Merge pull request #5543 from rgacogne/web-auto-ptr

[thirdparty/pdns.git] / pdns / pdns_recursor.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.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <netdb.h>
#include <sys/stat.h>
#include <unistd.h>

#include "ws-recursor.hh"
#include <pthread.h>
#include "recpacketcache.hh"
#include "utility.hh"
#include "dns_random.hh"
#ifdef HAVE_LIBSODIUM
#include <sodium.h>
#endif
#include "opensslsigners.hh"
#include <iostream>
#include <errno.h>
#include <boost/static_assert.hpp>
#include <map>
#include <set>
#include "recursor_cache.hh"
#include "cachecleaner.hh"
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include "misc.hh"
#include "mtasker.hh"
#include <utility>
#include "arguments.hh"
#include "syncres.hh"
#include <fcntl.h>
#include <fstream>
#include "sortlist.hh"
extern SortList g_sortlist;
#include "sstuff.hh"
#include <boost/tuple/tuple.hpp>
#include <boost/tuple/tuple_comparison.hpp>
#include <boost/shared_array.hpp>
#include <boost/function.hpp>
#include <boost/algorithm/string.hpp>
#ifdef MALLOC_TRACE
#include "malloctrace.hh"
#endif
#include <netinet/tcp.h>
#include "dnsparser.hh"
#include "dnswriter.hh"
#include "dnsrecords.hh"
#include "zoneparser-tng.hh"
#include "rec_channel.hh"
#include "logger.hh"
#include "iputils.hh"
#include "mplexer.hh"
#include "config.h"
#include "lua-recursor4.hh"
#include "version.hh"
#include "responsestats.hh"
#include "secpoll-recursor.hh"
#include "dnsname.hh"
#include "filterpo.hh"
#include "rpzloader.hh"
#include "validate-recursor.hh"
#include "rec-lua-conf.hh"
#include "ednsoptions.hh"
#include "gettime.hh"

#include "rec-protobuf.hh"
#include "rec-snmp.hh"

#ifdef HAVE_SYSTEMD
#include <systemd/sd-daemon.h>
#endif

#include "namespaces.hh"

typedef map<ComboAddress, uint32_t, ComboAddress::addressOnlyLessThan> tcpClientCounts_t;

static thread_local std::shared_ptr<RecursorLua4> t_pdl;
static thread_local unsigned int t_id;
static thread_local std::shared_ptr<Regex> t_traceRegex;
static thread_local std::unique_ptr<tcpClientCounts_t> t_tcpClientCounts;

thread_local std::unique_ptr<MT_t> MT; // the big MTasker
thread_local std::unique_ptr<MemRecursorCache> t_RC;
thread_local std::unique_ptr<RecursorPacketCache> t_packetCache;
thread_local FDMultiplexer* t_fdm{nullptr};
thread_local std::unique_ptr<addrringbuf_t> t_remotes, t_servfailremotes, t_largeanswerremotes;
thread_local std::unique_ptr<boost::circular_buffer<pair<DNSName, uint16_t> > > t_queryring, t_servfailqueryring;
thread_local std::shared_ptr<NetmaskGroup> t_allowFrom;
#ifdef HAVE_PROTOBUF
thread_local std::unique_ptr<boost::uuids::random_generator> t_uuidGenerator;
#endif
__thread struct timeval g_now; // timestamp, updated (too) frequently

// for communicating with our threads
struct ThreadPipeSet
{
  int writeToThread;
  int readToThread;
  int writeFromThread;
  int readFromThread;
};

typedef vector<int> tcpListenSockets_t;
typedef map<int, ComboAddress> listenSocketsAddresses_t; // is shared across all threads right now
typedef vector<pair<int, function< void(int, any&) > > > deferredAdd_t;

static const ComboAddress g_local4("0.0.0.0"), g_local6("::");
static vector<ThreadPipeSet> g_pipes; // effectively readonly after startup
static tcpListenSockets_t g_tcpListenSockets;   // shared across threads, but this is fine, never written to from a thread. All threads listen on all sockets
static listenSocketsAddresses_t g_listenSocketsAddresses; // is shared across all threads right now
static std::unordered_map<unsigned int, deferredAdd_t> deferredAdds;
static set<int> g_fromtosockets; // listen sockets that use 'sendfromto()' mechanism
static vector<ComboAddress> g_localQueryAddresses4, g_localQueryAddresses6;
static AtomicCounter counter;
static std::shared_ptr<SyncRes::domainmap_t> g_initialDomainMap; // new threads needs this to be setup
static std::shared_ptr<NetmaskGroup> g_initialAllowFrom; // new thread needs to be setup with this
static size_t g_tcpMaxQueriesPerConn;
static uint64_t g_latencyStatSize;
static uint32_t g_disthashseed;
static unsigned int g_maxTCPPerClient;
static unsigned int g_networkTimeoutMsec;
static unsigned int g_maxMThreads;
static unsigned int g_numWorkerThreads;
static int g_tcpTimeout;
static uint16_t g_udpTruncationThreshold;
static std::atomic<bool> statsWanted;
static std::atomic<bool> g_quiet;
static bool g_logCommonErrors;
static bool g_anyToTcp;
static bool g_lowercaseOutgoing;
static bool g_weDistributeQueries; // if true, only 1 thread listens on the incoming query sockets
static bool g_reusePort{false};
static bool g_useOneSocketPerThread;
static bool g_gettagNeedsEDNSOptions{false};
static time_t g_statisticsInterval;
static bool g_useIncomingECS;

RecursorControlChannel s_rcc; // only active in thread 0
RecursorStats g_stats;
string s_programname="pdns_recursor";
string s_pidfname;
unsigned int g_numThreads;
uint16_t g_outgoingEDNSBufsize;

#define LOCAL_NETS "127.0.0.0/8, 10.0.0.0/8, 100.64.0.0/10, 169.254.0.0/16, 192.168.0.0/16, 172.16.0.0/12, ::1/128, fc00::/7, fe80::/10"
// Bad Nets taken from both:
// http://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
// and
// http://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
// where such a network may not be considered a valid destination
#define BAD_NETS   "0.0.0.0/8, 192.0.0.0/24, 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24, 240.0.0.0/4, ::/96, ::ffff:0:0/96, 100::/64, 2001:db8::/32"
#define DONT_QUERY LOCAL_NETS ", " BAD_NETS

//! used to send information to a newborn mthread
struct DNSComboWriter {
  DNSComboWriter(const char* data, uint16_t len, const struct timeval& now) : d_mdp(true, data, len), d_now(now),
                                                                                                        d_tcp(false), d_socket(-1)
  {}
  MOADNSParser d_mdp;
  void setRemote(const ComboAddress* sa)
  {
    d_remote=*sa;
  }

  void setLocal(const ComboAddress& sa)
  {
    d_local=sa;
  }


  void setSocket(int sock)
  {
    d_socket=sock;
  }

  string getRemote() const
  {
    return d_remote.toString();
  }

  struct timeval d_now;
  ComboAddress d_remote, d_local;
#ifdef HAVE_PROTOBUF
  boost::uuids::uuid d_uuid;
  string d_requestorId;
#endif
  EDNSSubnetOpts d_ednssubnet;
  bool d_ecsFound{false};
  bool d_ecsParsed{false};
  bool d_tcp;
  int d_socket;
  unsigned int d_tag{0};
  uint32_t d_qhash{0};
  string d_query;
  shared_ptr<TCPConnection> d_tcpConnection;
  vector<pair<uint16_t, string> > d_ednsOpts;
  std::vector<std::string> d_policyTags;
  LuaContext::LuaObject d_data;
};

MT_t* getMT()
{
  return MT ? MT.get() : nullptr;
}

ArgvMap &arg()
{
  static ArgvMap theArg;
  return theArg;
}

unsigned int getRecursorThreadId()
{
  return t_id;
}

int getMTaskerTID()
{
  return MT->getTid();
}

static void handleTCPClientWritable(int fd, FDMultiplexer::funcparam_t& var);

// -1 is error, 0 is timeout, 1 is success
int asendtcp(const string& data, Socket* sock)
{
  PacketID pident;
  pident.sock=sock;
  pident.outMSG=data;

  t_fdm->addWriteFD(sock->getHandle(), handleTCPClientWritable, pident);
  string packet;

  int ret=MT->waitEvent(pident, &packet, g_networkTimeoutMsec);

  if(!ret || ret==-1) { // timeout
    t_fdm->removeWriteFD(sock->getHandle());
  }
  else if(packet.size() !=data.size()) { // main loop tells us what it sent out, or empty in case of an error
    return -1;
  }
  return ret;
}

static void handleTCPClientReadable(int fd, FDMultiplexer::funcparam_t& var);

// -1 is error, 0 is timeout, 1 is success
int arecvtcp(string& data, size_t len, Socket* sock, bool incompleteOkay)
{
  data.clear();
  PacketID pident;
  pident.sock=sock;
  pident.inNeeded=len;
  pident.inIncompleteOkay=incompleteOkay;
  t_fdm->addReadFD(sock->getHandle(), handleTCPClientReadable, pident);

  int ret=MT->waitEvent(pident,&data, g_networkTimeoutMsec);
  if(!ret || ret==-1) { // timeout
    t_fdm->removeReadFD(sock->getHandle());
  }
  else if(data.empty()) {// error, EOF or other
    return -1;
  }

  return ret;
}

static void handleGenUDPQueryResponse(int fd, FDMultiplexer::funcparam_t& var)
{
  PacketID pident=*any_cast<PacketID>(&var);
  char resp[512];
  ssize_t ret=recv(fd, resp, sizeof(resp), 0);
  t_fdm->removeReadFD(fd);
  if(ret >= 0) {
    string data(resp, (size_t) ret);
    MT->sendEvent(pident, &data);
  }
  else {
    string empty;
    MT->sendEvent(pident, &empty);
    //    cerr<<"Had some kind of error: "<<ret<<", "<<strerror(errno)<<endl;
  }
}
string GenUDPQueryResponse(const ComboAddress& dest, const string& query)
{
  Socket s(dest.sin4.sin_family, SOCK_DGRAM);
  s.setNonBlocking();
  ComboAddress local = getQueryLocalAddress(dest.sin4.sin_family, 0);
  
  s.bind(local);
  s.connect(dest);
  s.send(query);

  PacketID pident;
  pident.sock=&s;
  pident.type=0;
  t_fdm->addReadFD(s.getHandle(), handleGenUDPQueryResponse, pident);

  string data;
 
  int ret=MT->waitEvent(pident,&data, g_networkTimeoutMsec);
 
  if(!ret || ret==-1) { // timeout
    t_fdm->removeReadFD(s.getHandle());
  }
  else if(data.empty()) {// error, EOF or other
    // we could special case this
    return data;
  }
  return data;
}

//! pick a random query local address
ComboAddress getQueryLocalAddress(int family, uint16_t port)
{
  ComboAddress ret;
  if(family==AF_INET) {
    if(g_localQueryAddresses4.empty())
      ret = g_local4;
    else
      ret = g_localQueryAddresses4[dns_random(g_localQueryAddresses4.size())];
    ret.sin4.sin_port = htons(port);
  }
  else {
    if(g_localQueryAddresses6.empty())
      ret = g_local6;
    else
      ret = g_localQueryAddresses6[dns_random(g_localQueryAddresses6.size())];

    ret.sin6.sin6_port = htons(port);
  }
  return ret;
}

static void handleUDPServerResponse(int fd, FDMultiplexer::funcparam_t&);

static void setSocketBuffer(int fd, int optname, uint32_t size)
{
  uint32_t psize=0;
  socklen_t len=sizeof(psize);

  if(!getsockopt(fd, SOL_SOCKET, optname, (char*)&psize, &len) && psize > size) {
    L<<Logger::Error<<"Not decreasing socket buffer size from "<<psize<<" to "<<size<<endl;
    return;
  }

  if (setsockopt(fd, SOL_SOCKET, optname, (char*)&size, sizeof(size)) < 0 )
    L<<Logger::Error<<"Unable to raise socket buffer size to "<<size<<": "<<strerror(errno)<<endl;
}


static void setSocketReceiveBuffer(int fd, uint32_t size)
{
  setSocketBuffer(fd, SO_RCVBUF, size);
}

static void setSocketSendBuffer(int fd, uint32_t size)
{
  setSocketBuffer(fd, SO_SNDBUF, size);
}


// you can ask this class for a UDP socket to send a query from
// this socket is not yours, don't even think about deleting it
// but after you call 'returnSocket' on it, don't assume anything anymore
class UDPClientSocks
{
  unsigned int d_numsocks;
public:
  UDPClientSocks() : d_numsocks(0)
  {
  }

  typedef set<int> socks_t;
  socks_t d_socks;

  // returning -2 means: temporary OS error (ie, out of files), -1 means error related to remote
  int getSocket(const ComboAddress& toaddr, int* fd)
  {
    *fd=makeClientSocket(toaddr.sin4.sin_family);
    if(*fd < 0) // temporary error - receive exception otherwise
      return -2;

    if(connect(*fd, (struct sockaddr*)(&toaddr), toaddr.getSocklen()) < 0) {
      int err = errno;
      //      returnSocket(*fd);
      try {
        closesocket(*fd);
      }
      catch(const PDNSException& e) {
        L<<Logger::Error<<"Error closing UDP socket after connect() failed: "<<e.reason<<endl;
      }

      if(err==ENETUNREACH) // Seth "My Interfaces Are Like A Yo Yo" Arnold special
        return -2;
      return -1;
    }

    d_socks.insert(*fd);
    d_numsocks++;
    return 0;
  }

  void returnSocket(int fd)
  {
    socks_t::iterator i=d_socks.find(fd);
    if(i==d_socks.end()) {
      throw PDNSException("Trying to return a socket (fd="+std::to_string(fd)+") not in the pool");
    }
    returnSocketLocked(i);
  }

  // return a socket to the pool, or simply erase it
  void returnSocketLocked(socks_t::iterator& i)
  {
    if(i==d_socks.end()) {
      throw PDNSException("Trying to return a socket not in the pool");
    }
    try {
      t_fdm->removeReadFD(*i);
    }
    catch(FDMultiplexerException& e) {
      // we sometimes return a socket that has not yet been assigned to t_fdm
    }
    try {
      closesocket(*i);
    }
    catch(const PDNSException& e) {
      L<<Logger::Error<<"Error closing returned UDP socket: "<<e.reason<<endl;
    }

    d_socks.erase(i++);
    --d_numsocks;
  }

  // returns -1 for errors which might go away, throws for ones that won't
  static int makeClientSocket(int family)
  {
    int ret=socket(family, SOCK_DGRAM, 0 ); // turns out that setting CLO_EXEC and NONBLOCK from here is not a performance win on Linux (oddly enough)

    if(ret < 0 && errno==EMFILE) // this is not a catastrophic error
      return ret;

    if(ret<0)
      throw PDNSException("Making a socket for resolver (family = "+std::to_string(family)+"): "+stringerror());

    //    setCloseOnExec(ret); // we're not going to exec

    int tries=10;
    ComboAddress sin;
    while(--tries) {
      uint16_t port;

      if(tries==1)  // fall back to kernel 'random'
        port = 0;
      else
        port = 1025 + dns_random(64510);

      sin=getQueryLocalAddress(family, port); // does htons for us

      if (::bind(ret, (struct sockaddr *)&sin, sin.getSocklen()) >= 0)
        break;
    }
    if(!tries)
      throw PDNSException("Resolver binding to local query client socket on "+sin.toString()+": "+stringerror());

    setNonBlocking(ret);
    return ret;
  }
};

static thread_local std::unique_ptr<UDPClientSocks> t_udpclientsocks;

/* these two functions are used by LWRes */
// -2 is OS error, -1 is error that depends on the remote, > 0 is success
int asendto(const char *data, size_t len, int flags,
            const ComboAddress& toaddr, uint16_t id, const DNSName& domain, uint16_t qtype, int* fd)
{

  PacketID pident;
  pident.domain = domain;
  pident.remote = toaddr;
  pident.type = qtype;

  // see if there is an existing outstanding request we can chain on to, using partial equivalence function
  pair<MT_t::waiters_t::iterator, MT_t::waiters_t::iterator> chain=MT->d_waiters.equal_range(pident, PacketIDBirthdayCompare());

  for(; chain.first != chain.second; chain.first++) {
    if(chain.first->key.fd > -1) { // don't chain onto existing chained waiter!
      /*
      cerr<<"Orig: "<<pident.domain<<", "<<pident.remote.toString()<<", id="<<id<<endl;
      cerr<<"Had hit: "<< chain.first->key.domain<<", "<<chain.first->key.remote.toString()<<", id="<<chain.first->key.id
          <<", count="<<chain.first->key.chain.size()<<", origfd: "<<chain.first->key.fd<<endl;
      */
      chain.first->key.chain.insert(id); // we can chain
      *fd=-1;                            // gets used in waitEvent / sendEvent later on
      return 1;
    }
  }

  int ret=t_udpclientsocks->getSocket(toaddr, fd);
  if(ret < 0)
    return ret;

  pident.fd=*fd;
  pident.id=id;

  t_fdm->addReadFD(*fd, handleUDPServerResponse, pident);
  ret = send(*fd, data, len, 0);

  int tmp = errno;

  if(ret < 0)
    t_udpclientsocks->returnSocket(*fd);

  errno = tmp; // this is for logging purposes only
  return ret;
}

// -1 is error, 0 is timeout, 1 is success
int arecvfrom(char *data, size_t len, int flags, const ComboAddress& fromaddr, size_t *d_len,
              uint16_t id, const DNSName& domain, uint16_t qtype, int fd, struct timeval* now)
{
  static optional<unsigned int> nearMissLimit;
  if(!nearMissLimit)
    nearMissLimit=::arg().asNum("spoof-nearmiss-max");

