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> |
| 13 | #include <net/netfilter/nf_conntrack_compat.h> |
| 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 | |
| 23 | static int |
| 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, |
| 31 | int *hotdrop) |
| 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; |
| 39 | else if (!nf_ct_get_ctinfo(skb, &ctinfo)) |
| 40 | statebit = XT_STATE_INVALID; |
| 41 | else |
| 42 | statebit = XT_STATE_BIT(ctinfo); |
| 43 | |
| 44 | return (sinfo->statemask & statebit); |
| 45 | } |
| 46 | |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 47 | static int check(const char *tablename, |
| 48 | const void *inf, |
| 49 | const struct xt_match *match, |
| 50 | void *matchinfo, |
| 51 | unsigned int matchsize, |
| 52 | unsigned int hook_mask) |
| 53 | { |
| 54 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
| 55 | if (nf_ct_l3proto_try_module_get(match->family) < 0) { |
| 56 | printk(KERN_WARNING "can't load nf_conntrack support for " |
| 57 | "proto=%d\n", match->family); |
| 58 | return 0; |
| 59 | } |
| 60 | #endif |
| 61 | return 1; |
| 62 | } |
| 63 | |
| 64 | static void |
| 65 | destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize) |
| 66 | { |
| 67 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
| 68 | nf_ct_l3proto_module_put(match->family); |
| 69 | #endif |
| 70 | } |
| 71 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 72 | static struct xt_match state_match = { |
| 73 | .name = "state", |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 74 | .match = match, |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 75 | .checkentry = check, |
| 76 | .destroy = destroy, |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 77 | .matchsize = sizeof(struct xt_state_info), |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 78 | .family = AF_INET, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 79 | .me = THIS_MODULE, |
| 80 | }; |
| 81 | |
| 82 | static struct xt_match state6_match = { |
| 83 | .name = "state", |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 84 | .match = match, |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 85 | .checkentry = check, |
| 86 | .destroy = destroy, |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 87 | .matchsize = sizeof(struct xt_state_info), |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 88 | .family = AF_INET6, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 89 | .me = THIS_MODULE, |
| 90 | }; |
| 91 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 92 | static int __init xt_state_init(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 93 | { |
| 94 | int ret; |
| 95 | |
| 96 | need_conntrack(); |
| 97 | |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 98 | ret = xt_register_match(&state_match); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 99 | if (ret < 0) |
| 100 | return ret; |
| 101 | |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 102 | ret = xt_register_match(&state6_match); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 103 | if (ret < 0) |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 104 | xt_unregister_match(&state_match); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 105 | |
| 106 | return ret; |
| 107 | } |
| 108 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 109 | static void __exit xt_state_fini(void) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 110 | { |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 111 | xt_unregister_match(&state_match); |
| 112 | xt_unregister_match(&state6_match); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 113 | } |
| 114 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 115 | module_init(xt_state_init); |
| 116 | module_exit(xt_state_fini); |