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 Antoine Musso "<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 "::" (including "::")
  39                 ':(?::|(?::' . RE_IPV6_WORD . '){1,7})' .
  40         '|' . // ends with "::" (except "::")
  41                 RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,6}::' .
  42         '|' . // contains one "::" in the middle, ending in "::WORD"
  43                 RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,5}' . '::' . RE_IPV6_WORD .
  44         '|' . // contains one "::" in the middle, not ending in "::WORD" (regex for PCRE 4.0+)
  45                 RE_IPV6_WORD . '(?::(?P<abn>:(?P<iabn>))?' . RE_IPV6_WORD . '(?!:(?P=abn))){1,5}' .
  46                         ':' . RE_IPV6_WORD . '(?P=iabn)' .
  47                 // NOTE: (?!(?P=abn)) fails iff "::" used twice; (?P=iabn) passes iff a "::" was found.
  48         '|' . // contains no "::"
  49                 RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){7}' .
  50         ')'
  51         // NOTE: With PCRE 7.2+, we can combine the two '"::" in the middle' cases into:
  52         //              RE_IPV6_WORD . '(?::((?(-1)|:))?' . RE_IPV6_WORD . '){1,6}(?(-2)|^)'
  53         // This also improves regex concatenation by using relative references.
  54 );
  55 // An IPv6 block is an IP address and a prefix (d1 to d128)
  56 define( 'RE_IPV6_BLOCK', RE_IPV6_ADD . '\/' . RE_IPV6_PREFIX );
  57 // For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
  58 define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
  59 define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );
  60
  61 // This might be useful for regexps used elsewhere, matches any IPv6 or IPv6 address or network
  62 define( 'IP_ADDRESS_STRING',
  63         '(?:' .
  64                 RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?' . // IPv4
  65         '|' .
  66                 RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?' . // IPv6
  67         ')'
  68 );
  69
  70 /**
  71  * A collection of public static functions to play with IP address
  72  * and IP blocks.
  73  */
  74 class IP {
  75         /**
  76          * Determine if a string is as valid IP address or network (CIDR prefix).
  77          * SIIT IPv4-translated addresses are rejected.
  78          * Note: canonicalize() tries to convert translated addresses to IPv4.
  79          *
  80          * @param $ip String: possible IP address
  81          * @return Boolean
  82          */
  83         public static function isIPAddress( $ip ) {
  84                 return (bool)preg_match( '/^' . IP_ADDRESS_STRING . '$/', $ip );
  85         }
  86
  87         /**
  88          * Given a string, determine if it as valid IP in IPv6 only.
  89          * Note: Unlike isValid(), this looks for networks too.
  90          *
  91          * @param $ip String: possible IP address
  92          * @return Boolean
  93          */
  94         public static function isIPv6( $ip ) {
  95                 return (bool)preg_match( '/^' . RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?$/', $ip );
  96         }
  97
  98         /**
  99          * Given a string, determine if it as valid IP in IPv4 only.
 100          * Note: Unlike isValid(), this looks for networks too.
 101          *
 102          * @param $ip String: possible IP address
 103          * @return Boolean
 104          */
 105         public static function isIPv4( $ip ) {
 106                 return (bool)preg_match( '/^' . RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?$/', $ip );
 107         }
 108
 109         /**
 110          * Validate an IP address. Ranges are NOT considered valid.
 111          * SIIT IPv4-translated addresses are rejected.
 112          * Note: canonicalize() tries to convert translated addresses to IPv4.
 113          *
 114          * @param $ip String
 115          * @return Boolean: True if it is valid.
 116          */
 117         public static function isValid( $ip ) {
 118                 return ( preg_match( '/^' . RE_IP_ADD . '$/', $ip )
 119                         || preg_match( '/^' . RE_IPV6_ADD . '$/', $ip ) );
 120         }
 121
 122         /**
 123          * Validate an IP Block (valid address WITH a valid prefix).
 124          * SIIT IPv4-translated addresses are rejected.
 125          * Note: canonicalize() tries to convert translated addresses to IPv4.
