From ce6c0dc690c32056bc1faabac97112d306b9f0c3 Mon Sep 17 00:00:00 2001
From: RPRX <63339210+RPRX@users.noreply.github.com>
Date: Mon, 6 Jan 2025 14:06:11 +0000
Subject: [PATCH] XHTTP XMUX: Abandon `client` if `client.Do(req)` failed
 (#4253)

https://github.com/XTLS/Xray-core/commit/51769fdde1ca663dcb08d942618e480bee13109f
---
 transport/internet/splithttp/client.go | 25 +++++++++++++++----------
 transport/internet/splithttp/config.go |  5 ++++-
 transport/internet/splithttp/dialer.go |  6 +++---
 transport/internet/splithttp/hub.go    | 14 ++++++++++++++
 4 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/transport/internet/splithttp/client.go b/transport/internet/splithttp/client.go
index c6cfee55..23166536 100644
--- a/transport/internet/splithttp/client.go
+++ b/transport/internet/splithttp/client.go
@@ -55,11 +55,11 @@ func (c *DefaultDialerClient) OpenStream(ctx context.Context, url string, body i
 		},
 	})
 
-	method := "GET"
+	method := "GET" // stream-down
 	if body != nil {
-		method = "POST"
+		method = "POST" // stream-up/one
 	}
-	req, _ := http.NewRequestWithContext(ctx, method, url, body)
+	req, _ := http.NewRequestWithContext(context.WithoutCancel(ctx), method, url, body)
 	req.Header = c.transportConfig.GetRequestHeader()
 	if method == "POST" && !c.transportConfig.NoGRPCHeader {
 		req.Header.Set("Content-Type", "application/grpc")
@@ -69,17 +69,20 @@ func (c *DefaultDialerClient) OpenStream(ctx context.Context, url string, body i
 	go func() {
 		resp, err := c.client.Do(req)
 		if err != nil {
+			if !uploadOnly {
+				c.closed = true
+			}
 			errors.LogInfoInner(ctx, err, "failed to "+method+" "+url)
 			gotConn.Close()
 			wrc.Close()
 			return
 		}
 		if resp.StatusCode != 200 && !uploadOnly {
-			// c.closed = true
 			errors.LogInfo(ctx, "unexpected status ", resp.StatusCode)
 		}
-		if resp.StatusCode != 200 || uploadOnly {
-			resp.Body.Close()
+		if resp.StatusCode != 200 || uploadOnly { // stream-up
+			io.Copy(io.Discard, resp.Body)
+			resp.Body.Close() // if it is called immediately, the upload will be interrupted also
 			wrc.Close()
 			return
 		}
@@ -91,7 +94,7 @@ func (c *DefaultDialerClient) OpenStream(ctx context.Context, url string, body i
 }
 
 func (c *DefaultDialerClient) PostPacket(ctx context.Context, url string, body io.Reader, contentLength int64) error {
-	req, err := http.NewRequestWithContext(ctx, "POST", url, body)
+	req, err := http.NewRequestWithContext(context.WithoutCancel(ctx), "POST", url, body)
 	if err != nil {
 		return err
 	}
@@ -101,13 +104,14 @@ func (c *DefaultDialerClient) PostPacket(ctx context.Context, url string, body i
 	if c.httpVersion != "1.1" {
 		resp, err := c.client.Do(req)
 		if err != nil {
+			c.closed = true
 			return err
 		}
 
+		io.Copy(io.Discard, resp.Body)
 		defer resp.Body.Close()
 
 		if resp.StatusCode != 200 {
-			// c.closed = true
 			return errors.New("bad status code:", resp.Status)
 		}
 	} else {
@@ -139,11 +143,12 @@ func (c *DefaultDialerClient) PostPacket(ctx context.Context, url string, body i
 				if h1UploadConn.UnreadedResponsesCount > 0 {
 					resp, err := http.ReadResponse(h1UploadConn.RespBufReader, req)
 					if err != nil {
+						c.closed = true
 						return fmt.Errorf("error while reading response: %s", err.Error())
 					}
+					io.Copy(io.Discard, resp.Body)
+					defer resp.Body.Close()
 					if resp.StatusCode != 200 {
-						// c.closed = true
-						// resp.Body.Close() // I'm not sure
 						return fmt.Errorf("got non-200 error response code: %d", resp.StatusCode)
 					}
 				}
diff --git a/transport/internet/splithttp/config.go b/transport/internet/splithttp/config.go
index 190cb633..a76bf0e4 100644
--- a/transport/internet/splithttp/config.go
+++ b/transport/internet/splithttp/config.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/transport/internet"
 )
 
