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> | |
b19bc294 | 21 | #include <net/transp_v6.h> |
cec37a6e | 22 | #endif |
2303f994 | 23 | #include <net/mptcp.h> |
4596a2c1 | 24 | #include <uapi/linux/mptcp.h> |
2303f994 | 25 | #include "protocol.h" |
fc518953 FW |
26 | #include "mib.h" |
27 | ||
0918e34b GT |
28 | #include <trace/events/mptcp.h> |
29 | ||
b19bc294 PA |
30 | static void mptcp_subflow_ops_undo_override(struct sock *ssk); |
31 | ||
fc518953 FW |
32 | static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, |
33 | enum linux_mptcp_mib_field field) | |
34 | { | |
35 | MPTCP_INC_STATS(sock_net(req_to_sk(req)), field); | |
36 | } | |
2303f994 | 37 | |
79c0949e PK |
38 | static void subflow_req_destructor(struct request_sock *req) |
39 | { | |
40 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
41 | ||
42 | pr_debug("subflow_req=%p", subflow_req); | |
43 | ||
8fd4de12 PA |
44 | if (subflow_req->msk) |
45 | sock_put((struct sock *)subflow_req->msk); | |
46 | ||
2c5ebd00 | 47 | mptcp_token_destroy_request(req); |
79c0949e PK |
48 | tcp_request_sock_ops.destructor(req); |
49 | } | |
50 | ||
f296234c PK |
51 | static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2, |
52 | void *hmac) | |
53 | { | |
54 | u8 msg[8]; | |
55 | ||
56 | put_unaligned_be32(nonce1, &msg[0]); | |
57 | put_unaligned_be32(nonce2, &msg[4]); | |
58 | ||
59 | mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac); | |
60 | } | |
61 | ||
4cf8b7e4 PA |
62 | static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk) |
63 | { | |
64 | return mptcp_is_fully_established((void *)msk) && | |
65 | READ_ONCE(msk->pm.accept_subflow); | |
66 | } | |
67 | ||
f296234c | 68 | /* validate received token and create truncated hmac and nonce for SYN-ACK */ |
ec20e143 GT |
69 | static void subflow_req_create_thmac(struct mptcp_subflow_request_sock *subflow_req) |
70 | { | |
71 | struct mptcp_sock *msk = subflow_req->msk; | |
72 | u8 hmac[SHA256_DIGEST_SIZE]; | |
73 | ||
74 | get_random_bytes(&subflow_req->local_nonce, sizeof(u32)); | |
75 | ||
76 | subflow_generate_hmac(msk->local_key, msk->remote_key, | |
77 | subflow_req->local_nonce, | |
78 | subflow_req->remote_nonce, hmac); | |
79 | ||
80 | subflow_req->thmac = get_unaligned_be64(hmac); | |
81 | } | |
82 | ||
b5e2e42f | 83 | static struct mptcp_sock *subflow_token_join_request(struct request_sock *req) |
f296234c PK |
84 | { |
85 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
f296234c PK |
86 | struct mptcp_sock *msk; |
87 | int local_id; | |
88 | ||
89 | msk = mptcp_token_get_sock(subflow_req->token); | |
90 | if (!msk) { | |
fc518953 | 91 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINNOTOKEN); |
8fd4de12 | 92 | return NULL; |
f296234c PK |
93 | } |
94 | ||
95 | local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); | |
96 | if (local_id < 0) { | |
97 | sock_put((struct sock *)msk); | |
8fd4de12 | 98 | return NULL; |
f296234c PK |
99 | } |
100 | subflow_req->local_id = local_id; | |
101 | ||
8fd4de12 | 102 | return msk; |
f296234c PK |
103 | } |
104 | ||
d8b59efa | 105 | static void subflow_init_req(struct request_sock *req, const struct sock *sk_listener) |
cec37a6e | 106 | { |
cec37a6e | 107 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); |
cec37a6e PK |
108 | |
109 | subflow_req->mp_capable = 0; | |
f296234c | 110 | subflow_req->mp_join = 0; |
06fe1719 | 111 | subflow_req->csum_reqd = mptcp_is_checksum_enabled(sock_net(sk_listener)); |
bab6b88e | 112 | subflow_req->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk_listener)); |
8fd4de12 | 113 | subflow_req->msk = NULL; |
2c5ebd00 | 114 | mptcp_token_init_request(req); |
78d8b7bc FW |
115 | } |
116 | ||
5bc56388 GT |
117 | static bool subflow_use_different_sport(struct mptcp_sock *msk, const struct sock *sk) |
118 | { | |
119 | return inet_sk(sk)->inet_sport != inet_sk((struct sock *)msk)->inet_sport; | |
120 | } | |
121 | ||
dc87efdb FW |
122 | static void subflow_add_reset_reason(struct sk_buff *skb, u8 reason) |
123 | { | |
124 | struct mptcp_ext *mpext = skb_ext_add(skb, SKB_EXT_MPTCP); | |
125 | ||
126 | if (mpext) { | |
127 | memset(mpext, 0, sizeof(*mpext)); | |
128 | mpext->reset_reason = reason; | |
129 | } | |
130 | } | |
131 | ||
3ecfbe3e FW |
132 | /* Init mptcp request socket. |
133 | * | |
134 | * Returns an error code if a JOIN has failed and a TCP reset | |
135 | * should be sent. | |
136 | */ | |
d8b59efa PA |
137 | static int subflow_check_req(struct request_sock *req, |
138 | const struct sock *sk_listener, | |
139 | struct sk_buff *skb) | |
78d8b7bc FW |
140 | { |
141 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
142 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
143 | struct mptcp_options_received mp_opt; | |
78d8b7bc FW |
144 | |
145 | pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); | |
146 | ||
d8b59efa PA |
147 | #ifdef CONFIG_TCP_MD5SIG |
148 | /* no MPTCP if MD5SIG is enabled on this socket or we may run out of | |
149 | * TCP option space. | |
150 | */ | |
151 | if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) | |
152 | return -EINVAL; | |
153 | #endif | |
78d8b7bc | 154 | |
c863225b | 155 | mptcp_get_options(sk_listener, skb, &mp_opt); |
78d8b7bc | 156 | |
cfde141e | 157 | if (mp_opt.mp_capable) { |
fc518953 FW |
158 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); |
159 | ||
cfde141e | 160 | if (mp_opt.mp_join) |
3ecfbe3e | 161 | return 0; |
cfde141e | 162 | } else if (mp_opt.mp_join) { |
fc518953 FW |
163 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); |
164 | } | |
f296234c | 165 | |
cfde141e | 166 | if (mp_opt.mp_capable && listener->request_mptcp) { |
c68a0cd1 | 167 | int err, retries = MPTCP_TOKEN_MAX_RETRIES; |
535fb815 | 168 | |
c83a47e5 | 169 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
535fb815 FW |
170 | again: |
171 | do { | |
172 | get_random_bytes(&subflow_req->local_key, sizeof(subflow_req->local_key)); | |
173 | } while (subflow_req->local_key == 0); | |
79c0949e | 174 | |
c83a47e5 FW |
175 | if (unlikely(req->syncookie)) { |
176 | mptcp_crypto_key_sha(subflow_req->local_key, | |
177 | &subflow_req->token, | |
178 | &subflow_req->idsn); | |
179 | if (mptcp_token_exists(subflow_req->token)) { | |
180 | if (retries-- > 0) | |
181 | goto again; | |
a16195e3 | 182 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT); |
c83a47e5 FW |
183 | } else { |
184 | subflow_req->mp_capable = 1; | |
185 | } | |
3ecfbe3e | 186 | return 0; |
c83a47e5 FW |
187 | } |
188 | ||
79c0949e PK |
189 | err = mptcp_token_new_request(req); |
190 | if (err == 0) | |
191 | subflow_req->mp_capable = 1; | |
535fb815 FW |
192 | else if (retries-- > 0) |
193 | goto again; | |
a16195e3 PA |
194 | else |
195 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT); | |
79c0949e | 196 | |
cfde141e | 197 | } else if (mp_opt.mp_join && listener->request_mptcp) { |
ec3edaa7 | 198 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
f296234c | 199 | subflow_req->mp_join = 1; |
cfde141e PA |
200 | subflow_req->backup = mp_opt.backup; |
201 | subflow_req->remote_id = mp_opt.join_id; | |
202 | subflow_req->token = mp_opt.token; | |
203 | subflow_req->remote_nonce = mp_opt.nonce; | |
b5e2e42f | 204 | subflow_req->msk = subflow_token_join_request(req); |
9466a1cc | 205 | |
3ecfbe3e | 206 | /* Can't fall back to TCP in this case. */ |
dc87efdb FW |
207 | if (!subflow_req->msk) { |
208 | subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); | |
3ecfbe3e | 209 | return -EPERM; |
dc87efdb | 210 | } |
3ecfbe3e | 211 | |
5bc56388 GT |
212 | if (subflow_use_different_sport(subflow_req->msk, sk_listener)) { |
213 | pr_debug("syn inet_sport=%d %d", | |
214 | ntohs(inet_sk(sk_listener)->inet_sport), | |
215 | ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport)); | |
216 | if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) { | |
2fbdd9ea | 217 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTSYNRX); |
5bc56388 GT |
218 | return -EPERM; |
219 | } | |
2fbdd9ea | 220 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINPORTSYNRX); |
5bc56388 GT |
221 | } |
222 | ||
ec20e143 GT |
223 | subflow_req_create_thmac(subflow_req); |
224 | ||
3ecfbe3e | 225 | if (unlikely(req->syncookie)) { |
9466a1cc FW |
226 | if (mptcp_can_accept_new_subflow(subflow_req->msk)) |
227 | subflow_init_req_cookie_join_save(subflow_req, skb); | |
228 | } | |
229 | ||
8fd4de12 PA |
230 | pr_debug("token=%u, remote_nonce=%u msk=%p", subflow_req->token, |
231 | subflow_req->remote_nonce, subflow_req->msk); | |
cec37a6e | 232 | } |
3ecfbe3e FW |
233 | |
234 | return 0; | |
cec37a6e PK |
235 | } |
236 | ||
c83a47e5 FW |
237 | int mptcp_subflow_init_cookie_req(struct request_sock *req, |
238 | const struct sock *sk_listener, | |
239 | struct sk_buff *skb) | |
240 | { | |
