Merge git://git.infradead.org/hdrinstall-2.6
[linux-2.6] / 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 /*
33  * This array holds the first and last local port number.
34  * For high-usage systems, use sysctl to change this to
35  * 32768-61000
36  */
37 int sysctl_local_port_range[2] = { 1024, 4999 };
38
39 int inet_csk_bind_conflict(const struct sock *sk,
40                            const struct inet_bind_bucket *tb)
41 {
42         const u32 sk_rcv_saddr = inet_rcv_saddr(sk);
43         struct sock *sk2;
44         struct hlist_node *node;
45         int reuse = sk->sk_reuse;
46
47         sk_for_each_bound(sk2, node, &tb->owners) {
48                 if (sk != sk2 &&
49                     !inet_v6_ipv6only(sk2) &&
50                     (!sk->sk_bound_dev_if ||
51                      !sk2->sk_bound_dev_if ||
52                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
53                         if (!reuse || !sk2->sk_reuse ||
54                             sk2->sk_state == TCP_LISTEN) {
55                                 const u32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
56                                 if (!sk2_rcv_saddr || !sk_rcv_saddr ||
57                                     sk2_rcv_saddr == sk_rcv_saddr)
58                                         break;
59                         }
60                 }
61         }
62         return node != NULL;
63 }
64
65 EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
66
67 /* Obtain a reference to a local port for the given sock,
68  * if snum is zero it means select any available local port.
69  */
70 int inet_csk_get_port(struct inet_hashinfo *hashinfo,
71                       struct sock *sk, unsigned short snum,
72                       int (*bind_conflict)(const struct sock *sk,
73                                            const struct inet_bind_bucket *tb))
74 {
75         struct inet_bind_hashbucket *head;
76         struct hlist_node *node;
77         struct inet_bind_bucket *tb;
78         int ret;
79
80         local_bh_disable();
81         if (!snum) {
82                 int low = sysctl_local_port_range[0];
83                 int high = sysctl_local_port_range[1];
84                 int remaining = (high - low) + 1;
85                 int rover = net_random() % (high - low) + low;
86
87                 do {
88                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
89                         spin_lock(&head->lock);
90                         inet_bind_bucket_for_each(tb, node, &head->chain)
91                                 if (tb->port == rover)
92                                         goto next;
93                         break;
94                 next:
95                         spin_unlock(&head->lock);
96                         if (++rover > high)
97                                 rover = low;
98                 } while (--remaining > 0);
99
100                 /* Exhausted local port range during search?  It is not
101                  * possible for us to be holding one of the bind hash
102                  * locks if this test triggers, because if 'remaining'
103                  * drops to zero, we broke out of the do/while loop at
104                  * the top level, not from the 'break;' statement.
105                  */
106                 ret = 1;
107                 if (remaining <= 0)
108                         goto fail;
109
110                 /* OK, here is the one we will use.  HEAD is
111                  * non-NULL and we hold it's mutex.
112                  */
113                 snum = rover;
114         } else {
115                 head = &hashinfo->bhash[inet_bhashfn(snum, hashinfo->bhash_size)];
116                 spin_lock(&head->lock);
117                 inet_bind_bucket_for_each(tb, node, &head->chain)
118                         if (tb->port == snum)
119                                 goto tb_found;
120         }
121         tb = NULL;
122         goto tb_not_found;
123 tb_found:
124         if (!hlist_empty(&tb->owners)) {
125                 if (sk->sk_reuse > 1)
126                         goto success;
127                 if (tb->fastreuse > 0 &&
128                     sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
129                         goto success;
130                 } else {
131                         ret = 1;
132                         if (bind_conflict(sk, tb))
133                                 goto fail_unlock;
134                 }
135         }
136 tb_not_found:
137         ret = 1;
138         if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, head, snum)) == NULL)
139                 goto fail_unlock;
140         if (hlist_empty(&tb->owners)) {
141                 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
142                         tb->fastreuse = 1;
143                 else
144                         tb->fastreuse = 0;
145         } else if (tb->fastreuse &&
146                    (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
147                 tb->fastreuse = 0;
148 success:
149         if (!inet_csk(sk)->icsk_bind_hash)
150                 inet_bind_hash(sk, tb, snum);
151         BUG_TRAP(inet_csk(sk)->icsk_bind_hash == tb);
152         ret = 0;
153
154 fail_unlock:
155         spin_unlock(&head->lock);
156 fail:
157         local_bh_enable();
158         return ret;
159 }
160
161 EXPORT_SYMBOL_GPL(inet_csk_get_port);
162
163 /*
164  * Wait for an incoming connection, avoid race conditions. This must be called
165  * with the socket locked.
