includes/IP.php

   1 <?php
   2 /**
   3  * Functions and constants to play with IP addresses and ranges
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Ashar Voultoiz <hashar at free dot fr>, Aaron Schulz
  22  */
  23
  24 // Some regex definition to "play" with IP address and IP address blocks
  25
  26 // An IPv4 address is made of 4 bytes from x00 to xFF which is d0 to d255
  27 define( 'RE_IP_BYTE', '(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|0?[0-9]?[0-9])' );
  28 define( 'RE_IP_ADD' , RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
  29 // An IPv4 block is an IP address and a prefix (d1 to d32)
  30 define( 'RE_IP_PREFIX', '(3[0-2]|[12]?\d)' );
  31 define( 'RE_IP_BLOCK', RE_IP_ADD . '\/' . RE_IP_PREFIX );
  32
  33 // An IPv6 address is made up of 8 words (each x0000 to xFFFF).
  34 // However, the "::" abbreviation can be used on consecutive x0000 words.
  35 define( 'RE_IPV6_WORD', '([0-9A-Fa-f]{1,4})' );
  36 define( 'RE_IPV6_PREFIX', '(12[0-8]|1[01][0-9]|[1-9]?\d)');
  37 define( 'RE_IPV6_ADD',
  38         '(' . // starts with "::" (includes the address "::")
  39                 '(::|:(:' . RE_IPV6_WORD . '){1,7})' .
  40         '|' . // ends with "::" (not including the address "::")
  41                 RE_IPV6_WORD . '(:' . RE_IPV6_WORD . '){0,6}::' .
  42         '|' . // has no "::"
  43                 RE_IPV6_WORD . '(:' . RE_IPV6_WORD . '){7}' .
  44         '|' . // contains one "::" in the middle ("^" check always fails if no "::" found)
  45                 RE_IPV6_WORD . '(:(?P<abbr>(?(abbr)|:))?' . RE_IPV6_WORD . '){1,6}(?(abbr)|^)' .
  46         ')'
  47 );
  48 // An IPv6 block is an IP address and a prefix (d1 to d128)
  49 define( 'RE_IPV6_BLOCK', RE_IPV6_ADD . '\/' . RE_IPV6_PREFIX );
  50 // For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
  51 define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
  52 define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );
  53
  54 // This might be useful for regexps used elsewhere, matches any IPv6 or IPv6 address or network
  55 define( 'IP_ADDRESS_STRING',
  56         '(?:' .
  57                 RE_IP_ADD . '(\/' . RE_IP_PREFIX . '|)' . // IPv4
  58         '|' .
  59                 RE_IPV6_ADD . '(\/' . RE_IPV6_PREFIX . '|)' . // IPv6
  60         ')'
  61 );
  62
  63 /**
  64  * A collection of public static functions to play with IP address
  65  * and IP blocks.
  66  */
  67 class IP {
  68         /**
  69          * Determine if a string is as valid IP address or network (CIDR prefix).
  70          * SIIT IPv4-translated addresses are rejected.
  71          * Note: canonicalize() tries to convert translated addresses to IPv4.
  72          * @param string $ip possible IP address
  73          * @return bool
  74          */
  75         public static function isIPAddress( $ip ) {
  76                 return (bool)preg_match( '/^' . IP_ADDRESS_STRING . '$/', $ip );
  77         }
  78
  79         /**
  80          * Given a string, determine if it as valid IP in IPv6 only.
  81          * Note: Unlike isValid(), this looks for networks too.
  82          * @param string $ip possible IP address
  83          * @return bool
  84          */
  85         public static function isIPv6( $ip ) {
  86                 return (bool)preg_match( '/^' . RE_IPV6_ADD . '(\/' . RE_IPV6_PREFIX . '|)$/', $ip );
  87         }
  88
  89         /**
  90          * Given a string, determine if it as valid IP in IPv4 only.
  91          * Note: Unlike isValid(), this looks for networks too.
