package handler import ( "fmt" "net/http" "strconv" "strings" "time" "github.com/gorilla/mux" "github.com/nspcc-dev/neofs-s3-gw/api" "github.com/nspcc-dev/neofs-s3-gw/api/layer" "go.uber.org/zap" ) type conditionalArgs struct { IfModifiedSince *time.Time IfUnmodifiedSince *time.Time IfMatch string IfNoneMatch string } type getObjectArgs struct { Conditional *conditionalArgs } func fetchRangeHeader(headers http.Header, fullSize uint64) (*layer.RangeParams, error) { const prefix = "bytes=" rangeHeader := headers.Get("Range") if len(rangeHeader) == 0 { return nil, nil } if !strings.HasPrefix(rangeHeader, prefix) { return nil, fmt.Errorf("unknown unit in range header") } arr := strings.Split(strings.TrimPrefix(rangeHeader, prefix), "-") if len(arr) != 2 || (len(arr[0]) == 0 && len(arr[1]) == 0) { return nil, fmt.Errorf("unknown byte-range-set") } var end, start uint64 var err0, err1 error base, bitSize := 10, 64 if len(arr[0]) == 0 { end, err1 = strconv.ParseUint(arr[1], base, bitSize) start = fullSize - end end = fullSize - 1 } else if len(arr[1]) == 0 { start, err0 = strconv.ParseUint(arr[0], base, bitSize) end = fullSize - 1 } else { start, err0 = strconv.ParseUint(arr[0], base, bitSize) end, err1 = strconv.ParseUint(arr[1], base, bitSize) } if err0 != nil || err1 != nil || start > end { return nil, fmt.Errorf("invalid Range header") } return &layer.RangeParams{Start: start, End: end}, nil } func writeHeaders(h http.Header, info *layer.ObjectInfo) { if len(info.ContentType) > 0 { h.Set(api.ContentType, info.ContentType) } h.Set(api.LastModified, info.Created.UTC().Format(http.TimeFormat)) h.Set(api.ContentLength, strconv.FormatInt(info.Size, 10)) h.Set(api.ETag, info.HashSum) for key, val := range info.Headers { h.Set(api.MetadataPrefix+key, val) } } func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) { var ( err error inf *layer.ObjectInfo params *layer.RangeParams req = mux.Vars(r) bkt = req["bucket"] obj = req["object"] rid = api.GetRequestID(r.Context()) ) args, err := parseGetObjectArgs(r.Header) if err != nil { writeError(w, r, h.log, "could not parse request params", rid, bkt, obj, err) return } if inf, err = h.obj.GetObjectInfo(r.Context(), bkt, obj); err != nil { writeError(w, r, h.log, "could not find object", rid, bkt, obj, err) return } if err = checkPreconditions(inf, args.Conditional); err != nil { api.WriteErrorResponse(r.Context(), w, err, r.URL) return } if params, err = fetchRangeHeader(r.Header, uint64(inf.Size)); err != nil { writeError(w, r, h.log, "could not parse range header", rid, bkt, obj, err) return } writeHeaders(w.Header(), inf) if params != nil { writeRangeHeaders(w, params, inf.Size) } getParams := &layer.GetObjectParams{ Bucket: inf.Bucket, Object: inf.Name, Writer: w, Range: params, } if err = h.obj.GetObject(r.Context(), getParams); err != nil { writeError(w, r, h.log, "could not get object", rid, bkt, obj, err) } } func checkPreconditions(inf *layer.ObjectInfo, args *conditionalArgs) error { if len(args.IfMatch) > 0 && args.IfMatch != inf.HashSum { return api.GetAPIError(api.ErrPreconditionFailed) } if len(args.IfNoneMatch) > 0 && args.IfNoneMatch == inf.HashSum { return api.GetAPIError(api.ErrNotModified) } if args.IfModifiedSince != nil && inf.Created.Before(*args.IfModifiedSince) { return api.GetAPIError(api.ErrNotModified) } if args.IfUnmodifiedSince != nil && inf.Created.After(*args.IfUnmodifiedSince) { if len(args.IfMatch) == 0 { return api.GetAPIError(api.ErrPreconditionFailed) } } return nil } func parseGetObjectArgs(headers http.Header) (*getObjectArgs, error) { var err error args := &conditionalArgs{ IfMatch: headers.Get(api.IfMatch), IfNoneMatch: headers.Get(api.IfNoneMatch), } if args.IfModifiedSince, err = parseHTTPTime(headers.Get(api.IfModifiedSince)); err != nil { return nil, err } if args.IfUnmodifiedSince, err = parseHTTPTime(headers.Get(api.IfUnmodifiedSince)); err != nil { return nil, err } return &getObjectArgs{Conditional: args}, nil } func parseHTTPTime(data string) (*time.Time, error) { if len(data) == 0 { return nil, nil } result, err := time.Parse(http.TimeFormat, data) if err != nil { return nil, fmt.Errorf("couldn't parse http time %s: %w", data, err) } return &result, nil } func writeRangeHeaders(w http.ResponseWriter, params *layer.RangeParams, size int64) { w.Header().Set("Accept-Ranges", "bytes") w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", params.Start, params.End, size)) w.WriteHeader(http.StatusPartialContent) } func writeError(w http.ResponseWriter, r *http.Request, log *zap.Logger, msg, rid, bkt, obj string, err error) { log.Error(msg, zap.String("request_id", rid), zap.String("bucket_name", bkt), zap.String("object_name", obj), zap.Error(err)) api.WriteErrorResponse(r.Context(), w, api.Error{ Code: api.GetAPIError(api.ErrInternalError).Code, Description: err.Error(), HTTPStatusCode: http.StatusInternalServerError, }, r.URL) }