| /* |
| * Copyright (C) 2020 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. |
| */ |
| |
| @file:JvmName("AutoRevokePermissions") |
| |
| package com.android.permissioncontroller.permission.service |
| |
| import android.Manifest |
| import android.app.ActivityManager |
| import android.app.ActivityManager.RunningAppProcessInfo.IMPORTANCE_TOP_SLEEPING |
| import android.app.AppOpsManager |
| import android.app.AppOpsManager.MODE_ALLOWED |
| import android.app.AppOpsManager.MODE_DEFAULT |
| import android.app.job.JobInfo |
| import android.app.job.JobParameters |
| import android.app.job.JobScheduler |
| import android.app.job.JobService |
| import android.app.usage.UsageStats |
| import android.app.usage.UsageStatsManager |
| import android.app.usage.UsageStatsManager.INTERVAL_DAILY |
| import android.app.usage.UsageStatsManager.INTERVAL_MONTHLY |
| import android.content.BroadcastReceiver |
| import android.content.ComponentName |
| import android.content.Context |
| import android.content.Intent |
| import android.content.pm.PackageManager.* |
| import android.os.Process.myUserHandle |
| import android.os.UserHandle |
| import android.os.UserManager |
| import android.permission.PermissionManager |
| import android.provider.DeviceConfig |
| import android.util.Log |
| import androidx.annotation.MainThread |
| import com.android.permissioncontroller.Constants |
| import com.android.permissioncontroller.PermissionControllerStatsLog |
| import com.android.permissioncontroller.PermissionControllerStatsLog.PERMISSION_GRANT_REQUEST_RESULT_REPORTED |
| import com.android.permissioncontroller.PermissionControllerStatsLog.PERMISSION_GRANT_REQUEST_RESULT_REPORTED__RESULT__AUTO_UNUSED_APP_PERMISSION_REVOKED |
| import com.android.permissioncontroller.permission.data.get |
| import com.android.permissioncontroller.permission.data.AppOpLiveData |
| import com.android.permissioncontroller.permission.data.LightAppPermGroupLiveData |
| import com.android.permissioncontroller.permission.data.PackagePermissionsLiveData |
| import com.android.permissioncontroller.permission.data.UserPackageInfosLiveData |
| import com.android.permissioncontroller.permission.model.livedatatypes.LightAppPermGroup |
| import com.android.permissioncontroller.permission.model.livedatatypes.LightPackageInfo |
| import com.android.permissioncontroller.permission.utils.* |
| import com.android.permissioncontroller.permission.utils.Utils.PROPERTY_AUTO_REVOKE_CHECK_FREQUENCY_MILLIS |
| import com.android.permissioncontroller.permission.utils.Utils.PROPERTY_AUTO_REVOKE_UNUSED_THRESHOLD_MILLIS |
| import kotlinx.coroutines.* |
| import kotlinx.coroutines.Dispatchers.IO |
| import kotlinx.coroutines.Dispatchers.Main |
| import java.util.concurrent.TimeUnit.DAYS |
| import java.util.concurrent.TimeUnit.SECONDS |
| import kotlin.random.Random |
| |
| private const val LOG_TAG = "AutoRevokePermissions" |
| private const val DEBUG = false |
| |
| private val UNUSED_THRESHOLD_MS = if (DEBUG) |
| SECONDS.toMillis(1) |
| else |
| DeviceConfig.getLong(DeviceConfig.NAMESPACE_PERMISSIONS, |
| PROPERTY_AUTO_REVOKE_UNUSED_THRESHOLD_MILLIS, |
| DAYS.toMillis(90)) |
| |
| private val CHECK_FREQUENCY_MS = DeviceConfig.getLong( |
| DeviceConfig.NAMESPACE_PERMISSIONS, |
| PROPERTY_AUTO_REVOKE_CHECK_FREQUENCY_MILLIS, |
| DAYS.toMillis(1)) |
| |
| private val SERVER_LOG_ID = |
| PERMISSION_GRANT_REQUEST_RESULT_REPORTED__RESULT__AUTO_UNUSED_APP_PERMISSION_REVOKED |
| |
| private val isAutoRevokeEnabled: Boolean get() { |
| return CHECK_FREQUENCY_MS > 0 && UNUSED_THRESHOLD_MS > 0 |
| } |
| |
| /** |
| * Receiver of the onBoot event. |
| */ |
| class AutoRevokeOnBootReceiver : BroadcastReceiver() { |
| |
