增加快速扫描功能

Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
 	<PropertyGroup>
-		<Version>1.0.0</Version>
+		<Version>1.0.1</Version>
 		<Nullable>enable</Nullable>
 		<Description>github定制版的dns服务，解析github最优的ip</Description>
 		<Copyright>https://github.com/xljiulang/FastGithub</Copyright>

FastGithub.Scanner/GithubFullScanHostedService.cs

@@ -34,6 +34,7 @@ namespace FastGithub
         /// <returns></returns>
         protected override async Task ExecuteAsync(CancellationToken stoppingToken)
         {
+            await githubScanService.ScanFastAsync(stoppingToken);
             while (stoppingToken.IsCancellationRequested == false)
             {
                 await githubScanService.ScanAllAsync(stoppingToken);

FastGithub.Scanner/GithubLookupFacotry.cs

@@ -1,4 +1,5 @@
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using System.Collections.Generic;
 using System.Linq;
@@ -15,6 +16,7 @@ namespace FastGithub.Scanner
     {
         private readonly IEnumerable<IGithubLookupProvider> providers;
         private readonly IOptionsMonitor<GithubLookupFactoryOptions> options;
+        private readonly ILogger<GithubLookupFacotry> logger;
 
         /// <summary>
         /// 域名与ip关系工厂
@@ -23,10 +25,12 @@ namespace FastGithub.Scanner
         /// <param name="options"></param>
         public GithubLookupFacotry(
             IEnumerable<IGithubLookupProvider> providers,
-            IOptionsMonitor<GithubLookupFactoryOptions> options)
+            IOptionsMonitor<GithubLookupFactoryOptions> options,
+            ILogger<GithubLookupFacotry> logger)
         {
             this.providers = providers.OrderBy(item => item.Order);
             this.options = options;
+            this.logger = logger;
         }
 
         /// <summary>
@@ -35,6 +39,7 @@ namespace FastGithub.Scanner
         /// <returns></returns>
         public async Task<IEnumerable<DomainAddress>> LookupAsync(CancellationToken cancellationToken)
         {
+            this.logger.LogInformation($"开始查找各域名的ip..");
             var hashSet = new HashSet<DomainAddress>();
             var domains = this.options.CurrentValue.Domains;
 
@@ -46,6 +51,8 @@ namespace FastGithub.Scanner
                     hashSet.Add(item);
                 }
             }
+
+            this.logger.LogInformation($"查找到{hashSet.Count}条域名ip记录");
             return hashSet;
         }
     }

FastGithub.Scanner/GithubScanService.cs

@@ -2,6 +2,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -54,23 +55,68 @@ namespace FastGithub.Scanner
                 .Build();
         }
 
+        /// <summary>
+        /// 快速扫描所有的ip
+        /// </summary> 
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        public async Task<bool> ScanFastAsync(CancellationToken cancellationToken)
+        {
+            if (RawSocketPing.IsSupported == false)
+            {
+                this.logger.LogWarning($"{Environment.OSVersion.Platform}不支持快速扫描功能");
+                return false;
+            }
+
+            try
+            {
+                this.logger.LogInformation("快速扫描开始..");
+                var domainAddresses = await this.lookupFactory.LookupAsync(cancellationToken);
+
+                // ping快速过滤可用的ip
+                var destAddresses = domainAddresses.Select(item => item.Address);
+                var hashSet = await RawSocketPing.PingAsync(destAddresses, TimeSpan.FromSeconds(3d), cancellationToken);
+                var results = domainAddresses.Where(item => hashSet.Contains(item.Address)).ToArray();
+                this.logger.LogInformation($"快速扫描到{hashSet.Count}条ip，{results.Length}条域名ip记录");
+
+                var successCount = await this.ScanAsync(results, cancellationToken);
+                this.logger.LogInformation($"快速扫描结束，成功{successCount}条共{domainAddresses.Count()}条");
+                return true;
+            }
+            catch (Exception ex)
+            {
+                this.logger.LogWarning($"快速扫描失败：{ex.Message}");
+                return false;
+            }
+        }
+
         /// <summary>
         /// 扫描所有的ip
-        /// </summary>
+        /// </summary> 
+        /// <param name="cancellationToken"></param>
         /// <returns></returns>
         public async Task ScanAllAsync(CancellationToken cancellationToken)
         {
             this.logger.LogInformation("完整扫描开始..");
             var domainAddresses = await this.lookupFactory.LookupAsync(cancellationToken);
+            var successCount = await this.ScanAsync(domainAddresses, cancellationToken);
+            this.logger.LogInformation($"完整扫描结束，成功{successCount}条共{domainAddresses.Count()}条");
+        }
 
