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1/*
2 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
3 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation (or any later at your option).
8 */
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/rculist.h>
13#include <linux/rculist_nulls.h>
14#include <linux/types.h>
15#include <linux/timer.h>
16#include <linux/security.h>
17#include <linux/skbuff.h>
18#include <linux/errno.h>
19#include <linux/netlink.h>
20#include <linux/spinlock.h>
21#include <linux/interrupt.h>
22#include <linux/slab.h>
23
24#include <linux/netfilter.h>
25#include <net/netlink.h>
26#include <net/sock.h>
27#include <net/netfilter/nf_conntrack.h>
28#include <net/netfilter/nf_conntrack_core.h>
29#include <net/netfilter/nf_conntrack_l3proto.h>
30#include <net/netfilter/nf_conntrack_l4proto.h>
31#include <net/netfilter/nf_conntrack_tuple.h>
32#include <net/netfilter/nf_conntrack_timeout.h>
33
34#include <linux/netfilter/nfnetlink.h>
35#include <linux/netfilter/nfnetlink_cttimeout.h>
36
37MODULE_LICENSE("GPL");
38MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
39MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
40
41static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
42 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
43 .len = CTNL_TIMEOUT_NAME_MAX - 1},
44 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
45 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
46 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
47};
48
49static int
50ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
51 struct net *net, const struct nlattr *attr)
52{
53 int ret = 0;
54
55 if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
56 struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
57
58 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
59 attr, l4proto->ctnl_timeout.nla_policy);
60 if (ret < 0)
61 return ret;
62
63 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
64 }
65 return ret;
66}
67
68static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
69 struct sk_buff *skb,
70 const struct nlmsghdr *nlh,
71 const struct nlattr * const cda[])
72{
73 __u16 l3num;
74 __u8 l4num;
75 struct nf_conntrack_l4proto *l4proto;
76 struct ctnl_timeout *timeout, *matching = NULL;
77 char *name;
78 int ret;
79
80 if (!cda[CTA_TIMEOUT_NAME] ||
81 !cda[CTA_TIMEOUT_L3PROTO] ||
82 !cda[CTA_TIMEOUT_L4PROTO] ||
83 !cda[CTA_TIMEOUT_DATA])
84 return -EINVAL;
85
86 name = nla_data(cda[CTA_TIMEOUT_NAME]);
87 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
88 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
89
90 list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
91 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
92 continue;
93
94 if (nlh->nlmsg_flags & NLM_F_EXCL)
95 return -EEXIST;
96
97 matching = timeout;
98 break;
99 }
100
101 if (matching) {
102 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
103 /* You cannot replace one timeout policy by another of
104 * different kind, sorry.
105 */
106 if (matching->l3num != l3num ||
107 matching->l4proto->l4proto != l4num)
108 return -EINVAL;
109
110 return ctnl_timeout_parse_policy(&matching->data,
111 matching->l4proto, net,
112 cda[CTA_TIMEOUT_DATA]);
113 }
114
115 return -EBUSY;
116 }
117
118 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
119
120 /* This protocol is not supportted, skip. */
121 if (l4proto->l4proto != l4num) {
122 ret = -EOPNOTSUPP;
123 goto err_proto_put;
124 }
125
126 timeout = kzalloc(sizeof(struct ctnl_timeout) +
127 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
128 if (timeout == NULL) {
129 ret = -ENOMEM;
130 goto err_proto_put;
131 }
132
133 ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
134 cda[CTA_TIMEOUT_DATA]);
135 if (ret < 0)
136 goto err;
137
138 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
139 timeout->l3num = l3num;
140 timeout->l4proto = l4proto;
141 atomic_set(&timeout->refcnt, 1);
142 list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
143
144 return 0;
145err:
146 kfree(timeout);
147err_proto_put:
148 nf_ct_l4proto_put(l4proto);
149 return ret;
150}
151
152static int
153ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
154 int event, struct ctnl_timeout *timeout)
155{
156 struct nlmsghdr *nlh;
157 struct nfgenmsg *nfmsg;
158 unsigned int flags = portid ? NLM_F_MULTI : 0;
159 struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
160
161 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
162 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
163 if (nlh == NULL)
