| /* |
| * Copyright (C) 2021 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.server.pm; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.os.SystemClock; |
| import android.util.ArrayMap; |
| import android.util.Pair; |
| |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.util.IndentingPrintWriter; |
| |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * Tracks for the installer package name and installing app package name of silent updates. |
| * This class is used to throttle repeated silent updates of the same installer and application |
| * in the {@link PackageInstallerSession}. |
| */ |
| public class SilentUpdatePolicy { |
| // The default throttle time to prevent the installer from silently updating the same app |
| // repeatedly. |
| private static final long SILENT_UPDATE_THROTTLE_TIME_MS = TimeUnit.SECONDS.toMillis(30); |
| |
| // Map to the uptime timestamp for each installer and app of the silent update. |
| @GuardedBy("mSilentUpdateInfos") |
| private final ArrayMap<Pair<String, String>, Long> mSilentUpdateInfos = new ArrayMap<>(); |
| |
| // An installer allowed for the unlimited silent updates within the throttle time |
| @GuardedBy("mSilentUpdateInfos") |
| private String mAllowUnlimitedSilentUpdatesInstaller; |
| |
| @GuardedBy("mSilentUpdateInfos") |
| private long mSilentUpdateThrottleTimeMs = SILENT_UPDATE_THROTTLE_TIME_MS; |
| |
| /** |
| * Checks if the silent update is allowed by the given installer and app package name. |
| * |
| * @param installerPackageName The installer package name to check |
| * @param packageName The package name which is installing |
| * @return true if the silent update is allowed. |
| */ |
| public boolean isSilentUpdateAllowed(@Nullable String installerPackageName, |
| @NonNull String packageName) { |
| if (installerPackageName == null) { |
| // Always true for the installer from Shell |
| return true; |
| } |
| final long lastSilentUpdatedMs = getTimestampMs(installerPackageName, packageName); |
| final long throttleTimeMs; |
| synchronized (mSilentUpdateInfos) { |
| throttleTimeMs = mSilentUpdateThrottleTimeMs; |
| } |
| return SystemClock.uptimeMillis() - lastSilentUpdatedMs > throttleTimeMs; |
| } |
| |
| /** |
| * Adding track for the installer package name and installing app of a silent update. This is |
| * used to determine whether a silent update is allowed. |
| * |
| * @param installerPackageName The installer package name |
| * @param packageName The package name which is installing |
| */ |
| public void track(@Nullable String installerPackageName, @NonNull String packageName) { |
| if (installerPackageName == null) { |
| // No need to track the installer from Shell. |
| return; |
| } |
| synchronized (mSilentUpdateInfos) { |
| if (mAllowUnlimitedSilentUpdatesInstaller != null |
| && mAllowUnlimitedSilentUpdatesInstaller.equals(installerPackageName)) { |
| return; |
| } |
| final long uptime = SystemClock.uptimeMillis(); |
| pruneLocked(uptime); |
| |
| final Pair<String, String> key = Pair.create(installerPackageName, packageName); |
| mSilentUpdateInfos.put(key, uptime); |
| } |
| } |
| |
| /** |
| * Set an installer to allow for the unlimited silent updates. Reset the tracker if the |
| * installer package name is <code>null</code>. |
| */ |
| void setAllowUnlimitedSilentUpdates(@Nullable String installerPackageName) { |
| synchronized (mSilentUpdateInfos) { |
| if (installerPackageName == null) { |
| mSilentUpdateInfos.clear(); |
| } |
| mAllowUnlimitedSilentUpdatesInstaller = installerPackageName; |
| } |
| } |
| |
| /** |
| * Set the silent updates throttle time in seconds. |
| * |
| * @param throttleTimeInSeconds The throttle time to set, or <code>-1</code> to restore the |
| * value to the default. |
| */ |
| void setSilentUpdatesThrottleTime(long throttleTimeInSeconds) { |
| synchronized (mSilentUpdateInfos) { |
| mSilentUpdateThrottleTimeMs = throttleTimeInSeconds >= 0 |
| ? TimeUnit.SECONDS.toMillis(throttleTimeInSeconds) |
| : SILENT_UPDATE_THROTTLE_TIME_MS; |
| } |
| } |
| |
| private void pruneLocked(long uptime) { |
| final int size = mSilentUpdateInfos.size(); |
| for (int i = size - 1; i >= 0; i--) { |
| final long lastSilentUpdatedMs = mSilentUpdateInfos.valueAt(i); |
| if (uptime - lastSilentUpdatedMs > mSilentUpdateThrottleTimeMs) { |
| mSilentUpdateInfos.removeAt(i); |
| } |
| } |
| } |
| |
| /** |
| * Get the timestamp by the given installer and app package name. {@code -1} is returned if not |
| * exist. |
| */ |
| private long getTimestampMs(@NonNull String installerPackageName, @NonNull String packageName) { |
| final Pair<String, String> key = Pair.create(installerPackageName, packageName); |
| final Long timestampMs; |
| synchronized (mSilentUpdateInfos) { |
| timestampMs = mSilentUpdateInfos.get(key); |
| } |
| return timestampMs != null ? timestampMs : -1; |
| } |
| |
| void dump(IndentingPrintWriter pw) { |
| synchronized (mSilentUpdateInfos) { |
| if (mSilentUpdateInfos.isEmpty()) { |
| return; |
| } |
| pw.println("Last silent updated Infos:"); |
| pw.increaseIndent(); |
| final int size = mSilentUpdateInfos.size(); |
| for (int i = 0; i < size; i++) { |
| final Pair<String, String> key = mSilentUpdateInfos.keyAt(i); |
| if (key == null) { |
| continue; |
| } |
| pw.printPair("installerPackageName", key.first); |
| pw.printPair("packageName", key.second); |
| pw.printPair("silentUpdatedMillis", mSilentUpdateInfos.valueAt(i)); |
| pw.println(); |
| } |
| pw.decreaseIndent(); |
| } |
| } |
| } |