inet_connection_sock.c revision 8d238b25b1ec22a73b1c2206f111df2faaff8285
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
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 * This struct holds the first and last local port number.
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	 * Unlike other sk lookup places we do not check
62	 * for sk_net here, since _all_ the socks listed
63	 * in tb->owners list belong to the same net - the
64	 * one this bucket belongs to.
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/* Obtain a reference to a local port for the given sock,
88 * if snum is zero it means select any available local port.
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 (net_eq(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		/* Exhausted local port range during search?  It is not
138		 * possible for us to be holding one of the bind hash
139		 * locks if this test triggers, because if 'remaining'
140		 * drops to zero, we broke out of the do/while loop at
141		 * the top level, not from the 'break;' statement.
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		/* OK, here is the one we will use.  HEAD is
152		 * non-NULL and we hold it's mutex.
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 (net_eq(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 * Wait for an incoming connection, avoid race conditions. This must be called
214 * with the socket locked.
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
222	/*
223	 * True wake-one mechanism for incoming connections: only
224	 * one process gets woken up, not the 'whole herd'.
225	 * Since we do not 'race & poll' for established sockets
226	 * anymore, the common case will execute the loop only once.
227	 *
228	 * Subtle issue: "add_wait_queue_exclusive()" will be added
229	 * after any current non-exclusive waiters, and we know that
230	 * it will always _stay_ after any new non-exclusive waiters
231	 * because all non-exclusive waiters are added at the
232	 * beginning of the wait-queue. As such, it's ok to "drop"
233	 * our exclusiveness temporarily when we get woken up without
234	 * having to remove and re-insert us on the wait queue.
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 * This will accept the next outstanding connection.
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	/* We need to make sure that this socket is listening,
272	 * and that it has something pending.
273	 */
274	error = -EINVAL;
275	if (sk->sk_state != TCP_LISTEN)
276		goto out_err;
277
278	/* Find already established connection */
279	if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
280		long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
281
282		/* If this is a non blocking socket don't sleep */
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 * Using different timers for retransmit, delayed acks and probes
307 * We may wish use just one timer maintaining a list of expire jiffies
308 * to optimize.
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			    .mark = sk->sk_mark,
362			    .nl_u = { .ip4_u =
363				      { .daddr = ((opt && opt->srr) ?
364						  opt->faddr :
365						  ireq->rmt_addr),
366					.saddr = ireq->loc_addr,
367					.tos = RT_CONN_FLAGS(sk) } },
368			    .proto = sk->sk_protocol,
369			    .flags = inet_sk_flowi_flags(sk),
370			    .uli_u = { .ports =
371				       { .sport = inet_sk(sk)->inet_sport,
372					 .dport = ireq->rmt_port } } };
373	struct net *net = sock_net(sk);
374
375	security_req_classify_flow(req, &fl);
376	if (ip_route_output_flow(net, &rt, &fl, sk, 0))
377		goto no_route;
378	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
379		goto route_err;
380	return &rt->u.dst;
381
382route_err:
383	ip_rt_put(rt);
384no_route:
385	IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
386	return NULL;
387}
388
389EXPORT_SYMBOL_GPL(inet_csk_route_req);
390
391static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
392				 const u32 rnd, const u32 synq_hsize)
393{
394	return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
395}
396
397#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
398#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
399#else
400#define AF_INET_FAMILY(fam) 1
401#endif
402
403struct request_sock *inet_csk_search_req(const struct sock *sk,
404					 struct request_sock ***prevp,
405					 const __be16 rport, const __be32 raddr,
406					 const __be32 laddr)
407{
408	const struct inet_connection_sock *icsk = inet_csk(sk);
409	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
410	struct request_sock *req, **prev;
411
412	for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
413						    lopt->nr_table_entries)];
414	     (req = *prev) != NULL;
415	     prev = &req->dl_next) {
416		const struct inet_request_sock *ireq = inet_rsk(req);
417
418		if (ireq->rmt_port == rport &&
419		    ireq->rmt_addr == raddr &&
420		    ireq->loc_addr == laddr &&
421		    AF_INET_FAMILY(req->rsk_ops->family)) {
422			WARN_ON(req->sk);
423			*prevp = prev;
424			break;
425		}
426	}
427
428	return req;
429}
430
431EXPORT_SYMBOL_GPL(inet_csk_search_req);
432
433void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
434				   unsigned long timeout)
435{
436	struct inet_connection_sock *icsk = inet_csk(sk);
437	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
438	const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
439				     lopt->hash_rnd, lopt->nr_table_entries);
440
441	reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
442	inet_csk_reqsk_queue_added(sk, timeout);
443}
444
445/* Only thing we need from tcp.h */
446extern int sysctl_tcp_synack_retries;
447
448EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
449
450/* Decide when to expire the request and when to resend SYN-ACK */
451static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
452				  const int max_retries,
453				  const u8 rskq_defer_accept,
454				  int *expire, int *resend)
455{
456	if (!rskq_defer_accept) {
457		*expire = req->retrans >= thresh;
458		*resend = 1;
459		return;
460	}
461	*expire = req->retrans >= thresh &&
462		  (!inet_rsk(req)->acked || req->retrans >= max_retries);
463	/*
464	 * Do not resend while waiting for data after ACK,
465	 * start to resend on end of deferring period to give
466	 * last chance for data or ACK to create established socket.
