idtelnet.pas

indy的原文件哈!大家可以下来参考和学习之用.也可以用以作组件.开发其他的应用程序.

  ThreadedEvent := False;
end;

destructor TIdTelnet.Destroy;
begin
  Disconnect;
  inherited Destroy;
end;

procedure TIdTelnet.Disconnect;
begin
  if Assigned(FTelnetThread) then begin
    FTelnetThread.Terminate;
  end;
  IAmTelnet := False;
  inherited Disconnect;
  if Assigned(FOnDisconnect) then begin
    OnDisconnect(SELF);
  end;
  if Assigned(FTelnetThread) then begin
    FTelnetThread.WaitFor;
  end;
  FreeAndNIL(FTelnetThread);
End;//Disconnect

procedure TIdTelnet.DoOnDataAvailable(const Buf: String);
begin
  if Assigned(FOnDataAvailable) then begin
    OnDataAvailable(SELF, Buf);
  end else begin
    raise EIdTelnetServerOnDataAvailableIsNil.Create(RSTELNETSRVOnDataAvailableIsNil);
  end;
end;

procedure TIdTelnet.Connect(const ATimeout: Integer = IdTimeoutDefault);
begin
  inherited Connect(ATimeout);
  try
    if Assigned(FOnConnect) then begin
      OnConnect(SELF);
    end;
    // create the reading thread and assign the current Telnet object to it
    FTelnetThread := TIdTelnetReadThread.Create(SELF);
  except
    Disconnect;
    raise EIdTelnetClientConnectError.Create(RSTELNETCLIConnectError);  // translate
  end;
end;

procedure TIdTelnet.SendNegotiationResp(var Resp: String);
begin
  Write(Resp);
  Resp := '';    {Do not Localize}
end;

procedure TIdTelnet.Handle_SB(CurrentSB: Byte; sbData: String; sbCount: Integer);
var
  Resp : String;
begin
  if (sbcount > 0) and (sbdata = TNOS_TERMTYPE_SEND) then
  begin
    // if someone inadvertantly sets Termnal to null
    // You can set termial to anything you want i supose but be prepared to handle
    // the data emulation yourself
    if Terminal = '' then    {Do not Localize}
      Terminal := 'dumb';    {Do not Localize}
    Resp := TNC_IAC + TNC_SB + TNO_TERMTYPE + TNOS_TERM_IS + Terminal + TNC_IAC + TNC_SE;
    SendNegotiationResp(Resp);
  end;
  // add authentication code here
end;

procedure TIdTelnet.Negotiate(const Buf: String);
var
  LCount: Integer;
  bOffset   : Integer;
  nOffset   : Integer;
  B         : Char;
  nBuf      : String;
  sbBuf     : String;
  sbCount   : Integer;
  CurrentSb : Integer;
  SendBuf   : String;
begin
  bOffset := 1;
  nOffset := 0;
  sbCount := 1;
  CurrentSB := 1;
  nbuf := '';    {Do not Localize}
  LCount := Length(Buf);
  while bOffset <= LCount do
  begin
    b := Buf[bOffset];
    case State of
      tnsData: { start of command sequence }
        if b = TNC_IAC then
        begin
          IamTelnet := True;
          State := tnsIAC;
        end
        else
          nbuf := nbuf + b;

      tnsIAC: { a Do request }
        case b of
          TNC_IAC:
            begin
              State := tnsData;
              inc(nOffset);
              nbuf[nOffset] := TNC_IAC;
            end;
          TNC_WILL:
            State := tnsIAC_WILL;
          TNC_WONT:
            State := tnsIAC_WONT;
          TNC_DONT:
            State := tnsIAC_DONT;
          TNC_DO:
            State := tnsIAC_DO;
          TNC_EOR:
            State := tnsDATA;
          TNC_SB:
            begin
              State := tnsIAC_SB;
              sbCount := 0;
            end;
        else
          State := tnsData; // the default setting
        end; //end case b

      tnsIAC_WILL:
        begin
          case b of
            TNO_ECHO:
              begin
                Reply := TNC_DO;
                DoTelnetCommand(tncNoLocalEcho);
//                doStatus('NOLOCALECHO');    {Do not Localize}
              end;
            TNO_EOR:
              Reply := TNC_DO;
          else
            Reply := TNC_DONT;
          end; // end case b

