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_l4proto.h>
30 #include <net/netfilter/nf_conntrack_tuple.h>
31 #include <net/netfilter/nf_conntrack_timeout.h>
33 #include <linux/netfilter/nfnetlink.h>
34 #include <linux/netfilter/nfnetlink_cttimeout.h>
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
38 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
40 static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
41 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
42 .len = CTNL_TIMEOUT_NAME_MAX - 1},
43 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
44 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
45 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
49 ctnl_timeout_parse_policy(void *timeout,
50 const struct nf_conntrack_l4proto *l4proto,
51 struct net *net, const struct nlattr *attr)
56 if (!l4proto->ctnl_timeout.nlattr_to_obj)
59 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
65 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, attr,
66 l4proto->ctnl_timeout.nla_policy, NULL);
70 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
77 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
79 const struct nlmsghdr *nlh,
80 const struct nlattr * const cda[],
81 struct netlink_ext_ack *extack)
85 const struct nf_conntrack_l4proto *l4proto;
86 struct ctnl_timeout *timeout, *matching = NULL;
90 if (!cda[CTA_TIMEOUT_NAME] ||
91 !cda[CTA_TIMEOUT_L3PROTO] ||
92 !cda[CTA_TIMEOUT_L4PROTO] ||
93 !cda[CTA_TIMEOUT_DATA])
96 name = nla_data(cda[CTA_TIMEOUT_NAME]);
97 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
98 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
100 list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
101 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
104 if (nlh->nlmsg_flags & NLM_F_EXCL)
112 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
113 /* You cannot replace one timeout policy by another of
114 * different kind, sorry.
116 if (matching->timeout.l3num != l3num ||
117 matching->timeout.l4proto->l4proto != l4num)
120 return ctnl_timeout_parse_policy(&matching->timeout.data,
121 matching->timeout.l4proto,
122 net, cda[CTA_TIMEOUT_DATA]);
128 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
130 /* This protocol is not supportted, skip. */
131 if (l4proto->l4proto != l4num) {
136 timeout = kzalloc(sizeof(struct ctnl_timeout) +
137 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
138 if (timeout == NULL) {
143 ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto, net,
144 cda[CTA_TIMEOUT_DATA]);
148 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
149 timeout->timeout.l3num = l3num;
150 timeout->timeout.l4proto = l4proto;
151 refcount_set(&timeout->refcnt, 1);
152 list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
158 nf_ct_l4proto_put(l4proto);
163 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
164 int event, struct ctnl_timeout *timeout)
166 struct nlmsghdr *nlh;
167 struct nfgenmsg *nfmsg;
168 unsigned int flags = portid ? NLM_F_MULTI : 0;
169 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
171 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
172 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
176 nfmsg = nlmsg_data(nlh);
177 nfmsg->nfgen_family = AF_UNSPEC;
178 nfmsg->version = NFNETLINK_V0;
181 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
182 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
183 htons(timeout->timeout.l3num)) ||
184 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, 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,
199 &timeout->timeout.data);
201 goto nla_put_failure;
203 nla_nest_end(skb, nest_parms);
211 nlmsg_cancel(skb, nlh);
216 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
218 struct net *net = sock_net(skb->sk);
219 struct ctnl_timeout *cur, *last;
224 last = (struct ctnl_timeout *)cb->args[1];
229 list_for_each_entry_rcu(cur, &net->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 net *net, struct sock *ctnl,
252 const struct nlmsghdr *nlh,
253 const struct nlattr * const cda[],
254 struct netlink_ext_ack *extack)
258 struct ctnl_timeout *cur;
260 if (nlh->nlmsg_flags & NLM_F_DUMP) {
261 struct netlink_dump_control c = {
262 .dump = ctnl_timeout_dump,
264 return netlink_dump_start(ctnl, skb, nlh, &c);
267 if (!cda[CTA_TIMEOUT_NAME])
269 name = nla_data(cda[CTA_TIMEOUT_NAME]);
271 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
272 struct sk_buff *skb2;
274 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
277 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
283 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
285 NFNL_MSG_TYPE(nlh->nlmsg_type),
286 IPCTNL_MSG_TIMEOUT_NEW, cur);
291 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
296 /* this avoids a loop in nfnetlink. */
297 return ret == -EAGAIN ? -ENOBUFS : ret;
302 /* try to delete object, fail if it is still in use. */
303 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
307 /* We want to avoid races with ctnl_timeout_put. So only when the
308 * current refcnt is 1, we decrease it to 0.
