优化dns服务

FastGithub.Dns/DnsHostedService.cs

@@ -0,0 +1,114 @@
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using System;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace FastGithub.Dns
+{
+    /// <summary>
+    /// dns后台服务
+    /// </summary>
+    sealed class DnsHostedService : BackgroundService
+    {
+        private readonly DnsServer dnsServer;
+        private readonly HostsFileValidator hostsValidator;
+        private readonly ILogger<DnsHostedService> logger;
+
+        /// <summary>
+        /// dns后台服务
+        /// </summary>
+        /// <param name="dnsServer"></param>
+        /// <param name="hostsValidator"></param>
+        /// <param name="options"></param>
+        /// <param name="logger"></param>
+        public DnsHostedService(
+            DnsServer dnsServer,
+            HostsFileValidator hostsValidator,
+            IOptionsMonitor<FastGithubOptions> options,
+            ILogger<DnsHostedService> logger)
+        {
+            this.dnsServer = dnsServer;
+            this.hostsValidator = hostsValidator;
+            this.logger = logger;
+
+            options.OnChange(opt =>
+            {
+                if (OperatingSystem.IsWindows())
+                {
+                    SystemDnsUtil.DnsFlushResolverCache();
+                }
+            });
+        }
+
+        /// <summary>
+        /// 启动dns
+        /// </summary>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        public override async Task StartAsync(CancellationToken cancellationToken)
+        {
+            this.dnsServer.Bind(IPAddress.Any, 53);
+            this.logger.LogInformation("DNS服务启动成功");
+
+            if (OperatingSystem.IsWindows())
+            {
+                try
+                {
+                    SystemDnsUtil.DnsSetPrimitive(IPAddress.Loopback);
+                    SystemDnsUtil.DnsFlushResolverCache();
+                    this.logger.LogInformation($"设置为本机主DNS成功");
+                }
+                catch (Exception ex)
+                {
+                    this.logger.LogWarning($"设置为本机主DNS失败：{ex.Message}");
+                }
+            }
+            else
+            {
+                this.logger.LogWarning("平台不支持自动设置DNS，请手动设置网卡的主DNS为127.0.0.1");
+            }
+
+            await this.hostsValidator.ValidateAsync();
+            await base.StartAsync(cancellationToken);
+        }
+
+        /// <summary>
+        /// dns后台
+        /// </summary>
+        /// <param name="stoppingToken"></param>
+        /// <returns></returns>
+        protected override Task ExecuteAsync(CancellationToken stoppingToken)
+        {
+            return this.dnsServer.ListenAsync(stoppingToken);
+        }
+
+        /// <summary>
+        /// 停止dns服务
+        /// </summary>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        public override Task StopAsync(CancellationToken cancellationToken)
+        {
+            this.dnsServer.Dispose();
+            this.logger.LogInformation("DNS服务已停止");
+
+            if (OperatingSystem.IsWindows())
+            {
+                try
+                {
+                    SystemDnsUtil.DnsFlushResolverCache();
+                    SystemDnsUtil.DnsRemovePrimitive(IPAddress.Loopback);
+                }
+                catch (Exception ex)
+                {
+                    this.logger.LogWarning($"恢复DNS记录失败：{ex.Message}");
+                }
+            }
+
+            return base.StopAsync(cancellationToken);
+        }
+    }
+}

