UINT __stdcall CreateScheduledTaskCA()

in installer/PowerToysSetupCustomActions/CustomAction.cpp [195:458]


UINT __stdcall CreateScheduledTaskCA(MSIHANDLE hInstall)
{
    HRESULT hr = S_OK;
    UINT er = ERROR_SUCCESS;

    TCHAR username_domain[USERNAME_DOMAIN_LEN];
    TCHAR username[USERNAME_LEN];

    std::wstring wstrTaskName;

    ITaskService* pService = nullptr;
    ITaskFolder* pTaskFolder = nullptr;
    ITaskDefinition* pTask = nullptr;
    IRegistrationInfo* pRegInfo = nullptr;
    ITaskSettings* pSettings = nullptr;
    ITriggerCollection* pTriggerCollection = nullptr;
    IRegisteredTask* pRegisteredTask = nullptr;
    IPrincipal* pPrincipal = nullptr;
    ITrigger* pTrigger = nullptr;
    ILogonTrigger* pLogonTrigger = nullptr;
    IAction* pAction = nullptr;
    IActionCollection* pActionCollection = nullptr;
    IExecAction* pExecAction = nullptr;

    LPWSTR wszExecutablePath = nullptr;

    hr = WcaInitialize(hInstall, "CreateScheduledTaskCA");
    ExitOnFailure(hr, "Failed to initialize");

    WcaLog(LOGMSG_STANDARD, "Initialized.");

    // ------------------------------------------------------
    // Get the Domain/Username for the trigger.
    //
    // This action needs to run as the system to get elevated privileges from the installation,
    // so GetUserNameEx can't be used to get the current user details.
    // The USERNAME and USERDOMAIN environment variables are used instead.
    if (!GetEnvironmentVariable(L"USERNAME", username, USERNAME_LEN))
    {
        ExitWithLastError(hr, "Getting username failed: %x", hr);
    }
    if (!GetEnvironmentVariable(L"USERDOMAIN", username_domain, USERNAME_DOMAIN_LEN))
    {
        ExitWithLastError(hr, "Getting the user's domain failed: %x", hr);
    }
    wcscat_s(username_domain, L"\\");
    wcscat_s(username_domain, username);

    WcaLog(LOGMSG_STANDARD, "Current user detected: %ls", username_domain);

    // Task Name.
    wstrTaskName = L"Autorun for ";
    wstrTaskName += username;

    // Get the executable path passed to the custom action.
    hr = WcaGetProperty(L"CustomActionData", &wszExecutablePath);
    ExitOnFailure(hr, "Failed to get the executable path from CustomActionData.");

    // COM and Security Initialization is expected to have been done by the MSI.
    // It couldn't be done in the DLL, anyway.
    // ------------------------------------------------------
    // Create an instance of the Task Service.
    hr = CoCreateInstance(CLSID_TaskScheduler,
                          nullptr,
                          CLSCTX_INPROC_SERVER,
                          IID_ITaskService,
                          (void**)&pService);
    ExitOnFailure(hr, "Failed to create an instance of ITaskService: %x", hr);

    // Connect to the task service.
    hr = pService->Connect(_variant_t(), _variant_t(), _variant_t(), _variant_t());
    ExitOnFailure(hr, "ITaskService::Connect failed: %x", hr);

    // ------------------------------------------------------
    // Get the PowerToys task folder. Creates it if it doesn't exist.
    hr = pService->GetFolder(_bstr_t(L"\\PowerToys"), &pTaskFolder);
    if (FAILED(hr))
    {
        // Folder doesn't exist. Get the Root folder and create the PowerToys subfolder.
        ITaskFolder* pRootFolder = nullptr;
        hr = pService->GetFolder(_bstr_t(L"\\"), &pRootFolder);
        ExitOnFailure(hr, "Cannot get Root Folder pointer: %x", hr);
        hr = pRootFolder->CreateFolder(_bstr_t(L"\\PowerToys"), _variant_t(L""), &pTaskFolder);
        if (FAILED(hr))
        {
            pRootFolder->Release();
            ExitOnFailure(hr, "Cannot create PowerToys task folder: %x", hr);
        }
        WcaLog(LOGMSG_STANDARD, "PowerToys task folder created.");
    }

    // If the same task exists, remove it.
    pTaskFolder->DeleteTask(_bstr_t(wstrTaskName.c_str()), 0);

    // Create the task builder object to create the task.
    hr = pService->NewTask(0, &pTask);
    ExitOnFailure(hr, "Failed to create a task definition: %x", hr);

    // ------------------------------------------------------
    // Get the registration info for setting the identification.
    hr = pTask->get_RegistrationInfo(&pRegInfo);
    ExitOnFailure(hr, "Cannot get identification pointer: %x", hr);
    hr = pRegInfo->put_Author(_bstr_t(username_domain));
    ExitOnFailure(hr, "Cannot put identification info: %x", hr);

    // ------------------------------------------------------
    // Create the settings for the task
    hr = pTask->get_Settings(&pSettings);
    ExitOnFailure(hr, "Cannot get settings pointer: %x", hr);

    hr = pSettings->put_StartWhenAvailable(VARIANT_FALSE);
    ExitOnFailure(hr, "Cannot put_StartWhenAvailable setting info: %x", hr);
    hr = pSettings->put_StopIfGoingOnBatteries(VARIANT_FALSE);
    ExitOnFailure(hr, "Cannot put_StopIfGoingOnBatteries setting info: %x", hr);
    hr = pSettings->put_ExecutionTimeLimit(_bstr_t(L"PT0S")); //Unlimited
    ExitOnFailure(hr, "Cannot put_ExecutionTimeLimit setting info: %x", hr);
    hr = pSettings->put_DisallowStartIfOnBatteries(VARIANT_FALSE);
    ExitOnFailure(hr, "Cannot put_DisallowStartIfOnBatteries setting info: %x", hr);

