embeddable-dll-service: add more robust example for .NET 5

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

14 files changed, 530 insertions, 110 deletions

diff --git a/embeddable-dll-service/csharp/DemoUI/MainWindow.Designer.cs b/embeddable-dll-service/csharp/DemoUI/MainWindow.Designer.cs
new file mode 100644
index 00000000..5fae35d3
--- /dev/null
+++ b/embeddable-dll-service/csharp/DemoUI/MainWindow.Designer.cs
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+namespace DemoUI
+{
+    partial class MainWindow
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.connectButton = new System.Windows.Forms.Button();
+            this.logBox = new System.Windows.Forms.TextBox();
+            this.SuspendLayout();
+            // 
+            // connectButton
+            // 
+            this.connectButton.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) 
+            | System.Windows.Forms.AnchorStyles.Right)));
+            this.connectButton.Location = new System.Drawing.Point(12, 12);
+            this.connectButton.Name = "connectButton";
+            this.connectButton.Size = new System.Drawing.Size(1137, 46);
+            this.connectButton.TabIndex = 5;
+            this.connectButton.Text = "&Connect";
+            this.connectButton.UseVisualStyleBackColor = true;
+            this.connectButton.Click += new System.EventHandler(this.connectButton_Click);
+            // 
+            // logBox
+            // 
+            this.logBox.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
+            | System.Windows.Forms.AnchorStyles.Left) 
+            | System.Windows.Forms.AnchorStyles.Right)));
+            this.logBox.Location = new System.Drawing.Point(12, 64);
+            this.logBox.Multiline = true;
+            this.logBox.Name = "logBox";
+            this.logBox.ReadOnly = true;
+            this.logBox.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
+            this.logBox.Size = new System.Drawing.Size(1137, 561);
+            this.logBox.TabIndex = 4;
+            this.logBox.TabStop = false;
+            // 
+            // MainWindow
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(13F, 32F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(1161, 637);
+            this.Controls.Add(this.logBox);
+            this.Controls.Add(this.connectButton);
+            this.Name = "MainWindow";
+            this.Text = "WireGuard Demo Client";
+            this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.MainWindow_FormClosing);
+            this.Load += new System.EventHandler(this.MainWindow_Load);
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+        private System.Windows.Forms.Button connectButton;
+        private System.Windows.Forms.TextBox logBox;
+    }
+}
+
diff --git a/embeddable-dll-service/csharp/DemoUI/MainWindow.cs b/embeddable-dll-service/csharp/DemoUI/MainWindow.cs
new file mode 100644
index 00000000..13499fcb
--- /dev/null
+++ b/embeddable-dll-service/csharp/DemoUI/MainWindow.cs
@@ -0,0 +1,213 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+using System;
+using System.Text;
+using System.Threading.Tasks;
+using System.IO;
+using System.Windows.Forms;
+using System.Threading;
+using System.IO.Pipes;
+using System.Diagnostics;
+using System.Net.Sockets;
+
+namespace DemoUI
+{
+    public partial class MainWindow : Form
+    {
+        private static readonly string userDirectory = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName);
+        private static readonly string configFile = Path.Combine(userDirectory, "demobox.conf");
+        private static readonly string logFile = Path.Combine(userDirectory, "log.bin");
+
+        private Tunnel.Ringlogger log;
+        private Thread logPrintingThread, transferUpdateThread;
+        private volatile bool threadsRunning;
+        private bool connected;
+
+        public MainWindow()
+        {
+            InitializeComponent();
+            Application.ApplicationExit += Application_ApplicationExit;
+
+            try { File.Delete(logFile); } catch { }
+            log = new Tunnel.Ringlogger(logFile, "GUI");
+            logPrintingThread = new Thread(new ThreadStart(tailLog));
+            transferUpdateThread = new Thread(new ThreadStart(tailTransfer));
+        }
+
+        private void tailLog()
+        {
+            var cursor = Tunnel.Ringlogger.CursorAll;
+            while (threadsRunning)
+            {
+                var lines = log.FollowFromCursor(ref cursor);
+                foreach (var line in lines)
+                    logBox.Invoke(new Action<string>(logBox.AppendText), new object[] { line + "\r\n" });
+                try
+                {
+                    Thread.Sleep(300);
+                }
+                catch
+                {
+                    break;
