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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
28const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
29EXPORT_SYMBOL(inet_csk_timer_bug_msg);
30#endif
31
32
33
34
35struct local_ports sysctl_local_ports __read_mostly = {
36 .lock = SEQLOCK_UNLOCKED,
37 .range = { 32768, 61000 },
38};
39
40void inet_get_local_port_range(int *low, int *high)
41{
42 unsigned seq;
43 do {
44 seq = read_seqbegin(&sysctl_local_ports.lock);
45
46 *low = sysctl_local_ports.range[0];
47 *high = sysctl_local_ports.range[1];
48 } while (read_seqretry(&sysctl_local_ports.lock, seq));
49}
50EXPORT_SYMBOL(inet_get_local_port_range);
51
52int inet_csk_bind_conflict(const struct sock *sk,
53 const struct inet_bind_bucket *tb)
54{
55 const __be32 sk_rcv_saddr = inet_rcv_saddr(sk);
56 struct sock *sk2;
57 struct hlist_node *node;
58 int reuse = sk->sk_reuse;
59
60
61
62
63
64
65
66
67 sk_for_each_bound(sk2, node, &tb->owners) {
68 if (sk != sk2 &&
69 !inet_v6_ipv6only(sk2) &&
70 (!sk->sk_bound_dev_if ||
71 !sk2->sk_bound_dev_if ||
72 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
73 if (!reuse || !sk2->sk_reuse ||
74 sk2->sk_state == TCP_LISTEN) {
75 const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
76 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
77 sk2_rcv_saddr == sk_rcv_saddr)
78 break;
79 }
80 }
81 }
82 return node != NULL;
83}
84
85EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
86
87
88
89
90int inet_csk_get_port(struct sock *sk, unsigned short snum)
91{
92 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
93 struct inet_bind_hashbucket *head;
94 struct hlist_node *node;
95 struct inet_bind_bucket *tb;
96 int ret, attempts = 5;
97 struct net *net = sock_net(sk);
98 int smallest_size = -1, smallest_rover;
99
100 local_bh_disable();
101 if (!snum) {
102 int remaining, rover, low, high;
103
104again:
105 inet_get_local_port_range(&low, &high);
106 remaining = (high - low) + 1;
107 smallest_rover = rover = net_random() % remaining + low;
108
109 smallest_size = -1;
110 do {
111 head = &hashinfo->bhash[inet_bhashfn(net, rover,
112 hashinfo->bhash_size)];
113 spin_lock(&head->lock);
114 inet_bind_bucket_for_each(tb, node, &head->chain)
115 if (ib_net(tb) == net && tb->port == rover) {
116 if (tb->fastreuse > 0 &&
117 sk->sk_reuse &&
118 sk->sk_state != TCP_LISTEN &&
119 (tb->num_owners < smallest_size || smallest_size == -1)) {
120 smallest_size = tb->num_owners;
121 smallest_rover = rover;
122 if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
123 spin_unlock(&head->lock);
124 snum = smallest_rover;
125 goto have_snum;
126 }
127 }
128 goto next;
129 }
130 break;
131 next:
132 spin_unlock(&head->lock);
133 if (++rover > high)
134 rover = low;
135 } while (--remaining > 0);
136
137
138
139
140
141
142
143 ret = 1;
144 if (remaining <= 0) {
145 if (smallest_size != -1) {
146 snum = smallest_rover;
147 goto have_snum;
148 }
149 goto fail;
150 }
151
152
153
154 snum = rover;
155 } else {
156have_snum:
157 head = &hashinfo->bhash[inet_bhashfn(net, snum,
158 hashinfo->bhash_size)];
159 spin_lock(&head->lock);
160 inet_bind_bucket_for_each(tb, node, &head->chain)
161 if (ib_net(tb) == net && tb->port == snum)
162 goto tb_found;
163 }
164 tb = NULL;
165 goto tb_not_found;
166tb_found:
167 if (!hlist_empty(&tb->owners)) {
168 if (tb->fastreuse > 0 &&
169 sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
170 smallest_size == -1) {
171 goto success;
172 } else {
173 ret = 1;
174 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
175 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
176 smallest_size != -1 && --attempts >= 0) {
177 spin_unlock(&head->lock);
178 goto again;
179 }
180 goto fail_unlock;
181 }
182 }
183 }
184tb_not_found:
185 ret = 1;
186 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
187 net, head, snum)) == NULL)
188 goto fail_unlock;
