[openib-general] [PATCH] [CM] add private data comparison to match REQs with listens

[Caitlin Bestler]

Fab Tillier wrote:
>> From: Caitlin Bestler [mailto:caitlinb at broadcom.com]
>> Sent: Friday, December 02, 2005 10:59 AM
>> 
>> Just listen on the Service ID / Port and let the ULP sort them out by
>> destination IP address.
> 
> That only works if there is a single kernel module providing the
> extra checks. Multiple user-mode ULPs cannot do the checking in
> user-mode - the checking must be done in the kernel to figure out
> which user-mode client to hand the request to.
> 
> I think putting in restrictions to the comparisons possible
> is fine, as the functionality of having the CM facilitate
> some sort of filtering is useful.
> 
> - Fab

Filtering between multiple kernels is fine, but it does
not involve the API. Basically if you are filtering amongst
multiple kernels then the Hypervisor is doing it, not any
user-mode client or even the individual kernels.

Within the context of a single Guest OS, I do not seed the
need to have multiple listens on the same Service ID / TCP
Port number for a given network interface.

In that context the more common usage is to have the destination
address select the *content* that will be served, not the
service that will be selected. (Or put another way, the
class of the daemon object being connected with is a
constant  -- only the instance data is different). For
those uses the number of virtual servers can be very
large, literally thousands. The filtering/selection is
best left to the content-serving daemon itself.