Refine relocate heuristics

mobile/proguard-rules.pro

@@ -22,7 +22,7 @@
 #-renamesourcefileattribute SourceFile
 
 -if public class be.mygod.librootkotlinx.RootServer {
-    private void doInit(android.content.Context, java.lang.String, boolean);
+    private void doInit(android.content.Context, boolean, java.lang.String);
 }
 -keep class be.mygod.librootkotlinx.RootServer {
     public static void main(java.lang.String[]);

mobile/src/main/java/be/mygod/librootkotlinx/AppProcess.kt

@@ -71,6 +71,13 @@ object AppProcess {
         "/system/bin/app_process"
     }
 
+    /**
+     * Try to guess whether enabling relocation would work best.
+     * It seems some Android 5-7 devices give random permission denials without relocation.
+     * See also VPNHotspot#173.
+     */
+    val shouldRelocateHeuristics get() = Build.VERSION.SDK_INT < 26 || myExeCanonical.startsWith("/data/")
+
     /**
      * To workaround Samsung's stupid kernel patch that prevents exec, we need to relocate exe outside of /data.
      * See also: https://github.com/Chainfire/librootjava/issues/19

mobile/src/main/java/be/mygod/librootkotlinx/RootServer.kt

@@ -131,7 +131,7 @@ class RootServer {
             Logger.me.w(line)
         }
     }
-    private fun doInit(context: Context, niceName: String, shouldRelocate: Boolean = false) {
+    private fun doInit(context: Context, shouldRelocate: Boolean, niceName: String) {
         try {
             val (reader, writer) = try {
                 process = ProcessBuilder("su").start()
@@ -207,22 +207,12 @@ class RootServer {
      * Initialize a RootServer synchronously, can throw a lot of exceptions.
      *
      * @param context Any [Context] from the app.
+     * @param shouldRelocate Whether app process should be copied first. See also [AppProcess.shouldRelocateHeuristics].
      * @param niceName Name to call the rooted Java process.
      */
-    suspend fun init(context: Context, niceName: String = "${context.packageName}:root") {
-        withContext(Dispatchers.IO) {
-            if (AppProcess.myExeCanonical.startsWith("/data/")) doInit(context, niceName, true) else try {  // #173
-                doInit(context, niceName)
-            } catch (e: LaunchException) {
-                try {
-                    doInit(context, niceName, true)
-                } catch (e2: LaunchException) {
-                    e2.addSuppressed(e)
-                    throw e2
-                }
-                Logger.me.w("Root without relocation has failed", RuntimeException(e))
-            }
-        }
+    suspend fun init(context: Context, shouldRelocate: Boolean = false,
+                     niceName: String = "${context.packageName}:root") {
+        withContext(Dispatchers.IO) { doInit(context, shouldRelocate, niceName) }
         callbackListenerExit = GlobalScope.async(Dispatchers.IO) {
             val errorReader = async(Dispatchers.IO) {
                 try {

mobile/src/main/java/be/mygod/vpnhotspot/root/RootManager.kt

@@ -8,6 +8,7 @@ import be.mygod.librootkotlinx.*
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.util.Services
 import be.mygod.vpnhotspot.util.UnblockCentral
+import com.google.firebase.crashlytics.FirebaseCrashlytics
 import kotlinx.parcelize.Parcelize
 import timber.log.Timber
 
@@ -45,7 +46,10 @@ object RootManager : RootSession(), Logger {
 
     override suspend fun initServer(server: RootServer) {
         Logger.me = this
-        server.init(app.deviceStorage)
+        AppProcess.shouldRelocateHeuristics.let {
+            FirebaseCrashlytics.getInstance().setCustomKey("RootManager.relocateEnabled", it)
+            server.init(app.deviceStorage, it)
+        }
         server.execute(RootInit())
     }
 }