darling-xnu/tests/iokit/service_helpers.c

#include <sys/sysctl.h>
#include <IOKit/IOKitLib.h>
#include <errno.h>
#include <stdio.h>

#include "service_helpers.h"

#define MAX_RETRIES 10

/*
 * Helper method to find IOServices needed for testing. Use with T_ASSERT_POSIX_SUCCESS(...)
 */
int
IOTestServiceFindService(const char * name, io_service_t * serviceOut)
{
	int err = 0;
	int retries = 0;
	io_service_t service = IO_OBJECT_NULL;

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcast-qual"
	err = sysctlbyname("kern.iokit_test_service_setup", NULL, 0, (void *)name, strlen(name));
#pragma clang diagnostic pop
	if (err) {
		goto finish;
	}

	do {
		service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching(name));
		if (service == IO_OBJECT_NULL) {
			sleep(1);
			retries += 1;
		}
	} while (service == IO_OBJECT_NULL && retries <= MAX_RETRIES);

	if (service == IO_OBJECT_NULL) {
		err = ENOENT;
		goto finish;
	}

	err = 0;

finish:
	if (serviceOut && service != IO_OBJECT_NULL) {
		*serviceOut = service;
	} else if (service != IO_OBJECT_NULL) {
		IOObjectRelease(service);
	}

	return err;
}