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Commit | Line | Data |
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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> |
a24d22b2 | 13 | #include <crypto/sha2.h> |
2303f994 PK |
14 | #include <net/sock.h> |
15 | #include <net/inet_common.h> | |
16 | #include <net/inet_hashtables.h> | |
17 | #include <net/protocol.h> | |
18 | #include <net/tcp.h> | |
cec37a6e PK |
19 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
20 | #include <net/ip6_route.h> | |
21 | #endif | |
2303f994 | 22 | #include <net/mptcp.h> |
4596a2c1 | 23 | #include <uapi/linux/mptcp.h> |
2303f994 | 24 | #include "protocol.h" |
fc518953 FW |
25 | #include "mib.h" |
26 | ||
27 | static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, | |
28 | enum linux_mptcp_mib_field field) | |
29 | { | |
30 | MPTCP_INC_STATS(sock_net(req_to_sk(req)), field); | |
31 | } | |
2303f994 | 32 | |
79c0949e PK |
33 | static void subflow_req_destructor(struct request_sock *req) |
34 | { | |
35 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
36 | ||
37 | pr_debug("subflow_req=%p", subflow_req); | |
38 | ||
8fd4de12 PA |
39 | if (subflow_req->msk) |
40 | sock_put((struct sock *)subflow_req->msk); | |
41 | ||
2c5ebd00 | 42 | mptcp_token_destroy_request(req); |
79c0949e PK |
43 | tcp_request_sock_ops.destructor(req); |
44 | } | |
45 | ||
f296234c PK |
46 | static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2, |
47 | void *hmac) | |
48 | { | |
49 | u8 msg[8]; | |
50 | ||
51 | put_unaligned_be32(nonce1, &msg[0]); | |
52 | put_unaligned_be32(nonce2, &msg[4]); | |
53 | ||
54 | mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac); | |
55 | } | |
56 | ||
4cf8b7e4 PA |
57 | static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk) |
58 | { | |
59 | return mptcp_is_fully_established((void *)msk) && | |
60 | READ_ONCE(msk->pm.accept_subflow); | |
61 | } | |
62 | ||
f296234c | 63 | /* validate received token and create truncated hmac and nonce for SYN-ACK */ |
8fd4de12 PA |
64 | static struct mptcp_sock *subflow_token_join_request(struct request_sock *req, |
65 | const struct sk_buff *skb) | |
f296234c PK |
66 | { |
67 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
bd697222 | 68 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c PK |
69 | struct mptcp_sock *msk; |
70 | int local_id; | |
71 | ||
72 | msk = mptcp_token_get_sock(subflow_req->token); | |
73 | if (!msk) { | |
fc518953 | 74 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINNOTOKEN); |
8fd4de12 | 75 | return NULL; |
f296234c PK |
76 | } |
77 | ||
78 | local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); | |
79 | if (local_id < 0) { | |
80 | sock_put((struct sock *)msk); | |
8fd4de12 | 81 | return NULL; |
f296234c PK |
82 | } |
83 | subflow_req->local_id = local_id; | |
84 | ||
85 | get_random_bytes(&subflow_req->local_nonce, sizeof(u32)); | |
86 | ||
87 | subflow_generate_hmac(msk->local_key, msk->remote_key, | |
88 | subflow_req->local_nonce, | |
89 | subflow_req->remote_nonce, hmac); | |
90 | ||
91 | subflow_req->thmac = get_unaligned_be64(hmac); | |
8fd4de12 | 92 | return msk; |
f296234c PK |
93 | } |
94 | ||
3bdb45f8 | 95 | static void subflow_init_req(struct request_sock *req, const struct sock *sk_listener) |
cec37a6e | 96 | { |
cec37a6e | 97 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); |
cec37a6e PK |
98 | |
99 | subflow_req->mp_capable = 0; | |
f296234c | 100 | subflow_req->mp_join = 0; |
8fd4de12 | 101 | subflow_req->msk = NULL; |
2c5ebd00 | 102 | mptcp_token_init_request(req); |
78d8b7bc FW |
103 | } |
104 | ||
3ecfbe3e FW |
105 | /* Init mptcp request socket. |
106 | * | |
107 | * Returns an error code if a JOIN has failed and a TCP reset | |
108 | * should be sent. | |
109 | */ | |
3bdb45f8 PA |
110 | static int subflow_check_req(struct request_sock *req, |
111 | const struct sock *sk_listener, | |
112 | struct sk_buff *skb) | |
78d8b7bc FW |
113 | { |
114 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
115 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
116 | struct mptcp_options_received mp_opt; | |
78d8b7bc FW |
117 | |
118 | pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); | |
119 | ||
3bdb45f8 PA |
120 | #ifdef CONFIG_TCP_MD5SIG |
121 | /* no MPTCP if MD5SIG is enabled on this socket or we may run out of | |
122 | * TCP option space. | |
123 | */ | |
124 | if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) | |
125 | return -EINVAL; | |
126 | #endif | |
78d8b7bc FW |
127 | |
128 | mptcp_get_options(skb, &mp_opt); | |
129 | ||
cfde141e | 130 | if (mp_opt.mp_capable) { |
fc518953 FW |
131 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); |
132 | ||
cfde141e | 133 | if (mp_opt.mp_join) |
3ecfbe3e | 134 | return 0; |
cfde141e | 135 | } else if (mp_opt.mp_join) { |
fc518953 FW |
136 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); |
137 | } | |
f296234c | 138 | |
cfde141e | 139 | if (mp_opt.mp_capable && listener->request_mptcp) { |
535fb815 FW |
140 | int err, retries = 4; |
141 | ||
c83a47e5 | 142 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
535fb815 FW |
143 | again: |
144 | do { | |
145 | get_random_bytes(&subflow_req->local_key, sizeof(subflow_req->local_key)); | |
146 | } while (subflow_req->local_key == 0); | |
79c0949e | 147 | |
c83a47e5 FW |
148 | if (unlikely(req->syncookie)) { |
149 | mptcp_crypto_key_sha(subflow_req->local_key, | |
150 | &subflow_req->token, | |
151 | &subflow_req->idsn); | |
152 | if (mptcp_token_exists(subflow_req->token)) { | |
153 | if (retries-- > 0) | |
154 | goto again; | |
155 | } else { | |
156 | subflow_req->mp_capable = 1; | |
157 | } | |
3ecfbe3e | 158 | return 0; |
c83a47e5 FW |
159 | } |
160 | ||
79c0949e PK |
161 | err = mptcp_token_new_request(req); |
162 | if (err == 0) | |
163 | subflow_req->mp_capable = 1; | |
535fb815 FW |
164 | else if (retries-- > 0) |
165 | goto again; | |
79c0949e | 166 | |
cfde141e | 167 | } else if (mp_opt.mp_join && listener->request_mptcp) { |
ec3edaa7 | 168 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
f296234c | 169 | subflow_req->mp_join = 1; |
cfde141e PA |
170 | subflow_req->backup = mp_opt.backup; |
171 | subflow_req->remote_id = mp_opt.join_id; | |
172 | subflow_req->token = mp_opt.token; | |
173 | subflow_req->remote_nonce = mp_opt.nonce; | |
8fd4de12 | 174 | subflow_req->msk = subflow_token_join_request(req, skb); |
9466a1cc | 175 | |
3ecfbe3e FW |
176 | /* Can't fall back to TCP in this case. */ |
177 | if (!subflow_req->msk) | |
178 | return -EPERM; | |
179 | ||
180 | if (unlikely(req->syncookie)) { | |
9466a1cc FW |
181 | if (mptcp_can_accept_new_subflow(subflow_req->msk)) |
182 | subflow_init_req_cookie_join_save(subflow_req, skb); | |
183 | } | |
184 | ||
8fd4de12 PA |
185 | pr_debug("token=%u, remote_nonce=%u msk=%p", subflow_req->token, |
186 | subflow_req->remote_nonce, subflow_req->msk); | |
cec37a6e | 187 | } |
3ecfbe3e FW |
188 | |
189 | return 0; | |
cec37a6e PK |
190 | } |
191 | ||
c83a47e5 FW |
192 | int mptcp_subflow_init_cookie_req(struct request_sock *req, |
193 | const struct sock *sk_listener, | |
194 | struct sk_buff *skb) | |
195 | { | |
196 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
197 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
198 | struct mptcp_options_received mp_opt; | |
199 | int err; | |
200 | ||
3bdb45f8 | 201 | subflow_init_req(req, sk_listener); |
c83a47e5 FW |
