Merge pull request #577 from WildernessLabs/bug/linux-ntp

handling of Linux NTP and time zone shenanigans

Source/Meadow.Core/NtpClientBase.cs

@@ -0,0 +1,100 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+using static Meadow.Logging.Logger;
+
+namespace Meadow;
+
+/// <summary>
+/// base Client for Network Time Protocol
+/// </summary>
+public abstract class NtpClientBase : INtpClient
+{
+    private int _ntpLock = 1;
+
+    /// <inheritdoc/>
+    public event TimeChangedEventHandler TimeChanged = default!;
+
+    /// <inheritdoc/>
+    public abstract bool Enabled { get; }
+    /// <inheritdoc/>
+    public abstract TimeSpan PollPeriod { get; set; }
+
+    /// <summary>
+    /// Raises the TimeChanged event with a given time
+    /// </summary>
+    /// <param name="utcTime">The new time</param>
+    protected void RaiseTimeChanged(DateTime utcTime) => TimeChanged?.Invoke(utcTime);
+
+    /// <inheritdoc/>
+    public Task<bool> Synchronize(string? ntpServer = null)
+    {
+        if (ntpServer == null)
+        {
+            if (Resolver.Device.PlatformOS.NtpServers.Length == 0)
+            {
+                ntpServer = "0.pool.ntp.org";
+                Resolver.Log.Info($"No configured NTP servers. Defaulting to {ntpServer}", MessageGroup.Core);
+            }
+            else
+            {
+                ntpServer = Resolver.Device.PlatformOS.NtpServers[0];
+            }
+        }
+
+        if (Interlocked.Exchange(ref _ntpLock, 0) == 1)
+        {
+            try
+            {
+                var m_ntpPacket = new byte[48];
+                //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)
+                m_ntpPacket[0] = 0x1B;
+
+                UdpClient client = new UdpClient();
+                client.Connect(ntpServer, 123);
+                client.Send(m_ntpPacket, m_ntpPacket.Length);
+                IPEndPoint ep = new IPEndPoint(IPAddress.Any, 0);
+                byte[] data = client.Receive(ref ep);
+
+                // receive date data is at offset 32
+                // Data is 64 bits - first 32 is seconds
+                // it is not in an endian order, so we must rearrange
+                byte[] endianSeconds = new byte[4];
+                endianSeconds[0] = data[32 + 3];
+                endianSeconds[1] = data[32 + 2];
+                endianSeconds[2] = data[32 + 1];
+                endianSeconds[3] = data[32 + 0];
+                uint seconds = BitConverter.ToUInt32(endianSeconds, 0);
+
+                // second 32 is fraction of a second
+                endianSeconds[0] = data[32 + 7];
+                endianSeconds[1] = data[32 + 6];
+                endianSeconds[2] = data[32 + 5];
+                endianSeconds[3] = data[32 + 4];
+
+                uint fraction = BitConverter.ToUInt32(endianSeconds, 0);
+
+                var s = double.Parse($"{seconds}.{fraction}");
+
+                var dt = new DateTime(1900, 1, 1).AddSeconds(s);
+                Resolver.Device.PlatformOS.SetClock(dt);
+                TimeChanged?.Invoke(dt);
+                return Task.FromResult(true);
+            }
+            catch (Exception ex)
+            {
+                Resolver.Log.Error($"Failed to query NTP Server: '{ex.Message}'.", MessageGroup.Core);
+                return Task.FromResult(false);
+            }
+            finally
+            {
+                Interlocked.Exchange(ref _ntpLock, 1);
+            }
+
+        }
+
+        return Task.FromResult(false);
+    }
+}

Source/implementations/f7/Meadow.F7/Devices/NtpClient.cs

@@ -1,113 +1,31 @@
 using System;
-using System.Net;
-using System.Net.Sockets;
-using System.Threading;
-using System.Threading.Tasks;
-using static Meadow.Logging.Logger;
 
 namespace Meadow;
 