 126          *
 127          * @param $ipblock String
 128          * @return Boolean: True if it is valid.
 129          */
 130         public static function isValidBlock( $ipblock ) {
 131                 return ( preg_match( '/^' . RE_IPV6_BLOCK . '$/', $ipblock )
 132                         || preg_match( '/^' . RE_IP_BLOCK . '$/', $ipblock ) );
 133         }
 134
 135         /**
 136          * Convert an IP into a verbose, uppercase, normalized form.
 137          * IPv6 addresses in octet notation are expanded to 8 words.
 138          * IPv4 addresses are just trimmed.
 139          *
 140          * @param $ip String: IP address in quad or octet form (CIDR or not).
 141          * @return String
 142          */
 143         public static function sanitizeIP( $ip ) {
 144                 $ip = trim( $ip );
 145                 if ( $ip === '' ) {
 146                         return null;
 147                 }
 148                 if ( self::isIPv4( $ip ) || !self::isIPv6( $ip ) ) {
 149                         return $ip; // nothing else to do for IPv4 addresses or invalid ones
 150                 }
 151                 // Remove any whitespaces, convert to upper case
 152                 $ip = strtoupper( $ip );
 153                 // Expand zero abbreviations
 154                 $abbrevPos = strpos( $ip, '::' );
 155                 if ( $abbrevPos !== false ) {
 156                         // We know this is valid IPv6. Find the last index of the
 157                         // address before any CIDR number (e.g. "a:b:c::/24").
 158                         $CIDRStart = strpos( $ip, "/" );
 159                         $addressEnd = ( $CIDRStart !== false )
 160                                 ? $CIDRStart - 1
 161                                 : strlen( $ip ) - 1;
 162                         // If the '::' is at the beginning...
 163                         if ( $abbrevPos == 0 ) {
 164                                 $repeat = '0:';
 165                                 $extra = ( $ip == '::' ) ? '0' : ''; // for the address '::'
 166                                 $pad = 9; // 7+2 (due to '::')
 167                         // If the '::' is at the end...
 168                         } elseif ( $abbrevPos == ( $addressEnd - 1 ) ) {
 169                                 $repeat = ':0';
 170                                 $extra = '';
 171                                 $pad = 9; // 7+2 (due to '::')
 172                         // If the '::' is in the middle...
 173                         } else {
 174                                 $repeat = ':0';
 175                                 $extra = ':';
 176                                 $pad = 8; // 6+2 (due to '::')
 177                         }
 178                         $ip = str_replace( '::',
 179                                 str_repeat( $repeat, $pad - substr_count( $ip, ':' ) ) . $extra,
 180                                 $ip
 181                         );
 182                 }
 183                 // Remove leading zereos from each bloc as needed
 184                 $ip = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip );
 185                 return $ip;
 186         }
 187
 188         /**
 189          * Prettify an IP for display to end users.
 190          * This will make it more compact and lower-case.
 191          *
 192          * @param $ip string
 193          * @return string
 194          */
 195         public static function prettifyIP( $ip ) {
 196                 $ip = self::sanitizeIP( $ip ); // normalize (removes '::')
 197                 if ( self::isIPv6( $ip ) ) {
 198                         // Split IP into an address and a CIDR
 199                         if ( strpos( $ip, '/' ) !== false ) {
 200                                 list( $ip, $cidr ) = explode( '/', $ip, 2 );
 201                         } else {
 202                                 list( $ip, $cidr ) = array( $ip, '' );
 203                         }
 204                         // Get the largest slice of words with multiple zeros
 205                         $offset = 0;
 206                         $longest = $longestPos = false;
 207                         while ( preg_match(
 208                                 '!(?:^|:)0(?::0)+(?:$|:)!', $ip, $m, PREG_OFFSET_CAPTURE, $offset
 209                         ) ) {
 210                                 list( $match, $pos ) = $m[0]; // full match
 211                                 if ( strlen( $match ) > strlen( $longest ) ) {
 212                                         $longest = $match;
 213                                         $longestPos = $pos;
 214                                 }
 215                                 $offset += ( $pos + strlen( $match ) ); // advance
 216                         }
 217                         if ( $longest !== false ) {
 218                                 // Replace this portion of the string with the '::' abbreviation
 219                                 $ip = substr_replace( $ip, '::', $longestPos, strlen( $longest ) );
 220                         }
 221                         // Add any CIDR back on
 222                         if ( $cidr !== '' ) {
 223                                 $ip = "{$ip}/{$cidr}";
 224                         }
 225                         // Convert to lower case to make it more readable
 226                         $ip = strtolower( $ip );
 227                 }
 228                 return $ip;
 229         }
 230
 231         /**
 232          * Given a host/port string, like one might find in the host part of a URL
 233          * per RFC 2732, split the hostname part and the port part and return an
 234          * array with an element for each. If there is no port part, the array will
 235          * have false in place of the port. If the string was invalid in some way,
 236          * false is returned.
