1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Multipath TCP
3 *
4 * Copyright (c) 2017 - 2019, Intel Corporation.
5 */
6
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 #include <uapi/linux/mptcp.h>
14 #include <net/genetlink.h>
15
16 #define MPTCP_SUPPORTED_VERSION 1
17
18 /* MPTCP option bits */
19 #define OPTION_MPTCP_MPC_SYN BIT(0)
20 #define OPTION_MPTCP_MPC_SYNACK BIT(1)
21 #define OPTION_MPTCP_MPC_ACK BIT(2)
22 #define OPTION_MPTCP_MPJ_SYN BIT(3)
23 #define OPTION_MPTCP_MPJ_SYNACK BIT(4)
24 #define OPTION_MPTCP_MPJ_ACK BIT(5)
25 #define OPTION_MPTCP_ADD_ADDR BIT(6)
26 #define OPTION_MPTCP_RM_ADDR BIT(7)
27 #define OPTION_MPTCP_FASTCLOSE BIT(8)
28 #define OPTION_MPTCP_PRIO BIT(9)
29 #define OPTION_MPTCP_RST BIT(10)
30 #define OPTION_MPTCP_DSS BIT(11)
31 #define OPTION_MPTCP_FAIL BIT(12)
32
33 #define OPTION_MPTCP_CSUMREQD BIT(13)
34
35 #define OPTIONS_MPTCP_MPC (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
36 OPTION_MPTCP_MPC_ACK)
37 #define OPTIONS_MPTCP_MPJ (OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
38 OPTION_MPTCP_MPJ_ACK)
39
40 /* MPTCP option subtypes */
41 #define MPTCPOPT_MP_CAPABLE 0
42 #define MPTCPOPT_MP_JOIN 1
43 #define MPTCPOPT_DSS 2
44 #define MPTCPOPT_ADD_ADDR 3
45 #define MPTCPOPT_RM_ADDR 4
46 #define MPTCPOPT_MP_PRIO 5
47 #define MPTCPOPT_MP_FAIL 6
48 #define MPTCPOPT_MP_FASTCLOSE 7
49 #define MPTCPOPT_RST 8
50
51 /* MPTCP suboption lengths */
52 #define TCPOLEN_MPTCP_MPC_SYN 4
53 #define TCPOLEN_MPTCP_MPC_SYNACK 12
54 #define TCPOLEN_MPTCP_MPC_ACK 20
55 #define TCPOLEN_MPTCP_MPC_ACK_DATA 22
56 #define TCPOLEN_MPTCP_MPJ_SYN 12
57 #define TCPOLEN_MPTCP_MPJ_SYNACK 16
58 #define TCPOLEN_MPTCP_MPJ_ACK 24
59 #define TCPOLEN_MPTCP_DSS_BASE 4
60 #define TCPOLEN_MPTCP_DSS_ACK32 4
61 #define TCPOLEN_MPTCP_DSS_ACK64 8
62 #define TCPOLEN_MPTCP_DSS_MAP32 10
63 #define TCPOLEN_MPTCP_DSS_MAP64 14
64 #define TCPOLEN_MPTCP_DSS_CHECKSUM 2
65 #define TCPOLEN_MPTCP_ADD_ADDR 16
66 #define TCPOLEN_MPTCP_ADD_ADDR_PORT 18
67 #define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
68 #define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10
69 #define TCPOLEN_MPTCP_ADD_ADDR6 28
70 #define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30
71 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
72 #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22
73 #define TCPOLEN_MPTCP_PORT_LEN 2
74 #define TCPOLEN_MPTCP_PORT_ALIGN 2
75 #define TCPOLEN_MPTCP_RM_ADDR_BASE 3
76 #define TCPOLEN_MPTCP_PRIO 3
77 #define TCPOLEN_MPTCP_PRIO_ALIGN 4
78 #define TCPOLEN_MPTCP_FASTCLOSE 12
79 #define TCPOLEN_MPTCP_RST 4
80 #define TCPOLEN_MPTCP_FAIL 12
81
82 #define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
83
84 /* MPTCP MP_JOIN flags */
85 #define MPTCPOPT_BACKUP BIT(0)
86 #define MPTCPOPT_HMAC_LEN 20
87 #define MPTCPOPT_THMAC_LEN 8
88
89 /* MPTCP MP_CAPABLE flags */
90 #define MPTCP_VERSION_MASK (0x0F)
91 #define MPTCP_CAP_CHECKSUM_REQD BIT(7)
92 #define MPTCP_CAP_EXTENSIBILITY BIT(6)
93 #define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
94 #define MPTCP_CAP_HMAC_SHA256 BIT(0)
95 #define MPTCP_CAP_FLAG_MASK (0x1F)
96
97 /* MPTCP DSS flags */
98 #define MPTCP_DSS_DATA_FIN BIT(4)
99 #define MPTCP_DSS_DSN64 BIT(3)
100 #define MPTCP_DSS_HAS_MAP BIT(2)
101 #define MPTCP_DSS_ACK64 BIT(1)
102 #define MPTCP_DSS_HAS_ACK BIT(0)
103 #define MPTCP_DSS_FLAG_MASK (0x1F)
104
105 /* MPTCP ADD_ADDR flags */
106 #define MPTCP_ADDR_ECHO BIT(0)
107
108 /* MPTCP MP_PRIO flags */
109 #define MPTCP_PRIO_BKUP BIT(0)
110
111 /* MPTCP TCPRST flags */
112 #define MPTCP_RST_TRANSIENT BIT(0)
113
114 /* MPTCP socket atomic flags */
115 #define MPTCP_NOSPACE 1
116 #define MPTCP_WORK_RTX 2
117 #define MPTCP_WORK_EOF 3
118 #define MPTCP_FALLBACK_DONE 4
119 #define MPTCP_WORK_CLOSE_SUBFLOW 5
120
121 /* MPTCP socket release cb flags */
122 #define MPTCP_PUSH_PENDING 1
123 #define MPTCP_CLEAN_UNA 2
124 #define MPTCP_ERROR_REPORT 3
125 #define MPTCP_RETRANSMIT 4
126 #define MPTCP_FLUSH_JOIN_LIST 5
127 #define MPTCP_CONNECTED 6
128 #define MPTCP_RESET_SCHEDULER 7
129
before64(__u64 seq1,__u64 seq2)130 static inline bool before64(__u64 seq1, __u64 seq2)
131 {
132 return (__s64)(seq1 - seq2) < 0;
133 }
134
135 #define after64(seq2, seq1) before64(seq1, seq2)
136
137 struct mptcp_options_received {
