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Merge pull request #1559 from jjtParadox/asm-hubs-fix
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Fixed client crashing when receiving vanilla potion effect packets
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Mithion authored Jul 31, 2017
2 parents 528c68b + 84a46ea commit b5c9045
Showing 1 changed file with 138 additions and 9 deletions.
147 changes: 138 additions & 9 deletions src/main/java/am2/preloader/BytecodeTransformers.java
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,10 @@
import java.lang.reflect.Field;
import java.util.Iterator;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;

public class BytecodeTransformers implements IClassTransformer{

@Override
Expand Down Expand Up @@ -744,6 +748,22 @@ private byte[] alterS1DPacketEntityEffect(byte[] bytes, boolean is_obfuscated, S
ClassReader cr = new ClassReader(bytes);
ClassNode cn = new ClassNode();
cr.accept(cn, 0);

//debug
if (!is_obfuscated){
try{
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
cn.accept(cw);
File outDir = new File("asm/am2");
outDir.mkdirs();
DataOutputStream dout = new DataOutputStream(new FileOutputStream(new File(outDir, "SD1PacketEntityEffect_pre.class")));
dout.write(cw.toByteArray());
dout.flush();
dout.close();
}catch (Exception e){
e.printStackTrace();
}
}

// Minecraft r1.7.10:
// S1DPacketEntityEffect.java --> in.class
Expand Down Expand Up @@ -828,6 +848,10 @@ private byte[] alterS1DPacketEntityEffect(byte[] bytes, boolean is_obfuscated, S

String method1_searchinstruction_function = "readByte";
String method1_searchinstruction_desc = "()B";

// method used to check if receiving a vanilla or AM2 packet
String method1_checkinstruction_function = "readableBytes";
String method1_checkinstruction_desc = "()I";

// replacement class is the same
String method1_replaceinstruction_function = "readInt";
Expand All @@ -848,6 +872,9 @@ private byte[] alterS1DPacketEntityEffect(byte[] bytes, boolean is_obfuscated, S

String method2_searchinstruction_function = "writeByte";
String method2_searchinstruction_desc = "(I)Lio/netty/buffer/ByteBuf;";

// String method2_checkinstruction_function = "writableBytes";
// String method2_checkinstruction_desc = "()I";

// replacement class is the same
// so is the instruction, but we'll leave it as being explicitly defined just in case
Expand Down Expand Up @@ -940,11 +967,38 @@ private byte[] alterS1DPacketEntityEffect(byte[] bytes, boolean is_obfuscated, S
}

if (target != null && target2 != null){
MethodInsnNode new_readint = new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_replaceinstruction_function, method1_replaceinstruction_desc);
FieldInsnNode new_potion_id_variable = new FieldInsnNode(Opcodes.PUTFIELD, classname, potionID_intvar_name, potionID_intvar_desc);

mn.instructions.set(target, new_readint);
mn.instructions.set(target2, new_potion_id_variable);
InsnList new_if = new InsnList();
new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_checkinstruction_function, method1_checkinstruction_desc, false));
new_if.add(new IntInsnNode(Opcodes.BIPUSH, 7));
LabelNode elseLabel = new LabelNode();
new_if.add(new JumpInsnNode(Opcodes.IF_ICMPNE, elseLabel));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 0));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_replaceinstruction_function, method1_replaceinstruction_desc, false));
new_if.add(new FieldInsnNode(Opcodes.PUTFIELD, classname, potionID_intvar_name, potionID_intvar_desc));
LabelNode endIfLabel = new LabelNode();
new_if.add(new JumpInsnNode(Opcodes.GOTO, endIfLabel));
new_if.add(elseLabel);
new_if.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 0));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_searchinstruction_function, method1_searchinstruction_desc, false));
new_if.add(new FieldInsnNode(Opcodes.PUTFIELD, classname, potionID_intvar_name, potionID_intvar_desc));
new_if.add(endIfLabel);
new_if.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));

mn.instructions.insertBefore(target.getPrevious().getPrevious(), new_if);
mn.instructions.remove(target.getPrevious().getPrevious()); // ALOAD 0
mn.instructions.remove(target.getPrevious()); // ALOAD 1
mn.instructions.remove(target);
mn.instructions.remove(target2);

// MethodInsnNode new_readint = new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_replaceinstruction_function, method1_replaceinstruction_desc);
// FieldInsnNode new_potion_id_variable = new FieldInsnNode(Opcodes.PUTFIELD, classname, potionID_intvar_name, potionID_intvar_desc);
//
// mn.instructions.set(target, new_readint);
// mn.instructions.set(target2, new_potion_id_variable);
LogHelper.debug("Core: Success! Replaced opcodes!");
}
} else if (mn.name.equals(method2_name.getVal(is_obfuscated)) && mn.desc.equals(method2_desc.getVal(is_obfuscated))){
Expand All @@ -968,9 +1022,37 @@ private byte[] alterS1DPacketEntityEffect(byte[] bytes, boolean is_obfuscated, S
}

