Tunnels w/reconnect refinements:

-200ms deadlink timeouts
-Fixed TunConnRefused client hangup handling

Signed-off-by: Russ Magee <rmagee@gmail.com>

hkexnet/hkexnet.go

@@ -842,6 +842,11 @@ func (hc Conn) Read(b []byte) (n int, err error) {
 				lport := binary.BigEndian.Uint16(payloadBytes[0:2])
 				rport := binary.BigEndian.Uint16(payloadBytes[2:4])
 				logger.LogDebug(fmt.Sprintf("[Client] Got CSOTunRefused [%d:%d]", lport, rport))
+				if _, ok := (*hc.tuns)[rport]; ok {
+					(*hc.tuns)[rport].Died = true
+				} else {
+					logger.LogDebug(fmt.Sprintf("[Client] CSOTunRefused on already-closed tun [%d:%d]", lport, rport))
+				}
 			} else if ctrlStatOp == CSOTunDisconn {
 				// server side's rport has disconnected (server lost)
 				lport := binary.BigEndian.Uint16(payloadBytes[0:2])

hkexnet/hkextun.go

@@ -52,7 +52,7 @@ type (
 )
 
 func (hc *Conn) CollapseAllTunnels(client bool) {
-	for k,t := range *hc.tuns {
+	for k, t := range *hc.tuns {
 		var tunDst bytes.Buffer
 		binary.Write(&tunDst, binary.BigEndian, t.Lport)
 		binary.Write(&tunDst, binary.BigEndian, t.Rport)
@@ -80,7 +80,7 @@ func (hc *Conn) InitTunEndpoint(lp uint16, p string /* net.Addr */, rp uint16) {
 			Ctl: make(chan rune, 1)}
 		logger.LogDebug(fmt.Sprintf("InitTunEndpoint [%d:%s:%d]", lp, p, rp))
 	} else {
-		logger.LogDebug(fmt.Sprintf("InitTunEndpoint [reusing] [%d:%s:%d]", (*hc.tuns)[rp].Lport, (*hc.tuns)[rp].Peer, (*hc.tuns)[rp].Rport))
+		logger.LogDebug(fmt.Sprintf("InitTunEndpoint [reusing] %v", (*hc.tuns)[rp]))
 		if (*hc.tuns)[rp].Data == nil {
 			// When re-using a tunnel it will have its
 			// data channel removed on closure. Re-create it
@@ -93,26 +93,26 @@ func (hc *Conn) InitTunEndpoint(lp uint16, p string /* net.Addr */, rp uint16) {
 
 func (hc *Conn) StartClientTunnel(lport, rport uint16) {
 	hc.InitTunEndpoint(lport, "", rport)
-	var l HKExListener
+
 	go func() {
 		var wg sync.WaitGroup
 		weAreListening := false
-		for cmd := range (*hc.tuns)[rport].Ctl {
-			logger.LogDebug(fmt.Sprintf("[ClientTun] Listening for client tunnel port %d", lport))
 
+		for cmd := range (*hc.tuns)[rport].Ctl {
 			if cmd == 'a' && !weAreListening {
 				l, e := net.Listen("tcp4", fmt.Sprintf(":%d", lport))
 				if e != nil {
 					logger.LogDebug(fmt.Sprintf("[ClientTun] Could not get lport %d! (%s)", lport, e))
 				} else {
 					weAreListening = true
+					logger.LogDebug(fmt.Sprintf("[ClientTun] Listening for client tunnel port %d", lport))
+
 					for {
+						c, e := l.Accept()
 						// If tunnel is being re-used, re-init it
 						if (*hc.tuns)[rport] == nil {
 							hc.InitTunEndpoint(lport, "", rport)
 						}
-						c, e := l.Accept()
-
 						// ask server to dial() its side, rport
 						var tunDst bytes.Buffer
 						binary.Write(&tunDst, binary.BigEndian, lport)
@@ -121,7 +121,6 @@ func (hc *Conn) StartClientTunnel(lport, rport uint16) {
 
 						if e != nil {
 							logger.LogDebug(fmt.Sprintf("[ClientTun] Accept() got error(%v), hanging up.", e))
-							//break
 						} else {
 							logger.LogDebug(fmt.Sprintf("[ClientTun] Accepted tunnel client %v", (*hc.tuns)[rport]))
 
