| /* |
| * Copyright (C) 2016 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.webkit; |
| |
| import android.content.Context; |
| import android.content.pm.ApplicationInfo; |
| import android.content.pm.PackageInfo; |
| import android.content.pm.PackageManager.NameNotFoundException; |
| import android.content.pm.Signature; |
| import android.os.Handler; |
| import android.os.UserHandle; |
| import android.util.Base64; |
| import android.util.Slog; |
| import android.webkit.UserPackage; |
| import android.webkit.WebViewFactory; |
| import android.webkit.WebViewProviderInfo; |
| import android.webkit.WebViewProviderResponse; |
| |
| import java.io.PrintWriter; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| |
| /** |
| * Implementation of the WebViewUpdateService. |
| * This class doesn't depend on the android system like the actual Service does and can be used |
| * directly by tests (as long as they implement a SystemInterface). |
| * |
| * This class implements two main features - handling WebView fallback packages and keeping track |
| * of, and preparing, the current WebView implementation. The fallback mechanism is meant to be |
| * uncoupled from the rest of the WebView preparation and does not store any state. The code for |
| * choosing and preparing a WebView implementation needs to keep track of a couple of different |
| * things such as what package is used as WebView implementation. |
| * |
| * The public methods in this class are accessed from WebViewUpdateService either on the UI thread |
| * or on one of multiple Binder threads. This means that the code in this class needs to be |
| * thread-safe. The fallback mechanism shares (almost) no information between threads which makes |
| * it easier to argue about thread-safety (in theory, if timed badly, the fallback mechanism can |
| * incorrectly enable/disable a fallback package but that fault will be corrected when we later |
| * receive an intent for that enabling/disabling). On the other hand, the WebView preparation code |
| * shares state between threads meaning that code that chooses a new WebView implementation or |
| * checks which implementation is being used needs to hold a lock. |
| * |
| * The WebViewUpdateService can be accessed in a couple of different ways. |
| * 1. It is started from the SystemServer at boot - at that point we just initiate some state such |
| * as the WebView preparation class. |
| * 2. The SystemServer calls WebViewUpdateService.prepareWebViewInSystemServer. This happens at boot |
| * and the WebViewUpdateService should not have been accessed before this call. In this call we |
| * enable/disable fallback packages and then choose WebView implementation for the first time. |
| * 3. The update service listens for Intents related to package installs and removals. These intents |
| * are received and processed on the UI thread. Each intent can result in enabling/disabling |
| * fallback packages and changing WebView implementation. |
| * 4. The update service can be reached through Binder calls which are handled on specific binder |
| * threads. These calls can be made from any process. Generally they are used for changing WebView |
| * implementation (from Settings), getting information about the current WebView implementation (for |
| * loading WebView into an app process), or notifying the service about Relro creation being |
| * completed. |
| * |
| * @hide |
| */ |
| public class WebViewUpdateServiceImpl { |
| private static final String TAG = WebViewUpdateServiceImpl.class.getSimpleName(); |
| |
| private SystemInterface mSystemInterface; |
| private WebViewUpdater mWebViewUpdater; |
| final private Context mContext; |
| |
| public WebViewUpdateServiceImpl(Context context, SystemInterface systemInterface) { |
| mContext = context; |
| mSystemInterface = systemInterface; |
| mWebViewUpdater = new WebViewUpdater(mContext, mSystemInterface); |
| } |
| |
| void packageStateChanged(String packageName, int changedState, int userId) { |
