pdns/mastercommunicator.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 "auth-caches.hh"
  26 #include "utility.hh"
  27 #include <errno.h>
  28 #include "communicator.hh"
  29 #include <set>
  30 #include <boost/utility.hpp>
  31
  32 #include "dnsbackend.hh"
  33 #include "ueberbackend.hh"
  34 #include "packethandler.hh"
  35 #include "nameserver.hh"
  36 #include "resolver.hh"
  37 #include "logger.hh"
  38 #include "dns.hh"
  39 #include "arguments.hh"
  40 #include "packetcache.hh"
  41 #include "base64.hh"
  42 #include "namespaces.hh"
  43
  44
  45 void CommunicatorClass::queueNotifyDomain(const DomainInfo& di, UeberBackend* B)
  46 {
  47   bool hasQueuedItem=false;
  48   set<string> nsset, ips;
  49   DNSZoneRecord rr;
  50   FindNS fns;
  51
  52
  53   if (d_onlyNotify.size()) {
  54     B->lookup(QType(QType::NS), di.zone);
  55     while(B->get(rr))
  56       nsset.insert(getRR<NSRecordContent>(rr.dr)->getNS().toString());
  57
  58     for(set<string>::const_iterator j=nsset.begin();j!=nsset.end();++j) {
  59       vector<string> nsips=fns.lookup(DNSName(*j), B);
  60       if(nsips.empty())
  61         L<<Logger::Warning<<"Unable to queue notification of domain '"<<di.zone<<"': nameservers do not resolve!"<<endl;
  62       else
  63         for(vector<string>::const_iterator k=nsips.begin();k!=nsips.end();++k) {
  64           const ComboAddress caIp(*k, 53);
  65           if(!d_preventSelfNotification || !AddressIsUs(caIp)) {
  66             if(!d_onlyNotify.match(&caIp))
  67               L<<Logger::Info<<"Skipped notification of domain '"<<di.zone<<"' to "<<*j<<" because it does not match only-notify."<<endl;
  68             else
  69               ips.insert(caIp.toStringWithPort());
  70           }
  71         }
  72     }
  73
  74     for(set<string>::const_iterator j=ips.begin();j!=ips.end();++j) {
  75       L<<Logger::Warning<<"Queued notification of domain '"<<di.zone<<"' to "<<*j<<endl;
  76       d_nq.add(di.zone,*j);
  77       hasQueuedItem=true;
  78     }
  79   }
  80
  81   set<string> alsoNotify(d_alsoNotify);
  82   B->alsoNotifies(di.zone, &alsoNotify);
  83
  84   for(set<string>::const_iterator j=alsoNotify.begin();j!=alsoNotify.end();++j) {
  85     try {
  86       const ComboAddress caIp(*j, 53);
  87       L<<Logger::Warning<<"Queued also-notification of domain '"<<di.zone<<"' to "<<caIp.toStringWithPort()<<endl;
  88       if (!ips.count(caIp.toStringWithPort())) {
  89         ips.insert(caIp.toStringWithPort());
  90         d_nq.add(di.zone, caIp.toStringWithPort());
  91       }
  92       hasQueuedItem=true;
  93     }
  94     catch(PDNSException &e) {
  95       L<<Logger::Warning<<"Unparseable IP in ALSO-NOTIFY metadata of domain '"<<di.zone<<"'. Warning: "<<e.reason<<endl;
  96     }
  97   }
  98
  99   if (!hasQueuedItem)
 100     L<<Logger::Warning<<"Request to queue notification for domain '"<<di.zone<<"' was processed, but no valid nameservers or ALSO-NOTIFYs found. Not notifying!"<<endl;
 101 }
 102
 103
 104 bool CommunicatorClass::notifyDomain(const DNSName &domain)
 105 {
 106   DomainInfo di;
 107   UeberBackend B;
 108   if(!B.getDomainInfo(domain, di)) {
 109     L<<Logger::Error<<"No such domain '"<<domain<<"' in our database"<<endl;
 110     return false;
 111   }
