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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 | 9 | #include <linux/kernel.h> |
bd697222 | 10 | #include <crypto/sha.h> |
eda7acdd PK |
11 | #include <net/tcp.h> |
12 | #include <net/mptcp.h> | |
13 | #include "protocol.h" | |
14 | ||
65492c5a PA |
15 | static bool mptcp_cap_flag_sha256(u8 flags) |
16 | { | |
17 | return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256; | |
18 | } | |
19 | ||
cfde141e PA |
20 | static void mptcp_parse_option(const struct sk_buff *skb, |
21 | const unsigned char *ptr, int opsize, | |
22 | struct mptcp_options_received *mp_opt) | |
eda7acdd | 23 | { |
eda7acdd | 24 | u8 subtype = *ptr >> 4; |
648ef4b8 | 25 | int expected_opsize; |
eda7acdd PK |
26 | u8 version; |
27 | u8 flags; | |
28 | ||
29 | switch (subtype) { | |
30 | case MPTCPOPT_MP_CAPABLE: | |
cc7972ea CP |
31 | /* strict size checking */ |
32 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { | |
33 | if (skb->len > tcp_hdr(skb)->doff << 2) | |
34 | expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA; | |
35 | else | |
36 | expected_opsize = TCPOLEN_MPTCP_MPC_ACK; | |
37 | } else { | |
38 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK) | |
39 | expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK; | |
40 | else | |
41 | expected_opsize = TCPOLEN_MPTCP_MPC_SYN; | |
42 | } | |
43 | if (opsize != expected_opsize) | |
eda7acdd PK |
44 | break; |
45 | ||
cc7972ea | 46 | /* try to be gentle vs future versions on the initial syn */ |
eda7acdd | 47 | version = *ptr++ & MPTCP_VERSION_MASK; |
cc7972ea CP |
48 | if (opsize != TCPOLEN_MPTCP_MPC_SYN) { |
49 | if (version != MPTCP_SUPPORTED_VERSION) | |
50 | break; | |
51 | } else if (version < MPTCP_SUPPORTED_VERSION) { | |
eda7acdd | 52 | break; |
cc7972ea | 53 | } |
eda7acdd PK |
54 | |
55 | flags = *ptr++; | |
65492c5a | 56 | if (!mptcp_cap_flag_sha256(flags) || |
eda7acdd PK |
57 | (flags & MPTCP_CAP_EXTENSIBILITY)) |
58 | break; | |
59 | ||
60 | /* RFC 6824, Section 3.1: | |
61 | * "For the Checksum Required bit (labeled "A"), if either | |
62 | * host requires the use of checksums, checksums MUST be used. | |
63 | * In other words, the only way for checksums not to be used | |
64 | * is if both hosts in their SYNs set A=0." | |
65 | * | |
66 | * Section 3.3.0: | |
67 | * "If a checksum is not present when its use has been | |
68 | * negotiated, the receiver MUST close the subflow with a RST as | |
69 | * it is considered broken." | |
70 | * | |
71 | * We don't implement DSS checksum - fall back to TCP. | |
72 | */ | |
73 | if (flags & MPTCP_CAP_CHECKSUM_REQD) | |
74 | break; | |
75 | ||
76 | mp_opt->mp_capable = 1; | |
cc7972ea CP |
77 | if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) { |
78 | mp_opt->sndr_key = get_unaligned_be64(ptr); | |
79 | ptr += 8; | |
80 | } | |
81 | if (opsize >= TCPOLEN_MPTCP_MPC_ACK) { | |
eda7acdd PK |
82 | mp_opt->rcvr_key = get_unaligned_be64(ptr); |
83 | ptr += 8; | |
eda7acdd | 84 | } |
cc7972ea CP |
85 | if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA) { |
86 | /* Section 3.1.: | |
87 | * "the data parameters in a MP_CAPABLE are semantically | |
88 | * equivalent to those in a DSS option and can be used | |
89 | * interchangeably." | |
90 | */ | |
91 | mp_opt->dss = 1; | |
92 | mp_opt->use_map = 1; | |
93 | mp_opt->mpc_map = 1; | |
94 | mp_opt->data_len = get_unaligned_be16(ptr); | |
95 | ptr += 2; | |
96 | } | |
97 | pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d", | |
98 | version, flags, opsize, mp_opt->sndr_key, | |
99 | mp_opt->rcvr_key, mp_opt->data_len); | |
eda7acdd PK |
100 | break; |
101 | ||
f296234c PK |
102 | case MPTCPOPT_MP_JOIN: |
103 | mp_opt->mp_join = 1; | |
104 | if (opsize == TCPOLEN_MPTCP_MPJ_SYN) { | |
105 | mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; | |
106 | mp_opt->join_id = *ptr++; | |
107 | mp_opt->token = get_unaligned_be32(ptr); | |
108 | ptr += 4; | |
109 | mp_opt->nonce = get_unaligned_be32(ptr); | |
110 | ptr += 4; | |
111 | pr_debug("MP_JOIN bkup=%u, id=%u, token=%u, nonce=%u", | |
112 | mp_opt->backup, mp_opt->join_id, | |
113 | mp_opt->token, mp_opt->nonce); | |
114 | } else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) { | |
115 | mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; | |
116 | mp_opt->join_id = *ptr++; | |
117 | mp_opt->thmac = get_unaligned_be64(ptr); | |
118 | ptr += 8; | |
119 | mp_opt->nonce = get_unaligned_be32(ptr); | |
120 | ptr += 4; | |
121 | pr_debug("MP_JOIN bkup=%u, id=%u, thmac=%llu, nonce=%u", | |
122 | mp_opt->backup, mp_opt->join_id, | |
123 | mp_opt->thmac, mp_opt->nonce); | |
124 | } else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) { | |
125 | ptr += 2; | |
126 | memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN); | |
127 | pr_debug("MP_JOIN hmac"); | |
128 | } else { | |
129 | pr_warn("MP_JOIN bad option size"); | |
130 | mp_opt->mp_join = 0; | |
131 | } | |
132 | break; | |
133 | ||
eda7acdd PK |
134 | case MPTCPOPT_DSS: |
135 | pr_debug("DSS"); | |
648ef4b8 MM |
136 | ptr++; |
137 | ||
cc7972ea CP |
138 | /* we must clear 'mpc_map' be able to detect MP_CAPABLE |
