pdns/ixfrdist.cc

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25 #include <boost/program_options.hpp>
  26 #include <arpa/inet.h>
  27 #include <sys/types.h>
  28 #include <grp.h>
  29 #include <pwd.h>
  30 #include <sys/stat.h>
  31 #include <mutex>
  32 #include <thread>
  33 #include <pthread.h>
  34 #include <dirent.h>
  35 #include <queue>
  36 #include <condition_variable>
  37 #include "ixfr.hh"
  38 #include "ixfrutils.hh"
  39 #include "resolver.hh"
  40 #include "dns_random.hh"
  41 #include "sstuff.hh"
  42 #include "mplexer.hh"
  43 #include "misc.hh"
  44 #include "iputils.hh"
  45 #include "logger.hh"
  46 #include <yaml-cpp/yaml.h>
  47
  48 /* BEGIN Needed because of deeper dependencies */
  49 #include "arguments.hh"
  50 #include "statbag.hh"
  51 StatBag S;
  52
  53 ArgvMap &arg()
  54 {
  55   static ArgvMap theArg;
  56   return theArg;
  57 }
  58 /* END Needed because of deeper dependencies */
  59
  60 // Allows reading/writing ComboAddresses and DNSNames in YAML-cpp
  61 namespace YAML {
  62 template<>
  63 struct convert<ComboAddress> {
  64   static Node encode(const ComboAddress& rhs) {
  65     return Node(rhs.toStringWithPort());
  66   }
  67   static bool decode(const Node& node, ComboAddress& rhs) {
  68     if (!node.IsScalar()) {
  69       return false;
  70     }
  71     try {
  72       rhs = ComboAddress(node.as<string>(), 53);
  73       return true;
  74     } catch(const runtime_error &e) {
  75       return false;
  76     } catch (const PDNSException &e) {
  77       return false;
  78     }
  79   }
  80 };
  81
  82 template<>
  83 struct convert<DNSName> {
  84   static Node encode(const DNSName& rhs) {
  85     return Node(rhs.toStringRootDot());
  86   }
  87   static bool decode(const Node& node, DNSName& rhs) {
  88     if (!node.IsScalar()) {
  89       return false;
  90     }
  91     try {
  92       rhs = DNSName(node.as<string>());
  93       return true;
  94     } catch(const runtime_error &e) {
  95       return false;
  96     } catch (const PDNSException &e) {
  97       return false;
  98     }
  99   }
 100 };
 101 } // namespace YAML
 102
 103 struct ixfrdiff_t {
 104   shared_ptr<SOARecordContent> oldSOA;
 105   shared_ptr<SOARecordContent> newSOA;
 106   vector<DNSRecord> removals;
 107   vector<DNSRecord> additions;
 108 };
 109
 110 struct ixfrinfo_t {
 111   shared_ptr<SOARecordContent> soa; // The SOA of the latestAXFR
 112   records_t latestAXFR;             // The most recent AXFR
 113   vector<std::shared_ptr<ixfrdiff_t>> ixfrDiffs;
 114 };
 115
 116 // Why a struct? This way we can add more options to a domain in the future
 117 struct ixfrdistdomain_t {
 118   set<ComboAddress> masters; // A set so we can do multiple master addresses in the future
 119 };
 120
 121 // This contains the configuration for each domain
 122 static map<DNSName, ixfrdistdomain_t> g_domainConfigs;
 123
 124 // Map domains and their data
 125 static std::map<DNSName, std::shared_ptr<ixfrinfo_t>> g_soas;
 126 static std::mutex g_soas_mutex;
 127
 128 // Condition variable for TCP handling
 129 static std::condition_variable g_tcpHandlerCV;
 130 static std::queue<pair<int, ComboAddress>> g_tcpRequestFDs;
 131 static std::mutex g_tcpRequestFDsMutex;
 132
 133 namespace po = boost::program_options;
 134
 135 static bool g_exiting = false;
 136
 137 static NetmaskGroup g_acl;
 138 static bool g_compress = false;
 139
 140 static void handleSignal(int signum) {
 141   g_log<<Logger::Notice<<"Got "<<strsignal(signum)<<" signal";
 142   if (g_exiting) {
 143     g_log<<Logger::Notice<<", this is the second time we were asked to stop, forcefully exiting"<<endl;
 144     exit(EXIT_FAILURE);
 145   }
 146   g_log<<Logger::Notice<<", stopping, this may take a few second due to in-progress transfers and cleanup. Send this signal again to forcefully stop"<<endl;
 147   g_exiting = true;
 148 }
 149
 150 static void usage(po::options_description &desc) {
 151   cerr << "Usage: ixfrdist [OPTION]..."<<endl;
 152   cerr << desc << "\n";
 153 }
 154
 155 // The compiler does not like using rfc1982LessThan in std::sort directly
 156 static bool sortSOA(uint32_t i, uint32_t j) {
 157   return rfc1982LessThan(i, j);
 158 }
 159
 160 static void cleanUpDomain(const DNSName& domain, const uint16_t& keep, const string& workdir) {
 161   string dir = workdir + "/" + domain.toString();
 162   DIR *dp;
 163   dp = opendir(dir.c_str());
 164   if (dp == nullptr) {
 165     return;
 166   }
 167   vector<uint32_t> zoneVersions;
 168   struct dirent *d;
 169   while ((d = readdir(dp)) != nullptr) {
 170     if(!strcmp(d->d_name, ".") || !strcmp(d->d_name, "..")) {
 171       continue;
 172     }
 173     zoneVersions.push_back(std::stoi(d->d_name));
 174   }
 175   closedir(dp);
 176   g_log<<Logger::Info<<"Found "<<zoneVersions.size()<<" versions of "<<domain<<", asked to keep "<<keep<<", ";
 177   if (zoneVersions.size() <= keep) {
 178     g_log<<Logger::Info<<"not cleaning up"<<endl;
 179     return;
 180   }
 181   g_log<<Logger::Info<<"cleaning up the oldest "<<zoneVersions.size() - keep<<endl;
 182
 183   // Sort the versions
 184   std::sort(zoneVersions.begin(), zoneVersions.end(), sortSOA);
 185
 186   // And delete all the old ones
 187   {
 188     // Lock to ensure no one reads this.
