Source server variables from IIS when running ANCM in-proc (#10022)

src/Middleware/Middleware.sln

@@ -281,6 +281,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "samples", "samples", "{179A
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "HeaderPropagationSample", "HeaderPropagation\samples\HeaderPropagationSample\HeaderPropagationSample.csproj", "{CDE2E736-A034-4748-98C4-0DEDAAC8063D}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Server.IIS", "..\Servers\IIS\IIS\src\Microsoft.AspNetCore.Server.IIS.csproj", "{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -1527,6 +1529,18 @@ Global
 		{CDE2E736-A034-4748-98C4-0DEDAAC8063D}.Release|x64.Build.0 = Release|Any CPU
 		{CDE2E736-A034-4748-98C4-0DEDAAC8063D}.Release|x86.ActiveCfg = Release|Any CPU
 		{CDE2E736-A034-4748-98C4-0DEDAAC8063D}.Release|x86.Build.0 = Release|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Debug|x64.Build.0 = Debug|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Debug|x86.Build.0 = Debug|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Release|x64.ActiveCfg = Release|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Release|x64.Build.0 = Release|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Release|x86.ActiveCfg = Release|Any CPU
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1648,6 +1662,7 @@ Global
 		{8CDBD9C6-96D8-4987-AFCD-D248FBC7F02D} = {0437D207-864E-429C-92B4-9D08D290188C}
 		{179A159B-87EA-4353-BE92-4FB6CC05BC7D} = {0437D207-864E-429C-92B4-9D08D290188C}
 		{CDE2E736-A034-4748-98C4-0DEDAAC8063D} = {179A159B-87EA-4353-BE92-4FB6CC05BC7D}
+		{B9BE1823-B555-4AAB-AEBC-C8C3F48C8861} = {ACA6DDB9-7592-47CE-A740-D15BF307E9E0}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {83786312-A93B-4BB4-AB06-7C6913A59AFA}

src/Middleware/Rewrite/ref/Microsoft.AspNetCore.Rewrite.csproj

@@ -7,6 +7,7 @@
     <Compile Include="Microsoft.AspNetCore.Rewrite.netcoreapp3.0.cs" />
     <Reference Include="Microsoft.AspNetCore.Hosting.Abstractions"  />
     <Reference Include="Microsoft.AspNetCore.Http.Extensions"  />
+    <Reference Include="Microsoft.AspNetCore.Server.IIS"  />
     <Reference Include="Microsoft.Extensions.Configuration.Abstractions"  />
     <Reference Include="Microsoft.Extensions.FileProviders.Abstractions"  />
     <Reference Include="Microsoft.Extensions.Logging.Abstractions"  />

