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)) { | |
217 | sock_put((struct sock *)subflow_req->msk); | |
218 | mptcp_token_destroy_request(req); | |
219 | tcp_request_sock_ops.destructor(req); | |
220 | subflow_req->msk = NULL; | |
221 | subflow_req->mp_join = 0; | |
2fbdd9ea | 222 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTSYNRX); |
5bc56388 GT |
223 | return -EPERM; |
224 | } | |
2fbdd9ea | 225 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINPORTSYNRX); |
5bc56388 GT |
226 | } |
227 | ||
ec20e143 GT |
228 | subflow_req_create_thmac(subflow_req); |
229 | ||
3ecfbe3e | 230 | if (unlikely(req->syncookie)) { |
9466a1cc FW |
231 | if (mptcp_can_accept_new_subflow(subflow_req->msk)) |
232 | subflow_init_req_cookie_join_save(subflow_req, skb); | |
233 | } | |
234 | ||
8fd4de12 PA |
235 | pr_debug("token=%u, remote_nonce=%u msk=%p", subflow_req->token, |
236 | subflow_req->remote_nonce, subflow_req->msk); | |
cec37a6e | 237 | } |
3ecfbe3e FW |
238 | |
239 | return 0; | |
cec37a6e PK |
240 | } |
241 | ||
c83a47e5 FW |
242 | int mptcp_subflow_init_cookie_req(struct request_sock *req, |
243 | const struct sock *sk_listener, | |
244 | struct sk_buff *skb) | |
245 | { | |
246 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
247 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
248 | struct mptcp_options_received mp_opt; | |
249 | int err; | |
250 | ||
d8b59efa | 251 | subflow_init_req(req, sk_listener); |
c863225b | 252 | mptcp_get_options(sk_listener, skb, &mp_opt); |
c83a47e5 FW |
253 | |
254 | if (mp_opt.mp_capable && mp_opt.mp_join) | |
255 | return -EINVAL; | |
256 | ||
257 | if (mp_opt.mp_capable && listener->request_mptcp) { | |
258 | if (mp_opt.sndr_key == 0) | |
259 | return -EINVAL; | |
260 | ||
261 | subflow_req->local_key = mp_opt.rcvr_key; | |
262 | err = mptcp_token_new_request(req); | |
263 | if (err) | |
264 | return err; | |
265 | ||
266 | subflow_req->mp_capable = 1; | |
267 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
9466a1cc FW |
268 | } else if (mp_opt.mp_join && listener->request_mptcp) { |
269 | if (!mptcp_token_join_cookie_init_state(subflow_req, skb)) | |
270 | return -EINVAL; | |
271 | ||
272 | if (mptcp_can_accept_new_subflow(subflow_req->msk)) | |
273 | subflow_req->mp_join = 1; | |
274 | ||
275 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
c83a47e5 FW |
276 | } |
277 | ||
278 | return 0; | |
279 | } | |
280 | EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); | |
281 | ||
7ea851d1 FW |
282 | static struct dst_entry *subflow_v4_route_req(const struct sock *sk, |
283 | struct sk_buff *skb, | |
284 | struct flowi *fl, | |
285 | struct request_sock *req) | |
cec37a6e | 286 | { |
7ea851d1 | 287 | struct dst_entry *dst; |
3ecfbe3e | 288 | int err; |
7ea851d1 | 289 | |
cec37a6e | 290 | tcp_rsk(req)->is_mptcp = 1; |
d8b59efa | 291 | subflow_init_req(req, sk); |
cec37a6e | 292 | |
7ea851d1 FW |
293 | dst = tcp_request_sock_ipv4_ops.route_req(sk, skb, fl, req); |
294 | if (!dst) | |
295 | return NULL; | |
cec37a6e | 296 | |
d8b59efa | 297 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
298 | if (err == 0) |
299 | return dst; | |
cec37a6e | 300 | |
3ecfbe3e FW |
301 | dst_release(dst); |
302 | if (!req->syncookie) | |
303 | tcp_request_sock_ops.send_reset(sk, skb); | |
304 | return NULL; | |
cec37a6e PK |
305 | } |
306 | ||
307 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
7ea851d1 FW |
308 | static struct dst_entry *subflow_v6_route_req(const struct sock *sk, |
309 | struct sk_buff *skb, | |
310 | struct flowi *fl, | |
311 | struct request_sock *req) | |
cec37a6e | 312 | { |
7ea851d1 | 313 | struct dst_entry *dst; |
3ecfbe3e | 314 | int err; |
7ea851d1 | 315 | |
cec37a6e | 316 | tcp_rsk(req)->is_mptcp = 1; |
d8b59efa | 317 | subflow_init_req(req, sk); |
cec37a6e | 318 | |
7ea851d1 FW |
319 | dst = tcp_request_sock_ipv6_ops.route_req(sk, skb, fl, req); |
320 | if (!dst) | |
321 | return NULL; | |
cec37a6e | 322 | |
d8b59efa | 323 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
324 | if (err == 0) |
325 | return dst; | |
326 | ||
327 | dst_release(dst); | |
328 | if (!req->syncookie) | |
329 | tcp6_request_sock_ops.send_reset(sk, skb); | |
330 | return NULL; | |
cec37a6e PK |
331 | } |
332 | #endif | |
333 | ||
ec3edaa7 PK |
334 | /* validate received truncated hmac and create hmac for third ACK */ |
335 | static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) | |
336 | { | |
bd697222 | 337 | u8 hmac[SHA256_DIGEST_SIZE]; |
ec3edaa7 PK |
338 | u64 thmac; |
339 | ||
340 | subflow_generate_hmac(subflow->remote_key, subflow->local_key, | |
341 | subflow->remote_nonce, subflow->local_nonce, | |
342 | hmac); | |
343 | ||
344 | thmac = get_unaligned_be64(hmac); | |
345 | pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", | |
346 | subflow, subflow->token, | |
347 | (unsigned long long)thmac, | |
348 | (unsigned long long)subflow->thmac); | |
349 | ||
350 | return thmac == subflow->thmac; | |
351 | } | |
352 | ||
d5824847 PA |
353 | void mptcp_subflow_reset(struct sock *ssk) |
354 | { | |
0e4f35d7 PA |
355 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); |
356 | struct sock *sk = subflow->conn; | |
357 | ||
ab82e996 FW |
358 | /* must hold: tcp_done() could drop last reference on parent */ |
359 | sock_hold(sk); | |
360 | ||
d5824847 PA |
361 | tcp_set_state(ssk, TCP_CLOSE); |
362 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
363 | tcp_done(ssk); | |
0e4f35d7 PA |
364 | if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && |
365 | schedule_work(&mptcp_sk(sk)->work)) | |
ab82e996 FW |
366 | return; /* worker will put sk for us */ |
367 | ||
368 | sock_put(sk); | |
d5824847 PA |
369 | } |
370 | ||
5bc56388 GT |
371 | static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct sock *sk) |
372 | { | |
373 | return inet_sk(sk)->inet_dport != inet_sk((struct sock *)msk)->inet_dport; | |
374 | } | |
375 | ||
cec37a6e PK |
376 | static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) |
377 | { | |
378 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cfde141e | 379 | struct mptcp_options_received mp_opt; |
c3c123d1 | 380 | struct sock *parent = subflow->conn; |
cec37a6e PK |
381 | |
382 | subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); | |
383 | ||
1200832c | 384 | if (inet_sk_state_load(parent) == TCP_SYN_SENT) { |
c3c123d1 DC |
385 | inet_sk_state_store(parent, TCP_ESTABLISHED); |
386 | parent->sk_state_change(parent); | |
387 | } | |
388 | ||
263e1201 PA |
389 | /* be sure no special action on any packet other than syn-ack */ |
390 | if (subflow->conn_finished) | |
391 | return; | |
392 | ||
5cf92bba | 393 | mptcp_propagate_sndbuf(parent, sk); |
b0977bb2 | 394 | subflow->rel_write_seq = 1; |
263e1201 | 395 | subflow->conn_finished = 1; |
e1ff9e82 DC |
396 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; |
397 | pr_debug("subflow=%p synack seq=%x", subflow, subflow->ssn_offset); | |
263e1201 | 398 | |
c863225b | 399 | mptcp_get_options(sk, skb, &mp_opt); |
fa25e815 PA |
400 | if (subflow->request_mptcp) { |
401 | if (!mp_opt.mp_capable) { | |
402 | MPTCP_INC_STATS(sock_net(sk), | |
403 | MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); | |
404 | mptcp_do_fallback(sk); | |
405 | pr_fallback(mptcp_sk(subflow->conn)); | |
406 | goto fallback; | |
407 | } | |
408 | ||
06251181 GT |
409 | if (mp_opt.csum_reqd) |
410 | WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true); | |
df377be3 GT |
411 | if (mp_opt.deny_join_id0) |
412 | WRITE_ONCE(mptcp_sk(parent)->pm.remote_deny_join_id0, true); | |
263e1201 PA |
413 | subflow->mp_capable = 1; |
414 | subflow->can_ack = 1; | |
cfde141e | 415 | subflow->remote_key = mp_opt.sndr_key; |
263e1201 PA |
416 | pr_debug("subflow=%p, remote_key=%llu", subflow, |
417 | subflow->remote_key); | |
5695eb88 | 418 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEACK); |
