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eda7acdd PK |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Multipath TCP | |
3 | * | |
4 | * Copyright (c) 2017 - 2019, Intel Corporation. | |
5 | */ | |
6 | ||
c85adced GT |
7 | #define pr_fmt(fmt) "MPTCP: " fmt |
8 | ||
eda7acdd PK |
9 | #include <linux/kernel.h> |
10 | #include <net/tcp.h> | |
11 | #include <net/mptcp.h> | |
12 | #include "protocol.h" | |
13 | ||
65492c5a PA |
14 | static bool mptcp_cap_flag_sha256(u8 flags) |
15 | { | |
16 | return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256; | |
17 | } | |
18 | ||
cfde141e PA |
19 | static void mptcp_parse_option(const struct sk_buff *skb, |
20 | const unsigned char *ptr, int opsize, | |
21 | struct mptcp_options_received *mp_opt) | |
eda7acdd | 22 | { |
eda7acdd | 23 | u8 subtype = *ptr >> 4; |
648ef4b8 | 24 | int expected_opsize; |
eda7acdd PK |
25 | u8 version; |
26 | u8 flags; | |
27 | ||
28 | switch (subtype) { | |
29 | case MPTCPOPT_MP_CAPABLE: | |
cc7972ea CP |
30 | /* strict size checking */ |
31 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { | |
32 | if (skb->len > tcp_hdr(skb)->doff << 2) | |
33 | expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA; | |
34 | else | |
35 | expected_opsize = TCPOLEN_MPTCP_MPC_ACK; | |
36 | } else { | |
37 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK) | |
38 | expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK; | |
39 | else | |
40 | expected_opsize = TCPOLEN_MPTCP_MPC_SYN; | |
41 | } | |
42 | if (opsize != expected_opsize) | |
eda7acdd PK |
43 | break; |
44 | ||
cc7972ea | 45 | /* try to be gentle vs future versions on the initial syn */ |
eda7acdd | 46 | version = *ptr++ & MPTCP_VERSION_MASK; |
cc7972ea CP |
47 | if (opsize != TCPOLEN_MPTCP_MPC_SYN) { |
48 | if (version != MPTCP_SUPPORTED_VERSION) | |
49 | break; | |
50 | } else if (version < MPTCP_SUPPORTED_VERSION) { | |
eda7acdd | 51 | break; |
cc7972ea | 52 | } |
eda7acdd PK |
53 | |
54 | flags = *ptr++; | |
65492c5a | 55 | if (!mptcp_cap_flag_sha256(flags) || |
eda7acdd PK |
56 | (flags & MPTCP_CAP_EXTENSIBILITY)) |
57 | break; | |
58 | ||
59 | /* RFC 6824, Section 3.1: | |
60 | * "For the Checksum Required bit (labeled "A"), if either | |
61 | * host requires the use of checksums, checksums MUST be used. | |
62 | * In other words, the only way for checksums not to be used | |
63 | * is if both hosts in their SYNs set A=0." | |
64 | * | |
65 | * Section 3.3.0: | |
66 | * "If a checksum is not present when its use has been | |
67 | * negotiated, the receiver MUST close the subflow with a RST as | |
68 | * it is considered broken." | |
69 | * | |
70 | * We don't implement DSS checksum - fall back to TCP. | |
71 | */ | |
72 | if (flags & MPTCP_CAP_CHECKSUM_REQD) | |
73 | break; | |
74 | ||
75 | mp_opt->mp_capable = 1; | |
cc7972ea CP |
76 | if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) { |
77 | mp_opt->sndr_key = get_unaligned_be64(ptr); | |
78 | ptr += 8; | |
79 | } | |
80 | if (opsize >= TCPOLEN_MPTCP_MPC_ACK) { | |
eda7acdd PK |
81 | mp_opt->rcvr_key = get_unaligned_be64(ptr); |
82 | ptr += 8; | |
eda7acdd | 83 | } |
cc7972ea CP |
84 | if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA) { |
85 | /* Section 3.1.: | |
86 | * "the data parameters in a MP_CAPABLE are semantically | |
87 | * equivalent to those in a DSS option and can be used | |
88 | * interchangeably." | |
89 | */ | |
90 | mp_opt->dss = 1; | |
91 | mp_opt->use_map = 1; | |
92 | mp_opt->mpc_map = 1; | |
93 | mp_opt->data_len = get_unaligned_be16(ptr); | |
94 | ptr += 2; | |
95 | } | |
96 | pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d", | |
97 | version, flags, opsize, mp_opt->sndr_key, | |
98 | mp_opt->rcvr_key, mp_opt->data_len); | |
eda7acdd PK |
99 | break; |
100 | ||
f296234c PK |
101 | case MPTCPOPT_MP_JOIN: |
102 | mp_opt->mp_join = 1; | |
103 | if (opsize == TCPOLEN_MPTCP_MPJ_SYN) { | |
104 | mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; | |
105 | mp_opt->join_id = *ptr++; | |
106 | mp_opt->token = get_unaligned_be32(ptr); | |
107 | ptr += 4; | |
108 | mp_opt->nonce = get_unaligned_be32(ptr); | |
109 | ptr += 4; | |
110 | pr_debug("MP_JOIN bkup=%u, id=%u, token=%u, nonce=%u", | |
111 | mp_opt->backup, mp_opt->join_id, | |
112 | mp_opt->token, mp_opt->nonce); | |
113 | } else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) { | |
114 | mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; | |
115 | mp_opt->join_id = *ptr++; | |
116 | mp_opt->thmac = get_unaligned_be64(ptr); | |
117 | ptr += 8; | |
118 | mp_opt->nonce = get_unaligned_be32(ptr); | |
119 | ptr += 4; | |
120 | pr_debug("MP_JOIN bkup=%u, id=%u, thmac=%llu, nonce=%u", | |
121 | mp_opt->backup, mp_opt->join_id, | |
