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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" | |
a877de06 | 14 | #include "mib.h" |
eda7acdd | 15 | |
65492c5a PA |
16 | static bool mptcp_cap_flag_sha256(u8 flags) |
17 | { | |
18 | return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256; | |
19 | } | |
20 | ||
cfde141e PA |
21 | static void mptcp_parse_option(const struct sk_buff *skb, |
22 | const unsigned char *ptr, int opsize, | |
23 | struct mptcp_options_received *mp_opt) | |
eda7acdd | 24 | { |
eda7acdd | 25 | u8 subtype = *ptr >> 4; |
648ef4b8 | 26 | int expected_opsize; |
eda7acdd PK |
27 | u8 version; |
28 | u8 flags; | |
29 | ||
30 | switch (subtype) { | |
31 | case MPTCPOPT_MP_CAPABLE: | |
cc7972ea CP |
32 | /* strict size checking */ |
33 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { | |
34 | if (skb->len > tcp_hdr(skb)->doff << 2) | |
35 | expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA; | |
36 | else | |
37 | expected_opsize = TCPOLEN_MPTCP_MPC_ACK; | |
38 | } else { | |
39 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK) | |
40 | expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK; | |
41 | else | |
42 | expected_opsize = TCPOLEN_MPTCP_MPC_SYN; | |
43 | } | |
44 | if (opsize != expected_opsize) | |
eda7acdd PK |
45 | break; |
46 | ||
cc7972ea | 47 | /* try to be gentle vs future versions on the initial syn */ |
eda7acdd | 48 | version = *ptr++ & MPTCP_VERSION_MASK; |
cc7972ea CP |
49 | if (opsize != TCPOLEN_MPTCP_MPC_SYN) { |
50 | if (version != MPTCP_SUPPORTED_VERSION) | |
51 | break; | |
52 | } else if (version < MPTCP_SUPPORTED_VERSION) { | |
eda7acdd | 53 | break; |
cc7972ea | 54 | } |
eda7acdd PK |
55 | |
56 | flags = *ptr++; | |
65492c5a | 57 | if (!mptcp_cap_flag_sha256(flags) || |
eda7acdd PK |
58 | (flags & MPTCP_CAP_EXTENSIBILITY)) |
59 | break; | |
60 | ||
61 | /* RFC 6824, Section 3.1: | |
62 | * "For the Checksum Required bit (labeled "A"), if either | |
63 | * host requires the use of checksums, checksums MUST be used. | |
64 | * In other words, the only way for checksums not to be used | |
65 | * is if both hosts in their SYNs set A=0." | |
66 | * | |
67 | * Section 3.3.0: | |
68 | * "If a checksum is not present when its use has been | |
69 | * negotiated, the receiver MUST close the subflow with a RST as | |
70 | * it is considered broken." | |
71 | * | |
72 | * We don't implement DSS checksum - fall back to TCP. | |
73 | */ | |
74 | if (flags & MPTCP_CAP_CHECKSUM_REQD) | |
75 | break; | |
76 | ||
77 | mp_opt->mp_capable = 1; | |
cc7972ea CP |
78 | if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) { |
79 | mp_opt->sndr_key = get_unaligned_be64(ptr); | |
80 | ptr += 8; | |
81 | } | |
82 | if (opsize >= TCPOLEN_MPTCP_MPC_ACK) { | |
eda7acdd PK |
83 | mp_opt->rcvr_key = get_unaligned_be64(ptr); |
84 | ptr += 8; | |
eda7acdd | 85 | } |
cc7972ea CP |
86 | if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA) { |
87 | /* Section 3.1.: | |
88 | * "the data parameters in a MP_CAPABLE are semantically | |
89 | * equivalent to those in a DSS option and can be used | |
90 | * interchangeably." | |
91 | */ | |
92 | mp_opt->dss = 1; | |
93 | mp_opt->use_map = 1; | |
94 | mp_opt->mpc_map = 1; | |
95 | mp_opt->data_len = get_unaligned_be16(ptr); | |
96 | ptr += 2; | |
97 | } | |
98 | pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d", | |
99 | version, flags, opsize, mp_opt->sndr_key, | |
100 | mp_opt->rcvr_key, mp_opt->data_len); | |
eda7acdd PK |
101 | break; |
102 | ||
f296234c PK |
103 | case MPTCPOPT_MP_JOIN: |
104 | mp_opt->mp_join = 1; | |
105 | if (opsize == TCPOLEN_MPTCP_MPJ_SYN) { | |
106 | mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; | |
107 | mp_opt->join_id = *ptr++; | |
108 | mp_opt->token = get_unaligned_be32(ptr); | |
109 | ptr += 4; | |
110 | mp_opt->nonce = get_unaligned_be32(ptr); | |
111 | ptr += 4; | |
112 | pr_debug("MP_JOIN bkup=%u, id=%u, token=%u, nonce=%u", | |
113 | mp_opt->backup, mp_opt->join_id, | |
114 | mp_opt->token, mp_opt->nonce); | |
115 | } else if (opsize == TCPOLEN_MPTCP_MPJ_SYNACK) { | |
116 | mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; | |
117 | mp_opt->join_id = *ptr++; | |
118 | mp_opt->thmac = get_unaligned_be64(ptr); | |
119 | ptr += 8; | |
120 | mp_opt->nonce = get_unaligned_be32(ptr); | |
121 | ptr += 4; | |
122 | pr_debug("MP_JOIN bkup=%u, id=%u, thmac=%llu, nonce=%u", | |
123 | mp_opt->backup, mp_opt->join_id, | |
124 | mp_opt->thmac, mp_opt->nonce); | |
125 | } else if (opsize == TCPOLEN_MPTCP_MPJ_ACK) { | |
126 | ptr += 2; | |
127 | memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN); | |
128 | pr_debug("MP_JOIN hmac"); | |
129 | } else { | |
130 | pr_warn("MP_JOIN bad option size"); | |
131 | mp_opt->mp_join = 0; | |
132 | } | |
133 | break; | |
134 | ||
eda7acdd PK |
135 | case MPTCPOPT_DSS: |
136 | pr_debug("DSS"); | |
648ef4b8 MM |
137 | ptr++; |
138 | ||
cc7972ea CP |
139 | /* we must clear 'mpc_map' be able to detect MP_CAPABLE |
140 | * map vs DSS map in mptcp_incoming_options(), and reconstruct | |
141 | * map info accordingly | |
142 | */ | |
