[thirdparty/pdns.git] / pdns / recursordist / rpzloader.cc

/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include <condition_variable>
#include "arguments.hh"
#include "dnsparser.hh"
#include "dnsrecords.hh"
#include "ixfr.hh"
#include "syncres.hh"
#include "axfr-retriever.hh"
#include "lock.hh"
#include "logger.hh"
#include "logging.hh"
#include "rec-lua-conf.hh"
#include "rpzloader.hh"
#include "zoneparser-tng.hh"
#include "threadname.hh"
#include "query-local-address.hh"

Netmask makeNetmaskFromRPZ(const DNSName& name)
{
  auto parts = name.getRawLabels();
  /*
   * why 2?, the minimally valid IPv6 address that can be encoded in an RPZ is
   * $NETMASK.zz (::/$NETMASK)
   * Terrible right?
   */
  if (parts.size() < 2 || parts.size() > 9)
    throw PDNSException("Invalid IP address in RPZ: " + name.toLogString());

  bool isV6 = (stoi(parts[0]) > 32);
  bool hadZZ = false;

  for (auto& part : parts) {
    // Check if we have an IPv4 octet
    for (auto c : part)
      if (!isdigit(c))
        isV6 = true;

    if (pdns_iequals(part, "zz")) {
      if (hadZZ)
        throw PDNSException("more than one 'zz' label found in RPZ name" + name.toLogString());
      part = "";
      isV6 = true;
      hadZZ = true;
    }
  }

  if (isV6 && parts.size() < 9 && !hadZZ)
    throw PDNSException("No 'zz' label found in an IPv6 RPZ name shorter than 9 elements: " + name.toLogString());

  if (parts.size() == 5 && !isV6)
    return Netmask(parts[4] + "." + parts[3] + "." + parts[2] + "." + parts[1] + "/" + parts[0]);

  string v6;

  if (parts[parts.size() - 1] == "") {
    v6 += ":";
  }
  for (uint8_t i = parts.size() - 1; i > 0; i--) {
    v6 += parts[i];
    if (i > 1 || (i == 1 && parts[i] == "")) {
      v6 += ":";
    }
  }
  v6 += "/" + parts[0];

  return Netmask(v6);
}

static void RPZRecordToPolicy(const DNSRecord& dr, std::shared_ptr<DNSFilterEngine::Zone> zone, bool addOrRemove, const boost::optional<DNSFilterEngine::Policy>& defpol, bool defpolOverrideLocal, uint32_t maxTTL, Logr::log_t log)
{
  static const DNSName drop("rpz-drop."), truncate("rpz-tcp-only."), noaction("rpz-passthru.");
  static const DNSName rpzClientIP("rpz-client-ip"), rpzIP("rpz-ip"),
    rpzNSDname("rpz-nsdname"), rpzNSIP("rpz-nsip.");
  static const std::string rpzPrefix("rpz-");

  DNSFilterEngine::Policy pol;
  bool defpolApplied = false;

