refactor(net): pass request header (#8031 close #8008)

* refactor(net): pass request header

* feat(proxy): add `Etag` to response header

* refactor

internal/net/request.go

@@ -382,6 +382,9 @@ func (d *downloader) tryDownloadChunk(params *HttpRequestParams, ch *chunk) (int
 		if resp == nil {
 			return 0, err
 		}
+		if resp.StatusCode == http.StatusRequestedRangeNotSatisfiable {
+			return 0, err
+		}
 		if ch.id == 0 { //第1个任务 有限的重试，超过重试就会结束请求
 			switch resp.StatusCode {
 			default:

internal/net/serve.go

@@ -114,7 +114,7 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 
 	// 使用请求的Context
 	// 不然从sendContent读不到数据，即使请求断开CopyBuffer也会一直堵塞
-	ctx := r.Context()
+	ctx := context.WithValue(r.Context(), "request_header", &r.Header)
 	switch {
 	case len(ranges) == 0:
 		reader, err := RangeReadCloser.RangeRead(ctx, http_range.Range{Length: -1})

internal/net/util.go

@@ -71,6 +71,7 @@ func checkIfMatch(w http.ResponseWriter, r *http.Request) condResult {
 	if im == "" {
 		return condNone
 	}
+	r.Header.Del("If-Match")
 	for {
 		im = textproto.TrimString(im)
 		if len(im) == 0 {
@@ -98,7 +99,11 @@ func checkIfMatch(w http.ResponseWriter, r *http.Request) condResult {
 
 func checkIfUnmodifiedSince(r *http.Request, modtime time.Time) condResult {
 	ius := r.Header.Get("If-Unmodified-Since")
-	if ius == "" || isZeroTime(modtime) {
+	if ius == "" {
+		return condNone
+	}
+	r.Header.Del("If-Unmodified-Since")
+	if isZeroTime(modtime) {
 		return condNone
 	}
 	t, err := http.ParseTime(ius)
@@ -120,6 +125,7 @@ func checkIfNoneMatch(w http.ResponseWriter, r *http.Request) condResult {
 	if inm == "" {
 		return condNone
 	}
+	r.Header.Del("If-None-Match")
 	buf := inm
 	for {
 		buf = textproto.TrimString(buf)
@@ -150,7 +156,11 @@ func checkIfModifiedSince(r *http.Request, modtime time.Time) condResult {
 		return condNone
 	}
 	ims := r.Header.Get("If-Modified-Since")
-	if ims == "" || isZeroTime(modtime) {
+	if ims == "" {
+		return condNone
+	}
+	r.Header.Del("If-Modified-Since")
+	if isZeroTime(modtime) {
 		return condNone
 	}
 	t, err := http.ParseTime(ims)
@@ -174,6 +184,7 @@ func checkIfRange(w http.ResponseWriter, r *http.Request, modtime time.Time) con
 	if ir == "" {
 		return condNone
 	}
+	r.Header.Del("If-Range")
 	etag, _ := scanETag(ir)
 	if etag != "" {
 		if etagStrongMatch(etag, w.Header().Get("Etag")) {