To get the permissions of an object, combine the permissions
of the object and all the parent nodes up to the root.
This is necessary to enforce that a client can never see and
object id (in this case the parent id) it is not allowed to see.
Don't pass the ucred to the client construct, just set the properties
in the protocol.
Use the client properties to get ucred.
Add the security label to the client properties (from SO_PEERSEC)
Destroy all resources (except the core) for a client when it
does a hello. This typically needs to be done after passing the
connection fd from one client to another.
Add a function to recalculate all nodes associated with a driver by
iterating the graph for each driver node. We used to do this in an
incremental way, which is easy to join graph but expensive to
split.
A full scan simplifies some things and we can't avoid it when we
need to calculate latencies later. It will also simplifies assigning
master and slave roles to drivers when the graphs are joined/split.
When we link/unlink or add/remove nodes, recalc the graph.
Pass a message around to make things more extensible later.
Keep fds per message if we ever want to write individual
messages.
Pass number of fds in the message header. We might need this to
close the fds when the proxy is gone.
Add a node subscribe params method that automatically emits the new
params when they change so that we can avoid an enum_params.
Use this in the stream object.
Remove the control messages to update controls in stream, use the
set_param. This is more overhead but allows for notifications to other
clients.
Make it possible to update many controls in one go.
Make a get node method that binds to the server side node of the
client-node immediately. use this in the remote_export and always
return a node proxy.
Use the node proxy to get property updates and signal those in the
stream.
Output controls can be linked to many input controls and many input
controls can receive input from many output controls. Keep the control
link information inside the link.
