blob: 3a2ba5632dffbc0f925d8b21d7c97f8f5b68d5ad [file] [log] [blame]
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -07001/*
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
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070016#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>
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -070025#include <net/xfrm.h>
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070026
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/*
Eric Dumazet3c689b72008-10-08 14:18:04 -070033 * This struct holds the first and last local port number.
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070034 */
Eric Dumazet3c689b72008-10-08 14:18:04 -070035struct local_ports sysctl_local_ports __read_mostly = {
36 .lock = SEQLOCK_UNLOCKED,
37 .range = { 32768, 61000 },
38};
Stephen Hemminger227b60f2007-10-10 17:30:46 -070039
Amerigo Wange3826f12010-05-05 00:27:06 +000040unsigned long *sysctl_local_reserved_ports;
41EXPORT_SYMBOL(sysctl_local_reserved_ports);
42
Stephen Hemminger227b60f2007-10-10 17:30:46 -070043void inet_get_local_port_range(int *low, int *high)
44{
45 unsigned seq;
46 do {
Eric Dumazet3c689b72008-10-08 14:18:04 -070047 seq = read_seqbegin(&sysctl_local_ports.lock);
Stephen Hemminger227b60f2007-10-10 17:30:46 -070048
Eric Dumazet3c689b72008-10-08 14:18:04 -070049 *low = sysctl_local_ports.range[0];
50 *high = sysctl_local_ports.range[1];
51 } while (read_seqretry(&sysctl_local_ports.lock, seq));
Stephen Hemminger227b60f2007-10-10 17:30:46 -070052}
53EXPORT_SYMBOL(inet_get_local_port_range);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070054
Arnaldo Carvalho de Melo971af182005-12-13 23:14:47 -080055int inet_csk_bind_conflict(const struct sock *sk,
56 const struct inet_bind_bucket *tb)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070057{
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070058 struct sock *sk2;
59 struct hlist_node *node;
60 int reuse = sk->sk_reuse;
61
Pavel Emelyanov7477fd2e2008-04-14 02:42:27 -070062 /*
63 * Unlike other sk lookup places we do not check
64 * for sk_net here, since _all_ the socks listed
65 * in tb->owners list belong to the same net - the
66 * one this bucket belongs to.
67 */
68
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070069 sk_for_each_bound(sk2, node, &tb->owners) {
70 if (sk != sk2 &&
71 !inet_v6_ipv6only(sk2) &&
72 (!sk->sk_bound_dev_if ||
73 !sk2->sk_bound_dev_if ||
74 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
75 if (!reuse || !sk2->sk_reuse ||
David S. Miller3e8c8062011-04-13 12:01:14 -070076 sk2->sk_state == TCP_LISTEN) {
Eric Dumazet68835ab2010-11-30 19:04:07 +000077 const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
78 if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) ||
79 sk2_rcv_saddr == sk_rcv_saddr(sk))
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070080 break;
David S. Miller8d238b22010-04-28 11:25:59 -070081 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070082 }
83 }
84 return node != NULL;
85}
Arnaldo Carvalho de Melo971af182005-12-13 23:14:47 -080086EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
87
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070088/* Obtain a reference to a local port for the given sock,
89 * if snum is zero it means select any available local port.
