includes/libs/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 use IPSet\IPSet;
  25
  26 // Some regex definition to "play" with IP address and IP address blocks
  27
  28 // An IPv4 address is made of 4 bytes from x00 to xFF which is d0 to d255
  29 define( 'RE_IP_BYTE', '(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|0?[0-9]?[0-9])' );
  30 define( 'RE_IP_ADD', RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
  31 // An IPv4 block is an IP address and a prefix (d1 to d32)
  32 define( 'RE_IP_PREFIX', '(3[0-2]|[12]?\d)' );
  33 define( 'RE_IP_BLOCK', RE_IP_ADD . '\/' . RE_IP_PREFIX );
  34
  35 // An IPv6 address is made up of 8 words (each x0000 to xFFFF).
  36 // However, the "::" abbreviation can be used on consecutive x0000 words.
  37 define( 'RE_IPV6_WORD', '([0-9A-Fa-f]{1,4})' );
  38 define( 'RE_IPV6_PREFIX', '(12[0-8]|1[01][0-9]|[1-9]?\d)' );
  39 define( 'RE_IPV6_ADD',
  40         '(?:' . // starts with "::" (including "::")
  41                 ':(?::|(?::' . RE_IPV6_WORD . '){1,7})' .
  42         '|' . // ends with "::" (except "::")
  43                 RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,6}::' .
  44         '|' . // contains one "::" in the middle (the ^ makes the test fail if none found)
  45                 RE_IPV6_WORD . '(?::((?(-1)|:))?' . RE_IPV6_WORD . '){1,6}(?(-2)|^)' .
  46         '|' . // contains no "::"
  47                 RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){7}' .
  48         ')'
  49 );
  50 // An IPv6 block is an IP address and a prefix (d1 to d128)
  51 define( 'RE_IPV6_BLOCK', RE_IPV6_ADD . '\/' . RE_IPV6_PREFIX );
  52 // For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
  53 define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
  54 define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );
  55
  56 // This might be useful for regexps used elsewhere, matches any IPv4 or IPv6 address or network
  57 define( 'IP_ADDRESS_STRING',
  58         '(?:' .
  59                 RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?' . // IPv4
  60         '|' .
  61                 RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?' . // IPv6
  62         ')'
  63 );
  64
  65 /**
  66  * A collection of public static functions to play with IP address
  67  * and IP blocks.
  68  */
  69 class IP {
  70         /** @var IPSet */
  71         private static $proxyIpSet = null;
  72
  73         /**
  74          * Determine if a string is as valid IP address or network (CIDR prefix).
  75          * SIIT IPv4-translated addresses are rejected.
  76          * @note canonicalize() tries to convert translated addresses to IPv4.
  77          *
  78          * @param string $ip Possible IP address
  79          * @return bool
  80          */
  81         public static function isIPAddress( $ip ) {
  82                 return (bool)preg_match( '/^' . IP_ADDRESS_STRING . '$/', $ip );
  83         }
  84
  85         /**
  86          * Given a string, determine if it as valid IP in IPv6 only.
  87          * @note Unlike isValid(), this looks for networks too.
  88          *
  89          * @param string $ip Possible IP address
  90          * @return bool
  91          */
  92         public static function isIPv6( $ip ) {
  93                 return (bool)preg_match( '/^' . RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?$/', $ip );
  94         }
  95
  96         /**
  97          * Given a string, determine if it as valid IP in IPv4 only.
  98          * @note Unlike isValid(), this looks for networks too.
  99          *
 100          * @param string $ip Possible IP address
 101          * @return bool
 102          */
 103         public static function isIPv4( $ip ) {
 104                 return (bool)preg_match( '/^' . RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?$/', $ip );
 105         }
 106
 107         /**
 108          * Validate an IP address. Ranges are NOT considered valid.
 109          * SIIT IPv4-translated addresses are rejected.
 110          * @note canonicalize() tries to convert translated addresses to IPv4.
 111          *
 112          * @param string $ip
 113          * @return bool True if it is valid
 114          */
 115         public static function isValid( $ip ) {
 116                 return ( preg_match( '/^' . RE_IP_ADD . '$/', $ip )
 117                         || preg_match( '/^' . RE_IPV6_ADD . '$/', $ip ) );
 118         }
 119
 120         /**
 121          * Validate an IP Block (valid address WITH a valid prefix).
 122          * SIIT IPv4-translated addresses are rejected.
 123          * @note canonicalize() tries to convert translated addresses to IPv4.
