Return PTR name of given IP
    :param rdata: IP address
    :return: PTR record name

def ptr_name(rdata):
    '''
    Return PTR name of given IP
    :param rdata: IP address
    :return: PTR record name
    '''
    try:
        return ipaddress.ip_address(rdata).reverse_pointer
    except ValueError:
        log.error(
            'Unable to generate PTR record; %s is not a valid IP address',
            rdata
        )
        return False