main function for interacting with accessory protocol

main.cpp

//
//  main.cpp
//  AccessoryMode
//
//  Created by David Weinstein on 07/30/2012.
//  Copyright (c) 2012 David Weinstein. All rights reserved.
//  Code based on documentation from apple: Working With USB Device Interfaces
//  see https://developer.apple.com/library/mac/documentation/DeviceDrivers/Conceptual/USBBook/index.html
//
//  *Important* If your application is sandboxed, it must request the 
//  com.apple.security.device.usb entitlement in order to access USB devices.
//  


#include <CoreFoundation/CoreFoundation.h>

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

#include "accessory.h"

#define DBGPRINT printf("DEBUG: \"%s\", line %d: ", __FILE__,__LINE__),printf

//
// vendor / product identifiers for target device
// can grab these from e.g., USB Prober.app
// the following is for the Samsung Galaxy Nexus Android device
//
#define kGoogleVendorID          0x18D1
#define kAccessoryProductID      0x2D00
#define kAccessoryADBProductID   0x2D01
//#define kAccessoryADBProductID   0x2D00

#define kNexusVendorID           0x04E8
#define kNexusProductID          0x6860
//#define kNexusProductID          0x685C

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

int main(int argc, const char *argv[])
{
    CFMutableDictionaryRef  matchingDict, matchingDict2;
    CFRunLoopSourceRef      runLoopSource;
    CFNumberRef             numberRef;
    kern_return_t           kr;
    long                    usbVendor  = kNexusVendorID;
    long                    usbProduct = kNexusProductID;
    long                    googleUSBVendor = kGoogleVendorID;
    long                    googleUSBProduct = kAccessoryADBProductID;
    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.    
    matchingDict = IOServiceMatching(kIOUSBDeviceClassName);
    if (matchingDict == NULL) {
        fprintf(stderr, "IOServiceMatching returned NULL.\n");
        return -1;
    }
    
    matchingDict2 = IOServiceMatching(kIOUSBDeviceClassName);
    if (matchingDict2 == NULL) {
        fprintf(stderr, "IOServiceMatching returned NULL.\n");
        return -1;
    }
    
    // We are interested in USB devices (as opposed to USB interfaces).      
    // 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 CFNumber for the accessory mode vendor and product IDs
    numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &googleUSBVendor);
    CFDictionarySetValue(matchingDict2, 
                         CFSTR(kUSBVendorID), 
                         numberRef);
    CFRelease(numberRef);
    numberRef = NULL;
    
    numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &googleUSBProduct);
    CFDictionarySetValue(matchingDict2, 
                         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);
  
    if (1) {
        // 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); 
    }
    
    if (1) {
        // Now set up a notification to be called when a device is first matched by I/O Kit.
        kr = IOServiceAddMatchingNotification(gNotifyPort,                  // notifyPort
                                              kIOFirstMatchNotification,    // notificationType
                                              matchingDict2,                // matching
                                              AccessoryModeDeviceAdded,     // callback
                                              NULL,                         // refCon
                                              &gAddedIter                   // notification
                                              );
        // Iterate once to get already-present devices and arm the notification        
        AccessoryModeDeviceAdded(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;
}