| /* |
| * Copyright (C) 2018 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; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.annotation.UserIdInt; |
| import android.app.ActivityManager; |
| import android.content.ComponentName; |
| import android.content.ContentResolver; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.pm.UserInfo; |
| import android.database.ContentObserver; |
| import android.net.Uri; |
| import android.os.Binder; |
| import android.os.Handler; |
| import android.os.UserHandle; |
| import android.os.UserManager; |
| import android.os.UserManagerInternal; |
| import android.provider.Settings; |
| import android.util.Slog; |
| import android.util.SparseArray; |
| import android.util.SparseBooleanArray; |
| |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.content.PackageMonitor; |
| import com.android.internal.os.BackgroundThread; |
| |
| import java.io.PrintWriter; |
| import java.util.List; |
| |
| /** |
| * Base class for {@link SystemService SystemServices} that support multi user. |
| * |
| * <p>Subclasses of this service are just a facade for the service binder calls - the "real" work |
| * is done by the {@link AbstractPerUserSystemService} subclasses, which are automatically managed |
| * through an user -> service cache. |
| * |
| * <p>It also takes care of other plumbing tasks such as: |
| * |
| * <ul> |
| * <li>Disabling the service when {@link UserManager} restrictions change. |
| * <li>Refreshing the service when its underlying |
| * {@link #getServiceSettingsProperty() Settings property} changed. |
| * <li>Calling the service when other Settings properties changed. |
| * </ul> |
| * |
| * <p>See {@code com.android.server.autofill.AutofillManagerService} for a concrete |
| * (no pun intended) example of how to use it. |
| * |
| * @param <M> "master" service class. |
| * @param <S> "real" service class. |
| * |
| * @hide |
| */ |
| // TODO(b/117779333): improve javadoc above instead of using Autofill as an example |
| public abstract class AbstractMasterSystemService<M extends AbstractMasterSystemService<M, S>, |
| S extends AbstractPerUserSystemService<S, M>> extends SystemService { |
| |
| /** |
| * Log tag |
| */ |
| protected final String mTag = getClass().getSimpleName(); |
| |
| /** |
| * Lock used to synchronize access to internal state; should be acquired before calling a |
| * method whose name ends with {@code locked}. |
| */ |
| protected final Object mLock = new Object(); |
| |
| /** |
| * Whether the service should log debug statements. |
| */ |
| public boolean verbose = false; |
| |
| /** |
| * Whether the service should log verbose statements. |
| */ |
| public boolean debug = false; |
| |
| /** |
| * Users disabled due to {@link UserManager} restrictions, or {@code null} if the service cannot |
| * be disabled through {@link UserManager}. |
| */ |
| @GuardedBy("mLock") |
| @Nullable |
| private final SparseBooleanArray mDisabledUsers; |
| |
| /** |
| * Cache of services per user id. |
| */ |
| @GuardedBy("mLock") |
| private final SparseArray<S> mServicesCache = new SparseArray<>(); |
| |
| /** |
| * Default constructor. |
| * |
| * @param context system context. |
| * @param disallowProperty when not {@code null}, defines a {@link UserManager} restriction that |
| * disables the service. |
| */ |
| protected AbstractMasterSystemService(@NonNull Context context, |
| @Nullable String disallowProperty) { |
| super(context); |
| |
| if (disallowProperty == null) { |
| mDisabledUsers = null; |
| } else { |
| mDisabledUsers = new SparseBooleanArray(); |
| // Hookup with UserManager to disable service when necessary. |
| final UserManager um = context.getSystemService(UserManager.class); |
| final UserManagerInternal umi = LocalServices.getService(UserManagerInternal.class); |
| final List<UserInfo> users = um.getUsers(); |
| for (int i = 0; i < users.size(); i++) { |
| final int userId = users.get(i).id; |
| final boolean disabled = umi.getUserRestriction(userId, disallowProperty); |