fa25e815 PA |
419 | mptcp_finish_connect(sk); |
420 | } else if (subflow->request_join) { | |
421 | u8 hmac[SHA256_DIGEST_SIZE]; | |
422 | ||
dc87efdb FW |
423 | if (!mp_opt.mp_join) { |
424 | subflow->reset_reason = MPTCP_RST_EMPTCP; | |
fa25e815 | 425 | goto do_reset; |
dc87efdb | 426 | } |
fa25e815 | 427 | |
cfde141e PA |
428 | subflow->thmac = mp_opt.thmac; |
429 | subflow->remote_nonce = mp_opt.nonce; | |
263e1201 PA |
430 | pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, |
431 | subflow->thmac, subflow->remote_nonce); | |
263e1201 | 432 | |
ec3edaa7 | 433 | if (!subflow_thmac_valid(subflow)) { |
fc518953 | 434 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC); |
dc87efdb | 435 | subflow->reset_reason = MPTCP_RST_EMPTCP; |
ec3edaa7 PK |
436 | goto do_reset; |
437 | } | |
438 | ||
0a4d8e96 JW |
439 | if (!mptcp_finish_join(sk)) |
440 | goto do_reset; | |
441 | ||
ec3edaa7 PK |
442 | subflow_generate_hmac(subflow->local_key, subflow->remote_key, |
443 | subflow->local_nonce, | |
444 | subflow->remote_nonce, | |
bd697222 | 445 | hmac); |
bd697222 | 446 | memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN); |
ec3edaa7 | 447 | |
fa25e815 | 448 | subflow->mp_join = 1; |
fc518953 | 449 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); |
5bc56388 GT |
450 | |
451 | if (subflow_use_different_dport(mptcp_sk(parent), sk)) { | |
452 | pr_debug("synack inet_dport=%d %d", | |
453 | ntohs(inet_sk(sk)->inet_dport), | |
454 | ntohs(inet_sk(parent)->inet_dport)); | |
2fbdd9ea | 455 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINPORTSYNACKRX); |
5bc56388 | 456 | } |
fa25e815 PA |
457 | } else if (mptcp_check_fallback(sk)) { |
458 | fallback: | |
459 | mptcp_rcv_space_init(mptcp_sk(parent), sk); | |
cec37a6e | 460 | } |
fa25e815 PA |
461 | return; |
462 | ||
463 | do_reset: | |
dc87efdb | 464 | subflow->reset_transient = 0; |
d5824847 | 465 | mptcp_subflow_reset(sk); |
cec37a6e PK |
466 | } |
467 | ||
08b8d080 FW |
468 | struct request_sock_ops mptcp_subflow_request_sock_ops; |
469 | EXPORT_SYMBOL_GPL(mptcp_subflow_request_sock_ops); | |
cec37a6e PK |
470 | static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops; |
471 | ||
472 | static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
473 | { | |
474 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
475 | ||
476 | pr_debug("subflow=%p", subflow); | |
477 | ||
478 | /* Never answer to SYNs sent to broadcast or multicast */ | |
479 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
480 | goto drop; | |
481 | ||
08b8d080 | 482 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
483 | &subflow_request_sock_ipv4_ops, |
484 | sk, skb); | |
485 | drop: | |
486 | tcp_listendrop(sk); | |
487 | return 0; | |
488 | } | |
489 | ||
490 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
491 | static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; | |
492 | static struct inet_connection_sock_af_ops subflow_v6_specific; | |
493 | static struct inet_connection_sock_af_ops subflow_v6m_specific; | |
b19bc294 | 494 | static struct proto tcpv6_prot_override; |
cec37a6e PK |
495 | |
496 | static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) | |
497 | { | |
498 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
499 | ||
500 | pr_debug("subflow=%p", subflow); | |
501 | ||
502 | if (skb->protocol == htons(ETH_P_IP)) | |
503 | return subflow_v4_conn_request(sk, skb); | |
504 | ||
505 | if (!ipv6_unicast_destination(skb)) | |
506 | goto drop; | |
507 | ||
dcc32f4f JK |
508 | if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { |
509 | __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); | |
510 | return 0; | |
511 | } | |
512 | ||
08b8d080 | 513 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
514 | &subflow_request_sock_ipv6_ops, sk, skb); |
515 | ||
516 | drop: | |
517 | tcp_listendrop(sk); | |
518 | return 0; /* don't send reset */ | |
519 | } | |
520 | #endif | |
521 | ||
f296234c PK |
522 | /* validate hmac received in third ACK */ |
523 | static bool subflow_hmac_valid(const struct request_sock *req, | |
cfde141e | 524 | const struct mptcp_options_received *mp_opt) |
f296234c PK |
525 | { |
526 | const struct mptcp_subflow_request_sock *subflow_req; | |
bd697222 | 527 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c | 528 | struct mptcp_sock *msk; |
f296234c PK |
529 | |
530 | subflow_req = mptcp_subflow_rsk(req); | |
8fd4de12 | 531 | msk = subflow_req->msk; |
f296234c PK |
532 | if (!msk) |
533 | return false; | |
534 | ||
535 | subflow_generate_hmac(msk->remote_key, msk->local_key, | |
536 | subflow_req->remote_nonce, | |
537 | subflow_req->local_nonce, hmac); | |
538 | ||
8fd4de12 | 539 | return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN); |
f296234c PK |
540 | } |
541 | ||
df1036da FW |
542 | static void mptcp_sock_destruct(struct sock *sk) |
543 | { | |
544 | /* if new mptcp socket isn't accepted, it is free'd | |
545 | * from the tcp listener sockets request queue, linked | |
546 | * from req->sk. The tcp socket is released. | |
547 | * This calls the ULP release function which will | |
548 | * also remove the mptcp socket, via | |
549 | * sock_put(ctx->conn). | |
550 | * | |
7ee24926 PA |
551 | * Problem is that the mptcp socket will be in |
552 | * ESTABLISHED state and will not have the SOCK_DEAD flag. | |
df1036da FW |
553 | * Both result in warnings from inet_sock_destruct. |
554 | */ | |
578c18ef | 555 | if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { |
df1036da FW |
556 | sk->sk_state = TCP_CLOSE; |
557 | WARN_ON_ONCE(sk->sk_socket); | |
558 | sock_orphan(sk); | |
559 | } | |
560 | ||
5c8c1640 | 561 | mptcp_destroy_common(mptcp_sk(sk)); |
df1036da FW |
562 | inet_sock_destruct(sk); |
563 | } | |
564 | ||
9f5ca6a5 FW |
565 | static void mptcp_force_close(struct sock *sk) |
566 | { | |
567 | inet_sk_state_store(sk, TCP_CLOSE); | |
568 | sk_common_release(sk); | |
569 | } | |
570 | ||
4c8941de PA |
571 | static void subflow_ulp_fallback(struct sock *sk, |
572 | struct mptcp_subflow_context *old_ctx) | |
573 | { | |
574 | struct inet_connection_sock *icsk = inet_csk(sk); | |
575 | ||
576 | mptcp_subflow_tcp_fallback(sk, old_ctx); | |
577 | icsk->icsk_ulp_ops = NULL; | |
578 | rcu_assign_pointer(icsk->icsk_ulp_data, NULL); | |
579 | tcp_sk(sk)->is_mptcp = 0; | |
b19bc294 PA |
580 | |
581 | mptcp_subflow_ops_undo_override(sk); | |
4c8941de PA |
582 | } |
583 | ||
39884604 PA |
584 | static void subflow_drop_ctx(struct sock *ssk) |
585 | { | |
586 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); | |
587 | ||
588 | if (!ctx) | |
589 | return; | |
590 | ||
591 | subflow_ulp_fallback(ssk, ctx); | |
592 | if (ctx->conn) | |
593 | sock_put(ctx->conn); | |
594 | ||
595 | kfree_rcu(ctx, rcu); | |
596 | } | |
597 | ||
b93df08c PA |
598 | void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, |
599 | struct mptcp_options_received *mp_opt) | |
600 | { | |
601 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
602 | ||
603 | subflow->remote_key = mp_opt->sndr_key; | |
604 | subflow->fully_established = 1; | |
605 | subflow->can_ack = 1; | |
606 | WRITE_ONCE(msk->fully_established, true); | |
607 | } | |
608 | ||
cec37a6e PK |
609 | static struct sock *subflow_syn_recv_sock(const struct sock *sk, |
610 | struct sk_buff *skb, | |
611 | struct request_sock *req, | |
612 | struct dst_entry *dst, | |
613 | struct request_sock *req_unhash, | |
614 | bool *own_req) | |
615 | { | |
616 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk); | |
cc7972ea | 617 | struct mptcp_subflow_request_sock *subflow_req; |
cfde141e | 618 | struct mptcp_options_received mp_opt; |
9e365ff5 | 619 | bool fallback, fallback_is_fatal; |
58b09919 | 620 | struct sock *new_msk = NULL; |
cec37a6e PK |
621 | struct sock *child; |
622 | ||
623 | pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); | |
