Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* This is a module which is used for setting the TOS field of a packet. */

/* (C) 1999-2001 Paul `Rusty' Russell

 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>

 *

 * 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.

 */

#include <linux/module.h>

#include <linux/skbuff.h>

#include <linux/ip.h>

#include <net/checksum.h>

#include <linux/netfilter/x_tables.h>

#include <linux/netfilter_ipv4/ipt_TOS.h>

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");

MODULE_DESCRIPTION("iptables TOS mangling module");

static unsigned int

target(struct sk_buff *skb,

       const struct net_device *in,

       const struct net_device *out,

       unsigned int hooknum,

       const struct xt_target *target,

       const void *targinfo)

{

        const struct ipt_tos_target_info *tosinfo = targinfo;

        struct iphdr *iph = ip_hdr(skb);

        if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {

                __u8 oldtos;

                if (!skb_make_writable(skb, sizeof(struct iphdr)))

                        return NF_DROP;

                iph = ip_hdr(skb);

                oldtos = iph->tos;

                iph->tos = (iph->tos & IPTOS_PREC_MASK) | tosinfo->tos;

                nf_csum_replace2(&iph->check, htons(oldtos), htons(iph->tos));

        }

        return XT_CONTINUE;

}

static bool

checkentry(const char *tablename,

           const void *e_void,

           const struct xt_target *target,

           void *targinfo,

           unsigned int hook_mask)

{

        const u_int8_t tos = ((struct ipt_tos_target_info *)targinfo)->tos;

        if (tos != IPTOS_LOWDELAY

            && tos != IPTOS_THROUGHPUT

            && tos != IPTOS_RELIABILITY

            && tos != IPTOS_MINCOST

            && tos != IPTOS_NORMALSVC) {

                printk(KERN_WARNING "TOS: bad tos value %#x\n", tos);

                return false;

        }

        return true;

}

static struct xt_target ipt_tos_reg __read_mostly = {

        .name           = "TOS",

        .family         = AF_INET,

        .target         = target,

        .targetsize     = sizeof(struct ipt_tos_target_info),

        .table          = "mangle",

        .checkentry     = checkentry,

        .me             = THIS_MODULE,

};

static int __init ipt_tos_init(void)

{

        return xt_register_target(&ipt_tos_reg);

}

static void __exit ipt_tos_fini(void)

{

        xt_unregister_target(&ipt_tos_reg);

}

module_init(ipt_tos_init);

module_exit(ipt_tos_fini);