467	 */
468	*resend = !inet_rsk(req)->acked ||
469		  req->retrans >= rskq_defer_accept - 1;
470}
471
472void inet_csk_reqsk_queue_prune(struct sock *parent,
473				const unsigned long interval,
474				const unsigned long timeout,
475				const unsigned long max_rto)
476{
477	struct inet_connection_sock *icsk = inet_csk(parent);
478	struct request_sock_queue *queue = &icsk->icsk_accept_queue;
479	struct listen_sock *lopt = queue->listen_opt;
480	int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
481	int thresh = max_retries;
482	unsigned long now = jiffies;
483	struct request_sock **reqp, *req;
484	int i, budget;
485
486	if (lopt == NULL || lopt->qlen == 0)
487		return;
488
489	/* Normally all the openreqs are young and become mature
490	 * (i.e. converted to established socket) for first timeout.
491	 * If synack was not acknowledged for 3 seconds, it means
492	 * one of the following things: synack was lost, ack was lost,
493	 * rtt is high or nobody planned to ack (i.e. synflood).
494	 * When server is a bit loaded, queue is populated with old
495	 * open requests, reducing effective size of queue.
496	 * When server is well loaded, queue size reduces to zero
497	 * after several minutes of work. It is not synflood,
498	 * it is normal operation. The solution is pruning
499	 * too old entries overriding normal timeout, when
500	 * situation becomes dangerous.
501	 *
502	 * Essentially, we reserve half of room for young
503	 * embrions; and abort old ones without pity, if old
504	 * ones are about to clog our table.
505	 */
506	if (lopt->qlen>>(lopt->max_qlen_log-1)) {
507		int young = (lopt->qlen_young<<1);
508
509		while (thresh > 2) {
510			if (lopt->qlen < young)
511				break;
512			thresh--;
513			young <<= 1;
514		}
515	}
516
517	if (queue->rskq_defer_accept)
518		max_retries = queue->rskq_defer_accept;
519
520	budget = 2 * (lopt->nr_table_entries / (timeout / interval));
521	i = lopt->clock_hand;
522
523	do {
524		reqp=&lopt->syn_table[i];
525		while ((req = *reqp) != NULL) {
526			if (time_after_eq(now, req->expires)) {
527				int expire = 0, resend = 0;
528
529				syn_ack_recalc(req, thresh, max_retries,
530					       queue->rskq_defer_accept,
531					       &expire, &resend);
532				if (req->rsk_ops->syn_ack_timeout)
533					req->rsk_ops->syn_ack_timeout(parent, req);
534				if (!expire &&
535				    (!resend ||
536				     !req->rsk_ops->rtx_syn_ack(parent, req, NULL) ||
537				     inet_rsk(req)->acked)) {
538					unsigned long timeo;
539
540					if (req->retrans++ == 0)
541						lopt->qlen_young--;
542					timeo = min((timeout << req->retrans), max_rto);
543					req->expires = now + timeo;
544					reqp = &req->dl_next;
545					continue;
546				}
547
548				/* Drop this request */
549				inet_csk_reqsk_queue_unlink(parent, req, reqp);
550				reqsk_queue_removed(queue, req);
551				reqsk_free(req);
552				continue;
553			}
554			reqp = &req->dl_next;
555		}
556
557		i = (i + 1) & (lopt->nr_table_entries - 1);
558
559	} while (--budget > 0);
560
561	lopt->clock_hand = i;
562
563	if (lopt->qlen)
564		inet_csk_reset_keepalive_timer(parent, interval);
565}
566
567EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
568
569struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
570			    const gfp_t priority)
571{
572	struct sock *newsk = sk_clone(sk, priority);
573
574	if (newsk != NULL) {
575		struct inet_connection_sock *newicsk = inet_csk(newsk);
576
577		newsk->sk_state = TCP_SYN_RECV;
578		newicsk->icsk_bind_hash = NULL;
579
580		inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port;
581		inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port);
582		inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port;
583		newsk->sk_write_space = sk_stream_write_space;
584
585		newicsk->icsk_retransmits = 0;
586		newicsk->icsk_backoff	  = 0;
587		newicsk->icsk_probes_out  = 0;
588
589		/* Deinitialize accept_queue to trap illegal accesses. */
590		memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
591
592		security_inet_csk_clone(newsk, req);
593	}
594	return newsk;
595}
596
597EXPORT_SYMBOL_GPL(inet_csk_clone);
598
599/*
600 * At this point, there should be no process reference to this
601 * socket, and thus no user references at all.  Therefore we
602 * can assume the socket waitqueue is inactive and nobody will
603 * try to jump onto it.
