Commit | Line | Data |
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f870fa0b MM |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Multipath TCP | |
3 | * | |
4 | * Copyright (c) 2017 - 2019, Intel Corporation. | |
5 | */ | |
6 | ||
7 | #define pr_fmt(fmt) "MPTCP: " fmt | |
8 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/netdevice.h> | |
7a6a6cbc PA |
12 | #include <linux/sched/signal.h> |
13 | #include <linux/atomic.h> | |
f870fa0b MM |
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> | |
cf7da0d6 PK |
19 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
20 | #include <net/transp_v6.h> | |
21 | #endif | |
f870fa0b MM |
22 | #include <net/mptcp.h> |
23 | #include "protocol.h" | |
24 | ||
2303f994 PK |
25 | #define MPTCP_SAME_STATE TCP_MAX_STATES |
26 | ||
b0519de8 FW |
27 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
28 | struct mptcp6_sock { | |
29 | struct mptcp_sock msk; | |
30 | struct ipv6_pinfo np; | |
31 | }; | |
32 | #endif | |
33 | ||
6771bfd9 FW |
34 | struct mptcp_skb_cb { |
35 | u32 offset; | |
36 | }; | |
37 | ||
38 | #define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0])) | |
39 | ||
2303f994 PK |
40 | /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not |
41 | * completed yet or has failed, return the subflow socket. | |
42 | * Otherwise return NULL. | |
43 | */ | |
44 | static struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) | |
45 | { | |
d22f4988 | 46 | if (!msk->subflow || READ_ONCE(msk->can_ack)) |
2303f994 PK |
47 | return NULL; |
48 | ||
49 | return msk->subflow; | |
50 | } | |
51 | ||
8ab183de PA |
52 | static bool __mptcp_needs_tcp_fallback(const struct mptcp_sock *msk) |
53 | { | |
54 | return msk->first && !sk_is_mptcp(msk->first); | |
55 | } | |
56 | ||
8ab183de | 57 | static struct socket *__mptcp_tcp_fallback(struct mptcp_sock *msk) |
cec37a6e | 58 | { |
cec37a6e PK |
59 | sock_owned_by_me((const struct sock *)msk); |
60 | ||
8ab183de | 61 | if (likely(!__mptcp_needs_tcp_fallback(msk))) |
cec37a6e PK |
62 | return NULL; |
63 | ||
8ab183de | 64 | if (msk->subflow) { |
2c22c06c FW |
65 | release_sock((struct sock *)msk); |
66 | return msk->subflow; | |
8ab183de PA |
67 | } |
68 | ||
2c22c06c | 69 | return NULL; |
cec37a6e PK |
70 | } |
71 | ||
2303f994 PK |
72 | static bool __mptcp_can_create_subflow(const struct mptcp_sock *msk) |
73 | { | |
8ab183de | 74 | return !msk->first; |
2303f994 PK |
75 | } |
76 | ||
77 | static struct socket *__mptcp_socket_create(struct mptcp_sock *msk, int state) | |
78 | { | |
79 | struct mptcp_subflow_context *subflow; | |
80 | struct sock *sk = (struct sock *)msk; | |
81 | struct socket *ssock; | |
82 | int err; | |
83 | ||
84 | ssock = __mptcp_nmpc_socket(msk); | |
85 | if (ssock) | |
86 | goto set_state; | |
87 | ||
88 | if (!__mptcp_can_create_subflow(msk)) | |
89 | return ERR_PTR(-EINVAL); | |
90 | ||
91 | err = mptcp_subflow_create_socket(sk, &ssock); | |
92 | if (err) | |
93 | return ERR_PTR(err); | |
94 | ||
8ab183de | 95 | msk->first = ssock->sk; |
2303f994 PK |
96 | msk->subflow = ssock; |
97 | subflow = mptcp_subflow_ctx(ssock->sk); | |
cec37a6e | 98 | list_add(&subflow->node, &msk->conn_list); |
2303f994 PK |
99 | subflow->request_mptcp = 1; |
100 | ||
101 | set_state: | |
102 | if (state != MPTCP_SAME_STATE) | |
103 | inet_sk_state_store(sk, state); | |
104 | return ssock; | |
105 | } | |
106 | ||
cec37a6e PK |
107 | static struct sock *mptcp_subflow_get(const struct mptcp_sock *msk) |
108 | { | |
109 | struct mptcp_subflow_context *subflow; | |
110 | ||
111 | sock_owned_by_me((const struct sock *)msk); | |
112 | ||
113 | mptcp_for_each_subflow(msk, subflow) { | |
114 | return mptcp_subflow_tcp_sock(subflow); | |
115 | } | |
116 | ||
117 | return NULL; | |
118 | } | |
119 | ||
6771bfd9 FW |
120 | static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, |
121 | struct sk_buff *skb, | |
122 | unsigned int offset, size_t copy_len) | |
123 | { | |
124 | struct sock *sk = (struct sock *)msk; | |
125 | ||
126 | __skb_unlink(skb, &ssk->sk_receive_queue); | |
600911ff | 127 | skb_set_owner_r(skb, sk); |
6771bfd9 FW |
128 | __skb_queue_tail(&sk->sk_receive_queue, skb); |
129 | ||
130 | msk->ack_seq += copy_len; | |
131 | MPTCP_SKB_CB(skb)->offset = offset; | |
132 | } | |
133 | ||
134 | static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, | |
135 | struct sock *ssk, | |
136 | unsigned int *bytes) | |
137 | { | |
138 | struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); | |
600911ff | 139 | struct sock *sk = (struct sock *)msk; |
6771bfd9 FW |
140 | unsigned int moved = 0; |
141 | bool more_data_avail; | |
142 | struct tcp_sock *tp; | |
143 | bool done = false; | |
600911ff | 144 | |
ec33916d FW |
145 | if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { |
146 | int rcvbuf = max(ssk->sk_rcvbuf, sk->sk_rcvbuf); | |
147 | ||
148 | if (rcvbuf > sk->sk_rcvbuf) | |
149 | sk->sk_rcvbuf = rcvbuf; | |
150 | } | |
6771bfd9 FW |
151 | |
152 | tp = tcp_sk(ssk); | |
153 | do { | |
154 | u32 map_remaining, offset; | |
155 | u32 seq = tp->copied_seq; | |
156 | struct sk_buff *skb; | |
157 | bool fin; | |
158 | ||
159 | /* try to move as much data as available */ | |
160 | map_remaining = subflow->map_data_len - | |
161 | mptcp_subflow_get_map_offset(subflow); | |
162 | ||
163 | skb = skb_peek(&ssk->sk_receive_queue); | |
164 | if (!skb) | |
165 | break; | |
166 | ||
167 | offset = seq - TCP_SKB_CB(skb)->seq; | |
168 | fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; | |
169 | if (fin) { | |
170 | done = true; | |
171 | seq++; | |
172 | } | |
173 | ||
174 | if (offset < skb->len) { | |
175 | size_t len = skb->len - offset; | |
176 | ||
177 | if (tp->urg_data) | |
178 | done = true; | |
179 | ||
180 | __mptcp_move_skb(msk, ssk, skb, offset, len); | |
181 | seq += len; | |
182 | moved += len; | |
183 | ||
184 | if (WARN_ON_ONCE(map_remaining < len)) | |
185 | break; | |
186 | } else { | |
187 | WARN_ON_ONCE(!fin); | |
188 | sk_eat_skb(ssk, skb); | |
189 | done = true; | |
190 | } | |
191 | ||
192 | WRITE_ONCE(tp->copied_seq, seq); | |
193 | more_data_avail = mptcp_subflow_data_available(ssk); | |
600911ff FW |
194 | |
195 | if (atomic_read(&sk->sk_rmem_alloc) > READ_ONCE(sk->sk_rcvbuf)) { | |
196 | done = true; | |
197 | break; | |
198 | } | |