 124          *
 125          * @param string $ipblock
 126          * @return bool True if it is valid
 127          */
 128         public static function isValidBlock( $ipblock ) {
 129                 return ( preg_match( '/^' . RE_IPV6_BLOCK . '$/', $ipblock )
 130                         || preg_match( '/^' . RE_IP_BLOCK . '$/', $ipblock ) );
 131         }
 132
 133         /**
 134          * Convert an IP into a verbose, uppercase, normalized form.
 135          * Both IPv4 and IPv6 addresses are trimmed. Additionally,
 136          * IPv6 addresses in octet notation are expanded to 8 words;
 137          * IPv4 addresses have leading zeros, in each octet, removed.
 138          *
 139          * @param string $ip IP address in quad or octet form (CIDR or not).
 140          * @return string
 141          */
 142         public static function sanitizeIP( $ip ) {
 143                 $ip = trim( $ip );
 144                 if ( $ip === '' ) {
 145                         return null;
 146                 }
 147                 /* If not an IP, just return trimmed value, since sanitizeIP() is called
 148                  * in a number of contexts where usernames are supplied as input.
 149                  */
 150                 if ( !self::isIPAddress( $ip ) ) {
 151                         return $ip;
 152                 }
 153                 if ( self::isIPv4( $ip ) ) {
 154                         // Remove leading 0's from octet representation of IPv4 address
 155                         $ip = preg_replace( '/(?:^|(?<=\.))0+(?=[1-9]|0\.|0$)/', '', $ip );
 156                         return $ip;
 157                 }
 158                 // Remove any whitespaces, convert to upper case
 159                 $ip = strtoupper( $ip );
 160                 // Expand zero abbreviations
 161                 $abbrevPos = strpos( $ip, '::' );
 162                 if ( $abbrevPos !== false ) {
 163                         // We know this is valid IPv6. Find the last index of the
 164                         // address before any CIDR number (e.g. "a:b:c::/24").
 165                         $CIDRStart = strpos( $ip, "/" );
 166                         $addressEnd = ( $CIDRStart !== false )
 167                                 ? $CIDRStart - 1
 168                                 : strlen( $ip ) - 1;
 169                         // If the '::' is at the beginning...
 170                         if ( $abbrevPos == 0 ) {
 171                                 $repeat = '0:';
 172                                 $extra = ( $ip == '::' ) ? '0' : ''; // for the address '::'
 173                                 $pad = 9; // 7+2 (due to '::')
 174                         // If the '::' is at the end...
 175                         } elseif ( $abbrevPos == ( $addressEnd - 1 ) ) {
 176                                 $repeat = ':0';
 177                                 $extra = '';
 178                                 $pad = 9; // 7+2 (due to '::')
 179                         // If the '::' is in the middle...
 180                         } else {
 181                                 $repeat = ':0';
 182                                 $extra = ':';
 183                                 $pad = 8; // 6+2 (due to '::')
 184                         }
 185                         $ip = str_replace( '::',
 186                                 str_repeat( $repeat, $pad - substr_count( $ip, ':' ) ) . $extra,
 187                                 $ip
 188                         );
 189                 }
 190                 // Remove leading zeros from each bloc as needed
 191                 $ip = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip );
 192
 193                 return $ip;
 194         }
 195
 196         /**
 197          * Prettify an IP for display to end users.
 198          * This will make it more compact and lower-case.
 199          *
 200          * @param string $ip
 201          * @return string
 202          */
 203         public static function prettifyIP( $ip ) {
 204                 $ip = self::sanitizeIP( $ip ); // normalize (removes '::')
 205                 if ( self::isIPv6( $ip ) ) {
 206                         // Split IP into an address and a CIDR
 207                         if ( strpos( $ip, '/' ) !== false ) {
 208                                 list( $ip, $cidr ) = explode( '/', $ip, 2 );
 209                         } else {
 210                                 list( $ip, $cidr ) = [ $ip, '' ];
 211                         }
 212                         // Get the largest slice of words with multiple zeros
 213                         $offset = 0;
 214                         $longest = $longestPos = false;
 215                         while ( preg_match(
 216                                 '!(?:^|:)0(?::0)+(?:$|:)!', $ip, $m, PREG_OFFSET_CAPTURE, $offset
 217                         ) ) {
 218                                 list( $match, $pos ) = $m[0]; // full match
 219                                 if ( strlen( $match ) > strlen( $longest ) ) {
 220                                         $longest = $match;
 221                                         $longestPos = $pos;
 222                                 }
 223                                 $offset = ( $pos + strlen( $match ) ); // advance
 224                         }
 225                         if ( $longest !== false ) {
 226                                 // Replace this portion of the string with the '::' abbreviation
 227                                 $ip = substr_replace( $ip, '::', $longestPos, strlen( $longest ) );
 228                         }
 229                         // Add any CIDR back on
 230                         if ( $cidr !== '' ) {
 231                                 $ip = "{$ip}/{$cidr}";
 232                         }
 233                         // Convert to lower case to make it more readable
 234                         $ip = strtolower( $ip );
 235                 }
 236
 237                 return $ip;
 238         }
 239
 240         /**
 241          * Given a host/port string, like one might find in the host part of a URL
 242          * per RFC 2732, split the hostname part and the port part and return an
 243          * array with an element for each. If there is no port part, the array will
 244          * have false in place of the port. If the string was invalid in some way,
 245          * false is returned.
