|
| 1 | +/* |
| 2 | + * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one |
| 3 | + * or more contributor license agreements. Licensed under the "Elastic License |
| 4 | + * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side |
| 5 | + * Public License v 1"; you may not use this file except in compliance with, at |
| 6 | + * your election, the "Elastic License 2.0", the "GNU Affero General Public |
| 7 | + * License v3.0 only", or the "Server Side Public License, v 1". |
| 8 | + */ |
| 9 | + |
| 10 | +package org.elasticsearch.entitlement.instrumentation.impl; |
| 11 | + |
| 12 | +import org.elasticsearch.entitlement.instrumentation.Instrumenter; |
| 13 | +import org.elasticsearch.entitlement.instrumentation.MethodKey; |
| 14 | +import org.objectweb.asm.AnnotationVisitor; |
| 15 | +import org.objectweb.asm.ClassReader; |
| 16 | +import org.objectweb.asm.ClassVisitor; |
| 17 | +import org.objectweb.asm.ClassWriter; |
| 18 | +import org.objectweb.asm.MethodVisitor; |
| 19 | +import org.objectweb.asm.Opcodes; |
| 20 | +import org.objectweb.asm.Type; |
| 21 | + |
| 22 | +import java.io.IOException; |
| 23 | +import java.io.InputStream; |
| 24 | +import java.lang.reflect.Method; |
| 25 | +import java.util.Map; |
| 26 | +import java.util.stream.Stream; |
| 27 | + |
| 28 | +import static org.objectweb.asm.ClassWriter.COMPUTE_FRAMES; |
| 29 | +import static org.objectweb.asm.ClassWriter.COMPUTE_MAXS; |
| 30 | +import static org.objectweb.asm.Opcodes.ACC_STATIC; |
| 31 | +import static org.objectweb.asm.Opcodes.GETSTATIC; |
| 32 | +import static org.objectweb.asm.Opcodes.INVOKEINTERFACE; |
| 33 | +import static org.objectweb.asm.Opcodes.INVOKESTATIC; |
| 34 | +import static org.objectweb.asm.Opcodes.INVOKEVIRTUAL; |
| 35 | + |
| 36 | +public class InstrumenterImpl implements Instrumenter { |
| 37 | + /** |
| 38 | + * To avoid class name collisions during testing without an agent to replace classes in-place. |
| 39 | + */ |
| 40 | + private final String classNameSuffix; |
| 41 | + private final Map<MethodKey, Method> instrumentationMethods; |
| 42 | + |
| 43 | + public InstrumenterImpl(String classNameSuffix, Map<MethodKey, Method> instrumentationMethods) { |
| 44 | + this.classNameSuffix = classNameSuffix; |
| 45 | + this.instrumentationMethods = instrumentationMethods; |
| 46 | + } |
| 47 | + |
| 48 | + public ClassFileInfo instrumentClassFile(Class<?> clazz) throws IOException { |
| 49 | + ClassFileInfo initial = getClassFileInfo(clazz); |
| 50 | + return new ClassFileInfo(initial.fileName(), instrumentClass(Type.getInternalName(clazz), initial.bytecodes())); |
| 51 | + } |
| 52 | + |
| 53 | + public static ClassFileInfo getClassFileInfo(Class<?> clazz) throws IOException { |
| 54 | + String internalName = Type.getInternalName(clazz); |
| 55 | + String fileName = "/" + internalName + ".class"; |
| 56 | + byte[] originalBytecodes; |
| 57 | + try (InputStream classStream = clazz.getResourceAsStream(fileName)) { |
| 58 | + if (classStream == null) { |
| 59 | + throw new IllegalStateException("Classfile not found in jar: " + fileName); |
| 60 | + } |
| 61 | + originalBytecodes = classStream.readAllBytes(); |
| 62 | + } |
| 63 | + return new ClassFileInfo(fileName, originalBytecodes); |
| 64 | + } |
| 65 | + |
| 66 | + @Override |
| 67 | + public byte[] instrumentClass(String className, byte[] classfileBuffer) { |
| 68 | + ClassReader reader = new ClassReader(classfileBuffer); |
| 69 | + ClassWriter writer = new ClassWriter(reader, COMPUTE_FRAMES | COMPUTE_MAXS); |
| 70 | + ClassVisitor visitor = new EntitlementClassVisitor(Opcodes.ASM9, writer, className); |
| 71 | + reader.accept(visitor, 0); |
| 72 | + return writer.toByteArray(); |
| 73 | + } |
| 74 | + |
| 75 | + class EntitlementClassVisitor extends ClassVisitor { |
| 76 | + final String className; |
| 77 | + |
| 78 | + EntitlementClassVisitor(int api, ClassVisitor classVisitor, String className) { |
| 79 | + super(api, classVisitor); |
| 80 | + this.className = className; |
| 81 | + } |
| 82 | + |
| 83 | + @Override |
| 84 | + public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) { |
| 85 | + super.visit(version, access, name + classNameSuffix, signature, superName, interfaces); |
| 86 | + } |
| 87 | + |
| 88 | + @Override |
| 89 | + public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) { |
| 90 | + var mv = super.visitMethod(access, name, descriptor, signature, exceptions); |
| 91 | + boolean isStatic = (access & ACC_STATIC) != 0; |
| 92 | + var key = new MethodKey( |
| 93 | + className, |
| 94 | + name, |
