ogo

README

Ogo

An OpenFlow Network Controller written in Go.

A Basic Application

Register

To process OpenFlow messages register a function that returns a pointer to an existing or new Application struct.

func NewDemoInstance() interface{} {
  return &DemoInstance{}
}
controller.RegisterApplication(NewDemoInstance)

Receive

To receive OpenFlow messages, applications should implement the interfaces found in protocol/ofp10/interface.go or protocol/ofp13/interface.go.

func (b *DemoInstance) ConnectionUp(dpid net.HardwareAddr) {
  log.Println("Switch connected:", dpid)
}

func (b *DemoInstance) ConnectionDown(dpid net.HardwareAddr) {
  log.Println("Switch disconnected:", dpid)
}

func (b *DemoInstance) PacketIn(dpid net.HardwareAddr, pkt *ofp10.PacketIn) {
  log.Println("PacketIn message received from:", dpid)
}

Send

Any struct that implements util.Message can be sent to the switch. Only OpenFlow messages should be sent using OFSwitch.Send(m util.Message).

req := ofp10.NewEchoRequest()

// If switch dpid is known, returns its OFPSwitch struct. The
// switch is not guaranteed to have an active connection.
if sw, ok := ogo.Switch(dpid string); ok {
  sw.Send(req)
}

Documentation

Index

• Variables
• func NewInstance() interface{}
• func NewSwitch(stream *MessageStream, msg ofp10.SwitchFeatures)
• type ApplicationInstanceGenerator
• type BufferPool
  • func NewBufferPool() *BufferPool
• type Controller
  • func NewController() *Controller
  • func (c *Controller) Listen(port string)
  • func (c *Controller) RegisterApplication(fn ApplicationInstanceGenerator)
• type Link
• type LinkDiscovery
  • func NewLinkDiscovery() *LinkDiscovery
  • func (d *LinkDiscovery) Len() uint16
  • func (d *LinkDiscovery) MarshalBinary() (data []byte, err error)
  • func (d *LinkDiscovery) UnmarshalBinary(data []byte) error
• type MessageStream
  • func NewMessageStream(conn *net.TCPConn) *MessageStream
  • func (m *MessageStream) GetAddr() net.Addr
• type Network
  • func NewNetwork() *Network
• type OFSwitch
  • func Switch(dpid net.HardwareAddr) (*OFSwitch, bool)
  • func Switches() []*OFSwitch
  • func (sw *OFSwitch) AddInstance(inst interface{})
  • func (s *OFSwitch) DPID() net.HardwareAddr
  • func (s *OFSwitch) Link(dpid net.HardwareAddr) (l Link, ok bool)
  • func (s *OFSwitch) Links() []Link
  • func (sw *OFSwitch) Port(portNo uint16) (port ofp10.PhyPort, ok bool)
  • func (s *OFSwitch) Ports() []ofp10.PhyPort
  • func (s *OFSwitch) Send(req util.Message)
  • func (sw *OFSwitch) SetPort(portNo uint16, port ofp10.PhyPort)
• type OgoInstance
  • func (o *OgoInstance) ConnectionDown(dpid net.HardwareAddr)
  • func (o *OgoInstance) ConnectionUp(dpid net.HardwareAddr)
  • func (o *OgoInstance) EchoReply(dpid net.HardwareAddr)
  • func (o *OgoInstance) EchoRequest(dpid net.HardwareAddr)
  • func (o *OgoInstance) FeaturesReply(dpid net.HardwareAddr, features *ofp10.SwitchFeatures)
  • func (o *OgoInstance) PacketIn(dpid net.HardwareAddr, msg *ofp10.PacketIn)

Variables

var Applications []ApplicationInstanceGenerator

Functions

func NewInstance

func NewInstance() interface{}

OgoInstance generator.

func NewSwitch

func NewSwitch(stream *MessageStream, msg ofp10.SwitchFeatures)

Builds and populates a Switch struct then starts listening for OpenFlow messages on conn.

