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
93 struct mptcp_options_received {
124 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
125 struct in6_addr addr6;
132 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
134 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
135 ((nib & 0xF) << 8) | field);
138 #define MPTCP_PM_MAX_ADDR 4
140 struct mptcp_addr_info {
146 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
147 struct in6_addr addr6;
152 enum mptcp_pm_status {
153 MPTCP_PM_ADD_ADDR_RECEIVED,
154 MPTCP_PM_ESTABLISHED,
155 MPTCP_PM_SUBFLOW_ESTABLISHED,
158 struct mptcp_pm_data {
159 struct mptcp_addr_info local;
160 struct mptcp_addr_info remote;
162 spinlock_t lock; /*protects the whole PM data */
169 u8 add_addr_signaled;
170 u8 add_addr_accepted;
173 u8 add_addr_signal_max;
174 u8 add_addr_accept_max;
179 struct work_struct work;
182 struct mptcp_data_frag {
183 struct list_head list;
191 /* MPTCP connection sock */
193 /* inet_connection_sock must be the first member */
194 struct inet_connection_sock sk;
200 unsigned long timer_ival;
204 spinlock_t join_list_lock;
205 struct work_struct work;
206 struct list_head conn_list;
207 struct list_head rtx_queue;
208 struct list_head join_list;
209 struct skb_ext *cached_ext; /* for the next sendmsg */
210 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
212 struct mptcp_pm_data pm;
215 #define mptcp_for_each_subflow(__msk, __subflow) \
216 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
218 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
220 return (struct mptcp_sock *)sk;
223 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
225 struct mptcp_sock *msk = mptcp_sk(sk);
227 if (list_empty(&msk->rtx_queue))
230 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
233 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
235 struct mptcp_sock *msk = mptcp_sk(sk);
237 if (list_empty(&msk->rtx_queue))
240 return list_first_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
243 struct mptcp_subflow_request_sock {
244 struct tcp_request_sock sk;
259 static inline struct mptcp_subflow_request_sock *
260 mptcp_subflow_rsk(const struct request_sock *rsk)
262 return (struct mptcp_subflow_request_sock *)rsk;
265 /* MPTCP subflow context */
266 struct mptcp_subflow_context {
267 struct list_head node;/* conn_list of subflows */
278 u32 request_mptcp : 1, /* send MP_CAPABLE */
279 request_join : 1, /* send MP_JOIN */
281 mp_capable : 1, /* remote is MPTCP capable */
282 mp_join : 1, /* remote is JOINing */
283 fully_established : 1, /* path validated */
284 pm_notified : 1, /* PM hook called for established status */
291 data_fin_tx_enable : 1,
292 use_64bit_ack : 1, /* Set when we received a 64-bit DSN */
293 can_ack : 1; /* only after processing the remote a key */
299 u8 hmac[MPTCPOPT_HMAC_LEN];
303 struct sock *tcp_sock; /* tcp sk backpointer */
304 struct sock *conn; /* parent mptcp_sock */
305 const struct inet_connection_sock_af_ops *icsk_af_ops;
306 void (*tcp_data_ready)(struct sock *sk);
307 void (*tcp_state_change)(struct sock *sk);
308 void (*tcp_write_space)(struct sock *sk);
313 static inline struct mptcp_subflow_context *
314 mptcp_subflow_ctx(const struct sock *sk)
316 struct inet_connection_sock *icsk = inet_csk(sk);
318 /* Use RCU on icsk_ulp_data only for sock diag code */
319 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
322 static inline struct sock *
323 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
325 return subflow->tcp_sock;
329 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
331 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
332 subflow->ssn_offset -
333 subflow->map_subflow_seq;
337 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
339 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
342 int mptcp_is_enabled(struct net *net);
343 bool mptcp_subflow_data_available(struct sock *sk);
344 void mptcp_subflow_init(void);
346 /* called with sk socket lock held */
347 int __mptcp_subflow_connect(struct sock *sk, int ifindex,
348 const struct mptcp_addr_info *loc,
349 const struct mptcp_addr_info *remote);
350 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
352 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
353 struct mptcp_subflow_context *ctx)
355 sk->sk_data_ready = ctx->tcp_data_ready;
356 sk->sk_state_change = ctx->tcp_state_change;
357 sk->sk_write_space = ctx->tcp_write_space;
359 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
362 extern const struct inet_connection_sock_af_ops ipv4_specific;
363 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
364 extern const struct inet_connection_sock_af_ops ipv6_specific;
367 void mptcp_proto_init(void);
368 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
369 int mptcp_proto_v6_init(void);
372 struct sock *mptcp_sk_clone(const struct sock *sk,
373 const struct mptcp_options_received *mp_opt,
374 struct request_sock *req);
375 void mptcp_get_options(const struct sk_buff *skb,
376 struct mptcp_options_received *mp_opt);
378 void mptcp_finish_connect(struct sock *sk);
379 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
380 bool mptcp_finish_join(struct sock *sk);
381 void mptcp_data_acked(struct sock *sk);
382 void mptcp_subflow_eof(struct sock *sk);
384 int mptcp_token_new_request(struct request_sock *req);
385 void mptcp_token_destroy_request(u32 token);
386 int mptcp_token_new_connect(struct sock *sk);
387 int mptcp_token_new_accept(u32 token, struct sock *conn);
388 struct mptcp_sock *mptcp_token_get_sock(u32 token);
389 void mptcp_token_destroy(u32 token);
391 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
392 static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
394 /* we might consider a faster version that computes the key as a
395 * hash of some information available in the MPTCP socket. Use
396 * random data at the moment, as it's probably the safest option
397 * in case multiple sockets are opened in different namespaces at
400 get_random_bytes(key, sizeof(u64));
401 mptcp_crypto_key_sha(*key, token, idsn);
404 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
406 void mptcp_pm_init(void);
407 void mptcp_pm_data_init(struct mptcp_sock *msk);
408 void mptcp_pm_close(struct mptcp_sock *msk);
409 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
410 void mptcp_pm_fully_established(struct mptcp_sock *msk);
411 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
412 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
413 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
414 struct mptcp_subflow_context *subflow);
415 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
416 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
417 const struct mptcp_addr_info *addr);
419 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
420 const struct mptcp_addr_info *addr);
421 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
422 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);
424 static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk)
426 return READ_ONCE(msk->pm.addr_signal);
429 static inline unsigned int mptcp_add_addr_len(int family)
431 if (family == AF_INET)
432 return TCPOLEN_MPTCP_ADD_ADDR;
433 return TCPOLEN_MPTCP_ADD_ADDR6;
436 bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
437 struct mptcp_addr_info *saddr);
438 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
440 void mptcp_pm_nl_init(void);
441 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
442 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
443 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
444 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
445 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
447 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
449 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
452 static inline bool before64(__u64 seq1, __u64 seq2)
454 return (__s64)(seq1 - seq2) < 0;
457 #define after64(seq2, seq1) before64(seq1, seq2)
459 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
461 #endif /* __MPTCP_PROTOCOL_H */