balmet.com

IPv6.php (5010B)

---

 <?php
 /**
  * Class to validate and to work with IPv6 addresses
  *
  * @package Requests
  * @subpackage Utilities
  */
 
 /**
  * Class to validate and to work with IPv6 addresses
  *
  * This was originally based on the PEAR class of the same name, but has been
  * entirely rewritten.
  *
  * @package Requests
  * @subpackage Utilities
  */
 class Requests_IPv6 {
 	/**
 	 * Uncompresses an IPv6 address
 	 *
 	 * RFC 4291 allows you to compress consecutive zero pieces in an address to
 	 * '::'. This method expects a valid IPv6 address and expands the '::' to
 	 * the required number of zero pieces.
 	 *
 	 * Example:  FF01::101   ->  FF01:0:0:0:0:0:0:101
 	 *           ::1         ->  0:0:0:0:0:0:0:1
 	 *
 	 * @author Alexander Merz <alexander.merz@web.de>
 	 * @author elfrink at introweb dot nl
 	 * @author Josh Peck <jmp at joshpeck dot org>
 	 * @copyright 2003-2005 The PHP Group
 	 * @license http://www.opensource.org/licenses/bsd-license.php
 	 * @param string $ip An IPv6 address
 	 * @return string The uncompressed IPv6 address
 	 */
 	public static function uncompress($ip) {
 		if (substr_count($ip, '::') !== 1) {
 			return $ip;
 		}
 
 		list($ip1, $ip2) = explode('::', $ip);
 		$c1              = ($ip1 === '') ? -1 : substr_count($ip1, ':');
 		$c2              = ($ip2 === '') ? -1 : substr_count($ip2, ':');
 
 		if (strpos($ip2, '.') !== false) {
 			$c2++;
 		}
 		// ::
 		if ($c1 === -1 && $c2 === -1) {
 			$ip = '0:0:0:0:0:0:0:0';
 		}
 		// ::xxx
 		elseif ($c1 === -1) {
 			$fill = str_repeat('0:', 7 - $c2);
 			$ip   = str_replace('::', $fill, $ip);
 		}
 		// xxx::
 		elseif ($c2 === -1) {
 			$fill = str_repeat(':0', 7 - $c1);
 			$ip   = str_replace('::', $fill, $ip);
 		}
 		// xxx::xxx
 		else {
 			$fill = ':' . str_repeat('0:', 6 - $c2 - $c1);
 			$ip   = str_replace('::', $fill, $ip);
 		}
 		return $ip;
 	}
 
 	/**
 	 * Compresses an IPv6 address
 	 *
 	 * RFC 4291 allows you to compress consecutive zero pieces in an address to
 	 * '::'. This method expects a valid IPv6 address and compresses consecutive
 	 * zero pieces to '::'.
 	 *
 	 * Example:  FF01:0:0:0:0:0:0:101   ->  FF01::101
 	 *           0:0:0:0:0:0:0:1        ->  ::1
 	 *
 	 * @see uncompress()
 	 * @param string $ip An IPv6 address
 	 * @return string The compressed IPv6 address
 	 */
 	public static function compress($ip) {
 		// Prepare the IP to be compressed
 		$ip       = self::uncompress($ip);
 		$ip_parts = self::split_v6_v4($ip);
 
 		// Replace all leading zeros
 		$ip_parts[0] = preg_replace('/(^|:)0+([0-9])/', '\1\2', $ip_parts[0]);
 
 		// Find bunches of zeros
 		if (preg_match_all('/(?:^|:)(?:0(?::|$))+/', $ip_parts[0], $matches, PREG_OFFSET_CAPTURE)) {
 			$max = 0;
 			$pos = null;
 			foreach ($matches[0] as $match) {
 				if (strlen($match[0]) > $max) {
 					$max = strlen($match[0]);
 					$pos = $match[1];
 				}
 			}
 
 			$ip_parts[0] = substr_replace($ip_parts[0], '::', $pos, $max);
 		}
 
 		if ($ip_parts[1] !== '') {
 			return implode(':', $ip_parts);
 		}
 		else {
 			return $ip_parts[0];
 		}
 	}
 
 	/**
 	 * Splits an IPv6 address into the IPv6 and IPv4 representation parts
 	 *
 	 * RFC 4291 allows you to represent the last two parts of an IPv6 address
 	 * using the standard IPv4 representation
 	 *
 	 * Example:  0:0:0:0:0:0:13.1.68.3
 	 *           0:0:0:0:0:FFFF:129.144.52.38
 	 *
 	 * @param string $ip An IPv6 address
 	 * @return string[] [0] contains the IPv6 represented part, and [1] the IPv4 represented part
 	 */
 	protected static function split_v6_v4($ip) {
 		if (strpos($ip, '.') !== false) {
 			$pos       = strrpos($ip, ':');
 			$ipv6_part = substr($ip, 0, $pos);
 			$ipv4_part = substr($ip, $pos + 1);
 			return array($ipv6_part, $ipv4_part);
 		}
 		else {
 			return array($ip, '');
 		}
 	}
 
 	/**
 	 * Checks an IPv6 address
 	 *
 	 * Checks if the given IP is a valid IPv6 address
 	 *
 	 * @param string $ip An IPv6 address
 	 * @return bool true if $ip is a valid IPv6 address
 	 */
 	public static function check_ipv6($ip) {
 		$ip                = self::uncompress($ip);
 		list($ipv6, $ipv4) = self::split_v6_v4($ip);
 		$ipv6              = explode(':', $ipv6);
 		$ipv4              = explode('.', $ipv4);
 		if (count($ipv6) === 8 && count($ipv4) === 1 || count($ipv6) === 6 && count($ipv4) === 4) {
 			foreach ($ipv6 as $ipv6_part) {
 				// The section can't be empty
 				if ($ipv6_part === '') {
 					return false;
 				}
 
 				// Nor can it be over four characters
 				if (strlen($ipv6_part) > 4) {
 					return false;
 				}
 
 				// Remove leading zeros (this is safe because of the above)
 				$ipv6_part = ltrim($ipv6_part, '0');
 				if ($ipv6_part === '') {
 					$ipv6_part = '0';
 				}
 
 				// Check the value is valid
 				$value = hexdec($ipv6_part);
 				if (dechex($value) !== strtolower($ipv6_part) || $value < 0 || $value > 0xFFFF) {
 					return false;
 				}
 			}
 			if (count($ipv4) === 4) {
 				foreach ($ipv4 as $ipv4_part) {
 					$value = (int) $ipv4_part;
 					if ((string) $value !== $ipv4_part || $value < 0 || $value > 0xFF) {
 						return false;
 					}
 				}
 			}
 			return true;
 		}
 		else {
 			return false;
 		}
 	}
 }