[openib-general] [PATCH] libibsa: userspace SA query and multicast support

[Sean Hefty]

Roland Dreier wrote:
> What's the plan for how this would be used?  We can't let unprivileged
> userspace processes talk to the SA, because they could cause problems
> like deleting someone else's multicast group membership.  And I don't
> think we want to try to do some elaborate filtering in the kernel, do we?

The ibv_sa_send_mad() routine can only be used to issue the following methods:

GET, SEND, GET_TABLE, GET_MULTI, and GET_TRACE_TABLE

I do check for this in the kernel, but that is the extent of any filtering 
that's done.  Multicast operations must go through the multicast join / free 
calls, which drop into the kernel to interface with the ib_multicast module.

I would expect that other SET / DELETE type operations would be treated similar 
to how multicast is handled.

I'm expecting that the labs will use at least the multicast interfaces based on 
e-mail conversations, but without path record query support, the userspace CM 
interface isn't all that useful.

- Sean