  if (dr.d_class != QClass::IN) {
    return;
  }

  if (dr.d_type == QType::CNAME) {
    auto crc = getRR<CNAMERecordContent>(dr);
    if (!crc) {
      return;
    }
    auto crcTarget = crc->getTarget();
    if (defpol) {
      pol = *defpol;
      defpolApplied = true;
    }
    else if (crcTarget.isRoot()) {
      // cerr<<"Wants NXDOMAIN for "<<dr.d_name<<": ";
      pol.d_kind = DNSFilterEngine::PolicyKind::NXDOMAIN;
    }
    else if (crcTarget == g_wildcarddnsname) {
      // cerr<<"Wants NODATA for "<<dr.d_name<<": ";
      pol.d_kind = DNSFilterEngine::PolicyKind::NODATA;
    }
    else if (crcTarget == drop) {
      // cerr<<"Wants DROP for "<<dr.d_name<<": ";
      pol.d_kind = DNSFilterEngine::PolicyKind::Drop;
    }
    else if (crcTarget == truncate) {
      // cerr<<"Wants TRUNCATE for "<<dr.d_name<<": ";
      pol.d_kind = DNSFilterEngine::PolicyKind::Truncate;
    }
    else if (crcTarget == noaction) {
      // cerr<<"Wants NOACTION for "<<dr.d_name<<": ";
      pol.d_kind = DNSFilterEngine::PolicyKind::NoAction;
    }
    /* "The special RPZ encodings which are not to be taken as Local Data are
       CNAMEs with targets that are:
       +  "."  (NXDOMAIN action),
       +  "*." (NODATA action),
       +  a top level domain starting with "rpz-",
       +  a child of a top level domain starting with "rpz-".
    */
    else if (!crcTarget.empty() && !crcTarget.isRoot() && crcTarget.getRawLabel(crcTarget.countLabels() - 1).compare(0, rpzPrefix.length(), rpzPrefix) == 0) {
      /* this is very likely an higher format number or a configuration error,
         let's just ignore it. */
      SLOG(g_log << Logger::Info << "Discarding unsupported RPZ entry " << crcTarget << " for " << dr.d_name << endl,
           log->info(Logr::Info, "Discarding unsupported RPZ entry", "target", Logging::Loggable(crcTarget), "name", Logging::Loggable(dr.d_name)));
      return;
    }
    else {
      pol.d_kind = DNSFilterEngine::PolicyKind::Custom;
      pol.d_custom.emplace_back(dr.getContent());
      // cerr<<"Wants custom "<<crcTarget<<" for "<<dr.d_name<<": ";
    }
  }
  else {
    if (defpol && defpolOverrideLocal) {
      pol = *defpol;
      defpolApplied = true;
    }
    else {
      pol.d_kind = DNSFilterEngine::PolicyKind::Custom;
      pol.d_custom.emplace_back(dr.getContent());
      // cerr<<"Wants custom "<<dr.d_content->getZoneRepresentation()<<" for "<<dr.d_name<<": ";
    }
  }

  if (!defpolApplied || defpol->d_ttl < 0) {
    pol.d_ttl = static_cast<int32_t>(std::min(maxTTL, dr.d_ttl));
  }
  else {
    pol.d_ttl = static_cast<int32_t>(std::min(maxTTL, static_cast<uint32_t>(pol.d_ttl)));
  }

  // now to DO something with that

  if (dr.d_name.isPartOf(rpzNSDname)) {
    DNSName filt = dr.d_name.makeRelative(rpzNSDname);
    if (addOrRemove)
      zone->addNSTrigger(filt, std::move(pol), defpolApplied);
    else
      zone->rmNSTrigger(filt, std::move(pol));
  }
  else if (dr.d_name.isPartOf(rpzClientIP)) {
    DNSName filt = dr.d_name.makeRelative(rpzClientIP);
    auto nm = makeNetmaskFromRPZ(filt);
    if (addOrRemove)
      zone->addClientTrigger(nm, std::move(pol), defpolApplied);
    else
      zone->rmClientTrigger(nm, std::move(pol));
  }
  else if (dr.d_name.isPartOf(rpzIP)) {
    // cerr<<"Should apply answer content IP policy: "<<dr.d_name<<endl;
    DNSName filt = dr.d_name.makeRelative(rpzIP);
    auto nm = makeNetmaskFromRPZ(filt);
    if (addOrRemove)
      zone->addResponseTrigger(nm, std::move(pol), defpolApplied);
    else
      zone->rmResponseTrigger(nm, std::move(pol));
  }
  else if (dr.d_name.isPartOf(rpzNSIP)) {
    DNSName filt = dr.d_name.makeRelative(rpzNSIP);
    auto nm = makeNetmaskFromRPZ(filt);
    if (addOrRemove)
      zone->addNSIPTrigger(nm, std::move(pol), defpolApplied);
    else
      zone->rmNSIPTrigger(nm, std::move(pol));
  }
  else {
    if (addOrRemove) {
      /* if we did override the existing policy with the default policy,
         we might turn two A or AAAA into a CNAME, which would trigger
         an exception. Let's just ignore it. */
      zone->addQNameTrigger(dr.d_name, std::move(pol), defpolApplied);
    }
    else {
      zone->rmQNameTrigger(dr.d_name, std::move(pol));
    }
  }
}

