android: use PackageManager to determine install AppSourceChecker

We were using MaybeGoogle to determine whether the app was installed from the Play Store, but this has not worked since the refactor.
Fixes tailscale/tailscale#13442
Updates tailscale/corp#23283

Signed-off-by: kari-ts <kari@tailscale.com>

android/src/main/java/com/tailscale/ipn/App.kt

@@ -77,7 +77,7 @@ class App : UninitializedApp(), libtailscale.AppContext, ViewModelStoreOwner {
 
   override fun getPlatformDNSConfig(): String = dns.dnsConfigAsString
 
-  override fun isPlayVersion(): Boolean = MaybeGoogle.isGoogle()
+  override fun getInstallSource(): String = AppSourceChecker.getInstallSource(this)
 
   override fun shouldUseGoogleDNSFallback() : Boolean = BuildConfig.USE_GOOGLE_DNS_FALLBACK
 

android/src/main/java/com/tailscale/ipn/AppSourceChecker.kt

@@ -0,0 +1,34 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+package com.tailscale.ipn
+
+import android.content.Context
+import android.os.Build
+import android.util.Log
+
+object AppSourceChecker {
+
+  const val TAG = "AppSourceChecker"
+
+  fun getInstallSource(context: Context): String {
+    val packageManager = context.packageManager
+    val packageName = context.packageName
+    Log.d(TAG, "Package name: $packageName")
+
+    val installerPackageName = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+        packageManager.getInstallSourceInfo(packageName).installingPackageName
+    } else {
+        packageManager.getInstallerPackageName(packageName)
+    }
+
+    Log.d(TAG, "Installer package name: $installerPackageName")
+
+    return when (installerPackageName) {
+        "com.android.vending" -> "googleplay"
+        "org.fdroid.fdroid" -> "fdroid"
+        "com.amazon.venezia" -> "amazon"
+        null -> "unknown"
+        else -> "unknown($installerPackageName)"
+    }
+}
+}

android/src/main/java/com/tailscale/ipn/MaybeGoogle.java

@@ -1,35 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-package com.tailscale.ipn;
-
-import android.app.Activity;
-
-import java.lang.reflect.Method;
-
-public class MaybeGoogle {
-    static boolean isGoogle() {
-        return getGoogle() != null;
-    }
-
-    static String getIdTokenForActivity(Activity act) {
-        Class<?> google = getGoogle();
-        if (google == null) {
-            return "";
-        }
-        try {
-            Method method = google.getMethod("getIdTokenForActivity", Activity.class);
-            return (String) method.invoke(null, act);
-        } catch (Exception e) {
-            return "";
-        }
-    }
-
-    private static Class getGoogle() {
-        try {
-            return Class.forName("com.tailscale.ipn.Google");
-        } catch (ClassNotFoundException e) {
-            return null;
-        }
-    }
-}

libtailscale/backend.go

@@ -105,9 +105,7 @@ type settingsFunc func(*router.Config, *dns.OSConfig) error
 func (a *App) runBackend(ctx context.Context) error {
 	paths.AppSharedDir.Store(a.dataDir)
 	hostinfo.SetOSVersion(a.osVersion())
-	if !a.appCtx.IsPlayVersion() {
+	hostinfo.SetPackage(a.appCtx.GetInstallSource())
-		hostinfo.SetPackage("nogoogle")
-	}
 	deviceModel := a.modelName()
 	if a.isChromeOS() {
 		deviceModel = "ChromeOS: " + deviceModel

libtailscale/interfaces.go

@@ -33,9 +33,8 @@ type AppContext interface {
 	// GetModelName gets the Android device's model name.
 	GetModelName() (string, error)
 
-	// IsPlayVersion reports whether this is the Google Play version of the app
+	// GetInstallSource gets information about how the app was installed or updated.
-	// (as opposed to F-droid/sideloaded).
+	GetInstallSource() string
-	IsPlayVersion() bool
 
 	// ShouldUseGoogleDNSFallback reports whether or not to use Google for DNS fallback.
 	ShouldUseGoogleDNSFallback() bool