Feature: add vmess WebSocket early data (#1505)

Co-authored-by: ShinyGwyn <79344143+ShinyGwyn@users.noreply.github.com>

adapter/outbound/vmess.go

@@ -43,6 +43,7 @@ type VmessOption struct {
 	HTTPOpts       HTTPOptions       `proxy:"http-opts,omitempty"`
 	HTTP2Opts      HTTP2Options      `proxy:"h2-opts,omitempty"`
 	GrpcOpts       GrpcOptions       `proxy:"grpc-opts,omitempty"`
+	WSOpts         WSOptions         `proxy:"ws-opts,omitempty"`
 	WSPath         string            `proxy:"ws-path,omitempty"`
 	WSHeaders      map[string]string `proxy:"ws-headers,omitempty"`
 	SkipCertVerify bool              `proxy:"skip-cert-verify,omitempty"`
@@ -64,19 +65,35 @@ type GrpcOptions struct {
 	GrpcServiceName string `proxy:"grpc-service-name,omitempty"`
 }
 
+type WSOptions struct {
+	Path                string            `proxy:"path,omitempty"`
+	Headers             map[string]string `proxy:"headers,omitempty"`
+	MaxEarlyData        int               `proxy:"max-early-data,omitempty"`
+	EarlyDataHeaderName string            `proxy:"early-data-header-name,omitempty"`
+}
+
 // StreamConn implements C.ProxyAdapter
 func (v *Vmess) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error) {
 	var err error
 	switch v.option.Network {
 	case "ws":
+		if v.option.WSOpts.Path == "" {
+			v.option.WSOpts.Path = v.option.WSPath
+		}
+		if len(v.option.WSOpts.Headers) == 0 {
+			v.option.WSOpts.Headers = v.option.WSHeaders
+		}
+
 		host, port, _ := net.SplitHostPort(v.addr)
 		wsOpts := &vmess.WebsocketConfig{
 			Host:                host,
 			Port:                port,
-			Path: v.option.WSPath,
+			Path:                v.option.WSOpts.Path,
+			MaxEarlyData:        v.option.WSOpts.MaxEarlyData,
+			EarlyDataHeaderName: v.option.WSOpts.EarlyDataHeaderName,
 		}
 
-		if len(v.option.WSHeaders) != 0 {
+		if len(v.option.WSOpts.Headers) != 0 {
 			header := http.Header{}
 			for key, value := range v.option.WSHeaders {
 				header.Add(key, value)

transport/vmess/conn.go

@@ -59,12 +59,12 @@ func (vc *Conn) Read(b []byte) (int, error) {
 func (vc *Conn) sendRequest() error {
 	timestamp := time.Now()
 
+	mbuf := &bytes.Buffer{}
+
 	if !vc.isAead {
 		h := hmac.New(md5.New, vc.id.UUID.Bytes())
 		binary.Write(h, binary.BigEndian, uint64(timestamp.Unix()))
-		if _, err := vc.Conn.Write(h.Sum(nil)); err != nil {
-			return err
-		}
+		mbuf.Write(h.Sum(nil))
 	}
 
 	buf := &bytes.Buffer{}
@@ -110,7 +110,8 @@ func (vc *Conn) sendRequest() error {
 
 		stream := cipher.NewCFBEncrypter(block, hashTimestamp(timestamp))
 		stream.XORKeyStream(buf.Bytes(), buf.Bytes())
-		_, err = vc.Conn.Write(buf.Bytes())
+		mbuf.Write(buf.Bytes())
+		_, err = vc.Conn.Write(mbuf.Bytes())
 		return err
 	}
 

transport/vmess/websocket.go

@@ -1,7 +1,11 @@
 package vmess
 
 import (
+	"bytes"
+	"context"
 	"crypto/tls"
+	"encoding/base64"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -23,6 +27,15 @@ type websocketConn struct {
 	rMux sync.Mutex
 	wMux sync.Mutex
 }
+type websocketWithEarlyDataConn struct {
+	net.Conn
+	underlay net.Conn
+	closed   bool
+	dialed   chan bool
+	cancel   context.CancelFunc
+	ctx      context.Context
+	config   *WebsocketConfig
+}
 
 type WebsocketConfig struct {
 	Host                string
@@ -32,6 +45,8 @@ type WebsocketConfig struct {
 	TLS                 bool
 	SkipCertVerify      bool
 	ServerName          string
+	MaxEarlyData        int
+	EarlyDataHeaderName string
 }
 
 // Read implements net.Conn.Read()
@@ -113,7 +128,121 @@ func (wsc *websocketConn) SetWriteDeadline(t time.Time) error {
 	return wsc.conn.SetWriteDeadline(t)
 }
 
