Wireshark · Wireshark-dev: Re: [Wireshark-dev] fragment_add_..(), pinfo->src/dst, IP vs. TCP Session

[Bill Meier <wmeier@xxxxxxxxxxx>]

David Aggeler wrote:
> Hi Bill,
>
> Thanks for you comments. I've looked at quite a few other dissectors and 
> the comments around the reassembly function calls do not increase 
> confidence.
> Therefore I'm debugging the reassemble module for quite a while now, to 
> understand of what is going on.
>
> For DICOM, I need to do the reassembly at two levels. The first one is 
> at the top, where I have a PDU length to request data.
> Here I plan to use tcp_dissect_pdus(), once I undestand how this 
> interacts with the heuristic hook. My custom merge at this level works 
> reasonable.
>
> The bigger challange is the second level. For PDVs, there's only a more 
> flag, and then tcp_dissect_pdus() can't help.And this is where I'm using 
> fragment_add_seq_next().
>
> David


A suggestion (if you haven't already decided what to do):

Store a (unique) value with the TCP conversation on which the PDV 
occurs; Use this as the id to fragment_add....

The unique value could be the same as what tcp_dissect_pdus uses: the 
frame number of the first frame containing the PDV.

Or: Use whatever makes sense for you for the unique id....

Bill