1 /*
2  *  ebt_mark_m
3  *
4  *	Authors:
5  *	Bart De Schuymer <bdschuym@pandora.be>
6  *
7  *  July, 2002
8  *
9  */
10 #include <linux/module.h>
11 #include <linux/netfilter/x_tables.h>
12 #include <linux/netfilter_bridge/ebtables.h>
13 #include <linux/netfilter_bridge/ebt_mark_m.h>
14 
15 static bool
ebt_mark_mt(const struct sk_buff * skb,struct xt_action_param * par)16 ebt_mark_mt(const struct sk_buff *skb, struct xt_action_param *par)
17 {
18 	const struct ebt_mark_m_info *info = par->matchinfo;
19 
20 	if (info->bitmask & EBT_MARK_OR)
21 		return !!(skb->mark & info->mask) ^ info->invert;
22 	return ((skb->mark & info->mask) == info->mark) ^ info->invert;
23 }
24 
ebt_mark_mt_check(const struct xt_mtchk_param * par)25 static int ebt_mark_mt_check(const struct xt_mtchk_param *par)
26 {
27 	const struct ebt_mark_m_info *info = par->matchinfo;
28 
29 	if (info->bitmask & ~EBT_MARK_MASK)
30 		return -EINVAL;
31 	if ((info->bitmask & EBT_MARK_OR) && (info->bitmask & EBT_MARK_AND))
32 		return -EINVAL;
33 	if (!info->bitmask)
34 		return -EINVAL;
35 	return 0;
36 }
37 
38 
39 #ifdef CONFIG_COMPAT
40 struct compat_ebt_mark_m_info {
41 	compat_ulong_t mark, mask;
42 	uint8_t invert, bitmask;
43 };
44 
mark_mt_compat_from_user(void * dst,const void * src)45 static void mark_mt_compat_from_user(void *dst, const void *src)
46 {
47 	const struct compat_ebt_mark_m_info *user = src;
48 	struct ebt_mark_m_info *kern = dst;
49 
50 	kern->mark = user->mark;
51 	kern->mask = user->mask;
52 	kern->invert = user->invert;
53 	kern->bitmask = user->bitmask;
54 }
55 
mark_mt_compat_to_user(void __user * dst,const void * src)56 static int mark_mt_compat_to_user(void __user *dst, const void *src)
57 {
58 	struct compat_ebt_mark_m_info __user *user = dst;
59 	const struct ebt_mark_m_info *kern = src;
60 
61 	if (put_user(kern->mark, &user->mark) ||
62 	    put_user(kern->mask, &user->mask) ||
63 	    put_user(kern->invert, &user->invert) ||
64 	    put_user(kern->bitmask, &user->bitmask))
65 		return -EFAULT;
66 	return 0;
67 }
68 #endif
69 
70 static struct xt_match ebt_mark_mt_reg __read_mostly = {
71 	.name		= "mark_m",
72 	.revision	= 0,
73 	.family		= NFPROTO_BRIDGE,
74 	.match		= ebt_mark_mt,
75 	.checkentry	= ebt_mark_mt_check,
76 	.matchsize	= sizeof(struct ebt_mark_m_info),
77 #ifdef CONFIG_COMPAT
78 	.compatsize	= sizeof(struct compat_ebt_mark_m_info),
79 	.compat_from_user = mark_mt_compat_from_user,
80 	.compat_to_user	= mark_mt_compat_to_user,
81 #endif
82 	.me		= THIS_MODULE,
83 };
84 
ebt_mark_m_init(void)85 static int __init ebt_mark_m_init(void)
86 {
87 	return xt_register_match(&ebt_mark_mt_reg);
88 }
89 
ebt_mark_m_fini(void)90 static void __exit ebt_mark_m_fini(void)
91 {
92 	xt_unregister_match(&ebt_mark_mt_reg);
93 }
94 
95 module_init(ebt_mark_m_init);
96 module_exit(ebt_mark_m_fini);
97 MODULE_DESCRIPTION("Ebtables: Packet mark match");
98 MODULE_LICENSE("GPL");
99