From a0d32a2d13f86ab87c34245c957e192658a45fc0 Mon Sep 17 00:00:00 2001
From: Tobias Brunner <tobias@strongswan.org>
Date: Fri, 8 May 2020 12:17:52 +0200
Subject: [PATCH] android: Ask user to add our app to the device's power
 whitelist

This is necessary so we can actually schedule events accurately in Doze
mode. Otherwise, we'd only get woken in intervals of several minutes (up to
15 according to the docs) after about an hour.
---
 .../android/app/src/main/AndroidManifest.xml  |  3 +-
 .../android/ui/VpnProfileControlActivity.java | 74 +++++++++++++++++--
 .../app/src/main/res/values-de/strings.xml    |  2 +
 .../app/src/main/res/values-pl/strings.xml    |  2 +
 .../app/src/main/res/values-ru/strings.xml    |  2 +
 .../app/src/main/res/values-ua/strings.xml    |  2 +
 .../src/main/res/values-zh-rCN/strings.xml    |  2 +
 .../src/main/res/values-zh-rTW/strings.xml    |  2 +
 .../app/src/main/res/values/strings.xml       |  2 +
 9 files changed, 85 insertions(+), 6 deletions(-)

diff --git a/src/frontends/android/app/src/main/AndroidManifest.xml b/src/frontends/android/app/src/main/AndroidManifest.xml
index 2b2ddfcdd..6c61e06f1 100644
--- a/src/frontends/android/app/src/main/AndroidManifest.xml
+++ b/src/frontends/android/app/src/main/AndroidManifest.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
-    Copyright (C) 2012-2018 Tobias Brunner
+    Copyright (C) 2012-2020 Tobias Brunner
     Copyright (C) 2012 Giuliano Grassi
     Copyright (C) 2012 Ralf Sager
     HSR Hochschule fuer Technik Rapperswil
@@ -22,6 +22,7 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
 
     <application
         android:name=".logic.StrongSwanApplication"
diff --git a/src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileControlActivity.java b/src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileControlActivity.java
index 813afbb94..896c9de94 100644
--- a/src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileControlActivity.java
+++ b/src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileControlActivity.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012-2018 Tobias Brunner
+ * Copyright (C) 2012-2020 Tobias Brunner
  * HSR Hochschule fuer Technik Rapperswil
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -19,12 +19,17 @@ import android.app.Dialog;
 import android.app.Service;
 import android.content.ActivityNotFoundException;
 import android.content.ComponentName;
+import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.ServiceConnection;
+import android.net.Uri;
 import android.net.VpnService;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.IBinder;
+import android.os.PowerManager;
+import android.provider.Settings;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.EditText;
@@ -37,6 +42,7 @@ import org.strongswan.android.data.VpnType.VpnTypeFeature;
 import org.strongswan.android.logic.VpnStateService;
 import org.strongswan.android.logic.VpnStateService.State;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.app.AppCompatDialogFragment;
@@ -51,6 +57,7 @@ public class VpnProfileControlActivity extends AppCompatActivity
 	public static final String EXTRA_VPN_PROFILE_ID = "org.strongswan.android.VPN_PROFILE_ID";
 
 	private static final int PREPARE_VPN_SERVICE = 0;
+	private static final int ADD_TO_POWER_WHITELIST = 1;
 	private static final String WAITING_FOR_RESULT = "WAITING_FOR_RESULT";
 	private static final String PROFILE_NAME = "PROFILE_NAME";
 	private static final String PROFILE_REQUIRES_PASSWORD = "REQUIRES_PASSWORD";
@@ -181,6 +188,27 @@ public class VpnProfileControlActivity extends AppCompatActivity
 		}
 	}
 
