def get_link_prop_keys(props):
    """
    This function can be used to pull out the primary keys from a dictionary, and return success
    iff all primary keys are present.
    :param props: the dict
    :return: all primary keys, and success if they were all present.
    """
    src_sw = props.get('src_switch','')
    src_pt = props.get('src_port','')
    dst_sw = props.get('dst_switch','')
    dst_pt = props.get('dst_port','')
    success = (len(src_sw) > 0) and (len(src_pt) > 0) and (len(dst_sw) > 0) and (len(dst_pt) > 0)
    return success,src_sw,src_pt,dst_sw,dst_pt