Merge branch 'experiments/resolver'

Conflicts:
	src/bin/resolver/resolver.cc

src/bin/auth/auth_srv.cc

@@ -159,9 +159,13 @@ AuthSrvImpl::~AuthSrvImpl() {
 class MessageLookup : public DNSLookup {
 public:
     MessageLookup(AuthSrv* srv) : server_(srv) {}
-    virtual void operator()(const IOMessage& io_message, MessagePtr message,
-                            OutputBufferPtr buffer, DNSServer* server) const
+    virtual void operator()(const IOMessage& io_message,
+                            MessagePtr message,
+                            MessagePtr answer_message,
+                            OutputBufferPtr buffer,
+                            DNSServer* server) const
     {
+        (void) answer_message;
         server_->processMessage(io_message, message, buffer, server);
     }
 private:
@@ -180,7 +184,7 @@ class MessageAnswer : public DNSAnswer {
 public:
     MessageAnswer(AuthSrv*) {}
     virtual void operator()(const IOMessage&, MessagePtr,
-                            OutputBufferPtr) const
+                            MessagePtr, OutputBufferPtr) const
     {}
 };
 

src/bin/auth/tests/auth_srv_unittest.cc

@@ -138,9 +138,10 @@ TEST_F(AuthSrvTest, builtInQueryViaDNSServer) {
     createRequestPacket(request_message, IPPROTO_UDP);
 
     (*server.getDNSLookupProvider())(*io_message, parse_message,
+                                     response_message,
                                      response_obuffer, &dnsserv);
     (*server.getDNSAnswerProvider())(*io_message, parse_message,
-                                     response_obuffer);
+                                     response_message, response_obuffer);
 
     createBuiltinVersionResponse(default_qid, response_data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
@@ -153,9 +154,10 @@ TEST_F(AuthSrvTest, builtInQueryViaDNSServer) {
 TEST_F(AuthSrvTest, iqueryViaDNSServer) {
     createDataFromFile("iquery_fromWire.wire");
     (*server.getDNSLookupProvider())(*io_message, parse_message,
+                                     response_message,
                                      response_obuffer, &dnsserv);
     (*server.getDNSAnswerProvider())(*io_message, parse_message,
-                                     response_obuffer);
+                                     response_message, response_obuffer);
 
     UnitTestUtil::readWireData("iquery_response_fromWire.wire",
                                response_data);

src/bin/resolver/resolver.cc

@@ -95,20 +95,20 @@ public:
     {
         upstream_ = upstream;
         if (dnss) {
-            if (upstream_.empty()) {
-                dlog("Asked to do full recursive, but not implemented yet. "
-                    "I'll do nothing.",true);
-            } else {
+            if (!upstream_.empty()) {
                 dlog("Setting forward addresses:");
                 BOOST_FOREACH(const addr_t& address, upstream) {
                     dlog(" " + address.first + ":" +
                         boost::lexical_cast<string>(address.second));
                 }
+            } else {
+                dlog("No forward addresses, running in recursive mode");
             }
         }
     }
 
-    void processNormalQuery(const Question& question, MessagePtr message,
+    void processNormalQuery(const Question& question,
+                            MessagePtr answer_message,
                             OutputBufferPtr buffer,
                             DNSServer* server);
 
@@ -149,20 +149,6 @@ public:
     MessagePtr message_;
 };
 
-class SectionInserter {
-public:
-    SectionInserter(MessagePtr message, const Message::Section sect) :
-        message_(message), section_(sect)
-    {}
-    void operator()(const RRsetPtr rrset) {
-        //dlog("Adding RRSet to message section " +
-        //    boost::lexical_cast<string>(section_));
-        message_->addRRset(section_, rrset, true);
-    }
-    MessagePtr message_;
-    const Message::Section section_;
-};
-
 void
 makeErrorMessage(MessagePtr message, OutputBufferPtr buffer,
                  const Rcode& rcode)
@@ -210,10 +196,14 @@ public:
     MessageLookup(Resolver* srv) : server_(srv) {}
 
