分解项目

FastGithub.Core/FastGithub.Core.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<TargetFramework>net5.0</TargetFramework>
+		<Nullable>enable</Nullable>
+	</PropertyGroup>
+
+	<ItemGroup>
+		<PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="5.0.0" />
+	</ItemGroup>
+
+</Project>

FastGithub.Core/OptionsAttribute.cs

@@ -0,0 +1,29 @@
+using System;
+
+namespace FastGithub
+{
+    /// <summary>
+    /// 表示选项特性
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class)]
+    public sealed class OptionsAttribute : Attribute
+    {
+        public string? SessionKey { get; }
+
+        /// <summary>
+        /// 选项特性
+        /// </summary>
+        public OptionsAttribute()
+        {
+        }
+
+        /// <summary>
+        /// 选项特性
+        /// </summary>
+        /// <param name="sessionKey"></param>
+        public OptionsAttribute(string sessionKey)
+        {
+            this.SessionKey = sessionKey;
+        }
+    }
+}

FastGithub.Core/ServiceAttribute.cs

@@ -0,0 +1,32 @@
+using Microsoft.Extensions.DependencyInjection;
+using System;
+
+namespace FastGithub
+{
+    /// <summary>
+    /// 表示服务特性
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
+    public sealed class ServiceAttribute : Attribute
+    {
+        /// <summary>
+        /// 获取服务的生命周期
+        /// </summary>
+        public ServiceLifetime Lifetime { get; }
+
+        /// <summary>
+        /// 获取或设置注册的服务类型
+        /// 为null直接使得当前类型
+        /// </summary>
+        public Type? ServiceType { get; set; }
+
+        /// <summary>
+        /// 将当前实现类型注册为服务的特性
+        /// </summary>
+        /// <param name="lifetime">生命周期</param>
+        public ServiceAttribute(ServiceLifetime lifetime)
+        {
+            Lifetime = lifetime;
+        }
+    }
+}

FastGithub.Core/ServiceCollectionExtensions.cs

@@ -0,0 +1,118 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using System;
+using System.Linq;
+using System.Reflection;
+
+namespace FastGithub
+{
+    /// <summary>
+    /// 服务注册扩展
+    /// </summary>
+    public static class ServiceCollectionExtensions
+    {
+        /// <summary>
+        /// 注册程序集下所有服务下选项
+        /// </summary>
+        /// <param name="services"></param>
+        /// <param name="configuration">配置</param>  
+        /// <returns></returns>
+        public static IServiceCollection AddServiceAndOptions(this IServiceCollection services, Assembly assembly, IConfiguration configuration)
+        { 
+            services.AddAttributeServices(assembly);
+            services.AddAttributeOptions(assembly, configuration); 
+
+            return services;
+        }
+
+        /// <summary>
+        /// 添加程序集下ServiceAttribute标记的服务
+        /// </summary>
+        /// <param name="services"></param>
+        /// <param name="assembly"></param> 
+        /// <returns></returns>
+        private static IServiceCollection AddAttributeServices(this IServiceCollection services, Assembly assembly)
+        {
+            var implTypes = assembly
+                .GetTypes()
+                .Where(item => item.IsClass && item.IsAbstract == false)
+                .ToArray();
+
+            foreach (var implType in implTypes)
+            {
+                var attributes = implType.GetCustomAttributes<ServiceAttribute>(false);
+                foreach (var attr in attributes)
+                {
+                    var serviceType = attr.ServiceType ?? implType;
+                    if (services.Any(item => item.ServiceType == serviceType && item.ImplementationType == implType) == false)
+                    {
+                        var descriptor = ServiceDescriptor.Describe(serviceType, implType, attr.Lifetime);
+                        services.Add(descriptor);
+                    }
+                }
+            }
+            return services;
+        }
+
+
+        /// <summary>
+        /// 添加程序集下OptionsAttribute标记的服务 
+        /// </summary>
+        /// <param name="services"></param>
+        /// <param name="assembly"></param> 
+        /// <param name="configuration"></param>
+        private static IServiceCollection AddAttributeOptions(this IServiceCollection services, Assembly assembly, IConfiguration configuration)
+        {
+            foreach (var optionsType in assembly.GetTypes())
+            {
+                var optionsAttribute = optionsType.GetCustomAttribute<OptionsAttribute>();
+                if (optionsAttribute != null)
+                {
+                    var key = optionsAttribute.SessionKey ?? optionsType.Name;
+                    var section = configuration.GetSection(key);
+                    OptionsBinder.Create(services, optionsType).Bind(section);
+                }
+            }
+            return services;
+        }
+
+        /// <summary>
+        /// options绑定器
+        /// </summary>
+        private abstract class OptionsBinder
+        {
+            public abstract void Bind(IConfiguration configuration);
+
+            /// <summary>
+            /// 创建OptionsBinder实例
+            /// </summary>
+            /// <param name="services"></param>
+            /// <param name="optionsType"></param>
+            /// <returns></returns>
+            public static OptionsBinder Create(IServiceCollection services, Type optionsType)
+            {
+                var binderType = typeof(OptionsBinderImpl<>).MakeGenericType(optionsType);
+                var binder = Activator.CreateInstance(binderType, new object[] { services });
+
+                return binder is OptionsBinder optionsBinder
+                    ? optionsBinder
+                    : throw new TypeInitializationException(binderType.FullName, null);
+            }
+
+            private class OptionsBinderImpl<TOptions> : OptionsBinder where TOptions : class
+            {
+                private readonly IServiceCollection services;
+
+                public OptionsBinderImpl(IServiceCollection services)
+                {
+                    this.services = services;
+                }
+
+                public override void Bind(IConfiguration configuration)
+                {
+                    this.services.AddOptions<TOptions>().Bind(configuration);
+                }
+            }
+        }
+    }
+}

