Provide runtime/framework info in gRPC C# user agent string (#25889)

* remove dead code (followup for #25717)

* add more details into grpc-csharp user agent string

* address review comments

src/csharp/Grpc.Core.Tests/Internal/UserAgentStringProviderTest.cs

@@ -0,0 +1,63 @@
+#region Copyright notice and license
+
+// Copyright 2021 The gRPC Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#endregion
+
+using System;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Internal.Tests
+{
+    public class UserAgentStringProviderTest
+    {
+        [Test]
+        public void BasicTest()
+        {
+            Assert.AreEqual("grpc-csharp/1.0 (.NET Framework 4.6.1; CLR 1.2.3.4; net45; x64)",
+                new UserAgentStringProvider("1.0", ".NET Framework 4.6.1", "1.2.3.4", "net45", CommonPlatformDetection.CpuArchitecture.X64).GrpcCsharpUserAgentString);
+            Assert.AreEqual("grpc-csharp/1.0 (CLR 1.2.3.4; net45; x64)",
+                new UserAgentStringProvider("1.0", null, "1.2.3.4", "net45", CommonPlatformDetection.CpuArchitecture.X64).GrpcCsharpUserAgentString);
+            Assert.AreEqual("grpc-csharp/1.0 (.NET Framework 4.6.1; net45; x64)",
+                new UserAgentStringProvider("1.0", ".NET Framework 4.6.1", null, "net45", CommonPlatformDetection.CpuArchitecture.X64).GrpcCsharpUserAgentString);
+            Assert.AreEqual("grpc-csharp/1.0 (.NET Framework 4.6.1; CLR 1.2.3.4; x64)",
+                new UserAgentStringProvider("1.0", ".NET Framework 4.6.1", "1.2.3.4", null, CommonPlatformDetection.CpuArchitecture.X64).GrpcCsharpUserAgentString);
+        }
+
+        [Test]
+        public void ArchitectureTest()
+        {
+            Assert.AreEqual("grpc-csharp/1.0 (.NET Framework 4.6.1; CLR 1.2.3.4; net45; arm64)",
+                new UserAgentStringProvider("1.0", ".NET Framework 4.6.1", "1.2.3.4", "net45", CommonPlatformDetection.CpuArchitecture.Arm64).GrpcCsharpUserAgentString);
+
+            // unknown architecture
+            Assert.AreEqual("grpc-csharp/1.0 (.NET Framework 4.6.1; CLR 1.2.3.4; net45)",
+                new UserAgentStringProvider("1.0", ".NET Framework 4.6.1", "1.2.3.4", "net45", CommonPlatformDetection.CpuArchitecture.Unknown).GrpcCsharpUserAgentString);
+        }
+
+        [Test]
+        public void FrameworkDescriptionTest()
+        {
+            Assert.AreEqual("grpc-csharp/1.0 (Mono 6.12.0.93; x64)",
+                new UserAgentStringProvider("1.0", "Mono 6.12.0.93 (2020-02/620cf538206 Tue Aug 25 14:04:52 EDT 2020)", null, null, CommonPlatformDetection.CpuArchitecture.X64).GrpcCsharpUserAgentString);
+
+            Assert.AreEqual("grpc-csharp/1.0 (x64)",
+                new UserAgentStringProvider("1.0", "(some invalid framework description)", null, null, CommonPlatformDetection.CpuArchitecture.X64).GrpcCsharpUserAgentString);
+        }
+    }
+}

src/csharp/Grpc.Core.Tests/UserAgentStringTest.cs

@@ -50,10 +50,10 @@ namespace Grpc.Core.Tests
             helper = new MockServiceHelper(Host);
             helper.UnaryHandler = new UnaryServerMethod<string, string>((request, context) =>
             {
-                var userAgentString = context.RequestHeaders.First(m => (m.Key == "user-agent")).Value;
+                var userAgentString = context.RequestHeaders.GetValue("user-agent");
                 var parts = userAgentString.Split(new [] {' '}, 2);
-                Assert.AreEqual(string.Format("grpc-csharp/{0}", VersionInfo.CurrentVersion), parts[0]);
-                Assert.IsTrue(parts[1].StartsWith("grpc-c/"));
+                Assert.AreEqual($"grpc-csharp/{VersionInfo.CurrentVersion}", parts[0]);
+                Assert.That(parts[1], Does.Match(@"\(.*\) grpc-c/.*"));
                 return Task.FromResult("PASS");
             });
 
