| /* 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 matchsize, |
| 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 dscp_match = { |
| .name = "dscp", |
| .match = match, |
| .checkentry = checkentry, |
| .matchsize = sizeof(struct xt_dscp_info), |
| .family = AF_INET, |
| .me = THIS_MODULE, |
| }; |
| |
| static struct xt_match dscp6_match = { |
| .name = "dscp", |
| .match = match6, |
| .checkentry = checkentry, |
| .matchsize = sizeof(struct xt_dscp_info), |
| .family = AF_INET6, |
| .me = THIS_MODULE, |
| }; |
| |
| static int __init xt_dscp_match_init(void) |
| { |
| int ret; |
| ret = xt_register_match(&dscp_match); |
| if (ret) |
| return ret; |
| |
| ret = xt_register_match(&dscp6_match); |
| if (ret) |
| xt_unregister_match(&dscp_match); |
| |
| return ret; |
| } |
| |
| static void __exit xt_dscp_match_fini(void) |
| { |
| xt_unregister_match(&dscp_match); |
| xt_unregister_match(&dscp6_match); |
| } |
| |
| module_init(xt_dscp_match_init); |
| module_exit(xt_dscp_match_fini); |