624 | ||
9e365ff5 PA |
625 | /* After child creation we must look for 'mp_capable' even when options |
626 | * are not parsed | |
cfde141e PA |
627 | */ |
628 | mp_opt.mp_capable = 0; | |
9e365ff5 PA |
629 | |
630 | /* hopefully temporary handling for MP_JOIN+syncookie */ | |
631 | subflow_req = mptcp_subflow_rsk(req); | |
b7514694 | 632 | fallback_is_fatal = tcp_rsk(req)->is_mptcp && subflow_req->mp_join; |
9e365ff5 PA |
633 | fallback = !tcp_rsk(req)->is_mptcp; |
634 | if (fallback) | |
ae2dd716 FW |
635 | goto create_child; |
636 | ||
d22f4988 | 637 | /* if the sk is MP_CAPABLE, we try to fetch the client key */ |
cc7972ea | 638 | if (subflow_req->mp_capable) { |
06f9a435 PA |
639 | /* we can receive and accept an in-window, out-of-order pkt, |
640 | * which may not carry the MP_CAPABLE opt even on mptcp enabled | |
641 | * paths: always try to extract the peer key, and fallback | |
642 | * for packets missing it. | |
643 | * Even OoO DSS packets coming legitly after dropped or | |
644 | * reordered MPC will cause fallback, but we don't have other | |
645 | * options. | |
646 | */ | |
c863225b | 647 | mptcp_get_options(sk, skb, &mp_opt); |
cfde141e | 648 | if (!mp_opt.mp_capable) { |
4c8941de | 649 | fallback = true; |
58b09919 | 650 | goto create_child; |
d22f4988 | 651 | } |
58b09919 | 652 | |
cfde141e | 653 | new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); |
58b09919 | 654 | if (!new_msk) |
4c8941de | 655 | fallback = true; |
f296234c | 656 | } else if (subflow_req->mp_join) { |
c863225b | 657 | mptcp_get_options(sk, skb, &mp_opt); |
d3ab7885 PA |
658 | if (!mp_opt.mp_join || !subflow_hmac_valid(req, &mp_opt) || |
659 | !mptcp_can_accept_new_subflow(subflow_req->msk)) { | |
fc518953 | 660 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); |
9e365ff5 | 661 | fallback = true; |
fc518953 | 662 | } |
cc7972ea | 663 | } |
cec37a6e | 664 | |
d22f4988 | 665 | create_child: |
cec37a6e PK |
666 | child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, |
667 | req_unhash, own_req); | |
668 | ||
669 | if (child && *own_req) { | |
79c0949e PK |
670 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); |
671 | ||
90bf4513 PA |
672 | tcp_rsk(req)->drop_req = false; |
673 | ||
4c8941de PA |
674 | /* we need to fallback on ctx allocation failure and on pre-reqs |
675 | * checking above. In the latter scenario we additionally need | |
676 | * to reset the context to non MPTCP status. | |
79c0949e | 677 | */ |
4c8941de | 678 | if (!ctx || fallback) { |
dc87efdb FW |
679 | if (fallback_is_fatal) { |
680 | subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); | |
729cd643 | 681 | goto dispose_child; |
dc87efdb | 682 | } |
4c8941de | 683 | |
39884604 | 684 | subflow_drop_ctx(child); |
58b09919 | 685 | goto out; |
f296234c | 686 | } |
79c0949e | 687 | |
df00b087 FW |
688 | /* ssk inherits options of listener sk */ |
689 | ctx->setsockopt_seq = listener->setsockopt_seq; | |
690 | ||
79c0949e | 691 | if (ctx->mp_capable) { |
b93df08c PA |
692 | /* this can't race with mptcp_close(), as the msk is |
693 | * not yet exposted to user-space | |
694 | */ | |
695 | inet_sk_state_store((void *)new_msk, TCP_ESTABLISHED); | |
696 | ||
5b950ff4 PA |
697 | /* record the newly created socket as the first msk |
698 | * subflow, but don't link it yet into conn_list | |
699 | */ | |
0397c6d8 PA |
700 | WRITE_ONCE(mptcp_sk(new_msk)->first, child); |
701 | ||
58b09919 PA |
702 | /* new mpc subflow takes ownership of the newly |
703 | * created mptcp socket | |
704 | */ | |
df1036da | 705 | new_msk->sk_destruct = mptcp_sock_destruct; |
df00b087 | 706 | mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq; |
6c714f1b | 707 | mptcp_pm_new_connection(mptcp_sk(new_msk), child, 1); |
2c5ebd00 | 708 | mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); |
58b09919 PA |
709 | ctx->conn = new_msk; |
710 | new_msk = NULL; | |
fca5c82c PA |
711 | |
712 | /* with OoO packets we can reach here without ingress | |
713 | * mpc option | |
714 | */ | |
b93df08c PA |
715 | if (mp_opt.mp_capable) |
716 | mptcp_subflow_fully_established(ctx, &mp_opt); | |
f296234c PK |
717 | } else if (ctx->mp_join) { |
718 | struct mptcp_sock *owner; | |
719 | ||
8fd4de12 | 720 | owner = subflow_req->msk; |
dc87efdb FW |
721 | if (!owner) { |
722 | subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT); | |
729cd643 | 723 | goto dispose_child; |
dc87efdb | 724 | } |
f296234c | 725 | |
8fd4de12 PA |
726 | /* move the msk reference ownership to the subflow */ |
727 | subflow_req->msk = NULL; | |
f296234c | 728 | ctx->conn = (struct sock *)owner; |
5bc56388 GT |
729 | |
730 | if (subflow_use_different_sport(owner, sk)) { | |
731 | pr_debug("ack inet_sport=%d %d", | |
732 | ntohs(inet_sk(sk)->inet_sport), | |
733 | ntohs(inet_sk((struct sock *)owner)->inet_sport)); | |
2fbdd9ea GT |
734 | if (!mptcp_pm_sport_in_anno_list(owner, sk)) { |
735 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTACKRX); | |
9238e900 | 736 | goto dispose_child; |
2fbdd9ea GT |
737 | } |
738 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINPORTACKRX); | |
5bc56388 | 739 | } |
9238e900 GT |
740 | |
741 | if (!mptcp_finish_join(child)) | |
742 | goto dispose_child; | |
743 | ||
744 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); | |
745 | tcp_rsk(req)->drop_req = true; | |
cec37a6e PK |
746 | } |
747 | } | |
748 | ||
58b09919 PA |
749 | out: |
750 | /* dispose of the left over mptcp master, if any */ | |
751 | if (unlikely(new_msk)) | |
9f5ca6a5 | 752 | mptcp_force_close(new_msk); |
4c8941de PA |
753 | |
754 | /* check for expected invariant - should never trigger, just help | |
755 | * catching eariler subtle bugs | |
756 | */ | |
ac2b47fb | 757 | WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp && |
4c8941de PA |
758 | (!mptcp_subflow_ctx(child) || |
759 | !mptcp_subflow_ctx(child)->conn)); | |
cec37a6e | 760 | return child; |
f296234c | 761 | |
729cd643 | 762 | dispose_child: |
39884604 | 763 | subflow_drop_ctx(child); |
729cd643 | 764 | tcp_rsk(req)->drop_req = true; |
729cd643 | 765 | inet_csk_prepare_for_destroy_sock(child); |
f296234c | 766 | tcp_done(child); |
97e61751 | 767 | req->rsk_ops->send_reset(sk, skb); |
729cd643 PA |
768 | |
769 | /* The last child reference will be released by the caller */ | |
770 | return child; | |
cec37a6e PK |
771 | } |
772 | ||
773 | static struct inet_connection_sock_af_ops subflow_specific; | |
b19bc294 | 774 | static struct proto tcp_prot_override; |
cec37a6e | 775 | |
648ef4b8 MM |
776 | enum mapping_status { |
777 | MAPPING_OK, | |
778 | MAPPING_INVALID, | |
779 | MAPPING_EMPTY, | |
e1ff9e82 DC |
780 | MAPPING_DATA_FIN, |
781 | MAPPING_DUMMY | |
648ef4b8 MM |
782 | }; |
783 | ||
784 | static u64 expand_seq(u64 old_seq, u16 old_data_len, u64 seq) | |
785 | { | |
786 | if ((u32)seq == (u32)old_seq) | |
787 | return old_seq; | |
788 | ||
789 | /* Assume map covers data not mapped yet. */ | |
790 | return seq | ((old_seq + old_data_len + 1) & GENMASK_ULL(63, 32)); | |
791 | } | |
792 | ||
61e71022 | 793 | static void dbg_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) |
648ef4b8 | 794 | { |
61e71022 PA |
795 | pr_debug("Bad mapping: ssn=%d map_seq=%d map_data_len=%d", |
796 | ssn, subflow->map_subflow_seq, subflow->map_data_len); | |
648ef4b8 MM |
797 | } |
798 | ||
799 | static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) | |
800 | { | |
801 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
802 | unsigned int skb_consumed; | |
803 | ||
804 | skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; | |
805 | if (WARN_ON_ONCE(skb_consumed >= skb->len)) | |
806 | return true; | |
807 | ||
808 | return skb->len - skb_consumed <= subflow->map_data_len - | |
809 | mptcp_subflow_get_map_offset(subflow); | |
810 | } | |
811 | ||
812 | static bool validate_mapping(struct sock *ssk, struct sk_buff *skb) | |
