Enumdisk sample for Enumerating Disk Devices

 

Summary

Win32 applications can use the SetupDi APIs to enumerate all the devices that are available in the system. The Enumdisk.exe sample demonstrates this technique by enumerating all the disk devices regardless of the disk type. The sample also obtains a handle to the device to send IOCTL commands to get the adapter and device properties. Further, this communicates to the device by sending a small computer system interface (SCSI) pass-through command to get the Inquiry data.

 

Device Enumeration

The Enumdisk.exe sample uses the Setup class GUID_DEVCLASS_DISKDRIVE GUID to enumerate all the disk devices that are installed in the system. The sample then obtains the Device ID by getting the Registry properties.

 

The handle to the device is needed to send IOCTLs from a Win32 application. The device handle can be obtained by opening the device with the device interface name. The disk class driver exposes this interface by registering the device interface. It uses the DiskClassGuid interface GUID for device registration. A Win32 application can obtain this interface name by using the SetupDi APIs with the same interface GUID. By performing this in a loop, all the registered disk interfaces can be obtained. Because this value is obtained from the disk class driver, this technique works for all types of disk devices, such as SCSI, Integrated Device Electronics (IDE), Universal Serial Bus (USB), and Institute for Electrical and Electronics Engineers (IEEE) 1394.

 

Device Properties

IOCTL_STORAGE_QUERY_PROPERTY can be used to get the adapter and device properties, respectively. This IOCTL takes the STORAGE_PROPERTY_QUERY data structure as an argument.

Before calling this IOCTL, the STORAGE_PROPERTY_ID and STORAGE_QUERY_TYPE members must be set accordingly. The STORAGE_PROPERTY_ID can be set to either StorageAdapterProperty or StorageDeviceProperty, and it determines the property to be returned. This data structure and its member values are defined in \Ntddk\Src\Ntddstor.h.

 

Calling this StorageAdapterProperty IOCTL returns the STORAGE_ADAPTER_DESCRIPTOR data structure, which contains such adapter properties as the Bus Type, Maximum Transfer Length, Alignment Mask, and so on. StorageDeviceProperty returns the STORAGE_DEVICE_DESCRIPTOR data structure, which contains the Device Type, Vendor ID, Product ID, and so on. This information is obtained from the respective port driver.

 

 

SCSI Pass Through Interface

 

The device handle obtained in this way can also be used to send SCSI pass-through commands to the device. The sample sends the Inquiry command to the device to get the Inquiry data. Refer to the SPTI sample, which is available in the Windows 2000 DDK, for more information on the SCSI pass-through interface.

 

Building the Sample

Click the Free Build Environment or Checked Build Environment icon under the Development Kits program group to set the basic environment variables that are needed by the build utility.

Change to the directory containing the device source code, such as cd c:\enumdisk

Run build -ceZ, or use the BLD macro. This method invokes the Microsoft make routines that produce log files named Buildxxx.log, Buildxxx.wrn, and Buildxxx.err if there are any warnings or errors. Note that xxx stands for "fre" or "chk" depending on the environment chosen. If the build succeeds, the executable Enumdisk.exe file is placed in a platform-specific subfolder of your %TargetPath% folder that is specified in the Sources file.

 

Running the Enumdisk.EXE sample

This sample does not require any arguments. Just run the sample from a command-prompt window; all the disk device properties will be listed.

 

CODE TOUR

 File Manifest

File           Description
 
Enumdisk.c     Implements the Win32 application to enumerate the disk devices.
Enumdisk.h     Header file for Enumdisk.c
Sources        DDK build instructions
Enumdisk.htm   The documentation for these samples (this file)