From 3666147231740dd3c5ab291915f9f6ca4f7b696c Mon Sep 17 00:00:00 2001
From: kari-ts <kari@tailscale.com>
Date: Fri, 20 Sep 2024 09:47:30 -0700
Subject: [PATCH] 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>
---
 .../src/main/java/com/tailscale/ipn/App.kt    |  2 +-
 .../com/tailscale/ipn/AppSourceChecker.kt     | 34 ++++++++++++++++++
 .../java/com/tailscale/ipn/MaybeGoogle.java   | 35 -------------------
 libtailscale/backend.go                       |  4 +--
 libtailscale/interfaces.go                    |  5 ++-
 5 files changed, 38 insertions(+), 42 deletions(-)
 create mode 100644 android/src/main/java/com/tailscale/ipn/AppSourceChecker.kt
 delete mode 100644 android/src/main/java/com/tailscale/ipn/MaybeGoogle.java

diff --git a/android/src/main/java/com/tailscale/ipn/App.kt b/android/src/main/java/com/tailscale/ipn/App.kt
index 95acce5..e03da65 100644
--- a/android/src/main/java/com/tailscale/ipn/App.kt
+++ b/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
 
diff --git a/android/src/main/java/com/tailscale/ipn/AppSourceChecker.kt b/android/src/main/java/com/tailscale/ipn/AppSourceChecker.kt
new file mode 100644
index 0000000..72e39fc
--- /dev/null
+++ b/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)"
+    }
+}
+}
diff --git a/android/src/main/java/com/tailscale/ipn/MaybeGoogle.java b/android/src/main/java/com/tailscale/ipn/MaybeGoogle.java
deleted file mode 100644
index 2eb3bac..0000000
--- a/android/src/main/java/com/tailscale/ipn/MaybeGoogle.java
+++ /dev/null
@@ -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;
-        }
-    }
-}
diff --git a/libtailscale/backend.go b/libtailscale/backend.go
index 908b7e2..247a802 100644
--- a/libtailscale/backend.go
+++ b/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("nogoogle")
-	}
+	hostinfo.SetPackage(a.appCtx.GetInstallSource())
 	deviceModel := a.modelName()
 	if a.isChromeOS() {
 		deviceModel = "ChromeOS: " + deviceModel
diff --git a/libtailscale/interfaces.go b/libtailscale/interfaces.go
index d168fef..7c05166 100644
--- a/libtailscale/interfaces.go
+++ b/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
-	// (as opposed to F-droid/sideloaded).
-	IsPlayVersion() bool
+	// GetInstallSource gets information about how the app was installed or updated.
+	GetInstallSource() string
 
 	// ShouldUseGoogleDNSFallback reports whether or not to use Google for DNS fallback.
 	ShouldUseGoogleDNSFallback() bool