GPS: a Unicore '#' log marks the GPS source address too

Shared/AgOpenWeb.RemoteServer/wwwroot/app.js

@@ -2890,7 +2890,7 @@ function renderSystemData() {
   SD.hdual.classList.toggle('sd-bad', !!s.dualHeadingMissing);
   const ago = v => tr('{n} s ago', { n: v < 10 ? v.toFixed(1) : Math.round(v) });
   const rows = (d ? d.sentences : []).map(x =>
-    '<div class="sd-sent' + (x.age > 2 ? ' stale' : '') + '"><div class="sd-senthead"><span' + (x.type === 'REJECTED' ? '>' + esc(tr('Not accepted', {})) : ' translate="no">$' + esc(x.type)) +
+    '<div class="sd-sent' + (x.age > 2 ? ' stale' : '') + '"><div class="sd-senthead"><span' + (x.type === 'REJECTED' ? '>' + esc(tr('Not accepted', {})) : ' translate="no">' + (x.type === 'INSPVAX' ? '#' : '$') + esc(x.type)) +
     '</span><span>' + esc(ago(x.age)) + '</span></div><div class="sd-senttext" translate="no">' + esc(x.text) + '</div></div>');
   const html = rows.length ? rows.join('')
     : '<div class="sa-hint">' + esc(s.gpsSentence === 'SIM' ? tr('The simulator is supplying the position; no sentence is being received.', {})

Shared/AgOpenWeb.Services/UdpCommunicationService.cs

@@ -419,8 +419,11 @@ private void ProcessReceivedData(byte[] data, IPEndPoint remoteEndPoint)
                     Timestamp = DateTime.Now
                 });
             }
-            else if (data.Length > 0 && data[0] == (byte)'$')
+            else if (data.Length > 0 && (data[0] == (byte)'$' || data[0] == (byte)'#' || data[0] == (byte)'%'))
             {
+                // A '$' sentence or a Unicore '#'/'%' log: this is where the position comes
+                // from, so the RTCM corrections go back to this address (unicast on 2233) and
+                // Network IO names it.
                 MarkSourceSeen(SourceGpsNmea, remoteEndPoint);
 
                 // Text NMEA sentence (starts with $)

Tests/AgOpenWeb.Services.Tests/UdpGpsPortsTests.cs

@@ -39,6 +39,42 @@ public IReadOnlyList<LocalNetworkAddress> GetIPv4Addresses() =>
             new[] { new LocalNetworkAddress(IPAddress.Loopback, 8, "lo0") };
     }
 
+    /// <summary>A receiver that prints only Unicore '#' logs (a UM981) is a GPS source too.</summary>
+    [Test]
+    public async Task A_hash_log_marks_the_GPS_source_address()
+    {
+        try
+        {
+            using var probe = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
+            probe.Bind(new IPEndPoint(IPAddress.Any, UdpCommunicationService.ModulePort));
+        }
+        catch (SocketException)
+        {
+            Assert.Ignore("port 9999 is held by another process on this machine");
+        }
+
+        var udp = new UdpCommunicationService(new Loopback());
+        await udp.StartAsync();
+        try
+        {
+            const string body = "#INSPVAXA,COM3,0,80.0,FINE,2439,503918.400,0,424572,0;INS_ALIGNING,NONE,0.0,0.0,-17.0,17.0,0.0,0.0,0.0,0.0,0.0,0.0,0,0,0,0,0,0,0,0,0,0,0";
+            var line = Encoding.ASCII.GetBytes(body + "*" + AgOpenWeb.Services.Gps.UnicoreCrc32.Compute(Encoding.ASCII.GetBytes(body[1..])).ToString("x8") + "\r\n");
+            using var sender = new UdpClient();
+            IPAddress? source = null;
+            for (int attempt = 0; attempt < 20 && source == null; attempt++)
+            {
+                sender.Send(line, line.Length, new IPEndPoint(IPAddress.Loopback, UdpCommunicationService.ModulePort));
+                for (int wait = 0; wait < 20 && source == null; wait++) { await Task.Delay(25); source = udp.GetGpsSourceAddress(); }
+            }
+            Assert.That(source, Is.EqualTo(IPAddress.Loopback));
+        }
+        finally
+        {
+            await udp.StopAsync();
+            udp.Dispose();
+        }
+    }
+
     [TestCase(UdpCommunicationService.Gps1Port, GpsSource.Gps1)]
     [TestCase(UdpCommunicationService.Gps2Port, GpsSource.Gps2)]
     [TestCase(UdpCommunicationService.ModulePort, GpsSource.ModulePort)]
@@ -78,6 +114,7 @@ public async Task A_sentence_on_a_GPS_port_reaches_the_parser_with_its_source(in
             }
             Assert.That(seen, Is.True, $"no fix parsed from port {port}");
             Assert.That(steer.LastGpsSource, Is.EqualTo(expected));
+            Assert.That(udp.GetGpsSourceAddress(), Is.EqualTo(IPAddress.Loopback), "where the corrections go back to");
         }
         finally
         {