blob: ca29ec00dc188f7b2ab3a5021ed9ad6e4a8cb68d [file] [log] [blame]
/* Hop Limit matching module */
/* (C) 2001-2002 Maciej Soltysiak <solt@dns.toxicfilms.tv>
* Based on HW's ttl module
*
* 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/ipv6.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter_ipv6/ip6t_hl.h>
#include <linux/netfilter/x_tables.h>
MODULE_AUTHOR("Maciej Soltysiak <solt@dns.toxicfilms.tv>");
MODULE_DESCRIPTION("IP tables Hop Limit matching module");
MODULE_LICENSE("GPL");
static bool match(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, bool *hotdrop)
{
const struct ip6t_hl_info *info = matchinfo;
const struct ipv6hdr *ip6h = ipv6_hdr(skb);
switch (info->mode) {
case IP6T_HL_EQ:
return ip6h->hop_limit == info->hop_limit;
break;
case IP6T_HL_NE:
return ip6h->hop_limit != info->hop_limit;
break;
case IP6T_HL_LT:
return ip6h->hop_limit < info->hop_limit;
break;
case IP6T_HL_GT:
return ip6h->hop_limit > info->hop_limit;
break;
default:
printk(KERN_WARNING "ip6t_hl: unknown mode %d\n",
info->mode);
return false;
}
return false;
}
static struct xt_match hl_match __read_mostly = {
.name = "hl",
.family = AF_INET6,
.match = match,
.matchsize = sizeof(struct ip6t_hl_info),
.me = THIS_MODULE,
};
static int __init ip6t_hl_init(void)
{
return xt_register_match(&hl_match);
}
static void __exit ip6t_hl_fini(void)
{
xt_unregister_match(&hl_match);
}
module_init(ip6t_hl_init);
module_exit(ip6t_hl_fini);