Commit | Line | Data |
---|---|---|
2303f994 PK |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Multipath TCP | |
3 | * | |
4 | * Copyright (c) 2017 - 2019, Intel Corporation. | |
5 | */ | |
6 | ||
79c0949e PK |
7 | #define pr_fmt(fmt) "MPTCP: " fmt |
8 | ||
2303f994 PK |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/netdevice.h> | |
f296234c | 12 | #include <crypto/algapi.h> |
bd697222 | 13 | #include <crypto/sha.h> |
2303f994 PK |
14 | #include <net/sock.h> |
15 | #include <net/inet_common.h> | |
16 | #include <net/inet_hashtables.h> | |
17 | #include <net/protocol.h> | |
18 | #include <net/tcp.h> | |
cec37a6e PK |
19 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
20 | #include <net/ip6_route.h> | |
21 | #endif | |
2303f994 PK |
22 | #include <net/mptcp.h> |
23 | #include "protocol.h" | |
fc518953 FW |
24 | #include "mib.h" |
25 | ||
26 | static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, | |
27 | enum linux_mptcp_mib_field field) | |
28 | { | |
29 | MPTCP_INC_STATS(sock_net(req_to_sk(req)), field); | |
30 | } | |
2303f994 | 31 | |
79c0949e PK |
32 | static void subflow_req_destructor(struct request_sock *req) |
33 | { | |
34 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
35 | ||
36 | pr_debug("subflow_req=%p", subflow_req); | |
37 | ||
8fd4de12 PA |
38 | if (subflow_req->msk) |
39 | sock_put((struct sock *)subflow_req->msk); | |
40 | ||
2c5ebd00 | 41 | mptcp_token_destroy_request(req); |
79c0949e PK |
42 | tcp_request_sock_ops.destructor(req); |
43 | } | |
44 | ||
f296234c PK |
45 | static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2, |
46 | void *hmac) | |
47 | { | |
48 | u8 msg[8]; | |
49 | ||
50 | put_unaligned_be32(nonce1, &msg[0]); | |
51 | put_unaligned_be32(nonce2, &msg[4]); | |
52 | ||
53 | mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac); | |
54 | } | |
55 | ||
56 | /* validate received token and create truncated hmac and nonce for SYN-ACK */ | |
8fd4de12 PA |
57 | static struct mptcp_sock *subflow_token_join_request(struct request_sock *req, |
58 | const struct sk_buff *skb) | |
f296234c PK |
59 | { |
60 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
bd697222 | 61 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c PK |
62 | struct mptcp_sock *msk; |
63 | int local_id; | |
64 | ||
65 | msk = mptcp_token_get_sock(subflow_req->token); | |
66 | if (!msk) { | |
fc518953 | 67 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINNOTOKEN); |
8fd4de12 | 68 | return NULL; |
f296234c PK |
69 | } |
70 | ||
71 | local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req); | |
72 | if (local_id < 0) { | |
73 | sock_put((struct sock *)msk); | |
8fd4de12 | 74 | return NULL; |
f296234c PK |
75 | } |
76 | subflow_req->local_id = local_id; | |
77 | ||
78 | get_random_bytes(&subflow_req->local_nonce, sizeof(u32)); | |
79 | ||
80 | subflow_generate_hmac(msk->local_key, msk->remote_key, | |
81 | subflow_req->local_nonce, | |
82 | subflow_req->remote_nonce, hmac); | |
83 | ||
84 | subflow_req->thmac = get_unaligned_be64(hmac); | |
8fd4de12 | 85 | return msk; |
f296234c PK |
86 | } |
87 | ||
cec37a6e PK |
88 | static void subflow_init_req(struct request_sock *req, |
89 | const struct sock *sk_listener, | |
90 | struct sk_buff *skb) | |
91 | { | |
92 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); | |
93 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
cfde141e | 94 | struct mptcp_options_received mp_opt; |
cec37a6e PK |
95 | |
96 | pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); | |
97 | ||
cfde141e | 98 | mptcp_get_options(skb, &mp_opt); |
cec37a6e PK |
99 | |
100 | subflow_req->mp_capable = 0; | |
f296234c | 101 | subflow_req->mp_join = 0; |
8fd4de12 | 102 | subflow_req->msk = NULL; |
2c5ebd00 | 103 | mptcp_token_init_request(req); |
cec37a6e PK |
104 | |
105 | #ifdef CONFIG_TCP_MD5SIG | |
106 | /* no MPTCP if MD5SIG is enabled on this socket or we may run out of | |
107 | * TCP option space. | |
108 | */ | |
109 | if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) | |
110 | return; | |
111 | #endif | |
112 | ||
cfde141e | 113 | if (mp_opt.mp_capable) { |
fc518953 FW |
114 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); |
115 | ||
cfde141e | 116 | if (mp_opt.mp_join) |
fc518953 | 117 | return; |
cfde141e | 118 | } else if (mp_opt.mp_join) { |
fc518953 FW |
119 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); |
120 | } | |
f296234c | 121 | |
cfde141e | 122 | if (mp_opt.mp_capable && listener->request_mptcp) { |
79c0949e PK |
123 | int err; |
124 | ||
125 | err = mptcp_token_new_request(req); | |
126 | if (err == 0) | |
127 | subflow_req->mp_capable = 1; | |
128 | ||
648ef4b8 | 129 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
cfde141e | 130 | } else if (mp_opt.mp_join && listener->request_mptcp) { |
ec3edaa7 | 131 | subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; |
f296234c | 132 | subflow_req->mp_join = 1; |
cfde141e PA |
133 | subflow_req->backup = mp_opt.backup; |
134 | subflow_req->remote_id = mp_opt.join_id; | |
135 | subflow_req->token = mp_opt.token; | |
136 | subflow_req->remote_nonce = mp_opt.nonce; | |
8fd4de12 PA |
137 | subflow_req->msk = subflow_token_join_request(req, skb); |
138 | pr_debug("token=%u, remote_nonce=%u msk=%p", subflow_req->token, | |
139 | subflow_req->remote_nonce, subflow_req->msk); | |
cec37a6e PK |
140 | } |
141 | } | |
142 | ||
143 | static void subflow_v4_init_req(struct request_sock *req, | |
144 | const struct sock *sk_listener, | |
145 | struct sk_buff *skb) | |
146 | { | |
147 | tcp_rsk(req)->is_mptcp = 1; | |
148 | ||
149 | tcp_request_sock_ipv4_ops.init_req(req, sk_listener, skb); | |
150 | ||
151 | subflow_init_req(req, sk_listener, skb); | |
152 | } | |
153 | ||
154 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
155 | static void subflow_v6_init_req(struct request_sock *req, | |
156 | const struct sock *sk_listener, | |
157 | struct sk_buff *skb) | |
158 | { | |
159 | tcp_rsk(req)->is_mptcp = 1; | |
160 | ||
161 | tcp_request_sock_ipv6_ops.init_req(req, sk_listener, skb); | |
162 | ||
163 | subflow_init_req(req, sk_listener, skb); | |
164 | } | |
165 | #endif | |
166 | ||
ec3edaa7 PK |
