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Commit | Line | Data |
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3f421baa ACM |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Support for INET connection oriented protocols. | |
7 | * | |
8 | * Authors: See the TCP sources | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or(at your option) any later version. | |
14 | */ | |
15 | ||
3f421baa ACM |
16 | #include <linux/module.h> |
17 | #include <linux/jhash.h> | |
18 | ||
19 | #include <net/inet_connection_sock.h> | |
20 | #include <net/inet_hashtables.h> | |
21 | #include <net/inet_timewait_sock.h> | |
22 | #include <net/ip.h> | |
23 | #include <net/route.h> | |
24 | #include <net/tcp_states.h> | |
a019d6fe | 25 | #include <net/xfrm.h> |
3f421baa ACM |
26 | |
27 | #ifdef INET_CSK_DEBUG | |
28 | const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n"; | |
29 | EXPORT_SYMBOL(inet_csk_timer_bug_msg); | |
30 | #endif | |
31 | ||
32 | /* | |
3c689b73 | 33 | * This struct holds the first and last local port number. |
3f421baa | 34 | */ |
3c689b73 | 35 | struct local_ports sysctl_local_ports __read_mostly = { |
c4dbe54e | 36 | .lock = __SEQLOCK_UNLOCKED(sysctl_local_ports.lock), |
3c689b73 ED |
37 | .range = { 32768, 61000 }, |
38 | }; | |
227b60f5 | 39 | |
e3826f1e AW |
40 | unsigned long *sysctl_local_reserved_ports; |
41 | EXPORT_SYMBOL(sysctl_local_reserved_ports); | |
42 | ||
227b60f5 SH |
43 | void inet_get_local_port_range(int *low, int *high) |
44 | { | |
95c96174 ED |
45 | unsigned int seq; |
46 | ||
227b60f5 | 47 | do { |
3c689b73 | 48 | seq = read_seqbegin(&sysctl_local_ports.lock); |
227b60f5 | 49 | |
3c689b73 ED |
50 | *low = sysctl_local_ports.range[0]; |
51 | *high = sysctl_local_ports.range[1]; | |
52 | } while (read_seqretry(&sysctl_local_ports.lock, seq)); | |
227b60f5 SH |
53 | } |
54 | EXPORT_SYMBOL(inet_get_local_port_range); | |
3f421baa | 55 | |
971af18b | 56 | int inet_csk_bind_conflict(const struct sock *sk, |
aacd9289 | 57 | const struct inet_bind_bucket *tb, bool relax) |
3f421baa | 58 | { |
3f421baa ACM |
59 | struct sock *sk2; |
60 | struct hlist_node *node; | |
61 | int reuse = sk->sk_reuse; | |
62 | ||
7477fd2e PE |
63 | /* |
64 | * Unlike other sk lookup places we do not check | |
65 | * for sk_net here, since _all_ the socks listed | |
66 | * in tb->owners list belong to the same net - the | |
67 | * one this bucket belongs to. | |
68 | */ | |
69 | ||
3f421baa ACM |
70 | sk_for_each_bound(sk2, node, &tb->owners) { |
71 | if (sk != sk2 && | |
72 | !inet_v6_ipv6only(sk2) && | |
73 | (!sk->sk_bound_dev_if || | |
74 | !sk2->sk_bound_dev_if || | |
75 | sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { | |
76 | if (!reuse || !sk2->sk_reuse || | |
3e8c806a | 77 | sk2->sk_state == TCP_LISTEN) { |
68835aba ED |
78 | const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); |
79 | if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) || | |
80 | sk2_rcv_saddr == sk_rcv_saddr(sk)) | |
3f421baa | 81 | break; |
8d238b25 | 82 | } |
aacd9289 AC |
83 | if (!relax && reuse && sk2->sk_reuse && |
84 | sk2->sk_state != TCP_LISTEN) { | |
85 | const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); | |
86 | ||
87 | if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) || | |
88 | sk2_rcv_saddr == sk_rcv_saddr(sk)) | |
89 | break; | |
90 | } | |
3f421baa ACM |
91 | } |
92 | } | |
93 | return node != NULL; | |
94 | } | |
971af18b ACM |
95 | EXPORT_SYMBOL_GPL(inet_csk_bind_conflict); |
96 | ||
3f421baa ACM |
97 | /* Obtain a reference to a local port for the given sock, |
98 | * if snum is zero it means select any available local port. | |
99 | */ | |
ab1e0a13 | 100 | int inet_csk_get_port(struct sock *sk, unsigned short snum) |
3f421baa | 101 | { |
39d8cda7 | 102 | struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; |
3f421baa ACM |
103 | struct inet_bind_hashbucket *head; |
104 | struct hlist_node *node; | |
105 | struct inet_bind_bucket *tb; | |
a9d8f911 | 106 | int ret, attempts = 5; |
3b1e0a65 | 107 | struct net *net = sock_net(sk); |
a9d8f911 | 108 | int smallest_size = -1, smallest_rover; |
3f421baa ACM |
109 | |
110 | local_bh_disable(); | |
111 | if (!snum) { | |
227b60f5 SH |
112 | int remaining, rover, low, high; |
113 | ||
a9d8f911 | 114 | again: |
227b60f5 | 115 | inet_get_local_port_range(&low, &high); |