| if (disabled) { |
| Slog.i(mTag, "Disabling for user " + userId); |
| mDisabledUsers.put(userId, disabled); |
| } |
| } |
| umi.addUserRestrictionsListener((userId, newRestrictions, prevRestrictions) -> { |
| final boolean disabledNow = |
| newRestrictions.getBoolean(disallowProperty, false); |
| synchronized (mLock) { |
| final boolean disabledBefore = mDisabledUsers.get(userId); |
| if (disabledBefore == disabledNow) { |
| // Nothing changed, do nothing. |
| if (debug) { |
| Slog.d(mTag, "Restriction did not change for user " + userId); |
| return; |
| } |
| } |
| Slog.i(mTag, "Updating for user " + userId + ": disabled=" + disabledNow); |
| mDisabledUsers.put(userId, disabledNow); |
| updateCachedServiceLocked(userId, disabledNow); |
| } |
| }); |
| } |
| startTrackingPackageChanges(); |
| } |
| |
| @Override // from SystemService |
| public void onBootPhase(int phase) { |
| if (phase == PHASE_THIRD_PARTY_APPS_CAN_START) { |
| new SettingsObserver(BackgroundThread.getHandler()); |
| } |
| } |
| |
| @Override // from SystemService |
| public void onUnlockUser(int userId) { |
| synchronized (mLock) { |
| updateCachedServiceLocked(userId); |
| } |
| } |
| |
| @Override // from SystemService |
| public void onCleanupUser(int userId) { |
| synchronized (mLock) { |
| removeCachedServiceLocked(userId); |
| } |
| } |
| |
| /** |
| * Creates a new service that will be added to the cache. |
| * |
| * @param resolvedUserId the resolved user id for the service. |
| * @param disabled whether the service is currently disabled (due to {@link UserManager} |
| * restrictions). |
| * |
| * @return a new instance. |
| */ |
| protected abstract S newServiceLocked(@UserIdInt int resolvedUserId, boolean disabled); |
| |
| /** |
| * Register the service for extra Settings changes (i.e., other than |
| * {@link android.provider.Settings.Secure#USER_SETUP_COMPLETE} or |
| * {@link #getServiceSettingsProperty()}, which are automatically handled). |
| * |
| * <p> Example: |
| * |
| * <pre><code> |
| * resolver.registerContentObserver(Settings.Global.getUriFor( |
| * Settings.Global.AUTOFILL_COMPAT_MODE_ALLOWED_PACKAGES), false, observer, |
| * UserHandle.USER_ALL); |
| * </code></pre> |
| * |
| * <p><b>NOTE: </p>it doesn't need to register for |
| * {@link android.provider.Settings.Secure#USER_SETUP_COMPLETE} or |
| * {@link #getServiceSettingsProperty()}. |
| * |
| */ |
| @SuppressWarnings("unused") |
| protected void registerForExtraSettingsChanges(@NonNull ContentResolver resolver, |
| @NonNull ContentObserver observer) { |
| } |
| |
| /** |
| * Callback for Settings changes that were registered though |
| * {@link #registerForExtraSettingsChanges(ContentResolver, ContentObserver)}. |
| * |
| * @param userId user associated with the change |
| * @param property Settings property changed. |
| */ |
| protected void onSettingsChanged(@UserIdInt int userId, @NonNull String property) { |
| } |
| |
| /** |
| * Gets the service instance for an user, creating an instance if not present in the cache. |
| */ |
| @GuardedBy("mLock") |
| @NonNull |
| protected S getServiceForUserLocked(@UserIdInt int userId) { |
| final int resolvedUserId = ActivityManager.handleIncomingUser(Binder.getCallingPid(), |
| Binder.getCallingUid(), userId, false, false, null, null); |
| S service = mServicesCache.get(resolvedUserId); |
| if (service == null) { |
| final boolean disabled = isDisabledLocked(userId); |
| service = newServiceLocked(resolvedUserId, disabled); |
| if (!disabled) { |
| onServiceEnabledLocked(service, resolvedUserId); |
| } |
| mServicesCache.put(userId, service); |
| } |
| return service; |
| } |
| |
| /** |
| * Gets the <b>existing</b> service instance for a user, returning {@code null} if not already |
| * present in the cache. |
| */ |
| @GuardedBy("mLock") |
| @Nullable |
| protected S peekServiceForUserLocked(@UserIdInt int userId) { |
| final int resolvedUserId = ActivityManager.handleIncomingUser(Binder.getCallingPid(), |
| Binder.getCallingUid(), userId, false, false, null, null); |
