made (loosely) testable against server

mplexer/packer/conn.go

@@ -1,22 +1,23 @@
 package packer
 
 import (
-	"errors"
 	"net"
 	"time"
 )
 
+// Conn TODO rename to Pipe, perhaps?
 type Conn struct {
 	relaySourceAddr Addr
 	relayRemoteAddr Addr
 	relay           net.Conn
 	local           net.Conn
-	updated         time.Time
+	//updated         time.Time
 }
 
 // TODO conn.go -> conn/conn.go
 // TODO NewConn -> New
 
+// NewConn TODO rename to NewPipe, perhaps?
 func NewConn() *Conn {
 	return nil
 }
@@ -41,11 +42,13 @@ func (c *Conn) Close() error {
 	return c.relay.Close()
 }
 
+/*
 // Error signals an error back to the relay
 func (c *Conn) Error(err error) error {
 	panic(errors.New("not implemented"))
 	return nil
 }
+*/
 
 /*
 // LocalAddr returns the local network address.
@@ -62,7 +65,7 @@ func (c *Conn) LocalAddr() *Addr {
 }
 
 // RemoteAddr returns the remote network address.
-func (c *Conn) RemoteAddr() net.Addr {
+func (c *Conn) RemoteAddr() *Addr {
 	// TODO is this the right one?
 	return &c.relayRemoteAddr
 }

mplexer/packer/decoder.go

@@ -1,42 +1,36 @@
 package packer
 
 import (
-	"context"
-	"errors"
 	"io"
 )
 
-// Decoder handles a ReadCloser stream containing mplexy-encoded clients
+// Decoder handles a Reader stream containing mplexy-encoded clients
 type Decoder struct {
-	ctx context.Context
+	in         io.Reader
-	r   io.ReadCloser
+	bufferSize int
 }
 
 // NewDecoder returns an initialized Decoder
-func NewDecoder(ctx context.Context, r io.ReadCloser) *Decoder {
+func NewDecoder(rin io.Reader) *Decoder {
 	return &Decoder{
-		ctx: ctx,
+		in:         rin,
-		r:   r,
+		bufferSize: defaultBufferSize,
 	}
 }
 
-// StreamDecode will call WriteMessage as often as addressable data exists,
+// Decode will call WriteMessage as often as addressable data exists,
 // reading up to bufferSize (default 8192) at a time
 // (header + data, though headers are often sent separately from data).
-func (d *Decoder) StreamDecode(handler Handler, bufferSize int) error {
+func (d *Decoder) Decode(out Router) error {
-	p := NewParser(handler)
+	p := NewParser(out)
 	rx := make(chan []byte)
 	rxErr := make(chan error)
 
-	if 0 == bufferSize {
-		bufferSize = 8192
-	}
-
 	go func() {
 		for {
-			b := make([]byte, bufferSize)
+			b := make([]byte, d.bufferSize)
 			//fmt.Println("loopers gonna loop")
-			n, err := d.r.Read(b)
+			n, err := d.in.Read(b)
 			if n > 0 {
 				rx <- b[:n]
 			}
@@ -52,20 +46,16 @@ func (d *Decoder) StreamDecode(handler Handler, bufferSize int) error {
 		select {
 		// TODO, do we actually need ctx here?
 		// would it be sufficient to expect the reader to be closed by the caller instead?
-		case <-d.ctx.Done():
-			// TODO: verify that closing the reader will cause the goroutine to be released
-			d.r.Close()
-			return errors.New("cancelled by context")
 		case b := <-rx:
 			_, err := p.Write(b)
 			if nil != err {
 				// an error to write represents an unrecoverable error,
 				// not just a downstream client error
-				d.r.Close()
+				//d.in.Close()
 				return err
 			}
 		case err := <-rxErr:
-			d.r.Close()
+			//d.in.Close()
 			if io.EOF == err {
 				// it can be assumed that err will close though, right
 				return nil

mplexer/packer/listener_test.go

@@ -8,142 +8,203 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
+	jwt "github.com/dgrijalva/jwt-go"
+
 	"github.com/gorilla/websocket"
 )
 
 func TestDialServer(t *testing.T) {
-
 	// TODO replace the websocket connection with a mock server
 
