[PATCH] libnfsidmap: Don't fail when no domain is set

[J. Bruce Fields]

On Fri, Jul 11, 2008 at 06:12:54AM -0400, Steve Dickson wrote:
> 
> A while back I had a complaint that idmapper *always* gets
> the uid/gid mapping wrong because the default value defined
> in the 'Domain' field (in /etc/idmapd.conf) is never correct.
> 
> The person also noticed that by commenting out the Domain 
> fields caused the mappings to be correct, since DNS was used 
> to obtain the domain. 
> 
> But then it was noticed when the domain can not be gotten from
> the idmapd.conf or DNS, idmapper crashes which does seem too
> robust... imho... 
> 
> The first patch comments out the 'Domain' field  in idmapd.conf.
> The second patch  sets the 'default_domain' variable in libnfsidmap.c to 
> "localdomain" when there is not a domain  defined in /etc/idmapd.conf 
> and a domain name can not be obtained from DNS.

Seems reasonable, but you probably want to apply those patches in the
other order.  (Fix the bug before changing the configuration in a way
that may trigger the bug.)

--b.

> Of course using
> "localdomain" as the domain will cause all mapping to be map to
> the 'Nobody-User' user but better than having idmapper crash, imho...  
> 
> So these patches do two things, allows mappings to be correct "right out of the box"
> when DNS is set up correctly and stops idmapper from dying when there
> is no domain name set.
> 
> Signed-off-by: Steve Dickson <steved at redhat.com>
> 
> diff -up libnfsidmap-0.20/idmapd.conf.orig libnfsidmap-0.20/idmapd.conf
> --- libnfsidmap-0.20/idmapd.conf.orig	2006-08-14 17:19:45.000000000 -0400
> 
> +++ libnfsidmap-0.20/idmapd.conf	2008-07-11 05:37:58.000000000 -0400
> 
> @@ -1,7 +1,7 @@
> 
>  [General]
> 
>  #Verbosity = 0
> 
> -# The following should be set to the local NFSv4 domain name (REQUIRED)
> 
> -Domain = local.domain.edu
> 
> +# The following should be set to the local NFSv4 domain name
> 
> +#Domain = local.domain.edu
> 
>  
> 
>  [Mapping]
> 
>  
> 
> diff -up libnfsidmap/libnfsidmap.c.orig libnfsidmap/libnfsidmap.c
> --- libnfsidmap/libnfsidmap.c.orig	2006-09-05 10:09:00.000000000 -0400
> +++ libnfsidmap/libnfsidmap.c	2008-07-11 05:16:45.000000000 -0400
> @@ -54,6 +54,10 @@
>  /* forward declarations */
>  int set_trans_method(char *);
>  
> +#ifndef IDMAPD_DEFAULT_DOMAIN
> +#define IDMAPD_DEFAULT_DOMAIN "localdomain"
> +#endif
> +
>  static char *default_domain;
>  
>  #ifndef PATH_IDMAPDCONF
> @@ -109,10 +113,12 @@ int nfs4_init_name_mapping(char *conffil
>  		dflt = 1;
>  		ret = domain_from_dns(&default_domain);
>  		if (ret) {
> -			IDMAP_LOG(0, ("libnfsidmap: Unable to determine "
> -				  "a default nfsv4 domain; consider "
> -				  "specifying one in idmapd.conf\n"));
> -			return ret;
> +			IDMAP_LOG(1, ("libnfsidmap: Unable to determine "
> +				  "the NFSv4 domain; Using '%s' as the NFSv4 domain "
> +				  "which means UIDs will be mapped to the 'Nobody-User' "
> +				  "user defined in %s\n", 
> +				  IDMAPD_DEFAULT_DOMAIN, PATH_IDMAPDCONF));
> +			default_domain = IDMAPD_DEFAULT_DOMAIN;
>  		}
>  	}
>  	IDMAP_LOG(1, ("libnfsidmap: using%s domain: %s\n",
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