164 goto nlmsg_failure;
165
166 nfmsg = nlmsg_data(nlh);
167 nfmsg->nfgen_family = AF_UNSPEC;
168 nfmsg->version = NFNETLINK_V0;
169 nfmsg->res_id = 0;
170
171 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
172 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) ||
173 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) ||
174 nla_put_be32(skb, CTA_TIMEOUT_USE,
175 htonl(atomic_read(&timeout->refcnt))))
176 goto nla_put_failure;
177
178 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
179 struct nlattr *nest_parms;
180 int ret;
181
182 nest_parms = nla_nest_start(skb,
183 CTA_TIMEOUT_DATA | NLA_F_NESTED);
184 if (!nest_parms)
185 goto nla_put_failure;
186
187 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
188 if (ret < 0)
189 goto nla_put_failure;
190
191 nla_nest_end(skb, nest_parms);
192 }
193
194 nlmsg_end(skb, nlh);
195 return skb->len;
196
197nlmsg_failure:
198nla_put_failure:
199 nlmsg_cancel(skb, nlh);
200 return -1;
201}
202
203static int
204ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
205{
206 struct net *net = sock_net(skb->sk);
207 struct ctnl_timeout *cur, *last;
208
209 if (cb->args[2])
210 return 0;
211
212 last = (struct ctnl_timeout *)cb->args[1];
213 if (cb->args[1])
214 cb->args[1] = 0;
215
216 rcu_read_lock();
217 list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
218 if (last) {
219 if (cur != last)
220 continue;
221
222 last = NULL;
223 }
224 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
225 cb->nlh->nlmsg_seq,
226 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
227 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
228 cb->args[1] = (unsigned long)cur;
229 break;
230 }
231 }
232 if (!cb->args[1])
233 cb->args[2] = 1;
234 rcu_read_unlock();
235 return skb->len;
236}
237
238static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
239 struct sk_buff *skb,
240 const struct nlmsghdr *nlh,
241 const struct nlattr * const cda[])
242{
243 int ret = -ENOENT;
244 char *name;
245 struct ctnl_timeout *cur;
246
247 if (nlh->nlmsg_flags & NLM_F_DUMP) {
248 struct netlink_dump_control c = {
249 .dump = ctnl_timeout_dump,
250 };
251 return netlink_dump_start(ctnl, skb, nlh, &c);
252 }
253
254 if (!cda[CTA_TIMEOUT_NAME])
255 return -EINVAL;
256 name = nla_data(cda[CTA_TIMEOUT_NAME]);
257
258 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
259 struct sk_buff *skb2;
260
261 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
262 continue;
263
264 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
265 if (skb2 == NULL) {
266 ret = -ENOMEM;
267 break;
268 }
269
270 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
271 nlh->nlmsg_seq,
272 NFNL_MSG_TYPE(nlh->nlmsg_type),
273 IPCTNL_MSG_TIMEOUT_NEW, cur);
274 if (ret <= 0) {
275 kfree_skb(skb2);
276 break;
277 }
278 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
279 MSG_DONTWAIT);
280 if (ret > 0)
281 ret = 0;
282
283 /* this avoids a loop in nfnetlink. */
284 return ret == -EAGAIN ? -ENOBUFS : ret;
285 }
286 return ret;
287}
288
289static void untimeout(struct nf_conntrack_tuple_hash *i,
290 struct ctnl_timeout *timeout)
291{
292 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
293 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
294
295 if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
296 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
297}
298
299static void ctnl_untimeout(struct net *net, struct ctnl_timeout *timeout)
300{
301 struct nf_conntrack_tuple_hash *h;
302 const struct hlist_nulls_node *nn;
303 unsigned int last_hsize;
304 spinlock_t *lock;
305 int i, cpu;
306
307 for_each_possible_cpu(cpu) {
308 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
309
310 spin_lock_bh(&pcpu->lock);
311 hlist_nulls_for_each_entry(h, nn, &pcpu->unconfirmed, hnnode)
312 untimeout(h, timeout);
313 spin_unlock_bh(&pcpu->lock);
314 }
315
316 local_bh_disable();
317restart:
318 last_hsize = nf_conntrack_htable_size;
319 for (i = 0; i < last_hsize; i++) {
320 lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
321 nf_conntrack_lock(lock);
322 if (last_hsize != nf_conntrack_htable_size) {
323 spin_unlock(lock);
324 goto restart;
325 }
326
327 hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
328 untimeout(h, timeout);
329 spin_unlock(lock);
330 }
331 local_bh_enable();
332}
333
334/* try to delete object, fail if it is still in use. */
335static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
336{
337 int ret = 0;
338
339 /* We want to avoid races with ctnl_timeout_put. So only when the
340 * current refcnt is 1, we decrease it to 0.
