Remove channel for C2S packets in bot

Author: ubap

internal/bot/bot.go

@@ -14,8 +14,6 @@ type Bot struct {
 
 	state *state.GameState
 
-	UserActions chan []byte // packets sent by client to server
-
 	clientConn protocol.Connection
 	serverConn protocol.Connection
 	stopChan   chan struct{}  // The broadcast channel
@@ -27,8 +25,6 @@ func NewBot(state *state.GameState, clientConn protocol.Connection, serverConn p
 	return &Bot{
 		state: state,
 
-		UserActions: make(chan []byte, 1024),
-
 		clientConn: clientConn,
 		serverConn: serverConn,
 		stopChan:   make(chan struct{}),
@@ -39,7 +35,6 @@ func (b *Bot) Start() {
 	log.Println("[Bot] Engine started")
 
 	b.runModule("LightHack", b.loopLightHack)
-	b.runModule("HandleUserAction", b.loopHandleUserAction)
 	b.runModule("Fishing", b.loopFishing)
 	b.runModule("UI", b.loopWebUI)
 }
@@ -100,29 +95,6 @@ func (b *Bot) loopLightHack() {
 	}
 }
 
-func (b *Bot) loopHandleUserAction() {
-	for {
-		select {
-		case <-b.stopChan:
-			return
-		case packet := <-b.UserActions:
-			b.handleUserAction(packet)
-		}
-	}
-}
-
-func (b *Bot) handleUserAction(rawMsg []byte) {
-	packetReader := protocol.NewPacketReader(rawMsg)
-	packet, err := packets.ReadAndParseC2S(packetReader)
-	if err != nil {
-		return
-	}
-	switch p := packet.(type) {
-	case *packets.LookRequest:
-		log.Printf("User looked at item ID: %d", p.ItemId)
-	}
-}
-
 // InterceptS2CPacket has to return immediately.
 func (b *Bot) InterceptS2CPacket(data []byte) ([]byte, error) {
 	pr := protocol.NewPacketReader(data)
@@ -136,3 +108,28 @@ func (b *Bot) InterceptS2CPacket(data []byte) ([]byte, error) {
 	}
 	return data, nil
 }
+
+// InterceptC2SPacket has to return immediately.
+func (b *Bot) InterceptC2SPacket(data []byte) ([]byte, error) {
+	pr := protocol.NewPacketReader(data)
+	firstByte, err := pr.PeekUint8()
+	if err != nil {
+		log.Println("[Bot] InterceptC2SPacket err:", err)
+		return data, err
+	}
+	opcode := packets.C2SOpcode(firstByte)
+	switch opcode {
+	case packets.C2SLookRequest:
+		b.handleLookRequest(pr)
+	}
+	return data, nil
+}
+
+func (b *Bot) handleLookRequest(pr *protocol.PacketReader) {
+	p, err := packets.ParseLookRequest(pr)
+	if err != nil {
+		log.Printf("Failed to parse look request: %v", err)
+		return
+	}
+	log.Printf("User looked at item ID: %d", p.ItemId)
+}

internal/game/game_handler.go

@@ -84,16 +84,14 @@ func (g *GameSession) loopC2S() {
 			g.ErrChan <- fmt.Errorf("C2S Read: %w", err)
 			return
 		}
-		if err := g.ServerConn.WriteMessage(rawMsg); err != nil {
-			g.ErrChan <- fmt.Errorf("C2S Write: %w", err)
+		patchedMsg, err := g.Bot.InterceptC2SPacket(rawMsg)
+		if err != nil {
+			g.ErrChan <- fmt.Errorf("C2S Patch: %w", err)
 			return
 		}
-
-		select {
-		case g.Bot.UserActions <- rawMsg:
-			// Successfully queued for processing
-		default:
-			// If the queue is full, this packet is dropped.
+		if err := g.ClientConn.WriteMessage(patchedMsg); err != nil {
+			g.ErrChan <- fmt.Errorf("C2S Write: %w", err)
+			return
 		}
 	}
 }

internal/protocol/packet_reader.go

@@ -140,6 +140,27 @@ func (pr *PacketReader) ReadAll() []byte {
 	return buf
 }
 
+func (pr *PacketReader) PeekUint8() (uint8, error) {
+	if pr.reader.Len() < 1 {
+		return 0, io.EOF
+	}
+
+	// 1. Get the current position without moving the cursor
+	currentOffset, err := pr.reader.Seek(0, io.SeekCurrent)
+	if err != nil {
+		return 0, err
+	}
+
+	// 2. ReadAt reads from the specific offset and does not advance the reader
+	var b [1]byte
+	_, err = pr.reader.ReadAt(b[:], currentOffset)
+	if err != nil {
+		return 0, err
+	}
+
+	return b[0], nil
+}
+
 func (pr *PacketReader) PeekUint16() (uint16, error) {
 	if pr.reader.Len() < 2 {
 		return 0, io.EOF