net/ipv6/netfilter/ip6table_security.c

   1 /*
   2  * "security" table for IPv6
   3  *
   4  * This is for use by Mandatory Access Control (MAC) security models,
   5  * which need to be able to manage security policy in separate context
   6  * to DAC.
   7  *
   8  * Based on iptable_mangle.c
   9  *
  10  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
  11  * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
  12  * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18 #include <linux/module.h>
  19 #include <linux/netfilter_ipv6/ip6_tables.h>
  20 #include <linux/slab.h>
  21
  22 MODULE_LICENSE("GPL");
  23 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
  24 MODULE_DESCRIPTION("ip6tables security table, for MAC rules");
  25
  26 #define SECURITY_VALID_HOOKS    (1 << NF_INET_LOCAL_IN) | \
  27                                 (1 << NF_INET_FORWARD) | \
  28                                 (1 << NF_INET_LOCAL_OUT)
  29
  30 static int __net_init ip6table_security_table_init(struct net *net);
  31
  32 static const struct xt_table security_table = {
  33         .name           = "security",
  34         .valid_hooks    = SECURITY_VALID_HOOKS,
  35         .me             = THIS_MODULE,
  36         .af             = NFPROTO_IPV6,
  37         .priority       = NF_IP6_PRI_SECURITY,
  38         .table_init     = ip6table_security_table_init,
  39 };
  40
  41 static unsigned int
  42 ip6table_security_hook(void *priv, struct sk_buff *skb,
  43                        const struct nf_hook_state *state)
  44 {
  45         return ip6t_do_table(skb, state, state->net->ipv6.ip6table_security);
  46 }
  47
  48 static struct nf_hook_ops *sectbl_ops __read_mostly;
  49
  50 static int __net_init ip6table_security_table_init(struct net *net)
  51 {
  52         struct ip6t_replace *repl;
  53         int ret;
  54
  55         if (net->ipv6.ip6table_security)
  56                 return 0;
  57
  58         repl = ip6t_alloc_initial_table(&security_table);
  59         if (repl == NULL)
  60                 return -ENOMEM;
  61         ret = ip6t_register_table(net, &security_table, repl, sectbl_ops,
  62                                   &net->ipv6.ip6table_security);
  63         kfree(repl);
  64         return ret;
  65 }
  66
  67 static void __net_exit ip6table_security_net_exit(struct net *net)
  68 {
  69         if (!net->ipv6.ip6table_security)
  70                 return;
  71         ip6t_unregister_table(net, net->ipv6.ip6table_security, sectbl_ops);
  72         net->ipv6.ip6table_security = NULL;
  73 }
  74
  75 static struct pernet_operations ip6table_security_net_ops = {
  76         .exit = ip6table_security_net_exit,
  77 };
  78
  79 static int __init ip6table_security_init(void)
  80 {
  81         int ret;
  82
  83         sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
  84         if (IS_ERR(sectbl_ops))
  85                 return PTR_ERR(sectbl_ops);
  86
  87         ret = register_pernet_subsys(&ip6table_security_net_ops);
  88         if (ret < 0) {
  89                 kfree(sectbl_ops);
  90                 return ret;
  91         }
  92
  93         ret = ip6table_security_table_init(&init_net);
  94         if (ret) {
  95                 unregister_pernet_subsys(&ip6table_security_net_ops);
  96                 kfree(sectbl_ops);
  97         }
  98         return ret;
  99 }
 100
 101 static void __exit ip6table_security_fini(void)
 102 {
 103         unregister_pernet_subsys(&ip6table_security_net_ops);
 104         kfree(sectbl_ops);
 105 }
 106
 107 module_init(ip6table_security_init);
 108 module_exit(ip6table_security_fini);