2 * Copyright (C)2006 USAGI/WIDE Project
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 * Masahide NAKAMURA @USAGI <masahide.nakamura.cz@hitachi.com>
11 * Based on net/netfilter/xt_tcpudp.c
14 #include <linux/types.h>
15 #include <linux/module.h>
17 #include <linux/ipv6.h>
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter_ipv6/ip6t_mh.h>
24 MODULE_DESCRIPTION("ip6t_tables match for MH");
25 MODULE_LICENSE("GPL");
27 #ifdef DEBUG_IP_FIREWALL_USER
28 #define duprintf(format, args...) printk(format , ## args)
30 #define duprintf(format, args...)
33 /* Returns 1 if the type is matched by the range, 0 otherwise */
35 type_match(u_int8_t min, u_int8_t max, u_int8_t type, bool invert)
37 return (type >= min && type <= max) ^ invert;
41 match(const struct sk_buff *skb,
42 const struct net_device *in,
43 const struct net_device *out,
44 const struct xt_match *match,
45 const void *matchinfo,
50 struct ip6_mh _mh, *mh;
51 const struct ip6t_mh *mhinfo = matchinfo;
53 /* Must not be a fragment. */
57 mh = skb_header_pointer(skb, protoff, sizeof(_mh), &_mh);
59 /* We've been asked to examine this packet, and we
60 can't. Hence, no choice but to drop. */
61 duprintf("Dropping evil MH tinygram.\n");
66 if (mh->ip6mh_proto != IPPROTO_NONE) {
67 duprintf("Dropping invalid MH Payload Proto: %u\n",
73 return type_match(mhinfo->types[0], mhinfo->types[1], mh->ip6mh_type,
74 !!(mhinfo->invflags & IP6T_MH_INV_TYPE));
77 /* Called when user tries to insert an entry of this type. */
79 mh_checkentry(const char *tablename,
81 const struct xt_match *match,
83 unsigned int hook_mask)
85 const struct ip6t_mh *mhinfo = matchinfo;
87 /* Must specify no unknown invflags */
88 return !(mhinfo->invflags & ~IP6T_MH_INV_MASK);
91 static struct xt_match mh_match = {
94 .checkentry = mh_checkentry,
96 .matchsize = sizeof(struct ip6t_mh),
101 static int __init ip6t_mh_init(void)
103 return xt_register_match(&mh_match);
106 static void __exit ip6t_mh_fini(void)
108 xt_unregister_match(&mh_match);
111 module_init(ip6t_mh_init);
112 module_exit(ip6t_mh_fini);