  PacketID pident;
  pident.fd=fd;
  pident.id=id;
  pident.domain=domain;
  pident.type = qtype;
  pident.remote=fromaddr;

  string packet;
  int ret=MT->waitEvent(pident, &packet, g_networkTimeoutMsec, now);

  if(ret > 0) {
    if(packet.empty()) // means "error"
      return -1;

    *d_len=packet.size();
    memcpy(data,packet.c_str(),min(len,*d_len));
    if(*nearMissLimit && pident.nearMisses > *nearMissLimit) {
      L<<Logger::Error<<"Too many ("<<pident.nearMisses<<" > "<<*nearMissLimit<<") bogus answers for '"<<domain<<"' from "<<fromaddr.toString()<<", assuming spoof attempt."<<endl;
      g_stats.spoofCount++;
      return -1;
    }
  }
  else {
    if(fd >= 0)
      t_udpclientsocks->returnSocket(fd);
  }
  return ret;
}

static void writePid(void)
{
  if(!::arg().mustDo("write-pid"))
    return;
  ofstream of(s_pidfname.c_str(), std::ios_base::app);
  if(of)
    of<< Utility::getpid() <<endl;
  else
    L<<Logger::Error<<"Writing pid for "<<Utility::getpid()<<" to "<<s_pidfname<<" failed: "<<strerror(errno)<<endl;
}

TCPConnection::TCPConnection(int fd, const ComboAddress& addr) : d_remote(addr), d_fd(fd)
{
  ++s_currentConnections;
  (*t_tcpClientCounts)[d_remote]++;
}

TCPConnection::~TCPConnection()
{
  try {
    if(closesocket(d_fd) < 0)
      L<<Logger::Error<<"Error closing socket for TCPConnection"<<endl;
  }
  catch(const PDNSException& e) {
    L<<Logger::Error<<"Error closing TCPConnection socket: "<<e.reason<<endl;
  }

  if(t_tcpClientCounts->count(d_remote) && !(*t_tcpClientCounts)[d_remote]--)
    t_tcpClientCounts->erase(d_remote);
  --s_currentConnections;
}

AtomicCounter TCPConnection::s_currentConnections;

static void handleRunningTCPQuestion(int fd, FDMultiplexer::funcparam_t& var);

// the idea is, only do things that depend on the *response* here. Incoming accounting is on incoming.
static void updateResponseStats(int res, const ComboAddress& remote, unsigned int packetsize, const DNSName* query, uint16_t qtype)
{
  if(packetsize > 1000 && t_largeanswerremotes)
    t_largeanswerremotes->push_back(remote);
  switch(res) {
  case RCode::ServFail:
    if(t_servfailremotes) {
      t_servfailremotes->push_back(remote);
      if(query && t_servfailqueryring) // packet cache
	t_servfailqueryring->push_back(make_pair(*query, qtype));
    }
    g_stats.servFails++;
    break;
  case RCode::NXDomain:
    g_stats.nxDomains++;
    break;
  case RCode::NoError:
    g_stats.noErrors++;
    break;
  }
}

static string makeLoginfo(DNSComboWriter* dc)
try
{
  return "("+dc->d_mdp.d_qname.toLogString()+"/"+DNSRecordContent::NumberToType(dc->d_mdp.d_qtype)+" from "+(dc->d_remote.toString())+")";
}
catch(...)
{
  return "Exception making error message for exception";
}

#ifdef HAVE_PROTOBUF
static void protobufLogQuery(const std::shared_ptr<RemoteLogger>& logger, uint8_t maskV4, uint8_t maskV6, const boost::uuids::uuid& uniqueId, const ComboAddress& remote, const ComboAddress& local, const Netmask& ednssubnet, bool tcp, uint16_t id, size_t len, const DNSName& qname, uint16_t qtype, uint16_t qclass, const std::vector<std::string>& policyTags, const std::string& requestorId)
{
  Netmask requestorNM(remote, remote.sin4.sin_family == AF_INET ? maskV4 : maskV6);
  const ComboAddress& requestor = requestorNM.getMaskedNetwork();
  RecProtoBufMessage message(DNSProtoBufMessage::Query, uniqueId, &requestor, &local, qname, qtype, qclass, id, tcp, len);
  message.setEDNSSubnet(ednssubnet, ednssubnet.isIpv4() ? maskV4 : maskV6);
  message.setRequestorId(requestorId);

  if (!policyTags.empty()) {
    message.setPolicyTags(policyTags);
  }

//  cerr <<message.toDebugString()<<endl;
  std::string str;
  message.serialize(str);
  logger->queueData(str);
}

static void protobufLogResponse(const std::shared_ptr<RemoteLogger>& logger, const RecProtoBufMessage& message)
{
//  cerr <<message.toDebugString()<<endl;
  std::string str;
  message.serialize(str);
  logger->queueData(str);
}
#endif

/**
 * Chases the CNAME provided by the PolicyCustom RPZ policy.
 *
 * @param spoofed: The DNSRecord that was created by the policy, should already be added to ret
 * @param qtype: The QType of the original query
 * @param sr: A SyncRes
 * @param res: An integer that will contain the RCODE of the lookup we do
 * @param ret: A vector of DNSRecords where the result of the CNAME chase should be appended to
 */
static void handleRPZCustom(const DNSRecord& spoofed, const QType& qtype, SyncRes& sr, int& res, vector<DNSRecord>& ret)
{
  if (spoofed.d_type == QType::CNAME) {
    bool oldWantsRPZ = sr.getWantsRPZ();
    sr.setWantsRPZ(false);
    vector<DNSRecord> ans;
    res = sr.beginResolve(DNSName(spoofed.d_content->getZoneRepresentation()), qtype, 1, ans);
    for (const auto& rec : ans) {
      if(rec.d_place == DNSResourceRecord::ANSWER) {
        ret.push_back(rec);
      }
    }
    // Reset the RPZ state of the SyncRes
    sr.setWantsRPZ(oldWantsRPZ);
  }
}

static void startDoResolve(void *p)
{
  DNSComboWriter* dc=(DNSComboWriter *)p;
  try {
    if (t_queryring)
      t_queryring->push_back(make_pair(dc->d_mdp.d_qname, dc->d_mdp.d_qtype));

    uint16_t maxanswersize = dc->d_tcp ? 65535 : min(static_cast<uint16_t>(512), g_udpTruncationThreshold);
    EDNSOpts edo;
    bool haveEDNS=false;
    if(getEDNSOpts(dc->d_mdp, &edo)) {
      if(!dc->d_tcp) {
        /* rfc6891 6.2.3:
           "Values lower than 512 MUST be treated as equal to 512."
        */
        maxanswersize = min(static_cast<uint16_t>(edo.d_packetsize >= 512 ? edo.d_packetsize : 512), g_udpTruncationThreshold);
      }
      dc->d_ednsOpts = edo.d_options;
      haveEDNS=true;

      if (g_useIncomingECS && !dc->d_ecsParsed) {
        for (const auto& o : edo.d_options) {
          if (o.first == EDNSOptionCode::ECS) {
            dc->d_ecsFound = getEDNSSubnetOptsFromString(o.second, &dc->d_ednssubnet);
            break;
          }
        }
      }
    }
    /* perhaps there was no EDNS or no ECS but by now we looked */
    dc->d_ecsParsed = true;
    vector<DNSRecord> ret;
    vector<uint8_t> packet;

    auto luaconfsLocal = g_luaconfs.getLocal();
    // Used to tell syncres later on if we should apply NSDNAME and NSIP RPZ triggers for this query
    bool wantsRPZ(true);
    RecProtoBufMessage pbMessage(RecProtoBufMessage::Response);
#ifdef HAVE_PROTOBUF
    if (luaconfsLocal->protobufServer) {
      Netmask requestorNM(dc->d_remote, dc->d_remote.sin4.sin_family == AF_INET ? luaconfsLocal->protobufMaskV4 : luaconfsLocal->protobufMaskV6);
      const ComboAddress& requestor = requestorNM.getMaskedNetwork();
      pbMessage.update(dc->d_uuid, &requestor, &dc->d_local, dc->d_tcp, dc->d_mdp.d_header.id);
      pbMessage.setEDNSSubnet(dc->d_ednssubnet.source, dc->d_ednssubnet.source.isIpv4() ? luaconfsLocal->protobufMaskV4 : luaconfsLocal->protobufMaskV6);
      pbMessage.setQuestion(dc->d_mdp.d_qname, dc->d_mdp.d_qtype, dc->d_mdp.d_qclass);
    }
#endif /* HAVE_PROTOBUF */

    DNSPacketWriter pw(packet, dc->d_mdp.d_qname, dc->d_mdp.d_qtype, dc->d_mdp.d_qclass);

    pw.getHeader()->aa=0;
    pw.getHeader()->ra=1;
    pw.getHeader()->qr=1;
    pw.getHeader()->tc=0;
    pw.getHeader()->id=dc->d_mdp.d_header.id;
    pw.getHeader()->rd=dc->d_mdp.d_header.rd;
    pw.getHeader()->cd=dc->d_mdp.d_header.cd;

    // DO NOT MOVE THIS CODE UP - DNSPacketWriter needs to get the original-cased version
    if (g_lowercaseOutgoing)
      dc->d_mdp.d_qname = dc->d_mdp.d_qname.makeLowerCase();

    uint32_t minTTL=std::numeric_limits<uint32_t>::max();

    SyncRes sr(dc->d_now);
    bool DNSSECOK=false;
    if(t_pdl) {
      sr.setLuaEngine(t_pdl);
    }
    sr.d_requestor=dc->d_remote; // ECS needs this too
    if(g_dnssecmode != DNSSECMode::Off) {
      sr.setDoDNSSEC(true);

      // Does the requestor want DNSSEC records?
      if(edo.d_Z & EDNSOpts::DNSSECOK) {
        DNSSECOK=true;
        g_stats.dnssecQueries++;
      }
    } else {
      // Ignore the client-set CD flag
      pw.getHeader()->cd=0;
    }
#ifdef HAVE_PROTOBUF
    sr.setInitialRequestId(dc->d_uuid);
#endif
    if (g_useIncomingECS) {
      sr.setIncomingECSFound(dc->d_ecsFound);
      if (dc->d_ecsFound) {
        sr.setIncomingECS(dc->d_ednssubnet);
      }
    }

    bool tracedQuery=false; // we could consider letting Lua know about this too
    bool variableAnswer = false;
    bool shouldNotValidate = false;

    /* preresolve expects res (dq.rcode) to be set to RCode::NoError by default */
    int res = RCode::NoError;
    DNSFilterEngine::Policy appliedPolicy;
    DNSRecord spoofed;
    RecursorLua4::DNSQuestion dq(dc->d_remote, dc->d_local, dc->d_mdp.d_qname, dc->d_mdp.d_qtype, dc->d_tcp, variableAnswer, wantsRPZ);
    dq.ednsFlags = &edo.d_Z;
    dq.ednsOptions = &dc->d_ednsOpts;
    dq.tag = dc->d_tag;
    dq.discardedPolicies = &sr.d_discardedPolicies;
    dq.policyTags = &dc->d_policyTags;
    dq.appliedPolicy = &appliedPolicy;
    dq.currentRecords = &ret;
    dq.dh = &dc->d_mdp.d_header;
    dq.data = dc->d_data;
#ifdef HAVE_PROTOBUF
    dq.requestorId = dc->d_requestorId;
#endif

    if(dc->d_mdp.d_qtype==QType::ANY && !dc->d_tcp && g_anyToTcp) {
      pw.getHeader()->tc = 1;
      res = 0;
      variableAnswer = true;
      goto sendit;
    }

    if(t_traceRegex && t_traceRegex->match(dc->d_mdp.d_qname.toString())) {
      sr.setLogMode(SyncRes::Store);
      tracedQuery=true;
    }


    if(!g_quiet || tracedQuery) {
      L<<Logger::Warning<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] " << (dc->d_tcp ? "TCP " : "") << "question for '"<<dc->d_mdp.d_qname<<"|"
       <<DNSRecordContent::NumberToType(dc->d_mdp.d_qtype)<<"' from "<<dc->getRemote();
      if(!dc->d_ednssubnet.source.empty()) {
        L<<" (ecs "<<dc->d_ednssubnet.source.toString()<<")";
      }
      L<<endl;
    }

    sr.setId(MT->getTid());
    if(!dc->d_mdp.d_header.rd)
      sr.setCacheOnly();

    if (t_pdl) {
      t_pdl->prerpz(dq, res);
    }

    // Check if the query has a policy attached to it
    if (wantsRPZ) {
      appliedPolicy = luaconfsLocal->dfe.getQueryPolicy(dc->d_mdp.d_qname, dc->d_remote, sr.d_discardedPolicies);
    }

    // if there is a RecursorLua active, and it 'took' the query in preResolve, we don't launch beginResolve
    if(!t_pdl || !t_pdl->preresolve(dq, res)) {

      sr.setWantsRPZ(wantsRPZ);
      if(wantsRPZ) {
        switch(appliedPolicy.d_kind) {
          case DNSFilterEngine::PolicyKind::NoAction:
            break;
          case DNSFilterEngine::PolicyKind::Drop:
            g_stats.policyDrops++;
            g_stats.policyResults[appliedPolicy.d_kind]++;
            delete dc;
            dc=0;
            return; 
          case DNSFilterEngine::PolicyKind::NXDOMAIN:
            g_stats.policyResults[appliedPolicy.d_kind]++;
            res=RCode::NXDomain;
            goto haveAnswer;
          case DNSFilterEngine::PolicyKind::NODATA:
            g_stats.policyResults[appliedPolicy.d_kind]++;
            res=RCode::NoError;
            goto haveAnswer;
          case DNSFilterEngine::PolicyKind::Custom:
            g_stats.policyResults[appliedPolicy.d_kind]++;
            res=RCode::NoError;
            spoofed=appliedPolicy.getCustomRecord(dc->d_mdp.d_qname);
            ret.push_back(spoofed);
            handleRPZCustom(spoofed, QType(dc->d_mdp.d_qtype), sr, res, ret);
            goto haveAnswer;
          case DNSFilterEngine::PolicyKind::Truncate:
            if(!dc->d_tcp) {
              g_stats.policyResults[appliedPolicy.d_kind]++;
              res=RCode::NoError;	
              pw.getHeader()->tc=1;
              goto haveAnswer;
            }
            break;
        }
      }

      // Query got not handled for QNAME Policy reasons, now actually go out to find an answer
      try {
        res = sr.beginResolve(dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), dc->d_mdp.d_qclass, ret);
        shouldNotValidate = sr.wasOutOfBand();
      }
      catch(ImmediateServFailException &e) {
        if(g_logCommonErrors)
          L<<Logger::Notice<<"Sending SERVFAIL to "<<dc->getRemote()<<" during resolve of '"<<dc->d_mdp.d_qname<<"' because: "<<e.reason<<endl;
        res = RCode::ServFail;
      }

      // During lookup, an NSDNAME or NSIP trigger was hit in RPZ
      if (res == -2) { // XXX This block should be macro'd, it is repeated post-resolve.
        appliedPolicy = sr.d_appliedPolicy;
        g_stats.policyResults[appliedPolicy.d_kind]++;
        switch(appliedPolicy.d_kind) {
          case DNSFilterEngine::PolicyKind::NoAction: // This can never happen
            throw PDNSException("NoAction policy returned while a NSDNAME or NSIP trigger was hit");
          case DNSFilterEngine::PolicyKind::Drop:
            g_stats.policyDrops++;
            delete dc;
            dc=0;
            return;
          case DNSFilterEngine::PolicyKind::NXDOMAIN:
            ret.clear();
            res=RCode::NXDomain;
            goto haveAnswer;

          case DNSFilterEngine::PolicyKind::NODATA:
            ret.clear();
            res=RCode::NoError;
            goto haveAnswer;

          case DNSFilterEngine::PolicyKind::Truncate:
            if(!dc->d_tcp) {
              ret.clear();
              res=RCode::NoError;
              pw.getHeader()->tc=1;
              goto haveAnswer;
            }
            break;

          case DNSFilterEngine::PolicyKind::Custom:
            ret.clear();
            res=RCode::NoError;
            spoofed=appliedPolicy.getCustomRecord(dc->d_mdp.d_qname);
            ret.push_back(spoofed);
            handleRPZCustom(spoofed, QType(dc->d_mdp.d_qtype), sr, res, ret);
            goto haveAnswer;
        }
      }

      if (wantsRPZ) {
        appliedPolicy = luaconfsLocal->dfe.getPostPolicy(ret, sr.d_discardedPolicies);
      }

      if(t_pdl) {
        if(res == RCode::NoError) {
	        auto i=ret.cbegin();
                for(; i!= ret.cend(); ++i)
                  if(i->d_type == dc->d_mdp.d_qtype && i->d_place == DNSResourceRecord::ANSWER)
                          break;
                if(i == ret.cend() && t_pdl->nodata(dq, res))
                  shouldNotValidate = true;

