help constructing event_ctx for dcerpc handler

[Amin Azez]

I'm struggling to find examples populating the event_ctx struct passed
to dcerpc_pipe_connect_b() and dcerpc_pipe_connect().

I want to be able to use async handlersin vfs_proxy for the proxy rpc
and also for it's smb connection without one blocking the other.

I've read events.[ch], composite.[ch] (and most files that use
dcerpc_pipe_connect* with non-null event context, but that is generally
provided through too many levels of indirection by the caller) and
although very interesting it's hard to draw the final understanding
needed from those.

I've been able to conclude that there is or ought to be a generic rpc
event handler which relates incoming packets to queued async structs and
then calls a specific callback to match the specific responded RPC. (And
this is what the smb handlers do)... and yet although vfs_proxy.h
(copied from vfs_cifs.h) has a ntvfs->ctx->event_ctx, but again the path
from the packet being received to an async handler is such that I've not
been able to relate the call-stack to anything in ntvfs->ctx->event_ctx
(yet).

I've been at this for a few hours, and I'm still going but thought it
worth the time to ask.

Sam