SMB3 Unix extensions

[Jeremy Allison]

On Fri, Apr 28, 2017 at 10:56:28AM +0200, Stefan Metzmacher wrote:
> Am 27.04.2017 um 18:13 schrieb Jeremy Allison:
> > On Thu, Apr 27, 2017 at 04:36:30PM +0200, Stefan Metzmacher wrote:
> >> Am 20.04.2017 um 17:52 schrieb Jeremy Allison:
> >>> On Wed, Apr 19, 2017 at 08:18:01PM -0500, Steve French wrote:
> >>>> If server guys are willing to add a negotiate context ... fine with me
> >>>> - but IIRC that was vetoed because at least one or two servers don't
> >>>> support negotiate context (Azure e.g.?)
> >>>
> >>> Not that I recall. Negotiate context was decided as the
> >>> right place to do it - no bullshit CreateContext on "\"
> >>> requests (which really don't make sense).
> >>
> >> As far as I remember the idea was to just do this by file handle.
> >>
> >> So the client will just try to use the create context and the returned
> >> create context defines the features available just for that file handle.
> > 
> > Yes, that's right.
> > 
> >> So NO global negotiation anymore!
> > 
> > That was my original idea, but no, we need it. The reason is
> > (David Kruse pointed this out) that it allows the client to
> > determine if a UNIX create context that is ignored by the server
> > is not returned because the server can't grant or doesn't want
> > to grant UNIX handles on this part of the file system, vs
> > a server that doesn't grant UNIX handles because it doesn't
> > implement UNIX extensions.
> > 
> > The initial Negprot extension tells the client that yes,
> > I can do UNIX handles I just don't want to for this handle.
> 
> Why does a client need to care about this?
> Just avoiding a few bytes for the ignored create context?

No, there was a good reason, I just can't remember
it right now whilst I'm writing my second SambaXP
talk :-).

Steve, can you remember the use case ?

> BTW: why is this a private discussion?

Souldn't be. Adding samba-technical back !