  92          * @param string $ip possible IP address
  93          * @return bool
  94          */
  95         public static function isIPv4( $ip ) {
  96                 return (bool)preg_match( '/^' . RE_IP_ADD . '(\/' . RE_IP_PREFIX . '|)$/', $ip );
  97         }
  98
  99         /**
 100          * Validate an IP address. Ranges are NOT considered valid.
 101          * SIIT IPv4-translated addresses are rejected.
 102          * Note: canonicalize() tries to convert translated addresses to IPv4.
 103          * @param string $ip
 104          * @return boolean True if it is valid.
 105          */
 106         public static function isValid( $ip ) {
 107                 return ( preg_match( '/^' . RE_IP_ADD . '$/', $ip )
 108                         || preg_match( '/^' . RE_IPV6_ADD . '$/', $ip ) );
 109         }
 110
 111         /**
 112          * Validate an IP Block (valid address WITH a valid prefix).
 113          * SIIT IPv4-translated addresses are rejected.
 114          * Note: canonicalize() tries to convert translated addresses to IPv4.
 115          * @param string $ipblock
 116          * @return boolean True if it is valid.
 117          */
 118         public static function isValidBlock( $ipblock ) {
 119                 return ( preg_match( '/^' . RE_IPV6_BLOCK . '$/', $ipblock )
 120                         || preg_match( '/^' . RE_IP_BLOCK . '$/', $ipblock ) );
 121         }
 122
 123         /**
 124          * Given an IP address in dotted-quad notation, returns an IPv6 octet.
 125          * See http://www.answers.com/topic/ipv4-compatible-address
 126          * IPs with the first 92 bits as zeros are reserved from IPv6
 127          * @param string $ip quad-dotted IP address.
 128          * @return string IPv4 address
 129          */
 130         public static function IPv4toIPv6( $ip ) {
 131                 if ( !self::isIPv4( $ip ) ) {
 132                         throw new MWException( "IPv4toIPv6() called on a non-IPv4 address." );
 133                 }
 134                 // IPv4 address with CIDR
 135                 if ( strpos( $ip, '/' ) !== false ) {
 136                         $parts = explode( '/', $ip, 2 );
 137                         if ( count( $parts ) != 2 ) {
 138                                 return false;
 139                         }
 140                         list( $network, $bits ) = $parts;
 141                         $network = self::toUnsigned( $network );
 142                         if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 143                                 $bits += 96;
 144                                 return self::toOctet( $network ) . "/$bits";
 145                         } else {
 146                                 return false;
 147                         }
 148                 }
 149                 return self::toOctet( self::toUnsigned( $ip ) );
 150         }
 151
 152         /**
 153          * Convert an IP into a nice standard form.
 154          * IPv6 addresses in octet notation are expanded to 8 words.
 155          * IPv4 addresses are just trimmed.
 156          * @param string $ip IP address in quad or octet form (CIDR or not).
 157          * @return string
 158          */
 159         public static function sanitizeIP( $ip ) {
 160                 $ip = trim( $ip );
 161                 if ( $ip === '' ) {
 162                         return null;
 163                 }
 164                 if ( self::isIPv4( $ip ) || !self::isIPv6( $ip ) ) {
 165                         return $ip; // nothing else to do for IPv4 addresses or invalid ones
 166                 }
 167                 // Remove any whitespaces, convert to upper case
 168                 $ip = strtoupper( $ip );
 169                 // Expand zero abbreviations
 170                 $abbrevPos = strpos( $ip, '::' );
 171                 if ( $abbrevPos !== false ) {
 172                         // We know this is valid IPv6. Find the last index of the
 173                         // address before any CIDR number (e.g. "a:b:c::/24").
 174                         $CIDRStart = strpos( $ip, "/" );
 175                         $addressEnd = ( $CIDRStart !== false )
 176                                 ? $CIDRStart - 1
 177                                 : strlen( $ip ) - 1;
 178                         // If the '::' is at the beginning...
 179                         if ( $abbrevPos == 0 ) {
 180                                 $repeat = '0:';
 181                                 $extra = ( $ip == '::' ) ? '0' : ''; // for the address '::'
 182                                 $pad = 9; // 7+2 (due to '::')
 183                         // If the '::' is at the end...