90 */
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -080091int inet_csk_get_port(struct sock *sk, unsigned short snum)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070092{
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -070093 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070094 struct inet_bind_hashbucket *head;
95 struct hlist_node *node;
96 struct inet_bind_bucket *tb;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -080097 int ret, attempts = 5;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +090098 struct net *net = sock_net(sk);
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -080099 int smallest_size = -1, smallest_rover;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700100
101 local_bh_disable();
102 if (!snum) {
Stephen Hemminger227b60f2007-10-10 17:30:46 -0700103 int remaining, rover, low, high;
104
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800105again:
Stephen Hemminger227b60f2007-10-10 17:30:46 -0700106 inet_get_local_port_range(&low, &high);
Anton Arapova25de532007-10-18 22:00:17 -0700107 remaining = (high - low) + 1;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800108 smallest_rover = rover = net_random() % remaining + low;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700109
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800110 smallest_size = -1;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700111 do {
Amerigo Wange3826f12010-05-05 00:27:06 +0000112 if (inet_is_reserved_local_port(rover))
113 goto next_nolock;
Pavel Emelyanov7f635ab2008-06-16 17:12:49 -0700114 head = &hashinfo->bhash[inet_bhashfn(net, rover,
115 hashinfo->bhash_size)];
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700116 spin_lock(&head->lock);
117 inet_bind_bucket_for_each(tb, node, &head->chain)
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800118 if (net_eq(ib_net(tb), net) && tb->port == rover) {
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800119 if (tb->fastreuse > 0 &&
120 sk->sk_reuse &&
121 sk->sk_state != TCP_LISTEN &&
122 (tb->num_owners < smallest_size || smallest_size == -1)) {
123 smallest_size = tb->num_owners;
124 smallest_rover = rover;
David S. Miller3e8c8062011-04-13 12:01:14 -0700125 if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
David S. Miller8d238b22010-04-28 11:25:59 -0700126 spin_unlock(&head->lock);
127 snum = smallest_rover;
128 goto have_snum;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800129 }
130 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700131 goto next;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800132 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700133 break;
134 next:
135 spin_unlock(&head->lock);
Amerigo Wange3826f12010-05-05 00:27:06 +0000136 next_nolock:
Stephen Hemminger6df71632005-11-03 16:33:23 -0800137 if (++rover > high)
138 rover = low;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700139 } while (--remaining > 0);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700140
141 /* Exhausted local port range during search? It is not
142 * possible for us to be holding one of the bind hash
143 * locks if this test triggers, because if 'remaining'
144 * drops to zero, we broke out of the do/while loop at
145 * the top level, not from the 'break;' statement.
146 */
147 ret = 1;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800148 if (remaining <= 0) {
149 if (smallest_size != -1) {
150 snum = smallest_rover;
151 goto have_snum;
152 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700153 goto fail;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800154 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700155 /* OK, here is the one we will use. HEAD is
156 * non-NULL and we hold it's mutex.
157 */
158 snum = rover;
159 } else {
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800160have_snum:
Pavel Emelyanov7f635ab2008-06-16 17:12:49 -0700161 head = &hashinfo->bhash[inet_bhashfn(net, snum,
162 hashinfo->bhash_size)];
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700163 spin_lock(&head->lock);
164 inet_bind_bucket_for_each(tb, node, &head->chain)
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800165 if (net_eq(ib_net(tb), net) && tb->port == snum)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700166 goto tb_found;
167 }
168 tb = NULL;
169 goto tb_not_found;
170tb_found:
171 if (!hlist_empty(&tb->owners)) {
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700172 if (tb->fastreuse > 0 &&
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800173 sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
174 smallest_size == -1) {
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700175 goto success;
176 } else {
177 ret = 1;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800178 if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
Stephen Hemminger5add3002009-02-01 01:40:17 -0800179 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
180 smallest_size != -1 && --attempts >= 0) {
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800181 spin_unlock(&head->lock);
182 goto again;
183 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700184 goto fail_unlock;
Evgeniy Polyakova9d8f912009-01-19 16:46:02 -0800185 }
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700186 }
187 }
188tb_not_found:
189 ret = 1;
Pavel Emelyanov941b1d22008-01-31 05:05:50 -0800190 if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
191 net, head, snum)) == NULL)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700192 goto fail_unlock;
193 if (hlist_empty(&tb->owners)) {
194 if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
195 tb->fastreuse = 1;
196 else
197 tb->fastreuse = 0;
198 } else if (tb->fastreuse &&
199 (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
200 tb->fastreuse = 0;
201success:
202 if (!inet_csk(sk)->icsk_bind_hash)
203 inet_bind_hash(sk, tb, snum);
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700204 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900205 ret = 0;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700206
207fail_unlock:
208 spin_unlock(&head->lock);
209fail:
210 local_bh_enable();
211 return ret;
212}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700213EXPORT_SYMBOL_GPL(inet_csk_get_port);
214
215/*
216 * Wait for an incoming connection, avoid race conditions. This must be called
217 * with the socket locked.