 189     std::lock_guard<std::mutex> guard(g_soas_mutex);
 190     for (auto iter = zoneVersions.cbegin(); iter != zoneVersions.cend() - keep; ++iter) {
 191       string fname = dir + "/" + std::to_string(*iter);
 192       g_log<<Logger::Debug<<"Removing "<<fname<<endl;
 193       unlink(fname.c_str());
 194     }
 195   }
 196 }
 197
 198 static shared_ptr<SOARecordContent> getSOAFromRecords(const records_t& records) {
 199   for (const auto& dnsrecord : records) {
 200     if (dnsrecord.d_type == QType::SOA) {
 201       auto soa = getRR<SOARecordContent>(dnsrecord);
 202       if (soa == nullptr) {
 203         throw PDNSException("Unable to determine SOARecordContent from old records");
 204       }
 205       return soa;
 206     }
 207   }
 208   throw PDNSException("No SOA in supplied records");
 209 }
 210
 211 static void makeIXFRDiff(const records_t& from, const records_t& to, std::shared_ptr<ixfrdiff_t>& diff, const shared_ptr<SOARecordContent>& fromSOA = nullptr, const shared_ptr<SOARecordContent>& toSOA = nullptr) {
 212   set_difference(from.cbegin(), from.cend(), to.cbegin(), to.cend(), back_inserter(diff->removals), from.value_comp());
 213   set_difference(to.cbegin(), to.cend(), from.cbegin(), from.cend(), back_inserter(diff->additions), from.value_comp());
 214   diff->oldSOA = fromSOA;
 215   if (fromSOA == nullptr) {
 216     diff->oldSOA = getSOAFromRecords(from);
 217   }
 218   diff->newSOA = toSOA;
 219   if (toSOA == nullptr) {
 220     diff->newSOA = getSOAFromRecords(to);
 221   }
 222 }
 223
 224 /* you can _never_ alter the content of the resulting shared pointer */
 225 static std::shared_ptr<ixfrinfo_t> getCurrentZoneInfo(const DNSName& domain)
 226 {
 227   std::lock_guard<std::mutex> guard(g_soas_mutex);
 228   return g_soas[domain];
 229 }
 230
 231 static void updateCurrentZoneInfo(const DNSName& domain, std::shared_ptr<ixfrinfo_t>& newInfo)
 232 {
 233   std::lock_guard<std::mutex> guard(g_soas_mutex);
 234   g_soas[domain] = newInfo;
 235 }
 236
 237 void updateThread(const string& workdir, const uint16_t& keep, const uint16_t& axfrTimeout) {
 238   string threadName = "ixfrdist/update";
 239   auto retval = pthread_setname_np(pthread_self(), const_cast<char*>(threadName.c_str()));
 240   if (retval != 0) {
 241     g_log<<Logger::Warning<<"Could not set thread name "<<threadName<<" for update thread: "<<strerror(retval)<<endl;
 242   }
 243   std::map<DNSName, time_t> lastCheck;
 244
 245   // Initialize the serials we have
 246   for (const auto &domainConfig : g_domainConfigs) {
 247     DNSName domain = domainConfig.first;
 248     lastCheck[domain] = 0;
 249     string dir = workdir + "/" + domain.toString();
 250     try {
 251       g_log<<Logger::Info<<"Trying to initially load domain "<<domain<<" from disk"<<endl;
 252       auto serial = getSerialsFromDir(dir);
 253       shared_ptr<SOARecordContent> soa;
 254       {
 255         string fname = workdir + "/" + domain.toString() + "/" + std::to_string(serial);
 256         loadSOAFromDisk(domain, fname, soa);
 257         records_t records;
 258         if (soa != nullptr) {
 259           loadZoneFromDisk(records, fname, domain);
 260         }
 261         auto zoneInfo = std::make_shared<ixfrinfo_t>();
 262         zoneInfo->latestAXFR = std::move(records);
 263         zoneInfo->soa = soa;
 264         updateCurrentZoneInfo(domain, zoneInfo);
 265       }
 266       if (soa != nullptr) {
 267         g_log<<Logger::Notice<<"Loaded zone "<<domain<<" with serial "<<soa->d_st.serial<<endl;
 268         // Initial cleanup
 269         cleanUpDomain(domain, keep, workdir);
 270       }
 271     } catch (runtime_error &e) {
 272       // Most likely, the directory does not exist.
 273       g_log<<Logger::Info<<e.what()<<", attempting to create"<<endl;
 274       // Attempt to create it, if _that_ fails, there is no hope
 275       if (mkdir(dir.c_str(), 0777) == -1 && errno != EEXIST) {
 276         g_log<<Logger::Error<<"Could not create '"<<dir<<"': "<<strerror(errno)<<endl;
 277         exit(EXIT_FAILURE);
 278       }
 279     }
 280   }
 281
 282   g_log<<Logger::Notice<<"Update Thread started"<<endl;
 283
 284   while (true) {
 285     if (g_exiting) {
 286       g_log<<Logger::Notice<<"UpdateThread stopped"<<endl;
 287       break;
 288     }
 289     time_t now = time(nullptr);
 290     for (const auto &domainConfig : g_domainConfigs) {
 291
 292       if (g_exiting) {
 293         break;
 294       }
 295
 296       DNSName domain = domainConfig.first;
 297       shared_ptr<SOARecordContent> current_soa;
 298       const auto& zoneInfo = getCurrentZoneInfo(domain);
 299       if (zoneInfo != nullptr) {
 300         current_soa = zoneInfo->soa;
 301       }
 302
 303       auto& zoneLastCheck = lastCheck[domain];
 304       if ((current_soa != nullptr && now - zoneLastCheck < current_soa->d_st.refresh) || // Only check if we have waited `refresh` seconds
 305           (current_soa == nullptr && now - zoneLastCheck < 30))  {                       // Or if we could not get an update at all still, every 30 seconds
 306         continue;
 307       }
 308
 309       // TODO Keep track of 'down' masters
 310       set<ComboAddress>::const_iterator it(domainConfig.second.masters.begin());
 311       std::advance(it, random() % domainConfig.second.masters.size());
 312       ComboAddress master = *it;
 313
 314       string dir = workdir + "/" + domain.toString();
 315       g_log<<Logger::Info<<"Attempting to retrieve SOA Serial update for '"<<domain<<"' from '"<<master.toStringWithPort()<<"'"<<endl;
 316       shared_ptr<SOARecordContent> sr;
 317       try {
 318         zoneLastCheck = now;
 319         auto newSerial = getSerialFromMaster(master, domain, sr); // TODO TSIG
 320         if(current_soa != nullptr) {
 321           g_log<<Logger::Info<<"Got SOA Serial for "<<domain<<" from "<<master.toStringWithPort()<<": "<< newSerial<<", had Serial: "<<current_soa->d_st.serial;
 322           if (newSerial == current_soa->d_st.serial) {
 323             g_log<<Logger::Info<<", not updating."<<endl;
 324             continue;
 325           }
 326           g_log<<Logger::Info<<", will update."<<endl;
 327         }
 328       } catch (runtime_error &e) {
 329         g_log<<Logger::Warning<<"Unable to get SOA serial update for '"<<domain<<"' from master "<<master.toStringWithPort()<<": "<<e.what()<<endl;
 330         continue;
 331       }
 332       // Now get the full zone!
