Merge branch 'drm-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...
[linux-2.6] / net / netfilter / xt_CONNSECMARK.c
1 /*
2  * This module is used to copy security markings from packets
3  * to connections, and restore security markings from connections
4  * back to packets.  This would normally be performed in conjunction
5  * with the SECMARK target and state match.
6  *
7  * Based somewhat on CONNMARK:
8  *   Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
9  *    by Henrik Nordstrom <hno@marasystems.com>
10  *
11  * (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License version 2 as
15  * published by the Free Software Foundation.
16  *
17  */
18 #include <linux/module.h>
19 #include <linux/skbuff.h>
20 #include <linux/netfilter/x_tables.h>
21 #include <linux/netfilter/xt_CONNSECMARK.h>
22 #include <net/netfilter/nf_conntrack_compat.h>
23
24 #define PFX "CONNSECMARK: "
25
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
28 MODULE_DESCRIPTION("ip[6]tables CONNSECMARK module");
29 MODULE_ALIAS("ipt_CONNSECMARK");
30 MODULE_ALIAS("ip6t_CONNSECMARK");
31
32 /*
33  * If the packet has a security mark and the connection does not, copy
34  * the security mark from the packet to the connection.
35  */
36 static void secmark_save(struct sk_buff *skb)
37 {
38         if (skb->secmark) {
39                 u32 *connsecmark;
40                 enum ip_conntrack_info ctinfo;
41
42                 connsecmark = nf_ct_get_secmark(skb, &ctinfo);
43                 if (connsecmark && !*connsecmark)
44                         if (*connsecmark != skb->secmark)
45                                 *connsecmark = skb->secmark;
46         }
47 }
48
49 /*
50  * If packet has no security mark, and the connection does, restore the
51  * security mark from the connection to the packet.
52  */
53 static void secmark_restore(struct sk_buff *skb)
54 {
55         if (!skb->secmark) {
56                 u32 *connsecmark;
57                 enum ip_conntrack_info ctinfo;
58
59                 connsecmark = nf_ct_get_secmark(skb, &ctinfo);
60                 if (connsecmark && *connsecmark)
61                         if (skb->secmark != *connsecmark)
62                                 skb->secmark = *connsecmark;
63         }
64 }
65
66 static unsigned int target(struct sk_buff **pskb, const struct net_device *in,
67                            const struct net_device *out, unsigned int hooknum,
68                            const struct xt_target *target,
69                            const void *targinfo)
70 {
71         struct sk_buff *skb = *pskb;
72         const struct xt_connsecmark_target_info *info = targinfo;
73
74         switch (info->mode) {
75         case CONNSECMARK_SAVE:
76                 secmark_save(skb);
77                 break;
78
79         case CONNSECMARK_RESTORE:
80                 secmark_restore(skb);
81                 break;
82
83         default:
84                 BUG();
85         }
86
87         return XT_CONTINUE;
88 }
89
90 static int checkentry(const char *tablename, const void *entry,
91                       const struct xt_target *target, void *targinfo,
92                       unsigned int hook_mask)
93 {
94         struct xt_connsecmark_target_info *info = targinfo;
95
96         if (nf_ct_l3proto_try_module_get(target->family) < 0) {
97                 printk(KERN_WARNING "can't load conntrack support for "
98                                     "proto=%d\n", target->family);
99                 return 0;
100         }
101         switch (info->mode) {
102         case CONNSECMARK_SAVE:
103         case CONNSECMARK_RESTORE:
104                 break;
105
106         default:
107                 printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
108                 return 0;
109         }
110
111         return 1;
112 }
113
114 static void
115 destroy(const struct xt_target *target, void *targinfo)
116 {
117         nf_ct_l3proto_module_put(target->family);
118 }
119
120 static struct xt_target xt_connsecmark_target[] = {
121         {
122                 .name           = "CONNSECMARK",
123                 .family         = AF_INET,
124                 .checkentry     = checkentry,
125                 .destroy        = destroy,
126                 .target         = target,
127                 .targetsize     = sizeof(struct xt_connsecmark_target_info),
128                 .table          = "mangle",
129                 .me             = THIS_MODULE,
130         },
131         {
132                 .name           = "CONNSECMARK",
133                 .family         = AF_INET6,
134                 .checkentry     = checkentry,
135                 .destroy        = destroy,
136                 .target         = target,
137                 .targetsize     = sizeof(struct xt_connsecmark_target_info),
138                 .table          = "mangle",
139                 .me             = THIS_MODULE,
140         },
141 };
142
143 static int __init xt_connsecmark_init(void)
144 {
145         return xt_register_targets(xt_connsecmark_target,
146                                    ARRAY_SIZE(xt_connsecmark_target));
147 }
148
149 static void __exit xt_connsecmark_fini(void)
150 {
151         xt_unregister_targets(xt_connsecmark_target,
152                               ARRAY_SIZE(xt_connsecmark_target));
153 }
154
155 module_init(xt_connsecmark_init);
156 module_exit(xt_connsecmark_fini);