241 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
242 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
243 | struct mptcp_options_received mp_opt; | |
244 | int err; | |
245 | ||
d8b59efa | 246 | subflow_init_req(req, sk_listener); |
c863225b | 247 | mptcp_get_options(sk_listener, skb, &mp_opt); |
c83a47e5 FW |
248 | |
249 | if (mp_opt.mp_capable && mp_opt.mp_join) | |
250 | return -EINVAL; | |
251 | ||
252 | if (mp_opt.mp_capable && listener->request_mptcp) { | |
253 | if (mp_opt.sndr_key == 0) | |
254 | return -EINVAL; | |
255 | ||
256 | subflow_req->local_key = mp_opt.rcvr_key; | |
257 | err = mptcp_token_new_request(req); | |
258 | if (err) | |
259 | return err; | |
260 | ||
261 | subflow_req->mp_capable = 1; | |
262 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
9466a1cc FW |
263 | } else if (mp_opt.mp_join && listener->request_mptcp) { |
264 | if (!mptcp_token_join_cookie_init_state(subflow_req, skb)) | |
265 | return -EINVAL; | |
266 | ||
267 | if (mptcp_can_accept_new_subflow(subflow_req->msk)) | |
268 | subflow_req->mp_join = 1; | |
269 | ||
270 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
c83a47e5 FW |
271 | } |
272 | ||
273 | return 0; | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); | |
276 | ||
7ea851d1 FW |
277 | static struct dst_entry *subflow_v4_route_req(const struct sock *sk, |
278 | struct sk_buff *skb, | |
279 | struct flowi *fl, | |
280 | struct request_sock *req) | |
cec37a6e | 281 | { |
7ea851d1 | 282 | struct dst_entry *dst; |
3ecfbe3e | 283 | int err; |
7ea851d1 | 284 | |
cec37a6e | 285 | tcp_rsk(req)->is_mptcp = 1; |
d8b59efa | 286 | subflow_init_req(req, sk); |
cec37a6e | 287 | |
7ea851d1 FW |
288 | dst = tcp_request_sock_ipv4_ops.route_req(sk, skb, fl, req); |
289 | if (!dst) | |
290 | return NULL; | |
cec37a6e | 291 | |
d8b59efa | 292 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
293 | if (err == 0) |
294 | return dst; | |
cec37a6e | 295 | |
3ecfbe3e FW |
296 | dst_release(dst); |
297 | if (!req->syncookie) | |
298 | tcp_request_sock_ops.send_reset(sk, skb); | |
299 | return NULL; | |
cec37a6e PK |
300 | } |
301 | ||
302 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
7ea851d1 FW |
303 | static struct dst_entry *subflow_v6_route_req(const struct sock *sk, |
304 | struct sk_buff *skb, | |
305 | struct flowi *fl, | |
306 | struct request_sock *req) | |
cec37a6e | 307 | { |
7ea851d1 | 308 | struct dst_entry *dst; |
3ecfbe3e | 309 | int err; |
7ea851d1 | 310 | |
cec37a6e | 311 | tcp_rsk(req)->is_mptcp = 1; |
d8b59efa | 312 | subflow_init_req(req, sk); |
cec37a6e | 313 | |
7ea851d1 FW |
314 | dst = tcp_request_sock_ipv6_ops.route_req(sk, skb, fl, req); |
315 | if (!dst) | |
316 | return NULL; | |
cec37a6e | 317 | |
d8b59efa | 318 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
319 | if (err == 0) |
320 | return dst; | |
321 | ||
322 | dst_release(dst); | |
323 | if (!req->syncookie) | |
324 | tcp6_request_sock_ops.send_reset(sk, skb); | |
325 | return NULL; | |
cec37a6e PK |
326 | } |
327 | #endif | |
328 | ||
ec3edaa7 PK |
329 | /* validate received truncated hmac and create hmac for third ACK */ |
330 | static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) | |
331 | { | |
bd697222 | 332 | u8 hmac[SHA256_DIGEST_SIZE]; |
ec3edaa7 PK |
333 | u64 thmac; |
334 | ||
335 | subflow_generate_hmac(subflow->remote_key, subflow->local_key, | |
336 | subflow->remote_nonce, subflow->local_nonce, | |
337 | hmac); | |
338 | ||
339 | thmac = get_unaligned_be64(hmac); | |
340 | pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", | |
341 | subflow, subflow->token, | |
342 | (unsigned long long)thmac, | |
343 | (unsigned long long)subflow->thmac); | |
344 | ||
345 | return thmac == subflow->thmac; | |
346 | } | |
347 | ||
d5824847 PA |
348 | void mptcp_subflow_reset(struct sock *ssk) |
349 | { | |
0e4f35d7 PA |
350 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); |
351 | struct sock *sk = subflow->conn; | |
352 | ||
ab82e996 FW |
353 | /* must hold: tcp_done() could drop last reference on parent */ |
354 | sock_hold(sk); | |
355 | ||
d5824847 PA |
356 | tcp_set_state(ssk, TCP_CLOSE); |
357 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
358 | tcp_done(ssk); | |
0e4f35d7 PA |
359 | if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && |
360 | schedule_work(&mptcp_sk(sk)->work)) | |
ab82e996 FW |
361 | return; /* worker will put sk for us */ |
362 | ||
363 | sock_put(sk); | |
d5824847 PA |
364 | } |
365 | ||
5bc56388 GT |
366 | static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct sock *sk) |
367 | { | |
368 | return inet_sk(sk)->inet_dport != inet_sk((struct sock *)msk)->inet_dport; | |
369 | } | |
370 | ||
490274b4 PA |
371 | void __mptcp_set_connected(struct sock *sk) |
372 | { | |
373 | if (sk->sk_state == TCP_SYN_SENT) { | |
374 | inet_sk_state_store(sk, TCP_ESTABLISHED); | |
375 | sk->sk_state_change(sk); | |
376 | } | |
377 | } | |
378 | ||
379 | static void mptcp_set_connected(struct sock *sk) | |
380 | { | |
381 | mptcp_data_lock(sk); | |
382 | if (!sock_owned_by_user(sk)) | |
383 | __mptcp_set_connected(sk); | |
384 | else | |
385 | set_bit(MPTCP_CONNECTED, &mptcp_sk(sk)->flags); | |
386 | mptcp_data_unlock(sk); | |
387 | } | |
388 | ||
cec37a6e PK |
389 | static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) |
390 | { | |
391 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cfde141e | 392 | struct mptcp_options_received mp_opt; |
c3c123d1 | 393 | struct sock *parent = subflow->conn; |
cec37a6e PK |
394 | |
395 | subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); | |
396 | ||
c3c123d1 | 397 | |
263e1201 PA |
398 | /* be sure no special action on any packet other than syn-ack */ |
399 | if (subflow->conn_finished) | |
400 | return; | |
401 | ||
5cf92bba | 402 | mptcp_propagate_sndbuf(parent, sk); |
b0977bb2 | 403 | subflow->rel_write_seq = 1; |
263e1201 | 404 | subflow->conn_finished = 1; |
e1ff9e82 DC |
405 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; |
406 | pr_debug("subflow=%p synack seq=%x", subflow, subflow->ssn_offset); | |
263e1201 | 407 | |
c863225b | 408 | mptcp_get_options(sk, skb, &mp_opt); |
fa25e815 PA |
409 | if (subflow->request_mptcp) { |
410 | if (!mp_opt.mp_capable) { | |
411 | MPTCP_INC_STATS(sock_net(sk), | |
412 | MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); | |
413 | mptcp_do_fallback(sk); | |
414 | pr_fallback(mptcp_sk(subflow->conn)); | |
415 | goto fallback; | |
416 | } | |
417 | ||
06251181 GT |
418 | if (mp_opt.csum_reqd) |
419 | WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true); | |
df377be3 GT |
420 | if (mp_opt.deny_join_id0) |
421 | WRITE_ONCE(mptcp_sk(parent)->pm.remote_deny_join_id0, true); | |
263e1201 PA |
422 | subflow->mp_capable = 1; |
423 | subflow->can_ack = 1; | |
cfde141e | 424 | subflow->remote_key = mp_opt.sndr_key; |
263e1201 PA |
425 | pr_debug("subflow=%p, remote_key=%llu", subflow, |
426 | subflow->remote_key); | |
5695eb88 | 427 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEACK); |
fa25e815 | 428 | mptcp_finish_connect(sk); |
490274b4 | 429 | mptcp_set_connected(parent); |
fa25e815 PA |
430 | } else if (subflow->request_join) { |
431 | u8 hmac[SHA256_DIGEST_SIZE]; | |
432 | ||
dc87efdb FW |
433 | if (!mp_opt.mp_join) { |
434 | subflow->reset_reason = MPTCP_RST_EMPTCP; | |
fa25e815 | 435 | goto do_reset; |
dc87efdb | 436 | } |
fa25e815 | 437 | |
cfde141e PA |
438 | subflow->thmac = mp_opt.thmac; |
439 | subflow->remote_nonce = mp_opt.nonce; | |
263e1201 PA |
440 | pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, |
441 | subflow->thmac, subflow->remote_nonce); | |
263e1201 | 442 | |
ec3edaa7 | 443 | if (!subflow_thmac_valid(subflow)) { |
fc518953 | 444 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC); |
dc87efdb | 445 | subflow->reset_reason = MPTCP_RST_EMPTCP; |
ec3edaa7 PK |
446 | goto do_reset; |
447 | } | |
448 | ||
0a4d8e96 JW |
449 | if (!mptcp_finish_join(sk)) |
450 | goto do_reset; | |
451 | ||
ec3edaa7 PK |
452 | subflow_generate_hmac(subflow->local_key, subflow->remote_key, |
453 | subflow->local_nonce, | |
454 | subflow->remote_nonce, | |
bd697222 | 455 | hmac); |
bd697222 | 456 | memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN); |
ec3edaa7 | 457 | |
fa25e815 | 458 | subflow->mp_join = 1; |
fc518953 | 459 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); |
5bc56388 GT |
460 | |
461 | if (subflow_use_different_dport(mptcp_sk(parent), sk)) { | |
462 | pr_debug("synack inet_dport=%d %d", | |
463 | ntohs(inet_sk(sk)->inet_dport), | |
464 | ntohs(inet_sk(parent)->inet_dport)); | |
2fbdd9ea | 465 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINPORTSYNACKRX); |
5bc56388 | 466 | } |
fa25e815 PA |
467 | } else if (mptcp_check_fallback(sk)) { |
468 | fallback: | |
469 | mptcp_rcv_space_init(mptcp_sk(parent), sk); | |