 333       g_log<<Logger::Info<<"Attempting to receive full zonedata for '"<<domain<<"'"<<endl;
 334       ComboAddress local = master.isIPv4() ? ComboAddress("0.0.0.0") : ComboAddress("::");
 335       TSIGTriplet tt;
 336
 337       // The *new* SOA
 338       shared_ptr<SOARecordContent> soa;
 339       records_t records;
 340       try {
 341         AXFRRetriever axfr(master, domain, tt, &local);
 342         unsigned int nrecords=0;
 343         Resolver::res_t nop;
 344         vector<DNSRecord> chunk;
 345         time_t t_start = time(nullptr);
 346         time_t axfr_now = time(nullptr);
 347         while(axfr.getChunk(nop, &chunk, (axfr_now - t_start + axfrTimeout))) {
 348           for(auto& dr : chunk) {
 349             if(dr.d_type == QType::TSIG)
 350               continue;
 351             dr.d_name.makeUsRelative(domain);
 352             records.insert(dr);
 353             nrecords++;
 354             if (dr.d_type == QType::SOA) {
 355               soa = getRR<SOARecordContent>(dr);
 356             }
 357           }
 358           axfr_now = time(nullptr);
 359           if (axfr_now - t_start > axfrTimeout) {
 360             throw PDNSException("Total AXFR time exceeded!");
 361           }
 362         }
 363         if (soa == nullptr) {
 364           g_log<<Logger::Warning<<"No SOA was found in the AXFR of "<<domain<<endl;
 365           continue;
 366         }
 367         g_log<<Logger::Notice<<"Retrieved all zone data for "<<domain<<". Received "<<nrecords<<" records."<<endl;
 368       } catch (PDNSException &e) {
 369         g_log<<Logger::Warning<<"Could not retrieve AXFR for '"<<domain<<"': "<<e.reason<<endl;
 370         continue;
 371       } catch (runtime_error &e) {
 372         g_log<<Logger::Warning<<"Could not retrieve AXFR for zone '"<<domain<<"': "<<e.what()<<endl;
 373         continue;
 374       }
 375
 376       try {
 377
 378         writeZoneToDisk(records, domain, dir);
 379         g_log<<Logger::Notice<<"Wrote zonedata for "<<domain<<" with serial "<<soa->d_st.serial<<" to "<<dir<<endl;
 380
 381         const auto oldZoneInfo = getCurrentZoneInfo(domain);
 382         auto zoneInfo = std::make_shared<ixfrinfo_t>();
 383
 384         if (oldZoneInfo && !oldZoneInfo->latestAXFR.empty()) {
 385           auto diff = std::make_shared<ixfrdiff_t>();
 386           zoneInfo->ixfrDiffs = oldZoneInfo->ixfrDiffs;
 387           g_log<<Logger::Debug<<"Calculating diff for "<<domain<<endl;
 388           makeIXFRDiff(oldZoneInfo->latestAXFR, records, diff, oldZoneInfo->soa, soa);
 389           g_log<<Logger::Debug<<"Calculated diff for "<<domain<<", we had "<<diff->removals.size()<<" removals and "<<diff->additions.size()<<" additions"<<endl;
 390           zoneInfo->ixfrDiffs.push_back(std::move(diff));
 391         }
 392
 393         // Clean up the diffs
 394         while (zoneInfo->ixfrDiffs.size() > keep) {
 395           zoneInfo->ixfrDiffs.erase(zoneInfo->ixfrDiffs.begin());
 396         }
 397
 398         g_log<<Logger::Debug<<"Zone "<<domain<<" previously contained "<<(oldZoneInfo ? oldZoneInfo->latestAXFR.size() : 0)<<" entries, "<<records.size()<<" now"<<endl;
 399         zoneInfo->latestAXFR = std::move(records);
 400         zoneInfo->soa = soa;
 401         updateCurrentZoneInfo(domain, zoneInfo);
 402       } catch (PDNSException &e) {
 403         g_log<<Logger::Warning<<"Could not save zone '"<<domain<<"' to disk: "<<e.reason<<endl;
 404       } catch (runtime_error &e) {
 405         g_log<<Logger::Warning<<"Could not save zone '"<<domain<<"' to disk: "<<e.what()<<endl;
 406       }
 407
 408       // Now clean up the directory
 409       cleanUpDomain(domain, keep, workdir);
 410     } /* for (const auto &domain : domains) */
 411     sleep(1);
 412   } /* while (true) */
 413 } /* updateThread */
 414
 415 static bool checkQuery(const MOADNSParser& mdp, const ComboAddress& saddr, const bool udp = true, const string& logPrefix="") {
 416   vector<string> info_msg;
 417
 418   g_log<<Logger::Debug<<logPrefix<<"Had "<<mdp.d_qname<<"|"<<QType(mdp.d_qtype).getName()<<" query from "<<saddr.toStringWithPort()<<endl;
 419
 420   if (udp && mdp.d_qtype != QType::SOA && mdp.d_qtype != QType::IXFR) {
 421     info_msg.push_back("QType is unsupported (" + QType(mdp.d_qtype).getName() + " is not in {SOA,IXFR})");
 422   }
 423
 424   if (!udp && mdp.d_qtype != QType::SOA && mdp.d_qtype != QType::IXFR && mdp.d_qtype != QType::AXFR) {
 425     info_msg.push_back("QType is unsupported (" + QType(mdp.d_qtype).getName() + " is not in {SOA,IXFR,AXFR})");
 426   }
 427
 428   {
 429     if (g_domainConfigs.find(mdp.d_qname) == g_domainConfigs.end()) {
 430       info_msg.push_back("Domain name '" + mdp.d_qname.toLogString() + "' is not configured for distribution");
 431     }
 432
 433     const auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 434     if (zoneInfo == nullptr) {
 435       info_msg.push_back("Domain has not been transferred yet");
 436     }
 437   }
 438
 439   if (!info_msg.empty()) {
 440     g_log<<Logger::Warning<<logPrefix<<"Ignoring "<<mdp.d_qname<<"|"<<QType(mdp.d_qtype).getName()<<" query from "<<saddr.toStringWithPort();
 441     g_log<<Logger::Warning<<": ";
 442     bool first = true;
 443     for (const auto& s : info_msg) {
 444       if (!first) {
 445         g_log<<Logger::Warning<<", ";
 446         first = false;
 447       }
 448       g_log<<Logger::Warning<<s;
 449     }
 450     g_log<<Logger::Warning<<endl;
 451     return false;
 452   }
 453
 454   return true;
 455 }
 456
 457 /*
 458  * Returns a vector<uint8_t> that represents the full response to a SOA
 459  * query. QNAME is read from mdp.