341 */
342 if (atomic_cmpxchg(&timeout->refcnt, 1, 0) == 1) {
343 /* We are protected by nfnl mutex. */
344 list_del_rcu(&timeout->head);
345 nf_ct_l4proto_put(timeout->l4proto);
346 ctnl_untimeout(net, timeout);
347 kfree_rcu(timeout, rcu_head);
348 } else {
349 ret = -EBUSY;
350 }
351 return ret;
352}
353
354static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
355 struct sk_buff *skb,
356 const struct nlmsghdr *nlh,
357 const struct nlattr * const cda[])
358{
359 struct ctnl_timeout *cur, *tmp;
360 int ret = -ENOENT;
361 char *name;
362
363 if (!cda[CTA_TIMEOUT_NAME]) {
364 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
365 head)
366 ctnl_timeout_try_del(net, cur);
367
368 return 0;
369 }
370 name = nla_data(cda[CTA_TIMEOUT_NAME]);
371
372 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
373 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
374 continue;
375
376 ret = ctnl_timeout_try_del(net, cur);
377 if (ret < 0)
378 return ret;
379
380 break;
381 }
382 return ret;
383}
384
385static int cttimeout_default_set(struct net *net, struct sock *ctnl,
386 struct sk_buff *skb,
387 const struct nlmsghdr *nlh,
388 const struct nlattr * const cda[])
389{
390 __u16 l3num;
391 __u8 l4num;
392 struct nf_conntrack_l4proto *l4proto;
393 unsigned int *timeouts;
394 int ret;
395
396 if (!cda[CTA_TIMEOUT_L3PROTO] ||
397 !cda[CTA_TIMEOUT_L4PROTO] ||
398 !cda[CTA_TIMEOUT_DATA])
399 return -EINVAL;
400
401 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
402 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
403 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
404
405 /* This protocol is not supported, skip. */
406 if (l4proto->l4proto != l4num) {
407 ret = -EOPNOTSUPP;
408 goto err;
409 }
410
411 timeouts = l4proto->get_timeouts(net);
412
413 ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
414 cda[CTA_TIMEOUT_DATA]);
415 if (ret < 0)
416 goto err;
417
418 nf_ct_l4proto_put(l4proto);
419 return 0;
420err:
421 nf_ct_l4proto_put(l4proto);
422 return ret;
423}
424
425static int
426cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
427 u32 seq, u32 type, int event,
428 struct nf_conntrack_l4proto *l4proto)
429{
430 struct nlmsghdr *nlh;
431 struct nfgenmsg *nfmsg;
432 unsigned int flags = portid ? NLM_F_MULTI : 0;
433
434 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
435 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
436 if (nlh == NULL)
437 goto nlmsg_failure;
438
439 nfmsg = nlmsg_data(nlh);
440 nfmsg->nfgen_family = AF_UNSPEC;
441 nfmsg->version = NFNETLINK_V0;
442 nfmsg->res_id = 0;
443
444 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
445 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
446 goto nla_put_failure;
447
448 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
449 struct nlattr *nest_parms;
450 unsigned int *timeouts = l4proto->get_timeouts(net);
451 int ret;
452
453 nest_parms = nla_nest_start(skb,
454 CTA_TIMEOUT_DATA | NLA_F_NESTED);
455 if (!nest_parms)
456 goto nla_put_failure;
457
458 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
459 if (ret < 0)
460 goto nla_put_failure;
461
462 nla_nest_end(skb, nest_parms);
463 }
464
465 nlmsg_end(skb, nlh);
466 return skb->len;
467
468nlmsg_failure:
469nla_put_failure:
470 nlmsg_cancel(skb, nlh);
471 return -1;
472}
473
474static int cttimeout_default_get(struct net *net, struct sock *ctnl,
475 struct sk_buff *skb,
476 const struct nlmsghdr *nlh,
477 const struct nlattr * const cda[])
478{
479 __u16 l3num;
480 __u8 l4num;
481 struct nf_conntrack_l4proto *l4proto;
482 struct sk_buff *skb2;
483 int ret, err;
484
485 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
486 return -EINVAL;
487
488 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
489 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
490 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
491
492 /* This protocol is not supported, skip. */
493 if (l4proto->l4proto != l4num) {
494 err = -EOPNOTSUPP;
495 goto err;
496 }
497
498 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
499 if (skb2 == NULL) {
500 err = -ENOMEM;
501 goto err;
502 }
503
504 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
505 nlh->nlmsg_seq,
506 NFNL_MSG_TYPE(nlh->nlmsg_type),
507 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
508 l4proto);
509 if (ret <= 0) {
510 kfree_skb(skb2);
511 err = -ENOMEM;
512 goto err;
