java/src/main/com/google/appengine/tools/development/agent/impl/ReflectionVisitor.java

   1 // Copyright 2009 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.tools.development.agent.impl;
   4
   5 import org.objectweb.asm.ClassVisitor;
   6 import org.objectweb.asm.MethodVisitor;
   7 import org.objectweb.asm.Opcodes;
   8 import org.objectweb.asm.Type;
   9 import org.objectweb.asm.commons.GeneratorAdapter;
  10
  11 import java.util.Map;
  12 import java.util.Set;
  13 import java.util.HashMap;
  14 import java.util.HashSet;
  15 import java.util.Arrays;
  16
  17 /**
  18  * Intercepts reflective operations and adds checks against the WhiteList.
  19  *
  20  */
  21 public class ReflectionVisitor extends ClassVisitor {
  22
  23   public ReflectionVisitor(final ClassVisitor classVisitor) {
  24     super(Opcodes.ASM4, classVisitor);
  25   }
  26
  27   private static final Map<String, Set<String>> interceptedMethods =
  28       new HashMap<String,Set<String>>();
  29
  30   static {
  31     interceptedMethods.put("java/lang/reflect/Method",
  32         new HashSet<String>(Arrays.asList("invoke")));
  33
  34     interceptedMethods.put("java/lang/reflect/Field",
  35         new HashSet<String>(Arrays.asList(
  36           "get",
  37           "getBoolean",
  38           "getByte",
  39           "getChar",
  40           "getDouble",
  41           "getFloat",
  42           "getInt",
  43           "getLong",
  44           "getShort",
  45           "set",
  46           "setBoolean",
  47           "setByte",
  48           "setChar",
  49           "setDouble",
  50           "setFloat",
  51           "setInt",
  52           "setLong",
  53           "setShort"
  54         )));
  55
  56     interceptedMethods.put("java/lang/reflect/Constructor",
  57         new HashSet<String>(Arrays.asList(
  58             "newInstance"
  59         )));
  60
  61     interceptedMethods.put("java/lang/Class",
  62         new HashSet<String>(Arrays.asList(
  63             "newInstance"
  64         )));
  65   }
  66
  67   @Override
  68   public MethodVisitor visitMethod(int access, String name, String desc, String signature,
  69       String[] exceptions) {
  70     MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
  71     return (mv == null) ? null : new MethodTranslator(mv, access, name, desc);
  72   }
  73
  74   private class MethodTranslator extends GeneratorAdapter {
  75     MethodTranslator(MethodVisitor methodVisitor, int access, String name, String desc) {
  76       super(methodVisitor, access, name, desc);
  77     }
  78
  79     @Override
  80     public void visitMethodInsn(int opcode, String owner, String name, String desc) {
  81       Set<String> methods = interceptedMethods.get(owner);
  82       if (methods == null || !methods.contains(name)) {
  83         super.visitMethodInsn(opcode, owner, name, desc);
  84         return;
  85       }
  86
  87       String newDesc = desc;
  88
  89       if (opcode == Opcodes.INVOKEVIRTUAL) {
  90         final Type[] argTypes = Type.getArgumentTypes(desc);
  91         final Type[] newArgTypes = new Type[argTypes.length + 1];
  92         newArgTypes[0] = Type.getType("L" + owner + ";");
  93         System.arraycopy(argTypes, 0, newArgTypes, 1, argTypes.length);
  94         newDesc = Type.getMethodDescriptor(Type.getReturnType(desc), newArgTypes);
  95       }
  96
  97       super.visitMethodInsn(Opcodes.INVOKESTATIC, AgentImpl.AGENT_RUNTIME, name, newDesc);
  98     }
  99   }
 100 }