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 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 IPv6 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          * IPv6 addresses in octet notation are expanded to 8 words.
 136          * IPv4 addresses are just trimmed.
 137          *
 138          * @param string $ip IP address in quad or octet form (CIDR or not).
 139          * @return string
 140          */
 141         public static function sanitizeIP( $ip ) {
 142                 $ip = trim( $ip );
 143                 if ( $ip === '' ) {
 144                         return null;
 145                 }
 146                 if ( self::isIPv4( $ip ) || !self::isIPv6( $ip ) ) {
 147                         return $ip; // nothing else to do for IPv4 addresses or invalid ones
 148                 }
 149                 // Remove any whitespaces, convert to upper case
 150                 $ip = strtoupper( $ip );
 151                 // Expand zero abbreviations
 152                 $abbrevPos = strpos( $ip, '::' );
 153                 if ( $abbrevPos !== false ) {
 154                         // We know this is valid IPv6. Find the last index of the
 155                         // address before any CIDR number (e.g. "a:b:c::/24").
 156                         $CIDRStart = strpos( $ip, "/" );
 157                         $addressEnd = ( $CIDRStart !== false )
 158                                 ? $CIDRStart - 1
 159                                 : strlen( $ip ) - 1;
 160                         // If the '::' is at the beginning...
 161                         if ( $abbrevPos == 0 ) {
 162                                 $repeat = '0:';
 163                                 $extra = ( $ip == '::' ) ? '0' : ''; // for the address '::'
 164                                 $pad = 9; // 7+2 (due to '::')
 165                         // If the '::' is at the end...
 166                         } elseif ( $abbrevPos == ( $addressEnd - 1 ) ) {
 167                                 $repeat = ':0';
 168                                 $extra = '';
 169                                 $pad = 9; // 7+2 (due to '::')
 170                         // If the '::' is in the middle...
 171                         } else {
 172                                 $repeat = ':0';
 173                                 $extra = ':';
 174                                 $pad = 8; // 6+2 (due to '::')
 175                         }
 176                         $ip = str_replace( '::',
 177                                 str_repeat( $repeat, $pad - substr_count( $ip, ':' ) ) . $extra,
 178                                 $ip
 179                         );
 180                 }
 181                 // Remove leading zeros from each bloc as needed
 182                 $ip = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip );
 183
 184                 return $ip;
 185         }
 186
 187         /**
 188          * Prettify an IP for display to end users.
 189          * This will make it more compact and lower-case.
 190          *
 191          * @param string $ip
 192          * @return string
 193          */
 194         public static function prettifyIP( $ip ) {
 195                 $ip = self::sanitizeIP( $ip ); // normalize (removes '::')
 196                 if ( self::isIPv6( $ip ) ) {
 197                         // Split IP into an address and a CIDR
 198                         if ( strpos( $ip, '/' ) !== false ) {
 199                                 list( $ip, $cidr ) = explode( '/', $ip, 2 );
 200                         } else {
 201                                 list( $ip, $cidr ) = array( $ip, '' );
 202                         }
 203                         // Get the largest slice of words with multiple zeros
 204                         $offset = 0;
 205                         $longest = $longestPos = false;
 206                         while ( preg_match(
 207                                 '!(?:^|:)0(?::0)+(?:$|:)!', $ip, $m, PREG_OFFSET_CAPTURE, $offset
 208                         ) ) {
 209                                 list( $match, $pos ) = $m[0]; // full match
 210                                 if ( strlen( $match ) > strlen( $longest ) ) {
 211                                         $longest = $match;
 212                                         $longestPos = $pos;
 213                                 }
 214                                 $offset = ( $pos + strlen( $match ) ); // advance
 215                         }
 216                         if ( $longest !== false ) {
 217                                 // Replace this portion of the string with the '::' abbreviation
 218                                 $ip = substr_replace( $ip, '::', $longestPos, strlen( $longest ) );
 219                         }
 220                         // Add any CIDR back on
 221                         if ( $cidr !== '' ) {
 222                                 $ip = "{$ip}/{$cidr}";
 223                         }
 224                         // Convert to lower case to make it more readable
 225                         $ip = strtolower( $ip );
 226                 }
 227
 228                 return $ip;
 229         }
 230
 231         /**
 232          * Given a host/port string, like one might find in the host part of a URL
 233          * per RFC 2732, split the hostname part and the port part and return an
 234          * array with an element for each. If there is no port part, the array will
 235          * have false in place of the port. If the string was invalid in some way,
 236          * false is returned.
