Commit | Line | Data |
---|---|---|
2303f994 PK |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Multipath TCP | |
3 | * | |
4 | * Copyright (c) 2017 - 2019, Intel Corporation. | |
5 | */ | |
6 | ||
79c0949e PK |
7 | #define pr_fmt(fmt) "MPTCP: " fmt |
8 | ||
2303f994 PK |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/netdevice.h> | |
f296234c | 12 | #include <crypto/algapi.h> |
2303f994 PK |
13 | #include <net/sock.h> |
14 | #include <net/inet_common.h> | |
15 | #include <net/inet_hashtables.h> | |
16 | #include <net/protocol.h> | |
17 | #include <net/tcp.h> | |
cec37a6e PK |
18 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
19 | #include <net/ip6_route.h> | |
20 | #endif | |
2303f994 PK |
21 | #include <net/mptcp.h> |
22 | #include "protocol.h" | |
fc518953 FW |
23 | #include "mib.h" |
24 | ||
25 | static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, | |
26 | enum linux_mptcp_mib_field field) | |
27 | { | |
28 | MPTCP_INC_STATS(sock_net(req_to_sk(req)), field); | |
29 | } | |
2303f994 | 30 | |
79c0949e PK |
31 | static int subflow_rebuild_header(struct sock *sk) |
32 | { | |
33 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
ec3edaa7 | 34 | int local_id, err = 0; |
79c0949e PK |
35 | |
36 | if (subflow->request_mptcp && !subflow->token) { | |
37 | pr_debug("subflow=%p", sk); | |
38 | err = mptcp_token_new_connect(sk); | |
ec3edaa7 PK |
39 | } else if (subflow->request_join && !subflow->local_nonce) { |
40 | struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn; | |
41 | ||
42 | pr_debug("subflow=%p", sk); | |
43 | ||
44 | do { | |
45 | get_random_bytes(&subflow->local_nonce, sizeof(u32)); | |
46 | } while (!subflow->local_nonce); | |
47 | ||
48 | if (subflow->local_id) | |
49 | goto out; | |
50 | ||
51 | local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); | |
52 | if (local_id < 0) | |
53 | return -EINVAL; | |
54 | ||
55 | subflow->local_id = local_id; | |
79c0949e PK |
56 | } |
57 | ||
ec3edaa7 | 58 | out: |
79c0949e PK |
59 | if (err) |
60 | return err; | |
61 | ||
62 | return subflow->icsk_af_ops->rebuild_header(sk); | |
63 | } | |
64 | ||
65 | static void subflow_req_destructor(struct request_sock *req) | |
66 | { | |
67 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
68 | ||
69 | pr_debug("subflow_req=%p", subflow_req); | |
70 | ||
71 | if (subflow_req->mp_capable) | |
72 | mptcp_token_destroy_request(subflow_req->token); | |
73 | tcp_request_sock_ops.destructor(req); | |
74 | } | |
75 | ||
f296234c PK |
76 | static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2, |
77 | void *hmac) | |
78 | { | |
79 | u8 msg[8]; | |
80 | ||
81 | put_unaligned_be32(nonce1, &msg[0]); | |
82 | put_unaligned_be32(nonce2, &msg[4]); | |
83 | ||
84 | mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac); | |
85 | } | |
86 | ||
87 | /* validate received token and create truncated hmac and nonce for SYN-ACK */ | |
88 | static bool subflow_token_join_request(struct request_sock *req, | |
89 | const struct sk_buff *skb) | |
90 | { | |
91 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
92 | u8 hmac[MPTCPOPT_HMAC_LEN]; | |
93 | struct mptcp_sock *msk; | |
94 | int local_id; | |
95 | ||
96 | msk = mptcp_token_get_sock(subflow_req->token); | |
97 | if (!msk) { | |
fc518953 | 98 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINNOTOKEN); |
f296234c PK |
99 | return false; |
100 | } | |
101 | ||
102 | local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); | |
103 | if (local_id < 0) { | |
104 | sock_put((struct sock *)msk); | |
105 | return false; | |
106 | } | |
107 | subflow_req->local_id = local_id; | |
108 | ||
109 | get_random_bytes(&subflow_req->local_nonce, sizeof(u32)); | |
110 | ||
111 | subflow_generate_hmac(msk->local_key, msk->remote_key, | |
112 | subflow_req->local_nonce, | |
113 | subflow_req->remote_nonce, hmac); | |
114 | ||
115 | subflow_req->thmac = get_unaligned_be64(hmac); | |
116 | ||
117 | sock_put((struct sock *)msk); | |
118 | return true; | |
119 | } | |
120 | ||
cec37a6e PK |
121 | static void subflow_init_req(struct request_sock *req, |
122 | const struct sock *sk_listener, | |
123 | struct sk_buff *skb) | |
124 | { | |
125 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
126 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
127 | struct tcp_options_received rx_opt; | |
128 | ||
129 | pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); | |
130 | ||
131 | memset(&rx_opt.mptcp, 0, sizeof(rx_opt.mptcp)); | |
132 | mptcp_get_options(skb, &rx_opt); | |
133 | ||
134 | subflow_req->mp_capable = 0; | |
f296234c | 135 | subflow_req->mp_join = 0; |
d22f4988 | 136 | subflow_req->remote_key_valid = 0; |
cec37a6e PK |
137 | |
138 | #ifdef CONFIG_TCP_MD5SIG | |
139 | /* no MPTCP if MD5SIG is enabled on this socket or we may run out of | |
140 | * TCP option space. | |
141 | */ | |
142 | if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) | |
143 | return; | |
144 | #endif | |
145 | ||
fc518953 FW |
146 | if (rx_opt.mptcp.mp_capable) { |
147 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); | |
148 | ||
149 | if (rx_opt.mptcp.mp_join) | |
150 | return; | |
151 | } else if (rx_opt.mptcp.mp_join) { | |
152 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); | |
153 | } | |
f296234c | 154 | |
cec37a6e | 155 | if (rx_opt.mptcp.mp_capable && listener->request_mptcp) { |
