includes/IP.php

   1 <?php
   2 /*
   3  * Collection of public static functions to play with IP address
   4  * and IP blocks.
   5  *
   6  * @Author "Ashar Voultoiz" <hashar@altern.org>
   7  * @License GPL v2 or later
   8  */
   9
  10 // Some regex definition to "play" with IP address and IP address blocks
  11
  12 // An IP is made of 4 bytes from x00 to xFF which is d0 to d255
  13 define( 'RE_IP_BYTE', '(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|0?[0-9]?[0-9])');
  14 define( 'RE_IP_ADD' , RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE . '\.' . RE_IP_BYTE );
  15 // An IP block is an IP address and a prefix (d1 to d32)
  16 define( 'RE_IP_PREFIX', '(3[0-2]|[12]?\d)');
  17 define( 'RE_IP_BLOCK', RE_IP_ADD . '\/' . RE_IP_PREFIX);
  18 // For IPv6 canonicalization (NOT for strict validation; these are quite lax!)
  19 define( 'RE_IPV6_WORD', '([0-9A-Fa-f]{1,4})' );
  20 define( 'RE_IPV6_GAP', ':(?:0+:)*(?::(?:0+:)*)?' );
  21 define( 'RE_IPV6_V4_PREFIX', '0*' . RE_IPV6_GAP . '(?:ffff:)?' );
  22 // An IPv6 IP is made up of 8 octeds. However abbreviations like "::" can be used. This is lax!
  23 define( 'RE_IPV6_ADD', RE_IPV6_WORD . '(::$|' . RE_IPV6_GAP . RE_IPV6_WORD . '){1,7}' );
  24
  25 class IP {
  26
  27         /**
  28          * Given an IP address in dotted-quad notation, returns an IPv6 octet.
  29          * See http://www.answers.com/topic/ipv4-compatible-address
  30          * IPs with the first 92 bits as zeros are reserved from IPv6
  31          * @param $ip quad-dotted IP address.
  32          * @return string
  33          */
  34         public function IPv4toIPv6( $ip ) {
  35                 if ( !$ip ) return null;
  36                 // Convert only if needed
  37                 if ( strpos($ip,':') !==false ) return $ip;
  38                 // IPv4 CIDRs
  39                 if ( strpos( $ip, '/' ) !== false ) {
  40                         $parts = explode( '/', $ip, 2 );
  41                         if ( count( $parts ) != 2 ) {
  42                                 return false;
  43                         }
  44                         $network = IP::toUnsigned( $parts[0] );
  45                         $bits = $parts[1] + 96;
  46                         if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
  47                                 return IP::toOctet( $network ) . "/$bits";
  48                         } else {
  49                                 return false;
  50                         }
  51                 }
  52                 return IP::toOctet( IP::toUnsigned( $ip ) );
  53         }
  54
  55         /**
  56          * Given an IPv6 address in octet notation, returns an unsigned integer.
  57          * @param $ip octet ipv6 IP address.
  58          * @return string
  59          */
  60         public function toUnsigned6( $ip ) {
  61                 if ( !$ip ) return null;
  62         $ip = explode(':', IP::expandIPv6( $ip ) );
  63         $r_ip = '';
  64         foreach ($ip as $v) {
  65                 $r_ip .= wfBaseConvert( $v, 16, 2, 16);
  66         }
  67         return wfBaseConvert($r_ip, 2, 10);
  68         }
  69
  70         /**
  71          * Given an IPv6 address in octet notation, returns the expanded octet.
  72          * @param $ip octet ipv6 IP address.
  73          * @return string
  74          */
  75         public function expandIPv6( $ip ) {
  76                 if ( !$ip ) return null;
  77                 // Expand zero abbreviations
  78                 if ( substr_count($ip, '::') ) {
  79                 $ip = str_replace('::', str_repeat(':0000', 8 - substr_count($ip, ':')) . ':', $ip);
  80         }
  81         return $ip;
  82         }
  83
  84         /**
  85          * Given an unsigned integer, returns an IPv6 address in octet notation
  86          * @param $ip integer ipv6 IP address.