| // We don't early out here in different cases where we could potentially early-out (e.g. if |
| // we receive PACKAGE_CHANGED for another user than the system user) since that would |
| // complicate this logic further and open up for more edge cases. |
| updateFallbackStateOnPackageChange(packageName, changedState); |
| mWebViewUpdater.packageStateChanged(packageName, changedState); |
| } |
| |
| void prepareWebViewInSystemServer() { |
| updateFallbackStateOnBoot(); |
| mWebViewUpdater.prepareWebViewInSystemServer(); |
| mSystemInterface.notifyZygote(isMultiProcessEnabled()); |
| } |
| |
| private boolean existsValidNonFallbackProvider(WebViewProviderInfo[] providers) { |
| for (WebViewProviderInfo provider : providers) { |
| if (provider.availableByDefault && !provider.isFallback) { |
| // userPackages can contain null objects. |
| List<UserPackage> userPackages = |
| mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider); |
| if (isInstalledAndEnabledForAllUsers(userPackages) && |
| // Checking validity of the package for the system user (rather than all |
| // users) since package validity depends not on the user but on the package |
| // itself. |
| mWebViewUpdater.isValidProvider(provider, |
| userPackages.get(UserHandle.USER_SYSTEM).getPackageInfo())) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| void handleNewUser(int userId) { |
| handleUserChange(); |
| } |
| |
| void handleUserRemoved(int userId) { |
| handleUserChange(); |
| } |
| |
| /** |
| * Called when a user was added or removed to ensure fallback logic and WebView preparation are |
| * triggered. This has to be done since the WebView package we use depends on the enabled-state |
| * of packages for all users (so adding or removing a user might cause us to change package). |
| */ |
| private void handleUserChange() { |
| if (mSystemInterface.isFallbackLogicEnabled()) { |
| updateFallbackState(mSystemInterface.getWebViewPackages()); |
| } |
| // Potentially trigger package-changing logic. |
| mWebViewUpdater.updateCurrentWebViewPackage(null); |
| } |
| |
| void notifyRelroCreationCompleted() { |
| mWebViewUpdater.notifyRelroCreationCompleted(); |
| } |
| |
| WebViewProviderResponse waitForAndGetProvider() { |
| return mWebViewUpdater.waitForAndGetProvider(); |
| } |
| |
| String changeProviderAndSetting(String newProvider) { |
| return mWebViewUpdater.changeProviderAndSetting(newProvider); |
| } |
| |
| WebViewProviderInfo[] getValidWebViewPackages() { |
| return mWebViewUpdater.getValidWebViewPackages(); |
| } |
| |
| WebViewProviderInfo[] getWebViewPackages() { |
| return mSystemInterface.getWebViewPackages(); |
| } |
| |
| PackageInfo getCurrentWebViewPackage() { |
| return mWebViewUpdater.getCurrentWebViewPackage(); |
| } |
| |
| void enableFallbackLogic(boolean enable) { |
| mSystemInterface.enableFallbackLogic(enable); |
| } |
| |
| private void updateFallbackStateOnBoot() { |
| if (!mSystemInterface.isFallbackLogicEnabled()) return; |
| |
| WebViewProviderInfo[] webviewProviders = mSystemInterface.getWebViewPackages(); |
| updateFallbackState(webviewProviders); |
| } |
| |
| /** |
| * Handle the enabled-state of our fallback package, i.e. if there exists some non-fallback |
| * package that is valid (and available by default) then disable the fallback package, |
| * otherwise, enable the fallback package. |
| */ |
| private void updateFallbackStateOnPackageChange(String changedPackage, int changedState) { |
| if (!mSystemInterface.isFallbackLogicEnabled()) return; |
| |
| WebViewProviderInfo[] webviewProviders = mSystemInterface.getWebViewPackages(); |
| |
| // A package was changed / updated / downgraded, early out if it is not one of the |
| // webview packages that are available by default. |
| boolean changedPackageAvailableByDefault = false; |
| for (WebViewProviderInfo provider : webviewProviders) { |
| if (provider.packageName.equals(changedPackage)) { |
| if (provider.availableByDefault) { |
| changedPackageAvailableByDefault = true; |