src/Middleware/Rewrite/ref/Microsoft.AspNetCore.Rewrite.netcoreapp3.0.cs

@@ -18,8 +18,8 @@ namespace Microsoft.AspNetCore.Rewrite
     }
     public static partial class IISUrlRewriteOptionsExtensions
     {
-        public static Microsoft.AspNetCore.Rewrite.RewriteOptions AddIISUrlRewrite(this Microsoft.AspNetCore.Rewrite.RewriteOptions options, Microsoft.Extensions.FileProviders.IFileProvider fileProvider, string filePath) { throw null; }
+        public static Microsoft.AspNetCore.Rewrite.RewriteOptions AddIISUrlRewrite(this Microsoft.AspNetCore.Rewrite.RewriteOptions options, Microsoft.Extensions.FileProviders.IFileProvider fileProvider, string filePath, bool alwaysUseManagedServerVariables = false) { throw null; }
-        public static Microsoft.AspNetCore.Rewrite.RewriteOptions AddIISUrlRewrite(this Microsoft.AspNetCore.Rewrite.RewriteOptions options, System.IO.TextReader reader) { throw null; }
+        public static Microsoft.AspNetCore.Rewrite.RewriteOptions AddIISUrlRewrite(this Microsoft.AspNetCore.Rewrite.RewriteOptions options, System.IO.TextReader reader, bool alwaysUseManagedServerVariables = false) { throw null; }
     }
     public partial interface IRule
     {
@@ -371,7 +371,7 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
     public partial class InputParser
     {
         public InputParser() { }
-        public InputParser(Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.IISRewriteMapCollection rewriteMaps) { }
+        public InputParser(Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.IISRewriteMapCollection rewriteMaps, bool alwaysUseManagedServerVariables) { }
         public Microsoft.AspNetCore.Rewrite.Internal.Pattern ParseInputString(string testString) { throw null; }
         public Microsoft.AspNetCore.Rewrite.Internal.Pattern ParseInputString(string testString, Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.UriMatchPart uriMatchPart) { throw null; }
     }
@@ -448,7 +448,7 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
     }
     public static partial class ServerVariables
     {
-        public static Microsoft.AspNetCore.Rewrite.Internal.PatternSegment FindServerVariable(string serverVariable, Microsoft.AspNetCore.Rewrite.Internal.ParserContext context, Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.UriMatchPart uriMatchPart) { throw null; }
+        public static Microsoft.AspNetCore.Rewrite.Internal.PatternSegment FindServerVariable(string serverVariable, Microsoft.AspNetCore.Rewrite.Internal.ParserContext context, Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.UriMatchPart uriMatchPart, bool alwaysUseManagedServerVariables) { throw null; }
     }
     public partial class UriMatchCondition : Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.Condition
     {
@@ -462,7 +462,7 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
     public partial class UrlRewriteFileParser
     {
         public UrlRewriteFileParser() { }
-        public System.Collections.Generic.IList<Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.IISUrlRewriteRule> Parse(System.IO.TextReader reader) { throw null; }
+        public System.Collections.Generic.IList<Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite.IISUrlRewriteRule> Parse(System.IO.TextReader reader, bool alwaysUseManagedServerVariables) { throw null; }
     }
     public partial class UrlRewriteRuleBuilder
     {

src/Middleware/Rewrite/src/IISUrlRewriteOptionsExtensions.cs

@@ -1,8 +1,9 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
 using System.IO;
+using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite;
 using Microsoft.Extensions.FileProviders;
 
@@ -19,7 +20,8 @@ namespace Microsoft.AspNetCore.Rewrite
         /// <param name="options">The <see cref="RewriteOptions"/></param>
         /// <param name="fileProvider">The <see cref="IFileProvider"/> </param>
         /// <param name="filePath">The path to the file containing UrlRewrite rules.</param>
-        public static RewriteOptions AddIISUrlRewrite(this RewriteOptions options, IFileProvider fileProvider, string filePath)
+        /// <param name="alwaysUseManagedServerVariables">Server variables are by default sourced from the server if it supports the <see cref="IServerVariablesFeature"/> feature. Use <c>true</c> to disable that behavior</param>
+        public static RewriteOptions AddIISUrlRewrite(this RewriteOptions options, IFileProvider fileProvider, string filePath, bool alwaysUseManagedServerVariables = false)
         {
             if (options == null)
             {
@@ -35,7 +37,7 @@ namespace Microsoft.AspNetCore.Rewrite
 
             using (var stream = file.CreateReadStream())
             {
-                return AddIISUrlRewrite(options, new StreamReader(stream));
+                return AddIISUrlRewrite(options, new StreamReader(stream), alwaysUseManagedServerVariables);
             }
         }
 
@@ -44,7 +46,8 @@ namespace Microsoft.AspNetCore.Rewrite
         /// </summary>
         /// <param name="options">The <see cref="RewriteOptions"/></param>
         /// <param name="reader">The text reader stream.</param>
-        public static RewriteOptions AddIISUrlRewrite(this RewriteOptions options, TextReader reader)
+        /// <param name="alwaysUseManagedServerVariables">Server variables are by default sourced from the server if it supports the <see cref="IServerVariablesFeature"/> feature. Use <c>true</c> to disable that behavior</param>
+        public static RewriteOptions AddIISUrlRewrite(this RewriteOptions options, TextReader reader, bool alwaysUseManagedServerVariables = false)
         {
             if (options == null)
             {
@@ -56,7 +59,7 @@ namespace Microsoft.AspNetCore.Rewrite
                 throw new ArgumentException(nameof(reader));
             }
 