  87          * @return string
  88          */
  89         public function toOctet( $ip_int ) {
  90                 // Convert integer to binary
  91                 $ip_int = wfBaseConvert($ip_int, 10, 2, 128);
  92                 // Seperate into 8 octets
  93                 $ip_oct = base_convert( substr( $ip_int, 0, 16 ), 2, 16 );
  94                 for ($n=1; $n < 8; $n++) {
  95                         // Convert to hex, and add ":" marks
  96                         $ip_oct .= ':' . base_convert( substr($ip_int, 16*$n, 16), 2, 16 );
  97                 }
  98         return $ip_oct;
  99         }
 100
 101         /**
 102          * Convert a network specification in IPv6 CIDR notation to an integer network and a number of bits
 103          * @return array(string, int)
 104          */
 105         public static function parseCIDR6( $range ) {
 106                 $parts = explode( '/', $range, 2 );
 107                 if ( count( $parts ) != 2 ) {
 108                         return array( false, false );
 109                 }
 110                 $network = IP::toUnsigned6( $parts[0] );
 111                 if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 128 ) {
 112                         $bits = $parts[1];
 113                         if ( $bits == 0 ) {
 114                                 $network = 0;
 115                         } else {
 116                         # Native 32 bit functions WONT work here!!!
 117                         # Convert to a padded binary number
 118                                 $network = wfBaseConvert( $network, 10, 2, 128 );
 119                         # Truncate the last (128-$bits) bits and replace them with zeros
 120                                 $network = str_pad( substr( $network, 0, (128 - $bits) ), 128, 0, STR_PAD_RIGHT );
 121                         # Convert back to an integer
 122                                 $network = wfBaseConvert( $network, 2, 10 );
 123                         }
 124                 } else {
 125                         $network = false;
 126                         $bits = false;
 127                 }
 128
 129                 return array( $network, $bits );
 130         }
 131
 132         /**
 133          * Given a string range in a number of formats, return the start and end of
 134          * the range in hexadecimal. For IPv6.
 135          *
 136          * Formats are:
 137          *     2001:0db8:85a3::7344/96                                   CIDR
 138          *     2001:0db8:85a3::7344 - 2001:0db8:85a3::7344   Explicit range
 139          *     2001:0db8:85a3::7344/96                                   Single IP
 140          * @return array(string, int)
 141          */
 142         public static function parseRange6( $range ) {
 143                 if ( strpos( $range, '/' ) !== false ) {
 144                         # CIDR
 145                         list( $network, $bits ) = IP::parseCIDR6( $range );
 146                         if ( $network === false ) {
 147                                 $start = $end = false;
 148                         } else {
 149                                 $start = sprintf( '%08X', $network );
 150                                 $end = sprintf( '%08X', $network + pow( 2, (128 - $bits) ) - 1 );
 151                         }
 152                 } elseif ( strpos( $range, '-' ) !== false ) {
 153                         # Explicit range
 154                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 155                         $start = IP::toUnsigned6( $start ); $end = IP::toUnsigned6( $end );
 156                         if ( $start > $end ) {
 157                                 $start = $end = false;
 158                         } else {
 159                                 $start = sprintf( '%08X', $start );
 160                                 $end = sprintf( '%08X', $end );
 161                         }
 162                 } else {
 163                         # Single IP
 164                         $start = $end = IP::toHex6( $range );
 165                 }
 166                 if ( $start === false || $end === false ) {
 167                         return array( false, false );
 168                 } else {
 169                         return array( $start, $end );
 170                 }
 171     }
 172
 173         /**
 174          * Validate an IP address.
 175          * @return boolean True if it is valid.
 176          */
 177         public static function isValid( $ip ) {
 178                 return preg_match( '/^' . RE_IP_ADD . '$/', $ip);
 179         }
 180
 181         /**
 182          * Validate an IP Block.
 183          * @return boolean True if it is valid.
 184          */
 185         public static function isValidBlock( $ipblock ) {
 186                 return ( count(self::toArray($ipblock)) == 1 + 5 );
 187         }
 188
 189         /**
 190          * Determine if an IP address really is an IP address, and if it is public,
 191          * i.e. not RFC 1918 or similar
 192          * Comes from ProxyTools.php
 193          */
 194         public static function isPublic( $ip ) {
 195                 $n = IP::toUnsigned( $ip );
 196                 if ( !$n ) {
 197                         return false;
 198                 }
 199
 200                 // ip2long accepts incomplete addresses, as well as some addresses
 201                 // followed by garbage characters. Check that it's really valid.