490274b4 | 470 | mptcp_set_connected(parent); |
cec37a6e | 471 | } |
fa25e815 PA |
472 | return; |
473 | ||
474 | do_reset: | |
dc87efdb | 475 | subflow->reset_transient = 0; |
d5824847 | 476 | mptcp_subflow_reset(sk); |
cec37a6e PK |
477 | } |
478 | ||
08b8d080 FW |
479 | struct request_sock_ops mptcp_subflow_request_sock_ops; |
480 | EXPORT_SYMBOL_GPL(mptcp_subflow_request_sock_ops); | |
cec37a6e PK |
481 | static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops; |
482 | ||
483 | static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
484 | { | |
485 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
486 | ||
487 | pr_debug("subflow=%p", subflow); | |
488 | ||
489 | /* Never answer to SYNs sent to broadcast or multicast */ | |
490 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
491 | goto drop; | |
492 | ||
08b8d080 | 493 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
494 | &subflow_request_sock_ipv4_ops, |
495 | sk, skb); | |
496 | drop: | |
497 | tcp_listendrop(sk); | |
498 | return 0; | |
499 | } | |
500 | ||
501 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
502 | static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; | |
503 | static struct inet_connection_sock_af_ops subflow_v6_specific; | |
504 | static struct inet_connection_sock_af_ops subflow_v6m_specific; | |
b19bc294 | 505 | static struct proto tcpv6_prot_override; |
cec37a6e PK |
506 | |
507 | static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) | |
508 | { | |
509 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
510 | ||
511 | pr_debug("subflow=%p", subflow); | |
512 | ||
513 | if (skb->protocol == htons(ETH_P_IP)) | |
514 | return subflow_v4_conn_request(sk, skb); | |
515 | ||
516 | if (!ipv6_unicast_destination(skb)) | |
517 | goto drop; | |
518 | ||
dcc32f4f JK |
519 | if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { |
520 | __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); | |
521 | return 0; | |
522 | } | |
523 | ||
08b8d080 | 524 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
525 | &subflow_request_sock_ipv6_ops, sk, skb); |
526 | ||
527 | drop: | |
528 | tcp_listendrop(sk); | |
529 | return 0; /* don't send reset */ | |
530 | } | |
531 | #endif | |
532 | ||
f296234c PK |
533 | /* validate hmac received in third ACK */ |
534 | static bool subflow_hmac_valid(const struct request_sock *req, | |
cfde141e | 535 | const struct mptcp_options_received *mp_opt) |
f296234c PK |
536 | { |
537 | const struct mptcp_subflow_request_sock *subflow_req; | |
bd697222 | 538 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c | 539 | struct mptcp_sock *msk; |
f296234c PK |
540 | |
541 | subflow_req = mptcp_subflow_rsk(req); | |
8fd4de12 | 542 | msk = subflow_req->msk; |
f296234c PK |
543 | if (!msk) |
544 | return false; | |
545 | ||
546 | subflow_generate_hmac(msk->remote_key, msk->local_key, | |
547 | subflow_req->remote_nonce, | |
548 | subflow_req->local_nonce, hmac); | |
549 | ||
8fd4de12 | 550 | return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN); |
f296234c PK |
551 | } |
552 | ||
df1036da FW |
553 | static void mptcp_sock_destruct(struct sock *sk) |
554 | { | |
555 | /* if new mptcp socket isn't accepted, it is free'd | |
556 | * from the tcp listener sockets request queue, linked | |
557 | * from req->sk. The tcp socket is released. | |
558 | * This calls the ULP release function which will | |
559 | * also remove the mptcp socket, via | |
560 | * sock_put(ctx->conn). | |
561 | * | |
7ee24926 PA |
562 | * Problem is that the mptcp socket will be in |
563 | * ESTABLISHED state and will not have the SOCK_DEAD flag. | |
df1036da FW |
564 | * Both result in warnings from inet_sock_destruct. |
565 | */ | |
578c18ef | 566 | if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { |
df1036da FW |
567 | sk->sk_state = TCP_CLOSE; |
568 | WARN_ON_ONCE(sk->sk_socket); | |
569 | sock_orphan(sk); | |
570 | } | |
571 | ||
5c8c1640 | 572 | mptcp_destroy_common(mptcp_sk(sk)); |
df1036da FW |
573 | inet_sock_destruct(sk); |
574 | } | |
575 | ||
9f5ca6a5 FW |
576 | static void mptcp_force_close(struct sock *sk) |
577 | { | |
490274b4 | 578 | /* the msk is not yet exposed to user-space */ |
9f5ca6a5 FW |
579 | inet_sk_state_store(sk, TCP_CLOSE); |
580 | sk_common_release(sk); | |
581 | } | |
582 | ||
4c8941de PA |
583 | static void subflow_ulp_fallback(struct sock *sk, |
584 | struct mptcp_subflow_context *old_ctx) | |
585 | { | |
586 | struct inet_connection_sock *icsk = inet_csk(sk); | |
587 | ||
588 | mptcp_subflow_tcp_fallback(sk, old_ctx); | |
589 | icsk->icsk_ulp_ops = NULL; | |
590 | rcu_assign_pointer(icsk->icsk_ulp_data, NULL); | |
591 | tcp_sk(sk)->is_mptcp = 0; | |
b19bc294 PA |
592 | |
593 | mptcp_subflow_ops_undo_override(sk); | |
4c8941de PA |
594 | } |
595 | ||
39884604 PA |
596 | static void subflow_drop_ctx(struct sock *ssk) |
597 | { | |
598 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); | |
599 | ||
600 | if (!ctx) | |
601 | return; | |
602 | ||
603 | subflow_ulp_fallback(ssk, ctx); | |
604 | if (ctx->conn) | |
605 | sock_put(ctx->conn); | |
606 | ||
607 | kfree_rcu(ctx, rcu); | |
608 | } | |
609 | ||
b93df08c PA |
610 | void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, |
611 | struct mptcp_options_received *mp_opt) | |
612 | { | |
613 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
614 | ||
615 | subflow->remote_key = mp_opt->sndr_key; | |
616 | subflow->fully_established = 1; | |
617 | subflow->can_ack = 1; | |
618 | WRITE_ONCE(msk->fully_established, true); | |
619 | } | |
620 | ||
cec37a6e PK |
621 | static struct sock *subflow_syn_recv_sock(const struct sock *sk, |
622 | struct sk_buff *skb, | |
623 | struct request_sock *req, | |
624 | struct dst_entry *dst, | |
625 | struct request_sock *req_unhash, | |
626 | bool *own_req) | |
627 | { | |
628 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk); | |
cc7972ea | 629 | struct mptcp_subflow_request_sock *subflow_req; |
cfde141e | 630 | struct mptcp_options_received mp_opt; |
9e365ff5 | 631 | bool fallback, fallback_is_fatal; |
58b09919 | 632 | struct sock *new_msk = NULL; |
cec37a6e PK |
633 | struct sock *child; |
634 | ||
635 | pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); | |
636 | ||
9e365ff5 PA |
637 | /* After child creation we must look for 'mp_capable' even when options |
638 | * are not parsed | |
cfde141e PA |
639 | */ |
640 | mp_opt.mp_capable = 0; | |
9e365ff5 PA |
641 | |
642 | /* hopefully temporary handling for MP_JOIN+syncookie */ | |
643 | subflow_req = mptcp_subflow_rsk(req); | |
b7514694 | 644 | fallback_is_fatal = tcp_rsk(req)->is_mptcp && subflow_req->mp_join; |
9e365ff5 PA |
645 | fallback = !tcp_rsk(req)->is_mptcp; |
646 | if (fallback) | |
ae2dd716 FW |
647 | goto create_child; |
648 | ||
d22f4988 | 649 | /* if the sk is MP_CAPABLE, we try to fetch the client key */ |
cc7972ea | 650 | if (subflow_req->mp_capable) { |
06f9a435 PA |
651 | /* we can receive and accept an in-window, out-of-order pkt, |
652 | * which may not carry the MP_CAPABLE opt even on mptcp enabled | |
653 | * paths: always try to extract the peer key, and fallback | |
654 | * for packets missing it. | |
655 | * Even OoO DSS packets coming legitly after dropped or | |
656 | * reordered MPC will cause fallback, but we don't have other | |
657 | * options. | |
658 | */ | |
c863225b | 659 | mptcp_get_options(sk, skb, &mp_opt); |
cfde141e | 660 | if (!mp_opt.mp_capable) { |
4c8941de | 661 | fallback = true; |
58b09919 | 662 | goto create_child; |
d22f4988 | 663 | } |
58b09919 | 664 | |
cfde141e | 665 | new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); |
58b09919 | 666 | if (!new_msk) |
4c8941de | 667 | fallback = true; |
f296234c | 668 | } else if (subflow_req->mp_join) { |
c863225b | 669 | mptcp_get_options(sk, skb, &mp_opt); |
d3ab7885 PA |
670 | if (!mp_opt.mp_join || !subflow_hmac_valid(req, &mp_opt) || |
671 | !mptcp_can_accept_new_subflow(subflow_req->msk)) { | |
fc518953 | 672 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); |
9e365ff5 | 673 | fallback = true; |
fc518953 | 674 | } |
cc7972ea | 675 | } |
cec37a6e | 676 | |
d22f4988 | 677 | create_child: |
cec37a6e PK |
678 | child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, |
679 | req_unhash, own_req); | |
680 | ||
681 | if (child && *own_req) { | |
79c0949e PK |
682 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); |
683 | ||
90bf4513 PA |
684 | tcp_rsk(req)->drop_req = false; |
685 | ||
4c8941de PA |
686 | /* we need to fallback on ctx allocation failure and on pre-reqs |
687 | * checking above. In the latter scenario we additionally need | |
688 | * to reset the context to non MPTCP status. | |
79c0949e | 689 | */ |
4c8941de | 690 | if (!ctx || fallback) { |
dc87efdb FW |
691 | if (fallback_is_fatal) { |
692 | subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); | |
