nashorn/src/jdk/nashorn/internal/runtime/linker/JavaAdapterClassLoader.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package jdk.nashorn.internal.runtime.linker;

 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_FINAL;
 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PRIVATE;
 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC;
 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_STATIC;
 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_SUPER;
 import static jdk.internal.org.objectweb.asm.Opcodes.ACONST_NULL;
 import static jdk.internal.org.objectweb.asm.Opcodes.ALOAD;
 import static jdk.internal.org.objectweb.asm.Opcodes.ARETURN;
 import static jdk.internal.org.objectweb.asm.Opcodes.RETURN;

 import java.security.AccessController;
 import java.security.AllPermission;
 import java.security.CodeSigner;
 import java.security.CodeSource;
 import java.security.Permissions;
 import java.security.PrivilegedAction;
 import java.security.ProtectionDomain;
 import java.security.SecureClassLoader;

 import jdk.internal.dynalink.beans.StaticClass;
 import jdk.internal.org.objectweb.asm.ClassWriter;
 import jdk.internal.org.objectweb.asm.Opcodes;
 import jdk.internal.org.objectweb.asm.Type;
 import jdk.internal.org.objectweb.asm.commons.InstructionAdapter;
 import jdk.nashorn.internal.runtime.Context;
 import jdk.nashorn.internal.runtime.ScriptObject;

 /**
  * This class encapsulates the bytecode of the adapter class and can be used to load it into the JVM as an actual Class.
  * It can be invoked repeatedly to create multiple adapter classes from the same bytecode; adapter classes that have
  * class-level overrides must be re-created for every set of such overrides. Note that while this class is named
  * "class loader", it does not, in fact, extend {@code ClassLoader}, but rather uses them internally. Instances of this
  * class are normally created by {@link JavaAdapterBytecodeGenerator}.
  */
 @SuppressWarnings("javadoc")
 class JavaAdapterClassLoader extends JavaAdapterGeneratorBase {
     private static final Type PRIVILEGED_ACTION_TYPE = Type.getType(PrivilegedAction.class);

     private static final String PRIVILEGED_ACTION_TYPE_NAME = PRIVILEGED_ACTION_TYPE.getInternalName();
     private static final String PRIVILEGED_RUN_METHOD_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE);

     private static final ProtectionDomain GENERATED_PROTECTION_DOMAIN = createGeneratedProtectionDomain();

     private final String className;
     private final byte[] classBytes;
     private final String globalSetterClassName;

     JavaAdapterClassLoader(String className, byte[] classBytes, String globalSetterClassName) {
         this.className = className.replace('/', '.');
         this.classBytes = classBytes;
         this.globalSetterClassName = globalSetterClassName.replace('/', '.');
     }

     /**
      * Loads the generated adapter class into the JVM.
      * @param parentLoader the parent class loader for the generated class loader
      * @return the generated adapter class
      */
     StaticClass generateClass(final ClassLoader parentLoader) {
         return AccessController.doPrivileged(new PrivilegedAction<StaticClass>() {
             @Override
             public StaticClass run() {
                 try {
                     return StaticClass.forClass(Class.forName(className, true, createClassLoader(parentLoader)));
                 } catch (final ClassNotFoundException e) {
                     throw new AssertionError(e); // cannot happen
                 }
             }
         });
     }

     private static class AdapterLoader extends SecureClassLoader {
         AdapterLoader(ClassLoader parent) {
             super(parent);
         }
     }

     static boolean isAdapterClass(Class<?> clazz) {
         return clazz.getClassLoader() instanceof AdapterLoader;
     }

     // Note that the adapter class is created in the protection domain of the class/interface being
     // extended/implemented, and only the privileged global setter action class is generated in the protection domain
     // of Nashorn itself. Also note that the creation and loading of the global setter is deferred until it is
     // required by JVM linker, which will only happen on first invocation of any of the adapted method. We could defer
     // it even more by separating its invocation into a separate static method on the adapter class, but then someone
     // with ability to introspect on the class and use setAccessible(true) on it could invoke the method. It's a
     // security tradeoff...
     private ClassLoader createClassLoader(final ClassLoader parentLoader) {
         return new AdapterLoader(parentLoader) {
             private final ClassLoader myLoader = getClass().getClassLoader();
             private final ProtectionDomain myProtectionDomain = getClass().getProtectionDomain();

             @Override
             public Class<?> loadClass(final String name, final boolean resolve) throws ClassNotFoundException {
                 try {
                     return super.loadClass(name, resolve);
                 } catch (final SecurityException se) {
                     // we may be implementing an interface or extending a class that was
                     // loaded by a loader that prevents package.access. If so, it'd throw
                     // SecurityException for nashorn's classes!. For adapter's to work, we
                     // should be able to refer to nashorn classes.
                     if (name.startsWith("jdk.nashorn.internal.")) {
                         return myLoader.loadClass(name);
                     }
                     throw se;
                 }
             }

