[thirdparty/pdns.git] / pdns / pdns_recursor.cc

/*
    PowerDNS Versatile Database Driven Nameserver
    Copyright (C) 2003 - 2016  PowerDNS.COM BV

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2
    as published by the Free Software Foundation

    Additionally, the license of this program contains a special
    exception which allows to distribute the program in binary form when
    it is linked against OpenSSL.

    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 St, 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"
#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"

#ifndef RECURSOR
#include "statbag.hh"
StatBag S;
#endif

__thread FDMultiplexer* t_fdm;
__thread unsigned int t_id;
unsigned int g_maxTCPPerClient;
unsigned int g_networkTimeoutMsec;
uint64_t g_latencyStatSize;
bool g_logCommonErrors;
bool g_anyToTcp;
uint16_t g_udpTruncationThreshold, g_outgoingEDNSBufsize;
__thread shared_ptr<RecursorLua4>* t_pdl;

__thread addrringbuf_t* t_remotes, *t_servfailremotes, *t_largeanswerremotes;

__thread boost::circular_buffer<pair<DNSName, uint16_t> >* t_queryring, *t_servfailqueryring;
__thread shared_ptr<Regex>* t_traceRegex;

NetmaskGroup g_ednssubnets;
SuffixMatchNode g_ednsdomains;

RecursorControlChannel s_rcc; // only active in thread 0

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

vector<ThreadPipeSet> g_pipes; // effectively readonly after startup

SyncRes::domainmap_t* g_initialDomainMap; // new threads needs this to be setup

#include "namespaces.hh"

__thread MemRecursorCache* t_RC;
__thread RecursorPacketCache* t_packetCache;
RecursorStats g_stats;
bool g_quiet;

bool g_weDistributeQueries; // if true, only 1 thread listens on the incoming query sockets

__thread NetmaskGroup* t_allowFrom;
static NetmaskGroup* g_initialAllowFrom; // new thread needs to be setup with this

NetmaskGroup* g_dontQuery;
string s_programname="pdns_recursor";

typedef vector<int> tcpListenSockets_t;
tcpListenSockets_t g_tcpListenSockets;   // shared across threads, but this is fine, never written to from a thread. All threads listen on all sockets
int g_tcpTimeout;
unsigned int g_maxMThreads;
__thread struct timeval g_now; // timestamp, updated (too) frequently
typedef map<int, ComboAddress> listenSocketsAddresses_t; // is shared across all threads right now
listenSocketsAddresses_t g_listenSocketsAddresses; // is shared across all threads right now
set<int> g_fromtosockets; // listen sockets that use 'sendfromto()' mechanism

__thread MT_t* MT; // the big MTasker

unsigned int g_numThreads, g_numWorkerThreads;

#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(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;
  bool d_tcp;
  int d_socket;
  shared_ptr<TCPConnection> d_tcpConnection;
};


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


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;
}

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

// -1 is error, 0 is timeout, 1 is success
int arecvtcp(string& data, int 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;
}

void handleGenUDPQueryResponse(int fd, FDMultiplexer::funcparam_t& var)
{
  PacketID pident=*any_cast<PacketID>(&var);
  char resp[512];
  int ret=recv(fd, resp, sizeof(resp), 0);
  t_fdm->removeReadFD(fd);
  if(ret >= 0) {
    string data(resp, 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;
}


vector<ComboAddress> g_localQueryAddresses4, g_localQueryAddresses6;
const ComboAddress g_local4("0.0.0.0"), g_local6("::");

//! 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;
}

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

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);
      closesocket(*fd);
      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
    }
    closesocket(*i);

    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=(int)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);

    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 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, int 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, int len, int flags, const ComboAddress& fromaddr, int *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=(int)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;
}


string s_pidfname;
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;
}

typedef map<ComboAddress, uint32_t, ComboAddress::addressOnlyLessThan> tcpClientCounts_t;
tcpClientCounts_t __thread* t_tcpClientCounts;

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

TCPConnection::~TCPConnection()
{
  if(closesocket(d_fd) < 0)
    unixDie("closing socket for TCPConnection");
  if(t_tcpClientCounts->count(d_remote) && !(*t_tcpClientCounts)[d_remote]--)
    t_tcpClientCounts->erase(d_remote);
  --s_currentConnections;
}

AtomicCounter TCPConnection::s_currentConnections;
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.
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) // 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.toString()+"/"+DNSRecordContent::NumberToType(dc->d_mdp.d_qtype)+" from "+(dc->d_remote.toString())+")";
}
catch(...)
{
  return "Exception making error message for exception";
}

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

    uint32_t maxanswersize= dc->d_tcp ? 65535 : min((uint16_t) 512, g_udpTruncationThreshold);
    EDNSOpts edo;
    bool haveEDNS=false;
    if(getEDNSOpts(dc->d_mdp, &edo)) {
      if(!dc->d_tcp)
	maxanswersize = min(edo.d_packetsize, g_udpTruncationThreshold);
      haveEDNS=true;
    }
    vector<DNSRecord> ret;
    vector<uint8_t> packet;

    auto luaconfsLocal = g_luaconfs.getLocal();

    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;

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

    SyncRes sr(dc->d_now);
    if(t_pdl) {
      sr.setLuaEngine(*t_pdl);
      sr.d_requestor=dc->d_remote;
    }
    
    if(pw.getHeader()->cd || edo.d_Z & EDNSOpts::DNSSECOK)
      sr.d_doDNSSEC=true;

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

    int res;
    DNSFilterEngine::Policy dfepol;
    DNSRecord spoofed;
    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->get() && (*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()<<endl;

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


    // if there is a RecursorLua active, and it 'took' the query in preResolve, we don't launch beginResolve

    dfepol = luaconfsLocal->dfe.getQueryPolicy(dc->d_mdp.d_qname, dc->d_remote);

    switch(dfepol.d_kind) {
    case DNSFilterEngine::PolicyKind::NoAction:
      break;
    case DNSFilterEngine::PolicyKind::Drop:
      g_stats.policyDrops++;
      delete dc;
      dc=0;
      return; 
    case DNSFilterEngine::PolicyKind::NXDOMAIN:
      res=RCode::NXDomain;
      goto haveAnswer;

    case DNSFilterEngine::PolicyKind::NODATA:
      res=RCode::NoError;
      goto haveAnswer;

    case DNSFilterEngine::PolicyKind::Custom:
      res=RCode::NoError;
      spoofed.d_name=dc->d_mdp.d_qname;
      spoofed.d_type=dfepol.d_custom->getType();
      spoofed.d_ttl = dfepol.d_ttl;
      spoofed.d_class = 1;
      spoofed.d_content = dfepol.d_custom;
      spoofed.d_place = DNSResourceRecord::ANSWER;
      ret.push_back(spoofed);
      goto haveAnswer;


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


    if(!t_pdl->get() || !(*t_pdl)->preresolve(dc->d_remote, dc->d_local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer)) {
      try {
        res = sr.beginResolve(dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), dc->d_mdp.d_qclass, ret);
      }
      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;
      }

      dfepol = luaconfsLocal->dfe.getPostPolicy(ret); 
      switch(dfepol.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.d_name=dc->d_mdp.d_qname;
	spoofed.d_type=dfepol.d_custom->getType();
	spoofed.d_ttl = dfepol.d_ttl;
	spoofed.d_class = 1;
	spoofed.d_content = dfepol.d_custom;
	spoofed.d_place = DNSResourceRecord::ANSWER;
	ret.push_back(spoofed);
	goto haveAnswer;
      }

      if(t_pdl->get()) {
        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(dc->d_remote, dc->d_local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer);
	}
	else if(res == RCode::NXDomain)
	  (*t_pdl)->nxdomain(dc->d_remote, dc->d_local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer);
	

	(*t_pdl)->postresolve(dc->d_remote, dc->d_local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer);
	
      }
    }
  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;

      if(haveEDNS) {
	if(g_dnssecmode != DNSSECMode::Off && ((edo.d_Z & EDNSOpts::DNSSECOK) || g_dnssecmode == DNSSECMode::ValidateAll || g_dnssecmode==DNSSECMode::ValidateForLog)) {
	  auto state=validateRecords(ret);
	  if(state == Secure) {
	    pw.getHeader()->ad=1;
	  }
	  else if(state == Insecure) {
	    pw.getHeader()->ad=0;
	  }
	  else if(state == Bogus && !pw.getHeader()->cd) {
            if(g_dnssecmode == DNSSECMode::ValidateAll || (edo.d_Z & EDNSOpts::DNSSECOK)) {
              pw.getHeader()->rcode=RCode::ServFail;
              goto sendit;
            }
            else {
              L<<Logger::Warning<<"Failed to validate "<<dc->d_mdp.d_qname<<" for "<<dc->d_remote.toStringWithPort()<<endl;
            }
	  }
	}
      }


