Add back the old tunnel interface

tunnel/default.go

@@ -1,79 +1,436 @@
 package tunnel
 
 import (
+	"crypto/sha256"
+	"errors"
+	"fmt"
 	"sync"
 
+	"github.com/google/uuid"
 	"github.com/micro/go-micro/transport"
+	"github.com/micro/go-micro/util/log"
 )
 
+// tun represents a network tunnel
 type tun struct {
+	options Options
+
 	sync.RWMutex
-	tr        transport.Transport
-	options   Options
+
+	// to indicate if we're connected or not
 	connected bool
-	closed    chan bool
+
+	// the send channel for all messages
+	send chan *message
+
+	// close channel
+	closed chan bool
+
+	// a map of sockets based on Micro-Tunnel-Id
+	sockets map[string]*socket
+
+	// outbound links
+	links map[string]*link
+
+	// listener
+	listener transport.Listener
 }
 
-func newTunnel(opts ...Option) Tunnel {
-	// initialize default options
-	options := DefaultOptions()
+type link struct {
+	transport.Socket
+	id string
+}
 
+// create new tunnel on top of a link
+func newTunnel(opts ...Option) *tun {
+	options := DefaultOptions()
 	for _, o := range opts {
 		o(&options)
 	}
 
-	// tunnel transport
-	tr := newTransport()
-
-	t := &tun{
-		tr:      tr,
+	return &tun{
 		options: options,
+		send:    make(chan *message, 128),
 		closed:  make(chan bool),
+		sockets: make(map[string]*socket),
+		links:   make(map[string]*link),
+	}
+}
+
+// getSocket returns a socket from the internal socket map.
+// It does this based on the Micro-Tunnel-Id and Micro-Tunnel-Session
+func (t *tun) getSocket(id, session string) (*socket, bool) {
+	// get the socket
+	t.RLock()
+	s, ok := t.sockets[id+session]
+	t.RUnlock()
+	return s, ok
+}
+
+// newSocket creates a new socket and saves it
+func (t *tun) newSocket(id, session string) (*socket, bool) {
+	// hash the id
+	h := sha256.New()
+	h.Write([]byte(id))
+	id = fmt.Sprintf("%x", h.Sum(nil))
+
+	// new socket
+	s := &socket{
+		id:      id,
+		session: session,
+		closed:  make(chan bool),
+		recv:    make(chan *message, 128),
+		send:    t.send,
+		wait:    make(chan bool),
 	}
 
-	return t
+	// save socket
+	t.Lock()
+	_, ok := t.sockets[id+session]
+	if ok {
+		// socket already exists
+		t.Unlock()
+		return nil, false
+	}
+	t.sockets[id+session] = s
+	t.Unlock()
+
+	// return socket
+	return s, true
 }
 
-// Id returns tunnel id
-func (t *tun) Id() string {
-	return t.options.Id
+// TODO: use tunnel id as part of the session
+func (t *tun) newSession() string {
+	return uuid.New().String()
 }
 
-// Options returns tunnel options
-func (t *tun) Options() Options {
-	return t.options
+// process outgoing messages sent by all local sockets
+func (t *tun) process() {
+	// manage the send buffer
+	// all pseudo sockets throw everything down this
+	for {
+		select {
+		case msg := <-t.send:
+			nmsg := &transport.Message{
+				Header: msg.data.Header,
+				Body:   msg.data.Body,
+			}
+
+			// set the tunnel id on the outgoing message
+			nmsg.Header["Micro-Tunnel-Id"] = msg.id
+
+			// set the session id
+			nmsg.Header["Micro-Tunnel-Session"] = msg.session
+
+			// send the message via the interface
+			t.RLock()
+			for _, link := range t.links {
+				link.Send(nmsg)
+			}
+			t.RUnlock()
+		case <-t.closed:
+			return
+		}
+	}
 }
 