139 | * map vs DSS map in mptcp_incoming_options(), and reconstruct | |
140 | * map info accordingly | |
141 | */ | |
142 | mp_opt->mpc_map = 0; | |
648ef4b8 MM |
143 | flags = (*ptr++) & MPTCP_DSS_FLAG_MASK; |
144 | mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0; | |
145 | mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0; | |
146 | mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0; | |
147 | mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0; | |
148 | mp_opt->use_ack = (flags & MPTCP_DSS_HAS_ACK); | |
149 | ||
150 | pr_debug("data_fin=%d dsn64=%d use_map=%d ack64=%d use_ack=%d", | |
151 | mp_opt->data_fin, mp_opt->dsn64, | |
152 | mp_opt->use_map, mp_opt->ack64, | |
153 | mp_opt->use_ack); | |
154 | ||
155 | expected_opsize = TCPOLEN_MPTCP_DSS_BASE; | |
156 | ||
157 | if (mp_opt->use_ack) { | |
158 | if (mp_opt->ack64) | |
159 | expected_opsize += TCPOLEN_MPTCP_DSS_ACK64; | |
160 | else | |
161 | expected_opsize += TCPOLEN_MPTCP_DSS_ACK32; | |
162 | } | |
163 | ||
164 | if (mp_opt->use_map) { | |
165 | if (mp_opt->dsn64) | |
166 | expected_opsize += TCPOLEN_MPTCP_DSS_MAP64; | |
167 | else | |
168 | expected_opsize += TCPOLEN_MPTCP_DSS_MAP32; | |
169 | } | |
170 | ||
171 | /* RFC 6824, Section 3.3: | |
172 | * If a checksum is present, but its use had | |
173 | * not been negotiated in the MP_CAPABLE handshake, | |
174 | * the checksum field MUST be ignored. | |
175 | */ | |
176 | if (opsize != expected_opsize && | |
177 | opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) | |
178 | break; | |
179 | ||
eda7acdd | 180 | mp_opt->dss = 1; |
648ef4b8 MM |
181 | |
182 | if (mp_opt->use_ack) { | |
183 | if (mp_opt->ack64) { | |
184 | mp_opt->data_ack = get_unaligned_be64(ptr); | |
185 | ptr += 8; | |
186 | } else { | |
187 | mp_opt->data_ack = get_unaligned_be32(ptr); | |
188 | ptr += 4; | |
189 | } | |
190 | ||
191 | pr_debug("data_ack=%llu", mp_opt->data_ack); | |
192 | } | |
193 | ||
194 | if (mp_opt->use_map) { | |
195 | if (mp_opt->dsn64) { | |
196 | mp_opt->data_seq = get_unaligned_be64(ptr); | |
197 | ptr += 8; | |
198 | } else { | |
199 | mp_opt->data_seq = get_unaligned_be32(ptr); | |
200 | ptr += 4; | |
201 | } | |
202 | ||
203 | mp_opt->subflow_seq = get_unaligned_be32(ptr); | |
204 | ptr += 4; | |
205 | ||
206 | mp_opt->data_len = get_unaligned_be16(ptr); | |
207 | ptr += 2; | |
208 | ||
209 | pr_debug("data_seq=%llu subflow_seq=%u data_len=%u", | |
210 | mp_opt->data_seq, mp_opt->subflow_seq, | |
211 | mp_opt->data_len); | |
212 | } | |
213 | ||
eda7acdd PK |
214 | break; |
215 | ||
3df523ab PK |
216 | case MPTCPOPT_ADD_ADDR: |
217 | mp_opt->echo = (*ptr++) & MPTCP_ADDR_ECHO; | |
218 | if (!mp_opt->echo) { | |
219 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR || | |
220 | opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT) | |
221 | mp_opt->family = MPTCP_ADDR_IPVERSION_4; | |
222 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
223 | else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6 || | |
224 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT) | |
225 | mp_opt->family = MPTCP_ADDR_IPVERSION_6; | |
226 | #endif | |
227 | else | |
228 | break; | |
229 | } else { | |
230 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE || | |
231 | opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) | |
232 | mp_opt->family = MPTCP_ADDR_IPVERSION_4; | |
233 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
234 | else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE || | |
235 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) | |
236 | mp_opt->family = MPTCP_ADDR_IPVERSION_6; | |
237 | #endif | |
238 | else | |
239 | break; | |
240 | } | |
241 | ||
242 | mp_opt->add_addr = 1; | |
243 | mp_opt->port = 0; | |
244 | mp_opt->addr_id = *ptr++; | |
6a6c05a8 | 245 | pr_debug("ADD_ADDR: id=%d, echo=%d", mp_opt->addr_id, mp_opt->echo); |
3df523ab PK |
246 | if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) { |
247 | memcpy((u8 *)&mp_opt->addr.s_addr, (u8 *)ptr, 4); | |
248 | ptr += 4; | |
249 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT || | |
250 | opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) { | |
251 | mp_opt->port = get_unaligned_be16(ptr); | |
252 | ptr += 2; | |
253 | } | |
254 | } | |
255 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
256 | else { | |
257 | memcpy(mp_opt->addr6.s6_addr, (u8 *)ptr, 16); | |
258 | ptr += 16; | |
259 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT || | |
260 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) { | |
261 | mp_opt->port = get_unaligned_be16(ptr); | |
262 | ptr += 2; | |
263 | } | |
264 | } | |
265 | #endif | |
266 | if (!mp_opt->echo) { | |
267 | mp_opt->ahmac = get_unaligned_be64(ptr); | |
268 | ptr += 8; | |
269 | } | |
270 | break; | |
271 | ||
272 | case MPTCPOPT_RM_ADDR: | |
273 | if (opsize != TCPOLEN_MPTCP_RM_ADDR_BASE) | |
274 | break; | |
275 | ||
8e60eed6 GT |
276 | ptr++; |
277 | ||
3df523ab PK |
278 | mp_opt->rm_addr = 1; |
279 | mp_opt->rm_id = *ptr++; | |
280 | pr_debug("RM_ADDR: id=%d", mp_opt->rm_id); | |
281 | break; | |
282 | ||
eda7acdd PK |
283 | default: |
284 | break; | |
285 | } | |
286 | } | |
287 | ||
cec37a6e | 288 | void mptcp_get_options(const struct sk_buff *skb, |
