Home/ Questions/Q 129449
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-11T05:47:29+00:00

After searching around somewhat thoroughly, I noticed a slight lack of functions in PHP

  • 0

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) {     $Ip = '0.0.0.0';     // [snip: deleted some dangerous code not relevant to question. @webb]     if (isset($_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.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. How about inet_ntop()? Then instead of chopping things into integers, you just use a varbinary(16) to store it.

    • 0