1 /* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.nashorn.internal.runtime.linker; 27 28 import static jdk.nashorn.internal.lookup.Lookup.MH; 29 30 import java.lang.invoke.MethodHandle; 31 import java.lang.invoke.MethodHandles; 32 import java.lang.invoke.MethodHandles.Lookup; 33 import java.lang.invoke.MethodType; 34 import java.lang.reflect.Modifier; 35 import java.security.AccessControlContext; 36 import java.security.AccessController; 37 import java.security.CodeSigner; 38 import java.security.CodeSource; 39 import java.security.Permissions; 40 import java.security.PrivilegedAction; 41 import java.security.ProtectionDomain; 42 import java.util.ArrayList; 43 import java.util.Arrays; 44 import java.util.Collections; 45 import java.util.HashMap; 46 import java.util.List; 47 import java.util.Map; 48 import java.util.concurrent.ConcurrentHashMap; 49 import jdk.internal.dynalink.beans.StaticClass; 50 import jdk.internal.dynalink.support.LinkRequestImpl; 51 import jdk.nashorn.internal.objects.NativeJava; 52 import jdk.nashorn.internal.runtime.Context; 53 import jdk.nashorn.internal.runtime.ECMAException; 54 import jdk.nashorn.internal.runtime.ScriptFunction; 55 import jdk.nashorn.internal.runtime.ScriptObject; 56 57 /** 58 * <p>A factory class that generates adapter classes. Adapter classes allow implementation of Java interfaces and 59 * extending of Java classes from JavaScript. For every combination of a superclass to extend and interfaces to 60 * implement (collectively: "original types"), exactly one adapter class is generated that extends the specified 61 * superclass and implements the specified interfaces. (But see the discussion of class-based overrides for exceptions.) 62 * </p><p> 63 * The adapter class is generated in a new secure class loader that inherits Nashorn's protection domain, and has either 64 * one of the original types' class loader or the Nashorn's class loader as its parent - the parent class loader 65 * is chosen so that all the original types and the Nashorn core classes are visible from it (as the adapter will have 66 * constant pool references to ScriptObject and ScriptFunction classes). In case none of the candidate class loaders has 67 * visibility of all the required types, an error is thrown. The class uses {@link JavaAdapterBytecodeGenerator} to 68 * generate the adapter class itself; see its documentation for details about the generated class. 69 * </p><p> 70 * You normally don't use this class directly, but rather either create adapters from script using 71 * {@link NativeJava#extend(Object, Object...)}, using the {@code new} operator on abstract classes and interfaces (see 72 * {@link NativeJava#type(Object, Object)}), or implicitly when passing script functions to Java methods expecting SAM 73 * types. 74 * </p> 75 */ 76 77 @SuppressWarnings("javadoc") 78 public final class JavaAdapterFactory { 79 private static final ProtectionDomain MINIMAL_PERMISSION_DOMAIN = createMinimalPermissionDomain(); 80 81 // context with permissions needs for AdapterInfo creation 82 private static final AccessControlContext CREATE_ADAPTER_INFO_ACC_CTXT = 83 ClassAndLoader.createPermAccCtxt("createClassLoader", "getClassLoader", 84 "accessDeclaredMembers", "accessClassInPackage.jdk.nashorn.internal.runtime"); 85 86 /** 87 * A mapping from an original Class object to AdapterInfo representing the adapter for the class it represents. 88 */ 89 private static final ClassValue<Map<List<Class<?>>, AdapterInfo>> ADAPTER_INFO_MAPS = new ClassValue<Map<List<Class<?>>, AdapterInfo>>() { 90 @Override 91 protected Map<List<Class<?>>, AdapterInfo> computeValue(final Class<?> type) { 92 return new HashMap<>(); 93 } 94 }; 95 96 /** 97 * Returns an adapter class for the specified original types. The adapter class extends/implements the original 98 * class/interfaces. 