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          *
  93          * Hexadecimal addresses are used because they can easily be extended to
  94          * IPv6 support. To separate the ranges, the return value from this
  95          * function for an IPv6 address will be prefixed with "v6-", a non-
  96          * hexadecimal string which sorts after the IPv4 addresses.
  97          *
  98          * @param $ip Quad dotted IP address.
  99          */
 100         public static function toHex( $ip ) {
 101                 $n = self::toUnsigned( $ip );
 102                 if ( $n !== false ) {
 103                         $n = sprintf( '%08X', $n );
 104                 }
 105                 return $n;
 106         }
 107
 108         /**
 109          * Given an IP address in dotted-quad notation, returns an unsigned integer.
 110          * Like ip2long() except that it actually works and has a consistent error return value.
 111          * Comes from ProxyTools.php
 112          * @param $ip Quad dotted IP address.
 113          */
 114         public static function toUnsigned( $ip ) {
 115                 if ( $ip == '255.255.255.255' ) {
 116                         $n = -1;
 117                 } else {
 118                         $n = ip2long( $ip );
 119                         if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
 120                                 $n = false;
 121                         }
 122                 }
 123                 if ( $n < 0 ) {
 124                         $n += pow( 2, 32 );
 125                 }
 126                 return $n;
 127         }
 128
 129         /**
 130          * Convert a dotted-quad IP to a signed integer
 131          * Returns false on failure
 132          */
 133         public static function toSigned( $ip ) {
 134                 if ( $ip == '255.255.255.255' ) {
 135                         $n = -1;
 136                 } else {
 137                         $n = ip2long( $ip );
 138                         if ( $n == -1 ) {
 139                                 $n = false;
 140                         }
 141                 }
 142                 return $n;
 143         }
 144
 145         /**
 146          * Convert a network specification in CIDR notation to an integer network and a number of bits
 147          */
 148         public static function parseCIDR( $range ) {
 149                 $parts = explode( '/', $range, 2 );
 150                 if ( count( $parts ) != 2 ) {
 151                         return array( false, false );
 152                 }
 153                 $network = IP::toSigned( $parts[0] );
 154                 if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 155                         $bits = $parts[1];
 156                         if ( $bits == 0 ) {
 157                                 $network = 0;
 158                         } else {
 159                                 $network &= ~((1 << (32 - $bits)) - 1);
 160                         }
 161                         # Convert to unsigned
 162                         if ( $network < 0 ) {
 163                                 $network += pow( 2, 32 );
 164                         }
 165                 } else {
 166                         $network = false;
 167                         $bits = false;
 168                 }
 169                 return array( $network, $bits );
 170         }
 171
 172         /**
 173          * Given a string range in a number of formats, return the start and end of
 174          * the range in hexadecimal.
 175          *
 176          * Formats are:
 177          *     1.2.3.4/24          CIDR
 178          *     1.2.3.4 - 1.2.3.5   Explicit range
 179          *     1.2.3.4             Single IP
 180          */
 181         public static function parseRange( $range ) {
 182                 if ( strpos( $range, '/' ) !== false ) {
 183                         # CIDR
 184                         list( $network, $bits ) = IP::parseCIDR( $range );
 185                         if ( $network === false ) {
 186                                 $start = $end = false;
 187                         } else {
 188                                 $start = sprintf( '%08X', $network );
 189                                 $end = sprintf( '%08X', $network + pow( 2, (32 - $bits) ) - 1 );
 190                         }
 191                 } elseif ( strpos( $range, '-' ) !== false ) {
 192                         # Explicit range
 193                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 194                         if ( $start > $end ) {
 195                                 $start = $end = false;
 196                         } else {
 197                                 $start = IP::toHex( $start );
 198                                 $end = IP::toHex( $end );
 199                         }
 200                 } else {
 201                         # Single IP
 202                         $start = $end = IP::toHex( $range );
 203                 }
 204                 if ( $start === false || $end === false ) {
 205                         return array( false, false );
 206                 } else {
 207                         return array( $start, $end );
 208                 }
 209     }
 210
 211     /**
 212      * Determine if a given integer IPv4 address is in a given CIDR network
 213      * @param $addr The address to check against the given range.
 214      * @param $range The range to check the given address against.
 215      * @return bool Whether or not the given address is in the given range.
 216      */
 217     function isInRange( $addr, $range ) {
 218         $unsignedIP = IP::toUnsigned($addr);
 219         list( $start, $end ) = IP::parseRange($range);
 220
 221         return (($unsignedIP >= $start) && ($unsignedIP <= $end));
 222     }
 223 }
 224 ?>