Make OnPacket return a result struct

protocol7/connection.go

@@ -95,17 +95,17 @@ func byteSliceToString(s []byte) string {
 	return string(s)
 }
 
-func (connection *Connection) OnSystemMsg(msg int, chunk chunk7.Chunk, u *packer.Unpacker, response *Packet) {
+func (connection *Connection) OnSystemMsg(msg int, chunk chunk7.Chunk, u *packer.Unpacker, result *PacketResult) {
 	if msg == network7.MsgSysMapChange {
 		fmt.Println("got map change")
-		response.Messages = append(response.Messages, messages7.Ready{})
+		result.Response.Messages = append(result.Response.Messages, messages7.Ready{})
 	} else if msg == network7.MsgSysConReady {
 		fmt.Println("got ready")
-		response.Messages = append(response.Messages, connection.MsgStartInfo())
+		result.Response.Messages = append(result.Response.Messages, connection.MsgStartInfo())
 	} else if msg == network7.MsgSysSnapSingle {
 		// tick := u.GetInt()
 		// fmt.Printf("got snap single tick=%d\n", tick)
-		response.Messages = append(response.Messages, messages7.CtrlKeepAlive{})
+		result.Response.Messages = append(result.Response.Messages, messages7.CtrlKeepAlive{})
 	} else {
 		fmt.Printf("unknown system message id=%d data=%x\n", msg, chunk.Data)
 	}
@@ -120,10 +120,10 @@ func (client *Connection) OnMotd(motd string) {
 	fmt.Printf("[motd] %s\n", motd)
 }
 
-func (client *Connection) OnGameMsg(msg int, chunk chunk7.Chunk, u *packer.Unpacker, response *Packet) {
+func (client *Connection) OnGameMsg(msg int, chunk chunk7.Chunk, u *packer.Unpacker, result *PacketResult) {
 	if msg == network7.MsgGameReadyToEnter {
 		fmt.Println("got ready to enter")
-		response.Messages = append(response.Messages, messages7.EnterGame{})
+		result.Response.Messages = append(result.Response.Messages, messages7.EnterGame{})
 	} else if msg == network7.MsgGameSvMotd {
 		motd := u.GetString()
 		if motd != "" {
@@ -145,7 +145,7 @@ func (client *Connection) OnGameMsg(msg int, chunk chunk7.Chunk, u *packer.Unpac
 	}
 }
 
-func (client *Connection) OnMessage(chunk chunk7.Chunk, response *Packet) {
+func (client *Connection) OnMessage(chunk chunk7.Chunk, result *PacketResult) {
 	// fmt.Printf("got chunk size=%d data=%v\n", chunk.Header.Size, chunk.Data)
 
 	if chunk.Header.Flags.Vital {
@@ -161,39 +161,48 @@ func (client *Connection) OnMessage(chunk chunk7.Chunk, response *Packet) {
 	msg >>= 1
 
 	if sys {
-		client.OnSystemMsg(msg, chunk, &u, response)
+		client.OnSystemMsg(msg, chunk, &u, result)
 	} else {
-		client.OnGameMsg(msg, chunk, &u, response)
+		client.OnGameMsg(msg, chunk, &u, result)
 	}
 }
 
-func (connection *Connection) OnPacketPayload(header []byte, data []byte, response *Packet) (*Packet, error) {
+func (connection *Connection) OnPacketPayload(data []byte, result *PacketResult) (*PacketResult, error) {
 	chunks := chunk7.UnpackChunks(data)
 
 	for _, c := range chunks {
-		connection.OnMessage(c, response)
+		connection.OnMessage(c, result)
 	}
-	return response, nil
+	return result, nil
 
 }
 
-// the response packet might be nil even if there is no error
+type PacketResult struct {
-func (connection *Connection) OnPacket(data []byte) (*Packet, error) {
+	// Suggested response that should be sent to the server
-	header := PacketHeader{}
+	// Will be *nil* if no response should be sent
-	headerRaw := data[:7]
+	Response *Packet
-	payload := data[7:]
-	header.Unpack(headerRaw)
-	response := connection.BuildResponse()
 