6771bfd9 FW |
199 | } while (more_data_avail); |
200 | ||
201 | *bytes = moved; | |
202 | ||
203 | return done; | |
204 | } | |
205 | ||
2e52213c FW |
206 | /* In most cases we will be able to lock the mptcp socket. If its already |
207 | * owned, we need to defer to the work queue to avoid ABBA deadlock. | |
208 | */ | |
209 | static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) | |
210 | { | |
211 | struct sock *sk = (struct sock *)msk; | |
212 | unsigned int moved = 0; | |
213 | ||
214 | if (READ_ONCE(sk->sk_lock.owned)) | |
215 | return false; | |
216 | ||
217 | if (unlikely(!spin_trylock_bh(&sk->sk_lock.slock))) | |
218 | return false; | |
219 | ||
220 | /* must re-check after taking the lock */ | |
221 | if (!READ_ONCE(sk->sk_lock.owned)) | |
222 | __mptcp_move_skbs_from_subflow(msk, ssk, &moved); | |
223 | ||
224 | spin_unlock_bh(&sk->sk_lock.slock); | |
225 | ||
226 | return moved > 0; | |
227 | } | |
228 | ||
229 | void mptcp_data_ready(struct sock *sk, struct sock *ssk) | |
101f6f85 FW |
230 | { |
231 | struct mptcp_sock *msk = mptcp_sk(sk); | |
232 | ||
233 | set_bit(MPTCP_DATA_READY, &msk->flags); | |
6771bfd9 | 234 | |
2e52213c FW |
235 | if (atomic_read(&sk->sk_rmem_alloc) < READ_ONCE(sk->sk_rcvbuf) && |
236 | move_skbs_to_msk(msk, ssk)) | |
237 | goto wake; | |
238 | ||
600911ff FW |
239 | /* don't schedule if mptcp sk is (still) over limit */ |
240 | if (atomic_read(&sk->sk_rmem_alloc) > READ_ONCE(sk->sk_rcvbuf)) | |
241 | goto wake; | |
242 | ||
14c441b5 PA |
243 | /* mptcp socket is owned, release_cb should retry */ |
244 | if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, | |
245 | &sk->sk_tsq_flags)) { | |
246 | sock_hold(sk); | |
6771bfd9 | 247 | |
14c441b5 PA |
248 | /* need to try again, its possible release_cb() has already |
249 | * been called after the test_and_set_bit() above. | |
250 | */ | |
251 | move_skbs_to_msk(msk, ssk); | |
252 | } | |
600911ff | 253 | wake: |
101f6f85 FW |
254 | sk->sk_data_ready(sk); |
255 | } | |
256 | ||
6d0060f6 MM |
257 | static bool mptcp_ext_cache_refill(struct mptcp_sock *msk) |
258 | { | |
259 | if (!msk->cached_ext) | |
260 | msk->cached_ext = __skb_ext_alloc(); | |
261 | ||
262 | return !!msk->cached_ext; | |
263 | } | |
264 | ||
7a6a6cbc PA |
265 | static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk) |
266 | { | |
267 | struct mptcp_subflow_context *subflow; | |
268 | struct sock *sk = (struct sock *)msk; | |
269 | ||
270 | sock_owned_by_me(sk); | |
271 | ||
272 | mptcp_for_each_subflow(msk, subflow) { | |
273 | if (subflow->data_avail) | |
274 | return mptcp_subflow_tcp_sock(subflow); | |
275 | } | |
276 | ||
277 | return NULL; | |
278 | } | |
279 | ||
57040755 PA |
280 | static inline bool mptcp_skb_can_collapse_to(const struct mptcp_sock *msk, |
281 | const struct sk_buff *skb, | |
282 | const struct mptcp_ext *mpext) | |
283 | { | |
284 | if (!tcp_skb_can_collapse_to(skb)) | |
285 | return false; | |
286 | ||
287 | /* can collapse only if MPTCP level sequence is in order */ | |
288 | return mpext && mpext->data_seq + mpext->data_len == msk->write_seq; | |
289 | } | |
290 | ||
6d0060f6 | 291 | static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, |
57040755 PA |
292 | struct msghdr *msg, long *timeo, int *pmss_now, |
293 | int *ps_goal) | |
6d0060f6 | 294 | { |
57040755 | 295 | int mss_now, avail_size, size_goal, ret; |
6d0060f6 MM |
296 | struct mptcp_sock *msk = mptcp_sk(sk); |
297 | struct mptcp_ext *mpext = NULL; | |
57040755 PA |
298 | struct sk_buff *skb, *tail; |
299 | bool can_collapse = false; | |
6d0060f6 | 300 | struct page_frag *pfrag; |
6d0060f6 MM |
301 | size_t psize; |
302 | ||
303 | /* use the mptcp page cache so that we can easily move the data | |
304 | * from one substream to another, but do per subflow memory accounting | |
305 | */ | |
306 | pfrag = sk_page_frag(sk); | |
307 | while (!sk_page_frag_refill(ssk, pfrag) || | |
308 | !mptcp_ext_cache_refill(msk)) { | |
309 | ret = sk_stream_wait_memory(ssk, timeo); | |
310 | if (ret) | |
311 | return ret; | |
8ab183de PA |
312 | if (unlikely(__mptcp_needs_tcp_fallback(msk))) |
313 | return 0; | |
6d0060f6 MM |
314 | } |
315 | ||
316 | /* compute copy limit */ | |
317 | mss_now = tcp_send_mss(ssk, &size_goal, msg->msg_flags); | |
57040755 PA |
318 | *pmss_now = mss_now; |
319 | *ps_goal = size_goal; | |
320 | avail_size = size_goal; | |
321 | skb = tcp_write_queue_tail(ssk); | |
322 | if (skb) { | |
323 | mpext = skb_ext_find(skb, SKB_EXT_MPTCP); | |
324 | ||
325 | /* Limit the write to the size available in the | |
326 | * current skb, if any, so that we create at most a new skb. | |
327 | * Explicitly tells TCP internals to avoid collapsing on later | |
328 | * queue management operation, to avoid breaking the ext <-> | |
329 | * SSN association set here | |
330 | */ | |
331 | can_collapse = (size_goal - skb->len > 0) && | |
332 | mptcp_skb_can_collapse_to(msk, skb, mpext); | |
333 | if (!can_collapse) | |
334 | TCP_SKB_CB(skb)->eor = 1; | |
335 | else | |
336 | avail_size = size_goal - skb->len; | |
337 | } | |
338 | psize = min_t(size_t, pfrag->size - pfrag->offset, avail_size); | |
6d0060f6 | 339 | |
57040755 | 340 | /* Copy to page */ |
6d0060f6 MM |
341 | pr_debug("left=%zu", msg_data_left(msg)); |
342 | psize = copy_page_from_iter(pfrag->page, pfrag->offset, | |
343 | min_t(size_t, msg_data_left(msg), psize), | |
344 | &msg->msg_iter); | |
345 | pr_debug("left=%zu", msg_data_left(msg)); | |
346 | if (!psize) | |
347 | return -EINVAL; | |
348 | ||
57040755 PA |
349 | /* tell the TCP stack to delay the push so that we can safely |
350 | * access the skb after the sendpages call | |
6d0060f6 | 351 | */ |
6d0060f6 MM |
352 | ret = do_tcp_sendpages(ssk, pfrag->page, pfrag->offset, psize, |
353 | msg->msg_flags | MSG_SENDPAGE_NOTLAST); | |
354 | if (ret <= 0) | |
355 | return ret; | |
356 | if (unlikely(ret < psize)) | |
357 | iov_iter_revert(&msg->msg_iter, psize - ret); | |
358 | ||
57040755 PA |
359 | /* if the tail skb extension is still the cached one, collapsing |
360 | * really happened. Note: we can't check for 'same skb' as the sk_buff | |
361 | * hdr on tail can be transmitted, freed and re-allocated by the | |
362 | * do_tcp_sendpages() call | |
363 | */ | |
364 | tail = tcp_write_queue_tail(ssk); | |
