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Commit | Line | Data |
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1da177e4 LT |
1 | /* Kernel module to match connection tracking information. */ |
2 | ||
3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
2e4e6a17 | 4 | * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org> |
1da177e4 LT |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/skbuff.h> | |
587aa641 | 13 | #include <net/netfilter/nf_conntrack.h> |
2e4e6a17 HW |
14 | #include <linux/netfilter/x_tables.h> |
15 | #include <linux/netfilter/xt_state.h> | |
1da177e4 LT |
16 | |
17 | MODULE_LICENSE("GPL"); | |
18 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); | |
2e4e6a17 HW |
19 | MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module"); |
20 | MODULE_ALIAS("ipt_state"); | |
21 | MODULE_ALIAS("ip6t_state"); | |
1da177e4 | 22 | |
1d93a9cb | 23 | static bool |
62fc8051 | 24 | state_mt(const struct sk_buff *skb, struct xt_action_param *par) |
1da177e4 | 25 | { |
f7108a20 | 26 | const struct xt_state_info *sinfo = par->matchinfo; |
1da177e4 LT |
27 | enum ip_conntrack_info ctinfo; |
28 | unsigned int statebit; | |
29 | ||
9fb9cbb1 | 30 | if (nf_ct_is_untracked(skb)) |
2e4e6a17 | 31 | statebit = XT_STATE_UNTRACKED; |
587aa641 | 32 | else if (!nf_ct_get(skb, &ctinfo)) |
2e4e6a17 | 33 | statebit = XT_STATE_INVALID; |
1da177e4 | 34 | else |
2e4e6a17 | 35 | statebit = XT_STATE_BIT(ctinfo); |
1da177e4 LT |
36 | |
37 | return (sinfo->statemask & statebit); | |
38 | } | |
39 | ||
b0f38452 | 40 | static int state_mt_check(const struct xt_mtchk_param *par) |
b9f78f9f | 41 | { |
4a5a5c73 JE |
42 | int ret; |
43 | ||
44 | ret = nf_ct_l3proto_try_module_get(par->family); | |
f95c74e3 | 45 | if (ret < 0) |
8bee4bad JE |
46 | pr_info("cannot load conntrack support for proto=%u\n", |
47 | par->family); | |
f95c74e3 | 48 | return ret; |
b9f78f9f PNA |
49 | } |
50 | ||
6be3d859 | 51 | static void state_mt_destroy(const struct xt_mtdtor_param *par) |
b9f78f9f | 52 | { |
aa5fa318 | 53 | nf_ct_l3proto_module_put(par->family); |
b9f78f9f PNA |
54 | } |
55 | ||
b4467288 JE |
56 | static struct xt_match state_mt_reg __read_mostly = { |
57 | .name = "state", | |
58 | .family = NFPROTO_UNSPEC, | |
59 | .checkentry = state_mt_check, | |
60 | .match = state_mt, | |
61 | .destroy = state_mt_destroy, | |
62 | .matchsize = sizeof(struct xt_state_info), | |
63 | .me = THIS_MODULE, | |
1da177e4 LT |
64 | }; |
65 | ||
d3c5ee6d | 66 | static int __init state_mt_init(void) |
1da177e4 | 67 | { |
b4467288 | 68 | return xt_register_match(&state_mt_reg); |
1da177e4 LT |
69 | } |
70 | ||
d3c5ee6d | 71 | static void __exit state_mt_exit(void) |
1da177e4 | 72 | { |
b4467288 | 73 | xt_unregister_match(&state_mt_reg); |
1da177e4 LT |
74 | } |
75 | ||
d3c5ee6d JE |
76 | module_init(state_mt_init); |
77 | module_exit(state_mt_exit); |