 112   queueNotifyDomain(di, &B);
 113   // call backend and tell them we sent out the notification - even though that is premature
 114   di.backend->setNotified(di.id, di.serial);
 115
 116   return true;
 117 }
 118
 119 void NotificationQueue::dump()
 120 {
 121   cerr<<"Waiting for notification responses: "<<endl;
 122   for(NotificationRequest& nr :  d_nqueue) {
 123     cerr<<nr.domain<<", "<<nr.ip<<endl;
 124   }
 125 }
 126
 127 void CommunicatorClass::masterUpdateCheck(PacketHandler *P)
 128 {
 129   if(!::arg().mustDo("master"))
 130     return;
 131
 132   UeberBackend *B=P->getBackend();
 133   vector<DomainInfo> cmdomains;
 134   B->getUpdatedMasters(&cmdomains);
 135
 136   if(cmdomains.empty()) {
 137     if(d_masterschanged)
 138       L<<Logger::Warning<<"No master domains need notifications"<<endl;
 139     d_masterschanged=false;
 140   }
 141   else {
 142     d_masterschanged=true;
 143     L<<Logger::Error<<cmdomains.size()<<" domain"<<(cmdomains.size()>1 ? "s" : "")<<" for which we are master need"<<
 144       (cmdomains.size()>1 ? "" : "s")<<
 145       " notifications"<<endl;
 146   }
 147
 148   // figure out A records of everybody needing notification
 149   // do this via the FindNS class, d_fns
 150
 151   for(auto& di : cmdomains) {
 152     purgeAuthCachesExact(di.zone);
 153     queueNotifyDomain(di, B);
 154     di.backend->setNotified(di.id, di.serial);
 155   }
 156 }
 157
 158 time_t CommunicatorClass::doNotifications()
 159 {
 160   ComboAddress from;
 161   Utility::socklen_t fromlen;
 162   char buffer[1500];
 163   int sock;
 164   ssize_t size;
 165
 166   // receive incoming notifications on the nonblocking socket and take them off the list
 167   while(waitFor2Data(d_nsock4, d_nsock6, 0, 0, &sock) > 0) {
 168     fromlen=sizeof(from);
 169     size=recvfrom(sock,buffer,sizeof(buffer),0,(struct sockaddr *)&from,&fromlen);
 170     if(size < 0)
 171       break;
 172     DNSPacket p(true);
 173
 174     p.setRemote(&from);
 175
 176     if(p.parse(buffer,(size_t)size)<0) {
 177       L<<Logger::Warning<<"Unable to parse SOA notification answer from "<<p.getRemote()<<endl;
 178       continue;
 179     }
 180
 181     if(p.d.rcode)
 182       L<<Logger::Warning<<"Received unsuccessful notification report for '"<<p.qdomain<<"' from "<<from.toStringWithPort()<<", error: "<<RCode::to_s(p.d.rcode)<<endl;
 183
 184     if(d_nq.removeIf(from.toStringWithPort(), p.d.id, p.qdomain))
 185       L<<Logger::Warning<<"Removed from notification list: '"<<p.qdomain<<"' to "<<from.toStringWithPort()<<" "<< (p.d.rcode ? RCode::to_s(p.d.rcode) : "(was acknowledged)")<<endl;
 186     else {
 187       L<<Logger::Warning<<"Received spurious notify answer for '"<<p.qdomain<<"' from "<< from.toStringWithPort()<<endl;
 188       //d_nq.dump();
 189     }
 190   }
 191
 192   // send out possible new notifications
 193   DNSName domain;
 194   string ip;
 195   uint16_t id;
 196
 197   bool purged;
 198   while(d_nq.getOne(domain, ip, &id, purged)) {
 199     if(!purged) {
 200       try {
 201         ComboAddress remote(ip, 53); // default to 53
 202         if((d_nsock6 < 0 && remote.sin4.sin_family == AF_INET6) ||
 203            (d_nsock4 < 0 && remote.sin4.sin_family == AF_INET))
 204              continue; // don't try to notify what we can't!