 202                 if( $ip != long2ip( $n ) ) {
 203                         return false;
 204                 }
 205
 206                 static $privateRanges = false;
 207                 if ( !$privateRanges ) {
 208                         $privateRanges = array(
 209                                 array( '10.0.0.0',    '10.255.255.255' ),   # RFC 1918 (private)
 210                                 array( '172.16.0.0',  '172.31.255.255' ),   #     "
 211                                 array( '192.168.0.0', '192.168.255.255' ),  #     "
 212                                 array( '0.0.0.0',     '0.255.255.255' ),    # this network
 213                                 array( '127.0.0.0',   '127.255.255.255' ),  # loopback
 214                         );
 215                 }
 216
 217                 foreach ( $privateRanges as $r ) {
 218                         $start = IP::toUnsigned( $r[0] );
 219                         $end = IP::toUnsigned( $r[1] );
 220                         if ( $n >= $start && $n <= $end ) {
 221                                 return false;
 222                         }
 223                 }
 224                 return true;
 225         }
 226
 227         /**
 228          * Split out an IP block as an array of 4 bytes and a mask,
 229          * return false if it can't be determined
 230          *
 231          * @parameter $ip string A quad dotted IP address
 232          * @return array
 233          */
 234         public static function toArray( $ipblock ) {
 235                 $matches = array();
 236                 if(! preg_match( '/^' . RE_IP_ADD . '(?:\/(?:'.RE_IP_PREFIX.'))?' . '$/', $ipblock, $matches ) ) {
 237                         return false;
 238                 } else {
 239                         return $matches;
 240                 }
 241         }
 242
 243         /**
 244          * Return a zero-padded hexadecimal representation of an IP address.
 245          *
 246          * Hexadecimal addresses are used because they can easily be extended to
 247          * IPv6 support. To separate the ranges, the return value from this
 248          * function for an IPv6 address will be prefixed with "v6-", a non-
 249          * hexadecimal string which sorts after the IPv4 addresses.
 250          *
 251          * @param $ip Quad dotted IP address.
 252          * @return hexidecimal
 253          */
 254         public static function toHex( $ip ) {
 255                 $n = self::toUnsigned( $ip );
 256                 if ( $n !== false ) {
 257                         $n = sprintf( '%08X', $n );
 258                 }
 259                 return $n;
 260         }
 261
 262         // For IPv6
 263         public static function toHex6( $ip ) {
 264                 $n = self::toUnsigned6( $ip );
 265                 if ( $n !== false ) {
 266                         $n = sprintf( '%08X', $n );
 267                 }
 268                 return $n;
 269         }
 270
 271         /**
 272          * Given an IP address in dotted-quad notation, returns an unsigned integer.
 273          * Like ip2long() except that it actually works and has a consistent error return value.
 274          * Comes from ProxyTools.php
 275          * @param $ip Quad dotted IP address.
 276          * @return integer
 277          */
 278         public static function toUnsigned( $ip ) {
 279                 if ( $ip == '255.255.255.255' ) {
 280                         $n = -1;
 281                 } else {
 282                         $n = ip2long( $ip );
 283                         if ( $n == -1 || $n === false ) { # Return value on error depends on PHP version
 284                                 $n = false;
 285                         }
 286                 }
 287                 if ( $n < 0 ) {
 288                         $n += pow( 2, 32 );
 289                 }
 290                 return $n;
 291         }
 292
 293         /**
 294          * Convert a dotted-quad IP to a signed integer
 295          * Returns false on failure
 296          */
 297         public static function toSigned( $ip ) {
 298                 if ( $ip == '255.255.255.255' ) {
 299                         $n = -1;
 300                 } else {
 301                         $n = ip2long( $ip );
 302                         if ( $n == -1 ) {
 303                                 $n = false;
 304                         }
 305                 }
 306                 return $n;
 307         }
 308
 309         /**
 310          * Convert a network specification in CIDR notation to an integer network and a number of bits
 311          * @return array(string, int)
 312          */
 313         public static function parseCIDR( $range ) {
 314                 $parts = explode( '/', $range, 2 );
 315                 if ( count( $parts ) != 2 ) {
 316                         return array( false, false );
 317                 }
 318                 $network = IP::toSigned( $parts[0] );
 319                 if ( $network !== false && is_numeric( $parts[1] ) && $parts[1] >= 0 && $parts[1] <= 32 ) {
 320                         $bits = $parts[1];
 321                         if ( $bits == 0 ) {
 322                                 $network = 0;
 323                         } else {
 324                                 $network &= ~((1 << (32 - $bits)) - 1);
 325                         }
 326                         # Convert to unsigned
 327                         if ( $network < 0 ) {
 328                                 $network += pow( 2, 32 );
 329                         }
 330                 } else {
 331                         $network = false;
 332                         $bits = false;
 333                 }
 334                 return array( $network, $bits );
 335         }
 336
 337         /**
 338          * Given a string range in a number of formats, return the start and end of
 339          * the range in hexadecimal. For IPv4.
