LXR linux/net/ipv6/netfilter/ip6table

   1/*
   2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
   3 *
   4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/moduleparam.h>
  14#include <linux/netfilter_ipv6/ip6_tables.h>
  15#include <linux/slab.h>
  16
  17MODULE_LICENSE("GPL");
  18MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  19MODULE_DESCRIPTION("ip6tables filter table");
  20
  21#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
  22                            (1 << NF_INET_FORWARD) | \
  23                            (1 << NF_INET_LOCAL_OUT))
  24
  25static int __net_init ip6table_filter_table_init(struct net *net);
  26
  27static const struct xt_table packet_filter = {
  28        .name           = "filter",
  29        .valid_hooks    = FILTER_VALID_HOOKS,
  30        .me             = THIS_MODULE,
  31        .af             = NFPROTO_IPV6,
  32        .priority       = NF_IP6_PRI_FILTER,
  33        .table_init     = ip6table_filter_table_init,
  34};
  35
  36/* The work comes in here from netfilter.c. */
  37static unsigned int
  38ip6table_filter_hook(void *priv, struct sk_buff *skb,
  39                     const struct nf_hook_state *state)
  40{
  41        return ip6t_do_table(skb, state, state->net->ipv6.ip6table_filter);
  42}
  43
  44static struct nf_hook_ops *filter_ops __read_mostly;
  45
  46/* Default to forward because I got too much mail already. */
  47static bool forward = true;
  48module_param(forward, bool, 0000);
  49
  50static int __net_init ip6table_filter_table_init(struct net *net)
  51{
  52        struct ip6t_replace *repl;
  53        int err;
  54
  55        if (net->ipv6.ip6table_filter)
  56                return 0;
  57
  58        repl = ip6t_alloc_initial_table(&packet_filter);
  59        if (repl == NULL)
  60                return -ENOMEM;
  61        /* Entry 1 is the FORWARD hook */
  62        ((struct ip6t_standard *)repl->entries)[1].target.verdict =
  63                forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
  64
  65        err = ip6t_register_table(net, &packet_filter, repl, filter_ops,
  66                                  &net->ipv6.ip6table_filter);
  67        kfree(repl);
  68        return err;
  69}
  70
  71static int __net_init ip6table_filter_net_init(struct net *net)
  72{
  73        if (net == &init_net || !forward)
  74                return ip6table_filter_table_init(net);
  75
  76        return 0;
  77}
  78
  79static void __net_exit ip6table_filter_net_exit(struct net *net)
  80{
  81        if (!net->ipv6.ip6table_filter)
  82                return;
  83        ip6t_unregister_table(net, net->ipv6.ip6table_filter, filter_ops);
  84        net->ipv6.ip6table_filter = NULL;
  85}
  86
  87static struct pernet_operations ip6table_filter_net_ops = {
  88        .init = ip6table_filter_net_init,
  89        .exit = ip6table_filter_net_exit,
  90};
  91
  92static int __init ip6table_filter_init(void)
  93{
  94        int ret;
  95
  96        filter_ops = xt_hook_ops_alloc(&packet_filter, ip6table_filter_hook);
  97        if (IS_ERR(filter_ops))
  98                return PTR_ERR(filter_ops);
  99
 100        ret = register_pernet_subsys(&ip6table_filter_net_ops);
 101        if (ret < 0)
 102                kfree(filter_ops);
 103
 104        return ret;
 105}
 106
 107static void __exit ip6table_filter_fini(void)
 108{
 109        unregister_pernet_subsys(&ip6table_filter_net_ops);
 110        kfree(filter_ops);
 111}
 112
 113module_init(ip6table_filter_init);
 114module_exit(ip6table_filter_fini);
 115