	}
	else if(res == RCode::NXDomain && t_pdl->nxdomain(dq, res))
          shouldNotValidate = true;

	if(t_pdl->postresolve(dq, res))
          shouldNotValidate = true;
      }

      if (wantsRPZ) { //XXX This block is repeated, see above
        g_stats.policyResults[appliedPolicy.d_kind]++;
        switch(appliedPolicy.d_kind) {
          case DNSFilterEngine::PolicyKind::NoAction:
            break;
          case DNSFilterEngine::PolicyKind::Drop:
            g_stats.policyDrops++;
            delete dc;
            dc=0;
            return; 
          case DNSFilterEngine::PolicyKind::NXDOMAIN:
            ret.clear();
            res=RCode::NXDomain;
            goto haveAnswer;

          case DNSFilterEngine::PolicyKind::NODATA:
            ret.clear();
            res=RCode::NoError;
            goto haveAnswer;

          case DNSFilterEngine::PolicyKind::Truncate:
            if(!dc->d_tcp) {
              ret.clear();
              res=RCode::NoError;
              pw.getHeader()->tc=1;
              goto haveAnswer;
            }
            break;

          case DNSFilterEngine::PolicyKind::Custom:
            ret.clear();
            res=RCode::NoError;
            spoofed=appliedPolicy.getCustomRecord(dc->d_mdp.d_qname);
            ret.push_back(spoofed);
            handleRPZCustom(spoofed, QType(dc->d_mdp.d_qtype), sr, res, ret);
            goto haveAnswer;
        }
      }
    }
  haveAnswer:;
    if(res == PolicyDecision::DROP) {
      g_stats.policyDrops++;
      delete dc;
      dc=0;
      return;
    }
    if(tracedQuery || res == PolicyDecision::PASS || res == RCode::ServFail || pw.getHeader()->rcode == RCode::ServFail)
    { 
      string trace(sr.getTrace());
      if(!trace.empty()) {
        vector<string> lines;
        boost::split(lines, trace, boost::is_any_of("\n"));
        for(const string& line : lines) {
          if(!line.empty())
            L<<Logger::Warning<< line << endl;
        }
      }
    }

    if(res == PolicyDecision::PASS) {  // XXX what does this MEAN? Why servfail on PASS?
      pw.getHeader()->rcode=RCode::ServFail;
      // no commit here, because no record
      g_stats.servFails++;
    }
    else {
      pw.getHeader()->rcode=res;

      // Does the validation mode or query demand validation?
      if(!shouldNotValidate && (g_dnssecmode == DNSSECMode::ValidateAll || g_dnssecmode==DNSSECMode::ValidateForLog || ((dc->d_mdp.d_header.ad || DNSSECOK) && g_dnssecmode==DNSSECMode::Process))) {
        try {
          if(sr.doLog()) {
            L<<Logger::Warning<<"Starting validation of answer to "<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<" for "<<dc->d_remote.toStringWithPort()<<endl;
          }

          auto state = sr.getValidationState();

          if(state == Secure) {
            if(sr.doLog()) {
              L<<Logger::Warning<<"Answer to "<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<" for "<<dc->d_remote.toStringWithPort()<<" validates correctly"<<endl;
            }
            
            // Is the query source interested in the value of the ad-bit?
            if (dc->d_mdp.d_header.ad || DNSSECOK)
              pw.getHeader()->ad=1;
          }
          else if(state == Insecure) {
            if(sr.doLog()) {
              L<<Logger::Warning<<"Answer to "<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<" for "<<dc->d_remote.toStringWithPort()<<" validates as Insecure"<<endl;
            }
            
            pw.getHeader()->ad=0;
          }
          else if(state == Bogus) {
            if(g_dnssecLogBogus || sr.doLog() || g_dnssecmode == DNSSECMode::ValidateForLog) {
              L<<Logger::Warning<<"Answer to "<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<" for "<<dc->d_remote.toStringWithPort()<<" validates as Bogus"<<endl;
            }
            
            // Does the query or validation mode sending out a SERVFAIL on validation errors?
            if(!pw.getHeader()->cd && (g_dnssecmode == DNSSECMode::ValidateAll || dc->d_mdp.d_header.ad || DNSSECOK)) {
              if(sr.doLog()) {
                L<<Logger::Warning<<"Sending out SERVFAIL for "<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<" because recursor or query demands it for Bogus results"<<endl;
              }
              
              pw.getHeader()->rcode=RCode::ServFail;
              goto sendit;
            } else {
              if(sr.doLog()) {
                L<<Logger::Warning<<"Not sending out SERVFAIL for "<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<" Bogus validation since neither config nor query demands this"<<endl;
              }
            }
          }
        }
        catch(ImmediateServFailException &e) {
          if(g_logCommonErrors)
            L<<Logger::Notice<<"Sending SERVFAIL to "<<dc->getRemote()<<" during validation of '"<<dc->d_mdp.d_qname<<"|"<<QType(dc->d_mdp.d_qtype).getName()<<"' because: "<<e.reason<<endl;
          pw.getHeader()->rcode=RCode::ServFail;
          goto sendit;
        }
      }

      if(ret.size()) {
        orderAndShuffle(ret);
	if(auto sl = luaconfsLocal->sortlist.getOrderCmp(dc->d_remote)) {
	  sort(ret.begin(), ret.end(), *sl);
	  variableAnswer=true;
	}
      }
      if(haveEDNS)  {
	ret.push_back(makeOpt(edo.d_packetsize, 0, edo.d_Z));
      }

      bool needCommit = false;
      for(auto i=ret.cbegin(); i!=ret.cend(); ++i) {
        if( ! DNSSECOK &&
            ( i->d_type == QType::NSEC3 ||
              (
                ( i->d_type == QType::RRSIG || i->d_type==QType::NSEC ) &&
                (
                  ( dc->d_mdp.d_qtype != i->d_type &&  dc->d_mdp.d_qtype != QType::ANY ) ||
                  i->d_place != DNSResourceRecord::ANSWER
                )
              )
            )
          ) {
          continue;
        }

	pw.startRecord(i->d_name, i->d_type, i->d_ttl, i->d_class, i->d_place);
	if(i->d_type != QType::OPT) // their TTL ain't real
	  minTTL = min(minTTL, i->d_ttl);
	i->d_content->toPacket(pw);
	if(pw.size() > static_cast<size_t>(maxanswersize)) {
	  pw.rollback();
	  if(i->d_place==DNSResourceRecord::ANSWER)  // only truncate if we actually omitted parts of the answer
            {
              pw.getHeader()->tc=1;
              pw.truncate();
            }
	  goto sendit; // need to jump over pw.commit
	}
	needCommit = true;
#ifdef HAVE_PROTOBUF
        if(luaconfsLocal->protobufServer && (i->d_type == QType::A || i->d_type == QType::AAAA || i->d_type == QType::CNAME)) {
          pbMessage.addRR(*i);
        }
#endif
      }
      if(needCommit)
	pw.commit();
    }
  sendit:;

    g_rs.submitResponse(dc->d_mdp.d_qtype, packet.size(), !dc->d_tcp);
    updateResponseStats(res, dc->d_remote, packet.size(), &dc->d_mdp.d_qname, dc->d_mdp.d_qtype);
#ifdef HAVE_PROTOBUF
    if (luaconfsLocal->protobufServer && (!luaconfsLocal->protobufTaggedOnly || (appliedPolicy.d_name && !appliedPolicy.d_name->empty()) || !dc->d_policyTags.empty())) {
      pbMessage.setBytes(packet.size());
      pbMessage.setResponseCode(pw.getHeader()->rcode);
      if (appliedPolicy.d_name) {
        pbMessage.setAppliedPolicy(*appliedPolicy.d_name);
      }
      pbMessage.setPolicyTags(dc->d_policyTags);
      pbMessage.setQueryTime(dc->d_now.tv_sec, dc->d_now.tv_usec);
      pbMessage.setRequestorId(dq.requestorId);
      protobufLogResponse(luaconfsLocal->protobufServer, pbMessage);
    }
#endif
    if(!dc->d_tcp) {
      struct msghdr msgh;
      struct iovec iov;
      char cbuf[256];
      fillMSGHdr(&msgh, &iov, cbuf, 0, (char*)&*packet.begin(), packet.size(), &dc->d_remote);
      msgh.msg_control=NULL;

      if(g_fromtosockets.count(dc->d_socket)) {
	addCMsgSrcAddr(&msgh, cbuf, &dc->d_local, 0);
      }
      if(sendmsg(dc->d_socket, &msgh, 0) < 0 && g_logCommonErrors) 
        L<<Logger::Warning<<"Sending UDP reply to client "<<dc->d_remote.toStringWithPort()<<" failed with: "<<strerror(errno)<<endl;
      if(!SyncRes::s_nopacketcache && !variableAnswer && !sr.wasVariable() ) {
        t_packetCache->insertResponsePacket(dc->d_tag, dc->d_qhash, dc->d_mdp.d_qname, dc->d_mdp.d_qtype, dc->d_mdp.d_qclass,
                                            string((const char*)&*packet.begin(), packet.size()),
                                            g_now.tv_sec,
                                            pw.getHeader()->rcode == RCode::ServFail ? SyncRes::s_packetcacheservfailttl :
                                            min(minTTL,SyncRes::s_packetcachettl),
                                            &pbMessage);
      }
      //      else cerr<<"Not putting in packet cache: "<<sr.wasVariable()<<endl;
    }
    else {
      char buf[2];
      buf[0]=packet.size()/256;
      buf[1]=packet.size()%256;

      Utility::iovec iov[2];

      iov[0].iov_base=(void*)buf;              iov[0].iov_len=2;
      iov[1].iov_base=(void*)&*packet.begin(); iov[1].iov_len = packet.size();

      int wret=Utility::writev(dc->d_socket, iov, 2);
      bool hadError=true;

      if(wret == 0)
        L<<Logger::Error<<"EOF writing TCP answer to "<<dc->getRemote()<<endl;
      else if(wret < 0 )
        L<<Logger::Error<<"Error writing TCP answer to "<<dc->getRemote()<<": "<< strerror(errno) <<endl;
      else if((unsigned int)wret != 2 + packet.size())
        L<<Logger::Error<<"Oops, partial answer sent to "<<dc->getRemote()<<" for "<<dc->d_mdp.d_qname<<" (size="<< (2 + packet.size()) <<", sent "<<wret<<")"<<endl;
      else
        hadError=false;

      // update tcp connection status, either by closing or moving to 'BYTE0'

      if(hadError) {
        // no need to remove us from FDM, we weren't there
        dc->d_socket = -1;
      }
      else {
        dc->d_tcpConnection->queriesCount++;
        if (g_tcpMaxQueriesPerConn && dc->d_tcpConnection->queriesCount >= g_tcpMaxQueriesPerConn) {
          dc->d_socket = -1;
        }
        else {
          dc->d_tcpConnection->state=TCPConnection::BYTE0;
          Utility::gettimeofday(&g_now, 0); // needs to be updated
          t_fdm->addReadFD(dc->d_socket, handleRunningTCPQuestion, dc->d_tcpConnection);
          t_fdm->setReadTTD(dc->d_socket, g_now, g_tcpTimeout);
        }
      }
    }

    if(!g_quiet) {
      L<<Logger::Error<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] answer to "<<(dc->d_mdp.d_header.rd?"":"non-rd ")<<"question '"<<dc->d_mdp.d_qname<<"|"<<DNSRecordContent::NumberToType(dc->d_mdp.d_qtype);
      L<<"': "<<ntohs(pw.getHeader()->ancount)<<" answers, "<<ntohs(pw.getHeader()->arcount)<<" additional, took "<<sr.d_outqueries<<" packets, "<<
	sr.d_totUsec/1000.0<<" ms, "<<
	sr.d_throttledqueries<<" throttled, "<<sr.d_timeouts<<" timeouts, "<<sr.d_tcpoutqueries<<" tcp connections, rcode="<<res<<endl;
    }

    sr.d_outqueries ? t_RC->cacheMisses++ : t_RC->cacheHits++;
    float spent=makeFloat(sr.getNow()-dc->d_now);
    if(spent < 0.001)
      g_stats.answers0_1++;
    else if(spent < 0.010)
      g_stats.answers1_10++;
    else if(spent < 0.1)
      g_stats.answers10_100++;
    else if(spent < 1.0)
      g_stats.answers100_1000++;
    else
      g_stats.answersSlow++;

    uint64_t newLat=(uint64_t)(spent*1000000);
    newLat = min(newLat,(uint64_t)(((uint64_t) g_networkTimeoutMsec)*1000)); // outliers of several minutes exist..
    g_stats.avgLatencyUsec=(1-1.0/g_latencyStatSize)*g_stats.avgLatencyUsec + (float)newLat/g_latencyStatSize;
    // no worries, we do this for packet cache hits elsewhere
    //    cout<<dc->d_mdp.d_qname<<"\t"<<MT->getUsec()<<"\t"<<sr.d_outqueries<<endl;
    delete dc;
    dc=0;
  }
  catch(PDNSException &ae) {
    L<<Logger::Error<<"startDoResolve problem "<<makeLoginfo(dc)<<": "<<ae.reason<<endl;
    delete dc;
  }
  catch(MOADNSException& e) {
    L<<Logger::Error<<"DNS parser error "<<makeLoginfo(dc) <<": "<<dc->d_mdp.d_qname<<", "<<e.what()<<endl;
    delete dc;
  }
  catch(std::exception& e) {
    L<<Logger::Error<<"STL error "<< makeLoginfo(dc)<<": "<<e.what();

    // Luawrapper nests the exception from Lua, so we unnest it here
    try {
        std::rethrow_if_nested(e);
    } catch(const std::exception& e) {
        L<<". Extra info: "<<e.what();
    } catch(...) {}

    L<<endl;
    delete dc;
  }
  catch(...) {
    L<<Logger::Error<<"Any other exception in a resolver context "<< makeLoginfo(dc) <<endl;
  }

  g_stats.maxMThreadStackUsage = max(MT->getMaxStackUsage(), g_stats.maxMThreadStackUsage);
}

static void makeControlChannelSocket(int processNum=-1)
{
  string sockname=::arg()["socket-dir"]+"/"+s_programname;
  if(processNum >= 0)
    sockname += "."+std::to_string(processNum);
  sockname+=".controlsocket";
  s_rcc.listen(sockname);

  int sockowner = -1;
  int sockgroup = -1;

  if (!::arg().isEmpty("socket-group"))
    sockgroup=::arg().asGid("socket-group");
  if (!::arg().isEmpty("socket-owner"))
    sockowner=::arg().asUid("socket-owner");

  if (sockgroup > -1 || sockowner > -1) {
    if(chown(sockname.c_str(), sockowner, sockgroup) < 0) {
      unixDie("Failed to chown control socket");
    }
  }

  // do mode change if socket-mode is given
  if(!::arg().isEmpty("socket-mode")) {
    mode_t sockmode=::arg().asMode("socket-mode");
    if(chmod(sockname.c_str(), sockmode) < 0) {
      unixDie("Failed to chmod control socket");
    }
  }
}

static bool getQNameAndSubnet(const std::string& question, DNSName* dnsname, uint16_t* qtype, uint16_t* qclass, EDNSSubnetOpts* ednssubnet, std::map<uint16_t, EDNSOptionView>* options)
{
  bool found = false;
  const struct dnsheader* dh = (struct dnsheader*)question.c_str();
  size_t questionLen = question.length();
  unsigned int consumed=0;
  *dnsname=DNSName(question.c_str(), questionLen, sizeof(dnsheader), false, qtype, qclass, &consumed);

  size_t pos= sizeof(dnsheader)+consumed+4;
  /* at least OPT root label (1), type (2), class (2) and ttl (4) + OPT RR rdlen (2)
     = 11 */
  if(ntohs(dh->arcount) == 1 && questionLen > pos + 11) { // this code can extract one (1) EDNS Subnet option
    /* OPT root label (1) followed by type (2) */
    if(question.at(pos)==0 && question.at(pos+1)==0 && question.at(pos+2)==QType::OPT) {
      if (!options) {
        char* ecsStart = nullptr;
        size_t ecsLen = 0;
        int res = getEDNSOption((char*)question.c_str()+pos+9, questionLen - pos - 9, EDNSOptionCode::ECS, &ecsStart, &ecsLen);
        if (res == 0 && ecsLen > 4) {
          EDNSSubnetOpts eso;
          if(getEDNSSubnetOptsFromString(ecsStart + 4, ecsLen - 4, &eso)) {
            *ednssubnet=eso;
            found = true;
          }
        }
      }
      else {
        int res = getEDNSOptions((char*)question.c_str()+pos+9, questionLen - pos - 9, *options);
        if (res == 0) {
          const auto& it = options->find(EDNSOptionCode::ECS);
          if (it != options->end() && it->second.content != nullptr && it->second.size > 0) {
            EDNSSubnetOpts eso;
            if(getEDNSSubnetOptsFromString(it->second.content, it->second.size, &eso)) {
              *ednssubnet=eso;
              found = true;
            }
          }
        }
      }
    }
  }
  return found;
}

static void handleRunningTCPQuestion(int fd, FDMultiplexer::funcparam_t& var)
{
  shared_ptr<TCPConnection> conn=any_cast<shared_ptr<TCPConnection> >(var);

  if(conn->state==TCPConnection::BYTE0) {
    ssize_t bytes=recv(conn->getFD(), conn->data, 2, 0);
    if(bytes==1)
      conn->state=TCPConnection::BYTE1;
    if(bytes==2) {
      conn->qlen=(((unsigned char)conn->data[0]) << 8)+ (unsigned char)conn->data[1];
      conn->bytesread=0;
      conn->state=TCPConnection::GETQUESTION;
    }
    if(!bytes || bytes < 0) {
      t_fdm->removeReadFD(fd);
      return;
    }
  }
  else if(conn->state==TCPConnection::BYTE1) {
    ssize_t bytes=recv(conn->getFD(), conn->data+1, 1, 0);
    if(bytes==1) {
      conn->state=TCPConnection::GETQUESTION;
      conn->qlen=(((unsigned char)conn->data[0]) << 8)+ (unsigned char)conn->data[1];
      conn->bytesread=0;
    }
    if(!bytes || bytes < 0) {
      if(g_logCommonErrors)
        L<<Logger::Error<<"TCP client "<< conn->d_remote.toString() <<" disconnected after first byte"<<endl;
      t_fdm->removeReadFD(fd);
      return;
    }
  }
  else if(conn->state==TCPConnection::GETQUESTION) {
    ssize_t bytes=recv(conn->getFD(), conn->data + conn->bytesread, conn->qlen - conn->bytesread, 0);
    if(!bytes || bytes < 0 || bytes > std::numeric_limits<std::uint16_t>::max()) {
      L<<Logger::Error<<"TCP client "<< conn->d_remote.toString() <<" disconnected while reading question body"<<endl;
      t_fdm->removeReadFD(fd);
      return;
    }
    conn->bytesread+=(uint16_t)bytes;
    if(conn->bytesread==conn->qlen) {
      t_fdm->removeReadFD(fd); // should no longer awake ourselves when there is data to read

