Validate and parse DNS record data for SOA record(s)
    :param rdata: DNS record data
    :return: dict w/fields

def soa_rec(rdata):
    '''
    Validate and parse DNS record data for SOA record(s)
    :param rdata: DNS record data
    :return: dict w/fields
    '''
    rschema = OrderedDict((
        ('mname', str),
        ('rname', str),
        ('serial', int),
        ('refresh', int),
        ('retry', int),
        ('expire', int),
        ('minimum', int),
    ))
    return _data2rec(rschema, rdata)