I'd like to resurrect this. Here's a quick summary:
* The TRANSUM post-dissector requires access to some decoded values during
the first pass across the trace file
* Defining values (e.g. smb2.cmd) in a “fake tap” causes the values to be
available in the following scenarios:
* Wireshark with a C plugin
* Wireshark with a LUA plugin
* Tshark with a LUA plugin
* Tshark with a C plugin doesn’t work i.e. the fake tap values are not
available during the first pass
* The cause is identified and just due to an inconsistency in code – see
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=13393
* Guy suggested that I rewrite TRANSUM as a tap but that suffers from the
same inconsistency problem
As making the code consistent has been rejected and the tap idea won’t work,
where do we go from here?
Thanks and regards…Paul
-----Original Message-----
From: Guy Harris (Code Review) [mailto:[email protected]]
Sent: 13 February 2017 04:03
To: Michael Mann <[email protected]>
Cc: Petri Dish Buildbot <[email protected]>; Paul Offord
<[email protected]>
Subject: Change in wireshark[master]: tshark: Always have the same conditions
to determine if tree...
Guy Harris has posted comments on this change.
Change subject: tshark: Always have the same conditions to determine if tree
should be created
......................................................................
Patch Set 2: Code-Review-2
OK, the problem here is that the TRANSUM "dissector" is doing both tap-like
things (reading the protocol tree and processing data) and post-dissector-like
things (adding stuff to the protocol tree based on the results of that
processing).
Given that taps are run *after* post-dissectors, this means that it has to
"cheat" and do the tap-like things in the post-dissector, but post-dissectors
are, like other dissectors, handed a protocol tree only if there's a need to
generate one.
For this, we need a way to do the "read the protocol tree and process it" stuff
*before* the post-dissector is run, i.e. a way to register taps to be run
*before* the post-dissectors.
(In the longer term, we probably need to re-think both taps and post-dissectors
in a number of ways, and make whatever changes are necessary to get done what
the taps and post-dissectors are currently doing in ways that don't involve
abusing those mechanisms to get things done.
I'm a little suspicious, for example, of the Parallel Redundancy Protocol
trailer post-dissector - it's a protocol that's actually processing part of the
packet data; see the "This is horribly broken" comment I added to it a while
ago.
We might also want a way to have taps/"post-"dissectors that act as extensions
to particular protocol dissectors - that might be what TRANSUM, and possibly
MATE, *really* want to be.)
--
To view, visit https://code.wireshark.org/review/20078
To unsubscribe, visit https://code.wireshark.org/review/settings
Gerrit-MessageType: comment
Gerrit-Change-Id: I69bb395b55b73f26665d90f341c92a978e50aa70
Gerrit-PatchSet: 2
Gerrit-Project: wireshark
Gerrit-Branch: master
Gerrit-Owner: Michael Mann <[email protected]<mailto:[email protected]>>
Gerrit-Reviewer: Guy Harris <[email protected]<mailto:[email protected]>>
Gerrit-Reviewer: Michael Mann
<[email protected]<mailto:[email protected]>>
Gerrit-Reviewer: Paul Offord
<[email protected]<mailto:[email protected]>>
Gerrit-Reviewer: Petri Dish Buildbot
<[email protected]<mailto:[email protected]>>
Gerrit-HasComments: No
______________________________________________________________________
This message contains confidential information and is intended only for the
individual named. If you are not the named addressee you should not
disseminate, distribute or copy this e-mail. Please notify the sender
immediately by e-mail if you have received this e-mail by mistake and delete
this e-mail from your system.
Any views or opinions expressed are solely those of the author and do not
necessarily represent those of Advance Seven Ltd. E-mail transmission cannot be
guaranteed to be secure or error-free as information could be intercepted,
corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The
sender therefore does not accept liability for any errors or omissions in the
contents of this message, which arise as a result of e-mail transmission.
Advance Seven Ltd. Registered in England & Wales numbered 2373877 at Endeavour
House, Coopers End Lane, Stansted, Essex CM24 1SJ
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please visit http://www.symanteccloud.com
______________________________________________________________________
___________________________________________________________________________
Sent via: Wireshark-dev mailing list <[email protected]>
Archives: https://www.wireshark.org/lists/wireshark-dev
Unsubscribe: https://www.wireshark.org/mailman/options/wireshark-dev
mailto:[email protected]?subject=unsubscribe