     // \brief Handle the DNS Lookup
-    virtual void operator()(const IOMessage& io_message, MessagePtr message,
-                            OutputBufferPtr buffer, DNSServer* server) const
+    virtual void operator()(const IOMessage& io_message,
+                            MessagePtr query_message,
+                            MessagePtr answer_message,
+                            OutputBufferPtr buffer,
+                            DNSServer* server) const
     {
-        server_->processMessage(io_message, message, buffer, server);
+        server_->processMessage(io_message, query_message,
+                                answer_message, buffer, server);
     }
 private:
     Resolver* server_;
@@ -226,76 +216,62 @@ private:
 class MessageAnswer : public DNSAnswer {
 public:
     virtual void operator()(const IOMessage& io_message,
-                            MessagePtr message,
+                            MessagePtr query_message,
+                            MessagePtr answer_message,
                             OutputBufferPtr buffer) const
     {
-        const qid_t qid = message->getQid();
-        const bool rd = message->getHeaderFlag(Message::HEADERFLAG_RD);
-        const bool cd = message->getHeaderFlag(Message::HEADERFLAG_CD);
-        const Opcode& opcode = message->getOpcode();
-        const Rcode& rcode = message->getRcode();
-        vector<QuestionPtr> questions;
-        questions.assign(message->beginQuestion(), message->endQuestion());
+        const qid_t qid = query_message->getQid();
+        const bool rd = query_message->getHeaderFlag(Message::HEADERFLAG_RD);
+        const bool cd = query_message->getHeaderFlag(Message::HEADERFLAG_CD);
+        const Opcode& opcode = query_message->getOpcode();
 
-        message->clear(Message::RENDER);
-        message->setQid(qid);
-        message->setOpcode(opcode);
-        message->setRcode(rcode);
+        // Fill in the final details of the answer message
+        answer_message->setQid(qid);
+        answer_message->setOpcode(opcode);
 
-        message->setHeaderFlag(Message::HEADERFLAG_QR);
-        message->setHeaderFlag(Message::HEADERFLAG_RA);
+        answer_message->setHeaderFlag(Message::HEADERFLAG_QR);
+        answer_message->setHeaderFlag(Message::HEADERFLAG_RA);
         if (rd) {
-            message->setHeaderFlag(Message::HEADERFLAG_RD);
+            answer_message->setHeaderFlag(Message::HEADERFLAG_RD);
         }
         if (cd) {
-            message->setHeaderFlag(Message::HEADERFLAG_CD);
-        }
-
-
-        // Copy the question section.
-        for_each(questions.begin(), questions.end(), QuestionInserter(message));
-
-        // If the buffer already has an answer in it, copy RRsets from
-        // that into the new message, then clear the buffer and render
-        // the new message into it.
-        if (buffer->getLength() != 0) {
-            try {
-                Message incoming(Message::PARSE);
-                InputBuffer ibuf(buffer->getData(), buffer->getLength());
-                incoming.fromWire(ibuf);
-                message->setRcode(incoming.getRcode());
-                for_each(incoming.beginSection(Message::SECTION_ANSWER),
-                         incoming.endSection(Message::SECTION_ANSWER),
-                         SectionInserter(message, Message::SECTION_ANSWER));
-                for_each(incoming.beginSection(Message::SECTION_AUTHORITY),
-                         incoming.endSection(Message::SECTION_AUTHORITY),
-                         SectionInserter(message, Message::SECTION_AUTHORITY));
-                for_each(incoming.beginSection(Message::SECTION_ADDITIONAL),
-                         incoming.endSection(Message::SECTION_ADDITIONAL),
-                         SectionInserter(message, Message::SECTION_ADDITIONAL));
-            } catch (const Exception& ex) {
-                // Incoming message couldn't be read, we just SERVFAIL
-                message->setRcode(Rcode::SERVFAIL());
-            }
+            answer_message->setHeaderFlag(Message::HEADERFLAG_CD);
         }
 
+        vector<QuestionPtr> questions;
+        questions.assign(query_message->beginQuestion(), query_message->endQuestion());
+        for_each(questions.begin(), questions.end(), QuestionInserter(answer_message));
+        
         // Now we can clear the buffer and render the new message into it
         buffer->clear();
         MessageRenderer renderer(*buffer);
 
