feat: Enhance EtsDeviceRuntime constructor and multicast handling

- Updated EtsDeviceRuntime constructor to accept an optional tunnel_client_address parameter with a default value of 0.
- Modified EspIdfPlatform::setupMultiCast to use IPPROTO_UDP for socket creation and improved multicast interface selection based on the current IP address.
- Ensured that the multicast interface is set only if a valid local address is available.
- Adjusted the client address assignment in EtsDeviceRuntime to use the provided tunnel_client_address if valid, falling back to the default otherwise.

Signed-off-by: Tony <tonylu@tony-cloud.com>

components/gateway_knx/include/gateway_knx.hpp

@@ -63,7 +63,8 @@ struct GatewayKnxConfig {
   uint8_t main_group{0};
   uint16_t udp_port{kGatewayKnxDefaultUdpPort};
   std::string multicast_address{kGatewayKnxDefaultMulticastAddress};
-  uint16_t individual_address{0x1101};
+  uint16_t ip_interface_individual_address{0xff01};
+  uint16_t individual_address{0xfffe};
   int programming_button_gpio{-1};
   bool programming_button_active_low{true};
   int programming_led_gpio{-1};
@@ -208,6 +209,9 @@ class GatewayKnxTpIpRouter {
   void setGroupWriteHandler(GroupWriteHandler handler);
   const GatewayKnxConfig& config() const;
   bool tpUartOnline() const;
+  bool programmingMode();
+  esp_err_t setProgrammingMode(bool enabled);
+  esp_err_t toggleProgrammingMode();
 
   esp_err_t start(uint32_t task_stack_size, UBaseType_t task_priority);
   esp_err_t stop();
@@ -217,6 +221,14 @@ class GatewayKnxTpIpRouter {
 
  private:
   static constexpr size_t kMaxTunnelClients = 16;
+  static constexpr size_t kMaxTcpClients = 4;
+
+  struct TcpClient {
+    int sock{-1};
+    ::sockaddr_in remote{};
+    std::vector<uint8_t> rx_buffer;
+    TickType_t last_activity_tick{0};
+  };
 
   struct TunnelClient {
     bool connected{false};
@@ -225,6 +237,7 @@ class GatewayKnxTpIpRouter {
     uint8_t received_sequence{255};
     uint8_t send_sequence{0};
     uint16_t individual_address{0};
+    int tcp_sock{-1};
     TickType_t last_activity_tick{0};
     ::sockaddr_in control_remote{};
     ::sockaddr_in data_remote{};
@@ -237,6 +250,9 @@ class GatewayKnxTpIpRouter {
   void finishTask();
   void closeSockets();
   bool configureSocket();
+  void handleTcpAccept();
+  void handleTcpClient(TcpClient& client);
+  void closeTcpClient(TcpClient& client);
   bool configureTpUart();
   bool initializeTpUart();
   bool configureProgrammingGpio();
@@ -276,7 +292,12 @@ class GatewayKnxTpIpRouter {
   void sendSearchResponse(uint16_t service, const ::sockaddr_in& remote,
                           const std::set<uint8_t>& requested_dibs = {});
   void sendDescriptionResponse(const ::sockaddr_in& remote);
-  std::array<uint8_t, 8> localHpaiForRemote(const ::sockaddr_in& remote) const;
+  bool sendPacket(const std::vector<uint8_t>& packet, const ::sockaddr_in& remote) const;
+  bool sendPacketToTunnelClient(const TunnelClient& client,
+                                const std::vector<uint8_t>& packet) const;
+  bool currentTransportAllowsTcpHpai() const;
+  std::optional<std::array<uint8_t, 8>> localHpaiForRemote(const ::sockaddr_in& remote,
+                                                          bool tcp = false) const;
   std::vector<uint8_t> buildDeviceInfoDib(const ::sockaddr_in& remote) const;
   std::vector<uint8_t> buildSupportedServiceDib() const;
   std::vector<uint8_t> buildExtendedDeviceInfoDib() const;
@@ -298,8 +319,10 @@ class GatewayKnxTpIpRouter {
   void selectOpenKnxNetworkInterface(const ::sockaddr_in& remote);
   bool emitOpenKnxGroupValue(uint16_t group_object_number, const uint8_t* data, size_t len);
   bool shouldRouteDaliApplicationFrames() const;
+  uint8_t advertisedMedium() const;
   void syncOpenKnxConfigFromDevice();
-  uint16_t effectiveIndividualAddress() const;
+  uint16_t effectiveIpInterfaceIndividualAddress() const;
+  uint16_t effectiveKnxDeviceIndividualAddress() const;
   uint16_t effectiveTunnelAddress() const;
   void pollTpUart();
   void pollProgrammingButton();
@@ -322,9 +345,12 @@ class GatewayKnxTpIpRouter {
   std::atomic_bool stop_requested_{false};
   std::atomic_bool started_{false};
   int udp_sock_{-1};
+  int tcp_sock_{-1};
+  int active_tcp_sock_{-1};
   int tp_uart_port_{-1};
   std::vector<uint32_t> multicast_joined_interfaces_;
   TickType_t network_refresh_tick_{0};
+  std::array<TcpClient, kMaxTcpClients> tcp_clients_{};
   std::array<TunnelClient, kMaxTunnelClients> tunnel_clients_{};
   uint8_t last_tunnel_channel_id_{0};
   std::vector<uint8_t> tp_rx_frame_;