Do not return 200 for exceptions

samples/NativeIISSample/Properties/launchSettings.json

@@ -12,6 +12,7 @@
       "commandName": "Executable",
       "executablePath": "$(IISExpressPath)",
       "commandLineArgs": "$(IISExpressArguments)",
+      "nativeDebugging": true,
       "environmentVariables": {
         "IIS_SITE_PATH": "$(MSBuildThisFileDirectory)",
         "ANCM_PATH": "$(TargetDir)$(AncmPath)",

src/Microsoft.AspNetCore.Server.IISIntegration/NativeMethods.cs

@@ -68,8 +68,8 @@ namespace Microsoft.AspNetCore.Server.IISIntegration
         [DllImport(AspNetCoreModuleDll)]
         internal unsafe static extern HttpApiTypes.HTTP_RESPONSE_V2* http_get_raw_response(IntPtr pInProcessHandler);
 
-        [DllImport(AspNetCoreModuleDll)]
-        public unsafe static extern void http_set_response_status_code(IntPtr pInProcessHandler, ushort statusCode, byte* pszReason);
+        [DllImport(AspNetCoreModuleDll, CharSet = CharSet.Ansi)]
+        public unsafe static extern int http_set_response_status_code(IntPtr pInProcessHandler, ushort statusCode, string pszReason);
 
         [DllImport(AspNetCoreModuleDll)]
         public unsafe static extern int http_read_request_bytes(IntPtr pInProcessHandler, byte* pvBuffer, int cbBuffer, out int dwBytesReceived, out bool fCompletionExpected);

src/Microsoft.AspNetCore.Server.IISIntegration/Server/IISHttpContext.cs

@@ -223,7 +223,7 @@ namespace Microsoft.AspNetCore.Server.IISIntegration
                 _reasonPhrase = value;
             }
         }
-        
+
         internal IISHttpServer Server
         {
             get { return _server; }
@@ -332,13 +332,10 @@ namespace Microsoft.AspNetCore.Server.IISIntegration
         public unsafe void SendResponseHeaders(bool appCompleted)
         {
             // Verifies we have sent the statuscode before writing a header
-            var reasonPhraseBytes = Encoding.UTF8.GetBytes(ReasonPhrase ?? ReasonPhrases.GetReasonPhrase(StatusCode));
+            var reasonPhrase = string.IsNullOrEmpty(ReasonPhrase) ? ReasonPhrases.GetReasonPhrase(StatusCode) : ReasonPhrase;
 
-            fixed (byte* pReasonPhrase = reasonPhraseBytes)
-            {
-                // This copies data into the underlying buffer
-                NativeMethods.http_set_response_status_code(_pInProcessHandler, (ushort)StatusCode, pReasonPhrase);
-            }
+            // This copies data into the underlying buffer
+            NativeMethods.http_set_response_status_code(_pInProcessHandler, (ushort)StatusCode, reasonPhrase);
 
             HttpResponseHeaders.IsReadOnly = true;
             foreach (var headerPair in HttpResponseHeaders)

src/RequestHandler/managedexports.cxx

@@ -74,13 +74,15 @@ Finished:
     return hr;
 }
 
-EXTERN_C __MIDL_DECLSPEC_DLLEXPORT VOID http_set_response_status_code(
+EXTERN_C __MIDL_DECLSPEC_DLLEXPORT
+HRESULT
+http_set_response_status_code(
     _In_ IN_PROCESS_HANDLER* pInProcessHandler,
     _In_ USHORT statusCode,
     _In_ PCSTR pszReason
 )
 {
-    pInProcessHandler->QueryHttpContext()->GetResponse()->SetStatus(statusCode, pszReason);
+    return pInProcessHandler->QueryHttpContext()->GetResponse()->SetStatus(statusCode, pszReason);
 }
 
 EXTERN_C __MIDL_DECLSPEC_DLLEXPORT

test/IISIntegration.FunctionalTests/IISIntegration.FunctionalTests.csproj

@@ -10,6 +10,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.AspNetCore.Server.IISIntegration\Microsoft.AspNetCore.Server.IISIntegration.csproj" />
+    <ProjectReference Include="..\IISTestSite\IISTestSite.csproj" />
   </ItemGroup>
 
