Wed, 07 Aug 2013 16:38:44 +0200
8022509: Various Dynalink security enhancements
Reviewed-by: jlaskey, hannesw
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
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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
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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).
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26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file, and Oracle licenses the original version of this file under the BSD
31 * license:
32 */
33 /*
34 Copyright 2009-2013 Attila Szegedi
36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
37 and the BSD License (the "BSD License"), with licensee being free to
38 choose either of the two at their discretion.
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
46 You may obtain a copy of the Apache License at
48 http://www.apache.org/licenses/LICENSE-2.0
50 Unless required by applicable law or agreed to in writing, software
51 distributed under the License is distributed on an "AS IS" BASIS,
52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
53 implied. See the License for the specific language governing
54 permissions and limitations under the License.
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
59 Redistribution and use in source and binary forms, with or without
60 modification, are permitted provided that the following conditions are
61 met:
62 * Redistributions of source code must retain the above copyright
63 notice, this list of conditions and the following disclaimer.
64 * Redistributions in binary form must reproduce the above copyright
65 notice, this list of conditions and the following disclaimer in the
66 documentation and/or other materials provided with the distribution.
67 * Neither the name of the copyright holder nor the names of
68 contributors may be used to endorse or promote products derived from
69 this software without specific prior written permission.
71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
82 */
84 package jdk.internal.dynalink.support;
86 import java.lang.invoke.MethodHandle;
87 import java.lang.invoke.MethodHandles;
88 import java.lang.invoke.MethodType;
89 import java.lang.invoke.WrongMethodTypeException;
90 import java.security.AccessController;
91 import java.security.PrivilegedAction;
92 import java.util.LinkedList;
93 import java.util.List;
94 import jdk.internal.dynalink.linker.ConversionComparator;
95 import jdk.internal.dynalink.linker.ConversionComparator.Comparison;
96 import jdk.internal.dynalink.linker.GuardedInvocation;
97 import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
98 import jdk.internal.dynalink.linker.LinkerServices;
100 /**
101 * A factory for type converters. This class is the main implementation behind the
102 * {@link LinkerServices#asType(MethodHandle, MethodType)}. It manages the known {@link GuardingTypeConverterFactory}
103 * instances and creates appropriate converters for method handles.
104 *
105 * @author Attila Szegedi
106 */
107 public class TypeConverterFactory {
109 private final GuardingTypeConverterFactory[] factories;
110 private final ConversionComparator[] comparators;
112 private final ClassValue<ClassMap<MethodHandle>> converterMap = new ClassValue<ClassMap<MethodHandle>>() {
113 @Override
114 protected ClassMap<MethodHandle> computeValue(final Class<?> sourceType) {
115 return new ClassMap<MethodHandle>(getClassLoader(sourceType)) {
116 @Override
117 protected MethodHandle computeValue(Class<?> targetType) {
118 try {
119 return createConverter(sourceType, targetType);
120 } catch (RuntimeException e) {
121 throw e;
122 } catch (Exception e) {
123 throw new RuntimeException(e);
124 }
125 }
126 };
127 }
128 };
130 private final ClassValue<ClassMap<MethodHandle>> converterIdentityMap = new ClassValue<ClassMap<MethodHandle>>() {
131 @Override
132 protected ClassMap<MethodHandle> computeValue(final Class<?> sourceType) {
133 return new ClassMap<MethodHandle>(getClassLoader(sourceType)) {
134 @Override
135 protected MethodHandle computeValue(Class<?> targetType) {
136 if(!canAutoConvert(sourceType, targetType)) {
137 final MethodHandle converter = getTypeConverterNull(sourceType, targetType);
138 if(converter != null) {
139 return converter;
140 }
141 }
142 return IDENTITY_CONVERSION.asType(MethodType.methodType(targetType, sourceType));
143 }
144 };
145 }
146 };
148 private static final ClassLoader getClassLoader(final Class<?> clazz) {
149 return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
150 @Override
151 public ClassLoader run() {
152 return clazz.getClassLoader();
153 }
154 });
155 }
157 /**
158 * Creates a new type converter factory from the available {@link GuardingTypeConverterFactory} instances.