| override fun onReceive(context: Context, intent: Intent?) { |
| if (DEBUG) { |
| Log.i(LOG_TAG, "scheduleAutoRevokePermissions " + |
| "with frequency ${CHECK_FREQUENCY_MS}ms" + |
| "and threshold ${UNUSED_THRESHOLD_MS}ms") |
| } |
| val jobInfo = JobInfo.Builder( |
| Constants.AUTO_REVOKE_JOB_ID, |
| ComponentName(context, AutoRevokeService::class.java)) |
| .setPeriodic(CHECK_FREQUENCY_MS) |
| .build() |
| val status = context.getSystemService(JobScheduler::class.java)!!.schedule(jobInfo) |
| if (status != JobScheduler.RESULT_SUCCESS) { |
| Log.e(LOG_TAG, |
| "Could not schedule ${AutoRevokeService::class.java.simpleName}: $status") |
| } |
| } |
| } |
| |
| @MainThread |
| private suspend fun revokePermissionsOnUnusedApps(context: Context) { |
| if (!isAutoRevokeEnabled) { |
| return |
| } |
| |
| val now = System.currentTimeMillis() |
| |
| val unusedApps: MutableList<LightPackageInfo> = UserPackageInfosLiveData[myUserHandle()] |
| .getInitializedValue(staleOk = true) |
| .toMutableList() |
| |
| // TODO eugenesusla: adapt UsageStats into a LiveData |
| val stats = withContext(IO) { |
| context.getSystemService<UsageStatsManager>() |
| .queryUsageStats( |
| if (DEBUG) INTERVAL_DAILY else INTERVAL_MONTHLY, |
| now - UNUSED_THRESHOLD_MS, |
| now) |
| } |
| val profileUsersStats: Deferred<List<List<UsageStats>>> = |
| GlobalScope.async(IO, start = CoroutineStart.LAZY) { |
| context |
| .getSystemService<UserManager>() |
| .enabledProfiles |
| .map { user -> |
| context.forUser(user) |
| .getSystemService<UsageStatsManager>() |
| .queryUsageStats( |
| if (DEBUG) INTERVAL_DAILY else INTERVAL_MONTHLY, |
| now - UNUSED_THRESHOLD_MS, |
| now) |
| } |
| } |
| |
| for (stat in stats) { |
| var lastTimeVisible: Long = stat.lastTimeVisible |
| val pkg = stat.packageName |
| if (context.isPackageCrossProfile(pkg)) { |
| profileUsersStats |
| .await() |
| .fold(lastTimeVisible) { result, profileStats -> |
| val time: Long = profileStats |
| .find { it.packageName == pkg } |
| ?.lastTimeVisible |
| ?: result |
| Math.max(result, time) |
| } |
| } |
| |
| if (now - lastTimeVisible <= UNUSED_THRESHOLD_MS) { |
| unusedApps.removeAll { it.packageName == pkg } |
| } |
| } |
| |
| if (DEBUG) { |
| Log.i(LOG_TAG, "Unused apps: ${unusedApps.map { it.packageName }}") |
| } |
| |
| val manifestExemptPackages: Set<String> = withContext(IO) { |
| context.getSystemService<PermissionManager>() |
| .getAutoRevokeExemptionGrantedPackages() |
| } |
| |
| unusedApps.forEachInParallel(Main) { pkg: LightPackageInfo -> |
| if (pkg.grantedPermissions.isEmpty()) { |
| return@forEachInParallel |
| } |
| |
| val packageName = pkg.packageName |
| if (isPackageAutoRevokeExempt(pkg, manifestExemptPackages)) { |
| return@forEachInParallel |
| } |
| |
| val pkgPermGroups: Map<String, List<String>> = |
| PackagePermissionsLiveData[packageName, myUserHandle()] |
| .getInitializedValue(staleOk = true) |
| |
| pkgPermGroups.entries.forEachInParallel(Main) { (groupName, groupPermNames) -> |
| if (groupName == PackagePermissionsLiveData.NON_RUNTIME_NORMAL_PERMS) { |
| return@forEachInParallel |
| } |
| |
| val group: LightAppPermGroup = |
| LightAppPermGroupLiveData[packageName, groupName, myUserHandle()] |
| .getInitializedValue(staleOk = true) |
| ?: return@forEachInParallel |
| |
| val fixed = group.isBackgroundFixed || group.isForegroundFixed |
| if (!fixed && |
| group.permissions.any { (_, perm) -> perm.isGrantedIncludingAppOp } && |
| !group.isGrantedByDefault && |
| !group.isGrantedByRole) { |
| |
| val revocablePermissions = group.permissions.keys.toList() |
| |
| if (revocablePermissions.isEmpty()) { |
| return@forEachInParallel |
| } |
| |
| if (DEBUG) { |
| Log.i(LOG_TAG, "revokeUnused $packageName - $revocablePermissions") |
