Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* 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);