 246          *
 247          * This was easy with IPv4 and was generally done in an ad-hoc way, but
 248          * with IPv6 it's somewhat more complicated due to the need to parse the
 249          * square brackets and colons.
 250          *
 251          * A bare IPv6 address is accepted despite the lack of square brackets.
 252          *
 253          * @param string $both The string with the host and port
 254          * @return array|false Array normally, false on certain failures
 255          */
 256         public static function splitHostAndPort( $both ) {
 257                 if ( substr( $both, 0, 1 ) === '[' ) {
 258                         if ( preg_match( '/^\[(' . RE_IPV6_ADD . ')\](?::(?P<port>\d+))?$/', $both, $m ) ) {
 259                                 if ( isset( $m['port'] ) ) {
 260                                         return [ $m[1], intval( $m['port'] ) ];
 261                                 } else {
 262                                         return [ $m[1], false ];
 263                                 }
 264                         } else {
 265                                 // Square bracket found but no IPv6
 266                                 return false;
 267                         }
 268                 }
 269                 $numColons = substr_count( $both, ':' );
 270                 if ( $numColons >= 2 ) {
 271                         // Is it a bare IPv6 address?
 272                         if ( preg_match( '/^' . RE_IPV6_ADD . '$/', $both ) ) {
 273                                 return [ $both, false ];
 274                         } else {
 275                                 // Not valid IPv6, but too many colons for anything else
 276                                 return false;
 277                         }
 278                 }
 279                 if ( $numColons >= 1 ) {
 280                         // Host:port?
 281                         $bits = explode( ':', $both );
 282                         if ( preg_match( '/^\d+/', $bits[1] ) ) {
 283                                 return [ $bits[0], intval( $bits[1] ) ];
 284                         } else {
 285                                 // Not a valid port
 286                                 return false;
 287                         }
 288                 }
 289
 290                 // Plain hostname
 291                 return [ $both, false ];
 292         }
 293
 294         /**
 295          * Given a host name and a port, combine them into host/port string like
 296          * you might find in a URL. If the host contains a colon, wrap it in square
 297          * brackets like in RFC 2732. If the port matches the default port, omit
 298          * the port specification
 299          *
 300          * @param string $host
 301          * @param int $port
 302          * @param bool|int $defaultPort
 303          * @return string
 304          */
 305         public static function combineHostAndPort( $host, $port, $defaultPort = false ) {
 306                 if ( strpos( $host, ':' ) !== false ) {
 307                         $host = "[$host]";
 308                 }
 309                 if ( $defaultPort !== false && $port == $defaultPort ) {
 310                         return $host;
 311                 } else {
 312                         return "$host:$port";
 313                 }
 314         }
 315
 316         /**
 317          * Convert an IPv4 or IPv6 hexadecimal representation back to readable format
 318          *
 319          * @param string $hex 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 string $ip_hex 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
 347                 return $ip_oct;
 348         }
 349
 350         /**
 351          * Converts a hexadecimal number to an IPv4 address in quad-dotted notation
 352          *
 353          * @param string $ip_hex Pure hex
 354          * @return string (of format a.b.c.d)
 355          */
 356         public static function hexToQuad( $ip_hex ) {
 357                 // Pad hex to 8 chars (32 bits)
 358                 $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
 359                 // Separate into four quads
 360                 $s = '';
 361                 for ( $i = 0; $i < 4; $i++ ) {
 362                         if ( $s !== '' ) {
 363                                 $s .= '.';
 364                         }
 365                         $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
 366                 }
 367
 368                 return $s;
 369         }
 370
 371         /**
 372          * Determine if an IP address really is an IP address, and if it is public,
 373          * i.e. not RFC 1918 or similar
 374          *
 375          * @param string $ip
 376          * @return bool
 377          */
 378         public static function isPublic( $ip ) {
 379                 static $privateSet = null;
 380                 if ( !$privateSet ) {
 381                         $privateSet = new IPSet( [
 382                                 '10.0.0.0/8', # RFC 1918 (private)
 383                                 '172.16.0.0/12', # RFC 1918 (private)
 384                                 '192.168.0.0/16', # RFC 1918 (private)
 385                                 '0.0.0.0/8', # this network
 386                                 '127.0.0.0/8', # loopback
 387                                 'fc00::/7', # RFC 4193 (local)
 388                                 '0:0:0:0:0:0:0:1', # loopback
 389                                 '169.254.0.0/16', # link-local
 390                                 'fe80::/10', # link-local
 391                         ] );
 392                 }
 393                 return !$privateSet->match( $ip );
 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 string $ip Quad dotted/octet IP address.
