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 nice standard 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          * Given a host/port string, like one might find in the host part of a URL
 190          * per RFC 2732, split the hostname part and the port part and return an
 191          * array with an element for each. If there is no port part, the array will
 192          * have false in place of the port. If the string was invalid in some way,
 193          * false is returned.
 194          *
 195          * This was easy with IPv4 and was generally done in an ad-hoc way, but
 196          * with IPv6 it's somewhat more complicated due to the need to parse the
 197          * square brackets and colons.
 198          *
 199          * A bare IPv6 address is accepted despite the lack of square brackets.
 200          *
 201          * @param $both The string with the host and port
 202          * @return array
 203          */
 204         public static function splitHostAndPort( $both ) {
 205                 if ( substr( $both, 0, 1 ) === '[' ) {
 206                         if ( preg_match( '/^\[(' . RE_IPV6_ADD . ')\](?::(?P<port>\d+))?$/', $both, $m ) ) {
 207                                 if ( isset( $m['port'] ) ) {
 208                                         return array( $m[1], intval( $m['port'] ) );
 209                                 } else {
 210                                         return array( $m[1], false );
 211                                 }
 212                         } else {
 213                                 // Square bracket found but no IPv6
 214                                 return false;
 215                         }
 216                 }
 217                 $numColons = substr_count( $both, ':' );
 218                 if ( $numColons >= 2 ) {
 219                         // Is it a bare IPv6 address?
 220                         if ( preg_match( '/^' . RE_IPV6_ADD . '$/', $both ) ) {
 221                                 return array( $both, false );
 222                         } else {
 223                                 // Not valid IPv6, but too many colons for anything else
 224                                 return false;
 225                         }
 226                 }
 227                 if ( $numColons >= 1 ) {
 228                         // Host:port?
 229                         $bits = explode( ':', $both );
 230                         if ( preg_match( '/^\d+/', $bits[1] ) ) {
 231                                 return array( $bits[0], intval( $bits[1] ) );
 232                         } else {
 233                                 // Not a valid port
 234                                 return false;
 235                         }
 236                 }
 237                 // Plain hostname
 238                 return array( $both, false );
 239         }
 240
 241         /**
 242          * Given a host name and a port, combine them into host/port string like
 243          * you might find in a URL. If the host contains a colon, wrap it in square
 244          * brackets like in RFC 2732. If the port matches the default port, omit
 245          * the port specification
 246          *
 247          * @param $host string
 248          * @param $port int
 249          * @param $defaultPort bool|int
 250          * @return string
 251          */
 252         public static function combineHostAndPort( $host, $port, $defaultPort = false ) {
 253                 if ( strpos( $host, ':' ) !== false ) {
 254                         $host = "[$host]";
 255                 }
 256                 if ( $defaultPort !== false && $port == $defaultPort ) {
 257                         return $host;
 258                 } else {
 259                         return "$host:$port";
 260                 }
 261         }
 262
 263         /**
 264          * Given an unsigned integer, returns an IPv6 address in octet notation
 265          *
 266          * @param $ip_int String: IP address.
