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 "threadname.hh"
  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, const uint16_t& soaRetry) {
 238   setThreadName("ixfrdist/update");
 239   std::map<DNSName, time_t> lastCheck;
 240
 241   // Initialize the serials we have
 242   for (const auto &domainConfig : g_domainConfigs) {
 243     DNSName domain = domainConfig.first;
 244     lastCheck[domain] = 0;
 245     string dir = workdir + "/" + domain.toString();
 246     try {
 247       g_log<<Logger::Info<<"Trying to initially load domain "<<domain<<" from disk"<<endl;
 248       auto serial = getSerialsFromDir(dir);
 249       shared_ptr<SOARecordContent> soa;
 250       {
 251         string fname = workdir + "/" + domain.toString() + "/" + std::to_string(serial);
 252         loadSOAFromDisk(domain, fname, soa);
 253         records_t records;
 254         if (soa != nullptr) {
 255           loadZoneFromDisk(records, fname, domain);
 256         }
 257         auto zoneInfo = std::make_shared<ixfrinfo_t>();
 258         zoneInfo->latestAXFR = std::move(records);
 259         zoneInfo->soa = soa;
 260         updateCurrentZoneInfo(domain, zoneInfo);
 261       }
 262       if (soa != nullptr) {
 263         g_log<<Logger::Notice<<"Loaded zone "<<domain<<" with serial "<<soa->d_st.serial<<endl;
 264         // Initial cleanup
 265         cleanUpDomain(domain, keep, workdir);
 266       }
 267     } catch (runtime_error &e) {
 268       // Most likely, the directory does not exist.
 269       g_log<<Logger::Info<<e.what()<<", attempting to create"<<endl;
 270       // Attempt to create it, if _that_ fails, there is no hope
 271       if (mkdir(dir.c_str(), 0777) == -1 && errno != EEXIST) {
 272         g_log<<Logger::Error<<"Could not create '"<<dir<<"': "<<strerror(errno)<<endl;
 273         exit(EXIT_FAILURE);
 274       }
 275     }
 276   }
 277
 278   g_log<<Logger::Notice<<"Update Thread started"<<endl;
 279
 280   while (true) {
 281     if (g_exiting) {
 282       g_log<<Logger::Notice<<"UpdateThread stopped"<<endl;
 283       break;
 284     }
 285     time_t now = time(nullptr);
 286     for (const auto &domainConfig : g_domainConfigs) {
 287
 288       if (g_exiting) {
 289         break;
 290       }
 291
 292       DNSName domain = domainConfig.first;
 293       shared_ptr<SOARecordContent> current_soa;
 294       const auto& zoneInfo = getCurrentZoneInfo(domain);
 295       if (zoneInfo != nullptr) {
 296         current_soa = zoneInfo->soa;
 297       }
 298
 299       auto& zoneLastCheck = lastCheck[domain];
 300       if ((current_soa != nullptr && now - zoneLastCheck < current_soa->d_st.refresh) || // Only check if we have waited `refresh` seconds
 301           (current_soa == nullptr && now - zoneLastCheck < soaRetry))  {                       // Or if we could not get an update at all still, every 30 seconds
 302         continue;
 303       }
 304
 305       // TODO Keep track of 'down' masters
 306       set<ComboAddress>::const_iterator it(domainConfig.second.masters.begin());
 307       std::advance(it, random() % domainConfig.second.masters.size());
 308       ComboAddress master = *it;
 309
 310       string dir = workdir + "/" + domain.toString();
 311       g_log<<Logger::Info<<"Attempting to retrieve SOA Serial update for '"<<domain<<"' from '"<<master.toStringWithPort()<<"'"<<endl;
 312       shared_ptr<SOARecordContent> sr;
 313       try {
 314         zoneLastCheck = now;
 315         auto newSerial = getSerialFromMaster(master, domain, sr); // TODO TSIG
 316         if(current_soa != nullptr) {
 317           g_log<<Logger::Info<<"Got SOA Serial for "<<domain<<" from "<<master.toStringWithPort()<<": "<< newSerial<<", had Serial: "<<current_soa->d_st.serial;
 318           if (newSerial == current_soa->d_st.serial) {
 319             g_log<<Logger::Info<<", not updating."<<endl;
 320             continue;
 321           }
 322           g_log<<Logger::Info<<", will update."<<endl;
 323         }
 324       } catch (runtime_error &e) {
 325         g_log<<Logger::Warning<<"Unable to get SOA serial update for '"<<domain<<"' from master "<<master.toStringWithPort()<<": "<<e.what()<<endl;
 326         continue;
 327       }
 328       // Now get the full zone!
