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_pre_exit(struct net *net)
  65{
  66        if (net->ipv6.ip6table_security)
  67                ip6t_unregister_table_pre_exit(net, net->ipv6.ip6table_security,
  68                                               sectbl_ops);
  69}
  70
  71static void __net_exit ip6table_security_net_exit(struct net *net)
  72{
  73        if (!net->ipv6.ip6table_security)
  74                return;
  75        ip6t_unregister_table_exit(net, net->ipv6.ip6table_security);
  76        net->ipv6.ip6table_security = NULL;
  77}
  78
  79static struct pernet_operations ip6table_security_net_ops = {
  80        .pre_exit = ip6table_security_net_pre_exit,
  81        .exit = ip6table_security_net_exit,
  82};
  83
  84static int __init ip6table_security_init(void)
  85{
  86        int ret;
  87
  88        sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
  89        if (IS_ERR(sectbl_ops))
  90                return PTR_ERR(sectbl_ops);
  91
  92        ret = register_pernet_subsys(&ip6table_security_net_ops);
  93        if (ret < 0) {
  94                kfree(sectbl_ops);
  95                return ret;
  96        }
  97
  98        ret = ip6table_security_table_init(&init_net);
  99        if (ret) {
 100                unregister_pernet_subsys(&ip6table_security_net_ops);
 101                kfree(sectbl_ops);
 102        }
 103        return ret;
 104}
 105
 106static void __exit ip6table_security_fini(void)
 107{
 108        unregister_pernet_subsys(&ip6table_security_net_ops);
 109        kfree(sectbl_ops);
 110}
 111
 112module_init(ip6table_security_init);
 113module_exit(ip6table_security_fini);
 114