FF01:0:0:0:0:0:0:101 * ::1 -> 0:0:0:0:0:0:0:1 * * @author Alexander Merz * @author elfrink at introweb dot nl * @author Josh Peck * @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; } } }