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][0-9]|1[0-9][0-9]|0?[0-9]?[0-9])');
  14 define( 'RE_IP_ADD' , RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
  15 // An IPv4 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 // For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
  19 define( 'RE_IPV6_WORD', '([0-9A-Fa-f]{1,4})' );
  20 define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
  21 define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );
  22 // An IPv6 block is an IP address and a prefix (d1 to d128)
  23 define( 'RE_IPV6_PREFIX', '(12[0-8]|1[01][0-9]|[1-9]?\d)');
  24 // An IPv6 IP is made up of 8 octets. However abbreviations like "::" can be used. This is lax!
  25 define( 'RE_IPV6_ADD', RE_IPV6_WORD . '(:{1,2}' . RE_IPV6_WORD . '|::$){1,7}' );
  26 define( 'RE_IPV6_BLOCK', RE_IPV6_ADD . '\/' . RE_IPV6_PREFIX );
  27 // This might be useful for regexps used elsewhere, matches any IPv6 or IPv6 address or network
  28 define( 'IP_ADDRESS_STRING', RE_IP_ADD . '(\/' . RE_IP_PREFIX . '|)|' . RE_IPV6_ADD . '(\/' . RE_IPV6_PREFIX . '|)');
  29
  30 class IP {
  31         /**
  32          * Given a string, determine if it as valid IP
  33          * Unlike isValid(), this looks for networks too
  34          * @param $ip IP address.
  35          * @return string
  36          */
  37         public function isIPAddress( $ip ) {
  38                 if ( !$ip ) return false;
  39                 return preg_match( '/^' . IP_ADDRESS_STRING . '$/', $ip);
  40         }
  41
  42         public function isIPv6( $ip ) {
  43                 return preg_match( '/^' . RE_IPV6_ADD . '(\/' . RE_IPV6_PREFIX . '|)$/', $ip);
  44         }
  45
  46         public function isIPv4( $ip ) {
  47                 return preg_match( '/^' . RE_IP_ADD . '(\/' . RE_IP_PREFIX . '|)$/', $ip);
  48         }
  49
  50         /**
  51          * Given an IP address in dotted-quad notation, returns an IPv6 octet.
  52          * See http://www.answers.com/topic/ipv4-compatible-address
  53          * IPs with the first 92 bits as zeros are reserved from IPv6
  54          * @param $ip quad-dotted IP address.
  55          * @return string
  56          */
  57         public function IPv4toIPv6( $ip ) {
  58                 if ( !$ip ) return null;
  59                 // Convert only if needed
  60                 if ( self::isIPv6( $ip ) ) return $ip;
  61                 // IPv4 CIDRs
  62                 if ( strpos( $ip, '/' ) !== false ) {
  63                         $parts = explode( '/', $ip, 2 );
  64                         if ( count( $parts ) != 2 ) {
  65                                 return false;
  66                         }
  67                         $network = self::toUnsigned( $parts[0] );
  68                         if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
  69                                 $bits = $parts[1] + 96;
  70                                 return self::toOctet( $network ) . "/$bits";
  71                         } else {
  72                                 return false;
  73                         }
  74                 }
  75                 return self::toOctet( self::toUnsigned( $ip ) );
  76         }
  77
  78         /**
  79          * Given an IPv6 address in octet notation, returns an unsigned integer.
  80          * @param $ip octet ipv6 IP address.
  81          * @return string
  82          */
  83         public function toUnsigned6( $ip ) {
  84                 if ( !$ip ) return null;
  85         $ip = explode(':', self::expandIP( $ip ) );
  86         $r_ip = '';
  87         foreach ($ip as $v) {
  88                 $r_ip .= wfBaseConvert( $v, 16, 2, 16);
  89         }
  90         return wfBaseConvert($r_ip, 2, 10);
  91         }
  92
  93         /**
  94          * Given an IPv6 address in octet notation, returns the expanded octet.
  95          * @param $ip octet ipv6 IP address.
  96          * @return string
  97          */
  98         public function expandIP( $ip ) {
  99                 if ( !$ip ) return null;
 100                 // Only IPv6 addresses can be expanded
 101                 if ( !self::isIPv6( $ip ) ) return $ip;
 102                 // Expand zero abbreviations
 103                 if ( substr_count($ip, '::') ) {
 104                 $ip = str_replace('::', str_repeat(':0000', 8 - substr_count($ip, ':')) . ':', $ip);
 105         }
 106         return $ip;
 107         }
 108
 109         /**
 110          * Given an unsigned integer, returns an IPv6 address in octet notation
 111          * @param $ip integer IP address.
