Re: [ros-dev] [ros-diffs] [janderwald] 73016: [USBAUDIO] - implement retrieving string descriptor of product and store it in registry.

[Thomas Faber]

On 2016-10-21 23:15, janderwald(a)svn.reactos.org wrote:
>    NTSTATUS
>  +NTAPI
>  +USBAudioGetDescriptor(
>  +    IN PDEVICE_OBJECT DeviceObject,
>  +    IN UCHAR DescriptorType,
>  +    IN ULONG DescriptorLength,
>  +    IN UCHAR DescriptorIndex,
>  +    IN LANGID LanguageId,
>  +    OUT PVOID *OutDescriptor)
>  +{
>  +    PURB Urb;
>  +    NTSTATUS Status;
>  +    PVOID Descriptor;
>  +
>  +    /* sanity checks */
>  +    ASSERT(DeviceObject);
>  +    ASSERT(OutDescriptor);
>  +    ASSERT(DescriptorLength);
>  +
>  +    //
>  +    // first allocate descriptor buffer
>  +    //
>  +    Descriptor = AllocFunction(DescriptorLength);
>  +    if (!Descriptor)
>  +    {
>  +        /* no memory */
>  +        return STATUS_INSUFFICIENT_RESOURCES;
>  +    }
>  +
>  +    /* allocate urb */
>  +    Urb = (PURB)AllocFunction(sizeof(URB));
>  +    if (!Urb)
>  +    {
>  +        /* no memory */
>  +        FreeFunction(Descriptor);
>  +        return STATUS_INSUFFICIENT_RESOURCES;
>  +    }
>  +
>  +    /* initialize urb */
>  +    UsbBuildGetDescriptorRequest(Urb,
>  +        sizeof(Urb->UrbControlDescriptorRequest),
>  +        DescriptorType,
>  +        DescriptorIndex,
>  +        LanguageId,
>  +        Descriptor,
>  +        NULL,
>  +        DescriptorLength,
>  +        NULL);
>  +
>  +    /* submit urb */
>  +    Status = SubmitUrbSync(DeviceObject, Urb);
>  +
>  +    /* free urb */
>  +    FreeFunction(Urb);
>  +
>  +    if (NT_SUCCESS(Status))
>  +    {
>  +        /* store result */
>  +        *OutDescriptor = Descriptor;
>  +    } 
Is Descriptor leaked in the failure case, or does something down the
stack take care of that?

>   +
>  +    /* done */
>  +    return Status;
>  +} 


>   +NTSTATUS
>  +USBAudioRegCreateMediaCategoriesKey(
>  +    IN PUNICODE_STRING Name,
>  +    OUT PHANDLE OutHandle)
>  +{
>  +    NTSTATUS Status;
>  +    OBJECT_ATTRIBUTES ObjectAttributes;
>  +    UNICODE_STRING DestinationString;
>  +    HANDLE Handle;
>  +
>  +    /* initialize root name*/
>  +    RtlInitUnicodeString(&DestinationString,
> L"\\Registry\\Machine\\SYSTEM\\CurrentControlSet\\Control\\MediaCategories\\");
>  +
>  +    /* initialize object attributes */
>  +    InitializeObjectAttributes(&ObjectAttributes, &DestinationString,
> OBJ_CASE_INSENSITIVE | OBJ_OPENIF, NULL, NULL); 
You're missing OBJ_KERNEL_HANDLE.

>   +
>  +    /* create the key */
>  +    Status = ZwOpenKey(&Handle, KEY_ALL_ACCESS, &ObjectAttributes);
>  +    if (NT_SUCCESS(Status))
>  +    {
>  +        /* initialize object attributes */
>  +        InitializeObjectAttributes(&ObjectAttributes, Name, OBJ_CASE_INSENSITIVE,
> Handle, NULL); 
Here too.

>   +
>  +        Status = ZwCreateKey(OutHandle, KEY_ALL_ACCESS, &ObjectAttributes, 0, NULL,
> 0, NULL);
>  +        ZwClose(Handle);
>  +
>  +    }
>  +    return Status;
>  +} 

Thanks.
-Thomas