/* * OpenVPN-GUI -- A Windows GUI for OpenVPN. * * Copyright (C) 2004 Mathias Sundman * * 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 (see the file COPYING included with this * distribution); if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef HAVE_CONFIG_H #include #endif #if !defined (UNICODE) #error UNICODE and _UNICODE must be defined. This version only supports unicode builds. #endif #include #include #include #include #include #include #include "tray.h" #include "openvpn.h" #include "openvpn_config.h" #include "viewlog.h" #include "service.h" #include "main.h" #include "options.h" #include "passphrase.h" #include "proxy.h" #include "registry.h" #include "openvpn-gui-res.h" #include "localization.h" #include "manage.h" #include "misc.h" #include "save_pass.h" #ifndef DISABLE_CHANGE_PASSWORD #include #include #endif #define OVPN_EXITCODE_ERROR 1 #define OVPN_EXITCODE_TIMEOUT 2 #define OVPN_EXITCODE_NOTREADY 3 /* Declare Windows procedure */ LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM); static void ShowSettingsDialog(); void CloseApplication(HWND hwnd); void ImportConfigFile(); /* Class name and window title */ TCHAR szClassName[ ] = _T("OpenVPN-GUI"); TCHAR szTitleText[ ] = _T("OpenVPN"); /* Options structure */ options_t o; /* Workaround for ASLR on Windows */ __declspec(dllexport) char aslr_workaround; static int VerifyAutoConnections() { int i; for (i = 0; i < MAX_CONFIGS && o.auto_connect[i] != 0; i++) { if (GetConnByName(o.auto_connect[i]) == NULL) { /* autostart config not found */ ShowLocalizedMsg(IDS_ERR_AUTOSTART_CONF, o.auto_connect[i]); return FALSE; } } return TRUE; } /* * Send a copydata message corresponding to any --command action option specified * to the running instance and return success or error. */ static int NotifyRunningInstance() { /* Check if a previous instance has a window initialized * Even if we are not the first instance this may return null * if the previous instance has not fully started up */ HANDLE hwnd_master = FindWindow (szClassName, NULL); int exit_code = 0; if (hwnd_master) { /* GUI up and running -- send a message if any action is pecified, else show the balloon */ COPYDATASTRUCT config_data = {0}; int timeout = 30*1000; /* 30 seconds */ if (!o.action) { o.action = WM_OVPN_NOTIFY; o.action_arg = LoadLocalizedString(IDS_NFO_CLICK_HERE_TO_START); } config_data.dwData = o.action; if (o.action_arg) { config_data.cbData = (wcslen(o.action_arg)+1)*sizeof(o.action_arg[0]); config_data.lpData = (void *) o.action_arg; } PrintDebug(L"Instance 2: called with action %d : %s", o.action, o.action_arg); if (!SendMessageTimeout (hwnd_master, WM_COPYDATA, 0, (LPARAM) &config_data, 0, timeout, NULL)) exit_code = OVPN_EXITCODE_TIMEOUT; } else { PrintDebug(L"Instance 2: Previous instance not yet ready to accept comamnds"); exit_code = OVPN_EXITCODE_NOTREADY; } PrintDebug(L"Instance 2: Returning exit code %d", exit_code); return exit_code; } int WINAPI _tWinMain (HINSTANCE hThisInstance, UNUSED HINSTANCE hPrevInstance, UNUSED LPTSTR lpszArgument, UNUSED int nCmdShow) { MSG messages; /* Here messages to the application are saved */ WNDCLASSEX wincl; /* Data structure for the windowclass */ DWORD shell32_version; BOOL first_instance = TRUE; /* a session local semaphore to