 184                         } elseif ( $abbrevPos == ( $addressEnd - 1 ) ) {
 185                                 $repeat = ':0';
 186                                 $extra = '';
 187                                 $pad = 9; // 7+2 (due to '::')
 188                         // If the '::' is in the middle...
 189                         } else {
 190                                 $repeat = ':0';
 191                                 $extra = ':';
 192                                 $pad = 8; // 6+2 (due to '::')
 193                         }
 194                         $ip = str_replace( '::',
 195                                 str_repeat( $repeat, $pad - substr_count( $ip, ':' ) ) . $extra,
 196                                 $ip
 197                         );
 198                 }
 199                 // Remove leading zereos from each bloc as needed
 200                 $ip = preg_replace( '/(^|:)0+' . RE_IPV6_WORD . '/', '$1$2', $ip );
 201                 return $ip;
 202         }
 203
 204         /**
 205          * Given an unsigned integer, returns an IPv6 address in octet notation
 206          * @param string $ip_int IP address.
 207          * @return string
 208          */
 209         public static function toOctet( $ip_int ) {
 210                 return self::hexToOctet( wfBaseConvert( $ip_int, 10, 16, 32, false ) );
 211         }
 212
 213         /**
 214          * Convert an IPv4 or IPv6 hexadecimal representation back to readable format
 215          * @param string $hex number, with "v6-" prefix if it is IPv6
 216          * @return string quad-dotted (IPv4) or octet notation (IPv6)
 217          */
 218         public static function formatHex( $hex ) {
 219                 if ( substr( $hex, 0, 3 ) == 'v6-' ) { // IPv6
 220                         return self::hexToOctet( substr( $hex, 3 ) );
 221                 } else { // IPv4
 222                         return self::hexToQuad( $hex );
 223                 }
 224         }
 225
 226         /**
 227          * Converts a hexadecimal number to an IPv6 address in octet notation
 228          * @param string $ip_hex pure hex (no v6- prefix)
 229          * @return string (of format a:b:c:d:e:f:g:h)
 230          */
 231         public static function hexToOctet( $ip_hex ) {
 232                 // Pad hex to 32 chars (128 bits)
 233                 $ip_hex = str_pad( strtoupper( $ip_hex ), 32, '0', STR_PAD_LEFT );
 234                 // Separate into 8 words
 235                 $ip_oct = substr( $ip_hex, 0, 4 );
 236                 for ( $n = 1; $n < 8; $n++ ) {
 237                         $ip_oct .= ':' . substr( $ip_hex, 4 * $n, 4 );
 238                 }
 239                 // NO leading zeroes
 240                 $ip_oct = preg_replace( '/(^|:)0+' . RE_IPV6_WORD . '/', '$1$2', $ip_oct );
 241                 return $ip_oct;
 242         }
 243
 244         /**
 245          * Converts a hexadecimal number to an IPv4 address in quad-dotted notation
 246          * @param string $ip_hex pure hex
 247          * @return string (of format a.b.c.d)
 248          */
 249         public static function hexToQuad( $ip_hex ) {
 250                 // Pad hex to 8 chars (32 bits)
 251                 $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
 252                 // Separate into four quads
 253                 $s = '';
 254                 for ( $i = 0; $i < 4; $i++ ) {
 255                         if ( $s !== '' ) {
 256                                 $s .= '.';
 257                         }
 258                         $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
 259                 }
 260                 return $s;
 261         }
 262
 263         /**
 264          * Determine if an IP address really is an IP address, and if it is public,
 265          * i.e. not RFC 1918 or similar
 266          * Comes from ProxyTools.php
 267          * @param string $ip
 268          * @return bool
 269          */
 270         public static function isPublic( $ip ) {
 271                 if ( self::isIPv6( $ip ) ) {
 272                         return self::isPublic6( $ip );
 273                 }
 274                 $n = self::toUnsigned( $ip );
 275                 if ( !$n ) {
 276                         return false;
 277                 }
 278
 279                 // ip2long accepts incomplete addresses, as well as some addresses
 280                 // followed by garbage characters. Check that it's really valid.