143 | mp_opt->mpc_map = 0; | |
648ef4b8 MM |
144 | flags = (*ptr++) & MPTCP_DSS_FLAG_MASK; |
145 | mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0; | |
146 | mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0; | |
147 | mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0; | |
148 | mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0; | |
149 | mp_opt->use_ack = (flags & MPTCP_DSS_HAS_ACK); | |
150 | ||
151 | pr_debug("data_fin=%d dsn64=%d use_map=%d ack64=%d use_ack=%d", | |
152 | mp_opt->data_fin, mp_opt->dsn64, | |
153 | mp_opt->use_map, mp_opt->ack64, | |
154 | mp_opt->use_ack); | |
155 | ||
156 | expected_opsize = TCPOLEN_MPTCP_DSS_BASE; | |
157 | ||
158 | if (mp_opt->use_ack) { | |
159 | if (mp_opt->ack64) | |
160 | expected_opsize += TCPOLEN_MPTCP_DSS_ACK64; | |
161 | else | |
162 | expected_opsize += TCPOLEN_MPTCP_DSS_ACK32; | |
163 | } | |
164 | ||
165 | if (mp_opt->use_map) { | |
166 | if (mp_opt->dsn64) | |
167 | expected_opsize += TCPOLEN_MPTCP_DSS_MAP64; | |
168 | else | |
169 | expected_opsize += TCPOLEN_MPTCP_DSS_MAP32; | |
170 | } | |
171 | ||
172 | /* RFC 6824, Section 3.3: | |
173 | * If a checksum is present, but its use had | |
174 | * not been negotiated in the MP_CAPABLE handshake, | |
175 | * the checksum field MUST be ignored. | |
176 | */ | |
177 | if (opsize != expected_opsize && | |
178 | opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) | |
179 | break; | |
180 | ||
eda7acdd | 181 | mp_opt->dss = 1; |
648ef4b8 MM |
182 | |
183 | if (mp_opt->use_ack) { | |
184 | if (mp_opt->ack64) { | |
185 | mp_opt->data_ack = get_unaligned_be64(ptr); | |
186 | ptr += 8; | |
187 | } else { | |
188 | mp_opt->data_ack = get_unaligned_be32(ptr); | |
189 | ptr += 4; | |
190 | } | |
191 | ||
192 | pr_debug("data_ack=%llu", mp_opt->data_ack); | |
193 | } | |
194 | ||
195 | if (mp_opt->use_map) { | |
196 | if (mp_opt->dsn64) { | |
197 | mp_opt->data_seq = get_unaligned_be64(ptr); | |
198 | ptr += 8; | |
199 | } else { | |
200 | mp_opt->data_seq = get_unaligned_be32(ptr); | |
201 | ptr += 4; | |
202 | } | |
203 | ||
204 | mp_opt->subflow_seq = get_unaligned_be32(ptr); | |
205 | ptr += 4; | |
206 | ||
207 | mp_opt->data_len = get_unaligned_be16(ptr); | |
208 | ptr += 2; | |
209 | ||
210 | pr_debug("data_seq=%llu subflow_seq=%u data_len=%u", | |
211 | mp_opt->data_seq, mp_opt->subflow_seq, | |
212 | mp_opt->data_len); | |
213 | } | |
214 | ||
eda7acdd PK |
215 | break; |
216 | ||
3df523ab PK |
217 | case MPTCPOPT_ADD_ADDR: |
218 | mp_opt->echo = (*ptr++) & MPTCP_ADDR_ECHO; | |
219 | if (!mp_opt->echo) { | |
220 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR || | |
221 | opsize == TCPOLEN_MPTCP_ADD_ADDR_PORT) | |
222 | mp_opt->family = MPTCP_ADDR_IPVERSION_4; | |
223 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
224 | else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6 || | |
225 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_PORT) | |
226 | mp_opt->family = MPTCP_ADDR_IPVERSION_6; | |
227 | #endif | |
228 | else | |
229 | break; | |
230 | } else { | |
231 | if (opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE || | |
232 | opsize == TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT) | |
233 | mp_opt->family = MPTCP_ADDR_IPVERSION_4; | |
234 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
235 | else if (opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE || | |
236 | opsize == TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT) | |
237 | mp_opt->family = MPTCP_ADDR_IPVERSION_6; | |
238 | #endif | |
239 | else | |
240 | break; | |
241 | } | |
242 | ||
243 | mp_opt->add_addr = 1; | |
3df523ab | 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; | |
fe2d9b1a | 299 | mp_opt->ahmac = 0; |
65b8c8a6 | 300 | mp_opt->port = 0; |
cfde141e PA |
301 | mp_opt->rm_addr = 0; |
302 | mp_opt->dss = 0; | |
303 | ||
304 | length = (th->doff * 4) - sizeof(struct tcphdr); | |
cec37a6e PK |
305 | ptr = (const unsigned char *)(th + 1); |
306 | ||
307 | while (length > 0) { | |
308 | int opcode = *ptr++; | |
309 | int opsize; | |
310 | ||
311 | switch (opcode) { | |
312 | case TCPOPT_EOL: | |
313 | return; | |
314 | case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ | |
315 | length--; | |
316 | continue; | |
317 | default: | |
318 | opsize = *ptr++; | |
319 | if (opsize < 2) /* "silly options" */ | |
320 | return; | |
321 | if (opsize > length) | |
322 | return; /* don't parse partial options */ | |
323 | if (opcode == TCPOPT_MPTCP) | |
cfde141e | 324 | mptcp_parse_option(skb, ptr, opsize, mp_opt); |
cec37a6e PK |
325 | ptr += opsize - 2; |
326 | length -= opsize; | |
327 | } | |
328 | } | |
329 | } | |
330 | ||
cc7972ea CP |
331 | bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb, |
332 | unsigned int *size, struct mptcp_out_options *opts) | |
cec37a6e PK |
333 | { |
334 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
335 | ||
cc7972ea CP |
336 | /* we will use snd_isn to detect first pkt [re]transmission |
337 | * in mptcp_established_options_mp() | |
338 | */ | |
339 | subflow->snd_isn = TCP_SKB_CB(skb)->end_seq; | |
