1/* Kernel module to match NFMARK values. */
2
3/* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/module.h>
11#include <linux/skbuff.h>
12
13#include <linux/netfilter/xt_mark.h>
14#include <linux/netfilter/x_tables.h>
15
16MODULE_LICENSE("GPL");
17MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
18MODULE_DESCRIPTION("iptables mark matching module");
19MODULE_ALIAS("ipt_mark");
20MODULE_ALIAS("ip6t_mark");
21
22static int
23match(const struct sk_buff *skb,
24      const struct net_device *in,
25      const struct net_device *out,
26      const struct xt_match *match,
27      const void *matchinfo,
28      int offset,
29      unsigned int protoff,
30      int *hotdrop)
31{
32	const struct xt_mark_info *info = matchinfo;
33
34	return ((skb->mark & info->mask) == info->mark) ^ info->invert;
35}
36
37static int
38checkentry(const char *tablename,
39	   const void *entry,
40	   const struct xt_match *match,
41	   void *matchinfo,
42	   unsigned int hook_mask)
43{
44	const struct xt_mark_info *minfo = matchinfo;
45
46	if (minfo->mark > 0xffffffff || minfo->mask > 0xffffffff) {
47		printk(KERN_WARNING "mark: only supports 32bit mark\n");
48		return 0;
49	}
50	return 1;
51}
52
53#ifdef CONFIG_COMPAT
54struct compat_xt_mark_info {
55	compat_ulong_t	mark, mask;
56	u_int8_t	invert;
57	u_int8_t	__pad1;
58	u_int16_t	__pad2;
59};
60
61static void compat_from_user(void *dst, void *src)
62{
63	struct compat_xt_mark_info *cm = src;
64	struct xt_mark_info m = {
65		.mark	= cm->mark,
66		.mask	= cm->mask,
67		.invert	= cm->invert,
68	};
69	memcpy(dst, &m, sizeof(m));
70}
71
72static int compat_to_user(void __user *dst, void *src)
73{
74	struct xt_mark_info *m = src;
75	struct compat_xt_mark_info cm = {
76		.mark	= m->mark,
77		.mask	= m->mask,
78		.invert	= m->invert,
79	};
80	return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
81}
82#endif /* CONFIG_COMPAT */
83
84static struct xt_match xt_mark_match[] = {
85	{
86		.name		= "mark",
87		.family		= AF_INET,
88		.checkentry	= checkentry,
89		.match		= match,
90		.matchsize	= sizeof(struct xt_mark_info),
91#ifdef CONFIG_COMPAT
92		.compatsize	= sizeof(struct compat_xt_mark_info),
93		.compat_from_user = compat_from_user,
94		.compat_to_user	= compat_to_user,
95#endif
96		.me		= THIS_MODULE,
97	},
98	{
99		.name		= "mark",
100		.family		= AF_INET6,
101		.checkentry	= checkentry,
102		.match		= match,
103		.matchsize	= sizeof(struct xt_mark_info),
104		.me		= THIS_MODULE,
105	},
106};
107
108static int __init xt_mark_init(void)
109{
110	return xt_register_matches(xt_mark_match, ARRAY_SIZE(xt_mark_match));
111}
112
113static void __exit xt_mark_fini(void)
114{
115	xt_unregister_matches(xt_mark_match, ARRAY_SIZE(xt_mark_match));
116}
117
118module_init(xt_mark_init);
119module_exit(xt_mark_fini);
120