| return mServicesCache.get(resolvedUserId); |
| } |
| |
| /** |
| * Updates a cached service for a given user. |
| */ |
| @GuardedBy("mLock") |
| protected void updateCachedServiceLocked(@UserIdInt int userId) { |
| updateCachedServiceLocked(userId, isDisabledLocked(userId)); |
| } |
| |
| /** |
| * Checks whether the service is disabled (through {@link UserManager} restrictions) for the |
| * given user. |
| */ |
| protected boolean isDisabledLocked(@UserIdInt int userId) { |
| return mDisabledUsers == null ? false : mDisabledUsers.get(userId); |
| } |
| |
| /** |
| * Updates a cached service for a given user. |
| * |
| * @param userId user handle. |
| * @param disabled whether the user is disabled. |
| * @return service for the user. |
| */ |
| @GuardedBy("mLock") |
| protected S updateCachedServiceLocked(@UserIdInt int userId, boolean disabled) { |
| final S service = getServiceForUserLocked(userId); |
| if (service != null) { |
| service.updateLocked(disabled); |
| if (!service.isEnabledLocked()) { |
| removeCachedServiceLocked(userId); |
| } else { |
| onServiceEnabledLocked(service, userId); |
| } |
| } |
| return service; |
| } |
| |
| /** |
| * Gets the Settings property that defines the name of the component name used to bind this |
| * service to an external service, or {@code null} when the service is not defined by such |
| * property (for example, if it's a system service defined by framework resources). |
| */ |
| @Nullable |
| protected String getServiceSettingsProperty() { |
| return null; |
| } |
| |
| /** |
| * Callback called after a new service was added to the cache, or an existing service that was |
| * previously disabled gets enabled. |
| * |
| * <p>By default doesn't do anything, but can be overridden by subclasses. |
| */ |
| @SuppressWarnings("unused") |
| protected void onServiceEnabledLocked(@NonNull S service, @UserIdInt int userId) { |
| } |
| |
| /** |
| * Removes a cached service for a given user. |
| * |
| * @return the removed service; |
| */ |
| @GuardedBy("mLock") |
| @NonNull |
| private S removeCachedServiceLocked(@UserIdInt int userId) { |
| final S service = peekServiceForUserLocked(userId); |
| if (service != null) { |
| mServicesCache.delete(userId); |
| onServiceRemoved(service, userId); |
| } |
| return service; |
| } |
| |
| /** |
| * Called after the service is removed from the cache. |
| */ |
| @SuppressWarnings("unused") |
| protected void onServiceRemoved(@NonNull S service, @UserIdInt int userId) { |
| } |
| |
| /** |
| * Visits all services in the cache. |
| */ |
| @GuardedBy("mLock") |
| protected void visitServicesLocked(@NonNull Visitor<S> visitor) { |
| final int size = mServicesCache.size(); |
| for (int i = 0; i < size; i++) { |
| visitor.visit(mServicesCache.valueAt(i)); |
| } |
| } |
| |
| /** |
| * Clear the cache by removing all services. |
| */ |
| @GuardedBy("mLock") |
| protected void clearCacheLocked() { |
| mServicesCache.clear(); |
| } |
| |
| // TODO(b/117779333): support proto |
| protected void dumpLocked(@NonNull String prefix, @NonNull PrintWriter pw) { |
| boolean realDebug = debug; |
| boolean realVerbose = verbose; |
| |
| try { |
| // Temporarily turn on full logging; |
| debug = verbose = true; |
| final int size = mServicesCache.size(); |
| pw.print(prefix); pw.print("Debug: "); pw.print(realDebug); |
| pw.print(" Verbose: "); pw.println(realVerbose); |
| pw.print(prefix); pw.print("Disabled users: "); pw.println(mDisabledUsers); |
| pw.print(prefix); pw.print("Settings property: "); pw.println( |
| getServiceSettingsProperty()); |
| pw.print(prefix); pw.print("Cached services: "); |
| if (size == 0) { |
| pw.println("none"); |
| } else { |
| pw.println(size); |
| final String prefix2 = " "; |
| for (int i = 0; i < size; i++) { |
| pw.print(prefix); pw.print("Service at "); pw.print(i); pw.println(": "); |
| final S service = mServicesCache.valueAt(i); |
| service.dumpLocked(prefix2, pw); |
| pw.println(); |
| } |
| } |
| } finally { |
