[PATCH] LIBNDR_FLAG_NOALIGN support in wireshark and PIDL

ronnie sahlberg ronniesahlberg at gmail.com
Mon Jan 18 17:13:28 MST 2010

The wireshark patch for this is fine.

I can apply these two patches to wireshark if you want me to.

Is the pidl patch ok with the upstream pidl maintainer (jelmer?) ?

On Tue, Jan 19, 2010 at 1:25 AM, Julien Kerihuel
<j.kerihuel at openchange.org> wrote:
> Hi Lists,
> Prior submitting the wireshark's part of this patch onto the wireshark
> bugzilla, I thought it might be worthwhile to have feedback from
> developers first.
> MAPI content is non-NDR compatible. It can be dissected using the
> existing NDR layer functions in epan/dissectors/packet-dcerpc-ndr.c but
> it requires offsets to be left intact prior effective dissection, which
> means there shouldn't be any offset adjustment when LIBNDR_FLAG_NOALIGN
> flag is used in PIDL.
> The following patches implement such behavior:
> 1. It adds a no_align gboolean variable to dcerpc_info structure
> (default set to FALSE)
> 2. when pidl generates the code and LIBNDR_FLAG_NOALIGN flag is used, it
> sets the no_align gboolean to TRUE which turns offste adjustment off in
> wireshark.
> I couldn't come up with a nicer solution so far, but these tiny patches
> truly improves the overall development effort for the MAPI dissector. It
> basically prevents from writing hand-written code for most of the MAPI
> calls. This also means this may help keeping the conformance files - in
> particular request.cnf.c and response.cnf.c - readable and prevent them
> from exponentially growing up.
> Another advantage is that it becomes conceivable to generate code for
> structures or others some non-dceprc dissectors using pidl. You would
> only have to describe the structures, specify LIBNDR_FLAG_NOALIGN flag
> and you would have automatic dissection code generated which you can
> refer to (or cut and paste).
> Cheers,
> Julien.
> ---
> Julien Kerihuel
> j.kerihuel at openchange.org
> OpenChange Project Manager
> GPG Fingerprint: 0B55 783D A781 6329 108A  B609 7EF6 FE11 A35F 1F79

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