/*
   * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
   *
   * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
   *
   * 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/moduleparam.h>
  #include <linux/netfilter_ipv6/ip6_tables.h>

  #include <linux/slab.h>

  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  MODULE_DESCRIPTION("ip6tables filter table");

  #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
  			    (1 << NF_INET_FORWARD) | \
  			    (1 << NF_INET_LOCAL_OUT))

  static int __net_init ip6table_filter_table_init(struct net *net);

  static const struct xt_table packet_filter = {

  	.name		= "filter",
  	.valid_hooks	= FILTER_VALID_HOOKS,

  	.me		= THIS_MODULE,

  	.af		= NFPROTO_IPV6,

  	.priority	= NF_IP6_PRI_FILTER,

  	.table_init	= ip6table_filter_table_init,

  };
  
  /* The work comes in here from netfilter.c. */
  static unsigned int

  ip6table_filter_hook(void *priv, struct sk_buff *skb,

  		     const struct nf_hook_state *state)

  {

  	return ip6t_do_table(skb, state, state->net->ipv6.ip6table_filter);

  }

  static struct nf_hook_ops *filter_ops __read_mostly;

  
  /* Default to forward because I got too much mail already. */

  static bool forward = true;

  module_param(forward, bool, 0000);

  static int __net_init ip6table_filter_table_init(struct net *net)

  {

  	struct ip6t_replace *repl;

  	int err;

  	if (net->ipv6.ip6table_filter)
  		return 0;

  	repl = ip6t_alloc_initial_table(&packet_filter);
  	if (repl == NULL)
  		return -ENOMEM;
  	/* Entry 1 is the FORWARD hook */
  	((struct ip6t_standard *)repl->entries)[1].target.verdict =

  		forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;

  	err = ip6t_register_table(net, &packet_filter, repl, filter_ops,
  				  &net->ipv6.ip6table_filter);

  	kfree(repl);

  	return err;

  }

  static int __net_init ip6table_filter_net_init(struct net *net)
  {
  	if (net == &init_net || !forward)
  		return ip6table_filter_table_init(net);
  
  	return 0;
  }

  static void __net_exit ip6table_filter_net_exit(struct net *net)
  {

  	if (!net->ipv6.ip6table_filter)
  		return;

  	ip6t_unregister_table(net, net->ipv6.ip6table_filter, filter_ops);

  	net->ipv6.ip6table_filter = NULL;

  }
  
  static struct pernet_operations ip6table_filter_net_ops = {
  	.init = ip6table_filter_net_init,
  	.exit = ip6table_filter_net_exit,
  };

  static int __init ip6table_filter_init(void)

  {
  	int ret;

  	filter_ops = xt_hook_ops_alloc(&packet_filter, ip6table_filter_hook);
  	if (IS_ERR(filter_ops))
  		return PTR_ERR(filter_ops);

  	ret = register_pernet_subsys(&ip6table_filter_net_ops);
  	if (ret < 0)

  		kfree(filter_ops);

  	return ret;

  }

  static void __exit ip6table_filter_fini(void)

  {

  	unregister_pernet_subsys(&ip6table_filter_net_ops);

  	kfree(filter_ops);

  }

  module_init(ip6table_filter_init);
  module_exit(ip6table_filter_fini);