513 }
514 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
515 if (ret > 0)
516 ret = 0;
517
518 /* this avoids a loop in nfnetlink. */
519 return ret == -EAGAIN ? -ENOBUFS : ret;
520err:
521 nf_ct_l4proto_put(l4proto);
522 return err;
523}
524
525#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
526static struct ctnl_timeout *
527ctnl_timeout_find_get(struct net *net, const char *name)
528{
529 struct ctnl_timeout *timeout, *matching = NULL;
530
531 rcu_read_lock();
532 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
533 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
534 continue;
535
536 if (!try_module_get(THIS_MODULE))
537 goto err;
538
539 if (!atomic_inc_not_zero(&timeout->refcnt)) {
540 module_put(THIS_MODULE);
541 goto err;
542 }
543 matching = timeout;
544 break;
545 }
546err:
547 rcu_read_unlock();
548 return matching;
549}
550
551static void ctnl_timeout_put(struct ctnl_timeout *timeout)
552{
553 if (atomic_dec_and_test(&timeout->refcnt))
554 kfree_rcu(timeout, rcu_head);
555
556 module_put(THIS_MODULE);
557}
558#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
559
560static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
561 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
562 .attr_count = CTA_TIMEOUT_MAX,
563 .policy = cttimeout_nla_policy },
564 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
565 .attr_count = CTA_TIMEOUT_MAX,
566 .policy = cttimeout_nla_policy },
567 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
568 .attr_count = CTA_TIMEOUT_MAX,
569 .policy = cttimeout_nla_policy },
570 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
571 .attr_count = CTA_TIMEOUT_MAX,
572 .policy = cttimeout_nla_policy },
573 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
574 .attr_count = CTA_TIMEOUT_MAX,
575 .policy = cttimeout_nla_policy },
576};
577
578static const struct nfnetlink_subsystem cttimeout_subsys = {
579 .name = "conntrack_timeout",
580 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
581 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
582 .cb = cttimeout_cb,
583};
584
585MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
586
587static int __net_init cttimeout_net_init(struct net *net)
588{
589 INIT_LIST_HEAD(&net->nfct_timeout_list);
590
591 return 0;
592}
593
594static void __net_exit cttimeout_net_exit(struct net *net)
595{
596 struct ctnl_timeout *cur, *tmp;
597
598 ctnl_untimeout(net, NULL);
599
600 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
601 list_del_rcu(&cur->head);
602 nf_ct_l4proto_put(cur->l4proto);
603
604 if (atomic_dec_and_test(&cur->refcnt))
605 kfree_rcu(cur, rcu_head);
606 }
607}
608
609static struct pernet_operations cttimeout_ops = {
610 .init = cttimeout_net_init,
611 .exit = cttimeout_net_exit,
612};
613
614static int __init cttimeout_init(void)
615{
616 int ret;
617
618 ret = register_pernet_subsys(&cttimeout_ops);
619 if (ret < 0)
620 return ret;
621
622 ret = nfnetlink_subsys_register(&cttimeout_subsys);
623 if (ret < 0) {
624 pr_err("cttimeout_init: cannot register cttimeout with "
625 "nfnetlink.\n");
626 goto err_out;
627 }
628#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
629 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
630 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
631#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
632 return 0;
633
634err_out:
635 unregister_pernet_subsys(&cttimeout_ops);
636 return ret;
637}
638
639static void __exit cttimeout_exit(void)
640{
641 pr_info("cttimeout: unregistering from nfnetlink.\n");
642
643 nfnetlink_subsys_unregister(&cttimeout_subsys);
644
645 unregister_pernet_subsys(&cttimeout_ops);
646#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
647 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
648 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
649#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
650 rcu_barrier();
651}
652
653module_init(cttimeout_init);
654module_exit(cttimeout_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
4 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
5 */
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/rculist.h>
10#include <linux/rculist_nulls.h>
11#include <linux/types.h>
12#include <linux/timer.h>
13#include <linux/security.h>
14#include <linux/skbuff.h>
15#include <linux/errno.h>
16#include <linux/netlink.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20
