Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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 bool

type_match(u_int8_t min, u_int8_t max, u_int8_t type, bool invert)

{

        return (type >= min && type <= max) ^ invert;

}

static bool

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,

         bool *hotdrop)

{

        struct ip6_mh _mh;

        const struct ip6_mh *mh;

        const struct ip6t_mh *mhinfo = matchinfo;

        /* Must not be a fragment. */

        if (offset)

                return false;

        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 = true;

                return false;

        }

        if (mh->ip6mh_proto != IPPROTO_NONE) {

                duprintf("Dropping invalid MH Payload Proto: %u\n",

                         mh->ip6mh_proto);

                *hotdrop = true;

                return false;

        }

        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 bool

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 __read_mostly = {

        .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);