813 | { | |
814 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
815 | u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
816 | ||
817 | if (unlikely(before(ssn, subflow->map_subflow_seq))) { | |
818 | /* Mapping covers data later in the subflow stream, | |
819 | * currently unsupported. | |
820 | */ | |
61e71022 | 821 | dbg_bad_map(subflow, ssn); |
648ef4b8 MM |
822 | return false; |
823 | } | |
824 | if (unlikely(!before(ssn, subflow->map_subflow_seq + | |
825 | subflow->map_data_len))) { | |
826 | /* Mapping does covers past subflow data, invalid */ | |
61e71022 | 827 | dbg_bad_map(subflow, ssn); |
648ef4b8 MM |
828 | return false; |
829 | } | |
830 | return true; | |
831 | } | |
832 | ||
dd8bcd17 PA |
833 | static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *skb, |
834 | bool csum_reqd) | |
835 | { | |
836 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
837 | struct csum_pseudo_header header; | |
838 | u32 offset, seq, delta; | |
839 | __wsum csum; | |
840 | int len; | |
841 | ||
842 | if (!csum_reqd) | |
843 | return MAPPING_OK; | |
844 | ||
845 | /* mapping already validated on previous traversal */ | |
846 | if (subflow->map_csum_len == subflow->map_data_len) | |
847 | return MAPPING_OK; | |
848 | ||
849 | /* traverse the receive queue, ensuring it contains a full | |
850 | * DSS mapping and accumulating the related csum. | |
851 | * Preserve the accoumlate csum across multiple calls, to compute | |
852 | * the csum only once | |
853 | */ | |
854 | delta = subflow->map_data_len - subflow->map_csum_len; | |
855 | for (;;) { | |
856 | seq = tcp_sk(ssk)->copied_seq + subflow->map_csum_len; | |
857 | offset = seq - TCP_SKB_CB(skb)->seq; | |
858 | ||
859 | /* if the current skb has not been accounted yet, csum its contents | |
860 | * up to the amount covered by the current DSS | |
861 | */ | |
862 | if (offset < skb->len) { | |
863 | __wsum csum; | |
864 | ||
865 | len = min(skb->len - offset, delta); | |
866 | csum = skb_checksum(skb, offset, len, 0); | |
867 | subflow->map_data_csum = csum_block_add(subflow->map_data_csum, csum, | |
868 | subflow->map_csum_len); | |
869 | ||
870 | delta -= len; | |
871 | subflow->map_csum_len += len; | |
872 | } | |
873 | if (delta == 0) | |
874 | break; | |
875 | ||
876 | if (skb_queue_is_last(&ssk->sk_receive_queue, skb)) { | |
877 | /* if this subflow is closed, the partial mapping | |
878 | * will be never completed; flush the pending skbs, so | |
879 | * that subflow_sched_work_if_closed() can kick in | |
880 | */ | |
881 | if (unlikely(ssk->sk_state == TCP_CLOSE)) | |
882 | while ((skb = skb_peek(&ssk->sk_receive_queue))) | |
883 | sk_eat_skb(ssk, skb); | |
884 | ||
885 | /* not enough data to validate the csum */ | |
886 | return MAPPING_EMPTY; | |
887 | } | |
888 | ||
889 | /* the DSS mapping for next skbs will be validated later, | |
890 | * when a get_mapping_status call will process such skb | |
891 | */ | |
892 | skb = skb->next; | |
893 | } | |
894 | ||
895 | /* note that 'map_data_len' accounts only for the carried data, does | |
896 | * not include the eventual seq increment due to the data fin, | |
897 | * while the pseudo header requires the original DSS data len, | |
898 | * including that | |
899 | */ | |
900 | header.data_seq = cpu_to_be64(subflow->map_seq); | |
901 | header.subflow_seq = htonl(subflow->map_subflow_seq); | |
902 | header.data_len = htons(subflow->map_data_len + subflow->map_data_fin); | |
903 | header.csum = 0; | |
904 | ||
905 | csum = csum_partial(&header, sizeof(header), subflow->map_data_csum); | |
fe3ab1cb GT |
906 | if (unlikely(csum_fold(csum))) { |
907 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR); | |
dd8bcd17 | 908 | return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY; |
fe3ab1cb | 909 | } |
dd8bcd17 PA |
910 | |
911 | return MAPPING_OK; | |
912 | } | |
913 | ||
43b54c6e MM |
914 | static enum mapping_status get_mapping_status(struct sock *ssk, |
915 | struct mptcp_sock *msk) | |
648ef4b8 MM |
916 | { |
917 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
dd8bcd17 | 918 | bool csum_reqd = READ_ONCE(msk->csum_enabled); |
648ef4b8 MM |
919 | struct mptcp_ext *mpext; |
920 | struct sk_buff *skb; | |
921 | u16 data_len; | |
922 | u64 map_seq; | |
923 | ||
924 | skb = skb_peek(&ssk->sk_receive_queue); | |
925 | if (!skb) | |
926 | return MAPPING_EMPTY; | |
927 | ||
e1ff9e82 DC |
928 | if (mptcp_check_fallback(ssk)) |
929 | return MAPPING_DUMMY; | |
930 | ||
648ef4b8 MM |
931 | mpext = mptcp_get_ext(skb); |
932 | if (!mpext || !mpext->use_map) { | |
933 | if (!subflow->map_valid && !skb->len) { | |
934 | /* the TCP stack deliver 0 len FIN pkt to the receive | |
935 | * queue, that is the only 0len pkts ever expected here, | |
936 | * and we can admit no mapping only for 0 len pkts | |
937 | */ | |
938 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) | |
939 | WARN_ONCE(1, "0len seq %d:%d flags %x", | |
940 | TCP_SKB_CB(skb)->seq, | |
941 | TCP_SKB_CB(skb)->end_seq, | |
942 | TCP_SKB_CB(skb)->tcp_flags); | |
943 | sk_eat_skb(ssk, skb); | |
944 | return MAPPING_EMPTY; | |
945 | } | |
946 | ||
947 | if (!subflow->map_valid) | |
948 | return MAPPING_INVALID; | |
949 | ||
950 | goto validate_seq; | |
951 | } | |
952 | ||
0918e34b | 953 | trace_get_mapping_status(mpext); |
648ef4b8 MM |
954 | |
955 | data_len = mpext->data_len; | |
956 | if (data_len == 0) { | |
fc518953 | 957 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); |
648ef4b8 MM |
958 | return MAPPING_INVALID; |
959 | } | |
960 | ||
961 | if (mpext->data_fin == 1) { | |
962 | if (data_len == 1) { | |
1a49b2c2 MM |
963 | bool updated = mptcp_update_rcv_data_fin(msk, mpext->data_seq, |
964 | mpext->dsn64); | |
43b54c6e | 965 | pr_debug("DATA_FIN with no payload seq=%llu", mpext->data_seq); |
648ef4b8 MM |
966 | if (subflow->map_valid) { |
967 | /* A DATA_FIN might arrive in a DSS | |
968 | * option before the previous mapping | |
969 | * has been fully consumed. Continue | |
970 | * handling the existing mapping. | |
971 | */ | |
972 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
973 | return MAPPING_OK; | |
974 | } else { | |
ef59b195 MM |
975 | if (updated && schedule_work(&msk->work)) |
976 | sock_hold((struct sock *)msk); | |
977 | ||
648ef4b8 MM |
978 | return MAPPING_DATA_FIN; |
979 | } | |
43b54c6e | 980 | } else { |
017512a0 | 981 | u64 data_fin_seq = mpext->data_seq + data_len - 1; |
1a49b2c2 MM |
982 | |
983 | /* If mpext->data_seq is a 32-bit value, data_fin_seq | |
984 | * must also be limited to 32 bits. | |
985 | */ | |
986 | if (!mpext->dsn64) | |
987 | data_fin_seq &= GENMASK_ULL(31, 0); | |
988 | ||
989 | mptcp_update_rcv_data_fin(msk, data_fin_seq, mpext->dsn64); | |
990 | pr_debug("DATA_FIN with mapping seq=%llu dsn64=%d", | |
991 | data_fin_seq, mpext->dsn64); | |
648ef4b8 MM |
992 | } |
993 | ||
994 | /* Adjust for DATA_FIN using 1 byte of sequence space */ | |
995 | data_len--; | |
996 | } | |
997 | ||
998 | if (!mpext->dsn64) { | |
999 | map_seq = expand_seq(subflow->map_seq, subflow->map_data_len, | |
1000 | mpext->data_seq); | |
1001 | pr_debug("expanded seq=%llu", subflow->map_seq); | |
1002 | } else { | |
1003 | map_seq = mpext->data_seq; | |
1004 | } | |
37198e93 | 1005 | WRITE_ONCE(mptcp_sk(subflow->conn)->use_64bit_ack, !!mpext->dsn64); |
648ef4b8 MM |
1006 | |
1007 | if (subflow->map_valid) { | |
1008 | /* Allow replacing only with an identical map */ | |
1009 | if (subflow->map_seq == map_seq && | |
1010 | subflow->map_subflow_seq == mpext->subflow_seq && | |
dd8bcd17 PA |
1011 | subflow->map_data_len == data_len && |
1012 | subflow->map_csum_reqd == mpext->csum_reqd) { | |
648ef4b8 | 1013 | skb_ext_del(skb, SKB_EXT_MPTCP); |
dd8bcd17 | 1014 | goto validate_csum; |
648ef4b8 MM |
1015 | } |
1016 | ||
1017 | /* If this skb data are fully covered by the current mapping, | |
