From c8f6ba9ff0fd346543b8c2580247cf00b2e5655b Mon Sep 17 00:00:00 2001
From: mmmray <142015632+mmmray@users.noreply.github.com>
Date: Thu, 11 Jul 2024 09:56:20 +0200
Subject: [PATCH] Add SplitHTTP Browser Dialer support (#3484)

---
 transport/internet/browser_dialer/dialer.go   | 121 ++++++++++
 transport/internet/browser_dialer/dialer.html | 136 ++++++++++++
 .../internet/splithttp/browser_client.go      |  39 ++++
 transport/internet/splithttp/client.go        | 169 ++++++++++++++
 transport/internet/splithttp/dialer.go        | 208 ++++--------------
 transport/internet/splithttp/hub.go           |   4 +-
 transport/internet/splithttp/upload_queue.go  |  12 +-
 transport/internet/websocket/connection.go    |  14 +-
 transport/internet/websocket/dialer.go        |  66 +-----
 transport/internet/websocket/dialer.html      |  59 -----
 transport/internet/websocket/hub.go           |   2 +-
 11 files changed, 536 insertions(+), 294 deletions(-)
 create mode 100644 transport/internet/browser_dialer/dialer.go
 create mode 100644 transport/internet/browser_dialer/dialer.html
 create mode 100644 transport/internet/splithttp/browser_client.go
 create mode 100644 transport/internet/splithttp/client.go
 delete mode 100644 transport/internet/websocket/dialer.html