+                }
+            }
+        }
+
+        private void tailTransfer()
+        {
+            NamedPipeClientStream stream = null;
+            try
+            {
+                while (threadsRunning)
+                {
+                    while (threadsRunning)
+                    {
+                        try
+                        {
+                            stream = Tunnel.Service.GetPipe(configFile);
+                            stream.Connect();
+                            break;
+                        }
+                        catch { }
+                        Thread.Sleep(1000);
+                    }
+
+                    var reader = new StreamReader(stream);
+                    stream.Write(Encoding.UTF8.GetBytes("get=1\n\n"));
+                    ulong rx = 0, tx = 0;
+                    while (threadsRunning)
+                    {
+                        var line = reader.ReadLine();
+                        if (line == null)
+                            break;
+                        line = line.Trim();
+                        if (line.Length == 0)
+                            break;
+                        if (line.StartsWith("rx_bytes="))
+                            rx += ulong.Parse(line.Substring(9));
+                        else if (line.StartsWith("tx_bytes="))
+                            tx += ulong.Parse(line.Substring(9));
+                    }
+                    Invoke(new Action<ulong, ulong>(updateTransferTitle), new object[] { rx, tx });
+                    stream.Close();
+                    Thread.Sleep(1000);
+                }
+            }
+            catch { }
+            finally
+            {
+                if (stream != null && stream.IsConnected)
+                    stream.Close();
+            }
+        }
+
+        private void Application_ApplicationExit(object sender, EventArgs e)
+        {
+            Tunnel.Service.Remove(configFile, true);
+            try { File.Delete(logFile); } catch { }
+            try { File.Delete(configFile); } catch { }
+        }
+
+        private void MainWindow_Load(object sender, EventArgs e)
+        {
+            threadsRunning = true;
+            logPrintingThread.Start();
+            transferUpdateThread.Start();
+        }
+
+        private void MainWindow_FormClosing(object sender, FormClosingEventArgs e)
+        {
+            threadsRunning = false;
+            logPrintingThread.Interrupt();
+            transferUpdateThread.Interrupt();
+            try { logPrintingThread.Join(); } catch { }
+            try { transferUpdateThread.Join(); } catch { }
+        }
+
+        private static string formatBytes(ulong bytes)
+        {
+            decimal d = bytes;
+            string selectedUnit = null;
+            foreach (string unit in new string[] { "B", "KiB", "MiB", "GiB", "TiB" })
+            {
+                selectedUnit = unit;
+                if (d < 1024)
+                    break;
+                d /= 1024;
+            }
+            return string.Format("{0:0.##} {1}", d, selectedUnit);
+        }
+
+        private void updateTransferTitle(ulong rx, ulong tx)
+        {
+            var titleBase = Text;
+            var idx = titleBase.IndexOf(" - ");
+            if (idx != -1)
+                titleBase = titleBase.Substring(0, idx);
+            if (rx == 0 && tx == 0)
+                Text = titleBase;
+            else
+                Text = string.Format("{0} - rx: {1}, tx: {2}", titleBase, formatBytes(rx), formatBytes(tx));
+        }
+
+        private async Task<string> generateNewConfig()
+        {
+            log.Write("Generating keys");
+            var keys = Tunnel.Keypair.Generate();
+            log.Write("Exchanging keys with demo server");
+            var client = new TcpClient();
+            await client.ConnectAsync("demo.wireguard.com", 42912);
+            var stream = client.GetStream();
+            var reader = new StreamReader(stream, Encoding.UTF8);
+            var pubKeyBytes = Encoding.UTF8.GetBytes(keys.Public + "\n");
+            await stream.WriteAsync(pubKeyBytes, 0, pubKeyBytes.Length);
+            await stream.FlushAsync();
+            var ret = (await reader.ReadLineAsync()).Split(':');
+            client.Close();
+            var status = ret.Length >= 1 ? ret[0] : "";
+            var serverPubkey = ret.Length >= 2 ? ret[1] : "";
+            var serverPort = ret.Length >= 3 ? ret[2] : "";
+            var internalIP = ret.Length >= 4 ? ret[3] : "";
+            if (status != "OK")
+                throw new InvalidOperationException(string.Format("Server status is {0}", status));
+            return string.Format("[Interface]\nPrivateKey = {0}\nAddress = {1}/24\nDNS = 8.8.8.8, 8.8.4.4\n\n[Peer]\nPublicKey = {2}\nEndpoint = demo.wireguard.com:{3}\nAllowedIPs = 0.0.0.0/0\n", keys.Private, internalIP, serverPubkey, serverPort);
