Add network capabilities to handle same server version changes

src/network/network_config.cpp

@@ -67,6 +67,7 @@ NetworkConfig::NetworkConfig()
  */
 void NetworkConfig::unsetNetworking()
 {
+    clearServerCapabilities();
     m_network_type = NETWORK_NONE;
     ServerConfig::m_private_server_password = "";
 }   // unsetNetworking

src/network/network_config.hpp

@@ -93,6 +93,10 @@ private:
     /** Set by client or server which is required to be the same. */
     int m_state_frequency;
 
+    /** List of server capabilities set when joining it, to determine features
+     *  available in same version. */
+    std::vector<std::string> m_server_capabilities;
+
 public:
     /** Singleton get, which creates this object if necessary. */
     static NetworkConfig *get()
@@ -231,6 +235,15 @@ public:
     int getStateFrequency() const                 { return m_state_frequency; }
     // ------------------------------------------------------------------------
     bool roundValuesNow() const;
+    // ------------------------------------------------------------------------
+    void setServerCapabilities(std::vector<std::string>& caps)
+                                   { m_server_capabilities = std::move(caps); }
+    // ------------------------------------------------------------------------
+    void clearServerCapabilities()           { m_server_capabilities.clear(); }
+    // ------------------------------------------------------------------------
+    const std::vector<std::string>& getServerCapabilities() const
+                                              { return m_server_capabilities; }
+
 };   // class NetworkConfig
 
 #endif // HEADER_NETWORK_CONFIG

src/network/protocols/client_lobby.cpp

@@ -332,10 +332,13 @@ void ClientLobby::update(int ticks)
         break;
     case LINKED:
     {
+        NetworkConfig::get()->clearServerCapabilities();
         NetworkString* ns = getNetworkString();
         ns->addUInt8(LE_CONNECTION_REQUESTED)
             .addUInt32(ServerConfig::m_server_version)
-            .encodeString(StringUtils::getUserAgentString());
+            .encodeString(StringUtils::getUserAgentString())
+            // Reserved for future to supply list of network capabilities
+            .addUInt16(0);
 
         auto all_k = kart_properties_manager->getAllAvailableKarts();
         auto all_t = track_manager->getAllTrackIdentifiers();
@@ -578,6 +581,17 @@ void ClientLobby::connectionAccepted(Event* event)
     assert(server_version != 0);
     m_auto_started = false;
     m_state.store(CONNECTED);
+
+    unsigned list_caps = data.getUInt16();
+    std::vector<std::string> caps;
+    for (unsigned i = 0; i < list_caps; i++)
+    {
+        std::string cap;
+        data.decodeString(&cap);
+        caps.push_back(cap);
+    }
+    NetworkConfig::get()->setServerCapabilities(caps);
+
     float auto_start_timer = data.getFloat();
     int state_frequency_in_server = data.getUInt32();
     NetworkConfig::get()->setStateFrequency(state_frequency_in_server);

src/network/protocols/server_lobby.cpp

@@ -2011,6 +2011,16 @@ void ServerLobby::connectionRequested(Event* event)
     data.decodeString(&user_version);
     event->getPeer()->setUserVersion(user_version);
 
+    unsigned list_caps = data.getUInt16();
+    std::vector<std::string> caps;
+    for (unsigned i = 0; i < list_caps; i++)
+    {
+        std::string cap;
+        data.decodeString(&cap);
+        caps.push_back(cap);
+    }
+    event->getPeer()->setClientCapabilities(caps);
+
     std::set<std::string> client_karts, client_tracks;
     const unsigned kart_num = data.getUInt16();
     const unsigned track_num = data.getUInt16();
@@ -2267,7 +2277,12 @@ void ServerLobby::handleUnencryptedConnection(std::shared_ptr<STKPeer> peer,
             (m_timeout.load() - (int64_t)StkTime::getRealTimeMs()) / 1000.0f;
     }
     message_ack->addUInt8(LE_CONNECTION_ACCEPTED).addUInt32(peer->getHostId())
-        .addUInt32(ServerConfig::m_server_version).addFloat(auto_start_timer)
+        .addUInt32(ServerConfig::m_server_version);
+
+    // Reserved for future to supply list of network capabilities
+    message_ack->addUInt16(0);
+
+    message_ack->addFloat(auto_start_timer)
         .addUInt32(ServerConfig::m_state_frequency);
 
     peer->setSpectator(false);

src/network/stk_peer.hpp

@@ -100,6 +100,10 @@ protected:
 
     std::string m_user_version;
 
+    /** List of client capabilities set when connecting it, to determine
+     *  features available in same version. */
+    std::vector<std::string> m_client_capabilities;
+
 public:
     STKPeer(ENetPeer *enet_peer, STKHost* host, uint32_t host_id);
     // ------------------------------------------------------------------------
@@ -231,6 +235,12 @@ public:
             return 0;
         return (int)(diff / 1000);
     }
+    // ------------------------------------------------------------------------
+    void setClientCapabilities(std::vector<std::string>& caps)
+                                   { m_client_capabilities = std::move(caps); }
+    // ------------------------------------------------------------------------
+    const std::vector<std::string>& getClientCapabilities() const
+                                              { return m_client_capabilities; }
 };   // STKPeer
 
 #endif // STK_PEER_HPP