Moved server keepalive ageing for tunnels to goroutine -- fix for premature tunnel collapses

hkexnet/hkexnet.go

@@ -77,6 +77,7 @@ type (
 
 		logCipherText  bool // somewhat expensive, for debugging
 		logPlainText   bool // INSECURE and somewhat expensive, for debugging
+		logTunActivity bool
 
 		cipheropts uint32 // post-KEx cipher/hmac options
 		opts       uint32 // post-KEx protocol options (caller-defined)
@@ -1112,8 +1113,11 @@ func (hc Conn) Read(b []byte) (n int, err error) {
 				rport := binary.BigEndian.Uint16(payloadBytes[2:4])
 				//fmt.Printf("[Got CSOTunData: [lport %d:rport %d] data:%v\n", lport, rport, payloadBytes[4:])
 				if _, ok := (*hc.tuns)[rport]; ok {
+					if hc.logTunActivity {
 						logger.LogDebug(fmt.Sprintf("[Writing data to rport [%d:%d]", lport, rport))
+					}
 					(*hc.tuns)[rport].Data <- payloadBytes[4:]
+					(*hc.tuns)[rport].KeepAlive = 0
 				} else {
 					logger.LogDebug(fmt.Sprintf("[Attempt to write data to closed tun [%d:%d]", lport, rport))
 				}

hkexnet/hkextun.go

@@ -244,6 +244,24 @@ func (hc *Conn) StartServerTunnel(lport, rport uint16) {
 	go func() {
 		var wg sync.WaitGroup
 
+		//
+		// worker to age server tunnel and kill it if keepalives
+		// stop from client
+		//
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				time.Sleep(100 * time.Millisecond)
+				(*hc.tuns)[rport].KeepAlive += 1
+				if (*hc.tuns)[rport].KeepAlive > 25 {
+					(*hc.tuns)[rport].Died = true
+					logger.LogDebug("[ServerTun] worker A: Client died, hanging up.")
+					break
+				}
+			}
+		}()
+
 		for cmd := range (*hc.tuns)[rport].Ctl {
 			var c net.Conn
 			logger.LogDebug(fmt.Sprintf("[ServerTun] got Ctl '%c'.", cmd))
@@ -330,12 +348,12 @@ func (hc *Conn) StartServerTunnel(lport, rport uint16) {
 								hc.WritePacket(rBuf[:n+4], CSOTunData)
 							}
 
-							if (*hc.tuns)[rport].KeepAlive > 50 {
-								(*hc.tuns)[rport].Died = true
-								logger.LogDebug("[ServerTun] worker A: Client died, hanging up.")
-							} else {
-								(*hc.tuns)[rport].KeepAlive += 1
-							}
+							//if (*hc.tuns)[rport].KeepAlive > 50000 {
+							//	(*hc.tuns)[rport].Died = true
+							//	logger.LogDebug("[ServerTun] worker A: Client died, hanging up.")
+							//} else {
+							//	(*hc.tuns)[rport].KeepAlive += 1
+							//}
 
 						}
 						logger.LogDebug("[ServerTun] worker A: exiting")