Merge pull request #10 from richardschneider/peds

Privacy enabled DNS (PEDS)

Peds/App.config

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+    <configSections>
+        <sectionGroup name="common">
+            <section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging"/>
+        </sectionGroup>
+    </configSections>
+
+    <common>
+        <logging>
+            <factoryAdapter type="Common.Logging.Simple.ConsoleOutLoggerFactoryAdapter, Common.Logging">
+                <arg key="level" value="TRACE"/>
+                <arg key="showLogName" value="true"/>
+                <arg key="showDataTime" value="true"/>
+                <arg key="dateTimeFormat" value="yyyy/MM/dd HH:mm:ss:fff"/>
+            </factoryAdapter>
+        </logging>
+    </common>
+
+    <startup>
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2"/>
+    </startup>
+</configuration>

Peds/App.manifest

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="0.42.0.0" name="Peds"/>
+  <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>
+</assembly>

Peds/Issues.txt

@@ -0,0 +1,4 @@
+NIC uses WMI to manage the network adapters.  However, WMI does not support IPv6!
+See https://github.com/Noxwizard/dnscrypt-winclient/issues/4
+
+Should detect new adapter or adapter is active and set the dns server.

Peds/NetShell.cs

@@ -0,0 +1,102 @@
+using Common.Logging;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Net.Sockets;
+
+namespace Peds
+{
+    /// <summary>
+    ///   Builds a list of 'netsh' commands and then executes them
+    ///   all at once.
+    /// </summary>
+    class NetShell
+    {
+        static ILog log = LogManager.GetLogger("netsh");
+
+        StreamWriter commands;
+        string commandsFilename = Path.GetTempFileName();
+
+        /// <summary>
+        ///   Set the DNS servers for a network interface.
+        /// </summary>
+        /// <param name="nic">
+        ///   The network interface.
+        /// </param>
+        /// <param name="addresses">
+        ///   The <see cref="IPAddress"/> sequence for the DNS server. 
+        /// </param>
+        public void SetDnsServers(NetworkInterface nic, IEnumerable<IPAddress> addresses)
+        {
+            string qname = "\"" + nic.Name + "\"";
+
+            // IPv4
+            var addrs = addresses.Where(a => a.AddressFamily == AddressFamily.InterNetwork);
+            var primary = true;
+            foreach (var addr in addrs)
+            {
+                if (primary)
+                {
+                    Run($"interface ipv4 delete dns {qname} all");
+                }
+                Run($"interface ipv4 add dns {qname} {addr} validate=no");
+                primary = false;
+            }
+
+            // IPv6
+            addrs = addresses.Where(a => a.AddressFamily == AddressFamily.InterNetworkV6);
+            primary = true;
+            foreach (var addr in addrs)
+            {
+                if (primary)
+                {
+                    Run($"interface ipv6 delete dns {qname} all");
+                }
+                Run($"interface ipv6 add dns {qname} {addr} validate=no");
+                primary = false;
+            }
+        }
+
+        void Run(string args)
+        {
+            log.Debug(args);
+            if (commands == null)
+            {
+                commands = new StreamWriter(File.OpenWrite(commandsFilename));
+            }
+            commands.WriteLine(args);
+        }
+
+        /// <summary>
+        ///   Run the netsh commands.
+        /// </summary>
+        public void Run()
+        {
+            if (commands == null)
+                return;
+            commands.Close();
+            commands = null;
+
+            var args = $"-f \"{commandsFilename}\"";
+            var netsh = Process.Start(new ProcessStartInfo
+            {
+                FileName = "netsh",
+                Arguments = args,
+                Verb = "runas",
+                UseShellExecute = true,
+                WindowStyle = ProcessWindowStyle.Hidden
+            });
+            netsh.WaitForExit(1000);
+            File.Delete(commandsFilename);
+            if (netsh.ExitCode != 0)
+            {
+                throw new Exception($"netsh failed with exit code {netsh.ExitCode}.");
+            }
+        }
+
+    }
+}

