ing

discovery/protocol/udp/connection/connection.go

@@ -30,6 +30,7 @@ func Scan(discoverySession session.DiscoverySession, targetHost *omd.Host) error
 
 	lock := semaphore.NewWeighted(Ulimit())
 	var wg sync.WaitGroup
+	stopChan := make(chan struct{})
 	timeout := 500 * time.Millisecond
 	ports := make(map[int]*omd.Port)
 
@@ -52,7 +53,7 @@ Loop:
 				wg.Done()
 			}()
 
-			tryConnect(discoverySession, ports, targetHost, port, timeout)
+			tryConnect(discoverySession, ports, targetHost, port, timeout, stopChan)
 		}(portNumber)
 
 		timer := time.NewTimer(time.Microsecond * 100)
@@ -60,6 +61,7 @@ Loop:
 		select {
 		case <-timer.C:
 		case <-discoverySession.StopChan():
+			close(stopChan)
 			return nil
 		}
 	}
@@ -69,7 +71,7 @@ Loop:
 	return nil
 }
 
-func tryConnect(discoverySession session.DiscoverySession, ports map[int]*omd.Port, targetHost *omd.Host, port int, timeout time.Duration) {
+func tryConnect(discoverySession session.DiscoverySession, ports map[int]*omd.Port, targetHost *omd.Host, port int, timeout time.Duration, stopChan <-chan struct{}) {
 	addr := net.JoinHostPort(targetHost.Address, strconv.Itoa(port))
 	conn, err := net.DialTimeout("tcp", addr, timeout)
 	dp := discoverySession.DiscoverPort()
@@ -77,12 +79,12 @@ func tryConnect(discoverySession session.DiscoverySession, ports map[int]*omd.Po
 	if err != nil {
 		if strings.Contains(err.Error(), "too many open files") {
 			select {
-			case <-discoverySession.StopChan():
+			case <-stopChan:
 				return
 			default:
 			}
 			time.Sleep(timeout)
-			tryConnect(discoverySession, ports, targetHost, port, timeout)
+			tryConnect(discoverySession, ports, targetHost, port, timeout, stopChan)
 		}
 		return
 	}