includes/utils/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         /** @var IPSet */
  69         private static $ipSet = null;
  70         /**
  71          * Determine if a string is as valid IP address or network (CIDR prefix).
  72          * SIIT IPv4-translated addresses are rejected.
  73          * Note: canonicalize() tries to convert translated addresses to IPv4.
  74          *
  75          * @param string $ip possible IP address
  76          * @return Boolean
  77          */
  78         public static function isIPAddress( $ip ) {
  79                 return (bool)preg_match( '/^' . IP_ADDRESS_STRING . '$/', $ip );
  80         }
  81
  82         /**
  83          * Given a string, determine if it as valid IP in IPv6 only.
  84          * Note: Unlike isValid(), this looks for networks too.
  85          *
  86          * @param string $ip possible IP address
  87          * @return Boolean
  88          */
  89         public static function isIPv6( $ip ) {
  90                 return (bool)preg_match( '/^' . RE_IPV6_ADD . '(?:\/' . RE_IPV6_PREFIX . ')?$/', $ip );
  91         }
  92
  93         /**
  94          * Given a string, determine if it as valid IP in IPv4 only.
  95          * Note: Unlike isValid(), this looks for networks too.
  96          *
  97          * @param string $ip possible IP address
  98          * @return Boolean
  99          */
 100         public static function isIPv4( $ip ) {
 101                 return (bool)preg_match( '/^' . RE_IP_ADD . '(?:\/' . RE_IP_PREFIX . ')?$/', $ip );
 102         }
 103
 104         /**
 105          * Validate an IP address. Ranges are NOT considered valid.
 106          * SIIT IPv4-translated addresses are rejected.
 107          * Note: canonicalize() tries to convert translated addresses to IPv4.
 108          *
 109          * @param $ip String
 110          * @return Boolean: True if it is valid.
 111          */
 112         public static function isValid( $ip ) {
 113                 return ( preg_match( '/^' . RE_IP_ADD . '$/', $ip )
 114                         || preg_match( '/^' . RE_IPV6_ADD . '$/', $ip ) );
 115         }
 116
 117         /**
 118          * Validate an IP Block (valid address WITH a valid prefix).
 119          * SIIT IPv4-translated addresses are rejected.
 120          * Note: canonicalize() tries to convert translated addresses to IPv4.
 121          *
 122          * @param $ipblock String
 123          * @return Boolean: True if it is valid.
 124          */
 125         public static function isValidBlock( $ipblock ) {
 126                 return ( preg_match( '/^' . RE_IPV6_BLOCK . '$/', $ipblock )
 127                         || preg_match( '/^' . RE_IP_BLOCK . '$/', $ipblock ) );
 128         }
 129
 130         /**
 131          * Convert an IP into a verbose, uppercase, normalized form.
 132          * IPv6 addresses in octet notation are expanded to 8 words.
 133          * IPv4 addresses are just trimmed.
 134          *
 135          * @param string $ip IP address in quad or octet form (CIDR or not).
 136          * @return String
 137          */
 138         public static function sanitizeIP( $ip ) {
 139                 $ip = trim( $ip );
 140                 if ( $ip === '' ) {
 141                         return null;
 142                 }
 143                 if ( self::isIPv4( $ip ) || !self::isIPv6( $ip ) ) {
 144                         return $ip; // nothing else to do for IPv4 addresses or invalid ones
 145                 }
 146                 // Remove any whitespaces, convert to upper case
 147                 $ip = strtoupper( $ip );
 148                 // Expand zero abbreviations
 149                 $abbrevPos = strpos( $ip, '::' );
 150                 if ( $abbrevPos !== false ) {
 151                         // We know this is valid IPv6. Find the last index of the
 152                         // address before any CIDR number (e.g. "a:b:c::/24").
 153                         $CIDRStart = strpos( $ip, "/" );
 154                         $addressEnd = ( $CIDRStart !== false )
 155                                 ? $CIDRStart - 1
 156                                 : strlen( $ip ) - 1;
 157                         // If the '::' is at the beginning...