167 | /* validate received truncated hmac and create hmac for third ACK */ |
168 | static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) | |
169 | { | |
bd697222 | 170 | u8 hmac[SHA256_DIGEST_SIZE]; |
ec3edaa7 PK |
171 | u64 thmac; |
172 | ||
173 | subflow_generate_hmac(subflow->remote_key, subflow->local_key, | |
174 | subflow->remote_nonce, subflow->local_nonce, | |
175 | hmac); | |
176 | ||
177 | thmac = get_unaligned_be64(hmac); | |
178 | pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", | |
179 | subflow, subflow->token, | |
180 | (unsigned long long)thmac, | |
181 | (unsigned long long)subflow->thmac); | |
182 | ||
183 | return thmac == subflow->thmac; | |
184 | } | |
185 | ||
cec37a6e PK |
186 | static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) |
187 | { | |
188 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
cfde141e | 189 | struct mptcp_options_received mp_opt; |
c3c123d1 | 190 | struct sock *parent = subflow->conn; |
cec37a6e PK |
191 | |
192 | subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); | |
193 | ||
1200832c | 194 | if (inet_sk_state_load(parent) == TCP_SYN_SENT) { |
c3c123d1 DC |
195 | inet_sk_state_store(parent, TCP_ESTABLISHED); |
196 | parent->sk_state_change(parent); | |
197 | } | |
198 | ||
263e1201 PA |
199 | /* be sure no special action on any packet other than syn-ack */ |
200 | if (subflow->conn_finished) | |
201 | return; | |
202 | ||
b0977bb2 | 203 | subflow->rel_write_seq = 1; |
263e1201 | 204 | subflow->conn_finished = 1; |
e1ff9e82 DC |
205 | subflow->ssn_offset = TCP_SKB_CB(skb)->seq; |
206 | pr_debug("subflow=%p synack seq=%x", subflow, subflow->ssn_offset); | |
263e1201 | 207 | |
cfde141e | 208 | mptcp_get_options(skb, &mp_opt); |
fa25e815 PA |
209 | if (subflow->request_mptcp) { |
210 | if (!mp_opt.mp_capable) { | |
211 | MPTCP_INC_STATS(sock_net(sk), | |
212 | MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); | |
213 | mptcp_do_fallback(sk); | |
214 | pr_fallback(mptcp_sk(subflow->conn)); | |
215 | goto fallback; | |
216 | } | |
217 | ||
263e1201 PA |
218 | subflow->mp_capable = 1; |
219 | subflow->can_ack = 1; | |
cfde141e | 220 | subflow->remote_key = mp_opt.sndr_key; |
263e1201 PA |
221 | pr_debug("subflow=%p, remote_key=%llu", subflow, |
222 | subflow->remote_key); | |
fa25e815 PA |
223 | mptcp_finish_connect(sk); |
224 | } else if (subflow->request_join) { | |
225 | u8 hmac[SHA256_DIGEST_SIZE]; | |
226 | ||
227 | if (!mp_opt.mp_join) | |
228 | goto do_reset; | |
229 | ||
cfde141e PA |
230 | subflow->thmac = mp_opt.thmac; |
231 | subflow->remote_nonce = mp_opt.nonce; | |
263e1201 PA |
232 | pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow, |
233 | subflow->thmac, subflow->remote_nonce); | |
263e1201 | 234 | |
ec3edaa7 | 235 | if (!subflow_thmac_valid(subflow)) { |
fc518953 | 236 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC); |
ec3edaa7 PK |
237 | goto do_reset; |
238 | } | |
239 | ||
240 | subflow_generate_hmac(subflow->local_key, subflow->remote_key, | |
241 | subflow->local_nonce, | |
242 | subflow->remote_nonce, | |
bd697222 | 243 | hmac); |
bd697222 | 244 | memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN); |
ec3edaa7 | 245 | |
ec3edaa7 PK |
246 | if (!mptcp_finish_join(sk)) |
247 | goto do_reset; | |
248 | ||
fa25e815 | 249 | subflow->mp_join = 1; |
fc518953 | 250 | MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX); |
fa25e815 PA |
251 | } else if (mptcp_check_fallback(sk)) { |
252 | fallback: | |
253 | mptcp_rcv_space_init(mptcp_sk(parent), sk); | |
cec37a6e | 254 | } |
fa25e815 PA |
255 | return; |
256 | ||
257 | do_reset: | |
258 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
259 | tcp_done(sk); | |
cec37a6e PK |
260 | } |
261 | ||
262 | static struct request_sock_ops subflow_request_sock_ops; | |
263 | static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops; | |
264 | ||
265 | static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
266 | { | |
267 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
268 | ||
269 | pr_debug("subflow=%p", subflow); | |
270 | ||
271 | /* Never answer to SYNs sent to broadcast or multicast */ | |
272 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
273 | goto drop; | |
274 | ||
275 | return tcp_conn_request(&subflow_request_sock_ops, | |
276 | &subflow_request_sock_ipv4_ops, | |
277 | sk, skb); | |
278 | drop: | |
279 | tcp_listendrop(sk); | |
280 | return 0; | |
281 | } | |
282 | ||
283 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
284 | static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; | |
285 | static struct inet_connection_sock_af_ops subflow_v6_specific; | |
286 | static struct inet_connection_sock_af_ops subflow_v6m_specific; | |
287 | ||
288 | static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) | |
289 | { | |
290 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
291 | ||
292 | pr_debug("subflow=%p", subflow); | |
293 | ||
294 | if (skb->protocol == htons(ETH_P_IP)) | |
295 | return subflow_v4_conn_request(sk, skb); | |
296 | ||
297 | if (!ipv6_unicast_destination(skb)) | |
298 | goto drop; | |
299 | ||
300 | return tcp_conn_request(&subflow_request_sock_ops, | |
301 | &subflow_request_sock_ipv6_ops, sk, skb); | |
302 | ||
303 | drop: | |
304 | tcp_listendrop(sk); | |
305 | return 0; /* don't send reset */ | |
306 | } | |
307 | #endif | |
308 | ||
f296234c PK |
309 | /* validate hmac received in third ACK */ |
310 | static bool subflow_hmac_valid(const struct request_sock *req, | |
cfde141e | 311 | const struct mptcp_options_received *mp_opt) |
f296234c PK |
312 | { |
313 | const struct mptcp_subflow_request_sock *subflow_req; | |
bd697222 | 314 | u8 hmac[SHA256_DIGEST_SIZE]; |
f296234c | 315 | struct mptcp_sock *msk; |
f296234c PK |
316 | |
317 | subflow_req = mptcp_subflow_rsk(req); | |
8fd4de12 | 318 | msk = subflow_req->msk; |
f296234c PK |
319 | if (!msk) |
320 | return false; | |
321 | ||
322 | subflow_generate_hmac(msk->remote_key, msk->local_key, | |
323 | subflow_req->remote_nonce, | |
324 | subflow_req->local_nonce, hmac); | |
325 | ||
8fd4de12 | 326 | return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN); |
f296234c PK |
327 | } |
328 | ||
df1036da FW |
