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Merge tag 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux...
[deliverable/linux.git] / net / ipv4 / inet_connection_sock.c
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
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>
25 #include <net/xfrm.h>
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 void inet_get_local_port_range(struct net *net, int *low, int *high)
33 {
34 unsigned int seq;
35
36 do {
37 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
38
39 *low = net->ipv4.ip_local_ports.range[0];
40 *high = net->ipv4.ip_local_ports.range[1];
41 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
42 }
43 EXPORT_SYMBOL(inet_get_local_port_range);
44
45 int inet_csk_bind_conflict(const struct sock *sk,
46 const struct inet_bind_bucket *tb, bool relax)
47 {
48 struct sock *sk2;
49 int reuse = sk->sk_reuse;
50 int reuseport = sk->sk_reuseport;
51 kuid_t uid = sock_i_uid((struct sock *)sk);
52
53 /*
54 * Unlike other sk lookup places we do not check
55 * for sk_net here, since _all_ the socks listed
56 * in tb->owners list belong to the same net - the
57 * one this bucket belongs to.
58 */
59
60 sk_for_each_bound(sk2, &tb->owners) {
61 if (sk != sk2 &&
62 !inet_v6_ipv6only(sk2) &&
63 (!sk->sk_bound_dev_if ||
64 !sk2->sk_bound_dev_if ||
65 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
66 if ((!reuse || !sk2->sk_reuse ||
67 sk2->sk_state == TCP_LISTEN) &&
68 (!reuseport || !sk2->sk_reuseport ||
69 (sk2->sk_state != TCP_TIME_WAIT &&
70 !uid_eq(uid, sock_i_uid(sk2))))) {
71
72 if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
73 sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
74 break;
75 }
76 if (!relax && reuse && sk2->sk_reuse &&
77 sk2->sk_state != TCP_LISTEN) {
78
79 if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
80 sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
81 break;
82 }
83 }
84 }
85 return sk2 != NULL;
86 }
87 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
88
89 /* Obtain a reference to a local port for the given sock,
90 * if snum is zero it means select any available local port.
91 */
92 int inet_csk_get_port(struct sock *sk, unsigned short snum)
93 {
94 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
95 struct inet_bind_hashbucket *head;
96 struct inet_bind_bucket *tb;
97 int ret, attempts = 5;
98 struct net *net = sock_net(sk);
99 int smallest_size = -1, smallest_rover;
100 kuid_t uid = sock_i_uid(sk);
101
102 local_bh_disable();
103 if (!snum) {
104 int remaining, rover, low, high;
105
106 again:
107 inet_get_local_port_range(net, &low, &high);
108 remaining = (high - low) + 1;
109 smallest_rover = rover = prandom_u32() % remaining + low;
110
111 smallest_size = -1;
112 do {
113 if (inet_is_local_reserved_port(net, rover))
114 goto next_nolock;
115 head = &hashinfo->bhash[inet_bhashfn(net, rover,
116 hashinfo->bhash_size)];
117 spin_lock(&head->lock);
118 inet_bind_bucket_for_each(tb, &head->chain)
119 if (net_eq(ib_net(tb), net) && tb->port == rover) {
120 if (((tb->fastreuse > 0 &&
121 sk->sk_reuse &&
122 sk->sk_state != TCP_LISTEN) ||
123 (tb->fastreuseport > 0 &&
124 sk->sk_reuseport &&
125 uid_eq(tb->fastuid, uid))) &&
126 (tb->num_owners < smallest_size || smallest_size == -1)) {
127 smallest_size = tb->num_owners;
128 smallest_rover = rover;
129 if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 &&
130 !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
131 snum = smallest_rover;
132 goto tb_found;
133 }
134 }
135 if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
136 snum = rover;
137 goto tb_found;
138 }
139 goto next;
140 }
141 break;
142 next:
143 spin_unlock(&head->lock);
144 next_nolock:
145 if (++rover > high)
146 rover = low;
147 } while (--remaining > 0);
148
149 /* Exhausted local port range during search? It is not
150 * possible for us to be holding one of the bind hash
151 * locks if this test triggers, because if 'remaining'
152 * drops to zero, we broke out of the do/while loop at
153 * the top level, not from the 'break;' statement.