 158                         if ( $abbrevPos == 0 ) {
 159                                 $repeat = '0:';
 160                                 $extra = ( $ip == '::' ) ? '0' : ''; // for the address '::'
 161                                 $pad = 9; // 7+2 (due to '::')
 162                         // If the '::' is at the end...
 163                         } elseif ( $abbrevPos == ( $addressEnd - 1 ) ) {
 164                                 $repeat = ':0';
 165                                 $extra = '';
 166                                 $pad = 9; // 7+2 (due to '::')
 167                         // If the '::' is in the middle...
 168                         } else {
 169                                 $repeat = ':0';
 170                                 $extra = ':';
 171                                 $pad = 8; // 6+2 (due to '::')
 172                         }
 173                         $ip = str_replace( '::',
 174                                 str_repeat( $repeat, $pad - substr_count( $ip, ':' ) ) . $extra,
 175                                 $ip
 176                         );
 177                 }
 178                 // Remove leading zeros from each bloc as needed
 179                 $ip = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip );
 180
 181                 return $ip;
 182         }
 183
 184         /**
 185          * Prettify an IP for display to end users.
 186          * This will make it more compact and lower-case.
 187          *
 188          * @param $ip string
 189          * @return string
 190          */
 191         public static function prettifyIP( $ip ) {
 192                 $ip = self::sanitizeIP( $ip ); // normalize (removes '::')
 193                 if ( self::isIPv6( $ip ) ) {
 194                         // Split IP into an address and a CIDR
 195                         if ( strpos( $ip, '/' ) !== false ) {
 196                                 list( $ip, $cidr ) = explode( '/', $ip, 2 );
 197                         } else {
 198                                 list( $ip, $cidr ) = array( $ip, '' );
 199                         }
 200                         // Get the largest slice of words with multiple zeros
 201                         $offset = 0;
 202                         $longest = $longestPos = false;
 203                         while ( preg_match(
 204                                 '!(?:^|:)0(?::0)+(?:$|:)!', $ip, $m, PREG_OFFSET_CAPTURE, $offset
 205                         ) ) {
 206                                 list( $match, $pos ) = $m[0]; // full match
 207                                 if ( strlen( $match ) > strlen( $longest ) ) {
 208                                         $longest = $match;
 209                                         $longestPos = $pos;
 210                                 }
 211                                 $offset = ( $pos + strlen( $match ) ); // advance
 212                         }
 213                         if ( $longest !== false ) {
 214                                 // Replace this portion of the string with the '::' abbreviation
 215                                 $ip = substr_replace( $ip, '::', $longestPos, strlen( $longest ) );
 216                         }
 217                         // Add any CIDR back on
 218                         if ( $cidr !== '' ) {
 219                                 $ip = "{$ip}/{$cidr}";
 220                         }
 221                         // Convert to lower case to make it more readable
 222                         $ip = strtolower( $ip );
 223                 }
 224
 225                 return $ip;
 226         }
 227
 228         /**
 229          * Given a host/port string, like one might find in the host part of a URL
 230          * per RFC 2732, split the hostname part and the port part and return an
 231          * array with an element for each. If there is no port part, the array will
 232          * have false in place of the port. If the string was invalid in some way,
 233          * false is returned.
 234          *
 235          * This was easy with IPv4 and was generally done in an ad-hoc way, but
 236          * with IPv6 it's somewhat more complicated due to the need to parse the
 237          * square brackets and colons.
 238          *
 239          * A bare IPv6 address is accepted despite the lack of square brackets.
 240          *
 241          * @param string $both The string with the host and port
 242          * @return array
 243          */
 244         public static function splitHostAndPort( $both ) {
 245                 if ( substr( $both, 0, 1 ) === '[' ) {
 246                         if ( preg_match( '/^\[(' . RE_IPV6_ADD . ')\](?::(?P<port>\d+))?$/', $both, $m ) ) {
 247                                 if ( isset( $m['port'] ) ) {
 248                                         return array( $m[1], intval( $m['port'] ) );
 249                                 } else {
 250                                         return array( $m[1], false );
 251                                 }
 252                         } else {
 253                                 // Square bracket found but no IPv6
 254                                 return false;
 255                         }
 256                 }
 257                 $numColons = substr_count( $both, ':' );
 258                 if ( $numColons >= 2 ) {
 259                         // Is it a bare IPv6 address?