FastGithub.Dns/DnsHostedService.cs

@@ -0,0 +1,38 @@
+using DNS.Server;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace FastGithub.Dns
+{
+    sealed class DnsHostedService : IHostedService
+    {
+        private readonly DnsServer dnsServer; 
+        private readonly ILogger<DnsHostedService> logger;
+
+        public DnsHostedService(
+            GithubRequestResolver githubRequestResolver,
+            IOptions<DnsOptions> options,
+            ILogger<DnsHostedService> logger)
+        {
+            this.dnsServer = new DnsServer(githubRequestResolver, options.Value.UpStream); 
+            this.logger = logger;
+        } 
+
+        public Task StartAsync(CancellationToken cancellationToken)
+        {
+            this.dnsServer.Listen();
+            this.logger.LogInformation("dns服务启用成功");
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            this.dnsServer.Dispose();
+            this.logger.LogInformation("dns服务已终止");
+            return Task.CompletedTask;
+        }
+    }
+}

FastGithub/DnsOptions.cs → FastGithub.Dns/DnsOptions.cs

@@ -1,8 +1,9 @@
 using System.Net;
 
-namespace FastGithub
+namespace FastGithub.Dns
 {
-    class DnsOptions
+    [Options("Dns")]
+    sealed class DnsOptions
     {
         public IPAddress UpStream { get; set; } = IPAddress.Parse("114.114.114.114");
     }

FastGithub.Dns/DnsServiceCollectionExtensions.cs

@@ -0,0 +1,27 @@
+using FastGithub.Dns;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace FastGithub
+{
+    /// <summary>
+    /// 服务注册扩展
+    /// </summary>
+    public static class DnsServiceCollectionExtensions
+    {
+        /// <summary>
+        /// 注册github的dns服务
+        /// </summary>
+        /// <param name="services"></param>
+        /// <param name="configuration">配置</param>  
+        /// <returns></returns>
+        public static IServiceCollection AddGithubDns(this IServiceCollection services, IConfiguration configuration)
+        {
+            var assembly = typeof(DnsServiceCollectionExtensions).Assembly;
+            return services
+                .AddGithubScanner(configuration)
+                .AddServiceAndOptions(assembly, configuration)
+                .AddHostedService<DnsHostedService>();
+        }
+    }
+}

FastGithub.Dns/FastGithub.Dns.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<TargetFramework>net5.0</TargetFramework>
+		<Nullable>enable</Nullable>
+	</PropertyGroup>
+
+	<ItemGroup>
+		<PackageReference Include="DNS" Version="6.1.0" />
+	</ItemGroup>
+
+	<ItemGroup>
+	  <ProjectReference Include="..\FastGithub.Scanner\FastGithub.Scanner.csproj" />
+	</ItemGroup>
+</Project>

FastGithub.Dns/GithubRequestResolver.cs

@@ -0,0 +1,48 @@
+using DNS.Client.RequestResolver;
+using DNS.Protocol;
+using DNS.Protocol.ResourceRecords;
+using FastGithub.Scanner;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace FastGithub.Dns
+{
+    [Service(ServiceLifetime.Singleton)]
+    sealed class GithubRequestResolver : IRequestResolver
+    {
+        private readonly IGithubScanService githubScanService;
+        private readonly ILogger<GithubRequestResolver> logger;
+
+        public GithubRequestResolver(
+            IGithubScanService githubScanService,
+            ILogger<GithubRequestResolver> logger)
+        {
+            this.githubScanService = githubScanService;
+            this.logger = logger;
+        }
+
+        public Task<IResponse> Resolve(IRequest request, CancellationToken cancellationToken = default)
+        {
+            var response = Response.FromRequest(request);
+            var question = request.Questions.FirstOrDefault();
+
+            if (question != null && question.Type == RecordType.A)
+            {
+                var domain = question.Name.ToString();
+                var fastAddress = this.githubScanService.FindFastAddress(domain);
+
+                if (fastAddress != null)
+                {
+                    var record = new IPAddressResourceRecord(question.Name, fastAddress);
+                    response.AnswerRecords.Add(record);
+                    this.logger.LogInformation(record.ToString());
+                }
+            }
+
+            return Task.FromResult<IResponse>(response);
+        }
+    }
+}

FastGithub.Scanner/FastGithub.Scanner.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<TargetFramework>net5.0</TargetFramework>
+		<Nullable>enable</Nullable>
+	</PropertyGroup>
+
+	<ItemGroup>
+		<PackageReference Include="IPNetwork2" Version="2.5.320" />
+		<PackageReference Include="Microsoft.Extensions.Hosting" Version="5.0.0" />
+		<PackageReference Include="Microsoft.Extensions.Http" Version="5.0.0" />
+	</ItemGroup>
+
+	<ItemGroup>
+	  <ProjectReference Include="..\FastGithub.Core\FastGithub.Core.csproj" />
+	</ItemGroup>
+
+</Project>

FastGithub/GithubContext.cs → FastGithub.Scanner/GithubContext.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Net;
 
-namespace FastGithub
+namespace FastGithub.Scanner
 {
-    class GithubContext : IEquatable<GithubContext>
+    sealed class GithubContext : IEquatable<GithubContext>
     {
         public string Domain { get; }
 

FastGithub/GithubContextHashSet.cs → FastGithub.Scanner/GithubContextHashSet.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 
-namespace FastGithub
+namespace FastGithub.Scanner
 {
     class GithubContextHashSet : HashSet<GithubContext>
     {