// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.android_webview.services;
import android.app.Service;
import android.app.job.JobInfo;
import android.app.job.JobScheduler;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.IBinder;
import android.os.ParcelFileDescriptor;
import android.os.ResultReceiver;
import androidx.annotation.IntDef;
import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;
import org.chromium.android_webview.common.services.ServiceNames;
import org.chromium.base.ContextUtils;
import org.chromium.base.FileUtils;
import org.chromium.base.Log;
import org.chromium.base.ResettersForTesting;
import org.chromium.base.metrics.RecordHistogram;
import org.chromium.base.task.PostTask;
import org.chromium.base.task.TaskTraits;
import org.chromium.components.background_task_scheduler.TaskIds;
import org.chromium.components.component_updater.IComponentsProviderService;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;
/** A Service to fetch Components files in WebView and WebLayer. */
public class ComponentsProviderService extends Service {
// Result receiver constants.
public static final int RESULT_OK = 0;
public static final int RESULT_FAILED = 1;
public static final String KEY_RESULT = "RESULT";
// Histogram names.
public static final String HISTOGRAM_GET_FILES_RESULT =
"Android.WebView.ComponentUpdater.GetFilesResult";
public static final String HISTOGRAM_GET_FILES_DURATION =
"Android.WebView.ComponentUpdater.GetFilesDuration";
private static final String TAG = "AW_CPS";
// This should be greater than or equal to the native component updater service interval.
@VisibleForTesting public static final long UPDATE_INTERVAL_MS = TimeUnit.HOURS.toMillis(5);
private static final int JOB_ID = TaskIds.WEBVIEW_COMPONENT_UPDATE_JOB_ID;
private static final int JOB_BACKOFF_POLICY = JobInfo.BACKOFF_POLICY_EXPONENTIAL;
private static final long JOB_INITIAL_BACKOFF_TIME_IN_MS = TimeUnit.MINUTES.toMillis(5);
private static final String SHARED_PREFERENCES_NAME = "ComponentsProviderServicePreferences";
private static final String LAST_SCHEDULED_UPDATE_JOB_TIME = "last_scheduled_update_job_time";
// UMA constants. These values are persisted to logs. Entries can't be reordered and numbers
// can't be reused.
@IntDef({
GetFilesResultCode.SUCCESS,
GetFilesResultCode.FAILED_NOT_INSTALLED,
GetFilesResultCode.FAILED_NO_VERSIONS,
GetFilesResultCode.FAILED_NO_FDS,
GetFilesResultCode.FAILED_OPENING_FDS,
GetFilesResultCode.FAILED_COMPONENT_UPDATER_SAFEMODE_ENABLED
})
private @interface GetFilesResultCode {
int SUCCESS = 0;
int FAILED_NOT_INSTALLED = 1;
int FAILED_NO_VERSIONS = 2;
int FAILED_NO_FDS = 3;
int FAILED_OPENING_FDS = 4;
int FAILED_COMPONENT_UPDATER_SAFEMODE_ENABLED = 5;
// Keep this one at the end and increment appropriately when adding new entries.
int COUNT = 6;
}
/**
* A mockable clock. Returns the current time in ms since the unix epoch. For reference, the
* default implementation is {@code System.currentTimeMillis()}.
*/
@VisibleForTesting
public static interface Clock {
long currentTimeMillis();
}
private static Clock sClockForTesting;
private File mDirectory;
private FutureTask<Void> mDeleteTask;
private final IBinder mBinder =
new IComponentsProviderService.Stub() {
@Override
public void getFilesForComponent(
String componentId, ResultReceiver resultReceiver) {
final long startTime = System.currentTimeMillis();
if (ComponentUpdaterSafeModeUtils.executeSafeModeIfEnabled(mDirectory)) {
Log.w(
TAG,
"Component Updater Reset Mode enabled. Not handing out configs. "
+ componentId);
resultReceiver.send(RESULT_FAILED, /* resultData= */ null);
recordGetFilesResultAndDuration(
GetFilesResultCode.FAILED_COMPONENT_UPDATER_SAFEMODE_ENABLED,
startTime);
return;
}
// Note that there's no need to sanitize input because this method will check if
// there is an existing folder under `mDirectory` with a name that equals the
// received `componentId`. Because `mDirectory` is inside this application's
// data dir, only WebView can modify it.
