RE: [[PATCH v1] 16/37] [CIFS] SMBD: Post a SMBD message with no payload

From: Long Li
Date: Mon Aug 14 2017 - 18:51:10 EST




> -----Original Message-----
> From: Tom Talpey
> Sent: Monday, August 14, 2017 12:00 PM
> To: Long Li <longli@xxxxxxxxxxxxx>; Christoph Hellwig <hch@xxxxxxxxxxxxx>
> Cc: Steve French <sfrench@xxxxxxxxx>; linux-cifs@xxxxxxxxxxxxxxx; samba-
> technical@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: RE: [[PATCH v1] 16/37] [CIFS] SMBD: Post a SMBD message with no
> payload
>
> > -----Original Message-----
> > From: linux-cifs-owner@xxxxxxxxxxxxxxx [mailto:linux-cifs-
> > owner@xxxxxxxxxxxxxxx] On Behalf Of Long Li
> > Sent: Monday, August 14, 2017 2:20 PM
> > To: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> > Cc: Steve French <sfrench@xxxxxxxxx>; linux-cifs@xxxxxxxxxxxxxxx;
> > samba- technical@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: RE: [[PATCH v1] 16/37] [CIFS] SMBD: Post a SMBD message with
> > no payload
> >
> > > > Implement the function to send a SMBD message with no payload.
> > > > This is
> > > required at times when we want to extend credtis to server to have
> > > it continue to send data, without sending any actual data payload.
> > >
> > > Shouldn't this just be implemented as a special case in the version
> > > that posts data?
> >
> > It uses a different packet format "struct smbd_data_transfer_no_data".
> > I can restructure some common code to share between packet sending
> functions.
>
> The SMB Direct keepalive is just a Data Transfer Message with no payload
> (MS-SMBD section 2.2.3) and the SMB_DIRECT_RESPONSE_REQUESTED flag
> possibly set. I don't see any need to define a special structure to describe
> this?

Data Transfer Message has the following extra fields at the end of an empty packet.

__le32 padding;
char buffer[0];

I agree with you those can be merged to a special structure case. Will make the change.

>
> Tom.