From 0925ec9104f9002d17d4fac65d1175f03e407cf5 Mon Sep 17 00:00:00 2001
From: Aigio Liu <lysoft.pw@foxmail.com>
Date: Sat, 16 Sep 2023 18:01:30 +0800
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B=20DoH?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../Net/DnsDohAnalysisService.cs              | 67 ++++++++++---------
 src/BD.WTTS.UnitTest/DnsDohAnalysisTest.cs    | 26 ++++++-
 2 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/src/BD.WTTS.Client.Plugins.Accelerator.ReverseProxy/Services.Implementation/Net/DnsDohAnalysisService.cs b/src/BD.WTTS.Client.Plugins.Accelerator.ReverseProxy/Services.Implementation/Net/DnsDohAnalysisService.cs
index 7eb195786..bdc9de329 100644
--- a/src/BD.WTTS.Client.Plugins.Accelerator.ReverseProxy/Services.Implementation/Net/DnsDohAnalysisService.cs
+++ b/src/BD.WTTS.Client.Plugins.Accelerator.ReverseProxy/Services.Implementation/Net/DnsDohAnalysisService.cs
@@ -83,10 +83,10 @@ sealed class DnsDohAnalysisService : GeneralHttpClientFactory
         return 0;
     }
 
-    /// <summary>
-    /// DNS 解析查询最大递归查询次数
-    /// </summary>
-    const byte max_recursion_dns_query = 20;
+    ///// <summary>
+    ///// DNS 解析查询最大递归查询次数
+    ///// </summary>
+    //const byte max_recursion_dns_query = 20;
 
     static readonly TimeSpan TTL = TimeSpan.FromMinutes(9.9D);
 
@@ -104,37 +104,37 @@ sealed class DnsDohAnalysisService : GeneralHttpClientFactory
         Uri dohAddresUri,
         string hostNameOrAddress,
         DnsQueryType queryType = DnsQueryType.A,
-        byte count = 1,
-        HashSet<string>? domainHistory = null,
+        //byte count = 1,
+        //HashSet<string>? domainHistory = null,
         CancellationToken cancellationToken = default)
     {
-        if (count <= max_recursion_dns_query)
-        {
-            domainHistory ??= new();
-            var query = DnsQueryFactory.CreateQuery(hostNameOrAddress, queryType);
-            var dnsClient = GetDnsHttpClient(dohAddresUri);
-            var answer = await dnsClient.Query(query, cancellationToken);
+        //if (count <= max_recursion_dns_query)
+        //{
+        //    domainHistory ??= new();
+        var query = DnsQueryFactory.CreateQuery(hostNameOrAddress, queryType);
+        var dnsClient = GetDnsHttpClient(dohAddresUri);
+        var answer = await dnsClient.Query(query, cancellationToken);
 
-            var dnsResources = answer.Answers.Select(x => x.Resource);
+        var dnsResources = answer.Answers.Select(x => x.Resource);
 
-            var iPAddresses = dnsResources.OfType<DnsIpAddressResource>().Select(x => x.IPAddress).ToArray();
-            if (iPAddresses.Any())
-                return iPAddresses;
+        var iPAddresses = dnsResources.OfType<DnsIpAddressResource>().Select(x => x.IPAddress).ToArray();
+        if (iPAddresses.Any())
+            return iPAddresses;
 
-            var domainRes = dnsResources.OfType<DnsDomainResource>().FirstOrDefault();
-            if (domainRes != null)
-            {
-                var domain = domainRes.Domain;
-                if (!string.IsNullOrWhiteSpace(domain))
-                {
-                    if (domainHistory.Add(domain))
-                    {
-                        // CNAME 递归解析
-                        iPAddresses = await Query(dohAddresUri, domain, queryType, ++count, domainHistory, cancellationToken);
-                    }
-                }
-            }
-        }
+        //var domainRes = dnsResources.OfType<DnsDomainResource>().FirstOrDefault();
+        //if (domainRes != null)
+        //{
+        //    var domain = domainRes.Domain;
+        //    if (!string.IsNullOrWhiteSpace(domain))
+        //    {
+        //        //if (domainHistory.Add(domain))
+        //        //{
+        //        // CNAME 递归解析
+        //        iPAddresses = await Query(dohAddresUri, domain, queryType,/* ++count, domainHistory,*/ cancellationToken);
+        //        //}
+        //    }
+        //}
+        ////}
 
         return Array.Empty<IPAddress>();
     }
@@ -181,6 +181,13 @@ sealed class DnsDohAnalysisService : GeneralHttpClientFactory
         }
 
         var result = await Query(dohAddresUri, hostNameOrAddress, queryType, cancellationToken: cancellationToken);
+
+        if (isIPv6 && !result.Any())
+        {
+            // IPv6 返回空时使用 IPv4 解析
+            result = await Query(dohAddresUri, hostNameOrAddress, DnsQueryType.A, cancellationToken: cancellationToken);
+        }
+
         if (useCache)
         {
             Cache[cacheKey] = new()
diff --git a/src/BD.WTTS.UnitTest/DnsDohAnalysisTest.cs b/src/BD.WTTS.UnitTest/DnsDohAnalysisTest.cs
index 681c7c52f..6f34e3bcb 100644
--- a/src/BD.WTTS.UnitTest/DnsDohAnalysisTest.cs
+++ b/src/BD.WTTS.UnitTest/DnsDohAnalysisTest.cs
@@ -11,7 +11,8 @@ public sealed class DnsDohAnalysisTest
         {
             s.AddLogging(s => s.AddConsole());
             s.TryAddClientHttpPlatformHelperService();
-            s.AddFusilladeHttpClient();
+            FusilladeHttpClientFactory2 factory = new();
+            s.AddSingleton<IHttpClientFactory>(factory);
             s.AddSingleton<DnsDohAnalysisService>();
         });
 
@@ -23,8 +24,8 @@ public sealed class DnsDohAnalysisTest
             DNS_Ali_DohAddres,
             DNS_Ali_DohAddres2,
             DNS_Ali_DohAddres3,
-            Google_DohAddres,
-            Cloudflare_DohAddres,
+            //Google_DohAddres,
+            //Cloudflare_DohAddres,
             DohAddres_360,
             TUNA_DohAddres,
         };
@@ -62,4 +63,23 @@ public sealed class DnsDohAnalysisTest
             Console.WriteLine("--------------------");
         }
     }
+}
+
+sealed class FusilladeHttpClientFactory2 : FusilladeHttpClientFactory
+{
+    protected override HttpClient CreateClient(HttpMessageHandler handler)
+    {
+        var client = new HttpClient(handler);
+
+        try
+        {
+            client.Timeout = TimeSpan.FromSeconds(14.5D);
+        }
+        catch
+        {
+
+        }
+
+        return client;
+    }
 }
\ No newline at end of file