Ethereal-dev: Re: [Ethereal-dev] SCSI SPC-3 commands vs SPC-2 ...

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Date: Mon, 11 Mar 2002 22:05:13 -0800
Hi Richard,

On further investigating, I did find that there is something called
variable-length CDBs which you're alluding to. I thought that you were
interested in decoding OSD and since OSD has a special peripheral device type,
I suggested my first alternative.

It is quite easy to add a decoder for the overall variable-length CDB. However
to decode each of the service actions for such CDBs is another beast. I can
send a patch to handle variable-length CDBs quite soon, in about an hour or
so. I don't have any traces with variable-length CDB and so cannot test the
code. 

Dinesh
Richard Sharpe writes:
 > On Mon, 11 Mar 2002 ddutt@xxxxxxxxx wrote:
 > 
 > > If you're attempting to decode OSD, the Inquiry response contains the
 > > peripheral type as 0x11 (byte 0, bits 0-4). You can save this information in
 > > the SCSI device type block and then decode later commands based on this.
 > 
 > Hi Dinesh ....
 > 
 > I would like to check my [somewhat limited] understanding of the SCSI spec 
 > and SPC-3 vs SBC etc.
 > 
 > It seems to me that variable sized CDBs should have 0x7F as their OpCode 
 > byte, and should be distinguished from each other through the Action 
 > field. This field is a 16-bit field.
 > 
 > If so, I will probably make some changes to the SCSI dissector, and then 
 > we can look to dissecting OSD.
 > 
 > Is this correct?
 > 
 > > Dinesh
 > > Richard Sharpe writes:
 > >  > On Tue, 12 Mar 2002, Richard Sharpe wrote:
 > >  > 
 > >  > > Hi,
 > >  > > 
 > >  > > The current iSCSI dissector calls the SCSI dissector, which only 
 > >  > > understands SPC-2 SCSI commands, it seems.
 > >  > > 
 > >  > > I need to be able to dissect OSD commands, which are carried in a CDB with 
 > >  > > an SPC-3 Variable Length CDB indicator (0x7F).
 > >  > 
 > >  > Hmmm, the problem I am experiencing is because Ethereal's SCSI dissector 
 > >  > currently only understands SPC-2, SBC-2, and SSC-2. If the CDB Operation 
 > >  > Code is not found in the SPC-2 command set, tben the dissector searches 
 > >  > among the SBC-2 command set ... Which is where 0X7F is found :-(
 > >  > 
 > >  > So, I need some way to tell what type of device we are talking about. 
 > >  > Better check what the iSCSI spec says. If it says SPC-3, then I can pass 
 > >  > an arg to the SCSI dissector telling it what command set to use.
 > >  > 
 > >  > > What I am interested in knowing is: Is there an easy way to determine 
 > >  > > whether or not a stream is using SPC-3 or what? Is it carried in the iSCSI 
 > >  > > PDU or logon or something like that?
 > >  > > 
 > >  > > 
 > >  > 
 > >  > -- 
 > >  > Regards
 > >  > -----
 > >  > Richard Sharpe, rsharpe@xxxxxxxxxx, rsharpe@xxxxxxxxx, 
 > >  > sharpe@xxxxxxxxxxxx
 > >  > 
 > >  > 
 > >  > _______________________________________________
 > >  > Ethereal-dev mailing list
 > >  > Ethereal-dev@xxxxxxxxxxxx
 > >  > http://www.ethereal.com/mailman/listinfo/ethereal-dev
 > >  > 
 > > 
 > > 
 > 
 > -- 
 > Regards
 > -----
 > Richard Sharpe, rsharpe@xxxxxxxxxx, rsharpe@xxxxxxxxx, 
 > sharpe@xxxxxxxxxxxx
 > 
 > 

-- 
Out beyond the ideas of right-doing and wrong-doing there is a field. I'll meet
you there. - Rumi