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,
51 const struct nf_conntrack_l4proto *l4proto,
52 struct net *net, const struct nlattr *attr)
57 if (!l4proto->ctnl_timeout.nlattr_to_obj)
60 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
66 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, attr,
67 l4proto->ctnl_timeout.nla_policy, NULL);
71 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
78 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
80 const struct nlmsghdr *nlh,
81 const struct nlattr * const cda[],
82 struct netlink_ext_ack *extack)
86 const struct nf_conntrack_l4proto *l4proto;
87 struct ctnl_timeout *timeout, *matching = NULL;
91 if (!cda[CTA_TIMEOUT_NAME] ||
92 !cda[CTA_TIMEOUT_L3PROTO] ||
93 !cda[CTA_TIMEOUT_L4PROTO] ||
94 !cda[CTA_TIMEOUT_DATA])
97 name = nla_data(cda[CTA_TIMEOUT_NAME]);
98 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
99 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
101 list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
102 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
105 if (nlh->nlmsg_flags & NLM_F_EXCL)
113 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
114 /* You cannot replace one timeout policy by another of
115 * different kind, sorry.
117 if (matching->l3num != l3num ||
118 matching->l4proto->l4proto != l4num)
121 return ctnl_timeout_parse_policy(&matching->data,
122 matching->l4proto, net,
123 cda[CTA_TIMEOUT_DATA]);
129 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
131 /* This protocol is not supportted, skip. */
132 if (l4proto->l4proto != l4num) {
137 timeout = kzalloc(sizeof(struct ctnl_timeout) +
138 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
139 if (timeout == NULL) {
144 ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
145 cda[CTA_TIMEOUT_DATA]);
149 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
150 timeout->l3num = l3num;
151 timeout->l4proto = l4proto;
152 refcount_set(&timeout->refcnt, 1);
153 list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
159 nf_ct_l4proto_put(l4proto);
164 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
165 int event, struct ctnl_timeout *timeout)
167 struct nlmsghdr *nlh;
168 struct nfgenmsg *nfmsg;
169 unsigned int flags = portid ? NLM_F_MULTI : 0;
170 const struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
172 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
173 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
177 nfmsg = nlmsg_data(nlh);
178 nfmsg->nfgen_family = AF_UNSPEC;
179 nfmsg->version = NFNETLINK_V0;
182 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
183 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) ||
184 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) ||
185 nla_put_be32(skb, CTA_TIMEOUT_USE,
186 htonl(refcount_read(&timeout->refcnt))))
187 goto nla_put_failure;
189 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
190 struct nlattr *nest_parms;
193 nest_parms = nla_nest_start(skb,
194 CTA_TIMEOUT_DATA | NLA_F_NESTED);
196 goto nla_put_failure;
198 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
200 goto nla_put_failure;
202 nla_nest_end(skb, nest_parms);
210 nlmsg_cancel(skb, nlh);
215 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
217 struct net *net = sock_net(skb->sk);
218 struct ctnl_timeout *cur, *last;
223 last = (struct ctnl_timeout *)cb->args[1];
228 list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
235 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
237 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
238 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
239 cb->args[1] = (unsigned long)cur;
249 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
251 const struct nlmsghdr *nlh,
252 const struct nlattr * const cda[],
253 struct netlink_ext_ack *extack)
257 struct ctnl_timeout *cur;
259 if (nlh->nlmsg_flags & NLM_F_DUMP) {
260 struct netlink_dump_control c = {
261 .dump = ctnl_timeout_dump,
263 return netlink_dump_start(ctnl, skb, nlh, &c);
266 if (!cda[CTA_TIMEOUT_NAME])
268 name = nla_data(cda[CTA_TIMEOUT_NAME]);
270 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
271 struct sk_buff *skb2;
273 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
276 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
282 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
284 NFNL_MSG_TYPE(nlh->nlmsg_type),
285 IPCTNL_MSG_TIMEOUT_NEW, cur);
290 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
295 /* this avoids a loop in nfnetlink. */
296 return ret == -EAGAIN ? -ENOBUFS : ret;
301 static int untimeout(struct nf_conn *ct, void *timeout)
303 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
305 if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
306 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
308 /* We are not intended to delete this conntrack. */
312 static void ctnl_untimeout(struct net *net, struct ctnl_timeout *timeout)
314 nf_ct_iterate_cleanup_net(net, untimeout, timeout, 0, 0);
317 /* try to delete object, fail if it is still in use. */
318 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
322 /* We want to avoid races with ctnl_timeout_put. So only when the
323 * current refcnt is 1, we decrease it to 0.