-            var rules = new UrlRewriteFileParser().Parse(reader);
+            var rules = new UrlRewriteFileParser().Parse(reader, alwaysUseManagedServerVariables);
 
             foreach (var rule in rules)
             {

src/Middleware/Rewrite/src/Internal/IISUrlRewrite/InputParser.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -14,14 +14,16 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
         private const char OpenBrace = '{';
         private const char CloseBrace = '}';
         private readonly IISRewriteMapCollection _rewriteMaps;
+        private readonly bool _alwaysUseManagedServerVariables;
 
         public InputParser()
         {
         }
 
-        public InputParser(IISRewriteMapCollection rewriteMaps)
+        public InputParser(IISRewriteMapCollection rewriteMaps, bool alwaysUseManagedServerVariables)
         {
             _rewriteMaps = rewriteMaps;
+            _alwaysUseManagedServerVariables = alwaysUseManagedServerVariables;
         }
 
         /// <summary>
@@ -98,7 +100,7 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
                 {
                     // This is just a server variable, so we do a lookup and verify the server variable exists.
                     parameter = context.Capture();
-                    results.Add(ServerVariables.FindServerVariable(parameter, context, uriMatchPart));
+                    results.Add(ServerVariables.FindServerVariable(parameter, context, uriMatchPart, _alwaysUseManagedServerVariables));
                     return;
                 }
                 else if (context.Current == Colon)

src/Middleware/Rewrite/src/Internal/IISUrlRewrite/ServerVariables.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -15,58 +15,89 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
         /// <param name="serverVariable">The server variable</param>
         /// <param name="context">The parser context which is utilized when an exception is thrown</param>
         /// <param name="uriMatchPart">Indicates whether the full URI or the path should be evaluated for URL segments</param>
+        /// <param name="alwaysUseManagedServerVariables">Determines whether server variables are sourced from the managed server</param>
         /// <exception cref="FormatException">Thrown when the server variable is unknown</exception>
         /// <returns>The matching <see cref="PatternSegment"/></returns>
-        public static PatternSegment FindServerVariable(string serverVariable, ParserContext context, UriMatchPart uriMatchPart)
+        public static PatternSegment FindServerVariable(string serverVariable, ParserContext context, UriMatchPart uriMatchPart, bool alwaysUseManagedServerVariables)
         {
+            Func<PatternSegment> managedVariableThunk = default;
+
             switch (serverVariable)
             {
                 // TODO Add all server variables here.
                 case "ALL_RAW":
-                    throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    managedVariableThunk = () => throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    break;
                 case "APP_POOL_ID":
-                    throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    managedVariableThunk = () => throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    break;
                 case "CONTENT_LENGTH":
-                    return new HeaderSegment(HeaderNames.ContentLength);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.ContentLength);
+                    break;
                 case "CONTENT_TYPE":
-                    return new HeaderSegment(HeaderNames.ContentType);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.ContentType);
+                    break;
                 case "HTTP_ACCEPT":
-                    return new HeaderSegment(HeaderNames.Accept);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.Accept);
+                    break;
                 case "HTTP_COOKIE":
-                    return new HeaderSegment(HeaderNames.Cookie);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.Cookie);
+                    break;
                 case "HTTP_HOST":
-                    return new HeaderSegment(HeaderNames.Host);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.Host);
+                    break;
                 case "HTTP_REFERER":
-                    return new HeaderSegment(HeaderNames.Referer);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.Referer);
+                    break;
                 case "HTTP_USER_AGENT":
-                    return new HeaderSegment(HeaderNames.UserAgent);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.UserAgent);
+                    break;
                 case "HTTP_CONNECTION":
-                    return new HeaderSegment(HeaderNames.Connection);
+                    managedVariableThunk = () => new HeaderSegment(HeaderNames.Connection);
+                    break;
                 case "HTTP_URL":
-                    return new UrlSegment(uriMatchPart);
+                    managedVariableThunk = () => new UrlSegment(uriMatchPart);
+                    break;
                 case "HTTPS":
-                    return new IsHttpsUrlSegment();
+                    managedVariableThunk = () => new IsHttpsUrlSegment();
+                    break;
                 case "LOCAL_ADDR":
-                    return new LocalAddressSegment();
+                    managedVariableThunk = () => new LocalAddressSegment();
+                    break;
                 case "HTTP_PROXY_CONNECTION":
-                    throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    managedVariableThunk = () => throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    break;
                 case "QUERY_STRING":
-                    return new QueryStringSegment();
+                    managedVariableThunk = () => new QueryStringSegment();
+                    break;
                 case "REMOTE_ADDR":
-                    return new RemoteAddressSegment();
+                    managedVariableThunk = () => new RemoteAddressSegment();
+                    break;
                 case "REMOTE_HOST":
-                    throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    managedVariableThunk = () => throw new NotSupportedException(Resources.FormatError_UnsupportedServerVariable(serverVariable));
+                    break;
                 case "REMOTE_PORT":
-                    return new RemotePortSegment();
+                    managedVariableThunk = () => new RemotePortSegment();
+                    break;
                 case "REQUEST_FILENAME":
-                    return new RequestFileNameSegment();
+                    managedVariableThunk = () => new RequestFileNameSegment();
+                    break;
                 case "REQUEST_METHOD":
-                    return new RequestMethodSegment();
+                    managedVariableThunk = () => new RequestMethodSegment();
+                    break;
                 case "REQUEST_URI":
-                    return new UrlSegment(uriMatchPart);
+                    managedVariableThunk = () => new UrlSegment(uriMatchPart);
+                    break;
                 default:
                     throw new FormatException(Resources.FormatError_InputParserUnrecognizedParameter(serverVariable, context.Index));
             }
+
+            if (alwaysUseManagedServerVariables)
+            {
+                return managedVariableThunk();
+            }
+
+            return new IISServerVariableSegment(serverVariable, managedVariableThunk);
         }
     }
 }