| } |
| break; |
| } |
| } |
| if (!changedPackageAvailableByDefault) return; |
| updateFallbackState(webviewProviders); |
| } |
| |
| private void updateFallbackState(WebViewProviderInfo[] webviewProviders) { |
| // If there exists a valid and enabled non-fallback package - disable the fallback |
| // package, otherwise, enable it. |
| WebViewProviderInfo fallbackProvider = getFallbackProvider(webviewProviders); |
| if (fallbackProvider == null) return; |
| boolean existsValidNonFallbackProvider = existsValidNonFallbackProvider(webviewProviders); |
| |
| List<UserPackage> userPackages = |
| mSystemInterface.getPackageInfoForProviderAllUsers(mContext, fallbackProvider); |
| if (existsValidNonFallbackProvider && !isDisabledForAllUsers(userPackages)) { |
| mSystemInterface.uninstallAndDisablePackageForAllUsers(mContext, |
| fallbackProvider.packageName); |
| } else if (!existsValidNonFallbackProvider |
| && !isInstalledAndEnabledForAllUsers(userPackages)) { |
| // Enable the fallback package for all users. |
| mSystemInterface.enablePackageForAllUsers(mContext, |
| fallbackProvider.packageName, true); |
| } |
| } |
| |
| /** |
| * Returns the only fallback provider in the set of given packages, or null if there is none. |
| */ |
| private static WebViewProviderInfo getFallbackProvider(WebViewProviderInfo[] webviewPackages) { |
| for (WebViewProviderInfo provider : webviewPackages) { |
| if (provider.isFallback) { |
| return provider; |
| } |
| } |
| return null; |
| } |
| |
| boolean isFallbackPackage(String packageName) { |
| if (packageName == null || !mSystemInterface.isFallbackLogicEnabled()) return false; |
| |
| WebViewProviderInfo[] webviewPackages = mSystemInterface.getWebViewPackages(); |
| WebViewProviderInfo fallbackProvider = getFallbackProvider(webviewPackages); |
| return (fallbackProvider != null |
| && packageName.equals(fallbackProvider.packageName)); |
| } |
| |
| boolean isMultiProcessEnabled() { |
| PackageInfo current = getCurrentWebViewPackage(); |
| if (current == null) return false; |
| int currentVersion = current.versionCode; |
| int settingValue = mSystemInterface.getMultiProcessSetting(mContext); |
| if (mSystemInterface.isMultiProcessDefaultEnabled()) { |
| // Multiprocess should be enabled unless the user has turned it off manually for this |
| // version or newer, as we want to re-enable it when it's updated to get fresh |
| // bug reports. |
| return settingValue > -currentVersion; |
| } else { |
| // Multiprocess should not be enabled, unless the user has turned it on manually for |
| // any version. |
| return settingValue > 0; |
| } |
| } |
| |
| void enableMultiProcess(boolean enable) { |
| // The value we store for the setting is the version code of the current package, if it's |
| // enabled, or the negation of the version code of the current package, if it's disabled. |
| // Users who have a setting from before this scheme was implemented will have it set to 0 or |
| // 1 instead. |
| PackageInfo current = getCurrentWebViewPackage(); |
| int currentVersion = current != null ? current.versionCode : 1; |
| mSystemInterface.setMultiProcessSetting(mContext, |
| enable ? currentVersion : -currentVersion); |
| mSystemInterface.notifyZygote(enable); |
| if (current != null) { |
| mSystemInterface.killPackageDependents(current.packageName); |
| } |
| } |
| |
| /** |
| * Class that decides what WebView implementation to use and prepares that implementation for |
| * use. |
| */ |
| private static class WebViewUpdater { |
| private Context mContext; |
| private SystemInterface mSystemInterface; |
| private int mMinimumVersionCode = -1; |
| |
| public WebViewUpdater(Context context, SystemInterface systemInterface) { |
| mContext = context; |
| mSystemInterface = systemInterface; |
| } |
| |
| private static class WebViewPackageMissingException extends Exception { |
| public WebViewPackageMissingException(String message) { super(message); } |
| public WebViewPackageMissingException(Exception e) { super(e); } |
