fix(net): unexpected write

internal/net/serve.go

@@ -52,19 +52,19 @@ import (
 //
 // If the caller has set w's ETag header formatted per RFC 7232, section 2.3,
 // ServeHTTP uses it to handle requests using If-Match, If-None-Match, or If-Range.
-func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time.Time, size int64, RangeReadCloser model.RangeReadCloserIF) {
+func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time.Time, size int64, RangeReadCloser model.RangeReadCloserIF) error {
 	defer RangeReadCloser.Close()
 	setLastModified(w, modTime)
 	done, rangeReq := checkPreconditions(w, r, modTime)
 	if done {
-		return
+		return nil
 	}
 
 	if size < 0 {
 		// since too many functions need file size to work,
 		// will not implement the support of unknown file size here
 		http.Error(w, "negative content size not supported", http.StatusInternalServerError)
-		return
+		return nil
 	}
 
 	code := http.StatusOK
@@ -103,7 +103,7 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 		fallthrough
 	default:
 		http.Error(w, err.Error(), http.StatusRequestedRangeNotSatisfiable)
-		return
+		return nil
 	}
 
 	if sumRangesSize(ranges) > size {
@@ -124,7 +124,7 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 				code = http.StatusTooManyRequests
 			}
 			http.Error(w, err.Error(), code)
-			return
+			return nil
 		}
 		sendContent = reader
 	case len(ranges) == 1:
@@ -147,7 +147,7 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 				code = http.StatusTooManyRequests
 			}
 			http.Error(w, err.Error(), code)
-			return
+			return nil
 		}
 		sendSize = ra.Length
 		code = http.StatusPartialContent
@@ -205,9 +205,11 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 			if err == ErrExceedMaxConcurrency {
 				code = http.StatusTooManyRequests
 			}
-			http.Error(w, err.Error(), code)
+			w.WriteHeader(code)
+			return err
 		}
 	}
+	return nil
 }
 func ProcessHeader(origin, override http.Header) http.Header {
 	result := http.Header{}

server/common/proxy.go

@@ -39,11 +39,10 @@ func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.
 		return nil
 	} else if link.RangeReadCloser != nil {
 		attachHeader(w, file)
-		net.ServeHTTP(w, r, file.GetName(), file.ModTime(), file.GetSize(), &stream.RateLimitRangeReadCloser{
+		return net.ServeHTTP(w, r, file.GetName(), file.ModTime(), file.GetSize(), &stream.RateLimitRangeReadCloser{
 			RangeReadCloserIF: link.RangeReadCloser,
 			Limiter:           stream.ServerDownloadLimit,
 		})
-		return nil
 	} else if link.Concurrency != 0 || link.PartSize != 0 {
 		attachHeader(w, file)
 		size := file.GetSize()
@@ -66,11 +65,10 @@ func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.
 			rc, err := down.Download(ctx, req)
 			return rc, err
 		}
-		net.ServeHTTP(w, r, file.GetName(), file.ModTime(), file.GetSize(), &stream.RateLimitRangeReadCloser{
+		return net.ServeHTTP(w, r, file.GetName(), file.ModTime(), file.GetSize(), &stream.RateLimitRangeReadCloser{
 			RangeReadCloserIF: &model.RangeReadCloser{RangeReader: rangeReader},
 			Limiter:           stream.ServerDownloadLimit,
 		})
-		return nil
 	} else {
 		//transparent proxy
 		header := net.ProcessHeader(r.Header, link.Header)
@@ -90,10 +88,7 @@ func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.
 			Limiter: stream.ServerDownloadLimit,
 			Ctx:     r.Context(),
 		})
-		if err != nil {
-			return err
-		}
-		return nil
+		return err
 	}
 }
 func attachHeader(w http.ResponseWriter, file model.Obj) {
@@ -133,3 +128,29 @@ func ProxyRange(link *model.Link, size int64) {
 		link.RangeReadCloser = nil
 	}
 }
+
+type InterceptResponseWriter struct {
+	http.ResponseWriter
+	io.Writer
+}
+
+func (iw *InterceptResponseWriter) Write(p []byte) (int, error) {
+	return iw.Writer.Write(p)
+}
+
+type WrittenResponseWriter struct {
+	http.ResponseWriter
+	written bool
+}
+
+func (ww *WrittenResponseWriter) Write(p []byte) (int, error) {
+	n, err := ww.ResponseWriter.Write(p)
+	if !ww.written && n > 0 {
+		ww.written = true
+	}
+	return n, err
+}
+
+func (ww *WrittenResponseWriter) IsWritten() bool {
+	return ww.written
+}

server/handles/down.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"net/http"
 	stdpath "path"
 	"strconv"
 	"strings"
@@ -129,15 +128,16 @@ func localProxy(c *gin.Context, link *model.Link, file model.Obj, proxyRange boo
 	if proxyRange {
 		common.ProxyRange(link, file.GetSize())
 	}
+	Writer := &common.WrittenResponseWriter{ResponseWriter: c.Writer}
 
