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) && | |
4d25247d KM |
65 | ((mptcp_pm_is_userspace(msk) && |
66 | mptcp_userspace_pm_active(msk)) || | |
67 | READ_ONCE(msk->pm.accept_subflow)); | |
4cf8b7e4 PA |
68 | } |
69 | ||
f296234c | 70 | /* validate received token and create truncated hmac and nonce for SYN-ACK */ |
ec20e143 GT |
71 | static void subflow_req_create_thmac(struct mptcp_subflow_request_sock *subflow_req) |
72 | { | |
73 | struct mptcp_sock *msk = subflow_req->msk; | |
74 | u8 hmac[SHA256_DIGEST_SIZE]; | |
75 | ||
76 | get_random_bytes(&subflow_req->local_nonce, sizeof(u32)); | |
77 | ||
78 | subflow_generate_hmac(msk->local_key, msk->remote_key, | |
79 | subflow_req->local_nonce, | |
80 | subflow_req->remote_nonce, hmac); | |
81 | ||
82 | subflow_req->thmac = get_unaligned_be64(hmac); | |
83 | } | |
84 | ||
b5e2e42f | 85 | static struct mptcp_sock *subflow_token_join_request(struct request_sock *req) |
f296234c PK |
86 | { |
87 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
f296234c PK |
88 | struct mptcp_sock *msk; |
89 | int local_id; | |
90 | ||
ea1300b9 | 91 | msk = mptcp_token_get_sock(sock_net(req_to_sk(req)), subflow_req->token); |
f296234c | 92 | if (!msk) { |
fc518953 | 93 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINNOTOKEN); |
8fd4de12 | 94 | return NULL; |
f296234c PK |
95 | } |
96 | ||
97 | local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); | |
98 | if (local_id < 0) { | |
99 | sock_put((struct sock *)msk); | |
8fd4de12 | 100 | return NULL; |
f296234c PK |
101 | } |
102 | subflow_req->local_id = local_id; | |
103 | ||
8fd4de12 | 104 | return msk; |
f296234c PK |
105 | } |
106 | ||
d8b59efa | 107 | static void subflow_init_req(struct request_sock *req, const struct sock *sk_listener) |
cec37a6e | 108 | { |
cec37a6e | 109 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); |
cec37a6e PK |
110 | |
111 | subflow_req->mp_capable = 0; | |
f296234c | 112 | subflow_req->mp_join = 0; |
06fe1719 | 113 | subflow_req->csum_reqd = mptcp_is_checksum_enabled(sock_net(sk_listener)); |
bab6b88e | 114 | subflow_req->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk_listener)); |
8fd4de12 | 115 | subflow_req->msk = NULL; |
2c5ebd00 | 116 | mptcp_token_init_request(req); |
78d8b7bc FW |
117 | } |
118 | ||
5bc56388 GT |
119 | static bool subflow_use_different_sport(struct mptcp_sock *msk, const struct sock *sk) |
120 | { | |
121 | return inet_sk(sk)->inet_sport != inet_sk((struct sock *)msk)->inet_sport; | |
122 | } | |
123 | ||
dc87efdb FW |
124 | static void subflow_add_reset_reason(struct sk_buff *skb, u8 reason) |
125 | { | |
126 | struct mptcp_ext *mpext = skb_ext_add(skb, SKB_EXT_MPTCP); | |
127 | ||
128 | if (mpext) { | |
129 | memset(mpext, 0, sizeof(*mpext)); | |
130 | mpext->reset_reason = reason; | |
131 | } | |
132 | } | |
133 | ||
3ecfbe3e FW |
134 | /* Init mptcp request socket. |
135 | * | |
136 | * Returns an error code if a JOIN has failed and a TCP reset | |
137 | * should be sent. | |
138 | */ | |
d8b59efa PA |
139 | static int subflow_check_req(struct request_sock *req, |
140 | const struct sock *sk_listener, | |
141 | struct sk_buff *skb) | |
78d8b7bc FW |
142 | { |
143 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
144 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
145 | struct mptcp_options_received mp_opt; | |
74c7dfbe | 146 | bool opt_mp_capable, opt_mp_join; |
78d8b7bc FW |
147 | |
148 | pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); | |
149 | ||
d8b59efa PA |
150 | #ifdef CONFIG_TCP_MD5SIG |
151 | /* no MPTCP if MD5SIG is enabled on this socket or we may run out of | |
152 | * TCP option space. | |
153 | */ | |
154 | if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) | |
155 | return -EINVAL; | |
156 | #endif | |
78d8b7bc | 157 | |
0799e21b | 158 | mptcp_get_options(skb, &mp_opt); |
78d8b7bc | 159 | |
74c7dfbe PA |
160 | opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC); |
161 | opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ); | |
162 | if (opt_mp_capable) { | |
fc518953 FW |
163 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); |
164 | ||
74c7dfbe | 165 | if (opt_mp_join) |
3ecfbe3e | 166 | return 0; |
74c7dfbe | 167 | } else if (opt_mp_join) { |
fc518953 FW |
168 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); |
169 | } | |
f296234c | 170 | |
74c7dfbe | 171 | if (opt_mp_capable && listener->request_mptcp) { |
c68a0cd1 | 172 | int err, retries = MPTCP_TOKEN_MAX_RETRIES; |
535fb815 | 173 | |
c83a47e5 | 174 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
535fb815 FW |
175 | again: |
176 | do { | |
177 | get_random_bytes(&subflow_req->local_key, sizeof(subflow_req->local_key)); | |
178 | } while (subflow_req->local_key == 0); | |
79c0949e | 179 | |
c83a47e5 FW |
180 | if (unlikely(req->syncookie)) { |
181 | mptcp_crypto_key_sha(subflow_req->local_key, | |
182 | &subflow_req->token, | |
183 | &subflow_req->idsn); | |
184 | if (mptcp_token_exists(subflow_req->token)) { | |
185 | if (retries-- > 0) | |
186 | goto again; | |
a16195e3 | 187 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT); |
c83a47e5 FW |
188 | } else { |
189 | subflow_req->mp_capable = 1; | |
190 | } | |
3ecfbe3e | 191 | return 0; |
c83a47e5 FW |
192 | } |
193 | ||
79c0949e PK |
194 | err = mptcp_token_new_request(req); |
195 | if (err == 0) | |
196 | subflow_req->mp_capable = 1; | |
535fb815 FW |
197 | else if (retries-- > 0) |
198 | goto again; | |
a16195e3 PA |
199 | else |
200 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT); | |
79c0949e | 201 | |
74c7dfbe | 202 | } else if (opt_mp_join && listener->request_mptcp) { |
ec3edaa7 | 203 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
f296234c | 204 | subflow_req->mp_join = 1; |
cfde141e PA |
205 | subflow_req->backup = mp_opt.backup; |
206 | subflow_req->remote_id = mp_opt.join_id; | |
207 | subflow_req->token = mp_opt.token; | |
208 | subflow_req->remote_nonce = mp_opt.nonce; | |
b5e2e42f | 209 | subflow_req->msk = subflow_token_join_request(req); |
9466a1cc | 210 | |
3ecfbe3e | 211 | /* Can't fall back to TCP in this case. */ |
dc87efdb FW |
212 | if (!subflow_req->msk) { |
213 | subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); | |
3ecfbe3e | 214 | return -EPERM; |
dc87efdb | 215 | } |
3ecfbe3e | 216 | |
5bc56388 GT |
217 | if (subflow_use_different_sport(subflow_req->msk, sk_listener)) { |
218 | pr_debug("syn inet_sport=%d %d", | |
219 | ntohs(inet_sk(sk_listener)->inet_sport), | |
220 | ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport)); | |
221 | if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) { | |
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); | |
8547ea5f JW |
233 | else |
234 | return -EPERM; | |
9466a1cc FW |
235 | } |
236 | ||
8fd4de12 PA |
237 | pr_debug("token=%u, remote_nonce=%u msk=%p", subflow_req->token, |
238 | subflow_req->remote_nonce, subflow_req->msk); | |
cec37a6e | 239 | } |
3ecfbe3e FW |
240 | |
241 | return 0; | |
cec37a6e PK |
242 | } |
243 | ||
c83a47e5 FW |
244 | int mptcp_subflow_init_cookie_req(struct request_sock *req, |
245 | const struct sock *sk_listener, | |
246 | struct sk_buff *skb) | |
247 | { | |
248 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
249 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
250 | struct mptcp_options_received mp_opt; | |
74c7dfbe | 251 | bool opt_mp_capable, opt_mp_join; |
c83a47e5 FW |
252 | int err; |
253 | ||
d8b59efa | 254 | subflow_init_req(req, sk_listener); |
0799e21b | 255 | mptcp_get_options(skb, &mp_opt); |
c83a47e5 | 256 | |
74c7dfbe PA |
257 | opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC); |
258 | opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ); | |
259 | if (opt_mp_capable && opt_mp_join) | |
c83a47e5 FW |
260 | return -EINVAL; |
261 | ||
74c7dfbe | 262 | if (opt_mp_capable && listener->request_mptcp) { |
c83a47e5 FW |
263 | if (mp_opt.sndr_key == 0) |
264 | return -EINVAL; | |
265 | ||
266 | subflow_req->local_key = mp_opt.rcvr_key; | |
267 | err = mptcp_token_new_request(req); | |
268 | if (err) | |
269 | return err; | |
270 | ||
271 | subflow_req->mp_capable = 1; | |
272 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; | |
74c7dfbe | 273 | } else if (opt_mp_join && listener->request_mptcp) { |
9466a1cc FW |
274 | if (!mptcp_token_join_cookie_init_state(subflow_req, skb)) |
275 | return -EINVAL; | |
276 | ||
8547ea5f | 277 | subflow_req->mp_join = 1; |
9466a1cc | 278 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; |
c83a47e5 FW |
279 | } |
280 | ||
281 | return 0; | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); | |
284 | ||
7ea851d1 FW |
285 | static struct dst_entry *subflow_v4_route_req(const struct sock *sk, |
286 | struct sk_buff *skb, | |
287 | struct flowi *fl, | |
288 | struct request_sock *req) | |
cec37a6e | 289 | { |
7ea851d1 | 290 | struct dst_entry *dst; |
3ecfbe3e | 291 | int err; |
7ea851d1 | 292 | |
cec37a6e | 293 | tcp_rsk(req)->is_mptcp = 1; |
d8b59efa | 294 | subflow_init_req(req, sk); |
cec37a6e | 295 | |
7ea851d1 FW |
296 | dst = tcp_request_sock_ipv4_ops.route_req(sk, skb, fl, req); |
297 | if (!dst) | |
298 | return NULL; | |
cec37a6e | 299 | |
d8b59efa | 300 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
301 | if (err == 0) |
302 | return dst; | |
cec37a6e | 303 | |
3ecfbe3e FW |
304 | dst_release(dst); |
305 | if (!req->syncookie) | |
306 | tcp_request_sock_ops.send_reset(sk, skb); | |
307 | return NULL; | |
cec37a6e PK |