329 | static void mptcp_sock_destruct(struct sock *sk) |
330 | { | |
331 | /* if new mptcp socket isn't accepted, it is free'd | |
332 | * from the tcp listener sockets request queue, linked | |
333 | * from req->sk. The tcp socket is released. | |
334 | * This calls the ULP release function which will | |
335 | * also remove the mptcp socket, via | |
336 | * sock_put(ctx->conn). | |
337 | * | |
338 | * Problem is that the mptcp socket will not be in | |
339 | * SYN_RECV state and doesn't have SOCK_DEAD flag. | |
340 | * Both result in warnings from inet_sock_destruct. | |
341 | */ | |
342 | ||
343 | if (sk->sk_state == TCP_SYN_RECV) { | |
344 | sk->sk_state = TCP_CLOSE; | |
345 | WARN_ON_ONCE(sk->sk_socket); | |
346 | sock_orphan(sk); | |
347 | } | |
348 | ||
2c5ebd00 | 349 | mptcp_token_destroy(mptcp_sk(sk)); |
df1036da FW |
350 | inet_sock_destruct(sk); |
351 | } | |
352 | ||
9f5ca6a5 FW |
353 | static void mptcp_force_close(struct sock *sk) |
354 | { | |
355 | inet_sk_state_store(sk, TCP_CLOSE); | |
356 | sk_common_release(sk); | |
357 | } | |
358 | ||
4c8941de PA |
359 | static void subflow_ulp_fallback(struct sock *sk, |
360 | struct mptcp_subflow_context *old_ctx) | |
361 | { | |
362 | struct inet_connection_sock *icsk = inet_csk(sk); | |
363 | ||
364 | mptcp_subflow_tcp_fallback(sk, old_ctx); | |
365 | icsk->icsk_ulp_ops = NULL; | |
366 | rcu_assign_pointer(icsk->icsk_ulp_data, NULL); | |
367 | tcp_sk(sk)->is_mptcp = 0; | |
368 | } | |
369 | ||
39884604 PA |
370 | static void subflow_drop_ctx(struct sock *ssk) |
371 | { | |
372 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); | |
373 | ||
374 | if (!ctx) | |
375 | return; | |
376 | ||
377 | subflow_ulp_fallback(ssk, ctx); | |
378 | if (ctx->conn) | |
379 | sock_put(ctx->conn); | |
380 | ||
381 | kfree_rcu(ctx, rcu); | |
382 | } | |
383 | ||
b93df08c PA |
384 | void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, |
385 | struct mptcp_options_received *mp_opt) | |
386 | { | |
387 | struct mptcp_sock *msk = mptcp_sk(subflow->conn); | |
388 | ||
389 | subflow->remote_key = mp_opt->sndr_key; | |
390 | subflow->fully_established = 1; | |
391 | subflow->can_ack = 1; | |
392 | WRITE_ONCE(msk->fully_established, true); | |
393 | } | |
394 | ||
cec37a6e PK |
395 | static struct sock *subflow_syn_recv_sock(const struct sock *sk, |
396 | struct sk_buff *skb, | |
397 | struct request_sock *req, | |
398 | struct dst_entry *dst, | |
399 | struct request_sock *req_unhash, | |
400 | bool *own_req) | |
401 | { | |
402 | struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk); | |
cc7972ea | 403 | struct mptcp_subflow_request_sock *subflow_req; |
cfde141e | 404 | struct mptcp_options_received mp_opt; |
9e365ff5 | 405 | bool fallback, fallback_is_fatal; |
58b09919 | 406 | struct sock *new_msk = NULL; |
cec37a6e PK |
407 | struct sock *child; |
408 | ||
409 | pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); | |
410 | ||
9e365ff5 PA |
411 | /* After child creation we must look for 'mp_capable' even when options |
412 | * are not parsed | |
cfde141e PA |
413 | */ |
414 | mp_opt.mp_capable = 0; | |
9e365ff5 PA |
415 | |
416 | /* hopefully temporary handling for MP_JOIN+syncookie */ | |
417 | subflow_req = mptcp_subflow_rsk(req); | |
b7514694 | 418 | fallback_is_fatal = tcp_rsk(req)->is_mptcp && subflow_req->mp_join; |
9e365ff5 PA |
419 | fallback = !tcp_rsk(req)->is_mptcp; |
420 | if (fallback) | |
ae2dd716 FW |
421 | goto create_child; |
422 | ||
d22f4988 | 423 | /* if the sk is MP_CAPABLE, we try to fetch the client key */ |
cc7972ea | 424 | if (subflow_req->mp_capable) { |
d22f4988 CP |
425 | if (TCP_SKB_CB(skb)->seq != subflow_req->ssn_offset + 1) { |
426 | /* here we can receive and accept an in-window, | |
427 | * out-of-order pkt, which will not carry the MP_CAPABLE | |
428 | * opt even on mptcp enabled paths | |
429 | */ | |
58b09919 | 430 | goto create_msk; |
d22f4988 CP |
431 | } |
432 | ||
cfde141e PA |
433 | mptcp_get_options(skb, &mp_opt); |
434 | if (!mp_opt.mp_capable) { | |
4c8941de | 435 | fallback = true; |
58b09919 | 436 | goto create_child; |
d22f4988 | 437 | } |
58b09919 PA |
438 | |
439 | create_msk: | |
cfde141e | 440 | new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); |
58b09919 | 441 | if (!new_msk) |
4c8941de | 442 | fallback = true; |
f296234c | 443 | } else if (subflow_req->mp_join) { |
cfde141e PA |
444 | mptcp_get_options(skb, &mp_opt); |
445 | if (!mp_opt.mp_join || | |
446 | !subflow_hmac_valid(req, &mp_opt)) { | |
fc518953 | 447 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); |
9e365ff5 | 448 | fallback = true; |
fc518953 | 449 | } |
cc7972ea | 450 | } |
cec37a6e | 451 | |
d22f4988 | 452 | create_child: |
cec37a6e PK |
453 | child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, |
454 | req_unhash, own_req); | |
455 | ||
456 | if (child && *own_req) { | |
79c0949e PK |
457 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); |
458 | ||
90bf4513 PA |
459 | tcp_rsk(req)->drop_req = false; |
460 | ||
4c8941de PA |
461 | /* we need to fallback on ctx allocation failure and on pre-reqs |
462 | * checking above. In the latter scenario we additionally need | |
463 | * to reset the context to non MPTCP status. | |
79c0949e | 464 | */ |
4c8941de | 465 | if (!ctx || fallback) { |
f296234c | 466 | if (fallback_is_fatal) |
729cd643 | 467 | goto dispose_child; |
4c8941de | 468 | |
39884604 | 469 | subflow_drop_ctx(child); |
58b09919 | 470 | goto out; |
f296234c | 471 | } |
79c0949e PK |
472 | |
473 | if (ctx->mp_capable) { | |
b93df08c PA |
474 | /* this can't race with mptcp_close(), as the msk is |
475 | * not yet exposted to user-space | |
476 | */ | |
477 | inet_sk_state_store((void *)new_msk, TCP_ESTABLISHED); | |
478 | ||
58b09919 PA |
479 | /* new mpc subflow takes ownership of the newly |
480 | * created mptcp socket | |
481 | */ | |
df1036da | 482 | new_msk->sk_destruct = mptcp_sock_destruct; |
1b1c7a0e | 483 | mptcp_pm_new_connection(mptcp_sk(new_msk), 1); |
2c5ebd00 | 484 | mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); |
58b09919 PA |
485 | ctx->conn = new_msk; |
486 | new_msk = NULL; | |
fca5c82c PA |
487 | |
488 | /* with OoO packets we can reach here without ingress | |