 329       g_log<<Logger::Info<<"Attempting to receive full zonedata for '"<<domain<<"'"<<endl;
 330       ComboAddress local = master.isIPv4() ? ComboAddress("0.0.0.0") : ComboAddress("::");
 331       TSIGTriplet tt;
 332
 333       // The *new* SOA
 334       shared_ptr<SOARecordContent> soa;
 335       records_t records;
 336       try {
 337         AXFRRetriever axfr(master, domain, tt, &local);
 338         unsigned int nrecords=0;
 339         Resolver::res_t nop;
 340         vector<DNSRecord> chunk;
 341         time_t t_start = time(nullptr);
 342         time_t axfr_now = time(nullptr);
 343         while(axfr.getChunk(nop, &chunk, (axfr_now - t_start + axfrTimeout))) {
 344           for(auto& dr : chunk) {
 345             if(dr.d_type == QType::TSIG)
 346               continue;
 347             dr.d_name.makeUsRelative(domain);
 348             records.insert(dr);
 349             nrecords++;
 350             if (dr.d_type == QType::SOA) {
 351               soa = getRR<SOARecordContent>(dr);
 352             }
 353           }
 354           axfr_now = time(nullptr);
 355           if (axfr_now - t_start > axfrTimeout) {
 356             throw PDNSException("Total AXFR time exceeded!");
 357           }
 358         }
 359         if (soa == nullptr) {
 360           g_log<<Logger::Warning<<"No SOA was found in the AXFR of "<<domain<<endl;
 361           continue;
 362         }
 363         g_log<<Logger::Notice<<"Retrieved all zone data for "<<domain<<". Received "<<nrecords<<" records."<<endl;
 364       } catch (PDNSException &e) {
 365         g_log<<Logger::Warning<<"Could not retrieve AXFR for '"<<domain<<"': "<<e.reason<<endl;
 366         continue;
 367       } catch (runtime_error &e) {
 368         g_log<<Logger::Warning<<"Could not retrieve AXFR for zone '"<<domain<<"': "<<e.what()<<endl;
 369         continue;
 370       }
 371
 372       try {
 373
 374         writeZoneToDisk(records, domain, dir);
 375         g_log<<Logger::Notice<<"Wrote zonedata for "<<domain<<" with serial "<<soa->d_st.serial<<" to "<<dir<<endl;
 376
 377         const auto oldZoneInfo = getCurrentZoneInfo(domain);
 378         auto zoneInfo = std::make_shared<ixfrinfo_t>();
 379
 380         if (oldZoneInfo && !oldZoneInfo->latestAXFR.empty()) {
 381           auto diff = std::make_shared<ixfrdiff_t>();
 382           zoneInfo->ixfrDiffs = oldZoneInfo->ixfrDiffs;
 383           g_log<<Logger::Debug<<"Calculating diff for "<<domain<<endl;
 384           makeIXFRDiff(oldZoneInfo->latestAXFR, records, diff, oldZoneInfo->soa, soa);
 385           g_log<<Logger::Debug<<"Calculated diff for "<<domain<<", we had "<<diff->removals.size()<<" removals and "<<diff->additions.size()<<" additions"<<endl;
 386           zoneInfo->ixfrDiffs.push_back(std::move(diff));
 387         }
 388
 389         // Clean up the diffs
 390         while (zoneInfo->ixfrDiffs.size() > keep) {
 391           zoneInfo->ixfrDiffs.erase(zoneInfo->ixfrDiffs.begin());
 392         }
 393
 394         g_log<<Logger::Debug<<"Zone "<<domain<<" previously contained "<<(oldZoneInfo ? oldZoneInfo->latestAXFR.size() : 0)<<" entries, "<<records.size()<<" now"<<endl;
 395         zoneInfo->latestAXFR = std::move(records);
 396         zoneInfo->soa = soa;
 397         updateCurrentZoneInfo(domain, zoneInfo);
 398       } catch (PDNSException &e) {
 399         g_log<<Logger::Warning<<"Could not save zone '"<<domain<<"' to disk: "<<e.reason<<endl;
 400       } catch (runtime_error &e) {
 401         g_log<<Logger::Warning<<"Could not save zone '"<<domain<<"' to disk: "<<e.what()<<endl;
 402       }
 403
 404       // Now clean up the directory
 405       cleanUpDomain(domain, keep, workdir);
 406     } /* for (const auto &domain : domains) */
 407     sleep(1);
 408   } /* while (true) */
 409 } /* updateThread */
 410
 411 static bool checkQuery(const MOADNSParser& mdp, const ComboAddress& saddr, const bool udp = true, const string& logPrefix="") {
 412   vector<string> info_msg;
 413
 414   g_log<<Logger::Debug<<logPrefix<<"Had "<<mdp.d_qname<<"|"<<QType(mdp.d_qtype).getName()<<" query from "<<saddr.toStringWithPort()<<endl;
 415
 416   if (udp && mdp.d_qtype != QType::SOA && mdp.d_qtype != QType::IXFR) {
 417     info_msg.push_back("QType is unsupported (" + QType(mdp.d_qtype).getName() + " is not in {SOA,IXFR})");
 418   }
 419
 420   if (!udp && mdp.d_qtype != QType::SOA && mdp.d_qtype != QType::IXFR && mdp.d_qtype != QType::AXFR) {
 421     info_msg.push_back("QType is unsupported (" + QType(mdp.d_qtype).getName() + " is not in {SOA,IXFR,AXFR})");
 422   }
 423
 424   {
 425     if (g_domainConfigs.find(mdp.d_qname) == g_domainConfigs.end()) {
 426       info_msg.push_back("Domain name '" + mdp.d_qname.toLogString() + "' is not configured for distribution");
 427     }
 428
 429     const auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 430     if (zoneInfo == nullptr) {
 431       info_msg.push_back("Domain has not been transferred yet");
 432     }
 433   }
 434
 435   if (!info_msg.empty()) {
 436     g_log<<Logger::Warning<<logPrefix<<"Ignoring "<<mdp.d_qname<<"|"<<QType(mdp.d_qtype).getName()<<" query from "<<saddr.toStringWithPort();
 437     g_log<<Logger::Warning<<": ";
 438     bool first = true;
 439     for (const auto& s : info_msg) {
 440       if (!first) {
 441         g_log<<Logger::Warning<<", ";
 442         first = false;
 443       }
 444       g_log<<Logger::Warning<<s;
 445     }
 446     g_log<<Logger::Warning<<endl;
 447     return false;
 448   }
 449
 450   return true;
 451 }
 452
 453 /*
 454  * Returns a vector<uint8_t> that represents the full response to a SOA
 455  * query. QNAME is read from mdp.
