Description of problem:

[Note writing this bug against unclassified as cli is not listed in component]

In IPv6 address format, 00:00:00:00:00:00:00:00 is the valid ipv6 address which is best represented as "::". Setting the "00:00:00:00:00:00:00:00" ipv6 address for authentication of volume is successful but not "::". It complains that "::" is not a valid-internet address

Log Snippet:
============

[2012-08-23 17:39:42.565152] E [options.c:499:xlator_option_validate_addr_list] 0-vol1-server: option auth.addr./root/rahul/a.allow ::: '::' is not a valid internet-address-list
[2012-08-23 17:39:42.565212] W [options.c:773:xl_opt_validate] 0-vol1-server: validate of auth.addr./root/rahul/a.allow returned -1
[2012-08-23 17:39:42.565252] I [options.c:878:xlator_validate_rec] 0-vol1-server: option auth.addr./root/rahul/a.allow ::: '::' is not a valid internet-address-list



Version-Release number of selected component (if applicable):

[root@unused ~]# gluster --version
glusterfs 3.3.0rhs built on Aug 17 2012 07:06:59
Repository revision: git://git.gluster.com/glusterfs.git
Copyright (c) 2006-2011 Gluster Inc. <http://www.gluster.com>
GlusterFS comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of GlusterFS under the terms of the GNU General Public License.
[root@unused ~]# 

How reproducible:
1/1

Steps to Reproduce:
1. Set the volume authentication option as "gluster volume set vol1 auth.allow ::"
2. It reports the error
  
Actual results:

Console Snippet:
================

[root@unused ~]# gluster volume set vol1 auth.allow 0:0:0:0:0:0:0:0
Set volume successful
[root@unused ~]# gluster volume set vol1 auth.allow ::
option auth.addr./root/rahul/a.allow ::: '::' is not a valid internet-address-list
Set volume unsuccessful
[root@unused ~]# 



Expected results:

It should be successful as

[root@unused ~]# gluster volume set vol1 auth.allow ::
Set volume successful
[root@unused ~]# 

Additional info:

Tried following valid shortened notation with "::"

1. ::1 is successful
2. 1:: is unsuccessful
3. 1::1 is successful
4. :: is unsuccessful

I think following code in common-utils.c is causing the issue

valid_ipv6_address (char *address, int length, gf_boolean_t wildcard_acc)

        /* Check for compressed form */
        if (length <= 0 || tmp[length - 1] == ':') {
                ret = 0;
                goto out;
        }

In the above code we are checking tmp[length - 1], so in case of :: ":" is at the end of the array. Hence it fails for 1:: and ::