src/Middleware/Rewrite/src/Internal/IISUrlRewrite/UrlRewriteFileParser.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -20,7 +20,8 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
         /// Parse an IIS rewrite section into a list of <see cref="IISUrlRewriteRule"/>s.
         /// </summary>
         /// <param name="reader">The reader containing the rewrite XML</param>
-        public IList<IISUrlRewriteRule> Parse(TextReader reader)
+        /// <param name="alwaysUseManagedServerVariables">Determines whether server variables will be sourced from the managed server</param>
+        public IList<IISUrlRewriteRule> Parse(TextReader reader, bool alwaysUseManagedServerVariables)
         {
             var xmlDoc = XDocument.Load(reader, LoadOptions.SetLineInfo);
             var xmlRoot = xmlDoc.Descendants(RewriteTags.Rewrite).FirstOrDefault();
@@ -30,7 +31,7 @@ namespace Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite
                 return null;
             }
 
-            _inputParser = new InputParser(RewriteMapParser.Parse(xmlRoot));
+            _inputParser = new InputParser(RewriteMapParser.Parse(xmlRoot), alwaysUseManagedServerVariables);
 
             var result = new List<IISUrlRewriteRule>();
             ParseRules(xmlRoot.Descendants(RewriteTags.GlobalRules).FirstOrDefault(), result, global: true);

src/Middleware/Rewrite/src/Internal/PatternSegments/IISServerVariableSegment.cs

@@ -0,0 +1,25 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using Microsoft.AspNetCore.Server.IIS;
+
+namespace Microsoft.AspNetCore.Rewrite.Internal.PatternSegments
+{
+    internal class IISServerVariableSegment : PatternSegment
+    {
+        private readonly string _variableName;
+        private readonly Func<PatternSegment> _fallbackThunk;
+
+        public IISServerVariableSegment(string variableName, Func<PatternSegment> fallbackThunk)
+        {
+            _variableName = variableName;
+            _fallbackThunk = fallbackThunk;
+        }
+
+        public override string Evaluate(RewriteContext context, BackReferenceCollection ruleBackReferences, BackReferenceCollection conditionBackReferences)
+        {
+            return context.HttpContext.GetIISServerVariable(_variableName) ?? _fallbackThunk().Evaluate(context, ruleBackReferences, conditionBackReferences);
+        }
+    }
+}

