Function _fletcher16

scapy/utils.py:604–614

(charbuf)

def _fletcher16(charbuf):
    # type: (bytes) -> Tuple[int, int]
    # This is based on the GPLed C implementation in Zebra <http://www.zebra.org/>  # noqa: E501
    c0 = c1 = 0
    for char in charbuf:
        c0 += char
        c1 += c0

    c0 %= 255
    c1 %= 255
    return (c0, c1)


@conf.commands.register