samba - Jan 2018 - Samba 4.7.4 + bind9 DLZ /backend/ dropping delegated domain

No, I'm reading the dlz_bind9.c code.
I've found and fixed the problem.  It turns out that using a reference
counted singleton is a bad idea.  The singleton is defunct after reload.
If we simply create a new state object and destroy the old one as bind is
trying to let us do, things work out fine.
This works, at least, for bind9.9.  I cant test with the older (9.8), so it
is possible that the singleton approach was necessary for that.
Expect a pull request from me soon.



On 30 January 2018 at 11:55, Rowland Penny via samba <samba at
lists.samba.org>
wrote:
> On Tue, 30 Jan 2018 11:24:42 +0000
> Kristján Valur Jónsson <kristjan at rvx.is> wrote:
>
> > Right, that is the _workaround_.  It'd be great to see that
> > documented in the Wiki.
>
> It is now.
>
> > However, samba_dlz is supposed to support reload, and there has been
> > work on that file to fix slow reload previously.
> > I"m currently doing experiments to figure out what is going
wrong.
> >
> > One thing is clear, the messages from samba_dlz is confusing, since
> > it is actually not "shutting down".
> > Rather, samba_dlz, maintains a reference counted singleton of its
> > state. What happens during reload is:
> > 1) dlz_create is called.  The refcount is upped, same internal
> > instance returned to named and* nothing is logged.*
> > 2) dlz_configure() is called.
> > 3) dlz_destroy() is called.  The refcount is decreased (from 2 to 1),
> > nothing is destroyed, *but it incorrectly logs that it is shutting
> > down!*
> >
> > Clearly, bind expects to start a new instance of its dlz, initialize
> > it, and then destroy the old instance.
> >
>
> Still not sure where the problem lies, if you are only reading the Bind
> source code, then the problem is a Bind one, but if you are also
> reading the Samba code, then it could be a Samba one.
>
> Rowland
>
> --
> To unsubscribe from this list go to the following URL and read the
> instructions:  https://lists.samba.org/mailman/options/samba
>


-- 
Kv,
Kristján Valur Jónsson, RVX

On Tue, 30 Jan 2018 12:54:23 +0000
Kristján Valur Jónsson <kristjan at rvx.is> wrote:
> No, I'm reading the dlz_bind9.c code.
> I've found and fixed the problem.  It turns out that using a reference
> counted singleton is a bad idea.  The singleton is defunct after
> reload. If we simply create a new state object and destroy the old
> one as bind is trying to let us do, things work out fine.
> This works, at least, for bind9.9.  I cant test with the older (9.8),
> so it is possible that the singleton approach was necessary for that.
> Expect a pull request from me soon.
> 
> 
If you are going to propose a patch to fix this in the Samba code, then
you you need to send it to the samba-technical mailing list, it also
needs to be formatted correctly, see 'README.Coding' in the source root.

Rowland

Already created a pull request:
https://github.com/samba-team/samba/pull/124 as per
https://wiki.samba.org/index.php/Using_Git_for_Samba_Development
I'll subscribe to the technical list as well.



On 30 January 2018 at 13:38, Rowland Penny via samba <samba at
lists.samba.org>
wrote:
> On Tue, 30 Jan 2018 12:54:23 +0000
> Kristján Valur Jónsson <kristjan at rvx.is> wrote:
>
> > No, I'm reading the dlz_bind9.c code.
> > I've found and fixed the problem.  It turns out that using a
reference
> > counted singleton is a bad idea.  The singleton is defunct after
> > reload. If we simply create a new state object and destroy the old
> > one as bind is trying to let us do, things work out fine.
> > This works, at least, for bind9.9.  I cant test with the older (9.8),
> > so it is possible that the singleton approach was necessary for that.
> > Expect a pull request from me soon.
> >
> >
>
> If you are going to propose a patch to fix this in the Samba code, then
> you you need to send it to the samba-technical mailing list, it also
> needs to be formatted correctly, see 'README.Coding' in the source
root.
>
> Rowland
>
> --
> To unsubscribe from this list go to the following URL and read the
> instructions:  https://lists.samba.org/mailman/options/samba
>


-- 
Kv,
Kristján Valur Jónsson, RVX