OD uses UDP, so bind test to account for that

src/Tgstation.Server.Host/Components/InstanceManager.cs

@@ -648,7 +648,7 @@ namespace Tgstation.Server.Host.Components
 
 			// This runs before the real socket is opened, ensures we don't perform reattaches unless we're fairly certain the bind won't fail
 			// If it does fail, DD will be killed.
-			SocketExtensions.BindTest(platformIdentifier, serverPortProvider.HttpApiPort, true);
+			SocketExtensions.BindTest(platformIdentifier, serverPortProvider.HttpApiPort, true, false);
 		}
 
 		/// <summary>

src/Tgstation.Server.Host/Components/Session/SessionControllerFactory.cs

@@ -130,9 +130,10 @@ namespace Tgstation.Server.Host.Components.Session
 		/// Check if a given <paramref name="port"/> can be bound to.
 		/// </summary>
 		/// <param name="port">The port number to test.</param>
+		/// <param name="engineType">The <see cref="EngineType"/> we're bind testing for.</param>
 		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation.</param>
 		/// <returns>A <see cref="ValueTask"/> representing the running operation.</returns>
-		async ValueTask PortBindTest(ushort port, CancellationToken cancellationToken)
+		async ValueTask PortBindTest(ushort port, EngineType engineType, CancellationToken cancellationToken)
 		{
 			logger.LogTrace("Bind test: {port}", port);
 			try
@@ -142,7 +143,7 @@ namespace Tgstation.Server.Host.Components.Session
 				for (var i = 0; i < MaxAttempts; ++i)
 					try
 					{
-						SocketExtensions.BindTest(platformIdentifier, port, false);
+						SocketExtensions.BindTest(platformIdentifier, port, false, engineType == EngineType.OpenDream);
 						if (i > 0)
 							logger.LogDebug("Clearing the socket took {iterations} attempts :/", i + 1);
 
@@ -271,7 +272,7 @@ namespace Tgstation.Server.Host.Components.Session
 				if (engineType == EngineType.Byond)
 					await CheckPagerIsNotRunning();
 
-				await PortBindTest(launchParameters.Port.Value, cancellationToken);
+				await PortBindTest(launchParameters.Port.Value, engineType, cancellationToken);
 
 				string outputFilePath = null;
 				var preserveLogFile = true;

src/Tgstation.Server.Host/Extensions/SocketExtensions.cs

@@ -17,7 +17,8 @@ namespace Tgstation.Server.Host.Extensions
 		/// <param name="platformIdentifier">The <see cref="PlatformIdentifier"/> to use.</param>
 		/// <param name="port">The port number to bind to.</param>
 		/// <param name="includeIPv6">If IPV6 should be tested as well.</param>
-		public static void BindTest(IPlatformIdentifier platformIdentifier, ushort port, bool includeIPv6)
+		/// <param name="udp">If we're bind testing for UDP. If <see langword="false"/> TCP will be checked.</param>
+		public static void BindTest(IPlatformIdentifier platformIdentifier, ushort port, bool includeIPv6, bool udp)
 		{
 			ArgumentNullException.ThrowIfNull(platformIdentifier);
 			ProcessExecutor.WithProcessLaunchExclusivity(() =>
@@ -26,12 +27,16 @@ namespace Tgstation.Server.Host.Extensions
 					includeIPv6
 						? AddressFamily.InterNetworkV6
 						: AddressFamily.InterNetwork,
-					SocketType.Stream,
-					ProtocolType.Tcp);
+					udp
+						? SocketType.Dgram
+						: SocketType.Stream,
+					udp
+						? ProtocolType.Udp
+						: ProtocolType.Tcp);
 
 				socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ExclusiveAddressUse, true);
 				socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, false);
-				if (platformIdentifier.IsWindows)
+				if (!udp && platformIdentifier.IsWindows)
 					socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontLinger, true);
 
 				if (includeIPv6)

src/Tgstation.Server.Host/Utils/PortAllocator.cs

@@ -101,7 +101,8 @@ namespace Tgstation.Server.Host.Utils
 
 					try
 					{
-						SocketExtensions.BindTest(platformIdentifier, port, false);
+						SocketExtensions.BindTest(platformIdentifier, port, false, true);
+						SocketExtensions.BindTest(platformIdentifier, port, false, false);
 					}
 					catch (Exception ex)
 					{

tests/Tgstation.Server.Tests/Live/Instance/WatchdogTest.cs

@@ -1,5 +1,6 @@
 using Byond.TopicSender;
 
+using Microsoft.AspNetCore.DataProtection;
 using Microsoft.Extensions.Logging;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
@@ -19,6 +20,7 @@ using System.Net;
 using System.Net.Sockets;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics.Arm;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -39,6 +41,8 @@ using Tgstation.Server.Host.Extensions;
 using Tgstation.Server.Host.IO;
 using Tgstation.Server.Host.System;
 
+using static NuGet.Frameworks.FrameworkConstants;
+
 namespace Tgstation.Server.Tests.Live.Instance
 {
 	sealed class WatchdogTest : JobsRequiredTest
@@ -544,10 +548,19 @@ namespace Tgstation.Server.Tests.Live.Instance
 
 			JobResponse startJob;
 			if (new PlatformIdentifier().IsWindows) // Can't get address reuse to trigger on linux for some reason
-				using (var blockSocket = new Socket(SocketType.Stream, ProtocolType.Tcp))
+				using (var blockSocket = new Socket(
+					testVersion.Engine.Value == EngineType.OpenDream
+						? SocketType.Dgram
+						: SocketType.Stream,
+					testVersion.Engine.Value == EngineType.OpenDream
+						? ProtocolType.Udp
+						: ProtocolType.Tcp))
 				{
 					blockSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ExclusiveAddressUse, true);
 					blockSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, false);
+					if (testVersion.Engine.Value != EngineType.OpenDream)
+						blockSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontLinger, true);
+
 					blockSocket.Bind(new IPEndPoint(IPAddress.Any, ddPort));
 
 					// Don't use StartDD here
@@ -742,7 +755,7 @@ namespace Tgstation.Server.Tests.Live.Instance
 			{
 				try
 				{
-					SocketExtensions.BindTest(new PlatformIdentifier(), ddPort, false);
+					SocketExtensions.BindTest(new PlatformIdentifier(), ddPort, false, testVersion.Engine == EngineType.OpenDream);
 					break;
 				}
 				catch

tests/Tgstation.Server.Tests/Live/TestLiveServer.cs

@@ -546,7 +546,6 @@ namespace Tgstation.Server.Tests.Live
 		{
 			// cleanup existing directories
 			new LiveTestingServer(null, false).Dispose();
-
 			const string PrivateKey = "adlfj73ywifhks7iwrgfegjs";
 
 			var controllerAddress = new Uri("http://localhost:15011");