 267          * @return String
 268          */
 269         public static function toOctet( $ip_int ) {
 270                 return self::hexToOctet( wfBaseConvert( $ip_int, 10, 16, 32, false ) );
 271         }
 272
 273         /**
 274          * Convert an IPv4 or IPv6 hexadecimal representation back to readable format
 275          *
 276          * @param $hex String: number, with "v6-" prefix if it is IPv6
 277          * @return String: quad-dotted (IPv4) or octet notation (IPv6)
 278          */
 279         public static function formatHex( $hex ) {
 280                 if ( substr( $hex, 0, 3 ) == 'v6-' ) { // IPv6
 281                         return self::hexToOctet( substr( $hex, 3 ) );
 282                 } else { // IPv4
 283                         return self::hexToQuad( $hex );
 284                 }
 285         }
 286
 287         /**
 288          * Converts a hexadecimal number to an IPv6 address in octet notation
 289          *
 290          * @param $ip_hex String: pure hex (no v6- prefix)
 291          * @return String (of format a:b:c:d:e:f:g:h)
 292          */
 293         public static function hexToOctet( $ip_hex ) {
 294                 // Pad hex to 32 chars (128 bits)
 295                 $ip_hex = str_pad( strtoupper( $ip_hex ), 32, '0', STR_PAD_LEFT );
 296                 // Separate into 8 words
 297                 $ip_oct = substr( $ip_hex, 0, 4 );
 298                 for ( $n = 1; $n < 8; $n++ ) {
 299                         $ip_oct .= ':' . substr( $ip_hex, 4 * $n, 4 );
 300                 }
 301                 // NO leading zeroes
 302                 $ip_oct = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip_oct );
 303                 return $ip_oct;
 304         }
 305
 306         /**
 307          * Converts a hexadecimal number to an IPv4 address in quad-dotted notation
 308          *
 309          * @param $ip_hex String: pure hex
 310          * @return String (of format a.b.c.d)
 311          */
 312         public static function hexToQuad( $ip_hex ) {
 313                 // Pad hex to 8 chars (32 bits)
 314                 $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
 315                 // Separate into four quads
 316                 $s = '';
 317                 for ( $i = 0; $i < 4; $i++ ) {
 318                         if ( $s !== '' ) {
 319                                 $s .= '.';
 320                         }
 321                         $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
 322                 }
 323                 return $s;
 324         }
 325
 326         /**
 327          * Determine if an IP address really is an IP address, and if it is public,
 328          * i.e. not RFC 1918 or similar
 329          * Comes from ProxyTools.php
 330          *
 331          * @param $ip String
 332          * @return Boolean
 333          */
 334         public static function isPublic( $ip ) {
 335                 if ( self::isIPv6( $ip ) ) {
 336                         return self::isPublic6( $ip );
 337                 }
 338                 $n = self::toUnsigned( $ip );
 339                 if ( !$n ) {
 340                         return false;
 341                 }
 342
 343                 // ip2long accepts incomplete addresses, as well as some addresses
 344                 // followed by garbage characters. Check that it's really valid.
 345                 if ( $ip != long2ip( $n ) ) {
 346                         return false;
 347                 }
 348
 349                 static $privateRanges = false;
 350                 if ( !$privateRanges ) {
 351                         $privateRanges = array(
 352                                 array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 353                                 array( '172.16.0.0',  '172.31.255.255' ),   #     "
 354                                 array( '192.168.0.0', '192.168.255.255' ),  #     "
 355                                 array( '0.0.0.0',     '0.255.255.255' ),    # this network
 356                                 array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 357                         );
 358                 }
 359
 360                 foreach ( $privateRanges as $r ) {
 361                         $start = self::toUnsigned( $r[0] );
 362                         $end = self::toUnsigned( $r[1] );
 363                         if ( $n >= $start && $n <= $end ) {
 364                                 return false;
 365                         }
 366                 }
 367                 return true;
 368         }
 369
 370         /**
 371          * Determine if an IPv6 address really is an IP address, and if it is public,
 372          * i.e. not RFC 4193 or similar
 373          *
 374          * @param $ip String
 375          * @return Boolean
 376          */
 377         private static function isPublic6( $ip ) {
 378                 static $privateRanges = false;
 379                 if ( !$privateRanges ) {
 380                         $privateRanges = array(
 381                                 array( 'fc00::', 'fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff' ), # RFC 4193 (local)
 382                                 array( '0:0:0:0:0:0:0:1', '0:0:0:0:0:0:0:1' ), # loopback
 383                         );
 384                 }
 385                 $n = self::toHex( $ip );
 386                 foreach ( $privateRanges as $r ) {
 387                         $start = self::toHex( $r[0] );
 388                         $end = self::toHex( $r[1] );
 389                         if ( $n >= $start && $n <= $end ) {
 390                                 return false;
 391                         }
 392                 }
 393                 return true;
 394         }
 395
 396         /**
 397          * Return a zero-padded upper case hexadecimal representation of an IP address.