138 u64 sndr_key;
139 u64 rcvr_key;
140 u64 data_ack;
141 u64 data_seq;
142 u32 subflow_seq;
143 u16 data_len;
144 __sum16 csum;
145 u16 suboptions;
146 u32 token;
147 u32 nonce;
148 u16 use_map:1,
149 dsn64:1,
150 data_fin:1,
151 use_ack:1,
152 ack64:1,
153 mpc_map:1,
154 reset_reason:4,
155 reset_transient:1,
156 echo:1,
157 backup:1,
158 deny_join_id0:1,
159 __unused:2;
160 u8 join_id;
161 u64 thmac;
162 u8 hmac[MPTCPOPT_HMAC_LEN];
163 struct mptcp_addr_info addr;
164 struct mptcp_rm_list rm_list;
165 u64 ahmac;
166 u64 fail_seq;
167 };
168
mptcp_option(u8 subopt,u8 len,u8 nib,u8 field)169 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
170 {
171 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
172 ((nib & 0xF) << 8) | field);
173 }
174
175 enum mptcp_pm_status {
176 MPTCP_PM_ADD_ADDR_RECEIVED,
177 MPTCP_PM_ADD_ADDR_SEND_ACK,
178 MPTCP_PM_RM_ADDR_RECEIVED,
179 MPTCP_PM_ESTABLISHED,
180 MPTCP_PM_SUBFLOW_ESTABLISHED,
181 MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */
182 MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
183 * accounted int id_avail_bitmap
184 */
185 };
186
187 enum mptcp_pm_type {
188 MPTCP_PM_TYPE_KERNEL = 0,
189 MPTCP_PM_TYPE_USERSPACE,
190
191 __MPTCP_PM_TYPE_NR,
192 __MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
193 };
194
195 /* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
196 #define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
197
198 enum mptcp_addr_signal_status {
199 MPTCP_ADD_ADDR_SIGNAL,
200 MPTCP_ADD_ADDR_ECHO,
201 MPTCP_RM_ADDR_SIGNAL,
202 };
203
204 /* max value of mptcp_addr_info.id */
205 #define MPTCP_PM_MAX_ADDR_ID U8_MAX
206
207 struct mptcp_pm_data {
208 struct mptcp_addr_info local;
209 struct mptcp_addr_info remote;
210 struct list_head anno_list;
211 struct list_head userspace_pm_local_addr_list;
212
213 spinlock_t lock; /*protects the whole PM data */
214
215 u8 addr_signal;
216 bool server_side;
217 bool work_pending;
218 bool accept_addr;
219 bool accept_subflow;
220 bool remote_deny_join_id0;
221 u8 add_addr_signaled;
222 u8 add_addr_accepted;
223 u8 local_addr_used;
224 u8 pm_type;
225 u8 subflows;
226 u8 status;
227 DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
228 struct mptcp_rm_list rm_list_tx;
229 struct mptcp_rm_list rm_list_rx;
230 };
231
232 struct mptcp_pm_addr_entry {
233 struct list_head list;
234 struct mptcp_addr_info addr;
235 u8 flags;
236 int ifindex;
237 struct socket *lsk;
238 };
239
240 struct mptcp_data_frag {
241 struct list_head list;
242 u64 data_seq;
243 u16 data_len;
244 u16 offset;
245 u16 overhead;
246 u16 already_sent;
247 struct page *page;
248 };
249
250 /* MPTCP connection sock */
251 struct mptcp_sock {
252 /* inet_connection_sock must be the first member */
253 struct inet_connection_sock sk;
254 u64 local_key;
255 u64 remote_key;
256 u64 write_seq;
257 u64 snd_nxt;
258 u64 ack_seq;
259 atomic64_t rcv_wnd_sent;
260 u64 rcv_data_fin_seq;
261 int rmem_fwd_alloc;
262 struct sock *last_snd;
263 int snd_burst;
264 int old_wspace;
265 u64 recovery_snd_nxt; /* in recovery mode accept up to this seq;
266 * recovery related fields are under data_lock
267 * protection
268 */
269 u64 snd_una;
270 u64 wnd_end;
271 unsigned long timer_ival;
272 u32 token;
273 int rmem_released;
274 unsigned long flags;
275 unsigned long cb_flags;
276 unsigned long push_pending;
277 bool recovery; /* closing subflow write queue reinjected */
278 bool can_ack;
279 bool fully_established;
280 bool rcv_data_fin;
281 bool snd_data_fin_enable;
282 bool rcv_fastclose;
283 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
284 bool csum_enabled;
285 bool allow_infinite_fallback;
286 u8 recvmsg_inq:1,
287 cork:1,
288 nodelay:1;
289 struct work_struct work;
290 struct sk_buff *ooo_last_skb;
291 struct rb_root out_of_order_queue;
292 struct sk_buff_head receive_queue;
293 struct list_head conn_list;
294 struct list_head rtx_queue;
295 struct mptcp_data_frag *first_pending;
296 struct list_head join_list;
297 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
298 struct sock *first;
299 struct mptcp_pm_data pm;
300 struct {
301 u32 space; /* bytes copied in last measurement window */
302 u32 copied; /* bytes copied in this measurement window */
303 u64 time; /* start time of measurement window */
