1 /* L3/L4 protocol support for nf_conntrack. */
3 /* (C) 1999-2001 Paul `Rusty' Russell
4 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
5 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
6 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/types.h>
14 #include <linux/netfilter.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/mutex.h>
18 #include <linux/vmalloc.h>
19 #include <linux/stddef.h>
20 #include <linux/err.h>
21 #include <linux/percpu.h>
22 #include <linux/notifier.h>
23 #include <linux/kernel.h>
24 #include <linux/netdevice.h>
26 #include <net/netfilter/nf_conntrack.h>
27 #include <net/netfilter/nf_conntrack_l3proto.h>
28 #include <net/netfilter/nf_conntrack_l4proto.h>
29 #include <net/netfilter/nf_conntrack_core.h>
30 #include <net/netfilter/nf_log.h>
32 static struct nf_conntrack_l4proto __rcu **nf_ct_protos[NFPROTO_NUMPROTO] __read_mostly;
33 struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO] __read_mostly;
34 EXPORT_SYMBOL_GPL(nf_ct_l3protos);
36 static DEFINE_MUTEX(nf_ct_proto_mutex);
40 nf_ct_register_sysctl(struct net *net,
41 struct ctl_table_header **header,
43 struct ctl_table *table)
45 if (*header == NULL) {
46 *header = register_net_sysctl(net, path, table);
55 nf_ct_unregister_sysctl(struct ctl_table_header **header,
56 struct ctl_table **table,
62 unregister_net_sysctl_table(*header);
69 void nf_l4proto_log_invalid(const struct sk_buff *skb,
77 if (net->ct.sysctl_log_invalid != protonum ||
78 net->ct.sysctl_log_invalid != IPPROTO_RAW)
85 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
86 "nf_ct_proto_%d: %pV ", protonum, &vaf);
89 EXPORT_SYMBOL_GPL(nf_l4proto_log_invalid);
92 void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
93 const struct nf_conn *ct,
101 if (likely(net->ct.sysctl_log_invalid == 0))
108 nf_l4proto_log_invalid(skb, net, nf_ct_l3num(ct),
109 nf_ct_protonum(ct), "%pV", &vaf);
112 EXPORT_SYMBOL_GPL(nf_ct_l4proto_log_invalid);
115 const struct nf_conntrack_l4proto *
116 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
118 if (unlikely(l3proto >= NFPROTO_NUMPROTO || nf_ct_protos[l3proto] == NULL))
119 return &nf_conntrack_l4proto_generic;
121 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
123 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
125 /* this is guaranteed to always return a valid protocol helper, since
126 * it falls back to generic_protocol */
127 const struct nf_conntrack_l3proto *
128 nf_ct_l3proto_find_get(u_int16_t l3proto)
130 struct nf_conntrack_l3proto *p;
133 p = __nf_ct_l3proto_find(l3proto);
134 if (!try_module_get(p->me))
135 p = &nf_conntrack_l3proto_generic;
140 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
143 nf_ct_l3proto_try_module_get(unsigned short l3proto)
145 const struct nf_conntrack_l3proto *p;
148 retry: p = nf_ct_l3proto_find_get(l3proto);
149 if (p == &nf_conntrack_l3proto_generic) {
150 ret = request_module("nf_conntrack-%d", l3proto);
159 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
161 void nf_ct_l3proto_module_put(unsigned short l3proto)
163 struct nf_conntrack_l3proto *p;
165 /* rcu_read_lock not necessary since the caller holds a reference, but
166 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
169 p = __nf_ct_l3proto_find(l3proto);
173 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
175 static int nf_ct_netns_do_get(struct net *net, u8 nfproto)
177 const struct nf_conntrack_l3proto *l3proto;
182 ret = nf_ct_l3proto_try_module_get(nfproto);
186 /* we already have a reference, can't fail */
188 l3proto = __nf_ct_l3proto_find(nfproto);
191 if (!l3proto->net_ns_get)
194 ret = l3proto->net_ns_get(net);
196 nf_ct_l3proto_module_put(nfproto);
201 int nf_ct_netns_get(struct net *net, u8 nfproto)
205 if (nfproto == NFPROTO_INET) {
206 err = nf_ct_netns_do_get(net, NFPROTO_IPV4);
209 err = nf_ct_netns_do_get(net, NFPROTO_IPV6);
213 err = nf_ct_netns_do_get(net, nfproto);
220 nf_ct_netns_put(net, NFPROTO_IPV4);
224 EXPORT_SYMBOL_GPL(nf_ct_netns_get);
226 static void nf_ct_netns_do_put(struct net *net, u8 nfproto)
228 const struct nf_conntrack_l3proto *l3proto;
232 /* same as nf_conntrack_netns_get(), reference assumed */
