net/netfilter/xt_mark.c

   1 /*
   2  *      xt_mark - Netfilter module to match NFMARK value
   3  *
   4  *      (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
   5  *      Copyright © CC Computer Consultants GmbH, 2007 - 2008
   6  *      Jan Engelhardt <jengelh@computergmbh.de>
   7  *
   8  *      This program is free software; you can redistribute it and/or modify
   9  *      it under the terms of the GNU General Public License version 2 as
  10  *      published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/skbuff.h>
  15
  16 #include <linux/netfilter/xt_mark.h>
  17 #include <linux/netfilter/x_tables.h>
  18
  19 MODULE_LICENSE("GPL");
  20 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
  21 MODULE_DESCRIPTION("Xtables: packet mark match");
  22 MODULE_ALIAS("ipt_mark");
  23 MODULE_ALIAS("ip6t_mark");
  24
  25 static bool
  26 mark_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
  27 {
  28         const struct xt_mark_info *info = par->matchinfo;
  29
  30         return ((skb->mark & info->mask) == info->mark) ^ info->invert;
  31 }
  32
  33 static bool
  34 mark_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  35 {
  36         const struct xt_mark_mtinfo1 *info = par->matchinfo;
  37
  38         return ((skb->mark & info->mask) == info->mark) ^ info->invert;
  39 }
  40
  41 static bool mark_mt_check_v0(const struct xt_mtchk_param *par)
  42 {
  43         const struct xt_mark_info *minfo = par->matchinfo;
  44
  45         if (minfo->mark > 0xffffffff || minfo->mask > 0xffffffff) {
  46                 printk(KERN_WARNING "mark: only supports 32bit mark\n");
  47                 return false;
  48         }
  49         return true;
  50 }
  51
  52 #ifdef CONFIG_COMPAT
  53 struct compat_xt_mark_info {
  54         compat_ulong_t  mark, mask;
  55         u_int8_t        invert;
  56         u_int8_t        __pad1;
  57         u_int16_t       __pad2;
  58 };
  59
  60 static void mark_mt_compat_from_user_v0(void *dst, void *src)
  61 {
  62         const struct compat_xt_mark_info *cm = src;
  63         struct xt_mark_info m = {
  64                 .mark   = cm->mark,
  65                 .mask   = cm->mask,
  66                 .invert = cm->invert,
  67         };
  68         memcpy(dst, &m, sizeof(m));
  69 }
  70
  71 static int mark_mt_compat_to_user_v0(void __user *dst, void *src)
  72 {
  73         const struct xt_mark_info *m = src;
  74         struct compat_xt_mark_info cm = {
  75                 .mark   = m->mark,
  76                 .mask   = m->mask,
  77                 .invert = m->invert,
  78         };
  79         return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
  80 }
  81 #endif /* CONFIG_COMPAT */
  82
  83 static struct xt_match mark_mt_reg[] __read_mostly = {
  84         {
  85                 .name           = "mark",
  86                 .revision       = 0,
  87                 .family         = NFPROTO_UNSPEC,
  88                 .checkentry     = mark_mt_check_v0,
  89                 .match          = mark_mt_v0,
  90                 .matchsize      = sizeof(struct xt_mark_info),
  91 #ifdef CONFIG_COMPAT
  92                 .compatsize     = sizeof(struct compat_xt_mark_info),
  93                 .compat_from_user = mark_mt_compat_from_user_v0,
  94                 .compat_to_user = mark_mt_compat_to_user_v0,
  95 #endif
  96                 .me             = THIS_MODULE,
  97         },
  98         {
  99                 .name           = "mark",
 100                 .revision       = 1,
 101                 .family         = NFPROTO_UNSPEC,
 102                 .match          = mark_mt,
 103                 .matchsize      = sizeof(struct xt_mark_mtinfo1),
 104                 .me             = THIS_MODULE,
 105         },
 106 };
 107
 108 static int __init mark_mt_init(void)
 109 {
 110         return xt_register_matches(mark_mt_reg, ARRAY_SIZE(mark_mt_reg));
 111 }
 112
 113 static void __exit mark_mt_exit(void)
 114 {
 115         xt_unregister_matches(mark_mt_reg, ARRAY_SIZE(mark_mt_reg));
 116 }
 117
 118 module_init(mark_mt_init);
 119 module_exit(mark_mt_exit);