166  */
167 static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
168 {
169         struct inet_connection_sock *icsk = inet_csk(sk);
170         DEFINE_WAIT(wait);
171         int err;
172
173         /*
174          * True wake-one mechanism for incoming connections: only
175          * one process gets woken up, not the 'whole herd'.
176          * Since we do not 'race & poll' for established sockets
177          * anymore, the common case will execute the loop only once.
178          *
179          * Subtle issue: "add_wait_queue_exclusive()" will be added
180          * after any current non-exclusive waiters, and we know that
181          * it will always _stay_ after any new non-exclusive waiters
182          * because all non-exclusive waiters are added at the
183          * beginning of the wait-queue. As such, it's ok to "drop"
184          * our exclusiveness temporarily when we get woken up without
185          * having to remove and re-insert us on the wait queue.
186          */
187         for (;;) {
188                 prepare_to_wait_exclusive(sk->sk_sleep, &wait,
189                                           TASK_INTERRUPTIBLE);
190                 release_sock(sk);
191                 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
192                         timeo = schedule_timeout(timeo);
193                 lock_sock(sk);
194                 err = 0;
195                 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
196                         break;
197                 err = -EINVAL;
198                 if (sk->sk_state != TCP_LISTEN)
199                         break;
200                 err = sock_intr_errno(timeo);
201                 if (signal_pending(current))
202                         break;
203                 err = -EAGAIN;
204                 if (!timeo)
205                         break;
206         }
207         finish_wait(sk->sk_sleep, &wait);
208         return err;
209 }
210
211 /*
212  * This will accept the next outstanding connection.
213  */
214 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
215 {
216         struct inet_connection_sock *icsk = inet_csk(sk);
217         struct sock *newsk;
218         int error;
219
220         lock_sock(sk);
221
222         /* We need to make sure that this socket is listening,
223          * and that it has something pending.
224          */
225         error = -EINVAL;
226         if (sk->sk_state != TCP_LISTEN)
227                 goto out_err;
228
229         /* Find already established connection */
230         if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
231                 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
232
233                 /* If this is a non blocking socket don't sleep */
234                 error = -EAGAIN;
235                 if (!timeo)
236                         goto out_err;
237
238                 error = inet_csk_wait_for_connect(sk, timeo);
239                 if (error)
240                         goto out_err;
241         }
242
243         newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
244         BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
245 out:
246         release_sock(sk);
247         return newsk;
248 out_err:
249         newsk = NULL;
250         *err = error;
251         goto out;
252 }
253
254 EXPORT_SYMBOL(inet_csk_accept);
255
256 /*
257  * Using different timers for retransmit, delayed acks and probes
258  * We may wish use just one timer maintaining a list of expire jiffies 
259  * to optimize.
260  */
261 void inet_csk_init_xmit_timers(struct sock *sk,
262                                void (*retransmit_handler)(unsigned long),
263                                void (*delack_handler)(unsigned long),
264                                void (*keepalive_handler)(unsigned long))
265 {
266         struct inet_connection_sock *icsk = inet_csk(sk);
267
268         init_timer(&icsk->icsk_retransmit_timer);
269         init_timer(&icsk->icsk_delack_timer);
270         init_timer(&sk->sk_timer);
271
272         icsk->icsk_retransmit_timer.function = retransmit_handler;
273         icsk->icsk_delack_timer.function     = delack_handler;
274         sk->sk_timer.function                = keepalive_handler;
275
276         icsk->icsk_retransmit_timer.data = 
277                 icsk->icsk_delack_timer.data =
278                         sk->sk_timer.data  = (unsigned long)sk;
279
280         icsk->icsk_pending = icsk->icsk_ack.pending = 0;
281 }
282
283 EXPORT_SYMBOL(inet_csk_init_xmit_timers);
284
285 void inet_csk_clear_xmit_timers(struct sock *sk)
286 {
287         struct inet_connection_sock *icsk = inet_csk(sk);
288
289         icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
290
291         sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
292         sk_stop_timer(sk, &icsk->icsk_delack_timer);
293         sk_stop_timer(sk, &sk->sk_timer);
294 }
295
296 EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
297
298 void inet_csk_delete_keepalive_timer(struct sock *sk)
299 {
300         sk_stop_timer(sk, &sk->sk_timer);
301 }
302
303 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
304
305 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
306 {
307         sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
308 }
309
310 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
311
312 struct dst_entry* inet_csk_route_req(struct sock *sk,
313                                      const struct request_sock *req)
314 {
315         struct rtable *rt;
316         const struct inet_request_sock *ireq = inet_rsk(req);
317         struct ip_options *opt = inet_rsk(req)->opt;
318         struct flowi fl = { .oif = sk->sk_bound_dev_if,
319                             .nl_u = { .ip4_u =
320                                       { .daddr = ((opt && opt->srr) ?