 237          *
 238          * This was easy with IPv4 and was generally done in an ad-hoc way, but
 239          * with IPv6 it's somewhat more complicated due to the need to parse the
 240          * square brackets and colons.
 241          *
 242          * A bare IPv6 address is accepted despite the lack of square brackets.
 243          *
 244          * @param $both string The string with the host and port
 245          * @return array
 246          */
 247         public static function splitHostAndPort( $both ) {
 248                 if ( substr( $both, 0, 1 ) === '[' ) {
 249                         if ( preg_match( '/^\[(' . RE_IPV6_ADD . ')\](?::(?P<port>\d+))?$/', $both, $m ) ) {
 250                                 if ( isset( $m['port'] ) ) {
 251                                         return array( $m[1], intval( $m['port'] ) );
 252                                 } else {
 253                                         return array( $m[1], false );
 254                                 }
 255                         } else {
 256                                 // Square bracket found but no IPv6
 257                                 return false;
 258                         }
 259                 }
 260                 $numColons = substr_count( $both, ':' );
 261                 if ( $numColons >= 2 ) {
 262                         // Is it a bare IPv6 address?
 263                         if ( preg_match( '/^' . RE_IPV6_ADD . '$/', $both ) ) {
 264                                 return array( $both, false );
 265                         } else {
 266                                 // Not valid IPv6, but too many colons for anything else
 267                                 return false;
 268                         }
 269                 }
 270                 if ( $numColons >= 1 ) {
 271                         // Host:port?
 272                         $bits = explode( ':', $both );
 273                         if ( preg_match( '/^\d+/', $bits[1] ) ) {
 274                                 return array( $bits[0], intval( $bits[1] ) );
 275                         } else {
 276                                 // Not a valid port
 277                                 return false;
 278                         }
 279                 }
 280                 // Plain hostname
 281                 return array( $both, false );
 282         }
 283
 284         /**
 285          * Given a host name and a port, combine them into host/port string like
 286          * you might find in a URL. If the host contains a colon, wrap it in square
 287          * brackets like in RFC 2732. If the port matches the default port, omit
 288          * the port specification
 289          *
 290          * @param $host string
 291          * @param $port int
 292          * @param $defaultPort bool|int
 293          * @return string
 294          */
 295         public static function combineHostAndPort( $host, $port, $defaultPort = false ) {
 296                 if ( strpos( $host, ':' ) !== false ) {
 297                         $host = "[$host]";
 298                 }
 299                 if ( $defaultPort !== false && $port == $defaultPort ) {
 300                         return $host;
 301                 } else {
 302                         return "$host:$port";
 303                 }
 304         }
 305
 306         /**
 307          * Given an unsigned integer, returns an IPv6 address in octet notation
 308          *
 309          * @param $ip_int String: IP address.
