1
2
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4
5
6
7#define pr_fmt(fmt) "MPTCP: " fmt
8
9#include <linux/kernel.h>
10#include <crypto/sha2.h>
11#include <net/tcp.h>
12#include <net/mptcp.h>
13#include "protocol.h"
14#include "mib.h"
15
16#include <trace/events/mptcp.h>
17
18static bool mptcp_cap_flag_sha256(u8 flags)
19{
20 return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256;
21}
22
23static void mptcp_parse_option(const struct sk_buff *skb,
24 const unsigned char *ptr, int opsize,
25 struct mptcp_options_received *mp_opt)
26{
27 u8 subtype = *ptr >> 4;
28 int expected_opsize;
29 u8 version;
30 u8 flags;
31 u8 i;
32
33 switch (subtype) {
34 case MPTCPOPT_MP_CAPABLE:
35
36 if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
37 if (skb->len > tcp_hdr(skb)->doff << 2)
38 expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA;
39 else
40 expected_opsize = TCPOLEN_MPTCP_MPC_ACK;
41 } else {
42 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)
43 expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK;
44 else
45 expected_opsize = TCPOLEN_MPTCP_MPC_SYN;
46 }
47
48
49
50
51
52
53
54
55
56
57
58 if (opsize != expected_opsize &&
59 (expected_opsize != TCPOLEN_MPTCP_MPC_ACK_DATA ||
60 opsize != TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM))
61 break;
62
63
64 version = *ptr++ & MPTCP_VERSION_MASK;
65 if (opsize != TCPOLEN_MPTCP_MPC_SYN) {
66 if (version != MPTCP_SUPPORTED_VERSION)
67 break;
68 } else if (version < MPTCP_SUPPORTED_VERSION) {
69 break;
70 }
71
72 flags = *ptr++;
73 if (!mptcp_cap_flag_sha256(flags) ||
74 (flags & MPTCP_CAP_EXTENSIBILITY))
75 break;
76
77
78
79
80
81
82
83 if (flags & MPTCP_CAP_CHECKSUM_REQD)
84 mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD;
85
86 mp_opt->deny_join_id0 = !!(flags & MPTCP_CAP_DENY_JOIN_ID0);
87
88 mp_opt->suboptions |= OPTIONS_MPTCP_MPC;
89 if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) {
90 mp_opt->sndr_key = get_unaligned_be64(ptr);
91 ptr += 8;
92 }
93 if (opsize >= TCPOLEN_MPTCP_MPC_ACK) {
94 mp_opt->rcvr_key = get_unaligned_be64(ptr);
95 ptr += 8;
96 }
97 if (opsize >= TCPOLEN_MPTCP_MPC_ACK_DATA) {
98
99
100
101
102
103 mp_opt->suboptions |= OPTION_MPTCP_DSS;
104 mp_opt->use_map = 1;
105 mp_opt->mpc_map = 1;
106 mp_opt->data_len = get_unaligned_be16(ptr);
107 ptr += 2;
108 }
109 if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM) {
110 mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);
111 mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD;
112 ptr += 2;
113 }
114 pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d csum=%u",
115 version, flags, opsize, mp_opt->sndr_key,
116 mp_opt->rcvr_key, mp_opt->data_len, mp_opt->csum);
117 break;
118
119 case MPTCPOPT_MP_JOIN:
120 mp_opt->suboptions |= OPTIONS_MPTCP_MPJ;
121 if (opsize == TCPOLEN_MPTCP_MPJ_SYN) {
122 mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;
123 mp_opt->join_id = *ptr++;
124 mp_opt->token = get_unaligned_be32(ptr);
125 ptr += 4;
126 mp_opt->nonce = get_unaligned_be32(ptr);
127 ptr += 4;
128 pr_debug("MP_JOIN bkup=%u, id=%u, token=%u, nonce=%u",
129 mp_opt->backup, mp_opt->join_id,
130 mp_opt->token, mp_opt->nonce);
131 } else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) {
132 mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP;
133 mp_opt->join_id = *ptr++;
134 mp_opt->thmac = get_unaligned_be64(ptr);
135 ptr += 8;
136 mp_opt->nonce = get_unaligned_be32(ptr);
137 ptr += 4;
138 pr_debug("MP_JOIN bkup=%u, id=%u, thmac=%llu, nonce=%u",
139 mp_opt->backup, mp_opt->join_id,
140 mp_opt->thmac, mp_opt->nonce);
141 } else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) {
142 ptr += 2;
143 memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN);
144 pr_debug("MP_JOIN hmac");
145 } else {
146 mp_opt->suboptions &= ~OPTIONS_MPTCP_MPJ;
147 }
148 break;
149
150 case MPTCPOPT_DSS:
151 pr_debug("DSS");
152 ptr++;
153
154
155
156
157
158 mp_opt->mpc_map = 0;
159 flags = (*ptr++) & MPTCP_DSS_FLAG_MASK;
160 mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0;
161 mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0;
162 mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0;
163 mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0;
164 mp_opt->use_ack = (flags & MPTCP_DSS_HAS_ACK);
165
166 pr_debug("data_fin=%d dsn64=%d use_map=%d ack64=%d use_ack=%d",
167 mp_opt->data_fin, mp_opt->dsn64,
168 mp_opt->use_map, mp_opt->ack64,
169 mp_opt->use_ack);
170
171 expected_opsize = TCPOLEN_MPTCP_DSS_BASE;
172
173 if (mp_opt->use_ack) {
174 if (mp_opt->ack64)
175 expected_opsize += TCPOLEN_MPTCP_DSS_ACK64;
176 else
177 expected_opsize += TCPOLEN_MPTCP_DSS_ACK32;
178 }
179
180 if (mp_opt->use_map) {
181 if (mp_opt->dsn64)
182 expected_opsize += TCPOLEN_MPTCP_DSS_MAP64;
183 else
184 expected_opsize += TCPOLEN_MPTCP_DSS_MAP32;
185 }
186
187
188
189
190 if (opsize != expected_opsize &&
191 opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM)
