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
);
95 void nf_ct_l3proto_put(struct nf_conntrack_l3proto
*p
)
99 EXPORT_SYMBOL_GPL(nf_ct_l3proto_put
);
102 nf_ct_l3proto_try_module_get(unsigned short l3proto
)
105 struct nf_conntrack_l3proto
*p
;
107 retry
: p
= nf_ct_l3proto_find_get(l3proto
);
108 if (p
== &nf_conntrack_l3proto_generic
) {
109 ret
= request_module("nf_conntrack-%d", l3proto
);
118 EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get
);
120 void nf_ct_l3proto_module_put(unsigned short l3proto
)
122 struct nf_conntrack_l3proto
*p
;
124 /* rcu_read_lock not necessary since the caller holds a reference, but
125 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
128 p
= __nf_ct_l3proto_find(l3proto
);
132 EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put
);
134 struct nf_conntrack_l4proto
*
135 nf_ct_l4proto_find_get(u_int16_t l3num
, u_int8_t l4num
)
137 struct nf_conntrack_l4proto
*p
;
140 p
= __nf_ct_l4proto_find(l3num
, l4num
);
141 if (!try_module_get(p
->me
))
142 p
= &nf_conntrack_l4proto_generic
;
147 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get
);
149 void nf_ct_l4proto_put(struct nf_conntrack_l4proto
*p
)
153 EXPORT_SYMBOL_GPL(nf_ct_l4proto_put
);
155 static int kill_l3proto(struct nf_conn
*i
, void *data
)
157 return nf_ct_l3num(i
) == ((struct nf_conntrack_l3proto
*)data
)->l3proto
;
160 static int kill_l4proto(struct nf_conn
*i
, void *data
)
162 struct nf_conntrack_l4proto
*l4proto
;
163 l4proto
= (struct nf_conntrack_l4proto
*)data
;
164 return nf_ct_protonum(i
) == l4proto
->l4proto
&&
165 nf_ct_l3num(i
) == l4proto
->l3proto
;
168 static struct nf_ip_net
*nf_ct_l3proto_net(struct net
*net
,
169 struct nf_conntrack_l3proto
*l3proto
)
171 if (l3proto
->l3proto
== PF_INET
)
172 return &net
->ct
.nf_ct_proto
;
177 static int nf_ct_l3proto_register_sysctl(struct net
*net
,
178 struct nf_conntrack_l3proto
*l3proto
)
181 struct nf_ip_net
*in
= nf_ct_l3proto_net(net
, l3proto
);
182 /* nf_conntrack_l3proto_ipv6 doesn't support sysctl */
186 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
187 if (in
->ctl_table
!= NULL
) {
188 err
= nf_ct_register_sysctl(net
,
189 &in
->ctl_table_header
,
190 l3proto
->ctl_table_path
,
193 kfree(in
->ctl_table
);
194 in
->ctl_table
= NULL
;
201 static void nf_ct_l3proto_unregister_sysctl(struct net
*net
,
202 struct nf_conntrack_l3proto
*l3proto
)
204 struct nf_ip_net
*in
= nf_ct_l3proto_net(net
, l3proto
);
208 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
209 if (in
->ctl_table_header
!= NULL
)
210 nf_ct_unregister_sysctl(&in
->ctl_table_header
,
216 int nf_ct_l3proto_register(struct nf_conntrack_l3proto
*proto
)
219 struct nf_conntrack_l3proto
*old
;
221 if (proto
->l3proto
>= AF_MAX
)
224 if (proto
->tuple_to_nlattr
&& !proto
->nlattr_tuple_size
)
227 mutex_lock(&nf_ct_proto_mutex
);
228 old
= rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
229 lockdep_is_held(&nf_ct_proto_mutex
));
230 if (old
!= &nf_conntrack_l3proto_generic
) {
235 if (proto
->nlattr_tuple_size
)
236 proto
->nla_size
= 3 * proto
->nlattr_tuple_size();
238 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
], proto
);
241 mutex_unlock(&nf_ct_proto_mutex
);
245 EXPORT_SYMBOL_GPL(nf_ct_l3proto_register
);
247 int nf_ct_l3proto_pernet_register(struct net
*net
,
248 struct nf_conntrack_l3proto
*proto
)
252 if (proto
->init_net
) {
253 ret
= proto
->init_net(net
);