218 */
219static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
220{
221 struct inet_connection_sock *icsk = inet_csk(sk);
222 DEFINE_WAIT(wait);
223 int err;
224
225 /*
226 * True wake-one mechanism for incoming connections: only
227 * one process gets woken up, not the 'whole herd'.
228 * Since we do not 'race & poll' for established sockets
229 * anymore, the common case will execute the loop only once.
230 *
231 * Subtle issue: "add_wait_queue_exclusive()" will be added
232 * after any current non-exclusive waiters, and we know that
233 * it will always _stay_ after any new non-exclusive waiters
234 * because all non-exclusive waiters are added at the
235 * beginning of the wait-queue. As such, it's ok to "drop"
236 * our exclusiveness temporarily when we get woken up without
237 * having to remove and re-insert us on the wait queue.
238 */
239 for (;;) {
Eric Dumazetaa395142010-04-20 13:03:51 +0000240 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700241 TASK_INTERRUPTIBLE);
242 release_sock(sk);
243 if (reqsk_queue_empty(&icsk->icsk_accept_queue))
244 timeo = schedule_timeout(timeo);
245 lock_sock(sk);
246 err = 0;
247 if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
248 break;
249 err = -EINVAL;
250 if (sk->sk_state != TCP_LISTEN)
251 break;
252 err = sock_intr_errno(timeo);
253 if (signal_pending(current))
254 break;
255 err = -EAGAIN;
256 if (!timeo)
257 break;
258 }
Eric Dumazetaa395142010-04-20 13:03:51 +0000259 finish_wait(sk_sleep(sk), &wait);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700260 return err;
261}
262
263/*
264 * This will accept the next outstanding connection.
265 */
266struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
267{
268 struct inet_connection_sock *icsk = inet_csk(sk);
269 struct sock *newsk;
270 int error;
271
272 lock_sock(sk);
273
274 /* We need to make sure that this socket is listening,
275 * and that it has something pending.
276 */
277 error = -EINVAL;
278 if (sk->sk_state != TCP_LISTEN)
279 goto out_err;
280
281 /* Find already established connection */
282 if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
283 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
284
285 /* If this is a non blocking socket don't sleep */
286 error = -EAGAIN;
287 if (!timeo)
288 goto out_err;
289
290 error = inet_csk_wait_for_connect(sk, timeo);
291 if (error)
292 goto out_err;
293 }
294
295 newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700296 WARN_ON(newsk->sk_state == TCP_SYN_RECV);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700297out:
298 release_sock(sk);
299 return newsk;
300out_err:
301 newsk = NULL;
302 *err = error;
303 goto out;
304}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700305EXPORT_SYMBOL(inet_csk_accept);
306
307/*
308 * Using different timers for retransmit, delayed acks and probes
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900309 * We may wish use just one timer maintaining a list of expire jiffies
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700310 * to optimize.
