/*
    File:			USBPrivateDataSample.c
	
    Description:	This sample demonstrates how to use IOKitLib and IOUSBLib to set up asynchronous
					callbacks when a USB device is attached to or removed from the system.
					It also shows how to associate arbitrary data with each device instance.
                
    Copyright:		� Copyright 2001-2006 Apple Computer, Inc. All rights reserved.
	
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	Change History (most recent first):
        
            1.2	 	10/04/2006			Updated to produce a universal binary. Now requires Xcode 2.2.1 or
										later to build. Modernized and incorporated bug fixes.

			1.1		04/24/2002			Added comments, release of interface object, use of USB location ID
            
			1.0	 	10/30/2001			New sample.
        
*/

#include <CoreFoundation/CoreFoundation.h>

#include <IOKit/IOKitLib.h>
#include <IOKit/IOMessage.h>
#include <IOKit/IOCFPlugIn.h>
#include <IOKit/usb/IOUSBLib.h>

// Change these two constants to match your device's idVendor and idProduct.
// Or, just pass your idVendor and idProduct as command line arguments when running this sample.
#define kMyVendorID			1351
#define kMyProductID		8193

typedef struct MyPrivateData {
    io_object_t				notification;
    IOUSBDeviceInterface	**deviceInterface;
    CFStringRef				deviceName;
    UInt32					locationID;
} MyPrivateData;

static IONotificationPortRef	gNotifyPort;
static io_iterator_t			gAddedIter;
static CFRunLoopRef				gRunLoop;

//================================================================================================
//
//	DeviceNotification
//
//	This routine will get called whenever any kIOGeneralInterest notification happens.  We are
//	interested in the kIOMessageServiceIsTerminated message so that's what we look for.  Other
//	messages are defined in IOMessage.h.
//
//================================================================================================
void DeviceNotification(void *refCon, io_service_t service, natural_t messageType, void *messageArgument)
{
    kern_return_t	kr;
    MyPrivateData	*privateDataRef = (MyPrivateData *) refCon;
    
    if (messageType == kIOMessageServiceIsTerminated) {
        fprintf(stderr, "Device removed.\n");
    
        // Dump our private data to stderr just to see what it looks like.
        fprintf(stderr, "privateDataRef->deviceName: ");
		CFShow(privateDataRef->deviceName);
		fprintf(stderr, "privateDataRef->locationID: 0x%lx.\n\n", privateDataRef->locationID);
    
        // Free the data we're no longer using now that the device is going away
        CFRelease(privateDataRef->deviceName);
        
        if (privateDataRef->deviceInterface) {
            kr = (*privateDataRef->deviceInterface)->Release(privateDataRef->deviceInterface);
        }
        
        kr = IOObjectRelease(privateDataRef->notification);
        
        free(privateDataRef);
    }
}

//================================================================================================
//
//	DeviceAdded
//
//	This routine is the callback for our IOServiceAddMatchingNotification.  When we get called
//	we will look at all the devices that were added and we will:
//
//	1.  Create some private data to relate to each device (in this case we use the service's name
//	    and the location ID of the device
//	2.  Submit an IOServiceAddInterestNotification of type kIOGeneralInterest for this device,
//	    using the refCon field to store a pointer to our private data.  When we get called with
//	    this interest notification, we can grab the refCon and access our private data.
//
//================================================================================================
void DeviceAdded(void *refCon, io_iterator_t iterator)
{
    kern_return_t		kr;
    io_service_t		usbDevice;
    IOCFPlugInInterface	**plugInInterface = NULL;
    SInt32				score;
    HRESULT 			res;
    
    while ((usbDevice = IOIteratorNext(iterator))) {
        io_name_t		deviceName;
        CFStringRef		deviceNameAsCFString;	
        MyPrivateData	*privateDataRef = NULL;
        UInt32			locationID;
        
        printf("Device added.\n");
        
        // Add some app-specific information about this device.
        // Create a buffer to hold the data.
        privateDataRef = malloc(sizeof(MyPrivateData));
        bzero(privateDataRef, sizeof(MyPrivateData));
        
        // Get the USB device's name.
        kr = IORegistryEntryGetName(usbDevice, deviceName);
		if (KERN_SUCCESS != kr) {
            deviceName[0] = '\0';
        }
        
        deviceNameAsCFString = CFStringCreateWithCString(kCFAllocatorDefault, deviceName, 
                                                         kCFStringEncodingASCII);
        
        // Dump our data to stderr just to see what it looks like.
        fprintf(stderr, "deviceName: ");
        CFShow(deviceNameAsCFString);
        
        // Save the device's name to our private data.        
        privateDataRef->deviceName = deviceNameAsCFString;
                                                
        // Now, get the locationID of this device. In order to do this, we need to create an IOUSBDeviceInterface 
        // for our device. This will create the necessary connections between our userland application and the 
        // kernel object for the USB Device.
        kr = IOCreatePlugInInterfaceForService(usbDevice, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID,
                                               &plugInInterface, &score);

        if ((kIOReturnSuccess != kr) || !plugInInterface) {
            fprintf(stderr, "IOCreatePlugInInterfaceForService returned 0x%08x.\n", kr);
            continue;
        }

        // Use the plugin interface to retrieve the device interface.
        res = (*plugInInterface)->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID),
                                                 (LPVOID*) &privateDataRef->deviceInterface);
        
        // Now done with the plugin interface.
        (*plugInInterface)->Release(plugInInterface);
        			
        if (res || privateDataRef->deviceInterface == NULL) {
            fprintf(stderr, "QueryInterface returned %d.\n", (int) res);
            continue;
        }