729cd643 | 693 | goto dispose_child; |
dc87efdb | 694 | } |
4c8941de | 695 | |
39884604 | 696 | subflow_drop_ctx(child); |
58b09919 | 697 | goto out; |
f296234c | 698 | } |
79c0949e | 699 | |
df00b087 FW |
700 | /* ssk inherits options of listener sk */ |
701 | ctx->setsockopt_seq = listener->setsockopt_seq; | |
702 | ||
79c0949e | 703 | if (ctx->mp_capable) { |
b93df08c PA |
704 | /* this can't race with mptcp_close(), as the msk is |
705 | * not yet exposted to user-space | |
706 | */ | |
707 | inet_sk_state_store((void *)new_msk, TCP_ESTABLISHED); | |
708 | ||
5b950ff4 PA |
709 | /* record the newly created socket as the first msk |
710 | * subflow, but don't link it yet into conn_list | |
711 | */ | |
0397c6d8 PA |
712 | WRITE_ONCE(mptcp_sk(new_msk)->first, child); |
713 | ||
58b09919 PA |
714 | /* new mpc subflow takes ownership of the newly |
715 | * created mptcp socket | |
716 | */ | |
df1036da | 717 | new_msk->sk_destruct = mptcp_sock_destruct; |
df00b087 | 718 | mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq; |
6c714f1b | 719 | mptcp_pm_new_connection(mptcp_sk(new_msk), child, 1); |
2c5ebd00 | 720 | mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); |
58b09919 PA |
721 | ctx->conn = new_msk; |
722 | new_msk = NULL; | |
fca5c82c PA |
723 | |
724 | /* with OoO packets we can reach here without ingress | |
725 | * mpc option | |
726 | */ | |
b93df08c PA |
727 | if (mp_opt.mp_capable) |
728 | mptcp_subflow_fully_established(ctx, &mp_opt); | |
f296234c PK |
729 | } else if (ctx->mp_join) { |
730 | struct mptcp_sock *owner; | |
731 | ||
8fd4de12 | 732 | owner = subflow_req->msk; |
dc87efdb FW |
733 | if (!owner) { |
734 | subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT); | |
729cd643 | 735 | goto dispose_child; |
dc87efdb | 736 | } |
f296234c | 737 | |
8fd4de12 PA |
738 | /* move the msk reference ownership to the subflow */ |
739 | subflow_req->msk = NULL; | |
f296234c | 740 | ctx->conn = (struct sock *)owner; |
5bc56388 GT |
741 | |
742 | if (subflow_use_different_sport(owner, sk)) { | |
743 | pr_debug("ack inet_sport=%d %d", | |
744 | ntohs(inet_sk(sk)->inet_sport), | |
745 | ntohs(inet_sk((struct sock *)owner)->inet_sport)); | |
2fbdd9ea GT |
746 | if (!mptcp_pm_sport_in_anno_list(owner, sk)) { |
747 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTACKRX); | |
9238e900 | 748 | goto dispose_child; |
2fbdd9ea GT |
749 | } |
750 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINPORTACKRX); | |
5bc56388 | 751 | } |
9238e900 GT |
752 | |
753 | if (!mptcp_finish_join(child)) | |
754 | goto dispose_child; | |
755 | ||
756 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); | |
757 | tcp_rsk(req)->drop_req = true; | |
cec37a6e PK |
758 | } |
759 | } | |
760 | ||
58b09919 PA |
761 | out: |
762 | /* dispose of the left over mptcp master, if any */ | |
763 | if (unlikely(new_msk)) | |
9f5ca6a5 | 764 | mptcp_force_close(new_msk); |
4c8941de PA |
765 | |
766 | /* check for expected invariant - should never trigger, just help | |
767 | * catching eariler subtle bugs | |
768 | */ | |
ac2b47fb | 769 | WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp && |
4c8941de PA |
770 | (!mptcp_subflow_ctx(child) || |
771 | !mptcp_subflow_ctx(child)->conn)); | |
cec37a6e | 772 | return child; |
f296234c | 773 | |
729cd643 | 774 | dispose_child: |
39884604 | 775 | subflow_drop_ctx(child); |
729cd643 | 776 | tcp_rsk(req)->drop_req = true; |
729cd643 | 777 | inet_csk_prepare_for_destroy_sock(child); |
f296234c | 778 | tcp_done(child); |
97e61751 | 779 | req->rsk_ops->send_reset(sk, skb); |
729cd643 PA |
780 | |
781 | /* The last child reference will be released by the caller */ | |
782 | return child; | |
cec37a6e PK |
783 | } |
784 | ||
785 | static struct inet_connection_sock_af_ops subflow_specific; | |
b19bc294 | 786 | static struct proto tcp_prot_override; |
cec37a6e | 787 | |
648ef4b8 MM |
788 | enum mapping_status { |
789 | MAPPING_OK, | |
790 | MAPPING_INVALID, | |
791 | MAPPING_EMPTY, | |
e1ff9e82 DC |
792 | MAPPING_DATA_FIN, |
793 | MAPPING_DUMMY | |
648ef4b8 MM |
794 | }; |
795 | ||
61e71022 | 796 | static void dbg_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) |
648ef4b8 | 797 | { |
61e71022 PA |
798 | pr_debug("Bad mapping: ssn=%d map_seq=%d map_data_len=%d", |
799 | ssn, subflow->map_subflow_seq, subflow->map_data_len); | |
648ef4b8 MM |
800 | } |
801 | ||
802 | static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) | |
803 | { | |
804 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
805 | unsigned int skb_consumed; | |
806 | ||
807 | skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; | |
808 | if (WARN_ON_ONCE(skb_consumed >= skb->len)) | |
809 | return true; | |
810 | ||
811 | return skb->len - skb_consumed <= subflow->map_data_len - | |
812 | mptcp_subflow_get_map_offset(subflow); | |
813 | } | |
814 | ||
815 | static bool validate_mapping(struct sock *ssk, struct sk_buff *skb) | |
816 | { | |
817 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
818 | u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
819 | ||
820 | if (unlikely(before(ssn, subflow->map_subflow_seq))) { | |
821 | /* Mapping covers data later in the subflow stream, | |
822 | * currently unsupported. | |
823 | */ | |
61e71022 | 824 | dbg_bad_map(subflow, ssn); |
648ef4b8 MM |
825 | return false; |
826 | } | |
827 | if (unlikely(!before(ssn, subflow->map_subflow_seq + | |
828 | subflow->map_data_len))) { | |
829 | /* Mapping does covers past subflow data, invalid */ | |
61e71022 | 830 | dbg_bad_map(subflow, ssn); |
648ef4b8 MM |
831 | return false; |
832 | } | |
833 | return true; | |
834 | } | |
835 | ||
dd8bcd17 PA |
836 | static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *skb, |
837 | bool csum_reqd) | |
838 | { | |
839 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
840 | struct csum_pseudo_header header; | |
841 | u32 offset, seq, delta; | |
842 | __wsum csum; | |
843 | int len; | |
844 | ||
845 | if (!csum_reqd) | |
846 | return MAPPING_OK; | |
847 | ||
848 | /* mapping already validated on previous traversal */ | |
849 | if (subflow->map_csum_len == subflow->map_data_len) | |
850 | return MAPPING_OK; | |
851 | ||
852 | /* traverse the receive queue, ensuring it contains a full | |
853 | * DSS mapping and accumulating the related csum. | |
854 | * Preserve the accoumlate csum across multiple calls, to compute | |
855 | * the csum only once | |
856 | */ | |
857 | delta = subflow->map_data_len - subflow->map_csum_len; | |
858 | for (;;) { | |
859 | seq = tcp_sk(ssk)->copied_seq + subflow->map_csum_len; | |
860 | offset = seq - TCP_SKB_CB(skb)->seq; | |
861 | ||
862 | /* if the current skb has not been accounted yet, csum its contents | |
863 | * up to the amount covered by the current DSS | |
864 | */ | |
865 | if (offset < skb->len) { | |
866 | __wsum csum; | |
867 | ||
868 | len = min(skb->len - offset, delta); | |
869 | csum = skb_checksum(skb, offset, len, 0); | |
870 | subflow->map_data_csum = csum_block_add(subflow->map_data_csum, csum, | |
871 | subflow->map_csum_len); | |
872 | ||
873 | delta -= len; | |
874 | subflow->map_csum_len += len; | |
875 | } | |
876 | if (delta == 0) | |
877 | break; | |
878 | ||
879 | if (skb_queue_is_last(&ssk->sk_receive_queue, skb)) { | |
880 | /* if this subflow is closed, the partial mapping | |
881 | * will be never completed; flush the pending skbs, so | |
882 | * that subflow_sched_work_if_closed() can kick in | |
883 | */ | |
884 | if (unlikely(ssk->sk_state == TCP_CLOSE)) | |
885 | while ((skb = skb_peek(&ssk->sk_receive_queue))) | |
886 | sk_eat_skb(ssk, skb); | |
887 | ||
888 | /* not enough data to validate the csum */ | |
889 | return MAPPING_EMPTY; | |
890 | } | |
891 | ||
892 | /* the DSS mapping for next skbs will be validated later, | |
893 | * when a get_mapping_status call will process such skb | |
894 | */ | |
895 | skb = skb->next; | |
896 | } | |
897 | ||
898 | /* note that 'map_data_len' accounts only for the carried data, does | |
899 | * not include the eventual seq increment due to the data fin, | |
900 | * while the pseudo header requires the original DSS data len, | |
901 | * including that | |
902 | */ | |
903 | header.data_seq = cpu_to_be64(subflow->map_seq); | |
904 | header.subflow_seq = htonl(subflow->map_subflow_seq); | |
905 | header.data_len = htons(subflow->map_data_len + subflow->map_data_fin); | |
906 | header.csum = 0; | |
907 | ||
908 | csum = csum_partial(&header, sizeof(header), subflow->map_data_csum); | |
fe3ab1cb GT |
909 | if (unlikely(csum_fold(csum))) { |
910 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR); | |
dd8bcd17 | 911 | return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY; |
fe3ab1cb | 912 | } |
dd8bcd17 PA |
913 | |
914 | return MAPPING_OK; | |
915 | } | |