| 95 | + Stream.of(Type.getArgumentTypes(descriptor)).map(Type::getInternalName).toList(), |
| 96 | + isStatic |
| 97 | + ); |
| 98 | + var instrumentationMethod = instrumentationMethods.get(key); |
| 99 | + if (instrumentationMethod != null) { |
| 100 | + // LOGGER.debug("Will instrument method {}", key); |
| 101 | + return new EntitlementMethodVisitor(Opcodes.ASM9, mv, isStatic, descriptor, instrumentationMethod); |
| 102 | + } else { |
| 103 | + // LOGGER.trace("Will not instrument method {}", key); |
| 104 | + } |
| 105 | + return mv; |
| 106 | + } |
| 107 | + } |
| 108 | + |
| 109 | + static class EntitlementMethodVisitor extends MethodVisitor { |
| 110 | + private final boolean instrumentedMethodIsStatic; |
| 111 | + private final String instrumentedMethodDescriptor; |
| 112 | + private final Method instrumentationMethod; |
| 113 | + private boolean hasCallerSensitiveAnnotation = false; |
| 114 | + |
| 115 | + EntitlementMethodVisitor( |
| 116 | + int api, |
| 117 | + MethodVisitor methodVisitor, |
| 118 | + boolean instrumentedMethodIsStatic, |
| 119 | + String instrumentedMethodDescriptor, |
| 120 | + Method instrumentationMethod |
| 121 | + ) { |
| 122 | + super(api, methodVisitor); |
| 123 | + this.instrumentedMethodIsStatic = instrumentedMethodIsStatic; |
| 124 | + this.instrumentedMethodDescriptor = instrumentedMethodDescriptor; |
| 125 | + this.instrumentationMethod = instrumentationMethod; |
| 126 | + } |
| 127 | + |
| 128 | + @Override |
| 129 | + public AnnotationVisitor visitAnnotation(String descriptor, boolean visible) { |
| 130 | + if (visible && descriptor.endsWith("CallerSensitive;")) { |
| 131 | + hasCallerSensitiveAnnotation = true; |
| 132 | + } |
| 133 | + return super.visitAnnotation(descriptor, visible); |
| 134 | + } |
| 135 | + |
| 136 | + @Override |
| 137 | + public void visitCode() { |
| 138 | + pushEntitlementChecksObject(); |
| 139 | + pushCallerClass(); |
| 140 | + forwardIncomingArguments(); |
| 141 | + invokeInstrumentationMethod(); |
| 142 | + super.visitCode(); |
| 143 | + } |
| 144 | + |
| 145 | + private void pushEntitlementChecksObject() { |
| 146 | + mv.visitMethodInsn( |
| 147 | + INVOKESTATIC, |
| 148 | + "org/elasticsearch/entitlement/api/EntitlementProvider", |
| 149 | + "checks", |
| 150 | + "()Lorg/elasticsearch/entitlement/api/EntitlementChecks;", |
| 151 | + false |
| 152 | + ); |
| 153 | + } |
| 154 | + |
| 155 | + private void pushCallerClass() { |
| 156 | + if (hasCallerSensitiveAnnotation) { |
| 157 | + mv.visitMethodInsn( |
| 158 | + INVOKESTATIC, |
| 159 | + "jdk/internal/reflect/Reflection", |
| 160 | + "getCallerClass", |
| 161 | + Type.getMethodDescriptor(Type.getType(Class.class)), |
| 162 | + false |
| 163 | + ); |
| 164 | + } else { |
| 165 | + mv.visitFieldInsn( |
| 166 | + GETSTATIC, |
| 167 | + Type.getInternalName(StackWalker.Option.class), |
| 168 | + "RETAIN_CLASS_REFERENCE", |
| 169 | + Type.getDescriptor(StackWalker.Option.class) |
| 170 | + ); |
| 171 | + mv.visitMethodInsn( |
| 172 | + INVOKESTATIC, |
| 173 | + Type.getInternalName(StackWalker.class), |
| 174 | + "getInstance", |
| 175 | + Type.getMethodDescriptor(Type.getType(StackWalker.class), Type.getType(StackWalker.Option.class)), |
| 176 | + false |
| 177 | + ); |
| 178 | + mv.visitMethodInsn( |
| 179 | + INVOKEVIRTUAL, |
| 180 | + Type.getInternalName(StackWalker.class), |
| 181 | + "getCallerClass", |
| 182 | + Type.getMethodDescriptor(Type.getType(Class.class)), |
| 183 | + false |
| 184 | + ); |
| 185 | + } |
| 186 | + } |
| 187 | + |
| 188 | + private void forwardIncomingArguments() { |
| 189 | + int localVarIndex = 0; |
| 190 | + if (instrumentedMethodIsStatic == false) { |
| 191 | + mv.visitVarInsn(Opcodes.ALOAD, localVarIndex++); |
| 192 | + } |
| 193 | + for (Type type : Type.getArgumentTypes(instrumentedMethodDescriptor)) { |
| 194 | + mv.visitVarInsn(type.getOpcode(Opcodes.ILOAD), localVarIndex); |
| 195 | + localVarIndex += type.getSize(); |
| 196 | + } |
| 197 | + |
| 198 | + } |
| 199 | + |
| 200 | + private void invokeInstrumentationMethod() { |
| 201 | + mv.visitMethodInsn( |
| 202 | + INVOKEINTERFACE, |
| 203 | + Type.getInternalName(instrumentationMethod.getDeclaringClass()), |
| 204 | + instrumentationMethod.getName(), |
| 205 | + Type.getMethodDescriptor(instrumentationMethod), |
| 206 | + true |
| 207 | + ); |
| 208 | + } |
| 209 | + } |
| 210 | + |
| 211 | + // private static final Logger LOGGER = LogManager.getLogger(Instrumenter.class); |
| 212 | + |
| 213 | + public record ClassFileInfo(String fileName, byte[] bytecodes) {} |
| 214 | +} |
0 commit comments