             @Override
             protected Class<?> findClass(final String name) throws ClassNotFoundException {
                 if(name.equals(className)) {
                     return defineClass(name, classBytes, 0, classBytes.length, GENERATED_PROTECTION_DOMAIN);
                 } else if(name.equals(globalSetterClassName)) {
                     final byte[] bytes = generatePrivilegedActionClassBytes(globalSetterClassName.replace('.', '/'));
                     return defineClass(name, bytes, 0, bytes.length, myProtectionDomain);
                 } else {
                     throw new ClassNotFoundException(name);
                 }
             }
         };
     }

     private static ProtectionDomain createGeneratedProtectionDomain() {
         // Generated classes need to have AllPermission. Since we require the "createClassLoader" RuntimePermission, we
         // can create a class loader that'll load new classes with any permissions. Our generated classes are just
         // delegating adapters, so having AllPermission can't cause anything wrong; the effective set of permissions for
         // the executing script functions will still be limited by the permissions of the caller and the permissions of
         // the script.
         final Permissions permissions = new Permissions();
         permissions.add(new AllPermission());
         return new ProtectionDomain(new CodeSource(null, (CodeSigner[])null), permissions);
     }

     /**
      * Generates a PrivilegedAction implementation class for invoking {@link Context#setGlobal(ScriptObject)} from the
      * adapter class.
      */
     private static byte[] generatePrivilegedActionClassBytes(final String className) {
         final ClassWriter w = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
         // class GlobalSetter implements PrivilegedAction {
         w.visit(Opcodes.V1_7, ACC_SUPER | ACC_FINAL, className, null, OBJECT_TYPE_NAME, new String[] {
                 PRIVILEGED_ACTION_TYPE_NAME
         });

         // private final ScriptObject global;
         w.visitField(ACC_PRIVATE | ACC_FINAL, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR, null, null).visitEnd();

         // private GlobalSetter(ScriptObject global) {
         InstructionAdapter mv = new InstructionAdapter(w.visitMethod(ACC_PRIVATE, INIT,
                 SET_GLOBAL_METHOD_DESCRIPTOR, null, new String[0]));
         mv.visitCode();
         // super();
         mv.visitVarInsn(ALOAD, 0);
         mv.invokespecial(OBJECT_TYPE_NAME, INIT, VOID_NOARG_METHOD_DESCRIPTOR);
         // this.global = global;
         mv.visitVarInsn(ALOAD, 0);
         mv.visitVarInsn(ALOAD, 1);
         mv.putfield(className, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

         mv.visitInsn(RETURN);
         mv.visitEnd();
         mv.visitMaxs(0, 0);

         // public Object run() {
         mv = new InstructionAdapter(w.visitMethod(ACC_PUBLIC, "run", PRIVILEGED_RUN_METHOD_DESCRIPTOR, null,
                 new String[0]));
         mv.visitCode();
         // Context.setGlobal(this.global);
         mv.visitVarInsn(ALOAD, 0);
         mv.getfield(className, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);
         mv.invokestatic(CONTEXT_TYPE_NAME, "setGlobal", SET_GLOBAL_METHOD_DESCRIPTOR);
         // return null;
         mv.visitInsn(ACONST_NULL);
         mv.visitInsn(ARETURN);

         mv.visitEnd();
         mv.visitMaxs(0, 0);

         // static void setGlobal(ScriptObject global) {
         mv = new InstructionAdapter(w.visitMethod(ACC_STATIC, "setGlobal", SET_GLOBAL_METHOD_DESCRIPTOR, null,
                 new String[0]));
         mv.visitCode();
         // new GlobalSetter(ScriptObject global)
         mv.anew(Type.getType("L" + className + ";"));
         mv.dup();
         mv.visitVarInsn(ALOAD, 0);
         mv.invokespecial(className, INIT, SET_GLOBAL_METHOD_DESCRIPTOR);
         // AccessController.doPrivileged(...)
         mv.invokestatic(Type.getInternalName(AccessController.class), "doPrivileged", Type.getMethodDescriptor(
                 OBJECT_TYPE, PRIVILEGED_ACTION_TYPE));
         mv.pop();
         mv.visitInsn(RETURN);

         mv.visitEnd();
         mv.visitMaxs(0, 0);

         return w.toByteArray();
     }
 }
	/*
	* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package jdk.nashorn.internal.runtime.linker;