      DNSComboWriter* dc=nullptr;
      try {
        dc=new DNSComboWriter(conn->data, conn->qlen, g_now);
      }
      catch(MOADNSException &mde) {
        g_stats.clientParseError++;
        if(g_logCommonErrors)
          L<<Logger::Error<<"Unable to parse packet from TCP client "<< conn->d_remote.toString() <<endl;
        return;
      }
      dc->d_tcpConnection = conn; // carry the torch
      dc->setSocket(conn->getFD()); // this is the only time a copy is made of the actual fd
      dc->d_tcp=true;
      dc->setRemote(&conn->d_remote);
      ComboAddress dest;
      memset(&dest, 0, sizeof(dest));
      dest.sin4.sin_family = conn->d_remote.sin4.sin_family;
      socklen_t len = dest.getSocklen();
      getsockname(conn->getFD(), (sockaddr*)&dest, &len); // if this fails, we're ok with it
      dc->setLocal(dest);
      DNSName qname;
      uint16_t qtype=0;
      uint16_t qclass=0;
      bool needECS = false;
      string requestorId;
#ifdef HAVE_PROTOBUF
      auto luaconfsLocal = g_luaconfs.getLocal();
      if (luaconfsLocal->protobufServer) {
        needECS = true;
      }
#endif

      if(needECS || (t_pdl && t_pdl->d_gettag)) {

        try {
          std::map<uint16_t, EDNSOptionView> ednsOptions;
          dc->d_ecsParsed = true;
          dc->d_ecsFound = getQNameAndSubnet(std::string(conn->data, conn->qlen), &qname, &qtype, &qclass, &dc->d_ednssubnet, g_gettagNeedsEDNSOptions ? &ednsOptions : nullptr);

          if(t_pdl && t_pdl->d_gettag) {
            try {
              dc->d_tag = t_pdl->gettag(conn->d_remote, dc->d_ednssubnet.source, dest, qname, qtype, &dc->d_policyTags, dc->d_data, ednsOptions, true, requestorId);
            }
            catch(std::exception& e)  {
              if(g_logCommonErrors)
                L<<Logger::Warning<<"Error parsing a query packet qname='"<<qname<<"' for tag determination, setting tag=0: "<<e.what()<<endl;
            }
          }
        }
        catch(std::exception& e)
        {
          if(g_logCommonErrors)
            L<<Logger::Warning<<"Error parsing a query packet for tag determination, setting tag=0: "<<e.what()<<endl;
        }
      }
#ifdef HAVE_PROTOBUF
      if(luaconfsLocal->protobufServer || luaconfsLocal->outgoingProtobufServer) {
        dc->d_requestorId = requestorId;
        dc->d_uuid = (*t_uuidGenerator)();
      }

      if(luaconfsLocal->protobufServer) {
        try {
          const struct dnsheader* dh = (const struct dnsheader*) conn->data;

          if (!luaconfsLocal->protobufTaggedOnly) {
            protobufLogQuery(luaconfsLocal->protobufServer, luaconfsLocal->protobufMaskV4, luaconfsLocal->protobufMaskV6, dc->d_uuid, conn->d_remote, dest, dc->d_ednssubnet.source, true, dh->id, conn->qlen, qname, qtype, qclass, dc->d_policyTags, dc->d_requestorId);
          }
        }
        catch(std::exception& e) {
          if(g_logCommonErrors)
            L<<Logger::Warning<<"Error parsing a TCP query packet for edns subnet: "<<e.what()<<endl;
        }
      }
#endif
      if(dc->d_mdp.d_header.qr) {
        delete dc;
        g_stats.ignoredCount++;
        L<<Logger::Error<<"Ignoring answer from TCP client "<< conn->d_remote.toString() <<" on server socket!"<<endl;
        return;
      }
      if(dc->d_mdp.d_header.opcode) {
        delete dc;
        g_stats.ignoredCount++;
        L<<Logger::Error<<"Ignoring non-query opcode from TCP client "<< conn->d_remote.toString() <<" on server socket!"<<endl;
        return;
      }
      else {
        ++g_stats.qcounter;
        ++g_stats.tcpqcounter;
        MT->makeThread(startDoResolve, dc); // deletes dc, will set state to BYTE0 again
        return;
      }
    }
  }
}

//! Handle new incoming TCP connection
static void handleNewTCPQuestion(int fd, FDMultiplexer::funcparam_t& )
{
  ComboAddress addr;
  socklen_t addrlen=sizeof(addr);
  int newsock=accept(fd, (struct sockaddr*)&addr, &addrlen);
  if(newsock>=0) {
    if(MT->numProcesses() > g_maxMThreads) {
      g_stats.overCapacityDrops++;
      try {
        closesocket(newsock);
      }
      catch(const PDNSException& e) {
        L<<Logger::Error<<"Error closing TCP socket after an over capacity drop: "<<e.reason<<endl;
      }
      return;
    }

    if(t_remotes)
      t_remotes->push_back(addr);
    if(t_allowFrom && !t_allowFrom->match(&addr)) {
      if(!g_quiet)
        L<<Logger::Error<<"["<<MT->getTid()<<"] dropping TCP query from "<<addr.toString()<<", address not matched by allow-from"<<endl;

      g_stats.unauthorizedTCP++;
      try {
        closesocket(newsock);
      }
      catch(const PDNSException& e) {
        L<<Logger::Error<<"Error closing TCP socket after an ACL drop: "<<e.reason<<endl;
      }
      return;
    }
    if(g_maxTCPPerClient && t_tcpClientCounts->count(addr) && (*t_tcpClientCounts)[addr] >= g_maxTCPPerClient) {
      g_stats.tcpClientOverflow++;
      try {
        closesocket(newsock); // don't call TCPConnection::closeAndCleanup here - did not enter it in the counts yet!
      }
      catch(const PDNSException& e) {
        L<<Logger::Error<<"Error closing TCP socket after an overflow drop: "<<e.reason<<endl;
      }
      return;
    }

    setNonBlocking(newsock);
    std::shared_ptr<TCPConnection> tc = std::make_shared<TCPConnection>(newsock, addr);
    tc->state=TCPConnection::BYTE0;

    t_fdm->addReadFD(tc->getFD(), handleRunningTCPQuestion, tc);

    struct timeval now;
    Utility::gettimeofday(&now, 0);
    t_fdm->setReadTTD(tc->getFD(), now, g_tcpTimeout);
  }
}

static string* doProcessUDPQuestion(const std::string& question, const ComboAddress& fromaddr, const ComboAddress& destaddr, struct timeval tv, int fd)
{
  gettimeofday(&g_now, 0);
  struct timeval diff = g_now - tv;
  double delta=(diff.tv_sec*1000 + diff.tv_usec/1000.0);

  if(tv.tv_sec && delta > 1000.0) {
    g_stats.tooOldDrops++;
    return 0;
  }

  ++g_stats.qcounter;
  if(fromaddr.sin4.sin_family==AF_INET6)
     g_stats.ipv6qcounter++;

  string response;
  const struct dnsheader* dh = (struct dnsheader*)question.c_str();
  unsigned int ctag=0;
  uint32_t qhash = 0;
  bool needECS = false;
  std::vector<std::string> policyTags;
  LuaContext::LuaObject data;
  string requestorId;
#ifdef HAVE_PROTOBUF
  boost::uuids::uuid uniqueId;
  auto luaconfsLocal = g_luaconfs.getLocal();
  if (luaconfsLocal->protobufServer) {
    uniqueId = (*t_uuidGenerator)();
    needECS = true;
  } else if (luaconfsLocal->outgoingProtobufServer) {
    uniqueId = (*t_uuidGenerator)();
  }
#endif
  EDNSSubnetOpts ednssubnet;
  bool ecsFound = false;
  bool ecsParsed = false;
  try {
    DNSName qname;
    uint16_t qtype=0;
    uint16_t qclass=0;
    uint32_t age;
    bool qnameParsed=false;
#ifdef MALLOC_TRACE
    /*
    static uint64_t last=0;
    if(!last)
      g_mtracer->clearAllocators();
    cout<<g_mtracer->getAllocs()-last<<" "<<g_mtracer->getNumOut()<<" -- BEGIN TRACE"<<endl;
    last=g_mtracer->getAllocs();
    cout<<g_mtracer->topAllocatorsString()<<endl;
    g_mtracer->clearAllocators();
    */
#endif

    if(needECS || (t_pdl && t_pdl->d_gettag)) {
      try {
        std::map<uint16_t, EDNSOptionView> ednsOptions;
        ecsFound = getQNameAndSubnet(question, &qname, &qtype, &qclass, &ednssubnet, g_gettagNeedsEDNSOptions ? &ednsOptions : nullptr);
        qnameParsed = true;
        ecsParsed = true;

        if(t_pdl && t_pdl->d_gettag) {
          try {
            ctag=t_pdl->gettag(fromaddr, ednssubnet.source, destaddr, qname, qtype, &policyTags, data, ednsOptions, false, requestorId);
          }
          catch(std::exception& e)  {
            if(g_logCommonErrors)
              L<<Logger::Warning<<"Error parsing a query packet qname='"<<qname<<"' for tag determination, setting tag=0: "<<e.what()<<endl;
          }
        }
      }
      catch(std::exception& e)
      {
        if(g_logCommonErrors)
          L<<Logger::Warning<<"Error parsing a query packet for tag determination, setting tag=0: "<<e.what()<<endl;
      }
    }

    bool cacheHit = false;
    RecProtoBufMessage pbMessage(DNSProtoBufMessage::DNSProtoBufMessageType::Response);
#ifdef HAVE_PROTOBUF
    if(luaconfsLocal->protobufServer) {
      if (!luaconfsLocal->protobufTaggedOnly || !policyTags.empty()) {
        protobufLogQuery(luaconfsLocal->protobufServer, luaconfsLocal->protobufMaskV4, luaconfsLocal->protobufMaskV6, uniqueId, fromaddr, destaddr, ednssubnet.source, false, dh->id, question.size(), qname, qtype, qclass, policyTags, requestorId);
      }
    }
#endif /* HAVE_PROTOBUF */

    if (qnameParsed) {
      cacheHit = (!SyncRes::s_nopacketcache && t_packetCache->getResponsePacket(ctag, question, qname, qtype, qclass, g_now.tv_sec, &response, &age, &qhash, &pbMessage));
    }
    else {
      cacheHit = (!SyncRes::s_nopacketcache && t_packetCache->getResponsePacket(ctag, question, g_now.tv_sec, &response, &age, &qhash, &pbMessage));
    }

    if (cacheHit) {
#ifdef HAVE_PROTOBUF
      if(luaconfsLocal->protobufServer && (!luaconfsLocal->protobufTaggedOnly || !pbMessage.getAppliedPolicy().empty() || !pbMessage.getPolicyTags().empty())) {
        Netmask requestorNM(fromaddr, fromaddr.sin4.sin_family == AF_INET ? luaconfsLocal->protobufMaskV4 : luaconfsLocal->protobufMaskV6);
        const ComboAddress& requestor = requestorNM.getMaskedNetwork();
        pbMessage.update(uniqueId, &requestor, &destaddr, false, dh->id);
        pbMessage.setEDNSSubnet(ednssubnet.source, ednssubnet.source.isIpv4() ? luaconfsLocal->protobufMaskV4 : luaconfsLocal->protobufMaskV6);
        pbMessage.setQueryTime(g_now.tv_sec, g_now.tv_usec);
        pbMessage.setRequestorId(requestorId);
        protobufLogResponse(luaconfsLocal->protobufServer, pbMessage);
      }
#endif /* HAVE_PROTOBUF */
      if(!g_quiet)
        L<<Logger::Notice<<t_id<< " question answered from packet cache tag="<<ctag<<" from "<<fromaddr.toString()<<endl;

      g_stats.packetCacheHits++;
      SyncRes::s_queries++;
      ageDNSPacket(response, age);
      struct msghdr msgh;
      struct iovec iov;
      char cbuf[256];
      fillMSGHdr(&msgh, &iov, cbuf, 0, (char*)response.c_str(), response.length(), const_cast<ComboAddress*>(&fromaddr));
      msgh.msg_control=NULL;

      if(g_fromtosockets.count(fd)) {
	addCMsgSrcAddr(&msgh, cbuf, &destaddr, 0);
      }
      if(sendmsg(fd, &msgh, 0) < 0 && g_logCommonErrors)
        L<<Logger::Warning<<"Sending UDP reply to client "<<fromaddr.toStringWithPort()<<" failed with: "<<strerror(errno)<<endl;

      if(response.length() >= sizeof(struct dnsheader)) {
        struct dnsheader tmpdh;
        memcpy(&tmpdh, response.c_str(), sizeof(tmpdh));
        updateResponseStats(tmpdh.rcode, fromaddr, response.length(), 0, 0);
      }
      g_stats.avgLatencyUsec=(1-1.0/g_latencyStatSize)*g_stats.avgLatencyUsec + 0.0; // we assume 0 usec
      return 0;
    }
  }
  catch(std::exception& e) {
    L<<Logger::Error<<"Error processing or aging answer packet: "<<e.what()<<endl;
    return 0;
  }

  if(t_pdl) {
    if(t_pdl->ipfilter(fromaddr, destaddr, *dh)) {
      if(!g_quiet)
	L<<Logger::Notice<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] DROPPED question from "<<fromaddr.toStringWithPort()<<" based on policy"<<endl;
      g_stats.policyDrops++;
      return 0;
    }
  }

  if(MT->numProcesses() > g_maxMThreads) {
    if(!g_quiet)
      L<<Logger::Notice<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] DROPPED question from "<<fromaddr.toStringWithPort()<<", over capacity"<<endl;

    g_stats.overCapacityDrops++;
    return 0;
  }

  DNSComboWriter* dc = new DNSComboWriter(question.c_str(), question.size(), g_now);
  dc->setSocket(fd);
  dc->d_tag=ctag;
  dc->d_qhash=qhash;
  dc->d_query = question;
  dc->setRemote(&fromaddr);
  dc->setLocal(destaddr);
  dc->d_tcp=false;
  dc->d_policyTags = policyTags;
  dc->d_data = data;
  dc->d_ecsFound = ecsFound;
  dc->d_ecsParsed = ecsParsed;
  dc->d_ednssubnet = ednssubnet;
#ifdef HAVE_PROTOBUF
  if (luaconfsLocal->protobufServer || luaconfsLocal->outgoingProtobufServer) {
    dc->d_uuid = uniqueId;
  }
  dc->d_requestorId = requestorId;
#endif

