pdns/rfc2136handler.cc

   1 #ifdef HAVE_CONFIG_H
   2 #include "config.h"
   3 #endif
   4 #include "packethandler.hh"
   5 #include "qtype.hh"
   6 #include "dnspacket.hh"
   7 #include "auth-caches.hh"
   8 #include "statbag.hh"
   9 #include "dnsseckeeper.hh"
  10 #include "base64.hh"
  11 #include "base32.hh"
  12
  13 #include "misc.hh"
  14 #include "arguments.hh"
  15 #include "resolver.hh"
  16 #include "dns_random.hh"
  17 #include "backends/gsql/ssql.hh"
  18 #include "communicator.hh"
  19
  20 extern StatBag S;
  21 extern CommunicatorClass Communicator;
  22
  23 pthread_mutex_t PacketHandler::s_rfc2136lock=PTHREAD_MUTEX_INITIALIZER;
  24
  25 // Implement section 3.2.1 and 3.2.2 of RFC2136
  26 int PacketHandler::checkUpdatePrerequisites(const DNSRecord *rr, DomainInfo *di) {
  27   if (rr->d_ttl != 0)
  28     return RCode::FormErr;
  29
  30   // 3.2.1 and 3.2.2 check content length.
  31   if ( (rr->d_class == QClass::NONE || rr->d_class == QClass::ANY) && rr->d_clen != 0)
  32     return RCode::FormErr;
  33
  34   bool foundRecord=false;
  35   DNSResourceRecord rec;
  36   di->backend->lookup(QType(QType::ANY), rr->d_name, nullptr, di->id);
  37   while(di->backend->get(rec)) {
  38     if (!rec.qtype.getCode())
  39       continue;
  40     if ((rr->d_type != QType::ANY && rec.qtype == rr->d_type) || rr->d_type == QType::ANY)
  41       foundRecord=true;
  42   }
  43
  44   // Section 3.2.1
  45   if (rr->d_class == QClass::ANY && !foundRecord) {
  46     if (rr->d_type == QType::ANY)
  47       return RCode::NXDomain;
  48     if (rr->d_type != QType::ANY)
  49       return RCode::NXRRSet;
  50   }
  51
  52   // Section 3.2.2
  53   if (rr->d_class == QClass::NONE && foundRecord) {
  54     if (rr->d_type == QType::ANY)
  55       return RCode::YXDomain;
  56     if (rr->d_type != QType::ANY)
  57       return RCode::YXRRSet;
  58   }
  59
  60   return RCode::NoError;
  61 }
  62
  63
  64 // Method implements section 3.4.1 of RFC2136
  65 int PacketHandler::checkUpdatePrescan(const DNSRecord *rr) {
  66   // The RFC stats that d_class != ZCLASS, but we only support the IN class.
  67   if (rr->d_class != QClass::IN && rr->d_class != QClass::NONE && rr->d_class != QClass::ANY)
  68     return RCode::FormErr;
  69
  70   QType qtype = QType(rr->d_type);
  71
  72   if (! qtype.isSupportedType())
  73     return RCode::FormErr;
  74
  75   if ((rr->d_class == QClass::NONE || rr->d_class == QClass::ANY) && rr->d_ttl != 0)
  76     return RCode::FormErr;
  77
  78   if (rr->d_class == QClass::ANY && rr->d_clen != 0)
  79     return RCode::FormErr;
  80
  81   if (qtype.isMetadataType())
  82       return RCode::FormErr;
  83
  84   if (rr->d_class != QClass::ANY && qtype.getCode() == QType::ANY)
  85     return RCode::FormErr;
  86
  87   return RCode::NoError;
  88 }
  89
  90
  91 // Implements section 3.4.2 of RFC2136
  92 uint PacketHandler::performUpdate(const string &msgPrefix, const DNSRecord *rr, DomainInfo *di, bool isPresigned, bool* narrow, bool* haveNSEC3, NSEC3PARAMRecordContent *ns3pr, bool *updatedSerial) {
  93
  94   QType rrType = QType(rr->d_type);
  95
  96   if (rrType == QType::NSEC || rrType == QType::NSEC3) {
  97     g_log<<Logger::Warning<<msgPrefix<<"Trying to add/update/delete "<<rr->d_name<<"|"<<rrType.getName()<<". These are generated records, ignoring!"<<endl;
  98     return 0;
  99   }
 100
 101   if (!isPresigned && ((!::arg().mustDo("direct-dnskey") && rrType == QType::DNSKEY) || rrType == QType::RRSIG)) {
 102     g_log<<Logger::Warning<<msgPrefix<<"Trying to add/update/delete "<<rr->d_name<<"|"<<rrType.getName()<<" in non-presigned zone, ignoring!"<<endl;
 103     return 0;
 104   }
 105
 106   if ((rrType == QType::NSEC3PARAM || rrType == QType::DNSKEY) && rr->d_name != di->zone) {
 107     g_log<<Logger::Warning<<msgPrefix<<"Trying to add/update/delete "<<rr->d_name<<"|"<<rrType.getName()<<", "<<rrType.getName()<<" must be at zone apex, ignoring!"<<endl;
 108     return 0;
 109   }
 110
 111
 112   uint changedRecords = 0;
 113   DNSResourceRecord rec;
 114   vector<DNSResourceRecord> rrset, recordsToDelete;
 115   set<DNSName> delnonterm, insnonterm; // used to (at the end) fix ENT records.
 116
 117
 118   if (rr->d_class == QClass::IN) { // 3.4.2.2 QClass::IN means insert or update
 119     DLOG(g_log<<msgPrefix<<"Add/Update record (QClass == IN) "<<rr->d_name<<"|"<<rrType.getName()<<endl);
 120
 121     if (rrType == QType::NSEC3PARAM) {
 122       g_log<<Logger::Notice<<msgPrefix<<"Adding/updating NSEC3PARAM for zone, resetting ordernames."<<endl;
 123
 124       NSEC3PARAMRecordContent nsec3param(rr->d_content->getZoneRepresentation(), di->zone.toString() /* FIXME400 huh */);
 125       *narrow = false; // adding a NSEC3 will cause narrow mode to be dropped, as you cannot specify that in a NSEC3PARAM record
 126       d_dk.setNSEC3PARAM(di->zone, nsec3param, (*narrow));
 127
 128       *haveNSEC3 = d_dk.getNSEC3PARAM(di->zone, ns3pr, narrow);
 129
 130       vector<DNSResourceRecord> rrs;
 131       set<DNSName> qnames, nssets, dssets;
 132       di->backend->list(di->zone, di->id);
 133       while (di->backend->get(rec)) {
 134         qnames.insert(rec.qname);
 135         if(rec.qtype.getCode() == QType::NS && rec.qname != di->zone)
 136           nssets.insert(rec.qname);
 137         if(rec.qtype.getCode() == QType::DS)
 138           dssets.insert(rec.qname);
 139       }
 140
 141       DNSName shorter;
 142       for(const auto& qname: qnames) {
 143         shorter = qname;
 144         int ddepth = 0;
 145         do {
 146           if(qname == di->zone)
 147             break;
 148           if(nssets.count(shorter))
 149             ++ddepth;
 150         } while(shorter.chopOff());
 151
 152         DNSName ordername = DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, qname)));
 153         if (! *narrow && (ddepth == 0 || (ddepth == 1 && nssets.count(qname)))) {
 154           di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, ordername, (ddepth == 0 ));
 155
 156           if (nssets.count(qname)) {
 157             if (ns3pr->d_flags)
 158               di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), false, QType::NS );
 159             di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), false, QType::A);
 160             di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), false, QType::AAAA);
 161           }
 162         } else {
 163           di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), (ddepth == 0));
 164         }
 165         if (ddepth == 1 || dssets.count(qname)) // FIXME400 && ?
