| /* IP tables module for matching the value of the IPv4 DSCP field |
| * |
| * ipt_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/netfilter_ipv4/ipt_dscp.h> |
| #include <linux/netfilter_ipv4/ip_tables.h> |
| |
| MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| MODULE_DESCRIPTION("iptables DSCP matching module"); |
| MODULE_LICENSE("GPL"); |
| |
| static int match(const struct sk_buff *skb, const struct net_device *in, |
| const struct net_device *out, const void *matchinfo, |
| int offset, int *hotdrop) |
| { |
| const struct ipt_dscp_info *info = matchinfo; |
| const struct iphdr *iph = skb->nh.iph; |
| |
| u_int8_t sh_dscp = ((info->dscp << IPT_DSCP_SHIFT) & IPT_DSCP_MASK); |
| |
| return ((iph->tos&IPT_DSCP_MASK) == sh_dscp) ^ info->invert; |
| } |
| |
| static int checkentry(const char *tablename, const struct ipt_ip *ip, |
| void *matchinfo, unsigned int matchsize, |
| unsigned int hook_mask) |
| { |
| if (matchsize != IPT_ALIGN(sizeof(struct ipt_dscp_info))) |
| return 0; |
| |
| return 1; |
| } |
| |
| static struct ipt_match dscp_match = { |
| .name = "dscp", |
| .match = &match, |
| .checkentry = &checkentry, |
| .me = THIS_MODULE, |
| }; |
| |
| static int __init init(void) |
| { |
| return ipt_register_match(&dscp_match); |
| } |
| |
| static void __exit fini(void) |
| { |
| ipt_unregister_match(&dscp_match); |
| |
| } |
| |
| module_init(init); |
| module_exit(fini); |