+	/**
+	 * Check if we are on the system's power whitelist, if necessary, or ask the user
+	 * to add us.
+	 * @return true if profile can be initiated immediately
+	 */
+	private boolean checkPowerWhitelist()
+	{
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
+		{
+			PowerManager pm = (PowerManager)this.getSystemService(Context.POWER_SERVICE);
+			if (!pm.isIgnoringBatteryOptimizations(this.getPackageName()))
+			{
+				PowerWhitelistRequired whitelist = new PowerWhitelistRequired();
+				mWaitingForResult = true;
+				whitelist.show(getSupportFragmentManager(), DIALOG_TAG);
+				return false;
+			}
+		}
+		return true;
+	}
+
 	@Override
 	protected void onActivityResult(int requestCode, int resultCode, Intent data)
 	{
@@ -190,11 +218,14 @@ public class VpnProfileControlActivity extends AppCompatActivity
 				mWaitingForResult = false;
 				if (resultCode == RESULT_OK && mProfileInfo != null)
 				{
-					if (mService != null)
+					if (checkPowerWhitelist())
 					{
-						mService.connect(mProfileInfo, true);
+						if (mService != null)
+						{
+							mService.connect(mProfileInfo, true);
+						}
+						finish();
 					}
-					finish();
 				}
 				else
 				{	/* this happens if the always-on VPN feature is activated by a different app or the user declined */
@@ -207,6 +238,14 @@ public class VpnProfileControlActivity extends AppCompatActivity
 					VpnNotSupportedError.showWithMessage(this, R.string.vpn_not_supported_no_permission);
 				}
 				break;
+			case ADD_TO_POWER_WHITELIST:
+				mWaitingForResult = false;
+				if (mProfileInfo != null && mService != null)
+				{
+					mService.connect(mProfileInfo, true);
+				}
+				finish();
+				break;
 			default:
 				super.onActivityResult(requestCode, resultCode, data);
 		}
@@ -531,6 +570,32 @@ public class VpnProfileControlActivity extends AppCompatActivity
 		}
 	}
 