189 if (hlist_empty(&tb->owners)) {
190 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
191 tb->fastreuse = 1;
192 else
193 tb->fastreuse = 0;
194 } else if (tb->fastreuse &&
195 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
196 tb->fastreuse = 0;
197success:
198 if (!inet_csk(sk)->icsk_bind_hash)
199 inet_bind_hash(sk, tb, snum);
200 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
201 ret = 0;
202
203fail_unlock:
204 spin_unlock(&head->lock);
205fail:
206 local_bh_enable();
207 return ret;
208}
209
210EXPORT_SYMBOL_GPL(inet_csk_get_port);
211
212
213
214
215
216static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
217{
218 struct inet_connection_sock *icsk = inet_csk(sk);
219 DEFINE_WAIT(wait);
220 int err;
221
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233
234
235
236 for (;;) {
237 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
238 TASK_INTERRUPTIBLE);
239 release_sock(sk);
240 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
241 timeo = schedule_timeout(timeo);
242 lock_sock(sk);
243 err = 0;
244 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
245 break;
246 err = -EINVAL;
247 if (sk->sk_state != TCP_LISTEN)
248 break;
249 err = sock_intr_errno(timeo);
250 if (signal_pending(current))
251 break;
252 err = -EAGAIN;
253 if (!timeo)
254 break;
255 }
256 finish_wait(sk->sk_sleep, &wait);
257 return err;
258}
259
260
261
262
263struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
264{
265 struct inet_connection_sock *icsk = inet_csk(sk);
266 struct sock *newsk;
267 int error;
268
269 lock_sock(sk);
270
271
272
273
274 error = -EINVAL;
275 if (sk->sk_state != TCP_LISTEN)
276 goto out_err;
277
278
279 if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
280 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
281
282
283 error = -EAGAIN;
284 if (!timeo)
285 goto out_err;
286
287 error = inet_csk_wait_for_connect(sk, timeo);
288 if (error)
289 goto out_err;
290 }
291
292 newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
293 WARN_ON(newsk->sk_state == TCP_SYN_RECV);
294out:
295 release_sock(sk);
296 return newsk;
297out_err:
298 newsk = NULL;
299 *err = error;
300 goto out;
301}
302
303EXPORT_SYMBOL(inet_csk_accept);
304
305
306
307
308
309
310void inet_csk_init_xmit_timers(struct sock *sk,
311 void (*retransmit_handler)(unsigned long),
312 void (*delack_handler)(unsigned long),
313 void (*keepalive_handler)(unsigned long))
314{
315 struct inet_connection_sock *icsk = inet_csk(sk);
316
317 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
318 (unsigned long)sk);
319 setup_timer(&icsk->icsk_delack_timer, delack_handler,
320 (unsigned long)sk);
321 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
322 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
323}
324
325EXPORT_SYMBOL(inet_csk_init_xmit_timers);
326
327void inet_csk_clear_xmit_timers(struct sock *sk)
328{
329 struct inet_connection_sock *icsk = inet_csk(sk);
330
331 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
332
333 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
334 sk_stop_timer(sk, &icsk->icsk_delack_timer);
335 sk_stop_timer(sk, &sk->sk_timer);
336}
337
338EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
339
340void inet_csk_delete_keepalive_timer(struct sock *sk)
341{
342 sk_stop_timer(sk, &sk->sk_timer);
343}
344
345EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
346
347void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
348{
349 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
350}
351
352EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
353
354struct dst_entry *inet_csk_route_req(struct sock *sk,
355 const struct request_sock *req)
356{
357 struct rtable *rt;
358 const struct inet_request_sock *ireq = inet_rsk(req);
359 struct ip_options *opt = inet_rsk(req)->opt;
360 struct flowi fl = { .oif = sk->sk_bound_dev_if,
361 .nl_u = { .ip4_u =
362 { .daddr = ((opt && opt->srr) ?