-	relay := os.Getenv("RELAY")
+	relay := "wss://roottest.duckdns.org:8443"
-	authz := os.Getenv("SECRET")
+	authz, err := getToken("xxxxyyyyssss8347")
+	if nil != err {
+		panic(err)
+	}
 
 	ctx := context.Background()
 	wsd := websocket.Dialer{}
 	headers := http.Header{}
 	headers.Set("Authorization", fmt.Sprintf("Bearer %s", authz))
 	// *http.Response
-	wsconn, _, err := wsd.DialContext(ctx, relay, headers)
+	sep := "?"
+	if strings.Contains(relay, sep) {
+		sep = "&"
+	}
+	wsconn, _, err := wsd.DialContext(ctx, relay+sep+"access_token="+authz, headers)
 	if nil != err {
+		fmt.Println("relay:", relay)
 		t.Fatal(err)
 		return
 	}
 
-	mux := &MyMux{}
+	/*
-	err = ListenAndServe(wsconn, mux)
+		t := telebit.New(token)
-	t.Fatal(err)
+		mux := telebit.RouteMux{}
+		mux.HandleTLS("*", mux) // go back to itself
+		mux.HandleProxy("example.com", "localhost:3000")
+		mux.HandleTCP("example.com", func (c *telebit.Conn) {
+			return httpmux.Serve()
+		})
+
+		l := t.Listen("wss://example.com")
+		conn := l.Accept()
+		telebit.Serve(listener, mux)
+		t.ListenAndServe("wss://example.com", mux)
+	*/
+
+	mux := NewRouteMux()
+	// TODO set failure
+	t.Fatal(ListenAndServe(wsconn, mux))
+}
+
+func getToken(secret string) (token string, err error) {
+	domains := []string{"dandel.duckdns.org"}
+	tokenData := jwt.MapClaims{"domains": domains}
+
+	jwtToken := jwt.NewWithClaims(jwt.SigningMethodHS256, tokenData)
+	if token, err = jwtToken.SignedString([]byte(secret)); err != nil {
+		return "", err
+	}
+	return token, nil
 }
 
 type Listener struct {
-	ws       *websocket.Conn
+	ws           *websocket.Conn
-	incoming chan *Conn
+	incoming     chan *Conn
-	close    chan struct{}
+	close        chan struct{}
+	encoder      *Encoder
+	conns        map[string]*Conn
+	chunksParsed int
+	bytesRead    int
 }
 
-func ListenAndServe(ws *websocket.Conn, mux Mux) error {
+func ListenAndServe(ws *websocket.Conn, mux Handler) error {
 	listener := Listen(ws)
 	return Serve(listener, mux)
 }
 
 func Listen(ws *websocket.Conn) *Listener {
+	ctx := context.TODO()
+
+	// Wrap the websocket and feed it into the Encoder and Decoder
+	rw := &WSConn{c: ws, nr: nil}
 	listener := &Listener{
 		ws:       ws,
-		incoming: make(chan *Conn, 1),
+		conns:    map[string]*Conn{},
+		incoming: make(chan *Conn, 1), // buffer ever so slightly
 		close:    make(chan struct{}),
+		encoder:  NewEncoder(ctx, rw),
 	}
+	// TODO perhaps the wrapper should have a mutex
+	// rather than having a goroutine in the encoder
+	go func() {
+		err := listener.encoder.Run()
+		fmt.Printf("encoder stopped entirely: %q", err)
+		rw.c.Close()
+	}()
 
-	ctx := context.TODO()
+	// Decode the stream as it comes in
-	r := &WSConn{
+	decoder := NewDecoder(rw)
-		c: ws,
-		r: nil,
-		w: nil,
-	}
-	decoder := NewDecoder(ctx, r)
-
-	// Feed websocket into Decoder
-	th := &testHandler2{
-		conns:  map[string]*Conn{},
-		connCh: listener.incoming,
-	}
 	go func() {
 		// TODO pass error to Accept()
-		err := decoder.StreamDecode(th, 0)
+		err := decoder.Decode(listener)
-		fmt.Printf("the main stream is done: %q", err)
+		rw.Close()
+		fmt.Printf("the main stream is done: %q\n", err)
 	}()
 
 	return listener
 }
 
-type testHandler2 struct {
+func (l *Listener) RouteBytes(a Addr, b []byte) {
-	conns        map[string]*Conn
+	// TODO use context to be able to cancel many at once?
-	connCh       chan *Conn
+	l.chunksParsed++
-	chunksParsed int
-	bytesRead    int
-}
 
