update: add LAN advertising configuration for server.properties

LAN-Discovery, which isn’t needed in server mode and could potentially be a security risk, has also been disabled(only server mode).

Minecraft.Client/Common/Network/PlatformNetworkManagerStub.cpp

@@ -379,9 +379,23 @@ void CPlatformNetworkManagerStub::HostGame(int localUsersMask, bool bOnlineGame,
 
 	if (WinsockNetLayer::IsActive())
 	{
-		const wchar_t* hostName = IQNet::m_player[0].m_gamertag;
+		// For Dedicated Server, refer to `lan-advertise` in `server.properties`
-		unsigned int settings = app.GetGameHostOption(eGameHostOption_All);
+		bool enableLanAdvertising = true;
-		WinsockNetLayer::StartAdvertising(port, hostName, settings, 0, 0, MINECRAFT_NET_VERSION);
+		if (g_Win64DedicatedServer)
+		{
+			enableLanAdvertising = g_Win64DedicatedServerLanAdvertise;
+		}
+
+		if (enableLanAdvertising)
+		{
+			const wchar_t* hostName = IQNet::m_player[0].m_gamertag;
+			unsigned int settings = app.GetGameHostOption(eGameHostOption_All);
+			WinsockNetLayer::StartAdvertising(port, hostName, settings, 0, 0, MINECRAFT_NET_VERSION);
+		}
+		else
+		{
+			WinsockNetLayer::StopAdvertising();
+		}
 	}
 #endif
 //#endif

Minecraft.Client/Windows64/Network/WinsockNetLayer.cpp

@@ -54,6 +54,7 @@ char g_Win64MultiplayerIP[256] = "127.0.0.1";
 bool g_Win64DedicatedServer = false;
 int g_Win64DedicatedServerPort = WIN64_NET_DEFAULT_PORT;
 char g_Win64DedicatedServerBindIP[256] = "";
+bool g_Win64DedicatedServerLanAdvertise = true;
 
 bool WinsockNetLayer::Initialize()
 {
@@ -76,7 +77,11 @@ bool WinsockNetLayer::Initialize()
 
 	s_initialized = true;
 
-	StartDiscovery();
+	// Dedicated Server does not use LAN session discovery and therefore does not initiate discovery.
+	if (!g_Win64DedicatedServer)
+	{
+		StartDiscovery();
+	}
 
 	return true;
 }

Minecraft.Client/Windows64/Network/WinsockNetLayer.h

@@ -150,5 +150,6 @@ extern char g_Win64MultiplayerIP[256];
 extern bool g_Win64DedicatedServer;
 extern int g_Win64DedicatedServerPort;
 extern char g_Win64DedicatedServerBindIP[256];
+extern bool g_Win64DedicatedServerLanAdvertise;
 
 #endif

Minecraft.Server/ServerProperties.cpp

@@ -26,6 +26,7 @@ static const int kDefaultServerPort = 25565;
 static const int kDefaultMaxPlayers = 8;
 static const int kMaxDedicatedPlayers = 8;
 static const int kDefaultAutosaveIntervalSeconds = 60;
+static const char *kLanAdvertisePropertyKey = "lan-advertise";
 
 static const ServerPropertyDefault kServerPropertyDefaults[] =
 {
@@ -63,6 +64,7 @@ static const ServerPropertyDefault kServerPropertyDefaults[] =
 	{ "server-ip", "0.0.0.0" },
 	{ "server-name", "DedicatedServer" },
 	{ "server-port", "25565" },
+	{ "lan-advertise", "false" },
 	{ "spawn-animals", "true" },
 	{ "spawn-monsters", "true" },
 	{ "spawn-npcs", "true" },
@@ -677,6 +679,7 @@ ServerPropertiesConfig LoadServerPropertiesConfig()
 
 	config.serverPort = ReadNormalizedIntProperty(&merged, "server-port", kDefaultServerPort, 1, 65535, &shouldWrite);
 	config.serverIp = ReadNormalizedStringProperty(&merged, "server-ip", "0.0.0.0", 255, &shouldWrite);
+	config.lanAdvertise = ReadNormalizedBoolProperty(&merged, kLanAdvertisePropertyKey, false, &shouldWrite);
 	config.serverName = ReadNormalizedStringProperty(&merged, "server-name", "DedicatedServer", 16, &shouldWrite);
 	config.maxPlayers = ReadNormalizedIntProperty(&merged, "max-players", kDefaultMaxPlayers, 1, kMaxDedicatedPlayers, &shouldWrite);
 	config.seed = 0;

Minecraft.Server/ServerProperties.h

@@ -19,6 +19,8 @@ namespace ServerRuntime
 		int serverPort;
 		/** `server-ip` */
 		std::string serverIp;
+		/** `lan-advertise` */
+		bool lanAdvertise;
 		/** `server-name` (max 16 chars at runtime) */
 		std::string serverName;
 		/** `max-players` */

Minecraft.Server/Windows64/ServerMain.cpp

@@ -328,6 +328,11 @@ int main(int argc, char **argv)
 	g_Win64MultiplayerJoin = false;
 	g_Win64MultiplayerPort = config.port;
 	strncpy_s(g_Win64MultiplayerIP, sizeof(g_Win64MultiplayerIP), config.bindIP, _TRUNCATE);
+	g_Win64DedicatedServer = true;
+	g_Win64DedicatedServerPort = config.port;
+	strncpy_s(g_Win64DedicatedServerBindIP, sizeof(g_Win64DedicatedServerBindIP), config.bindIP, _TRUNCATE);
+	g_Win64DedicatedServerLanAdvertise = serverProperties.lanAdvertise;
+	LogInfof("startup", "LAN advertise: %s", serverProperties.lanAdvertise ? "enabled" : "disabled");
 
 	LogStartupStep("registering hidden window class");
 	HINSTANCE hInstance = GetModuleHandle(NULL);