 460  */
 461 static bool makeSOAPacket(const MOADNSParser& mdp, vector<uint8_t>& packet) {
 462
 463   auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 464   if (zoneInfo == nullptr) {
 465     return false;
 466   }
 467
 468   DNSPacketWriter pw(packet, mdp.d_qname, mdp.d_qtype);
 469   pw.getHeader()->id = mdp.d_header.id;
 470   pw.getHeader()->rd = mdp.d_header.rd;
 471   pw.getHeader()->qr = 1;
 472
 473   pw.startRecord(mdp.d_qname, QType::SOA);
 474   zoneInfo->soa->toPacket(pw);
 475   pw.commit();
 476
 477   return true;
 478 }
 479
 480 static vector<uint8_t> getSOAPacket(const MOADNSParser& mdp, const shared_ptr<SOARecordContent>& soa) {
 481   vector<uint8_t> packet;
 482   DNSPacketWriter pw(packet, mdp.d_qname, mdp.d_qtype);
 483   pw.getHeader()->id = mdp.d_header.id;
 484   pw.getHeader()->rd = mdp.d_header.rd;
 485   pw.getHeader()->qr = 1;
 486
 487   // Add the first SOA
 488   pw.startRecord(mdp.d_qname, QType::SOA);
 489   soa->toPacket(pw);
 490   pw.commit();
 491   return packet;
 492 }
 493
 494 static bool sendPacketOverTCP(int fd, const std::vector<uint8_t>& packet)
 495 {
 496   char sendBuf[2];
 497   sendBuf[0]=packet.size()/256;
 498   sendBuf[1]=packet.size()%256;
 499
 500   ssize_t send = writen2(fd, sendBuf, 2);
 501   send += writen2(fd, &packet[0], packet.size());
 502   return true;
 503 }
 504
 505 static bool addRecordToWriter(DNSPacketWriter& pw, const DNSName& zoneName, const DNSRecord& record, bool compress)
 506 {
 507   pw.startRecord(record.d_name + zoneName, record.d_type, record.d_ttl, QClass::IN, DNSResourceRecord::ANSWER, compress);
 508   record.d_content->toPacket(pw);
 509   if (pw.size() > 65535) {
 510     pw.rollback();
 511     return false;
 512   }
 513   return true;
 514 }
 515
 516 template <typename T> static bool sendRecordsOverTCP(int fd, const MOADNSParser& mdp, const T& records)
 517 {
 518   vector<uint8_t> packet;
 519
 520   for (auto it = records.cbegin(); it != records.cend();) {
 521     bool recordsAdded = false;
 522     packet.clear();
 523     DNSPacketWriter pw(packet, mdp.d_qname, mdp.d_qtype);
 524     pw.getHeader()->id = mdp.d_header.id;
 525     pw.getHeader()->rd = mdp.d_header.rd;
 526     pw.getHeader()->qr = 1;
 527
 528     while (it != records.cend()) {
 529       if (it->d_type == QType::SOA) {
 530         it++;
 531         continue;
 532       }
 533
 534       if (addRecordToWriter(pw, mdp.d_qname, *it, g_compress)) {
 535         recordsAdded = true;
 536         it++;
 537       }
 538       else {
 539         if (recordsAdded) {
 540           pw.commit();
 541           sendPacketOverTCP(fd, packet);
 542         }
 543         if (it == records.cbegin()) {
 544           /* something is wrong */
 545           return false;
 546         }
 547
 548         break;
 549       }
 550     }
 551
 552     if (it == records.cend() && recordsAdded) {
 553       pw.commit();
 554       sendPacketOverTCP(fd, packet);
 555     }
 556   }
 557
 558   return true;
 559 }
 560
 561
 562 static bool handleAXFR(int fd, const MOADNSParser& mdp) {
 563   /* we get a shared pointer of the zone info that we can't modify, ever.
 564      A newer one may arise in the meantime, but this one will stay valid
 565      until we release it.
 566   */
 567   auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 568   if (zoneInfo == nullptr) {
 569     return false;
 570   }
 571
 572   shared_ptr<SOARecordContent> soa = zoneInfo->soa;
 573   const records_t& records = zoneInfo->latestAXFR;
 574
 575   // Initial SOA
 576   const auto soaPacket = getSOAPacket(mdp, soa);
 577   if (!sendPacketOverTCP(fd, soaPacket)) {
 578     return false;
 579   }
 580
 581   if (!sendRecordsOverTCP(fd, mdp, records)) {
 582     return false;
 583   }
 584
 585   // Final SOA
 586   if (!sendPacketOverTCP(fd, soaPacket)) {
 587     return false;
 588   }
 589
 590   return true;
 591 }
 592
 593 /* Produces an IXFR if one can be made according to the rules in RFC 1995 and
 594  * creates a SOA or AXFR packet when required by the RFC.
 595  */
 596 static bool handleIXFR(int fd, const ComboAddress& destination, const MOADNSParser& mdp, const shared_ptr<SOARecordContent>& clientSOA) {
 597   vector<std::shared_ptr<ixfrdiff_t>> toSend;
 598
 599   /* we get a shared pointer of the zone info that we can't modify, ever.