79c0949e PK |
156 | int err; |
157 | ||
158 | err = mptcp_token_new_request(req); | |
159 | if (err == 0) | |
160 | subflow_req->mp_capable = 1; | |
161 | ||
648ef4b8 | 162 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
f296234c | 163 | } else if (rx_opt.mptcp.mp_join && listener->request_mptcp) { |
ec3edaa7 | 164 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
f296234c PK |
165 | subflow_req->mp_join = 1; |
166 | subflow_req->backup = rx_opt.mptcp.backup; | |
167 | subflow_req->remote_id = rx_opt.mptcp.join_id; | |
168 | subflow_req->token = rx_opt.mptcp.token; | |
169 | subflow_req->remote_nonce = rx_opt.mptcp.nonce; | |
170 | pr_debug("token=%u, remote_nonce=%u", subflow_req->token, | |
171 | subflow_req->remote_nonce); | |
172 | if (!subflow_token_join_request(req, skb)) { | |
173 | subflow_req->mp_join = 0; | |
174 | // @@ need to trigger RST | |
175 | } | |
cec37a6e PK |
176 | } |
177 | } | |
178 | ||
179 | static void subflow_v4_init_req(struct request_sock *req, | |
180 | const struct sock *sk_listener, | |
181 | struct sk_buff *skb) | |
182 | { | |
183 | tcp_rsk(req)->is_mptcp = 1; | |
184 | ||
185 | tcp_request_sock_ipv4_ops.init_req(req, sk_listener, skb); | |
186 | ||
187 | subflow_init_req(req, sk_listener, skb); | |
188 | } | |
189 | ||
190 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
191 | static void subflow_v6_init_req(struct request_sock *req, | |
192 | const struct sock *sk_listener, | |
193 | struct sk_buff *skb) | |
194 | { | |
195 | tcp_rsk(req)->is_mptcp = 1; | |
196 | ||
197 | tcp_request_sock_ipv6_ops.init_req(req, sk_listener, skb); | |
198 | ||
199 | subflow_init_req(req, sk_listener, skb); | |
200 | } | |
201 | #endif | |
202 | ||
ec3edaa7 PK |
203 | /* validate received truncated hmac and create hmac for third ACK */ |
204 | static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) | |
205 | { | |
206 | u8 hmac[MPTCPOPT_HMAC_LEN]; | |
207 | u64 thmac; | |
208 | ||
209 | subflow_generate_hmac(subflow->remote_key, subflow->local_key, | |
210 | subflow->remote_nonce, subflow->local_nonce, | |
211 | hmac); | |
212 | ||
213 | thmac = get_unaligned_be64(hmac); | |
214 | pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", | |
215 | subflow, subflow->token, | |
216 | (unsigned long long)thmac, | |
217 | (unsigned long long)subflow->thmac); | |
218 | ||
219 | return thmac == subflow->thmac; | |
220 | } | |
221 | ||
cec37a6e PK |
222 | static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) |
223 | { | |
224 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
c3c123d1 | 225 | struct sock *parent = subflow->conn; |
cec37a6e PK |
226 | |
227 | subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); | |
228 | ||
c3c123d1 DC |
229 | if (inet_sk_state_load(parent) != TCP_ESTABLISHED) { |
230 | inet_sk_state_store(parent, TCP_ESTABLISHED); | |
231 | parent->sk_state_change(parent); | |
232 | } | |
233 | ||
ec3edaa7 PK |
234 | if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp) |
235 | return; | |
236 | ||
237 | if (subflow->mp_capable) { | |
cec37a6e PK |
238 | pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk), |
239 | subflow->remote_key); | |
240 | mptcp_finish_connect(sk); | |
241 | subflow->conn_finished = 1; | |
648ef4b8 MM |
242 | |
243 | if (skb) { | |
244 | pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq); | |
245 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; | |
246 | } | |
ec3edaa7 PK |
247 | } else if (subflow->mp_join) { |
248 | pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", | |
249 | subflow, subflow->thmac, | |
250 | subflow->remote_nonce); | |
251 | if (!subflow_thmac_valid(subflow)) { | |
fc518953 | 252 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC); |
ec3edaa7 PK |
253 | subflow->mp_join = 0; |
254 | goto do_reset; | |
255 | } | |
256 | ||
257 | subflow_generate_hmac(subflow->local_key, subflow->remote_key, | |
258 | subflow->local_nonce, | |
259 | subflow->remote_nonce, | |
260 | subflow->hmac); | |
261 | ||
262 | if (skb) | |
263 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; | |
264 | ||
265 | if (!mptcp_finish_join(sk)) | |
266 | goto do_reset; | |
267 | ||
268 | subflow->conn_finished = 1; | |
fc518953 | 269 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); |
ec3edaa7 PK |
270 | } else { |
271 | do_reset: | |
272 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
273 | tcp_done(sk); | |
cec37a6e PK |
274 | } |
275 | } | |
276 | ||
277 | static struct request_sock_ops subflow_request_sock_ops; | |
278 | static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops; | |
279 | ||
280 | static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
281 | { | |
282 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
283 | ||
284 | pr_debug("subflow=%p", subflow); | |
285 | ||
286 | /* Never answer to SYNs sent to broadcast or multicast */ | |
287 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
288 | goto drop; | |
289 | ||
290 | return tcp_conn_request(&subflow_request_sock_ops, | |
291 | &subflow_request_sock_ipv4_ops, | |
292 | sk, skb); | |
293 | drop: | |
294 | tcp_listendrop(sk); | |
295 | return 0; | |
296 | } | |
297 | ||
298 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
299 | static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; | |
