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 const 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 const 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)
98 const 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 const struct nf_conntrack_l4proto *
177 nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
179 const 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(const 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) == ((const struct nf_conntrack_l3proto *)data)->l3proto;
202 static int kill_l4proto(struct nf_conn *i, void *data)
204 const 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(const struct nf_conntrack_l3proto *proto)
213 struct nf_conntrack_l3proto *old;
215 if (proto->l3proto >= NFPROTO_NUMPROTO)
217 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
218 if (proto->tuple_to_nlattr && proto->nla_size == 0)
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 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
232 mutex_unlock(&nf_ct_proto_mutex);
236 EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
238 void nf_ct_l3proto_unregister(const struct nf_conntrack_l3proto *proto)
240 BUG_ON(proto->l3proto >= NFPROTO_NUMPROTO);
242 mutex_lock(&nf_ct_proto_mutex);
243 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
244 lockdep_is_held(&nf_ct_proto_mutex)
246 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
247 &nf_conntrack_l3proto_generic);
248 mutex_unlock(&nf_ct_proto_mutex);
251 /* Remove all contrack entries for this protocol */
252 nf_ct_iterate_destroy(kill_l3proto, (void*)proto);
254 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
256 static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
257 const struct nf_conntrack_l4proto *l4proto)
259 if (l4proto->get_net_proto) {
260 /* statically built-in protocols use static per-net */
261 return l4proto->get_net_proto(net);
262 } else if (l4proto->net_id) {
263 /* ... and loadable protocols use dynamic per-net */
264 return net_generic(net, *l4proto->net_id);
270 int nf_ct_l4proto_register_sysctl(struct net *net,
271 struct nf_proto_net *pn,
272 const struct nf_conntrack_l4proto *l4proto)
277 if (pn->ctl_table != NULL) {
278 err = nf_ct_register_sysctl(net,
279 &pn->ctl_table_header,
284 kfree(pn->ctl_table);
285 pn->ctl_table = NULL;
289 #endif /* CONFIG_SYSCTL */
294 void nf_ct_l4proto_unregister_sysctl(struct net *net,
295 struct nf_proto_net *pn,
296 const struct nf_conntrack_l4proto *l4proto)
299 if (pn->ctl_table_header != NULL)
300 nf_ct_unregister_sysctl(&pn->ctl_table_header,
303 #endif /* CONFIG_SYSCTL */
306 /* FIXME: Allow NULL functions and sub in pointers to generic for
308 int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *l4proto)
312 if (l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos))
315 if ((l4proto->to_nlattr && !l4proto->nlattr_size) ||
316 (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
319 mutex_lock(&nf_ct_proto_mutex);
320 if (!nf_ct_protos[l4proto->l3proto]) {
321 /* l3proto may be loaded latter. */
322 struct nf_conntrack_l4proto __rcu **proto_array;
325 proto_array = kmalloc(MAX_NF_CT_PROTO *
326 sizeof(struct nf_conntrack_l4proto *),
328 if (proto_array == NULL) {
333 for (i = 0; i < MAX_NF_CT_PROTO; i++)
334 RCU_INIT_POINTER(proto_array[i],
335 &nf_conntrack_l4proto_generic);
337 /* Before making proto_array visible to lockless readers,
338 * we must make sure its content is committed to memory.
342 nf_ct_protos[l4proto->l3proto] = proto_array;
343 } else if (rcu_dereference_protected(
344 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
345 lockdep_is_held(&nf_ct_proto_mutex)
346 ) != &nf_conntrack_l4proto_generic) {
351 l4proto->nla_size = 0;
352 if (l4proto->nlattr_size)
353 l4proto->nla_size += l4proto->nlattr_size();
354 if (l4proto->nlattr_tuple_size)
355 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
357 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
360 mutex_unlock(&nf_ct_proto_mutex);
363 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);
365 int nf_ct_l4proto_pernet_register_one(struct net *net,
366 const struct nf_conntrack_l4proto *l4proto)
369 struct nf_proto_net *pn = NULL;
371 if (l4proto->init_net) {
372 ret = l4proto->init_net(net, l4proto->l3proto);
377 pn = nf_ct_l4proto_net(net, l4proto);
381 ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
389 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);
391 static void __nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
394 BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));
396 BUG_ON(rcu_dereference_protected(
397 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
398 lockdep_is_held(&nf_ct_proto_mutex)
400 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
401 &nf_conntrack_l4proto_generic);
404 void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
406 mutex_lock(&nf_ct_proto_mutex);
407 __nf_ct_l4proto_unregister_one(l4proto);
408 mutex_unlock(&nf_ct_proto_mutex);
412 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);
414 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
415 const struct nf_conntrack_l4proto *l4proto)
417 struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);
423 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
425 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister_one);
427 int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto[],
428 unsigned int num_proto)
430 int ret = -EINVAL, ver;
433 for (i = 0; i < num_proto; i++) {
434 ret = nf_ct_l4proto_register_one(l4proto[i]);
438 if (i != num_proto) {
439 ver = l4proto[i]->l3proto == PF_INET6 ? 6 : 4;
440 pr_err("nf_conntrack_ipv%d: can't register l4 %d proto.\n",
441 ver, l4proto[i]->l4proto);
442 nf_ct_l4proto_unregister(l4proto, i);
446 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
448 int nf_ct_l4proto_pernet_register(struct net *net,
449 struct nf_conntrack_l4proto *const l4proto[],
450 unsigned int num_proto)
455 for (i = 0; i < num_proto; i++) {
456 ret = nf_ct_l4proto_pernet_register_one(net, l4proto[i]);
460 if (i != num_proto) {
461 pr_err("nf_conntrack_proto_%d %d: pernet registration failed\n",
463 l4proto[i]->l3proto == PF_INET6 ? 6 : 4);
464 nf_ct_l4proto_pernet_unregister(net, l4proto, i);
468 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
470 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto[],
471 unsigned int num_proto)
473 mutex_lock(&nf_ct_proto_mutex);
474 while (num_proto-- != 0)
475 __nf_ct_l4proto_unregister_one(l4proto[num_proto]);
476 mutex_unlock(&nf_ct_proto_mutex);
479 /* Remove all contrack entries for this protocol */
480 nf_ct_iterate_destroy(kill_l4proto, l4proto);
482 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
484 void nf_ct_l4proto_pernet_unregister(struct net *net,
485 struct nf_conntrack_l4proto *const l4proto[],
486 unsigned int num_proto)
488 while (num_proto-- != 0)
489 nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
491 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
493 int nf_conntrack_proto_pernet_init(struct net *net)
496 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
497 &nf_conntrack_l4proto_generic);
499 err = nf_conntrack_l4proto_generic.init_net(net,
500 nf_conntrack_l4proto_generic.l3proto);
503 err = nf_ct_l4proto_register_sysctl(net,
505 &nf_conntrack_l4proto_generic);
513 void nf_conntrack_proto_pernet_fini(struct net *net)
515 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
516 &nf_conntrack_l4proto_generic);
519 nf_ct_l4proto_unregister_sysctl(net,
521 &nf_conntrack_l4proto_generic);
524 int nf_conntrack_proto_init(void)
527 for (i = 0; i < NFPROTO_NUMPROTO; i++)
528 rcu_assign_pointer(nf_ct_l3protos[i],
529 &nf_conntrack_l3proto_generic);
533 void nf_conntrack_proto_fini(void)
536 /* free l3proto protocol tables */
537 for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
538 kfree(nf_ct_protos[i]);