a25de534 | 116 | remaining = (high - low) + 1; |
a9d8f911 | 117 | smallest_rover = rover = net_random() % remaining + low; |
3f421baa | 118 | |
a9d8f911 | 119 | smallest_size = -1; |
3f421baa | 120 | do { |
e3826f1e AW |
121 | if (inet_is_reserved_local_port(rover)) |
122 | goto next_nolock; | |
7f635ab7 PE |
123 | head = &hashinfo->bhash[inet_bhashfn(net, rover, |
124 | hashinfo->bhash_size)]; | |
3f421baa ACM |
125 | spin_lock(&head->lock); |
126 | inet_bind_bucket_for_each(tb, node, &head->chain) | |
09ad9bc7 | 127 | if (net_eq(ib_net(tb), net) && tb->port == rover) { |
a9d8f911 EP |
128 | if (tb->fastreuse > 0 && |
129 | sk->sk_reuse && | |
130 | sk->sk_state != TCP_LISTEN && | |
131 | (tb->num_owners < smallest_size || smallest_size == -1)) { | |
132 | smallest_size = tb->num_owners; | |
133 | smallest_rover = rover; | |
aacd9289 AC |
134 | if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 && |
135 | !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { | |
8d238b25 | 136 | snum = smallest_rover; |
fddb7b57 | 137 | goto tb_found; |
a9d8f911 EP |
138 | } |
139 | } | |
aacd9289 | 140 | if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { |
2b05ad33 | 141 | snum = rover; |
fddb7b57 | 142 | goto tb_found; |
2b05ad33 | 143 | } |
3f421baa | 144 | goto next; |
a9d8f911 | 145 | } |
3f421baa ACM |
146 | break; |
147 | next: | |
148 | spin_unlock(&head->lock); | |
e3826f1e | 149 | next_nolock: |
6df71634 SH |
150 | if (++rover > high) |
151 | rover = low; | |
3f421baa | 152 | } while (--remaining > 0); |
3f421baa ACM |
153 | |
154 | /* Exhausted local port range during search? It is not | |
155 | * possible for us to be holding one of the bind hash | |
156 | * locks if this test triggers, because if 'remaining' | |
157 | * drops to zero, we broke out of the do/while loop at | |
158 | * the top level, not from the 'break;' statement. | |
159 | */ | |
160 | ret = 1; | |
a9d8f911 EP |
161 | if (remaining <= 0) { |
162 | if (smallest_size != -1) { | |
163 | snum = smallest_rover; | |
164 | goto have_snum; | |
165 | } | |
3f421baa | 166 | goto fail; |
a9d8f911 | 167 | } |
3f421baa ACM |
168 | /* OK, here is the one we will use. HEAD is |
169 | * non-NULL and we hold it's mutex. | |
170 | */ | |
171 | snum = rover; | |
172 | } else { | |
a9d8f911 | 173 | have_snum: |
7f635ab7 PE |
174 | head = &hashinfo->bhash[inet_bhashfn(net, snum, |
175 | hashinfo->bhash_size)]; | |
3f421baa ACM |
176 | spin_lock(&head->lock); |
177 | inet_bind_bucket_for_each(tb, node, &head->chain) | |
09ad9bc7 | 178 | if (net_eq(ib_net(tb), net) && tb->port == snum) |
3f421baa ACM |
179 | goto tb_found; |
180 | } | |
181 | tb = NULL; | |
182 | goto tb_not_found; | |
183 | tb_found: | |
184 | if (!hlist_empty(&tb->owners)) { | |
4a17fd52 PE |
185 | if (sk->sk_reuse == SK_FORCE_REUSE) |
186 | goto success; | |
187 | ||
3f421baa | 188 | if (tb->fastreuse > 0 && |
a9d8f911 EP |
189 | sk->sk_reuse && sk->sk_state != TCP_LISTEN && |
190 | smallest_size == -1) { | |
3f421baa ACM |
191 | goto success; |
192 | } else { | |
193 | ret = 1; | |
aacd9289 | 194 | if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) { |
5add3009 SH |
195 | if (sk->sk_reuse && sk->sk_state != TCP_LISTEN && |
196 | smallest_size != -1 && --attempts >= 0) { | |
a9d8f911 EP |
197 | spin_unlock(&head->lock); |
198 | goto again; | |
199 | } | |
aacd9289 | 200 | |
3f421baa | 201 | goto fail_unlock; |
a9d8f911 | 202 | } |
3f421baa ACM |
203 | } |
204 | } | |
205 | tb_not_found: | |
206 | ret = 1; | |
941b1d22 PE |
207 | if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, |
208 | net, head, snum)) == NULL) | |
3f421baa ACM |
209 | goto fail_unlock; |
210 | if (hlist_empty(&tb->owners)) { | |
211 | if (sk->sk_reuse && sk->sk_state != TCP_LISTEN) | |
212 | tb->fastreuse = 1; | |
213 | else | |
214 | tb->fastreuse = 0; | |
215 | } else if (tb->fastreuse && | |
216 | (!sk->sk_reuse || sk->sk_state == TCP_LISTEN)) | |
217 | tb->fastreuse = 0; | |
218 | success: | |
219 | if (!inet_csk(sk)->icsk_bind_hash) | |
220 | inet_bind_hash(sk, tb, snum); | |
547b792c | 221 | WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); |
e905a9ed | 222 | ret = 0; |
3f421baa ACM |
223 | |
224 | fail_unlock: | |
225 | spin_unlock(&head->lock); | |
226 | fail: | |
227 | local_bh_enable(); | |
228 | return ret; | |
229 | } | |