258 return nf_ct_l3proto_register_sysctl(net
, proto
);
260 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register
);
262 void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto
*proto
)
264 BUG_ON(proto
->l3proto
>= AF_MAX
);
266 mutex_lock(&nf_ct_proto_mutex
);
267 BUG_ON(rcu_dereference_protected(nf_ct_l3protos
[proto
->l3proto
],
268 lockdep_is_held(&nf_ct_proto_mutex
)
270 rcu_assign_pointer(nf_ct_l3protos
[proto
->l3proto
],
271 &nf_conntrack_l3proto_generic
);
272 mutex_unlock(&nf_ct_proto_mutex
);
276 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister
);
278 void nf_ct_l3proto_pernet_unregister(struct net
*net
,
279 struct nf_conntrack_l3proto
*proto
)
281 nf_ct_l3proto_unregister_sysctl(net
, proto
);
283 /* Remove all contrack entries for this protocol */
284 nf_ct_iterate_cleanup(net
, kill_l3proto
, proto
);
286 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister
);
288 static struct nf_proto_net
*nf_ct_l4proto_net(struct net
*net
,
289 struct nf_conntrack_l4proto
*l4proto
)
291 if (l4proto
->get_net_proto
) {
292 /* statically built-in protocols use static per-net */
293 return l4proto
->get_net_proto(net
);
294 } else if (l4proto
->net_id
) {
295 /* ... and loadable protocols use dynamic per-net */
296 return net_generic(net
, *l4proto
->net_id
);
302 int nf_ct_l4proto_register_sysctl(struct net
*net
,
303 struct nf_proto_net
*pn
,
304 struct nf_conntrack_l4proto
*l4proto
)
309 if (pn
->ctl_table
!= NULL
) {
310 err
= nf_ct_register_sysctl(net
,
311 &pn
->ctl_table_header
,
316 kfree(pn
->ctl_table
);
317 pn
->ctl_table
= NULL
;
321 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
322 if (l4proto
->l3proto
!= AF_INET6
&& pn
->ctl_compat_table
!= NULL
) {
324 nf_ct_kfree_compat_sysctl_table(pn
);
327 err
= nf_ct_register_sysctl(net
,
328 &pn
->ctl_compat_header
,
329 "net/ipv4/netfilter",
330 pn
->ctl_compat_table
);
334 nf_ct_kfree_compat_sysctl_table(pn
);
335 nf_ct_unregister_sysctl(&pn
->ctl_table_header
,
340 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
341 #endif /* CONFIG_SYSCTL */
346 void nf_ct_l4proto_unregister_sysctl(struct net
*net
,
347 struct nf_proto_net
*pn
,
348 struct nf_conntrack_l4proto
*l4proto
)
351 if (pn
->ctl_table_header
!= NULL
)
352 nf_ct_unregister_sysctl(&pn
->ctl_table_header
,
356 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
357 if (l4proto
->l3proto
!= AF_INET6
&& pn
->ctl_compat_header
!= NULL
)
358 nf_ct_unregister_sysctl(&pn
->ctl_compat_header
,
359 &pn
->ctl_compat_table
,
361 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
362 #endif /* CONFIG_SYSCTL */
365 /* FIXME: Allow NULL functions and sub in pointers to generic for
367 int nf_ct_l4proto_register(struct nf_conntrack_l4proto
*l4proto
)
371 if (l4proto
->l3proto
>= PF_MAX
)
374 if ((l4proto
->to_nlattr
&& !l4proto
->nlattr_size
)
375 || (l4proto
->tuple_to_nlattr
&& !l4proto
->nlattr_tuple_size
))
378 mutex_lock(&nf_ct_proto_mutex
);
379 if (!nf_ct_protos
[l4proto
->l3proto
]) {
380 /* l3proto may be loaded latter. */
381 struct nf_conntrack_l4proto __rcu
**proto_array
;
384 proto_array
= kmalloc(MAX_NF_CT_PROTO
*
385 sizeof(struct nf_conntrack_l4proto
*),
387 if (proto_array
== NULL
) {
392 for (i
= 0; i
< MAX_NF_CT_PROTO
; i
++)
393 RCU_INIT_POINTER(proto_array
[i
], &nf_conntrack_l4proto_generic
);
395 /* Before making proto_array visible to lockless readers,
396 * we must make sure its content is committed to memory.
