Meadow: Network helper methods (NTP, WiFi discovery, requests, etc.)

NetworkHelpers.cs

public static class NetworkHelpers
{
    public static async Task GetWebPageViaHttpClient(string uri)
    {
        Console.WriteLine($"Requesting {uri} - {DateTime.Now}");

        using (var client = new HttpClient())
        {
            try
            {
                HttpResponseMessage response = await client.GetAsync(uri);
                response.EnsureSuccessStatusCode();
                string responseBody = await response.Content.ReadAsStringAsync();
                Console.WriteLine($"Success [length: {responseBody.Length}]");
            }
            catch (TaskCanceledException cancelledEx)
            {
                Console.WriteLine($"Request timed out: {cancelledEx.Message}");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Request exception: {ex.ToString()}\n\t{ex.InnerException?.ToString() ?? ""}");
            }
        }
    }

    public static async Task ScanForAccessPoints(IWiFiNetworkAdapter wifi)
    {
        Console.WriteLine("Getting list of access points.");
        var networks = await wifi.Scan(TimeSpan.FromSeconds(60));

        if (networks.Count > 0)
        {
            Console.WriteLine("|-------------------------------------------------------------|---------|");
            Console.WriteLine("|         Network Name             | RSSI |       BSSID       | Channel |");
            Console.WriteLine("|-------------------------------------------------------------|---------|");

            foreach (WifiNetwork accessPoint in networks)
            {
                Console.WriteLine($"| {accessPoint.Ssid,-32} | {accessPoint.SignalDbStrength,4} | {accessPoint.Bssid,17} |   {accessPoint.ChannelCenterFrequency,3}   |");
            }
        }
        else
        {
            Console.WriteLine($"No access points detected.");
        }
    }

    public static void DisplayNetworkInformation()
    {
        NetworkInterface[] adapters = NetworkInterface.GetAllNetworkInterfaces();
        if (adapters.Length == 0)
        {
            Console.WriteLine("No adapters available.");
        }
        foreach (NetworkInterface adapter in adapters)
        {
            IPInterfaceProperties properties = adapter.GetIPProperties();
            Console.WriteLine();
            Console.WriteLine(adapter.Description);
            Console.WriteLine(String.Empty.PadLeft(adapter.Description.Length, '='));
            Console.WriteLine($"  Adapter name: {adapter.Name}");
            Console.WriteLine($"  Interface type .......................... : {adapter.NetworkInterfaceType}");
            Console.WriteLine($"  Physical Address ........................ : {adapter.GetPhysicalAddress().ToString()}");
            Console.WriteLine($"  Operational status ...................... : {adapter.OperationalStatus}");
            string versions = String.Empty;
            if (adapter.Supports(NetworkInterfaceComponent.IPv4))
            {
                versions = "IPv4";
            }
            if (adapter.Supports(NetworkInterfaceComponent.IPv6))
            {
                if (versions.Length > 0)
                {
                    versions += " ";
                }
                versions += "IPv6";
            }
            Console.WriteLine($"  IP version .............................. : {versions}");
            if (adapter.Supports(NetworkInterfaceComponent.IPv4))
            {
                IPv4InterfaceProperties ipv4 = properties.GetIPv4Properties();
                Console.WriteLine("  MTU ..................................... : {0}", ipv4.Mtu);
            }
            if ((adapter.NetworkInterfaceType == NetworkInterfaceType.Wireless80211) || (adapter.NetworkInterfaceType == NetworkInterfaceType.Ethernet))
            {
                foreach (UnicastIPAddressInformation ip in adapter.GetIPProperties().UnicastAddresses)
                {
                    if (ip.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                    {
                        Console.WriteLine($"  IP address .............................. : {ip.Address.ToString()}");
                        Console.WriteLine($"  Subnet mask ............................. : {ip.IPv4Mask.ToString()}");
                    }
                }
            }
        }
    }

    /// <summary>
    /// https://stackoverflow.com/a/12150289/48700
    /// </summary>
    /// <param name="ntpServer">
    /// Defaults to the default Windows time server. Another option: any of [0-3].pool.ntp.org.
    /// </param>
    public static DateTime GetNetworkTime(string ntpServer = "time.windows.com")
    {
        // NTP message size - 16 bytes of the digest (RFC 2030)
        var ntpData = new byte[48];

        //Setting the Leap Indicator, Version Number and Mode values
        ntpData[0] = 0x1B; //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)

        var addresses = Dns.GetHostEntry(ntpServer).AddressList;

        //The UDP port number assigned to NTP is 123
        var ipEndPoint = new IPEndPoint(addresses[0], 123);
        //NTP uses UDP

        using (var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
        {
            socket.Connect(ipEndPoint);

            //Stops code hang if NTP is blocked
            socket.ReceiveTimeout = 3000;

            socket.Send(ntpData);
            socket.Receive(ntpData);
            socket.Close();
        }

        //Offset to get to the "Transmit Timestamp" field (time at which the reply 
        //departed the server for the client, in 64-bit timestamp format."
        const byte serverReplyTime = 40;

        //Get the seconds part
        ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);

        //Get the seconds fraction
        ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);

        // stackoverflow.com/a/3294698/162671
        Func<ulong, uint> SwapEndianness = (ulong x) =>
        {
            return (uint)(((x & 0x000000ff) << 24) +
                           ((x & 0x0000ff00) << 8) +
                           ((x & 0x00ff0000) >> 8) +
                           ((x & 0xff000000) >> 24));
        };
        //Convert From big-endian to little-endian
        intPart = SwapEndianness(intPart);
        fractPart = SwapEndianness(fractPart);

        var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);

        //**UTC** time
        var networkDateTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds((long)milliseconds);

        return networkDateTime.ToLocalTime();
    }

    static readonly HttpClient staticHttpClient = new HttpClient()
    {
        Timeout = TimeSpan.FromSeconds(10),
    };
    // TODO: Use IHttpClientFactory from NuGet Microsoft.Extensions.Http
    public static async Task GetWebPageViaStaticHttpClient(string uri)
    {
        Console.WriteLine($"Requesting {uri} - {DateTime.Now}");

        try
        {
            HttpResponseMessage response = await staticHttpClient.GetAsync(uri);
            response.EnsureSuccessStatusCode();
            string responseBody = await response.Content.ReadAsStringAsync();
            Console.WriteLine($"Success [length: {responseBody.Length}]");
        }
        catch (TaskCanceledException cancelledEx)
        {
            Console.WriteLine($"Request timed out: {cancelledEx.Message}");
            Console.WriteLine($"Failure");
        }
        catch (Exception e)
        {
            Console.WriteLine($"Request exception: {e.Message}");
            Console.WriteLine($"Failure");
        }
    }
}