static shared_ptr<const SOARecordContent> loadRPZFromServer(Logr::log_t plogger, const ComboAddress& primary, const DNSName& zoneName, std::shared_ptr<DNSFilterEngine::Zone> zone, const boost::optional<DNSFilterEngine::Policy>& defpol, bool defpolOverrideLocal, uint32_t maxTTL, const TSIGTriplet& tt, size_t maxReceivedBytes, const ComboAddress& localAddress, uint16_t axfrTimeout)
{

  auto logger = plogger->withValues("primary", Logging::Loggable(primary));
  SLOG(g_log << Logger::Warning << "Loading RPZ zone '" << zoneName << "' from " << primary.toStringWithPort() << endl,
       logger->info(Logr::Info, "Loading RPZ from nameserver"));
  if (!tt.name.empty()) {
    SLOG(g_log << Logger::Warning << "With TSIG key '" << tt.name << "' of algorithm '" << tt.algo << "'" << endl,
         logger->info(Logr::Info, "Using TSIG key for authentication", "tsig_key_name", Logging::Loggable(tt.name), "tsig_key_algorithm", Logging::Loggable(tt.algo)));
  }

  ComboAddress local(localAddress);
  if (local == ComboAddress())
    local = pdns::getQueryLocalAddress(primary.sin4.sin_family, 0);

  AXFRRetriever axfr(primary, zoneName, tt, &local, maxReceivedBytes, axfrTimeout);
  unsigned int nrecords = 0;
  Resolver::res_t nop;
  vector<DNSRecord> chunk;
  time_t last = 0;
  time_t axfrStart = time(nullptr);
  time_t axfrNow = time(nullptr);
  shared_ptr<const SOARecordContent> sr;
  // coverity[store_truncates_time_t]
  while (axfr.getChunk(nop, &chunk, (axfrStart + axfrTimeout - axfrNow))) {
    for (auto& dr : chunk) {
      if (dr.d_type == QType::NS || dr.d_type == QType::TSIG) {
        continue;
      }

      dr.d_name.makeUsRelative(zoneName);
      if (dr.d_type == QType::SOA) {
        sr = getRR<SOARecordContent>(dr);
        zone->setSOA(dr);
        continue;
      }

      RPZRecordToPolicy(dr, zone, true, defpol, defpolOverrideLocal, maxTTL, logger);
      nrecords++;
    }
    axfrNow = time(nullptr);
    if (axfrNow < axfrStart || axfrNow - axfrStart > axfrTimeout) {
      throw PDNSException("Total AXFR time exceeded!");
    }
    if (last != time(0)) {
      SLOG(g_log << Logger::Info << "Loaded & indexed " << nrecords << " policy records so far for RPZ zone '" << zoneName << "'" << endl,
           logger->info(Logr::Info, "RPZ load in progress", "nrecords", Logging::Loggable(nrecords)));
      last = time(0);
    }
  }
  SLOG(g_log << Logger::Info << "Done: " << nrecords << " policy records active, SOA: " << sr->getZoneRepresentation() << endl,
       logger->info(Logr::Info, "RPZ load completed", "nrecords", Logging::Loggable(nrecords), "soa", Logging::Loggable(sr->getZoneRepresentation())));
  return sr;
}

static LockGuarded<std::unordered_map<std::string, shared_ptr<rpzStats>>> s_rpzStats;

shared_ptr<rpzStats> getRPZZoneStats(const std::string& zone)
{
  auto stats = s_rpzStats.lock();
  auto it = stats->find(zone);
  if (it == stats->end()) {
    auto stat = std::make_shared<rpzStats>();
    (*stats)[zone] = stat;
    return stat;
  }
  return it->second;
}

static void incRPZFailedTransfers(const std::string& zone)
{
  auto stats = getRPZZoneStats(zone);
  if (stats != nullptr)
    stats->d_failedTransfers++;
}

static void setRPZZoneNewState(const std::string& zone, uint32_t serial, uint64_t numberOfRecords, bool fromFile, bool wasAXFR)
{
  auto stats = getRPZZoneStats(zone);
  if (stats == nullptr) {
    return;
  }
  if (!fromFile) {
    stats->d_successfulTransfers++;
    if (wasAXFR) {
      stats->d_fullTransfers++;
    }
  }
  stats->d_lastUpdate = time(nullptr);
  stats->d_serial = serial;
  stats->d_numberOfRecords = numberOfRecords;
}