310 if (refcount_dec_if_one(&timeout->refcnt)) {
311 /* We are protected by nfnl mutex. */
312 list_del_rcu(&timeout->head);
313 nf_ct_l4proto_put(timeout->timeout.l4proto);
314 nf_ct_untimeout(net, &timeout->timeout);
315 kfree_rcu(timeout, rcu_head);
322 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
324 const struct nlmsghdr *nlh,
325 const struct nlattr * const cda[],
326 struct netlink_ext_ack *extack)
328 struct ctnl_timeout *cur, *tmp;
332 if (!cda[CTA_TIMEOUT_NAME]) {
333 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
335 ctnl_timeout_try_del(net, cur);
339 name = nla_data(cda[CTA_TIMEOUT_NAME]);
341 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
342 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
345 ret = ctnl_timeout_try_del(net, cur);
354 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
356 const struct nlmsghdr *nlh,
357 const struct nlattr * const cda[],
358 struct netlink_ext_ack *extack)
360 const struct nf_conntrack_l4proto *l4proto;
365 if (!cda[CTA_TIMEOUT_L3PROTO] ||
366 !cda[CTA_TIMEOUT_L4PROTO] ||
367 !cda[CTA_TIMEOUT_DATA])
370 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
371 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
372 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
374 /* This protocol is not supported, skip. */
375 if (l4proto->l4proto != l4num) {
380 ret = ctnl_timeout_parse_policy(NULL, l4proto, net,
381 cda[CTA_TIMEOUT_DATA]);
385 nf_ct_l4proto_put(l4proto);
388 nf_ct_l4proto_put(l4proto);
393 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
394 u32 seq, u32 type, int event,
395 const struct nf_conntrack_l4proto *l4proto)
397 struct nlmsghdr *nlh;
398 struct nfgenmsg *nfmsg;
399 unsigned int flags = portid ? NLM_F_MULTI : 0;
401 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
402 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
406 nfmsg = nlmsg_data(nlh);
407 nfmsg->nfgen_family = AF_UNSPEC;
408 nfmsg->version = NFNETLINK_V0;
411 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
412 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
413 goto nla_put_failure;
415 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
416 struct nlattr *nest_parms;
419 nest_parms = nla_nest_start(skb,
420 CTA_TIMEOUT_DATA | NLA_F_NESTED);
422 goto nla_put_failure;
424 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, NULL);
426 goto nla_put_failure;
428 nla_nest_end(skb, nest_parms);
436 nlmsg_cancel(skb, nlh);
440 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
442 const struct nlmsghdr *nlh,
443 const struct nlattr * const cda[],
444 struct netlink_ext_ack *extack)
446 const struct nf_conntrack_l4proto *l4proto;
447 struct sk_buff *skb2;
452 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
455 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
456 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
457 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
459 /* This protocol is not supported, skip. */
460 if (l4proto->l4proto != l4num) {
465 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
471 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
473 NFNL_MSG_TYPE(nlh->nlmsg_type),
474 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
481 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
485 /* this avoids a loop in nfnetlink. */
486 return ret == -EAGAIN ? -ENOBUFS : ret;
488 nf_ct_l4proto_put(l4proto);
492 static struct ctnl_timeout *
493 ctnl_timeout_find_get(struct net *net, const char *name)
495 struct ctnl_timeout *timeout, *matching = NULL;
497 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
498 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
501 if (!try_module_get(THIS_MODULE))
504 if (!refcount_inc_not_zero(&timeout->refcnt)) {
505 module_put(THIS_MODULE);
515 static void ctnl_timeout_put(struct nf_ct_timeout *t)
517 struct ctnl_timeout *timeout =
518 container_of(t, struct ctnl_timeout, timeout);
520 if (refcount_dec_and_test(&timeout->refcnt))
521 kfree_rcu(timeout, rcu_head);
523 module_put(THIS_MODULE);
526 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
527 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
528 .attr_count = CTA_TIMEOUT_MAX,
529 .policy = cttimeout_nla_policy },
530 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
531 .attr_count = CTA_TIMEOUT_MAX,
532 .policy = cttimeout_nla_policy },
533 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
534 .attr_count = CTA_TIMEOUT_MAX,
535 .policy = cttimeout_nla_policy },
536 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
537 .attr_count = CTA_TIMEOUT_MAX,
538 .policy = cttimeout_nla_policy },
539 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
540 .attr_count = CTA_TIMEOUT_MAX,
541 .policy = cttimeout_nla_policy },
544 static const struct nfnetlink_subsystem cttimeout_subsys = {
545 .name = "conntrack_timeout",
546 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
547 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
551 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
553 static int __net_init cttimeout_net_init(struct net *net)
555 INIT_LIST_HEAD(&net->nfct_timeout_list);
560 static void __net_exit cttimeout_net_exit(struct net *net)
562 struct ctnl_timeout *cur, *tmp;
564 nf_ct_unconfirmed_destroy(net);
565 nf_ct_untimeout(net, NULL);
567 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
568 list_del_rcu(&cur->head);
569 nf_ct_l4proto_put(cur->timeout.l4proto);
571 if (refcount_dec_and_test(&cur->refcnt))
572 kfree_rcu(cur, rcu_head);
576 static struct pernet_operations cttimeout_ops = {
577 .init = cttimeout_net_init,
578 .exit = cttimeout_net_exit,
581 static int __init cttimeout_init(void)
585 ret = register_pernet_subsys(&cttimeout_ops);
589 ret = nfnetlink_subsys_register(&cttimeout_subsys);
591 pr_err("cttimeout_init: cannot register cttimeout with "
595 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
596 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
600 unregister_pernet_subsys(&cttimeout_ops);
604 static void __exit cttimeout_exit(void)
606 nfnetlink_subsys_unregister(&cttimeout_subsys);
608 unregister_pernet_subsys(&cttimeout_ops);
609 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
610 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
614 module_init(cttimeout_init);
615 module_exit(cttimeout_exit);