192 break;
193
194 mp_opt->suboptions |= OPTION_MPTCP_DSS;
195 if (mp_opt->use_ack) {
196 if (mp_opt->ack64) {
197 mp_opt->data_ack = get_unaligned_be64(ptr);
198 ptr += 8;
199 } else {
200 mp_opt->data_ack = get_unaligned_be32(ptr);
201 ptr += 4;
202 }
203
204 pr_debug("data_ack=%llu", mp_opt->data_ack);
205 }
206
207 if (mp_opt->use_map) {
208 if (mp_opt->dsn64) {
209 mp_opt->data_seq = get_unaligned_be64(ptr);
210 ptr += 8;
211 } else {
212 mp_opt->data_seq = get_unaligned_be32(ptr);
213 ptr += 4;
214 }
215
216 mp_opt->subflow_seq = get_unaligned_be32(ptr);
217 ptr += 4;
218
219 mp_opt->data_len = get_unaligned_be16(ptr);
220 ptr += 2;
221
222 if (opsize == expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) {
223 mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD;
224 mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);
225 ptr += 2;
226 }
227
228 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u csum=%d:%u",
229 mp_opt->data_seq, mp_opt->subflow_seq,
230 mp_opt->data_len, !!(mp_opt->suboptions & OPTION_MPTCP_CSUMREQD),
231 mp_opt->csum);
232 }
233
234 break;
235
236 case MPTCPOPT_ADD_ADDR:
237 mp_opt->echo = (*ptr++) & MPTCP_ADDR_ECHO;
238 if (!mp_opt->echo) {
239 if (opsize == TCPOLEN_MPTCP_ADD_ADDR ||
240 opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT)
241 mp_opt->addr.family = AF_INET;
242#if IS_ENABLED(CONFIG_MPTCP_IPV6)
243 else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6 ||
244 opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT)
245 mp_opt->addr.family = AF_INET6;
246#endif
247 else
248 break;
249 } else {
250 if (opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE ||
251 opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT)
252 mp_opt->addr.family = AF_INET;
253#if IS_ENABLED(CONFIG_MPTCP_IPV6)
254 else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE ||
255 opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT)
256 mp_opt->addr.family = AF_INET6;
257#endif
258 else
259 break;
260 }
261
262 mp_opt->suboptions |= OPTION_MPTCP_ADD_ADDR;
263 mp_opt->addr.id = *ptr++;
264 mp_opt->addr.port = 0;
265 mp_opt->ahmac = 0;
266 if (mp_opt->addr.family == AF_INET) {
267 memcpy((u8 *)&mp_opt->addr.addr.s_addr, (u8 *)ptr, 4);
268 ptr += 4;
269 if (opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT ||
270 opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) {
271 mp_opt->addr.port = htons(get_unaligned_be16(ptr));
272 ptr += 2;
273 }
274 }
275#if IS_ENABLED(CONFIG_MPTCP_IPV6)
276 else {
277 memcpy(mp_opt->addr.addr6.s6_addr, (u8 *)ptr, 16);
278 ptr += 16;
279 if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT ||
280 opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) {
281 mp_opt->addr.port = htons(get_unaligned_be16(ptr));
282 ptr += 2;
283 }
284 }
285#endif
286 if (!mp_opt->echo) {
287 mp_opt->ahmac = get_unaligned_be64(ptr);
288 ptr += 8;
289 }
290 pr_debug("ADD_ADDR%s: id=%d, ahmac=%llu, echo=%d, port=%d",
291 (mp_opt->addr.family == AF_INET6) ? "6" : "",
292 mp_opt->addr.id, mp_opt->ahmac, mp_opt->echo, ntohs(mp_opt->addr.port));
293 break;
294
295 case MPTCPOPT_RM_ADDR:
296 if (opsize < TCPOLEN_MPTCP_RM_ADDR_BASE + 1 ||
297 opsize > TCPOLEN_MPTCP_RM_ADDR_BASE + MPTCP_RM_IDS_MAX)
298 break;
299
300 ptr++;
301
302 mp_opt->suboptions |= OPTION_MPTCP_RM_ADDR;
303 mp_opt->rm_list.nr = opsize - TCPOLEN_MPTCP_RM_ADDR_BASE;
304 for (i = 0; i < mp_opt->rm_list.nr; i++)
305 mp_opt->rm_list.ids[i] = *ptr++;
306 pr_debug("RM_ADDR: rm_list_nr=%d", mp_opt->rm_list.nr);
307 break;
308
309 case MPTCPOPT_MP_PRIO:
310 if (opsize != TCPOLEN_MPTCP_PRIO)
311 break;
312
313 mp_opt->suboptions |= OPTION_MPTCP_PRIO;
314 mp_opt->backup = *ptr++ & MPTCP_PRIO_BKUP;
315 pr_debug("MP_PRIO: prio=%d", mp_opt->backup);
316 break;
317
318 case MPTCPOPT_MP_FASTCLOSE:
319 if (opsize != TCPOLEN_MPTCP_FASTCLOSE)
320 break;
321
322 ptr += 2;
323 mp_opt->rcvr_key = get_unaligned_be64(ptr);
324 ptr += 8;
325 mp_opt->suboptions |= OPTION_MPTCP_FASTCLOSE;
326 break;
327
328 case MPTCPOPT_RST:
329 if (opsize != TCPOLEN_MPTCP_RST)
330 break;
331
332 if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST))
333 break;
334
335 mp_opt->suboptions |= OPTION_MPTCP_RST;
336 flags = *ptr++;
337 mp_opt->reset_transient = flags & MPTCP_RST_TRANSIENT;
338 mp_opt->reset_reason = *ptr;
339 break;
340
341 case MPTCPOPT_MP_FAIL:
342 if (opsize != TCPOLEN_MPTCP_FAIL)
343 break;
344
345 ptr += 2;
346 mp_opt->suboptions |= OPTION_MPTCP_FAIL;
347 mp_opt->fail_seq = get_unaligned_be64(ptr);
348 pr_debug("MP_FAIL: data_seq=%llu", mp_opt->fail_seq);
349 break;
350
351 default:
352 break;
353 }
354}
355
356void mptcp_get_options(const struct sock *sk,
357 const struct sk_buff *skb,
358 struct mptcp_options_received *mp_opt)
359{
360 const struct tcphdr *th = tcp_hdr(skb);
361 const unsigned char *ptr;
362 int length;
363
364
365 mp_opt->suboptions = 0;
366
