1 /*
2 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9 #include <linux/module.h>
10 #include <linux/skbuff.h>
11 #include <linux/netdevice.h>
12
13 #include <linux/netfilter/xt_devgroup.h>
14 #include <linux/netfilter/x_tables.h>
15
16 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
17 MODULE_LICENSE("GPL");
18 MODULE_DESCRIPTION("Xtables: Device group match");
19 MODULE_ALIAS("ipt_devgroup");
20 MODULE_ALIAS("ip6t_devgroup");
21
22 static bool devgroup_mt(const struct sk_buff *skb, struct xt_action_param *par)
23 {
24 const struct xt_devgroup_info *info = par->matchinfo;
25
26 if (info->flags & XT_DEVGROUP_MATCH_SRC &&
27 (((info->src_group ^ xt_in(par)->group) & info->src_mask ? 1 : 0) ^
28 ((info->flags & XT_DEVGROUP_INVERT_SRC) ? 1 : 0)))
29 return false;
30
31 if (info->flags & XT_DEVGROUP_MATCH_DST &&
32 (((info->dst_group ^ xt_out(par)->group) & info->dst_mask ? 1 : 0) ^
33 ((info->flags & XT_DEVGROUP_INVERT_DST) ? 1 : 0)))
34 return false;
35
36 return true;
37 }
38
39 static int devgroup_mt_checkentry(const struct xt_mtchk_param *par)
40 {
41 const struct xt_devgroup_info *info = par->matchinfo;
42
43 if (info->flags & ~(XT_DEVGROUP_MATCH_SRC | XT_DEVGROUP_INVERT_SRC |
44 XT_DEVGROUP_MATCH_DST | XT_DEVGROUP_INVERT_DST))
45 return -EINVAL;
46
47 if (info->flags & XT_DEVGROUP_MATCH_SRC &&
48 par->hook_mask & ~((1 << NF_INET_PRE_ROUTING) |
49 (1 << NF_INET_LOCAL_IN) |
50 (1 << NF_INET_FORWARD)))
51 return -EINVAL;
52
53 if (info->flags & XT_DEVGROUP_MATCH_DST &&
54 par->hook_mask & ~((1 << NF_INET_FORWARD) |
55 (1 << NF_INET_LOCAL_OUT) |
56 (1 << NF_INET_POST_ROUTING)))
57 return -EINVAL;
58
59 return 0;
60 }
61
62 static struct xt_match devgroup_mt_reg __read_mostly = {
63 .name = "devgroup",
64 .match = devgroup_mt,
65 .checkentry = devgroup_mt_checkentry,
66 .matchsize = sizeof(struct xt_devgroup_info),
67 .family = NFPROTO_UNSPEC,
68 .me = THIS_MODULE
69 };
70
71 static int __init devgroup_mt_init(void)
72 {
73 return xt_register_match(&devgroup_mt_reg);
74 }
75
76 static void __exit devgroup_mt_exit(void)
77 {
78 xt_unregister_match(&devgroup_mt_reg);
79 }
80
81 module_init(devgroup_mt_init);
82 module_exit(devgroup_mt_exit);
83
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