| } |
| |
| val uid = group.packageInfo.uid |
| for (permName in revocablePermissions) { |
| PermissionControllerStatsLog.write( |
| PERMISSION_GRANT_REQUEST_RESULT_REPORTED, |
| Random.nextLong(), uid, packageName, permName, false, SERVER_LOG_ID) |
| } |
| |
| val packageImportance = context |
| .getSystemService(ActivityManager::class.java)!! |
| .getPackageImportance(packageName) |
| if (packageImportance > IMPORTANCE_TOP_SLEEPING) { |
| KotlinUtils.revokeBackgroundRuntimePermissions( |
| context.application, group, |
| userFixed = false, oneTime = false, |
| filterPermissions = revocablePermissions) |
| KotlinUtils.revokeForegroundRuntimePermissions( |
| context.application, group, |
| userFixed = false, oneTime = false, |
| filterPermissions = revocablePermissions) |
| |
| for (permission in revocablePermissions) { |
| context.packageManager.updatePermissionFlags( |
| permission, packageName, myUserHandle(), |
| FLAG_PERMISSION_AUTO_REVOKED to true, |
| FLAG_PERMISSION_USER_SET to false) |
| } |
| } else { |
| Log.i(LOG_TAG, |
| "Skipping auto-revoke - app running with importance $packageImportance") |
| } |
| } |
| } |
| } |
| } |
| |
| private suspend fun isPackageAutoRevokeExempt( |
| pkg: LightPackageInfo, |
| manifestExemptPackages: Set<String> |
| ): Boolean { |
| val packageName = pkg.packageName |
| val packageUid = pkg.uid |
| |
| val whitelistAppOpMode = |
| AppOpLiveData[packageName, |
| AppOpsManager.OPSTR_AUTO_REVOKE_PERMISSIONS_IF_UNUSED, packageUid] |
| .getInitializedValue() |
| if (whitelistAppOpMode == MODE_DEFAULT) { |
| // Initial state - whitelist not explicitly overridden by either user or installer |
| |
| if (DEBUG) { |
| // Suppress exemptions to allow debugging |
| return false |
| } |
| |
| if (pkg.targetSdkVersion <= android.os.Build.VERSION_CODES.Q) { |
| // Q- packages exempt by default |
| return true |
| } else { |
| // R+ packages only exempt with manifest attribute |
| return packageName in manifestExemptPackages |
| } |
| } |
| return whitelistAppOpMode != MODE_ALLOWED |
| } |
| |
| private fun Context.isPackageCrossProfile(pkg: String): Boolean { |
| return packageManager.checkPermission( |
| Manifest.permission.INTERACT_ACROSS_PROFILES, pkg) == PERMISSION_GRANTED || |
| packageManager.checkPermission( |
| Manifest.permission.INTERACT_ACROSS_USERS, pkg) == PERMISSION_GRANTED || |
| packageManager.checkPermission( |
| Manifest.permission.INTERACT_ACROSS_USERS_FULL, pkg) == PERMISSION_GRANTED |
| } |
| |
| private fun Context.forUser(user: UserHandle): Context { |
| return Utils.getUserContext(application, user) |
| } |
| |
| private fun Context.forParentUser(): Context { |
| return Utils.getParentUserContext(this) |
| } |
| |
| private inline fun <reified T> Context.getSystemService() = getSystemService(T::class.java)!! |
| |
| /** |
| * A job to check for apps unused in the last [UNUSED_THRESHOLD_MS]ms every |
| * [CHECK_FREQUENCY_MS]ms and [revokePermissionsOnUnusedApps] for them |
| */ |
| class AutoRevokeService : JobService() { |
| var job: Job? = null |
| var jobStartTime: Long = -1L |
| |
| override fun onStartJob(params: JobParameters?): Boolean { |
| if (DEBUG) { |
| Log.i(LOG_TAG, "onStartJob") |
| } |
| |
| jobStartTime = System.currentTimeMillis() |
| job = GlobalScope.launch(Main) { |
| try { |
| revokePermissionsOnUnusedApps(this@AutoRevokeService) |
| } catch (e: Exception) { |
| Log.e(LOG_TAG, "Failed to auto-revoke permissions", e) |
| } |
| jobFinished(params, false) |
| } |
| return true |
| } |
| |
| override fun onStopJob(params: JobParameters?): Boolean { |
| Log.w(LOG_TAG, "onStopJob after ${System.currentTimeMillis() - jobStartTime}ms") |
| job?.cancel() |
| return true |
| } |
| } |