detect second instance */ HANDLE session_semaphore = InitSemaphore(L"Local\\"PACKAGE_NAME); /* try to lock the semaphore, else we are not the first instance */ if (session_semaphore && WaitForSingleObject(session_semaphore, 0) != WAIT_OBJECT_0) { first_instance = FALSE; } /* Initialize handlers for manangement interface notifications */ mgmt_rtmsg_handler handler[] = { { ready, OnReady }, { hold, OnHold }, { log, OnLogLine }, { state, OnStateChange }, { password, OnPassword }, { proxy, OnProxy }, { stop, OnStop }, { needok, OnNeedOk }, { needstr, OnNeedStr }, { echo, OnEcho }, { bytecount,OnByteCount }, { 0, NULL } }; InitManagement(handler); /* initialize options to default state */ InitOptions(&o); #ifdef DEBUG /* Open debug file for output */ if (!(o.debug_fp = _wfopen(DEBUG_FILE, L"a+,ccs=UTF-8"))) { /* can't open debug file */ ShowLocalizedMsg(IDS_ERR_OPEN_DEBUG_FILE, DEBUG_FILE); exit(1); } PrintDebug(_T("Starting OpenVPN GUI v%S"), PACKAGE_VERSION); #endif o.hInstance = hThisInstance; if(!GetModuleHandle(_T("RICHED20.DLL"))) { LoadLibrary(_T("RICHED20.DLL")); } else { /* can't load riched20.dll */ ShowLocalizedMsg(IDS_ERR_LOAD_RICHED20); exit(1); } /* Check version of shell32.dll */ shell32_version=GetDllVersion(_T("shell32.dll")); if (shell32_version < PACKVERSION(5,0)) { /* shell32.dll version to low */ ShowLocalizedMsg(IDS_ERR_SHELL_DLL_VERSION, shell32_version); exit(1); } #ifdef DEBUG PrintDebug(_T("Shell32.dll version: 0x%lx"), shell32_version); #endif if (first_instance) UpdateRegistry(); /* Checks version change and update keys/values */ GetRegistryKeys(); /* Parse command-line options */ ProcessCommandLine(&o, GetCommandLine()); EnsureDirExists(o.config_dir); if (!first_instance) { int res = NotifyRunningInstance(); exit(res); } else if (o.action == WM_OVPN_START) { PrintDebug(L"Instance 1: Called with --command connect xxx. Treating it as --connect xxx"); } else if (o.action) { PrintDebug(L"Instance 1: Called with --command when no previous instance available"); exit(OVPN_EXITCODE_ERROR); } if (!CheckVersion()) { exit(1); } if (!EnsureDirExists(o.log_dir)) { ShowLocalizedMsg(IDS_ERR_CREATE_PATH, _T("log_dir"), o.log_dir); exit(1); } if (!IsUserAdmin() && strtod(o.ovpn_version, NULL) > 2.3 && !o.silent_connection) CheckIServiceStatus(TRUE); BuildFileList(); if (!VerifyAutoConnections()) { exit(1); } GetProxyRegistrySettings(); #ifndef DISABLE_CHANGE_PASSWORD /* Initialize OpenSSL */ OpenSSL_add_all_algorithms(); ERR_load_crypto_strings(); #endif /* The Window structure */ wincl.hInstance = hThisInstance; wincl.lpszClassName = szClassName; wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */ wincl.style = CS_DBLCLKS; /* Catch double-clicks */ wincl.cbSize = sizeof (WNDCLASSEX); /* Use default icon and mouse-pointer */ wincl.hIcon = LoadLocalizedIcon(ID_ICO_APP); wincl.hIconSm = LoadLocalizedIcon(ID_ICO_APP); wincl.hCursor = LoadCursor (NULL, IDC_ARROW); wincl.lpszMenuName = NULL; /* No menu */ wincl.cbClsExtra = 0; /* No extra bytes after the window class */ wincl.cbWndExtra = 0; /* structure or the window instance */ /* Use Windows's default color as the background of the window */ wincl.hbrBackground = (HBRUSH) COLOR_3DSHADOW; //COLOR_BACKGROUND; /* Register the window class, and if it fails quit the