 398          *
 399          * Hexadecimal addresses are used because they can easily be extended to
 400          * IPv6 support. To separate the ranges, the return value from this
 401          * function for an IPv6 address will be prefixed with "v6-", a non-
 402          * hexadecimal string which sorts after the IPv4 addresses.
 403          *
 404          * @param $ip String: quad dotted/octet IP address.
 405          * @return String
 406          */
 407         public static function toHex( $ip ) {
 408                 if ( self::isIPv6( $ip ) ) {
 409                         $n = 'v6-' . self::IPv6ToRawHex( $ip );
 410                 } else {
 411                         $n = self::toUnsigned( $ip );
 412                         if ( $n !== false ) {
 413                                 $n = wfBaseConvert( $n, 10, 16, 8, false );
 414                         }
 415                 }
 416                 return $n;
 417         }
 418
 419         /**
 420          * Given an IPv6 address in octet notation, returns a pure hex string.
 421          *
 422          * @param $ip String: octet ipv6 IP address.
 423          * @return String: pure hex (uppercase)
 424          */
 425         private static function IPv6ToRawHex( $ip ) {
 426                 $ip = self::sanitizeIP( $ip );
 427                 if ( !$ip ) {
 428                         return null;
 429                 }
 430                 $r_ip = '';
 431                 foreach ( explode( ':', $ip ) as $v ) {
 432                         $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
 433                 }
 434                 return $r_ip;
 435         }
 436
 437         /**
 438          * Given an IP address in dotted-quad/octet notation, returns an unsigned integer.
 439          * Like ip2long() except that it actually works and has a consistent error return value.
 440          * Comes from ProxyTools.php
 441          *
 442          * @param $ip String: quad dotted IP address.
 443          * @return Mixed: string/int/false
 444          */
 445         public static function toUnsigned( $ip ) {
 446                 if ( self::isIPv6( $ip ) ) {
 447                         $n = self::toUnsigned6( $ip );
 448                 } else {
 449                         $n = ip2long( $ip );
 450                         if ( $n < 0 ) {
 451                                 $n += pow( 2, 32 );
 452                         }
 453                 }
 454                 return $n;
 455         }
 456
 457         /**
 458          * @param $ip
 459          * @return String
 460          */
 461         private static function toUnsigned6( $ip ) {
 462                 return wfBaseConvert( self::IPv6ToRawHex( $ip ), 16, 10 );
 463         }
 464
 465         /**
 466          * Convert a network specification in CIDR notation
 467          * to an integer network and a number of bits
 468          *
 469          * @param $range String: IP with CIDR prefix
 470          * @return array(int or string, int)
 471          */
 472         public static function parseCIDR( $range ) {
 473                 if ( self::isIPv6( $range ) ) {
 474                         return self::parseCIDR6( $range );
 475                 }
 476                 $parts = explode( '/', $range, 2 );
 477                 if ( count( $parts ) != 2 ) {
 478                         return array( false, false );
 479                 }
 480                 list( $network, $bits ) = $parts;
 481                 $network = ip2long( $network );
 482                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 483                         if ( $bits == 0 ) {
 484                                 $network = 0;
 485                         } else {
 486                                 $network &= ~( ( 1 << ( 32 - $bits ) ) - 1);
 487                         }
 488                         # Convert to unsigned
 489                         if ( $network < 0 ) {
 490                                 $network += pow( 2, 32 );
 491                         }
 492                 } else {
 493                         $network = false;
 494                         $bits = false;
 495                 }
 496                 return array( $network, $bits );
 497         }
 498
 499         /**
 500          * Given a string range in a number of formats,
 501          * return the start and end of the range in hexadecimal.