311 */
312void inet_csk_init_xmit_timers(struct sock *sk,
313 void (*retransmit_handler)(unsigned long),
314 void (*delack_handler)(unsigned long),
315 void (*keepalive_handler)(unsigned long))
316{
317 struct inet_connection_sock *icsk = inet_csk(sk);
318
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800319 setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
320 (unsigned long)sk);
321 setup_timer(&icsk->icsk_delack_timer, delack_handler,
322 (unsigned long)sk);
323 setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700324 icsk->icsk_pending = icsk->icsk_ack.pending = 0;
325}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700326EXPORT_SYMBOL(inet_csk_init_xmit_timers);
327
328void inet_csk_clear_xmit_timers(struct sock *sk)
329{
330 struct inet_connection_sock *icsk = inet_csk(sk);
331
332 icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
333
334 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
335 sk_stop_timer(sk, &icsk->icsk_delack_timer);
336 sk_stop_timer(sk, &sk->sk_timer);
337}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700338EXPORT_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}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700344EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
345
346void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
347{
348 sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
349}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700350EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
351
Jianjun Kongd93191002008-11-03 00:23:42 -0800352struct dst_entry *inet_csk_route_req(struct sock *sk,
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700353 const struct request_sock *req)
354{
355 struct rtable *rt;
356 const struct inet_request_sock *ireq = inet_rsk(req);
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000357 struct ip_options_rcu *opt = inet_rsk(req)->opt;
Pavel Emelyanov84a3aa02008-07-16 20:19:08 -0700358 struct net *net = sock_net(sk);
David S. Millere79d9bc2011-03-31 04:53:20 -0700359 struct flowi4 fl4;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700360
David S. Millere79d9bc2011-03-31 04:53:20 -0700361 flowi4_init_output(&fl4, sk->sk_bound_dev_if, sk->sk_mark,
362 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
363 sk->sk_protocol, inet_sk_flowi_flags(sk),
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000364 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
David S. Millere79d9bc2011-03-31 04:53:20 -0700365 ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport);
David S. Miller9d6ec932011-03-12 01:12:47 -0500366 security_req_classify_flow(req, flowi4_to_flowi(&fl4));
367 rt = ip_route_output_flow(net, &fl4, sk);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800368 if (IS_ERR(rt))
Ilpo Järvinen857a6e02008-12-14 23:13:08 -0800369 goto no_route;
David S. Miller072d8c92011-04-28 23:50:09 -0700370 if (opt && opt->opt.is_strictroute && fl4.daddr != rt->rt_gateway)
Ilpo Järvinen857a6e02008-12-14 23:13:08 -0800371 goto route_err;
Changli Gaod8d1f302010-06-10 23:31:35 -0700372 return &rt->dst;
Ilpo Järvinen857a6e02008-12-14 23:13:08 -0800373
374route_err:
375 ip_rt_put(rt);
376no_route:
377 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
378 return NULL;
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700379}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700380EXPORT_SYMBOL_GPL(inet_csk_route_req);
381
David S. Miller77357a92011-05-08 14:34:22 -0700382struct dst_entry *inet_csk_route_child_sock(struct sock *sk,
383 struct sock *newsk,
384 const struct request_sock *req)
385{
386 const struct inet_request_sock *ireq = inet_rsk(req);
387 struct inet_sock *newinet = inet_sk(newsk);
388 struct ip_options_rcu *opt = ireq->opt;
389 struct net *net = sock_net(sk);
390 struct flowi4 *fl4;
391 struct rtable *rt;
392
393 fl4 = &newinet->cork.fl.u.ip4;
394 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
395 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
396 sk->sk_protocol, inet_sk_flowi_flags(sk),
397 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
398 ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport);
399 security_req_classify_flow(req, flowi4_to_flowi(fl4));
400 rt = ip_route_output_flow(net, fl4, sk);
401 if (IS_ERR(rt))
402 goto no_route;
403 if (opt && opt->opt.is_strictroute && fl4->daddr != rt->rt_gateway)
404 goto route_err;
405 return &rt->dst;
406
407route_err:
408 ip_rt_put(rt);
409no_route:
410 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
411 return NULL;
412}
413EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
414
Al Viro6b729772006-09-27 18:36:59 -0700415static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