diff --git a/transport/internet/browser_dialer/dialer.go b/transport/internet/browser_dialer/dialer.go
new file mode 100644
index 00000000..3f85f6a6
--- /dev/null
+++ b/transport/internet/browser_dialer/dialer.go
@@ -0,0 +1,121 @@
+package browser_dialer
+
+import (
+	"bytes"
+	"context"
+	_ "embed"
+	"encoding/base64"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/platform"
+	"github.com/xtls/xray-core/common/uuid"
+)
+
+//go:embed dialer.html
+var webpage []byte
+
+var conns chan *websocket.Conn
+
+var upgrader = &websocket.Upgrader{
+	ReadBufferSize:   0,
+	WriteBufferSize:  0,
+	HandshakeTimeout: time.Second * 4,
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+func init() {
+	addr := platform.NewEnvFlag(platform.BrowserDialerAddress).GetValue(func() string { return "" })
+	if addr != "" {
+		token := uuid.New()
+		csrfToken := token.String()
+		webpage = bytes.ReplaceAll(webpage, []byte("csrfToken"), []byte(csrfToken))
+		conns = make(chan *websocket.Conn, 256)
+		go http.ListenAndServe(addr, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.URL.Path == "/websocket" {
+				if r.URL.Query().Get("token") == csrfToken {
+					if conn, err := upgrader.Upgrade(w, r, nil); err == nil {
+						conns <- conn
+					} else {
+						errors.LogError(context.Background(), "Browser dialer http upgrade unexpected error")
+					}
+				}
+			} else {
+				w.Write(webpage)
+			}
+		}))
+	}
+}
+
+func HasBrowserDialer() bool {
+	return conns != nil
+}
+
+func DialWS(uri string, ed []byte) (*websocket.Conn, error) {
+	data := []byte("WS " + uri)
+	if ed != nil {
+		data = append(data, " "+base64.RawURLEncoding.EncodeToString(ed)...)
+	}
+
+	return dialRaw(data)
+}
+
+func DialGet(uri string) (*websocket.Conn, error) {
+	data := []byte("GET " + uri)
+	return dialRaw(data)
+}
+
+func DialPost(uri string, payload []byte) error {
+	data := []byte("POST " + uri)
+	conn, err := dialRaw(data)
+	if err != nil {
+		return err
+	}
+
+	err = conn.WriteMessage(websocket.BinaryMessage, payload)
+	if err != nil {
+		return err
+	}
+
+	err = CheckOK(conn)
+	if err != nil {
+		return err
+	}
+
+	conn.Close()
+	return nil
+}
+
+func dialRaw(data []byte) (*websocket.Conn, error) {
+	var conn *websocket.Conn
+	for {
+		conn = <-conns
+		if conn.WriteMessage(websocket.TextMessage, data) != nil {
+			conn.Close()
+		} else {
+			break
+		}
+	}
+	err := CheckOK(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func CheckOK(conn *websocket.Conn) error {
+	if _, p, err := conn.ReadMessage(); err != nil {
+		conn.Close()
+		return err
+	} else if s := string(p); s != "ok" {
+		conn.Close()
+		return errors.New(s)
+	}
+
+	return nil
+}
diff --git a/transport/internet/browser_dialer/dialer.html b/transport/internet/browser_dialer/dialer.html
new file mode 100644
index 00000000..3429ca9a
--- /dev/null
+++ b/transport/internet/browser_dialer/dialer.html
@@ -0,0 +1,136 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<title>Browser Dialer</title>
+</head>
+<body>
+	<script>
+		// Copyright (c) 2021 XRAY. Mozilla Public License 2.0.
+		var url = "ws://" + window.location.host + "/websocket?token=csrfToken";
+		var clientIdleCount = 0;
+		var upstreamGetCount = 0;
+		var upstreamWsCount = 0;
+		var upstreamPostCount = 0;
+		setInterval(check, 1000);
+		function check() {
+			if (clientIdleCount > 0) {
+				return;
+			}
+
+			clientIdleCount += 1;
+			console.log("Prepare", url);
+			var ws = new WebSocket(url);
+			// arraybuffer is significantly faster in chrome than default
+			// blob, tested with chrome 123
+			ws.binaryType = "arraybuffer";
+			ws.onmessage = function (event) {
+				clientIdleCount -= 1;
+				let [method, url, protocol] = event.data.split(" ");
+				if (method == "WS") {
+					upstreamWsCount += 1;
+					console.log("Dial WS", url, protocol);
+					const wss = new WebSocket(url, protocol);
+					wss.binaryType = "arraybuffer";
+					var opened = false;
+					ws.onmessage = function (event) {
+						wss.send(event.data)
+					}
+					wss.onopen = function (event) {
+						opened = true;
+						ws.send("ok")
+					}
+					wss.onmessage = function (event) {
+						ws.send(event.data)
+					}
+					wss.onclose = function (event) {
+						upstreamWsCount -= 1;
+						console.log("Dial WS DONE, remaining: ", upstreamWsCount);
+						ws.close()
+					}
+					wss.onerror = function (event) {
+						!opened && ws.send("fail")
+						wss.close()
+					}
+					ws.onclose = function (event) {
+						wss.close()
+					}
+				} else if (method == "GET") {
+					(async () => {
+						console.log("Dial GET", url);
+						ws.send("ok");
+						const controller = new AbortController();
+
+						/*
+						Aborting a streaming response in JavaScript
+						requires two levers to be pulled:
+
+						First, the streaming read itself has to be cancelled using
+						reader.cancel(), only then controller.abort() will actually work.
+
+						If controller.abort() alone is called while a
+						reader.read() is ongoing, it will block until the server closes the
+						response, the page is refreshed or the network connection is lost.
+						*/
+
+						let reader = null;
+						ws.onclose = (event) => {
+							try {
+								reader && reader.cancel();
+							} catch(e) {}
+
+							try {
+								controller.abort();
+							} catch(e) {}
+						}
+
+						try {
+							upstreamGetCount += 1;
+							const response = await fetch(url, {signal: controller.signal});
+
+							const body = await response.body;
+							reader = body.getReader();
+
+							while (true) {
+								const { done, value } = await reader.read();
+								ws.send(value);
+								if (done) break;
+							}
+						} finally {
+							upstreamGetCount -= 1;
+							console.log("Dial GET DONE, remaining: ", upstreamGetCount);
+							ws.close();
+						}
+					})()
+				} else if (method == "POST") {
+					upstreamPostCount += 1;
+					console.log("Dial POST", url);
+					ws.send("ok");
+					ws.onmessage = async (event) => {
+						try {
+							const response = await fetch(
+								url,
+								{method: "POST", body: event.data}
+							);
+							if (response.ok) {
+								ws.send("ok");
+							} else {
+								console.error("bad status code");
+								ws.send("fail");
+							}
+						} finally {
+							upstreamPostCount -= 1;
+							console.log("Dial POST DONE, remaining: ", upstreamPostCount);
