/* Kernel module to match connection tracking information. */ /* (C) 1999-2001 Paul `Rusty' Russell * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/module.h>#include <linux/skbuff.h>#include <net/netfilter/nf_conntrack_compat.h>#include <linux/netfilter/x_tables.h>#include <linux/netfilter/xt_state.h> MODULE_LICENSE("GPL");MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");MODULE_ALIAS("ipt_state");MODULE_ALIAS("ip6t_state"); static intmatch(const struct sk_buff *skb,      const struct net_device *in,      const struct net_device *out,      const struct xt_match *match,      const void *matchinfo,      int offset,      unsigned int protoff,      int *hotdrop){	const struct xt_state_info *sinfo = matchinfo;	enum ip_conntrack_info ctinfo;	unsigned int statebit; 	if (nf_ct_is_untracked(skb))		statebit = XT_STATE_UNTRACKED;	else if (!nf_ct_get_ctinfo(skb, &ctinfo))		statebit = XT_STATE_INVALID;	else		statebit = XT_STATE_BIT(ctinfo); 	return (sinfo->statemask & statebit);} static int check(const char *tablename,		 const void *inf,		 const struct xt_match *match,		 void *matchinfo,		 unsigned int matchsize,		 unsigned int hook_mask){#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)	if (nf_ct_l3proto_try_module_get(match->family) < 0) {		printk(KERN_WARNING "can't load nf_conntrack support for "				    "proto=%d\n", match->family);		return 0;	}#endif	return 1;} static voiddestroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize){#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)	nf_ct_l3proto_module_put(match->family);#endif} static struct xt_match state_match = {	.name		= "state",	.match		= match,	.checkentry	= check,	.destroy	= destroy,	.matchsize	= sizeof(struct xt_state_info),	.family		= AF_INET,	.me		= THIS_MODULE,}; static struct xt_match state6_match = {	.name		= "state",	.match		= match,	.checkentry	= check,	.destroy	= destroy,	.matchsize	= sizeof(struct xt_state_info),	.family		= AF_INET6,	.me		= THIS_MODULE,}; static int __init xt_state_init(void){	int ret; 	need_conntrack(); 	ret = xt_register_match(&state_match);	if (ret < 0)		return ret; 	ret = xt_register_match(&state6_match);	if (ret < 0)		xt_unregister_match(&state_match); 	return ret;} static void __exit xt_state_fini(void){	xt_unregister_match(&state_match);	xt_unregister_match(&state6_match);} module_init(xt_state_init);module_exit(xt_state_fini);