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>
6 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/types.h>
14 #include <linux/netfilter.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/mutex.h>
18 #include <linux/vmalloc.h>
19 #include <linux/stddef.h>
20 #include <linux/err.h>
21 #include <linux/percpu.h>
22 #include <linux/notifier.h>
23 #include <linux/kernel.h>
24 #include <linux/netdevice.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 net
*net
,
40 struct ctl_table_header
**header
,
42 struct ctl_table
*table
)
44 if (*header
== NULL
) {
45 *header
= register_net_sysctl(net
, path
, table
);
54 nf_ct_unregister_sysctl(struct ctl_table_header
**header
,
55 struct ctl_table
**table
,
61 unregister_net_sysctl_table(*header
);
68 struct nf_conntrack_l4proto
*
69 __nf_ct_l4proto_find(u_int16_t l3proto
, u_int8_t l4proto
)
71 if (unlikely(l3proto
>= AF_MAX
|| nf_ct_protos
[l3proto
] == NULL
))
72 return &nf_conntrack_l4proto_generic
;
74 return rcu_dereference(nf_ct_protos
[l3proto
][l4proto
]);
76 EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find
);
78 /* this is guaranteed to always return a valid protocol helper, since
79 * it falls back to generic_protocol */
80 struct nf_conntrack_l3proto
*
81 nf_ct_l3proto_find_get(u_int16_t l3proto
)
83 struct nf_conntrack_l3proto
*p
;
86 p
= __nf_ct_l3proto_find(l3proto
);
87 if (!try_module_get(p
->me
))
88 p
= &nf_conntrack_l3proto_generic
;
93 EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get
);
96 nf_ct_l3proto_try_module_get(unsigned short l3proto
)
99 struct nf_conntrack_l3proto
*p
;
101 retry
: p
= nf_ct_l3proto_find_get(l3proto
);
102 if (p
== &nf_conntrack_l3proto_generic
) {
103 ret
= request_module("nf_conntrack-%d", l3proto
);
112 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get
);
114 void nf_ct_l3proto_module_put(unsigned short l3proto
)
116 struct nf_conntrack_l3proto
*p
;
118 /* rcu_read_lock not necessary since the caller holds a reference, but
119 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
122 p
= __nf_ct_l3proto_find(l3proto
);
126 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put
);
128 struct nf_conntrack_l4proto
*
129 nf_ct_l4proto_find_get(u_int16_t l3num
, u_int8_t l4num
)
131 struct nf_conntrack_l4proto
*p
;
134 p
= __nf_ct_l4proto_find(l3num
, l4num
);
135 if (!try_module_get(p
->me
))
136 p
= &nf_conntrack_l4proto_generic
;
141 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get
);
143 void nf_ct_l4proto_put(struct nf_conntrack_l4proto
*p
)
147 EXPORT_SYMBOL_GPL(nf_ct_l4proto_put
);
149 static int kill_l3proto(struct nf_conn
*i
, void *data
)
151 return nf_ct_l3num(i
) == ((struct nf_conntrack_l3proto
*)data
)->l3proto
;
154 static int kill_l4proto(struct nf_conn
*i
, void *data
)
156 struct nf_conntrack_l4proto
*l4proto
;
157 l4proto
= (struct nf_conntrack_l4proto
*)data
;
158 return nf_ct_protonum(i
) == l4proto
->l4proto
&&
159 nf_ct_l3num(i
) == l4proto
->l3proto
;
162 int nf_ct_l3proto_register(struct nf_conntrack_l3proto
*proto
)
165 struct nf_conntrack_l3proto
*old
;
167 if (proto
->l3proto
>= AF_MAX
)
170 if (proto
->tuple_to_nlattr
&& !proto
->nlattr_tuple_size
)
173 mutex_lock(&nf_ct_proto_mutex
);
174 old
= rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
175 lockdep_is_held(&nf_ct_proto_mutex
));
176 if (old
!= &nf_conntrack_l3proto_generic
) {
181 if (proto
->nlattr_tuple_size
)
182 proto
->nla_size
= 3 * proto
->nlattr_tuple_size();
184 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
], proto
);
187 mutex_unlock(&nf_ct_proto_mutex
);
191 EXPORT_SYMBOL_GPL(nf_ct_l3proto_register
);
193 int nf_ct_l3proto_pernet_register(struct net
*net
,
194 struct nf_conntrack_l3proto
*proto
)
198 if (proto
->init_net
) {
199 ret
= proto
->init_net(net
);
206 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register
);
208 void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto
*proto
)
210 BUG_ON(proto
->l3proto
>= AF_MAX
);
212 mutex_lock(&nf_ct_proto_mutex
);
213 BUG_ON(rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
214 lockdep_is_held(&nf_ct_proto_mutex
)
216 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
],
217 &nf_conntrack_l3proto_generic
);
218 mutex_unlock(&nf_ct_proto_mutex
);
222 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister
);
224 void nf_ct_l3proto_pernet_unregister(struct net
*net
,
225 struct nf_conntrack_l3proto
*proto
)
227 /* Remove all contrack entries for this protocol */
228 nf_ct_iterate_cleanup(net
, kill_l3proto
, proto
, 0, 0);
230 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister
);
