linux/net/netfilter/xt_dscp.c
<<
>>
Prefs
   1/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
   2 *
   3 * (C) 2002 by Harald Welte <laforge@netfilter.org>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/skbuff.h>
  12#include <linux/ip.h>
  13#include <linux/ipv6.h>
  14#include <net/dsfield.h>
  15
  16#include <linux/netfilter/x_tables.h>
  17#include <linux/netfilter/xt_dscp.h>
  18#include <linux/netfilter_ipv4/ipt_tos.h>
  19
  20MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  21MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
  22MODULE_LICENSE("GPL");
  23MODULE_ALIAS("ipt_dscp");
  24MODULE_ALIAS("ip6t_dscp");
  25MODULE_ALIAS("ipt_tos");
  26MODULE_ALIAS("ip6t_tos");
  27
  28static bool
  29dscp_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  30{
  31        const struct xt_dscp_info *info = par->matchinfo;
  32        u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
  33
  34        return (dscp == info->dscp) ^ !!info->invert;
  35}
  36
  37static bool
  38dscp_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
  39{
  40        const struct xt_dscp_info *info = par->matchinfo;
  41        u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
  42
  43        return (dscp == info->dscp) ^ !!info->invert;
  44}
  45
  46static bool dscp_mt_check(const struct xt_mtchk_param *par)
  47{
  48        const struct xt_dscp_info *info = par->matchinfo;
  49
  50        if (info->dscp > XT_DSCP_MAX) {
  51                printk(KERN_ERR "xt_dscp: dscp %x out of range\n", info->dscp);
  52                return false;
  53        }
  54
  55        return true;
  56}
  57
  58static bool
  59tos_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
  60{
  61        const struct ipt_tos_info *info = par->matchinfo;
  62
  63        return (ip_hdr(skb)->tos == info->tos) ^ info->invert;
  64}
  65
  66static bool tos_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  67{
  68        const struct xt_tos_match_info *info = par->matchinfo;
  69
  70        if (par->match->family == NFPROTO_IPV4)
  71                return ((ip_hdr(skb)->tos & info->tos_mask) ==
  72                       info->tos_value) ^ !!info->invert;
  73        else
  74                return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
  75                       info->tos_value) ^ !!info->invert;
  76}
  77
  78static struct xt_match dscp_mt_reg[] __read_mostly = {
  79        {
  80                .name           = "dscp",
  81                .family         = NFPROTO_IPV4,
  82                .checkentry     = dscp_mt_check,
  83                .match          = dscp_mt,
  84                .matchsize      = sizeof(struct xt_dscp_info),
  85                .me             = THIS_MODULE,
  86        },
  87        {
  88                .name           = "dscp",
  89                .family         = NFPROTO_IPV6,
  90                .checkentry     = dscp_mt_check,
  91                .match          = dscp_mt6,
  92                .matchsize      = sizeof(struct xt_dscp_info),
  93                .me             = THIS_MODULE,
  94        },
  95        {
  96                .name           = "tos",
  97                .revision       = 0,
  98                .family         = NFPROTO_IPV4,
  99                .match          = tos_mt_v0,
 100                .matchsize      = sizeof(struct ipt_tos_info),
 101                .me             = THIS_MODULE,
 102        },
 103        {
 104                .name           = "tos",
 105                .revision       = 1,
 106                .family         = NFPROTO_IPV4,
 107                .match          = tos_mt,
 108                .matchsize      = sizeof(struct xt_tos_match_info),
 109                .me             = THIS_MODULE,
 110        },
 111        {
 112                .name           = "tos",
 113                .revision       = 1,
 114                .family         = NFPROTO_IPV6,
 115                .match          = tos_mt,
 116                .matchsize      = sizeof(struct xt_tos_match_info),
 117                .me             = THIS_MODULE,
 118        },
 119};
 120
 121static int __init dscp_mt_init(void)
 122{
 123        return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
 124}
 125
 126static void __exit dscp_mt_exit(void)
 127{
 128        xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
 129}
 130
 131module_init(dscp_mt_init);
 132module_exit(dscp_mt_exit);
 133