刷新dns缓存

FastGithub.Dns/DnsOverUdpServer.cs

@@ -1,7 +1,6 @@
 using DNS.Protocol;
 using FastGithub.Configuration;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
 using System;
 using System.Net;
 using System.Net.Sockets;
@@ -29,13 +28,10 @@ namespace FastGithub.Dns
         /// <param name="logger"></param>
         public DnsOverUdpServer(
             RequestResolver requestResolver,
-            ILogger<DnsOverUdpServer> logger,
+            ILogger<DnsOverUdpServer> logger)
-            IOptionsMonitor<FastGithubOptions> options)
         {
             this.requestResolver = requestResolver;
             this.logger = logger; 
-
-            options.OnChange(opt => SystemDnsUtil.FlushResolverCache());
         }
 
         /// <summary>
@@ -64,7 +60,6 @@ namespace FastGithub.Dns
             try
             {
                 SystemDnsUtil.SetAsPrimitiveDns(); 
-                SystemDnsUtil.FlushResolverCache();
             }
             catch (Exception ex)
             {
@@ -141,10 +136,6 @@ namespace FastGithub.Dns
             {
                 this.logger.LogWarning(ex.Message);
             } 
-            finally
-            {
-                SystemDnsUtil.FlushResolverCache();
-            }
         }
     }
 }

FastGithub.Dns/DnsPoisoningServer.cs

@@ -6,6 +6,7 @@ using PacketDotNet;
 using System;
 using System.Linq;
 using System.Net;
+using System.Runtime.InteropServices;
 using System.Runtime.Versioning;
 using System.Threading;
 using WinDivertSharp;
@@ -22,6 +23,13 @@ namespace FastGithub.Dns
         private readonly ILogger<DnsPoisoningServer> logger;
         private readonly TimeSpan ttl = TimeSpan.FromSeconds(10d); 
 
+        /// <summary>
+        /// 刷新DNS缓存
+        /// </summary>
+        [SupportedOSPlatform("windows")]
+        [DllImport("dnsapi.dll", EntryPoint = "DnsFlushResolverCache", SetLastError = true)]
+        private static extern void DnsFlushResolverCache();  
+
         /// <summary>
         /// dns投毒后台服务
         /// </summary>
@@ -53,7 +61,7 @@ namespace FastGithub.Dns
             using var winDivertBuffer = new WinDivertBuffer(packetBuffer);
             var winDivertAddress = new WinDivertAddress();
 
-            SystemDnsUtil.FlushResolverCache();
+            DnsFlushResolverCache();
             while (cancellationToken.IsCancellationRequested == false)
             {
                 if (WinDivert.WinDivertRecv(handle, winDivertBuffer, ref winDivertAddress, ref packetLength))
@@ -73,6 +81,7 @@ namespace FastGithub.Dns
             }
 
             WinDivert.WinDivertClose(handle);
+            DnsFlushResolverCache();
         }
 
         /// <summary>

FastGithub.Dns/SystemDnsUtil.cs

@@ -1,12 +1,8 @@
 using FastGithub.Configuration;
 using System;
-using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using System.Net;
 using System.Net.NetworkInformation;
-using System.Runtime.InteropServices;
-using System.Runtime.Versioning;
 
 namespace FastGithub.Dns
 {
@@ -15,24 +11,6 @@ namespace FastGithub.Dns
     /// </summary> 
     static class SystemDnsUtil
     {
-        /// <summary>
-        /// 刷新DNS缓存
-        /// </summary>
-        [SupportedOSPlatform("windows")]
-        [DllImport("dnsapi.dll", EntryPoint = "DnsFlushResolverCache", SetLastError = true)]
-        private static extern void DnsFlushResolverCache();
-
-        /// <summary>
-        /// 刷新DNS缓存
-        /// </summary>
-        public static void FlushResolverCache()
-        {
-            if (OperatingSystem.IsWindows())
-            {
-                DnsFlushResolverCache();
-            }
-        }
-
         /// <summary>
         /// 设置为主dns
         /// </summary> 
@@ -50,12 +28,7 @@ namespace FastGithub.Dns
             if (firstRecord == null || LocalMachine.ContainsIPAddress(firstRecord) == false)
             {
                 var primitive = IPAddress.Loopback;
-                var nameServers = dnsAddresses.Prepend(primitive);
+                if (OperatingSystem.IsLinux())
-                if (OperatingSystem.IsWindows())
-                {
-                    SetNameServers(@interface, nameServers);
-                }
-                else if (OperatingSystem.IsLinux())
                 {
                     throw new FastGithubException($"不支持自动设置本机DNS，请手工添加{primitive}做为/etc/resolv.conf的第一条记录");
                 }
@@ -82,12 +55,7 @@ namespace FastGithub.Dns
             var firstRecord = dnsAddresses.FirstOrDefault();
             if (firstRecord != null && LocalMachine.ContainsIPAddress(firstRecord))
             {
-                var nameServers = dnsAddresses.Skip(1);
+                if (OperatingSystem.IsLinux())
-                if (OperatingSystem.IsWindows())
-                {
-                    SetNameServers(@interface, nameServers);
-                }
-                else if (OperatingSystem.IsLinux())
                 {
                     throw new FastGithubException($"不支持自动移除本机主DNS，请手工移除/etc/resolv.conf的第一条记录");
                 }
@@ -117,34 +85,5 @@ namespace FastGithub.Dns
                 .Where(item => item.GetIPProperties().UnicastAddresses.Any(a => a.Address.Equals(address)))
                 .FirstOrDefault();
         }
-
-
-        /// <summary>
-        /// 设置网口的dns
-        /// </summary>
-        /// <param name="interface"></param>
-        /// <param name="nameServers"></param>
-        [SupportedOSPlatform("windows")]
-        private static void SetNameServers(NetworkInterface @interface, IEnumerable<IPAddress> nameServers)
-        {
-            Netsh($@"interface ipv4 delete dns ""{@interface.Name}"" all");
-            foreach (var address in nameServers)
-            {
-                Netsh($@"interface ipv4 add dns ""{@interface.Name}"" {address} validate=no");
-            }
-
-            static void Netsh(string arguments)
-            {
-                var netsh = new ProcessStartInfo
-                {
-                    FileName = "netsh.exe",
-                    Arguments = arguments,
-                    CreateNoWindow = true,
-                    UseShellExecute = false,
-                    WindowStyle = ProcessWindowStyle.Hidden
-                };
-                Process.Start(netsh)?.WaitForExit();
-            }
-        }
     }
 }