154 */
155 ret = 1;
156 if (remaining <= 0) {
157 if (smallest_size != -1) {
158 snum = smallest_rover;
159 goto have_snum;
160 }
161 goto fail;
162 }
163 /* OK, here is the one we will use. HEAD is
164 * non-NULL and we hold it's mutex.
165 */
166 snum = rover;
167 } else {
168 have_snum:
169 head = &hashinfo->bhash[inet_bhashfn(net, snum,
170 hashinfo->bhash_size)];
171 spin_lock(&head->lock);
172 inet_bind_bucket_for_each(tb, &head->chain)
173 if (net_eq(ib_net(tb), net) && tb->port == snum)
174 goto tb_found;
175 }
176 tb = NULL;
177 goto tb_not_found;
178 tb_found:
179 if (!hlist_empty(&tb->owners)) {
180 if (sk->sk_reuse == SK_FORCE_REUSE)
181 goto success;
182
183 if (((tb->fastreuse > 0 &&
184 sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
185 (tb->fastreuseport > 0 &&
186 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
187 smallest_size == -1) {
188 goto success;
189 } else {
190 ret = 1;
191 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
192 if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
193 (tb->fastreuseport > 0 &&
194 sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
195 smallest_size != -1 && --attempts >= 0) {
196 spin_unlock(&head->lock);
197 goto again;
198 }
199
200 goto fail_unlock;
201 }
202 }
203 }
204 tb_not_found:
205 ret = 1;
206 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
207 net, head, snum)) == NULL)
208 goto fail_unlock;
209 if (hlist_empty(&tb->owners)) {
210 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
211 tb->fastreuse = 1;
212 else
213 tb->fastreuse = 0;
214 if (sk->sk_reuseport) {
215 tb->fastreuseport = 1;
216 tb->fastuid = uid;
217 } else
218 tb->fastreuseport = 0;
219 } else {
220 if (tb->fastreuse &&
221 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
222 tb->fastreuse = 0;
223 if (tb->fastreuseport &&
224 (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid)))
225 tb->fastreuseport = 0;
226 }
227 success:
228 if (!inet_csk(sk)->icsk_bind_hash)
229 inet_bind_hash(sk, tb, snum);
230 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
231 ret = 0;
232
233 fail_unlock:
234 spin_unlock(&head->lock);
235 fail:
236 local_bh_enable();
237 return ret;
238 }
239 EXPORT_SYMBOL_GPL(inet_csk_get_port);
240
241 /*
242 * Wait for an incoming connection, avoid race conditions. This must be called
243 * with the socket locked.
244 */
245 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
246 {
247 struct inet_connection_sock *icsk = inet_csk(sk);
248 DEFINE_WAIT(wait);
249 int err;
250
251 /*
252 * True wake-one mechanism for incoming connections: only
253 * one process gets woken up, not the 'whole herd'.
254 * Since we do not 'race & poll' for established sockets
255 * anymore, the common case will execute the loop only once.
256 *
257 * Subtle issue: "add_wait_queue_exclusive()" will be added
258 * after any current non-exclusive waiters, and we know that
259 * it will always _stay_ after any new non-exclusive waiters
260 * because all non-exclusive waiters are added at the
261 * beginning of the wait-queue. As such, it's ok to "drop"
262 * our exclusiveness temporarily when we get woken up without
263 * having to remove and re-insert us on the wait queue.
264 */
265 for (;;) {
266 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
267 TASK_INTERRUPTIBLE);
268 release_sock(sk);
269 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
270 timeo = schedule_timeout(timeo);
271 sched_annotate_sleep();
272 lock_sock(sk);
273 err = 0;
274 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
275 break;
276 err = -EINVAL;
277 if (sk->sk_state != TCP_LISTEN)
278 break;
279 err = sock_intr_errno(timeo);
280 if (signal_pending(current))
281 break;
282 err = -EAGAIN;
283 if (!timeo)
284 break;
285 }
286 finish_wait(sk_sleep(sk), &wait);
287 return err;
288 }
289
290 /*
291 * This will accept the next outstanding connection.
