Wireshark mailing list archives

Re: Defragmenting non-tcp streams


From: Guy Harris <guy () alum mit edu>
Date: Thu, 7 Jan 2010 03:26:32 -0800


On Jan 7, 2010, at 1:48 AM, paul () wsh sbrk co uk wrote:

TCP has a tcp_dissect_pdus() function that higher protocols can use
to  eliminate their dependency on the TCP framing. Is there anything
generic for other layers? I'm writing a USB dissector which is really
a serial protocol being transported over USB.

That's

        http://www.nordicsemi.com/files/Product/data_sheet/User_guide_ANT.pdf

right?

If so, and if you're reassembling the packets in a burst transfer, this isn't a byte stream, so you can ignore the TCP 
dissector, and look instead at the IP dissector for an example.  It's not *quite* the same as IP, as

        1) you have sequence numbers rather than byte offsets, so you'd use fragment_add_seq_check() rather than 
fragment_add_check();

        2) the sequence number wraps around, so you'd have to keep some state and provide a "synthesized" sequence 
number that doesn't wrap around.
___________________________________________________________________________
Sent via:    Wireshark-dev mailing list <wireshark-dev () wireshark org>
Archives:    http://www.wireshark.org/lists/wireshark-dev
Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev
             mailto:wireshark-dev-request () wireshark org?subject=unsubscribe


Current thread: