Ogo

An OpenFlow Network Controller in Go.

You can find an example application which allows hosts to communicate on a single OpenFlow switch in ogo.go. Find full package docs below.

Documentation

Discourse

The Basic Application

All applications must implement the ogo.Application interface.

type Application interface {
  InitApplication(args map[string]string)
  Name() string
  Receive()
}

Use the InitApplication to recieve command line arguments. The Name function should return a string that will be used to identify your application. Use the Receive function to listen on any channels that you have subscribed to.

Registering your Application

In order for your application to recieve OpenFlow messages from connected switches it must be registered with Ogo.

ctrl.RegisterApplication( new(OgoApplication) )

Subscribing to OpenFlow Messages

Use ogo.SubscribeTo(ofp10.T_*) to get an ofp10.Msg chan.

echoRequestChan := ogo.SubscribeTo(ofp10.T_ECHO_REQUEST)

Acting on Messages

The function Receive() is required for all Applications. Use this function to listen for messages on your subscription channels.

(app *OgoApplication) Receive() {
for {
    select {
      case msg := <-app.echoRequestChan:
        fmt.Println("Received an EchoRequest message from:", msg.DPID)
      case msg := <-app.anotherChan:
        fmt.Println("Received some other message from:", msg.DPID)
    }
  }
}

A Simpler API

Ogo plans to do the heavy lifting to make building network applications easy.

Working with OpenFlow Switches

/* If switch dpid is known, returns its OFPSwitch struct. The
switch is not guaranteed to be connected to Ogo. */
core.Switch(dpid string) (sw OFPSwitch)

/* Return an array of all known switches as OFPSwitch structs. */
core.Switches() (sw []OFPSwitch)