  MT->makeThread(startDoResolve, (void*) dc); // deletes dc
  return 0;
}


static void handleNewUDPQuestion(int fd, FDMultiplexer::funcparam_t& var)
{
  ssize_t len;
  char data[1500];
  ComboAddress fromaddr;
  struct msghdr msgh;
  struct iovec iov;
  char cbuf[256];
  bool firstQuery = true;

  fromaddr.sin6.sin6_family=AF_INET6; // this makes sure fromaddr is big enough
  fillMSGHdr(&msgh, &iov, cbuf, sizeof(cbuf), data, sizeof(data), &fromaddr);

  for(;;)
  if((len=recvmsg(fd, &msgh, 0)) >= 0) {

    firstQuery = false;

    if(t_remotes)
      t_remotes->push_back(fromaddr);

    if(t_allowFrom && !t_allowFrom->match(&fromaddr)) {
      if(!g_quiet)
        L<<Logger::Error<<"["<<MT->getTid()<<"] dropping UDP query from "<<fromaddr.toString()<<", address not matched by allow-from"<<endl;

      g_stats.unauthorizedUDP++;
      return;
    }
    BOOST_STATIC_ASSERT(offsetof(sockaddr_in, sin_port) == offsetof(sockaddr_in6, sin6_port));
    if(!fromaddr.sin4.sin_port) { // also works for IPv6
     if(!g_quiet)
        L<<Logger::Error<<"["<<MT->getTid()<<"] dropping UDP query from "<<fromaddr.toStringWithPort()<<", can't deal with port 0"<<endl;

      g_stats.clientParseError++; // not quite the best place to put it, but needs to go somewhere
      return;
    }
    try {
      dnsheader* dh=(dnsheader*)data;

      if(dh->qr) {
        g_stats.ignoredCount++;
        if(g_logCommonErrors)
          L<<Logger::Error<<"Ignoring answer from "<<fromaddr.toString()<<" on server socket!"<<endl;
      }
      else if(dh->opcode) {
        g_stats.ignoredCount++;
        if(g_logCommonErrors)
          L<<Logger::Error<<"Ignoring non-query opcode "<<dh->opcode<<" from "<<fromaddr.toString()<<" on server socket!"<<endl;
      }
      else {
        string question(data, (size_t)len);
	struct timeval tv={0,0};
	HarvestTimestamp(&msgh, &tv);
	ComboAddress dest;
	memset(&dest, 0, sizeof(dest)); // this makes sure we ignore this address if not returned by recvmsg above
        auto loc = rplookup(g_listenSocketsAddresses, fd);
	if(HarvestDestinationAddress(&msgh, &dest)) {
          // but.. need to get port too
          if(loc) 
            dest.sin4.sin_port = loc->sin4.sin_port;
        }
        else {
          if(loc) {
            dest = *loc;
          }
          else {
            dest.sin4.sin_family = fromaddr.sin4.sin_family;
            socklen_t slen = dest.getSocklen();
            getsockname(fd, (sockaddr*)&dest, &slen); // if this fails, we're ok with it
          }
        }
        if(g_weDistributeQueries)
          distributeAsyncFunction(question, boost::bind(doProcessUDPQuestion, question, fromaddr, dest, tv, fd));
        else
          doProcessUDPQuestion(question, fromaddr, dest, tv, fd);
      }
    }
    catch(MOADNSException& mde) {
      g_stats.clientParseError++;
      if(g_logCommonErrors)
        L<<Logger::Error<<"Unable to parse packet from remote UDP client "<<fromaddr.toString() <<": "<<mde.what()<<endl;
    }
    catch(std::runtime_error& e) {
      g_stats.clientParseError++;
      if(g_logCommonErrors)
        L<<Logger::Error<<"Unable to parse packet from remote UDP client "<<fromaddr.toString() <<": "<<e.what()<<endl;
    }
  }
  else {
    // cerr<<t_id<<" had error: "<<stringerror()<<endl;
    if(firstQuery && errno == EAGAIN)
      g_stats.noPacketError++;

    break;
  }
}

static void makeTCPServerSockets(unsigned int threadId)
{
  int fd;
  vector<string>locals;
  stringtok(locals,::arg()["local-address"]," ,");

  if(locals.empty())
    throw PDNSException("No local address specified");

  for(vector<string>::const_iterator i=locals.begin();i!=locals.end();++i) {
    ServiceTuple st;
    st.port=::arg().asNum("local-port");
    parseService(*i, st);

    ComboAddress sin;

    memset((char *)&sin,0, sizeof(sin));
    sin.sin4.sin_family = AF_INET;
    if(!IpToU32(st.host, (uint32_t*)&sin.sin4.sin_addr.s_addr)) {
      sin.sin6.sin6_family = AF_INET6;
      if(makeIPv6sockaddr(st.host, &sin.sin6) < 0)
        throw PDNSException("Unable to resolve local address for TCP server on '"+ st.host +"'");
    }

    fd=socket(sin.sin6.sin6_family, SOCK_STREAM, 0);
    if(fd<0)
      throw PDNSException("Making a TCP server socket for resolver: "+stringerror());

    setCloseOnExec(fd);

    int tmp=1;
    if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &tmp, sizeof tmp)<0) {
      L<<Logger::Error<<"Setsockopt failed for TCP listening socket"<<endl;
      exit(1);
    }
    if(sin.sin6.sin6_family == AF_INET6 && setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &tmp, sizeof(tmp)) < 0) {
      L<<Logger::Error<<"Failed to set IPv6 socket to IPv6 only, continuing anyhow: "<<strerror(errno)<<endl;
    }

#ifdef TCP_DEFER_ACCEPT
    if(setsockopt(fd, SOL_TCP, TCP_DEFER_ACCEPT, &tmp, sizeof tmp) >= 0) {
      if(i==locals.begin())
        L<<Logger::Error<<"Enabled TCP data-ready filter for (slight) DoS protection"<<endl;
    }
#endif

    if( ::arg().mustDo("non-local-bind") )
	Utility::setBindAny(AF_INET, fd);

#ifdef SO_REUSEPORT
    if(g_reusePort) {
      if(setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &tmp, sizeof(tmp)) < 0)
        throw PDNSException("SO_REUSEPORT: "+stringerror());
    }
#endif

    if (::arg().asNum("tcp-fast-open") > 0) {
#ifdef TCP_FASTOPEN
      int fastOpenQueueSize = ::arg().asNum("tcp-fast-open");
      if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &fastOpenQueueSize, sizeof fastOpenQueueSize) < 0) {
        L<<Logger::Error<<"Failed to enable TCP Fast Open for listening socket: "<<strerror(errno)<<endl;
      }
#else
      L<<Logger::Warning<<"TCP Fast Open configured but not supported for listening socket"<<endl;
#endif
    }

    sin.sin4.sin_port = htons(st.port);
    socklen_t socklen=sin.sin4.sin_family==AF_INET ? sizeof(sin.sin4) : sizeof(sin.sin6);
    if (::bind(fd, (struct sockaddr *)&sin, socklen )<0)
      throw PDNSException("Binding TCP server socket for "+ st.host +": "+stringerror());

    setNonBlocking(fd);
    setSocketSendBuffer(fd, 65000);
    listen(fd, 128);
    deferredAdds[threadId].push_back(make_pair(fd, handleNewTCPQuestion));
    g_tcpListenSockets.push_back(fd);
    // we don't need to update g_listenSocketsAddresses since it doesn't work for TCP/IP:
    //  - fd is not that which we know here, but returned from accept()
    if(sin.sin4.sin_family == AF_INET)
      L<<Logger::Error<<"Listening for TCP queries on "<< sin.toString() <<":"<<st.port<<endl;
    else
      L<<Logger::Error<<"Listening for TCP queries on ["<< sin.toString() <<"]:"<<st.port<<endl;
  }
}

static void makeUDPServerSockets(unsigned int threadId)
{
  int one=1;
  vector<string>locals;
  stringtok(locals,::arg()["local-address"]," ,");

  if(locals.empty())
    throw PDNSException("No local address specified");

  for(vector<string>::const_iterator i=locals.begin();i!=locals.end();++i) {
    ServiceTuple st;
    st.port=::arg().asNum("local-port");
    parseService(*i, st);

    ComboAddress sin;

    memset(&sin, 0, sizeof(sin));
    sin.sin4.sin_family = AF_INET;
    if(!IpToU32(st.host.c_str() , (uint32_t*)&sin.sin4.sin_addr.s_addr)) {
      sin.sin6.sin6_family = AF_INET6;
      if(makeIPv6sockaddr(st.host, &sin.sin6) < 0)
        throw PDNSException("Unable to resolve local address for UDP server on '"+ st.host +"'");
    }

    int fd=socket(sin.sin4.sin_family, SOCK_DGRAM, 0);
    if(fd < 0) {
      throw PDNSException("Making a UDP server socket for resolver: "+netstringerror());
    }
    if (!setSocketTimestamps(fd))
      L<<Logger::Warning<<"Unable to enable timestamp reporting for socket"<<endl;

    if(IsAnyAddress(sin)) {
      if(sin.sin4.sin_family == AF_INET)
        if(!setsockopt(fd, IPPROTO_IP, GEN_IP_PKTINFO, &one, sizeof(one)))     // linux supports this, so why not - might fail on other systems
          g_fromtosockets.insert(fd);
#ifdef IPV6_RECVPKTINFO
      if(sin.sin4.sin_family == AF_INET6)
        if(!setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)))
          g_fromtosockets.insert(fd);
#endif
      if(sin.sin6.sin6_family == AF_INET6 && setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)) < 0) {
	L<<Logger::Error<<"Failed to set IPv6 socket to IPv6 only, continuing anyhow: "<<strerror(errno)<<endl;
      }
    }
    if( ::arg().mustDo("non-local-bind") )
	Utility::setBindAny(AF_INET6, fd);

    setCloseOnExec(fd);

    setSocketReceiveBuffer(fd, 250000);
    sin.sin4.sin_port = htons(st.port);

  
#ifdef SO_REUSEPORT
    if(g_reusePort) {
      if(setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) < 0)
        throw PDNSException("SO_REUSEPORT: "+stringerror());
    }
#endif
  socklen_t socklen=sin.getSocklen();
    if (::bind(fd, (struct sockaddr *)&sin, socklen)<0)
      throw PDNSException("Resolver binding to server socket on port "+ std::to_string(st.port) +" for "+ st.host+": "+stringerror());

    setNonBlocking(fd);

    deferredAdds[threadId].push_back(make_pair(fd, handleNewUDPQuestion));
    g_listenSocketsAddresses[fd]=sin;  // this is written to only from the startup thread, not from the workers
    if(sin.sin4.sin_family == AF_INET)
      L<<Logger::Error<<"Listening for UDP queries on "<< sin.toString() <<":"<<st.port<<endl;
    else
      L<<Logger::Error<<"Listening for UDP queries on ["<< sin.toString() <<"]:"<<st.port<<endl;
  }
}

static void daemonize(void)
{
  if(fork())
    exit(0); // bye bye

  setsid();

  int i=open("/dev/null",O_RDWR); /* open stdin */
  if(i < 0)
    L<<Logger::Critical<<"Unable to open /dev/null: "<<stringerror()<<endl;
  else {
    dup2(i,0); /* stdin */
    dup2(i,1); /* stderr */
    dup2(i,2); /* stderr */
    close(i);
  }
}

static void usr1Handler(int)
{
  statsWanted=true;
}

static void usr2Handler(int)
{
  g_quiet= !g_quiet;
  SyncRes::setDefaultLogMode(g_quiet ? SyncRes::LogNone : SyncRes::Log);
  ::arg().set("quiet")=g_quiet ? "" : "no";
}

static void doStats(void)
{
  static time_t lastOutputTime;
  static uint64_t lastQueryCount;

  uint64_t cacheHits = broadcastAccFunction<uint64_t>(pleaseGetCacheHits);
  uint64_t cacheMisses = broadcastAccFunction<uint64_t>(pleaseGetCacheMisses);

  if(g_stats.qcounter && (cacheHits + cacheMisses) && SyncRes::s_queries && SyncRes::s_outqueries) {
    L<<Logger::Notice<<"stats: "<<g_stats.qcounter<<" questions, "<<
      broadcastAccFunction<uint64_t>(pleaseGetCacheSize)<< " cache entries, "<<
      broadcastAccFunction<uint64_t>(pleaseGetNegCacheSize)<<" negative entries, "<<
      (int)((cacheHits*100.0)/(cacheHits+cacheMisses))<<"% cache hits"<<endl;

    L<<Logger::Notice<<"stats: throttle map: "
      << broadcastAccFunction<uint64_t>(pleaseGetThrottleSize) <<", ns speeds: "
      << broadcastAccFunction<uint64_t>(pleaseGetNsSpeedsSize)<<endl;
    L<<Logger::Notice<<"stats: outpacket/query ratio "<<(int)(SyncRes::s_outqueries*100.0/SyncRes::s_queries)<<"%";
    L<<Logger::Notice<<", "<<(int)(SyncRes::s_throttledqueries*100.0/(SyncRes::s_outqueries+SyncRes::s_throttledqueries))<<"% throttled, "
     <<SyncRes::s_nodelegated<<" no-delegation drops"<<endl;
    L<<Logger::Notice<<"stats: "<<SyncRes::s_tcpoutqueries<<" outgoing tcp connections, "<<
      broadcastAccFunction<uint64_t>(pleaseGetConcurrentQueries)<<" queries running, "<<SyncRes::s_outgoingtimeouts<<" outgoing timeouts"<<endl;

    //L<<Logger::Notice<<"stats: "<<g_stats.ednsPingMatches<<" ping matches, "<<g_stats.ednsPingMismatches<<" mismatches, "<<
      //g_stats.noPingOutQueries<<" outqueries w/o ping, "<< g_stats.noEdnsOutQueries<<" w/o EDNS"<<endl;

    L<<Logger::Notice<<"stats: " <<  broadcastAccFunction<uint64_t>(pleaseGetPacketCacheSize) <<
    " packet cache entries, "<<(int)(100.0*broadcastAccFunction<uint64_t>(pleaseGetPacketCacheHits)/SyncRes::s_queries) << "% packet cache hits"<<endl;

    time_t now = time(0);
    if(lastOutputTime && lastQueryCount && now != lastOutputTime) {
      L<<Logger::Notice<<"stats: "<< (SyncRes::s_queries - lastQueryCount) / (now - lastOutputTime) <<" qps (average over "<< (now - lastOutputTime) << " seconds)"<<endl;
    }
    lastOutputTime = now;
    lastQueryCount = SyncRes::s_queries;
  }
  else if(statsWanted)
    L<<Logger::Notice<<"stats: no stats yet!"<<endl;

  statsWanted=false;
}

static void houseKeeping(void *)
{
  static thread_local time_t last_stat, last_rootupdate, last_prune, last_secpoll;
  static thread_local int cleanCounter=0;
  static thread_local bool s_running;  // houseKeeping can get suspended in secpoll, and be restarted, which makes us do duplicate work
  try {
    if(s_running)
      return;
    s_running=true;

    struct timeval now;
    Utility::gettimeofday(&now, 0);

    if(now.tv_sec - last_prune > (time_t)(5 + t_id)) {
      DTime dt;
      dt.setTimeval(now);
      t_RC->doPrune(); // this function is local to a thread, so fine anyhow
      t_packetCache->doPruneTo(::arg().asNum("max-packetcache-entries") / g_numWorkerThreads);

      SyncRes::pruneNegCache(::arg().asNum("max-cache-entries") / (g_numWorkerThreads * 10));

      if(!((cleanCounter++)%40)) {  // this is a full scan!
	time_t limit=now.tv_sec-300;
        SyncRes::pruneNSSpeeds(limit);
      }
      last_prune=time(0);
    }

    if(now.tv_sec - last_rootupdate > 7200) {
      int res = SyncRes::getRootNS(g_now, nullptr);
      if (!res)
        last_rootupdate=now.tv_sec;
    }

    if(!t_id) {
      if(g_statisticsInterval > 0 && now.tv_sec - last_stat >= g_statisticsInterval) {
	doStats();
	last_stat=time(0);
      }

      if(now.tv_sec - last_secpoll >= 3600) {
	try {
	  doSecPoll(&last_secpoll);
	}
	catch(...) {}
      }
    }
    s_running=false;
  }
  catch(PDNSException& ae)
    {
      s_running=false;
      L<<Logger::Error<<"Fatal error in housekeeping thread: "<<ae.reason<<endl;
      throw;
    }
}

static void makeThreadPipes()
{
  for(unsigned int n=0; n < g_numThreads; ++n) {
    struct ThreadPipeSet tps;
    int fd[2];
    if(pipe(fd) < 0)
      unixDie("Creating pipe for inter-thread communications");

    tps.readToThread = fd[0];
    tps.writeToThread = fd[1];

    if(pipe(fd) < 0)
      unixDie("Creating pipe for inter-thread communications");
    tps.readFromThread = fd[0];
    tps.writeFromThread = fd[1];

    g_pipes.push_back(tps);
  }
}

struct ThreadMSG
{
  pipefunc_t func;
  bool wantAnswer;
};

void broadcastFunction(const pipefunc_t& func, bool skipSelf)
{
  unsigned int n = 0;
  for(ThreadPipeSet& tps : g_pipes)
  {
    if(n++ == t_id) {
      if(!skipSelf)
        func(); // don't write to ourselves!
      continue;
    }