3f421baa ACM |
230 | EXPORT_SYMBOL_GPL(inet_csk_get_port); |
231 | ||
232 | /* | |
233 | * Wait for an incoming connection, avoid race conditions. This must be called | |
234 | * with the socket locked. | |
235 | */ | |
236 | static int inet_csk_wait_for_connect(struct sock *sk, long timeo) | |
237 | { | |
238 | struct inet_connection_sock *icsk = inet_csk(sk); | |
239 | DEFINE_WAIT(wait); | |
240 | int err; | |
241 | ||
242 | /* | |
243 | * True wake-one mechanism for incoming connections: only | |
244 | * one process gets woken up, not the 'whole herd'. | |
245 | * Since we do not 'race & poll' for established sockets | |
246 | * anymore, the common case will execute the loop only once. | |
247 | * | |
248 | * Subtle issue: "add_wait_queue_exclusive()" will be added | |
249 | * after any current non-exclusive waiters, and we know that | |
250 | * it will always _stay_ after any new non-exclusive waiters | |
251 | * because all non-exclusive waiters are added at the | |
252 | * beginning of the wait-queue. As such, it's ok to "drop" | |
253 | * our exclusiveness temporarily when we get woken up without | |
254 | * having to remove and re-insert us on the wait queue. | |
255 | */ | |
256 | for (;;) { | |
aa395145 | 257 | prepare_to_wait_exclusive(sk_sleep(sk), &wait, |
3f421baa ACM |
258 | TASK_INTERRUPTIBLE); |
259 | release_sock(sk); | |
260 | if (reqsk_queue_empty(&icsk->icsk_accept_queue)) | |
261 | timeo = schedule_timeout(timeo); | |
262 | lock_sock(sk); | |
263 | err = 0; | |
264 | if (!reqsk_queue_empty(&icsk->icsk_accept_queue)) | |
265 | break; | |
266 | err = -EINVAL; | |
267 | if (sk->sk_state != TCP_LISTEN) | |
268 | break; | |
269 | err = sock_intr_errno(timeo); | |
270 | if (signal_pending(current)) | |
271 | break; | |
272 | err = -EAGAIN; | |
273 | if (!timeo) | |
274 | break; | |
275 | } | |
aa395145 | 276 | finish_wait(sk_sleep(sk), &wait); |
3f421baa ACM |
277 | return err; |
278 | } | |
279 | ||
280 | /* | |
281 | * This will accept the next outstanding connection. | |
282 | */ | |
283 | struct sock *inet_csk_accept(struct sock *sk, int flags, int *err) | |
284 | { | |
285 | struct inet_connection_sock *icsk = inet_csk(sk); | |
8336886f | 286 | struct request_sock_queue *queue = &icsk->icsk_accept_queue; |
3f421baa | 287 | struct sock *newsk; |
8336886f | 288 | struct request_sock *req; |
3f421baa ACM |
289 | int error; |
290 | ||
291 | lock_sock(sk); | |
292 | ||
293 | /* We need to make sure that this socket is listening, | |
294 | * and that it has something pending. | |
295 | */ | |
296 | error = -EINVAL; | |
297 | if (sk->sk_state != TCP_LISTEN) | |
298 | goto out_err; | |
299 | ||
300 | /* Find already established connection */ | |
8336886f | 301 | if (reqsk_queue_empty(queue)) { |
3f421baa ACM |
302 | long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); |
303 | ||
304 | /* If this is a non blocking socket don't sleep */ | |
305 | error = -EAGAIN; | |
306 | if (!timeo) | |
307 | goto out_err; | |
308 | ||
309 | error = inet_csk_wait_for_connect(sk, timeo); | |
310 | if (error) | |
311 | goto out_err; | |
312 | } | |
8336886f JC |
313 | req = reqsk_queue_remove(queue); |
314 | newsk = req->sk; | |
315 | ||
316 | sk_acceptq_removed(sk); | |
317 | if (sk->sk_type == SOCK_STREAM && queue->fastopenq != NULL) { | |
318 | spin_lock_bh(&queue->fastopenq->lock); | |
319 | if (tcp_rsk(req)->listener) { | |
320 | /* We are still waiting for the final ACK from 3WHS | |
321 | * so can't free req now. Instead, we set req->sk to | |
322 | * NULL to signify that the child socket is taken | |
323 | * so reqsk_fastopen_remove() will free the req | |
324 | * when 3WHS finishes (or is aborted). | |
325 | */ | |
326 | req->sk = NULL; | |
327 | req = NULL; | |
328 | } | |
329 | spin_unlock_bh(&queue->fastopenq->lock); | |
330 | } | |
3f421baa ACM |
331 | out: |
332 | release_sock(sk); | |
8336886f JC |
333 | if (req) |
334 | __reqsk_free(req); | |
3f421baa ACM |
335 | return newsk; |
336 | out_err: | |
337 | newsk = NULL; | |
8336886f | 338 | req = NULL; |
3f421baa ACM |
339 | *err = error; |
340 | goto out; | |
341 | } | |
3f421baa ACM |
342 | EXPORT_SYMBOL(inet_csk_accept); |
343 | ||
344 | /* | |
345 | * Using different timers for retransmit, delayed acks and probes | |
e905a9ed | 346 | * We may wish use just one timer maintaining a list of expire jiffies |