cfde141e | 289 | struct mptcp_options_received *mp_opt) |
cec37a6e | 290 | { |
cec37a6e | 291 | const struct tcphdr *th = tcp_hdr(skb); |
cfde141e PA |
292 | const unsigned char *ptr; |
293 | int length; | |
cec37a6e | 294 | |
cfde141e PA |
295 | /* initialize option status */ |
296 | mp_opt->mp_capable = 0; | |
297 | mp_opt->mp_join = 0; | |
298 | mp_opt->add_addr = 0; | |
299 | mp_opt->rm_addr = 0; | |
300 | mp_opt->dss = 0; | |
301 | ||
302 | length = (th->doff * 4) - sizeof(struct tcphdr); | |
cec37a6e PK |
303 | ptr = (const unsigned char *)(th + 1); |
304 | ||
305 | while (length > 0) { | |
306 | int opcode = *ptr++; | |
307 | int opsize; | |
308 | ||
309 | switch (opcode) { | |
310 | case TCPOPT_EOL: | |
311 | return; | |
312 | case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ | |
313 | length--; | |
314 | continue; | |
315 | default: | |
316 | opsize = *ptr++; | |
317 | if (opsize < 2) /* "silly options" */ | |
318 | return; | |
319 | if (opsize > length) | |
320 | return; /* don't parse partial options */ | |
321 | if (opcode == TCPOPT_MPTCP) | |
cfde141e | 322 | mptcp_parse_option(skb, ptr, opsize, mp_opt); |
cec37a6e PK |
323 | ptr += opsize - 2; |
324 | length -= opsize; | |
325 | } | |
326 | } | |
327 | } | |
328 | ||
cc7972ea CP |
329 | bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, |
330 | unsigned int *size, struct mptcp_out_options *opts) | |
cec37a6e PK |
331 | { |
332 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
333 | ||
cc7972ea CP |
334 | /* we will use snd_isn to detect first pkt [re]transmission |
335 | * in mptcp_established_options_mp() | |
336 | */ | |
337 | subflow->snd_isn = TCP_SKB_CB(skb)->end_seq; | |
cec37a6e | 338 | if (subflow->request_mptcp) { |
cec37a6e | 339 | opts->suboptions = OPTION_MPTCP_MPC_SYN; |
cec37a6e PK |
340 | *size = TCPOLEN_MPTCP_MPC_SYN; |
341 | return true; | |
ec3edaa7 PK |
342 | } else if (subflow->request_join) { |
343 | pr_debug("remote_token=%u, nonce=%u", subflow->remote_token, | |
344 | subflow->local_nonce); | |
345 | opts->suboptions = OPTION_MPTCP_MPJ_SYN; | |
346 | opts->join_id = subflow->local_id; | |
347 | opts->token = subflow->remote_token; | |
348 | opts->nonce = subflow->local_nonce; | |
349 | opts->backup = subflow->request_bkup; | |
350 | *size = TCPOLEN_MPTCP_MPJ_SYN; | |
351 | return true; | |
cec37a6e PK |
352 | } |
353 | return false; | |
354 | } | |
355 | ||
ec3edaa7 PK |
356 | /* MP_JOIN client subflow must wait for 4th ack before sending any data: |
357 | * TCP can't schedule delack timer before the subflow is fully established. | |
358 | * MPTCP uses the delack timer to do 3rd ack retransmissions | |
359 | */ | |
360 | static void schedule_3rdack_retransmission(struct sock *sk) | |
361 | { | |
362 | struct inet_connection_sock *icsk = inet_csk(sk); | |
363 | struct tcp_sock *tp = tcp_sk(sk); | |
364 | unsigned long timeout; | |
365 | ||
366 | /* reschedule with a timeout above RTT, as we must look only for drop */ | |
367 | if (tp->srtt_us) | |
368 | timeout = tp->srtt_us << 1; | |
369 | else | |
370 | timeout = TCP_TIMEOUT_INIT; | |
371 | ||
372 | WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER); | |
373 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
374 | icsk->icsk_ack.timeout = timeout; | |
375 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
376 | } | |
377 | ||
378 | static void clear_3rdack_retransmission(struct sock *sk) | |
379 | { | |
380 | struct inet_connection_sock *icsk = inet_csk(sk); | |
381 | ||
382 | sk_stop_timer(sk, &icsk->icsk_delack_timer); | |
383 | icsk->icsk_ack.timeout = 0; | |
384 | icsk->icsk_ack.ato = 0; | |
385 | icsk->icsk_ack.pending &= ~(ICSK_ACK_SCHED | ICSK_ACK_TIMER); | |
386 | } | |
387 | ||
cc7972ea CP |
388 | static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, |
389 | unsigned int *size, | |
6d0060f6 MM |
390 | unsigned int remaining, |
391 | struct mptcp_out_options *opts) | |
cec37a6e PK |
392 | { |
393 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cc7972ea CP |
394 | struct mptcp_ext *mpext; |
395 | unsigned int data_len; | |
396 | ||
ec3edaa7 PK |
397 | /* When skb is not available, we better over-estimate the emitted |
398 | * options len. A full DSS option (28 bytes) is longer than | |
399 | * TCPOLEN_MPTCP_MPC_ACK_DATA(22) or TCPOLEN_MPTCP_MPJ_ACK(24), so | |
400 | * tell the caller to defer the estimate to | |
401 | * mptcp_established_options_dss(), which will reserve enough space. | |
402 | */ | |
403 | if (!skb) | |
404 | return false; | |
cc7972ea | 405 | |
ec3edaa7 PK |
406 | /* MPC/MPJ needed only on 3rd ack packet */ |
407 | if (subflow->fully_established || | |
408 | subflow->snd_isn != TCP_SKB_CB(skb)->seq) | |
409 | return false; | |
410 | ||
411 | if (subflow->mp_capable) { | |
cc7972ea CP |
412 | mpext = mptcp_get_ext(skb); |
413 | data_len = mpext ? mpext->data_len : 0; | |
cec37a6e | 414 | |
cc7972ea CP |
415 | /* we will check ext_copy.data_len in mptcp_write_options() to |
416 | * discriminate between TCPOLEN_MPTCP_MPC_ACK_DATA and | |
417 | * TCPOLEN_MPTCP_MPC_ACK | |
418 | */ | |
419 | opts->ext_copy.data_len = data_len; | |
cec37a6e PK |