304 u64 rtt_us; /* last maximum rtt of subflows */
305 } rcvq_space;
306
307 u32 setsockopt_seq;
308 char ca_name[TCP_CA_NAME_MAX];
309 struct mptcp_sock *dl_next;
310 };
311
312 #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
313 #define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
314
315 #define mptcp_for_each_subflow(__msk, __subflow) \
316 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
317
msk_owned_by_me(const struct mptcp_sock * msk)318 static inline void msk_owned_by_me(const struct mptcp_sock *msk)
319 {
320 sock_owned_by_me((const struct sock *)msk);
321 }
322
mptcp_sk(const struct sock * sk)323 static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
324 {
325 return (struct mptcp_sock *)sk;
326 }
327
328 /* the msk socket don't use the backlog, also account for the bulk
329 * free memory
330 */
__mptcp_rmem(const struct sock * sk)331 static inline int __mptcp_rmem(const struct sock *sk)
332 {
333 return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
334 }
335
__mptcp_space(const struct sock * sk)336 static inline int __mptcp_space(const struct sock *sk)
337 {
338 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
339 }
340
mptcp_send_head(const struct sock * sk)341 static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
342 {
343 const struct mptcp_sock *msk = mptcp_sk(sk);
344
345 return READ_ONCE(msk->first_pending);
346 }
347
mptcp_send_next(struct sock * sk)348 static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
349 {
350 struct mptcp_sock *msk = mptcp_sk(sk);
351 struct mptcp_data_frag *cur;
352
353 cur = msk->first_pending;
354 return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
355 list_next_entry(cur, list);
356 }
357
mptcp_pending_tail(const struct sock * sk)358 static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
359 {
360 struct mptcp_sock *msk = mptcp_sk(sk);
361
362 if (!msk->first_pending)
363 return NULL;
364
365 if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
366 return NULL;
367
368 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
369 }
370
mptcp_rtx_head(const struct sock * sk)371 static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
372 {
373 struct mptcp_sock *msk = mptcp_sk(sk);
374
375 if (msk->snd_una == READ_ONCE(msk->snd_nxt))
376 return NULL;
377
378 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
379 }
380
381 struct csum_pseudo_header {
382 __be64 data_seq;
383 __be32 subflow_seq;
384 __be16 data_len;
385 __sum16 csum;
386 };
387
388 struct mptcp_subflow_request_sock {
389 struct tcp_request_sock sk;
390 u16 mp_capable : 1,
391 mp_join : 1,
392 backup : 1,
393 csum_reqd : 1,
394 allow_join_id0 : 1;
395 u8 local_id;
396 u8 remote_id;
397 u64 local_key;
398 u64 idsn;
399 u32 token;
400 u32 ssn_offset;
401 u64 thmac;
402 u32 local_nonce;
403 u32 remote_nonce;
404 struct mptcp_sock *msk;
405 struct hlist_nulls_node token_node;
406 };
407
408 static inline struct mptcp_subflow_request_sock *
mptcp_subflow_rsk(const struct request_sock * rsk)409 mptcp_subflow_rsk(const struct request_sock *rsk)
410 {
411 return (struct mptcp_subflow_request_sock *)rsk;
412 }
413
414 enum mptcp_data_avail {
415 MPTCP_SUBFLOW_NODATA,
416 MPTCP_SUBFLOW_DATA_AVAIL,
417 };
418
419 struct mptcp_delegated_action {
420 struct napi_struct napi;
421 struct list_head head;
422 };
423
424 DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
425
426 #define MPTCP_DELEGATE_SEND 0
427 #define MPTCP_DELEGATE_ACK 1
428
429 /* MPTCP subflow context */
430 struct mptcp_subflow_context {
431 struct list_head node;/* conn_list of subflows */
432
433 struct_group(reset,
434
435 unsigned long avg_pacing_rate; /* protected by msk socket lock */
436 u64 local_key;
437 u64 remote_key;
438 u64 idsn;
439 u64 map_seq;
440 u32 snd_isn;
441 u32 token;
442 u32 rel_write_seq;
443 u32 map_subflow_seq;
444 u32 ssn_offset;
445 u32 map_data_len;
446 __wsum map_data_csum;
447 u32 map_csum_len;
448 u32 request_mptcp : 1, /* send MP_CAPABLE */
449 request_join : 1, /* send MP_JOIN */
450 request_bkup : 1,
451 mp_capable : 1, /* remote is MPTCP capable */
452 mp_join : 1, /* remote is JOINing */
453 fully_established : 1, /* path validated */
454 pm_notified : 1, /* PM hook called for established status */
455 conn_finished : 1,