3f421baa ACM |
347 | * to optimize. |
348 | */ | |
349 | void inet_csk_init_xmit_timers(struct sock *sk, | |
350 | void (*retransmit_handler)(unsigned long), | |
351 | void (*delack_handler)(unsigned long), | |
352 | void (*keepalive_handler)(unsigned long)) | |
353 | { | |
354 | struct inet_connection_sock *icsk = inet_csk(sk); | |
355 | ||
b24b8a24 PE |
356 | setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler, |
357 | (unsigned long)sk); | |
358 | setup_timer(&icsk->icsk_delack_timer, delack_handler, | |
359 | (unsigned long)sk); | |
360 | setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk); | |
3f421baa ACM |
361 | icsk->icsk_pending = icsk->icsk_ack.pending = 0; |
362 | } | |
3f421baa ACM |
363 | EXPORT_SYMBOL(inet_csk_init_xmit_timers); |
364 | ||
365 | void inet_csk_clear_xmit_timers(struct sock *sk) | |
366 | { | |
367 | struct inet_connection_sock *icsk = inet_csk(sk); | |
368 | ||
369 | icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0; | |
370 | ||
371 | sk_stop_timer(sk, &icsk->icsk_retransmit_timer); | |
372 | sk_stop_timer(sk, &icsk->icsk_delack_timer); | |
373 | sk_stop_timer(sk, &sk->sk_timer); | |
374 | } | |
3f421baa ACM |
375 | EXPORT_SYMBOL(inet_csk_clear_xmit_timers); |
376 | ||
377 | void inet_csk_delete_keepalive_timer(struct sock *sk) | |
378 | { | |
379 | sk_stop_timer(sk, &sk->sk_timer); | |
380 | } | |
3f421baa ACM |
381 | EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); |
382 | ||
383 | void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) | |
384 | { | |
385 | sk_reset_timer(sk, &sk->sk_timer, jiffies + len); | |
386 | } | |
3f421baa ACM |
387 | EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); |
388 | ||
d9319100 | 389 | struct dst_entry *inet_csk_route_req(struct sock *sk, |
6bd023f3 | 390 | struct flowi4 *fl4, |
ba3f7f04 | 391 | const struct request_sock *req) |
3f421baa ACM |
392 | { |
393 | struct rtable *rt; | |
394 | const struct inet_request_sock *ireq = inet_rsk(req); | |
f6d8bd05 | 395 | struct ip_options_rcu *opt = inet_rsk(req)->opt; |
84a3aa00 | 396 | struct net *net = sock_net(sk); |
3e12939a | 397 | int flags = inet_sk_flowi_flags(sk); |
3f421baa | 398 | |
6bd023f3 | 399 | flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, |
e79d9bc7 | 400 | RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, |
7433819a | 401 | sk->sk_protocol, |
7586eceb | 402 | flags, |
f6d8bd05 | 403 | (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, |
e79d9bc7 | 404 | ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); |
6bd023f3 DM |
405 | security_req_classify_flow(req, flowi4_to_flowi(fl4)); |
406 | rt = ip_route_output_flow(net, fl4, sk); | |
b23dd4fe | 407 | if (IS_ERR(rt)) |
857a6e0a | 408 | goto no_route; |
f8126f1d | 409 | if (opt && opt->opt.is_strictroute && rt->rt_gateway) |
857a6e0a | 410 | goto route_err; |
d8d1f30b | 411 | return &rt->dst; |
857a6e0a IJ |
412 | |
413 | route_err: | |
414 | ip_rt_put(rt); | |
415 | no_route: | |
416 | IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); | |
417 | return NULL; | |
3f421baa | 418 | } |
3f421baa ACM |
419 | EXPORT_SYMBOL_GPL(inet_csk_route_req); |
420 | ||
77357a95 DM |
421 | struct dst_entry *inet_csk_route_child_sock(struct sock *sk, |
422 | struct sock *newsk, | |
423 | const struct request_sock *req) | |
424 | { | |
425 | const struct inet_request_sock *ireq = inet_rsk(req); | |
426 | struct inet_sock *newinet = inet_sk(newsk); | |
1a7b27c9 | 427 | struct ip_options_rcu *opt; |
77357a95 DM |
428 | struct net *net = sock_net(sk); |
429 | struct flowi4 *fl4; | |
430 | struct rtable *rt; | |
431 | ||
432 | fl4 = &newinet->cork.fl.u.ip4; | |
1a7b27c9 CP |
433 | |
434 | rcu_read_lock(); | |
435 | opt = rcu_dereference(newinet->inet_opt); | |
77357a95 DM |
436 | flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, |
437 | RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, | |
438 | sk->sk_protocol, inet_sk_flowi_flags(sk), | |
439 | (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, | |
440 | ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); | |
441 | security_req_classify_flow(req, flowi4_to_flowi(fl4)); | |
442 | rt = ip_route_output_flow(net, fl4, sk); | |
443 | if (IS_ERR(rt)) | |
444 | goto no_route; | |
f8126f1d | 445 | if (opt && opt->opt.is_strictroute && rt->rt_gateway) |