// this function is silent - you do the logging
std::shared_ptr<const SOARecordContent> loadRPZFromFile(const std::string& fname, std::shared_ptr<DNSFilterEngine::Zone> zone, const boost::optional<DNSFilterEngine::Policy>& defpol, bool defpolOverrideLocal, uint32_t maxTTL)
{
  shared_ptr<const SOARecordContent> sr = nullptr;
  ZoneParserTNG zpt(fname);
  zpt.setMaxGenerateSteps(::arg().asNum("max-generate-steps"));
  zpt.setMaxIncludes(::arg().asNum("max-include-depth"));
  DNSResourceRecord drr;
  DNSRecord soaRecord;
  DNSName domain;
  auto log = g_slog->withName("rpz")->withValues("file", Logging::Loggable(fname), "zone", Logging::Loggable(zone->getName()));
  while (zpt.get(drr)) {
    try {
      if (drr.qtype.getCode() == QType::CNAME && drr.content.empty())
        drr.content = ".";
      DNSRecord dr(drr);
      if (dr.d_type == QType::SOA) {
        sr = getRR<SOARecordContent>(dr);
        domain = dr.d_name;
        zone->setDomain(domain);
        soaRecord = std::move(dr);
      }
      else if (dr.d_type == QType::NS) {
        continue;
      }
      else {
        dr.d_name = dr.d_name.makeRelative(domain);
        RPZRecordToPolicy(dr, zone, true, defpol, defpolOverrideLocal, maxTTL, log);
      }
    }
    catch (const PDNSException& pe) {
      throw PDNSException("Issue parsing '" + drr.qname.toLogString() + "' '" + drr.content + "' at " + zpt.getLineOfFile() + ": " + pe.reason);
    }
  }

  if (sr != nullptr) {
    zone->setRefresh(sr->d_st.refresh);
    zone->setSOA(std::move(soaRecord));
    setRPZZoneNewState(zone->getName(), sr->d_st.serial, zone->size(), true, false);
  }
  return sr;
}

static bool dumpZoneToDisk(Logr::log_t logger, const DNSName& zoneName, const std::shared_ptr<DNSFilterEngine::Zone>& newZone, const std::string& dumpZoneFileName)
{
  logger->info(Logr::Debug, "Dumping zone to disk", "destination_file", Logging::Loggable(dumpZoneFileName));
  std::string temp = dumpZoneFileName + "XXXXXX";
  int fd = mkstemp(&temp.at(0));
  if (fd < 0) {
    SLOG(g_log << Logger::Warning << "Unable to open a file to dump the content of the RPZ zone " << zoneName << endl,
         logger->error(Logr::Error, errno, "Unable to create temporary file"));
    return false;
  }

  auto fp = std::unique_ptr<FILE, int (*)(FILE*)>(fdopen(fd, "w+"), fclose);
  if (!fp) {
    int err = errno;
    close(fd);
    SLOG(g_log << Logger::Warning << "Unable to open a file pointer to dump the content of the RPZ zone " << zoneName << endl,
         logger->error(Logr::Error, err, "Unable to open file pointer"));
    return false;
  }

  try {
    newZone->dump(fp.get());
  }
  catch (const std::exception& e) {
    SLOG(g_log << Logger::Warning << "Error while dumping the content of the RPZ zone " << zoneName << ": " << e.what() << endl,
         logger->error(Logr::Error, e.what(), "Error while dumping the content of the RPZ"));
    return false;
  }

  if (fflush(fp.get()) != 0) {
    SLOG(g_log << Logger::Warning << "Error while flushing the content of the RPZ zone " << zoneName << " to the dump file: " << stringerror() << endl,
         logger->error(Logr::Warning, errno, "Error while flushing the content of the RPZ"));
    return false;
  }

