[Samba] Domain trusts "forgetting" trusted users

[Gaiseric Vandal]

And as I dig further into this:

after the cache time expires the idmap_cache.tbd file is updated, and 
more specifically the SID-to-ID entries get marked as "expired."

I have two samba servers configured-  one as the PDC, one as the BDC, 
both using the LDAP backend for everything.

The PDC currently has "idmap cache time = 604800" in smb.conf  (should 
be a week.)
The BDC smb.conf was set to  "idmap cache time = 900" (15 min.)


So on the BDC "getent passwd" no longer returns winbind users.  I  
updated the BDC smb.conf to "idmap cache time = 604800", deleted the 
idmap_cache.tbd and winbind_cache.tdb and restarted winbind.


A new idmap_cache.tbd is created but it already shows the entries as 
"expired."     Which makes me think that there is some other file 
somewhere were the samba server records when the cached expires-  and 
since since the winbind entries in ldap are older than that time,  it 
will automatically negatively cache them.  The only way to reload them 
is to delete the entries in ldap.

If I knew what file to delete I could have a nightly cron job that 
deleted any local cache files and restarted winbind.


Thanks




On 11/02/09 14:28, Gaiseric Vandal wrote:
> Upon further testing I find that the passwd and group info for the
> trusted domain get cached once, and one time only.  When the cache
> expires, "getent passwd" and "getent group" no longer return users
> from the trusted domain.
>
>
> By default, "idmap cache time=900" (15 min.)   If I increased this to
> 7200, then the caching was good for two hours (and not more.)
>
> The timestamp on  /var/samba/locks/idmap_cache.tdb file does get
> updated frequently -  at least every 20 minutes while I try "getent
> passwd."    idmapd_cache.tdb does have entries for the remote users.
>
>
>
> nscd is not running.
>
> Thoughts?
>
> Thanks.
>
>
> ---------- Forwarded message ----------
> From: Gaiseric Vandal<gaiseric.vandal at gmail.com>
> Date: Thu, Oct 29, 2009 at 1:30 PM
> Subject: Domain trusts "forgetting" trusted users
> To: samba at lists.samba.org
>
>
> I am running Samba ver 3.0.33 on Solaris 10 (sparc) as a PDC with LDAP
> for the backend for both samba and unix accounts.
>
> I have also set up a trust with an Windows domain- lets call it
> WINDOMAIN- (the PDC for the Windows domain is Win 2003 but is in
> mixed mode for backwards compat.) The SAMBA domain trusts the WINDOWS
> domain, not not vice versa.
>
> I had also tried setting up trusts with another, test domain (lets
> call it TESTDOMAIN.)
>
> I have winbind enabled. Initially idmap entries were stored in the
> local tdb backend. I switched this to ldap (wanted idmappings with
> in the domain to be consistent across member servers, and wanted to
> add a BDC.)
>
>
>
>
>
>
> smb.conf includes
>
> ----------------------------------------------------------------------------------------------
>
> passdb backend = ldapsam:ldap://ldap1.mydomain.com
> ldap suffix=o=mydomain.com
> ldap user suffix=ou=people
> ldap group suffix=ou=smb_groups
> ldap machine suffix=ou=machines
> ldap admin dn="cn=Directory Manager"
> ldap ssl = no
> ldap passwd sync = no
> ldap idmap suffix=ou=idmap
>
> winbind enum users = Yes
> winbind enum groups = no
> winbind use default domain = no
> winbind trusted domains only = no
>
> #ldap time out default is 15 sec
> ldap timeout=30
>
> # idmap domains = WINDOMAIN, TESTDOMAIN
> idmap domains = WINDOMAIN
>
>
> idmap config WINDOMAIN:backend = ldap
> idmap config WINDOMAIN:readonly = no
> idmap config WINDOMAIN:default=no
> idmap config WINDOMAIN:ldap_base_dn = ou=windomain,ou=idmap,o=mydomain.com
> idmap config WINDOMAIN:ldap_user_dn = cn=Directory Manager
> idmap config WINDOMAIN:ldap_url =ldap1.mydomain.com
> idmap config WINDOMAIN:range = 30000-39999
>
>
> #idmap config TESTDOMAIN:backend = ldap
> #idmap config TESTDOMAIN:readonly = no
> #idmap config TESTDOMAIN:default=no
> #idmap config TESTDOMAIN:ldap_base_dn =ou=testdomain,ou=idmap,o=mydomain.com
> #idmap config TESTDOMAIN:ldap_user_dn = cn=Directory Manager
> #idmap config TESTDOMAIN:ldap_url =ldap1.mydomain.com
> #idmap config TESTDOMAIN:range = 40000-49999
>
>
>
> idmap alloc backend = ldap
> idmap alloc config:ldap_base_dn = ou=alloc,ou=idmap,o=mydomain.com
> idmap alloc config:ldap_user_dn = cn=Directory Manager
> idmap alloc config:ldap_url = ldap1.mydomain.com
> idmap alloc config:range = 70000 - 79999
>
>
>
> ----------------------------------------------------------------------------------------------
>
>
> getting the correct (or mostly correct syntax) took a little while.
> /etc/nsswitch.conf is configured for winbind.
>
> When I first run "wbinfo -u" and "wbinfo -g", samba would populate
> entries for the WINDOMAIN account in
> windomain,ou=idmap,o=mydomain.com. The id's would be in the 70000
> range not the 30000 range- which is fine with me since entries for
> each domain were still in the correct ldap container.
>
> "getent passwd" and "getent group" would show the WINDOMAIN domain
> accounts. Everything would be fine for several days. However, after
> a few days, getent commands no longer showed the WINDOMAIN accounts.
>
> The only solution would be to stop windbind, delete the idmap entries
> from ldap, restart winbind and let the entries repopulate.
>
>
> I am unclear on if the "idmap config SOMEDOMAIN:range" setting for
> each domain should be within the "idmap alloc config:range"
>
> The syntax for this seems to change with different versions of samba.
>
> Any thoughts?
>
> Thanks
>