367 length = (th->doff * 4) - sizeof(struct tcphdr);
368 ptr = (const unsigned char *)(th + 1);
369
370 while (length > 0) {
371 int opcode = *ptr++;
372 int opsize;
373
374 switch (opcode) {
375 case TCPOPT_EOL:
376 return;
377 case TCPOPT_NOP:
378 length--;
379 continue;
380 default:
381 if (length < 2)
382 return;
383 opsize = *ptr++;
384 if (opsize < 2)
385 return;
386 if (opsize > length)
387 return;
388 if (opcode == TCPOPT_MPTCP)
389 mptcp_parse_option(skb, ptr, opsize, mp_opt);
390 ptr += opsize - 2;
391 length -= opsize;
392 }
393 }
394}
395
396bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
397 unsigned int *size, struct mptcp_out_options *opts)
398{
399 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
400
401
402
403
404 subflow->snd_isn = TCP_SKB_CB(skb)->end_seq;
405 if (subflow->request_mptcp) {
406 opts->suboptions = OPTION_MPTCP_MPC_SYN;
407 opts->csum_reqd = mptcp_is_checksum_enabled(sock_net(sk));
408 opts->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk));
409 *size = TCPOLEN_MPTCP_MPC_SYN;
410 return true;
411 } else if (subflow->request_join) {
412 pr_debug("remote_token=%u, nonce=%u", subflow->remote_token,
413 subflow->local_nonce);
414 opts->suboptions = OPTION_MPTCP_MPJ_SYN;
415 opts->join_id = subflow->local_id;
416 opts->token = subflow->remote_token;
417 opts->nonce = subflow->local_nonce;
418 opts->backup = subflow->request_bkup;
419 *size = TCPOLEN_MPTCP_MPJ_SYN;
420 return true;
421 }
422 return false;
423}
424
425static void clear_3rdack_retransmission(struct sock *sk)
426{
427 struct inet_connection_sock *icsk = inet_csk(sk);
428
429 sk_stop_timer(sk, &icsk->icsk_delack_timer);
430 icsk->icsk_ack.timeout = 0;
431 icsk->icsk_ack.ato = 0;
432 icsk->icsk_ack.pending &= ~(ICSK_ACK_SCHED | ICSK_ACK_TIMER);
433}
434
435static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb,
436 bool snd_data_fin_enable,
437 unsigned int *size,
438 unsigned int remaining,
439 struct mptcp_out_options *opts)
440{
441 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
442 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
443 struct mptcp_ext *mpext;
444 unsigned int data_len;
445 u8 len;
446
447
448
449
450
451
452
453 if (!skb)
454 return false;
455
456
457 if (subflow->fully_established || snd_data_fin_enable ||
458 subflow->snd_isn != TCP_SKB_CB(skb)->seq ||
459 sk->sk_state != TCP_ESTABLISHED)
460 return false;
461
462 if (subflow->mp_capable) {
463 mpext = mptcp_get_ext(skb);
464 data_len = mpext ? mpext->data_len : 0;
465
466
467
468
469
470 opts->data_len = data_len;
471 opts->suboptions = OPTION_MPTCP_MPC_ACK;
472 opts->sndr_key = subflow->local_key;
473 opts->rcvr_key = subflow->remote_key;
474 opts->csum_reqd = READ_ONCE(msk->csum_enabled);
475 opts->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk));
476
477
478
479
480
481
482 if (data_len > 0) {
483 len = TCPOLEN_MPTCP_MPC_ACK_DATA;
484 if (opts->csum_reqd) {
485
486 opts->data_seq = mpext->data_seq;
487 opts->subflow_seq = mpext->subflow_seq;
488 opts->csum = mpext->csum;
489 len += TCPOLEN_MPTCP_DSS_CHECKSUM;
490 }
491 *size = ALIGN(len, 4);
492 } else {
493 *size = TCPOLEN_MPTCP_MPC_ACK;
494 }
495
496 pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d",
497 subflow, subflow->local_key, subflow->remote_key,
498 data_len);
499
500 return true;
501 } else if (subflow->mp_join) {
502 opts->suboptions = OPTION_MPTCP_MPJ_ACK;
503 memcpy(opts->hmac, subflow->hmac, MPTCPOPT_HMAC_LEN);
504 *size = TCPOLEN_MPTCP_MPJ_ACK;
505 pr_debug("subflow=%p", subflow);
506
507
508
509
510
511
512 if (sock_owned_by_user(sk))
513 set_bit(MPTCP_DELEGATE_ACK, &subflow->delegated_status);
514 else
515 mptcp_subflow_delegate(subflow, MPTCP_DELEGATE_ACK);
516 return true;
517 }
518 return false;
519}
520
521static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow,
522 struct sk_buff *skb, struct mptcp_ext *ext)
523{
524
525
526
527 u64 data_fin_tx_seq = READ_ONCE(mptcp_sk(subflow->conn)->write_seq) - 1;
528
529 if (!ext->use_map || !skb->len) {
530
531
532
533 ext->data_fin = 1;
534 ext->use_map = 1;
535 ext->dsn64 = 1;
536 ext->data_seq = data_fin_tx_seq;
537 ext->subflow_seq = 0;
538 ext->data_len = 1;
539 } else if (ext->data_seq + ext->data_len == data_fin_tx_seq) {
540
541
542
543
544 ext->data_fin = 1;
545 ext->data_len++;
546 }
547}
548
549static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
550 bool snd_data_fin_enable,
551 unsigned int *size,
552 unsigned int remaining,
553 struct mptcp_out_options *opts)
554{
555 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
556 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
557 unsigned int dss_size = 0;
558 struct mptcp_ext *mpext;
559 unsigned int ack_size;
560 bool ret = false;
561 u64 ack_seq;
562
563 opts->csum_reqd = READ_ONCE(msk->csum_enabled);
564 mpext = skb ? mptcp_get_ext(skb) : NULL;
565
566 if (!skb || (mpext && mpext->use_map) || snd_data_fin_enable) {