 600      A newer one may arise in the meantime, but this one will stay valid
 601      until we release it.
 602   */
 603   auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 604   if (zoneInfo == nullptr) {
 605     return false;
 606   }
 607
 608   uint32_t ourLatestSerial = zoneInfo->soa->d_st.serial;
 609
 610   if (rfc1982LessThan(ourLatestSerial, clientSOA->d_st.serial) || ourLatestSerial == clientSOA->d_st.serial) {
 611     /* RFC 1995 Section 2
 612      *    If an IXFR query with the same or newer version number than that of
 613      *    the server is received, it is replied to with a single SOA record of
 614      *    the server's current version, just as in AXFR.
 615      */
 616     vector<uint8_t> packet;
 617     bool ret = makeSOAPacket(mdp, packet);
 618     if (ret) {
 619       sendPacketOverTCP(fd, packet);
 620     }
 621     return ret;
 622   }
 623
 624   // as we use push_back in the updater, we know the vector is sorted as oldest first
 625   bool shouldAdd = false;
 626   // Get all relevant IXFR differences
 627   for (const auto& diff : zoneInfo->ixfrDiffs) {
 628     if (shouldAdd) {
 629       toSend.push_back(diff);
 630       continue;
 631     }
 632     if (diff->oldSOA->d_st.serial == clientSOA->d_st.serial) {
 633       toSend.push_back(diff);
 634       // Add all consecutive diffs
 635       shouldAdd = true;
 636     }
 637   }
 638
 639   if (toSend.empty()) {
 640     g_log<<Logger::Warning<<"No IXFR available from serial "<<clientSOA->d_st.serial<<" for zone "<<mdp.d_qname<<", attempting to send AXFR"<<endl;
 641     return handleAXFR(fd, mdp);
 642   }
 643
 644   std::vector<std::vector<uint8_t>> packets;
 645   for (const auto& diff : toSend) {
 646     /* An IXFR packet's ANSWER section looks as follows:
 647      * SOA new_serial
 648      * SOA old_serial
 649      * ... removed records ...
 650      * SOA new_serial
 651      * ... added records ...
 652      * SOA new_serial
 653      */
 654
 655     const auto newSOAPacket = getSOAPacket(mdp, diff->newSOA);
 656     const auto oldSOAPacket = getSOAPacket(mdp, diff->oldSOA);
 657
 658     if (!sendPacketOverTCP(fd, newSOAPacket)) {
 659       return false;
 660     }
 661
 662     if (!sendPacketOverTCP(fd, oldSOAPacket)) {
 663       return false;
 664     }
 665
 666     if (!sendRecordsOverTCP(fd, mdp, diff->removals)) {
 667       return false;
 668     }
 669
 670     if (!sendPacketOverTCP(fd, newSOAPacket)) {
 671       return false;
 672     }
 673
 674     if (!sendRecordsOverTCP(fd, mdp, diff->additions)) {
 675       return false;
 676     }
 677
 678     if (!sendPacketOverTCP(fd, newSOAPacket)) {
 679       return false;
 680     }
 681   }
 682
 683   return true;
 684 }
 685
 686 static bool allowedByACL(const ComboAddress& addr) {
 687   return g_acl.match(addr);
 688 }
 689
 690 static void handleUDPRequest(int fd, boost::any&) {
 691   // TODO make the buffer-size configurable
 692   char buf[4096];
 693   ComboAddress saddr;
 694   socklen_t fromlen = sizeof(saddr);
 695   int res = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr*) &saddr, &fromlen);
 696
 697   if (res == 0) {
 698     g_log<<Logger::Warning<<"Got an empty message from "<<saddr.toStringWithPort()<<endl;
 699     return;
 700   }
 701
 702   if(res < 0) {
 703     auto savedErrno = errno;
 704     g_log<<Logger::Warning<<"Could not read message from "<<saddr.toStringWithPort()<<": "<<strerror(savedErrno)<<endl;
 705     return;
 706   }
 707
 708   if (saddr == ComboAddress("0.0.0.0", 0)) {
 709     g_log<<Logger::Warning<<"Could not determine source of message"<<endl;
 710     return;
 711   }
 712
 713   if (!allowedByACL(saddr)) {
 714     g_log<<Logger::Warning<<"UDP query from "<<saddr.toString()<<" is not allowed, dropping"<<endl;
 715     return;
 716   }
 717
 718   MOADNSParser mdp(true, string(buf, res));
 719   if (!checkQuery(mdp, saddr)) {
 720     return;
 721   }
 722
 723   /* RFC 1995 Section 2
 724    *    Transport of a query may be by either UDP or TCP.  If an IXFR query
 725    *    is via UDP, the IXFR server may attempt to reply using UDP if the
 726    *    entire response can be contained in a single DNS packet.  If the UDP
 727    *    reply does not fit, the query is responded to with a single SOA
 728    *    record of the server's current version to inform the client that a
 729    *    TCP query should be initiated.
 730    *
 731    * Let's not complicate this with IXFR over UDP (and looking if we need to truncate etc).