 112          * @return string
 113          */
 114         public function toOctet( $ip_int ) {
 115                 $ip_int = strval($ip_int);
 116                 // Convert integer to binary
 117                 $ip_int = wfBaseConvert($ip_int, 10, 2, 128);
 118                 // Seperate into 8 octets
 119                 $ip_oct = base_convert( substr( $ip_int, 0, 16 ), 2, 16 );
 120                 for ($n=1; $n < 8; $n++) {
 121                         // Convert to hex, and add ":" marks
 122                         $ip_oct .= ':' . base_convert( substr($ip_int, 16*$n, 16), 2, 16 );
 123                 }
 124         return $ip_oct;
 125         }
 126
 127         /**
 128          * Convert a network specification in IPv6 CIDR notation to an integer network and a number of bits
 129          * @return array(string, int)
 130          */
 131         public static function parseCIDR6( $range ) {
 132                 $parts = explode( '/', $range, 2 );
 133                 if ( count( $parts ) != 2 ) {
 134                         return array( false, false );
 135                 }
 136                 $network = self::toUnsigned6( $parts[0] );
 137                 if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 128 ) {
 138                         $bits = $parts[1];
 139                         if ( $bits == 0 ) {
 140                                 $network = 0;
 141                         } else {
 142                         # Native 32 bit functions WONT work here!!!
 143                         # Convert to a padded binary number
 144                                 $network = wfBaseConvert( $network, 10, 2, 128 );
 145                         # Truncate the last (128-$bits) bits and replace them with zeros
 146                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 147                         # Convert back to an integer
 148                                 $network = wfBaseConvert( $network, 2, 10 );
 149                         }
 150                 } else {
 151                         $network = false;
 152                         $bits = false;
 153                 }
 154
 155                 return array( $network, $bits );
 156         }
 157
 158         /**
 159          * Given a string range in a number of formats, return the start and end of
 160          * the range in hexadecimal. For IPv6.
 161          *
 162          * Formats are:
 163          *     2001:0db8:85a3::7344/96                                   CIDR
 164          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 165          *     2001:0db8:85a3::7344/96                                   Single IP
 166          * @return array(string, int)
 167          */
 168         public static function parseRange6( $range ) {
 169                 if ( strpos( $range, '/' ) !== false ) {
 170                         # CIDR
 171                         list( $network, $bits ) = self::parseCIDR6( $range );
 172                         if ( $network === false ) {
 173                                 $start = $end = false;
 174                         } else {
 175                                 $start = sprintf( '%08X', $network );
 176                                 $end = sprintf( '%08X', $network + pow( 2, (128 - $bits) ) - 1 );
 177                         }
 178                 } elseif ( strpos( $range, '-' ) !== false ) {
 179                         # Explicit range
 180                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 181                         $start = self::toUnsigned6( $start ); $end = self::toUnsigned6( $end );
 182                         if ( $start > $end ) {
 183                                 $start = $end = false;
 184                         } else {
 185                                 $start = sprintf( '%08X', $start );
 186                                 $end = sprintf( '%08X', $end );
 187                         }
 188                 } else {
 189                         # Single IP
 190                         $start = $end = self::toHex( $range );
 191                 }
 192                 if ( $start === false || $end === false ) {
 193                         return array( false, false );
 194                 } else {
 195                         return array( $start, $end );
 196                 }
 197     }
 198
 199         /**
 200          * Validate an IP address.
 201          * @return boolean True if it is valid.
 202          */
 203         public static function isValid( $ip ) {
 204                 return ( preg_match( '/^' . RE_IP_ADD . '$/', $ip) || preg_match( '/^' . RE_IPV6_ADD . '$/', $ip) );
 205         }
 206
 207         /**
 208          * Validate an IP Block.
 209          * @return boolean True if it is valid.