@@ -71,9 +71,10 @@ namespace Grpc.Core.Tests
                 channelOptions: new[] { new ChannelOption(ChannelOptions.PrimaryUserAgentString, "XYZ") });
             helper.UnaryHandler = new UnaryServerMethod<string, string>((request, context) =>
             {
-                var userAgentString = context.RequestHeaders.First(m => (m.Key == "user-agent")).Value;
+                var userAgentString = context.RequestHeaders.GetValue("user-agent");
                 var parts = userAgentString.Split(new[] { ' ' }, 3);
                 Assert.AreEqual("XYZ", parts[0]);
+                Assert.AreEqual($"grpc-csharp/{VersionInfo.CurrentVersion}", parts[1]);
                 return Task.FromResult("PASS");
             });
 

src/csharp/Grpc.Core/Channel.cs

@@ -318,8 +318,7 @@ namespace Grpc.Core
                 userAgentString = option.StringValue + " ";
             };
 
-            // TODO(jtattermusch): it would be useful to also provide .NET/mono version.
-            userAgentString += string.Format("grpc-csharp/{0}", VersionInfo.CurrentVersion);
+            userAgentString += UserAgentStringProvider.DefaultInstance.GrpcCsharpUserAgentString;
 
             options[ChannelOptions.PrimaryUserAgentString] = new ChannelOption(key, userAgentString);
         }

src/csharp/Grpc.Core/Internal/PlatformApis.cs

@@ -47,6 +47,8 @@ namespace Grpc.Core.Internal
         static readonly bool isMono;
         static readonly bool isNet5OrHigher;
         static readonly bool isNetCore;
+        static readonly string frameworkDescription;
+        static readonly string clrVersion;
         static readonly string unityApplicationPlatform;
         static readonly bool isXamarin;
         static readonly bool isXamarinIOS;
@@ -72,6 +74,8 @@ namespace Grpc.Core.Internal
             isNet5OrHigher = false;
             isNetCore = false;
 #endif
+            frameworkDescription = TryGetFrameworkDescription();
+            clrVersion = TryGetClrVersion();
 
             // Detect mono runtime
             isMono = Type.GetType("Mono.Runtime") != null;
@@ -124,6 +128,18 @@ namespace Grpc.Core.Internal
         /// </summary>
         public static bool IsNet5OrHigher => isNet5OrHigher;
 
+        /// <summary>
+        /// Contains <c>RuntimeInformation.FrameworkDescription</c> if the property is available on current TFM.
+        /// <c>null</c> otherwise.
+        /// </summary>
+        public static string FrameworkDescription => frameworkDescription;
+
+        /// <summary>
+        /// Contains the version of common language runtime obtained from <c>Environment.Version</c>
+        /// if the property is available on current TFM. <c>null</c> otherwise.
+        /// </summary>
+        public static string ClrVersion => clrVersion;
+
         /// <summary>
         /// true if running on .NET Core (CoreCLR) or NET 5+, false otherwise.
         /// </summary>
@@ -184,31 +200,54 @@ namespace Grpc.Core.Internal
             }
         }
 
-        [DllImport("libc")]
-        static extern int uname(IntPtr buf);
+        /// <summary>
+        /// Returns description of the framework this process is running on.
+        /// Value is based on <c>RuntimeInformation.FrameworkDescription</c>.
+        /// </summary>
+        static string TryGetFrameworkDescription()
+        {
+#if NETSTANDARD
+            return RuntimeInformation.FrameworkDescription;
+#else
+            // on full .NET framework we are targeting net45, and the property is only available starting from .NET Framework 4.7.1+
+            // try obtaining the value by reflection since we might be running on a newer framework even though we're targeting
+            // an older one.
+            var runtimeInformationClass = Type.GetType("System.Runtime.InteropServices.RuntimeInformation");
+            var frameworkDescriptionProperty = runtimeInformationClass?.GetTypeInfo().GetProperty("FrameworkDescription", BindingFlags.Static | BindingFlags.Public);
+            return frameworkDescriptionProperty?.GetValue(null)?.ToString();
+#endif
+        }
 
-        static string GetUname()
+        /// <summary>
+        /// Returns version of the common language runtime this process is running on.
+        /// Value is based on <c>Environment.Version</c>.
+        /// </summary>
+        static string TryGetClrVersion()
         {
-            var buffer = Marshal.AllocHGlobal(8192);
-            try
-            {
-                if (uname(buffer) == 0)
-                {
-                    return Marshal.PtrToStringAnsi(buffer);
-                }
-                return string.Empty;
-            }
-            catch
-            {
-                return string.Empty;
-            }
-            finally
-            {
-                if (buffer != IntPtr.Zero)
-                {
-                    Marshal.FreeHGlobal(buffer);
-                }
-            }
+#if NETSTANDARD1_5
+            return null;
+#else
+            return Environment.Version.ToString();
+#endif
+        }
+
+        /// <summary>
+        /// Returns the TFM of the Grpc.Core assembly.
+        /// </summary>
+        public static string GetGrpcCoreTargetFrameworkMoniker()
+        {
+#if NETSTANDARD1_5
+            return "netstandard1.5";
+#elif NETSTANDARD2_0
+            return "netstandard2.0";
+#elif NET45
+            return "net45";
+#else
+            // The TFM is determined at compile time.
+            // The is intentionally no "default" return clause here so that
+            // if the set of TFMs we build for changes and this method is not updated accordingly,
+            // it will result in compilation error.
+#endif
         }
     }
 }

