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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_THMAC_LEN 8
87
88/* MPTCP MP_CAPABLE flags */
89#define MPTCP_VERSION_MASK (0x0F)
90#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
91#define MPTCP_CAP_EXTENSIBILITY BIT(6)
92#define MPTCP_CAP_DENY_JOIN_ID0 BIT(5)
93#define MPTCP_CAP_HMAC_SHA256 BIT(0)
94#define MPTCP_CAP_FLAG_MASK (0x1F)
95
96/* MPTCP DSS flags */
97#define MPTCP_DSS_DATA_FIN BIT(4)
98#define MPTCP_DSS_DSN64 BIT(3)
99#define MPTCP_DSS_HAS_MAP BIT(2)
100#define MPTCP_DSS_ACK64 BIT(1)
101#define MPTCP_DSS_HAS_ACK BIT(0)
102#define MPTCP_DSS_FLAG_MASK (0x1F)
103
104/* MPTCP ADD_ADDR flags */
105#define MPTCP_ADDR_ECHO BIT(0)
106
107/* MPTCP MP_PRIO flags */
108#define MPTCP_PRIO_BKUP BIT(0)
109
110/* MPTCP TCPRST flags */
111#define MPTCP_RST_TRANSIENT BIT(0)
112
113/* MPTCP socket atomic flags */
114#define MPTCP_NOSPACE 1
115#define MPTCP_WORK_RTX 2
116#define MPTCP_WORK_EOF 3
117#define MPTCP_FALLBACK_DONE 4
118#define MPTCP_WORK_CLOSE_SUBFLOW 5
119
120/* MPTCP socket release cb flags */
121#define MPTCP_PUSH_PENDING 1
122#define MPTCP_CLEAN_UNA 2
123#define MPTCP_ERROR_REPORT 3
124#define MPTCP_RETRANSMIT 4
125#define MPTCP_FLUSH_JOIN_LIST 5
126#define MPTCP_CONNECTED 6
127#define MPTCP_RESET_SCHEDULER 7
128
129struct mptcp_skb_cb {
130 u64 map_seq;
131 u64 end_seq;
132 u32 offset;
133 u8 has_rxtstamp:1;
134};
135
136#define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0]))
137
138static inline bool before64(__u64 seq1, __u64 seq2)
139{
140 return (__s64)(seq1 - seq2) < 0;
141}
142
143#define after64(seq2, seq1) before64(seq1, seq2)
144
145struct mptcp_options_received {
146 u64 sndr_key;
147 u64 rcvr_key;
148 u64 data_ack;
149 u64 data_seq;
150 u32 subflow_seq;
151 u16 data_len;
152 __sum16 csum;
153 u16 suboptions;
154 u32 token;
155 u32 nonce;
156 u16 use_map:1,
157 dsn64:1,
158 data_fin:1,
159 use_ack:1,
160 ack64:1,
161 mpc_map:1,
162 reset_reason:4,
163 reset_transient:1,
164 echo:1,
165 backup:1,
166 deny_join_id0:1,
167 __unused:2;
168 u8 join_id;
169 u64 thmac;
170 u8 hmac[MPTCPOPT_HMAC_LEN];
171 struct mptcp_addr_info addr;
172 struct mptcp_rm_list rm_list;
173 u64 ahmac;
174 u64 fail_seq;
175};
176
177static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
178{
179 return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
180 ((nib & 0xF) << 8) | field);
181}
182
183enum mptcp_pm_status {
184 MPTCP_PM_ADD_ADDR_RECEIVED,
185 MPTCP_PM_ADD_ADDR_SEND_ACK,
186 MPTCP_PM_RM_ADDR_RECEIVED,
187 MPTCP_PM_ESTABLISHED,
188 MPTCP_PM_SUBFLOW_ESTABLISHED,
189 MPTCP_PM_ALREADY_ESTABLISHED, /* persistent status, set after ESTABLISHED event */
190 MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
191 * accounted int id_avail_bitmap
192 */
193};
194
195enum mptcp_pm_type {
196 MPTCP_PM_TYPE_KERNEL = 0,
197 MPTCP_PM_TYPE_USERSPACE,
198
199 __MPTCP_PM_TYPE_NR,
200 __MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
201};
202
203/* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
204#define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
205
206enum mptcp_addr_signal_status {
207 MPTCP_ADD_ADDR_SIGNAL,
208 MPTCP_ADD_ADDR_ECHO,
209 MPTCP_RM_ADDR_SIGNAL,
210};
211
212/* max value of mptcp_addr_info.id */
213#define MPTCP_PM_MAX_ADDR_ID U8_MAX
214
215struct mptcp_pm_data {
216 struct mptcp_addr_info local;
217 struct mptcp_addr_info remote;
218 struct list_head anno_list;
219 struct list_head userspace_pm_local_addr_list;
220
221 spinlock_t lock; /*protects the whole PM data */
222
223 u8 addr_signal;
224 bool server_side;
225 bool work_pending;
226 bool accept_addr;
227 bool accept_subflow;
228 bool remote_deny_join_id0;
229 u8 add_addr_signaled;
230 u8 add_addr_accepted;
231 u8 local_addr_used;
232 u8 pm_type;
233 u8 subflows;
234 u8 status;
235 DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
236 struct mptcp_rm_list rm_list_tx;
237 struct mptcp_rm_list rm_list_rx;
238};
239
240struct mptcp_pm_addr_entry {
241 struct list_head list;
242 struct mptcp_addr_info addr;
243 u8 flags;
244 int ifindex;
245 struct socket *lsk;
246};
247
248struct mptcp_data_frag {
249 struct list_head list;
250 u64 data_seq;
251 u16 data_len;
252 u16 offset;
253 u16 overhead;
254 u16 already_sent;
255 struct page *page;
256};
257
258/* MPTCP connection sock */