77357a95 | 446 | goto route_err; |
1a7b27c9 | 447 | rcu_read_unlock(); |
77357a95 DM |
448 | return &rt->dst; |
449 | ||
450 | route_err: | |
451 | ip_rt_put(rt); | |
452 | no_route: | |
1a7b27c9 | 453 | rcu_read_unlock(); |
77357a95 DM |
454 | IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); |
455 | return NULL; | |
456 | } | |
457 | EXPORT_SYMBOL_GPL(inet_csk_route_child_sock); | |
458 | ||
6b72977b | 459 | static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport, |
72a3effa | 460 | const u32 rnd, const u32 synq_hsize) |
3f421baa | 461 | { |
6b72977b | 462 | return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1); |
3f421baa ACM |
463 | } |
464 | ||
dfd56b8b | 465 | #if IS_ENABLED(CONFIG_IPV6) |
3f421baa ACM |
466 | #define AF_INET_FAMILY(fam) ((fam) == AF_INET) |
467 | #else | |
468 | #define AF_INET_FAMILY(fam) 1 | |
469 | #endif | |
470 | ||
471 | struct request_sock *inet_csk_search_req(const struct sock *sk, | |
472 | struct request_sock ***prevp, | |
6b72977b | 473 | const __be16 rport, const __be32 raddr, |
7f25afbb | 474 | const __be32 laddr) |
3f421baa ACM |
475 | { |
476 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
477 | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; | |
478 | struct request_sock *req, **prev; | |
479 | ||
480 | for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd, | |
481 | lopt->nr_table_entries)]; | |
482 | (req = *prev) != NULL; | |
483 | prev = &req->dl_next) { | |
484 | const struct inet_request_sock *ireq = inet_rsk(req); | |
485 | ||
486 | if (ireq->rmt_port == rport && | |
487 | ireq->rmt_addr == raddr && | |
488 | ireq->loc_addr == laddr && | |
489 | AF_INET_FAMILY(req->rsk_ops->family)) { | |
547b792c | 490 | WARN_ON(req->sk); |
3f421baa ACM |
491 | *prevp = prev; |
492 | break; | |
493 | } | |
494 | } | |
495 | ||
496 | return req; | |
497 | } | |
3f421baa ACM |
498 | EXPORT_SYMBOL_GPL(inet_csk_search_req); |
499 | ||
500 | void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, | |
c2977c22 | 501 | unsigned long timeout) |
3f421baa ACM |
502 | { |
503 | struct inet_connection_sock *icsk = inet_csk(sk); | |
504 | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; | |
505 | const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, | |
506 | lopt->hash_rnd, lopt->nr_table_entries); | |
507 | ||
508 | reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); | |
509 | inet_csk_reqsk_queue_added(sk, timeout); | |
510 | } | |
4bc2f18b | 511 | EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); |
3f421baa | 512 | |
a019d6fe ACM |
513 | /* Only thing we need from tcp.h */ |
514 | extern int sysctl_tcp_synack_retries; | |
515 | ||
9f1d2604 | 516 | |
0c3d79bc JA |
517 | /* Decide when to expire the request and when to resend SYN-ACK */ |
518 | static inline void syn_ack_recalc(struct request_sock *req, const int thresh, | |
519 | const int max_retries, | |
520 | const u8 rskq_defer_accept, | |
521 | int *expire, int *resend) | |
522 | { | |
523 | if (!rskq_defer_accept) { | |
524 | *expire = req->retrans >= thresh; | |
525 | *resend = 1; | |
526 | return; | |
527 | } | |
528 | *expire = req->retrans >= thresh && | |
529 | (!inet_rsk(req)->acked || req->retrans >= max_retries); | |
530 | /* | |
531 | * Do not resend while waiting for data after ACK, | |
532 | * start to resend on end of deferring period to give | |
533 | * last chance for data or ACK to create established socket. | |
534 | */ | |
535 | *resend = !inet_rsk(req)->acked || | |
536 | req->retrans >= rskq_defer_accept - 1; | |
537 | } | |
538 | ||
a019d6fe ACM |
539 | void inet_csk_reqsk_queue_prune(struct sock *parent, |
540 | const unsigned long interval, | |
541 | const unsigned long timeout, | |
542 | const unsigned long max_rto) | |
543 | { | |
544 | struct inet_connection_sock *icsk = inet_csk(parent); | |
545 | struct request_sock_queue *queue = &icsk->icsk_accept_queue; | |
546 | struct listen_sock *lopt = queue->listen_opt; | |
ec0a1966 DM |
547 | int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries; |
548 | int thresh = max_retries; | |
a019d6fe ACM |
549 | unsigned long now = jiffies; |
550 | struct request_sock **reqp, *req; | |
551 | int i, budget; | |
552 | ||
553 | if (lopt == NULL || lopt->qlen == 0) | |
554 | return; | |
555 | ||
556 | /* Normally all the openreqs are young and become mature | |