21#include <linux/netfilter.h>
22#include <net/netlink.h>
23#include <net/netns/generic.h>
24#include <net/sock.h>
25#include <net/netfilter/nf_conntrack.h>
26#include <net/netfilter/nf_conntrack_core.h>
27#include <net/netfilter/nf_conntrack_l4proto.h>
28#include <net/netfilter/nf_conntrack_tuple.h>
29#include <net/netfilter/nf_conntrack_timeout.h>
30
31#include <linux/netfilter/nfnetlink.h>
32#include <linux/netfilter/nfnetlink_cttimeout.h>
33
34static unsigned int nfct_timeout_id __read_mostly;
35
36struct ctnl_timeout {
37 struct list_head head;
38 struct list_head free_head;
39 struct rcu_head rcu_head;
40 refcount_t refcnt;
41 char name[CTNL_TIMEOUT_NAME_MAX];
42
43 /* must be at the end */
44 struct nf_ct_timeout timeout;
45};
46
47struct nfct_timeout_pernet {
48 struct list_head nfct_timeout_list;
49 struct list_head nfct_timeout_freelist;
50};
51
52MODULE_LICENSE("GPL");
53MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
54MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
55
56static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
57 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
58 .len = CTNL_TIMEOUT_NAME_MAX - 1},
59 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
60 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
61 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
62};
63
64static struct nfct_timeout_pernet *nfct_timeout_pernet(struct net *net)
65{
66 return net_generic(net, nfct_timeout_id);
67}
68
69static int
70ctnl_timeout_parse_policy(void *timeout,
71 const struct nf_conntrack_l4proto *l4proto,
72 struct net *net, const struct nlattr *attr)
73{
74 struct nlattr **tb;
75 int ret = 0;
76
77 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
78 GFP_KERNEL);
79
80 if (!tb)
81 return -ENOMEM;
82
83 ret = nla_parse_nested_deprecated(tb,
84 l4proto->ctnl_timeout.nlattr_max,
85 attr,
86 l4proto->ctnl_timeout.nla_policy,
87 NULL);
88 if (ret < 0)
89 goto err;
90
91 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
92
93err:
94 kfree(tb);
95 return ret;
96}
97
98static int cttimeout_new_timeout(struct sk_buff *skb,
99 const struct nfnl_info *info,
100 const struct nlattr * const cda[])
101{
102 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
103 __u16 l3num;
104 __u8 l4num;
105 const struct nf_conntrack_l4proto *l4proto;
106 struct ctnl_timeout *timeout, *matching = NULL;
107 char *name;
108 int ret;
109
110 if (!cda[CTA_TIMEOUT_NAME] ||
111 !cda[CTA_TIMEOUT_L3PROTO] ||
112 !cda[CTA_TIMEOUT_L4PROTO] ||
113 !cda[CTA_TIMEOUT_DATA])
114 return -EINVAL;
115
116 name = nla_data(cda[CTA_TIMEOUT_NAME]);
117 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
118 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
119
120 list_for_each_entry(timeout, &pernet->nfct_timeout_list, head) {
121 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
122 continue;
123
124 if (info->nlh->nlmsg_flags & NLM_F_EXCL)
125 return -EEXIST;
126
127 matching = timeout;
128 break;
129 }
130
131 if (matching) {
132 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
133 /* You cannot replace one timeout policy by another of
134 * different kind, sorry.
135 */
136 if (matching->timeout.l3num != l3num ||
137 matching->timeout.l4proto->l4proto != l4num)
138 return -EINVAL;
139
140 return ctnl_timeout_parse_policy(&matching->timeout.data,
141 matching->timeout.l4proto,
142 info->net,
143 cda[CTA_TIMEOUT_DATA]);
144 }
145
146 return -EBUSY;
147 }
148
149 l4proto = nf_ct_l4proto_find(l4num);
150
151 /* This protocol is not supportted, skip. */
152 if (l4proto->l4proto != l4num) {
153 ret = -EOPNOTSUPP;
154 goto err_proto_put;
155 }
156
157 timeout = kzalloc(sizeof(struct ctnl_timeout) +
158 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
159 if (timeout == NULL) {
160 ret = -ENOMEM;
161 goto err_proto_put;
162 }
163
164 ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto,
165 info->net, cda[CTA_TIMEOUT_DATA]);
166 if (ret < 0)
167 goto err;
168
169 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
170 timeout->timeout.l3num = l3num;
171 timeout->timeout.l4proto = l4proto;
172 refcount_set(&timeout->refcnt, 1);
173 __module_get(THIS_MODULE);
174 list_add_tail_rcu(&timeout->head, &pernet->nfct_timeout_list);
175
176 return 0;
177err:
178 kfree(timeout);
179err_proto_put:
180 return ret;
181}
182
183static int
184ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
185 int event, struct ctnl_timeout *timeout)
186{
187 struct nlmsghdr *nlh;
188 unsigned int flags = portid ? NLM_F_MULTI : 0;
189 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
190 struct nlattr *nest_parms;
191 int ret;
192
193 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
194 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
195 NFNETLINK_V0, 0);
196 if (!nlh)
197 goto nlmsg_failure;
198
199 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
200 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
201 htons(timeout->timeout.l3num)) ||
202 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
203 nla_put_be32(skb, CTA_TIMEOUT_USE,
204 htonl(refcount_read(&timeout->refcnt))))
205 goto nla_put_failure;
206
207 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
208 if (!nest_parms)
209 goto nla_put_failure;
210
211 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
212 if (ret < 0)
213 goto nla_put_failure;
214
215 nla_nest_end(skb, nest_parms);
216
217 nlmsg_end(skb, nlh);
218 return skb->len;
219
220nlmsg_failure:
221nla_put_failure:
222 nlmsg_cancel(skb, nlh);
223 return -1;
224}
225
226static int
227ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
228{
229 struct nfct_timeout_pernet *pernet;
230 struct net *net = sock_net(skb->sk);
231 struct ctnl_timeout *cur, *last;
232
233 if (cb->args[2])
234 return 0;
235
236 last = (struct ctnl_timeout *)cb->args[1];
237 if (cb->args[1])
238 cb->args[1] = 0;
239
240 rcu_read_lock();
241 pernet = nfct_timeout_pernet(net);
242 list_for_each_entry_rcu(cur, &pernet->nfct_timeout_list, head) {
243 if (last) {
244 if (cur != last)
245 continue;
246
247 last = NULL;
248 }
249 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
250 cb->nlh->nlmsg_seq,
251 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
252 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
253 cb->args[1] = (unsigned long)cur;
254 break;
255 }
256 }
257 if (!cb->args[1])
258 cb->args[2] = 1;
259 rcu_read_unlock();
260 return skb->len;
261}
262
263static int cttimeout_get_timeout(struct sk_buff *skb,
264 const struct nfnl_info *info,
265 const struct nlattr * const cda[])
266{
267 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
268 int ret = -ENOENT;
269 char *name;
270 struct ctnl_timeout *cur;
271
272 if (info->nlh->nlmsg_flags & NLM_F_DUMP) {
273 struct netlink_dump_control c = {
274 .dump = ctnl_timeout_dump,
275 };
276 return netlink_dump_start(info->sk, skb, info->nlh, &c);
277 }
278
279 if (!cda[CTA_TIMEOUT_NAME])
280 return -EINVAL;
281 name = nla_data(cda[CTA_TIMEOUT_NAME]);
282
283 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
284 struct sk_buff *skb2;
285
286 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
287 continue;
288
289 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
290 if (skb2 == NULL) {
291 ret = -ENOMEM;
292 break;
293 }
294
295 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
296 info->nlh->nlmsg_seq,
297 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
298 IPCTNL_MSG_TIMEOUT_NEW, cur);
299 if (ret <= 0) {
300 kfree_skb(skb2);
301 break;
302 }
303
304 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
305 break;
306 }
307
308 return ret;
309}
310
311/* try to delete object, fail if it is still in use. */
312static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
313{
314 int ret = 0;
315
316 /* We want to avoid races with ctnl_timeout_put. So only when the
317 * current refcnt is 1, we decrease it to 0.
318 */
319 if (refcount_dec_if_one(&timeout->refcnt)) {
320 /* We are protected by nfnl mutex. */
321 list_del_rcu(&timeout->head);
322 nf_ct_untimeout(net, &timeout->timeout);
323 kfree_rcu(timeout, rcu_head);
324 } else {
325 ret = -EBUSY;
326 }
327 return ret;
328}
329
330static int cttimeout_del_timeout(struct sk_buff *skb,
331 const struct nfnl_info *info,
332 const struct nlattr * const cda[])
333{
334 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
335 struct ctnl_timeout *cur, *tmp;
336 int ret = -ENOENT;
337 char *name;
338
339 if (!cda[CTA_TIMEOUT_NAME]) {
340 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list,
341 head)
342 ctnl_timeout_try_del(info->net, cur);
343
344 return 0;
345 }
346 name = nla_data(cda[CTA_TIMEOUT_NAME]);
347
348 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
