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>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/types.h>
13 #include <linux/netfilter.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/mutex.h>
17 #include <linux/vmalloc.h>
18 #include <linux/stddef.h>
19 #include <linux/err.h>
20 #include <linux/percpu.h>
21 #include <linux/notifier.h>
22 #include <linux/kernel.h>
23 #include <linux/netdevice.h>
24 #include <linux/rtnetlink.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[PF_MAX] __read_mostly;
32 struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[AF_MAX] __read_mostly;
33 EXPORT_SYMBOL_GPL(nf_ct_l3protos);
35 static DEFINE_MUTEX(nf_ct_proto_mutex);
39 nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_path *path,
40 struct ctl_table *table, unsigned int *users)
42 if (*header == NULL) {
43 *header = register_sysctl_paths(path, table);
53 nf_ct_unregister_sysctl(struct ctl_table_header **header,
54 struct ctl_table *table, unsigned int *users)
56 if (users != NULL && --*users > 0)
59 unregister_sysctl_table(*header);
64 struct nf_conntrack_l4proto *
65 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
67 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
68 return &nf_conntrack_l4proto_generic;
70 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
72 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
74 /* this is guaranteed to always return a valid protocol helper, since
75 * it falls back to generic_protocol */
76 struct nf_conntrack_l3proto *
77 nf_ct_l3proto_find_get(u_int16_t l3proto)
79 struct nf_conntrack_l3proto *p;
82 p = __nf_ct_l3proto_find(l3proto);
83 if (!try_module_get(p->me))
84 p = &nf_conntrack_l3proto_generic;
89 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
91 void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
95 EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
98 nf_ct_l3proto_try_module_get(unsigned short l3proto)
101 struct nf_conntrack_l3proto *p;
103 retry: p = nf_ct_l3proto_find_get(l3proto);
104 if (p == &nf_conntrack_l3proto_generic) {
105 ret = request_module("nf_conntrack-%d", l3proto);
114 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
116 void nf_ct_l3proto_module_put(unsigned short l3proto)
118 struct nf_conntrack_l3proto *p;
120 /* rcu_read_lock not necessary since the caller holds a reference, but
121 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
124 p = __nf_ct_l3proto_find(l3proto);
128 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
130 static int kill_l3proto(struct nf_conn *i, void *data)
132 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
135 static int kill_l4proto(struct nf_conn *i, void *data)
137 struct nf_conntrack_l4proto *l4proto;
138 l4proto = (struct nf_conntrack_l4proto *)data;
139 return nf_ct_protonum(i) == l4proto->l4proto &&
140 nf_ct_l3num(i) == l4proto->l3proto;
143 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
148 if (l3proto->ctl_table != NULL) {
149 err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
150 l3proto->ctl_table_path,
151 l3proto->ctl_table, NULL);
157 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
160 if (l3proto->ctl_table_header != NULL)
161 nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
162 l3proto->ctl_table, NULL);
166 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
169 struct nf_conntrack_l3proto *old;
171 if (proto->l3proto >= AF_MAX)
174 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
177 mutex_lock(&nf_ct_proto_mutex);
178 old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
179 lockdep_is_held(&nf_ct_proto_mutex));
180 if (old != &nf_conntrack_l3proto_generic) {
185 ret = nf_ct_l3proto_register_sysctl(proto);
189 if (proto->nlattr_tuple_size)
190 proto->nla_size = 3 * proto->nlattr_tuple_size();
192 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
195 mutex_unlock(&nf_ct_proto_mutex);
198 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
200 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
204 BUG_ON(proto->l3proto >= AF_MAX);
206 mutex_lock(&nf_ct_proto_mutex);
207 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
208 lockdep_is_held(&nf_ct_proto_mutex)
210 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
211 &nf_conntrack_l3proto_generic);
212 nf_ct_l3proto_unregister_sysctl(proto);
213 mutex_unlock(&nf_ct_proto_mutex);
217 /* Remove all contrack entries for this protocol */
220 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
223 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
225 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
230 if (l4proto->ctl_table != NULL) {
231 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
232 nf_net_netfilter_sysctl_path,
234 l4proto->ctl_table_users);
238 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
239 if (l4proto->ctl_compat_table != NULL) {
240 err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
241 nf_net_ipv4_netfilter_sysctl_path,
242 l4proto->ctl_compat_table, NULL);
245 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
247 l4proto->ctl_table_users);
249 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
251 #endif /* CONFIG_SYSCTL */
255 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
258 if (l4proto->ctl_table_header != NULL &&
259 *l4proto->ctl_table_header != NULL)
260 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
262 l4proto->ctl_table_users);
263 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
264 if (l4proto->ctl_compat_table_header != NULL)
265 nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
266 l4proto->ctl_compat_table, NULL);
267 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
268 #endif /* CONFIG_SYSCTL */
271 /* FIXME: Allow NULL functions and sub in pointers to generic for
273 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
277 if (l4proto->l3proto >= PF_MAX)
280 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
281 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
284 mutex_lock(&nf_ct_proto_mutex);
285 if (!nf_ct_protos[l4proto->l3proto]) {
286 /* l3proto may be loaded latter. */
287 struct nf_conntrack_l4proto __rcu **proto_array;
290 proto_array = kmalloc(MAX_NF_CT_PROTO *
291 sizeof(struct nf_conntrack_l4proto *),
293 if (proto_array == NULL) {
298 for (i = 0; i < MAX_NF_CT_PROTO; i++)
299 RCU_INIT_POINTER(proto_array[i], &nf_conntrack_l4proto_generic);
301 /* Before making proto_array visible to lockless readers,
302 * we must make sure its content is committed to memory.
306 nf_ct_protos[l4proto->l3proto] = proto_array;
307 } else if (rcu_dereference_protected(
308 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
309 lockdep_is_held(&nf_ct_proto_mutex)
310 ) != &nf_conntrack_l4proto_generic) {
315 ret = nf_ct_l4proto_register_sysctl(l4proto);
319 l4proto->nla_size = 0;
320 if (l4proto->nlattr_size)
321 l4proto->nla_size += l4proto->nlattr_size();
322 if (l4proto->nlattr_tuple_size)
323 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
325 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
329 mutex_unlock(&nf_ct_proto_mutex);
332 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
334 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
338 BUG_ON(l4proto->l3proto >= PF_MAX);
340 mutex_lock(&nf_ct_proto_mutex);
341 BUG_ON(rcu_dereference_protected(
342 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
343 lockdep_is_held(&nf_ct_proto_mutex)
345 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
346 &nf_conntrack_l4proto_generic);
347 nf_ct_l4proto_unregister_sysctl(l4proto);
348 mutex_unlock(&nf_ct_proto_mutex);
352 /* Remove all contrack entries for this protocol */
355 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
358 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
360 int nf_conntrack_proto_init(void)
365 err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
369 for (i = 0; i < AF_MAX; i++)
370 rcu_assign_pointer(nf_ct_l3protos[i],
371 &nf_conntrack_l3proto_generic);
375 void nf_conntrack_proto_fini(void)
379 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
381 /* free l3proto protocol tables */
382 for (i = 0; i < PF_MAX; i++)
383 kfree(nf_ct_protos[i]);