OSX: how to get volume name (or bsd name) from IOUSBDeviceInterface identifier or location

Question

I am trying to write an application that associates a specific USB line descriptor (USB storage device) with its volume name or bsd.

Thus, the code passes through all connected USB devices, receives line descriptors and extracts information from one of them. I would like to get the volume name of these USB devices. I can not find a suitable API for this. I tried to do this:

DASessionRef session = DASessionCreate(kCFAllocatorDefault);
DADiskRef disk_ref = DADiskCreateFromIOMedia(kCFAllocatorDefault, 
                                             session,
                                             usb_device_ref);
const char* name = DADiskGetBSDName(disk_ref);

But the DADiskCreateFromIOMedia function returned nil, I assume that the usb_device_ref passed by me was incompatible with the io_service_t that the function expects.

So how can I get the volume name of a USB device?

Can I use a location id for this?

Thanks for reading. -L

FOO_Result              result = FOO_SUCCESS;
mach_port_t             master_port;
kern_return_t           k_result;
io_iterator_t           iterator = 0;
io_service_t            usb_device_ref;
CFMutableDictionaryRef  matching_dictionary = NULL; 

// first create a master_port
if (FOO_FAILED(k_result = IOMasterPort(MACH_PORT_NULL, &master_port))) {
    fprintf(stderr, "could not create master port, err = %d\n", k_result);
    goto cleanup;
}
if ((matching_dictionary = IOServiceMatching(kIOUSBDeviceClassName)) == NULL)
{
    fprintf(stderr, "could not create matching dictionary, err = %d\n", k_result);
    goto cleanup;
}
if (FOO_FAILED(k_result = IOServiceGetMatchingServices(master_port, matching_dictionary, &iterator))) {
    fprintf(stderr, "could not find any matching services, err = %d\n", k_result);
    goto cleanup;
}
while (usb_device_ref = IOIteratorNext(iterator))
{       
    IOReturn                        err;
    IOCFPlugInInterface             **iodev;        // requires <IOKit/IOCFPlugIn.h>
    IOUSBDeviceInterface            **dev;
    SInt32                          score;

    err = IOCreatePlugInInterfaceForService(usb_device_ref, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID, &iodev, &score);
    if (err || !iodev)
    {
        printf("dealWithDevice: unable to create plugin. ret = %08x, iodev = %p\n", err, iodev);
        return;
    }
    err = (*iodev)->QueryInterface(iodev, 
                                   CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID), 
                                   (LPVOID*)&dev);
    (*iodev)->Release(iodev);               // done with this


    FOO_String string_value;
    UInt8 string_index = 0x1;
    FOO_Result result = FOO_SUCCESS;
    CFStringRef device_name_as_cf_string;
    do {
        if (FOO_SUCCEEDED(result = FOO_GetStringDescriptor(dev, string_index, 0, string_value))) {
            printf("String at index %i is %s\n", string_index, string_value.GetChars());
            // extract the command code if it is the FOO string
            if (string_value.CompareN("FOO:", 4) == 0) {
                FOO_Byte code = 0;
                FOO_HexToByte(string_value.GetChars() + 4, code);
                // Get other relevant information from the device
                io_name_t        device_name;
                UInt32           location_id = 0;

                // Get the USB device name.
                err = IORegistryEntryGetName(usb_device_ref, device_name);
                device_name_as_cf_string = CFStringCreateWithCString(kCFAllocatorDefault, device_name, 
                                                                     kCFStringEncodingASCII); 

                err = (*dev)->GetLocationID(dev, &location_id);

                // TODO: get volume or BSD name 

                // add the device to the list

                break;
            }
        }
        string_index++;
    } while (FOO_SUCCEEDED(result));


    err = (*dev)->USBDeviceClose(dev);
    if (err)
    {
        printf("dealWithDevice: error closing device - %08x\n", err);
        (*dev)->Release(dev);
        return;
    }
    err = (*dev)->Release(dev);
    if (err)
    {
        printf("dealWithDevice: error releasing device - %08x\n", err);
        return;
    }

    IOObjectRelease(usb_device_ref);            // no longer need this reference
}

Answer 1

io_service_t, IORegistry, BSD. .

#import <IOKit/IOBSD.h>

CFStringRef bsdName = ( CFStringRef ) IORegistryEntrySearchCFProperty ( usbDevice,
                                                                       kIOServicePlane,
                                                                       CFSTR ( kIOBSDNameKey ),
                                                                       kCFAllocatorDefault,
                                                                       kIORegistryIterateRecursively );

Answer 2

. :

usbdevs - USB- Mac OS X

https://gist.github.com/atr000/621561