 /// <summary>
 /// Client for Network Time Protocol
 /// </summary>
-public class NtpClient : INtpClient
+public class NtpClient : NtpClientBase
 {
-    /// <summary>
-    /// Event raised when the device clock is adjusted by NTP
-    /// </summary>
-    public event TimeChangedEventHandler TimeChanged = default!;
-
     /// <summary>
     /// Returns <c>true</c> if the NTP Client is enabled
     /// </summary>
-    public bool Enabled => F7PlatformOS.GetBoolean(IPlatformOS.ConfigurationValues.GetTimeAtStartup);
+    public override bool Enabled => F7PlatformOS.GetBoolean(IPlatformOS.ConfigurationValues.GetTimeAtStartup);
 
     internal NtpClient()
     { }
 
     /// <summary>
     /// Time period that the NTP client attempts to query the NTP time server(s)
     /// </summary>
-    public TimeSpan PollPeriod
+    public override TimeSpan PollPeriod
     {
         get => TimeSpan.Zero; // currently only happens at startup
         set => throw new PlatformNotSupportedException("Changing NTP Poll Frequency not currently supported");
     }
 
     internal void RaiseTimeChanged()
     {
-        TimeChanged?.Invoke(DateTime.UtcNow);
-    }
-
-    private int _ntpLock = 1;
-
-    /// <inheritdoc/>
-    public Task<bool> Synchronize(string? ntpServer = null)
-    {
-        if (ntpServer == null)
-        {
-            if (Resolver.Device.PlatformOS.NtpServers.Length == 0)
-            {
-                ntpServer = "0.pool.ntp.org";
-                Resolver.Log.Info($"No configured NTP servers. Defaulting to {ntpServer}", MessageGroup.Core);
-            }
-            else
-            {
-                ntpServer = Resolver.Device.PlatformOS.NtpServers[0];
-            }
-        }
-
-        if (Interlocked.Exchange(ref _ntpLock, 0) == 1)
-        {
-            try
-            {
-                var m_ntpPacket = new byte[48];
-                //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)
-                m_ntpPacket[0] = 0x1B;
-
-                UdpClient client = new UdpClient();
-                client.Connect(ntpServer, 123);
-                client.Send(m_ntpPacket, m_ntpPacket.Length);
-                IPEndPoint ep = new IPEndPoint(IPAddress.Any, 0);
-                byte[] data = client.Receive(ref ep);
-
-                // receive date data is at offset 32
-                // Data is 64 bits - first 32 is seconds
-                // it is not in an endian order, so we must rearrange
-                byte[] endianSeconds = new byte[4];
-                endianSeconds[0] = data[32 + 3];
-                endianSeconds[1] = data[32 + 2];
-                endianSeconds[2] = data[32 + 1];
-                endianSeconds[3] = data[32 + 0];
-                uint seconds = BitConverter.ToUInt32(endianSeconds, 0);
-
-                // second 32 is fraction of a second
-                endianSeconds[0] = data[32 + 7];
-                endianSeconds[1] = data[32 + 6];
-                endianSeconds[2] = data[32 + 5];
-                endianSeconds[3] = data[32 + 4];
-
-                uint fraction = BitConverter.ToUInt32(endianSeconds, 0);
-
-                var s = double.Parse($"{seconds}.{fraction}");
-
-                var dt = new DateTime(1900, 1, 1).AddSeconds(s);
-                Resolver.Device.PlatformOS.SetClock(dt);
-                TimeChanged?.Invoke(dt);
-                return Task.FromResult(true);
-            }
-            catch (Exception ex)
-            {
-                Resolver.Log.Error($"Failed to query NTP Server: '{ex.Message}'.", MessageGroup.Core);
-                return Task.FromResult(false);
-            }
-            finally
-            {
-                Interlocked.Exchange(ref _ntpLock, 1);
-            }
-
-        }
-
-        return Task.FromResult(false);
+        RaiseTimeChanged(DateTime.UtcNow);
     }
 }