420 | opts->suboptions = OPTION_MPTCP_MPC_ACK; |
421 | opts->sndr_key = subflow->local_key; | |
422 | opts->rcvr_key = subflow->remote_key; | |
cc7972ea CP |
423 | |
424 | /* Section 3.1. | |
425 | * The MP_CAPABLE option is carried on the SYN, SYN/ACK, and ACK | |
426 | * packets that start the first subflow of an MPTCP connection, | |
427 | * as well as the first packet that carries data | |
428 | */ | |
429 | if (data_len > 0) | |
430 | *size = ALIGN(TCPOLEN_MPTCP_MPC_ACK_DATA, 4); | |
431 | else | |
432 | *size = TCPOLEN_MPTCP_MPC_ACK; | |
433 | ||
434 | pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d", | |
435 | subflow, subflow->local_key, subflow->remote_key, | |
436 | data_len); | |
437 | ||
cec37a6e | 438 | return true; |
ec3edaa7 PK |
439 | } else if (subflow->mp_join) { |
440 | opts->suboptions = OPTION_MPTCP_MPJ_ACK; | |
441 | memcpy(opts->hmac, subflow->hmac, MPTCPOPT_HMAC_LEN); | |
442 | *size = TCPOLEN_MPTCP_MPJ_ACK; | |
443 | pr_debug("subflow=%p", subflow); | |
444 | ||
445 | schedule_3rdack_retransmission(sk); | |
446 | return true; | |
cec37a6e PK |
447 | } |
448 | return false; | |
449 | } | |
450 | ||
6d0060f6 | 451 | static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow, |
9c29e361 | 452 | struct sk_buff *skb, struct mptcp_ext *ext) |
6d0060f6 | 453 | { |
7279da61 MM |
454 | u64 data_fin_tx_seq = READ_ONCE(mptcp_sk(subflow->conn)->write_seq); |
455 | ||
9c29e361 | 456 | if (!ext->use_map || !skb->len) { |
6d0060f6 MM |
457 | /* RFC6824 requires a DSS mapping with specific values |
458 | * if DATA_FIN is set but no data payload is mapped | |
459 | */ | |
6d37a0b8 | 460 | ext->data_fin = 1; |
6d0060f6 MM |
461 | ext->use_map = 1; |
462 | ext->dsn64 = 1; | |
7279da61 MM |
463 | /* The write_seq value has already been incremented, so |
464 | * the actual sequence number for the DATA_FIN is one less. | |
465 | */ | |
466 | ext->data_seq = data_fin_tx_seq - 1; | |
6d0060f6 MM |
467 | ext->subflow_seq = 0; |
468 | ext->data_len = 1; | |
7279da61 | 469 | } else if (ext->data_seq + ext->data_len == data_fin_tx_seq) { |
6d37a0b8 MM |
470 | /* If there's an existing DSS mapping and it is the |
471 | * final mapping, DATA_FIN consumes 1 additional byte of | |
472 | * mapping space. | |
6d0060f6 | 473 | */ |
6d37a0b8 | 474 | ext->data_fin = 1; |
6d0060f6 MM |
475 | ext->data_len++; |
476 | } | |
477 | } | |
478 | ||
479 | static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, | |
480 | unsigned int *size, | |
481 | unsigned int remaining, | |
482 | struct mptcp_out_options *opts) | |
483 | { | |
484 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
7279da61 | 485 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
6d0060f6 | 486 | unsigned int dss_size = 0; |
7279da61 | 487 | u64 snd_data_fin_enable; |
6d0060f6 | 488 | struct mptcp_ext *mpext; |
6d0060f6 | 489 | unsigned int ack_size; |
d22f4988 | 490 | bool ret = false; |
6d0060f6 | 491 | |
0bac966a | 492 | mpext = skb ? mptcp_get_ext(skb) : NULL; |
7279da61 | 493 | snd_data_fin_enable = READ_ONCE(msk->snd_data_fin_enable); |
6d0060f6 | 494 | |
7279da61 | 495 | if (!skb || (mpext && mpext->use_map) || snd_data_fin_enable) { |
6d0060f6 MM |
496 | unsigned int map_size; |
497 | ||
498 | map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64; | |
499 | ||
500 | remaining -= map_size; | |
501 | dss_size = map_size; | |
502 | if (mpext) | |
503 | opts->ext_copy = *mpext; | |
504 | ||
7279da61 | 505 | if (skb && snd_data_fin_enable) |
9c29e361 | 506 | mptcp_write_data_fin(subflow, skb, &opts->ext_copy); |
d22f4988 CP |
507 | ret = true; |
508 | } | |
509 | ||
2398e399 PA |
510 | /* passive sockets msk will set the 'can_ack' after accept(), even |
511 | * if the first subflow may have the already the remote key handy | |
512 | */ | |
d22f4988 | 513 | opts->ext_copy.use_ack = 0; |
dc093db5 | 514 | if (!READ_ONCE(msk->can_ack)) { |
d22f4988 CP |
515 | *size = ALIGN(dss_size, 4); |
516 | return ret; | |
6d0060f6 MM |
517 | } |
518 | ||
a0c1d0ea CP |
519 | if (subflow->use_64bit_ack) { |
520 | ack_size = TCPOLEN_MPTCP_DSS_ACK64; | |
521 | opts->ext_copy.data_ack = msk->ack_seq; | |
522 | opts->ext_copy.ack64 = 1; | |
523 | } else { | |
524 | ack_size = TCPOLEN_MPTCP_DSS_ACK32; | |
525 | opts->ext_copy.data_ack32 = (uint32_t)(msk->ack_seq); | |
526 | opts->ext_copy.ack64 = 0; | |
527 | } | |
528 | opts->ext_copy.use_ack = 1; | |
6d0060f6 MM |
529 | |
530 | /* Add kind/length/subtype/flag overhead if mapping is not populated */ | |
531 | if (dss_size == 0) | |
532 | ack_size += TCPOLEN_MPTCP_DSS_BASE; | |
533 | ||
534 | dss_size += ack_size; | |
535 | ||
6d0060f6 MM |
536 | *size = ALIGN(dss_size, 4); |
537 | return true; | |
538 | } | |
539 | ||
3df523ab PK |
540 | static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, |
541 | struct in_addr *addr) | |
542 | { | |
bd697222 | 543 | u8 hmac[SHA256_DIGEST_SIZE]; |
3df523ab PK |
544 | u8 msg[7]; |
545 | ||
546 | msg[0] = addr_id; | |
547 | memcpy(&msg[1], &addr->s_addr, 4); | |
548 | msg[5] = 0; | |
549 | msg[6] = 0; | |
550 | ||
551 | mptcp_crypto_hmac_sha(key1, key2, msg, 7, hmac); | |
552 | ||
bd697222 | 553 | return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); |
