CSHARP-1875: Steer clear of code that needs ntdll.dll

And making sure it compile/works on .NET Standard / Core as well

Author: MarLoe

src/MongoDB.Driver.Core/Core/Connections/ClientDocumentHelper.cs

@@ -16,6 +16,7 @@
 using System;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Text.RegularExpressions;
 using MongoDB.Bson;
 
 namespace MongoDB.Driver.Core.Connections
@@ -68,57 +69,119 @@ internal static BsonDocument CreateDriverDocument(string driverVersion)
         internal static BsonDocument CreateOSDocument()
         {
             string osType;
-            switch (Environment.OSVersion.Platform)
+            string architecture;
+            string osName;
+            string osVersion;
+
+#if NET45
+            if (Type.GetType("Mono.Runtime") != null)
+            {
+                Console.WriteLine("Hello Mono!!!");
+                switch (Environment.OSVersion.Platform)
+                {
+                    case PlatformID.Win32S:
+                    case PlatformID.Win32Windows:
+                    case PlatformID.Win32NT:
+                    case PlatformID.WinCE:
+                        osType = "Windows";
+                        break;
+
+                    case PlatformID.Unix:
+                        osType = "Linux";
+                        break;
+
+                    case PlatformID.Xbox:
+                        osType = "XBox";
+                        break;
+
+                    case PlatformID.MacOSX:
+                        osType = "macOS";
+                        break;
+
+                    default:
+                        osType = "Unknown";
+                        break;
+                }
+
+
+                PortableExecutableKinds peKind;
+                ImageFileMachine machine;
+                typeof(object).Module.GetPEKind(out peKind, out machine);
+                switch (machine)
+                {
+                    case ImageFileMachine.I386:
+                        architecture = "x86_32";
+                        break;
+                    case ImageFileMachine.IA64:
+                    case ImageFileMachine.AMD64:
+                        architecture = "x86_64";
+                        break;
+                    case ImageFileMachine.ARM:
+                        architecture = "arm" + (Environment.Is64BitProcess ? "64" : "");
+                        break;
+                    default:
+                        architecture = null;
+                        break;
+                }
+
+                osName = Environment.OSVersion.VersionString;
+
+                osVersion = Environment.OSVersion.Version.ToString();
+
+                return CreateOSDocument(osType, osName, architecture, osVersion);
+            }
+            else
+#endif
             {
-                case PlatformID.Win32S:
-                case PlatformID.Win32Windows:
-                case PlatformID.Win32NT:
-                case PlatformID.WinCE:
+                if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                {
                     osType = "Windows";
-                    break;
-
-                case PlatformID.Unix:
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                {
                     osType = "Linux";
-                    break;
-
-                case PlatformID.Xbox:
-                    osType = "XBox";
-                    break;
-
-                case PlatformID.MacOSX:
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+                {
                     osType = "macOS";
-                    break;
-
-                default:
-                    osType = "Unknown";
-                    break;
+                }
+                else
+                {
+                    osType = "unknown";
+                }
+
+                osName = RuntimeInformation.OSDescription.Trim();
+
+                switch (RuntimeInformation.ProcessArchitecture)
+                {
+                    case Architecture.Arm:
+                        architecture = "arm";
+                        break;
+                    case Architecture.Arm64:
+                        architecture = "arm64";
+                        break;
+                    case Architecture.X64:
+                        architecture = "x86_64";
+                        break;
+                    case Architecture.X86:
+                        architecture = "x86_32";
+                        break;
+                    default:
+                        architecture = null;
+                        break;
+                }
+
+                var match = Regex.Match(osName, @" (?<version>\d+\.\d[^ ]*)");
+                if (match.Success)
+                {
+                    osVersion = match.Groups["version"].Value;
+                }
+                else
+                {
+                    osVersion = null;
+                }
             }
 
-            string architecture;
-            PortableExecutableKinds peKind;
-            ImageFileMachine machine;
-            typeof(object).Module.GetPEKind(out peKind, out machine);
-            switch (machine)
-            {
-                case ImageFileMachine.I386:
-                    architecture = "x86_32";
-                    break;
-                case ImageFileMachine.IA64:
-                case ImageFileMachine.AMD64:
-                    architecture = "x86_64";
-                    break;
-                case ImageFileMachine.ARM:
-                    architecture = "arm" + (Environment.Is64BitProcess ? "64" : "");
-                    break;
-                default:
-                    architecture = null;
-                    break;
-            }
-
-            var osName = Environment.OSVersion.VersionString;
-
-            string osVersion = Environment.OSVersion.Version.ToString();
-
             return CreateOSDocument(osType, osName, architecture, osVersion);
         }
 
@@ -182,7 +245,7 @@ internal static BsonDocument RemoveOptionalFieldsUntilDocumentIsLessThan512Bytes
 
             return clientDocument;
         }
-        #endregion
+#endregion
 
     }
 }