@@ -145,7 +144,7 @@ func (hc *Conn) StartClientTunnel(lport, rport uint16) {
 								for {
 									rBuf := make([]byte, 1024)
 									//Read data from c, encrypt/write via hc to client(lport)
-									c.SetReadDeadline(time.Now().Add(20 * time.Second))
+									c.SetReadDeadline(time.Now().Add(200 * time.Millisecond))
 									n, e := c.Read(rBuf)
 									if e != nil {
 										if e == io.EOF {
@@ -211,7 +210,7 @@ func (hc *Conn) StartClientTunnel(lport, rport uint16) {
 								for {
 									bytes, ok := <-(*hc.tuns)[rport].Data
 									if ok {
-										c.SetWriteDeadline(time.Now().Add(20 * time.Second))
+										c.SetWriteDeadline(time.Now().Add(200 * time.Millisecond))
 										_, e := c.Write(bytes)
 										if e != nil {
 											logger.LogDebug(fmt.Sprintf("[ClientTun] worker B: lport conn closed"))
@@ -234,11 +233,6 @@ func (hc *Conn) StartClientTunnel(lport, rport uint16) {
 			} else if cmd == 'r' {
 				logger.LogDebug(fmt.Sprintf("[ClientTun] Server replied TunRefused %v\n", (*hc.tuns)[rport]))
 			}
-			_ = l //else if cmd == 'x' {
-			//logger.LogDebug(fmt.Sprintf("[ClientTun] Server replied TunDisconn, closing lport %v\n", t))
-			//l.Close()
-			//weAreListening = false
-			//}
 		} // end t.Ctl for
 	}()
 }
@@ -298,7 +292,7 @@ func (hc *Conn) StartServerTunnel(lport, rport uint16) {
 						for {
 							rBuf := make([]byte, 1024)
 							// Read data from c, encrypt/write via hc to client(lport)
-							c.SetReadDeadline(time.Now().Add(20 * time.Second))
+							c.SetReadDeadline(time.Now().Add(200 * time.Millisecond))
 							n, e := c.Read(rBuf)
 							if e != nil {
 								if e == io.EOF {
@@ -315,8 +309,6 @@ func (hc *Conn) StartServerTunnel(lport, rport uint16) {
 								} else if strings.Contains(e.Error(), "i/o timeout") {
 									if (*hc.tuns)[rport].Died {
 										logger.LogDebug(fmt.Sprintf("[ServerTun] worker A: timeout: Server side died, hanging up %v", (*hc.tuns)[rport]))
-										//hc.WritePacket(tunDst.Bytes(), CSOTunDisconn)
-										//(*hc.tuns)[rport].Died = true
 										if (*hc.tuns)[rport].Data != nil {
 											close((*hc.tuns)[rport].Data)
 											(*hc.tuns)[rport].Data = nil
@@ -360,7 +352,7 @@ func (hc *Conn) StartServerTunnel(lport, rport uint16) {
 						for {
 							rData, ok := <-(*hc.tuns)[rport].Data
 							if ok {
-								c.SetWriteDeadline(time.Now().Add(20 * time.Second))
+								c.SetWriteDeadline(time.Now().Add(200 * time.Millisecond))
 								_, e := c.Write(rData)
 								if e != nil {
 									logger.LogDebug(fmt.Sprintf("[ServerTun] worker B: ERROR writing to rport conn"))
@@ -379,6 +371,5 @@ func (hc *Conn) StartServerTunnel(lport, rport uint16) {
 			}
 		} // t.Ctl read loop
 		logger.LogDebug("[ServerTun] Tunnel exiting t.Ctl read loop - channel closed??")
-		//wg.Wait()
 	}()
 }

hkexsh/hkexsh.go

@@ -273,7 +273,6 @@ func doShellMode(isInteractive bool, conn *hkexnet.Conn, oldState *hkexsh.State,
 			// gracefully here
 			if !strings.HasSuffix(inerr.Error(), "use of closed network connection") {
 				log.Println(inerr)
-				conn.CollapseAllTunnels(true)
 				os.Exit(1)
 			}
 		}
@@ -311,7 +310,6 @@ func doShellMode(isInteractive bool, conn *hkexnet.Conn, oldState *hkexsh.State,
 				fmt.Println(outerr)
 				_ = hkexsh.Restore(int(os.Stdin.Fd()), oldState) // Best effort.
 				log.Println("[Hanging up]")
-				conn.CollapseAllTunnels(true)
 				os.Exit(0)
 			}
 		}()
@@ -648,7 +646,6 @@ func main() {
 			doShellMode(isInteractive, &conn, oldState, rec)
 		} else { // copyMode
 			_, s := doCopyMode(&conn, pathIsDest, fileArgs, rec)
-			conn.CollapseAllTunnels(true)
 			rec.SetStatus(s)
 		}