net/netfilter/xt_CLASSIFY.c

   1 /*
   2  * This is a module which is used for setting the skb->priority field
   3  * of an skb for qdisc classification.
   4  */
   5
   6 /* (C) 2001-2002 Patrick McHardy <kaber@trash.net>
   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 #include <linux/ip.h>
  16 #include <net/checksum.h>
  17
  18 #include <linux/netfilter/x_tables.h>
  19 #include <linux/netfilter/xt_CLASSIFY.h>
  20
  21 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  22 MODULE_LICENSE("GPL");
  23 MODULE_DESCRIPTION("iptables qdisc classification target module");
  24 MODULE_ALIAS("ipt_CLASSIFY");
  25
  26 static unsigned int
  27 target(struct sk_buff **pskb,
  28        const struct net_device *in,
  29        const struct net_device *out,
  30        unsigned int hooknum,
  31        const void *targinfo,
  32        void *userinfo)
  33 {
  34         const struct xt_classify_target_info *clinfo = targinfo;
  35
  36         if ((*pskb)->priority != clinfo->priority)
  37                 (*pskb)->priority = clinfo->priority;
  38
  39         return XT_CONTINUE;
  40 }
  41
  42 static int
  43 checkentry(const char *tablename,
  44            const void *e,
  45            void *targinfo,
  46            unsigned int targinfosize,
  47            unsigned int hook_mask)
  48 {
  49         if (targinfosize != XT_ALIGN(sizeof(struct xt_classify_target_info))){
  50                 printk(KERN_ERR "CLASSIFY: invalid size (%u != %Zu).\n",
  51                        targinfosize,
  52                        XT_ALIGN(sizeof(struct xt_classify_target_info)));
  53                 return 0;
  54         }
  55
  56         if (hook_mask & ~((1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_FORWARD) |
  57                           (1 << NF_IP_POST_ROUTING))) {
  58                 printk(KERN_ERR "CLASSIFY: only valid in LOCAL_OUT, FORWARD "
  59                                 "and POST_ROUTING.\n");
  60                 return 0;
  61         }
  62
  63         if (strcmp(tablename, "mangle") != 0) {
  64                 printk(KERN_ERR "CLASSIFY: can only be called from "
  65                                 "\"mangle\" table, not \"%s\".\n",
  66                                 tablename);
  67                 return 0;
  68         }
  69
  70         return 1;
  71 }
  72
  73 static struct xt_target classify_reg = {
  74         .name           = "CLASSIFY",
  75         .target         = target,
  76         .checkentry     = checkentry,
  77         .me             = THIS_MODULE,
  78 };
  79 static struct xt_target classify6_reg = {
  80         .name           = "CLASSIFY",
  81         .target         = target,
  82         .checkentry     = checkentry,
  83         .me             = THIS_MODULE,
  84 };
  85
  86
  87 static int __init init(void)
  88 {
  89         int ret;
  90
  91         ret = xt_register_target(AF_INET, &classify_reg);
  92         if (ret)
  93                 return ret;
  94
  95         ret = xt_register_target(AF_INET6, &classify6_reg);
  96         if (ret)
  97                 xt_unregister_target(AF_INET, &classify_reg);
  98
  99         return ret;
 100 }
 101
 102 static void __exit fini(void)
 103 {
 104         xt_unregister_target(AF_INET, &classify_reg);
 105         xt_unregister_target(AF_INET6, &classify6_reg);
 106 }
 107
 108 module_init(init);
 109 module_exit(fini);