Wireshark · Wireshark-dev: Re: [Wireshark-dev] How to see where exception occurs in Malformed packets

[Peter Wu <peter@xxxxxxxxxxxxx>]

On Tue, Mar 07, 2017 at 02:08:51PM +0000, Remy Leone wrote:
> Hello
> 
> Le sam. 4 mars 2017 à 00:00, Jaap Keuter <jaap.keuter@xxxxxxxxx> a écrit :
> 
> > Hi,
> >
> > Glib logging won't help you much, as in, malformed packet dissection isn't
> > a
> > problem in the underlying infrastructure of the program (which would cause
> > said
> > log messages to be generated), but a exception caught by the dissection
> > engine
> > itself. The common way to get forward is to retrieve the source code for
> > the
> > dissector the malformation is detected in and find the lines of code on
> > which
> > this exception is raised.
> 
> 
> How can I do this as efficiently as possible? I could do a bunch of printf
> but I was wondering if wireshark could help me find the exect lines at
> which the error occurs.
> 
> Best regards
> 
> Rémy

Usually I set a breakpoint at "except_throw" in the debugger and then
examine the backtrace when it is hit. This works without modifying the
source (but for a helpful trace, debugging symbols are recommended).
-- 
Kind regards,
Peter Wu
https://lekensteyn.nl