static UINT parallel_process_irp_read(PARALLEL_DEVICE* parallel, IRP* irp)
{
	UINT32 Length;
	UINT64 Offset;
	ssize_t status;
	BYTE* buffer = NULL;
	if (!Stream_CheckAndLogRequiredLength(TAG, irp->input, 12))
		return ERROR_INVALID_DATA;
	Stream_Read_UINT32(irp->input, Length);
	Stream_Read_UINT64(irp->input, Offset);
	buffer = (BYTE*)malloc(Length);

	if (!buffer)
	{
		WLog_ERR(TAG, "malloc failed!");
		return CHANNEL_RC_NO_MEMORY;
	}

	status = read(parallel->file, buffer, Length);

	if (status < 0)
	{
		irp->IoStatus = STATUS_UNSUCCESSFUL;
		free(buffer);
		buffer = NULL;
		Length = 0;
	}
	else
	{
	}

	Stream_Write_UINT32(irp->output, Length);

	if (Length > 0)
	{
		if (!Stream_EnsureRemainingCapacity(irp->output, Length))
		{
			WLog_ERR(TAG, "Stream_EnsureRemainingCapacity failed!");
			free(buffer);
			return CHANNEL_RC_NO_MEMORY;
		}

		Stream_Write(irp->output, buffer, Length);
	}

	free(buffer);
	return irp->Complete(irp);
}

static UINT rdpdr_process_irp(rdpdrPlugin* rdpdr, wStream* s)
{
	IRP* irp;
	UINT error = CHANNEL_RC_OK;

	WINPR_ASSERT(rdpdr);
	WINPR_ASSERT(s);

	irp = irp_new(rdpdr->devman, rdpdr->pool, s, &error);

	if (!irp)
	{
		...
		return error;
	}

	IFCALLRET(irp->device->IRPRequest, error, irp->device, irp);

	if (error)
		WLog_ERR(TAG, "device->IRPRequest failed with error %" PRIu32 "", error);

	return error;
}

IRP* irp_new(DEVMAN* devman, wStreamPool* pool, wStream* s, UINT* error)
{
	IRP* irp;
	DEVICE* device;
	UINT32 DeviceId;

	WINPR_ASSERT(devman);
	WINPR_ASSERT(pool);
	WINPR_ASSERT(s);

	...

	irp = (IRP*)winpr_aligned_malloc(sizeof(IRP), MEMORY_ALLOCATION_ALIGNMENT);

	if (!irp)
	{
		WLog_ERR(TAG, "_aligned_malloc failed!");
		if (error)
			*error = CHANNEL_RC_NO_MEMORY;
		return NULL;
	}

	ZeroMemory(irp, sizeof(IRP));

	Stream_Read_UINT32(s, irp->FileId);        /* FileId (4 bytes) */
	Stream_Read_UINT32(s, irp->CompletionId);  /* CompletionId (4 bytes) */
	Stream_Read_UINT32(s, irp->MajorFunction); /* MajorFunction (4 bytes) */
	Stream_Read_UINT32(s, irp->MinorFunction); /* MinorFunction (4 bytes) */

	Stream_AddRef(s);
	irp->input = s;
	irp->device = device;
	irp->devman = devman;

	irp->output = StreamPool_Take(pool, 256);
	
  ...

	irp->Complete = irp_complete;
	irp->Discard = irp_free;

	irp->thread = NULL;
	irp->cancelled = FALSE;

	if (error)
		*error = CHANNEL_RC_OK;

	return irp;
}

static UINT parallel_process_irp(PARALLEL_DEVICE* parallel, IRP* irp)
{
	UINT error;

	switch (irp->MajorFunction)
	{
		case IRP_MJ_CREATE:
			if ((error = parallel_process_irp_create(parallel, irp)))
			{
				WLog_ERR(TAG, "parallel_process_irp_create failed with error %" PRIu32 "!", error);
				return error;
			}

			break;

		case IRP_MJ_CLOSE:
			if ((error = parallel_process_irp_close(parallel, irp)))
			{
				WLog_ERR(TAG, "parallel_process_irp_close failed with error %" PRIu32 "!", error);
				return error;
			}

			break;

		case IRP_MJ_READ:
			if ((error = parallel_process_irp_read(parallel, irp)))
			{
				WLog_ERR(TAG, "parallel_process_irp_read failed with error %" PRIu32 "!", error);
				return error;
			}

			break;

		case IRP_MJ_WRITE:
			if ((error = parallel_process_irp_write(parallel, irp)))
			{
				WLog_ERR(TAG, "parallel_process_irp_write failed with error %" PRIu32 "!", error);
				return error;
			}

			break;

		case IRP_MJ_DEVICE_CONTROL:
			if ((error = parallel_process_irp_device_control(parallel, irp)))
			{
				WLog_ERR(TAG, "parallel_process_irp_device_control failed with error %" PRIu32 "!",
				         error);
				return error;
			}

			break;

		default:
			irp->IoStatus = STATUS_NOT_SUPPORTED;
			return irp->Complete(irp);
	}

	return CHANNEL_RC_OK;
}

static UINT parallel_process_irp_create(PARALLEL_DEVICE* parallel, IRP* irp)
{
	char* path = NULL;
	int status;
	WCHAR* ptr;
	UINT32 PathLength;
	
  ...

