void MSWindowsWatchdog::mainLoop(void*) { shutdownExistingProcesses(); SendSas sendSasFunc = NULL; HINSTANCE sasLib = LoadLibrary("sas.dll"); if (sasLib) { LOG((CLOG_DEBUG "found sas.dll")); sendSasFunc = (SendSas)GetProcAddress(sasLib, "SendSAS"); } SECURITY_ATTRIBUTES saAttr; saAttr.nLength = sizeof(SECURITY_ATTRIBUTES); saAttr.bInheritHandle = TRUE; saAttr.lpSecurityDescriptor = NULL; if (!CreatePipe(&m_stdOutRead, &m_stdOutWrite, &saAttr, 0)) { throw XArch(new XArchEvalWindows()); } ZeroMemory(&m_processInfo, sizeof(PROCESS_INFORMATION)); while (m_monitoring) { try { if (m_processRunning && getCommand().empty()) { LOG((CLOG_INFO "process started but command is empty, shutting down")); shutdownExistingProcesses(); m_processRunning = false; continue; } if (m_processFailures != 0) { // increasing backoff period, maximum of 10 seconds. int timeout = (m_processFailures * 2) < 10 ? (m_processFailures * 2) : 10; LOG((CLOG_INFO "backing off, wait=%ds, failures=%d", timeout, m_processFailures)); ARCH->sleep(timeout); } if (!getCommand().empty() && ((m_processFailures != 0) || m_session.hasChanged() || m_commandChanged)) { startProcess(); } if (m_processRunning && !isProcessActive()) { m_processFailures++; m_processRunning = false; LOG((CLOG_WARN "detected application not running, pid=%d", m_processInfo.dwProcessId)); } if (sendSasFunc != NULL) { HANDLE sendSasEvent = CreateEvent(NULL, FALSE, FALSE, "Global\\SendSAS"); if (sendSasEvent != NULL) { // use SendSAS event to wait for next session (timeout 1 second). if (WaitForSingleObject(sendSasEvent, 1000) == WAIT_OBJECT_0) { LOG((CLOG_DEBUG "calling SendSAS")); sendSasFunc(FALSE); } CloseHandle(sendSasEvent); continue; } } // if the sas event failed, wait by sleeping. ARCH->sleep(1); } catch (std::exception& e) { LOG((CLOG_ERR "failed to launch, error: %s", e.what())); m_processFailures++; m_processRunning = false; continue; } catch (...) { LOG((CLOG_ERR "failed to launch, unknown error.")); m_processFailures++; m_processRunning = false; continue; } } if (m_processRunning) { LOG((CLOG_DEBUG "terminated running process on exit")); shutdownProcess(m_processInfo.hProcess, m_processInfo.dwProcessId, 20); } LOG((CLOG_DEBUG "watchdog main thread finished")); }
void CMSWindowsRelauncher::mainLoop(void*) { shutdownExistingProcesses(); SendSas sendSasFunc = NULL; HINSTANCE sasLib = LoadLibrary("sas.dll"); if (sasLib) { LOG((CLOG_DEBUG "found sas.dll")); sendSasFunc = (SendSas)GetProcAddress(sasLib, "SendSAS"); } DWORD sessionId = -1; bool launched = false; SECURITY_ATTRIBUTES saAttr; saAttr.nLength = sizeof(SECURITY_ATTRIBUTES); saAttr.bInheritHandle = TRUE; saAttr.lpSecurityDescriptor = NULL; if (!CreatePipe(&m_stdOutRead, &m_stdOutWrite, &saAttr, 0)) { throw XArch(new XArchEvalWindows()); } PROCESS_INFORMATION pi; ZeroMemory(&pi, sizeof(PROCESS_INFORMATION)); int failures = 0; while (m_running) { HANDLE sendSasEvent = 0; if (sasLib && sendSasFunc) { // can't we just create one event? seems weird creating a new // event every second... sendSasEvent = CreateEvent(NULL, FALSE, FALSE, "Global\\SendSAS"); } DWORD newSessionId = getSessionId(); bool running = false; if (launched) { DWORD exitCode; GetExitCodeProcess(pi.hProcess, &exitCode); running = (exitCode == STILL_ACTIVE); if (!running) { failures++; LOG((CLOG_INFO "detected application not running, pid=%d, failures=%d", pi.dwProcessId, failures)); // increasing backoff period, maximum of 10 seconds. int timeout = (failures * 2) < 10 ? (failures * 2) : 10; LOG((CLOG_DEBUG "waiting, backoff period is %d seconds", timeout)); ARCH->sleep(timeout); // double check, in case process started after we waited. GetExitCodeProcess(pi.hProcess, &exitCode); running = (exitCode == STILL_ACTIVE); } else { // reset failures when running. failures = 0; } } // only enter here when id changes, and the session isn't -1, which // may mean that there is no active session. bool sessionChanged = ((newSessionId != sessionId) && (newSessionId != -1)); // relaunch if it was running but has stopped unexpectedly. bool stoppedRunning = (launched && !running); if (stoppedRunning || sessionChanged || m_commandChanged) { m_commandChanged = false; if (launched) { LOG((CLOG_DEBUG "closing existing process to make way for new one")); shutdownProcess(pi.hProcess, pi.dwProcessId, 20); launched = false; } // ok, this is now the active session (forget the old one if any) sessionId = newSessionId; SECURITY_ATTRIBUTES sa; ZeroMemory(&sa, sizeof(SECURITY_ATTRIBUTES)); // get the token for the user in active session, which is the // one receiving input from mouse and keyboard. HANDLE userToken = getCurrentUserToken(sessionId, &sa); if (userToken != 0) { LOG((CLOG_DEBUG "got user token to launch new process")); std::string cmd = command(); if (cmd == "") { // this appears on first launch when the user hasn't configured // anything yet, so don't show it as a warning, only show it as // debug to devs to let them know why nothing happened. LOG((CLOG_DEBUG "nothing to launch, no command specified.")); continue; } // in case reusing process info struct ZeroMemory(&pi, sizeof(PROCESS_INFORMATION)); STARTUPINFO si; ZeroMemory(&si, sizeof(STARTUPINFO)); si.cb = sizeof(STARTUPINFO); si.lpDesktop = "winsta0\\default"; si.hStdError = m_stdOutWrite; si.hStdOutput = m_stdOutWrite; si.dwFlags |= STARTF_USESTDHANDLES; LPVOID environment; BOOL blockRet = CreateEnvironmentBlock(&environment, userToken, FALSE); if (!blockRet) { LOG((CLOG_ERR "could not create environment block (error: %i)", GetLastError())); continue; } else { DWORD creationFlags = NORMAL_PRIORITY_CLASS | CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT; // re-launch in current active user session LOG((CLOG_INFO "starting new process")); BOOL createRet = CreateProcessAsUser( userToken, NULL, LPSTR(cmd.c_str()), &sa, NULL, TRUE, creationFlags, environment, NULL, &si, &pi); DestroyEnvironmentBlock(environment); CloseHandle(userToken); if (!createRet) { LOG((CLOG_ERR "could not launch (error: %i)", GetLastError())); continue; } else { LOG((CLOG_DEBUG "launched in session %i (cmd: %s)", sessionId, cmd.c_str())); launched = true; } } } } if (sendSasEvent) { // use SendSAS event to wait for next session. if (WaitForSingleObject(sendSasEvent, 1000) == WAIT_OBJECT_0 && sendSasFunc) { LOG((CLOG_DEBUG "calling SendSAS")); sendSasFunc(FALSE); } CloseHandle(sendSasEvent); } else { // check for session change every second. ARCH->sleep(1); } } if (launched) { LOG((CLOG_DEBUG "terminated running process on exit")); shutdownProcess(pi.hProcess, pi.dwProcessId, 20); } LOG((CLOG_DEBUG "relauncher main thread finished")); }