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)
27 /* MPTCP option subtypes */
28 #define MPTCPOPT_MP_CAPABLE 0
29 #define MPTCPOPT_MP_JOIN 1
30 #define MPTCPOPT_DSS 2
31 #define MPTCPOPT_ADD_ADDR 3
32 #define MPTCPOPT_RM_ADDR 4
33 #define MPTCPOPT_MP_PRIO 5
34 #define MPTCPOPT_MP_FAIL 6
35 #define MPTCPOPT_MP_FASTCLOSE 7
37 /* MPTCP suboption lengths */
38 #define TCPOLEN_MPTCP_MPC_SYN 4
39 #define TCPOLEN_MPTCP_MPC_SYNACK 12
40 #define TCPOLEN_MPTCP_MPC_ACK 20
41 #define TCPOLEN_MPTCP_MPC_ACK_DATA 22
42 #define TCPOLEN_MPTCP_MPJ_SYN 12
43 #define TCPOLEN_MPTCP_MPJ_SYNACK 16
44 #define TCPOLEN_MPTCP_MPJ_ACK 24
45 #define TCPOLEN_MPTCP_DSS_BASE 4
46 #define TCPOLEN_MPTCP_DSS_ACK32 4
47 #define TCPOLEN_MPTCP_DSS_ACK64 8
48 #define TCPOLEN_MPTCP_DSS_MAP32 10
49 #define TCPOLEN_MPTCP_DSS_MAP64 14
50 #define TCPOLEN_MPTCP_DSS_CHECKSUM 2
51 #define TCPOLEN_MPTCP_ADD_ADDR 16
52 #define TCPOLEN_MPTCP_ADD_ADDR_PORT 18
53 #define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
54 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10
55 #define TCPOLEN_MPTCP_ADD_ADDR6 28
56 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30
57 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
58 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22
59 #define TCPOLEN_MPTCP_PORT_LEN 2
60 #define TCPOLEN_MPTCP_RM_ADDR_BASE 4
62 /* MPTCP MP_JOIN flags */
63 #define MPTCPOPT_BACKUP BIT(0)
64 #define MPTCPOPT_HMAC_LEN 20
65 #define MPTCPOPT_THMAC_LEN 8
67 /* MPTCP MP_CAPABLE flags */
68 #define MPTCP_VERSION_MASK (0x0F)
69 #define MPTCP_CAP_CHECKSUM_REQD BIT(7)
70 #define MPTCP_CAP_EXTENSIBILITY BIT(6)
71 #define MPTCP_CAP_HMAC_SHA256 BIT(0)
72 #define MPTCP_CAP_FLAG_MASK (0x3F)
75 #define MPTCP_DSS_DATA_FIN BIT(4)
76 #define MPTCP_DSS_DSN64 BIT(3)
77 #define MPTCP_DSS_HAS_MAP BIT(2)
78 #define MPTCP_DSS_ACK64 BIT(1)
79 #define MPTCP_DSS_HAS_ACK BIT(0)
80 #define MPTCP_DSS_FLAG_MASK (0x1F)
82 /* MPTCP ADD_ADDR flags */
83 #define MPTCP_ADDR_ECHO BIT(0)
84 #define MPTCP_ADDR_IPVERSION_4 4
85 #define MPTCP_ADDR_IPVERSION_6 6
87 /* MPTCP socket flags */
88 #define MPTCP_DATA_READY 0
89 #define MPTCP_SEND_SPACE 1
90 #define MPTCP_WORK_RTX 2
91 #define MPTCP_WORK_EOF 3
92 #define MPTCP_FALLBACK_DONE 4
93 #define MPTCP_WORK_CLOSE_SUBFLOW 5
95 struct mptcp_options_received {
126 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
127 struct in6_addr addr6;
134 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
136 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
137 ((nib & 0xF) << 8) | field);
140 struct mptcp_addr_info {
148 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
149 struct in6_addr addr6;
154 enum mptcp_pm_status {
155 MPTCP_PM_ADD_ADDR_RECEIVED,
156 MPTCP_PM_RM_ADDR_RECEIVED,
157 MPTCP_PM_ESTABLISHED,
158 MPTCP_PM_SUBFLOW_ESTABLISHED,
161 struct mptcp_pm_data {
162 struct mptcp_addr_info local;
163 struct mptcp_addr_info remote;
164 struct list_head anno_list;
166 spinlock_t lock; /*protects the whole PM data */
168 bool add_addr_signal;
175 u8 add_addr_signaled;
176 u8 add_addr_accepted;
179 u8 add_addr_signal_max;
180 u8 add_addr_accept_max;
187 struct mptcp_data_frag {
188 struct list_head list;
196 /* MPTCP connection sock */
198 /* inet_connection_sock must be the first member */
199 struct inet_connection_sock sk;
204 u64 rcv_data_fin_seq;
205 struct sock *last_snd;
208 unsigned long timer_ival;
212 bool fully_established;
214 bool snd_data_fin_enable;
215 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
216 spinlock_t join_list_lock;
217 struct work_struct work;
218 struct sk_buff *ooo_last_skb;
219 struct rb_root out_of_order_queue;
220 struct list_head conn_list;
221 struct list_head rtx_queue;
222 struct list_head join_list;
223 struct skb_ext *cached_ext; /* for the next sendmsg */
224 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
226 struct mptcp_pm_data pm;
228 u32 space; /* bytes copied in last measurement window */
229 u32 copied; /* bytes copied in this measurement window */
230 u64 time; /* start time of measurement window */
231 u64 rtt_us; /* last maximum rtt of subflows */
235 #define mptcp_for_each_subflow(__msk, __subflow) \
236 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
238 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
240 return (struct mptcp_sock *)sk;
243 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
245 struct mptcp_sock *msk = mptcp_sk(sk);
247 if (list_empty(&msk->rtx_queue))