159 *
160 * @param factories the {@link GuardingTypeConverterFactory} instances to compose.
161 */
162 public TypeConverterFactory(Iterable<? extends GuardingTypeConverterFactory> factories) {
163 final List<GuardingTypeConverterFactory> l = new LinkedList<>();
164 final List<ConversionComparator> c = new LinkedList<>();
165 for(GuardingTypeConverterFactory factory: factories) {
166 l.add(factory);
167 if(factory instanceof ConversionComparator) {
168 c.add((ConversionComparator)factory);
169 }
170 }
171 this.factories = l.toArray(new GuardingTypeConverterFactory[l.size()]);
172 this.comparators = c.toArray(new ConversionComparator[c.size()]);
174 }
176 /**
177 * Similar to {@link MethodHandle#asType(MethodType)} except it also hooks in method handles produced by
178 * {@link GuardingTypeConverterFactory} implementations, providing for language-specific type coercing of
179 * parameters. It will apply {@link MethodHandle#asType(MethodType)} for all primitive-to-primitive,
180 * wrapper-to-primitive, primitive-to-wrapper conversions as well as for all upcasts. For all other conversions,
181 * it'll insert {@link MethodHandles#filterArguments(MethodHandle, int, MethodHandle...)} with composite filters
182 * provided by {@link GuardingTypeConverterFactory} implementations.
183 *
184 * @param handle target method handle
185 * @param fromType the types of source arguments
186 * @return a method handle that is a suitable combination of {@link MethodHandle#asType(MethodType)} and
187 * {@link MethodHandles#filterArguments(MethodHandle, int, MethodHandle...)} with
188 * {@link GuardingTypeConverterFactory} produced type converters as filters.
189 */
190 public MethodHandle asType(MethodHandle handle, final MethodType fromType) {
191 MethodHandle newHandle = handle;
192 final MethodType toType = newHandle.type();
193 final int l = toType.parameterCount();
194 if(l != fromType.parameterCount()) {
195 throw new WrongMethodTypeException("Parameter counts differ: " + handle.type() + " vs. " + fromType);
196 }
197 int pos = 0;
198 final List<MethodHandle> converters = new LinkedList<>();
199 for(int i = 0; i < l; ++i) {
200 final Class<?> fromParamType = fromType.parameterType(i);
201 final Class<?> toParamType = toType.parameterType(i);
202 if(canAutoConvert(fromParamType, toParamType)) {
203 newHandle = applyConverters(newHandle, pos, converters);
204 } else {
205 final MethodHandle converter = getTypeConverterNull(fromParamType, toParamType);
206 if(converter != null) {
207 if(converters.isEmpty()) {
208 pos = i;
209 }
210 converters.add(converter);
211 } else {
212 newHandle = applyConverters(newHandle, pos, converters);
213 }
214 }
215 }
216 newHandle = applyConverters(newHandle, pos, converters);
218 // Convert return type
219 final Class<?> fromRetType = fromType.returnType();
220 final Class<?> toRetType = toType.returnType();
221 if(fromRetType != Void.TYPE && toRetType != Void.TYPE) {
222 if(!canAutoConvert(toRetType, fromRetType)) {
223 final MethodHandle converter = getTypeConverterNull(toRetType, fromRetType);
224 if(converter != null) {
225 newHandle = MethodHandles.filterReturnValue(newHandle, converter);
226 }
227 }
228 }
230 // Take care of automatic conversions
231 return newHandle.asType(fromType);
232 }
234 private static MethodHandle applyConverters(MethodHandle handle, int pos, List<MethodHandle> converters) {
235 if(converters.isEmpty()) {
236 return handle;
237 }
238 final MethodHandle newHandle =
239 MethodHandles.filterArguments(handle, pos, converters.toArray(new MethodHandle[converters.size()]));
240 converters.clear();
241 return newHandle;
242 }
244 /**
245 * Returns true if there might exist a conversion between the requested types (either an automatic JVM conversion,
246 * or one provided by any available {@link GuardingTypeConverterFactory}), or false if there definitely does not
247 * exist a conversion between the requested types. Note that returning true does not guarantee that the conversion
248 * will succeed at runtime (notably, if the "from" or "to" types are sufficiently generic), but returning false
249 * guarantees that it would fail.