src/Middleware/Rewrite/src/Microsoft.AspNetCore.Rewrite.csproj

@@ -15,6 +15,7 @@
   <ItemGroup>
     <Reference Include="Microsoft.AspNetCore.Hosting.Abstractions" />
     <Reference Include="Microsoft.AspNetCore.Http.Extensions" />
+    <Reference Include="Microsoft.AspNetCore.Server.IIS" />
     <Reference Include="Microsoft.Extensions.Configuration.Abstractions" />
     <Reference Include="Microsoft.Extensions.FileProviders.Abstractions" />
     <Reference Include="Microsoft.Extensions.Logging.Abstractions" />

src/Middleware/Rewrite/test/IISUrlRewrite/FileParserTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                 pattern: "article.aspx?id={R:1}&title={R:2}"));
 
             // act
-            var res = new UrlRewriteFileParser().Parse(new StringReader(xml));
+            var res = new UrlRewriteFileParser().Parse(new StringReader(xml), false);
 
             // assert
             AssertUrlRewriteRuleEquality(expected, res);
@@ -72,7 +72,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                 pattern: "article.aspx?id={R:1}&title={R:2}"));
 
             // act
-            var res = new UrlRewriteFileParser().Parse(new StringReader(xml));
+            var res = new UrlRewriteFileParser().Parse(new StringReader(xml), false);
 
             // assert
             AssertUrlRewriteRuleEquality(expected, res);
@@ -121,7 +121,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                 pattern: "article.aspx?id={R:1}&title={R:2}"));
 
             // act
-            var res = new UrlRewriteFileParser().Parse(new StringReader(xml));
+            var res = new UrlRewriteFileParser().Parse(new StringReader(xml), false);
 
             // assert
             AssertUrlRewriteRuleEquality(expected, res);
@@ -150,7 +150,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                         </rewrite>";
 
             // act
-            var rules = new UrlRewriteFileParser().Parse(new StringReader(xml));
+            var rules = new UrlRewriteFileParser().Parse(new StringReader(xml), false);
 
             // assert
             Assert.Equal(2, rules.Count);

src/Middleware/Rewrite/test/IISUrlRewrite/FormatExceptionHandlingTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -63,7 +63,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
         public void ThrowFormatExceptionWithCorrectMessage(string input, string expected)
         {
             // Arrange, Act, Assert
-            var ex = Assert.Throws<FormatException>(() => new UrlRewriteFileParser().Parse(new StringReader(input)));
+            var ex = Assert.Throws<FormatException>(() => new UrlRewriteFileParser().Parse(new StringReader(input), false));
             Assert.Equal(expected, ex.Message);
         }
     }

src/Middleware/Rewrite/test/IISUrlRewrite/InputParserTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -94,7 +94,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
         [Fact]
         public void Should_throw_FormatException_if_no_rewrite_maps_are_defined()
         {
-            Assert.Throws<FormatException>(() => new InputParser(null).ParseInputString("{apiMap:{R:1}}", UriMatchPart.Path));
+            Assert.Throws<FormatException>(() => new InputParser(null, false).ParseInputString("{apiMap:{R:1}}", UriMatchPart.Path));
         }
 
         [Fact]
@@ -104,7 +104,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
             const string undefinedMapName = "apiMap";
             var map = new IISRewriteMap(definedMapName);
             var maps = new IISRewriteMapCollection { map };
-            Assert.Throws<FormatException>(() => new InputParser(maps).ParseInputString($"{{{undefinedMapName}:{{R:1}}}}", UriMatchPart.Path));
+            Assert.Throws<FormatException>(() => new InputParser(maps, false).ParseInputString($"{{{undefinedMapName}:{{R:1}}}}", UriMatchPart.Path));
         }
 