363 opt->faddr :
364 ireq->rmt_addr),
365 .saddr = ireq->loc_addr,
366 .tos = RT_CONN_FLAGS(sk) } },
367 .proto = sk->sk_protocol,
368 .flags = inet_sk_flowi_flags(sk),
369 .uli_u = { .ports =
370 { .sport = inet_sk(sk)->sport,
371 .dport = ireq->rmt_port } } };
372 struct net *net = sock_net(sk);
373
374 security_req_classify_flow(req, &fl);
375 if (ip_route_output_flow(net, &rt, &fl, sk, 0))
376 goto no_route;
377 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
378 goto route_err;
379 return &rt->u.dst;
380
381route_err:
382 ip_rt_put(rt);
383no_route:
384 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
385 return NULL;
386}
387
388EXPORT_SYMBOL_GPL(inet_csk_route_req);
389
390static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
391 const u32 rnd, const u32 synq_hsize)
392{
393 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
394}
395
396#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
397#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
398#else
399#define AF_INET_FAMILY(fam) 1
400#endif
401
402struct request_sock *inet_csk_search_req(const struct sock *sk,
403 struct request_sock ***prevp,
404 const __be16 rport, const __be32 raddr,
405 const __be32 laddr)
406{
407 const struct inet_connection_sock *icsk = inet_csk(sk);
408 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
409 struct request_sock *req, **prev;
410
411 for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
412 lopt->nr_table_entries)];
413 (req = *prev) != NULL;
414 prev = &req->dl_next) {
415 const struct inet_request_sock *ireq = inet_rsk(req);
416
417 if (ireq->rmt_port == rport &&
418 ireq->rmt_addr == raddr &&
419 ireq->loc_addr == laddr &&
420 AF_INET_FAMILY(req->rsk_ops->family)) {
421 WARN_ON(req->sk);
422 *prevp = prev;
423 break;
424 }
425 }
426
427 return req;
428}
429
430EXPORT_SYMBOL_GPL(inet_csk_search_req);
431
432void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
433 unsigned long timeout)
434{
435 struct inet_connection_sock *icsk = inet_csk(sk);
436 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
437 const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
438 lopt->hash_rnd, lopt->nr_table_entries);
439
440 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
441 inet_csk_reqsk_queue_added(sk, timeout);
442}
443
444
445extern int sysctl_tcp_synack_retries;
446
447EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
448
449
450static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
451 const int max_retries,
452 const u8 rskq_defer_accept,
453 int *expire, int *resend)
454{
455 if (!rskq_defer_accept) {
456 *expire = req->retrans >= thresh;
457 *resend = 1;
458 return;
459 }
460 *expire = req->retrans >= thresh &&
461 (!inet_rsk(req)->acked || req->retrans >= max_retries);
462
463
464
465
466
467 *resend = !inet_rsk(req)->acked ||
468 req->retrans >= rskq_defer_accept - 1;
469}
470
471void inet_csk_reqsk_queue_prune(struct sock *parent,
472 const unsigned long interval,
473 const unsigned long timeout,
474 const unsigned long max_rto)
475{
476 struct inet_connection_sock *icsk = inet_csk(parent);
477 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
478 struct listen_sock *lopt = queue->listen_opt;
479 int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
480 int thresh = max_retries;
481 unsigned long now = jiffies;
482 struct request_sock **reqp, *req;
483 int i, budget;
484
485 if (lopt == NULL || lopt->qlen == 0)
486 return;
487
488
489
490
491
492
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495
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503
504
505 if (lopt->qlen>>(lopt->max_qlen_log-1)) {
506 int young = (lopt->qlen_young<<1);
507
508 while (thresh > 2) {
509 if (lopt->qlen < young)
510 break;
511 thresh--;
512 young <<= 1;
513 }
514 }
515
516 if (queue->rskq_defer_accept)
517 max_retries = queue->rskq_defer_accept;
518
519 budget = 2 * (lopt->nr_table_entries / (timeout / interval));
520 i = lopt->clock_hand;
521
522 do {
523 reqp=&lopt->syn_table[i];
524 while ((req = *reqp) != NULL) {
525 if (time_after_eq(now, req->expires)) {
526 int expire = 0, resend = 0;
527
528 syn_ack_recalc(req, thresh, max_retries,
529 queue->rskq_defer_accept,
530 &expire, &resend);
531 if (!expire &&
532 (!resend ||
533 !req->rsk_ops->rtx_syn_ack(parent, req) ||
534 inet_rsk(req)->acked)) {
535 unsigned long timeo;
536
537 if (req->retrans++ == 0)
538 lopt->qlen_young--;
539 timeo = min((timeout << req->retrans), max_rto);
540 req->expires = now + timeo;
541 reqp = &req->dl_next;
542 continue;
543 }
544
545
546 inet_csk_reqsk_queue_unlink(parent, req, reqp);
547 reqsk_queue_removed(queue, req);
548 reqsk_free(req);
549 continue;
550 }