      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));
      }
      
      for(auto i=ret.cbegin(); i!=ret.cend(); ++i) {
	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() > 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
	}
      }
      if(ret.size())
	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);
    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);
      if(g_fromtosockets.count(dc->d_socket)) {
	addCMsgSrcAddr(&msgh, cbuf, &dc->d_local, 0);
      } else
        msgh.msg_control=NULL;
      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(string((const char*)&*packet.begin(), packet.size()),
                                            (edo.d_Z & EDNSOpts::DNSSECOK), // ponder filtering on dnssecmode here
                                            g_now.tv_sec,
                                            min(minTTL,
                                                (pw.getHeader()->rcode == RCode::ServFail) ? SyncRes::s_packetcacheservfailttl : SyncRes::s_packetcachettl
                                            )
        );
      }
      //      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 ret=Utility::writev(dc->d_socket, iov, 2);
      bool hadError=true;

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

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");
    chmod(sockname.c_str(), sockmode);
  }
}

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 > UINT16_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=0;
      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);

      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
void handleNewTCPQuestion(int fd, FDMultiplexer::funcparam_t& )
{
  ComboAddress addr;
  socklen_t addrlen=sizeof(addr);
  int newsock=(int)accept(fd, (struct sockaddr*)&addr, &addrlen);
  if(newsock>=0) {
    if(MT->numProcesses() > g_maxMThreads) {
      g_stats.overCapacityDrops++;
      closesocket(newsock);
      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++;
      closesocket(newsock);
      return;
    }
    if(g_maxTCPPerClient && t_tcpClientCounts->count(addr) && (*t_tcpClientCounts)[addr] >= g_maxTCPPerClient) {
      g_stats.tcpClientOverflow++;
      closesocket(newsock); // don't call TCPConnection::closeAndCleanup here - did not enter it in the counts yet!
      return;
    }

    setNonBlocking(newsock);
    shared_ptr<TCPConnection> tc(new 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);
  }
}

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();
  try {
    uint32_t age;
#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
    bool needsDNSSEC=false;

    if(dh->arcount) {
      unsigned int consumed=0;
      DNSName qname(question.c_str(), question.length(), sizeof(dnsheader), false, 0, 0, &consumed);
      if(question.size() > (consumed+12+11) && ((question[consumed+12+11]&0x80)==0x80))
        needsDNSSEC=true;
    }
    
    if(!SyncRes::s_nopacketcache && t_packetCache->getResponsePacket(question, needsDNSSEC, g_now.tv_sec, &response, &age)) {
      if(!g_quiet)
        L<<Logger::Notice<<t_id<< " question answered from packet cache from "<<fromaddr.toString()<<endl;
      // t_queryring->push_back("packetcached");

      
      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));
      if(g_fromtosockets.count(fd)) {
	addCMsgSrcAddr(&msgh, cbuf, &destaddr, 0);
      }
      else {
        msgh.msg_control=NULL;
      }
      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 dh;
        memcpy(&dh, response.c_str(), sizeof(dh));
        updateResponseStats(dh.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->get()) {
    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->setRemote(&fromaddr);
  dc->setLocal(destaddr);
  dc->d_tcp=false;
  MT->makeThread(startDoResolve, (void*) dc); // deletes dc
  return 0;
}


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

  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) {
    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, len);
	struct timeval tv={0,0};
	HarvestTimestamp(&msgh, &tv);
	ComboAddress dest;
	memset(&dest, 0, sizeof(dest)); // this makes sure we igore 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 len = dest.getSocklen();
            getsockname(fd, (sockaddr*)&dest, &len); // 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(errno == EAGAIN)
      g_stats.noPacketError++;
    break;
  }
}


typedef vector<pair<int, function< void(int, any&) > > > deferredAdd_t;
deferredAdd_t deferredAdd;

void makeTCPServerSockets()
{
  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,(char*)&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,(char*)&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);

    sin.sin4.sin_port = htons(st.port);
    int 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);
    deferredAdd.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;
  }
}

void makeUDPServerSockets()
{
  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);

    int 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);

    deferredAdd.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;
  }
}


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);
  }
}

AtomicCounter counter;
bool statsWanted;

void usr1Handler(int)
{
  statsWanted=true;
}

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

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

    //L<<Logger::Warning<<"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::Warning<<"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::Warning<<"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::Warning<<"stats: no stats yet!"<<endl;

  statsWanted=false;
}

static void houseKeeping(void *)
{
  static __thread time_t last_stat, last_rootupdate, last_prune, last_secpoll;
  static __thread int cleanCounter=0;
  static __thread 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);

      pruneCollection(t_sstorage->negcache, ::arg().asNum("max-cache-entries") / (g_numWorkerThreads * 10), 200);

