1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
4 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
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>
21 #include <linux/netfilter.h>
22 #include <net/netlink.h>
23 #include <net/netns/generic.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>
31 #include <linux/netfilter/nfnetlink.h>
32 #include <linux/netfilter/nfnetlink_cttimeout.h>
34 static unsigned int nfct_timeout_id __read_mostly;
36 struct nfct_timeout_pernet {
37 struct list_head nfct_timeout_list;
40 MODULE_LICENSE("GPL");
41 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
42 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
44 static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
45 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
46 .len = CTNL_TIMEOUT_NAME_MAX - 1},
47 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
48 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
49 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
52 static struct nfct_timeout_pernet *nfct_timeout_pernet(struct net *net)
54 return net_generic(net, nfct_timeout_id);
58 ctnl_timeout_parse_policy(void *timeout,
59 const struct nf_conntrack_l4proto *l4proto,
60 struct net *net, const struct nlattr *attr)
65 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
71 ret = nla_parse_nested_deprecated(tb,
72 l4proto->ctnl_timeout.nlattr_max,
74 l4proto->ctnl_timeout.nla_policy,
79 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
86 static int cttimeout_new_timeout(struct sk_buff *skb,
87 const struct nfnl_info *info,
88 const struct nlattr * const cda[])
90 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
93 const struct nf_conntrack_l4proto *l4proto;
94 struct ctnl_timeout *timeout, *matching = NULL;
98 if (!cda[CTA_TIMEOUT_NAME] ||
99 !cda[CTA_TIMEOUT_L3PROTO] ||
100 !cda[CTA_TIMEOUT_L4PROTO] ||
101 !cda[CTA_TIMEOUT_DATA])
104 name = nla_data(cda[CTA_TIMEOUT_NAME]);
105 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
106 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
108 list_for_each_entry(timeout, &pernet->nfct_timeout_list, head) {
109 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
112 if (info->nlh->nlmsg_flags & NLM_F_EXCL)
120 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
121 /* You cannot replace one timeout policy by another of
122 * different kind, sorry.
124 if (matching->timeout.l3num != l3num ||
125 matching->timeout.l4proto->l4proto != l4num)
128 return ctnl_timeout_parse_policy(&matching->timeout.data,
129 matching->timeout.l4proto,
131 cda[CTA_TIMEOUT_DATA]);
137 l4proto = nf_ct_l4proto_find(l4num);
139 /* This protocol is not supportted, skip. */
140 if (l4proto->l4proto != l4num) {
145 timeout = kzalloc(sizeof(struct ctnl_timeout) +
146 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
147 if (timeout == NULL) {
152 ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto,
153 info->net, cda[CTA_TIMEOUT_DATA]);
157 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
158 timeout->timeout.l3num = l3num;
159 timeout->timeout.l4proto = l4proto;
160 refcount_set(&timeout->refcnt, 1);
161 list_add_tail_rcu(&timeout->head, &pernet->nfct_timeout_list);
171 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
172 int event, struct ctnl_timeout *timeout)
174 struct nlmsghdr *nlh;
175 unsigned int flags = portid ? NLM_F_MULTI : 0;
176 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
177 struct nlattr *nest_parms;
180 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
181 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
186 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
187 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
188 htons(timeout->timeout.l3num)) ||
189 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
190 nla_put_be32(skb, CTA_TIMEOUT_USE,
191 htonl(refcount_read(&timeout->refcnt))))
192 goto nla_put_failure;
194 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
196 goto nla_put_failure;
198 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
200 goto nla_put_failure;
202 nla_nest_end(skb, nest_parms);
209 nlmsg_cancel(skb, nlh);
214 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
216 struct nfct_timeout_pernet *pernet;
217 struct net *net = sock_net(skb->sk);
218 struct ctnl_timeout *cur, *last;
223 last = (struct ctnl_timeout *)cb->args[1];
228 pernet = nfct_timeout_pernet(net);
229 list_for_each_entry_rcu(cur, &pernet->nfct_timeout_list, head) {
236 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
238 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
239 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
240 cb->args[1] = (unsigned long)cur;
250 static int cttimeout_get_timeout(struct sk_buff *skb,
251 const struct nfnl_info *info,
252 const struct nlattr * const cda[])
254 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
257 struct ctnl_timeout *cur;
259 if (info->nlh->nlmsg_flags & NLM_F_DUMP) {
260 struct netlink_dump_control c = {
261 .dump = ctnl_timeout_dump,
263 return netlink_dump_start(info->sk, skb, info->nlh, &c);
266 if (!cda[CTA_TIMEOUT_NAME])
268 name = nla_data(cda[CTA_TIMEOUT_NAME]);
270 list_for_each_entry(cur, &pernet->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,
283 info->nlh->nlmsg_seq,
284 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
285 IPCTNL_MSG_TIMEOUT_NEW, cur);
290 ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
295 /* this avoids a loop in nfnetlink. */
296 return ret == -EAGAIN ? -ENOBUFS : ret;
301 /* try to delete object, fail if it is still in use. */
302 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
306 /* We want to avoid races with ctnl_timeout_put. So only when the
307 * current refcnt is 1, we decrease it to 0.