259struct mptcp_sock {
260 /* inet_connection_sock must be the first member */
261 struct inet_connection_sock sk;
262 u64 local_key;
263 u64 remote_key;
264 u64 write_seq;
265 u64 snd_nxt;
266 u64 ack_seq;
267 atomic64_t rcv_wnd_sent;
268 u64 rcv_data_fin_seq;
269 int rmem_fwd_alloc;
270 struct sock *last_snd;
271 int snd_burst;
272 int old_wspace;
273 u64 recovery_snd_nxt; /* in recovery mode accept up to this seq;
274 * recovery related fields are under data_lock
275 * protection
276 */
277 u64 snd_una;
278 u64 wnd_end;
279 unsigned long timer_ival;
280 u32 token;
281 int rmem_released;
282 unsigned long flags;
283 unsigned long cb_flags;
284 unsigned long push_pending;
285 bool recovery; /* closing subflow write queue reinjected */
286 bool can_ack;
287 bool fully_established;
288 bool rcv_data_fin;
289 bool snd_data_fin_enable;
290 bool rcv_fastclose;
291 bool use_64bit_ack; /* Set when we received a 64-bit DSN */
292 bool csum_enabled;
293 bool allow_infinite_fallback;
294 u8 mpc_endpoint_id;
295 u8 recvmsg_inq:1,
296 cork:1,
297 nodelay:1,
298 fastopening:1;
299 int connect_flags;
300 struct work_struct work;
301 struct sk_buff *ooo_last_skb;
302 struct rb_root out_of_order_queue;
303 struct sk_buff_head receive_queue;
304 struct list_head conn_list;
305 struct list_head rtx_queue;
306 struct mptcp_data_frag *first_pending;
307 struct list_head join_list;
308 struct socket *subflow; /* outgoing connect/listener/!mp_capable */
309 struct sock *first;
310 struct mptcp_pm_data pm;
311 struct {
312 u32 space; /* bytes copied in last measurement window */
313 u32 copied; /* bytes copied in this measurement window */
314 u64 time; /* start time of measurement window */
315 u64 rtt_us; /* last maximum rtt of subflows */
316 } rcvq_space;
317
318 u32 setsockopt_seq;
319 char ca_name[TCP_CA_NAME_MAX];
320 struct mptcp_sock *dl_next;
321};
322
323#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
324#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
325
326#define mptcp_for_each_subflow(__msk, __subflow) \
327 list_for_each_entry(__subflow, &((__msk)->conn_list), node)
328#define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp) \
329 list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
330
331static inline void msk_owned_by_me(const struct mptcp_sock *msk)
332{
333 sock_owned_by_me((const struct sock *)msk);
334}
335
336static inline struct mptcp_sock *mptcp_sk(const struct sock *sk)
337{
338 return (struct mptcp_sock *)sk;
339}
340
341/* the msk socket don't use the backlog, also account for the bulk
342 * free memory
343 */
344static inline int __mptcp_rmem(const struct sock *sk)
345{
346 return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released);
347}
348
349static inline int __mptcp_space(const struct sock *sk)
350{
351 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - __mptcp_rmem(sk));
352}
353
354static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
355{
356 const struct mptcp_sock *msk = mptcp_sk(sk);
357
358 return READ_ONCE(msk->first_pending);
359}
360
361static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
362{
363 struct mptcp_sock *msk = mptcp_sk(sk);
364 struct mptcp_data_frag *cur;
365
366 cur = msk->first_pending;
367 return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
368 list_next_entry(cur, list);
369}
370
371static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
372{
373 struct mptcp_sock *msk = mptcp_sk(sk);
374
375 if (!msk->first_pending)
376 return NULL;
377
378 if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
379 return NULL;
380
381 return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
382}
383
384static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
385{
386 struct mptcp_sock *msk = mptcp_sk(sk);
387
388 if (msk->snd_una == READ_ONCE(msk->snd_nxt))
389 return NULL;
390
391 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
392}
393
394struct csum_pseudo_header {
395 __be64 data_seq;
396 __be32 subflow_seq;
397 __be16 data_len;
398 __sum16 csum;
399};
400
401struct mptcp_subflow_request_sock {
402 struct tcp_request_sock sk;
403 u16 mp_capable : 1,
404 mp_join : 1,
405 backup : 1,
406 csum_reqd : 1,
407 allow_join_id0 : 1;
408 u8 local_id;
409 u8 remote_id;
410 u64 local_key;
411 u64 idsn;
412 u32 token;
