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>
31 static struct nf_conntrack_l4proto __rcu **nf_ct_protos[NFPROTO_NUMPROTO] __read_mostly;
32 struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO] __read_mostly;
33 EXPORT_SYMBOL_GPL(nf_ct_l3protos);
35 static DEFINE_MUTEX(nf_ct_proto_mutex);
39 nf_ct_register_sysctl(struct net *net,
40 struct ctl_table_header **header,
42 struct ctl_table *table)
44 if (*header == NULL) {
45 *header = register_net_sysctl(net, path, table);
54 nf_ct_unregister_sysctl(struct ctl_table_header **header,
55 struct ctl_table **table,
61 unregister_net_sysctl_table(*header);
68 struct nf_conntrack_l4proto *
69 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
71 if (unlikely(l3proto >= NFPROTO_NUMPROTO || nf_ct_protos[l3proto] == NULL))
72 return &nf_conntrack_l4proto_generic;
74 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
76 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
78 /* this is guaranteed to always return a valid protocol helper, since
79 * it falls back to generic_protocol */
80 struct nf_conntrack_l3proto *
81 nf_ct_l3proto_find_get(u_int16_t l3proto)
83 struct nf_conntrack_l3proto *p;
86 p = __nf_ct_l3proto_find(l3proto);
87 if (!try_module_get(p->me))
88 p = &nf_conntrack_l3proto_generic;
93 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
96 nf_ct_l3proto_try_module_get(unsigned short l3proto)
99 struct nf_conntrack_l3proto *p;
101 retry: p = nf_ct_l3proto_find_get(l3proto);
102 if (p == &nf_conntrack_l3proto_generic) {
103 ret = request_module("nf_conntrack-%d", l3proto);
112 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
114 void nf_ct_l3proto_module_put(unsigned short l3proto)
116 struct nf_conntrack_l3proto *p;
118 /* rcu_read_lock not necessary since the caller holds a reference, but
119 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
122 p = __nf_ct_l3proto_find(l3proto);
126 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
128 int nf_ct_netns_get(struct net *net, u8 nfproto)
130 const struct nf_conntrack_l3proto *l3proto;
135 ret = nf_ct_l3proto_try_module_get(nfproto);
139 /* we already have a reference, can't fail */
141 l3proto = __nf_ct_l3proto_find(nfproto);
144 if (!l3proto->net_ns_get)
147 ret = l3proto->net_ns_get(net);
149 nf_ct_l3proto_module_put(nfproto);
153 EXPORT_SYMBOL_GPL(nf_ct_netns_get);
155 void nf_ct_netns_put(struct net *net, u8 nfproto)
157 const struct nf_conntrack_l3proto *l3proto;
161 /* same as nf_conntrack_netns_get(), reference assumed */
163 l3proto = __nf_ct_l3proto_find(nfproto);
166 if (WARN_ON(!l3proto))
169 if (l3proto->net_ns_put)
170 l3proto->net_ns_put(net);
172 nf_ct_l3proto_module_put(nfproto);
174 EXPORT_SYMBOL_GPL(nf_ct_netns_put);
176 struct nf_conntrack_l4proto *
177 nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
179 struct nf_conntrack_l4proto *p;
182 p = __nf_ct_l4proto_find(l3num, l4num);
183 if (!try_module_get(p->me))
184 p = &nf_conntrack_l4proto_generic;
189 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
191 void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
195 EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
197 static int kill_l3proto(struct nf_conn *i, void *data)
199 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
202 static int kill_l4proto(struct nf_conn *i, void *data)
204 struct nf_conntrack_l4proto *l4proto;
206 return nf_ct_protonum(i) == l4proto->l4proto &&
207 nf_ct_l3num(i) == l4proto->l3proto;
210 int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
213 struct nf_conntrack_l3proto *old;
215 if (proto->l3proto >= NFPROTO_NUMPROTO)