321                                                   opt->faddr :
322                                                   ireq->rmt_addr),
323                                         .saddr = ireq->loc_addr,
324                                         .tos = RT_CONN_FLAGS(sk) } },
325                             .proto = sk->sk_protocol,
326                             .uli_u = { .ports =
327                                        { .sport = inet_sk(sk)->sport,
328                                          .dport = ireq->rmt_port } } };
329
330         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
331                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
332                 return NULL;
333         }
334         if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
335                 ip_rt_put(rt);
336                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
337                 return NULL;
338         }
339         return &rt->u.dst;
340 }
341
342 EXPORT_SYMBOL_GPL(inet_csk_route_req);
343
344 static inline u32 inet_synq_hash(const u32 raddr, const u16 rport,
345                                  const u32 rnd, const u16 synq_hsize)
346 {
347         return jhash_2words(raddr, (u32)rport, rnd) & (synq_hsize - 1);
348 }
349
350 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
351 #define AF_INET_FAMILY(fam) ((fam) == AF_INET)
352 #else
353 #define AF_INET_FAMILY(fam) 1
354 #endif
355
356 struct request_sock *inet_csk_search_req(const struct sock *sk,
357                                          struct request_sock ***prevp,
358                                          const __u16 rport, const __u32 raddr,
359                                          const __u32 laddr)
360 {
361         const struct inet_connection_sock *icsk = inet_csk(sk);
362         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
363         struct request_sock *req, **prev;
364
365         for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
366                                                     lopt->nr_table_entries)];
367              (req = *prev) != NULL;
368              prev = &req->dl_next) {
369                 const struct inet_request_sock *ireq = inet_rsk(req);
370
371                 if (ireq->rmt_port == rport &&
372                     ireq->rmt_addr == raddr &&
373                     ireq->loc_addr == laddr &&
374                     AF_INET_FAMILY(req->rsk_ops->family)) {
375                         BUG_TRAP(!req->sk);
376                         *prevp = prev;
377                         break;
378                 }
379         }
380
381         return req;
382 }
383
384 EXPORT_SYMBOL_GPL(inet_csk_search_req);
385
386 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
387                                    unsigned long timeout)
388 {
389         struct inet_connection_sock *icsk = inet_csk(sk);
390         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
391         const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
392                                      lopt->hash_rnd, lopt->nr_table_entries);
393
394         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
395         inet_csk_reqsk_queue_added(sk, timeout);
396 }
397
398 /* Only thing we need from tcp.h */
399 extern int sysctl_tcp_synack_retries;
400
401 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
402
403 void inet_csk_reqsk_queue_prune(struct sock *parent,
404                                 const unsigned long interval,
405                                 const unsigned long timeout,
406                                 const unsigned long max_rto)
407 {
408         struct inet_connection_sock *icsk = inet_csk(parent);
409         struct request_sock_queue *queue = &icsk->icsk_accept_queue;
410         struct listen_sock *lopt = queue->listen_opt;
411         int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
412         int thresh = max_retries;
413         unsigned long now = jiffies;
414         struct request_sock **reqp, *req;
415         int i, budget;
416
417         if (lopt == NULL || lopt->qlen == 0)
418                 return;
419
420         /* Normally all the openreqs are young and become mature
421          * (i.e. converted to established socket) for first timeout.
422          * If synack was not acknowledged for 3 seconds, it means
423          * one of the following things: synack was lost, ack was lost,
424          * rtt is high or nobody planned to ack (i.e. synflood).
425          * When server is a bit loaded, queue is populated with old
426          * open requests, reducing effective size of queue.