557 | * (i.e. converted to established socket) for first timeout. | |
fd4f2cea | 558 | * If synack was not acknowledged for 1 second, it means |
a019d6fe ACM |
559 | * one of the following things: synack was lost, ack was lost, |
560 | * rtt is high or nobody planned to ack (i.e. synflood). | |
561 | * When server is a bit loaded, queue is populated with old | |
562 | * open requests, reducing effective size of queue. | |
563 | * When server is well loaded, queue size reduces to zero | |
564 | * after several minutes of work. It is not synflood, | |
565 | * it is normal operation. The solution is pruning | |
566 | * too old entries overriding normal timeout, when | |
567 | * situation becomes dangerous. | |
568 | * | |
569 | * Essentially, we reserve half of room for young | |
570 | * embrions; and abort old ones without pity, if old | |
571 | * ones are about to clog our table. | |
572 | */ | |
573 | if (lopt->qlen>>(lopt->max_qlen_log-1)) { | |
574 | int young = (lopt->qlen_young<<1); | |
575 | ||
576 | while (thresh > 2) { | |
577 | if (lopt->qlen < young) | |
578 | break; | |
579 | thresh--; | |
580 | young <<= 1; | |
581 | } | |
582 | } | |
583 | ||
ec0a1966 DM |
584 | if (queue->rskq_defer_accept) |
585 | max_retries = queue->rskq_defer_accept; | |
586 | ||
a019d6fe ACM |
587 | budget = 2 * (lopt->nr_table_entries / (timeout / interval)); |
588 | i = lopt->clock_hand; | |
589 | ||
590 | do { | |
591 | reqp=&lopt->syn_table[i]; | |
592 | while ((req = *reqp) != NULL) { | |
593 | if (time_after_eq(now, req->expires)) { | |
0c3d79bc JA |
594 | int expire = 0, resend = 0; |
595 | ||
596 | syn_ack_recalc(req, thresh, max_retries, | |
597 | queue->rskq_defer_accept, | |
598 | &expire, &resend); | |
c72e1183 | 599 | req->rsk_ops->syn_ack_timeout(parent, req); |
0c3d79bc JA |
600 | if (!expire && |
601 | (!resend || | |
e6b4d113 | 602 | !req->rsk_ops->rtx_syn_ack(parent, req, NULL) || |
0c3d79bc | 603 | inet_rsk(req)->acked)) { |
a019d6fe ACM |
604 | unsigned long timeo; |
605 | ||
606 | if (req->retrans++ == 0) | |
607 | lopt->qlen_young--; | |
608 | timeo = min((timeout << req->retrans), max_rto); | |
609 | req->expires = now + timeo; | |
610 | reqp = &req->dl_next; | |
611 | continue; | |
612 | } | |
613 | ||
614 | /* Drop this request */ | |
615 | inet_csk_reqsk_queue_unlink(parent, req, reqp); | |
616 | reqsk_queue_removed(queue, req); | |
617 | reqsk_free(req); | |
618 | continue; | |
619 | } | |
620 | reqp = &req->dl_next; | |
621 | } | |
622 | ||
623 | i = (i + 1) & (lopt->nr_table_entries - 1); | |
624 | ||
625 | } while (--budget > 0); | |
626 | ||
627 | lopt->clock_hand = i; | |
628 | ||
629 | if (lopt->qlen) | |
630 | inet_csk_reset_keepalive_timer(parent, interval); | |
631 | } | |
a019d6fe ACM |
632 | EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune); |
633 | ||
e56c57d0 ED |
634 | /** |
635 | * inet_csk_clone_lock - clone an inet socket, and lock its clone | |
636 | * @sk: the socket to clone | |
637 | * @req: request_sock | |
638 | * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) | |
639 | * | |
640 | * Caller must unlock socket even in error path (bh_unlock_sock(newsk)) | |
641 | */ | |
642 | struct sock *inet_csk_clone_lock(const struct sock *sk, | |
643 | const struct request_sock *req, | |
644 | const gfp_t priority) | |
9f1d2604 | 645 | { |
e56c57d0 | 646 | struct sock *newsk = sk_clone_lock(sk, priority); |
9f1d2604 ACM |
647 | |
648 | if (newsk != NULL) { | |
649 | struct inet_connection_sock *newicsk = inet_csk(newsk); | |
650 | ||
651 | newsk->sk_state = TCP_SYN_RECV; | |
652 | newicsk->icsk_bind_hash = NULL; | |
653 | ||
c720c7e8 ED |
654 | inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port; |
655 | inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port); | |
656 | inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port; | |
9f1d2604 ACM |
657 | newsk->sk_write_space = sk_stream_write_space; |
658 | ||
659 | newicsk->icsk_retransmits = 0; | |
6687e988 ACM |
660 | newicsk->icsk_backoff = 0; |
661 | newicsk->icsk_probes_out = 0; | |
9f1d2604 ACM |
662 | |
663 | /* Deinitialize accept_queue to trap illegal accesses. */ | |
664 | memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue)); | |
4237c75c VY |
665 | |
666 | security_inet_csk_clone(newsk, req); | |
9f1d2604 ACM |
667 | } |
