267 lines
8 KiB
Go
267 lines
8 KiB
Go
package rpc
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import (
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"context"
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"errors"
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"io"
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"math"
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"net"
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"net/http"
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"strconv"
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"strings"
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"time"
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"github.com/gotd/td/tg"
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"telesrv/internal/domain"
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)
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// validFiniteCoord 校验坐标是有限值且在 [-bound, bound] 内（NaN/±Inf 一律拒绝）。
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func validFiniteCoord(v, bound float64) bool {
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return !math.IsNaN(v) && !math.IsInf(v, 0) && v >= -bound && v <= bound
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}
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// 本文件实现 upload.getWebFile。当前唯一真实路径是 geo/venue 消息的地图缩略图
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// （inputWebFileGeoPointLocation）：TDesktop 与 DrKLO Android 渲染位置消息时都会调它。
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// 地图图像由 files 服务提供：配置 Mapbox 代理时为真实静态地图（落盘缓存保证分片一致），
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// 否则确定性占位合成（见 app/files/maptile.go 与 maptile_proxy.go）；
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// access_hash 不做校验（发送时随机生成且未持久化，地图缩略图无机密性可言）。
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// URL 形态（inputWebFileLocation）只代理 inline registry 中已登记的 web document；
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// 任意客户端自造 URL/access_hash 仍显式拒绝，避免把服务端变成开放代理。
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// maxWebFileChunkLimit 与 upload.getFile 的单次上限一致，防止客户端超大 limit 放大内存。
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const (
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maxWebFileChunkLimit = maxUploadGetFileChunkLimit
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inlineWebFileFetchTimeout = 10 * time.Second
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)
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type inlineWebFileFetcher func(ctx context.Context, document domain.BotInlineWebDocument) ([]byte, string, error)
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var fetchInlineWebFile inlineWebFileFetcher = defaultFetchInlineWebFile
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func (r *Router) registerUploadWebFile(d *tg.ServerDispatcher) {
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d.OnUploadGetWebFile(r.onUploadGetWebFile)
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}
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func (r *Router) onUploadGetWebFile(ctx context.Context, req *tg.UploadGetWebFileRequest) (*tg.UploadWebFile, error) {
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if r.deps.Files == nil {
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return nil, notImplementedErr()
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}
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userID, ok, err := r.currentUserID(ctx)
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if err != nil {
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return nil, internalErr()
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}
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if !ok || userID == 0 {
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return nil, locationInvalidErr()
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}
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if req.Offset < 0 || req.Limit <= 0 || req.Limit > maxWebFileChunkLimit {
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return nil, limitInvalidErr()
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}
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if loc, ok := req.Location.(*tg.InputWebFileLocation); ok {
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return r.onUploadGetRegisteredWebFile(ctx, loc, req.Offset, req.Limit)
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}
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loc, ok := req.Location.(*tg.InputWebFileGeoPointLocation)
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if !ok {
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return nil, locationInvalidErr()
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}
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point, ok := loc.GeoPoint.(*tg.InputGeoPoint)
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// NaN 与所有比较都为 false，会穿过区间校验，必须显式拒绝（NaN/Inf 会污染缓存 key 与上游 URL）。
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if !ok || !validFiniteCoord(point.Lat, 90) || !validFiniteCoord(point.Long, 180) {
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return nil, locationInvalidErr()
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}
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full, mime := r.deps.Files.GeoMapTile(point.Lat, point.Long, loc.W, loc.H, loc.Zoom, loc.Scale)
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if len(full) == 0 {
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return nil, locationInvalidErr()
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}
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fileType := webFileStorageType(mime)
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if req.Offset >= len(full) {
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return &tg.UploadWebFile{
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Size: len(full),
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MimeType: mime,
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FileType: fileType,
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Mtime: int(r.clock.Now().Unix()),
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Bytes: []byte{},
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}, nil
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}
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end := req.Offset + req.Limit
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if end > len(full) {
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end = len(full)
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}
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return &tg.UploadWebFile{
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Size: len(full),
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MimeType: mime,
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FileType: fileType,
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Mtime: int(r.clock.Now().Unix()),
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Bytes: full[req.Offset:end],
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}, nil
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}
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func (r *Router) onUploadGetRegisteredWebFile(ctx context.Context, loc *tg.InputWebFileLocation, offset, limit int) (*tg.UploadWebFile, error) {
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if loc.URL == "" || loc.AccessHash == 0 {
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return nil, locationInvalidErr()
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}
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_, data, mime, err := r.registeredInlineWebDocumentBytes(ctx, loc.URL, loc.AccessHash)
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if err != nil {
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return nil, locationInvalidErr()
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}
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fileType := storageFileType(mime, data)
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if offset >= len(data) {
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return &tg.UploadWebFile{
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Size: len(data),
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MimeType: mime,
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FileType: fileType,
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Mtime: int(r.clock.Now().Unix()),
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Bytes: []byte{},
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}, nil
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}
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end := offset + limit
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if end > len(data) {
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end = len(data)
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}
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return &tg.UploadWebFile{
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Size: len(data),
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MimeType: mime,
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FileType: fileType,
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Mtime: int(r.clock.Now().Unix()),
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Bytes: append([]byte(nil), data[offset:end]...),
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}, nil
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}
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func (r *Router) registeredInlineWebDocumentBytes(ctx context.Context, url string, accessHash int64) (domain.BotInlineWebDocument, []byte, string, error) {
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document, data, mime, ok := r.inlines.webDocumentForDownloadContext(ctx, r.clock.Now(), url, accessHash)
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if !ok {
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return domain.BotInlineWebDocument{}, nil, "", locationInvalidErr()
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}
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if len(data) == 0 {
