64 lines
1.6 KiB
C
64 lines
1.6 KiB
C
/* IP tables module for matching the value of the IPv4 DSCP field
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*
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* ipt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp
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*
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* (C) 2002 by Harald Welte <laforge@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter_ipv4/ipt_dscp.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
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MODULE_DESCRIPTION("iptables DSCP matching module");
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MODULE_LICENSE("GPL");
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static int match(const struct sk_buff *skb, const struct net_device *in,
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const struct net_device *out, const void *matchinfo,
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int offset, unsigned int protoff, int *hotdrop)
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{
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const struct ipt_dscp_info *info = matchinfo;
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const struct iphdr *iph = skb->nh.iph;
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u_int8_t sh_dscp = ((info->dscp << IPT_DSCP_SHIFT) & IPT_DSCP_MASK);
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return ((iph->tos&IPT_DSCP_MASK) == sh_dscp) ^ info->invert;
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}
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static int checkentry(const char *tablename, const void *ip,
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void *matchinfo, unsigned int matchsize,
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unsigned int hook_mask)
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{
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if (matchsize != IPT_ALIGN(sizeof(struct ipt_dscp_info)))
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return 0;
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return 1;
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}
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static struct ipt_match dscp_match = {
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.name = "dscp",
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.match = &match,
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.checkentry = &checkentry,
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.me = THIS_MODULE,
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};
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static int __init init(void)
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{
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return ipt_register_match(&dscp_match);
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}
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static void __exit fini(void)
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{
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ipt_unregister_match(&dscp_match);
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}
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module_init(init);
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module_exit(fini);
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