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/* IP tables module for matching the value of the IPv4 DSCP field
*
* ipt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp
*
* (C) 2002 by Harald Welte <laforge@gnumonks.org>
*
* This software is distributed under the terms GNU GPL
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter_ipv4/ipt_dscp.h>
#include <linux/netfilter_ipv4/ip_tables.h>
MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
MODULE_DESCRIPTION("IP tables DSCP matching module");
MODULE_LICENSE("GPL");
static int match(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const void *matchinfo,
int offset, const void *hdr, u_int16_t datalen,
int *hotdrop)
{
const struct ipt_dscp_info *info = matchinfo;
const struct iphdr *iph = skb->nh.iph;
u_int8_t sh_dscp = ((info->dscp << IPT_DSCP_SHIFT) & IPT_DSCP_MASK);
return ((iph->tos&IPT_DSCP_MASK) == sh_dscp) ^ info->invert;
}
static int checkentry(const char *tablename, const struct ipt_ip *ip,
void *matchinfo, unsigned int matchsize,
unsigned int hook_mask)
{
if (matchsize != IPT_ALIGN(sizeof(struct ipt_dscp_info)))
return 0;
return 1;
}
static struct ipt_match dscp_match = { { NULL, NULL }, "dscp", &match,
&checkentry, NULL, THIS_MODULE };
static int __init init(void)
{
return ipt_register_match(&dscp_match);
}
static void __exit fini(void)
{
ipt_unregister_match(&dscp_match);
}
module_init(init);
module_exit(fini);
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