if (target != null && target2 != null){
// I don't think this advanced packet logic is even needed, as a server running AM2 would require AM2 on the client anyway.
// InsnList new_if = new InsnList();
// new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
// new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method2_searchinstruction_owner.getVal(is_obfuscated), method2_checkinstruction_function, method2_checkinstruction_desc, false));
// new_if.add(new IntInsnNode(Opcodes.BIPUSH, 7));
// LabelNode elseLabel = new LabelNode();
// new_if.add(new JumpInsnNode(Opcodes.IF_ICMPNE, elseLabel));
// new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
// new_if.add(new VarInsnNode(Opcodes.ALOAD, 0));
// new_if.add(new FieldInsnNode(Opcodes.GETFIELD, classname, potionID_intvar_name, potionID_intvar_desc));
// new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method2_searchinstruction_owner.getVal(is_obfuscated), method2_replaceinstruction_function, method2_replaceinstruction_desc, false));
// LabelNode endIfLabel = new LabelNode();
// new_if.add(new JumpInsnNode(Opcodes.GOTO, endIfLabel));
// new_if.add(elseLabel);
// new_if.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
// new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
// new_if.add(new VarInsnNode(Opcodes.ALOAD, 0));
// new_if.add(new FieldInsnNode(Opcodes.GETFIELD, classname, potionID_intvar_name, potionID_intvar_desc));
// new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method2_searchinstruction_owner.getVal(is_obfuscated), method2_searchinstruction_function, method2_searchinstruction_desc, false));
// new_if.add(endIfLabel);
// new_if.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
//
// mn.instructions.insertBefore(target.getPrevious().getPrevious(), new_if);
// mn.instructions.remove(target.getPrevious().getPrevious());
// mn.instructions.remove(target.getPrevious());
// mn.instructions.remove(target);
// mn.instructions.remove(target2);

FieldInsnNode new_potion_id_variable = new FieldInsnNode(Opcodes.GETFIELD, classname, potionID_intvar_name, potionID_intvar_desc);
MethodInsnNode new_writeint = new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method2_searchinstruction_owner.getVal(is_obfuscated), method2_replaceinstruction_function, method2_replaceinstruction_desc);

mn.instructions.set(target, new_potion_id_variable);
mn.instructions.set(target2, new_writeint);
LogHelper.debug("Core: Success! Replaced opcodes!");
Expand All @@ -988,6 +1070,21 @@ private byte[] alterS1DPacketEntityEffect(byte[] bytes, boolean is_obfuscated, S

ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
cn.accept(cw);

//debug
if (!is_obfuscated){
try{
File outDir = new File("asm/am2");
outDir.mkdirs();
DataOutputStream dout = new DataOutputStream(new FileOutputStream(new File(outDir, "SD1PacketEntityEffect_post.class")));
dout.write(cw.toByteArray());
dout.flush();
dout.close();
}catch (Exception e){
e.printStackTrace();
}
}

return cw.toByteArray();
}

Expand Down Expand Up @@ -1089,6 +1186,10 @@ private byte[] alterS1EPacketRemoveEntityEffect(byte[] bytes, boolean is_obfusca
// change from readUnsignedByte to readInt
String method1_searchinstruction_function = "readUnsignedByte";
String method1_searchinstruction_desc = "()S";

// method used to check if receiving a vanilla or AM2 packet
String method1_checkinstruction_function = "readableBytes";
String method1_checkinstruction_desc = "()I";

// replacement class is the same
String method1_replaceinstruction_function = "readInt";
Expand Down Expand Up @@ -1137,9 +1238,37 @@ private byte[] alterS1EPacketRemoveEntityEffect(byte[] bytes, boolean is_obfusca
}

if (target != null){
MethodInsnNode new_readint = new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_replaceinstruction_function, method1_replaceinstruction_desc);

mn.instructions.set(target, new_readint);
FieldInsnNode fieldNode = (FieldInsnNode)target.getNext();
InsnList new_if = new InsnList();
new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_checkinstruction_function, method1_checkinstruction_desc, false));
new_if.add(new IntInsnNode(Opcodes.BIPUSH, 8));
LabelNode elseLabel = new LabelNode();
new_if.add(new JumpInsnNode(Opcodes.IF_ICMPNE, elseLabel));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 0));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_replaceinstruction_function, method1_replaceinstruction_desc, false));
new_if.add(fieldNode.clone(null));
LabelNode endIfLabel = new LabelNode();
new_if.add(new JumpInsnNode(Opcodes.GOTO, endIfLabel));
new_if.add(elseLabel);
new_if.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 0));
new_if.add(new VarInsnNode(Opcodes.ALOAD, 1));
new_if.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_searchinstruction_function, method1_searchinstruction_desc, false));
new_if.add(fieldNode.clone(null));
new_if.add(endIfLabel);
new_if.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));

mn.instructions.insertBefore(target.getPrevious().getPrevious(), new_if);
mn.instructions.remove(target.getPrevious().getPrevious()); // ALOAD 0
mn.instructions.remove(target.getPrevious()); // ALOAD 1
mn.instructions.remove(target);
mn.instructions.remove(fieldNode); // PUTFIELD

// MethodInsnNode new_readint = new MethodInsnNode(Opcodes.INVOKEVIRTUAL, method1_searchinstruction_owner.getVal(is_obfuscated), method1_replaceinstruction_function, method1_replaceinstruction_desc);
//
// mn.instructions.set(target, new_readint);
LogHelper.debug("Core: Success! Replaced opcodes!");
}
} else if (mn.name.equals(method2_name.getVal(is_obfuscated)) && mn.desc.equals(method2_desc.getVal(is_obfuscated))){
Expand Down

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