DNS-SD service registration for Windows 10 to show Apple device icons on macOS

dnssd.cpp

#include <stdio.h>
#include <windows.h>
#include <windns.h>

#pragma comment(lib, "dnsapi.lib")
#pragma comment(lib, "ws2_32.lib")

static void Done(DWORD, PVOID, PDNS_SERVICE_INSTANCE)
{

}

int WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR lpCmdLine, _In_ int nShowCmd)
{
	int argc = 0;
	wchar_t** argv = CommandLineToArgvW(GetCommandLineW(), &argc);

	const wchar_t* model = L"MacPro7,1";
	const wchar_t* color = L"";

	if (argc >= 2)
	{
		model = argv[1];
	}

	if (argc >= 3)
	{
		color = argv[2];
	}

	int keyCount = (color && color[0]) ? 2 : 1;

	const wchar_t* keys[] = { L"model", L"ecolor" };
	const wchar_t* values[] = { model, color };

	wchar_t computername[512];
	DWORD nameLen = _countof(computername);
	GetComputerNameW(computername, &nameLen);

	auto reg = [&](const wchar_t* host, int port, bool mac)
	{
		wchar_t hostBuf[256];
		swprintf_s(hostBuf, L"%s%s", computername, host);

		auto instance = DnsServiceConstructInstance(
			hostBuf,
			computername,
			NULL,
			NULL,
			port,
			0,
			0,
			mac ? keyCount : 0,
			mac ? keys : nullptr,
			mac ? values : nullptr);

		DNS_SERVICE_REGISTER_REQUEST regReq = { 0 };
		regReq.Version = DNS_QUERY_REQUEST_VERSION1;
		regReq.InterfaceIndex = 0;
		regReq.pServiceInstance = instance;
		regReq.unicastEnabled = FALSE;
		regReq.pRegisterCompletionCallback = Done;

		DnsServiceRegister(&regReq, NULL);
	};

	reg(L"._device-info._tcp.local", 696, true);
	reg(L"._smb._tcp.local", 445, false);

	WaitForSingleObject(GetCurrentProcess(), INFINITE);

	return 0;
}