 205         if(d_preventSelfNotification && AddressIsUs(remote))
 206           continue;
 207
 208         sendNotification(remote.sin4.sin_family == AF_INET ? d_nsock4 : d_nsock6, domain, remote, id);
 209         drillHole(domain, ip);
 210       }
 211       catch(ResolverException &re) {
 212         L<<Logger::Error<<"Error trying to resolve '"<<ip<<"' for notifying '"<<domain<<"' to server: "<<re.reason<<endl;
 213       }
 214     }
 215     else
 216       L<<Logger::Error<<"Notification for "<<domain<<" to "<<ip<<" failed after retries"<<endl;
 217   }
 218
 219   return d_nq.earliest();
 220 }
 221
 222 void CommunicatorClass::sendNotification(int sock, const DNSName& domain, const ComboAddress& remote, uint16_t id)
 223 {
 224   UeberBackend B;
 225   vector<string> meta;
 226   DNSName tsigkeyname;
 227   DNSName tsigalgorithm;
 228   string tsigsecret64;
 229   string tsigsecret;
 230
 231   if (B.getDomainMetadata(domain, "TSIG-ALLOW-AXFR", meta) && meta.size() > 0) {
 232     tsigkeyname = DNSName(meta[0]);
 233   }
 234
 235   vector<uint8_t> packet;
 236   DNSPacketWriter pw(packet, domain, QType::SOA, 1, Opcode::Notify);
 237   pw.getHeader()->id = id;
 238   pw.getHeader()->aa = true;
 239
 240   if (tsigkeyname.empty() == false) {
 241     B.getTSIGKey(tsigkeyname, &tsigalgorithm, &tsigsecret64);
 242     TSIGRecordContent trc;
 243     if (tsigalgorithm.toStringNoDot() == "hmac-md5")
 244       trc.d_algoName = DNSName(tsigalgorithm.toStringNoDot() + ".sig-alg.reg.int.");
 245     else
 246       trc.d_algoName = tsigalgorithm;
 247     trc.d_time = time(0);
 248     trc.d_fudge = 300;
 249     trc.d_origID=ntohs(id);
 250     trc.d_eRcode=0;
 251     B64Decode(tsigsecret64, tsigsecret);
 252     addTSIG(pw, trc, tsigkeyname, tsigsecret, "", false);
 253   }
 254
 255   if(sendto(sock, &packet[0], packet.size(), 0, (struct sockaddr*)(&remote), remote.getSocklen()) < 0) {
 256     throw ResolverException("Unable to send notify to "+remote.toStringWithPort()+": "+stringerror());
 257   }
 258 }
 259
 260 void CommunicatorClass::drillHole(const DNSName &domain, const string &ip)
 261 {
 262   Lock l(&d_holelock);
 263   d_holes[make_pair(domain,ip)]=time(0);
 264 }
 265
 266 bool CommunicatorClass::justNotified(const DNSName &domain, const string &ip)
 267 {
 268   Lock l(&d_holelock);
 269   if(d_holes.find(make_pair(domain,ip))==d_holes.end()) // no hole
 270     return false;
 271
 272   if(d_holes[make_pair(domain,ip)]>time(0)-900)    // recent hole
 273     return true;
 274
 275   // do we want to purge this? XXX FIXME
 276   return false;
 277 }
 278
 279 void CommunicatorClass::makeNotifySockets()
 280 {
 281   d_nsock4 = makeQuerySocket(ComboAddress(::arg()["query-local-address"]), true, ::arg().mustDo("non-local-bind"));
 282   if(!::arg()["query-local-address6"].empty())
 283     d_nsock6 = makeQuerySocket(ComboAddress(::arg()["query-local-address6"]), true, ::arg().mustDo("non-local-bind"));
 284   else
 285     d_nsock6 = -1;
 286 }
 287
 288 void CommunicatorClass::notify(const DNSName &domain, const string &ip)
 289 {
 290   d_nq.add(domain, ip);
 291   d_any_sem.post();
 292 }