+							ws.close();
+						}
+					};
+				}
+
+				check()
+			}
+			ws.onerror = function (event) {
+				ws.close()
+			}
+		}
+	</script>
+</body>
+</html>
diff --git a/transport/internet/splithttp/browser_client.go b/transport/internet/splithttp/browser_client.go
new file mode 100644
index 00000000..8a23682e
--- /dev/null
+++ b/transport/internet/splithttp/browser_client.go
@@ -0,0 +1,39 @@
+package splithttp
+
+import (
+	"context"
+	"io"
+	"io/ioutil"
+	gonet "net"
+
+	"github.com/xtls/xray-core/transport/internet/browser_dialer"
+	"github.com/xtls/xray-core/transport/internet/websocket"
+)
+
+// implements splithttp.DialerClient in terms of browser dialer
+// has no fields because everything is global state :O)
+type BrowserDialerClient struct{}
+
+func (c *BrowserDialerClient) OpenDownload(ctx context.Context, baseURL string) (io.ReadCloser, gonet.Addr, gonet.Addr, error) {
+	conn, err := browser_dialer.DialGet(baseURL)
+	dummyAddr := &gonet.IPAddr{}
+	if err != nil {
+		return nil, dummyAddr, dummyAddr, err
+	}
+
+	return websocket.NewConnection(conn, dummyAddr, nil), conn.RemoteAddr(), conn.LocalAddr(), nil
+}
+
+func (c *BrowserDialerClient) SendUploadRequest(ctx context.Context, url string, payload io.ReadWriteCloser, contentLength int64) error {
+	bytes, err := ioutil.ReadAll(payload)
+	if err != nil {
+		return err
+	}
+
+	err = browser_dialer.DialPost(url, bytes)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/transport/internet/splithttp/client.go b/transport/internet/splithttp/client.go
new file mode 100644
index 00000000..dd48ee6d
--- /dev/null
+++ b/transport/internet/splithttp/client.go
@@ -0,0 +1,169 @@
+package splithttp
+
+import (
+	"bytes"
+	"context"
+	"io"
+	gonet "net"
+	"net/http"
+	"net/http/httptrace"
+	"sync"
+
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/signal/done"
+)
+
+// interface to abstract between use of browser dialer, vs net/http
+type DialerClient interface {
+	// (ctx, baseURL, payload) -> err
+	// baseURL already contains sessionId and seq
+	SendUploadRequest(context.Context, string, io.ReadWriteCloser, int64) error
+
+	// (ctx, baseURL) -> (downloadReader, remoteAddr, localAddr)
+	// baseURL already contains sessionId
+	OpenDownload(context.Context, string) (io.ReadCloser, net.Addr, net.Addr, error)
+}
+
+// implements splithttp.DialerClient in terms of direct network connections
+type DefaultDialerClient struct {
+	transportConfig *Config
+	download        *http.Client
+	upload          *http.Client
+	isH2            bool
+	// pool of net.Conn, created using dialUploadConn
+	uploadRawPool  *sync.Pool
+	dialUploadConn func(ctxInner context.Context) (net.Conn, error)
+}
+
+func (c *DefaultDialerClient) OpenDownload(ctx context.Context, baseURL string) (io.ReadCloser, gonet.Addr, gonet.Addr, error) {
+	var remoteAddr gonet.Addr
+	var localAddr gonet.Addr
+	// this is done when the TCP/UDP connection to the server was established,
+	// and we can unblock the Dial function and print correct net addresses in
+	// logs
+	gotConn := done.New()
+
+	var downResponse io.ReadCloser
+	gotDownResponse := done.New()
+
+	go func() {
+		trace := &httptrace.ClientTrace{
+			GotConn: func(connInfo httptrace.GotConnInfo) {
+				remoteAddr = connInfo.Conn.RemoteAddr()
+				localAddr = connInfo.Conn.LocalAddr()
+				gotConn.Close()
+			},
+		}
+
+		// in case we hit an error, we want to unblock this part
+		defer gotConn.Close()
+
+		req, err := http.NewRequestWithContext(
+			httptrace.WithClientTrace(ctx, trace),
+			"GET",
+			baseURL,
+			nil,
+		)
+		if err != nil {
+			errors.LogInfoInner(ctx, err, "failed to construct download http request")
+			gotDownResponse.Close()
+			return
+		}
+
+		req.Header = c.transportConfig.GetRequestHeader()
+
+		response, err := c.download.Do(req)
+		gotConn.Close()
+		if err != nil {
+			errors.LogInfoInner(ctx, err, "failed to send download http request")
+			gotDownResponse.Close()
+			return
+		}
+
+		if response.StatusCode != 200 {
+			response.Body.Close()
+			errors.LogInfo(ctx, "invalid status code on download:", response.Status)
+			gotDownResponse.Close()
+			return
+		}
+
+		downResponse = response.Body
+		gotDownResponse.Close()
+	}()
+
+	// we want to block Dial until we know the remote address of the server,
+	// for logging purposes
+	<-gotConn.Wait()
+
+	lazyDownload := &LazyReader{
+		CreateReader: func() (io.ReadCloser, error) {
+			<-gotDownResponse.Wait()
+			if downResponse == nil {
+				return nil, errors.New("downResponse failed")
+			}
+			return downResponse, nil
+		},
+	}
+
+	return lazyDownload, remoteAddr, localAddr, nil
+}
+
+func (c *DefaultDialerClient) SendUploadRequest(ctx context.Context, url string, payload io.ReadWriteCloser, contentLength int64) error {
+	req, err := http.NewRequest("POST", url, payload)
+	req.ContentLength = contentLength
+	if err != nil {
+		return err
+	}
+	req.Header = c.transportConfig.GetRequestHeader()
+
+	if c.isH2 {
+		resp, err := c.upload.Do(req)
+		if err != nil {
+			return err
+		}
+
+		defer resp.Body.Close()
+
+		if resp.StatusCode != 200 {
+			return errors.New("bad status code:", resp.Status)
+		}
+	} else {
+		// stringify the entire HTTP/1.1 request so it can be
+		// safely retried. if instead req.Write is called multiple
+		// times, the body is already drained after the first
+		// request
+		requestBytes := new(bytes.Buffer)
+		common.Must(req.Write(requestBytes))
+
+		var uploadConn any
+
+		for {
+			uploadConn = c.uploadRawPool.Get()
+			newConnection := uploadConn == nil
+			if newConnection {
+				uploadConn, err = c.dialUploadConn(context.WithoutCancel(ctx))
+				if err != nil {
+					return err
+				}
+			}
+
+			_, err = uploadConn.(net.Conn).Write(requestBytes.Bytes())
+
+			// if the write failed, we try another connection from
+			// the pool, until the write on a new connection fails.
+			// failed writes to a pooled connection are normal when
+			// the connection has been closed in the meantime.
+			if err == nil {
+				break
+			} else if newConnection {
+				return err
+			}
+		}
+
+		c.uploadRawPool.Put(uploadConn)
+	}
+
+	return nil
+}
diff --git a/transport/internet/splithttp/dialer.go b/transport/internet/splithttp/dialer.go
index 1a927a49..3a7ce641 100644
--- a/transport/internet/splithttp/dialer.go
+++ b/transport/internet/splithttp/dialer.go
@@ -1,13 +1,10 @@
 package splithttp
 