308 | } |
309 | ||
310 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
7ea851d1 FW |
311 | static struct dst_entry *subflow_v6_route_req(const struct sock *sk, |
312 | struct sk_buff *skb, | |
313 | struct flowi *fl, | |
314 | struct request_sock *req) | |
cec37a6e | 315 | { |
7ea851d1 | 316 | struct dst_entry *dst; |
3ecfbe3e | 317 | int err; |
7ea851d1 | 318 | |
cec37a6e | 319 | tcp_rsk(req)->is_mptcp = 1; |
d8b59efa | 320 | subflow_init_req(req, sk); |
cec37a6e | 321 | |
7ea851d1 FW |
322 | dst = tcp_request_sock_ipv6_ops.route_req(sk, skb, fl, req); |
323 | if (!dst) | |
324 | return NULL; | |
cec37a6e | 325 | |
d8b59efa | 326 | err = subflow_check_req(req, sk, skb); |
3ecfbe3e FW |
327 | if (err == 0) |
328 | return dst; | |
329 | ||
330 | dst_release(dst); | |
331 | if (!req->syncookie) | |
332 | tcp6_request_sock_ops.send_reset(sk, skb); | |
333 | return NULL; | |
cec37a6e PK |
334 | } |
335 | #endif | |
336 | ||
ec3edaa7 PK |
337 | /* validate received truncated hmac and create hmac for third ACK */ |
338 | static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) | |
339 | { | |
bd697222 | 340 | u8 hmac[SHA256_DIGEST_SIZE]; |
ec3edaa7 PK |
341 | u64 thmac; |
342 | ||
343 | subflow_generate_hmac(subflow->remote_key, subflow->local_key, | |
344 | subflow->remote_nonce, subflow->local_nonce, | |
345 | hmac); | |
346 | ||
347 | thmac = get_unaligned_be64(hmac); | |
348 | pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", | |
742e2f36 | 349 | subflow, subflow->token, thmac, subflow->thmac); |
ec3edaa7 PK |
350 | |
351 | return thmac == subflow->thmac; | |
352 | } | |
353 | ||
d5824847 PA |
354 | void mptcp_subflow_reset(struct sock *ssk) |
355 | { | |
0e4f35d7 PA |
356 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); |
357 | struct sock *sk = subflow->conn; | |
358 | ||
ab82e996 FW |
359 | /* must hold: tcp_done() could drop last reference on parent */ |
360 | sock_hold(sk); | |
361 | ||
d5824847 PA |
362 | tcp_set_state(ssk, TCP_CLOSE); |
363 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
364 | tcp_done(ssk); | |
0e4f35d7 PA |
365 | if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && |
366 | schedule_work(&mptcp_sk(sk)->work)) | |
ab82e996 FW |
367 | return; /* worker will put sk for us */ |
368 | ||
369 | sock_put(sk); | |
d5824847 PA |
370 | } |
371 | ||
5bc56388 GT |
372 | static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct sock *sk) |
373 | { | |
374 | return inet_sk(sk)->inet_dport != inet_sk((struct sock *)msk)->inet_dport; | |
375 | } | |
376 | ||
490274b4 PA |
377 | void __mptcp_set_connected(struct sock *sk) |
378 | { | |
379 | if (sk->sk_state == TCP_SYN_SENT) { | |
380 | inet_sk_state_store(sk, TCP_ESTABLISHED); | |
381 | sk->sk_state_change(sk); | |
382 | } | |
383 | } | |
384 | ||
385 | static void mptcp_set_connected(struct sock *sk) | |
386 | { | |
387 | mptcp_data_lock(sk); | |
388 | if (!sock_owned_by_user(sk)) | |
389 | __mptcp_set_connected(sk); | |
390 | else | |
e9d09bac | 391 | __set_bit(MPTCP_CONNECTED, &mptcp_sk(sk)->cb_flags); |
490274b4 PA |
392 | mptcp_data_unlock(sk); |
393 | } | |
394 | ||
cec37a6e PK |
395 | static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) |
396 | { | |
397 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cfde141e | 398 | struct mptcp_options_received mp_opt; |
c3c123d1 | 399 | struct sock *parent = subflow->conn; |
cec37a6e PK |
400 | |
401 | subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); | |
402 | ||
263e1201 PA |
403 | /* be sure no special action on any packet other than syn-ack */ |
404 | if (subflow->conn_finished) | |
405 | return; | |
406 | ||
5cf92bba | 407 | mptcp_propagate_sndbuf(parent, sk); |
b0977bb2 | 408 | subflow->rel_write_seq = 1; |
263e1201 | 409 | subflow->conn_finished = 1; |
e1ff9e82 DC |
410 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; |
411 | pr_debug("subflow=%p synack seq=%x", subflow, subflow->ssn_offset); | |
263e1201 | 412 | |
0799e21b | 413 | mptcp_get_options(skb, &mp_opt); |
fa25e815 | 414 | if (subflow->request_mptcp) { |
74c7dfbe | 415 | if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) { |
fa25e815 PA |
416 | MPTCP_INC_STATS(sock_net(sk), |
417 | MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); | |
418 | mptcp_do_fallback(sk); | |
419 | pr_fallback(mptcp_sk(subflow->conn)); | |
420 | goto fallback; | |
421 | } | |
422 | ||
74c7dfbe | 423 | if (mp_opt.suboptions & OPTION_MPTCP_CSUMREQD) |
06251181 | 424 | WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true); |
df377be3 GT |
425 | if (mp_opt.deny_join_id0) |
426 | WRITE_ONCE(mptcp_sk(parent)->pm.remote_deny_join_id0, true); | |
263e1201 PA |
427 | subflow->mp_capable = 1; |
428 | subflow->can_ack = 1; | |
cfde141e | 429 | subflow->remote_key = mp_opt.sndr_key; |
263e1201 PA |
430 | pr_debug("subflow=%p, remote_key=%llu", subflow, |
431 | subflow->remote_key); | |
5695eb88 | 432 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEACK); |
fa25e815 | 433 | mptcp_finish_connect(sk); |
490274b4 | 434 | mptcp_set_connected(parent); |
fa25e815 PA |
435 | } else if (subflow->request_join) { |
436 | u8 hmac[SHA256_DIGEST_SIZE]; | |
437 | ||
74c7dfbe | 438 | if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ)) { |
dc87efdb | 439 | subflow->reset_reason = MPTCP_RST_EMPTCP; |
fa25e815 | 440 | goto do_reset; |
dc87efdb | 441 | } |
fa25e815 | 442 | |
0460ce22 | 443 | subflow->backup = mp_opt.backup; |
cfde141e PA |
444 | subflow->thmac = mp_opt.thmac; |
445 | subflow->remote_nonce = mp_opt.nonce; | |
8a348392 | 446 | subflow->remote_id = mp_opt.join_id; |
0460ce22 PA |
447 | pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u backup=%d", |
448 | subflow, subflow->thmac, subflow->remote_nonce, | |
449 | subflow->backup); | |
263e1201 | 450 | |
ec3edaa7 | 451 | if (!subflow_thmac_valid(subflow)) { |
fc518953 | 452 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC); |
dc87efdb | 453 | subflow->reset_reason = MPTCP_RST_EMPTCP; |
ec3edaa7 PK |
454 | goto do_reset; |
455 | } | |
456 | ||
0a4d8e96 JW |
457 | if (!mptcp_finish_join(sk)) |
458 | goto do_reset; | |
459 | ||
ec3edaa7 PK |
460 | subflow_generate_hmac(subflow->local_key, subflow->remote_key, |
461 | subflow->local_nonce, | |
462 | subflow->remote_nonce, | |
bd697222 | 463 | hmac); |
bd697222 | 464 | memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN); |
ec3edaa7 | 465 | |
fa25e815 | 466 | subflow->mp_join = 1; |
fc518953 | 467 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); |
5bc56388 GT |
468 | |
469 | if (subflow_use_different_dport(mptcp_sk(parent), sk)) { | |
470 | pr_debug("synack inet_dport=%d %d", | |
471 | ntohs(inet_sk(sk)->inet_dport), | |
472 | ntohs(inet_sk(parent)->inet_dport)); | |
2fbdd9ea | 473 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINPORTSYNACKRX); |
5bc56388 | 474 | } |
fa25e815 PA |
475 | } else if (mptcp_check_fallback(sk)) { |
476 | fallback: | |
477 | mptcp_rcv_space_init(mptcp_sk(parent), sk); | |
490274b4 | 478 | mptcp_set_connected(parent); |
cec37a6e | 479 | } |
fa25e815 PA |
480 | return; |
481 | ||
482 | do_reset: | |
dc87efdb | 483 | subflow->reset_transient = 0; |
d5824847 | 484 | mptcp_subflow_reset(sk); |
cec37a6e PK |
485 | } |
486 | ||
4cf86ae8 PA |
487 | static void subflow_set_local_id(struct mptcp_subflow_context *subflow, int local_id) |
488 | { | |
489 | subflow->local_id = local_id; | |
490 | subflow->local_id_valid = 1; | |
491 | } | |
492 | ||
493 | static int subflow_chk_local_id(struct sock *sk) | |
494 | { | |
495 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
496 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
497 | int err; | |
498 | ||
499 | if (likely(subflow->local_id_valid)) | |
500 | return 0; | |
501 | ||
502 | err = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); | |
503 | if (err < 0) | |
504 | return err; | |
505 | ||
506 | subflow_set_local_id(subflow, err); | |
507 | return 0; | |
508 | } | |
509 | ||
510 | static int subflow_rebuild_header(struct sock *sk) | |
511 | { | |
512 | int err = subflow_chk_local_id(sk); | |
513 | ||
514 | if (unlikely(err < 0)) | |
515 | return err; | |
516 | ||
517 | return inet_sk_rebuild_header(sk); | |
518 | } | |
519 | ||
520 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
521 | static int subflow_v6_rebuild_header(struct sock *sk) | |
522 | { | |
523 | int err = subflow_chk_local_id(sk); | |
524 | ||
525 | if (unlikely(err < 0)) | |
526 | return err; | |
527 | ||
528 | return inet6_sk_rebuild_header(sk); | |
529 | } | |
530 | #endif | |
531 | ||
08b8d080 | 532 | struct request_sock_ops mptcp_subflow_request_sock_ops; |
51fa7f8e | 533 | static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops __ro_after_init; |
cec37a6e PK |
534 | |
535 | static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
536 | { | |
537 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
538 | ||
539 | pr_debug("subflow=%p", subflow); | |
540 | ||
541 | /* Never answer to SYNs sent to broadcast or multicast */ | |
542 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
543 | goto drop; | |
544 | ||
08b8d080 | 545 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
546 | &subflow_request_sock_ipv4_ops, |
547 | sk, skb); | |
548 | drop: | |
549 | tcp_listendrop(sk); | |
550 | return 0; | |
551 | } | |
552 | ||
553 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
51fa7f8e FW |
554 | static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops __ro_after_init; |
