[cifs-protocol] MS-SMB2: Create replay and Persistent Handle

[Ralph Boehme]

Hi dochelp,

I'm currently trying to understand the following behaviour related to 
create-replay observed against a Windows Server:

1. establish SMB3 connection
2. open a Persistent Handle
3. disconnect
4. reconnect
5. replay the create
6. write
7. replay the create again

The last step fails with STATUS_FILE_NOT_AVAILABLE which I can't align 
with the docs.

3.3.5.13 Receiving an SMB2 WRITE Request has

---8<---
If Open.IsPersistent is FALSE and Open.IsReplayEligible is TRUE, the 
server MUST set Open.IsReplayEligible to FALSE.
---8<---

so, as Open.IsPersistent is TRUE, Open.IsReplayEligible should be kept 
as TRUE.

Then CREATE processing 3.3.5.9 Receiving an SMB2 CREATE Request should 
apply:

---8<---
If the server implements the SMB 3.x dialect family and all of the 
following conditions are TRUE, the server MUST look up an Open in 
GlobalOpenTable where Open.IsReplayEligible is TRUE and
Open.CreateGuid matches the CreateGuid in the 
SMB2_CREATE_DURABLE_HANDLE_REQUEST_V2

...

If an Open is found, the server MUST perform the following:

...

- Construct the create response from Open, as specified in the
   "Response Construction" phase; the remaining create processing
   MUST be skipped.
---8<---

See attached network trace "ph-replay.pcap".

If I do the same but change the second replay from step 7 to a "normal" 
CREATE, that returns successful and just opens a second handle on the 
file (trace "ph-replay-once.pcap").

If I do the same with just a Durable Handles in step 2 instead of a PH 
and a replay in step 7, the replay in step 7 is "ignored" and treated as 
a new open so I get a second handle (trace "ph-durable.pcap").

*scratches head*

Can you explain this? Am I missing something in the docs? Maybe some 
interaction with ChannelSequence?

Thanks!
-slow
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