 import (
-	"bytes"
 	"context"
 	gotls "crypto/tls"
 	"io"
-	gonet "net"
 	"net/http"
-	"net/http/httptrace"
 	"net/url"
 	"strconv"
 	"sync"
@@ -17,10 +14,10 @@ import (
 	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
-	"github.com/xtls/xray-core/common/signal/done"
 	"github.com/xtls/xray-core/common/signal/semaphore"
 	"github.com/xtls/xray-core/common/uuid"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/browser_dialer"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tls"
 	"github.com/xtls/xray-core/transport/pipe"
@@ -32,32 +29,31 @@ type dialerConf struct {
 	*internet.MemoryStreamConfig
 }
 
-type reusedClient struct {
-	download *http.Client
-	upload   *http.Client
-	isH2     bool
-	// pool of net.Conn, created using dialUploadConn
-	uploadRawPool  *sync.Pool
-	dialUploadConn func(ctxInner context.Context) (net.Conn, error)
-}
-
 var (
-	globalDialerMap    map[dialerConf]reusedClient
+	globalDialerMap    map[dialerConf]DialerClient
 	globalDialerAccess sync.Mutex
 )
 
-func getHTTPClient(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) reusedClient {
+func getHTTPClient(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) DialerClient {
+	if browser_dialer.HasBrowserDialer() {
+		return &BrowserDialerClient{}
+	}
+
 	globalDialerAccess.Lock()
 	defer globalDialerAccess.Unlock()
 
 	if globalDialerMap == nil {
-		globalDialerMap = make(map[dialerConf]reusedClient)
+		globalDialerMap = make(map[dialerConf]DialerClient)
 	}
 
 	if client, found := globalDialerMap[dialerConf{dest, streamSettings}]; found {
 		return client
 	}
 
+	if browser_dialer.HasBrowserDialer() {
+		return &BrowserDialerClient{}
+	}
+
 	tlsConfig := tls.ConfigFromStreamSettings(streamSettings)
 	isH2 := tlsConfig != nil && !(len(tlsConfig.NextProtocol) == 1 && tlsConfig.NextProtocol[0] == "http/1.1")
 
@@ -116,7 +112,8 @@ func getHTTPClient(ctx context.Context, dest net.Destination, streamSettings *in
 		uploadTransport = nil
 	}
 