 260                         if ( preg_match( '/^' . RE_IPV6_ADD . '$/', $both ) ) {
 261                                 return array( $both, false );
 262                         } else {
 263                                 // Not valid IPv6, but too many colons for anything else
 264                                 return false;
 265                         }
 266                 }
 267                 if ( $numColons >= 1 ) {
 268                         // Host:port?
 269                         $bits = explode( ':', $both );
 270                         if ( preg_match( '/^\d+/', $bits[1] ) ) {
 271                                 return array( $bits[0], intval( $bits[1] ) );
 272                         } else {
 273                                 // Not a valid port
 274                                 return false;
 275                         }
 276                 }
 277
 278                 // Plain hostname
 279                 return array( $both, false );
 280         }
 281
 282         /**
 283          * Given a host name and a port, combine them into host/port string like
 284          * you might find in a URL. If the host contains a colon, wrap it in square
 285          * brackets like in RFC 2732. If the port matches the default port, omit
 286          * the port specification
 287          *
 288          * @param $host string
 289          * @param $port int
 290          * @param $defaultPort bool|int
 291          * @return string
 292          */
 293         public static function combineHostAndPort( $host, $port, $defaultPort = false ) {
 294                 if ( strpos( $host, ':' ) !== false ) {
 295                         $host = "[$host]";
 296                 }
 297                 if ( $defaultPort !== false && $port == $defaultPort ) {
 298                         return $host;
 299                 } else {
 300                         return "$host:$port";
 301                 }
 302         }
 303
 304         /**
 305          * Given an unsigned integer, returns an IPv6 address in octet notation
 306          *
 307          * @param $ip_int String: IP address.
 308          * @return String
 309          */
 310         public static function toOctet( $ip_int ) {
 311                 return self::hexToOctet( wfBaseConvert( $ip_int, 10, 16, 32, false ) );
 312         }
 313
 314         /**
 315          * Convert an IPv4 or IPv6 hexadecimal representation back to readable format
 316          *
 317          * @param string $hex number, with "v6-" prefix if it is IPv6
 318          * @return String: quad-dotted (IPv4) or octet notation (IPv6)
 319          */
 320         public static function formatHex( $hex ) {
 321                 if ( substr( $hex, 0, 3 ) == 'v6-' ) { // IPv6
 322                         return self::hexToOctet( substr( $hex, 3 ) );
 323                 } else { // IPv4
 324                         return self::hexToQuad( $hex );
 325                 }
 326         }
 327
 328         /**
 329          * Converts a hexadecimal number to an IPv6 address in octet notation
 330          *
 331          * @param $ip_hex String: pure hex (no v6- prefix)
 332          * @return String (of format a:b:c:d:e:f:g:h)
 333          */
 334         public static function hexToOctet( $ip_hex ) {
 335                 // Pad hex to 32 chars (128 bits)
 336                 $ip_hex = str_pad( strtoupper( $ip_hex ), 32, '0', STR_PAD_LEFT );
 337                 // Separate into 8 words
 338                 $ip_oct = substr( $ip_hex, 0, 4 );
 339                 for ( $n = 1; $n < 8; $n++ ) {
 340                         $ip_oct .= ':' . substr( $ip_hex, 4 * $n, 4 );
 341                 }
 342                 // NO leading zeroes
 343                 $ip_oct = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip_oct );
 344
 345                 return $ip_oct;
 346         }
 347
 348         /**
 349          * Converts a hexadecimal number to an IPv4 address in quad-dotted notation
 350          *
 351          * @param $ip_hex String: pure hex
 352          * @return String (of format a.b.c.d)
 353          */
 354         public static function hexToQuad( $ip_hex ) {
 355                 // Pad hex to 8 chars (32 bits)
 356                 $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
 357                 // Separate into four quads
 358                 $s = '';
 359                 for ( $i = 0; $i < 4; $i++ ) {
 360                         if ( $s !== '' ) {
 361                                 $s .= '.';
 362                         }
 363                         $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
 364                 }
 365
 366                 return $s;
 367         }
 368
 369         /**
 370          * Determine if an IP address really is an IP address, and if it is public,
 371          * i.e. not RFC 1918 or similar
 372          *
 373          * @param $ip String
 374          * @return Boolean
 375          */
 376         public static function isPublic( $ip ) {
 377                 if ( self::isIPv6( $ip ) ) {
 378                         return self::isPublic6( $ip );
 379                 }
 380                 $n = self::toUnsigned( $ip );
 381                 if ( !$n ) {
 382                         return false;
 383                 }
 384
 385                 // ip2long accepts incomplete addresses, as well as some addresses
 386                 // followed by garbage characters. Check that it's really valid.
