/* *  iptables module to match inet_addr_type() of an ip. * *  Copyright (c) 2004 Patrick McHardy <kaber@trash.net> * *  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/kernel.h>#include <linux/module.h>#include <linux/skbuff.h>#include <linux/netdevice.h>#include <linux/ip.h>#include <net/route.h>#include <linux/netfilter_ipv4/ipt_addrtype.h>#include <linux/netfilter_ipv4/ip_tables.h>MODULE_LICENSE("GPL");MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");MODULE_DESCRIPTION("iptables addrtype match");static inline int match_type(u_int32_t addr, u_int16_t mask){	return !!(mask & (1 << inet_addr_type(addr)));}static int match(const struct sk_buff *skb, const struct net_device *in,		 const struct net_device *out, const void *matchinfo,		 int offset, int *hotdrop){	const struct ipt_addrtype_info *info = matchinfo;	const struct iphdr *iph = skb->nh.iph;	int ret = 1;	if (info->source)		ret &= match_type(iph->saddr, info->source)^info->invert_source;	if (info->dest)		ret &= match_type(iph->daddr, info->dest)^info->invert_dest;		return ret;}static int checkentry(const char *tablename, const struct ipt_ip *ip,		      void *matchinfo, unsigned int matchsize,		      unsigned int hook_mask){	if (matchsize != IPT_ALIGN(sizeof(struct ipt_addrtype_info))) {		printk(KERN_ERR "ipt_addrtype: invalid size (%u != %Zu)\n.",		       matchsize, IPT_ALIGN(sizeof(struct ipt_addrtype_info)));		return 0;	}	return 1;}static struct ipt_match addrtype_match = {	.name		= "addrtype",	.match		= match,	.checkentry	= checkentry,	.me		= THIS_MODULE};static int __init init(void){	return ipt_register_match(&addrtype_match);}static void __exit fini(void){	ipt_unregister_match(&addrtype_match);}module_init(init);module_exit(fini);