/libraries/simplepie/SimplePie/Net/IPv6.php

<?php
/**
 * SimplePie
 *
 * A PHP-Based RSS and Atom Feed Framework.
 * Takes the hard work out of managing a complete RSS/Atom solution.
 *
 * Copyright (c) 2004-2009, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 * 	* Redistributions of source code must retain the above copyright notice, this list of
 * 	  conditions and the following disclaimer.
 *
 * 	* Redistributions in binary form must reproduce the above copyright notice, this list
 * 	  of conditions and the following disclaimer in the documentation and/or other materials
 * 	  provided with the distribution.
 *
 * 	* Neither the name of the SimplePie Team nor the names of its contributors may be used
 * 	  to endorse or promote products derived from this software without specific prior
 * 	  written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
 * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @package SimplePie
 * @version 1.3-dev
 * @copyright 2004-2010 Ryan Parman, Geoffrey Sneddon, Ryan McCue
 * @author Ryan Parman
 * @author Geoffrey Sneddon
 * @author Ryan McCue
 * @link http://simplepie.org/ SimplePie
 * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 * @todo phpDoc comments
 */


/**
 * Class to validate and to work with IPv6 addresses.
 *
 * @package SimplePie
 * @copyright 2003-2005 The PHP Group
 * @license http://www.opensource.org/licenses/bsd-license.php
 * @link http://pear.php.net/package/Net_IPv6
 * @author Alexander Merz <alexander.merz@web.de>
 * @author elfrink at introweb dot nl
 * @author Josh Peck <jmp at joshpeck dot org>
 * @author Geoffrey Sneddon <geoffers@gmail.com>
 */
class SimplePie_Net_IPv6
{
	/**
	 * Removes a possible existing netmask specification of an IP address.
	 *
	 * @param string $ip the (compressed) IP as Hex representation
	 * @return string the IP the without netmask
	 * @since 1.1.0
	 * @access public
	 * @static
	 */
	public static function removeNetmaskSpec($ip)
	{
		if (strpos($ip, '/') !== false)
		{
			list($addr, $nm) = explode('/', $ip);
		}
		else
		{
			$addr = $ip;
		}
		return $addr;
	}

	/**
	 * Uncompresses an IPv6 address
	 *
	 * RFC 2373 allows you to compress zeros in an address to '::'. This
	 * function expects an valid IPv6 address and expands the '::' to
	 * the required zeros.
	 *
	 * Example:	 FF01::101	->	FF01:0:0:0:0:0:0:101
	 *			 ::1		->	0:0:0:0:0:0:0:1
	 *
	 * @access public
	 * @static
	 * @param string $ip a valid IPv6-address (hex format)
	 * @return string the uncompressed IPv6-address (hex format)
	 */
	public static function Uncompress($ip)
	{
		$uip = SimplePie_Net_IPv6::removeNetmaskSpec($ip);
		$c1 = -1;
		$c2 = -1;
		if (strpos($ip, '::') !== false)
		{
			list($ip1, $ip2) = explode('::', $ip);
			if ($ip1 === '')
			{
				$c1 = -1;
			}
			else
			{
				$pos = 0;
				if (($pos = substr_count($ip1, ':')) > 0)
				{
					$c1 = $pos;
				}
				else
				{
					$c1 = 0;
				}
			}
			if ($ip2 === '')
			{
				$c2 = -1;
			}
			else
			{
				$pos = 0;
				if (($pos = substr_count($ip2, ':')) > 0)
				{
					$c2 = $pos;
				}
				else
				{
					$c2 = 0;
				}
			}
			if (strstr($ip2, '.'))
			{
				$c2++;
			}
			// ::
			if ($c1 === -1 && $c2 === -1)
			{
				$uip = '0:0:0:0:0:0:0:0';
			}
			// ::xxx
			else if ($c1 === -1)
			{
				$fill = str_repeat('0:', 7 - $c2);
				$uip =	str_replace('::', $fill, $uip);
			}
			// xxx::
			else if ($c2 === -1)
			{
				$fill = str_repeat(':0', 7 - $c1);
				$uip =	str_replace('::', $fill, $uip);
			}
			// xxx::xxx
			else
			{
				$fill = str_repeat(':0:', 6 - $c2 - $c1);
				$uip =	str_replace('::', $fill, $uip);
				$uip =	str_replace('::', ':', $uip);
			}
		}
		return $uip;
	}

	/**
	 * Splits an IPv6 address into the IPv6 and a possible IPv4 part
	 *
	 * RFC 2373 allows you to note the last two parts of an IPv6 address as
	 * an IPv4 compatible address
	 *
	 * Example:	 0:0:0:0:0:0:13.1.68.3
	 *			 0:0:0:0:0:FFFF:129.144.52.38
	 *
	 * @access public
	 * @static
	 * @param string $ip a valid IPv6-address (hex format)
	 * @return array [0] contains the IPv6 part, [1] the IPv4 part (hex format)
	 */
	public static function SplitV64($ip)
	{
		$ip = SimplePie_Net_IPv6::Uncompress($ip);
		if (strstr($ip, '.'))
		{
			$pos = strrpos($ip, ':');
			$ip[$pos] = '_';
			$ipPart = explode('_', $ip);
			return $ipPart;
		}
		else
		{
			return array($ip, '');
		}
	}

	/**
	 * Checks an IPv6 address
	 *
	 * Checks if the given IP is IPv6-compatible
	 *
	 * @access public
	 * @static
	 * @param string $ip a valid IPv6-address
	 * @return bool true if $ip is an IPv6 address
	 */
	public static function checkIPv6($ip)
	{
		$ipPart = SimplePie_Net_IPv6::SplitV64($ip);
		$count = 0;
		if (!empty($ipPart[0]))
		{
			$ipv6 = explode(':', $ipPart[0]);
			for ($i = 0; $i < count($ipv6); $i++)
			{
				$dec = hexdec($ipv6[$i]);
				$hex = strtoupper(preg_replace('/^[0]{1,3}(.*[0-9a-fA-F])$/', '\\1', $ipv6[$i]));
				if ($ipv6[$i] >= 0 && $dec <= 65535 && $hex === strtoupper(dechex($dec)))
				{
					$count++;
				}
			}
			if ($count === 8)
			{
				return true;
			}
			elseif ($count === 6 && !empty($ipPart[1]))
			{
				$ipv4 = explode('.', $ipPart[1]);
				$count = 0;
				foreach ($ipv4 as $ipv4_part)
				{
					if ($ipv4_part >= 0 && $ipv4_part <= 255 && preg_match('/^\d{1,3}$/', $ipv4_part))
					{
						$count++;
					}
				}
				if ($count === 4)
				{
					return true;
				}
			}
			else
			{
				return false;
			}

		}
		else
		{
			return false;
		}
	}
}