250 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
253 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
255 struct mptcp_sock *msk = mptcp_sk(sk);
257 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
260 struct mptcp_subflow_request_sock {
261 struct tcp_request_sock sk;
274 struct mptcp_sock *msk;
275 struct hlist_nulls_node token_node;
278 static inline struct mptcp_subflow_request_sock *
279 mptcp_subflow_rsk(const struct request_sock *rsk)
281 return (struct mptcp_subflow_request_sock *)rsk;
284 enum mptcp_data_avail {
285 MPTCP_SUBFLOW_NODATA,
286 MPTCP_SUBFLOW_DATA_AVAIL,
287 MPTCP_SUBFLOW_OOO_DATA
290 /* MPTCP subflow context */
291 struct mptcp_subflow_context {
292 struct list_head node;/* conn_list of subflows */
303 u32 request_mptcp : 1, /* send MP_CAPABLE */
304 request_join : 1, /* send MP_JOIN */
306 mp_capable : 1, /* remote is MPTCP capable */
307 mp_join : 1, /* remote is JOINing */
308 fully_established : 1, /* path validated */
309 pm_notified : 1, /* PM hook called for established status */
315 can_ack : 1; /* only after processing the remote a key */
316 enum mptcp_data_avail data_avail;
321 u8 hmac[MPTCPOPT_HMAC_LEN];
325 struct sock *tcp_sock; /* tcp sk backpointer */
326 struct sock *conn; /* parent mptcp_sock */
327 const struct inet_connection_sock_af_ops *icsk_af_ops;
328 void (*tcp_data_ready)(struct sock *sk);
329 void (*tcp_state_change)(struct sock *sk);
330 void (*tcp_write_space)(struct sock *sk);
335 static inline struct mptcp_subflow_context *
336 mptcp_subflow_ctx(const struct sock *sk)
338 struct inet_connection_sock *icsk = inet_csk(sk);
340 /* Use RCU on icsk_ulp_data only for sock diag code */
341 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
344 static inline struct sock *
345 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
347 return subflow->tcp_sock;
351 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
353 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
354 subflow->ssn_offset -
355 subflow->map_subflow_seq;
359 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
361 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
364 int mptcp_is_enabled(struct net *net);
365 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
366 struct mptcp_options_received *mp_opt);
367 bool mptcp_subflow_data_available(struct sock *sk);
368 void __init mptcp_subflow_init(void);
369 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
370 void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
371 struct mptcp_subflow_context *subflow,
373 void mptcp_subflow_reset(struct sock *ssk);
375 /* called with sk socket lock held */
376 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
377 const struct mptcp_addr_info *remote);
378 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
380 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
381 struct mptcp_subflow_context *ctx)
383 sk->sk_data_ready = ctx->tcp_data_ready;
384 sk->sk_state_change = ctx->tcp_state_change;
385 sk->sk_write_space = ctx->tcp_write_space;
387 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
390 void __init mptcp_proto_init(void);
391 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
392 int __init mptcp_proto_v6_init(void);
395 struct sock *mptcp_sk_clone(const struct sock *sk,
396 const struct mptcp_options_received *mp_opt,
397 struct request_sock *req);
398 void mptcp_get_options(const struct sk_buff *skb,
399 struct mptcp_options_received *mp_opt);
401 void mptcp_finish_connect(struct sock *sk);
402 static inline bool mptcp_is_fully_established(struct sock *sk)
404 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
405 READ_ONCE(mptcp_sk(sk)->fully_established);
407 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
408 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
409 bool mptcp_finish_join(struct sock *sk);
410 void mptcp_data_acked(struct sock *sk);
411 void mptcp_subflow_eof(struct sock *sk);
412 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
413 void mptcp_destroy_common(struct mptcp_sock *msk);
415 void __init mptcp_token_init(void);
416 static inline void mptcp_token_init_request(struct request_sock *req)
418 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
421 int mptcp_token_new_request(struct request_sock *req);
422 void mptcp_token_destroy_request(struct request_sock *req);
423 int mptcp_token_new_connect(struct sock *sk);
424 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