 237          *
 238          * This was easy with IPv4 and was generally done in an ad-hoc way, but
 239          * with IPv6 it's somewhat more complicated due to the need to parse the
 240          * square brackets and colons.
 241          *
 242          * A bare IPv6 address is accepted despite the lack of square brackets.
 243          *
 244          * @param string $both The string with the host and port
 245          * @return array|false Array normally, false on certain failures
 246          */
 247         public static function splitHostAndPort( $both ) {
 248                 if ( substr( $both, 0, 1 ) === '[' ) {
 249                         if ( preg_match( '/^\[(' . RE_IPV6_ADD . ')\](?::(?P<port>\d+))?$/', $both, $m ) ) {
 250                                 if ( isset( $m['port'] ) ) {
 251                                         return array( $m[1], intval( $m['port'] ) );
 252                                 } else {
 253                                         return array( $m[1], false );
 254                                 }
 255                         } else {
 256                                 // Square bracket found but no IPv6
 257                                 return false;
 258                         }
 259                 }
 260                 $numColons = substr_count( $both, ':' );
 261                 if ( $numColons >= 2 ) {
 262                         // Is it a bare IPv6 address?
 263                         if ( preg_match( '/^' . RE_IPV6_ADD . '$/', $both ) ) {
 264                                 return array( $both, false );
 265                         } else {
 266                                 // Not valid IPv6, but too many colons for anything else
 267                                 return false;
 268                         }
 269                 }
 270                 if ( $numColons >= 1 ) {
 271                         // Host:port?
 272                         $bits = explode( ':', $both );
 273                         if ( preg_match( '/^\d+/', $bits[1] ) ) {
 274                                 return array( $bits[0], intval( $bits[1] ) );
 275                         } else {
 276                                 // Not a valid port
 277                                 return false;
 278                         }
 279                 }
 280
 281                 // Plain hostname
 282                 return array( $both, false );
 283         }
 284
 285         /**
 286          * Given a host name and a port, combine them into host/port string like
 287          * you might find in a URL. If the host contains a colon, wrap it in square
 288          * brackets like in RFC 2732. If the port matches the default port, omit
 289          * the port specification
 290          *
 291          * @param string $host
 292          * @param int $port
 293          * @param bool|int $defaultPort
 294          * @return string
 295          */
 296         public static function combineHostAndPort( $host, $port, $defaultPort = false ) {
 297                 if ( strpos( $host, ':' ) !== false ) {
 298                         $host = "[$host]";
 299                 }
 300                 if ( $defaultPort !== false && $port == $defaultPort ) {
 301                         return $host;
 302                 } else {
 303                         return "$host:$port";
 304                 }
 305         }
 306
 307         /**
 308          * Convert an IPv4 or IPv6 hexadecimal representation back to readable format
 309          *
 310          * @param string $hex Number, with "v6-" prefix if it is IPv6
 311          * @return string Quad-dotted (IPv4) or octet notation (IPv6)
 312          */
 313         public static function formatHex( $hex ) {
 314                 if ( substr( $hex, 0, 3 ) == 'v6-' ) { // IPv6
 315                         return self::hexToOctet( substr( $hex, 3 ) );
 316                 } else { // IPv4
 317                         return self::hexToQuad( $hex );
 318                 }
 319         }
 320
 321         /**
 322          * Converts a hexadecimal number to an IPv6 address in octet notation
 323          *
 324          * @param string $ip_hex Pure hex (no v6- prefix)
 325          * @return string (of format a:b:c:d:e:f:g:h)
 326          */
 327         public static function hexToOctet( $ip_hex ) {
 328                 // Pad hex to 32 chars (128 bits)
 329                 $ip_hex = str_pad( strtoupper( $ip_hex ), 32, '0', STR_PAD_LEFT );
 330                 // Separate into 8 words