668 | return newsk; | |
669 | } | |
e56c57d0 | 670 | EXPORT_SYMBOL_GPL(inet_csk_clone_lock); |
a019d6fe ACM |
671 | |
672 | /* | |
673 | * At this point, there should be no process reference to this | |
674 | * socket, and thus no user references at all. Therefore we | |
675 | * can assume the socket waitqueue is inactive and nobody will | |
676 | * try to jump onto it. | |
677 | */ | |
678 | void inet_csk_destroy_sock(struct sock *sk) | |
679 | { | |
547b792c IJ |
680 | WARN_ON(sk->sk_state != TCP_CLOSE); |
681 | WARN_ON(!sock_flag(sk, SOCK_DEAD)); | |
a019d6fe ACM |
682 | |
683 | /* It cannot be in hash table! */ | |
547b792c | 684 | WARN_ON(!sk_unhashed(sk)); |
a019d6fe | 685 | |
c720c7e8 ED |
686 | /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */ |
687 | WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash); | |
a019d6fe ACM |
688 | |
689 | sk->sk_prot->destroy(sk); | |
690 | ||
691 | sk_stream_kill_queues(sk); | |
692 | ||
693 | xfrm_sk_free_policy(sk); | |
694 | ||
695 | sk_refcnt_debug_release(sk); | |
696 | ||
dd24c001 | 697 | percpu_counter_dec(sk->sk_prot->orphan_count); |
a019d6fe ACM |
698 | sock_put(sk); |
699 | } | |
a019d6fe ACM |
700 | EXPORT_SYMBOL(inet_csk_destroy_sock); |
701 | ||
702 | int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) | |
703 | { | |
704 | struct inet_sock *inet = inet_sk(sk); | |
705 | struct inet_connection_sock *icsk = inet_csk(sk); | |
706 | int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries); | |
707 | ||
708 | if (rc != 0) | |
709 | return rc; | |
710 | ||
711 | sk->sk_max_ack_backlog = 0; | |
712 | sk->sk_ack_backlog = 0; | |
713 | inet_csk_delack_init(sk); | |
714 | ||
715 | /* There is race window here: we announce ourselves listening, | |
716 | * but this transition is still not validated by get_port(). | |
717 | * It is OK, because this socket enters to hash table only | |
718 | * after validation is complete. | |
719 | */ | |
720 | sk->sk_state = TCP_LISTEN; | |
c720c7e8 ED |
721 | if (!sk->sk_prot->get_port(sk, inet->inet_num)) { |
722 | inet->inet_sport = htons(inet->inet_num); | |
a019d6fe ACM |
723 | |
724 | sk_dst_reset(sk); | |
725 | sk->sk_prot->hash(sk); | |
726 | ||
727 | return 0; | |
728 | } | |
729 | ||
730 | sk->sk_state = TCP_CLOSE; | |
731 | __reqsk_queue_destroy(&icsk->icsk_accept_queue); | |
732 | return -EADDRINUSE; | |
733 | } | |
a019d6fe ACM |
734 | EXPORT_SYMBOL_GPL(inet_csk_listen_start); |
735 | ||
736 | /* | |
737 | * This routine closes sockets which have been at least partially | |
738 | * opened, but not yet accepted. | |
739 | */ | |
740 | void inet_csk_listen_stop(struct sock *sk) | |
741 | { | |
742 | struct inet_connection_sock *icsk = inet_csk(sk); | |
8336886f | 743 | struct request_sock_queue *queue = &icsk->icsk_accept_queue; |
a019d6fe ACM |
744 | struct request_sock *acc_req; |
745 | struct request_sock *req; | |
746 | ||
747 | inet_csk_delete_keepalive_timer(sk); | |
748 | ||
749 | /* make all the listen_opt local to us */ | |
8336886f | 750 | acc_req = reqsk_queue_yank_acceptq(queue); |
a019d6fe ACM |
751 | |
752 | /* Following specs, it would be better either to send FIN | |
753 | * (and enter FIN-WAIT-1, it is normal close) | |
754 | * or to send active reset (abort). | |
755 | * Certainly, it is pretty dangerous while synflood, but it is | |
756 | * bad justification for our negligence 8) | |
757 | * To be honest, we are not able to make either | |
758 | * of the variants now. --ANK | |
759 | */ | |
8336886f | 760 | reqsk_queue_destroy(queue); |
a019d6fe ACM |
761 | |
762 | while ((req = acc_req) != NULL) { | |
763 | struct sock *child = req->sk; | |
764 | ||
765 | acc_req = req->dl_next; | |
766 | ||
767 | local_bh_disable(); | |
768 | bh_lock_sock(child); | |
547b792c | 769 | WARN_ON(sock_owned_by_user(child)); |
a019d6fe ACM |
770 | sock_hold(child); |
771 | ||
772 | sk->sk_prot->disconnect(child, O_NONBLOCK); | |
773 | ||
774 | sock_orphan(child); | |
775 | ||
eb4dea58 HX |
776 | percpu_counter_inc(sk->sk_prot->orphan_count); |
777 | ||
8336886f JC |
778 | if (sk->sk_type == SOCK_STREAM && tcp_rsk(req)->listener) { |
779 | BUG_ON(tcp_sk(child)->fastopen_rsk != req); | |
780 | BUG_ON(sk != tcp_rsk(req)->listener); | |
781 | ||
782 | /* Paranoid, to prevent race condition if | |
783 | * an inbound pkt destined for child is | |