489 | * mpc option | |
490 | */ | |
b93df08c PA |
491 | if (mp_opt.mp_capable) |
492 | mptcp_subflow_fully_established(ctx, &mp_opt); | |
f296234c PK |
493 | } else if (ctx->mp_join) { |
494 | struct mptcp_sock *owner; | |
495 | ||
8fd4de12 | 496 | owner = subflow_req->msk; |
f296234c | 497 | if (!owner) |
729cd643 | 498 | goto dispose_child; |
f296234c | 499 | |
8fd4de12 PA |
500 | /* move the msk reference ownership to the subflow */ |
501 | subflow_req->msk = NULL; | |
f296234c PK |
502 | ctx->conn = (struct sock *)owner; |
503 | if (!mptcp_finish_join(child)) | |
729cd643 | 504 | goto dispose_child; |
fc518953 FW |
505 | |
506 | SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); | |
90bf4513 | 507 | tcp_rsk(req)->drop_req = true; |
cec37a6e PK |
508 | } |
509 | } | |
510 | ||
58b09919 PA |
511 | out: |
512 | /* dispose of the left over mptcp master, if any */ | |
513 | if (unlikely(new_msk)) | |
9f5ca6a5 | 514 | mptcp_force_close(new_msk); |
4c8941de PA |
515 | |
516 | /* check for expected invariant - should never trigger, just help | |
517 | * catching eariler subtle bugs | |
518 | */ | |
ac2b47fb | 519 | WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp && |
4c8941de PA |
520 | (!mptcp_subflow_ctx(child) || |
521 | !mptcp_subflow_ctx(child)->conn)); | |
cec37a6e | 522 | return child; |
f296234c | 523 | |
729cd643 | 524 | dispose_child: |
39884604 | 525 | subflow_drop_ctx(child); |
729cd643 | 526 | tcp_rsk(req)->drop_req = true; |
729cd643 | 527 | inet_csk_prepare_for_destroy_sock(child); |
f296234c | 528 | tcp_done(child); |
97e61751 | 529 | req->rsk_ops->send_reset(sk, skb); |
729cd643 PA |
530 | |
531 | /* The last child reference will be released by the caller */ | |
532 | return child; | |
cec37a6e PK |
533 | } |
534 | ||
535 | static struct inet_connection_sock_af_ops subflow_specific; | |
536 | ||
648ef4b8 MM |
537 | enum mapping_status { |
538 | MAPPING_OK, | |
539 | MAPPING_INVALID, | |
540 | MAPPING_EMPTY, | |
e1ff9e82 DC |
541 | MAPPING_DATA_FIN, |
542 | MAPPING_DUMMY | |
648ef4b8 MM |
543 | }; |
544 | ||
545 | static u64 expand_seq(u64 old_seq, u16 old_data_len, u64 seq) | |
546 | { | |
547 | if ((u32)seq == (u32)old_seq) | |
548 | return old_seq; | |
549 | ||
550 | /* Assume map covers data not mapped yet. */ | |
551 | return seq | ((old_seq + old_data_len + 1) & GENMASK_ULL(63, 32)); | |
552 | } | |
553 | ||
554 | static void warn_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) | |
555 | { | |
556 | WARN_ONCE(1, "Bad mapping: ssn=%d map_seq=%d map_data_len=%d", | |
557 | ssn, subflow->map_subflow_seq, subflow->map_data_len); | |
558 | } | |
559 | ||
560 | static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) | |
561 | { | |
562 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
563 | unsigned int skb_consumed; | |
564 | ||
565 | skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; | |
566 | if (WARN_ON_ONCE(skb_consumed >= skb->len)) | |
567 | return true; | |
568 | ||
569 | return skb->len - skb_consumed <= subflow->map_data_len - | |
570 | mptcp_subflow_get_map_offset(subflow); | |
571 | } | |
572 | ||
573 | static bool validate_mapping(struct sock *ssk, struct sk_buff *skb) | |
574 | { | |
575 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
576 | u32 ssn = tcp_sk(ssk)->copied_seq - subflow->ssn_offset; | |
577 | ||
578 | if (unlikely(before(ssn, subflow->map_subflow_seq))) { | |
579 | /* Mapping covers data later in the subflow stream, | |
580 | * currently unsupported. | |
581 | */ | |
582 | warn_bad_map(subflow, ssn); | |
583 | return false; | |
584 | } | |
585 | if (unlikely(!before(ssn, subflow->map_subflow_seq + | |
586 | subflow->map_data_len))) { | |
587 | /* Mapping does covers past subflow data, invalid */ | |
588 | warn_bad_map(subflow, ssn + skb->len); | |
589 | return false; | |
590 | } | |
591 | return true; | |
592 | } | |
593 | ||
594 | static enum mapping_status get_mapping_status(struct sock *ssk) | |
595 | { | |
596 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
597 | struct mptcp_ext *mpext; | |
598 | struct sk_buff *skb; | |
599 | u16 data_len; | |
600 | u64 map_seq; | |
601 | ||
602 | skb = skb_peek(&ssk->sk_receive_queue); | |
603 | if (!skb) | |
604 | return MAPPING_EMPTY; | |
605 | ||
e1ff9e82 DC |
606 | if (mptcp_check_fallback(ssk)) |
607 | return MAPPING_DUMMY; | |
608 | ||
648ef4b8 MM |
609 | mpext = mptcp_get_ext(skb); |
610 | if (!mpext || !mpext->use_map) { | |
611 | if (!subflow->map_valid && !skb->len) { | |
612 | /* the TCP stack deliver 0 len FIN pkt to the receive | |
613 | * queue, that is the only 0len pkts ever expected here, | |
614 | * and we can admit no mapping only for 0 len pkts | |
615 | */ | |
616 | if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) | |
617 | WARN_ONCE(1, "0len seq %d:%d flags %x", | |
618 | TCP_SKB_CB(skb)->seq, | |
619 | TCP_SKB_CB(skb)->end_seq, | |
620 | TCP_SKB_CB(skb)->tcp_flags); | |
621 | sk_eat_skb(ssk, skb); | |
622 | return MAPPING_EMPTY; | |
623 | } | |
624 | ||
625 | if (!subflow->map_valid) | |
626 | return MAPPING_INVALID; | |
627 | ||
628 | goto validate_seq; | |
629 | } | |
630 | ||
631 | pr_debug("seq=%llu is64=%d ssn=%u data_len=%u data_fin=%d", | |
632 | mpext->data_seq, mpext->dsn64, mpext->subflow_seq, | |
633 | mpext->data_len, mpext->data_fin); | |
634 | ||
635 | data_len = mpext->data_len; | |
636 | if (data_len == 0) { | |
637 | pr_err("Infinite mapping not handled"); | |
fc518953 | 638 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); |
648ef4b8 MM |
639 | return MAPPING_INVALID; |
640 | } | |
641 | ||
642 | if (mpext->data_fin == 1) { | |
643 | if (data_len == 1) { | |
644 | pr_debug("DATA_FIN with no payload"); | |
645 | if (subflow->map_valid) { | |
646 | /* A DATA_FIN might arrive in a DSS | |
647 | * option before the previous mapping | |
648 | * has been fully consumed. Continue | |
649 | * handling the existing mapping. | |
650 | */ | |
651 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
652 | return MAPPING_OK; | |
653 | } else { | |
654 | return MAPPING_DATA_FIN; | |
655 | } | |
656 | } | |
657 | ||
658 | /* Adjust for DATA_FIN using 1 byte of sequence space */ | |
659 | data_len--; | |
