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/vmalloc.h>
17 #include <linux/stddef.h>
18 #include <linux/err.h>
19 #include <linux/percpu.h>
20 #include <linux/notifier.h>
21 #include <linux/kernel.h>
22 #include <linux/netdevice.h>
23 #include <linux/rtnetlink.h>
25 #include <net/netfilter/nf_conntrack.h>
26 #include <net/netfilter/nf_conntrack_l3proto.h>
27 #include <net/netfilter/nf_conntrack_l4proto.h>
28 #include <net/netfilter/nf_conntrack_core.h>
30 static struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
31 struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
32 EXPORT_SYMBOL_GPL(nf_ct_l3protos);
34 static DEFINE_MUTEX(nf_ct_proto_mutex);
38 nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_path *path,
39 struct ctl_table *table, unsigned int *users)
41 if (*header == NULL) {
42 *header = register_sysctl_paths(path, table);
52 nf_ct_unregister_sysctl(struct ctl_table_header **header,
53 struct ctl_table *table, unsigned int *users)
55 if (users != NULL && --*users > 0)
58 unregister_sysctl_table(*header);
63 struct nf_conntrack_l4proto *
64 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
66 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
67 return &nf_conntrack_l4proto_generic;
69 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
71 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
73 /* this is guaranteed to always return a valid protocol helper, since
74 * it falls back to generic_protocol */
75 struct nf_conntrack_l3proto *
76 nf_ct_l3proto_find_get(u_int16_t l3proto)
78 struct nf_conntrack_l3proto *p;
81 p = __nf_ct_l3proto_find(l3proto);
82 if (!try_module_get(p->me))
83 p = &nf_conntrack_l3proto_generic;
88 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
90 void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
94 EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
97 nf_ct_l3proto_try_module_get(unsigned short l3proto)
100 struct nf_conntrack_l3proto *p;
102 retry: p = nf_ct_l3proto_find_get(l3proto);
103 if (p == &nf_conntrack_l3proto_generic) {
104 ret = request_module("nf_conntrack-%d", l3proto);
113 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
115 void nf_ct_l3proto_module_put(unsigned short l3proto)
117 struct nf_conntrack_l3proto *p;
119 /* rcu_read_lock not necessary since the caller holds a reference */
120 p = __nf_ct_l3proto_find(l3proto);
123 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
125 static int kill_l3proto(struct nf_conn *i, void *data)
127 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
130 static int kill_l4proto(struct nf_conn *i, void *data)
132 struct nf_conntrack_l4proto *l4proto;
133 l4proto = (struct nf_conntrack_l4proto *)data;
134 return nf_ct_protonum(i) == l4proto->l4proto &&
135 nf_ct_l3num(i) == l4proto->l3proto;
138 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
143 if (l3proto->ctl_table != NULL) {
144 err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
145 l3proto->ctl_table_path,
146 l3proto->ctl_table, NULL);
152 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
155 if (l3proto->ctl_table_header != NULL)
156 nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
157 l3proto->ctl_table, NULL);
161 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
165 if (proto->l3proto >= AF_MAX)
168 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
171 mutex_lock(&nf_ct_proto_mutex);
172 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
177 ret = nf_ct_l3proto_register_sysctl(proto);
181 if (proto->nlattr_tuple_size)
182 proto->nla_size = 3 * proto->nlattr_tuple_size();
184 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
187 mutex_unlock(&nf_ct_proto_mutex);
190 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
192 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
196 BUG_ON(proto->l3proto >= AF_MAX);
198 mutex_lock(&nf_ct_proto_mutex);
199 BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
200 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
201 &nf_conntrack_l3proto_generic);
202 nf_ct_l3proto_unregister_sysctl(proto);
203 mutex_unlock(&nf_ct_proto_mutex);
207 /* Remove all contrack entries for this protocol */
210 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
213 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
215 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
220 if (l4proto->ctl_table != NULL) {
221 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
222 nf_net_netfilter_sysctl_path,
224 l4proto->ctl_table_users);
228 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
229 if (l4proto->ctl_compat_table != NULL) {
230 err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
231 nf_net_ipv4_netfilter_sysctl_path,
232 l4proto->ctl_compat_table, NULL);
235 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
237 l4proto->ctl_table_users);
239 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
241 #endif /* CONFIG_SYSCTL */
245 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
248 if (l4proto->ctl_table_header != NULL &&
249 *l4proto->ctl_table_header != NULL)
250 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
252 l4proto->ctl_table_users);
253 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
254 if (l4proto->ctl_compat_table_header != NULL)
255 nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
256 l4proto->ctl_compat_table, NULL);
257 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
258 #endif /* CONFIG_SYSCTL */
261 /* FIXME: Allow NULL functions and sub in pointers to generic for
263 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
267 if (l4proto->l3proto >= PF_MAX)
270 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
271 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
274 mutex_lock(&nf_ct_proto_mutex);
275 if (!nf_ct_protos[l4proto->l3proto]) {
276 /* l3proto may be loaded latter. */
277 struct nf_conntrack_l4proto **proto_array;
280 proto_array = kmalloc(MAX_NF_CT_PROTO *
281 sizeof(struct nf_conntrack_l4proto *),
283 if (proto_array == NULL) {
288 for (i = 0; i < MAX_NF_CT_PROTO; i++)
289 proto_array[i] = &nf_conntrack_l4proto_generic;
290 nf_ct_protos[l4proto->l3proto] = proto_array;
291 } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
292 &nf_conntrack_l4proto_generic) {
297 ret = nf_ct_l4proto_register_sysctl(l4proto);
301 l4proto->nla_size = 0;
302 if (l4proto->nlattr_size)
303 l4proto->nla_size += l4proto->nlattr_size();
304 if (l4proto->nlattr_tuple_size)
305 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
307 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
311 mutex_unlock(&nf_ct_proto_mutex);
314 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
316 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
320 BUG_ON(l4proto->l3proto >= PF_MAX);
322 mutex_lock(&nf_ct_proto_mutex);
323 BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
324 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
325 &nf_conntrack_l4proto_generic);
326 nf_ct_l4proto_unregister_sysctl(l4proto);
327 mutex_unlock(&nf_ct_proto_mutex);
331 /* Remove all contrack entries for this protocol */
334 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
337 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
339 int nf_conntrack_proto_init(void)
344 err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
348 for (i = 0; i < AF_MAX; i++)
349 rcu_assign_pointer(nf_ct_l3protos[i],
350 &nf_conntrack_l3proto_generic);
354 void nf_conntrack_proto_fini(void)
358 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
360 /* free l3proto protocol tables */
361 for (i = 0; i < PF_MAX; i++)
362 kfree(nf_ct_protos[i]);