      if(!((cleanCounter++)%40)) {  // this is a full scan!
	time_t limit=now.tv_sec-300;
	for(SyncRes::nsspeeds_t::iterator i = t_sstorage->nsSpeeds.begin() ; i!= t_sstorage->nsSpeeds.end(); )
	  if(i->second.stale(limit))
	    t_sstorage->nsSpeeds.erase(i++);
	  else
	    ++i;
      }
      last_prune=time(0);
    }

    if(now.tv_sec - last_rootupdate > 7200) {
      SyncRes sr(now);
      sr.setDoEDNS0(true);
      vector<DNSRecord> ret;

      sr.setNoCache();
      int res=-1;
      try {
	res=sr.beginResolve(DNSName("."), QType(QType::NS), 1, ret);
      }
      catch(PDNSException& e)
	{
	  L<<Logger::Error<<"Failed to update . records, got an exception: "<<e.reason<<endl;
	}

      catch(std::exception& e)
	{
	  L<<Logger::Error<<"Failed to update . records, got an exception: "<<e.what()<<endl;
	}

      catch(...)
	{
	  L<<Logger::Error<<"Failed to update . records, got an exception"<<endl;
	}
      if(!res) {
	L<<Logger::Notice<<"Refreshed . records"<<endl;
	last_rootupdate=now.tv_sec;
      }
      else
	L<<Logger::Error<<"Failed to update . records, RCODE="<<res<<endl;
    }

    if(!t_id) {
      if(now.tv_sec - last_stat >= 1800) {
	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;
    }
}

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;
    }
  }
}

static uint32_t g_disthashseed;
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");
  }
}

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

  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) {
    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) {
    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))
      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

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()) {
    int 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;
  }
}

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]);

  int ret=recv(fd, buffer.get(), pident->inNeeded,0);
  if(ret > 0) {
    pident->inMSG.append(&buffer[0], &buffer[ret]);
    pident->inNeeded-=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
  }
}

void handleTCPClientWritable(int fd, FDMultiplexer::funcparam_t& var)
{
  PacketID* pid=any_cast<PacketID>(&var);
  int ret=send(fd, pid->outMSG.c_str() + pid->outPos, pid->outMSG.size() - pid->outPos,0);
  if(ret > 0) {
    pid->outPos+=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
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++;
  }
}

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

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

  if(len < (int)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 {
      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 "<< 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<<", "<<pident.type<<", "<<MT->d_waiters.size()<<" waiters"<<endl;
    }
  }
  else if(fd >= 0) {
    t_udpclientsocks->returnSocket(fd);
  }
}

FDMultiplexer* getMultiplexer()
{
  FDMultiplexer* ret;
  for(FDMultiplexer::FDMultiplexermap_t::const_iterator i = FDMultiplexer::getMultiplexerMap().begin();
      i != FDMultiplexer::getMultiplexerMap().end(); ++i) {
    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);
}


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 = shared_ptr<RecursorLua4>(new 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);
}

string* pleaseUseNewTraceRegex(const std::string& newRegex)
try
{
  if(newRegex.empty()) {
    t_traceRegex->reset();
    return new string("unset\n");
  }
  else {
    (*t_traceRegex) = shared_ptr<Regex>(new 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);
    }
  }
}

void* recursorThread(void*);

void* pleaseSupplantACLs(NetmaskGroup *ng)
{
  t_allowFrom = ng;
  return 0;
}

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");
  }

  NetmaskGroup* oldAllowFrom = t_allowFrom, *allowFrom=new NetmaskGroup;

  if(!::arg()["allow-from-file"].empty()) {
    string line;
    ifstream ifs(::arg()["allow-from-file"].c_str());
    if(!ifs) {
      delete allowFrom;
      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;
    delete allowFrom;
    allowFrom = 0;
  }

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

  l_initialized = true;
}

boost::optional<Netmask> getEDNSSubnetMask(const ComboAddress& local, const DNSName&dn, const ComboAddress& rem)
{
  if(local.sin4.sin_family != AF_INET || local.sin4.sin_addr.s_addr) { // detect unset 'requestor'
    if(g_ednsdomains.check(dn) || g_ednssubnets.match(rem)) {
      int bits =local.sin4.sin_family == AF_INET ? 24 : 64;
      ComboAddress trunc(local);
      trunc.truncate(bits);
      return boost::optional<Netmask>(Netmask(trunc, bits));
    }
  }
  return boost::optional<Netmask>();
}

void  parseEDNSSubnetWhitelist(const std::string& wlist)
{
  vector<string> parts;
  stringtok(parts, wlist, ",; ");
  for(const auto& a : parts) {
    try {
      Netmask nm(a);
      g_ednssubnets.addMask(nm);
    }
    catch(...) {
      g_ednsdomains.add(DNSName(a));
    }
  }
}