349 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
350 continue;
351
352 ret = ctnl_timeout_try_del(info->net, cur);
353 if (ret < 0)
354 return ret;
355
356 break;
357 }
358 return ret;
359}
360
361static int cttimeout_default_set(struct sk_buff *skb,
362 const struct nfnl_info *info,
363 const struct nlattr * const cda[])
364{
365 const struct nf_conntrack_l4proto *l4proto;
366 __u8 l4num;
367 int ret;
368
369 if (!cda[CTA_TIMEOUT_L3PROTO] ||
370 !cda[CTA_TIMEOUT_L4PROTO] ||
371 !cda[CTA_TIMEOUT_DATA])
372 return -EINVAL;
373
374 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
375 l4proto = nf_ct_l4proto_find(l4num);
376
377 /* This protocol is not supported, skip. */
378 if (l4proto->l4proto != l4num) {
379 ret = -EOPNOTSUPP;
380 goto err;
381 }
382
383 ret = ctnl_timeout_parse_policy(NULL, l4proto, info->net,
384 cda[CTA_TIMEOUT_DATA]);
385 if (ret < 0)
386 goto err;
387
388 return 0;
389err:
390 return ret;
391}
392
393static int
394cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
395 u32 seq, u32 type, int event, u16 l3num,
396 const struct nf_conntrack_l4proto *l4proto,
397 const unsigned int *timeouts)
398{
399 struct nlmsghdr *nlh;
400 unsigned int flags = portid ? NLM_F_MULTI : 0;
401 struct nlattr *nest_parms;
402 int ret;
403
404 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
405 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
406 NFNETLINK_V0, 0);
407 if (!nlh)
408 goto nlmsg_failure;
409
410 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
411 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
412 goto nla_put_failure;
413
414 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
415 if (!nest_parms)
416 goto nla_put_failure;
417
418 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
419 if (ret < 0)
420 goto nla_put_failure;
421
422 nla_nest_end(skb, nest_parms);
423
424 nlmsg_end(skb, nlh);
425 return skb->len;
426
427nlmsg_failure:
428nla_put_failure:
429 nlmsg_cancel(skb, nlh);
430 return -1;
431}
432
433static int cttimeout_default_get(struct sk_buff *skb,
434 const struct nfnl_info *info,
435 const struct nlattr * const cda[])
436{
437 const struct nf_conntrack_l4proto *l4proto;
438 unsigned int *timeouts = NULL;
439 struct sk_buff *skb2;
440 __u16 l3num;
441 __u8 l4num;
442 int ret;
443
444 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
445 return -EINVAL;
446
447 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
448 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
449 l4proto = nf_ct_l4proto_find(l4num);
450
451 if (l4proto->l4proto != l4num)
452 return -EOPNOTSUPP;
453
454 switch (l4proto->l4proto) {
455 case IPPROTO_ICMP:
456 timeouts = &nf_icmp_pernet(info->net)->timeout;
457 break;
458 case IPPROTO_TCP:
459 timeouts = nf_tcp_pernet(info->net)->timeouts;
460 break;
461 case IPPROTO_UDP:
462 case IPPROTO_UDPLITE:
463 timeouts = nf_udp_pernet(info->net)->timeouts;
464 break;
465 case IPPROTO_DCCP:
466#ifdef CONFIG_NF_CT_PROTO_DCCP
467 timeouts = nf_dccp_pernet(info->net)->dccp_timeout;
468#endif
469 break;
470 case IPPROTO_ICMPV6:
471 timeouts = &nf_icmpv6_pernet(info->net)->timeout;
472 break;
473 case IPPROTO_SCTP:
474#ifdef CONFIG_NF_CT_PROTO_SCTP
475 timeouts = nf_sctp_pernet(info->net)->timeouts;
476#endif
477 break;
478 case IPPROTO_GRE:
479#ifdef CONFIG_NF_CT_PROTO_GRE
480 timeouts = nf_gre_pernet(info->net)->timeouts;
481#endif
482 break;
483 case 255:
484 timeouts = &nf_generic_pernet(info->net)->timeout;
485 break;
486 default:
487 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
488 break;
489 }
490
491 if (!timeouts)
492 return -EOPNOTSUPP;
493
494 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
495 if (!skb2)
496 return -ENOMEM;
497
498 ret = cttimeout_default_fill_info(info->net, skb2,
499 NETLINK_CB(skb).portid,
500 info->nlh->nlmsg_seq,
501 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
502 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
503 l3num, l4proto, timeouts);
504 if (ret <= 0) {
505 kfree_skb(skb2);
506 return -ENOMEM;
507 }
508
509 return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
510}
511
512static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
513 const char *name)
514{
515 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
516 struct ctnl_timeout *timeout, *matching = NULL;
517
518 list_for_each_entry_rcu(timeout, &pernet->nfct_timeout_list, head) {