122 | mp_opt->thmac, mp_opt->nonce); | |
123 | } else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) { | |
124 | ptr += 2; | |
125 | memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN); | |
126 | pr_debug("MP_JOIN hmac"); | |
127 | } else { | |
128 | pr_warn("MP_JOIN bad option size"); | |
129 | mp_opt->mp_join = 0; | |
130 | } | |
131 | break; | |
132 | ||
eda7acdd PK |
133 | case MPTCPOPT_DSS: |
134 | pr_debug("DSS"); | |
648ef4b8 MM |
135 | ptr++; |
136 | ||
cc7972ea CP |
137 | /* we must clear 'mpc_map' be able to detect MP_CAPABLE |
138 | * map vs DSS map in mptcp_incoming_options(), and reconstruct | |
139 | * map info accordingly | |
140 | */ | |
141 | mp_opt->mpc_map = 0; | |
648ef4b8 MM |
142 | flags = (*ptr++) & MPTCP_DSS_FLAG_MASK; |
143 | mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0; | |
144 | mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0; | |
145 | mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0; | |
146 | mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0; | |
147 | mp_opt->use_ack = (flags & MPTCP_DSS_HAS_ACK); | |
148 | ||
149 | pr_debug("data_fin=%d dsn64=%d use_map=%d ack64=%d use_ack=%d", | |
150 | mp_opt->data_fin, mp_opt->dsn64, | |
151 | mp_opt->use_map, mp_opt->ack64, | |
152 | mp_opt->use_ack); | |
153 | ||
154 | expected_opsize = TCPOLEN_MPTCP_DSS_BASE; | |
155 | ||
156 | if (mp_opt->use_ack) { | |
157 | if (mp_opt->ack64) | |
158 | expected_opsize += TCPOLEN_MPTCP_DSS_ACK64; | |
159 | else | |
160 | expected_opsize += TCPOLEN_MPTCP_DSS_ACK32; | |
161 | } | |
162 | ||
163 | if (mp_opt->use_map) { | |
164 | if (mp_opt->dsn64) | |
165 | expected_opsize += TCPOLEN_MPTCP_DSS_MAP64; | |
166 | else | |
167 | expected_opsize += TCPOLEN_MPTCP_DSS_MAP32; | |
168 | } | |
169 | ||
170 | /* RFC 6824, Section 3.3: | |
171 | * If a checksum is present, but its use had | |
172 | * not been negotiated in the MP_CAPABLE handshake, | |
173 | * the checksum field MUST be ignored. | |
174 | */ | |
175 | if (opsize != expected_opsize && | |
176 | opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) | |
177 | break; | |
178 | ||
eda7acdd | 179 | mp_opt->dss = 1; |
648ef4b8 MM |
180 | |
181 | if (mp_opt->use_ack) { | |
182 | if (mp_opt->ack64) { | |
183 | mp_opt->data_ack = get_unaligned_be64(ptr); | |
184 | ptr += 8; | |
185 | } else { | |
186 | mp_opt->data_ack = get_unaligned_be32(ptr); | |
187 | ptr += 4; | |
188 | } | |
189 | ||
190 | pr_debug("data_ack=%llu", mp_opt->data_ack); | |
191 | } | |
192 | ||
193 | if (mp_opt->use_map) { | |
194 | if (mp_opt->dsn64) { | |
195 | mp_opt->data_seq = get_unaligned_be64(ptr); | |
196 | ptr += 8; | |
197 | } else { | |
198 | mp_opt->data_seq = get_unaligned_be32(ptr); | |
199 | ptr += 4; | |
200 | } | |
201 | ||
202 | mp_opt->subflow_seq = get_unaligned_be32(ptr); | |
203 | ptr += 4; | |
204 | ||
205 | mp_opt->data_len = get_unaligned_be16(ptr); | |
206 | ptr += 2; | |
207 | ||
208 | pr_debug("data_seq=%llu subflow_seq=%u data_len=%u", | |
209 | mp_opt->data_seq, mp_opt->subflow_seq, | |
210 | mp_opt->data_len); | |
211 | } | |
212 | ||
eda7acdd PK |
213 | break; |
214 | ||
3df523ab PK |
215 | case MPTCPOPT_ADD_ADDR: |
216 | mp_opt->echo = (*ptr++) & MPTCP_ADDR_ECHO; | |
217 | if (!mp_opt->echo) { | |
218 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR || | |
219 | opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT) | |
220 | mp_opt->family = MPTCP_ADDR_IPVERSION_4; | |
221 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
222 | else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6 || | |
223 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT) | |
224 | mp_opt->family = MPTCP_ADDR_IPVERSION_6; | |
225 | #endif | |
226 | else | |
227 | break; | |
228 | } else { | |
229 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE || | |
230 | opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) | |
231 | mp_opt->family = MPTCP_ADDR_IPVERSION_4; | |
232 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
233 | else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE || | |
234 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) | |
235 | mp_opt->family = MPTCP_ADDR_IPVERSION_6; | |
236 | #endif | |
237 | else | |
238 | break; | |
239 | } | |
240 | ||
241 | mp_opt->add_addr = 1; | |
242 | mp_opt->port = 0; | |
243 | mp_opt->addr_id = *ptr++; | |
244 | pr_debug("ADD_ADDR: id=%d", mp_opt->addr_id); | |
245 | if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) { | |
246 | memcpy((u8 *)&mp_opt->addr.s_addr, (u8 *)ptr, 4); | |
247 | ptr += 4; | |
248 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT || | |
249 | opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) { | |