 331                 $ip_oct = substr( $ip_hex, 0, 4 );
 332                 for ( $n = 1; $n < 8; $n++ ) {
 333                         $ip_oct .= ':' . substr( $ip_hex, 4 * $n, 4 );
 334                 }
 335                 // NO leading zeroes
 336                 $ip_oct = preg_replace( '/(^|:)0+(' . RE_IPV6_WORD . ')/', '$1$2', $ip_oct );
 337
 338                 return $ip_oct;
 339         }
 340
 341         /**
 342          * Converts a hexadecimal number to an IPv4 address in quad-dotted notation
 343          *
 344          * @param string $ip_hex Pure hex
 345          * @return string (of format a.b.c.d)
 346          */
 347         public static function hexToQuad( $ip_hex ) {
 348                 // Pad hex to 8 chars (32 bits)
 349                 $ip_hex = str_pad( strtoupper( $ip_hex ), 8, '0', STR_PAD_LEFT );
 350                 // Separate into four quads
 351                 $s = '';
 352                 for ( $i = 0; $i < 4; $i++ ) {
 353                         if ( $s !== '' ) {
 354                                 $s .= '.';
 355                         }
 356                         $s .= base_convert( substr( $ip_hex, $i * 2, 2 ), 16, 10 );
 357                 }
 358
 359                 return $s;
 360         }
 361
 362         /**
 363          * Determine if an IP address really is an IP address, and if it is public,
 364          * i.e. not RFC 1918 or similar
 365          *
 366          * @param string $ip
 367          * @return bool
 368          */
 369         public static function isPublic( $ip ) {
 370                 static $privateSet = null;
 371                 if ( !$privateSet ) {
 372                         $privateSet = new IPSet( array(
 373                                 '10.0.0.0/8', # RFC 1918 (private)
 374                                 '172.16.0.0/12', # RFC 1918 (private)
 375                                 '192.168.0.0/16', # RFC 1918 (private)
 376                                 '0.0.0.0/8', # this network
 377                                 '127.0.0.0/8', # loopback
 378                                 'fc00::/7', # RFC 4193 (local)
 379                                 '0:0:0:0:0:0:0:1', # loopback
 380                                 '169.254.0.0/16', # link-local
 381                                 'fe80::/10', # link-local
 382                         ) );
 383                 }
 384                 return !$privateSet->match( $ip );
 385         }
 386
 387         /**
 388          * Return a zero-padded upper case hexadecimal representation of an IP address.
 389          *
 390          * Hexadecimal addresses are used because they can easily be extended to
 391          * IPv6 support. To separate the ranges, the return value from this
 392          * function for an IPv6 address will be prefixed with "v6-", a non-
 393          * hexadecimal string which sorts after the IPv4 addresses.
 394          *
 395          * @param string $ip Quad dotted/octet IP address.
 396          * @return string|bool False on failure
 397          */
 398         public static function toHex( $ip ) {
 399                 if ( self::isIPv6( $ip ) ) {
 400                         $n = 'v6-' . self::IPv6ToRawHex( $ip );
 401                 } elseif ( self::isIPv4( $ip ) ) {
 402                         // Bug 60035: an IP with leading 0's fails in ip2long sometimes (e.g. *.08)
 403                         $ip = preg_replace( '/(?<=\.)0+(?=[1-9])/', '', $ip );
 404                         $n = ip2long( $ip );
 405                         if ( $n < 0 ) {
 406                                 $n += pow( 2, 32 );
 407                                 # On 32-bit platforms (and on Windows), 2^32 does not fit into an int,
 408                                 # so $n becomes a float. We convert it to string instead.
 409                                 if ( is_float( $n ) ) {
 410                                         $n = (string)$n;
 411                                 }
 412                         }
 413                         if ( $n !== false ) {
 414                                 # Floating points can handle the conversion; faster than wfBaseConvert()
 415                                 $n = strtoupper( str_pad( base_convert( $n, 10, 16 ), 8, '0', STR_PAD_LEFT ) );
 416                         }
 417                 } else {
 418                         $n = false;
 419                 }
 420
 421                 return $n;
 422         }
 423
 424         /**
 425          * Given an IPv6 address in octet notation, returns a pure hex string.
