1/* Kernel module to match EUI64 address parameters. */ 2 3/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 10#include <linux/module.h> 11#include <linux/skbuff.h> 12#include <linux/ipv6.h> 13#include <linux/if_ether.h> 14 15#include <linux/netfilter/x_tables.h> 16#include <linux/netfilter_ipv6/ip6_tables.h> 17 18MODULE_DESCRIPTION("IPv6 EUI64 address checking match"); 19MODULE_LICENSE("GPL"); 20MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); 21 22static int 23match(const struct sk_buff *skb, 24 const struct net_device *in, 25 const struct net_device *out, 26 const struct xt_match *match, 27 const void *matchinfo, 28 int offset, 29 unsigned int protoff, 30 int *hotdrop) 31{ 32 unsigned char eui64[8]; 33 int i = 0; 34 35 if (!(skb_mac_header(skb) >= skb->head && 36 (skb_mac_header(skb) + ETH_HLEN) <= skb->data) && 37 offset != 0) { 38 *hotdrop = 1; 39 return 0; 40 } 41 42 memset(eui64, 0, sizeof(eui64)); 43 44 if (eth_hdr(skb)->h_proto == htons(ETH_P_IPV6)) { 45 if (ipv6_hdr(skb)->version == 0x6) { 46 memcpy(eui64, eth_hdr(skb)->h_source, 3); 47 memcpy(eui64 + 5, eth_hdr(skb)->h_source + 3, 3); 48 eui64[3] = 0xff; 49 eui64[4] = 0xfe; 50 eui64[0] |= 0x02; 51 52 i = 0; 53 while ((ipv6_hdr(skb)->saddr.s6_addr[8 + i] == eui64[i]) 54 && (i < 8)) 55 i++; 56 57 if (i == 8) 58 return 1; 59 } 60 } 61 62 return 0; 63} 64 65static struct xt_match eui64_match = { 66 .name = "eui64", 67 .family = AF_INET6, 68 .match = match, 69 .matchsize = sizeof(int), 70 .hooks = (1 << NF_IP6_PRE_ROUTING) | (1 << NF_IP6_LOCAL_IN) | 71 (1 << NF_IP6_FORWARD), 72 .me = THIS_MODULE, 73}; 74 75static int __init ip6t_eui64_init(void) 76{ 77 return xt_register_match(&eui64_match); 78} 79 80static void __exit ip6t_eui64_fini(void) 81{ 82 xt_unregister_match(&eui64_match); 83} 84 85module_init(ip6t_eui64_init); 86module_exit(ip6t_eui64_fini); 87