release/src-rt-6.x.4708/linux/linux-2.6.36/net/netfilter/xt_ethport.c

   1 /*
   2  * IP tables module for matching the value of the incoming ether port
   3  * for Ralink SoC platform.
   4  *
   5  * (C) 2009 by Y.Y. Huang <yy_huang@ralinktech.com.tw>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/ip.h>
  15 #include <linux/ipv6.h>
  16
  17 #include <linux/netfilter/xt_ethport.h>
  18 #include <linux/netfilter/x_tables.h>
  19
  20 MODULE_AUTHOR("Y.Y. Huang <yy_huang@ralinktech.com.tw>");
  21 MODULE_DESCRIPTION("x_tables Ra SoC Ethernet incoming port matching module");
  22 MODULE_LICENSE("GPL");
  23 MODULE_ALIAS("ipt_ethport");
  24 MODULE_ALIAS("ip6t_ethport");
  25
  26 static bool match(const struct sk_buff *skb, struct xt_action_param *par)
  27 {
  28         const struct xt_ethport_info *info = par->matchinfo;
  29         u_int8_t portnum = skb->priority;
  30
  31         return (portnum == info->portnum) ^ !!info->invert;
  32 }
  33
  34 static bool match6(const struct sk_buff *skb, struct xt_action_param *par)
  35 {
  36         const struct xt_ethport_info *info = par->matchinfo;
  37         u_int8_t portnum = skb->priority;
  38
  39         return (portnum == info->portnum) ^ !!info->invert;
  40 }
  41
  42 static int checkentry(const struct xt_mtchk_param *par)
  43 {
  44         const u_int8_t portnum = ((struct xt_ethport_info *)(par->matchinfo))->portnum;
  45
  46         if (portnum > XT_ETHPORT_MAX) {
  47                 printk(KERN_ERR "xt_ethport: port number %x is out of range(%x)\n", portnum, XT_ETHPORT_MAX);
  48                 return -EINVAL;
  49         }
  50
  51         return 0;
  52 }
  53
  54 static struct xt_match xt_ethport_match[] = {
  55         {
  56                 .name           = "ethport",
  57                 .family         = AF_INET,
  58                 .checkentry     = checkentry,
  59                 .match          = match,
  60                 .matchsize      = sizeof(struct xt_ethport_info),
  61                 .me             = THIS_MODULE,
  62         },
  63         {
  64                 .name           = "ethport",
  65                 .family         = AF_INET6,
  66                 .checkentry     = checkentry,
  67                 .match          = match6,
  68                 .matchsize      = sizeof(struct xt_ethport_info),
  69                 .me             = THIS_MODULE,
  70         },
  71 };
  72
  73 static int __init xt_ethport_match_init(void)
  74 {
  75         return xt_register_matches(xt_ethport_match, ARRAY_SIZE(xt_ethport_match));
  76 }
  77
  78 static void __exit xt_ethport_match_fini(void)
  79 {
  80         xt_unregister_matches(xt_ethport_match, ARRAY_SIZE(xt_ethport_match));
  81 }
  82
  83 module_init(xt_ethport_match_init);
  84 module_exit(xt_ethport_match_fini);