| /* |
| * 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.role; |
| |
| import android.annotation.CheckResult; |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.annotation.UserIdInt; |
| import android.annotation.WorkerThread; |
| import android.os.Environment; |
| import android.os.Handler; |
| import android.util.ArrayMap; |
| import android.util.ArraySet; |
| import android.util.AtomicFile; |
| import android.util.Slog; |
| import android.util.Xml; |
| |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.os.BackgroundThread; |
| import com.android.internal.util.function.pooled.PooledLambda; |
| |
| import libcore.io.IoUtils; |
| |
| import org.xmlpull.v1.XmlPullParser; |
| import org.xmlpull.v1.XmlPullParserException; |
| import org.xmlpull.v1.XmlSerializer; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.nio.charset.StandardCharsets; |
| |
| /** |
| * Stores the state of roles for a user. |
| */ |
| public class RoleUserState { |
| |
| private static final String LOG_TAG = RoleUserState.class.getSimpleName(); |
| |
| public static final int VERSION_UNDEFINED = -1; |
| |
| private static final String ROLES_FILE_NAME = "roles.xml"; |
| |
| private static final String TAG_ROLES = "roles"; |
| private static final String TAG_ROLE = "role"; |
| private static final String TAG_HOLDER = "holder"; |
| private static final String ATTRIBUTE_VERSION = "version"; |
| private static final String ATTRIBUTE_NAME = "name"; |
| |
| @UserIdInt |
| private final int mUserId; |
| |
| @GuardedBy("RoleManagerService.mLock") |
| private int mVersion = VERSION_UNDEFINED; |
| |
| /** |
| * Maps role names to its holders' package names. The values should never be null. |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| private ArrayMap<String, ArraySet<String>> mRoles = new ArrayMap<>(); |
| |
| @GuardedBy("RoleManagerService.mLock") |
| private boolean mDestroyed; |
| |
| private final Handler mWriteHandler = new Handler(BackgroundThread.getHandler().getLooper()); |
| |
| public RoleUserState(@UserIdInt int userId) { |
| mUserId = userId; |
| } |
| |
| /** |
| * Get the version of this user state. |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| public int getVersionLocked() { |
| throwIfDestroyedLocked(); |
| return mVersion; |
| } |
| |
| /** |
| * Set the version of this user state. |
| * |
| * @param version the version to set |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| public void setVersionLocked(int version) { |
| throwIfDestroyedLocked(); |
| mVersion = version; |
| } |
| |
| /** |
| * Get whether the role is available. |
| * |
| * @param roleName the name of the role to get the holders for |
| * |
| * @return whether the role is available |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| public boolean isRoleAvailableLocked(@NonNull String roleName) { |
| throwIfDestroyedLocked(); |
| return mRoles.containsKey(roleName); |
| } |
| |
| /** |
| * Get the holders of a role. |
| * |
| * @param roleName the name of the role to query for |
| * |
| * @return the set of role holders. {@code null} should not be returned and indicates an issue. |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| @Nullable |
| public ArraySet<String> getRoleHoldersLocked(@NonNull String roleName) { |
| throwIfDestroyedLocked(); |
| return mRoles.get(roleName); |
| } |
| |
| /** |
| * Add a holder to a role. |
| * |
| * @param roleName the name of the role to add the holder to |
| * @param packageName the package name of the new holder |
| * |
| * @return {@code false} only if the set of role holders is null, which should not happen and |
| * indicates an issue. |
| */ |
| @CheckResult |
| @GuardedBy("RoleManagerService.mLock") |
| public boolean addRoleHolderLocked(@NonNull String roleName, @NonNull String packageName) { |
| throwIfDestroyedLocked(); |
| ArraySet<String> roleHolders = mRoles.get(roleName); |
| if (roleHolders == null) { |
| return false; |
| } |
| roleHolders.add(packageName); |
| return true; |
| } |
| |
| /** |
| * Remove a holder from a role. |
| * |
| * @param roleName the name of the role to remove the holder from |
| * @param packageName the package name of the holder to remove |
| * |
| * @return {@code false} only if the set of role holders is null, which should not happen and |
| * indicates an issue. |
| */ |
| @CheckResult |
| @GuardedBy("RoleManagerService.mLock") |
| public boolean removeRoleHolderLocked(@NonNull String roleName, @NonNull String packageName) { |
| throwIfDestroyedLocked(); |
| ArraySet<String> roleHolders = mRoles.get(roleName); |
| if (roleHolders == null) { |
| return false; |
| } |
| roleHolders.remove(packageName); |
| return true; |
| } |
| |
| /** |
| * Schedule writing the state to file. |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| public void writeAsyncLocked() { |
| throwIfDestroyedLocked(); |
| int version = mVersion; |
| ArrayMap<String, ArraySet<String>> roles = new ArrayMap<>(); |
| for (int i = 0, size = mRoles.size(); i < size; ++i) { |
| String roleName = mRoles.keyAt(i); |
| ArraySet<String> roleHolders = mRoles.valueAt(i); |
| roleHolders = new ArraySet<>(roleHolders); |
| roles.put(roleName, roleHolders); |
| } |
| mWriteHandler.removeCallbacksAndMessages(null); |
