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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
40unsigned long *sysctl_local_reserved_ports;
41EXPORT_SYMBOL(sysctl_local_reserved_ports);
42
43void inet_get_local_port_range(int *low, int *high)
44{
45 unsigned seq;
46 do {
47 seq = read_seqbegin(&sysctl_local_ports.lock);
48
49 *low = sysctl_local_ports.range[0];
50 *high = sysctl_local_ports.range[1];
51 } while (read_seqretry(&sysctl_local_ports.lock, seq));
52}
53EXPORT_SYMBOL(inet_get_local_port_range);
54
55int inet_csk_bind_conflict(const struct sock *sk,
56 const struct inet_bind_bucket *tb)
57{
58 const __be32 sk_rcv_saddr = inet_rcv_saddr(sk);
59 struct sock *sk2;
60 struct hlist_node *node;
61 int reuse = sk->sk_reuse;
62
63
64
65
66
67
68
69
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 ||
77 sk2->sk_state == TCP_LISTEN) {
78 const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
79 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
80 sk2_rcv_saddr == sk_rcv_saddr)
81 break;
82 }
83 }
84 }
85 return node != NULL;
86}
87
88EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
89
90
91
92
93int inet_csk_get_port(struct sock *sk, unsigned short snum)
94{
95 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
96 struct inet_bind_hashbucket *head;
97 struct hlist_node *node;
98 struct inet_bind_bucket *tb;
99 int ret, attempts = 5;
100 struct net *net = sock_net(sk);
101 int smallest_size = -1, smallest_rover;
102
103 local_bh_disable();
104 if (!snum) {
105 int remaining, rover, low, high;
106
107again:
108 inet_get_local_port_range(&low, &high);
109 remaining = (high - low) + 1;
110 smallest_rover = rover = net_random() % remaining + low;
111
112 smallest_size = -1;
113 do {
114 if (inet_is_reserved_local_port(rover))
115 goto next_nolock;
116 head = &hashinfo->bhash[inet_bhashfn(net, rover,
117 hashinfo->bhash_size)];
118 spin_lock(&head->lock);
119 inet_bind_bucket_for_each(tb, node, &head->chain)
120 if (net_eq(ib_net(tb), net) && tb->port == rover) {
121 if (tb->fastreuse > 0 &&
122 sk->sk_reuse &&
123 sk->sk_state != TCP_LISTEN &&
124 (tb->num_owners < smallest_size || smallest_size == -1)) {
125 smallest_size = tb->num_owners;
126 smallest_rover = rover;
127 if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
128 spin_unlock(&head->lock);
129 snum = smallest_rover;
130 goto have_snum;
131 }
132 }
133 goto next;
134 }
135 break;
136 next:
137 spin_unlock(&head->lock);
138 next_nolock:
139 if (++rover > high)
140 rover = low;
141 } while (--remaining > 0);
142
143
144
145
146
147
148
149 ret = 1;
150 if (remaining <= 0) {
151 if (smallest_size != -1) {
152 snum = smallest_rover;
153 goto have_snum;
154 }
155 goto fail;
156 }
157
158
159
160 snum = rover;
161 } else {
162have_snum:
163 head = &hashinfo->bhash[inet_bhashfn(net, snum,
164 hashinfo->bhash_size)];
165 spin_lock(&head->lock);
166 inet_bind_bucket_for_each(tb, node, &head->chain)
167 if (net_eq(ib_net(tb), net) && tb->port == snum)
168 goto tb_found;
169 }
170 tb = NULL;
171 goto tb_not_found;
172tb_found:
173 if (!hlist_empty(&tb->owners)) {
174 if (tb->fastreuse > 0 &&
175 sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
176 smallest_size == -1) {
177 goto success;
178 } else {
179 ret = 1;
180 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
181 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
182 smallest_size != -1 && --attempts >= 0) {
183 spin_unlock(&head->lock);
184 goto again;
185 }
186 goto fail_unlock;
187 }
188 }
189 }
190tb_not_found:
191 ret = 1;
192 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
193 net, head, snum)) == NULL)
194 goto fail_unlock;
195 if (hlist_empty(&tb->owners)) {
196 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
197 tb->fastreuse = 1;
198 else
199 tb->fastreuse = 0;
