(ITS#6017) Implement parentGUID or similar in OpenLDAP

[abartlet@samba.org]

Full_Name: Andrew Bartlett
Version: 2.4.15
OS: Fedora 9
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (59.167.251.137)


Samba4 would find it most helpful if OpenLDAP would be able to present an
operational attribute 'parentGUID' similar to the one that Windows 2008 has
implemented in AD.

http://msdn.microsoft.com/en-us/library/cc221277(PROT.13).aspx

Formalised details of the required semantics are not very clear at this point (I
will request clarification from Microsoft on this), but for now:

The root entries on a partition have no parentGUID

All other entries have a value parentGUID equal to the objectGUID of the parent

This value is available in search results if requested.

As Samba handles the translation from text to binary, feel free to use the
existing entryUUID formatting.

Implementing this would avoid Samba having to perform an auxillary search to
find this information, which should be very cheaply available to hdb when it is
resolving the DN. 

Thanks,

Andrew Bartlett

(Discussed with Howard Chu on #openldap-devel)