292 */
293 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
294 {
295 struct inet_connection_sock *icsk = inet_csk(sk);
296 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
297 struct sock *newsk;
298 struct request_sock *req;
299 int error;
300
301 lock_sock(sk);
302
303 /* We need to make sure that this socket is listening,
304 * and that it has something pending.
305 */
306 error = -EINVAL;
307 if (sk->sk_state != TCP_LISTEN)
308 goto out_err;
309
310 /* Find already established connection */
311 if (reqsk_queue_empty(queue)) {
312 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
313
314 /* If this is a non blocking socket don't sleep */
315 error = -EAGAIN;
316 if (!timeo)
317 goto out_err;
318
319 error = inet_csk_wait_for_connect(sk, timeo);
320 if (error)
321 goto out_err;
322 }
323 req = reqsk_queue_remove(queue);
324 newsk = req->sk;
325
326 sk_acceptq_removed(sk);
327 if (sk->sk_protocol == IPPROTO_TCP && queue->fastopenq != NULL) {
328 spin_lock_bh(&queue->fastopenq->lock);
329 if (tcp_rsk(req)->listener) {
330 /* We are still waiting for the final ACK from 3WHS
331 * so can't free req now. Instead, we set req->sk to
332 * NULL to signify that the child socket is taken
333 * so reqsk_fastopen_remove() will free the req
334 * when 3WHS finishes (or is aborted).
335 */
336 req->sk = NULL;
337 req = NULL;
338 }
339 spin_unlock_bh(&queue->fastopenq->lock);
340 }
341 out:
342 release_sock(sk);
343 if (req)
344 __reqsk_free(req);
345 return newsk;
346 out_err:
347 newsk = NULL;
348 req = NULL;
349 *err = error;
350 goto out;
351 }
352 EXPORT_SYMBOL(inet_csk_accept);
353
354 /*
355 * Using different timers for retransmit, delayed acks and probes
356 * We may wish use just one timer maintaining a list of expire jiffies
357 * to optimize.
358 */
359 void inet_csk_init_xmit_timers(struct sock *sk,
360 void (*retransmit_handler)(unsigned long),
361 void (*delack_handler)(unsigned long),
362 void (*keepalive_handler)(unsigned long))
363 {
364 struct inet_connection_sock *icsk = inet_csk(sk);
365
366 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
367 (unsigned long)sk);
368 setup_timer(&icsk->icsk_delack_timer, delack_handler,
369 (unsigned long)sk);
370 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
371 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
372 }
373 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
374
375 void inet_csk_clear_xmit_timers(struct sock *sk)
376 {
377 struct inet_connection_sock *icsk = inet_csk(sk);
378
379 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
380
381 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
382 sk_stop_timer(sk, &icsk->icsk_delack_timer);
383 sk_stop_timer(sk, &sk->sk_timer);
384 }
385 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
386
387 void inet_csk_delete_keepalive_timer(struct sock *sk)
388 {
389 sk_stop_timer(sk, &sk->sk_timer);
390 }
391 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
392
393 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
394 {
395 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
396 }
397 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
398
399 struct dst_entry *inet_csk_route_req(struct sock *sk,
400 struct flowi4 *fl4,
401 const struct request_sock *req)
402 {
403 struct rtable *rt;
404 const struct inet_request_sock *ireq = inet_rsk(req);
405 struct ip_options_rcu *opt = inet_rsk(req)->opt;
406 struct net *net = sock_net(sk);
407 int flags = inet_sk_flowi_flags(sk);
408
409 flowi4_init_output(fl4, sk->sk_bound_dev_if, ireq->ir_mark,
410 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
411 sk->sk_protocol,
412 flags,
413 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
414 ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
415 security_req_classify_flow(req, flowi4_to_flowi(fl4));
416 rt = ip_route_output_flow(net, fl4, sk);
417 if (IS_ERR(rt))
418 goto no_route;