555 | static struct inet_connection_sock_af_ops subflow_v6_specific __ro_after_init; | |
556 | static struct inet_connection_sock_af_ops subflow_v6m_specific __ro_after_init; | |
b19bc294 | 557 | static struct proto tcpv6_prot_override; |
cec37a6e PK |
558 | |
559 | static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) | |
560 | { | |
561 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
562 | ||
563 | pr_debug("subflow=%p", subflow); | |
564 | ||
565 | if (skb->protocol == htons(ETH_P_IP)) | |
566 | return subflow_v4_conn_request(sk, skb); | |
567 | ||
568 | if (!ipv6_unicast_destination(skb)) | |
569 | goto drop; | |
570 | ||
dcc32f4f JK |
571 | if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { |
572 | __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); | |
573 | return 0; | |
574 | } | |
575 | ||
08b8d080 | 576 | return tcp_conn_request(&mptcp_subflow_request_sock_ops, |
cec37a6e PK |
577 | &subflow_request_sock_ipv6_ops, sk, skb); |
578 | ||
579 | drop: | |
580 | tcp_listendrop(sk); | |
581 | return 0; /* don't send reset */ | |
582 | } | |
583 | #endif | |
584 | ||
f296234c PK |
585 | /* validate hmac received in third ACK */ |
586 | static bool subflow_hmac_valid(const struct request_sock *req, | |
cfde141e | 587 | const struct mptcp_options_received *mp_opt) |
f296234c PK |
588 | { |
589 | const struct mptcp_subflow_request_sock *subflow_req; | |
bd697222 | 590 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c | 591 | struct mptcp_sock *msk; |
f296234c PK |
592 | |
593 | subflow_req = mptcp_subflow_rsk(req); | |
8fd4de12 | 594 | msk = subflow_req->msk; |
f296234c PK |
595 | if (!msk) |
596 | return false; | |
597 | ||
598 | subflow_generate_hmac(msk->remote_key, msk->local_key, | |
599 | subflow_req->remote_nonce, | |
600 | subflow_req->local_nonce, hmac); | |
601 | ||
8fd4de12 | 602 | return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN); |
f296234c PK |
603 | } |
604 | ||
df1036da FW |
605 | static void mptcp_sock_destruct(struct sock *sk) |
606 | { | |
607 | /* if new mptcp socket isn't accepted, it is free'd | |
608 | * from the tcp listener sockets request queue, linked | |
609 | * from req->sk. The tcp socket is released. | |
610 | * This calls the ULP release function which will | |
611 | * also remove the mptcp socket, via | |
612 | * sock_put(ctx->conn). | |
613 | * | |
7ee24926 PA |
614 | * Problem is that the mptcp socket will be in |
615 | * ESTABLISHED state and will not have the SOCK_DEAD flag. | |
df1036da FW |
616 | * Both result in warnings from inet_sock_destruct. |
617 | */ | |
578c18ef | 618 | if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { |
df1036da FW |
619 | sk->sk_state = TCP_CLOSE; |
620 | WARN_ON_ONCE(sk->sk_socket); | |
621 | sock_orphan(sk); | |
622 | } | |
623 | ||
5c8c1640 | 624 | mptcp_destroy_common(mptcp_sk(sk)); |
df1036da FW |
625 | inet_sock_destruct(sk); |
626 | } | |
627 | ||
9f5ca6a5 FW |
628 | static void mptcp_force_close(struct sock *sk) |
629 | { | |
490274b4 | 630 | /* the msk is not yet exposed to user-space */ |
9f5ca6a5 FW |
631 | inet_sk_state_store(sk, TCP_CLOSE); |
632 | sk_common_release(sk); | |
633 | } | |
634 | ||
4c8941de PA |
635 | static void subflow_ulp_fallback(struct sock *sk, |
636 | struct mptcp_subflow_context *old_ctx) | |
637 | { | |
638 | struct inet_connection_sock *icsk = inet_csk(sk); | |
639 | ||
640 | mptcp_subflow_tcp_fallback(sk, old_ctx); | |
641 | icsk->icsk_ulp_ops = NULL; | |
642 | rcu_assign_pointer(icsk->icsk_ulp_data, NULL); | |
643 | tcp_sk(sk)->is_mptcp = 0; | |
b19bc294 PA |
644 | |
645 | mptcp_subflow_ops_undo_override(sk); | |
4c8941de PA |
646 | } |
647 | ||
39884604 PA |
648 | static void subflow_drop_ctx(struct sock *ssk) |
649 | { | |
650 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); | |
651 | ||
652 | if (!ctx) | |
653 | return; | |
654 | ||
655 | subflow_ulp_fallback(ssk, ctx); | |
656 | if (ctx->conn) | |
657 | sock_put(ctx->conn); | |
658 | ||
659 | kfree_rcu(ctx, rcu); | |
660 | } | |
661 | ||
b93df08c PA |
662 | void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, |
663 | struct mptcp_options_received *mp_opt) | |
664 | { | |
665 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
666 | ||
667 | subflow->remote_key = mp_opt->sndr_key; | |
668 | subflow->fully_established = 1; | |
669 | subflow->can_ack = 1; | |
670 | WRITE_ONCE(msk->fully_established, true); | |
671 | } | |
672 | ||
cec37a6e PK |
673 | static struct sock *subflow_syn_recv_sock(const struct sock *sk, |
674 | struct sk_buff *skb, | |
675 | struct request_sock *req, | |
676 | struct dst_entry *dst, | |
677 | struct request_sock *req_unhash, | |
678 | bool *own_req) | |
679 | { | |
680 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk); | |
cc7972ea | 681 | struct mptcp_subflow_request_sock *subflow_req; |
cfde141e | 682 | struct mptcp_options_received mp_opt; |
9e365ff5 | 683 | bool fallback, fallback_is_fatal; |
58b09919 | 684 | struct sock *new_msk = NULL; |
cec37a6e PK |
685 | struct sock *child; |
686 | ||
687 | pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); | |
688 | ||
74c7dfbe | 689 | /* After child creation we must look for MPC even when options |
9e365ff5 | 690 | * are not parsed |
cfde141e | 691 | */ |
74c7dfbe | 692 | mp_opt.suboptions = 0; |
9e365ff5 PA |
693 | |
694 | /* hopefully temporary handling for MP_JOIN+syncookie */ | |
695 | subflow_req = mptcp_subflow_rsk(req); | |
b7514694 | 696 | fallback_is_fatal = tcp_rsk(req)->is_mptcp && subflow_req->mp_join; |
9e365ff5 PA |
697 | fallback = !tcp_rsk(req)->is_mptcp; |
698 | if (fallback) | |
ae2dd716 FW |
699 | goto create_child; |
700 | ||
d22f4988 | 701 | /* if the sk is MP_CAPABLE, we try to fetch the client key */ |
cc7972ea | 702 | if (subflow_req->mp_capable) { |
06f9a435 PA |
703 | /* we can receive and accept an in-window, out-of-order pkt, |
704 | * which may not carry the MP_CAPABLE opt even on mptcp enabled | |
705 | * paths: always try to extract the peer key, and fallback | |
706 | * for packets missing it. | |
707 | * Even OoO DSS packets coming legitly after dropped or | |
708 | * reordered MPC will cause fallback, but we don't have other | |
709 | * options. | |
710 | */ | |
0799e21b | 711 | mptcp_get_options(skb, &mp_opt); |
74c7dfbe | 712 | if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) { |
4c8941de | 713 | fallback = true; |
58b09919 | 714 | goto create_child; |
d22f4988 | 715 | } |
58b09919 | 716 | |
cfde141e | 717 | new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); |
58b09919 | 718 | if (!new_msk) |
4c8941de | 719 | fallback = true; |
f296234c | 720 | } else if (subflow_req->mp_join) { |
0799e21b | 721 | mptcp_get_options(skb, &mp_opt); |
74c7dfbe PA |
722 | if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ) || |
723 | !subflow_hmac_valid(req, &mp_opt) || | |
d3ab7885 | 724 | !mptcp_can_accept_new_subflow(subflow_req->msk)) { |
fc518953 | 725 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); |
9e365ff5 | 726 | fallback = true; |
fc518953 | 727 | } |
cc7972ea | 728 | } |
cec37a6e | 729 | |
d22f4988 | 730 | create_child: |
cec37a6e PK |
731 | child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, |
732 | req_unhash, own_req); | |
733 | ||
734 | if (child && *own_req) { | |
79c0949e PK |
735 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); |
736 | ||
90bf4513 PA |
737 | tcp_rsk(req)->drop_req = false; |
738 | ||
4c8941de PA |
739 | /* we need to fallback on ctx allocation failure and on pre-reqs |
740 | * checking above. In the latter scenario we additionally need | |
741 | * to reset the context to non MPTCP status. | |
79c0949e | 742 | */ |
4c8941de | 743 | if (!ctx || fallback) { |
dc87efdb FW |
744 | if (fallback_is_fatal) { |
745 | subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); | |
729cd643 | 746 | goto dispose_child; |
dc87efdb | 747 | } |
4c8941de | 748 | |
39884604 | 749 | subflow_drop_ctx(child); |
58b09919 | 750 | goto out; |
f296234c | 751 | } |
79c0949e | 752 | |
df00b087 FW |
753 | /* ssk inherits options of listener sk */ |
754 | ctx->setsockopt_seq = listener->setsockopt_seq; | |
755 | ||
79c0949e | 756 | if (ctx->mp_capable) { |
b93df08c PA |
757 | /* this can't race with mptcp_close(), as the msk is |
758 | * not yet exposted to user-space | |
759 | */ | |
760 | inet_sk_state_store((void *)new_msk, TCP_ESTABLISHED); | |
761 | ||
5b950ff4 PA |
762 | /* record the newly created socket as the first msk |
763 | * subflow, but don't link it yet into conn_list | |
764 | */ | |
0397c6d8 PA |
765 | WRITE_ONCE(mptcp_sk(new_msk)->first, child); |
766 | ||
58b09919 PA |
767 | /* new mpc subflow takes ownership of the newly |
768 | * created mptcp socket | |
769 | */ | |
df1036da | 770 | new_msk->sk_destruct = mptcp_sock_destruct; |
df00b087 | 771 | mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq; |
6c714f1b | 772 | mptcp_pm_new_connection(mptcp_sk(new_msk), child, 1); |
2c5ebd00 | 773 | mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); |
58b09919 PA |
774 | ctx->conn = new_msk; |
775 | new_msk = NULL; | |
fca5c82c PA |
776 | |
777 | /* with OoO packets we can reach here without ingress | |
778 | * mpc option | |
779 | */ | |
74c7dfbe | 780 | if (mp_opt.suboptions & OPTIONS_MPTCP_MPC) |
b93df08c | 781 | mptcp_subflow_fully_established(ctx, &mp_opt); |
f296234c PK |
782 | } else if (ctx->mp_join) { |
783 | struct mptcp_sock *owner; | |
784 | ||
8fd4de12 | 785 | owner = subflow_req->msk; |
dc87efdb FW |
786 | if (!owner) { |
