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 | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 24 | state_mt(const struct sk_buff *skb, const struct net_device *in, |
| 25 | const struct net_device *out, const struct xt_match *match, |
| 26 | const void *matchinfo, int offset, unsigned int protoff, |
| 27 | bool *hotdrop) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 28 | { |
| 29 | const struct xt_state_info *sinfo = matchinfo; |
| 30 | enum ip_conntrack_info ctinfo; |
| 31 | unsigned int statebit; |
| 32 | |
| 33 | if (nf_ct_is_untracked(skb)) |
| 34 | statebit = XT_STATE_UNTRACKED; |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 35 | else if (!nf_ct_get(skb, &ctinfo)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 36 | statebit = XT_STATE_INVALID; |
| 37 | else |
| 38 | statebit = XT_STATE_BIT(ctinfo); |
| 39 | |
| 40 | return (sinfo->statemask & statebit); |
| 41 | } |
| 42 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 43 | static bool |
| 44 | state_mt_check(const char *tablename, const void *inf, |
| 45 | const struct xt_match *match, void *matchinfo, |
| 46 | unsigned int hook_mask) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 47 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 48 | if (nf_ct_l3proto_try_module_get(match->family) < 0) { |
Yasuyuki Kozakai | fe0b929 | 2006-12-12 00:28:40 -0800 | [diff] [blame] | 49 | printk(KERN_WARNING "can't load conntrack support for " |
Jan Engelhardt | df54aae | 2007-12-17 22:43:15 -0800 | [diff] [blame] | 50 | "proto=%u\n", match->family); |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 51 | return false; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 52 | } |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 53 | return true; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 54 | } |
| 55 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 56 | static void state_mt_destroy(const struct xt_match *match, void *matchinfo) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 57 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 58 | nf_ct_l3proto_module_put(match->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 59 | } |
| 60 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 61 | static struct xt_match state_mt_reg[] __read_mostly = { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 62 | { |
| 63 | .name = "state", |
| 64 | .family = AF_INET, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 65 | .checkentry = state_mt_check, |
| 66 | .match = state_mt, |
| 67 | .destroy = state_mt_destroy, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 68 | .matchsize = sizeof(struct xt_state_info), |
| 69 | .me = THIS_MODULE, |
| 70 | }, |
| 71 | { |
| 72 | .name = "state", |
| 73 | .family = AF_INET6, |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 74 | .checkentry = state_mt_check, |
| 75 | .match = state_mt, |
| 76 | .destroy = state_mt_destroy, |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 77 | .matchsize = sizeof(struct xt_state_info), |
| 78 | .me = THIS_MODULE, |
| 79 | }, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 80 | }; |
| 81 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 82 | static int __init state_mt_init(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 83 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 84 | return xt_register_matches(state_mt_reg, ARRAY_SIZE(state_mt_reg)); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 85 | } |
| 86 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 87 | static void __exit state_mt_exit(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 88 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 89 | xt_unregister_matches(state_mt_reg, ARRAY_SIZE(state_mt_reg)); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 90 | } |
| 91 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 92 | module_init(state_mt_init); |
| 93 | module_exit(state_mt_exit); |