1 /*
2  * "security" table for IPv6
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_ipv6/ip6_tables.h>
20 #include <linux/slab.h>
21 
22 MODULE_LICENSE("GPL");
23 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
24 MODULE_DESCRIPTION("ip6tables security table, for MAC rules");
25 
26 #define SECURITY_VALID_HOOKS	(1 << NF_INET_LOCAL_IN) | \
27 				(1 << NF_INET_FORWARD) | \
28 				(1 << NF_INET_LOCAL_OUT)
29 
30 static int __net_init ip6table_security_table_init(struct net *net);
31 
32 static const struct xt_table security_table = {
33 	.name		= "security",
34 	.valid_hooks	= SECURITY_VALID_HOOKS,
35 	.me		= THIS_MODULE,
36 	.af		= NFPROTO_IPV6,
37 	.priority	= NF_IP6_PRI_SECURITY,
38 	.table_init     = ip6table_security_table_init,
39 };
40 
41 static unsigned int
42 ip6table_security_hook(void *priv, struct sk_buff *skb,
43 		       const struct nf_hook_state *state)
44 {
45 	return ip6t_do_table(skb, state, state->net->ipv6.ip6table_security);
46 }
47 
48 static struct nf_hook_ops *sectbl_ops __read_mostly;
49 
50 static int __net_init ip6table_security_table_init(struct net *net)
51 {
52 	struct ip6t_replace *repl;
53 	int ret;
54 
55 	if (net->ipv6.ip6table_security)
56 		return 0;
57 
58 	repl = ip6t_alloc_initial_table(&security_table);
59 	if (repl == NULL)
60 		return -ENOMEM;
61 	ret = ip6t_register_table(net, &security_table, repl, sectbl_ops,
62 				  &net->ipv6.ip6table_security);
63 	kfree(repl);
64 	return ret;
65 }
66 
67 static void __net_exit ip6table_security_net_exit(struct net *net)
68 {
69 	if (!net->ipv6.ip6table_security)
70 		return;
71 	ip6t_unregister_table(net, net->ipv6.ip6table_security, sectbl_ops);
72 	net->ipv6.ip6table_security = NULL;
73 }
74 
75 static struct pernet_operations ip6table_security_net_ops = {
76 	.exit = ip6table_security_net_exit,
77 };
78 
79 static int __init ip6table_security_init(void)
80 {
81 	int ret;
82 
83 	sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
84 	if (IS_ERR(sectbl_ops))
85 		return PTR_ERR(sectbl_ops);
86 
87 	ret = register_pernet_subsys(&ip6table_security_net_ops);
88 	if (ret < 0) {
89 		kfree(sectbl_ops);
90 		return ret;
91 	}
92 
93 	ret = ip6table_security_table_init(&init_net);
94 	if (ret) {
95 		unregister_pernet_subsys(&ip6table_security_net_ops);
96 		kfree(sectbl_ops);
97 	}
98 	return ret;
99 }
100 
101 static void __exit ip6table_security_fini(void)
102 {
103 	unregister_pernet_subsys(&ip6table_security_net_ops);
104 	kfree(sectbl_ops);
105 }
106 
107 module_init(ip6table_security_init);
108 module_exit(ip6table_security_fini);
109