250 | mp_opt->port = get_unaligned_be16(ptr); | |
251 | ptr += 2; | |
252 | } | |
253 | } | |
254 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
255 | else { | |
256 | memcpy(mp_opt->addr6.s6_addr, (u8 *)ptr, 16); | |
257 | ptr += 16; | |
258 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT || | |
259 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) { | |
260 | mp_opt->port = get_unaligned_be16(ptr); | |
261 | ptr += 2; | |
262 | } | |
263 | } | |
264 | #endif | |
265 | if (!mp_opt->echo) { | |
266 | mp_opt->ahmac = get_unaligned_be64(ptr); | |
267 | ptr += 8; | |
268 | } | |
269 | break; | |
270 | ||
271 | case MPTCPOPT_RM_ADDR: | |
272 | if (opsize != TCPOLEN_MPTCP_RM_ADDR_BASE) | |
273 | break; | |
274 | ||
275 | mp_opt->rm_addr = 1; | |
276 | mp_opt->rm_id = *ptr++; | |
277 | pr_debug("RM_ADDR: id=%d", mp_opt->rm_id); | |
278 | break; | |
279 | ||
eda7acdd PK |
280 | default: |
281 | break; | |
282 | } | |
283 | } | |
284 | ||
cec37a6e | 285 | void mptcp_get_options(const struct sk_buff *skb, |
cfde141e | 286 | struct mptcp_options_received *mp_opt) |
cec37a6e | 287 | { |
cec37a6e | 288 | const struct tcphdr *th = tcp_hdr(skb); |
cfde141e PA |
289 | const unsigned char *ptr; |
290 | int length; | |
cec37a6e | 291 | |
cfde141e PA |
292 | /* initialize option status */ |
293 | mp_opt->mp_capable = 0; | |
294 | mp_opt->mp_join = 0; | |
295 | mp_opt->add_addr = 0; | |
296 | mp_opt->rm_addr = 0; | |
297 | mp_opt->dss = 0; | |
298 | ||
299 | length = (th->doff * 4) - sizeof(struct tcphdr); | |
cec37a6e PK |
300 | ptr = (const unsigned char *)(th + 1); |
301 | ||
302 | while (length > 0) { | |
303 | int opcode = *ptr++; | |
304 | int opsize; | |
305 | ||
306 | switch (opcode) { | |
307 | case TCPOPT_EOL: | |
308 | return; | |
309 | case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ | |
310 | length--; | |
311 | continue; | |
312 | default: | |
313 | opsize = *ptr++; | |
314 | if (opsize < 2) /* "silly options" */ | |
315 | return; | |
316 | if (opsize > length) | |
317 | return; /* don't parse partial options */ | |
318 | if (opcode == TCPOPT_MPTCP) | |
cfde141e | 319 | mptcp_parse_option(skb, ptr, opsize, mp_opt); |
cec37a6e PK |
320 | ptr += opsize - 2; |
321 | length -= opsize; | |
322 | } | |
323 | } | |
324 | } | |
325 | ||
cc7972ea CP |
326 | bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, |
327 | unsigned int *size, struct mptcp_out_options *opts) | |
cec37a6e PK |
328 | { |
329 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
330 | ||
cc7972ea CP |
331 | /* we will use snd_isn to detect first pkt [re]transmission |
332 | * in mptcp_established_options_mp() | |
333 | */ | |
334 | subflow->snd_isn = TCP_SKB_CB(skb)->end_seq; | |
cec37a6e PK |
335 | if (subflow->request_mptcp) { |
336 | pr_debug("local_key=%llu", subflow->local_key); | |
337 | opts->suboptions = OPTION_MPTCP_MPC_SYN; | |
338 | opts->sndr_key = subflow->local_key; | |
339 | *size = TCPOLEN_MPTCP_MPC_SYN; | |
340 | return true; | |
ec3edaa7 PK |
341 | } else if (subflow->request_join) { |
342 | pr_debug("remote_token=%u, nonce=%u", subflow->remote_token, | |
343 | subflow->local_nonce); | |
344 | opts->suboptions = OPTION_MPTCP_MPJ_SYN; | |
345 | opts->join_id = subflow->local_id; | |
346 | opts->token = subflow->remote_token; | |
347 | opts->nonce = subflow->local_nonce; | |
348 | opts->backup = subflow->request_bkup; | |
349 | *size = TCPOLEN_MPTCP_MPJ_SYN; | |
350 | return true; | |
cec37a6e PK |
351 | } |
352 | return false; | |
353 | } | |
354 | ||
ec3edaa7 PK |
355 | /* MP_JOIN client subflow must wait for 4th ack before sending any data: |
356 | * TCP can't schedule delack timer before the subflow is fully established. | |
357 | * MPTCP uses the delack timer to do 3rd ack retransmissions | |
358 | */ | |
359 | static void schedule_3rdack_retransmission(struct sock *sk) | |
360 | { | |
361 | struct inet_connection_sock *icsk = inet_csk(sk); | |
362 | struct tcp_sock *tp = tcp_sk(sk); | |
363 | unsigned long timeout; | |
364 | ||
365 | /* reschedule with a timeout above RTT, as we must look only for drop */ | |
366 | if (tp->srtt_us) | |
367 | timeout = tp->srtt_us << 1; | |
368 | else | |
369 | timeout = TCP_TIMEOUT_INIT; | |
370 | ||
371 | WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER); | |
372 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
373 | icsk->icsk_ack.timeout = timeout; | |
374 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
375 | } | |
376 | ||
377 | static void clear_3rdack_retransmission(struct sock *sk) | |
378 | { | |
379 | struct inet_connection_sock *icsk = inet_csk(sk); | |
380 | ||
381 | sk_stop_timer(sk, &icsk->icsk_delack_timer); | |
382 | icsk->icsk_ack.timeout = 0; | |
