Registry: Allow the DNS server to send multiple messages

This is required for zone transfer.
bosagora · Sep 9, 2021 · 19f26be · 19f26be
1 parent 80cebb4
commit 19f26be
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Showing 2 changed files with 17 additions and 10 deletions.
diff --git a/source/agora/node/Registry.d b/source/agora/node/Registry.d
@@ -208,13 +208,15 @@ public class NameRegistry: NameRegistryAPI
 
         Params:
           query = The query received by the server
-
-        Returns:
-          An answer that matches the query
+          sender = A delegate that allows to send a `Message` to the client.
+                   A server may send multiple `Message`s as a response to a
+                   single query, e.g. when doing zone transfer.
 
     ***************************************************************************/
 
-    public Message answerQuestions (in Message query) @safe
+    public void answerQuestions (
+        in Message query, scope void delegate (in Message) @safe sender)
+        @safe
     {
         Message reply;
         reply.header.RA = false; // TODO: Implement
@@ -253,7 +255,7 @@ public class NameRegistry: NameRegistryAPI
         log.trace("{} DNS query: {} => {}",
                   (reply.header.RCODE == Header.RCode.NoError) ? "Fullfilled" : "Unsuccessfull",
                   query, reply);
-        return reply.fill(query.header);
+        sender(reply.fill(query.header));
     }
 
     /***************************************************************************

diff --git a/source/agora/node/Runner.d b/source/agora/node/Runner.d
@@ -294,14 +294,17 @@ private void runDNSServer_canThrow (in RegistryConfig config, NameRegistry regis
     ubyte[2048] buffer;
     // `recv` will store the peer address here so we can respond
     NetworkAddress peer;
+    scope ppeer = &peer;
     while (true)
     {
         try
         {
-            auto pack = udp.recv(buffer, &peer);
+            auto pack = udp.recv(buffer, ppeer);
             auto query = deserializeFull!Message(pack);
-            auto resp = registry.answerQuestions(query);
-            udp.send(serializeFull(resp), &peer);
+            registry.answerQuestions(
+                query,
+                (in Message msg) @safe => udp.send(msg.serializeFull(), ppeer));
+
         }
         catch (Exception exc)
         {
@@ -369,8 +372,10 @@ private void runTCPDNSServer_canThrow (TCPConnection conn, NameRegistry registry
     try
     {
         auto query = deserializeFull!Message(reader);
-        auto resp = registry.answerQuestions(query);
-        resp.serializePart(&conn.write);
+        registry.answerQuestions(
+            query,
+            (in Message msg) @safe => msg.serializePart(&conn.write));
+
     }
     catch (Exception exc)
     {