1/*
2 * "security" table
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_ipv4/ip_tables.h>
20#include <linux/slab.h>
21#include <net/ip.h>
22
23MODULE_LICENSE("GPL");
24MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
25MODULE_DESCRIPTION("iptables security table, for MAC rules");
26
27#define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \
28 (1 << NF_INET_FORWARD) | \
29 (1 << NF_INET_LOCAL_OUT)
30
31static int __net_init iptable_security_table_init(struct net *net);
32
33static const struct xt_table security_table = {
34 .name = "security",
35 .valid_hooks = SECURITY_VALID_HOOKS,
36 .me = THIS_MODULE,
37 .af = NFPROTO_IPV4,
38 .priority = NF_IP_PRI_SECURITY,
39 .table_init = iptable_security_table_init,
40};
41
42static unsigned int
43iptable_security_hook(void *priv, struct sk_buff *skb,
44 const struct nf_hook_state *state)
45{
46 return ipt_do_table(skb, state, state->net->ipv4.iptable_security);
47}
48
49static struct nf_hook_ops *sectbl_ops __read_mostly;
50
51static int __net_init iptable_security_table_init(struct net *net)
52{
53 struct ipt_replace *repl;
54 int ret;
55
56 if (net->ipv4.iptable_security)
57 return 0;
58
59 repl = ipt_alloc_initial_table(&security_table);
60 if (repl == NULL)
61 return -ENOMEM;
62 ret = ipt_register_table(net, &security_table, repl, sectbl_ops,
63 &net->ipv4.iptable_security);
64 kfree(repl);
65 return ret;
66}
67
68static void __net_exit iptable_security_net_exit(struct net *net)
69{
70 if (!net->ipv4.iptable_security)
71 return;
72
73 ipt_unregister_table(net, net->ipv4.iptable_security, sectbl_ops);
74 net->ipv4.iptable_security = NULL;
75}
76
77static struct pernet_operations iptable_security_net_ops = {
78 .exit = iptable_security_net_exit,
79};
80
81static int __init iptable_security_init(void)
82{
83 int ret;
84
85 sectbl_ops = xt_hook_ops_alloc(&security_table, iptable_security_hook);
86 if (IS_ERR(sectbl_ops))
87 return PTR_ERR(sectbl_ops);
88
89 ret = register_pernet_subsys(&iptable_security_net_ops);
90 if (ret < 0) {
91 kfree(sectbl_ops);
92 return ret;
93 }
94
95 ret = iptable_security_table_init(&init_net);
96 if (ret) {
97 unregister_pernet_subsys(&iptable_security_net_ops);
98 kfree(sectbl_ops);
99 }
100
101 return ret;
102}
103
104static void __exit iptable_security_fini(void)
105{
106 unregister_pernet_subsys(&iptable_security_net_ops);
107 kfree(sectbl_ops);
108}
109
110module_init(iptable_security_init);
111module_exit(iptable_security_fini);
112