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
20MODULE_LICENSE("GPL");
21MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
22MODULE_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
28static 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
36static struct nf_hook_ops *sectbl_ops __read_mostly;
37
38static 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, table: &security_table, repl, ops: sectbl_ops);
47 kfree(objp: repl);
48 return ret;
49}
50
51static void __net_exit iptable_security_net_pre_exit(struct net *net)
52{
53 ipt_unregister_table_pre_exit(net, name: "security");
54}
55
56static void __net_exit iptable_security_net_exit(struct net *net)
57{
58 ipt_unregister_table_exit(net, name: "security");
59}
60
61static struct pernet_operations iptable_security_net_ops = {
62 .pre_exit = iptable_security_net_pre_exit,
63 .exit = iptable_security_net_exit,
64};
65
66static int __init iptable_security_init(void)
67{
68 int ret = xt_register_template(t: &security_table,
69 table_init: 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(ptr: sectbl_ops)) {
76 xt_unregister_template(t: &security_table);
77 return PTR_ERR(ptr: sectbl_ops);
78 }
79
80 ret = register_pernet_subsys(&iptable_security_net_ops);
81 if (ret < 0) {
82 xt_unregister_template(t: &security_table);
83 kfree(objp: sectbl_ops);
84 return ret;
85 }
86
87 return ret;
88}
89
90static void __exit iptable_security_fini(void)
91{
92 unregister_pernet_subsys(&iptable_security_net_ops);
93 kfree(objp: sectbl_ops);
94 xt_unregister_template(t: &security_table);
95}
96
97module_init(iptable_security_init);
98module_exit(iptable_security_fini);
99

source code of linux/net/ipv4/netfilter/iptable_security.c