309 if (refcount_dec_if_one(&timeout->refcnt)) {
310 /* We are protected by nfnl mutex. */
311 list_del_rcu(&timeout->head);
312 nf_ct_untimeout(net, &timeout->timeout);
313 kfree_rcu(timeout, rcu_head);
320 static int cttimeout_del_timeout(struct sk_buff *skb,
321 const struct nfnl_info *info,
322 const struct nlattr * const cda[])
324 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
325 struct ctnl_timeout *cur, *tmp;
329 if (!cda[CTA_TIMEOUT_NAME]) {
330 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list,
332 ctnl_timeout_try_del(info->net, cur);
336 name = nla_data(cda[CTA_TIMEOUT_NAME]);
338 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
339 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
342 ret = ctnl_timeout_try_del(info->net, cur);
351 static int cttimeout_default_set(struct sk_buff *skb,
352 const struct nfnl_info *info,
353 const struct nlattr * const cda[])
355 const struct nf_conntrack_l4proto *l4proto;
359 if (!cda[CTA_TIMEOUT_L3PROTO] ||
360 !cda[CTA_TIMEOUT_L4PROTO] ||
361 !cda[CTA_TIMEOUT_DATA])
364 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
365 l4proto = nf_ct_l4proto_find(l4num);
367 /* This protocol is not supported, skip. */
368 if (l4proto->l4proto != l4num) {
373 ret = ctnl_timeout_parse_policy(NULL, l4proto, info->net,
374 cda[CTA_TIMEOUT_DATA]);
384 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
385 u32 seq, u32 type, int event, u16 l3num,
386 const struct nf_conntrack_l4proto *l4proto,
387 const unsigned int *timeouts)
389 struct nlmsghdr *nlh;
390 unsigned int flags = portid ? NLM_F_MULTI : 0;
391 struct nlattr *nest_parms;
394 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
395 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
400 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
401 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
402 goto nla_put_failure;
404 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
406 goto nla_put_failure;
408 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
410 goto nla_put_failure;
412 nla_nest_end(skb, nest_parms);
419 nlmsg_cancel(skb, nlh);
423 static int cttimeout_default_get(struct sk_buff *skb,
424 const struct nfnl_info *info,
425 const struct nlattr * const cda[])
427 const struct nf_conntrack_l4proto *l4proto;
428 unsigned int *timeouts = NULL;
429 struct sk_buff *skb2;
434 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
437 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
438 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
439 l4proto = nf_ct_l4proto_find(l4num);
442 if (l4proto->l4proto != l4num)
445 switch (l4proto->l4proto) {
447 timeouts = &nf_icmp_pernet(info->net)->timeout;
450 timeouts = nf_tcp_pernet(info->net)->timeouts;
453 case IPPROTO_UDPLITE:
454 timeouts = nf_udp_pernet(info->net)->timeouts;
457 #ifdef CONFIG_NF_CT_PROTO_DCCP
458 timeouts = nf_dccp_pernet(info->net)->dccp_timeout;
462 timeouts = &nf_icmpv6_pernet(info->net)->timeout;
465 #ifdef CONFIG_NF_CT_PROTO_SCTP
466 timeouts = nf_sctp_pernet(info->net)->timeouts;
470 #ifdef CONFIG_NF_CT_PROTO_GRE
471 timeouts = nf_gre_pernet(info->net)->timeouts;
475 timeouts = &nf_generic_pernet(info->net)->timeout;
478 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
485 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
491 ret = cttimeout_default_fill_info(info->net, skb2,
492 NETLINK_CB(skb).portid,
493 info->nlh->nlmsg_seq,
494 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
495 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
496 l3num, l4proto, timeouts);
