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560ee653 JM |
1 | /* |
2 | * "security" table | |
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_ipv4/ip_tables.h> | |
20 | #include <net/ip.h> | |
21 | ||
22 | MODULE_LICENSE("GPL"); | |
23 | MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>"); | |
24 | MODULE_DESCRIPTION("iptables security table, for MAC rules"); | |
25 | ||
26 | #define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \ | |
27 | (1 << NF_INET_FORWARD) | \ | |
28 | (1 << NF_INET_LOCAL_OUT) | |
29 | ||
35aad0ff | 30 | static const struct |
560ee653 JM |
31 | { |
32 | struct ipt_replace repl; | |
33 | struct ipt_standard entries[3]; | |
34 | struct ipt_error term; | |
f858b486 | 35 | } initial_table __net_initdata = { |
560ee653 JM |
36 | .repl = { |
37 | .name = "security", | |
38 | .valid_hooks = SECURITY_VALID_HOOKS, | |
39 | .num_entries = 4, | |
40 | .size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error), | |
41 | .hook_entry = { | |
42 | [NF_INET_LOCAL_IN] = 0, | |
43 | [NF_INET_FORWARD] = sizeof(struct ipt_standard), | |
44 | [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2, | |
45 | }, | |
46 | .underflow = { | |
47 | [NF_INET_LOCAL_IN] = 0, | |
48 | [NF_INET_FORWARD] = sizeof(struct ipt_standard), | |
49 | [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2, | |
50 | }, | |
51 | }, | |
52 | .entries = { | |
53 | IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */ | |
54 | IPT_STANDARD_INIT(NF_ACCEPT), /* FORWARD */ | |
55 | IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */ | |
56 | }, | |
57 | .term = IPT_ERROR_INIT, /* ERROR */ | |
58 | }; | |
59 | ||
35aad0ff | 60 | static const struct xt_table security_table = { |
560ee653 JM |
61 | .name = "security", |
62 | .valid_hooks = SECURITY_VALID_HOOKS, | |
560ee653 | 63 | .me = THIS_MODULE, |
f88e6a8a | 64 | .af = NFPROTO_IPV4, |
560ee653 JM |
65 | }; |
66 | ||
67 | static unsigned int | |
68 | ipt_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 ipt_do_table(skb, hook, in, out, | |
48dc7865 | 75 | dev_net(in)->ipv4.iptable_security); |
560ee653 JM |
76 | } |
77 | ||
78 | static unsigned int | |
79 | ipt_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 ipt_do_table(skb, hook, in, out, | |
48dc7865 | 86 | dev_net(in)->ipv4.iptable_security); |
560ee653 JM |
87 | } |
88 | ||
89 | static unsigned int | |
90 | ipt_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 | /* Somebody is playing with raw sockets. */ | |
97 | if (skb->len < sizeof(struct iphdr) | |
88843104 | 98 | || ip_hdrlen(skb) < sizeof(struct iphdr)) |
560ee653 | 99 | return NF_ACCEPT; |
560ee653 | 100 | return ipt_do_table(skb, hook, in, out, |
48dc7865 | 101 | dev_net(out)->ipv4.iptable_security); |
560ee653 JM |
102 | } |
103 | ||
104 | static struct nf_hook_ops ipt_ops[] __read_mostly = { | |
105 | { | |
106 | .hook = ipt_local_in_hook, | |
107 | .owner = THIS_MODULE, | |
24c232d8 | 108 | .pf = NFPROTO_IPV4, |
560ee653 JM |
109 | .hooknum = NF_INET_LOCAL_IN, |
110 | .priority = NF_IP_PRI_SECURITY, | |
111 | }, | |
112 | { | |
113 | .hook = ipt_forward_hook, | |
114 | .owner = THIS_MODULE, | |
24c232d8 | 115 | .pf = NFPROTO_IPV4, |
560ee653 JM |
116 | .hooknum = NF_INET_FORWARD, |
117 | .priority = NF_IP_PRI_SECURITY, | |
118 | }, | |
119 | { | |
120 | .hook = ipt_local_out_hook, | |
121 | .owner = THIS_MODULE, | |
24c232d8 | 122 | .pf = NFPROTO_IPV4, |
560ee653 JM |
123 | .hooknum = NF_INET_LOCAL_OUT, |
124 | .priority = NF_IP_PRI_SECURITY, | |
125 | }, | |
126 | }; | |
127 | ||
128 | static int __net_init iptable_security_net_init(struct net *net) | |
129 | { | |
130 | net->ipv4.iptable_security = | |
131 | ipt_register_table(net, &security_table, &initial_table.repl); | |
132 | ||
133 | if (IS_ERR(net->ipv4.iptable_security)) | |
134 | return PTR_ERR(net->ipv4.iptable_security); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static void __net_exit iptable_security_net_exit(struct net *net) | |
140 | { | |
141 | ipt_unregister_table(net->ipv4.iptable_security); | |
142 | } | |
143 | ||
144 | static struct pernet_operations iptable_security_net_ops = { | |
145 | .init = iptable_security_net_init, | |
146 | .exit = iptable_security_net_exit, | |
147 | }; | |
148 | ||
149 | static int __init iptable_security_init(void) | |
150 | { | |
151 | int ret; | |
152 | ||
153 | ret = register_pernet_subsys(&iptable_security_net_ops); | |
154 | if (ret < 0) | |
155 | return ret; | |
156 | ||
157 | ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); | |
158 | if (ret < 0) | |
159 | goto cleanup_table; | |
160 | ||
161 | return ret; | |
162 | ||
163 | cleanup_table: | |
164 | unregister_pernet_subsys(&iptable_security_net_ops); | |
165 | return ret; | |
166 | } | |
167 | ||
168 | static void __exit iptable_security_fini(void) | |
169 | { | |
170 | nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); | |
171 | unregister_pernet_subsys(&iptable_security_net_ops); | |
172 | } | |
173 | ||
174 | module_init(iptable_security_init); | |
175 | module_exit(iptable_security_fini); |