cec37a6e | 340 | if (subflow->request_mptcp) { |
cec37a6e | 341 | opts->suboptions = OPTION_MPTCP_MPC_SYN; |
cec37a6e PK |
342 | *size = TCPOLEN_MPTCP_MPC_SYN; |
343 | return true; | |
ec3edaa7 PK |
344 | } else if (subflow->request_join) { |
345 | pr_debug("remote_token=%u, nonce=%u", subflow->remote_token, | |
346 | subflow->local_nonce); | |
347 | opts->suboptions = OPTION_MPTCP_MPJ_SYN; | |
348 | opts->join_id = subflow->local_id; | |
349 | opts->token = subflow->remote_token; | |
350 | opts->nonce = subflow->local_nonce; | |
351 | opts->backup = subflow->request_bkup; | |
352 | *size = TCPOLEN_MPTCP_MPJ_SYN; | |
353 | return true; | |
cec37a6e PK |
354 | } |
355 | return false; | |
356 | } | |
357 | ||
ec3edaa7 PK |
358 | /* MP_JOIN client subflow must wait for 4th ack before sending any data: |
359 | * TCP can't schedule delack timer before the subflow is fully established. | |
360 | * MPTCP uses the delack timer to do 3rd ack retransmissions | |
361 | */ | |
362 | static void schedule_3rdack_retransmission(struct sock *sk) | |
363 | { | |
364 | struct inet_connection_sock *icsk = inet_csk(sk); | |
365 | struct tcp_sock *tp = tcp_sk(sk); | |
366 | unsigned long timeout; | |
367 | ||
368 | /* reschedule with a timeout above RTT, as we must look only for drop */ | |
369 | if (tp->srtt_us) | |
370 | timeout = tp->srtt_us << 1; | |
371 | else | |
372 | timeout = TCP_TIMEOUT_INIT; | |
373 | ||
374 | WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER); | |
375 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
376 | icsk->icsk_ack.timeout = timeout; | |
377 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
378 | } | |
379 | ||
380 | static void clear_3rdack_retransmission(struct sock *sk) | |
381 | { | |
382 | struct inet_connection_sock *icsk = inet_csk(sk); | |
383 | ||
384 | sk_stop_timer(sk, &icsk->icsk_delack_timer); | |
385 | icsk->icsk_ack.timeout = 0; | |
386 | icsk->icsk_ack.ato = 0; | |
387 | icsk->icsk_ack.pending &= ~(ICSK_ACK_SCHED | ICSK_ACK_TIMER); | |
388 | } | |
389 | ||
cc7972ea CP |
390 | static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, |
391 | unsigned int *size, | |
6d0060f6 MM |
392 | unsigned int remaining, |
393 | struct mptcp_out_options *opts) | |
cec37a6e PK |
394 | { |
395 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cc7972ea CP |
396 | struct mptcp_ext *mpext; |
397 | unsigned int data_len; | |
398 | ||
ec3edaa7 PK |
399 | /* When skb is not available, we better over-estimate the emitted |
400 | * options len. A full DSS option (28 bytes) is longer than | |
401 | * TCPOLEN_MPTCP_MPC_ACK_DATA(22) or TCPOLEN_MPTCP_MPJ_ACK(24), so | |
402 | * tell the caller to defer the estimate to | |
403 | * mptcp_established_options_dss(), which will reserve enough space. | |
404 | */ | |
405 | if (!skb) | |
406 | return false; | |
cc7972ea | 407 | |
ec3edaa7 PK |
408 | /* MPC/MPJ needed only on 3rd ack packet */ |
409 | if (subflow->fully_established || | |
410 | subflow->snd_isn != TCP_SKB_CB(skb)->seq) | |
411 | return false; | |
412 | ||
413 | if (subflow->mp_capable) { | |
cc7972ea CP |
414 | mpext = mptcp_get_ext(skb); |
415 | data_len = mpext ? mpext->data_len : 0; | |
cec37a6e | 416 | |
cc7972ea CP |
417 | /* we will check ext_copy.data_len in mptcp_write_options() to |
418 | * discriminate between TCPOLEN_MPTCP_MPC_ACK_DATA and | |
419 | * TCPOLEN_MPTCP_MPC_ACK | |
420 | */ | |
421 | opts->ext_copy.data_len = data_len; | |
cec37a6e PK |
422 | opts->suboptions = OPTION_MPTCP_MPC_ACK; |
423 | opts->sndr_key = subflow->local_key; | |
424 | opts->rcvr_key = subflow->remote_key; | |
cc7972ea CP |
425 | |
426 | /* Section 3.1. | |
427 | * The MP_CAPABLE option is carried on the SYN, SYN/ACK, and ACK | |
428 | * packets that start the first subflow of an MPTCP connection, | |
429 | * as well as the first packet that carries data | |
430 | */ | |
431 | if (data_len > 0) | |
432 | *size = ALIGN(TCPOLEN_MPTCP_MPC_ACK_DATA, 4); | |
433 | else | |
434 | *size = TCPOLEN_MPTCP_MPC_ACK; | |
435 | ||
436 | pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d", | |
437 | subflow, subflow->local_key, subflow->remote_key, | |
438 | data_len); | |
439 | ||
cec37a6e | 440 | return true; |
ec3edaa7 PK |
441 | } else if (subflow->mp_join) { |
442 | opts->suboptions = OPTION_MPTCP_MPJ_ACK; | |
443 | memcpy(opts->hmac, subflow->hmac, MPTCPOPT_HMAC_LEN); | |
444 | *size = TCPOLEN_MPTCP_MPJ_ACK; | |
445 | pr_debug("subflow=%p", subflow); | |
446 | ||
447 | schedule_3rdack_retransmission(sk); | |
448 | return true; | |
cec37a6e PK |
449 | } |
450 | return false; | |
451 | } | |
452 | ||
6d0060f6 | 453 | static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow, |
9c29e361 | 454 | struct sk_buff *skb, struct mptcp_ext *ext) |
6d0060f6 | 455 | { |
017512a0 PA |
456 | /* The write_seq value has already been incremented, so the actual |
457 | * sequence number for the DATA_FIN is one less. | |
458 | */ | |
459 | u64 data_fin_tx_seq = READ_ONCE(mptcp_sk(subflow->conn)->write_seq) - 1; | |
7279da61 | 460 | |
9c29e361 | 461 | if (!ext->use_map || !skb->len) { |
6d0060f6 MM |
