Wireshark-dev: Re: [Wireshark-dev] colorizing sFlow
From: Sake Blok <[email protected]>
Date: Tue, 16 Oct 2007 18:49:06 +0200
On Tue, Oct 16, 2007 at 08:54:29AM -0700, Andrew Feren wrote:
> > IMO we need something like a protocol-as-payload flag to set at
> > some point into the dissection: It should have several meanings:
> > a) From now on dissection may break at any time and it's not an error
> > b) Don't update the info column any more
> > c) not relevant to filters (or just color-filters?)
> Now that I understand this a bit better I see that this is really a filter
> issue not a colorization issue.  Colorization just makes the filter issue
> obvious.  
> I think a protocol_as_payload flag may be the right approach.  The problem is
> that it looks like it could become a giant game of code whack-a-mole.

Maybe if the sFlow dissector has a preference to en/disable dissection
of it's payload would do the trick? I haven't looked at the code of 
the sFlow dissector, but this should be rather straightforward.

> Sake suggested looking in packet-ip.c for an example of using
> "pinfo->in_error_pkt".  This boils down to a specific instance of protocol as
> payload.  I implemented these few lines in sFlow and sFlow packets were no
> longer highlighted as TCP errors.  However, now they are highlighted as SMB. 
> If I remove the SMB rule they show up as HTTP, DCERPC, TCP, arp, etc.  I even
> see one matching "tcp.flags & 0x02 || tcp.flags.fin == 1".  Could be just
> about anything depending on what headers happen to get sampled.
> Using pinfo->in_error_pkt is a step in the right direction, but I'd still
> like   to find a more complete/general solution.

If it's just the coloring of payload inside the sFlow packets that you'd
like to disable, you could add a coloring rule at the top of the rule-list
(or after the coloring rules that you do want to apply to these packets)
that just colors sFlow packets with your default colors.

> > Does this make any sense? Would it be doable?
> Makes sense to me.  

Well, yes and no. One might want to see the payload being colored
others like yourself might not. If just disabling payload-dissection
suits your needs, I think it could be a nice enhancement to have 
a preference setting for it.