413 u32 ssn_offset;
414 u64 thmac;
415 u32 local_nonce;
416 u32 remote_nonce;
417 struct mptcp_sock *msk;
418 struct hlist_nulls_node token_node;
419};
420
421static inline struct mptcp_subflow_request_sock *
422mptcp_subflow_rsk(const struct request_sock *rsk)
423{
424 return (struct mptcp_subflow_request_sock *)rsk;
425}
426
427enum mptcp_data_avail {
428 MPTCP_SUBFLOW_NODATA,
429 MPTCP_SUBFLOW_DATA_AVAIL,
430};
431
432struct mptcp_delegated_action {
433 struct napi_struct napi;
434 struct list_head head;
435};
436
437DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
438
439#define MPTCP_DELEGATE_SEND 0
440#define MPTCP_DELEGATE_ACK 1
441
442/* MPTCP subflow context */
443struct mptcp_subflow_context {
444 struct list_head node;/* conn_list of subflows */
445
446 struct_group(reset,
447
448 unsigned long avg_pacing_rate; /* protected by msk socket lock */
449 u64 local_key;
450 u64 remote_key;
451 u64 idsn;
452 u64 map_seq;
453 u32 snd_isn;
454 u32 token;
455 u32 rel_write_seq;
456 u32 map_subflow_seq;
457 u32 ssn_offset;
458 u32 map_data_len;
459 __wsum map_data_csum;
460 u32 map_csum_len;
461 u32 request_mptcp : 1, /* send MP_CAPABLE */
462 request_join : 1, /* send MP_JOIN */
463 request_bkup : 1,
464 mp_capable : 1, /* remote is MPTCP capable */
465 mp_join : 1, /* remote is JOINing */
466 fully_established : 1, /* path validated */
467 pm_notified : 1, /* PM hook called for established status */
468 conn_finished : 1,
469 map_valid : 1,
470 map_csum_reqd : 1,
471 map_data_fin : 1,
472 mpc_map : 1,
473 backup : 1,
474 send_mp_prio : 1,
475 send_mp_fail : 1,
476 send_fastclose : 1,
477 send_infinite_map : 1,
478 rx_eof : 1,
479 remote_key_valid : 1, /* received the peer key from */
480 disposable : 1, /* ctx can be free at ulp release time */
481 stale : 1, /* unable to snd/rcv data, do not use for xmit */
482 local_id_valid : 1, /* local_id is correctly initialized */
483 valid_csum_seen : 1, /* at least one csum validated */
484 is_mptfo : 1, /* subflow is doing TFO */
485 __unused : 8;
486 enum mptcp_data_avail data_avail;
487 u32 remote_nonce;
488 u64 thmac;
489 u32 local_nonce;
490 u32 remote_token;
491 union {
492 u8 hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */
493 u64 iasn; /* initial ack sequence number, MPC subflows only */
494 };
495 u8 local_id;
496 u8 remote_id;
497 u8 reset_seen:1;
498 u8 reset_transient:1;
499 u8 reset_reason:4;
500 u8 stale_count;
501
502 long delegated_status;
503 unsigned long fail_tout;
504
505 );
506
507 struct list_head delegated_node; /* link into delegated_action, protected by local BH */
508
509 u32 setsockopt_seq;
510 u32 stale_rcv_tstamp;
511
512 struct sock *tcp_sock; /* tcp sk backpointer */
513 struct sock *conn; /* parent mptcp_sock */
514 const struct inet_connection_sock_af_ops *icsk_af_ops;
515 void (*tcp_state_change)(struct sock *sk);
516 void (*tcp_error_report)(struct sock *sk);
517
518 struct rcu_head rcu;
519};
520
521static inline struct mptcp_subflow_context *
522mptcp_subflow_ctx(const struct sock *sk)
523{
524 struct inet_connection_sock *icsk = inet_csk(sk);
525
526 /* Use RCU on icsk_ulp_data only for sock diag code */
527 return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
528}
529
530static inline struct sock *
531mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
532{
533 return subflow->tcp_sock;
534}
535
536static inline void
537mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
538{
539 memset(&subflow->reset, 0, sizeof(subflow->reset));
540 subflow->request_mptcp = 1;
541}
542
543static inline u64
544mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
545{
546 return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
547 subflow->ssn_offset -
548 subflow->map_subflow_seq;
549}
550
551static inline u64
552mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
553{
554 return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
555}
556
557void mptcp_subflow_process_delegated(struct sock *ssk);
558
559static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
560{
561 struct mptcp_delegated_action *delegated;
562 bool schedule;
563
564 /* the caller held the subflow bh socket lock */
565 lockdep_assert_in_softirq();
566
567 /* The implied barrier pairs with mptcp_subflow_delegated_done(), and
568 * ensures the below list check sees list updates done prior to status
