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/*
* 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);
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