add mx record for .loki

include/llarp/dns/message.hpp

@@ -53,6 +53,9 @@ namespace llarp
       void
       AddNXReply();
 
+      void
+      AddMXReply(std::string name, uint16_t priority);
+
       void
       AddINReply(llarp::huint32_t addr);
 

llarp/dns/message.cpp

@@ -189,6 +189,31 @@ namespace llarp
       }
     }
 
+    void
+    Message::AddMXReply(std::string name, uint16_t priority)
+    {
+      if(questions.size())
+      {
+        hdr_fields |= (1 << 15);
+        const auto& question = questions[0];
+        answers.emplace_back();
+        auto& rec       = answers.back();
+        rec.rr_name     = question.qname;
+        rec.rr_type     = question.qtype;
+        rec.rr_class    = 15;
+        rec.ttl         = 1;
+        byte_t tmp[512] = {0};
+        auto buf        = llarp::StackBuffer< decltype(tmp) >(tmp);
+        llarp_buffer_put_uint16(&buf, priority);
+        if(EncodeName(&buf, name))
+        {
+          buf.sz = buf.cur - buf.base;
+          rec.rData.resize(buf.sz);
+          memcpy(rec.rData.data(), buf.base, buf.sz);
+        }
+      }
+    }
+
     void
     Message::AddNXReply()
     {

llarp/handlers/tun.cpp

@@ -184,7 +184,16 @@ namespace llarp
         return false;
       }
       std::string qname = msg.questions[0].qname;
-      if(msg.questions[0].qtype == 1)
+      if(msg.questions[0].qtype == 15)
+      {
+        // mx record
+        llarp::service::Address addr;
+        if(addr.FromString(qname, ".loki"))
+          msg.AddMXReply(qname, 1);
+        else
+          msg.AddNXReply();
+      }
+      else if(msg.questions[0].qtype == 1)
       {
         // forward dns
         llarp::service::Address addr;
@@ -198,10 +207,11 @@ namespace llarp
           }
           else
             return EnsurePathToService(
-              addr,
-              std::bind(&TunEndpoint::SendDNSReply, this, std::placeholders::_1,
-                        std::placeholders::_2, msg, reply),
-              2000);
+                addr,
+                std::bind(&TunEndpoint::SendDNSReply, this,
+                          std::placeholders::_1, std::placeholders::_2, msg,
+                          reply),
+                2000);
         }
         else if(addr.FromString(qname, ".snode"))
         {