@@ -36,10 +37,11 @@ func (c *Config) GetNormalizedQuery() string {
 	if query != "" {
 		query += "&"
 	}
+	query += "x_version=" + core.Version()
 
 	paddingLen := c.GetNormalizedXPaddingBytes().rand()
 	if paddingLen > 0 {
-		query += "x_padding=" + strings.Repeat("0", int(paddingLen))
+		query += "&x_padding=" + strings.Repeat("0", int(paddingLen))
 	}
 
 	return query
@@ -58,6 +60,7 @@ func (c *Config) WriteResponseHeader(writer http.ResponseWriter) {
 	// CORS headers for the browser dialer
 	writer.Header().Set("Access-Control-Allow-Origin", "*")
 	writer.Header().Set("Access-Control-Allow-Methods", "GET, POST")
+	writer.Header().Set("X-Version", core.Version())
 	paddingLen := c.GetNormalizedXPaddingBytes().rand()
 	if paddingLen > 0 {
 		writer.Header().Set("X-Padding", strings.Repeat("0", int(paddingLen)))
diff --git a/transport/internet/splithttp/dialer.go b/transport/internet/splithttp/dialer.go
index f33bb9e4..22f854cd 100644
--- a/transport/internet/splithttp/dialer.go
+++ b/transport/internet/splithttp/dialer.go
@@ -372,14 +372,14 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 		if xmuxClient != nil {
 			xmuxClient.LeftRequests.Add(-1)
 		}
-		conn.reader, conn.remoteAddr, conn.localAddr, _ = httpClient.OpenStream(context.WithoutCancel(ctx), requestURL.String(), reader, false)
+		conn.reader, conn.remoteAddr, conn.localAddr, _ = httpClient.OpenStream(ctx, requestURL.String(), reader, false)
 		return stat.Connection(&conn), nil
 	} else { // stream-down
 		var err error
 		if xmuxClient2 != nil {
 			xmuxClient2.LeftRequests.Add(-1)
 		}
-		conn.reader, conn.remoteAddr, conn.localAddr, err = httpClient2.OpenStream(context.WithoutCancel(ctx), requestURL2.String(), nil, false)
+		conn.reader, conn.remoteAddr, conn.localAddr, err = httpClient2.OpenStream(ctx, requestURL2.String(), nil, false)
 		if err != nil { // browser dialer only
 			return nil, err
 		}
@@ -454,7 +454,7 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 
 			go func() {
 				err := httpClient.PostPacket(
-					context.WithoutCancel(ctx),
+					ctx,
 					url.String(),
 					&buf.MultiBufferContainer{MultiBuffer: chunk},
 					int64(chunk.Len()),
diff --git a/transport/internet/splithttp/hub.go b/transport/internet/splithttp/hub.go
index b7c5098b..0d8c20da 100644
--- a/transport/internet/splithttp/hub.go
+++ b/transport/internet/splithttp/hub.go
@@ -1,6 +1,7 @@
 package splithttp
 
 import (
+	"bytes"
 	"context"
 	"crypto/tls"
 	"io"
@@ -102,6 +103,12 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 
 	h.config.WriteResponseHeader(writer)
 
+	clientVer := []int{0, 0, 0}
+	x_version := strings.Split(request.URL.Query().Get("x_version"), ".")
+	for j := 0; j < 3 && len(x_version) > j; j++ {
+		clientVer[j], _ = strconv.Atoi(x_version[j])
+	}
+
 	validRange := h.config.GetNormalizedXPaddingBytes()
 	x_padding := int32(len(request.URL.Query().Get("x_padding")))
 	if validRange.To > 0 && (x_padding < validRange.From || x_padding > validRange.To) {
@@ -160,6 +167,13 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 				writer.WriteHeader(http.StatusConflict)
 			} else {
 				writer.WriteHeader(http.StatusOK)
+				if request.ProtoMajor != 1 && len(clientVer) > 0 && clientVer[0] >= 25 {
+					paddingLen := h.config.GetNormalizedXPaddingBytes().rand()
+					if paddingLen > 0 {
+						writer.Write(bytes.Repeat([]byte{'0'}, int(paddingLen)))
+					}
+					writer.(http.Flusher).Flush()
+				}
 				<-request.Context().Done()
 			}
 			return