Delphi Indy TCP 连接到 RECON

Question

我正在尝试弄清楚如何使用远程控制台建立连接和身份验证。

本维基 Wiki 1还有这个Wiki 2告诉我我需要构建一个数据包并将其发送到 RECON，但我不知道该怎么做......

我是网络新手，但由于我在那里搜索，所以我构建了这个:

procedure TForm1.Button1Click(Sender: TObject);
begin
  IdTCPClient1.Host:= '127.0.0.1';
  IdTCPClient1.Port:= 20001;
  IdTCPClient1.Connect;
  IdTcpClient1.IOHandler.Writeln('1234');
  ShowMessage(IdTcpClient1.IOHandler.ReadLn);
end; 

我被困在那里，1234 是侦察密码和它返回的消息:连接正常关闭...

最后，如何才能登录成功呢？至少发送一个命令“list”，下一步将实时接收控制台日志？

谢谢

Answer 1

您的代码未实现 Source RECON protocol Minecraft 命令在其上运行。您不能只向服务器发送任意数据，它必须被正确地构造。

尝试更像这样的东西:

const
  SERVERDATA_AUTH = 3;
  SERVERDATA_AUTH_RESPONSE = 2;
  SERVERDATA_EXECCOMMAND = 2;
  SERVERDATA_RESPONSE_VALUE = 0;

procedure TForm1.Button1Click(Sender: TObject);
begin
  IdTCPClient1.Host := '127.0.0.1';
  IdTCPClient1.Port := 20001;
  IdTCPClient1.Connect;
  SendRECONLogin('1234');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  IdTCPClient1.Disconnect;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  SendRECONCommand('list');
end;

procedure TForm1.IdTCPClient1Connect(Sender: TObject);
begin
  Timer1.Enabled := True;
end; 

procedure TForm1.IdTCPClient1Disconnect(Sender: TObject);
begin
  Timer1.Enabled := False;
end; 

procedure TForm1.Timer1Timer(Sender: TObject);
var
  RespID: Int32;
  PktType: Int32;
  Payload: string;
begin
  try
    if not IdTCPClient1.Connected then
      Exit;

    if IdTCPClient1.IOHandler.InputBufferIsEmpty then
    begin
      IdTCPClient1.IOHandler.CheckForDataOnSource(0);
      IdTCPClient1.IOHandler.CheckForDisconnect(True, False);
      if IdTCPClient1.IOHandler.InputBufferIsEmpty then Exit;
    end;

    RespID := ReadRECONPacket(PktType, Payload);
    case PktType of
      SERVERDATA_AUTH_RESPONSE: begin
        if RespID = -1 then begin
          // authentication failed...
          IdTCPClient1.Disconnect;
        end else begin
          // authentication successful...
        end;
      end;
      SERVERDATA_RESPONSE_VALUE: begin
        // match RespID to previously sent ReqID
        // and handle Payload as needed...
      end;
    end;
  except
    IdTCPClient1.Disconnect;
  end;
end;

var
  gReqID: Int32 = 0;

function TForm1.SendRECONPacket(PktType: Int32; const Payload: string = ''): Int32;
var
  Bytes: TIdBytes;
begin
  Bytes := IndyTextEncoding_ASCII.GetBytes(Payload);
  try
    if gReqID < MaxInt then Inc(gReqID)
    else gReqID := 1;
    Result := gReqID;

    IdTCPClient1.IOHandler.WriteBufferOpen;
    try
      IdTCPClient1.IOHandler.Write(Int32(Length(Bytes)+10), False);
      IdTCPClient1.IOHandler.Write(Result, False);
      IdTCPClient1.IOHandler.Write(PktType, False);
      IdTCPClient1.IOHandler.Write(Bytes);
      IdTCPClient1.IOHandler.Write(UInt16(0), False);
      IdTCPClient1.IOHandler.WriteBufferClose;
    except
      IdTCPClient1.IOHandler.WriteBufferCancel;
      raise;
    end;
  except
    IdTCPClient1.Disconnect;
    raise;
  end;    
end;

