/*
* Copyright (C) 2012 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 android.webkit;
import android.annotation.SystemApi;
import android.app.ActivityManagerInternal;
import android.app.AppGlobals;
import android.app.Application;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Process;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.StrictMode;
import android.os.SystemProperties;
import android.os.Trace;
import android.text.TextUtils;
import android.util.AndroidRuntimeException;
import android.util.Log;
import com.android.server.LocalServices;
import dalvik.system.VMRuntime;
import java.io.File;
import java.util.Arrays;
/**
* Top level factory, used creating all the main WebView implementation classes.
*
* @hide
*/
@SystemApi
public final class WebViewFactory {
private static final String CHROMIUM_WEBVIEW_FACTORY =
"com.android.webview.chromium.WebViewChromiumFactoryProvider";
private static final String NULL_WEBVIEW_FACTORY =
"com.android.webview.nullwebview.NullWebViewFactoryProvider";
private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_32 =
"/data/misc/shared_relro/libwebviewchromium32.relro";
private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_64 =
"/data/misc/shared_relro/libwebviewchromium64.relro";
public static final String CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY =
"persist.sys.webview.vmsize";
private static final long CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES = 100 * 1024 * 1024;
private static final String LOGTAG = "WebViewFactory";
private static final boolean DEBUG = false;
// Cache the factory both for efficiency, and ensure any one process gets all webviews from the
// same provider.
private static WebViewFactoryProvider sProviderInstance;
private static final Object sProviderLock = new Object();
private static boolean sAddressSpaceReserved = false;
private static PackageInfo sPackageInfo;
public static String getWebViewPackageName() {
return AppGlobals.getInitialApplication().getString(
com.android.internal.R.string.config_webViewPackageName);
}
public static PackageInfo getLoadedPackageInfo() {
return sPackageInfo;
}
static WebViewFactoryProvider getProvider() {
synchronized (sProviderLock) {
// For now the main purpose of this function (and the factory abstraction) is to keep
// us honest and minimize usage of WebView internals when binding the proxy.
if (sProviderInstance != null) return sProviderInstance;
final int uid = android.os.Process.myUid();
if (uid == android.os.Process.ROOT_UID || uid == android.os.Process.SYSTEM_UID) {
throw new UnsupportedOperationException(
"For security reasons, WebView is not allowed in privileged processes");
}
Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.getProvider()");
try {
Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.loadNativeLibrary()");
loadNativeLibrary();
Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW);
Class<WebViewFactoryProvider> providerClass;
Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.getFactoryClass()");
try {
providerClass = getFactoryClass();
} catch (ClassNotFoundException e) {
Log.e(LOGTAG, "error loading provider", e);
throw new AndroidRuntimeException(e);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW);
}
StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "providerClass.newInstance()");
try {
try {
sProviderInstance = providerClass.getConstructor(WebViewDelegate.class)
.newInstance(new WebViewDelegate());
} catch (Exception e) {
sProviderInstance = providerClass.newInstance();
}
if (DEBUG) Log.v(LOGTAG, "Loaded provider: " + sProviderInstance);
return sProviderInstance;
} catch (Exception e) {
Log.e(LOGTAG, "error instantiating provider", e);
throw new AndroidRuntimeException(e);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW);
StrictMode.setThreadPolicy(oldPolicy);
}
} finally {
Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW);
}
}
}
private static Class<WebViewFactoryProvider> getFactoryClass() throws ClassNotFoundException {
Application initialApplication = AppGlobals.getInitialApplication();
try {
// First fetch the package info so we can log the webview package version.
String packageName = getWebViewPackageName();
sPackageInfo = initialApplication.getPackageManager().getPackageInfo(packageName, 0);
Log.i(LOGTAG, "Loading " + packageName + " version " + sPackageInfo.versionName +
" (code " + sPackageInfo.versionCode + ")");
// Construct a package context to load the Java code into the current app.
Context webViewContext = initialApplication.createPackageContext(packageName,
Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY);
initialApplication.getAssets().addAssetPath(
webViewContext.getApplicationInfo().sourceDir);
ClassLoader clazzLoader = webViewContext.getClassLoader();
Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "Class.forName()");
try {
return (Class<WebViewFactoryProvider>) Class.forName(CHROMIUM_WEBVIEW_FACTORY, true,
clazzLoader);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW);
}
} catch (PackageManager.NameNotFoundException e) {
// If the package doesn't exist, then try loading the null WebView instead.
// If that succeeds, then this is a device without WebView support; if it fails then
// swallow the failure, complain that the real WebView is missing and rethrow the
// original exception.
try {
return (Class<WebViewFactoryProvider>) Class.forName(NULL_WEBVIEW_FACTORY);
} catch (ClassNotFoundException e2) {
// Ignore.