 340          *
 341          * Formats are:
 342          *     1.2.3.4/24          CIDR
 343          *     1.2.3.4 - 1.2.3.5   Explicit range
 344          *     1.2.3.4             Single IP
 345          * @return array(string, int)
 346          */
 347         public static function parseRange( $range ) {
 348                 if ( strpos( $range, '/' ) !== false ) {
 349                         # CIDR
 350                         list( $network, $bits ) = IP::parseCIDR( $range );
 351                         if ( $network === false ) {
 352                                 $start = $end = false;
 353                         } else {
 354                                 $start = sprintf( '%08X', $network );
 355                                 $end = sprintf( '%08X', $network + pow( 2, (32 - $bits) ) - 1 );
 356                         }
 357                 } elseif ( strpos( $range, '-' ) !== false ) {
 358                         # Explicit range
 359                         list( $start, $end ) = array_map( 'trim', explode( '-', $range, 2 ) );
 360                         $start = IP::toUnsigned( $start ); $end = IP::toUnsigned( $end );
 361                         if ( $start > $end ) {
 362                                 $start = $end = false;
 363                         } else {
 364                                 $start = sprintf( '%08X', $start );
 365                                 $end = sprintf( '%08X', $end );
 366                         }
 367                 } else {
 368                         # Single IP
 369                         $start = $end = IP::toHex( $range );
 370                 }
 371                 if ( $start === false || $end === false ) {
 372                         return array( false, false );
 373                 } else {
 374                         return array( $start, $end );
 375                 }
 376     }
 377
 378     /**
 379      * Determine if a given IPv4 address is in a given CIDR network
 380      * @param $addr The address to check against the given range.
 381      * @param $range The range to check the given address against.
 382      * @return bool Whether or not the given address is in the given range.
 383      */
 384     public static function isInRange( $addr, $range ) {
 385     // Convert to IPv6 if needed
 386         $unsignedIP = IP::toUnsigned6( IP::IPv4toIPv6($addr) );
 387         list( $start, $end ) = IP::parseRange6( IP::IPv4toIPv6($range) );
 388         return (($unsignedIP >= $start) && ($unsignedIP <= $end));
 389     }
 390
 391     /**
 392      * Convert some unusual representations of IPv4 addresses to their
 393      * canonical dotted quad representation.
 394      *
 395      * This currently only checks a few IPV4-to-IPv6 related cases.  More
 396      * unusual representations may be added later.
 397      *
 398      * @param $addr something that might be an IP address
 399      * @return valid dotted quad IPv4 address or null
 400      */
 401     public static function canonicalize( $addr ) {
 402         if ( IP::isValid( $addr ) )
 403             return $addr;
 404
 405         // IPv6 loopback address
 406         $m = array();
 407         if ( preg_match( '/^0*' . RE_IPV6_GAP . '1$/', $addr, $m ) )
 408             return '127.0.0.1';
 409
 410         // IPv4-mapped and IPv4-compatible IPv6 addresses
 411         if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . '(' . RE_IP_ADD . ')$/i', $addr, $m ) )
 412             return $m[1];
 413         if ( preg_match( '/^' . RE_IPV6_V4_PREFIX . RE_IPV6_WORD . ':' . RE_IPV6_WORD . '$/i', $addr, $m ) )
 414             return long2ip( ( hexdec( $m[1] ) << 16 ) + hexdec( $m[2] ) );
 415
 416         return null;  // give up
 417     }
 418 }
 419
 420 ?>