pdns/mastercommunicator.cc

   1 /*
   2     PowerDNS Versatile Database Driven Nameserver
   3     Copyright (C) 2002-2011  PowerDNS.COM BV
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License version 2 as
   7     published by the Free Software Foundation;
   8
   9     Additionally, the license of this program contains a special
  10     exception which allows to distribute the program in binary form when
  11     it is linked against OpenSSL.
  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 St, Fifth Floor, Boston, MA  02110-1301  USA
  21 */
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25 #include "packetcache.hh"
  26 #include "utility.hh"
  27 #include <errno.h>
  28 #include "communicator.hh"
  29 #include <set>
  30 #include <boost/utility.hpp>
  31 #include <boost/foreach.hpp>
  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 <boost/lexical_cast.hpp>
  42
  43 #include "namespaces.hh"
  44
  45
  46 void CommunicatorClass::queueNotifyDomain(const string &domain, UeberBackend *B)
  47 {
  48   bool hasQueuedItem=false;
  49   set<string> nsset, ips;
  50   DNSResourceRecord rr;
  51   FindNS fns;
  52
  53   B->lookup(QType(QType::NS),domain);
  54   while(B->get(rr))
  55     nsset.insert(rr.content);
  56
  57   for(set<string>::const_iterator j=nsset.begin();j!=nsset.end();++j) {
  58     vector<string> nsips=fns.lookup(*j, B);
  59     if(nsips.empty())
  60       L<<Logger::Warning<<"Unable to queue notification of domain '"<<domain<<"': nameservers do not resolve!"<<endl;
  61     else
  62       for(vector<string>::const_iterator k=nsips.begin();k!=nsips.end();++k) {
  63         const ComboAddress caIp(*k, 53);
  64         if(!d_preventSelfNotification || !AddressIsUs(caIp)) {
  65           if(!d_onlyNotify.match(&caIp))
  66             L<<Logger::Info<<"Skipped notification of domain '"<<domain<<"' to "<<*j<<" because it does not match only-notify."<<endl;
  67           else
  68             ips.insert(caIp.toStringWithPort());
  69         }
  70       }
  71   }
  72
  73   for(set<string>::const_iterator j=ips.begin();j!=ips.end();++j) {
  74     L<<Logger::Warning<<"Queued notification of domain '"<<domain<<"' to "<<*j<<endl;
  75     d_nq.add(domain,*j);
  76     hasQueuedItem=true;
  77   }
  78
  79   set<string> alsoNotify(d_alsoNotify);
  80   B->alsoNotifies(domain, &alsoNotify);
  81
  82   for(set<string>::const_iterator j=alsoNotify.begin();j!=alsoNotify.end();++j) {
  83     try {
  84       const ComboAddress caIp(*j, 53);
  85       L<<Logger::Warning<<"Queued also-notification of domain '"<<domain<<"' to "<<caIp.toStringWithPort()<<endl;
  86       if (!ips.count(caIp.toStringWithPort())) {
  87         ips.insert(caIp.toStringWithPort());
  88         d_nq.add(domain, caIp.toStringWithPort());
  89       }
  90       hasQueuedItem=true;
  91     }
  92     catch(PDNSException &e) {
  93       L<<Logger::Warning<<"Unparseable IP in ALSO-NOTIFY metadata of domain '"<<domain<<"'. Warning: "<<e.reason<<endl;
  94     }
  95   }
  96
  97   if (!hasQueuedItem)
  98     L<<Logger::Warning<<"Request to queue notification for domain '"<<domain<<"' was processed, but no valid nameservers or ALSO-NOTIFYs found. Not notifying!"<<endl;
  99 }
 100
 101
 102 bool CommunicatorClass::notifyDomain(const string &domain)
 103 {
 104   DomainInfo di;
 105   UeberBackend B;
 106   if(!B.getDomainInfo(domain, di)) {
 107     L<<Logger::Error<<"No such domain '"<<domain<<"' in our database"<<endl;
 108     return false;
 109   }
 110   queueNotifyDomain(domain, &B);
 111   // call backend and tell them we sent out the notification - even though that is premature
 112   di.backend->setNotified(di.id, di.serial);
 113
 114   return true;
 115 }
 116
 117 void NotificationQueue::dump()
 118 {
 119   cerr<<"Waiting for notification responses: "<<endl;
 120   BOOST_FOREACH(NotificationRequest& nr, d_nqueue) {
 121     cerr<<nr.domain<<", "<<nr.ip<<endl;
 122   }
 123 }
 124
 125 void CommunicatorClass::masterUpdateCheck(PacketHandler *P)
 126 {
 127   if(!::arg().mustDo("master"))
 128     return;
 129
 130   UeberBackend *B=P->getBackend();
 131   vector<DomainInfo> cmdomains;
 132   B->getUpdatedMasters(&cmdomains);
 133
 134   if(cmdomains.empty()) {
 135     if(d_masterschanged)
 136       L<<Logger::Warning<<"No master domains need notifications"<<endl;
 137     d_masterschanged=false;
 138   }
 139   else {
 140     d_masterschanged=true;
 141     L<<Logger::Error<<cmdomains.size()<<" domain"<<(cmdomains.size()>1 ? "s" : "")<<" for which we are master need"<<