569 * bit changes
570 */
571 if (!test_and_set_bit(action, &subflow->delegated_status)) {
572 /* still on delegated list from previous scheduling */
573 if (!list_empty(&subflow->delegated_node))
574 return;
575
576 delegated = this_cpu_ptr(&mptcp_delegated_actions);
577 schedule = list_empty(&delegated->head);
578 list_add_tail(&subflow->delegated_node, &delegated->head);
579 sock_hold(mptcp_subflow_tcp_sock(subflow));
580 if (schedule)
581 napi_schedule(&delegated->napi);
582 }
583}
584
585static inline struct mptcp_subflow_context *
586mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
587{
588 struct mptcp_subflow_context *ret;
589
590 if (list_empty(&delegated->head))
591 return NULL;
592
593 ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
594 list_del_init(&ret->delegated_node);
595 return ret;
596}
597
598static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow)
599{
600 return !!READ_ONCE(subflow->delegated_status);
601}
602
603static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow, int action)
604{
605 /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before
606 * touching the status bit
607 */
608 smp_wmb();
609 clear_bit(action, &subflow->delegated_status);
610}
611
612int mptcp_is_enabled(const struct net *net);
613unsigned int mptcp_get_add_addr_timeout(const struct net *net);
614int mptcp_is_checksum_enabled(const struct net *net);
615int mptcp_allow_join_id0(const struct net *net);
616unsigned int mptcp_stale_loss_cnt(const struct net *net);
617int mptcp_get_pm_type(const struct net *net);
618void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk);
619void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
620 const struct mptcp_options_received *mp_opt);
621bool __mptcp_retransmit_pending_data(struct sock *sk);
622void mptcp_check_and_set_pending(struct sock *sk);
623void __mptcp_push_pending(struct sock *sk, unsigned int flags);
624bool mptcp_subflow_data_available(struct sock *sk);
625void __init mptcp_subflow_init(void);
626void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
627void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
628 struct mptcp_subflow_context *subflow);
629void __mptcp_subflow_send_ack(struct sock *ssk);
630void mptcp_subflow_reset(struct sock *ssk);
631void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
632void mptcp_sock_graft(struct sock *sk, struct socket *parent);
633struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
634bool __mptcp_close(struct sock *sk, long timeout);
635void mptcp_cancel_work(struct sock *sk);
636void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk);
637
638bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
639 const struct mptcp_addr_info *b, bool use_port);
640
641/* called with sk socket lock held */
642int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
643 const struct mptcp_addr_info *remote);
644int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,
645 struct socket **new_sock);
646void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
647 struct sockaddr_storage *addr,
648 unsigned short family);
649
650static inline bool __tcp_can_send(const struct sock *ssk)
651{
652 /* only send if our side has not closed yet */
653 return ((1 << inet_sk_state_load(ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
654}
655
656static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
657{
658 /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
659 if (subflow->request_join && !subflow->fully_established)
660 return false;
661
662 return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
663}
664
665void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
666
667bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
668
669static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
670 struct mptcp_subflow_context *ctx)
671{
672 sk->sk_data_ready = sock_def_readable;
673 sk->sk_state_change = ctx->tcp_state_change;
674 sk->sk_write_space = sk_stream_write_space;
675 sk->sk_error_report = ctx->tcp_error_report;
676
677 inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
678}
679
680void __init mptcp_proto_init(void);
681#if IS_ENABLED(CONFIG_MPTCP_IPV6)
682int __init mptcp_proto_v6_init(void);
683#endif
684
685struct sock *mptcp_sk_clone(const struct sock *sk,