 310          * @return String
 311          */
 312         public static function toOctet( $ip_int ) {
 313                 return self::hexToOctet( wfBaseConvert( $ip_int, 10, 16, 32, false ) );
 314         }
 315
 316         /**
 317          * Convert an IPv4 or IPv6 hexadecimal representation back to readable format
 318          *
 319          * @param $hex String: number, with "v6-" prefix if it is IPv6
 320          * @return String: quad-dotted (IPv4) or octet notation (IPv6)
 321          */
 322         public static function formatHex( $hex ) {
 323                 if ( substr( $hex, 0, 3 ) == 'v6-' ) { // IPv6
 324                         return self::hexToOctet( substr( $hex, 3 ) );
 325                 } else { // IPv4
 326                         return self::hexToQuad( $hex );
 327                 }
 328         }
 329
 330         /**
 331          * Converts a hexadecimal number to an IPv6 address in octet notation
 332          *
 333          * @param $ip_hex String: pure hex (no v6- prefix)
 334          * @return String (of format a:b:c:d:e:f:g:h)
 335          */
 336         public static function hexToOctet( $ip_hex ) {
 337                 // Pad hex to 32 chars (128 bits)
 338                 $ip_hex = str_pad( strtoupper( $ip_hex ), 32, '0', STR_PAD_LEFT );
 339                 // Separate into 8 words
 340                 $ip_oct = substr( $ip_hex, 0, 4 );
 341                 for ( $n = 1; $n < 8; $n++ ) {
 342                         $ip_oct .= ':' . substr( $ip_hex, 4 * $n, 4 );
 343                 }
 344                 // NO leading zeroes
 345                 $ip_oct = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip_oct );
 346                 return $ip_oct;
 347         }
 348
 349         /**
 350          * Converts a hexadecimal number to an IPv4 address in quad-dotted notation
 351          *
 352          * @param $ip_hex String: pure hex
 353          * @return String (of format a.b.c.d)
 354          */
 355         public static function hexToQuad( $ip_hex ) {
 356                 // Pad hex to 8 chars (32 bits)
 357                 $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
 358                 // Separate into four quads
 359                 $s = '';
 360                 for ( $i = 0; $i < 4; $i++ ) {
 361                         if ( $s !== '' ) {
 362                                 $s .= '.';
 363                         }
 364                         $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
 365                 }
 366                 return $s;
 367         }
 368
 369         /**
 370          * Determine if an IP address really is an IP address, and if it is public,
 371          * i.e. not RFC 1918 or similar
 372          * Comes from ProxyTools.php
 373          *
 374          * @param $ip String
 375          * @return Boolean
 376          */
 377         public static function isPublic( $ip ) {
 378                 if ( self::isIPv6( $ip ) ) {
 379                         return self::isPublic6( $ip );
 380                 }
 381                 $n = self::toUnsigned( $ip );
 382                 if ( !$n ) {
 383                         return false;
 384                 }
 385
 386                 // ip2long accepts incomplete addresses, as well as some addresses
 387                 // followed by garbage characters. Check that it's really valid.
 388                 if ( $ip != long2ip( $n ) ) {
 389                         return false;
 390                 }
 391
 392                 static $privateRanges = false;
 393                 if ( !$privateRanges ) {
 394                         $privateRanges = array(
 395                                 array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 396                                 array( '172.16.0.0',  '172.31.255.255' ),   #     "
 397                                 array( '192.168.0.0', '192.168.255.255' ),  #     "
 398                                 array( '0.0.0.0',     '0.255.255.255' ),    # this network
 399                                 array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 400                         );
 401                 }
 402
 403                 foreach ( $privateRanges as $r ) {
 404                         $start = self::toUnsigned( $r[0] );
 405                         $end = self::toUnsigned( $r[1] );
 406                         if ( $n >= $start && $n <= $end ) {
 407                                 return false;
 408                         }
 409                 }
 410                 return true;
 411         }
 412
 413         /**
 414          * Determine if an IPv6 address really is an IP address, and if it is public,
 415          * i.e. not RFC 4193 or similar
 416          *
 417          * @param $ip String
 418          * @return Boolean
 419          */
 420         private static function isPublic6( $ip ) {
 421                 static $privateRanges = false;
 422                 if ( !$privateRanges ) {
 423                         $privateRanges = array(
 424                                 array( 'fc00::', 'fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff' ), # RFC 4193 (local)
 425                                 array( '0:0:0:0:0:0:0:1', '0:0:0:0:0:0:0:1' ), # loopback
 426                         );
 427                 }
 428                 $n = self::toHex( $ip );
 429                 foreach ( $privateRanges as $r ) {
 430                         $start = self::toHex( $r[0] );
 431                         $end = self::toHex( $r[1] );
 432                         if ( $n >= $start && $n <= $end ) {
 433                                 return false;
 434                         }
 435                 }
 436                 return true;
 437         }
 438
 439         /**
 440          * Return a zero-padded upper case hexadecimal representation of an IP address.
