F)
77 #define MPTCP_DSS_DATA_FIN BIT(4)
78 #define MPTCP_DSS_DSN64 BIT(3)
79 #define MPTCP_DSS_HAS_MAP BIT(2)
80 #define MPTCP_DSS_ACK64 BIT(1)
81 #define MPTCP_DSS_HAS_ACK BIT(0)
82 #define MPTCP_DSS_FLAG_MASK (0x1F)
84 /* MPTCP ADD_ADDR flags */
85 #define MPTCP_ADDR_ECHO BIT(0)
86 #define MPTCP_ADDR_IPVERSION_4 4
87 #define MPTCP_ADDR_IPVERSION_6 6
89 /* MPTCP socket flags */
90 #define MPTCP_DATA_READY 0
91 #define MPTCP_NOSPACE 1
92 #define MPTCP_WORK_RTX 2
93 #define MPTCP_WORK_EOF 3
94 #define MPTCP_FALLBACK_DONE 4
95 #define MPTCP_WORK_CLOSE_SUBFLOW 5
96 #define MPTCP_PUSH_PENDING 6
97 #define MPTCP_CLEAN_UNA 7
98 #define MPTCP_ERROR_REPORT 8
100 static inline bool before64(__u64 seq1, __u64 seq2)
102 return (__s64)(seq1 - seq2) < 0;
105 #define after64(seq2, seq1) before64(seq1, seq2)
107 struct mptcp_options_received {
126 u8 hmac[MPTCPOPT_HMAC_LEN];
139 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
140 struct in6_addr addr6;
147 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
149 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
150 ((nib & 0xF) << 8) | field);
153 struct mptcp_addr_info {
161 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
162 struct in6_addr addr6;
167 enum mptcp_pm_status {
168 MPTCP_PM_ADD_ADDR_RECEIVED,
169 MPTCP_PM_ADD_ADDR_SEND_ACK,
170 MPTCP_PM_RM_ADDR_RECEIVED,
171 MPTCP_PM_ESTABLISHED,
172 MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */
173 MPTCP_PM_SUBFLOW_ESTABLISHED,
176 enum mptcp_addr_signal_status {
177 MPTCP_ADD_ADDR_SIGNAL,
181 MPTCP_RM_ADDR_SIGNAL,
184 struct mptcp_pm_data {
185 struct mptcp_addr_info local;
186 struct mptcp_addr_info remote;
187 struct list_head anno_list;
189 spinlock_t lock; /*protects the whole PM data */
196 u8 add_addr_signaled;
197 u8 add_addr_accepted;
200 u8 add_addr_signal_max;
201 u8 add_addr_accept_max;
208 struct mptcp_data_frag {
209 struct list_head list;
218 /* MPTCP connection sock */
220 /* inet_connection_sock must be the first member */
221 struct inet_connection_sock sk;
228 u64 rcv_data_fin_seq;
230 struct sock *last_snd;
235 unsigned long timer_ival;
241 bool fully_established;
243 bool snd_data_fin_enable;
245 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
246 spinlock_t join_list_lock;
247 struct sock *ack_hint;
248 struct work_struct work;
249 struct sk_buff *ooo_last_skb;
250 struct rb_root out_of_order_queue;
251 struct sk_buff_head receive_queue;
252 struct sk_buff_head skb_tx_cache; /* this is wmem accounted */
255 struct list_head conn_list;
256 struct list_head rtx_queue;
257 struct mptcp_data_frag *first_pending;
258 struct list_head join_list;
259 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
261 struct mptcp_pm_data pm;
263 u32 space; /* bytes copied in last measurement window */
264 u32 copied; /* bytes copied in this measurement window */
265 u64 time; /* start time of measurement window */
266 u64 rtt_us; /* last maximum rtt of subflows */
270 #define mptcp_lock_sock(___sk, cb) do { \
271 struct sock *__sk = (___sk); /* silence macro reuse warning */ \
273 spin_lock_bh(&__sk->sk_lock.slock); \
274 if (__sk->sk_lock.owned) \
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_); \
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)
286 #define mptcp_for_each_subflow(__msk, __subflow) \
287 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
289 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
291 return (struct mptcp_sock *)sk;
294 static inline int __mptcp_space(const struct sock *sk)
296 return tcp_space(sk) + READ_ONCE(mptcp_sk(sk)->rmem_pending);
299 static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
301 const struct mptcp_sock *msk = mptcp_sk(sk);
303 return READ_ONCE(msk->first_pending);
306 static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
308 struct mptcp_sock *msk = mptcp_sk(sk);
309 struct mptcp_data_frag *cur;
311 cur = msk->first_pending;
312 return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
313 list_next_entry(cur, list);
316 static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
318 struct mptcp_sock *msk = mptcp_sk(sk);
320 if (!msk->first_pending)
323 if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
326 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
329 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
331 struct mptcp_sock *msk = mptcp_sk(sk);
333 if (!before64(msk->snd_nxt, READ_ONCE(msk->snd_una)))
336 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
339 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
341 struct mptcp_sock *msk = mptcp_sk(sk);
343 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
346 struct mptcp_subflow_request_sock {
347 struct tcp_request_sock sk;
360 struct mptcp_sock *msk;
361 struct hlist_nulls_node token_node;
364 static inline struct mptcp_subflow_request_sock *
365 mptcp_subflow_rsk(const struct request_sock *rsk)
367 return (struct mptcp_subflow_request_sock *)rsk;