234 l3proto = __nf_ct_l3proto_find(nfproto);
237 if (WARN_ON(!l3proto))
240 if (l3proto->net_ns_put)
241 l3proto->net_ns_put(net);
243 nf_ct_l3proto_module_put(nfproto);
246 void nf_ct_netns_put(struct net *net, uint8_t nfproto)
248 if (nfproto == NFPROTO_INET) {
249 nf_ct_netns_do_put(net, NFPROTO_IPV4);
250 nf_ct_netns_do_put(net, NFPROTO_IPV6);
252 nf_ct_netns_do_put(net, nfproto);
254 EXPORT_SYMBOL_GPL(nf_ct_netns_put);
256 const struct nf_conntrack_l4proto *
257 nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
259 const struct nf_conntrack_l4proto *p;
262 p = __nf_ct_l4proto_find(l3num, l4num);
263 if (!try_module_get(p->me))
264 p = &nf_conntrack_l4proto_generic;
269 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
271 void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p)
275 EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
277 static int kill_l3proto(struct nf_conn *i, void *data)
279 return nf_ct_l3num(i) == ((const struct nf_conntrack_l3proto *)data)->l3proto;
282 static int kill_l4proto(struct nf_conn *i, void *data)
284 const struct nf_conntrack_l4proto *l4proto;
286 return nf_ct_protonum(i) == l4proto->l4proto &&
287 nf_ct_l3num(i) == l4proto->l3proto;
290 int nf_ct_l3proto_register(const struct nf_conntrack_l3proto *proto)
293 struct nf_conntrack_l3proto *old;
295 if (proto->l3proto >= NFPROTO_NUMPROTO)
297 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
298 if (proto->tuple_to_nlattr && proto->nla_size == 0)
301 mutex_lock(&nf_ct_proto_mutex);
302 old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
303 lockdep_is_held(&nf_ct_proto_mutex));
304 if (old != &nf_conntrack_l3proto_generic) {
309 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
312 mutex_unlock(&nf_ct_proto_mutex);
316 EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
318 void nf_ct_l3proto_unregister(const struct nf_conntrack_l3proto *proto)
320 BUG_ON(proto->l3proto >= NFPROTO_NUMPROTO);
322 mutex_lock(&nf_ct_proto_mutex);
323 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
324 lockdep_is_held(&nf_ct_proto_mutex)
326 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
327 &nf_conntrack_l3proto_generic);
328 mutex_unlock(&nf_ct_proto_mutex);
331 /* Remove all contrack entries for this protocol */
332 nf_ct_iterate_destroy(kill_l3proto, (void*)proto);
334 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
336 static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
337 const struct nf_conntrack_l4proto *l4proto)
339 if (l4proto->get_net_proto) {
340 /* statically built-in protocols use static per-net */
341 return l4proto->get_net_proto(net);
342 } else if (l4proto->net_id) {
343 /* ... and loadable protocols use dynamic per-net */
344 return net_generic(net, *l4proto->net_id);
350 int nf_ct_l4proto_register_sysctl(struct net *net,
351 struct nf_proto_net *pn,
352 const struct nf_conntrack_l4proto *l4proto)
357 if (pn->ctl_table != NULL) {
358 err = nf_ct_register_sysctl(net,
359 &pn->ctl_table_header,
364 kfree(pn->ctl_table);
365 pn->ctl_table = NULL;
369 #endif /* CONFIG_SYSCTL */
374 void nf_ct_l4proto_unregister_sysctl(struct net *net,
375 struct nf_proto_net *pn,
376 const struct nf_conntrack_l4proto *l4proto)
379 if (pn->ctl_table_header != NULL)
380 nf_ct_unregister_sysctl(&pn->ctl_table_header,
383 #endif /* CONFIG_SYSCTL */
386 /* FIXME: Allow NULL functions and sub in pointers to generic for
388 int nf_ct_l4proto_register_one(const struct nf_conntrack_l4proto *l4proto)
392 if (l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos))
395 if ((l4proto->to_nlattr && l4proto->nlattr_size == 0) ||
396 (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
399 mutex_lock(&nf_ct_proto_mutex);
400 if (!nf_ct_protos[l4proto->l3proto]) {
401 /* l3proto may be loaded latter. */
402 struct nf_conntrack_l4proto __rcu **proto_array;
405 proto_array = kmalloc(MAX_NF_CT_PROTO *
406 sizeof(struct nf_conntrack_l4proto *),
408 if (proto_array == NULL) {
413 for (i = 0; i < MAX_NF_CT_PROTO; i++)
414 RCU_INIT_POINTER(proto_array[i],
415 &nf_conntrack_l4proto_generic);
417 /* Before making proto_array visible to lockless readers,
418 * we must make sure its content is committed to memory.
