XHTTP server: Add scStreamUpServerSecs, enabled by default

infra/conf/transport_internet.go

@@ -231,6 +231,7 @@ type SplitHTTPConfig struct {
 	ScMaxEachPostBytes   Int32Range        `json:"scMaxEachPostBytes"`
 	ScMinPostsIntervalMs Int32Range        `json:"scMinPostsIntervalMs"`
 	ScMaxBufferedPosts   int64             `json:"scMaxBufferedPosts"`
+	ScStreamUpServerSecs Int32Range        `json:"scStreamUpServerSecs"`
 	Xmux                 XmuxConfig        `json:"xmux"`
 	DownloadSettings     *StreamConfig     `json:"downloadSettings"`
 	Extra                json.RawMessage   `json:"extra"`
@@ -280,6 +281,10 @@ func (c *SplitHTTPConfig) Build() (proto.Message, error) {
 		}
 	}
 
+	if c.XPaddingBytes != (Int32Range{}) && (c.XPaddingBytes.From <= 0 || c.XPaddingBytes.To <= 0) {
+		return nil, errors.New("xPaddingBytes cannot be disabled")
+	}
+
 	if c.Xmux.MaxConnections.To > 0 && c.Xmux.MaxConcurrency.To > 0 {
 		return nil, errors.New("maxConnections cannot be specified together with maxConcurrency")
 	}
@@ -303,6 +308,7 @@ func (c *SplitHTTPConfig) Build() (proto.Message, error) {
 		ScMaxEachPostBytes:   newRangeConfig(c.ScMaxEachPostBytes),
 		ScMinPostsIntervalMs: newRangeConfig(c.ScMinPostsIntervalMs),
 		ScMaxBufferedPosts:   c.ScMaxBufferedPosts,
+		ScStreamUpServerSecs: newRangeConfig(c.ScStreamUpServerSecs),
 		Xmux: &splithttp.XmuxConfig{
 			MaxConcurrency:   newRangeConfig(c.Xmux.MaxConcurrency),
 			MaxConnections:   newRangeConfig(c.Xmux.MaxConnections),

transport/internet/splithttp/browser_client.go

@@ -24,7 +24,7 @@ func (c *BrowserDialerClient) OpenStream(ctx context.Context, url string, body i
 		return nil, nil, nil, errors.New("bidirectional streaming for browser dialer not implemented yet")
 	}
 
-	conn, err := browser_dialer.DialGet(url, c.transportConfig.GetRequestHeader())
+	conn, err := browser_dialer.DialGet(url, c.transportConfig.GetRequestHeader(url))
 	dummyAddr := &gonet.IPAddr{}
 	if err != nil {
 		return nil, dummyAddr, dummyAddr, err
@@ -39,7 +39,7 @@ func (c *BrowserDialerClient) PostPacket(ctx context.Context, url string, body i
 		return err
 	}
 
-	err = browser_dialer.DialPost(url, c.transportConfig.GetRequestHeader(), bytes)
+	err = browser_dialer.DialPost(url, c.transportConfig.GetRequestHeader(url), bytes)
 	if err != nil {
 		return err
 	}

transport/internet/splithttp/client.go

@@ -60,7 +60,7 @@ func (c *DefaultDialerClient) OpenStream(ctx context.Context, url string, body i
 		method = "POST" // stream-up/one
 	}
 	req, _ := http.NewRequestWithContext(context.WithoutCancel(ctx), method, url, body)
-	req.Header = c.transportConfig.GetRequestHeader()
+	req.Header = c.transportConfig.GetRequestHeader(url)
 	if method == "POST" && !c.transportConfig.NoGRPCHeader {
 		req.Header.Set("Content-Type", "application/grpc")
 	}
@@ -69,10 +69,10 @@ func (c *DefaultDialerClient) OpenStream(ctx context.Context, url string, body i
 	go func() {
 		resp, err := c.client.Do(req)
 		if err != nil {
-			if !uploadOnly {
+			if !uploadOnly { // stream-down is enough
 				c.closed = true
+				errors.LogInfoInner(ctx, err, "failed to "+method+" "+url)
 			}
-			errors.LogInfoInner(ctx, err, "failed to "+method+" "+url)
 			gotConn.Close()
 			wrc.Close()
 			return
@@ -99,7 +99,7 @@ func (c *DefaultDialerClient) PostPacket(ctx context.Context, url string, body i
 		return err
 	}
 	req.ContentLength = contentLength
-	req.Header = c.transportConfig.GetRequestHeader()
+	req.Header = c.transportConfig.GetRequestHeader(url)
 
 	if c.httpVersion != "1.1" {
 		resp, err := c.client.Do(req)

transport/internet/splithttp/config.go

@@ -8,12 +8,9 @@ import (
 	"strings"
 
 	"github.com/xtls/xray-core/common"
-	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/transport/internet"
 )
 
-const paddingQuery = "x_padding"
-
 func (c *Config) GetNormalizedPath() string {
 	pathAndQuery := strings.SplitN(c.Path, "?", 2)
 	path := pathAndQuery[0]
@@ -37,54 +34,40 @@ func (c *Config) GetNormalizedQuery() string {
 		query = pathAndQuery[1]
 	}
 
-	if query != "" {
-		query += "&"
-	}
-	query += "x_version=" + core.Version()
+	/*
+		if query != "" {
+			query += "&"
+		}
+		query += "x_version=" + core.Version()
+	*/
 
 	return query
 }
 
-func (c *Config) GetRequestHeader() http.Header {
+func (c *Config) GetRequestHeader(rawURL string) http.Header {
 	header := http.Header{}
 	for k, v := range c.Headers {
 		header.Add(k, v)
 	}
 
