Thank you a lot! That was real misunderstanding. IOServiceGetMatchingServices(kIOMasterPortDefault, cfd, &iterator) returns nil iterator for existing extension name. The extension state is [activated enabled]. What can be a reason ?

eskimo, thanks! I tried to create different projects and found, that availability of different header files depends on XCode project type. I'm testing USBDriver sample project and included ICScannerDevice.h, which seems to be application side class and not accessible for drivers. (assert.h is called from ICScannerDevice indirectly)