-func (th *testHandler2) WriteMessage(a Addr, b []byte) {
-	th.chunksParsed++
 	addr := &a
-	_, ok := th.conns[addr.Network()]
+	pipe := l.getPipe(addr)
-	if !ok {
+
-		rconn, wconn := net.Pipe()
+	// handle errors before data writes because I don't
-		conn := &Conn{
+	// remember where the error message goes
-			updated:         time.Now(),
+	if "error" == string(addr.scheme) {
-			relayRemoteAddr: *addr,
+		pipe.Close()
-			relay:           rconn,
+		delete(l.conns, addr.Network())
-			local:           wconn,
+		fmt.Printf("a stream errored remotely: %v\n", addr)
-		}
+	}
-		th.conns[addr.Network()] = conn
+
-		th.connCh <- conn
+	// write data, if any
+	if len(b) > 0 {
+		l.bytesRead += len(b)
+		pipe.Write(b)
+	}
+	// EOF, if needed
+	if "end" == string(addr.scheme) {
+		pipe.Close()
+		delete(l.conns, addr.Network())
 	}
-	th.bytesRead += len(b)
 }
 
-func Serve(listener *Listener, mux Mux) error {
+func (l *Listener) getPipe(addr *Addr) *Conn {
-	w := &WSConn{
+	connID := addr.Network()
-		c: listener.ws,
+	pipe, ok := l.conns[connID]
-		r: nil,
-		w: nil,
-	}
-	ctx := context.TODO()
-	encoder := NewEncoder(ctx, w)
-	encoder.Start()
 
+	// Pipe exists
+	if ok {
+		return pipe
+	}
+
+	// Create pipe
+	rawPipe, encodable := net.Pipe()
+	pipe = &Conn{
+		//updated:         time.Now(),
+		relayRemoteAddr: *addr,
+		relay:           rawPipe,
+	}
+	l.conns[connID] = pipe
+	l.incoming <- pipe
+
+	// Handle encoding
+	go func() {
+		// TODO handle err
+		err := l.encoder.Encode(encodable, *pipe.LocalAddr())
+		// the error may be EOF or ErrServerClosed or ErrGoingAwawy or some such
+		// or it might be an actual error
+		// In any case, we'll just close it all
+		encodable.Close()
+		pipe.Close()
+		fmt.Printf("a stream is done: %q\n", err)
+	}()
+
+	return pipe
+}
+
+func Serve(listener *Listener, mux Handler) error {
 	for {
 		client, err := listener.Accept()
 		if nil != err {
 			return err
 		}
-		lconn, err := mux.LookupTarget(client.LocalAddr())
-		if nil != err {
-			conn.Close()
-			continue
-		}
 
 		go func() {
-			// TODO handle err
+			err = mux.Serve(client)
-			err := encoder.StreamEncode(*conn.LocalAddr(), lconn, 0)
+			if nil != err {
-			fmt.Printf("a stream is done: %q", err)
+				if io.EOF != err {
+					fmt.Printf("client could not be served: %q\n", err.Error())
+				}
+			}
+			client.Close()
 		}()
 	}
 }
 
-func Blah() {
-		go func() {
-			pipe
-		}
-
-
-}
-
 func (l *Listener) Accept() (*Conn, error) {
 	select {
-	case conn, ok := <-l.incoming:
+	case rconn, ok := <-l.incoming:
 		if ok {
-			return conn, nil
+			return rconn, nil
 		}
 		return nil, io.EOF
 
@@ -154,17 +215,127 @@ func (l *Listener) Accept() (*Conn, error) {
 	}
 }
 
-type Mux interface {
+type Handler interface {
-	LookupTarget(*Addr) (net.Conn, error)
+	Serve(*Conn) error
+	GetTargetConn(*Addr) (net.Conn, error)
 }
 
