| /* |
| * Copyright (C) 2012 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.internal.util; |
| |
| import android.app.AppOpsManager; |
| import android.content.Context; |
| import android.content.pm.PackageManager; |
| import android.os.Binder; |
| import android.os.Handler; |
| import android.util.Slog; |
| |
| import java.io.PrintWriter; |
| import java.io.StringWriter; |
| |
| /** |
| * Helper functions for dumping the state of system services. |
| */ |
| public final class DumpUtils { |
| private static final String TAG = "DumpUtils"; |
| private static final boolean DEBUG = false; |
| |
| private DumpUtils() { |
| } |
| |
| /** |
| * Helper for dumping state owned by a handler thread. |
| * |
| * Because the caller might be holding an important lock that the handler is |
| * trying to acquire, we use a short timeout to avoid deadlocks. The process |
| * is inelegant but this function is only used for debugging purposes. |
| */ |
| public static void dumpAsync(Handler handler, final Dump dump, PrintWriter pw, |
| final String prefix, long timeout) { |
| final StringWriter sw = new StringWriter(); |
| if (handler.runWithScissors(new Runnable() { |
| @Override |
| public void run() { |
| PrintWriter lpw = new FastPrintWriter(sw); |
| dump.dump(lpw, prefix); |
| lpw.close(); |
| } |
| }, timeout)) { |
| pw.print(sw.toString()); |
| } else { |
| pw.println("... timed out"); |
| } |
| } |
| |
| public interface Dump { |
| void dump(PrintWriter pw, String prefix); |
| } |
| |
| private static void logMessage(PrintWriter pw, String msg) { |
| if (DEBUG) Slog.v(TAG, msg); |
| pw.println(msg); |
| } |
| |
| /** |
| * Verify that caller holds {@link android.Manifest.permission#DUMP}. |
| * |
| * @return true if access should be granted. |
| * @hide |
| */ |
| public static boolean checkDumpPermission(Context context, String tag, PrintWriter pw) { |
| if (context.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) |
| != PackageManager.PERMISSION_GRANTED) { |
| logMessage(pw, "Permission Denial: can't dump " + tag + " from from pid=" |
| + Binder.getCallingPid() + ", uid=" + Binder.getCallingUid() |
| + " due to missing android.permission.DUMP permission"); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| /** |
| * Verify that caller holds |
| * {@link android.Manifest.permission#PACKAGE_USAGE_STATS} and that they |
| * have {@link AppOpsManager#OP_GET_USAGE_STATS} access. |
| * |
| * @return true if access should be granted. |
| * @hide |
| */ |
| public static boolean checkUsageStatsPermission(Context context, String tag, PrintWriter pw) { |
| // System internals always get access |
| final int uid = Binder.getCallingUid(); |
| switch (uid) { |
| case android.os.Process.ROOT_UID: |
| case android.os.Process.SYSTEM_UID: |
| case android.os.Process.SHELL_UID: |
| return true; |
| } |
| |
| // Caller always needs to hold permission |
| if (context.checkCallingOrSelfPermission(android.Manifest.permission.PACKAGE_USAGE_STATS) |
| != PackageManager.PERMISSION_GRANTED) { |
| logMessage(pw, "Permission Denial: can't dump " + tag + " from from pid=" |
| + Binder.getCallingPid() + ", uid=" + Binder.getCallingUid() |
| + " due to missing android.permission.PACKAGE_USAGE_STATS permission"); |
| return false; |
| } |
| |
| // And finally, caller needs to have appops access; this is totally |
| // hacky, but it's the easiest way to wire this up without retrofitting |
| // Binder.dump() to pass through package names. |
| final AppOpsManager appOps = context.getSystemService(AppOpsManager.class); |
| final String[] pkgs = context.getPackageManager().getPackagesForUid(uid); |
| if (pkgs != null) { |
| for (String pkg : pkgs) { |
| switch (appOps.checkOpNoThrow(AppOpsManager.OP_GET_USAGE_STATS, uid, pkg)) { |
| case AppOpsManager.MODE_ALLOWED: |
| if (DEBUG) Slog.v(TAG, "Found package " + pkg + " with " |
| + "android:get_usage_stats allowed"); |
| return true; |
| case AppOpsManager.MODE_DEFAULT: |
| if (DEBUG) Slog.v(TAG, "Found package " + pkg + " with " |
| + "android:get_usage_stats default"); |
| return true; |
| } |
| } |
| } |
| |
| logMessage(pw, "Permission Denial: can't dump " + tag + " from from pid=" |
| + Binder.getCallingPid() + ", uid=" + Binder.getCallingUid() |
| + " due to android:get_usage_stats app-op not allowed"); |
| return false; |
| } |
| |
| /** |
| * Verify that caller holds both {@link android.Manifest.permission#DUMP} |
| * and {@link android.Manifest.permission#PACKAGE_USAGE_STATS}, and that |
| * they have {@link AppOpsManager#OP_GET_USAGE_STATS} access. |
| * |
| * @return true if access should be granted. |
| * @hide |
| */ |
| public static boolean checkDumpAndUsageStatsPermission(Context context, String tag, |
| PrintWriter pw) { |
| return checkDumpPermission(context, tag, pw) && checkUsageStatsPermission(context, tag, pw); |
| } |
| } |