422 nf_ct_protos[l4proto->l3proto] = proto_array;
423 } else if (rcu_dereference_protected(
424 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
425 lockdep_is_held(&nf_ct_proto_mutex)
426 ) != &nf_conntrack_l4proto_generic) {
431 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
434 mutex_unlock(&nf_ct_proto_mutex);
437 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);
439 int nf_ct_l4proto_pernet_register_one(struct net *net,
440 const struct nf_conntrack_l4proto *l4proto)
443 struct nf_proto_net *pn = NULL;
445 if (l4proto->init_net) {
446 ret = l4proto->init_net(net, l4proto->l3proto);
451 pn = nf_ct_l4proto_net(net, l4proto);
455 ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
463 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);
465 static void __nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
468 BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));
470 BUG_ON(rcu_dereference_protected(
471 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
472 lockdep_is_held(&nf_ct_proto_mutex)
474 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
475 &nf_conntrack_l4proto_generic);
478 void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
480 mutex_lock(&nf_ct_proto_mutex);
481 __nf_ct_l4proto_unregister_one(l4proto);
482 mutex_unlock(&nf_ct_proto_mutex);
486 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);
488 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
489 const struct nf_conntrack_l4proto *l4proto)
491 struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);
497 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
499 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister_one);
501 int nf_ct_l4proto_register(const struct nf_conntrack_l4proto * const l4proto[],
502 unsigned int num_proto)
504 int ret = -EINVAL, ver;
507 for (i = 0; i < num_proto; i++) {
508 ret = nf_ct_l4proto_register_one(l4proto[i]);
512 if (i != num_proto) {
513 ver = l4proto[i]->l3proto == PF_INET6 ? 6 : 4;
514 pr_err("nf_conntrack_ipv%d: can't register l4 %d proto.\n",
515 ver, l4proto[i]->l4proto);
516 nf_ct_l4proto_unregister(l4proto, i);
520 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
522 int nf_ct_l4proto_pernet_register(struct net *net,
523 const struct nf_conntrack_l4proto *const l4proto[],
524 unsigned int num_proto)
529 for (i = 0; i < num_proto; i++) {
530 ret = nf_ct_l4proto_pernet_register_one(net, l4proto[i]);
534 if (i != num_proto) {
535 pr_err("nf_conntrack_proto_%d %d: pernet registration failed\n",
537 l4proto[i]->l3proto == PF_INET6 ? 6 : 4);
538 nf_ct_l4proto_pernet_unregister(net, l4proto, i);
542 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
544 void nf_ct_l4proto_unregister(const struct nf_conntrack_l4proto * const l4proto[],
545 unsigned int num_proto)
547 mutex_lock(&nf_ct_proto_mutex);
548 while (num_proto-- != 0)
549 __nf_ct_l4proto_unregister_one(l4proto[num_proto]);
550 mutex_unlock(&nf_ct_proto_mutex);
553 /* Remove all contrack entries for this protocol */
554 nf_ct_iterate_destroy(kill_l4proto, (void *)l4proto);
556 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
558 void nf_ct_l4proto_pernet_unregister(struct net *net,
559 const struct nf_conntrack_l4proto *const l4proto[],
560 unsigned int num_proto)
562 while (num_proto-- != 0)
563 nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
565 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
567 int nf_conntrack_proto_pernet_init(struct net *net)
570 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
571 &nf_conntrack_l4proto_generic);
573 err = nf_conntrack_l4proto_generic.init_net(net,
574 nf_conntrack_l4proto_generic.l3proto);
577 err = nf_ct_l4proto_register_sysctl(net,
579 &nf_conntrack_l4proto_generic);
587 void nf_conntrack_proto_pernet_fini(struct net *net)
589 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
590 &nf_conntrack_l4proto_generic);
593 nf_ct_l4proto_unregister_sysctl(net,
595 &nf_conntrack_l4proto_generic);
598 int nf_conntrack_proto_init(void)
601 for (i = 0; i < NFPROTO_NUMPROTO; i++)
602 rcu_assign_pointer(nf_ct_l3protos[i],
603 &nf_conntrack_l3proto_generic);
607 void nf_conntrack_proto_fini(void)
610 /* free l3proto protocol tables */
611 for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
612 kfree(nf_ct_protos[i]);