| } |
| |
| private static final int WAIT_TIMEOUT_MS = 1000; // KEY_DISPATCHING_TIMEOUT is 5000. |
| |
| // Keeps track of the number of running relro creations |
| private int mNumRelroCreationsStarted = 0; |
| private int mNumRelroCreationsFinished = 0; |
| // Implies that we need to rerun relro creation because we are using an out-of-date package |
| private boolean mWebViewPackageDirty = false; |
| private boolean mAnyWebViewInstalled = false; |
| |
| private int NUMBER_OF_RELROS_UNKNOWN = Integer.MAX_VALUE; |
| |
| // The WebView package currently in use (or the one we are preparing). |
| private PackageInfo mCurrentWebViewPackage = null; |
| |
| private Object mLock = new Object(); |
| |
| public void packageStateChanged(String packageName, int changedState) { |
| for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) { |
| String webviewPackage = provider.packageName; |
| |
| if (webviewPackage.equals(packageName)) { |
| boolean updateWebView = false; |
| boolean removedOrChangedOldPackage = false; |
| String oldProviderName = null; |
| PackageInfo newPackage = null; |
| synchronized(mLock) { |
| try { |
| newPackage = findPreferredWebViewPackage(); |
| if (mCurrentWebViewPackage != null) { |
| oldProviderName = mCurrentWebViewPackage.packageName; |
| if (changedState == WebViewUpdateService.PACKAGE_CHANGED |
| && newPackage.packageName.equals(oldProviderName)) { |
| // If we don't change package name we should only rerun the |
| // preparation phase if the current package has been replaced |
| // (not if it has been enabled/disabled). |
| return; |
| } |
| if (newPackage.packageName.equals(oldProviderName) |
| && (newPackage.lastUpdateTime |
| == mCurrentWebViewPackage.lastUpdateTime)) { |
| // If the chosen package hasn't been updated, then early-out |
| return; |
| } |
| } |
| // Only trigger update actions if the updated package is the one |
| // that will be used, or the one that was in use before the |
| // update, or if we haven't seen a valid WebView package before. |
| updateWebView = |
| provider.packageName.equals(newPackage.packageName) |
| || provider.packageName.equals(oldProviderName) |
| || mCurrentWebViewPackage == null; |
| // We removed the old package if we received an intent to remove |
| // or replace the old package. |
| removedOrChangedOldPackage = |
| provider.packageName.equals(oldProviderName); |
| if (updateWebView) { |
| onWebViewProviderChanged(newPackage); |
| } |
| } catch (WebViewPackageMissingException e) { |
| mCurrentWebViewPackage = null; |
| Slog.e(TAG, "Could not find valid WebView package to create " + |
| "relro with " + e); |
| } |
| } |
| if(updateWebView && !removedOrChangedOldPackage |
| && oldProviderName != null) { |
| // If the provider change is the result of adding or replacing a |
| // package that was not the previous provider then we must kill |
| // packages dependent on the old package ourselves. The framework |
| // only kills dependents of packages that are being removed. |
| mSystemInterface.killPackageDependents(oldProviderName); |
| } |
| return; |
| } |
| } |
| } |
| |
| public void prepareWebViewInSystemServer() { |
| try { |
| synchronized(mLock) { |
| mCurrentWebViewPackage = findPreferredWebViewPackage(); |
| // Don't persist the user-chosen setting across boots if the package being |
| // chosen is not used (could be disabled or uninstalled) so that the user won't |
| // be surprised by the device switching to using a certain webview package, |
| // that was uninstalled/disabled a long time ago, if it is installed/enabled |
| // again. |
| mSystemInterface.updateUserSetting(mContext, |
| mCurrentWebViewPackage.packageName); |
| onWebViewProviderChanged(mCurrentWebViewPackage); |
| } |
| } catch (Throwable t) { |
| // Log and discard errors at this stage as we must not crash the system server. |
| Slog.e(TAG, "error preparing webview provider from system server", t); |
| } |
| } |
| |
| /** |