Eric Dumazet72a3eff2006-11-16 02:30:37 -0800416 const u32 rnd, const u32 synq_hsize)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700417{
Al Viro6b729772006-09-27 18:36:59 -0700418 return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700419}
420
421#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
422#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
423#else
424#define AF_INET_FAMILY(fam) 1
425#endif
426
427struct request_sock *inet_csk_search_req(const struct sock *sk,
428 struct request_sock ***prevp,
Al Viro6b729772006-09-27 18:36:59 -0700429 const __be16 rport, const __be32 raddr,
Al Viro7f25afb2006-09-27 18:27:47 -0700430 const __be32 laddr)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700431{
432 const struct inet_connection_sock *icsk = inet_csk(sk);
433 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
434 struct request_sock *req, **prev;
435
436 for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
437 lopt->nr_table_entries)];
438 (req = *prev) != NULL;
439 prev = &req->dl_next) {
440 const struct inet_request_sock *ireq = inet_rsk(req);
441
442 if (ireq->rmt_port == rport &&
443 ireq->rmt_addr == raddr &&
444 ireq->loc_addr == laddr &&
445 AF_INET_FAMILY(req->rsk_ops->family)) {
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700446 WARN_ON(req->sk);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700447 *prevp = prev;
448 break;
449 }
450 }
451
452 return req;
453}
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700454EXPORT_SYMBOL_GPL(inet_csk_search_req);
455
456void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
Arnaldo Carvalho de Meloc2977c22005-12-13 23:15:12 -0800457 unsigned long timeout)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700458{
459 struct inet_connection_sock *icsk = inet_csk(sk);
460 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
461 const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
462 lopt->hash_rnd, lopt->nr_table_entries);
463
464 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
465 inet_csk_reqsk_queue_added(sk, timeout);
466}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000467EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700468
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700469/* Only thing we need from tcp.h */
470extern int sysctl_tcp_synack_retries;
471
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700472
Julian Anastasov0c3d79b2009-10-19 10:03:58 +0000473/* Decide when to expire the request and when to resend SYN-ACK */
474static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
475 const int max_retries,
476 const u8 rskq_defer_accept,
477 int *expire, int *resend)
478{
479 if (!rskq_defer_accept) {
480 *expire = req->retrans >= thresh;
481 *resend = 1;
482 return;
483 }
484 *expire = req->retrans >= thresh &&
485 (!inet_rsk(req)->acked || req->retrans >= max_retries);
486 /*
487 * Do not resend while waiting for data after ACK,
488 * start to resend on end of deferring period to give
489 * last chance for data or ACK to create established socket.
490 */
491 *resend = !inet_rsk(req)->acked ||
492 req->retrans >= rskq_defer_accept - 1;
493}
494
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700495void inet_csk_reqsk_queue_prune(struct sock *parent,
496 const unsigned long interval,
497 const unsigned long timeout,
498 const unsigned long max_rto)
499{
500 struct inet_connection_sock *icsk = inet_csk(parent);
501 struct request_sock_queue *queue = &icsk->icsk_accept_queue;
502 struct listen_sock *lopt = queue->listen_opt;
David S. Millerec0a1962008-06-12 16:31:35 -0700503 int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
504 int thresh = max_retries;
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700505 unsigned long now = jiffies;
506 struct request_sock **reqp, *req;
507 int i, budget;
508
509 if (lopt == NULL || lopt->qlen == 0)
510 return;
511
512 /* Normally all the openreqs are young and become mature
513 * (i.e. converted to established socket) for first timeout.
514 * If synack was not acknowledged for 3 seconds, it means
515 * one of the following things: synack was lost, ack was lost,
516 * rtt is high or nobody planned to ack (i.e. synflood).
517 * When server is a bit loaded, queue is populated with old
518 * open requests, reducing effective size of queue.
519 * When server is well loaded, queue size reduces to zero
520 * after several minutes of work. It is not synflood,
521 * it is normal operation. The solution is pruning
522 * too old entries overriding normal timeout, when
523 * situation becomes dangerous.
524 *
525 * Essentially, we reserve half of room for young
526 * embrions; and abort old ones without pity, if old
527 * ones are about to clog our table.