+        }
+
+        private async void connectButton_Click(object sender, EventArgs e)
+        {
+            if (connected)
+            {
+                connectButton.Enabled = false;
+                await Task.Run(() =>
+                {
+                    Tunnel.Service.Remove(configFile, true);
+                    try { File.Delete(configFile); } catch { }
+                });
+                updateTransferTitle(0, 0);
+                connectButton.Text = "&Connect";
+                connectButton.Enabled = true;
+                connected = false;
+                return;
+            }
+
+            connectButton.Enabled = false;
+            try
+            {
+                var config = await generateNewConfig();
+                await File.WriteAllBytesAsync(configFile, Encoding.UTF8.GetBytes(config));
+                await Task.Run(() => Tunnel.Service.Add(configFile, true));
+                connected = true;
+                connectButton.Text = "&Disconnect";
+            }
+            catch (Exception ex)
+            {
+                log.Write(ex.Message);
+                try { File.Delete(configFile); } catch { }
+            }
+            connectButton.Enabled = true;
+        }
+    }
+}
diff --git a/embeddable-dll-service/csharp/DemoUI/MainWindow.resx b/embeddable-dll-service/csharp/DemoUI/MainWindow.resx
new file mode 100644
index 00000000..f298a7be
--- /dev/null
+++ b/embeddable-dll-service/csharp/DemoUI/MainWindow.resx
@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>
\ No newline at end of file
diff --git a/embeddable-dll-service/csharp/DemoUI/Program.cs b/embeddable-dll-service/csharp/DemoUI/Program.cs
new file mode 100644
index 00000000..8c420973
--- /dev/null
+++ b/embeddable-dll-service/csharp/DemoUI/Program.cs
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+using System;
+using System.Threading;
+using System.Diagnostics;
+using System.Windows.Forms;
+
+namespace DemoUI
+{
+    static class Program
+    {
+        [STAThread]
+        static void Main(string[] args)
+        {
+            if (args.Length == 3 && args[0] == "/service")
+            {
+                var t = new Thread(() =>
+                {
+                    try
+                    {
+                        var currentProcess = Process.GetCurrentProcess();
+                        var uiProcess = Process.GetProcessById(int.Parse(args[2]));
+                        if (uiProcess.MainModule.FileName != currentProcess.MainModule.FileName)
+                            return;
+                        uiProcess.WaitForExit();
+                        Tunnel.Service.Remove(args[1], false);
+                    }
+                    catch { }
+                });
+                t.Start();
+                Tunnel.Service.Run(args[1]);
+                t.Interrupt();
+                return;
+            }
+            Application.SetHighDpiMode(HighDpiMode.SystemAware);
+            Application.EnableVisualStyles();
+            Application.SetCompatibleTextRenderingDefault(false);
+            Application.Run(new MainWindow());
+        }
+    }
+}
diff --git a/embeddable-dll-service/csharp/DemoUI/app.manifest b/embeddable-dll-service/csharp/DemoUI/app.manifest
new file mode 100644
index 00000000..616ab5b9
--- /dev/null
+++ b/embeddable-dll-service/csharp/DemoUI/app.manifest
@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="demo-client"/>
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
+    <security>
+      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
+        <requestedExecutionLevel level="requireAdministrator" uiAccess="false" />
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- Windows 7 -->
+      <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />
+
+      <!-- Windows 8 -->
+      <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />
+
+      <!-- Windows 8.1 -->
+      <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />
+
+      <!-- Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+
+    </application>
+  </compatibility>
+
+  <application xmlns="urn:schemas-microsoft-com:asm.v3">
+    <windowsSettings>
+      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware>
+    </windowsSettings>
+  </application>
+
+  <dependency>
+    <dependentAssembly>
+      <assemblyIdentity
+          type="win32"
+          name="Microsoft.Windows.Common-Controls"
+          version="6.0.0.0"
+          processorArchitecture="*"
+          publicKeyToken="6595b64144ccf1df"
+          language="*"
+        />
+    </dependentAssembly>
+  </dependency>
+
+</assembly>
diff --git a/embeddable-dll-service/csharp/Program.cs b/embeddable-dll-service/csharp/Program.cs
