udpproxy

Documentation

Overview

Package udpproxy provides an API for proxying UDP messages.

Index

• type Backend
  • func NewBackend(name string, addr string, scheduler Scheduler) (*Backend, error)
  • func (be *Backend) CreateConnection() (*net.UDPConn, error)
  • func (be *Backend) Send(msg []byte, sender *net.UDPAddr, fe *Frontend) error
  • func (be Backend) String() string
  • func (be *Backend) Touch()
• type Frontend
  • func NewFrontend(name, addr string, sched Scheduler) (*Frontend, error)
  • func (fe *Frontend) AddBackend(name, addr string) (*Backend, error)
  • func (fe *Frontend) ClearTouch()
  • func (fe *Frontend) Close()
  • func (fe *Frontend) Multicast(msg []byte, sender *net.UDPAddr)
  • func (fe *Frontend) RemoveUntouched()
  • func (fe *Frontend) RoundRobin(msg []byte, sender *net.UDPAddr)
  • func (fe *Frontend) Serve()
  • func (fe *Frontend) String() string
• type Proxy
  • func NewProxy() *Proxy
  • func (proxy *Proxy) AddFrontend(name, addr string, sched Scheduler) (*Frontend, error)
  • func (proxy *Proxy) AddOrReplaceFrontend(name, addr string, sched Scheduler) (*Frontend, error)
  • func (proxy *Proxy) Dump()
  • func (proxy *Proxy) Quit()
  • func (proxy *Proxy) Serve()
• type Scheduler
  • func (s Scheduler) String() string
• type Session

Types

type Backend

type Backend struct {
	Name             string
	Addr             *net.UDPAddr
	MessageSentCount uint
	MessageRecvCount uint
	Responder        chan []byte
	Touched          bool
}

Backend is the UDP backend

func NewBackend

func NewBackend(name string, addr string, scheduler Scheduler) (*Backend, error)

NewBackend spawns a new UDP backend.

func (*Backend) CreateConnection

func (be *Backend) CreateConnection() (*net.UDPConn, error)

CreateConnection spawnes a new UDP connection for given Backend.

func (*Backend) Send

func (be *Backend) Send(msg []byte, sender *net.UDPAddr, fe *Frontend) error

Send sends a single UDP message to this backend.

func (Backend) String

func (be Backend) String() string

func (*Backend) Touch

func (be *Backend) Touch()

Touch touches the given backend.

type Frontend

type Frontend struct {
	Name            string
	Conn            *net.UDPConn
	Scheduler       Scheduler
	Backends        []*Backend
	ResponseTimeout time.Duration
}

Frontend represents a UDP frontend

func NewFrontend

func NewFrontend(name, addr string, sched Scheduler) (*Frontend, error)

NewFrontend spawns a new UDP frontend.

func (*Frontend) AddBackend

func (fe *Frontend) AddBackend(name, addr string) (*Backend, error)

AddBackend extends given UDP Frontend with a new backend.

func (*Frontend) ClearTouch

func (fe *Frontend) ClearTouch()

ClearTouch clears out any touch-flags on all backends to this frontend.

func (*Frontend) Close

func (fe *Frontend) Close()

Close releases underlying sockets to given UDP frontend.

func (*Frontend) Multicast

func (fe *Frontend) Multicast(msg []byte, sender *net.UDPAddr)

Multicast sends the given message to this fronend to all backends.

func (*Frontend) RemoveUntouched

func (fe *Frontend) RemoveUntouched()

RemoveUntouched kills all backends that haven't been touched with Touch().

func (*Frontend) RoundRobin

func (fe *Frontend) RoundRobin(msg []byte, sender *net.UDPAddr)

RoundRobin sends the given message in round-robin fasion to exactly one backend.

func (*Frontend) Serve

func (fe *Frontend) Serve()

Serve serves given UDP frontend on current thread. Blocking.

func (*Frontend) String

func (fe *Frontend) String() string

String high-level view of this object as string.

type Proxy

type Proxy struct {
	// listen on downstreams and pass them upstream
	Frontends map[string]*Frontend
	// contains filtered or unexported fields
}

Proxy represents a generic UDP proxy for many UDP frontends

func NewProxy

func NewProxy() *Proxy

NewProxy spawns a new UDP proxy.

func (*Proxy) AddFrontend

func (proxy *Proxy) AddFrontend(name, addr string, sched Scheduler) (*Frontend, error)

AddFrontend does what it says ;-)

func (*Proxy) AddOrReplaceFrontend

func (proxy *Proxy) AddOrReplaceFrontend(name, addr string, sched Scheduler) (*Frontend, error)

AddOrReplaceFrontend does what it says. ;-)

func (*Proxy) Dump

func (proxy *Proxy) Dump()

Dump dumps the UDP proxy to stdout.

func (*Proxy) Quit

func (proxy *Proxy) Quit()

Quit triggers a termination of Serve()

func (*Proxy) Serve

func (proxy *Proxy) Serve()

Serve serves all frontends in backend and waits for them to terminate.

type Scheduler

type Scheduler int

Scheduler algorithm to use for proxying the UDP message.

const (
	// RoundRobin is the round-robin scheduler
	RoundRobin Scheduler = 1

	// Multicast (aka. fanout) scheduler. sends message to *all* backends.
	Multicast Scheduler = 2
)

func (Scheduler) String

func (s Scheduler) String() string

type Session

type Session struct {
	LastActive  time.Time
	Backend     *Backend
	RequestBuf  string
	ResponseBuf string
}

Session represents a UDP communication session