    ThreadMSG* tmsg = new ThreadMSG();
    tmsg->func = func;
    tmsg->wantAnswer = true;
    if(write(tps.writeToThread, &tmsg, sizeof(tmsg)) != sizeof(tmsg)) {
      delete tmsg;
      unixDie("write to thread pipe returned wrong size or error");
    }

    string* resp;
    if(read(tps.readFromThread, &resp, sizeof(resp)) != sizeof(resp))
      unixDie("read from thread pipe returned wrong size or error");

    if(resp) {
//      cerr <<"got response: " << *resp << endl;
      delete resp;
    }
  }
}

void distributeAsyncFunction(const string& packet, const pipefunc_t& func)
{
  unsigned int hash = hashQuestion(packet.c_str(), packet.length(), g_disthashseed);
  unsigned int target = 1 + (hash % (g_pipes.size()-1));

  if(target == t_id) {
    func();
    return;
  }
  ThreadPipeSet& tps = g_pipes[target];
  ThreadMSG* tmsg = new ThreadMSG();
  tmsg->func = func;
  tmsg->wantAnswer = false;

  if(write(tps.writeToThread, &tmsg, sizeof(tmsg)) != sizeof(tmsg)) {
    delete tmsg;
    unixDie("write to thread pipe returned wrong size or error");
  }
}

static void handlePipeRequest(int fd, FDMultiplexer::funcparam_t& var)
{
  ThreadMSG* tmsg = nullptr;

  if(read(fd, &tmsg, sizeof(tmsg)) != sizeof(tmsg)) { // fd == readToThread
    unixDie("read from thread pipe returned wrong size or error");
  }

  void *resp=0;
  try {
    resp = tmsg->func();
  }
  catch(std::exception& e) {
    if(g_logCommonErrors)
      L<<Logger::Error<<"PIPE function we executed created exception: "<<e.what()<<endl; // but what if they wanted an answer.. we send 0
  }
  catch(PDNSException& e) {
    if(g_logCommonErrors)
      L<<Logger::Error<<"PIPE function we executed created PDNS exception: "<<e.reason<<endl; // but what if they wanted an answer.. we send 0
  }
  if(tmsg->wantAnswer) {
    if(write(g_pipes[t_id].writeFromThread, &resp, sizeof(resp)) != sizeof(resp)) {
      delete tmsg;
      unixDie("write to thread pipe returned wrong size or error");
    }
  }

  delete tmsg;
}

template<class T> void *voider(const boost::function<T*()>& func)
{
  return func();
}

vector<ComboAddress>& operator+=(vector<ComboAddress>&a, const vector<ComboAddress>& b)
{
  a.insert(a.end(), b.begin(), b.end());
  return a;
}

vector<pair<string, uint16_t> >& operator+=(vector<pair<string, uint16_t> >&a, const vector<pair<string, uint16_t> >& b)
{
  a.insert(a.end(), b.begin(), b.end());
  return a;
}

vector<pair<DNSName, uint16_t> >& operator+=(vector<pair<DNSName, uint16_t> >&a, const vector<pair<DNSName, uint16_t> >& b)
{
  a.insert(a.end(), b.begin(), b.end());
  return a;
}


template<class T> T broadcastAccFunction(const boost::function<T*()>& func, bool skipSelf)
{
  unsigned int n = 0;
  T ret=T();
  for(ThreadPipeSet& tps : g_pipes)
  {
    if(n++ == t_id) {
      if(!skipSelf) {
        T* resp = (T*)func(); // don't write to ourselves!
        if(resp) {
          //~ cerr <<"got direct: " << *resp << endl;
          ret += *resp;
          delete resp;
        }
      }
      continue;
    }

    ThreadMSG* tmsg = new ThreadMSG();
    tmsg->func = boost::bind(voider<T>, func);
    tmsg->wantAnswer = true;

    if(write(tps.writeToThread, &tmsg, sizeof(tmsg)) != sizeof(tmsg)) {
      delete tmsg;
      unixDie("write to thread pipe returned wrong size or error");
    }

    T* resp;
    if(read(tps.readFromThread, &resp, sizeof(resp)) != sizeof(resp))
      unixDie("read from thread pipe returned wrong size or error");

    if(resp) {
      //~ cerr <<"got response: " << *resp << endl;
      ret += *resp;
      delete resp;
    }
  }
  return ret;
}

template string broadcastAccFunction(const boost::function<string*()>& fun, bool skipSelf); // explicit instantiation
template uint64_t broadcastAccFunction(const boost::function<uint64_t*()>& fun, bool skipSelf); // explicit instantiation
template vector<ComboAddress> broadcastAccFunction(const boost::function<vector<ComboAddress> *()>& fun, bool skipSelf); // explicit instantiation
template vector<pair<DNSName,uint16_t> > broadcastAccFunction(const boost::function<vector<pair<DNSName, uint16_t> > *()>& fun, bool skipSelf); // explicit instantiation

static void handleRCC(int fd, FDMultiplexer::funcparam_t& var)
{
  string remote;
  string msg=s_rcc.recv(&remote);
  RecursorControlParser rcp;
  RecursorControlParser::func_t* command;

  string answer=rcp.getAnswer(msg, &command);

  // If we are inside a chroot, we need to strip
  if (!arg()["chroot"].empty()) {
    size_t len = arg()["chroot"].length();
    remote = remote.substr(len);
  }

  try {
    s_rcc.send(answer, &remote);
    command();
  }
  catch(std::exception& e) {
    L<<Logger::Error<<"Error dealing with control socket request: "<<e.what()<<endl;
  }
  catch(PDNSException& ae) {
    L<<Logger::Error<<"Error dealing with control socket request: "<<ae.reason<<endl;
  }
}

static void handleTCPClientReadable(int fd, FDMultiplexer::funcparam_t& var)
{
  PacketID* pident=any_cast<PacketID>(&var);
  //  cerr<<"handleTCPClientReadable called for fd "<<fd<<", pident->inNeeded: "<<pident->inNeeded<<", "<<pident->sock->getHandle()<<endl;

  shared_array<char> buffer(new char[pident->inNeeded]);

  ssize_t ret=recv(fd, buffer.get(), pident->inNeeded,0);
  if(ret > 0) {
    pident->inMSG.append(&buffer[0], &buffer[ret]);
    pident->inNeeded-=(size_t)ret;
    if(!pident->inNeeded || pident->inIncompleteOkay) {
      //      cerr<<"Got entire load of "<<pident->inMSG.size()<<" bytes"<<endl;
      PacketID pid=*pident;
      string msg=pident->inMSG;

      t_fdm->removeReadFD(fd);
      MT->sendEvent(pid, &msg);
    }
    else {
      //      cerr<<"Still have "<<pident->inNeeded<<" left to go"<<endl;
    }
  }
  else {
    PacketID tmp=*pident;
    t_fdm->removeReadFD(fd); // pident might now be invalid (it isn't, but still)
    string empty;
    MT->sendEvent(tmp, &empty); // this conveys error status
  }
}

static void handleTCPClientWritable(int fd, FDMultiplexer::funcparam_t& var)
{
  PacketID* pid=any_cast<PacketID>(&var);
  ssize_t ret=send(fd, pid->outMSG.c_str() + pid->outPos, pid->outMSG.size() - pid->outPos,0);
  if(ret > 0) {
    pid->outPos+=(ssize_t)ret;
    if(pid->outPos==pid->outMSG.size()) {
      PacketID tmp=*pid;
      t_fdm->removeWriteFD(fd);
      MT->sendEvent(tmp, &tmp.outMSG);  // send back what we sent to convey everything is ok
    }
  }
  else {  // error or EOF
    PacketID tmp(*pid);
    t_fdm->removeWriteFD(fd);
    string sent;
    MT->sendEvent(tmp, &sent);         // we convey error status by sending empty string
  }
}

// resend event to everybody chained onto it
static void doResends(MT_t::waiters_t::iterator& iter, PacketID resend, const string& content)
{
  if(iter->key.chain.empty())
    return;
  //  cerr<<"doResends called!\n";
  for(PacketID::chain_t::iterator i=iter->key.chain.begin(); i != iter->key.chain.end() ; ++i) {
    resend.fd=-1;
    resend.id=*i;
    //    cerr<<"\tResending "<<content.size()<<" bytes for fd="<<resend.fd<<" and id="<<resend.id<<endl;

    MT->sendEvent(resend, &content);
    g_stats.chainResends++;
  }
}

static void handleUDPServerResponse(int fd, FDMultiplexer::funcparam_t& var)
{
  PacketID pid=any_cast<PacketID>(var);
  ssize_t len;
  char data[g_outgoingEDNSBufsize];
  ComboAddress fromaddr;
  socklen_t addrlen=sizeof(fromaddr);

  len=recvfrom(fd, data, sizeof(data), 0, (sockaddr *)&fromaddr, &addrlen);

  if(len < (ssize_t) sizeof(dnsheader)) {
    if(len < 0)
      ; //      cerr<<"Error on fd "<<fd<<": "<<stringerror()<<"\n";
    else {
      g_stats.serverParseError++;
      if(g_logCommonErrors)
        L<<Logger::Error<<"Unable to parse packet from remote UDP server "<< fromaddr.toString() <<
          ": packet smaller than DNS header"<<endl;
    }

    t_udpclientsocks->returnSocket(fd);
    string empty;

    MT_t::waiters_t::iterator iter=MT->d_waiters.find(pid);
    if(iter != MT->d_waiters.end())
      doResends(iter, pid, empty);

    MT->sendEvent(pid, &empty); // this denotes error (does lookup again.. at least L1 will be hot)
    return;
  }

  dnsheader dh;
  memcpy(&dh, data, sizeof(dh));

  PacketID pident;
  pident.remote=fromaddr;
  pident.id=dh.id;
  pident.fd=fd;

  if(!dh.qr && g_logCommonErrors) {
    L<<Logger::Notice<<"Not taking data from question on outgoing socket from "<< fromaddr.toStringWithPort()  <<endl;
  }

  if(!dh.qdcount || // UPC, Nominum, very old BIND on FormErr, NSD
     !dh.qr) {      // one weird server
    pident.domain.clear();
    pident.type = 0;
  }
  else {
    try {
      if(len > 12)
        pident.domain=DNSName(data, len, 12, false, &pident.type); // don't copy this from above - we need to do the actual read
    }
    catch(std::exception& e) {
      g_stats.serverParseError++; // won't be fed to lwres.cc, so we have to increment
      L<<Logger::Warning<<"Error in packet from remote nameserver "<< fromaddr.toStringWithPort() << ": "<<e.what() << endl;
      return;
    }
  }
  string packet;
  packet.assign(data, len);

  MT_t::waiters_t::iterator iter=MT->d_waiters.find(pident);
  if(iter != MT->d_waiters.end()) {
    doResends(iter, pident, packet);
  }

retryWithName:

  if(!MT->sendEvent(pident, &packet)) {
    // we do a full scan for outstanding queries on unexpected answers. not too bad since we only accept them on the right port number, which is hard enough to guess
    for(MT_t::waiters_t::iterator mthread=MT->d_waiters.begin(); mthread!=MT->d_waiters.end(); ++mthread) {
      if(pident.fd==mthread->key.fd && mthread->key.remote==pident.remote &&  mthread->key.type == pident.type &&
         pident.domain == mthread->key.domain) {
        mthread->key.nearMisses++;
      }

      // be a bit paranoid here since we're weakening our matching
      if(pident.domain.empty() && !mthread->key.domain.empty() && !pident.type && mthread->key.type &&
         pident.id  == mthread->key.id && mthread->key.remote == pident.remote) {
        // cerr<<"Empty response, rest matches though, sending to a waiter"<<endl;
        pident.domain = mthread->key.domain;
        pident.type = mthread->key.type;
        goto retryWithName; // note that this only passes on an error, lwres will still reject the packet
      }
    }
    g_stats.unexpectedCount++; // if we made it here, it really is an unexpected answer
    if(g_logCommonErrors) {
      L<<Logger::Warning<<"Discarding unexpected packet from "<<fromaddr.toStringWithPort()<<": "<< (pident.domain.empty() ? "<empty>" : pident.domain.toString())<<", "<<pident.type<<", "<<MT->d_waiters.size()<<" waiters"<<endl;
    }
  }
  else if(fd >= 0) {
    t_udpclientsocks->returnSocket(fd);
  }
}

FDMultiplexer* getMultiplexer()
{
  FDMultiplexer* ret;
  for(const auto& i : FDMultiplexer::getMultiplexerMap()) {
    try {
      ret=i.second();
      return ret;
    }
    catch(FDMultiplexerException &fe) {
      L<<Logger::Error<<"Non-fatal error initializing possible multiplexer ("<<fe.what()<<"), falling back"<<endl;
    }
    catch(...) {
      L<<Logger::Error<<"Non-fatal error initializing possible multiplexer"<<endl;
    }
  }
  L<<Logger::Error<<"No working multiplexer found!"<<endl;
  exit(1);
}


static string* doReloadLuaScript()
{
  string fname= ::arg()["lua-dns-script"];
  try {
    if(fname.empty()) {
      t_pdl.reset();
      L<<Logger::Error<<t_id<<" Unloaded current lua script"<<endl;
      return new string("unloaded\n");
    }
    else {
      t_pdl = std::make_shared<RecursorLua4>(fname);
    }
  }
  catch(std::exception& e) {
    L<<Logger::Error<<t_id<<" Retaining current script, error from '"<<fname<<"': "<< e.what() <<endl;
    return new string("retaining current script, error from '"+fname+"': "+e.what()+"\n");
  }

  L<<Logger::Warning<<t_id<<" (Re)loaded lua script from '"<<fname<<"'"<<endl;
  return new string("(re)loaded '"+fname+"'\n");
}

string doQueueReloadLuaScript(vector<string>::const_iterator begin, vector<string>::const_iterator end)
{
  if(begin != end)
    ::arg().set("lua-dns-script") = *begin;

  return broadcastAccFunction<string>(doReloadLuaScript);
}

static string* pleaseUseNewTraceRegex(const std::string& newRegex)
try
{
  if(newRegex.empty()) {
    t_traceRegex.reset();
    return new string("unset\n");
  }
  else {
    t_traceRegex = std::make_shared<Regex>(newRegex);
    return new string("ok\n");
  }
}
catch(PDNSException& ae)
{
  return new string(ae.reason+"\n");
}

string doTraceRegex(vector<string>::const_iterator begin, vector<string>::const_iterator end)
{
  return broadcastAccFunction<string>(boost::bind(pleaseUseNewTraceRegex, begin!=end ? *begin : ""));
}

static void checkLinuxIPv6Limits()
{
#ifdef __linux__
  string line;
  if(readFileIfThere("/proc/sys/net/ipv6/route/max_size", &line)) {
    int lim=std::stoi(line);
    if(lim < 16384) {
      L<<Logger::Error<<"If using IPv6, please raise sysctl net.ipv6.route.max_size, currently set to "<<lim<<" which is < 16384"<<endl;
    }
  }
#endif
}
static void checkOrFixFDS()
{
  unsigned int availFDs=getFilenumLimit(); 
  unsigned int wantFDs = g_maxMThreads * g_numWorkerThreads +25; // even healthier margin then before

  if(wantFDs > availFDs) {
    unsigned int hardlimit= getFilenumLimit(true);
    if(hardlimit >= wantFDs) {
      setFilenumLimit(wantFDs);
      L<<Logger::Warning<<"Raised soft limit on number of filedescriptors to "<<wantFDs<<" to match max-mthreads and threads settings"<<endl;
    }
    else {
      int newval = (hardlimit - 25) / g_numWorkerThreads;
      L<<Logger::Warning<<"Insufficient number of filedescriptors available for max-mthreads*threads setting! ("<<hardlimit<<" < "<<wantFDs<<"), reducing max-mthreads to "<<newval<<endl;
      g_maxMThreads = newval;
      setFilenumLimit(hardlimit);
    }
  }
}

static void* recursorThread(void*);

static void* pleaseSupplantACLs(std::shared_ptr<NetmaskGroup> ng)
{
  t_allowFrom = ng;
  return nullptr;
}

int g_argc;
char** g_argv;

void parseACLs()
{
  static bool l_initialized;

  if(l_initialized) { // only reload configuration file on second call
    string configname=::arg()["config-dir"]+"/recursor.conf";
    cleanSlashes(configname);

    if(!::arg().preParseFile(configname.c_str(), "allow-from-file"))
      throw runtime_error("Unable to re-parse configuration file '"+configname+"'");
    ::arg().preParseFile(configname.c_str(), "allow-from", LOCAL_NETS);
    ::arg().preParseFile(configname.c_str(), "include-dir");
    ::arg().preParse(g_argc, g_argv, "include-dir");

    // then process includes
    std::vector<std::string> extraConfigs;
    ::arg().gatherIncludes(extraConfigs);

    for(const std::string& fn : extraConfigs) {
      if(!::arg().preParseFile(fn.c_str(), "allow-from-file", ::arg()["allow-from-file"]))
	throw runtime_error("Unable to re-parse configuration file include '"+fn+"'");
      if(!::arg().preParseFile(fn.c_str(), "allow-from", ::arg()["allow-from"]))
	throw runtime_error("Unable to re-parse configuration file include '"+fn+"'");
    }

    ::arg().preParse(g_argc, g_argv, "allow-from-file");
    ::arg().preParse(g_argc, g_argv, "allow-from");
  }

  std::shared_ptr<NetmaskGroup> oldAllowFrom = t_allowFrom;
  std::shared_ptr<NetmaskGroup> allowFrom = std::make_shared<NetmaskGroup>();

  if(!::arg()["allow-from-file"].empty()) {
    string line;
    ifstream ifs(::arg()["allow-from-file"].c_str());
    if(!ifs) {
      throw runtime_error("Could not open '"+::arg()["allow-from-file"]+"': "+stringerror());
    }

    string::size_type pos;
    while(getline(ifs,line)) {
      pos=line.find('#');
      if(pos!=string::npos)
        line.resize(pos);
      trim(line);
      if(line.empty())
        continue;

      allowFrom->addMask(line);
    }
    L<<Logger::Warning<<"Done parsing " << allowFrom->size() <<" allow-from ranges from file '"<<::arg()["allow-from-file"]<<"' - overriding 'allow-from' setting"<<endl;
  }
  else if(!::arg()["allow-from"].empty()) {
    vector<string> ips;
    stringtok(ips, ::arg()["allow-from"], ", ");