  if (fsync(fileno(fp.get())) != 0) {
    SLOG(g_log << Logger::Warning << "Error while syncing the content of the RPZ zone " << zoneName << " to the dump file: " << stringerror() << endl,
         logger->error(Logr::Error, errno, "Error while syncing the content of the RPZ"));
    return false;
  }

  if (fclose(fp.release()) != 0) {
    SLOG(g_log << Logger::Warning << "Error while writing the content of the RPZ zone " << zoneName << " to the dump file: " << stringerror() << endl,
         logger->error(Logr::Error, errno, "Error while writing the content of the RPZ"));
    return false;
  }

  if (rename(temp.c_str(), dumpZoneFileName.c_str()) != 0) {
    SLOG(g_log << Logger::Warning << "Error while moving the content of the RPZ zone " << zoneName << " to the dump file: " << stringerror() << endl,
         logger->error(Logr::Error, errno, "Error while moving the content of the RPZ", "destination_file", Logging::Loggable(dumpZoneFileName)));
    return false;
  }

  return true;
}

// A struct that holds the condition var and related stuff to allow notifies to be sent to the tread owning
// the struct.
struct RPZWaiter
{
  RPZWaiter(std::thread::id arg) :
    id(arg) {}
  std::thread::id id;
  std::mutex mutex;
  std::condition_variable condVar;
  std::atomic<bool> stop{false};
};

static void preloadRPZFIle(RPZTrackerParams& params, const DNSName& zoneName, std::shared_ptr<DNSFilterEngine::Zone>& oldZone, uint32_t& refresh, const string& polName, RPZWaiter& rpzwaiter, Logr::log_t logger)
{
  while (!params.soaRecordContent) {
    /* if we received an empty sr, the zone was not really preloaded */

    /* full copy, as promised */
    std::shared_ptr<DNSFilterEngine::Zone> newZone = std::make_shared<DNSFilterEngine::Zone>(*oldZone);
    for (const auto& primary : params.primaries) {
      try {
        params.soaRecordContent = loadRPZFromServer(logger, primary, zoneName, newZone, params.defpol, params.defpolOverrideLocal, params.maxTTL, params.tsigtriplet, params.maxReceivedBytes, params.localAddress, params.xfrTimeout);
        newZone->setSerial(params.soaRecordContent->d_st.serial);
        newZone->setRefresh(params.soaRecordContent->d_st.refresh);
        refresh = std::max(params.refreshFromConf != 0 ? params.refreshFromConf : newZone->getRefresh(), 1U);
        setRPZZoneNewState(polName, params.soaRecordContent->d_st.serial, newZone->size(), false, true);

        g_luaconfs.modify([zoneIdx = params.zoneIdx, &newZone](LuaConfigItems& lci) {
          lci.dfe.setZone(zoneIdx, newZone);
        });

        if (!params.dumpZoneFileName.empty()) {
          dumpZoneToDisk(logger, zoneName, newZone, params.dumpZoneFileName);
        }

        /* no need to try another primary */
        break;
      }
      catch (const std::exception& e) {
        SLOG(g_log << Logger::Warning << "Unable to load RPZ zone '" << zoneName << "' from '" << primary << "': '" << e.what() << "'. (Will try again in " << refresh << " seconds...)" << endl,
             logger->error(Logr::Warning, e.what(), "Unable to load RPZ zone, will retry", "from", Logging::Loggable(primary), "exception", Logging::Loggable("std::exception"), "refresh", Logging::Loggable(refresh)));
        incRPZFailedTransfers(polName);
      }
      catch (const PDNSException& e) {
        SLOG(g_log << Logger::Warning << "Unable to load RPZ zone '" << zoneName << "' from '" << primary << "': '" << e.reason << "'. (Will try again in " << refresh << " seconds...)" << endl,
             logger->error(Logr::Warning, e.reason, "Unable to load RPZ zone, will retry", "from", Logging::Loggable(primary), "exception", Logging::Loggable("PDNSException"), "refresh", Logging::Loggable(refresh)));
        incRPZFailedTransfers(polName);
      }
    }
    // Release newZone before (long) sleep to reduce memory usage
    newZone = nullptr;
    if (!params.soaRecordContent) {
      std::unique_lock lock(rpzwaiter.mutex);
      rpzwaiter.condVar.wait_for(lock, std::chrono::seconds(refresh),
                                 [&stop = rpzwaiter.stop] { return stop.load(); });
    }
    rpzwaiter.stop = false;
  }
}

