Get the class name of IOKit userclient connections using mach_port_kobject_description

classForConnection.c

kern_return_t classForConnection(io_connect_t client, io_name_t cls)
{
	kern_return_t (*mach_port_kobject_description)(mach_port_t, mach_port_t, uint32_t*, mach_vm_address_t*, char*);
	void* handle = dlopen("/usr/lib/system/libsystem_kernel.dylib", RTLD_NOLOAD);
	mach_port_kobject_description = (__typeof mach_port_kobject_description)dlsym(handle, "mach_port_kobject_description");
	if (!mach_port_kobject_description)
		return KERN_NOT_SUPPORTED;

	char desc[512] = {0};
	uint32_t type = 0;
	mach_vm_address_t addr = 0;

	kern_return_t kr = mach_port_kobject_description(mach_task_self(), client, &type, &addr, desc);
	if (kr != KERN_SUCCESS)
		return kr;
	
	strlcpy(cls, desc, strchr(desc, '(') - desc + 1);
	return KERN_SUCCESS;
}