-	client := reusedClient{
+	client := &DefaultDialerClient{
+		transportConfig: streamSettings.ProtocolSettings.(*Config),
 		download: &http.Client{
 			Transport: downloadTransport,
 		},
@@ -160,80 +157,9 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 
 	httpClient := getHTTPClient(ctx, dest, streamSettings)
 
-	var remoteAddr gonet.Addr
-	var localAddr gonet.Addr
-	// this is done when the TCP/UDP connection to the server was established,
-	// and we can unblock the Dial function and print correct net addresses in
-	// logs
-	gotConn := done.New()
-
-	var downResponse io.ReadCloser
-	gotDownResponse := done.New()
-
 	sessionIdUuid := uuid.New()
 	sessionId := sessionIdUuid.String()
-
-	go func() {
-		trace := &httptrace.ClientTrace{
-			GotConn: func(connInfo httptrace.GotConnInfo) {
-				remoteAddr = connInfo.Conn.RemoteAddr()
-				localAddr = connInfo.Conn.LocalAddr()
-				gotConn.Close()
-			},
-		}
-
-		// in case we hit an error, we want to unblock this part
-		defer gotConn.Close()
-
-		req, err := http.NewRequestWithContext(
-			httptrace.WithClientTrace(context.WithoutCancel(ctx), trace),
-			"GET",
-			requestURL.String()+sessionId,
-			nil,
-		)
-		if err != nil {
-			errors.LogInfoInner(ctx, err, "failed to construct download http request")
-			gotDownResponse.Close()
-			return
-		}
-
-		req.Header = transportConfiguration.GetRequestHeader()
-
-		response, err := httpClient.download.Do(req)
-		gotConn.Close()
-		if err != nil {
-			errors.LogInfoInner(ctx, err, "failed to send download http request")
-			gotDownResponse.Close()
-			return
-		}
-
-		if response.StatusCode != 200 {
-			response.Body.Close()
-			errors.LogInfo(ctx, "invalid status code on download:", response.Status)
-			gotDownResponse.Close()
-			return
-		}
-
-		// skip "ooooooooook" response
-		trashHeader := []byte{0}
-		for {
-			_, err = io.ReadFull(response.Body, trashHeader)
-			if err != nil {
-				response.Body.Close()
-				errors.LogInfoInner(ctx, err, "failed to read initial response")
-				gotDownResponse.Close()
-				return
-			}
-			if trashHeader[0] == 'k' {
-				break
-			}
-		}
-
-		downResponse = response.Body
-		gotDownResponse.Close()
-	}()
-
-	uploadUrl := requestURL.String() + sessionId + "/"
+	baseURL := requestURL.String() + sessionId
 
 	uploadPipeReader, uploadPipeWriter := pipe.New(pipe.WithSizeLimit(maxUploadSize))
 
@@ -252,97 +178,55 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 
 			<-requestsLimiter.Wait()
 
-			url := uploadUrl + strconv.FormatInt(requestCounter, 10)
+			seq := requestCounter
 			requestCounter += 1
 
 			go func() {
 				defer requestsLimiter.Signal()
-				req, err := http.NewRequest("POST", url, &buf.MultiBufferContainer{MultiBuffer: chunk})
+
+				err := httpClient.SendUploadRequest(
+					context.WithoutCancel(ctx),
+					baseURL+"/"+strconv.FormatInt(seq, 10),
+					&buf.MultiBufferContainer{MultiBuffer: chunk},
+					int64(chunk.Len()),
+				)
+
 				if err != nil {
 					errors.LogInfoInner(ctx, err, "failed to send upload")
 					uploadPipeReader.Interrupt()
-					return
-				}
-
-				req.ContentLength = int64(chunk.Len())
-				req.Header = transportConfiguration.GetRequestHeader()
-
-				if httpClient.isH2 {
-					resp, err := httpClient.upload.Do(req)
-					if err != nil {
-						errors.LogInfoInner(ctx, err, "failed to send upload")
-						uploadPipeReader.Interrupt()
-						return
-					}
-					defer resp.Body.Close()
-
-					if resp.StatusCode != 200 {
-						errors.LogInfo(ctx, "failed to send upload, bad status code:", resp.Status)
-						uploadPipeReader.Interrupt()
-						return
-					}
-				} else {
-					var uploadConn any
-
-					// stringify the entire HTTP/1.1 request so it can be
-					// safely retried. if instead req.Write is called multiple
-					// times, the body is already drained after the first
-					// request
-					requestBytes := new(bytes.Buffer)
-					common.Must(req.Write(requestBytes))
-
-					for {
-						uploadConn = httpClient.uploadRawPool.Get()
-						newConnection := uploadConn == nil
-						if newConnection {
-							uploadConn, err = httpClient.dialUploadConn(context.WithoutCancel(ctx))
-							if err != nil {
-								errors.LogInfoInner(ctx, err, "failed to connect upload")
-								uploadPipeReader.Interrupt()
-								return
-							}
-						}
-
-						_, err = uploadConn.(net.Conn).Write(requestBytes.Bytes())
-
-						// if the write failed, we try another connection from
-						// the pool, until the write on a new connection fails.
-						// failed writes to a pooled connection are normal when
-						// the connection has been closed in the meantime.
-						if err == nil {
-							break
-						} else if newConnection {
-							errors.LogInfoInner(ctx, err, "failed to send upload")
-							uploadPipeReader.Interrupt()
-							return
-						}
-					}
-
-					httpClient.uploadRawPool.Put(uploadConn)
 				}
 			}()
 
