1 /* IP tables module for matching the value of the IPv4 DSCP field
3 * ipt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp
5 * (C) 2002 by Harald Welte <laforge@netfilter.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/skbuff.h>
15 #include <linux/netfilter_ipv4/ipt_dscp.h>
16 #include <linux/netfilter_ipv4/ip_tables.h>
18 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
19 MODULE_DESCRIPTION("iptables DSCP matching module");
20 MODULE_LICENSE("GPL");
22 static int match(const struct sk_buff
*skb
, const struct net_device
*in
,
23 const struct net_device
*out
, const void *matchinfo
,
24 int offset
, int *hotdrop
)
26 const struct ipt_dscp_info
*info
= matchinfo
;
27 const struct iphdr
*iph
= skb
->nh
.iph
;
29 u_int8_t sh_dscp
= ((info
->dscp
<< IPT_DSCP_SHIFT
) & IPT_DSCP_MASK
);
31 return ((iph
->tos
&IPT_DSCP_MASK
) == sh_dscp
) ^ info
->invert
;
34 static int checkentry(const char *tablename
, const struct ipt_ip
*ip
,
35 void *matchinfo
, unsigned int matchsize
,
36 unsigned int hook_mask
)
38 if (matchsize
!= IPT_ALIGN(sizeof(struct ipt_dscp_info
)))
44 static struct ipt_match dscp_match
= {
47 .checkentry
= &checkentry
,
51 static int __init
init(void)
53 return ipt_register_match(&dscp_match
);
56 static void __exit
fini(void)
58 ipt_unregister_match(&dscp_match
);