function TForm1.SendRECONLogin(const Password: String): Int32;
begin
  Result := SendRECONPacket(SERVERDATA_AUTH, Password);
end;

function TForm1.SendRECONCommand(const Cmd: String): Int32;
begin
  Result := SendRECONPacket(SERVERDATA_EXECCOMMAND, Cmd);
end;

function TForm1.ReadRECONPacket(var PktType: Integer; var Payload: String): Int32;
var
  Len: Int32;
begin
  try
    Len     := IdTCPClient1.IOHandler.ReadInt32(False);
    Result  := IdTCPClient1.IOHandler.ReadInt32(False);
    PktType := IdTCPClient1.IOHandler.ReadInt32(False);
    Payload := IdTCPClient1.IOHandler.ReadString(Len-10, IndyTextEncoding_ASCII);
    IdTCPClient1.IOHandler.Discard(2);
  except
    IdTCPClient1.Disconnect;
    raise;
  end;
end;

请注意，RCON 是一个异步协议(protocol)。每个命令都包含一个请求 ID，它会在响应中回显。可以将多个命令发送到服务器，而无需等待它们的回复。这就是我编写 SendRCONPacket() 以返回实际使用的请求 ID 的原因，因此您可以将其保存在某处并将其与 ReadRCONPacket() 返回的响应 ID 相匹配。上面代码中 TTimer 的使用只是一个如何从服务器接收未经请求的数据的示例。在生产代码中，我建议使用专用读取线程而不是计时器，并让线程在数据包到达时通知其余代码。

如果您不打算并行处理多个命令，那么您可以完全摆脱计时器并改为做更多类似的事情:

const
  SERVERDATA_AUTH = 3;
  SERVERDATA_AUTH_RESPONSE = 2;
  SERVERDATA_EXECCOMMAND = 2;
  SERVERDATA_RESPONSE_VALUE = 0;

procedure TForm1.Button1Click(Sender: TObject);
var
  Reply: string;
begin
  IdTCPClient1.Host := '127.0.0.1';
  IdTCPClient1.Port := 20001;
  IdTCPClient1.Connect;
  SendRECONLogin('1234');
  ShowMessage('Conectado exitosamente');
  Reply := SendRECONCommand('say Hello');
  // use Reply as needed...
  ShowMessage(Reply);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  IdTCPClient1.Disconnect;
end;

procedure TForm1.Button3Click(Sender: TObject);
var
  Reply: string;
begin
  Reply := SendRECONCommand('list');
  // use Reply as needed...
  ShowMessage(Reply);
end;

var
  gReqID: Int32 = 0;

function TForm1.SendRECONPacket(PktType: Int32; const Payload: string = ''): Int32;
var
  Bytes: TIdBytes;
begin
  Bytes := IndyTextEncoding_ASCII.GetBytes(Payload);
  try
    if gReqID < MaxInt then Inc(gReqID)
    else gReqID := 1;
    Result := gReqID;

    IdTCPClient1.IOHandler.WriteBufferOpen;
    try
      IdTCPClient1.IOHandler.Write(Int32(Length(Bytes)+10), False);
      IdTCPClient1.IOHandler.Write(Result, False);
      IdTCPClient1.IOHandler.Write(PktType, False);
      IdTCPClient1.IOHandler.Write(Bytes);
      IdTCPClient1.IOHandler.Write(UInt16(0), False);
      IdTCPClient1.IOHandler.WriteBufferClose;
    except
      IdTCPClient1.IOHandler.WriteBufferCancel;
      raise;
    end;
  except
    IdTCPClient1.Disconnect;
    raise;
  end;
end;

procedure TForm1.SendRECONLogin(const Password: String);
var
  ReqID, RespID, PktType: Int32;
  Reply: String;
begin
  {
  From https://developer.valvesoftware.com/wiki/Source_RCON_Protocol#SERVERDATA_AUTH_RESPONSE:

  When the server receives an auth request, it will respond with an empty SERVERDATA_RESPONSE_VALUE,
  followed immediately by a SERVERDATA_AUTH_RESPONSE indicating whether authentication succeeded or
  failed. Note that the status code is returned in the packet id field, so when pairing the response with the
  original auth request, you may need to look at the packet id of the preceeding SERVERDATA_RESPONSE_VALUE.
  }

  // in testing, there is no empty SERVERDATA_RESPONSE_VALUE sent before SERVERDATA_AUTH_RESPONSE!