200 } else if (tb->fastreuse &&
201 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
202 tb->fastreuse = 0;
203success:
204 if (!inet_csk(sk)->icsk_bind_hash)
205 inet_bind_hash(sk, tb, snum);
206 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
207 ret = 0;
208
209fail_unlock:
210 spin_unlock(&head->lock);
211fail:
212 local_bh_enable();
213 return ret;
214}
215
216EXPORT_SYMBOL_GPL(inet_csk_get_port);
217
218
219
220
221
222static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
223{
224 struct inet_connection_sock *icsk = inet_csk(sk);
225 DEFINE_WAIT(wait);
226 int err;
227
228
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239
240
241
242 for (;;) {
243 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
244 TASK_INTERRUPTIBLE);
245 release_sock(sk);
246 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
247 timeo = schedule_timeout(timeo);
248 lock_sock(sk);
249 err = 0;
250 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
251 break;
252 err = -EINVAL;
253 if (sk->sk_state != TCP_LISTEN)
254 break;
255 err = sock_intr_errno(timeo);
256 if (signal_pending(current))
257 break;
258 err = -EAGAIN;
259 if (!timeo)
260 break;
261 }
262 finish_wait(sk_sleep(sk), &wait);
263 return err;
264}
265
266
267
268
269struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
270{
271 struct inet_connection_sock *icsk = inet_csk(sk);
272 struct sock *newsk;
273 int error;
274
275 lock_sock(sk);
276
277
278
279
280 error = -EINVAL;
281 if (sk->sk_state != TCP_LISTEN)
282 goto out_err;
283
284
285 if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
286 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
287
288
289 error = -EAGAIN;
290 if (!timeo)
291 goto out_err;
292
293 error = inet_csk_wait_for_connect(sk, timeo);
294 if (error)
295 goto out_err;
296 }
297
298 newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
299 WARN_ON(newsk->sk_state == TCP_SYN_RECV);
300out:
301 release_sock(sk);
302 return newsk;
303out_err:
304 newsk = NULL;
305 *err = error;
306 goto out;
307}
308
309EXPORT_SYMBOL(inet_csk_accept);
310
311
312
313
314
315
316void inet_csk_init_xmit_timers(struct sock *sk,
317 void (*retransmit_handler)(unsigned long),
318 void (*delack_handler)(unsigned long),
319 void (*keepalive_handler)(unsigned long))
320{
321 struct inet_connection_sock *icsk = inet_csk(sk);
322
323 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
324 (unsigned long)sk);
325 setup_timer(&icsk->icsk_delack_timer, delack_handler,
326 (unsigned long)sk);
327 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
328 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
329}
330
331EXPORT_SYMBOL(inet_csk_init_xmit_timers);
332
333void inet_csk_clear_xmit_timers(struct sock *sk)
334{
335 struct inet_connection_sock *icsk = inet_csk(sk);
336
337 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
338
339 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
340 sk_stop_timer(sk, &icsk->icsk_delack_timer);
341 sk_stop_timer(sk, &sk->sk_timer);
342}
343
344EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
345
346void inet_csk_delete_keepalive_timer(struct sock *sk)
347{
348 sk_stop_timer(sk, &sk->sk_timer);
349}
350
351EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
352
353void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
354{
355 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
356}
357
358EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
359
360struct dst_entry *inet_csk_route_req(struct sock *sk,
361 const struct request_sock *req)
362{
363 struct rtable *rt;
364 const struct inet_request_sock *ireq = inet_rsk(req);
365 struct ip_options *opt = inet_rsk(req)->opt;
366 struct flowi fl = { .oif = sk->sk_bound_dev_if,
367 .mark = sk->sk_mark,
368 .nl_u = { .ip4_u =
369 { .daddr = ((opt && opt->srr) ?