}
Log.e(LOGTAG, "Chromium WebView package does not exist", e);
throw new AndroidRuntimeException(e);
}
}
/**
* Perform any WebView loading preparations that must happen in the zygote.
* Currently, this means allocating address space to load the real JNI library later.
*/
public static void prepareWebViewInZygote() {
try {
System.loadLibrary("webviewchromium_loader");
long addressSpaceToReserve =
SystemProperties.getLong(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY,
CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES);
sAddressSpaceReserved = nativeReserveAddressSpace(addressSpaceToReserve);
if (sAddressSpaceReserved) {
if (DEBUG) {
Log.v(LOGTAG, "address space reserved: " + addressSpaceToReserve + " bytes");
}
} else {
Log.e(LOGTAG, "reserving " + addressSpaceToReserve +
" bytes of address space failed");
}
} catch (Throwable t) {
// Log and discard errors at this stage as we must not crash the zygote.
Log.e(LOGTAG, "error preparing native loader", t);
}
}
/**
* Perform any WebView loading preparations that must happen at boot from the system server,
* after the package manager has started or after an update to the webview is installed.
* This must be called in the system server.
* Currently, this means spawning the child processes which will create the relro files.
*/
public static void prepareWebViewInSystemServer() {
String[] nativePaths = null;
try {
nativePaths = getWebViewNativeLibraryPaths();
} catch (Throwable t) {
// Log and discard errors at this stage as we must not crash the system server.
Log.e(LOGTAG, "error preparing webview native library", t);
}
prepareWebViewInSystemServer(nativePaths);
}
private static void prepareWebViewInSystemServer(String[] nativeLibraryPaths) {
if (DEBUG) Log.v(LOGTAG, "creating relro files");
// We must always trigger createRelRo regardless of the value of nativeLibraryPaths. Any
// unexpected values will be handled there to ensure that we trigger notifying any process
// waiting on relreo creation.
if (Build.SUPPORTED_32_BIT_ABIS.length > 0) {
if (DEBUG) Log.v(LOGTAG, "Create 32 bit relro");
createRelroFile(false /* is64Bit */, nativeLibraryPaths);
}
if (Build.SUPPORTED_64_BIT_ABIS.length > 0) {
if (DEBUG) Log.v(LOGTAG, "Create 64 bit relro");
createRelroFile(true /* is64Bit */, nativeLibraryPaths);
}
}
public static void onWebViewUpdateInstalled() {
String[] nativeLibs = null;
try {
nativeLibs = WebViewFactory.getWebViewNativeLibraryPaths();
if (nativeLibs != null) {
long newVmSize = 0L;
for (String path : nativeLibs) {
if (DEBUG) Log.d(LOGTAG, "Checking file size of " + path);
if (path == null) continue;
File f = new File(path);
if (f.exists()) {
long length = f.length();
if (length > newVmSize) {
newVmSize = length;
}
}
}
if (DEBUG) {
Log.v(LOGTAG, "Based on library size, need " + newVmSize +
" bytes of address space.");
}
// The required memory can be larger than the file on disk (due to .bss), and an
// upgraded version of the library will likely be larger, so always attempt to
// reserve twice as much as we think to allow for the library to grow during this
// boot cycle.
newVmSize = Math.max(2 * newVmSize, CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES);
Log.d(LOGTAG, "Setting new address space to " + newVmSize);
SystemProperties.set(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY,
Long.toString(newVmSize));
}
} catch (Throwable t) {
// Log and discard errors at this stage as we must not crash the system server.
Log.e(LOGTAG, "error preparing webview native library", t);
}
prepareWebViewInSystemServer(nativeLibs);
}
private static String[] getWebViewNativeLibraryPaths()
throws PackageManager.NameNotFoundException {
final String NATIVE_LIB_FILE_NAME = "libwebviewchromium.so";
PackageManager pm = AppGlobals.getInitialApplication().getPackageManager();
ApplicationInfo ai = pm.getApplicationInfo(getWebViewPackageName(), 0);
String path32;
String path64;
boolean primaryArchIs64bit = VMRuntime.is64BitAbi(ai.primaryCpuAbi);
if (!TextUtils.isEmpty(ai.secondaryCpuAbi)) {
// Multi-arch case.
if (primaryArchIs64bit) {
// Primary arch: 64-bit, secondary: 32-bit.
path64 = ai.nativeLibraryDir;
path32 = ai.secondaryNativeLibraryDir;
} else {
// Primary arch: 32-bit, secondary: 64-bit.
path64 = ai.secondaryNativeLibraryDir;
path32 = ai.nativeLibraryDir;
}
} else if (primaryArchIs64bit) {
// Single-arch 64-bit.
path64 = ai.nativeLibraryDir;
path32 = "";
} else {
// Single-arch 32-bit.
path32 = ai.nativeLibraryDir;
path64 = "";
}
if (!TextUtils.isEmpty(path32)) path32 += "/" + NATIVE_LIB_FILE_NAME;
if (!TextUtils.isEmpty(path64)) path64 += "/" + NATIVE_LIB_FILE_NAME;
return new String[] { path32, path64 };
}
private static void createRelroFile(final boolean is64Bit, String[] nativeLibraryPaths) {
final String abi =
is64Bit ? Build.SUPPORTED_64_BIT_ABIS[0] : Build.SUPPORTED_32_BIT_ABIS[0];
// crashHandler is invoked by the ActivityManagerService when the isolated process crashes.
