{
  $Project$
  $Workfile$
  $Revision$
  $DateUTC$
  $Id$

  This file is part of the Indy (Internet Direct) project, and is offered
  under the dual-licensing agreement described on the Indy website.
  (http://www.indyproject.org/)

  Copyright:
   (c) 1993-2005, Chad Z. Hower and the Indy Pit Crew. All rights reserved.
}
{
  $Log$
}
{
  Rev 1.10    11/12/2004 11:30:16 AM  JPMugaas
  Expansions for IPv6.

  Rev 1.9    11/11/2004 10:25:22 PM  JPMugaas
  Added OpenProxy and CloseProxy so you can do RecvFrom and SendTo functions
  from the UDP client with SOCKS.  You must call OpenProxy  before using
  RecvFrom or SendTo.  When you are finished, you must use CloseProxy to close
  any connection to the Proxy.  Connect and disconnect also call OpenProxy and
  CloseProxy.

  Rev 1.8    11/11/2004 3:42:52 AM  JPMugaas
  Moved strings into RS.  Socks will now raise an exception if you attempt to
  use SOCKS4 and SOCKS4A with UDP.  Those protocol versions do not support UDP
  at all.

  Rev 1.7    11/9/2004 8:18:00 PM  JPMugaas
  Attempt to add SOCKS support in UDP.

  Rev 1.6    6/6/2004 11:51:56 AM  JPMugaas
  Fixed TODO with an exception

  Rev 1.5    2004.02.03 4:17:04 PM  czhower
  For unit name changes.

    Rev 1.4    10/15/2003 10:59:06 PM  DSiders
  Corrected spelling error in resource string name.
  Added resource string for circular links exception in transparent proxy.

    Rev 1.3    10/15/2003 10:10:18 PM  DSiders
  Added localization comments.

    Rev 1.2    5/16/2003 9:22:38 AM  BGooijen
  Added Listen(...)

    Rev 1.1    5/14/2003 6:41:00 PM  BGooijen
  Added Bind(...)

  Rev 1.0    12/2/2002 05:01:26 PM  JPMugaas
  Rechecked in due to file corruption.
}

unit IdCustomTransparentProxy;

interface

uses
  IdComponent,
  IdException,
  IdGlobal,
  IdObjs,
  IdIOHandler,
  IdSocketHandle,
  IdSys, IdBaseComponent;

type
  EIdTransparentProxyCircularLink = class(EIdException);
  EIdTransparentProxyUDPNotSupported = class(EIdException);
  TIdCustomTransparentProxyClass = class of TIdCustomTransparentProxy;

  TIdCustomTransparentProxy = class(TIdComponent)
  protected
    FHost: String;
    FPassword: String;
    FPort: Integer;
    FIPVersion : TIdIPVersion;
    FUsername: String;
    FChainedProxy: TIdCustomTransparentProxy;
    //
    function  GetEnabled: Boolean; virtual; abstract;
    procedure SetEnabled(AValue: Boolean); virtual;
    procedure MakeConnection(AIOHandler: TIdIOHandler; const AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION); virtual; abstract;
    procedure Notification(AComponent: TIdNativeComponent; Operation: TIdOperation); override;
    procedure SetChainedProxy(const AValue: TIdCustomTransparentProxy);
  public
    procedure Assign(ASource: TIdPersistent); override;
    procedure OpenUDP(AHandle : TIdSocketHandle; const AHost: string=''; const APort: Integer=0; const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION); virtual;
    procedure CloseUDP(AHandle: TIdSocketHandle); virtual;
    function RecvFromUDP(AHandle: TIdSocketHandle;
      var ABuffer : TIdBytes;
      var VPeerIP: string; var VPeerPort: integer; const AIPVersion: TIdIPVersion;
       AMSec: Integer = IdTimeoutDefault): integer; virtual;
    procedure SendToUDP(AHandle: TIdSocketHandle;
      AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion; const ABuffer : TIdBytes); virtual;
    procedure Connect(AIOHandler: TIdIOHandler; const AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION);
    //
    procedure Bind(AIOHandler: TIdIOHandler; const AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION);overload;virtual;
    procedure Bind(AIOHandler: TIdIOHandler; const APort: Integer);overload;
    function  Listen(AIOHandler: TIdIOHandler; const ATimeOut:integer):boolean;virtual;
    //
    property  Enabled: Boolean read GetEnabled write SetEnabled;
    property  Host: String read FHost write FHost;
    property  Password: String read FPassword write FPassword;
    property  Port: Integer read FPort write FPort;
    property  IPVersion : TIdIPVersion read FIPVersion write FIPVersion default ID_DEFAULT_IP_VERSION;
    property  Username: String read FUsername write FUsername;
    property  ChainedProxy: TIdCustomTransparentProxy read FChainedProxy write SetChainedProxy;
  End;//TIdCustomTransparentProxy

implementation

uses
  IdResourceStringsCore, IdExceptionCore;

