make transport level methods optional

core/network/conn.go

@@ -15,6 +15,7 @@ import (
 type ConnErrorCode uint32
 
 type ConnError struct {
+	Remote    bool
 	ErrorCode uint32
 }
 
@@ -30,15 +31,16 @@ func (c *ConnError) Error() string {
 type Conn interface {
 	io.Closer
 
-	// CloseWithError closes the connection with errCode. The errCode is sent
-	// to the peer.
-	CloseWithError(errCode ConnErrorCode) error
-
 	ConnSecurity
 	ConnMultiaddrs
 	ConnStat
 	ConnScoper
 
+	// CloseWithError closes the connection with errCode. The errCode is sent to the
+	// peer on a best effort basis. For transports that do not support sending error
+	// codes on connection close, the behavior is identical to calling Close.
+	CloseWithError(errCode ConnErrorCode) error
+
 	// ID returns an identifier that uniquely identifies this Conn within this
 	// host, during this run. Connection IDs may repeat across restarts.
 	ID() string

core/network/mux.go

@@ -72,15 +72,18 @@ type MuxedStream interface {
 	// side to hang up and go away.
 	Reset() error
 
-	// ResetWithError closes both ends of the stream with errCode. The errCode is sent
-	// to the peer.
-	ResetWithError(errCode StreamErrorCode) error
-
 	SetDeadline(time.Time) error
 	SetReadDeadline(time.Time) error
 	SetWriteDeadline(time.Time) error
 }
 
+type ResetWithErrorer interface {
+	// ResetWithError closes both ends of the stream with errCode. The errCode is sent
+	// to the peer on a best effort basis. For transports that do not support sending
+	// error codes to remote peer, the behavior is identical to calling Reset
+	ResetWithError(errCode StreamErrorCode) error
+}
+
 // MuxedConn represents a connection to a remote peer that has been
 // extended to support stream multiplexing.
 //
@@ -95,10 +98,6 @@ type MuxedConn interface {
 	// Close closes the stream muxer and the the underlying net.Conn.
 	io.Closer
 
-	// CloseWithError closes the connection with errCode. The errCode is sent
-	// to the peer.
-	CloseWithError(errCode ConnErrorCode) error
-
 	// IsClosed returns whether a connection is fully closed, so it can
 	// be garbage collected.
 	IsClosed() bool
@@ -110,6 +109,12 @@ type MuxedConn interface {
 	AcceptStream() (MuxedStream, error)
 }
 
+type ConnWithErrorer interface {
+	// CloseWithError closes the connection with errCode. The errCode is sent
+	// to the peer.
+	ConnWithError(errCode ConnErrorCode) error
+}
+
 // Multiplexer wraps a net.Conn with a stream multiplexing
 // implementation and returns a MuxedConn that supports opening
 // multiple streams over the underlying net.Conn

core/network/stream.go

@@ -27,4 +27,8 @@ type Stream interface {
 
 	// Scope returns the user's view of this stream's resource scope
 	Scope() StreamScope
+
+	// ResetWithError closes both ends of the stream with errCode. The errCode is sent
+	// to the peer.
+	ResetWithError(errCode StreamErrorCode) error
 }

p2p/net/mock/mock_conn.go

@@ -86,10 +86,6 @@ func (c *conn) Close() error {
 	return nil
 }
 
-func (c *conn) CloseWithError(errCode network.ConnErrorCode) error {
-	panic("not implemented")
-}
-
 func (c *conn) teardown() {
 	for _, s := range c.allStreams() {
 		s.Reset()

p2p/net/swarm/swarm_conn.go

@@ -80,7 +80,17 @@ func (c *Conn) doClose(errCode network.ConnErrorCode) {
 	c.streams.m = nil
 	c.streams.Unlock()
 
-	c.err = c.conn.CloseWithError(errCode)
+	if errCode != 0 {
+		if ce, ok := c.conn.(interface {
+			CloseWithError(network.ConnErrorCode) error
+		}); ok {
+			c.err = ce.CloseWithError(errCode)
+		} else {
+			c.err = c.conn.Close()
+		}
+	} else {
+		c.err = c.conn.Close()
+	}
 
 	// Send the connectedness event after closing the connection.
 	// This ensures that both remote connection close and local connection

p2p/net/swarm/swarm_stream.go

@@ -92,7 +92,12 @@ func (s *Stream) Reset() error {
 }
 
 func (s *Stream) ResetWithError(errCode network.StreamErrorCode) error {
-	err := s.stream.ResetWithError(errCode)
+	var err error
+	if se, ok := s.stream.(network.ResetWithErrorer); ok {
+		err = se.ResetWithError(errCode)
+	} else {
+		err = s.stream.Reset()
+	}
 	s.closeAndRemoveStream()
 	return err
 }