365 | if (mpext && tail && mpext == skb_ext_find(tail, SKB_EXT_MPTCP)) { | |
366 | WARN_ON_ONCE(!can_collapse); | |
367 | mpext->data_len += ret; | |
368 | goto out; | |
369 | } | |
370 | ||
6d0060f6 MM |
371 | skb = tcp_write_queue_tail(ssk); |
372 | mpext = __skb_ext_set(skb, SKB_EXT_MPTCP, msk->cached_ext); | |
373 | msk->cached_ext = NULL; | |
374 | ||
375 | memset(mpext, 0, sizeof(*mpext)); | |
376 | mpext->data_seq = msk->write_seq; | |
377 | mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq; | |
378 | mpext->data_len = ret; | |
379 | mpext->use_map = 1; | |
380 | mpext->dsn64 = 1; | |
381 | ||
382 | pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d", | |
383 | mpext->data_seq, mpext->subflow_seq, mpext->data_len, | |
384 | mpext->dsn64); | |
385 | ||
57040755 | 386 | out: |
6d0060f6 MM |
387 | pfrag->offset += ret; |
388 | msk->write_seq += ret; | |
389 | mptcp_subflow_ctx(ssk)->rel_write_seq += ret; | |
390 | ||
6d0060f6 MM |
391 | return ret; |
392 | } | |
393 | ||
1891c4a0 FW |
394 | static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk) |
395 | { | |
396 | struct socket *sock; | |
397 | ||
398 | if (likely(sk_stream_is_writeable(ssk))) | |
399 | return; | |
400 | ||
401 | sock = READ_ONCE(ssk->sk_socket); | |
402 | ||
403 | if (sock) { | |
404 | clear_bit(MPTCP_SEND_SPACE, &msk->flags); | |
405 | smp_mb__after_atomic(); | |
406 | /* set NOSPACE only after clearing SEND_SPACE flag */ | |
407 | set_bit(SOCK_NOSPACE, &sock->flags); | |
408 | } | |
409 | } | |
410 | ||
f870fa0b MM |
411 | static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
412 | { | |
57040755 | 413 | int mss_now = 0, size_goal = 0, ret = 0; |
f870fa0b | 414 | struct mptcp_sock *msk = mptcp_sk(sk); |
cec37a6e | 415 | struct socket *ssock; |
6d0060f6 | 416 | size_t copied = 0; |
cec37a6e | 417 | struct sock *ssk; |
6d0060f6 | 418 | long timeo; |
f870fa0b MM |
419 | |
420 | if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) | |
421 | return -EOPNOTSUPP; | |
422 | ||
cec37a6e | 423 | lock_sock(sk); |
1954b860 MM |
424 | |
425 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
426 | ||
427 | if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { | |
428 | ret = sk_stream_wait_connect(sk, &timeo); | |
429 | if (ret) | |
430 | goto out; | |
431 | } | |
432 | ||
cec37a6e | 433 | ssock = __mptcp_tcp_fallback(msk); |
8ab183de PA |
434 | if (unlikely(ssock)) { |
435 | fallback: | |
cec37a6e PK |
436 | pr_debug("fallback passthrough"); |
437 | ret = sock_sendmsg(ssock, msg); | |
8ab183de | 438 | return ret >= 0 ? ret + copied : (copied ? copied : ret); |
cec37a6e PK |
439 | } |
440 | ||
441 | ssk = mptcp_subflow_get(msk); | |
442 | if (!ssk) { | |
443 | release_sock(sk); | |
444 | return -ENOTCONN; | |
445 | } | |
446 | ||
6d0060f6 | 447 | pr_debug("conn_list->subflow=%p", ssk); |
cec37a6e | 448 | |
6d0060f6 MM |
449 | lock_sock(ssk); |
450 | while (msg_data_left(msg)) { | |
57040755 PA |
451 | ret = mptcp_sendmsg_frag(sk, ssk, msg, &timeo, &mss_now, |
452 | &size_goal); | |
6d0060f6 MM |
453 | if (ret < 0) |
454 | break; | |
8ab183de PA |
455 | if (ret == 0 && unlikely(__mptcp_needs_tcp_fallback(msk))) { |
456 | release_sock(ssk); | |
457 | ssock = __mptcp_tcp_fallback(msk); | |
458 | goto fallback; | |
459 | } | |
6d0060f6 MM |
460 | |
461 | copied += ret; | |
462 | } | |
463 | ||
57040755 | 464 | if (copied) { |
6d0060f6 | 465 | ret = copied; |
57040755 PA |
466 | tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle, |
467 | size_goal); | |
468 | } | |
6d0060f6 | 469 | |
1891c4a0 | 470 | ssk_check_wmem(msk, ssk); |
6d0060f6 | 471 | release_sock(ssk); |
1954b860 | 472 | out: |
cec37a6e PK |
473 | release_sock(sk); |
474 | return ret; | |
f870fa0b MM |
475 | } |
476 | ||
7a6a6cbc PA |
477 | static void mptcp_wait_data(struct sock *sk, long *timeo) |
478 | { | |
479 | DEFINE_WAIT_FUNC(wait, woken_wake_function); | |
480 | struct mptcp_sock *msk = mptcp_sk(sk); | |
481 | ||
482 | add_wait_queue(sk_sleep(sk), &wait); | |
483 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); | |
484 | ||
485 | sk_wait_event(sk, timeo, | |
486 | test_and_clear_bit(MPTCP_DATA_READY, &msk->flags), &wait); | |
487 | ||
488 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); | |
489 | remove_wait_queue(sk_sleep(sk), &wait); | |
490 | } | |
491 | ||
6771bfd9 FW |
492 | static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, |
493 | struct msghdr *msg, | |
494 | size_t len) | |
495 | { | |
496 | struct sock *sk = (struct sock *)msk; | |
497 | struct sk_buff *skb; | |
498 | int copied = 0; | |
499 | ||
500 | while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { | |
501 | u32 offset = MPTCP_SKB_CB(skb)->offset; | |
502 | u32 data_len = skb->len - offset; | |
503 | u32 count = min_t(size_t, len - copied, data_len); | |
504 | int err; | |
505 | ||
506 | err = skb_copy_datagram_msg(skb, offset, msg, count); | |
507 | if (unlikely(err < 0)) { | |
508 | if (!copied) | |
509 | return err; | |
510 | break; | |
511 | } | |
512 | ||
513 | copied += count; | |
514 | ||
515 | if (count < data_len) { | |
516 | MPTCP_SKB_CB(skb)->offset += count; | |
517 | break; | |
518 | } | |
519 | ||
520 | __skb_unlink(skb, &sk->sk_receive_queue); | |
521 | __kfree_skb(skb); | |
522 | ||
523 | if (copied >= len) | |
524 | break; | |
525 | } | |
526 | ||
527 | return copied; | |
528 | } | |
529 | ||
530 | static bool __mptcp_move_skbs(struct mptcp_sock *msk) | |
531 | { | |
532 | unsigned int moved = 0; | |
533 | bool done; | |
534 | ||
535 | do { | |
536 | struct sock *ssk = mptcp_subflow_recv_lookup(msk); | |
537 | ||
538 | if (!ssk) | |
539 | break; | |
540 | ||
541 | lock_sock(ssk); | |
542 | done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); | |
543 | release_sock(ssk); | |
544 | } while (!done); | |
545 | ||
546 | return moved > 0; | |
547 | } | |
548 | ||
f870fa0b MM |
549 | static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
550 | int nonblock, int flags, int *addr_len) | |
551 | { | |
552 | struct mptcp_sock *msk = mptcp_sk(sk); | |
cec37a6e | 553 | struct socket *ssock; |
cec37a6e | 554 | int copied = 0; |
7a6a6cbc PA |
555 | int target; |
556 | long timeo; | |
f870fa0b MM |
557 | |
558 | if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) | |
559 | return -EOPNOTSUPP; | |
560 | ||
cec37a6e PK |
