Detect source of remote desktop connection

Question

This question tells me how to detect a remote desktop session.

Do anybody know if it's possible to find out from where the remote connection was initialized?

Answer 1

@Vegar, you can use the WTSEnumerateSessions and WTSQuerySessionInformation functions to retrieve this info.

check this link for an example using the Jedi Api Headers.

check this code.

program ProjectTsInfo;

{$APPTYPE CONSOLE}

Uses
  Windows,
  JwaWinType,
  JwaWtsApi32,
  JwaWinsock2,
  SysUtils,
  TypInfo;


type
  PWtsSessionInfoAArray = ^TWtsSessionInfoAArray;
  TWtsSessionInfoAArray = array[0..ANYSIZE_ARRAY-1] of WTS_SESSION_INFOA;

//Get the info for all clients connected
procedure GetAll_TSClientsInfo;
var
  SessionInfoAArray: PWtsSessionInfoAArray;
  ClientAddr       : PWtsClientAddress;
  ClientName       : PAnsiChar;
  //ClientInfo       : PWTSCLIENT;
  RetBytes         : Cardinal;
  IPAddr           : String;
  i                : integer;
  pCount           : Cardinal;
  SessionId        : Cardinal;
begin

  if WtsEnumerateSessions(WTS_CURRENT_SERVER, 0, 1, PWTS_SESSION_INFO(SessionInfoAArray),  pCount) then
  begin

    for i := 0 to pCount - 1 do
    begin
      SessionId:=SessionInfoAArray^[i].SessionId;
      WTSQuerySessionInformation(WTS_CURRENT_SERVER, SessionId, WTSClientAddress, Pointer(ClientAddr), RetBytes);
      WTSQuerySessionInformation(WTS_CURRENT_SERVER, SessionId, WTSClientName, Pointer(ClientName), RetBytes);
      //WTSQuerySessionInformation(WTS_CURRENT_SERVER, SessionId, WTSClientInfo, Pointer(ClientInfo), RetBytes);  //This value is supported for Windows Server 2008 and Windows Vista with SP1.

     try
      case ClientAddr^.AddressFamily of
        AF_INET:
          IPAddr:= Format('%d.%d.%d.%d', [
            ClientAddr^.Address[2],
            ClientAddr^.Address[3],
            ClientAddr^.Address[4],
            ClientAddr^.Address[5]
            ]);
        else
        IPAddr:= '<unknow>';
      end;

      WriteLn(Format('Session Id  : %d ', [SessionId]));
      WriteLn(Format('Client Name : %s ', [ClientName]));
      WriteLn(Format('Station Name: %s ', [SessionInfoAArray^[i].pWinStationName]));
      WriteLn(Format('State       : %s ', [GetEnumName(TypeInfo(WTS_CONNECTSTATE_CLASS),integer(SessionInfoAArray^[i].State))]));
      WriteLn(Format('IP          : %s ', [IPAddr]));

      //supported for Windows Server 2008 and Windows Vista with SP1.
      {
      WriteLn(Format('ClientName      : %s ', [ClientInfo^.ClientName]));
      WriteLn(Format('Domain          : %s ', [ClientInfo^.Domain]));
      WriteLn(Format('UserName        : %s ', [ClientInfo^.UserName]));
      WriteLn(Format('WorkDirectory   : %s ', [ClientInfo^.WorkDirectory]));
      WriteLn(Format('InitialProgram  : %s ', [ClientInfo^.InitialProgram]));
      WriteLn(Format('EncryptionLevel : %d ', [ClientInfo^.EncryptionLevel]));
      WriteLn(Format('HRes            : %d ', [ClientInfo^.HRes]));
      WriteLn(Format('VRes            : %d ', [ClientInfo^.VRes]));
      WriteLn(Format('ColorDepth      : %d ', [ClientInfo^.ColorDepth]));
      WriteLn(Format('ClientDirectory : %s ', [ClientInfo^.ClientDirectory]));
      }
      Writeln('');

   finally
      WTSFreeMemory(ClientAddr);
      WTSFreeMemory(ClientName);
   end;
    end;
  end;

  WtsFreeMemory(SessionInfoAArray);
end;

//Get the ip address of the actual connected client
function GetIpActualClient : string;
var
  ClientAddr       : PWtsClientAddress;
  RetBytes         : Cardinal;
  IPAddr           : String;
  SessionId        : Cardinal;
begin
      SessionId:=WTS_CURRENT_SESSION;
      WTSQuerySessionInformation(WTS_CURRENT_SERVER, SessionId, WTSClientAddress, Pointer(ClientAddr), RetBytes);
      try
        case ClientAddr^.AddressFamily of
          AF_INET:
            IPAddr:= Format('%d.%d.%d.%d', [
              ClientAddr^.Address[2],
              ClientAddr^.Address[3],
              ClientAddr^.Address[4],
              ClientAddr^.Address[5]
              ]);
          else
          IPAddr:= '<unknow>';
        end;
      Result:=IPAddr;
      finally
       WTSFreeMemory(ClientAddr);
      end;
end;

begin
  Writeln('IP Actual client '+GetIpActualClient);
  Writeln('-----------------------------------');

  GetAll_TSClientsInfo;
  Readln;
end.

UPDATE

As @Remko says, the WTSQuerySessionInformation function with the WTSClientAddress type, can return the local IP of the client. if you wanna get the real ip you can use the WinStationGetRemoteIPAddress helper function located in the JwaWinSta unit.

Var
Port    : Word;
IpAddr  : WideString;
Begin
WinStationGetRemoteIPAddress(WTS_CURRENT_SERVER,WTS_CURRENT_SESSION,IpAddr,Port);
End;

Answer 2

For me, this worked, it gets the name of the machine connected.

Environment.GetEnvironmentVariable("CLIENTNAME")