Re: [PATCH 1/2] Teach clients to map numeric strings into valid uids and gids.

[Steve Dickson <SteveD@redhat.com>]

On 08/17/2010 04:27 PM, Trond Myklebust wrote:
> On Tue, 2010-08-17 at 15:38 -0400, Steve Dickson wrote:
>> When a server can not map a uid or gid they can send
>> an numeric string (one that does not include the @domain)
>> of the given id. When this occurs the client will can use
>> that numeric representation iff that id exists on the client.
>>
>> Signed-off-by: Steve Dickson <steved@redhat.com>
>> ---
>>  utils/idmapd/idmapd.c |   38 ++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 38 insertions(+), 0 deletions(-)
>>
>> diff --git a/utils/idmapd/idmapd.c b/utils/idmapd/idmapd.c
>> index 9ecab66..d6799c9 100644
>> --- a/utils/idmapd/idmapd.c
>> +++ b/utils/idmapd/idmapd.c
>> @@ -826,6 +826,21 @@ idtonameres(struct idmap_msg *im)
>>  		im->im_status = IDMAP_STATUS_SUCCESS;
>>  }
>>  
>> +static int
>> +alldigits(char *name)
>> +{
>> +	char *p = name;
>> +
>> +	if (name == NULL)
>> +		return 0;
>> +
>> +	while (*p != '\0') {
>> +		if (!isdigit(*p++))
>> +			return 0;
>> +	}
>> +	return 1;
>> +}
>> +
>>  static void
>>  nametoidres(struct idmap_msg *im)
>>  {
>> @@ -843,6 +858,18 @@ nametoidres(struct idmap_msg *im)
>>  		ret = nfs4_name_to_uid(im->im_name, &uid);
>>  		im->im_id = (u_int32_t) uid;
>>  		if (ret) {
>> +			/*
>> +			 * When a server sends numeric string that's
>> +			 * lacking the @domain part, and the uid exists
>> +			 * use the numeric string as the uid. 
>> +			 */
>> +			if (alldigits(im->im_name)) {
>> +				sscanf(im->im_name, "%u", &uid);
>> +				if (getpwuid(uid) != NULL) {
>> +					im->im_id = uid;	
>> +					break;
>> +				}
>> +			}
>>  			im->im_status = IDMAP_STATUS_LOOKUPFAIL;
>>  			im->im_id = nobodyuid;
>>  		}
>> @@ -851,6 +878,17 @@ nametoidres(struct idmap_msg *im)
>>  		ret = nfs4_name_to_gid(im->im_name, &gid);
>>  		im->im_id = (u_int32_t) gid;
>>  		if (ret) {
>> +			/*
>> +			 * Do the same type of mapping of a numeric string
>> +			 * sent as the gid.
>> +			 */
>> +			if (alldigits(im->im_name)) {
>> +				sscanf(im->im_name, "%u", &gid);
>> +				if (getgrgid(gid) != NULL) {
>> +					im->im_id = gid;
>> +					break;
>> +				}
>> +			}
>>  			im->im_status = IDMAP_STATUS_LOOKUPFAIL;
>>  			im->im_id = nobodygid;
>>  		}
> 
> Wouldn't it make more sense to put this into libnfsidmap instead?
I did think of that but since the nobody ids are being set here I 
figured I made the most sense to do here... plus this is pretty 
simple code why hide a way in the library and make it more 
difficult to debug... 

steved.