 502          *
 503          * Formats are:
 504          *     1.2.3.4/24          CIDR
 505          *     1.2.3.4 - 1.2.3.5   Explicit range
 506          *     1.2.3.4             Single IP
 507          *
 508          *     2001:0db8:85a3::7344/96                                   CIDR
 509          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 510          *     2001:0db8:85a3::7344                                      Single IP
 511          * @param $range String: IP range
 512          * @return array(string, string)
 513          */
 514         public static function parseRange( $range ) {
 515                 // CIDR notation
 516                 if ( strpos( $range, '/' ) !== false ) {
 517                         if ( self::isIPv6( $range ) ) {
 518                                 return self::parseRange6( $range );
 519                         }
 520                         list( $network, $bits ) = self::parseCIDR( $range );
 521                         if ( $network === false ) {
 522                                 $start = $end = false;
 523                         } else {
 524                                 $start = sprintf( '%08X', $network );
 525                                 $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
 526                         }
 527                 // Explicit range
 528                 } elseif ( strpos( $range, '-' ) !== false ) {
 529                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 530                         if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
 531                                 return self::parseRange6( $range );
 532                         }
 533                         if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
 534                                 $start = self::toUnsigned( $start );
 535                                 $end = self::toUnsigned( $end );
 536                                 if ( $start > $end ) {
 537                                         $start = $end = false;
 538                                 } else {
 539                                         $start = sprintf( '%08X', $start );
 540                                         $end = sprintf( '%08X', $end );
 541                                 }
 542                         } else {
 543                                 $start = $end = false;
 544                         }
 545                 } else {
 546                         # Single IP
 547                         $start = $end = self::toHex( $range );
 548                 }
 549                 if ( $start === false || $end === false ) {
 550                         return array( false, false );
 551                 } else {
 552                         return array( $start, $end );
 553                 }
 554         }
 555
 556         /**
 557          * Convert a network specification in IPv6 CIDR notation to an
 558          * integer network and a number of bits
 559          *
 560          * @param $range
 561          *
 562          * @return array(string, int)
 563          */
 564         private static function parseCIDR6( $range ) {
 565                 # Explode into <expanded IP,range>
 566                 $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
 567                 if ( count( $parts ) != 2 ) {
 568                         return array( false, false );
 569                 }
 570                 list( $network, $bits ) = $parts;
 571                 $network = self::IPv6ToRawHex( $network );
 572                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
 573                         if ( $bits == 0 ) {
 574                                 $network = "0";
 575                         } else {
 576                                 # Native 32 bit functions WONT work here!!!
 577                                 # Convert to a padded binary number
 578                                 $network = wfBaseConvert( $network, 16, 2, 128 );
 579                                 # Truncate the last (128-$bits) bits and replace them with zeros
 580                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 581                                 # Convert back to an integer
 582                                 $network = wfBaseConvert( $network, 2, 10 );
 583                         }
 584                 } else {
 585                         $network = false;
 586                         $bits = false;
 587                 }
 588                 return array( $network, (int)$bits );
 589         }
 590
 591         /**
 592          * Given a string range in a number of formats, return the
 593          * start and end of the range in hexadecimal. For IPv6.
 594          *
 595          * Formats are:
 596          *     2001:0db8:85a3::7344/96                                   CIDR
 597          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 598          *     2001:0db8:85a3::7344/96                                   Single IP
 599          *
 600          * @param $range
 601          *
 602          * @return array(string, string)
 603          */
 604         private static function parseRange6( $range ) {
 605                 # Expand any IPv6 IP
 606                 $range = IP::sanitizeIP( $range );
 607                 // CIDR notation...
