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Diffstat (limited to '')
| -rw-r--r-- | modules/httplib/serve.go | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/modules/httplib/serve.go b/modules/httplib/serve.go new file mode 100644 index 0000000..2e3e6a7 --- /dev/null +++ b/modules/httplib/serve.go @@ -0,0 +1,237 @@ +// Copyright 2023 The Gitea Authors. All rights reserved. +// SPDX-License-Identifier: MIT + +package httplib + +import ( + "bytes" + "errors" + "fmt" + "io" + "net/http" + "net/url" + "path" + "path/filepath" + "strconv" + "strings" + "time" + + charsetModule "code.gitea.io/gitea/modules/charset" + "code.gitea.io/gitea/modules/container" + "code.gitea.io/gitea/modules/httpcache" + "code.gitea.io/gitea/modules/log" + "code.gitea.io/gitea/modules/setting" + "code.gitea.io/gitea/modules/typesniffer" + "code.gitea.io/gitea/modules/util" + + "github.com/klauspost/compress/gzhttp" +) + +type ServeHeaderOptions struct { + ContentType string // defaults to "application/octet-stream" + ContentTypeCharset string + ContentLength *int64 + Disposition string // defaults to "attachment" + Filename string + CacheDuration time.Duration // defaults to 5 minutes + LastModified time.Time +} + +// ServeSetHeaders sets necessary content serve headers +func ServeSetHeaders(w http.ResponseWriter, opts *ServeHeaderOptions) { + header := w.Header() + + skipCompressionExts := container.SetOf(".gz", ".bz2", ".zip", ".xz", ".zst", ".deb", ".apk", ".jar", ".png", ".jpg", ".webp") + if skipCompressionExts.Contains(strings.ToLower(path.Ext(opts.Filename))) { + w.Header().Add(gzhttp.HeaderNoCompression, "1") + } + + contentType := typesniffer.ApplicationOctetStream + if opts.ContentType != "" { + if opts.ContentTypeCharset != "" { + contentType = opts.ContentType + "; charset=" + strings.ToLower(opts.ContentTypeCharset) + } else { + contentType = opts.ContentType + } + } + header.Set("Content-Type", contentType) + header.Set("X-Content-Type-Options", "nosniff") + + if opts.ContentLength != nil { + header.Set("Content-Length", strconv.FormatInt(*opts.ContentLength, 10)) + } + + if opts.Filename != "" { + disposition := opts.Disposition + if disposition == "" { + disposition = "attachment" + } + + backslashEscapedName := strings.ReplaceAll(strings.ReplaceAll(opts.Filename, `\`, `\\`), `"`, `\"`) // \ -> \\, " -> \" + header.Set("Content-Disposition", fmt.Sprintf(`%s; filename="%s"; filename*=UTF-8''%s`, disposition, backslashEscapedName, url.PathEscape(opts.Filename))) + header.Set("Access-Control-Expose-Headers", "Content-Disposition") + } + + duration := opts.CacheDuration + if duration == 0 { + duration = 5 * time.Minute + } + httpcache.SetCacheControlInHeader(header, duration) + + if !opts.LastModified.IsZero() { + // http.TimeFormat required a UTC time, refer to https://pkg.go.dev/net/http#TimeFormat + header.Set("Last-Modified", opts.LastModified.UTC().Format(http.TimeFormat)) + } +} + +// ServeData download file from io.Reader +func setServeHeadersByFile(r *http.Request, w http.ResponseWriter, filePath string, mineBuf []byte) { + // do not set "Content-Length", because the length could only be set by callers, and it needs to support range requests + opts := &ServeHeaderOptions{ + Filename: path.Base(filePath), + } + + sniffedType := typesniffer.DetectContentType(mineBuf) + + // the "render" parameter came from year 2016: 638dd24c, it doesn't have clear meaning, so I think it could be removed later + isPlain := sniffedType.IsText() || r.FormValue("render") != "" + + if setting.MimeTypeMap.Enabled { + fileExtension := strings.ToLower(filepath.Ext(filePath)) + opts.ContentType = setting.MimeTypeMap.Map[fileExtension] + } + + if opts.ContentType == "" { + if sniffedType.IsBrowsableBinaryType() { + opts.ContentType = sniffedType.GetMimeType() + } else if isPlain { + opts.ContentType = "text/plain" + } else { + opts.ContentType = typesniffer.ApplicationOctetStream + } + } + + if isPlain { + charset, err := charsetModule.DetectEncoding(mineBuf) + if