From 552d16bce22bc575d129343d7d44661ab02c9aac Mon Sep 17 00:00:00 2001
From: John Maguire <john@defined.net>
Date: Mon, 31 Oct 2022 14:49:38 -0400
Subject: [PATCH] Improvements to NebulaVpnService (#79)

---
 .../net/defined/mobile_nebula/MainActivity.kt | 11 ++-----
 .../defined/mobile_nebula/NebulaVpnService.kt | 30 +++++++++++++------
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/android/app/src/main/kotlin/net/defined/mobile_nebula/MainActivity.kt b/android/app/src/main/kotlin/net/defined/mobile_nebula/MainActivity.kt
index 3597041..2738c4b 100644
--- a/android/app/src/main/kotlin/net/defined/mobile_nebula/MainActivity.kt
+++ b/android/app/src/main/kotlin/net/defined/mobile_nebula/MainActivity.kt
@@ -195,16 +195,11 @@ class MainActivity: FlutterActivity() {
 
     private fun stopSite() {
         val intent = Intent(this, NebulaVpnService::class.java)
-        intent.putExtra("COMMAND", "STOP")
+        intent.setAction(NebulaVpnService.ACTION_STOP)
 
-        //This is odd but stopService goes nowhere in my tests and this is correct
-        // according to the official example https://android.googlesource.com/platform/development/+/master/samples/ToyVpn/src/com/example/android/toyvpn/ToyVpnClient.java#116
+        // We can't stopService because we have to close the fd first. The service will call stopSelf when ready.
+        // See the official example: https://android.googlesource.com/platform/development/+/master/samples/ToyVpn/src/com/example/android/toyvpn/ToyVpnClient.java#116
         startService(intent)
-        //TODO: why doesn't this work!?!?
-//        if (serviceIntent != null) {
-//            Log.e(TAG, "stopping ${serviceIntent.toString()}")
-//            stopService(serviceIntent)
-//        }
     }
 
     private fun activeListHostmap(call: MethodCall, result: MethodChannel.Result) {
diff --git a/android/app/src/main/kotlin/net/defined/mobile_nebula/NebulaVpnService.kt b/android/app/src/main/kotlin/net/defined/mobile_nebula/NebulaVpnService.kt
index 3b06673..da64c14 100644
--- a/android/app/src/main/kotlin/net/defined/mobile_nebula/NebulaVpnService.kt
+++ b/android/app/src/main/kotlin/net/defined/mobile_nebula/NebulaVpnService.kt
@@ -18,6 +18,7 @@ class NebulaVpnService : VpnService() {
 
     companion object {
         private const val TAG = "NebulaVpnService"
+        const val ACTION_STOP = "net.defined.mobile_nebula.STOP"
         const val MSG_REGISTER_CLIENT = 1
         const val MSG_UNREGISTER_CLIENT = 2
         const val MSG_IS_RUNNING = 3
@@ -40,10 +41,10 @@ class NebulaVpnService : VpnService() {
     private var nebula: mobileNebula.Nebula? = null
     private var vpnInterface: ParcelFileDescriptor? = null
     private var didSleep = false
-    private var networkCallback: NetworkCallback = NetworkCallback();
+    private var networkCallback: NetworkCallback = NetworkCallback()
 
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        if (intent?.getStringExtra("COMMAND") == "STOP") {
+        if (intent?.getAction() == ACTION_STOP) {
             stopVpn()
             return Service.START_NOT_STICKY
         }
@@ -103,7 +104,7 @@ class NebulaVpnService : VpnService() {
 
         try {
             vpnInterface = builder.establish()
-            nebula = mobileNebula.MobileNebula.newNebula(site!!.config, site!!.getKey(this), site!!.logFile, vpnInterface!!.fd.toLong())
+            nebula = mobileNebula.MobileNebula.newNebula(site!!.config, site!!.getKey(this), site!!.logFile, vpnInterface!!.detachFd().toLong())
 
         } catch (e: Exception) {
             Log.e(TAG, "Got an error $e")
@@ -115,7 +116,7 @@ class NebulaVpnService : VpnService() {
         registerNetworkCallback()
         //TODO: There is an open discussion around sleep killing tunnels or just changing mobile to tear down stale tunnels
         //registerSleep()
-        
+
         nebula!!.start()
         running = true
         sendSimple(MSG_IS_RUNNING, if (running) 1 else 0)
@@ -170,14 +171,25 @@ class NebulaVpnService : VpnService() {
     }
 
     private fun stopVpn() {
+        if (nebula == null) {
+            return stopSelf()
+        }
+
         unregisterNetworkCallback()
         nebula?.stop()
-        vpnInterface?.close()
+        nebula = null
         running = false
         announceExit(site?.id, null)
+        stopSelf()
     }
 
-    override fun onDestroy()  {
+    override fun onRevoke()  {
+        stopVpn()
+        //TODO: wait for the thread to exit
+        super.onRevoke()
+    }
+
+    override fun onDestroy() {
         stopVpn()
         //TODO: wait for the thread to exit
         super.onDestroy()
@@ -240,7 +252,7 @@ class NebulaVpnService : VpnService() {
             m.data.putString("data", res)
             msg.replyTo.send(m)
         }
-        
+
         private fun getHostInfo(msg: Message) {
             if (protect(msg)) { return }
 
@@ -258,7 +270,7 @@ class NebulaVpnService : VpnService() {
             m.data.putString("data", res)
             msg.replyTo.send(m)
         }
-        
+
         private fun closeTunnel(msg: Message) {
             if (protect(msg)) { return }
 
@@ -300,4 +312,4 @@ class NebulaVpnService : VpnService() {
         messenger = Messenger(IncomingHandler(this))
         return messenger.binder
     }
-}
\ No newline at end of file
+}