 142       (cmdomains.size()>1 ? "" : "s")<<
 143       " notifications"<<endl;
 144   }
 145
 146   // figure out A records of everybody needing notification
 147   // do this via the FindNS class, d_fns
 148
 149   for(vector<DomainInfo>::const_iterator i=cmdomains.begin();i!=cmdomains.end();++i) {
 150     extern PacketCache PC;
 151     PC.purge(i->zone); // fixes cvstrac ticket #30
 152     queueNotifyDomain(i->zone,P->getBackend());
 153     i->backend->setNotified(i->id,i->serial);
 154   }
 155 }
 156
 157 time_t CommunicatorClass::doNotifications()
 158 {
 159   ComboAddress from;
 160   Utility::socklen_t fromlen;
 161   char buffer[1500];
 162   int size, sock;
 163
 164   // receive incoming notifications on the nonblocking socket and take them off the list
 165   while(waitFor2Data(d_nsock4, d_nsock6, 0, 0, &sock) > 0) {
 166     fromlen=sizeof(from);
 167     size=recvfrom(sock,buffer,sizeof(buffer),0,(struct sockaddr *)&from,&fromlen);
 168     if(size < 0)
 169       break;
 170     DNSPacket p;
 171
 172     p.setRemote(&from);
 173
 174     if(p.parse(buffer,size)<0) {
 175       L<<Logger::Warning<<"Unable to parse SOA notification answer from "<<p.getRemote()<<endl;
 176       continue;
 177     }
 178
 179     if(p.d.rcode)
 180       L<<Logger::Warning<<"Received unsuccessful notification report for '"<<p.qdomain<<"' from "<<from.toStringWithPort()<<", error: "<<RCode::to_s(p.d.rcode)<<endl;
 181
 182     if(d_nq.removeIf(from.toStringWithPort(), p.d.id, p.qdomain))
 183       L<<Logger::Warning<<"Removed from notification list: '"<<p.qdomain<<"' to "<<from.toStringWithPort()<<" "<< (p.d.rcode ? RCode::to_s(p.d.rcode) : "(was acknowledged)")<<endl;
 184     else {
 185       L<<Logger::Warning<<"Received spurious notify answer for '"<<p.qdomain<<"' from "<< from.toStringWithPort()<<endl;
 186       //d_nq.dump();
 187     }
 188   }
 189
 190   // send out possible new notifications
 191   string domain, ip;
 192   uint16_t id;
 193
 194   bool purged;
 195   while(d_nq.getOne(domain, ip, &id, purged)) {
 196     if(!purged) {
 197       try {
 198         ComboAddress remote(ip, 53); // default to 53
 199         if((d_nsock6 < 0 && remote.sin4.sin_family == AF_INET6) ||
 200            (d_nsock4 < 0 && remote.sin4.sin_family == AF_INET))
 201              continue; // don't try to notify what we can't!
 202         if(d_preventSelfNotification && AddressIsUs(remote))
 203           continue;
 204
 205         sendNotification(remote.sin4.sin_family == AF_INET ? d_nsock4 : d_nsock6, domain, remote, id);
 206         drillHole(domain, ip);
 207       }
 208       catch(ResolverException &re) {
 209         L<<Logger::Error<<"Error trying to resolve '"+ip+"' for notifying '"+domain+"' to server: "+re.reason<<endl;
 210       }
 211     }
 212     else
 213       L<<Logger::Error<<Logger::NTLog<<"Notification for "<<domain<<" to "<<ip<<" failed after retries"<<endl;
 214   }
 215
 216   return d_nq.earliest();
 217 }
 218
 219 void CommunicatorClass::sendNotification(int sock, const string& domain, const ComboAddress& remote, uint16_t id)
 220 {
 221   vector<uint8_t> packet;
 222   DNSPacketWriter pw(packet, domain, QType::SOA, 1, Opcode::Notify);
 223   pw.getHeader()->id = id;
 224   pw.getHeader()->aa = true;
 225
 226   if(sendto(sock, &packet[0], packet.size(), 0, (struct sockaddr*)(&remote), remote.getSocklen()) < 0) {
 227     throw ResolverException("Unable to send notify to "+remote.toStringWithPort()+": "+stringerror());
 228   }
 229 }
 230
 231 void CommunicatorClass::drillHole(const string &domain, const string &ip)
 232 {
 233   Lock l(&d_holelock);
 234   d_holes[make_pair(domain,ip)]=time(0);
 235 }
 236
 237 bool CommunicatorClass::justNotified(const string &domain, const string &ip)
 238 {
 239   Lock l(&d_holelock);
 240   if(d_holes.find(make_pair(domain,ip))==d_holes.end()) // no hole
 241     return false;
 242
 243   if(d_holes[make_pair(domain,ip)]>time(0)-900)    // recent hole
 244     return true;
 245
 246   // do we want to purge this? XXX FIXME
 247   return false;
 248 }
 249
 250 void CommunicatorClass::makeNotifySockets()
 251 {
 252   d_nsock4 = makeQuerySocket(ComboAddress(::arg()["query-local-address"]), true);
 253   if(!::arg()["query-local-address6"].empty())
 254     d_nsock6 = makeQuerySocket(ComboAddress(::arg()["query-local-address6"]), true);
 255   else
 256     d_nsock6 = -1;
 257 }
 258
 259 void CommunicatorClass::notify(const string &domain, const string &ip)
 260 {
 261   d_nq.add(domain, ip);
 262   d_any_sem.post();
 263 }
 264