383 | icsk->icsk_ack.ato = 0; | |
384 | icsk->icsk_ack.pending &= ~(ICSK_ACK_SCHED | ICSK_ACK_TIMER); | |
385 | } | |
386 | ||
cc7972ea CP |
387 | static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, |
388 | unsigned int *size, | |
6d0060f6 MM |
389 | unsigned int remaining, |
390 | struct mptcp_out_options *opts) | |
cec37a6e PK |
391 | { |
392 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cc7972ea CP |
393 | struct mptcp_ext *mpext; |
394 | unsigned int data_len; | |
395 | ||
ec3edaa7 PK |
396 | /* When skb is not available, we better over-estimate the emitted |
397 | * options len. A full DSS option (28 bytes) is longer than | |
398 | * TCPOLEN_MPTCP_MPC_ACK_DATA(22) or TCPOLEN_MPTCP_MPJ_ACK(24), so | |
399 | * tell the caller to defer the estimate to | |
400 | * mptcp_established_options_dss(), which will reserve enough space. | |
401 | */ | |
402 | if (!skb) | |
403 | return false; | |
cc7972ea | 404 | |
ec3edaa7 PK |
405 | /* MPC/MPJ needed only on 3rd ack packet */ |
406 | if (subflow->fully_established || | |
407 | subflow->snd_isn != TCP_SKB_CB(skb)->seq) | |
408 | return false; | |
409 | ||
410 | if (subflow->mp_capable) { | |
cc7972ea CP |
411 | mpext = mptcp_get_ext(skb); |
412 | data_len = mpext ? mpext->data_len : 0; | |
cec37a6e | 413 | |
cc7972ea CP |
414 | /* we will check ext_copy.data_len in mptcp_write_options() to |
415 | * discriminate between TCPOLEN_MPTCP_MPC_ACK_DATA and | |
416 | * TCPOLEN_MPTCP_MPC_ACK | |
417 | */ | |
418 | opts->ext_copy.data_len = data_len; | |
cec37a6e PK |
419 | opts->suboptions = OPTION_MPTCP_MPC_ACK; |
420 | opts->sndr_key = subflow->local_key; | |
421 | opts->rcvr_key = subflow->remote_key; | |
cc7972ea CP |
422 | |
423 | /* Section 3.1. | |
424 | * The MP_CAPABLE option is carried on the SYN, SYN/ACK, and ACK | |
425 | * packets that start the first subflow of an MPTCP connection, | |
426 | * as well as the first packet that carries data | |
427 | */ | |
428 | if (data_len > 0) | |
429 | *size = ALIGN(TCPOLEN_MPTCP_MPC_ACK_DATA, 4); | |
430 | else | |
431 | *size = TCPOLEN_MPTCP_MPC_ACK; | |
432 | ||
433 | pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d", | |
434 | subflow, subflow->local_key, subflow->remote_key, | |
435 | data_len); | |
436 | ||
cec37a6e | 437 | return true; |
ec3edaa7 PK |
438 | } else if (subflow->mp_join) { |
439 | opts->suboptions = OPTION_MPTCP_MPJ_ACK; | |
440 | memcpy(opts->hmac, subflow->hmac, MPTCPOPT_HMAC_LEN); | |
441 | *size = TCPOLEN_MPTCP_MPJ_ACK; | |
442 | pr_debug("subflow=%p", subflow); | |
443 | ||
444 | schedule_3rdack_retransmission(sk); | |
445 | return true; | |
cec37a6e PK |
446 | } |
447 | return false; | |
448 | } | |
449 | ||
6d0060f6 MM |
450 | static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow, |
451 | struct mptcp_ext *ext) | |
452 | { | |
6d0060f6 MM |
453 | if (!ext->use_map) { |
454 | /* RFC6824 requires a DSS mapping with specific values | |
455 | * if DATA_FIN is set but no data payload is mapped | |
456 | */ | |
6d37a0b8 | 457 | ext->data_fin = 1; |
6d0060f6 MM |
458 | ext->use_map = 1; |
459 | ext->dsn64 = 1; | |
76c42a29 | 460 | ext->data_seq = subflow->data_fin_tx_seq; |
6d0060f6 MM |
461 | ext->subflow_seq = 0; |
462 | ext->data_len = 1; | |
6d37a0b8 MM |
463 | } else if (ext->data_seq + ext->data_len == subflow->data_fin_tx_seq) { |
464 | /* If there's an existing DSS mapping and it is the | |
465 | * final mapping, DATA_FIN consumes 1 additional byte of | |
466 | * mapping space. | |
6d0060f6 | 467 | */ |
6d37a0b8 | 468 | ext->data_fin = 1; |
6d0060f6 MM |
469 | ext->data_len++; |
470 | } | |
471 | } | |
472 | ||
473 | static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, | |
474 | unsigned int *size, | |
475 | unsigned int remaining, | |
476 | struct mptcp_out_options *opts) | |
477 | { | |
478 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
479 | unsigned int dss_size = 0; | |
480 | struct mptcp_ext *mpext; | |
481 | struct mptcp_sock *msk; | |
482 | unsigned int ack_size; | |
d22f4988 | 483 | bool ret = false; |
6d0060f6 MM |
484 | u8 tcp_fin; |
485 | ||
486 | if (skb) { | |
487 | mpext = mptcp_get_ext(skb); | |
488 | tcp_fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; | |
489 | } else { | |
490 | mpext = NULL; | |
491 | tcp_fin = 0; | |
492 | } | |
493 | ||
494 | if (!skb || (mpext && mpext->use_map) || tcp_fin) { | |
495 | unsigned int map_size; | |
496 | ||
497 | map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64; | |
498 | ||
499 | remaining -= map_size; | |
500 | dss_size = map_size; | |
501 | if (mpext) | |
502 | opts->ext_copy = *mpext; | |
503 | ||
76c42a29 | 504 | if (skb && tcp_fin && subflow->data_fin_tx_enable) |
6d0060f6 | 505 | mptcp_write_data_fin(subflow, &opts->ext_copy); |
