beep.cpp

#include <Windows.h>
#include <stdio.h>
#include <winternl.h>
#include <ntstatus.h>

#define BEEPDEV L"\\Device\\Beep"
#define IOCTLCODE 0x10000

typedef NTSTATUS(CALLBACK* NTOPENFILE)(PHANDLE, ACCESS_MASK, POBJECT_ATTRIBUTES, PIO_STATUS_BLOCK, ULONG, ULONG);

struct dd {
	unsigned int freq;
	unsigned int duration;
};

int main() {
	HANDLE h;
	IO_STATUS_BLOCK iosb;
	OBJECT_ATTRIBUTES oa;
	NTSTATUS status; 
	NTOPENFILE NtOpenFile;
	dd data;
	HMODULE hmod = LoadLibraryW(L"ntdll.dll");
	if (hmod == NULL) {
		printf("LoadLibraryW() failed\n");
		exit(0);
	}
	NtOpenFile = (NTOPENFILE)GetProcAddress(hmod, "NtOpenFile");
	if (NtOpenFile == NULL) {
		printf("GetProcAddress() failed\n");
		exit(0);
	}

	UNICODE_STRING BeepDevice = {sizeof(BEEPDEV) - sizeof(WCHAR),  sizeof(BEEPDEV), (PWSTR)BEEPDEV };
	InitializeObjectAttributes(&oa, &BeepDevice, 0, NULL, NULL);

	status = NtOpenFile(&h, GENERIC_READ, &oa, &iosb, 0, 0);
	if (status != STATUS_SUCCESS) {
		printf("NtOpenFile() failed\n");
		exit(0);
	}

	data.duration = 1000;
	data.freq = 1100000;
	DWORD bytes = 0;
	BOOL r = DeviceIoControl(h, IOCTLCODE, &data, sizeof(data), NULL, 0, &bytes, NULL);
	printf("r: %u\n", r);

	Sleep(2000);
	printf("done\n");
}