]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - net/netfilter/xt_helper.c
1 /* iptables module to match on related connections */
3 * (C) 2001 Martin Josefsson <gandalf@wlug.westbo.se>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/netfilter.h>
13 #include <net/netfilter/nf_conntrack.h>
14 #include <net/netfilter/nf_conntrack_core.h>
15 #include <net/netfilter/nf_conntrack_helper.h>
16 #include <linux/netfilter/x_tables.h>
17 #include <linux/netfilter/xt_helper.h>
19 MODULE_LICENSE("GPL");
20 MODULE_AUTHOR("Martin Josefsson <gandalf@netfilter.org>");
21 MODULE_DESCRIPTION("iptables helper match module");
22 MODULE_ALIAS("ipt_helper");
23 MODULE_ALIAS("ip6t_helper");
27 match(const struct sk_buff
*skb
,
28 const struct net_device
*in
,
29 const struct net_device
*out
,
30 const struct xt_match
*match
,
31 const void *matchinfo
,
36 const struct xt_helper_info
*info
= matchinfo
;
37 const struct nf_conn
*ct
;
38 const struct nf_conn_help
*master_help
;
39 const struct nf_conntrack_helper
*helper
;
40 enum ip_conntrack_info ctinfo
;
41 bool ret
= info
->invert
;
43 ct
= nf_ct_get(skb
, &ctinfo
);
44 if (!ct
|| !ct
->master
)
47 master_help
= nfct_help(ct
->master
);
51 /* rcu_read_lock()ed by nf_hook_slow */
52 helper
= rcu_dereference(master_help
->helper
);
56 if (info
->name
[0] == '\0')
59 ret
^= !strncmp(master_help
->helper
->name
, info
->name
,
60 strlen(master_help
->helper
->name
));
64 static bool check(const char *tablename
,
66 const struct xt_match
*match
,
68 unsigned int hook_mask
)
70 struct xt_helper_info
*info
= matchinfo
;
72 if (nf_ct_l3proto_try_module_get(match
->family
) < 0) {
73 printk(KERN_WARNING
"can't load conntrack support for "
74 "proto=%d\n", match
->family
);
77 info
->name
[29] = '\0';
82 destroy(const struct xt_match
*match
, void *matchinfo
)
84 nf_ct_l3proto_module_put(match
->family
);
87 static struct xt_match xt_helper_match
[] __read_mostly
= {
94 .matchsize
= sizeof(struct xt_helper_info
),
103 .matchsize
= sizeof(struct xt_helper_info
),
108 static int __init
xt_helper_init(void)
110 return xt_register_matches(xt_helper_match
,
111 ARRAY_SIZE(xt_helper_match
));
114 static void __exit
xt_helper_fini(void)
116 xt_unregister_matches(xt_helper_match
, ARRAY_SIZE(xt_helper_match
));
119 module_init(xt_helper_init
);
120 module_exit(xt_helper_fini
);