| 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, |
| 27 | const void *matchinfo, |
| 28 | int offset, |
| 29 | unsigned int protoff, |
| 30 | int *hotdrop) |
| 31 | { |
| 32 | const struct xt_state_info *sinfo = matchinfo; |
| 33 | enum ip_conntrack_info ctinfo; |
| 34 | unsigned int statebit; |
| 35 | |
| 36 | if (nf_ct_is_untracked(skb)) |
| 37 | statebit = XT_STATE_UNTRACKED; |
| 38 | else if (!nf_ct_get_ctinfo(skb, &ctinfo)) |
| 39 | statebit = XT_STATE_INVALID; |
| 40 | else |
| 41 | statebit = XT_STATE_BIT(ctinfo); |
| 42 | |
| 43 | return (sinfo->statemask & statebit); |
| 44 | } |
| 45 | |
| 46 | static int check(const char *tablename, |
| 47 | const void *ip, |
| 48 | void *matchinfo, |
| 49 | unsigned int matchsize, |
| 50 | unsigned int hook_mask) |
| 51 | { |
| 52 | if (matchsize != XT_ALIGN(sizeof(struct xt_state_info))) |
| 53 | return 0; |
| 54 | |
| 55 | return 1; |
| 56 | } |
| 57 | |
| 58 | static struct xt_match state_match = { |
| 59 | .name = "state", |
| 60 | .match = &match, |
| 61 | .checkentry = &check, |
| 62 | .me = THIS_MODULE, |
| 63 | }; |
| 64 | |
| 65 | static struct xt_match state6_match = { |
| 66 | .name = "state", |
| 67 | .match = &match, |
| 68 | .checkentry = &check, |
| 69 | .me = THIS_MODULE, |
| 70 | }; |
| 71 | |
| 72 | static int __init init(void) |
| 73 | { |
| 74 | int ret; |
| 75 | |
| 76 | need_conntrack(); |
| 77 | |
| 78 | ret = xt_register_match(AF_INET, &state_match); |
| 79 | if (ret < 0) |
| 80 | return ret; |
| 81 | |
| 82 | ret = xt_register_match(AF_INET6, &state6_match); |
| 83 | if (ret < 0) |
| 84 | xt_unregister_match(AF_INET,&state_match); |
| 85 | |
| 86 | return ret; |
| 87 | } |
| 88 | |
| 89 | static void __exit fini(void) |
| 90 | { |
| 91 | xt_unregister_match(AF_INET, &state_match); |
| 92 | xt_unregister_match(AF_INET6, &state6_match); |
| 93 | } |
| 94 | |
| 95 | module_init(init); |
| 96 | module_exit(fini); |