 456  */
 457 static bool makeSOAPacket(const MOADNSParser& mdp, vector<uint8_t>& packet) {
 458
 459   auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 460   if (zoneInfo == nullptr) {
 461     return false;
 462   }
 463
 464   DNSPacketWriter pw(packet, mdp.d_qname, mdp.d_qtype);
 465   pw.getHeader()->id = mdp.d_header.id;
 466   pw.getHeader()->rd = mdp.d_header.rd;
 467   pw.getHeader()->qr = 1;
 468
 469   pw.startRecord(mdp.d_qname, QType::SOA);
 470   zoneInfo->soa->toPacket(pw);
 471   pw.commit();
 472
 473   return true;
 474 }
 475
 476 static vector<uint8_t> getSOAPacket(const MOADNSParser& mdp, const shared_ptr<SOARecordContent>& soa) {
 477   vector<uint8_t> packet;
 478   DNSPacketWriter pw(packet, mdp.d_qname, mdp.d_qtype);
 479   pw.getHeader()->id = mdp.d_header.id;
 480   pw.getHeader()->rd = mdp.d_header.rd;
 481   pw.getHeader()->qr = 1;
 482
 483   // Add the first SOA
 484   pw.startRecord(mdp.d_qname, QType::SOA);
 485   soa->toPacket(pw);
 486   pw.commit();
 487   return packet;
 488 }
 489
 490 static bool sendPacketOverTCP(int fd, const std::vector<uint8_t>& packet)
 491 {
 492   char sendBuf[2];
 493   sendBuf[0]=packet.size()/256;
 494   sendBuf[1]=packet.size()%256;
 495
 496   ssize_t send = writen2(fd, sendBuf, 2);
 497   send += writen2(fd, &packet[0], packet.size());
 498   return true;
 499 }
 500
 501 static bool addRecordToWriter(DNSPacketWriter& pw, const DNSName& zoneName, const DNSRecord& record, bool compress)
 502 {
 503   pw.startRecord(record.d_name + zoneName, record.d_type, record.d_ttl, QClass::IN, DNSResourceRecord::ANSWER, compress);
 504   record.d_content->toPacket(pw);
 505   if (pw.size() > 65535) {
 506     pw.rollback();
 507     return false;
 508   }
 509   return true;
 510 }
 511
 512 template <typename T> static bool sendRecordsOverTCP(int fd, const MOADNSParser& mdp, const T& records)
 513 {
 514   vector<uint8_t> packet;
 515
 516   for (auto it = records.cbegin(); it != records.cend();) {
 517     bool recordsAdded = false;
 518     packet.clear();
 519     DNSPacketWriter pw(packet, mdp.d_qname, mdp.d_qtype);
 520     pw.getHeader()->id = mdp.d_header.id;
 521     pw.getHeader()->rd = mdp.d_header.rd;
 522     pw.getHeader()->qr = 1;
 523
 524     while (it != records.cend()) {
 525       if (it->d_type == QType::SOA) {
 526         it++;
 527         continue;
 528       }
 529
 530       if (addRecordToWriter(pw, mdp.d_qname, *it, g_compress)) {
 531         recordsAdded = true;
 532         it++;
 533       }
 534       else {
 535         if (recordsAdded) {
 536           pw.commit();
 537           sendPacketOverTCP(fd, packet);
 538         }
 539         if (it == records.cbegin()) {
 540           /* something is wrong */
 541           return false;
 542         }
 543
 544         break;
 545       }
 546     }
 547
 548     if (it == records.cend() && recordsAdded) {
 549       pw.commit();
 550       sendPacketOverTCP(fd, packet);
 551     }
 552   }
 553
 554   return true;
 555 }
 556
 557
 558 static bool handleAXFR(int fd, const MOADNSParser& mdp) {
 559   /* we get a shared pointer of the zone info that we can't modify, ever.
 560      A newer one may arise in the meantime, but this one will stay valid
 561      until we release it.
 562   */
 563   auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 564   if (zoneInfo == nullptr) {
 565     return false;
 566   }
 567
 568   shared_ptr<SOARecordContent> soa = zoneInfo->soa;
 569   const records_t& records = zoneInfo->latestAXFR;
 570
 571   // Initial SOA
 572   const auto soaPacket = getSOAPacket(mdp, soa);
 573   if (!sendPacketOverTCP(fd, soaPacket)) {
 574     return false;
 575   }
 576
 577   if (!sendRecordsOverTCP(fd, mdp, records)) {
 578     return false;
 579   }
 580
 581   // Final SOA
 582   if (!sendPacketOverTCP(fd, soaPacket)) {
 583     return false;
 584   }
 585
 586   return true;
 587 }
 588
 589 /* Produces an IXFR if one can be made according to the rules in RFC 1995 and
 590  * creates a SOA or AXFR packet when required by the RFC.