 166           di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, ordername, false, QType::DS);
 167       }
 168       return 1;
 169     }
 170
 171
 172
 173     bool foundRecord = false;
 174     di->backend->lookup(rrType, rr->d_name, nullptr, di->id);
 175     while (di->backend->get(rec)) {
 176       rrset.push_back(rec);
 177       foundRecord = true;
 178     }
 179
 180     if (foundRecord) {
 181
 182       if (rrType == QType::SOA) { // SOA updates require the serial to be higher than the current
 183         SOAData sdOld, sdUpdate;
 184         DNSResourceRecord *oldRec = &rrset.front();
 185         fillSOAData(oldRec->content, sdOld);
 186         oldRec->setContent(rr->d_content->getZoneRepresentation());
 187         fillSOAData(oldRec->content, sdUpdate);
 188         if (rfc1982LessThan(sdOld.serial, sdUpdate.serial)) {
 189           di->backend->replaceRRSet(di->id, oldRec->qname, oldRec->qtype, rrset);
 190           *updatedSerial = true;
 191           changedRecords++;
 192           g_log<<Logger::Notice<<msgPrefix<<"Replacing record "<<rr->d_name<<"|"<<rrType.getName()<<endl;
 193         } else {
 194           g_log<<Logger::Notice<<msgPrefix<<"Provided serial ("<<sdUpdate.serial<<") is older than the current serial ("<<sdOld.serial<<"), ignoring SOA update."<<endl;
 195         }
 196
 197       // It's not possible to have multiple CNAME's with the same NAME. So we always update.
 198       } else if (rrType == QType::CNAME) {
 199         int changedCNames = 0;
 200         for (vector<DNSResourceRecord>::iterator i = rrset.begin(); i != rrset.end(); i++) {
 201           if (i->ttl != rr->d_ttl || i->content != rr->d_content->getZoneRepresentation()) {
 202             i->ttl = rr->d_ttl;
 203             i->setContent(rr->d_content->getZoneRepresentation());
 204             changedCNames++;
 205           }
 206         }
 207         if (changedCNames > 0) {
 208           di->backend->replaceRRSet(di->id, rr->d_name, rrType, rrset);
 209           g_log<<Logger::Notice<<msgPrefix<<"Replacing record "<<rr->d_name<<"|"<<rrType.getName()<<endl;
 210           changedRecords += changedCNames;
 211         } else {
 212           g_log<<Logger::Notice<<msgPrefix<<"Replace for record "<<rr->d_name<<"|"<<rrType.getName()<<" requested, but no changes made."<<endl;
 213         }
 214
 215       // In any other case, we must check if the TYPE and RDATA match to provide an update (which effectively means a update of TTL)
 216       } else {
 217         int updateTTL=0;
 218         foundRecord = false;
 219         for (vector<DNSResourceRecord>::iterator i = rrset.begin(); i != rrset.end(); i++) {
 220           string content = rr->d_content->getZoneRepresentation();
 221           if (rrType == i->qtype.getCode() && i->getZoneRepresentation() == content) {
 222             foundRecord=true;
 223             if (i->ttl != rr->d_ttl)  {
 224               i->ttl = rr->d_ttl;
 225               updateTTL++;
 226             }
 227           }
 228         }
 229         if (updateTTL > 0) {
 230           di->backend->replaceRRSet(di->id, rr->d_name, rrType, rrset);
 231           g_log<<Logger::Notice<<msgPrefix<<"Replacing record "<<rr->d_name<<"|"<<rrType.getName()<<endl;
 232           changedRecords += updateTTL;
 233         } else {
 234           g_log<<Logger::Notice<<msgPrefix<<"Replace for record "<<rr->d_name<<"|"<<rrType.getName()<<" requested, but no changes made."<<endl;
 235         }
 236       }
 237
 238       // ReplaceRRSet dumps our ordername and auth flag, so we need to correct it if we have changed records.
 239       // We can take the auth flag from the first RR in the set, as the name is different, so should the auth be.
 240       if (changedRecords > 0) {
 241         bool auth = rrset.front().auth;
 242
 243         if(*haveNSEC3) {
 244           DNSName ordername;
 245           if(! *narrow)
 246             ordername=DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, rr->d_name)));
 247
 248           if (*narrow)
 249             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), auth);
 250           else
 251             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, ordername, auth);
 252           if(!auth || rrType == QType::DS) {
 253             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::NS);
 254             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::A);
 255             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::AAAA);
 256           }
 257
 258         } else { // NSEC
 259           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, rr->d_name.makeRelative(di->zone), auth);
 260           if(!auth || rrType == QType::DS) {
 261             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::A);
 262             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::AAAA);
 263           }
 264         }
 265       }
 266
 267     } // if (foundRecord)
 268
 269     // If we haven't found a record that matches, we must add it.
 270     if (! foundRecord) {
 271       g_log<<Logger::Notice<<msgPrefix<<"Adding record "<<rr->d_name<<"|"<<rrType.getName()<<endl;
 272       delnonterm.insert(rr->d_name); // always remove any ENT's in the place where we're going to add a record.
 273       auto newRec = DNSResourceRecord::fromWire(*rr);
 274       newRec.domain_id = di->id;
 275       newRec.auth = (rr->d_name == di->zone || rrType.getCode() != QType::NS);
 276       di->backend->feedRecord(newRec, DNSName());
 277       changedRecords++;
 278
 279
 280       // because we added a record, we need to fix DNSSEC data.
 281       DNSName shorter(rr->d_name);
 282       bool auth=newRec.auth;
 283       bool fixDS = (rrType == QType::DS);
 284
 285       if (di->zone != shorter) { // Everything at APEX is auth=1 && no ENT's
 286         do {
 287
 288           if (di->zone == shorter)
 289             break;
 290
 291           bool foundShorter = false;
 292           di->backend->lookup(QType(QType::ANY), shorter, nullptr, di->id);
 293           while (di->backend->get(rec)) {
 294             if (rec.qname == rr->d_name && rec.qtype == QType::DS)
 295               fixDS = true;
 296             if (shorter != rr->d_name)
 297               foundShorter = true;
 298             if (rec.qtype == QType::NS) // are we inserting below a delegate?