419 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
420 goto route_err;
421 return &rt->dst;
422
423 route_err:
424 ip_rt_put(rt);
425 no_route:
426 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
427 return NULL;
428 }
429 EXPORT_SYMBOL_GPL(inet_csk_route_req);
430
431 struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
432 struct sock *newsk,
433 const struct request_sock *req)
434 {
435 const struct inet_request_sock *ireq = inet_rsk(req);
436 struct inet_sock *newinet = inet_sk(newsk);
437 struct ip_options_rcu *opt;
438 struct net *net = sock_net(sk);
439 struct flowi4 *fl4;
440 struct rtable *rt;
441
442 fl4 = &newinet->cork.fl.u.ip4;
443
444 rcu_read_lock();
445 opt = rcu_dereference(newinet->inet_opt);
446 flowi4_init_output(fl4, sk->sk_bound_dev_if, inet_rsk(req)->ir_mark,
447 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
448 sk->sk_protocol, inet_sk_flowi_flags(sk),
449 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
450 ireq->ir_loc_addr, ireq->ir_rmt_port, inet_sk(sk)->inet_sport);
451 security_req_classify_flow(req, flowi4_to_flowi(fl4));
452 rt = ip_route_output_flow(net, fl4, sk);
453 if (IS_ERR(rt))
454 goto no_route;
455 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
456 goto route_err;
457 rcu_read_unlock();
458 return &rt->dst;
459
460 route_err:
461 ip_rt_put(rt);
462 no_route:
463 rcu_read_unlock();
464 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
465 return NULL;
466 }
467 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
468
469 static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
470 const u32 rnd, const u32 synq_hsize)
471 {
472 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
473 }
474
475 #if IS_ENABLED(CONFIG_IPV6)
476 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
477 #else
478 #define AF_INET_FAMILY(fam) 1
479 #endif
480
481 struct request_sock *inet_csk_search_req(const struct sock *sk,
482 struct request_sock ***prevp,
483 const __be16 rport, const __be32 raddr,
484 const __be32 laddr)
485 {
486 const struct inet_connection_sock *icsk = inet_csk(sk);
487 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
488 struct request_sock *req, **prev;
489
490 for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
491 lopt->nr_table_entries)];
492 (req = *prev) != NULL;
493 prev = &req->dl_next) {
494 const struct inet_request_sock *ireq = inet_rsk(req);
495
496 if (ireq->ir_rmt_port == rport &&
497 ireq->ir_rmt_addr == raddr &&
498 ireq->ir_loc_addr == laddr &&
499 AF_INET_FAMILY(req->rsk_ops->family)) {
500 WARN_ON(req->sk);
501 *prevp = prev;
502 break;
503 }
504 }
505
506 return req;
507 }
508 EXPORT_SYMBOL_GPL(inet_csk_search_req);
509
510 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
511 unsigned long timeout)
512 {
513 struct inet_connection_sock *icsk = inet_csk(sk);
514 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
515 const u32 h = inet_synq_hash(inet_rsk(req)->ir_rmt_addr,
516 inet_rsk(req)->ir_rmt_port,
517 lopt->hash_rnd, lopt->nr_table_entries);
518
519 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
520 inet_csk_reqsk_queue_added(sk, timeout);
521 }
522 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
523
524 /* Only thing we need from tcp.h */
525 extern int sysctl_tcp_synack_retries;
526
527
528 /* Decide when to expire the request and when to resend SYN-ACK */
529 static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
530 const int max_retries,
531 const u8 rskq_defer_accept,
532 int *expire, int *resend)
533 {
534 if (!rskq_defer_accept) {
535 *expire = req->num_timeout >= thresh;
536 *resend = 1;
537 return;
538 }
539 *expire = req->num_timeout >= thresh &&
540 (!inet_rsk(req)->acked || req->num_timeout >= max_retries);
541 /*
542 * Do not resend while waiting for data after ACK,
543 * start to resend on end of deferring period to give
544 * last chance for data or ACK to create established socket.
