linux-stable/net/ipv6/netfilter/ip6t_eui64.c
Jan Engelhardt f7108a20de netfilter: xtables: move extension arguments into compound structure (1/6)
The function signatures for Xtables extensions have grown over time.
It involves a lot of typing/replication, and also a bit of stack space
even if they are not used. Realize an NFWS2008 idea and pack them into
structs. The skb remains outside of the struct so gcc can continue to
apply its optimizations.

This patch does this for match extensions' match functions.

A few ambiguities have also been addressed. The "offset" parameter for
example has been renamed to "fragoff" (there are so many different
offsets already) and "protoff" to "thoff" (there is more than just one
protocol here, so clarify).

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-10-08 11:35:18 +02:00

79 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];
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);