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7#ifndef __MPTCP_PROTOCOL_H
8#define __MPTCP_PROTOCOL_H
9
10#include <linux/random.h>
11#include <net/tcp.h>
12#include <net/inet_connection_sock.h>
13
14#define MPTCP_SUPPORTED_VERSION 1
15
16
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
27
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
36
37
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
61
62
63#define MPTCPOPT_BACKUP BIT(0)
64#define MPTCPOPT_HMAC_LEN 20
65#define MPTCPOPT_THMAC_LEN 8
66
67
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)
73
74
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)
81
82
83#define MPTCP_ADDR_ECHO BIT(0)
84#define MPTCP_ADDR_IPVERSION_4 4
85#define MPTCP_ADDR_IPVERSION_6 6
86
87
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
94
95struct mptcp_options_received {
96 u64 sndr_key;
97 u64 rcvr_key;
98 u64 data_ack;
99 u64 data_seq;
100 u32 subflow_seq;
101 u16 data_len;
102 u16 mp_capable : 1,
103 mp_join : 1,
104 dss : 1,
105 add_addr : 1,
106 rm_addr : 1,
107 family : 4,
108 echo : 1,
109 backup : 1;
110 u32 token;
111 u32 nonce;
112 u64 thmac;
113 u8 hmac[20];
114 u8 join_id;
115 u8 use_map:1,
116 dsn64:1,
117 data_fin:1,
118 use_ack:1,
119 ack64:1,
120 mpc_map:1,
121 __unused:2;
122 u8 addr_id;
123 u8 rm_id;
124 union {
125 struct in_addr addr;
126#if IS_ENABLED(CONFIG_MPTCP_IPV6)
127 struct in6_addr addr6;
128#endif
129 };
130 u64 ahmac;
131 u16 port;
132};
133
134static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
135{
136 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
137 ((nib & 0xF) << 8) | field);
138}
139
140struct mptcp_addr_info {
141 sa_family_t family;
142 __be16 port;
143 u8 id;
144 u8 flags;
145 int ifindex;
146 union {
147 struct in_addr addr;
148#if IS_ENABLED(CONFIG_MPTCP_IPV6)
149 struct in6_addr addr6;
150#endif
151 };
152};
153
154enum mptcp_pm_status {
155 MPTCP_PM_ADD_ADDR_RECEIVED,
156 MPTCP_PM_RM_ADDR_RECEIVED,
157 MPTCP_PM_ESTABLISHED,
158 MPTCP_PM_SUBFLOW_ESTABLISHED,
159};
160
161struct mptcp_pm_data {
162 struct mptcp_addr_info local;
163 struct mptcp_addr_info remote;
164 struct list_head anno_list;
165
166 spinlock_t lock;
167
168 bool add_addr_signal;
169 bool rm_addr_signal;
170 bool server_side;
171 bool work_pending;
172 bool accept_addr;
173 bool accept_subflow;
174 bool add_addr_echo;
175 u8 add_addr_signaled;
176 u8 add_addr_accepted;
177 u8 local_addr_used;
178 u8 subflows;
179 u8 add_addr_signal_max;
180 u8 add_addr_accept_max;
181 u8 local_addr_max;
182 u8 subflows_max;
183 u8 status;
184 u8 rm_id;
185};
186
187struct mptcp_data_frag {
188 struct list_head list;
189 u64 data_seq;
190 int data_len;
191 int offset;
192 int overhead;
193 struct page *page;
194};
195
196
197struct mptcp_sock {
198
199 struct inet_connection_sock sk;
200 u64 local_key;
201 u64 remote_key;
202 u64 write_seq;
203 u64 ack_seq;
204 u64 rcv_data_fin_seq;
205 struct sock *last_snd;
206 int snd_burst;
207 atomic64_t snd_una;
208 unsigned long timer_ival;
209 u32 token;
210 unsigned long flags;
211 bool can_ack;
212 bool fully_established;
213 bool rcv_data_fin;
214 bool snd_data_fin_enable;
215 bool use_64bit_ack;
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;
224 struct socket *subflow;
225 struct sock *first;
226 struct mptcp_pm_data pm;
227 struct {
228 u32 space;
229 u32 copied;
230 u64 time;
231 u64 rtt_us;
232 } rcvq_space;
233};
234
235#define mptcp_for_each_subflow(__msk, __subflow) \
236 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
237
238static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
239{
240 return (struct mptcp_sock *)sk;
241}
242
243static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
244{
245 struct mptcp_sock *msk = mptcp_sk(sk);
246
247 if (list_empty(&msk->rtx_queue))
248 return NULL;
249
250 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
251}
252
253static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
254{
255 struct mptcp_sock *msk = mptcp_sk(sk);
256
257 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
258}
259
260struct mptcp_subflow_request_sock {
261 struct tcp_request_sock sk;
262 u16 mp_capable : 1,
263 mp_join : 1,
264 backup : 1;
265 u8 local_id;
266 u8 remote_id;
267 u64 local_key;
268 u64 idsn;
269 u32 token;
270 u32 ssn_offset;
271 u64 thmac;
272 u32 local_nonce;
273 u32 remote_nonce;
274 struct mptcp_sock *msk;
275 struct hlist_nulls_node token_node;
276};
277
