> From: Caitlin Bestler [mailto:[EMAIL PROTECTED] > Sent: Wednesday, August 24, 2005 11:14 AM > > On 8/24/05, Fab Tillier <[EMAIL PROTECTED]> wrote: > > > From: Roland Dreier [mailto:[EMAIL PROTECTED] > > > Sent: Wednesday, August 24, 2005 10:16 AM > > > > > > Fab> Knowledge of actual IP addresses would be up to the consumer. > > > Fab> However, the IB CM can facilitate checks by allowing the user > > > Fab> to specify an offset and length in the private data to match > > > Fab> to for incoming requests. > > > > > > This seems too complex and at the same time too limited to me. For > > > one thing -- although I think ATS should die -- this doesn't support > > > ATS reverse lookups. > > > > I think if all ULPs provide their source and destination IP in the private > > data, you can eliminate the reverse lookup altogether. A simple forward > > lookup is all that's needed to validate that the source GID in the REQ > > matches the reported source IP in the private data. The forward lookup > > could be done via ATS or via ARP, but the CM doesn't need to care which > > method is used. > > That is not an option. > > The applications are expecting source/destination network addresses > that come from a network layer, not from the peer application. IP has > no problem meeting this requirement. This is an IB problem that needs > to be solved within the scope of IB without changing any ULPs.
If the app wants to use source/destination network addresses, there isn't a problem. The problem is the app wants to use IP addresses, which are *not* network addresses in IB. So the app needs to decide between one of two things - be aware of IB network addresses, or provide meaning to IP addresses over IB. The latter can't be done reliably under the covers - ATS reverse lookups won't tell you the IP the source actually used, and there's no way to do so without either using private data in the CM REQ or requiring a 1:1 mapping of IB:IP addresses. The 1:1 IB:IP mapping is not feasible, so the only way to know what IP address the application used is to embed that into the private data. I would expect protocols that try to use IP as their addressing would accommodate this in their IB usage, just like SDP accommodates it in the hello message. - Fab _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
