[WIP] feat: DVC client example for devolutions-agent DVC server

.gitignore

@@ -4,4 +4,4 @@ obj/
 .vscode/
 .nupkg
 dependencies/
-package/
+package/

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "dotnet/now-proto"]
+	path = dotnet/now-proto
+	url = https://github.com/Devolutions/now-proto.git

dotnet/.gitignore

@@ -1,5 +1,6 @@
 bin/
 obj/
+.vs/
 *.csproj.user
 Directory.Build.props
 launchSettings.json

dotnet/AxInterop.MSTSCLib/AxInterop.MSTSCLib.csproj

@@ -10,6 +10,7 @@
     <Nullable>disable</Nullable>
     <GenerateAssemblyInfo>True</GenerateAssemblyInfo>
     <OutputPath>$(CMakeOutputPath)</OutputPath>
+    <TargetFrameworks>net8.0-windows</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

dotnet/CMakeLists.txt

@@ -8,5 +8,11 @@ include_external_msproject(Devolutions.MsRdpEx
 include_external_msproject(MsRdpEx_App
     "${CMAKE_CURRENT_SOURCE_DIR}/MsRdpEx_App/MsRdpEx_App.csproj")
 
+include_external_msproject(NowProto
+    "${CMAKE_CURRENT_SOURCE_DIR}/now-proto/nugets/Devolutions.NowProto/Devolutions.NowProto.csproj")
+
+include_external_msproject(NowClient
+    "${CMAKE_CURRENT_SOURCE_DIR}/now-proto/nugets/Devolutions.NowClient/Devolutions.NowClient.csproj")
+
 configure_file("${CMAKE_CURRENT_SOURCE_DIR}/Directory.Build.props.in"
     "${CMAKE_CURRENT_SOURCE_DIR}/Directory.Build.props" @ONLY)

dotnet/Devolutions.MsRdpEx/Devolutions.MsRdpEx.csproj

@@ -14,6 +14,7 @@
     <Nullable>enable</Nullable>
     <GenerateAssemblyInfo>True</GenerateAssemblyInfo>
     <SuppressDependenciesWhenPacking>True</SuppressDependenciesWhenPacking>
+    <TargetFrameworks>net8.0-windows</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
@@ -30,10 +31,8 @@
   </ItemGroup>
 
   <Target Name="PostBuild" AfterTargets="PostBuildEvent">
-    <Copy SourceFiles="$(CMakeOutputPath)/MsRdpEx.dll" DestinationFolder="$(OutputPath)"
-      OverwriteReadOnlyFiles="true" Condition="Exists('$(CMakeOutputPath)/MsRdpEx.dll')" />
-    <Copy SourceFiles="$(CMakeOutputPath)/MsRdpEx.pdb" DestinationFolder="$(OutputPath)"
-      OverwriteReadOnlyFiles="true" Condition="Exists('$(CMakeOutputPath)/MsRdpEx.pdb')" />
+    <Copy SourceFiles="$(CMakeOutputPath)/MsRdpEx.dll" DestinationFolder="$(OutputPath)" OverwriteReadOnlyFiles="true" Condition="Exists('$(CMakeOutputPath)/MsRdpEx.dll')" />
+    <Copy SourceFiles="$(CMakeOutputPath)/MsRdpEx.pdb" DestinationFolder="$(OutputPath)" OverwriteReadOnlyFiles="true" Condition="Exists('$(CMakeOutputPath)/MsRdpEx.pdb')" />
   </Target>
 