FastGithub.Dns/DnsServer.cs

@@ -0,0 +1,111 @@
+using DNS.Protocol;
+using Microsoft.Extensions.Logging;
+using System;
+using System.Diagnostics;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace FastGithub.Dns
+{
+    /// <summary>
+    /// dns服务器
+    /// </summary>
+    sealed class DnsServer : IDisposable
+    {
+        private readonly RequestResolver requestResolver;
+        private readonly ILogger<DnsServer> logger;
+        private readonly Socket socket = new(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
+        private readonly byte[] buffer = new byte[ushort.MaxValue];
+
+        /// <summary>
+        /// dns服务器
+        /// </summary>
+        /// <param name="requestResolver"></param>
+        /// <param name="logger"></param>
+        public DnsServer(
+            RequestResolver requestResolver,
+            ILogger<DnsServer> logger)
+        {
+            this.requestResolver = requestResolver;
+            this.logger = logger;
+        }
+
+        /// <summary>
+        /// 绑定地址和端口
+        /// </summary>
+        /// <param name="address"></param>
+        /// <param name="port"></param> 
+        /// <returns></returns>
+        public void Bind(IPAddress address, int port)
+        {
+            if (OperatingSystem.IsWindows() && UdpTable.TryGetOwnerProcessId(port, out var processId))
+            {
+                Process.GetProcessById(processId).Kill();
+            }
+
+            if (OperatingSystem.IsWindows())
+            {
+                const int SIO_UDP_CONNRESET = unchecked((int)0x9800000C);
+                this.socket.IOControl(SIO_UDP_CONNRESET, new byte[4], new byte[4]);
+            }
+
+            this.socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
+            this.socket.Bind(new IPEndPoint(address, port));
+        }
+
+        /// <summary>
+        /// 监听dns请求
+        /// </summary>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        public async Task ListenAsync(CancellationToken cancellationToken)
+        {
+            var remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
+            while (cancellationToken.IsCancellationRequested == false)
+            {
+                try
+                {
+                    var result = await this.socket.ReceiveFromAsync(this.buffer, SocketFlags.None, remoteEndPoint);
+                    var datas = new byte[result.ReceivedBytes];
+                    this.buffer.AsSpan(0, datas.Length).CopyTo(datas);
+                    this.HandleRequestAsync(datas, result.RemoteEndPoint, cancellationToken);
+                }
+                catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
+                {
+                    break;
+                }
+            }
+        }
+
+        /// <summary>
+        /// 处理dns请求
+        /// </summary>
+        /// <param name="datas"></param>
+        /// <param name="remoteEndPoint"></param>
+        /// <param name="cancellationToken"></param>
+        private async void HandleRequestAsync(byte[] datas, EndPoint remoteEndPoint, CancellationToken cancellationToken)
+        {
+            try
+            {
+                var request = Request.FromArray(datas);
+                var remoteEndPointRequest = new RemoteEndPointRequest(request, remoteEndPoint);
+                var response = await this.requestResolver.Resolve(remoteEndPointRequest, cancellationToken);
+                await this.socket.SendToAsync(response.ToArray(), SocketFlags.None, remoteEndPoint);
+            }
+            catch (Exception ex)
+            {
+                this.logger.LogTrace($"处理DNS异常：{ex.Message}");
+            }
+        }
+
+        /// <summary>
+        /// 释放资源
+        /// </summary>
+        public void Dispose()
+        {
+            this.socket.Dispose();
+        }
+    }
+}

