[openib-general] RDMA connection and address translation API

[Roland Dreier]

    Fab> Why can't the IPV field be ignored?  If a listen wants only
    Fab> IPV4 addresses, it would specify a 16-byte compare buffer
    Fab> with the first 12 bytes zero, the next 4 filled with the IPV4
    Fab> address, and would set the offset to that of the hello
    Fab> message's destination address (32).

Yes, you're right for SDP.  I guess if we're comfortable mandating
that all protocols put their source and destination IPs in the private
data for the IB case, then this works.  Of course it's somewhat
awkward to pass this information into the transport-neutral CM API but
I think this can be worked around.

    Roland> What makes it really ugly is that it's perfectly
    Roland> reasonable for one consumer to listen to a service at
    Roland> 192.168.11.12 and another consumer to listen to the same
    Roland> service at 192.168.98.99.  How do we handle this in the IB
    Roland> case??

    Fab> As long as the service IP address (the local address on the
    Fab> listening side) is always advertised in the same place in the
    Fab> private data, this isn't a problem.  The compare lengths and
    Fab> offsets would be identical for both services, but the compare
    Fab> buffer contents would differ.  Did I miss what you were
    Fab> getting at?

No, I think I confused myself.  As long as the CM can get at the IP
information, it can figure out which consumer is which.

 - R.