err != nil { + log.Error("Detect raw file %s charset failed: %v, using by default utf-8", filePath, err) + charset = "utf-8" + } + opts.ContentTypeCharset = strings.ToLower(charset) + } + + isSVG := sniffedType.IsSvgImage() + + // serve types that can present a security risk with CSP + if isSVG { + w.Header().Set("Content-Security-Policy", "default-src 'none'; style-src 'unsafe-inline'; sandbox") + } else if sniffedType.IsPDF() { + // no sandbox attribute for pdf as it breaks rendering in at least safari. this + // should generally be safe as scripts inside PDF can not escape the PDF document + // see https://bugs.chromium.org/p/chromium/issues/detail?id=413851 for more discussion + w.Header().Set("Content-Security-Policy", "default-src 'none'; style-src 'unsafe-inline'") + } + + opts.Disposition = "inline" + if isSVG && !setting.UI.SVG.Enabled { + opts.Disposition = "attachment" + } + + ServeSetHeaders(w, opts) +} + +const mimeDetectionBufferLen = 1024 + +func ServeContentByReader(r *http.Request, w http.ResponseWriter, filePath string, size int64, reader io.Reader) { + buf := make([]byte, mimeDetectionBufferLen) + n, err := util.ReadAtMost(reader, buf) + if err != nil { + http.Error(w, "serve content: unable to pre-read", http.StatusRequestedRangeNotSatisfiable) + return + } + if n >= 0 { + buf = buf[:n] + } + setServeHeadersByFile(r, w, filePath, buf) + + // reset the reader to the beginning + reader = io.MultiReader(bytes.NewReader(buf), reader) + + rangeHeader := r.Header.Get("Range") + + // if no size or no supported range, serve as 200 (complete response) + if size <= 0 || !strings.HasPrefix(rangeHeader, "bytes=") { + if size >= 0 { + w.Header().Set("Content-Length", strconv.FormatInt(size, 10)) + } + _, _ = io.Copy(w, reader) // just like http.ServeContent, not necessary to handle the error + return + } + + // do our best to support the minimal "Range" request (no support for multiple range: "Range: bytes=0-50, 100-150") + // + // GET /... + // Range: bytes=0-1023 + // + // HTTP/1.1 206 Partial Content + // Content-Range: bytes 0-1023/146515 + // Content-Length: 1024 + + _, rangeParts, _ := strings.Cut(rangeHeader, "=") + rangeBytesStart, rangeBytesEnd, found := strings.Cut(rangeParts, "-") + start, err := strconv.ParseInt(rangeBytesStart, 10, 64) + if start < 0 || start >= size { + err = errors.New("invalid start range") + } + if err != nil { + http.Error(w, err.Error(), http.StatusRequestedRangeNotSatisfiable) + return + } + end, err := strconv.ParseInt(rangeBytesEnd, 10, 64) + if rangeBytesEnd == "" && found { + err = nil + end = size - 1 + } + if end >= size { + end = size - 1 + } + if end < start { + err = errors.New("invalid end range") + } + if err != nil { + http.Error(w, err.Error(), http.StatusBadRequest) + return + } + + partialLength := end - start + 1 + w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", start, end, size)) + w.Header().Set("Content-Length", strconv.FormatInt(partialLength, 10)) + if _, err = io.CopyN(io.Discard, reader, start); err != nil { + http.Error(w, "serve content: unable to skip", http.StatusInternalServerError) + return + } + + w.WriteHeader(http.StatusPartialContent) + _, _ = io.CopyN(w, reader, partialLength) // just like http.ServeContent, not necessary to handle the error +} + +func ServeContentByReadSeeker(r *http.Request, w http.ResponseWriter, filePath string, modTime *time.Time, reader io.ReadSeeker) { + buf := make([]byte, mimeDetectionBufferLen) + n, err := util.ReadAtMost(reader, buf) + if err != nil { + http.Error(w, "serve content: unable to read", http.StatusInternalServerError) + return + } + if _, err = reader.Seek(0, io.SeekStart); err != nil { + http.Error(w, "serve content: unable to seek", http.StatusInternalServerError) + return + } + if n >= 0 { + buf = buf[:n] + } + setServeHeadersByFile(r, w, filePath, buf) + if modTime == nil { + modTime = &time.Time{} + } + http.ServeContent(w, r, path.Base(filePath), *modTime, reader) +} |