Add method ConnectedToWifi.

internal/platform/implementation/linux/wifi_direct.cc

@@ -129,6 +129,16 @@ bool NetworkManagerWifiDirectMedium::DisconnectWifiDirect() {
   return true;
 }
 
+bool NetworkManagerWifiDirectMedium::ConnectedToWifi() {
+  try {
+    auto mode = wireless_device_->Mode();
+    return mode == 2; // NM_802_11_MODE_INFRA
+  } catch (const sdbus::Error &e) {
+    DBUS_LOG_PROPERTY_GET_ERROR(wireless_device_, "Mode", e);
+    return false;
+  }
+}
+
 bool NetworkManagerWifiDirectMedium::StartWifiDirect(
     WifiDirectCredentials *wifi_direct_credentials) {
   // According to the comments in the windows implementation, the wifi direct

internal/platform/implementation/linux/wifi_direct.h

@@ -11,7 +11,7 @@
 namespace nearby {
 namespace linux {
 class NetworkManagerWifiDirectMedium : public api::WifiDirectMedium {
-public:  
+public:
   NetworkManagerWifiDirectMedium(
       sdbus::IConnection &system_bus,
       std::shared_ptr<NetworkManager> network_manager,
@@ -32,12 +32,15 @@ public:
 
   bool StartWifiDirect(WifiDirectCredentials *wifi_direct_credentials) override;
   bool StopWifiDirect() override;
-  
+
   absl::optional<std::pair<std::int32_t, std::int32_t>>
   GetDynamicPortRange() override {
     return std::nullopt;
   }
 
+private:
+  bool ConnectedToWifi();
+
   sdbus::IConnection &system_bus_;
   std::shared_ptr<NetworkManager> network_manager_;
   std::unique_ptr<NetworkManagerWifiMedium> wireless_device_;