787 | subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT); | |
729cd643 | 788 | goto dispose_child; |
dc87efdb | 789 | } |
f296234c | 790 | |
8fd4de12 PA |
791 | /* move the msk reference ownership to the subflow */ |
792 | subflow_req->msk = NULL; | |
f296234c | 793 | ctx->conn = (struct sock *)owner; |
5bc56388 GT |
794 | |
795 | if (subflow_use_different_sport(owner, sk)) { | |
796 | pr_debug("ack inet_sport=%d %d", | |
797 | ntohs(inet_sk(sk)->inet_sport), | |
798 | ntohs(inet_sk((struct sock *)owner)->inet_sport)); | |
2fbdd9ea GT |
799 | if (!mptcp_pm_sport_in_anno_list(owner, sk)) { |
800 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTACKRX); | |
9238e900 | 801 | goto dispose_child; |
2fbdd9ea GT |
802 | } |
803 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINPORTACKRX); | |
5bc56388 | 804 | } |
9238e900 GT |
805 | |
806 | if (!mptcp_finish_join(child)) | |
807 | goto dispose_child; | |
808 | ||
809 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); | |
810 | tcp_rsk(req)->drop_req = true; | |
cec37a6e PK |
811 | } |
812 | } | |
813 | ||
58b09919 PA |
814 | out: |
815 | /* dispose of the left over mptcp master, if any */ | |
816 | if (unlikely(new_msk)) | |
9f5ca6a5 | 817 | mptcp_force_close(new_msk); |
4c8941de PA |
818 | |
819 | /* check for expected invariant - should never trigger, just help | |
820 | * catching eariler subtle bugs | |
821 | */ | |
ac2b47fb | 822 | WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp && |
4c8941de PA |
823 | (!mptcp_subflow_ctx(child) || |
824 | !mptcp_subflow_ctx(child)->conn)); | |
cec37a6e | 825 | return child; |
f296234c | 826 | |
729cd643 | 827 | dispose_child: |
39884604 | 828 | subflow_drop_ctx(child); |
729cd643 | 829 | tcp_rsk(req)->drop_req = true; |
729cd643 | 830 | inet_csk_prepare_for_destroy_sock(child); |
f296234c | 831 | tcp_done(child); |
97e61751 | 832 | req->rsk_ops->send_reset(sk, skb); |
729cd643 PA |
833 | |
834 | /* The last child reference will be released by the caller */ | |
835 | return child; | |
cec37a6e PK |
836 | } |
837 | ||
51fa7f8e | 838 | static struct inet_connection_sock_af_ops subflow_specific __ro_after_init; |
b19bc294 | 839 | static struct proto tcp_prot_override; |
cec37a6e | 840 | |
648ef4b8 MM |
841 | enum mapping_status { |
842 | MAPPING_OK, | |
843 | MAPPING_INVALID, | |
844 | MAPPING_EMPTY, | |
e1ff9e82 | 845 | MAPPING_DATA_FIN, |
31bf11de PA |
846 | MAPPING_DUMMY, |
847 | MAPPING_BAD_CSUM | |
648ef4b8 MM |
848 | }; |
849 | ||
61e71022 | 850 | static void dbg_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) |
648ef4b8 | 851 | { |
61e71022 PA |
852 | pr_debug("Bad mapping: ssn=%d map_seq=%d map_data_len=%d", |
853 | ssn, subflow->map_subflow_seq, subflow->map_data_len); | |
648ef4b8 MM |
854 | } |
855 | ||
856 | static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) | |
857 | { | |
858 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
859 | unsigned int skb_consumed; | |
860 | ||
861 | skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; | |
862 | if (WARN_ON_ONCE(skb_consumed >= skb->len)) | |
863 | return true; | |
864 | ||
865 | return skb->len - skb_consumed <= subflow->map_data_len - | |
866 | mptcp_subflow_get_map_offset(subflow); | |
867 | } | |
868 | ||
869 | static bool validate_mapping(struct sock *ssk, struct sk_buff *skb) | |
870 | { | |
871 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
872 | u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
873 | ||
874 | if (unlikely(before(ssn, subflow->map_subflow_seq))) { | |
875 | /* Mapping covers data later in the subflow stream, | |
876 | * currently unsupported. | |
877 | */ | |
61e71022 | 878 | dbg_bad_map(subflow, ssn); |
648ef4b8 MM |
879 | return false; |
880 | } | |
881 | if (unlikely(!before(ssn, subflow->map_subflow_seq + | |
882 | subflow->map_data_len))) { | |
883 | /* Mapping does covers past subflow data, invalid */ | |
61e71022 | 884 | dbg_bad_map(subflow, ssn); |
648ef4b8 MM |
885 | return false; |
886 | } | |
887 | return true; | |
888 | } | |
889 | ||
dd8bcd17 PA |
890 | static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *skb, |
891 | bool csum_reqd) | |
892 | { | |
893 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
dd8bcd17 | 894 | u32 offset, seq, delta; |
ba2c89e0 | 895 | __sum16 csum; |
dd8bcd17 PA |
896 | int len; |
897 | ||
898 | if (!csum_reqd) | |
899 | return MAPPING_OK; | |
900 | ||
901 | /* mapping already validated on previous traversal */ | |
902 | if (subflow->map_csum_len == subflow->map_data_len) | |
903 | return MAPPING_OK; | |
904 | ||
905 | /* traverse the receive queue, ensuring it contains a full | |
906 | * DSS mapping and accumulating the related csum. | |
907 | * Preserve the accoumlate csum across multiple calls, to compute | |
908 | * the csum only once | |
909 | */ | |
910 | delta = subflow->map_data_len - subflow->map_csum_len; | |
911 | for (;;) { | |
912 | seq = tcp_sk(ssk)->copied_seq + subflow->map_csum_len; | |
913 | offset = seq - TCP_SKB_CB(skb)->seq; | |
914 | ||
915 | /* if the current skb has not been accounted yet, csum its contents | |
916 | * up to the amount covered by the current DSS | |
917 | */ | |
918 | if (offset < skb->len) { | |
919 | __wsum csum; | |
920 | ||
921 | len = min(skb->len - offset, delta); | |
922 | csum = skb_checksum(skb, offset, len, 0); | |
923 | subflow->map_data_csum = csum_block_add(subflow->map_data_csum, csum, | |
924 | subflow->map_csum_len); | |
925 | ||
926 | delta -= len; | |
927 | subflow->map_csum_len += len; | |
928 | } | |
929 | if (delta == 0) | |
930 | break; | |
931 | ||
932 | if (skb_queue_is_last(&ssk->sk_receive_queue, skb)) { | |
933 | /* if this subflow is closed, the partial mapping | |
934 | * will be never completed; flush the pending skbs, so | |
935 | * that subflow_sched_work_if_closed() can kick in | |
936 | */ | |
937 | if (unlikely(ssk->sk_state == TCP_CLOSE)) | |
938 | while ((skb = skb_peek(&ssk->sk_receive_queue))) | |
939 | sk_eat_skb(ssk, skb); | |
940 | ||
941 | /* not enough data to validate the csum */ | |
942 | return MAPPING_EMPTY; | |
943 | } | |
944 | ||
945 | /* the DSS mapping for next skbs will be validated later, | |
946 | * when a get_mapping_status call will process such skb | |
947 | */ | |
948 | skb = skb->next; | |
949 | } | |
950 | ||
951 | /* note that 'map_data_len' accounts only for the carried data, does | |
952 | * not include the eventual seq increment due to the data fin, | |
953 | * while the pseudo header requires the original DSS data len, | |
954 | * including that | |
955 | */ | |
8401e87f GT |
956 | csum = __mptcp_make_csum(subflow->map_seq, |
957 | subflow->map_subflow_seq, | |
958 | subflow->map_data_len + subflow->map_data_fin, | |
959 | subflow->map_data_csum); | |
960 | if (unlikely(csum)) { | |
fe3ab1cb | 961 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR); |
31bf11de | 962 | return MAPPING_BAD_CSUM; |
fe3ab1cb | 963 | } |
dd8bcd17 | 964 | |
ae66fb2b | 965 | subflow->valid_csum_seen = 1; |
dd8bcd17 PA |
966 | return MAPPING_OK; |
967 | } | |
968 | ||
43b54c6e MM |
969 | static enum mapping_status get_mapping_status(struct sock *ssk, |
970 | struct mptcp_sock *msk) | |
648ef4b8 MM |
971 | { |
972 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
dd8bcd17 | 973 | bool csum_reqd = READ_ONCE(msk->csum_enabled); |
648ef4b8 MM |
974 | struct mptcp_ext *mpext; |
975 | struct sk_buff *skb; | |
976 | u16 data_len; | |
977 | u64 map_seq; | |
978 | ||
979 | skb = skb_peek(&ssk->sk_receive_queue); | |
980 | if (!skb) | |
981 | return MAPPING_EMPTY; | |
982 | ||
e1ff9e82 DC |
983 | if (mptcp_check_fallback(ssk)) |
984 | return MAPPING_DUMMY; | |
985 | ||
648ef4b8 MM |
986 | mpext = mptcp_get_ext(skb); |
987 | if (!mpext || !mpext->use_map) { | |
988 | if (!subflow->map_valid && !skb->len) { | |
989 | /* the TCP stack deliver 0 len FIN pkt to the receive | |
990 | * queue, that is the only 0len pkts ever expected here, | |
991 | * and we can admit no mapping only for 0 len pkts | |
992 | */ | |
993 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) | |
994 | WARN_ONCE(1, "0len seq %d:%d flags %x", | |
995 | TCP_SKB_CB(skb)->seq, | |
996 | TCP_SKB_CB(skb)->end_seq, | |
997 | TCP_SKB_CB(skb)->tcp_flags); | |
998 | sk_eat_skb(ssk, skb); | |
999 | return MAPPING_EMPTY; | |
1000 | } | |
1001 | ||
1002 | if (!subflow->map_valid) | |
1003 | return MAPPING_INVALID; | |
1004 | ||
1005 | goto validate_seq; | |
1006 | } | |
1007 | ||
0918e34b | 1008 | trace_get_mapping_status(mpext); |
648ef4b8 MM |
1009 | |
1010 | data_len = mpext->data_len; | |
1011 | if (data_len == 0) { | |
f8d4bcac | 1012 | pr_debug("infinite mapping received"); |
fc518953 | 1013 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); |
f8d4bcac | 1014 | subflow->map_data_len = 0; |
648ef4b8 MM |
1015 | return MAPPING_INVALID; |
1016 | } | |
1017 | ||
1018 | if (mpext->data_fin == 1) { | |
1019 | if (data_len == 1) { | |
1a49b2c2 MM |
1020 | bool updated = mptcp_update_rcv_data_fin(msk, mpext->data_seq, |
1021 | mpext->dsn64); | |
43b54c6e | 1022 | pr_debug("DATA_FIN with no payload seq=%llu", mpext->data_seq); |
648ef4b8 MM |
1023 | if (subflow->map_valid) { |
1024 | /* A DATA_FIN might arrive in a DSS | |
1025 | * option before the previous mapping | |
1026 | * has been fully consumed. Continue | |
1027 | * handling the existing mapping. | |
1028 | */ | |
1029 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
1030 | return MAPPING_OK; | |
1031 | } else { | |