 299               auth=false;
 300           }
 301
 302           if (!foundShorter && auth && shorter != rr->d_name) // haven't found any record at current level, insert ENT.
 303             insnonterm.insert(shorter);
 304           if (foundShorter)
 305             break; // if we find a shorter record, we can stop searching
 306         } while(shorter.chopOff());
 307       }
 308
 309       if(*haveNSEC3)
 310       {
 311         DNSName ordername;
 312         if(! *narrow)
 313           ordername=DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, rr->d_name)));
 314
 315         if (*narrow)
 316           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), auth);
 317         else
 318           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, ordername, auth);
 319
 320         if (fixDS)
 321           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, ordername, true, QType::DS);
 322
 323         if(!auth)
 324         {
 325           if (ns3pr->d_flags)
 326             di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::NS);
 327           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::A);
 328           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::AAAA);
 329         }
 330       }
 331       else // NSEC
 332       {
 333         DNSName ordername=rr->d_name.makeRelative(di->zone);
 334         di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, ordername, auth);
 335         if (fixDS) {
 336           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, ordername, true, QType::DS);
 337         }
 338         if(!auth) {
 339           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::A);
 340           di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), false, QType::AAAA);
 341         }
 342       }
 343
 344
 345       // If we insert an NS, all the records below it become non auth - so, we're inserting a delegate.
 346       // Auth can only be false when the rr->d_name is not the zone
 347       if (auth == false && rrType == QType::NS) {
 348         DLOG(g_log<<msgPrefix<<"Going to fix auth flags below "<<rr->d_name<<endl);
 349         insnonterm.clear(); // No ENT's are needed below delegates (auth=0)
 350         vector<DNSName> qnames;
 351         di->backend->listSubZone(rr->d_name, di->id);
 352         while(di->backend->get(rec)) {
 353           if (rec.qtype.getCode() && rec.qtype.getCode() != QType::DS && rr->d_name != rec.qname) // Skip ENT, DS and our already corrected record.
 354             qnames.push_back(rec.qname);
 355         }
 356         for(vector<DNSName>::const_iterator qname=qnames.begin(); qname != qnames.end(); ++qname) {
 357           if(*haveNSEC3)  {
 358             DNSName ordername;
 359             if(! *narrow)
 360               ordername=DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, *qname)));
 361
 362             if (*narrow)
 363               di->backend->updateDNSSECOrderNameAndAuth(di->id, rr->d_name, DNSName(), auth); // FIXME400 no *qname here?
 364             else
 365               di->backend->updateDNSSECOrderNameAndAuth(di->id, *qname, ordername, auth);
 366
 367             if (ns3pr->d_flags)
 368               di->backend->updateDNSSECOrderNameAndAuth(di->id, *qname, DNSName(), false, QType::NS);
 369           }
 370           else { // NSEC
 371             DNSName ordername=DNSName(*qname).makeRelative(di->zone);
 372             di->backend->updateDNSSECOrderNameAndAuth(di->id, *qname, ordername, false, QType::NS);
 373           }
 374
 375           di->backend->updateDNSSECOrderNameAndAuth(di->id, *qname, DNSName(), false, QType::A);
 376           di->backend->updateDNSSECOrderNameAndAuth(di->id, *qname, DNSName(), false, QType::AAAA);
 377         }
 378       }
 379     }
 380   } // rr->d_class == QClass::IN
 381
 382
 383   // Delete records - section 3.4.2.3 and 3.4.2.4 with the exception of the 'always leave 1 NS rule' as that's handled by
 384   // the code that calls this performUpdate().
 385   if ((rr->d_class == QClass::ANY || rr->d_class == QClass::NONE) && rrType != QType::SOA) { // never delete a SOA.
 386     DLOG(g_log<<msgPrefix<<"Deleting records: "<<rr->d_name<<"; QClass:"<<rr->d_class<<"; rrType: "<<rrType.getName()<<endl);
 387
 388     if (rrType == QType::NSEC3PARAM) {
 389       g_log<<Logger::Notice<<msgPrefix<<"Deleting NSEC3PARAM from zone, resetting ordernames."<<endl;
 390       if (rr->d_class == QClass::ANY)
 391         d_dk.unsetNSEC3PARAM(rr->d_name);
 392       else if (rr->d_class == QClass::NONE) {
 393         NSEC3PARAMRecordContent nsec3rr(rr->d_content->getZoneRepresentation(), di->zone.toString() /* FIXME400 huh */);
 394         if (ns3pr->getZoneRepresentation() == nsec3rr.getZoneRepresentation())
 395           d_dk.unsetNSEC3PARAM(rr->d_name);
 396         else
 397           return 0;
 398       } else
 399         return 0;
 400
 401       // We retrieve new values, other RR's in this update package might need it as well.
 402       *haveNSEC3 = d_dk.getNSEC3PARAM(di->zone, ns3pr, narrow);
 403
 404       vector<DNSResourceRecord> rrs;
 405       set<DNSName> qnames, nssets, dssets, ents;
 406       di->backend->list(di->zone, di->id);
 407       while (di->backend->get(rec)) {
 408         qnames.insert(rec.qname);
 409         if(rec.qtype.getCode() == QType::NS && rec.qname != di->zone)
 410           nssets.insert(rec.qname);
 411         if(rec.qtype.getCode() == QType::DS)
 412           dssets.insert(rec.qname);
 413         if(!rec.qtype.getCode())
 414           ents.insert(rec.qname);
 415       }
 416
 417       DNSName shorter;
 418       string hashed;
 419       for(const DNSName& qname :  qnames) {
 420         shorter = qname;
 421         int ddepth = 0;
 422         do {
 423           if(qname == di->zone)
 424             break;
 425           if(nssets.count(shorter))
 426             ++ddepth;
 427         } while(shorter.chopOff());
 428
 429         DNSName ordername=qname.makeRelative(di->zone);
 430         if (!ents.count(qname) && (ddepth == 0 || (ddepth == 1 && nssets.count(qname)))) {
 431           di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, ordername, (ddepth == 0));
 432
 433           if (nssets.count(qname)) {
 434             di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), false, QType::A);
 435             di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), false, QType::AAAA);
 436           }
 437         } else {
 438           di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, DNSName(), (ddepth == 0));
 439         }
 440         if (ddepth == 1 || dssets.count(qname))
 441           di->backend->updateDNSSECOrderNameAndAuth(di->id, qname, ordername, true, QType::DS);
 442       }
 443       return 1;
 444     } // end of NSEC3PARAM delete block
 445
 446
 447     di->backend->lookup(rrType, rr->d_name, nullptr, di->id);
 448     while(di->backend->get(rec)) {
 449       if (rr->d_class == QClass::ANY) { // 3.4.2.3
 450         if (rec.qname == di->zone && (rec.qtype == QType::NS || rec.qtype == QType::SOA)) // Never delete all SOA and NS's
 451           rrset.push_back(rec);
 452         else
 453           recordsToDelete.push_back(rec);
 454       }
 455       if (rr->d_class == QClass::NONE) { // 3.4.2.4
 456         if (rrType == rec.qtype && rec.getZoneRepresentation() == rr->d_content->getZoneRepresentation())
 457           recordsToDelete.push_back(rec);
 458         else
 459           rrset.push_back(rec);
 460       }
 461     }
 462
 463     if (recordsToDelete.size()) {
 464       di->backend->replaceRRSet(di->id, rr->d_name, rrType, rrset);
 465       g_log<<Logger::Notice<<msgPrefix<<"Deleting record "<<rr->d_name<<"|"<<rrType.getName()<<endl;
 466       changedRecords += recordsToDelete.size();
 467
 468
 469       // If we've removed a delegate, we need to reset ordername/auth for some records.