| * Change WebView provider and provider setting and kill packages using the old provider. |
| * Return the new provider (in case we are in the middle of creating relro files, or |
| * replacing that provider it will not be in use directly, but will be used when the relros |
| * or the replacement are done). |
| */ |
| public String changeProviderAndSetting(String newProviderName) { |
| PackageInfo newPackage = updateCurrentWebViewPackage(newProviderName); |
| if (newPackage == null) return ""; |
| return newPackage.packageName; |
| } |
| |
| /** |
| * This is called when we change WebView provider, either when the current provider is |
| * updated or a new provider is chosen / takes precedence. |
| */ |
| private void onWebViewProviderChanged(PackageInfo newPackage) { |
| synchronized(mLock) { |
| mAnyWebViewInstalled = true; |
| if (mNumRelroCreationsStarted == mNumRelroCreationsFinished) { |
| mCurrentWebViewPackage = newPackage; |
| |
| // The relro creations might 'finish' (not start at all) before |
| // WebViewFactory.onWebViewProviderChanged which means we might not know the |
| // number of started creations before they finish. |
| mNumRelroCreationsStarted = NUMBER_OF_RELROS_UNKNOWN; |
| mNumRelroCreationsFinished = 0; |
| mNumRelroCreationsStarted = |
| mSystemInterface.onWebViewProviderChanged(newPackage); |
| // If the relro creations finish before we know the number of started creations |
| // we will have to do any cleanup/notifying here. |
| checkIfRelrosDoneLocked(); |
| } else { |
| mWebViewPackageDirty = true; |
| } |
| } |
| } |
| |
| private ProviderAndPackageInfo[] getValidWebViewPackagesAndInfos() { |
| WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages(); |
| List<ProviderAndPackageInfo> providers = new ArrayList<>(); |
| for(int n = 0; n < allProviders.length; n++) { |
| try { |
| PackageInfo packageInfo = |
| mSystemInterface.getPackageInfoForProvider(allProviders[n]); |
| if (isValidProvider(allProviders[n], packageInfo)) { |
| providers.add(new ProviderAndPackageInfo(allProviders[n], packageInfo)); |
| } |
| } catch (NameNotFoundException e) { |
| // Don't add non-existent packages |
| } |
| } |
| return providers.toArray(new ProviderAndPackageInfo[providers.size()]); |
| } |
| |
| /** |
| * Fetch only the currently valid WebView packages. |
| **/ |
| public WebViewProviderInfo[] getValidWebViewPackages() { |
| ProviderAndPackageInfo[] providersAndPackageInfos = getValidWebViewPackagesAndInfos(); |
| WebViewProviderInfo[] providers = |
| new WebViewProviderInfo[providersAndPackageInfos.length]; |
| for(int n = 0; n < providersAndPackageInfos.length; n++) { |
| providers[n] = providersAndPackageInfos[n].provider; |
| } |
| return providers; |
| } |
| |
| |
| private static class ProviderAndPackageInfo { |
| public final WebViewProviderInfo provider; |
| public final PackageInfo packageInfo; |
| |
| public ProviderAndPackageInfo(WebViewProviderInfo provider, PackageInfo packageInfo) { |
| this.provider = provider; |
| this.packageInfo = packageInfo; |
| } |
| } |
| |
| /** |
| * Returns either the package info of the WebView provider determined in the following way: |
| * If the user has chosen a provider then use that if it is valid, |
| * otherwise use the first package in the webview priority list that is valid. |
| * |
| */ |
| private PackageInfo findPreferredWebViewPackage() throws WebViewPackageMissingException { |
| ProviderAndPackageInfo[] providers = getValidWebViewPackagesAndInfos(); |
| |
| String userChosenProvider = mSystemInterface.getUserChosenWebViewProvider(mContext); |
| |
| // If the user has chosen provider, use that (if it's installed and enabled for all |
| // users). |
| for (ProviderAndPackageInfo providerAndPackage : providers) { |
| if (providerAndPackage.provider.packageName.equals(userChosenProvider)) { |
| // userPackages can contain null objects. |
| List<UserPackage> userPackages = |
| mSystemInterface.getPackageInfoForProviderAllUsers(mContext, |
| providerAndPackage.provider); |