 405          * @return string|bool False on failure
 406          */
 407         public static function toHex( $ip ) {
 408                 if ( self::isIPv6( $ip ) ) {
 409                         $n = 'v6-' . self::IPv6ToRawHex( $ip );
 410                 } elseif ( self::isIPv4( $ip ) ) {
 411                         // T62035/T97897: An IP with leading 0's fails in ip2long sometimes (e.g. *.08),
 412                         // also double/triple 0 needs to be changed to just a single 0 for ip2long.
 413                         $ip = self::sanitizeIP( $ip );
 414                         $n = ip2long( $ip );
 415                         if ( $n < 0 ) {
 416                                 $n += pow( 2, 32 );
 417                                 # On 32-bit platforms (and on Windows), 2^32 does not fit into an int,
 418                                 # so $n becomes a float. We convert it to string instead.
 419                                 if ( is_float( $n ) ) {
 420                                         $n = (string)$n;
 421                                 }
 422                         }
 423                         if ( $n !== false ) {
 424                                 # Floating points can handle the conversion; faster than Wikimedia\base_convert()
 425                                 $n = strtoupper( str_pad( base_convert( $n, 10, 16 ), 8, '0', STR_PAD_LEFT ) );
 426                         }
 427                 } else {
 428                         $n = false;
 429                 }
 430
 431                 return $n;
 432         }
 433
 434         /**
 435          * Given an IPv6 address in octet notation, returns a pure hex string.
 436          *
 437          * @param string $ip Octet ipv6 IP address.
 438          * @return string|bool Pure hex (uppercase); false on failure
 439          */
 440         private static function IPv6ToRawHex( $ip ) {
 441                 $ip = self::sanitizeIP( $ip );
 442                 if ( !$ip ) {
 443                         return false;
 444                 }
 445                 $r_ip = '';
 446                 foreach ( explode( ':', $ip ) as $v ) {
 447                         $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
 448                 }
 449
 450                 return $r_ip;
 451         }
 452
 453         /**
 454          * Convert a network specification in CIDR notation
 455          * to an integer network and a number of bits
 456          *
 457          * @param string $range IP with CIDR prefix
 458          * @return array(int or string, int)
 459          */
 460         public static function parseCIDR( $range ) {
 461                 if ( self::isIPv6( $range ) ) {
 462                         return self::parseCIDR6( $range );
 463                 }
 464                 $parts = explode( '/', $range, 2 );
 465                 if ( count( $parts ) != 2 ) {
 466                         return [ false, false ];
 467                 }
 468                 list( $network, $bits ) = $parts;
 469                 $network = ip2long( $network );
 470                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 471                         if ( $bits == 0 ) {
 472                                 $network = 0;
 473                         } else {
 474                                 $network &= ~( ( 1 << ( 32 - $bits ) ) - 1 );
 475                         }
 476                         # Convert to unsigned
 477                         if ( $network < 0 ) {
 478                                 $network += pow( 2, 32 );
 479                         }
 480                 } else {
 481                         $network = false;
 482                         $bits = false;
 483                 }
 484
 485                 return [ $network, $bits ];
 486         }
 487
 488         /**
 489          * Given a string range in a number of formats,
 490          * return the start and end of the range in hexadecimal.
