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
  21 MODULE_LICENSE("GPL");
  22 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
  23 MODULE_DESCRIPTION("ip6tables security table, for MAC rules");
  24
  25 #define SECURITY_VALID_HOOKS    (1 << NF_INET_LOCAL_IN) | \
  26                                 (1 << NF_INET_FORWARD) | \
  27                                 (1 << NF_INET_LOCAL_OUT)
  28
  29 static const struct xt_table security_table = {
  30         .name           = "security",
  31         .valid_hooks    = SECURITY_VALID_HOOKS,
  32         .me             = THIS_MODULE,
  33         .af             = NFPROTO_IPV6,
  34         .priority       = NF_IP6_PRI_SECURITY,
  35 };
  36
  37 static unsigned int
  38 ip6table_security_hook(unsigned int hook, struct sk_buff *skb,
  39                        const struct net_device *in,
  40                        const struct net_device *out,
  41                        int (*okfn)(struct sk_buff *))
  42 {
  43         const struct net *net = dev_net((in != NULL) ? in : out);
  44
  45         return ip6t_do_table(skb, hook, in, out, net->ipv6.ip6table_security);
  46 }
  47
  48 static struct nf_hook_ops *sectbl_ops __read_mostly;
  49
  50 static int __net_init ip6table_security_net_init(struct net *net)
  51 {
  52         struct ip6t_replace *repl;
  53
  54         repl = ip6t_alloc_initial_table(&security_table);
  55         if (repl == NULL)
  56                 return -ENOMEM;
  57         net->ipv6.ip6table_security =
  58                 ip6t_register_table(net, &security_table, repl);
  59         kfree(repl);
  60         if (IS_ERR(net->ipv6.ip6table_security))
  61                 return PTR_ERR(net->ipv6.ip6table_security);
  62
  63         return 0;
  64 }
  65
  66 static void __net_exit ip6table_security_net_exit(struct net *net)
  67 {
  68         ip6t_unregister_table(net, net->ipv6.ip6table_security);
  69 }
  70
  71 static struct pernet_operations ip6table_security_net_ops = {
  72         .init = ip6table_security_net_init,
  73         .exit = ip6table_security_net_exit,
  74 };
  75
  76 static int __init ip6table_security_init(void)
  77 {
  78         int ret;
  79
  80         ret = register_pernet_subsys(&ip6table_security_net_ops);
  81         if (ret < 0)
  82                 return ret;
  83
  84         sectbl_ops = xt_hook_link(&security_table, ip6table_security_hook);
  85         if (IS_ERR(sectbl_ops)) {
  86                 ret = PTR_ERR(sectbl_ops);
  87                 goto cleanup_table;
  88         }
  89
  90         return ret;
  91
  92 cleanup_table:
  93         unregister_pernet_subsys(&ip6table_security_net_ops);
  94         return ret;
  95 }
  96
  97 static void __exit ip6table_security_fini(void)
  98 {
  99         xt_hook_unlink(&security_table, sectbl_ops);
 100         unregister_pernet_subsys(&ip6table_security_net_ops);
 101 }
 102
 103 module_init(ip6table_security_init);
 104 module_exit(ip6table_security_fini);