[Samba] New (4.18 provisioned) domain is missing id lookups from idmap.ldb

Mon Sep 4 20:50:56 UTC 2023

On 04-09-2023 22:26, Rowland Penny via samba wrote:
> On Mon, 4 Sep 2023 22:09:35 +0200
> Kees van Vloten via samba <samba at lists.samba.org> wrote:
>
>> Hi Team,
>>
>>
>> I am setting up a new AD-domain, the first DC is just operational and
>> some users and groups are created.
>>
>> This run on Debian 11, Samba 4.18.6 and it is set up with the same
>> (but evolved) Ansible code I used for my other domains (all of them
>> on different networks and independent of each other). The older
>> domains were initially set up with Samba 4.14 and another with 4.15
>> and upgraded many times since, the new setup with 4.18.6. In all
>> places gets installed from the same debian packages.
>>
>> Due to the repeatable Ansible setup the /etc/samba/smb.conf is
>> exactly the same (apart from the domain name etc.) on the existing
>> domains and the new domain. And all domains were provisioned with
>> '--use-rfc2307'.
>>
>> 'samba-tool processes | wc -l' is equal between old and new: 24
>> lines. And ps aux | grep winbindd also shows an equal number of
>> winbind processes.
>>
>> '/etc/nsswitch.conf' is also equal and includes winbind for passwd
>> and group.
>>
>>
>> Now the mystery starts: there is a difference in id (uid/gid) lookups
>> on a DC between the older domains and the new domain.
>>
>> It looks like the new domain is not querying
>> /var/lib/samba/private/idmap.ldb (but is does exist there), whereas
>> the older once are.
>>
>> As an example I tried: getent passwd '<DOMAIN-NAME>\domain admins'
>>
>> On the old domain(s) this results (as expected) in:
>>
>> OLDDOM\domain admins:*:3000004:3000004::/home/domain admins:/bin/bash
>>
>> But on the new domain the lookup has no result.
>>
>> The winbind logging is equally different, on the old domain (success):
>>
>> [2023/09/04 20:55:56.243929,  3]
>> ../../source3/winbindd/winbindd_misc.c:355(winbindd_interface_version)
>>     winbindd_interface_version: [nss_winbind (2502996)]: request
>> interface version (version = 32)
>> [2023/09/04 20:55:56.243999,  3]
>> ../../source3/winbindd/winbindd.c:497(process_request_send)
>>     process_request_send: [nss_winbind (2502996)] Handling async
>> request: GETPWNAM
>> [2023/09/04 20:55:56.244007,  3]
>> ../../source3/winbindd/winbindd_getpwnam.c:59(winbindd_getpwnam_send)
>>     [nss_winbind (2502996)] Winbind external command GETPWNAM start.
>>     Query username 'OLDDOM\domain admins'.
>> [2023/09/04 20:55:56.244312,  3]
>> ../../source3/winbindd/winbindd_getpwnam.c:149(winbindd_getpwnam_recv)
>>     Winbind external command GETPWNAM end.
>>     (name:passwd:uid:gid:gecos:dir:shell)
>>     OLDDOM\domain admins:*:3000004:3000004::/home/domain
>> admins:/bin/bash [2023/09/04 20:55:56.244322,  3]
>> ../../source3/winbindd/winbindd.c:564(process_request_done)
>>     process_request_done: [nss_winbind(2502996):GETPWNAM]: NT_STATUS_OK
>> [2023/09/04 20:55:57.091601,  3]
>> ../../source3/winbindd/winbindd_misc.c:355(winbindd_interface_version)
>>     winbindd_interface_version: [nss_winbind (2502997)]: request
>> interface version (version = 32)
>> [2023/09/04 20:55:57.091800,  3]
>> ../../source3/winbindd/winbindd.c:497(process_request_send)