        //  if (Reply <> SentDoDont) or (TNC_WILL <> ReceivedWillWont) then
          begin
            SendBuf := TNC_IAC + Reply + b;
            SendNegotiationResp(SendBuf);
            SentDoDont := Reply;
            ReceivedWillWont := TNC_WILL;
          end;
          State := tnsData;
        end; // end of tnsIAC_WILL

      tnsIAC_WONT:
        begin
          case b of
            TNO_ECHO:
              begin
                DoTelnetCommand(tncLocalEcho);
//                Dostatus('LOCALECHO');    {Do not Localize}
                Reply := TNC_DONT;
              end;
            TNO_EOR:
              Reply := TNC_DONT;
          else
            Reply := TNC_DONT;
          end; // end case b

        //  if (Reply <> SentDoDont) or (ReceivedWillWont <> TNC_WONT) then
          begin
            SendBuf := TNC_IAC + Reply + b;
            SendNegotiationResp(SendBuf);
            SentDoDont := Reply;
            ReceivedWillWont := TNC_WILL;
          end;
          State := tnsData;

        end; // end tnsIAC_WONT
      tnsIAC_DO:
      begin
        case b of
          TNO_ECHO:
            begin
              DoTelnetCommand(tncLocalEcho);
              Reply := TNC_WILL;
            end;
          TNO_TERMTYPE:
            Reply := TNC_WILL;
          //TNO_NAWS:
          TNO_AUTH:
          begin
//            if(Authentication) then
//            Reply := TNC_WILL
//            else
            Reply := TNC_WONT;
          end;
        else
          Reply := TNC_WONT;
        end; // end of case b
        //if (Reply <> SentWillWont) or (ReceivedDoDont <> TNC_DO) then
        begin
          SendBuf := TNC_IAC + Reply + b;
          SendNegotiationResp(SendBuf);
          SentWillWont := Reply;
          ReceivedDoDont := TNC_DO;
        end;
        State := tnsData;
      end;
      tnsIAC_DONT:
      begin
        case b of
          TNO_ECHO:
            begin
              DoTelnetCommand(tncEcho);
//              DoStatus('ECHO');    {Do not Localize}
              Reply := TNC_WONT;
            end;
          TNO_NAWS:
            Reply := TNC_WONT;
          TNO_AUTH:
            Reply := TNC_WONT
        else
          Reply := TNC_WONT;
        end; // end case b

      //  if (Reply <> SentWillwont) or (TNC_DONT <> ReceivedDoDont) then
        begin
          SendBuf := TNC_IAC + reply + b;
          SendNegotiationResp(SendBuf);
        end;
        State := tnsData;
      end;

      tnsIAC_SB:
        begin
          if b = TNC_IAC then
            State := tnsIAC_SBIAC
          else begin
            CurrentSb := Ord(b);
            sbCount := 0;
            State := tnsIAC_SBDATA;
          end;
        end;
      tnsIAC_SBDATA:
        begin
          if b = TNC_IAC then
            State := tnsSBDATA_IAC
          else begin
            inc(sbCount);
            sbBuf := b;
          end;
        end;
      tnsSBDATA_IAC:
        case b of
          TNC_IAC:
            begin
              State := tnsIAC_SBDATA;
              inc(sbCount);
              sbBuf[sbCount] := TNC_IAC;
            end;
          TNC_SE:
            begin
              handle_sb(CurrentSB,sbBuf,sbCount);
              CurrentSB	:= 0;
              State := tnsData;
            end;
          TNC_SB:
            begin
              handle_sb(CurrentSB,sbBuf,sbCount);
              CurrentSB	:= 0;
              State := tnsIAC_SB;
            end
         else
           State := tnsDATA;
         end;
      else
        State := tnsData;
    end; // end case State
    inc(boffset);
  end; // end while
  // if textual data is returned by the server then send this data to
  // the client app
  if Length(nBuf) > 0 then begin
    DoOnDataAvailable(nBuf);
  end;
end;

procedure TIdTelnet.DoTelnetCommand(Status: TIdTelnetCommand);
begin
  if Assigned(FOnTelnetCommand) then
    FOnTelnetCommand(Self, Status);
end;

END.