ef59b195 MM |
1032 | if (updated && schedule_work(&msk->work)) |
1033 | sock_hold((struct sock *)msk); | |
1034 | ||
648ef4b8 MM |
1035 | return MAPPING_DATA_FIN; |
1036 | } | |
43b54c6e | 1037 | } else { |
017512a0 | 1038 | u64 data_fin_seq = mpext->data_seq + data_len - 1; |
1a49b2c2 MM |
1039 | |
1040 | /* If mpext->data_seq is a 32-bit value, data_fin_seq | |
1041 | * must also be limited to 32 bits. | |
1042 | */ | |
1043 | if (!mpext->dsn64) | |
1044 | data_fin_seq &= GENMASK_ULL(31, 0); | |
1045 | ||
1046 | mptcp_update_rcv_data_fin(msk, data_fin_seq, mpext->dsn64); | |
1047 | pr_debug("DATA_FIN with mapping seq=%llu dsn64=%d", | |
1048 | data_fin_seq, mpext->dsn64); | |
648ef4b8 MM |
1049 | } |
1050 | ||
1051 | /* Adjust for DATA_FIN using 1 byte of sequence space */ | |
1052 | data_len--; | |
1053 | } | |
1054 | ||
5957a890 | 1055 | map_seq = mptcp_expand_seq(READ_ONCE(msk->ack_seq), mpext->data_seq, mpext->dsn64); |
37198e93 | 1056 | WRITE_ONCE(mptcp_sk(subflow->conn)->use_64bit_ack, !!mpext->dsn64); |
648ef4b8 MM |
1057 | |
1058 | if (subflow->map_valid) { | |
1059 | /* Allow replacing only with an identical map */ | |
1060 | if (subflow->map_seq == map_seq && | |
1061 | subflow->map_subflow_seq == mpext->subflow_seq && | |
dd8bcd17 PA |
1062 | subflow->map_data_len == data_len && |
1063 | subflow->map_csum_reqd == mpext->csum_reqd) { | |
648ef4b8 | 1064 | skb_ext_del(skb, SKB_EXT_MPTCP); |
dd8bcd17 | 1065 | goto validate_csum; |
648ef4b8 MM |
1066 | } |
1067 | ||
1068 | /* If this skb data are fully covered by the current mapping, | |
1069 | * the new map would need caching, which is not supported | |
1070 | */ | |
fc518953 FW |
1071 | if (skb_is_fully_mapped(ssk, skb)) { |
1072 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH); | |
648ef4b8 | 1073 | return MAPPING_INVALID; |
fc518953 | 1074 | } |
648ef4b8 MM |
1075 | |
1076 | /* will validate the next map after consuming the current one */ | |
dd8bcd17 | 1077 | goto validate_csum; |
648ef4b8 MM |
1078 | } |
1079 | ||
1080 | subflow->map_seq = map_seq; | |
1081 | subflow->map_subflow_seq = mpext->subflow_seq; | |
1082 | subflow->map_data_len = data_len; | |
1083 | subflow->map_valid = 1; | |
dd8bcd17 | 1084 | subflow->map_data_fin = mpext->data_fin; |
d22f4988 | 1085 | subflow->mpc_map = mpext->mpc_map; |
dd8bcd17 PA |
1086 | subflow->map_csum_reqd = mpext->csum_reqd; |
1087 | subflow->map_csum_len = 0; | |
1088 | subflow->map_data_csum = csum_unfold(mpext->csum); | |
1089 | ||
1090 | /* Cfr RFC 8684 Section 3.3.0 */ | |
1091 | if (unlikely(subflow->map_csum_reqd != csum_reqd)) | |
1092 | return MAPPING_INVALID; | |
1093 | ||
1094 | pr_debug("new map seq=%llu subflow_seq=%u data_len=%u csum=%d:%u", | |
648ef4b8 | 1095 | subflow->map_seq, subflow->map_subflow_seq, |
dd8bcd17 PA |
1096 | subflow->map_data_len, subflow->map_csum_reqd, |
1097 | subflow->map_data_csum); | |
648ef4b8 MM |
1098 | |
1099 | validate_seq: | |
1100 | /* we revalidate valid mapping on new skb, because we must ensure | |
1101 | * the current skb is completely covered by the available mapping | |
1102 | */ | |
06285da9 PA |
1103 | if (!validate_mapping(ssk, skb)) { |
1104 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSTCPMISMATCH); | |
648ef4b8 | 1105 | return MAPPING_INVALID; |
06285da9 | 1106 | } |
648ef4b8 MM |
1107 | |
1108 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
dd8bcd17 PA |
1109 | |
1110 | validate_csum: | |
1111 | return validate_data_csum(ssk, skb, csum_reqd); | |
648ef4b8 MM |
1112 | } |
1113 | ||
04e4cd4f | 1114 | static void mptcp_subflow_discard_data(struct sock *ssk, struct sk_buff *skb, |
1d39cd8c | 1115 | u64 limit) |
6719331c PA |
1116 | { |
1117 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
04e4cd4f PA |
1118 | bool fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; |
1119 | u32 incr; | |
1120 | ||
1121 | incr = limit >= skb->len ? skb->len + fin : limit; | |
1122 | ||
1123 | pr_debug("discarding=%d len=%d seq=%d", incr, skb->len, | |
1124 | subflow->map_subflow_seq); | |
06242e44 | 1125 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DUPDATA); |
04e4cd4f PA |
1126 | tcp_sk(ssk)->copied_seq += incr; |
1127 | if (!before(tcp_sk(ssk)->copied_seq, TCP_SKB_CB(skb)->end_seq)) | |
1128 | sk_eat_skb(ssk, skb); | |
1129 | if (mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) | |
1130 | subflow->map_valid = 0; | |
6719331c PA |
1131 | } |
1132 | ||
40947e13 FW |
1133 | /* sched mptcp worker to remove the subflow if no more data is pending */ |
1134 | static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ssk) | |
1135 | { | |
1136 | struct sock *sk = (struct sock *)msk; | |
1137 | ||
1138 | if (likely(ssk->sk_state != TCP_CLOSE)) | |
1139 | return; | |
1140 | ||
1141 | if (skb_queue_empty(&ssk->sk_receive_queue) && | |
1142 | !test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) { | |
1143 | sock_hold(sk); | |
1144 | if (!schedule_work(&msk->work)) | |
1145 | sock_put(sk); | |
1146 | } | |
1147 | } | |
1148 | ||
ae66fb2b MM |
1149 | static bool subflow_can_fallback(struct mptcp_subflow_context *subflow) |
1150 | { | |
1151 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
1152 | ||
1153 | if (subflow->mp_join) | |
1154 | return false; | |
1155 | else if (READ_ONCE(msk->csum_enabled)) | |
1156 | return !subflow->valid_csum_seen; | |
1157 | else | |
1158 | return !subflow->fully_established; | |
1159 | } | |
1160 | ||
76a13b31 GT |
1161 | static void mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk) |
1162 | { | |
1163 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1164 | unsigned long fail_tout; | |
1165 | ||
1166 | /* greceful failure can happen only on the MPC subflow */ | |
1167 | if (WARN_ON_ONCE(ssk != READ_ONCE(msk->first))) | |
1168 | return; | |
1169 | ||
1170 | /* since the close timeout take precedence on the fail one, | |
1171 | * no need to start the latter when the first is already set | |
1172 | */ | |
1173 | if (sock_flag((struct sock *)msk, SOCK_DEAD)) | |
1174 | return; | |
1175 | ||
1176 | /* we don't need extreme accuracy here, use a zero fail_tout as special | |
1177 | * value meaning no fail timeout at all; | |
1178 | */ | |
1179 | fail_tout = jiffies + TCP_RTO_MAX; | |
1180 | if (!fail_tout) | |
1181 | fail_tout = 1; | |
1182 | WRITE_ONCE(subflow->fail_tout, fail_tout); | |
1183 | tcp_send_ack(ssk); | |
1184 | ||
1185 | mptcp_reset_timeout(msk, subflow->fail_tout); | |
1186 | } | |
1187 | ||
648ef4b8 MM |
1188 | static bool subflow_check_data_avail(struct sock *ssk) |
1189 | { | |
1190 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1191 | enum mapping_status status; | |
1192 | struct mptcp_sock *msk; | |
1193 | struct sk_buff *skb; | |
1194 | ||
47bebdf3 | 1195 | if (!skb_peek(&ssk->sk_receive_queue)) |
ea56dcb4 | 1196 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); |
648ef4b8 MM |
1197 | if (subflow->data_avail) |
1198 | return true; | |
1199 | ||
648ef4b8 MM |
1200 | msk = mptcp_sk(subflow->conn); |
1201 | for (;;) { | |
648ef4b8 MM |
1202 | u64 ack_seq; |
1203 | u64 old_ack; | |
1204 | ||
43b54c6e | 1205 | status = get_mapping_status(ssk, msk); |
d96a838a | 1206 | trace_subflow_check_data_avail(status, skb_peek(&ssk->sk_receive_queue)); |
31bf11de PA |
1207 | if (unlikely(status == MAPPING_INVALID || status == MAPPING_DUMMY || |
1208 | status == MAPPING_BAD_CSUM)) | |
dea2b1ea | 1209 | goto fallback; |
648ef4b8 MM |
1210 | |
1211 | if (status != MAPPING_OK) | |
40947e13 | 1212 | goto no_data; |
648ef4b8 MM |
1213 | |
1214 | skb = skb_peek(&ssk->sk_receive_queue); | |
1215 | if (WARN_ON_ONCE(!skb)) | |
40947e13 | 1216 | goto no_data; |
648ef4b8 | 1217 | |
d22f4988 CP |
1218 | /* if msk lacks the remote key, this subflow must provide an |
1219 | * MP_CAPABLE-based mapping | |
1220 | */ | |
1221 | if (unlikely(!READ_ONCE(msk->can_ack))) { | |
dea2b1ea PA |
1222 | if (!subflow->mpc_map) |
1223 | goto fallback; | |
d22f4988 CP |
1224 | WRITE_ONCE(msk->remote_key, subflow->remote_key); |
1225 | WRITE_ONCE(msk->ack_seq, subflow->map_seq); | |
1226 | WRITE_ONCE(msk->can_ack, true); | |
1227 | } | |
1228 | ||
648ef4b8 MM |
1229 | old_ack = READ_ONCE(msk->ack_seq); |
1230 | ack_seq = mptcp_subflow_get_mapped_dsn(subflow); | |
1231 | pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, | |
1232 | ack_seq); | |
99d1055c PA |
1233 | if (unlikely(before64(ack_seq, old_ack))) { |
1234 | mptcp_subflow_discard_data(ssk, skb, old_ack - ack_seq); | |
1235 | continue; | |
47bebdf3 | 1236 | } |
648ef4b8 | 1237 | |
99d1055c PA |
1238 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); |
1239 | break; | |
648ef4b8 MM |
1240 | } |
1241 | return true; | |
1242 | ||
40947e13 FW |
1243 | no_data: |
1244 | subflow_sched_work_if_closed(msk, ssk); | |
1245 | return false; | |
dea2b1ea PA |
1246 | |
1247 | fallback: | |
0348c690 GT |
1248 | if (!__mptcp_check_fallback(msk)) { |
1249 | /* RFC 8684 section 3.7. */ | |
31bf11de PA |
1250 | if (status == MAPPING_BAD_CSUM && |
1251 | (subflow->mp_join || subflow->valid_csum_seen)) { | |
1252 | subflow->send_mp_fail = 1; | |
1253 | ||
7b16871f | 1254 | if (!READ_ONCE(msk->allow_infinite_fallback)) { |
0348c690 GT |
1255 | subflow->reset_transient = 0; |
1256 | subflow->reset_reason = MPTCP_RST_EMIDDLEBOX; | |
f745a3eb | 1257 | goto reset; |
0348c690 | 1258 | } |
f745a3eb PA |
1259 | mptcp_subflow_fail(msk, ssk); |
1260 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); | |
0348c690 GT |
1261 | return true; |
1262 | } | |
