![Patrick McHardy](/assets/img/avatar_default.png)
Use memcmp() instead of open coded comparison that reads one byte past the intended end. Based on patch from Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/* 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];
|
|
|
|
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;
|
|
|
|
if (!memcmp(ipv6_hdr(skb)->saddr.s6_addr + 8, eui64,
|
|
sizeof(eui64)))
|
|
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);
|