-	paddingLen := c.GetNormalizedXPaddingBytes().rand()
-	if paddingLen > 0 {
-		query, err := url.ParseQuery(c.GetNormalizedQuery())
-		if err != nil {
-			query = url.Values{}
-		}
-		// https://www.rfc-editor.org/rfc/rfc7541.html#appendix-B
-		// h2's HPACK Header Compression feature employs a huffman encoding using a static table.
-		// 'X' is assigned an 8 bit code, so HPACK compression won't change actual padding length on the wire.
-		// https://www.rfc-editor.org/rfc/rfc9204.html#section-4.1.2-2
-		// h3's similar QPACK feature uses the same huffman table.
-		query.Set(paddingQuery, strings.Repeat("X", int(paddingLen)))
-
-		referrer := url.URL{
-			Scheme:   "https", // maybe http actually, but this part is not being checked
-			Host:     c.Host,
-			Path:     c.GetNormalizedPath(),
-			RawQuery: query.Encode(),
-		}
+	u, _ := url.Parse(rawURL)
+	// https://www.rfc-editor.org/rfc/rfc7541.html#appendix-B
+	// h2's HPACK Header Compression feature employs a huffman encoding using a static table.
+	// 'X' is assigned an 8 bit code, so HPACK compression won't change actual padding length on the wire.
+	// https://www.rfc-editor.org/rfc/rfc9204.html#section-4.1.2-2
+	// h3's similar QPACK feature uses the same huffman table.
+	u.RawQuery = "x_padding=" + strings.Repeat("X", int(c.GetNormalizedXPaddingBytes().rand()))
+	header.Set("Referer", u.String())
 
-		header.Set("Referer", referrer.String())
-	}
 	return header
 }
 
 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("X", int(paddingLen)))
-	}
+	// writer.Header().Set("X-Version", core.Version())
+	writer.Header().Set("X-Padding", strings.Repeat("X", int(c.GetNormalizedXPaddingBytes().rand())))
 }
 
 func (c *Config) GetNormalizedXPaddingBytes() RangeConfig {
@@ -128,6 +111,17 @@ func (c *Config) GetNormalizedScMaxBufferedPosts() int {
 	return int(c.ScMaxBufferedPosts)
 }
 
+func (c *Config) GetNormalizedScStreamUpServerSecs() RangeConfig {
+	if c.ScStreamUpServerSecs == nil || c.ScStreamUpServerSecs.To == 0 {
+		return RangeConfig{
+			From: 20,
+			To:   80,
+		}
+	}
+
+	return *c.ScMinPostsIntervalMs
+}
+
 func (m *XmuxConfig) GetNormalizedMaxConcurrency() RangeConfig {
 	if m.MaxConcurrency == nil {
 		return RangeConfig{

transport/internet/splithttp/config.proto

@@ -33,6 +33,7 @@ message Config {
   RangeConfig scMaxEachPostBytes = 8;
   RangeConfig scMinPostsIntervalMs = 9;
   int64 scMaxBufferedPosts = 10;
-  XmuxConfig xmux = 11;
-  xray.transport.internet.StreamConfig downloadSettings = 12;
+  RangeConfig scStreamUpServerSecs = 11;
+  XmuxConfig xmux = 12;
+  xray.transport.internet.StreamConfig downloadSettings = 13;
 }

transport/internet/splithttp/hub.go

@@ -104,29 +104,28 @@ 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])
-	}
+	/*
+		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()
-	paddingLength := -1
+	paddingLength := 0
 
-	if referrerPadding := request.Header.Get("Referer"); referrerPadding != "" {
-		// Browser dialer cannot control the host part of referrer header, so only check the query
-		if referrerURL, err := url.Parse(referrerPadding); err == nil {
-			if query := referrerURL.Query(); query.Has(paddingQuery) {
-				paddingLength = len(query.Get(paddingQuery))
-			}
+	referrer := request.Header.Get("Referer")
+	if referrer != "" {
+		if referrerURL, err := url.Parse(referrer); err == nil {
+			// Browser dialer cannot control the host part of referrer header, so only check the query
+			paddingLength = len(referrerURL.Query().Get("x_padding"))
 		}
+	} else {
+		paddingLength = len(request.URL.Query().Get("x_padding"))
 	}
 
-	if paddingLength == -1 {
-		paddingLength = len(request.URL.Query().Get(paddingQuery))
-	}
-
-	if validRange.To > 0 && (int32(paddingLength) < validRange.From || int32(paddingLength) > validRange.To) {
+	if int32(paddingLength) < validRange.From || int32(paddingLength) > validRange.To {
 		errors.LogInfo(context.Background(), "invalid x_padding length:", int32(paddingLength))
 		writer.WriteHeader(http.StatusBadRequest)
 		return
@@ -181,13 +180,24 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 				errors.LogInfoInner(context.Background(), err, "failed to upload (PushReader)")
 				writer.WriteHeader(http.StatusConflict)
 			} else {
+				writer.Header().Set("X-Accel-Buffering", "no")
+				writer.Header().Set("Cache-Control", "no-store")
 				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()
+				scStreamUpServerSecs := h.config.GetNormalizedScStreamUpServerSecs()
+				if referrer != "" && scStreamUpServerSecs.To > 0 {
+					go func() {
+						defer func() {
+							recover()
+						}()
+						for {
+							_, err := writer.Write(bytes.Repeat([]byte{'X'}, int(h.config.GetNormalizedXPaddingBytes().rand())))
+							if err != nil {
+								break
+							}
+							writer.(http.Flusher).Flush()
+							time.Sleep(time.Duration(scStreamUpServerSecs.rand()) * time.Second)
+						}
+					}()
 				}
 				<-request.Context().Done()
 			}