POC: inspect incoming traffic

messages7/ctrl_accept.go

@@ -0,0 +1,39 @@
+package messages7
+
+import (
+	"slices"
+
+	"github.com/teeworlds-go/teeworlds/network7"
+	"github.com/teeworlds-go/teeworlds/packer"
+)
+
+type CtrlAccept struct {
+	Token [4]byte
+}
+
+func (msg CtrlAccept) MsgId() int {
+	return network7.MsgCtrlAccept
+}
+
+func (msg CtrlAccept) MsgType() network7.MsgType {
+	return network7.TypeControl
+}
+
+func (msg CtrlAccept) System() bool {
+	return false
+}
+
+func (msg CtrlAccept) Vital() bool {
+	return false
+}
+
+func (msg CtrlAccept) Pack() []byte {
+	return slices.Concat(
+		[]byte{network7.MsgCtrlAccept},
+		msg.Token[:],
+		[]byte{512: 0},
+	)
+}
+
+func (msg *CtrlAccept) Unpack(u *packer.Unpacker) {
+}

messages7/sv_chat.go

@@ -0,0 +1,47 @@
+package messages7
+
+import (
+	"slices"
+
+	"github.com/teeworlds-go/teeworlds/network7"
+	"github.com/teeworlds-go/teeworlds/packer"
+)
+
+type SvChat struct {
+	Mode     int
+	ClientId int
+	TargetId int
+	Message  string
+}
+
+func (msg SvChat) MsgId() int {
+	return network7.MsgGameSvChat
+}
+
+func (msg SvChat) MsgType() network7.MsgType {
+	return network7.TypeNet
+}
+
+func (msg SvChat) System() bool {
+	return false
+}
+
+func (msg SvChat) Vital() bool {
+	return true
+}
+
+func (msg SvChat) Pack() []byte {
+	return slices.Concat(
+		packer.PackInt(msg.Mode),
+		packer.PackInt(msg.ClientId),
+		packer.PackInt(msg.TargetId),
+		packer.PackStr(msg.Message),
+	)
+}
+
+func (msg *SvChat) Unpack(u *packer.Unpacker) {
+	msg.Mode = u.GetInt()
+	msg.ClientId = u.GetInt()
+	msg.TargetId = u.GetInt()
+	msg.Message = u.GetString()
+}

protocol7/connection.go

@@ -111,9 +111,9 @@ func (connection *Connection) OnSystemMsg(msg int, chunk chunk7.Chunk, u *packer
 	}
 }
 
-func (client *Connection) OnChatMessage(mode int, clientId int, targetId int, message string) {
+func (client *Connection) OnChatMessage(msg *messages7.SvChat) {
-	name := client.Players[clientId].Info.Name
+	name := client.Players[msg.ClientId].Info.Name
-	fmt.Printf("[chat] <%s> %s\n", name, message)
+	fmt.Printf("[chat] <%s> %s\n", name, msg.Message)
 }
 
 func (client *Connection) OnMotd(motd string) {
@@ -131,11 +131,10 @@ func (client *Connection) OnGameMsg(msg int, chunk chunk7.Chunk, u *packer.Unpac
 			client.OnMotd(motd)
 		}
 	} else if msg == network7.MsgGameSvChat {
-		mode := u.GetInt()
+		chat := &messages7.SvChat{}
-		clientId := u.GetInt()
+		chat.Unpack(u)
-		targetId := u.GetInt()
+		client.OnChatMessage(chat)
-		message := u.GetString()
+		result.Packet.Messages = append(result.Packet.Messages, chat)
-		client.OnChatMessage(mode, clientId, targetId, message)
 	} else if msg == network7.MsgGameSvClientInfo {
 		clientId := packer.UnpackInt(chunk.Data[1:])
 		client.Players[clientId].Info.Unpack(u)
@@ -202,6 +201,7 @@ func (connection *Connection) OnPacket(data []byte) (*PacketResult, error) {
 			copy(connection.ServerToken[:], payload[1:5])
 			result.Response.Header.Token = connection.ServerToken
 			fmt.Printf("got server token %x\n", connection.ServerToken)
+			result.Packet.Messages = append(result.Packet.Messages, &messages7.CtrlToken{Token: connection.ServerToken})
 			result.Response.Messages = append(
 				result.Response.Messages,
 				&messages7.CtrlConnect{
@@ -210,6 +210,7 @@ func (connection *Connection) OnPacket(data []byte) (*PacketResult, error) {
 			)
 		} else if ctrlMsg == network7.MsgCtrlAccept {
 			fmt.Println("got accept")
+			result.Packet.Messages = append(result.Packet.Messages, &messages7.CtrlAccept{})
 			// TODO: don't hardcode info
 			result.Response.Messages = append(result.Response.Messages, &messages7.Info{})
 		} else if ctrlMsg == network7.MsgCtrlClose {

teeworlds.go

@@ -73,12 +73,26 @@ func main() {
 			}
 			if result.Response != nil {
 
+				// example of inspecting incoming trafic
+				for i, msg := range result.Packet.Messages {
+					if msg.MsgId() == network7.MsgGameSvChat {
+						var chat *messages7.SvChat
+						var ok bool
+						if chat, ok = result.Packet.Messages[i].(*messages7.SvChat); ok {
+							fmt.Printf("got chat msg: %s\n", chat.Message)
+
+							// modify chat if this was a proxy
+							result.Response.Messages[i] = chat
+						}
+					}
+				}
+
 				// example of modifying outgoing traffic
 				for i, msg := range result.Response.Messages {
 					if msg.MsgId() == network7.MsgCtrlConnect {
 						var connect *messages7.CtrlConnect
 						var ok bool
-						if connect, ok = result.Response.Messages[0].(*messages7.CtrlConnect); ok {
+						if connect, ok = result.Response.Messages[i].(*messages7.CtrlConnect); ok {
 							connect.Token = [4]byte{0xaa, 0xaa, 0xaa, 0xaa}
 							result.Response.Messages[i] = connect
 						}