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 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
62 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, attr,
63 l4proto->ctnl_timeout.nla_policy, NULL);
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_get(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);
155 nf_ct_l4proto_put(l4proto);
160 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
161 int event, struct ctnl_timeout *timeout)
163 struct nlmsghdr *nlh;
164 struct nfgenmsg *nfmsg;
165 unsigned int flags = portid ? NLM_F_MULTI : 0;
166 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
167 struct nlattr *nest_parms;
170 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
171 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
175 nfmsg = nlmsg_data(nlh);
176 nfmsg->nfgen_family = AF_UNSPEC;
177 nfmsg->version = NFNETLINK_V0;
180 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
181 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
182 htons(timeout->timeout.l3num)) ||
183 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
184 nla_put_be32(skb, CTA_TIMEOUT_USE,
185 htonl(refcount_read(&timeout->refcnt))))
186 goto nla_put_failure;
188 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA | NLA_F_NESTED);
190 goto nla_put_failure;
192 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
194 goto nla_put_failure;
196 nla_nest_end(skb, nest_parms);
203 nlmsg_cancel(skb, nlh);
208 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
210 struct net *net = sock_net(skb->sk);
211 struct ctnl_timeout *cur, *last;
216 last = (struct ctnl_timeout *)cb->args[1];
221 list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
228 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
230 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
231 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
232 cb->args[1] = (unsigned long)cur;
242 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
244 const struct nlmsghdr *nlh,
245 const struct nlattr * const cda[],
246 struct netlink_ext_ack *extack)
250 struct ctnl_timeout *cur;
252 if (nlh->nlmsg_flags & NLM_F_DUMP) {
253 struct netlink_dump_control c = {
254 .dump = ctnl_timeout_dump,
256 return netlink_dump_start(ctnl, skb, nlh, &c);
259 if (!cda[CTA_TIMEOUT_NAME])
261 name = nla_data(cda[CTA_TIMEOUT_NAME]);
263 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
264 struct sk_buff *skb2;
266 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
269 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
275 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
277 NFNL_MSG_TYPE(nlh->nlmsg_type),
278 IPCTNL_MSG_TIMEOUT_NEW, cur);
283 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
288 /* this avoids a loop in nfnetlink. */
289 return ret == -EAGAIN ? -ENOBUFS : ret;
294 /* try to delete object, fail if it is still in use. */
295 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
299 /* We want to avoid races with ctnl_timeout_put. So only when the
300 * current refcnt is 1, we decrease it to 0.
302 if (refcount_dec_if_one(&timeout->refcnt)) {
303 /* We are protected by nfnl mutex. */
304 list_del_rcu(&timeout->head);
305 nf_ct_l4proto_put(timeout->timeout.l4proto);
306 nf_ct_untimeout(net, &timeout->timeout);
307 kfree_rcu(timeout, rcu_head);
314 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
316 const struct nlmsghdr *nlh,
317 const struct nlattr * const cda[],
318 struct netlink_ext_ack *extack)
320 struct ctnl_timeout *cur, *tmp;
324 if (!cda[CTA_TIMEOUT_NAME]) {
325 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
327 ctnl_timeout_try_del(net, cur);
331 name = nla_data(cda[CTA_TIMEOUT_NAME]);
333 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
334 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
337 ret = ctnl_timeout_try_del(net, cur);
346 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
348 const struct nlmsghdr *nlh,
349 const struct nlattr * const cda[],
350 struct netlink_ext_ack *extack)
352 const struct nf_conntrack_l4proto *l4proto;
356 if (!cda[CTA_TIMEOUT_L3PROTO] ||
357 !cda[CTA_TIMEOUT_L4PROTO] ||
358 !cda[CTA_TIMEOUT_DATA])
361 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
362 l4proto = nf_ct_l4proto_find_get(l4num);
364 /* This protocol is not supported, skip. */
365 if (l4proto->l4proto != l4num) {
370 ret = ctnl_timeout_parse_policy(NULL, l4proto, net,
371 cda[CTA_TIMEOUT_DATA]);
375 nf_ct_l4proto_put(l4proto);
378 nf_ct_l4proto_put(l4proto);
383 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
384 u32 seq, u32 type, int event, u16 l3num,
385 const struct nf_conntrack_l4proto *l4proto)
