Messages in this thread |  | | | Date | Thu, 4 Feb 2010 23:16:21 +0000 | | From | Alan Cox <> | | Subject | Re: [PATCH] seastar - SeaStar Ethernet driver |
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> Ethernet Frame: [6 bytes h_dest][6 bytes h_source][2 bytes h_proto][data...] > SeaStar DG Message: [2 bytes length][1 byte MBZ][1 byte msg type (2 << 5) for IP)][data...] > > I think it would be possible to re-factor it so that the Ethernet frame > is encapsulated in its entirety within a seastar message, rather than > the current scheme of jamming the critical info from the Ethernet header > into the seastar datagram header. I will pursue that if you want... the > drawback is that it would break compatibility with Cray's existing > proprietary IP over SeaStar driver, making this driver pretty much > useless for the kinds of things us and others would like to do (e.g., > leave service nodes booted with Cray's proprietary software stack and > talking to compute nodes running this driver).
Perhaps it shouldn't be pretending to be an ethernet driver - that is sort of the root cause of all the confusion and the fact things like the bridging layer will try and grab it etc ? If it claimed to be a new hardware type you'd take a brief hit on getting the new hw type into the tools but it would mean
- tcpdump etc once coaxed would display seastar frames not fake ethernet - the config tools would actually report what it really was - non IP layers and userspace won't keep trying to do things you don't want (what does it do right now with vlans I wonder 8)) - there will be no ARP confusion
If it wants to stay compatible and pretend to be ethernet you probably need a message type for "encapsulated ethernet", you can then encapsulate anything not IP and stay compatible by keeping IP sent the way it is now ? Thats if it wants to in the first place.
Alan
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