660 | } | |
661 | ||
662 | if (!mpext->dsn64) { | |
663 | map_seq = expand_seq(subflow->map_seq, subflow->map_data_len, | |
664 | mpext->data_seq); | |
a0c1d0ea | 665 | subflow->use_64bit_ack = 0; |
648ef4b8 MM |
666 | pr_debug("expanded seq=%llu", subflow->map_seq); |
667 | } else { | |
668 | map_seq = mpext->data_seq; | |
a0c1d0ea | 669 | subflow->use_64bit_ack = 1; |
648ef4b8 MM |
670 | } |
671 | ||
672 | if (subflow->map_valid) { | |
673 | /* Allow replacing only with an identical map */ | |
674 | if (subflow->map_seq == map_seq && | |
675 | subflow->map_subflow_seq == mpext->subflow_seq && | |
676 | subflow->map_data_len == data_len) { | |
677 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
678 | return MAPPING_OK; | |
679 | } | |
680 | ||
681 | /* If this skb data are fully covered by the current mapping, | |
682 | * the new map would need caching, which is not supported | |
683 | */ | |
fc518953 FW |
684 | if (skb_is_fully_mapped(ssk, skb)) { |
685 | MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH); | |
648ef4b8 | 686 | return MAPPING_INVALID; |
fc518953 | 687 | } |
648ef4b8 MM |
688 | |
689 | /* will validate the next map after consuming the current one */ | |
690 | return MAPPING_OK; | |
691 | } | |
692 | ||
693 | subflow->map_seq = map_seq; | |
694 | subflow->map_subflow_seq = mpext->subflow_seq; | |
695 | subflow->map_data_len = data_len; | |
696 | subflow->map_valid = 1; | |
d22f4988 | 697 | subflow->mpc_map = mpext->mpc_map; |
648ef4b8 MM |
698 | pr_debug("new map seq=%llu subflow_seq=%u data_len=%u", |
699 | subflow->map_seq, subflow->map_subflow_seq, | |
700 | subflow->map_data_len); | |
701 | ||
702 | validate_seq: | |
703 | /* we revalidate valid mapping on new skb, because we must ensure | |
704 | * the current skb is completely covered by the available mapping | |
705 | */ | |
706 | if (!validate_mapping(ssk, skb)) | |
707 | return MAPPING_INVALID; | |
708 | ||
709 | skb_ext_del(skb, SKB_EXT_MPTCP); | |
710 | return MAPPING_OK; | |
711 | } | |
712 | ||
bfae9dae FW |
713 | static int subflow_read_actor(read_descriptor_t *desc, |
714 | struct sk_buff *skb, | |
715 | unsigned int offset, size_t len) | |
716 | { | |
717 | size_t copy_len = min(desc->count, len); | |
718 | ||
719 | desc->count -= copy_len; | |
720 | ||
721 | pr_debug("flushed %zu bytes, %zu left", copy_len, desc->count); | |
722 | return copy_len; | |
723 | } | |
724 | ||
648ef4b8 MM |
725 | static bool subflow_check_data_avail(struct sock *ssk) |
726 | { | |
727 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
728 | enum mapping_status status; | |
729 | struct mptcp_sock *msk; | |
730 | struct sk_buff *skb; | |
731 | ||
732 | pr_debug("msk=%p ssk=%p data_avail=%d skb=%p", subflow->conn, ssk, | |
733 | subflow->data_avail, skb_peek(&ssk->sk_receive_queue)); | |
734 | if (subflow->data_avail) | |
735 | return true; | |
736 | ||
648ef4b8 MM |
737 | msk = mptcp_sk(subflow->conn); |
738 | for (;;) { | |
739 | u32 map_remaining; | |
740 | size_t delta; | |
741 | u64 ack_seq; | |
742 | u64 old_ack; | |
743 | ||
744 | status = get_mapping_status(ssk); | |
745 | pr_debug("msk=%p ssk=%p status=%d", msk, ssk, status); | |
746 | if (status == MAPPING_INVALID) { | |
747 | ssk->sk_err = EBADMSG; | |
748 | goto fatal; | |
749 | } | |
e1ff9e82 DC |
750 | if (status == MAPPING_DUMMY) { |
751 | __mptcp_do_fallback(msk); | |
752 | skb = skb_peek(&ssk->sk_receive_queue); | |
753 | subflow->map_valid = 1; | |
754 | subflow->map_seq = READ_ONCE(msk->ack_seq); | |
755 | subflow->map_data_len = skb->len; | |
756 | subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq - | |
757 | subflow->ssn_offset; | |
758 | return true; | |
759 | } | |
648ef4b8 MM |
760 | |
761 | if (status != MAPPING_OK) | |
762 | return false; | |
763 | ||
764 | skb = skb_peek(&ssk->sk_receive_queue); | |
765 | if (WARN_ON_ONCE(!skb)) | |
766 | return false; | |
767 | ||
d22f4988 CP |
768 | /* if msk lacks the remote key, this subflow must provide an |
769 | * MP_CAPABLE-based mapping | |
770 | */ | |
771 | if (unlikely(!READ_ONCE(msk->can_ack))) { | |
772 | if (!subflow->mpc_map) { | |
773 | ssk->sk_err = EBADMSG; | |
774 | goto fatal; | |
775 | } | |
776 | WRITE_ONCE(msk->remote_key, subflow->remote_key); | |
777 | WRITE_ONCE(msk->ack_seq, subflow->map_seq); | |
778 | WRITE_ONCE(msk->can_ack, true); | |
779 | } | |
780 | ||
648ef4b8 MM |
781 | old_ack = READ_ONCE(msk->ack_seq); |
782 | ack_seq = mptcp_subflow_get_mapped_dsn(subflow); | |
783 | pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, | |
784 | ack_seq); | |
785 | if (ack_seq == old_ack) | |
786 | break; | |
787 | ||
788 | /* only accept in-sequence mapping. Old values are spurious | |
789 | * retransmission; we can hit "future" values on active backup | |
790 | * subflow switch, we relay on retransmissions to get | |
791 | * in-sequence data. | |
792 | * Cuncurrent subflows support will require subflow data | |
793 | * reordering | |
794 | */ | |
795 | map_remaining = subflow->map_data_len - | |
796 | mptcp_subflow_get_map_offset(subflow); | |
797 | if (before64(ack_seq, old_ack)) | |
798 | delta = min_t(size_t, old_ack - ack_seq, map_remaining); | |
799 | else | |
800 | delta = min_t(size_t, ack_seq - old_ack, map_remaining); | |
801 | ||
802 | /* discard mapped data */ | |
803 | pr_debug("discarding %zu bytes, current map len=%d", delta, | |
804 | map_remaining); | |
805 | if (delta) { | |
648ef4b8 MM |
806 | read_descriptor_t desc = { |
807 | .count = delta, | |
648ef4b8 MM |
808 | }; |
809 | int ret; | |
810 | ||
bfae9dae | 811 | ret = tcp_read_sock(ssk, &desc, subflow_read_actor); |
648ef4b8 MM |
812 | if (ret < 0) { |
813 | ssk->sk_err = -ret; | |
814 | goto fatal; | |
815 | } | |
816 | if (ret < delta) | |
817 | return false; | |
818 | if (delta == map_remaining) | |
819 | subflow->map_valid = 0; | |
820 | } | |
821 | } | |
822 | return true; | |
823 | ||
824 | fatal: | |
825 | /* fatal protocol error, close the socket */ | |
826 | /* This barrier is coupled with smp_rmb() in tcp_poll() */ | |
827 | smp_wmb(); | |
828 | ssk->sk_error_report(ssk); | |
829 | tcp_set_state(ssk, TCP_CLOSE); | |
830 | tcp_send_active_reset(ssk, GFP_ATOMIC); | |
831 | return false; | |
