/*
* Module Name: instdev.c

* Server device handling routine for the CSR stuff.

* Copyright (c) 1985 - 1999, Microsoft Corporation

* Created: 13-Mar-97

* History:
*   13-Mar-97 created by PaulaT
*/

#include "precomp.h"
#pragma hdrstop

#include "ntuser.h"
#include "dbt.h"
#include "pnpmgr.h"


/*
* User-mode pnp manager (in services.exe) has a message to deliver to an app that has registered for this notification but services.exe isn't
* in WinSta0\Default so we need a csr thread to simply send the message.

* PaulaT 06/04/97
*/
ULONG SrvDeviceEvent(IN OUT PCSR_API_MSG m, IN OUT PCSR_REPLY_STATUS ReplyStatus)
{
    NTSTATUS Status = STATUS_SUCCESS;
    PDEVICEEVENTMSG a = (PDEVICEEVENTMSG)&m->u.ApiMessageData;
    USERTHREAD_USEDESKTOPINFO utudi;

    UNREFERENCED_PARAMETER(ReplyStatus);

    try {
        // Set the desktop to the active desktop before sending the message.
        utudi.hThread = NULL;
        utudi.drdRestore.pdeskRestore = NULL;
        Status = NtUserSetInformationThread(NtCurrentThread(), UserThreadUseActiveDesktop, &utudi, sizeof(utudi));
        if (!NT_SUCCESS(Status)) {
            #if DBG
            KdPrint(("--> SrvDeviceEvent: NtUserSetInformationThread failed %d\n", Status));
            #endif
            goto Clean1;
        }

        // Verify the window handle is still valid, if not, let the caller know
        // so it can be purged from the notification window hand list that the user-mode pnp manager keeps.
        if ((a->hWnd != HWND_BROADCAST) && !IsWindow(a->hWnd)) {
            Status = STATUS_INVALID_HANDLE;
            goto Clean0;
        }

        if (a->dwFlags) {
            // This is a query so we have to send the message but use timeouts so an app can't stall us forever.
            RIPMSG3(RIP_VERBOSE, "--> SrvDeviceEvent: Sending WM_DEVICECHANGE to 0x%x, w 0x%x, l 0x%x", (ULONG_PTR)a->hWnd, a->wParam, a->lParam);
            if (!SendMessageTimeout(a->hWnd, WM_DEVICECHANGE, a->wParam, a->lParam, SMTO_ABORTIFHUNG | SMTO_NORMAL, PNP_NOTIFY_TIMEOUT, &a->dwResult)) {
                Status = STATUS_UNSUCCESSFUL;
            }
        } else {
            // It's not a query so just post it and return, we don't care what the app returns.
            RIPMSG3(RIP_VERBOSE, "--> SrvDeviceEvent: Posting WM_DEVICECHANGE to 0x%x, w 0x%x, l 0x%x", (ULONG_PTR)a->hWnd, a->wParam, a->lParam);
            if (!PostMessage(a->hWnd, WM_DEVICECHANGE, a->wParam, a->lParam)) {
                Status = STATUS_UNSUCCESSFUL;
            }
        }

    Clean0:
        // Reset this thread's desktop back to NULL before returning. This decrements the desktop's reference count.
        NtUserSetInformationThread(NtCurrentThread(), UserThreadUseDesktop, &utudi, sizeof(utudi));

    Clean1:
        ;
    } except (EXCEPTION_EXECUTE_HANDLER) {
        KdPrint(("SrvDeviceEvent generated an exception (%d)\n", GetExceptionCode()));
        Status = STATUS_UNSUCCESSFUL;
    }

    return Status;
} // SrvDeviceEvent