400 nf_ct_protos
[l4proto
->l3proto
] = proto_array
;
401 } else if (rcu_dereference_protected(
402 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
403 lockdep_is_held(&nf_ct_proto_mutex
)
404 ) != &nf_conntrack_l4proto_generic
) {
409 l4proto
->nla_size
= 0;
410 if (l4proto
->nlattr_size
)
411 l4proto
->nla_size
+= l4proto
->nlattr_size();
412 if (l4proto
->nlattr_tuple_size
)
413 l4proto
->nla_size
+= 3 * l4proto
->nlattr_tuple_size();
415 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
418 mutex_unlock(&nf_ct_proto_mutex
);
421 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register
);
423 int nf_ct_l4proto_pernet_register(struct net
*net
,
424 struct nf_conntrack_l4proto
*l4proto
)
427 struct nf_proto_net
*pn
= NULL
;
429 if (l4proto
->init_net
) {
430 ret
= l4proto
->init_net(net
, l4proto
->l3proto
);
435 pn
= nf_ct_l4proto_net(net
, l4proto
);
439 ret
= nf_ct_l4proto_register_sysctl(net
, pn
, l4proto
);
447 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register
);
449 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto
*l4proto
)
451 BUG_ON(l4proto
->l3proto
>= PF_MAX
);
453 mutex_lock(&nf_ct_proto_mutex
);
454 BUG_ON(rcu_dereference_protected(
455 nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
456 lockdep_is_held(&nf_ct_proto_mutex
)
458 rcu_assign_pointer(nf_ct_protos
[l4proto
->l3proto
][l4proto
->l4proto
],
459 &nf_conntrack_l4proto_generic
);
460 mutex_unlock(&nf_ct_proto_mutex
);
464 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister
);
466 void nf_ct_l4proto_pernet_unregister(struct net
*net
,
467 struct nf_conntrack_l4proto
*l4proto
)
469 struct nf_proto_net
*pn
= NULL
;
471 pn
= nf_ct_l4proto_net(net
, l4proto
);
476 nf_ct_l4proto_unregister_sysctl(net
, pn
, l4proto
);
478 /* Remove all contrack entries for this protocol */
479 nf_ct_iterate_cleanup(net
, kill_l4proto
, l4proto
);
481 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister
);
483 int nf_conntrack_proto_pernet_init(struct net
*net
)
486 struct nf_proto_net
*pn
= nf_ct_l4proto_net(net
,
487 &nf_conntrack_l4proto_generic
);
489 err
= nf_conntrack_l4proto_generic
.init_net(net
,
490 nf_conntrack_l4proto_generic
.l3proto
);
493 err
= nf_ct_l4proto_register_sysctl(net
,
495 &nf_conntrack_l4proto_generic
);
503 void nf_conntrack_proto_pernet_fini(struct net
*net
)
505 struct nf_proto_net
*pn
= nf_ct_l4proto_net(net
,
506 &nf_conntrack_l4proto_generic
);
509 nf_ct_l4proto_unregister_sysctl(net
,
511 &nf_conntrack_l4proto_generic
);
514 int nf_conntrack_proto_init(void)
517 for (i
= 0; i
< AF_MAX
; i
++)
518 rcu_assign_pointer(nf_ct_l3protos
[i
],
519 &nf_conntrack_l3proto_generic
);
523 void nf_conntrack_proto_fini(void)
526 /* free l3proto protocol tables */
527 for (i
= 0; i
< PF_MAX
; i
++)
528 kfree(nf_ct_protos
[i
]);