         [Fact]
@@ -118,7 +118,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
             var maps = new IISRewriteMapCollection { map };
 
             var inputString = $"{{{expectedMapName}:{{R:1}}}}";
-            var pattern = new InputParser(maps).ParseInputString(inputString, UriMatchPart.Path);
+            var pattern = new InputParser(maps, false).ParseInputString(inputString, UriMatchPart.Path);
             Assert.Equal(1, pattern.PatternSegments.Count);
 
             var segment = pattern.PatternSegments.Single();

src/Middleware/Rewrite/test/IISUrlRewrite/InvalidUrlRewriteFormatExceptionHandlingTests.cs

@@ -211,7 +211,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
         public void ThrowInvalidUrlRewriteFormatExceptionWithCorrectMessage(string input, string expected)
         {
             // Arrange, Act, Assert
-            var ex = Assert.Throws<InvalidUrlRewriteFormatException>(() => new UrlRewriteFileParser().Parse(new StringReader(input)));
+            var ex = Assert.Throws<InvalidUrlRewriteFormatException>(() => new UrlRewriteFileParser().Parse(new StringReader(input), false));
             Assert.Equal(expected, ex.Message);
         }
     }

src/Middleware/Rewrite/test/IISUrlRewrite/ServerVariableTests.cs

@@ -1,14 +1,16 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System.Collections.Generic;
 using System.Text.RegularExpressions;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Rewrite.Internal;
 using Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite;
 using Microsoft.Net.Http.Headers;
 using Xunit;
 
-namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
+namespace Microsoft.AspNetCore.Rewrite.Tests.IISUrlRewrite
 {
     public class ServerVariableTests
     {
@@ -32,13 +34,105 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
         {
             // Arrange and Act
             var testParserContext = new ParserContext("test");
-            var serverVar = ServerVariables.FindServerVariable(variable, testParserContext, uriMatchPart);
+            var serverVar = ServerVariables.FindServerVariable(variable, testParserContext, uriMatchPart, true);
-            var lookup = serverVar.Evaluate(CreateTestHttpContext(), CreateTestRuleMatch().BackReferences, CreateTestCondMatch().BackReferences);
+            var lookup = serverVar.Evaluate(CreateTestRewriteContext(), CreateTestRuleMatch().BackReferences, CreateTestCondMatch().BackReferences);
             // Assert
             Assert.Equal(expected, lookup);
         }
 