561 | lock_sock(sk); |
562 | ssock = __mptcp_tcp_fallback(msk); | |
8ab183de PA |
563 | if (unlikely(ssock)) { |
564 | fallback: | |
cec37a6e PK |
565 | pr_debug("fallback-read subflow=%p", |
566 | mptcp_subflow_ctx(ssock->sk)); | |
567 | copied = sock_recvmsg(ssock, msg, flags); | |
cec37a6e PK |
568 | return copied; |
569 | } | |
570 | ||
7a6a6cbc PA |
571 | timeo = sock_rcvtimeo(sk, nonblock); |
572 | ||
573 | len = min_t(size_t, len, INT_MAX); | |
574 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); | |
575 | ||
6771bfd9 | 576 | while (len > (size_t)copied) { |
7a6a6cbc PA |
577 | int bytes_read; |
578 | ||
6771bfd9 FW |
579 | bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied); |
580 | if (unlikely(bytes_read < 0)) { | |
581 | if (!copied) | |
582 | copied = bytes_read; | |
583 | goto out_err; | |
584 | } | |
7a6a6cbc | 585 | |
6771bfd9 | 586 | copied += bytes_read; |
7a6a6cbc | 587 | |
6771bfd9 FW |
588 | if (skb_queue_empty(&sk->sk_receive_queue) && |
589 | __mptcp_move_skbs(msk)) | |
590 | continue; | |
7a6a6cbc PA |
591 | |
592 | /* only the master socket status is relevant here. The exit | |
593 | * conditions mirror closely tcp_recvmsg() | |
594 | */ | |
595 | if (copied >= target) | |
596 | break; | |
597 | ||
598 | if (copied) { | |
599 | if (sk->sk_err || | |
600 | sk->sk_state == TCP_CLOSE || | |
601 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
602 | !timeo || | |
603 | signal_pending(current)) | |
604 | break; | |
605 | } else { | |
606 | if (sk->sk_err) { | |
607 | copied = sock_error(sk); | |
608 | break; | |
609 | } | |
610 | ||
611 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
612 | break; | |
613 | ||
614 | if (sk->sk_state == TCP_CLOSE) { | |
615 | copied = -ENOTCONN; | |
616 | break; | |
617 | } | |
618 | ||
619 | if (!timeo) { | |
620 | copied = -EAGAIN; | |
621 | break; | |
622 | } | |
623 | ||
624 | if (signal_pending(current)) { | |
625 | copied = sock_intr_errno(timeo); | |
626 | break; | |
627 | } | |
628 | } | |
629 | ||
630 | pr_debug("block timeout %ld", timeo); | |
7a6a6cbc | 631 | mptcp_wait_data(sk, &timeo); |
8ab183de PA |
632 | if (unlikely(__mptcp_tcp_fallback(msk))) |
633 | goto fallback; | |
cec37a6e PK |
634 | } |
635 | ||
6771bfd9 FW |
636 | if (skb_queue_empty(&sk->sk_receive_queue)) { |
637 | /* entire backlog drained, clear DATA_READY. */ | |
7a6a6cbc | 638 | clear_bit(MPTCP_DATA_READY, &msk->flags); |
cec37a6e | 639 | |
6771bfd9 FW |
640 | /* .. race-breaker: ssk might have gotten new data |
641 | * after last __mptcp_move_skbs() returned false. | |
7a6a6cbc | 642 | */ |
6771bfd9 | 643 | if (unlikely(__mptcp_move_skbs(msk))) |
7a6a6cbc | 644 | set_bit(MPTCP_DATA_READY, &msk->flags); |
6771bfd9 FW |
645 | } else if (unlikely(!test_bit(MPTCP_DATA_READY, &msk->flags))) { |
646 | /* data to read but mptcp_wait_data() cleared DATA_READY */ | |
647 | set_bit(MPTCP_DATA_READY, &msk->flags); | |
7a6a6cbc | 648 | } |
6771bfd9 | 649 | out_err: |
7a6a6cbc | 650 | release_sock(sk); |
cec37a6e PK |
651 | return copied; |
652 | } | |
653 | ||
654 | /* subflow sockets can be either outgoing (connect) or incoming | |
655 | * (accept). | |
656 | * | |
657 | * Outgoing subflows use in-kernel sockets. | |
658 | * Incoming subflows do not have their own 'struct socket' allocated, | |
659 | * so we need to use tcp_close() after detaching them from the mptcp | |
660 | * parent socket. | |
661 | */ | |
662 | static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, | |
663 | struct mptcp_subflow_context *subflow, | |
664 | long timeout) | |
665 | { | |
666 | struct socket *sock = READ_ONCE(ssk->sk_socket); | |
667 | ||
668 | list_del(&subflow->node); | |
669 | ||
670 | if (sock && sock != sk->sk_socket) { | |
671 | /* outgoing subflow */ | |
672 | sock_release(sock); | |
673 | } else { | |
674 | /* incoming subflow */ | |
675 | tcp_close(ssk, timeout); | |
676 | } | |
f870fa0b MM |
677 | } |
678 | ||
dc24f8b4 PA |
679 | static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) |
680 | { | |
681 | return 0; | |
682 | } | |
683 | ||
80992017 PA |
684 | static void mptcp_worker(struct work_struct *work) |
685 | { | |
686 | struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); | |
687 | struct sock *sk = &msk->sk.icsk_inet.sk; | |
688 | ||
689 | lock_sock(sk); | |
6771bfd9 | 690 | __mptcp_move_skbs(msk); |
80992017 PA |
691 | release_sock(sk); |
692 | sock_put(sk); | |
693 | } | |
694 | ||
784325e9 | 695 | static int __mptcp_init_sock(struct sock *sk) |
f870fa0b | 696 | { |
cec37a6e PK |
697 | struct mptcp_sock *msk = mptcp_sk(sk); |
698 | ||
699 | INIT_LIST_HEAD(&msk->conn_list); | |
1891c4a0 | 700 | __set_bit(MPTCP_SEND_SPACE, &msk->flags); |
80992017 | 701 | INIT_WORK(&msk->work, mptcp_worker); |
cec37a6e | 702 | |
8ab183de | 703 | msk->first = NULL; |
dc24f8b4 | 704 | inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss; |
8ab183de | 705 | |
f870fa0b MM |
706 | return 0; |
707 | } | |
708 | ||
784325e9 MB |
709 | static int mptcp_init_sock(struct sock *sk) |
710 | { | |
711 | if (!mptcp_is_enabled(sock_net(sk))) | |
712 | return -ENOPROTOOPT; | |
713 | ||
714 | return __mptcp_init_sock(sk); | |
715 | } | |
716 | ||
80992017 PA |
717 | static void mptcp_cancel_work(struct sock *sk) |
718 | { | |
719 | struct mptcp_sock *msk = mptcp_sk(sk); | |
720 | ||
721 | if (cancel_work_sync(&msk->work)) | |
722 | sock_put(sk); | |
723 | } | |
724 | ||
76c42a29 MM |
725 | static void mptcp_subflow_shutdown(struct sock *ssk, int how, |
726 | bool data_fin_tx_enable, u64 data_fin_tx_seq) | |
21498490 PK |
727 | { |
728 | lock_sock(ssk); | |
729 | ||
730 | switch (ssk->sk_state) { | |
731 | case TCP_LISTEN: | |
732 | if (!(how & RCV_SHUTDOWN)) | |
733 | break; | |
734 | /* fall through */ | |
735 | case TCP_SYN_SENT: | |
736 | tcp_disconnect(ssk, O_NONBLOCK); | |
737 | break; | |
738 | default: | |
76c42a29 MM |
739 | if (data_fin_tx_enable) { |
740 | struct mptcp_subflow_context *subflow; | |
741 | ||
742 | subflow = mptcp_subflow_ctx(ssk); | |
743 | subflow->data_fin_tx_seq = data_fin_tx_seq; | |
744 | subflow->data_fin_tx_enable = 1; | |
745 | } | |
746 | ||
21498490 PK |
747 | ssk->sk_shutdown |= how; |
748 | tcp_shutdown(ssk, how); | |
749 | break; | |
750 | } | |
751 | ||
752 | /* Wake up anyone sleeping in poll. */ | |