462 | /* RFC6824 requires a DSS mapping with specific values |
463 | * if DATA_FIN is set but no data payload is mapped | |
464 | */ | |
6d37a0b8 | 465 | ext->data_fin = 1; |
6d0060f6 MM |
466 | ext->use_map = 1; |
467 | ext->dsn64 = 1; | |
017512a0 | 468 | ext->data_seq = data_fin_tx_seq; |
6d0060f6 MM |
469 | ext->subflow_seq = 0; |
470 | ext->data_len = 1; | |
7279da61 | 471 | } else if (ext->data_seq + ext->data_len == data_fin_tx_seq) { |
6d37a0b8 MM |
472 | /* If there's an existing DSS mapping and it is the |
473 | * final mapping, DATA_FIN consumes 1 additional byte of | |
474 | * mapping space. | |
6d0060f6 | 475 | */ |
6d37a0b8 | 476 | ext->data_fin = 1; |
6d0060f6 MM |
477 | ext->data_len++; |
478 | } | |
479 | } | |
480 | ||
481 | static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, | |
482 | unsigned int *size, | |
483 | unsigned int remaining, | |
484 | struct mptcp_out_options *opts) | |
485 | { | |
486 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
7279da61 | 487 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
6d0060f6 | 488 | unsigned int dss_size = 0; |
7279da61 | 489 | u64 snd_data_fin_enable; |
6d0060f6 | 490 | struct mptcp_ext *mpext; |
6d0060f6 | 491 | unsigned int ack_size; |
d22f4988 | 492 | bool ret = false; |
6d0060f6 | 493 | |
0bac966a | 494 | mpext = skb ? mptcp_get_ext(skb) : NULL; |
e16163b6 | 495 | snd_data_fin_enable = mptcp_data_fin_enabled(msk); |
6d0060f6 | 496 | |
7279da61 | 497 | if (!skb || (mpext && mpext->use_map) || snd_data_fin_enable) { |
6d0060f6 MM |
498 | unsigned int map_size; |
499 | ||
500 | map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64; | |
501 | ||
502 | remaining -= map_size; | |
503 | dss_size = map_size; | |
504 | if (mpext) | |
505 | opts->ext_copy = *mpext; | |
506 | ||
7279da61 | 507 | if (skb && snd_data_fin_enable) |
9c29e361 | 508 | mptcp_write_data_fin(subflow, skb, &opts->ext_copy); |
d22f4988 CP |
509 | ret = true; |
510 | } | |
511 | ||
2398e399 PA |
512 | /* passive sockets msk will set the 'can_ack' after accept(), even |
513 | * if the first subflow may have the already the remote key handy | |
514 | */ | |
d22f4988 | 515 | opts->ext_copy.use_ack = 0; |
dc093db5 | 516 | if (!READ_ONCE(msk->can_ack)) { |
d22f4988 CP |
517 | *size = ALIGN(dss_size, 4); |
518 | return ret; | |
6d0060f6 MM |
519 | } |
520 | ||
37198e93 | 521 | if (READ_ONCE(msk->use_64bit_ack)) { |
a0c1d0ea | 522 | ack_size = TCPOLEN_MPTCP_DSS_ACK64; |
917944da | 523 | opts->ext_copy.data_ack = READ_ONCE(msk->ack_seq); |
a0c1d0ea CP |
524 | opts->ext_copy.ack64 = 1; |
525 | } else { | |
526 | ack_size = TCPOLEN_MPTCP_DSS_ACK32; | |
917944da | 527 | opts->ext_copy.data_ack32 = (uint32_t)READ_ONCE(msk->ack_seq); |
a0c1d0ea CP |
528 | opts->ext_copy.ack64 = 0; |
529 | } | |
530 | opts->ext_copy.use_ack = 1; | |
6d0060f6 MM |
531 | |
532 | /* Add kind/length/subtype/flag overhead if mapping is not populated */ | |
533 | if (dss_size == 0) | |
534 | ack_size += TCPOLEN_MPTCP_DSS_BASE; | |
535 | ||
536 | dss_size += ack_size; | |
537 | ||
6d0060f6 MM |
538 | *size = ALIGN(dss_size, 4); |
539 | return true; | |
540 | } | |
541 | ||
3df523ab PK |
542 | static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, |
543 | struct in_addr *addr) | |
544 | { | |
bd697222 | 545 | u8 hmac[SHA256_DIGEST_SIZE]; |
3df523ab PK |
546 | u8 msg[7]; |
547 | ||
548 | msg[0] = addr_id; | |
549 | memcpy(&msg[1], &addr->s_addr, 4); | |
550 | msg[5] = 0; | |
551 | msg[6] = 0; | |
552 | ||
553 | mptcp_crypto_hmac_sha(key1, key2, msg, 7, hmac); | |
554 | ||
bd697222 | 555 | return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); |
3df523ab PK |
556 | } |
557 | ||
558 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
559 | static u64 add_addr6_generate_hmac(u64 key1, u64 key2, u8 addr_id, | |
560 | struct in6_addr *addr) | |
561 | { | |
bd697222 | 562 | u8 hmac[SHA256_DIGEST_SIZE]; |
3df523ab PK |
563 | u8 msg[19]; |
564 | ||
565 | msg[0] = addr_id; | |
566 | memcpy(&msg[1], &addr->s6_addr, 16); | |
567 | msg[17] = 0; | |
568 | msg[18] = 0; | |
569 | ||
570 | mptcp_crypto_hmac_sha(key1, key2, msg, 19, hmac); | |
571 | ||
bd697222 | 572 | return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); |
3df523ab PK |
573 | } |
574 | #endif | |
575 | ||
f643b803 GT |
576 | static bool mptcp_established_options_add_addr(struct sock *sk, |
577 | unsigned int *size, | |
578 | unsigned int remaining, | |
579 | struct mptcp_out_options *opts) | |
3df523ab PK |
580 | { |
581 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
582 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
1b1c7a0e | 583 | struct mptcp_addr_info saddr; |
6a6c05a8 | 584 | bool echo; |
1b1c7a0e | 585 | int len; |
3df523ab | 586 | |
f643b803 | 587 | if (!mptcp_pm_should_add_signal(msk) || |
6a6c05a8 | 588 | !(mptcp_pm_add_addr_signal(msk, remaining, &saddr, &echo))) |
1b1c7a0e PK |
589 | return false; |
590 | ||
456afe01 | 591 | len = mptcp_add_addr_len(saddr.family, echo); |
1b1c7a0e PK |
592 | if (remaining < len) |
593 | return false; | |
3df523ab | 594 | |
1b1c7a0e PK |
595 | *size = len; |
596 | opts->addr_id = saddr.id; | |
