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
]);