Properly protect cell location.
Test: manual
bug:38489777
diff --git a/src/com/android/phone/LocationAccessPolicy.java b/src/com/android/phone/LocationAccessPolicy.java
new file mode 100644
index 0000000..9f863a3
--- /dev/null
+++ b/src/com/android/phone/LocationAccessPolicy.java
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.phone;
+
+import android.Manifest;
+import android.annotation.NonNull;
+import android.annotation.UserIdInt;
+import android.app.ActivityManager;
+import android.app.AppOpsManager;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.content.pm.UserInfo;
+import android.os.Build;
+import android.os.UserHandle;
+import android.os.UserManager;
+import android.provider.Settings;
+
+import java.util.List;
+
+/**
+ * Helper for performing location access checks.
+ */
+final class LocationAccessPolicy {
+
+ private LocationAccessPolicy() {
+ /* do nothing - hide ctor */
+ }
+
+ /**
+ * API to determine if the caller has permissions to get cell location.
+ *
+ * @param pkgName Package name of the application requesting access
+ * @param uid The uid of the package
+ * @return boolean true or false if permissions is granted
+ */
+ static boolean canAccessCellLocation(@NonNull Context context, @NonNull String pkgName,
+ int uid) throws SecurityException {
+ context.getSystemService(AppOpsManager.class).checkPackage(uid, pkgName);
+ // We always require the location permission and also require the
+ // location mode to be on for non-legacy apps. Legacy apps are
+ // required to be in the foreground to at least mitigate the case
+ // where a legacy app the user is not using tracks their location.
+ if (!hasUidLocationPermission(context, pkgName, uid)
+ || (!isLocationModeEnabled(context, UserHandle.getUserId(uid)))
+ && !isLegacyForeground(context, pkgName)) {
+ return false;
+ }
+ // If the user or profile is current, permission is granted.
+ // Otherwise, uid must have INTERACT_ACROSS_USERS_FULL permission.
+ return isCurrentProfile(context, uid) || checkInteractAcrossUsersFull(context);
+ }
+
+ private static boolean isLocationModeEnabled(@NonNull Context context, @UserIdInt int userId) {
+ return Settings.Secure.getIntForUser(context.getContentResolver(),
+ Settings.Secure.LOCATION_MODE, Settings.Secure.LOCATION_MODE_OFF, userId)
+ != Settings.Secure.LOCATION_MODE_OFF;
+ }
+
+ private static boolean isLegacyForeground(@NonNull Context context, @NonNull String pkgName) {
+ return isLegacyVersion(context, pkgName) && isForegroundApp(context, pkgName);
+ }
+
+ private static boolean isLegacyVersion(@NonNull Context context, @NonNull String pkgName) {
+ try {
+ if (context.getPackageManager().getApplicationInfo(pkgName, 0)
+ .targetSdkVersion <= Build.VERSION_CODES.O) {
+ return true;
+ }
+ } catch (PackageManager.NameNotFoundException e) {
+ // In case of exception, assume known app (more strict checking)
+ // Note: This case will never happen since checkPackage is
+ // called to verify validity before checking app's version.
+ }
+ return false;
+ }
+
+ private static boolean isForegroundApp(@NonNull Context context, @NonNull String pkgName) {
+ final ActivityManager am = context.getSystemService(ActivityManager.class);
+ final List<ActivityManager.RunningTaskInfo> tasks = am.getRunningTasks(1);
+ if (!tasks.isEmpty()) {
+ return pkgName.equals(tasks.get(0).topActivity.getPackageName());
+ }
+ return false;
+ }
+
+ private static boolean checkInteractAcrossUsersFull(@NonNull Context context) {
+ return context.checkCallingOrSelfPermission(
+ android.Manifest.permission.INTERACT_ACROSS_USERS_FULL)
+ == PackageManager.PERMISSION_GRANTED;
+ }
+
+ private static boolean hasUidLocationPermission(@NonNull Context context,
+ @NonNull String pkgName, int uid) {
+ // Grating ACCESS_FINE_LOCATION to an app automatically grants it ACCESS_COARSE_LOCATION.
+ if ((context.checkCallingOrSelfPermission(
+ Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED)) {
+ final int opCode = AppOpsManager.permissionToOpCode(
+ Manifest.permission.ACCESS_COARSE_LOCATION);
+ if (opCode != AppOpsManager.OP_NONE) {
+ return context.getSystemService(AppOpsManager.class).noteOp(opCode, uid, pkgName)
+ == AppOpsManager.MODE_ALLOWED;
+ }
+ }
+ return false;
+ }
+
+ private static boolean isCurrentProfile(@NonNull Context context, int uid) {
+ final int currentUser = ActivityManager.getCurrentUser();
+ final int callingUserId = UserHandle.getUserId(uid);
+ if (callingUserId == currentUser) {
+ return true;
+ } else {
+ List<UserInfo> userProfiles = context.getSystemService(
+ UserManager.class).getProfiles(currentUser);
+ for (UserInfo user: userProfiles) {
+ if (user.id == callingUserId) {
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+}