WebViewFactory.java revision 03c76e2b55e25fc22b8024124470e486b932c283
1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.webkit; 18 19import android.annotation.SystemApi; 20import android.app.ActivityManagerInternal; 21import android.app.AppGlobals; 22import android.app.Application; 23import android.content.Context; 24import android.content.pm.ApplicationInfo; 25import android.content.pm.PackageInfo; 26import android.content.pm.PackageManager; 27import android.os.Build; 28import android.os.Process; 29import android.os.RemoteException; 30import android.os.ServiceManager; 31import android.os.StrictMode; 32import android.os.SystemProperties; 33import android.os.Trace; 34import android.text.TextUtils; 35import android.util.AndroidRuntimeException; 36import android.util.Log; 37 38import com.android.server.LocalServices; 39 40import dalvik.system.VMRuntime; 41 42import java.io.File; 43import java.util.Arrays; 44 45/** 46 * Top level factory, used creating all the main WebView implementation classes. 47 * 48 * @hide 49 */ 50@SystemApi 51public final class WebViewFactory { 52 53 private static final String CHROMIUM_WEBVIEW_FACTORY = 54 "com.android.webview.chromium.WebViewChromiumFactoryProvider"; 55 56 private static final String NULL_WEBVIEW_FACTORY = 57 "com.android.webview.nullwebview.NullWebViewFactoryProvider"; 58 59 private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_32 = 60 "/data/misc/shared_relro/libwebviewchromium32.relro"; 61 private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_64 = 62 "/data/misc/shared_relro/libwebviewchromium64.relro"; 63 64 public static final String CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY = 65 "persist.sys.webview.vmsize"; 66 private static final long CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES = 100 * 1024 * 1024; 67 68 private static final String LOGTAG = "WebViewFactory"; 69 70 private static final boolean DEBUG = false; 71 72 // Cache the factory both for efficiency, and ensure any one process gets all webviews from the 73 // same provider. 74 private static WebViewFactoryProvider sProviderInstance; 75 private static final Object sProviderLock = new Object(); 76 private static boolean sAddressSpaceReserved = false; 77 private static PackageInfo sPackageInfo; 78 79 public static String getWebViewPackageName() { 80 return AppGlobals.getInitialApplication().getString( 81 com.android.internal.R.string.config_webViewPackageName); 82 } 83 84 public static PackageInfo getLoadedPackageInfo() { 85 return sPackageInfo; 86 } 87 88 static WebViewFactoryProvider getProvider() { 89 synchronized (sProviderLock) { 90 // For now the main purpose of this function (and the factory abstraction) is to keep 91 // us honest and minimize usage of WebView internals when binding the proxy. 92 if (sProviderInstance != null) return sProviderInstance; 93 94 final int uid = android.os.Process.myUid(); 95 if (uid == android.os.Process.ROOT_UID || uid == android.os.Process.SYSTEM_UID) { 96 throw new UnsupportedOperationException( 97 "For security reasons, WebView is not allowed in privileged processes"); 98 } 99 100 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.getProvider()"); 101 try { 102 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.loadNativeLibrary()"); 103 loadNativeLibrary(); 104 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 105 106 Class<WebViewFactoryProvider> providerClass; 107 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.getFactoryClass()"); 108 try { 109 providerClass = getFactoryClass(); 110 } catch (ClassNotFoundException e) { 111 Log.e(LOGTAG, "error loading provider", e); 112 throw new AndroidRuntimeException(e); 113 } finally { 114 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 115 } 116 117 StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads(); 118 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "providerClass.newInstance()"); 119 