218 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
221 mutex_lock(&nf_ct_proto_mutex);
222 old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
223 lockdep_is_held(&nf_ct_proto_mutex));
224 if (old != &nf_conntrack_l3proto_generic) {
229 if (proto->nlattr_tuple_size)
230 proto->nla_size = 3 * proto->nlattr_tuple_size();
232 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
235 mutex_unlock(&nf_ct_proto_mutex);
239 EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
242 extern unsigned int nf_conntrack_default_on;
244 int nf_ct_l3proto_pernet_register(struct net *net,
245 struct nf_conntrack_l3proto *proto)
247 if (nf_conntrack_default_on == 0)
250 return proto->net_ns_get ? proto->net_ns_get(net) : 0;
252 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register);
255 void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
257 BUG_ON(proto->l3proto >= NFPROTO_NUMPROTO);
259 mutex_lock(&nf_ct_proto_mutex);
260 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
261 lockdep_is_held(&nf_ct_proto_mutex)
263 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
264 &nf_conntrack_l3proto_generic);
265 mutex_unlock(&nf_ct_proto_mutex);
268 /* Remove all contrack entries for this protocol */
269 nf_ct_iterate_destroy(kill_l3proto, proto);
271 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
273 void nf_ct_l3proto_pernet_unregister(struct net *net,
274 struct nf_conntrack_l3proto *proto)
277 * nf_conntrack_default_on *might* have registered hooks.
278 * ->net_ns_put must cope with more puts() than get(), i.e.
279 * if nf_conntrack_default_on was 0 at time of
280 * nf_ct_l3proto_pernet_register invocation this net_ns_put()
283 if (proto->net_ns_put)
284 proto->net_ns_put(net);
286 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister);
288 static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
289 struct nf_conntrack_l4proto *l4proto)
291 if (l4proto->get_net_proto) {
292 /* statically built-in protocols use static per-net */
293 return l4proto->get_net_proto(net);
294 } else if (l4proto->net_id) {
295 /* ... and loadable protocols use dynamic per-net */
296 return net_generic(net, *l4proto->net_id);
302 int nf_ct_l4proto_register_sysctl(struct net *net,
303 struct nf_proto_net *pn,
304 struct nf_conntrack_l4proto *l4proto)
309 if (pn->ctl_table != NULL) {
310 err = nf_ct_register_sysctl(net,
311 &pn->ctl_table_header,
316 kfree(pn->ctl_table);
317 pn->ctl_table = NULL;
321 #endif /* CONFIG_SYSCTL */
326 void nf_ct_l4proto_unregister_sysctl(struct net *net,
327 struct nf_proto_net *pn,
328 struct nf_conntrack_l4proto *l4proto)
331 if (pn->ctl_table_header != NULL)
332 nf_ct_unregister_sysctl(&pn->ctl_table_header,
335 #endif /* CONFIG_SYSCTL */
338 /* FIXME: Allow NULL functions and sub in pointers to generic for
340 int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *l4proto)
344 if (l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos))
347 if ((l4proto->to_nlattr && !l4proto->nlattr_size) ||
348 (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
351 mutex_lock(&nf_ct_proto_mutex);
352 if (!nf_ct_protos[l4proto->l3proto]) {
353 /* l3proto may be loaded latter. */
354 struct nf_conntrack_l4proto __rcu **proto_array;
357 proto_array = kmalloc(MAX_NF_CT_PROTO *
358 sizeof(struct nf_conntrack_l4proto *),
360 if (proto_array == NULL) {
365 for (i = 0; i < MAX_NF_CT_PROTO; i++)
366 RCU_INIT_POINTER(proto_array[i],
367 &nf_conntrack_l4proto_generic);
369 /* Before making proto_array visible to lockless readers,
370 * we must make sure its content is committed to memory.
