Re: iSCSI: using the C bit

[Bill Studenmund <wrstuden@wasabisystems.com>]

On Thu, 16 Jan 2003, Eddy Quicksall wrote:

> I want to be sure I understand the use of the C bit in a login. It seems to
> me that the initiator could split a key into two parts: 1st part at the end
> of request A and 2nd part at the beginning of request A+1.
>
> e.g., the end of request A (with C bit set) could be "Immediate" and the
> beginning of request A+1 could be "Data=yes" (the full key=value pair being
> "ImmediateData=yes").
>
> If this is done, the target will not process the partial key and may send
> his own key saying "ImmediateData=no". But, the initiator has already

No! While the partial process part is correct, if the C bit is set, you
can't send anything back.

It's ok to process keys as they come in, but you can't answer them or make
offers if the C bit was set.

> constructed the negotiation and request A+1 would violate the protocol
> because ImmediateData has already been negotiated.
>
> Comments?

The kind of case you describe is exactly why we have the C bit. Its
presence indicates that the sender wasn't able to fit everything it wanted
to say in one packet, so wait for more.

Take care,

Bill