Fix for Issue #40: file copies are aborted

xs/xs.go

@@ -1078,10 +1078,6 @@ func main() { //nolint: funlen, gocyclo
 		fmt.Fprintln(os.Stderr, rejectUserMsg())
 		rec.SetStatus(GeneralProtocolErr)
 	} else {
-		// === Set up connection keepalive to server
-		conn.StartupKeepAlive() // goroutine, returns immediately
-		defer conn.ShutdownKeepAlive()
-
 		// === Set up chaffing to server
 		conn.SetupChaff(chaffFreqMin, chaffFreqMax, chaffBytesMax) // enable client->server chaffing
 		if chaffEnabled {
@@ -1112,6 +1108,10 @@ func main() { //nolint: funlen, gocyclo
 
 		// === Session entry (shellMode or copyMode)
 		if shellMode {
+			// === Set up connection keepalive to server
+			conn.StartupKeepAlive() // goroutine, returns immediately
+			defer conn.ShutdownKeepAlive()
+
 			// === (shell) launch tunnels
 			launchTuns(&conn /*remoteHost,*/, tunSpecStr)
 			doShellMode(isInteractive, &conn, oldState, rec)

xsd/xsd.go

@@ -121,10 +121,6 @@ func runClientToServerCopyAs(who, ttype string, conn *xsnet.Conn, fpath string,
 	c.Stdout = os.Stdout
 	c.Stderr = os.Stderr
 
-	// === Set up connection keepalive to client
-	conn.StartupKeepAlive() // goroutine, returns immediately
-	defer conn.ShutdownKeepAlive()
-
 	if chaffing {
 		conn.StartupChaff()
 	}
@@ -221,10 +217,6 @@ func runServerToClientCopyAs(who, ttype string, conn *xsnet.Conn, srcPath string
 	c.Stderr = stdErrBuffer
 	//c.Stderr = nil
 
-	// === Set up connection keepalive to client
-	conn.StartupKeepAlive() // goroutine, returns immediately
-	defer conn.ShutdownKeepAlive()
-
 	if chaffing {
 		conn.StartupChaff()
 	}
@@ -380,11 +372,11 @@ func runShellAs(who, hname, ttype, cmd string, interactive bool, //nolint:funlen
 
 		if chaffing {
 			conn.StartupChaff()
+			// #gv:s/label=\"runShellAs\$4\"/label=\"deferChaffShutdown\"/
+				defer func() {
+				conn.ShutdownChaff()
+			}()
 		}
-		// #gv:s/label=\"runShellAs\$4\"/label=\"deferChaffShutdown\"/
-		defer func() {
-			conn.ShutdownChaff()
-		}()
 
 		// ..and the pty to stdout.
 		// This may take some time exceeding that of the