300 | static struct inet_connection_sock_af_ops subflow_v6_specific; | |
301 | static struct inet_connection_sock_af_ops subflow_v6m_specific; | |
302 | ||
303 | static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) | |
304 | { | |
305 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
306 | ||
307 | pr_debug("subflow=%p", subflow); | |
308 | ||
309 | if (skb->protocol == htons(ETH_P_IP)) | |
310 | return subflow_v4_conn_request(sk, skb); | |
311 | ||
312 | if (!ipv6_unicast_destination(skb)) | |
313 | goto drop; | |
314 | ||
315 | return tcp_conn_request(&subflow_request_sock_ops, | |
316 | &subflow_request_sock_ipv6_ops, sk, skb); | |
317 | ||
318 | drop: | |
319 | tcp_listendrop(sk); | |
320 | return 0; /* don't send reset */ | |
321 | } | |
322 | #endif | |
323 | ||
f296234c PK |
324 | /* validate hmac received in third ACK */ |
325 | static bool subflow_hmac_valid(const struct request_sock *req, | |
326 | const struct tcp_options_received *rx_opt) | |
327 | { | |
328 | const struct mptcp_subflow_request_sock *subflow_req; | |
329 | u8 hmac[MPTCPOPT_HMAC_LEN]; | |
330 | struct mptcp_sock *msk; | |
331 | bool ret; | |
332 | ||
333 | subflow_req = mptcp_subflow_rsk(req); | |
334 | msk = mptcp_token_get_sock(subflow_req->token); | |
335 | if (!msk) | |
336 | return false; | |
337 | ||
338 | subflow_generate_hmac(msk->remote_key, msk->local_key, | |
339 | subflow_req->remote_nonce, | |
340 | subflow_req->local_nonce, hmac); | |
341 | ||
342 | ret = true; | |
343 | if (crypto_memneq(hmac, rx_opt->mptcp.hmac, sizeof(hmac))) | |
344 | ret = false; | |
345 | ||
346 | sock_put((struct sock *)msk); | |
347 | return ret; | |
348 | } | |
349 | ||
cec37a6e PK |
350 | static struct sock *subflow_syn_recv_sock(const struct sock *sk, |
351 | struct sk_buff *skb, | |
352 | struct request_sock *req, | |
353 | struct dst_entry *dst, | |
354 | struct request_sock *req_unhash, | |
355 | bool *own_req) | |
356 | { | |
357 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk); | |
cc7972ea CP |
358 | struct mptcp_subflow_request_sock *subflow_req; |
359 | struct tcp_options_received opt_rx; | |
f296234c | 360 | bool fallback_is_fatal = false; |
58b09919 | 361 | struct sock *new_msk = NULL; |
cec37a6e PK |
362 | struct sock *child; |
363 | ||
364 | pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); | |
365 | ||
ae2dd716 FW |
366 | if (tcp_rsk(req)->is_mptcp == 0) |
367 | goto create_child; | |
368 | ||
d22f4988 | 369 | /* if the sk is MP_CAPABLE, we try to fetch the client key */ |
cc7972ea CP |
370 | subflow_req = mptcp_subflow_rsk(req); |
371 | if (subflow_req->mp_capable) { | |
d22f4988 CP |
372 | if (TCP_SKB_CB(skb)->seq != subflow_req->ssn_offset + 1) { |
373 | /* here we can receive and accept an in-window, | |
374 | * out-of-order pkt, which will not carry the MP_CAPABLE | |
375 | * opt even on mptcp enabled paths | |
376 | */ | |
58b09919 | 377 | goto create_msk; |
d22f4988 CP |
378 | } |
379 | ||
cc7972ea CP |
380 | opt_rx.mptcp.mp_capable = 0; |
381 | mptcp_get_options(skb, &opt_rx); | |
d22f4988 | 382 | if (opt_rx.mptcp.mp_capable) { |
cc7972ea | 383 | subflow_req->remote_key = opt_rx.mptcp.sndr_key; |
d22f4988 CP |
384 | subflow_req->remote_key_valid = 1; |
385 | } else { | |
386 | subflow_req->mp_capable = 0; | |
58b09919 | 387 | goto create_child; |
d22f4988 | 388 | } |
58b09919 PA |
389 | |
390 | create_msk: | |
391 | new_msk = mptcp_sk_clone(listener->conn, req); | |
392 | if (!new_msk) | |
393 | subflow_req->mp_capable = 0; | |
f296234c PK |
394 | } else if (subflow_req->mp_join) { |
395 | fallback_is_fatal = true; | |
396 | opt_rx.mptcp.mp_join = 0; | |
397 | mptcp_get_options(skb, &opt_rx); | |
398 | if (!opt_rx.mptcp.mp_join || | |
fc518953 FW |
399 | !subflow_hmac_valid(req, &opt_rx)) { |
400 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); | |
f296234c | 401 | return NULL; |
fc518953 | 402 | } |
cc7972ea | 403 | } |
cec37a6e | 404 | |
d22f4988 | 405 | create_child: |
cec37a6e PK |
406 | child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, |
407 | req_unhash, own_req); | |
408 | ||
409 | if (child && *own_req) { | |
79c0949e PK |
410 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); |
411 | ||
f296234c PK |
412 | /* we have null ctx on TCP fallback, which is fatal on |
413 | * MPJ handshake | |
79c0949e | 414 | */ |
f296234c PK |
415 | if (!ctx) { |
416 | if (fallback_is_fatal) | |
417 | goto close_child; | |
58b09919 | 418 | goto out; |
f296234c | 419 | } |
79c0949e PK |
420 | |
421 | if (ctx->mp_capable) { | |
58b09919 PA |
422 | /* new mpc subflow takes ownership of the newly |
423 | * created mptcp socket | |
424 | */ | |
1b1c7a0e PK |
425 | inet_sk_state_store(new_msk, TCP_ESTABLISHED); |
426 | mptcp_pm_new_connection(mptcp_sk(new_msk), 1); | |
58b09919 PA |
427 | ctx->conn = new_msk; |
428 | new_msk = NULL; | |
f296234c PK |
429 | } else if (ctx->mp_join) { |
430 | struct mptcp_sock *owner; | |
431 | ||
432 | owner = mptcp_token_get_sock(ctx->token); | |
433 | if (!owner) | |
434 | goto close_child; | |
435 | ||
436 | ctx->conn = (struct sock *)owner; | |
437 | if (!mptcp_finish_join(child)) | |
438 | goto close_child; | |
fc518953 FW |
439 | |
440 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); | |
cec37a6e PK |
441 | } |
442 | } | |
443 | ||
58b09919 PA |
444 | out: |