 608                 if ( strpos( $range, '/' ) !== false ) {
 609                         list( $network, $bits ) = self::parseCIDR6( $range );
 610                         if ( $network === false ) {
 611                                 $start = $end = false;
 612                         } else {
 613                                 $start = wfBaseConvert( $network, 10, 16, 32, false );
 614                                 # Turn network to binary (again)
 615                                 $end = wfBaseConvert( $network, 10, 2, 128 );
 616                                 # Truncate the last (128-$bits) bits and replace them with ones
 617                                 $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
 618                                 # Convert to hex
 619                                 $end = wfBaseConvert( $end, 2, 16, 32, false );
 620                                 # see toHex() comment
 621                                 $start = "v6-$start";
 622                                 $end = "v6-$end";
 623                         }
 624                 // Explicit range notation...
 625                 } elseif ( strpos( $range, '-' ) !== false ) {
 626                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 627                         $start = self::toUnsigned6( $start );
 628                         $end = self::toUnsigned6( $end );
 629                         if ( $start > $end ) {
 630                                 $start = $end = false;
 631                         } else {
 632                                 $start = wfBaseConvert( $start, 10, 16, 32, false );
 633                                 $end = wfBaseConvert( $end, 10, 16, 32, false );
 634                         }
 635                         # see toHex() comment
 636                         $start = "v6-$start";
 637                         $end = "v6-$end";
 638                 } else {
 639                         # Single IP
 640                         $start = $end = self::toHex( $range );
 641                 }
 642                 if ( $start === false || $end === false ) {
 643                         return array( false, false );
 644                 } else {
 645                         return array( $start, $end );
 646                 }
 647         }
 648
 649         /**
 650          * Determine if a given IPv4/IPv6 address is in a given CIDR network
 651          *
 652          * @param $addr String: the address to check against the given range.
 653          * @param $range String: the range to check the given address against.
 654          * @return Boolean: whether or not the given address is in the given range.
 655          */
 656         public static function isInRange( $addr, $range ) {
 657                 $hexIP = self::toHex( $addr );
 658                 list( $start, $end ) = self::parseRange( $range );
 659                 return ( strcmp( $hexIP, $start ) >= 0 &&
 660                         strcmp( $hexIP, $end ) <= 0 );
 661         }
 662
 663         /**
 664          * Convert some unusual representations of IPv4 addresses to their
 665          * canonical dotted quad representation.
 666          *
 667          * This currently only checks a few IPV4-to-IPv6 related cases.  More
 668          * unusual representations may be added later.
 669          *
 670          * @param $addr String: something that might be an IP address
 671          * @return String: valid dotted quad IPv4 address or null
 672          */
 673         public static function canonicalize( $addr ) {
 674                 if ( self::isValid( $addr ) ) {
 675                         return $addr;
 676                 }
 677                 // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
 678                 if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
 679                         $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
 680                         if ( self::isIPv4( $addr ) ) {
 681                                 return $addr;
 682                         }
 683                 }
 684                 // IPv6 loopback address
 685                 $m = array();
 686                 if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) ) {
 687                         return '127.0.0.1';
 688                 }
 689                 // IPv4-mapped and IPv4-compatible IPv6 addresses
 690                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) ) {
 691                         return $m[1];
 692                 }
 693                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD .
 694                         ':' . RE_IPV6_WORD . '$/i', $addr, $m ) )
 695                 {
 696                         return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 697                 }
 698
 699                 return null;  // give up
 700         }
 701
 702         /**
 703          * Gets rid of uneeded numbers in quad-dotted/octet IP strings
 704          * For example, 127.111.113.151/24 -> 127.111.113.0/24
 705          * @param $range String: IP address to normalize
 706          * @return string
 707          */
 708         public static function sanitizeRange( $range ) {
 709                 list( /*...*/, $bits ) = self::parseCIDR( $range );
 710                 list( $start, /*...*/ ) = self::parseRange( $range );
 711                 $start = self::formatHex( $start );
 712                 if ( $bits === false ) {
 713                         return $start; // wasn't actually a range
 714                 }
 715                 return "$start/$bits";
 716         }
 717 }