-type MyMux struct {
+type RouteMux struct {
+	defaultTimeout time.Duration
+}
+
+func NewRouteMux() *RouteMux {
+	mux := &RouteMux{
+		defaultTimeout: 45 * time.Second,
+	}
+	return mux
+}
+
+func (m *RouteMux) Serve(client *Conn) error {
+	// TODO could proxy or handle directly, etc
+	target, err := m.GetTargetConn(client.RemoteAddr())
+	if nil != err {
+		return err
+	}
+
+	return Forward(client, target, m.defaultTimeout)
+}
+
+// Forward port-forwards a relay (websocket) client to a target (local) server
+func Forward(client *Conn, target net.Conn, timeout time.Duration) error {
+
+	// Something like ReadAhead(size) should signal
+	// to read and send up to `size` bytes without waiting
+	// for a response - since we can't signal 'non-read' as
+	// is the normal operation of tcp... or can we?
+	// And how do we distinguish idle from dropped?
+	// Maybe this should have been a udp protocol???
+
+	defer client.Close()
+	defer target.Close()
+
+	srcCh := make(chan []byte)
+	dstCh := make(chan []byte)
+	srcErrCh := make(chan error)
+	dstErrCh := make(chan error)
+
+	// Source (Relay) Read Channel
+	go func() {
+		for {
+			b := make([]byte, defaultBufferSize)
+			n, err := client.Read(b)
+			if n > 0 {
+				srcCh <- b
+			}
+			if nil != err {
+				// TODO let client log this server-side error (unless EOF)
+				// (nil here because we probably can't send the error to the relay)
+				srcErrCh <- err
+				break
+			}
+		}
+	}()
+
+	// Target (Local) Read Channel
+	go func() {
+		for {
+			b := make([]byte, defaultBufferSize)
+			n, err := target.Read(b)
+			if n > 0 {
+				dstCh <- b
+			}
+			if nil != err {
+				if io.EOF == err {
+					err = nil
+				}
+				dstErrCh <- err
+				break
+			}
+		}
+	}()
+
+	var err error = nil
+	for {
+		select {
+		// TODO do we need a context here?
+		//case <-ctx.Done():
+		//		break
+		case b := <-srcCh:
+			client.SetDeadline(time.Now().Add(timeout))
+			_, err = target.Write(b)
+			if nil != err {
+				fmt.Printf("write to target failed: %q", err.Error())
+				break
+			}
+		case b := <-dstCh:
+			target.SetDeadline(time.Now().Add(timeout))
+			_, err = client.Write(b)
+			if nil != err {
+				fmt.Printf("write to remote failed: %q", err.Error())
+				break
+			}
+		case err = <-srcErrCh:
+			if nil != err {
+				fmt.Printf("read from remote failed: %q", err.Error())
+			}
+			break
+		case err = <-dstErrCh:
+			if nil != err {
+				fmt.Printf("read from target failed: %q", err.Error())
+			}
+			break
+
+		}
+	}
+
+	client.Close()
+	return err
 }
 
 // this function is very client-specific logic
-func (m *MyMux) LookupTarget(paddr *Addr) (net.Conn, error) {
+func (m *RouteMux) GetTargetConn(paddr *Addr) (net.Conn, error) {
-	//if target := LookupPort(paddr.Port()); nil != target { }
+	//if target := GetTargetByPort(paddr.Port()); nil != target { }
-	if target := m.LookupServername(paddr.Hostname()); nil != target {
+	if target := m.GetTargetByServername(paddr.Hostname()); nil != target {
 		tconn, err := net.Dial(target.Network(), target.Hostname())
 		if nil != err {
 			return nil, err
@@ -185,7 +356,7 @@ func (m *MyMux) LookupTarget(paddr *Addr) (net.Conn, error) {
 	return nil, errors.New("Bad Gateway")
 }
 
-func (m *MyMux) LookupServername(servername string) *Addr {
+func (m *RouteMux) GetTargetByServername(servername string) *Addr {
 	return NewAddr(
 		HTTPS,
 		TCP, // TCP -> termination.None? / Plain?
@@ -195,21 +366,21 @@ func (m *MyMux) LookupServername(servername string) *Addr {
 }
 
 type WSConn struct {
-	c      *websocket.Conn
+	c  *websocket.Conn
-	r      io.Reader
+	nr io.Reader
-	w      io.WriteCloser
+	//w      io.WriteCloser
-	pingCh chan struct{}
+	//pingCh chan struct{}
 }
 
 func (ws *WSConn) Read(b []byte) (int, error) {
-	if nil == ws.r {
+	if nil == ws.nr {
 		_, r, err := ws.c.NextReader()
 		if nil != err {
 			return 0, err
 		}
-		ws.r = r
+		ws.nr = r
 	}
-	n, err := ws.r.Read(b)
+	n, err := ws.nr.Read(b)
 	if io.EOF == err {
 		err = nil
 	}
@@ -218,17 +389,17 @@ func (ws *WSConn) Read(b []byte) (int, error) {
 
 func (ws *WSConn) Write(b []byte) (int, error) {
 	// TODO create or reset ping deadline
+	// TODO document that more complete writes are preferred?
 