445 | /* dispose of the left over mptcp master, if any */ | |
446 | if (unlikely(new_msk)) | |
447 | sock_put(new_msk); | |
cec37a6e | 448 | return child; |
f296234c PK |
449 | |
450 | close_child: | |
451 | tcp_send_active_reset(child, GFP_ATOMIC); | |
452 | inet_csk_prepare_forced_close(child); | |
453 | tcp_done(child); | |
454 | return NULL; | |
cec37a6e PK |
455 | } |
456 | ||
457 | static struct inet_connection_sock_af_ops subflow_specific; | |
458 | ||
648ef4b8 MM |
459 | enum mapping_status { |
460 | MAPPING_OK, | |
461 | MAPPING_INVALID, | |
462 | MAPPING_EMPTY, | |
463 | MAPPING_DATA_FIN | |
464 | }; | |
465 | ||
466 | static u64 expand_seq(u64 old_seq, u16 old_data_len, u64 seq) | |
467 | { | |
468 | if ((u32)seq == (u32)old_seq) | |
469 | return old_seq; | |
470 | ||
471 | /* Assume map covers data not mapped yet. */ | |
472 | return seq | ((old_seq + old_data_len + 1) & GENMASK_ULL(63, 32)); | |
473 | } | |
474 | ||
475 | static void warn_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) | |
476 | { | |
477 | WARN_ONCE(1, "Bad mapping: ssn=%d map_seq=%d map_data_len=%d", | |
478 | ssn, subflow->map_subflow_seq, subflow->map_data_len); | |
479 | } | |
480 | ||
481 | static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) | |
482 | { | |
483 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
484 | unsigned int skb_consumed; | |
485 | ||
486 | skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; | |
487 | if (WARN_ON_ONCE(skb_consumed >= skb->len)) | |
488 | return true; | |
489 | ||
490 | return skb->len - skb_consumed <= subflow->map_data_len - | |
491 | mptcp_subflow_get_map_offset(subflow); | |
492 | } | |
493 | ||
494 | static bool validate_mapping(struct sock *ssk, struct sk_buff *skb) | |
495 | { | |
496 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
497 | u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
498 | ||
499 | if (unlikely(before(ssn, subflow->map_subflow_seq))) { | |
500 | /* Mapping covers data later in the subflow stream, | |
501 | * currently unsupported. | |
502 | */ | |
503 | warn_bad_map(subflow, ssn); | |
504 | return false; | |
505 | } | |
506 | if (unlikely(!before(ssn, subflow->map_subflow_seq + | |
507 | subflow->map_data_len))) { | |
508 | /* Mapping does covers past subflow data, invalid */ | |
509 | warn_bad_map(subflow, ssn + skb->len); | |
510 | return false; | |
511 | } | |
512 | return true; | |
513 | } | |
514 | ||
515 | static enum mapping_status get_mapping_status(struct sock *ssk) | |
516 | { | |
517 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
518 | struct mptcp_ext *mpext; | |
519 | struct sk_buff *skb; | |
520 | u16 data_len; | |
521 | u64 map_seq; | |
522 | ||
523 | skb = skb_peek(&ssk->sk_receive_queue); | |
524 | if (!skb) | |
525 | return MAPPING_EMPTY; | |
526 | ||
527 | mpext = mptcp_get_ext(skb); | |
528 | if (!mpext || !mpext->use_map) { | |
529 | if (!subflow->map_valid && !skb->len) { | |
530 | /* the TCP stack deliver 0 len FIN pkt to the receive | |
531 | * queue, that is the only 0len pkts ever expected here, | |
532 | * and we can admit no mapping only for 0 len pkts | |
533 | */ | |
534 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) | |
535 | WARN_ONCE(1, "0len seq %d:%d flags %x", | |
536 | TCP_SKB_CB(skb)->seq, | |
537 | TCP_SKB_CB(skb)->end_seq, | |
538 | TCP_SKB_CB(skb)->tcp_flags); | |
539 | sk_eat_skb(ssk, skb); | |
540 | return MAPPING_EMPTY; | |
541 | } | |
542 | ||
543 | if (!subflow->map_valid) | |
544 | return MAPPING_INVALID; | |
545 | ||
546 | goto validate_seq; | |
547 | } | |
548 | ||
549 | pr_debug("seq=%llu is64=%d ssn=%u data_len=%u data_fin=%d", | |
550 | mpext->data_seq, mpext->dsn64, mpext->subflow_seq, | |
551 | mpext->data_len, mpext->data_fin); | |
552 | ||
553 | data_len = mpext->data_len; | |
554 | if (data_len == 0) { | |
555 | pr_err("Infinite mapping not handled"); | |
fc518953 | 556 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); |
648ef4b8 MM |
557 | return MAPPING_INVALID; |
558 | } | |
559 | ||
560 | if (mpext->data_fin == 1) { | |
561 | if (data_len == 1) { | |
562 | pr_debug("DATA_FIN with no payload"); | |
563 | if (subflow->map_valid) { | |
564 | /* A DATA_FIN might arrive in a DSS | |
565 | * option before the previous mapping | |
566 | * has been fully consumed. Continue | |
567 | * handling the existing mapping. | |
568 | */ | |
569 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
570 | return MAPPING_OK; | |
571 | } else { | |
572 | return MAPPING_DATA_FIN; | |
573 | } | |
574 | } | |
575 | ||
576 | /* Adjust for DATA_FIN using 1 byte of sequence space */ | |
577 | data_len--; | |
578 | } | |
579 | ||
580 | if (!mpext->dsn64) { | |
581 | map_seq = expand_seq(subflow->map_seq, subflow->map_data_len, | |
582 | mpext->data_seq); | |
583 | pr_debug("expanded seq=%llu", subflow->map_seq); | |
584 | } else { | |
585 | map_seq = mpext->data_seq; | |
586 | } | |
587 | ||
588 | if (subflow->map_valid) { | |
589 | /* Allow replacing only with an identical map */ | |
590 | if (subflow->map_seq == map_seq && | |
591 | subflow->map_subflow_seq == mpext->subflow_seq && | |
592 | subflow->map_data_len == data_len) { | |
593 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
594 | return MAPPING_OK; | |
595 | } | |
596 | ||
597 | /* If this skb data are fully covered by the current mapping, | |
