| /* |
| * Copyright (C) 2017 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.PackageInfo; |
| import android.content.pm.PackageManager.NameNotFoundException; |
| import android.content.pm.Signature; |
| import android.os.UserHandle; |
| 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.List; |
| |
| /** |
| * Class that decides what WebView implementation to use and prepares that implementation for |
| * use. |
| */ |
| class WebViewUpdater { |
| private static final String TAG = WebViewUpdater.class.getSimpleName(); |
| |
| 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. |
| |
| private final static int VALIDITY_OK = 0; |
| private final static int VALIDITY_INCORRECT_SDK_VERSION = 1; |
| private final static int VALIDITY_INCORRECT_VERSION_CODE = 2; |
| private final static int VALIDITY_INCORRECT_SIGNATURE = 3; |
| private final static int VALIDITY_NO_LIBRARY_FLAG = 4; |
| |
| private Context mContext; |
| private SystemInterface mSystemInterface; |
| private long mMinimumVersionCode = -1; |
| |
| // 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| // Implies that we need to rerun relro creation because we are using an out-of-date package |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 final Object mLock = new Object(); |
| |
| WebViewUpdater(Context context, SystemInterface systemInterface) { |
| mContext = context; |
| mSystemInterface = systemInterface; |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| void prepareWebViewInSystemServer() { |
| try { |
| synchronized(mLock) { |
| mCurrentWebViewPackage = findPreferredWebViewPackage(); |
| String userSetting = mSystemInterface.getUserChosenWebViewProvider(mContext); |
| if (userSetting != null |
| && !userSetting.equals(mCurrentWebViewPackage.packageName)) { |
| // 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). |
| */ |
| String changeProviderAndSetting(String newProviderName) { |
| PackageInfo newPackage = updateCurrentWebViewPackage(newProviderName); |
| if (newPackage == null) return ""; |
| return newPackage.packageName; |
| } |
| |
| /** |
| * Update the current WebView package. |
| * @param newProviderName the package to switch to, null if no package has been explicitly |
| * chosen. |
| */ |
| 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; |
| } |
| |
| /** |
| * 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; |
| } |
| } |
| } |
| |
| /** |
| * Fetch only the currently valid WebView packages. |
| **/ |
| 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; |
| } |
| } |
| |
| 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()]); |
| } |
| |
| /** |
| * 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; |
| } |
| } |
| } |
| |
| // This should never happen during normal operation (only with modified system images). |
| mAnyWebViewInstalled = false; |
| throw new WebViewPackageMissingException("Could not find a loadable WebView package"); |
| } |
| |
| /** |
| * 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. |
| */ |
| static boolean isInstalledAndEnabledForAllUsers( |
| List<UserPackage> userPackages) { |
| for (UserPackage userPackage : userPackages) { |
| if (!userPackage.isInstalledPackage() || !userPackage.isEnabledPackage()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void notifyRelroCreationCompleted() { |
| synchronized (mLock) { |
| mNumRelroCreationsFinished++; |
| checkIfRelrosDoneLocked(); |
| } |
| } |
| |
| 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); |
| } |
| |
| 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(); |
| } |
| } |
| } |
| |
| /** |
| * Returns whether this provider is valid for use as a WebView provider. |
| */ |
| boolean isValidProvider(WebViewProviderInfo configInfo, PackageInfo packageInfo) { |
| return VALIDITY_OK == validityResult(configInfo, packageInfo); |
| } |
| |
| private int validityResult(WebViewProviderInfo configInfo, PackageInfo packageInfo) { |
| // Ensure the provider targets this framework release (or a later one). |
| if (!UserPackage.hasCorrectTargetSdkVersion(packageInfo)) { |
| return VALIDITY_INCORRECT_SDK_VERSION; |
| } |
| if (!versionCodeGE(packageInfo.getLongVersionCode(), 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 VALIDITY_INCORRECT_VERSION_CODE; |
| } |
| if (!providerHasValidSignature(configInfo, packageInfo, mSystemInterface)) { |
| return VALIDITY_INCORRECT_SIGNATURE; |
| } |
| if (WebViewFactory.getWebViewLibrary(packageInfo.applicationInfo) == null) { |