FastGithub.Dns/DnsServerHostedService.cs

@@ -1,203 +0,0 @@
-using DNS.Protocol;
-using Microsoft.Extensions.Hosting;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
-using System;
-using System.Diagnostics;
-using System.Net;
-using System.Net.Sockets;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace FastGithub.Dns
-{
-    /// <summary>
-    /// dns后台服务
-    /// </summary>
-    sealed class DnsServerHostedService : BackgroundService
-    {
-        private readonly RequestResolver requestResolver;
-        private readonly HostsFileValidator hostsValidator;
-        private readonly ILogger<DnsServerHostedService> logger;
-
-        private readonly Socket socket = new(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
-        private readonly byte[] buffer = new byte[ushort.MaxValue];
-
-
-        /// <summary>
-        /// dns后台服务
-        /// </summary>
-        /// <param name="requestResolver"></param>
-        /// <param name="hostsValidator"></param>
-        /// <param name="options"></param>
-        /// <param name="logger"></param>
-        public DnsServerHostedService(
-            RequestResolver requestResolver,
-            HostsFileValidator hostsValidator,
-            IOptionsMonitor<FastGithubOptions> options,
-            ILogger<DnsServerHostedService> logger)
-        {
-            this.requestResolver = requestResolver;
-            this.hostsValidator = hostsValidator;
-            this.logger = logger;
-
-            options.OnChange(opt =>
-            {
-                if (OperatingSystem.IsWindows())
-                {
-                    SystemDnsUtil.DnsFlushResolverCache();
-                }
-            });
-        }
-
-        /// <summary>
-        /// 启动dns
-        /// </summary>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
-        public override async Task StartAsync(CancellationToken cancellationToken)
-        {
-            await this.BindAsync(cancellationToken);
-            this.logger.LogInformation("DNS服务启动成功");
-
-            this.SetAsPrimitiveNameServer();
-            await this.hostsValidator.ValidateAsync();
-
-            await base.StartAsync(cancellationToken);
-        }
-
-        /// <summary>
-        /// 尝试多次绑定
-        /// </summary>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
-        private async Task BindAsync(CancellationToken cancellationToken)
-        {
-            const int DNS_PORT = 53;
-            if (OperatingSystem.IsWindows() && UdpTable.TryGetOwnerProcessId(DNS_PORT, out var processId))
-            {
-                Process.GetProcessById(processId).Kill();
-            }
-
-            var localEndPoint = new IPEndPoint(IPAddress.Any, DNS_PORT);
-            var delay = TimeSpan.FromMilliseconds(100d);
-            for (var i = 10; i >= 0; i--)
-            {
-                try
-                {
-                    this.socket.Bind(localEndPoint);
-                    break;
-                }
-                catch (Exception)
-                {
-                    if (i == 0)
-                    {
-                        throw new FastGithubException($"无法监听{localEndPoint}，udp端口已被其它程序占用");
-                    }
-                    await Task.Delay(delay, cancellationToken);
-                }
-            }
-
-            if (OperatingSystem.IsWindows())
-            {
-                const int SIO_UDP_CONNRESET = unchecked((int)0x9800000C);
-                this.socket.IOControl(SIO_UDP_CONNRESET, new byte[4], new byte[4]);
-            }
-        }
-
-        /// <summary>
-        /// 设置自身为主dns
-        /// </summary>
-        private void SetAsPrimitiveNameServer()
-        {
-            if (OperatingSystem.IsWindows())
-            {
-                try
-                {
-                    SystemDnsUtil.DnsSetPrimitive(IPAddress.Loopback);
-                    SystemDnsUtil.DnsFlushResolverCache();
-                    this.logger.LogInformation($"设置为本机主DNS成功");
-                }
-                catch (Exception ex)
-                {
-                    this.logger.LogWarning($"设置为本机主DNS失败：{ex.Message}");
-                }
-            }
-            else
-            {
-                this.logger.LogWarning("平台不支持自动设置DNS，请手动设置网卡的主DNS为127.0.0.1");
-            }
-        }
-
-        /// <summary>
-        /// dns后台
-        /// </summary>
-        /// <param name="stoppingToken"></param>
-        /// <returns></returns>
-        protected async override Task ExecuteAsync(CancellationToken stoppingToken)
-        {
-            var remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
-            while (stoppingToken.IsCancellationRequested == false)
-            {
-                try
-                {
-                    var result = await this.socket.ReceiveFromAsync(this.buffer, SocketFlags.None, remoteEndPoint);
-                    var datas = new byte[result.ReceivedBytes];
-                    this.buffer.AsSpan(0, datas.Length).CopyTo(datas);
-                    this.HandleRequestAsync(datas, result.RemoteEndPoint, stoppingToken);
-                }
-                catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
-                {
-                    break;
-                }
-            }
-        }
-
-        /// <summary>
-        /// 处理dns请求
-        /// </summary>
-        /// <param name="datas"></param>
-        /// <param name="remoteEndPoint"></param>
-        /// <param name="cancellationToken"></param>
-        private async void HandleRequestAsync(byte[] datas, EndPoint remoteEndPoint, CancellationToken cancellationToken)
-        {
-            try
-            {
-                var request = Request.FromArray(datas);
-                var remoteEndPointRequest = new RemoteEndPointRequest(request, remoteEndPoint);
-                var response = await this.requestResolver.Resolve(remoteEndPointRequest, cancellationToken);
-                await this.socket.SendToAsync(response.ToArray(), SocketFlags.None, remoteEndPoint);
-            }
-            catch (Exception ex)
-            {
-                this.logger.LogTrace($"处理DNS异常：{ex.Message}");
-            }
-        }
-
-        /// <summary>
-        /// 停止dns服务
-        /// </summary>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
-        public override Task StopAsync(CancellationToken cancellationToken)
-        {
-            this.socket.Dispose();
-            this.logger.LogInformation("DNS服务已停止");
-
-            if (OperatingSystem.IsWindows())
-            {
-                try
-                {
-                    SystemDnsUtil.DnsFlushResolverCache();
-                    SystemDnsUtil.DnsRemovePrimitive(IPAddress.Loopback);
-                }
-                catch (Exception ex)
-                {
-                    this.logger.LogWarning($"恢复DNS记录失败：{ex.Message}");
-                }
-            }
-
-            return base.StopAsync(cancellationToken);
-        }
-    }
-}

FastGithub.Dns/DnsServiceCollectionExtensions.cs

@@ -6,7 +6,7 @@ namespace FastGithub
     /// <summary>
     /// dns服务注册扩展
     /// </summary>
-    public static class DnsServerServiceCollectionExtensions
+    public static class DnsServiceCollectionExtensions
     {
         /// <summary>
         /// 注册dns服务
@@ -17,8 +17,9 @@ namespace FastGithub
         {
             return services
                 .AddSingleton<RequestResolver>()
+                .AddSingleton<DnsServer>()
                 .AddSingleton<HostsFileValidator>()
-                .AddHostedService<DnsServerHostedService>();
+                .AddHostedService<DnsHostedService>();
         }
     }
 }