 591  */
 592 static bool handleIXFR(int fd, const ComboAddress& destination, const MOADNSParser& mdp, const shared_ptr<SOARecordContent>& clientSOA) {
 593   vector<std::shared_ptr<ixfrdiff_t>> toSend;
 594
 595   /* we get a shared pointer of the zone info that we can't modify, ever.
 596      A newer one may arise in the meantime, but this one will stay valid
 597      until we release it.
 598   */
 599   auto zoneInfo = getCurrentZoneInfo(mdp.d_qname);
 600   if (zoneInfo == nullptr) {
 601     return false;
 602   }
 603
 604   uint32_t ourLatestSerial = zoneInfo->soa->d_st.serial;
 605
 606   if (rfc1982LessThan(ourLatestSerial, clientSOA->d_st.serial) || ourLatestSerial == clientSOA->d_st.serial) {
 607     /* RFC 1995 Section 2
 608      *    If an IXFR query with the same or newer version number than that of
 609      *    the server is received, it is replied to with a single SOA record of
 610      *    the server's current version, just as in AXFR.
 611      */
 612     vector<uint8_t> packet;
 613     bool ret = makeSOAPacket(mdp, packet);
 614     if (ret) {
 615       sendPacketOverTCP(fd, packet);
 616     }
 617     return ret;
 618   }
 619
 620   // as we use push_back in the updater, we know the vector is sorted as oldest first
 621   bool shouldAdd = false;
 622   // Get all relevant IXFR differences
 623   for (const auto& diff : zoneInfo->ixfrDiffs) {
 624     if (shouldAdd) {
 625       toSend.push_back(diff);
 626       continue;
 627     }
 628     if (diff->oldSOA->d_st.serial == clientSOA->d_st.serial) {
 629       toSend.push_back(diff);
 630       // Add all consecutive diffs
 631       shouldAdd = true;
 632     }
 633   }
 634
 635   if (toSend.empty()) {
 636     g_log<<Logger::Warning<<"No IXFR available from serial "<<clientSOA->d_st.serial<<" for zone "<<mdp.d_qname<<", attempting to send AXFR"<<endl;
 637     return handleAXFR(fd, mdp);
 638   }
 639
 640   std::vector<std::vector<uint8_t>> packets;
 641   for (const auto& diff : toSend) {
 642     /* An IXFR packet's ANSWER section looks as follows:
 643      * SOA new_serial
 644      * SOA old_serial
 645      * ... removed records ...
 646      * SOA new_serial
 647      * ... added records ...
 648      * SOA new_serial
 649      */
 650
 651     const auto newSOAPacket = getSOAPacket(mdp, diff->newSOA);
 652     const auto oldSOAPacket = getSOAPacket(mdp, diff->oldSOA);
 653
 654     if (!sendPacketOverTCP(fd, newSOAPacket)) {
 655       return false;
 656     }
 657
 658     if (!sendPacketOverTCP(fd, oldSOAPacket)) {
 659       return false;
 660     }
 661
 662     if (!sendRecordsOverTCP(fd, mdp, diff->removals)) {
 663       return false;
 664     }
 665
 666     if (!sendPacketOverTCP(fd, newSOAPacket)) {
 667       return false;
 668     }
 669
 670     if (!sendRecordsOverTCP(fd, mdp, diff->additions)) {
 671       return false;
 672     }
 673
 674     if (!sendPacketOverTCP(fd, newSOAPacket)) {
 675       return false;
 676     }
 677   }
 678
 679   return true;
 680 }
 681
 682 static bool allowedByACL(const ComboAddress& addr) {
 683   return g_acl.match(addr);
 684 }
 685
 686 static void handleUDPRequest(int fd, boost::any&) {
 687   // TODO make the buffer-size configurable
 688   char buf[4096];
 689   ComboAddress saddr;
 690   socklen_t fromlen = sizeof(saddr);
 691   int res = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr*) &saddr, &fromlen);
 692
 693   if (res == 0) {
 694     g_log<<Logger::Warning<<"Got an empty message from "<<saddr.toStringWithPort()<<endl;
 695     return;
 696   }
 697
 698   if(res < 0) {
 699     auto savedErrno = errno;
 700     g_log<<Logger::Warning<<"Could not read message from "<<saddr.toStringWithPort()<<": "<<strerror(savedErrno)<<endl;
 701     return;
 702   }
 703
 704   if (saddr == ComboAddress("0.0.0.0", 0)) {
 705     g_log<<Logger::Warning<<"Could not determine source of message"<<endl;
 706     return;
 707   }
 708
 709   if (!allowedByACL(saddr)) {
 710     g_log<<Logger::Warning<<"UDP query from "<<saddr.toString()<<" is not allowed, dropping"<<endl;
 711     return;
 712   }
 713
 714   MOADNSParser mdp(true, string(buf, res));
 715   if (!checkQuery(mdp, saddr)) {
 716     return;
 717   }
 718
 719   /* RFC 1995 Section 2
 720    *    Transport of a query may be by either UDP or TCP.  If an IXFR query
 721    *    is via UDP, the IXFR server may attempt to reply using UDP if the
 722    *    entire response can be contained in a single DNS packet.  If the UDP
 723    *    reply does not fit, the query is responded to with a single SOA
 724    *    record of the server's current version to inform the client that a
 725    *    TCP query should be initiated.
