2 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
3 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
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).
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>
24 #include <linux/netfilter.h>
25 #include <net/netlink.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>
34 #include <linux/netfilter/nfnetlink.h>
35 #include <linux/netfilter/nfnetlink_cttimeout.h>
37 MODULE_LICENSE("GPL");
38 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
39 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
41 static 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 },
50 ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
51 struct net *net, const struct nlattr *attr)
55 if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
56 struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
58 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
59 attr, l4proto->ctnl_timeout.nla_policy);
63 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
68 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
70 const struct nlmsghdr *nlh,
71 const struct nlattr * const cda[])
75 struct nf_conntrack_l4proto *l4proto;
76 struct ctnl_timeout *timeout, *matching = NULL;
80 if (!cda[CTA_TIMEOUT_NAME] ||
81 !cda[CTA_TIMEOUT_L3PROTO] ||
82 !cda[CTA_TIMEOUT_L4PROTO] ||
83 !cda[CTA_TIMEOUT_DATA])
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]);
90 list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
91 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
94 if (nlh->nlmsg_flags & NLM_F_EXCL)
102 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
103 /* You cannot replace one timeout policy by another of
104 * different kind, sorry.
106 if (matching->l3num != l3num ||
107 matching->l4proto->l4proto != l4num)
110 return ctnl_timeout_parse_policy(&matching->data,
111 matching->l4proto, net,
112 cda[CTA_TIMEOUT_DATA]);
118 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
120 /* This protocol is not supportted, skip. */
121 if (l4proto->l4proto != l4num) {
126 timeout = kzalloc(sizeof(struct ctnl_timeout) +
127 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
128 if (timeout == NULL) {
133 ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
134 cda[CTA_TIMEOUT_DATA]);
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);
148 nf_ct_l4proto_put(l4proto);
153 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
154 int event, struct ctnl_timeout *timeout)
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;
161 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
162 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
166 nfmsg = nlmsg_data(nlh);
167 nfmsg->nfgen_family = AF_UNSPEC;
168 nfmsg->version = NFNETLINK_V0;
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;
178 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
179 struct nlattr *nest_parms;
182 nest_parms = nla_nest_start(skb,
183 CTA_TIMEOUT_DATA | NLA_F_NESTED);
185 goto nla_put_failure;
187 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
189 goto nla_put_failure;
191 nla_nest_end(skb, nest_parms);
199 nlmsg_cancel(skb, nlh);
204 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
206 struct net *net = sock_net(skb->sk);
207 struct ctnl_timeout *cur, *last;
212 last = (struct ctnl_timeout *)cb->args[1];
217 list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
224 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
226 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
227 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
228 cb->args[1] = (unsigned long)cur;
238 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
240 const struct nlmsghdr *nlh,
241 const struct nlattr * const cda[])
245 struct ctnl_timeout *cur;
247 if (nlh->nlmsg_flags & NLM_F_DUMP) {
248 struct netlink_dump_control c = {
249 .dump = ctnl_timeout_dump,
251 return netlink_dump_start(ctnl, skb, nlh, &c);
254 if (!cda[CTA_TIMEOUT_NAME])
256 name = nla_data(cda[CTA_TIMEOUT_NAME]);
258 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
259 struct sk_buff *skb2;
261 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
264 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
270 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
272 NFNL_MSG_TYPE(nlh->nlmsg_type),
273 IPCTNL_MSG_TIMEOUT_NEW, cur);
278 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
283 /* this avoids a loop in nfnetlink. */
284 return ret == -EAGAIN ? -ENOBUFS : ret;
289 static void untimeout(struct nf_conntrack_tuple_hash *i,
290 struct ctnl_timeout *timeout)
292 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
293 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
295 if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
296 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
299 static void ctnl_untimeout(struct net *net, struct ctnl_timeout *timeout)
301 struct nf_conntrack_tuple_hash *h;
302 const struct hlist_nulls_node *nn;
303 unsigned int last_hsize;
307 for_each_possible_cpu(cpu) {
308 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
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);
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) {
327 hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
328 untimeout(h, timeout);
334 /* try to delete object, fail if it is still in use. */
335 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
339 /* We want to avoid races with ctnl_timeout_put. So only when the
340 * current refcnt is 1, we decrease it to 0.