202 | mptcp_get_options(skb, &mp_opt); |
203 | ||
204 | if (mp_opt.mp_capable && mp_opt.mp_join) | |
205 | return -EINVAL; | |
206 | ||
207 | if (mp_opt.mp_capable && listener->request_mptcp) { | |
208 | if (mp_opt.sndr_key == 0) | |
209 | return -EINVAL; | |
210 | ||
211 | subflow_req->local_key = mp_opt.rcvr_key; | |
212 | err = mptcp_token_new_request(req); | |
213 | if (err) | |
214 | return err; | |
215 | ||
216 | subflow_req->mp_capable = 1; | |
217 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
9466a1cc FW |
218 | } else if (mp_opt.mp_join && listener->request_mptcp) { |
219 | if (!mptcp_token_join_cookie_init_state(subflow_req, skb)) | |
220 | return -EINVAL; | |
221 | ||
222 | if (mptcp_can_accept_new_subflow(subflow_req->msk)) | |
223 | subflow_req->mp_join = 1; | |
224 | ||
225 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
c83a47e5 FW |
226 | } |
227 | ||
228 | return 0; | |
229 | } | |
230 | EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); | |
231 | ||
7ea851d1 FW |
232 | static struct dst_entry *subflow_v4_route_req(const struct sock *sk, |
233 | struct sk_buff *skb, | |
234 | struct flowi *fl, | |
235 | struct request_sock *req) | |
cec37a6e | 236 | { |
7ea851d1 | 237 | struct dst_entry *dst; |
3ecfbe3e | 238 | int err; |
7ea851d1 | 239 | |
cec37a6e | 240 | tcp_rsk(req)->is_mptcp = 1; |
3bdb45f8 | 241 | subflow_init_req(req, sk); |
cec37a6e | 242 | |
7ea851d1 FW |
243 | dst = tcp_request_sock_ipv4_ops.route_req(sk, skb, fl, req); |
244 | if (!dst) | |
245 | return NULL; | |
cec37a6e | 246 | |
3bdb45f8 | 247 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
248 | if (err == 0) |
249 | return dst; | |
cec37a6e | 250 | |
3ecfbe3e FW |
251 | dst_release(dst); |
252 | if (!req->syncookie) | |
253 | tcp_request_sock_ops.send_reset(sk, skb); | |
254 | return NULL; | |
cec37a6e PK |
255 | } |
256 | ||
257 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
7ea851d1 FW |
258 | static struct dst_entry *subflow_v6_route_req(const struct sock *sk, |
259 | struct sk_buff *skb, | |
260 | struct flowi *fl, | |
261 | struct request_sock *req) | |
cec37a6e | 262 | { |
7ea851d1 | 263 | struct dst_entry *dst; |
3ecfbe3e | 264 | int err; |
7ea851d1 | 265 | |
cec37a6e | 266 | tcp_rsk(req)->is_mptcp = 1; |
3bdb45f8 | 267 | subflow_init_req(req, sk); |
cec37a6e | 268 | |
7ea851d1 FW |
269 | dst = tcp_request_sock_ipv6_ops.route_req(sk, skb, fl, req); |
270 | if (!dst) | |
271 | return NULL; | |
cec37a6e | 272 | |
3bdb45f8 | 273 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
274 | if (err == 0) |
275 | return dst; | |
276 | ||
277 | dst_release(dst); | |
278 | if (!req->syncookie) | |
279 | tcp6_request_sock_ops.send_reset(sk, skb); | |
280 | return NULL; | |
cec37a6e PK |
281 | } |
282 | #endif | |
283 | ||
ec3edaa7 PK |
284 | /* validate received truncated hmac and create hmac for third ACK */ |
285 | static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) | |
286 | { | |
bd697222 | 287 | u8 hmac[SHA256_DIGEST_SIZE]; |
ec3edaa7 PK |
288 | u64 thmac; |
289 | ||
290 | subflow_generate_hmac(subflow->remote_key, subflow->local_key, | |
291 | subflow->remote_nonce, subflow->local_nonce, | |
292 | hmac); | |
293 | ||
294 | thmac = get_unaligned_be64(hmac); | |
295 | pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", | |
296 | subflow, subflow->token, | |
297 | (unsigned long long)thmac, | |
298 | (unsigned long long)subflow->thmac); | |
299 | ||
300 | return thmac == subflow->thmac; | |
301 | } | |
302 | ||
d5824847 PA |
303 | void mptcp_subflow_reset(struct sock *ssk) |
304 | { | |
0e4f35d7 PA |
305 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); |
306 | struct sock *sk = subflow->conn; | |
307 | ||
ab82e996 FW |
308 | /* must hold: tcp_done() could drop last reference on parent */ |
309 | sock_hold(sk); | |
310 | ||
d5824847 PA |
311 | tcp_set_state(ssk, TCP_CLOSE); |
312 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
313 | tcp_done(ssk); | |
0e4f35d7 PA |
314 | if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && |
315 | schedule_work(&mptcp_sk(sk)->work)) | |
ab82e996 FW |
316 | return; /* worker will put sk for us */ |
317 | ||
318 | sock_put(sk); | |
d5824847 PA |
319 | } |
320 | ||
cec37a6e PK |
321 | static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) |
322 | { | |
323 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cfde141e | 324 | struct mptcp_options_received mp_opt; |
c3c123d1 | 325 | struct sock *parent = subflow->conn; |
cec37a6e PK |
326 | |
327 | subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); | |
328 | ||
1200832c | 329 | if (inet_sk_state_load(parent) == TCP_SYN_SENT) { |
c3c123d1 DC |
330 | inet_sk_state_store(parent, TCP_ESTABLISHED); |
331 | parent->sk_state_change(parent); | |
332 | } | |
333 | ||
263e1201 PA |
334 | /* be sure no special action on any packet other than syn-ack */ |
335 | if (subflow->conn_finished) | |
336 | return; | |
337 | ||
b0977bb2 | 338 | subflow->rel_write_seq = 1; |
263e1201 | 339 | subflow->conn_finished = 1; |
e1ff9e82 DC |
340 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; |
341 | pr_debug("subflow=%p synack seq=%x", subflow, subflow->ssn_offset); | |
263e1201 | 342 | |
cfde141e | 343 | mptcp_get_options(skb, &mp_opt); |
fa25e815 PA |
344 | if (subflow->request_mptcp) { |
345 | if (!mp_opt.mp_capable) { | |
346 | MPTCP_INC_STATS(sock_net(sk), | |
347 | MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); | |
348 | mptcp_do_fallback(sk); | |
349 | pr_fallback(mptcp_sk(subflow->conn)); | |
350 | goto fallback; | |
351 | } | |
352 | ||
263e1201 PA |
353 | subflow->mp_capable = 1; |
354 | subflow->can_ack = 1; | |
cfde141e | 355 | subflow->remote_key = mp_opt.sndr_key; |
263e1201 PA |
356 | pr_debug("subflow=%p, remote_key=%llu", subflow, |
357 | subflow->remote_key); | |
fa25e815 PA |
358 | mptcp_finish_connect(sk); |
359 | } else if (subflow->request_join) { | |
360 | u8 hmac[SHA256_DIGEST_SIZE]; | |
361 | ||
362 | if (!mp_opt.mp_join) | |
363 | goto do_reset; | |
364 | ||
cfde141e PA |
365 | subflow->thmac = mp_opt.thmac; |
366 | subflow->remote_nonce = mp_opt.nonce; | |
263e1201 PA |
367 | pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, |
368 | subflow->thmac, subflow->remote_nonce); | |
263e1201 | 369 | |
ec3edaa7 | 370 | if (!subflow_thmac_valid(subflow)) { |
fc518953 | 371 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC); |
ec3edaa7 PK |
372 | goto do_reset; |
373 | } | |
374 | ||
375 | subflow_generate_hmac(subflow->local_key, subflow->remote_key, | |
376 | subflow->local_nonce, | |
377 | subflow->remote_nonce, | |
bd697222 | 378 | hmac); |
bd697222 | 379 | memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN); |
ec3edaa7 | 380 | |
ec3edaa7 PK |
381 | if (!mptcp_finish_join(sk)) |
382 | goto do_reset; | |
383 | ||
fa25e815 | 384 | subflow->mp_join = 1; |
fc518953 | 385 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); |
fa25e815 PA |
386 | } else if (mptcp_check_fallback(sk)) { |
387 | fallback: | |
388 | mptcp_rcv_space_init(mptcp_sk(parent), sk); | |
cec37a6e | 389 | } |
fa25e815 PA |
390 | return; |
391 | ||
392 | do_reset: | |
d5824847 | 393 | mptcp_subflow_reset(sk); |
cec37a6e PK |
394 | } |
395 | ||
08b8d080 FW |
396 | struct request_sock_ops mptcp_subflow_request_sock_ops; |
397 | EXPORT_SYMBOL_GPL(mptcp_subflow_request_sock_ops); | |
cec37a6e PK |
398 | static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops; |
399 | ||
