uid_wrapper: Add uwrap_setresuid().

[Andrew Bartlett]

On Sat, 2011-10-08 at 09:44 +0200, Andreas Schneider wrote:
> On Saturday 08 October 2011 10:42:45 Andrew Bartlett wrote:
> > On Fri, 2011-10-07 at 12:05 +0200, Andreas Schneider wrote:
> > > - Log -----------------------------------------------------------------
> > > commit 4493c578b0da44ae2100cc0d4d6acc714bf39a3f
> > > Author: Andreas Schneider <asn at samba.org>
> > > Date:   Fri Oct 7 10:30:23 2011 +0200
> > > 
> > >     uid_wrapper: Add uwrap_setresuid().
> > >     
> > >     Autobuild-User: Andreas Schneider <asn at cryptomilk.org>
> > >     Autobuild-Date: Fri Oct  7 12:04:05 CEST 2011 on sn-devel-104
> > 
> > Andreas,
> 
> Andrew, 
> 
> > It's really great to see UID wrapper being ported into the source3 code,
> > but I just wanted to mention that this seems to have broken the Solaris
> > build.
> > 
> > http://build.samba.org/build.cgi/build/2830602b39d10d5637469a8039ab51ee7329f
> > ad5
> > 
> > I'm sure the fix is pretty simple, I just wanted to bring it to your
> > attention.
> 
> there is more stuff broken than I thought, and I think I've fixed it now.
> 
> http://git.samba.org/?p=asn/samba.git;a=shortlog;h=refs/heads/s3-uid-wrapper
> 
> I just wanted that someone looks over it before I push it.
> 

Thanks.  I'm OK with these patches, except for 
http://git.samba.org/?p=asn/samba.git;a=commitdiff;h=17890a7e46b5227f4fa24c8326a4a13421d0edaa

The problem I have this this patch is if overriding the get/set uid
functions requires that we include a particular header, but the build
can continue without that header specified, we can get in a lot of
trouble quickly.  We should ensure that we do not obtain the system
prototypes for the replaced functions except via the header that has the
uid_wrapper replacements.

If we don't, we risk subtle, painful to debug issues in our test
environment (the same applies for socket_wrapper, and it is from that
experience that I give this warning).

I do realise this is difficult with geteuid() being defined via
unistd.h, but this is yet another reason why all Samba code should only
include system/ headers, not system headers directly.

Andrew Bartlett

-- 
Andrew Bartlett                                http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org