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Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* Kernel module to match connection tracking information. */ |
3 | ||
4 | /* (C) 1999-2001 Paul `Rusty' Russell | |
2e4e6a17 | 5 | * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org> |
1da177e4 LT |
6 | */ |
7 | ||
8 | #include <linux/module.h> | |
9 | #include <linux/skbuff.h> | |
587aa641 | 10 | #include <net/netfilter/nf_conntrack.h> |
2e4e6a17 HW |
11 | #include <linux/netfilter/x_tables.h> |
12 | #include <linux/netfilter/xt_state.h> | |
1da177e4 LT |
13 | |
14 | MODULE_LICENSE("GPL"); | |
15 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); | |
2e4e6a17 HW |
16 | MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module"); |
17 | MODULE_ALIAS("ipt_state"); | |
18 | MODULE_ALIAS("ip6t_state"); | |
1da177e4 | 19 | |
1d93a9cb | 20 | static bool |
62fc8051 | 21 | state_mt(const struct sk_buff *skb, struct xt_action_param *par) |
1da177e4 | 22 | { |
f7108a20 | 23 | const struct xt_state_info *sinfo = par->matchinfo; |
1da177e4 LT |
24 | enum ip_conntrack_info ctinfo; |
25 | unsigned int statebit; | |
5bfddbd4 | 26 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
1da177e4 | 27 | |
cc41c84b FW |
28 | if (ct) |
29 | statebit = XT_STATE_BIT(ctinfo); | |
30 | else if (ctinfo == IP_CT_UNTRACKED) | |
31 | statebit = XT_STATE_UNTRACKED; | |
32 | else | |
2e4e6a17 | 33 | statebit = XT_STATE_INVALID; |
cc41c84b | 34 | |
1da177e4 LT |
35 | return (sinfo->statemask & statebit); |
36 | } | |
37 | ||
b0f38452 | 38 | static int state_mt_check(const struct xt_mtchk_param *par) |
b9f78f9f | 39 | { |
4a5a5c73 JE |
40 | int ret; |
41 | ||
ecb2421b | 42 | ret = nf_ct_netns_get(par->net, par->family); |
f95c74e3 | 43 | if (ret < 0) |
b2606644 FW |
44 | pr_info_ratelimited("cannot load conntrack support for proto=%u\n", |
45 | par->family); | |
f95c74e3 | 46 | return ret; |
b9f78f9f PNA |
47 | } |
48 | ||
6be3d859 | 49 | static void state_mt_destroy(const struct xt_mtdtor_param *par) |
b9f78f9f | 50 | { |
ecb2421b | 51 | nf_ct_netns_put(par->net, par->family); |
b9f78f9f PNA |
52 | } |
53 | ||
b4467288 JE |
54 | static struct xt_match state_mt_reg __read_mostly = { |
55 | .name = "state", | |
56 | .family = NFPROTO_UNSPEC, | |
57 | .checkentry = state_mt_check, | |
58 | .match = state_mt, | |
59 | .destroy = state_mt_destroy, | |
60 | .matchsize = sizeof(struct xt_state_info), | |
61 | .me = THIS_MODULE, | |
1da177e4 LT |
62 | }; |
63 | ||
d3c5ee6d | 64 | static int __init state_mt_init(void) |
1da177e4 | 65 | { |
b4467288 | 66 | return xt_register_match(&state_mt_reg); |
1da177e4 LT |
67 | } |
68 | ||
d3c5ee6d | 69 | static void __exit state_mt_exit(void) |
1da177e4 | 70 | { |
b4467288 | 71 | xt_unregister_match(&state_mt_reg); |
1da177e4 LT |
72 | } |
73 | ||
d3c5ee6d JE |
74 | module_init(state_mt_init); |
75 | module_exit(state_mt_exit); |