400 | static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
401 | { | |
402 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
403 | ||
404 | pr_debug("subflow=%p", subflow); | |
405 | ||
406 | /* Never answer to SYNs sent to broadcast or multicast */ | |
407 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
408 | goto drop; | |
409 | ||
08b8d080 | 410 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
411 | &subflow_request_sock_ipv4_ops, |
412 | sk, skb); | |
413 | drop: | |
414 | tcp_listendrop(sk); | |
415 | return 0; | |
416 | } | |
417 | ||
418 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
419 | static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; | |
420 | static struct inet_connection_sock_af_ops subflow_v6_specific; | |
421 | static struct inet_connection_sock_af_ops subflow_v6m_specific; | |
422 | ||
423 | static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) | |
424 | { | |
425 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
426 | ||
427 | pr_debug("subflow=%p", subflow); | |
428 | ||
429 | if (skb->protocol == htons(ETH_P_IP)) | |
430 | return subflow_v4_conn_request(sk, skb); | |
431 | ||
432 | if (!ipv6_unicast_destination(skb)) | |
433 | goto drop; | |
434 | ||
a1d31087 JK |
435 | if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { |
436 | __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); | |
437 | return 0; | |
438 | } | |
439 | ||
08b8d080 | 440 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
441 | &subflow_request_sock_ipv6_ops, sk, skb); |
442 | ||
443 | drop: | |
444 | tcp_listendrop(sk); | |
445 | return 0; /* don't send reset */ | |
446 | } | |
447 | #endif | |
448 | ||
f296234c PK |
449 | /* validate hmac received in third ACK */ |
450 | static bool subflow_hmac_valid(const struct request_sock *req, | |
cfde141e | 451 | const struct mptcp_options_received *mp_opt) |
f296234c PK |
452 | { |
453 | const struct mptcp_subflow_request_sock *subflow_req; | |
bd697222 | 454 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c | 455 | struct mptcp_sock *msk; |
f296234c PK |
456 | |
457 | subflow_req = mptcp_subflow_rsk(req); | |
8fd4de12 | 458 | msk = subflow_req->msk; |
f296234c PK |
459 | if (!msk) |
460 | return false; | |
461 | ||
462 | subflow_generate_hmac(msk->remote_key, msk->local_key, | |
463 | subflow_req->remote_nonce, | |
464 | subflow_req->local_nonce, hmac); | |
465 | ||
8fd4de12 | 466 | return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN); |
f296234c PK |
467 | } |
468 | ||
df1036da FW |
469 | static void mptcp_sock_destruct(struct sock *sk) |
470 | { | |
471 | /* if new mptcp socket isn't accepted, it is free'd | |
472 | * from the tcp listener sockets request queue, linked | |
473 | * from req->sk. The tcp socket is released. | |
474 | * This calls the ULP release function which will | |
475 | * also remove the mptcp socket, via | |
476 | * sock_put(ctx->conn). | |
477 | * | |
7ee24926 PA |
478 | * Problem is that the mptcp socket will be in |
479 | * ESTABLISHED state and will not have the SOCK_DEAD flag. | |
df1036da FW |
480 | * Both result in warnings from inet_sock_destruct. |
481 | */ | |
c5ed41bc | 482 | if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { |
df1036da FW |
483 | sk->sk_state = TCP_CLOSE; |
484 | WARN_ON_ONCE(sk->sk_socket); | |
485 | sock_orphan(sk); | |
486 | } | |
487 | ||
5c8c1640 | 488 | mptcp_destroy_common(mptcp_sk(sk)); |
df1036da FW |
489 | inet_sock_destruct(sk); |
490 | } | |
491 | ||
9f5ca6a5 FW |
492 | static void mptcp_force_close(struct sock *sk) |
493 | { | |
494 | inet_sk_state_store(sk, TCP_CLOSE); | |
495 | sk_common_release(sk); | |
496 | } | |
497 | ||
4c8941de PA |
498 | static void subflow_ulp_fallback(struct sock *sk, |
499 | struct mptcp_subflow_context *old_ctx) | |
500 | { | |
501 | struct inet_connection_sock *icsk = inet_csk(sk); | |
502 | ||
503 | mptcp_subflow_tcp_fallback(sk, old_ctx); | |
504 | icsk->icsk_ulp_ops = NULL; | |
505 | rcu_assign_pointer(icsk->icsk_ulp_data, NULL); | |
506 | tcp_sk(sk)->is_mptcp = 0; | |
507 | } | |
508 | ||
39884604 PA |
509 | static void subflow_drop_ctx(struct sock *ssk) |
510 | { | |
511 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); | |
512 | ||
513 | if (!ctx) | |
514 | return; | |
515 | ||
516 | subflow_ulp_fallback(ssk, ctx); | |
517 | if (ctx->conn) | |
518 | sock_put(ctx->conn); | |
519 | ||
520 | kfree_rcu(ctx, rcu); | |
521 | } | |
522 | ||
b93df08c PA |
523 | void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, |
524 | struct mptcp_options_received *mp_opt) | |
525 | { | |
526 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
527 | ||
528 | subflow->remote_key = mp_opt->sndr_key; | |
529 | subflow->fully_established = 1; | |
530 | subflow->can_ack = 1; | |
531 | WRITE_ONCE(msk->fully_established, true); | |
532 | } | |
533 | ||
cec37a6e PK |
534 | static struct sock *subflow_syn_recv_sock(const struct sock *sk, |
535 | struct sk_buff *skb, | |
536 | struct request_sock *req, | |
537 | struct dst_entry *dst, | |
538 | struct request_sock *req_unhash, | |
539 | bool *own_req) | |
540 | { | |
541 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk); | |
cc7972ea | 542 | struct mptcp_subflow_request_sock *subflow_req; |
cfde141e | 543 | struct mptcp_options_received mp_opt; |
9e365ff5 | 544 | bool fallback, fallback_is_fatal; |
58b09919 | 545 | struct sock *new_msk = NULL; |
cec37a6e PK |
546 | struct sock *child; |
547 | ||
548 | pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); | |
549 | ||
9e365ff5 PA |
550 | /* After child creation we must look for 'mp_capable' even when options |
551 | * are not parsed | |
cfde141e PA |
552 | */ |
553 | mp_opt.mp_capable = 0; | |
9e365ff5 PA |
554 | |
555 | /* hopefully temporary handling for MP_JOIN+syncookie */ | |
556 | subflow_req = mptcp_subflow_rsk(req); | |
b7514694 | 557 | fallback_is_fatal = tcp_rsk(req)->is_mptcp && subflow_req->mp_join; |
9e365ff5 PA |
558 | fallback = !tcp_rsk(req)->is_mptcp; |
559 | if (fallback) | |
ae2dd716 FW |
560 | goto create_child; |
561 | ||
d22f4988 | 562 | /* if the sk is MP_CAPABLE, we try to fetch the client key */ |
cc7972ea | 563 | if (subflow_req->mp_capable) { |
ffcc3365 PA |
564 | /* we can receive and accept an in-window, out-of-order pkt, |
565 | * which may not carry the MP_CAPABLE opt even on mptcp enabled | |
566 | * paths: always try to extract the peer key, and fallback | |
567 | * for packets missing it. | |
568 | * Even OoO DSS packets coming legitly after dropped or | |
569 | * reordered MPC will cause fallback, but we don't have other | |
570 | * options. | |
571 | */ | |
cfde141e PA |
572 | mptcp_get_options(skb, &mp_opt); |
573 | if (!mp_opt.mp_capable) { | |
4c8941de | 574 | fallback = true; |
58b09919 | 575 | goto create_child; |
d22f4988 | 576 | } |
58b09919 | 577 | |
cfde141e | 578 | new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); |
58b09919 | 579 | if (!new_msk) |
4c8941de | 580 | fallback = true; |
f296234c | 581 | } else if (subflow_req->mp_join) { |
cfde141e | 582 | mptcp_get_options(skb, &mp_opt); |
d3ab7885 PA |
583 | if (!mp_opt.mp_join || !subflow_hmac_valid(req, &mp_opt) || |
584 | !mptcp_can_accept_new_subflow(subflow_req->msk)) { | |
fc518953 | 585 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); |
9e365ff5 | 586 | fallback = true; |
fc518953 | 587 | } |
cc7972ea | 588 | } |
cec37a6e | 589 | |
d22f4988 | 590 | create_child: |
cec37a6e PK |