+        ConstEDNSPtr edns(query_message->getEDNS());
+        const bool dnssec_ok = edns && edns->getDNSSECAwareness();
+        if (edns) {
+            EDNSPtr edns_response(new EDNS());
+            edns_response->setDNSSECAwareness(dnssec_ok);
+
+            // TODO: We should make our own edns bufsize length configurable
+            edns_response->setUDPSize(Message::DEFAULT_MAX_EDNS0_UDPSIZE);
+            answer_message->setEDNS(edns_response);
+        }
+        
         if (io_message.getSocket().getProtocol() == IPPROTO_UDP) {
-            ConstEDNSPtr edns(message->getEDNS());
-            renderer.setLengthLimit(edns ? edns->getUDPSize() :
-                Message::DEFAULT_MAX_UDPSIZE);
+            if (edns) {
+                renderer.setLengthLimit(edns->getUDPSize());
+            } else {
+                renderer.setLengthLimit(Message::DEFAULT_MAX_UDPSIZE);
+            }
         } else {
             renderer.setLengthLimit(65535);
         }
 
-        message->toWire(renderer);
+        answer_message->toWire(renderer);
 
         dlog(string("sending a response (") +
             boost::lexical_cast<string>(renderer.getLength()) + "bytes): \n" +
-            message->toText());
+            answer_message->toText());
     }
 };
 
@@ -345,18 +321,21 @@ Resolver::getConfigSession() const {
 }
 
 void
-Resolver::processMessage(const IOMessage& io_message, MessagePtr message,
-                        OutputBufferPtr buffer, DNSServer* server)
+Resolver::processMessage(const IOMessage& io_message,
+                         MessagePtr query_message,
+                         MessagePtr answer_message,
+                         OutputBufferPtr buffer,
+                         DNSServer* server)
 {
     dlog("Got a DNS message");
     InputBuffer request_buffer(io_message.getData(), io_message.getDataSize());
     // First, check the header part.  If we fail even for the base header,
     // just drop the message.
     try {
-        message->parseHeader(request_buffer);
+        query_message->parseHeader(request_buffer);
 
         // Ignore all responses.
-        if (message->getHeaderFlag(Message::HEADERFLAG_QR)) {
+        if (query_message->getHeaderFlag(Message::HEADERFLAG_QR)) {
             dlog("Received unexpected response, ignoring");
             server->resume(false);
             return;
@@ -369,52 +348,53 @@ Resolver::processMessage(const IOMessage& io_message, MessagePtr message,
 
     // Parse the message.  On failure, return an appropriate error.
     try {
-        message->fromWire(request_buffer);
+        query_message->fromWire(request_buffer);
     } catch (const DNSProtocolError& error) {
         dlog(string("returning ") + error.getRcode().toText() + ": " + 
             error.what());
-        makeErrorMessage(message, buffer, error.getRcode());
+        makeErrorMessage(query_message, buffer, error.getRcode());
         server->resume(true);
         return;
     } catch (const Exception& ex) {
         dlog(string("returning SERVFAIL: ") + ex.what());
-        makeErrorMessage(message, buffer, Rcode::SERVFAIL());
+        makeErrorMessage(query_message, buffer, Rcode::SERVFAIL());
         server->resume(true);
         return;
     } // other exceptions will be handled at a higher layer.
 
-    dlog("received a message:\n" + message->toText());
+    dlog("received a message:\n" + query_message->toText());
 
     // Perform further protocol-level validation.
     bool sendAnswer = true;
-    if (message->getOpcode() == Opcode::NOTIFY()) {
-        makeErrorMessage(message, buffer, Rcode::NOTAUTH());
+    if (query_message->getOpcode() == Opcode::NOTIFY()) {
+        makeErrorMessage(query_message, buffer, Rcode::NOTAUTH());
         dlog("Notify arrived, but we are not authoritative");
-    } else if (message->getOpcode() != Opcode::QUERY()) {
-        dlog("Unsupported opcode (got: " + message->getOpcode().toText() +
+    } else if (query_message->getOpcode() != Opcode::QUERY()) {
+        dlog("Unsupported opcode (got: " + query_message->getOpcode().toText() +
             ", expected: " + Opcode::QUERY().toText());
-        makeErrorMessage(message, buffer, Rcode::NOTIMP());
-    } else if (message->getRRCount(Message::SECTION_QUESTION) != 1) {
+        makeErrorMessage(query_message, buffer, Rcode::NOTIMP());
+    } else if (query_message->getRRCount(Message::SECTION_QUESTION) != 1) {
         dlog("The query contained " +
-            boost::lexical_cast<string>(message->getRRCount(
+            boost::lexical_cast<string>(query_message->getRRCount(
             Message::SECTION_QUESTION) + " questions, exactly one expected"));
-        makeErrorMessage(message, buffer, Rcode::FORMERR());
+        makeErrorMessage(query_message, buffer, Rcode::FORMERR());
     } else {
-        ConstQuestionPtr question = *message->beginQuestion();
+        ConstQuestionPtr question = *query_message->beginQuestion();
         const RRType &qtype = question->getType();
         if (qtype == RRType::AXFR()) {
             if (io_message.getSocket().getProtocol() == IPPROTO_UDP) {
-                makeErrorMessage(message, buffer, Rcode::FORMERR());
+                makeErrorMessage(query_message, buffer, Rcode::FORMERR());
             } else {
-                makeErrorMessage(message, buffer, Rcode::NOTIMP());
+                makeErrorMessage(query_message, buffer, Rcode::NOTIMP());
             }
         } else if (qtype == RRType::IXFR()) {
-            makeErrorMessage(message, buffer, Rcode::NOTIMP());
+            makeErrorMessage(query_message, buffer, Rcode::NOTIMP());
         } else {
             // The RecursiveQuery object will post the "resume" event to the
             // DNSServer when an answer arrives, so we don't have to do it now.
             sendAnswer = false;
-            impl_->processNormalQuery(*question, message, buffer, server);
+            impl_->processNormalQuery(*question, answer_message,
+                                      buffer, server);
         }
     }
 