d22f4988 CP |
506 | ret = true; |
507 | } | |
508 | ||
2398e399 PA |
509 | /* passive sockets msk will set the 'can_ack' after accept(), even |
510 | * if the first subflow may have the already the remote key handy | |
511 | */ | |
d22f4988 CP |
512 | opts->ext_copy.use_ack = 0; |
513 | msk = mptcp_sk(subflow->conn); | |
dc093db5 | 514 | if (!READ_ONCE(msk->can_ack)) { |
d22f4988 CP |
515 | *size = ALIGN(dss_size, 4); |
516 | return ret; | |
6d0060f6 MM |
517 | } |
518 | ||
519 | ack_size = TCPOLEN_MPTCP_DSS_ACK64; | |
520 | ||
521 | /* Add kind/length/subtype/flag overhead if mapping is not populated */ | |
522 | if (dss_size == 0) | |
523 | ack_size += TCPOLEN_MPTCP_DSS_BASE; | |
524 | ||
525 | dss_size += ack_size; | |
526 | ||
dc093db5 | 527 | opts->ext_copy.data_ack = msk->ack_seq; |
6d0060f6 MM |
528 | opts->ext_copy.ack64 = 1; |
529 | opts->ext_copy.use_ack = 1; | |
530 | ||
531 | *size = ALIGN(dss_size, 4); | |
532 | return true; | |
533 | } | |
534 | ||
3df523ab PK |
535 | static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, |
536 | struct in_addr *addr) | |
537 | { | |
538 | u8 hmac[MPTCP_ADDR_HMAC_LEN]; | |
539 | u8 msg[7]; | |
540 | ||
541 | msg[0] = addr_id; | |
542 | memcpy(&msg[1], &addr->s_addr, 4); | |
543 | msg[5] = 0; | |
544 | msg[6] = 0; | |
545 | ||
546 | mptcp_crypto_hmac_sha(key1, key2, msg, 7, hmac); | |
547 | ||
548 | return get_unaligned_be64(hmac); | |
549 | } | |
550 | ||
551 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
552 | static u64 add_addr6_generate_hmac(u64 key1, u64 key2, u8 addr_id, | |
553 | struct in6_addr *addr) | |
554 | { | |
555 | u8 hmac[MPTCP_ADDR_HMAC_LEN]; | |
556 | u8 msg[19]; | |
557 | ||
558 | msg[0] = addr_id; | |
559 | memcpy(&msg[1], &addr->s6_addr, 16); | |
560 | msg[17] = 0; | |
561 | msg[18] = 0; | |
562 | ||
563 | mptcp_crypto_hmac_sha(key1, key2, msg, 19, hmac); | |
564 | ||
565 | return get_unaligned_be64(hmac); | |
566 | } | |
567 | #endif | |
568 | ||
569 | static bool mptcp_established_options_addr(struct sock *sk, | |
570 | unsigned int *size, | |
571 | unsigned int remaining, | |
572 | struct mptcp_out_options *opts) | |
573 | { | |
574 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
575 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
1b1c7a0e PK |
576 | struct mptcp_addr_info saddr; |
577 | int len; | |
3df523ab | 578 | |
1b1c7a0e PK |
579 | if (!mptcp_pm_should_signal(msk) || |
580 | !(mptcp_pm_addr_signal(msk, remaining, &saddr))) | |
581 | return false; | |
582 | ||
583 | len = mptcp_add_addr_len(saddr.family); | |
584 | if (remaining < len) | |
585 | return false; | |
3df523ab | 586 | |
1b1c7a0e PK |
587 | *size = len; |
588 | opts->addr_id = saddr.id; | |
589 | if (saddr.family == AF_INET) { | |
3df523ab | 590 | opts->suboptions |= OPTION_MPTCP_ADD_ADDR; |
1b1c7a0e | 591 | opts->addr = saddr.addr; |
3df523ab PK |
592 | opts->ahmac = add_addr_generate_hmac(msk->local_key, |
593 | msk->remote_key, | |
594 | opts->addr_id, | |
595 | &opts->addr); | |
3df523ab PK |
596 | } |
597 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1b1c7a0e | 598 | else if (saddr.family == AF_INET6) { |
3df523ab | 599 | opts->suboptions |= OPTION_MPTCP_ADD_ADDR6; |
1b1c7a0e | 600 | opts->addr6 = saddr.addr6; |
3df523ab PK |
601 | opts->ahmac = add_addr6_generate_hmac(msk->local_key, |
602 | msk->remote_key, | |
603 | opts->addr_id, | |
604 | &opts->addr6); | |
3df523ab PK |
605 | } |
606 | #endif | |
607 | pr_debug("addr_id=%d, ahmac=%llu", opts->addr_id, opts->ahmac); | |
608 | ||
609 | return true; | |
610 | } | |
611 | ||
6d0060f6 MM |
612 | bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, |
613 | unsigned int *size, unsigned int remaining, | |
614 | struct mptcp_out_options *opts) | |
615 | { | |
616 | unsigned int opt_size = 0; | |
617 | bool ret = false; | |
618 | ||
3df523ab PK |
619 | opts->suboptions = 0; |
620 | ||
cc7972ea | 621 | if (mptcp_established_options_mp(sk, skb, &opt_size, remaining, opts)) |
6d0060f6 MM |
622 | ret = true; |
623 | else if (mptcp_established_options_dss(sk, skb, &opt_size, remaining, | |
624 | opts)) | |
625 | ret = true; | |
626 | ||
627 | /* we reserved enough space for the above options, and exceeding the | |
628 | * TCP option space would be fatal | |
629 | */ | |
630 | if (WARN_ON_ONCE(opt_size > remaining)) | |
631 | return false; | |
632 | ||
633 | *size += opt_size; | |
634 | remaining -= opt_size; | |
3df523ab PK |
635 | if (mptcp_established_options_addr(sk, &opt_size, remaining, opts)) { |
636 | *size += opt_size; | |
637 | remaining -= opt_size; | |
638 | ret = true; | |
639 | } | |
6d0060f6 MM |
640 | |
641 | return ret; | |
642 | } | |
643 | ||
cec37a6e PK |