static bool RPZTrackerIteration(RPZTrackerParams& params, const DNSName& zoneName, std::shared_ptr<DNSFilterEngine::Zone>& oldZone, uint32_t& refresh, const string& polName, bool& skipRefreshDelay, uint64_t configGeneration, RPZWaiter& rpzwaiter, Logr::log_t logger)
{
  // Don't hold on to oldZone, it well be re-assigned after sleep in the try block
  oldZone = nullptr;
  DNSRecord dnsRecord;
  dnsRecord.setContent(params.soaRecordContent);

  if (skipRefreshDelay) {
    skipRefreshDelay = false;
  }
  else {
    std::unique_lock lock(rpzwaiter.mutex);
    rpzwaiter.condVar.wait_for(lock, std::chrono::seconds(refresh),
                               [&stop = rpzwaiter.stop] { return stop.load(); });
    rpzwaiter.stop = false;
  }
  auto luaconfsLocal = g_luaconfs.getLocal();

  if (luaconfsLocal->generation != configGeneration) {
    /* the configuration has been reloaded, meaning that a new thread
       has been started to handle that zone and we are now obsolete.
    */
    SLOG(g_log << Logger::Info << "A more recent configuration has been found, stopping the existing RPZ update thread for " << zoneName << endl,
         logger->info(Logr::Info, "A more recent configuration has been found, stopping the existing RPZ update thread"));
    return false;
  }

  vector<pair<vector<DNSRecord>, vector<DNSRecord>>> deltas;
  for (const auto& primary : params.primaries) {
    auto soa = getRR<SOARecordContent>(dnsRecord);
    auto serial = soa ? soa->d_st.serial : 0;
    SLOG(g_log << Logger::Info << "Getting IXFR deltas for " << zoneName << " from " << primary.toStringWithPort() << ", our serial: " << serial << endl,
         logger->info(Logr::Info, "Getting IXFR deltas", "address", Logging::Loggable(primary), "ourserial", Logging::Loggable(serial)));

    ComboAddress local(params.localAddress);
    if (local == ComboAddress()) {
      local = pdns::getQueryLocalAddress(primary.sin4.sin_family, 0);
    }

    try {
      deltas = getIXFRDeltas(primary, zoneName, dnsRecord, params.xfrTimeout, true, params.tsigtriplet, &local, params.maxReceivedBytes);

      /* no need to try another primary */
      break;
    }
    catch (const std::runtime_error& e) {
      SLOG(g_log << Logger::Warning << e.what() << endl,
           logger->error(Logr::Warning, e.what(), "Exception during retrieval of delta", "exception", Logging::Loggable("std::runtime_error")));
      incRPZFailedTransfers(polName);
      continue;
    }
  }

  if (deltas.empty()) {
    return true;
  }

  try {
    SLOG(g_log << Logger::Info << "Processing " << deltas.size() << " delta" << addS(deltas) << " for RPZ " << zoneName << endl,
         logger->info(Logr::Info, "Processing deltas", "size", Logging::Loggable(deltas.size())));

    if (luaconfsLocal->generation != configGeneration) {
      SLOG(g_log << Logger::Info << "A more recent configuration has been found, stopping the existing RPZ update thread for " << zoneName << endl,
           logger->info(Logr::Info, "A more recent configuration has been found, stopping the existing RPZ update thread"));
      return false;
    }
    oldZone = luaconfsLocal->dfe.getZone(params.zoneIdx);
    if (!oldZone || oldZone->getDomain() != zoneName) {
      SLOG(g_log << Logger::Info << "This policy is no more, stopping the existing RPZ update thread for " << zoneName << endl,
           logger->info(Logr::Info, "This policy is no more, stopping the existing RPZ update thread"));
      return false;
    }
    /* we need to make a _full copy_ of the zone we are going to work on */
    std::shared_ptr<DNSFilterEngine::Zone> newZone = std::make_shared<DNSFilterEngine::Zone>(*oldZone);
    /* initialize the current serial to the last one */
    std::shared_ptr<const SOARecordContent> currentSR = params.soaRecordContent;