598 | * the new map would need caching, which is not supported | |
599 | */ | |
fc518953 FW |
600 | if (skb_is_fully_mapped(ssk, skb)) { |
601 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH); | |
648ef4b8 | 602 | return MAPPING_INVALID; |
fc518953 | 603 | } |
648ef4b8 MM |
604 | |
605 | /* will validate the next map after consuming the current one */ | |
606 | return MAPPING_OK; | |
607 | } | |
608 | ||
609 | subflow->map_seq = map_seq; | |
610 | subflow->map_subflow_seq = mpext->subflow_seq; | |
611 | subflow->map_data_len = data_len; | |
612 | subflow->map_valid = 1; | |
d22f4988 | 613 | subflow->mpc_map = mpext->mpc_map; |
648ef4b8 MM |
614 | pr_debug("new map seq=%llu subflow_seq=%u data_len=%u", |
615 | subflow->map_seq, subflow->map_subflow_seq, | |
616 | subflow->map_data_len); | |
617 | ||
618 | validate_seq: | |
619 | /* we revalidate valid mapping on new skb, because we must ensure | |
620 | * the current skb is completely covered by the available mapping | |
621 | */ | |
622 | if (!validate_mapping(ssk, skb)) | |
623 | return MAPPING_INVALID; | |
624 | ||
625 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
626 | return MAPPING_OK; | |
627 | } | |
628 | ||
bfae9dae FW |
629 | static int subflow_read_actor(read_descriptor_t *desc, |
630 | struct sk_buff *skb, | |
631 | unsigned int offset, size_t len) | |
632 | { | |
633 | size_t copy_len = min(desc->count, len); | |
634 | ||
635 | desc->count -= copy_len; | |
636 | ||
637 | pr_debug("flushed %zu bytes, %zu left", copy_len, desc->count); | |
638 | return copy_len; | |
639 | } | |
640 | ||
648ef4b8 MM |
641 | static bool subflow_check_data_avail(struct sock *ssk) |
642 | { | |
643 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
644 | enum mapping_status status; | |
645 | struct mptcp_sock *msk; | |
646 | struct sk_buff *skb; | |
647 | ||
648 | pr_debug("msk=%p ssk=%p data_avail=%d skb=%p", subflow->conn, ssk, | |
649 | subflow->data_avail, skb_peek(&ssk->sk_receive_queue)); | |
650 | if (subflow->data_avail) | |
651 | return true; | |
652 | ||
648ef4b8 MM |
653 | msk = mptcp_sk(subflow->conn); |
654 | for (;;) { | |
655 | u32 map_remaining; | |
656 | size_t delta; | |
657 | u64 ack_seq; | |
658 | u64 old_ack; | |
659 | ||
660 | status = get_mapping_status(ssk); | |
661 | pr_debug("msk=%p ssk=%p status=%d", msk, ssk, status); | |
662 | if (status == MAPPING_INVALID) { | |
663 | ssk->sk_err = EBADMSG; | |
664 | goto fatal; | |
665 | } | |
666 | ||
667 | if (status != MAPPING_OK) | |
668 | return false; | |
669 | ||
670 | skb = skb_peek(&ssk->sk_receive_queue); | |
671 | if (WARN_ON_ONCE(!skb)) | |
672 | return false; | |
673 | ||
d22f4988 CP |
674 | /* if msk lacks the remote key, this subflow must provide an |
675 | * MP_CAPABLE-based mapping | |
676 | */ | |
677 | if (unlikely(!READ_ONCE(msk->can_ack))) { | |
678 | if (!subflow->mpc_map) { | |
679 | ssk->sk_err = EBADMSG; | |
680 | goto fatal; | |
681 | } | |
682 | WRITE_ONCE(msk->remote_key, subflow->remote_key); | |
683 | WRITE_ONCE(msk->ack_seq, subflow->map_seq); | |
684 | WRITE_ONCE(msk->can_ack, true); | |
685 | } | |
686 | ||
648ef4b8 MM |
687 | old_ack = READ_ONCE(msk->ack_seq); |
688 | ack_seq = mptcp_subflow_get_mapped_dsn(subflow); | |
689 | pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, | |
690 | ack_seq); | |
691 | if (ack_seq == old_ack) | |
692 | break; | |
693 | ||
694 | /* only accept in-sequence mapping. Old values are spurious | |
695 | * retransmission; we can hit "future" values on active backup | |
696 | * subflow switch, we relay on retransmissions to get | |
697 | * in-sequence data. | |
698 | * Cuncurrent subflows support will require subflow data | |
699 | * reordering | |
700 | */ | |
701 | map_remaining = subflow->map_data_len - | |
702 | mptcp_subflow_get_map_offset(subflow); | |
703 | if (before64(ack_seq, old_ack)) | |
704 | delta = min_t(size_t, old_ack - ack_seq, map_remaining); | |
705 | else | |
706 | delta = min_t(size_t, ack_seq - old_ack, map_remaining); | |
707 | ||
708 | /* discard mapped data */ | |
709 | pr_debug("discarding %zu bytes, current map len=%d", delta, | |
710 | map_remaining); | |
711 | if (delta) { | |
648ef4b8 MM |
712 | read_descriptor_t desc = { |
713 | .count = delta, | |
648ef4b8 MM |
714 | }; |
715 | int ret; | |
716 | ||
bfae9dae | 717 | ret = tcp_read_sock(ssk, &desc, subflow_read_actor); |
648ef4b8 MM |
718 | if (ret < 0) { |
719 | ssk->sk_err = -ret; | |
720 | goto fatal; | |
721 | } | |
722 | if (ret < delta) | |
723 | return false; | |
724 | if (delta == map_remaining) | |
725 | subflow->map_valid = 0; | |
726 | } | |
727 | } | |
728 | return true; | |
729 | ||
730 | fatal: | |
731 | /* fatal protocol error, close the socket */ | |
732 | /* This barrier is coupled with smp_rmb() in tcp_poll() */ | |
733 | smp_wmb(); | |
734 | ssk->sk_error_report(ssk); | |
735 | tcp_set_state(ssk, TCP_CLOSE); | |
736 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
737 | return false; | |
738 | } | |
739 | ||
740 | bool mptcp_subflow_data_available(struct sock *sk) | |
741 | { | |
742 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
743 | struct sk_buff *skb; | |
744 | ||
745 | /* check if current mapping is still valid */ | |
746 | if (subflow->map_valid && | |
747 | mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) { | |
748 | subflow->map_valid = 0; | |