final File[] components =
mDirectory.listFiles((dir, name) -> name.equals(componentId));
if (components == null || components.length == 0) {
resultReceiver.send(RESULT_FAILED, /* resultData= */ null);
recordGetFilesResultAndDuration(
GetFilesResultCode.FAILED_NOT_INSTALLED, startTime);
return;
}
assert components.length == 1
: "Only one directory should have the name " + componentId;
final File[] versions =
ComponentsProviderPathUtil.getComponentsNewestFirst(components[0]);
if (versions == null || versions.length == 0) {
// This can happen if CUS created a parent directory but was killed before
// it could move content into it. In this case there's nothing old to
// delete.
resultReceiver.send(RESULT_FAILED, /* resultData= */ null);
recordGetFilesResultAndDuration(
GetFilesResultCode.FAILED_NO_VERSIONS, startTime);
return;
}
final File versionDirectory = versions[0];
final HashMap<String, ParcelFileDescriptor> resultMap = new HashMap<>();
try {
recursivelyGetParcelFileDescriptors(
versionDirectory,
versionDirectory.getAbsolutePath() + "/",
resultMap);
if (resultMap.isEmpty()) {
Log.w(TAG, "No file descriptors found for " + componentId);
resultReceiver.send(RESULT_FAILED, /* resultData= */ null);
recordGetFilesResultAndDuration(
GetFilesResultCode.FAILED_NO_FDS, startTime);
return;
}
final Bundle resultData = new Bundle();
resultData.putSerializable(KEY_RESULT, resultMap);
resultReceiver.send(RESULT_OK, resultData);
recordGetFilesResultAndDuration(GetFilesResultCode.SUCCESS, startTime);
} catch (IOException exception) {
Log.w(TAG, exception.getMessage(), exception);
resultReceiver.send(RESULT_FAILED, /* resultData= */ null);
recordGetFilesResultAndDuration(
GetFilesResultCode.FAILED_OPENING_FDS, startTime);
} finally {
closeFileDescriptors(resultMap);
}
}
};
@Nullable
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public void onCreate() {
mDirectory = new File(ComponentsProviderPathUtil.getComponentsServingDirectoryPath());
if (ComponentUpdaterSafeModeUtils.executeSafeModeIfEnabled(mDirectory)) {
JobScheduler jobScheduler =
(JobScheduler)
ContextUtils.getApplicationContext()
.getSystemService(Context.JOB_SCHEDULER_SERVICE);
jobScheduler.cancel(JOB_ID);
return;
}
if (!mDirectory.exists() && !mDirectory.mkdirs()) {
Log.e(TAG, "Failed to create directory " + mDirectory.getAbsolutePath());
return;
}
cleanupOlderFiles();
maybeScheduleComponentUpdateService();
}
private void cleanupOlderFiles() {
final File[] components = mDirectory.listFiles();
if (components == null || components.length == 0) {
return;
}
final List<File> oldFiles = new LinkedList<>();
for (File component : components) {
final File[] versions = ComponentsProviderPathUtil.getComponentsNewestFirst(component);
if (versions == null || versions.length == 0) {
// This can happen if CUS created a parent directory but was killed before it could
// move content into it. In this case there's nothing old to delete.
continue;
}
// Add all directories except the newest (index 0) to oldFiles.
oldFiles.addAll(Arrays.asList(versions).subList(1, versions.length));
}
// Delete old files in background.