 470       if (rrType == QType::NS && rr->d_name != di->zone) {
 471         vector<DNSName> belowOldDelegate, nsRecs, updateAuthFlag;
 472         di->backend->listSubZone(rr->d_name, di->id);
 473         while (di->backend->get(rec)) {
 474           if (rec.qtype.getCode()) // skip ENT records, they are always auth=false
 475             belowOldDelegate.push_back(rec.qname);
 476           if (rec.qtype.getCode() == QType::NS && rec.qname != rr->d_name)
 477             nsRecs.push_back(rec.qname);
 478         }
 479
 480         for(auto &belowOldDel: belowOldDelegate)
 481         {
 482           bool isBelowDelegate = false;
 483           for(const auto & ns: nsRecs) {
 484             if (ns.isPartOf(belowOldDel)) {
 485               isBelowDelegate=true;
 486               break;
 487             }
 488           }
 489           if (!isBelowDelegate)
 490             updateAuthFlag.push_back(belowOldDel);
 491         }
 492
 493         for (const auto &changeRec:updateAuthFlag) {
 494           if(*haveNSEC3)  {
 495             DNSName ordername;
 496             if(! *narrow)
 497               ordername=DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, changeRec)));
 498
 499             di->backend->updateDNSSECOrderNameAndAuth(di->id, changeRec, ordername, true);
 500           }
 501           else { // NSEC
 502             DNSName ordername=changeRec.makeRelative(di->zone);
 503             di->backend->updateDNSSECOrderNameAndAuth(di->id, changeRec, ordername, true);
 504           }
 505         }
 506       }
 507
 508       // Fix ENT records.
 509       // We must check if we have a record below the current level and if we removed the 'last' record
 510       // on that level. If so, we must insert an ENT record.
 511       // We take extra care here to not 'include' the record that we just deleted. Some backends will still return it as they only reload on a commit.
 512       bool foundDeeper = false, foundOtherWithSameName = false;
 513       di->backend->listSubZone(rr->d_name, di->id);
 514       while (di->backend->get(rec)) {
 515         if (rec.qname == rr->d_name && !count(recordsToDelete.begin(), recordsToDelete.end(), rec))
 516           foundOtherWithSameName = true;
 517         if (rec.qname != rr->d_name && rec.qtype.getCode() != QType::NS) //Skip NS records, as this would be a delegate that we can ignore as this does not require us to create a ENT
 518           foundDeeper = true;
 519       }
 520
 521       if (foundDeeper && !foundOtherWithSameName) {
 522         insnonterm.insert(rr->d_name);
 523       } else if (!foundOtherWithSameName) {
 524         // If we didn't have to insert an ENT, we might have deleted a record at very deep level
 525         // and we must then clean up the ENT's above the deleted record.
 526         DNSName shorter(rr->d_name);
 527         while (shorter != di->zone) {
 528           shorter.chopOff();
 529           bool foundRealRR = false;
 530           bool foundEnt = false;
 531
 532           // The reason for a listSubZone here is because might go up the tree and find the ENT of another branch
 533           // consider these non ENT-records:
 534           // b.c.d.e.test.com
 535           // b.d.e.test.com
 536           // if we delete b.c.d.e.test.com, we go up to d.e.test.com and then find b.d.e.test.com because that's below d.e.test.com.
 537           // At that point we can stop deleting ENT's because the tree is in tact again.
 538           di->backend->listSubZone(shorter, di->id);
 539
 540           while (di->backend->get(rec)) {
 541             if (rec.qtype.getCode())
 542               foundRealRR = true;
 543             else
 544               foundEnt = true;
 545           }
 546           if (!foundRealRR) {
 547             if (foundEnt) // only delete the ENT if we actually found one.
 548               delnonterm.insert(shorter);
 549           } else
 550             break;
 551         }
 552       }
 553     } else { // if (recordsToDelete.size())
 554       g_log<<Logger::Notice<<msgPrefix<<"Deletion for record "<<rr->d_name<<"|"<<rrType.getName()<<" requested, but not found."<<endl;
 555     }
 556   } // (End of delete block d_class == ANY || d_class == NONE
 557
 558
 559
 560   //Insert and delete ENT's
 561   if (insnonterm.size() > 0 || delnonterm.size() > 0) {
 562     DLOG(g_log<<msgPrefix<<"Updating ENT records - "<<insnonterm.size()<<"|"<<delnonterm.size()<<endl);
 563     di->backend->updateEmptyNonTerminals(di->id, insnonterm, delnonterm, false);
 564     for (const auto &i: insnonterm) {
 565       string hashed;
 566       if(*haveNSEC3)
 567       {
 568         DNSName ordername;
 569         if(! *narrow)
 570           ordername=DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, i)));
 571         di->backend->updateDNSSECOrderNameAndAuth(di->id, i, ordername, true);
 572       }
 573     }
 574   }
 575
 576   return changedRecords;
 577 }
 578
 579 int PacketHandler::forwardPacket(const string &msgPrefix, DNSPacket *p, DomainInfo *di) {
 580   vector<string> forward;
 581   B.getDomainMetadata(p->qdomain, "FORWARD-DNSUPDATE", forward);
 582
 583   if (forward.size() == 0 && ! ::arg().mustDo("forward-dnsupdate")) {
 584     g_log<<Logger::Notice<<msgPrefix<<"Not configured to forward to master, returning Refused."<<endl;
 585     return RCode::Refused;
 586   }
 587
 588   for(const auto& remote : di->masters) {
 589     g_log<<Logger::Notice<<msgPrefix<<"Forwarding packet to master "<<remote<<endl;
 590
 591     ComboAddress local;
 592     if (remote.sin4.sin_family == AF_INET && !::arg()["query-local-address"].empty()) {
 593       local = ComboAddress(::arg()["query-local-address"]);
 594     } else if(remote.sin4.sin_family == AF_INET6 && !::arg()["query-local-address6"].empty()) {
 595       local = ComboAddress(::arg()["query-local-address6"]);
 596     } else {
 597       continue;
 598     }
 599     int sock = makeQuerySocket(local, false); // create TCP socket. RFC2136 section 6.2 seems to be ok with this.