749 | subflow->data_avail = 0; | |
750 | ||
751 | pr_debug("Done with mapping: seq=%u data_len=%u", | |
752 | subflow->map_subflow_seq, | |
753 | subflow->map_data_len); | |
754 | } | |
755 | ||
756 | if (!subflow_check_data_avail(sk)) { | |
757 | subflow->data_avail = 0; | |
758 | return false; | |
759 | } | |
760 | ||
761 | skb = skb_peek(&sk->sk_receive_queue); | |
762 | subflow->data_avail = skb && | |
763 | before(tcp_sk(sk)->copied_seq, TCP_SKB_CB(skb)->end_seq); | |
764 | return subflow->data_avail; | |
765 | } | |
766 | ||
767 | static void subflow_data_ready(struct sock *sk) | |
768 | { | |
769 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
770 | struct sock *parent = subflow->conn; | |
771 | ||
f296234c | 772 | if (!subflow->mp_capable && !subflow->mp_join) { |
648ef4b8 MM |
773 | subflow->tcp_data_ready(sk); |
774 | ||
dc093db5 | 775 | parent->sk_data_ready(parent); |
648ef4b8 MM |
776 | return; |
777 | } | |
778 | ||
101f6f85 | 779 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 780 | mptcp_data_ready(parent, sk); |
648ef4b8 MM |
781 | } |
782 | ||
783 | static void subflow_write_space(struct sock *sk) | |
784 | { | |
785 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
786 | struct sock *parent = subflow->conn; | |
787 | ||
788 | sk_stream_write_space(sk); | |
dc093db5 | 789 | if (sk_stream_is_writeable(sk)) { |
1891c4a0 FW |
790 | set_bit(MPTCP_SEND_SPACE, &mptcp_sk(parent)->flags); |
791 | smp_mb__after_atomic(); | |
792 | /* set SEND_SPACE before sk_stream_write_space clears NOSPACE */ | |
648ef4b8 MM |
793 | sk_stream_write_space(parent); |
794 | } | |
795 | } | |
796 | ||
cec37a6e PK |
797 | static struct inet_connection_sock_af_ops * |
798 | subflow_default_af_ops(struct sock *sk) | |
799 | { | |
800 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
801 | if (sk->sk_family == AF_INET6) | |
802 | return &subflow_v6_specific; | |
803 | #endif | |
804 | return &subflow_specific; | |
805 | } | |
806 | ||
cec37a6e | 807 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
31484d56 GU |
808 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped) |
809 | { | |
cec37a6e PK |
810 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
811 | struct inet_connection_sock *icsk = inet_csk(sk); | |
812 | struct inet_connection_sock_af_ops *target; | |
813 | ||
814 | target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk); | |
815 | ||
816 | pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d", | |
edc7e489 | 817 | subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped); |
cec37a6e PK |
818 | |
819 | if (likely(icsk->icsk_af_ops == target)) | |
820 | return; | |
821 | ||
822 | subflow->icsk_af_ops = icsk->icsk_af_ops; | |
823 | icsk->icsk_af_ops = target; | |
cec37a6e | 824 | } |
31484d56 | 825 | #endif |
cec37a6e | 826 | |
ec3edaa7 PK |
827 | static void mptcp_info2sockaddr(const struct mptcp_addr_info *info, |
828 | struct sockaddr_storage *addr) | |
829 | { | |
830 | memset(addr, 0, sizeof(*addr)); | |
831 | addr->ss_family = info->family; | |
832 | if (addr->ss_family == AF_INET) { | |
833 | struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; | |
834 | ||
835 | in_addr->sin_addr = info->addr; | |
836 | in_addr->sin_port = info->port; | |
837 | } | |
838 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
839 | else if (addr->ss_family == AF_INET6) { | |
840 | struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; | |
841 | ||
842 | in6_addr->sin6_addr = info->addr6; | |
843 | in6_addr->sin6_port = info->port; | |
844 | } | |
845 | #endif | |
846 | } | |
847 | ||
848 | int __mptcp_subflow_connect(struct sock *sk, int ifindex, | |
849 | const struct mptcp_addr_info *loc, | |
850 | const struct mptcp_addr_info *remote) | |
851 | { | |
852 | struct mptcp_sock *msk = mptcp_sk(sk); | |
853 | struct mptcp_subflow_context *subflow; | |
854 | struct sockaddr_storage addr; | |
855 | struct socket *sf; | |
856 | u32 remote_token; | |
857 | int addrlen; | |
858 | int err; | |
859 | ||
860 | if (sk->sk_state != TCP_ESTABLISHED) | |
861 | return -ENOTCONN; | |
862 | ||
863 | err = mptcp_subflow_create_socket(sk, &sf); | |
864 | if (err) | |
865 | return err; | |
866 | ||
867 | subflow = mptcp_subflow_ctx(sf->sk); | |
868 | subflow->remote_key = msk->remote_key; | |
869 | subflow->local_key = msk->local_key; | |
870 | subflow->token = msk->token; | |
871 | mptcp_info2sockaddr(loc, &addr); | |
872 | ||
873 | addrlen = sizeof(struct sockaddr_in); | |
874 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
875 | if (loc->family == AF_INET6) | |
876 | addrlen = sizeof(struct sockaddr_in6); | |
877 | #endif | |
878 | sf->sk->sk_bound_dev_if = ifindex; | |
879 | err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); | |
880 | if (err) | |
881 | goto failed; | |
882 | ||
883 | mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); | |
884 | pr_debug("msk=%p remote_token=%u", msk, remote_token); | |
885 | subflow->remote_token = remote_token; | |
886 | subflow->local_id = loc->id; | |
887 | subflow->request_join = 1; | |
888 | subflow->request_bkup = 1; | |
889 | mptcp_info2sockaddr(remote, &addr); | |
890 | ||
891 | err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); | |
892 | if (err && err != -EINPROGRESS) | |
893 | goto failed; | |
894 | ||
