Re: [PATCH] Cygwin: Allow to set SO_PEERCRED zero (v2)

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

On Dec  7 16:30, Corinna Vinschen via Cygwin-patches wrote:
> On Dec  7 02:29, Mark Geisert wrote:
> > The existing code errors as EINVAL any attempt to set a value for
> > SO_PEERCRED via setsockopt() on an AF_UNIX/AF_LOCAL socket.  But to
> > enable the workaround set_no_getpeereid behavior for Python one has
> > to be able to set SO_PEERCRED to zero.  Ergo, this patch.  Python has
> > no way to specify a NULL pointer for 'optval'.
> > 
> > This v2 of patch allows the original working (i.e., allow NULL,0 for
> > optval,optlen to mean turn off SO_PEERCRED) in addition to the new
> > working described above.  The sense of the 'if' stmt is reversed for
> > readability.
> > 
> > ---
> >  winsup/cygwin/fhandler_socket_local.cc | 10 +++++++---
> >  1 file changed, 7 insertions(+), 3 deletions(-)
> > 
> > diff --git a/winsup/cygwin/fhandler_socket_local.cc b/winsup/cygwin/fhandler_socket_local.cc
> > index c94bf828f..964f3e819 100644
> > --- a/winsup/cygwin/fhandler_socket_local.cc
> > +++ b/winsup/cygwin/fhandler_socket_local.cc
> > @@ -1430,10 +1430,14 @@ fhandler_socket_local::setsockopt (int level, int optname, const void *optval,
> >  	     FIXME: In the long run we should find a more generic solution
> >  	     which doesn't require a blocking handshake in accept/connect
> >  	     to exchange SO_PEERCRED credentials. */
> > -	  if (optval || optlen)
> > -	    set_errno (EINVAL);
> > -	  else
> > +	  /* Temporary: Allow SO_PEERCRED to only be zeroed. Two ways to
> > +	     accomplish this: pass NULL,0 for optval,optlen; or pass the
> > +	     address,length of an '(int) 0' set up by the caller. */
> > +	  if ((!optval && !optlen) ||
> > +		(optlen == (socklen_t) sizeof (int) && !*(int *) optval))
> >  	    ret = af_local_set_no_getpeereid ();
> > +	  else
> > +	    set_errno (EINVAL);
> >  	  return ret;
> >  
> >  	case SO_REUSEADDR:
> > -- 
> > 2.29.2
> 
> Pushed

I created new developer snapshots for testing.


Corinna