try { 120 sProviderInstance = providerClass.getConstructor(WebViewDelegate.class) 121 .newInstance(new WebViewDelegate()); 122 if (DEBUG) Log.v(LOGTAG, "Loaded provider: " + sProviderInstance); 123 return sProviderInstance; 124 } catch (Exception e) { 125 Log.e(LOGTAG, "error instantiating provider", e); 126 throw new AndroidRuntimeException(e); 127 } finally { 128 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 129 StrictMode.setThreadPolicy(oldPolicy); 130 } 131 } finally { 132 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 133 } 134 } 135 } 136 137 private static Class<WebViewFactoryProvider> getFactoryClass() throws ClassNotFoundException { 138 Application initialApplication = AppGlobals.getInitialApplication(); 139 try { 140 // First fetch the package info so we can log the webview package version. 141 String packageName = getWebViewPackageName(); 142 sPackageInfo = initialApplication.getPackageManager().getPackageInfo(packageName, 0); 143 Log.i(LOGTAG, "Loading " + packageName + " version " + sPackageInfo.versionName + 144 " (code " + sPackageInfo.versionCode + ")"); 145 146 // Construct a package context to load the Java code into the current app. 147 Context webViewContext = initialApplication.createPackageContext(packageName, 148 Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY); 149 initialApplication.getAssets().addAssetPath( 150 webViewContext.getApplicationInfo().sourceDir); 151 ClassLoader clazzLoader = webViewContext.getClassLoader(); 152 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "Class.forName()"); 153 try { 154 return (Class<WebViewFactoryProvider>) Class.forName(CHROMIUM_WEBVIEW_FACTORY, true, 155 clazzLoader); 156 } finally { 157 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 158 } 159 } catch (PackageManager.NameNotFoundException e) { 160 // If the package doesn't exist, then try loading the null WebView instead. 161 // If that succeeds, then this is a device without WebView support; if it fails then 162 // swallow the failure, complain that the real WebView is missing and rethrow the 163 // original exception. 164 try { 165 return (Class<WebViewFactoryProvider>) Class.forName(NULL_WEBVIEW_FACTORY); 166 } catch (ClassNotFoundException e2) { 167 // Ignore. 168 } 169 Log.e(LOGTAG, "Chromium WebView package does not exist", e); 170 throw new AndroidRuntimeException(e); 171 } 172 } 173 174 /** 175 * Perform any WebView loading preparations that must happen in the zygote. 176 * Currently, this means allocating address space to load the real JNI library later. 177 */ 178 public static void prepareWebViewInZygote() { 179 try { 180 System.loadLibrary("webviewchromium_loader"); 181 long addressSpaceToReserve = 182 SystemProperties.getLong(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY, 183 CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES); 184 sAddressSpaceReserved = nativeReserveAddressSpace(addressSpaceToReserve); 185 186 if (sAddressSpaceReserved) { 187 if (DEBUG) { 188 Log.v(LOGTAG, "address space reserved: " + addressSpaceToReserve + " bytes"); 189 } 190 } else { 191 Log.e(LOGTAG, "reserving " + addressSpaceToReserve + 192 " bytes of address space failed"); 193 } 194 } catch (Throwable t) { 195 // Log and discard errors at this stage as we must not crash the zygote. 196 Log.e(LOGTAG, "error preparing native loader", t); 197 } 198 } 199 200 /** 201 * Perform any WebView loading preparations that must happen at boot from the system server, 202 * after the package manager has started or after an update to the webview is installed. 203 * This must be called in the system server. 204 * Currently, this means spawning the child processes which will create the relro files. 205 */ 206 public static void prepareWebViewInSystemServer() { 207 String[] nativePaths = null; 208 try { 209 nativePaths = getWebViewNativeLibraryPaths(); 210 } catch (Throwable t) { 211 // Log and discard errors at this stage as we must not crash the system server. 