 210          */
 211         public static function isValidBlock( $ipblock ) {
 212                 return ( count(self::toArray($ipblock)) == 1 + 5 );
 213         }
 214
 215         /**
 216          * Determine if an IP address really is an IP address, and if it is public,
 217          * i.e. not RFC 1918 or similar
 218          * Comes from ProxyTools.php
 219          */
 220         public static function isPublic( $ip ) {
 221                 $n = self::toUnsigned( $ip );
 222                 if ( !$n ) {
 223                         return false;
 224                 }
 225
 226                 // ip2long accepts incomplete addresses, as well as some addresses
 227                 // followed by garbage characters. Check that it's really valid.
 228                 if( $ip != long2ip( $n ) ) {
 229                         return false;
 230                 }
 231
 232                 static $privateRanges = false;
 233                 if ( !$privateRanges ) {
 234                         $privateRanges = array(
 235                                 array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 236                                 array( '172.16.0.0',  '172.31.255.255' ),   #     "
 237                                 array( '192.168.0.0', '192.168.255.255' ),  #     "
 238                                 array( '0.0.0.0',     '0.255.255.255' ),    # this network
 239                                 array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 240                         );
 241                 }
 242
 243                 foreach ( $privateRanges as $r ) {
 244                         $start = self::toUnsigned( $r[0] );
 245                         $end = self::toUnsigned( $r[1] );
 246                         if ( $n >= $start && $n <= $end ) {
 247                                 return false;
 248                         }
 249                 }
 250                 return true;
 251         }
 252
 253         /**
 254          * Split out an IP block as an array of 4 bytes and a mask,
 255          * return false if it can't be determined
 256          *
 257          * @parameter $ip string A quad dotted/octet IP address
 258          * @return array
 259          */
 260         public static function toArray( $ipblock ) {
 261                 $matches = array();
 262                 if( preg_match( '/^' . RE_IP_ADD . '(?:\/(?:'.RE_IP_PREFIX.'))?' . '$/', $ipblock, $matches ) ) {
 263                         return $matches;
 264                 } else if ( preg_match( '/^' . RE_IPV6_ADD . '(?:\/(?:'.RE_IPV6_PREFIX.'))?' . '$/', $ipblock, $matches ) ) {
 265                         return $matches;
 266                 } else {
 267                         return false;
 268                 }
 269         }
 270
 271         /**
 272          * Return a zero-padded hexadecimal representation of an IP address.
 273          *
 274          * Hexadecimal addresses are used because they can easily be extended to
 275          * IPv6 support. To separate the ranges, the return value from this
 276          * function for an IPv6 address will be prefixed with "v6-", a non-
 277          * hexadecimal string which sorts after the IPv4 addresses.
 278          *
 279          * @param $ip Quad dotted IP address.
 280          * @return hexidecimal
 281          */
 282         public static function toHex( $ip ) {
 283                 // Use IPv6 functions if needed
 284                 $n = ( self::isIPv6($ip) ) ? self::toUnsigned6( $ip ) : self::toUnsigned( $ip );
 285                 if ( $n !== false ) {
 286                         $n = sprintf( '%08X', $n );
 287                 }
 288                 return $n;
 289         }
 290
 291         /**
 292          * Given an IP address in dotted-quad notation, returns an unsigned integer.
 293          * Like ip2long() except that it actually works and has a consistent error return value.
 294          * Comes from ProxyTools.php
 295          * @param $ip Quad dotted IP address.