program */ if (!RegisterClassEx (&wincl)) return 1; /* The class is registered, let's create the program*/ CreateWindowEx ( 0, /* Extended possibilites for variation */ szClassName, /* Classname */ szTitleText, /* Title Text */ WS_OVERLAPPEDWINDOW, /* default window */ (int)CW_USEDEFAULT, /* Windows decides the position */ (int)CW_USEDEFAULT, /* where the window ends up on the screen */ 230, /* The programs width */ 200, /* and height in pixels */ HWND_DESKTOP, /* The window is a child-window to desktop */ NULL, /* No menu */ hThisInstance, /* Program Instance handler */ NULL /* No Window Creation data */ ); /* Run the message loop. It will run until GetMessage() returns 0 */ while (GetMessage (&messages, NULL, 0, 0)) { TranslateMessage(&messages); DispatchMessage(&messages); } /* The program return-value is 0 - The value that PostQuitMessage() gave */ return messages.wParam; } static void StopAllOpenVPN() { int i; for (i = 0; i < o.num_configs; i++) { if (o.conn[i].state != disconnected) StopOpenVPN(&o.conn[i]); } /* Wait for all connections to terminate (Max 5 sec) */ for (i = 0; i < 20; i++, Sleep(250)) { if (CountConnState(disconnected) == o.num_configs) break; } } static int AutoStartConnections() { int i; for (i = 0; i < o.num_configs; i++) { if (o.conn[i].auto_connect) StartOpenVPN(&o.conn[i]); } return TRUE; } static void ResumeConnections() { int i; for (i = 0; i < o.num_configs; i++) { /* Restart suspend connections */ if (o.conn[i].state == suspended) StartOpenVPN(&o.conn[i]); /* If some connection never reached SUSPENDED state */ if (o.conn[i].state == suspending) StopOpenVPN(&o.conn[i]); } } /* * Set scale factor of windows in pixels. Scale = 100% for dpi = 96 */ static void dpi_setscale(UINT dpix) { /* scale factor in percentage compared to the reference dpi of 96 */ if (dpix != 0) o.dpi_scale = MulDiv(dpix, 100, 96); else o.dpi_scale = 100; PrintDebug(L"DPI scale set to %u", o.dpi_scale); } /* * Get dpi of the system and set the scale factor. * The system dpi may be different from the per monitor dpi on * Win 8.1 later. We set dpi awareness to system-dpi level in the * manifest, and let Windows automatically re-scale windows * if/when dpi changes dynamically. */ static void dpi_initialize(void) { UINT dpix = 0; HDC hdc = GetDC(NULL); if (hdc) { dpix = GetDeviceCaps(hdc, LOGPIXELSX); ReleaseDC(NULL, hdc); PrintDebug(L"System DPI: dpix = %u", dpix); } else { PrintDebug(L"GetDC failed, using default dpi = 96 (error = %lu)", GetLastError()); dpix = 96; } dpi_setscale(dpix); } static int HandleCopyDataMessage(const COPYDATASTRUCT *copy_data) { WCHAR *str = NULL; connection_t *c = NULL; PrintDebug (L"WM_COPYDATA message received. (dwData: %lu, cbData: %lu, lpData: %s)", copy_data->dwData, copy_data->cbData, copy_data->lpData); if (copy_data->cbData >= sizeof(WCHAR) && copy_data->lpData) { str = (WCHAR*) copy_data->lpData; str[copy_data->cbData/sizeof(WCHAR)-1] = L'\0'; /* in case not nul-terminated */ c = GetConnByName(str); } if(copy_data->dwData == WM_OVPN_START && c) { if (!o.silent_connection) ForceForegroundWindow(o.hWnd); StartOpenVPN(c); } else if(copy_data->dwData == WM_OVPN_STOP && c) StopOpenVPN(c); else if(copy_data->dwData == WM_OVPN_RESTART && c) { if (!o.silent_connection) ForceForegroundWindow(o.hWnd); RestartOpenVPN(c); } else