 387                 if ( $ip != long2ip( $n ) ) {
 388                         return false;
 389                 }
 390
 391                 static $privateRanges = false;
 392                 if ( !$privateRanges ) {
 393                         $privateRanges = array(
 394                                 array( '10.0.0.0', '10.255.255.255' ), # RFC 1918 (private)
 395                                 array( '172.16.0.0', '172.31.255.255' ), # RFC 1918 (private)
 396                                 array( '192.168.0.0', '192.168.255.255' ), # RFC 1918 (private)
 397                                 array( '0.0.0.0', '0.255.255.255' ), # this network
 398                                 array( '127.0.0.0', '127.255.255.255' ), # loopback
 399                         );
 400                 }
 401
 402                 foreach ( $privateRanges as $r ) {
 403                         $start = self::toUnsigned( $r[0] );
 404                         $end = self::toUnsigned( $r[1] );
 405                         if ( $n >= $start && $n <= $end ) {
 406                                 return false;
 407                         }
 408                 }
 409
 410                 return true;
 411         }
 412
 413         /**
 414          * Determine if an IPv6 address really is an IP address, and if it is public,
 415          * i.e. not RFC 4193 or similar
 416          *
 417          * @param $ip String
 418          * @return Boolean
 419          */
 420         private static function isPublic6( $ip ) {
 421                 static $privateRanges = false;
 422                 if ( !$privateRanges ) {
 423                         $privateRanges = array(
 424                                 array( 'fc00::', 'fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff' ), # RFC 4193 (local)
 425                                 array( '0:0:0:0:0:0:0:1', '0:0:0:0:0:0:0:1' ), # loopback
 426                         );
 427                 }
 428                 $n = self::toHex( $ip );
 429                 foreach ( $privateRanges as $r ) {
 430                         $start = self::toHex( $r[0] );
 431                         $end = self::toHex( $r[1] );
 432                         if ( $n >= $start && $n <= $end ) {
 433                                 return false;
 434                         }
 435                 }
 436
 437                 return true;
 438         }
 439
 440         /**
 441          * Return a zero-padded upper case hexadecimal representation of an IP address.
 442          *
 443          * Hexadecimal addresses are used because they can easily be extended to
 444          * IPv6 support. To separate the ranges, the return value from this
 445          * function for an IPv6 address will be prefixed with "v6-", a non-
 446          * hexadecimal string which sorts after the IPv4 addresses.
 447          *
 448          * @param string $ip quad dotted/octet IP address.
 449          * @return String
 450          */
 451         public static function toHex( $ip ) {
 452                 if ( self::isIPv6( $ip ) ) {
 453                         $n = 'v6-' . self::IPv6ToRawHex( $ip );
 454                 } else {
 455                         $n = self::toUnsigned( $ip );
 456                         if ( $n !== false ) {
 457                                 $n = wfBaseConvert( $n, 10, 16, 8, false );
 458                         }
 459                 }
 460
 461                 return $n;
 462         }
 463
 464         /**
 465          * Given an IPv6 address in octet notation, returns a pure hex string.
 466          *
 467          * @param string $ip octet ipv6 IP address.
