[Samba] Rights issue on GPO

Rowland penny rpenny at samba.org
Sat Jun 25 08:24:27 UTC 2016


On 24/06/16 22:08, Achim Gottinger wrote:
>
>
> Am 24.06.2016 um 22:35 schrieb Achim Gottinger:
>>
>>
>> Am 24.06.2016 um 21:24 schrieb Rowland penny:
>>> On 24/06/16 19:47, lingpanda101 at gmail.com wrote:
>>>> On 6/24/2016 11:40 AM, mathias dufresne wrote:
>>>>>
>>>>>
>>>>> 2016-06-24 15:24 GMT+02:00 lingpanda101 at gmail.com 
>>>>> <mailto:lingpanda101 at gmail.com> <lingpanda101 at gmail.com 
>>>>> <mailto:lingpanda101 at gmail.com>>:
>>>>>
>>>>>     On 6/22/2016 12:21 PM, mathias dufresne wrote:
>>>>>
>>>>>         2016-06-22 16:37 GMT+02:00 L.P.H. van Belle <belle at bazuin.nl
>>>>>         <mailto:belle at bazuin.nl>>:
>>>>>
>>>>>             @Mathias,
>>>>>
>>>>>             Pretty strange then, running some years like this without
>>>>>             any problem.
>>>>>             Yes we had few problems with "rights" in sysvol, but i
>>>>>             fixed this all
>>>>>             outside linux, and with that i mean. Changed rights from
>>>>>             within windows or
>>>>>             added registry changes or patches, or a local clean up of
>>>>>             the policies.
>>>>>
>>>>>             At the install of my DC2 i also synced the idmap.ldb, and
>>>>>             then a
>>>>>             net idmap flush on both servers to make my both dc's 
>>>>> in sync.
>>>>>             And i keep it in sync with my rsync/unison setup.
>>>>>
>>>>>             All new added, but i'll keep an eye also in this and i'll
>>>>>             recheck my logs.
>>>>>             But i dont think i'll find anything here.
>>>>>             I'll keep notice on your "workaround".
>>>>>
>>>>>             Which backend are you using matias?
>>>>>             Mine : (idmap config NTDOMAIN : backend = ad)
>>>>>
>>>>>
>>>>>             Gr.
>>>>>
>>>>>             Louis
>>>>>
>>>>>
>>>>>         OK you keep idmap.ldb synched, that's what I missed until few
>>>>>         days and was
>>>>>         the reason that is was not working.
>>>>>         Our choice to give each and users and groups into AD some xID
>>>>>         is only to
>>>>>         avoid usage of mapping. I expect the synchronization of
>>>>>         idmap.ldb (if done
>>>>>         often enough) would be sufficient. But I don't always like
>>>>>         magic : )
>>>>>
>>>>>         Thank you for precisions !
>>>>>
>>>>>
>>>>>         Cheers all
>>>>>
>>>>>
>>>>>                 -----Oorspronkelijk bericht-----
>>>>>                 Van: samba [mailto:samba-bounces at lists.samba.org
>>>>> <mailto:samba-bounces at lists.samba.org>] Namens mathias
>>>>>
>>>>>             dufresne
>>>>>
>>>>>                 Verzonden: woensdag 22 juni 2016 15:31
>>>>>                 Aan: lingpanda101 at gmail.com
>>>>>                 <mailto:lingpanda101 at gmail.com>
>>>>>                 CC: samba
>>>>>                 Onderwerp: Re: [Samba] Rights issue on GPO
>>>>>
>>>>>                 @LPH van Belle
>>>>>                 I did tried (and still use) "acl_xattr:ignore system
>>>>>                 acls = yes" as shown
>>>>>                 on the first mail of that thread. And even using that
>>>>>                 rights errors on
>>>>>
>>>>>             GPO
>>>>>
>>>>>                 files _are_ an issue. Otherwise that thread won't 
>>>>> have
>>>>>                 been opened of
>>>>>                 course : )
>>>>>
>>>>>                 Regarding how we decided to workaround almost
>>>>>                 definitively with that was
>>>>>                 to
>>>>>                 give every users and groups in AD some xID, also 
>>>>> those
>>>>>                 in CN=Builtin and
>>>>>                 CN=Users. We also cleaned our idmap.ldb to keep 
>>>>> inside
>>>>>                 only special users
>>>>>                 /
>>>>>                 groups (as "local system" / S-1-5-18, "guests" /
>>>>>                 S-1-5-32-546...).
>>>>>                 We also add some rsync to keep idmap.ldb synchronized
>>>>>                 on all our DC, for
>>>>>                 these special items have same mapped xID in case they
>>>>>                 are used (and so
>>>>>                 mapped).
>>>>>
>>>>>                 Doing that id mapper has no reason to define by 