212 Log.e(LOGTAG, "error preparing webview native library", t); 213 } 214 prepareWebViewInSystemServer(nativePaths); 215 } 216 217 private static void prepareWebViewInSystemServer(String[] nativeLibraryPaths) { 218 if (DEBUG) Log.v(LOGTAG, "creating relro files"); 219 220 // We must always trigger createRelRo regardless of the value of nativeLibraryPaths. Any 221 // unexpected values will be handled there to ensure that we trigger notifying any process 222 // waiting on relreo creation. 223 if (Build.SUPPORTED_32_BIT_ABIS.length > 0) { 224 if (DEBUG) Log.v(LOGTAG, "Create 32 bit relro"); 225 createRelroFile(false /* is64Bit */, nativeLibraryPaths); 226 } 227 228 if (Build.SUPPORTED_64_BIT_ABIS.length > 0) { 229 if (DEBUG) Log.v(LOGTAG, "Create 64 bit relro"); 230 createRelroFile(true /* is64Bit */, nativeLibraryPaths); 231 } 232 } 233 234 public static void onWebViewUpdateInstalled() { 235 String[] nativeLibs = null; 236 try { 237 nativeLibs = WebViewFactory.getWebViewNativeLibraryPaths(); 238 if (nativeLibs != null) { 239 long newVmSize = 0L; 240 241 for (String path : nativeLibs) { 242 if (DEBUG) Log.d(LOGTAG, "Checking file size of " + path); 243 if (path == null) continue; 244 File f = new File(path); 245 if (f.exists()) { 246 long length = f.length(); 247 if (length > newVmSize) { 248 newVmSize = length; 249 } 250 } 251 } 252 253 if (DEBUG) { 254 Log.v(LOGTAG, "Based on library size, need " + newVmSize + 255 " bytes of address space."); 256 } 257 // The required memory can be larger than the file on disk (due to .bss), and an 258 // upgraded version of the library will likely be larger, so always attempt to 259 // reserve twice as much as we think to allow for the library to grow during this 260 // boot cycle. 261 newVmSize = Math.max(2 * newVmSize, CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES); 262 Log.d(LOGTAG, "Setting new address space to " + newVmSize); 263 SystemProperties.set(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY, 264 Long.toString(newVmSize)); 265 } 266 } catch (Throwable t) { 267 // Log and discard errors at this stage as we must not crash the system server. 268 Log.e(LOGTAG, "error preparing webview native library", t); 269 } 270 prepareWebViewInSystemServer(nativeLibs); 271 } 272 273 private static String[] getWebViewNativeLibraryPaths() 274 throws PackageManager.NameNotFoundException { 275 final String NATIVE_LIB_FILE_NAME = "libwebviewchromium.so"; 276 277 PackageManager pm = AppGlobals.getInitialApplication().getPackageManager(); 278 ApplicationInfo ai = pm.getApplicationInfo(getWebViewPackageName(), 0); 279 280 String path32; 281 String path64; 282 boolean primaryArchIs64bit = VMRuntime.is64BitAbi(ai.primaryCpuAbi); 283 if (!TextUtils.isEmpty(ai.secondaryCpuAbi)) { 284 // Multi-arch case. 285 if (primaryArchIs64bit) { 286 // Primary arch: 64-bit, secondary: 32-bit. 287 path64 = ai.nativeLibraryDir; 288 path32 = ai.secondaryNativeLibraryDir; 289 } else { 290 // Primary arch: 32-bit, secondary: 64-bit. 291 path64 = ai.secondaryNativeLibraryDir; 292 path32 = ai.nativeLibraryDir; 293 } 294 } else if (primaryArchIs64bit) { 295 // Single-arch 64-bit. 296 path64 = ai.nativeLibraryDir; 297 path32 = ""; 298 } else { 299 // Single-arch 32-bit. 300 path32 = ai.nativeLibraryDir; 301 path64 = ""; 302 } 303 if (!TextUtils.isEmpty(path32)) path32 += "/" + NATIVE_LIB_FILE_NAME; 304 if (!TextUtils.isEmpty(path64)) path64 += "/" + NATIVE_LIB_FILE_NAME; 305 return new String[] { path32, path64 }; 306 } 307 308 private static void createRelroFile(final boolean is64Bit, String[] nativeLibraryPaths) { 309 final String abi = 310 is64Bit ? Build.SUPPORTED_64_BIT_ABIS[0] : Build.SUPPORTED_32_BIT_ABIS[0]; 311 312 // crashHandler is invoked by the ActivityManagerService when the isolated process crashes. 