From 382e57a2cfdd615e138ad83bbcf5268ae08a9fa7 Mon Sep 17 00:00:00 2001
From: ftbsc <dev@fantabos.co>
Date: Wed, 8 Feb 2023 00:10:31 +0100
Subject: feat: initial work on packet patch

---
 src/main/java/ftbsc/bscv/patches/PacketPatch.java | 76 +++++++++++++++++++++++
 src/main/java/ftbsc/bscv/patches/TestPatch.java   | 51 ---------------
 2 files changed, 76 insertions(+), 51 deletions(-)
 create mode 100644 src/main/java/ftbsc/bscv/patches/PacketPatch.java
 delete mode 100644 src/main/java/ftbsc/bscv/patches/TestPatch.java

(limited to 'src/main/java/ftbsc')

diff --git a/src/main/java/ftbsc/bscv/patches/PacketPatch.java b/src/main/java/ftbsc/bscv/patches/PacketPatch.java
new file mode 100644
index 0000000..6588f0b
--- /dev/null
+++ b/src/main/java/ftbsc/bscv/patches/PacketPatch.java
@@ -0,0 +1,76 @@
+package ftbsc.bscv.patches;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.InsnNode;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.VarInsnNode;
+
+import ftbsc.bscv.BoSCoVicino;
+import ftbsc.lll.IInjector;
+import ftbsc.lll.tools.DescriptorBuilder;
+import ftbsc.lll.tools.InsnSequence;
+import ftbsc.lll.tools.PatternMatcher;
+import net.minecraft.network.IPacket;
+
+public class PacketPatch {
+
+	public static class LazyPacketCatcher {
+		private static LazyPacketCatcher INSTANCE = new LazyPacketCatcher();
+
+		public static LazyPacketCatcher getInstance() {
+			return LazyPacketCatcher.INSTANCE;
+		}
+
+		public void debug_pkt(IPacket<?> pkt) {
+			BoSCoVicino.LOGGER.info("got pkt : {}", pkt.toString());
+		}
+
+		public static void debug_static_pkt(IPacket<?> pkt) {
+			BoSCoVicino.LOGGER.info("got pkt : {}", pkt.toString());
+		}
+	}
+
+	public static class IncomingPacketInterceptor implements IInjector, Opcodes {
+		public String name()        { return "IncomingPacketInterceptor"; }
+		public String reason()      { return "add hook to intercept and alter/cancel incoming packets"; }
+		public String targetClass() { return "net.minecraft.network.NetworkManager"; }
+		public String methodName()  { return "channelRead0"; }
+		public String methodDesc() {
+			return
+				new DescriptorBuilder()
+					.setReturnType(void.class)
+					.addParameter("io.netty.channel.ChannelHandlerContext")
+					.addParameter("net.minecraft.network.IPacket")
+					.build();
+		}
+	
+		public void inject(ClassNode clazz, MethodNode main) {
+			// ALOAD, GETFIELD, INVOKEINTERFACE, IFEQ
+			AbstractInsnNode found = PatternMatcher.builder()
+				.opcodes(ALOAD, GETFIELD, INVOKEINTERFACE, IFEQ)
+				.ignoreFrames()
+				.ignoreLabels()
+				.ignoreLineNumbers()
+				.build()
+				.find(main)
+				.getLast();
+			
+			InsnSequence is = new InsnSequence();
+			is.add(new VarInsnNode(ALOAD, 2));
+			is.add(new MethodInsnNode(
+				INVOKESTATIC,
+				"ftbsc/bscv/patches/PacketPatch$LazyPacketCatcher",
+				"debug_static_pkt",
+				new DescriptorBuilder().addParameter("net.minecraft.network.IPacket").build()
+			));
+
+			main.instructions.insert(found, is);
+		}
+	}
+}
diff --git a/src/main/java/ftbsc/bscv/patches/TestPatch.java b/src/main/java/ftbsc/bscv/patches/TestPatch.java
deleted file mode 100644
index 5c6c152..0000000
--- a/src/main/java/ftbsc/bscv/patches/TestPatch.java
+++ /dev/null
@@ -1,51 +0,0 @@
-package ftbsc.bscv.patches;
-
-import org.objectweb.asm.Opcodes;
-import org.objectweb.asm.tree.ClassNode;
-import org.objectweb.asm.tree.InsnList;
-import org.objectweb.asm.tree.InsnNode;
-import org.objectweb.asm.tree.MethodNode;
-
-import ftbsc.lll.IInjector;
-
-/**
- * When working as intended, this patch will crash the game
- * as soon it finished loading with a NegativeArraySizeException.
- */
-public class TestPatch {
-
-	public static class FramerateFix implements IInjector, Opcodes {
-		public String name()        { return "FramerateFix"; }
-		public String targetClass() { return "net.minecraft.client.Minecraft"; }
-		public String methodName()  { return "func_213243_aC"; } // getFramerateLimit()
-		public String methodDesc()  { return "()I"; }
-	
-		public void inject(ClassNode clazz, MethodNode main) {
-			// InsnList insnList = new InsnList();
-			// insnList.add(new InsnNode(POP));
-			// main.instructions.insert(insnList);
-		}
-	}
-	
-
-	public static class TickPatch implements IInjector, Opcodes {
-		public String name()        { return "TickPatch"; }
-		public String targetClass() { return "net.minecraft.client.Minecraft"; }
-		public String methodName()  { return "func_71407_l"; } // tick()
-		public String methodDesc()  { return "()V"; }
-	
-		public void inject(ClassNode clazz, MethodNode main) {
-			// InsnList insnList = new InsnList();
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// insnList.add(new InsnNode(POP));
-			// main.instructions.insert(insnList);
-		}
-	}
-
-}
-- 
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