-        private RewriteContext CreateTestHttpContext()
+        [Theory]
+        [InlineData("CONTENT_LENGTH", "20", UriMatchPart.Path)]
+        [InlineData("CONTENT_TYPE", "text/xml", UriMatchPart.Path)]
+        [InlineData("HTTP_ACCEPT", "other-accept", UriMatchPart.Path)]
+        [InlineData("HTTP_COOKIE", "other-cookie", UriMatchPart.Path)]
+        [InlineData("HTTP_HOST", "otherexample.com", UriMatchPart.Path)]
+        [InlineData("HTTP_REFERER", "other-referer", UriMatchPart.Path)]
+        [InlineData("HTTP_USER_AGENT", "other-useragent", UriMatchPart.Path)]
+        [InlineData("HTTP_CONNECTION", "other-connection", UriMatchPart.Path)]
+        [InlineData("HTTP_URL", "http://otherexample.com/other-foo?bar=2", UriMatchPart.Full)]
+        [InlineData("HTTP_URL", "http://otherexample.com/other-foo?bar=2", UriMatchPart.Path)]
+        [InlineData("QUERY_STRING", "bar=2", UriMatchPart.Path)]
+        [InlineData("REQUEST_FILENAME", "/other-foo", UriMatchPart.Path)]
+        [InlineData("REQUEST_URI", "/other-foo", UriMatchPart.Path)]
+        [InlineData("REQUEST_URI", "/other-foo", UriMatchPart.Full)]
+        [InlineData("REQUEST_METHOD", "POST", UriMatchPart.Full)]
+        public void CheckServerVariableFeatureHasPrecedenceWhenEnabled(string variable, string expected, UriMatchPart uriMatchPart)
+        {
+            // Arrange and Act
+            var testParserContext = new ParserContext("test");
+            var serverVar = ServerVariables.FindServerVariable(variable, testParserContext, uriMatchPart, false);
+            var httpContext = CreateTestHttpContext();
+            httpContext.Features.Set<IServerVariablesFeature>(new TestServerVariablesFeature(new Dictionary<string, string>
+            {
+                ["CONTENT_LENGTH"] = "20",
+                ["CONTENT_TYPE"] = "text/xml",
+                ["HTTP_ACCEPT"] = "other-accept",
+                ["HTTP_COOKIE"] = "other-cookie",
+                ["HTTP_HOST"] = "otherexample.com",
+                ["HTTP_REFERER"] = "other-referer",
+                ["HTTP_USER_AGENT"] = "other-useragent",
+                ["HTTP_CONNECTION"] = "other-connection",
+                ["HTTP_URL"] = "http://otherexample.com/other-foo?bar=2",
+                ["QUERY_STRING"] = "bar=2",
+                ["REQUEST_FILENAME"] = "/other-foo",
+                ["REQUEST_URI"] = "/other-foo",
+                ["REQUEST_METHOD"] = "POST"
+            }));
+
+            var rewriteContext = CreateTestRewriteContext(httpContext);
+            var lookup = serverVar.Evaluate(rewriteContext, CreateTestRuleMatch().BackReferences, CreateTestCondMatch().BackReferences);
+
+            // Assert
+            Assert.Equal(expected, lookup);
+        }
+
+        [Theory]
+        [InlineData("CONTENT_LENGTH", "10", UriMatchPart.Path)]
+        [InlineData("CONTENT_TYPE", "json", UriMatchPart.Path)]
+        [InlineData("HTTP_ACCEPT", "accept", UriMatchPart.Path)]
+        [InlineData("HTTP_COOKIE", "cookie", UriMatchPart.Path)]
+        [InlineData("HTTP_HOST", "example.com", UriMatchPart.Path)]
+        [InlineData("HTTP_REFERER", "referer", UriMatchPart.Path)]
+        [InlineData("HTTP_USER_AGENT", "useragent", UriMatchPart.Path)]
+        [InlineData("HTTP_CONNECTION", "connection", UriMatchPart.Path)]
+        [InlineData("HTTP_URL", "/foo", UriMatchPart.Path)]
+        [InlineData("HTTP_URL", "http://example.com/foo?bar=1", UriMatchPart.Full)]
+        [InlineData("QUERY_STRING", "bar=1", UriMatchPart.Path)]
+        [InlineData("REQUEST_FILENAME", "/foo", UriMatchPart.Path)]
+        [InlineData("REQUEST_URI", "/foo", UriMatchPart.Path)]
+        [InlineData("REQUEST_URI", "http://example.com/foo?bar=1", UriMatchPart.Full)]
+        [InlineData("REQUEST_METHOD", "GET", UriMatchPart.Full)]
+        public void CheckServerVariableFeatureIsntUsedWhenDisabled(string variable, string expected, UriMatchPart uriMatchPart)
+        {
+            // Arrange and Act
+            var testParserContext = new ParserContext("test");
+            var serverVar = ServerVariables.FindServerVariable(variable, testParserContext, uriMatchPart, true);
+            var httpContext = CreateTestHttpContext();
+            httpContext.Features.Set<IServerVariablesFeature>(new TestServerVariablesFeature(new Dictionary<string, string>
+            {
+                ["CONTENT_LENGTH"] = "20",
+                ["CONTENT_TYPE"] = "text/xml",
+                ["HTTP_ACCEPT"] = "other-accept",
+                ["HTTP_COOKIE"] = "other-cookie",
+                ["HTTP_HOST"] = "otherexample.com",
+                ["HTTP_REFERER"] = "other-referer",
+                ["HTTP_USER_AGENT"] = "other-useragent",
+                ["HTTP_CONNECTION"] = "other-connection",
+                ["HTTP_URL"] = "http://otherexample.com/other-foo?bar=2",
+                ["QUERY_STRING"] = "bar=2",
+                ["REQUEST_FILENAME"] = "/other-foo",
+                ["REQUEST_URI"] = "/other-foo",
+                ["REQUEST_METHOD"] = "POST"
+            }));
+
+            var rewriteContext = CreateTestRewriteContext(httpContext);
+            var lookup = serverVar.Evaluate(rewriteContext, CreateTestRuleMatch().BackReferences, CreateTestCondMatch().BackReferences);
+
+            // Assert
+            Assert.Equal(expected, lookup);
+        }
+
+        private HttpContext CreateTestHttpContext()
         {
             var context = new DefaultHttpContext();
             context.Request.Method = HttpMethods.Get;
@@ -53,7 +147,13 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
             context.Request.Headers[HeaderNames.Referer] = "referer";
             context.Request.Headers[HeaderNames.UserAgent] = "useragent";
             context.Request.Headers[HeaderNames.Connection] = "connection";
-            return new RewriteContext { HttpContext = context };
+
+            return context;
+        }
+
+        private RewriteContext CreateTestRewriteContext(HttpContext context = null)
+        {
+            return new RewriteContext { HttpContext = context ?? CreateTestHttpContext() };
         }
 