| mWriteHandler.sendMessage(PooledLambda.obtainMessage(this::writeSync, version, roles)); |
| } |
| |
| @WorkerThread |
| private void writeSync(int version, @NonNull ArrayMap<String, ArraySet<String>> roles) { |
| AtomicFile destination = new AtomicFile(getFile(mUserId), "roles-" + mUserId); |
| FileOutputStream out = null; |
| try { |
| out = destination.startWrite(); |
| |
| XmlSerializer serializer = Xml.newSerializer(); |
| serializer.setOutput(out, StandardCharsets.UTF_8.name()); |
| serializer.setFeature( |
| "http://xmlpull.org/v1/doc/features.html#indent-output", true); |
| serializer.startDocument(null, true); |
| |
| serializeRoles(serializer, version, roles); |
| |
| serializer.endDocument(); |
| destination.finishWrite(out); |
| } catch (Throwable t) { |
| // Any error while writing is fatal. |
| Slog.wtf(LOG_TAG, "Failed to write roles file, restoring backup", t); |
| destination.failWrite(out); |
| } finally { |
| IoUtils.closeQuietly(out); |
| } |
| } |
| |
| @WorkerThread |
| private void serializeRoles(@NonNull XmlSerializer serializer, int version, |
| @NonNull ArrayMap<String, ArraySet<String>> roles) throws IOException { |
| serializer.startTag(null, TAG_ROLES); |
| serializer.attribute(null, ATTRIBUTE_VERSION, Integer.toString(version)); |
| for (int i = 0, size = roles.size(); i < size; ++i) { |
| String roleName = roles.keyAt(i); |
| ArraySet<String> roleHolders = roles.valueAt(i); |
| serializer.startTag(null, TAG_ROLE); |
| serializer.attribute(null, ATTRIBUTE_NAME, roleName); |
| serializeRoleHolders(serializer, roleHolders); |
| serializer.endTag(null, TAG_ROLE); |
| } |
| serializer.endTag(null, TAG_ROLES); |
| } |
| |
| @WorkerThread |
| private void serializeRoleHolders(@NonNull XmlSerializer serializer, |
| @NonNull ArraySet<String> roleHolders) throws IOException { |
| for (int i = 0, size = roleHolders.size(); i < size; ++i) { |
| String roleHolder = roleHolders.valueAt(i); |
| serializer.startTag(null, TAG_HOLDER); |
| serializer.attribute(null, ATTRIBUTE_NAME, roleHolder); |
| serializer.endTag(null, TAG_HOLDER); |
| } |
| } |
| |
| /** |
| * Read the state from file. |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| public void readSyncLocked() { |
| if (mRoles != null) { |
| throw new IllegalStateException("This RoleUserState has already read the XML file"); |
| } |
| File file = getFile(mUserId); |
| FileInputStream in; |
| try { |
| in = new AtomicFile(file).openRead(); |
| } catch (FileNotFoundException e) { |
| Slog.i(LOG_TAG, "No roles file found"); |
| return; |
| } |
| |
| try { |
| XmlPullParser parser = Xml.newPullParser(); |
| parser.setInput(in, null); |
| parseXmlLocked(parser); |
| } catch (XmlPullParserException | IOException e) { |
| throw new IllegalStateException("Failed to parse roles file: " + file , e); |
| } finally { |
| IoUtils.closeQuietly(in); |
| } |
| } |
| |
| private void parseXmlLocked(@NonNull XmlPullParser parser) throws IOException, |
| XmlPullParserException { |
| int outerDepth = parser.getDepth(); |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { |
| if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) { |
| continue; |
| } |
| if (parser.getName().equals(TAG_ROLES)) { |
| parseRolesLocked(parser); |
| return; |
| } |
| } |
| } |
| |
| private void parseRolesLocked(@NonNull XmlPullParser parser) throws IOException, |
| XmlPullParserException { |
| mVersion = Integer.parseInt(parser.getAttributeValue(null, ATTRIBUTE_VERSION)); |
| mRoles = new ArrayMap<>(); |
| int outerDepth = parser.getDepth(); |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { |
| if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) { |
| continue; |
| } |
| if (parser.getName().equals(TAG_ROLE)) { |
| String roleName = parser.getAttributeValue(null, ATTRIBUTE_NAME); |
| ArraySet<String> roleHolders = parseRoleHoldersLocked(parser); |
| mRoles.put(roleName, roleHolders); |
| } |
| } |
| } |
| |
| @NonNull |
| private ArraySet<String> parseRoleHoldersLocked(@NonNull XmlPullParser parser) |
| throws IOException, XmlPullParserException { |
| ArraySet<String> roleHolders = new ArraySet<>(); |
| int outerDepth = parser.getDepth(); |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { |
| if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) { |
| continue; |
| } |
| if (parser.getName().equals(TAG_HOLDER)) { |
| String roleHolder = parser.getAttributeValue(null, ATTRIBUTE_NAME); |
| roleHolders.add(roleHolder); |
| } |
| } |
| return roleHolders; |
| } |
| |
| /** |
| * Destroy this state and delete the corresponding file. Any pending writes to the file will be |
| * cancelled and any future interaction with this state will throw an exception. |
| */ |
| @GuardedBy("RoleManagerService.mLock") |
| public void destroySyncLocked() { |
| throwIfDestroyedLocked(); |
| mWriteHandler.removeCallbacksAndMessages(null); |
| getFile(mUserId).delete(); |
| mDestroyed = true; |
| } |
| |
| @GuardedBy("RoleManagerService.mLock") |
| private void throwIfDestroyedLocked() { |
| if (mDestroyed) { |
| throw new IllegalStateException("This RoleUserState has already been destroyed"); |
| } |
| } |
| |
| private static @NonNull File getFile(@UserIdInt int userId) { |
| return new File(Environment.getUserSystemDirectory(userId), ROLES_FILE_NAME); |
| } |
| } |