manager: clean stale adapters on startup

Signed-off-by: Simon Rozman <simon@rozman.si>

2 files changed, 70 insertions, 0 deletions

diff --git a/manager/adapters.go b/manager/adapters.go
new file mode 100644
index 00000000..5ac16465
--- /dev/null
+++ b/manager/adapters.go
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package manager
+
+import (
+	"log"
+
+	"golang.org/x/sys/windows"
+	"golang.org/x/sys/windows/svc"
+	"golang.org/x/sys/windows/svc/mgr"
+
+	"golang.zx2c4.com/wireguard/tun/wintun"
+	"golang.zx2c4.com/wireguard/windows/services"
+)
+
+func cleanStaleAdapters() {
+	defer printPanic()
+
+	m, err := mgr.Connect()
+	if err != nil {
+		log.Printf("Error connecting to Service Control Manager: %v", err)
+		return
+	}
+	defer m.Disconnect()
+
+	wintun.DeleteMatchingInterfaces(func(wintun *wintun.Wintun) bool {
+		interfaceName, err := wintun.InterfaceName()
+		if err != nil {
+			log.Printf("Removing Wintun interface %s because determining interface name failed: %v", wintun.GUID().String(), err)
+			return true
+		}
+		serviceName, err := services.ServiceNameOfTunnel(interfaceName)
+		if err != nil {
+			log.Printf("Removing Wintun interface %s because determining tunnel service name failed: %v", interfaceName, err)
+			return true
+		}
+		service, err := m.OpenService(serviceName)
+		if err == windows.ERROR_SERVICE_DOES_NOT_EXIST {
+			log.Printf("Removing orphaned Wintun interface %s", interfaceName)
+			return true
+		}
+		if err != nil {
+			log.Printf("Error opening service %s: %v", serviceName, err)
+			return false
+		}
+		defer service.Close()
+		config, err := service.Config()
+		if err != nil {
+			log.Printf("Error getting service %s configuration: %v", serviceName, err)
+			return false
+		}
+		if config.StartType == mgr.StartAutomatic {
+			return false
+		}
+		status, err := service.Query()
+		if err != nil {
+			log.Printf("Error getting service %s status: %v", serviceName, err)
+			return false
+		}
+		if status.State == svc.Stopped {
+			log.Printf("Removing unused Wintun interface %s", interfaceName)
+			return true
+		}
+		return false
+	})
+}
diff --git a/manager/service.go b/manager/service.go
index 3b71bbff..7ab3db16 100644
--- a/manager/service.go
+++ b/manager/service.go
@@ -247,6 +247,7 @@ func (service *managerService) Execute(args []string, r <-chan svc.ChangeRequest
 		}()
 	}
 
+	go cleanStaleAdapters()
 	go checkForUpdates()
 
 	var sessionsPointer *windows.WTS_SESSION_INFO