 468          * @return String: pure hex (uppercase)
 469          */
 470         private static function IPv6ToRawHex( $ip ) {
 471                 $ip = self::sanitizeIP( $ip );
 472                 if ( !$ip ) {
 473                         return null;
 474                 }
 475                 $r_ip = '';
 476                 foreach ( explode( ':', $ip ) as $v ) {
 477                         $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
 478                 }
 479
 480                 return $r_ip;
 481         }
 482
 483         /**
 484          * Given an IP address in dotted-quad/octet notation, returns an unsigned integer.
 485          * Like ip2long() except that it actually works and has a consistent error return value.
 486          *
 487          * @param string $ip quad dotted IP address.
 488          * @return Mixed: string/int/false
 489          */
 490         public static function toUnsigned( $ip ) {
 491                 if ( self::isIPv6( $ip ) ) {
 492                         $n = self::toUnsigned6( $ip );
 493                 } else {
 494                         // Bug 60035: an IP with leading 0's fails in ip2long sometimes (e.g. *.08)
 495                         $ip = preg_replace( '/(?<=\.)0+(?=[1-9])/', '', $ip );
 496                         $n = ip2long( $ip );
 497                         if ( $n < 0 ) {
 498                                 $n += pow( 2, 32 );
 499                                 # On 32-bit platforms (and on Windows), 2^32 does not fit into an int,
 500                                 # so $n becomes a float. We convert it to string instead.
 501                                 if ( is_float( $n ) ) {
 502                                         $n = (string)$n;
 503                                 }
 504                         }
 505                 }
 506
 507                 return $n;
 508         }
 509
 510         /**
 511          * @param $ip
 512          * @return String
 513          */
 514         private static function toUnsigned6( $ip ) {
 515                 return wfBaseConvert( self::IPv6ToRawHex( $ip ), 16, 10 );
 516         }
 517
 518         /**
 519          * Convert a network specification in CIDR notation
 520          * to an integer network and a number of bits
 521          *
 522          * @param string $range IP with CIDR prefix
 523          * @return array(int or string, int)
 524          */
 525         public static function parseCIDR( $range ) {
 526                 if ( self::isIPv6( $range ) ) {
 527                         return self::parseCIDR6( $range );
 528                 }
 529                 $parts = explode( '/', $range, 2 );
 530                 if ( count( $parts ) != 2 ) {
 531                         return array( false, false );
 532                 }
 533                 list( $network, $bits ) = $parts;
 534                 $network = ip2long( $network );
 535                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 536                         if ( $bits == 0 ) {
 537                                 $network = 0;
 538                         } else {
 539                                 $network &= ~( ( 1 << ( 32 - $bits ) ) - 1 );
 540                         }
 541                         # Convert to unsigned
 542                         if ( $network < 0 ) {
 543                                 $network += pow( 2, 32 );
 544                         }
 545                 } else {
 546                         $network = false;
 547                         $bits = false;
 548                 }
 549
 550                 return array( $network, $bits );
 551         }
 552
 553         /**
 554          * Given a string range in a number of formats,
 555          * return the start and end of the range in hexadecimal.
 556          *
 557          * Formats are:
 558          *     1.2.3.4/24          CIDR
 559          *     1.2.3.4 - 1.2.3.5   Explicit range
 560          *     1.2.3.4             Single IP
 561          *
 562          *     2001:0db8:85a3::7344/96                       CIDR
 563          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 564          *     2001:0db8:85a3::7344                          Single IP
 565          * @param string $range IP range
 566          * @return array(string, string)
 567          */
 568         public static function parseRange( $range ) {
 569                 // CIDR notation
 570                 if ( strpos( $range, '/' ) !== false ) {
 571                         if ( self::isIPv6( $range ) ) {
 572                                 return self::parseRange6( $range );
 573                         }
 574                         list( $network, $bits ) = self::parseCIDR( $range );
 575                         if ( $network === false ) {
 576                                 $start = $end = false;
 577                         } else {
 578                                 $start = sprintf( '%08X', $network );
 579                                 $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
 580                         }
 581                 // Explicit range
 582                 } elseif ( strpos( $range, '-' ) !== false ) {
 583                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 584                         if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
 585                                 return self::parseRange6( $range );
 586                         }
 587                         if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
 588                                 $start = self::toUnsigned( $start );
 589                                 $end = self::toUnsigned( $end );
 590                                 if ( $start > $end ) {
 591                                         $start = $end = false;
