# $Source: /opt/cvs/samba/smbldap-tools/INFRA,v $
#
## Some notes about the architecture


Global Architecture for smbdlap-tools
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smbldap-tools help you manage users and groups for Unix and Samba,
using LDAP. They may be used in any context, and are kept relatively
simplier enought to let you customize them to you needs.

They need the following objectClasses to work:
 . sambaAccount: from samba.schema for Samba 2.2 branch
 . posixAccount and posixGroup : from nis.schema
 . organizationalUnit and dcObject: from core.schema

They will probably use in a near future some additional objectClasses
to support : 
 . mail features (sendmail/postfix/qmail/courier).
 . conform to RFC2307 best practices (and so some maps too like merging
   Netbios computers (sambaAccounts) with ipHosts

For ease of visualization of the LDAP objects by human standards, we
used a DIT like this one :
 . dc=IDEALX,dc=org : the company/organization suffix
	. ou=Users : to store users accounts
	. ou=Computers : to store computers accounts
	. ou=Groups : to store system groups
Of course, you're free to use a different naming scheme and DIT (see
smbldap_conf.pm).


Built in groups initial population 
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smbldap-populate.pl populate the LDAP directory with some built in groups 
using gidNumber according to Well Know RID of Windows NT4 Srv. In fact, As
far a Samba 2.2.x is concerned, only the 'Domain Admins' (gidNumber 512) have 
real inpact on the Samba and Windows population. To activate this group as 
the Domain Administrators Group, use the following smb.conf directive (see 
man smb.conf for more):

	domain admin group = " @"Domain Admins" "

However, to make pdb_ldap accept bind without being uid=0, a quick and
dirty patch must be applied to 2.2.4 (see samba-2.2.4-ldapbindnotuid0.patch).
This patch is Q&D because the check is there because Samba store admin 
credentials to establish the LDAP connection. The uid == 0 check was to 
ensure that a normal user could not get write access to the LDAP backend.
A more logical situation should be done for 2.2.5 by checking if the user
is a member of the domain admin group (reported to Jerremy and Gerald 
2002-05-28).

Other built in groups are really cosmetic ones with Samba 2.2.x. We did not
removed them because one of these days, we whish to use Samba 3.0 where 
Windows Group Support should be operational.

Why these specific gidNumbers ?
It's about unix/windows mapping of numerical ids with Samba. Ids below 1024 
are NT special ids. In fact, 512 is the RID (Windows uid/gid) for the 
"Domain Administrators" NT group. The magic number is found in Samba sources 
and possibly other Samba/Windows documentations.

The goal is to have a set of Unix users who are Domain Administrators and can 
modify Samba datas (eg. LDAP content), with commandline tools or within 
Windows via Samba.

Say you want to add a NT4 ws to an NT domain (controlled by a samba/ldap  
server). You give the domain administrator's login and password in the 
appropriate ws settings, then the ws contacts the samba server, which checks 
the credentials and use them as unix user to run the smbldap-tools (if I 
remember). Giving 512 as a RID to a LDAP entry marks it as a domain admin   
for Samba (thus Windows). Using nss_ldap, you also have an account with
gid 512.


Known BUGS and WORKAROUND used
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The 2.2.2 has at least a bug : rid/primaryGroupID are read as hex in LDAP,
but written as decimal. Fixed in CVS by reading as decimal. By default
smbldap-useradd.pl writes decimal to LDAP. Use -x to support the odd
behaviour.

The samba-2.2.4-ldapbindnotuid0.patch is not a perfect solution however
as the check is there because Samba store admin credentials to establish the 
LDAP connection. The uid == 0 check was to ensure that a normal user could 
not get write access to the LDAP backend. A more logical situation should be 
done for 2.2.5 by checking if the user is a member of the domain admin group 
(reported to Jerremy and Gerald 2002-05-28).

# - The End