753 | ssk->sk_state_change(ssk); | |
754 | release_sock(ssk); | |
755 | } | |
756 | ||
8ab183de | 757 | /* Called with msk lock held, releases such lock before returning */ |
2c22c06c | 758 | static void mptcp_close(struct sock *sk, long timeout) |
f870fa0b | 759 | { |
cec37a6e | 760 | struct mptcp_subflow_context *subflow, *tmp; |
f870fa0b | 761 | struct mptcp_sock *msk = mptcp_sk(sk); |
b2c5b614 | 762 | LIST_HEAD(conn_list); |
76c42a29 | 763 | u64 data_fin_tx_seq; |
f870fa0b | 764 | |
2c22c06c FW |
765 | lock_sock(sk); |
766 | ||
79c0949e | 767 | mptcp_token_destroy(msk->token); |
f870fa0b MM |
768 | inet_sk_state_store(sk, TCP_CLOSE); |
769 | ||
b2c5b614 FW |
770 | list_splice_init(&msk->conn_list, &conn_list); |
771 | ||
76c42a29 MM |
772 | data_fin_tx_seq = msk->write_seq; |
773 | ||
b2c5b614 FW |
774 | release_sock(sk); |
775 | ||
776 | list_for_each_entry_safe(subflow, tmp, &conn_list, node) { | |
cec37a6e PK |
777 | struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
778 | ||
76c42a29 MM |
779 | subflow->data_fin_tx_seq = data_fin_tx_seq; |
780 | subflow->data_fin_tx_enable = 1; | |
cec37a6e | 781 | __mptcp_close_ssk(sk, ssk, subflow, timeout); |
f870fa0b MM |
782 | } |
783 | ||
80992017 PA |
784 | mptcp_cancel_work(sk); |
785 | ||
6771bfd9 FW |
786 | __skb_queue_purge(&sk->sk_receive_queue); |
787 | ||
cec37a6e | 788 | sk_common_release(sk); |
f870fa0b MM |
789 | } |
790 | ||
cf7da0d6 PK |
791 | static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) |
792 | { | |
793 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
794 | const struct ipv6_pinfo *ssk6 = inet6_sk(ssk); | |
795 | struct ipv6_pinfo *msk6 = inet6_sk(msk); | |
796 | ||
797 | msk->sk_v6_daddr = ssk->sk_v6_daddr; | |
798 | msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr; | |
799 | ||
800 | if (msk6 && ssk6) { | |
801 | msk6->saddr = ssk6->saddr; | |
802 | msk6->flow_label = ssk6->flow_label; | |
803 | } | |
804 | #endif | |
805 | ||
806 | inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num; | |
807 | inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport; | |
808 | inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport; | |
809 | inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr; | |
810 | inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr; | |
811 | inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr; | |
812 | } | |
813 | ||
b0519de8 FW |
814 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) |
815 | static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk) | |
816 | { | |
817 | unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo); | |
818 | ||
819 | return (struct ipv6_pinfo *)(((u8 *)sk) + offset); | |
820 | } | |
821 | #endif | |
822 | ||
58b09919 | 823 | struct sock *mptcp_sk_clone(const struct sock *sk, struct request_sock *req) |
b0519de8 | 824 | { |
58b09919 | 825 | struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); |
b0519de8 | 826 | struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC); |
58b09919 PA |
827 | struct mptcp_sock *msk; |
828 | u64 ack_seq; | |
b0519de8 FW |
829 | |
830 | if (!nsk) | |
831 | return NULL; | |
832 | ||
833 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
834 | if (nsk->sk_family == AF_INET6) | |
835 | inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk); | |
836 | #endif | |
837 | ||
58b09919 PA |
838 | __mptcp_init_sock(nsk); |
839 | ||
840 | msk = mptcp_sk(nsk); | |
841 | msk->local_key = subflow_req->local_key; | |
842 | msk->token = subflow_req->token; | |
843 | msk->subflow = NULL; | |
844 | ||
845 | if (unlikely(mptcp_token_new_accept(subflow_req->token, nsk))) { | |
846 | bh_unlock_sock(nsk); | |
847 | ||
848 | /* we can't call into mptcp_close() here - possible BH context | |
849 | * free the sock directly | |
850 | */ | |
851 | nsk->sk_prot->destroy(nsk); | |
852 | sk_free(nsk); | |
853 | return NULL; | |
854 | } | |
855 | ||
856 | msk->write_seq = subflow_req->idsn + 1; | |
857 | if (subflow_req->remote_key_valid) { | |
858 | msk->can_ack = true; | |
859 | msk->remote_key = subflow_req->remote_key; | |
860 | mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); | |
861 | ack_seq++; | |
862 | msk->ack_seq = ack_seq; | |
863 | } | |
7f20d5fc PA |
864 | |
865 | /* will be fully established after successful MPC subflow creation */ | |
866 | inet_sk_state_store(nsk, TCP_SYN_RECV); | |
58b09919 PA |
867 | bh_unlock_sock(nsk); |
868 | ||
869 | /* keep a single reference */ | |
870 | __sock_put(nsk); | |
b0519de8 FW |
871 | return nsk; |
872 | } | |
873 | ||
cf7da0d6 PK |
874 | static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, |
875 | bool kern) | |
876 | { | |
877 | struct mptcp_sock *msk = mptcp_sk(sk); | |
878 | struct socket *listener; | |
879 | struct sock *newsk; | |
880 | ||
881 | listener = __mptcp_nmpc_socket(msk); | |
882 | if (WARN_ON_ONCE(!listener)) { | |
883 | *err = -EINVAL; | |
884 | return NULL; | |
885 | } | |
886 | ||
887 | pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk)); | |
888 | newsk = inet_csk_accept(listener->sk, flags, err, kern); | |
889 | if (!newsk) | |
890 | return NULL; | |
891 | ||
892 | pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk)); | |
893 | ||
894 | if (sk_is_mptcp(newsk)) { | |
895 | struct mptcp_subflow_context *subflow; | |
896 | struct sock *new_mptcp_sock; | |
897 | struct sock *ssk = newsk; | |
898 | ||
899 | subflow = mptcp_subflow_ctx(newsk); | |
58b09919 | 900 | new_mptcp_sock = subflow->conn; |
cf7da0d6 | 901 | |
58b09919 PA |
902 | /* is_mptcp should be false if subflow->conn is missing, see |
903 | * subflow_syn_recv_sock() | |
904 | */ | |
905 | if (WARN_ON_ONCE(!new_mptcp_sock)) { | |
906 | tcp_sk(newsk)->is_mptcp = 0; | |
907 | return newsk; | |
cf7da0d6 PK |
908 | } |
909 | ||
58b09919 PA |
910 | /* acquire the 2nd reference for the owning socket */ |
911 | sock_hold(new_mptcp_sock); | |
cf7da0d6 | 912 | |
58b09919 PA |
913 | local_bh_disable(); |
914 | bh_lock_sock(new_mptcp_sock); | |
cf7da0d6 | 915 | msk = mptcp_sk(new_mptcp_sock); |
8ab183de | 916 | msk->first = newsk; |
cf7da0d6 PK |
917 | |
918 | newsk = new_mptcp_sock; | |
919 | mptcp_copy_inaddrs(newsk, ssk); | |
920 | list_add(&subflow->node, &msk->conn_list); | |
921 | ||
cf7da0d6 PK |
922 | bh_unlock_sock(new_mptcp_sock); |