 600     if(sock < 0) {
 601       g_log<<Logger::Error<<msgPrefix<<"Error creating socket: "<<stringerror()<<endl;
 602       continue;
 603     }
 604
 605     if( connect(sock, (struct sockaddr*)&remote, remote.getSocklen()) < 0 ) {
 606       g_log<<Logger::Error<<msgPrefix<<"Failed to connect to "<<remote.toStringWithPort()<<": "<<stringerror()<<endl;
 607       try {
 608         closesocket(sock);
 609       }
 610       catch(const PDNSException& e) {
 611         g_log<<Logger::Error<<"Error closing master forwarding socket after connect() failed: "<<e.reason<<endl;
 612       }
 613       continue;
 614     }
 615
 616     DNSPacket forwardPacket(*p);
 617     forwardPacket.setID(dns_random(0xffff));
 618     forwardPacket.setRemote(&remote);
 619     uint16_t len=htons(forwardPacket.getString().length());
 620     string buffer((const char*)&len, 2);
 621     buffer.append(forwardPacket.getString());
 622     if(write(sock, buffer.c_str(), buffer.length()) < 0) {
 623       g_log<<Logger::Error<<msgPrefix<<"Unable to forward update message to "<<remote.toStringWithPort()<<", error:"<<stringerror()<<endl;
 624       try {
 625         closesocket(sock);
 626       }
 627       catch(const PDNSException& e) {
 628         g_log<<Logger::Error<<"Error closing master forwarding socket after write() failed: "<<e.reason<<endl;
 629       }
 630       continue;
 631     }
 632
 633     int res = waitForData(sock, 10, 0);
 634     if (!res) {
 635       g_log<<Logger::Error<<msgPrefix<<"Timeout waiting for reply from master at "<<remote.toStringWithPort()<<endl;
 636       try {
 637         closesocket(sock);
 638       }
 639       catch(const PDNSException& e) {
 640         g_log<<Logger::Error<<"Error closing master forwarding socket after a timeout occured: "<<e.reason<<endl;
 641       }
 642       continue;
 643     }
 644     if (res < 0) {
 645       g_log<<Logger::Error<<msgPrefix<<"Error waiting for answer from master at "<<remote.toStringWithPort()<<", error:"<<stringerror()<<endl;
 646       try {
 647         closesocket(sock);
 648       }
 649       catch(const PDNSException& e) {
 650         g_log<<Logger::Error<<"Error closing master forwarding socket after an error occured: "<<e.reason<<endl;
 651       }
 652       continue;
 653     }
 654
 655     unsigned char lenBuf[2];
 656     ssize_t recvRes;
 657     recvRes = recv(sock, &lenBuf, sizeof(lenBuf), 0);
 658     if (recvRes < 0 || static_cast<size_t>(recvRes) < sizeof(lenBuf)) {
 659       g_log<<Logger::Error<<msgPrefix<<"Could not receive data (length) from master at "<<remote.toStringWithPort()<<", error:"<<stringerror()<<endl;
 660       try {
 661         closesocket(sock);
 662       }
 663       catch(const PDNSException& e) {
 664         g_log<<Logger::Error<<"Error closing master forwarding socket after recv() failed: "<<e.reason<<endl;
 665       }
 666       continue;
 667     }
 668     size_t packetLen = lenBuf[0]*256+lenBuf[1];
 669
 670     buffer.resize(packetLen);
 671     recvRes = recv(sock, &buffer.at(0), packetLen, 0);
 672     if (recvRes < 0) {
 673       g_log<<Logger::Error<<msgPrefix<<"Could not receive data (dnspacket) from master at "<<remote.toStringWithPort()<<", error:"<<stringerror()<<endl;
 674       try {
 675         closesocket(sock);
 676       }
 677       catch(const PDNSException& e) {
 678         g_log<<Logger::Error<<"Error closing master forwarding socket after recv() failed: "<<e.reason<<endl;
 679       }
 680       continue;
 681     }
 682     try {
 683       closesocket(sock);
 684     }
 685     catch(const PDNSException& e) {
 686       g_log<<Logger::Error<<"Error closing master forwarding socket: "<<e.reason<<endl;
 687     }
 688
 689     try {
 690       MOADNSParser mdp(false, buffer.data(), static_cast<unsigned int>(recvRes));
 691       g_log<<Logger::Info<<msgPrefix<<"Forward update message to "<<remote.toStringWithPort()<<", result was RCode "<<mdp.d_header.rcode<<endl;
 692       return mdp.d_header.rcode;
 693     }
 694     catch (...) {
 695       g_log<<Logger::Error<<msgPrefix<<"Failed to parse response packet from master at "<<remote.toStringWithPort()<<endl;
 696       continue;
 697     }
 698   }
 699   g_log<<Logger::Error<<msgPrefix<<"Failed to forward packet to master(s). Returning ServFail."<<endl;
 700   return RCode::ServFail;
 701
 702 }
 703
 704 int PacketHandler::processUpdate(DNSPacket *p) {
 705   if (! ::arg().mustDo("dnsupdate"))
 706     return RCode::Refused;
 707
 708   string msgPrefix="UPDATE (" + itoa(p->d.id) + ") from " + p->getRemote().toString() + " for " + p->qdomain.toLogString() + ": ";
 709   g_log<<Logger::Info<<msgPrefix<<"Processing started."<<endl;
 710
 711   // if there is policy, we delegate all checks to it
 712   if (this->d_update_policy_lua == NULL) {
 713
 714     // Check permissions - IP based
 715     vector<string> allowedRanges;
 716     B.getDomainMetadata(p->qdomain, "ALLOW-DNSUPDATE-FROM", allowedRanges);
 717     if (! ::arg()["allow-dnsupdate-from"].empty())
 718       stringtok(allowedRanges, ::arg()["allow-dnsupdate-from"], ", \t" );
 719
 720     NetmaskGroup ng;
 721     for(vector<string>::const_iterator i=allowedRanges.begin(); i != allowedRanges.end(); i++)
 722       ng.addMask(*i);
 723
 724     if ( ! ng.match(&p->d_remote)) {
 725       g_log<<Logger::Error<<msgPrefix<<"Remote not listed in allow-dnsupdate-from or domainmetadata. Sending REFUSED"<<endl;
 726       return RCode::Refused;
 727     }
 728
 729
 730     // Check permissions - TSIG based.