784 | * blocked by sock lock in tcp_v4_rcv(). | |
785 | * Also to satisfy an assertion in | |
786 | * tcp_v4_destroy_sock(). | |
787 | */ | |
788 | tcp_sk(child)->fastopen_rsk = NULL; | |
789 | sock_put(sk); | |
790 | } | |
a019d6fe ACM |
791 | inet_csk_destroy_sock(child); |
792 | ||
793 | bh_unlock_sock(child); | |
794 | local_bh_enable(); | |
795 | sock_put(child); | |
796 | ||
797 | sk_acceptq_removed(sk); | |
798 | __reqsk_free(req); | |
799 | } | |
8336886f JC |
800 | if (queue->fastopenq != NULL) { |
801 | /* Free all the reqs queued in rskq_rst_head. */ | |
802 | spin_lock_bh(&queue->fastopenq->lock); | |
803 | acc_req = queue->fastopenq->rskq_rst_head; | |
804 | queue->fastopenq->rskq_rst_head = NULL; | |
805 | spin_unlock_bh(&queue->fastopenq->lock); | |
806 | while ((req = acc_req) != NULL) { | |
807 | acc_req = req->dl_next; | |
808 | __reqsk_free(req); | |
809 | } | |
810 | } | |
547b792c | 811 | WARN_ON(sk->sk_ack_backlog); |
a019d6fe | 812 | } |
a019d6fe | 813 | EXPORT_SYMBOL_GPL(inet_csk_listen_stop); |
af05dc93 ACM |
814 | |
815 | void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) | |
816 | { | |
817 | struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; | |
818 | const struct inet_sock *inet = inet_sk(sk); | |
819 | ||
820 | sin->sin_family = AF_INET; | |
c720c7e8 ED |
821 | sin->sin_addr.s_addr = inet->inet_daddr; |
822 | sin->sin_port = inet->inet_dport; | |
af05dc93 | 823 | } |
af05dc93 | 824 | EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr); |
c4d93909 | 825 | |
dec73ff0 ACM |
826 | #ifdef CONFIG_COMPAT |
827 | int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, | |
828 | char __user *optval, int __user *optlen) | |
829 | { | |
dbeff12b | 830 | const struct inet_connection_sock *icsk = inet_csk(sk); |
dec73ff0 ACM |
831 | |
832 | if (icsk->icsk_af_ops->compat_getsockopt != NULL) | |
833 | return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname, | |
834 | optval, optlen); | |
835 | return icsk->icsk_af_ops->getsockopt(sk, level, optname, | |
836 | optval, optlen); | |
837 | } | |
dec73ff0 ACM |
838 | EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt); |
839 | ||
840 | int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, | |
b7058842 | 841 | char __user *optval, unsigned int optlen) |
dec73ff0 | 842 | { |
dbeff12b | 843 | const struct inet_connection_sock *icsk = inet_csk(sk); |
dec73ff0 ACM |
844 | |
845 | if (icsk->icsk_af_ops->compat_setsockopt != NULL) | |
846 | return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname, | |
847 | optval, optlen); | |
848 | return icsk->icsk_af_ops->setsockopt(sk, level, optname, | |
849 | optval, optlen); | |
850 | } | |
dec73ff0 ACM |
851 | EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt); |
852 | #endif | |
80d0a69f DM |
853 | |
854 | static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl) | |
855 | { | |
5abf7f7e ED |
856 | const struct inet_sock *inet = inet_sk(sk); |
857 | const struct ip_options_rcu *inet_opt; | |
80d0a69f DM |
858 | __be32 daddr = inet->inet_daddr; |
859 | struct flowi4 *fl4; | |
860 | struct rtable *rt; | |
861 | ||
862 | rcu_read_lock(); | |
863 | inet_opt = rcu_dereference(inet->inet_opt); | |
864 | if (inet_opt && inet_opt->opt.srr) | |
865 | daddr = inet_opt->opt.faddr; | |
866 | fl4 = &fl->u.ip4; | |
867 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, | |
868 | inet->inet_saddr, inet->inet_dport, | |
869 | inet->inet_sport, sk->sk_protocol, | |
870 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); | |
871 | if (IS_ERR(rt)) | |
872 | rt = NULL; | |
873 | if (rt) | |
874 | sk_setup_caps(sk, &rt->dst); | |
875 | rcu_read_unlock(); | |
876 | ||
877 | return &rt->dst; | |
878 | } | |
879 | ||
880 | struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu) | |
881 | { | |
882 | struct dst_entry *dst = __sk_dst_check(sk, 0); | |
883 | struct inet_sock *inet = inet_sk(sk); | |
884 | ||
885 | if (!dst) { | |
886 | dst = inet_csk_rebuild_route(sk, &inet->cork.fl); | |
887 | if (!dst) | |
888 | goto out; | |
889 | } | |
6700c270 | 890 | dst->ops->update_pmtu(dst, sk, NULL, mtu); |
80d0a69f DM |
891 | |
892 | dst = __sk_dst_check(sk, 0); | |
893 | if (!dst) | |
894 | dst = inet_csk_rebuild_route(sk, &inet->cork.fl); | |
895 | out: | |
896 | return dst; | |
897 | } | |
898 | EXPORT_SYMBOL_GPL(inet_csk_update_pmtu); |