>>>>> itself
>>>>>                 some xID to users
>>>>>                 and groups contained into AD as they already have 
>>>>> some
>>>>>                 xID.
>>>>>
>>>>>                 Until now it seems to work fine...
>>>>>
>>>>>
>>>>>                 2016-06-22 15:09 GMT+02:00 lingpanda101 at gmail.com
>>>>>                 <mailto:lingpanda101 at gmail.com>
>>>>>                 <lingpanda101 at gmail.com 
>>>>> <mailto:lingpanda101 at gmail.com>>:
>>>>>
>>>>>                     On 6/22/2016 8:53 AM, mj wrote:
>>>>>
>>>>>
>>>>>                         On 06/22/2016 02:44 PM, 
>>>>> lingpanda101 at gmail.com
>>>>> <mailto:lingpanda101 at gmail.com> wrote:
>>>>>
>>>>>                             Why is is when I do a getfacl I do not 
>>>>> see
>>>>>                             the mapping of BUILTIN
>>>>>
>>>>>             like
>>>>>
>>>>>                             others?
>>>>>
>>>>>                         do you have winbind in /etc/nsswitch.conf?
>>>>>
>>>>>                         mj
>>>>>
>>>>>
>>>>>                     I also thought winbind was only necessary on
>>>>>                     member servers.
>>>>>
>>>>>                     --
>>>>>                     -James
>>>>>
>>>>>
>>>>>
>>>>>                     --
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>>>>>
>>>>>
>>>>>     If I assign every user a UID and select groups a GID by utilizing
>>>>>     rfc2307 on my DC's. Would I still benefit from keeping idmap.ldb
>>>>>     synchronized? I'm thinking XID's are obsolete at that point?
>>>>>
>>>>>
>>>>> Only users and groups in AD will avoid id mapper by that 
>>>>> workaround. But there are others accounts ("local system", 
>>>>> "guest", "local administrator"...) all these accounts exist on MS 
>>>>> Windows clients, and so they can all do stuff on Sysvol and so 
>>>>> they can all go through id mapper.
>>>>>
>>>>> So no. There no way (for me at least :) to totally avoid id mapper 
>>>>> and so you should keep idmap.ldb synched.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>     --     -James
>>>>>
>>>>>
>>>>>     --     To unsubscribe from this list go to the following URL 
>>>>> and read the
>>>>>     instructions: https://lists.samba.org/mailman/options/samba
>>>>>
>>>>>
>>>>
>>>> I'm in the process now of creating a script to sync idmap.ldb. Does 
>>>> anyone have one at the moment? Is it best practice to stop samba 
>>>> before replacing idmap.ldb on the additional DC's? My script will 
>>>> currently watch for any idmap.ldb changes and create a hot backup 
>>>> if a change is detected. It will then send to the other DC's via 
>>>> rsync. I'm thinking starting and stopping samba isn't ideal during 
>>>> production hours.
>>>>
>>>
>>> If you are running Samba >= 4.2.0 with the separate 'winbindd' 
>>> binary, there is no reason to sync idmap.ldb. Syncing idmap was/is 
>>> only required if you use 'winbind' that is built into the 'samba' 
>>> binary.
>>>
>>> Rowland
>>>
>>>
>> Hello Rowland,
>>
>> If you take an look on your sysvol rights there are two still 
>> unresoved groups SECURITY\Local System and SECURITY\Autheticated 
>> Users. These show up with gid's from idmap.ldb in the acl list and 
>> therefore can not be mapped during rsync. So at least these two 
>> groups need idntical mapping on all dc's. It is however not 
>> neccessary to keep idmap in sync as long as no ther security groups 
>> are used.
>>
>> achim~
>>
> To be more specific the groups belongig to "WellKnown Security 
> Principals" are not mapped. I called them security groups above.
> See here for an list:
> https://technet.microsoft.com/en-us/library/dn617202(v=ws.11).aspx#BKMK_AuthenticatedUser 
>
>

I know all of the above, and you seem to be using fixes that had to be 
used with a Samba 4 AD DC that used the 'winbind' part of the 'samba' 
binary.

When Samba 4.2.0 came out, 'winbind' was replaced with the separate 
'winbindd' binary (the same one used on a domain member). This means 
that, even though an AD object may be mapped to a number, the DC knows 
what AD object that is.

This means you do not need to sync idmap.ldb between DCs if you use 
Samba >= 4.2.0 with the separate 'winbindd' binary.

Rowland




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