99 * @param types the original types. The caller must pass at least one Java type representing either a public 100 * interface or a non-final public class with at least one public or protected constructor. If more than one type is 101 * specified, at most one can be a class and the rest have to be interfaces. The class can be in any position in the 102 * array. Invoking the method twice with exactly the same types in the same order will return the same adapter 103 * class, any reordering of types or even addition or removal of redundant types (i.e. interfaces that other types 104 * in the list already implement/extend, or {@code java.lang.Object} in a list of types consisting purely of 105 * interfaces) will result in a different adapter class, even though those adapter classes are functionally 106 * identical; we deliberately don't want to incur the additional processing cost of canonicalizing type lists. 107 * @param classOverrides a JavaScript object with functions serving as the class-level overrides and 108 * implementations. These overrides are defined for all instances of the class, and can be further overridden on a 109 * per-instance basis by passing additional objects in the constructor. 110 * @param lookup the lookup object identifying the caller class. The generated adapter class will have the 111 * protection domain of the caller class iff the lookup object is full-strength, otherwise it will be completely 112 * unprivileged. 113 * @return an adapter class. See this class' documentation for details on the generated adapter class. 114 * @throws ECMAException with a TypeError if the adapter class can not be generated because the original class is 115 * final, non-public, or has no public or protected constructors. 116 */ 117 public static StaticClass getAdapterClassFor(final Class<?>[] types, ScriptObject classOverrides, final MethodHandles.Lookup lookup) { 118 return getAdapterClassFor(types, classOverrides, getProtectionDomain(lookup)); 119 } 120 121 private static StaticClass getAdapterClassFor(final Class<?>[] types, ScriptObject classOverrides, final ProtectionDomain protectionDomain) { 122 assert types != null && types.length > 0; 123 final SecurityManager sm = System.getSecurityManager(); 124 if (sm != null) { 125 for (Class<?> type : types) { 126 // check for restricted package access 127 Context.checkPackageAccess(type); 128 // check for classes, interfaces in reflection 129 ReflectionCheckLinker.checkReflectionAccess(type, true); 130 } 131 } 132 return getAdapterInfo(types).getAdapterClass(classOverrides, protectionDomain); 133 } 134 135 private static ProtectionDomain getProtectionDomain(final MethodHandles.Lookup lookup) { 136 if((lookup.lookupModes() & Lookup.PRIVATE) == 0) { 137 return MINIMAL_PERMISSION_DOMAIN; 138 } 139 return getProtectionDomain(lookup.lookupClass()); 140 } 141 142 private static ProtectionDomain getProtectionDomain(final Class<?> clazz) { 143 return AccessController.doPrivileged(new PrivilegedAction<ProtectionDomain>() { 144 @Override 145 public ProtectionDomain run() { 146 return clazz.getProtectionDomain(); 147 } 148 }); 149 } 150 151 /** 152 * Returns a method handle representing a constructor that takes a single argument of the source type (which, 153 * really, should be one of {@link ScriptObject}, {@link ScriptFunction}, or {@link Object}, and returns an instance 154 * of the adapter for the target type. Used to implement the function autoconverters as well as the Nashorn's 155 * JSR-223 script engine's {@code getInterface()} method. 156 * @param sourceType the source type; should be either {@link ScriptObject}, {@link ScriptFunction}, or 157 * {@link Object}. In case of {@code Object}, it will return a method handle that dispatches to either the script 158 * object or function constructor at invocation based on the actual argument. 159 * @param targetType the target type, for which adapter instances will be created 160 * @return the constructor method handle. 161 * @throws Exception if anything goes wrong 162 */ 163 public static MethodHandle getConstructor(final Class<?> sourceType, final Class<?> targetType, final MethodHandles.Lookup lookup) throws Exception { 164 final StaticClass adapterClass = getAdapterClassFor(new Class<?