| if (isInstalledAndEnabledForAllUsers(userPackages)) { |
| return providerAndPackage.packageInfo; |
| } |
| } |
| } |
| |
| // User did not choose, or the choice failed; use the most stable provider that is |
| // installed and enabled for all users, and available by default (not through |
| // user choice). |
| for (ProviderAndPackageInfo providerAndPackage : providers) { |
| if (providerAndPackage.provider.availableByDefault) { |
| // userPackages can contain null objects. |
| List<UserPackage> userPackages = |
| mSystemInterface.getPackageInfoForProviderAllUsers(mContext, |
| providerAndPackage.provider); |
| if (isInstalledAndEnabledForAllUsers(userPackages)) { |
| return providerAndPackage.packageInfo; |
| } |
| } |
| } |
| |
| // Could not find any installed and enabled package either, use the most stable and |
| // default-available provider. |
| // TODO(gsennton) remove this when we have a functional WebView stub. |
| for (ProviderAndPackageInfo providerAndPackage : providers) { |
| if (providerAndPackage.provider.availableByDefault) { |
| return providerAndPackage.packageInfo; |
| } |
| } |
| |
| // This should never happen during normal operation (only with modified system images). |
| mAnyWebViewInstalled = false; |
| throw new WebViewPackageMissingException("Could not find a loadable WebView package"); |
| } |
| |
| public void notifyRelroCreationCompleted() { |
| synchronized (mLock) { |
| mNumRelroCreationsFinished++; |
| checkIfRelrosDoneLocked(); |
| } |
| } |
| |
| public WebViewProviderResponse waitForAndGetProvider() { |
| PackageInfo webViewPackage = null; |
| final long NS_PER_MS = 1000000; |
| final long timeoutTimeMs = System.nanoTime() / NS_PER_MS + WAIT_TIMEOUT_MS; |
| boolean webViewReady = false; |
| int webViewStatus = WebViewFactory.LIBLOAD_SUCCESS; |
| synchronized (mLock) { |
| webViewReady = webViewIsReadyLocked(); |
| while (!webViewReady) { |
| final long timeNowMs = System.nanoTime() / NS_PER_MS; |
| if (timeNowMs >= timeoutTimeMs) break; |
| try { |
| mLock.wait(timeoutTimeMs - timeNowMs); |
| } catch (InterruptedException e) {} |
| webViewReady = webViewIsReadyLocked(); |
| } |
| // Make sure we return the provider that was used to create the relro file |
| webViewPackage = mCurrentWebViewPackage; |
| if (webViewReady) { |
| } else if (!mAnyWebViewInstalled) { |
| webViewStatus = WebViewFactory.LIBLOAD_FAILED_LISTING_WEBVIEW_PACKAGES; |
| } else { |
| // Either the current relro creation isn't done yet, or the new relro creatioin |
| // hasn't kicked off yet (the last relro creation used an out-of-date WebView). |
| webViewStatus = WebViewFactory.LIBLOAD_FAILED_WAITING_FOR_RELRO; |
| Slog.e(TAG, "Timed out waiting for relro creation, relros started " |
| + mNumRelroCreationsStarted |
| + " relros finished " + mNumRelroCreationsFinished |
| + " package dirty? " + mWebViewPackageDirty); |
| } |
| } |
| if (!webViewReady) Slog.w(TAG, "creating relro file timed out"); |
| return new WebViewProviderResponse(webViewPackage, webViewStatus); |
| } |
| |
| public PackageInfo getCurrentWebViewPackage() { |
| synchronized(mLock) { |
| return mCurrentWebViewPackage; |
| } |
| } |
| |
| /** |
| * Returns whether WebView is ready and is not going to go through its preparation phase |
| * again directly. |
| */ |
| private boolean webViewIsReadyLocked() { |
| return !mWebViewPackageDirty |
| && (mNumRelroCreationsStarted == mNumRelroCreationsFinished) |
| // The current package might be replaced though we haven't received an intent |
| // declaring this yet, the following flag makes anyone loading WebView to wait in |
| // this case. |
| && mAnyWebViewInstalled; |
| } |
| |
| private void checkIfRelrosDoneLocked() { |
| if (mNumRelroCreationsStarted == mNumRelroCreationsFinished) { |
| if (mWebViewPackageDirty) { |
| mWebViewPackageDirty = false; |
| // If we have changed provider since we started the relro creation we need to |
| // redo the whole process using the new package instead. |
| try { |
| PackageInfo newPackage = findPreferredWebViewPackage(); |