278static inline struct mptcp_subflow_request_sock *
279mptcp_subflow_rsk(const struct request_sock *rsk)
280{
281 return (struct mptcp_subflow_request_sock *)rsk;
282}
283
284enum mptcp_data_avail {
285 MPTCP_SUBFLOW_NODATA,
286 MPTCP_SUBFLOW_DATA_AVAIL,
287 MPTCP_SUBFLOW_OOO_DATA
288};
289
290
291struct mptcp_subflow_context {
292 struct list_head node;
293 u64 local_key;
294 u64 remote_key;
295 u64 idsn;
296 u64 map_seq;
297 u32 snd_isn;
298 u32 token;
299 u32 rel_write_seq;
300 u32 map_subflow_seq;
301 u32 ssn_offset;
302 u32 map_data_len;
303 u32 request_mptcp : 1,
304 request_join : 1,
305 request_bkup : 1,
306 mp_capable : 1,
307 mp_join : 1,
308 fully_established : 1,
309 pm_notified : 1,
310 conn_finished : 1,
311 map_valid : 1,
312 mpc_map : 1,
313 backup : 1,
314 rx_eof : 1,
315 can_ack : 1;
316 enum mptcp_data_avail data_avail;
317 u32 remote_nonce;
318 u64 thmac;
319 u32 local_nonce;
320 u32 remote_token;
321 u8 hmac[MPTCPOPT_HMAC_LEN];
322 u8 local_id;
323 u8 remote_id;
324
325 struct sock *tcp_sock;
326 struct sock *conn;
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);
331
332 struct rcu_head rcu;
333};
334
335static inline struct mptcp_subflow_context *
336mptcp_subflow_ctx(const struct sock *sk)
337{
338 struct inet_connection_sock *icsk = inet_csk(sk);
339
340
341 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
342}
343
344static inline struct sock *
345mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
346{
347 return subflow->tcp_sock;
348}
349
350static inline u64
351mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
352{
353 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
354 subflow->ssn_offset -
355 subflow->map_subflow_seq;
356}
357
358static inline u64
359mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
360{
361 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
362}
363
364int mptcp_is_enabled(struct net *net);
365void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
366 struct mptcp_options_received *mp_opt);
367bool mptcp_subflow_data_available(struct sock *sk);
368void __init mptcp_subflow_init(void);
369void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
370void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
371 struct mptcp_subflow_context *subflow,
372 long timeout);
373void mptcp_subflow_reset(struct sock *ssk);
374
375
376int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
377 const struct mptcp_addr_info *remote);
378int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
379
380static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
381 struct mptcp_subflow_context *ctx)
382{
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;
386
387 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
388}
389
390void __init mptcp_proto_init(void);
391#if IS_ENABLED(CONFIG_MPTCP_IPV6)
392int __init mptcp_proto_v6_init(void);
393#endif
394
395struct sock *mptcp_sk_clone(const struct sock *sk,
396 const struct mptcp_options_received *mp_opt,
397 struct request_sock *req);
398void mptcp_get_options(const struct sk_buff *skb,
399 struct mptcp_options_received *mp_opt);
400
401void mptcp_finish_connect(struct sock *sk);
402static inline bool mptcp_is_fully_established(struct sock *sk)
403{
404 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
405 READ_ONCE(mptcp_sk(sk)->fully_established);
406}
407void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
408void mptcp_data_ready(struct sock *sk, struct sock *ssk);
409bool mptcp_finish_join(struct sock *sk);
410void mptcp_data_acked(struct sock *sk);
411void mptcp_subflow_eof(struct sock *sk);
412bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
413void mptcp_destroy_common(struct mptcp_sock *msk);
414
415void __init mptcp_token_init(void);
416static inline void mptcp_token_init_request(struct request_sock *req)
417{
418 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
419}
420
421int mptcp_token_new_request(struct request_sock *req);
422void mptcp_token_destroy_request(struct request_sock *req);
423int mptcp_token_new_connect(struct sock *sk);
424void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
425 struct mptcp_sock *msk);
426bool mptcp_token_exists(u32 token);
427struct mptcp_sock *mptcp_token_get_sock(u32 token);
428struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
429 long *s_num);
430void mptcp_token_destroy(struct mptcp_sock *msk);
431
432void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
