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Commit a0ca215a authored by Masahide NAKAMURA's avatar Masahide NAKAMURA Committed by David S. Miller
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[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: default avatarMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: default avatarYasuyuki Kozakai <kozakai@linux-ipv6.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e60a13e0
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+15 −0
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#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*/
+8 −0
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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
+1 −0
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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
+108 −0
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/*
 * 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);