916 | ||
43b54c6e MM |
917 | static enum mapping_status get_mapping_status(struct sock *ssk, |
918 | struct mptcp_sock *msk) | |
648ef4b8 MM |
919 | { |
920 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
dd8bcd17 | 921 | bool csum_reqd = READ_ONCE(msk->csum_enabled); |
648ef4b8 MM |
922 | struct mptcp_ext *mpext; |
923 | struct sk_buff *skb; | |
924 | u16 data_len; | |
925 | u64 map_seq; | |
926 | ||
927 | skb = skb_peek(&ssk->sk_receive_queue); | |
928 | if (!skb) | |
929 | return MAPPING_EMPTY; | |
930 | ||
e1ff9e82 DC |
931 | if (mptcp_check_fallback(ssk)) |
932 | return MAPPING_DUMMY; | |
933 | ||
648ef4b8 MM |
934 | mpext = mptcp_get_ext(skb); |
935 | if (!mpext || !mpext->use_map) { | |
936 | if (!subflow->map_valid && !skb->len) { | |
937 | /* the TCP stack deliver 0 len FIN pkt to the receive | |
938 | * queue, that is the only 0len pkts ever expected here, | |
939 | * and we can admit no mapping only for 0 len pkts | |
940 | */ | |
941 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) | |
942 | WARN_ONCE(1, "0len seq %d:%d flags %x", | |
943 | TCP_SKB_CB(skb)->seq, | |
944 | TCP_SKB_CB(skb)->end_seq, | |
945 | TCP_SKB_CB(skb)->tcp_flags); | |
946 | sk_eat_skb(ssk, skb); | |
947 | return MAPPING_EMPTY; | |
948 | } | |
949 | ||
950 | if (!subflow->map_valid) | |
951 | return MAPPING_INVALID; | |
952 | ||
953 | goto validate_seq; | |
954 | } | |
955 | ||
0918e34b | 956 | trace_get_mapping_status(mpext); |
648ef4b8 MM |
957 | |
958 | data_len = mpext->data_len; | |
959 | if (data_len == 0) { | |
fc518953 | 960 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); |
648ef4b8 MM |
961 | return MAPPING_INVALID; |
962 | } | |
963 | ||
964 | if (mpext->data_fin == 1) { | |
965 | if (data_len == 1) { | |
1a49b2c2 MM |
966 | bool updated = mptcp_update_rcv_data_fin(msk, mpext->data_seq, |
967 | mpext->dsn64); | |
43b54c6e | 968 | pr_debug("DATA_FIN with no payload seq=%llu", mpext->data_seq); |
648ef4b8 MM |
969 | if (subflow->map_valid) { |
970 | /* A DATA_FIN might arrive in a DSS | |
971 | * option before the previous mapping | |
972 | * has been fully consumed. Continue | |
973 | * handling the existing mapping. | |
974 | */ | |
975 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
976 | return MAPPING_OK; | |
977 | } else { | |
ef59b195 MM |
978 | if (updated && schedule_work(&msk->work)) |
979 | sock_hold((struct sock *)msk); | |
980 | ||
648ef4b8 MM |
981 | return MAPPING_DATA_FIN; |
982 | } | |
43b54c6e | 983 | } else { |
017512a0 | 984 | u64 data_fin_seq = mpext->data_seq + data_len - 1; |
1a49b2c2 MM |
985 | |
986 | /* If mpext->data_seq is a 32-bit value, data_fin_seq | |
987 | * must also be limited to 32 bits. | |
988 | */ | |
989 | if (!mpext->dsn64) | |
990 | data_fin_seq &= GENMASK_ULL(31, 0); | |
991 | ||
992 | mptcp_update_rcv_data_fin(msk, data_fin_seq, mpext->dsn64); | |
993 | pr_debug("DATA_FIN with mapping seq=%llu dsn64=%d", | |
994 | data_fin_seq, mpext->dsn64); | |
648ef4b8 MM |
995 | } |
996 | ||
997 | /* Adjust for DATA_FIN using 1 byte of sequence space */ | |
998 | data_len--; | |
999 | } | |
1000 | ||
5957a890 | 1001 | map_seq = mptcp_expand_seq(READ_ONCE(msk->ack_seq), mpext->data_seq, mpext->dsn64); |
37198e93 | 1002 | WRITE_ONCE(mptcp_sk(subflow->conn)->use_64bit_ack, !!mpext->dsn64); |
648ef4b8 MM |
1003 | |
1004 | if (subflow->map_valid) { | |
1005 | /* Allow replacing only with an identical map */ | |
1006 | if (subflow->map_seq == map_seq && | |
1007 | subflow->map_subflow_seq == mpext->subflow_seq && | |
dd8bcd17 PA |
1008 | subflow->map_data_len == data_len && |
1009 | subflow->map_csum_reqd == mpext->csum_reqd) { | |
648ef4b8 | 1010 | skb_ext_del(skb, SKB_EXT_MPTCP); |
dd8bcd17 | 1011 | goto validate_csum; |
648ef4b8 MM |
1012 | } |
1013 | ||
1014 | /* If this skb data are fully covered by the current mapping, | |
1015 | * the new map would need caching, which is not supported | |
1016 | */ | |
fc518953 FW |
1017 | if (skb_is_fully_mapped(ssk, skb)) { |
1018 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH); | |
648ef4b8 | 1019 | return MAPPING_INVALID; |
fc518953 | 1020 | } |
648ef4b8 MM |
1021 | |
1022 | /* will validate the next map after consuming the current one */ | |
dd8bcd17 | 1023 | goto validate_csum; |
648ef4b8 MM |
1024 | } |
1025 | ||
1026 | subflow->map_seq = map_seq; | |
1027 | subflow->map_subflow_seq = mpext->subflow_seq; | |
1028 | subflow->map_data_len = data_len; | |
1029 | subflow->map_valid = 1; | |
dd8bcd17 | 1030 | subflow->map_data_fin = mpext->data_fin; |
d22f4988 | 1031 | subflow->mpc_map = mpext->mpc_map; |
dd8bcd17 PA |
1032 | subflow->map_csum_reqd = mpext->csum_reqd; |
1033 | subflow->map_csum_len = 0; | |
1034 | subflow->map_data_csum = csum_unfold(mpext->csum); | |
1035 | ||
1036 | /* Cfr RFC 8684 Section 3.3.0 */ | |
1037 | if (unlikely(subflow->map_csum_reqd != csum_reqd)) | |
1038 | return MAPPING_INVALID; | |
1039 | ||
1040 | pr_debug("new map seq=%llu subflow_seq=%u data_len=%u csum=%d:%u", | |
648ef4b8 | 1041 | subflow->map_seq, subflow->map_subflow_seq, |
dd8bcd17 PA |
1042 | subflow->map_data_len, subflow->map_csum_reqd, |
1043 | subflow->map_data_csum); | |
648ef4b8 MM |
1044 | |
1045 | validate_seq: | |
1046 | /* we revalidate valid mapping on new skb, because we must ensure | |
1047 | * the current skb is completely covered by the available mapping | |
1048 | */ | |
06285da9 PA |
1049 | if (!validate_mapping(ssk, skb)) { |
1050 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSTCPMISMATCH); | |
648ef4b8 | 1051 | return MAPPING_INVALID; |
06285da9 | 1052 | } |
648ef4b8 MM |
1053 | |
1054 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
dd8bcd17 PA |
1055 | |
1056 | validate_csum: | |
1057 | return validate_data_csum(ssk, skb, csum_reqd); | |
648ef4b8 MM |
1058 | } |
1059 | ||
04e4cd4f | 1060 | static void mptcp_subflow_discard_data(struct sock *ssk, struct sk_buff *skb, |
1d39cd8c | 1061 | u64 limit) |
6719331c PA |
1062 | { |
1063 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
04e4cd4f PA |
1064 | bool fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; |
1065 | u32 incr; | |
1066 | ||
1067 | incr = limit >= skb->len ? skb->len + fin : limit; | |
1068 | ||
1069 | pr_debug("discarding=%d len=%d seq=%d", incr, skb->len, | |
1070 | subflow->map_subflow_seq); | |
06242e44 | 1071 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DUPDATA); |
04e4cd4f PA |
1072 | tcp_sk(ssk)->copied_seq += incr; |
1073 | if (!before(tcp_sk(ssk)->copied_seq, TCP_SKB_CB(skb)->end_seq)) | |
1074 | sk_eat_skb(ssk, skb); | |
1075 | if (mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) | |
1076 | subflow->map_valid = 0; | |
6719331c PA |
1077 | } |
1078 | ||
40947e13 FW |
1079 | /* sched mptcp worker to remove the subflow if no more data is pending */ |
1080 | static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ssk) | |
1081 | { | |
1082 | struct sock *sk = (struct sock *)msk; | |
1083 | ||
1084 | if (likely(ssk->sk_state != TCP_CLOSE)) | |
1085 | return; | |
1086 | ||
1087 | if (skb_queue_empty(&ssk->sk_receive_queue) && | |
1088 | !test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) { | |
1089 | sock_hold(sk); | |
1090 | if (!schedule_work(&msk->work)) | |
1091 | sock_put(sk); | |
1092 | } | |
1093 | } | |
1094 | ||
648ef4b8 MM |
1095 | static bool subflow_check_data_avail(struct sock *ssk) |
1096 | { | |
1097 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1098 | enum mapping_status status; | |
1099 | struct mptcp_sock *msk; | |
1100 | struct sk_buff *skb; | |
1101 | ||
47bebdf3 | 1102 | if (!skb_peek(&ssk->sk_receive_queue)) |
99d1055c | 1103 | WRITE_ONCE(subflow->data_avail, 0); |
648ef4b8 MM |
1104 | if (subflow->data_avail) |
1105 | return true; | |
1106 | ||
648ef4b8 MM |
1107 | msk = mptcp_sk(subflow->conn); |
1108 | for (;;) { | |
648ef4b8 MM |
1109 | u64 ack_seq; |
1110 | u64 old_ack; | |
1111 | ||
43b54c6e | 1112 | status = get_mapping_status(ssk, msk); |
d96a838a | 1113 | trace_subflow_check_data_avail(status, skb_peek(&ssk->sk_receive_queue)); |
dea2b1ea PA |
1114 | if (unlikely(status == MAPPING_INVALID)) |
1115 | goto fallback; | |
1116 | ||
1117 | if (unlikely(status == MAPPING_DUMMY)) | |
1118 | goto fallback; | |
648ef4b8 MM |
1119 | |
1120 | if (status != MAPPING_OK) | |
40947e13 | 1121 | goto no_data; |
648ef4b8 MM |
1122 | |
1123 | skb = skb_peek(&ssk->sk_receive_queue); | |
1124 | if (WARN_ON_ONCE(!skb)) | |
40947e13 | 1125 | goto no_data; |
648ef4b8 | 1126 | |
d22f4988 CP |
1127 | /* if msk lacks the remote key, this subflow must provide an |
1128 | * MP_CAPABLE-based mapping | |
1129 | */ | |
1130 | if (unlikely(!READ_ONCE(msk->can_ack))) { | |
dea2b1ea PA |
1131 | if (!subflow->mpc_map) |
1132 | goto fallback; | |
d22f4988 CP |
1133 | WRITE_ONCE(msk->remote_key, subflow->remote_key); |