    int totremove = 0;
    int totadd = 0;
    bool fullUpdate = false;
    for (const auto& delta : deltas) {
      const auto& remove = delta.first;
      const auto& add = delta.second;
      if (remove.empty()) {
        SLOG(g_log << Logger::Warning << "IXFR update is a whole new zone" << endl,
             logger->info(Logr::Warning, "IXFR update is a whole new zone"));
        newZone->clear();
        fullUpdate = true;
      }
      for (const auto& resourceRecord : remove) { // should always contain the SOA
        if (resourceRecord.d_type == QType::NS) {
          continue;
        }
        if (resourceRecord.d_type == QType::SOA) {
          auto oldsr = getRR<SOARecordContent>(resourceRecord);
          if (oldsr && oldsr->d_st.serial == currentSR->d_st.serial) {
            //	Got good removal of SOA serial, no work to be done
          }
          else {
            if (!oldsr) {
              throw std::runtime_error("Unable to extract serial from SOA record while processing the removal part of an update");
            }
            throw std::runtime_error("Received an unexpected serial (" + std::to_string(oldsr->d_st.serial) + ", expecting " + std::to_string(currentSR->d_st.serial) + ") from SOA record while processing the removal part of an update");
          }
        }
        else {
          totremove++;
          SLOG(g_log << (g_logRPZChanges ? Logger::Info : Logger::Debug) << "Had removal of " << resourceRecord.d_name << " from RPZ zone " << zoneName << endl,
               logger->info(g_logRPZChanges ? Logr::Info : Logr::Debug, "Remove from RPZ zone", "name", Logging::Loggable(resourceRecord.d_name)));
          RPZRecordToPolicy(resourceRecord, newZone, false, params.defpol, params.defpolOverrideLocal, params.maxTTL, logger);
        }
      }

      for (const auto& resourceRecord : add) { // should always contain the new SOA
        if (resourceRecord.d_type == QType::NS) {
          continue;
        }
        if (resourceRecord.d_type == QType::SOA) {
          auto tempSR = getRR<SOARecordContent>(resourceRecord);
          if (tempSR) {
            currentSR = std::move(tempSR);
          }
        }
        else {
          totadd++;
          SLOG(g_log << (g_logRPZChanges ? Logger::Info : Logger::Debug) << "Had addition of " << resourceRecord.d_name << " to RPZ zone " << zoneName << endl,
               logger->info(g_logRPZChanges ? Logr::Info : Logr::Debug, "Addition to RPZ zone", "name", Logging::Loggable(resourceRecord.d_name)));
          RPZRecordToPolicy(resourceRecord, newZone, true, params.defpol, params.defpolOverrideLocal, params.maxTTL, logger);
        }
      }
    }

    /* only update sr now that all changes have been converted */
    if (currentSR) {
      params.soaRecordContent = std::move(currentSR);
    }
    SLOG(g_log << Logger::Info << "Had " << totremove << " RPZ removal" << addS(totremove) << ", " << totadd << " addition" << addS(totadd) << " for " << zoneName << " New serial: " << params.soaRecordContent->d_st.serial << endl,
         logger->info(Logr::Info, "RPZ mutations", "removals", Logging::Loggable(totremove), "additions", Logging::Loggable(totadd), "newserial", Logging::Loggable(params.soaRecordContent->d_st.serial)));
    newZone->setSerial(params.soaRecordContent->d_st.serial);
    newZone->setRefresh(params.soaRecordContent->d_st.refresh);
    setRPZZoneNewState(polName, params.soaRecordContent->d_st.serial, newZone->size(), false, fullUpdate);

