Wireshark-dev: Re: [Wireshark-dev] wireshark capture/filtering question
From: Graham Bloice <graham.bloice@xxxxxxxxxxxxx>
Date: Fri, 20 Nov 2020 14:55:06 +0000


On Fri, 20 Nov 2020 at 14:49, John Dill <John.Dill@xxxxxxxxxxxxxxxxx> wrote:

I've had some recent discussions about adding some network capture to our avionics data capture dashboard program.  Currently, the architecture uses a Java program as the GUI and a TCP socket interface for playback/record control and data with a C program capturing 1553 data.  The C program has the capability of reading from a file or the live card and streaming 1553 packets to file and to the GUI for processing.

 

What I would like to try to do is sniff out the packets for Control Display Unit (CDU) key presses and the Display screen data (which includes a 24x15 grid of characters and attribute data for each character).  The initial goal of this is to provide a real time virtual CDU display, and if things go well, store the display and key presses packet data so that during playback of a recording, one can see a virtual display of what happened between what the pilots are doing vs the 1553 data.  All of this display data is on a single port, and we currently have a plugin that processes all the Network Data Objects for that port.

 

The idea that was passed around would be to either integrate the packet capture portion in with the existing 1553 data capture program, or integrate the 1553 data capture in with a Wireshark command line tool.  Another factor they are considering is looking at chapter 10 to multiplex the 1553 and ethernet data into a single file format, so that complicates matters further (although that should make the time sync of 1553 and display playback easier).

 

I'm just wondering if anyone here has had experience using Wireshark utilities as a capture interface for streaming filtered network packets to another application, and maybe I can follow in their footsteps.

 

The problem appears to be pretty complex, so hopefully I explained what I want to try to do.  As a first pass, I think my goal will be to see if I can wrangle a simple dashboard application that takes a live filtered stream of packets from dumpcap or tshark, and forward that data to a GUI for display (basically part of the backend for a virtual CDU display).

 

Any ideas would be greatly appreciated.  If there's some source files to study, that would be helpful too.  I've only implemented a few packet dissector plugins for various avionics protocols, not gone this deep into the internals.

 

Thanks,

John D.


Hi John,

To clarify, you want to feed the 1553 stream into the wireshark engine, apply some engine filtering and then output some products of that to another application?
 
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Graham Bloice