 726    *
 727    * Let's not complicate this with IXFR over UDP (and looking if we need to truncate etc).
 728    * Just send the current SOA and let the client try over TCP
 729    */
 730   vector<uint8_t> packet;
 731   makeSOAPacket(mdp, packet);
 732   if(sendto(fd, &packet[0], packet.size(), 0, (struct sockaddr*) &saddr, fromlen) < 0) {
 733     auto savedErrno = errno;
 734     g_log<<Logger::Warning<<"Could not send reply for "<<mdp.d_qname<<"|"<<QType(mdp.d_qtype).getName()<<" to "<<saddr.toStringWithPort()<<": "<<strerror(savedErrno)<<endl;
 735   }
 736   return;
 737 }
 738
 739 static void handleTCPRequest(int fd, boost::any&) {
 740   ComboAddress saddr;
 741   int cfd = 0;
 742
 743   try {
 744     cfd = SAccept(fd, saddr);
 745     setBlocking(cfd);
 746   } catch(runtime_error &e) {
 747     g_log<<Logger::Error<<e.what()<<endl;
 748     return;
 749   }
 750
 751   if (saddr == ComboAddress("0.0.0.0", 0)) {
 752     g_log<<Logger::Warning<<"Could not determine source of message"<<endl;
 753     close(cfd);
 754     return;
 755   }
 756
 757   if (!allowedByACL(saddr)) {
 758     g_log<<Logger::Warning<<"TCP query from "<<saddr.toString()<<" is not allowed, dropping"<<endl;
 759     close(cfd);
 760     return;
 761   }
 762
 763   {
 764     std::lock_guard<std::mutex> lg(g_tcpRequestFDsMutex);
 765     g_tcpRequestFDs.push({cfd, saddr});
 766   }
 767   g_tcpHandlerCV.notify_one();
 768 }
 769
 770 /* Thread to handle TCP traffic
 771  */
 772 static void tcpWorker(int tid) {
 773   setThreadName("ixfrdist/tcpWor");
 774   string prefix = "TCP Worker " + std::to_string(tid) + ": ";
 775
 776   while(true) {
 777     g_log<<Logger::Debug<<prefix<<"ready for a new request!"<<endl;
 778     std::unique_lock<std::mutex> lk(g_tcpRequestFDsMutex);
 779     g_tcpHandlerCV.wait(lk, []{return g_tcpRequestFDs.size() || g_exiting ;});
 780     if (g_exiting) {
 781       g_log<<Logger::Debug<<prefix<<"Stopping thread"<<endl;
 782       break;
 783     }
 784     g_log<<Logger::Debug<<prefix<<"Going to handle a query"<<endl;
 785     auto request = g_tcpRequestFDs.front();
 786     g_tcpRequestFDs.pop();
 787     lk.unlock();
 788
 789     int cfd = request.first;
 790     ComboAddress saddr = request.second;
 791
 792     char buf[4096];
 793     ssize_t res;
 794     try {
 795       uint16_t toRead;
 796       readn2(cfd, &toRead, sizeof(toRead));
 797       toRead = std::min(ntohs(toRead), static_cast<uint16_t>(sizeof(buf)));
 798       res = readn2WithTimeout(cfd, &buf, toRead, 2);
 799       g_log<<Logger::Debug<<prefix<<"Had message of "<<std::to_string(toRead)<<" bytes from "<<saddr.toStringWithPort()<<endl;
 800     } catch (runtime_error &e) {
 801       g_log<<Logger::Warning<<prefix<<"Could not read message from "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
 802       close(cfd);
 803       continue;
 804     }
 805
 806     try {
 807       MOADNSParser mdp(true, string(buf, res));
 808
 809       if (!checkQuery(mdp, saddr, false, prefix)) {
 810         close(cfd);
 811         continue;
 812       }
 813
 814       if (mdp.d_qtype == QType::SOA) {
 815         vector<uint8_t> packet;
 816         bool ret = makeSOAPacket(mdp, packet);
 817         if (!ret) {
 818           close(cfd);
 819           continue;
 820         }
 821         sendPacketOverTCP(cfd, packet);
 822       }
 823       else if (mdp.d_qtype == QType::AXFR) {
 824         if (!handleAXFR(cfd, mdp)) {
 825           close(cfd);
 826           continue;
 827         }
 828       }
 829       else if (mdp.d_qtype == QType::IXFR) {
 830         /* RFC 1995 section 3:
 831          *  The IXFR query packet format is the same as that of a normal DNS
 832          *  query, but with the query type being IXFR and the authority section
 833          *  containing the SOA record of client's version of the zone.