832 | } | |
833 | ||
834 | bool mptcp_subflow_data_available(struct sock *sk) | |
835 | { | |
836 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
837 | struct sk_buff *skb; | |
838 | ||
839 | /* check if current mapping is still valid */ | |
840 | if (subflow->map_valid && | |
841 | mptcp_subflow_get_map_offset(subflow) >= subflow->map_data_len) { | |
842 | subflow->map_valid = 0; | |
843 | subflow->data_avail = 0; | |
844 | ||
845 | pr_debug("Done with mapping: seq=%u data_len=%u", | |
846 | subflow->map_subflow_seq, | |
847 | subflow->map_data_len); | |
848 | } | |
849 | ||
850 | if (!subflow_check_data_avail(sk)) { | |
851 | subflow->data_avail = 0; | |
852 | return false; | |
853 | } | |
854 | ||
855 | skb = skb_peek(&sk->sk_receive_queue); | |
856 | subflow->data_avail = skb && | |
857 | before(tcp_sk(sk)->copied_seq, TCP_SKB_CB(skb)->end_seq); | |
858 | return subflow->data_avail; | |
859 | } | |
860 | ||
071c8ed6 FW |
861 | /* If ssk has an mptcp parent socket, use the mptcp rcvbuf occupancy, |
862 | * not the ssk one. | |
863 | * | |
864 | * In mptcp, rwin is about the mptcp-level connection data. | |
865 | * | |
866 | * Data that is still on the ssk rx queue can thus be ignored, | |
867 | * as far as mptcp peer is concerened that data is still inflight. | |
868 | * DSS ACK is updated when skb is moved to the mptcp rx queue. | |
869 | */ | |
870 | void mptcp_space(const struct sock *ssk, int *space, int *full_space) | |
871 | { | |
872 | const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
873 | const struct sock *sk = subflow->conn; | |
874 | ||
875 | *space = tcp_space(sk); | |
876 | *full_space = tcp_full_space(sk); | |
877 | } | |
878 | ||
648ef4b8 MM |
879 | static void subflow_data_ready(struct sock *sk) |
880 | { | |
881 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
8c728940 | 882 | u16 state = 1 << inet_sk_state_load(sk); |
648ef4b8 | 883 | struct sock *parent = subflow->conn; |
e1ff9e82 | 884 | struct mptcp_sock *msk; |
648ef4b8 | 885 | |
e1ff9e82 | 886 | msk = mptcp_sk(parent); |
8c728940 | 887 | if (state & TCPF_LISTEN) { |
e1ff9e82 | 888 | set_bit(MPTCP_DATA_READY, &msk->flags); |
dc093db5 | 889 | parent->sk_data_ready(parent); |
648ef4b8 MM |
890 | return; |
891 | } | |
892 | ||
e1ff9e82 | 893 | WARN_ON_ONCE(!__mptcp_check_fallback(msk) && !subflow->mp_capable && |
8c728940 | 894 | !subflow->mp_join && !(state & TCPF_CLOSE)); |
e1ff9e82 | 895 | |
101f6f85 | 896 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 897 | mptcp_data_ready(parent, sk); |
648ef4b8 MM |
898 | } |
899 | ||
900 | static void subflow_write_space(struct sock *sk) | |
901 | { | |
902 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
903 | struct sock *parent = subflow->conn; | |
904 | ||
905 | sk_stream_write_space(sk); | |
dc093db5 | 906 | if (sk_stream_is_writeable(sk)) { |
1891c4a0 FW |
907 | set_bit(MPTCP_SEND_SPACE, &mptcp_sk(parent)->flags); |
908 | smp_mb__after_atomic(); | |
909 | /* set SEND_SPACE before sk_stream_write_space clears NOSPACE */ | |
648ef4b8 MM |
910 | sk_stream_write_space(parent); |
911 | } | |
912 | } | |
913 | ||
cec37a6e PK |
914 | static struct inet_connection_sock_af_ops * |
915 | subflow_default_af_ops(struct sock *sk) | |
916 | { | |
917 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
918 | if (sk->sk_family == AF_INET6) | |
919 | return &subflow_v6_specific; | |
920 | #endif | |
921 | return &subflow_specific; | |
922 | } | |
923 | ||
cec37a6e | 924 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
31484d56 GU |
925 | void mptcpv6_handle_mapped(struct sock *sk, bool mapped) |
926 | { | |
cec37a6e PK |
927 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); |
928 | struct inet_connection_sock *icsk = inet_csk(sk); | |
929 | struct inet_connection_sock_af_ops *target; | |
930 | ||
931 | target = mapped ? &subflow_v6m_specific : subflow_default_af_ops(sk); | |
932 | ||
933 | pr_debug("subflow=%p family=%d ops=%p target=%p mapped=%d", | |
edc7e489 | 934 | subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped); |
cec37a6e PK |
935 | |
936 | if (likely(icsk->icsk_af_ops == target)) | |
937 | return; | |
938 | ||
939 | subflow->icsk_af_ops = icsk->icsk_af_ops; | |
940 | icsk->icsk_af_ops = target; | |
cec37a6e | 941 | } |
31484d56 | 942 | #endif |
cec37a6e | 943 | |
ec3edaa7 PK |
944 | static void mptcp_info2sockaddr(const struct mptcp_addr_info *info, |
945 | struct sockaddr_storage *addr) | |
946 | { | |
947 | memset(addr, 0, sizeof(*addr)); | |
948 | addr->ss_family = info->family; | |
949 | if (addr->ss_family == AF_INET) { | |
950 | struct sockaddr_in *in_addr = (struct sockaddr_in *)addr; | |
951 | ||
952 | in_addr->sin_addr = info->addr; | |
953 | in_addr->sin_port = info->port; | |
954 | } | |
955 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
956 | else if (addr->ss_family == AF_INET6) { | |
957 | struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr; | |
958 | ||
959 | in6_addr->sin6_addr = info->addr6; | |
960 | in6_addr->sin6_port = info->port; | |
961 | } | |
962 | #endif | |
963 | } | |
964 | ||
965 | int __mptcp_subflow_connect(struct sock *sk, int ifindex, | |
966 | const struct mptcp_addr_info *loc, | |
967 | const struct mptcp_addr_info *remote) | |
968 | { | |
969 | struct mptcp_sock *msk = mptcp_sk(sk); | |
970 | struct mptcp_subflow_context *subflow; | |
971 | struct sockaddr_storage addr; | |
6bad912b | 972 | int local_id = loc->id; |
ec3edaa7 | 973 | struct socket *sf; |
6bad912b | 974 | struct sock *ssk; |
ec3edaa7 PK |
975 | u32 remote_token; |
976 | int addrlen; | |
977 | int err; | |
978 | ||
b93df08c | 979 | if (!mptcp_is_fully_established(sk)) |
ec3edaa7 PK |
980 | return -ENOTCONN; |
981 | ||
982 | err = mptcp_subflow_create_socket(sk, &sf); | |
983 | if (err) | |
984 | return err; | |
985 | ||
6bad912b PA |
986 | ssk = sf->sk; |
987 | subflow = mptcp_subflow_ctx(ssk); | |
988 | do { | |
989 | get_random_bytes(&subflow->local_nonce, sizeof(u32)); | |
990 | } while (!subflow->local_nonce); | |
991 | ||
992 | if (!local_id) { | |
993 | err = mptcp_pm_get_local_id(msk, (struct sock_common *)ssk); | |
994 | if (err < 0) | |
995 | goto failed; | |
996 | ||
997 | local_id = err; | |
