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")) {

internal/stream/stream.go

@@ -384,7 +384,7 @@ func (c *headCache) read(p []byte) (n int, err error) {
 			n, err = lr.Read(buf[off:])
 			off += n
 			c.cur += int64(n)
-			if err == io.EOF && n == int(bufL) {
+			if err == io.EOF && off == int(bufL) {
 				err = nil
 			}
 			if err != nil {
@@ -468,7 +468,7 @@ func (r *RangeReadReadAtSeeker) getReaderAtOffset(off int64) (*readerCur, error)
 		}
 	}
 	if rc != nil && off-rc.cur <= utils.MB {
-		n, err := utils.CopyWithBufferN(utils.NullWriter{}, rc.reader, off-rc.cur)
+		n, err := utils.CopyWithBufferN(io.Discard, rc.reader, off-rc.cur)
 		rc.cur += n
 		if err == io.EOF && rc.cur == off {
 			err = nil

internal/stream/util.go

@@ -3,13 +3,13 @@ package stream
 import (
 	"context"
 	"fmt"
-	"github.com/alist-org/alist/v3/pkg/utils"
 	"io"
 	"net/http"
 
 	"github.com/alist-org/alist/v3/internal/model"
 	"github.com/alist-org/alist/v3/internal/net"
 	"github.com/alist-org/alist/v3/pkg/http_range"
+	"github.com/alist-org/alist/v3/pkg/utils"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -19,7 +19,11 @@ func GetRangeReadCloserFromLink(size int64, link *model.Link) (model.RangeReadCl
 	}
 	rangeReaderFunc := func(ctx context.Context, r http_range.Range) (io.ReadCloser, error) {
 		if link.Concurrency != 0 || link.PartSize != 0 {
-			header := net.ProcessHeader(http.Header{}, link.Header)
+			requestHeader := ctx.Value("request_header")
+			if requestHeader == nil {
+				requestHeader = &http.Header{}
+			}
+			header := net.ProcessHeader(*(requestHeader.(*http.Header)), link.Header)
 			down := net.NewDownloader(func(d *net.Downloader) {
 				d.Concurrency = link.Concurrency
 				d.PartSize = link.PartSize
@@ -60,7 +64,11 @@ func GetRangeReadCloserFromLink(size int64, link *model.Link) (model.RangeReadCl
 }
 
 func RequestRangedHttp(ctx context.Context, link *model.Link, offset, length int64) (*http.Response, error) {
-	header := net.ProcessHeader(http.Header{}, link.Header)
+	requestHeader := ctx.Value("request_header")
+	if requestHeader == nil {
+		requestHeader = &http.Header{}
+	}
+	header := net.ProcessHeader(*(requestHeader.(*http.Header)), link.Header)
 	header = http_range.ApplyRangeToHttpHeader(http_range.Range{Start: offset, Length: length}, header)
 
 	return net.RequestHttp(ctx, "GET", header, link.URL)