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 mutex_lock(&nf_ct_proto_mutex);
171 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
176 ret = nf_ct_l3proto_register_sysctl(proto);
180 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
183 mutex_unlock(&nf_ct_proto_mutex);
186 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
188 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
192 BUG_ON(proto->l3proto >= AF_MAX);
194 mutex_lock(&nf_ct_proto_mutex);
195 BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
196 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
197 &nf_conntrack_l3proto_generic);
198 nf_ct_l3proto_unregister_sysctl(proto);
199 mutex_unlock(&nf_ct_proto_mutex);
203 /* Remove all contrack entries for this protocol */
206 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
209 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
211 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
216 if (l4proto->ctl_table != NULL) {
217 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
218 nf_net_netfilter_sysctl_path,
220 l4proto->ctl_table_users);
224 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
225 if (l4proto->ctl_compat_table != NULL) {
226 err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
227 nf_net_ipv4_netfilter_sysctl_path,
228 l4proto->ctl_compat_table, NULL);
231 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
233 l4proto->ctl_table_users);
235 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
237 #endif /* CONFIG_SYSCTL */
241 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
244 if (l4proto->ctl_table_header != NULL &&
245 *l4proto->ctl_table_header != NULL)
246 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
248 l4proto->ctl_table_users);
249 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
250 if (l4proto->ctl_compat_table_header != NULL)
251 nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
252 l4proto->ctl_compat_table, NULL);
253 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
254 #endif /* CONFIG_SYSCTL */
257 /* FIXME: Allow NULL functions and sub in pointers to generic for
259 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
263 if (l4proto->l3proto >= PF_MAX)
266 mutex_lock(&nf_ct_proto_mutex);
267 if (!nf_ct_protos[l4proto->l3proto]) {
268 /* l3proto may be loaded latter. */
269 struct nf_conntrack_l4proto **proto_array;
272 proto_array = kmalloc(MAX_NF_CT_PROTO *
273 sizeof(struct nf_conntrack_l4proto *),
275 if (proto_array == NULL) {
280 for (i = 0; i < MAX_NF_CT_PROTO; i++)
281 proto_array[i] = &nf_conntrack_l4proto_generic;
282 nf_ct_protos[l4proto->l3proto] = proto_array;
283 } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
284 &nf_conntrack_l4proto_generic) {
289 ret = nf_ct_l4proto_register_sysctl(l4proto);
293 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
297 mutex_unlock(&nf_ct_proto_mutex);
300 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
302 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
306 BUG_ON(l4proto->l3proto >= PF_MAX);
308 mutex_lock(&nf_ct_proto_mutex);
309 BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
310 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
311 &nf_conntrack_l4proto_generic);
312 nf_ct_l4proto_unregister_sysctl(l4proto);
313 mutex_unlock(&nf_ct_proto_mutex);
317 /* Remove all contrack entries for this protocol */
320 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
323 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
325 int nf_conntrack_proto_init(void)
330 err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
334 for (i = 0; i < AF_MAX; i++)
335 rcu_assign_pointer(nf_ct_l3protos[i],
336 &nf_conntrack_l3proto_generic);
340 void nf_conntrack_proto_fini(void)
344 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
346 /* free l3proto protocol tables */
347 for (i = 0; i < PF_MAX; i++)
348 kfree(nf_ct_protos[i]);