/* IP tables module for matching the routing realm
*
* $Id: ipt_realm.c,v 1.3 2004/03/05 13:25:40 laforge Exp $
* (C) 2003 by Sampsa Ranta <sampsa@netsonic.fi>
* 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/netdevice.h>
#include <net/route.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/xt_realm.h>
#include <linux/netfilter/x_tables.h>
MODULE_AUTHOR("Sampsa Ranta <sampsa@netsonic.fi>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("X_tables realm match");
MODULE_ALIAS("ipt_realm");
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
const struct xt_realm_info *info = matchinfo;
struct dst_entry *dst = skb->dst;
return (info->id == (dst->tclassid & info->mask)) ^ info->invert;
}
static int check(const char *tablename,
const void *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
if (hook_mask
& ~((1 << NF_IP_POST_ROUTING) | (1 << NF_IP_FORWARD) |
(1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_LOCAL_IN))) {
printk("xt_realm: only valid for POST_ROUTING, LOCAL_OUT, "
"LOCAL_IN or FORWARD.\n");
return 0;
if (matchsize != XT_ALIGN(sizeof(struct xt_realm_info))) {
printk("xt_realm: invalid matchsize.\n");
return 1;
static struct xt_match realm_match = {
.name = "realm",
.match = match,
.checkentry = check,
.me = THIS_MODULE
};
static int __init init(void)
return xt_register_match(AF_INET, &realm_match);
static void __exit fini(void)
xt_unregister_match(AF_INET, &realm_match);
module_init(init);
module_exit(fini);