deleted file mode 100644
index dfefc3ec..00000000
--- a/embeddable-dll-service/csharp/Program.cs
+++ /dev/null
@@ -1,92 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019-2020 WireGuard LLC. All Rights Reserved.
- */
-
-using System;
-using System.Net.Sockets;
-using System.IO;
-using System.Text;
-using System.Diagnostics;
-using System.Threading;
-using System.Runtime.InteropServices;
-
-namespace Tunnel
-{
-    class Program
-    {
-
-        [DllImport("kernel32.dll")]
-        private static extern bool SetConsoleCtrlHandler(SetConsoleCtrlEventHandler handler, bool add);
-        private delegate bool SetConsoleCtrlEventHandler(UInt32 signal);
-
-        public static void Main(string[] args)
-        {
-            if (args.Length == 2 && args[0] == "/service")
-            {
-                Service.Run(args[1]);
-                return;
-            }
-
-            var baseDirectory = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName);
-            var configFile = Path.Combine(baseDirectory, "demobox.conf");
-            var logFile = Path.Combine(baseDirectory, "log.bin");
-
-            try { File.Delete(logFile); } catch { }
-            Ringlogger log = new Ringlogger(logFile, "GUI");
-
-            var logPrintingThread = new Thread(() =>
-            {
-                var cursor = Ringlogger.CursorAll;
-                while (Thread.CurrentThread.IsAlive)
-                {
-                    var lines = log.FollowFromCursor(ref cursor);
-                    foreach (var line in lines)
-                        Console.WriteLine(line);
-                    Thread.Sleep(300);
-                }
-            });
-            logPrintingThread.Start();
-
-            log.Write("Generating keys");
-            var keys = Keypair.Generate();
-            log.Write("Exchanging keys with demo server");
-            var client = new TcpClient("demo.wireguard.com", 42912);
-            var stream = client.GetStream();
-            var reader = new StreamReader(stream, Encoding.UTF8);
-            var pubKeyBytes = Encoding.UTF8.GetBytes(keys.Public + "\n");
-            stream.Write(pubKeyBytes, 0, pubKeyBytes.Length);
-            stream.Flush();
-            var ret = reader.ReadLine().Split(':');
-            client.Close();
-            var status = ret.Length >= 1 ? ret[0] : "";
-            var serverPubkey = ret.Length >= 2 ? ret[1] : "";
-            var serverPort = ret.Length >= 3 ? ret[2] : "";
-            var internalIP = ret.Length >= 4 ? ret[3] : "";
-
-            if (status != "OK")
-                throw new InvalidOperationException(String.Format("Server status is {0}", status));
-
-            SetConsoleCtrlHandler(delegate
-            {
-                Service.Remove(configFile);
-                Environment.Exit(0);
-                return true;
-            }, true);
-
-            log.Write("Writing config file to disk");
-            var configFileContents = String.Format("[Interface]\nPrivateKey = {0}\nAddress = {1}/24\nDNS = 8.8.8.8, 8.8.4.4\n\n[Peer]\nPublicKey = {2}\nEndpoint = demo.wireguard.com:{3}\nAllowedIPs = 0.0.0.0/0\n", keys.Private, internalIP, serverPubkey, serverPort);
-            File.WriteAllText(configFile, configFileContents);
-
-            try
-            {
-                Service.Add(configFile);
-                logPrintingThread.Join();
-            }
-            finally
-            {
-                Service.Remove(configFile);
-            }
-        }
-    }
-}
diff --git a/embeddable-dll-service/csharp/README.md b/embeddable-dll-service/csharp/README.md
new file mode 100644
index 00000000..071d15f6
--- /dev/null
+++ b/embeddable-dll-service/csharp/README.md
@@ -0,0 +1,15 @@
+# Example WireGuard Demo Client for Windows
+
+This is a simple client for demo.wireguard.com, which brings up WireGuard tunnels using the [embeddable-dll-service](https://git.zx2c4.com/wireguard-windows/about/embeddable-dll-service/README.md).
+
+## Building
+
+The code in this repository can be built in Visual Studio 2019 by opening the .sln and pressing build. However, it requires `tunnel.dll` to be present in the run directory. That can be built by:
+
+```batch
+> git clone https://git.zx2c4.com/wireguard-windows
+> cd wireguard-windows\embeddable-dll-service
+> .\build.bat
+```
+
+In addition, `tunnel.dll` requires `wintun.dll`, which can be downloaded from [wintun.net](https://www.wintun.net).
diff --git a/embeddable-dll-service/csharp/Keypair.cs b/embeddable-dll-service/csharp/TunnelDll/Keypair.cs
index 17a0a876..146d56e0 100644
--- a/embeddable-dll-service/csharp/Keypair.cs
+++ b/embeddable-dll-service/csharp/TunnelDll/Keypair.cs
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2019-2020 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
  */
 