{ TIdCustomTransparentProxy }

procedure TIdCustomTransparentProxy.Assign(ASource: TIdPersistent);
Begin
  if ASource is TIdCustomTransparentProxy then begin
    with TIdCustomTransparentProxy(ASource) do begin
      Self.FHost := Host;
      Self.FPassword := Password;
      Self.FPort := Port;
      Self.FIPVersion := IPVersion;
      Self.FUsername := Username;
    end
  end else begin
    inherited Assign(ASource);
  end;
End;//

procedure TIdCustomTransparentProxy.Connect(AIOHandler: TIdIOHandler; const AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION);
begin
  if Assigned(FChainedProxy) and FChainedProxy.Enabled then begin
    MakeConnection(AIOHandler, FChainedProxy.Host, FChainedProxy.Port);
    FChainedProxy.Connect(AIOHandler, AHost, APort,AIPVersion);
  end else begin
    MakeConnection(AIOHandler, AHost, APort, AIPVersion);
  end;
end;

function TIdCustomTransparentProxy.Listen(AIOHandler: TIdIOHandler; const ATimeOut: integer):boolean;
begin
  raise EIdTransparentProxyCantBind.Create(RSTransparentProxyCannotBind);
end;

procedure TIdCustomTransparentProxy.Bind(AIOHandler: TIdIOHandler; const AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION);
begin
  raise EIdTransparentProxyCantBind.Create(RSTransparentProxyCannotBind);
end;

procedure TIdCustomTransparentProxy.Bind(AIOHandler: TIdIOHandler; const APort: Integer);
begin

  Bind(AIOHandler, '0.0.0.0', APort);   {do not localize}
end;

procedure TIdCustomTransparentProxy.SetEnabled(AValue: Boolean);
Begin
End;

procedure TIdCustomTransparentProxy.Notification(AComponent: TIdNativeComponent; Operation: TIdOperation);
begin
  if (Operation = opRemove) and (AComponent = FChainedProxy) then begin
    FChainedProxy := nil;
  end;
  inherited Notification(AComponent,Operation);
end;

procedure TIdCustomTransparentProxy.SetChainedProxy(const AValue: TIdCustomTransparentProxy);
var
  LNextValue: TIdCustomTransparentProxy;
begin
  LNextValue := AValue;
  while Assigned(LNextValue) do begin
    if LNextValue = SELF then begin
      raise EIdTransparentProxyCircularLink.Create(Sys.Format(RSInterceptCircularLink,[ClassName]));// -> One EIDCircularLink exception
    end;
    LNextValue := LNextValue.FChainedProxy;
  end;

  FChainedProxy := AValue;

  if Assigned(AValue) then begin
    AValue.FreeNotification(Self);
  end;
end;

procedure TIdCustomTransparentProxy.CloseUDP(AHandle: TIdSocketHandle);
begin
  raise EIdTransparentProxyUDPNotSupported.Create(RSTransparentProxyCanNotSupportUDP);
end;

procedure TIdCustomTransparentProxy.OpenUDP(AHandle: TIdSocketHandle;
  const AHost: string=''; const APort: Integer=0;const AIPVersion: TIdIPVersion = ID_DEFAULT_IP_VERSION);
begin
  raise EIdTransparentProxyUDPNotSupported.Create( RSTransparentProxyCanNotSupportUDP );
end;

function TIdCustomTransparentProxy.RecvFromUDP(AHandle: TIdSocketHandle;
      var ABuffer : TIdBytes;
      var VPeerIP: string; var VPeerPort: integer; const AIPVersion: TIdIPVersion;
       AMSec: Integer = IdTimeoutDefault): integer;
begin
   raise EIdTransparentProxyUDPNotSupported.Create(RSTransparentProxyCanNotSupportUDP);
end;

procedure TIdCustomTransparentProxy.SendToUDP(AHandle: TIdSocketHandle;
      AHost: string; const APort: Integer; const AIPVersion: TIdIPVersion; const ABuffer : TIdBytes);
begin
   raise EIdTransparentProxyUDPNotSupported.Create(RSTransparentProxyCanNotSupportUDP);
end;

end.