 834          */
 835         shared_ptr<SOARecordContent> clientSOA;
 836         for (auto &answer : mdp.d_answers) {
 837           // from dnsparser.hh:
 838           // typedef vector<pair<DNSRecord, uint16_t > > answers_t;
 839           if (answer.first.d_type == QType::SOA && answer.first.d_place == DNSResourceRecord::AUTHORITY) {
 840             clientSOA = getRR<SOARecordContent>(answer.first);
 841             if (clientSOA != nullptr) {
 842               break;
 843             }
 844           }
 845         } /* for (auto const &answer : mdp.d_answers) */
 846
 847         if (clientSOA == nullptr) {
 848           g_log<<Logger::Warning<<prefix<<"IXFR request packet did not contain a SOA record in the AUTHORITY section"<<endl;
 849           close(cfd);
 850           continue;
 851         }
 852
 853         if (!handleIXFR(cfd, saddr, mdp, clientSOA)) {
 854           close(cfd);
 855           continue;
 856         }
 857       } /* if (mdp.d_qtype == QType::IXFR) */
 858
 859       shutdown(cfd, 2);
 860     } catch (MOADNSException &e) {
 861       g_log<<Logger::Warning<<prefix<<"Could not parse DNS packet from "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
 862     } catch (runtime_error &e) {
 863       g_log<<Logger::Warning<<prefix<<"Could not write reply to "<<saddr.toStringWithPort()<<": "<<e.what()<<endl;
 864     }
 865     // bye!
 866     close(cfd);
 867
 868     if (g_exiting) {
 869       break;
 870     }
 871   }
 872 }
 873
 874 /* Parses the configuration file in configpath into config, adding defaults for
 875  * missing parameters (if applicable), returning true if the config file was
 876  * good, false otherwise. Will log all issues with the config
 877  */
 878 static bool parseAndCheckConfig(const string& configpath, YAML::Node& config) {
 879   g_log<<Logger::Info<<"Loading configuration file from "<<configpath<<endl;
 880   try {
 881     config = YAML::LoadFile(configpath);
 882   } catch (const runtime_error &e) {
 883     g_log<<Logger::Error<<"Unable to load configuration file '"<<configpath<<"': "<<e.what()<<endl;
 884     return false;
 885   }
 886
 887   bool retval = true;
 888
 889   if (config["keep"]) {
 890     try {
 891       config["keep"].as<uint16_t>();
 892     } catch (const runtime_error &e) {
 893       g_log<<Logger::Error<<"Unable to read 'keep' value: "<<e.what()<<endl;
 894       retval = false;
 895     }
 896   } else {
 897     config["keep"] = 20;
 898   }
 899
 900   if (config["axfr-timeout"]) {
 901     try {
 902       config["axfr-timeout"].as<uint16_t>();
 903     } catch (const runtime_error &e) {
 904       g_log<<Logger::Error<<"Unable to read 'axfr-timeout' value: "<<e.what()<<endl;
 905     }
 906   } else {
 907     config["axfr-timeout"] = 20;
 908   }
 909
 910   if (config["failed-soa-retry"]) {
 911     try {
 912       config["failed-soa-retry"].as<uint16_t>();
 913     } catch (const runtime_error &e) {
 914       g_log<<Logger::Error<<"Unable to read 'failed-soa-retry' value: "<<e.what()<<endl;
 915     }
 916   } else {
 917     config["failed-soa-retry"] = 30;
 918   }
 919
 920   if (config["tcp-in-threads"]) {
 921     try {
 922       config["tcp-in-threads"].as<uint16_t>();
 923     } catch (const runtime_error &e) {
 924       g_log<<Logger::Error<<"Unable to read 'tcp-in-threads' value: "<<e.what()<<endl;
 925     }
 926   } else {
 927     config["tcp-in-threads"] = 10;
 928   }
 929
 930   if (config["listen"]) {
 931     try {
 932       config["listen"].as<vector<ComboAddress>>();
 933     } catch (const runtime_error &e) {
 934       g_log<<Logger::Error<<"Unable to read 'listen' value: "<<e.what()<<endl;
 935       retval = false;
 936     }
 937   } else {
 938     config["listen"].push_back("127.0.0.1:53");
 939     config["listen"].push_back("[::1]:53");
 940   }
 941
 942   if (config["acl"]) {
 943     try {
 944       config["acl"].as<vector<string>>();
 945     } catch (const runtime_error &e) {
 946       g_log<<Logger::Error<<"Unable to read 'acl' value: "<<e.what()<<endl;
 947       retval = false;
 948     }
 949   } else {
 950     config["acl"].push_back("127.0.0.0/8");
 951     config["acl"].push_back("::1/128");
 952   }
 953
 954   if (config["work-dir"]) {
 955     try {
 956       config["work-dir"].as<string>();
 957     } catch(const runtime_error &e) {
 958       g_log<<Logger::Error<<"Unable to read 'work-dir' value: "<<e.what()<<endl;
 959       retval = false;
 960     }
 961   } else {
 962     char tmp[512];
 963     config["work-dir"] = getcwd(tmp, sizeof(tmp)) ? string(tmp) : "";;
 964   }
 965
 966   if (config["uid"]) {