591 | child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, |
592 | req_unhash, own_req); | |
593 | ||
594 | if (child && *own_req) { | |
79c0949e PK |
595 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); |
596 | ||
90bf4513 PA |
597 | tcp_rsk(req)->drop_req = false; |
598 | ||
4c8941de PA |
599 | /* we need to fallback on ctx allocation failure and on pre-reqs |
600 | * checking above. In the latter scenario we additionally need | |
601 | * to reset the context to non MPTCP status. | |
79c0949e | 602 | */ |
4c8941de | 603 | if (!ctx || fallback) { |
f296234c | 604 | if (fallback_is_fatal) |
729cd643 | 605 | goto dispose_child; |
4c8941de | 606 | |
39884604 | 607 | subflow_drop_ctx(child); |
58b09919 | 608 | goto out; |
f296234c | 609 | } |
79c0949e PK |
610 | |
611 | if (ctx->mp_capable) { | |
b93df08c PA |
612 | /* this can't race with mptcp_close(), as the msk is |
613 | * not yet exposted to user-space | |
614 | */ | |
615 | inet_sk_state_store((void *)new_msk, TCP_ESTABLISHED); | |
616 | ||
5b950ff4 PA |
617 | /* record the newly created socket as the first msk |
618 | * subflow, but don't link it yet into conn_list | |
619 | */ | |
0397c6d8 PA |
620 | WRITE_ONCE(mptcp_sk(new_msk)->first, child); |
621 | ||
58b09919 PA |
622 | /* new mpc subflow takes ownership of the newly |
623 | * created mptcp socket | |
624 | */ | |
df1036da | 625 | new_msk->sk_destruct = mptcp_sock_destruct; |
1b1c7a0e | 626 | mptcp_pm_new_connection(mptcp_sk(new_msk), 1); |
2c5ebd00 | 627 | mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); |
58b09919 PA |
628 | ctx->conn = new_msk; |
629 | new_msk = NULL; | |
fca5c82c PA |
630 | |
631 | /* with OoO packets we can reach here without ingress | |
632 | * mpc option | |
633 | */ | |
b93df08c PA |
634 | if (mp_opt.mp_capable) |
635 | mptcp_subflow_fully_established(ctx, &mp_opt); | |
f296234c PK |
636 | } else if (ctx->mp_join) { |
637 | struct mptcp_sock *owner; | |
638 | ||
8fd4de12 | 639 | owner = subflow_req->msk; |
f296234c | 640 | if (!owner) |
729cd643 | 641 | goto dispose_child; |
f296234c | 642 | |
8fd4de12 PA |
643 | /* move the msk reference ownership to the subflow */ |
644 | subflow_req->msk = NULL; | |
f296234c PK |
645 | ctx->conn = (struct sock *)owner; |
646 | if (!mptcp_finish_join(child)) | |
729cd643 | 647 | goto dispose_child; |
fc518953 FW |
648 | |
649 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); | |
90bf4513 | 650 | tcp_rsk(req)->drop_req = true; |
cec37a6e PK |
651 | } |
652 | } | |
653 | ||
58b09919 PA |
654 | out: |
655 | /* dispose of the left over mptcp master, if any */ | |
656 | if (unlikely(new_msk)) | |
9f5ca6a5 | 657 | mptcp_force_close(new_msk); |
4c8941de PA |
658 | |
659 | /* check for expected invariant - should never trigger, just help | |
660 | * catching eariler subtle bugs | |
661 | */ | |
ac2b47fb | 662 | WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp && |
4c8941de PA |
663 | (!mptcp_subflow_ctx(child) || |
664 | !mptcp_subflow_ctx(child)->conn)); | |
cec37a6e | 665 | return child; |
f296234c | 666 | |
729cd643 | 667 | dispose_child: |
39884604 | 668 | subflow_drop_ctx(child); |
729cd643 | 669 | tcp_rsk(req)->drop_req = true; |
729cd643 | 670 | inet_csk_prepare_for_destroy_sock(child); |
f296234c | 671 | tcp_done(child); |
97e61751 | 672 | req->rsk_ops->send_reset(sk, skb); |
729cd643 PA |
673 | |
674 | /* The last child reference will be released by the caller */ | |
675 | return child; | |
cec37a6e PK |
676 | } |
677 | ||
678 | static struct inet_connection_sock_af_ops subflow_specific; | |
679 | ||
648ef4b8 MM |
680 | enum mapping_status { |
681 | MAPPING_OK, | |
682 | MAPPING_INVALID, | |
683 | MAPPING_EMPTY, | |
e1ff9e82 DC |
684 | MAPPING_DATA_FIN, |
685 | MAPPING_DUMMY | |
648ef4b8 MM |
686 | }; |
687 | ||
688 | static u64 expand_seq(u64 old_seq, u16 old_data_len, u64 seq) | |
689 | { | |
690 | if ((u32)seq == (u32)old_seq) | |
691 | return old_seq; | |
692 | ||
693 | /* Assume map covers data not mapped yet. */ | |
694 | return seq | ((old_seq + old_data_len + 1) & GENMASK_ULL(63, 32)); | |
695 | } | |
696 | ||
697 | static void warn_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) | |
698 | { | |
699 | WARN_ONCE(1, "Bad mapping: ssn=%d map_seq=%d map_data_len=%d", | |
700 | ssn, subflow->map_subflow_seq, subflow->map_data_len); | |
701 | } | |
702 | ||
703 | static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) | |
704 | { | |
705 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
706 | unsigned int skb_consumed; | |
707 | ||
708 | skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; | |
709 | if (WARN_ON_ONCE(skb_consumed >= skb->len)) | |
710 | return true; | |
711 | ||
712 | return skb->len - skb_consumed <= subflow->map_data_len - | |
713 | mptcp_subflow_get_map_offset(subflow); | |
714 | } | |
715 | ||
716 | static bool validate_mapping(struct sock *ssk, struct sk_buff *skb) | |
717 | { | |
718 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
719 | u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
720 | ||
721 | if (unlikely(before(ssn, subflow->map_subflow_seq))) { | |
722 | /* Mapping covers data later in the subflow stream, | |
723 | * currently unsupported. | |
724 | */ | |
725 | warn_bad_map(subflow, ssn); | |
726 | return false; | |
727 | } | |
728 | if (unlikely(!before(ssn, subflow->map_subflow_seq + | |
729 | subflow->map_data_len))) { | |
730 | /* Mapping does covers past subflow data, invalid */ | |
731 | warn_bad_map(subflow, ssn + skb->len); | |
732 | return false; | |
733 | } | |
734 | return true; | |
735 | } | |
736 | ||
43b54c6e MM |
737 | static enum mapping_status get_mapping_status(struct sock *ssk, |
738 | struct mptcp_sock *msk) | |
648ef4b8 MM |
739 | { |
740 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
741 | struct mptcp_ext *mpext; | |
742 | struct sk_buff *skb; | |
743 | u16 data_len; | |
744 | u64 map_seq; | |
745 | ||
746 | skb = skb_peek(&ssk->sk_receive_queue); | |
747 | if (!skb) | |
748 | return MAPPING_EMPTY; | |
749 | ||
e1ff9e82 DC |
750 | if (mptcp_check_fallback(ssk)) |
751 | return MAPPING_DUMMY; | |
752 | ||
648ef4b8 MM |
753 | mpext = mptcp_get_ext(skb); |
754 | if (!mpext || !mpext->use_map) { | |
755 | if (!subflow->map_valid && !skb->len) { | |
756 | /* the TCP stack deliver 0 len FIN pkt to the receive | |
757 | * queue, that is the only 0len pkts ever expected here, | |
758 | * and we can admit no mapping only for 0 len pkts | |
759 | */ | |
760 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) | |
761 | WARN_ONCE(1, "0len seq %d:%d flags %x", | |
762 | TCP_SKB_CB(skb)->seq, | |
763 | TCP_SKB_CB(skb)->end_seq, | |
764 | TCP_SKB_CB(skb)->tcp_flags); | |
765 | sk_eat_skb(ssk, skb); | |
766 | return MAPPING_EMPTY; | |
767 | } | |
768 | ||
769 | if (!subflow->map_valid) | |
770 | return MAPPING_INVALID; | |
771 | ||
772 | goto validate_seq; | |
773 | } | |
774 | ||
775 | pr_debug("seq=%llu is64=%d ssn=%u data_len=%u data_fin=%d", | |
776 | mpext->data_seq, mpext->dsn64, mpext->subflow_seq, | |
777 | mpext->data_len, mpext->data_fin); | |
778 | ||
779 | data_len = mpext->data_len; | |
780 | if (data_len == 0) { | |
fc518953 | 781 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); |
648ef4b8 MM |
782 | return MAPPING_INVALID; |
783 | } | |
784 | ||
785 | if (mpext->data_fin == 1) { | |
786 | if (data_len == 1) { | |
1a49b2c2 MM |
787 | bool updated = mptcp_update_rcv_data_fin(msk, mpext->data_seq, |