425 struct mptcp_sock *msk);
426 bool mptcp_token_exists(u32 token);
427 struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
428 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
430 void mptcp_token_destroy(struct mptcp_sock *msk);
432 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
434 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
436 void __init mptcp_pm_init(void);
437 void mptcp_pm_data_init(struct mptcp_sock *msk);
438 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
439 void mptcp_pm_fully_established(struct mptcp_sock *msk);
440 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
441 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
442 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
443 struct mptcp_subflow_context *subflow);
444 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
445 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
446 const struct mptcp_addr_info *addr);
447 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);
448 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
449 struct mptcp_pm_add_entry *
450 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
451 struct mptcp_addr_info *addr);
453 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
454 const struct mptcp_addr_info *addr,
456 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
457 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id);
459 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
461 return READ_ONCE(msk->pm.add_addr_signal);
464 static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
466 return READ_ONCE(msk->pm.rm_addr_signal);
469 static inline unsigned int mptcp_add_addr_len(int family, bool echo)
471 if (family == AF_INET)
472 return echo ? TCPOLEN_MPTCP_ADD_ADDR_BASE
473 : TCPOLEN_MPTCP_ADD_ADDR;
474 return echo ? TCPOLEN_MPTCP_ADD_ADDR6_BASE : TCPOLEN_MPTCP_ADD_ADDR6;
477 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
478 struct mptcp_addr_info *saddr, bool *echo);
479 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
481 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
483 void __init mptcp_pm_nl_init(void);
484 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
485 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
486 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
487 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
488 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk);
489 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id);
490 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
492 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
494 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
497 static inline bool before64(__u64 seq1, __u64 seq2)
499 return (__s64)(seq1 - seq2) < 0;
502 #define after64(seq2, seq1) before64(seq1, seq2)
504 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
506 static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
508 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
511 static inline bool mptcp_check_fallback(const struct sock *sk)
513 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
514 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
516 return __mptcp_check_fallback(msk);
519 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
521 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
522 pr_debug("TCP fallback already done (msk=%p)", msk);
525 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
528 static inline void mptcp_do_fallback(struct sock *sk)
530 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
531 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
533 __mptcp_do_fallback(msk);
536 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
538 static inline bool subflow_simultaneous_connect(struct sock *sk)
540 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
541 struct sock *parent = subflow->conn;
543 return sk->sk_state == TCP_ESTABLISHED &&
544 !mptcp_sk(parent)->pm.server_side &&
545 !subflow->conn_finished;
548 #ifdef CONFIG_SYN_COOKIES
549 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
550 struct sk_buff *skb);
551 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
552 struct sk_buff *skb);
553 void __init mptcp_join_cookie_init(void);
556 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
557 struct sk_buff *skb) {}
559 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
565 static inline void mptcp_join_cookie_init(void) {}
568 #endif /* __MPTCP_PROTOCOL_H */