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 const struct xt_table security_table = {
  28         .name           = "security",
  29         .valid_hooks    = SECURITY_VALID_HOOKS,
  30         .me             = THIS_MODULE,
  31         .af             = NFPROTO_IPV6,
  32         .priority       = NF_IP6_PRI_SECURITY,
  33 };
  34
  35 static unsigned int
  36 ip6table_security_hook(void *priv, struct sk_buff *skb,
  37                        const struct nf_hook_state *state)
  38 {
  39         return ip6t_do_table(skb, state, priv);
  40 }
  41
  42 static struct nf_hook_ops *sectbl_ops __read_mostly;
  43
  44 static int ip6table_security_table_init(struct net *net)
  45 {
  46         struct ip6t_replace *repl;
  47         int ret;
  48
  49         repl = ip6t_alloc_initial_table(&security_table);
  50         if (repl == NULL)
  51                 return -ENOMEM;
  52         ret = ip6t_register_table(net, &security_table, repl, sectbl_ops);
  53         kfree(repl);
  54         return ret;
  55 }
  56
  57 static void __net_exit ip6table_security_net_pre_exit(struct net *net)
  58 {
  59         ip6t_unregister_table_pre_exit(net, "security");
  60 }
  61
  62 static void __net_exit ip6table_security_net_exit(struct net *net)
  63 {
  64         ip6t_unregister_table_exit(net, "security");
  65 }
  66
  67 static struct pernet_operations ip6table_security_net_ops = {
  68         .pre_exit = ip6table_security_net_pre_exit,
  69         .exit = ip6table_security_net_exit,
  70 };
  71
  72 static int __init ip6table_security_init(void)
  73 {
  74         int ret = xt_register_template(&security_table,
  75                                        ip6table_security_table_init);
  76
  77         if (ret < 0)
  78                 return ret;
  79
  80         sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
  81         if (IS_ERR(sectbl_ops)) {
  82                 xt_unregister_template(&security_table);
  83                 return PTR_ERR(sectbl_ops);
  84         }
  85
  86         ret = register_pernet_subsys(&ip6table_security_net_ops);
  87         if (ret < 0) {
  88                 kfree(sectbl_ops);
  89                 xt_unregister_template(&security_table);
  90                 return ret;
  91         }
  92
  93         return ret;
  94 }
  95
  96 static void __exit ip6table_security_fini(void)
  97 {
  98         unregister_pernet_subsys(&ip6table_security_net_ops);
  99         xt_unregister_template(&security_table);
 100         kfree(sectbl_ops);
 101 }
 102
 103 module_init(ip6table_security_init);
 104 module_exit(ip6table_security_fini);