 296          * @return integer
 297          */
 298         public static function toUnsigned( $ip ) {
 299                 // Use IPv6 functions if needed
 300                 if ( self::isIPv6( $ip ) ) {
 301                         return toUnsigned6( $ip );
 302                 }
 303                 if ( $ip == '255.255.255.255' ) {
 304                         $n = -1;
 305                 } else {
 306                         $n = ip2long( $ip );
 307                         if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
 308                                 $n = false;
 309                         }
 310                 }
 311                 if ( $n < 0 ) {
 312                         $n += pow( 2, 32 );
 313                 }
 314                 return $n;
 315         }
 316
 317         /**
 318          * Convert a dotted-quad IP to a signed integer
 319          * Returns false on failure
 320          */
 321         public static function toSigned( $ip ) {
 322                 if ( $ip == '255.255.255.255' ) {
 323                         $n = -1;
 324                 } else {
 325                         $n = ip2long( $ip );
 326                         if ( $n == -1 ) {
 327                                 $n = false;
 328                         }
 329                 }
 330                 return $n;
 331         }
 332
 333         /**
 334          * Convert a network specification in CIDR notation to an integer network and a number of bits
 335          * @return array(string, int)
 336          */
 337         public static function parseCIDR( $range ) {
 338                 $parts = explode( '/', $range, 2 );
 339                 if ( count( $parts ) != 2 ) {
 340                         return array( false, false );
 341                 }
 342                 $network = self::toSigned( $parts[0] );
 343                 if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 344                         $bits = $parts[1];
 345                         if ( $bits == 0 ) {
 346                                 $network = 0;
 347                         } else {
 348                                 $network &= ~((1 << (32 - $bits)) - 1);
 349                         }
 350                         # Convert to unsigned
 351                         if ( $network < 0 ) {
 352                                 $network += pow( 2, 32 );
 353                         }
 354                 } else {
 355                         $network = false;
 356                         $bits = false;
 357                 }
 358                 return array( $network, $bits );
 359         }
 360
 361         /**
 362          * Given a string range in a number of formats, return the start and end of
 363          * the range in hexadecimal. For IPv4.
 364          *
 365          * Formats are:
 366          *     1.2.3.4/24          CIDR
 367          *     1.2.3.4 - 1.2.3.5   Explicit range
 368          *     1.2.3.4             Single IP
 369          * @return array(string, int)
 370          */
 371         public static function parseRange( $range ) {
 372                 // Use IPv6 functions if needed
 373                 if ( self::isIPv6( $range ) ) {
 374                         return self::parseRange6( $range );
 375                 }
 376                 if ( strpos( $range, '/' ) !== false ) {
 377                         # CIDR
 378                         list( $network, $bits ) = self::parseCIDR( $range );
 379                         if ( $network === false ) {
 380                                 $start = $end = false;
 381                         } else {
 382                                 $start = sprintf( '%08X', $network );
 383                                 $end = sprintf( '%08X', $network + pow( 2, (32 - $bits) ) - 1 );
 384                         }
 385                 } elseif ( strpos( $range, '-' ) !== false ) {
 386                         # Explicit range
 387                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 388                         $start = self::toUnsigned( $start ); $end = self::toUnsigned( $end );
 389                         if ( $start > $end ) {
 390                                 $start = $end = false;
 391                         } else {
 392                                 $start = sprintf( '%08X', $start );
 393                                 $end = sprintf( '%08X', $end );
 394                         }
 395                 } else {
 396                         # Single IP
 397                         $start = $end = self::toHex( $range );
 398                 }
 399                 if ( $start === false || $end === false ) {
 400                         return array( false, false );
 401                 } else {
 402                         return array( $start, $end );
 403                 }
 404     }
 405
 406     /**
 407      * Determine if a given IPv4 address is in a given CIDR network
 408      * @param $addr The address to check against the given range.
 409      * @param $range The range to check the given address against.
 410      * @return bool Whether or not the given address is in the given range.
 411      */
 412     public static function isInRange( $addr, $range ) {
 413     // Convert to IPv6 if needed
 414         $unsignedIP = self::toUnsigned6( self::IPv4toIPv6($addr) );
 415         list( $start, $end ) = self::parseRange6( self::IPv4toIPv6($range) );
 416         return (($unsignedIP >= $start) && ($unsignedIP <= $end));
 417     }
 418
 419     /**
 420      * Convert some unusual representations of IPv4 addresses to their
 421      * canonical dotted quad representation.
 422      *
 423      * This currently only checks a few IPV4-to-IPv6 related cases.  More
 424      * unusual representations may be added later.
 425      *
 426      * @param $addr something that might be an IP address
 427      * @return valid dotted quad IPv4 address or null
 428      */
 429     public static function canonicalize( $addr ) {
 430         if ( self::isValid( $addr ) )
 431             return $addr;
 432
 433         // IPv6 loopback address
 434         $m = array();
 435         if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) )
 436             return '127.0.0.1';
 437
 438         // IPv4-mapped and IPv4-compatible IPv6 addresses
 439         if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) )
 440             return $m[1];
 441         if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD . ':' . RE_IPV6_WORD . '$/i', $addr, $m ) )
 442             return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 443
 444         return null;  // give up
 445     }
 446 }
 447
 448 ?>