1018 | * the new map would need caching, which is not supported | |
1019 | */ | |
fc518953 FW |
1020 | if (skb_is_fully_mapped(ssk, skb)) { |
1021 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH); | |
648ef4b8 | 1022 | return MAPPING_INVALID; |
fc518953 | 1023 | } |
648ef4b8 MM |
1024 | |
1025 | /* will validate the next map after consuming the current one */ | |
dd8bcd17 | 1026 | goto validate_csum; |
648ef4b8 MM |
1027 | } |
1028 | ||
1029 | subflow->map_seq = map_seq; | |
1030 | subflow->map_subflow_seq = mpext->subflow_seq; | |
1031 | subflow->map_data_len = data_len; | |
1032 | subflow->map_valid = 1; | |
dd8bcd17 | 1033 | subflow->map_data_fin = mpext->data_fin; |
d22f4988 | 1034 | subflow->mpc_map = mpext->mpc_map; |
dd8bcd17 PA |
1035 | subflow->map_csum_reqd = mpext->csum_reqd; |
1036 | subflow->map_csum_len = 0; | |
1037 | subflow->map_data_csum = csum_unfold(mpext->csum); | |
1038 | ||
1039 | /* Cfr RFC 8684 Section 3.3.0 */ | |
1040 | if (unlikely(subflow->map_csum_reqd != csum_reqd)) | |
1041 | return MAPPING_INVALID; | |
1042 | ||
1043 | pr_debug("new map seq=%llu subflow_seq=%u data_len=%u csum=%d:%u", | |
648ef4b8 | 1044 | subflow->map_seq, subflow->map_subflow_seq, |
dd8bcd17 PA |
1045 | subflow->map_data_len, subflow->map_csum_reqd, |
1046 | subflow->map_data_csum); | |
648ef4b8 MM |
1047 | |
1048 | validate_seq: | |
1049 | /* we revalidate valid mapping on new skb, because we must ensure | |
1050 | * the current skb is completely covered by the available mapping | |
1051 | */ | |
06285da9 PA |
1052 | if (!validate_mapping(ssk, skb)) { |
1053 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSTCPMISMATCH); | |
648ef4b8 | 1054 | return MAPPING_INVALID; |
06285da9 | 1055 | } |
648ef4b8 MM |
1056 | |
1057 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
dd8bcd17 PA |
1058 | |
1059 | validate_csum: | |
1060 | return validate_data_csum(ssk, skb, csum_reqd); | |
648ef4b8 MM |
1061 | } |
1062 | ||
04e4cd4f | 1063 | static void mptcp_subflow_discard_data(struct sock *ssk, struct sk_buff *skb, |
1d39cd8c | 1064 | u64 limit) |
6719331c PA |
1065 | { |
1066 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
04e4cd4f PA |
1067 | bool fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; |
1068 | u32 incr; | |
1069 | ||
1070 | incr = limit >= skb->len ? skb->len + fin : limit; | |
1071 | ||
1072 | pr_debug("discarding=%d len=%d seq=%d", incr, skb->len, | |
1073 | subflow->map_subflow_seq); | |
06242e44 | 1074 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DUPDATA); |
04e4cd4f PA |
1075 | tcp_sk(ssk)->copied_seq += incr; |
1076 | if (!before(tcp_sk(ssk)->copied_seq, TCP_SKB_CB(skb)->end_seq)) | |
1077 | sk_eat_skb(ssk, skb); | |
1078 | if (mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) | |
1079 | subflow->map_valid = 0; | |
6719331c PA |
1080 | } |
1081 | ||
40947e13 FW |
1082 | /* sched mptcp worker to remove the subflow if no more data is pending */ |
1083 | static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ssk) | |
1084 | { | |
1085 | struct sock *sk = (struct sock *)msk; | |
1086 | ||
1087 | if (likely(ssk->sk_state != TCP_CLOSE)) | |
1088 | return; | |
1089 | ||
1090 | if (skb_queue_empty(&ssk->sk_receive_queue) && | |
1091 | !test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) { | |
1092 | sock_hold(sk); | |
1093 | if (!schedule_work(&msk->work)) | |
1094 | sock_put(sk); | |
1095 | } | |
1096 | } | |
1097 | ||
648ef4b8 MM |
1098 | static bool subflow_check_data_avail(struct sock *ssk) |
1099 | { | |
1100 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1101 | enum mapping_status status; | |
1102 | struct mptcp_sock *msk; | |
1103 | struct sk_buff *skb; | |
1104 | ||
47bebdf3 | 1105 | if (!skb_peek(&ssk->sk_receive_queue)) |
99d1055c | 1106 | WRITE_ONCE(subflow->data_avail, 0); |
648ef4b8 MM |
1107 | if (subflow->data_avail) |
1108 | return true; | |
1109 | ||
648ef4b8 MM |
1110 | msk = mptcp_sk(subflow->conn); |
1111 | for (;;) { | |
648ef4b8 MM |
1112 | u64 ack_seq; |
1113 | u64 old_ack; | |
1114 | ||
43b54c6e | 1115 | status = get_mapping_status(ssk, msk); |
d96a838a | 1116 | trace_subflow_check_data_avail(status, skb_peek(&ssk->sk_receive_queue)); |
dea2b1ea PA |
1117 | if (unlikely(status == MAPPING_INVALID)) |
1118 | goto fallback; | |
1119 | ||
1120 | if (unlikely(status == MAPPING_DUMMY)) | |
1121 | goto fallback; | |
648ef4b8 MM |
1122 | |
1123 | if (status != MAPPING_OK) | |
40947e13 | 1124 | goto no_data; |
648ef4b8 MM |
1125 | |
1126 | skb = skb_peek(&ssk->sk_receive_queue); | |
1127 | if (WARN_ON_ONCE(!skb)) | |
40947e13 | 1128 | goto no_data; |
648ef4b8 | 1129 | |
d22f4988 CP |
1130 | /* if msk lacks the remote key, this subflow must provide an |
1131 | * MP_CAPABLE-based mapping | |
1132 | */ | |
1133 | if (unlikely(!READ_ONCE(msk->can_ack))) { | |
dea2b1ea PA |
1134 | if (!subflow->mpc_map) |
1135 | goto fallback; | |
d22f4988 CP |
1136 | WRITE_ONCE(msk->remote_key, subflow->remote_key); |
1137 | WRITE_ONCE(msk->ack_seq, subflow->map_seq); | |
1138 | WRITE_ONCE(msk->can_ack, true); | |
1139 | } | |
1140 | ||
648ef4b8 MM |
1141 | old_ack = READ_ONCE(msk->ack_seq); |
1142 | ack_seq = mptcp_subflow_get_mapped_dsn(subflow); | |
1143 | pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, | |
1144 | ack_seq); | |
99d1055c PA |
1145 | if (unlikely(before64(ack_seq, old_ack))) { |
1146 | mptcp_subflow_discard_data(ssk, skb, old_ack - ack_seq); | |
1147 | continue; | |
47bebdf3 | 1148 | } |
648ef4b8 | 1149 | |
99d1055c PA |
1150 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); |
1151 | break; | |
648ef4b8 MM |
1152 | } |
1153 | return true; | |
1154 | ||
40947e13 FW |
1155 | no_data: |
1156 | subflow_sched_work_if_closed(msk, ssk); | |
1157 | return false; | |
dea2b1ea PA |
1158 | |
1159 | fallback: | |
1160 | /* RFC 8684 section 3.7. */ | |
1161 | if (subflow->mp_join || subflow->fully_established) { | |
1162 | /* fatal protocol error, close the socket. | |
1163 | * subflow_error_report() will introduce the appropriate barriers | |
1164 | */ | |
1165 | ssk->sk_err = EBADMSG; | |
dea2b1ea PA |
1166 | tcp_set_state(ssk, TCP_CLOSE); |
1167 | subflow->reset_transient = 0; | |
1168 | subflow->reset_reason = MPTCP_RST_EMPTCP; | |
1169 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
99d1055c | 1170 | WRITE_ONCE(subflow->data_avail, 0); |
dea2b1ea PA |
1171 | return false; |
1172 | } | |
1173 | ||
1174 | __mptcp_do_fallback(msk); | |
1175 | skb = skb_peek(&ssk->sk_receive_queue); | |
1176 | subflow->map_valid = 1; | |
1177 | subflow->map_seq = READ_ONCE(msk->ack_seq); | |
1178 | subflow->map_data_len = skb->len; | |
1179 | subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
99d1055c | 1180 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); |
dea2b1ea | 1181 | return true; |
648ef4b8 MM |
1182 | } |
1183 | ||
1184 | bool mptcp_subflow_data_available(struct sock *sk) | |
1185 | { | |
1186 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
648ef4b8 MM |
1187 | |
1188 | /* check if current mapping is still valid */ | |
1189 | if (subflow->map_valid && | |
1190 | mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) { | |
1191 | subflow->map_valid = 0; | |
99d1055c | 1192 | WRITE_ONCE(subflow->data_avail, 0); |
648ef4b8 MM |
1193 | |
1194 | pr_debug("Done with mapping: seq=%u data_len=%u", | |
1195 | subflow->map_subflow_seq, | |
1196 | subflow->map_data_len); | |
1197 | } | |
1198 | ||
47bebdf3 | 1199 | return subflow_check_data_avail(sk); |
648ef4b8 MM |
1200 | } |
1201 | ||
071c8ed6 FW |
1202 | /* If ssk has an mptcp parent socket, use the mptcp rcvbuf occupancy, |
1203 | * not the ssk one. | |
1204 | * | |
1205 | * In mptcp, rwin is about the mptcp-level connection data. | |
1206 | * | |
1207 | * Data that is still on the ssk rx queue can thus be ignored, | |
55320b82 | 1208 | * as far as mptcp peer is concerned that data is still inflight. |
071c8ed6 FW |
