/
TypeChecker.java
76 lines (62 loc) · 2.21 KB
/
TypeChecker.java
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package uk.co.thinkofdeath.vanillacord;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import java.util.LinkedList;
public class TypeChecker extends ClassVisitor {
private final boolean secure;
private int fCount = 0;
private boolean hasTID = false;
private boolean handshakeListener;
private boolean loginListener;
private boolean cbQuery, sbQuery;
String hsName;
String hsDesc;
public TypeChecker(boolean secure) {
super(Opcodes.ASM9);
this.secure = secure;
}
@Override
public FieldVisitor visitField(int access, String name, String descriptor, String signature, Object value) {
if ((access & Opcodes.ACC_STATIC) == 0) {
if (descriptor.equals("I")) hasTID = true;
++fCount;
}
return super.visitField(access, name, descriptor, signature, value);
}
@Override
public MethodVisitor visitMethod(int access, final String name, final String desc, String signature, String[] exceptions) {
return new MethodVisitor(api) {
@Override
public void visitLdcInsn(Object cst) {
if (secure) {
if (hasTID && "Payload may not be larger than 1048576 bytes".equals(cst)) {
cbQuery = fCount == 2;
sbQuery = fCount == 3;
}
}
if (cst instanceof String && (((String) cst).startsWith("multiplayer.disconnect.outdated_server") || ((String) cst).startsWith("multiplayer.disconnect.incompatible"))) {
handshakeListener = true;
hsName = name;
hsDesc = desc;
}
if ("Unexpected hello packet".equals(cst)) {
loginListener = true;
}
}
};
}
public boolean isHandshakeListener() {
return handshakeListener;
}
public boolean isLoginListener() {
return loginListener;
}
public boolean isClientQuery() {
return cbQuery;
}
public boolean isServerQuery() {
return sbQuery;
}
}