3df523ab PK |
554 | } |
555 | ||
556 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
557 | static u64 add_addr6_generate_hmac(u64 key1, u64 key2, u8 addr_id, | |
558 | struct in6_addr *addr) | |
559 | { | |
bd697222 | 560 | u8 hmac[SHA256_DIGEST_SIZE]; |
3df523ab PK |
561 | u8 msg[19]; |
562 | ||
563 | msg[0] = addr_id; | |
564 | memcpy(&msg[1], &addr->s6_addr, 16); | |
565 | msg[17] = 0; | |
566 | msg[18] = 0; | |
567 | ||
568 | mptcp_crypto_hmac_sha(key1, key2, msg, 19, hmac); | |
569 | ||
bd697222 | 570 | return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); |
3df523ab PK |
571 | } |
572 | #endif | |
573 | ||
f643b803 GT |
574 | static bool mptcp_established_options_add_addr(struct sock *sk, |
575 | unsigned int *size, | |
576 | unsigned int remaining, | |
577 | struct mptcp_out_options *opts) | |
3df523ab PK |
578 | { |
579 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
580 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
1b1c7a0e | 581 | struct mptcp_addr_info saddr; |
6a6c05a8 | 582 | bool echo; |
1b1c7a0e | 583 | int len; |
3df523ab | 584 | |
f643b803 | 585 | if (!mptcp_pm_should_add_signal(msk) || |
6a6c05a8 | 586 | !(mptcp_pm_add_addr_signal(msk, remaining, &saddr, &echo))) |
1b1c7a0e PK |
587 | return false; |
588 | ||
589 | len = mptcp_add_addr_len(saddr.family); | |
590 | if (remaining < len) | |
591 | return false; | |
3df523ab | 592 | |
1b1c7a0e PK |
593 | *size = len; |
594 | opts->addr_id = saddr.id; | |
595 | if (saddr.family == AF_INET) { | |
3df523ab | 596 | opts->suboptions |= OPTION_MPTCP_ADD_ADDR; |
1b1c7a0e | 597 | opts->addr = saddr.addr; |
6a6c05a8 GT |
598 | if (!echo) { |
599 | opts->ahmac = add_addr_generate_hmac(msk->local_key, | |
600 | msk->remote_key, | |
601 | opts->addr_id, | |
602 | &opts->addr); | |
603 | } | |
3df523ab PK |
604 | } |
605 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1b1c7a0e | 606 | else if (saddr.family == AF_INET6) { |
3df523ab | 607 | opts->suboptions |= OPTION_MPTCP_ADD_ADDR6; |
1b1c7a0e | 608 | opts->addr6 = saddr.addr6; |
6a6c05a8 GT |
609 | if (!echo) { |
610 | opts->ahmac = add_addr6_generate_hmac(msk->local_key, | |
611 | msk->remote_key, | |
612 | opts->addr_id, | |
613 | &opts->addr6); | |
614 | } | |
3df523ab PK |
615 | } |
616 | #endif | |
6a6c05a8 | 617 | pr_debug("addr_id=%d, ahmac=%llu, echo=%d", opts->addr_id, opts->ahmac, echo); |
3df523ab PK |
618 | |
619 | return true; | |
620 | } | |
621 | ||
5cb104ae GT |
622 | static bool mptcp_established_options_rm_addr(struct sock *sk, |
623 | unsigned int *size, | |
624 | unsigned int remaining, | |
625 | struct mptcp_out_options *opts) | |
626 | { | |
627 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
628 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
629 | u8 rm_id; | |
630 | ||
631 | if (!mptcp_pm_should_rm_signal(msk) || | |
632 | !(mptcp_pm_rm_addr_signal(msk, remaining, &rm_id))) | |
633 | return false; | |
634 | ||
635 | if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE) | |
636 | return false; | |
637 | ||
638 | *size = TCPOLEN_MPTCP_RM_ADDR_BASE; | |
639 | opts->suboptions |= OPTION_MPTCP_RM_ADDR; | |
640 | opts->rm_id = rm_id; | |
641 | ||
642 | pr_debug("rm_id=%d", opts->rm_id); | |
643 | ||
644 | return true; | |
645 | } | |
646 | ||
6d0060f6 MM |
647 | bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, |
648 | unsigned int *size, unsigned int remaining, | |
649 | struct mptcp_out_options *opts) | |
650 | { | |
651 | unsigned int opt_size = 0; | |
652 | bool ret = false; | |
653 | ||
3df523ab PK |
654 | opts->suboptions = 0; |
655 | ||
e1ff9e82 DC |
656 | if (unlikely(mptcp_check_fallback(sk))) |
657 | return false; | |
658 | ||
cc7972ea | 659 | if (mptcp_established_options_mp(sk, skb, &opt_size, remaining, opts)) |
6d0060f6 MM |
660 | ret = true; |
661 | else if (mptcp_established_options_dss(sk, skb, &opt_size, remaining, | |
662 | opts)) | |
663 | ret = true; | |
664 | ||
665 | /* we reserved enough space for the above options, and exceeding the | |
666 | * TCP option space would be fatal | |
667 | */ | |
668 | if (WARN_ON_ONCE(opt_size > remaining)) | |
669 | return false; | |
670 | ||
671 | *size += opt_size; | |
672 | remaining -= opt_size; | |
f643b803 | 673 | if (mptcp_established_options_add_addr(sk, &opt_size, remaining, opts)) { |
3df523ab PK |
674 | *size += opt_size; |
675 | remaining -= opt_size; | |
676 | ret = true; | |
5cb104ae GT |
677 | } else if (mptcp_established_options_rm_addr(sk, &opt_size, remaining, opts)) { |
678 | *size += opt_size; | |
679 | remaining -= opt_size; | |
680 | ret = true; | |
3df523ab | 681 | } |
6d0060f6 MM |
682 | |
683 | return ret; | |
684 | } | |
685 | ||
cec37a6e PK |
686 | bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, |
687 | struct mptcp_out_options *opts) | |
688 | { | |
689 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
690 | ||
691 | if (subflow_req->mp_capable) { | |
692 | opts->suboptions = OPTION_MPTCP_MPC_SYNACK; | |
693 | opts->sndr_key = subflow_req->local_key; | |
694 | *size = TCPOLEN_MPTCP_MPC_SYNACK; | |
695 | pr_debug("subflow_req=%p, local_key=%llu", | |
696 | subflow_req, subflow_req->local_key); | |
697 | return true; | |