686 const struct mptcp_options_received *mp_opt,
687 struct request_sock *req);
688void mptcp_get_options(const struct sk_buff *skb,
689 struct mptcp_options_received *mp_opt);
690
691void mptcp_finish_connect(struct sock *sk);
692void __mptcp_set_connected(struct sock *sk);
693void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout);
694static inline bool mptcp_is_fully_established(struct sock *sk)
695{
696 return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
697 READ_ONCE(mptcp_sk(sk)->fully_established);
698}
699void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
700void mptcp_data_ready(struct sock *sk, struct sock *ssk);
701bool mptcp_finish_join(struct sock *sk);
702bool mptcp_schedule_work(struct sock *sk);
703int mptcp_setsockopt(struct sock *sk, int level, int optname,
704 sockptr_t optval, unsigned int optlen);
705int mptcp_getsockopt(struct sock *sk, int level, int optname,
706 char __user *optval, int __user *option);
707
708u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
709static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
710{
711 if (use_64bit)
712 return cur_seq;
713
714 return __mptcp_expand_seq(old_seq, cur_seq);
715}
716void __mptcp_check_push(struct sock *sk, struct sock *ssk);
717void __mptcp_data_acked(struct sock *sk);
718void __mptcp_error_report(struct sock *sk);
719void mptcp_subflow_eof(struct sock *sk);
720bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
721static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
722{
723 return READ_ONCE(msk->snd_data_fin_enable) &&
724 READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
725}
726
727static inline bool mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
728{
729 if ((sk->sk_userlocks & SOCK_SNDBUF_LOCK) || ssk->sk_sndbuf <= READ_ONCE(sk->sk_sndbuf))
730 return false;
731
732 WRITE_ONCE(sk->sk_sndbuf, ssk->sk_sndbuf);
733 return true;
734}
735
736static inline void mptcp_write_space(struct sock *sk)
737{
738 if (sk_stream_is_writeable(sk)) {
739 /* pairs with memory barrier in mptcp_poll */
740 smp_mb();
741 if (test_and_clear_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags))
742 sk_stream_write_space(sk);
743 }
744}
745
746void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
747
748#define MPTCP_TOKEN_MAX_RETRIES 4
749
750void __init mptcp_token_init(void);
751static inline void mptcp_token_init_request(struct request_sock *req)
752{
753 mptcp_subflow_rsk(req)->token_node.pprev = NULL;
754}
755
756int mptcp_token_new_request(struct request_sock *req);
757void mptcp_token_destroy_request(struct request_sock *req);
758int mptcp_token_new_connect(struct sock *sk);
759void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
760 struct mptcp_sock *msk);
761bool mptcp_token_exists(u32 token);
762struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
763struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
764 long *s_num);
765void mptcp_token_destroy(struct mptcp_sock *msk);
766
767void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
768
769void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
770__sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
771
772void __init mptcp_pm_init(void);
773void mptcp_pm_data_init(struct mptcp_sock *msk);
774void mptcp_pm_data_reset(struct mptcp_sock *msk);
775int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
776 struct mptcp_addr_info *addr);
777int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
778 bool require_family,
779 struct mptcp_pm_addr_entry *entry);
780bool mptcp_pm_addr_families_match(const struct sock *sk,
781 const struct mptcp_addr_info *loc,
782 const struct mptcp_addr_info *rem);
783void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
784void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
785void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
786void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp);
787bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
788void mptcp_pm_connection_closed(struct mptcp_sock *msk);
789void mptcp_pm_subflow_established(struct mptcp_sock *msk);
790bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
791void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
792 const struct mptcp_subflow_context *subflow);
793void mptcp_pm_add_addr_received(const struct sock *ssk,
