net/netfilter/xt_MARK.c

   1 /*
   2  *      xt_MARK - Netfilter module to modify the NFMARK field of an skb
   3  *
   4  *      (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
   5  *      Copyright © CC Computer Consultants GmbH, 2007 - 2008
   6  *      Jan Engelhardt <jengelh@computergmbh.de>
   7  *
   8  *      This program is free software; you can redistribute it and/or modify
   9  *      it under the terms of the GNU General Public License version 2 as
  10  *      published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/ip.h>
  16 #include <net/checksum.h>
  17
  18 #include <linux/netfilter/x_tables.h>
  19 #include <linux/netfilter/xt_MARK.h>
  20
  21 MODULE_LICENSE("GPL");
  22 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
  23 MODULE_DESCRIPTION("Xtables: packet mark modification");
  24 MODULE_ALIAS("ipt_MARK");
  25 MODULE_ALIAS("ip6t_MARK");
  26
  27 static unsigned int
  28 mark_tg(struct sk_buff *skb, const struct xt_target_param *par)
  29 {
  30         const struct xt_mark_tginfo2 *info = par->targinfo;
  31
  32         skb->mark = (skb->mark & ~info->mask) ^ info->mark;
  33         return XT_CONTINUE;
  34 }
  35
  36 static struct xt_target mark_tg_reg __read_mostly = {
  37         .name           = "MARK",
  38         .revision       = 2,
  39         .family         = NFPROTO_UNSPEC,
  40         .target         = mark_tg,
  41         .targetsize     = sizeof(struct xt_mark_tginfo2),
  42         .me             = THIS_MODULE,
  43 };
  44
  45 static int __init mark_tg_init(void)
  46 {
  47         return xt_register_target(&mark_tg_reg);
  48 }
  49
  50 static void __exit mark_tg_exit(void)
  51 {
  52         xt_unregister_target(&mark_tg_reg);
  53 }
  54
  55 module_init(mark_tg_init);
  56 module_exit(mark_tg_exit);