net/ipv4/netfilter/ipt_tos.c

   1 /* Kernel module to match TOS values. */
   2
   3 /* (C) 1999-2001 Paul `Rusty' Russell
   4  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/skbuff.h>
  13
  14 #include <linux/netfilter_ipv4/ipt_tos.h>
  15 #include <linux/netfilter_ipv4/ip_tables.h>
  16
  17 MODULE_LICENSE("GPL");
  18 MODULE_DESCRIPTION("iptables TOS match module");
  19
  20 static int
  21 match(const struct sk_buff *skb,
  22       const struct net_device *in,
  23       const struct net_device *out,
  24       const struct xt_match *match,
  25       const void *matchinfo,
  26       int offset,
  27       unsigned int protoff,
  28       int *hotdrop)
  29 {
  30         const struct ipt_tos_info *info = matchinfo;
  31
  32         return (skb->nh.iph->tos == info->tos) ^ info->invert;
  33 }
  34
  35 static struct ipt_match tos_match = {
  36         .name           = "tos",
  37         .match          = match,
  38         .matchsize      = sizeof(struct ipt_tos_info),
  39         .me             = THIS_MODULE,
  40 };
  41
  42 static int __init init(void)
  43 {
  44         return ipt_register_match(&tos_match);
  45 }
  46
  47 static void __exit fini(void)
  48 {
  49         ipt_unregister_match(&tos_match);
  50 }
  51
  52 module_init(init);
  53 module_exit(fini);