Class NetBIOSNameField

scapy/fields.py:1928–1967

class NetBIOSNameField(StrFixedLenField):
    def __init__(self, name, default, length=31):
        # type: (str, bytes, int) -> None
        StrFixedLenField.__init__(self, name, default, length)

    def h2i(self, pkt, x):
        # type: (Optional[Packet], bytes) -> bytes
        if x and len(x) > 15:
            x = x[:15]
        return x

    def i2m(self, pkt, y):
        # type: (Optional[Packet], Optional[bytes]) -> bytes
        if pkt:
            len_pkt = self.length_from(pkt) // 2
        else:
            len_pkt = 0
        x = bytes_encode(y or b"")  # type: bytes
        x += b" " * len_pkt
        x = x[:len_pkt]
        x = b"".join(
            struct.pack(
                "!BB",
                0x41 + (b >> 4),
                0x41 + (b & 0xf),
            )
            for b in x
        )
        return b" " + x

    def m2i(self, pkt, x):
        # type: (Optional[Packet], bytes) -> bytes
        x = x[1:].strip(b"\x00")
        return b"".join(map(
            lambda x, y: struct.pack(
                "!B",
                (((x - 1) & 0xf) << 4) + ((y - 1) & 0xf)
            ),
            x[::2], x[1::2]
        )).rstrip(b" ")


class StrLenField(StrField):