    L<<Logger::Warning<<"Only allowing queries from: ";
    for(vector<string>::const_iterator i = ips.begin(); i!= ips.end(); ++i) {
      allowFrom->addMask(*i);
      if(i!=ips.begin())
        L<<Logger::Warning<<", ";
      L<<Logger::Warning<<*i;
    }
    L<<Logger::Warning<<endl;
  }
  else {
    if(::arg()["local-address"]!="127.0.0.1" && ::arg().asNum("local-port")==53)
      L<<Logger::Error<<"WARNING: Allowing queries from all IP addresses - this can be a security risk!"<<endl;
    allowFrom = nullptr;
  }

  g_initialAllowFrom = allowFrom;
  broadcastFunction(boost::bind(pleaseSupplantACLs, allowFrom));
  oldAllowFrom = nullptr;

  l_initialized = true;
}


static void setupDelegationOnly()
{
  vector<string> parts;
  stringtok(parts, ::arg()["delegation-only"], ", \t");
  for(const auto& p : parts) {
    SyncRes::addDelegationOnly(DNSName(p));
  }
}

static std::map<unsigned int, std::set<int> > parseCPUMap()
{
  std::map<unsigned int, std::set<int> > result;

  const std::string value = ::arg()["cpu-map"];

  if (!value.empty() && !isSettingThreadCPUAffinitySupported()) {
    L<<Logger::Warning<<"CPU mapping requested but not supported, skipping"<<endl;
    return result;
  }

  std::vector<std::string> parts;

  stringtok(parts, value, " \t");

  for(const auto& part : parts) {
    if (part.find('=') == string::npos)
      continue;

    try {
      auto headers = splitField(part, '=');
      trim(headers.first);
      trim(headers.second);

      unsigned int threadId = pdns_stou(headers.first);
      std::vector<std::string> cpus;

      stringtok(cpus, headers.second, ",");

      for(const auto& cpu : cpus) {
        int cpuId = std::stoi(cpu);

        result[threadId].insert(cpuId);
      }
    }
    catch(const std::exception& e) {
      L<<Logger::Error<<"Error parsing cpu-map entry '"<<part<<"': "<<e.what()<<endl;
    }
  }

  return result;
}

static void setCPUMap(const std::map<unsigned int, std::set<int> >& cpusMap, unsigned int n, pthread_t tid)
{
  const auto& cpuMapping = cpusMap.find(n);
  if (cpuMapping != cpusMap.cend()) {
    int rc = mapThreadToCPUList(tid, cpuMapping->second);
    if (rc == 0) {
      L<<Logger::Info<<"CPU affinity for worker "<<n<<" has been set to CPU map:";
      for (const auto cpu : cpuMapping->second) {
        L<<Logger::Info<<" "<<cpu;
      }
      L<<Logger::Info<<endl;
    }
    else {
      L<<Logger::Warning<<"Error setting CPU affinity for worker "<<n<<" to CPU map:";
      for (const auto cpu : cpuMapping->second) {
        L<<Logger::Info<<" "<<cpu;
      }
      L<<Logger::Info<<strerror(rc)<<endl;
    }
  }
}

static int serviceMain(int argc, char*argv[])
{
  L.setName(s_programname);
  L.disableSyslog(::arg().mustDo("disable-syslog"));

  if(!::arg()["logging-facility"].empty()) {
    int val=logFacilityToLOG(::arg().asNum("logging-facility") );
    if(val >= 0)
      theL().setFacility(val);
    else
      L<<Logger::Error<<"Unknown logging facility "<<::arg().asNum("logging-facility") <<endl;
  }

  showProductVersion();
  seedRandom(::arg()["entropy-source"]);

  g_disthashseed=dns_random(0xffffffff);

  checkLinuxIPv6Limits();
  try {
    vector<string> addrs;
    if(!::arg()["query-local-address6"].empty()) {
      SyncRes::s_doIPv6=true;
      L<<Logger::Warning<<"Enabling IPv6 transport for outgoing queries"<<endl;

      stringtok(addrs, ::arg()["query-local-address6"], ", ;");
      for(const string& addr : addrs) {
        g_localQueryAddresses6.push_back(ComboAddress(addr));
      }
    }
    else {
      L<<Logger::Warning<<"NOT using IPv6 for outgoing queries - set 'query-local-address6=::' to enable"<<endl;
    }
    addrs.clear();
    stringtok(addrs, ::arg()["query-local-address"], ", ;");
    for(const string& addr : addrs) {
      g_localQueryAddresses4.push_back(ComboAddress(addr));
    }
  }
  catch(std::exception& e) {
    L<<Logger::Error<<"Assigning local query addresses: "<<e.what();
    exit(99);
  }

  // keep this ABOVE loadRecursorLuaConfig!
  if(::arg()["dnssec"]=="off")
    g_dnssecmode=DNSSECMode::Off;
  else if(::arg()["dnssec"]=="process-no-validate")
    g_dnssecmode=DNSSECMode::ProcessNoValidate;
  else if(::arg()["dnssec"]=="process")
    g_dnssecmode=DNSSECMode::Process;
  else if(::arg()["dnssec"]=="validate")
    g_dnssecmode=DNSSECMode::ValidateAll;
  else if(::arg()["dnssec"]=="log-fail")
    g_dnssecmode=DNSSECMode::ValidateForLog;
  else {
    L<<Logger::Error<<"Unknown DNSSEC mode "<<::arg()["dnssec"]<<endl;
    exit(1);
  }

  g_dnssecLogBogus = ::arg().mustDo("dnssec-log-bogus");
  g_maxNSEC3Iterations = ::arg().asNum("nsec3-max-iterations");

  try {
    loadRecursorLuaConfig(::arg()["lua-config-file"], ::arg().mustDo("daemon"));
  }
  catch (PDNSException &e) {
    L<<Logger::Error<<"Cannot load Lua configuration: "<<e.reason<<endl;
    exit(1);
  }

  parseACLs();
  sortPublicSuffixList();

  if(!::arg()["dont-query"].empty()) {
    vector<string> ips;
    stringtok(ips, ::arg()["dont-query"], ", ");
    ips.push_back("0.0.0.0");
    ips.push_back("::");

    L<<Logger::Warning<<"Will not send queries to: ";
    for(vector<string>::const_iterator i = ips.begin(); i!= ips.end(); ++i) {
      SyncRes::addDontQuery(*i);
      if(i!=ips.begin())
        L<<Logger::Warning<<", ";
      L<<Logger::Warning<<*i;
    }
    L<<Logger::Warning<<endl;
  }

  g_quiet=::arg().mustDo("quiet");

  g_weDistributeQueries = ::arg().mustDo("pdns-distributes-queries");
  if(g_weDistributeQueries) {
      L<<Logger::Warning<<"PowerDNS Recursor itself will distribute queries over threads"<<endl;
  }

  setupDelegationOnly();
  g_outgoingEDNSBufsize=::arg().asNum("edns-outgoing-bufsize");

  if(::arg()["trace"]=="fail") {
    SyncRes::setDefaultLogMode(SyncRes::Store);
  }
  else if(::arg().mustDo("trace")) {
    SyncRes::setDefaultLogMode(SyncRes::Log);
    ::arg().set("quiet")="no";
    g_quiet=false;
    g_dnssecLOG=true;
  }

  SyncRes::s_minimumTTL = ::arg().asNum("minimum-ttl-override");

  SyncRes::s_nopacketcache = ::arg().mustDo("disable-packetcache");

  SyncRes::s_maxnegttl=::arg().asNum("max-negative-ttl");
  SyncRes::s_maxcachettl=max(::arg().asNum("max-cache-ttl"), 15);
  SyncRes::s_packetcachettl=::arg().asNum("packetcache-ttl");
  // Cap the packetcache-servfail-ttl to the packetcache-ttl
  uint32_t packetCacheServFailTTL = ::arg().asNum("packetcache-servfail-ttl");
  SyncRes::s_packetcacheservfailttl=(packetCacheServFailTTL > SyncRes::s_packetcachettl) ? SyncRes::s_packetcachettl : packetCacheServFailTTL;
  SyncRes::s_serverdownmaxfails=::arg().asNum("server-down-max-fails");
  SyncRes::s_serverdownthrottletime=::arg().asNum("server-down-throttle-time");
  SyncRes::s_serverID=::arg()["server-id"];
  SyncRes::s_maxqperq=::arg().asNum("max-qperq");
  SyncRes::s_maxtotusec=1000*::arg().asNum("max-total-msec");
  SyncRes::s_maxdepth=::arg().asNum("max-recursion-depth");
  SyncRes::s_rootNXTrust = ::arg().mustDo( "root-nx-trust");
  if(SyncRes::s_serverID.empty()) {
    char tmp[128];
    gethostname(tmp, sizeof(tmp)-1);
    SyncRes::s_serverID=tmp;
  }

  SyncRes::s_ecsipv4limit = ::arg().asNum("ecs-ipv4-bits");
  SyncRes::s_ecsipv6limit = ::arg().asNum("ecs-ipv6-bits");

  g_networkTimeoutMsec = ::arg().asNum("network-timeout");

  g_initialDomainMap = parseAuthAndForwards();

  g_latencyStatSize=::arg().asNum("latency-statistic-size");

  g_logCommonErrors=::arg().mustDo("log-common-errors");

  g_anyToTcp = ::arg().mustDo("any-to-tcp");
  g_udpTruncationThreshold = ::arg().asNum("udp-truncation-threshold");

  g_lowercaseOutgoing = ::arg().mustDo("lowercase-outgoing");

  g_numWorkerThreads = ::arg().asNum("threads");
  g_numThreads = g_numWorkerThreads + g_weDistributeQueries;
  g_maxMThreads = ::arg().asNum("max-mthreads");

  g_gettagNeedsEDNSOptions = ::arg().mustDo("gettag-needs-edns-options");

  g_statisticsInterval = ::arg().asNum("statistics-interval");

#ifdef SO_REUSEPORT
  g_reusePort = ::arg().mustDo("reuseport");
#endif

  g_useOneSocketPerThread = (!g_weDistributeQueries && g_reusePort);

  if (g_useOneSocketPerThread) {
    for (unsigned int threadId = 0; threadId < g_numWorkerThreads; threadId++) {
      makeUDPServerSockets(threadId);
      makeTCPServerSockets(threadId);
    }
  }
  else {
    makeUDPServerSockets(0);
    makeTCPServerSockets(0);
  }

  SyncRes::parseEDNSSubnetWhitelist(::arg()["edns-subnet-whitelist"]);
  g_useIncomingECS = ::arg().mustDo("use-incoming-edns-subnet");

  int forks;
  for(forks = 0; forks < ::arg().asNum("processes") - 1; ++forks) {
    if(!fork()) // we are child
      break;
  }

  if(::arg().mustDo("daemon")) {
    L<<Logger::Warning<<"Calling daemonize, going to background"<<endl;
    L.toConsole(Logger::Critical);
    daemonize();
    loadRecursorLuaConfig(::arg()["lua-config-file"], false);
  }
  signal(SIGUSR1,usr1Handler);
  signal(SIGUSR2,usr2Handler);
  signal(SIGPIPE,SIG_IGN);

  checkOrFixFDS();

#ifdef HAVE_LIBSODIUM
  if (sodium_init() == -1) {
    L<<Logger::Error<<"Unable to initialize sodium crypto library"<<endl;
    exit(99);
  }
#endif

  openssl_thread_setup();
  openssl_seed();

  int newgid=0;
  if(!::arg()["setgid"].empty())
    newgid=Utility::makeGidNumeric(::arg()["setgid"]);
  int newuid=0;
  if(!::arg()["setuid"].empty())
    newuid=Utility::makeUidNumeric(::arg()["setuid"]);

  Utility::dropGroupPrivs(newuid, newgid);

  if (!::arg()["chroot"].empty()) {
#ifdef HAVE_SYSTEMD
     char *ns;
     ns = getenv("NOTIFY_SOCKET");
     if (ns != nullptr) {
       L<<Logger::Error<<"Unable to chroot when running from systemd. Please disable chroot= or set the 'Type' for this service to 'simple'"<<endl;
       exit(1);
     }
#endif
    if (chroot(::arg()["chroot"].c_str())<0 || chdir("/") < 0) {
      L<<Logger::Error<<"Unable to chroot to '"+::arg()["chroot"]+"': "<<strerror (errno)<<", exiting"<<endl;
      exit(1);
    }
    else
      L<<Logger::Error<<"Chrooted to '"<<::arg()["chroot"]<<"'"<<endl;
  }

  s_pidfname=::arg()["socket-dir"]+"/"+s_programname+".pid";
  if(!s_pidfname.empty())
    unlink(s_pidfname.c_str()); // remove possible old pid file
  writePid();

  makeControlChannelSocket( ::arg().asNum("processes") > 1 ? forks : -1);

  Utility::dropUserPrivs(newuid);

  makeThreadPipes();

  g_tcpTimeout=::arg().asNum("client-tcp-timeout");
  g_maxTCPPerClient=::arg().asNum("max-tcp-per-client");
  g_tcpMaxQueriesPerConn=::arg().asNum("max-tcp-queries-per-connection");

  if (::arg().mustDo("snmp-agent")) {
    g_snmpAgent = std::make_shared<RecursorSNMPAgent>("recursor", ::arg()["snmp-master-socket"]);
    g_snmpAgent->run();
  }

  const auto cpusMap = parseCPUMap();
  if(g_numThreads == 1) {
    L<<Logger::Warning<<"Operating unthreaded"<<endl;
#ifdef HAVE_SYSTEMD
    sd_notify(0, "READY=1");
#endif
    setCPUMap(cpusMap, 0, pthread_self());
    recursorThread(0);
  }
  else {
    pthread_t tid;
    L<<Logger::Warning<<"Launching "<< g_numThreads <<" threads"<<endl;
    for(unsigned int n=0; n < g_numThreads; ++n) {
      pthread_create(&tid, 0, recursorThread, (void*)(long)n);

      setCPUMap(cpusMap, n, tid);
    }
    void* res;
#ifdef HAVE_SYSTEMD
    sd_notify(0, "READY=1");
#endif
    pthread_join(tid, &res);
  }
  return 0;
}

static void* recursorThread(void* ptr)
try
{
  t_id=(int) (long) ptr;
  SyncRes tmp(g_now); // make sure it allocates tsstorage before we do anything, like primeHints or so..
  SyncRes::setDomainMap(g_initialDomainMap);
  t_allowFrom = g_initialAllowFrom;
  t_udpclientsocks = std::unique_ptr<UDPClientSocks>(new UDPClientSocks());
  t_tcpClientCounts = std::unique_ptr<tcpClientCounts_t>(new tcpClientCounts_t());
  primeHints();

  t_packetCache = std::unique_ptr<RecursorPacketCache>(new RecursorPacketCache());

#ifdef HAVE_PROTOBUF
  t_uuidGenerator = std::unique_ptr<boost::uuids::random_generator>(new boost::uuids::random_generator());
#endif
  L<<Logger::Warning<<"Done priming cache with root hints"<<endl;

  try {
    if(!::arg()["lua-dns-script"].empty()) {
      t_pdl = std::make_shared<RecursorLua4>(::arg()["lua-dns-script"]);
      L<<Logger::Warning<<"Loaded 'lua' script from '"<<::arg()["lua-dns-script"]<<"'"<<endl;
    }
  }
  catch(std::exception &e) {
    L<<Logger::Error<<"Failed to load 'lua' script from '"<<::arg()["lua-dns-script"]<<"': "<<e.what()<<endl;
    _exit(99);
  }

  unsigned int ringsize=::arg().asNum("stats-ringbuffer-entries") / g_numWorkerThreads;
  if(ringsize) {
    t_remotes = std::unique_ptr<addrringbuf_t>(new addrringbuf_t());
    if(g_weDistributeQueries)  // if so, only 1 thread does recvfrom
      t_remotes->set_capacity(::arg().asNum("stats-ringbuffer-entries"));
    else
      t_remotes->set_capacity(ringsize);
    t_servfailremotes = std::unique_ptr<addrringbuf_t>(new addrringbuf_t());
    t_servfailremotes->set_capacity(ringsize);
    t_largeanswerremotes = std::unique_ptr<addrringbuf_t>(new addrringbuf_t());
    t_largeanswerremotes->set_capacity(ringsize);

    t_queryring = std::unique_ptr<boost::circular_buffer<pair<DNSName, uint16_t> > >(new boost::circular_buffer<pair<DNSName, uint16_t> >());
    t_queryring->set_capacity(ringsize);
    t_servfailqueryring = std::unique_ptr<boost::circular_buffer<pair<DNSName, uint16_t> > >(new boost::circular_buffer<pair<DNSName, uint16_t> >());
    t_servfailqueryring->set_capacity(ringsize);
  }

  MT=std::unique_ptr<MTasker<PacketID,string> >(new MTasker<PacketID,string>(::arg().asNum("stack-size")));

