aboutsummaryrefslogtreecommitdiff
path: root/net/netfilter/xt_dscp.c
blob: 26c7f4ad102a0f34c1024abca184ede8aab7cd51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
 *
 * xt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp
 *
 * (C) 2002 by Harald Welte <laforge@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/dsfield.h>

#include <linux/netfilter/xt_dscp.h>
#include <linux/netfilter/x_tables.h>

MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("x_tables DSCP matching module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_dscp");
MODULE_ALIAS("ip6t_dscp");

static int match(const struct sk_buff *skb,
		 const struct net_device *in,
		 const struct net_device *out,
		 const struct xt_match *match,
		 const void *matchinfo,
		 int offset,
		 unsigned int protoff,
		 int *hotdrop)
{
	const struct xt_dscp_info *info = matchinfo;
	u_int8_t dscp = ipv4_get_dsfield(skb->nh.iph) >> XT_DSCP_SHIFT;

	return (dscp == info->dscp) ^ !!info->invert;
}

static int match6(const struct sk_buff *skb,
		  const struct net_device *in,
		  const struct net_device *out,
		  const struct xt_match *match,
		  const void *matchinfo,
		  int offset,
		  unsigned int protoff,
		  int *hotdrop)
{
	const struct xt_dscp_info *info = matchinfo;
	u_int8_t dscp = ipv6_get_dsfield(skb->nh.ipv6h) >> XT_DSCP_SHIFT;

	return (dscp == info->dscp) ^ !!info->invert;
}

static int checkentry(const char *tablename,
		      const void *info,
		      const struct xt_match *match,
		      void *matchinfo,
		      unsigned int hook_mask)
{
	const u_int8_t dscp = ((struct xt_dscp_info *)matchinfo)->dscp;

	if (dscp > XT_DSCP_MAX) {
		printk(KERN_ERR "xt_dscp: dscp %x out of range\n", dscp);
		return 0;
	}

	return 1;
}

static struct xt_match xt_dscp_match[] = {
	{
		.name		= "dscp",
		.family		= AF_INET,
		.checkentry	= checkentry,
		.match		= match,
		.matchsize	= sizeof(struct xt_dscp_info),
		.me		= THIS_MODULE,
	},
	{
		.name		= "dscp",
		.family		= AF_INET6,
		.checkentry	= checkentry,
		.match		= match6,
		.matchsize	= sizeof(struct xt_dscp_info),
		.me		= THIS_MODULE,
	},
};

static int __init xt_dscp_match_init(void)
{
	return xt_register_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match));
}

static void __exit xt_dscp_match_fini(void)
{
	xt_unregister_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match));
}

module_init(xt_dscp_match_init);
module_exit(xt_dscp_match_fini);