-// Address returns tunnel listen address
-func (t *tun) Address() string {
-	return t.options.Address
+// process incoming messages
+func (t *tun) listen(link transport.Socket, listener bool) {
+	for {
+		// process anything via the net interface
+		msg := new(transport.Message)
+		err := link.Recv(msg)
+		if err != nil {
+			return
+		}
+
+		// first check Micro-Tunnel
+		switch msg.Header["Micro-Tunnel"] {
+		case "connect":
+			// assuming new connection
+			// TODO: do something with this
+			continue
+		case "close":
+			// assuming connection closed
+			// TODO: do something with this
+			continue
+		}
+
+		// the tunnel id
+		id := msg.Header["Micro-Tunnel-Id"]
+
+		// the session id
+		session := msg.Header["Micro-Tunnel-Session"]
+
+		// if the session id is blank there's nothing we can do
+		// TODO: check this is the case, is there any reason
+		// why we'd have a blank session? Is the tunnel
+		// used for some other purpose?
+		if len(id) == 0 || len(session) == 0 {
+			continue
+		}
+
+		var s *socket
+		var exists bool
+
+		// if its a local listener then we use that as the session id
+		// e.g we're using a loopback connecting to ourselves
+		if listener {
+			s, exists = t.getSocket(id, "listener")
+		} else {
+			// get the socket based on the tunnel id and session
+			// this could be something we dialed in which case
+			// we have a session for it otherwise its a listener
+			s, exists = t.getSocket(id, session)
+			if !exists {
+				// try get it based on just the tunnel id
+				// the assumption here is that a listener
+				// has no session but its set a listener session
+				s, exists = t.getSocket(id, "listener")
+			}
+		}
+
+		// no socket in existence
+		if !exists {
+			// drop it, we don't care about
+			// messages we don't know about
+			continue
+		}
+
+		// is the socket closed?
+		select {
+		case <-s.closed:
+			// closed
+			delete(t.sockets, id)
+			continue
+		default:
+			// process
+		}
+
+		// is the socket new?
+		select {
+		// if its new the socket is actually blocked waiting
+		// for a connection. so we check if its waiting.
+		case <-s.wait:
+		// if its waiting e.g its new then we close it
+		default:
+			// set remote address of the socket
+			s.remote = msg.Header["Remote"]
+			close(s.wait)
+		}
+
+		// construct a new transport message
+		tmsg := &transport.Message{
+			Header: msg.Header,
+			Body:   msg.Body,
+		}
+
+		// construct the internal message
+		imsg := &message{
+			id:      id,
+			session: session,
+			data:    tmsg,
+		}
+
+		// append to recv backlog
+		// we don't block if we can't pass it on
+		select {
+		case s.recv <- imsg:
+		default:
+		}
+	}
 }
 
-// Transport returns tunnel client transport
-func (t *tun) Transport() transport.Transport {
-	return t.tr
-}
+func (t *tun) connect() error {
+	l, err := t.options.Transport.Listen(t.options.Address)
+	if err != nil {
+		return err
+	}
+
+	// save the listener
+	t.listener = l
+
+	go func() {
+		// accept inbound connections
+		err := l.Accept(func(sock transport.Socket) {
+			// save the link
+			id := uuid.New().String()
+			t.Lock()
+			t.links[id] = &link{
+				Socket: sock,
+				id:     id,
+			}
+			t.Unlock()
+
+			// delete the link
+			defer func() {
+				t.Lock()
+				delete(t.links, id)
+				t.Unlock()
+			}()
+
+			// listen for inbound messages
+			t.listen(sock, true)
+		})
+
+		t.Lock()
+		defer t.Unlock()
+
+		// still connected but the tunnel died
+		if err != nil && t.connected {
+			log.Logf("Tunnel listener died: %v", err)
+		}
+	}()
+
+	for _, node := range t.options.Nodes {
+		c, err := t.options.Transport.Dial(node)
+		if err != nil {
+			log.Debugf("Tunnel failed to connect to %s: %v", node, err)
+			continue
+		}
+
+		err = c.Send(&transport.Message{
+			Header: map[string]string{
+				"Micro-Tunnel": "connect",
+			},
+		})
+
+		if err != nil {
+			continue
+		}
+
+		// process incoming messages
+		go t.listen(c, false)
+
+		// save the link
+		id := uuid.New().String()
+		t.links[id] = &link{
+			Socket: c,
+			id:     id,
+		}
+	}
+
+	// process outbound messages to be sent
+	// process sends to all links
+	go t.process()
 
