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