source: branches/Delphi/URouterOS.pas

unit URouterOS;

interface

uses
  Classes, SysUtils, IdTelnet, Forms;

type
  TLineReceiveEvent = procedure(Line: string) of object;
  TConnectionState = (csNotConnected, csConnectedLoginProcessing, csConnectedPasswordProcessing,
    csConnectedReady, csConnectedCommandProcessing);
  TConnectionStateChangeEvent = procedure(State: TConnectionState) of object;
  TEscapeCodePhase = (ecNone, ecStart, ecBracket, ecEnd);

  TRouterOS = class
  private
    FirstResponseBracket: Boolean;
    Line: string;
    LineCharIndex: Integer;
    BufferParseState: TEscapeCodePhase;
    Telnet: TIdTelnet;
    UserName: string;
    Password: string;
    FOnLineReceive: TLineReceiveEvent;
    FConnectionState: TConnectionState;
    CommandResponse: TStringList;
    FOnConnectionStateChange: TConnectionStateChangeEvent;
    procedure ChangeState(NewState: TConnectionState);
    procedure HandleResponse(Line: string);
    procedure DataAvailable(Sender: TIdTelnet; const Buffer: String);
  public
    Timeout: Integer;
    function StripControlCodes(Text: string): string;
    function Execute(Command: string): TStringList;
    procedure Connect(HostName, UserName, Password: string);
    procedure Close;
    constructor Create;
    destructor Destroy; override;
    property OnLineReceive: TLineReceiveEvent read FOnLineReceive write FOnLineReceive;
    property OnConnectionStateChange: TConnectionStateChangeEvent read FOnConnectionStateChange write FOnConnectionStateChange;
    property ConnectionState: TConnectionState read FConnectionState;
  end;

implementation

{ TRouterOS }

procedure TRouterOS.ChangeState(NewState: TConnectionState);
begin
  if NewState <> FConnectionState then 
    if Assigned(FOnConnectionStateChange) then
      FOnConnectionStateChange(NewState);
  FConnectionState := NewState;
end;

procedure TRouterOS.Close;
begin

end;

procedure TRouterOS.Connect(HostName, UserName, Password: string);
begin
  with Telnet do begin
    FirstResponseBracket := True;
    OnDataAvailable := DataAvailable;
    Self.UserName := UserName;
    Self.Password := Password;
    Connect(HostName);
    if not Connected then raise Exception.Create('Could not connect to ' + HostName)
      else FConnectionState := csConnectedLoginProcessing;
  end;
end;

constructor TRouterOS.Create;
begin
  Timeout := 3000;
  Telnet := TIdTelnet.Create(nil);
  CommandResponse := TStringList.Create;
  Line := '';
  LineCharIndex := 1;
end;

procedure TRouterOS.DataAvailable(Sender: TIdTelnet; const Buffer: String);
var
  I: Integer;
  Temp: string;
begin
  I := 1;
  repeat
    while I <= Length(Buffer) do begin
      if Buffer[I] = #13 then LineCharIndex := 1  // Carriage return
      else if Buffer[I] = #10 then begin // Line feed
        HandleResponse(Line);
        Line := '';
        LineCharIndex := 1;
      end else if Buffer[I] = #27 then begin // Escape
        BufferParseState := ecStart;
      end else if Ord(Buffer[I]) < 32 then begin
      end else begin
        if (BufferParseState = ecStart) then begin
          if (Buffer[I] = '[') then begin
            BufferParseState := ecBracket;
          end else BufferParseState := ecNone;
        end else
        if (BufferParseState = ecBracket) then begin
          if (Buffer[I] >= '0') and (Buffer[I] <= '9') then begin
          end else BufferParseState := ecNone;
        end else begin
          if Length(Line) < LineCharIndex then SetLength(Line, LineCharIndex);
          Line[LineCharIndex] := Buffer[I];
          Inc(LineCharIndex);
        end;
      end;
      Inc(I);
    end;
  until I >= Length(Buffer);

  Temp := Trim(Line);
  if Line <> '' then
  case FConnectionState of
    csConnectedLoginProcessing: begin
      if Line = 'Login: ' then begin
        Telnet.IOHandler.WriteLn(UserName);
        ChangeState(csConnectedPasswordProcessing);
      end;
    end;
    csConnectedPasswordProcessing: begin
      if Line = 'Password: ' then begin
        Telnet.IOHandler.WriteLn(Password);
      end;
      if Line[1] = '[' then ChangeState(csConnectedReady)
    end;
    csConnectedCommandProcessing: begin
      if Line[1] = '[' then begin
        //if not FirstResponseBracket then FirstResponseBracket := True
        //else ChangeState(csConnectedReady)
        if (Line[1] = '[') and (Temp[Length(Temp)] = '>') then
          ChangeState(csConnectedReady);
      end else CommandResponse.Add(Line);
    end;
  end;
end;

destructor TRouterOS.Destroy;
begin
  CommandResponse.Free;
  Telnet.Free;
  inherited;
end;

function TRouterOS.Execute(Command: string): TStringList;
var
  Time: Integer;
begin
  FirstResponseBracket := False;
  CommandResponse.Clear;
  ChangeState(csConnectedCommandProcessing);
  Result := TStringList.Create;
  Telnet.IOHandler.WriteLn(#27'[7l' + Command);
  Time := 0;
  while (FConnectionState = csConnectedCommandProcessing) and (Time < Timeout) do begin
    Sleep(10);
    Application.ProcessMessages;
    Inc(Time, 10);
  end;
  if Time >= Timeout then
    raise Exception.Create('Connection timeout');
  
  Result.Assign(CommandResponse);
end;

procedure TRouterOS.HandleResponse(Line: string);
begin
  if Assigned(FOnLineReceive) then FOnLineReceive(Line);
  if Line <> '' then
  case FConnectionState of
    csConnectedReady: begin
    end;
    csConnectedCommandProcessing: begin
      if Line[1] = '[' then begin
        if not FirstResponseBracket then FirstResponseBracket := True
        else ChangeState(csConnectedReady)
      end else CommandResponse.Add(Line);
    end;
  end;
end;

function TRouterOS.StripControlCodes(Text: string): string;
var
  EscapeCode: TEscapeCodePhase;
  I: Integer;
begin
  Result := '';
  EscapeCode := ecNone;
  I := 1;
  while I <= Length(Text) do begin
    if Ord(Text[I]) < 32 then begin
      Result := Result + '#' + IntToStr(Ord(Text[I]));
      //if Ord(Text[I]) = 27 then begin
      //  EscapeCode := ecStart;
      //end;
    end else begin
      if Escapecode = ecStart then begin
        if Text[I] = '[' then EscapeCode := ecBracket
        else Result := Result + Text[I];
      end else Result := Result + Text[I];
    end;
    Inc(I);
  end;
end;

end.