387 struct nlmsghdr *nlh;
388 struct nfgenmsg *nfmsg;
389 unsigned int flags = portid ? NLM_F_MULTI : 0;
390 struct nlattr *nest_parms;
393 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
394 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
398 nfmsg = nlmsg_data(nlh);
399 nfmsg->nfgen_family = AF_UNSPEC;
400 nfmsg->version = NFNETLINK_V0;
403 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
404 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
405 goto nla_put_failure;
407 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA | NLA_F_NESTED);
409 goto nla_put_failure;
411 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, NULL);
413 goto nla_put_failure;
415 nla_nest_end(skb, nest_parms);
422 nlmsg_cancel(skb, nlh);
426 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
428 const struct nlmsghdr *nlh,
429 const struct nlattr * const cda[],
430 struct netlink_ext_ack *extack)
432 const struct nf_conntrack_l4proto *l4proto;
433 struct sk_buff *skb2;
438 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
441 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
442 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
443 l4proto = nf_ct_l4proto_find_get(l4num);
445 /* This protocol is not supported, skip. */
446 if (l4proto->l4proto != l4num) {
451 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
457 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
459 NFNL_MSG_TYPE(nlh->nlmsg_type),
460 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
468 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
472 /* this avoids a loop in nfnetlink. */
473 return ret == -EAGAIN ? -ENOBUFS : ret;
475 nf_ct_l4proto_put(l4proto);
479 static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
482 struct ctnl_timeout *timeout, *matching = NULL;
484 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
485 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
488 if (!try_module_get(THIS_MODULE))
491 if (!refcount_inc_not_zero(&timeout->refcnt)) {
492 module_put(THIS_MODULE);
499 return matching ? &matching->timeout : NULL;
502 static void ctnl_timeout_put(struct nf_ct_timeout *t)
504 struct ctnl_timeout *timeout =
505 container_of(t, struct ctnl_timeout, timeout);
507 if (refcount_dec_and_test(&timeout->refcnt))
508 kfree_rcu(timeout, rcu_head);
510 module_put(THIS_MODULE);
513 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
514 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
515 .attr_count = CTA_TIMEOUT_MAX,
516 .policy = cttimeout_nla_policy },
517 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
518 .attr_count = CTA_TIMEOUT_MAX,
519 .policy = cttimeout_nla_policy },
520 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
521 .attr_count = CTA_TIMEOUT_MAX,
522 .policy = cttimeout_nla_policy },
523 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
524 .attr_count = CTA_TIMEOUT_MAX,
525 .policy = cttimeout_nla_policy },
526 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
527 .attr_count = CTA_TIMEOUT_MAX,
528 .policy = cttimeout_nla_policy },
531 static const struct nfnetlink_subsystem cttimeout_subsys = {
532 .name = "conntrack_timeout",
533 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
534 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
538 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
540 static int __net_init cttimeout_net_init(struct net *net)
542 INIT_LIST_HEAD(&net->nfct_timeout_list);
547 static void __net_exit cttimeout_net_exit(struct net *net)
549 struct ctnl_timeout *cur, *tmp;
551 nf_ct_unconfirmed_destroy(net);
552 nf_ct_untimeout(net, NULL);
554 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
555 list_del_rcu(&cur->head);
556 nf_ct_l4proto_put(cur->timeout.l4proto);
558 if (refcount_dec_and_test(&cur->refcnt))
559 kfree_rcu(cur, rcu_head);
563 static struct pernet_operations cttimeout_ops = {
564 .init = cttimeout_net_init,
565 .exit = cttimeout_net_exit,
568 static int __init cttimeout_init(void)
572 ret = register_pernet_subsys(&cttimeout_ops);
576 ret = nfnetlink_subsys_register(&cttimeout_subsys);
578 pr_err("cttimeout_init: cannot register cttimeout with "
582 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
583 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
587 unregister_pernet_subsys(&cttimeout_ops);
591 static void __exit cttimeout_exit(void)
593 nfnetlink_subsys_unregister(&cttimeout_subsys);
595 unregister_pernet_subsys(&cttimeout_ops);
596 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
597 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
601 module_init(cttimeout_init);
602 module_exit(cttimeout_exit);