545 */
546 *resend = !inet_rsk(req)->acked ||
547 req->num_timeout >= rskq_defer_accept - 1;
548 }
549
550 int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req)
551 {
552 int err = req->rsk_ops->rtx_syn_ack(parent, req);
553
554 if (!err)
555 req->num_retrans++;
556 return err;
557 }
558 EXPORT_SYMBOL(inet_rtx_syn_ack);
559
560 void inet_csk_reqsk_queue_prune(struct sock *parent,
561 const unsigned long interval,
562 const unsigned long timeout,
563 const unsigned long max_rto)
564 {
565 struct inet_connection_sock *icsk = inet_csk(parent);
566 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
567 struct listen_sock *lopt = queue->listen_opt;
568 int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
569 int thresh = max_retries;
570 unsigned long now = jiffies;
571 struct request_sock **reqp, *req;
572 int i, budget;
573
574 if (lopt == NULL || lopt->qlen == 0)
575 return;
576
577 /* Normally all the openreqs are young and become mature
578 * (i.e. converted to established socket) for first timeout.
579 * If synack was not acknowledged for 1 second, it means
580 * one of the following things: synack was lost, ack was lost,
581 * rtt is high or nobody planned to ack (i.e. synflood).
582 * When server is a bit loaded, queue is populated with old
583 * open requests, reducing effective size of queue.
584 * When server is well loaded, queue size reduces to zero
585 * after several minutes of work. It is not synflood,
586 * it is normal operation. The solution is pruning
587 * too old entries overriding normal timeout, when
588 * situation becomes dangerous.
589 *
590 * Essentially, we reserve half of room for young
591 * embrions; and abort old ones without pity, if old
592 * ones are about to clog our table.
593 */
594 if (lopt->qlen>>(lopt->max_qlen_log-1)) {
595 int young = (lopt->qlen_young<<1);
596
597 while (thresh > 2) {
598 if (lopt->qlen < young)
599 break;
600 thresh--;
601 young <<= 1;
602 }
603 }
604
605 if (queue->rskq_defer_accept)
606 max_retries = queue->rskq_defer_accept;
607
608 budget = 2 * (lopt->nr_table_entries / (timeout / interval));
609 i = lopt->clock_hand;
610
611 do {
612 reqp=&lopt->syn_table[i];
613 while ((req = *reqp) != NULL) {
614 if (time_after_eq(now, req->expires)) {
615 int expire = 0, resend = 0;
616
617 syn_ack_recalc(req, thresh, max_retries,
618 queue->rskq_defer_accept,
619 &expire, &resend);
620 req->rsk_ops->syn_ack_timeout(parent, req);
621 if (!expire &&
622 (!resend ||
623 !inet_rtx_syn_ack(parent, req) ||
624 inet_rsk(req)->acked)) {
625 unsigned long timeo;
626
627 if (req->num_timeout++ == 0)
628 lopt->qlen_young--;
629 timeo = min(timeout << req->num_timeout,
630 max_rto);
631 req->expires = now + timeo;
632 reqp = &req->dl_next;
633 continue;
634 }
635
636 /* Drop this request */
637 inet_csk_reqsk_queue_unlink(parent, req, reqp);
638 reqsk_queue_removed(queue, req);
639 reqsk_free(req);
640 continue;
641 }
642 reqp = &req->dl_next;
643 }
644
645 i = (i + 1) & (lopt->nr_table_entries - 1);
646
647 } while (--budget > 0);
648
649 lopt->clock_hand = i;
650
651 if (lopt->qlen)
652 inet_csk_reset_keepalive_timer(parent, interval);
653 }
654 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
655
656 /**
657 * inet_csk_clone_lock - clone an inet socket, and lock its clone
658 * @sk: the socket to clone
659 * @req: request_sock
660 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
661 *
662 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
663 */
664 struct sock *inet_csk_clone_lock(const struct sock *sk,
665 const struct request_sock *req,
666 const gfp_t priority)
667 {
668 struct sock *newsk = sk_clone_lock(sk, priority);
669
670 if (newsk != NULL) {
671 struct inet_connection_sock *newicsk = inet_csk(newsk);
672
673 newsk->sk_state = TCP_SYN_RECV;
674 newicsk->icsk_bind_hash = NULL;
675
676 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
677 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
678 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
679 newsk->sk_write_space = sk_stream_write_space;
680
681 newsk->sk_mark = inet_rsk(req)->ir_mark;
682
683 newicsk->icsk_retransmits = 0;
684 newicsk->icsk_backoff = 0;
685 newicsk->icsk_probes_out = 0;
686
687 /* Deinitialize accept_queue to trap illegal accesses. */
688 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
689
690 security_inet_csk_clone(newsk, req);
691 }
692 return newsk;
693 }
694 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
695
696 /*
697 * At this point, there should be no process reference to this
698 * socket, and thus no user references at all. Therefore we
699 * can assume the socket waitqueue is inactive and nobody will
700 * try to jump onto it.