| onWebViewProviderChanged(newPackage); |
| } catch (WebViewPackageMissingException e) { |
| mCurrentWebViewPackage = null; |
| // If we can't find any valid WebView package we are now in a state where |
| // mAnyWebViewInstalled is false, so loading WebView will be blocked and we |
| // should simply wait until we receive an intent declaring a new package was |
| // installed. |
| } |
| } else { |
| mLock.notifyAll(); |
| } |
| } |
| } |
| |
| /** |
| * Both versionCodes should be from a WebView provider package implemented by Chromium. |
| * VersionCodes from other kinds of packages won't make any sense in this method. |
| * |
| * An introduction to Chromium versionCode scheme: |
| * "BBBBPPPAX" |
| * BBBB: 4 digit branch number. It monotonically increases over time. |
| * PPP: patch number in the branch. It is padded with zeroes to the left. These three digits |
| * may change their meaning in the future. |
| * A: architecture digit. |
| * X: A digit to differentiate APKs for other reasons. |
| * |
| * This method takes the "BBBB" of versionCodes and compare them. |
| * |
| * @return true if versionCode1 is higher than or equal to versionCode2. |
| */ |
| private static boolean versionCodeGE(int versionCode1, int versionCode2) { |
| int v1 = versionCode1 / 100000; |
| int v2 = versionCode2 / 100000; |
| |
| return v1 >= v2; |
| } |
| |
| /** |
| * Returns whether this provider is valid for use as a WebView provider. |
| */ |
| public boolean isValidProvider(WebViewProviderInfo configInfo, |
| PackageInfo packageInfo) { |
| // Ensure the provider targets this framework release (or a later one). |
| if (!UserPackage.hasCorrectTargetSdkVersion(packageInfo)) { |
| return false; |
| } |
| if (!versionCodeGE(packageInfo.versionCode, getMinimumVersionCode()) |
| && !mSystemInterface.systemIsDebuggable()) { |
| // Webview providers may be downgraded arbitrarily low, prevent that by enforcing |
| // minimum version code. This check is only enforced for user builds. |
| return false; |
| } |
| if (providerHasValidSignature(configInfo, packageInfo, mSystemInterface) && |
| WebViewFactory.getWebViewLibrary(packageInfo.applicationInfo) != null) { |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Gets the minimum version code allowed for a valid provider. It is the minimum versionCode |
| * of all available-by-default and non-fallback WebView provider packages. If there is no |
| * such WebView provider package on the system, then return -1, which means all positive |
| * versionCode WebView packages are accepted. |
| * |
| * Note that this is a private method in WebViewUpdater that handles a variable |
| * (mMinimumVersionCode) which is shared between threads. Furthermore, this method does not |
| * hold mLock meaning that we must take extra care to ensure this method is thread-safe. |
| */ |
| private int getMinimumVersionCode() { |
| if (mMinimumVersionCode > 0) { |
| return mMinimumVersionCode; |
| } |
| |
| int minimumVersionCode = -1; |
| for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) { |
| if (provider.availableByDefault && !provider.isFallback) { |
| try { |
| int versionCode = |
| mSystemInterface.getFactoryPackageVersion(provider.packageName); |
| if (minimumVersionCode < 0 || versionCode < minimumVersionCode) { |
| minimumVersionCode = versionCode; |
| } |
| } catch (NameNotFoundException e) { |
| // Safe to ignore. |
| } |
| } |
| } |
| |
| mMinimumVersionCode = minimumVersionCode; |
| return mMinimumVersionCode; |
| } |
| |
| public void dumpState(PrintWriter pw) { |
| synchronized (mLock) { |
| if (mCurrentWebViewPackage == null) { |
| pw.println(" Current WebView package is null"); |
| } else { |
| pw.println(String.format(" Current WebView package (name, version): (%s, %s)", |
| mCurrentWebViewPackage.packageName, |
| mCurrentWebViewPackage.versionName)); |
| } |
| pw.println(String.format(" Minimum WebView version code: %d", |
| mMinimumVersionCode)); |