923 | local_bh_enable(); | |
cf7da0d6 PK |
924 | } |
925 | ||
926 | return newsk; | |
927 | } | |
928 | ||
79c0949e PK |
929 | static void mptcp_destroy(struct sock *sk) |
930 | { | |
c9fd9c5f FW |
931 | struct mptcp_sock *msk = mptcp_sk(sk); |
932 | ||
933 | if (msk->cached_ext) | |
934 | __skb_ext_put(msk->cached_ext); | |
79c0949e PK |
935 | } |
936 | ||
717e79c8 | 937 | static int mptcp_setsockopt(struct sock *sk, int level, int optname, |
50e741bb | 938 | char __user *optval, unsigned int optlen) |
717e79c8 PK |
939 | { |
940 | struct mptcp_sock *msk = mptcp_sk(sk); | |
717e79c8 | 941 | struct socket *ssock; |
717e79c8 PK |
942 | |
943 | pr_debug("msk=%p", msk); | |
944 | ||
945 | /* @@ the meaning of setsockopt() when the socket is connected and | |
b6e4a1ae MM |
946 | * there are multiple subflows is not yet defined. It is up to the |
947 | * MPTCP-level socket to configure the subflows until the subflow | |
948 | * is in TCP fallback, when TCP socket options are passed through | |
949 | * to the one remaining subflow. | |
717e79c8 PK |
950 | */ |
951 | lock_sock(sk); | |
b6e4a1ae MM |
952 | ssock = __mptcp_tcp_fallback(msk); |
953 | if (ssock) | |
954 | return tcp_setsockopt(ssock->sk, level, optname, optval, | |
955 | optlen); | |
50e741bb | 956 | |
717e79c8 PK |
957 | release_sock(sk); |
958 | ||
b6e4a1ae | 959 | return -EOPNOTSUPP; |
717e79c8 PK |
960 | } |
961 | ||
962 | static int mptcp_getsockopt(struct sock *sk, int level, int optname, | |
50e741bb | 963 | char __user *optval, int __user *option) |
717e79c8 PK |
964 | { |
965 | struct mptcp_sock *msk = mptcp_sk(sk); | |
717e79c8 | 966 | struct socket *ssock; |
717e79c8 PK |
967 | |
968 | pr_debug("msk=%p", msk); | |
969 | ||
b6e4a1ae MM |
970 | /* @@ the meaning of setsockopt() when the socket is connected and |
971 | * there are multiple subflows is not yet defined. It is up to the | |
972 | * MPTCP-level socket to configure the subflows until the subflow | |
973 | * is in TCP fallback, when socket options are passed through | |
974 | * to the one remaining subflow. | |
717e79c8 PK |
975 | */ |
976 | lock_sock(sk); | |
b6e4a1ae MM |
977 | ssock = __mptcp_tcp_fallback(msk); |
978 | if (ssock) | |
979 | return tcp_getsockopt(ssock->sk, level, optname, optval, | |
980 | option); | |
50e741bb | 981 | |
717e79c8 PK |
982 | release_sock(sk); |
983 | ||
b6e4a1ae | 984 | return -EOPNOTSUPP; |
717e79c8 PK |
985 | } |
986 | ||
14c441b5 PA |
987 | #define MPTCP_DEFERRED_ALL TCPF_DELACK_TIMER_DEFERRED |
988 | ||
989 | /* this is very alike tcp_release_cb() but we must handle differently a | |
990 | * different set of events | |
991 | */ | |
992 | static void mptcp_release_cb(struct sock *sk) | |
993 | { | |
994 | unsigned long flags, nflags; | |
995 | ||
996 | do { | |
997 | flags = sk->sk_tsq_flags; | |
998 | if (!(flags & MPTCP_DEFERRED_ALL)) | |
999 | return; | |
1000 | nflags = flags & ~MPTCP_DEFERRED_ALL; | |
1001 | } while (cmpxchg(&sk->sk_tsq_flags, flags, nflags) != flags); | |
1002 | ||
1003 | if (flags & TCPF_DELACK_TIMER_DEFERRED) { | |
1004 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1005 | struct sock *ssk; | |
1006 | ||
1007 | ssk = mptcp_subflow_recv_lookup(msk); | |
1008 | if (!ssk || !schedule_work(&msk->work)) | |
1009 | __sock_put(sk); | |
1010 | } | |
1011 | } | |
1012 | ||
cec37a6e | 1013 | static int mptcp_get_port(struct sock *sk, unsigned short snum) |
f870fa0b MM |
1014 | { |
1015 | struct mptcp_sock *msk = mptcp_sk(sk); | |
cec37a6e | 1016 | struct socket *ssock; |
f870fa0b | 1017 | |
cec37a6e PK |
1018 | ssock = __mptcp_nmpc_socket(msk); |
1019 | pr_debug("msk=%p, subflow=%p", msk, ssock); | |
1020 | if (WARN_ON_ONCE(!ssock)) | |
1021 | return -EINVAL; | |
f870fa0b | 1022 | |
cec37a6e PK |
1023 | return inet_csk_get_port(ssock->sk, snum); |
1024 | } | |
f870fa0b | 1025 | |
cec37a6e PK |
1026 | void mptcp_finish_connect(struct sock *ssk) |
1027 | { | |
1028 | struct mptcp_subflow_context *subflow; | |
1029 | struct mptcp_sock *msk; | |
1030 | struct sock *sk; | |
6d0060f6 | 1031 | u64 ack_seq; |
f870fa0b | 1032 | |
cec37a6e | 1033 | subflow = mptcp_subflow_ctx(ssk); |
f870fa0b | 1034 | |
cec37a6e PK |
1035 | if (!subflow->mp_capable) |
1036 | return; | |
1037 | ||
1038 | sk = subflow->conn; | |
1039 | msk = mptcp_sk(sk); | |
1040 | ||
648ef4b8 MM |
1041 | pr_debug("msk=%p, token=%u", sk, subflow->token); |
1042 | ||
6d0060f6 MM |
1043 | mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq); |
1044 | ack_seq++; | |
648ef4b8 MM |
1045 | subflow->map_seq = ack_seq; |
1046 | subflow->map_subflow_seq = 1; | |
6d0060f6 MM |
1047 | subflow->rel_write_seq = 1; |
1048 | ||
cec37a6e PK |
1049 | /* the socket is not connected yet, no msk/subflow ops can access/race |
1050 | * accessing the field below | |
1051 | */ | |
1052 | WRITE_ONCE(msk->remote_key, subflow->remote_key); | |
1053 | WRITE_ONCE(msk->local_key, subflow->local_key); | |
79c0949e | 1054 | WRITE_ONCE(msk->token, subflow->token); |
6d0060f6 MM |
1055 | WRITE_ONCE(msk->write_seq, subflow->idsn + 1); |
1056 | WRITE_ONCE(msk->ack_seq, ack_seq); | |
d22f4988 | 1057 | WRITE_ONCE(msk->can_ack, 1); |
f870fa0b MM |
1058 | } |
1059 | ||
cf7da0d6 PK |
1060 | static void mptcp_sock_graft(struct sock *sk, struct socket *parent) |
1061 | { | |
1062 | write_lock_bh(&sk->sk_callback_lock); | |
1063 | rcu_assign_pointer(sk->sk_wq, &parent->wq); | |
1064 | sk_set_socket(sk, parent); | |
1065 | sk->sk_uid = SOCK_INODE(parent)->i_uid; | |
1066 | write_unlock_bh(&sk->sk_callback_lock); | |
1067 | } | |
1068 | ||
1891c4a0 FW |
1069 | static bool mptcp_memory_free(const struct sock *sk, int wake) |
1070 | { | |
1071 | struct mptcp_sock *msk = mptcp_sk(sk); | |
1072 | ||
1073 | return wake ? test_bit(MPTCP_SEND_SPACE, &msk->flags) : true; | |
1074 | } | |
1075 | ||
f870fa0b MM |
1076 | static struct proto mptcp_prot = { |
1077 | .name = "MPTCP", | |
1078 | .owner = THIS_MODULE, | |
1079 | .init = mptcp_init_sock, | |
1080 | .close = mptcp_close, | |
cf7da0d6 | 1081 | .accept = mptcp_accept, |
717e79c8 PK |
1082 | .setsockopt = mptcp_setsockopt, |
1083 | .getsockopt = mptcp_getsockopt, | |
f870fa0b | 1084 | .shutdown = tcp_shutdown, |
79c0949e | 1085 | .destroy = mptcp_destroy, |
f870fa0b MM |
1086 | .sendmsg = mptcp_sendmsg, |
1087 | .recvmsg = mptcp_recvmsg, | |
