net/netfilter/xt_MARK.c

   1 /* This is a module which is used for setting the NFMARK field of an skb. */
   2
   3 /* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
   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 <net/checksum.h>
  14
  15 #include <linux/netfilter/x_tables.h>
  16 #include <linux/netfilter/xt_MARK.h>
  17
  18 MODULE_LICENSE("GPL");
  19 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
  20 MODULE_DESCRIPTION("ip[6]tables MARK modification module");
  21 MODULE_ALIAS("ipt_MARK");
  22 MODULE_ALIAS("ip6t_MARK");
  23
  24 static unsigned int
  25 target_v0(struct sk_buff **pskb,
  26           const struct net_device *in,
  27           const struct net_device *out,
  28           unsigned int hooknum,
  29           const struct xt_target *target,
  30           const void *targinfo)
  31 {
  32         const struct xt_mark_target_info *markinfo = targinfo;
  33
  34         if((*pskb)->nfmark != markinfo->mark)
  35                 (*pskb)->nfmark = markinfo->mark;
  36
  37         return XT_CONTINUE;
  38 }
  39
  40 static unsigned int
  41 target_v1(struct sk_buff **pskb,
  42           const struct net_device *in,
  43           const struct net_device *out,
  44           unsigned int hooknum,
  45           const struct xt_target *target,
  46           const void *targinfo)
  47 {
  48         const struct xt_mark_target_info_v1 *markinfo = targinfo;
  49         int mark = 0;
  50
  51         switch (markinfo->mode) {
  52         case XT_MARK_SET:
  53                 mark = markinfo->mark;
  54                 break;
  55
  56         case XT_MARK_AND:
  57                 mark = (*pskb)->nfmark & markinfo->mark;
  58                 break;
  59
  60         case XT_MARK_OR:
  61                 mark = (*pskb)->nfmark | markinfo->mark;
  62                 break;
  63         }
  64
  65         if((*pskb)->nfmark != mark)
  66                 (*pskb)->nfmark = mark;
  67
  68         return XT_CONTINUE;
  69 }
  70
  71
  72 static int
  73 checkentry_v0(const char *tablename,
  74               const void *entry,
  75               const struct xt_target *target,
  76               void *targinfo,
  77               unsigned int targinfosize,
  78               unsigned int hook_mask)
  79 {
  80         struct xt_mark_target_info *markinfo = targinfo;
  81
  82         if (markinfo->mark > 0xffffffff) {
  83                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
  84                 return 0;
  85         }
  86         return 1;
  87 }
  88
  89 static int
  90 checkentry_v1(const char *tablename,
  91               const void *entry,
  92               const struct xt_target *target,
  93               void *targinfo,
  94               unsigned int targinfosize,
  95               unsigned int hook_mask)
  96 {
  97         struct xt_mark_target_info_v1 *markinfo = targinfo;
  98
  99         if (markinfo->mode != XT_MARK_SET
 100             && markinfo->mode != XT_MARK_AND
 101             && markinfo->mode != XT_MARK_OR) {
 102                 printk(KERN_WARNING "MARK: unknown mode %u\n",
 103                        markinfo->mode);
 104                 return 0;
 105         }
 106         if (markinfo->mark > 0xffffffff) {
 107                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
 108                 return 0;
 109         }
 110         return 1;
 111 }
 112
 113 static struct xt_target xt_mark_target[] = {
 114         {
 115                 .name           = "MARK",
 116                 .family         = AF_INET,
 117                 .revision       = 0,
 118                 .checkentry     = checkentry_v0,
 119                 .target         = target_v0,
 120                 .targetsize     = sizeof(struct xt_mark_target_info),
 121                 .table          = "mangle",
 122                 .me             = THIS_MODULE,
 123         },
 124         {
 125                 .name           = "MARK",
 126                 .family         = AF_INET,
 127                 .revision       = 1,
 128                 .checkentry     = checkentry_v1,
 129                 .target         = target_v1,
 130                 .targetsize     = sizeof(struct xt_mark_target_info_v1),
 131                 .table          = "mangle",
 132                 .me             = THIS_MODULE,
 133         },
 134         {
 135                 .name           = "MARK",
 136                 .family         = AF_INET6,
 137                 .revision       = 0,
 138                 .checkentry     = checkentry_v0,
 139                 .target         = target_v0,
 140                 .targetsize     = sizeof(struct xt_mark_target_info),
 141                 .table          = "mangle",
 142                 .me             = THIS_MODULE,
 143         },
 144 };
 145
 146 static int __init xt_mark_init(void)
 147 {
 148         return xt_register_targets(xt_mark_target, ARRAY_SIZE(xt_mark_target));
 149 }
 150
 151 static void __exit xt_mark_fini(void)
 152 {
 153         xt_unregister_targets(xt_mark_target, ARRAY_SIZE(xt_mark_target));
 154 }
 155
 156 module_init(xt_mark_init);
 157 module_exit(xt_mark_fini);