/* * iptables module to match IP address ranges * * (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> * * 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 <linux/ip.h>#include <linux/netfilter_ipv4/ip_tables.h>#include <linux/netfilter_ipv4/ipt_iprange.h>MODULE_LICENSE("GPL");MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");MODULE_DESCRIPTION("iptables arbitrary IP range match module");#if 0#define DEBUGP printk#else#define DEBUGP(format, args...)#endifstatic intmatch(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_iprange_info *info = matchinfo;	const struct iphdr *iph = skb->nh.iph;	if (info->flags & IPRANGE_SRC) {		if (((ntohl(iph->saddr) < ntohl(info->src.min_ip))			  || (ntohl(iph->saddr) > ntohl(info->src.max_ip)))			 ^ !!(info->flags & IPRANGE_SRC_INV)) {			DEBUGP("src IP %u.%u.%u.%u NOT in range %s"			       "%u.%u.%u.%u-%u.%u.%u.%u\n",				NIPQUAD(iph->saddr),			        info->flags & IPRANGE_SRC_INV ? "(INV) " : "",				NIPQUAD(info->src.min_ip),				NIPQUAD(info->src.max_ip));			return 0;		}	}	if (info->flags & IPRANGE_DST) {		if (((ntohl(iph->daddr) < ntohl(info->dst.min_ip))			  || (ntohl(iph->daddr) > ntohl(info->dst.max_ip)))			 ^ !!(info->flags & IPRANGE_DST_INV)) {			DEBUGP("dst IP %u.%u.%u.%u NOT in range %s"			       "%u.%u.%u.%u-%u.%u.%u.%u\n",				NIPQUAD(iph->daddr),			        info->flags & IPRANGE_DST_INV ? "(INV) " : "",				NIPQUAD(info->dst.min_ip),				NIPQUAD(info->dst.max_ip));			return 0;		}	}	return 1;}static int check(const char *tablename,		 const struct ipt_ip *ip,		 void *matchinfo,		 unsigned int matchsize,		 unsigned int hook_mask){	/* verify size */	if (matchsize != IPT_ALIGN(sizeof(struct ipt_iprange_info)))		return 0;	return 1;}static struct ipt_match iprange_match = { 	.list = { NULL, NULL }, 	.name = "iprange", 	.match = &match, 	.checkentry = &check, 	.destroy = NULL, 	.me = THIS_MODULE};static int __init init(void){	return ipt_register_match(&iprange_match);}static void __exit fini(void){	ipt_unregister_match(&iprange_match);}module_init(init);module_exit(fini);