 731     vector<string> tsigKeys;
 732     B.getDomainMetadata(p->qdomain, "TSIG-ALLOW-DNSUPDATE", tsigKeys);
 733     if (tsigKeys.size() > 0) {
 734       bool validKey = false;
 735
 736       TSIGRecordContent trc;
 737       DNSName inputkey;
 738       string message;
 739       if (! p->getTSIGDetails(&trc,  &inputkey)) {
 740         g_log<<Logger::Error<<msgPrefix<<"TSIG key required, but packet does not contain key. Sending REFUSED"<<endl;
 741         return RCode::Refused;
 742       }
 743
 744       if (p->d_tsig_algo == TSIG_GSS) {
 745         GssName inputname(p->d_peer_principal); // match against principal since GSS
 746         for(vector<string>::const_iterator key=tsigKeys.begin(); key != tsigKeys.end(); key++) {
 747           if (inputname.match(*key)) {
 748             validKey = true;
 749             break;
 750           }
 751         }
 752       } else {
 753         for(vector<string>::const_iterator key=tsigKeys.begin(); key != tsigKeys.end(); key++) {
 754           if (inputkey == DNSName(*key)) { // because checkForCorrectTSIG has already been performed earlier on, if the names of the ky match with the domain given. THis is valid.
 755             validKey=true;
 756             break;
 757           }
 758         }
 759       }
 760
 761       if (!validKey) {
 762         g_log<<Logger::Error<<msgPrefix<<"TSIG key ("<<inputkey<<") required, but no matching key found in domainmetadata, tried "<<tsigKeys.size()<<". Sending REFUSED"<<endl;
 763         return RCode::Refused;
 764       }
 765     }
 766
 767     if (tsigKeys.size() == 0 && p->d_havetsig)
 768       g_log<<Logger::Warning<<msgPrefix<<"TSIG is provided, but domain is not secured with TSIG. Processing continues"<<endl;
 769
 770   }
 771
 772   // RFC2136 uses the same DNS Header and Message as defined in RFC1035.
 773   // This means we can use the MOADNSParser to parse the incoming packet. The result is that we have some different
 774   // variable names during the use of our MOADNSParser.
 775   MOADNSParser mdp(false, p->getString());
 776   if (mdp.d_header.qdcount != 1) {
 777     g_log<<Logger::Warning<<msgPrefix<<"Zone Count is not 1, sending FormErr"<<endl;
 778     return RCode::FormErr;
 779   }
 780
 781   if (p->qtype.getCode() != QType::SOA) { // RFC2136 2.3 - ZTYPE must be SOA
 782     g_log<<Logger::Warning<<msgPrefix<<"Query ZTYPE is not SOA, sending FormErr"<<endl;
 783     return RCode::FormErr;
 784   }
 785
 786   if (p->qclass != QClass::IN) {
 787     g_log<<Logger::Warning<<msgPrefix<<"Class is not IN, sending NotAuth"<<endl;
 788     return RCode::NotAuth;
 789   }
 790
 791   DomainInfo di;
 792   di.backend=0;
 793   if(!B.getDomainInfo(p->qdomain, di) || !di.backend) {
 794     g_log<<Logger::Error<<msgPrefix<<"Can't determine backend for domain '"<<p->qdomain<<"' (or backend does not support DNS update operation)"<<endl;
 795     return RCode::NotAuth;
 796   }
 797
 798   if (di.kind == DomainInfo::Slave)
 799     return forwardPacket(msgPrefix, p, &di);
 800
 801   // Check if all the records provided are within the zone
 802   for(MOADNSParser::answers_t::const_iterator i=mdp.d_answers.begin(); i != mdp.d_answers.end(); ++i) {
 803     const DNSRecord *rr = &i->first;
 804     // Skip this check for other field types (like the TSIG -  which is in the additional section)
 805     // For a TSIG, the label is the dnskey, so it does not pass the endOn validation.
 806     if (! (rr->d_place == DNSResourceRecord::ANSWER || rr->d_place == DNSResourceRecord::AUTHORITY))
 807       continue;
 808
 809     if (!rr->d_name.isPartOf(di.zone)) {
 810       g_log<<Logger::Error<<msgPrefix<<"Received update/record out of zone, sending NotZone."<<endl;
 811       return RCode::NotZone;
 812     }
 813   }
 814
 815
 816   Lock l(&s_rfc2136lock); //TODO: i think this lock can be per zone, not for everything
 817   g_log<<Logger::Info<<msgPrefix<<"starting transaction."<<endl;
 818   if (!di.backend->startTransaction(p->qdomain, -1)) { // Not giving the domain_id means that we do not delete the existing records.
 819     g_log<<Logger::Error<<msgPrefix<<"Backend for domain "<<p->qdomain<<" does not support transaction. Can't do Update packet."<<endl;
 820     return RCode::NotImp;
 821   }
 822
 823   // 3.2.1 and 3.2.2 - Prerequisite check
 824   for(MOADNSParser::answers_t::const_iterator i=mdp.d_answers.begin(); i != mdp.d_answers.end(); ++i) {
 825     const DNSRecord *rr = &i->first;
 826     if (rr->d_place == DNSResourceRecord::ANSWER) {
 827       int res = checkUpdatePrerequisites(rr, &di);
 828       if (res>0) {
 829         g_log<<Logger::Error<<msgPrefix<<"Failed PreRequisites check for "<<rr->d_name.toLogString()<<", returning "<<RCode::to_s(res)<<endl;
 830         di.backend->abortTransaction();
 831         return res;
 832       }
 833     }
 834   }
 835
 836   // 3.2.3 - Prerequisite check - this is outside of updatePrerequisitesCheck because we check an RRSet and not the RR.
 837   typedef pair<DNSName, QType> rrSetKey_t;
 838   typedef vector<DNSResourceRecord> rrVector_t;
 839   typedef std::map<rrSetKey_t, rrVector_t> RRsetMap_t;
 840   RRsetMap_t preReqRRsets;
 841   for(const auto& i : mdp.d_answers) {
 842     const DNSRecord* rr = &i.first;
 843     if (rr->d_place == DNSResourceRecord::ANSWER) {
 844       // Last line of 3.2.3
 845       if (rr->d_class != QClass::IN && rr->d_class != QClass::NONE && rr->d_class != QClass::ANY)
 846         return RCode::FormErr;
 847
 848       if (rr->d_class == QClass::IN) {
 849         rrSetKey_t key = make_pair(rr->d_name, QType(rr->d_type));
 850         rrVector_t *vec = &preReqRRsets[key];
 851         vec->push_back(DNSResourceRecord::fromWire(*rr));
 852       }
 853     }
 854   }
 855
 856   if (preReqRRsets.size() > 0) {
 857     RRsetMap_t zoneRRsets;
 858     for (RRsetMap_t::iterator preRRSet = preReqRRsets.begin(); preRRSet != preReqRRsets.end(); ++preRRSet) {
 859       rrSetKey_t rrSet=preRRSet->first;
 860       rrVector_t *vec = &preRRSet->second;
 861
 862       DNSResourceRecord rec;
 863       di.backend->lookup(QType(QType::ANY), rrSet.first, nullptr, di.id);
 864       uint16_t foundRR=0, matchRR=0;
 865       while (di.backend->get(rec)) {
 866         if (rec.qtype == rrSet.second) {
 867           foundRR++;
 868           for(rrVector_t::iterator rrItem=vec->begin(); rrItem != vec->end(); ++rrItem) {
 869             rrItem->ttl = rec.ttl; // The compare one line below also compares TTL, so we make them equal because TTL is not user within prerequisite checks.