597 | if (saddr.family == AF_INET) { | |
3df523ab | 598 | opts->suboptions |= OPTION_MPTCP_ADD_ADDR; |
1b1c7a0e | 599 | opts->addr = saddr.addr; |
6a6c05a8 GT |
600 | if (!echo) { |
601 | opts->ahmac = add_addr_generate_hmac(msk->local_key, | |
602 | msk->remote_key, | |
603 | opts->addr_id, | |
604 | &opts->addr); | |
605 | } | |
3df523ab PK |
606 | } |
607 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1b1c7a0e | 608 | else if (saddr.family == AF_INET6) { |
3df523ab | 609 | opts->suboptions |= OPTION_MPTCP_ADD_ADDR6; |
1b1c7a0e | 610 | opts->addr6 = saddr.addr6; |
6a6c05a8 GT |
611 | if (!echo) { |
612 | opts->ahmac = add_addr6_generate_hmac(msk->local_key, | |
613 | msk->remote_key, | |
614 | opts->addr_id, | |
615 | &opts->addr6); | |
616 | } | |
3df523ab PK |
617 | } |
618 | #endif | |
6a6c05a8 | 619 | pr_debug("addr_id=%d, ahmac=%llu, echo=%d", opts->addr_id, opts->ahmac, echo); |
3df523ab PK |
620 | |
621 | return true; | |
622 | } | |
623 | ||
5cb104ae GT |
624 | static bool mptcp_established_options_rm_addr(struct sock *sk, |
625 | unsigned int *size, | |
626 | unsigned int remaining, | |
627 | struct mptcp_out_options *opts) | |
628 | { | |
629 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
630 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
631 | u8 rm_id; | |
632 | ||
633 | if (!mptcp_pm_should_rm_signal(msk) || | |
634 | !(mptcp_pm_rm_addr_signal(msk, remaining, &rm_id))) | |
635 | return false; | |
636 | ||
637 | if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE) | |
638 | return false; | |
639 | ||
640 | *size = TCPOLEN_MPTCP_RM_ADDR_BASE; | |
641 | opts->suboptions |= OPTION_MPTCP_RM_ADDR; | |
642 | opts->rm_id = rm_id; | |
643 | ||
644 | pr_debug("rm_id=%d", opts->rm_id); | |
645 | ||
646 | return true; | |
647 | } | |
648 | ||
6d0060f6 MM |
649 | bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, |
650 | unsigned int *size, unsigned int remaining, | |
651 | struct mptcp_out_options *opts) | |
652 | { | |
653 | unsigned int opt_size = 0; | |
654 | bool ret = false; | |
655 | ||
3df523ab PK |
656 | opts->suboptions = 0; |
657 | ||
e1ff9e82 DC |
658 | if (unlikely(mptcp_check_fallback(sk))) |
659 | return false; | |
660 | ||
d5824847 PA |
661 | /* prevent adding of any MPTCP related options on reset packet |
662 | * until we support MP_TCPRST/MP_FASTCLOSE | |
663 | */ | |
664 | if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) | |
665 | return false; | |
666 | ||
cc7972ea | 667 | if (mptcp_established_options_mp(sk, skb, &opt_size, remaining, opts)) |
6d0060f6 MM |
668 | ret = true; |
669 | else if (mptcp_established_options_dss(sk, skb, &opt_size, remaining, | |
670 | opts)) | |
671 | ret = true; | |
672 | ||
673 | /* we reserved enough space for the above options, and exceeding the | |
674 | * TCP option space would be fatal | |
675 | */ | |
676 | if (WARN_ON_ONCE(opt_size > remaining)) | |
677 | return false; | |
678 | ||
679 | *size += opt_size; | |
680 | remaining -= opt_size; | |
f643b803 | 681 | if (mptcp_established_options_add_addr(sk, &opt_size, remaining, opts)) { |
3df523ab PK |
682 | *size += opt_size; |
683 | remaining -= opt_size; | |
684 | ret = true; | |
5cb104ae GT |
685 | } else if (mptcp_established_options_rm_addr(sk, &opt_size, remaining, opts)) { |
686 | *size += opt_size; | |
687 | remaining -= opt_size; | |
688 | ret = true; | |
3df523ab | 689 | } |
6d0060f6 MM |
690 | |
691 | return ret; | |
692 | } | |
693 | ||
cec37a6e PK |
694 | bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, |
695 | struct mptcp_out_options *opts) | |
696 | { | |
697 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
698 | ||
699 | if (subflow_req->mp_capable) { | |
700 | opts->suboptions = OPTION_MPTCP_MPC_SYNACK; | |
701 | opts->sndr_key = subflow_req->local_key; | |
702 | *size = TCPOLEN_MPTCP_MPC_SYNACK; | |
703 | pr_debug("subflow_req=%p, local_key=%llu", | |
704 | subflow_req, subflow_req->local_key); | |
705 | return true; | |
f296234c PK |
706 | } else if (subflow_req->mp_join) { |
707 | opts->suboptions = OPTION_MPTCP_MPJ_SYNACK; | |
708 | opts->backup = subflow_req->backup; | |
709 | opts->join_id = subflow_req->local_id; | |
710 | opts->thmac = subflow_req->thmac; | |
711 | opts->nonce = subflow_req->local_nonce; | |
712 | pr_debug("req=%p, bkup=%u, id=%u, thmac=%llu, nonce=%u", | |
713 | subflow_req, opts->backup, opts->join_id, | |
714 | opts->thmac, opts->nonce); | |
715 | *size = TCPOLEN_MPTCP_MPJ_SYNACK; | |
716 | return true; | |
cec37a6e PK |
717 | } |
718 | return false; | |
719 | } | |
720 | ||
d5824847 | 721 | static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, |
f296234c | 722 | struct mptcp_subflow_context *subflow, |
0be534f5 PA |
723 | struct sk_buff *skb, |
724 | struct mptcp_options_received *mp_opt) | |
d22f4988 CP |
725 | { |
726 | /* here we can process OoO, in-window pkts, only in-sequence 4th ack | |
f296234c | 727 | * will make the subflow fully established |
d22f4988 | 728 | */ |
f296234c PK |
729 | if (likely(subflow->fully_established)) { |
730 | /* on passive sockets, check for 3rd ack retransmission | |