+        /// <summary>
+        /// 扫描记录
+        /// </summary>
+        /// <param name="domainAddresses"></param>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        private async Task<int> ScanAsync(IEnumerable<DomainAddress> domainAddresses, CancellationToken cancellationToken)
+        {
             var scanTasks = domainAddresses
                 .Select(item => new GithubContext(item.Domain, item.Address, cancellationToken))
                 .Select(ctx => ScanAsync(ctx));
 
             var results = await Task.WhenAll(scanTasks);
-            var successCount = results.Count(item => item);
-            this.logger.LogInformation($"完整扫描结束，成功{successCount}条共{results.Length}条");
-
+            return results.Count(item => item);
 
             async Task<bool> ScanAsync(GithubContext context)
             {

FastGithub.Scanner/RawSocketPing.cs

@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace FastGithub.Scanner
+{
+    /// <summary>
+    /// RawSocket的ping功能
+    /// </summary>
+    static class RawSocketPing
+    {
+        private static readonly byte[] echoRequestPacket = Convert.FromHexString("0800F6FF0100000000000000");
+        private static readonly byte[] icmpReceiveBuffer = new byte[72];
+
+        /// <summary>
+        /// 获取是否支持
+        /// </summary>
+        public static bool IsSupported { get; private set; }
+
+        /// <summary>
+        /// RawSocket的ping功能
+        /// </summary>
+        static RawSocketPing()
+        {
+            try
+            {
+                new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp).Dispose();
+                IsSupported = true;
+            }
+            catch (Exception)
+            {
+                IsSupported = false;
+            }
+        }
+
+        /// <summary>
+        /// ping目标ip
+        /// </summary>
+        /// <param name="destAddresses"></param>
+        /// <param name="timeWait">等待时间</param>
+        /// <param name="cancellationToken">取消令牌</param>
+        /// <returns>ping通的ip</returns>
+        public static async Task<HashSet<IPAddress>> PingAsync(IEnumerable<IPAddress> destAddresses, TimeSpan timeWait, CancellationToken cancellationToken = default)
+        {
+            using var socket = new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp)
+            {
+                Ttl = 128,
+                DontFragment = false
+            };
+            socket.Bind(new IPEndPoint(IPAddress.Any, 0));
+
+            using var cancellationTokenSource = new CancellationTokenSource();
+            using var linkedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, cancellationTokenSource.Token);
+            var receiveTask = ReceiveAsync(socket, linkedTokenSource.Token);
+
+            var distinctDestAddresses = destAddresses.Distinct();
+            foreach (var address in distinctDestAddresses)
+            {
+                var remoteEndPoint = new IPEndPoint(address, 0);
+                await socket.SendToAsync(echoRequestPacket, SocketFlags.None, remoteEndPoint);
+            }
+
+            await Task.Delay(timeWait, cancellationToken);
+            cancellationTokenSource.Cancel();
+            socket.Close();
+
+            var hashSet = await receiveTask;
+            hashSet.IntersectWith(distinctDestAddresses);
+            return hashSet;
+        }
+
+        /// <summary>
+        /// 循环接收任务
+        /// </summary>
+        /// <param name="socket"></param>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        private static async Task<HashSet<IPAddress>> ReceiveAsync(Socket socket, CancellationToken cancellationToken)
+        {
+            await Task.Yield();
+
+            var hashSet = new HashSet<IPAddress>();
+            var remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
+
+            while (cancellationToken.IsCancellationRequested == false)
+            {
+                try
+                {
+                    var result = await socket.ReceiveFromAsync(icmpReceiveBuffer, SocketFlags.None, remoteEndPoint);
+                    if (result.RemoteEndPoint is IPEndPoint ipEndPoint)
+                    {
+                        hashSet.Add(ipEndPoint.Address);
+                    }
+                }
+                catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
+                {
+                    break;
+                }
+                catch (Exception)
+                {
+                }
+            }
+            return hashSet;
+        }
+    }
+}