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/ip.h>
  12 #include <linux/module.h>
  13 #include <linux/skbuff.h>
  14
  15 #include <linux/netfilter_ipv4/ipt_tos.h>
  16 #include <linux/netfilter/x_tables.h>
  17
  18 MODULE_LICENSE("GPL");
  19 MODULE_DESCRIPTION("iptables TOS match module");
  20
  21 static int
  22 match(const struct sk_buff *skb,
  23       const struct net_device *in,
  24       const struct net_device *out,
  25       const struct xt_match *match,
  26       const void *matchinfo,
  27       int offset,
  28       unsigned int protoff,
  29       bool *hotdrop)
  30 {
  31         const struct ipt_tos_info *info = matchinfo;
  32
  33         return (ip_hdr(skb)->tos == info->tos) ^ info->invert;
  34 }
  35
  36 static struct xt_match tos_match = {
  37         .name           = "tos",
  38         .family         = AF_INET,
  39         .match          = match,
  40         .matchsize      = sizeof(struct ipt_tos_info),
  41         .me             = THIS_MODULE,
  42 };
  43
  44 static int __init ipt_multiport_init(void)
  45 {
  46         return xt_register_match(&tos_match);
  47 }
  48
  49 static void __exit ipt_multiport_fini(void)
  50 {
  51         xt_unregister_match(&tos_match);
  52 }
  53
  54 module_init(ipt_multiport_init);
  55 module_exit(ipt_multiport_fini);