1134 | WRITE_ONCE(msk->ack_seq, subflow->map_seq); | |
1135 | WRITE_ONCE(msk->can_ack, true); | |
1136 | } | |
1137 | ||
648ef4b8 MM |
1138 | old_ack = READ_ONCE(msk->ack_seq); |
1139 | ack_seq = mptcp_subflow_get_mapped_dsn(subflow); | |
1140 | pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, | |
1141 | ack_seq); | |
99d1055c PA |
1142 | if (unlikely(before64(ack_seq, old_ack))) { |
1143 | mptcp_subflow_discard_data(ssk, skb, old_ack - ack_seq); | |
1144 | continue; | |
47bebdf3 | 1145 | } |
648ef4b8 | 1146 | |
99d1055c PA |
1147 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); |
1148 | break; | |
648ef4b8 MM |
1149 | } |
1150 | return true; | |
1151 | ||
40947e13 FW |
1152 | no_data: |
1153 | subflow_sched_work_if_closed(msk, ssk); | |
1154 | return false; | |
dea2b1ea PA |
1155 | |
1156 | fallback: | |
1157 | /* RFC 8684 section 3.7. */ | |
1158 | if (subflow->mp_join || subflow->fully_established) { | |
1159 | /* fatal protocol error, close the socket. | |
1160 | * subflow_error_report() will introduce the appropriate barriers | |
1161 | */ | |
1162 | ssk->sk_err = EBADMSG; | |
dea2b1ea PA |
1163 | tcp_set_state(ssk, TCP_CLOSE); |
1164 | subflow->reset_transient = 0; | |
1165 | subflow->reset_reason = MPTCP_RST_EMPTCP; | |
1166 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
99d1055c | 1167 | WRITE_ONCE(subflow->data_avail, 0); |
dea2b1ea PA |
1168 | return false; |
1169 | } | |
1170 | ||
1171 | __mptcp_do_fallback(msk); | |
1172 | skb = skb_peek(&ssk->sk_receive_queue); | |
1173 | subflow->map_valid = 1; | |
1174 | subflow->map_seq = READ_ONCE(msk->ack_seq); | |
1175 | subflow->map_data_len = skb->len; | |
1176 | subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
99d1055c | 1177 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); |
dea2b1ea | 1178 | return true; |
648ef4b8 MM |
1179 | } |
1180 | ||
1181 | bool mptcp_subflow_data_available(struct sock *sk) | |
1182 | { | |
1183 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
648ef4b8 MM |
1184 | |
1185 | /* check if current mapping is still valid */ | |
1186 | if (subflow->map_valid && | |
1187 | mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) { | |
1188 | subflow->map_valid = 0; | |
99d1055c | 1189 | WRITE_ONCE(subflow->data_avail, 0); |
648ef4b8 MM |
1190 | |
1191 | pr_debug("Done with mapping: seq=%u data_len=%u", | |
1192 | subflow->map_subflow_seq, | |
1193 | subflow->map_data_len); | |
1194 | } | |
1195 | ||
47bebdf3 | 1196 | return subflow_check_data_avail(sk); |
648ef4b8 MM |
1197 | } |
1198 | ||
071c8ed6 FW |
1199 | /* If ssk has an mptcp parent socket, use the mptcp rcvbuf occupancy, |
1200 | * not the ssk one. | |
1201 | * | |
1202 | * In mptcp, rwin is about the mptcp-level connection data. | |
1203 | * | |
1204 | * Data that is still on the ssk rx queue can thus be ignored, | |
55320b82 | 1205 | * as far as mptcp peer is concerned that data is still inflight. |
071c8ed6 FW |
1206 | * DSS ACK is updated when skb is moved to the mptcp rx queue. |
1207 | */ | |
1208 | void mptcp_space(const struct sock *ssk, int *space, int *full_space) | |
1209 | { | |
1210 | const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1211 | const struct sock *sk = subflow->conn; | |
1212 | ||
ea4ca586 | 1213 | *space = __mptcp_space(sk); |
071c8ed6 FW |
1214 | *full_space = tcp_full_space(sk); |
1215 | } | |
1216 | ||
15cc1045 PA |
1217 | void __mptcp_error_report(struct sock *sk) |
1218 | { | |
1219 | struct mptcp_subflow_context *subflow; | |
1220 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1221 | ||
1222 | mptcp_for_each_subflow(msk, subflow) { | |
1223 | struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | |
1224 | int err = sock_error(ssk); | |
1225 | ||
1226 | if (!err) | |
1227 | continue; | |
1228 | ||
1229 | /* only propagate errors on fallen-back sockets or | |
1230 | * on MPC connect | |
1231 | */ | |
1232 | if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(msk)) | |
1233 | continue; | |
1234 | ||
1235 | inet_sk_state_store(sk, inet_sk_state_load(ssk)); | |
1236 | sk->sk_err = -err; | |
1237 | ||
1238 | /* This barrier is coupled with smp_rmb() in mptcp_poll() */ | |
1239 | smp_wmb(); | |
e3ae2365 | 1240 | sk_error_report(sk); |
15cc1045 PA |
1241 | break; |
1242 | } | |
1243 | } | |
1244 | ||
1245 | static void subflow_error_report(struct sock *ssk) | |
1246 | { | |
1247 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1248 | ||
1249 | mptcp_data_lock(sk); | |
1250 | if (!sock_owned_by_user(sk)) | |
1251 | __mptcp_error_report(sk); | |
1252 | else | |
1253 | set_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags); | |
1254 | mptcp_data_unlock(sk); | |
1255 | } | |
1256 | ||
499ada50 PA |
1257 | static void subflow_data_ready(struct sock *sk) |
1258 | { | |
1259 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
1260 | u16 state = 1 << inet_sk_state_load(sk); | |
1261 | struct sock *parent = subflow->conn; | |
1262 | struct mptcp_sock *msk; | |
1263 | ||
1264 | msk = mptcp_sk(parent); | |
1265 | if (state & TCPF_LISTEN) { | |
1266 | /* MPJ subflow are removed from accept queue before reaching here, | |
1267 | * avoid stray wakeups | |
1268 | */ | |
1269 | if (reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue)) | |
1270 | return; | |
1271 | ||
1272 | set_bit(MPTCP_DATA_READY, &msk->flags); | |
1273 | parent->sk_data_ready(parent); | |
1274 | return; | |
1275 | } | |
1276 | ||
1277 | WARN_ON_ONCE(!__mptcp_check_fallback(msk) && !subflow->mp_capable && | |
1278 | !subflow->mp_join && !(state & TCPF_CLOSE)); | |
1279 | ||
1280 | if (mptcp_subflow_data_available(sk)) | |
1281 | mptcp_data_ready(parent, sk); | |
1282 | else if (unlikely(sk->sk_err)) | |
1283 | subflow_error_report(sk); | |
1284 | } | |
1285 | ||
1286 | static void subflow_write_space(struct sock *ssk) | |
1287 | { | |
1288 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1289 | ||
1290 | mptcp_propagate_sndbuf(sk, ssk); | |
1291 | mptcp_write_space(sk); | |
1292 | } | |
1293 | ||
cec37a6e PK |
1294 | static struct inet_connection_sock_af_ops * |
1295 | subflow_default_af_ops(struct sock *sk) | |
1296 | { | |
1297 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1298 | if (sk->sk_family == AF_INET6) | |
1299 | return &subflow_v6_specific; | |
1300 | #endif | |
1301 | return &subflow_specific; | |
1302 | } | |
1303 | ||
cec37a6e | 1304 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
31484d56 GU |
1305 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped) |
1306 | { | |
cec37a6e PK |
1307 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1308 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1309 | struct inet_connection_sock_af_ops *target; | |
1310 | ||
1311 | target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk); | |
1312 | ||
1313 | pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d", | |
edc7e489 | 1314 | subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped); |
cec37a6e PK |
1315 | |
1316 | if (likely(icsk->icsk_af_ops == target)) | |
1317 | return; | |
1318 | ||
1319 | subflow->icsk_af_ops = icsk->icsk_af_ops; | |
1320 | icsk->icsk_af_ops = target; | |
cec37a6e | 1321 | } |
31484d56 | 1322 | #endif |
cec37a6e | 1323 | |
1729cf18 GT |
1324 | void mptcp_info2sockaddr(const struct mptcp_addr_info *info, |
1325 | struct sockaddr_storage *addr, | |
1326 | unsigned short family) | |
ec3edaa7 PK |
1327 | { |
1328 | memset(addr, 0, sizeof(*addr)); | |
50a13bc3 | 1329 | addr->ss_family = family; |
ec3edaa7 PK |
1330 | if (addr->ss_family == AF_INET) { |
1331 | struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; | |
1332 | ||
50a13bc3 MB |
1333 | if (info->family == AF_INET) |
1334 | in_addr->sin_addr = info->addr; | |
1335 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1336 | else if (ipv6_addr_v4mapped(&info->addr6)) | |
1337 | in_addr->sin_addr.s_addr = info->addr6.s6_addr32[3]; | |
1338 | #endif | |
ec3edaa7 PK |
1339 | in_addr->sin_port = info->port; |
1340 | } | |
1341 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1342 | else if (addr->ss_family == AF_INET6) { | |
1343 | struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; | |
1344 | ||
50a13bc3 MB |
1345 | if (info->family == AF_INET) |
1346 | ipv6_addr_set_v4mapped(info->addr.s_addr, | |
1347 | &in6_addr->sin6_addr); | |
1348 | else | |
1349 | in6_addr->sin6_addr = info->addr6; | |
ec3edaa7 PK |
1350 | in6_addr->sin6_port = info->port; |
1351 | } | |
1352 | #endif | |
1353 | } | |
1354 | ||
ef0da3b8 | 1355 | int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, |
daa83ab0 GT |
1356 | const struct mptcp_addr_info *remote, |
1357 | u8 flags, int ifindex) | |
ec3edaa7 PK |
1358 | { |
1359 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1360 | struct mptcp_subflow_context *subflow; | |
1361 | struct sockaddr_storage addr; | |
