TUN-3799: extended the Stream interface to take a logger and added debug logs for io.Copy errors

carrier/websocket.go

@@ -62,7 +62,7 @@ func (ws *Websocket) ServeStream(options *StartOptions, conn io.ReadWriter) erro
 
 		_ = socksServer.Serve(conn)
 	} else {
-		ingress.Stream(wsConn, conn)
+		ingress.Stream(wsConn, conn, ws.log)
 	}
 	return nil
 }

ingress/origin_connection.go

@@ -8,30 +8,37 @@ import (
 	"github.com/cloudflare/cloudflared/connection"
 	"github.com/cloudflare/cloudflared/websocket"
 	gws "github.com/gorilla/websocket"
+	"github.com/rs/zerolog"
 )
 
 // OriginConnection is a way to stream to a service running on the user's origin.
 // Different concrete implementations will stream different protocols as long as they are io.ReadWriters.
 type OriginConnection interface {
 	// Stream should generally be implemented as a bidirectional io.Copy.
-	Stream(tunnelConn io.ReadWriter)
+	Stream(tunnelConn io.ReadWriter, log *zerolog.Logger)
 	Close()
 	Type() connection.Type
 }
 
-type streamHandlerFunc func(originConn io.ReadWriter, remoteConn net.Conn)
+type streamHandlerFunc func(originConn io.ReadWriter, remoteConn net.Conn, log *zerolog.Logger)
 
 // Stream copies copy data to & from provided io.ReadWriters.
-func Stream(conn, backendConn io.ReadWriter) {
+func Stream(conn, backendConn io.ReadWriter, log *zerolog.Logger) {
 	proxyDone := make(chan struct{}, 2)
 
 	go func() {
-		io.Copy(conn, backendConn)
+		_, err := io.Copy(conn, backendConn)
+		if err != nil {
+			log.Debug().Msgf("conn to backendConn copy: %v", err)
+		}
 		proxyDone <- struct{}{}
 	}()
 
 	go func() {
-		io.Copy(backendConn, conn)
+		_, err := io.Copy(backendConn, conn)
+		if err != nil {
+			log.Debug().Msgf("backendConn to conn copy: %v", err)
+		}
 		proxyDone <- struct{}{}
 	}()
 
@@ -41,8 +48,8 @@ func Stream(conn, backendConn io.ReadWriter) {
 
 // DefaultStreamHandler is an implementation of streamHandlerFunc that
 // performs a two way io.Copy between originConn and remoteConn.
-func DefaultStreamHandler(originConn io.ReadWriter, remoteConn net.Conn) {
-	Stream(originConn, remoteConn)
+func DefaultStreamHandler(originConn io.ReadWriter, remoteConn net.Conn, log *zerolog.Logger) {
+	Stream(originConn, remoteConn, log)
 }
 
 // tcpConnection is an OriginConnection that directly streams to raw TCP.
@@ -51,8 +58,8 @@ type tcpConnection struct {
 	streamHandler streamHandlerFunc
 }
 
-func (tc *tcpConnection) Stream(tunnelConn io.ReadWriter) {
-	tc.streamHandler(tunnelConn, tc.conn)
+func (tc *tcpConnection) Stream(tunnelConn io.ReadWriter, log *zerolog.Logger) {
+	tc.streamHandler(tunnelConn, tc.conn, log)
 }
 
 func (tc *tcpConnection) Close() {
@@ -70,8 +77,8 @@ type wsConnection struct {
 	resp   *http.Response
 }
 
-func (wsc *wsConnection) Stream(tunnelConn io.ReadWriter) {
-	Stream(tunnelConn, wsc.wsConn.UnderlyingConn())
+func (wsc *wsConnection) Stream(tunnelConn io.ReadWriter, log *zerolog.Logger) {
+	Stream(tunnelConn, wsc.wsConn.UnderlyingConn(), log)
 }
 
 func (wsc *wsConnection) Close() {

origin/proxy.go

@@ -202,7 +202,7 @@ func (p *proxy) proxyConnection(
 		originConn.Close()
 	}()
 
-	originConn.Stream(eyeballConn)
+	originConn.Stream(eyeballConn, p.log)
 	return resp, nil
 }
 

socks/request_handler.go

@@ -5,6 +5,8 @@ import (
 	"io"
 	"net"
 	"strings"
+
+	"github.com/rs/zerolog"
 )
 
 // RequestHandler is the functions needed to handle a SOCKS5 command
@@ -106,7 +108,7 @@ func (h *StandardRequestHandler) handleAssociate(conn io.ReadWriter, req *Reques
 	return nil
 }
 
-func StreamHandler(tunnelConn io.ReadWriter, originConn net.Conn) {
+func StreamHandler(tunnelConn io.ReadWriter, originConn net.Conn, log *zerolog.Logger) {
 	dialer := NewConnDialer(originConn)
 	requestHandler := NewRequestHandler(dialer)
 	socksServer := NewConnectionHandler(requestHandler)

websocket/websocket.go

@@ -54,7 +54,7 @@ func StartProxyServer(
 	listener net.Listener,
 	staticHost string,
 	shutdownC <-chan struct{},
-	streamHandler func(originConn io.ReadWriter, remoteConn net.Conn),
+	streamHandler func(originConn io.ReadWriter, remoteConn net.Conn, log *zerolog.Logger),
 ) error {
 	upgrader := websocket.Upgrader{
 		ReadBufferSize:  1024,
@@ -81,7 +81,7 @@ type handler struct {
 	log           *zerolog.Logger
 	staticHost    string
 	upgrader      websocket.Upgrader
-	streamHandler func(originConn io.ReadWriter, remoteConn net.Conn)
+	streamHandler func(originConn io.ReadWriter, remoteConn net.Conn, log *zerolog.Logger)
 }
 
 func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -118,7 +118,7 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	go gorillaConn.pinger(r.Context())
 	defer conn.Close()
 
-	h.streamHandler(gorillaConn, stream)
+	h.streamHandler(gorillaConn, stream, h.log)
 }
 
 // NewResponseHeader returns headers needed to return to origin for completing handshake