528 */
529 if (lopt->qlen>>(lopt->max_qlen_log-1)) {
530 int young = (lopt->qlen_young<<1);
531
532 while (thresh > 2) {
533 if (lopt->qlen < young)
534 break;
535 thresh--;
536 young <<= 1;
537 }
538 }
539
David S. Millerec0a1962008-06-12 16:31:35 -0700540 if (queue->rskq_defer_accept)
541 max_retries = queue->rskq_defer_accept;
542
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700543 budget = 2 * (lopt->nr_table_entries / (timeout / interval));
544 i = lopt->clock_hand;
545
546 do {
547 reqp=&lopt->syn_table[i];
548 while ((req = *reqp) != NULL) {
549 if (time_after_eq(now, req->expires)) {
Julian Anastasov0c3d79b2009-10-19 10:03:58 +0000550 int expire = 0, resend = 0;
551
552 syn_ack_recalc(req, thresh, max_retries,
553 queue->rskq_defer_accept,
554 &expire, &resend);
Octavian Purdila72659ec2010-01-17 19:09:39 -0800555 if (req->rsk_ops->syn_ack_timeout)
556 req->rsk_ops->syn_ack_timeout(parent, req);
Julian Anastasov0c3d79b2009-10-19 10:03:58 +0000557 if (!expire &&
558 (!resend ||
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000559 !req->rsk_ops->rtx_syn_ack(parent, req, NULL) ||
Julian Anastasov0c3d79b2009-10-19 10:03:58 +0000560 inet_rsk(req)->acked)) {
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700561 unsigned long timeo;
562
563 if (req->retrans++ == 0)
564 lopt->qlen_young--;
565 timeo = min((timeout << req->retrans), max_rto);
566 req->expires = now + timeo;
567 reqp = &req->dl_next;
568 continue;
569 }
570
571 /* Drop this request */
572 inet_csk_reqsk_queue_unlink(parent, req, reqp);
573 reqsk_queue_removed(queue, req);
574 reqsk_free(req);
575 continue;
576 }
577 reqp = &req->dl_next;
578 }
579
580 i = (i + 1) & (lopt->nr_table_entries - 1);
581
582 } while (--budget > 0);
583
584 lopt->clock_hand = i;
585
586 if (lopt->qlen)
587 inet_csk_reset_keepalive_timer(parent, interval);
588}
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700589EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
590
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700591struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
Al Virodd0fc662005-10-07 07:46:04 +0100592 const gfp_t priority)
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700593{
594 struct sock *newsk = sk_clone(sk, priority);
595
596 if (newsk != NULL) {
597 struct inet_connection_sock *newicsk = inet_csk(newsk);
598
599 newsk->sk_state = TCP_SYN_RECV;
600 newicsk->icsk_bind_hash = NULL;
601
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000602 inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port;
603 inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port);
604 inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port;
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700605 newsk->sk_write_space = sk_stream_write_space;
606
607 newicsk->icsk_retransmits = 0;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300608 newicsk->icsk_backoff = 0;
609 newicsk->icsk_probes_out = 0;
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700610
611 /* Deinitialize accept_queue to trap illegal accesses. */
612 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
Venkat Yekkirala4237c752006-07-24 23:32:50 -0700613
614 security_inet_csk_clone(newsk, req);
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700615 }
616 return newsk;
617}
Arnaldo Carvalho de Melo9f1d2602005-08-09 20:11:24 -0700618EXPORT_SYMBOL_GPL(inet_csk_clone);
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700619
620/*
621 * At this point, there should be no process reference to this
622 * socket, and thus no user references at all. Therefore we
623 * can assume the socket waitqueue is inactive and nobody will
624 * try to jump onto it.
625 */
626void inet_csk_destroy_sock(struct sock *sk)
627{
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700628 WARN_ON(sk->sk_state != TCP_CLOSE);
629 WARN_ON(!sock_flag(sk, SOCK_DEAD));
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700630
631 /* It cannot be in hash table! */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700632 WARN_ON(!sk_unhashed(sk));
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700633
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000634 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
635 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700636
637 sk->sk_prot->destroy(sk);
638
639 sk_stream_kill_queues(sk);
640
641 xfrm_sk_free_policy(sk);
642
643 sk_refcnt_debug_release(sk);
644
Eric Dumazetdd24c002008-11-25 21:17:14 -0800645 percpu_counter_dec(sk->sk_prot->orphan_count);
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700646 sock_put(sk);
647}
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700648EXPORT_SYMBOL(inet_csk_destroy_sock);
649
650int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
651{
652 struct inet_sock *inet = inet_sk(sk);
653 struct inet_connection_sock *icsk = inet_csk(sk);
654 int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
655
656 if (rc != 0)
657 return rc;
658
659 sk->sk_max_ack_backlog = 0;
660 sk->sk_ack_backlog = 0;
661 inet_csk_delack_init(sk);
662
663 /* There is race window here: we announce ourselves listening,
664 * but this transition is still not validated by get_port().
