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Linux kernel mirror (for testing)
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linux
1/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
2 *
3 * xt_dscp.c,v 1.3 2002/08/05 19:00:21 laforge Exp
4 *
5 * (C) 2002 by Harald Welte <laforge@netfilter.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/skbuff.h>
14#include <linux/ip.h>
15#include <linux/ipv6.h>
16#include <net/dsfield.h>
17
18#include <linux/netfilter/xt_dscp.h>
19#include <linux/netfilter/x_tables.h>
20
21MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
22MODULE_DESCRIPTION("x_tables DSCP matching module");
23MODULE_LICENSE("GPL");
24MODULE_ALIAS("ipt_dscp");
25MODULE_ALIAS("ip6t_dscp");
26
27static int match(const struct sk_buff *skb,
28 const struct net_device *in,
29 const struct net_device *out,
30 const struct xt_match *match,
31 const void *matchinfo,
32 int offset,
33 unsigned int protoff,
34 int *hotdrop)
35{
36 const struct xt_dscp_info *info = matchinfo;
37 u_int8_t dscp = ipv4_get_dsfield(skb->nh.iph) >> XT_DSCP_SHIFT;
38
39 return (dscp == info->dscp) ^ !!info->invert;
40}
41
42static int match6(const struct sk_buff *skb,
43 const struct net_device *in,
44 const struct net_device *out,
45 const struct xt_match *match,
46 const void *matchinfo,
47 int offset,
48 unsigned int protoff,
49 int *hotdrop)
50{
51 const struct xt_dscp_info *info = matchinfo;
52 u_int8_t dscp = ipv6_get_dsfield(skb->nh.ipv6h) >> XT_DSCP_SHIFT;
53
54 return (dscp == info->dscp) ^ !!info->invert;
55}
56
57static int checkentry(const char *tablename,
58 const void *info,
59 const struct xt_match *match,
60 void *matchinfo,
61 unsigned int hook_mask)
62{
63 const u_int8_t dscp = ((struct xt_dscp_info *)matchinfo)->dscp;
64
65 if (dscp > XT_DSCP_MAX) {
66 printk(KERN_ERR "xt_dscp: dscp %x out of range\n", dscp);
67 return 0;
68 }
69
70 return 1;
71}
72
73static struct xt_match xt_dscp_match[] = {
74 {
75 .name = "dscp",
76 .family = AF_INET,
77 .checkentry = checkentry,
78 .match = match,
79 .matchsize = sizeof(struct xt_dscp_info),
80 .me = THIS_MODULE,
81 },
82 {
83 .name = "dscp",
84 .family = AF_INET6,
85 .checkentry = checkentry,
86 .match = match6,
87 .matchsize = sizeof(struct xt_dscp_info),
88 .me = THIS_MODULE,
89 },
90};
91
92static int __init xt_dscp_match_init(void)
93{
94 return xt_register_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match));
95}
96
97static void __exit xt_dscp_match_fini(void)
98{
99 xt_unregister_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match));
100}
101
102module_init(xt_dscp_match_init);
103module_exit(xt_dscp_match_fini);