| return VALIDITY_NO_LIBRARY_FLAG; |
| } |
| return VALIDITY_OK; |
| } |
| |
| /** |
| * 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(long versionCode1, long versionCode2) { |
| long v1 = versionCode1 / 100000; |
| long v2 = versionCode2 / 100000; |
| |
| return v1 >= v2; |
| } |
| |
| /** |
| * Gets the minimum version code allowed for a valid provider. It is the minimum versionCode |
| * of all available-by-default 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 long getMinimumVersionCode() { |
| if (mMinimumVersionCode > 0) { |
| return mMinimumVersionCode; |
| } |
| |
| long minimumVersionCode = -1; |
| for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) { |
| if (provider.availableByDefault) { |
| try { |
| long versionCode = |
| mSystemInterface.getFactoryPackageVersion(provider.packageName); |
| if (minimumVersionCode < 0 || versionCode < minimumVersionCode) { |
| minimumVersionCode = versionCode; |
| } |
| } catch (NameNotFoundException e) { |
| // Safe to ignore. |
| } |
| } |
| } |
| |
| mMinimumVersionCode = minimumVersionCode; |
| return mMinimumVersionCode; |
| } |
| |
| private static boolean providerHasValidSignature(WebViewProviderInfo provider, |
| PackageInfo packageInfo, SystemInterface systemInterface) { |
| // Skip checking signatures on debuggable builds, for development purposes. |
| if (systemInterface.systemIsDebuggable()) return true; |
| |
| // Allow system apps to be valid providers regardless of signature. |
| if (packageInfo.applicationInfo.isSystemApp()) return true; |
| |
| // We don't support packages with multiple signatures. |
| if (packageInfo.signatures.length != 1) return false; |
| |
| // If any of the declared signatures match the package signature, it's valid. |
| for (Signature signature : provider.signatures) { |
| if (signature.equals(packageInfo.signatures[0])) return true; |
| } |
| |
| return false; |
| } |
| |
| 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 targetSdkVersion: %d", |
| UserPackage.MINIMUM_SUPPORTED_SDK)); |
| 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)); |
| |
| try { |
| PackageInfo preferredWebViewPackage = findPreferredWebViewPackage(); |
| pw.println(String.format( |
| " Preferred WebView package (name, version): (%s, %s)", |
| preferredWebViewPackage.packageName, |
| preferredWebViewPackage.versionName)); |
| } catch (WebViewPackageMissingException e) { |
| pw.println(String.format(" Preferred WebView package: none")); |
| } |
| |
| dumpAllPackageInformationLocked(pw); |
| } |
| } |
| |
| private void dumpAllPackageInformationLocked(PrintWriter pw) { |
| WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages(); |
| pw.println(" WebView packages:"); |
| for (WebViewProviderInfo provider : allProviders) { |
| List<UserPackage> userPackages = |
| mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider); |
| PackageInfo systemUserPackageInfo = |
| userPackages.get(UserHandle.USER_SYSTEM).getPackageInfo(); |
| if (systemUserPackageInfo == null) { |
| pw.println(String.format(" %s is NOT installed.", provider.packageName)); |
| continue; |
| } |
| |
| int validity = validityResult(provider, systemUserPackageInfo); |
| String packageDetails = String.format( |
| "versionName: %s, versionCode: %d, targetSdkVersion: %d", |
| systemUserPackageInfo.versionName, |
| systemUserPackageInfo.getLongVersionCode(), |
| systemUserPackageInfo.applicationInfo.targetSdkVersion); |
| if (validity == VALIDITY_OK) { |
| boolean installedForAllUsers = isInstalledAndEnabledForAllUsers( |
| mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider)); |
| pw.println(String.format( |
| " Valid package %s (%s) is %s installed/enabled for all users", |
| systemUserPackageInfo.packageName, |
| packageDetails, |
| installedForAllUsers ? "" : "NOT")); |
| } else { |
| pw.println(String.format(" Invalid package %s (%s), reason: %s", |
| systemUserPackageInfo.packageName, |
| packageDetails, |
| getInvalidityReason(validity))); |
| } |
| } |
| } |
| |
| private static String getInvalidityReason(int invalidityReason) { |
| switch (invalidityReason) { |
| case VALIDITY_INCORRECT_SDK_VERSION: |
| return "SDK version too low"; |
| case VALIDITY_INCORRECT_VERSION_CODE: |
| return "Version code too low"; |
| case VALIDITY_INCORRECT_SIGNATURE: |
| return "Incorrect signature"; |
| case VALIDITY_NO_LIBRARY_FLAG: |
| return "No WebView-library manifest flag"; |
| default: |
| return "Unexcepted validity-reason"; |
| } |
| } |
| |
| } |