788 | mpext->dsn64); | |
43b54c6e | 789 | pr_debug("DATA_FIN with no payload seq=%llu", mpext->data_seq); |
648ef4b8 MM |
790 | if (subflow->map_valid) { |
791 | /* A DATA_FIN might arrive in a DSS | |
792 | * option before the previous mapping | |
793 | * has been fully consumed. Continue | |
794 | * handling the existing mapping. | |
795 | */ | |
796 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
797 | return MAPPING_OK; | |
798 | } else { | |
ef59b195 MM |
799 | if (updated && schedule_work(&msk->work)) |
800 | sock_hold((struct sock *)msk); | |
801 | ||
648ef4b8 MM |
802 | return MAPPING_DATA_FIN; |
803 | } | |
43b54c6e | 804 | } else { |
017512a0 | 805 | u64 data_fin_seq = mpext->data_seq + data_len - 1; |
1a49b2c2 MM |
806 | |
807 | /* If mpext->data_seq is a 32-bit value, data_fin_seq | |
808 | * must also be limited to 32 bits. | |
809 | */ | |
810 | if (!mpext->dsn64) | |
811 | data_fin_seq &= GENMASK_ULL(31, 0); | |
812 | ||
813 | mptcp_update_rcv_data_fin(msk, data_fin_seq, mpext->dsn64); | |
814 | pr_debug("DATA_FIN with mapping seq=%llu dsn64=%d", | |
815 | data_fin_seq, mpext->dsn64); | |
648ef4b8 MM |
816 | } |
817 | ||
818 | /* Adjust for DATA_FIN using 1 byte of sequence space */ | |
819 | data_len--; | |
820 | } | |
821 | ||
822 | if (!mpext->dsn64) { | |
823 | map_seq = expand_seq(subflow->map_seq, subflow->map_data_len, | |
824 | mpext->data_seq); | |
825 | pr_debug("expanded seq=%llu", subflow->map_seq); | |
826 | } else { | |
827 | map_seq = mpext->data_seq; | |
828 | } | |
37198e93 | 829 | WRITE_ONCE(mptcp_sk(subflow->conn)->use_64bit_ack, !!mpext->dsn64); |
648ef4b8 MM |
830 | |
831 | if (subflow->map_valid) { | |
832 | /* Allow replacing only with an identical map */ | |
833 | if (subflow->map_seq == map_seq && | |
834 | subflow->map_subflow_seq == mpext->subflow_seq && | |
835 | subflow->map_data_len == data_len) { | |
836 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
837 | return MAPPING_OK; | |
838 | } | |
839 | ||
840 | /* If this skb data are fully covered by the current mapping, | |
841 | * the new map would need caching, which is not supported | |
842 | */ | |
fc518953 FW |
843 | if (skb_is_fully_mapped(ssk, skb)) { |
844 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH); | |
648ef4b8 | 845 | return MAPPING_INVALID; |
fc518953 | 846 | } |
648ef4b8 MM |
847 | |
848 | /* will validate the next map after consuming the current one */ | |
849 | return MAPPING_OK; | |
850 | } | |
851 | ||
852 | subflow->map_seq = map_seq; | |
853 | subflow->map_subflow_seq = mpext->subflow_seq; | |
854 | subflow->map_data_len = data_len; | |
855 | subflow->map_valid = 1; | |
d22f4988 | 856 | subflow->mpc_map = mpext->mpc_map; |
648ef4b8 MM |
857 | pr_debug("new map seq=%llu subflow_seq=%u data_len=%u", |
858 | subflow->map_seq, subflow->map_subflow_seq, | |
859 | subflow->map_data_len); | |
860 | ||
861 | validate_seq: | |
862 | /* we revalidate valid mapping on new skb, because we must ensure | |
863 | * the current skb is completely covered by the available mapping | |
864 | */ | |
865 | if (!validate_mapping(ssk, skb)) | |
866 | return MAPPING_INVALID; | |
867 | ||
868 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
869 | return MAPPING_OK; | |
870 | } | |
871 | ||
04e4cd4f | 872 | static void mptcp_subflow_discard_data(struct sock *ssk, struct sk_buff *skb, |
1d39cd8c | 873 | u64 limit) |
6719331c PA |
874 | { |
875 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
04e4cd4f PA |
876 | bool fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; |
877 | u32 incr; | |
878 | ||
879 | incr = limit >= skb->len ? skb->len + fin : limit; | |
880 | ||
881 | pr_debug("discarding=%d len=%d seq=%d", incr, skb->len, | |
882 | subflow->map_subflow_seq); | |
06242e44 | 883 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DUPDATA); |
04e4cd4f PA |
884 | tcp_sk(ssk)->copied_seq += incr; |
885 | if (!before(tcp_sk(ssk)->copied_seq, TCP_SKB_CB(skb)->end_seq)) | |
886 | sk_eat_skb(ssk, skb); | |
887 | if (mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) | |
888 | subflow->map_valid = 0; | |
6719331c PA |
889 | } |
890 | ||
648ef4b8 MM |
891 | static bool subflow_check_data_avail(struct sock *ssk) |
892 | { | |
893 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
894 | enum mapping_status status; | |
895 | struct mptcp_sock *msk; | |
896 | struct sk_buff *skb; | |
897 | ||
898 | pr_debug("msk=%p ssk=%p data_avail=%d skb=%p", subflow->conn, ssk, | |
899 | subflow->data_avail, skb_peek(&ssk->sk_receive_queue)); | |
47bebdf3 PA |
900 | if (!skb_peek(&ssk->sk_receive_queue)) |
901 | subflow->data_avail = 0; | |
648ef4b8 MM |
902 | if (subflow->data_avail) |
903 | return true; | |
904 | ||
648ef4b8 MM |
905 | msk = mptcp_sk(subflow->conn); |
906 | for (;;) { | |
648ef4b8 MM |
907 | u64 ack_seq; |
908 | u64 old_ack; | |
909 | ||
43b54c6e | 910 | status = get_mapping_status(ssk, msk); |
e86f3f3c PA |
911 | if (unlikely(status == MAPPING_INVALID)) |
912 | goto fallback; | |
913 | ||
914 | if (unlikely(status == MAPPING_DUMMY)) | |
915 | goto fallback; | |
648ef4b8 MM |
916 | |
917 | if (status != MAPPING_OK) | |
918 | return false; | |
919 | ||
920 | skb = skb_peek(&ssk->sk_receive_queue); | |
921 | if (WARN_ON_ONCE(!skb)) | |
922 | return false; | |
923 | ||
d22f4988 CP |
924 | /* if msk lacks the remote key, this subflow must provide an |
925 | * MP_CAPABLE-based mapping | |
926 | */ | |
927 | if (unlikely(!READ_ONCE(msk->can_ack))) { | |
e86f3f3c PA |
928 | if (!subflow->mpc_map) |
929 | goto fallback; | |
d22f4988 CP |
930 | WRITE_ONCE(msk->remote_key, subflow->remote_key); |
931 | WRITE_ONCE(msk->ack_seq, subflow->map_seq); | |
932 | WRITE_ONCE(msk->can_ack, true); | |
933 | } | |
934 | ||
648ef4b8 MM |
935 | old_ack = READ_ONCE(msk->ack_seq); |
936 | ack_seq = mptcp_subflow_get_mapped_dsn(subflow); | |
937 | pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, | |
938 | ack_seq); | |
47bebdf3 | 939 | if (ack_seq == old_ack) { |
6719331c PA |
940 | subflow->data_avail = MPTCP_SUBFLOW_DATA_AVAIL; |
941 | break; | |
942 | } else if (after64(ack_seq, old_ack)) { | |
943 | subflow->data_avail = MPTCP_SUBFLOW_OOO_DATA; | |
648ef4b8 | 944 | break; |
47bebdf3 | 945 | } |
648ef4b8 MM |
946 | |
947 | /* only accept in-sequence mapping. Old values are spurious | |
6719331c | 948 | * retransmission |
648ef4b8 | 949 | */ |
04e4cd4f | 950 | mptcp_subflow_discard_data(ssk, skb, old_ack - ack_seq); |
648ef4b8 MM |
951 | } |
952 | return true; | |
953 | ||
e86f3f3c PA |
954 | fallback: |
955 | /* RFC 8684 section 3.7. */ | |
956 | if (subflow->mp_join || subflow->fully_established) { | |
957 | /* fatal protocol error, close the socket. | |
958 | * subflow_error_report() will introduce the appropriate barriers | |
959 | */ | |
960 | ssk->sk_err = EBADMSG; | |
961 | ssk->sk_error_report(ssk); | |
962 | tcp_set_state(ssk, TCP_CLOSE); | |
963 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
964 | subflow->data_avail = 0; | |
965 | return false; | |
966 | } | |
967 | ||
968 | __mptcp_do_fallback(msk); | |
969 | skb = skb_peek(&ssk->sk_receive_queue); | |
970 | subflow->map_valid = 1; | |
971 | subflow->map_seq = READ_ONCE(msk->ack_seq); | |
972 | subflow->map_data_len = skb->len; | |
973 | subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
974 | subflow->data_avail = MPTCP_SUBFLOW_DATA_AVAIL; | |
975 | return true; | |
648ef4b8 MM |
976 | } |
977 | ||