895 | spin_lock_bh(&msk->join_list_lock); | |
896 | list_add_tail(&subflow->node, &msk->join_list); | |
897 | spin_unlock_bh(&msk->join_list_lock); | |
898 | ||
899 | return err; | |
900 | ||
901 | failed: | |
902 | sock_release(sf); | |
903 | return err; | |
904 | } | |
905 | ||
2303f994 PK |
906 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) |
907 | { | |
908 | struct mptcp_subflow_context *subflow; | |
909 | struct net *net = sock_net(sk); | |
910 | struct socket *sf; | |
911 | int err; | |
912 | ||
cec37a6e PK |
913 | err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP, |
914 | &sf); | |
2303f994 PK |
915 | if (err) |
916 | return err; | |
917 | ||
918 | lock_sock(sf->sk); | |
919 | ||
920 | /* kernel sockets do not by default acquire net ref, but TCP timer | |
921 | * needs it. | |
922 | */ | |
923 | sf->sk->sk_net_refcnt = 1; | |
924 | get_net(net); | |
f6f7d8cf | 925 | #ifdef CONFIG_PROC_FS |
2303f994 | 926 | this_cpu_add(*net->core.sock_inuse, 1); |
f6f7d8cf | 927 | #endif |
2303f994 PK |
928 | err = tcp_set_ulp(sf->sk, "mptcp"); |
929 | release_sock(sf->sk); | |
930 | ||
931 | if (err) | |
932 | return err; | |
933 | ||
934 | subflow = mptcp_subflow_ctx(sf->sk); | |
935 | pr_debug("subflow=%p", subflow); | |
936 | ||
937 | *new_sock = sf; | |
79c0949e | 938 | sock_hold(sk); |
2303f994 PK |
939 | subflow->conn = sk; |
940 | ||
941 | return 0; | |
942 | } | |
943 | ||
944 | static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, | |
945 | gfp_t priority) | |
946 | { | |
947 | struct inet_connection_sock *icsk = inet_csk(sk); | |
948 | struct mptcp_subflow_context *ctx; | |
949 | ||
950 | ctx = kzalloc(sizeof(*ctx), priority); | |
951 | if (!ctx) | |
952 | return NULL; | |
953 | ||
954 | rcu_assign_pointer(icsk->icsk_ulp_data, ctx); | |
cec37a6e | 955 | INIT_LIST_HEAD(&ctx->node); |
2303f994 PK |
956 | |
957 | pr_debug("subflow=%p", ctx); | |
958 | ||
959 | ctx->tcp_sock = sk; | |
960 | ||
961 | return ctx; | |
962 | } | |
963 | ||
648ef4b8 MM |
964 | static void __subflow_state_change(struct sock *sk) |
965 | { | |
966 | struct socket_wq *wq; | |
967 | ||
968 | rcu_read_lock(); | |
969 | wq = rcu_dereference(sk->sk_wq); | |
970 | if (skwq_has_sleeper(wq)) | |
971 | wake_up_interruptible_all(&wq->wait); | |
972 | rcu_read_unlock(); | |
973 | } | |
974 | ||
975 | static bool subflow_is_done(const struct sock *sk) | |
976 | { | |
977 | return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE; | |
978 | } | |
979 | ||
980 | static void subflow_state_change(struct sock *sk) | |
981 | { | |
982 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
dc093db5 | 983 | struct sock *parent = subflow->conn; |
648ef4b8 MM |
984 | |
985 | __subflow_state_change(sk); | |
986 | ||
987 | /* as recvmsg() does not acquire the subflow socket for ssk selection | |
988 | * a fin packet carrying a DSS can be unnoticed if we don't trigger | |
989 | * the data available machinery here. | |
990 | */ | |
dc093db5 | 991 | if (subflow->mp_capable && mptcp_subflow_data_available(sk)) |
2e52213c | 992 | mptcp_data_ready(parent, sk); |
648ef4b8 | 993 | |
dc093db5 | 994 | if (!(parent->sk_shutdown & RCV_SHUTDOWN) && |
648ef4b8 MM |
995 | !subflow->rx_eof && subflow_is_done(sk)) { |
996 | subflow->rx_eof = 1; | |
59832e24 | 997 | mptcp_subflow_eof(parent); |
648ef4b8 MM |
998 | } |
999 | } | |
1000 | ||
2303f994 PK |
1001 | static int subflow_ulp_init(struct sock *sk) |
1002 | { | |
cec37a6e | 1003 | struct inet_connection_sock *icsk = inet_csk(sk); |
2303f994 PK |
1004 | struct mptcp_subflow_context *ctx; |
1005 | struct tcp_sock *tp = tcp_sk(sk); | |
1006 | int err = 0; | |
1007 | ||
1008 | /* disallow attaching ULP to a socket unless it has been | |
1009 | * created with sock_create_kern() | |
1010 | */ | |
1011 | if (!sk->sk_kern_sock) { | |
1012 | err = -EOPNOTSUPP; | |
1013 | goto out; | |
1014 | } | |
1015 | ||
1016 | ctx = subflow_create_ctx(sk, GFP_KERNEL); | |
1017 | if (!ctx) { | |
1018 | err = -ENOMEM; | |
1019 | goto out; | |
1020 | } | |
1021 | ||
1022 | pr_debug("subflow=%p, family=%d", ctx, sk->sk_family); | |
1023 | ||
1024 | tp->is_mptcp = 1; | |
cec37a6e PK |
1025 | ctx->icsk_af_ops = icsk->icsk_af_ops; |
1026 | icsk->icsk_af_ops = subflow_default_af_ops(sk); | |
648ef4b8 MM |
1027 | ctx->tcp_data_ready = sk->sk_data_ready; |
1028 | ctx->tcp_state_change = sk->sk_state_change; | |
1029 | ctx->tcp_write_space = sk->sk_write_space; | |
1030 | sk->sk_data_ready = subflow_data_ready; | |
1031 | sk->sk_write_space = subflow_write_space; | |
1032 | sk->sk_state_change = subflow_state_change; | |
2303f994 PK |
1033 | out: |
1034 | return err; | |
1035 | } | |
1036 | ||
1037 | static void subflow_ulp_release(struct sock *sk) | |
1038 | { | |
1039 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(sk); | |
1040 | ||
1041 | if (!ctx) | |
1042 | return; | |
1043 | ||
79c0949e PK |
1044 | if (ctx->conn) |
1045 | sock_put(ctx->conn); | |
1046 | ||
2303f994 PK |
1047 | kfree_rcu(ctx, rcu); |
1048 | } | |
1049 | ||
648ef4b8 MM |
1050 | static void subflow_ulp_fallback(struct sock *sk, |
1051 | struct mptcp_subflow_context *old_ctx) | |
cec37a6e PK |
1052 | { |
1053 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1054 | ||
648ef4b8 | 1055 | mptcp_subflow_tcp_fallback(sk, old_ctx); |
cec37a6e PK |
1056 | icsk->icsk_ulp_ops = NULL; |
