IP: Get IP Range based on CIDR Block

ipCalculateRange

/**
 * 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;
}

ipInRange

 /**
 * Check if IP address is within CIDR range
 * 
 * @param string $ip 127.0.0.1
 * @param string $cidr 127.0.0.1/28
 * @return bool 
 */
function ipInRange($ip, $cidr) {
    if ( strpos( $range, '/' ) == false ) {
      $range .= '/32';
    }

    // $range is in IP/CIDR format eg 127.0.0.1/24
    list( $range, $netmask ) = explode( '/', $range, 2 );
    $range_decimal = ip2long( $range );
    $ip_decimal = ip2long( $ip );
    $wildcard_decimal = pow( 2, ( 32 - $netmask ) ) - 1;
    $netmask_decimal = ~ $wildcard_decimal;
    return ( ( $ip_decimal & $netmask_decimal ) == ( $range_decimal & $netmask_decimal ) );
}