Handling friends sysmodule logout via NDM

main.c

#include "3ds/result.h"
#include "3ds/services/ndm.h"
#include "3ds/svc.h"
#include <3ds/services/frd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <3ds.h>

int main(int argc, char* argv[])
{
	gfxInitDefault();
	consoleInit(GFX_TOP, NULL);

	frdInit(false);
	ndmuInit();

	Handle event = 0;

	Result res = NDMU_EnterExclusiveState(NDM_EXCLUSIVE_STATE_LOCAL_COMMUNICATIONS);
	printf("%08lX enter exclusive state\n", res);

	if (R_FAILED(svcCreateEvent(&event, RESET_ONESHOT)))
		svcBreak(0);

	res = FRD_SetNotificationMask(MASK_USER_WENT_OFFLINE);
	printf("%08lX set notification mask\n", res);

	res = FRD_AttachToEventNotification(event);
	printf("%08lX attach notification\n", res);

	bool exit = false;

	while (1) {
		if (exit) break;
		Result wres = svcWaitSynchronization(event, 5 * 1000000000LL);

		if (R_FAILED(wres))
			svcBreak(0);
		else if (R_SUCCEEDED(wres) && R_DESCRIPTION(wres) != RD_TIMEOUT) {
			NotificationEvent events[10] = { 0 };
			u32 numEvents = 0;
			res = FRD_GetEventNotification(events, 10, &numEvents);
			printf("%08lX got %ld notifs\n", res, numEvents);

			for (u32 i = 0; i < numEvents; i++) {
				printf("received: %d\n", events[i].type);
				if (events[i].type == USER_WENT_OFFLINE)
				{
					printf("successfully disconnected from friends services\n");
					exit = true;
					continue;
				}
			}
		}
		else {
			bool is_online = true;
			FRD_IsOnline(&is_online);
			if (is_online) {
				printf("system is still online, retrying\n");
				FRD_Logout(); // just in case
				continue;
			}

			printf("system is no longer online\n");
			printf("successfully disconnected from friends services\n");
			break;
		}
	}

	// Main loop
	while (aptMainLoop())
	{
		gspWaitForVBlank();
		gfxSwapBuffers();
		hidScanInput();

		// Your code goes here
		u32 kDown = hidKeysDown();
		if (kDown & KEY_START)
			break; // break in order to return to hbmenu
	}

	res = NDMU_LeaveExclusiveState();
	printf("%08lX leave exclusive state\n", res);

	svcCloseHandle(event);

	frdExit();
	ndmuExit();
	gfxExit();
	return 0;
}