 426          *
 427          * @param string $ip Octet ipv6 IP address.
 428          * @return string|bool Pure hex (uppercase); false on failure
 429          */
 430         private static function IPv6ToRawHex( $ip ) {
 431                 $ip = self::sanitizeIP( $ip );
 432                 if ( !$ip ) {
 433                         return false;
 434                 }
 435                 $r_ip = '';
 436                 foreach ( explode( ':', $ip ) as $v ) {
 437                         $r_ip .= str_pad( $v, 4, 0, STR_PAD_LEFT );
 438                 }
 439
 440                 return $r_ip;
 441         }
 442
 443         /**
 444          * Convert a network specification in CIDR notation
 445          * to an integer network and a number of bits
 446          *
 447          * @param string $range IP with CIDR prefix
 448          * @return array(int or string, int)
 449          */
 450         public static function parseCIDR( $range ) {
 451                 if ( self::isIPv6( $range ) ) {
 452                         return self::parseCIDR6( $range );
 453                 }
 454                 $parts = explode( '/', $range, 2 );
 455                 if ( count( $parts ) != 2 ) {
 456                         return array( false, false );
 457                 }
 458                 list( $network, $bits ) = $parts;
 459                 $network = ip2long( $network );
 460                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 32 ) {
 461                         if ( $bits == 0 ) {
 462                                 $network = 0;
 463                         } else {
 464                                 $network &= ~( ( 1 << ( 32 - $bits ) ) - 1 );
 465                         }
 466                         # Convert to unsigned
 467                         if ( $network < 0 ) {
 468                                 $network += pow( 2, 32 );
 469                         }
 470                 } else {
 471                         $network = false;
 472                         $bits = false;
 473                 }
 474
 475                 return array( $network, $bits );
 476         }
 477
 478         /**
 479          * Given a string range in a number of formats,
 480          * return the start and end of the range in hexadecimal.
 481          *
 482          * Formats are:
 483          *     1.2.3.4/24          CIDR
 484          *     1.2.3.4 - 1.2.3.5   Explicit range
 485          *     1.2.3.4             Single IP
 486          *
 487          *     2001:0db8:85a3::7344/96                       CIDR
 488          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 489          *     2001:0db8:85a3::7344                          Single IP
 490          * @param string $range IP range
 491          * @return array(string, string)
 492          */
 493         public static function parseRange( $range ) {
 494                 // CIDR notation
 495                 if ( strpos( $range, '/' ) !== false ) {
 496                         if ( self::isIPv6( $range ) ) {
 497                                 return self::parseRange6( $range );
 498                         }
 499                         list( $network, $bits ) = self::parseCIDR( $range );
 500                         if ( $network === false ) {
 501                                 $start = $end = false;
 502                         } else {
 503                                 $start = sprintf( '%08X', $network );
 504                                 $end = sprintf( '%08X', $network + pow( 2, ( 32 - $bits ) ) - 1 );
 505                         }
 506                 // Explicit range
 507                 } elseif ( strpos( $range, '-' ) !== false ) {
 508                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 509                         if ( self::isIPv6( $start ) && self::isIPv6( $end ) ) {
 510                                 return self::parseRange6( $range );
 511                         }
 512                         if ( self::isIPv4( $start ) && self::isIPv4( $end ) ) {
 513                                 $start = self::toHex( $start );
 514                                 $end = self::toHex( $end );
 515                                 if ( $start > $end ) {
 516                                         $start = $end = false;
 517                                 }
 518                         } else {
 519                                 $start = $end = false;
 520                         }
 521                 } else {
 522                         # Single IP
 523                         $start = $end = self::toHex( $range );
 524                 }
 525                 if ( $start === false || $end === false ) {
 526                         return array( false, false );
 527                 } else {
 528                         return array( $start, $end );
 529                 }
 530         }
 531
 532         /**
 533          * Convert a network specification in IPv6 CIDR notation to an
 534          * integer network and a number of bits
 535          *
 536          * @param string $range
 537          *
 538          * @return array(string, int)
 539          */
 540         private static function parseCIDR6( $range ) {
 541                 # Explode into <expanded IP,range>
 542                 $parts = explode( '/', IP::sanitizeIP( $range ), 2 );
 543                 if ( count( $parts ) != 2 ) {
 544                         return array( false, false );
 545                 }
 546                 list( $network, $bits ) = $parts;
 547                 $network = self::IPv6ToRawHex( $network );
 548                 if ( $network !== false && is_numeric( $bits ) && $bits >= 0 && $bits <= 128 ) {
 549                         if ( $bits == 0 ) {
 550                                 $network = "0";
 551                         } else {
 552                                 # Native 32 bit functions WONT work here!!!