 441          *
 442          * Hexadecimal addresses are used because they can easily be extended to
 443          * IPv6 support. To separate the ranges, the return value from this
 444          * function for an IPv6 address will be prefixed with "v6-", a non-
 445          * hexadecimal string which sorts after the IPv4 addresses.
 446          *
 447          * @param $ip String: quad dotted/octet IP address.
 448          * @return String
 449          */
 450         public static function toHex( $ip ) {
 451                 if ( self::isIPv6( $ip ) ) {
 452                         $n = 'v6-' . self::IPv6ToRawHex( $ip );
 453                 } else {
 454                         $n = self::toUnsigned( $ip );
 455                         if ( $n !== false ) {
 456                                 $n = wfBaseConvert( $n, 10, 16, 8, false );
 457                         }
 458                 }
 459                 return $n;
 460         }
 461
 462         /**
 463          * Given an IPv6 address in octet notation, returns a pure hex string.
 464          *
 465          * @param $ip String: octet ipv6 IP address.
 466          * @return String: pure hex (uppercase)
 467          */
 468         private static function IPv6ToRawHex( $ip ) {
 469                 $ip = self::sanitizeIP( $ip );
 470                 if ( !$ip ) {
 471                         return null;
 472                 }
 473                 $r_ip = '';
 474                 foreach ( explode( ':', $ip ) as $v ) {
 475                         $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
 476                 }
 477                 return $r_ip;
 478         }
 479
 480         /**
 481          * Given an IP address in dotted-quad/octet notation, returns an unsigned integer.
 482          * Like ip2long() except that it actually works and has a consistent error return value.
 483          * Comes from ProxyTools.php
 484          *
 485          * @param $ip String: quad dotted IP address.
 486          * @return Mixed: string/int/false
 487          */
 488         public static function toUnsigned( $ip ) {
 489                 if ( self::isIPv6( $ip ) ) {
 490                         $n = self::toUnsigned6( $ip );
 491                 } else {
 492                         $n = ip2long( $ip );
 493                         if ( $n < 0 ) {
 494                                 $n += pow( 2, 32 );
 495                         }
 496                 }
 497                 return $n;
 498         }
 499
 500         /**
 501          * @param $ip
 502          * @return String
 503          */
 504         private static function toUnsigned6( $ip ) {
 505                 return wfBaseConvert( self::IPv6ToRawHex( $ip ), 16, 10 );
 506         }
 507
 508         /**
 509          * Convert a network specification in CIDR notation
 510          * to an integer network and a number of bits
 511          *
 512          * @param $range String: IP with CIDR prefix
 513          * @return array(int or string, int)
 514          */
 515         public static function parseCIDR( $range ) {
 516                 if ( self::isIPv6( $range ) ) {
 517                         return self::parseCIDR6( $range );
 518                 }
 519                 $parts = explode( '/', $range, 2 );
 520                 if ( count( $parts ) != 2 ) {
 521                         return array( false, false );
 522                 }
 523                 list( $network, $bits ) = $parts;
 524                 $network = ip2long( $network );
 525                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 526                         if ( $bits == 0 ) {
 527                                 $network = 0;
 528                         } else {
 529                                 $network &= ~( ( 1 << ( 32 - $bits ) ) - 1);
 530                         }
 531                         # Convert to unsigned
 532                         if ( $network < 0 ) {
 533                                 $network += pow( 2, 32 );
 534                         }
 535                 } else {
 536                         $network = false;
 537                         $bits = false;
 538                 }
 539                 return array( $network, $bits );
 540         }
 541
 542         /**
 543          * Given a string range in a number of formats,
 544          * return the start and end of the range in hexadecimal.