1209 | * DSS ACK is updated when skb is moved to the mptcp rx queue. |
1210 | */ | |
1211 | void mptcp_space(const struct sock *ssk, int *space, int *full_space) | |
1212 | { | |
1213 | const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1214 | const struct sock *sk = subflow->conn; | |
1215 | ||
ea4ca586 | 1216 | *space = __mptcp_space(sk); |
071c8ed6 FW |
1217 | *full_space = tcp_full_space(sk); |
1218 | } | |
1219 | ||
15cc1045 PA |
1220 | void __mptcp_error_report(struct sock *sk) |
1221 | { | |
1222 | struct mptcp_subflow_context *subflow; | |
1223 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1224 | ||
1225 | mptcp_for_each_subflow(msk, subflow) { | |
1226 | struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | |
1227 | int err = sock_error(ssk); | |
1228 | ||
1229 | if (!err) | |
1230 | continue; | |
1231 | ||
1232 | /* only propagate errors on fallen-back sockets or | |
1233 | * on MPC connect | |
1234 | */ | |
1235 | if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(msk)) | |
1236 | continue; | |
1237 | ||
1238 | inet_sk_state_store(sk, inet_sk_state_load(ssk)); | |
1239 | sk->sk_err = -err; | |
1240 | ||
1241 | /* This barrier is coupled with smp_rmb() in mptcp_poll() */ | |
1242 | smp_wmb(); | |
1243 | sk->sk_error_report(sk); | |
1244 | break; | |
1245 | } | |
1246 | } | |
1247 | ||
1248 | static void subflow_error_report(struct sock *ssk) | |
1249 | { | |
1250 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1251 | ||
1252 | mptcp_data_lock(sk); | |
1253 | if (!sock_owned_by_user(sk)) | |
1254 | __mptcp_error_report(sk); | |
1255 | else | |
1256 | set_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags); | |
1257 | mptcp_data_unlock(sk); | |
1258 | } | |
1259 | ||
499ada50 PA |
1260 | static void subflow_data_ready(struct sock *sk) |
1261 | { | |
1262 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
1263 | u16 state = 1 << inet_sk_state_load(sk); | |
1264 | struct sock *parent = subflow->conn; | |
1265 | struct mptcp_sock *msk; | |
1266 | ||
1267 | msk = mptcp_sk(parent); | |
1268 | if (state & TCPF_LISTEN) { | |
1269 | /* MPJ subflow are removed from accept queue before reaching here, | |
1270 | * avoid stray wakeups | |
1271 | */ | |
1272 | if (reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue)) | |
1273 | return; | |
1274 | ||
1275 | set_bit(MPTCP_DATA_READY, &msk->flags); | |
1276 | parent->sk_data_ready(parent); | |
1277 | return; | |
1278 | } | |
1279 | ||
1280 | WARN_ON_ONCE(!__mptcp_check_fallback(msk) && !subflow->mp_capable && | |
1281 | !subflow->mp_join && !(state & TCPF_CLOSE)); | |
1282 | ||
1283 | if (mptcp_subflow_data_available(sk)) | |
1284 | mptcp_data_ready(parent, sk); | |
1285 | else if (unlikely(sk->sk_err)) | |
1286 | subflow_error_report(sk); | |
1287 | } | |
1288 | ||
1289 | static void subflow_write_space(struct sock *ssk) | |
1290 | { | |
1291 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1292 | ||
1293 | mptcp_propagate_sndbuf(sk, ssk); | |
1294 | mptcp_write_space(sk); | |
1295 | } | |
1296 | ||
cec37a6e PK |
1297 | static struct inet_connection_sock_af_ops * |
1298 | subflow_default_af_ops(struct sock *sk) | |
1299 | { | |
1300 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1301 | if (sk->sk_family == AF_INET6) | |
1302 | return &subflow_v6_specific; | |
1303 | #endif | |
1304 | return &subflow_specific; | |
1305 | } | |
1306 | ||
cec37a6e | 1307 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
31484d56 GU |
1308 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped) |
1309 | { | |
cec37a6e PK |
1310 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1311 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1312 | struct inet_connection_sock_af_ops *target; | |
1313 | ||
1314 | target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk); | |
1315 | ||
1316 | pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d", | |
edc7e489 | 1317 | subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped); |
cec37a6e PK |
1318 | |
1319 | if (likely(icsk->icsk_af_ops == target)) | |
1320 | return; | |
1321 | ||
1322 | subflow->icsk_af_ops = icsk->icsk_af_ops; | |
1323 | icsk->icsk_af_ops = target; | |
cec37a6e | 1324 | } |
31484d56 | 1325 | #endif |
cec37a6e | 1326 | |
1729cf18 GT |
1327 | void mptcp_info2sockaddr(const struct mptcp_addr_info *info, |
1328 | struct sockaddr_storage *addr, | |
1329 | unsigned short family) | |
ec3edaa7 PK |
1330 | { |
1331 | memset(addr, 0, sizeof(*addr)); | |
50a13bc3 | 1332 | addr->ss_family = family; |
ec3edaa7 PK |
1333 | if (addr->ss_family == AF_INET) { |
1334 | struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; | |
1335 | ||
50a13bc3 MB |
1336 | if (info->family == AF_INET) |
1337 | in_addr->sin_addr = info->addr; | |
1338 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1339 | else if (ipv6_addr_v4mapped(&info->addr6)) | |
1340 | in_addr->sin_addr.s_addr = info->addr6.s6_addr32[3]; | |
1341 | #endif | |
ec3edaa7 PK |
1342 | in_addr->sin_port = info->port; |
1343 | } | |
1344 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1345 | else if (addr->ss_family == AF_INET6) { | |
1346 | struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; | |
1347 | ||
50a13bc3 MB |
1348 | if (info->family == AF_INET) |
1349 | ipv6_addr_set_v4mapped(info->addr.s_addr, | |
1350 | &in6_addr->sin6_addr); | |
1351 | else | |
1352 | in6_addr->sin6_addr = info->addr6; | |
ec3edaa7 PK |
1353 | in6_addr->sin6_port = info->port; |
1354 | } | |
1355 | #endif | |
1356 | } | |
1357 | ||
ef0da3b8 | 1358 | int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, |
daa83ab0 GT |
1359 | const struct mptcp_addr_info *remote, |
1360 | u8 flags, int ifindex) | |
ec3edaa7 PK |
1361 | { |
1362 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1363 | struct mptcp_subflow_context *subflow; | |
1364 | struct sockaddr_storage addr; | |
2ff0e566 | 1365 | int remote_id = remote->id; |
6bad912b | 1366 | int local_id = loc->id; |
ec3edaa7 | 1367 | struct socket *sf; |
6bad912b | 1368 | struct sock *ssk; |
ec3edaa7 PK |
1369 | u32 remote_token; |
1370 | int addrlen; | |
1371 | int err; | |
1372 | ||
b93df08c | 1373 | if (!mptcp_is_fully_established(sk)) |
ec3edaa7 PK |
1374 | return -ENOTCONN; |
1375 | ||
1376 | err = mptcp_subflow_create_socket(sk, &sf); | |
1377 | if (err) | |
1378 | return err; | |
1379 | ||
6bad912b PA |
1380 | ssk = sf->sk; |
1381 | subflow = mptcp_subflow_ctx(ssk); | |
1382 | do { | |
1383 | get_random_bytes(&subflow->local_nonce, sizeof(u32)); | |
1384 | } while (!subflow->local_nonce); | |
1385 | ||
1386 | if (!local_id) { | |
1387 | err = mptcp_pm_get_local_id(msk, (struct sock_common *)ssk); | |
1388 | if (err < 0) | |
1389 | goto failed; | |
1390 | ||
1391 | local_id = err; | |
1392 | } | |
1393 | ||
ec3edaa7 PK |
1394 | subflow->remote_key = msk->remote_key; |
1395 | subflow->local_key = msk->local_key; | |
1396 | subflow->token = msk->token; | |
50a13bc3 | 1397 | mptcp_info2sockaddr(loc, &addr, ssk->sk_family); |
ec3edaa7 PK |
1398 | |
1399 | addrlen = sizeof(struct sockaddr_in); | |
1400 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
50a13bc3 | 1401 | if (addr.ss_family == AF_INET6) |
ec3edaa7 PK |
1402 | addrlen = sizeof(struct sockaddr_in6); |
1403 | #endif | |
daa83ab0 | 1404 | ssk->sk_bound_dev_if = ifindex; |
ec3edaa7 PK |
1405 | err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); |
1406 | if (err) | |
1407 | goto failed; | |
1408 | ||
1409 | mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); | |
2ff0e566 GT |
1410 | pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk, |
1411 | remote_token, local_id, remote_id); | |
ec3edaa7 | 1412 | subflow->remote_token = remote_token; |
6bad912b | 1413 | subflow->local_id = local_id; |
2ff0e566 | 1414 | subflow->remote_id = remote_id; |
ec3edaa7 | 1415 | subflow->request_join = 1; |
daa83ab0 | 1416 | subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP); |