731 | * note that msk is always set by subflow_syn_recv_sock() | |
732 | * for mp_join subflows | |
733 | */ | |
734 | if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 && | |
735 | TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq && | |
736 | subflow->mp_join && mp_opt->mp_join && | |
737 | READ_ONCE(msk->pm.server_side)) | |
d5824847 | 738 | tcp_send_ack(ssk); |
f296234c PK |
739 | goto fully_established; |
740 | } | |
741 | ||
d5824847 PA |
742 | /* we must process OoO packets before the first subflow is fully |
743 | * established. OoO packets are instead a protocol violation | |
744 | * for MP_JOIN subflows as the peer must not send any data | |
745 | * before receiving the forth ack - cfr. RFC 8684 section 3.2. | |
f296234c | 746 | */ |
d5824847 PA |
747 | if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1) { |
748 | if (subflow->mp_join) | |
749 | goto reset; | |
f296234c | 750 | return subflow->mp_capable; |
d5824847 | 751 | } |
d22f4988 | 752 | |
5a91e32b | 753 | if (mp_opt->dss && mp_opt->use_ack) { |
f296234c PK |
754 | /* subflows are fully established as soon as we get any |
755 | * additional ack. | |
756 | */ | |
0be534f5 | 757 | subflow->fully_established = 1; |
b93df08c | 758 | WRITE_ONCE(msk->fully_established, true); |
f296234c PK |
759 | goto fully_established; |
760 | } | |
d22f4988 | 761 | |
d22f4988 | 762 | /* If the first established packet does not contain MP_CAPABLE + data |
d5824847 PA |
763 | * then fallback to TCP. Fallback scenarios requires a reset for |
764 | * MP_JOIN subflows. | |
d22f4988 CP |
765 | */ |
766 | if (!mp_opt->mp_capable) { | |
d5824847 PA |
767 | if (subflow->mp_join) |
768 | goto reset; | |
d22f4988 | 769 | subflow->mp_capable = 0; |
e1ff9e82 DC |
770 | pr_fallback(msk); |
771 | __mptcp_do_fallback(msk); | |
d22f4988 CP |
772 | return false; |
773 | } | |
f296234c | 774 | |
d6085fe1 PA |
775 | if (unlikely(!READ_ONCE(msk->pm.server_side))) |
776 | pr_warn_once("bogus mpc option on established client sk"); | |
b93df08c | 777 | mptcp_subflow_fully_established(subflow, mp_opt); |
f296234c PK |
778 | |
779 | fully_established: | |
780 | if (likely(subflow->pm_notified)) | |
781 | return true; | |
782 | ||
783 | subflow->pm_notified = 1; | |
ec3edaa7 | 784 | if (subflow->mp_join) { |
d5824847 | 785 | clear_3rdack_retransmission(ssk); |
f296234c | 786 | mptcp_pm_subflow_established(msk, subflow); |
ec3edaa7 | 787 | } else { |
f296234c | 788 | mptcp_pm_fully_established(msk); |
ec3edaa7 | 789 | } |
d22f4988 | 790 | return true; |
d5824847 PA |
791 | |
792 | reset: | |
793 | mptcp_subflow_reset(ssk); | |
794 | return false; | |
d22f4988 CP |
795 | } |
796 | ||
cc9d2566 PA |
797 | static u64 expand_ack(u64 old_ack, u64 cur_ack, bool use_64bit) |
798 | { | |
799 | u32 old_ack32, cur_ack32; | |
800 | ||
801 | if (use_64bit) | |
802 | return cur_ack; | |
803 | ||
804 | old_ack32 = (u32)old_ack; | |
805 | cur_ack32 = (u32)cur_ack; | |
806 | cur_ack = (old_ack & GENMASK_ULL(63, 32)) + cur_ack32; | |
807 | if (unlikely(before(cur_ack32, old_ack32))) | |
808 | return cur_ack + (1LL << 32); | |
809 | return cur_ack; | |
810 | } | |
811 | ||
812 | static void update_una(struct mptcp_sock *msk, | |
813 | struct mptcp_options_received *mp_opt) | |
814 | { | |
815 | u64 new_snd_una, snd_una, old_snd_una = atomic64_read(&msk->snd_una); | |
eaa2ffab | 816 | u64 snd_nxt = READ_ONCE(msk->snd_nxt); |
cc9d2566 PA |
817 | |
818 | /* avoid ack expansion on update conflict, to reduce the risk of | |
819 | * wrongly expanding to a future ack sequence number, which is way | |
820 | * more dangerous than missing an ack | |
821 | */ | |
822 | new_snd_una = expand_ack(old_snd_una, mp_opt->data_ack, mp_opt->ack64); | |
823 | ||
824 | /* ACK for data not even sent yet? Ignore. */ | |
eaa2ffab | 825 | if (after64(new_snd_una, snd_nxt)) |
cc9d2566 PA |
826 | new_snd_una = old_snd_una; |
827 | ||
828 | while (after64(new_snd_una, old_snd_una)) { | |
829 | snd_una = old_snd_una; | |
830 | old_snd_una = atomic64_cmpxchg(&msk->snd_una, snd_una, | |
831 | new_snd_una); | |
b51f9b80 PA |
832 | if (old_snd_una == snd_una) { |
833 | mptcp_data_acked((struct sock *)msk); | |
cc9d2566 | 834 | break; |
b51f9b80 | 835 | } |
cc9d2566 PA |
836 | } |
837 | } | |
838 | ||
1a49b2c2 | 839 | bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit) |
3721b9b6 MM |
840 | { |
841 | /* Skip if DATA_FIN was already received. | |
842 | * If updating simultaneously with the recvmsg loop, values | |
843 | * should match. If they mismatch, the peer is misbehaving and | |
844 | * we will prefer the most recent information. | |
845 | */ | |
846 | if (READ_ONCE(msk->rcv_data_fin) || !READ_ONCE(msk->first)) | |
847 | return false; | |
848 | ||
1a49b2c2 MM |
849 | WRITE_ONCE(msk->rcv_data_fin_seq, |
850 | expand_ack(READ_ONCE(msk->ack_seq), data_fin_seq, use_64bit)); | |
3721b9b6 MM |
851 | WRITE_ONCE(msk->rcv_data_fin, 1); |
852 | ||
853 | return true; | |
854 | } | |
855 | ||
1b1c7a0e PK |
856 | static bool add_addr_hmac_valid(struct mptcp_sock *msk, |
857 | struct mptcp_options_received *mp_opt) | |
858 | { | |
859 | u64 hmac = 0; | |