456 map_valid : 1,
457 map_csum_reqd : 1,
458 map_data_fin : 1,
459 mpc_map : 1,
460 backup : 1,
461 send_mp_prio : 1,
462 send_mp_fail : 1,
463 send_fastclose : 1,
464 send_infinite_map : 1,
465 rx_eof : 1,
466 can_ack : 1, /* only after processing the remote a key */
467 disposable : 1, /* ctx can be free at ulp release time */
468 stale : 1, /* unable to snd/rcv data, do not use for xmit */
469 local_id_valid : 1, /* local_id is correctly initialized */
470 valid_csum_seen : 1; /* at least one csum validated */
471 enum mptcp_data_avail data_avail;
472 u32 remote_nonce;
473 u64 thmac;
474 u32 local_nonce;
475 u32 remote_token;
476 u8 hmac[MPTCPOPT_HMAC_LEN];
477 u8 local_id;
478 u8 remote_id;
479 u8 reset_seen:1;
480 u8 reset_transient:1;
481 u8 reset_reason:4;
482 u8 stale_count;
483
484 long delegated_status;
485 unsigned long fail_tout;
486
487 );
488
489 struct list_head delegated_node; /* link into delegated_action, protected by local BH */
490
491 u32 setsockopt_seq;
492 u32 stale_rcv_tstamp;
493
494 struct sock *tcp_sock; /* tcp sk backpointer */
495 struct sock *conn; /* parent mptcp_sock */
496 const struct inet_connection_sock_af_ops *icsk_af_ops;
497 void (*tcp_state_change)(struct sock *sk);
498 void (*tcp_error_report)(struct sock *sk);
499
500 struct rcu_head rcu;
501 };
502
503 static inline struct mptcp_subflow_context *
mptcp_subflow_ctx(const struct sock * sk)504 mptcp_subflow_ctx(const struct sock *sk)
505 {
506 struct inet_connection_sock *icsk = inet_csk(sk);
507
508 /* Use RCU on icsk_ulp_data only for sock diag code */
509 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
510 }
511
512 static inline struct sock *
mptcp_subflow_tcp_sock(const struct mptcp_subflow_context * subflow)513 mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
514 {
515 return subflow->tcp_sock;
516 }
517
518 static inline void
mptcp_subflow_ctx_reset(struct mptcp_subflow_context * subflow)519 mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
520 {
521 memset(&subflow->reset, 0, sizeof(subflow->reset));
522 subflow->request_mptcp = 1;
523 }
524
525 static inline u64
mptcp_subflow_get_map_offset(const struct mptcp_subflow_context * subflow)526 mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
527 {
528 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
529 subflow->ssn_offset -
530 subflow->map_subflow_seq;
531 }
532
533 static inline u64
mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context * subflow)534 mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
535 {
536 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
537 }
538
539 void mptcp_subflow_process_delegated(struct sock *ssk);
540
mptcp_subflow_delegate(struct mptcp_subflow_context * subflow,int action)541 static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
542 {
543 struct mptcp_delegated_action *delegated;
544 bool schedule;
545
546 /* the caller held the subflow bh socket lock */
547 lockdep_assert_in_softirq();
548
549 /* The implied barrier pairs with mptcp_subflow_delegated_done(), and
550 * ensures the below list check sees list updates done prior to status
551 * bit changes
552 */
553 if (!test_and_set_bit(action, &subflow->delegated_status)) {
554 /* still on delegated list from previous scheduling */
555 if (!list_empty(&subflow->delegated_node))
556 return;
557
558 delegated = this_cpu_ptr(&mptcp_delegated_actions);
559 schedule = list_empty(&delegated->head);
560 list_add_tail(&subflow->delegated_node, &delegated->head);
561 sock_hold(mptcp_subflow_tcp_sock(subflow));
562 if (schedule)
563 napi_schedule(&delegated->napi);
564 }
565 }
566
567 static inline struct mptcp_subflow_context *
mptcp_subflow_delegated_next(struct mptcp_delegated_action * delegated)568 mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
569 {
570 struct mptcp_subflow_context *ret;
571
572 if (list_empty(&delegated->head))
573 return NULL;
574
575 ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
576 list_del_init(&ret->delegated_node);
577 return ret;
578 }
579
mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context * subflow)580 static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
581 {
582 return !!READ_ONCE(subflow->delegated_status);
583 }
584
