fixed the suffix range bug (bytes=-N for "last N bytes")

weed/s3api/s3api_object_handlers.go

@@ -439,8 +439,30 @@ func (s3a *S3ApiServer) streamFromVolumeServers(w http.ResponseWriter, r *http.R
 		rangeSpec := rangeHeader[6:]
 		parts := strings.Split(rangeSpec, "-")
 		if len(parts) == 2 {
-			startOffset := int64(0)
-			endOffset := totalSize - 1
+			var startOffset, endOffset int64
+
+			// Handle different Range formats:
+			// 1. "bytes=0-499" - first 500 bytes (parts[0]="0", parts[1]="499")
+			// 2. "bytes=500-" - from byte 500 to end (parts[0]="500", parts[1]="")
+			// 3. "bytes=-500" - last 500 bytes (parts[0]="", parts[1]="500")
+
+			if parts[0] == "" && parts[1] != "" {
+				// Suffix range: bytes=-N (last N bytes)
+				if suffixLen, err := strconv.ParseInt(parts[1], 10, 64); err == nil {
+					if suffixLen > totalSize {
+						suffixLen = totalSize
+					}
+					startOffset = totalSize - suffixLen
+					endOffset = totalSize - 1
+				} else {
+					w.WriteHeader(http.StatusRequestedRangeNotSatisfiable)
+					w.Header().Set("Content-Range", fmt.Sprintf("bytes */%d", totalSize))
+					return fmt.Errorf("invalid suffix range")
+				}
+			} else {
+				// Regular range or open-ended range
+				startOffset = 0
+				endOffset = totalSize - 1
 
 				if parts[0] != "" {
 					if parsed, err := strconv.ParseInt(parts[0], 10, 64); err == nil {
@@ -454,16 +476,23 @@ func (s3a *S3ApiServer) streamFromVolumeServers(w http.ResponseWriter, r *http.R
 				}
 
 				// Validate range
-			if startOffset < 0 || startOffset >= totalSize || endOffset < startOffset {
+				if startOffset < 0 || startOffset >= totalSize {
 					w.WriteHeader(http.StatusRequestedRangeNotSatisfiable)
 					w.Header().Set("Content-Range", fmt.Sprintf("bytes */%d", totalSize))
-				return fmt.Errorf("invalid range")
+					return fmt.Errorf("invalid range start")
 				}
 
 				if endOffset >= totalSize {
 					endOffset = totalSize - 1
 				}
 
+				if endOffset < startOffset {
+					w.WriteHeader(http.StatusRequestedRangeNotSatisfiable)
+					w.Header().Set("Content-Range", fmt.Sprintf("bytes */%d", totalSize))
+					return fmt.Errorf("invalid range: end before start")
+				}
+			}
+
 			offset = startOffset
 			size = endOffset - startOffset + 1
 			isRangeRequest = true