 491          *
 492          * Formats are:
 493          *     1.2.3.4/24          CIDR
 494          *     1.2.3.4 - 1.2.3.5   Explicit range
 495          *     1.2.3.4             Single IP
 496          *
 497          *     2001:0db8:85a3::7344/96                       CIDR
 498          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 499          *     2001:0db8:85a3::7344                          Single IP
 500          * @param string $range IP range
 501          * @return array(string, string)
 502          */
 503         public static function parseRange( $range ) {
 504                 // CIDR notation
 505                 if ( strpos( $range, '/' ) !== false ) {
 506                         if ( self::isIPv6( $range ) ) {
 507                                 return self::parseRange6( $range );
 508                         }
 509                         list( $network, $bits ) = self::parseCIDR( $range );
 510                         if ( $network === false ) {
 511                                 $start = $end = false;
 512                         } else {
 513                                 $start = sprintf( '%08X', $network );
 514                                 $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
 515                         }
 516                 // Explicit range
 517                 } elseif ( strpos( $range, '-' ) !== false ) {
 518                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 519                         if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
 520                                 return self::parseRange6( $range );
 521                         }
 522                         if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
 523                                 $start = self::toHex( $start );
 524                                 $end = self::toHex( $end );
 525                                 if ( $start > $end ) {
 526                                         $start = $end = false;
 527                                 }
 528                         } else {
 529                                 $start = $end = false;
 530                         }
 531                 } else {
 532                         # Single IP
 533                         $start = $end = self::toHex( $range );
 534                 }
 535                 if ( $start === false || $end === false ) {
 536                         return [ false, false ];
 537                 } else {
 538                         return [ $start, $end ];
 539                 }
 540         }
 541
 542         /**
 543          * Convert a network specification in IPv6 CIDR notation to an
 544          * integer network and a number of bits
 545          *
 546          * @param string $range
 547          *
 548          * @return array(string, int)
 549          */
 550         private static function parseCIDR6( $range ) {
 551                 # Explode into <expanded IP,range>
 552                 $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
 553                 if ( count( $parts ) != 2 ) {
 554                         return [ false, false ];
 555                 }
 556                 list( $network, $bits ) = $parts;
 557                 $network = self::IPv6ToRawHex( $network );
 558                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
 559                         if ( $bits == 0 ) {
 560                                 $network = "0";
 561                         } else {
 562                                 # Native 32 bit functions WONT work here!!!
 563                                 # Convert to a padded binary number
 564                                 $network = Wikimedia\base_convert( $network, 16, 2, 128 );
 565                                 # Truncate the last (128-$bits) bits and replace them with zeros
 566                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 567                                 # Convert back to an integer
 568                                 $network = Wikimedia\base_convert( $network, 2, 10 );
 569                         }
 570                 } else {
 571                         $network = false;
 572                         $bits = false;
 573                 }
 574
 575                 return [ $network, (int)$bits ];
 576         }
 577
 578         /**
 579          * Given a string range in a number of formats, return the
 580          * start and end of the range in hexadecimal. For IPv6.
 581          *
 582          * Formats are:
 583          *     2001:0db8:85a3::7344/96                       CIDR
 584          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 585          *     2001:0db8:85a3::7344/96                       Single IP
 586          *
 587          * @param string $range
 588          *
 589          * @return array(string, string)
 590          */
 591         private static function parseRange6( $range ) {
 592                 # Expand any IPv6 IP
 593                 $range = IP::sanitizeIP( $range );
 594                 // CIDR notation...
 595                 if ( strpos( $range, '/' ) !== false ) {
 596                         list( $network, $bits ) = self::parseCIDR6( $range );
 597                         if ( $network === false ) {
 598                                 $start = $end = false;
 599                         } else {
 600                                 $start = Wikimedia\base_convert( $network, 10, 16, 32, false );
 601                                 # Turn network to binary (again)
 602                                 $end = Wikimedia\base_convert( $network, 10, 2, 128 );
 603                                 # Truncate the last (128-$bits) bits and replace them with ones
 604                                 $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
 605                                 # Convert to hex
 606                                 $end = Wikimedia\base_convert( $end, 2, 16, 32, false );
 607                                 # see toHex() comment
 608                                 $start = "v6-$start";
 609                                 $end = "v6-$end";
 610                         }
 611                 // Explicit range notation...