 967     try {
 968       config["uid"].as<string>();
 969     } catch(const runtime_error &e) {
 970       g_log<<Logger::Error<<"Unable to read 'uid' value: "<<e.what()<<endl;
 971       retval = false;
 972     }
 973   }
 974
 975   if (config["gid"]) {
 976     try {
 977       config["gid"].as<string>();
 978     } catch(const runtime_error &e) {
 979       g_log<<Logger::Error<<"Unable to read 'gid' value: "<<e.what()<<endl;
 980       retval = false;
 981     }
 982   }
 983
 984   if (config["domains"]) {
 985     if (config["domains"].size() == 0) {
 986       g_log<<Logger::Error<<"No domains configured"<<endl;
 987       retval = false;
 988     }
 989     for (auto const &domain : config["domains"]) {
 990       try {
 991         if (!domain["domain"]) {
 992           g_log<<Logger::Error<<"An entry in 'domains' is missing a 'domain' key!"<<endl;
 993           retval = false;
 994           continue;
 995         }
 996         domain["domain"].as<DNSName>();
 997       } catch (const runtime_error &e) {
 998         g_log<<Logger::Error<<"Unable to read domain '"<<domain["domain"].as<string>()<<"': "<<e.what()<<endl;
 999       }
1000       try {
1001         if (!domain["master"]) {
1002           g_log<<Logger::Error<<"Domain '"<<domain["domain"].as<string>()<<"' has no master configured!"<<endl;
1003           retval = false;
1004           continue;
1005         }
1006         domain["master"].as<ComboAddress>();
1007       } catch (const runtime_error &e) {
1008         g_log<<Logger::Error<<"Unable to read domain '"<<domain["domain"].as<string>()<<"' master address: "<<e.what()<<endl;
1009         retval = false;
1010       }
1011     }
1012   } else {
1013     g_log<<Logger::Error<<"No domains configured"<<endl;
1014     retval = false;
1015   }
1016
1017   if (config["compress"]) {
1018     try {
1019       config["compress"].as<bool>();
1020     }
1021     catch (const runtime_error &e) {
1022       g_log<<Logger::Error<<"Unable to read 'compress' value: "<<e.what()<<endl;
1023       retval = false;
1024     }
1025   }
1026   else {
1027     config["compress"] = false;
1028   }
1029
1030   return retval;
1031 }
1032
1033 int main(int argc, char** argv) {
1034   g_log.setLoglevel(Logger::Notice);
1035   g_log.toConsole(Logger::Notice);
1036   g_log.setPrefixed(true);
1037   g_log.disableSyslog(true);
1038   g_log.setTimestamps(false);
1039   po::variables_map g_vm;
1040   try {
1041     po::options_description desc("IXFR distribution tool");
1042     desc.add_options()
1043       ("help", "produce help message")
1044       ("version", "Display the version of ixfrdist")
1045       ("verbose", "Be verbose")
1046       ("debug", "Be even more verbose")
1047       ("config", po::value<string>()->default_value(SYSCONFDIR + string("/ixfrdist.yml")), "Configuration file to use")
1048       ;
1049
1050     po::store(po::command_line_parser(argc, argv).options(desc).run(), g_vm);
1051     po::notify(g_vm);
1052
1053     if (g_vm.count("help") > 0) {
1054       usage(desc);
1055       return EXIT_SUCCESS;
1056     }
1057
1058     if (g_vm.count("version") > 0) {
1059       cout<<"ixfrdist "<<VERSION<<endl;
1060       return EXIT_SUCCESS;
1061     }
1062   } catch (po::error &e) {
1063     g_log<<Logger::Error<<e.what()<<". See `ixfrdist --help` for valid options"<<endl;
1064     return(EXIT_FAILURE);
1065   }
1066
1067   bool had_error = false;
1068
1069   if (g_vm.count("verbose")) {
1070     g_log.setLoglevel(Logger::Info);
1071     g_log.toConsole(Logger::Info);
1072   }
1073
1074   if (g_vm.count("debug") > 0) {
1075     g_log.setLoglevel(Logger::Debug);
1076     g_log.toConsole(Logger::Debug);
1077   }
1078
1079   g_log<<Logger::Notice<<"IXFR distributor version "<<VERSION<<" starting up!"<<endl;
1080
1081   YAML::Node config;
1082   if (!parseAndCheckConfig(g_vm["config"].as<string>(), config)) {
1083     // parseAndCheckConfig already logged whatever was wrong
1084     return EXIT_FAILURE;
1085   }
1086
1087   /*  From hereon out, we known that all the values in config are valid. */
1088
1089   for (auto const &domain : config["domains"]) {
1090     set<ComboAddress> s;
1091     s.insert(domain["master"].as<ComboAddress>());
1092     g_domainConfigs[domain["domain"].as<DNSName>()].masters = s;
1093   }
1094
1095   for (const auto &addr : config["acl"].as<vector<string>>()) {
1096     try {
1097       g_acl.addMask(addr);
1098     } catch (const NetmaskException &e) {
1099       g_log<<Logger::Error<<e.reason<<endl;
1100       had_error = true;
1101     }
1102   }
1103   g_log<<Logger::Notice<<"ACL set to "<<g_acl.toString()<<"."<<endl;
1104
1105   if (config["compress"]) {
