/*
* 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 java.util.HashSet;
import scouter.agent.ClassDesc;
import scouter.agent.Configure;
import scouter.agent.Logger;
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;
public class HttpServiceASM implements IASM, Opcodes {
public HashSet<String> servlets = new HashSet<String>();
public HttpServiceASM() {
servlets.add("javax/servlet/http/HttpServlet");
servlets.add("weblogic/servlet/jsp/JspBase");
}
public ClassVisitor transform(ClassVisitor cv, String className, ClassDesc classDesc) {
if (Configure.getInstance()._hook_serivce_enabled == false) {
return cv;
}
if (servlets.contains(className)) {
return new HttpServiceCV(cv, className);
}
for (int i = 0; classDesc.interfaces != null && i < classDesc.interfaces.length; i++) {
if ("javax/servlet/Filter".equals(classDesc.interfaces[i])) {
return new HttpServiceCV(cv, className);
}
}
return cv;
}
}
class HttpServiceCV extends ClassVisitor implements Opcodes {
private static String TARGET_SERVICE = "service";
private static String TARGET_DOFILTER = "doFilter";
private static String TARGET_SIGNATURE = "(Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;";
private String className;
public HttpServiceCV(ClassVisitor cv, String className) {
super(ASM4, cv);
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) {
return mv;
}
if (desc.startsWith(TARGET_SIGNATURE)) {
if (TARGET_SERVICE.equals(name)) {
Logger.println("A103", "HTTP " + className);
return new HttpServiceMV(access, desc, mv, true);
} else if (TARGET_DOFILTER.equals(name)) {
Logger.println("A104", "FILTER " + className);
return new HttpServiceMV(access, desc, mv, false);
}
}
return mv;
}
}
// ///////////////////////////////////////////////////////////////////////////
class HttpServiceMV extends LocalVariablesSorter implements Opcodes {
private static final String TRACEMAIN = TraceMain.class.getName().replace('.', '/');
private final static String START_SERVICE = "startHttpService";
private final static String START_FILTER = "startHttpFilter";
private static final String START_SIGNATURE = "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;";
private final static String END_METHOD = "endHttpService";
private static final String END_SIGNATURE = "(Ljava/lang/Object;Ljava/lang/Throwable;)V";
private final static String REJECT = "reject";
private static final String REJECT_SIGNATURE = "(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;";
private Label startFinally = new Label();
private boolean httpservlet;
public HttpServiceMV(int access, String desc, MethodVisitor mv, boolean httpservlet) {
super(ASM4, access, desc, mv);
this.httpservlet = httpservlet;
}
private int statIdx;
@Override
public void visitCode() {
mv.visitVarInsn(Opcodes.ALOAD, 1);
mv.visitVarInsn(Opcodes.ALOAD, 2);
if (httpservlet) {
mv.visitMethodInsn(Opcodes.INVOKESTATIC, TRACEMAIN, START_SERVICE, START_SIGNATURE, false);
} else {
mv.visitMethodInsn(Opcodes.INVOKESTATIC, TRACEMAIN, START_FILTER, START_SIGNATURE, false);
}
statIdx = newLocal(Type.getType(Object.class));
mv.visitVarInsn(Opcodes.ASTORE, statIdx);
mv.visitLabel(startFinally);
mv.visitVarInsn(Opcodes.ALOAD, statIdx);
mv.visitVarInsn(Opcodes.ALOAD, 1);
mv.visitVarInsn(Opcodes.ALOAD, 2);
mv.visitMethodInsn(Opcodes.INVOKESTATIC, TRACEMAIN, REJECT, REJECT_SIGNATURE, false);
Label end = new Label();
mv.visitJumpInsn(IFNULL, end);
mv.visitInsn(Opcodes.RETURN);
mv.visitLabel(end);
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);
}
}