1263 | ||
d7e6f583 | 1264 | if (!subflow_can_fallback(subflow) && subflow->map_data_len) { |
0348c690 GT |
1265 | /* fatal protocol error, close the socket. |
1266 | * subflow_error_report() will introduce the appropriate barriers | |
1267 | */ | |
1761fed2 | 1268 | subflow->reset_transient = 0; |
0348c690 | 1269 | subflow->reset_reason = MPTCP_RST_EMPTCP; |
f745a3eb PA |
1270 | |
1271 | reset: | |
1272 | ssk->sk_err = EBADMSG; | |
1273 | tcp_set_state(ssk, TCP_CLOSE); | |
1274 | while ((skb = skb_peek(&ssk->sk_receive_queue))) | |
1275 | sk_eat_skb(ssk, skb); | |
1761fed2 | 1276 | tcp_send_active_reset(ssk, GFP_ATOMIC); |
0348c690 GT |
1277 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); |
1278 | return false; | |
478d7700 | 1279 | } |
478d7700 | 1280 | |
d51991e2 | 1281 | mptcp_do_fallback(ssk); |
dea2b1ea PA |
1282 | } |
1283 | ||
dea2b1ea PA |
1284 | skb = skb_peek(&ssk->sk_receive_queue); |
1285 | subflow->map_valid = 1; | |
1286 | subflow->map_seq = READ_ONCE(msk->ack_seq); | |
1287 | subflow->map_data_len = skb->len; | |
1288 | subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
99d1055c | 1289 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); |
dea2b1ea | 1290 | return true; |
648ef4b8 MM |
1291 | } |
1292 | ||
1293 | bool mptcp_subflow_data_available(struct sock *sk) | |
1294 | { | |
1295 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
648ef4b8 MM |
1296 | |
1297 | /* check if current mapping is still valid */ | |
1298 | if (subflow->map_valid && | |
1299 | mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) { | |
1300 | subflow->map_valid = 0; | |
ea56dcb4 | 1301 | WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); |
648ef4b8 MM |
1302 | |
1303 | pr_debug("Done with mapping: seq=%u data_len=%u", | |
1304 | subflow->map_subflow_seq, | |
1305 | subflow->map_data_len); | |
1306 | } | |
1307 | ||
47bebdf3 | 1308 | return subflow_check_data_avail(sk); |
648ef4b8 MM |
1309 | } |
1310 | ||
071c8ed6 FW |
1311 | /* If ssk has an mptcp parent socket, use the mptcp rcvbuf occupancy, |
1312 | * not the ssk one. | |
1313 | * | |
1314 | * In mptcp, rwin is about the mptcp-level connection data. | |
1315 | * | |
1316 | * Data that is still on the ssk rx queue can thus be ignored, | |
55320b82 | 1317 | * as far as mptcp peer is concerned that data is still inflight. |
071c8ed6 FW |
1318 | * DSS ACK is updated when skb is moved to the mptcp rx queue. |
1319 | */ | |
1320 | void mptcp_space(const struct sock *ssk, int *space, int *full_space) | |
1321 | { | |
1322 | const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1323 | const struct sock *sk = subflow->conn; | |
1324 | ||
ea4ca586 | 1325 | *space = __mptcp_space(sk); |
071c8ed6 FW |
1326 | *full_space = tcp_full_space(sk); |
1327 | } | |
1328 | ||
15cc1045 PA |
1329 | void __mptcp_error_report(struct sock *sk) |
1330 | { | |
1331 | struct mptcp_subflow_context *subflow; | |
1332 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1333 | ||
1334 | mptcp_for_each_subflow(msk, subflow) { | |
1335 | struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | |
1336 | int err = sock_error(ssk); | |
1337 | ||
1338 | if (!err) | |
1339 | continue; | |
1340 | ||
1341 | /* only propagate errors on fallen-back sockets or | |
1342 | * on MPC connect | |
1343 | */ | |
1344 | if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(msk)) | |
1345 | continue; | |
1346 | ||
1347 | inet_sk_state_store(sk, inet_sk_state_load(ssk)); | |
1348 | sk->sk_err = -err; | |
1349 | ||
1350 | /* This barrier is coupled with smp_rmb() in mptcp_poll() */ | |
1351 | smp_wmb(); | |
e3ae2365 | 1352 | sk_error_report(sk); |
15cc1045 PA |
1353 | break; |
1354 | } | |
1355 | } | |
1356 | ||
1357 | static void subflow_error_report(struct sock *ssk) | |
1358 | { | |
1359 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1360 | ||
1361 | mptcp_data_lock(sk); | |
1362 | if (!sock_owned_by_user(sk)) | |
1363 | __mptcp_error_report(sk); | |
1364 | else | |
e9d09bac | 1365 | __set_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->cb_flags); |
15cc1045 PA |
1366 | mptcp_data_unlock(sk); |
1367 | } | |
1368 | ||
499ada50 PA |
1369 | static void subflow_data_ready(struct sock *sk) |
1370 | { | |
1371 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
1372 | u16 state = 1 << inet_sk_state_load(sk); | |
1373 | struct sock *parent = subflow->conn; | |
1374 | struct mptcp_sock *msk; | |
1375 | ||
1376 | msk = mptcp_sk(parent); | |
1377 | if (state & TCPF_LISTEN) { | |
1378 | /* MPJ subflow are removed from accept queue before reaching here, | |
1379 | * avoid stray wakeups | |
1380 | */ | |
1381 | if (reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue)) | |
1382 | return; | |
1383 | ||
499ada50 PA |
1384 | parent->sk_data_ready(parent); |
1385 | return; | |
1386 | } | |
1387 | ||
1388 | WARN_ON_ONCE(!__mptcp_check_fallback(msk) && !subflow->mp_capable && | |
1389 | !subflow->mp_join && !(state & TCPF_CLOSE)); | |
1390 | ||
1391 | if (mptcp_subflow_data_available(sk)) | |
1392 | mptcp_data_ready(parent, sk); | |
1393 | else if (unlikely(sk->sk_err)) | |
1394 | subflow_error_report(sk); | |
1395 | } | |
1396 | ||
1397 | static void subflow_write_space(struct sock *ssk) | |
1398 | { | |
1399 | struct sock *sk = mptcp_subflow_ctx(ssk)->conn; | |
1400 | ||
1401 | mptcp_propagate_sndbuf(sk, ssk); | |
1402 | mptcp_write_space(sk); | |
1403 | } | |
1404 | ||
51fa7f8e | 1405 | static const struct inet_connection_sock_af_ops * |
cec37a6e PK |
1406 | subflow_default_af_ops(struct sock *sk) |
1407 | { | |
1408 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1409 | if (sk->sk_family == AF_INET6) | |
1410 | return &subflow_v6_specific; | |
1411 | #endif | |
1412 | return &subflow_specific; | |
1413 | } | |
1414 | ||
cec37a6e | 1415 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
31484d56 GU |
1416 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped) |
1417 | { | |
cec37a6e PK |
1418 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
1419 | struct inet_connection_sock *icsk = inet_csk(sk); | |
51fa7f8e | 1420 | const struct inet_connection_sock_af_ops *target; |
cec37a6e PK |
1421 | |
1422 | target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk); | |
1423 | ||
1424 | pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d", | |
edc7e489 | 1425 | subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped); |
cec37a6e PK |
1426 | |
1427 | if (likely(icsk->icsk_af_ops == target)) | |
1428 | return; | |
1429 | ||
1430 | subflow->icsk_af_ops = icsk->icsk_af_ops; | |
1431 | icsk->icsk_af_ops = target; | |
cec37a6e | 1432 | } |
31484d56 | 1433 | #endif |
cec37a6e | 1434 | |
1729cf18 GT |
1435 | void mptcp_info2sockaddr(const struct mptcp_addr_info *info, |
1436 | struct sockaddr_storage *addr, | |
1437 | unsigned short family) | |
ec3edaa7 PK |
1438 | { |
1439 | memset(addr, 0, sizeof(*addr)); | |
50a13bc3 | 1440 | addr->ss_family = family; |
ec3edaa7 PK |
1441 | if (addr->ss_family == AF_INET) { |
1442 | struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; | |
1443 | ||
50a13bc3 MB |
1444 | if (info->family == AF_INET) |
1445 | in_addr->sin_addr = info->addr; | |
1446 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1447 | else if (ipv6_addr_v4mapped(&info->addr6)) | |
1448 | in_addr->sin_addr.s_addr = info->addr6.s6_addr32[3]; | |
1449 | #endif | |
ec3edaa7 PK |
1450 | in_addr->sin_port = info->port; |
1451 | } | |
1452 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1453 | else if (addr->ss_family == AF_INET6) { | |
1454 | struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; | |
1455 | ||
50a13bc3 MB |
1456 | if (info->family == AF_INET) |
1457 | ipv6_addr_set_v4mapped(info->addr.s_addr, | |
1458 | &in6_addr->sin6_addr); | |
1459 | else | |
1460 | in6_addr->sin6_addr = info->addr6; | |
ec3edaa7 PK |
1461 | in6_addr->sin6_port = info->port; |
1462 | } | |
1463 | #endif | |
1464 | } | |
1465 | ||
ef0da3b8 | 1466 | int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, |
ee285257 | 1467 | const struct mptcp_addr_info *remote) |
ec3edaa7 PK |
1468 | { |
1469 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1470 | struct mptcp_subflow_context *subflow; | |
1471 | struct sockaddr_storage addr; | |
2ff0e566 | 1472 | int remote_id = remote->id; |
6bad912b | 1473 | int local_id = loc->id; |
95d68651 | 1474 | int err = -ENOTCONN; |
ec3edaa7 | 1475 | struct socket *sf; |
6bad912b | 1476 | struct sock *ssk; |
ec3edaa7 PK |
1477 | u32 remote_token; |
1478 | int addrlen; | |
ee285257 GT |
1479 | int ifindex; |
1480 | u8 flags; | |
ec3edaa7 | 1481 | |
b93df08c | 1482 | if (!mptcp_is_fully_established(sk)) |
95d68651 | 1483 | goto err_out; |
ec3edaa7 PK |
1484 | |
1485 | err = mptcp_subflow_create_socket(sk, &sf); | |
1486 | if (err) | |
95d68651 | 1487 | goto err_out; |
ec3edaa7 | 1488 | |
6bad912b PA |
1489 | ssk = sf->sk; |
1490 | subflow = mptcp_subflow_ctx(ssk); | |
1491 | do { | |
1492 | get_random_bytes(&subflow->local_nonce, sizeof(u32)); | |
1493 | } while (!subflow->local_nonce); | |
1494 | ||
4cf86ae8 PA |
1495 | if (local_id) |
1496 | subflow_set_local_id(subflow, local_id); | |
6bad912b | 1497 | |
8b201370 | 1498 | mptcp_pm_get_flags_and_ifindex_by_id(msk, local_id, |
ee285257 | 1499 | &flags, &ifindex); |
ec3edaa7 PK |
1500 | subflow->remote_key = msk->remote_key; |
1501 | subflow->local_key = msk->local_key; | |
1502 | subflow->token = msk->token; | |
50a13bc3 | 1503 | mptcp_info2sockaddr(loc, &addr, ssk->sk_family); |
