/* Kernel module to match running CPU */
  
  /*
   * Might be used to distribute connections on several daemons, if
   * RPS (Remote Packet Steering) is enabled or NIC is multiqueue capable,
   * each RX queue IRQ affined to one CPU (1:1 mapping)
   *
   */
  
  /* (C) 2010 Eric Dumazet
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/module.h>
  #include <linux/skbuff.h>
  #include <linux/netfilter/xt_cpu.h>
  #include <linux/netfilter/x_tables.h>
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Eric Dumazet <eric.dumazet@gmail.com>");
  MODULE_DESCRIPTION("Xtables: CPU match");

  MODULE_ALIAS("ipt_cpu");
  MODULE_ALIAS("ip6t_cpu");

  
  static int cpu_mt_check(const struct xt_mtchk_param *par)
  {
  	const struct xt_cpu_info *info = par->matchinfo;
  
  	if (info->invert & ~1)
  		return -EINVAL;
  	return 0;
  }
  
  static bool cpu_mt(const struct sk_buff *skb, struct xt_action_param *par)
  {
  	const struct xt_cpu_info *info = par->matchinfo;
  
  	return (info->cpu == smp_processor_id()) ^ info->invert;
  }
  
  static struct xt_match cpu_mt_reg __read_mostly = {
  	.name       = "cpu",
  	.revision   = 0,
  	.family     = NFPROTO_UNSPEC,
  	.checkentry = cpu_mt_check,
  	.match      = cpu_mt,
  	.matchsize  = sizeof(struct xt_cpu_info),
  	.me         = THIS_MODULE,
  };
  
  static int __init cpu_mt_init(void)
  {
  	return xt_register_match(&cpu_mt_reg);
  }
  
  static void __exit cpu_mt_exit(void)
  {
  	xt_unregister_match(&cpu_mt_reg);
  }
  
  module_init(cpu_mt_init);
  module_exit(cpu_mt_exit);