Re: How to stop dissection in middle of malformed packet?

[Pascal Quantin <pascal.quantin () gmail com>]

Hi Dmitry,

2016-11-16 21:51 GMT+01:00 Dmitry Lazurkin <dilaz03 () gmail com>:

> Thank you for reply.
>
> After return dissection function continue parsing rest of packet. I think
> this is not good.

The trend lately was to remove any exception triggering from the dissectors
code, and keep them in the proto_tree_add_XXX functions. So addind them
back might not be a good idea.
I did not look at the kafka code, but you probably have ways to stop
dissection by incrementing offset enough to reach the end of the packet for
example.

Pascal.

PS. Question about dissection of kafka strings, bytes and arrays.
> On 11/16/2016 11:29 PM, Alexis La Goutte wrote:
>
> Hi,
>
> You need to add a expert info and return
> There is already check on proto_tree_add_* function to detect malformed
> value (and automally return)
>
> Cheers
>
> On Wed, Nov 16, 2016 at 5:57 PM, Dmitry Lazurkin <dilaz03 () gmail com>
> wrote:
>
> > Hello.
> >
> > I read packet header and try to read string length and string data. But
> > string length field has illegal value. I add expert info. But how to
> > stop dissection after adding expert info? I can not dissect rest of
> > packet at this point. I can return error code from this function, but
> > calling tree may be too big. May be exists more graceful solution?
> > Something like exceptions in C++.
> >
> > PS. I found DISSECTOR_VERIFY_DATA in mailing lists, but it is not
> > implemented in source code.
> >
> >
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>
>
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