mptcp_subflow_delegated_done(struct mptcp_subflow_context * subflow,int action)585 static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow, int action)
586 {
587 /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
588 * touching the status bit
589 */
590 smp_wmb();
591 clear_bit(action, &subflow->delegated_status);
592 }
593
594 int mptcp_is_enabled(const struct net *net);
595 unsigned int mptcp_get_add_addr_timeout(const struct net *net);
596 int mptcp_is_checksum_enabled(const struct net *net);
597 int mptcp_allow_join_id0(const struct net *net);
598 unsigned int mptcp_stale_loss_cnt(const struct net *net);
599 int mptcp_get_pm_type(const struct net *net);
600 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
601 struct mptcp_options_received *mp_opt);
602 bool __mptcp_retransmit_pending_data(struct sock *sk);
603 void mptcp_check_and_set_pending(struct sock *sk);
604 void __mptcp_push_pending(struct sock *sk, unsigned int flags);
605 bool mptcp_subflow_data_available(struct sock *sk);
606 void __init mptcp_subflow_init(void);
607 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
608 void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
609 struct mptcp_subflow_context *subflow);
610 void __mptcp_subflow_send_ack(struct sock *ssk);
611 void mptcp_subflow_send_ack(struct sock *ssk);
612 void mptcp_subflow_reset(struct sock *ssk);
613 void mptcp_subflow_queue_clean(struct sock *ssk);
614 void mptcp_sock_graft(struct sock *sk, struct socket *parent);
615 struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
616
617 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
618 const struct mptcp_addr_info *b, bool use_port);
619
620 /* called with sk socket lock held */
621 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
622 const struct mptcp_addr_info *remote);
623 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);
624 void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
625 struct sockaddr_storage *addr,
626 unsigned short family);
627
__tcp_can_send(const struct sock * ssk)628 static inline bool __tcp_can_send(const struct sock *ssk)
629 {
630 /* only send if our side has not closed yet */
631 return ((1 << inet_sk_state_load(ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
632 }
633
__mptcp_subflow_active(struct mptcp_subflow_context * subflow)634 static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
635 {
636 /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
637 if (subflow->request_join && !subflow->fully_established)
638 return false;
639
640 return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
641 }
642
643 void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
644
645 bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
646
mptcp_subflow_tcp_fallback(struct sock * sk,struct mptcp_subflow_context * ctx)647 static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
648 struct mptcp_subflow_context *ctx)
649 {
650 sk->sk_data_ready = sock_def_readable;
651 sk->sk_state_change = ctx->tcp_state_change;
652 sk->sk_write_space = sk_stream_write_space;
653 sk->sk_error_report = ctx->tcp_error_report;
654
655 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
656 }
657
658 void __init mptcp_proto_init(void);
659 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
660 int __init mptcp_proto_v6_init(void);
661 #endif
662
663 struct sock *mptcp_sk_clone(const struct sock *sk,
664 const struct mptcp_options_received *mp_opt,
665 struct request_sock *req);
666 void mptcp_get_options(const struct sk_buff *skb,
667 struct mptcp_options_received *mp_opt);
668
669 void mptcp_finish_connect(struct sock *sk);
670 void __mptcp_set_connected(struct sock *sk);
671 void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout);
mptcp_is_fully_established(struct sock * sk)672 static inline bool mptcp_is_fully_established(struct sock *sk)
673 {
674 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
675 READ_ONCE(mptcp_sk(sk)->fully_established);
676 }
677 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
678 void mptcp_data_ready(struct sock *sk, struct sock *ssk);
679 bool mptcp_finish_join(struct sock *sk);
680 bool mptcp_schedule_work(struct sock *sk);
681 int mptcp_setsockopt(struct sock *sk, int level, int optname,
682 sockptr_t optval, unsigned int optlen);
683 int mptcp_getsockopt(struct sock *sk, int level, int optname,
684 char __user *optval, int __user *option);
685
686 u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
mptcp_expand_seq(u64 old_seq,u64 cur_seq,bool use_64bit)687 static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
688 {
689 if (use_64bit)
690 return cur_seq;
691
692 return __mptcp_expand_seq(old_seq, cur_seq);
693 }
694 void __mptcp_check_push(struct sock *sk, struct sock *ssk);
695 void __mptcp_data_acked(struct sock *sk);
696 void __mptcp_error_report(struct sock *sk);
697 void mptcp_subflow_eof(struct sock *sk);
698 bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
mptcp_data_fin_enabled(const struct mptcp_sock * msk)699 static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
700 {
701 return READ_ONCE(msk->snd_data_fin_enable) &&
702 READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
703 }
704
mptcp_propagate_sndbuf(struct sock * sk,struct sock * ssk)705 static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
706 {
707 if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
708 return false;
709
710 WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
711 return true;
712 }
713
mptcp_write_space(struct sock * sk)714 static inline void mptcp_write_space(struct sock *sk)
715 {
716 if (sk_stream_is_writeable(sk)) {
717 /* pairs with memory barrier in mptcp_poll */
718 smp_mb();
719 if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
720 sk_stream_write_space(sk);
721 }
722 }
723
724 void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
725
726 #define MPTCP_TOKEN_MAX_RETRIES 4
727
728 void __init mptcp_token_init(void);
mptcp_token_init_request(struct request_sock * req)729 static inline void mptcp_token_init_request(struct request_sock *req)
730 {
731 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
732 }
733
734 int mptcp_token_new_request(struct request_sock *req);
735 void mptcp_token_destroy_request(struct request_sock *req);
736 int mptcp_token_new_connect(struct sock *sk);
737 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
738 struct mptcp_sock *msk);
739 bool mptcp_token_exists(u32 token);
740 struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
741 struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
742 long *s_num);
743 void mptcp_token_destroy(struct mptcp_sock *msk);
744
745 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
746
747 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
748 __sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
749
750 void __init mptcp_pm_init(void);
751 void mptcp_pm_data_init(struct mptcp_sock *msk);
752 void mptcp_pm_data_reset(struct mptcp_sock *msk);
753 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
754 struct mptcp_addr_info *addr);
755 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
756 bool require_family,
757 struct mptcp_pm_addr_entry *entry);
758 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
759 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
760 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
761 void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
762 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
763 void mptcp_pm_connection_closed(struct mptcp_sock *msk);
764 void mptcp_pm_subflow_established(struct mptcp_sock *msk);
765 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
766 void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
767 const struct mptcp_subflow_context *subflow);
768 void mptcp_pm_add_addr_received(const struct sock *ssk,
769 const struct mptcp_addr_info *addr);
770 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
771 const struct mptcp_addr_info *addr);
772 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
773 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
774 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
775 const struct mptcp_rm_list *rm_list);
776 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
777 void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
778 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
779 struct mptcp_addr_info *addr,
780 struct mptcp_addr_info *rem,
781 u8 bkup);
782 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
783 const struct mptcp_pm_addr_entry *entry);
784 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
