[Samba] Strange ID-Mapping behavior

Stefan Schäfer ml at fsproductions.de
Mon May 2 14:08:47 UTC 2016


Hi Mathias,

greping in the output of "net cache list" shows:

Key: IDMAP/GID2SID/20513         Timeout: Mon May  9 07:29:11 2016       
Value: S-1-5-21-1891182457-2156988848-2018633412-513
Key: IDMAP/GID2SID/100   Timeout: Mon May  9 07:29:32 2016 Value: 
S-1-5-21-1891182457-2156988848-2018633412-513
Key: IDMAP/SID2XID/S-1-5-21-1891182457-2156988848-2018633412-513 
Timeout: Mon May  9 07:29:32 2016       Value: 100:G


There are both values, the correct and the wrong one. Before I clear the 
cache, the question is: where could the wrong value come from?

Stefan


Am 02.05.2016 um 15:25 schrieb mathias dufresne:
> Hey,
>
> id mapping is accessible from net command:
> net cache list
>
> you can also clean that cache:
> net cache flush
>
> After flushing the cache your users and groups having uidNumber and/or
> gidNumber should work as expected (ie using their AD declared uid/gid).
>
> Cheers,
>
> mathias
>
> 2016-05-02 15:18 GMT+02:00 Achim Gottinger <achim at ag-web.biz>:
>
>> Sounds like there is an old entry in idmap.ldb. You can delete that entry
>> if you use rfc3207.
>> On my environment i had alot of old user entrys in idmap.ldb whom i had
>> moved to rfc3207 mapping.
>> With 4.1 this did not matter but with 4.2 samba sometimes picks the values
>> from idmap.ldb.
>>
>> achim
>>
>>
>> Am 02.05.2016 um 14:31 schrieb Stefan Schäfer:
>>
>>> Hi list,
>>>
>>> on one of our servers I found a strange id-mapping behavior. The server
>>> acts as an AD-DC and fileserver. We user the sernet-samba packages in
>>> version 4.2.9 on openSUSE leap 42.1.
>>>
>>> We use the rfc3207 extension for Posix attributes. Every group has a full
>>> set of posix-attributes. Our gidNumbers are calculated by RID plus 20000.
>>>
>>> If i ask for id-mappings, "wbinfo" shows for all groups the correct
>>> mapping instead of the group "domain users". This group is mapped to
>>> gitNumber 100, this is the group "users" in /etc/passwd.
>>>
>>> wbinfo --sids-to-unix-ids S-1-5-21-1891182457-2156988848-2018633412-513
>>> S-1-5-21-1891182457-2156988848-2018633412-513 -> gid 100
>>>
>>> For all other Groups it looks like:
>>>
>>> wbinfo --sids-to-unix-ids S-1-5-21-1891182457-2156988848-2018633412-514
>>> S-1-5-21-1891182457-2156988848-2018633412-514 -> gid 20514
>>>
>>> A look inside the LDAP DIT shows that the attribute "gidNumber" for
>>> "domain users" is set corectly to 20513.
>>>
>>> Here is what testparm -v shows:
>>> ...
>>>          idmap backend = tdb
>>>          idmap cache time = 604800
>>>          idmap negative cache time = 120
>>>          idmap uid =
>>>          idmap gid =
>>>          template homedir = /home/%D/%U
>>>          template shell = /bin/false
>>>          winbind separator = \
>>>          winbind cache time = 300
>>>          winbind reconnect delay = 30
>>>          winbind request timeout = 60
>>>          winbind max clients = 200
>>>          winbind enum users = No
>>>          winbind enum groups = No
>>>          winbind use default domain = No
>>>          winbind trusted domains only = No
>>>          winbind nested groups = Yes
>>>          winbind expand groups = 0
>>>          winbind nss info = template
>>>          winbind refresh tickets = No
>>>          winbind offline logon = No
>>>          winbind normalize names = No
>>>          winbind rpc only = No
>>>          create krb5 conf = Yes
>>>          ncalrpc dir = /var/run/samba/ncalrpc
>>>          winbind max domain connections = 1
>>>          winbindd socket directory = /var/run/samba/winbindd
>>>          winbindd privileged socket directory =
>>> /var/lib/samba/winbindd_privileged
>>>          winbind sealed pipes = Yes
>>> ....
>>>          winbindd:use external pipes = true
>>>          idmap_ldb:use rfc2307 = yes
>>>          idmap config * : backend = tdb
>>> ...
>>>
>>> Has anybody an idea how I can fix this wrong idmapping?
>>>
>>> Other servers with the same setup didn't show this behavior.
>>>
>>> Regards
>>>
>>> Stefan
>>>
>>
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-- 
www.invis-server.org

Stefan Schäfer
Ludwigstr. 1-3
63679 Schotten




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