@@ -424,23 +404,13 @@ Resolver::processMessage(const IOMessage& io_message, MessagePtr message,
 }
 
 void
-ResolverImpl::processNormalQuery(const Question& question, MessagePtr message,
-                                 OutputBufferPtr buffer, DNSServer* server)
+ResolverImpl::processNormalQuery(const Question& question,
+                                 MessagePtr answer_message,
+                                 OutputBufferPtr buffer,
+                                 DNSServer* server)
 {
     dlog("Processing normal query");
-    ConstEDNSPtr edns(message->getEDNS());
-    const bool dnssec_ok = edns && edns->getDNSSECAwareness();
-
-    message->makeResponse();
-    message->setHeaderFlag(Message::HEADERFLAG_RA);
-    message->setRcode(Rcode::NOERROR());
-    if (edns) {
-        EDNSPtr edns_response(new EDNS());
-        edns_response->setDNSSECAwareness(dnssec_ok);
-        edns_response->setUDPSize(ResolverImpl::DEFAULT_LOCAL_UDPSIZE);
-        message->setEDNS(edns_response);
-    }
-    rec_query_->sendQuery(question, buffer, server);
+    rec_query_->sendQuery(question, answer_message, buffer, server);
 }
 
 namespace {

src/bin/resolver/resolver.h

@@ -63,7 +63,8 @@ public:
     /// \param buffer Pointer to an \c OutputBuffer for the resposne
     /// \param server Pointer to the \c DNSServer
     void processMessage(const asiolink::IOMessage& io_message,
-                        isc::dns::MessagePtr message,
+                        isc::dns::MessagePtr query_message,
+                        isc::dns::MessagePtr answer_message,
                         isc::dns::OutputBufferPtr buffer,
                         asiolink::DNSServer* server);
 

src/bin/resolver/tests/resolver_config_unittest.cc

@@ -134,8 +134,8 @@ TEST_F(ResolverConfig, listenAddresses) {
 
     // Try putting there some addresses
     vector<pair<string, uint16_t> > addresses;
-    addresses.push_back(pair<string, uint16_t>("127.0.0.1", 5300));
-    addresses.push_back(pair<string, uint16_t>("::1", 5300));
+    addresses.push_back(pair<string, uint16_t>("127.0.0.1", 5321));
+    addresses.push_back(pair<string, uint16_t>("::1", 5321));
     server.setListenAddresses(addresses);
     EXPECT_EQ(2, server.getListenAddresses().size());
     EXPECT_EQ("::1", server.getListenAddresses()[1].first);
@@ -155,7 +155,7 @@ TEST_F(ResolverConfig, DISABLED_listenAddressConfig) {
         "\"listen_on\": ["
         "   {"
         "       \"address\": \"127.0.0.1\","
-        "       \"port\": 5300"
+        "       \"port\": 5321"
         "   }"
         "]"
         "}"));
@@ -163,7 +163,7 @@ TEST_F(ResolverConfig, DISABLED_listenAddressConfig) {
     EXPECT_EQ(result->toWire(), isc::config::createAnswer()->toWire());
     ASSERT_EQ(1, server.getListenAddresses().size());
     EXPECT_EQ("127.0.0.1", server.getListenAddresses()[0].first);
-    EXPECT_EQ(5300, server.getListenAddresses()[0].second);
+    EXPECT_EQ(5321, server.getListenAddresses()[0].second);
 