644 | bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, |
645 | struct mptcp_out_options *opts) | |
646 | { | |
647 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
648 | ||
649 | if (subflow_req->mp_capable) { | |
650 | opts->suboptions = OPTION_MPTCP_MPC_SYNACK; | |
651 | opts->sndr_key = subflow_req->local_key; | |
652 | *size = TCPOLEN_MPTCP_MPC_SYNACK; | |
653 | pr_debug("subflow_req=%p, local_key=%llu", | |
654 | subflow_req, subflow_req->local_key); | |
655 | return true; | |
f296234c PK |
656 | } else if (subflow_req->mp_join) { |
657 | opts->suboptions = OPTION_MPTCP_MPJ_SYNACK; | |
658 | opts->backup = subflow_req->backup; | |
659 | opts->join_id = subflow_req->local_id; | |
660 | opts->thmac = subflow_req->thmac; | |
661 | opts->nonce = subflow_req->local_nonce; | |
662 | pr_debug("req=%p, bkup=%u, id=%u, thmac=%llu, nonce=%u", | |
663 | subflow_req, opts->backup, opts->join_id, | |
664 | opts->thmac, opts->nonce); | |
665 | *size = TCPOLEN_MPTCP_MPJ_SYNACK; | |
666 | return true; | |
cec37a6e PK |
667 | } |
668 | return false; | |
669 | } | |
670 | ||
f296234c PK |
671 | static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk, |
672 | struct mptcp_subflow_context *subflow, | |
0be534f5 PA |
673 | struct sk_buff *skb, |
674 | struct mptcp_options_received *mp_opt) | |
d22f4988 CP |
675 | { |
676 | /* here we can process OoO, in-window pkts, only in-sequence 4th ack | |
f296234c | 677 | * will make the subflow fully established |
d22f4988 | 678 | */ |
f296234c PK |
679 | if (likely(subflow->fully_established)) { |
680 | /* on passive sockets, check for 3rd ack retransmission | |
681 | * note that msk is always set by subflow_syn_recv_sock() | |
682 | * for mp_join subflows | |
683 | */ | |
684 | if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 && | |
685 | TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq && | |
686 | subflow->mp_join && mp_opt->mp_join && | |
687 | READ_ONCE(msk->pm.server_side)) | |
688 | tcp_send_ack(sk); | |
689 | goto fully_established; | |
690 | } | |
691 | ||
692 | /* we should process OoO packets before the first subflow is fully | |
693 | * established, but not expected for MP_JOIN subflows | |
694 | */ | |
695 | if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1) | |
696 | return subflow->mp_capable; | |
d22f4988 | 697 | |
5a91e32b | 698 | if (mp_opt->dss && mp_opt->use_ack) { |
f296234c PK |
699 | /* subflows are fully established as soon as we get any |
700 | * additional ack. | |
701 | */ | |
0be534f5 | 702 | subflow->fully_established = 1; |
f296234c PK |
703 | goto fully_established; |
704 | } | |
d22f4988 | 705 | |
d22f4988 CP |
706 | /* If the first established packet does not contain MP_CAPABLE + data |
707 | * then fallback to TCP | |
708 | */ | |
709 | if (!mp_opt->mp_capable) { | |
710 | subflow->mp_capable = 0; | |
f296234c | 711 | tcp_sk(sk)->is_mptcp = 0; |
d22f4988 CP |
712 | return false; |
713 | } | |
f296234c | 714 | |
d6085fe1 PA |
715 | if (unlikely(!READ_ONCE(msk->pm.server_side))) |
716 | pr_warn_once("bogus mpc option on established client sk"); | |
f296234c | 717 | subflow->fully_established = 1; |
d22f4988 CP |
718 | subflow->remote_key = mp_opt->sndr_key; |
719 | subflow->can_ack = 1; | |
f296234c PK |
720 | |
721 | fully_established: | |
722 | if (likely(subflow->pm_notified)) | |
723 | return true; | |
724 | ||
725 | subflow->pm_notified = 1; | |
ec3edaa7 PK |
726 | if (subflow->mp_join) { |
727 | clear_3rdack_retransmission(sk); | |
f296234c | 728 | mptcp_pm_subflow_established(msk, subflow); |
ec3edaa7 | 729 | } else { |
f296234c | 730 | mptcp_pm_fully_established(msk); |
ec3edaa7 | 731 | } |
d22f4988 CP |
732 | return true; |
733 | } | |
734 | ||
cc9d2566 PA |
735 | static u64 expand_ack(u64 old_ack, u64 cur_ack, bool use_64bit) |
736 | { | |
737 | u32 old_ack32, cur_ack32; | |
738 | ||
739 | if (use_64bit) | |
740 | return cur_ack; | |
741 | ||
742 | old_ack32 = (u32)old_ack; | |
743 | cur_ack32 = (u32)cur_ack; | |
744 | cur_ack = (old_ack & GENMASK_ULL(63, 32)) + cur_ack32; | |
745 | if (unlikely(before(cur_ack32, old_ack32))) | |
746 | return cur_ack + (1LL << 32); | |
747 | return cur_ack; | |
748 | } | |
749 | ||
750 | static void update_una(struct mptcp_sock *msk, | |
751 | struct mptcp_options_received *mp_opt) | |
752 | { | |
753 | u64 new_snd_una, snd_una, old_snd_una = atomic64_read(&msk->snd_una); | |
754 | u64 write_seq = READ_ONCE(msk->write_seq); | |
755 | ||
756 | /* avoid ack expansion on update conflict, to reduce the risk of | |
757 | * wrongly expanding to a future ack sequence number, which is way | |
758 | * more dangerous than missing an ack | |
759 | */ | |
760 | new_snd_una = expand_ack(old_snd_una, mp_opt->data_ack, mp_opt->ack64); | |