 using System;
@@ -13,7 +13,7 @@ namespace Tunnel
         public readonly string Public;
         public readonly string Private;
 
-        private Keypair(string pub, string priv)
+        public Keypair(string pub, string priv)
         {
             Public = pub;
             Private = priv;
diff --git a/embeddable-dll-service/csharp/Ringlogger.cs b/embeddable-dll-service/csharp/TunnelDll/Ringlogger.cs
index 801eaa59..469927c1 100644
--- a/embeddable-dll-service/csharp/Ringlogger.cs
+++ b/embeddable-dll-service/csharp/TunnelDll/Ringlogger.cs
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2019-2020 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
  */
 
 using System;
diff --git a/embeddable-dll-service/csharp/Service.cs b/embeddable-dll-service/csharp/TunnelDll/Service.cs
index 0310d693..7f2c622e 100644
--- a/embeddable-dll-service/csharp/Service.cs
+++ b/embeddable-dll-service/csharp/TunnelDll/Service.cs
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2019-2020 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
  */
 
 using System;
@@ -9,15 +9,14 @@ using System.IO.Pipes;
 using System.Runtime.InteropServices;
 using System.ComponentModel;
 using System.Diagnostics;
-using System.Security.Principal;
 using System.Threading;
 
 namespace Tunnel
 {
     public class Service
     {
-        private const string LongName = "Example WireGuard Tunnel Client";
-        private const string Description = "A WireGuard tunnel created by example code.";
+        private const string LongName = "WireGuard Demo Box";
+        private const string Description = "Demonstration tunnel for testing WireGuard";
 
         [DllImport("tunnel.dll", EntryPoint = "WireGuardTunnelService", CallingConvention = CallingConvention.Cdecl)]
         public static extern bool Run([MarshalAs(UnmanagedType.LPWStr)] string configFile);
@@ -28,17 +27,13 @@ namespace Tunnel
             return new NamedPipeClientStream(pipepath);
         }
 
-        public static void Add(string configFile)
+        public static void Add(string configFile, bool ephemeral)
         {
             var tunnelName = Path.GetFileNameWithoutExtension(configFile);
             var shortName = String.Format("WireGuardTunnel${0}", tunnelName);
             var longName = String.Format("{0}: {1}", LongName, tunnelName);
             var exeName = Process.GetCurrentProcess().MainModule.FileName;
-            var pathAndArgs = String.Format("\"{0}\" /service \"{1}\"", exeName, configFile); //TODO: This is not the proper way to escape file args.
-
-            var accessControl = File.GetAccessControl(configFile); //TODO: TOCTOU!
-            accessControl.SetOwner(new NTAccount(Environment.UserDomainName, Environment.UserName));
-            File.SetAccessControl(configFile, accessControl);
+            var pathAndArgs = String.Format("\"{0}\" /service \"{1}\" {2}", exeName, configFile, Process.GetCurrentProcess().Id); //TODO: This is not the proper way to escape file args.
 
             var scm = Win32.OpenSCManager(null, null, Win32.ScmAccessRights.AllAccess);
             if (scm == IntPtr.Zero)
@@ -49,7 +44,7 @@ namespace Tunnel
                 if (service != IntPtr.Zero)
                 {
                     Win32.CloseServiceHandle(service);
-                    Remove(configFile);
+                    Remove(configFile, true);
                 }
                 service = Win32.CreateService(scm, shortName, longName, Win32.ServiceAccessRights.AllAccess, Win32.ServiceType.Win32OwnProcess, Win32.ServiceStartType.Demand, Win32.ServiceError.Normal, pathAndArgs, null, IntPtr.Zero, "Nsi\0TcpIp", null, null);
                 if (service == IntPtr.Zero)
@@ -66,6 +61,9 @@ namespace Tunnel
 
                     if (!Win32.StartService(service, 0, null))
                         throw new Win32Exception(Marshal.GetLastWin32Error());
+
+                    if (ephemeral && !Win32.DeleteService(service))
+                        throw new Win32Exception(Marshal.GetLastWin32Error());
                 }
                 finally
                 {
@@ -78,7 +76,7 @@ namespace Tunnel
             }
         }
 
