Re: more default uid/gid for NFS in mountd

On 05/08/2017 06:45, Rick Macklem wrote:
> Hi,
> 
> Five years ago (yea, it slipped through a crack;-), Slawa reported that files
> created by root would end up owned by uid 2**32-2 (-2 as uint32_t).
> This happens if there is no "-maproot=<user>" in the /etc/exports line.
> 
> The cause is obvious. The value is set to -2 by default.
> 
> The question is... Should this be changed to 65534 (ie "nobody")?
> - It would seem more consistent to make it the uid of nobody, but I can also see
>   the argument that since it has been like this *forever*, that changing it would be
>   a POLA violation.
> What do others think?

Since the change is easily communicated in the release notes, I think it seems
quite reasonable, especially if you limit it to 12.0.

> It is also the case that mountd.c doesn't look "nobody" up in the password database
> to set the default. It would be nice to do this, but it could result in the mountd daemon
> getting "stuck" during a boot waiting for an unresponsive LDAP service or similar.
> Does doing this sound like a good idea?

I imagine the lookup could be useful in heterogeneous networks.

You might consider adding a CLI flag to mountd to let the admin choose the user
by UID/GID, and possibly by username/groupname.  That would be a reasonable
workaround for networks that often hit the lookup problem.

Eric