pdns/communicator.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 "packetcache.hh"
  26 #include "utility.hh"
  27 #include <errno.h>
  28 #include "communicator.hh"
  29 #include <set>
  30 #include <boost/utility.hpp>
  31 #include "dnsbackend.hh"
  32 #include "ueberbackend.hh"
  33 #include "packethandler.hh"
  34 #include "resolver.hh"
  35 #include "logger.hh"
  36 #include "dns.hh"
  37 #include "arguments.hh"
  38 #include "packetcache.hh"
  39 #include "threadname.hh"
  40
  41 // there can be MANY OF THESE
  42 void CommunicatorClass::retrievalLoopThread(void)
  43 {
  44   setThreadName("pdns/comm-retre");
  45   for(;;) {
  46     d_suck_sem.wait();
  47     SuckRequest sr;
  48     {
  49       Lock l(&d_lock);
  50       if(d_suckdomains.empty())
  51         continue;
  52
  53       sr=d_suckdomains.front();
  54       d_suckdomains.pop_front();
  55     }
  56     suck(sr.domain, sr.master);
  57   }
  58 }
  59
  60 void CommunicatorClass::loadArgsIntoSet(const char *listname, set<string> &listset)
  61 {
  62   vector<string> parts;
  63   stringtok(parts, ::arg()[listname], ", \t");
  64   for (vector<string>::const_iterator iter = parts.begin(); iter != parts.end(); ++iter) {
  65     try {
  66       ComboAddress caIp(*iter, 53);
  67       listset.insert(caIp.toStringWithPort());
  68     }
  69     catch(PDNSException &e) {
  70       g_log<<Logger::Error<<"Unparseable IP in "<<listname<<". Error: "<<e.reason<<endl;
  71       _exit(1);
  72     }
  73   }
  74 }
  75
  76 void CommunicatorClass::go()
  77 {
  78   try {
  79     PacketHandler::s_allowNotifyFrom.toMasks(::arg()["allow-notify-from"] );
  80   }
  81   catch(PDNSException &e) {
  82     g_log<<Logger::Error<<"Unparseable IP in allow-notify-from. Error: "<<e.reason<<endl;
  83     _exit(1);
  84   }
  85
  86   pthread_t tid;
  87   pthread_create(&tid,0,&launchhelper,this); // Starts CommunicatorClass::mainloop()
  88   for(int n=0; n < ::arg().asNum("retrieval-threads", 1); ++n)
  89     pthread_create(&tid, 0, &retrieveLaunchhelper, this); // Starts CommunicatorClass::retrievalLoopThread()
  90
  91   d_preventSelfNotification = ::arg().mustDo("prevent-self-notification");
  92
  93   try {
  94     d_onlyNotify.toMasks(::arg()["only-notify"]);
  95   }
  96   catch(PDNSException &e) {
  97     g_log<<Logger::Error<<"Unparseable IP in only-notify. Error: "<<e.reason<<endl;
  98     _exit(1);
  99   }
 100
 101   loadArgsIntoSet("also-notify", d_alsoNotify);
 102
 103   loadArgsIntoSet("forward-notify", PacketHandler::s_forwardNotify);
 104 }
 105
 106 void CommunicatorClass::mainloop(void)
 107 {
 108   try {
 109     setThreadName("pdns/comm-main");
 110     signal(SIGPIPE,SIG_IGN);
 111     g_log<<Logger::Error<<"Master/slave communicator launching"<<endl;
 112     PacketHandler P;
 113     d_tickinterval=::arg().asNum("slave-cycle-interval");
 114     makeNotifySockets();
 115
 116     int rc;
 117     time_t next, tick;
 118
 119     for(;;) {
 120       slaveRefresh(&P);
 121       masterUpdateCheck(&P);
 122       tick=doNotifications(); // this processes any notification acknowledgements and actually send out our own notifications
 123
 124       tick = min (tick, d_tickinterval);
 125
 126       next=time(0)+tick;
 127
 128       while(time(0) < next) {
 129         rc=d_any_sem.tryWait();
 130
 131         if(rc) {
 132           bool extraSlaveRefresh = false;
 133           Utility::sleep(1);
 134           {
 135             Lock l(&d_lock);
 136             if (d_tocheck.size())
 137               extraSlaveRefresh = true;
 138           }
 139           if (extraSlaveRefresh)
 140             slaveRefresh(&P);
 141         }
 142         else {
 143           // eat up extra posts to avoid busy looping if many posts were done
 144           while (d_any_sem.tryWait() == 0) {
 145           }
 146           break; // something happened
 147         }
 148         // this gets executed at least once every second
 149         doNotifications();
 150       }
 151     }
 152   }
 153   catch(PDNSException &ae) {
 154     g_log<<Logger::Error<<"Exiting because communicator thread died with error: "<<ae.reason<<endl;
 155     Utility::sleep(1);
 156     _exit(1);
 157   }
 158   catch(std::exception &e) {
 159     g_log<<Logger::Error<<"Exiting because communicator thread died with STL error: "<<e.what()<<endl;
 160     _exit(1);
 161   }
 162   catch( ... )
 163   {
 164     g_log << Logger::Error << "Exiting because communicator caught unknown exception." << endl;
 165     _exit(1);
 166   }
 167 }
 168