[SLL] Rant: ATA-over-Ethernet 0x88a2

[David J. Pfaltzgraff]

> Andrew Sweger wrote:
>> I'm not sure how you get a box to route Ethernet frames (with
>> type 0x88A2) to a userland process.
>
And Jeffrey Siegal responded:
> You can do this with libpcap.
>
It's been a while since I looked into this and I no longer have the
technical library available since I got laid off, but I did some googling
and found this link http://standards.ieee.org/regauth/ethertype/eth.txt
which interestingly enough has an entry at 88A2 for Coraid Inc. with the
protocol listed as being unavailable. Hmmm, the picture gets curiouser and
curiouser!

So, even though their type may be IEEE registered, it would appear that
they may be holding the protocol cards close to the chest.

Anyway, to answer the main question, somewhere in the bowels of the
protocol stack, there is a point where the kernel looks at the ethernet
type and decides as to whether or not this is IP traffic. At this point,
if the type is 0x88A2 control would be handed over to the AoE modules. I
guess libpcap may be one way to do this, but it shouldn't be necessary to
go into userland.

Only more musings...
Dave