In case we add a new program in the future (we did that in the past and
we are going to do it again soon) current daemon will behave badly with
new client that wants to use the new program. Before the RPC rewrite we
used to just send an error reply to any request with unknown program.
With the RPC rewrite in 0.9.3 the daemon just closes the connection
through which such request was sent. This patch fixes this regression.
To facilitate creation of new daemons providing XDR RPC services,
pull a lot of the libvirtd daemon code into a set of reusable
objects.
* virNetServer: A server contains one or more services which
accept incoming clients. It maintains the list of active
clients. It has a list of RPC programs which can be used
by clients. When clients produce a complete RPC message,
the server passes this onto the corresponding program for
handling, and queues any response back with the client.
* virNetServerClient: Encapsulates a single client connection.
All I/O for the client is handled, reading & writing RPC
messages.
* virNetServerProgram: Handles processing and dispatch of
RPC method calls for a single RPC (program,version).
Multiple programs can be registered with the server.
* virNetServerService: Encapsulates socket(s) listening for
new connections. Each service listens on a single host/port,
but may have multiple sockets if on a dual IPv4/6 host.
Each new daemon now merely has to define the list of RPC procedures
& their handlers. It does not need to deal with any network related
functionality at all.