-// Connect connects establishes point to point tunnel
-func (t *tun) Connect() error {
 	return nil
 }
 
-// Close closes the tunnel
+func (t *tun) close() error {
+	// close all the links
+	for id, link := range t.links {
+		link.Send(&transport.Message{
+			Header: map[string]string{
+				"Micro-Tunnel": "close",
+			},
+		})
+		link.Close()
+		delete(t.links, id)
+	}
+
+	// close the listener
+	return t.listener.Close()
+}
+
+// Close the tunnel
 func (t *tun) Close() error {
-	return nil
-}
+	t.Lock()
+	defer t.Unlock()
+
+	if !t.connected {
+		return nil
+	}
 
-// Status returns tunnel status
-func (t *tun) Status() Status {
 	select {
 	case <-t.closed:
-		return Closed
+		return nil
 	default:
-		return Connected
+		// close all the sockets
+		for _, s := range t.sockets {
+			s.Close()
+		}
+		// close the connection
+		close(t.closed)
+		t.connected = false
+
+		// send a close message
+		// we don't close the link
+		// just the tunnel
+		return t.close()
 	}
+
+	return nil
 }
 
-func (t *tun) String() string {
-	return "micro"
+// Connect the tunnel
+func (t *tun) Connect() error {
+	t.Lock()
+	defer t.Unlock()
+
+	// already connected
+	if t.connected {
+		return nil
+	}
+
+	// send the connect message
+	if err := t.connect(); err != nil {
+		return err
+	}
+
+	// set as connected
+	t.connected = true
+	// create new close channel
+	t.closed = make(chan bool)
+
+	return nil
+}
+
+// Dial an address
+func (t *tun) Dial(addr string) (Conn, error) {
+	c, ok := t.newSocket(addr, t.newSession())
+	if !ok {
+		return nil, errors.New("error dialing " + addr)
+	}
+	// set remote
+	c.remote = addr
+	// set local
+	c.local = "local"
+
+	return c, nil
+}
+
+// Accept a connection on the address
+func (t *tun) Listen(addr string) (Listener, error) {
+	// create a new socket by hashing the address
+	c, ok := t.newSocket(addr, "listener")
+	if !ok {
+		return nil, errors.New("already listening on " + addr)
+	}
+
+	// set remote. it will be replaced by the first message received
+	c.remote = "remote"
+	// set local
+	c.local = addr
+
+	tl := &tunListener{
+		addr: addr,
+		// the accept channel
+		accept: make(chan *socket, 128),
+		// the channel to close
+		closed: make(chan bool),
+		// the connection
+		conn: c,
+		// the listener socket
+		socket: c,
+	}
+
+	// this kicks off the internal message processor
+	// for the listener so it can create pseudo sockets
+	// per session if they do not exist or pass messages
+	// to the existign sessions
+	go tl.process()
+
+	// return the listener
+	return tl, nil
 }

tunnel/listener.go

@@ -0,0 +1,101 @@
+package tunnel
+
+import (
+	"io"
+)
+
+type tunListener struct {
+	// address of the listener
+	addr string
+	// the accept channel
+	accept chan *socket
+	// the channel to close
+	closed chan bool
+	// the connection
+	conn Conn
+	// the listener socket
+	socket *socket
+}
+
+func (t *tunListener) process() {
+	// our connection map for session
+	conns := make(map[string]*socket)
+
+	for {
+		select {
+		case <-t.closed:
+			return
+		// receive a new message
+		case m := <-t.socket.recv:
+			// get a socket
+			sock, ok := conns[m.session]
+			if !ok {
+				// create a new socket session
+				sock = &socket{
+					// our tunnel id
+					id: m.id,
+					// the session id
+					session: m.session,
+					// close chan
+					closed: make(chan bool),
+					// recv called by the acceptor
+					recv: make(chan *message, 128),
+					// use the internal send buffer
+					send: t.socket.send,
+					// wait
+					wait: make(chan bool),
+				}
+
+				// first message
+				sock.recv <- m
+
+				// save the socket
+				conns[m.session] = sock
+
+				// send to accept chan
+				select {
+				case <-t.closed:
+					return
+				case t.accept <- sock:
+				}
+			}
+
+			// send this to the accept chan
+			select {
+			case <-sock.closed:
+				delete(conns, m.session)
+			case sock.recv <- m:
+			}
+		}
+	}
+}
+
+func (t *tunListener) Addr() string {
+	return t.addr
+}
+
+func (t *tunListener) Close() error {
+	select {
+	case <-t.closed:
+		return nil
+	default:
+		close(t.closed)
+	}
+	return nil
+}
+
+// Everytime accept is called we essentially block till we get a new connection
+func (t *tunListener) Accept() (Conn, error) {
+	select {
+	// if the socket is closed return
+	case <-t.closed:
+		return nil, io.EOF
+	// wait for a new connection
+	case c, ok := <-t.accept:
+		if !ok {
+			return nil, io.EOF
+		}
+		return c, nil
+	}
+	return nil, nil
+}

