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/mutex.h>
16 #include <linux/skbuff.h>
17 #include <linux/vmalloc.h>
18 #include <linux/stddef.h>
19 #include <linux/err.h>
20 #include <linux/percpu.h>
21 #include <linux/moduleparam.h>
22 #include <linux/notifier.h>
23 #include <linux/kernel.h>
24 #include <linux/netdevice.h>
25 #include <linux/rtnetlink.h>
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_l3proto.h>
29 #include <net/netfilter/nf_conntrack_l4proto.h>
30 #include <net/netfilter/nf_conntrack_core.h>
32 static struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
33 struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
34 EXPORT_SYMBOL_GPL(nf_ct_l3protos);
36 static DEFINE_MUTEX(nf_ct_proto_mutex);
40 nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_path *path,
41 struct ctl_table *table, unsigned int *users)
43 if (*header == NULL) {
44 *header = register_sysctl_paths(path, table);
54 nf_ct_unregister_sysctl(struct ctl_table_header **header,
55 struct ctl_table *table, unsigned int *users)
57 if (users != NULL && --*users > 0)
60 unregister_sysctl_table(*header);
65 struct nf_conntrack_l4proto *
66 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
68 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
69 return &nf_conntrack_l4proto_generic;
71 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
73 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
75 /* this is guaranteed to always return a valid protocol helper, since
76 * it falls back to generic_protocol */
77 struct nf_conntrack_l3proto *
78 nf_ct_l3proto_find_get(u_int16_t l3proto)
80 struct nf_conntrack_l3proto *p;
83 p = __nf_ct_l3proto_find(l3proto);
84 if (!try_module_get(p->me))
85 p = &nf_conntrack_l3proto_generic;
90 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
92 void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
96 EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
99 nf_ct_l3proto_try_module_get(unsigned short l3proto)
102 struct nf_conntrack_l3proto *p;
104 retry: p = nf_ct_l3proto_find_get(l3proto);
105 if (p == &nf_conntrack_l3proto_generic) {
106 ret = request_module("nf_conntrack-%d", l3proto);
115 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
117 void nf_ct_l3proto_module_put(unsigned short l3proto)
119 struct nf_conntrack_l3proto *p;
121 /* rcu_read_lock not necessary since the caller holds a reference */
122 p = __nf_ct_l3proto_find(l3proto);
125 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
127 static int kill_l3proto(struct nf_conn *i, void *data)
129 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
132 static int kill_l4proto(struct nf_conn *i, void *data)
134 struct nf_conntrack_l4proto *l4proto;
135 l4proto = (struct nf_conntrack_l4proto *)data;
136 return nf_ct_protonum(i) == l4proto->l4proto &&
137 nf_ct_l3num(i) == l4proto->l3proto;
140 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
145 if (l3proto->ctl_table != NULL) {
146 err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
147 l3proto->ctl_table_path,
148 l3proto->ctl_table, NULL);
154 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
157 if (l3proto->ctl_table_header != NULL)
158 nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
159 l3proto->ctl_table, NULL);
163 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
167 if (proto->l3proto >= AF_MAX)
170 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
173 mutex_lock(&nf_ct_proto_mutex);
174 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
179 ret = nf_ct_l3proto_register_sysctl(proto);
183 if (proto->nlattr_tuple_size)
184 proto->nla_size = 3 * proto->nlattr_tuple_size();
186 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
189 mutex_unlock(&nf_ct_proto_mutex);
192 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
194 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
198 BUG_ON(proto->l3proto >= AF_MAX);
200 mutex_lock(&nf_ct_proto_mutex);
201 BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
202 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
203 &nf_conntrack_l3proto_generic);
204 nf_ct_l3proto_unregister_sysctl(proto);
205 mutex_unlock(&nf_ct_proto_mutex);
209 /* Remove all contrack entries for this protocol */
212 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
215 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
217 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
222 if (l4proto->ctl_table != NULL) {
223 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
224 nf_net_netfilter_sysctl_path,
226 l4proto->ctl_table_users);
230 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
231 if (l4proto->ctl_compat_table != NULL) {
232 err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
233 nf_net_ipv4_netfilter_sysctl_path,
234 l4proto->ctl_compat_table, NULL);
237 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
239 l4proto->ctl_table_users);
241 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
243 #endif /* CONFIG_SYSCTL */
247 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
250 if (l4proto->ctl_table_header != NULL &&
251 *l4proto->ctl_table_header != NULL)
252 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
254 l4proto->ctl_table_users);
255 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
256 if (l4proto->ctl_compat_table_header != NULL)
257 nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
258 l4proto->ctl_compat_table, NULL);
259 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
260 #endif /* CONFIG_SYSCTL */
263 /* FIXME: Allow NULL functions and sub in pointers to generic for
265 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
269 if (l4proto->l3proto >= PF_MAX)
272 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
273 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
276 mutex_lock(&nf_ct_proto_mutex);
277 if (!nf_ct_protos[l4proto->l3proto]) {
278 /* l3proto may be loaded latter. */
279 struct nf_conntrack_l4proto **proto_array;
282 proto_array = kmalloc(MAX_NF_CT_PROTO *
283 sizeof(struct nf_conntrack_l4proto *),
285 if (proto_array == NULL) {
290 for (i = 0; i < MAX_NF_CT_PROTO; i++)
291 proto_array[i] = &nf_conntrack_l4proto_generic;
292 nf_ct_protos[l4proto->l3proto] = proto_array;
293 } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
294 &nf_conntrack_l4proto_generic) {
299 ret = nf_ct_l4proto_register_sysctl(l4proto);
303 l4proto->nla_size = 0;
304 if (l4proto->nlattr_size)
305 l4proto->nla_size += l4proto->nlattr_size();
306 if (l4proto->nlattr_tuple_size)
307 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
309 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
313 mutex_unlock(&nf_ct_proto_mutex);
316 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
318 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
322 BUG_ON(l4proto->l3proto >= PF_MAX);
324 mutex_lock(&nf_ct_proto_mutex);
325 BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
326 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
327 &nf_conntrack_l4proto_generic);
328 nf_ct_l4proto_unregister_sysctl(l4proto);
329 mutex_unlock(&nf_ct_proto_mutex);
333 /* Remove all contrack entries for this protocol */
336 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
339 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
341 int nf_conntrack_proto_init(void)
346 err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
350 for (i = 0; i < AF_MAX; i++)
351 rcu_assign_pointer(nf_ct_l3protos[i],
352 &nf_conntrack_l3proto_generic);
356 void nf_conntrack_proto_fini(void)
360 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
362 /* free l3proto protocol tables */
363 for (i = 0; i < PF_MAX; i++)
364 kfree(nf_ct_protos[i]);