2ff0e566 | 1362 | int remote_id = remote->id; |
6bad912b | 1363 | int local_id = loc->id; |
ec3edaa7 | 1364 | struct socket *sf; |
6bad912b | 1365 | struct sock *ssk; |
ec3edaa7 PK |
1366 | u32 remote_token; |
1367 | int addrlen; | |
1368 | int err; | |
1369 | ||
b93df08c | 1370 | if (!mptcp_is_fully_established(sk)) |
ec3edaa7 PK |
1371 | return -ENOTCONN; |
1372 | ||
1373 | err = mptcp_subflow_create_socket(sk, &sf); | |
1374 | if (err) | |
1375 | return err; | |
1376 | ||
6bad912b PA |
1377 | ssk = sf->sk; |
1378 | subflow = mptcp_subflow_ctx(ssk); | |
1379 | do { | |
1380 | get_random_bytes(&subflow->local_nonce, sizeof(u32)); | |
1381 | } while (!subflow->local_nonce); | |
1382 | ||
1383 | if (!local_id) { | |
1384 | err = mptcp_pm_get_local_id(msk, (struct sock_common *)ssk); | |
1385 | if (err < 0) | |
1386 | goto failed; | |
1387 | ||
1388 | local_id = err; | |
1389 | } | |
1390 | ||
ec3edaa7 PK |
1391 | subflow->remote_key = msk->remote_key; |
1392 | subflow->local_key = msk->local_key; | |
1393 | subflow->token = msk->token; | |
50a13bc3 | 1394 | mptcp_info2sockaddr(loc, &addr, ssk->sk_family); |
ec3edaa7 PK |
1395 | |
1396 | addrlen = sizeof(struct sockaddr_in); | |
1397 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
50a13bc3 | 1398 | if (addr.ss_family == AF_INET6) |
ec3edaa7 PK |
1399 | addrlen = sizeof(struct sockaddr_in6); |
1400 | #endif | |
daa83ab0 | 1401 | ssk->sk_bound_dev_if = ifindex; |
ec3edaa7 PK |
1402 | err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); |
1403 | if (err) | |
1404 | goto failed; | |
1405 | ||
1406 | mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); | |
2ff0e566 GT |
1407 | pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk, |
1408 | remote_token, local_id, remote_id); | |
ec3edaa7 | 1409 | subflow->remote_token = remote_token; |
6bad912b | 1410 | subflow->local_id = local_id; |
2ff0e566 | 1411 | subflow->remote_id = remote_id; |
ec3edaa7 | 1412 | subflow->request_join = 1; |
daa83ab0 | 1413 | subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP); |
50a13bc3 | 1414 | mptcp_info2sockaddr(remote, &addr, ssk->sk_family); |
ec3edaa7 | 1415 | |
5b950ff4 | 1416 | mptcp_add_pending_subflow(msk, subflow); |
78962489 | 1417 | mptcp_sockopt_sync(msk, ssk); |
ec3edaa7 PK |
1418 | err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); |
1419 | if (err && err != -EINPROGRESS) | |
5b950ff4 | 1420 | goto failed_unlink; |
ec3edaa7 | 1421 | |
866f26f2 PA |
1422 | /* discard the subflow socket */ |
1423 | mptcp_sock_graft(ssk, sk->sk_socket); | |
1424 | iput(SOCK_INODE(sf)); | |
ec3edaa7 PK |
1425 | return err; |
1426 | ||
5b950ff4 | 1427 | failed_unlink: |
ec3edaa7 | 1428 | spin_lock_bh(&msk->join_list_lock); |
5b950ff4 | 1429 | list_del(&subflow->node); |
ec3edaa7 | 1430 | spin_unlock_bh(&msk->join_list_lock); |
f0715779 | 1431 | sock_put(mptcp_subflow_tcp_sock(subflow)); |
ec3edaa7 | 1432 | |
ec3edaa7 | 1433 | failed: |
e16163b6 | 1434 | subflow->disposable = 1; |
ec3edaa7 PK |
1435 | sock_release(sf); |
1436 | return err; | |
1437 | } | |
1438 | ||
3764b0c5 NR |
1439 | static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) |
1440 | { | |
1441 | #ifdef CONFIG_SOCK_CGROUP_DATA | |
1442 | struct sock_cgroup_data *parent_skcd = &parent->sk_cgrp_data, | |
1443 | *child_skcd = &child->sk_cgrp_data; | |
1444 | ||
1445 | /* only the additional subflows created by kworkers have to be modified */ | |
1446 | if (cgroup_id(sock_cgroup_ptr(parent_skcd)) != | |
1447 | cgroup_id(sock_cgroup_ptr(child_skcd))) { | |
1448 | #ifdef CONFIG_MEMCG | |
1449 | struct mem_cgroup *memcg = parent->sk_memcg; | |
1450 | ||
1451 | mem_cgroup_sk_free(child); | |
1452 | if (memcg && css_tryget(&memcg->css)) | |
1453 | child->sk_memcg = memcg; | |
1454 | #endif /* CONFIG_MEMCG */ | |
1455 | ||
1456 | cgroup_sk_free(child_skcd); | |
1457 | *child_skcd = *parent_skcd; | |
1458 | cgroup_sk_clone(child_skcd); | |
1459 | } | |
1460 | #endif /* CONFIG_SOCK_CGROUP_DATA */ | |
1461 | } | |
1462 | ||
b19bc294 PA |
1463 | static void mptcp_subflow_ops_override(struct sock *ssk) |
1464 | { | |
1465 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1466 | if (ssk->sk_prot == &tcpv6_prot) | |
1467 | ssk->sk_prot = &tcpv6_prot_override; | |
1468 | else | |
1469 | #endif | |
1470 | ssk->sk_prot = &tcp_prot_override; | |
1471 | } | |
1472 | ||
1473 | static void mptcp_subflow_ops_undo_override(struct sock *ssk) | |
1474 | { | |
1475 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1476 | if (ssk->sk_prot == &tcpv6_prot_override) | |
1477 | ssk->sk_prot = &tcpv6_prot; | |
1478 | else | |
1479 | #endif | |
1480 | ssk->sk_prot = &tcp_prot; | |
1481 | } | |
2303f994 PK |
1482 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) |
1483 | { | |
1484 | struct mptcp_subflow_context *subflow; | |
1485 | struct net *net = sock_net(sk); | |
1486 | struct socket *sf; | |
1487 | int err; | |
1488 | ||
adf73410 PA |
1489 | /* un-accepted server sockets can reach here - on bad configuration |
1490 | * bail early to avoid greater trouble later | |
1491 | */ | |
1492 | if (unlikely(!sk->sk_socket)) | |
1493 | return -EINVAL; | |
1494 | ||
cec37a6e PK |
1495 | err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP, |
1496 | &sf); | |
2303f994 PK |
1497 | if (err) |
1498 | return err; | |
1499 | ||
1500 | lock_sock(sf->sk); | |
1501 | ||
3764b0c5 NR |
1502 | /* the newly created socket has to be in the same cgroup as its parent */ |
1503 | mptcp_attach_cgroup(sk, sf->sk); | |
1504 | ||
2303f994 PK |
1505 | /* kernel sockets do not by default acquire net ref, but TCP timer |
1506 | * needs it. | |
1507 | */ | |
1508 | sf->sk->sk_net_refcnt = 1; | |
1509 | get_net(net); | |
f6f7d8cf | 1510 | #ifdef CONFIG_PROC_FS |
2303f994 | 1511 | this_cpu_add(*net->core.sock_inuse, 1); |
f6f7d8cf | 1512 | #endif |
2303f994 PK |
1513 | err = tcp_set_ulp(sf->sk, "mptcp"); |
1514 | release_sock(sf->sk); | |
1515 | ||
b8ad540d WY |
1516 | if (err) { |
1517 | sock_release(sf); | |
2303f994 | 1518 | return err; |
b8ad540d | 1519 | } |
2303f994 | 1520 | |
7d14b0d2 PA |
1521 | /* the newly created socket really belongs to the owning MPTCP master |
1522 | * socket, even if for additional subflows the allocation is performed | |
1523 | * by a kernel workqueue. Adjust inode references, so that the | |
1524 | * procfs/diag interaces really show this one belonging to the correct | |
1525 | * user. | |
1526 | */ | |
1527 | SOCK_INODE(sf)->i_ino = SOCK_INODE(sk->sk_socket)->i_ino; | |
1528 | SOCK_INODE(sf)->i_uid = SOCK_INODE(sk->sk_socket)->i_uid; | |
1529 | SOCK_INODE(sf)->i_gid = SOCK_INODE(sk->sk_socket)->i_gid; | |
1530 | ||
2303f994 PK |
1531 | subflow = mptcp_subflow_ctx(sf->sk); |
1532 | pr_debug("subflow=%p", subflow); | |
1533 | ||
1534 | *new_sock = sf; | |
79c0949e | 1535 | sock_hold(sk); |
2303f994 | 1536 | subflow->conn = sk; |
b19bc294 | 1537 | mptcp_subflow_ops_override(sf->sk); |
2303f994 PK |
1538 | |
1539 | return 0; | |
1540 | } | |
1541 | ||
1542 | static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, | |
1543 | gfp_t priority) | |
1544 | { | |
1545 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1546 | struct mptcp_subflow_context *ctx; | |
1547 | ||
1548 | ctx = kzalloc(sizeof(*ctx), priority); | |
1549 | if (!ctx) | |
1550 | return NULL; | |
1551 | ||
1552 | rcu_assign_pointer(icsk->icsk_ulp_data, ctx); | |
cec37a6e | 1553 | INIT_LIST_HEAD(&ctx->node); |
b19bc294 | 1554 | INIT_LIST_HEAD(&ctx->delegated_node); |
2303f994 PK |
1555 | |
1556 | pr_debug("subflow=%p", ctx); | |
1557 | ||
1558 | ctx->tcp_sock = sk; | |
1559 | ||
1560 | return ctx; | |
1561 | } | |
1562 | ||
648ef4b8 MM |
1563 | static void __subflow_state_change(struct sock *sk) |
1564 | { | |
1565 | struct socket_wq *wq; | |
1566 | ||
1567 | rcu_read_lock(); | |
1568 | wq = rcu_dereference(sk->sk_wq); | |
1569 | if (skwq_has_sleeper(wq)) | |
1570 | wake_up_interruptible_all(&wq->wait); | |
1571 | rcu_read_unlock(); | |
1572 | } | |
1573 | ||
1574 | static bool subflow_is_done(const struct sock *sk) | |
1575 | { | |
1576 | return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE; | |
1577 | } | |
1578 | ||
1579 | static void subflow_state_change(struct sock *sk) | |
1580 | { | |
1581 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
dc093db5 | 1582 | struct sock *parent = subflow->conn; |
648ef4b8 MM |
1583 | |
1584 | __subflow_state_change(sk); | |
1585 | ||
8fd73804 | 1586 | if (subflow_simultaneous_connect(sk)) { |
5cf92bba | 1587 | mptcp_propagate_sndbuf(parent, sk); |
8fd73804 | 1588 | mptcp_do_fallback(sk); |
a6b118fe | 1589 | mptcp_rcv_space_init(mptcp_sk(parent), sk); |
8fd73804 DC |
1590 | pr_fallback(mptcp_sk(parent)); |
1591 | subflow->conn_finished = 1; | |
490274b4 | 1592 | mptcp_set_connected(parent); |
8fd73804 DC |
1593 | } |
1594 | ||
648ef4b8 MM |
