[cifs-protocol] SR# 117072516091337 :SMB2 ECHO request

[Jeff McCashland]

Hi Andreas,

My suggestion below was rejected as inappropriate for section 2, since it isn't a MUST rule. In fact, it is felt that the documentation covers the issue as the server processing rules for every SMB2 command (except NEGOTIATE and SESSION_SETUP) specify verifying the SessionId with the single exception of ECHO. We don't document what isn't done, just what we do. By implication, SessionID can be 0 for ECHO (unless the message is signed).

Hope that helps!

Best regards,
Jeff McCashland | Senior Escalation Engineer | Microsoft Protocol Open Specifications Team 
Phone: +1 (425) 703-8300 x38300 | Hours: 9am-5pm | Time zone: (UTC-08:00) Pacific Time (US and Canada)
Local country phone number found here: http://support.microsoft.com/globalenglish | Extension 1138300
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-----Original Message-----
From: Andreas Schneider [mailto:asn at samba.org] 
Sent: Monday, July 31, 2017 1:19 AM
To: Jeff McCashland <jeffm at microsoft.com>
Cc: cifs-protocol <cifs-protocol at lists.samba.org>; MSSolve Case Email <casemail at microsoft.com>
Subject: Re: SR# 117072516091337 :SMB2 ECHO request

On Thursday, 27 July 2017 21:25:51 CEST Jeff McCashland wrote:
> Hi Andreas,

Hi Jeff,

> Normally, this type of information would go into the processing rules 
> for the Client (Section 3.2). However, the gist of what I explained 
> below is that SMB2 doesn't have any rules for the client to process 
> the ECHO command. The client is free to use and process ECHO as 
> needed, as long as the structure in section 2.2 is met.
> 
> We could add something like:
> 
> 2.2.1.1	SMB2 Packet Header - ASYNC
> SessionId (8 bytes): Uniquely identifies the established session for 
> the command. This field MUST be set to 0 for an SMB2 NEGOTIATE Request 
> (section
> 2.2.3) and for an SMB2 NEGOTIATE Response (section 2.2.4). SessionId 
> MAY be set to 0 for an SMB2 ECHO Request (section 2.2.28) and for an 
> SMB2 ECHO Response (section 2.2.29).
> 
> 2.2.1.2	SMB2 Packet Header - SYNC
> SessionId (8 bytes): Uniquely identifies the established session for 
> the command. This field MUST be set to 0 for an SMB2 NEGOTIATE Request 
> (section
> 2.2.3) and for an SMB2 NEGOTIATE Response (section 2.2.4). SessionId 
> MAY be set to 0 for an SMB2 ECHO Request (section 2.2.28) and for an 
> SMB2 ECHO Response (section 2.2.29).
> 
> Would that be helpful?


I think that's perfect.


Thanks,


	Andreas


-- 
Andreas Schneider                   GPG-ID: CC014E3D
Samba Team                             asn at samba.org
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