978 | bool mptcp_subflow_data_available(struct sock *sk) | |
979 | { | |
980 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
648ef4b8 MM |
981 | |
982 | /* check if current mapping is still valid */ | |
983 | if (subflow->map_valid && | |
984 | mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) { | |
985 | subflow->map_valid = 0; | |
986 | subflow->data_avail = 0; | |
987 | ||
988 | pr_debug("Done with mapping: seq=%u data_len=%u", | |
989 | subflow->map_subflow_seq, | |
990 | subflow->map_data_len); | |
991 | } | |
992 | ||
47bebdf3 | 993 | return subflow_check_data_avail(sk); |
648ef4b8 MM |
994 | } |
995 | ||
071c8ed6 FW |
996 | /* If ssk has an mptcp parent socket, use the mptcp rcvbuf occupancy, |
997 | * not the ssk one. | |
998 | * | |
999 | * In mptcp, rwin is about the mptcp-level connection data. | |
1000 | * | |
1001 | * Data that is still on the ssk rx queue can thus be ignored, | |
1002 | * as far as mptcp peer is concerened that data is still inflight. | |
1003 | * DSS ACK is updated when skb is moved to the mptcp rx queue. | |
1004 | */ | |
1005 | void mptcp_space(const struct sock *ssk, int *space, int *full_space) | |
1006 | { | |
1007 | const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1008 | const struct sock *sk = subflow->conn; | |
1009 | ||
ea4ca586 | 1010 | *space = __mptcp_space(sk); |
071c8ed6 FW |
1011 | *full_space = tcp_full_space(sk); |
1012 | } | |
1013 | ||
648ef4b8 MM |
1014 | static void subflow_data_ready(struct sock *sk) |
1015 | { | |
1016 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
8c728940 | 1017 | u16 state = 1 << inet_sk_state_load(sk); |
648ef4b8 | 1018 | struct sock *parent = subflow->conn; |
e1ff9e82 | 1019 | struct mptcp_sock *msk; |
648ef4b8 | 1020 | |
e1ff9e82 | 1021 | msk = mptcp_sk(parent); |
8c728940 | 1022 | if (state & TCPF_LISTEN) { |
36811acc PA |
1023 | /* MPJ subflow are removed from accept queue before reaching here, |
1024 | * avoid stray wakeups | |
1025 | */ | |
1026 | if (reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue)) | |
1027 | return; | |
1028 | ||
e1ff9e82 | 1029 | set_bit(MPTCP_DATA_READY, &msk->flags); |
dc093db5 | 1030 | parent->sk_data_ready(parent); |
648ef4b8 MM |
1031 | return; |
1032 | } | |
1033 | ||
e1ff9e82 | 1034 | WARN_ON_ONCE(!__mptcp_check_fallback(msk) && !subflow->mp_capable && |
8c728940 | 1035 | !subflow->mp_join && !(state & TCPF_CLOSE)); |
e1ff9e82 | 1036 | |
101f6f85 | 1037 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 1038 | mptcp_data_ready(parent, sk); |
648ef4b8 MM |
1039 | } |
1040 | ||
6e628cd3 | 1041 | static void subflow_write_space(struct sock *ssk) |
648ef4b8 | 1042 | { |
6e628cd3 | 1043 | /* we take action in __mptcp_clean_una() */ |
648ef4b8 MM |
1044 | } |
1045 | ||
a5b31c47 PA |
1046 | void __mptcp_error_report(struct sock *sk) |
1047 | { | |
1048 | struct mptcp_subflow_context *subflow; | |
1049 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1050 | ||
1051 | mptcp_for_each_subflow(msk, subflow) { | |
1052 | struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | |
1053 | int err = sock_error(ssk); | |
1054 | ||
1055 | if (!err) | |
1056 | continue; | |
1057 | ||
1058 | /* only propagate errors on fallen-back sockets or | |
1059 | * on MPC connect | |
1060 | */ | |
1061 | if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(msk)) | |
1062 | continue; | |
1063 | ||
1064 | inet_sk_state_store(sk, inet_sk_state_load(ssk)); | |
1065 | sk->sk_err = -err; | |
1066 | ||
1067 | /* This barrier is coupled with smp_rmb() in mptcp_poll() */ | |
1068 | smp_wmb(); | |
1069 | sk->sk_error_report(sk); | |
1070 | break; | |
1071 | } | |
1072 | } | |
1073 | ||
1074 | static void subflow_error_report(struct sock *ssk) | |
1075 | { | |
1076 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1077 | ||
1078 | mptcp_data_lock(sk); | |
1079 | if (!sock_owned_by_user(sk)) | |
1080 | __mptcp_error_report(sk); | |
1081 | else | |
1082 | set_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags); | |
1083 | mptcp_data_unlock(sk); | |
1084 | } | |
1085 | ||
cec37a6e PK |
1086 | static struct inet_connection_sock_af_ops * |
1087 | subflow_default_af_ops(struct sock *sk) | |
1088 | { | |
1089 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1090 | if (sk->sk_family == AF_INET6) | |
1091 | return &subflow_v6_specific; | |
1092 | #endif | |
1093 | return &subflow_specific; | |
1094 | } | |
1095 | ||
cec37a6e | 1096 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
31484d56 GU |
1097 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped) |
1098 | { | |
cec37a6e PK |
1099 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1100 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1101 | struct inet_connection_sock_af_ops *target; | |
1102 | ||
1103 | target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk); | |
1104 | ||
1105 | pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d", | |
edc7e489 | 1106 | subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped); |
cec37a6e PK |
1107 | |
1108 | if (likely(icsk->icsk_af_ops == target)) | |
1109 | return; | |
1110 | ||
1111 | subflow->icsk_af_ops = icsk->icsk_af_ops; | |
1112 | icsk->icsk_af_ops = target; | |
cec37a6e | 1113 | } |
31484d56 | 1114 | #endif |
cec37a6e | 1115 | |
ec3edaa7 PK |
1116 | static void mptcp_info2sockaddr(const struct mptcp_addr_info *info, |
1117 | struct sockaddr_storage *addr) | |
1118 | { | |
1119 | memset(addr, 0, sizeof(*addr)); | |
1120 | addr->ss_family = info->family; | |
1121 | if (addr->ss_family == AF_INET) { | |
1122 | struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; | |
1123 | ||
1124 | in_addr->sin_addr = info->addr; | |
1125 | in_addr->sin_port = info->port; | |
1126 | } | |
1127 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1128 | else if (addr->ss_family == AF_INET6) { | |
1129 | struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; | |
1130 | ||
1131 | in6_addr->sin6_addr = info->addr6; | |
1132 | in6_addr->sin6_port = info->port; | |
1133 | } | |
1134 | #endif | |
1135 | } | |
1136 | ||
ef0da3b8 | 1137 | int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, |
ec3edaa7 PK |
1138 | const struct mptcp_addr_info *remote) |
1139 | { | |
1140 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1141 | struct mptcp_subflow_context *subflow; | |
1142 | struct sockaddr_storage addr; | |
2ff0e566 | 1143 | int remote_id = remote->id; |
6bad912b | 1144 | int local_id = loc->id; |
ec3edaa7 | 1145 | struct socket *sf; |
6bad912b | 1146 | struct sock *ssk; |
ec3edaa7 PK |
1147 | u32 remote_token; |
1148 | int addrlen; | |
1149 | int err; | |
1150 | ||
b93df08c | 1151 | if (!mptcp_is_fully_established(sk)) |
ec3edaa7 PK |
1152 | return -ENOTCONN; |
1153 | ||
1154 | err = mptcp_subflow_create_socket(sk, &sf); | |
1155 | if (err) | |
1156 | return err; | |
1157 | ||
6bad912b PA |
1158 | ssk = sf->sk; |
1159 | subflow = mptcp_subflow_ctx(ssk); | |
1160 | do { | |
1161 | get_random_bytes(&subflow->local_nonce, sizeof(u32)); | |
1162 | } while (!subflow->local_nonce); | |
1163 | ||
1164 | if (!local_id) { | |
1165 | err = mptcp_pm_get_local_id(msk, (struct sock_common *)ssk); | |
1166 | if (err < 0) | |
1167 | goto failed; | |
1168 | ||
1169 | local_id = err; | |
1170 | } | |
1171 | ||
ec3edaa7 PK |
1172 | subflow->remote_key = msk->remote_key; |
1173 | subflow->local_key = msk->local_key; | |
1174 | subflow->token = msk->token; | |
