Wireshark mailing list archives
Re: Reassemble serial protocols payloads
From: Tomasz Moń <desowin () gmail com>
Date: Sat, 11 Jul 2020 11:20:53 +0200
On Sun, Jul 5, 2020 at 5:05 PM Tomasz Moń <desowin () gmail com> wrote:
I am not sure if the approach I am pursuing is good or bad. The work in progress I have produced so far is at [1]. I am stuck at the point where, I need to either: * pass the "partially reassembled" tvb to MPSSE to check if it is complete, or
This is what I actually implemented in Patch Set 7 [1]. The only issue is that I am hijacking the pinfo->curr_layer_num value to make process_reassembled_data() happy. FTDI FT dissector doesn't know if the last fragment is really the last one unless it passes the data to the next dissector. There is absolutely no metadata that could help with it as FTDI FT is pretty much a direct replacement to UART (COM port) and is pretty much transparent to the actual serial protocol used. Passing the data to the MPSSE dissector results in curr_layer_num being increased if it dissected the data (when it is the last fragment). This would prevent the process_reassembled_data() (after the first pass) from returning the reassembled tvb in FTFI FT which in turn prevents the data from being passed to the next dissector.
* mark the data as reassembled as soon as I receive X additional bytes, but then after passing such reassembled data to MPSSE, it should be possible to "unmark" in case it needs even more bytes (in case the original estimate changes based on the new information).
I have had no success with this approach. [1] https://code.wireshark.org/review/37709 ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://www.wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
Current thread:
- Reassemble serial protocols payloads Tomasz Moń (Jul 05)
- Re: Reassemble serial protocols payloads Tomasz Moń (Jul 11)
- Re: Reassemble serial protocols payloads Guy Harris (Jul 12)