Re: [PATCH] Return failure in getnetgrent only when all netgroups have been searched (#17363)

["Carlos O'Donell" <carlos at redhat dot com>]

On 09/08/2014 01:14 PM, Siddhesh Poyarekar wrote:
> Hi,
> 
> The netgroups lookup code fails when one of the groups in the search
> tree is empty.  In such a case it only returns the leaves of the tree
> after the blank netgroup.  This is because the line parser returns a
> NOTFOUND status when the netgroup exists but is empty.  The
> __getnetgrent_internal implementation needs to be fixed to try
> remaining groups if the current group is entry.  This patch implements
> this fix.  Tested on x86_64.
> 
> Siddhesh
> 
> 	[BZ #17363]
> 	* inet/getnetgrent_r.c (__internal_getnetgrent_r): Try next
> 	group if the current group is empty.
> 
> diff --git a/inet/getnetgrent_r.c b/inet/getnetgrent_r.c
> index f6d064d..e101537 100644
> --- a/inet/getnetgrent_r.c
> +++ b/inet/getnetgrent_r.c
> @@ -297,7 +297,10 @@ __internal_getnetgrent_r (char **hostp, char **userp, char **domainp,
>      {
>        status = DL_CALL_FCT (*fct, (datap, buffer, buflen, &errno));
>  
> -      if (status == NSS_STATUS_RETURN)
> +      if (status == NSS_STATUS_RETURN
> +	  /* The service returned a NOTFOUND, but there are more groups that we
> +	     need to resolve before we give up.  */

OK but suggest expanded comment:

/* An empty group returns NOTFOUND, but there may be more groups that we
   need to resolve before we can return NOTFOUND.  */

> +	  || (status == NSS_STATUS_NOTFOUND && datap->needed_groups != NULL))
>  	{
>  	  /* This was the last one for this group.  Look at next group
>  	     if available.  */
> 

OK.

Returning NSS_STATUS_NOTFOUND for an empty group seems reasonable from the
internals interface perspective, and the code in __internal_getnetgrent_r
doesn't handle it properly.

Even if NSS_STATUS_NOTFOUND is returned, we should keep parsing because
there might be other groups to consider.

Looks good to me.

Cheers,
Carlos.