	import static jdk.internal.org.objectweb.asm.Opcodes.ACC_FINAL;
	import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PRIVATE;
	import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC;
	import static jdk.internal.org.objectweb.asm.Opcodes.ACC_STATIC;
	import static jdk.internal.org.objectweb.asm.Opcodes.ACC_SUPER;
	import static jdk.internal.org.objectweb.asm.Opcodes.ACONST_NULL;
	import static jdk.internal.org.objectweb.asm.Opcodes.ALOAD;
	import static jdk.internal.org.objectweb.asm.Opcodes.ARETURN;
	import static jdk.internal.org.objectweb.asm.Opcodes.RETURN;

	import java.security.AccessController;
	import java.security.AllPermission;
	import java.security.CodeSigner;
	import java.security.CodeSource;
	import java.security.Permissions;
	import java.security.PrivilegedAction;
	import java.security.ProtectionDomain;
	import java.security.SecureClassLoader;

	import jdk.internal.dynalink.beans.StaticClass;
	import jdk.internal.org.objectweb.asm.ClassWriter;
	import jdk.internal.org.objectweb.asm.Opcodes;
	import jdk.internal.org.objectweb.asm.Type;
	import jdk.internal.org.objectweb.asm.commons.InstructionAdapter;
	import jdk.nashorn.internal.runtime.Context;
	import jdk.nashorn.internal.runtime.ScriptObject;

	/**
	* This class encapsulates the bytecode of the adapter class and can be used to load it into the JVM as an actual Class.
	* It can be invoked repeatedly to create multiple adapter classes from the same bytecode; adapter classes that have
	* class-level overrides must be re-created for every set of such overrides. Note that while this class is named
	* "class loader", it does not, in fact, extend {@code ClassLoader}, but rather uses them internally. Instances of this
	* class are normally created by {@link JavaAdapterBytecodeGenerator}.
	*/
	@SuppressWarnings("javadoc")
	class JavaAdapterClassLoader extends JavaAdapterGeneratorBase {
	private static final Type PRIVILEGED_ACTION_TYPE = Type.getType(PrivilegedAction.class);

	private static final String PRIVILEGED_ACTION_TYPE_NAME = PRIVILEGED_ACTION_TYPE.getInternalName();
	private static final String PRIVILEGED_RUN_METHOD_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE);

	private static final ProtectionDomain GENERATED_PROTECTION_DOMAIN = createGeneratedProtectionDomain();

	private final String className;
	private final byte[] classBytes;
	private final String globalSetterClassName;

	JavaAdapterClassLoader(String className, byte[] classBytes, String globalSetterClassName) {
	this.className = className.replace('/', '.');
	this.classBytes = classBytes;
	this.globalSetterClassName = globalSetterClassName.replace('/', '.');
	}

	/**
	* Loads the generated adapter class into the JVM.
	* @param parentLoader the parent class loader for the generated class loader
	* @return the generated adapter class
	*/
	StaticClass generateClass(final ClassLoader parentLoader) {
	return AccessController.doPrivileged(new PrivilegedAction<StaticClass>() {
	@Override
	public StaticClass run() {
	try {
	return StaticClass.forClass(Class.forName(className, true, createClassLoader(parentLoader)));
	} catch (final ClassNotFoundException e) {
	throw new AssertionError(e); // cannot happen
	}
	}
	});
	}

	private static class AdapterLoader extends SecureClassLoader {
	AdapterLoader(ClassLoader parent) {
	super(parent);
	}
	}

	static boolean isAdapterClass(Class<?> clazz) {
	return clazz.getClassLoader() instanceof AdapterLoader;
	}

	// Note that the adapter class is created in the protection domain of the class/interface being
	// extended/implemented, and only the privileged global setter action class is generated in the protection domain
	// of Nashorn itself. Also note that the creation and loading of the global setter is deferred until it is
	// required by JVM linker, which will only happen on first invocation of any of the adapted method. We could defer
	// it even more by separating its invocation into a separate static method on the adapter class, but then someone
	// with ability to introspect on the class and use setAccessible(true) on it could invoke the method. It's a
	// security tradeoff...
	private ClassLoader createClassLoader(final ClassLoader parentLoader) {
	return new AdapterLoader(parentLoader) {
	private final ClassLoader myLoader = getClass().getClassLoader();
	private final ProtectionDomain myProtectionDomain = getClass().getProtectionDomain();

	@Override
	public Class<?> loadClass(final String name, final boolean resolve) throws ClassNotFoundException {
	try {
	return super.loadClass(name, resolve);
	} catch (final SecurityException se) {
	// we may be implementing an interface or extending a class that was
	// loaded by a loader that prevents package.access. If so, it'd throw
	// SecurityException for nashorn's classes!. For adapter's to work, we
	// should be able to refer to nashorn classes.
	if (name.startsWith("jdk.nashorn.internal.")) {
	return myLoader.loadClass(name);
	}
	throw se;
	}
	}

