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>
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 struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
32 struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
35 static DEFINE_MUTEX(nf_ct_proto_sysctl_mutex);
38 nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path,
39 struct ctl_table *table, unsigned int *users)
41 if (*header == NULL) {
42 *header = nf_register_sysctl_table(path, table);
52 nf_ct_unregister_sysctl(struct ctl_table_header **header,
53 struct ctl_table *table, unsigned int *users)
55 if (users != NULL && --*users > 0)
57 nf_unregister_sysctl_table(*header, table);
62 struct nf_conntrack_l4proto *
63 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
65 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
66 return &nf_conntrack_l4proto_generic;
68 return nf_ct_protos[l3proto][l4proto];
71 /* this is guaranteed to always return a valid protocol helper, since
72 * it falls back to generic_protocol */
73 struct nf_conntrack_l4proto *
74 nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto)
76 struct nf_conntrack_l4proto *p;
79 p = __nf_ct_l4proto_find(l3proto, l4proto);
80 if (!try_module_get(p->me))
81 p = &nf_conntrack_l4proto_generic;
87 void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
92 struct nf_conntrack_l3proto *
93 nf_ct_l3proto_find_get(u_int16_t l3proto)
95 struct nf_conntrack_l3proto *p;
98 p = __nf_ct_l3proto_find(l3proto);
99 if (!try_module_get(p->me))
100 p = &nf_conntrack_l3proto_generic;
106 void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
112 nf_ct_l3proto_try_module_get(unsigned short l3proto)
115 struct nf_conntrack_l3proto *p;
117 retry: p = nf_ct_l3proto_find_get(l3proto);
118 if (p == &nf_conntrack_l3proto_generic) {
119 ret = request_module("nf_conntrack-%d", l3proto);
129 void nf_ct_l3proto_module_put(unsigned short l3proto)
131 struct nf_conntrack_l3proto *p;
134 p = __nf_ct_l3proto_find(l3proto);
140 static int kill_l3proto(struct nf_conn *i, void *data)
142 return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
143 ((struct nf_conntrack_l3proto *)data)->l3proto);
146 static int kill_l4proto(struct nf_conn *i, void *data)
148 struct nf_conntrack_l4proto *l4proto;
149 l4proto = (struct nf_conntrack_l4proto *)data;
150 return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==
152 (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
156 static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
161 mutex_lock(&nf_ct_proto_sysctl_mutex);
162 if (l3proto->ctl_table != NULL) {
163 err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
164 l3proto->ctl_table_path,
165 l3proto->ctl_table, NULL);
167 mutex_unlock(&nf_ct_proto_sysctl_mutex);
172 static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
175 mutex_lock(&nf_ct_proto_sysctl_mutex);
176 if (l3proto->ctl_table_header != NULL)
177 nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
178 l3proto->ctl_table, NULL);
179 mutex_unlock(&nf_ct_proto_sysctl_mutex);
183 int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
187 if (proto->l3proto >= AF_MAX) {
192 write_lock_bh(&nf_conntrack_lock);
193 if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
197 nf_ct_l3protos[proto->l3proto] = proto;
198 write_unlock_bh(&nf_conntrack_lock);
200 ret = nf_ct_l3proto_register_sysctl(proto);
202 nf_conntrack_l3proto_unregister(proto);
206 write_unlock_bh(&nf_conntrack_lock);
211 int nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
215 if (proto->l3proto >= AF_MAX) {
220 write_lock_bh(&nf_conntrack_lock);
221 if (nf_ct_l3protos[proto->l3proto] != proto) {
222 write_unlock_bh(&nf_conntrack_lock);
227 nf_ct_l3protos[proto->l3proto] = &nf_conntrack_l3proto_generic;
228 write_unlock_bh(&nf_conntrack_lock);
230 nf_ct_l3proto_unregister_sysctl(proto);
232 /* Somebody could be still looking at the proto in bh. */
235 /* Remove all contrack entries for this protocol */
236 nf_ct_iterate_cleanup(kill_l3proto, proto);
242 static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
247 mutex_lock(&nf_ct_proto_sysctl_mutex);
248 if (l4proto->ctl_table != NULL) {
249 err = nf_ct_register_sysctl(l4proto->ctl_table_header,
250 nf_net_netfilter_sysctl_path,
252 l4proto->ctl_table_users);
254 mutex_unlock(&nf_ct_proto_sysctl_mutex);
255 #endif /* CONFIG_SYSCTL */
259 static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
262 mutex_lock(&nf_ct_proto_sysctl_mutex);
263 if (l4proto->ctl_table_header != NULL &&
264 *l4proto->ctl_table_header != NULL)
265 nf_ct_unregister_sysctl(l4proto->ctl_table_header,
267 l4proto->ctl_table_users);
268 mutex_unlock(&nf_ct_proto_sysctl_mutex);
269 #endif /* CONFIG_SYSCTL */
272 /* FIXME: Allow NULL functions and sub in pointers to generic for
274 int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
278 if (l4proto->l3proto >= PF_MAX) {
283 if (l4proto == &nf_conntrack_l4proto_generic)
284 return nf_ct_l4proto_register_sysctl(l4proto);
287 write_lock_bh(&nf_conntrack_lock);
288 if (nf_ct_protos[l4proto->l3proto]) {
289 if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
290 != &nf_conntrack_l4proto_generic) {
295 /* l3proto may be loaded latter. */
296 struct nf_conntrack_l4proto **proto_array;
299 write_unlock_bh(&nf_conntrack_lock);
301 proto_array = (struct nf_conntrack_l4proto **)
302 kmalloc(MAX_NF_CT_PROTO *
303 sizeof(struct nf_conntrack_l4proto *),
305 if (proto_array == NULL) {
309 for (i = 0; i < MAX_NF_CT_PROTO; i++)
310 proto_array[i] = &nf_conntrack_l4proto_generic;
312 write_lock_bh(&nf_conntrack_lock);
313 if (nf_ct_protos[l4proto->l3proto]) {
314 /* bad timing, but no problem */
315 write_unlock_bh(&nf_conntrack_lock);
318 nf_ct_protos[l4proto->l3proto] = proto_array;
319 write_unlock_bh(&nf_conntrack_lock);
323 * Just once because array is never freed until unloading
329 nf_ct_protos[l4proto->l3proto][l4proto->l4proto] = l4proto;
330 write_unlock_bh(&nf_conntrack_lock);
332 ret = nf_ct_l4proto_register_sysctl(l4proto);
334 nf_conntrack_l4proto_unregister(l4proto);
338 write_unlock_bh(&nf_conntrack_lock);
343 int nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
347 if (l4proto->l3proto >= PF_MAX) {
352 if (l4proto == &nf_conntrack_l4proto_generic) {
353 nf_ct_l4proto_unregister_sysctl(l4proto);
357 write_lock_bh(&nf_conntrack_lock);
358 if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
360 write_unlock_bh(&nf_conntrack_lock);
364 nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
365 = &nf_conntrack_l4proto_generic;
366 write_unlock_bh(&nf_conntrack_lock);
368 nf_ct_l4proto_unregister_sysctl(l4proto);
370 /* Somebody could be still looking at the proto in bh. */
373 /* Remove all contrack entries for this protocol */
374 nf_ct_iterate_cleanup(kill_l4proto, l4proto);