 281                 if ( $ip != long2ip( $n ) ) {
 282                         return false;
 283                 }
 284
 285                 static $privateRanges = false;
 286                 if ( !$privateRanges ) {
 287                         $privateRanges = array(
 288                                 array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 289                                 array( '172.16.0.0',  '172.31.255.255' ),   #     "
 290                                 array( '192.168.0.0', '192.168.255.255' ),  #     "
 291                                 array( '0.0.0.0',     '0.255.255.255' ),    # this network
 292                                 array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 293                         );
 294                 }
 295
 296                 foreach ( $privateRanges as $r ) {
 297                         $start = self::toUnsigned( $r[0] );
 298                         $end = self::toUnsigned( $r[1] );
 299                         if ( $n >= $start && $n <= $end ) {
 300                                 return false;
 301                         }
 302                 }
 303                 return true;
 304         }
 305
 306         /**
 307          * Determine if an IPv6 address really is an IP address, and if it is public,
 308          * i.e. not RFC 4193 or similar
 309          * @param string $ip
 310          * @return bool
 311          */
 312         private static function isPublic6( $ip ) {
 313                 static $privateRanges = false;
 314                 if ( !$privateRanges ) {
 315                         $privateRanges = array(
 316                                 array( 'fc::', 'fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff' ), # RFC 4193 (local)
 317                                 array( '0:0:0:0:0:0:0:1', '0:0:0:0:0:0:0:1' ), # loopback
 318                         );
 319                 }
 320                 $n = self::toHex( $ip );
 321                 foreach ( $privateRanges as $r ) {
 322                         $start = self::toHex( $r[0] );
 323                         $end = self::toHex( $r[1] );
 324                         if ( $n >= $start && $n <= $end ) {
 325                                 return false;
 326                         }
 327                 }
 328                 return true;
 329         }
 330
 331         /**
 332          * Return a zero-padded upper case hexadecimal representation of an IP address.
 333          *
 334          * Hexadecimal addresses are used because they can easily be extended to
 335          * IPv6 support. To separate the ranges, the return value from this
 336          * function for an IPv6 address will be prefixed with "v6-", a non-
 337          * hexadecimal string which sorts after the IPv4 addresses.
 338          *
 339          * @param string $ip Quad dotted/octet IP address.
 340          * @return string
 341          */
 342         public static function toHex( $ip ) {
 343                 if ( self::isIPv6( $ip ) ) {
 344                         $n = 'v6-' . self::IPv6ToRawHex( $ip );
 345                 } else {
 346                         $n = self::toUnsigned( $ip );
 347                         if ( $n !== false ) {
 348                                 $n = wfBaseConvert( $n, 10, 16, 8, false );
 349                         }
 350                 }
 351                 return $n;
 352         }
 353
 354         /**
 355          * Given an IPv6 address in octet notation, returns a pure hex string.
 356          * @param string $ip octet ipv6 IP address.
 357          * @return string pure hex (uppercase)
 358          */
 359         private static function IPv6ToRawHex( $ip ) {
 360                 $ip = self::sanitizeIP( $ip );
 361                 if ( !$ip ) {
 362                         return null;
 363                 }
 364                 $r_ip = '';
 365                 foreach ( explode( ':', $ip ) as $v ) {
 366                         $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
 367                 }
 368                 return $r_ip;
 369         }
 370
 371         /**
 372          * Given an IP address in dotted-quad/octet notation, returns an unsigned integer.
 373          * Like ip2long() except that it actually works and has a consistent error return value.
 374          * Comes from ProxyTools.php
 375          * @param string $ip Quad dotted IP address.