  PacketID pident;

  t_fdm=getMultiplexer();
  if(!t_id) {
    if(::arg().mustDo("webserver")) {
      L<<Logger::Warning << "Enabling web server" << endl;
      try {
        new RecursorWebServer(t_fdm);
      }
      catch(PDNSException &e) {
        L<<Logger::Error<<"Exception: "<<e.reason<<endl;
        exit(99);
      }
    }
    L<<Logger::Error<<"Enabled '"<< t_fdm->getName() << "' multiplexer"<<endl;
  }

  t_fdm->addReadFD(g_pipes[t_id].readToThread, handlePipeRequest);

  if(g_useOneSocketPerThread) {
    for(deferredAdd_t::const_iterator i = deferredAdds[t_id].cbegin(); i != deferredAdds[t_id].cend(); ++i) {
      t_fdm->addReadFD(i->first, i->second);
    }
  }
  else {
    if(!g_weDistributeQueries || !t_id) { // if we distribute queries, only t_id = 0 listens
      for(deferredAdd_t::const_iterator i = deferredAdds[0].cbegin(); i != deferredAdds[0].cend(); ++i) {
        t_fdm->addReadFD(i->first, i->second);
      }
    }
  }

  registerAllStats();
  if(!t_id) {
    t_fdm->addReadFD(s_rcc.d_fd, handleRCC); // control channel
  }

  unsigned int maxTcpClients=::arg().asNum("max-tcp-clients");

  bool listenOnTCP(true);

  time_t last_carbon=0;
  time_t carbonInterval=::arg().asNum("carbon-interval");
  counter.store(0); // used to periodically execute certain tasks
  for(;;) {
    while(MT->schedule(&g_now)); // MTasker letting the mthreads do their thing

    if(!(counter%500)) {
      MT->makeThread(houseKeeping, 0);
    }

    if(!(counter%55)) {
      typedef vector<pair<int, FDMultiplexer::funcparam_t> > expired_t;
      expired_t expired=t_fdm->getTimeouts(g_now);

      for(expired_t::iterator i=expired.begin() ; i != expired.end(); ++i) {
        shared_ptr<TCPConnection> conn=any_cast<shared_ptr<TCPConnection> >(i->second);
        if(g_logCommonErrors)
          L<<Logger::Warning<<"Timeout from remote TCP client "<< conn->d_remote.toString() <<endl;
        t_fdm->removeReadFD(i->first);
      }
    }

    counter++;

    if(!t_id && statsWanted) {
      doStats();
    }

    Utility::gettimeofday(&g_now, 0);

    if(!t_id && (g_now.tv_sec - last_carbon >= carbonInterval)) {
      MT->makeThread(doCarbonDump, 0);
      last_carbon = g_now.tv_sec;
    }

    t_fdm->run(&g_now);
    // 'run' updates g_now for us

    if(!g_weDistributeQueries || !t_id) { // if pdns distributes queries, only tid 0 should do this
      if(listenOnTCP) {
	if(TCPConnection::getCurrentConnections() > maxTcpClients) {  // shutdown, too many connections
	  for(tcpListenSockets_t::iterator i=g_tcpListenSockets.begin(); i != g_tcpListenSockets.end(); ++i)
	    t_fdm->removeReadFD(*i);
	  listenOnTCP=false;
	}
      }
      else {
	if(TCPConnection::getCurrentConnections() <= maxTcpClients) {  // reenable
	  for(tcpListenSockets_t::iterator i=g_tcpListenSockets.begin(); i != g_tcpListenSockets.end(); ++i)
	    t_fdm->addReadFD(*i, handleNewTCPQuestion);
	  listenOnTCP=true;
	}
      }
    }
  }
}
catch(PDNSException &ae) {
  L<<Logger::Error<<"Exception: "<<ae.reason<<endl;
  return 0;
}
catch(std::exception &e) {
   L<<Logger::Error<<"STL Exception: "<<e.what()<<endl;
   return 0;
}
catch(...) {
   L<<Logger::Error<<"any other exception in main: "<<endl;
   return 0;
}


int main(int argc, char **argv)
{
  g_argc = argc;
  g_argv = argv;
  g_stats.startupTime=time(0);
  versionSetProduct(ProductRecursor);
  reportBasicTypes();
  reportOtherTypes();

  int ret = EXIT_SUCCESS;

  try {
    ::arg().set("stack-size","stack size per mthread")="200000";
    ::arg().set("soa-minimum-ttl","Don't change")="0";
    ::arg().set("no-shuffle","Don't change")="off";
    ::arg().set("local-port","port to listen on")="53";
    ::arg().set("local-address","IP addresses to listen on, separated by spaces or commas. Also accepts ports.")="127.0.0.1";
    ::arg().setSwitch("non-local-bind", "Enable binding to non-local addresses by using FREEBIND / BINDANY socket options")="no";
    ::arg().set("trace","if we should output heaps of logging. set to 'fail' to only log failing domains")="off";
    ::arg().set("dnssec", "DNSSEC mode: off/process-no-validate (default)/process/log-fail/validate")="process-no-validate";
    ::arg().set("dnssec-log-bogus", "Log DNSSEC bogus validations")="no";
    ::arg().set("daemon","Operate as a daemon")="no";
    ::arg().setSwitch("write-pid","Write a PID file")="yes";
    ::arg().set("loglevel","Amount of logging. Higher is more. Do not set below 3")="6";
    ::arg().set("disable-syslog","Disable logging to syslog, useful when running inside a supervisor that logs stdout")="no";
    ::arg().set("log-common-errors","If we should log rather common errors")="no";
    ::arg().set("chroot","switch to chroot jail")="";
    ::arg().set("setgid","If set, change group id to this gid for more security")="";
    ::arg().set("setuid","If set, change user id to this uid for more security")="";
    ::arg().set("network-timeout", "Wait this number of milliseconds for network i/o")="1500";
    ::arg().set("threads", "Launch this number of threads")="2";
    ::arg().set("processes", "Launch this number of processes (EXPERIMENTAL, DO NOT CHANGE)")="1"; // if we un-experimental this, need to fix openssl rand seeding for multiple PIDs!
    ::arg().set("config-name","Name of this virtual configuration - will rename the binary image")="";
    ::arg().set("api-config-dir", "Directory where REST API stores config and zones") = "";
    ::arg().set("api-key", "Static pre-shared authentication key for access to the REST API") = "";
    ::arg().set("api-logfile", "Location of the server logfile (used by the REST API)") = "/var/log/pdns.log";
    ::arg().set("api-readonly", "Disallow data modification through the REST API when set") = "no";
    ::arg().setSwitch("webserver", "Start a webserver (for REST API)") = "no";
    ::arg().set("webserver-address", "IP Address of webserver to listen on") = "127.0.0.1";
    ::arg().set("webserver-port", "Port of webserver to listen on") = "8082";
    ::arg().set("webserver-password", "Password required for accessing the webserver") = "";
    ::arg().set("webserver-allow-from","Webserver access is only allowed from these subnets")="0.0.0.0/0,::/0";
    ::arg().set("carbon-ourname", "If set, overrides our reported hostname for carbon stats")="";
    ::arg().set("carbon-server", "If set, send metrics in carbon (graphite) format to this server IP address")="";
    ::arg().set("carbon-interval", "Number of seconds between carbon (graphite) updates")="30";
    ::arg().set("statistics-interval", "Number of seconds between printing of recursor statistics, 0 to disable")="1800";
    ::arg().set("quiet","Suppress logging of questions and answers")="";
    ::arg().set("logging-facility","Facility to log messages as. 0 corresponds to local0")="";
    ::arg().set("config-dir","Location of configuration directory (recursor.conf)")=SYSCONFDIR;
    ::arg().set("socket-owner","Owner of socket")="";
    ::arg().set("socket-group","Group of socket")="";
    ::arg().set("socket-mode", "Permissions for socket")="";

    ::arg().set("socket-dir",string("Where the controlsocket will live, ")+LOCALSTATEDIR+" when unset and not chrooted" )="";
    ::arg().set("delegation-only","Which domains we only accept delegations from")="";
    ::arg().set("query-local-address","Source IP address for sending queries")="0.0.0.0";
    ::arg().set("query-local-address6","Source IPv6 address for sending queries. IF UNSET, IPv6 WILL NOT BE USED FOR OUTGOING QUERIES")="";
    ::arg().set("client-tcp-timeout","Timeout in seconds when talking to TCP clients")="2";
    ::arg().set("max-mthreads", "Maximum number of simultaneous Mtasker threads")="2048";
    ::arg().set("max-tcp-clients","Maximum number of simultaneous TCP clients")="128";
    ::arg().set("server-down-max-fails","Maximum number of consecutive timeouts (and unreachables) to mark a server as down ( 0 => disabled )")="64";
    ::arg().set("server-down-throttle-time","Number of seconds to throttle all queries to a server after being marked as down")="60";
    ::arg().set("hint-file", "If set, load root hints from this file")="";
    ::arg().set("max-cache-entries", "If set, maximum number of entries in the main cache")="1000000";
    ::arg().set("max-negative-ttl", "maximum number of seconds to keep a negative cached entry in memory")="3600";
    ::arg().set("max-cache-ttl", "maximum number of seconds to keep a cached entry in memory")="86400";
    ::arg().set("packetcache-ttl", "maximum number of seconds to keep a cached entry in packetcache")="3600";
    ::arg().set("max-packetcache-entries", "maximum number of entries to keep in the packetcache")="500000";
    ::arg().set("packetcache-servfail-ttl", "maximum number of seconds to keep a cached servfail entry in packetcache")="60";
    ::arg().set("server-id", "Returned when queried for 'server.id' TXT or NSID, defaults to hostname")="";
    ::arg().set("stats-ringbuffer-entries", "maximum number of packets to store statistics for")="10000";
    ::arg().set("version-string", "string reported on version.pdns or version.bind")=fullVersionString();
    ::arg().set("allow-from", "If set, only allow these comma separated netmasks to recurse")=LOCAL_NETS;
    ::arg().set("allow-from-file", "If set, load allowed netmasks from this file")="";
    ::arg().set("entropy-source", "If set, read entropy from this file")="/dev/urandom";
    ::arg().set("dont-query", "If set, do not query these netmasks for DNS data")=DONT_QUERY;
    ::arg().set("max-tcp-per-client", "If set, maximum number of TCP sessions per client (IP address)")="0";
    ::arg().set("max-tcp-queries-per-connection", "If set, maximum number of TCP queries in a TCP connection")="0";
    ::arg().set("spoof-nearmiss-max", "If non-zero, assume spoofing after this many near misses")="20";
    ::arg().set("single-socket", "If set, only use a single socket for outgoing queries")="off";
    ::arg().set("auth-zones", "Zones for which we have authoritative data, comma separated domain=file pairs ")="";
    ::arg().set("lua-config-file", "More powerful configuration options")="";

    ::arg().set("forward-zones", "Zones for which we forward queries, comma separated domain=ip pairs")="";
    ::arg().set("forward-zones-recurse", "Zones for which we forward queries with recursion bit, comma separated domain=ip pairs")="";
    ::arg().set("forward-zones-file", "File with (+)domain=ip pairs for forwarding")="";
    ::arg().set("export-etc-hosts", "If we should serve up contents from /etc/hosts")="off";
    ::arg().set("export-etc-hosts-search-suffix", "Also serve up the contents of /etc/hosts with this suffix")="";
    ::arg().set("etc-hosts-file", "Path to 'hosts' file")="/etc/hosts";
    ::arg().set("serve-rfc1918", "If we should be authoritative for RFC 1918 private IP space")="yes";
    ::arg().set("lua-dns-script", "Filename containing an optional 'lua' script that will be used to modify dns answers")="";
    ::arg().set("latency-statistic-size","Number of latency values to calculate the qa-latency average")="10000";
    ::arg().setSwitch( "disable-packetcache", "Disable packetcache" )= "no";
    ::arg().set("ecs-ipv4-bits", "Number of bits of IPv4 address to pass for EDNS Client Subnet")="24";
    ::arg().set("ecs-ipv6-bits", "Number of bits of IPv6 address to pass for EDNS Client Subnet")="56";
    ::arg().set("edns-subnet-whitelist", "List of netmasks and domains that we should enable EDNS subnet for")="";
    ::arg().setSwitch( "use-incoming-edns-subnet", "Pass along received EDNS Client Subnet information")="no";
    ::arg().setSwitch( "pdns-distributes-queries", "If PowerDNS itself should distribute queries over threads")="yes";
    ::arg().setSwitch( "root-nx-trust", "If set, believe that an NXDOMAIN from the root means the TLD does not exist")="yes";
    ::arg().setSwitch( "any-to-tcp","Answer ANY queries with tc=1, shunting to TCP" )="no";
    ::arg().setSwitch( "lowercase-outgoing","Force outgoing questions to lowercase")="no";
    ::arg().setSwitch("gettag-needs-edns-options", "If EDNS Options should be extracted before calling the gettag() hook")="no";
    ::arg().set("udp-truncation-threshold", "Maximum UDP response size before we truncate")="1680";
    ::arg().set("edns-outgoing-bufsize", "Outgoing EDNS buffer size")="1680";
    ::arg().set("minimum-ttl-override", "Set under adverse conditions, a minimum TTL")="0";
    ::arg().set("max-qperq", "Maximum outgoing queries per query")="50";
    ::arg().set("max-total-msec", "Maximum total wall-clock time per query in milliseconds, 0 for unlimited")="7000";
    ::arg().set("max-recursion-depth", "Maximum number of internal recursion calls per query, 0 for unlimited")="40";

    ::arg().set("include-dir","Include *.conf files from this directory")="";
    ::arg().set("security-poll-suffix","Domain name from which to query security update notifications")="secpoll.powerdns.com.";
    
    ::arg().setSwitch("reuseport","Enable SO_REUSEPORT allowing multiple recursors processes to listen to 1 address")="no";

    ::arg().setSwitch("snmp-agent", "If set, register as an SNMP agent")="no";
    ::arg().set("snmp-master-socket", "If set and snmp-agent is set, the socket to use to register to the SNMP master")="";

    ::arg().set("tcp-fast-open", "Enable TCP Fast Open support on the listening sockets, using the supplied numerical value as the queue size")="0";
    ::arg().set("nsec3-max-iterations", "Maximum number of iterations allowed for an NSEC3 record")="2500";

    ::arg().set("cpu-map", "Thread to CPU mapping, space separated thread-id=cpu1,cpu2..cpuN pairs")="";

    ::arg().setCmd("help","Provide a helpful message");
    ::arg().setCmd("version","Print version string");
    ::arg().setCmd("config","Output blank configuration");
    L.toConsole(Logger::Info);
    ::arg().laxParse(argc,argv); // do a lax parse

    string configname=::arg()["config-dir"]+"/recursor.conf";
    if(::arg()["config-name"]!="") {
      configname=::arg()["config-dir"]+"/recursor-"+::arg()["config-name"]+".conf";
      s_programname+="-"+::arg()["config-name"];
    }
    cleanSlashes(configname);

    if(::arg().mustDo("config")) {
      cout<<::arg().configstring()<<endl;
      exit(0);
    }

    if(!::arg().file(configname.c_str()))
      L<<Logger::Warning<<"Unable to parse configuration file '"<<configname<<"'"<<endl;

    ::arg().parse(argc,argv);

    if( !::arg()["chroot"].empty() && !::arg()["api-config-dir"].empty() && !::arg().mustDo("api-readonly") )  {
      L<<Logger::Error<<"Using chroot and a writable API is not possible"<<endl;
      exit(EXIT_FAILURE);
    }

    if (::arg()["socket-dir"].empty()) {
      if (::arg()["chroot"].empty())
        ::arg().set("socket-dir") = LOCALSTATEDIR;
      else
        ::arg().set("socket-dir") = "/";
    }

    ::arg().set("delegation-only")=toLower(::arg()["delegation-only"]);

    if(::arg().asNum("threads")==1)
      ::arg().set("pdns-distributes-queries")="no";

    if(::arg().mustDo("help")) {
      cout<<"syntax:"<<endl<<endl;
      cout<<::arg().helpstring(::arg()["help"])<<endl;
      exit(0);
    }
    if(::arg().mustDo("version")) {
      showProductVersion();
      showBuildConfiguration();
      exit(0);
    }

    Logger::Urgency logUrgency = (Logger::Urgency)::arg().asNum("loglevel");

    if (logUrgency < Logger::Error)
      logUrgency = Logger::Error;
    if(!g_quiet && logUrgency < Logger::Info) { // Logger::Info=6, Logger::Debug=7
      logUrgency = Logger::Info;                // if you do --quiet=no, you need Info to also see the query log
    }
    L.setLoglevel(logUrgency);
    L.toConsole(logUrgency);

    serviceMain(argc, argv);
  }
  catch(PDNSException &ae) {
    L<<Logger::Error<<"Exception: "<<ae.reason<<endl;
    ret=EXIT_FAILURE;
  }
  catch(std::exception &e) {
    L<<Logger::Error<<"STL Exception: "<<e.what()<<endl;
    ret=EXIT_FAILURE;
  }
  catch(...) {
    L<<Logger::Error<<"any other exception in main: "<<endl;
    ret=EXIT_FAILURE;
  }

  return ret;
}