Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* IP tables module for matching the value of the IPv4 DSCP field |
2 | * | |
3 | * ipt_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 | ||
15 | #include <linux/netfilter_ipv4/ipt_dscp.h> | |
16 | #include <linux/netfilter_ipv4/ip_tables.h> | |
17 | ||
18 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
19 | MODULE_DESCRIPTION("iptables DSCP matching module"); | |
20 | MODULE_LICENSE("GPL"); | |
21 | ||
22 | static int match(const struct sk_buff *skb, const struct net_device *in, | |
23 | const struct net_device *out, const void *matchinfo, | |
24 | int offset, int *hotdrop) | |
25 | { | |
26 | const struct ipt_dscp_info *info = matchinfo; | |
27 | const struct iphdr *iph = skb->nh.iph; | |
28 | ||
29 | u_int8_t sh_dscp = ((info->dscp << IPT_DSCP_SHIFT) & IPT_DSCP_MASK); | |
30 | ||
31 | return ((iph->tos&IPT_DSCP_MASK) == sh_dscp) ^ info->invert; | |
32 | } | |
33 | ||
34 | static int checkentry(const char *tablename, const struct ipt_ip *ip, | |
35 | void *matchinfo, unsigned int matchsize, | |
36 | unsigned int hook_mask) | |
37 | { | |
38 | if (matchsize != IPT_ALIGN(sizeof(struct ipt_dscp_info))) | |
39 | return 0; | |
40 | ||
41 | return 1; | |
42 | } | |
43 | ||
44 | static struct ipt_match dscp_match = { | |
45 | .name = "dscp", | |
46 | .match = &match, | |
47 | .checkentry = &checkentry, | |
48 | .me = THIS_MODULE, | |
49 | }; | |
50 | ||
51 | static int __init init(void) | |
52 | { | |
53 | return ipt_register_match(&dscp_match); | |
54 | } | |
55 | ||
56 | static void __exit fini(void) | |
57 | { | |
58 | ipt_unregister_match(&dscp_match); | |
59 | ||
60 | } | |
61 | ||
62 | module_init(init); | |
63 | module_exit(fini); |