package d2remoteclient import ( "encoding/json" "fmt" "log" "net" "strings" "github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset" "github.com/OpenDiablo2/OpenDiablo2/d2core/d2hero" "github.com/OpenDiablo2/OpenDiablo2/d2networking" "github.com/OpenDiablo2/OpenDiablo2/d2networking/d2client/d2clientconnectiontype" "github.com/OpenDiablo2/OpenDiablo2/d2networking/d2netpacket" "github.com/OpenDiablo2/OpenDiablo2/d2networking/d2netpacket/d2netpackettype" "github.com/google/uuid" ) // RemoteClientConnection is the implementation of ClientConnection // for a remote client. type RemoteClientConnection struct { asset *d2asset.AssetManager heroState *d2hero.HeroStateFactory clientListener d2networking.ClientListener // The GameClient uniqueID string // Unique ID generated on construction tcpConnection *net.TCPConn // UDP connection to the server active bool // The connection is currently open } // Create constructs a new RemoteClientConnection // and returns a pointer to it. func Create(asset *d2asset.AssetManager) (*RemoteClientConnection, error) { heroStateFactory, err := d2hero.NewHeroStateFactory(asset) if err != nil { return nil, err } result := &RemoteClientConnection{ heroState: heroStateFactory, uniqueID: uuid.New().String(), } return result, nil } // Open runs serverListener() in a goroutine to continuously read UDP packets. // It also sends a PlayerConnectionRequestPacket packet to the server (see d2netpacket). func (r *RemoteClientConnection) Open(connectionString, saveFilePath string) error { if !strings.Contains(connectionString, ":") { connectionString += ":6669" } tcpAddress, err := net.ResolveTCPAddr("tcp", connectionString) if err != nil { return err } r.tcpConnection, err = net.DialTCP("tcp", nil, tcpAddress) if err != nil { return err } r.active = true go r.serverListener() log.Printf("Connected to server at %s", r.tcpConnection.RemoteAddr().String()) gameState := r.heroState.LoadHeroState(saveFilePath) packet := d2netpacket.CreatePlayerConnectionRequestPacket(r.GetUniqueID(), gameState) err = r.SendPacketToServer(packet) if err != nil { log.Print("RemoteClientConnection: error sending PlayerConnectionRequestPacket to server.") return err } return nil } // Close informs the server that this client has disconnected and sets // RemoteClientConnection.active to false. func (r *RemoteClientConnection) Close() error { r.active = false err := r.SendPacketToServer(d2netpacket.CreatePlayerDisconnectRequestPacket(r.GetUniqueID())) if err != nil { return err } return nil } // GetUniqueID returns RemoteClientConnection.uniqueID. func (r RemoteClientConnection) GetUniqueID() string { return r.uniqueID } // GetConnectionType returns an enum representing the connection type. // See: d2clientconnectiontype func (r RemoteClientConnection) GetConnectionType() d2clientconnectiontype.ClientConnectionType { return d2clientconnectiontype.LANClient } // SetClientListener sets RemoteClientConnection.clientListener to the given value. func (r *RemoteClientConnection) SetClientListener(listener d2networking.ClientListener) { r.clientListener = listener } // SendPacketToServer compresses the JSON encoding of a NetPacket and // sends it to the server. func (r *RemoteClientConnection) SendPacketToServer(packet d2netpacket.NetPacket) error { data, err := json.Marshal(packet) if err != nil { return err } if _, err = r.tcpConnection.Write(data); err != nil { return err } return nil } // serverListener runs a while loop, reading from the GameServer's TCP // connection. func (r *RemoteClientConnection) serverListener() { var packet d2netpacket.NetPacket decoder := json.NewDecoder(r.tcpConnection) for { err := decoder.Decode(&packet) if err != nil { log.Printf("failed to decode the packet, err: %v\n", err) return } p, err := r.decodeToPacket(packet.PacketType, string(packet.PacketData)) if err != nil { log.Println(packet.PacketType, err) } err = r.clientListener.OnPacketReceived(p) if err != nil { log.Println(packet.PacketType, err) } } } // bytesToJSON reads the packet type, decompresses the packet and returns a JSON string. func (r *RemoteClientConnection) bytesToJSON(buffer []byte) (string, d2netpackettype.NetPacketType, error) { packet, err := d2netpacket.UnmarshalNetPacket(buffer) if err != nil { return "", 0, err } return string(packet.PacketData), packet.PacketType, nil } // decodeToPacket unmarshals the JSON string into the correct struct // and returns a NetPacket declaring that struct. func (r *RemoteClientConnection) decodeToPacket(t d2netpackettype.NetPacketType, data string) (d2netpacket.NetPacket, error) { var np = d2netpacket.NetPacket{} var err error switch t { case d2netpackettype.GenerateMap: var p d2netpacket.GenerateMapPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} case d2netpackettype.MovePlayer: var p d2netpacket.MovePlayerPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} case d2netpackettype.UpdateServerInfo: var p d2netpacket.UpdateServerInfoPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} case d2netpackettype.AddPlayer: var p d2netpacket.AddPlayerPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} case d2netpackettype.CastSkill: var p d2netpacket.CastPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} case d2netpackettype.Ping: var p d2netpacket.PingPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} case d2netpackettype.PlayerDisconnectionNotification: var p d2netpacket.PlayerDisconnectRequestPacket if err = json.Unmarshal([]byte(data), &p); err != nil { break } np = d2netpacket.NetPacket{PacketType: t, PacketData: d2netpacket.MarshalPacket(p)} default: err = fmt.Errorf("RemoteClientConnection: unrecognized packet type: %v", t) } if err != nil { return np, err } return np, nil }