1106     g_compress = config["compress"].as<bool>();
1107     if (g_compress) {
1108       g_log<<Logger::Notice<<"Record compression is enabled."<<endl;
1109     }
1110   }
1111
1112   FDMultiplexer* fdm = FDMultiplexer::getMultiplexerSilent();
1113   if (fdm == nullptr) {
1114     g_log<<Logger::Error<<"Could not enable a multiplexer for the listen sockets!"<<endl;
1115     return EXIT_FAILURE;
1116   }
1117
1118   set<int> allSockets;
1119   for (const auto& addr : config["listen"].as<vector<ComboAddress>>()) {
1120     for (const auto& stype : {SOCK_DGRAM, SOCK_STREAM}) {
1121       try {
1122         int s = SSocket(addr.sin4.sin_family, stype, 0);
1123         setNonBlocking(s);
1124         setReuseAddr(s);
1125         SBind(s, addr);
1126         if (stype == SOCK_STREAM) {
1127           SListen(s, 30); // TODO make this configurable
1128         }
1129         fdm->addReadFD(s, stype == SOCK_DGRAM ? handleUDPRequest : handleTCPRequest);
1130         allSockets.insert(s);
1131       } catch(runtime_error &e) {
1132         g_log<<Logger::Error<<e.what()<<endl;
1133         had_error = true;
1134         continue;
1135       }
1136     }
1137   }
1138
1139   int newgid = 0;
1140
1141   if (config["gid"]) {
1142     string gid = config["gid"].as<string>();
1143     if (!(newgid = atoi(gid.c_str()))) {
1144       struct group *gr = getgrnam(gid.c_str());
1145       if (gr == nullptr) {
1146         g_log<<Logger::Error<<"Can not determine group-id for gid "<<gid<<endl;
1147         had_error = true;
1148       } else {
1149         newgid = gr->gr_gid;
1150       }
1151     }
1152     g_log<<Logger::Notice<<"Dropping effective group-id to "<<newgid<<endl;
1153     if (setgid(newgid) < 0) {
1154       g_log<<Logger::Error<<"Could not set group id to "<<newgid<<": "<<stringerror()<<endl;
1155       had_error = true;
1156     }
1157   }
1158
1159   int newuid = 0;
1160
1161   if (config["uid"]) {
1162     string uid = config["uid"].as<string>();
1163     if (!(newuid = atoi(uid.c_str()))) {
1164       struct passwd *pw = getpwnam(uid.c_str());
1165       if (pw == nullptr) {
1166         g_log<<Logger::Error<<"Can not determine user-id for uid "<<uid<<endl;
1167         had_error = true;
1168       } else {
1169         newuid = pw->pw_uid;
1170       }
1171     }
1172
1173     struct passwd *pw = getpwuid(newuid);
1174     if (pw == nullptr) {
1175       if (setgroups(0, nullptr) < 0) {
1176         g_log<<Logger::Error<<"Unable to drop supplementary gids: "<<stringerror()<<endl;
1177         had_error = true;
1178       }
1179     } else {
1180       if (initgroups(pw->pw_name, newgid) < 0) {
1181         g_log<<Logger::Error<<"Unable to set supplementary groups: "<<stringerror()<<endl;
1182         had_error = true;
1183       }
1184     }
1185
1186     g_log<<Logger::Notice<<"Dropping effective user-id to "<<newuid<<endl;
1187     if (setuid(newuid) < 0) {
1188       g_log<<Logger::Error<<"Could not set user id to "<<newuid<<": "<<stringerror()<<endl;
1189       had_error = true;
1190     }
1191   }
1192
1193   if (had_error) {
1194     // We have already sent the errors to stderr, just die
1195     return EXIT_FAILURE;
1196   }
1197
1198   // It all starts here
1199   signal(SIGTERM, handleSignal);
1200   signal(SIGINT, handleSignal);
1201   signal(SIGPIPE, SIG_IGN);
1202
1203   // Init the things we need
1204   reportAllTypes();
1205
1206   dns_random_init();
1207
1208   std::thread ut(updateThread,
1209       config["work-dir"].as<string>(),
1210       config["keep"].as<uint16_t>(),
1211       config["axfr-timeout"].as<uint16_t>(),
1212       config["failed-soa-retry"].as<uint16_t>());
1213
1214   vector<std::thread> tcpHandlers;
1215   tcpHandlers.reserve(config["tcp-in-threads"].as<uint16_t>());
1216   for (size_t i = 0; i < tcpHandlers.capacity(); ++i) {
1217     tcpHandlers.push_back(std::thread(tcpWorker, i));
1218   }
1219
1220   struct timeval now;
1221   for(;;) {
1222     gettimeofday(&now, 0);
1223     fdm->run(&now);
1224     if (g_exiting) {
1225       g_log<<Logger::Debug<<"Closing listening sockets"<<endl;
1226       for (const int& fd : allSockets) {
1227         try {
1228           closesocket(fd);
1229         } catch(PDNSException &e) {
1230           g_log<<Logger::Error<<e.reason<<endl;
1231         }
1232       }
1233       break;
1234     }
1235   }
1236   g_log<<Logger::Debug<<"Waiting for al threads to stop"<<endl;
1237   g_tcpHandlerCV.notify_all();
1238   ut.join();
1239   for (auto &t : tcpHandlers) {
1240     t.join();
1241   }
1242   g_log<<Logger::Notice<<"IXFR distributor stopped"<<endl;
1243   return EXIT_SUCCESS;
1244 }