761 | ||
762 | /* ACK for data not even sent yet? Ignore. */ | |
763 | if (after64(new_snd_una, write_seq)) | |
764 | new_snd_una = old_snd_una; | |
765 | ||
766 | while (after64(new_snd_una, old_snd_una)) { | |
767 | snd_una = old_snd_una; | |
768 | old_snd_una = atomic64_cmpxchg(&msk->snd_una, snd_una, | |
769 | new_snd_una); | |
b51f9b80 PA |
770 | if (old_snd_una == snd_una) { |
771 | mptcp_data_acked((struct sock *)msk); | |
cc9d2566 | 772 | break; |
b51f9b80 | 773 | } |
cc9d2566 PA |
774 | } |
775 | } | |
776 | ||
1b1c7a0e PK |
777 | static bool add_addr_hmac_valid(struct mptcp_sock *msk, |
778 | struct mptcp_options_received *mp_opt) | |
779 | { | |
780 | u64 hmac = 0; | |
781 | ||
782 | if (mp_opt->echo) | |
783 | return true; | |
784 | ||
785 | if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) | |
786 | hmac = add_addr_generate_hmac(msk->remote_key, | |
787 | msk->local_key, | |
788 | mp_opt->addr_id, &mp_opt->addr); | |
789 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
790 | else | |
791 | hmac = add_addr6_generate_hmac(msk->remote_key, | |
792 | msk->local_key, | |
793 | mp_opt->addr_id, &mp_opt->addr6); | |
794 | #endif | |
795 | ||
796 | pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n", | |
797 | msk, (unsigned long long)hmac, | |
798 | (unsigned long long)mp_opt->ahmac); | |
799 | ||
800 | return hmac == mp_opt->ahmac; | |
801 | } | |
802 | ||
648ef4b8 MM |
803 | void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, |
804 | struct tcp_options_received *opt_rx) | |
805 | { | |
d22f4988 | 806 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1b1c7a0e | 807 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
cfde141e | 808 | struct mptcp_options_received mp_opt; |
648ef4b8 MM |
809 | struct mptcp_ext *mpext; |
810 | ||
cfde141e PA |
811 | mptcp_get_options(skb, &mp_opt); |
812 | if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) | |
d22f4988 | 813 | return; |
648ef4b8 | 814 | |
cfde141e | 815 | if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) { |
1b1c7a0e PK |
816 | struct mptcp_addr_info addr; |
817 | ||
cfde141e PA |
818 | addr.port = htons(mp_opt.port); |
819 | addr.id = mp_opt.addr_id; | |
820 | if (mp_opt.family == MPTCP_ADDR_IPVERSION_4) { | |
1b1c7a0e | 821 | addr.family = AF_INET; |
cfde141e | 822 | addr.addr = mp_opt.addr; |
1b1c7a0e PK |
823 | } |
824 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
cfde141e | 825 | else if (mp_opt.family == MPTCP_ADDR_IPVERSION_6) { |
1b1c7a0e | 826 | addr.family = AF_INET6; |
cfde141e | 827 | addr.addr6 = mp_opt.addr6; |
1b1c7a0e PK |
828 | } |
829 | #endif | |
cfde141e | 830 | if (!mp_opt.echo) |
1b1c7a0e | 831 | mptcp_pm_add_addr_received(msk, &addr); |
cfde141e | 832 | mp_opt.add_addr = 0; |
1b1c7a0e PK |
833 | } |
834 | ||
cfde141e | 835 | if (!mp_opt.dss) |
648ef4b8 MM |
836 | return; |
837 | ||
cc9d2566 PA |
838 | /* we can't wait for recvmsg() to update the ack_seq, otherwise |
839 | * monodirectional flows will stuck | |
840 | */ | |
cfde141e PA |
841 | if (mp_opt.use_ack) |
842 | update_una(msk, &mp_opt); | |
cc9d2566 | 843 | |
648ef4b8 MM |
844 | mpext = skb_ext_add(skb, SKB_EXT_MPTCP); |
845 | if (!mpext) | |
846 | return; | |
847 | ||
848 | memset(mpext, 0, sizeof(*mpext)); | |
849 | ||
cfde141e PA |
850 | if (mp_opt.use_map) { |
851 | if (mp_opt.mpc_map) { | |
cc7972ea CP |
852 | /* this is an MP_CAPABLE carrying MPTCP data |
853 | * we know this map the first chunk of data | |
854 | */ | |
855 | mptcp_crypto_key_sha(subflow->remote_key, NULL, | |
856 | &mpext->data_seq); | |
857 | mpext->data_seq++; | |
858 | mpext->subflow_seq = 1; | |
859 | mpext->dsn64 = 1; | |
860 | mpext->mpc_map = 1; | |
a77895db | 861 | mpext->data_fin = 0; |
cc7972ea | 862 | } else { |
cfde141e PA |
863 | mpext->data_seq = mp_opt.data_seq; |
864 | mpext->subflow_seq = mp_opt.subflow_seq; | |
865 | mpext->dsn64 = mp_opt.dsn64; | |
866 | mpext->data_fin = mp_opt.data_fin; | |
cc7972ea | 867 | } |
cfde141e | 868 | mpext->data_len = mp_opt.data_len; |
648ef4b8 | 869 | mpext->use_map = 1; |
648ef4b8 | 870 | } |
648ef4b8 MM |
871 | } |
872 | ||
eda7acdd PK |
873 | void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts) |
874 | { | |
cc7972ea | 875 | if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | |
eda7acdd PK |
876 | OPTION_MPTCP_MPC_ACK) & opts->suboptions) { |
877 | u8 len; | |
878 | ||
879 | if (OPTION_MPTCP_MPC_SYN & opts->suboptions) | |
880 | len = TCPOLEN_MPTCP_MPC_SYN; | |
cec37a6e PK |
881 | else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) |
882 | len = TCPOLEN_MPTCP_MPC_SYNACK; | |
cc7972ea CP |
883 | else if (opts->ext_copy.data_len) |
884 | len = TCPOLEN_MPTCP_MPC_ACK_DATA; | |