if(copy_data->dwData == WM_OVPN_SHOWSTATUS && c->hwndStatus && c) { ForceForegroundWindow(o.hWnd); ShowWindow(c->hwndStatus, SW_SHOW); } else if(copy_data->dwData == WM_OVPN_STOPALL) StopAllOpenVPN(); else if(copy_data->dwData == WM_OVPN_SILENT && str) { if (_wtoi(str) == 0) o.silent_connection = 0; else o.silent_connection = 1; } else if(copy_data->dwData == WM_OVPN_EXIT) { CloseApplication(o.hWnd); } /* Not yet implemented else if(copy_data->dwData == WM_OVPN_IMPORT) { } */ else if (copy_data->dwData == WM_OVPN_NOTIFY) { ShowTrayBalloon(L"", copy_data->lpData); } else { PrintDebug (L"WM_COPYDATA message ignored. (dwData: %lu, cbData: %lu)", copy_data->dwData, copy_data->cbData); } return TRUE; /* indicate we handled the message */ } /* This function is called by the Windows function DispatchMessage() */ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { static UINT s_uTaskbarRestart; switch (message) { case WM_CREATE: /* Save Window Handle */ o.hWnd = hwnd; dpi_initialize(); s_uTaskbarRestart = RegisterWindowMessage(TEXT("TaskbarCreated")); WTSRegisterSessionNotification(hwnd, NOTIFY_FOR_THIS_SESSION); /* Load application icon */ HICON hIcon = LoadLocalizedIcon(ID_ICO_APP); if (hIcon) { SendMessage(hwnd, WM_SETICON, (WPARAM) (ICON_SMALL), (LPARAM) (hIcon)); SendMessage(hwnd, WM_SETICON, (WPARAM) (ICON_BIG), (LPARAM) (hIcon)); } /* Enable next line to accept WM_COPYDATA messages from lower level processes */ #if 0 ChangeWindowMessageFilterEx(hwnd, WM_COPYDATA, MSGFLT_ALLOW, NULL); #endif CreatePopupMenus(); /* Create popup menus */ ShowTrayIcon(); if (o.service_only) CheckServiceStatus(); // Check if service is running or not if (!AutoStartConnections()) { SendMessage(hwnd, WM_CLOSE, 0, 0); break; } break; case WM_NOTIFYICONTRAY: OnNotifyTray(lParam); // Manages message from tray break; case WM_COPYDATA: // custom messages with data from other processes HandleCopyDataMessage((COPYDATASTRUCT*) lParam); return TRUE; /* lets the sender free copy_data */ case WM_COMMAND: if ( (LOWORD(wParam) >= IDM_CONNECTMENU) && (LOWORD(wParam) < IDM_CONNECTMENU + MAX_CONFIGS) ) { StartOpenVPN(&o.conn[LOWORD(wParam) - IDM_CONNECTMENU]); } if ( (LOWORD(wParam) >= IDM_DISCONNECTMENU) && (LOWORD(wParam) < IDM_DISCONNECTMENU + MAX_CONFIGS) ) { StopOpenVPN(&o.conn[LOWORD(wParam) - IDM_DISCONNECTMENU]); } if ( (LOWORD(wParam) >= IDM_RECONNECTMENU) && (LOWORD(wParam) < IDM_RECONNECTMENU + MAX_CONFIGS) ) { RestartOpenVPN(&o.conn[LOWORD(wParam) - IDM_RECONNECTMENU]); } if ( (LOWORD(wParam) >= IDM_STATUSMENU) && (LOWORD(wParam) < IDM_STATUSMENU + MAX_CONFIGS) ) { ShowWindow(o.conn[LOWORD(wParam) - IDM_STATUSMENU].hwndStatus, SW_SHOW); } if ( (LOWORD(wParam) >= IDM_VIEWLOGMENU) && (LOWORD(wParam) < IDM_VIEWLOGMENU + MAX_CONFIGS) ) { ViewLog(LOWORD(wParam) - IDM_VIEWLOGMENU); } if ( (LOWORD(wParam) >= IDM_EDITMENU) && (LOWORD(wParam) < IDM_EDITMENU + MAX_CONFIGS) ) { EditConfig(LOWORD(wParam) - IDM_EDITMENU); } if ( (LOWORD(wParam) >= IDM_CLEARPASSMENU) && (LOWORD(wParam) < IDM_CLEARPASSMENU + MAX_CONFIGS) ) { ResetSavePasswords(&o.conn[LOWORD(wParam) - IDM_CLEARPASSMENU]); } #ifndef DISABLE_CHANGE_PASSWORD if ( (LOWORD(wParam) >= IDM_PASSPHRASEMENU) && (LOWORD(wParam) < IDM_PASSPHRASEMENU + MAX_CONFIGS) ) { ShowChangePassphraseDialog(&o.conn[LOWORD(wParam) - IDM_PASSPHRASEMENU]); } #endif if (LOWORD(wParam) == IDM_IMPORT) { ImportConfigFile(); } if (LOWORD(wParam) == IDM_SETTINGS) { ShowSettingsDialog(); } if (LOWORD(wParam) == IDM_CLOSE) { CloseApplication(hwnd); } if (LOWORD(wParam) == IDM_SERVICE_START) { MyStartService(); } if (LOWORD(wParam) == IDM_SERVICE_STOP) { MyStopService(); } if (LOWORD(wParam) == IDM_SERVICE_RESTART) MyReStartService(); break; case WM_CLOSE: CloseApplication(hwnd); break; case WM_DESTROY: WTSUnRegisterSessionNotification(hwnd); StopAllOpenVPN(); OnDestroyTray(); /* Remove Tray Icon and destroy menus */ PostQuitMessage (0); /* Send a WM_QUIT to the message queue */ break; case WM_QUERYENDSESSION: return(TRUE); case WM_ENDSESSION: StopAllOpenVPN(); OnDestroyTray(); break; case WM_WTSSESSION_CHANGE: switch (wParam) { case WTS_SESSION_LOCK: o.session_locked = TRUE; break; case WTS_SESSION_UNLOCK: o.session_locked = FALSE; if (CountConnState(suspended) != 0) ResumeConnections(); break; } break; default: /* for messages that we don't deal with */ if (message == s_uTaskbarRestart) { /* Explorer has restarted, re-register the tray icon. */ ShowTrayIcon(); CheckAndSetTrayIcon(); break; } return DefWindowProc (hwnd, message, wParam, lParam); } return 0; } static INT_PTR CALLBACK AboutDialogFunc(UNUSED HWND hDlg, UINT msg, UNUSED WPARAM wParam, LPARAM lParam) { LPPSHNOTIFY psn; if (msg == WM_NOTIFY) { psn = (LPPSHNOTIFY) lParam; if (psn->hdr.code == (UINT) PSN_APPLY) return TRUE; } return FALSE; } static void ShowSettingsDialog() { PROPSHEETPAGE psp[4]; int page_number = 0; /* General tab */ psp[page_number].dwSize = sizeof(PROPSHEETPAGE); psp[page_number].dwFlags = PSP_DLGINDIRECT; psp[page_number].hInstance = o.hInstance; psp[page_number].pResource = LocalizedDialogResource(ID_DLG_GENERAL); psp[page_number].pfnDlgProc = GeneralSettingsDlgProc; psp[page_number].lParam = 0; psp[page_number].pfnCallback = NULL; ++page_number; /* Proxy tab */ if (o.service_only == 0) { psp[page_number].dwSize = sizeof(PROPSHEETPAGE); psp[page_number].dwFlags = PSP_DLGINDIRECT; psp[page_number].hInstance = o.hInstance; psp[page_number].pResource = LocalizedDialogResource(ID_DLG_PROXY); psp[page_number].pfnDlgProc = ProxySettingsDialogFunc; psp[page_number].lParam = 0; psp[page_number].pfnCallback = NULL; ++page_number; } /* Advanced tab */ psp[page_number].dwSize = sizeof(PROPSHEETPAGE); psp[page_number].dwFlags = PSP_DLGINDIRECT; psp[page_number].hInstance = o.hInstance; psp[page_number].pResource = LocalizedDialogResource(ID_DLG_ADVANCED); psp[page_number].pfnDlgProc = AdvancedSettingsDlgProc; psp[page_number].lParam = 0; psp[page_number].pfnCallback = NULL; ++page_number; /* About tab */ psp[page_number].dwSize = sizeof(PROPSHEETPAGE); psp[page_number].dwFlags = PSP_DLGINDIRECT; psp[page_number].hInstance = o.hInstance; psp[page_number].pResource = LocalizedDialogResource(ID_DLG_ABOUT); psp[page_number].pfnDlgProc = AboutDialogFunc; psp[page_number].lParam = 0; psp[page_number].pfnCallback = NULL; ++page_number; PROPSHEETHEADER psh; psh.dwSize = sizeof(PROPSHEETHEADER); psh.dwFlags = PSH_USEHICON | PSH_PROPSHEETPAGE | PSH_NOAPPLYNOW | PSH_NOCONTEXTHELP; psh.hwndParent = o.hWnd; psh.hInstance = o.hInstance; psh.hIcon = LoadLocalizedIcon(ID_ICO_APP); psh.pszCaption = LoadLocalizedString(IDS_SETTINGS_CAPTION); psh.nPages = page_number; psh.nStartPage = 0; psh.ppsp = (LPCPROPSHEETPAGE) &psp; psh.pfnCallback = NULL; PropertySheet(&psh); } void CloseApplication(HWND hwnd) { int i; if (o.service_state == service_connected && ShowLocalizedMsgEx(MB_YESNO, _T("Exit OpenVPN"), IDS_NFO_SERVICE_ACTIVE_EXIT) == IDNO) return; for (i = 0; i < o.num_configs; i++) { if (o.conn[i].state == disconnected) continue; /* Ask for confirmation if still connected */ if (ShowLocalizedMsgEx(MB_YESNO, _T("Exit OpenVPN"), IDS_NFO_ACTIVE_CONN_EXIT) == IDNO) return; } DestroyWindow(hwnd); } void ImportConfigFile() { TCHAR filter[2*_countof(o.ext_string)+5]; _sntprintf_0(filter, _T("*.%s%c*.%s%c"), o.ext_string, _T('\0'), o.ext_string, _T('\0')); OPENFILENAME fn; TCHAR source[MAX_PATH] = _T(""); fn.lStructSize = sizeof(OPENFILENAME); fn.hwndOwner = NULL; fn.lpstrFilter = filter; fn.lpstrCustomFilter = NULL; fn.nFilterIndex = 1; fn.lpstrFile = source; fn.nMaxFile = MAX_PATH; fn.lpstrFileTitle = NULL; fn.lpstrInitialDir = NULL; fn.lpstrTitle = NULL; fn.Flags = OFN_DONTADDTORECENT | OFN_FILEMUSTEXIST; fn.lpstrDefExt = NULL; if (GetOpenFileName(&fn)) { TCHAR destination[MAX_PATH]; PTCHAR fileName = source + fn.nFileOffset; _sntprintf_0(destination, _T("%s\\%s"), o.config_dir, fileName); destination[_tcslen(destination) - _tcslen(o.ext_string) - 1] = _T('\0'); if (EnsureDirExists(destination)) { _sntprintf_0(destination, _T("%s\\%s"), destination, fileName); if (!CopyFile(source, destination, TRUE)) { if (GetLastError() == ERROR_FILE_EXISTS) { fileName[_tcslen(fileName) - _tcslen(o.ext_string) - 1] = _T('\0'); ShowLocalizedMsg(IDS_ERR_IMPORT_EXISTS, fileName); return; } } else { ShowLocalizedMsg(IDS_NFO_IMPORT_SUCCESS); return; } } ShowLocalizedMsg(IDS_ERR_IMPORT_FAILED, destination); } } #ifdef DEBUG void PrintDebugMsg(TCHAR *msg) { time_t log_time; struct tm *time_struct; TCHAR date[30]; log_time = time(NULL); time_struct = localtime(&log_time); _sntprintf(date, _countof(date), _T("%d-%.2d-%.2d %.2d:%.2d:%.2d"), time_struct->tm_year + 1900, time_struct->tm_mon + 1, time_struct->tm_mday, time_struct->tm_hour, time_struct->tm_min, time_struct->tm_sec); _ftprintf(o.debug_fp, _T("%s %s\n"), date, msg); fflush(o.debug_fp); } #endif #define PACKVERSION(major,minor) MAKELONG(minor,major) DWORD GetDllVersion(LPCTSTR lpszDllName) { HINSTANCE hinstDll; DWORD dwVersion = 0; /* For security purposes, LoadLibrary should be provided with a fully-qualified path to the DLL. The lpszDllName variable should be tested to ensure that it is a fully qualified path before it is used. */ hinstDll = LoadLibrary(lpszDllName); if(hinstDll) { DLLGETVERSIONPROC pDllGetVersion; pDllGetVersion = (DLLGETVERSIONPROC)GetProcAddress(hinstDll, "DllGetVersion"); /* Because some DLLs might not implement this function, you must test for it explicitly. Depending on the particular DLL, the lack of a DllGetVersion function can be a useful indicator of the version. */ if(pDllGetVersion) { DLLVERSIONINFO dvi; HRESULT hr; ZeroMemory(&dvi, sizeof(dvi)); dvi.cbSize = sizeof(dvi); hr = (*pDllGetVersion)(&dvi); if(SUCCEEDED(hr)) { dwVersion = PACKVERSION(dvi.dwMajorVersion, dvi.dwMinorVersion); } } FreeLibrary(hinstDll); } return dwVersion; }