Source/implementations/linux/Meadow.Linux/Interop/Interop.Time.cs

@@ -7,6 +7,19 @@ namespace Meadow
     [SuppressUnmanagedCodeSecurity]
     internal static partial class Interop
     {
+
+        [DllImport(LIBC, SetLastError = true)]
+        public static extern void tzset();
+
+        [DllImport(LIBC, SetLastError = true)]
+        public static extern ref Rtc_time localtime(ref long time_t);
+
+        [DllImport(LIBC, SetLastError = true)]
+        public static extern IntPtr localtime_r(ref long time_t, ref Tm tm);
+
+        [DllImport(LIBC, SetLastError = true)]
+        public static extern IntPtr gmtime_r(ref long time_t, ref Tm tm);
+
         [DllImport(LIBC, SetLastError = true)]
         public static extern int clock_settime(Clock clock, ref Timespec timespec);
 
@@ -26,6 +39,21 @@ public enum Clock
             //#define CLOCK_BOOTTIME			6
         }
 
+        public struct Tm
+        {
+            public int tm_sec;
+            public int tm_min;
+            public int tm_hour;
+            public int tm_mday;
+            public int tm_mon;
+            public int tm_year;
+            public int tm_wday;
+            public int tm_yday;
+            public int tm_isdst;
+            //            public long tm_gmtoff;           /* Seconds east of UTC */
+            //            public string tm_zone;      /* Timezone abbreviation */
+        }
+
         public struct Rtc_time
         {
             /*

Source/implementations/linux/Meadow.Linux/PlatformOS/LinuxNtpClient.cs

@@ -1,27 +1,19 @@
 using System;
-using System.Threading.Tasks;
 
 namespace Meadow;
 
 /// <summary>
 /// Represents an NTP (Network Time Protocol) client for Linux.
 /// </summary>
-public class LinuxNtpClient : INtpClient
+public class LinuxNtpClient : NtpClientBase
 {
-    /// <inheritdoc/>
-    public bool Enabled => false;
-
-    /// <inheritdoc/>
-    public TimeSpan PollPeriod { get; set; }
+    internal LinuxNtpClient()
+    {
+    }
 
     /// <inheritdoc/>
-    public event TimeChangedEventHandler? TimeChanged;
+    public override bool Enabled => false;
 
     /// <inheritdoc/>
-    public Task<bool> Synchronize(string? ntpServer = null)
-    {
-        TimeChanged?.Invoke(DateTime.UtcNow);
-
-        throw new NotImplementedException();
-    }
+    public override TimeSpan PollPeriod { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
 }

Source/implementations/linux/Meadow.Linux/PlatformOS/LinuxPlatformOS.cs

@@ -117,6 +117,9 @@ public void Initialize(DeviceCapabilities capabilities, string[]? args)
         }
     }
 
+    /// <inheritdoc/>
+    public string[] NtpServers => new string[] { "pool.ntp.org" };
+
     /// <summary>
     /// Gets the name of all available serial ports on the platform
     /// </summary>
@@ -151,6 +154,17 @@ public virtual Temperature GetCpuTemperature()
     /// <param name="dateTime"></param>
     public void SetClock(DateTime dateTime)
     {
+        if (dateTime.Kind != DateTimeKind.Utc)
+        {
+            TimeZoneInfo localZone = TimeZoneInfo.Local;
+            dateTime = dateTime.AddMinutes(localZone.BaseUtcOffset.TotalMinutes);
+
+            if (localZone.IsDaylightSavingTime(dateTime))
+            {
+                dateTime = dateTime.AddHours(1);
+            }
+        }
+
         var ts = Interop.Timespec.From(dateTime);
         var result = Interop.clock_settime(Interop.Clock.REALTIME, ref ts);
 
@@ -300,9 +314,6 @@ public DigitalStorage GetPrimaryDiskSpaceInUse()
     /// <inheritdoc/>
     public AllocationInfo GetMemoryAllocationInfo() => throw new NotImplementedException();
 
-    /// <inheritdoc/>
-    public string[] NtpServers => throw new NotImplementedException();
-
     /// <inheritdoc/>
     public bool RebootOnUnhandledException => false;