Allow pre-set IP type in config.xml

src/config/user_config.hpp

@@ -825,6 +825,10 @@ namespace UserConfigParams
      PARAM_PREFIX IntUserConfigParam m_timer_sync_difference_tolerance
         PARAM_DEFAULT(IntUserConfigParam(5, "timer-sync-difference-tolerance",
         &m_network_group, "Max time difference tolerance (in ms) to synchronize timer with server."));
+    PARAM_PREFIX IntUserConfigParam m_default_ip_type
+        PARAM_DEFAULT(IntUserConfigParam(0, "default-ip-type",
+        &m_network_group, "Default IP type of this machine, "
+        "0 detect every time, 1 IPv4, 2 IPv6, 3 IPv6 NAT64, 4 Dual stack."));
 
     // ---- Gamemode setup
     PARAM_PREFIX UIntToUIntUserConfigParam m_num_karts_per_gamemode

src/network/network_config.cpp

@@ -200,6 +200,12 @@ bool NetworkConfig::roundValuesNow() const
 void NetworkConfig::detectIPType()
 {
     m_nat64_prefix_data.fill(-1);
+    if (UserConfigParams::m_default_ip_type != IP_NONE)
+    {
+        int ip_type = UserConfigParams::m_default_ip_type;
+        m_ip_type.store((IPType)ip_type);
+        return;
+    }
 #ifdef ENABLE_IPV6
     ENetAddress eaddr;
     eaddr.host = STKHost::HOST_ANY;

src/network/network_config.hpp

@@ -49,7 +49,7 @@ class PlayerProfile;
 class NetworkConfig : public NoCopy
 {
 public:
-    enum IPType : uint8_t
+    enum IPType : int
     {
         IP_NONE, IP_V4, IP_V6, IP_V6_NAT64, IP_DUAL_STACK
     };