Types

type ApplicationInstanceGenerator

type ApplicationInstanceGenerator func() interface{}

type BufferPool

type BufferPool struct {
	Empty chan *bytes.Buffer
	Full  chan *bytes.Buffer
}

func NewBufferPool

func NewBufferPool() *BufferPool

type Controller

type Controller struct{}

func NewController

func NewController() *Controller

func (*Controller) Listen

func (c *Controller) Listen(port string)

func (*Controller) RegisterApplication

func (c *Controller) RegisterApplication(fn ApplicationInstanceGenerator)

Setup OpenFlow Message chans for each message type.

type Link

type Link struct {
	DPID      net.HardwareAddr
	Port      uint16
	Latency   time.Duration
	Bandwidth int
}

Internal representation of a network link. Can be used to describe the state of the link. Each switch maintains its own set of links.

type LinkDiscovery

type LinkDiscovery struct {
	SrcDPID net.HardwareAddr
	Nsec    int64 /* Number of nanoseconds elapsed since Jan 1, 1970. */
	// contains filtered or unexported fields
}

func NewLinkDiscovery

func NewLinkDiscovery() *LinkDiscovery

func (*LinkDiscovery) Len

func (d *LinkDiscovery) Len() uint16

func (*LinkDiscovery) MarshalBinary

func (d *LinkDiscovery) MarshalBinary() (data []byte, err error)

func (*LinkDiscovery) UnmarshalBinary

func (d *LinkDiscovery) UnmarshalBinary(data []byte) error

type MessageStream

type MessageStream struct {

	// OpenFlow Version
	Version uint8
	// Channel on which to publish connection errors
	Error chan error
	// Channel on which to publish inbound messages
	Inbound chan util.Message
	// Channel on which to receive outbound messages
	Outbound chan util.Message
	// Channel on which to receive a shutdown command
	Shutdown chan bool
	// contains filtered or unexported fields
}

func NewMessageStream

func NewMessageStream(conn *net.TCPConn) *MessageStream

Returns a pointer to a new MessageStream. Used to parse OpenFlow messages from conn.

func (*MessageStream) GetAddr

func (m *MessageStream) GetAddr() net.Addr

type Network

type Network struct {
	sync.RWMutex
	Switches map[string]*OFSwitch
}

A map from DPIDs to all Switches that have connected since Ogo started.

func NewNetwork

func NewNetwork() *Network

type OFSwitch

type OFSwitch struct {
	// contains filtered or unexported fields
}

func Switch

func Switch(dpid net.HardwareAddr) (*OFSwitch, bool)

Returns a pointer to the Switch mapped to dpid.

func Switches

func Switches() []*OFSwitch

Returns a slice of *OFPSwitches for operations across all switches.

func (*OFSwitch) AddInstance

func (sw *OFSwitch) AddInstance(inst interface{})

func (*OFSwitch) DPID

func (s *OFSwitch) DPID() net.HardwareAddr

Returns the dpid of Switch s.

func (*OFSwitch) Link

func (s *OFSwitch) Link(dpid net.HardwareAddr) (l Link, ok bool)

Returns the link between Switch s and the Switch dpid.

func (*OFSwitch) Links

func (s *OFSwitch) Links() []Link

Returns a slice of all links connected to Switch s.

func (*OFSwitch) Port

func (sw *OFSwitch) Port(portNo uint16) (port ofp10.PhyPort, ok bool)

Returns a pointer to the OfpPhyPort at port number from Switch s.

func (*OFSwitch) Ports

func (s *OFSwitch) Ports() []ofp10.PhyPort

Returns a slice of all the ports from Switch s.

func (*OFSwitch) Send

func (s *OFSwitch) Send(req util.Message)

Sends an OpenFlow message to this Switch.

func (*OFSwitch) SetPort

func (sw *OFSwitch) SetPort(portNo uint16, port ofp10.PhyPort)

type OgoInstance

type OgoInstance struct {
	// contains filtered or unexported fields
}

func (*OgoInstance) ConnectionDown

func (o *OgoInstance) ConnectionDown(dpid net.HardwareAddr)

func (*OgoInstance) ConnectionUp

func (o *OgoInstance) ConnectionUp(dpid net.HardwareAddr)

func (*OgoInstance) EchoReply

func (o *OgoInstance) EchoReply(dpid net.HardwareAddr)

func (*OgoInstance) EchoRequest

func (o *OgoInstance) EchoRequest(dpid net.HardwareAddr)

func (*OgoInstance) FeaturesReply

func (o *OgoInstance) FeaturesReply(dpid net.HardwareAddr, features *ofp10.SwitchFeatures)

func (*OgoInstance) PacketIn

func (o *OgoInstance) PacketIn(dpid net.HardwareAddr, msg *ofp10.PacketIn)