794 const struct mptcp_addr_info *addr);
795void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
796 const struct mptcp_addr_info *addr);
797void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
798void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk);
799void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
800 const struct mptcp_rm_list *rm_list);
801void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
802void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
803int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
804 struct mptcp_addr_info *addr,
805 struct mptcp_addr_info *rem,
806 u8 bkup);
807bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
808 const struct mptcp_pm_addr_entry *entry);
809void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
810bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
811struct mptcp_pm_add_entry *
812mptcp_pm_del_add_timer(struct mptcp_sock *msk,
813 const struct mptcp_addr_info *addr, bool check_id);
814struct mptcp_pm_add_entry *
815mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
816 const struct mptcp_addr_info *addr);
817int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
818 unsigned int id,
819 u8 *flags, int *ifindex);
820int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
821 unsigned int id,
822 u8 *flags, int *ifindex);
823int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
824 struct mptcp_pm_addr_entry *loc,
825 struct mptcp_pm_addr_entry *rem, u8 bkup);
826int mptcp_pm_announce_addr(struct mptcp_sock *msk,
827 const struct mptcp_addr_info *addr,
828 bool echo);
829int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
830int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
831void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
832 struct list_head *rm_list);
833
834int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
835 struct mptcp_pm_addr_entry *entry);
836void mptcp_free_local_addr_list(struct mptcp_sock *msk);
837int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info);
838int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info);
839int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info);
840int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info);
841
842void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
843 const struct sock *ssk, gfp_t gfp);
844void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
845void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
846void mptcp_event_pm_listener(const struct sock *ssk,
847 enum mptcp_event_type event);
848bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
849
850void mptcp_fastopen_gen_msk_ackseq(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
851 const struct mptcp_options_received *mp_opt);
852void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow,
853 struct request_sock *req);
854
855static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
856{
857 return READ_ONCE(msk->pm.addr_signal) &
858 (BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
859}
860
861static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
862{
863 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
864}
865
866static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
867{
868 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
869}
870
871static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
872{
873 return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
874}
875
876static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
877{
878 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
879}
880
881static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
882{
883 return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
884}
885
886static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
887{
888 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
889
890 if (family == AF_INET6)
891 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
892 if (!echo)
893 len += MPTCPOPT_THMAC_LEN;
894 /* account for 2 trailing 'nop' options */
895 if (port)
896 len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
897
898 return len;
899}
900
901static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
902{
903 if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
904 return -EINVAL;