860 | ||
861 | if (mp_opt->echo) | |
862 | return true; | |
863 | ||
864 | if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) | |
865 | hmac = add_addr_generate_hmac(msk->remote_key, | |
866 | msk->local_key, | |
867 | mp_opt->addr_id, &mp_opt->addr); | |
868 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
869 | else | |
870 | hmac = add_addr6_generate_hmac(msk->remote_key, | |
871 | msk->local_key, | |
872 | mp_opt->addr_id, &mp_opt->addr6); | |
873 | #endif | |
874 | ||
875 | pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n", | |
876 | msk, (unsigned long long)hmac, | |
877 | (unsigned long long)mp_opt->ahmac); | |
878 | ||
879 | return hmac == mp_opt->ahmac; | |
880 | } | |
881 | ||
77d0cab9 | 882 | void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) |
648ef4b8 | 883 | { |
d22f4988 | 884 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1b1c7a0e | 885 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); |
cfde141e | 886 | struct mptcp_options_received mp_opt; |
648ef4b8 MM |
887 | struct mptcp_ext *mpext; |
888 | ||
e1ff9e82 DC |
889 | if (__mptcp_check_fallback(msk)) |
890 | return; | |
891 | ||
cfde141e PA |
892 | mptcp_get_options(skb, &mp_opt); |
893 | if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) | |
d22f4988 | 894 | return; |
648ef4b8 | 895 | |
cfde141e | 896 | if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) { |
1b1c7a0e PK |
897 | struct mptcp_addr_info addr; |
898 | ||
cfde141e PA |
899 | addr.port = htons(mp_opt.port); |
900 | addr.id = mp_opt.addr_id; | |
901 | if (mp_opt.family == MPTCP_ADDR_IPVERSION_4) { | |
1b1c7a0e | 902 | addr.family = AF_INET; |
cfde141e | 903 | addr.addr = mp_opt.addr; |
1b1c7a0e PK |
904 | } |
905 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
cfde141e | 906 | else if (mp_opt.family == MPTCP_ADDR_IPVERSION_6) { |
1b1c7a0e | 907 | addr.family = AF_INET6; |
cfde141e | 908 | addr.addr6 = mp_opt.addr6; |
1b1c7a0e PK |
909 | } |
910 | #endif | |
a877de06 | 911 | if (!mp_opt.echo) { |
1b1c7a0e | 912 | mptcp_pm_add_addr_received(msk, &addr); |
a877de06 GT |
913 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR); |
914 | } else { | |
00cfd77b | 915 | mptcp_pm_del_add_timer(msk, &addr); |
a877de06 GT |
916 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD); |
917 | } | |
cfde141e | 918 | mp_opt.add_addr = 0; |
1b1c7a0e PK |
919 | } |
920 | ||
d0876b22 GT |
921 | if (mp_opt.rm_addr) { |
922 | mptcp_pm_rm_addr_received(msk, mp_opt.rm_id); | |
923 | mp_opt.rm_addr = 0; | |
924 | } | |
925 | ||
cfde141e | 926 | if (!mp_opt.dss) |
648ef4b8 MM |
927 | return; |
928 | ||
cc9d2566 PA |
929 | /* we can't wait for recvmsg() to update the ack_seq, otherwise |
930 | * monodirectional flows will stuck | |
931 | */ | |
cfde141e PA |
932 | if (mp_opt.use_ack) |
933 | update_una(msk, &mp_opt); | |
cc9d2566 | 934 | |
06827b34 MM |
935 | /* Zero-data-length packets are dropped by the caller and not |
936 | * propagated to the MPTCP layer, so the skb extension does not | |
937 | * need to be allocated or populated. DATA_FIN information, if | |
938 | * present, needs to be updated here before the skb is freed. | |
43b54c6e MM |
939 | */ |
940 | if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { | |
941 | if (mp_opt.data_fin && mp_opt.data_len == 1 && | |
1a49b2c2 | 942 | mptcp_update_rcv_data_fin(msk, mp_opt.data_seq, mp_opt.dsn64) && |
43b54c6e MM |
943 | schedule_work(&msk->work)) |
944 | sock_hold(subflow->conn); | |
06827b34 MM |
945 | |
946 | return; | |
43b54c6e MM |
947 | } |
948 | ||
648ef4b8 MM |
949 | mpext = skb_ext_add(skb, SKB_EXT_MPTCP); |
950 | if (!mpext) | |
951 | return; | |
952 | ||
953 | memset(mpext, 0, sizeof(*mpext)); | |
954 | ||
cfde141e PA |
955 | if (mp_opt.use_map) { |
956 | if (mp_opt.mpc_map) { | |
cc7972ea CP |
957 | /* this is an MP_CAPABLE carrying MPTCP data |
958 | * we know this map the first chunk of data | |
959 | */ | |
960 | mptcp_crypto_key_sha(subflow->remote_key, NULL, | |
961 | &mpext->data_seq); | |
962 | mpext->data_seq++; | |
963 | mpext->subflow_seq = 1; | |
964 | mpext->dsn64 = 1; | |
965 | mpext->mpc_map = 1; | |
a77895db | 966 | mpext->data_fin = 0; |
cc7972ea | 967 | } else { |
cfde141e PA |
968 | mpext->data_seq = mp_opt.data_seq; |
969 | mpext->subflow_seq = mp_opt.subflow_seq; | |
970 | mpext->dsn64 = mp_opt.dsn64; | |
971 | mpext->data_fin = mp_opt.data_fin; | |
cc7972ea | 972 | } |
cfde141e | 973 | mpext->data_len = mp_opt.data_len; |
648ef4b8 | 974 | mpext->use_map = 1; |
648ef4b8 | 975 | } |
648ef4b8 MM |
976 | } |
977 | ||
eda7acdd PK |
978 | void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts) |
979 | { | |
cc7972ea | 980 | if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | |
eda7acdd PK |
981 | OPTION_MPTCP_MPC_ACK) & opts->suboptions) { |
982 | u8 len; | |
983 | ||
984 | if (OPTION_MPTCP_MPC_SYN & opts->suboptions) | |
985 | len = TCPOLEN_MPTCP_MPC_SYN; | |
cec37a6e PK |
986 | else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) |
987 | len = TCPOLEN_MPTCP_MPC_SYNACK; | |
cc7972ea CP |
988 | else if (opts->ext_copy.data_len) |
989 | len = TCPOLEN_MPTCP_MPC_ACK_DATA; | |