 612                 } elseif ( strpos( $range, '-' ) !== false ) {
 613                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 614                         $start = self::toHex( $start );
 615                         $end = self::toHex( $end );
 616                         if ( $start > $end ) {
 617                                 $start = $end = false;
 618                         }
 619                 } else {
 620                         # Single IP
 621                         $start = $end = self::toHex( $range );
 622                 }
 623                 if ( $start === false || $end === false ) {
 624                         return [ false, false ];
 625                 } else {
 626                         return [ $start, $end ];
 627                 }
 628         }
 629
 630         /**
 631          * Determine if a given IPv4/IPv6 address is in a given CIDR network
 632          *
 633          * @param string $addr The address to check against the given range.
 634          * @param string $range The range to check the given address against.
 635          * @return bool Whether or not the given address is in the given range.
 636          *
 637          * @note This can return unexpected results for invalid arguments!
 638          *       Make sure you pass a valid IP address and IP range.
 639          */
 640         public static function isInRange( $addr, $range ) {
 641                 $hexIP = self::toHex( $addr );
 642                 list( $start, $end ) = self::parseRange( $range );
 643
 644                 return ( strcmp( $hexIP, $start ) >= 0 &&
 645                         strcmp( $hexIP, $end ) <= 0 );
 646         }
 647
 648         /**
 649          * Determines if an IP address is a list of CIDR a.b.c.d/n ranges.
 650          *
 651          * @since 1.25
 652          *
 653          * @param string $ip the IP to check
 654          * @param array $ranges the IP ranges, each element a range
 655          *
 656          * @return bool true if the specified adress belongs to the specified range; otherwise, false.
 657          */
 658         public static function isInRanges( $ip, $ranges ) {
 659                 foreach ( $ranges as $range ) {
 660                         if ( self::isInRange( $ip, $range ) ) {
 661                                 return true;
 662                         }
 663                 }
 664                 return false;
 665         }
 666
 667         /**
 668          * Convert some unusual representations of IPv4 addresses to their
 669          * canonical dotted quad representation.
 670          *
 671          * This currently only checks a few IPV4-to-IPv6 related cases.  More
 672          * unusual representations may be added later.
 673          *
 674          * @param string $addr Something that might be an IP address
 675          * @return string|null Valid dotted quad IPv4 address or null
 676          */
 677         public static function canonicalize( $addr ) {
 678                 // remove zone info (T37738)
 679                 $addr = preg_replace( '/\%.*/', '', $addr );
 680
 681                 if ( self::isValid( $addr ) ) {
 682                         return $addr;
 683                 }
 684                 // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
 685                 if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
 686                         $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
 687                         if ( self::isIPv4( $addr ) ) {
 688                                 return $addr;
 689                         }
 690                 }
 691                 // IPv6 loopback address
 692                 $m = [];
 693                 if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) ) {
 694                         return '127.0.0.1';
 695                 }
 696                 // IPv4-mapped and IPv4-compatible IPv6 addresses
 697                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) ) {
 698                         return $m[1];
 699                 }
 700                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD .
 701                         ':' . RE_IPV6_WORD . '$/i', $addr, $m )
 702                 ) {
 703                         return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 704                 }
 705
 706                 return null; // give up
 707         }
 708
 709         /**
 710          * Gets rid of unneeded numbers in quad-dotted/octet IP strings
 711          * For example, 127.111.113.151/24 -> 127.111.113.0/24
 712          * @param string $range IP address to normalize
 713          * @return string
 714          */
 715         public static function sanitizeRange( $range ) {
 716                 list( /*...*/, $bits ) = self::parseCIDR( $range );
 717                 list( $start, /*...*/ ) = self::parseRange( $range );
 718                 $start = self::formatHex( $start );
 719                 if ( $bits === false ) {
 720                         return $start; // wasn't actually a range
 721                 }
 722
 723                 return "$start/$bits";
 724         }
 725
 726         /**
 727          * Returns the subnet of a given IP
 728          *
 729          * @param string $ip
 730          * @return string|false
 731          */
 732         public static function getSubnet( $ip ) {
 733                 $matches = [];
 734                 $subnet = false;
 735                 if ( IP::isIPv6( $ip ) ) {
 736                         $parts = IP::parseRange( "$ip/64" );
 737                         $subnet = $parts[0];
 738                 } elseif ( preg_match( '/^(\d+\.\d+\.\d+)\.\d+$/', $ip, $matches ) ) {
 739                         // IPv4
 740                         $subnet = $matches[1];
 741                 }
 742                 return $subnet;
 743         }
 744 }