  ReqID := SendRECONPacket(SERVERDATA_AUTH, Password);

  RespID := ReadRECONPacket(PktType, Reply);
  if PktType = SERVERDATA_RESPONSE_VALUE then
  begin
    if RespID <> ReqID then
      raise Exception.Create('Received unexpected packet');
    RespID := ReadRECONPacket(PktType, Reply);
  end;

  if PktType <> SERVERDATA_AUTH_RESPONSE then
    raise Exception.Create('Received unexpected packet');

  if RespID <> ReqID then
  begin
    if RespID <> -1 then
      raise Exception.Create('Received unexpected packet');
    raise Exception.Create('Authentication failed');
  end;
end;

function TForm1.SendRECONCommand(const Cmd: String): string;
var
  ReqID, TermReqID, RespID, PktType: Int32;
  Reply: string;
begin
  {
  From https://developer.valvesoftware.com/wiki/Source_RCON_Protocol#Multiple-packet_Responses:

  Most responses are small enough to fit within the maximum possible packet size of 4096 bytes.
  However, a few commands such as cvarlist and, occasionally, status produce responses too
  long to be sent in one response packet. When this happens, the server will split the response
  into multiple SERVERDATA_RESPONSE_VALUE packets. Unfortunately, it can be difficult to
  accurately determine from the first packet alone whether the response has been split.

  One common workaround is for the client to send an empty SERVERDATA_RESPONSE_VALUE
  packet after every SERVERDATA_EXECCOMMAND request. Rather than throwing out the
  erroneous request, SRCDS mirrors it back to the client, followed by another RESPONSE_VALUE
  packet containing 0x0000 0001 0000 0000 in the packet body field. Because SRCDS always
  responds to requests in the order it receives them, receiving a response packet with an empty
  packet body guarantees that all of the meaningful response packets have already been received.
  Then, the response bodies can simply be concatenated to build the full response.
  }

  // in testing, there is no mirrored SERVERDATA_RESPONSE_VALUE!  The sent SERVERDATA_RESPONSE_VALUE
  // is responded with a single SERVERDATA_RESPONSE_VALUE that says 'Unknown request' in its payload!

  ReqID := SendRECONPacket(SERVERDATA_EXECCOMMAND, Cmd);
  TermReqID := SendRECONPacket(SERVERDATA_RESPONSE_VALUE, '');

  repeat
    RespID := ReadRECONPacket(PktType, Reply);
    if PktType <> SERVERDATA_RESPONSE_VALUE then
      raise Exception.Create('Received unexpected packet');

    if RespID <> ReqID then
    begin
      if RespID <> TermReqID then
        raise Exception.Create('Received unexpected packet');

      {
      RespID := ReadRECONPacket(PktType, Reply);
      if (PktType <> SERVERDATA_RESPONSE_VALUE) or (RespID <> TermReqID) then
        raise Exception.Create('Received unexpected packet');
      }

      Break;
    end;

    Result := Result + Reply;
  until False;
end;

function TForm1.ReadRECONPacket(var PktType: Integer; var Payload: String): Int32;
var
  Len: Int32;
begin
  try
    Len := IdTCPClient1.IOHandler.ReadInt32(False);
    Result := IdTCPClient1.IOHandler.ReadInt32(False);
    PktType := IdTCPClient1.IOHandler.ReadInt32(False);
    Payload := IdTCPClient1.IOHandler.ReadString(Len-10, IndyTextEncoding_ASCII);
    IdTCPClient1.IOHandler.Discard(2);
  except
    IdTCPClient1.Disconnect;
    raise;
  end;
end;