eda7acdd PK |
990 | else |
991 | len = TCPOLEN_MPTCP_MPC_ACK; | |
992 | ||
3df523ab PK |
993 | *ptr++ = mptcp_option(MPTCPOPT_MP_CAPABLE, len, |
994 | MPTCP_SUPPORTED_VERSION, | |
995 | MPTCP_CAP_HMAC_SHA256); | |
cc7972ea CP |
996 | |
997 | if (!((OPTION_MPTCP_MPC_SYNACK | OPTION_MPTCP_MPC_ACK) & | |
998 | opts->suboptions)) | |
999 | goto mp_capable_done; | |
1000 | ||
eda7acdd PK |
1001 | put_unaligned_be64(opts->sndr_key, ptr); |
1002 | ptr += 2; | |
cc7972ea CP |
1003 | if (!((OPTION_MPTCP_MPC_ACK) & opts->suboptions)) |
1004 | goto mp_capable_done; | |
1005 | ||
1006 | put_unaligned_be64(opts->rcvr_key, ptr); | |
1007 | ptr += 2; | |
1008 | if (!opts->ext_copy.data_len) | |
1009 | goto mp_capable_done; | |
1010 | ||
1011 | put_unaligned_be32(opts->ext_copy.data_len << 16 | | |
1012 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); | |
1013 | ptr += 1; | |
eda7acdd | 1014 | } |
6d0060f6 | 1015 | |
cc7972ea | 1016 | mp_capable_done: |
3df523ab PK |
1017 | if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) { |
1018 | if (opts->ahmac) | |
1019 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
1020 | TCPOLEN_MPTCP_ADD_ADDR, 0, | |
1021 | opts->addr_id); | |
1022 | else | |
1023 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
1024 | TCPOLEN_MPTCP_ADD_ADDR_BASE, | |
1025 | MPTCP_ADDR_ECHO, | |
1026 | opts->addr_id); | |
1027 | memcpy((u8 *)ptr, (u8 *)&opts->addr.s_addr, 4); | |
1028 | ptr += 1; | |
1029 | if (opts->ahmac) { | |
1030 | put_unaligned_be64(opts->ahmac, ptr); | |
1031 | ptr += 2; | |
1032 | } | |
1033 | } | |
1034 | ||
1035 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1036 | if (OPTION_MPTCP_ADD_ADDR6 & opts->suboptions) { | |
1037 | if (opts->ahmac) | |
1038 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
1039 | TCPOLEN_MPTCP_ADD_ADDR6, 0, | |
1040 | opts->addr_id); | |
1041 | else | |
1042 | *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR, | |
1043 | TCPOLEN_MPTCP_ADD_ADDR6_BASE, | |
1044 | MPTCP_ADDR_ECHO, | |
1045 | opts->addr_id); | |
1046 | memcpy((u8 *)ptr, opts->addr6.s6_addr, 16); | |
1047 | ptr += 4; | |
1048 | if (opts->ahmac) { | |
1049 | put_unaligned_be64(opts->ahmac, ptr); | |
1050 | ptr += 2; | |
1051 | } | |
1052 | } | |
1053 | #endif | |
1054 | ||
1055 | if (OPTION_MPTCP_RM_ADDR & opts->suboptions) { | |
1056 | *ptr++ = mptcp_option(MPTCPOPT_RM_ADDR, | |
1057 | TCPOLEN_MPTCP_RM_ADDR_BASE, | |
1058 | 0, opts->rm_id); | |
1059 | } | |
1060 | ||
ec3edaa7 PK |
1061 | if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) { |
1062 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
1063 | TCPOLEN_MPTCP_MPJ_SYN, | |
1064 | opts->backup, opts->join_id); | |
1065 | put_unaligned_be32(opts->token, ptr); | |
1066 | ptr += 1; | |
1067 | put_unaligned_be32(opts->nonce, ptr); | |
1068 | ptr += 1; | |
1069 | } | |
1070 | ||
f296234c PK |
1071 | if (OPTION_MPTCP_MPJ_SYNACK & opts->suboptions) { |
1072 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
1073 | TCPOLEN_MPTCP_MPJ_SYNACK, | |
1074 | opts->backup, opts->join_id); | |
1075 | put_unaligned_be64(opts->thmac, ptr); | |
1076 | ptr += 2; | |
1077 | put_unaligned_be32(opts->nonce, ptr); | |
1078 | ptr += 1; | |
1079 | } | |
1080 | ||
ec3edaa7 PK |
1081 | if (OPTION_MPTCP_MPJ_ACK & opts->suboptions) { |
1082 | *ptr++ = mptcp_option(MPTCPOPT_MP_JOIN, | |
1083 | TCPOLEN_MPTCP_MPJ_ACK, 0, 0); | |
1084 | memcpy(ptr, opts->hmac, MPTCPOPT_HMAC_LEN); | |
1085 | ptr += 5; | |
1086 | } | |
1087 | ||
6d0060f6 MM |
1088 | if (opts->ext_copy.use_ack || opts->ext_copy.use_map) { |
1089 | struct mptcp_ext *mpext = &opts->ext_copy; | |
1090 | u8 len = TCPOLEN_MPTCP_DSS_BASE; | |
1091 | u8 flags = 0; | |
1092 | ||
1093 | if (mpext->use_ack) { | |
a0c1d0ea CP |
1094 | flags = MPTCP_DSS_HAS_ACK; |
1095 | if (mpext->ack64) { | |
1096 | len += TCPOLEN_MPTCP_DSS_ACK64; | |
1097 | flags |= MPTCP_DSS_ACK64; | |
1098 | } else { | |
1099 | len += TCPOLEN_MPTCP_DSS_ACK32; | |
1100 | } | |
6d0060f6 MM |
1101 | } |
1102 | ||
1103 | if (mpext->use_map) { | |
1104 | len += TCPOLEN_MPTCP_DSS_MAP64; | |
1105 | ||
1106 | /* Use only 64-bit mapping flags for now, add | |
1107 | * support for optional 32-bit mappings later. | |
1108 | */ | |
1109 | flags |= MPTCP_DSS_HAS_MAP | MPTCP_DSS_DSN64; | |
1110 | if (mpext->data_fin) | |
1111 | flags |= MPTCP_DSS_DATA_FIN; | |
1112 | } | |
1113 | ||
3df523ab | 1114 | *ptr++ = mptcp_option(MPTCPOPT_DSS, len, 0, flags); |
6d0060f6 MM |
1115 | |
1116 | if (mpext->use_ack) { | |
a0c1d0ea CP |
1117 | if (mpext->ack64) { |
1118 | put_unaligned_be64(mpext->data_ack, ptr); | |
1119 | ptr += 2; | |
1120 | } else { | |
1121 | put_unaligned_be32(mpext->data_ack32, ptr); | |
1122 | ptr += 1; | |
1123 | } | |
6d0060f6 MM |
1124 | } |
1125 | ||
1126 | if (mpext->use_map) { | |
1127 | put_unaligned_be64(mpext->data_seq, ptr); | |
1128 | ptr += 2; | |
1129 | put_unaligned_be32(mpext->subflow_seq, ptr); | |
1130 | ptr += 1; | |
1131 | put_unaligned_be32(mpext->data_len << 16 | | |
1132 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); | |
1133 | } | |
1134 | } | |
eda7acdd | 1135 | } |