>>     process_request_send: [nss_winbind (2502997)] Handling async
>> request: GETGROUPS
>> [2023/09/04 20:55:57.091817,  3]
>> ../../source3/winbindd/winbindd_getgroups.c:63(winbindd_getgroups_send)
>>     [nss_winbind (2502997)] Winbind external command GETGROUPS start.
>>     Searching groups for username 'root'.
>> [2023/09/04 20:55:57.093936,  3]
>> ../../source3/winbindd/winbindd_util.c:1736(lookup_usergroups_cached)
>>     : lookup_usergroups_cached
>> [2023/09/04 20:55:57.106212,  3]
>> ../../source3/winbindd/winbindd_getgroups.c:267(winbindd_getgroups_recv)
>>     Winbind external command GETGROUPS end.
>>     Received 2 entries.
>> [2023/09/04 20:55:57.106337,  3]
>> ../../source3/winbindd/winbindd_getgroups.c:272(winbindd_getgroups_recv)
>>     0: GID 10000
>> [2023/09/04 20:55:57.106344,  3]
>> ../../source3/winbindd/winbindd_getgroups.c:272(winbindd_getgroups_recv)
>>     1: GID 10019
>> [2023/09/04 20:55:57.106350,  3]
>> ../../source3/winbindd/winbindd.c:564(process_request_done)
>>     process_request_done: [nss_winbind(2502997):GETGROUPS]:
>> NT_STATUS_OK
>>
>> On the new domain (no result):
>>
>> [2023/09/04 20:54:18.579629,  3]
>> ../../source3/winbindd/winbindd_misc.c:355(winbindd_interface_version)
>>     winbindd_interface_version: [nss_winbind (43590)]: request
>> interface version (version = 32)
>> [2023/09/04 20:54:18.579686,  3]
>> ../../source3/winbindd/winbindd.c:497(process_request_send)
>>     process_request_send: [nss_winbind (43590)] Handling async
>> request: GETPWNAM
>> [2023/09/04 20:54:18.579701,  3]
>> ../../source3/winbindd/winbindd_getpwnam.c:59(winbindd_getpwnam_send)
>>     [nss_winbind (43590)] Winbind external command GETPWNAM start.
>>     Query username 'NEWDOM\domain admins'.
>> [2023/09/04 20:54:18.582975,  1]
>> ../../source3/winbindd/wb_queryuser.c:128(wb_queryuser_got_uid)
>>     XID type is 2, should be ID_TYPE_UID or ID_TYPE_BOTH.
>> [2023/09/04 20:54:18.582990,  1]
>> ../../source3/winbindd/winbindd_getpwnam.c:142(winbindd_getpwnam_recv)
>>     Could not convert sid S-1-5-21-435088123-233829246-2133031062-512:
>> NT_STATUS_NO_SUCH_USER
>> [2023/09/04 20:54:18.582995,  3]
>> ../../source3/winbindd/winbindd.c:564(process_request_done)
>>     process_request_done: [nss_winbind(43590):GETPWNAM]:
>> NT_STATUS_NO_SUCH_USER
>>
>> Another indication that /var/lib/samba/private/idmap.ldb is not used
>> comes from the group lookup of domain admins:
>>
>> getent group '<DOMAIN-NAME>\domain admins'
>>
>> Old domain: OLDDOM\domain admins:x:3000004: (3000004 is the xidNumber
>> in idmap.ldb)
>>
>> New domain: NEWDOM\domain admins:x:10001: (10001 is the gidNumber in
>> the ldap record of the group)
>>
>>
>> Would could cause this different behaviour (on these 2 very similar
>> environments)?
> You giving Domain Admins a gidNumber attribute, which by the way has
> just broken sysvol.
>
> Rowland
>
>
ok, it was worth testing your hypothesis:

# destroy domain:
dpkg -l | grep 4.18.6 | awk '{print $2}' | xargs apt-get -y purge
# everything including /var/lib/samba is removed

# rerun ansible playbook for samba_dc_install

getent group 'domain admins'
# no result

So no more gidNumber from the ldap group record, but nothing from 
idmap.ldb either :-(

- Kees.