567 unsigned int map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64;
568
569 if (mpext) {
570 if (opts->csum_reqd)
571 map_size += TCPOLEN_MPTCP_DSS_CHECKSUM;
572
573 opts->ext_copy = *mpext;
574 }
575
576 remaining -= map_size;
577 dss_size = map_size;
578 if (skb && snd_data_fin_enable)
579 mptcp_write_data_fin(subflow, skb, &opts->ext_copy);
580 opts->suboptions = OPTION_MPTCP_DSS;
581 ret = true;
582 }
583
584
585
586
587 opts->ext_copy.use_ack = 0;
588 if (!READ_ONCE(msk->can_ack)) {
589 *size = ALIGN(dss_size, 4);
590 return ret;
591 }
592
593 ack_seq = READ_ONCE(msk->ack_seq);
594 if (READ_ONCE(msk->use_64bit_ack)) {
595 ack_size = TCPOLEN_MPTCP_DSS_ACK64;
596 opts->ext_copy.data_ack = ack_seq;
597 opts->ext_copy.ack64 = 1;
598 } else {
599 ack_size = TCPOLEN_MPTCP_DSS_ACK32;
600 opts->ext_copy.data_ack32 = (uint32_t)ack_seq;
601 opts->ext_copy.ack64 = 0;
602 }
603 opts->ext_copy.use_ack = 1;
604 opts->suboptions = OPTION_MPTCP_DSS;
605 WRITE_ONCE(msk->old_wspace, __mptcp_space((struct sock *)msk));
606
607
608 if (dss_size == 0)
609 ack_size += TCPOLEN_MPTCP_DSS_BASE;
610
611 dss_size += ack_size;
612
613 *size = ALIGN(dss_size, 4);
614 return true;
615}
616
617static u64 add_addr_generate_hmac(u64 key1, u64 key2,
618 struct mptcp_addr_info *addr)
619{
620 u16 port = ntohs(addr->port);
621 u8 hmac[SHA256_DIGEST_SIZE];
622 u8 msg[19];
623 int i = 0;
624
625 msg[i++] = addr->id;
626 if (addr->family == AF_INET) {
627 memcpy(&msg[i], &addr->addr.s_addr, 4);
628 i += 4;
629 }
630#if IS_ENABLED(CONFIG_MPTCP_IPV6)
631 else if (addr->family == AF_INET6) {
632 memcpy(&msg[i], &addr->addr6.s6_addr, 16);
633 i += 16;
634 }
635#endif
636 msg[i++] = port >> 8;
637 msg[i++] = port & 0xFF;
638
639 mptcp_crypto_hmac_sha(key1, key2, msg, i, hmac);
640
641 return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]);
642}
643
644static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *skb,
645 unsigned int *size,
646 unsigned int remaining,
647 struct mptcp_out_options *opts)
648{
649 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
650 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
651 bool drop_other_suboptions = false;
652 unsigned int opt_size = *size;
653 bool echo;
654 bool port;
655 int len;
656
657
658
659
660 if (!mptcp_pm_should_add_signal(msk) ||
661 (opts->suboptions & (OPTION_MPTCP_MPJ_ACK | OPTION_MPTCP_MPC_ACK)) ||
662 !mptcp_pm_add_addr_signal(msk, skb, opt_size, remaining, &opts->addr,
663 &echo, &port, &drop_other_suboptions))
664 return false;
665
666 if (drop_other_suboptions)
667 remaining += opt_size;
668 len = mptcp_add_addr_len(opts->addr.family, echo, port);
669 if (remaining < len)
670 return false;
671
672 *size = len;
673 if (drop_other_suboptions) {
674 pr_debug("drop other suboptions");
675 opts->suboptions = 0;
676
677
678
679
680
681
682 opts->ahmac = 0;
683 *size -= opt_size;
684 }
685 opts->suboptions |= OPTION_MPTCP_ADD_ADDR;
686 if (!echo) {
687 opts->ahmac = add_addr_generate_hmac(msk->local_key,
688 msk->remote_key,
689 &opts->addr);
690 }
691 pr_debug("addr_id=%d, ahmac=%llu, echo=%d, port=%d",
692 opts->addr.id, opts->ahmac, echo, ntohs(opts->addr.port));
693
694 return true;
695}
696
697static bool mptcp_established_options_rm_addr(struct sock *sk,
698 unsigned int *size,
699 unsigned int remaining,
700 struct mptcp_out_options *opts)
701{
702 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
703 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
704 struct mptcp_rm_list rm_list;
705 int i, len;
706
707 if (!mptcp_pm_should_rm_signal(msk) ||
708 !(mptcp_pm_rm_addr_signal(msk, remaining, &rm_list)))
709 return false;
710
711 len = mptcp_rm_addr_len(&rm_list);
712 if (len < 0)
713 return false;
714 if (remaining < len)
715 return false;
716
717 *size = len;
718 opts->suboptions |= OPTION_MPTCP_RM_ADDR;
719 opts->rm_list = rm_list;
720
721 for (i = 0; i < opts->rm_list.nr; i++)
722 pr_debug("rm_list_ids[%d]=%d", i, opts->rm_list.ids[i]);
723
724 return true;
725}
726
727static bool mptcp_established_options_mp_prio(struct sock *sk,
728 unsigned int *size,
729 unsigned int remaining,
730 struct mptcp_out_options *opts)
731{
732 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
733
734
735
736
737 if (!subflow->send_mp_prio || (opts->suboptions & OPTIONS_MPTCP_MPC))
738 return false;
739
740
741 if (remaining < TCPOLEN_MPTCP_PRIO_ALIGN)
742 return false;
743
744 *size = TCPOLEN_MPTCP_PRIO_ALIGN;
745 opts->suboptions |= OPTION_MPTCP_PRIO;
746 opts->backup = subflow->request_bkup;
747
748 pr_debug("prio=%d", opts->backup);
749
750 return true;
751}
752
753static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,
754 unsigned int *size,
755 unsigned int remaining,
756 struct mptcp_out_options *opts)
757{
758 const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
759
760 if (remaining < TCPOLEN_MPTCP_RST)
761 return false;
762
763 *size = TCPOLEN_MPTCP_RST;