 		}
 	}()
 
-	// we want to block Dial until we know the remote address of the server,
-	// for logging purposes
-	<-gotConn.Wait()
+	lazyRawDownload, remoteAddr, localAddr, err := httpClient.OpenDownload(context.WithoutCancel(ctx), baseURL)
+	if err != nil {
+		return nil, err
+	}
+
+	lazyDownload := &LazyReader{
+		CreateReader: func() (io.ReadCloser, error) {
+			// skip "ooooooooook" response
+			trashHeader := []byte{0}
+			for {
+				_, err := io.ReadFull(lazyRawDownload, trashHeader)
+				if err != nil {
+					return nil, errors.New("failed to read initial response").Base(err)
+				}
+				if trashHeader[0] == 'k' {
+					break
+				}
+			}
+
+			return lazyRawDownload, nil
+		},
+	}
 
 	// necessary in order to send larger chunks in upload
 	bufferedUploadPipeWriter := buf.NewBufferedWriter(uploadPipeWriter)
 	bufferedUploadPipeWriter.SetBuffered(false)
 
-	lazyDownload := &LazyReader{
-		CreateReader: func() (io.ReadCloser, error) {
-			<-gotDownResponse.Wait()
-			if downResponse == nil {
-				return nil, errors.New("downResponse failed")
-			}
-			return downResponse, nil
-		},
-	}
-
 	conn := splitConn{
 		writer:     bufferedUploadPipeWriter,
 		reader:     lazyDownload,
diff --git a/transport/internet/splithttp/hub.go b/transport/internet/splithttp/hub.go
index f71709ed..27fab68d 100644
--- a/transport/internet/splithttp/hub.go
+++ b/transport/internet/splithttp/hub.go
@@ -32,7 +32,7 @@ type requestHandler struct {
 }
 
 type httpSession struct {
-	uploadQueue *UploadQueue
+	uploadQueue *uploadQueue
 	// for as long as the GET request is not opened by the client, this will be
 	// open ("undone"), and the session may be expired within a certain TTL.
 	// after the client connects, this becomes "done" and the session lives as
@@ -163,7 +163,7 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 		writer.Header().Set("X-Accel-Buffering", "no")
 		// magic header to make the HTTP middle box consider this as SSE to disable buffer
 		writer.Header().Set("Content-Type", "text/event-stream")
-		
+
 		writer.WriteHeader(http.StatusOK)
 		// send a chunk immediately to enable CDN streaming.
 		// many CDN buffer the response headers until the origin starts sending
diff --git a/transport/internet/splithttp/upload_queue.go b/transport/internet/splithttp/upload_queue.go
index 4737b811..2d1fb5f4 100644
--- a/transport/internet/splithttp/upload_queue.go
+++ b/transport/internet/splithttp/upload_queue.go
@@ -15,7 +15,7 @@ type Packet struct {
 	Seq     uint64
 }
 
-type UploadQueue struct {
+type uploadQueue struct {
 	pushedPackets chan Packet
 	heap          uploadHeap
 	nextSeq       uint64
@@ -23,8 +23,8 @@ type UploadQueue struct {
 	maxPackets    int
 }
 
-func NewUploadQueue(maxPackets int) *UploadQueue {
-	return &UploadQueue{
+func NewUploadQueue(maxPackets int) *uploadQueue {
+	return &uploadQueue{
 		pushedPackets: make(chan Packet, maxPackets),
 		heap:          uploadHeap{},
 		nextSeq:       0,
@@ -33,7 +33,7 @@ func NewUploadQueue(maxPackets int) *UploadQueue {
 	}
 }
 
