Commit | Line | Data |
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1da177e4 LT |
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 | ||
6709dbbb | 15 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
16 | #include <linux/netfilter_ipv6/ip6_tables.h> |
17 | ||
18 | MODULE_DESCRIPTION("IPv6 EUI64 address checking match"); | |
19 | MODULE_LICENSE("GPL"); | |
20 | MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); | |
21 | ||
1d93a9cb | 22 | static bool |
1da177e4 LT |
23 | match(const struct sk_buff *skb, |
24 | const struct net_device *in, | |
25 | const struct net_device *out, | |
c4986734 | 26 | const struct xt_match *match, |
1da177e4 LT |
27 | const void *matchinfo, |
28 | int offset, | |
29 | unsigned int protoff, | |
cff533ac | 30 | bool *hotdrop) |
1da177e4 | 31 | { |
f0daaa65 YK |
32 | unsigned char eui64[8]; |
33 | int i = 0; | |
1da177e4 | 34 | |
98e399f8 ACM |
35 | if (!(skb_mac_header(skb) >= skb->head && |
36 | (skb_mac_header(skb) + ETH_HLEN) <= skb->data) && | |
f0daaa65 | 37 | offset != 0) { |
cff533ac | 38 | *hotdrop = true; |
1d93a9cb | 39 | return false; |
f0daaa65 YK |
40 | } |
41 | ||
42 | memset(eui64, 0, sizeof(eui64)); | |
43 | ||
d8fd0a73 | 44 | if (eth_hdr(skb)->h_proto == htons(ETH_P_IPV6)) { |
0660e03f | 45 | if (ipv6_hdr(skb)->version == 0x6) { |
f0daaa65 YK |
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; | |
0660e03f | 53 | while ((ipv6_hdr(skb)->saddr.s6_addr[8 + i] == eui64[i]) |
f0daaa65 YK |
54 | && (i < 8)) |
55 | i++; | |
56 | ||
57 | if (i == 8) | |
1d93a9cb | 58 | return true; |
f0daaa65 YK |
59 | } |
60 | } | |
61 | ||
1d93a9cb | 62 | return false; |
1da177e4 LT |
63 | } |
64 | ||
6709dbbb | 65 | static struct xt_match eui64_match = { |
1da177e4 | 66 | .name = "eui64", |
6709dbbb | 67 | .family = AF_INET6, |
7f939713 PM |
68 | .match = match, |
69 | .matchsize = sizeof(int), | |
70 | .hooks = (1 << NF_IP6_PRE_ROUTING) | (1 << NF_IP6_LOCAL_IN) | | |
71 | (1 << NF_IP6_FORWARD), | |
1da177e4 LT |
72 | .me = THIS_MODULE, |
73 | }; | |
74 | ||
65b4b4e8 | 75 | static int __init ip6t_eui64_init(void) |
1da177e4 | 76 | { |
6709dbbb | 77 | return xt_register_match(&eui64_match); |
1da177e4 LT |
78 | } |
79 | ||
65b4b4e8 | 80 | static void __exit ip6t_eui64_fini(void) |
1da177e4 | 81 | { |
6709dbbb | 82 | xt_unregister_match(&eui64_match); |
1da177e4 LT |
83 | } |
84 | ||
65b4b4e8 AM |
85 | module_init(ip6t_eui64_init); |
86 | module_exit(ip6t_eui64_fini); |