        // Now that we have the IOUSBDeviceInterface, we can call the routines in IOUSBLib.h.
        // In this case, fetch the locationID. The locationID uniquely identifies the device
        // and will remain the same, even across reboots, so long as the bus topology doesn't change.
        
        kr = (*privateDataRef->deviceInterface)->GetLocationID(privateDataRef->deviceInterface, &locationID);
        if (KERN_SUCCESS != kr) {
            fprintf(stderr, "GetLocationID returned 0x%08x.\n", kr);
            continue;
        }
        else {
            fprintf(stderr, "Location ID: 0x%lx\n\n", locationID);
        }

        privateDataRef->locationID = locationID;
        
        // Register for an interest notification of this device being removed. Use a reference to our
        // private data as the refCon which will be passed to the notification callback.
        kr = IOServiceAddInterestNotification(gNotifyPort,						// notifyPort
											  usbDevice,						// service
											  kIOGeneralInterest,				// interestType
											  DeviceNotification,				// callback
											  privateDataRef,					// refCon
											  &(privateDataRef->notification)	// notification
											  );
                                                
        if (KERN_SUCCESS != kr) {
            printf("IOServiceAddInterestNotification returned 0x%08x.\n", kr);
        }
        
        // Done with this USB device; release the reference added by IOIteratorNext
        kr = IOObjectRelease(usbDevice);
    }
}

//================================================================================================
//
//	SignalHandler
//
//	This routine will get called when we interrupt the program (usually with a Ctrl-C from the
//	command line).
//
//================================================================================================
void SignalHandler(int sigraised)
{
    fprintf(stderr, "\nInterrupted.\n");
   
    exit(0);
}

//================================================================================================
//	main
//================================================================================================
int main(int argc, const char *argv[])
{
    CFMutableDictionaryRef 	matchingDict;
    CFRunLoopSourceRef		runLoopSource;
    CFNumberRef				numberRef;
    kern_return_t			kr;
    long					usbVendor = kMyVendorID;
    long					usbProduct = kMyProductID;
    sig_t					oldHandler;
    
    // pick up command line arguments
    if (argc > 1) {
        usbVendor = atoi(argv[1]);
	}
    if (argc > 2) {
        usbProduct = atoi(argv[2]);
	}

    // Set up a signal handler so we can clean up when we're interrupted from the command line
    // Otherwise we stay in our run loop forever.
    oldHandler = signal(SIGINT, SignalHandler);
    if (oldHandler == SIG_ERR) {
        fprintf(stderr, "Could not establish new signal handler.");
	}
        
    fprintf(stderr, "Looking for devices matching vendor ID=%ld and product ID=%ld.\n", usbVendor, usbProduct);

    // Set up the matching criteria for the devices we're interested in. The matching criteria needs to follow
    // the same rules as kernel drivers: mainly it needs to follow the USB Common Class Specification, pp. 6-7.
    // See also Technical Q&A QA1076 "Tips on USB driver matching on Mac OS X" 
	// <http://developer.apple.com/qa/qa2001/qa1076.html>.
    // One exception is that you can use the matching dictionary "as is", i.e. without adding any matching 
    // criteria to it and it will match every IOUSBDevice in the system. IOServiceAddMatchingNotification will 
    // consume this dictionary reference, so there is no need to release it later on.
    
    matchingDict = IOServiceMatching(kIOUSBDeviceClassName);	// Interested in instances of class
                                                                // IOUSBDevice and its subclasses
    if (matchingDict == NULL) {
        fprintf(stderr, "IOServiceMatching returned NULL.\n");
        return -1;
    }
    
    // We are interested in all USB devices (as opposed to USB interfaces).  The Common Class Specification
    // tells us that we need to specify the idVendor, idProduct, and bcdDevice fields, or, if we're not interested
    // in particular bcdDevices, just the idVendor and idProduct.  Note that if we were trying to match an 
    // IOUSBInterface, we would need to set more values in the matching dictionary (e.g. idVendor, idProduct, 
    // bInterfaceNumber and bConfigurationValue.
    
    // Create a CFNumber for the idVendor and set the value in the dictionary
    numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &usbVendor);
    CFDictionarySetValue(matchingDict, 
                         CFSTR(kUSBVendorID), 
                         numberRef);
    CFRelease(numberRef);
    
    // Create a CFNumber for the idProduct and set the value in the dictionary
    numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &usbProduct);
    CFDictionarySetValue(matchingDict, 
                         CFSTR(kUSBProductID), 
                         numberRef);
    CFRelease(numberRef);
    numberRef = NULL;

    // Create a notification port and add its run loop event source to our run loop
    // This is how async notifications get set up.
    
    gNotifyPort = IONotificationPortCreate(kIOMasterPortDefault);
    runLoopSource = IONotificationPortGetRunLoopSource(gNotifyPort);
    
    gRunLoop = CFRunLoopGetCurrent();
    CFRunLoopAddSource(gRunLoop, runLoopSource, kCFRunLoopDefaultMode);
    
    // Now set up a notification to be called when a device is first matched by I/O Kit.
    kr = IOServiceAddMatchingNotification(gNotifyPort,					// notifyPort
                                          kIOFirstMatchNotification,	// notificationType
                                          matchingDict,					// matching
                                          DeviceAdded,					// callback
                                          NULL,							// refCon
                                          &gAddedIter					// notification
                                          );		
                                            
    // Iterate once to get already-present devices and arm the notification    
    DeviceAdded(NULL, gAddedIter);	

    // Start the run loop. Now we'll receive notifications.
    fprintf(stderr, "Starting run loop.\n\n");
    CFRunLoopRun();
        
    // We should never get here
    fprintf(stderr, "Unexpectedly back from CFRunLoopRun()!\n");
    return 0;
}