f296234c PK |
698 | } else if (subflow_req->mp_join) { |
699 | opts->suboptions = OPTION_MPTCP_MPJ_SYNACK; | |
700 | opts->backup = subflow_req->backup; | |
701 | opts->join_id = subflow_req->local_id; | |
702 | opts->thmac = subflow_req->thmac; | |
703 | opts->nonce = subflow_req->local_nonce; | |
704 | pr_debug("req=%p, bkup=%u, id=%u, thmac=%llu, nonce=%u", | |
705 | subflow_req, opts->backup, opts->join_id, | |
706 | opts->thmac, opts->nonce); | |
707 | *size = TCPOLEN_MPTCP_MPJ_SYNACK; | |
708 | return true; | |
cec37a6e PK |
709 | } |
710 | return false; | |
711 | } | |
712 | ||
f296234c PK |
713 | static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk, |
714 | struct mptcp_subflow_context *subflow, | |
0be534f5 PA |
715 | struct sk_buff *skb, |
716 | struct mptcp_options_received *mp_opt) | |
d22f4988 CP |
717 | { |
718 | /* here we can process OoO, in-window pkts, only in-sequence 4th ack | |
f296234c | 719 | * will make the subflow fully established |
d22f4988 | 720 | */ |
f296234c PK |
721 | if (likely(subflow->fully_established)) { |
722 | /* on passive sockets, check for 3rd ack retransmission | |
723 | * note that msk is always set by subflow_syn_recv_sock() | |
724 | * for mp_join subflows | |
725 | */ | |
726 | if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 && | |
727 | TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq && | |
728 | subflow->mp_join && mp_opt->mp_join && | |
729 | READ_ONCE(msk->pm.server_side)) | |
730 | tcp_send_ack(sk); | |
731 | goto fully_established; | |
732 | } | |
733 | ||
734 | /* we should process OoO packets before the first subflow is fully | |
735 | * established, but not expected for MP_JOIN subflows | |
736 | */ | |
737 | if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1) | |
738 | return subflow->mp_capable; | |
d22f4988 | 739 | |
5a91e32b | 740 | if (mp_opt->dss && mp_opt->use_ack) { |
f296234c PK |
741 | /* subflows are fully established as soon as we get any |
742 | * additional ack. | |
743 | */ | |
0be534f5 | 744 | subflow->fully_established = 1; |
b93df08c | 745 | WRITE_ONCE(msk->fully_established, true); |
f296234c PK |
746 | goto fully_established; |
747 | } | |
d22f4988 | 748 | |
d22f4988 CP |
749 | /* If the first established packet does not contain MP_CAPABLE + data |
750 | * then fallback to TCP | |
751 | */ | |
752 | if (!mp_opt->mp_capable) { | |
753 | subflow->mp_capable = 0; | |
e1ff9e82 DC |
754 | pr_fallback(msk); |
755 | __mptcp_do_fallback(msk); | |
d22f4988 CP |
756 | return false; |
757 | } | |
f296234c | 758 | |
d6085fe1 PA |
759 | if (unlikely(!READ_ONCE(msk->pm.server_side))) |
760 | pr_warn_once("bogus mpc option on established client sk"); | |
b93df08c | 761 | mptcp_subflow_fully_established(subflow, mp_opt); |
f296234c PK |
762 | |
763 | fully_established: | |
764 | if (likely(subflow->pm_notified)) | |
765 | return true; | |
766 | ||
767 | subflow->pm_notified = 1; | |
ec3edaa7 PK |
768 | if (subflow->mp_join) { |
769 | clear_3rdack_retransmission(sk); | |
f296234c | 770 | mptcp_pm_subflow_established(msk, subflow); |
ec3edaa7 | 771 | } else { |
f296234c | 772 | mptcp_pm_fully_established(msk); |
ec3edaa7 | 773 | } |
d22f4988 CP |
774 | return true; |
775 | } | |
776 | ||
cc9d2566 PA |
777 | static u64 expand_ack(u64 old_ack, u64 cur_ack, bool use_64bit) |
778 | { | |
779 | u32 old_ack32, cur_ack32; | |
780 | ||
781 | if (use_64bit) | |
782 | return cur_ack; | |
783 | ||
784 | old_ack32 = (u32)old_ack; | |
785 | cur_ack32 = (u32)cur_ack; | |
786 | cur_ack = (old_ack & GENMASK_ULL(63, 32)) + cur_ack32; | |
787 | if (unlikely(before(cur_ack32, old_ack32))) | |
788 | return cur_ack + (1LL << 32); | |
789 | return cur_ack; | |
790 | } | |
791 | ||
792 | static void update_una(struct mptcp_sock *msk, | |
793 | struct mptcp_options_received *mp_opt) | |
794 | { | |
795 | u64 new_snd_una, snd_una, old_snd_una = atomic64_read(&msk->snd_una); | |
796 | u64 write_seq = READ_ONCE(msk->write_seq); | |
797 | ||
798 | /* avoid ack expansion on update conflict, to reduce the risk of | |
799 | * wrongly expanding to a future ack sequence number, which is way | |
800 | * more dangerous than missing an ack | |
801 | */ | |
802 | new_snd_una = expand_ack(old_snd_una, mp_opt->data_ack, mp_opt->ack64); | |
803 | ||
804 | /* ACK for data not even sent yet? Ignore. */ | |
805 | if (after64(new_snd_una, write_seq)) | |
806 | new_snd_una = old_snd_una; | |
807 | ||
808 | while (after64(new_snd_una, old_snd_una)) { | |
809 | snd_una = old_snd_una; | |
810 | old_snd_una = atomic64_cmpxchg(&msk->snd_una, snd_una, | |
811 | new_snd_una); | |
b51f9b80 PA |
812 | if (old_snd_una == snd_una) { |
813 | mptcp_data_acked((struct sock *)msk); | |
cc9d2566 | 814 | break; |
b51f9b80 | 815 | } |
cc9d2566 PA |
816 | } |
817 | } | |
818 | ||
3721b9b6 MM |
819 | bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq) |
820 | { | |
821 | /* Skip if DATA_FIN was already received. | |
822 | * If updating simultaneously with the recvmsg loop, values | |
823 | * should match. If they mismatch, the peer is misbehaving and | |
824 | * we will prefer the most recent information. | |
825 | */ | |
826 | if (READ_ONCE(msk->rcv_data_fin) || !READ_ONCE(msk->first)) | |