701 */
702 void inet_csk_destroy_sock(struct sock *sk)
703 {
704 WARN_ON(sk->sk_state != TCP_CLOSE);
705 WARN_ON(!sock_flag(sk, SOCK_DEAD));
706
707 /* It cannot be in hash table! */
708 WARN_ON(!sk_unhashed(sk));
709
710 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
711 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
712
713 sk->sk_prot->destroy(sk);
714
715 sk_stream_kill_queues(sk);
716
717 xfrm_sk_free_policy(sk);
718
719 sk_refcnt_debug_release(sk);
720
721 percpu_counter_dec(sk->sk_prot->orphan_count);
722 sock_put(sk);
723 }
724 EXPORT_SYMBOL(inet_csk_destroy_sock);
725
726 /* This function allows to force a closure of a socket after the call to
727 * tcp/dccp_create_openreq_child().
728 */
729 void inet_csk_prepare_forced_close(struct sock *sk)
730 __releases(&sk->sk_lock.slock)
731 {
732 /* sk_clone_lock locked the socket and set refcnt to 2 */
733 bh_unlock_sock(sk);
734 sock_put(sk);
735
736 /* The below has to be done to allow calling inet_csk_destroy_sock */
737 sock_set_flag(sk, SOCK_DEAD);
738 percpu_counter_inc(sk->sk_prot->orphan_count);
739 inet_sk(sk)->inet_num = 0;
740 }
741 EXPORT_SYMBOL(inet_csk_prepare_forced_close);
742
743 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
744 {
745 struct inet_sock *inet = inet_sk(sk);
746 struct inet_connection_sock *icsk = inet_csk(sk);
747 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
748
749 if (rc != 0)
750 return rc;
751
752 sk->sk_max_ack_backlog = 0;
753 sk->sk_ack_backlog = 0;
754 inet_csk_delack_init(sk);
755
756 /* There is race window here: we announce ourselves listening,
757 * but this transition is still not validated by get_port().
758 * It is OK, because this socket enters to hash table only
759 * after validation is complete.
760 */
761 sk->sk_state = TCP_LISTEN;
762 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
763 inet->inet_sport = htons(inet->inet_num);
764
765 sk_dst_reset(sk);
766 sk->sk_prot->hash(sk);
767
768 return 0;
769 }
770
771 sk->sk_state = TCP_CLOSE;
772 __reqsk_queue_destroy(&icsk->icsk_accept_queue);
773 return -EADDRINUSE;
774 }
775 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
776
777 /*
778 * This routine closes sockets which have been at least partially
779 * opened, but not yet accepted.
780 */
781 void inet_csk_listen_stop(struct sock *sk)
782 {
783 struct inet_connection_sock *icsk = inet_csk(sk);
784 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
785 struct request_sock *acc_req;
786 struct request_sock *req;
787
788 inet_csk_delete_keepalive_timer(sk);
789
790 /* make all the listen_opt local to us */
791 acc_req = reqsk_queue_yank_acceptq(queue);
792
793 /* Following specs, it would be better either to send FIN
794 * (and enter FIN-WAIT-1, it is normal close)
795 * or to send active reset (abort).