905
906 return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
907}
908
909bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
910 unsigned int opt_size, unsigned int remaining,
911 struct mptcp_addr_info *addr, bool *echo,
912 bool *drop_other_suboptions);
913bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
914 struct mptcp_rm_list *rm_list);
915int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
916int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
917
918void __init mptcp_pm_nl_init(void);
919void mptcp_pm_nl_work(struct mptcp_sock *msk);
920void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
921 const struct mptcp_rm_list *rm_list);
922int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
923unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
924unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
925unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
926unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
927
928/* called under PM lock */
929static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
930{
931 if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
932 WRITE_ONCE(msk->pm.accept_subflow, true);
933}
934
935static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
936{
937 spin_lock_bh(&msk->pm.lock);
938 __mptcp_pm_close_subflow(msk);
939 spin_unlock_bh(&msk->pm.lock);
940}
941
942void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk);
943void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
944
945static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
946{
947 return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
948}
949
950void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
951
952static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
953{
954 return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
955}
956
957static inline bool mptcp_check_fallback(const struct sock *sk)
958{
959 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
960 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
961
962 return __mptcp_check_fallback(msk);
963}
964
965static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
966{
967 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) {
968 pr_debug("TCP fallback already done (msk=%p)", msk);
969 return;
970 }
971 set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
972}
973
974static inline void mptcp_do_fallback(struct sock *ssk)
975{
976 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
977 struct sock *sk = subflow->conn;
978 struct mptcp_sock *msk;
979
980 msk = mptcp_sk(sk);
981 __mptcp_do_fallback(msk);
982 if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
983 gfp_t saved_allocation = ssk->sk_allocation;
984
985 /* we are in a atomic (BH) scope, override ssk default for data
986 * fin allocation
987 */
988 ssk->sk_allocation = GFP_ATOMIC;
989 ssk->sk_shutdown |= SEND_SHUTDOWN;
990 tcp_shutdown(ssk, SEND_SHUTDOWN);
991 ssk->sk_allocation = saved_allocation;
992 }
993}
994
995#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
996
997static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
998{
999 struct mptcp_ext *mpext;
1000
1001 mpext = skb ? mptcp_get_ext(skb) : NULL;
1002 if (mpext && mpext->infinite_map)
1003 return true;
1004
1005 return false;
1006}
1007
1008static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
1009{
1010 return (subflow->request_mptcp || subflow->request_join);
1011}
1012
1013static inline bool subflow_simultaneous_connect(struct sock *sk)
1014{
1015 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1016
1017 return sk->sk_state == TCP_ESTABLISHED &&
1018 is_active_ssk(subflow) &&
1019 !subflow->conn_finished;
1020}
1021
1022#ifdef CONFIG_SYN_COOKIES
1023void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1024 struct sk_buff *skb);
1025bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1026 struct sk_buff *skb);
1027void __init mptcp_join_cookie_init(void);
1028#else
1029static inline void
1030subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1031 struct sk_buff *skb) {}
1032static inline bool
1033mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1034 struct sk_buff *skb)
1035{
1036 return false;
1037}
1038
1039static inline void mptcp_join_cookie_init(void) {}
1040#endif
1041
1042#endif /* __MPTCP_PROTOCOL_H */