764 opts->suboptions |= OPTION_MPTCP_RST;
765 opts->reset_transient = subflow->reset_transient;
766 opts->reset_reason = subflow->reset_reason;
767
768 return true;
769}
770
771static bool mptcp_established_options_mp_fail(struct sock *sk,
772 unsigned int *size,
773 unsigned int remaining,
774 struct mptcp_out_options *opts)
775{
776 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
777
778 if (likely(!subflow->send_mp_fail))
779 return false;
780
781 if (remaining < TCPOLEN_MPTCP_FAIL)
782 return false;
783
784 *size = TCPOLEN_MPTCP_FAIL;
785 opts->suboptions |= OPTION_MPTCP_FAIL;
786 opts->fail_seq = subflow->map_seq;
787
788 pr_debug("MP_FAIL fail_seq=%llu", opts->fail_seq);
789
790 return true;
791}
792
793bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
794 unsigned int *size, unsigned int remaining,
795 struct mptcp_out_options *opts)
796{
797 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
798 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
799 unsigned int opt_size = 0;
800 bool snd_data_fin;
801 bool ret = false;
802
803 opts->suboptions = 0;
804
805 if (unlikely(__mptcp_check_fallback(msk)))
806 return false;
807
808 if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) {
809 if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
810 *size += opt_size;
811 remaining -= opt_size;
812 }
813 if (mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) {
814 *size += opt_size;
815 remaining -= opt_size;
816 }
817 return true;
818 }
819
820 snd_data_fin = mptcp_data_fin_enabled(msk);
821 if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts))
822 ret = true;
823 else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts)) {
824 ret = true;
825 if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
826 *size += opt_size;
827 remaining -= opt_size;
828 return true;
829 }
830 }
831
832
833
834
835 if (WARN_ON_ONCE(opt_size > remaining))
836 return false;
837
838 *size += opt_size;
839 remaining -= opt_size;
840 if (mptcp_established_options_add_addr(sk, skb, &opt_size, remaining, opts)) {
841 *size += opt_size;
842 remaining -= opt_size;
843 ret = true;
844 } else if (mptcp_established_options_rm_addr(sk, &opt_size, remaining, opts)) {
845 *size += opt_size;
846 remaining -= opt_size;
847 ret = true;
848 }
849
850 if (mptcp_established_options_mp_prio(sk, &opt_size, remaining, opts)) {
851 *size += opt_size;
852 remaining -= opt_size;
853 ret = true;
854 }
855
856 return ret;
857}
858
859bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
860 struct mptcp_out_options *opts)
861{
862 struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
863
864 if (subflow_req->mp_capable) {
865 opts->suboptions = OPTION_MPTCP_MPC_SYNACK;
866 opts->sndr_key = subflow_req->local_key;
867 opts->csum_reqd = subflow_req->csum_reqd;
868 opts->allow_join_id0 = subflow_req->allow_join_id0;
869 *size = TCPOLEN_MPTCP_MPC_SYNACK;
870 pr_debug("subflow_req=%p, local_key=%llu",
871 subflow_req, subflow_req->local_key);
872 return true;
873 } else if (subflow_req->mp_join) {
874 opts->suboptions = OPTION_MPTCP_MPJ_SYNACK;
875 opts->backup = subflow_req->backup;
876 opts->join_id = subflow_req->local_id;
877 opts->thmac = subflow_req->thmac;
878 opts->nonce = subflow_req->local_nonce;
879 pr_debug("req=%p, bkup=%u, id=%u, thmac=%llu, nonce=%u",
880 subflow_req, opts->backup, opts->join_id,
881 opts->thmac, opts->nonce);
882 *size = TCPOLEN_MPTCP_MPJ_SYNACK;
883 return true;
884 }
885 return false;
886}
887
888static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
889 struct mptcp_subflow_context *subflow,
890 struct sk_buff *skb,
891 struct mptcp_options_received *mp_opt)
892{
893
894
895
896 if (likely(subflow->fully_established)) {
897
898
899
900
901 if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 &&
902 TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq &&
903 subflow->mp_join && (mp_opt->suboptions & OPTIONS_MPTCP_MPJ) &&
904 READ_ONCE(msk->pm.server_side))
905 tcp_send_ack(ssk);
906 goto fully_established;
907 }
908
909
910
911
912
913
914 if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1) {
915 if (subflow->mp_join)
916 goto reset;
917 return subflow->mp_capable;
918 }
919
920 if (((mp_opt->suboptions & OPTION_MPTCP_DSS) && mp_opt->use_ack) ||
921 ((mp_opt->suboptions & OPTION_MPTCP_ADD_ADDR) && !mp_opt->echo)) {
922
923
924
925 subflow->fully_established = 1;
926 WRITE_ONCE(msk->fully_established, true);
927 goto fully_established;
928 }
929
930
931
932
933
934 if (!(mp_opt->suboptions & OPTIONS_MPTCP_MPC)) {
935 if (subflow->mp_join)
936 goto reset;
937 subflow->mp_capable = 0;
938 pr_fallback(msk);
939 __mptcp_do_fallback(msk);
940 return false;
941 }
942
943 if (mp_opt->deny_join_id0)
944 WRITE_ONCE(msk->pm.remote_deny_join_id0, true);
945
946 if (unlikely(!READ_ONCE(msk->pm.server_side)))
947 pr_warn_once("bogus mpc option on established client sk");