433
434void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
435
436void __init mptcp_pm_init(void);
437void mptcp_pm_data_init(struct mptcp_sock *msk);
438void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
439void mptcp_pm_fully_established(struct mptcp_sock *msk);
440bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
441void mptcp_pm_connection_closed(struct mptcp_sock *msk);
442void mptcp_pm_subflow_established(struct mptcp_sock *msk,
443 struct mptcp_subflow_context *subflow);
444void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
445void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
446 const struct mptcp_addr_info *addr);
447void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);
448void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
449struct mptcp_pm_add_entry *
450mptcp_pm_del_add_timer(struct mptcp_sock *msk,
451 struct mptcp_addr_info *addr);
452
453int mptcp_pm_announce_addr(struct mptcp_sock *msk,
454 const struct mptcp_addr_info *addr,
455 bool echo);
456int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
457int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id);
458
459static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
460{
461 return READ_ONCE(msk->pm.add_addr_signal);
462}
463
464static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
465{
466 return READ_ONCE(msk->pm.rm_addr_signal);
467}
468
469static inline unsigned int mptcp_add_addr_len(int family, bool echo)
470{
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;
475}
476
477bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
478 struct mptcp_addr_info *saddr, bool *echo);
479bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
480 u8 *rm_id);
481int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
482
483void __init mptcp_pm_nl_init(void);
484void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
485void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
486void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
487void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
488void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk);
489void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id);
490int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
491
492static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
493{
494 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
495}
496
497static inline bool before64(__u64 seq1, __u64 seq2)
498{
499 return (__s64)(seq1 - seq2) < 0;
500}
501
502#define after64(seq2, seq1) before64(seq1, seq2)
503
504void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
505
506static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
507{
508 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
509}
510
511static inline bool mptcp_check_fallback(const struct sock *sk)
512{
513 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
514 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
515
516 return __mptcp_check_fallback(msk);
517}
518
519static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
520{
521 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
522 pr_debug("TCP fallback already done (msk=%p)", msk);
523 return;
524 }
525 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
526}
527
528static inline void mptcp_do_fallback(struct sock *sk)
529{
530 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
531 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
532
533 __mptcp_do_fallback(msk);
534}
535
536#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
537
538static inline bool subflow_simultaneous_connect(struct sock *sk)
539{
540 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
541 struct sock *parent = subflow->conn;
542
543 return sk->sk_state == TCP_ESTABLISHED &&
544 !mptcp_sk(parent)->pm.server_side &&
545 !subflow->conn_finished;
546}
547
548#ifdef CONFIG_SYN_COOKIES
549void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
550 struct sk_buff *skb);
551bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
552 struct sk_buff *skb);
553void __init mptcp_join_cookie_init(void);
554#else
555static inline void
556subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
557 struct sk_buff *skb) {}
558static inline bool
559mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
560 struct sk_buff *skb)
561{
562 return false;
563}
564
565static inline void mptcp_join_cookie_init(void) {}
566#endif
567
568#endif
569