-	if header.Flags.Control {
+	// Incoming traffic from the server parsed into a Packet struct
+	Packet *Packet
+}
+
+func (connection *Connection) OnPacket(data []byte) (*PacketResult, error) {
+	result := &PacketResult{
+		Response: connection.BuildResponse(),
+		Packet:   &Packet{},
+	}
+	result.Packet.Header.Unpack(data[:7])
+	payload := data[7:]
+
+	if result.Packet.Header.Flags.Control {
 		ctrlMsg := int(payload[0])
 		fmt.Printf("got ctrl msg %d\n", ctrlMsg)
 		if ctrlMsg == network7.MsgCtrlToken {
 			copy(connection.ServerToken[:], payload[1:5])
-			response.Header.Token = connection.ServerToken
+			result.Response.Header.Token = connection.ServerToken
 			fmt.Printf("got server token %x\n", connection.ServerToken)
-			response.Messages = append(
+			result.Response.Messages = append(
-				response.Messages,
+				result.Response.Messages,
 				messages7.CtrlConnect{
 					Token: connection.ClientToken,
 				},
@@ -201,7 +210,7 @@ func (connection *Connection) OnPacket(data []byte) (*Packet, error) {
 		} else if ctrlMsg == network7.MsgCtrlAccept {
 			fmt.Println("got accept")
 			// TODO: don't hardcode info
-			response.Messages = append(response.Messages, messages7.Info{})
+			result.Response.Messages = append(result.Response.Messages, messages7.Info{})
 		} else if ctrlMsg == network7.MsgCtrlClose {
 			// TODO: get length from packet header to determine if a reason is set or not
 			// len(data) -> is 1400 (maxPacketLen)
@@ -214,14 +223,14 @@ func (connection *Connection) OnPacket(data []byte) (*Packet, error) {
 			fmt.Printf("unknown control message: %x\n", data)
 		}
 
-		if len(response.Messages) == 0 {
+		if len(result.Response.Messages) == 0 {
 			return nil, nil
 		}
 
-		return response, nil
+		return result, nil
 	}
 
-	if header.Flags.Compression {
+	if result.Packet.Header.Flags.Compression {
 		huff := huffman.Huffman{}
 		var err error
 		payload, err = huff.Decompress(payload)
@@ -231,6 +240,6 @@ func (connection *Connection) OnPacket(data []byte) (*Packet, error) {
 		}
 	}
 
-	response, err := connection.OnPacketPayload(headerRaw, payload, response)
+	result, err := connection.OnPacketPayload(payload, result)
-	return response, err
+	return result, err
 }

teeworlds.go

@@ -60,34 +60,33 @@ func main() {
 
 	go readNetwork(ch, conn)
 
-	packet := client.CtrlToken()
+	tokenPacket := client.CtrlToken()
-	conn.Write(packet.Pack(client))
+	conn.Write(tokenPacket.Pack(client))
 
 	for {
 		time.Sleep(10_000_000)
 		select {
 		case msg := <-ch:
-			packet, err = client.OnPacket(msg)
+			result, err := client.OnPacket(msg)
 			if err != nil {
 				panic(err)
 			}
-			if packet != nil {
+			if result.Response != nil {
 
 				// example of modifying outgoing traffic
-				for i, msg := range packet.Messages {
+				for i, msg := range result.Response.Messages {
 					if msg.MsgId() == network7.MsgCtrlConnect {
-						if connect, ok := packet.Messages[0].(messages7.CtrlConnect); ok {
+						if connect, ok := result.Response.Messages[0].(messages7.CtrlConnect); ok {
 							connect.Token = [4]byte{0xaa, 0xaa, 0xaa, 0xaa}
-							packet.Messages[i] = connect
+							result.Response.Messages[i] = connect
 						}
 					}
 				}
 
-				conn.Write(packet.Pack(client))
+				conn.Write(result.Response.Pack(client))
 			}
 		default:
 			// do nothing
 		}
 	}
-
 }