427          * When server is well loaded, queue size reduces to zero
428          * after several minutes of work. It is not synflood,
429          * it is normal operation. The solution is pruning
430          * too old entries overriding normal timeout, when
431          * situation becomes dangerous.
432          *
433          * Essentially, we reserve half of room for young
434          * embrions; and abort old ones without pity, if old
435          * ones are about to clog our table.
436          */
437         if (lopt->qlen>>(lopt->max_qlen_log-1)) {
438                 int young = (lopt->qlen_young<<1);
439
440                 while (thresh > 2) {
441                         if (lopt->qlen < young)
442                                 break;
443                         thresh--;
444                         young <<= 1;
445                 }
446         }
447
448         if (queue->rskq_defer_accept)
449                 max_retries = queue->rskq_defer_accept;
450
451         budget = 2 * (lopt->nr_table_entries / (timeout / interval));
452         i = lopt->clock_hand;
453
454         do {
455                 reqp=&lopt->syn_table[i];
456                 while ((req = *reqp) != NULL) {
457                         if (time_after_eq(now, req->expires)) {
458                                 if ((req->retrans < thresh ||
459                                      (inet_rsk(req)->acked && req->retrans < max_retries))
460                                     && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
461                                         unsigned long timeo;
462
463                                         if (req->retrans++ == 0)
464                                                 lopt->qlen_young--;
465                                         timeo = min((timeout << req->retrans), max_rto);
466                                         req->expires = now + timeo;
467                                         reqp = &req->dl_next;
468                                         continue;
469                                 }
470
471                                 /* Drop this request */
472                                 inet_csk_reqsk_queue_unlink(parent, req, reqp);
473                                 reqsk_queue_removed(queue, req);
474                                 reqsk_free(req);
475                                 continue;
476                         }
477                         reqp = &req->dl_next;
478                 }
479
480                 i = (i + 1) & (lopt->nr_table_entries - 1);
481
482         } while (--budget > 0);
483
484         lopt->clock_hand = i;
485
486         if (lopt->qlen)
487                 inet_csk_reset_keepalive_timer(parent, interval);
488 }
489
490 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
491
492 struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
493                             const gfp_t priority)
494 {
495         struct sock *newsk = sk_clone(sk, priority);
496
497         if (newsk != NULL) {
498                 struct inet_connection_sock *newicsk = inet_csk(newsk);
499
500                 newsk->sk_state = TCP_SYN_RECV;
501                 newicsk->icsk_bind_hash = NULL;
502
503                 inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
504                 newsk->sk_write_space = sk_stream_write_space;
505
506                 newicsk->icsk_retransmits = 0;
507                 newicsk->icsk_backoff     = 0;
508                 newicsk->icsk_probes_out  = 0;
509
510                 /* Deinitialize accept_queue to trap illegal accesses. */
511                 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
512         }
513         return newsk;
514 }
515
516 EXPORT_SYMBOL_GPL(inet_csk_clone);
517
518 /*
519  * At this point, there should be no process reference to this
520  * socket, and thus no user references at all.  Therefore we
521  * can assume the socket waitqueue is inactive and nobody will
522  * try to jump onto it.
523  */
524 void inet_csk_destroy_sock(struct sock *sk)
525 {
526         BUG_TRAP(sk->sk_state == TCP_CLOSE);
527         BUG_TRAP(sock_flag(sk, SOCK_DEAD));
528
529         /* It cannot be in hash table! */
530         BUG_TRAP(sk_unhashed(sk));
531
532         /* If it has not 0 inet_sk(sk)->num, it must be bound */
533         BUG_TRAP(!inet_sk(sk)->num || inet_csk(sk)->icsk_bind_hash);
534
535         sk->sk_prot->destroy(sk);
536
537         sk_stream_kill_queues(sk);
538
539         xfrm_sk_free_policy(sk);
540
541         sk_refcnt_debug_release(sk);
542
543         atomic_dec(sk->sk_prot->orphan_count);
544         sock_put(sk);
545 }
546
547 EXPORT_SYMBOL(inet_csk_destroy_sock);
548
549 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
550 {
551         struct inet_sock *inet = inet_sk(sk);
552         struct inet_connection_sock *icsk = inet_csk(sk);
553         int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
554
555         if (rc != 0)
556                 return rc;
557
558         sk->sk_max_ack_backlog = 0;
559         sk->sk_ack_backlog = 0;
560         inet_csk_delack_init(sk);
561
562         /* There is race window here: we announce ourselves listening,
563          * but this transition is still not validated by get_port().
