add AAAA records that return SIIT addresses

llarp/dns/message.cpp

@@ -153,7 +153,7 @@ namespace llarp
     }
 
     void
-    Message::AddINReply(llarp::huint32_t ip, RR_TTL_t ttl)
+    Message::AddINReply(llarp::huint32_t ip, bool isV6, RR_TTL_t ttl)
     {
       if(questions.size())
       {
@@ -161,11 +161,19 @@ namespace llarp
         const auto& question = questions[0];
         ResourceRecord rec;
         rec.rr_name  = question.qname;
-        rec.rr_type  = qTypeA;
         rec.rr_class = qClassIN;
         rec.ttl      = ttl;
-        rec.rData.resize(4);
-        htobe32buf(rec.rData.data(), ip.h);
+        if(isV6)
+        {
+          rec.rr_type = qTypeAAAA;
+          ip.SIIT(rec.rData);
+        }
+        else
+        {
+          rec.rr_type = qTypeA;
+          rec.rData.resize(4);
+          htobe32buf(rec.rData.data(), ip.h);
+        }
         answers.emplace_back(std::move(rec));
       }
     }

llarp/dns/message.hpp

@@ -61,7 +61,7 @@ namespace llarp
       AddCNAMEReply(std::string name, RR_TTL_t ttl = 1);
 
       void
-      AddINReply(llarp::huint32_t addr, RR_TTL_t ttl = 1);
+      AddINReply(llarp::huint32_t addr, bool isV6, RR_TTL_t ttl = 1);
 
       void
       AddAReply(std::string name, RR_TTL_t ttl = 1);

llarp/handlers/exit.cpp

@@ -70,7 +70,8 @@ namespace llarp
         return m_OurRange.Contains(ip);
       }
       else if(msg.questions[0].qtype == dns::qTypeA
-              || msg.questions[0].qtype == dns::qTypeCNAME)
+              || msg.questions[0].qtype == dns::qTypeCNAME
+              || msg.questions[0].qtype == dns::qTypeAAAA)
       {
         // hook for forward dns or cname when using snode tld
         if(msg.questions[0].qname.find(".snode.")
@@ -130,8 +131,10 @@ namespace llarp
         else
           msg.AddNXReply();
       }
-      else if(msg.questions[0].qtype == dns::qTypeA)
+      else if(msg.questions[0].qtype == dns::qTypeA
+              || msg.questions[0].qtype == dns::qTypeAAAA)
       {
+        const bool isV6 = msg.questions[0].qtype == dns::qTypeAAAA;
         if(msg.questions[0].qname == "random.snode"
            || msg.questions[0].qname == "random.snode.")
         {
@@ -146,7 +149,7 @@ namespace llarp
         if(msg.questions[0].qname == "localhost.loki."
            || msg.questions[0].qname == "localhost.loki")
         {
-          msg.AddINReply(GetIfAddr());
+          msg.AddINReply(GetIfAddr(), isV6);
           reply(msg);
           return true;
         }
@@ -161,7 +164,7 @@ namespace llarp
             // we do not have it mapped
             // map it
             ip = ObtainServiceNodeIP(r);
-            msg.AddINReply(ip);
+            msg.AddINReply(ip, isV6);
           }
           else
           {
@@ -170,7 +173,7 @@ namespace llarp
             if(itr != m_KeyToIP.end())
             {
               ip = itr->second;
-              msg.AddINReply(ip);
+              msg.AddINReply(ip, isV6);
             }
             else  // fallback case that should never happen (probably)
               msg.AddNXReply();

llarp/handlers/tun.cpp

@@ -248,7 +248,8 @@ namespace llarp
     TunEndpoint::HandleHookedDNSMessage(
         dns::Message &&msg, std::function< void(dns::Message) > reply)
     {
-      //llarp::LogInfo("Tun.HandleHookedDNSMessage ", msg.questions[0].qname, " of type", msg.questions[0].qtype);
+      // llarp::LogInfo("Tun.HandleHookedDNSMessage ", msg.questions[0].qname, "
+      // of type", msg.questions[0].qtype);
       if(msg.questions.size() != 1)
       {
         llarp::LogWarn("bad number of dns questions: ", msg.questions.size());
@@ -294,8 +295,10 @@ namespace llarp
           msg.AddNXReply();
         reply(msg);
       }
-      else if(msg.questions[0].qtype == dns::qTypeA)
+      else if(msg.questions[0].qtype == dns::qTypeA
+              || msg.questions[0].qtype == dns::qTypeAAAA)
       {
+        const bool isV6 = msg.questions[0].qtype == dns::qTypeAAAA;
         llarp::service::Address addr;
         // on MacOS this is a typeA query
         if(is_random_snode(msg))
@@ -315,7 +318,7 @@ namespace llarp
                 huint32_t ip = service->GetIfAddr();
                 if(ip.h)
                 {
-                  msg.AddINReply(ip);
+                  msg.AddINReply(ip, isV6);
                   ++counter;
                 }
                 return true;
@@ -328,7 +331,7 @@ namespace llarp
           if(HasAddress(addr))
           {
             huint32_t ip = ObtainIPForAddr(addr, false);
-            msg.AddINReply(ip);
+            msg.AddINReply(ip, isV6);
           }
           else
           {
@@ -336,7 +339,7 @@ namespace llarp
             return EnsurePathToService(
                 addr,
                 [=](const service::Address &remote, OutboundContext *ctx) {
-                  SendDNSReply(remote, ctx, replyMsg, reply, false);
+                  SendDNSReply(remote, ctx, replyMsg, reply, false, isV6);
                 },
                 2000);
           }
@@ -346,7 +349,8 @@ namespace llarp
           dns::Message *replyMsg = new dns::Message(std::move(msg));
           EnsurePathToSNode(addr.as_array(),
                             [=](const RouterID &remote, exit::BaseSession *s) {
-                              SendDNSReply(remote, s, replyMsg, reply, true);
+                              SendDNSReply(remote, s, replyMsg, reply, true,
+                                           isV6);
                             });
           return true;
         }

llarp/handlers/tun.hpp

@@ -196,12 +196,13 @@ namespace llarp
       template < typename Addr_t, typename Endpoint_t >
       void
       SendDNSReply(Addr_t addr, Endpoint_t* ctx, dns::Message* query,
-                   std::function< void(dns::Message) > reply, bool snode)
+                   std::function< void(dns::Message) > reply, bool snode,
+                   bool sendIPv6)
       {
         if(ctx)
         {
           huint32_t ip = ObtainIPForAddr(addr, snode);
-          query->AddINReply(ip);
+          query->AddINReply(ip, sendIPv6);
         }
         else
           query->AddNXReply();

llarp/net/net_int.hpp

@@ -53,6 +53,16 @@ namespace llarp
       return out;
     }
 
+    template<typename Container>
+    void SIIT(Container & c)
+    {
+      c.resize(16);
+      std::fill(c.begin(), c.end(), 0);
+      htobe32buf(c.data() + 12, h);
+      c[11] = 0xff;
+      c[10] = 0xff;
+    }
+    
     std::string ToString() const
     {
       uint32_t n = htonl(h);

test/dns/test_llarp_dns_dns.cpp

@@ -115,7 +115,7 @@ TEST_F(DNSLibTest, TestSerializeMessage)
   q.qname      = "whatever.tld";
   q.qclass     = 1;
   q.qtype      = 1;
-  m.AddINReply({1});
+  m.AddINReply({1}, false);
   ASSERT_EQ(m.questions.size(), 1U);
   ASSERT_EQ(m.answers.size(), 1U);
   ASSERT_TRUE(m.Encode(&buf));