mDeleteTask =
new FutureTask<>(
() -> {
for (File file : oldFiles) {
if (!FileUtils.recursivelyDeleteFile(file, null)) {
Log.w(TAG, "Failed to delete " + file.getAbsolutePath());
}
}
return null;
});
PostTask.postTask(TaskTraits.BEST_EFFORT, mDeleteTask);
}
/** This must be called after {@code onCreate()}, otherwise returns a {@code null} object. */
public Future<Void> getDeleteTaskForTesting() {
return mDeleteTask;
}
private void recursivelyGetParcelFileDescriptors(
File file, String pathPrefix, HashMap<String, ParcelFileDescriptor> resultMap)
throws IOException {
if (file.isDirectory()) {
File[] files = file.listFiles();
if (files != null) {
for (File f : files) {
recursivelyGetParcelFileDescriptors(f, pathPrefix, resultMap);
}
}
} else {
resultMap.put(
file.getAbsolutePath().replace(pathPrefix, ""),
ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY));
}
}
private void closeFileDescriptors(HashMap<String, ParcelFileDescriptor> map) {
assert map != null : "closeFileDescriptors called with a null map";
for (ParcelFileDescriptor fileDescriptor : map.values()) {
try {
fileDescriptor.close();
} catch (IOException exception) {
Log.w(TAG, exception.getMessage());
}
}
}
/**
* Schedule an update job if no job is currently scheduled, and the last time the job was
* scheduled was more than UPDATE_INTERVAL_MS ago.
*/
@VisibleForTesting
public static void maybeScheduleComponentUpdateService() {
Context context = ContextUtils.getApplicationContext();
JobScheduler jobScheduler =
(JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
if (isJobScheduled(jobScheduler, JOB_ID)) {
return;
}
// TODO(crbug.com/40796101): schedule it as a periodic job.
final SharedPreferences sharedPreferences =
ContextUtils.getApplicationContext()
.getSharedPreferences(SHARED_PREFERENCES_NAME, Context.MODE_PRIVATE);
long currentTime =
sClockForTesting != null
? sClockForTesting.currentTimeMillis()
: System.currentTimeMillis();
long lastJobScheduleTime = sharedPreferences.getLong(LAST_SCHEDULED_UPDATE_JOB_TIME, 0L);
if (lastJobScheduleTime + UPDATE_INTERVAL_MS > currentTime) {
return;
}
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putLong(LAST_SCHEDULED_UPDATE_JOB_TIME, currentTime);
editor.apply();
ComponentName componentName =
new ComponentName(context, ServiceNames.AW_COMPONENT_UPDATE_SERVICE);
JobInfo.Builder jobBuilder =
new JobInfo.Builder(JOB_ID, componentName)
.setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY)
.setBackoffCriteria(JOB_INITIAL_BACKOFF_TIME_IN_MS, JOB_BACKOFF_POLICY);
if (jobScheduler.schedule(jobBuilder.build()) != JobScheduler.RESULT_SUCCESS) {
Log.e(TAG, "Failed to schedule job for AwComponentUpdateService");
}
}
// TODO(crbug.com/40755263): move this to utils class
@VisibleForTesting
public static boolean isJobScheduled(JobScheduler scheduler, int jobId) {
return scheduler.getPendingJob(jobId) != null;
}
public static void setClockForTesting(Clock clock) {
sClockForTesting = clock;
ResettersForTesting.register(() -> sClockForTesting = null);
}
public static void clearSharedPrefsForTesting() {
ContextUtils.getApplicationContext()
.getSharedPreferences(SHARED_PREFERENCES_NAME, Context.MODE_PRIVATE)
.edit()
.clear()
.apply();
}
private void recordGetFilesResultAndDuration(@GetFilesResultCode int result, long startTime) {
RecordHistogram.recordEnumeratedHistogram(
HISTOGRAM_GET_FILES_RESULT, result, GetFilesResultCode.COUNT);
RecordHistogram.recordTimesHistogram(
HISTOGRAM_GET_FILES_DURATION, System.currentTimeMillis() - startTime);
}
}
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