232 static struct nf_proto_net
*nf_ct_l4proto_net(struct net
*net
,
233 struct nf_conntrack_l4proto
*l4proto
)
235 if (l4proto
->get_net_proto
) {
236 /* statically built-in protocols use static per-net */
237 return l4proto
->get_net_proto(net
);
238 } else if (l4proto
->net_id
) {
239 /* ... and loadable protocols use dynamic per-net */
240 return net_generic(net
, *l4proto
->net_id
);
246 int nf_ct_l4proto_register_sysctl(struct net
*net
,
247 struct nf_proto_net
*pn
,
248 struct nf_conntrack_l4proto
*l4proto
)
253 if (pn
->ctl_table
!= NULL
) {
254 err
= nf_ct_register_sysctl(net
,
255 &pn
->ctl_table_header
,
260 kfree(pn
->ctl_table
);
261 pn
->ctl_table
= NULL
;
265 #endif /* CONFIG_SYSCTL */
270 void nf_ct_l4proto_unregister_sysctl(struct net
*net
,
271 struct nf_proto_net
*pn
,
272 struct nf_conntrack_l4proto
*l4proto
)
275 if (pn
->ctl_table_header
!= NULL
)
276 nf_ct_unregister_sysctl(&pn
->ctl_table_header
,
279 #endif /* CONFIG_SYSCTL */
282 /* FIXME: Allow NULL functions and sub in pointers to generic for
284 int nf_ct_l4proto_register(struct nf_conntrack_l4proto
*l4proto
)
288 if (l4proto
->l3proto
>= PF_MAX
)
291 if ((l4proto
->to_nlattr
&& !l4proto
->nlattr_size
)
292 || (l4proto
->tuple_to_nlattr
&& !l4proto
->nlattr_tuple_size
))
295 mutex_lock(&nf_ct_proto_mutex
);
296 if (!nf_ct_protos
[l4proto
->l3proto
]) {
297 /* l3proto may be loaded latter. */
298 struct nf_conntrack_l4proto __rcu
**proto_array
;
301 proto_array
= kmalloc(MAX_NF_CT_PROTO
*
302 sizeof(struct nf_conntrack_l4proto
*),
304 if (proto_array
== NULL
) {
309 for (i
= 0; i
< MAX_NF_CT_PROTO
; i
++)
310 RCU_INIT_POINTER(proto_array
[i
], &nf_conntrack_l4proto_generic
);
312 /* Before making proto_array visible to lockless readers,
313 * we must make sure its content is committed to memory.
317 nf_ct_protos
[l4proto
->l3proto
] = proto_array
;
318 } else if (rcu_dereference_protected(
319 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
320 lockdep_is_held(&nf_ct_proto_mutex
)
321 ) != &nf_conntrack_l4proto_generic
) {
326 l4proto
->nla_size
= 0;
327 if (l4proto
->nlattr_size
)
328 l4proto
->nla_size
+= l4proto
->nlattr_size();
329 if (l4proto
->nlattr_tuple_size
)
330 l4proto
->nla_size
+= 3 * l4proto
->nlattr_tuple_size();
332 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
335 mutex_unlock(&nf_ct_proto_mutex
);
338 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register
);
340 int nf_ct_l4proto_pernet_register(struct net
*net
,
341 struct nf_conntrack_l4proto
*l4proto
)
344 struct nf_proto_net
*pn
= NULL
;
346 if (l4proto
->init_net
) {
347 ret
= l4proto
->init_net(net
, l4proto
->l3proto
);
352 pn
= nf_ct_l4proto_net(net
, l4proto
);
356 ret
= nf_ct_l4proto_register_sysctl(net
, pn
, l4proto
);
364 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register
);
366 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto
*l4proto
)
368 BUG_ON(l4proto
->l3proto
>= PF_MAX
);
370 mutex_lock(&nf_ct_proto_mutex
);
371 BUG_ON(rcu_dereference_protected(
372 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
373 lockdep_is_held(&nf_ct_proto_mutex
)
375 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
376 &nf_conntrack_l4proto_generic
);
377 mutex_unlock(&nf_ct_proto_mutex
);
381 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister
);
383 void nf_ct_l4proto_pernet_unregister(struct net
*net
,
384 struct nf_conntrack_l4proto
*l4proto
)
386 struct nf_proto_net
*pn
= NULL
;
388 pn
= nf_ct_l4proto_net(net
, l4proto
);
393 nf_ct_l4proto_unregister_sysctl(net
, pn
, l4proto
);
395 /* Remove all contrack entries for this protocol */
396 nf_ct_iterate_cleanup(net
, kill_l4proto
, l4proto
, 0, 0);
398 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister
);
400 int nf_conntrack_proto_pernet_init(struct net
*net
)
403 struct nf_proto_net
*pn
= nf_ct_l4proto_net(net
,
404 &nf_conntrack_l4proto_generic
);
406 err
= nf_conntrack_l4proto_generic
.init_net(net
,
407 nf_conntrack_l4proto_generic
.l3proto
);
410 err
= nf_ct_l4proto_register_sysctl(net
,
412 &nf_conntrack_l4proto_generic
);
420 void nf_conntrack_proto_pernet_fini(struct net
*net
)
422 struct nf_proto_net
*pn
= nf_ct_l4proto_net(net
,
423 &nf_conntrack_l4proto_generic
);
426 nf_ct_l4proto_unregister_sysctl(net
,
428 &nf_conntrack_l4proto_generic
);
431 int nf_conntrack_proto_init(void)
434 for (i
= 0; i
< AF_MAX
; i
++)
435 rcu_assign_pointer(nf_ct_l3protos
[i
],
436 &nf_conntrack_l3proto_generic
);
440 void nf_conntrack_proto_fini(void)
443 /* free l3proto protocol tables */
444 for (i
= 0; i
< PF_MAX
; i
++)
445 kfree(nf_ct_protos
[i
]);