After searching around somewhat thoroughly, I noticed a slight lack of functions in PHP for handling IPv6. For my own personal satisfaction I created a few functions to help the transition.
The IPv6ToLong()
function is a temporary solution to that brought up here: How to store IPv6-compatible address in a relational database. It will split the IP in to two integers and return them in an array.
/**
* Convert an IPv4 address to IPv6
*
* @param string IP Address in dot notation (192.168.1.100)
* @return string IPv6 formatted address or false if invalid input
*/
function IPv4To6($Ip) {
static $Mask = '::ffff:'; // This tells IPv6 it has an IPv4 address
$IPv6 = (strpos($Ip, '::') === 0);
$IPv4 = (strpos($Ip, '.') > 0);
if (!$IPv4 && !$IPv6) return false;
if ($IPv6 && $IPv4) $Ip = substr($Ip, strrpos($Ip, ':')+1); // Strip IPv4 Compatibility notation
elseif (!$IPv4) return $Ip; // Seems to be IPv6 already?
$Ip = array_pad(explode('.', $Ip), 4, 0);
if (count($Ip) > 4) return false;
for ($i = 0; $i < 4; $i++) if ($Ip[$i] > 255) return false;
$Part7 = base_convert(($Ip[0] * 256) + $Ip[1], 10, 16);
$Part8 = base_convert(($Ip[2] * 256) + $Ip[3], 10, 16);
return $Mask.$Part7.':'.$Part8;
}
/**
* Replace '::' with appropriate number of ':0'
*/
function ExpandIPv6Notation($Ip) {
if (strpos($Ip, '::') !== false)
$Ip = str_replace('::', str_repeat(':0', 8 - substr_count($Ip, ':')).':', $Ip);
if (strpos($Ip, ':') === 0) $Ip = '0'.$Ip;
return $Ip;
}
/**
* Convert IPv6 address to an integer
*
* Optionally split in to two parts.
*
* @see https://stackoverflow.com/questions/420680/
*/
function IPv6ToLong($Ip, $DatabaseParts= 2) {
$Ip = ExpandIPv6Notation($Ip);
$Parts = explode(':', $Ip);
$Ip = array('', '');
for ($i = 0; $i < 4; $i++) $Ip[0] .= str_pad(base_convert($Parts[$i], 16, 2), 16, 0, STR_PAD_LEFT);
for ($i = 4; $i < 8; $i++) $Ip[1] .= str_pad(base_convert($Parts[$i], 16, 2), 16, 0, STR_PAD_LEFT);
if ($DatabaseParts == 2)
return array(base_convert($Ip[0], 2, 10), base_convert($Ip[1], 2, 10));
else return base_convert($Ip[0], 2, 10) + base_convert($Ip[1], 2, 10);
}
For these functions I typically implement them by calling this function first:
/**
* Attempt to find the client's IP Address
*
* @param bool Should the IP be converted using ip2long?
* @return string|long The IP Address
*/
function GetRealRemoteIp($ForDatabase= false, $DatabaseParts= 2) {
$Ip = '0.0.0.0';
if (isset($_SERVER['HTTP_CLIENT_IP']) && $_SERVER['HTTP_CLIENT_IP'] != '')
$Ip = $_SERVER['HTTP_CLIENT_IP'];
elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && $_SERVER['HTTP_X_FORWARDED_FOR'] != '')
$Ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
elseif (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] != '')
$Ip = $_SERVER['REMOTE_ADDR'];
if (($CommaPos = strpos($Ip, ',')) > 0)
$Ip = substr($Ip, 0, ($CommaPos - 1));
$Ip = IPv4To6($Ip);
return ($ForDatabase ? IPv6ToLong($Ip, $DatabaseParts) : $Ip);
}
Someone please tell me if I'm reinventing the wheel here or I've done something wrong.
This implementation converts IPv4 to IPv6. Any IPv6 address it doesn't touch.
Question&Answers:
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