 592                                 } else {
 593                                         $start = sprintf( '%08X', $start );
 594                                         $end = sprintf( '%08X', $end );
 595                                 }
 596                         } else {
 597                                 $start = $end = false;
 598                         }
 599                 } else {
 600                         # Single IP
 601                         $start = $end = self::toHex( $range );
 602                 }
 603                 if ( $start === false || $end === false ) {
 604                         return array( false, false );
 605                 } else {
 606                         return array( $start, $end );
 607                 }
 608         }
 609
 610         /**
 611          * Convert a network specification in IPv6 CIDR notation to an
 612          * integer network and a number of bits
 613          *
 614          * @param $range
 615          *
 616          * @return array(string, int)
 617          */
 618         private static function parseCIDR6( $range ) {
 619                 # Explode into <expanded IP,range>
 620                 $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
 621                 if ( count( $parts ) != 2 ) {
 622                         return array( false, false );
 623                 }
 624                 list( $network, $bits ) = $parts;
 625                 $network = self::IPv6ToRawHex( $network );
 626                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
 627                         if ( $bits == 0 ) {
 628                                 $network = "0";
 629                         } else {
 630                                 # Native 32 bit functions WONT work here!!!
 631                                 # Convert to a padded binary number
 632                                 $network = wfBaseConvert( $network, 16, 2, 128 );
 633                                 # Truncate the last (128-$bits) bits and replace them with zeros
 634                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 635                                 # Convert back to an integer
 636                                 $network = wfBaseConvert( $network, 2, 10 );
 637                         }
 638                 } else {
 639                         $network = false;
 640                         $bits = false;
 641                 }
 642
 643                 return array( $network, (int)$bits );
 644         }
 645
 646         /**
 647          * Given a string range in a number of formats, return the
 648          * start and end of the range in hexadecimal. For IPv6.
 649          *
 650          * Formats are:
 651          *     2001:0db8:85a3::7344/96                       CIDR
 652          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 653          *     2001:0db8:85a3::7344/96                       Single IP
 654          *
 655          * @param $range
 656          *
 657          * @return array(string, string)
 658          */
 659         private static function parseRange6( $range ) {
 660                 # Expand any IPv6 IP
 661                 $range = IP::sanitizeIP( $range );
 662                 // CIDR notation...
 663                 if ( strpos( $range, '/' ) !== false ) {
 664                         list( $network, $bits ) = self::parseCIDR6( $range );
 665                         if ( $network === false ) {
 666                                 $start = $end = false;
 667                         } else {
 668                                 $start = wfBaseConvert( $network, 10, 16, 32, false );
 669                                 # Turn network to binary (again)
 670                                 $end = wfBaseConvert( $network, 10, 2, 128 );
 671                                 # Truncate the last (128-$bits) bits and replace them with ones
 672                                 $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
 673                                 # Convert to hex
 674                                 $end = wfBaseConvert( $end, 2, 16, 32, false );
 675                                 # see toHex() comment
 676                                 $start = "v6-$start";
 677                                 $end = "v6-$end";
 678                         }
 679         // Explicit range notation...
 680                 } elseif ( strpos( $range, '-' ) !== false ) {
 681                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 682                         $start = self::toUnsigned6( $start );
 683                         $end = self::toUnsigned6( $end );
 684                         if ( $start > $end ) {
 685                                 $start = $end = false;
 686                         } else {
 687                                 $start = wfBaseConvert( $start, 10, 16, 32, false );
 688                                 $end = wfBaseConvert( $end, 10, 16, 32, false );
 689                         }
 690                         # see toHex() comment
 691                         $start = "v6-$start";
 692                         $end = "v6-$end";
 693                 } else {
 694                         # Single IP
 695                         $start = $end = self::toHex( $range );
 696                 }
 697                 if ( $start === false || $end === false ) {
 698                         return array( false, false );
 699                 } else {
 700                         return array( $start, $end );
 701                 }
 702         }
 703
 704         /**
 705          * Determine if a given IPv4/IPv6 address is in a given CIDR network
 706          *
 707          * @param string $addr the address to check against the given range.