998 | } | |
999 | ||
ec3edaa7 PK |
1000 | subflow->remote_key = msk->remote_key; |
1001 | subflow->local_key = msk->local_key; | |
1002 | subflow->token = msk->token; | |
1003 | mptcp_info2sockaddr(loc, &addr); | |
1004 | ||
1005 | addrlen = sizeof(struct sockaddr_in); | |
1006 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1007 | if (loc->family == AF_INET6) | |
1008 | addrlen = sizeof(struct sockaddr_in6); | |
1009 | #endif | |
6bad912b | 1010 | ssk->sk_bound_dev_if = ifindex; |
ec3edaa7 PK |
1011 | err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen); |
1012 | if (err) | |
1013 | goto failed; | |
1014 | ||
1015 | mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL); | |
6bad912b PA |
1016 | pr_debug("msk=%p remote_token=%u local_id=%d", msk, remote_token, |
1017 | local_id); | |
ec3edaa7 | 1018 | subflow->remote_token = remote_token; |
6bad912b | 1019 | subflow->local_id = local_id; |
ec3edaa7 PK |
1020 | subflow->request_join = 1; |
1021 | subflow->request_bkup = 1; | |
1022 | mptcp_info2sockaddr(remote, &addr); | |
1023 | ||
1024 | err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK); | |
1025 | if (err && err != -EINPROGRESS) | |
1026 | goto failed; | |
1027 | ||
1028 | spin_lock_bh(&msk->join_list_lock); | |
1029 | list_add_tail(&subflow->node, &msk->join_list); | |
1030 | spin_unlock_bh(&msk->join_list_lock); | |
1031 | ||
1032 | return err; | |
1033 | ||
1034 | failed: | |
1035 | sock_release(sf); | |
1036 | return err; | |
1037 | } | |
1038 | ||
2303f994 PK |
1039 | int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) |
1040 | { | |
1041 | struct mptcp_subflow_context *subflow; | |
1042 | struct net *net = sock_net(sk); | |
1043 | struct socket *sf; | |
1044 | int err; | |
1045 | ||
cec37a6e PK |
1046 | err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP, |
1047 | &sf); | |
2303f994 PK |
1048 | if (err) |
1049 | return err; | |
1050 | ||
1051 | lock_sock(sf->sk); | |
1052 | ||
1053 | /* kernel sockets do not by default acquire net ref, but TCP timer | |
1054 | * needs it. | |
1055 | */ | |
1056 | sf->sk->sk_net_refcnt = 1; | |
1057 | get_net(net); | |
f6f7d8cf | 1058 | #ifdef CONFIG_PROC_FS |
2303f994 | 1059 | this_cpu_add(*net->core.sock_inuse, 1); |
f6f7d8cf | 1060 | #endif |
2303f994 PK |
1061 | err = tcp_set_ulp(sf->sk, "mptcp"); |
1062 | release_sock(sf->sk); | |
1063 | ||
b8ad540d WY |
1064 | if (err) { |
1065 | sock_release(sf); | |
2303f994 | 1066 | return err; |
b8ad540d | 1067 | } |
2303f994 | 1068 | |
7d14b0d2 PA |
1069 | /* the newly created socket really belongs to the owning MPTCP master |
1070 | * socket, even if for additional subflows the allocation is performed | |
1071 | * by a kernel workqueue. Adjust inode references, so that the | |
1072 | * procfs/diag interaces really show this one belonging to the correct | |
1073 | * user. | |
1074 | */ | |
1075 | SOCK_INODE(sf)->i_ino = SOCK_INODE(sk->sk_socket)->i_ino; | |
1076 | SOCK_INODE(sf)->i_uid = SOCK_INODE(sk->sk_socket)->i_uid; | |
1077 | SOCK_INODE(sf)->i_gid = SOCK_INODE(sk->sk_socket)->i_gid; | |
1078 | ||
2303f994 PK |
1079 | subflow = mptcp_subflow_ctx(sf->sk); |
1080 | pr_debug("subflow=%p", subflow); | |
1081 | ||
1082 | *new_sock = sf; | |
79c0949e | 1083 | sock_hold(sk); |
2303f994 PK |
1084 | subflow->conn = sk; |
1085 | ||
1086 | return 0; | |
1087 | } | |
1088 | ||
1089 | static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, | |
1090 | gfp_t priority) | |
1091 | { | |
1092 | struct inet_connection_sock *icsk = inet_csk(sk); | |
1093 | struct mptcp_subflow_context *ctx; | |
1094 | ||
1095 | ctx = kzalloc(sizeof(*ctx), priority); | |
1096 | if (!ctx) | |
1097 | return NULL; | |
1098 | ||
1099 | rcu_assign_pointer(icsk->icsk_ulp_data, ctx); | |
cec37a6e | 1100 | INIT_LIST_HEAD(&ctx->node); |
2303f994 PK |
1101 | |
1102 | pr_debug("subflow=%p", ctx); | |
1103 | ||
1104 | ctx->tcp_sock = sk; | |
1105 | ||
1106 | return ctx; | |
1107 | } | |
1108 | ||
648ef4b8 MM |
1109 | static void __subflow_state_change(struct sock *sk) |
1110 | { | |
1111 | struct socket_wq *wq; | |
1112 | ||
1113 | rcu_read_lock(); | |
1114 | wq = rcu_dereference(sk->sk_wq); | |
1115 | if (skwq_has_sleeper(wq)) | |
1116 | wake_up_interruptible_all(&wq->wait); | |
1117 | rcu_read_unlock(); | |
1118 | } | |
1119 | ||
1120 | static bool subflow_is_done(const struct sock *sk) | |
1121 | { | |
1122 | return sk->sk_shutdown & RCV_SHUTDOWN || sk->sk_state == TCP_CLOSE; | |
1123 | } | |
1124 | ||
1125 | static void subflow_state_change(struct sock *sk) | |
1126 | { | |
1127 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); | |
dc093db5 | 1128 | struct sock *parent = subflow->conn; |
648ef4b8 MM |
1129 | |
1130 | __subflow_state_change(sk); | |
1131 | ||
8fd73804 DC |
1132 | if (subflow_simultaneous_connect(sk)) { |
1133 | mptcp_do_fallback(sk); | |
a6b118fe | 1134 | mptcp_rcv_space_init(mptcp_sk(parent), sk); |
8fd73804 DC |
1135 | pr_fallback(mptcp_sk(parent)); |
1136 | subflow->conn_finished = 1; | |
1137 | if (inet_sk_state_load(parent) == TCP_SYN_SENT) { | |
1138 | inet_sk_state_store(parent, TCP_ESTABLISHED); | |
1139 | parent->sk_state_change(parent); | |
1140 | } | |
1141 | } | |
1142 | ||
648ef4b8 MM |
1143 | /* as recvmsg() does not acquire the subflow socket for ssk selection |
1144 | * a fin packet carrying a DSS can be unnoticed if we don't trigger | |
1145 | * the data available machinery here. | |
1146 | */ | |
e1ff9e82 | 1147 | if (mptcp_subflow_data_available(sk)) |
2e52213c | 1148 | mptcp_data_ready(parent, sk); |
648ef4b8 | 1149 | |
dc093db5 | 1150 | if (!(parent->sk_shutdown & RCV_SHUTDOWN) && |
648ef4b8 MM |
1151 | !subflow->rx_eof && subflow_is_done(sk)) { |
1152 | subflow->rx_eof = 1; | |
59832e24 | 1153 | mptcp_subflow_eof(parent); |
648ef4b8 MM |
1154 | } |
1155 | } | |
1156 | ||
2303f994 PK |
1157 | static int subflow_ulp_init(struct sock *sk) |
1158 | { | |
cec37a6e | 1159 | struct inet_connection_sock *icsk = inet_csk(sk); |
2303f994 PK |
1160 | struct mptcp_subflow_context *ctx; |
1161 | struct tcp_sock *tp = tcp_sk(sk); | |
1162 | int err = 0; | |
1163 | ||
1164 | /* disallow attaching ULP to a socket unless it has been | |
