[CI] [SKIP TESTS] Add detailed Probe-Agent connection diagnostics

backend/shared/tests/MoShiro.Measurement.Tests/MsQuicConnectionTests.cs

@@ -1,4 +1,5 @@
 using System.Net;
+using System.Collections.Concurrent;
 using System.Runtime.InteropServices;
 using System.Security.Cryptography;
 using System.Security.Cryptography.X509Certificates;
@@ -31,11 +32,23 @@ public sealed class MsQuicConnectionTests
     [Fact]
     public async Task DatagramConnection_CanSendCloseAndReconnect_WithoutBlockingNativeWorkers()
     {
+        var log = new CaptureLog();
+        var counters = new DataPlaneCounters();
+        var router = new MeasurementDatagramRouter(new SingleSession(new DataSession(1, new byte[32])), null,
+            new MonoClock(TimeProvider.System), counters, log);
         using ECDsa key = ECDsa.Create(ECCurve.NamedCurves.nistP256);
         var request = new CertificateRequest("CN=localhost", key, HashAlgorithmName.SHA256);
         using X509Certificate2 certificate = request.CreateSelfSigned(DateTimeOffset.UnixEpoch, DateTimeOffset.UnixEpoch.AddYears(100));
         await using var listener = new MsQuicListener(IPAddress.Loopback, [0], certificate,
-            (connection, data) => connection.Send(data), NullNodeLog.Instance, null);
+            (connection, data) =>
+            {
+                // Bad measurement payloads must be counted without flooding logs.
+                for (int i = 0; i < 100; i++)
+                {
+                    router.Dispatch(connection, data);
+                }
+                connection.Send(data);
+            }, log, null);
         listener.Start();
 
         for (int attempt = 0; attempt < 3; attempt++)
@@ -43,7 +56,7 @@ public sealed class MsQuicConnectionTests
             var reply = new TaskCompletionSource<byte[]>(TaskCreationOptions.RunContinuationsAsynchronously);
             using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(10));
             MsQuicConnection client = await MsQuicConnection.ConnectAsync(IPAddress.Loopback, listener.BoundPorts[0], 0,
-                key.ExportSubjectPublicKeyInfo(), (_, data) => reply.TrySetResult(data.ToArray()), NullNodeLog.Instance, timeout.Token);
+                key.ExportSubjectPublicKeyInfo(), (_, data) => reply.TrySetResult(data.ToArray()), log, timeout.Token);
             try
             {
                 while (!client.IsReady)
@@ -72,6 +85,22 @@ public sealed class MsQuicConnectionTests
                 await client.WaitForShutdownAsync().WaitAsync(TimeSpan.FromSeconds(3));
             }
         }
+        Assert.True(counters.DroppedInvalid >= 300);
+        var dropped = Assert.Single(log.Items, x => x.Message == "measurement datagram dropped");
+        Assert.Equal("invalid_header", dropped.Fields["reason"]);
+        Assert.NotNull(dropped.Fields["remote"]);
+        Assert.NotNull(dropped.Fields["quic_id"]);
+        var connected = log.Items.Where(x => x.Message == "MsQuic QUIC handshake completed").ToArray();
+        Assert.Equal(6, connected.Select(x => x.Fields["quic_id"]).Distinct().Count());
+        Assert.All(connected, entry => Assert.NotNull(entry.Fields["remote"]));
+        Assert.DoesNotContain(log.Items.SelectMany(x => x.Fields.Keys), key => key is "key" or "session_id" or "mac" or "signature");
     }
 
+    private sealed class CaptureLog : INodeLog
+    {
+        public ConcurrentQueue<(string Message, Dictionary<string, object?> Fields)> Items { get; } = new();
+
+        public void Write(NodeLogLevel level, string message, params (string Key, object? Value)[] fields) =>
+            Items.Enqueue((message, fields.ToDictionary(x => x.Key, x => x.Value)));
+    }
 }