[NETFILTER]: ip6_tables: support MH match

This introduces match for Mobility Header (MH) described by Mobile IPv6
specification (RFC3775). User can specify the MH type or its range to be
matched.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: Yasuyuki Kozakai <kozakai@linux-ipv6.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Masahide NAKAMURA 2007-02-07 15:12:57 -08:00 committed by David S. Miller
parent e60a13e030
commit a0ca215a73
4 changed files with 132 additions and 0 deletions

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@ -0,0 +1,15 @@
#ifndef _IP6T_MH_H
#define _IP6T_MH_H
/* MH matching stuff */
struct ip6t_mh
{
u_int8_t types[2]; /* MH type range */
u_int8_t invflags; /* Inverse flags */
};
/* Values for "invflags" field in struct ip6t_mh. */
#define IP6T_MH_INV_TYPE 0x01 /* Invert the sense of type. */
#define IP6T_MH_INV_MASK 0x01 /* All possible flags. */
#endif /*_IP6T_MH_H*/

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@ -114,6 +114,14 @@ config IP6_NF_MATCH_AH
To compile it as a module, choose M here. If unsure, say N.
config IP6_NF_MATCH_MH
tristate "MH match support"
depends on IP6_NF_IPTABLES
help
This module allows one to match MH packets.
To compile it as a module, choose M here. If unsure, say N.
config IP6_NF_MATCH_EUI64
tristate "EUI64 address check"
depends on IP6_NF_IPTABLES

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@ -19,6 +19,7 @@ obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_LOG.o
obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o
# objects for l3 independent conntrack
nf_conntrack_ipv6-objs := nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o nf_conntrack_reasm.o

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@ -0,0 +1,108 @@
/*
* Copyright (C)2006 USAGI/WIDE Project
*
* 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.
*
* Author:
* Masahide NAKAMURA @USAGI <masahide.nakamura.cz@hitachi.com>
*
* Based on net/netfilter/xt_tcpudp.c
*
*/
#include <linux/types.h>
#include <linux/module.h>
#include <net/ip.h>
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include <net/mip6.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv6/ip6t_mh.h>
MODULE_DESCRIPTION("ip6t_tables match for MH");
MODULE_LICENSE("GPL");
#ifdef DEBUG_IP_FIREWALL_USER
#define duprintf(format, args...) printk(format , ## args)
#else
#define duprintf(format, args...)
#endif
/* Returns 1 if the type is matched by the range, 0 otherwise */
static inline int
type_match(u_int8_t min, u_int8_t max, u_int8_t type, int invert)
{
int ret;
ret = (type >= min && type <= max) ^ invert;
return ret;
}
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const struct xt_match *match,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
struct ip6_mh _mh, *mh;
const struct ip6t_mh *mhinfo = matchinfo;
/* Must not be a fragment. */
if (offset)
return 0;
mh = skb_header_pointer(skb, protoff, sizeof(_mh), &_mh);
if (mh == NULL) {
/* We've been asked to examine this packet, and we
can't. Hence, no choice but to drop. */
duprintf("Dropping evil MH tinygram.\n");
*hotdrop = 1;
return 0;
}
return type_match(mhinfo->types[0], mhinfo->types[1], mh->ip6mh_type,
!!(mhinfo->invflags & IP6T_MH_INV_TYPE));
}
/* Called when user tries to insert an entry of this type. */
static int
mh_checkentry(const char *tablename,
const void *entry,
const struct xt_match *match,
void *matchinfo,
unsigned int hook_mask)
{
const struct ip6t_mh *mhinfo = matchinfo;
/* Must specify no unknown invflags */
return !(mhinfo->invflags & ~IP6T_MH_INV_MASK);
}
static struct xt_match mh_match = {
.name = "mh",
.family = AF_INET6,
.checkentry = mh_checkentry,
.match = match,
.matchsize = sizeof(struct ip6t_mh),
.proto = IPPROTO_MH,
.me = THIS_MODULE,
};
static int __init ip6t_mh_init(void)
{
return xt_register_match(&mh_match);
}
static void __exit ip6t_mh_fini(void)
{
xt_unregister_match(&mh_match);
}
module_init(ip6t_mh_init);
module_exit(ip6t_mh_fini);