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100468e9 JM |
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, | |
fe1cb108 | 69 | const void *targinfo) |
100468e9 JM |
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, | |
efa74165 | 92 | unsigned int hook_mask) |
100468e9 JM |
93 | { |
94 | struct xt_connsecmark_target_info *info = targinfo; | |
95 | ||
96 | switch (info->mode) { | |
97 | case CONNSECMARK_SAVE: | |
98 | case CONNSECMARK_RESTORE: | |
99 | break; | |
100 | ||
101 | default: | |
102 | printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode); | |
103 | return 0; | |
104 | } | |
105 | ||
106 | return 1; | |
107 | } | |
108 | ||
4470bbc7 PM |
109 | static struct xt_target xt_connsecmark_target[] = { |
110 | { | |
111 | .name = "CONNSECMARK", | |
112 | .family = AF_INET, | |
113 | .checkentry = checkentry, | |
114 | .target = target, | |
115 | .targetsize = sizeof(struct xt_connsecmark_target_info), | |
116 | .table = "mangle", | |
117 | .me = THIS_MODULE, | |
118 | }, | |
119 | { | |
120 | .name = "CONNSECMARK", | |
121 | .family = AF_INET6, | |
122 | .checkentry = checkentry, | |
123 | .target = target, | |
124 | .targetsize = sizeof(struct xt_connsecmark_target_info), | |
125 | .table = "mangle", | |
126 | .me = THIS_MODULE, | |
127 | }, | |
100468e9 JM |
128 | }; |
129 | ||
130 | static int __init xt_connsecmark_init(void) | |
131 | { | |
100468e9 | 132 | need_conntrack(); |
4470bbc7 PM |
133 | return xt_register_targets(xt_connsecmark_targets, |
134 | ARRAY_SIZE(xt_connsecmark_targets)); | |
100468e9 JM |
135 | } |
136 | ||
137 | static void __exit xt_connsecmark_fini(void) | |
138 | { | |
4470bbc7 PM |
139 | xt_unregister_targets(xt_connsecmark_targets, |
140 | ARRAY_SIZE(xt_connsecmark_targets)); | |
100468e9 JM |
141 | } |
142 | ||
143 | module_init(xt_connsecmark_init); | |
144 | module_exit(xt_connsecmark_fini); |