| pw.println(String.format(" Number of relros started: %d", |
| mNumRelroCreationsStarted)); |
| pw.println(String.format(" Number of relros finished: %d", |
| mNumRelroCreationsFinished)); |
| pw.println(String.format(" WebView package dirty: %b", mWebViewPackageDirty)); |
| pw.println(String.format(" Any WebView package installed: %b", |
| mAnyWebViewInstalled)); |
| } |
| } |
| |
| /** |
| * Update the current WebView package. |
| * @param newProviderName the package to switch to, null if no package has been explicitly |
| * chosen. |
| */ |
| public PackageInfo updateCurrentWebViewPackage(String newProviderName) { |
| PackageInfo oldPackage = null; |
| PackageInfo newPackage = null; |
| boolean providerChanged = false; |
| synchronized(mLock) { |
| oldPackage = mCurrentWebViewPackage; |
| |
| if (newProviderName != null) { |
| mSystemInterface.updateUserSetting(mContext, newProviderName); |
| } |
| |
| try { |
| newPackage = findPreferredWebViewPackage(); |
| providerChanged = (oldPackage == null) |
| || !newPackage.packageName.equals(oldPackage.packageName); |
| } catch (WebViewPackageMissingException e) { |
| // If updated the Setting but don't have an installed WebView package, the |
| // Setting will be used when a package is available. |
| mCurrentWebViewPackage = null; |
| Slog.e(TAG, "Couldn't find WebView package to use " + e); |
| return null; |
| } |
| // Perform the provider change if we chose a new provider |
| if (providerChanged) { |
| onWebViewProviderChanged(newPackage); |
| } |
| } |
| // Kill apps using the old provider only if we changed provider |
| if (providerChanged && oldPackage != null) { |
| mSystemInterface.killPackageDependents(oldPackage.packageName); |
| } |
| // Return the new provider, this is not necessarily the one we were asked to switch to, |
| // but the persistent setting will now be pointing to the provider we were asked to |
| // switch to anyway. |
| return newPackage; |
| } |
| } |
| |
| private static boolean providerHasValidSignature(WebViewProviderInfo provider, |
| PackageInfo packageInfo, SystemInterface systemInterface) { |
| if (systemInterface.systemIsDebuggable()) { |
| return true; |
| } |
| Signature[] packageSignatures; |
| // If no signature is declared, instead check whether the package is included in the |
| // system. |
| if (provider.signatures == null || provider.signatures.length == 0) { |
| return packageInfo.applicationInfo.isSystemApp(); |
| } |
| packageSignatures = packageInfo.signatures; |
| if (packageSignatures.length != 1) |
| return false; |
| |
| final byte[] packageSignature = packageSignatures[0].toByteArray(); |
| // Return whether the package signature matches any of the valid signatures |
| for (String signature : provider.signatures) { |
| final byte[] validSignature = Base64.decode(signature, Base64.DEFAULT); |
| if (Arrays.equals(packageSignature, validSignature)) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Return true iff {@param packageInfos} point to only installed and enabled packages. |
| * The given packages {@param packageInfos} should all be pointing to the same package, but each |
| * PackageInfo representing a different user's package. |
| */ |
| private static boolean isInstalledAndEnabledForAllUsers( |
| List<UserPackage> userPackages) { |
| for (UserPackage userPackage : userPackages) { |
| if (!userPackage.isInstalledPackage() || !userPackage.isEnabledPackage()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private static boolean isDisabledForAllUsers(List<UserPackage> userPackages) { |
| for (UserPackage userPackage : userPackages) { |
| if (userPackage.getPackageInfo() != null && userPackage.isEnabledPackage()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Dump the state of this Service. |
| */ |
| void dumpState(PrintWriter pw) { |
| pw.println("Current WebView Update Service state"); |
| pw.println(String.format(" Fallback logic enabled: %b", |
| mSystemInterface.isFallbackLogicEnabled())); |
| mWebViewUpdater.dumpState(pw); |
| } |
| } |
