Obtaining client IP address from Windows Virtual Desktop app

[Dave Nottage 490]

I've found some code from an older repo (namely https://github.com/ccy/jedi-apilib) for what I want to achieve however I'm having trouble making it work. This is the code in question:

 

const
  WTS_CURRENT_SERVER_HANDLE = 0;
  WTS_CURRENT_SESSION = DWORD(-1);
  
type
  _WINSTATION_REMOTE_ADDRESS = record
    AddressFamily: DWORD;
    Port: WORD;
    Address: array [0..19] of Byte;
    Reserved: array[0..5] of Byte;
  end;
  PWINSTATION_REMOTE_ADDRESS = ^_WINSTATION_REMOTE_ADDRESS;
  TWinStationRemoteAddress = _WINSTATION_REMOTE_ADDRESS;
  PWinStationRemoteAddress = PWINSTATION_REMOTE_ADDRESS;

function WinStationQueryInformation(hServer: THandle; SessionId: DWORD; WinStationInformationClass: Cardinal; pWinStationInformation: PVOID;
  WinStationInformationLength: DWORD; var pReturnLength: DWORD): Boolean; stdcall;
  external 'winsta.dll' name 'WinStationQueryInformationW';
  
function GetWVDClientAddress: string;
var
  LBytesReturned: DWORD;
  LRemoteAddress: _WINSTATION_REMOTE_ADDRESS;
begin
  LBytesReturned := 0;
  ZeroMemory(@LClientAddress, SizeOf(LClientAddress));
  if WinStationQueryInformation(WTS_CURRENT_SERVER_HANDLE, WTS_CURRENT_SESSION, WinStationRemoteAddress, @LClientAddress, SizeOf(LClientAddress), LBytesReturned) then
  begin
    // Do something with LClientAddress here
  end
  else
    Result := SysErrorMessage(GetLastError);
end;

The call to WinStationQueryInformation is failing, and the message being returned by SysErrorMessage is: "The tag is invalid".

Is there something obvious that I'm missing?

[qubits 20]

nothing obvious..

wondering though looks like _WINSTATION_REMOTE_ADDRESS might have changed back in windows 8.1

Noticing that here maybe

This showed up in my search too. <-pascal anyways..

and here<- looks like you have to enumerate through all sessions, don't think you can pass -1

Edited February 7, 2022 by qubits
add content

[Dave Nottage 490]

On 2/8/2022 at 4:22 AM, qubits said:

looks like you have to enumerate through all sessions, don't think you can pass -1

That was it; thanks

[Dave Nottage 490]

On 2/10/2022 at 9:06 AM, Dave Nottage said:

That was it; thanks

Unfortunately, this gives the public facing IP address, which makes sense, however in my case isn't suitable.

 

What I am after is a way of obtaining a unique identifier for the "local" machine, by way of either one of the WTS functions or the Winstation functions.

[qubits 20]

Searching for Delphi Winsta.

I found this.

Looks old, but got allot in it.

[Dave Nottage 490]

8 minutes ago, qubits said:

I found this.

I'm aware of that one, but thanks 🙂 We've ended up going with a combination of:

WTSUserName
WTSDomainName
WTSClientName
WTSClientAddress

https://docs.microsoft.com/en-us/windows/win32/api/wtsapi32/ne-wtsapi32-wts_info_class

using WTSQuerySessionInformation