1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * "security" table
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_ipv4/ip_tables.h>
17 #include <linux/slab.h>
18 #include <net/ip.h>
19 
20 MODULE_LICENSE("GPL");
21 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
22 MODULE_DESCRIPTION("iptables security table, for MAC rules");
23 
24 #define SECURITY_VALID_HOOKS	(1 << NF_INET_LOCAL_IN) | \
25 				(1 << NF_INET_FORWARD) | \
26 				(1 << NF_INET_LOCAL_OUT)
27 
28 static const struct xt_table security_table = {
29 	.name		= "security",
30 	.valid_hooks	= SECURITY_VALID_HOOKS,
31 	.me		= THIS_MODULE,
32 	.af		= NFPROTO_IPV4,
33 	.priority	= NF_IP_PRI_SECURITY,
34 };
35 
36 static struct nf_hook_ops *sectbl_ops __read_mostly;
37 
iptable_security_table_init(struct net * net)38 static int iptable_security_table_init(struct net *net)
39 {
40 	struct ipt_replace *repl;
41 	int ret;
42 
43 	repl = ipt_alloc_initial_table(&security_table);
44 	if (repl == NULL)
45 		return -ENOMEM;
46 	ret = ipt_register_table(net, &security_table, repl, sectbl_ops);
47 	kfree(repl);
48 	return ret;
49 }
50 
iptable_security_net_pre_exit(struct net * net)51 static void __net_exit iptable_security_net_pre_exit(struct net *net)
52 {
53 	ipt_unregister_table_pre_exit(net, "security");
54 }
55 
iptable_security_net_exit(struct net * net)56 static void __net_exit iptable_security_net_exit(struct net *net)
57 {
58 	ipt_unregister_table_exit(net, "security");
59 }
60 
61 static struct pernet_operations iptable_security_net_ops = {
62 	.pre_exit = iptable_security_net_pre_exit,
63 	.exit = iptable_security_net_exit,
64 };
65 
iptable_security_init(void)66 static int __init iptable_security_init(void)
67 {
68 	int ret = xt_register_template(&security_table,
69 				       iptable_security_table_init);
70 
71 	if (ret < 0)
72 		return ret;
73 
74 	sectbl_ops = xt_hook_ops_alloc(&security_table, ipt_do_table);
75 	if (IS_ERR(sectbl_ops)) {
76 		xt_unregister_template(&security_table);
77 		return PTR_ERR(sectbl_ops);
78 	}
79 
80 	ret = register_pernet_subsys(&iptable_security_net_ops);
81 	if (ret < 0) {
82 		xt_unregister_template(&security_table);
83 		kfree(sectbl_ops);
84 		return ret;
85 	}
86 
87 	return ret;
88 }
89 
iptable_security_fini(void)90 static void __exit iptable_security_fini(void)
91 {
92 	unregister_pernet_subsys(&iptable_security_net_ops);
93 	kfree(sectbl_ops);
94 	xt_unregister_template(&security_table);
95 }
96 
97 module_init(iptable_security_init);
98 module_exit(iptable_security_fini);
99