ec3edaa7 PK |
1504 | |
1505 | addrlen = sizeof(struct sockaddr_in); | |
1506 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
50a13bc3 | 1507 | if (addr.ss_family == AF_INET6) |
ec3edaa7 PK |
1508 | addrlen = sizeof(struct sockaddr_in6); |
1509 | #endif | |
c9406a23 FW |
1510 | mptcp_sockopt_sync(msk, ssk); |
1511 | ||
daa83ab0 | 1512 | ssk->sk_bound_dev_if = ifindex; |
ec3edaa7 PK |
1513 | err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); |
1514 | if (err) | |
1515 | goto failed; | |
1516 | ||
1517 | mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); | |
2ff0e566 GT |
1518 | pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk, |
1519 | remote_token, local_id, remote_id); | |
ec3edaa7 | 1520 | subflow->remote_token = remote_token; |
2ff0e566 | 1521 | subflow->remote_id = remote_id; |
ec3edaa7 | 1522 | subflow->request_join = 1; |
daa83ab0 | 1523 | subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP); |
50a13bc3 | 1524 | mptcp_info2sockaddr(remote, &addr, ssk->sk_family); |
ec3edaa7 | 1525 | |
3e501490 PA |
1526 | sock_hold(ssk); |
1527 | list_add_tail(&subflow->node, &msk->conn_list); | |
ec3edaa7 PK |
1528 | err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); |
1529 | if (err && err != -EINPROGRESS) | |
5b950ff4 | 1530 | goto failed_unlink; |
ec3edaa7 | 1531 | |
866f26f2 PA |
1532 | /* discard the subflow socket */ |
1533 | mptcp_sock_graft(ssk, sk->sk_socket); | |
1534 | iput(SOCK_INODE(sf)); | |
0530020a | 1535 | WRITE_ONCE(msk->allow_infinite_fallback, false); |
ec3edaa7 PK |
1536 | return err; |
1537 | ||
5b950ff4 | 1538 | failed_unlink: |
5b950ff4 | 1539 | list_del(&subflow->node); |
f0715779 | 1540 | sock_put(mptcp_subflow_tcp_sock(subflow)); |
ec3edaa7 | 1541 | |
ec3edaa7 | 1542 | failed: |
e16163b6 | 1543 | subflow->disposable = 1; |
ec3edaa7 | 1544 | sock_release(sf); |
95d68651 PA |
1545 | |
1546 | err_out: | |
1547 | /* we account subflows before the creation, and this failures will not | |
1548 | * be caught by sk_state_change() | |
1549 | */ | |
1550 | mptcp_pm_close_subflow(msk); | |
ec3edaa7 PK |
1551 | return err; |
1552 | } | |
1553 | ||
3764b0c5 NR |
1554 | static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) |
1555 | { | |
1556 | #ifdef CONFIG_SOCK_CGROUP_DATA | |
1557 | struct sock_cgroup_data *parent_skcd = &parent->sk_cgrp_data, | |
1558 | *child_skcd = &child->sk_cgrp_data; | |
1559 | ||
1560 | /* only the additional subflows created by kworkers have to be modified */ | |
1561 | if (cgroup_id(sock_cgroup_ptr(parent_skcd)) != | |
1562 | cgroup_id(sock_cgroup_ptr(child_skcd))) { | |
1563 | #ifdef CONFIG_MEMCG | |
1564 | struct mem_cgroup *memcg = parent->sk_memcg; | |
1565 | ||
1566 | mem_cgroup_sk_free(child); | |
1567 | if (memcg && css_tryget(&memcg->css)) | |
1568 | child->sk_memcg = memcg; | |
1569 | #endif /* CONFIG_MEMCG */ | |
1570 | ||
1571 | cgroup_sk_free(child_skcd); | |
1572 | *child_skcd = *parent_skcd; | |
1573 | cgroup_sk_clone(child_skcd); | |
1574 | } | |
1575 | #endif /* CONFIG_SOCK_CGROUP_DATA */ | |
1576 | } | |
1577 | ||
b19bc294 PA |
1578 | static void mptcp_subflow_ops_override(struct sock *ssk) |
1579 | { | |
1580 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1581 | if (ssk->sk_prot == &tcpv6_prot) | |
1582 | ssk->sk_prot = &tcpv6_prot_override; | |
1583 | else | |
1584 | #endif | |
1585 | ssk->sk_prot = &tcp_prot_override; | |
1586 | } | |
1587 | ||
1588 | static void mptcp_subflow_ops_undo_override(struct sock *ssk) | |
1589 | { | |
1590 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1591 | if (ssk->sk_prot == &tcpv6_prot_override) | |
1592 | ssk->sk_prot = &tcpv6_prot; | |
1593 | else | |
1594 | #endif | |
1595 | ssk->sk_prot = &tcp_prot; | |
1596 | } | |
2303f994 PK |
1597 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) |
1598 | { | |
1599 | struct mptcp_subflow_context *subflow; | |
1600 | struct net *net = sock_net(sk); | |
1601 | struct socket *sf; | |
1602 | int err; | |
1603 | ||
adf73410 PA |
1604 | /* un-accepted server sockets can reach here - on bad configuration |
1605 | * bail early to avoid greater trouble later | |
1606 | */ | |
1607 | if (unlikely(!sk->sk_socket)) | |
1608 | return -EINVAL; | |
1609 | ||
cec37a6e PK |
1610 | err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP, |
1611 | &sf); | |
2303f994 PK |
1612 | if (err) |
1613 | return err; | |
1614 | ||
1615 | lock_sock(sf->sk); | |
1616 | ||
3764b0c5 NR |
1617 | /* the newly created socket has to be in the same cgroup as its parent */ |
1618 | mptcp_attach_cgroup(sk, sf->sk); | |
1619 | ||
2303f994 PK |
1620 | /* kernel sockets do not by default acquire net ref, but TCP timer |
1621 | * needs it. | |
1622 | */ | |
1623 | sf->sk->sk_net_refcnt = 1; | |
1d2f3d3c | 1624 | get_net_track(net, &sf->sk->ns_tracker, GFP_KERNEL); |
d477eb90 | 1625 | sock_inuse_add(net, 1); |
2303f994 PK |
1626 | err = tcp_set_ulp(sf->sk, "mptcp"); |
1627 | release_sock(sf->sk); | |
1628 | ||
b8ad540d WY |
1629 | if (err) { |
1630 | sock_release(sf); | |
2303f994 | 1631 | return err; |
b8ad540d | 1632 | } |
2303f994 | 1633 | |
7d14b0d2 PA |
1634 | /* the newly created socket really belongs to the owning MPTCP master |
1635 | * socket, even if for additional subflows the allocation is performed | |
1636 | * by a kernel workqueue. Adjust inode references, so that the | |
1637 | * procfs/diag interaces really show this one belonging to the correct | |
1638 | * user. | |
1639 | */ | |
1640 | SOCK_INODE(sf)->i_ino = SOCK_INODE(sk->sk_socket)->i_ino; | |
1641 | SOCK_INODE(sf)->i_uid = SOCK_INODE(sk->sk_socket)->i_uid; | |
1642 | SOCK_INODE(sf)->i_gid = SOCK_INODE(sk->sk_socket)->i_gid; | |
1643 | ||
2303f994 PK |
1644 | subflow = mptcp_subflow_ctx(sf->sk); |
1645 | pr_debug("subflow=%p", subflow); | |
1646 | ||
1647 | *new_sock = sf; | |
79c0949e | 1648 | sock_hold(sk); |
2303f994 | 1649 | subflow->conn = sk; |
b19bc294 | 1650 | mptcp_subflow_ops_override(sf->sk); |
2303f994 PK |
1651 | |
1652 | return 0; | |
1653 | } | |
1654 | ||
1655 | static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, | |
1656 | gfp_t priority) | |
1657 | { | |
1658 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1659 | struct mptcp_subflow_context *ctx; | |
1660 | ||
1661 | ctx = kzalloc(sizeof(*ctx), priority); | |
1662 | if (!ctx) | |
1663 | return NULL; | |
1664 | ||
1665 | rcu_assign_pointer(icsk->icsk_ulp_data, ctx); | |
cec37a6e | 1666 | INIT_LIST_HEAD(&ctx->node); |
b19bc294 | 1667 | INIT_LIST_HEAD(&ctx->delegated_node); |
2303f994 PK |
1668 | |
1669 | pr_debug("subflow=%p", ctx); | |
1670 | ||
1671 | ctx->tcp_sock = sk; | |
1672 | ||
1673 | return ctx; | |
1674 | } | |
1675 | ||
648ef4b8 MM |
1676 | static void __subflow_state_change(struct sock *sk) |
1677 | { | |
1678 | struct socket_wq *wq; | |
1679 | ||
1680 | rcu_read_lock(); | |
1681 | wq = rcu_dereference(sk->sk_wq); | |
1682 | if (skwq_has_sleeper(wq)) | |
1683 | wake_up_interruptible_all(&wq->wait); | |
1684 | rcu_read_unlock(); | |
1685 | } | |
1686 | ||
1687 | static bool subflow_is_done(const struct sock *sk) | |
1688 | { | |
1689 | return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE; | |
1690 | } | |
1691 | ||
1692 | static void subflow_state_change(struct sock *sk) | |
1693 | { | |
1694 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
dc093db5 | 1695 | struct sock *parent = subflow->conn; |
648ef4b8 MM |
1696 | |
1697 | __subflow_state_change(sk); | |
1698 | ||
8fd73804 | 1699 | if (subflow_simultaneous_connect(sk)) { |
5cf92bba | 1700 | mptcp_propagate_sndbuf(parent, sk); |
8fd73804 | 1701 | mptcp_do_fallback(sk); |
a6b118fe | 1702 | mptcp_rcv_space_init(mptcp_sk(parent), sk); |
8fd73804 DC |
1703 | pr_fallback(mptcp_sk(parent)); |
1704 | subflow->conn_finished = 1; | |
490274b4 | 1705 | mptcp_set_connected(parent); |
8fd73804 DC |
1706 | } |
1707 | ||
648ef4b8 MM |
1708 | /* as recvmsg() does not acquire the subflow socket for ssk selection |
1709 | * a fin packet carrying a DSS can be unnoticed if we don't trigger | |
1710 | * the data available machinery here. | |
1711 | */ | |
e1ff9e82 | 1712 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 1713 | mptcp_data_ready(parent, sk); |
499ada50 PA |
1714 | else if (unlikely(sk->sk_err)) |
1715 | subflow_error_report(sk); | |
648ef4b8 | 1716 | |
40947e13 FW |
1717 | subflow_sched_work_if_closed(mptcp_sk(parent), sk); |
1718 | ||
067a0b3d | 1719 | if (__mptcp_check_fallback(mptcp_sk(parent)) && |
648ef4b8 MM |
1720 | !subflow->rx_eof && subflow_is_done(sk)) { |
1721 | subflow->rx_eof = 1; | |
59832e24 | 1722 | mptcp_subflow_eof(parent); |
648ef4b8 MM |
1723 | } |
1724 | } | |
1725 | ||
6aeed904 PA |
1726 | void mptcp_subflow_queue_clean(struct sock *listener_ssk) |
1727 | { | |
1728 | struct request_sock_queue *queue = &inet_csk(listener_ssk)->icsk_accept_queue; | |
1729 | struct mptcp_sock *msk, *next, *head = NULL; | |
1730 | struct request_sock *req; | |
1731 | ||
1732 | /* build a list of all unaccepted mptcp sockets */ | |
1733 | spin_lock_bh(&queue->rskq_lock); | |
1734 | for (req = queue->rskq_accept_head; req; req = req->dl_next) { | |
1735 | struct mptcp_subflow_context *subflow; | |
1736 | struct sock *ssk = req->sk; | |
1737 | struct mptcp_sock *msk; | |
1738 | ||
1739 | if (!sk_is_mptcp(ssk)) | |
1740 | continue; | |
1741 | ||
1742 | subflow = mptcp_subflow_ctx(ssk); | |
1743 | if (!subflow || !subflow->conn) | |
1744 | continue; | |
1745 | ||
1746 | /* skip if already in list */ | |