502 ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
507 /* this avoids a loop in nfnetlink. */
508 return ret == -EAGAIN ? -ENOBUFS : ret;
513 static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
516 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
517 struct ctnl_timeout *timeout, *matching = NULL;
519 list_for_each_entry_rcu(timeout, &pernet->nfct_timeout_list, head) {
520 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
523 if (!try_module_get(THIS_MODULE))
526 if (!refcount_inc_not_zero(&timeout->refcnt)) {
527 module_put(THIS_MODULE);
534 return matching ? &matching->timeout : NULL;
537 static void ctnl_timeout_put(struct nf_ct_timeout *t)
539 struct ctnl_timeout *timeout =
540 container_of(t, struct ctnl_timeout, timeout);
542 if (refcount_dec_and_test(&timeout->refcnt))
543 kfree_rcu(timeout, rcu_head);
545 module_put(THIS_MODULE);
548 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
549 [IPCTNL_MSG_TIMEOUT_NEW] = {
550 .call = cttimeout_new_timeout,
551 .type = NFNL_CB_MUTEX,
552 .attr_count = CTA_TIMEOUT_MAX,
553 .policy = cttimeout_nla_policy
555 [IPCTNL_MSG_TIMEOUT_GET] = {
556 .call = cttimeout_get_timeout,
557 .type = NFNL_CB_MUTEX,
558 .attr_count = CTA_TIMEOUT_MAX,
559 .policy = cttimeout_nla_policy
561 [IPCTNL_MSG_TIMEOUT_DELETE] = {
562 .call = cttimeout_del_timeout,
563 .type = NFNL_CB_MUTEX,
564 .attr_count = CTA_TIMEOUT_MAX,
565 .policy = cttimeout_nla_policy
567 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET] = {
568 .call = cttimeout_default_set,
569 .type = NFNL_CB_MUTEX,
570 .attr_count = CTA_TIMEOUT_MAX,
571 .policy = cttimeout_nla_policy
573 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET] = {
574 .call = cttimeout_default_get,
575 .type = NFNL_CB_MUTEX,
576 .attr_count = CTA_TIMEOUT_MAX,
577 .policy = cttimeout_nla_policy
581 static const struct nfnetlink_subsystem cttimeout_subsys = {
582 .name = "conntrack_timeout",
583 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
584 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
588 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
590 static int __net_init cttimeout_net_init(struct net *net)
592 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
594 INIT_LIST_HEAD(&pernet->nfct_timeout_list);
599 static void __net_exit cttimeout_net_exit(struct net *net)
601 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
602 struct ctnl_timeout *cur, *tmp;
604 nf_ct_unconfirmed_destroy(net);
605 nf_ct_untimeout(net, NULL);
607 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list, head) {
608 list_del_rcu(&cur->head);
610 if (refcount_dec_and_test(&cur->refcnt))
611 kfree_rcu(cur, rcu_head);
615 static struct pernet_operations cttimeout_ops = {
616 .init = cttimeout_net_init,
617 .exit = cttimeout_net_exit,
618 .id = &nfct_timeout_id,
619 .size = sizeof(struct nfct_timeout_pernet),
622 static int __init cttimeout_init(void)
626 ret = register_pernet_subsys(&cttimeout_ops);
630 ret = nfnetlink_subsys_register(&cttimeout_subsys);
632 pr_err("cttimeout_init: cannot register cttimeout with "
636 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
637 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
641 unregister_pernet_subsys(&cttimeout_ops);
645 static void __exit cttimeout_exit(void)
647 nfnetlink_subsys_unregister(&cttimeout_subsys);
649 unregister_pernet_subsys(&cttimeout_ops);
650 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
651 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
655 module_init(cttimeout_init);
656 module_exit(cttimeout_exit);