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fetched, fetchedMime, err := fetchInlineWebFile(ctx, document)
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if err != nil {
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return domain.BotInlineWebDocument{}, nil, "", err
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}
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if len(fetched) == 0 || len(fetched) > domain.MaxBotInlineWebSize {
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return domain.BotInlineWebDocument{}, nil, "", locationInvalidErr()
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}
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data = fetched
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mime = normalizeInlineWebFileMime(fetchedMime, data, document.MimeType)
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r.inlines.cacheWebDocumentBytesContext(ctx, r.clock.Now(), document.URL, document.AccessHash, data, mime)
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}
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if mime == "" {
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mime = document.MimeType
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}
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return document, data, mime, nil
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}
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func webFileStorageType(mime string) tg.StorageFileTypeClass {
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switch mime {
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case "image/jpeg":
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return &tg.StorageFileJpeg{}
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case "image/webp":
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return &tg.StorageFileWebp{}
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default:
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return &tg.StorageFilePng{}
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}
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}
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func defaultFetchInlineWebFile(ctx context.Context, document domain.BotInlineWebDocument) ([]byte, string, error) {
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if err := validateInlineWebURL(document.URL, true); err != nil {
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return nil, "", err
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}
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ctx, cancel := context.WithTimeout(ctx, inlineWebFileFetchTimeout)
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defer cancel()
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req, err := http.NewRequestWithContext(ctx, http.MethodGet, document.URL, nil)
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if err != nil {
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return nil, "", err
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}
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req.Header.Set("User-Agent", "telesrv-inline-webfile")
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client := &http.Client{
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Timeout: inlineWebFileFetchTimeout,
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Transport: &http.Transport{
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Proxy: nil,
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DialContext: safeExternalDialContext,
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},
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}
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resp, err := client.Do(req)
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if err != nil {
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return nil, "", err
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}
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defer resp.Body.Close()
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if resp.StatusCode < 200 || resp.StatusCode > 299 {
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return nil, "", errors.New("webfile fetch status " + strconv.Itoa(resp.StatusCode))
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}
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if resp.ContentLength > int64(domain.MaxBotInlineWebSize) {
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return nil, "", webDocumentSizeTooBigErr()
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}
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limited := io.LimitReader(resp.Body, int64(domain.MaxBotInlineWebSize)+1)
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data, err := io.ReadAll(limited)
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if err != nil {
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return nil, "", err
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}
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if len(data) > domain.MaxBotInlineWebSize {
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return nil, "", webDocumentSizeTooBigErr()
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}
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return data, resp.Header.Get("Content-Type"), nil
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}
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func safeExternalDialContext(ctx context.Context, network, address string) (net.Conn, error) {
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host, port, err := net.SplitHostPort(address)
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if err != nil {
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return nil, err
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}
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if port == "" {
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port = "443"
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}
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ips, err := net.DefaultResolver.LookupIPAddr(ctx, host)
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if err != nil {
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return nil, err
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}
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var lastErr error
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dialer := &net.Dialer{Timeout: 5 * time.Second}
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for _, candidate := range ips {
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if !safeExternalIP(candidate.IP) {
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lastErr = errors.New("unsafe webfile host")
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continue
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}
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conn, err := dialer.DialContext(ctx, network, net.JoinHostPort(candidate.IP.String(), port))
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if err == nil {
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return conn, nil
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}
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lastErr = err
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}
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if lastErr != nil {
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return nil, lastErr
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}
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return nil, errors.New("webfile host has no safe address")
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}
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func safeExternalIP(ip net.IP) bool {
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if ip == nil {
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return false
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}
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if ip.IsLoopback() || ip.IsPrivate() || ip.IsUnspecified() || ip.IsMulticast() ||
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ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
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return false
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}
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if v4 := ip.To4(); v4 != nil {
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first, second := v4[0], v4[1]
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if first == 0 || first >= 224 || first == 127 || first == 169 && second == 254 {
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return false
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}
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if first == 100 && second >= 64 && second <= 127 {
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return false
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}
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if first == 198 && (second == 18 || second == 19) {
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return false
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}
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}
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return true
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}
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func normalizeInlineWebFileMime(header string, data []byte, fallback string) string {
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mime := strings.TrimSpace(strings.Split(header, ";")[0])
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if !validInlineWebMime(mime) {
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mime = http.DetectContentType(data)
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}
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if !validInlineWebMime(mime) {
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mime = fallback
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}
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return mime
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}
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