tunnel/options.go

@@ -3,6 +3,7 @@ package tunnel
 import (
 	"github.com/google/uuid"
 	"github.com/micro/go-micro/transport"
+	"github.com/micro/go-micro/transport/quic"
 )
 
 var (
@@ -39,7 +40,7 @@ func Address(a string) Option {
 }
 
 // Nodes specify remote network nodes
-func Nodes(n []string) Option {
+func Nodes(n ...string) Option {
 	return func(o *Options) {
 		o.Nodes = n
 	}
@@ -57,7 +58,6 @@ func DefaultOptions() Options {
 	return Options{
 		Id:        uuid.New().String(),
 		Address:   DefaultAddress,
-		Nodes:     make([]string, 0),
-		Transport: transport.DefaultTransport,
+		Transport: quic.NewTransport(),
 	}
 }

tunnel/socket.go

@@ -1,25 +1,90 @@
 package tunnel
 
-import "github.com/micro/go-micro/transport"
+import (
+	"errors"
 
-type tunSocket struct{}
+	"github.com/micro/go-micro/transport"
+)
 
-func (s *tunSocket) Recv(m *transport.Message) error {
+// socket is our pseudo socket for transport.Socket
+type socket struct {
+	// socket id based on Micro-Tunnel
+	id string
+	// the session id based on Micro.Tunnel-Session
+	session string
+	// closed
+	closed chan bool
+	// remote addr
+	remote string
+	// local addr
+	local string
+	// send chan
+	send chan *message
+	// recv chan
+	recv chan *message
+	// wait until we have a connection
+	wait chan bool
+}
+
+// message is sent over the send channel
+type message struct {
+	// tunnel id
+	id string
+	// the session id
+	session string
+	// transport data
+	data *transport.Message
+}
+
+func (s *socket) Remote() string {
+	return s.remote
+}
+
+func (s *socket) Local() string {
+	return s.local
+}
+
+func (s *socket) Id() string {
+	return s.id
+}
+
+func (s *socket) Session() string {
+	return s.session
+}
+
+func (s *socket) Send(m *transport.Message) error {
+	select {
+	case <-s.closed:
+		return errors.New("socket is closed")
+	default:
+		// no op
+	}
+	// append to backlog
+	s.send <- &message{id: s.id, session: s.session, data: m}
 	return nil
 }
 
-func (s *tunSocket) Send(m *transport.Message) error {
+func (s *socket) Recv(m *transport.Message) error {
+	select {
+	case <-s.closed:
+		return errors.New("socket is closed")
+	default:
+		// no op
+	}
+	// recv from backlog
+	msg := <-s.recv
+	// set message
+	*m = *msg.data
+	// return nil
 	return nil
 }
 
-func (s *tunSocket) Close() error {
+func (s *socket) Close() error {
+	select {
+	case <-s.closed:
+		// no op
+	default:
+		close(s.closed)
+	}
 	return nil
 }
-
-func (s *tunSocket) Local() string {
-	return ""
-}
-
-func (s *tunSocket) Remote() string {
-	return ""
-}

