LXR linux/net/ipv6/netfilter/ip6table

   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
  19MODULE_LICENSE("GPL");
  20MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
  21MODULE_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
  27static int __net_init ip6table_security_table_init(struct net *net);
  28
  29static 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
  38static unsigned int
  39ip6table_security_hook(void *priv, struct sk_buff *skb,
  40                       const struct nf_hook_state *state)
  41{
  42        return ip6t_do_table(skb, state, state->net->ipv6.ip6table_security);
  43}
  44
  45static struct nf_hook_ops *sectbl_ops __read_mostly;
  46
  47static int __net_init ip6table_security_table_init(struct net *net)
  48{
  49        struct ip6t_replace *repl;
  50        int ret;
  51
  52        if (net->ipv6.ip6table_security)
  53                return 0;
  54
  55        repl = ip6t_alloc_initial_table(&security_table);
  56        if (repl == NULL)
  57                return -ENOMEM;
  58        ret = ip6t_register_table(net, &security_table, repl, sectbl_ops,
  59                                  &net->ipv6.ip6table_security);
  60        kfree(repl);
  61        return ret;
  62}
  63
  64static void __net_exit ip6table_security_net_exit(struct net *net)
  65{
  66        if (!net->ipv6.ip6table_security)
  67                return;
  68        ip6t_unregister_table(net, net->ipv6.ip6table_security, sectbl_ops);
  69        net->ipv6.ip6table_security = NULL;
  70}
  71
  72static struct pernet_operations ip6table_security_net_ops = {
  73        .exit = ip6table_security_net_exit,
  74};
  75
  76static int __init ip6table_security_init(void)
  77{
  78        int ret;
  79
  80        sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
  81        if (IS_ERR(sectbl_ops))
  82                return PTR_ERR(sectbl_ops);
  83
  84        ret = register_pernet_subsys(&ip6table_security_net_ops);
  85        if (ret < 0) {
  86                kfree(sectbl_ops);
  87                return ret;
  88        }
  89
  90        ret = ip6table_security_table_init(&init_net);
  91        if (ret) {
  92                unregister_pernet_subsys(&ip6table_security_net_ops);
  93                kfree(sectbl_ops);
  94        }
  95        return ret;
  96}
  97
  98static void __exit ip6table_security_fini(void)
  99{
 100        unregister_pernet_subsys(&ip6table_security_net_ops);
 101        kfree(sectbl_ops);
 102}
 103
 104module_init(ip6table_security_init);
 105module_exit(ip6table_security_fini);
 106