Add proxy environment variables support for Windows

Changed the Windows version of SocketsHttpHandler so that it will honor the same environment variables similar to the Linux and OSX versions. If the environment variables are not set then it reverts back to the Windows WinInet/IE settings behavior. I added several kinds of unit and end-to-end tests to verify the SystemProxyInfo class is making the correct choice for all the different platforms regarding whether the HttpEnvironmentProxy or platform proxy (HttpSystemProxy for Windows and MacProxy for OSX) is used. Fixes #37187
davidsh · Apr 27, 2019 · 9ba8879 · 9ba8879
1 parent c5bb6ab
commit 9ba8879
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Showing 14 changed files with 284 additions and 62 deletions.
diff --git a/src/Common/tests/System/Net/Http/LoopbackProxyServer.cs b/src/Common/tests/System/Net/Http/LoopbackProxyServer.cs
@@ -27,10 +27,13 @@ public sealed class LoopbackProxyServer : IDisposable
         private const string ProxyAuthenticateNtlmHeader = "Proxy-Authenticate: NTLM\r\n";
         private const string ProxyAuthenticateNegotiateHeader = "Proxy-Authenticate: Negotiate\r\n";
 
+        private const string ViaHeaderValue = "HTTP/1.1 LoopbackProxyServer";
+
         private readonly Socket _listener;
         private readonly Uri _uri;
         private readonly AuthenticationSchemes _authSchemes;
         private readonly bool _connectionCloseAfter407;
+        private readonly bool _addViaRequestHeader;
         private readonly ManualResetEvent _serverStopped;
         private readonly List<ReceivedRequest> _requests;
         private int _connections;
@@ -50,6 +53,7 @@ private LoopbackProxyServer(Options options)
             _uri = new Uri($"http://{ep.Address}:{ep.Port}/");
             _authSchemes = options.AuthenticationSchemes;
             _connectionCloseAfter407 = options.ConnectionCloseAfter407;
+            _addViaRequestHeader = options.AddViaRequestHeader;
             _serverStopped = new ManualResetEvent(false);
 
             _requests = new List<ReceivedRequest>();
@@ -170,8 +174,15 @@ private async Task<bool> ProcessRequest(StreamReader reader, StreamWriter writer
                     requestMessage.Headers.Add(header.Key, header.Value);
                 }
             }
+
+            // Add 'Via' header.
+            if (_addViaRequestHeader)
+            {
+                requestMessage.Headers.Add("Via", ViaHeaderValue);
+            }
 
-            using (HttpClient outboundClient = new HttpClient())
+            var handler = new HttpClientHandler() { UseProxy = false };
+            using (HttpClient outboundClient = new HttpClient(handler))
             using (HttpResponseMessage response =
                 await outboundClient.SendAsync(requestMessage))
             {
@@ -303,7 +314,9 @@ public void Dispose()
                 _disposed = true;
             }
         }
-
+
+        public string ViaHeader => ViaHeaderValue;
+
         public class ReceivedRequest
         {
             public string RequestLine { get; set; }
@@ -315,6 +328,7 @@ public class Options
         {
             public AuthenticationSchemes AuthenticationSchemes { get; set; } = AuthenticationSchemes.None;
             public bool ConnectionCloseAfter407 { get; set; } = false;
+            public bool AddViaRequestHeader { get; set; } = false;
         }        
     }
 }
diff --git a/src/System.Net.Http/src/System.Net.Http.csproj b/src/System.Net.Http/src/System.Net.Http.csproj
@@ -216,6 +216,7 @@
   <!-- SocketsHttpHandler platform parts -->
   <ItemGroup Condition=" '$(TargetsUnix)' == 'true' And '$(TargetGroup)' == 'netcoreapp'">
     <Compile Include="System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.cs" />
+    <Compile Include="System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Unix.cs" />
     <Compile Include="$(CommonPath)\System\Net\ContextAwareResult.Unix.cs">
       <Link>Common\System\Net\ContextAwareResult.Unix.cs</Link>
     </Compile>
@@ -301,6 +302,8 @@
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetsWindows)' == 'true' And '$(TargetGroup)' == 'netcoreapp'">
     <Compile Include="System\Net\Http\SocketsHttpHandler\SystemProxyInfo.Windows.cs" />
+    <Compile Include="System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.cs" />
+    <Compile Include="System\Net\Http\SocketsHttpHandler\HttpEnvironmentProxy.Windows.cs" />
     <Compile Include="System\Net\Http\SocketsHttpHandler\HttpSystemProxy.cs" />
     <Compile Include="$(CommonPath)\Interop\Windows\SChannel\Interop.SecPkgContext_ApplicationProtocol.cs">
       <Link>Common\Interop\Windows\SChannel\Interop.SecPkgContext_ApplicationProtocol.cs</Link>

diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpEnvironmentProxy.Unix.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpEnvironmentProxy.Unix.cs
@@ -0,0 +1,55 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Net.Http
+{
+    internal sealed partial class HttpEnvironmentProxy : IWebProxy
+    {
+        public static bool TryCreate(out IWebProxy proxy)
+        {
+            // Get environment variables. Protocol specific take precedence over
+            // general all_*, lower case variable has precedence over upper case.
+            // Note that curl uses HTTPS_PROXY but not HTTP_PROXY.
+
+            Uri httpProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpProxyLC));
+            if (httpProxy == null && Environment.GetEnvironmentVariable(EnvCGI) == null)
+            {
+                httpProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpProxyUC));
+            }
+
+            Uri httpsProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpsProxyLC)) ??
+                             GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpsProxyUC));
+
+            if (httpProxy == null || httpsProxy == null)
+            {
+                Uri allProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvAllProxyLC)) ??
+                                GetUriFromString(Environment.GetEnvironmentVariable(EnvAllProxyUC));
+
+                if (httpProxy == null)
+                {
+                    httpProxy = allProxy;
+                }
+
+                if (httpsProxy == null)
+                {
+                    httpsProxy = allProxy;
+                }
+            }
+
+            // Do not instantiate if nothing is set.
+            // Caller may pick some other proxy type.
+            if (httpProxy == null && httpsProxy == null)
+            {
+                proxy = null;
+                return false;
+            }
+
+            string noProxy = Environment.GetEnvironmentVariable(EnvNoProxyLC) ??
+                Environment.GetEnvironmentVariable(EnvNoProxyUC);
+            proxy = new HttpEnvironmentProxy(httpProxy, httpsProxy, noProxy);
+
+            return true;
+        }
+    }
+}
diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpEnvironmentProxy.Windows.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpEnvironmentProxy.Windows.cs
@@ -0,0 +1,51 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Net.Http
+{
+    internal sealed partial class HttpEnvironmentProxy : IWebProxy
+    {
+        public static bool TryCreate(out IWebProxy proxy)
+        {
+            // Get environment variables. Protocol specific take precedence over
+            // general all_*. On Windows, environment variables are case insensitive.
+
+            Uri httpProxy = null;
+            if (Environment.GetEnvironmentVariable(EnvCGI) == null)
+            {
+                httpProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpProxyUC));
+            }
+
+            Uri httpsProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpsProxyUC));
+
+            if (httpProxy == null || httpsProxy == null)
+            {
+                Uri allProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvAllProxyUC));
+
+                if (httpProxy == null)
+                {
+                    httpProxy = allProxy;
+                }
+
+                if (httpsProxy == null)
+                {
+                    httpsProxy = allProxy;
+                }
+            }
+
+            // Do not instantiate if nothing is set.
+            // Caller may pick some other proxy type.
+            if (httpProxy == null && httpsProxy == null)
+            {
+                proxy = null;
+                return false;
+            }
+
+            string noProxy = Environment.GetEnvironmentVariable(EnvNoProxyUC);
+            proxy = new HttpEnvironmentProxy(httpProxy, httpsProxy, noProxy);
+
+            return true;
+        }
+    }
+}
diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpEnvironmentProxy.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpEnvironmentProxy.cs
@@ -88,7 +88,7 @@ private static NetworkCredential GetCredentialsFromString(string value)
         }
     }
 
-    internal sealed class HttpEnvironmentProxy : IWebProxy
+    internal sealed partial class HttpEnvironmentProxy : IWebProxy
     {
         private const string EnvAllProxyUC = "ALL_PROXY";
         private const string EnvAllProxyLC = "all_proxy";
@@ -105,51 +105,6 @@ internal sealed class HttpEnvironmentProxy : IWebProxy
         private string[] _bypass = null;// list of domains not to proxy
         private ICredentials _credentials;
 
-        public static bool TryCreate(out IWebProxy proxy)
-        {
-            // Get environmental variables. Protocol specific take precedence over
-            // general all_*, lower case variable has precedence over upper case.
-            // Note that curl uses HTTPS_PROXY but not HTTP_PROXY.
-
-            Uri httpProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpProxyLC));
-            if (httpProxy == null && Environment.GetEnvironmentVariable(EnvCGI) == null)
-            {
-                httpProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpProxyUC));
-            }
-
-            Uri httpsProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpsProxyLC)) ??
-                             GetUriFromString(Environment.GetEnvironmentVariable(EnvHttpsProxyUC));
-
-            if (httpProxy == null || httpsProxy == null)
-            {
-                Uri allProxy = GetUriFromString(Environment.GetEnvironmentVariable(EnvAllProxyLC)) ??
-                                GetUriFromString(Environment.GetEnvironmentVariable(EnvAllProxyUC));
-
-                if (httpProxy == null)
-                {
-                    httpProxy = allProxy;
-                }
-                if (httpsProxy == null)
-                {
-                    httpsProxy = allProxy;
-                }
-            }
-
-            // Do not instantiate if nothing is set.
-            // Caller may pick some other proxy type.
-            if (httpProxy == null && httpsProxy == null)
-            {
-                proxy = null;
-                return false;
-            }
-
-            string noProxy = Environment.GetEnvironmentVariable(EnvNoProxyLC) ??
-                Environment.GetEnvironmentVariable(EnvNoProxyUC);
-            proxy = new HttpEnvironmentProxy(httpProxy, httpsProxy, noProxy);
-
-            return true;
-        }
-
         private HttpEnvironmentProxy(Uri httpProxy, Uri httpsProxy, string bypassList)
         {
             _httpProxyUri = httpProxy;

diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SystemProxyInfo.OSX.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SystemProxyInfo.OSX.cs
@@ -6,7 +6,7 @@ namespace System.Net.Http
 {
     internal static class SystemProxyInfo
     {
-        // On Unix we get default proxy configuration from environment variables
+        // On OSX we get default proxy configuration from either environment variables or the OSX system proxy.
         public static IWebProxy ConstructSystemProxy()
         {
             return HttpEnvironmentProxy.TryCreate(out IWebProxy proxy) ? proxy : new MacProxy();

diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SystemProxyInfo.Unix.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SystemProxyInfo.Unix.cs
@@ -6,11 +6,10 @@ namespace System.Net.Http
 {
     internal static class SystemProxyInfo
     {
-        // On Unix we get default proxy configuration from environment variables
+        // On Unix we get default proxy configuration from environment variables.
         public static IWebProxy ConstructSystemProxy()
         {
             return HttpEnvironmentProxy.TryCreate(out IWebProxy proxy) ? proxy : null;
         }
     }
 }
-
diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SystemProxyInfo.Windows.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SystemProxyInfo.Windows.cs
@@ -6,10 +6,17 @@ namespace System.Net.Http
 {
     internal static class SystemProxyInfo
     {
+        // On Windows we get default proxy configuration from either environment variables or the Windows system proxy.
         public static IWebProxy ConstructSystemProxy()
         {
-            return HttpSystemProxy.TryCreate(out IWebProxy proxy) ? proxy : null;
+            if (HttpEnvironmentProxy.TryCreate(out IWebProxy proxy))
+            {
+                return proxy;
+            }
+
+            HttpSystemProxy.TryCreate(out proxy);
+
+            return proxy;
         }
     }
 }
-
diff --git a/src/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Proxy.cs b/src/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Proxy.cs
@@ -7,6 +7,9 @@
 using System.Text;
 using System.Threading.Tasks;
 
+using Microsoft.DotNet.XUnitExtensions;
+using Microsoft.DotNet.RemoteExecutor;
+
 using Xunit;
 using Xunit.Abstractions;
 
@@ -101,6 +104,35 @@ public abstract class HttpClientHandler_Proxy_Test : HttpClientHandlerTestBase
             }
         }
 
+        [OuterLoop("Uses external server")]
+        [ConditionalFact]
+        public void Proxy_UseEnvironmentVariableToSetSystemProxy_RequestGoesThruProxy()
+        {
+            if (!UseSocketsHttpHandler)
+            {
+                throw new SkipTestException("Test needs SocketsHttpHandler");
+            }
+
+            RemoteExecutor.Invoke(async useSocketsHttpHandlerString =>
+            {
+                var options = new LoopbackProxyServer.Options { AddViaRequestHeader = true };
+                using (LoopbackProxyServer proxyServer = LoopbackProxyServer.Create(options))
+                {
+                    Environment.SetEnvironmentVariable("http_proxy", proxyServer.Uri.AbsoluteUri.ToString());
+
+                    using (HttpClient client = CreateHttpClient(useSocketsHttpHandlerString))
+                    using (HttpResponseMessage response = await client.GetAsync(Configuration.Http.RemoteEchoServer))
+                    {
+                        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+                        string body = await response.Content.ReadAsStringAsync();
+                        Assert.Contains(proxyServer.ViaHeader, body);
+                    }
+
+                    return RemoteExecutor.SuccessExitCode;
+                }
+            }, UseSocketsHttpHandler.ToString()).Dispose();
+        }
+
         [ActiveIssue(32809)]
         [OuterLoop("Uses external server")]
         [Theory]

diff --git a/src/System.Net.Http/tests/UnitTests/Configurations.props b/src/System.Net.Http/tests/UnitTests/Configurations.props
@@ -1,7 +1,9 @@
 <Project DefaultTargets="Build">
   <PropertyGroup>
     <BuildConfigurations>
-      netcoreapp;
+      netcoreapp-OSX;
+      netcoreapp-Unix;
+      netcoreapp-Windows_NT;
     </BuildConfigurations>
   </PropertyGroup>
 </Project>
diff --git a/src/System.Net.Http/tests/UnitTests/Fakes/MacProxy.cs b/src/System.Net.Http/tests/UnitTests/Fakes/MacProxy.cs
@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Net.Http
+{
+    internal sealed class MacProxy : IWebProxy
+    {
+        public ICredentials Credentials
+        {
+            get => throw NotImplemented.ByDesignWithMessage("Mac Proxy not implemented");
+            set => throw NotImplemented.ByDesignWithMessage("Mac Proxy not implemented");
+        }
+
+        public Uri GetProxy(Uri targetUri)
+        {
+            throw NotImplemented.ByDesignWithMessage("Mac Proxy not implemented");
+        }
+
+        public bool IsBypassed(Uri targetUri)
+        {
+            throw NotImplemented.ByDesignWithMessage("Mac Proxy not implemented");
+        }
+    }
+}