370 opt->faddr :
371 ireq->rmt_addr),
372 .saddr = ireq->loc_addr,
373 .tos = RT_CONN_FLAGS(sk) } },
374 .proto = sk->sk_protocol,
375 .flags = inet_sk_flowi_flags(sk),
376 .uli_u = { .ports =
377 { .sport = inet_sk(sk)->inet_sport,
378 .dport = ireq->rmt_port } } };
379 struct net *net = sock_net(sk);
380
381 security_req_classify_flow(req, &fl);
382 if (ip_route_output_flow(net, &rt, &fl, sk, 0))
383 goto no_route;
384 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
385 goto route_err;
386 return &rt->u.dst;
387
388route_err:
389 ip_rt_put(rt);
390no_route:
391 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
392 return NULL;
393}
394
395EXPORT_SYMBOL_GPL(inet_csk_route_req);
396
397static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
398 const u32 rnd, const u32 synq_hsize)
399{
400 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
401}
402
403#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
404#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
405#else
406#define AF_INET_FAMILY(fam) 1
407#endif
408
409struct request_sock *inet_csk_search_req(const struct sock *sk,
410 struct request_sock ***prevp,
411 const __be16 rport, const __be32 raddr,
412 const __be32 laddr)
413{
414 const struct inet_connection_sock *icsk = inet_csk(sk);
415 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
416 struct request_sock *req, **prev;
417
418 for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
419 lopt->nr_table_entries)];
420 (req = *prev) != NULL;
421 prev = &req->dl_next) {
422 const struct inet_request_sock *ireq = inet_rsk(req);
423
424 if (ireq->rmt_port == rport &&
425 ireq->rmt_addr == raddr &&
426 ireq->loc_addr == laddr &&
427 AF_INET_FAMILY(req->rsk_ops->family)) {
428 WARN_ON(req->sk);
429 *prevp = prev;
430 break;
431 }
432 }
433
434 return req;
435}
436
437EXPORT_SYMBOL_GPL(inet_csk_search_req);
438
439void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
440 unsigned long timeout)
441{
442 struct inet_connection_sock *icsk = inet_csk(sk);
443 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
444 const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
445 lopt->hash_rnd, lopt->nr_table_entries);
446
447 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
448 inet_csk_reqsk_queue_added(sk, timeout);
449}
450
451
452extern int sysctl_tcp_synack_retries;
453
454EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
455
456
457static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
458 const int max_retries,
459 const u8 rskq_defer_accept,
460 int *expire, int *resend)
461{
462 if (!rskq_defer_accept) {
463 *expire = req->retrans >= thresh;
464 *resend = 1;
465 return;
466 }
467 *expire = req->retrans >= thresh &&
468 (!inet_rsk(req)->acked || req->retrans >= max_retries);
469
470
471
472
473
474 *resend = !inet_rsk(req)->acked ||
475 req->retrans >= rskq_defer_accept - 1;
476}
477
478void inet_csk_reqsk_queue_prune(struct sock *parent,
479 const unsigned long interval,
480 const unsigned long timeout,
481 const unsigned long max_rto)
482{
483 struct inet_connection_sock *icsk = inet_csk(parent);
484 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
485 struct listen_sock *lopt = queue->listen_opt;
486 int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
487 int thresh = max_retries;
488 unsigned long now = jiffies;
489 struct request_sock **reqp, *req;
490 int i, budget;
491
492 if (lopt == NULL || lopt->qlen == 0)
493 return;
494
495
496
497
498
499
500
501
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505
506
507
508
509
510
511
512 if (lopt->qlen>>(lopt->max_qlen_log-1)) {
513 int young = (lopt->qlen_young<<1);
514
515 while (thresh > 2) {
516 if (lopt->qlen < young)
517 break;
518 thresh--;
519 young <<= 1;
520 }
521 }
522
523 if (queue->rskq_defer_accept)
524 max_retries = queue->rskq_defer_accept;
525
526 budget = 2 * (lopt->nr_table_entries / (timeout / interval));
527 i = lopt->clock_hand;
528
529 do {
530 reqp=&lopt->syn_table[i];
531 while ((req = *reqp) != NULL) {
532 if (time_after_eq(now, req->expires)) {
533 int expire = 0, resend = 0;
534
535 syn_ack_recalc(req, thresh, max_retries,
536 queue->rskq_defer_accept,
537 &expire, &resend);
538 if (req->rsk_ops->syn_ack_timeout)
539 req->rsk_ops->syn_ack_timeout(parent, req);
540 if (!expire &&
541 (!resend ||
542 !req->rsk_ops->rtx_syn_ack(parent, req, NULL) ||
543 inet_rsk(req)->acked)) {
544 unsigned long timeo;
545
546 if (req->retrans++ == 0)
547 lopt->qlen_young--;
548 timeo = min((timeout << req->retrans), max_rto);
549 req->expires = now + timeo;
550 reqp = &req->dl_next;
551 continue;
552 }
553
554
555 inet_csk_reqsk_queue_unlink(parent, req, reqp);
556 reqsk_queue_removed(queue, req);
557 reqsk_free(req);
558 continue;
559 }