 732    * Just send the current SOA and let the client try over TCP
 733    */
 734   vector<uint8_t> packet;
 735   makeSOAPacket(mdp, packet);
 736   if(sendto(fd, &packet[0], packet.size(), 0, (struct sockaddr*) &saddr, fromlen) < 0) {
 737     auto savedErrno = errno;
 738     g_log<<Logger::Warning<<"Could not send reply for "<<mdp.d_qname<<"|"<<QType(mdp.d_qtype).getName()<<" to "<<saddr.toStringWithPort()<<": "<<strerror(savedErrno)<<endl;
 739   }
 740   return;
 741 }
 742
 743 static void handleTCPRequest(int fd, boost::any&) {
 744   ComboAddress saddr;
 745   int cfd = 0;
 746
 747   try {
 748     cfd = SAccept(fd, saddr);
 749     setBlocking(cfd);
 750   } catch(runtime_error &e) {
 751     g_log<<Logger::Error<<e.what()<<endl;
 752     return;
 753   }
 754
 755   if (saddr == ComboAddress("0.0.0.0", 0)) {
 756     g_log<<Logger::Warning<<"Could not determine source of message"<<endl;
 757     close(cfd);
 758     return;
 759   }
 760
 761   if (!allowedByACL(saddr)) {
 762     g_log<<Logger::Warning<<"TCP query from "<<saddr.toString()<<" is not allowed, dropping"<<endl;
 763     close(cfd);
 764     return;
 765   }
 766
 767   {
 768     std::lock_guard<std::mutex> lg(g_tcpRequestFDsMutex);
 769     g_tcpRequestFDs.push({cfd, saddr});
 770   }
 771   g_tcpHandlerCV.notify_one();
 772 }
 773
 774 /* Thread to handle TCP traffic
 775  */
 776 static void tcpWorker(int tid) {
 777   string threadName = "ixfrdist/tcpWor";
 778   auto retval = pthread_setname_np(pthread_self(), const_cast<char*>(threadName.c_str()));
 779   if (retval != 0) {
 780     g_log<<Logger::Warning<<"Could not set thread name "<<threadName<<" for update thread: "<<strerror(retval)<<endl;
 781   }
 782   string prefix = "TCP Worker " + std::to_string(tid) + ": ";
 783
 784   while(true) {
 785     g_log<<Logger::Debug<<prefix<<"ready for a new request!"<<endl;
 786     std::unique_lock<std::mutex> lk(g_tcpRequestFDsMutex);
 787     g_tcpHandlerCV.wait(lk, []{return g_tcpRequestFDs.size() || g_exiting ;});
 788     if (g_exiting) {
 789       g_log<<Logger::Debug<<prefix<<"Stopping thread"<<endl;
 790       break;
 791     }
 792     g_log<<Logger::Debug<<prefix<<"Going to handle a query"<<endl;
 793     auto request = g_tcpRequestFDs.front();
 794     g_tcpRequestFDs.pop();
 795     lk.unlock();
 796
 797     int cfd = request.first;
 798     ComboAddress saddr = request.second;
 799
 800     char buf[4096];
 801     ssize_t res;
 802     try {
 803       uint16_t toRead;
 804       readn2(cfd, &toRead, sizeof(toRead));
 805       toRead = std::min(ntohs(toRead), static_cast<uint16_t>(sizeof(buf)));
 806       res = readn2WithTimeout(cfd, &buf, toRead, 2);
 807       g_log<<Logger::Debug<<prefix<<"Had message of "<<std::to_string(toRead)<<" bytes from "<<saddr.toStringWithPort()<<endl;
 808     } catch (runtime_error &e) {
 809       g_log<<Logger::Warning<<prefix<<"Could not read message from "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
 810       close(cfd);
 811       continue;
 812     }
 813
 814     try {
 815       MOADNSParser mdp(true, string(buf, res));
 816
 817       if (!checkQuery(mdp, saddr, false, prefix)) {
 818         close(cfd);
 819         continue;
 820       }
 821
 822       if (mdp.d_qtype == QType::SOA) {
 823         vector<uint8_t> packet;
 824         bool ret = makeSOAPacket(mdp, packet);
 825         if (!ret) {
 826           close(cfd);
 827           continue;
 828         }
 829         sendPacketOverTCP(cfd, packet);
 830       }
 831       else if (mdp.d_qtype == QType::AXFR) {
 832         if (!handleAXFR(cfd, mdp)) {
 833           close(cfd);
 834           continue;
 835         }
 836       }
 837       else if (mdp.d_qtype == QType::IXFR) {
 838         /* RFC 1995 section 3:
 839          *  The IXFR query packet format is the same as that of a normal DNS
 840          *  query, but with the query type being IXFR and the authority section
 841          *  containing the SOA record of client's version of the zone.
 842          */
 843         shared_ptr<SOARecordContent> clientSOA;
 844         for (auto &answer : mdp.d_answers) {
 845           // from dnsparser.hh:
 846           // typedef vector<pair<DNSRecord, uint16_t > > answers_t;
 847           if (answer.first.d_type == QType::SOA && answer.first.d_place == DNSResourceRecord::AUTHORITY) {
 848             clientSOA = getRR<SOARecordContent>(answer.first);
 849             if (clientSOA != nullptr) {
 850               break;
 851             }
 852           }
 853         } /* for (auto const &answer : mdp.d_answers) */
 854
 855         if (clientSOA == nullptr) {
 856           g_log<<Logger::Warning<<prefix<<"IXFR request packet did not contain a SOA record in the AUTHORITY section"<<endl;
 857           close(cfd);
 858           continue;
 859         }
 860
 861         if (!handleIXFR(cfd, saddr, mdp, clientSOA)) {
 862           close(cfd);
 863           continue;
 864         }
 865       } /* if (mdp.d_qtype == QType::IXFR) */
 866
 867       shutdown(cfd, 2);
 868     } catch (MOADNSException &e) {
 869       g_log<<Logger::Warning<<prefix<<"Could not parse DNS packet from "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
 870     } catch (runtime_error &e) {
 871       g_log<<Logger::Warning<<prefix<<"Could not write reply to "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
 872     }
 873     // bye!
