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 |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 24 | match(const struct sk_buff *skb, |
| 25 | const struct net_device *in, |
| 26 | const struct net_device *out, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 27 | const struct xt_match *match, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 28 | const void *matchinfo, |
| 29 | int offset, |
| 30 | unsigned int protoff, |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 31 | bool *hotdrop) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 32 | { |
| 33 | const struct xt_state_info *sinfo = matchinfo; |
| 34 | enum ip_conntrack_info ctinfo; |
| 35 | unsigned int statebit; |
| 36 | |
| 37 | if (nf_ct_is_untracked(skb)) |
| 38 | statebit = XT_STATE_UNTRACKED; |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 39 | else if (!nf_ct_get(skb, &ctinfo)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 40 | statebit = XT_STATE_INVALID; |
| 41 | else |
| 42 | statebit = XT_STATE_BIT(ctinfo); |
| 43 | |
| 44 | return (sinfo->statemask & statebit); |
| 45 | } |
| 46 | |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 47 | static bool check(const char *tablename, |
| 48 | const void *inf, |
| 49 | const struct xt_match *match, |
| 50 | void *matchinfo, |
| 51 | unsigned int hook_mask) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 52 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 53 | if (nf_ct_l3proto_try_module_get(match->family) < 0) { |
Yasuyuki Kozakai | fe0b929 | 2006-12-12 00:28:40 -0800 | [diff] [blame] | 54 | printk(KERN_WARNING "can't load conntrack support for " |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 55 | "proto=%d\n", match->family); |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 56 | return false; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 57 | } |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 58 | return true; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | static void |
Patrick McHardy | efa7416 | 2006-08-22 00:36:37 -0700 | [diff] [blame] | 62 | destroy(const struct xt_match *match, void *matchinfo) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 63 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 64 | nf_ct_l3proto_module_put(match->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 65 | } |
| 66 | |
Patrick McHardy | 9f15c53 | 2007-07-07 22:22:02 -0700 | [diff] [blame] | 67 | static struct xt_match xt_state_match[] __read_mostly = { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 68 | { |
| 69 | .name = "state", |
| 70 | .family = AF_INET, |
| 71 | .checkentry = check, |
| 72 | .match = match, |
| 73 | .destroy = destroy, |
| 74 | .matchsize = sizeof(struct xt_state_info), |
| 75 | .me = THIS_MODULE, |
| 76 | }, |
| 77 | { |
| 78 | .name = "state", |
| 79 | .family = AF_INET6, |
| 80 | .checkentry = check, |
| 81 | .match = match, |
| 82 | .destroy = destroy, |
| 83 | .matchsize = sizeof(struct xt_state_info), |
| 84 | .me = THIS_MODULE, |
| 85 | }, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 86 | }; |
| 87 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 88 | static int __init xt_state_init(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 89 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 90 | return xt_register_matches(xt_state_match, ARRAY_SIZE(xt_state_match)); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 91 | } |
| 92 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 93 | static void __exit xt_state_fini(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 94 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 95 | xt_unregister_matches(xt_state_match, ARRAY_SIZE(xt_state_match)); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 96 | } |
| 97 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 98 | module_init(xt_state_init); |
| 99 | module_exit(xt_state_fini); |