1175 | mptcp_info2sockaddr(loc, &addr); | |
1176 | ||
1177 | addrlen = sizeof(struct sockaddr_in); | |
1178 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1179 | if (loc->family == AF_INET6) | |
1180 | addrlen = sizeof(struct sockaddr_in6); | |
1181 | #endif | |
ef0da3b8 | 1182 | ssk->sk_bound_dev_if = loc->ifindex; |
ec3edaa7 PK |
1183 | err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); |
1184 | if (err) | |
1185 | goto failed; | |
1186 | ||
1187 | mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); | |
2ff0e566 GT |
1188 | pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk, |
1189 | remote_token, local_id, remote_id); | |
ec3edaa7 | 1190 | subflow->remote_token = remote_token; |
6bad912b | 1191 | subflow->local_id = local_id; |
2ff0e566 | 1192 | subflow->remote_id = remote_id; |
ec3edaa7 | 1193 | subflow->request_join = 1; |
4596a2c1 | 1194 | subflow->request_bkup = !!(loc->flags & MPTCP_PM_ADDR_FLAG_BACKUP); |
ec3edaa7 PK |
1195 | mptcp_info2sockaddr(remote, &addr); |
1196 | ||
5b950ff4 | 1197 | mptcp_add_pending_subflow(msk, subflow); |
ec3edaa7 PK |
1198 | err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); |
1199 | if (err && err != -EINPROGRESS) | |
5b950ff4 | 1200 | goto failed_unlink; |
ec3edaa7 | 1201 | |
133f0169 PA |
1202 | /* discard the subflow socket */ |
1203 | mptcp_sock_graft(ssk, sk->sk_socket); | |
1204 | iput(SOCK_INODE(sf)); | |
ec3edaa7 PK |
1205 | return err; |
1206 | ||
5b950ff4 | 1207 | failed_unlink: |
ec3edaa7 | 1208 | spin_lock_bh(&msk->join_list_lock); |
5b950ff4 | 1209 | list_del(&subflow->node); |
ec3edaa7 | 1210 | spin_unlock_bh(&msk->join_list_lock); |
42093e32 | 1211 | sock_put(mptcp_subflow_tcp_sock(subflow)); |
ec3edaa7 | 1212 | |
ec3edaa7 | 1213 | failed: |
e16163b6 | 1214 | subflow->disposable = 1; |
ec3edaa7 PK |
1215 | sock_release(sf); |
1216 | return err; | |
1217 | } | |
1218 | ||
3764b0c5 NR |
1219 | static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) |
1220 | { | |
1221 | #ifdef CONFIG_SOCK_CGROUP_DATA | |
1222 | struct sock_cgroup_data *parent_skcd = &parent->sk_cgrp_data, | |
1223 | *child_skcd = &child->sk_cgrp_data; | |
1224 | ||
1225 | /* only the additional subflows created by kworkers have to be modified */ | |
1226 | if (cgroup_id(sock_cgroup_ptr(parent_skcd)) != | |
1227 | cgroup_id(sock_cgroup_ptr(child_skcd))) { | |
1228 | #ifdef CONFIG_MEMCG | |
1229 | struct mem_cgroup *memcg = parent->sk_memcg; | |
1230 | ||
1231 | mem_cgroup_sk_free(child); | |
1232 | if (memcg && css_tryget(&memcg->css)) | |
1233 | child->sk_memcg = memcg; | |
1234 | #endif /* CONFIG_MEMCG */ | |
1235 | ||
1236 | cgroup_sk_free(child_skcd); | |
1237 | *child_skcd = *parent_skcd; | |
1238 | cgroup_sk_clone(child_skcd); | |
1239 | } | |
1240 | #endif /* CONFIG_SOCK_CGROUP_DATA */ | |
1241 | } | |
1242 | ||
2303f994 PK |
1243 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) |
1244 | { | |
1245 | struct mptcp_subflow_context *subflow; | |
1246 | struct net *net = sock_net(sk); | |
1247 | struct socket *sf; | |
1248 | int err; | |
1249 | ||
adf73410 PA |
1250 | /* un-accepted server sockets can reach here - on bad configuration |
1251 | * bail early to avoid greater trouble later | |
1252 | */ | |
1253 | if (unlikely(!sk->sk_socket)) | |
1254 | return -EINVAL; | |
1255 | ||
cec37a6e PK |
1256 | err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP, |
1257 | &sf); | |
2303f994 PK |
1258 | if (err) |
1259 | return err; | |
1260 | ||
1261 | lock_sock(sf->sk); | |
1262 | ||
3764b0c5 NR |
1263 | /* the newly created socket has to be in the same cgroup as its parent */ |
1264 | mptcp_attach_cgroup(sk, sf->sk); | |
1265 | ||
2303f994 PK |
1266 | /* kernel sockets do not by default acquire net ref, but TCP timer |
1267 | * needs it. | |
1268 | */ | |
1269 | sf->sk->sk_net_refcnt = 1; | |
1270 | get_net(net); | |
f6f7d8cf | 1271 | #ifdef CONFIG_PROC_FS |
2303f994 | 1272 | this_cpu_add(*net->core.sock_inuse, 1); |
f6f7d8cf | 1273 | #endif |
2303f994 PK |
1274 | err = tcp_set_ulp(sf->sk, "mptcp"); |
1275 | release_sock(sf->sk); | |
1276 | ||
b8ad540d WY |
1277 | if (err) { |
1278 | sock_release(sf); | |
2303f994 | 1279 | return err; |
b8ad540d | 1280 | } |
2303f994 | 1281 | |
7d14b0d2 PA |
1282 | /* the newly created socket really belongs to the owning MPTCP master |
1283 | * socket, even if for additional subflows the allocation is performed | |
1284 | * by a kernel workqueue. Adjust inode references, so that the | |
1285 | * procfs/diag interaces really show this one belonging to the correct | |
1286 | * user. | |
1287 | */ | |
1288 | SOCK_INODE(sf)->i_ino = SOCK_INODE(sk->sk_socket)->i_ino; | |
1289 | SOCK_INODE(sf)->i_uid = SOCK_INODE(sk->sk_socket)->i_uid; | |
1290 | SOCK_INODE(sf)->i_gid = SOCK_INODE(sk->sk_socket)->i_gid; | |
1291 | ||
2303f994 PK |
1292 | subflow = mptcp_subflow_ctx(sf->sk); |
1293 | pr_debug("subflow=%p", subflow); | |
1294 | ||
1295 | *new_sock = sf; | |
79c0949e | 1296 | sock_hold(sk); |
2303f994 PK |
1297 | subflow->conn = sk; |
1298 | ||
1299 | return 0; | |
1300 | } | |
1301 | ||
1302 | static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, | |
1303 | gfp_t priority) | |
1304 | { | |
1305 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1306 | struct mptcp_subflow_context *ctx; | |
1307 | ||
1308 | ctx = kzalloc(sizeof(*ctx), priority); | |
1309 | if (!ctx) | |
1310 | return NULL; | |
1311 | ||
1312 | rcu_assign_pointer(icsk->icsk_ulp_data, ctx); | |
cec37a6e | 1313 | INIT_LIST_HEAD(&ctx->node); |
2303f994 PK |
1314 | |
1315 | pr_debug("subflow=%p", ctx); | |
1316 | ||
1317 | ctx->tcp_sock = sk; | |
1318 | ||
1319 | return ctx; | |
1320 | } | |
1321 | ||
648ef4b8 MM |
1322 | static void __subflow_state_change(struct sock *sk) |
1323 | { | |
1324 | struct socket_wq *wq; | |
1325 | ||
1326 | rcu_read_lock(); | |
1327 | wq = rcu_dereference(sk->sk_wq); | |
1328 | if (skwq_has_sleeper(wq)) | |
1329 | wake_up_interruptible_all(&wq->wait); | |
1330 | rcu_read_unlock(); | |
1331 | } | |
1332 | ||
1333 | static bool subflow_is_done(const struct sock *sk) | |
1334 | { | |
1335 | return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE; | |
1336 | } | |
1337 | ||
1338 | static void subflow_state_change(struct sock *sk) | |
1339 | { | |
1340 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
dc093db5 | 1341 | struct sock *parent = subflow->conn; |
648ef4b8 MM |
1342 | |
1343 | __subflow_state_change(sk); | |
1344 | ||
8fd73804 DC |
1345 | if (subflow_simultaneous_connect(sk)) { |
1346 | mptcp_do_fallback(sk); | |
a6b118fe | 1347 | mptcp_rcv_space_init(mptcp_sk(parent), sk); |
8fd73804 DC |
1348 | pr_fallback(mptcp_sk(parent)); |
1349 | subflow->conn_finished = 1; | |
1350 | if (inet_sk_state_load(parent) == TCP_SYN_SENT) { | |
1351 | inet_sk_state_store(parent, TCP_ESTABLISHED); | |
1352 | parent->sk_state_change(parent); | |
1353 | } | |
1354 | } | |
1355 | ||
648ef4b8 MM |
1356 | /* as recvmsg() does not acquire the subflow socket for ssk selection |
1357 | * a fin packet carrying a DSS can be unnoticed if we don't trigger | |
1358 | * the data available machinery here. | |
1359 | */ | |
e1ff9e82 | 1360 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 1361 | mptcp_data_ready(parent, sk); |
648ef4b8 | 1362 | |
067a0b3d | 1363 | if (__mptcp_check_fallback(mptcp_sk(parent)) && |
648ef4b8 MM |
1364 | !subflow->rx_eof && subflow_is_done(sk)) { |
1365 | subflow->rx_eof = 1; | |
59832e24 | 1366 | mptcp_subflow_eof(parent); |