665 * It is OK, because this socket enters to hash table only
666 * after validation is complete.
667 */
668 sk->sk_state = TCP_LISTEN;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000669 if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
670 inet->inet_sport = htons(inet->inet_num);
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700671
672 sk_dst_reset(sk);
673 sk->sk_prot->hash(sk);
674
675 return 0;
676 }
677
678 sk->sk_state = TCP_CLOSE;
679 __reqsk_queue_destroy(&icsk->icsk_accept_queue);
680 return -EADDRINUSE;
681}
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700682EXPORT_SYMBOL_GPL(inet_csk_listen_start);
683
684/*
685 * This routine closes sockets which have been at least partially
686 * opened, but not yet accepted.
687 */
688void inet_csk_listen_stop(struct sock *sk)
689{
690 struct inet_connection_sock *icsk = inet_csk(sk);
691 struct request_sock *acc_req;
692 struct request_sock *req;
693
694 inet_csk_delete_keepalive_timer(sk);
695
696 /* make all the listen_opt local to us */
697 acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
698
699 /* Following specs, it would be better either to send FIN
700 * (and enter FIN-WAIT-1, it is normal close)
701 * or to send active reset (abort).
702 * Certainly, it is pretty dangerous while synflood, but it is
703 * bad justification for our negligence 8)
704 * To be honest, we are not able to make either
705 * of the variants now. --ANK
706 */
707 reqsk_queue_destroy(&icsk->icsk_accept_queue);
708
709 while ((req = acc_req) != NULL) {
710 struct sock *child = req->sk;
711
712 acc_req = req->dl_next;
713
714 local_bh_disable();
715 bh_lock_sock(child);
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700716 WARN_ON(sock_owned_by_user(child));
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700717 sock_hold(child);
718
719 sk->sk_prot->disconnect(child, O_NONBLOCK);
720
721 sock_orphan(child);
722
Herbert Xueb4dea52008-12-29 23:04:08 -0800723 percpu_counter_inc(sk->sk_prot->orphan_count);
724
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700725 inet_csk_destroy_sock(child);
726
727 bh_unlock_sock(child);
728 local_bh_enable();
729 sock_put(child);
730
731 sk_acceptq_removed(sk);
732 __reqsk_free(req);
733 }
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700734 WARN_ON(sk->sk_ack_backlog);
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700735}
Arnaldo Carvalho de Meloa019d6f2005-08-09 20:15:09 -0700736EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
Arnaldo Carvalho de Meloaf05dc92005-12-13 23:16:04 -0800737
738void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
739{
740 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
741 const struct inet_sock *inet = inet_sk(sk);
742
743 sin->sin_family = AF_INET;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000744 sin->sin_addr.s_addr = inet->inet_daddr;
745 sin->sin_port = inet->inet_dport;
Arnaldo Carvalho de Meloaf05dc92005-12-13 23:16:04 -0800746}
Arnaldo Carvalho de Meloaf05dc92005-12-13 23:16:04 -0800747EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
Arnaldo Carvalho de Meloc4d93902006-03-20 22:01:03 -0800748
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -0800749#ifdef CONFIG_COMPAT
750int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
751 char __user *optval, int __user *optlen)
752{
David S. Millerdbeff122006-03-20 22:52:32 -0800753 const struct inet_connection_sock *icsk = inet_csk(sk);
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -0800754
755 if (icsk->icsk_af_ops->compat_getsockopt != NULL)
756 return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
757 optval, optlen);
758 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
759 optval, optlen);
760}
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -0800761EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
762
763int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
David S. Millerb7058842009-09-30 16:12:20 -0700764 char __user *optval, unsigned int optlen)
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -0800765{
David S. Millerdbeff122006-03-20 22:52:32 -0800766 const struct inet_connection_sock *icsk = inet_csk(sk);
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -0800767
768 if (icsk->icsk_af_ops->compat_setsockopt != NULL)
769 return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
770 optval, optlen);
771 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
772 optval, optlen);
773}
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -0800774EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
775#endif