>[] { targetType }, null, lookup); 165 return MH.bindTo(Bootstrap.getLinkerServices().getGuardedInvocation(new LinkRequestImpl( 166 NashornCallSiteDescriptor.get(lookup, "dyn:new", 167 MethodType.methodType(targetType, StaticClass.class, sourceType), 0), false, 168 adapterClass, null)).getInvocation(), adapterClass); 169 } 170 171 /** 172 * Returns whether an instance of the specified class/interface can be generated from a ScriptFunction. Returns true 173 * iff: the adapter for the class/interface can be created, it is abstract (this includes interfaces), it has at 174 * least one abstract method, all the abstract methods share the same name, and it has a public or protected default 175 * constructor. Note that invoking this class will most likely result in the adapter class being defined in the JVM 176 * if it hasn't been already. 177 * @param clazz the inspected class 178 * @return true iff an instance of the specified class/interface can be generated from a ScriptFunction. 179 */ 180 static boolean isAutoConvertibleFromFunction(final Class<?> clazz) { 181 return getAdapterInfo(new Class<?>[] { clazz }).autoConvertibleFromFunction; 182 } 183 184 private static AdapterInfo getAdapterInfo(final Class<?>[] types) { 185 final ClassAndLoader definingClassAndLoader = ClassAndLoader.getDefiningClassAndLoader(types); 186 187 final Map<List<Class<?>>, AdapterInfo> adapterInfoMap = ADAPTER_INFO_MAPS.get(definingClassAndLoader.getRepresentativeClass()); 188 final List<Class<?>> typeList = types.length == 1 ? getSingletonClassList(types[0]) : Arrays.asList(types.clone()); 189 AdapterInfo adapterInfo; 190 synchronized(adapterInfoMap) { 191 adapterInfo = adapterInfoMap.get(typeList); 192 if(adapterInfo == null) { 193 adapterInfo = createAdapterInfo(types, definingClassAndLoader); 194 adapterInfoMap.put(typeList, adapterInfo); 195 } 196 } 197 return adapterInfo; 198 } 199 200 @SuppressWarnings({ "unchecked", "rawtypes" }) 201 private static List<Class<?>> getSingletonClassList(final Class<?> clazz) { 202 return (List)Collections.singletonList(clazz); 203 } 204 205 /** 206 * For a given class, create its adapter class and associated info. 207 * @param type the class for which the adapter is created 208 * @return the adapter info for the class. 209 */ 210 private static AdapterInfo createAdapterInfo(final Class<?>[] types, final ClassAndLoader definingClassAndLoader) { 211 Class<?> superClass = null; 212 final List<Class<?>> interfaces = new ArrayList<>(types.length); 213 for(final Class<?> t: types) { 214 final int mod = t.getModifiers(); 215 if(!t.isInterface()) { 216 if(superClass != null) { 217 return new AdapterInfo(AdaptationResult.Outcome.ERROR_MULTIPLE_SUPERCLASSES, t.getCanonicalName() + " and " + superClass.getCanonicalName()); 218 } 219 if (Modifier.isFinal(mod)) { 220 return new AdapterInfo(AdaptationResult.Outcome.ERROR_FINAL_CLASS, t.getCanonicalName()); 221 } 222 superClass = t; 223 } else { 224 if (interfaces.size() > 65535) { 225 throw new IllegalArgumentException("interface limit exceeded"); 226 } 227 228 interfaces.add(t); 229 } 230 231 if(!Modifier.isPublic(mod)) { 232 return new AdapterInfo(AdaptationResult.Outcome.ERROR_NON_PUBLIC_CLASS, t.getCanonicalName()); 233 } 234 } 235 236 237 final Class<?> effectiveSuperClass = superClass == null ? Object.class : superClass; 238 return AccessController.doPrivileged(new PrivilegedAction<AdapterInfo>() { 239 @Override 240 public AdapterInfo run() { 241 try { 242 return new AdapterInfo(effectiveSuperClass, interfaces, definingClassAndLoader); 243 } catch (final AdaptationException e) { 244 return new AdapterInfo(e.getAdaptationResult()); 245 } 246 } 247 }, CREATE_ADAPTER_INFO_ACC_CTXT); 248 } 249 250 private static class AdapterInfo { 251 private static final ClassAndLoader SCRIPT_OBJECT_LOADER = new ClassAndLoader(ScriptObject.class, true); 252 253 private final ClassLoader commonLoader; 254 // TODO: soft reference the JavaAdapterClassLoader objects. They can be recreated when needed. 255 private final JavaAdapterClassLoader classAdapterGenerator; 256 private final JavaAdapterClassLoader instanceAdapterGenerator; 257 private final Map<CodeSource, StaticClass> instanceAdapters = new ConcurrentHashMap<>(); 258 final boolean autoConvertibleFromFunction; 259 final AdaptationResult adaptationResult; 260 261 AdapterInfo(Class<?> superClass, List<Class<?