 870             if (*rrItem == rec)
 871               matchRR++;
 872           }
 873         }
 874       }
 875       if (matchRR != foundRR || foundRR != vec->size()) {
 876         g_log<<Logger::Error<<msgPrefix<<"Failed PreRequisites check (RRs differ), returning NXRRSet"<<endl;
 877         di.backend->abortTransaction();
 878         return RCode::NXRRSet;
 879       }
 880     }
 881   }
 882
 883
 884
 885   // 3.4 - Prescan & Add/Update/Delete records - is all done within a try block.
 886   try {
 887     uint changedRecords = 0;
 888     // 3.4.1 - Prescan section
 889     for(MOADNSParser::answers_t::const_iterator i=mdp.d_answers.begin(); i != mdp.d_answers.end(); ++i) {
 890       const DNSRecord *rr = &i->first;
 891       if (rr->d_place == DNSResourceRecord::AUTHORITY) {
 892         int res = checkUpdatePrescan(rr);
 893         if (res>0) {
 894           g_log<<Logger::Error<<msgPrefix<<"Failed prescan check, returning "<<res<<endl;
 895           di.backend->abortTransaction();
 896           return res;
 897         }
 898       }
 899     }
 900
 901     bool updatedSerial=false;
 902     NSEC3PARAMRecordContent ns3pr;
 903     bool narrow=false;
 904     bool haveNSEC3 = d_dk.getNSEC3PARAM(di.zone, &ns3pr, &narrow);
 905     bool isPresigned = d_dk.isPresigned(di.zone);
 906
 907     // 3.4.2 - Perform the updates.
 908     // There's a special condition where deleting the last NS record at zone apex is never deleted (3.4.2.4)
 909     // This means we must do it outside the normal performUpdate() because that focusses only on a separate RR.
 910     vector<const DNSRecord *> nsRRtoDelete;
 911
 912     // Another special case is the addition of both a CNAME and a non-CNAME for the same name (#6270)
 913     set<DNSName> cn, nocn;
 914     for (const auto &rr : mdp.d_answers) {
 915       if (rr.first.d_place == DNSResourceRecord::AUTHORITY && rr.first.d_class == QClass::IN && rr.first.d_ttl > 0) {
 916         // Addition
 917         if (rr.first.d_type == QType::CNAME) {
 918           cn.insert(rr.first.d_name);
 919         } else if (rr.first.d_type != QType::RRSIG) {
 920           nocn.insert(rr.first.d_name);
 921         }
 922       }
 923     }
 924     for (auto const &n : cn) {
 925       if (nocn.count(n) > 0) {
 926         g_log<<Logger::Error<<msgPrefix<<"Refusing update, found CNAME and non-CNAME addition"<<endl;
 927         di.backend->abortTransaction();
 928         return RCode::FormErr;
 929       }
 930     }
 931
 932     vector<const DNSRecord *> cnamesToAdd, nonCnamesToAdd;
 933     for(MOADNSParser::answers_t::const_iterator i=mdp.d_answers.begin(); i != mdp.d_answers.end(); ++i) {
 934       const DNSRecord *rr = &i->first;
 935       if (rr->d_place == DNSResourceRecord::AUTHORITY) {
 936         /* see if it's permitted by policy */
 937         if (this->d_update_policy_lua != NULL) {
 938           if (this->d_update_policy_lua->updatePolicy(rr->d_name, QType(rr->d_type), di.zone, p) == false) {
 939             g_log<<Logger::Warning<<msgPrefix<<"Refusing update for " << rr->d_name << "/" << QType(rr->d_type).getName() << ": Not permitted by policy"<<endl;
 940             continue;
 941           } else {
 942             g_log<<Logger::Debug<<msgPrefix<<"Accepting update for " << rr->d_name << "/" << QType(rr->d_type).getName() << ": Permitted by policy"<<endl;
 943           }
 944         }
 945
 946         if (rr->d_class == QClass::NONE  && rr->d_type == QType::NS && rr->d_name == di.zone)
 947           nsRRtoDelete.push_back(rr);
 948         else if (rr->d_class == QClass::IN &&  rr->d_ttl > 0) {
 949           if (rr->d_type == QType::CNAME) {
 950             cnamesToAdd.push_back(rr);
 951           } else {
 952             nonCnamesToAdd.push_back(rr);
 953           }
 954         }
 955         else
 956           changedRecords += performUpdate(msgPrefix, rr, &di, isPresigned, &narrow, &haveNSEC3, &ns3pr, &updatedSerial);
 957       }
 958     }
 959     for (const auto &rr : cnamesToAdd) {
 960       DNSResourceRecord rec;
 961       di.backend->lookup(QType(QType::ANY), rr->d_name, nullptr, di.id);
 962       while (di.backend->get(rec)) {
 963         if (rec.qtype != QType::CNAME && rec.qtype != QType::RRSIG) {
 964           // leave database handle in a consistent state
 965           while (di.backend->get(rec))
 966             ;
 967           g_log<<Logger::Warning<<msgPrefix<<"Refusing update for " << rr->d_name << "/" << QType(rr->d_type).getName() << ": Data other than CNAME exists for the same name"<<endl;
 968           di.backend->abortTransaction();
 969           return RCode::Refused;
 970         }
 971       }
 972       changedRecords += performUpdate(msgPrefix, rr, &di, isPresigned, &narrow, &haveNSEC3, &ns3pr, &updatedSerial);
 973     }
 974     for (const auto &rr : nonCnamesToAdd) {
 975       DNSResourceRecord rec;
 976       di.backend->lookup(QType(QType::CNAME), rr->d_name, nullptr, di.id);
 977       while (di.backend->get(rec)) {
 978         if (rec.qtype == QType::CNAME && rr->d_type != QType::RRSIG) {
 979           // leave database handle in a consistent state
 980           while (di.backend->get(rec))
 981             ;
 982           g_log<<Logger::Warning<<msgPrefix<<"Refusing update for " << rr->d_name << "/" << QType(rr->d_type).getName() << ": CNAME exists for the same name"<<endl;
 983           di.backend->abortTransaction();
 984           return RCode::Refused;
 985         }
 986       }
 987       changedRecords += performUpdate(msgPrefix, rr, &di, isPresigned, &narrow, &haveNSEC3, &ns3pr, &updatedSerial);
 988     }
 989     if (nsRRtoDelete.size()) {
 990       vector<DNSResourceRecord> nsRRInZone;
 991       DNSResourceRecord rec;
 992       di.backend->lookup(QType(QType::NS), di.zone, nullptr, di.id);
 993       while (di.backend->get(rec)) {
 994         nsRRInZone.push_back(rec);
 995       }
 996       if (nsRRInZone.size() > nsRRtoDelete.size()) { // only delete if the NS's we delete are less then what we have in the zone (3.4.2.4)
 997         for (vector<DNSResourceRecord>::iterator inZone=nsRRInZone.begin(); inZone != nsRRInZone.end(); inZone++) {
 998           for (vector<const DNSRecord *>::iterator rr=nsRRtoDelete.begin(); rr != nsRRtoDelete.end(); rr++) {
 999             if (inZone->getZoneRepresentation() == (*rr)->d_content->getZoneRepresentation())
1000               changedRecords += performUpdate(msgPrefix, *rr, &di, isPresigned, &narrow, &haveNSEC3, &ns3pr, &updatedSerial);
1001           }
1002         }
1003       }
1004     }
1005
1006     // Section 3.6 - Update the SOA serial - outside of performUpdate because we do a SOA update for the complete update message
1007     if (changedRecords > 0 && !updatedSerial) {
1008       increaseSerial(msgPrefix, &di, haveNSEC3, narrow, &ns3pr);
1009       changedRecords++;
1010     }
1011
1012     if (changedRecords > 0) {
1013       if (!di.backend->commitTransaction()) {
1014        g_log<<Logger::Error<<msgPrefix<<"Failed to commit updates!"<<endl;
1015         return RCode::ServFail;
1016       }
1017
1018       S.deposit("dnsupdate-changes", changedRecords);
1019
1020       // Purge the records!