785 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
786 struct mptcp_pm_add_entry *
787 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
788 const struct mptcp_addr_info *addr, bool check_id);
789 struct mptcp_pm_add_entry *
790 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
791 const struct mptcp_addr_info *addr);
792 int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
793 unsigned int id,
794 u8 *flags, int *ifindex);
795 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
796 unsigned int id,
797 u8 *flags, int *ifindex);
798 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
799 struct mptcp_pm_addr_entry *loc,
800 struct mptcp_pm_addr_entry *rem, u8 bkup);
801 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
802 const struct mptcp_addr_info *addr,
803 bool echo);
804 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
805 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
806 void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
807 struct list_head *rm_list);
808
809 int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
810 struct mptcp_pm_addr_entry *entry);
811 void mptcp_free_local_addr_list(struct mptcp_sock *msk);
812 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info);
813 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info);
814 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info);
815 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info);
816
817 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
818 const struct sock *ssk, gfp_t gfp);
819 void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
820 void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
821 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
822
mptcp_pm_should_add_signal(struct mptcp_sock * msk)823 static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
824 {
825 return READ_ONCE(msk->pm.addr_signal) &
826 (BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
827 }
828
mptcp_pm_should_add_signal_addr(struct mptcp_sock * msk)829 static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
830 {
831 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
832 }
833
mptcp_pm_should_add_signal_echo(struct mptcp_sock * msk)834 static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
835 {
836 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
837 }
838
mptcp_pm_should_rm_signal(struct mptcp_sock * msk)839 static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
840 {
841 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
842 }
843
mptcp_pm_is_userspace(const struct mptcp_sock * msk)844 static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
845 {
846 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
847 }
848
mptcp_pm_is_kernel(const struct mptcp_sock * msk)849 static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
850 {
851 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
852 }
853
mptcp_add_addr_len(int family,bool echo,bool port)854 static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
855 {
856 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
857
858 if (family == AF_INET6)
859 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
860 if (!echo)
861 len += MPTCPOPT_THMAC_LEN;
862 /* account for 2 trailing 'nop' options */
863 if (port)
864 len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
865
866 return len;
867 }
868
mptcp_rm_addr_len(const struct mptcp_rm_list * rm_list)869 static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
870 {
871 if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
872 return -EINVAL;
873
874 return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
875 }
876
877 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
878 unsigned int opt_size, unsigned int remaining,
879 struct mptcp_addr_info *addr, bool *echo,
880 bool *drop_other_suboptions);
881 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
882 struct mptcp_rm_list *rm_list);
883 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
884 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
885
886 void __init mptcp_pm_nl_init(void);
887 void mptcp_pm_nl_work(struct mptcp_sock *msk);
888 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
889 const struct mptcp_rm_list *rm_list);