 553                                 # Convert to a padded binary number
 554                                 $network = wfBaseConvert( $network, 16, 2, 128 );
 555                                 # Truncate the last (128-$bits) bits and replace them with zeros
 556                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 557                                 # Convert back to an integer
 558                                 $network = wfBaseConvert( $network, 2, 10 );
 559                         }
 560                 } else {
 561                         $network = false;
 562                         $bits = false;
 563                 }
 564
 565                 return array( $network, (int)$bits );
 566         }
 567
 568         /**
 569          * Given a string range in a number of formats, return the
 570          * start and end of the range in hexadecimal. For IPv6.
 571          *
 572          * Formats are:
 573          *     2001:0db8:85a3::7344/96                       CIDR
 574          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 575          *     2001:0db8:85a3::7344/96                       Single IP
 576          *
 577          * @param string $range
 578          *
 579          * @return array(string, string)
 580          */
 581         private static function parseRange6( $range ) {
 582                 # Expand any IPv6 IP
 583                 $range = IP::sanitizeIP( $range );
 584                 // CIDR notation...
 585                 if ( strpos( $range, '/' ) !== false ) {
 586                         list( $network, $bits ) = self::parseCIDR6( $range );
 587                         if ( $network === false ) {
 588                                 $start = $end = false;
 589                         } else {
 590                                 $start = wfBaseConvert( $network, 10, 16, 32, false );
 591                                 # Turn network to binary (again)
 592                                 $end = wfBaseConvert( $network, 10, 2, 128 );
 593                                 # Truncate the last (128-$bits) bits and replace them with ones
 594                                 $end = str_pad( substr( $end, 0, $bits ), 128, 1, STR_PAD_RIGHT );
 595                                 # Convert to hex
 596                                 $end = wfBaseConvert( $end, 2, 16, 32, false );
 597                                 # see toHex() comment
 598                                 $start = "v6-$start";
 599                                 $end = "v6-$end";
 600                         }
 601                 // Explicit range notation...
 602                 } elseif ( strpos( $range, '-' ) !== false ) {
 603                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 604                         $start = self::toHex( $start );
 605                         $end = self::toHex( $end );
 606                         if ( $start > $end ) {
 607                                 $start = $end = false;
 608                         }
 609                 } else {
 610                         # Single IP
 611                         $start = $end = self::toHex( $range );
 612                 }
 613                 if ( $start === false || $end === false ) {
 614                         return array( false, false );
 615                 } else {
 616                         return array( $start, $end );
 617                 }
 618         }
 619
 620         /**
 621          * Determine if a given IPv4/IPv6 address is in a given CIDR network
 622          *
 623          * @param string $addr The address to check against the given range.
 624          * @param string $range The range to check the given address against.
 625          * @return bool Whether or not the given address is in the given range.
 626          */
 627         public static function isInRange( $addr, $range ) {
 628                 $hexIP = self::toHex( $addr );
 629                 list( $start, $end ) = self::parseRange( $range );
 630
 631                 return ( strcmp( $hexIP, $start ) >= 0 &&
 632                         strcmp( $hexIP, $end ) <= 0 );
 633         }
 634
 635         /**
 636          * Determines if an IP address is a list of CIDR a.b.c.d/n ranges.
 637          *
 638          * @since 1.25
 639          *
 640          * @param string $ip the IP to check
 641          * @param array $ranges the IP ranges, each element a range
 642          *
 643          * @return bool true if the specified adress belongs to the specified range; otherwise, false.