14c441b5 | 1088 | .release_cb = mptcp_release_cb, |
f870fa0b MM |
1089 | .hash = inet_hash, |
1090 | .unhash = inet_unhash, | |
cec37a6e | 1091 | .get_port = mptcp_get_port, |
1891c4a0 | 1092 | .stream_memory_free = mptcp_memory_free, |
f870fa0b MM |
1093 | .obj_size = sizeof(struct mptcp_sock), |
1094 | .no_autobind = true, | |
1095 | }; | |
1096 | ||
2303f994 PK |
1097 | static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
1098 | { | |
1099 | struct mptcp_sock *msk = mptcp_sk(sock->sk); | |
1100 | struct socket *ssock; | |
cf7da0d6 | 1101 | int err; |
2303f994 PK |
1102 | |
1103 | lock_sock(sock->sk); | |
1104 | ssock = __mptcp_socket_create(msk, MPTCP_SAME_STATE); | |
1105 | if (IS_ERR(ssock)) { | |
1106 | err = PTR_ERR(ssock); | |
1107 | goto unlock; | |
1108 | } | |
1109 | ||
1110 | err = ssock->ops->bind(ssock, uaddr, addr_len); | |
cf7da0d6 PK |
1111 | if (!err) |
1112 | mptcp_copy_inaddrs(sock->sk, ssock->sk); | |
2303f994 PK |
1113 | |
1114 | unlock: | |
1115 | release_sock(sock->sk); | |
1116 | return err; | |
1117 | } | |
1118 | ||
1119 | static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, | |
1120 | int addr_len, int flags) | |
1121 | { | |
1122 | struct mptcp_sock *msk = mptcp_sk(sock->sk); | |
1123 | struct socket *ssock; | |
1124 | int err; | |
1125 | ||
1126 | lock_sock(sock->sk); | |
1127 | ssock = __mptcp_socket_create(msk, TCP_SYN_SENT); | |
1128 | if (IS_ERR(ssock)) { | |
1129 | err = PTR_ERR(ssock); | |
1130 | goto unlock; | |
1131 | } | |
1132 | ||
cf7da0d6 PK |
1133 | #ifdef CONFIG_TCP_MD5SIG |
1134 | /* no MPTCP if MD5SIG is enabled on this socket or we may run out of | |
1135 | * TCP option space. | |
1136 | */ | |
1137 | if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) | |
1138 | mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0; | |
1139 | #endif | |
1140 | ||
2303f994 PK |
1141 | err = ssock->ops->connect(ssock, uaddr, addr_len, flags); |
1142 | inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); | |
cf7da0d6 | 1143 | mptcp_copy_inaddrs(sock->sk, ssock->sk); |
2303f994 PK |
1144 | |
1145 | unlock: | |
1146 | release_sock(sock->sk); | |
1147 | return err; | |
1148 | } | |
1149 | ||
cf7da0d6 PK |
1150 | static int mptcp_v4_getname(struct socket *sock, struct sockaddr *uaddr, |
1151 | int peer) | |
1152 | { | |
1153 | if (sock->sk->sk_prot == &tcp_prot) { | |
1154 | /* we are being invoked from __sys_accept4, after | |
1155 | * mptcp_accept() has just accepted a non-mp-capable | |
1156 | * flow: sk is a tcp_sk, not an mptcp one. | |
1157 | * | |
1158 | * Hand the socket over to tcp so all further socket ops | |
1159 | * bypass mptcp. | |
1160 | */ | |
1161 | sock->ops = &inet_stream_ops; | |
1162 | } | |
1163 | ||
1164 | return inet_getname(sock, uaddr, peer); | |
1165 | } | |
1166 | ||
1167 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1168 | static int mptcp_v6_getname(struct socket *sock, struct sockaddr *uaddr, | |
1169 | int peer) | |
1170 | { | |
1171 | if (sock->sk->sk_prot == &tcpv6_prot) { | |
1172 | /* we are being invoked from __sys_accept4 after | |
1173 | * mptcp_accept() has accepted a non-mp-capable | |
1174 | * subflow: sk is a tcp_sk, not mptcp. | |
1175 | * | |
1176 | * Hand the socket over to tcp so all further | |
1177 | * socket ops bypass mptcp. | |
1178 | */ | |
1179 | sock->ops = &inet6_stream_ops; | |
1180 | } | |
1181 | ||
1182 | return inet6_getname(sock, uaddr, peer); | |
1183 | } | |
1184 | #endif | |
1185 | ||
1186 | static int mptcp_listen(struct socket *sock, int backlog) | |
1187 | { | |
1188 | struct mptcp_sock *msk = mptcp_sk(sock->sk); | |
1189 | struct socket *ssock; | |
1190 | int err; | |
1191 | ||
1192 | pr_debug("msk=%p", msk); | |
1193 | ||
1194 | lock_sock(sock->sk); | |
1195 | ssock = __mptcp_socket_create(msk, TCP_LISTEN); | |
1196 | if (IS_ERR(ssock)) { | |
1197 | err = PTR_ERR(ssock); | |
1198 | goto unlock; | |
1199 | } | |
1200 | ||
1201 | err = ssock->ops->listen(ssock, backlog); | |
1202 | inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); | |
1203 | if (!err) | |
1204 | mptcp_copy_inaddrs(sock->sk, ssock->sk); | |
1205 | ||
1206 | unlock: | |
1207 | release_sock(sock->sk); | |
1208 | return err; | |
1209 | } | |
1210 | ||
1211 | static bool is_tcp_proto(const struct proto *p) | |
1212 | { | |
1213 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
1214 | return p == &tcp_prot || p == &tcpv6_prot; | |
1215 | #else | |
1216 | return p == &tcp_prot; | |
1217 | #endif | |
1218 | } | |
1219 | ||
1220 | static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, | |
1221 | int flags, bool kern) | |
1222 | { | |
1223 | struct mptcp_sock *msk = mptcp_sk(sock->sk); | |
1224 | struct socket *ssock; | |
1225 | int err; | |
1226 | ||
1227 | pr_debug("msk=%p", msk); | |
1228 | ||
1229 | lock_sock(sock->sk); | |
1230 | if (sock->sk->sk_state != TCP_LISTEN) | |
1231 | goto unlock_fail; | |
1232 | ||
1233 | ssock = __mptcp_nmpc_socket(msk); | |
1234 | if (!ssock) | |
1235 | goto unlock_fail; | |
1236 | ||
1237 | sock_hold(ssock->sk); | |
1238 | release_sock(sock->sk); | |
1239 | ||
1240 | err = ssock->ops->accept(sock, newsock, flags, kern); | |
1241 | if (err == 0 && !is_tcp_proto(newsock->sk->sk_prot)) { | |
1242 | struct mptcp_sock *msk = mptcp_sk(newsock->sk); | |
1243 | struct mptcp_subflow_context *subflow; | |
1244 | ||
1245 | /* set ssk->sk_socket of accept()ed flows to mptcp socket. | |
1246 | * This is needed so NOSPACE flag can be set from tcp stack. | |
1247 | */ | |
1248 | list_for_each_entry(subflow, &msk->conn_list, node) { | |
1249 | struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | |
1250 | ||
1251 | if (!ssk->sk_socket) | |
1252 | mptcp_sock_graft(ssk, newsock); | |
1253 | } | |
cf7da0d6 PK |
1254 | } |
1255 | ||
1256 | sock_put(ssock->sk); | |
1257 | return err; | |
1258 | ||
1259 | unlock_fail: | |
1260 | release_sock(sock->sk); | |
1261 | return -EINVAL; | |
1262 | } | |
1263 | ||
2303f994 PK |
1264 | static __poll_t mptcp_poll(struct file *file, struct socket *sock, |
1265 | struct poll_table_struct *wait) | |
1266 | { | |
1891c4a0 | 1267 | struct sock *sk = sock->sk; |
8ab183de | 1268 | struct mptcp_sock *msk; |
1891c4a0 | 1269 | struct socket *ssock; |
2303f994 PK |
1270 | __poll_t mask = 0; |
1271 | ||
1891c4a0 FW |
1272 | msk = mptcp_sk(sk); |
