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
94 struct mptcp_options_received {
125 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
126 struct in6_addr addr6;
133 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
135 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
136 ((nib & 0xF) << 8) | field);
139 struct mptcp_addr_info {
145 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
146 struct in6_addr addr6;
151 enum mptcp_pm_status {
152 MPTCP_PM_ADD_ADDR_RECEIVED,
153 MPTCP_PM_ESTABLISHED,
154 MPTCP_PM_SUBFLOW_ESTABLISHED,
157 struct mptcp_pm_data {
158 struct mptcp_addr_info local;
159 struct mptcp_addr_info remote;
161 spinlock_t lock; /*protects the whole PM data */
168 u8 add_addr_signaled;
169 u8 add_addr_accepted;
172 u8 add_addr_signal_max;
173 u8 add_addr_accept_max;
179 struct mptcp_data_frag {
180 struct list_head list;
188 /* MPTCP connection sock */
190 /* inet_connection_sock must be the first member */
191 struct inet_connection_sock sk;
196 u64 rcv_data_fin_seq;
198 unsigned long timer_ival;
202 bool fully_established;
204 bool snd_data_fin_enable;
205 spinlock_t join_list_lock;
206 struct work_struct work;
207 struct list_head conn_list;
208 struct list_head rtx_queue;
209 struct list_head join_list;
210 struct skb_ext *cached_ext; /* for the next sendmsg */
211 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
213 struct mptcp_pm_data pm;
215 u32 space; /* bytes copied in last measurement window */
216 u32 copied; /* bytes copied in this measurement window */
217 u64 time; /* start time of measurement window */
218 u64 rtt_us; /* last maximum rtt of subflows */
222 #define mptcp_for_each_subflow(__msk, __subflow) \
223 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
225 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
227 return (struct mptcp_sock *)sk;
230 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
232 struct mptcp_sock *msk = mptcp_sk(sk);
234 if (list_empty(&msk->rtx_queue))
237 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
240 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
242 struct mptcp_sock *msk = mptcp_sk(sk);
244 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
247 struct mptcp_subflow_request_sock {
248 struct tcp_request_sock sk;
261 struct mptcp_sock *msk;
262 struct hlist_nulls_node token_node;
265 static inline struct mptcp_subflow_request_sock *
266 mptcp_subflow_rsk(const struct request_sock *rsk)
268 return (struct mptcp_subflow_request_sock *)rsk;
271 /* MPTCP subflow context */
272 struct mptcp_subflow_context {
273 struct list_head node;/* conn_list of subflows */
284 u32 request_mptcp : 1, /* send MP_CAPABLE */
285 request_join : 1, /* send MP_JOIN */
287 mp_capable : 1, /* remote is MPTCP capable */
288 mp_join : 1, /* remote is JOINing */
289 fully_established : 1, /* path validated */
290 pm_notified : 1, /* PM hook called for established status */
297 use_64bit_ack : 1, /* Set when we received a 64-bit DSN */
298 can_ack : 1; /* only after processing the remote a key */
303 u8 hmac[MPTCPOPT_HMAC_LEN];
307 struct sock *tcp_sock; /* tcp sk backpointer */
308 struct sock *conn; /* parent mptcp_sock */
309 const struct inet_connection_sock_af_ops *icsk_af_ops;
310 void (*tcp_data_ready)(struct sock *sk);
311 void (*tcp_state_change)(struct sock *sk);
312 void (*tcp_write_space)(struct sock *sk);
317 static inline struct mptcp_subflow_context *
318 mptcp_subflow_ctx(const struct sock *sk)
320 struct inet_connection_sock *icsk = inet_csk(sk);
322 /* Use RCU on icsk_ulp_data only for sock diag code */
323 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
326 static inline struct sock *
327 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
329 return subflow->tcp_sock;
333 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
335 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
336 subflow->ssn_offset -
337 subflow->map_subflow_seq;
341 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
343 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
346 int mptcp_is_enabled(struct net *net);
347 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
348 struct mptcp_options_received *mp_opt);
349 bool mptcp_subflow_data_available(struct sock *sk);
350 void __init mptcp_subflow_init(void);
352 /* called with sk socket lock held */
353 int __mptcp_subflow_connect(struct sock *sk, int ifindex,
354 const struct mptcp_addr_info *loc,
355 const struct mptcp_addr_info *remote);
356 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
358 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
359 struct mptcp_subflow_context *ctx)
361 sk->sk_data_ready = ctx->tcp_data_ready;
362 sk->sk_state_change = ctx->tcp_state_change;
363 sk->sk_write_space = ctx->tcp_write_space;
365 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
368 void __init mptcp_proto_init(void);
369 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
370 int __init mptcp_proto_v6_init(void);
