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
21 MODULE_LICENSE("GPL");
22 MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
23 MODULE_DESCRIPTION("ip6tables security table, for MAC rules");
24
25 #define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \
26 (1 << NF_INET_FORWARD) | \
27 (1 << NF_INET_LOCAL_OUT)
28
29 static struct
30 {
31 struct ip6t_replace repl;
32 struct ip6t_standard entries[3];
33 struct ip6t_error term;
34 } initial_table __net_initdata = {
35 .repl = {
36 .name = "security",
37 .valid_hooks = SECURITY_VALID_HOOKS,
38 .num_entries = 4,
39 .size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
40 .hook_entry = {
41 [NF_INET_LOCAL_IN] = 0,
42 [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
43 [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2,
44 },
45 .underflow = {
46 [NF_INET_LOCAL_IN] = 0,
47 [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
48 [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2,
49 },
50 },
51 .entries = {
52 IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
53 IP6T_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
54 IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
55 },
56 .term = IP6T_ERROR_INIT, /* ERROR */
57 };
58
59 static struct xt_table security_table = {
60 .name = "security",
61 .valid_hooks = SECURITY_VALID_HOOKS,
62 .lock = __RW_LOCK_UNLOCKED(security_table.lock),
63 .me = THIS_MODULE,
64 .af = AF_INET6,
65 };
66
67 static unsigned int
ip6t_local_in_hook(unsigned int hook,struct sk_buff * skb,const struct net_device * in,const struct net_device * out,int (* okfn)(struct sk_buff *))68 ip6t_local_in_hook(unsigned int hook,
69 struct sk_buff *skb,
70 const struct net_device *in,
71 const struct net_device *out,
72 int (*okfn)(struct sk_buff *))
73 {
74 return ip6t_do_table(skb, hook, in, out,
75 dev_net(in)->ipv6.ip6table_security);
76 }
77
78 static unsigned int
ip6t_forward_hook(unsigned int hook,struct sk_buff * skb,const struct net_device * in,const struct net_device * out,int (* okfn)(struct sk_buff *))79 ip6t_forward_hook(unsigned int hook,
80 struct sk_buff *skb,
81 const struct net_device *in,
82 const struct net_device *out,
83 int (*okfn)(struct sk_buff *))
84 {
85 return ip6t_do_table(skb, hook, in, out,
86 dev_net(in)->ipv6.ip6table_security);
87 }
88
89 static unsigned int
ip6t_local_out_hook(unsigned int hook,struct sk_buff * skb,const struct net_device * in,const struct net_device * out,int (* okfn)(struct sk_buff *))90 ip6t_local_out_hook(unsigned int hook,
91 struct sk_buff *skb,
92 const struct net_device *in,
93 const struct net_device *out,
94 int (*okfn)(struct sk_buff *))
95 {
96 /* TBD: handle short packets via raw socket */
97 return ip6t_do_table(skb, hook, in, out,
98 dev_net(out)->ipv6.ip6table_security);
99 }
100
101 static struct nf_hook_ops ip6t_ops[] __read_mostly = {
102 {
103 .hook = ip6t_local_in_hook,
104 .owner = THIS_MODULE,
105 .pf = PF_INET6,
106 .hooknum = NF_INET_LOCAL_IN,
107 .priority = NF_IP6_PRI_SECURITY,
108 },
109 {
110 .hook = ip6t_forward_hook,
111 .owner = THIS_MODULE,
112 .pf = PF_INET6,
113 .hooknum = NF_INET_FORWARD,
114 .priority = NF_IP6_PRI_SECURITY,
115 },
116 {
117 .hook = ip6t_local_out_hook,
118 .owner = THIS_MODULE,
119 .pf = PF_INET6,
120 .hooknum = NF_INET_LOCAL_OUT,
121 .priority = NF_IP6_PRI_SECURITY,
122 },
123 };
124
ip6table_security_net_init(struct net * net)125 static int __net_init ip6table_security_net_init(struct net *net)
126 {
127 net->ipv6.ip6table_security =
128 ip6t_register_table(net, &security_table, &initial_table.repl);
129
130 if (IS_ERR(net->ipv6.ip6table_security))
131 return PTR_ERR(net->ipv6.ip6table_security);
132
133 return 0;
134 }
135
ip6table_security_net_exit(struct net * net)136 static void __net_exit ip6table_security_net_exit(struct net *net)
137 {
138 ip6t_unregister_table(net->ipv6.ip6table_security);
139 }
140
141 static struct pernet_operations ip6table_security_net_ops = {
142 .init = ip6table_security_net_init,
143 .exit = ip6table_security_net_exit,
144 };
145
ip6table_security_init(void)146 static int __init ip6table_security_init(void)
147 {
148 int ret;
149
150 ret = register_pernet_subsys(&ip6table_security_net_ops);
151 if (ret < 0)
152 return ret;
153
154 ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
155 if (ret < 0)
156 goto cleanup_table;
157
158 return ret;
159
160 cleanup_table:
161 unregister_pernet_subsys(&ip6table_security_net_ops);
162 return ret;
163 }
164
ip6table_security_fini(void)165 static void __exit ip6table_security_fini(void)
166 {
167 nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
168 unregister_pernet_subsys(&ip6table_security_net_ops);
169 }
170
171 module_init(ip6table_security_init);
172 module_exit(ip6table_security_fini);
173