 545          *
 546          * Formats are:
 547          *     1.2.3.4/24          CIDR
 548          *     1.2.3.4 - 1.2.3.5   Explicit range
 549          *     1.2.3.4             Single IP
 550          *
 551          *     2001:0db8:85a3::7344/96                                   CIDR
 552          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 553          *     2001:0db8:85a3::7344                                      Single IP
 554          * @param $range String: IP range
 555          * @return array(string, string)
 556          */
 557         public static function parseRange( $range ) {
 558                 // CIDR notation
 559                 if ( strpos( $range, '/' ) !== false ) {
 560                         if ( self::isIPv6( $range ) ) {
 561                                 return self::parseRange6( $range );
 562                         }
 563                         list( $network, $bits ) = self::parseCIDR( $range );
 564                         if ( $network === false ) {
 565                                 $start = $end = false;
 566                         } else {
 567                                 $start = sprintf( '%08X', $network );
 568                                 $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
 569                         }
 570                 // Explicit range
 571                 } elseif ( strpos( $range, '-' ) !== false ) {
 572                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 573                         if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
 574                                 return self::parseRange6( $range );
 575                         }
 576                         if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
 577                                 $start = self::toUnsigned( $start );
 578                                 $end = self::toUnsigned( $end );
 579                                 if ( $start > $end ) {
 580                                         $start = $end = false;
 581                                 } else {
 582                                         $start = sprintf( '%08X', $start );
 583                                         $end = sprintf( '%08X', $end );
 584                                 }
 585                         } else {
 586                                 $start = $end = false;
 587                         }
 588                 } else {
 589                         # Single IP
 590                         $start = $end = self::toHex( $range );
 591                 }
 592                 if ( $start === false || $end === false ) {
 593                         return array( false, false );
 594                 } else {
 595                         return array( $start, $end );
 596                 }
 597         }
 598
 599         /**
 600          * Convert a network specification in IPv6 CIDR notation to an
 601          * integer network and a number of bits
 602          *
 603          * @param $range
 604          *
 605          * @return array(string, int)
 606          */
 607         private static function parseCIDR6( $range ) {
 608                 # Explode into <expanded IP,range>
 609                 $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
 610                 if ( count( $parts ) != 2 ) {
 611                         return array( false, false );
 612                 }
 613                 list( $network, $bits ) = $parts;
 614                 $network = self::IPv6ToRawHex( $network );
 615                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
 616                         if ( $bits == 0 ) {
 617                                 $network = "0";
 618                         } else {
 619                                 # Native 32 bit functions WONT work here!!!
 620                                 # Convert to a padded binary number
 621                                 $network = wfBaseConvert( $network, 16, 2, 128 );
 622                                 # Truncate the last (128-$bits) bits and replace them with zeros
 623                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 624                                 # Convert back to an integer
 625                                 $network = wfBaseConvert( $network, 2, 10 );
 626                         }
 627                 } else {
 628                         $network = false;
 629                         $bits = false;
 630                 }
 631                 return array( $network, (int)$bits );
 632         }
 633
 634         /**
 635          * Given a string range in a number of formats, return the
 636          * start and end of the range in hexadecimal. For IPv6.
 637          *
 638          * Formats are:
 639          *     2001:0db8:85a3::7344/96                                   CIDR
 640          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 641          *     2001:0db8:85a3::7344/96                                   Single IP
 642          *
 643          * @param $range
 644          *
 645          * @return array(string, string)
 646          */
 647         private static function parseRange6( $range ) {
 648                 # Expand any IPv6 IP
 649                 $range = IP::sanitizeIP( $range );
 650                 // CIDR notation...
