1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * "security" table for IPv6
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_ipv6/ip6_tables.h>
17 #include <linux/slab.h>
18
19 MODULE_LICENSE("GPL");
20 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
21 MODULE_DESCRIPTION("ip6tables security table, for MAC rules");
22
23 #define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \
24 (1 << NF_INET_FORWARD) | \
25 (1 << NF_INET_LOCAL_OUT)
26
27 static int __net_init ip6table_security_table_init(struct net *net);
28
29 static const struct xt_table security_table = {
30 .name = "security",
31 .valid_hooks = SECURITY_VALID_HOOKS,
32 .me = THIS_MODULE,
33 .af = NFPROTO_IPV6,
34 .priority = NF_IP6_PRI_SECURITY,
35 .table_init = ip6table_security_table_init,
36 };
37
38 static unsigned int
ip6table_security_hook(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)39 ip6table_security_hook(void *priv, struct sk_buff *skb,
40 const struct nf_hook_state *state)
41 {
42 return ip6t_do_table(skb, state, state->net->ipv6.ip6table_security);
43 }
44
45 static struct nf_hook_ops *sectbl_ops __read_mostly;
46
ip6table_security_table_init(struct net * net)47 static int __net_init ip6table_security_table_init(struct net *net)
48 {
49 struct ip6t_replace *repl;
50 int ret;
51
52 if (net->ipv6.ip6table_security)
53 return 0;
54
55 repl = ip6t_alloc_initial_table(&security_table);
56 if (repl == NULL)
57 return -ENOMEM;
58 ret = ip6t_register_table(net, &security_table, repl, sectbl_ops,
59 &net->ipv6.ip6table_security);
60 kfree(repl);
61 return ret;
62 }
63
ip6table_security_net_pre_exit(struct net * net)64 static void __net_exit ip6table_security_net_pre_exit(struct net *net)
65 {
66 if (net->ipv6.ip6table_security)
67 ip6t_unregister_table_pre_exit(net, net->ipv6.ip6table_security,
68 sectbl_ops);
69 }
70
ip6table_security_net_exit(struct net * net)71 static void __net_exit ip6table_security_net_exit(struct net *net)
72 {
73 if (!net->ipv6.ip6table_security)
74 return;
75 ip6t_unregister_table_exit(net, net->ipv6.ip6table_security);
76 net->ipv6.ip6table_security = NULL;
77 }
78
79 static struct pernet_operations ip6table_security_net_ops = {
80 .pre_exit = ip6table_security_net_pre_exit,
81 .exit = ip6table_security_net_exit,
82 };
83
ip6table_security_init(void)84 static int __init ip6table_security_init(void)
85 {
86 int ret;
87
88 sectbl_ops = xt_hook_ops_alloc(&security_table, ip6table_security_hook);
89 if (IS_ERR(sectbl_ops))
90 return PTR_ERR(sectbl_ops);
91
92 ret = register_pernet_subsys(&ip6table_security_net_ops);
93 if (ret < 0) {
94 kfree(sectbl_ops);
95 return ret;
96 }
97
98 ret = ip6table_security_table_init(&init_net);
99 if (ret) {
100 unregister_pernet_subsys(&ip6table_security_net_ops);
101 kfree(sectbl_ops);
102 }
103 return ret;
104 }
105
ip6table_security_fini(void)106 static void __exit ip6table_security_fini(void)
107 {
108 unregister_pernet_subsys(&ip6table_security_net_ops);
109 kfree(sectbl_ops);
110 }
111
112 module_init(ip6table_security_init);
113 module_exit(ip6table_security_fini);
114