tunnel/transport.go

@@ -1,51 +0,0 @@
-package tunnel
-
-import "github.com/micro/go-micro/transport"
-
-type tunTransport struct {
-	options transport.Options
-}
-
-type tunClient struct {
-	*tunSocket
-	options transport.DialOptions
-}
-
-type tunListener struct {
-	conn chan *tunSocket
-}
-
-func newTransport(opts ...transport.Option) transport.Transport {
-	var options transport.Options
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return &tunTransport{
-		options: options,
-	}
-}
-
-func (t *tunTransport) Init(opts ...transport.Option) error {
-	for _, o := range opts {
-		o(&t.options)
-	}
-	return nil
-}
-
-func (t *tunTransport) Options() transport.Options {
-	return t.options
-}
-
-func (t *tunTransport) Dial(addr string, opts ...transport.DialOption) (transport.Client, error) {
-	return nil, nil
-}
-
-func (t *tunTransport) Listen(addr string, opts ...transport.ListenOption) (transport.Listener, error) {
-	return nil, nil
-}
-
-func (t *tunTransport) String() string {
-	return "micro"
-}

tunnel/tunnel.go

@@ -1,39 +1,43 @@
-// Package tunnel provides micro network tunnelling
+// Package tunnel provides gre network tunnelling
 package tunnel
 
 import (
 	"github.com/micro/go-micro/transport"
 )
 
-// Status is tunnel status
-type Status int
-
-const (
-	// Connected means the tunnel is alive
-	Connected Status = iota
-	// Closed meands the tunnel has been disconnected
-	Closed
-)
-
-// Tunnel creates a p2p network tunnel.
+// Tunnel creates a gre network tunnel on top of a link.
+// It establishes multiple streams using the Micro-Tunnel-Id header
+// and Micro-Tunnel-Session header. The tunnel id is a hash of
+// the address being requested.
 type Tunnel interface {
-	// Id returns tunnel id
-	Id() string
-	// Options returns the tunnel options
-	Options() Options
-	// Address returns tunnel address
-	Address() string
-	// Transport to use by tunne clients
-	Transport() transport.Transport
 	// Connect connects the tunnel
 	Connect() error
 	// Close closes the tunnel
 	Close() error
-	// Status returns tunnel status
-	Status() Status
+	// Dial an endpoint
+	Dial(addr string) (Conn, error)
+	// Accept connections
+	Listen(addr string) (Listener, error)
 }
 
-// NewTunnel creates a new tunnel on top of a link
+// The listener provides similar constructs to the transport.Listener
+type Listener interface {
+	Addr() string
+	Close() error
+	Accept() (Conn, error)
+}
+
+// Conn is a connection dialed or accepted which includes the tunnel id and session
+type Conn interface {
+	// Specifies the tunnel id
+	Id() string
+	// The session
+	Session() string
+	// a transport socket
+	transport.Socket
+}
+
+// NewTunnel creates a new tunnel
 func NewTunnel(opts ...Option) Tunnel {
 	return newTunnel(opts...)
 }

tunnel/tunnel_test.go

@@ -0,0 +1,73 @@
+package tunnel
+
+import (
+	"testing"
+
+	"github.com/micro/go-micro/transport"
+)
+
+// testAccept will accept connections on the transport, create a new link and tunnel on top
+func testAccept(t *testing.T, tun Tunnel, wait chan bool) {
+	// listen on some virtual address
+	tl, err := tun.Listen("test-tunnel")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// accept a connection
+	c, err := tl.Accept()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// get a message
+	for {
+		m := new(transport.Message)
+		if err := c.Recv(m); err != nil {
+			t.Fatal(err)
+		}
+		close(wait)
+		return
+	}
+}
+
+// testSend will create a new link to an address and then a tunnel on top
+func testSend(t *testing.T, tun Tunnel) {
+	// dial a new session
+	c, err := tun.Dial("test-tunnel")
+	if err != nil {
+		t.Fatal(err)
+	}
+	//defer c.Close()
+
+	m := transport.Message{
+		Header: map[string]string{
+			"test": "header",
+		},
+	}
+
+	if err := c.Send(&m); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestTunnel(t *testing.T) {
+	// create a new listener
+	tun := NewTunnel(Nodes(":9096"))
+	err := tun.Connect()
+	if err != nil {
+		t.Fatal(err)
+	}
+	//defer tun.Close()
+
+	wait := make(chan bool)
+
+	// start accepting connections
+	go testAccept(t, tun, wait)
+
+	// send a message
+	testSend(t, tun)
+
+	// wait until message is received
+	<-wait
+}