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

int serviceMain(int argc, char*argv[])
{
  L.setName(s_programname);
  L.setLoglevel((Logger::Urgency)(6)); // info and up

  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);

  loadRecursorLuaConfig(::arg()["lua-config-file"]);

  parseACLs();
  sortPublicSuffixList();

  if(!::arg()["dont-query"].empty()) {
    g_dontQuery=new NetmaskGroup;
    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) {
      g_dontQuery->addMask(*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()["dnssec"]=="off") 
    g_dnssecmode=DNSSECMode::Off;
  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);
  }

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

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

  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);
  }

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

  SyncRes::s_maxnegttl=::arg().asNum("max-negative-ttl");
  SyncRes::s_maxcachettl=::arg().asNum("max-cache-ttl");
  SyncRes::s_packetcachettl=::arg().asNum("packetcache-ttl");
  SyncRes::s_packetcacheservfailttl=::arg().asNum("packetcache-servfail-ttl");
  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_rootNXTrust = ::arg().mustDo( "root-nx-trust");
  if(SyncRes::s_serverID.empty()) {
    char tmp[128];
    gethostname(tmp, sizeof(tmp)-1);
    SyncRes::s_serverID=tmp;
  }

  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");

  makeUDPServerSockets();
  makeTCPServerSockets();

  parseEDNSSubnetWhitelist(::arg()["edns-subnet-whitelist"]);

  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();
  }
  signal(SIGUSR1,usr1Handler);
  signal(SIGUSR2,usr2Handler);
  signal(SIGPIPE,SIG_IGN);
  g_numThreads = ::arg().asNum("threads") + ::arg().mustDo("pdns-distributes-queries");
  g_numWorkerThreads = ::arg().asNum("threads");
  g_maxMThreads = ::arg().asNum("max-mthreads");
  checkOrFixFDS();

  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()) {
    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");

  if(g_numThreads == 1) {
    L<<Logger::Warning<<"Operating unthreaded"<<endl;
    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);
    }
    void* res;


    pthread_join(tid, &res);
  }
  return 0;
}

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..
  t_sstorage->domainmap = g_initialDomainMap;
  t_allowFrom = g_initialAllowFrom;
  t_udpclientsocks = new UDPClientSocks();
  t_tcpClientCounts = new tcpClientCounts_t();
  primeHints();

  t_packetCache = new RecursorPacketCache();

  L<<Logger::Warning<<"Done priming cache with root hints"<<endl;

  t_pdl = new shared_ptr<RecursorLua4>();

  try {
    if(!::arg()["lua-dns-script"].empty()) {
      *t_pdl = shared_ptr<RecursorLua4>(new 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);
  }

  t_traceRegex = new shared_ptr<Regex>();
  unsigned int ringsize=::arg().asNum("stats-ringbuffer-entries") / g_numWorkerThreads;
  if(ringsize) {
    t_remotes = 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 = new addrringbuf_t();
    t_servfailremotes->set_capacity(ringsize);
    t_largeanswerremotes = new addrringbuf_t();
    t_largeanswerremotes->set_capacity(ringsize);

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

  MT=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_weDistributeQueries || !t_id)  // if we distribute queries, only t_id = 0 listens
    for(deferredAdd_t::const_iterator i=deferredAdd.begin(); i!=deferredAdd.end(); ++i)
      t_fdm->addReadFD(i->first, i->second);

  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=AtomicCounter(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 (default)/log-fail/validate")="process";
    ::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")="4";
    ::arg().set("log-common-errors","If we should log rather common errors")="yes";
    ::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 nummer 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";
    ::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")="";
    ::arg().set("carbon-interval", "Number of seconds between carbon (graphite) updates")="30";
    ::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("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")="";
    ::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("edns-subnet-whitelist", "List of netmasks and domains that we should enable EDNS subnet for")="powerdns.com,82.94.213.34,2001:888:2000:1d::2";
    ::arg().setSwitch( "pdns-distributes-queries", "If PowerDNS itself should distribute queries over threads")="";
    ::arg().setSwitch( "root-nx-trust", "If set, believe that an NXDOMAIN from the root means the TLD does not exist")="no";
    ::arg().setSwitch( "any-to-tcp","Answer ANY queries with tc=1, shunting to TCP" )="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("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().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(99);
    }

    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;
}