1021       string zone(di.zone.toString());
1022       zone.append("$");
1023       purgeAuthCaches(zone);
1024
1025       // Notify slaves
1026       if (di.kind == DomainInfo::Master) {
1027         vector<string> notify;
1028         B.getDomainMetadata(p->qdomain, "NOTIFY-DNSUPDATE", notify);
1029         if (!notify.empty() && notify.front() == "1") {
1030           Communicator.notifyDomain(di.zone);
1031         }
1032       }
1033
1034       g_log<<Logger::Info<<msgPrefix<<"Update completed, "<<changedRecords<<" changed records committed."<<endl;
1035     } else {
1036       //No change, no commit, we perform abort() because some backends might like this more.
1037       g_log<<Logger::Info<<msgPrefix<<"Update completed, 0 changes, rolling back."<<endl;
1038       di.backend->abortTransaction();
1039     }
1040     return RCode::NoError; //rfc 2136 3.4.2.5
1041   }
1042   catch (SSqlException &e) {
1043     g_log<<Logger::Error<<msgPrefix<<"Caught SSqlException: "<<e.txtReason()<<"; Sending ServFail!"<<endl;
1044     di.backend->abortTransaction();
1045     return RCode::ServFail;
1046   }
1047   catch (DBException &e) {
1048     g_log<<Logger::Error<<msgPrefix<<"Caught DBException: "<<e.reason<<"; Sending ServFail!"<<endl;
1049     di.backend->abortTransaction();
1050     return RCode::ServFail;
1051   }
1052   catch (PDNSException &e) {
1053     g_log<<Logger::Error<<msgPrefix<<"Caught PDNSException: "<<e.reason<<"; Sending ServFail!"<<endl;
1054     di.backend->abortTransaction();
1055     return RCode::ServFail;
1056   }
1057   catch(std::exception &e) {
1058     g_log<<Logger::Error<<msgPrefix<<"Caught std:exception: "<<e.what()<<"; Sending ServFail!"<<endl;
1059     di.backend->abortTransaction();
1060     return RCode::ServFail;
1061   }
1062   catch (...) {
1063     g_log<<Logger::Error<<msgPrefix<<"Caught unknown exception when performing update. Sending ServFail!"<<endl;
1064     di.backend->abortTransaction();
1065     return RCode::ServFail;
1066   }
1067 }
1068
1069 void PacketHandler::increaseSerial(const string &msgPrefix, const DomainInfo *di, bool haveNSEC3, bool narrow, const NSEC3PARAMRecordContent *ns3pr) {
1070   SOAData sd;
1071   if (!di->backend->getSOA(di->zone, sd, true)) {
1072     throw PDNSException("SOA-Serial update failed because there was no SOA. Wowie.");
1073   }
1074
1075   uint32_t oldSerial = sd.serial;
1076   if (oldSerial == 0) { // using Autoserial, leave the serial alone.
1077     g_log<<Logger::Notice<<msgPrefix<<"AutoSerial in use in domain \""<<di->zone.toLogString()<<"\", not updating SOA serial."<<endl;
1078     return;
1079   }
1080
1081   vector<string> soaEdit2136Setting;
1082   B.getDomainMetadata(di->zone, "SOA-EDIT-DNSUPDATE", soaEdit2136Setting);
1083   string soaEdit2136 = "DEFAULT";
1084   string soaEdit;
1085   if (!soaEdit2136Setting.empty()) {
1086     soaEdit2136 = soaEdit2136Setting[0];
1087     if (pdns_iequals(soaEdit2136, "SOA-EDIT") || pdns_iequals(soaEdit2136,"SOA-EDIT-INCREASE") ){
1088       string soaEditSetting;
1089       d_dk.getSoaEdit(di->zone, soaEditSetting);
1090       if (soaEditSetting.empty()) {
1091         g_log<<Logger::Error<<msgPrefix<<"Using "<<soaEdit2136<<" for SOA-EDIT-DNSUPDATE increase on DNS update, but SOA-EDIT is not set for domain \""<< di->zone.toLogString() <<"\". Using DEFAULT for SOA-EDIT-DNSUPDATE"<<endl;
1092         soaEdit2136 = "DEFAULT";
1093       } else
1094         soaEdit = soaEditSetting;
1095     }
1096   }
1097
1098   DNSResourceRecord rr;
1099   if (makeIncreasedSOARecord(sd, soaEdit2136, soaEdit, rr)) {
1100     di->backend->replaceRRSet(di->id, rr.qname, rr.qtype, vector<DNSResourceRecord>(1, rr));
1101     g_log << Logger::Notice << msgPrefix << "Increasing SOA serial (" << oldSerial << " -> " << sd.serial << ")" << endl;
1102
1103     //Correct ordername + auth flag
1104     if (haveNSEC3) {
1105       DNSName ordername;
1106       if (!narrow)
1107         ordername = DNSName(toBase32Hex(hashQNameWithSalt(*ns3pr, rr.qname)));
1108
1109       di->backend->updateDNSSECOrderNameAndAuth(di->id, rr.qname, ordername, true);
1110     } else { // NSEC
1111       DNSName ordername = rr.qname.makeRelative(di->zone);
1112       di->backend->updateDNSSECOrderNameAndAuth(di->id, rr.qname, ordername, true);
1113     }
1114   }
1115 }