Re: [ethereal-dev] Thoughs around the info field for TCP Application level protocols

[guy@xxxxxxxxxx (Guy Harris)]

> In my last EM about Telnet I said I was unhappy with what I had done in the
> Telnet (and by extension in the FTP) protocol decoder.
> 
> I simply put Telnet Data ... in that field.
> 
> NetMon puts the relevant TCP info, including flags and sequence numbers
> there as well as any relevant protocol info if it can.

I assume you're referring to the summary line (the "Description" column
in NetMon, and the "Info" column in Ethereal) here, as the TCP
information is already in the TCP section of the detail display, and as
the detail information displays the actual data for Telnet data.

Which version of NetMon is that? The version I have (the "About" box
just says "Network Monitor Version 1.1 Copyright(C) 1992-1995 Microsoft
Corporation", and its title bar says "Retail 316 Jun 23 1995") just says
only "To Client With Port = XXXXX" or "To Server From Port = XXXXX" in
the summary section; yours might be a later version.

> I was thinking that I might do the same.  This means that I will have to
> retrieve the text that is in that field and add to it.

I.e., have the Telnet dissector add the Telnet information to the TCP
information (as the TCP dissector is called first, and then the Telnet
dissector is called)?

> A simple enough task. Does ethereal allow you to retrieve a field?

There's currently no routine that returns the contents of a column, but
it wouldn't be hard to add.

> Or, should we write an append routine?

That might be better, if all we expect is to have stuff added to the
column.

Are you thinking of doing this just for the FTP data stream, or for the
FTP control stream as well? Putting the TCP information *and* the FTP
request or response in the "Info" column might make it a bit crowded;
for Telnet, there's not much to lose by replacing "Telnet Data" with TCP
information, but for the FTP control stream, the request or response is
a nice thing to have in the summary.

I'd been thinking that this might be another application for a
multi-line summary display for a frame, with the ability to enable or
disable transport-layer (or perhaps even lower-layer) summary
information as well as the top-layer summary information.