eda7acdd PK |
885 | else |
886 | len = TCPOLEN_MPTCP_MPC_ACK; | |
887 | ||
3df523ab PK |
888 | *ptr++ = mptcp_option(MPTCPOPT_MP_CAPABLE, len, |
889 | MPTCP_SUPPORTED_VERSION, | |
890 | MPTCP_CAP_HMAC_SHA256); | |
cc7972ea CP |
891 | |
892 | if (!((OPTION_MPTCP_MPC_SYNACK | OPTION_MPTCP_MPC_ACK) & | |
893 | opts->suboptions)) | |
894 | goto mp_capable_done; | |
895 | ||
eda7acdd PK |
896 | put_unaligned_be64(opts->sndr_key, ptr); |
897 | ptr += 2; | |
cc7972ea CP |
898 | if (!((OPTION_MPTCP_MPC_ACK) & opts->suboptions)) |
899 | goto mp_capable_done; | |
900 | ||
901 | put_unaligned_be64(opts->rcvr_key, ptr); | |
902 | ptr += 2; | |
903 | if (!opts->ext_copy.data_len) | |
904 | goto mp_capable_done; | |
905 | ||
906 | put_unaligned_be32(opts->ext_copy.data_len << 16 | | |
907 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); | |
908 | ptr += 1; | |
eda7acdd | 909 | } |
6d0060f6 | 910 | |
cc7972ea | 911 | mp_capable_done: |
3df523ab PK |
912 | if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) { |
913 | if (opts->ahmac) | |
914 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
915 | TCPOLEN_MPTCP_ADD_ADDR, 0, | |
916 | opts->addr_id); | |
917 | else | |
918 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
919 | TCPOLEN_MPTCP_ADD_ADDR_BASE, | |
920 | MPTCP_ADDR_ECHO, | |
921 | opts->addr_id); | |
922 | memcpy((u8 *)ptr, (u8 *)&opts->addr.s_addr, 4); | |
923 | ptr += 1; | |
924 | if (opts->ahmac) { | |
925 | put_unaligned_be64(opts->ahmac, ptr); | |
926 | ptr += 2; | |
927 | } | |
928 | } | |
929 | ||
930 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
931 | if (OPTION_MPTCP_ADD_ADDR6 & opts->suboptions) { | |
932 | if (opts->ahmac) | |
933 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
934 | TCPOLEN_MPTCP_ADD_ADDR6, 0, | |
935 | opts->addr_id); | |
936 | else | |
937 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
938 | TCPOLEN_MPTCP_ADD_ADDR6_BASE, | |
939 | MPTCP_ADDR_ECHO, | |
940 | opts->addr_id); | |
941 | memcpy((u8 *)ptr, opts->addr6.s6_addr, 16); | |
942 | ptr += 4; | |
943 | if (opts->ahmac) { | |
944 | put_unaligned_be64(opts->ahmac, ptr); | |
945 | ptr += 2; | |
946 | } | |
947 | } | |
948 | #endif | |
949 | ||
950 | if (OPTION_MPTCP_RM_ADDR & opts->suboptions) { | |
951 | *ptr++ = mptcp_option(MPTCPOPT_RM_ADDR, | |
952 | TCPOLEN_MPTCP_RM_ADDR_BASE, | |
953 | 0, opts->rm_id); | |
954 | } | |
955 | ||
ec3edaa7 PK |
956 | if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) { |
957 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
958 | TCPOLEN_MPTCP_MPJ_SYN, | |
959 | opts->backup, opts->join_id); | |
960 | put_unaligned_be32(opts->token, ptr); | |
961 | ptr += 1; | |
962 | put_unaligned_be32(opts->nonce, ptr); | |
963 | ptr += 1; | |
964 | } | |
965 | ||
f296234c PK |
966 | if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) { |
967 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
968 | TCPOLEN_MPTCP_MPJ_SYNACK, | |
969 | opts->backup, opts->join_id); | |
970 | put_unaligned_be64(opts->thmac, ptr); | |
971 | ptr += 2; | |
972 | put_unaligned_be32(opts->nonce, ptr); | |
973 | ptr += 1; | |
974 | } | |
975 | ||
ec3edaa7 PK |
976 | if (OPTION_MPTCP_MPJ_ACK & opts->suboptions) { |
977 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
978 | TCPOLEN_MPTCP_MPJ_ACK, 0, 0); | |
979 | memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN); | |
980 | ptr += 5; | |
981 | } | |
982 | ||
6d0060f6 MM |
983 | if (opts->ext_copy.use_ack || opts->ext_copy.use_map) { |
984 | struct mptcp_ext *mpext = &opts->ext_copy; | |
985 | u8 len = TCPOLEN_MPTCP_DSS_BASE; | |
986 | u8 flags = 0; | |
987 | ||
988 | if (mpext->use_ack) { | |
989 | len += TCPOLEN_MPTCP_DSS_ACK64; | |
990 | flags = MPTCP_DSS_HAS_ACK | MPTCP_DSS_ACK64; | |
991 | } | |
992 | ||
993 | if (mpext->use_map) { | |
994 | len += TCPOLEN_MPTCP_DSS_MAP64; | |
995 | ||
996 | /* Use only 64-bit mapping flags for now, add | |
997 | * support for optional 32-bit mappings later. | |
998 | */ | |
999 | flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64; | |
1000 | if (mpext->data_fin) | |
1001 | flags |= MPTCP_DSS_DATA_FIN; | |
1002 | } | |
1003 | ||
3df523ab | 1004 | *ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags); |
6d0060f6 MM |
1005 | |
1006 | if (mpext->use_ack) { | |
1007 | put_unaligned_be64(mpext->data_ack, ptr); | |
1008 | ptr += 2; | |
1009 | } | |
1010 | ||
1011 | if (mpext->use_map) { | |
1012 | put_unaligned_be64(mpext->data_seq, ptr); | |
1013 | ptr += 2; | |
1014 | put_unaligned_be32(mpext->subflow_seq, ptr); | |
1015 | ptr += 1; | |
1016 | put_unaligned_be32(mpext->data_len << 16 | | |
1017 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); | |
1018 | } | |
1019 | } | |
eda7acdd | 1020 | } |