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>
24 #include <net/netfilter/nf_conntrack.h>
25 #include <net/netfilter/nf_conntrack_core.h>
26 #include <net/netfilter/nf_conntrack_l4proto.h>
27 #include <net/netfilter/nf_conntrack_tuple.h>
28 #include <net/netfilter/nf_conntrack_timeout.h>
30 #include <linux/netfilter/nfnetlink.h>
31 #include <linux/netfilter/nfnetlink_cttimeout.h>
33 MODULE_LICENSE("GPL");
34 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
35 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
37 static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
38 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
39 .len = CTNL_TIMEOUT_NAME_MAX - 1},
40 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
41 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
42 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
46 ctnl_timeout_parse_policy(void *timeout,
47 const struct nf_conntrack_l4proto *l4proto,
48 struct net *net, const struct nlattr *attr)
53 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
59 ret = nla_parse_nested_deprecated(tb,
60 l4proto->ctnl_timeout.nlattr_max,
62 l4proto->ctnl_timeout.nla_policy,
67 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
74 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
76 const struct nlmsghdr *nlh,
77 const struct nlattr * const cda[],
78 struct netlink_ext_ack *extack)
82 const struct nf_conntrack_l4proto *l4proto;
83 struct ctnl_timeout *timeout, *matching = NULL;
87 if (!cda[CTA_TIMEOUT_NAME] ||
88 !cda[CTA_TIMEOUT_L3PROTO] ||
89 !cda[CTA_TIMEOUT_L4PROTO] ||
90 !cda[CTA_TIMEOUT_DATA])
93 name = nla_data(cda[CTA_TIMEOUT_NAME]);
94 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
95 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
97 list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
98 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
101 if (nlh->nlmsg_flags & NLM_F_EXCL)
109 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
110 /* You cannot replace one timeout policy by another of
111 * different kind, sorry.
113 if (matching->timeout.l3num != l3num ||
114 matching->timeout.l4proto->l4proto != l4num)
117 return ctnl_timeout_parse_policy(&matching->timeout.data,
118 matching->timeout.l4proto,
119 net, cda[CTA_TIMEOUT_DATA]);
125 l4proto = nf_ct_l4proto_find(l4num);
127 /* This protocol is not supportted, skip. */
128 if (l4proto->l4proto != l4num) {
133 timeout = kzalloc(sizeof(struct ctnl_timeout) +
134 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
135 if (timeout == NULL) {
140 ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto, net,
141 cda[CTA_TIMEOUT_DATA]);
145 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
146 timeout->timeout.l3num = l3num;
147 timeout->timeout.l4proto = l4proto;
148 refcount_set(&timeout->refcnt, 1);
149 list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
159 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
160 int event, struct ctnl_timeout *timeout)
162 struct nlmsghdr *nlh;
163 struct nfgenmsg *nfmsg;
164 unsigned int flags = portid ? NLM_F_MULTI : 0;
165 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
166 struct nlattr *nest_parms;
169 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
170 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
174 nfmsg = nlmsg_data(nlh);
175 nfmsg->nfgen_family = AF_UNSPEC;
176 nfmsg->version = NFNETLINK_V0;
179 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
180 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
181 htons(timeout->timeout.l3num)) ||
182 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
183 nla_put_be32(skb, CTA_TIMEOUT_USE,
184 htonl(refcount_read(&timeout->refcnt))))
185 goto nla_put_failure;
187 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
189 goto nla_put_failure;
191 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
193 goto nla_put_failure;
195 nla_nest_end(skb, nest_parms);
202 nlmsg_cancel(skb, nlh);
207 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
209 struct net *net = sock_net(skb->sk);
210 struct ctnl_timeout *cur, *last;
215 last = (struct ctnl_timeout *)cb->args[1];
220 list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
227 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
229 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
230 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
231 cb->args[1] = (unsigned long)cur;
241 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
243 const struct nlmsghdr *nlh,
244 const struct nlattr * const cda[],
245 struct netlink_ext_ack *extack)
249 struct ctnl_timeout *cur;
251 if (nlh->nlmsg_flags & NLM_F_DUMP) {
252 struct netlink_dump_control c = {
253 .dump = ctnl_timeout_dump,
255 return netlink_dump_start(ctnl, skb, nlh, &c);
258 if (!cda[CTA_TIMEOUT_NAME])
260 name = nla_data(cda[CTA_TIMEOUT_NAME]);
262 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
263 struct sk_buff *skb2;
265 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
268 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
274 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
276 NFNL_MSG_TYPE(nlh->nlmsg_type),
277 IPCTNL_MSG_TIMEOUT_NEW, cur);
282 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
287 /* this avoids a loop in nfnetlink. */
288 return ret == -EAGAIN ? -ENOBUFS : ret;
293 /* try to delete object, fail if it is still in use. */
294 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
298 /* We want to avoid races with ctnl_timeout_put. So only when the
299 * current refcnt is 1, we decrease it to 0.