 	w, err := ws.c.NextWriter(websocket.BinaryMessage)
 	if nil != err {
 		return 0, err
 	}
-	ws.w = w
+	n, err := w.Write(b)
-	n, err := ws.w.Write(b)
 	if nil != err {
 		return n, err
 	}
-	err = ws.w.Close()
+	err = w.Close()
 	return n, err
 }
 

mplexer/packer/parser.go

@@ -5,7 +5,7 @@ import (
 )
 
 type Parser struct {
-	handler    Handler
+	handler    Router
 	newConns   chan *Conn
 	conns      map[string]*Conn
 	state      ParserState
@@ -36,7 +36,7 @@ const (
 	VersionState State = 0
 )
 
-func NewParser(handler Handler) *Parser {
+func NewParser(handler Router) *Parser {
 	return &Parser{
 		conns:     make(map[string]*Conn),
 		newConns:  make(chan *Conn, 2), // Buffered to make testing easier
@@ -46,8 +46,8 @@ func NewParser(handler Handler) *Parser {
 	}
 }
 
-type Handler interface {
+type Router interface {
-	WriteMessage(Addr, []byte)
+	RouteBytes(Addr, []byte)
 }
 
 // Write receives tunnel data and creates or writes to connections

mplexer/packer/telebit.go

@@ -0,0 +1,12 @@
+package packer
+
+import "errors"
+
+// Note: 64k is the TCP max, but 1460b is the 100mbit Ethernet max (1500 MTU - overhead),
+// but 1Gbit Ethernet (Jumbo frame) has an 9000b MTU
+// Nerds posting benchmarks on SO show that 8k seems about right,
+// but even 1024b could work well.
+var defaultBufferSize = 8192
+
+// ErrBadGateway means that the target did not accept the connection
+var ErrBadGateway = errors.New("EBADGATEWAY")

mplexer/packer/v1.go

@@ -8,19 +8,28 @@ import (
 )
 
 const (
+	// HeaderLengthState is the 2nd (1) state
 	HeaderLengthState State = 1 + iota
+	// HeaderState is the 3rd (2) state
 	HeaderState
+	// PayloadState is the 4th (3) state
 	PayloadState
 )
 
 const (
+	// FamilyIndex is the 1st (0) address element, either IPv4 or IPv6
 	FamilyIndex int = iota
+	// AddressIndex is the 2nd (1) address element, the IP or Hostname
 	AddressIndex
+	// PortIndex is the 3rd (2) address element, the Port
 	PortIndex
+	// LengthIndex is the 4th (3) address element, the Payload size
 	LengthIndex
+	// ServiceIndex is the 5th (4) address element, the Scheme or Control message type
 	ServiceIndex
 )
 
+// Header is the MPLEXY address/control meta data that comes before a packet
 type Header struct {
 	Family  string
 	Address string
@@ -178,7 +187,7 @@ func (p *Parser) unpackV1Payload(b []byte, n int) ([]byte, error) {
 		*/
 
 		//fmt.Printf("[debug] [2] payload written: %d | payload length: %d\n", p.state.payloadWritten, p.state.payloadLen)
-		p.handler.WriteMessage(p.state.addr, []byte{})
+		p.handler.RouteBytes(p.state.addr, []byte{})
 		return b, nil
 	}
 
@@ -198,7 +207,7 @@ func (p *Parser) unpackV1Payload(b []byte, n int) ([]byte, error) {
 			return b, nil
 		}
 	*/
-	p.handler.WriteMessage(p.state.addr, c)
+	p.handler.RouteBytes(p.state.addr, c)
 	p.consumed += k
 	p.state.payloadWritten += k