     // As this is example address, the machine should not have it on
     // any interface
@@ -174,7 +174,7 @@ TEST_F(ResolverConfig, DISABLED_listenAddressConfig) {
         "\"listen_on\": ["
         "   {"
         "       \"address\": \"192.0.2.0\","
-        "       \"port\": 5300"
+        "       \"port\": 5321"
         "   }"
         "]"
         "}");
@@ -182,7 +182,7 @@ TEST_F(ResolverConfig, DISABLED_listenAddressConfig) {
     EXPECT_FALSE(result->equals(*isc::config::createAnswer()));
     ASSERT_EQ(1, server.getListenAddresses().size());
     EXPECT_EQ("127.0.0.1", server.getListenAddresses()[0].first);
-    EXPECT_EQ(5300, server.getListenAddresses()[0].second);
+    EXPECT_EQ(5321, server.getListenAddresses()[0].second);
 }
 
 TEST_F(ResolverConfig, invalidListenAddresses) {

src/bin/resolver/tests/resolver_unittest.cc

@@ -30,7 +30,10 @@ class ResolverTest : public SrvTestBase{
 protected:
     ResolverTest() : server(){}
     virtual void processMessage() {
-        server.processMessage(*io_message, parse_message, response_obuffer,
+        server.processMessage(*io_message,
+                              parse_message,
+                              response_message,
+                              response_obuffer,
                               &dnsserv);
     }
     Resolver server;
@@ -83,7 +86,11 @@ TEST_F(ResolverTest, AXFRFail) {
                                        RRType::AXFR());
     createRequestPacket(request_message, IPPROTO_TCP);
     // AXFR is not implemented and should always send NOTIMP.
-    server.processMessage(*io_message, parse_message, response_obuffer, &dnsserv);
+    server.processMessage(*io_message,
+                          parse_message,
+                          response_message,
+                          response_obuffer,
+                          &dnsserv);
     EXPECT_TRUE(dnsserv.hasAnswer());
     headerCheck(*parse_message, default_qid, Rcode::NOTIMP(), opcode.getCode(),
                 QR_FLAG, 1, 0, 0, 0);
@@ -98,7 +105,11 @@ TEST_F(ResolverTest, notifyFail) {
     request_message.setQid(default_qid);
     request_message.setHeaderFlag(Message::HEADERFLAG_AA);
     createRequestPacket(request_message, IPPROTO_UDP);
-    server.processMessage(*io_message, parse_message, response_obuffer, &dnsserv);
+    server.processMessage(*io_message,
+                          parse_message,
+                          response_message,
+                          response_obuffer,
+                          &dnsserv);
     EXPECT_TRUE(dnsserv.hasAnswer());
     headerCheck(*parse_message, default_qid, Rcode::NOTAUTH(),
                 Opcode::NOTIFY().getCode(), QR_FLAG, 0, 0, 0, 0);

src/lib/asiolink/asiolink.cc

@@ -30,6 +30,7 @@
 
 #include <dns/buffer.h>
 #include <dns/message.h>
+#include <dns/rcode.h>
 
 #include <asiolink/asiolink.h>
 #include <asiolink/internal/tcpdns.h>
@@ -37,6 +38,7 @@
 
 #include <log/dummylog.h>
 
+
 using namespace asio;
 using asio::ip::udp;
 using asio::ip::tcp;
@@ -46,8 +48,46 @@ using namespace isc::dns;
 using isc::log::dlog;
 using namespace boost;
 