374 nf_ct_protos[l4proto->l3proto] = proto_array;
375 } else if (rcu_dereference_protected(
376 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
377 lockdep_is_held(&nf_ct_proto_mutex)
378 ) != &nf_conntrack_l4proto_generic) {
383 l4proto->nla_size = 0;
384 if (l4proto->nlattr_size)
385 l4proto->nla_size += l4proto->nlattr_size();
386 if (l4proto->nlattr_tuple_size)
387 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
389 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
392 mutex_unlock(&nf_ct_proto_mutex);
395 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);
397 int nf_ct_l4proto_pernet_register_one(struct net *net,
398 struct nf_conntrack_l4proto *l4proto)
401 struct nf_proto_net *pn = NULL;
403 if (l4proto->init_net) {
404 ret = l4proto->init_net(net, l4proto->l3proto);
409 pn = nf_ct_l4proto_net(net, l4proto);
413 ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
421 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);
423 static void __nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
426 BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));
428 BUG_ON(rcu_dereference_protected(
429 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
430 lockdep_is_held(&nf_ct_proto_mutex)
432 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
433 &nf_conntrack_l4proto_generic);
436 void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
438 mutex_lock(&nf_ct_proto_mutex);
439 __nf_ct_l4proto_unregister_one(l4proto);
440 mutex_unlock(&nf_ct_proto_mutex);
444 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);
446 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
447 struct nf_conntrack_l4proto *l4proto)
449 struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);
455 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
457 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister_one);
459 int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto[],
460 unsigned int num_proto)
462 int ret = -EINVAL, ver;
465 for (i = 0; i < num_proto; i++) {
466 ret = nf_ct_l4proto_register_one(l4proto[i]);
470 if (i != num_proto) {
471 ver = l4proto[i]->l3proto == PF_INET6 ? 6 : 4;
472 pr_err("nf_conntrack_ipv%d: can't register %s%d proto.\n",
473 ver, l4proto[i]->name, ver);
474 nf_ct_l4proto_unregister(l4proto, i);
478 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
480 int nf_ct_l4proto_pernet_register(struct net *net,
481 struct nf_conntrack_l4proto *l4proto[],
482 unsigned int num_proto)
487 for (i = 0; i < num_proto; i++) {
488 ret = nf_ct_l4proto_pernet_register_one(net, l4proto[i]);
492 if (i != num_proto) {
493 pr_err("nf_conntrack_%s%d: pernet registration failed\n",
495 l4proto[i]->l3proto == PF_INET6 ? 6 : 4);
496 nf_ct_l4proto_pernet_unregister(net, l4proto, i);
500 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
502 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto[],
503 unsigned int num_proto)
505 mutex_lock(&nf_ct_proto_mutex);
506 while (num_proto-- != 0)
507 __nf_ct_l4proto_unregister_one(l4proto[num_proto]);
508 mutex_unlock(&nf_ct_proto_mutex);
511 /* Remove all contrack entries for this protocol */
512 nf_ct_iterate_destroy(kill_l4proto, l4proto);
514 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
516 void nf_ct_l4proto_pernet_unregister(struct net *net,
517 struct nf_conntrack_l4proto *l4proto[],
518 unsigned int num_proto)
520 while (num_proto-- != 0)
521 nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
523 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
525 int nf_conntrack_proto_pernet_init(struct net *net)
528 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
529 &nf_conntrack_l4proto_generic);
531 err = nf_conntrack_l4proto_generic.init_net(net,
532 nf_conntrack_l4proto_generic.l3proto);
535 err = nf_ct_l4proto_register_sysctl(net,
537 &nf_conntrack_l4proto_generic);
545 void nf_conntrack_proto_pernet_fini(struct net *net)
547 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
548 &nf_conntrack_l4proto_generic);
551 nf_ct_l4proto_unregister_sysctl(net,
553 &nf_conntrack_l4proto_generic);
556 int nf_conntrack_proto_init(void)
559 for (i = 0; i < NFPROTO_NUMPROTO; i++)
560 rcu_assign_pointer(nf_ct_l3protos[i],
561 &nf_conntrack_l3proto_generic);
565 void nf_conntrack_proto_fini(void)
568 /* free l3proto protocol tables */
569 for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
570 kfree(nf_ct_protos[i]);