-func (h *UploadQueue) Push(p Packet) error {
+func (h *uploadQueue) Push(p Packet) error {
 	if h.closed {
 		return errors.New("splithttp packet queue closed")
 	}
@@ -42,13 +42,13 @@ func (h *UploadQueue) Push(p Packet) error {
 	return nil
 }
 
-func (h *UploadQueue) Close() error {
+func (h *uploadQueue) Close() error {
 	h.closed = true
 	close(h.pushedPackets)
 	return nil
 }
 
-func (h *UploadQueue) Read(b []byte) (int, error) {
+func (h *uploadQueue) Read(b []byte) (int, error) {
 	if h.closed {
 		return 0, io.EOF
 	}
diff --git a/transport/internet/websocket/connection.go b/transport/internet/websocket/connection.go
index 395c2f01..0bb5dd7b 100644
--- a/transport/internet/websocket/connection.go
+++ b/transport/internet/websocket/connection.go
@@ -15,16 +15,14 @@ var _ buf.Writer = (*connection)(nil)
 
 // connection is a wrapper for net.Conn over WebSocket connection.
 type connection struct {
-	conn       *websocket.Conn
-	reader     io.Reader
-	remoteAddr net.Addr
+	conn   *websocket.Conn
+	reader io.Reader
 }
 
-func newConnection(conn *websocket.Conn, remoteAddr net.Addr, extraReader io.Reader) *connection {
+func NewConnection(conn *websocket.Conn, remoteAddr net.Addr, extraReader io.Reader) *connection {
 	return &connection{
-		conn:       conn,
-		remoteAddr: remoteAddr,
-		reader:     extraReader,
+		conn:   conn,
+		reader: extraReader,
 	}
 }
 
@@ -92,7 +90,7 @@ func (c *connection) LocalAddr() net.Addr {
 }
 
 func (c *connection) RemoteAddr() net.Addr {
-	return c.remoteAddr
+	return c.conn.RemoteAddr()
 }
 
 func (c *connection) SetDeadline(t time.Time) error {
diff --git a/transport/internet/websocket/dialer.go b/transport/internet/websocket/dialer.go
index 7003928b..aa15c1a6 100644
--- a/transport/internet/websocket/dialer.go
+++ b/transport/internet/websocket/dialer.go
@@ -1,54 +1,23 @@
 package websocket
 
 import (
-	"bytes"
 	"context"
 	_ "embed"
 	"encoding/base64"
 	"io"
 	gonet "net"
-	"net/http"
 	"time"
 
 	"github.com/gorilla/websocket"
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
-	"github.com/xtls/xray-core/common/platform"
-	"github.com/xtls/xray-core/common/uuid"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/browser_dialer"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tls"
 )
 
-//go:embed dialer.html
-var webpage []byte
-
-var conns chan *websocket.Conn
-
-func init() {
-	addr := platform.NewEnvFlag(platform.BrowserDialerAddress).GetValue(func() string { return "" })
-	if addr != "" {
-		token := uuid.New()
-		csrfToken := token.String()
-		webpage = bytes.ReplaceAll(webpage, []byte("csrfToken"), []byte(csrfToken))
-		conns = make(chan *websocket.Conn, 256)
-		go http.ListenAndServe(addr, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			if r.URL.Path == "/websocket" {
-				if r.URL.Query().Get("token") == csrfToken {
-					if conn, err := upgrader.Upgrade(w, r, nil); err == nil {
-						conns <- conn
-					} else {
-						errors.LogError(context.Background(), "Browser dialer http upgrade unexpected error")
-					}
-				}
-			} else {
-				w.Write(webpage)
-			}
-		}))
-	}
-}
-
 // Dial dials a WebSocket connection to the given destination.
 func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (stat.Connection, error) {
 	errors.LogInfo(ctx, "creating connection to ", dest)
@@ -98,18 +67,18 @@ func dialWebSocket(ctx context.Context, dest net.Destination, streamSettings *in
 				// Like the NetDial in the dialer
 				pconn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
 				if err != nil {
-					errors.LogErrorInner(ctx, err, "failed to dial to " + addr)
+					errors.LogErrorInner(ctx, err, "failed to dial to "+addr)
 					return nil, err
 				}
 				// TLS and apply the handshake
 				cn := tls.UClient(pconn, tlsConfig, fingerprint).(*tls.UConn)
 				if err := cn.WebsocketHandshakeContext(ctx); err != nil {
-					errors.LogErrorInner(ctx, err, "failed to dial to " + addr)
+					errors.LogErrorInner(ctx, err, "failed to dial to "+addr)
 					return nil, err
 				}
 				if !tlsConfig.InsecureSkipVerify {
 					if err := cn.VerifyHostname(tlsConfig.ServerName); err != nil {
-						errors.LogErrorInner(ctx, err, "failed to dial to " + addr)
+						errors.LogErrorInner(ctx, err, "failed to dial to "+addr)
 						return nil, err
 					}
 				}
@@ -124,28 +93,13 @@ func dialWebSocket(ctx context.Context, dest net.Destination, streamSettings *in
 	}
 	uri := protocol + "://" + host + wsSettings.GetNormalizedPath()
 
