bfd.py 文件源码

def parser(cls, buf):
        (diag, flags, detect_mult, length, my_discr, your_discr,
         desired_min_tx_interval, required_min_rx_interval,
         required_min_echo_rx_interval) = \
            struct.unpack_from(cls._PACK_STR, buf[:cls._PACK_STR_LEN])

        ver = diag >> 5
        diag = diag & 0x1f
        state = flags >> 6
        flags = flags & 0x3f

        if flags & BFD_FLAG_AUTH_PRESENT:
            auth_type = six.indexbytes(buf, cls._PACK_STR_LEN)
            auth_cls = cls._auth_parsers[auth_type].\
                parser(buf[cls._PACK_STR_LEN:])[0]
        else:
            auth_cls = None

        msg = cls(ver, diag, state, flags, detect_mult,
                  my_discr, your_discr, desired_min_tx_interval,
                  required_min_rx_interval, required_min_echo_rx_interval,
                  auth_cls)

        return msg, None, None