src/iterative-query.cpp

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2014, Regents of the University of California.
 *
 * This file is part of NDNS (Named Data Networking Domain Name Service).
 * See AUTHORS.md for complete list of NDNS authors and contributors.
 *
 * NDNS is free software: you can redistribute it and/or modify it under the terms
 * of the GNU General Public License as published by the Free Software Foundation,
 * either version 3 of the License, or (at your option) any later version.
 *
 * NDNS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * NDNS, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "iterative-query.hpp"

namespace ndn {
namespace ndns {

IterativeQuery::IterativeQuery(const Query& query)
: m_step(IterativeQuery::NSQuery)
, m_tryNum(0)
, m_tryMax(2)
, m_query(query)
, m_finishedLabelNum(0)
, m_rrLabelLen(1)
, m_authZoneIndex(0)
{
}


bool
IterativeQuery::doTimeout()
{
  abort();
  return false;
}

void
IterativeQuery::abort(){
  std::cout<<(*this);
  std::cout<<std::endl;
}

void
IterativeQuery::doData(Data& data)
{
  std::cout<<"[* -> *] resolve Data: "<<data.getName().toUri()<<std::endl;
  Response re;
  re.fromData(data);
  std::cout<<re<<std::endl;

  if (re.getResponseType() == Response::UNKNOWN)
  {
    std::cout<<"[* !! *] unknown content type and exit";
    m_step = Abort;
    abort();
    return;
  }
  else if (re.getResponseType() == Response::NDNS_Nack)
  {
      if (m_step == NSQuery) {
        //In fact, there are two different situations
        //1st: /net/ndnsim/DNS/www/NS is nacked
        //2st: /net/DNS/ndnsim/www/NS is nacked
        m_step = RRQuery;

      } else if (m_step == RRQuery)
      {
        m_step = AnswerStub;
      }
      m_lastResponse = re;
  }
  else if (re.getResponseType() == Response::NDNS_Auth)
  { // need more specific info
    m_rrLabelLen += 1;

  }
  else if (re.getResponseType() == Response::NDNS_Resp)
  {// get the intermediate answer
    if (m_step == NSQuery) {
      //do nothing, step NSQuery
      m_finishedLabelNum += m_rrLabelLen;
      m_rrLabelLen = 1;
      m_authZoneIndex = 0;
      m_lastResponse = re;

    } else if (m_step == RRQuery)
    { // final resolver gets result back
      m_step = AnswerStub;
      m_lastResponse = re;
    }

    std::cout<<"get RRs: "<<m_lastResponse.getStringRRs()<<std::endl;
  }

}

const Interest
IterativeQuery::toLatestInterest()
{
  Query query = Query();
  Name dstLabel = m_query.getRrLabel();

  Name authZone = dstLabel.getPrefix(m_finishedLabelNum);

  Name label;
  if (m_step == RRQuery) {
    label = dstLabel.getSubName(m_finishedLabelNum);
  }
  else {
    label = dstLabel.getSubName(m_finishedLabelNum, m_rrLabelLen);
  }
  query.setAuthorityZone(authZone);
  query.setRrLabel(label);

  if (m_step == NSQuery)
  {
    query.setRrType(RR::NS);
    query.setQueryType(Query::QUERY_DNS);
  } else if (m_step == RRQuery)
  {
    query.setRrType(m_query.getRrType());
    query.setQueryType(Query::QUERY_DNS);
  } else if (m_step == AnswerStub)
  {
    query.setRrType(m_query.getRrType());
    query.setQueryType(Query::QUERY_DNS);
  }
  Interest interest = query.toInterest();
  //m_lastInterest = interest;

  return interest;
}

} /* namespace ndns */
} /* namespace ndn */