/*
* Copyright 2015 the original author or authors.
* @https://github.com/scouter-project/scouter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package scouter.agent.asm;
import scouter.agent.ClassDesc;
import scouter.agent.Configure;
import scouter.agent.asm.util.AsmUtil;
import scouter.agent.asm.util.HookingSet;
import scouter.agent.netio.data.DataProxy;
import scouter.agent.trace.TraceMain;
import scouter.org.objectweb.asm.ClassVisitor;
import scouter.org.objectweb.asm.Label;
import scouter.org.objectweb.asm.MethodVisitor;
import scouter.org.objectweb.asm.Opcodes;
import scouter.org.objectweb.asm.Type;
import scouter.org.objectweb.asm.commons.LocalVariablesSorter;
import scouter.util.StringUtil;
import java.util.ArrayList;
import java.util.List;
public class MethodASM implements IASM, Opcodes {
private static List<String> defaultPatterns = new ArrayList<String>();
private static List<String> defaultExcludePatterns = new ArrayList<String>();
private Configure conf = Configure.getInstance();
private List<HookingSet> target;
private List<HookingSet> excludeTarget;
public MethodASM() {
String patterns = buildPatterns(conf.hook_method_patterns, defaultPatterns);
String excludPatterns = buildPatterns(conf.hook_method_exclude_patterns, defaultExcludePatterns);
target = HookingSet.getHookingMethodSet(patterns);
excludeTarget = HookingSet.getHookingMethodSet(excludPatterns);
}
public static void addPatterns(String methodPattern) {
defaultPatterns.add(methodPattern);
}
public static void addExcludePatterns(String methodPattern) {
defaultExcludePatterns.add(methodPattern);
}
private String buildPatterns(String patterns, List<String> patternsList) {
for(int i=0; i<patternsList.size(); i++) {
if(StringUtil.isNotEmpty(StringUtil.trim(patterns))) {
patterns = patterns + "," + patternsList.get(i);
} else {
patterns = patternsList.get(i);
}
}
return patterns;
}
public ClassVisitor transform(ClassVisitor cv, String className, ClassDesc classDesc) {
if (conf._hook_methods_enabled == false) {
return cv;
}
if (target.size() == 0)
return cv;
if (conf.isIgnoreMethodClass(className))
return cv;
for (int i = 0; i < target.size(); i++) {
HookingSet mset = target.get(i);
if (mset.classMatch.include(className)) {
return new MethodCV(cv, mset, excludeTarget, className);
}
}
return cv;
}
}
class MethodCV extends ClassVisitor implements Opcodes {
public String className;
private HookingSet mset;
private List<HookingSet> excludeTarget;
public MethodCV(ClassVisitor cv, HookingSet mset, List<HookingSet> excludeTarget, String className) {
super(ASM4, cv);
this.mset = mset;
this.excludeTarget = excludeTarget;
this.className = className;
}
@Override
public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
if (mv == null || mset.isA(name, desc) == false) {
return mv;
}
if (AsmUtil.isSpecial(name)) {
return mv;
}
// check exclude method set
for (int i = 0; i < excludeTarget.size(); i++) {
HookingSet excludeSet = excludeTarget.get(i);
if (excludeSet.classMatch.include(className)) {
if (excludeSet.isA(name, desc)) {
return mv;
}
}
}
Configure conf = Configure.getInstance();
boolean isPublic = conf.hook_method_access_public_enabled;
boolean isProtected = conf.hook_method_access_protected_enabled;
boolean isPrivate = conf.hook_method_access_private_enabled;
boolean isNone = conf.hook_method_access_none_enabled;
//lambda method
if(conf.hook_method_lambda_enable && (access & Opcodes.ACC_SYNTHETIC) == Opcodes.ACC_SYNTHETIC && name.indexOf("lambda$") == 0) {
//if lambda method with hook_method_lambda_enabled then go on without method accessor check
} else { // non-lambda method
switch (access & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED | Opcodes.ACC_PRIVATE)) {
case Opcodes.ACC_PUBLIC:
if (isPublic == false)
return mv;
break;
case Opcodes.ACC_PROTECTED:
if (isProtected == false)
return mv;
break;
case Opcodes.ACC_PRIVATE:
if (isPrivate == false)
return mv;
break;
default:
if (isNone == false)
return mv;
break;
}
}
// check prefix, to ignore simple method such as getter,setter
if (conf.isIgnoreMethodPrefix(name))
return mv;
String fullname = AsmUtil.makeMethodFullName(className, name, desc);
int fullname_hash = DataProxy.sendMethodName(fullname);
return new MethodMV(access, desc, mv, fullname, fullname_hash);
}
}
class MethodMV extends LocalVariablesSorter implements Opcodes {
private static final String TRACEMAIN = TraceMain.class.getName().replace('.', '/');
private final static String START_METHOD = "startMethod";
private static final String START_SIGNATURE = "(ILjava/lang/String;)Ljava/lang/Object;";
private final static String END_METHOD = "endMethod";
private static final String END_SIGNATURE = "(Ljava/lang/Object;Ljava/lang/Throwable;)V";
private Label startFinally = new Label();
public MethodMV(int access, String desc, MethodVisitor mv, String fullname, int fullname_hash) {
super(ASM4, access, desc, mv);
this.fullname = fullname;
this.fullname_hash = fullname_hash;
}
private int fullname_hash;
private String fullname;
private int statIdx;
@Override
public void visitCode() {
AsmUtil.PUSH(mv, fullname_hash);
mv.visitLdcInsn(fullname);
mv.visitMethodInsn(Opcodes.INVOKESTATIC, TRACEMAIN, START_METHOD, START_SIGNATURE, false);
statIdx = newLocal(Type.getType(Object.class));
mv.visitVarInsn(Opcodes.ASTORE, statIdx);
mv.visitLabel(startFinally);
mv.visitCode();
}
@Override
public void visitInsn(int opcode) {
if ((opcode >= IRETURN && opcode <= RETURN)) {
mv.visitVarInsn(Opcodes.ALOAD, statIdx);
mv.visitInsn(Opcodes.ACONST_NULL);
mv.visitMethodInsn(Opcodes.INVOKESTATIC, TRACEMAIN, END_METHOD, END_SIGNATURE, false);
}
mv.visitInsn(opcode);
}
@Override
public void visitMaxs(int maxStack, int maxLocals) {
Label endFinally = new Label();
mv.visitTryCatchBlock(startFinally, endFinally, endFinally, null);
mv.visitLabel(endFinally);
mv.visitInsn(DUP);
int errIdx = newLocal(Type.getType(Throwable.class));
mv.visitVarInsn(Opcodes.ASTORE, errIdx);
mv.visitVarInsn(Opcodes.ALOAD, statIdx);
mv.visitVarInsn(Opcodes.ALOAD, errIdx);
mv.visitMethodInsn(Opcodes.INVOKESTATIC, TRACEMAIN, END_METHOD, END_SIGNATURE, false);
mv.visitInsn(ATHROW);
mv.visitMaxs(maxStack + 8, maxLocals + 2);
}
}