/*
    shutdown.c -  Logs the user off and optionally shutdown the system.

    Copyright (C) 1999-2002 Luis C. Castro Skertchly

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <windows.h>
#include <string.h>

OSVERSIONINFO info;
HANDLE hAccessToken;
TOKEN_PRIVILEGES tkp;
UINT uFlags;
LPVOID lpMsgBuf;


int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine,
                   int nCmdShow)
{
  if (!strcmp(lpCmdLine, "/?") || !strcmp(lpCmdLine, "-h") || !strcmp(lpCmdLine, "-H"))
  {
    MessageBox(NULL, "logoff [-f] [poweroff | reboot | shutdown]", "Usage", MB_OK);
    return 0;
  }
  info.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
  GetVersionEx(&info);
  if (info.dwPlatformId == VER_PLATFORM_WIN32_NT)
  {    
    if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hAccessToken))
    {
      MessageBox(NULL, "Cannot open Access Token", "Error", MB_ICONERROR | MB_APPLMODAL | MB_OK);
      return 0;
    }
    LookupPrivilegeValue(NULL, SE_SHUTDOWN_NAME, &tkp.Privileges[0].Luid);
    tkp.PrivilegeCount = 1;  // one privilege to set
    tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
    // Get the shutdown privilege for this process.
    AdjustTokenPrivileges(hAccessToken, FALSE, &tkp, 0, (PTOKEN_PRIVILEGES) NULL, 0);
    // Cannot test the return value of AdjustTokenPrivileges.
    if (GetLastError() != ERROR_SUCCESS)
    {
      MessageBox(NULL, "Cannot AdjustTokenPrivileges()", "Error", MB_ICONERROR | MB_APPLMODAL | MB_OK);
      return 0;
    }
  }
  uFlags = EWX_LOGOFF;
  if (strstr(lpCmdLine, "-f"))
    uFlags|= EWX_FORCE;

  if (strstr(lpCmdLine, "poweroff"))
    uFlags|= EWX_POWEROFF;

  if (strstr(lpCmdLine, "reboot"))
    uFlags|= EWX_REBOOT;

  if (strstr(lpCmdLine, "shutdown"))
    uFlags|= EWX_SHUTDOWN;

  if (!ExitWindowsEx(uFlags, 0))
  {
    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_MAX_WIDTH_MASK | FORMAT_MESSAGE_ARGUMENT_ARRAY,
          NULL,
          GetLastError(),
          0,
          (LPSTR) &lpMsgBuf,
          0,
          NULL);
    MessageBox(NULL, lpMsgBuf, "Error", MB_ICONERROR | MB_APPLMODAL | MB_OK);
    return GetLastError();
  }
  return 0;
}