648ef4b8 MM |
1367 | } |
1368 | } | |
1369 | ||
2303f994 PK |
1370 | static int subflow_ulp_init(struct sock *sk) |
1371 | { | |
cec37a6e | 1372 | struct inet_connection_sock *icsk = inet_csk(sk); |
2303f994 PK |
1373 | struct mptcp_subflow_context *ctx; |
1374 | struct tcp_sock *tp = tcp_sk(sk); | |
1375 | int err = 0; | |
1376 | ||
1377 | /* disallow attaching ULP to a socket unless it has been | |
1378 | * created with sock_create_kern() | |
1379 | */ | |
1380 | if (!sk->sk_kern_sock) { | |
1381 | err = -EOPNOTSUPP; | |
1382 | goto out; | |
1383 | } | |
1384 | ||
1385 | ctx = subflow_create_ctx(sk, GFP_KERNEL); | |
1386 | if (!ctx) { | |
1387 | err = -ENOMEM; | |
1388 | goto out; | |
1389 | } | |
1390 | ||
1391 | pr_debug("subflow=%p, family=%d", ctx, sk->sk_family); | |
1392 | ||
1393 | tp->is_mptcp = 1; | |
cec37a6e PK |
1394 | ctx->icsk_af_ops = icsk->icsk_af_ops; |
1395 | icsk->icsk_af_ops = subflow_default_af_ops(sk); | |
648ef4b8 MM |
1396 | ctx->tcp_data_ready = sk->sk_data_ready; |
1397 | ctx->tcp_state_change = sk->sk_state_change; | |
1398 | ctx->tcp_write_space = sk->sk_write_space; | |
a5b31c47 | 1399 | ctx->tcp_error_report = sk->sk_error_report; |
648ef4b8 MM |
1400 | sk->sk_data_ready = subflow_data_ready; |
1401 | sk->sk_write_space = subflow_write_space; | |
1402 | sk->sk_state_change = subflow_state_change; | |
a5b31c47 | 1403 | sk->sk_error_report = subflow_error_report; |
2303f994 PK |
1404 | out: |
1405 | return err; | |
1406 | } | |
1407 | ||
e16163b6 | 1408 | static void subflow_ulp_release(struct sock *ssk) |
2303f994 | 1409 | { |
e16163b6 PA |
1410 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); |
1411 | bool release = true; | |
1412 | struct sock *sk; | |
2303f994 PK |
1413 | |
1414 | if (!ctx) | |
1415 | return; | |
1416 | ||
e16163b6 PA |
1417 | sk = ctx->conn; |
1418 | if (sk) { | |
1419 | /* if the msk has been orphaned, keep the ctx | |
0597d0f8 PA |
1420 | * alive, will be freed by __mptcp_close_ssk(), |
1421 | * when the subflow is still unaccepted | |
e16163b6 | 1422 | */ |
0597d0f8 | 1423 | release = ctx->disposable || list_empty(&ctx->node); |
e16163b6 PA |
1424 | sock_put(sk); |
1425 | } | |
79c0949e | 1426 | |
e16163b6 PA |
1427 | if (release) |
1428 | kfree_rcu(ctx, rcu); | |
2303f994 PK |
1429 | } |
1430 | ||
cec37a6e PK |
1431 | static void subflow_ulp_clone(const struct request_sock *req, |
1432 | struct sock *newsk, | |
1433 | const gfp_t priority) | |
1434 | { | |
1435 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
1436 | struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk); | |
1437 | struct mptcp_subflow_context *new_ctx; | |
1438 | ||
f296234c PK |
1439 | if (!tcp_rsk(req)->is_mptcp || |
1440 | (!subflow_req->mp_capable && !subflow_req->mp_join)) { | |
648ef4b8 | 1441 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1442 | return; |
1443 | } | |
1444 | ||
1445 | new_ctx = subflow_create_ctx(newsk, priority); | |
edc7e489 | 1446 | if (!new_ctx) { |
648ef4b8 | 1447 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1448 | return; |
1449 | } | |
1450 | ||
1451 | new_ctx->conn_finished = 1; | |
1452 | new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; | |
648ef4b8 MM |
1453 | new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; |
1454 | new_ctx->tcp_state_change = old_ctx->tcp_state_change; | |
1455 | new_ctx->tcp_write_space = old_ctx->tcp_write_space; | |
a5b31c47 | 1456 | new_ctx->tcp_error_report = old_ctx->tcp_error_report; |
58b09919 PA |
1457 | new_ctx->rel_write_seq = 1; |
1458 | new_ctx->tcp_sock = newsk; | |
1459 | ||
f296234c PK |
1460 | if (subflow_req->mp_capable) { |
1461 | /* see comments in subflow_syn_recv_sock(), MPTCP connection | |
1462 | * is fully established only after we receive the remote key | |
1463 | */ | |
1464 | new_ctx->mp_capable = 1; | |
f296234c PK |
1465 | new_ctx->local_key = subflow_req->local_key; |
1466 | new_ctx->token = subflow_req->token; | |
1467 | new_ctx->ssn_offset = subflow_req->ssn_offset; | |
1468 | new_ctx->idsn = subflow_req->idsn; | |
1469 | } else if (subflow_req->mp_join) { | |
ec3edaa7 | 1470 | new_ctx->ssn_offset = subflow_req->ssn_offset; |
f296234c PK |
1471 | new_ctx->mp_join = 1; |
1472 | new_ctx->fully_established = 1; | |
1473 | new_ctx->backup = subflow_req->backup; | |
1474 | new_ctx->local_id = subflow_req->local_id; | |
2ff0e566 | 1475 | new_ctx->remote_id = subflow_req->remote_id; |
f296234c PK |
1476 | new_ctx->token = subflow_req->token; |
1477 | new_ctx->thmac = subflow_req->thmac; | |
1478 | } | |
cec37a6e PK |
1479 | } |
1480 | ||
2303f994 PK |
1481 | static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { |
1482 | .name = "mptcp", | |
1483 | .owner = THIS_MODULE, | |
1484 | .init = subflow_ulp_init, | |
1485 | .release = subflow_ulp_release, | |
cec37a6e | 1486 | .clone = subflow_ulp_clone, |
2303f994 PK |
1487 | }; |
1488 | ||
cec37a6e PK |
1489 | static int subflow_ops_init(struct request_sock_ops *subflow_ops) |
1490 | { | |
1491 | subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock); | |
1492 | subflow_ops->slab_name = "request_sock_subflow"; | |
1493 | ||
1494 | subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name, | |
1495 | subflow_ops->obj_size, 0, | |
1496 | SLAB_ACCOUNT | | |
1497 | SLAB_TYPESAFE_BY_RCU, | |
1498 | NULL); | |
1499 | if (!subflow_ops->slab) | |
1500 | return -ENOMEM; | |
1501 | ||
79c0949e PK |
1502 | subflow_ops->destructor = subflow_req_destructor; |
1503 | ||
cec37a6e PK |
1504 | return 0; |
1505 | } | |
1506 | ||
d39dceca | 1507 | void __init mptcp_subflow_init(void) |
2303f994 | 1508 | { |
08b8d080 FW |
1509 | mptcp_subflow_request_sock_ops = tcp_request_sock_ops; |
1510 | if (subflow_ops_init(&mptcp_subflow_request_sock_ops) != 0) | |
cec37a6e PK |
1511 | panic("MPTCP: failed to init subflow request sock ops\n"); |
1512 | ||
1513 | subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops; | |
7ea851d1 | 1514 | subflow_request_sock_ipv4_ops.route_req = subflow_v4_route_req; |
cec37a6e PK |
1515 | |
1516 | subflow_specific = ipv4_specific; | |
1517 | subflow_specific.conn_request = subflow_v4_conn_request; | |
1518 | subflow_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1519 | subflow_specific.sk_rx_dst_set = subflow_finish_connect; | |
1520 | ||
1521 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1522 | subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; | |
7ea851d1 | 1523 | subflow_request_sock_ipv6_ops.route_req = subflow_v6_route_req; |
cec37a6e PK |
1524 | |
1525 | subflow_v6_specific = ipv6_specific; | |
1526 | subflow_v6_specific.conn_request = subflow_v6_conn_request; | |
1527 | subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1528 | subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect; | |
1529 | ||
1530 | subflow_v6m_specific = subflow_v6_specific; | |
1531 | subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit; | |
1532 | subflow_v6m_specific.send_check = ipv4_specific.send_check; | |
1533 | subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; | |
1534 | subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; | |
1535 | subflow_v6m_specific.net_frag_header_len = 0; | |
1536 | #endif | |
1537 | ||
5147dfb5 DC |
1538 | mptcp_diag_subflow_init(&subflow_ulp_ops); |
1539 | ||
2303f994 PK |
1540 | if (tcp_register_ulp(&subflow_ulp_ops) != 0) |
1541 | panic("MPTCP: failed to register subflows to ULP\n"); | |
1542 | } |