[cifs-protocol] SR# 117060115827644 - RE: Question about DRS client behaviour with linked attributes
Will.Gregg at microsoft.com
Thu Jun 1 09:12:58 UTC 2017
Thank you for raising your question regarding DRS Client Behaviors to the Open Specifications team. I have created a support case, SR# 117060115827644, to track your issue. A member of the Open Specification support team will be contacting you regarding your question.
Will Gregg | escalation engineer | open specifications
From: Tim Beale [mailto:timbeale at catalyst.net.nz]
Sent: Wednesday, May 31, 2017 7:18 PM
To: Interoperability Documentation Help <dochelp at microsoft.com>; cifs-protocol at lists.samba.org
Subject: Question about DRS client behaviour with linked attributes
We're trying to add DRS GET_TGT support to Samba and have a question about the behaviour of linked attributes. We noticed that you can sometimes get linked attributes that span a partition.
For example you can have an object in the Configuration partition with a linked attribute to an object in the Domain partition:
serverReference: CN=RWDC,OU=Domain Controllers,DC=SAMDOM,DC=EXAMPLE,DC=COM
And you can also have an object in the Domain partition with a linked attribute to an object in the Configuration partition:
dn: CN=RWDC,CN=Topology,CN=Domain System Volume,CN=DFSR-GlobalSettings,CN=System,DC=SAMDOM,DC=EXAMPLE,DC=COM
From what I could see from testing, when the DRS_GET_TGT flag is set in the ReplicateNCRequestMsg, Windows does not resolve a target object that is in another partition.
This results in a cyclical dependency between the partitions being replicated, E.g. you can't commit all the linked attributes in the Domain partition until all the objects in the Configuration partition have been received, but you can't commit all the linked attributes in the Configuration partition until all the objects in the Domain partition have been received. This problem could be resolved if you manage to replicate the target object before the link is replicated.
My question is: how does the Windows replication behaviour resolve this problem?
- Does this mean the client always has to replicate the partitions in parallel? i.e. it can't replicate them in series because it can't commit an entire partition until it has received portions of another partition.
- What happens when the client encounters a linked attribute with an unknown target object? ProcessLinkValue() in the MS-DRSR seems to imply the client will ignore it (if it's already tried with GET_TGT). So how does the client ensure that it receives the linked attribute eventually?
Thanks for your help.
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