Expose UDP tracker error response type

diff --git a/tracker/udp/client.go b/tracker/udp/client.go
index d570b1a0ee0c4e007667e9ffc4349a9d6ca5024a..6b97ddcc098828bb56a30b85d7edab2af8f623f3 100644 (file)
--- a/tracker/udp/client.go
+++ b/tracker/udp/client.go
@@ -182,6 +182,16 @@ func (cl *Client) requestWriter(ctx context.Context, action Action, body []byte,
        }
 }
 
+const ConnectionIdMissmatchNul = "Connection ID missmatch.\x00"
+
+type ErrorResponse struct {
+       Message string
+}
+
+func (me ErrorResponse) Error() string {
+       return fmt.Sprintf("error response: %#q", me.Message)
+}
+
 func (cl *Client) request(ctx context.Context, action Action, body []byte) (respBody []byte, addr net.Addr, err error) {
        respChan := make(chan DispatchedResponse, 1)
        t := cl.Dispatcher.NewTransaction(func(dr DispatchedResponse) {
@@ -200,9 +210,9 @@ func (cl *Client) request(ctx context.Context, action Action, body []byte) (resp
                        respBody = dr.Body
                        addr = dr.Addr
                } else if dr.Header.Action == ActionError {
-                       // I've seen "Connection ID mismatch.^@" in less and other tools, I think they're just
-                       // not handling a trailing \x00 nicely.
-                       err = fmt.Errorf("error response: %#q", dr.Body)
+                       // udp://tracker.torrent.eu.org:451/announce frequently returns "Connection ID
+                       // missmatch.\x00"
+                       err = ErrorResponse{Message: string(dr.Body)}
                } else {
                        err = fmt.Errorf("unexpected response action %v", dr.Header.Action)
                }