+	/**
+	 * Class that displays a warning before asking the user to add the app to the
+	 * device's power whitelist.
+	 */
+	public static class PowerWhitelistRequired extends AppCompatDialogFragment
+	{
+		@Override
+		public Dialog onCreateDialog(Bundle savedInstanceState)
+		{
+			return new AlertDialog.Builder(getActivity())
+				.setTitle(R.string.power_whitelist_title)
+				.setMessage(R.string.power_whitelist_text)
+				.setPositiveButton(android.R.string.ok, (dialog, id) -> {
+					Intent intent = new Intent(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS,
+											   Uri.parse("package:" + getActivity().getPackageName()));
+					getActivity().startActivityForResult(intent, ADD_TO_POWER_WHITELIST);
+				}).create();
+		}
+
+		@Override
+		public void onCancel(@NonNull DialogInterface dialog)
+		{
+			getActivity().finish();
+		}
+	}
+
 	/**
 	 * Class representing an error message which is displayed if VpnService is
 	 * not supported on the current device.
@@ -556,7 +621,6 @@ public class VpnProfileControlActivity extends AppCompatActivity
 			return new AlertDialog.Builder(getActivity())
 				.setTitle(R.string.vpn_not_supported_title)
 				.setMessage(messageId)
-				.setCancelable(false)
 				.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener()
 				{
 					@Override
diff --git a/src/frontends/android/app/src/main/res/values-de/strings.xml b/src/frontends/android/app/src/main/res/values-de/strings.xml
index fcd14ea24..76652bc63 100644
--- a/src/frontends/android/app/src/main/res/values-de/strings.xml
+++ b/src/frontends/android/app/src/main/res/values-de/strings.xml
@@ -215,6 +215,8 @@
         <item quantity="other">Wiederholen in %1$d Sekunden</item>
     </plurals>
     <string name="cancel_retry">Wiederholen abbrechen</string>
+    <string name="power_whitelist_title">Akku-Optimierung deaktivieren</string>
+    <string name="power_whitelist_text">Bitte den nächsten Dialog bestätigen, um die App auf die weisse Liste für Akku-Optimierung zu setzen, so dass sie NAT keepalives und Rekeyings zeitlich korrekt planen kann, um konstant erreichbar zu bleiben während die VPN-Verbindung besteht.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">VPN umschalten</string>
diff --git a/src/frontends/android/app/src/main/res/values-pl/strings.xml b/src/frontends/android/app/src/main/res/values-pl/strings.xml
index 6f4716ba8..2e1df077e 100644
--- a/src/frontends/android/app/src/main/res/values-pl/strings.xml
+++ b/src/frontends/android/app/src/main/res/values-pl/strings.xml
@@ -215,6 +215,8 @@
         <item quantity="other">Retry in %1$d seconds</item>
     </plurals>
     <string name="cancel_retry">Cancel retry</string>
+    <string name="power_whitelist_title">Disable battery optimizations</string>
+    <string name="power_whitelist_text">Please confirm the next dialog to add the app to the device\'s power whitelist so it can ignore battery optimizations and schedule NAT keep-alives and rekeyings accurately in order to constantly keep reachable while the VPN is established.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">Toggle VPN</string>
diff --git a/src/frontends/android/app/src/main/res/values-ru/strings.xml b/src/frontends/android/app/src/main/res/values-ru/strings.xml
index 5def66df8..23fa95d38 100644
--- a/src/frontends/android/app/src/main/res/values-ru/strings.xml
+++ b/src/frontends/android/app/src/main/res/values-ru/strings.xml
@@ -212,6 +212,8 @@
         <item quantity="other">Retry in %1$d seconds</item>
     </plurals>
     <string name="cancel_retry">Cancel retry</string>
+    <string name="power_whitelist_title">Disable battery optimizations</string>
+    <string name="power_whitelist_text">Please confirm the next dialog to add the app to the device\'s power whitelist so it can ignore battery optimizations and schedule NAT keep-alives and rekeyings accurately in order to constantly keep reachable while the VPN is established.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">Toggle VPN</string>
diff --git a/src/frontends/android/app/src/main/res/values-ua/strings.xml b/src/frontends/android/app/src/main/res/values-ua/strings.xml
index 4920aa238..b4937364e 100644
--- a/src/frontends/android/app/src/main/res/values-ua/strings.xml
+++ b/src/frontends/android/app/src/main/res/values-ua/strings.xml
@@ -213,6 +213,8 @@
         <item quantity="other">Retry in %1$d seconds</item>
     </plurals>
     <string name="cancel_retry">Cancel retry</string>
+    <string name="power_whitelist_title">Disable battery optimizations</string>
+    <string name="power_whitelist_text">Please confirm the next dialog to add the app to the device\'s power whitelist so it can ignore battery optimizations and schedule NAT keep-alives and rekeyings accurately in order to constantly keep reachable while the VPN is established.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">Toggle VPN</string>
diff --git a/src/frontends/android/app/src/main/res/values-zh-rCN/strings.xml b/src/frontends/android/app/src/main/res/values-zh-rCN/strings.xml
index 3408f5f55..c1dbefb66 100644
--- a/src/frontends/android/app/src/main/res/values-zh-rCN/strings.xml
+++ b/src/frontends/android/app/src/main/res/values-zh-rCN/strings.xml
@@ -212,6 +212,8 @@
         <item quantity="other">Retry in %1$d seconds</item>
     </plurals>
     <string name="cancel_retry">Cancel retry</string>
+    <string name="power_whitelist_title">Disable battery optimizations</string>
+    <string name="power_whitelist_text">Please confirm the next dialog to add the app to the device\'s power whitelist so it can ignore battery optimizations and schedule NAT keep-alives and rekeyings accurately in order to constantly keep reachable while the VPN is established.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">Toggle VPN</string>
diff --git a/src/frontends/android/app/src/main/res/values-zh-rTW/strings.xml b/src/frontends/android/app/src/main/res/values-zh-rTW/strings.xml
index e3d7f0361..13e75a43b 100644
--- a/src/frontends/android/app/src/main/res/values-zh-rTW/strings.xml
+++ b/src/frontends/android/app/src/main/res/values-zh-rTW/strings.xml
@@ -212,6 +212,8 @@
         <item quantity="other">Retry in %1$d seconds</item>
     </plurals>
     <string name="cancel_retry">Cancel retry</string>
+    <string name="power_whitelist_title">Disable battery optimizations</string>
+    <string name="power_whitelist_text">Please confirm the next dialog to add the app to the device\'s power whitelist so it can ignore battery optimizations and schedule NAT keep-alives and rekeyings accurately in order to constantly keep reachable while the VPN is established.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">Toggle VPN</string>
diff --git a/src/frontends/android/app/src/main/res/values/strings.xml b/src/frontends/android/app/src/main/res/values/strings.xml
index 4d9fd879f..fb74d3f83 100644
--- a/src/frontends/android/app/src/main/res/values/strings.xml
+++ b/src/frontends/android/app/src/main/res/values/strings.xml
@@ -215,6 +215,8 @@
         <item quantity="other">Retry in %1$d seconds</item>
     </plurals>
     <string name="cancel_retry">Cancel retry</string>
+    <string name="power_whitelist_title">Disable battery optimizations</string>
+    <string name="power_whitelist_text">Please confirm the next dialog to add the app to the device\'s power whitelist so it can ignore battery optimizations and schedule NAT keep-alives and rekeyings accurately in order to constantly keep reachable while the VPN is established.</string>
 
     <!-- Quick Settings tile -->
     <string name="tile_default">Toggle VPN</string>