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
  42 mark_mt_check_v0(const char *tablename, const void *entry,
  43                  const struct xt_match *match, void *matchinfo,
  44                  unsigned int hook_mask)
  45 {
  46         const struct xt_mark_info *minfo = matchinfo;
  47
  48         if (minfo->mark > 0xffffffff || minfo->mask > 0xffffffff) {
  49                 printk(KERN_WARNING "mark: only supports 32bit mark\n");
  50                 return false;
  51         }
  52         return true;
  53 }
  54
  55 #ifdef CONFIG_COMPAT
  56 struct compat_xt_mark_info {
  57         compat_ulong_t  mark, mask;
  58         u_int8_t        invert;
  59         u_int8_t        __pad1;
  60         u_int16_t       __pad2;
  61 };
  62
  63 static void mark_mt_compat_from_user_v0(void *dst, void *src)
  64 {
  65         const struct compat_xt_mark_info *cm = src;
  66         struct xt_mark_info m = {
  67                 .mark   = cm->mark,
  68                 .mask   = cm->mask,
  69                 .invert = cm->invert,
  70         };
  71         memcpy(dst, &m, sizeof(m));
  72 }
  73
  74 static int mark_mt_compat_to_user_v0(void __user *dst, void *src)
  75 {
  76         const struct xt_mark_info *m = src;
  77         struct compat_xt_mark_info cm = {
  78                 .mark   = m->mark,
  79                 .mask   = m->mask,
  80                 .invert = m->invert,
  81         };
  82         return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
  83 }
  84 #endif /* CONFIG_COMPAT */
  85
  86 static struct xt_match mark_mt_reg[] __read_mostly = {
  87         {
  88                 .name           = "mark",
  89                 .revision       = 0,
  90                 .family         = NFPROTO_UNSPEC,
  91                 .checkentry     = mark_mt_check_v0,
  92                 .match          = mark_mt_v0,
  93                 .matchsize      = sizeof(struct xt_mark_info),
  94 #ifdef CONFIG_COMPAT
  95                 .compatsize     = sizeof(struct compat_xt_mark_info),
  96                 .compat_from_user = mark_mt_compat_from_user_v0,
  97                 .compat_to_user = mark_mt_compat_to_user_v0,
  98 #endif
  99                 .me             = THIS_MODULE,
 100         },
 101         {
 102                 .name           = "mark",
 103                 .revision       = 1,
 104                 .family         = NFPROTO_UNSPEC,
 105                 .match          = mark_mt,
 106                 .matchsize      = sizeof(struct xt_mark_mtinfo1),
 107                 .me             = THIS_MODULE,
 108         },
 109 };
 110
 111 static int __init mark_mt_init(void)
 112 {
 113         return xt_register_matches(mark_mt_reg, ARRAY_SIZE(mark_mt_reg));
 114 }
 115
 116 static void __exit mark_mt_exit(void)
 117 {
 118         xt_unregister_matches(mark_mt_reg, ARRAY_SIZE(mark_mt_reg));
 119 }
 120
 121 module_init(mark_mt_init);
 122 module_exit(mark_mt_exit);