 708          * @param string $range the range to check the given address against.
 709          * @return Boolean: whether or not the given address is in the given range.
 710          */
 711         public static function isInRange( $addr, $range ) {
 712                 $hexIP = self::toHex( $addr );
 713                 list( $start, $end ) = self::parseRange( $range );
 714
 715                 return ( strcmp( $hexIP, $start ) >= 0 &&
 716                         strcmp( $hexIP, $end ) <= 0 );
 717         }
 718
 719         /**
 720          * Convert some unusual representations of IPv4 addresses to their
 721          * canonical dotted quad representation.
 722          *
 723          * This currently only checks a few IPV4-to-IPv6 related cases.  More
 724          * unusual representations may be added later.
 725          *
 726          * @param string $addr something that might be an IP address
 727          * @return String: valid dotted quad IPv4 address or null
 728          */
 729         public static function canonicalize( $addr ) {
 730                 // remove zone info (bug 35738)
 731                 $addr = preg_replace( '/\%.*/', '', $addr );
 732
 733                 if ( self::isValid( $addr ) ) {
 734                         return $addr;
 735                 }
 736                 // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
 737                 if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
 738                         $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
 739                         if ( self::isIPv4( $addr ) ) {
 740                                 return $addr;
 741                         }
 742                 }
 743                 // IPv6 loopback address
 744                 $m = array();
 745                 if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) ) {
 746                         return '127.0.0.1';
 747                 }
 748                 // IPv4-mapped and IPv4-compatible IPv6 addresses
 749                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) ) {
 750                         return $m[1];
 751                 }
 752                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD .
 753                         ':' . RE_IPV6_WORD . '$/i', $addr, $m )
 754                 ) {
 755                         return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 756                 }
 757
 758                 return null; // give up
 759         }
 760
 761         /**
 762          * Gets rid of unneeded numbers in quad-dotted/octet IP strings
 763          * For example, 127.111.113.151/24 -> 127.111.113.0/24
 764          * @param string $range IP address to normalize
 765          * @return string
 766          */
 767         public static function sanitizeRange( $range ) {
 768                 list( /*...*/, $bits ) = self::parseCIDR( $range );
 769                 list( $start, /*...*/ ) = self::parseRange( $range );
 770                 $start = self::formatHex( $start );
 771                 if ( $bits === false ) {
 772                         return $start; // wasn't actually a range
 773                 }
 774
 775                 return "$start/$bits";
 776         }
 777
 778         /**
 779          * Checks if an IP is a trusted proxy provider.
 780          * Useful to tell if X-Forwarded-For data is possibly bogus.
 781          * Squid cache servers for the site are whitelisted.
 782          * @since 1.24
 783          *
 784          * @param string $ip
 785          * @return bool
 786          */
 787         public static function isTrustedProxy( $ip ) {
 788                 $trusted = self::isConfiguredProxy( $ip );
 789                 wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
 790                 return $trusted;
 791         }
 792
 793         /**
 794          * Checks if an IP matches a proxy we've configured
 795          * @since 1.24
 796          *
 797          * @param string $ip
 798          * @return bool
 799          */
 800         public static function isConfiguredProxy( $ip ) {
 801                 global $wgSquidServers, $wgSquidServersNoPurge;
 802
 803                 wfProfileIn( __METHOD__ );
 804                 // Quick check of known singular proxy servers
 805                 $trusted = in_array( $ip, $wgSquidServers );
 806
 807                 // Check against addresses and CIDR nets in the NoPurge list
 808                 if ( !$trusted ) {
 809                         if ( !self::$ipSet ) {
 810                                 self::$ipSet = new IPSet( $wgSquidServersNoPurge );
 811                         }
 812                         $trusted = self::$ipSet->match( $ip );
 813                 }
 814                 wfProfileOut( __METHOD__ );
 815                 return $trusted;
 816         }
 817
 818         /**
 819          * Clears precomputed data used for proxy support.
 820          * Use this only for unit tests.
 821          */
 822         public static function clearCaches() {
 823                 self::$ipSet = null;
 824         }
 825 }