MessageDispatcher¶

//
// Facilitates the interconnection of applications, protocols, and network interfaces,
// dispatching messages and packets among them. It supports diverse configurations, ranging from
// layered architectures with distinct message dispatchers for separate communication layers, to
// centralized structures where a single dispatcher manages connections to all components.
//
// Keeps track of four different mappings for dispatching messages and packets:
//  - network interface mapping specifies which gate should be used when dispatching towards a specific
//    network interface
//  - service mapping specifies which gate should be used when dispatching service data units (SDUs)
//    towards a specific protocol (e.g. IPv4 SDU, Ethernet SDU)
//  - protocol mapping specifies which gate should be used when dispatching protocol data units (PDUs)
//    towards a specific protocol (e.g. IPv4 PDU, Ethernet PDU)
//  - socket mapping specifies which gate should be used when dispatching towards a specific socket
//
// To configure the dispatch mechanism:
//  - protocol modules must register using the `registerService()` and/or `registerProtocol()` functions
//  - network interface modules must register using the `registerInterface()` function
//  - sockets must use the ~SocketReq or ~SocketInd tags when sending socket open/close commands
//  - manual configuration is also possible using the module's mapping parameters
//
// To use the dispatch mechanism, messages and packets must have a specific tag attached that defines the target:
//  - service or protocol targets can be specified using the ~DispatchProtocolReq tag
//  - network interface targets can be specified using the ~InterfaceReq tag
//  - socket targets can be specified using the ~SocketReq or ~SocketInd tags
//
// Automatically learned services, protocols, and network interfaces are shared among connected message dispatchers.
//
simple MessageDispatcher extends PacketProcessorBase
{
    parameters:
        string interfaceTableModule; // Module path to the ~InterfaceTable module
        bool forwardServiceRegistration = default(true);
        bool forwardProtocolRegistration = default(true);
        object interfaceMapping = default({}); // Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
        object serviceMapping = default({}); // Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
        object protocolMapping = default({}); // Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
        @class(MessageDispatcher);
        @display("i=-;b=100,5,,,,1;");
    gates:
        input in[];
        output out[];
}