551 reqp = &req->dl_next;
552 }
553
554 i = (i + 1) & (lopt->nr_table_entries - 1);
555
556 } while (--budget > 0);
557
558 lopt->clock_hand = i;
559
560 if (lopt->qlen)
561 inet_csk_reset_keepalive_timer(parent, interval);
562}
563
564EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
565
566struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
567 const gfp_t priority)
568{
569 struct sock *newsk = sk_clone(sk, priority);
570
571 if (newsk != NULL) {
572 struct inet_connection_sock *newicsk = inet_csk(newsk);
573
574 newsk->sk_state = TCP_SYN_RECV;
575 newicsk->icsk_bind_hash = NULL;
576
577 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
578 inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
579 inet_sk(newsk)->sport = inet_rsk(req)->loc_port;
580 newsk->sk_write_space = sk_stream_write_space;
581
582 newicsk->icsk_retransmits = 0;
583 newicsk->icsk_backoff = 0;
584 newicsk->icsk_probes_out = 0;
585
586
587 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
588
589 security_inet_csk_clone(newsk, req);
590 }
591 return newsk;
592}
593
594EXPORT_SYMBOL_GPL(inet_csk_clone);
595
596
597
598
599
600
601
602void inet_csk_destroy_sock(struct sock *sk)
603{
604 WARN_ON(sk->sk_state != TCP_CLOSE);
605 WARN_ON(!sock_flag(sk, SOCK_DEAD));
606
607
608 WARN_ON(!sk_unhashed(sk));
609
610
611 WARN_ON(inet_sk(sk)->num && !inet_csk(sk)->icsk_bind_hash);
612
613 sk->sk_prot->destroy(sk);
614
615 sk_stream_kill_queues(sk);
616
617 xfrm_sk_free_policy(sk);
618
619 sk_refcnt_debug_release(sk);
620
621 percpu_counter_dec(sk->sk_prot->orphan_count);
622 sock_put(sk);
623}
624
625EXPORT_SYMBOL(inet_csk_destroy_sock);
626
627int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
628{
629 struct inet_sock *inet = inet_sk(sk);
630 struct inet_connection_sock *icsk = inet_csk(sk);
631 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
632
633 if (rc != 0)
634 return rc;
635
636 sk->sk_max_ack_backlog = 0;
637 sk->sk_ack_backlog = 0;
638 inet_csk_delack_init(sk);
639
640
641
642
643
644
645 sk->sk_state = TCP_LISTEN;
646 if (!sk->sk_prot->get_port(sk, inet->num)) {
647 inet->sport = htons(inet->num);
648
649 sk_dst_reset(sk);
650 sk->sk_prot->hash(sk);
651
652 return 0;
653 }
654
655 sk->sk_state = TCP_CLOSE;
656 __reqsk_queue_destroy(&icsk->icsk_accept_queue);
657 return -EADDRINUSE;
658}
659
660EXPORT_SYMBOL_GPL(inet_csk_listen_start);
661
662
663
664
665
666void inet_csk_listen_stop(struct sock *sk)
667{
668 struct inet_connection_sock *icsk = inet_csk(sk);
669 struct request_sock *acc_req;
670 struct request_sock *req;
671
672 inet_csk_delete_keepalive_timer(sk);
673
674
675 acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
676
677
678
679
680
681
682
683
684
685 reqsk_queue_destroy(&icsk->icsk_accept_queue);
686
687 while ((req = acc_req) != NULL) {
688 struct sock *child = req->sk;
689
690 acc_req = req->dl_next;
691
692 local_bh_disable();
693 bh_lock_sock(child);
694 WARN_ON(sock_owned_by_user(child));
695 sock_hold(child);
696
697 sk->sk_prot->disconnect(child, O_NONBLOCK);
698
699 sock_orphan(child);
700
701 percpu_counter_inc(sk->sk_prot->orphan_count);
702
703 inet_csk_destroy_sock(child);
704
705 bh_unlock_sock(child);
706 local_bh_enable();
707 sock_put(child);
708
709 sk_acceptq_removed(sk);
710 __reqsk_free(req);
711 }
712 WARN_ON(sk->sk_ack_backlog);
713}
714
715EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
716
717void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
718{
719 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
720 const struct inet_sock *inet = inet_sk(sk);
721
722 sin->sin_family = AF_INET;
723 sin->sin_addr.s_addr = inet->daddr;
724 sin->sin_port = inet->dport;
725}
726
727EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
728
729#ifdef CONFIG_COMPAT
730int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
731 char __user *optval, int __user *optlen)
732{
733 const struct inet_connection_sock *icsk = inet_csk(sk);
734
735 if (icsk->icsk_af_ops->compat_getsockopt != NULL)
736 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
737 optval, optlen);
738 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
739 optval, optlen);
740}
741
742EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
743
744int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
745 char __user *optval, unsigned int optlen)
746{
747 const struct inet_connection_sock *icsk = inet_csk(sk);
748
749 if (icsk->icsk_af_ops->compat_setsockopt != NULL)
750 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
751 optval, optlen);
752 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
753 optval, optlen);
754}
755
756EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
757#endif
758