USB mass storage vs USB HID

[Subrat Patnaik]

hi all, i have an application which requires to monitor USB activities(only USB mass storage devices). i need a small help on how to differentiate between USB mass storage devices and USB Mouse/Keyboard/Printer (USB HUMAN INTERFACE DEVICES) etc... could it be done through device ID?? some code will help a great deal... Thank You all.

[_Superman_]

In USB terminology, an interface is what we normally would call a device. For example, a printer can have a scanner and mass storage in a single unit. Each interface has a property called an interface class. For mass storage, this property will have a value of 8. You can see a list here - http://www.usb.org/developers/defined_class[^] You can get this by reading the configuration descriptor of the device.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Polymorphism in C

[Subrat Patnaik]

Hi _Superman_, i already know the device descriptor properties... however, if i could get some code help it would be great....code on how to enumerate the base class of a USB device....

[_Superman_]

The interface class is one of the fields in the interface descriptor. The field name is bInterfaceClass. So after you get the interface descriptor, check if bInterfaceClass is 8 for Mass Storage.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Polymorphism in C