Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 1 | /* Kernel module to match connection tracking information. */ |
| 2 | |
| 3 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 4 | * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org> |
| 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> |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 13 | #include <net/netfilter/nf_conntrack.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 14 | #include <linux/netfilter/x_tables.h> |
| 15 | #include <linux/netfilter/xt_state.h> |
| 16 | |
| 17 | MODULE_LICENSE("GPL"); |
| 18 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); |
| 19 | MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module"); |
| 20 | MODULE_ALIAS("ipt_state"); |
| 21 | MODULE_ALIAS("ip6t_state"); |
| 22 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 23 | static bool |
Jan Engelhardt | 62fc805 | 2009-07-07 20:42:08 +0200 | [diff] [blame] | 24 | state_mt(const struct sk_buff *skb, struct xt_action_param *par) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 25 | { |
Jan Engelhardt | f7108a2 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 26 | const struct xt_state_info *sinfo = par->matchinfo; |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 27 | enum ip_conntrack_info ctinfo; |
| 28 | unsigned int statebit; |
| 29 | |
| 30 | if (nf_ct_is_untracked(skb)) |
| 31 | statebit = XT_STATE_UNTRACKED; |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 32 | else if (!nf_ct_get(skb, &ctinfo)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 33 | statebit = XT_STATE_INVALID; |
| 34 | else |
| 35 | statebit = XT_STATE_BIT(ctinfo); |
| 36 | |
| 37 | return (sinfo->statemask & statebit); |
| 38 | } |
| 39 | |
Jan Engelhardt | b0f3845 | 2010-03-19 17:16:42 +0100 | [diff] [blame] | 40 | static int state_mt_check(const struct xt_mtchk_param *par) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 41 | { |
Jan Engelhardt | 4a5a5c7 | 2010-03-19 17:32:59 +0100 | [diff] [blame] | 42 | int ret; |
| 43 | |
| 44 | ret = nf_ct_l3proto_try_module_get(par->family); |
Jan Engelhardt | f95c74e | 2010-03-21 04:05:56 +0100 | [diff] [blame] | 45 | if (ret < 0) |
Jan Engelhardt | 8bee4ba | 2010-03-17 16:04:40 +0100 | [diff] [blame] | 46 | pr_info("cannot load conntrack support for proto=%u\n", |
| 47 | par->family); |
Jan Engelhardt | f95c74e | 2010-03-21 04:05:56 +0100 | [diff] [blame] | 48 | return ret; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 49 | } |
| 50 | |
Jan Engelhardt | 6be3d85 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 51 | static void state_mt_destroy(const struct xt_mtdtor_param *par) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 52 | { |
Jan Engelhardt | aa5fa31 | 2010-03-18 00:44:52 +0100 | [diff] [blame] | 53 | nf_ct_l3proto_module_put(par->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 54 | } |
| 55 | |
Jan Engelhardt | b446728 | 2010-03-24 22:50:01 +0100 | [diff] [blame] | 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, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 64 | }; |
| 65 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 66 | static int __init state_mt_init(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 67 | { |
Jan Engelhardt | b446728 | 2010-03-24 22:50:01 +0100 | [diff] [blame] | 68 | return xt_register_match(&state_mt_reg); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 69 | } |
| 70 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 71 | static void __exit state_mt_exit(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 72 | { |
Jan Engelhardt | b446728 | 2010-03-24 22:50:01 +0100 | [diff] [blame] | 73 | xt_unregister_match(&state_mt_reg); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 74 | } |
| 75 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 76 | module_init(state_mt_init); |
| 77 | module_exit(state_mt_exit); |