560 reqp = &req->dl_next;
561 }
562
563 i = (i + 1) & (lopt->nr_table_entries - 1);
564
565 } while (--budget > 0);
566
567 lopt->clock_hand = i;
568
569 if (lopt->qlen)
570 inet_csk_reset_keepalive_timer(parent, interval);
571}
572
573EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
574
575struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
576 const gfp_t priority)
577{
578 struct sock *newsk = sk_clone(sk, priority);
579
580 if (newsk != NULL) {
581 struct inet_connection_sock *newicsk = inet_csk(newsk);
582
583 newsk->sk_state = TCP_SYN_RECV;
584 newicsk->icsk_bind_hash = NULL;
585
586 inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port;
587 inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port);
588 inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port;
589 newsk->sk_write_space = sk_stream_write_space;
590
591 newicsk->icsk_retransmits = 0;
592 newicsk->icsk_backoff = 0;
593 newicsk->icsk_probes_out = 0;
594
595
596 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
597
598 security_inet_csk_clone(newsk, req);
599 }
600 return newsk;
601}
602
603EXPORT_SYMBOL_GPL(inet_csk_clone);
604
605
606
607
608
609
610
611void inet_csk_destroy_sock(struct sock *sk)
612{
613 WARN_ON(sk->sk_state != TCP_CLOSE);
614 WARN_ON(!sock_flag(sk, SOCK_DEAD));
615
616
617 WARN_ON(!sk_unhashed(sk));
618
619
620 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
621
622 sk->sk_prot->destroy(sk);
623
624 sk_stream_kill_queues(sk);
625
626 xfrm_sk_free_policy(sk);
627
628 sk_refcnt_debug_release(sk);
629
630 percpu_counter_dec(sk->sk_prot->orphan_count);
631 sock_put(sk);
632}
633
634EXPORT_SYMBOL(inet_csk_destroy_sock);
635
636int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
637{
638 struct inet_sock *inet = inet_sk(sk);
639 struct inet_connection_sock *icsk = inet_csk(sk);
640 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
641
642 if (rc != 0)
643 return rc;
644
645 sk->sk_max_ack_backlog = 0;
646 sk->sk_ack_backlog = 0;
647 inet_csk_delack_init(sk);
648
649
650
651
652
653
654 sk->sk_state = TCP_LISTEN;
655 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
656 inet->inet_sport = htons(inet->inet_num);
657
658 sk_dst_reset(sk);
659 sk->sk_prot->hash(sk);
660
661 return 0;
662 }
663
664 sk->sk_state = TCP_CLOSE;
665 __reqsk_queue_destroy(&icsk->icsk_accept_queue);
666 return -EADDRINUSE;
667}
668
669EXPORT_SYMBOL_GPL(inet_csk_listen_start);
670
671
672
673
674
675void inet_csk_listen_stop(struct sock *sk)
676{
677 struct inet_connection_sock *icsk = inet_csk(sk);
678 struct request_sock *acc_req;
679 struct request_sock *req;
680
681 inet_csk_delete_keepalive_timer(sk);
682
683
684 acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
685
686
687
688
689
690
691
692
693
694 reqsk_queue_destroy(&icsk->icsk_accept_queue);
695
696 while ((req = acc_req) != NULL) {
697 struct sock *child = req->sk;
698
699 acc_req = req->dl_next;
700
701 local_bh_disable();
702 bh_lock_sock(child);
703 WARN_ON(sock_owned_by_user(child));
704 sock_hold(child);
705
706 sk->sk_prot->disconnect(child, O_NONBLOCK);
707
708 sock_orphan(child);
709
710 percpu_counter_inc(sk->sk_prot->orphan_count);
711
712 inet_csk_destroy_sock(child);
713
714 bh_unlock_sock(child);
715 local_bh_enable();
716 sock_put(child);
717
718 sk_acceptq_removed(sk);
719 __reqsk_free(req);
720 }
721 WARN_ON(sk->sk_ack_backlog);
722}
723
724EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
725
726void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
727{
728 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
729 const struct inet_sock *inet = inet_sk(sk);
730
731 sin->sin_family = AF_INET;
732 sin->sin_addr.s_addr = inet->inet_daddr;
733 sin->sin_port = inet->inet_dport;
734}
735
736EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
737
738#ifdef CONFIG_COMPAT
739int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
740 char __user *optval, int __user *optlen)
741{
742 const struct inet_connection_sock *icsk = inet_csk(sk);
743
744 if (icsk->icsk_af_ops->compat_getsockopt != NULL)
745 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
746 optval, optlen);
747 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
748 optval, optlen);
749}
750
751EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
752
753int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
754 char __user *optval, unsigned int optlen)
755{
756 const struct inet_connection_sock *icsk = inet_csk(sk);
757
758 if (icsk->icsk_af_ops->compat_setsockopt != NULL)
759 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
760 optval, optlen);
761 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
762 optval, optlen);
763}
764
765EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
766#endif
767