1165 | * created with sock_create_kern() | |
1166 | */ | |
1167 | if (!sk->sk_kern_sock) { | |
1168 | err = -EOPNOTSUPP; | |
1169 | goto out; | |
1170 | } | |
1171 | ||
1172 | ctx = subflow_create_ctx(sk, GFP_KERNEL); | |
1173 | if (!ctx) { | |
1174 | err = -ENOMEM; | |
1175 | goto out; | |
1176 | } | |
1177 | ||
1178 | pr_debug("subflow=%p, family=%d", ctx, sk->sk_family); | |
1179 | ||
1180 | tp->is_mptcp = 1; | |
cec37a6e PK |
1181 | ctx->icsk_af_ops = icsk->icsk_af_ops; |
1182 | icsk->icsk_af_ops = subflow_default_af_ops(sk); | |
648ef4b8 MM |
1183 | ctx->tcp_data_ready = sk->sk_data_ready; |
1184 | ctx->tcp_state_change = sk->sk_state_change; | |
1185 | ctx->tcp_write_space = sk->sk_write_space; | |
1186 | sk->sk_data_ready = subflow_data_ready; | |
1187 | sk->sk_write_space = subflow_write_space; | |
1188 | sk->sk_state_change = subflow_state_change; | |
2303f994 PK |
1189 | out: |
1190 | return err; | |
1191 | } | |
1192 | ||
1193 | static void subflow_ulp_release(struct sock *sk) | |
1194 | { | |
1195 | struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(sk); | |
1196 | ||
1197 | if (!ctx) | |
1198 | return; | |
1199 | ||
79c0949e PK |
1200 | if (ctx->conn) |
1201 | sock_put(ctx->conn); | |
1202 | ||
2303f994 PK |
1203 | kfree_rcu(ctx, rcu); |
1204 | } | |
1205 | ||
cec37a6e PK |
1206 | static void subflow_ulp_clone(const struct request_sock *req, |
1207 | struct sock *newsk, | |
1208 | const gfp_t priority) | |
1209 | { | |
1210 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); | |
1211 | struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk); | |
1212 | struct mptcp_subflow_context *new_ctx; | |
1213 | ||
f296234c PK |
1214 | if (!tcp_rsk(req)->is_mptcp || |
1215 | (!subflow_req->mp_capable && !subflow_req->mp_join)) { | |
648ef4b8 | 1216 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1217 | return; |
1218 | } | |
1219 | ||
1220 | new_ctx = subflow_create_ctx(newsk, priority); | |
edc7e489 | 1221 | if (!new_ctx) { |
648ef4b8 | 1222 | subflow_ulp_fallback(newsk, old_ctx); |
cec37a6e PK |
1223 | return; |
1224 | } | |
1225 | ||
1226 | new_ctx->conn_finished = 1; | |
1227 | new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; | |
648ef4b8 MM |
1228 | new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; |
1229 | new_ctx->tcp_state_change = old_ctx->tcp_state_change; | |
1230 | new_ctx->tcp_write_space = old_ctx->tcp_write_space; | |
58b09919 PA |
1231 | new_ctx->rel_write_seq = 1; |
1232 | new_ctx->tcp_sock = newsk; | |
1233 | ||
f296234c PK |
1234 | if (subflow_req->mp_capable) { |
1235 | /* see comments in subflow_syn_recv_sock(), MPTCP connection | |
1236 | * is fully established only after we receive the remote key | |
1237 | */ | |
1238 | new_ctx->mp_capable = 1; | |
f296234c PK |
1239 | new_ctx->local_key = subflow_req->local_key; |
1240 | new_ctx->token = subflow_req->token; | |
1241 | new_ctx->ssn_offset = subflow_req->ssn_offset; | |
1242 | new_ctx->idsn = subflow_req->idsn; | |
1243 | } else if (subflow_req->mp_join) { | |
ec3edaa7 | 1244 | new_ctx->ssn_offset = subflow_req->ssn_offset; |
f296234c PK |
1245 | new_ctx->mp_join = 1; |
1246 | new_ctx->fully_established = 1; | |
1247 | new_ctx->backup = subflow_req->backup; | |
1248 | new_ctx->local_id = subflow_req->local_id; | |
1249 | new_ctx->token = subflow_req->token; | |
1250 | new_ctx->thmac = subflow_req->thmac; | |
1251 | } | |
cec37a6e PK |
1252 | } |
1253 | ||
2303f994 PK |
1254 | static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { |
1255 | .name = "mptcp", | |
1256 | .owner = THIS_MODULE, | |
1257 | .init = subflow_ulp_init, | |
1258 | .release = subflow_ulp_release, | |
cec37a6e | 1259 | .clone = subflow_ulp_clone, |
2303f994 PK |
1260 | }; |
1261 | ||
cec37a6e PK |
1262 | static int subflow_ops_init(struct request_sock_ops *subflow_ops) |
1263 | { | |
1264 | subflow_ops->obj_size = sizeof(struct mptcp_subflow_request_sock); | |
1265 | subflow_ops->slab_name = "request_sock_subflow"; | |
1266 | ||
1267 | subflow_ops->slab = kmem_cache_create(subflow_ops->slab_name, | |
1268 | subflow_ops->obj_size, 0, | |
1269 | SLAB_ACCOUNT | | |
1270 | SLAB_TYPESAFE_BY_RCU, | |
1271 | NULL); | |
1272 | if (!subflow_ops->slab) | |
1273 | return -ENOMEM; | |
1274 | ||
79c0949e PK |
1275 | subflow_ops->destructor = subflow_req_destructor; |
1276 | ||
cec37a6e PK |
1277 | return 0; |
1278 | } | |
1279 | ||
d39dceca | 1280 | void __init mptcp_subflow_init(void) |
2303f994 | 1281 | { |
cec37a6e PK |
1282 | subflow_request_sock_ops = tcp_request_sock_ops; |
1283 | if (subflow_ops_init(&subflow_request_sock_ops) != 0) | |
1284 | panic("MPTCP: failed to init subflow request sock ops\n"); | |
1285 | ||
1286 | subflow_request_sock_ipv4_ops = tcp_request_sock_ipv4_ops; | |
1287 | subflow_request_sock_ipv4_ops.init_req = subflow_v4_init_req; | |
1288 | ||
1289 | subflow_specific = ipv4_specific; | |
1290 | subflow_specific.conn_request = subflow_v4_conn_request; | |
1291 | subflow_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1292 | subflow_specific.sk_rx_dst_set = subflow_finish_connect; | |
1293 | ||
1294 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1295 | subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; | |
1296 | subflow_request_sock_ipv6_ops.init_req = subflow_v6_init_req; | |
1297 | ||
1298 | subflow_v6_specific = ipv6_specific; | |
1299 | subflow_v6_specific.conn_request = subflow_v6_conn_request; | |
1300 | subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock; | |
1301 | subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect; | |
1302 | ||
1303 | subflow_v6m_specific = subflow_v6_specific; | |
1304 | subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit; | |
1305 | subflow_v6m_specific.send_check = ipv4_specific.send_check; | |
1306 | subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; | |
1307 | subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; | |
1308 | subflow_v6m_specific.net_frag_header_len = 0; | |
1309 | #endif | |
1310 | ||
5147dfb5 DC |
1311 | mptcp_diag_subflow_init(&subflow_ulp_ops); |
1312 | ||
2303f994 PK |
1313 | if (tcp_register_ulp(&subflow_ulp_ops) != 0) |
1314 | panic("MPTCP: failed to register subflows to ULP\n"); | |
1315 | } |