370 enum mptcp_data_avail {
371 MPTCP_SUBFLOW_NODATA,
372 MPTCP_SUBFLOW_DATA_AVAIL,
373 MPTCP_SUBFLOW_OOO_DATA
376 /* MPTCP subflow context */
377 struct mptcp_subflow_context {
378 struct list_head node;/* conn_list of subflows */
389 u32 request_mptcp : 1, /* send MP_CAPABLE */
390 request_join : 1, /* send MP_JOIN */
392 mp_capable : 1, /* remote is MPTCP capable */
393 mp_join : 1, /* remote is JOINing */
394 fully_established : 1, /* path validated */
395 pm_notified : 1, /* PM hook called for established status */
401 can_ack : 1, /* only after processing the remote a key */
402 disposable : 1; /* ctx can be free at ulp release time */
403 enum mptcp_data_avail data_avail;
408 u8 hmac[MPTCPOPT_HMAC_LEN];
412 struct sock *tcp_sock; /* tcp sk backpointer */
413 struct sock *conn; /* parent mptcp_sock */
414 const struct inet_connection_sock_af_ops *icsk_af_ops;
415 void (*tcp_data_ready)(struct sock *sk);
416 void (*tcp_state_change)(struct sock *sk);
417 void (*tcp_write_space)(struct sock *sk);
418 void (*tcp_error_report)(struct sock *sk);
423 static inline struct mptcp_subflow_context *
424 mptcp_subflow_ctx(const struct sock *sk)
426 struct inet_connection_sock *icsk = inet_csk(sk);
428 /* Use RCU on icsk_ulp_data only for sock diag code */
429 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
432 static inline struct sock *
433 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
435 return subflow->tcp_sock;
439 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
441 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
442 subflow->ssn_offset -
443 subflow->map_subflow_seq;
447 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
449 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
452 static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk,
453 struct mptcp_subflow_context *subflow)
455 sock_hold(mptcp_subflow_tcp_sock(subflow));
456 spin_lock_bh(&msk->join_list_lock);
457 list_add_tail(&subflow->node, &msk->join_list);
458 spin_unlock_bh(&msk->join_list_lock);
461 int mptcp_is_enabled(struct net *net);
462 unsigned int mptcp_get_add_addr_timeout(struct net *net);
463 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
464 struct mptcp_options_received *mp_opt);
465 bool mptcp_subflow_data_available(struct sock *sk);
466 void __init mptcp_subflow_init(void);
467 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
468 void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
469 struct mptcp_subflow_context *subflow);
470 void mptcp_subflow_reset(struct sock *ssk);
472 /* called with sk socket lock held */
473 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
474 const struct mptcp_addr_info *remote);
475 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
477 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
478 struct mptcp_subflow_context *ctx)
480 sk->sk_data_ready = ctx->tcp_data_ready;
481 sk->sk_state_change = ctx->tcp_state_change;
482 sk->sk_write_space = ctx->tcp_write_space;
483 sk->sk_error_report = ctx->tcp_error_report;
485 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
488 void __init mptcp_proto_init(void);
489 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
490 int __init mptcp_proto_v6_init(void);
493 struct sock *mptcp_sk_clone(const struct sock *sk,
494 const struct mptcp_options_received *mp_opt,
495 struct request_sock *req);
496 void mptcp_get_options(const struct sk_buff *skb,
497 struct mptcp_options_received *mp_opt);
499 void mptcp_finish_connect(struct sock *sk);
500 static inline bool mptcp_is_fully_established(struct sock *sk)
502 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
503 READ_ONCE(mptcp_sk(sk)->fully_established);
505 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
506 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
507 bool mptcp_finish_join(struct sock *sk);
508 bool mptcp_schedule_work(struct sock *sk);
509 void __mptcp_check_push(struct sock *sk, struct sock *ssk);
510 void __mptcp_data_acked(struct sock *sk);
511 void __mptcp_error_report(struct sock *sk);
512 void mptcp_subflow_eof(struct sock *sk);
513 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
514 void __mptcp_flush_join_list(struct mptcp_sock *msk);
515 static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
517 return READ_ONCE(msk->snd_data_fin_enable) &&
518 READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
521 void mptcp_destroy_common(struct mptcp_sock *msk);
523 void __init mptcp_token_init(void);
524 static inline void mptcp_token_init_request(struct request_sock *req)
526 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
529 int mptcp_token_new_request(struct request_sock *req);
530 void mptcp_token_destroy_request(struct request_sock *req);
531 int mptcp_token_new_connect(struct sock *sk);
532 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
533 struct mptcp_sock *msk);
