Fix the problematic SSH handshake timeout

application/commands/ssh.go

@@ -109,27 +109,7 @@ var (
 type sshRemoteConnWrapper struct {
 	net.Conn
 
-	readTimeout   time.Duration
-	enableTimeout bool
-	retryTimeout  func() bool
-}
-
-func (s *sshRemoteConnWrapper) SetReadDeadline(t time.Time) error {
-	s.enableTimeout = false
-
-	return s.Conn.SetReadDeadline(t)
-}
-
-func (s *sshRemoteConnWrapper) SetWriteDeadline(t time.Time) error {
-	s.enableTimeout = false
-
-	return s.Conn.SetWriteDeadline(t)
-}
-
-func (s *sshRemoteConnWrapper) SetDeadline(t time.Time) error {
-	s.enableTimeout = false
-
-	return s.Conn.SetDeadline(t)
+	requestTimeoutRetry func(s *sshRemoteConnWrapper) bool
 }
 
 func (s *sshRemoteConnWrapper) Read(b []byte) (int, error) {
@@ -139,18 +119,12 @@ func (s *sshRemoteConnWrapper) Read(b []byte) (int, error) {
 		return rLen, nil
 	}
 
-	if !s.enableTimeout {
-		return rLen, rErr
-	}
-
 	netErr, isNetErr := rErr.(net.Error)
 
-	if !isNetErr || !netErr.Timeout() {
+	if !isNetErr || !netErr.Timeout() || !s.requestTimeoutRetry(s) {
 		return rLen, rErr
 	}
 
-	s.Conn.SetReadDeadline(time.Now().Add(s.readTimeout))
-
 	for {
 		rLen, rErr := s.Conn.Read(b)
 
@@ -158,17 +132,11 @@ func (s *sshRemoteConnWrapper) Read(b []byte) (int, error) {
 			return rLen, nil
 		}
 
-		if !s.enableTimeout {
-			return rLen, rErr
-		}
-
 		netErr, isNetErr := rErr.(net.Error)
 
-		if !isNetErr || !netErr.Timeout() || !s.retryTimeout() {
+		if !isNetErr || !netErr.Timeout() || !s.requestTimeoutRetry(s) {
 			return rLen, rErr
 		}
-
-		s.Conn.SetReadDeadline(time.Now().Add(s.readTimeout))
 	}
 }
 
@@ -188,6 +156,7 @@ type sshClient struct {
 	cfg                                  command.Configuration
 	remoteCloseWait                      sync.WaitGroup
 	remoteReadTimeoutRetry               bool
+	remoteReadForceRetryNextTimeout      bool
 	remoteReadTimeoutRetryLock           sync.Mutex
 	credentialReceive                    chan []byte
 	credentialProcessed                  bool
@@ -210,6 +179,7 @@ func newSSH(
 		cfg:                                  cfg,
 		remoteCloseWait:                      sync.WaitGroup{},
 		remoteReadTimeoutRetry:               false,
+		remoteReadForceRetryNextTimeout:      false,
 		remoteReadTimeoutRetryLock:           sync.Mutex{},
 		credentialReceive:                    make(chan []byte, 1),
 		credentialProcessed:                  false,
@@ -390,6 +360,7 @@ func (d *sshClient) disableRemoteReadTimeoutRetry() {
 	defer d.remoteReadTimeoutRetryLock.Unlock()
 
 	d.remoteReadTimeoutRetry = false
+	d.remoteReadForceRetryNextTimeout = true
 }
 
 func (d *sshClient) dialRemote(
@@ -402,21 +373,29 @@ func (d *sshClient) dialRemote(
 		return nil, nil, err
 	}
 
-	conn.SetReadDeadline(time.Now().Add(config.Timeout))
-
-	sshConn := sshRemoteConnWrapper{
-		Conn:          conn,
-		readTimeout:   config.Timeout,
-		enableTimeout: true,
-		retryTimeout: func() bool {
+	sshConn := &sshRemoteConnWrapper{
+		Conn: conn,
+		requestTimeoutRetry: func(s *sshRemoteConnWrapper) bool {
 			d.remoteReadTimeoutRetryLock.Lock()
 			defer d.remoteReadTimeoutRetryLock.Unlock()
 
-			return d.remoteReadTimeoutRetry
+			if !d.remoteReadTimeoutRetry {
+				if !d.remoteReadForceRetryNextTimeout {
+					return false
+				}
+
+				d.remoteReadForceRetryNextTimeout = false
+			}
+
+			s.SetReadDeadline(time.Now().Add(config.Timeout))
+
+			return true
 		},
 	}
 
-	c, chans, reqs, err := ssh.NewClientConn(&sshConn, addr, config)
+	sshConn.SetReadDeadline(time.Now().Add(config.Timeout))
+
+	c, chans, reqs, err := ssh.NewClientConn(sshConn, addr, config)
 
 	if err != nil {
 		sshConn.Close()
@@ -425,11 +404,13 @@ func (d *sshClient) dialRemote(
 	}
 
 	return ssh.NewClient(c, chans, reqs), func() {
-		if sshConn.enableTimeout {
-			sshConn.SetReadDeadline(sshEmptyTime)
-		}
+		d.remoteReadTimeoutRetryLock.Lock()
+		defer d.remoteReadTimeoutRetryLock.Unlock()
 
-		sshConn.enableTimeout = false
+		d.remoteReadTimeoutRetry = false
+		d.remoteReadForceRetryNextTimeout = true
+
+		sshConn.SetReadDeadline(sshEmptyTime)
 	}, nil
 }