 	//优先处理md文件
 	if utils.Ext(file.GetName()) == "md" && setting.GetBool(conf.FilterReadMeScripts) {
-		w := c.Writer
 		buf := bytes.NewBuffer(make([]byte, 0, file.GetSize()))
-		err = common.Proxy(&proxyResponseWriter{ResponseWriter: w, Writer: buf}, c.Request, link, file)
+		w := &common.InterceptResponseWriter{ResponseWriter: Writer, Writer: buf}
+		err = common.Proxy(w, c.Request, link, file)
 		if err == nil && buf.Len() > 0 {
-			if w.Status() < 200 || w.Status() > 300 {
-				w.Write(buf.Bytes())
+			if c.Writer.Status() < 200 || c.Writer.Status() > 300 {
+				c.Writer.Write(buf.Bytes())
 				return
 			}
 
@@ -148,19 +148,23 @@ func localProxy(c *gin.Context, link *model.Link, file model.Obj, proxyRange boo
 				buf.Reset()
 				err = bluemonday.UGCPolicy().SanitizeReaderToWriter(&html, buf)
 				if err == nil {
-					w.Header().Set("Content-Length", strconv.FormatInt(int64(buf.Len()), 10))
-					w.Header().Set("Content-Type", "text/html; charset=utf-8")
-					_, err = utils.CopyWithBuffer(c.Writer, buf)
+					Writer.Header().Set("Content-Length", strconv.FormatInt(int64(buf.Len()), 10))
+					Writer.Header().Set("Content-Type", "text/html; charset=utf-8")
+					_, err = utils.CopyWithBuffer(Writer, buf)
 				}
 			}
 		}
 	} else {
-		err = common.Proxy(c.Writer, c.Request, link, file)
+		err = common.Proxy(Writer, c.Request, link, file)
 	}
-	if err != nil {
-		common.ErrorResp(c, err, 500, true)
+	if err == nil {
 		return
 	}
+	if Writer.IsWritten() {
+		log.Errorf("%s %s local proxy error: %+v", c.Request.Method, c.Request.URL.Path, err)
+	} else {
+		common.ErrorResp(c, err, 500, true)
+	}
 }
 
 // TODO need optimize
@@ -182,12 +186,3 @@ func canProxy(storage driver.Driver, filename string) bool {
 	}
 	return false
 }
-
-type proxyResponseWriter struct {
-	http.ResponseWriter
-	io.Writer
-}
-
-func (pw *proxyResponseWriter) Write(p []byte) (int, error) {
-	return pw.Writer.Write(p)
-}

server/webdav/webdav.go

@@ -24,7 +24,6 @@ import (
 	"github.com/alist-org/alist/v3/internal/sign"
 	"github.com/alist-org/alist/v3/pkg/utils"
 	"github.com/alist-org/alist/v3/server/common"
-	log "github.com/sirupsen/logrus"
 )
 
 type Handler struct {
@@ -59,7 +58,11 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			status, err = h.handleOptions(brw, r)
 		case "GET", "HEAD", "POST":
 			useBufferedWriter = false
-			status, err = h.handleGetHeadPost(w, r)
+			Writer := &common.WrittenResponseWriter{ResponseWriter: w}
+			status, err = h.handleGetHeadPost(Writer, r)
+			if status != 0 && Writer.IsWritten() {
+				status = 0
+			}
 		case "DELETE":
 			status, err = h.handleDelete(brw, r)
 		case "PUT":
@@ -247,8 +250,7 @@ func (h *Handler) handleGetHeadPost(w http.ResponseWriter, r *http.Request) (sta
 		}
 		err = common.Proxy(w, r, link, fi)
 		if err != nil {
-			log.Errorf("webdav proxy error: %+v", err)
-			return http.StatusInternalServerError, err
+			return http.StatusInternalServerError, fmt.Errorf("webdav proxy error: %+v", err)
 		}
 	} else if storage.GetStorage().WebdavProxy() && downProxyUrl != "" {
 		u := fmt.Sprintf("%s%s?sign=%s",