948 mptcp_subflow_fully_established(subflow, mp_opt);
949
950fully_established:
951
952
953
954
955
956 if (likely(subflow->pm_notified) || list_empty(&subflow->node))
957 return true;
958
959 subflow->pm_notified = 1;
960 if (subflow->mp_join) {
961 clear_3rdack_retransmission(ssk);
962 mptcp_pm_subflow_established(msk);
963 } else {
964 mptcp_pm_fully_established(msk, ssk, GFP_ATOMIC);
965 }
966 return true;
967
968reset:
969 mptcp_subflow_reset(ssk);
970 return false;
971}
972
973u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq)
974{
975 u32 old_seq32, cur_seq32;
976
977 old_seq32 = (u32)old_seq;
978 cur_seq32 = (u32)cur_seq;
979 cur_seq = (old_seq & GENMASK_ULL(63, 32)) + cur_seq32;
980 if (unlikely(cur_seq32 < old_seq32 && before(old_seq32, cur_seq32)))
981 return cur_seq + (1LL << 32);
982
983
984 if (unlikely(cur_seq32 > old_seq32 && after(old_seq32, cur_seq32)))
985 return cur_seq - (1LL << 32);
986 return cur_seq;
987}
988
989static void ack_update_msk(struct mptcp_sock *msk,
990 struct sock *ssk,
991 struct mptcp_options_received *mp_opt)
992{
993 u64 new_wnd_end, new_snd_una, snd_nxt = READ_ONCE(msk->snd_nxt);
994 struct sock *sk = (struct sock *)msk;
995 u64 old_snd_una;
996
997 mptcp_data_lock(sk);
998
999
1000
1001
1002
1003 old_snd_una = msk->snd_una;
1004 new_snd_una = mptcp_expand_seq(old_snd_una, mp_opt->data_ack, mp_opt->ack64);
1005
1006
1007 if (unlikely(after64(new_snd_una, snd_nxt)))
1008 new_snd_una = old_snd_una;
1009
1010 new_wnd_end = new_snd_una + tcp_sk(ssk)->snd_wnd;
1011
1012 if (after64(new_wnd_end, msk->wnd_end))
1013 msk->wnd_end = new_wnd_end;
1014
1015
1016 if (after64(msk->wnd_end, READ_ONCE(msk->snd_nxt)))
1017 __mptcp_check_push(sk, ssk);
1018
1019 if (after64(new_snd_una, old_snd_una)) {
1020 msk->snd_una = new_snd_una;
1021 __mptcp_data_acked(sk);
1022 }
1023 mptcp_data_unlock(sk);
1024
1025 trace_ack_update_msk(mp_opt->data_ack,
1026 old_snd_una, new_snd_una,
1027 new_wnd_end, msk->wnd_end);
1028}
1029
1030bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit)
1031{
1032
1033
1034
1035
1036
1037 if (READ_ONCE(msk->rcv_data_fin))
1038 return false;
1039
1040 WRITE_ONCE(msk->rcv_data_fin_seq,
1041 mptcp_expand_seq(READ_ONCE(msk->ack_seq), data_fin_seq, use_64bit));
1042 WRITE_ONCE(msk->rcv_data_fin, 1);
1043
1044 return true;
1045}
1046
1047static bool add_addr_hmac_valid(struct mptcp_sock *msk,
1048 struct mptcp_options_received *mp_opt)
1049{
1050 u64 hmac = 0;
1051
1052 if (mp_opt->echo)
1053 return true;
1054
1055 hmac = add_addr_generate_hmac(msk->remote_key,
1056 msk->local_key,
1057 &mp_opt->addr);
1058
1059 pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n",
1060 msk, (unsigned long long)hmac,
1061 (unsigned long long)mp_opt->ahmac);
1062
1063 return hmac == mp_opt->ahmac;
1064}
1065
1066
1067bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
1068{
1069 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1070 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
1071 struct mptcp_options_received mp_opt;
1072 struct mptcp_ext *mpext;
1073
1074 if (__mptcp_check_fallback(msk)) {
1075
1076
1077
1078
1079
1080 mptcp_data_lock(subflow->conn);
1081 if (sk_stream_memory_free(sk))
1082 __mptcp_check_push(subflow->conn, sk);
1083 __mptcp_data_acked(subflow->conn);
1084 mptcp_data_unlock(subflow->conn);
1085 return true;
1086 }
1087
1088 mptcp_get_options(sk, skb, &mp_opt);
1089
1090
1091
1092
1093 if (!check_fully_established(msk, sk, subflow, skb, &mp_opt))
1094 return sk->sk_state != TCP_CLOSE;
1095
1096 if (unlikely(mp_opt.suboptions != OPTION_MPTCP_DSS)) {
1097 if ((mp_opt.suboptions & OPTION_MPTCP_FASTCLOSE) &&
1098 msk->local_key == mp_opt.rcvr_key) {
1099 WRITE_ONCE(msk->rcv_fastclose, true);
1100 mptcp_schedule_work((struct sock *)msk);
1101 }
1102
1103 if ((mp_opt.suboptions & OPTION_MPTCP_ADD_ADDR) &&
1104 add_addr_hmac_valid(msk, &mp_opt)) {
1105 if (!mp_opt.echo) {
1106 mptcp_pm_add_addr_received(msk, &mp_opt.addr);
1107 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR);
1108 } else {
1109 mptcp_pm_add_addr_echoed(msk, &mp_opt.addr);
1110 mptcp_pm_del_add_timer(msk, &mp_opt.addr, true);
1111 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD);
1112 }
1113
1114 if (mp_opt.addr.port)
1115 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_PORTADD);
1116 }
1117
1118 if (mp_opt.suboptions & OPTION_MPTCP_RM_ADDR)
1119 mptcp_pm_rm_addr_received(msk, &mp_opt.rm_list);
1120
1121 if (mp_opt.suboptions & OPTION_MPTCP_PRIO) {
1122 mptcp_pm_mp_prio_received(sk, mp_opt.backup);
1123 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIORX);
1124 }
1125
1126 if (mp_opt.suboptions & OPTION_MPTCP_FAIL) {
1127 mptcp_pm_mp_fail_received(sk, mp_opt.fail_seq);
1128 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILRX);
1129 }
1130
1131 if (mp_opt.suboptions & OPTION_MPTCP_RST) {
1132 subflow->reset_seen = 1;
1133 subflow->reset_reason = mp_opt.reset_reason;