1057 | rcu_assign_pointer(icsk->icsk_ulp_data, NULL); | |
1058 | tcp_sk(sk)->is_mptcp = 0; | |
1059 | } | |
1060 | ||
1061 | static void subflow_ulp_clone(const struct request_sock *req, | |
1062 | struct sock *newsk, | |
1063 | const gfp_t priority) | |
1064 | { | |
1065 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
1066 | struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk); | |
1067 | struct mptcp_subflow_context *new_ctx; | |
1068 | ||
f296234c PK |
1069 | if (!tcp_rsk(req)->is_mptcp || |
1070 | (!subflow_req->mp_capable && !subflow_req->mp_join)) { | |
648ef4b8 | 1071 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1072 | return; |
1073 | } | |
1074 | ||
1075 | new_ctx = subflow_create_ctx(newsk, priority); | |
edc7e489 | 1076 | if (!new_ctx) { |
648ef4b8 | 1077 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1078 | return; |
1079 | } | |
1080 | ||
1081 | new_ctx->conn_finished = 1; | |
1082 | new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; | |
648ef4b8 MM |
1083 | new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; |
1084 | new_ctx->tcp_state_change = old_ctx->tcp_state_change; | |
1085 | new_ctx->tcp_write_space = old_ctx->tcp_write_space; | |
58b09919 PA |
1086 | new_ctx->rel_write_seq = 1; |
1087 | new_ctx->tcp_sock = newsk; | |
1088 | ||
f296234c PK |
1089 | if (subflow_req->mp_capable) { |
1090 | /* see comments in subflow_syn_recv_sock(), MPTCP connection | |
1091 | * is fully established only after we receive the remote key | |
1092 | */ | |
1093 | new_ctx->mp_capable = 1; | |
1094 | new_ctx->fully_established = subflow_req->remote_key_valid; | |
1095 | new_ctx->can_ack = subflow_req->remote_key_valid; | |
1096 | new_ctx->remote_key = subflow_req->remote_key; | |
1097 | new_ctx->local_key = subflow_req->local_key; | |
1098 | new_ctx->token = subflow_req->token; | |
1099 | new_ctx->ssn_offset = subflow_req->ssn_offset; | |
1100 | new_ctx->idsn = subflow_req->idsn; | |
1101 | } else if (subflow_req->mp_join) { | |
ec3edaa7 | 1102 | new_ctx->ssn_offset = subflow_req->ssn_offset; |
f296234c PK |
1103 | new_ctx->mp_join = 1; |
1104 | new_ctx->fully_established = 1; | |
1105 | new_ctx->backup = subflow_req->backup; | |
1106 | new_ctx->local_id = subflow_req->local_id; | |
1107 | new_ctx->token = subflow_req->token; | |
1108 | new_ctx->thmac = subflow_req->thmac; | |
1109 | } | |
cec37a6e PK |
1110 | } |
1111 | ||
2303f994 PK |
1112 | static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { |
1113 | .name = "mptcp", | |
1114 | .owner = THIS_MODULE, | |
1115 | .init = subflow_ulp_init, | |
1116 | .release = subflow_ulp_release, | |
cec37a6e | 1117 | .clone = subflow_ulp_clone, |
2303f994 PK |
1118 | }; |
1119 | ||
cec37a6e PK |
1120 | static int subflow_ops_init(struct request_sock_ops *subflow_ops) |
1121 | { | |
1122 | subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock); | |
1123 | subflow_ops->slab_name = "request_sock_subflow"; | |
1124 | ||
1125 | subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name, | |
1126 | subflow_ops->obj_size, 0, | |
1127 | SLAB_ACCOUNT | | |
1128 | SLAB_TYPESAFE_BY_RCU, | |
1129 | NULL); | |
1130 | if (!subflow_ops->slab) | |
1131 | return -ENOMEM; | |
1132 | ||
79c0949e PK |
1133 | subflow_ops->destructor = subflow_req_destructor; |
1134 | ||
cec37a6e PK |
1135 | return 0; |
1136 | } | |
1137 | ||
2303f994 PK |
1138 | void mptcp_subflow_init(void) |
1139 | { | |
cec37a6e PK |
1140 | subflow_request_sock_ops = tcp_request_sock_ops; |
1141 | if (subflow_ops_init(&subflow_request_sock_ops) != 0) | |
1142 | panic("MPTCP: failed to init subflow request sock ops\n"); | |
1143 | ||
1144 | subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops; | |
1145 | subflow_request_sock_ipv4_ops.init_req = subflow_v4_init_req; | |
1146 | ||
1147 | subflow_specific = ipv4_specific; | |
1148 | subflow_specific.conn_request = subflow_v4_conn_request; | |
1149 | subflow_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1150 | subflow_specific.sk_rx_dst_set = subflow_finish_connect; | |
79c0949e | 1151 | subflow_specific.rebuild_header = subflow_rebuild_header; |
cec37a6e PK |
1152 | |
1153 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1154 | subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; | |
1155 | subflow_request_sock_ipv6_ops.init_req = subflow_v6_init_req; | |
1156 | ||
1157 | subflow_v6_specific = ipv6_specific; | |
1158 | subflow_v6_specific.conn_request = subflow_v6_conn_request; | |
1159 | subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1160 | subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect; | |
79c0949e | 1161 | subflow_v6_specific.rebuild_header = subflow_rebuild_header; |
cec37a6e PK |
1162 | |
1163 | subflow_v6m_specific = subflow_v6_specific; | |
1164 | subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit; | |
1165 | subflow_v6m_specific.send_check = ipv4_specific.send_check; | |
1166 | subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; | |
1167 | subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; | |
1168 | subflow_v6m_specific.net_frag_header_len = 0; | |
1169 | #endif | |
1170 | ||
5147dfb5 DC |
1171 | mptcp_diag_subflow_init(&subflow_ulp_ops); |
1172 | ||
2303f994 PK |
1173 | if (tcp_register_ulp(&subflow_ulp_ops) != 0) |
1174 | panic("MPTCP: failed to register subflows to ULP\n"); | |
1175 | } |