    // ------------------------------------------------------
    // Get the trigger collection to insert the logon trigger.
    hr = pTask->get_Triggers(&pTriggerCollection);
    ExitOnFailure(hr, "Cannot get trigger collection: %x", hr);

    // Add the logon trigger to the task.
    hr = pTriggerCollection->Create(TASK_TRIGGER_LOGON, &pTrigger);
    ExitOnFailure(hr, "Cannot create the trigger: %x", hr);

    hr = pTrigger->QueryInterface(
        IID_ILogonTrigger, (void**)&pLogonTrigger);
    pTrigger->Release();
    ExitOnFailure(hr, "QueryInterface call failed for ILogonTrigger: %x", hr);

    hr = pLogonTrigger->put_Id(_bstr_t(L"Trigger1"));
    if (FAILED(hr))
    {
        WcaLogError(hr, "Cannot put the trigger ID: %x", hr);
    }

    // Timing issues may make explorer not be started when the task runs.
    // Add a little delay to mitigate this.
    hr = pLogonTrigger->put_Delay(_bstr_t(L"PT03S"));
    if (FAILED(hr))
    {
        WcaLogError(hr, "Cannot put the trigger delay: %x", hr);
    }

    // Define the user. The task will execute when the user logs on.
    // The specified user must be a user on this computer.
    hr = pLogonTrigger->put_UserId(_bstr_t(username_domain));
    pLogonTrigger->Release();
    ExitOnFailure(hr, "Cannot add user ID to logon trigger: %x", hr);

    // ------------------------------------------------------
    // Add an Action to the task. This task will execute the path passed to this custom action.

    // Get the task action collection pointer.
    hr = pTask->get_Actions(&pActionCollection);
    ExitOnFailure(hr, "Cannot get Task collection pointer: %x", hr);

    // Create the action, specifying that it is an executable action.
    hr = pActionCollection->Create(TASK_ACTION_EXEC, &pAction);
    pActionCollection->Release();
    ExitOnFailure(hr, "Cannot create the action: %x", hr);

    // QI for the executable task pointer.
    hr = pAction->QueryInterface(
        IID_IExecAction, (void**)&pExecAction);
    pAction->Release();
    ExitOnFailure(hr, "QueryInterface call failed for IExecAction: %x", hr);

    // Set the path of the executable to PowerToys (passed as CustomActionData).
    hr = pExecAction->put_Path(_bstr_t(wszExecutablePath));
    pExecAction->Release();
    ExitOnFailure(hr, "Cannot set path of executable: %x", hr);

    // ------------------------------------------------------
    // Create the principal for the task
    hr = pTask->get_Principal(&pPrincipal);
    ExitOnFailure(hr, "Cannot get principal pointer: %x", hr);

    // Set up principal information:
    hr = pPrincipal->put_Id(_bstr_t(L"Principal1"));
    if (FAILED(hr))
    {
        WcaLogError(hr, "Cannot put the principal ID: %x", hr);
    }

    hr = pPrincipal->put_UserId(_bstr_t(username_domain));
    if (FAILED(hr))
    {
        WcaLogError(hr, "Cannot put principal user Id: %x", hr);
    }

    hr = pPrincipal->put_LogonType(TASK_LOGON_INTERACTIVE_TOKEN);
    if (FAILED(hr))
    {
        WcaLogError(hr, "Cannot put principal logon type: %x", hr);
    }

    // Run the task with the highest available privileges.
    hr = pPrincipal->put_RunLevel(TASK_RUNLEVEL_LUA);
    pPrincipal->Release();
    ExitOnFailure(hr, "Cannot put principal run level: %x", hr);

    // ------------------------------------------------------
    //  Save the task in the PowerToys folder.
    {
        _variant_t SDDL_FULL_ACCESS_FOR_EVERYONE = L"D:(A;;FA;;;WD)";
        hr = pTaskFolder->RegisterTaskDefinition(
            _bstr_t(wstrTaskName.c_str()),
            pTask,
            TASK_CREATE_OR_UPDATE,
            _variant_t(username_domain),
            _variant_t(),
            TASK_LOGON_INTERACTIVE_TOKEN,
            SDDL_FULL_ACCESS_FOR_EVERYONE,
            &pRegisteredTask);
        ExitOnFailure(hr, "Error saving the Task : %x", hr);
    }

    WcaLog(LOGMSG_STANDARD, "Scheduled task created for the current user.");

LExit:
    ReleaseStr(wszExecutablePath);
    if (pService)
    {
        pService->Release();
    }
    if (pTaskFolder)
    {
        pTaskFolder->Release();
    }
    if (pTask)
    {
        pTask->Release();
    }
    if (pRegInfo)
    {
        pRegInfo->Release();
    }
    if (pSettings)
    {
        pSettings->Release();
    }
    if (pTriggerCollection)
    {
        pTriggerCollection->Release();
    }
    if (pRegisteredTask)
    {
        pRegisteredTask->Release();
    }

    if (!SUCCEEDED(hr))
    {
        PMSIHANDLE hRecord = MsiCreateRecord(0);
        MsiRecordSetString(hRecord, 0, TEXT("Failed to create a scheduled task to start PowerToys at user login. You can re-try to create the scheduled task using the PowerToys settings."));
        MsiProcessMessage(hInstall, INSTALLMESSAGE(INSTALLMESSAGE_WARNING + MB_OK), hRecord);
    }

    er = SUCCEEDED(hr) ? ERROR_SUCCESS : ERROR_INSTALL_FAILURE;
    return WcaFinalize(er);
}