301 if (refcount_dec_if_one(&timeout->refcnt)) {
302 /* We are protected by nfnl mutex. */
303 list_del_rcu(&timeout->head);
304 nf_ct_untimeout(net, &timeout->timeout);
305 kfree_rcu(timeout, rcu_head);
312 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
314 const struct nlmsghdr *nlh,
315 const struct nlattr * const cda[],
316 struct netlink_ext_ack *extack)
318 struct ctnl_timeout *cur, *tmp;
322 if (!cda[CTA_TIMEOUT_NAME]) {
323 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
325 ctnl_timeout_try_del(net, cur);
329 name = nla_data(cda[CTA_TIMEOUT_NAME]);
331 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
332 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
335 ret = ctnl_timeout_try_del(net, cur);
344 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
346 const struct nlmsghdr *nlh,
347 const struct nlattr * const cda[],
348 struct netlink_ext_ack *extack)
350 const struct nf_conntrack_l4proto *l4proto;
354 if (!cda[CTA_TIMEOUT_L3PROTO] ||
355 !cda[CTA_TIMEOUT_L4PROTO] ||
356 !cda[CTA_TIMEOUT_DATA])
359 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
360 l4proto = nf_ct_l4proto_find(l4num);
362 /* This protocol is not supported, skip. */
363 if (l4proto->l4proto != l4num) {
368 ret = ctnl_timeout_parse_policy(NULL, l4proto, net,
369 cda[CTA_TIMEOUT_DATA]);
379 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
380 u32 seq, u32 type, int event, u16 l3num,
381 const struct nf_conntrack_l4proto *l4proto,
382 const unsigned int *timeouts)
384 struct nlmsghdr *nlh;
385 struct nfgenmsg *nfmsg;
386 unsigned int flags = portid ? NLM_F_MULTI : 0;
387 struct nlattr *nest_parms;
390 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
391 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
395 nfmsg = nlmsg_data(nlh);
396 nfmsg->nfgen_family = AF_UNSPEC;
397 nfmsg->version = NFNETLINK_V0;
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 net *net, struct sock *ctnl,
425 const struct nlmsghdr *nlh,
426 const struct nlattr * const cda[],
427 struct netlink_ext_ack *extack)
429 const struct nf_conntrack_l4proto *l4proto;
430 unsigned int *timeouts = NULL;
431 struct sk_buff *skb2;
436 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
439 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
440 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
441 l4proto = nf_ct_l4proto_find(l4num);
444 if (l4proto->l4proto != l4num)
447 switch (l4proto->l4proto) {
449 timeouts = &nf_icmp_pernet(net)->timeout;
452 timeouts = nf_tcp_pernet(net)->timeouts;
455 case IPPROTO_UDPLITE:
456 timeouts = nf_udp_pernet(net)->timeouts;
459 #ifdef CONFIG_NF_CT_PROTO_DCCP
460 timeouts = nf_dccp_pernet(net)->dccp_timeout;
464 timeouts = &nf_icmpv6_pernet(net)->timeout;
467 #ifdef CONFIG_NF_CT_PROTO_SCTP
468 timeouts = nf_sctp_pernet(net)->timeouts;
472 #ifdef CONFIG_NF_CT_PROTO_GRE
473 timeouts = nf_gre_pernet(net)->timeouts;
477 timeouts = &nf_generic_pernet(net)->timeout;
480 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
487 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
493 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
495 NFNL_MSG_TYPE(nlh->nlmsg_type),
496 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
497 l3num, l4proto, timeouts);
503 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
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 ctnl_timeout *timeout, *matching = NULL;
518 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
519 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
522 if (!try_module_get(THIS_MODULE))
525 if (!refcount_inc_not_zero(&timeout->refcnt)) {
526 module_put(THIS_MODULE);
533 return matching ? &matching->timeout : NULL;
536 static void ctnl_timeout_put(struct nf_ct_timeout *t)
538 struct ctnl_timeout *timeout =
539 container_of(t, struct ctnl_timeout, timeout);
541 if (refcount_dec_and_test(&timeout->refcnt))
542 kfree_rcu(timeout, rcu_head);
544 module_put(THIS_MODULE);
547 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
548 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
549 .attr_count = CTA_TIMEOUT_MAX,
550 .policy = cttimeout_nla_policy },
551 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
552 .attr_count = CTA_TIMEOUT_MAX,
553 .policy = cttimeout_nla_policy },
554 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
555 .attr_count = CTA_TIMEOUT_MAX,
556 .policy = cttimeout_nla_policy },
557 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
558 .attr_count = CTA_TIMEOUT_MAX,
559 .policy = cttimeout_nla_policy },
560 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
561 .attr_count = CTA_TIMEOUT_MAX,
562 .policy = cttimeout_nla_policy },
565 static const struct nfnetlink_subsystem cttimeout_subsys = {
566 .name = "conntrack_timeout",
567 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
568 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
572 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
574 static int __net_init cttimeout_net_init(struct net *net)
576 INIT_LIST_HEAD(&net->nfct_timeout_list);
581 static void __net_exit cttimeout_net_exit(struct net *net)
583 struct ctnl_timeout *cur, *tmp;
585 nf_ct_unconfirmed_destroy(net);
586 nf_ct_untimeout(net, NULL);
588 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
589 list_del_rcu(&cur->head);
591 if (refcount_dec_and_test(&cur->refcnt))
592 kfree_rcu(cur, rcu_head);
596 static struct pernet_operations cttimeout_ops = {
597 .init = cttimeout_net_init,
598 .exit = cttimeout_net_exit,
601 static int __init cttimeout_init(void)
605 ret = register_pernet_subsys(&cttimeout_ops);
609 ret = nfnetlink_subsys_register(&cttimeout_subsys);
611 pr_err("cttimeout_init: cannot register cttimeout with "
615 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
616 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
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 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
630 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
634 module_init(cttimeout_init);
635 module_exit(cttimeout_exit);