534 bool mptcp_token_exists(u32 token);
535 struct mptcp_sock *mptcp_token_get_sock(u32 token);
536 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
538 void mptcp_token_destroy(struct mptcp_sock *msk);
540 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
542 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
544 void __init mptcp_pm_init(void);
545 void mptcp_pm_data_init(struct mptcp_sock *msk);
546 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
547 void mptcp_pm_fully_established(struct mptcp_sock *msk);
548 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
549 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
550 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
551 struct mptcp_subflow_context *subflow);
552 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
553 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
554 const struct mptcp_addr_info *addr);
555 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
556 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);
557 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
558 struct mptcp_pm_add_entry *
559 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
560 struct mptcp_addr_info *addr);
562 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
563 const struct mptcp_addr_info *addr,
564 bool echo, bool port);
565 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
566 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id);
568 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
570 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
573 static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
575 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
578 static inline bool mptcp_pm_should_add_signal_ipv6(struct mptcp_sock *msk)
580 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_IPV6);
583 static inline bool mptcp_pm_should_add_signal_port(struct mptcp_sock *msk)
585 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_PORT);
588 static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
590 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
593 static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
595 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
597 if (family == AF_INET6)
598 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
600 len += MPTCPOPT_THMAC_LEN;
602 len += TCPOLEN_MPTCP_PORT_LEN;
607 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
608 struct mptcp_addr_info *saddr, bool *echo, bool *port);
609 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
611 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
613 void __init mptcp_pm_nl_init(void);
614 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
615 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
616 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
617 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
618 void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk);
619 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk);
620 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id);
621 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
623 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
625 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
628 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
630 static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
632 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
635 static inline bool mptcp_check_fallback(const struct sock *sk)
637 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
638 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
640 return __mptcp_check_fallback(msk);
643 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
645 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
646 pr_debug("TCP fallback already done (msk=%p)", msk);
649 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
652 static inline void mptcp_do_fallback(struct sock *sk)
654 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
655 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
657 __mptcp_do_fallback(msk);
660 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
662 static inline bool subflow_simultaneous_connect(struct sock *sk)
664 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
665 struct sock *parent = subflow->conn;
667 return sk->sk_state == TCP_ESTABLISHED &&
668 !mptcp_sk(parent)->pm.server_side &&
669 !subflow->conn_finished;
672 #ifdef CONFIG_SYN_COOKIES
673 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
674 struct sk_buff *skb);
675 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
676 struct sk_buff *skb);
677 void __init mptcp_join_cookie_init(void);
680 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
681 struct sk_buff *skb) {}
683 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
689 static inline void mptcp_join_cookie_init(void) {}
692 #endif /* __MPTCP_PROTOCOL_H */