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);
354 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
356 const struct nlmsghdr *nlh,
357 const struct nlattr * const cda[])
359 struct ctnl_timeout *cur, *tmp;
363 if (!cda[CTA_TIMEOUT_NAME]) {
364 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
366 ctnl_timeout_try_del(net, cur);
370 name = nla_data(cda[CTA_TIMEOUT_NAME]);
372 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
373 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
376 ret = ctnl_timeout_try_del(net, cur);
385 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
387 const struct nlmsghdr *nlh,
388 const struct nlattr * const cda[])
392 struct nf_conntrack_l4proto *l4proto;
393 unsigned int *timeouts;
396 if (!cda[CTA_TIMEOUT_L3PROTO] ||
397 !cda[CTA_TIMEOUT_L4PROTO] ||
398 !cda[CTA_TIMEOUT_DATA])
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);
405 /* This protocol is not supported, skip. */
406 if (l4proto->l4proto != l4num) {
411 timeouts = l4proto->get_timeouts(net);
413 ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
414 cda[CTA_TIMEOUT_DATA]);
418 nf_ct_l4proto_put(l4proto);
421 nf_ct_l4proto_put(l4proto);
426 cttimeout_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)
430 struct nlmsghdr *nlh;
431 struct nfgenmsg *nfmsg;
432 unsigned int flags = portid ? NLM_F_MULTI : 0;
434 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
435 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
439 nfmsg = nlmsg_data(nlh);
440 nfmsg->nfgen_family = AF_UNSPEC;
441 nfmsg->version = NFNETLINK_V0;
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;
448 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
449 struct nlattr *nest_parms;
450 unsigned int *timeouts = l4proto->get_timeouts(net);
453 nest_parms = nla_nest_start(skb,
454 CTA_TIMEOUT_DATA | NLA_F_NESTED);
456 goto nla_put_failure;
458 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
460 goto nla_put_failure;
462 nla_nest_end(skb, nest_parms);
470 nlmsg_cancel(skb, nlh);
474 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
476 const struct nlmsghdr *nlh,
477 const struct nlattr * const cda[])
481 struct nf_conntrack_l4proto *l4proto;
482 struct sk_buff *skb2;
485 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
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);
492 /* This protocol is not supported, skip. */
493 if (l4proto->l4proto != l4num) {
498 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
504 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
506 NFNL_MSG_TYPE(nlh->nlmsg_type),
507 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
514 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
518 /* this avoids a loop in nfnetlink. */
519 return ret == -EAGAIN ? -ENOBUFS : ret;
521 nf_ct_l4proto_put(l4proto);
525 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
526 static struct ctnl_timeout *
527 ctnl_timeout_find_get(struct net *net, const char *name)
529 struct ctnl_timeout *timeout, *matching = NULL;
532 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
533 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
536 if (!try_module_get(THIS_MODULE))
539 if (!atomic_inc_not_zero(&timeout->refcnt)) {
540 module_put(THIS_MODULE);
551 static void ctnl_timeout_put(struct ctnl_timeout *timeout)
553 if (atomic_dec_and_test(&timeout->refcnt))
554 kfree_rcu(timeout, rcu_head);
556 module_put(THIS_MODULE);
558 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
560 static 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 },
578 static const struct nfnetlink_subsystem cttimeout_subsys = {
579 .name = "conntrack_timeout",
580 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
581 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
585 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
587 static int __net_init cttimeout_net_init(struct net *net)
589 INIT_LIST_HEAD(&net->nfct_timeout_list);
594 static void __net_exit cttimeout_net_exit(struct net *net)
596 struct ctnl_timeout *cur, *tmp;
598 ctnl_untimeout(net, NULL);
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);
604 if (atomic_dec_and_test(&cur->refcnt))
605 kfree_rcu(cur, rcu_head);
609 static struct pernet_operations cttimeout_ops = {
610 .init = cttimeout_net_init,
611 .exit = cttimeout_net_exit,
614 static int __init cttimeout_init(void)
618 ret = register_pernet_subsys(&cttimeout_ops);
622 ret = nfnetlink_subsys_register(&cttimeout_subsys);
624 pr_err("cttimeout_init: cannot register cttimeout with "
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 */
635 unregister_pernet_subsys(&cttimeout_ops);
639 static void __exit cttimeout_exit(void)
641 pr_info("cttimeout: unregistering from nfnetlink.\n");
643 nfnetlink_subsys_unregister(&cttimeout_subsys);
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);
650 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
653 module_init(cttimeout_init);
654 module_exit(cttimeout_exit);