SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/ipv6/netfilter/ip6table_filter.c

   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
  16 MODULE_LICENSE("GPL");
  17 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  18 MODULE_DESCRIPTION("ip6tables filter table");
  19
  20 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
  21                             (1 << NF_INET_FORWARD) | \
  22                             (1 << NF_INET_LOCAL_OUT))
  23
  24 static struct
  25 {
  26         struct ip6t_replace repl;
  27         struct ip6t_standard entries[3];
  28         struct ip6t_error term;
  29 } initial_table __net_initdata = {
  30         .repl = {
  31                 .name = "filter",
  32                 .valid_hooks = FILTER_VALID_HOOKS,
  33                 .num_entries = 4,
  34                 .size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
  35                 .hook_entry = {
  36                         [NF_INET_LOCAL_IN] = 0,
  37                         [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
  38                         [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
  39                 },
  40                 .underflow = {
  41                         [NF_INET_LOCAL_IN] = 0,
  42                         [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
  43                         [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
  44                 },
  45         },
  46         .entries = {
  47                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* LOCAL_IN */
  48                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* FORWARD */
  49                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* LOCAL_OUT */
  50         },
  51         .term = IP6T_ERROR_INIT,                /* ERROR */
  52 };
  53
  54 static const struct xt_table packet_filter = {
  55         .name           = "filter",
  56         .valid_hooks    = FILTER_VALID_HOOKS,
  57         .me             = THIS_MODULE,
  58         .af             = NFPROTO_IPV6,
  59 };
  60
  61 /* The work comes in here from netfilter.c. */
  62 static unsigned int
  63 ip6table_filter_hook(unsigned int hook, struct sk_buff *skb,
  64                      const struct net_device *in, const struct net_device *out,
  65                      int (*okfn)(struct sk_buff *))
  66 {
  67         if (hook == NF_INET_LOCAL_OUT)
  68                 return ip6t_do_table(skb, hook, in, out,
  69                                      dev_net(out)->ipv6.ip6table_filter);
  70
  71         /* INPUT/FORWARD: */
  72         return ip6t_do_table(skb, hook, in, out,
  73                              dev_net(in)->ipv6.ip6table_filter);
  74 }
  75
  76 static struct nf_hook_ops ip6t_ops[] __read_mostly = {
  77         {
  78                 .hook           = ip6table_filter_hook,
  79                 .owner          = THIS_MODULE,
  80                 .pf             = NFPROTO_IPV6,
  81                 .hooknum        = NF_INET_LOCAL_IN,
  82                 .priority       = NF_IP6_PRI_FILTER,
  83         },
  84         {
  85                 .hook           = ip6table_filter_hook,
  86                 .owner          = THIS_MODULE,
  87                 .pf             = NFPROTO_IPV6,
  88                 .hooknum        = NF_INET_FORWARD,
  89                 .priority       = NF_IP6_PRI_FILTER,
  90         },
  91         {
  92                 .hook           = ip6table_filter_hook,
  93                 .owner          = THIS_MODULE,
  94                 .pf             = NFPROTO_IPV6,
  95                 .hooknum        = NF_INET_LOCAL_OUT,
  96                 .priority       = NF_IP6_PRI_FILTER,
  97         },
  98 };
  99
 100 /* Default to forward because I got too much mail already. */
 101 static int forward = NF_ACCEPT;
 102 module_param(forward, bool, 0000);
 103
 104 static int __net_init ip6table_filter_net_init(struct net *net)
 105 {
 106         /* Register table */
 107         net->ipv6.ip6table_filter =
 108                 ip6t_register_table(net, &packet_filter, &initial_table.repl);
 109         if (IS_ERR(net->ipv6.ip6table_filter))
 110                 return PTR_ERR(net->ipv6.ip6table_filter);
 111         return 0;
 112 }
 113
 114 static void __net_exit ip6table_filter_net_exit(struct net *net)
 115 {
 116         ip6t_unregister_table(net, net->ipv6.ip6table_filter);
 117 }
 118
 119 static struct pernet_operations ip6table_filter_net_ops = {
 120         .init = ip6table_filter_net_init,
 121         .exit = ip6table_filter_net_exit,
 122 };
 123
 124 static int __init ip6table_filter_init(void)
 125 {
 126         int ret;
 127
 128         if (forward < 0 || forward > NF_MAX_VERDICT) {
 129                 printk("iptables forward must be 0 or 1\n");
 130                 return -EINVAL;
 131         }
 132
 133         /* Entry 1 is the FORWARD hook */
 134         initial_table.entries[1].target.verdict = -forward - 1;
 135
 136         ret = register_pernet_subsys(&ip6table_filter_net_ops);
 137         if (ret < 0)
 138                 return ret;
 139
 140         /* Register hooks */
 141         ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
 142         if (ret < 0)
 143                 goto cleanup_table;
 144
 145         return ret;
 146
 147  cleanup_table:
 148         unregister_pernet_subsys(&ip6table_filter_net_ops);
 149         return ret;
 150 }
 151
 152 static void __exit ip6table_filter_fini(void)
 153 {
 154         nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
 155         unregister_pernet_subsys(&ip6table_filter_net_ops);
 156 }
 157
 158 module_init(ip6table_filter_init);
 159 module_exit(ip6table_filter_fini);