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 __rcu
**nf_ct_protos
[PF_MAX
] __read_mostly
;
32 struct nf_conntrack_l3proto __rcu
*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, but
121 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
124 p
= __nf_ct_l3proto_find(l3proto
);
128 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put
);
130 struct nf_conntrack_l4proto
*
131 nf_ct_l4proto_find_get(u_int16_t l3num
, u_int8_t l4num
)
133 struct nf_conntrack_l4proto
*p
;
136 p
= __nf_ct_l4proto_find(l3num
, l4num
);
137 if (!try_module_get(p
->me
))
138 p
= &nf_conntrack_l4proto_generic
;
143 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get
);
145 void nf_ct_l4proto_put(struct nf_conntrack_l4proto
*p
)
149 EXPORT_SYMBOL_GPL(nf_ct_l4proto_put
);
151 static int kill_l3proto(struct nf_conn
*i
, void *data
)
153 return nf_ct_l3num(i
) == ((struct nf_conntrack_l3proto
*)data
)->l3proto
;
156 static int kill_l4proto(struct nf_conn
*i
, void *data
)
158 struct nf_conntrack_l4proto
*l4proto
;
159 l4proto
= (struct nf_conntrack_l4proto
*)data
;
160 return nf_ct_protonum(i
) == l4proto
->l4proto
&&
161 nf_ct_l3num(i
) == l4proto
->l3proto
;
164 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto
*l3proto
)
169 if (l3proto
->ctl_table
!= NULL
) {
170 err
= nf_ct_register_sysctl(&l3proto
->ctl_table_header
,
171 l3proto
->ctl_table_path
,
172 l3proto
->ctl_table
, NULL
);
178 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto
*l3proto
)
181 if (l3proto
->ctl_table_header
!= NULL
)
182 nf_ct_unregister_sysctl(&l3proto
->ctl_table_header
,
183 l3proto
->ctl_table
, NULL
);
187 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto
*proto
)
190 struct nf_conntrack_l3proto
*old
;
192 if (proto
->l3proto
>= AF_MAX
)
195 if (proto
->tuple_to_nlattr
&& !proto
->nlattr_tuple_size
)
198 mutex_lock(&nf_ct_proto_mutex
);
199 old
= rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
200 lockdep_is_held(&nf_ct_proto_mutex
));
201 if (old
!= &nf_conntrack_l3proto_generic
) {
206 ret
= nf_ct_l3proto_register_sysctl(proto
);
210 if (proto
->nlattr_tuple_size
)
211 proto
->nla_size
= 3 * proto
->nlattr_tuple_size();
213 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
], proto
);
216 mutex_unlock(&nf_ct_proto_mutex
);
219 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register
);
221 void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto
*proto
)
225 BUG_ON(proto
->l3proto
>= AF_MAX
);
227 mutex_lock(&nf_ct_proto_mutex
);
228 BUG_ON(rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
229 lockdep_is_held(&nf_ct_proto_mutex
)
231 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
],
232 &nf_conntrack_l3proto_generic
);
233 nf_ct_l3proto_unregister_sysctl(proto
);
234 mutex_unlock(&nf_ct_proto_mutex
);
238 /* Remove all contrack entries for this protocol */
241 nf_ct_iterate_cleanup(net
, kill_l3proto
, proto
);
244 EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister
);
246 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto
*l4proto
)
251 if (l4proto
->ctl_table
!= NULL
) {
252 err
= nf_ct_register_sysctl(l4proto
->ctl_table_header
,
253 nf_net_netfilter_sysctl_path
,
255 l4proto
->ctl_table_users
);
259 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
260 if (l4proto
->ctl_compat_table
!= NULL
) {
261 err
= nf_ct_register_sysctl(&l4proto
->ctl_compat_table_header
,
262 nf_net_ipv4_netfilter_sysctl_path
,
263 l4proto
->ctl_compat_table
, NULL
);
266 nf_ct_unregister_sysctl(l4proto
->ctl_table_header
,
268 l4proto
->ctl_table_users
);
270 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
272 #endif /* CONFIG_SYSCTL */
276 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto
*l4proto
)
279 if (l4proto
->ctl_table_header
!= NULL
&&
280 *l4proto
->ctl_table_header
!= NULL
)
281 nf_ct_unregister_sysctl(l4proto
->ctl_table_header
,
283 l4proto
->ctl_table_users
);
284 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
285 if (l4proto
->ctl_compat_table_header
!= NULL
)
286 nf_ct_unregister_sysctl(&l4proto
->ctl_compat_table_header
,
287 l4proto
->ctl_compat_table
, NULL
);
288 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
289 #endif /* CONFIG_SYSCTL */
292 /* FIXME: Allow NULL functions and sub in pointers to generic for
294 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto
*l4proto
)
298 if (l4proto
->l3proto
>= PF_MAX
)
301 if ((l4proto
->to_nlattr
&& !l4proto
->nlattr_size
)
302 || (l4proto
->tuple_to_nlattr
&& !l4proto
->nlattr_tuple_size
))
305 mutex_lock(&nf_ct_proto_mutex
);
306 if (!nf_ct_protos
[l4proto
->l3proto
]) {
307 /* l3proto may be loaded latter. */
308 struct nf_conntrack_l4proto __rcu
**proto_array
;
311 proto_array
= kmalloc(MAX_NF_CT_PROTO
*
312 sizeof(struct nf_conntrack_l4proto
*),
314 if (proto_array
== NULL
) {
319 for (i
= 0; i
< MAX_NF_CT_PROTO
; i
++)
320 RCU_INIT_POINTER(proto_array
[i
], &nf_conntrack_l4proto_generic
);
322 /* Before making proto_array visible to lockless readers,
323 * we must make sure its content is committed to memory.
327 nf_ct_protos
[l4proto
->l3proto
] = proto_array
;
328 } else if (rcu_dereference_protected(
329 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
330 lockdep_is_held(&nf_ct_proto_mutex
)
331 ) != &nf_conntrack_l4proto_generic
) {
336 ret
= nf_ct_l4proto_register_sysctl(l4proto
);
340 l4proto
->nla_size
= 0;
341 if (l4proto
->nlattr_size
)
342 l4proto
->nla_size
+= l4proto
->nlattr_size();
343 if (l4proto
->nlattr_tuple_size
)
344 l4proto
->nla_size
+= 3 * l4proto
->nlattr_tuple_size();
346 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
350 mutex_unlock(&nf_ct_proto_mutex
);
353 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register
);
355 void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto
*l4proto
)
359 BUG_ON(l4proto
->l3proto
>= PF_MAX
);
361 mutex_lock(&nf_ct_proto_mutex
);
362 BUG_ON(rcu_dereference_protected(
363 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
364 lockdep_is_held(&nf_ct_proto_mutex
)
366 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
367 &nf_conntrack_l4proto_generic
);
368 nf_ct_l4proto_unregister_sysctl(l4proto
);
369 mutex_unlock(&nf_ct_proto_mutex
);
373 /* Remove all contrack entries for this protocol */
376 nf_ct_iterate_cleanup(net
, kill_l4proto
, l4proto
);
379 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister
);
381 int nf_conntrack_proto_init(void)
386 err
= nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic
);
390 for (i
= 0; i
< AF_MAX
; i
++)
391 rcu_assign_pointer(nf_ct_l3protos
[i
],
392 &nf_conntrack_l3proto_generic
);
396 void nf_conntrack_proto_fini(void)
400 nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic
);
402 /* free l3proto protocol tables */
403 for (i
= 0; i
< PF_MAX
; i
++)
404 kfree(nf_ct_protos
[i
]);