-	if conns != nil {
-		data := []byte(uri)
-		if ed != nil {
-			data = append(data, " "+base64.RawURLEncoding.EncodeToString(ed)...)
-		}
-		var conn *websocket.Conn
-		for {
-			conn = <-conns
-			if conn.WriteMessage(websocket.TextMessage, data) != nil {
-				conn.Close()
-			} else {
-				break
-			}
-		}
-		if _, p, err := conn.ReadMessage(); err != nil {
-			conn.Close()
+	if browser_dialer.HasBrowserDialer() {
+		conn, err := browser_dialer.DialWS(uri, ed)
+		if err != nil {
 			return nil, err
-		} else if s := string(p); s != "ok" {
-			conn.Close()
-			return nil, errors.New(s)
 		}
-		return newConnection(conn, conn.RemoteAddr(), nil), nil
+
+		return NewConnection(conn, conn.RemoteAddr(), nil), nil
 	}
 
 	header := wsSettings.GetRequestHeader()
@@ -163,7 +117,7 @@ func dialWebSocket(ctx context.Context, dest net.Destination, streamSettings *in
 		return nil, errors.New("failed to dial to (", uri, "): ", reason).Base(err)
 	}
 
-	return newConnection(conn, conn.RemoteAddr(), nil), nil
+	return NewConnection(conn, conn.RemoteAddr(), nil), nil
 }
 
 type delayDialConn struct {
diff --git a/transport/internet/websocket/dialer.html b/transport/internet/websocket/dialer.html
deleted file mode 100644
index 39b14441..00000000
--- a/transport/internet/websocket/dialer.html
+++ /dev/null
@@ -1,59 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-	<title>Browser Dialer</title>
-</head>
-<body>
-	<script>
-		// Copyright (c) 2021 XRAY. Mozilla Public License 2.0.
-		var url = "ws://" + window.location.host + "/websocket?token=csrfToken"
-		var count = 0
-		setInterval(check, 1000)
-		function check() {
-			if (count <= 0) {
-				count += 1
-				console.log("Prepare", url)
-				var ws = new WebSocket(url)
-				// arraybuffer is significantly faster in chrome than default
-				// blob, tested with chrome 123
-				ws.binaryType = "arraybuffer";
-				var wss = undefined
-				var first = true
-				ws.onmessage = function (event) {
-					if (first) {
-						first = false
-						count -= 1
-						var arr = event.data.split(" ")
-						console.log("Dial", arr[0], arr[1])
-						wss = new WebSocket(arr[0], arr[1])
-						wss.binaryType = "arraybuffer";
-						var opened = false
-						wss.onopen = function (event) {
-							opened = true
-							ws.send("ok")
-						}
-						wss.onmessage = function (event) {
-							ws.send(event.data)
-						}
-						wss.onclose = function (event) {
-							ws.close()
-						}
-						wss.onerror = function (event) {
-							!opened && ws.send("fail")
-							wss.close()
-						}
-						check()
-					} else wss.send(event.data)
-				}
-				ws.onclose = function (event) {
-					if (first) count -= 1
-					else wss.close()
-				}
-				ws.onerror = function (event) {
-					ws.close()
-				}
-			}
-		}
-	</script>
-</body>
-</html>
diff --git a/transport/internet/websocket/hub.go b/transport/internet/websocket/hub.go
index 6d363a68..6e07d9a0 100644
--- a/transport/internet/websocket/hub.go
+++ b/transport/internet/websocket/hub.go
@@ -73,7 +73,7 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 		}
 	}
 
-	h.ln.addConn(newConnection(conn, remoteAddr, extraReader))
+	h.ln.addConn(NewConnection(conn, remoteAddr, extraReader))
 }
 
 type Listener struct {