[ofa-general] RE: CM goes to timewait state without waiting for disconnect reply

[Sean Hefty]

> In the spec, a normal flow to close a connection is
> at the client side: State "Established" ---- send DREQ --->
> State "DREQ sent" --- receive DREP ---> State "TimeWait"  --->
> State "Idle"

Yes - the CM kernel code follows this state machine. 

> According to the code and tests I did, it seems that ib_cm doesn't
> wait for DREP and goes directly from "DREQ sent" into "TimeWait".

This can happen in specific situations, such as errors, if the user destroys the
cm_id without waiting for the DREP (treated as a DREQ timeout), or if both sides
initiate a DREQ.

> I think that this is a bug, am I right?

I don't see that the code follows the behavior that you're describing.

In ib_send_cm_dreq(), the cm_id state changes to DREQ_SENT.

In cm_drep_handler() (called when a DREP is received), the cm_id state is
verified to be DREQ_SENT, then transitioned to TIMEWAIT.

If you can describe the test details more, I can try to find the most likely
code path that's being hit.  It's possible that you're hitting one of the
situations mentioned above.

- Sean