Two functions to convert IPv6 & IPv4 addresses into 128bit ints and back again. They will use BCMath if installed otherwise will use the pure PHP Math_BigInteger class (included in the ZIP).
/**
* Converts human readable representation to a 128bit int
* which can be stored in MySQL using DECIMAL(39,0).
*
* Requires PHP to be compiled with IPv6 support.
* This could be made to work without IPv6 support but
* I don't think there would be much use for it if PHP
* doesn't support IPv6.
*
* @param string $ip IPv4 or IPv6 address to convert
* @return string 128bit string that can be used with DECIMNAL(39,0) or false
*/
if(!function_exists('inet_ptoi'))
{
function inet_ptoi($ip)
{
// make sure it is an ip
if (filter_var($ip, FILTER_VALIDATE_IP) === false)
return false;
$parts = unpack('N*', inet_pton($ip));
// fix IPv4
if (strpos($ip, '.') !== false)
$parts = array(1=>0, 2=>0, 3=>0, 4=>$parts[1]);
foreach ($parts as &$part)
{
// convert any unsigned ints to signed from unpack.
// this should be OK as it will be a PHP float not an int
if ($part < 0)
$part += 4294967296;
}
// use BCMath if the extension exists
if (function_exists('bcadd'))
{
$decimal = $parts[4];
$decimal = bcadd($decimal, bcmul($parts[3], '4294967296'));
$decimal = bcadd($decimal, bcmul($parts[2], '18446744073709551616'));
$decimal = bcadd($decimal, bcmul($parts[1], '79228162514264337593543950336'));
}
// otherwise use the pure PHP BigInteger
else
{
$decimal = new Math_BigInteger($parts[4]);
$part3 = new Math_BigInteger($parts[3]);
$part2 = new Math_BigInteger($parts[2]);
$part1 = new Math_BigInteger($parts[1]);
$decimal = $decimal->add($part3->multiply(new Math_BigInteger('4294967296')));
$decimal = $decimal->add($part2->multiply(new Math_BigInteger('18446744073709551616')));
$decimal = $decimal->add($part1->multiply(new Math_BigInteger('79228162514264337593543950336')));
$decimal = $decimal->toString();
}
return $decimal;
}
}
/**
* Converts a 128bit int to a human readable representation.
*
* Requires PHP to be compiled with IPv6 support.
* This could be made to work without IPv6 support but
* I don't think there would be much use for it if PHP
* doesn't support IPv6.
*
* @param string $decimal 128bit int
* @return string IPv4 or IPv6
*/
if(!function_exists('inet_ptoi'))
{
function inet_itop($decimal)
{
$parts = array();
// use BCMath if the extension exists
if (function_exists('bcadd'))
{
$parts[1] = bcdiv($decimal, '79228162514264337593543950336', 0);
$decimal = bcsub($decimal, bcmul($parts[1], '79228162514264337593543950336'));
$parts[2] = bcdiv($decimal, '18446744073709551616', 0);
$decimal = bcsub($decimal, bcmul($parts[2], '18446744073709551616'));
$parts[3] = bcdiv($decimal, '4294967296', 0);
$decimal = bcsub($decimal, bcmul($parts[3], '4294967296'));
$parts[4] = $decimal;
}
// otherwise use the pure PHP BigInteger
else
{
$decimal = new Math_BigInteger($decimal);
list($parts[1],) = $decimal->divide(new Math_BigInteger('79228162514264337593543950336'));
$decimal = $decimal->subtract($parts[1]->multiply(new Math_BigInteger('79228162514264337593543950336')));
list($parts[2],) = $decimal->divide(new Math_BigInteger('18446744073709551616'));
$decimal = $decimal->subtract($parts[2]->multiply(new Math_BigInteger('18446744073709551616')));
list($parts[3],) = $decimal->divide(new Math_BigInteger('4294967296'));
$decimal = $decimal->subtract($parts[3]->multiply(new Math_BigInteger('4294967296')));
$parts[4] = $decimal;
$parts[1] = $parts[1]->toString();
$parts[2] = $parts[2]->toString();
$parts[3] = $parts[3]->toString();
$parts[4] = $parts[4]->toString();
}
foreach ($parts as &$part)
{
// convert any signed ints to unsigned for pack
// this should be fine as it will be treated as a float
if ($part > 2147483647)
$part -= 4294967296;
}
$ip = inet_ntop(pack('N4', $parts[1], $parts[2], $parts[3], $parts[4]));
// fix IPv4 by removing :: from the beginning
if (strpos($ip, '.') !== false)
return substr($ip, 2);
return $ip;
}
}
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