Peds/Nic.cs

@@ -0,0 +1,62 @@
+using Common.Logging;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Management;
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Net.Sockets;
+
+namespace Peds
+{
+    /// <summary>
+    ///   Controls the network interfaces.
+    /// </summary>
+    /// <remarks>
+    ///   <b>Dispose</b> restores all networks to thier orignal values.
+    ///   <note>
+    ///   Requires elevated privileges.
+    ///   </note>
+    /// </remarks>
+    class Nic : IDisposable
+    {
+        static ILog log = LogManager.GetLogger(typeof(Nic));
+
+        Dictionary<NetworkInterface, IPAddressCollection> originalDnsServers = new Dictionary<NetworkInterface, IPAddressCollection>();
+
+        /// <summary>
+        ///   Set the DNS server addresses for all network interfaces.
+        /// </summary>
+        /// <param name="server">
+        ///   The sequence of <see cref="IPAddress"/> for the DNS server.
+        /// </param>
+        public void SetDnsServer(IEnumerable<IPAddress> addresses)
+        {
+            var netsh = new NetShell();
+            var nics = NetworkInterface
+                .GetAllNetworkInterfaces()
+                .Where(nic => nic.NetworkInterfaceType != NetworkInterfaceType.Loopback)
+                .Where(nic => 
+                    nic.Supports(NetworkInterfaceComponent.IPv4) ||
+                    nic.Supports(NetworkInterfaceComponent.IPv6));
+            foreach (var nic in nics)
+            {
+                var original = nic.GetIPProperties().DnsAddresses;
+                originalDnsServers[nic] = original;
+                netsh.SetDnsServers(nic, addresses);
+            }
+            netsh.Run();
+        }
+
+        public void Dispose()
+        {
+            var netsh = new NetShell();
+            foreach (var x in originalDnsServers)
+            {
+                netsh.SetDnsServers(x.Key, x.Value);
+            }
+            netsh.Run();
+        }
+
+    }
+}

Peds/Peds.csproj

@@ -0,0 +1,25 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net461</TargetFramework>
+    <!--ApplicationManifest>App.manifest</ApplicationManifest-->
+    <!-- developer build is always 0.2 -->
+    <AssemblyVersion>0.42</AssemblyVersion>
+    <Version>0.42</Version>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Common.Logging" Version="3.4.1" />
+    <PackageReference Include="System.Net.NetworkInformation" Version="4.3.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\src\Udns.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Reference Include="System.Management" />
+  </ItemGroup>
+
+</Project>

Peds/Program.cs

@@ -0,0 +1,81 @@
+using Makaretu.Dns;
+using System;
+using System.Net;
+using System.Threading.Tasks;
+
+namespace Peds
+{
+    partial class Program
+    {
+        TaskCompletionSource<int> done = new TaskCompletionSource<int>();
+        UdpServer server;
+        Nic nic;
+
+        static int Main(string[] args)
+        {
+            try
+            {
+                return new Program().RunAsync(args).Result;
+            }
+            catch (AggregateException e)
+            {
+                foreach (var ex in e.InnerExceptions)
+                {
+                    Console.Error.WriteLine(ex.Message);
+                }
+            }
+            catch (Exception e)
+            {
+                Console.Error.WriteLine(e.Message);
+            }
+            return -1;
+        }
+
+        async Task<int> RunAsync(string[] args)
+        {
+            Console.WriteLine("Hi!");
+
+            // TODO: Process args
+
+            Console.CancelKeyPress += (s, e) =>
+            {
+                Console.WriteLine("CTRL-C");
+                Stop();
+                e.Cancel = true;
+            };
+
+            Start();
+            return await done.Task;
+        }
+
+        void Start()
+        {
+            var resolver = new DotClient
+            {
+                ThrowResponseError = false
+            };
+
+            server = new UdpServer { Resolver = resolver };
+            server.Start();
+
+            nic = new Nic();
+            nic.SetDnsServer(server.Addresses);
+        }
+
+        void Stop()
+        {
+            if (nic != null)
+            {
+                nic.Dispose();
+                nic = null;
+            }
+            if (server != null)
+            {
+                server.Dispose();
+                server = null;
+            }
+
+            done.SetCanceled();
+        }
+    }
+}