         private MatchResults CreateTestRuleMatch()
@@ -74,7 +174,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
             var context = new DefaultHttpContext();
             var rewriteContext = new RewriteContext { HttpContext = context };
             var testParserContext = new ParserContext("test");
-            var serverVar = ServerVariables.FindServerVariable("QUERY_STRING", testParserContext, UriMatchPart.Path);
+            var serverVar = ServerVariables.FindServerVariable("QUERY_STRING", testParserContext, UriMatchPart.Path, true);
             var lookup = serverVar.Evaluate(rewriteContext, CreateTestRuleMatch().BackReferences, CreateTestCondMatch().BackReferences);
 
             Assert.Equal(string.Empty, lookup);

src/Middleware/Rewrite/test/IISUrlRewrite/TestServerVariablesFeature.cs

@@ -0,0 +1,24 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Http.Features;
+
+namespace Microsoft.AspNetCore.Rewrite.Tests.IISUrlRewrite
+{
+    public class TestServerVariablesFeature : IServerVariablesFeature
+    {
+        private readonly Dictionary<string, string> _variables;
+
+        public TestServerVariablesFeature(Dictionary<string, string> variables)
+        {
+            _variables = variables;
+        }
+
+        public string this[string variableName]
+        {
+            get => _variables[variableName];
+            set => _variables[variableName] = value;
+        }
+    }
+}

src/Middleware/Rewrite/test/IISUrlRewrite/UrlRewriteApplicationTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.IO;
@@ -23,7 +23,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                 </rule>
                 </rules>
                 </rewrite>");
-            var rules = new UrlRewriteFileParser().Parse(xml);
+            var rules = new UrlRewriteFileParser().Parse(xml, false);
 
             Assert.Equal(1, rules.Count);
             var context = new RewriteContext { HttpContext = new DefaultHttpContext() };
@@ -42,7 +42,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                 </rule>
                 </rules>
                 </rewrite>");
-            var rules = new UrlRewriteFileParser().Parse(xml);
+            var rules = new UrlRewriteFileParser().Parse(xml, false);
 
             Assert.Equal(1, rules.Count);
             var context = new RewriteContext { HttpContext = new DefaultHttpContext() };
@@ -64,7 +64,7 @@ namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
                 </rule>
                 </rules>
                 </rewrite>");
-            var rules = new UrlRewriteFileParser().Parse(xml);
+            var rules = new UrlRewriteFileParser().Parse(xml, false);
 
             Assert.Equal(1, rules.Count);
             Assert.True(rules[0].Conditions.TrackAllCaptures);