250 *
251 * @param from the source type for the conversion
252 * @param to the target type for the conversion
253 * @return true if there can be a conversion, false if there can not.
254 */
255 public boolean canConvert(final Class<?> from, final Class<?> to) {
256 return canAutoConvert(from, to) || getTypeConverterNull(from, to) != null;
257 }
259 /**
260 * Determines which of the two type conversions from a source type to the two target types is preferred. This is
261 * used for dynamic overloaded method resolution. If the source type is convertible to exactly one target type with
262 * a method invocation conversion, it is chosen, otherwise available {@link ConversionComparator}s are consulted.
263 * @param sourceType the source type.
264 * @param targetType1 one potential target type
265 * @param targetType2 another potential target type.
266 * @return one of Comparison constants that establish which - if any - of the target types is preferable for the
267 * conversion.
268 */
269 public Comparison compareConversion(Class<?> sourceType, Class<?> targetType1, Class<?> targetType2) {
270 for(ConversionComparator comparator: comparators) {
271 final Comparison result = comparator.compareConversion(sourceType, targetType1, targetType2);
272 if(result != Comparison.INDETERMINATE) {
273 return result;
274 }
275 }
276 if(TypeUtilities.isMethodInvocationConvertible(sourceType, targetType1)) {
277 if(!TypeUtilities.isMethodInvocationConvertible(sourceType, targetType2)) {
278 return Comparison.TYPE_1_BETTER;
279 }
280 } else if(TypeUtilities.isMethodInvocationConvertible(sourceType, targetType2)) {
281 return Comparison.TYPE_2_BETTER;
282 }
283 return Comparison.INDETERMINATE;
284 }
286 /**
287 * Determines whether it's safe to perform an automatic conversion between the source and target class.
288 *
289 * @param fromType convert from this class
290 * @param toType convert to this class
291 * @return true if it's safe to let MethodHandles.convertArguments() to handle this conversion.
292 */
293 /*private*/ static boolean canAutoConvert(final Class<?> fromType, final Class<?> toType) {
294 return TypeUtilities.isMethodInvocationConvertible(fromType, toType);
295 }
297 /*private*/ MethodHandle getTypeConverterNull(Class<?> sourceType, Class<?> targetType) {
298 final MethodHandle converter = converterMap.get(sourceType).get(targetType);
299 return converter == IDENTITY_CONVERSION ? null : converter;
300 }
302 /**
303 * Given a source and target type, returns a method handle that converts between them. Never returns null; in worst
304 * case it will return an identity conversion (that might fail for some values at runtime). You can use this method
305 * if you have a piece of your program that is written in Java, and you need to reuse existing type conversion
306 * machinery in a non-invokedynamic context.
307 * @param sourceType the type to convert from
308 * @param targetType the type to convert to
309 * @return a method handle performing the conversion.
310 */
311 public MethodHandle getTypeConverter(Class<?> sourceType, Class<?> targetType) {
312 return converterIdentityMap.get(sourceType).get(targetType);
313 }
315 /*private*/ MethodHandle createConverter(Class<?> sourceType, Class<?> targetType) throws Exception {
316 final MethodType type = MethodType.methodType(targetType, sourceType);
317 final MethodHandle identity = IDENTITY_CONVERSION.asType(type);
318 MethodHandle last = identity;
319 for(int i = factories.length; i-- > 0;) {
320 final GuardedInvocation next = factories[i].convertToType(sourceType, targetType);
321 if(next != null) {
322 next.assertType(type);
323 last = next.compose(last);
324 }
325 }
326 return last == identity ? IDENTITY_CONVERSION : last;
327 }
329 /*private*/ static final MethodHandle IDENTITY_CONVERSION = MethodHandles.identity(Object.class);
330 }