1134 subflow->reset_transient = mp_opt.reset_transient;
1135 }
1136
1137 if (!(mp_opt.suboptions & OPTION_MPTCP_DSS))
1138 return true;
1139 }
1140
1141
1142
1143
1144 if (mp_opt.use_ack)
1145 ack_update_msk(msk, sk, &mp_opt);
1146
1147
1148
1149
1150
1151
1152 if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) {
1153 if (mp_opt.data_fin && mp_opt.data_len == 1 &&
1154 mptcp_update_rcv_data_fin(msk, mp_opt.data_seq, mp_opt.dsn64) &&
1155 schedule_work(&msk->work))
1156 sock_hold(subflow->conn);
1157
1158 return true;
1159 }
1160
1161 mpext = skb_ext_add(skb, SKB_EXT_MPTCP);
1162 if (!mpext)
1163 return true;
1164
1165 memset(mpext, 0, sizeof(*mpext));
1166
1167 if (likely(mp_opt.use_map)) {
1168 if (mp_opt.mpc_map) {
1169
1170
1171
1172 mptcp_crypto_key_sha(subflow->remote_key, NULL,
1173 &mpext->data_seq);
1174 mpext->data_seq++;
1175 mpext->subflow_seq = 1;
1176 mpext->dsn64 = 1;
1177 mpext->mpc_map = 1;
1178 mpext->data_fin = 0;
1179 } else {
1180 mpext->data_seq = mp_opt.data_seq;
1181 mpext->subflow_seq = mp_opt.subflow_seq;
1182 mpext->dsn64 = mp_opt.dsn64;
1183 mpext->data_fin = mp_opt.data_fin;
1184 }
1185 mpext->data_len = mp_opt.data_len;
1186 mpext->use_map = 1;
1187 mpext->csum_reqd = !!(mp_opt.suboptions & OPTION_MPTCP_CSUMREQD);
1188
1189 if (mpext->csum_reqd)
1190 mpext->csum = mp_opt.csum;
1191 }
1192
1193 return true;
1194}
1195
1196static void mptcp_set_rwin(const struct tcp_sock *tp)
1197{
1198 const struct sock *ssk = (const struct sock *)tp;
1199 const struct mptcp_subflow_context *subflow;
1200 struct mptcp_sock *msk;
1201 u64 ack_seq;
1202
1203 subflow = mptcp_subflow_ctx(ssk);
1204 msk = mptcp_sk(subflow->conn);
1205
1206 ack_seq = READ_ONCE(msk->ack_seq) + tp->rcv_wnd;
1207
1208 if (after64(ack_seq, READ_ONCE(msk->rcv_wnd_sent)))
1209 WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
1210}
1211
1212static u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __sum16 sum)
1213{
1214 struct csum_pseudo_header header;
1215 __wsum csum;
1216
1217
1218
1219
1220
1221
1222 header.data_seq = cpu_to_be64(data_seq);
1223 header.subflow_seq = htonl(subflow_seq);
1224 header.data_len = htons(data_len);
1225 header.csum = 0;
1226
1227 csum = csum_partial(&header, sizeof(header), ~csum_unfold(sum));
1228 return (__force u16)csum_fold(csum);
1229}
1230
1231static u16 mptcp_make_csum(const struct mptcp_ext *mpext)
1232{
1233 return __mptcp_make_csum(mpext->data_seq, mpext->subflow_seq, mpext->data_len,
1234 mpext->csum);
1235}
1236
1237void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
1238 struct mptcp_out_options *opts)
1239{
1240 if (unlikely(OPTION_MPTCP_FAIL & opts->suboptions)) {
1241 const struct sock *ssk = (const struct sock *)tp;
1242 struct mptcp_subflow_context *subflow;
1243
1244 subflow = mptcp_subflow_ctx(ssk);
1245 subflow->send_mp_fail = 0;
1246
1247 *ptr++ = mptcp_option(MPTCPOPT_MP_FAIL,
1248 TCPOLEN_MPTCP_FAIL,
1249 0, 0);
1250 put_unaligned_be64(opts->fail_seq, ptr);
1251 ptr += 2;
1252 }
1253
1254
1255 if (unlikely(OPTION_MPTCP_RST & opts->suboptions)) {
1256 *ptr++ = mptcp_option(MPTCPOPT_RST,
1257 TCPOLEN_MPTCP_RST,
1258 opts->reset_transient,
1259 opts->reset_reason);
1260 return;
1261 }
1262
1263
1264
1265
1266 if (likely(OPTION_MPTCP_DSS & opts->suboptions)) {
1267 struct mptcp_ext *mpext = &opts->ext_copy;
1268 u8 len = TCPOLEN_MPTCP_DSS_BASE;
1269 u8 flags = 0;
1270
1271 if (mpext->use_ack) {
1272 flags = MPTCP_DSS_HAS_ACK;
1273 if (mpext->ack64) {
1274 len += TCPOLEN_MPTCP_DSS_ACK64;
1275 flags |= MPTCP_DSS_ACK64;
1276 } else {
1277 len += TCPOLEN_MPTCP_DSS_ACK32;
1278 }
1279 }
1280
1281 if (mpext->use_map) {
1282 len += TCPOLEN_MPTCP_DSS_MAP64;
1283
1284
1285
1286
1287 flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64;
1288 if (mpext->data_fin)
1289 flags |= MPTCP_DSS_DATA_FIN;
1290
1291 if (opts->csum_reqd)
1292 len += TCPOLEN_MPTCP_DSS_CHECKSUM;
1293 }
1294
1295 *ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags);
1296
1297 if (mpext->use_ack) {
1298 if (mpext->ack64) {
1299 put_unaligned_be64(mpext->data_ack, ptr);
1300 ptr += 2;
1301 } else {
1302 put_unaligned_be32(mpext->data_ack32, ptr);
1303 ptr += 1;
1304 }
1305 }
1306
1307 if (mpext->use_map) {
1308 put_unaligned_be64(mpext->data_seq, ptr);
1309 ptr += 2;
1310 put_unaligned_be32(mpext->subflow_seq, ptr);
1311 ptr += 1;
1312 if (opts->csum_reqd) {
1313 put_unaligned_be32(mpext->data_len << 16 |
1314 mptcp_make_csum(mpext), ptr);
1315 } else {
1316 put_unaligned_be32(mpext->data_len << 16 |
1317 TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
1318 }
1319 }
1320 } else if (OPTIONS_MPTCP_MPC & opts->suboptions) {
1321 u8 len, flag = MPTCP_CAP_HMAC_SHA256;
1322
1323 if (OPTION_MPTCP_MPC_SYN & opts->suboptions) {
1324 len = TCPOLEN_MPTCP_MPC_SYN;
1325 } else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) {
1326 len = TCPOLEN_MPTCP_MPC_SYNACK;
1327 } else if (opts->data_len) {
