(#71) Get rid of custom resolver and use DnsClient in a mobile-friend…

…ly way
vitalyster · Oct 3, 2021 · 0f117f3 · 0f117f3
1 parent 3d7203a
commit 0f117f3
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Showing 5 changed files with 21 additions and 135 deletions.
diff --git a/SharpXMPP.NUnit/Compat/TcpClientExTests.cs b/SharpXMPP.NUnit/Compat/TcpClientExTests.cs
@@ -37,7 +37,7 @@ public void TestCancellation()
                         var token = cts.Token;
 
                         using var client = new TcpClient();
-                        var task = client.ConnectWithCancellationAsync(IPAddress.Loopback, port, token);
+                        var task = client.ConnectWithCancellationAsync(new[] { IPAddress.Loopback }, port, token);
                         cts.Cancel();
 
                         try

diff --git a/SharpXMPP.Shared/Compat/TcpClientEx.cs b/SharpXMPP.Shared/Compat/TcpClientEx.cs
@@ -33,19 +33,6 @@ private static async Task AbandonOnCancel(this Task task, CancellationToken canc
         // the resources will be freed upon its destruction. Which means we are free to just abandon the task in
         // question.
 
-        public static Task ConnectWithCancellationAsync(
-            this TcpClient tcpClient,
-            IPAddress address,
-            int port,
-            CancellationToken cancellationToken)
-        {
-#if NET5_0_OR_GREATER
-            return tcpClient.ConnectAsync(address, port, cancellationToken).AsTask();
-#else
-            return tcpClient.ConnectAsync(address, port).AbandonOnCancel(cancellationToken);
-#endif
-        }
-
         public static Task ConnectWithCancellationAsync(
             this TcpClient tcpClient,
             IPAddress[] addresses,

diff --git a/SharpXMPP.Shared/Resolver.cs b/SharpXMPP.Shared/Resolver.cs
diff --git a/SharpXMPP.Shared/SharpXMPP.Shared.csproj b/SharpXMPP.Shared/SharpXMPP.Shared.csproj
@@ -31,4 +31,8 @@
     <PackageReference Include="System.Net.NameResolution" Version="4.3.0" />
     <PackageReference Include="System.Net.Security" Version="4.3.2" />
   </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="DnsClient" Version="1.5.0" />
+  </ItemGroup>
 </Project>
diff --git a/SharpXMPP.Shared/XmppTcpConnection.cs b/SharpXMPP.Shared/XmppTcpConnection.cs
@@ -8,6 +8,7 @@
 using System.Threading.Tasks;
 using System.Xml;
 using System.Xml.Linq;
+using DnsClient;
 using SharpXMPP.Compat;
 using SharpXMPP.Errors;
 using SharpXMPP.XMPP;
@@ -24,6 +25,12 @@ public class XmppTcpConnection : XmppConnection
         private object _terminationLock = new object();
         private TcpClient _client;
 
+        /// <summary>
+        /// A list of name servers to use for the DNS lookup. Uses 1.1.1.1 by default. If empty, then will use the name
+        /// servers configured by the local network adapter(s).
+        /// </summary>
+        public IPAddress[] NameServers { get; set; } = { IPAddress.Parse("1.1.1.1") };
+
         protected virtual int TcpPort
         {
             get { return 5222; }
@@ -294,13 +301,18 @@ private async Task<List<IPAddress>> ResolveHostAddresses(CancellationToken cance
         {
             List<IPAddress> HostAddresses = new List<IPAddress>();
 
-            var srvs = await Resolver.ResolveXMPPClient(Jid.Domain, cancellationToken);
-            if (srvs.Any())
+            var lookup = NameServers.Length > 0 ? new LookupClient(NameServers) : new LookupClient();
+
+            var response = await lookup.QueryAsync(
+                "_xmpp-client._tcp." + Jid.Domain,
+                QueryType.SRV,
+                cancellationToken: cancellationToken);
+            if (response.Answers.SrvRecords().Any())
             {
-                foreach (var srv in srvs)
+                foreach (var srv in response.Answers.SrvRecords())
                 {
                     cancellationToken.ThrowIfCancellationRequested();
-                    var addresses = await Dns.GetHostAddressesAsync(srv.Host);
+                    var addresses = await Dns.GetHostAddressesAsync(srv.Target.Value);
                     HostAddresses.AddRange(addresses);
                 }
             }