    /* we need to replace the existing zone with the new one,
       but we don't want to touch anything else, especially other zones,
       since they might have been updated by another RPZ IXFR tracker thread.
    */
    if (luaconfsLocal->generation != configGeneration) {
      SLOG(g_log << Logger::Info << "A more recent configuration has been found, stopping the existing RPZ update thread for " << zoneName << endl,
           logger->info(Logr::Info, "A more recent configuration has been found, stopping the existing RPZ update thread"));
      return false;
    }
    g_luaconfs.modify([zoneIdx = params.zoneIdx, &newZone](LuaConfigItems& lci) {
      lci.dfe.setZone(zoneIdx, newZone);
    });

    if (!params.dumpZoneFileName.empty()) {
      dumpZoneToDisk(logger, zoneName, newZone, params.dumpZoneFileName);
    }
    refresh = std::max(params.refreshFromConf != 0 ? params.refreshFromConf : newZone->getRefresh(), 1U);
  }
  catch (const std::exception& e) {
    SLOG(g_log << Logger::Error << "Error while applying the update received over XFR for " << zoneName << ", skipping the update: " << e.what() << endl,
         logger->error(Logr::Error, e.what(), "Exception while applying the update received over XFR, skipping", "exception", Logging::Loggable("std::exception")));
  }
  catch (const PDNSException& e) {
    SLOG(g_log << Logger::Error << "Error while applying the update received over XFR for " << zoneName << ", skipping the update: " << e.reason << endl,
         logger->error(Logr::Error, e.reason, "Exception while applying the update received over XFR, skipping", "exception", Logging::Loggable("PDNSException")));
  }
  return true;
}

// As there can be multiple threads doing updates (due to config reloads), we use a multimap.
// The value contains the actual thread id that owns the struct.

static LockGuarded<std::multimap<DNSName, RPZWaiter&>> condVars;

// Notify all threads trakcing the RPZ name
bool notifyRPZTracker(const DNSName& name)
{
  auto lock = condVars.lock();
  auto [start, end] = lock->equal_range(name);
  if (start == end) {
    // Did not find any thread tracking that RPZ name
    return false;
  }
  while (start != end) {
    start->second.stop = true;
    start->second.condVar.notify_one();
    ++start;
  }
  return true;
}

void RPZIXFRTracker(RPZTrackerParams params, uint64_t configGeneration)
{
  setThreadName("rec/rpzixfr");
  bool isPreloaded = params.soaRecordContent != nullptr;
  auto logger = g_slog->withName("rpz");
  RPZWaiter waiter(std::this_thread::get_id());

  /* we can _never_ modify this zone directly, we need to do a full copy then replace the existing zone */
  std::shared_ptr<DNSFilterEngine::Zone> oldZone = g_luaconfs.getLocal()->dfe.getZone(params.zoneIdx);
  if (!oldZone) {
    SLOG(g_log << Logger::Error << "Unable to retrieve RPZ zone with index " << params.zoneIdx << " from the configuration, exiting" << endl,
         logger->error(Logr::Error, "Unable to retrieve RPZ zone from configuration", "index", Logging::Loggable(params.zoneIdx)));
    return;
  }

  // If oldZone failed to load its getRefresh() returns 0, protect against that
  uint32_t refresh = std::max(params.refreshFromConf != 0 ? params.refreshFromConf : oldZone->getRefresh(), 10U);
  DNSName zoneName = oldZone->getDomain();
  std::string polName = !oldZone->getName().empty() ? oldZone->getName() : zoneName.toStringNoDot();

  // Now that we know the name, set it in the logger
  logger = logger->withValues("zone", Logging::Loggable(zoneName));

  {
    auto lock = condVars.lock();
    lock->emplace(zoneName, waiter);
  }
  preloadRPZFIle(params, zoneName, oldZone, refresh, polName, waiter, logger);

  bool skipRefreshDelay = isPreloaded;

  while (RPZTrackerIteration(params, zoneName, oldZone, refresh, polName, skipRefreshDelay, configGeneration, waiter, logger)) {
    // empty
  }

  // Zap our (and only our) RPZWaiter struct out of the multimap
  auto lock = condVars.lock();
  auto [start, end] = lock->equal_range(zoneName);
  while (start != end) {
    if (start->second.id == std::this_thread::get_id()) {
      start = lock->erase(start);
    }
    else {
      ++start;
    }
  }
}