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 static struct nf_ip_net
*nf_ct_l3proto_net(struct net
*net
,
163 struct nf_conntrack_l3proto
*l3proto
)
165 if (l3proto
->l3proto
== PF_INET
)
166 return &net
->ct
.nf_ct_proto
;
171 static int nf_ct_l3proto_register_sysctl(struct net
*net
,
172 struct nf_conntrack_l3proto
*l3proto
)
175 struct nf_ip_net
*in
= nf_ct_l3proto_net(net
, l3proto
);
176 /* nf_conntrack_l3proto_ipv6 doesn't support sysctl */
180 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
181 if (in
->ctl_table
!= NULL
) {
182 err
= nf_ct_register_sysctl(net
,
183 &in
->ctl_table_header
,
184 l3proto
->ctl_table_path
,
187 kfree(in
->ctl_table
);
188 in
->ctl_table
= NULL
;
195 static void nf_ct_l3proto_unregister_sysctl(struct net
*net
,
196 struct nf_conntrack_l3proto
*l3proto
)
198 struct nf_ip_net
*in
= nf_ct_l3proto_net(net
, l3proto
);
202 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
203 if (in
->ctl_table_header
!= NULL
)
204 nf_ct_unregister_sysctl(&in
->ctl_table_header
,
210 int nf_ct_l3proto_register(struct nf_conntrack_l3proto
*proto
)
213 struct nf_conntrack_l3proto
*old
;
215 if (proto
->l3proto
>= AF_MAX
)
218 if (proto
->tuple_to_nlattr
&& !proto
->nlattr_tuple_size
)
221 mutex_lock(&nf_ct_proto_mutex
);
222 old
= rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
223 lockdep_is_held(&nf_ct_proto_mutex
));
224 if (old
!= &nf_conntrack_l3proto_generic
) {
229 if (proto
->nlattr_tuple_size
)
230 proto
->nla_size
= 3 * proto
->nlattr_tuple_size();
232 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
], proto
);
235 mutex_unlock(&nf_ct_proto_mutex
);
239 EXPORT_SYMBOL_GPL(nf_ct_l3proto_register
);
241 int nf_ct_l3proto_pernet_register(struct net
*net
,
242 struct nf_conntrack_l3proto
*proto
)
246 if (proto
->init_net
) {
247 ret
= proto
->init_net(net
);
252 return nf_ct_l3proto_register_sysctl(net
, proto
);
254 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register
);
256 void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto
*proto
)
258 BUG_ON(proto
->l3proto
>= AF_MAX
);
260 mutex_lock(&nf_ct_proto_mutex
);
261 BUG_ON(rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
262 lockdep_is_held(&nf_ct_proto_mutex
)
264 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
],
265 &nf_conntrack_l3proto_generic
);
266 mutex_unlock(&nf_ct_proto_mutex
);
270 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister
);
272 void nf_ct_l3proto_pernet_unregister(struct net
*net
,
273 struct nf_conntrack_l3proto
*proto
)
275 nf_ct_l3proto_unregister_sysctl(net
, proto
);
277 /* Remove all contrack entries for this protocol */
278 nf_ct_iterate_cleanup(net
, kill_l3proto
, proto
, 0, 0);
280 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister
);
282 static struct nf_proto_net
*nf_ct_l4proto_net(struct net
*net
,
283 struct nf_conntrack_l4proto
*l4proto
)
285 if (l4proto
->get_net_proto
) {
286 /* statically built-in protocols use static per-net */
287 return l4proto
->get_net_proto(net
);
288 } else if (l4proto
->net_id
) {
289 /* ... and loadable protocols use dynamic per-net */
290 return net_generic(net
, *l4proto
->net_id
);
296 int nf_ct_l4proto_register_sysctl(struct net
*net
,
297 struct nf_proto_net
*pn
,
298 struct nf_conntrack_l4proto
*l4proto
)
303 if (pn
->ctl_table
!= NULL
) {
304 err
= nf_ct_register_sysctl(net
,
305 &pn
->ctl_table_header
,
310 kfree(pn
->ctl_table
);
311 pn
->ctl_table
= NULL
;
315 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
316 if (l4proto
->l3proto
!= AF_INET6
&& pn
->ctl_compat_table
!= NULL
) {
318 nf_ct_kfree_compat_sysctl_table(pn
);
321 err
= nf_ct_register_sysctl(net
,
322 &pn
->ctl_compat_header
,
323 "net/ipv4/netfilter",
324 pn
->ctl_compat_table
);
328 nf_ct_kfree_compat_sysctl_table(pn
);
329 nf_ct_unregister_sysctl(&pn
->ctl_table_header
,
334 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
335 #endif /* CONFIG_SYSCTL */
340 void nf_ct_l4proto_unregister_sysctl(struct net
*net
,
341 struct nf_proto_net
*pn
,
342 struct nf_conntrack_l4proto