325 if (refcount_dec_if_one(&timeout->refcnt)) {
326 /* We are protected by nfnl mutex. */
327 list_del_rcu(&timeout->head);
328 nf_ct_l4proto_put(timeout->l4proto);
329 ctnl_untimeout(net, timeout);
330 kfree_rcu(timeout, rcu_head);
337 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
339 const struct nlmsghdr *nlh,
340 const struct nlattr * const cda[],
341 struct netlink_ext_ack *extack)
343 struct ctnl_timeout *cur, *tmp;
347 if (!cda[CTA_TIMEOUT_NAME]) {
348 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
350 ctnl_timeout_try_del(net, cur);
354 name = nla_data(cda[CTA_TIMEOUT_NAME]);
356 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
357 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
360 ret = ctnl_timeout_try_del(net, cur);
369 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
371 const struct nlmsghdr *nlh,
372 const struct nlattr * const cda[],
373 struct netlink_ext_ack *extack)
375 const struct nf_conntrack_l4proto *l4proto;
376 unsigned int *timeouts;
381 if (!cda[CTA_TIMEOUT_L3PROTO] ||
382 !cda[CTA_TIMEOUT_L4PROTO] ||
383 !cda[CTA_TIMEOUT_DATA])
386 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
387 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
388 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
390 /* This protocol is not supported, skip. */
391 if (l4proto->l4proto != l4num) {
396 timeouts = l4proto->get_timeouts(net);
398 ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
399 cda[CTA_TIMEOUT_DATA]);
403 nf_ct_l4proto_put(l4proto);
406 nf_ct_l4proto_put(l4proto);
411 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
412 u32 seq, u32 type, int event,
413 const struct nf_conntrack_l4proto *l4proto)
415 struct nlmsghdr *nlh;
416 struct nfgenmsg *nfmsg;
417 unsigned int flags = portid ? NLM_F_MULTI : 0;
419 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
420 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
424 nfmsg = nlmsg_data(nlh);
425 nfmsg->nfgen_family = AF_UNSPEC;
426 nfmsg->version = NFNETLINK_V0;
429 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
430 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
431 goto nla_put_failure;
433 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
434 struct nlattr *nest_parms;
435 unsigned int *timeouts = l4proto->get_timeouts(net);
438 nest_parms = nla_nest_start(skb,
439 CTA_TIMEOUT_DATA | NLA_F_NESTED);
441 goto nla_put_failure;
443 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
445 goto nla_put_failure;
447 nla_nest_end(skb, nest_parms);
455 nlmsg_cancel(skb, nlh);
459 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
461 const struct nlmsghdr *nlh,
462 const struct nlattr * const cda[],
463 struct netlink_ext_ack *extack)
465 const struct nf_conntrack_l4proto *l4proto;
466 struct sk_buff *skb2;
471 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
474 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
475 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
476 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
478 /* This protocol is not supported, skip. */
479 if (l4proto->l4proto != l4num) {
484 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
490 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
492 NFNL_MSG_TYPE(nlh->nlmsg_type),
493 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
500 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
504 /* this avoids a loop in nfnetlink. */
505 return ret == -EAGAIN ? -ENOBUFS : ret;
507 nf_ct_l4proto_put(l4proto);
511 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
512 static struct ctnl_timeout *
513 ctnl_timeout_find_get(struct net *net, const char *name)
515 struct ctnl_timeout *timeout, *matching = NULL;
517 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
518 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
521 if (!try_module_get(THIS_MODULE))
524 if (!refcount_inc_not_zero(&timeout->refcnt)) {
525 module_put(THIS_MODULE);
535 static void ctnl_timeout_put(struct ctnl_timeout *timeout)
537 if (refcount_dec_and_test(&timeout->refcnt))
538 kfree_rcu(timeout, rcu_head);
540 module_put(THIS_MODULE);
542 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
544 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
545 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
546 .attr_count = CTA_TIMEOUT_MAX,
547 .policy = cttimeout_nla_policy },
548 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
549 .attr_count = CTA_TIMEOUT_MAX,
550 .policy = cttimeout_nla_policy },
551 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
552 .attr_count = CTA_TIMEOUT_MAX,
553 .policy = cttimeout_nla_policy },
554 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
555 .attr_count = CTA_TIMEOUT_MAX,
556 .policy = cttimeout_nla_policy },
557 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
558 .attr_count = CTA_TIMEOUT_MAX,
559 .policy = cttimeout_nla_policy },
562 static const struct nfnetlink_subsystem cttimeout_subsys = {
563 .name = "conntrack_timeout",
564 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
565 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
569 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
571 static int __net_init cttimeout_net_init(struct net *net)
573 INIT_LIST_HEAD(&net->nfct_timeout_list);
578 static void __net_exit cttimeout_net_exit(struct net *net)
580 struct ctnl_timeout *cur, *tmp;
582 nf_ct_unconfirmed_destroy(net);
583 ctnl_untimeout(net, NULL);
585 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
586 list_del_rcu(&cur->head);
587 nf_ct_l4proto_put(cur->l4proto);
589 if (refcount_dec_and_test(&cur->refcnt))
590 kfree_rcu(cur, rcu_head);
594 static struct pernet_operations cttimeout_ops = {
595 .init = cttimeout_net_init,
596 .exit = cttimeout_net_exit,
599 static int __init cttimeout_init(void)
603 ret = register_pernet_subsys(&cttimeout_ops);
607 ret = nfnetlink_subsys_register(&cttimeout_subsys);
609 pr_err("cttimeout_init: cannot register cttimeout with "
613 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
614 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
615 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
616 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
620 unregister_pernet_subsys(&cttimeout_ops);
624 static void __exit cttimeout_exit(void)
626 nfnetlink_subsys_unregister(&cttimeout_subsys);
628 unregister_pernet_subsys(&cttimeout_ops);
629 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
630 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
631 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
633 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
636 module_init(cttimeout_init);
637 module_exit(cttimeout_exit);