Add ipv6 server configuration

NETWORKING.md

@@ -78,6 +78,9 @@ The current server configuration xml looks like this:
     <!-- Disable it to turn off all stun related code in server, it allows saving server resource if your server is not behind a firewall. -->
     <firewalled-server value="true" />
 
+    <!-- Enable to allow ipv6 connection if you have a public ipv6 address. STK currently use dual-stack mode which requires server to have both ipv4 and ipv6 and listen to same port, firewalled-server will be disabled so you need to make sure this server has port forward configured properly if needed. -->
+    <ipv6-server value="false" />
+
     <!-- No server owner in lobby which can control the starting of game or kick any players. -->
     <owner-less value="false" />
 

src/network/server_config.cpp

@@ -340,6 +340,15 @@ void loadServerLobbyFromConfig()
         m_server_max_players > 10)
         m_server_max_players = 10;
 
+    if (m_ipv6_server)
+    {
+#ifdef ENABLE_IPV6
+        m_firewalled_server = false;
+#else
+        Log::warn("ServerConfig", "IPV6 support not compiled.");
+#endif
+    }
+
     if (m_ranked)
     {
         m_validating_player = true;

src/network/server_config.hpp

@@ -176,6 +176,14 @@ namespace ServerConfig
         "it allows saving server resource if your server is not "
         "behind a firewall."));
 
+    SERVER_CFG_PREFIX BoolServerConfigParam m_ipv6_server
+        SERVER_CFG_DEFAULT(BoolServerConfigParam(false, "ipv6-server",
+        "Enable to allow ipv6 connection if you have a public ipv6 address. "
+        "STK currently use dual-stack mode which requires server to have both "
+        "ipv4 and ipv6 and listen to same port, firewalled-server will be "
+        "disabled so you need to make sure this server has port forward "
+        "configured properly if needed."));
+
     SERVER_CFG_PREFIX BoolServerConfigParam m_owner_less
         SERVER_CFG_DEFAULT(BoolServerConfigParam(false, "owner-less",
         "No server owner in lobby which can control the starting of game or "

src/network/stk_host.cpp

@@ -261,6 +261,7 @@ STKHost::STKHost(bool server)
 
     if (server)
     {
+        setIPV6(ServerConfig::m_ipv6_server ? 1 : 0);
         addr.port = ServerConfig::m_server_port;
         if (addr.port == 0 && !UserConfigParams::m_random_server_port)
             addr.port = stk_config->m_server_port;
@@ -856,12 +857,18 @@ void STKHost::mainLoop()
 
     // A separate network connection (socket) to handle LAN requests.
     Network* direct_socket = NULL;
-    if (!isIPV6() && ((NetworkConfig::get()->isLAN() && is_server) ||
-        NetworkConfig::get()->isPublicServer()))
+    if ((NetworkConfig::get()->isLAN() && is_server) ||
+        NetworkConfig::get()->isPublicServer())
     {
         TransportAddress address(0, stk_config->m_server_discovery_port);
         ENetAddress eaddr = address.toEnetAddress();
+        bool socket_ipv6 = isIPV6() == 1 ? true : false;
+        if (socket_ipv6)
+            setIPV6(0);
+        // direct_socket use IPV4 only atm
         direct_socket = new Network(1, 1, 0, 0, &eaddr);
+        if (socket_ipv6)
+            setIPV6(1);
         if (direct_socket->getENetHost() == NULL)
         {
             Log::warn("STKHost", "No direct socket available, this "

src/network/unix_ipv6.cpp

@@ -141,6 +141,11 @@ int isIPV6()
     return 0;
 }   // isIPV6
 
+// ----------------------------------------------------------------------------
+void setIPV6(int val)
+{
+}   // setIPV6
+
 // ----------------------------------------------------------------------------
 std::string getIPV6ReadableFromMappedAddress(const ENetAddress* ea)
 {
@@ -180,7 +185,7 @@ void unixInitialize()
 {
     // Clear previous setting, in case user changed wifi or mobile data
     g_mapped_ipv6_used = 0;
-    g_ipv6 = 1;
+    g_ipv6 = 0;
     g_mapped_ips.clear();
 }   // unixInitialize