macOS: fallback to parent entry kUSBInterfaceNumber prop

In macOS 13.3 the kUSBInterfaceNumber is no longer one of the properties
of the IOHIDDevice (even if its transport is USB).

In case if kUSBInterfaceNumber property (for USB Interface number)
is not available as an IOHIDDevice property - find the value for that property
in one of the Parent IORegistry Entries.

Author: Youw

mac/hid.c

@@ -329,6 +329,22 @@ static bool try_get_int_property(IOHIDDeviceRef device, CFStringRef key, int32_t
 	return result;
 }
 
+static bool try_get_ioregistry_int_property(io_service_t service, CFStringRef property, int32_t *out_val)
+{
+	bool result = false;
+	CFTypeRef ref = IORegistryEntryCreateCFProperty(service, property, kCFAllocatorDefault, 0);
+
+	if (ref) {
+		if (CFGetTypeID(ref) == CFNumberGetTypeID()) {
+			result = CFNumberGetValue(ref, kCFNumberSInt32Type, out_val);
+		}
+
+		CFRelease(ref);
+	}
+
+	return result;
+}
+
 static CFArrayRef get_usage_pairs(IOHIDDeviceRef device)
 {
 	return get_array_property(device, CFSTR(kIOHIDDeviceUsagePairsKey));
@@ -481,6 +497,46 @@ static void process_pending_events(void) {
 	} while(res != kCFRunLoopRunFinished && res != kCFRunLoopRunTimedOut);
 }
 
+static int read_usb_interface_from_hid_service_parent(io_service_t hid_service)
+{
+	int32_t result = -1;
+	bool success = false;
+	io_registry_entry_t current = IO_OBJECT_NULL;
+	kern_return_t res;
+	int parent_number = 0;
+
+	res = IORegistryEntryGetParentEntry(hid_service, kIOServicePlane, &current);
+	while (KERN_SUCCESS == res
+			/* Only search up to 3 parent entries.
+			 * With the default driver - the parent-of-interest supposed to be the first one,
+			 * but lets assume some custom drivers or so, with deeper tree. */
+			&& parent_number < 3) {
+		io_registry_entry_t parent = IO_OBJECT_NULL;
+		int32_t interface_number = -1;
+		parent_number++;
+
+		success = try_get_ioregistry_int_property(current, CFSTR(kUSBInterfaceNumber), &interface_number);
+		if (success) {
+			result = interface_number;
+			break;
+		}
+
+		res = IORegistryEntryGetParentEntry(current, kIOServicePlane, &parent);
+		if (parent) {
+			IOObjectRelease(current);
+			current = parent;
+		}
+
+	}
+
+	if (current) {
+		IOObjectRelease(current);
+		current = IO_OBJECT_NULL;
+	}
+
+	return result;
+}
+
 static struct hid_device_info *create_device_info_with_usage(IOHIDDeviceRef dev, int32_t usage_page, int32_t usage)
 {
 	unsigned short dev_vid;
@@ -490,7 +546,7 @@ static struct hid_device_info *create_device_info_with_usage(IOHIDDeviceRef dev,
 	CFTypeRef transport_prop;
 
 	struct hid_device_info *cur_dev;
-	io_object_t iokit_dev;
+	io_service_t hid_service;
 	kern_return_t res;
 	uint64_t entry_id = 0;
 
@@ -514,9 +570,9 @@ static struct hid_device_info *create_device_info_with_usage(IOHIDDeviceRef dev,
 
 	/* Fill in the path (as a unique ID of the service entry) */
 	cur_dev->path = NULL;
-	iokit_dev = IOHIDDeviceGetService(dev);
-	if (iokit_dev != MACH_PORT_NULL) {
-		res = IORegistryEntryGetRegistryEntryID(iokit_dev, &entry_id);
+	hid_service = IOHIDDeviceGetService(dev);
+	if (hid_service != MACH_PORT_NULL) {
+		res = IORegistryEntryGetRegistryEntryID(hid_service, &entry_id);
 	}
 	else {
 		res = KERN_INVALID_ARGUMENT;
@@ -567,11 +623,18 @@ static struct hid_device_info *create_device_info_with_usage(IOHIDDeviceRef dev,
 		if (CFStringCompare((CFStringRef)transport_prop, CFSTR(kIOHIDTransportUSBValue), 0) == kCFCompareEqualTo) {
 			int32_t interface_number = -1;
 			cur_dev->bus_type = HID_API_BUS_USB;
+
+			/* A IOHIDDeviceRef used to have this simple property,
+			 * until macOS 13.3 - we will try to use it. */
 			if (try_get_int_property(dev, CFSTR(kUSBInterfaceNumber), &interface_number)) {
 				cur_dev->interface_number = interface_number;
-			}
-			else {
-				// TODO: use a different approach - this is a USB device after all
+			} else {
+				/* Otherwise fallback to io_service_t property.
+				 * (of one of the parent services). */
+				cur_dev->interface_number = read_usb_interface_from_hid_service_parent(hid_service);
+
+				/* If the above doesn't work -
+				 * no (known) fallback exists at this point. */
 			}
 
 		/* Match "Bluetooth", "BluetoothLowEnergy" and "Bluetooth Low Energy" strings */