50a13bc3 | 1417 | mptcp_info2sockaddr(remote, &addr, ssk->sk_family); |
ec3edaa7 | 1418 | |
5b950ff4 | 1419 | mptcp_add_pending_subflow(msk, subflow); |
78962489 | 1420 | mptcp_sockopt_sync(msk, ssk); |
ec3edaa7 PK |
1421 | err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); |
1422 | if (err && err != -EINPROGRESS) | |
5b950ff4 | 1423 | goto failed_unlink; |
ec3edaa7 | 1424 | |
866f26f2 PA |
1425 | /* discard the subflow socket */ |
1426 | mptcp_sock_graft(ssk, sk->sk_socket); | |
1427 | iput(SOCK_INODE(sf)); | |
ec3edaa7 PK |
1428 | return err; |
1429 | ||
5b950ff4 | 1430 | failed_unlink: |
ec3edaa7 | 1431 | spin_lock_bh(&msk->join_list_lock); |
5b950ff4 | 1432 | list_del(&subflow->node); |
ec3edaa7 | 1433 | spin_unlock_bh(&msk->join_list_lock); |
f0715779 | 1434 | sock_put(mptcp_subflow_tcp_sock(subflow)); |
ec3edaa7 | 1435 | |
ec3edaa7 | 1436 | failed: |
e16163b6 | 1437 | subflow->disposable = 1; |
ec3edaa7 PK |
1438 | sock_release(sf); |
1439 | return err; | |
1440 | } | |
1441 | ||
3764b0c5 NR |
1442 | static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) |
1443 | { | |
1444 | #ifdef CONFIG_SOCK_CGROUP_DATA | |
1445 | struct sock_cgroup_data *parent_skcd = &parent->sk_cgrp_data, | |
1446 | *child_skcd = &child->sk_cgrp_data; | |
1447 | ||
1448 | /* only the additional subflows created by kworkers have to be modified */ | |
1449 | if (cgroup_id(sock_cgroup_ptr(parent_skcd)) != | |
1450 | cgroup_id(sock_cgroup_ptr(child_skcd))) { | |
1451 | #ifdef CONFIG_MEMCG | |
1452 | struct mem_cgroup *memcg = parent->sk_memcg; | |
1453 | ||
1454 | mem_cgroup_sk_free(child); | |
1455 | if (memcg && css_tryget(&memcg->css)) | |
1456 | child->sk_memcg = memcg; | |
1457 | #endif /* CONFIG_MEMCG */ | |
1458 | ||
1459 | cgroup_sk_free(child_skcd); | |
1460 | *child_skcd = *parent_skcd; | |
1461 | cgroup_sk_clone(child_skcd); | |
1462 | } | |
1463 | #endif /* CONFIG_SOCK_CGROUP_DATA */ | |
1464 | } | |
1465 | ||
b19bc294 PA |
1466 | static void mptcp_subflow_ops_override(struct sock *ssk) |
1467 | { | |
1468 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1469 | if (ssk->sk_prot == &tcpv6_prot) | |
1470 | ssk->sk_prot = &tcpv6_prot_override; | |
1471 | else | |
1472 | #endif | |
1473 | ssk->sk_prot = &tcp_prot_override; | |
1474 | } | |
1475 | ||
1476 | static void mptcp_subflow_ops_undo_override(struct sock *ssk) | |
1477 | { | |
1478 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1479 | if (ssk->sk_prot == &tcpv6_prot_override) | |
1480 | ssk->sk_prot = &tcpv6_prot; | |
1481 | else | |
1482 | #endif | |
1483 | ssk->sk_prot = &tcp_prot; | |
1484 | } | |
2303f994 PK |
1485 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) |
1486 | { | |
1487 | struct mptcp_subflow_context *subflow; | |
1488 | struct net *net = sock_net(sk); | |
1489 | struct socket *sf; | |
1490 | int err; | |
1491 | ||
adf73410 PA |
1492 | /* un-accepted server sockets can reach here - on bad configuration |
1493 | * bail early to avoid greater trouble later | |
1494 | */ | |
1495 | if (unlikely(!sk->sk_socket)) | |
1496 | return -EINVAL; | |
1497 | ||
cec37a6e PK |
1498 | err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP, |
1499 | &sf); | |
2303f994 PK |
1500 | if (err) |
1501 | return err; | |
1502 | ||
1503 | lock_sock(sf->sk); | |
1504 | ||
3764b0c5 NR |
1505 | /* the newly created socket has to be in the same cgroup as its parent */ |
1506 | mptcp_attach_cgroup(sk, sf->sk); | |
1507 | ||
2303f994 PK |
1508 | /* kernel sockets do not by default acquire net ref, but TCP timer |
1509 | * needs it. | |
1510 | */ | |
1511 | sf->sk->sk_net_refcnt = 1; | |
1512 | get_net(net); | |
f6f7d8cf | 1513 | #ifdef CONFIG_PROC_FS |
2303f994 | 1514 | this_cpu_add(*net->core.sock_inuse, 1); |
f6f7d8cf | 1515 | #endif |
2303f994 PK |
1516 | err = tcp_set_ulp(sf->sk, "mptcp"); |
1517 | release_sock(sf->sk); | |
1518 | ||
b8ad540d WY |
1519 | if (err) { |
1520 | sock_release(sf); | |
2303f994 | 1521 | return err; |
b8ad540d | 1522 | } |
2303f994 | 1523 | |
7d14b0d2 PA |
1524 | /* the newly created socket really belongs to the owning MPTCP master |
1525 | * socket, even if for additional subflows the allocation is performed | |
1526 | * by a kernel workqueue. Adjust inode references, so that the | |
1527 | * procfs/diag interaces really show this one belonging to the correct | |
1528 | * user. | |
1529 | */ | |
1530 | SOCK_INODE(sf)->i_ino = SOCK_INODE(sk->sk_socket)->i_ino; | |
1531 | SOCK_INODE(sf)->i_uid = SOCK_INODE(sk->sk_socket)->i_uid; | |
1532 | SOCK_INODE(sf)->i_gid = SOCK_INODE(sk->sk_socket)->i_gid; | |
1533 | ||
2303f994 PK |
1534 | subflow = mptcp_subflow_ctx(sf->sk); |
1535 | pr_debug("subflow=%p", subflow); | |
1536 | ||
1537 | *new_sock = sf; | |
79c0949e | 1538 | sock_hold(sk); |
2303f994 | 1539 | subflow->conn = sk; |
b19bc294 | 1540 | mptcp_subflow_ops_override(sf->sk); |
2303f994 PK |
1541 | |
1542 | return 0; | |
1543 | } | |
1544 | ||
1545 | static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, | |
1546 | gfp_t priority) | |
1547 | { | |
1548 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1549 | struct mptcp_subflow_context *ctx; | |
1550 | ||
1551 | ctx = kzalloc(sizeof(*ctx), priority); | |
1552 | if (!ctx) | |
1553 | return NULL; | |
1554 | ||
1555 | rcu_assign_pointer(icsk->icsk_ulp_data, ctx); | |
cec37a6e | 1556 | INIT_LIST_HEAD(&ctx->node); |
b19bc294 | 1557 | INIT_LIST_HEAD(&ctx->delegated_node); |
2303f994 PK |
1558 | |
1559 | pr_debug("subflow=%p", ctx); | |
1560 | ||
1561 | ctx->tcp_sock = sk; | |
1562 | ||
1563 | return ctx; | |
1564 | } | |
1565 | ||
648ef4b8 MM |
1566 | static void __subflow_state_change(struct sock *sk) |
1567 | { | |
1568 | struct socket_wq *wq; | |
1569 | ||
1570 | rcu_read_lock(); | |
1571 | wq = rcu_dereference(sk->sk_wq); | |
1572 | if (skwq_has_sleeper(wq)) | |
1573 | wake_up_interruptible_all(&wq->wait); | |
1574 | rcu_read_unlock(); | |
1575 | } | |
1576 | ||
1577 | static bool subflow_is_done(const struct sock *sk) | |
1578 | { | |
1579 | return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE; | |
1580 | } | |
1581 | ||
1582 | static void subflow_state_change(struct sock *sk) | |
1583 | { | |
1584 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
dc093db5 | 1585 | struct sock *parent = subflow->conn; |
648ef4b8 MM |
1586 | |
1587 | __subflow_state_change(sk); | |
1588 | ||
8fd73804 | 1589 | if (subflow_simultaneous_connect(sk)) { |
5cf92bba | 1590 | mptcp_propagate_sndbuf(parent, sk); |
8fd73804 | 1591 | mptcp_do_fallback(sk); |
a6b118fe | 1592 | mptcp_rcv_space_init(mptcp_sk(parent), sk); |
8fd73804 DC |
1593 | pr_fallback(mptcp_sk(parent)); |
1594 | subflow->conn_finished = 1; | |
1595 | if (inet_sk_state_load(parent) == TCP_SYN_SENT) { | |
1596 | inet_sk_state_store(parent, TCP_ESTABLISHED); | |
1597 | parent->sk_state_change(parent); | |
1598 | } | |
1599 | } | |
1600 | ||
648ef4b8 MM |
1601 | /* as recvmsg() does not acquire the subflow socket for ssk selection |
1602 | * a fin packet carrying a DSS can be unnoticed if we don't trigger | |
1603 | * the data available machinery here. | |
1604 | */ | |
e1ff9e82 | 1605 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 1606 | mptcp_data_ready(parent, sk); |
499ada50 PA |
1607 | else if (unlikely(sk->sk_err)) |
1608 | subflow_error_report(sk); | |
648ef4b8 | 1609 | |
40947e13 FW |
1610 | subflow_sched_work_if_closed(mptcp_sk(parent), sk); |
1611 | ||
067a0b3d | 1612 | if (__mptcp_check_fallback(mptcp_sk(parent)) && |
648ef4b8 MM |
1613 | !subflow->rx_eof && subflow_is_done(sk)) { |
1614 | subflow->rx_eof = 1; | |
59832e24 | 1615 | mptcp_subflow_eof(parent); |
648ef4b8 MM |
1616 | } |
1617 | } | |
1618 | ||
2303f994 PK |
1619 | static int subflow_ulp_init(struct sock *sk) |
1620 | { | |
cec37a6e | 1621 | struct inet_connection_sock *icsk = inet_csk(sk); |
2303f994 PK |