1273 | lock_sock(sk); | |
1274 | ssock = __mptcp_nmpc_socket(msk); | |
1275 | if (ssock) { | |
1276 | mask = ssock->ops->poll(file, ssock, wait); | |
1277 | release_sock(sk); | |
1278 | return mask; | |
1279 | } | |
1280 | ||
1281 | release_sock(sk); | |
1282 | sock_poll_wait(file, sock, wait); | |
1283 | lock_sock(sk); | |
8ab183de PA |
1284 | ssock = __mptcp_tcp_fallback(msk); |
1285 | if (unlikely(ssock)) | |
1286 | return ssock->ops->poll(file, ssock, NULL); | |
1891c4a0 FW |
1287 | |
1288 | if (test_bit(MPTCP_DATA_READY, &msk->flags)) | |
1289 | mask = EPOLLIN | EPOLLRDNORM; | |
1290 | if (sk_stream_is_writeable(sk) && | |
1291 | test_bit(MPTCP_SEND_SPACE, &msk->flags)) | |
1292 | mask |= EPOLLOUT | EPOLLWRNORM; | |
1293 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
1294 | mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; | |
1295 | ||
1296 | release_sock(sk); | |
1297 | ||
2303f994 PK |
1298 | return mask; |
1299 | } | |
1300 | ||
21498490 PK |
1301 | static int mptcp_shutdown(struct socket *sock, int how) |
1302 | { | |
1303 | struct mptcp_sock *msk = mptcp_sk(sock->sk); | |
1304 | struct mptcp_subflow_context *subflow; | |
1305 | int ret = 0; | |
1306 | ||
1307 | pr_debug("sk=%p, how=%d", msk, how); | |
1308 | ||
1309 | lock_sock(sock->sk); | |
1310 | ||
1311 | if (how == SHUT_WR || how == SHUT_RDWR) | |
1312 | inet_sk_state_store(sock->sk, TCP_FIN_WAIT1); | |
1313 | ||
1314 | how++; | |
1315 | ||
1316 | if ((how & ~SHUTDOWN_MASK) || !how) { | |
1317 | ret = -EINVAL; | |
1318 | goto out_unlock; | |
1319 | } | |
1320 | ||
1321 | if (sock->state == SS_CONNECTING) { | |
1322 | if ((1 << sock->sk->sk_state) & | |
1323 | (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) | |
1324 | sock->state = SS_DISCONNECTING; | |
1325 | else | |
1326 | sock->state = SS_CONNECTED; | |
1327 | } | |
1328 | ||
1329 | mptcp_for_each_subflow(msk, subflow) { | |
1330 | struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); | |
1331 | ||
76c42a29 | 1332 | mptcp_subflow_shutdown(tcp_sk, how, 1, msk->write_seq); |
21498490 PK |
1333 | } |
1334 | ||
1335 | out_unlock: | |
1336 | release_sock(sock->sk); | |
1337 | ||
1338 | return ret; | |
1339 | } | |
1340 | ||
e42f1ac6 FW |
1341 | static const struct proto_ops mptcp_stream_ops = { |
1342 | .family = PF_INET, | |
1343 | .owner = THIS_MODULE, | |
1344 | .release = inet_release, | |
1345 | .bind = mptcp_bind, | |
1346 | .connect = mptcp_stream_connect, | |
1347 | .socketpair = sock_no_socketpair, | |
1348 | .accept = mptcp_stream_accept, | |
1349 | .getname = mptcp_v4_getname, | |
1350 | .poll = mptcp_poll, | |
1351 | .ioctl = inet_ioctl, | |
1352 | .gettstamp = sock_gettstamp, | |
1353 | .listen = mptcp_listen, | |
1354 | .shutdown = mptcp_shutdown, | |
1355 | .setsockopt = sock_common_setsockopt, | |
1356 | .getsockopt = sock_common_getsockopt, | |
1357 | .sendmsg = inet_sendmsg, | |
1358 | .recvmsg = inet_recvmsg, | |
1359 | .mmap = sock_no_mmap, | |
1360 | .sendpage = inet_sendpage, | |
1361 | #ifdef CONFIG_COMPAT | |
1362 | .compat_setsockopt = compat_sock_common_setsockopt, | |
1363 | .compat_getsockopt = compat_sock_common_getsockopt, | |
1364 | #endif | |
1365 | }; | |
2303f994 | 1366 | |
f870fa0b MM |
1367 | static struct inet_protosw mptcp_protosw = { |
1368 | .type = SOCK_STREAM, | |
1369 | .protocol = IPPROTO_MPTCP, | |
1370 | .prot = &mptcp_prot, | |
2303f994 PK |
1371 | .ops = &mptcp_stream_ops, |
1372 | .flags = INET_PROTOSW_ICSK, | |
f870fa0b MM |
1373 | }; |
1374 | ||
784325e9 | 1375 | void mptcp_proto_init(void) |
f870fa0b | 1376 | { |
2303f994 | 1377 | mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo; |
2303f994 PK |
1378 | |
1379 | mptcp_subflow_init(); | |
1380 | ||
f870fa0b MM |
1381 | if (proto_register(&mptcp_prot, 1) != 0) |
1382 | panic("Failed to register MPTCP proto.\n"); | |
1383 | ||
1384 | inet_register_protosw(&mptcp_protosw); | |
6771bfd9 FW |
1385 | |
1386 | BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, cb)); | |
f870fa0b MM |
1387 | } |
1388 | ||
1389 | #if IS_ENABLED(CONFIG_MPTCP_IPV6) | |
e42f1ac6 FW |
1390 | static const struct proto_ops mptcp_v6_stream_ops = { |
1391 | .family = PF_INET6, | |
1392 | .owner = THIS_MODULE, | |
1393 | .release = inet6_release, | |
1394 | .bind = mptcp_bind, | |
1395 | .connect = mptcp_stream_connect, | |
1396 | .socketpair = sock_no_socketpair, | |
1397 | .accept = mptcp_stream_accept, | |
1398 | .getname = mptcp_v6_getname, | |
1399 | .poll = mptcp_poll, | |
1400 | .ioctl = inet6_ioctl, | |
1401 | .gettstamp = sock_gettstamp, | |
1402 | .listen = mptcp_listen, | |
1403 | .shutdown = mptcp_shutdown, | |
1404 | .setsockopt = sock_common_setsockopt, | |
1405 | .getsockopt = sock_common_getsockopt, | |
1406 | .sendmsg = inet6_sendmsg, | |
1407 | .recvmsg = inet6_recvmsg, | |
1408 | .mmap = sock_no_mmap, | |
1409 | .sendpage = inet_sendpage, | |
1410 | #ifdef CONFIG_COMPAT | |
1411 | .compat_setsockopt = compat_sock_common_setsockopt, | |
1412 | .compat_getsockopt = compat_sock_common_getsockopt, | |
1413 | #endif | |
1414 | }; | |
1415 | ||
f870fa0b MM |
1416 | static struct proto mptcp_v6_prot; |
1417 | ||
79c0949e PK |
1418 | static void mptcp_v6_destroy(struct sock *sk) |
1419 | { | |
1420 | mptcp_destroy(sk); | |
1421 | inet6_destroy_sock(sk); | |
1422 | } | |
1423 | ||
f870fa0b MM |
1424 | static struct inet_protosw mptcp_v6_protosw = { |
1425 | .type = SOCK_STREAM, | |
1426 | .protocol = IPPROTO_MPTCP, | |
1427 | .prot = &mptcp_v6_prot, | |
2303f994 | 1428 | .ops = &mptcp_v6_stream_ops, |
f870fa0b MM |
1429 | .flags = INET_PROTOSW_ICSK, |
1430 | }; | |
1431 | ||
784325e9 | 1432 | int mptcp_proto_v6_init(void) |
f870fa0b MM |
1433 | { |
1434 | int err; | |
1435 | ||
1436 | mptcp_v6_prot = mptcp_prot; | |
1437 | strcpy(mptcp_v6_prot.name, "MPTCPv6"); | |
1438 | mptcp_v6_prot.slab = NULL; | |
79c0949e | 1439 | mptcp_v6_prot.destroy = mptcp_v6_destroy; |
b0519de8 | 1440 | mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock); |
f870fa0b MM |
1441 | |
1442 | err = proto_register(&mptcp_v6_prot, 1); | |
1443 | if (err) | |
1444 | return err; | |
1445 | ||
1446 | err = inet6_register_protosw(&mptcp_v6_protosw); | |
1447 | if (err) | |
1448 | proto_unregister(&mptcp_v6_prot); | |
1449 | ||
1450 | return err; | |
1451 | } | |
1452 | #endif |