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_l4proto
*
78 nf_ct_l4proto_find_get(u_int16_t l3proto
, u_int8_t l4proto
)
80 struct nf_conntrack_l4proto
*p
;
83 p
= __nf_ct_l4proto_find(l3proto
, l4proto
);
84 if (!try_module_get(p
->me
))
85 p
= &nf_conntrack_l4proto_generic
;
90 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get
);
92 void nf_ct_l4proto_put(struct nf_conntrack_l4proto
*p
)
96 EXPORT_SYMBOL_GPL(nf_ct_l4proto_put
);
98 struct nf_conntrack_l3proto
*
99 nf_ct_l3proto_find_get(u_int16_t l3proto
)
101 struct nf_conntrack_l3proto
*p
;
104 p
= __nf_ct_l3proto_find(l3proto
);
105 if (!try_module_get(p
->me
))
106 p
= &nf_conntrack_l3proto_generic
;
111 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get
);
113 void nf_ct_l3proto_put(struct nf_conntrack_l3proto
*p
)
117 EXPORT_SYMBOL_GPL(nf_ct_l3proto_put
);
120 nf_ct_l3proto_try_module_get(unsigned short l3proto
)
123 struct nf_conntrack_l3proto
*p
;
125 retry
: p
= nf_ct_l3proto_find_get(l3proto
);
126 if (p
== &nf_conntrack_l3proto_generic
) {
127 ret
= request_module("nf_conntrack-%d", l3proto
);
136 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get
);
138 void nf_ct_l3proto_module_put(unsigned short l3proto
)
140 struct nf_conntrack_l3proto
*p
;
142 /* rcu_read_lock not necessary since the caller holds a reference */
143 p
= __nf_ct_l3proto_find(l3proto
);
146 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put
);
148 static int kill_l3proto(struct nf_conn
*i
, void *data
)
150 return nf_ct_l3num(i
) == ((struct nf_conntrack_l3proto
*)data
)->l3proto
;
153 static int kill_l4proto(struct nf_conn
*i
, void *data
)
155 struct nf_conntrack_l4proto
*l4proto
;
156 l4proto
= (struct nf_conntrack_l4proto
*)data
;
157 return nf_ct_protonum(i
) == l4proto
->l4proto
&&
158 nf_ct_l3num(i
) == l4proto
->l3proto
;
161 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto
*l3proto
)
166 if (l3proto
->ctl_table
!= NULL
) {
167 err
= nf_ct_register_sysctl(&l3proto
->ctl_table_header
,
168 l3proto
->ctl_table_path
,
169 l3proto
->ctl_table
, NULL
);
175 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto
*l3proto
)
178 if (l3proto
->ctl_table_header
!= NULL
)
179 nf_ct_unregister_sysctl(&l3proto
->ctl_table_header
,
180 l3proto
->ctl_table
, NULL
);
184 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto
*proto
)
188 if (proto
->l3proto
>= AF_MAX
)
191 mutex_lock(&nf_ct_proto_mutex
);
192 if (nf_ct_l3protos
[proto
->l3proto
] != &nf_conntrack_l3proto_generic
) {
197 ret
= nf_ct_l3proto_register_sysctl(proto
);
201 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
], proto
);
204 mutex_unlock(&nf_ct_proto_mutex
);
207 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register
);
209 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto
*proto
)
213 BUG_ON(proto
->l3proto
>= AF_MAX
);
215 mutex_lock(&nf_ct_proto_mutex
);
216 BUG_ON(nf_ct_l3protos
[proto
->l3proto
] != proto
);
217 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
],
218 &nf_conntrack_l3proto_generic
);
219 nf_ct_l3proto_unregister_sysctl(proto
);
220 mutex_unlock(&nf_ct_proto_mutex
);
224 /* Remove all contrack entries for this protocol */
227 nf_ct_iterate_cleanup(net
, kill_l3proto
, proto
);
230 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister
);
232 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto
*l4proto
)
237 if (l4proto
->ctl_table
!= NULL
) {
238 err
= nf_ct_register_sysctl(l4proto
->ctl_table_header
,
239 nf_net_netfilter_sysctl_path
,
241 l4proto
->ctl_table_users
);
245 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
246 if (l4proto
->ctl_compat_table
!= NULL
) {
247 err
= nf_ct_register_sysctl(&l4proto
->ctl_compat_table_header
,
248 nf_net_ipv4_netfilter_sysctl_path
,
249 l4proto
->ctl_compat_table
, NULL
);
252 nf_ct_unregister_sysctl(l4proto
->ctl_table_header
,
254 l4proto
->ctl_table_users
);
256 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
258 #endif /* CONFIG_SYSCTL */
262 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto
*l4proto
)
265 if (l4proto
->ctl_table_header
!= NULL
&&
266 *l4proto
->ctl_table_header
!= NULL
)
267 nf_ct_unregister_sysctl(l4proto
->ctl_table_header
,
269 l4proto
->ctl_table_users
);
270 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
271 if (l4proto
->ctl_compat_table_header
!= NULL
)
272 nf_ct_unregister_sysctl(&l4proto
->ctl_compat_table_header
,
273 l4proto
->ctl_compat_table
, NULL
);
274 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
275 #endif /* CONFIG_SYSCTL */
278 /* FIXME: Allow NULL functions and sub in pointers to generic for
280 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto
*l4proto
)
284 if (l4proto
->l3proto
>= PF_MAX
)
287 mutex_lock(&nf_ct_proto_mutex
);
288 if (!nf_ct_protos
[l4proto
->l3proto
]) {
289 /* l3proto may be loaded latter. */
290 struct nf_conntrack_l4proto
**proto_array
;
293 proto_array
= kmalloc(MAX_NF_CT_PROTO
*
294 sizeof(struct nf_conntrack_l4proto
*),
296 if (proto_array
== NULL
) {
301 for (i
= 0; i
< MAX_NF_CT_PROTO
; i
++)
302 proto_array
[i
] = &nf_conntrack_l4proto_generic
;
303 nf_ct_protos
[l4proto
->l3proto
] = proto_array
;
304 } else if (nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
] !=
305 &nf_conntrack_l4proto_generic
) {
310 ret
= nf_ct_l4proto_register_sysctl(l4proto
);
314 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
318 mutex_unlock(&nf_ct_proto_mutex
);
321 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register
);
323 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto
*l4proto
)
327 BUG_ON(l4proto
->l3proto
>= PF_MAX
);
329 mutex_lock(&nf_ct_proto_mutex
);
330 BUG_ON(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
] != l4proto
);
331 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
332 &nf_conntrack_l4proto_generic
);
333 nf_ct_l4proto_unregister_sysctl(l4proto
);
334 mutex_unlock(&nf_ct_proto_mutex
);
338 /* Remove all contrack entries for this protocol */
341 nf_ct_iterate_cleanup(net
, kill_l4proto
, l4proto
);
344 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister
);
346 int nf_conntrack_proto_init(void)
351 err
= nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic
);
355 for (i
= 0; i
< AF_MAX
; i
++)
356 rcu_assign_pointer(nf_ct_l3protos
[i
],
357 &nf_conntrack_l3proto_generic
);
361 void nf_conntrack_proto_fini(void)
365 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic
);
367 /* free l3proto protocol tables */
368 for (i
= 0; i
< PF_MAX
; i
++)
369 kfree(nf_ct_protos
[i
]);