Ethereal-dev: Re: [Ethereal-dev] Ethereal highighting

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From: John McDermott <jjm@xxxxxxxxxx>
Date: Fri, 02 Nov 2001 16:59:42 -0700
Karl Freter wrote:
> 
> I think I'm close here.  My original request was to highlight an entire
> line.  [Highlighting an individual item within a protocol tree is an
> excellent idea, albeit one I can wait for.]  Ideally :-), I would be
> able to signal a common error flag or call a common routine if ANY field
> in any of the protocol stacks had an error.  Then I would see that line
> backlit and I could open each protocol layer to see what was in error.

I guess I thought 'line' meant "line in the packet list".  If it does
then what you say below seems to be what I suggested and will
"undoubtedly" work.
> 
> It sounds like this may or may not be doable (I haven't yet read the
> links that Guy identified). A potential compromise might be something
> like what's done for ICMP bad checksums.  There is a hidden, filterable,
> boolean item called "hf_icmp_checksum" that gets set (via a call to
> proto_tree_add_item_hidden()) when a bad checksum is encountered.  I

I am not sure if one can filter on a hidden item.  I don't have any
broken ICMP implementations around here :-) to test that one with.  Also
my box running packet building software has been overwritten with w2k
for the time being so I cannot test it by faking packets either.  If you
can filter on that field, though, you can use it in a colorization field
as they use the same filtering scheme as display filters.

> believe that a filter rule can then be added to identify records that
> have this field set.  I could add one of these for each item I wanted to
> include in the error list.  This means my filter line may have several
> items (ip checksum, tcp checksum, ICMP checksum, etc.) but it will
> identify all the records that have the errors I'm looking for.

I believe that is correct, if the filters can see hidden items (which I
think they can).

--john

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John McDermott, Writer and Consultant
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