 644          */
 645         public static function isInRanges( $ip, $ranges ) {
 646                 foreach ( $ranges as $range ) {
 647                         if ( self::isInRange( $ip, $range ) ) {
 648                                 return true;
 649                         }
 650                 }
 651                 return false;
 652         }
 653
 654         /**
 655          * Convert some unusual representations of IPv4 addresses to their
 656          * canonical dotted quad representation.
 657          *
 658          * This currently only checks a few IPV4-to-IPv6 related cases.  More
 659          * unusual representations may be added later.
 660          *
 661          * @param string $addr Something that might be an IP address
 662          * @return string Valid dotted quad IPv4 address or null
 663          */
 664         public static function canonicalize( $addr ) {
 665                 // remove zone info (bug 35738)
 666                 $addr = preg_replace( '/\%.*/', '', $addr );
 667
 668                 if ( self::isValid( $addr ) ) {
 669                         return $addr;
 670                 }
 671                 // Turn mapped addresses from ::ce:ffff:1.2.3.4 to 1.2.3.4
 672                 if ( strpos( $addr, ':' ) !== false && strpos( $addr, '.' ) !== false ) {
 673                         $addr = substr( $addr, strrpos( $addr, ':' ) + 1 );
 674                         if ( self::isIPv4( $addr ) ) {
 675                                 return $addr;
 676                         }
 677                 }
 678                 // IPv6 loopback address
 679                 $m = array();
 680                 if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) ) {
 681                         return '127.0.0.1';
 682                 }
 683                 // IPv4-mapped and IPv4-compatible IPv6 addresses
 684                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) ) {
 685                         return $m[1];
 686                 }
 687                 if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD .
 688                         ':' . RE_IPV6_WORD . '$/i', $addr, $m )
 689                 ) {
 690                         return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 691                 }
 692
 693                 return null; // give up
 694         }
 695
 696         /**
 697          * Gets rid of unneeded numbers in quad-dotted/octet IP strings
 698          * For example, 127.111.113.151/24 -> 127.111.113.0/24
 699          * @param string $range IP address to normalize
 700          * @return string
 701          */
 702         public static function sanitizeRange( $range ) {
 703                 list( /*...*/, $bits ) = self::parseCIDR( $range );
 704                 list( $start, /*...*/ ) = self::parseRange( $range );
 705                 $start = self::formatHex( $start );
 706                 if ( $bits === false ) {
 707                         return $start; // wasn't actually a range
 708                 }
 709
 710                 return "$start/$bits";
 711         }
 712
 713         /**
 714          * Checks if an IP is a trusted proxy provider.
 715          * Useful to tell if X-Forwarded-For data is possibly bogus.
 716          * Squid cache servers for the site are whitelisted.
 717          * @since 1.24
 718          *
 719          * @param string $ip
 720          * @return bool
 721          */
 722         public static function isTrustedProxy( $ip ) {
 723                 $trusted = self::isConfiguredProxy( $ip );
 724                 Hooks::run( 'IsTrustedProxy', array( &$ip, &$trusted ) );
 725                 return $trusted;
 726         }
 727
 728         /**
 729          * Checks if an IP matches a proxy we've configured
 730          * @since 1.24
 731          *
 732          * @param string $ip
 733          * @return bool
 734          */
 735         public static function isConfiguredProxy( $ip ) {
 736                 global $wgSquidServers, $wgSquidServersNoPurge;
 737
 738                 // Quick check of known singular proxy servers
 739                 $trusted = in_array( $ip, $wgSquidServers );
 740
 741                 // Check against addresses and CIDR nets in the NoPurge list
 742                 if ( !$trusted ) {
 743                         if ( !self::$proxyIpSet ) {
 744                                 self::$proxyIpSet = new IPSet( $wgSquidServersNoPurge );
 745                         }
 746                         $trusted = self::$proxyIpSet->match( $ip );
 747                 }
 748
 749                 return $trusted;
 750         }
 751
 752         /**
 753          * Clears precomputed data used for proxy support.
 754          * Use this only for unit tests.
 755          */
 756         public static function clearCaches() {
 757                 self::$proxyIpSet = null;
 758         }
 759 }