 874     close(cfd);
 875
 876     if (g_exiting) {
 877       break;
 878     }
 879   }
 880 }
 881
 882 /* Parses the configuration file in configpath into config, adding defaults for
 883  * missing parameters (if applicable), returning true if the config file was
 884  * good, false otherwise. Will log all issues with the config
 885  */
 886 static bool parseAndCheckConfig(const string& configpath, YAML::Node& config) {
 887   g_log<<Logger::Info<<"Loading configuration file from "<<configpath<<endl;
 888   try {
 889     config = YAML::LoadFile(configpath);
 890   } catch (const runtime_error &e) {
 891     g_log<<Logger::Error<<"Unable to load configuration file '"<<configpath<<"': "<<e.what()<<endl;
 892     return false;
 893   }
 894
 895   bool retval = true;
 896
 897   if (config["keep"]) {
 898     try {
 899       config["keep"].as<uint16_t>();
 900     } catch (const runtime_error &e) {
 901       g_log<<Logger::Error<<"Unable to read 'keep' value: "<<e.what()<<endl;
 902       retval = false;
 903     }
 904   } else {
 905     config["keep"] = 20;
 906   }
 907
 908   if (config["axfr-timeout"]) {
 909     try {
 910       config["axfr-timeout"].as<uint16_t>();
 911     } catch (const runtime_error &e) {
 912       g_log<<Logger::Error<<"Unable to read 'axfr-timeout' value: "<<e.what()<<endl;
 913     }
 914   } else {
 915     config["axfr-timeout"] = 20;
 916   }
 917
 918   if (config["tcp-in-threads"]) {
 919     try {
 920       config["tcp-in-threads"].as<uint16_t>();
 921     } catch (const runtime_error &e) {
 922       g_log<<Logger::Error<<"Unable to read 'tcp-in-threads' value: "<<e.what()<<endl;
 923     }
 924   } else {
 925     config["tcp-in-threads"] = 10;
 926   }
 927
 928   if (config["listen"]) {
 929     try {
 930       config["listen"].as<vector<ComboAddress>>();
 931     } catch (const runtime_error &e) {
 932       g_log<<Logger::Error<<"Unable to read 'listen' value: "<<e.what()<<endl;
 933       retval = false;
 934     }
 935   } else {
 936     config["listen"].push_back("127.0.0.1:53");
 937     config["listen"].push_back("[::1]:53");
 938   }
 939
 940   if (config["acl"]) {
 941     try {
 942       config["acl"].as<vector<string>>();
 943     } catch (const runtime_error &e) {
 944       g_log<<Logger::Error<<"Unable to read 'acl' value: "<<e.what()<<endl;
 945       retval = false;
 946     }
 947   } else {
 948     config["acl"].push_back("127.0.0.0/8");
 949     config["acl"].push_back("::1/128");
 950   }
 951
 952   if (config["work-dir"]) {
 953     try {
 954       config["work-dir"].as<string>();
 955     } catch(const runtime_error &e) {
 956       g_log<<Logger::Error<<"Unable to read 'work-dir' value: "<<e.what()<<endl;
 957       retval = false;
 958     }
 959   } else {
 960     char tmp[512];
 961     config["work-dir"] = getcwd(tmp, sizeof(tmp)) ? string(tmp) : "";;
 962   }
 963
 964   if (config["uid"]) {
 965     try {
 966       config["uid"].as<string>();
 967     } catch(const runtime_error &e) {
 968       g_log<<Logger::Error<<"Unable to read 'uid' value: "<<e.what()<<endl;
 969       retval = false;
 970     }
 971   }
 972
 973   if (config["gid"]) {
 974     try {
 975       config["gid"].as<string>();
 976     } catch(const runtime_error &e) {
 977       g_log<<Logger::Error<<"Unable to read 'gid' value: "<<e.what()<<endl;
 978       retval = false;
 979     }
 980   }
 981
 982   if (config["domains"]) {
 983     if (config["domains"].size() == 0) {
 984       g_log<<Logger::Error<<"No domains configured"<<endl;
 985       retval = false;
 986     }
 987     for (auto const &domain : config["domains"]) {
 988       try {
 989         if (!domain["domain"]) {
 990           g_log<<Logger::Error<<"An entry in 'domains' is missing a 'domain' key!"<<endl;
 991           retval = false;
 992           continue;
 993         }
 994         domain["domain"].as<DNSName>();
 995       } catch (const runtime_error &e) {
 996         g_log<<Logger::Error<<"Unable to read domain '"<<domain["domain"].as<string>()<<"': "<<e.what()<<endl;
 997       }
 998       try {
 999         if (!domain["master"]) {
1000           g_log<<Logger::Error<<"Domain '"<<domain["domain"].as<string>()<<"' has no master configured!"<<endl;
1001           retval = false;
1002           continue;
1003         }
1004         domain["master"].as<ComboAddress>();
1005       } catch (const runtime_error &e) {
1006         g_log<<Logger::Error<<"Unable to read domain '"<<domain["domain"].as<string>()<<"' master address: "<<e.what()<<endl;
1007         retval = false;
1008       }
1009     }
1010   } else {
1011     g_log<<Logger::Error<<"No domains configured"<<endl;
1012     retval = false;
1013   }
1014
1015   if (config["compress"]) {
1016     try {
1017       config["compress"].as<bool>();
1018     }
1019     catch (const runtime_error &e) {
1020       g_log<<Logger::Error<<"Unable to read 'compress' value: "<<e.what()<<endl;
1021       retval = false;
1022     }
1023   }
1024   else {
1025     config["compress"] = false;
1026   }
1027
1028   return retval;
1029 }
1030
1031 int main(int argc, char** argv) {
1032   g_log.setLoglevel(Logger::Notice);
1033   g_log.toConsole(Logger::Notice);
1034   g_log.setPrefixed(true);
1035   g_log.disableSyslog(true);
1036   g_log.setTimestamps(false);
1037   po::variables_map g_vm;
1038   try {
1039     po::options_description desc("IXFR distribution tool");
1040     desc.add_options()
1041       ("help", "produce help message")
1042       ("version", "Display the version of ixfrdist")
1043       ("verbose", "Be verbose")
1044       ("debug", "Be even more verbose")
1045       ("config", po::value<string>()->default_value(SYSCONFDIR + string("/ixfrdist.yml")), "Configuration file to use")
1046       ;
1047
1048     po::store(po::command_line_parser(argc, argv).options(desc).run(), g_vm);
1049     po::notify(g_vm);
1050
1051     if (g_vm.count("help") > 0) {
1052       usage(desc);
1053       return EXIT_SUCCESS;
1054     }
1055
1056     if (g_vm.count("version") > 0) {
1057       cout<<"ixfrdist "<<VERSION<<endl;