	Stream_Write_UINT32(irp->output, parallel->id);
	Stream_Write_UINT8(irp->output, 0);
	free(path);
	return irp->Complete(irp);
}
static UINT irp_complete(IRP* irp)
{
	size_t pos;
	rdpdrPlugin* rdpdr;
	UINT error;

	rdpdr = (rdpdrPlugin*)irp->devman->plugin;

	pos = Stream_GetPosition(irp->output);
	Stream_SetPosition(irp->output, RDPDR_DEVICE_IO_RESPONSE_LENGTH - 4);
	Stream_Write_UINT32(irp->output, irp->IoStatus); /* IoStatus (4 bytes) */
	Stream_SetPosition(irp->output, pos);

	error = rdpdr_send(rdpdr, irp->output);
	irp->output = NULL;

	irp_free(irp);
	return error;
}

static UINT drdynvc_process_create_request(drdynvcPlugin* drdynvc, int Sp, int cbChId, wStream* s)
{
	size_t pos;
	UINT status;
	UINT32 ChannelId;
	wStream* data_out;
	UINT channel_status;
	char* name;
	size_t length;
	DVCMAN* dvcman;
	DVCMAN_CHANNEL* channel;
	UINT32 retStatus;

	...

	channel =
	    dvcman_create_channel(drdynvc, drdynvc->channel_mgr, ChannelId, name, &channel_status);
	
  ...

	if (channel_status == CHANNEL_RC_OK)
	{
		if ((status = dvcman_open_channel(drdynvc, channel)))
		{
			WLog_Print(drdynvc->log, WLOG_ERROR,
			           "dvcman_open_channel failed with error %" PRIu32 "!", status);
			return status;
		}
	}

	return status;
}

static DVCMAN_CHANNEL* dvcman_create_channel(drdynvcPlugin* drdynvc,
                                             IWTSVirtualChannelManager* pChannelMgr,
                                             UINT32 ChannelId, const char* ChannelName, UINT* res)
{
	BOOL bAccept;
	DVCMAN_CHANNEL* channel = NULL;
	DrdynvcClientContext* context;
	DVCMAN* dvcman = (DVCMAN*)pChannelMgr;
	DVCMAN_LISTENER* listener;
	IWTSVirtualChannelCallback* pCallback = NULL;

	WINPR_ASSERT(res);

	HashTable_Lock(dvcman->listeners);
	listener = (DVCMAN_LISTENER*)HashTable_GetItemValue(dvcman->listeners, ChannelName);
	if (!listener)
	{
		*res = ERROR_NOT_FOUND;
		goto out;
	}

	channel = dvcman_get_channel_by_id(pChannelMgr, ChannelId, FALSE);
	if (channel)
	{
		switch (channel->state)
		{
			case DVC_CHANNEL_RUNNING:
				WLog_Print(drdynvc->log, WLOG_ERROR,
				           "Protocol error: Duplicated ChannelId %" PRIu32 " (%s)!", ChannelId,
				           ChannelName);
				*res = CHANNEL_RC_ALREADY_OPEN;
				goto out;

			case DVC_CHANNEL_CLOSED:
			case DVC_CHANNEL_INIT:
			default:
				WLog_Print(drdynvc->log, WLOG_ERROR, "not expecting a createChannel from state %d",
				           channel->state);
				*res = CHANNEL_RC_INITIALIZATION_ERROR;
				goto out;
		}
	}
	else
	{
		if (!(channel = dvcman_channel_new(drdynvc, pChannelMgr, ChannelId, ChannelName)))
		{
			WLog_Print(drdynvc->log, WLOG_ERROR, "dvcman_channel_new failed!");
			*res = CHANNEL_RC_NO_MEMORY;
			goto out;
		}
	}

	if (!HashTable_Insert(dvcman->channelsById, &channel->channel_id, channel))
	{
		WLog_Print(drdynvc->log, WLOG_ERROR, "unable to register channel in our channel list");
		*res = ERROR_INTERNAL_ERROR;
		dvcman_channel_free(channel);
		channel = NULL;
		goto out;
	}

	channel->iface.Write = dvcman_write_channel;
	channel->iface.Close = dvcman_close_channel_iface;
	bAccept = TRUE;

	*res = listener->listener_callback->OnNewChannelConnection(
	    listener->listener_callback, &channel->iface, NULL, &bAccept, &pCallback);

	if (*res != CHANNEL_RC_OK)
	{
		WLog_Print(drdynvc->log, WLOG_ERROR,
		           "OnNewChannelConnection failed with error %" PRIu32 "!", *res);
		*res = ERROR_INTERNAL_ERROR;
		dvcman_channel_unref(channel);
		goto out;
	}

	if (!bAccept)
	{
		WLog_Print(drdynvc->log, WLOG_ERROR, "OnNewChannelConnection returned with bAccept FALSE!");
		*res = ERROR_INTERNAL_ERROR;
		dvcman_channel_unref(channel);
		channel = NULL;
		goto out;
	}

	WLog_Print(drdynvc->log, WLOG_DEBUG, "listener %s created new channel %" PRIu32 "",
	           listener->channel_name, channel->channel_id);
	channel->state = DVC_CHANNEL_RUNNING;
	channel->channel_callback = pCallback;
	channel->pInterface = listener->iface.pInterface;
	context = dvcman->drdynvc->context;

	IFCALLRET(context->OnChannelConnected, *res, context, ChannelName, listener->iface.pInterface);
	if (*res != CHANNEL_RC_OK)
	{
		WLog_Print(drdynvc->log, WLOG_ERROR,
		           "context.OnChannelConnected failed with error %" PRIu32 "", *res);
	}

out:
	HashTable_Unlock(dvcman->listeners);

	return channel;
}

static UINT dvcman_write_channel(IWTSVirtualChannel* pChannel, 
																ULONG cbSize, const BYTE* pBuffer,
                                 void* pReserved