-func StreamWebsocketConn(conn net.Conn, c *WebsocketConfig) (net.Conn, error) {
+func (wsedc *websocketWithEarlyDataConn) Dial(earlyData []byte) error {
+	earlyDataBuf := bytes.NewBuffer(nil)
+	base64EarlyDataEncoder := base64.NewEncoder(base64.RawURLEncoding, earlyDataBuf)
+
+	earlydata := bytes.NewReader(earlyData)
+	limitedEarlyDatareader := io.LimitReader(earlydata, int64(wsedc.config.MaxEarlyData))
+	n, encerr := io.Copy(base64EarlyDataEncoder, limitedEarlyDatareader)
+	if encerr != nil {
+		return errors.New("failed to encode early data: " + encerr.Error())
+	}
+
+	if errc := base64EarlyDataEncoder.Close(); errc != nil {
+		return errors.New("failed to encode early data tail: " + errc.Error())
+	}
+
+	var err error
+	if wsedc.Conn, err = streamWebsocketConn(wsedc.underlay, wsedc.config, earlyDataBuf); err != nil {
+		wsedc.Close()
+		return errors.New("failed to dial WebSocket: " + err.Error())
+	}
+
+	wsedc.dialed <- true
+
+	if n != int64(len(earlyData)) {
+		_, err = wsedc.Conn.Write(earlyData[n:])
+	}
+
+	return err
+}
+
+func (wsedc *websocketWithEarlyDataConn) Write(b []byte) (int, error) {
+	if wsedc.closed {
+		return 0, io.ErrClosedPipe
+	}
+	if wsedc.Conn == nil {
+		if err := wsedc.Dial(b); err != nil {
+			return 0, err
+		}
+		return len(b), nil
+	}
+
+	return wsedc.Conn.Write(b)
+}
+
+func (wsedc *websocketWithEarlyDataConn) Read(b []byte) (int, error) {
+	if wsedc.closed {
+		return 0, io.ErrClosedPipe
+	}
+	if wsedc.Conn == nil {
+		select {
+		case <-wsedc.ctx.Done():
+			return 0, io.ErrUnexpectedEOF
+		case <-wsedc.dialed:
+		}
+	}
+	return wsedc.Conn.Read(b)
+}
+
+func (wsedc *websocketWithEarlyDataConn) Close() error {
+	wsedc.closed = true
+	wsedc.cancel()
+	if wsedc.Conn == nil {
+		return nil
+	}
+	return wsedc.Conn.Close()
+}
+
+func (wsedc *websocketWithEarlyDataConn) LocalAddr() net.Addr {
+	if wsedc.Conn == nil {
+		return wsedc.underlay.LocalAddr()
+	}
+	return wsedc.Conn.LocalAddr()
+}
+
+func (wsedc *websocketWithEarlyDataConn) RemoteAddr() net.Addr {
+	if wsedc.Conn == nil {
+		return wsedc.underlay.RemoteAddr()
+	}
+	return wsedc.Conn.RemoteAddr()
+}
+
+func (wsedc *websocketWithEarlyDataConn) SetDeadline(t time.Time) error {
+	if err := wsedc.SetReadDeadline(t); err != nil {
+		return err
+	}
+	return wsedc.SetWriteDeadline(t)
+}
+
+func (wsedc *websocketWithEarlyDataConn) SetReadDeadline(t time.Time) error {
+	if wsedc.Conn == nil {
+		return nil
+	}
+	return wsedc.Conn.SetReadDeadline(t)
+}
+
+func (wsedc *websocketWithEarlyDataConn) SetWriteDeadline(t time.Time) error {
+	if wsedc.Conn == nil {
+		return nil
+	}
+	return wsedc.Conn.SetWriteDeadline(t)
+}
+
+func streamWebsocketWithEarlyDataConn(conn net.Conn, c *WebsocketConfig) (net.Conn, error) {
+	ctx, cancel := context.WithCancel(context.Background())
+	conn = &websocketWithEarlyDataConn{
+		dialed:   make(chan bool, 1),
+		cancel:   cancel,
+		ctx:      ctx,
+		underlay: conn,
+		config:   c,
+	}
+	return conn, nil
+}
+
+func streamWebsocketConn(conn net.Conn, c *WebsocketConfig, earlyData *bytes.Buffer) (net.Conn, error) {
 	dialer := &websocket.Dialer{
 		NetDial: func(network, addr string) (net.Conn, error) {
 			return conn, nil
@@ -152,6 +281,14 @@ func StreamWebsocketConn(conn net.Conn, c *WebsocketConfig) (net.Conn, error) {
 		}
 	}
 
+	if earlyData != nil {
+		if c.EarlyDataHeaderName == "" {
+			uri.Path += earlyData.String()
+		} else {
+			headers.Set(c.EarlyDataHeaderName, earlyData.String())
+		}
+	}
+
 	wsConn, resp, err := dialer.Dial(uri.String(), headers)
 	if err != nil {
 		reason := err.Error()
@@ -166,3 +303,11 @@ func StreamWebsocketConn(conn net.Conn, c *WebsocketConfig) (net.Conn, error) {
 		remoteAddr: conn.RemoteAddr(),
 	}, nil
 }
+
+func StreamWebsocketConn(conn net.Conn, c *WebsocketConfig) (net.Conn, error) {
+	if c.MaxEarlyData > 0 {
+		return streamWebsocketWithEarlyDataConn(conn, c)
+	}
+
+	return streamWebsocketConn(conn, c, nil)
+}