   <ItemGroup>

test/IISIntegration.FunctionalTests/Inprocess/ResponseHeaderTests.cs

@@ -40,5 +40,25 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
             Assert.Equal("1", headerValues.First());
             Assert.Equal("2", headerValues.Last());
         }
+
+        [ConditionalFact]
+        public async Task ErrorCodeIsSetForExceptionDuringRequest()
+        {
+            var response = await _fixture.Client.GetAsync("Throw");
+            Assert.Equal(HttpStatusCode.InternalServerError, response.StatusCode);
+            Assert.Equal("Internal Server Error", response.ReasonPhrase);
+        }
+
+        [ConditionalTheory]
+        [InlineData(200, "custom", "custom")]
+        [InlineData(500, "", "Internal Server Error")]
+        [InlineData(999, "", "")]
+        public async Task CustomErrorCodeWorks(int code, string reason, string expectedReason)
+        {
+            var response = await _fixture.Client.GetAsync($"SetCustomErorCode?code={code}&reason={reason}");
+            Assert.Equal((HttpStatusCode)code, response.StatusCode);
+            Assert.Equal(expectedReason, response.ReasonPhrase);
+            Assert.Equal("Body", await response.Content.ReadAsStringAsync());
+        }
     }
 }

test/IISTestSite/Startup.cs

@@ -5,6 +5,7 @@ using System;
 using System.Diagnostics;
 using System.IO;
 using System.Net;
+using System.Reflection;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -23,35 +24,16 @@ namespace IISTestSite
     {
         public void Configure(IApplicationBuilder app)
         {
-            app.Map("/ServerVariable", ServerVariable);
-            app.Map("/AuthenticationAnonymous", AuthenticationAnonymous);
-            app.Map("/AuthenticationRestricted", AuthenticationRestricted);
-            app.Map("/AuthenticationForbidden", AuthenticationForbidden);
-            app.Map("/AuthenticationRestrictedNTLM", AuthenticationRestrictedNTLM);
-            app.Map("/FeatureCollectionSetRequestFeatures", FeatureCollectionSetRequestFeatures);
-            app.Map("/FeatureCollectionSetResponseFeatures", FeatureCollectionSetResponseFeatures);
-            app.Map("/FeatureCollectionSetConnectionFeatures", FeatureCollectionSetConnectionFeatures);
-            app.Map("/HelloWorld", HelloWorld);
-            app.Map("/LargeResponseBody", LargeResponseBody);
-            app.Map("/ResponseHeaders", ResponseHeaders);
-            app.Map("/ResponseInvalidOrdering", ResponseInvalidOrdering);
-            app.Map("/CheckEnvironmentVariable", CheckEnvironmentVariable);
-            app.Map("/CheckEnvironmentLongValueVariable", CheckEnvironmentLongValueVariable);
-            app.Map("/CheckAppendedEnvironmentVariable", CheckAppendedEnvironmentVariable);
-            app.Map("/CheckRemoveAuthEnvironmentVariable", CheckRemoveAuthEnvironmentVariable);
-            app.Map("/ReadAndWriteSynchronously", ReadAndWriteSynchronously);
-            app.Map("/ReadAndWriteEcho", ReadAndWriteEcho);
-            app.Map("/ReadAndWriteCopyToAsync", ReadAndWriteCopyToAsync);
-            app.Map("/ReadAndWriteEchoTwice", ReadAndWriteEchoTwice);
-            app.Map("/ReadAndWriteSlowConnection", ReadAndWriteSlowConnection);
-            app.Map("/WebsocketRequest", WebsocketRequest);
-            app.Map("/UpgradeFeatureDetection", UpgradeFeatureDetection);
-            app.Map("/TestInvalidReadOperations", TestInvalidReadOperations);
-            app.Map("/TestValidReadOperations", TestValidReadOperations);
-            app.Map("/TestInvalidWriteOperations", TestInvalidWriteOperations);
-            app.Map("/TestValidWriteOperations", TestValidWriteOperations);
-            app.Map("/TestReadOffsetWorks", TestReadOffsetWorks);
-            app.Map("/LargeResponseFile", LargeResponseFile);
+            foreach (var method in GetType().GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance))
+            {
+                var parameters = method.GetParameters();
+                if (method.Name != nameof(Configure) &&
+                    parameters.Length == 1 &&
+                    parameters[0].ParameterType == typeof(IApplicationBuilder))
+                {
+                    app.Map("/" + method.Name, innerAppBuilder => method.Invoke(this, new[] { innerAppBuilder }));
+                }
+            }
         }
 
         private void ServerVariable(IApplicationBuilder app)
@@ -231,6 +213,21 @@ namespace IISTestSite
             });
         }
 
+        private void Throw(IApplicationBuilder app)
+        {
+            app.Run(ctx => { throw new Exception(); });
+        }
+
+        private void SetCustomErorCode(IApplicationBuilder app)
+        {
+            app.Run(async ctx => {
+                    var feature = ctx.Features.Get<IHttpResponseFeature>();
+                    feature.ReasonPhrase = ctx.Request.Query["reason"];
+                    feature.StatusCode = int.Parse(ctx.Request.Query["code"]);
+                    await ctx.Response.WriteAsync("Body");
+                });
+        }
+
         private void HelloWorld(IApplicationBuilder app)
         {
             app.Run(async ctx =>