564          * It is OK, because this socket enters to hash table only
565          * after validation is complete.
566          */
567         sk->sk_state = TCP_LISTEN;
568         if (!sk->sk_prot->get_port(sk, inet->num)) {
569                 inet->sport = htons(inet->num);
570
571                 sk_dst_reset(sk);
572                 sk->sk_prot->hash(sk);
573
574                 return 0;
575         }
576
577         sk->sk_state = TCP_CLOSE;
578         __reqsk_queue_destroy(&icsk->icsk_accept_queue);
579         return -EADDRINUSE;
580 }
581
582 EXPORT_SYMBOL_GPL(inet_csk_listen_start);
583
584 /*
585  *      This routine closes sockets which have been at least partially
586  *      opened, but not yet accepted.
587  */
588 void inet_csk_listen_stop(struct sock *sk)
589 {
590         struct inet_connection_sock *icsk = inet_csk(sk);
591         struct request_sock *acc_req;
592         struct request_sock *req;
593
594         inet_csk_delete_keepalive_timer(sk);
595
596         /* make all the listen_opt local to us */
597         acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
598
599         /* Following specs, it would be better either to send FIN
600          * (and enter FIN-WAIT-1, it is normal close)
601          * or to send active reset (abort).
602          * Certainly, it is pretty dangerous while synflood, but it is
603          * bad justification for our negligence 8)
604          * To be honest, we are not able to make either
605          * of the variants now.                 --ANK
606          */
607         reqsk_queue_destroy(&icsk->icsk_accept_queue);
608
609         while ((req = acc_req) != NULL) {
610                 struct sock *child = req->sk;
611
612                 acc_req = req->dl_next;
613
614                 local_bh_disable();
615                 bh_lock_sock(child);
616                 BUG_TRAP(!sock_owned_by_user(child));
617                 sock_hold(child);
618
619                 sk->sk_prot->disconnect(child, O_NONBLOCK);
620
621                 sock_orphan(child);
622
623                 atomic_inc(sk->sk_prot->orphan_count);
624
625                 inet_csk_destroy_sock(child);
626
627                 bh_unlock_sock(child);
628                 local_bh_enable();
629                 sock_put(child);
630
631                 sk_acceptq_removed(sk);
632                 __reqsk_free(req);
633         }
634         BUG_TRAP(!sk->sk_ack_backlog);
635 }
636
637 EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
638
639 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
640 {
641         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
642         const struct inet_sock *inet = inet_sk(sk);
643
644         sin->sin_family         = AF_INET;
645         sin->sin_addr.s_addr    = inet->daddr;
646         sin->sin_port           = inet->dport;
647 }
648
649 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
650
651 int inet_csk_ctl_sock_create(struct socket **sock, unsigned short family,
652                              unsigned short type, unsigned char protocol)
653 {
654         int rc = sock_create_kern(family, type, protocol, sock);
655
656         if (rc == 0) {
657                 (*sock)->sk->sk_allocation = GFP_ATOMIC;
658                 inet_sk((*sock)->sk)->uc_ttl = -1;
659                 /*
660                  * Unhash it so that IP input processing does not even see it,
661                  * we do not wish this socket to see incoming packets.
662                  */
663                 (*sock)->sk->sk_prot->unhash((*sock)->sk);
664         }
665         return rc;
666 }
667
668 EXPORT_SYMBOL_GPL(inet_csk_ctl_sock_create);
669
670 #ifdef CONFIG_COMPAT
671 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
672                                char __user *optval, int __user *optlen)
673 {
674         const struct inet_connection_sock *icsk = inet_csk(sk);
675
676         if (icsk->icsk_af_ops->compat_getsockopt != NULL)
677                 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
678                                                             optval, optlen);
679         return icsk->icsk_af_ops->getsockopt(sk, level, optname,
680                                              optval, optlen);
681 }
682
683 EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
684
685 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
686                                char __user *optval, int optlen)
687 {
688         const struct inet_connection_sock *icsk = inet_csk(sk);
689
690         if (icsk->icsk_af_ops->compat_setsockopt != NULL)
691                 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
692                                                             optval, optlen);
693         return icsk->icsk_af_ops->setsockopt(sk, level, optname,
694                                              optval, optlen);
695 }
696
697 EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
698 #endif