   <ItemGroup>

dotnet/MsRdpEx_App/DvcClientLib.cs

@@ -0,0 +1,192 @@
+/// <summary>
+/// Bindings for the native `dvc_client.dll` library (written in rust).
+/// </summary>
+
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace MsRdpEx_App
+{
+    internal class DvcClientFfiException : Exception
+    {
+        public DvcClientFfiException(string message) : base(message) {}
+    }
+
+    internal class DvcClientError : Exception
+    {
+        public DvcClientError(string message) : base(message) { }
+    }
+
+    internal enum DvcClientResponseKind
+    {
+        UpdateUi,
+        SendMessage,
+        Error,
+        None,
+    }
+
+    internal class DvcClientResponse
+    {
+        public DvcClientResponse(IntPtr result)
+        {
+            self = result;
+
+            var kind_ptr = DvcClientLib.dvcc_response_get_kind(self);
+            if (kind_ptr != IntPtr.Zero)
+            {
+                var kind_str = Marshal.PtrToStringAnsi(kind_ptr);
+                switch (kind_str)
+                {
+                    case "update_ui":
+                        kind = DvcClientResponseKind.UpdateUi;
+                        break;
+                    case "send_message":
+                        kind = DvcClientResponseKind.SendMessage;
+                        break;
+                    case "error":
+                        kind = DvcClientResponseKind.Error;
+
+                        var data = GetData();
+                        var message = Encoding.UTF8.GetString(data);
+                        throw new DvcClientError(message);
+                    default:
+                        throw new DvcClientFfiException("Unknown response kind");
+                }
+            }
+            else
+            {
+                kind = DvcClientResponseKind.None;
+            }
+        }
+
+        public DvcClientResponseKind Kind
+        {
+            get
+            {
+                return kind;
+            }
+        }
+
+        public string AsUiUpdate()
+        {
+            if (kind != DvcClientResponseKind.UpdateUi)
+            {
+                throw new DvcClientFfiException("Response is not an update_ui");
+            }
+
+            var data = GetData();
+            return Encoding.UTF8.GetString(data);
+        }
+
+        public IntPtr GetDataPtr()
+        {
+            if (kind == DvcClientResponseKind.None)
+            {
+                throw new DvcClientFfiException("Response has no data");
+            }
+
+            var data_ptr = DvcClientLib.dvcc_response_get_data(self);
+
+            if (data_ptr == IntPtr.Zero)
+            {
+                throw new DvcClientFfiException("Response data is NULL");
+            }
+
+            return data_ptr;
+        }
+
+        public uint GetDataLen()
+        {
+            var data_len = DvcClientLib.dvcc_response_get_data_len(self);
+
+            return (uint)data_len;
+        }
+
+        private byte[] GetData()
+        {
+            if (kind == DvcClientResponseKind.None)
+            {
+                throw new DvcClientFfiException("Response has no data");
+            }
+
+            var data_ptr = DvcClientLib.dvcc_response_get_data(self);
+            var data_len = DvcClientLib.dvcc_response_get_data_len(self);
+
+            if (data_ptr == IntPtr.Zero)
+            {
+                throw new DvcClientFfiException("Response data is NULL");
+            }
+
+            var data = new byte[data_len];
+            Marshal.Copy(data_ptr, data, 0, (int)data_len);
+            return data;
+        }
+
+        ~DvcClientResponse()
+        {
+            DvcClientLib.dvcc_response_destroy(self);
+        }
+
+        private IntPtr self;
+        private DvcClientResponseKind kind;
+    }
+
+    internal class DvcClientCtx
+    {
+        public DvcClientCtx()
+        {
+            self = DvcClientLib.dvcc_init();
+        }
+
+        public DvcClientResponse HandleUi(string request)
+        {
+            // String to byte[]
+            var req = Encoding.UTF8.GetBytes(request);
+
+            var result = DvcClientLib.dvcc_handle_ui(self, req, req.Length);
+            return new DvcClientResponse(result);
+        }
+
+        public DvcClientResponse HandleData(byte[] data)
+        {
+            var result = DvcClientLib.dvcc_handle_data(self, data, data.Length);
+            return new DvcClientResponse(result);
+        }
+
+        ~DvcClientCtx()
+        {
+            // TODO: IDisposable?
+            DvcClientLib.dvcc_destroy(self);
+        }
+
+        IntPtr self;
+    }
+
+    internal class DvcClientLib
+    {
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern IntPtr dvcc_init();
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void dvcc_destroy(IntPtr ctx);
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern IntPtr dvcc_handle_ui(IntPtr ctx, byte[] req, nint req_len);
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern IntPtr dvcc_handle_data(IntPtr ctx, byte[] data, nint data_len);
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void dvcc_response_destroy(IntPtr result);
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern IntPtr dvcc_response_get_kind(IntPtr result);
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern IntPtr dvcc_response_get_data(IntPtr result);
+
+        [DllImport("dvc_client.dll", CallingConvention = CallingConvention.Cdecl)]
+        public static extern nint dvcc_response_get_data_len(IntPtr result);
+    }
+}