/**
 * Get the IP range block based on CIDR
 *
 * @param string $cidr 127.0.0.1/28
 * @return array
 */
function ipCalculateRange($cidr) {
    $range = array();
    $cidr = explode('/', $cidr);
    $range[0] = long2ip((ip2long($cidr[0])) & ((-1 << (32 - (int)$cidr[1]))));
    $range[1] = long2ip((ip2long($range[0])) + pow(2, (32 - (int)$cidr[1])) - 1);
    return $range;
}