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 const struct xt_table packet_filter = {
  26        .name           = "filter",
  27        .valid_hooks    = FILTER_VALID_HOOKS,
  28        .me             = THIS_MODULE,
  29        .af             = NFPROTO_IPV6,
  30        .priority       = NF_IP6_PRI_FILTER,
  31};
  32
  33/* The work comes in here from netfilter.c. */
  34static unsigned int
  35ip6table_filter_hook(const struct nf_hook_ops *ops, struct sk_buff *skb,
  36                     const struct net_device *in, const struct net_device *out,
  37                     int (*okfn)(struct sk_buff *))
  38{
  39        const struct net *net = dev_net((in != NULL) ? in : out);
  40
  41        return ip6t_do_table(skb, ops->hooknum, in, out,
  42                             net->ipv6.ip6table_filter);
  43}
  44
  45static struct nf_hook_ops *filter_ops __read_mostly;
  46
  47/* Default to forward because I got too much mail already. */
  48static bool forward = true;
  49module_param(forward, bool, 0000);
  50
  51static int __net_init ip6table_filter_net_init(struct net *net)
  52{
  53        struct ip6t_replace *repl;
  54
  55        repl = ip6t_alloc_initial_table(&packet_filter);
  56        if (repl == NULL)
  57                return -ENOMEM;
  58        /* Entry 1 is the FORWARD hook */
  59        ((struct ip6t_standard *)repl->entries)[1].target.verdict =
  60                forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
  61
  62        net->ipv6.ip6table_filter =
  63                ip6t_register_table(net, &packet_filter, repl);
  64        kfree(repl);
  65        return PTR_ERR_OR_ZERO(net->ipv6.ip6table_filter);
  66}
  67
  68static void __net_exit ip6table_filter_net_exit(struct net *net)
  69{
  70        ip6t_unregister_table(net, net->ipv6.ip6table_filter);
  71}
  72
  73static struct pernet_operations ip6table_filter_net_ops = {
  74        .init = ip6table_filter_net_init,
  75        .exit = ip6table_filter_net_exit,
  76};
  77
  78static int __init ip6table_filter_init(void)
  79{
  80        int ret;
  81
  82        ret = register_pernet_subsys(&ip6table_filter_net_ops);
  83        if (ret < 0)
  84                return ret;
  85
  86        /* Register hooks */
  87        filter_ops = xt_hook_link(&packet_filter, ip6table_filter_hook);
  88        if (IS_ERR(filter_ops)) {
  89                ret = PTR_ERR(filter_ops);
  90                goto cleanup_table;
  91        }
  92
  93        return ret;
  94
  95 cleanup_table:
  96        unregister_pernet_subsys(&ip6table_filter_net_ops);
  97        return ret;
  98}
  99
 100static void __exit ip6table_filter_fini(void)
 101{
 102        xt_hook_unlink(&packet_filter, filter_ops);
 103        unregister_pernet_subsys(&ip6table_filter_net_ops);
 104}
 105
 106module_init(ip6table_filter_init);
 107module_exit(ip6table_filter_fini);
 108