add support for data transfer bandwidth limits

with total limit or separate settings for uploads and downloads and
overrides based on the client's IP address.

Limits can be reset using the REST API

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

httpd/api_utils.go

@@ -97,6 +97,8 @@ func getMappedStatusCode(err error) int {
 	switch {
 	case errors.Is(err, os.ErrPermission):
 		statusCode = http.StatusForbidden
+	case errors.Is(err, common.ErrReadQuotaExceeded):
+		statusCode = http.StatusForbidden
 	case errors.Is(err, os.ErrNotExist):
 		statusCode = http.StatusNotFound
 	case errors.Is(err, common.ErrQuotaExceeded):
@@ -310,7 +312,11 @@ func downloadFile(w http.ResponseWriter, r *http.Request, connection *Connection
 	w.Header().Set("Accept-Ranges", "bytes")
 	w.WriteHeader(responseStatus)
 	if r.Method != http.MethodHead {
-		io.CopyN(w, reader, size) //nolint:errcheck
+		_, err = io.CopyN(w, reader, size)
+		if err != nil {
+			connection.Log(logger.LevelDebug, "error reading file to download: %v", err)
+			panic(http.ErrAbortHandler)
+		}
 	}
 	return http.StatusOK, nil
 }