	@Override
	protected Class<?> findClass(final String name) throws ClassNotFoundException {
	if(name.equals(className)) {
	return defineClass(name, classBytes, 0, classBytes.length, GENERATED_PROTECTION_DOMAIN);
	} else if(name.equals(globalSetterClassName)) {
	final byte[] bytes = generatePrivilegedActionClassBytes(globalSetterClassName.replace('.', '/'));
	return defineClass(name, bytes, 0, bytes.length, myProtectionDomain);
	} else {
	throw new ClassNotFoundException(name);
	}
	}
	};
	}

	private static ProtectionDomain createGeneratedProtectionDomain() {
	// Generated classes need to have AllPermission. Since we require the "createClassLoader" RuntimePermission, we
	// can create a class loader that'll load new classes with any permissions. Our generated classes are just
	// delegating adapters, so having AllPermission can't cause anything wrong; the effective set of permissions for
	// the executing script functions will still be limited by the permissions of the caller and the permissions of
	// the script.
	final Permissions permissions = new Permissions();
	permissions.add(new AllPermission());
	return new ProtectionDomain(new CodeSource(null, (CodeSigner[])null), permissions);
	}

	/**
	* Generates a PrivilegedAction implementation class for invoking {@link Context#setGlobal(ScriptObject)} from the
	* adapter class.
	*/
	private static byte[] generatePrivilegedActionClassBytes(final String className) {
	final ClassWriter w = new ClassWriter(ClassWriter.COMPUTE_FRAMES \| ClassWriter.COMPUTE_MAXS);
	// class GlobalSetter implements PrivilegedAction {
	w.visit(Opcodes.V1_7, ACC_SUPER \| ACC_FINAL, className, null, OBJECT_TYPE_NAME, new String[] {
	PRIVILEGED_ACTION_TYPE_NAME
	});

	// private final ScriptObject global;
	w.visitField(ACC_PRIVATE \| ACC_FINAL, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR, null, null).visitEnd();

	// private GlobalSetter(ScriptObject global) {
	InstructionAdapter mv = new InstructionAdapter(w.visitMethod(ACC_PRIVATE, INIT,
	SET_GLOBAL_METHOD_DESCRIPTOR, null, new String[0]));
	mv.visitCode();
	// super();
	mv.visitVarInsn(ALOAD, 0);
	mv.invokespecial(OBJECT_TYPE_NAME, INIT, VOID_NOARG_METHOD_DESCRIPTOR);
	// this.global = global;
	mv.visitVarInsn(ALOAD, 0);
	mv.visitVarInsn(ALOAD, 1);
	mv.putfield(className, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

	mv.visitInsn(RETURN);
	mv.visitEnd();
	mv.visitMaxs(0, 0);

	// public Object run() {
	mv = new InstructionAdapter(w.visitMethod(ACC_PUBLIC, "run", PRIVILEGED_RUN_METHOD_DESCRIPTOR, null,
	new String[0]));
	mv.visitCode();
	// Context.setGlobal(this.global);
	mv.visitVarInsn(ALOAD, 0);
	mv.getfield(className, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);
	mv.invokestatic(CONTEXT_TYPE_NAME, "setGlobal", SET_GLOBAL_METHOD_DESCRIPTOR);
	// return null;
	mv.visitInsn(ACONST_NULL);
	mv.visitInsn(ARETURN);

	mv.visitEnd();
	mv.visitMaxs(0, 0);

	// static void setGlobal(ScriptObject global) {
	mv = new InstructionAdapter(w.visitMethod(ACC_STATIC, "setGlobal", SET_GLOBAL_METHOD_DESCRIPTOR, null,
	new String[0]));
	mv.visitCode();
	// new GlobalSetter(ScriptObject global)
	mv.anew(Type.getType("L" + className + ";"));
	mv.dup();
	mv.visitVarInsn(ALOAD, 0);
	mv.invokespecial(className, INIT, SET_GLOBAL_METHOD_DESCRIPTOR);
	// AccessController.doPrivileged(...)
	mv.invokestatic(Type.getInternalName(AccessController.class), "doPrivileged", Type.getMethodDescriptor(
	OBJECT_TYPE, PRIVILEGED_ACTION_TYPE));
	mv.pop();
	mv.visitInsn(RETURN);

	mv.visitEnd();
	mv.visitMaxs(0, 0);

	return w.toByteArray();
	}
	}