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/skbuff.h>
18 #include <linux/vmalloc.h>
19 #include <linux/stddef.h>
20 #include <linux/err.h>
21 #include <linux/percpu.h>
22 #include <linux/moduleparam.h>
23 #include <linux/notifier.h>
24 #include <linux/kernel.h>
25 #include <linux/netdevice.h>
26 #include <linux/rtnetlink.h>
28 #include <net/netfilter/nf_conntrack.h>
29 #include <net/netfilter/nf_conntrack_l3proto.h>
30 #include <net/netfilter/nf_conntrack_l4proto.h>
31 #include <net/netfilter/nf_conntrack_core.h>
33 static struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
34 struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
35 EXPORT_SYMBOL_GPL(nf_ct_l3protos);
37 static DEFINE_MUTEX(nf_ct_proto_mutex);
41 nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_path *path,
42 struct ctl_table *table, unsigned int *users)
44 if (*header == NULL) {
45 *header = register_sysctl_paths(path, table);
55 nf_ct_unregister_sysctl(struct ctl_table_header **header,
56 struct ctl_table *table, unsigned int *users)
58 if (users != NULL && --*users > 0)
61 unregister_sysctl_table(*header);
66 struct nf_conntrack_l4proto *
67 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
69 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
70 return &nf_conntrack_l4proto_generic;
72 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
74 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
76 /* this is guaranteed to always return a valid protocol helper, since
77 * it falls back to generic_protocol */
78 struct nf_conntrack_l3proto *
79 nf_ct_l3proto_find_get(u_int16_t l3proto)
81 struct nf_conntrack_l3proto *p;
84 p = __nf_ct_l3proto_find(l3proto);
85 if (!try_module_get(p->me))
86 p = &nf_conntrack_l3proto_generic;
91 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
93 void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
97 EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
100 nf_ct_l3proto_try_module_get(unsigned short l3proto)
103 struct nf_conntrack_l3proto *p;
105 retry: p = nf_ct_l3proto_find_get(l3proto);
106 if (p == &nf_conntrack_l3proto_generic) {
107 ret = request_module("nf_conntrack-%d", l3proto);
116 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
118 void nf_ct_l3proto_module_put(unsigned short l3proto)
120 struct nf_conntrack_l3proto *p;
122 /* rcu_read_lock not necessary since the caller holds a reference */
123 p = __nf_ct_l3proto_find(l3proto);
126 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
128 static int kill_l3proto(struct nf_conn *i, void *data)
130 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
133 static int kill_l4proto(struct nf_conn *i, void *data)
135 struct nf_conntrack_l4proto *l4proto;
136 l4proto = (struct nf_conntrack_l4proto *)data;
137 return nf_ct_protonum(i) == l4proto->l4proto &&
138 nf_ct_l3num(i) == l4proto->l3proto;
141 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
146 if (l3proto->ctl_table != NULL) {
147 err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
148 l3proto->ctl_table_path,
149 l3proto->ctl_table, NULL);
155 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
158 if (l3proto->ctl_table_header != NULL)
159 nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
160 l3proto->ctl_table, NULL);
164 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
168 if (proto->l3proto >= AF_MAX)
171 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
174 mutex_lock(&nf_ct_proto_mutex);
175 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
180 ret = nf_ct_l3proto_register_sysctl(proto);
184 if (proto->nlattr_tuple_size)
185 proto->nla_size = 3 * proto->nlattr_tuple_size();
187 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
190 mutex_unlock(&nf_ct_proto_mutex);
193 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
195 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
199 BUG_ON(proto->l3proto >= AF_MAX);
201 mutex_lock(&nf_ct_proto_mutex);
202 BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
203 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
204 &nf_conntrack_l3proto_generic);
205 nf_ct_l3proto_unregister_sysctl(proto);
206 mutex_unlock(&nf_ct_proto_mutex);
210 /* Remove all contrack entries for this protocol */
213 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
216 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
218 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
223 if (l4proto->ctl_table != NULL) {
224 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
225 nf_net_netfilter_sysctl_path,
227 l4proto->ctl_table_users);
231 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
232 if (l4proto->ctl_compat_table != NULL) {
233 err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
234 nf_net_ipv4_netfilter_sysctl_path,
235 l4proto->ctl_compat_table, NULL);
238 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
240 l4proto->ctl_table_users);
242 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
244 #endif /* CONFIG_SYSCTL */
248 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
251 if (l4proto->ctl_table_header != NULL &&
252 *l4proto->ctl_table_header != NULL)
253 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
255 l4proto->ctl_table_users);
256 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
257 if (l4proto->ctl_compat_table_header != NULL)
258 nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
259 l4proto->ctl_compat_table, NULL);
260 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
261 #endif /* CONFIG_SYSCTL */
264 /* FIXME: Allow NULL functions and sub in pointers to generic for
266 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
270 if (l4proto->l3proto >= PF_MAX)
273 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
274 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
277 mutex_lock(&nf_ct_proto_mutex);
278 if (!nf_ct_protos[l4proto->l3proto]) {
279 /* l3proto may be loaded latter. */
280 struct nf_conntrack_l4proto **proto_array;
283 proto_array = kmalloc(MAX_NF_CT_PROTO *
284 sizeof(struct nf_conntrack_l4proto *),
286 if (proto_array == NULL) {
291 for (i = 0; i < MAX_NF_CT_PROTO; i++)
292 proto_array[i] = &nf_conntrack_l4proto_generic;
293 nf_ct_protos[l4proto->l3proto] = proto_array;
294 } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
295 &nf_conntrack_l4proto_generic) {
300 ret = nf_ct_l4proto_register_sysctl(l4proto);
304 l4proto->nla_size = 0;
305 if (l4proto->nlattr_size)
306 l4proto->nla_size += l4proto->nlattr_size();
307 if (l4proto->nlattr_tuple_size)
308 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
310 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
314 mutex_unlock(&nf_ct_proto_mutex);
317 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
319 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
323 BUG_ON(l4proto->l3proto >= PF_MAX);
325 mutex_lock(&nf_ct_proto_mutex);
326 BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
327 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
328 &nf_conntrack_l4proto_generic);
329 nf_ct_l4proto_unregister_sysctl(l4proto);
330 mutex_unlock(&nf_ct_proto_mutex);
334 /* Remove all contrack entries for this protocol */
337 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
340 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
342 int nf_conntrack_proto_init(void)
347 err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
351 for (i = 0; i < AF_MAX; i++)
352 rcu_assign_pointer(nf_ct_l3protos[i],
353 &nf_conntrack_l3proto_generic);
357 void nf_conntrack_proto_fini(void)
361 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
363 /* free l3proto protocol tables */
364 for (i = 0; i < PF_MAX; i++)
365 kfree(nf_ct_protos[i]);