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/* Kernel module to match EUI64 address parameters. */
/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.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/ipv6.h>
#include <linux/if_ether.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
MODULE_DESCRIPTION("Xtables: IPv6 EUI64 address match");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
static bool
eui64_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
{
unsigned char eui64[8];
int i = 0;
if (!(skb_mac_header(skb) >= skb->head &&
skb_mac_header(skb) + ETH_HLEN <= skb->data) &&
par->fragoff != 0) {
*par->hotdrop = true;
return false;
}
memset(eui64, 0, sizeof(eui64));
if (eth_hdr(skb)->h_proto == htons(ETH_P_IPV6)) {
if (ipv6_hdr(skb)->version == 0x6) {
memcpy(eui64, eth_hdr(skb)->h_source, 3);
memcpy(eui64 + 5, eth_hdr(skb)->h_source + 3, 3);
eui64[3] = 0xff;
eui64[4] = 0xfe;
eui64[0] ^= 0x02;
i = 0;
while (ipv6_hdr(skb)->saddr.s6_addr[8 + i] == eui64[i]
&& i < 8)
i++;
if (i == 8)
return true;
}
}
return false;
}
static struct xt_match eui64_mt6_reg __read_mostly = {
.name = "eui64",
.family = NFPROTO_IPV6,
.match = eui64_mt6,
.matchsize = sizeof(int),
.hooks = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_IN) |
(1 << NF_INET_FORWARD),
.me = THIS_MODULE,
};
static int __init eui64_mt6_init(void)
{
return xt_register_match(&eui64_mt6_reg);
}
static void __exit eui64_mt6_exit(void)
{
xt_unregister_match(&eui64_mt6_reg);
}
module_init(eui64_mt6_init);
module_exit(eui64_mt6_exit);
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