[openib-general] Re: Some Initial RMPP Wire Observations

[Sean Hefty]

Hal Rosenstock wrote:
> OK that answers the ACK formatting but not whether an ACK is correct in
> this case.
> 
> o13-21.1.15 states that if a status code is received with an RMPPType
> value other than those it applies to, the Receiver shall discard the
> packet, terminate the protocol,and issue an RMPP ABORT packet with
> status code "Illegal Status".
> 
> The receiver flow diagram for MAD OK indicates other checks are
> appropriate.

I think what's necessary is for the DATA MAD to be rejected.  This check 
is missing, but easily added.  (I was deferring some of this until 
STOP/ABORT are implemented.)  So... I think that the ACK code may be 
correct, but checks done earlier in the receive path should prevent this 
type of DATA MAD from reaching the ACK code.


>>>In the last segment, it appears that the pad is not cleared. This again
>>>shouldn't matter but I didn't dig out what the spec says here.
>>
>>Not sure which field you're referring to here.
> 
> I'm referring to the transferred data beyond the end of the payload
> length in the last segment. I'm not sure there is a requirement to do
> anything with this on the transmit side.

Got ya...  The contents of the MAD data is the responsibility of the 
sender.  Note that ib_create_send_mad() clears the MAD memory, so if 
that call is used, the pad will be cleared.

- Sean