 376          * @return mixed (string/int/false)
 377          */
 378         public static function toUnsigned( $ip ) {
 379                 if ( self::isIPv6( $ip ) ) {
 380                         $n = self::toUnsigned6( $ip );
 381                 } else {
 382                         $n = ip2long( $ip );
 383                         if ( $n < 0 ) {
 384                                 $n += pow( 2, 32 );
 385                         }
 386                 }
 387                 return $n;
 388         }
 389
 390         private static function toUnsigned6( $ip ) {
 391                 return wfBaseConvert( self::IPv6ToRawHex( $ip ), 16, 10 );
 392         }
 393
 394         /**
 395          * Convert a network specification in CIDR notation
 396          * to an integer network and a number of bits
 397          * @param string $range IP with CIDR prefix
 398          * @return array(int or string, int)
 399          */
 400         public static function parseCIDR( $range ) {
 401                 if ( self::isIPv6( $range ) ) {
 402                         return self::parseCIDR6( $range );
 403                 }
 404                 $parts = explode( '/', $range, 2 );
 405                 if ( count( $parts ) != 2 ) {
 406                         return array( false, false );
 407                 }
 408                 list( $network, $bits ) = $parts;
 409                 $network = ip2long( $network );
 410                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 411                         if ( $bits == 0 ) {
 412                                 $network = 0;
 413                         } else {
 414                                 $network &= ~( ( 1 << ( 32 - $bits ) ) - 1);
 415                         }
 416                         # Convert to unsigned
 417                         if ( $network < 0 ) {
 418                                 $network += pow( 2, 32 );
 419                         }
 420                 } else {
 421                         $network = false;
 422                         $bits = false;
 423                 }
 424                 return array( $network, $bits );
 425         }
 426
 427         /**
 428          * Given a string range in a number of formats,
 429          * return the start and end of the range in hexadecimal.
 430          *
 431          * Formats are:
 432          *     1.2.3.4/24          CIDR
 433          *     1.2.3.4 - 1.2.3.5   Explicit range
 434          *     1.2.3.4             Single IP
 435          *
 436          *     2001:0db8:85a3::7344/96                                   CIDR
 437          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 438          *     2001:0db8:85a3::7344                                      Single IP
 439          * @param string $range IP range
 440          * @return array(string, string)
 441          */
 442         public static function parseRange( $range ) {
 443                 // CIDR notation
 444                 if ( strpos( $range, '/' ) !== false ) {
 445                         if ( self::isIPv6( $range ) ) {
 446                                 return self::parseRange6( $range );
 447                         }
 448                         list( $network, $bits ) = self::parseCIDR( $range );
 449                         if ( $network === false ) {
 450                                 $start = $end = false;
 451                         } else {
 452                                 $start = sprintf( '%08X', $network );
 453                                 $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
 454                         }
 455                 // Explicit range
 456                 } elseif ( strpos( $range, '-' ) !== false ) {
 457                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 458                         if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
 459                                 return self::parseRange6( $range );
 460                         }
 461                         if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
 462                                 $start = self::toUnsigned( $start );
 463                                 $end = self::toUnsigned( $end );
 464                                 if ( $start > $end ) {
 465                                         $start = $end = false;
 466                                 } else {
 467                                         $start = sprintf( '%08X', $start );
 468                                         $end = sprintf( '%08X', $end );
 469                                 }
 470                         } else {
 471                                 $start = $end = false;
 472                         }
 473                 } else {
 474                         # Single IP
 475                         $start = $end = self::toHex( $range );
 476                 }
 477                 if ( $start === false || $end === false ) {
 478                         return array( false, false );
 479                 } else {
 480                         return array( $start, $end );
 481                 }
 482         }
 483
 484         /**
 485          * Convert a network specification in IPv6 CIDR notation to an
 486          * integer network and a number of bits
 487          * @return array(string, int)
 488          */
 489         private static function parseCIDR6( $range ) {
 490                 # Explode into <expanded IP,range>
 491                 $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
 492                 if ( count( $parts ) != 2 ) {
 493                         return array( false, false );
 494                 }
 495                 list( $network, $bits ) = $parts;
 496                 $network = self::IPv6ToRawHex( $network );
 497                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
 498                         if ( $bits == 0 ) {
 499                                 $network = "0";
 500                         } else {
 501                                 # Native 32 bit functions WONT work here!!!
 502                                 # Convert to a padded binary number
 503                                 $network = wfBaseConvert( $network, 16, 2, 128 );
 504                                 # Truncate the last (128-$bits) bits and replace them with zeros
 505                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 506                                 # Convert back to an integer
 507                                 $network = wfBaseConvert( $network, 2, 10 );
 508                         }
 509                 } else {
 510                         $network = false;
 511                         $bits = false;
 512                 }
 513                 return array( $network, (int)$bits );
 514         }
 515
 516         /**
 517          * Given a string range in a number of formats, return the
 518          * start and end of the range in hexadecimal. For IPv6.