>> interfaces, ClassAndLoader definingLoader) throws AdaptationException { 262 this.commonLoader = findCommonLoader(definingLoader); 263 final JavaAdapterBytecodeGenerator gen = new JavaAdapterBytecodeGenerator(superClass, interfaces, commonLoader, false); 264 this.autoConvertibleFromFunction = gen.isAutoConvertibleFromFunction(); 265 instanceAdapterGenerator = gen.createAdapterClassLoader(); 266 this.classAdapterGenerator = new JavaAdapterBytecodeGenerator(superClass, interfaces, commonLoader, true).createAdapterClassLoader(); 267 this.adaptationResult = AdaptationResult.SUCCESSFUL_RESULT; 268 } 269 270 AdapterInfo(final AdaptationResult.Outcome outcome, final String classList) { 271 this(new AdaptationResult(outcome, classList)); 272 } 273 274 AdapterInfo(final AdaptationResult adaptationResult) { 275 this.commonLoader = null; 276 this.classAdapterGenerator = null; 277 this.instanceAdapterGenerator = null; 278 this.autoConvertibleFromFunction = false; 279 this.adaptationResult = adaptationResult; 280 } 281 282 StaticClass getAdapterClass(final ScriptObject classOverrides, final ProtectionDomain protectionDomain) { 283 if(adaptationResult.getOutcome() != AdaptationResult.Outcome.SUCCESS) { 284 throw adaptationResult.typeError(); 285 } 286 return classOverrides == null ? getInstanceAdapterClass(protectionDomain) : 287 getClassAdapterClass(classOverrides, protectionDomain); 288 } 289 290 private StaticClass getInstanceAdapterClass(final ProtectionDomain protectionDomain) { 291 CodeSource codeSource = protectionDomain.getCodeSource(); 292 if(codeSource == null) { 293 codeSource = MINIMAL_PERMISSION_DOMAIN.getCodeSource(); 294 } 295 StaticClass instanceAdapterClass = instanceAdapters.get(codeSource); 296 if(instanceAdapterClass != null) { 297 return instanceAdapterClass; 298 } 299 // Any "unknown source" code source will default to no permission domain. 300 final ProtectionDomain effectiveDomain = codeSource.equals(MINIMAL_PERMISSION_DOMAIN.getCodeSource()) ? 301 MINIMAL_PERMISSION_DOMAIN : protectionDomain; 302 303 instanceAdapterClass = instanceAdapterGenerator.generateClass(commonLoader, effectiveDomain); 304 final StaticClass existing = instanceAdapters.putIfAbsent(codeSource, instanceAdapterClass); 305 return existing == null ? instanceAdapterClass : existing; 306 } 307 308 private StaticClass getClassAdapterClass(final ScriptObject classOverrides, final ProtectionDomain protectionDomain) { 309 JavaAdapterServices.setClassOverrides(classOverrides); 310 try { 311 return classAdapterGenerator.generateClass(commonLoader, protectionDomain); 312 } finally { 313 JavaAdapterServices.setClassOverrides(null); 314 } 315 } 316 317 /** 318 * Choose between the passed class loader and the class loader that defines the ScriptObject class, based on which 319 * of the two can see the classes in both. 320 * @param classAndLoader the loader and a representative class from it that will be used to add the generated 321 * adapter to its ADAPTER_INFO_MAPS. 322 * @return the class loader that sees both the specified class and Nashorn classes. 323 * @throws IllegalStateException if no such class loader is found. 324 */ 325 private static ClassLoader findCommonLoader(final ClassAndLoader classAndLoader) throws AdaptationException { 326 if(classAndLoader.canSee(SCRIPT_OBJECT_LOADER)) { 327 return classAndLoader.getLoader(); 328 } 329 if (SCRIPT_OBJECT_LOADER.canSee(classAndLoader)) { 330 return SCRIPT_OBJECT_LOADER.getLoader(); 331 } 332 333 throw new AdaptationException(AdaptationResult.Outcome.ERROR_NO_COMMON_LOADER, classAndLoader.getRepresentativeClass().getCanonicalName()); 334 } 335 } 336 337 private static ProtectionDomain createMinimalPermissionDomain() { 338 // Generated classes need to have at least the permission to access Nashorn runtime and runtime.linker packages. 339 final Permissions permissions = new Permissions(); 340 permissions.add(new RuntimePermission("accessClassInPackage.jdk.nashorn.internal.runtime")); 341 permissions.add(new RuntimePermission("accessClassInPackage.jdk.nashorn.internal.runtime.linker")); 342 return new ProtectionDomain(new CodeSource(null, (CodeSigner[])null), permissions); 343 } 344 }