-        public static void Remove(string configFile)
+        public static void Remove(string configFile, bool waitForStop)
         {
             var tunnelName = Path.GetFileNameWithoutExtension(configFile);
             var shortName = String.Format("WireGuardTunnel${0}", tunnelName);
@@ -99,10 +97,10 @@ namespace Tunnel
                     var serviceStatus = new Win32.ServiceStatus();
                     Win32.ControlService(service, Win32.ServiceControl.Stop, serviceStatus);
 
-                    for (int i = 0; i < 180 && Win32.QueryServiceStatus(service, serviceStatus) && serviceStatus.dwCurrentState != Win32.ServiceState.Stopped; ++i)
+                    for (int i = 0; waitForStop && i < 180 && Win32.QueryServiceStatus(service, serviceStatus) && serviceStatus.dwCurrentState != Win32.ServiceState.Stopped; ++i)
                         Thread.Sleep(1000);
 
-                    if (!Win32.DeleteService(service))
+                    if (!Win32.DeleteService(service) && Marshal.GetLastWin32Error() != 0x00000430)
                         throw new Win32Exception(Marshal.GetLastWin32Error());
                 }
                 finally
diff --git a/embeddable-dll-service/csharp/Win32.cs b/embeddable-dll-service/csharp/TunnelDll/Win32.cs
index 9d6808f3..d8447f7f 100644
--- a/embeddable-dll-service/csharp/Win32.cs
+++ b/embeddable-dll-service/csharp/TunnelDll/Win32.cs
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2019-2020 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
  */
 
 using System;
diff --git a/embeddable-dll-service/csharp/demo-client.csproj b/embeddable-dll-service/csharp/demo-client.csproj
new file mode 100644
index 00000000..00339ee2
--- /dev/null
+++ b/embeddable-dll-service/csharp/demo-client.csproj
@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net5.0-windows</TargetFramework>
+    <RootNamespace>DemoUI</RootNamespace>
+    <UseWindowsForms>true</UseWindowsForms>
+    <AssemblyName>demo-client</AssemblyName>
+    <Platforms>x64</Platforms>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <ApplicationManifest>DemoUI\app.manifest</ApplicationManifest>
+  </PropertyGroup>
+
+</Project>
diff --git a/embeddable-dll-service/csharp/demo-client.csproj.user b/embeddable-dll-service/csharp/demo-client.csproj.user
new file mode 100644
index 00000000..27d1a581
--- /dev/null
+++ b/embeddable-dll-service/csharp/demo-client.csproj.user
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="Current" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Compile Update="DemoUI\MainWindow.cs">
+      <SubType>Form</SubType>
+    </Compile>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/embeddable-dll-service/csharp/demo-client.sln b/embeddable-dll-service/csharp/demo-client.sln
new file mode 100644
index 00000000..a7d8b0ee
--- /dev/null
+++ b/embeddable-dll-service/csharp/demo-client.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30804.86
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "demo-client", "demo-client.csproj", "{AADC81E1-0294-483B-ABAE-63DBE82436E9}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|x64 = Debug|x64
+		Release|x64 = Release|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{AADC81E1-0294-483B-ABAE-63DBE82436E9}.Debug|x64.ActiveCfg = Debug|x64
+		{AADC81E1-0294-483B-ABAE-63DBE82436E9}.Debug|x64.Build.0 = Debug|x64
+		{AADC81E1-0294-483B-ABAE-63DBE82436E9}.Release|x64.ActiveCfg = Release|x64
+		{AADC81E1-0294-483B-ABAE-63DBE82436E9}.Release|x64.Build.0 = Release|x64
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {E410FD53-4E4A-4299-B6BD-CE91685DF7BE}
+	EndGlobalSection
+EndGlobal