604 */
605void inet_csk_destroy_sock(struct sock *sk)
606{
607	WARN_ON(sk->sk_state != TCP_CLOSE);
608	WARN_ON(!sock_flag(sk, SOCK_DEAD));
609
610	/* It cannot be in hash table! */
611	WARN_ON(!sk_unhashed(sk));
612
613	/* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
614	WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
615
616	sk->sk_prot->destroy(sk);
617
618	sk_stream_kill_queues(sk);
619
620	xfrm_sk_free_policy(sk);
621
622	sk_refcnt_debug_release(sk);
623
624	percpu_counter_dec(sk->sk_prot->orphan_count);
625	sock_put(sk);
626}
627
628EXPORT_SYMBOL(inet_csk_destroy_sock);
629
630int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
631{
632	struct inet_sock *inet = inet_sk(sk);
633	struct inet_connection_sock *icsk = inet_csk(sk);
634	int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
635
636	if (rc != 0)
637		return rc;
638
639	sk->sk_max_ack_backlog = 0;
640	sk->sk_ack_backlog = 0;
641	inet_csk_delack_init(sk);
642
643	/* There is race window here: we announce ourselves listening,
644	 * but this transition is still not validated by get_port().
645	 * It is OK, because this socket enters to hash table only
646	 * after validation is complete.
647	 */
648	sk->sk_state = TCP_LISTEN;
649	if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
650		inet->inet_sport = htons(inet->inet_num);
651
652		sk_dst_reset(sk);
653		sk->sk_prot->hash(sk);
654
655		return 0;
656	}
657
658	sk->sk_state = TCP_CLOSE;
659	__reqsk_queue_destroy(&icsk->icsk_accept_queue);
660	return -EADDRINUSE;
661}
662
663EXPORT_SYMBOL_GPL(inet_csk_listen_start);
664
665/*
666 *	This routine closes sockets which have been at least partially
667 *	opened, but not yet accepted.
668 */
669void inet_csk_listen_stop(struct sock *sk)
670{
671	struct inet_connection_sock *icsk = inet_csk(sk);
672	struct request_sock *acc_req;
673	struct request_sock *req;
674
675	inet_csk_delete_keepalive_timer(sk);
676
677	/* make all the listen_opt local to us */
678	acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
679
680	/* Following specs, it would be better either to send FIN
681	 * (and enter FIN-WAIT-1, it is normal close)
682	 * or to send active reset (abort).
683	 * Certainly, it is pretty dangerous while synflood, but it is
684	 * bad justification for our negligence 8)
685	 * To be honest, we are not able to make either
686	 * of the variants now.			--ANK
687	 */
688	reqsk_queue_destroy(&icsk->icsk_accept_queue);
689
690	while ((req = acc_req) != NULL) {
691		struct sock *child = req->sk;
692
693		acc_req = req->dl_next;
694
695		local_bh_disable();
696		bh_lock_sock(child);
697		WARN_ON(sock_owned_by_user(child));
698		sock_hold(child);
699
700		sk->sk_prot->disconnect(child, O_NONBLOCK);
701
702		sock_orphan(child);
703
704		percpu_counter_inc(sk->sk_prot->orphan_count);
705
706		inet_csk_destroy_sock(child);
707
708		bh_unlock_sock(child);
709		local_bh_enable();
710		sock_put(child);
711
712		sk_acceptq_removed(sk);
713		__reqsk_free(req);
714	}
715	WARN_ON(sk->sk_ack_backlog);
716}
717
718EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
719
720void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
721{
722	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
723	const struct inet_sock *inet = inet_sk(sk);
724
725	sin->sin_family		= AF_INET;
726	sin->sin_addr.s_addr	= inet->inet_daddr;
727	sin->sin_port		= inet->inet_dport;
728}
729
730EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
731
732#ifdef CONFIG_COMPAT
733int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
734			       char __user *optval, int __user *optlen)
735{
736	const struct inet_connection_sock *icsk = inet_csk(sk);
737
738	if (icsk->icsk_af_ops->compat_getsockopt != NULL)
739		return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
740							    optval, optlen);
741	return icsk->icsk_af_ops->getsockopt(sk, level, optname,
742					     optval, optlen);
743}
744
745EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
746
747int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
748			       char __user *optval, unsigned int optlen)
749{
750	const struct inet_connection_sock *icsk = inet_csk(sk);
751
752	if (icsk->icsk_af_ops->compat_setsockopt != NULL)
753		return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
754							    optval, optlen);
755	return icsk->icsk_af_ops->setsockopt(sk, level, optname,
756					     optval, optlen);
757}
758
759EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
760#endif
761