src/csharp/Grpc.Core/Internal/UserAgentStringProvider.cs

@@ -0,0 +1,108 @@
+#region Copyright notice and license
+
+// Copyright 2021 The gRPC Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#endregion
+
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+
+namespace Grpc.Core.Internal
+{
+    /// <summary>
+    /// Helps constructing the grpc-csharp component of the user agent string.
+    /// </summary>
+    internal class UserAgentStringProvider
+    {
+        static readonly UserAgentStringProvider defaultInstance;
+        readonly string userAgentString;
+
+        static UserAgentStringProvider()
+        {
+            defaultInstance = new UserAgentStringProvider(VersionInfo.CurrentVersion, PlatformApis.FrameworkDescription, PlatformApis.ClrVersion, PlatformApis.GetGrpcCoreTargetFrameworkMoniker(), PlatformApis.ProcessArchitecture);
+        }
+
+        public static UserAgentStringProvider DefaultInstance => defaultInstance;
+
+        public string GrpcCsharpUserAgentString => userAgentString;
+
+        public UserAgentStringProvider(string grpcCsharpVersion, string frameworkDescription, string clrVersion, string tfm, CommonPlatformDetection.CpuArchitecture arch)
+        {
+            var detailComponents = new List<string>();
+
+            string sanitizedFrameworkDescription = SanitizeFrameworkDescription(frameworkDescription);
+            if (sanitizedFrameworkDescription != null)
+            {
+                detailComponents.Add(sanitizedFrameworkDescription);
+            }
+
+            if (clrVersion != null)
+            {
+                detailComponents.Add($"CLR {clrVersion}");
+            }
+
+            if (tfm != null)
+            {
+                detailComponents.Add(tfm);
+            }
+
+            string architectureString = TryGetArchitectureString(arch);
+            if (architectureString != null)
+            {
+                detailComponents.Add(architectureString);
+            }
+
+            // TODO(jtattermusch): consider adding details about running under unity / xamarin etc.
+            var details = string.Join("; ", detailComponents);
+            userAgentString = $"grpc-csharp/{grpcCsharpVersion} ({details})";
+        }
+
+        static string TryGetArchitectureString(CommonPlatformDetection.CpuArchitecture arch)
+        {
+            if (arch == CommonPlatformDetection.CpuArchitecture.Unknown)
+            {
+                return null;
+            }
+            return arch.ToString().ToLowerInvariant();
+        }
+
+        static string SanitizeFrameworkDescription(string frameworkDescription)
+        {
+            if (frameworkDescription == null)
+            {
+                return null;
+            }
+
+            // Some platforms return more details in the FrameworkDescription string than we want.
+            // e.g. on mono, we will get something like "Mono 6.12.0.93 (2020-02/620cf538206 Tue Aug 25 14:04:52 EDT 2020)"
+            // For user agent string, we only want basic info on framework name and its version.
+            var parts = new List<string>(frameworkDescription.Split(' '));
+            
+            int i = 0;
+            for  (; i < parts.Count; i++)
+            {
+                var part = parts[i];
+                if (!Regex.IsMatch(part, @"^[-.,+@A-Za-z0-9]*$"))
+                {
+                    // stop once we find first part that's not framework name or version
+                    break;
+                }
+            }
+
+            var result = string.Join(" ", parts.GetRange(0, i));
+            return !string.IsNullOrEmpty(result) ? result : null;
+        }
+    }
+}

src/csharp/tests.json

@@ -17,6 +17,7 @@
     "Grpc.Core.Internal.Tests.SliceBufferSafeHandleTest",
     "Grpc.Core.Internal.Tests.SliceTest",
     "Grpc.Core.Internal.Tests.TimespecTest",
+    "Grpc.Core.Internal.Tests.UserAgentStringProviderTest",
     "Grpc.Core.Internal.Tests.WellKnownStringsTest",
     "Grpc.Core.Tests.AppDomainUnloadTest",
     "Grpc.Core.Tests.AuthContextTest",