Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 2 | /* Kernel module to match connection tracking information. */ |
| 3 | |
| 4 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 5 | * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/skbuff.h> |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 10 | #include <net/netfilter/nf_conntrack.h> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 11 | #include <linux/netfilter/x_tables.h> |
| 12 | #include <linux/netfilter/xt_state.h> |
| 13 | |
| 14 | MODULE_LICENSE("GPL"); |
| 15 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); |
| 16 | MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module"); |
| 17 | MODULE_ALIAS("ipt_state"); |
| 18 | MODULE_ALIAS("ip6t_state"); |
| 19 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 20 | static bool |
Jan Engelhardt | 62fc805 | 2009-07-07 20:42:08 +0200 | [diff] [blame] | 21 | state_mt(const struct sk_buff *skb, struct xt_action_param *par) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 22 | { |
Jan Engelhardt | f7108a20 | 2008-10-08 11:35:18 +0200 | [diff] [blame] | 23 | const struct xt_state_info *sinfo = par->matchinfo; |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 24 | enum ip_conntrack_info ctinfo; |
| 25 | unsigned int statebit; |
Eric Dumazet | 5bfddbd | 2010-06-08 16:09:52 +0200 | [diff] [blame] | 26 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 27 | |
Florian Westphal | cc41c84 | 2017-04-14 20:31:08 +0200 | [diff] [blame] | 28 | if (ct) |
| 29 | statebit = XT_STATE_BIT(ctinfo); |
| 30 | else if (ctinfo == IP_CT_UNTRACKED) |
| 31 | statebit = XT_STATE_UNTRACKED; |
| 32 | else |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 33 | statebit = XT_STATE_INVALID; |
Florian Westphal | cc41c84 | 2017-04-14 20:31:08 +0200 | [diff] [blame] | 34 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 35 | return (sinfo->statemask & statebit); |
| 36 | } |
| 37 | |
Jan Engelhardt | b0f3845 | 2010-03-19 17:16:42 +0100 | [diff] [blame] | 38 | static int state_mt_check(const struct xt_mtchk_param *par) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 39 | { |
Jan Engelhardt | 4a5a5c7 | 2010-03-19 17:32:59 +0100 | [diff] [blame] | 40 | int ret; |
| 41 | |
Florian Westphal | ecb2421 | 2016-11-15 21:36:40 +0100 | [diff] [blame] | 42 | ret = nf_ct_netns_get(par->net, par->family); |
Jan Engelhardt | f95c74e | 2010-03-21 04:05:56 +0100 | [diff] [blame] | 43 | if (ret < 0) |
Florian Westphal | b260664 | 2018-02-09 15:52:07 +0100 | [diff] [blame] | 44 | pr_info_ratelimited("cannot load conntrack support for proto=%u\n", |
| 45 | par->family); |
Jan Engelhardt | f95c74e | 2010-03-21 04:05:56 +0100 | [diff] [blame] | 46 | return ret; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 47 | } |
| 48 | |
Jan Engelhardt | 6be3d85 | 2008-10-08 11:35:19 +0200 | [diff] [blame] | 49 | static void state_mt_destroy(const struct xt_mtdtor_param *par) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 50 | { |
Florian Westphal | ecb2421 | 2016-11-15 21:36:40 +0100 | [diff] [blame] | 51 | nf_ct_netns_put(par->net, par->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 52 | } |
| 53 | |
Jan Engelhardt | b446728 | 2010-03-24 22:50:01 +0100 | [diff] [blame] | 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, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 62 | }; |
| 63 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 64 | static int __init state_mt_init(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 65 | { |
Jan Engelhardt | b446728 | 2010-03-24 22:50:01 +0100 | [diff] [blame] | 66 | return xt_register_match(&state_mt_reg); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 67 | } |
| 68 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 69 | static void __exit state_mt_exit(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 70 | { |
Jan Engelhardt | b446728 | 2010-03-24 22:50:01 +0100 | [diff] [blame] | 71 | xt_unregister_match(&state_mt_reg); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 72 | } |
| 73 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 74 | module_init(state_mt_init); |
| 75 | module_exit(state_mt_exit); |