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 unsigned int
iptable_security_hook(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)37 iptable_security_hook(void *priv, struct sk_buff *skb,
38 const struct nf_hook_state *state)
39 {
40 return ipt_do_table(skb, state, priv);
41 }
42
43 static struct nf_hook_ops *sectbl_ops __read_mostly;
44
iptable_security_table_init(struct net * net)45 static int iptable_security_table_init(struct net *net)
46 {
47 struct ipt_replace *repl;
48 int ret;
49
50 repl = ipt_alloc_initial_table(&security_table);
51 if (repl == NULL)
52 return -ENOMEM;
53 ret = ipt_register_table(net, &security_table, repl, sectbl_ops);
54 kfree(repl);
55 return ret;
56 }
57
iptable_security_net_pre_exit(struct net * net)58 static void __net_exit iptable_security_net_pre_exit(struct net *net)
59 {
60 ipt_unregister_table_pre_exit(net, "security");
61 }
62
iptable_security_net_exit(struct net * net)63 static void __net_exit iptable_security_net_exit(struct net *net)
64 {
65 ipt_unregister_table_exit(net, "security");
66 }
67
68 static struct pernet_operations iptable_security_net_ops = {
69 .pre_exit = iptable_security_net_pre_exit,
70 .exit = iptable_security_net_exit,
71 };
72
iptable_security_init(void)73 static int __init iptable_security_init(void)
74 {
75 int ret = xt_register_template(&security_table,
76 iptable_security_table_init);
77
78 if (ret < 0)
79 return ret;
80
81 sectbl_ops = xt_hook_ops_alloc(&security_table, iptable_security_hook);
82 if (IS_ERR(sectbl_ops)) {
83 xt_unregister_template(&security_table);
84 return PTR_ERR(sectbl_ops);
85 }
86
87 ret = register_pernet_subsys(&iptable_security_net_ops);
88 if (ret < 0) {
89 xt_unregister_template(&security_table);
90 kfree(sectbl_ops);
91 return ret;
92 }
93
94 return ret;
95 }
96
iptable_security_fini(void)97 static void __exit iptable_security_fini(void)
98 {
99 unregister_pernet_subsys(&iptable_security_net_ops);
100 kfree(sectbl_ops);
101 xt_unregister_template(&security_table);
102 }
103
104 module_init(iptable_security_init);
105 module_exit(iptable_security_fini);
106