890 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
891 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
892 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
893 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
894 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
895
896 /* called under PM lock */
__mptcp_pm_close_subflow(struct mptcp_sock * msk)897 static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
898 {
899 if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
900 WRITE_ONCE(msk->pm.accept_subflow, true);
901 }
902
mptcp_pm_close_subflow(struct mptcp_sock * msk)903 static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
904 {
905 spin_lock_bh(&msk->pm.lock);
906 __mptcp_pm_close_subflow(msk);
907 spin_unlock_bh(&msk->pm.lock);
908 }
909
910 void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
911 void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
912
mptcp_get_ext(const struct sk_buff * skb)913 static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
914 {
915 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
916 }
917
918 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
919
__mptcp_check_fallback(const struct mptcp_sock * msk)920 static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
921 {
922 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
923 }
924
mptcp_check_fallback(const struct sock * sk)925 static inline bool mptcp_check_fallback(const struct sock *sk)
926 {
927 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
928 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
929
930 return __mptcp_check_fallback(msk);
931 }
932
__mptcp_do_fallback(struct mptcp_sock * msk)933 static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
934 {
935 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
936 pr_debug("TCP fallback already done (msk=%p)", msk);
937 return;
938 }
939 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
940 }
941
mptcp_do_fallback(struct sock * ssk)942 static inline void mptcp_do_fallback(struct sock *ssk)
943 {
944 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
945 struct sock *sk = subflow->conn;
946 struct mptcp_sock *msk;
947
948 msk = mptcp_sk(sk);
949 __mptcp_do_fallback(msk);
950 if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
951 gfp_t saved_allocation = ssk->sk_allocation;
952
953 /* we are in a atomic (BH) scope, override ssk default for data
954 * fin allocation
955 */
956 ssk->sk_allocation = GFP_ATOMIC;
957 ssk->sk_shutdown |= SEND_SHUTDOWN;
958 tcp_shutdown(ssk, SEND_SHUTDOWN);
959 ssk->sk_allocation = saved_allocation;
960 }
961 }
962
963 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
964
mptcp_check_infinite_map(struct sk_buff * skb)965 static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
966 {
967 struct mptcp_ext *mpext;
968
969 mpext = skb ? mptcp_get_ext(skb) : NULL;
970 if (mpext && mpext->infinite_map)
971 return true;
972
973 return false;
974 }
975
is_active_ssk(struct mptcp_subflow_context * subflow)976 static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
977 {
978 return (subflow->request_mptcp || subflow->request_join);
979 }
980
subflow_simultaneous_connect(struct sock * sk)981 static inline bool subflow_simultaneous_connect(struct sock *sk)
982 {
983 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
984
985 return sk->sk_state == TCP_ESTABLISHED &&
986 is_active_ssk(subflow) &&
987 !subflow->conn_finished;
988 }
989
990 #ifdef CONFIG_SYN_COOKIES
991 void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
992 struct sk_buff *skb);
993 bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
994 struct sk_buff *skb);
995 void __init mptcp_join_cookie_init(void);
996 #else
997 static inline void
subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock * subflow_req,struct sk_buff * skb)998 subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
999 struct sk_buff *skb) {}
1000 static inline bool
mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock * subflow_req,struct sk_buff * skb)1001 mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1002 struct sk_buff *skb)
1003 {
1004 return false;
1005 }
1006
mptcp_join_cookie_init(void)1007 static inline void mptcp_join_cookie_init(void) {}
1008 #endif
1009
1010 #endif /* __MPTCP_PROTOCOL_H */
1011