IOCTL_BTH_GET_DEVICE_INFO IOCTL (bthioctl.h)

Article
05/18/2021

The IOCTL_BTH_GET_DEVICE_INFO request returns information about all cached, previously discovered remote radios that are Bluetooth-enabled.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

The AssociatedIrp.SystemBuffer member points to a buffer for a BTH_DEVICE_INFO_LIST structure.

Input buffer length

The length of a BTH_DEVICE_INFO_LIST structure

Output buffer

The AssociatedIrp.SystemBuffer member points to a buffer that holds a BTH_DEVICE_INFO_LIST structure. The numOfDevices member of the BTH_DEVICE_INFO_LIST structure contains the number of devices for which there is information and an array of BTH_DEVICE_INFO structures; one array entry for each device.

Output buffer length

If the size of the passed output buffer is not exactly sizeof(BTH_DEVICE_INFO_LIST) plus the correct multiple of sizeof(BTH_DEVICE_INFO), the request will fail with STATUS_INVALID_BUFFER_SIZE.

Status block

If the request is successful, the Information member of the STATUS_BLOCK structure is set to the size, in bytes, of the buffer that holds information about the array of devices. The BTH_DEVICE_INFO_LIST structure contains storage for the first BTH_DEVICE_INFO structure, so if no devices are returned, the Information member is set to the size of the first structure.

The Status member is set to one of the values in the following table.

Status value	Description
STATUS_SUCCESS	The IOCTL completed successfully.
STATUS_INVALID_PARAMETER	The input buffer passed in was NULL.
STATUS_INVALID_BUFFER_SIZE	The output buffer was not sized correctly.

Remarks

The IOCTL_BTH_GET_DEVICE_INFO IOCTL provides information about all previously discovered remote radios.

The numOfDevices member of the BTH_DEVICE_INFO_LIST structure returns the total number of BTH_DEVICE_INFO structures that are returned by the IOCTL. If the calling driver passes in a buffer that is smaller than the value of the numOfDevices member, only a portion of the available structures will be returned. Bluetooth driver developers should call IOCTL_BTH_GET_DEVICE_INFO with a small buffer first, for example sizeof(BTH_DEVICE_INFO_LIST), and then use the returned numOfDevices member to correctly size the buffer for a subsequent call.

The BTH_DEVICE_INFO_LIST structure includes storage for the first BTH_DEVICE_INFO structure. Use the following formula to calculate the correct buffer size for a call to IOCTL_BTH_GET_DEVICE_INFO: Buffer=sizeof(BTH_DEVICE_INFO_LIST)+(NumOfDevices-1)*sizeof(BTH_DEVICE_INFO).

Requirements

Requirement	Value
Minimum supported client	Versions:_Supported in Windows Vista, and later.
Header	bthioctl.h (include Bthioctl.h)
IRQL	<= PASSIVE_LEVEL