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_HMAC_LEN 20
85 #define MPTCP_ADDR_IPVERSION_4 4
86 #define MPTCP_ADDR_IPVERSION_6 6
88 /* MPTCP socket flags */
89 #define MPTCP_DATA_READY 0
90 #define MPTCP_SEND_SPACE 1
91 #define MPTCP_WORK_RTX 2
92 #define MPTCP_WORK_EOF 3
94 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
96 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
97 ((nib & 0xF) << 8) | field);
100 #define MPTCP_PM_MAX_ADDR 4
102 struct mptcp_addr_info {
108 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
109 struct in6_addr addr6;
114 enum mptcp_pm_status {
115 MPTCP_PM_ADD_ADDR_RECEIVED,
116 MPTCP_PM_ESTABLISHED,
117 MPTCP_PM_SUBFLOW_ESTABLISHED,
120 struct mptcp_pm_data {
121 struct mptcp_addr_info local;
122 struct mptcp_addr_info remote;
124 spinlock_t lock; /*protects the whole PM data */
131 u8 add_addr_signaled;
132 u8 add_addr_accepted;
135 u8 add_addr_signal_max;
136 u8 add_addr_accept_max;
141 struct work_struct work;
144 struct mptcp_data_frag {
145 struct list_head list;
153 /* MPTCP connection sock */
155 /* inet_connection_sock must be the first member */
156 struct inet_connection_sock sk;
162 unsigned long timer_ival;
166 spinlock_t join_list_lock;
167 struct work_struct work;
168 struct list_head conn_list;
169 struct list_head rtx_queue;
170 struct list_head join_list;
171 struct skb_ext *cached_ext; /* for the next sendmsg */
172 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
174 struct mptcp_pm_data pm;
177 #define mptcp_for_each_subflow(__msk, __subflow) \
178 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
180 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
182 return (struct mptcp_sock *)sk;
185 static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
187 struct mptcp_sock *msk = mptcp_sk(sk);
189 if (list_empty(&msk->rtx_queue))
192 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
195 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
197 struct mptcp_sock *msk = mptcp_sk(sk);
199 if (list_empty(&msk->rtx_queue))
202 return list_first_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
205 struct mptcp_subflow_request_sock {
206 struct tcp_request_sock sk;
221 static inline struct mptcp_subflow_request_sock *
222 mptcp_subflow_rsk(const struct request_sock *rsk)
224 return (struct mptcp_subflow_request_sock *)rsk;
227 /* MPTCP subflow context */
228 struct mptcp_subflow_context {
229 struct list_head node;/* conn_list of subflows */
240 u32 request_mptcp : 1, /* send MP_CAPABLE */
241 request_join : 1, /* send MP_JOIN */
243 mp_capable : 1, /* remote is MPTCP capable */
244 mp_join : 1, /* remote is JOINing */
245 fully_established : 1, /* path validated */
246 pm_notified : 1, /* PM hook called for established status */
253 data_fin_tx_enable : 1,
254 can_ack : 1; /* only after processing the remote a key */
260 u8 hmac[MPTCPOPT_HMAC_LEN];
264 struct sock *tcp_sock; /* tcp sk backpointer */
265 struct sock *conn; /* parent mptcp_sock */
266 const struct inet_connection_sock_af_ops *icsk_af_ops;
267 void (*tcp_data_ready)(struct sock *sk);
268 void (*tcp_state_change)(struct sock *sk);
269 void (*tcp_write_space)(struct sock *sk);
274 static inline struct mptcp_subflow_context *
275 mptcp_subflow_ctx(const struct sock *sk)
277 struct inet_connection_sock *icsk = inet_csk(sk);
279 /* Use RCU on icsk_ulp_data only for sock diag code */
280 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
283 static inline struct sock *
284 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
286 return subflow->tcp_sock;
290 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
292 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
293 subflow->ssn_offset -
294 subflow->map_subflow_seq;
298 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
300 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
303 int mptcp_is_enabled(struct net *net);
304 bool mptcp_subflow_data_available(struct sock *sk);
305 void mptcp_subflow_init(void);
307 /* called with sk socket lock held */
308 int __mptcp_subflow_connect(struct sock *sk, int ifindex,
309 const struct mptcp_addr_info *loc,
310 const struct mptcp_addr_info *remote);
311 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
313 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
314 struct mptcp_subflow_context *ctx)
316 sk->sk_data_ready = ctx->tcp_data_ready;
317 sk->sk_state_change = ctx->tcp_state_change;
318 sk->sk_write_space = ctx->tcp_write_space;
320 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
323 extern const struct inet_connection_sock_af_ops ipv4_specific;
324 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
325 extern const struct inet_connection_sock_af_ops ipv6_specific;
328 void mptcp_proto_init(void);
329 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
330 int mptcp_proto_v6_init(void);
333 struct sock *mptcp_sk_clone(const struct sock *sk,
334 const struct tcp_options_received *opt_rx,
335 struct request_sock *req);
336 void mptcp_get_options(const struct sk_buff *skb,
337 struct tcp_options_received *opt_rx);
339 void mptcp_finish_connect(struct sock *sk);
340 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
341 bool mptcp_finish_join(struct sock *sk);
342 void mptcp_data_acked(struct sock *sk);
343 void mptcp_subflow_eof(struct sock *sk);
345 int mptcp_token_new_request(struct request_sock *req);
346 void mptcp_token_destroy_request(u32 token);
347 int mptcp_token_new_connect(struct sock *sk);
348 int mptcp_token_new_accept(u32 token, struct sock *conn);
349 struct mptcp_sock *mptcp_token_get_sock(u32 token);
350 void mptcp_token_destroy(u32 token);
352 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
353 static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
355 /* we might consider a faster version that computes the key as a
356 * hash of some information available in the MPTCP socket. Use
357 * random data at the moment, as it's probably the safest option
358 * in case multiple sockets are opened in different namespaces at
361 get_random_bytes(key, sizeof(u64));
362 mptcp_crypto_key_sha(*key, token, idsn);
365 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
367 void mptcp_pm_init(void);
368 void mptcp_pm_data_init(struct mptcp_sock *msk);
369 void mptcp_pm_close(struct mptcp_sock *msk);
370 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
371 void mptcp_pm_fully_established(struct mptcp_sock *msk);
372 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
373 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
374 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
375 struct mptcp_subflow_context *subflow);
376 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
377 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
378 const struct mptcp_addr_info *addr);
380 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
381 const struct mptcp_addr_info *addr);
382 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
383 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);
385 static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk)
387 return READ_ONCE(msk->pm.addr_signal);
390 static inline unsigned int mptcp_add_addr_len(int family)
392 if (family == AF_INET)
393 return TCPOLEN_MPTCP_ADD_ADDR;
394 return TCPOLEN_MPTCP_ADD_ADDR6;
397 bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
398 struct mptcp_addr_info *saddr);
399 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
401 void mptcp_pm_nl_init(void);
402 void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
403 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
404 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
405 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
406 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
408 static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
410 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
413 static inline bool before64(__u64 seq1, __u64 seq2)
415 return (__s64)(seq1 - seq2) < 0;
418 #define after64(seq2, seq1) before64(seq1, seq2)
420 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
422 #endif /* __MPTCP_PROTOCOL_H */