 519          *
 520          * Formats are:
 521          *     2001:0db8:85a3::7344/96                                   CIDR
 522          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 523          *     2001:0db8:85a3::7344/96                                   Single IP
 524          * @return array(string, string)
 525          */
 526         private static function parseRange6( $range ) {
 527                 # Expand any IPv6 IP
 528                 $range = IP::sanitizeIP( $range );
 529                 // CIDR notation...
 530                 if ( strpos( $range, '/' ) !== false ) {
 531                         list( $network, $bits ) = self::parseCIDR6( $range );
 532                         if ( $network === false ) {
 533                                 $start = $end = false;
 534                         } else {
 535                                 $start = wfBaseConvert( $network, 10, 16, 32, false );
 536                                 # Turn network to binary (again)
 537                                 $end = wfBaseConvert( $network, 10, 2, 128 );
 538                                 # Truncate the last (128-$bits) bits and replace them with ones
 539                                 $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
 540                                 # Convert to hex
 541                                 $end = wfBaseConvert( $end, 2, 16, 32, false );
 542                                 # see toHex() comment
 543                                 $start = "v6-$start";
 544                                 $end = "v6-$end";
 545                         }
 546                 // Explicit range notation...
 547                 } elseif ( strpos( $range, '-' ) !== false ) {
 548                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 549                         $start = self::toUnsigned6( $start );
 550                         $end = self::toUnsigned6( $end );
 551                         if ( $start > $end ) {
 552                                 $start = $end = false;
 553                         } else {
 554                                 $start = wfBaseConvert( $start, 10, 16, 32, false );
 555                                 $end = wfBaseConvert( $end, 10, 16, 32, false );
 556                         }
 557                         # see toHex() comment
 558                         $start = "v6-$start";
 559                         $end = "v6-$end";
 560                 } else {
 561                         # Single IP
 562                         $start = $end = self::toHex( $range );
 563                 }
 564                 if ( $start === false || $end === false ) {
 565                         return array( false, false );
 566                 } else {
 567                         return array( $start, $end );
 568                 }
 569         }
 570
 571         /**
 572          * Determine if a given IPv4/IPv6 address is in a given CIDR network
 573          * @param $addr The address to check against the given range.
 574          * @param $range The range to check the given address against.
 575          * @return bool Whether or not the given address is in the given range.
 576          */
 577         public static function isInRange( $addr, $range ) {
 578                 $hexIP = self::toHex( $addr );
 579                 list( $start, $end ) = self::parseRange( $range );
 580                 return ( strcmp( $hexIP, $start ) >= 0 &&
 581                         strcmp( $hexIP, $end ) <= 0 );
 582         }
 583
 584         /**
 585          * Convert some unusual representations of IPv4 addresses to their
 586          * canonical dotted quad representation.
 587          *
 588          * This currently only checks a few IPV4-to-IPv6 related cases.  More
 589          * unusual representations may be added later.
 590          *
 591          * @param $addr something that might be an IP address
 592          * @return valid dotted quad IPv4 address or null
 593          */
 594         public static function canonicalize( $addr ) {
 595                 if ( self::isValid( $addr ) ) {
 596                         return $addr;
 597                 }
 598                 // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
 599                 if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
 600                         $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
 601                         if ( self::isIPv4( $addr ) ) {
 602                                 return $addr;
 603                         }
 604                 }
 605                 // IPv6 loopback address
 606                 $m = array();
 607                 if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) ) {
 608                         return '127.0.0.1';
 609                 }
 610                 // IPv4-mapped and IPv4-compatible IPv6 addresses
 611                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) ) {
 612                         return $m[1];
 613                 }
 614                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD .
 615                         ':' . RE_IPV6_WORD . '$/i', $addr, $m ) )
 616                 {
 617                         return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 618                 }
 619
 620                 return null;  // give up
 621         }
 622 }