827 | return false; | |
828 | ||
829 | WRITE_ONCE(msk->rcv_data_fin_seq, data_fin_seq); | |
830 | WRITE_ONCE(msk->rcv_data_fin, 1); | |
831 | ||
832 | return true; | |
833 | } | |
834 | ||
1b1c7a0e PK |
835 | static bool add_addr_hmac_valid(struct mptcp_sock *msk, |
836 | struct mptcp_options_received *mp_opt) | |
837 | { | |
838 | u64 hmac = 0; | |
839 | ||
840 | if (mp_opt->echo) | |
841 | return true; | |
842 | ||
843 | if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) | |
844 | hmac = add_addr_generate_hmac(msk->remote_key, | |
845 | msk->local_key, | |
846 | mp_opt->addr_id, &mp_opt->addr); | |
847 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
848 | else | |
849 | hmac = add_addr6_generate_hmac(msk->remote_key, | |
850 | msk->local_key, | |
851 | mp_opt->addr_id, &mp_opt->addr6); | |
852 | #endif | |
853 | ||
854 | pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n", | |
855 | msk, (unsigned long long)hmac, | |
856 | (unsigned long long)mp_opt->ahmac); | |
857 | ||
858 | return hmac == mp_opt->ahmac; | |
859 | } | |
860 | ||
648ef4b8 MM |
861 | void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, |
862 | struct tcp_options_received *opt_rx) | |
863 | { | |
d22f4988 | 864 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1b1c7a0e | 865 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
cfde141e | 866 | struct mptcp_options_received mp_opt; |
648ef4b8 MM |
867 | struct mptcp_ext *mpext; |
868 | ||
e1ff9e82 DC |
869 | if (__mptcp_check_fallback(msk)) |
870 | return; | |
871 | ||
cfde141e PA |
872 | mptcp_get_options(skb, &mp_opt); |
873 | if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) | |
d22f4988 | 874 | return; |
648ef4b8 | 875 | |
cfde141e | 876 | if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) { |
1b1c7a0e PK |
877 | struct mptcp_addr_info addr; |
878 | ||
cfde141e PA |
879 | addr.port = htons(mp_opt.port); |
880 | addr.id = mp_opt.addr_id; | |
881 | if (mp_opt.family == MPTCP_ADDR_IPVERSION_4) { | |
1b1c7a0e | 882 | addr.family = AF_INET; |
cfde141e | 883 | addr.addr = mp_opt.addr; |
1b1c7a0e PK |
884 | } |
885 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
cfde141e | 886 | else if (mp_opt.family == MPTCP_ADDR_IPVERSION_6) { |
1b1c7a0e | 887 | addr.family = AF_INET6; |
cfde141e | 888 | addr.addr6 = mp_opt.addr6; |
1b1c7a0e PK |
889 | } |
890 | #endif | |
cfde141e | 891 | if (!mp_opt.echo) |
1b1c7a0e | 892 | mptcp_pm_add_addr_received(msk, &addr); |
cfde141e | 893 | mp_opt.add_addr = 0; |
1b1c7a0e PK |
894 | } |
895 | ||
d0876b22 GT |
896 | if (mp_opt.rm_addr) { |
897 | mptcp_pm_rm_addr_received(msk, mp_opt.rm_id); | |
898 | mp_opt.rm_addr = 0; | |
899 | } | |
900 | ||
cfde141e | 901 | if (!mp_opt.dss) |
648ef4b8 MM |
902 | return; |
903 | ||
cc9d2566 PA |
904 | /* we can't wait for recvmsg() to update the ack_seq, otherwise |
905 | * monodirectional flows will stuck | |
906 | */ | |
cfde141e PA |
907 | if (mp_opt.use_ack) |
908 | update_una(msk, &mp_opt); | |
cc9d2566 | 909 | |
06827b34 MM |
910 | /* Zero-data-length packets are dropped by the caller and not |
911 | * propagated to the MPTCP layer, so the skb extension does not | |
912 | * need to be allocated or populated. DATA_FIN information, if | |
913 | * present, needs to be updated here before the skb is freed. | |
43b54c6e MM |
914 | */ |
915 | if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { | |
916 | if (mp_opt.data_fin && mp_opt.data_len == 1 && | |
917 | mptcp_update_rcv_data_fin(msk, mp_opt.data_seq) && | |
918 | schedule_work(&msk->work)) | |
919 | sock_hold(subflow->conn); | |
06827b34 MM |
920 | |
921 | return; | |
43b54c6e MM |
922 | } |
923 | ||
648ef4b8 MM |
924 | mpext = skb_ext_add(skb, SKB_EXT_MPTCP); |
925 | if (!mpext) | |
926 | return; | |
927 | ||
928 | memset(mpext, 0, sizeof(*mpext)); | |
929 | ||
cfde141e PA |
930 | if (mp_opt.use_map) { |
931 | if (mp_opt.mpc_map) { | |
cc7972ea CP |
932 | /* this is an MP_CAPABLE carrying MPTCP data |
933 | * we know this map the first chunk of data | |
934 | */ | |
935 | mptcp_crypto_key_sha(subflow->remote_key, NULL, | |
936 | &mpext->data_seq); | |
937 | mpext->data_seq++; | |
938 | mpext->subflow_seq = 1; | |
939 | mpext->dsn64 = 1; | |
940 | mpext->mpc_map = 1; | |
a77895db | 941 | mpext->data_fin = 0; |
cc7972ea | 942 | } else { |
cfde141e PA |
943 | mpext->data_seq = mp_opt.data_seq; |
944 | mpext->subflow_seq = mp_opt.subflow_seq; | |
945 | mpext->dsn64 = mp_opt.dsn64; | |
946 | mpext->data_fin = mp_opt.data_fin; | |
cc7972ea | 947 | } |
cfde141e | 948 | mpext->data_len = mp_opt.data_len; |
648ef4b8 | 949 | mpext->use_map = 1; |
648ef4b8 | 950 | } |
648ef4b8 MM |
951 | } |
952 | ||
eda7acdd PK |
953 | void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts) |
954 | { | |
cc7972ea | 955 | if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | |
eda7acdd PK |
956 | OPTION_MPTCP_MPC_ACK) & opts->suboptions) { |
957 | u8 len; | |
958 | ||
959 | if (OPTION_MPTCP_MPC_SYN & opts->suboptions) | |
960 | len = TCPOLEN_MPTCP_MPC_SYN; | |
cec37a6e PK |
961 | else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) |
962 | len = TCPOLEN_MPTCP_MPC_SYNACK; | |
cc7972ea CP |