+// Is this something we can use in libdns++?
+namespace {
+    class SectionInserter {
+    public:
+        SectionInserter(MessagePtr message, const Message::Section sect) :
+            message_(message), section_(sect)
+        {}
+        void operator()(const RRsetPtr rrset) {
+            message_->addRRset(section_, rrset, true);
+        }
+        MessagePtr message_;
+        const Message::Section section_;
+    };
+
+
+    /// \brief Copies the parts relevant for a DNS answer to the
+    /// target message
+    ///
+    /// This adds all the RRsets in the answer, authority and
+    /// additional sections to the target, as well as the response
+    /// code
+    void copyAnswerMessage(const Message& source, MessagePtr target) {
+        target->setRcode(source.getRcode());
+
+        for_each(source.beginSection(Message::SECTION_ANSWER),
+                 source.endSection(Message::SECTION_ANSWER),
+                 SectionInserter(target, Message::SECTION_ANSWER));
+        for_each(source.beginSection(Message::SECTION_AUTHORITY),
+                 source.endSection(Message::SECTION_AUTHORITY),
+                 SectionInserter(target, Message::SECTION_AUTHORITY));
+        for_each(source.beginSection(Message::SECTION_ADDITIONAL),
+                 source.endSection(Message::SECTION_ADDITIONAL),
+                 SectionInserter(target, Message::SECTION_ADDITIONAL));
+    }
+}
+
 namespace asiolink {
 
+typedef pair<string, uint16_t> addr_t;
+
 class IOServiceImpl {
 private:
     IOServiceImpl(const IOService& source);
@@ -296,6 +336,12 @@ private:
 
     // Info for (re)sending the query (the question and destination)
     Question question_;
+
+    // This is where we build and store our final answer
+    MessagePtr answer_message_;
+
+    // currently we use upstream as the current list of NS records
+    // we should differentiate between forwarding and resolving
     shared_ptr<AddressVector> upstream_;
 
     // Buffer to store the result.
@@ -312,9 +358,26 @@ private:
     int timeout_;
     unsigned retries_;
 
+    // normal query state
+
+    // if we change this to running and add a sent, we can do
+    // decoupled timeouts i think
+    bool done;
+
+    // Not using NSAS at this moment, so we keep a list
+    // of 'current' zone servers
+    vector<addr_t> zone_servers_;
+
+    // Update the question that will be sent to the server
+    void setQuestion(const Question& new_question) {
+        question_ = new_question;
+    }
+
     // (re)send the query to the server.
     void send() {
         const int uc = upstream_->size();
+        const int zs = zone_servers_.size();
+        buffer_->clear();
         if (uc > 0) {
             int serverIndex = rand() % uc;
             dlog("Sending upstream query (" + question_.toText() +
@@ -324,34 +387,138 @@ private:
                 upstream_->at(serverIndex).second, buffer_, this,
                 timeout_);
             io_.post(query);
+        } else if (zs > 0) {
+            int serverIndex = rand() % zs;
+            dlog("Sending query to zone server (" + question_.toText() +
+                ") to " + zone_servers_.at(serverIndex).first);
+            UDPQuery query(io_, question_,
+                zone_servers_.at(serverIndex).first,
+                zone_servers_.at(serverIndex).second, buffer_, this,
+                timeout_);
+            io_.post(query);
         } else {
             dlog("Error, no upstream servers to send to.");
         }
     }
+    
+    // This function is called by operator() if there is an actual
+    // answer from a server and we are in recursive mode
+    // depending on the contents, we go on recursing or return
+    //
+    // Note that the footprint may change as this function may
+    // need to append data to the answer we are building later.
+    //
+    // returns true if we are done
+    // returns false if we are not done
+    bool handleRecursiveAnswer(const Message& incoming) {
+        if (incoming.getRRCount(Message::SECTION_ANSWER) > 0) {
+            dlog("Got final result, copying answer.");
+            copyAnswerMessage(incoming, answer_message_);
+            return true;
+        } else {
+            dlog("Got delegation, continuing");
+            // ok we need to do some more processing.
+            // the ns list should contain all nameservers
+            // while the additional may contain addresses for
+            // them.
+            // this needs to tie into NSAS of course
+            // for this very first mockup, hope there is an
+            // address in additional and just use that
+
+            // send query to the addresses in the delegation
+            bool found_ns_address = false;
+            zone_servers_.clear();
+
+            for (RRsetIterator rrsi = incoming.beginSection(Message::SECTION_ADDITIONAL);
+                 rrsi != incoming.endSection(Message::SECTION_ADDITIONAL) && !found_ns_address;
+                 rrsi++) {
+                ConstRRsetPtr rrs = *rrsi;
+                if (rrs->getType() == RRType::A()) {
+                    // found address
+                    RdataIteratorPtr rdi = rrs->getRdataIterator();
+                    // just use the first for now
+                    if (!rdi->isLast()) {
+                        std::string addr_str = rdi->getCurrent().toText();
+                        dlog("[XX] first address found: " + addr_str);
+                        // now we have one address, simply
+                        // resend that exact same query