2 * Copyright (c) 2010 Patrick McHardy <kaber@trash.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/module.h>
10 #include <linux/gfp.h>
11 #include <linux/skbuff.h>
12 #include <linux/netfilter_ipv4/ip_tables.h>
13 #include <linux/netfilter_ipv6/ip6_tables.h>
14 #include <linux/netfilter/x_tables.h>
15 #include <linux/netfilter/xt_CT.h>
16 #include <net/netfilter/nf_conntrack.h>
17 #include <net/netfilter/nf_conntrack_l4proto.h>
18 #include <net/netfilter/nf_conntrack_helper.h>
19 #include <net/netfilter/nf_conntrack_ecache.h>
20 #include <net/netfilter/nf_conntrack_timeout.h>
21 #include <net/netfilter/nf_conntrack_zones.h>
23 static unsigned int xt_ct_target_v0(struct sk_buff
*skb
,
24 const struct xt_action_param
*par
)
26 const struct xt_ct_target_info
*info
= par
->targinfo
;
27 struct nf_conn
*ct
= info
->ct
;
29 /* Previously seen (loopback)? Ignore. */
30 if (skb
->nfct
!= NULL
)
33 atomic_inc(&ct
->ct_general
.use
);
34 skb
->nfct
= &ct
->ct_general
;
35 skb
->nfctinfo
= IP_CT_NEW
;
40 static unsigned int xt_ct_target_v1(struct sk_buff
*skb
,
41 const struct xt_action_param
*par
)
43 const struct xt_ct_target_info_v1
*info
= par
->targinfo
;
44 struct nf_conn
*ct
= info
->ct
;
46 /* Previously seen (loopback)? Ignore. */
47 if (skb
->nfct
!= NULL
)
50 atomic_inc(&ct
->ct_general
.use
);
51 skb
->nfct
= &ct
->ct_general
;
52 skb
->nfctinfo
= IP_CT_NEW
;
57 static u8
xt_ct_find_proto(const struct xt_tgchk_param
*par
)
59 if (par
->family
== NFPROTO_IPV4
) {
60 const struct ipt_entry
*e
= par
->entryinfo
;
62 if (e
->ip
.invflags
& IPT_INV_PROTO
)
65 } else if (par
->family
== NFPROTO_IPV6
) {
66 const struct ip6t_entry
*e
= par
->entryinfo
;
68 if (e
->ipv6
.invflags
& IP6T_INV_PROTO
)
75 static int xt_ct_tg_check_v0(const struct xt_tgchk_param
*par
)
77 struct xt_ct_target_info
*info
= par
->targinfo
;
78 struct nf_conntrack_tuple t
;
79 struct nf_conn_help
*help
;
84 if (info
->flags
& ~XT_CT_NOTRACK
)
87 if (info
->flags
& XT_CT_NOTRACK
) {
88 ct
= nf_ct_untracked_get();
89 atomic_inc(&ct
->ct_general
.use
);
93 #ifndef CONFIG_NF_CONNTRACK_ZONES
98 ret
= nf_ct_l3proto_try_module_get(par
->family
);
102 memset(&t
, 0, sizeof(t
));
103 ct
= nf_conntrack_alloc(par
->net
, info
->zone
, &t
, &t
, GFP_KERNEL
);
109 if ((info
->ct_events
|| info
->exp_events
) &&
110 !nf_ct_ecache_ext_add(ct
, info
->ct_events
, info
->exp_events
,
114 if (info
->helper
[0]) {
115 struct nf_conntrack_helper
*helper
;
118 proto
= xt_ct_find_proto(par
);
120 pr_info("You must specify a L4 protocol, "
121 "and not use inversions on it.\n");
126 helper
= nf_conntrack_helper_try_module_get(info
->helper
,
129 if (helper
== NULL
) {
130 pr_info("No such helper \"%s\"\n", info
->helper
);
135 help
= nf_ct_helper_ext_add(ct
, helper
, GFP_KERNEL
);
139 help
->helper
= helper
;
142 __set_bit(IPS_TEMPLATE_BIT
, &ct
->status
);
143 __set_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
149 nf_conntrack_free(ct
);
151 nf_ct_l3proto_module_put(par
->family
);
156 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
157 static void __xt_ct_tg_timeout_put(struct ctnl_timeout
*timeout
)
159 typeof(nf_ct_timeout_put_hook
) timeout_put
;
161 timeout_put
= rcu_dereference(nf_ct_timeout_put_hook
);
163 timeout_put(timeout
);
167 static int xt_ct_tg_check_v1(const struct xt_tgchk_param
*par
)
169 struct xt_ct_target_info_v1
*info
= par
->targinfo
;
170 struct nf_conntrack_tuple t
;
171 struct nf_conn_help
*help
;
175 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
176 struct ctnl_timeout
*timeout
;
178 if (info
->flags
& ~XT_CT_NOTRACK
)
181 if (info
->flags
& XT_CT_NOTRACK
) {
182 ct
= nf_ct_untracked_get();
183 atomic_inc(&ct
->ct_general
.use
);
187 #ifndef CONFIG_NF_CONNTRACK_ZONES
192 ret
= nf_ct_l3proto_try_module_get(par
->family
);
196 memset(&t
, 0, sizeof(t
));
197 ct
= nf_conntrack_alloc(par
->net
, info
->zone
, &t
, &t
, GFP_KERNEL
);
203 if ((info
->ct_events
|| info