| debug = realDebug; |
| verbose = realVerbose; |
| } |
| } |
| |
| private void startTrackingPackageChanges() { |
| PackageMonitor monitor = new PackageMonitor() { |
| @Override |
| public void onSomePackagesChanged() { |
| synchronized (mLock) { |
| updateCachedServiceLocked(getChangingUserId()); |
| } |
| } |
| |
| @Override |
| public void onPackageUpdateFinished(String packageName, int uid) { |
| synchronized (mLock) { |
| final String activePackageName = getActiveServicePackageName(); |
| if (packageName.equals(activePackageName)) { |
| removeCachedServiceLocked(getChangingUserId()); |
| } else { |
| handlePackageUpdateLocked(packageName); |
| } |
| } |
| } |
| |
| @Override |
| public void onPackageRemoved(String packageName, int uid) { |
| synchronized (mLock) { |
| final int userId = getChangingUserId(); |
| final S service = peekServiceForUserLocked(userId); |
| if (service != null) { |
| final ComponentName componentName = service.getServiceComponentName(); |
| if (componentName != null) { |
| if (packageName.equals(componentName.getPackageName())) { |
| handleActiveServiceRemoved(userId); |
| } |
| } |
| } |
| } |
| } |
| |
| @Override |
| public boolean onHandleForceStop(Intent intent, String[] packages, |
| int uid, boolean doit) { |
| synchronized (mLock) { |
| final String activePackageName = getActiveServicePackageName(); |
| for (String pkg : packages) { |
| if (pkg.equals(activePackageName)) { |
| if (!doit) { |
| return true; |
| } |
| removeCachedServiceLocked(getChangingUserId()); |
| } else { |
| handlePackageUpdateLocked(pkg); |
| } |
| } |
| } |
| return false; |
| } |
| |
| private void handleActiveServiceRemoved(@UserIdInt int userId) { |
| removeCachedServiceLocked(userId); |
| final String serviceSettingsProperty = getServiceSettingsProperty(); |
| if (serviceSettingsProperty != null) { |
| Settings.Secure.putStringForUser(getContext().getContentResolver(), |
| serviceSettingsProperty, null, userId); |
| } |
| } |
| |
| private String getActiveServicePackageName() { |
| final int userId = getChangingUserId(); |
| final S service = peekServiceForUserLocked(userId); |
| if (service == null) { |
| return null; |
| } |
| final ComponentName serviceComponent = service.getServiceComponentName(); |
| if (serviceComponent == null) { |
| return null; |
| } |
| return serviceComponent.getPackageName(); |
| } |
| |
| @GuardedBy("mLock") |
| private void handlePackageUpdateLocked(String packageName) { |
| visitServicesLocked((s) -> s.handlePackageUpdateLocked(packageName)); |
| } |
| }; |
| |
| // package changes |
| monitor.register(getContext(), null, UserHandle.ALL, true); |
| } |
| |
| /** |
| * Visitor pattern. |
| * |
| * @param <S> visited class. |
| */ |
| public interface Visitor<S> { |
| /** |
| * Visits a service. |
| * |
| * @param service the service to be visited. |
| */ |
| void visit(@NonNull S service); |
| } |
| |
| private final class SettingsObserver extends ContentObserver { |
| SettingsObserver(Handler handler) { |
| super(handler); |
| ContentResolver resolver = getContext().getContentResolver(); |
| final String serviceProperty = getServiceSettingsProperty(); |
| if (serviceProperty != null) { |
| resolver.registerContentObserver(Settings.Secure.getUriFor( |
| serviceProperty), false, this, UserHandle.USER_ALL); |
| } |
| resolver.registerContentObserver(Settings.Secure.getUriFor( |
| Settings.Secure.USER_SETUP_COMPLETE), false, this, UserHandle.USER_ALL); |
| registerForExtraSettingsChanges(resolver, this); |
| } |
| |
| @Override |
| public void onChange(boolean selfChange, Uri uri, @UserIdInt int userId) { |
| if (verbose) Slog.v(mTag, "onChange(): uri=" + uri + ", userId=" + userId); |
| final String property = uri.getLastPathSegment(); |
| if (property.equals(getServiceSettingsProperty()) |
| || property.equals(Settings.Secure.USER_SETUP_COMPLETE)) { |
| synchronized (mLock) { |
| updateCachedServiceLocked(userId); |
| } |
| } else { |
| onSettingsChanged(userId, property); |
| } |
| } |
| } |
| } |