<?php
declare(strict_types=1);
class StackOverflowCopyPaste
{
/** @var int $v4MaskBits */
private $v4MaskBits;
/** @var int $v6MaskBits */
private $v6MaskBits;
/**
* @param int $v4MaskBits
* @param int $v6MaskBits
*/
public function __construct(int $v4MaskBits = 24, int $v6MaskBits = 48)
{
$this->v4MaskBits = $v4MaskBits;
$this->v6MaskBits = $v6MaskBits;
}
/**
* Return the given subnet for an IP and the configured mask bits
*
* Determine if the IP is an IPv4 or IPv6 address, then pass to the correct
* method for handling that specific type.
*
* @param string $ip
* @return string
*/
public function getSubnet(string $ip): string
{
if (\preg_match('/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/', $ip)) {
return $this->getIPv4Subnet(
$ip,
(int) ($this->v4MaskBits ?? 32)
);
}
return $this->getIPv6Subnet(
$ip,
(int) ($this->v6MaskBits ?? 128)
);
}
/**
* Return the given subnet for an IPv4 address and mask bits
*
* @param string $ip
* @param int $maskBits
* @return string
*/
public function getIPv4Subnet(string $ip, int $maskBits = 32): string
{
$binary = \inet_pton($ip);
for ($i = 32; $i > $maskBits; $i -= 8) {
$j = \intdiv($i, 8) - 1;
$k = (int) \min(8, $i - $maskBits);
$mask = (0xff - ((1 << $k) - 1));
$int = \unpack('C', $binary[$j]);
$binary[$j] = \pack('C', $int[1] & $mask);
}
return \inet_ntop($binary).'/'.$maskBits;
}
/**
* Return the given subnet for an IPv6 address and mask bits
*
* @param string $ip
* @param int $maskBits
* @return string
*/
public function getIPv6Subnet(string $ip, int $maskBits = 48): string
{
$binary = \inet_pton($ip);
for ($i = 128; $i > $maskBits; $i -= 8) {
$j = \intdiv($i, 8) - 1;
$k = (int) \min(8, $i - $maskBits);
$mask = (0xff - ((1 << $k) - 1));
$int = \unpack('C', $binary[$j]);
$binary[$j] = \pack('C', $int[1] & $mask);
}
return \inet_ntop($binary).'/'.$maskBits;
}
}
$mask = new StackOverflowCopyPaste(24, 48);
var_dump($mask->getSubnet('12.34.56.78'));
var_dump($mask->getSubnet('2001:0db8:85a3:0000:0000:8a2e:0370:7334'));
preferences:
17.21 ms | 402 KiB | 5 Q