->exp_events
) &&
204 !nf_ct_ecache_ext_add(ct
, info
->ct_events
, info
->exp_events
,
208 if (info
->helper
[0]) {
209 struct nf_conntrack_helper
*helper
;
212 proto
= xt_ct_find_proto(par
);
214 pr_info("You must specify a L4 protocol, "
215 "and not use inversions on it.\n");
220 helper
= nf_conntrack_helper_try_module_get(info
->helper
,
223 if (helper
== NULL
) {
224 pr_info("No such helper \"%s\"\n", info
->helper
);
229 help
= nf_ct_helper_ext_add(ct
, helper
, GFP_KERNEL
);
233 help
->helper
= helper
;
236 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
237 if (info
->timeout
[0]) {
238 typeof(nf_ct_timeout_find_get_hook
) timeout_find_get
;
239 struct nf_conn_timeout
*timeout_ext
;
243 rcu_dereference(nf_ct_timeout_find_get_hook
);
245 if (timeout_find_get
) {
246 const struct ipt_entry
*e
= par
->entryinfo
;
247 struct nf_conntrack_l4proto
*l4proto
;
249 if (e
->ip
.invflags
& IPT_INV_PROTO
) {
251 pr_info("You cannot use inversion on "
255 timeout
= timeout_find_get(info
->timeout
);
256 if (timeout
== NULL
) {
258 pr_info("No such timeout policy \"%s\"\n",
262 if (timeout
->l3num
!= par
->family
) {
264 pr_info("Timeout policy `%s' can only be "
265 "used by L3 protocol number %d\n",
266 info
->timeout
, timeout
->l3num
);
269 /* Make sure the timeout policy matches any existing
270 * protocol tracker, otherwise default to generic.
272 l4proto
= __nf_ct_l4proto_find(par
->family
,
274 if (timeout
->l4proto
->l4proto
!= l4proto
->l4proto
) {
276 pr_info("Timeout policy `%s' can only be "
277 "used by L4 protocol number %d\n",
279 timeout
->l4proto
->l4proto
);
282 timeout_ext
= nf_ct_timeout_ext_add(ct
, timeout
,
284 if (timeout_ext
== NULL
) {
290 pr_info("Timeout policy base is empty\n");
297 __set_bit(IPS_TEMPLATE_BIT
, &ct
->status
);
298 __set_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
303 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
305 __xt_ct_tg_timeout_put(timeout
);
310 nf_conntrack_free(ct
);
312 nf_ct_l3proto_module_put(par
->family
);
317 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param
*par
)
319 struct xt_ct_target_info
*info
= par
->targinfo
;
320 struct nf_conn
*ct
= info
->ct
;
321 struct nf_conn_help
*help
;
323 if (!nf_ct_is_untracked(ct
)) {
324 help
= nfct_help(ct
);
326 module_put(help
->helper
->me
);
328 nf_ct_l3proto_module_put(par
->family
);
333 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param
*par
)
335 struct xt_ct_target_info_v1
*info
= par
->targinfo
;
336 struct nf_conn
*ct
= info
->ct
;
337 struct nf_conn_help
*help
;
338 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
339 struct nf_conn_timeout
*timeout_ext
;
340 typeof(nf_ct_timeout_put_hook
) timeout_put
;
342 if (!nf_ct_is_untracked(ct
)) {
343 help
= nfct_help(ct
);
345 module_put(help
->helper
->me
);
347 nf_ct_l3proto_module_put(par
->family
);
349 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
351 timeout_put
= rcu_dereference(nf_ct_timeout_put_hook
);
354 timeout_ext
= nf_ct_timeout_find(ct
);
356 timeout_put(timeout_ext
->timeout
);
364 static struct xt_target xt_ct_tg_reg
[] __read_mostly
= {
367 .family
= NFPROTO_UNSPEC
,
368 .targetsize
= sizeof(struct xt_ct_target_info
),
369 .checkentry
= xt_ct_tg_check_v0
,
370 .destroy
= xt_ct_tg_destroy_v0
,
371 .target
= xt_ct_target_v0
,
377 .family
= NFPROTO_UNSPEC
,
379 .targetsize
= sizeof(struct xt_ct_target_info_v1
),
380 .checkentry
= xt_ct_tg_check_v1
,
381 .destroy
= xt_ct_tg_destroy_v1
,
382 .target
= xt_ct_target_v1
,
388 static int __init
xt_ct_tg_init(void)
390 return xt_register_targets(xt_ct_tg_reg
, ARRAY_SIZE(xt_ct_tg_reg
));
393 static void __exit
xt_ct_tg_exit(void)
395 xt_unregister_targets(xt_ct_tg_reg
, ARRAY_SIZE(xt_ct_tg_reg
));
398 module_init(xt_ct_tg_init
);
399 module_exit(xt_ct_tg_exit
);
401 MODULE_LICENSE("GPL");
402 MODULE_DESCRIPTION("Xtables: connection tracking target");
403 MODULE_ALIAS("ipt_CT");
404 MODULE_ALIAS("ip6t_CT");