1622 | struct mptcp_subflow_context *ctx; |
1623 | struct tcp_sock *tp = tcp_sk(sk); | |
1624 | int err = 0; | |
1625 | ||
1626 | /* disallow attaching ULP to a socket unless it has been | |
1627 | * created with sock_create_kern() | |
1628 | */ | |
1629 | if (!sk->sk_kern_sock) { | |
1630 | err = -EOPNOTSUPP; | |
1631 | goto out; | |
1632 | } | |
1633 | ||
1634 | ctx = subflow_create_ctx(sk, GFP_KERNEL); | |
1635 | if (!ctx) { | |
1636 | err = -ENOMEM; | |
1637 | goto out; | |
1638 | } | |
1639 | ||
1640 | pr_debug("subflow=%p, family=%d", ctx, sk->sk_family); | |
1641 | ||
1642 | tp->is_mptcp = 1; | |
cec37a6e PK |
1643 | ctx->icsk_af_ops = icsk->icsk_af_ops; |
1644 | icsk->icsk_af_ops = subflow_default_af_ops(sk); | |
648ef4b8 MM |
1645 | ctx->tcp_data_ready = sk->sk_data_ready; |
1646 | ctx->tcp_state_change = sk->sk_state_change; | |
1647 | ctx->tcp_write_space = sk->sk_write_space; | |
15cc1045 | 1648 | ctx->tcp_error_report = sk->sk_error_report; |
648ef4b8 MM |
1649 | sk->sk_data_ready = subflow_data_ready; |
1650 | sk->sk_write_space = subflow_write_space; | |
1651 | sk->sk_state_change = subflow_state_change; | |
15cc1045 | 1652 | sk->sk_error_report = subflow_error_report; |
2303f994 PK |
1653 | out: |
1654 | return err; | |
1655 | } | |
1656 | ||
e16163b6 | 1657 | static void subflow_ulp_release(struct sock *ssk) |
2303f994 | 1658 | { |
e16163b6 PA |
1659 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); |
1660 | bool release = true; | |
1661 | struct sock *sk; | |
2303f994 PK |
1662 | |
1663 | if (!ctx) | |
1664 | return; | |
1665 | ||
e16163b6 PA |
1666 | sk = ctx->conn; |
1667 | if (sk) { | |
1668 | /* if the msk has been orphaned, keep the ctx | |
0597d0f8 PA |
1669 | * alive, will be freed by __mptcp_close_ssk(), |
1670 | * when the subflow is still unaccepted | |
e16163b6 | 1671 | */ |
0597d0f8 | 1672 | release = ctx->disposable || list_empty(&ctx->node); |
e16163b6 PA |
1673 | sock_put(sk); |
1674 | } | |
79c0949e | 1675 | |
b19bc294 | 1676 | mptcp_subflow_ops_undo_override(ssk); |
e16163b6 PA |
1677 | if (release) |
1678 | kfree_rcu(ctx, rcu); | |
2303f994 PK |
1679 | } |
1680 | ||
cec37a6e PK |
1681 | static void subflow_ulp_clone(const struct request_sock *req, |
1682 | struct sock *newsk, | |
1683 | const gfp_t priority) | |
1684 | { | |
1685 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
1686 | struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk); | |
1687 | struct mptcp_subflow_context *new_ctx; | |
1688 | ||
f296234c PK |
1689 | if (!tcp_rsk(req)->is_mptcp || |
1690 | (!subflow_req->mp_capable && !subflow_req->mp_join)) { | |
648ef4b8 | 1691 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1692 | return; |
1693 | } | |
1694 | ||
1695 | new_ctx = subflow_create_ctx(newsk, priority); | |
edc7e489 | 1696 | if (!new_ctx) { |
648ef4b8 | 1697 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1698 | return; |
1699 | } | |
1700 | ||
1701 | new_ctx->conn_finished = 1; | |
1702 | new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; | |
648ef4b8 MM |
1703 | new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; |
1704 | new_ctx->tcp_state_change = old_ctx->tcp_state_change; | |
1705 | new_ctx->tcp_write_space = old_ctx->tcp_write_space; | |
15cc1045 | 1706 | new_ctx->tcp_error_report = old_ctx->tcp_error_report; |
58b09919 PA |
1707 | new_ctx->rel_write_seq = 1; |
1708 | new_ctx->tcp_sock = newsk; | |
1709 | ||
f296234c PK |
1710 | if (subflow_req->mp_capable) { |
1711 | /* see comments in subflow_syn_recv_sock(), MPTCP connection | |
1712 | * is fully established only after we receive the remote key | |
1713 | */ | |
1714 | new_ctx->mp_capable = 1; | |
f296234c PK |
1715 | new_ctx->local_key = subflow_req->local_key; |
1716 | new_ctx->token = subflow_req->token; | |
1717 | new_ctx->ssn_offset = subflow_req->ssn_offset; | |
1718 | new_ctx->idsn = subflow_req->idsn; | |
1719 | } else if (subflow_req->mp_join) { | |
ec3edaa7 | 1720 | new_ctx->ssn_offset = subflow_req->ssn_offset; |
f296234c PK |
1721 | new_ctx->mp_join = 1; |
1722 | new_ctx->fully_established = 1; | |
1723 | new_ctx->backup = subflow_req->backup; | |
1724 | new_ctx->local_id = subflow_req->local_id; | |
2ff0e566 | 1725 | new_ctx->remote_id = subflow_req->remote_id; |
f296234c PK |
1726 | new_ctx->token = subflow_req->token; |
1727 | new_ctx->thmac = subflow_req->thmac; | |
1728 | } | |
cec37a6e PK |
1729 | } |
1730 | ||
b19bc294 PA |
1731 | static void tcp_release_cb_override(struct sock *ssk) |
1732 | { | |
1733 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1734 | ||
1735 | if (mptcp_subflow_has_delegated_action(subflow)) | |
1736 | mptcp_subflow_process_delegated(ssk); | |
1737 | ||
1738 | tcp_release_cb(ssk); | |
1739 | } | |
1740 | ||
2303f994 PK |
1741 | static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { |
1742 | .name = "mptcp", | |
1743 | .owner = THIS_MODULE, | |
1744 | .init = subflow_ulp_init, | |
1745 | .release = subflow_ulp_release, | |
cec37a6e | 1746 | .clone = subflow_ulp_clone, |
2303f994 PK |
1747 | }; |
1748 | ||
cec37a6e PK |
1749 | static int subflow_ops_init(struct request_sock_ops *subflow_ops) |
1750 | { | |
1751 | subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock); | |
1752 | subflow_ops->slab_name = "request_sock_subflow"; | |
1753 | ||
1754 | subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name, | |
1755 | subflow_ops->obj_size, 0, | |
1756 | SLAB_ACCOUNT | | |
1757 | SLAB_TYPESAFE_BY_RCU, | |
1758 | NULL); | |
1759 | if (!subflow_ops->slab) | |
1760 | return -ENOMEM; | |
1761 | ||
79c0949e PK |
1762 | subflow_ops->destructor = subflow_req_destructor; |
1763 | ||
cec37a6e PK |
1764 | return 0; |
1765 | } | |
1766 | ||
d39dceca | 1767 | void __init mptcp_subflow_init(void) |
2303f994 | 1768 | { |
08b8d080 FW |
1769 | mptcp_subflow_request_sock_ops = tcp_request_sock_ops; |
1770 | if (subflow_ops_init(&mptcp_subflow_request_sock_ops) != 0) | |
cec37a6e PK |
1771 | panic("MPTCP: failed to init subflow request sock ops\n"); |
1772 | ||
1773 | subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops; | |
7ea851d1 | 1774 | subflow_request_sock_ipv4_ops.route_req = subflow_v4_route_req; |
cec37a6e PK |
1775 | |
1776 | subflow_specific = ipv4_specific; | |
1777 | subflow_specific.conn_request = subflow_v4_conn_request; | |
1778 | subflow_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1779 | subflow_specific.sk_rx_dst_set = subflow_finish_connect; | |
1780 | ||
b19bc294 PA |
1781 | tcp_prot_override = tcp_prot; |
1782 | tcp_prot_override.release_cb = tcp_release_cb_override; | |
1783 | ||
cec37a6e PK |
1784 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
1785 | subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; | |
7ea851d1 | 1786 | subflow_request_sock_ipv6_ops.route_req = subflow_v6_route_req; |
cec37a6e PK |
1787 | |
1788 | subflow_v6_specific = ipv6_specific; | |
1789 | subflow_v6_specific.conn_request = subflow_v6_conn_request; | |
1790 | subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1791 | subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect; | |
1792 | ||
1793 | subflow_v6m_specific = subflow_v6_specific; | |
1794 | subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit; | |
1795 | subflow_v6m_specific.send_check = ipv4_specific.send_check; | |
1796 | subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; | |
1797 | subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; | |
1798 | subflow_v6m_specific.net_frag_header_len = 0; | |
b19bc294 PA |
1799 | |
1800 | tcpv6_prot_override = tcpv6_prot; | |
1801 | tcpv6_prot_override.release_cb = tcp_release_cb_override; | |
cec37a6e PK |
1802 | #endif |
1803 | ||
5147dfb5 DC |
1804 | mptcp_diag_subflow_init(&subflow_ulp_ops); |
1805 | ||
2303f994 PK |
1806 | if (tcp_register_ulp(&subflow_ulp_ops) != 0) |
1807 | panic("MPTCP: failed to register subflows to ULP\n"); | |
1808 | } |