796 * Certainly, it is pretty dangerous while synflood, but it is
797 * bad justification for our negligence 8)
798 * To be honest, we are not able to make either
799 * of the variants now. --ANK
800 */
801 reqsk_queue_destroy(queue);
802
803 while ((req = acc_req) != NULL) {
804 struct sock *child = req->sk;
805
806 acc_req = req->dl_next;
807
808 local_bh_disable();
809 bh_lock_sock(child);
810 WARN_ON(sock_owned_by_user(child));
811 sock_hold(child);
812
813 sk->sk_prot->disconnect(child, O_NONBLOCK);
814
815 sock_orphan(child);
816
817 percpu_counter_inc(sk->sk_prot->orphan_count);
818
819 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->listener) {
820 BUG_ON(tcp_sk(child)->fastopen_rsk != req);
821 BUG_ON(sk != tcp_rsk(req)->listener);
822
823 /* Paranoid, to prevent race condition if
824 * an inbound pkt destined for child is
825 * blocked by sock lock in tcp_v4_rcv().
826 * Also to satisfy an assertion in
827 * tcp_v4_destroy_sock().
828 */
829 tcp_sk(child)->fastopen_rsk = NULL;
830 sock_put(sk);
831 }
832 inet_csk_destroy_sock(child);
833
834 bh_unlock_sock(child);
835 local_bh_enable();
836 sock_put(child);
837
838 sk_acceptq_removed(sk);
839 __reqsk_free(req);
840 }
841 if (queue->fastopenq != NULL) {
842 /* Free all the reqs queued in rskq_rst_head. */
843 spin_lock_bh(&queue->fastopenq->lock);
844 acc_req = queue->fastopenq->rskq_rst_head;
845 queue->fastopenq->rskq_rst_head = NULL;
846 spin_unlock_bh(&queue->fastopenq->lock);
847 while ((req = acc_req) != NULL) {
848 acc_req = req->dl_next;
849 __reqsk_free(req);
850 }
851 }
852 WARN_ON(sk->sk_ack_backlog);
853 }
854 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
855
856 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
857 {
858 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
859 const struct inet_sock *inet = inet_sk(sk);
860
861 sin->sin_family = AF_INET;
862 sin->sin_addr.s_addr = inet->inet_daddr;
863 sin->sin_port = inet->inet_dport;
864 }
865 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
866
867 #ifdef CONFIG_COMPAT
868 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
869 char __user *optval, int __user *optlen)
870 {
871 const struct inet_connection_sock *icsk = inet_csk(sk);
872
873 if (icsk->icsk_af_ops->compat_getsockopt != NULL)
874 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
875 optval, optlen);
876 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
877 optval, optlen);
878 }
879 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
880
881 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
882 char __user *optval, unsigned int optlen)
883 {
884 const struct inet_connection_sock *icsk = inet_csk(sk);
885
886 if (icsk->icsk_af_ops->compat_setsockopt != NULL)
887 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
888 optval, optlen);
889 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
890 optval, optlen);
891 }
892 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
893 #endif
894
895 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
896 {
897 const struct inet_sock *inet = inet_sk(sk);
898 const struct ip_options_rcu *inet_opt;
899 __be32 daddr = inet->inet_daddr;
900 struct flowi4 *fl4;
901 struct rtable *rt;
902
903 rcu_read_lock();
904 inet_opt = rcu_dereference(inet->inet_opt);
905 if (inet_opt && inet_opt->opt.srr)
906 daddr = inet_opt->opt.faddr;
907 fl4 = &fl->u.ip4;
908 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
909 inet->inet_saddr, inet->inet_dport,
910 inet->inet_sport, sk->sk_protocol,
911 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
912 if (IS_ERR(rt))
913 rt = NULL;
914 if (rt)
915 sk_setup_caps(sk, &rt->dst);
916 rcu_read_unlock();
917
918 return &rt->dst;
919 }
920
921 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
922 {
923 struct dst_entry *dst = __sk_dst_check(sk, 0);
924 struct inet_sock *inet = inet_sk(sk);
925
926 if (!dst) {
927 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
928 if (!dst)
929 goto out;
930 }
931 dst->ops->update_pmtu(dst, sk, NULL, mtu);
932
933 dst = __sk_dst_check(sk, 0);
934 if (!dst)
935 dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
936 out:
937 return dst;
938 }
939 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);
Linux kernel - Deliverables
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