963 | else if (opts->ext_copy.data_len) |
964 | len = TCPOLEN_MPTCP_MPC_ACK_DATA; | |
eda7acdd PK |
965 | else |
966 | len = TCPOLEN_MPTCP_MPC_ACK; | |
967 | ||
3df523ab PK |
968 | *ptr++ = mptcp_option(MPTCPOPT_MP_CAPABLE, len, |
969 | MPTCP_SUPPORTED_VERSION, | |
970 | MPTCP_CAP_HMAC_SHA256); | |
cc7972ea CP |
971 | |
972 | if (!((OPTION_MPTCP_MPC_SYNACK | OPTION_MPTCP_MPC_ACK) & | |
973 | opts->suboptions)) | |
974 | goto mp_capable_done; | |
975 | ||
eda7acdd PK |
976 | put_unaligned_be64(opts->sndr_key, ptr); |
977 | ptr += 2; | |
cc7972ea CP |
978 | if (!((OPTION_MPTCP_MPC_ACK) & opts->suboptions)) |
979 | goto mp_capable_done; | |
980 | ||
981 | put_unaligned_be64(opts->rcvr_key, ptr); | |
982 | ptr += 2; | |
983 | if (!opts->ext_copy.data_len) | |
984 | goto mp_capable_done; | |
985 | ||
986 | put_unaligned_be32(opts->ext_copy.data_len << 16 | | |
987 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); | |
988 | ptr += 1; | |
eda7acdd | 989 | } |
6d0060f6 | 990 | |
cc7972ea | 991 | mp_capable_done: |
3df523ab PK |
992 | if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) { |
993 | if (opts->ahmac) | |
994 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
995 | TCPOLEN_MPTCP_ADD_ADDR, 0, | |
996 | opts->addr_id); | |
997 | else | |
998 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
999 | TCPOLEN_MPTCP_ADD_ADDR_BASE, | |
1000 | MPTCP_ADDR_ECHO, | |
1001 | opts->addr_id); | |
1002 | memcpy((u8 *)ptr, (u8 *)&opts->addr.s_addr, 4); | |
1003 | ptr += 1; | |
1004 | if (opts->ahmac) { | |
1005 | put_unaligned_be64(opts->ahmac, ptr); | |
1006 | ptr += 2; | |
1007 | } | |
1008 | } | |
1009 | ||
1010 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1011 | if (OPTION_MPTCP_ADD_ADDR6 & opts->suboptions) { | |
1012 | if (opts->ahmac) | |
1013 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
1014 | TCPOLEN_MPTCP_ADD_ADDR6, 0, | |
1015 | opts->addr_id); | |
1016 | else | |
1017 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
1018 | TCPOLEN_MPTCP_ADD_ADDR6_BASE, | |
1019 | MPTCP_ADDR_ECHO, | |
1020 | opts->addr_id); | |
1021 | memcpy((u8 *)ptr, opts->addr6.s6_addr, 16); | |
1022 | ptr += 4; | |
1023 | if (opts->ahmac) { | |
1024 | put_unaligned_be64(opts->ahmac, ptr); | |
1025 | ptr += 2; | |
1026 | } | |
1027 | } | |
1028 | #endif | |
1029 | ||
1030 | if (OPTION_MPTCP_RM_ADDR & opts->suboptions) { | |
1031 | *ptr++ = mptcp_option(MPTCPOPT_RM_ADDR, | |
1032 | TCPOLEN_MPTCP_RM_ADDR_BASE, | |
1033 | 0, opts->rm_id); | |
1034 | } | |
1035 | ||
ec3edaa7 PK |
1036 | if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) { |
1037 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
1038 | TCPOLEN_MPTCP_MPJ_SYN, | |
1039 | opts->backup, opts->join_id); | |
1040 | put_unaligned_be32(opts->token, ptr); | |
1041 | ptr += 1; | |
1042 | put_unaligned_be32(opts->nonce, ptr); | |
1043 | ptr += 1; | |
1044 | } | |
1045 | ||
f296234c PK |
1046 | if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) { |
1047 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
1048 | TCPOLEN_MPTCP_MPJ_SYNACK, | |
1049 | opts->backup, opts->join_id); | |
1050 | put_unaligned_be64(opts->thmac, ptr); | |
1051 | ptr += 2; | |
1052 | put_unaligned_be32(opts->nonce, ptr); | |
1053 | ptr += 1; | |
1054 | } | |
1055 | ||
ec3edaa7 PK |
1056 | if (OPTION_MPTCP_MPJ_ACK & opts->suboptions) { |
1057 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
1058 | TCPOLEN_MPTCP_MPJ_ACK, 0, 0); | |
1059 | memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN); | |
1060 | ptr += 5; | |
1061 | } | |
1062 | ||
6d0060f6 MM |
1063 | if (opts->ext_copy.use_ack || opts->ext_copy.use_map) { |
1064 | struct mptcp_ext *mpext = &opts->ext_copy; | |
1065 | u8 len = TCPOLEN_MPTCP_DSS_BASE; | |
1066 | u8 flags = 0; | |
1067 | ||
1068 | if (mpext->use_ack) { | |
a0c1d0ea CP |
1069 | flags = MPTCP_DSS_HAS_ACK; |
1070 | if (mpext->ack64) { | |
1071 | len += TCPOLEN_MPTCP_DSS_ACK64; | |
1072 | flags |= MPTCP_DSS_ACK64; | |
1073 | } else { | |
1074 | len += TCPOLEN_MPTCP_DSS_ACK32; | |
1075 | } | |
6d0060f6 MM |
1076 | } |
1077 | ||
1078 | if (mpext->use_map) { | |
1079 | len += TCPOLEN_MPTCP_DSS_MAP64; | |
1080 | ||
1081 | /* Use only 64-bit mapping flags for now, add | |
1082 | * support for optional 32-bit mappings later. | |
1083 | */ | |
1084 | flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64; | |
1085 | if (mpext->data_fin) | |
1086 | flags |= MPTCP_DSS_DATA_FIN; | |
1087 | } | |
1088 | ||
3df523ab | 1089 | *ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags); |
6d0060f6 MM |
1090 | |
1091 | if (mpext->use_ack) { | |
a0c1d0ea CP |
1092 | if (mpext->ack64) { |
1093 | put_unaligned_be64(mpext->data_ack, ptr); | |
1094 | ptr += 2; | |
1095 | } else { | |
1096 | put_unaligned_be32(mpext->data_ack32, ptr); | |
1097 | ptr += 1; | |
1098 | } | |
6d0060f6 MM |
1099 | } |
1100 | ||
1101 | if (mpext->use_map) { | |
1102 | put_unaligned_be64(mpext->data_seq, ptr); | |
1103 | ptr += 2; | |
1104 | put_unaligned_be32(mpext->subflow_seq, ptr); | |
1105 | ptr += 1; | |
1106 | put_unaligned_be32(mpext->data_len << 16 | | |
1107 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); | |
1108 | } | |
1109 | } | |
eda7acdd | 1110 | } |