macos: improve USB interface number retrival

hidtest/test.c

@@ -52,6 +52,23 @@
 #endif
 //
 
+const char *hid_bus_name(hid_bus_type bus_type) {
+	static const char *const HidBusTypeName[] = {
+		"Unknown",
+		"USB",
+		"Bluetooth",
+		"I2C",
+		"SPI",
+	};
+
+	if ((int)bus_type < 0)
+		bus_type = HID_API_BUS_UNKNOWN;
+	if ((int)bus_type >= (int)(sizeof(HidBusTypeName) / sizeof(HidBusTypeName[0])))
+		bus_type = HID_API_BUS_UNKNOWN;
+
+	return HidBusTypeName[bus_type];
+}
+
 void print_device(struct hid_device_info *cur_dev) {
 	printf("Device Found\n  type: %04hx %04hx\n  path: %s\n  serial_number: %ls", cur_dev->vendor_id, cur_dev->product_id, cur_dev->path, cur_dev->serial_number);
 	printf("\n");
@@ -60,7 +77,7 @@ void print_device(struct hid_device_info *cur_dev) {
 	printf("  Release:      %hx\n", cur_dev->release_number);
 	printf("  Interface:    %d\n",  cur_dev->interface_number);
 	printf("  Usage (page): 0x%hx (0x%hx)\n", cur_dev->usage, cur_dev->usage_page);
-	printf("  Bus type: %d\n", cur_dev->bus_type);
+	printf("  Bus type: %d (%s)\n", cur_dev->bus_type, hid_bus_name(cur_dev->bus_type));
 	printf("\n");
 }
 

mac/hid.c

@@ -28,6 +28,7 @@
 #include <IOKit/usb/USBSpec.h>
 #include <CoreFoundation/CoreFoundation.h>
 #include <mach/mach_error.h>
+#include <stdbool.h>
 #include <wchar.h>
 #include <locale.h>
 #include <pthread.h>
@@ -302,7 +303,7 @@ static CFArrayRef get_array_property(IOHIDDeviceRef device, CFStringRef key)
 static int32_t get_int_property(IOHIDDeviceRef device, CFStringRef key)
 {
 	CFTypeRef ref;
-	int32_t value;
+	int32_t value = 0;
 
 	ref = IOHIDDeviceGetProperty(device, key);
 	if (ref) {
@@ -314,6 +315,36 @@ static int32_t get_int_property(IOHIDDeviceRef device, CFStringRef key)
 	return 0;
 }
 
+static bool try_get_int_property(IOHIDDeviceRef device, CFStringRef key, int32_t *out_val)
+{
+	bool result = false;
+	CFTypeRef ref;
+
+	ref = IOHIDDeviceGetProperty(device, key);
+	if (ref) {
+		if (CFGetTypeID(ref) == CFNumberGetTypeID()) {
+			result = CFNumberGetValue((CFNumberRef) ref, kCFNumberSInt32Type, out_val);
+		}
+	}
+	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));
@@ -466,6 +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;
@@ -475,7 +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;
 
@@ -499,9 +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;
@@ -540,24 +611,32 @@ static struct hid_device_info *create_device_info_with_usage(IOHIDDeviceRef dev,
 	/* Release Number */
 	cur_dev->release_number = get_int_property(dev, CFSTR(kIOHIDVersionNumberKey));
 
-	/* Interface Number */
-	/* We can only retrieve the interface number for USB HID devices.
-	 * IOKit always seems to return 0 when querying a standard USB device
-	 * for its interface. */
-	int is_usb_hid = get_int_property(dev, CFSTR(kUSBInterfaceClass)) == kUSBHIDClass;
-	if (is_usb_hid) {
-		/* Get the interface number */
-		cur_dev->interface_number = get_int_property(dev, CFSTR(kUSBInterfaceNumber));
-	} else {
-		cur_dev->interface_number = -1;
-	}
+	/* Interface Number.
+	 * We can only retrieve the interface number for USB HID devices.
+	 * See below */
+	cur_dev->interface_number = -1;
 
 	/* Bus Type */
 	transport_prop = IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDTransportKey));
 
 	if (transport_prop != NULL && CFGetTypeID(transport_prop) == CFStringGetTypeID()) {
 		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 {
+				/* 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 */
 		} else if (CFStringHasPrefix((CFStringRef)transport_prop, CFSTR(kIOHIDTransportBluetoothValue))) {
 			cur_dev->bus_type = HID_API_BUS_BLUETOOTH;