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 **nf_ct_protos[PF_MAX] __read_mostly;
32 struct nf_conntrack_l3proto *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 */
121 p = __nf_ct_l3proto_find(l3proto);
124 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
126 static int kill_l3proto(struct nf_conn *i, void *data)
128 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
131 static int kill_l4proto(struct nf_conn *i, void *data)
133 struct nf_conntrack_l4proto *l4proto;
134 l4proto = (struct nf_conntrack_l4proto *)data;
135 return nf_ct_protonum(i) == l4proto->l4proto &&
136 nf_ct_l3num(i) == l4proto->l3proto;
139 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
144 if (l3proto->ctl_table != NULL) {
145 err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
146 l3proto->ctl_table_path,
147 l3proto->ctl_table, NULL);
153 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
156 if (l3proto->ctl_table_header != NULL)
157 nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
158 l3proto->ctl_table, NULL);
162 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
166 if (proto->l3proto >= AF_MAX)
169 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
172 mutex_lock(&nf_ct_proto_mutex);
173 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
178 ret = nf_ct_l3proto_register_sysctl(proto);
182 if (proto->nlattr_tuple_size)
183 proto->nla_size = 3 * proto->nlattr_tuple_size();
185 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
188 mutex_unlock(&nf_ct_proto_mutex);
191 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
193 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
197 BUG_ON(proto->l3proto >= AF_MAX);
199 mutex_lock(&nf_ct_proto_mutex);
200 BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
201 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
202 &nf_conntrack_l3proto_generic);
203 nf_ct_l3proto_unregister_sysctl(proto);
204 mutex_unlock(&nf_ct_proto_mutex);
208 /* Remove all contrack entries for this protocol */
211 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
214 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
216 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
221 if (l4proto->ctl_table != NULL) {
222 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
223 nf_net_netfilter_sysctl_path,
225 l4proto->ctl_table_users);
229 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
230 if (l4proto->ctl_compat_table != NULL) {
231 err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
232 nf_net_ipv4_netfilter_sysctl_path,
233 l4proto->ctl_compat_table, NULL);
236 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
238 l4proto->ctl_table_users);
240 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
242 #endif /* CONFIG_SYSCTL */
246 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
249 if (l4proto->ctl_table_header != NULL &&
250 *l4proto->ctl_table_header != NULL)
251 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
253 l4proto->ctl_table_users);
254 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
255 if (l4proto->ctl_compat_table_header != NULL)
256 nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
257 l4proto->ctl_compat_table, NULL);
258 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
259 #endif /* CONFIG_SYSCTL */
262 /* FIXME: Allow NULL functions and sub in pointers to generic for
264 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
268 if (l4proto->l3proto >= PF_MAX)
271 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
272 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
275 mutex_lock(&nf_ct_proto_mutex);
276 if (!nf_ct_protos[l4proto->l3proto]) {
277 /* l3proto may be loaded latter. */
278 struct nf_conntrack_l4proto **proto_array;
281 proto_array = kmalloc(MAX_NF_CT_PROTO *
282 sizeof(struct nf_conntrack_l4proto *),
284 if (proto_array == NULL) {
289 for (i = 0; i < MAX_NF_CT_PROTO; i++)
290 proto_array[i] = &nf_conntrack_l4proto_generic;
291 nf_ct_protos[l4proto->l3proto] = proto_array;
292 } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
293 &nf_conntrack_l4proto_generic) {
298 ret = nf_ct_l4proto_register_sysctl(l4proto);
302 l4proto->nla_size = 0;
303 if (l4proto->nlattr_size)
304 l4proto->nla_size += l4proto->nlattr_size();
305 if (l4proto->nlattr_tuple_size)
306 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
308 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
312 mutex_unlock(&nf_ct_proto_mutex);
315 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
317 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
321 BUG_ON(l4proto->l3proto >= PF_MAX);
323 mutex_lock(&nf_ct_proto_mutex);
324 BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
325 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
326 &nf_conntrack_l4proto_generic);
327 nf_ct_l4proto_unregister_sysctl(l4proto);
328 mutex_unlock(&nf_ct_proto_mutex);
332 /* Remove all contrack entries for this protocol */
335 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
338 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
340 int nf_conntrack_proto_init(void)
345 err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
349 for (i = 0; i < AF_MAX; i++)
350 rcu_assign_pointer(nf_ct_l3protos[i],
351 &nf_conntrack_l3proto_generic);
355 void nf_conntrack_proto_fini(void)
359 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
361 /* free l3proto protocol tables */
362 for (i = 0; i < PF_MAX; i++)
363 kfree(nf_ct_protos[i]);