Runnable crashHandler = new Runnable() {
@Override
public void run() {
try {
Log.e(LOGTAG, "relro file creator for " + abi + " crashed. Proceeding without");
getUpdateService().notifyRelroCreationCompleted(is64Bit, false);
} catch (RemoteException e) {
Log.e(LOGTAG, "Cannot reach WebViewUpdateService. " + e.getMessage());
}
}
};
try {
if (nativeLibraryPaths == null
|| nativeLibraryPaths[0] == null || nativeLibraryPaths[1] == null) {
throw new IllegalArgumentException(
"Native library paths to the WebView RelRo process must not be null!");
}
int pid = LocalServices.getService(ActivityManagerInternal.class).startIsolatedProcess(
RelroFileCreator.class.getName(), nativeLibraryPaths, "WebViewLoader-" + abi, abi,
Process.SHARED_RELRO_UID, crashHandler);
if (pid <= 0) throw new Exception("Failed to start the relro file creator process");
} catch (Throwable t) {
// Log and discard errors as we must not crash the system server.
Log.e(LOGTAG, "error starting relro file creator for abi " + abi, t);
crashHandler.run();
}
}
private static class RelroFileCreator {
// Called in an unprivileged child process to create the relro file.
public static void main(String[] args) {
boolean result = false;
boolean is64Bit = VMRuntime.getRuntime().is64Bit();
try{
if (args.length != 2 || args[0] == null || args[1] == null) {
Log.e(LOGTAG, "Invalid RelroFileCreator args: " + Arrays.toString(args));
return;
}
Log.v(LOGTAG, "RelroFileCreator (64bit = " + is64Bit + "), " +
" 32-bit lib: " + args[0] + ", 64-bit lib: " + args[1]);
if (!sAddressSpaceReserved) {
Log.e(LOGTAG, "can't create relro file; address space not reserved");
return;
}
result = nativeCreateRelroFile(args[0] /* path32 */,
args[1] /* path64 */,
CHROMIUM_WEBVIEW_NATIVE_RELRO_32,
CHROMIUM_WEBVIEW_NATIVE_RELRO_64);
if (result && DEBUG) Log.v(LOGTAG, "created relro file");
} finally {
// We must do our best to always notify the update service, even if something fails.
try {
getUpdateService().notifyRelroCreationCompleted(is64Bit, result);
} catch (RemoteException e) {
Log.e(LOGTAG, "error notifying update service", e);
}
if (!result) Log.e(LOGTAG, "failed to create relro file");
// Must explicitly exit or else this process will just sit around after we return.
System.exit(0);
}
}
}
private static void loadNativeLibrary() {
if (!sAddressSpaceReserved) {
Log.e(LOGTAG, "can't load with relro file; address space not reserved");
return;
}
try {
getUpdateService().waitForRelroCreationCompleted(VMRuntime.getRuntime().is64Bit());
} catch (RemoteException e) {
Log.e(LOGTAG, "error waiting for relro creation, proceeding without", e);
return;
}
try {
String[] args = getWebViewNativeLibraryPaths();
boolean result = nativeLoadWithRelroFile(args[0] /* path32 */,
args[1] /* path64 */,
CHROMIUM_WEBVIEW_NATIVE_RELRO_32,
CHROMIUM_WEBVIEW_NATIVE_RELRO_64);
if (!result) {
Log.w(LOGTAG, "failed to load with relro file, proceeding without");
} else if (DEBUG) {
Log.v(LOGTAG, "loaded with relro file");
}
} catch (PackageManager.NameNotFoundException e) {
Log.e(LOGTAG, "Failed to list WebView package libraries for loadNativeLibrary", e);
}
}
private static IWebViewUpdateService getUpdateService() {
return IWebViewUpdateService.Stub.asInterface(ServiceManager.getService("webviewupdate"));
}
private static native boolean nativeReserveAddressSpace(long addressSpaceToReserve);
private static native boolean nativeCreateRelroFile(String lib32, String lib64,
String relro32, String relro64);
private static native boolean nativeLoadWithRelroFile(String lib32, String lib64,
String relro32, String relro64);
}