Current network adapter (#133)

* GetCurrentAdapterName added

* better password length handling

* Update src/Unosquare.RaspberryIO/Computer/NetworkSettings.cs

Co-Authored-By: Carlos Solorzano <[email protected]>

* Update src/Unosquare.RaspberryIO/Computer/NetworkSettings.cs

Co-Authored-By: Carlos Solorzano <[email protected]>

* fix if

Author: Serk352

src/Unosquare.RaspberryIO/Computer/NetworkSettings.cs

@@ -98,13 +98,17 @@ public async Task<List<WirelessNetworkInfo>> RetrieveWirelessNetworks(string[] a
         /// </summary>
         /// <param name="adapterName">Name of the adapter.</param>
         /// <param name="networkSsid">The network ssid.</param>
-        /// <param name="password">The password.</param>
+        /// <param name="password">The password (8 characters as minimum length).</param>
         /// <param name="countryCode">The 2-letter country code in uppercase. Default is US.</param>
         /// <returns>True if successful. Otherwise, false.</returns>
         public async Task<bool> SetupWirelessNetwork(string adapterName, string networkSsid, string password = null, string countryCode = "US")
         {
             // TODO: Get the country where the device is located to set 'country' param in payload var
             var payload = $"country={countryCode}\nctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev\nupdate_config=1\n";
+
+            if (!string.IsNullOrWhiteSpace(password) && password.Length < 8)
+                throw new InvalidOperationException("The password must be at least 8 characters length.");
+
             payload += string.IsNullOrEmpty(password)
                 ? $"network={{\n\tssid=\"{networkSsid}\"\n\tkey_mgmt=NONE\n\t}}\n"
                 : $"network={{\n\tssid=\"{networkSsid}\"\n\tpsk=\"{password}\"\n\t}}\n";
@@ -215,12 +219,25 @@ public async Task<List<NetworkAdapterInfo>> RetrieveAdapters()
             return result.OrderBy(x => x.Name).ToList();
         }
 
+        /// <summary>
+        /// Retrieves the current network adapter.
+        /// </summary>
+        /// <returns>The name of the current network adapter.</returns>
+        public static async Task<string> GetCurrentAdapterName()
+        {
+            var result = await ProcessRunner.GetProcessOutputAsync("route").ConfigureAwait(false);
+            var defaultLine = result.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries)
+                                .FirstOrDefault(l => l.StartsWith("default", StringComparison.OrdinalIgnoreCase));
+
+            return defaultLine?.Trim().Substring(defaultLine.LastIndexOf(" ", StringComparison.OrdinalIgnoreCase) + 1);
+        }
+
         /// <summary>
         /// Retrieves current wireless connected network name.
         /// </summary>
         /// <returns>The connected network name.</returns>
         public Task<string> GetWirelessNetworkName() => ProcessRunner.GetProcessOutputAsync("iwgetid", "-r");
-        
+
         private static void GetIPv4(string indentedLine, NetworkAdapterInfo adapter)
         {
             var addressText = ParseOutputTagFromLine(indentedLine, "inet addr:") ??