1328 len = TCPOLEN_MPTCP_MPC_ACK_DATA;
1329 if (opts->csum_reqd)
1330 len += TCPOLEN_MPTCP_DSS_CHECKSUM;
1331 } else {
1332 len = TCPOLEN_MPTCP_MPC_ACK;
1333 }
1334
1335 if (opts->csum_reqd)
1336 flag |= MPTCP_CAP_CHECKSUM_REQD;
1337
1338 if (!opts->allow_join_id0)
1339 flag |= MPTCP_CAP_DENY_JOIN_ID0;
1340
1341 *ptr++ = mptcp_option(MPTCPOPT_MP_CAPABLE, len,
1342 MPTCP_SUPPORTED_VERSION,
1343 flag);
1344
1345 if (!((OPTION_MPTCP_MPC_SYNACK | OPTION_MPTCP_MPC_ACK) &
1346 opts->suboptions))
1347 goto mp_capable_done;
1348
1349 put_unaligned_be64(opts->sndr_key, ptr);
1350 ptr += 2;
1351 if (!((OPTION_MPTCP_MPC_ACK) & opts->suboptions))
1352 goto mp_capable_done;
1353
1354 put_unaligned_be64(opts->rcvr_key, ptr);
1355 ptr += 2;
1356 if (!opts->data_len)
1357 goto mp_capable_done;
1358
1359 if (opts->csum_reqd) {
1360 put_unaligned_be32(opts->data_len << 16 |
1361 __mptcp_make_csum(opts->data_seq,
1362 opts->subflow_seq,
1363 opts->data_len,
1364 opts->csum), ptr);
1365 } else {
1366 put_unaligned_be32(opts->data_len << 16 |
1367 TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
1368 }
1369 ptr += 1;
1370
1371
1372 goto mp_capable_done;
1373 } else if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) {
1374 *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
1375 TCPOLEN_MPTCP_MPJ_SYN,
1376 opts->backup, opts->join_id);
1377 put_unaligned_be32(opts->token, ptr);
1378 ptr += 1;
1379 put_unaligned_be32(opts->nonce, ptr);
1380 ptr += 1;
1381 } else if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) {
1382 *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
1383 TCPOLEN_MPTCP_MPJ_SYNACK,
1384 opts->backup, opts->join_id);
1385 put_unaligned_be64(opts->thmac, ptr);
1386 ptr += 2;
1387 put_unaligned_be32(opts->nonce, ptr);
1388 ptr += 1;
1389 } else if (OPTION_MPTCP_MPJ_ACK & opts->suboptions) {
1390 *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
1391 TCPOLEN_MPTCP_MPJ_ACK, 0, 0);
1392 memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN);
1393 ptr += 5;
1394 } else if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) {
1395 u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
1396 u8 echo = MPTCP_ADDR_ECHO;
1397
1398#if IS_ENABLED(CONFIG_MPTCP_IPV6)
1399 if (opts->addr.family == AF_INET6)
1400 len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
1401#endif
1402
1403 if (opts->addr.port)
1404 len += TCPOLEN_MPTCP_PORT_LEN;
1405
1406 if (opts->ahmac) {
1407 len += sizeof(opts->ahmac);
1408 echo = 0;
1409 }
1410
1411 *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
1412 len, echo, opts->addr.id);
1413 if (opts->addr.family == AF_INET) {
1414 memcpy((u8 *)ptr, (u8 *)&opts->addr.addr.s_addr, 4);
1415 ptr += 1;
1416 }
1417#if IS_ENABLED(CONFIG_MPTCP_IPV6)
1418 else if (opts->addr.family == AF_INET6) {
1419 memcpy((u8 *)ptr, opts->addr.addr6.s6_addr, 16);
1420 ptr += 4;
1421 }
1422#endif
1423
1424 if (!opts->addr.port) {
1425 if (opts->ahmac) {
1426 put_unaligned_be64(opts->ahmac, ptr);
1427 ptr += 2;
1428 }
1429 } else {
1430 u16 port = ntohs(opts->addr.port);
1431
1432 if (opts->ahmac) {
1433 u8 *bptr = (u8 *)ptr;
1434
1435 put_unaligned_be16(port, bptr);
1436 bptr += 2;
1437 put_unaligned_be64(opts->ahmac, bptr);
1438 bptr += 8;
1439 put_unaligned_be16(TCPOPT_NOP << 8 |
1440 TCPOPT_NOP, bptr);
1441
1442 ptr += 3;
1443 } else {
1444 put_unaligned_be32(port << 16 |
1445 TCPOPT_NOP << 8 |
1446 TCPOPT_NOP, ptr);
1447 ptr += 1;
1448 }
1449 }
1450 }
1451
1452 if (OPTION_MPTCP_PRIO & opts->suboptions) {
1453 const struct sock *ssk = (const struct sock *)tp;
1454 struct mptcp_subflow_context *subflow;
1455
1456 subflow = mptcp_subflow_ctx(ssk);
1457 subflow->send_mp_prio = 0;
1458
1459 *ptr++ = mptcp_option(MPTCPOPT_MP_PRIO,
1460 TCPOLEN_MPTCP_PRIO,
1461 opts->backup, TCPOPT_NOP);
1462 }
1463
1464mp_capable_done:
1465 if (OPTION_MPTCP_RM_ADDR & opts->suboptions) {
1466 u8 i = 1;
1467
1468 *ptr++ = mptcp_option(MPTCPOPT_RM_ADDR,
1469 TCPOLEN_MPTCP_RM_ADDR_BASE + opts->rm_list.nr,
1470 0, opts->rm_list.ids[0]);
1471
1472 while (i < opts->rm_list.nr) {
1473 u8 id1, id2, id3, id4;
1474
1475 id1 = opts->rm_list.ids[i];
1476 id2 = i + 1 < opts->rm_list.nr ? opts->rm_list.ids[i + 1] : TCPOPT_NOP;
1477 id3 = i + 2 < opts->rm_list.nr ? opts->rm_list.ids[i + 2] : TCPOPT_NOP;
1478 id4 = i + 3 < opts->rm_list.nr ? opts->rm_list.ids[i + 3] : TCPOPT_NOP;
1479 put_unaligned_be32(id1 << 24 | id2 << 16 | id3 << 8 | id4, ptr);
1480 ptr += 1;
1481 i += 4;
1482 }
1483 }
1484
1485 if (tp)
1486 mptcp_set_rwin(tp);
1487}
1488
1489__be32 mptcp_get_reset_option(const struct sk_buff *skb)
1490{
1491 const struct mptcp_ext *ext = mptcp_get_ext(skb);
1492 u8 flags, reason;
1493
1494 if (ext) {
1495 flags = ext->reset_transient;
1496 reason = ext->reset_reason;
1497
1498 return mptcp_option(MPTCPOPT_RST, TCPOLEN_MPTCP_RST,
1499 flags, reason);
1500 }
1501
1502 return htonl(0u);
1503}
1504EXPORT_SYMBOL_GPL(mptcp_get_reset_option);
1505