1595 | /* as recvmsg() does not acquire the subflow socket for ssk selection |
1596 | * a fin packet carrying a DSS can be unnoticed if we don't trigger | |
1597 | * the data available machinery here. | |
1598 | */ | |
e1ff9e82 | 1599 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 1600 | mptcp_data_ready(parent, sk); |
499ada50 PA |
1601 | else if (unlikely(sk->sk_err)) |
1602 | subflow_error_report(sk); | |
648ef4b8 | 1603 | |
40947e13 FW |
1604 | subflow_sched_work_if_closed(mptcp_sk(parent), sk); |
1605 | ||
067a0b3d | 1606 | if (__mptcp_check_fallback(mptcp_sk(parent)) && |
648ef4b8 MM |
1607 | !subflow->rx_eof && subflow_is_done(sk)) { |
1608 | subflow->rx_eof = 1; | |
59832e24 | 1609 | mptcp_subflow_eof(parent); |
648ef4b8 MM |
1610 | } |
1611 | } | |
1612 | ||
2303f994 PK |
1613 | static int subflow_ulp_init(struct sock *sk) |
1614 | { | |
cec37a6e | 1615 | struct inet_connection_sock *icsk = inet_csk(sk); |
2303f994 PK |
1616 | struct mptcp_subflow_context *ctx; |
1617 | struct tcp_sock *tp = tcp_sk(sk); | |
1618 | int err = 0; | |
1619 | ||
1620 | /* disallow attaching ULP to a socket unless it has been | |
1621 | * created with sock_create_kern() | |
1622 | */ | |
1623 | if (!sk->sk_kern_sock) { | |
1624 | err = -EOPNOTSUPP; | |
1625 | goto out; | |
1626 | } | |
1627 | ||
1628 | ctx = subflow_create_ctx(sk, GFP_KERNEL); | |
1629 | if (!ctx) { | |
1630 | err = -ENOMEM; | |
1631 | goto out; | |
1632 | } | |
1633 | ||
1634 | pr_debug("subflow=%p, family=%d", ctx, sk->sk_family); | |
1635 | ||
1636 | tp->is_mptcp = 1; | |
cec37a6e PK |
1637 | ctx->icsk_af_ops = icsk->icsk_af_ops; |
1638 | icsk->icsk_af_ops = subflow_default_af_ops(sk); | |
648ef4b8 MM |
1639 | ctx->tcp_data_ready = sk->sk_data_ready; |
1640 | ctx->tcp_state_change = sk->sk_state_change; | |
1641 | ctx->tcp_write_space = sk->sk_write_space; | |
15cc1045 | 1642 | ctx->tcp_error_report = sk->sk_error_report; |
648ef4b8 MM |
1643 | sk->sk_data_ready = subflow_data_ready; |
1644 | sk->sk_write_space = subflow_write_space; | |
1645 | sk->sk_state_change = subflow_state_change; | |
15cc1045 | 1646 | sk->sk_error_report = subflow_error_report; |
2303f994 PK |
1647 | out: |
1648 | return err; | |
1649 | } | |
1650 | ||
e16163b6 | 1651 | static void subflow_ulp_release(struct sock *ssk) |
2303f994 | 1652 | { |
e16163b6 PA |
1653 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); |
1654 | bool release = true; | |
1655 | struct sock *sk; | |
2303f994 PK |
1656 | |
1657 | if (!ctx) | |
1658 | return; | |
1659 | ||
e16163b6 PA |
1660 | sk = ctx->conn; |
1661 | if (sk) { | |
1662 | /* if the msk has been orphaned, keep the ctx | |
0597d0f8 PA |
1663 | * alive, will be freed by __mptcp_close_ssk(), |
1664 | * when the subflow is still unaccepted | |
e16163b6 | 1665 | */ |
0597d0f8 | 1666 | release = ctx->disposable || list_empty(&ctx->node); |
e16163b6 PA |
1667 | sock_put(sk); |
1668 | } | |
79c0949e | 1669 | |
b19bc294 | 1670 | mptcp_subflow_ops_undo_override(ssk); |
e16163b6 PA |
1671 | if (release) |
1672 | kfree_rcu(ctx, rcu); | |
2303f994 PK |
1673 | } |
1674 | ||
cec37a6e PK |
1675 | static void subflow_ulp_clone(const struct request_sock *req, |
1676 | struct sock *newsk, | |
1677 | const gfp_t priority) | |
1678 | { | |
1679 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
1680 | struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk); | |
1681 | struct mptcp_subflow_context *new_ctx; | |
1682 | ||
f296234c PK |
1683 | if (!tcp_rsk(req)->is_mptcp || |
1684 | (!subflow_req->mp_capable && !subflow_req->mp_join)) { | |
648ef4b8 | 1685 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1686 | return; |
1687 | } | |
1688 | ||
1689 | new_ctx = subflow_create_ctx(newsk, priority); | |
edc7e489 | 1690 | if (!new_ctx) { |
648ef4b8 | 1691 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1692 | return; |
1693 | } | |
1694 | ||
1695 | new_ctx->conn_finished = 1; | |
1696 | new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; | |
648ef4b8 MM |
1697 | new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; |
1698 | new_ctx->tcp_state_change = old_ctx->tcp_state_change; | |
1699 | new_ctx->tcp_write_space = old_ctx->tcp_write_space; | |
15cc1045 | 1700 | new_ctx->tcp_error_report = old_ctx->tcp_error_report; |
58b09919 PA |
1701 | new_ctx->rel_write_seq = 1; |
1702 | new_ctx->tcp_sock = newsk; | |
1703 | ||
f296234c PK |
1704 | if (subflow_req->mp_capable) { |
1705 | /* see comments in subflow_syn_recv_sock(), MPTCP connection | |
1706 | * is fully established only after we receive the remote key | |
1707 | */ | |
1708 | new_ctx->mp_capable = 1; | |
f296234c PK |
1709 | new_ctx->local_key = subflow_req->local_key; |
1710 | new_ctx->token = subflow_req->token; | |
1711 | new_ctx->ssn_offset = subflow_req->ssn_offset; | |
1712 | new_ctx->idsn = subflow_req->idsn; | |
1713 | } else if (subflow_req->mp_join) { | |
ec3edaa7 | 1714 | new_ctx->ssn_offset = subflow_req->ssn_offset; |
f296234c PK |
1715 | new_ctx->mp_join = 1; |
1716 | new_ctx->fully_established = 1; | |
1717 | new_ctx->backup = subflow_req->backup; | |
1718 | new_ctx->local_id = subflow_req->local_id; | |
2ff0e566 | 1719 | new_ctx->remote_id = subflow_req->remote_id; |
f296234c PK |
1720 | new_ctx->token = subflow_req->token; |
1721 | new_ctx->thmac = subflow_req->thmac; | |
1722 | } | |
cec37a6e PK |
1723 | } |
1724 | ||
b19bc294 PA |
1725 | static void tcp_release_cb_override(struct sock *ssk) |
1726 | { | |
1727 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1728 | ||
1729 | if (mptcp_subflow_has_delegated_action(subflow)) | |
1730 | mptcp_subflow_process_delegated(ssk); | |
1731 | ||
1732 | tcp_release_cb(ssk); | |
1733 | } | |
1734 | ||
2303f994 PK |
1735 | static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { |
1736 | .name = "mptcp", | |
1737 | .owner = THIS_MODULE, | |
1738 | .init = subflow_ulp_init, | |
1739 | .release = subflow_ulp_release, | |
cec37a6e | 1740 | .clone = subflow_ulp_clone, |
2303f994 PK |
1741 | }; |
1742 | ||
cec37a6e PK |
1743 | static int subflow_ops_init(struct request_sock_ops *subflow_ops) |
1744 | { | |
1745 | subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock); | |
1746 | subflow_ops->slab_name = "request_sock_subflow"; | |
1747 | ||
1748 | subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name, | |
1749 | subflow_ops->obj_size, 0, | |
1750 | SLAB_ACCOUNT | | |
1751 | SLAB_TYPESAFE_BY_RCU, | |
1752 | NULL); | |
1753 | if (!subflow_ops->slab) | |
1754 | return -ENOMEM; | |
1755 | ||
79c0949e PK |
1756 | subflow_ops->destructor = subflow_req_destructor; |
1757 | ||
cec37a6e PK |
1758 | return 0; |
1759 | } | |
1760 | ||
d39dceca | 1761 | void __init mptcp_subflow_init(void) |
2303f994 | 1762 | { |
08b8d080 FW |
1763 | mptcp_subflow_request_sock_ops = tcp_request_sock_ops; |
1764 | if (subflow_ops_init(&mptcp_subflow_request_sock_ops) != 0) | |
cec37a6e PK |
1765 | panic("MPTCP: failed to init subflow request sock ops\n"); |
1766 | ||
1767 | subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops; | |
7ea851d1 | 1768 | subflow_request_sock_ipv4_ops.route_req = subflow_v4_route_req; |
cec37a6e PK |
1769 | |
1770 | subflow_specific = ipv4_specific; | |
1771 | subflow_specific.conn_request = subflow_v4_conn_request; | |
1772 | subflow_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1773 | subflow_specific.sk_rx_dst_set = subflow_finish_connect; | |
1774 | ||
b19bc294 PA |
1775 | tcp_prot_override = tcp_prot; |
1776 | tcp_prot_override.release_cb = tcp_release_cb_override; | |
1777 | ||
cec37a6e PK |
1778 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
1779 | subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; | |
7ea851d1 | 1780 | subflow_request_sock_ipv6_ops.route_req = subflow_v6_route_req; |
cec37a6e PK |
1781 | |
1782 | subflow_v6_specific = ipv6_specific; | |
1783 | subflow_v6_specific.conn_request = subflow_v6_conn_request; | |
1784 | subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1785 | subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect; | |
1786 | ||
1787 | subflow_v6m_specific = subflow_v6_specific; | |
1788 | subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit; | |
1789 | subflow_v6m_specific.send_check = ipv4_specific.send_check; | |
1790 | subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; | |
1791 | subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; | |
1792 | subflow_v6m_specific.net_frag_header_len = 0; | |
b19bc294 PA |
1793 | |
1794 | tcpv6_prot_override = tcpv6_prot; | |
1795 | tcpv6_prot_override.release_cb = tcp_release_cb_override; | |
cec37a6e PK |
1796 | #endif |
1797 | ||
5147dfb5 DC |
1798 | mptcp_diag_subflow_init(&subflow_ulp_ops); |
1799 | ||
2303f994 PK |
1800 | if (tcp_register_ulp(&subflow_ulp_ops) != 0) |
1801 | panic("MPTCP: failed to register subflows to ULP\n"); | |
1802 | } |