net/ipv6/netfilter/ip6table_security.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * "security" table for IPv6
   4  *
   5  * This is for use by Mandatory Access Control (MAC) security models,
   6  * which need to be able to manage security policy in separate context
   7  * to DAC.
   8  *
   9  * Based on iptable_mangle.c
  10  *
  11  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
  12  * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
  13  * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
  14  */
  15 #include <linux/module.h>
  16 #include <linux/netfilter_ipv6/ip6_tables.h>
  17 #include <linux/slab.h>
  18
  19 MODULE_LICENSE("GPL");
  20 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
  21 MODULE_DESCRIPTION("ip6tables security table, for MAC rules");
  22
  23 #define SECURITY_VALID_HOOKS    (1 << NF_INET_LOCAL_IN) | \
  24                                 (1 << NF_INET_FORWARD) | \
  25                                 (1 << NF_INET_LOCAL_OUT)
  26
  27 static int __net_init ip6table_security_table_init(struct net *net);
  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         .table_init     = ip6table_security_table_init,
  36 };
  37
  38 static unsigned int
  39 ip6table_security_hook(void *priv, struct sk_buff *skb,
  40                        const struct nf_hook_state *state)
  41 {
  42         return ip6t_do_table(skb, state, priv);
  43 }
  44
  45 static struct nf_hook_ops *sectbl_ops __read_mostly;
  46
  47 static int __net_init ip6table_security_table_init(struct net *net)
  48 {
  49         struct ip6t_replace *repl;
  50         int ret;
  51
  52         repl = ip6t_alloc_initial_table(&security_table);
  53         if (repl == NULL)
  54                 return -ENOMEM;
  55         ret = ip6t_register_table(net, &security_table, repl, sectbl_ops);
  56         kfree(repl);
  57         return ret;
  58 }
  59
  60 static void __net_exit ip6table_security_net_pre_exit(struct net *net)
  61 {
  62         ip6t_unregister_table_pre_exit(net, "security");
  63 }
  64
  65 static void __net_exit ip6table_security_net_exit(struct net *net)
  66 {
  67         ip6t_unregister_table_exit(net, "security");
  68 }
  69
  70 static struct pernet_operations ip6table_security_net_ops = {
  71         .pre_exit = ip6table_security_net_pre_exit,
  72         .exit = ip6table_security_net_exit,
  73 };
  74
  75 static int __init ip6table_security_init(void)
  76 {
  77         int ret;
  78
  79         sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
  80         if (IS_ERR(sectbl_ops))
  81                 return PTR_ERR(sectbl_ops);
  82
  83         ret = register_pernet_subsys(&ip6table_security_net_ops);
  84         if (ret < 0) {
  85                 kfree(sectbl_ops);
  86                 return ret;
  87         }
  88
  89         ret = ip6table_security_table_init(&init_net);
  90         if (ret) {
  91                 unregister_pernet_subsys(&ip6table_security_net_ops);
  92                 kfree(sectbl_ops);
  93         }
  94         return ret;
  95 }
  96
  97 static void __exit ip6table_security_fini(void)
  98 {
  99         unregister_pernet_subsys(&ip6table_security_net_ops);
 100         kfree(sectbl_ops);
 101 }
 102
 103 module_init(ip6table_security_init);
 104 module_exit(ip6table_security_fini);