1058       return EXIT_SUCCESS;
1059     }
1060   } catch (po::error &e) {
1061     g_log<<Logger::Error<<e.what()<<". See `ixfrdist --help` for valid options"<<endl;
1062     return(EXIT_FAILURE);
1063   }
1064
1065   bool had_error = false;
1066
1067   if (g_vm.count("verbose")) {
1068     g_log.setLoglevel(Logger::Info);
1069     g_log.toConsole(Logger::Info);
1070   }
1071
1072   if (g_vm.count("debug") > 0) {
1073     g_log.setLoglevel(Logger::Debug);
1074     g_log.toConsole(Logger::Debug);
1075   }
1076
1077   g_log<<Logger::Notice<<"IXFR distributor version "<<VERSION<<" starting up!"<<endl;
1078
1079   YAML::Node config;
1080   if (!parseAndCheckConfig(g_vm["config"].as<string>(), config)) {
1081     // parseAndCheckConfig already logged whatever was wrong
1082     return EXIT_FAILURE;
1083   }
1084
1085   /*  From hereon out, we known that all the values in config are valid. */
1086
1087   for (auto const &domain : config["domains"]) {
1088     set<ComboAddress> s;
1089     s.insert(domain["master"].as<ComboAddress>());
1090     g_domainConfigs[domain["domain"].as<DNSName>()].masters = s;
1091   }
1092
1093   for (const auto &addr : config["acl"].as<vector<string>>()) {
1094     try {
1095       g_acl.addMask(addr);
1096     } catch (const NetmaskException &e) {
1097       g_log<<Logger::Error<<e.reason<<endl;
1098       had_error = true;
1099     }
1100   }
1101   g_log<<Logger::Notice<<"ACL set to "<<g_acl.toString()<<"."<<endl;
1102
1103   if (config["compress"]) {
1104     g_compress = config["compress"].as<bool>();
1105     if (g_compress) {
1106       g_log<<Logger::Notice<<"Record compression is enabled."<<endl;
1107     }
1108   }
1109
1110   FDMultiplexer* fdm = FDMultiplexer::getMultiplexerSilent();
1111   if (fdm == nullptr) {
1112     g_log<<Logger::Error<<"Could not enable a multiplexer for the listen sockets!"<<endl;
1113     return EXIT_FAILURE;
1114   }
1115
1116   set<int> allSockets;
1117   for (const auto& addr : config["listen"].as<vector<ComboAddress>>()) {
1118     for (const auto& stype : {SOCK_DGRAM, SOCK_STREAM}) {
1119       try {
1120         int s = SSocket(addr.sin4.sin_family, stype, 0);
1121         setNonBlocking(s);
1122         setReuseAddr(s);
1123         SBind(s, addr);
1124         if (stype == SOCK_STREAM) {
1125           SListen(s, 30); // TODO make this configurable
1126         }
1127         fdm->addReadFD(s, stype == SOCK_DGRAM ? handleUDPRequest : handleTCPRequest);
1128         allSockets.insert(s);
1129       } catch(runtime_error &e) {
1130         g_log<<Logger::Error<<e.what()<<endl;
1131         had_error = true;
1132         continue;
1133       }
1134     }
1135   }
1136
1137   int newgid = 0;
1138
1139   if (config["gid"]) {
1140     string gid = config["gid"].as<string>();
1141     if (!(newgid = atoi(gid.c_str()))) {
1142       struct group *gr = getgrnam(gid.c_str());
1143       if (gr == nullptr) {
1144         g_log<<Logger::Error<<"Can not determine group-id for gid "<<gid<<endl;
1145         had_error = true;
1146       } else {
1147         newgid = gr->gr_gid;
1148       }
1149     }
1150     g_log<<Logger::Notice<<"Dropping effective group-id to "<<newgid<<endl;
1151     if (setgid(newgid) < 0) {
1152       g_log<<Logger::Error<<"Could not set group id to "<<newgid<<": "<<stringerror()<<endl;
1153       had_error = true;
1154     }
1155   }
1156
1157   int newuid = 0;
1158
1159   if (config["uid"]) {
1160     string uid = config["uid"].as<string>();
1161     if (!(newuid = atoi(uid.c_str()))) {
1162       struct passwd *pw = getpwnam(uid.c_str());
1163       if (pw == nullptr) {
1164         g_log<<Logger::Error<<"Can not determine user-id for uid "<<uid<<endl;
1165         had_error = true;
1166       } else {
1167         newuid = pw->pw_uid;
1168       }
1169     }
1170
1171     struct passwd *pw = getpwuid(newuid);
1172     if (pw == nullptr) {
1173       if (setgroups(0, nullptr) < 0) {
1174         g_log<<Logger::Error<<"Unable to drop supplementary gids: "<<stringerror()<<endl;
1175         had_error = true;
1176       }
1177     } else {
1178       if (initgroups(pw->pw_name, newgid) < 0) {
1179         g_log<<Logger::Error<<"Unable to set supplementary groups: "<<stringerror()<<endl;
1180         had_error = true;
1181       }
1182     }
1183
1184     g_log<<Logger::Notice<<"Dropping effective user-id to "<<newuid<<endl;
1185     if (setuid(newuid) < 0) {
1186       g_log<<Logger::Error<<"Could not set user id to "<<newuid<<": "<<stringerror()<<endl;
1187       had_error = true;
1188     }
1189   }
1190
1191   if (had_error) {
1192     // We have already sent the errors to stderr, just die
1193     return EXIT_FAILURE;
1194   }
1195
1196   // It all starts here
1197   signal(SIGTERM, handleSignal);
1198   signal(SIGINT, handleSignal);
1199   signal(SIGPIPE, SIG_IGN);
1200
1201   // Init the things we need
1202   reportAllTypes();
1203
1204   dns_random_init();
1205
1206   std::thread ut(updateThread,
1207       config["work-dir"].as<string>(),
1208       config["keep"].as<uint16_t>(),
1209       config["axfr-timeout"].as<uint16_t>());
1210
1211   vector<std::thread> tcpHandlers;
1212   tcpHandlers.reserve(config["tcp-in-threads"].as<uint16_t>());
1213   for (size_t i = 0; i < tcpHandlers.capacity(); ++i) {
1214     tcpHandlers.push_back(std::thread(tcpWorker, i));
1215   }
1216
1217   struct timeval now;
1218   for(;;) {
1219     gettimeofday(&now, 0);
1220     fdm->run(&now);
1221     if (g_exiting) {
1222       g_log<<Logger::Debug<<"Closing listening sockets"<<endl;
1223       for (const int& fd : allSockets) {
1224         try {
1225           closesocket(fd);
1226         } catch(PDNSException &e) {
1227           g_log<<Logger::Error<<e.reason<<endl;
1228         }
1229       }
1230       break;
1231     }
1232   }
1233   g_log<<Logger::Debug<<"Waiting for al threads to stop"<<endl;
1234   g_tcpHandlerCV.notify_all();
1235   ut.join();
1236   for (auto &t : tcpHandlers) {
1237     t.join();
1238   }
1239   g_log<<Logger::Notice<<"IXFR distributor stopped"<<endl;
1240   return EXIT_SUCCESS;
1241 }