 651                 if ( strpos( $range, '/' ) !== false ) {
 652                         list( $network, $bits ) = self::parseCIDR6( $range );
 653                         if ( $network === false ) {
 654                                 $start = $end = false;
 655                         } else {
 656                                 $start = wfBaseConvert( $network, 10, 16, 32, false );
 657                                 # Turn network to binary (again)
 658                                 $end = wfBaseConvert( $network, 10, 2, 128 );
 659                                 # Truncate the last (128-$bits) bits and replace them with ones
 660                                 $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
 661                                 # Convert to hex
 662                                 $end = wfBaseConvert( $end, 2, 16, 32, false );
 663                                 # see toHex() comment
 664                                 $start = "v6-$start";
 665                                 $end = "v6-$end";
 666                         }
 667                 // Explicit range notation...
 668                 } elseif ( strpos( $range, '-' ) !== false ) {
 669                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 670                         $start = self::toUnsigned6( $start );
 671                         $end = self::toUnsigned6( $end );
 672                         if ( $start > $end ) {
 673                                 $start = $end = false;
 674                         } else {
 675                                 $start = wfBaseConvert( $start, 10, 16, 32, false );
 676                                 $end = wfBaseConvert( $end, 10, 16, 32, false );
 677                         }
 678                         # see toHex() comment
 679                         $start = "v6-$start";
 680                         $end = "v6-$end";
 681                 } else {
 682                         # Single IP
 683                         $start = $end = self::toHex( $range );
 684                 }
 685                 if ( $start === false || $end === false ) {
 686                         return array( false, false );
 687                 } else {
 688                         return array( $start, $end );
 689                 }
 690         }
 691
 692         /**
 693          * Determine if a given IPv4/IPv6 address is in a given CIDR network
 694          *
 695          * @param $addr String: the address to check against the given range.
 696          * @param $range String: the range to check the given address against.
 697          * @return Boolean: whether or not the given address is in the given range.
 698          */
 699         public static function isInRange( $addr, $range ) {
 700                 $hexIP = self::toHex( $addr );
 701                 list( $start, $end ) = self::parseRange( $range );
 702                 return ( strcmp( $hexIP, $start ) >= 0 &&
 703                         strcmp( $hexIP, $end ) <= 0 );
 704         }
 705
 706         /**
 707          * Convert some unusual representations of IPv4 addresses to their
 708          * canonical dotted quad representation.
 709          *
 710          * This currently only checks a few IPV4-to-IPv6 related cases.  More
 711          * unusual representations may be added later.
 712          *
 713          * @param $addr String: something that might be an IP address
 714          * @return String: valid dotted quad IPv4 address or null
 715          */
 716         public static function canonicalize( $addr ) {
 717                 $addr = preg_replace( '/\%.*/','', $addr ); // remove zone info (bug 35738)
 718                 if ( self::isValid( $addr ) ) {
 719                         return $addr;
 720                 }
 721                 // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
 722                 if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
 723                         $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
 724                         if ( self::isIPv4( $addr ) ) {
 725                                 return $addr;
 726                         }
 727                 }
 728                 // IPv6 loopback address
 729                 $m = array();
 730                 if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) ) {
 731                         return '127.0.0.1';
 732                 }
 733                 // IPv4-mapped and IPv4-compatible IPv6 addresses
 734                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) ) {
 735                         return $m[1];
 736                 }
 737                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD .
 738                         ':' . RE_IPV6_WORD . '$/i', $addr, $m ) )
 739                 {
 740                         return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 741                 }
 742
 743                 return null;  // give up
 744         }
 745
 746         /**
 747          * Gets rid of uneeded numbers in quad-dotted/octet IP strings
 748          * For example, 127.111.113.151/24 -> 127.111.113.0/24
 749          * @param $range String: IP address to normalize
 750          * @return string
 751          */
 752         public static function sanitizeRange( $range ) {
 753                 list( /*...*/, $bits ) = self::parseCIDR( $range );
 754                 list( $start, /*...*/ ) = self::parseRange( $range );
 755                 $start = self::formatHex( $start );
 756                 if ( $bits === false ) {
 757                         return $start; // wasn't actually a range
 758                 }
 759                 return "$start/$bits";
 760         }
 761 }