313 Runnable crashHandler = new Runnable() { 314 @Override 315 public void run() { 316 try { 317 Log.e(LOGTAG, "relro file creator for " + abi + " crashed. Proceeding without"); 318 getUpdateService().notifyRelroCreationCompleted(is64Bit, false); 319 } catch (RemoteException e) { 320 Log.e(LOGTAG, "Cannot reach WebViewUpdateService. " + e.getMessage()); 321 } 322 } 323 }; 324 325 try { 326 if (nativeLibraryPaths == null 327 || nativeLibraryPaths[0] == null || nativeLibraryPaths[1] == null) { 328 throw new IllegalArgumentException( 329 "Native library paths to the WebView RelRo process must not be null!"); 330 } 331 int pid = LocalServices.getService(ActivityManagerInternal.class).startIsolatedProcess( 332 RelroFileCreator.class.getName(), nativeLibraryPaths, "WebViewLoader-" + abi, abi, 333 Process.SHARED_RELRO_UID, crashHandler); 334 if (pid <= 0) throw new Exception("Failed to start the relro file creator process"); 335 } catch (Throwable t) { 336 // Log and discard errors as we must not crash the system server. 337 Log.e(LOGTAG, "error starting relro file creator for abi " + abi, t); 338 crashHandler.run(); 339 } 340 } 341 342 private static class RelroFileCreator { 343 // Called in an unprivileged child process to create the relro file. 344 public static void main(String[] args) { 345 boolean result = false; 346 boolean is64Bit = VMRuntime.getRuntime().is64Bit(); 347 try{ 348 if (args.length != 2 || args[0] == null || args[1] == null) { 349 Log.e(LOGTAG, "Invalid RelroFileCreator args: " + Arrays.toString(args)); 350 return; 351 } 352 Log.v(LOGTAG, "RelroFileCreator (64bit = " + is64Bit + "), " + 353 " 32-bit lib: " + args[0] + ", 64-bit lib: " + args[1]); 354 if (!sAddressSpaceReserved) { 355 Log.e(LOGTAG, "can't create relro file; address space not reserved"); 356 return; 357 } 358 result = nativeCreateRelroFile(args[0] /* path32 */, 359 args[1] /* path64 */, 360 CHROMIUM_WEBVIEW_NATIVE_RELRO_32, 361 CHROMIUM_WEBVIEW_NATIVE_RELRO_64); 362 if (result && DEBUG) Log.v(LOGTAG, "created relro file"); 363 } finally { 364 // We must do our best to always notify the update service, even if something fails. 365 try { 366 getUpdateService().notifyRelroCreationCompleted(is64Bit, result); 367 } catch (RemoteException e) { 368 Log.e(LOGTAG, "error notifying update service", e); 369 } 370 371 if (!result) Log.e(LOGTAG, "failed to create relro file"); 372 373 // Must explicitly exit or else this process will just sit around after we return. 374 System.exit(0); 375 } 376 } 377 } 378 379 private static void loadNativeLibrary() { 380 if (!sAddressSpaceReserved) { 381 Log.e(LOGTAG, "can't load with relro file; address space not reserved"); 382 return; 383 } 384 385 try { 386 getUpdateService().waitForRelroCreationCompleted(VMRuntime.getRuntime().is64Bit()); 387 } catch (RemoteException e) { 388 Log.e(LOGTAG, "error waiting for relro creation, proceeding without", e); 389 return; 390 } 391 392 try { 393 String[] args = getWebViewNativeLibraryPaths(); 394 boolean result = nativeLoadWithRelroFile(args[0] /* path32 */, 395 args[1] /* path64 */, 396 CHROMIUM_WEBVIEW_NATIVE_RELRO_32, 397 CHROMIUM_WEBVIEW_NATIVE_RELRO_64); 398 if (!result) { 399 Log.w(LOGTAG, "failed to load with relro file, proceeding without"); 400 } else if (DEBUG) { 401 Log.v(LOGTAG, "loaded with relro file"); 402 } 403 } catch (PackageManager.NameNotFoundException e) { 404 Log.e(LOGTAG, "Failed to list WebView package libraries for loadNativeLibrary", e); 405 } 406 } 407 408 private static IWebViewUpdateService getUpdateService() { 409 return IWebViewUpdateService.Stub.asInterface(ServiceManager.getService("webviewupdate")); 410 } 411 412 private static native boolean nativeReserveAddressSpace(long addressSpaceToReserve); 413 private static native boolean nativeCreateRelroFile(String lib32, String lib64, 414 String relro32, String relro64); 415 private static native boolean nativeLoadWithRelroFile(String lib32, String lib64, 416 String relro32, String relro64); 417} 418