includes/IP.php

   1 <?php
   2 /*
   3  * Collection of public static functions to play with IP address
   4  * and IP blocks.
   5  *
   6  * @Author "Ashar Voultoiz" <hashar@altern.org>
   7  * @License GPL v2 or later
   8  */
   9
  10 // Some regex definition to "play" with IP address and IP address blocks
  11
  12 // An IP is made of 4 bytes from x00 to xFF which is d0 to d255
  13 define( 'RE_IP_BYTE', '(25[0-5]|2[0-4]\d|1?\d{1,2})');
  14 define( 'RE_IP_ADD' , RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
  15 // An IP block is an IP address and a prefix (d1 to d32)
  16 define( 'RE_IP_PREFIX' , '(3[0-2]|[12]?\d)');
  17 define( 'RE_IP_BLOCK', RE_IP_ADD . '\/' . RE_IP_PREFIX);
  18
  19 class IP {
  20
  21         /**
  22          * Validate an IP address.
  23          * @return boolean True if it is valid.
  24          */
  25         public static function isValid( $ip ) {
  26                 return preg_match( '/^' . RE_IP_ADD . '$/', $ip, $matches) ;
  27         }
  28
  29         /**
  30          * Validate an IP Block.
  31          * @return boolean True if it is valid.
  32          */
  33         public static function isValidBlock( $ipblock ) {
  34                 return ( count(self::toArray($ipblock)) == 1 + 5 );
  35         }
  36
  37         /**
  38          * Determine if an IP address really is an IP address, and if it is public,
  39          * i.e. not RFC 1918 or similar
  40          * Comes from ProxyTools.php
  41          */
  42         public static function isPublic( $ip ) {
  43                 $n = IP::toUnsigned( $ip );
  44                 if ( !$n ) {
  45                         return false;
  46                 }
  47
  48                 // ip2long accepts incomplete addresses, as well as some addresses
  49                 // followed by garbage characters. Check that it's really valid.
  50                 if( $ip != long2ip( $n ) ) {
  51                         return false;
  52                 }
  53
  54                 static $privateRanges = false;
  55                 if ( !$privateRanges ) {
  56                         $privateRanges = array(
  57                                 array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
  58                                 array( '172.16.0.0',  '172.31.255.255' ),   #     "
  59                                 array( '192.168.0.0', '192.168.255.255' ),  #     "
  60                                 array( '0.0.0.0',     '0.255.255.255' ),    # this network
  61                                 array( '127.0.0.0',   '127.255.255.255' ),  # loopback
  62                         );
  63                 }
  64
  65                 foreach ( $privateRanges as $r ) {
  66                         $start = IP::toUnsigned( $r[0] );
  67                         $end = IP::toUnsigned( $r[1] );
  68                         if ( $n >= $start && $n <= $end ) {
  69                                 return false;
  70                         }
  71                 }
  72                 return true;
  73         }
  74
  75         /**
  76          * Split out an IP block as an array of 4 bytes and a mask,
  77          * return false if it cant be determined
  78          *
  79          * @parameter $ip string A quad dotted IP address
  80          * @return array
  81          */
  82         public static function toArray( $ipblock ) {
  83                 if(! preg_match( '/^' . RE_IP_ADD . '(?:\/(?:'.RE_IP_PREFIX.'))?' . '$/', $ipblock, $matches ) ) {
  84                         return false;
  85                 } else {
  86                         return $matches;
  87                 }
  88         }
  89
  90         /**
  91          * Return a zero-padded hexadecimal representation of an IP address
  92          * Comes from ProxyTools.php
  93          * @param $ip Quad dotted IP address.
  94          */
  95         public static function toHex( $ip ) {
  96                 $n = self::toUnsigned( $ip );
  97                 if ( $n !== false ) {
  98                         $n = sprintf( '%08X', $n );
  99                 }
 100                 return $n;
 101         }
 102
 103         /**
 104          * Given an IP address in dotted-quad notation, returns an unsigned integer.
 105          * Like ip2long() except that it actually works and has a consistent error return value.
 106          * Comes from ProxyTools.php
 107          * @param $ip Quad dotted IP address.
 108          */
 109         public static function toUnsigned( $ip ) {
 110                 $n = ip2long( $ip );
 111                 if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
 112                         $n = false;
 113                 } elseif ( $n < 0 ) {
 114                         $n += pow( 2, 32 );
 115                 }
 116                 return $n;
 117         }
 118 }
 119 ?>