I have followed the discussion about a possible bug/feature in
the display in ethereal 0.8.6/0.8.7 with considerable interest,
but I still feel that there is a case for looking at how flags are
displayed in greater depth.
At present, it seems that ethereal regards each and every flag
as a single stand alone boolean which is on or off (having appropriate
labels in a TRUE/FALSE structure) and displayed left justified.
This is despite the fact that throughout the code we have comments
in the form 'FLAGS field' recognising that flags come in bunches,
and programmers are quite used to hardware concepts such as a
FLAGS Word, Half-Word or Byte.
For my part, I would like flags to be displayed concisely in their
location within a flags field, videlicet:
Header Flags
c... .GTr
.000 1... = PDU Type: Invoke
.... .11. = Trailer flags: Packet re-assembly not supported
in which
bit 0 is a flag C = Continuation present, c = continuation absent
bits 1-4 are a bit field holding the type of the packet
bit 5 is the Group Trailer [G/g] flag
bit 6 is the Transmission Trailer [T/t] flag
bit 7 is the Re-transmission indicator [R/r]
Note that bits 5 and 6 have a special meaning when both are set, that
the implementation does not support packet fragmentation/re-assembly
at all, and these bits are available for interpretation as bit field.
If I were to submit a patch implementing a type FT_FLAGS_BYTE, would
this be accepted. It would be in competition with the existing FT_BOOLEAN
type but would not supplant it.
Ben.
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