519 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
520 continue;
521
522 if (!refcount_inc_not_zero(&timeout->refcnt))
523 goto err;
524 matching = timeout;
525 break;
526 }
527err:
528 return matching ? &matching->timeout : NULL;
529}
530
531static void ctnl_timeout_put(struct nf_ct_timeout *t)
532{
533 struct ctnl_timeout *timeout =
534 container_of(t, struct ctnl_timeout, timeout);
535
536 if (refcount_dec_and_test(&timeout->refcnt)) {
537 kfree_rcu(timeout, rcu_head);
538 module_put(THIS_MODULE);
539 }
540}
541
542static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
543 [IPCTNL_MSG_TIMEOUT_NEW] = {
544 .call = cttimeout_new_timeout,
545 .type = NFNL_CB_MUTEX,
546 .attr_count = CTA_TIMEOUT_MAX,
547 .policy = cttimeout_nla_policy
548 },
549 [IPCTNL_MSG_TIMEOUT_GET] = {
550 .call = cttimeout_get_timeout,
551 .type = NFNL_CB_MUTEX,
552 .attr_count = CTA_TIMEOUT_MAX,
553 .policy = cttimeout_nla_policy
554 },
555 [IPCTNL_MSG_TIMEOUT_DELETE] = {
556 .call = cttimeout_del_timeout,
557 .type = NFNL_CB_MUTEX,
558 .attr_count = CTA_TIMEOUT_MAX,
559 .policy = cttimeout_nla_policy
560 },
561 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET] = {
562 .call = cttimeout_default_set,
563 .type = NFNL_CB_MUTEX,
564 .attr_count = CTA_TIMEOUT_MAX,
565 .policy = cttimeout_nla_policy
566 },
567 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET] = {
568 .call = cttimeout_default_get,
569 .type = NFNL_CB_MUTEX,
570 .attr_count = CTA_TIMEOUT_MAX,
571 .policy = cttimeout_nla_policy
572 },
573};
574
575static const struct nfnetlink_subsystem cttimeout_subsys = {
576 .name = "conntrack_timeout",
577 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
578 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
579 .cb = cttimeout_cb,
580};
581
582MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
583
584static int __net_init cttimeout_net_init(struct net *net)
585{
586 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
587
588 INIT_LIST_HEAD(&pernet->nfct_timeout_list);
589 INIT_LIST_HEAD(&pernet->nfct_timeout_freelist);
590
591 return 0;
592}
593
594static void __net_exit cttimeout_net_pre_exit(struct net *net)
595{
596 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
597 struct ctnl_timeout *cur, *tmp;
598
599 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list, head) {
600 list_del_rcu(&cur->head);
601 list_add(&cur->free_head, &pernet->nfct_timeout_freelist);
602 }
603
604 /* core calls synchronize_rcu() after this */
605}
606
607static void __net_exit cttimeout_net_exit(struct net *net)
608{
609 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
610 struct ctnl_timeout *cur, *tmp;
611
612 if (list_empty(&pernet->nfct_timeout_freelist))
613 return;
614
615 nf_ct_untimeout(net, NULL);
616
617 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_freelist, free_head) {
618 list_del(&cur->free_head);
619
620 if (refcount_dec_and_test(&cur->refcnt))
621 kfree_rcu(cur, rcu_head);
622 }
623}
624
625static struct pernet_operations cttimeout_ops = {
626 .init = cttimeout_net_init,
627 .pre_exit = cttimeout_net_pre_exit,
628 .exit = cttimeout_net_exit,
629 .id = &nfct_timeout_id,
630 .size = sizeof(struct nfct_timeout_pernet),
631};
632
633static const struct nf_ct_timeout_hooks hooks = {
634 .timeout_find_get = ctnl_timeout_find_get,
635 .timeout_put = ctnl_timeout_put,
636};
637
638static int __init cttimeout_init(void)
639{
640 int ret;
641
642 ret = register_pernet_subsys(&cttimeout_ops);
643 if (ret < 0)
644 return ret;
645
646 ret = nfnetlink_subsys_register(&cttimeout_subsys);
647 if (ret < 0) {
648 pr_err("cttimeout_init: cannot register cttimeout with "
649 "nfnetlink.\n");
650 goto err_out;
651 }
652 RCU_INIT_POINTER(nf_ct_timeout_hook, &hooks);
653 return 0;
654
655err_out:
656 unregister_pernet_subsys(&cttimeout_ops);
657 return ret;
658}
659
660static int untimeout(struct nf_conn *ct, void *timeout)
661{
662 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
663
664 if (timeout_ext)
665 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
666
667 return 0;
668}
669
670static void __exit cttimeout_exit(void)
671{
672 nfnetlink_subsys_unregister(&cttimeout_subsys);
673
674 unregister_pernet_subsys(&cttimeout_ops);
675 RCU_INIT_POINTER(nf_ct_timeout_hook, NULL);
676
677 nf_ct_iterate_destroy(untimeout, NULL);
678}
679
680module_init(cttimeout_init);
681module_exit(cttimeout_exit);