Make sure the correct socket type is used

src/network/network.cpp

@@ -63,6 +63,7 @@ Network::Network(int peer_count, int channel_limit,
                  uint32_t max_outgoing_bandwidth,
                  ENetAddress* address, bool change_port_if_bound)
 {
+    m_ipv6_socket = false;
     m_port = 0;
     m_host = enet_host_create(address, peer_count, channel_limit, 0, 0);
     if (!m_host && change_port_if_bound)
@@ -77,29 +78,30 @@ Network::Network(int peer_count, int channel_limit,
         if (!m_host)
             Log::fatal("Network", "Failed to create socket with any port.");
     }
-    if (m_host && isIPv6Socket())
+    if (m_host)
     {
-        struct sockaddr_in6 sin6;
+        struct sockaddr_storage ss;
-        socklen_t len = sizeof(sin6);
+        memset(&ss, 0, sizeof (struct sockaddr_storage));
-        if (getsockname(m_host->socket, (struct sockaddr*)&sin6, &len) == -1)
+        socklen_t len = sizeof(ss);
+        if (getsockname(m_host->socket, (struct sockaddr*)&ss, &len) == -1)
         {
             Log::error("STKHost", "Error while using getsockname().");
             m_port = 0;
         }
         else
-            m_port = ntohs(sin6.sin6_port);
-    }
-    else if (m_host)
-    {
-        struct sockaddr_in sin;
-        socklen_t len = sizeof(sin);
-        if (getsockname(m_host->socket, (struct sockaddr*)&sin, &len) == -1)
         {
-            Log::error("STKHost", "Error while using getsockname().");
+            m_ipv6_socket = ss.ss_family == AF_INET6;
-            m_port = 0;
+            if (m_ipv6_socket)
+            {
+                sockaddr_in6* sin6 = (sockaddr_in6*)&ss;
+                m_port = ntohs(sin6->sin6_port);
+            }
+            else
+            {
+                sockaddr_in* sin = (sockaddr_in*)&ss;
+                m_port = ntohs(sin->sin_port);
+            }
         }
-        else
-            m_port = ntohs(sin.sin_port);
     }
 }   // Network
 

src/network/network.hpp

@@ -50,6 +50,7 @@ private:
 
     uint16_t m_port;
 
+    bool m_ipv6_socket;
     /** Where to log packets. If NULL for FILE* logging is disabled. */
     static Synchronised<FILE*> m_log_file;
 
@@ -77,6 +78,8 @@ public:
     // ------------------------------------------------------------------------
     /** Returns a pointer to the ENet host object. */
     ENetHost* getENetHost() { return m_host; }
+    // ------------------------------------------------------------------------
+    bool isIPv6Socket() { return m_ipv6_socket; }
 };   // class Network
 
 #endif // HEADER_ENET_SOCKET_HPP

src/network/protocols/connect_to_server.cpp

@@ -231,12 +231,13 @@ void ConnectToServer::asynchronousUpdate()
 
             // Auto enable IPv6 socket in client with NAT64, then we convert
             // the IPv4 address to NAT64 one in GOT_SERVER_ADDRESS
-            if (m_server->useIPV6Connection() ||
+            bool ipv6_socket = m_server->useIPV6Connection() ||
-                NetworkConfig::get()->getIPType() == NetworkConfig::IP_V6_NAT64)
+                NetworkConfig::get()->getIPType() == NetworkConfig::IP_V6_NAT64;
+            if (STKHost::get()->getNetwork()->isIPv6Socket() != ipv6_socket)
             {
                 // Free the bound socket first
                 delete STKHost::get()->getNetwork();
-                setIPv6Socket(1);
+                setIPv6Socket(ipv6_socket ? 1 : 0);
                 ENetAddress addr = {};
                 addr.port = NetworkConfig::get()->getClientPort();
                 auto new_network = new Network(/*peer_count*/1,