1747 | msk = mptcp_sk(subflow->conn); | |
1748 | if (msk->dl_next || msk == head) | |
1749 | continue; | |
1750 | ||
1751 | msk->dl_next = head; | |
1752 | head = msk; | |
1753 | } | |
1754 | spin_unlock_bh(&queue->rskq_lock); | |
1755 | if (!head) | |
1756 | return; | |
1757 | ||
1758 | /* can't acquire the msk socket lock under the subflow one, | |
1759 | * or will cause ABBA deadlock | |
1760 | */ | |
1761 | release_sock(listener_ssk); | |
1762 | ||
1763 | for (msk = head; msk; msk = next) { | |
1764 | struct sock *sk = (struct sock *)msk; | |
1765 | bool slow; | |
1766 | ||
1767 | slow = lock_sock_fast_nested(sk); | |
1768 | next = msk->dl_next; | |
1769 | msk->first = NULL; | |
1770 | msk->dl_next = NULL; | |
1771 | unlock_sock_fast(sk, slow); | |
1772 | } | |
1773 | ||
1774 | /* we are still under the listener msk socket lock */ | |
1775 | lock_sock_nested(listener_ssk, SINGLE_DEPTH_NESTING); | |
1776 | } | |
1777 | ||
2303f994 PK |
1778 | static int subflow_ulp_init(struct sock *sk) |
1779 | { | |
cec37a6e | 1780 | struct inet_connection_sock *icsk = inet_csk(sk); |
2303f994 PK |
1781 | struct mptcp_subflow_context *ctx; |
1782 | struct tcp_sock *tp = tcp_sk(sk); | |
1783 | int err = 0; | |
1784 | ||
1785 | /* disallow attaching ULP to a socket unless it has been | |
1786 | * created with sock_create_kern() | |
1787 | */ | |
1788 | if (!sk->sk_kern_sock) { | |
1789 | err = -EOPNOTSUPP; | |
1790 | goto out; | |
1791 | } | |
1792 | ||
1793 | ctx = subflow_create_ctx(sk, GFP_KERNEL); | |
1794 | if (!ctx) { | |
1795 | err = -ENOMEM; | |
1796 | goto out; | |
1797 | } | |
1798 | ||
1799 | pr_debug("subflow=%p, family=%d", ctx, sk->sk_family); | |
1800 | ||
1801 | tp->is_mptcp = 1; | |
cec37a6e PK |
1802 | ctx->icsk_af_ops = icsk->icsk_af_ops; |
1803 | icsk->icsk_af_ops = subflow_default_af_ops(sk); | |
648ef4b8 | 1804 | ctx->tcp_state_change = sk->sk_state_change; |
15cc1045 | 1805 | ctx->tcp_error_report = sk->sk_error_report; |
952382c6 FW |
1806 | |
1807 | WARN_ON_ONCE(sk->sk_data_ready != sock_def_readable); | |
1808 | WARN_ON_ONCE(sk->sk_write_space != sk_stream_write_space); | |
1809 | ||
648ef4b8 MM |
1810 | sk->sk_data_ready = subflow_data_ready; |
1811 | sk->sk_write_space = subflow_write_space; | |
1812 | sk->sk_state_change = subflow_state_change; | |
15cc1045 | 1813 | sk->sk_error_report = subflow_error_report; |
2303f994 PK |
1814 | out: |
1815 | return err; | |
1816 | } | |
1817 | ||
e16163b6 | 1818 | static void subflow_ulp_release(struct sock *ssk) |
2303f994 | 1819 | { |
e16163b6 PA |
1820 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); |
1821 | bool release = true; | |
1822 | struct sock *sk; | |
2303f994 PK |
1823 | |
1824 | if (!ctx) | |
1825 | return; | |
1826 | ||
e16163b6 PA |
1827 | sk = ctx->conn; |
1828 | if (sk) { | |
1829 | /* if the msk has been orphaned, keep the ctx | |
0597d0f8 PA |
1830 | * alive, will be freed by __mptcp_close_ssk(), |
1831 | * when the subflow is still unaccepted | |
e16163b6 | 1832 | */ |
0597d0f8 | 1833 | release = ctx->disposable || list_empty(&ctx->node); |
e16163b6 PA |
1834 | sock_put(sk); |
1835 | } | |
79c0949e | 1836 | |
b19bc294 | 1837 | mptcp_subflow_ops_undo_override(ssk); |
e16163b6 PA |
1838 | if (release) |
1839 | kfree_rcu(ctx, rcu); | |
2303f994 PK |
1840 | } |
1841 | ||
cec37a6e PK |
1842 | static void subflow_ulp_clone(const struct request_sock *req, |
1843 | struct sock *newsk, | |
1844 | const gfp_t priority) | |
1845 | { | |
1846 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
1847 | struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk); | |
1848 | struct mptcp_subflow_context *new_ctx; | |
1849 | ||
f296234c PK |
1850 | if (!tcp_rsk(req)->is_mptcp || |
1851 | (!subflow_req->mp_capable && !subflow_req->mp_join)) { | |
648ef4b8 | 1852 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1853 | return; |
1854 | } | |
1855 | ||
1856 | new_ctx = subflow_create_ctx(newsk, priority); | |
edc7e489 | 1857 | if (!new_ctx) { |
648ef4b8 | 1858 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1859 | return; |
1860 | } | |
1861 | ||
1862 | new_ctx->conn_finished = 1; | |
1863 | new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; | |
648ef4b8 | 1864 | new_ctx->tcp_state_change = old_ctx->tcp_state_change; |
15cc1045 | 1865 | new_ctx->tcp_error_report = old_ctx->tcp_error_report; |
58b09919 PA |
1866 | new_ctx->rel_write_seq = 1; |
1867 | new_ctx->tcp_sock = newsk; | |
1868 | ||
f296234c PK |
1869 | if (subflow_req->mp_capable) { |
1870 | /* see comments in subflow_syn_recv_sock(), MPTCP connection | |
1871 | * is fully established only after we receive the remote key | |
1872 | */ | |
1873 | new_ctx->mp_capable = 1; | |
f296234c PK |
1874 | new_ctx->local_key = subflow_req->local_key; |
1875 | new_ctx->token = subflow_req->token; | |
1876 | new_ctx->ssn_offset = subflow_req->ssn_offset; | |
1877 | new_ctx->idsn = subflow_req->idsn; | |
4cf86ae8 PA |
1878 | |
1879 | /* this is the first subflow, id is always 0 */ | |
1880 | new_ctx->local_id_valid = 1; | |
f296234c | 1881 | } else if (subflow_req->mp_join) { |
ec3edaa7 | 1882 | new_ctx->ssn_offset = subflow_req->ssn_offset; |
f296234c PK |
1883 | new_ctx->mp_join = 1; |
1884 | new_ctx->fully_established = 1; | |
1885 | new_ctx->backup = subflow_req->backup; | |
2ff0e566 | 1886 | new_ctx->remote_id = subflow_req->remote_id; |
f296234c PK |
1887 | new_ctx->token = subflow_req->token; |
1888 | new_ctx->thmac = subflow_req->thmac; | |
4cf86ae8 PA |
1889 | |
1890 | /* the subflow req id is valid, fetched via subflow_check_req() | |
1891 | * and subflow_token_join_request() | |
1892 | */ | |
1893 | subflow_set_local_id(new_ctx, subflow_req->local_id); | |
f296234c | 1894 | } |
cec37a6e PK |
1895 | } |
1896 | ||
b19bc294 PA |
1897 | static void tcp_release_cb_override(struct sock *ssk) |
1898 | { | |
1899 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
1900 | ||
1901 | if (mptcp_subflow_has_delegated_action(subflow)) | |
1902 | mptcp_subflow_process_delegated(ssk); | |
1903 | ||
1904 | tcp_release_cb(ssk); | |
1905 | } | |
1906 | ||
2303f994 PK |
1907 | static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { |
1908 | .name = "mptcp", | |
1909 | .owner = THIS_MODULE, | |
1910 | .init = subflow_ulp_init, | |
1911 | .release = subflow_ulp_release, | |
cec37a6e | 1912 | .clone = subflow_ulp_clone, |
2303f994 PK |
1913 | }; |
1914 | ||
cec37a6e PK |
1915 | static int subflow_ops_init(struct request_sock_ops *subflow_ops) |
1916 | { | |
1917 | subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock); | |
1918 | subflow_ops->slab_name = "request_sock_subflow"; | |
1919 | ||
1920 | subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name, | |
1921 | subflow_ops->obj_size, 0, | |
1922 | SLAB_ACCOUNT | | |
1923 | SLAB_TYPESAFE_BY_RCU, | |
1924 | NULL); | |
1925 | if (!subflow_ops->slab) | |
1926 | return -ENOMEM; | |
1927 | ||
79c0949e PK |
1928 | subflow_ops->destructor = subflow_req_destructor; |
1929 | ||
cec37a6e PK |
1930 | return 0; |
1931 | } | |
1932 | ||
d39dceca | 1933 | void __init mptcp_subflow_init(void) |
2303f994 | 1934 | { |
08b8d080 FW |
1935 | mptcp_subflow_request_sock_ops = tcp_request_sock_ops; |
1936 | if (subflow_ops_init(&mptcp_subflow_request_sock_ops) != 0) | |
cec37a6e PK |
1937 | panic("MPTCP: failed to init subflow request sock ops\n"); |
1938 | ||
1939 | subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops; | |
7ea851d1 | 1940 | subflow_request_sock_ipv4_ops.route_req = subflow_v4_route_req; |
cec37a6e PK |
1941 | |
1942 | subflow_specific = ipv4_specific; | |
1943 | subflow_specific.conn_request = subflow_v4_conn_request; | |
1944 | subflow_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1945 | subflow_specific.sk_rx_dst_set = subflow_finish_connect; | |
4cf86ae8 | 1946 | subflow_specific.rebuild_header = subflow_rebuild_header; |
cec37a6e | 1947 | |
b19bc294 PA |
1948 | tcp_prot_override = tcp_prot; |
1949 | tcp_prot_override.release_cb = tcp_release_cb_override; | |
1950 | ||
cec37a6e PK |
1951 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
1952 | subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; | |
7ea851d1 | 1953 | subflow_request_sock_ipv6_ops.route_req = subflow_v6_route_req; |
cec37a6e PK |
1954 | |
1955 | subflow_v6_specific = ipv6_specific; | |
1956 | subflow_v6_specific.conn_request = subflow_v6_conn_request; | |
1957 | subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1958 | subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect; | |
4cf86ae8 | 1959 | subflow_v6_specific.rebuild_header = subflow_v6_rebuild_header; |
cec37a6e PK |
1960 | |
1961 | subflow_v6m_specific = subflow_v6_specific; | |
1962 | subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit; | |
1963 | subflow_v6m_specific.send_check = ipv4_specific.send_check; | |
1964 | subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; | |
1965 | subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; | |
1966 | subflow_v6m_specific.net_frag_header_len = 0; | |
4cf86ae8 | 1967 | subflow_v6m_specific.rebuild_header = subflow_rebuild_header; |
b19bc294 PA |
1968 | |
1969 | tcpv6_prot_override = tcpv6_prot; | |
1970 | tcpv6_prot_override.release_cb = tcp_release_cb_override; | |
cec37a6e PK |
1971 | #endif |
1972 | ||
5147dfb5 DC |
1973 | mptcp_diag_subflow_init(&subflow_ulp_ops); |
1974 | ||
2303f994 PK |
1975 | if (tcp_register_ulp(&subflow_ulp_ops) != 0) |
1976 | panic("MPTCP: failed to register subflows to ULP\n"); | |
1977 | } |