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