public function testIsInNetwork()
{
$ip = new Ip('2001:304:234a::1');
$this->assertEquals(true, $ip->isInNetwork(new Ip('2001:304:234a::'), 48));
$ip = new Ip('2001:304:234b::1');
$this->assertEquals(false, $ip->isInNetwork(new Ip('2001:304:234a::'), 48));
$ip = new Ip('127.2.4.5');
$this->assertEquals(true, $ip->isInNetwork(new Ip('127.2.3.4'), 16));
$ip = new Ip('127.2.127.9');
$this->assertEquals(false, $ip->isInNetwork(new Ip('127.2.128.0'), 17));
}
/**
* Tests if an IP address belongs to a specific network
*
* Accepts a network base address and a prefix length.
*
* @param Ip $base Base address for the network to test
* @param int $prefixlen Prefix length to test
* @return bool
*/
public function isInNetwork(Ip $base, $prefixlen)
{
$baseVersion = $base->getVersion();
$thisVersion = $this->getVersion();
if ($prefixlen < 0) {
throw new InvalidArgumentException('Prefix length cannot be negative');
}
if ($baseVersion !== $thisVersion) {
throw new InvalidArgumentException('Address version does not match supplied network base version');
}
if ($thisVersion === 4 && $prefixlen > 32) {
throw new InvalidArgumentException('Address version (4) was not supplied a correct prefix length');
}
if ($thisVersion === 6 && $prefixlen > 128) {
throw new InvalidArgumentException('Address version (6) was not supplied a correct prefix length');
}
// First create a 128-bit long binary string regardless of IP version.
// IPv4 addresses are left-padded with zeroes so that the algorithm
// can be used generically.
//
// Next, split the 128-bit string into 32-bit chunks, and convert them
// to unsigned integers. We can then use this to perform the bitwise
// comparisons that we need later.
$prefixIntegerArray = array_map('bindec', str_split(str_pad(str_pad(str_repeat('1', $prefixlen), $thisVersion === 4 ? 32 : 128, '0'), 128, '0', STR_PAD_LEFT), 32));
$baseIntegerArray = $base->toIntegerArray();
$thisIntegerArray = $this->toIntegerArray();
// If it's version 4, we just want to compare final array position
$start = $thisVersion === 4 ? 3 : 0;
for ($i = $start; $i < 4; $i++) {
$a = $thisIntegerArray[$i];
$b = $baseIntegerArray[$i];
$p = $prefixIntegerArray[$i];
// If the address ANDed with the prefix mask is not equal to the
// base address ANDed with the prefix mask, we can bail.
if (($a & $p) !== ($b & $p)) {
return false;
}
}
return true;
}