*l4proto
)
345 if (pn
->ctl_table_header
!= NULL
)
346 nf_ct_unregister_sysctl(&pn
->ctl_table_header
,
350 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
351 if (l4proto
->l3proto
!= AF_INET6
&& pn
->ctl_compat_header
!= NULL
)
352 nf_ct_unregister_sysctl(&pn
->ctl_compat_header
,
353 &pn
->ctl_compat_table
,
355 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
356 #endif /* CONFIG_SYSCTL */
359 /* FIXME: Allow NULL functions and sub in pointers to generic for
361 int nf_ct_l4proto_register(struct nf_conntrack_l4proto
*l4proto
)
365 if (l4proto
->l3proto
>= PF_MAX
)
368 if ((l4proto
->to_nlattr
&& !l4proto
->nlattr_size
)
369 || (l4proto
->tuple_to_nlattr
&& !l4proto
->nlattr_tuple_size
))
372 mutex_lock(&nf_ct_proto_mutex
);
373 if (!nf_ct_protos
[l4proto
->l3proto
]) {
374 /* l3proto may be loaded latter. */
375 struct nf_conntrack_l4proto __rcu
**proto_array
;
378 proto_array
= kmalloc(MAX_NF_CT_PROTO
*
379 sizeof(struct nf_conntrack_l4proto
*),
381 if (proto_array
== NULL
) {
386 for (i
= 0; i
< MAX_NF_CT_PROTO
; i
++)
387 RCU_INIT_POINTER(proto_array
[i
], &nf_conntrack_l4proto_generic
);
389 /* Before making proto_array visible to lockless readers,
390 * we must make sure its content is committed to memory.
394 nf_ct_protos
[l4proto
->l3proto
] = proto_array
;
395 } else if (rcu_dereference_protected(
396 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
397 lockdep_is_held(&nf_ct_proto_mutex
)
398 ) != &nf_conntrack_l4proto_generic
) {
403 l4proto
->nla_size
= 0;
404 if (l4proto
->nlattr_size
)
405 l4proto
->nla_size
+= l4proto
->nlattr_size();
406 if (l4proto
->nlattr_tuple_size
)
407 l4proto
->nla_size
+= 3 * l4proto
->nlattr_tuple_size();
409 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
412 mutex_unlock(&nf_ct_proto_mutex
);
415 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register
);
417 int nf_ct_l4proto_pernet_register(struct net
*net
,
418 struct nf_conntrack_l4proto
*l4proto
)
421 struct nf_proto_net
*pn
= NULL
;
423 if (l4proto
->init_net
) {
424 ret
= l4proto
->init_net(net
, l4proto
->l3proto
);
429 pn
= nf_ct_l4proto_net(net
, l4proto
);
433 ret
= nf_ct_l4proto_register_sysctl(net
, pn
, l4proto
);
441 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register
);
443 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto
*l4proto
)
445 BUG_ON(l4proto
->l3proto
>= PF_MAX
);
447 mutex_lock(&nf_ct_proto_mutex
);
448 BUG_ON(rcu_dereference_protected(
449 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
450 lockdep_is_held(&nf_ct_proto_mutex
)
452 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
453 &nf_conntrack_l4proto_generic
);
454 mutex_unlock(&nf_ct_proto_mutex
);
458 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister
);
460 void nf_ct_l4proto_pernet_unregister(struct net
*net
,
461 struct nf_conntrack_l4proto
*l4proto
)
463 struct nf_proto_net
*pn
= NULL
;
465 pn
= nf_ct_l4proto_net(net
, l4proto
);
470 nf_ct_l4proto_unregister_sysctl(net
, pn
, l4proto
);
472 /* Remove all contrack entries for this protocol */
473 nf_ct_iterate_cleanup(net
, kill_l4proto
, l4proto
, 0, 0);
475 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister
);
477 int nf_conntrack_proto_pernet_init(struct net
*net
)
480 struct nf_proto_net
*pn
= nf_ct_l4proto_net(net
,
481 &nf_conntrack_l4proto_generic
);
483 err
= nf_conntrack_l4proto_generic
.init_net(net
,
484 nf_conntrack_l4proto_generic
.l3proto
);
487 err
= nf_ct_l4proto_register_sysctl(net
,
489 &nf_conntrack_l4proto_generic
);
497 void nf_conntrack_proto_pernet_fini(struct net
*net
)
499 struct nf_proto_net
*pn
= nf_ct_l4proto_net(net
,
500 &nf_conntrack_l4proto_generic
);
503 nf_ct_l4proto_unregister_sysctl(net
,
505 &nf_conntrack_l4proto_generic
);
508 int nf_conntrack_proto_init(void)
511 for (i
= 0; i
< AF_MAX
; i
++)
512 rcu_assign_pointer(nf_ct_l3protos
[i
],
513 &nf_conntrack_l3proto_generic
);
517 void nf_conntrack_proto_fini(void)
520 /* free l3proto protocol tables */
521 for (i
= 0; i
< PF_MAX
; i
++)
522 kfree(nf_ct_protos
[i
]);