373 struct sock *mptcp_sk_clone(const struct sock *sk,
374 const struct mptcp_options_received *mp_opt,
375 struct request_sock *req);
376 void mptcp_get_options(const struct sk_buff *skb,
377 struct mptcp_options_received *mp_opt);
379 void mptcp_finish_connect(struct sock *sk);
380 static inline bool mptcp_is_fully_established(struct sock *sk)
382 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
383 READ_ONCE(mptcp_sk(sk)->fully_established);
385 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
386 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
387 bool mptcp_finish_join(struct sock *sk);
388 void mptcp_data_acked(struct sock *sk);
389 void mptcp_subflow_eof(struct sock *sk);
390 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq);
392 void __init mptcp_token_init(void);
393 static inline void mptcp_token_init_request(struct request_sock *req)
395 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
398 int mptcp_token_new_request(struct request_sock *req);
399 void mptcp_token_destroy_request(struct request_sock *req);
400 int mptcp_token_new_connect(struct sock *sk);
401 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
402 struct mptcp_sock *msk);
403 bool mptcp_token_exists(u32 token);
404 struct mptcp_sock *mptcp_token_get_sock(u32 token);
405 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
407 void mptcp_token_destroy(struct mptcp_sock *msk);
409 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
411 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
413 void __init mptcp_pm_init(void);
414 void mptcp_pm_data_init(struct mptcp_sock *msk);
415 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
416 void mptcp_pm_fully_established(struct mptcp_sock *msk);
417 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
418 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
419 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
420 struct mptcp_subflow_context *subflow);
421 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
422 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
423 const struct mptcp_addr_info *addr);
425 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
426 const struct mptcp_addr_info *addr);
427 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
428 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);
430 static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk)
432 return READ_ONCE(msk->pm.addr_signal);
435 static inline unsigned int mptcp_add_addr_len(int family)
437 if (family == AF_INET)
438 return TCPOLEN_MPTCP_ADD_ADDR;
439 return TCPOLEN_MPTCP_ADD_ADDR6;
442 bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
443 struct mptcp_addr_info *saddr);
444 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
446 void __init mptcp_pm_nl_init(void);
447 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
448 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
449 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
450 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
451 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
453 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
455 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
458 static inline bool before64(__u64 seq1, __u64 seq2)
460 return (__s64)(seq1 - seq2) < 0;
463 #define after64(seq2, seq1) before64(seq1, seq2)
465 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
467 static inline bool __mptcp_check_fallback(struct mptcp_sock *msk)
469 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
472 static inline bool mptcp_check_fallback(struct sock *sk)
474 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
475 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
477 return __mptcp_check_fallback(msk);
480 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
482 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
483 pr_debug("TCP fallback already done (msk=%p)", msk);
486 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
489 static inline void mptcp_do_fallback(struct sock *sk)
491 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
492 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
494 __mptcp_do_fallback(msk);
497 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
499 static inline bool subflow_simultaneous_connect(struct sock *sk)
501 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
502 struct sock *parent = subflow->conn;
504 return sk->sk_state == TCP_ESTABLISHED &&
505 !mptcp_sk(parent)->pm.server_side &&
506 !subflow->conn_finished;
509 #ifdef CONFIG_SYN_COOKIES
510 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
511 struct sk_buff *skb);
512 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
513 struct sk_buff *skb);
514 void __init mptcp_join_cookie_init(void);
517 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
518 struct sk_buff *skb) {}
520 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
526 static inline void mptcp_join_cookie_init(void) {}
529 #endif /* __MPTCP_PROTOCOL_H */