pdns/common_startup.cc

   1 /*
   2     PowerDNS Versatile Database Driven Nameserver
   3     Copyright (C) 2002  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 as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 */
  19 #include "common_startup.hh"
  20
  21 typedef Distributor<DNSPacket,DNSPacket,PacketHandler> DNSDistributor;
  22
  23
  24 ArgvMap theArg;
  25 StatBag S;  //!< Statistics are gathered accross PDNS via the StatBag class S
  26 PacketCache PC; //!< This is the main PacketCache, shared accross all threads
  27 DNSProxy *DP;
  28 DynListener *dl;
  29 CommunicatorClass Communicator;
  30 UDPNameserver *N;
  31 int avg_latency;
  32 TCPNameserver *TN;
  33
  34 ArgvMap &arg()
  35 {
  36   return theArg;
  37 }
  38
  39
  40 void declareArguments()
  41 {
  42   arg().set("local-port","The port on which we listen")="53";
  43   arg().setSwitch("log-failed-updates","If PDNS should log failed update requests")="";
  44   arg().setSwitch("log-dns-details","If PDNS should log failed update requests")="";
  45   arg().set("urlredirector","Where we send hosts to that need to be url redirected")="127.0.0.1";
  46   arg().set("smtpredirector","Our smtpredir MX host")="a.misconfigured.powerdns.smtp.server";
  47   arg().set("local-address","Local IP address to which we bind")="0.0.0.0";
  48   arg().set("local-ipv6","Local IP address to which we bind")="";
  49   arg().set("max-queue-length","Maximum queuelength before considering situation lost")="5000";
  50   arg().set("soa-serial-offset","Make sure that no SOA serial is less than this number")="0";
  51   arg().set("only-soa","Make sure that no SOA serial is less than this number")="org";
  52   arg().setCmd("help","Provide a helpful message");
  53   arg().setCmd("config","Provide a helpful message");
  54   arg().setCmd("list-modules","Lists all modules available");
  55   arg().setCmd("no-config","Don't parse configuration file");
  56
  57   arg().set("control-console","Debugging switch - don't use")="no"; // but I know you will!
  58   arg().set("fancy-records","Process URL and MBOXFW records")="no";
  59   arg().set("wildcard-url","Process URL and MBOXFW records")="no";
  60   arg().set("wildcards","Honor wildcards in the database")="";
  61   arg().set("loglevel","Amount of logging. Higher is more. Do not set below 3")="4";
  62   arg().set("default-soa-name","name to insert in the SOA record if none set in the backend")="a.misconfigured.powerdns.server";
  63   arg().set("distributor-threads","Default number of Distributor (backend) threads to start")="3";
  64   arg().set("queue-limit","Maximum number of milliseconds to queue a query")="1500";
  65   arg().set("recursor","If recursion is desired, IP address of a recursing nameserver")="no";
  66   arg().set("lazy-recursion","Only recurse if question cannot be answered locally")="yes";
  67   arg().set("allow-recursion","List of netmasks that are allowed to recurse")="";
  68
  69   arg().set("disable-tcp","Do not listen to TCP queries")="no";
  70   arg().set("disable-axfr","Do not allow zone transfers")="no";
  71
  72   arg().set("config-name","Name of this virtual configuration - will rename the binary image")="";
  73
  74   arg().set("load-modules","Load this module - supply absolute or relative path")="";
  75   arg().set("launch","Which backends to launch and order to query them in")="";
  76   arg().setSwitch("disable-axfr","Disable zonetransfers but do allow TCP queries")="no";
  77   arg().set("allow-axfr-ips","If disabled, DO allow zonetransfers from these IP addresses")="";
  78   arg().set("slave-cycle-interval","Reschedule failed SOA serial checks once every .. seconds")="60";
  79
  80   arg().setSwitch("slave","Act as a slave")="no";
  81   arg().setSwitch("master","Act as a master")="no";
  82   arg().setSwitch("guardian","Run within a guardian process")="no";
  83   arg().setSwitch("skip-cname","Do not perform CNAME indirection for each query")="no";
  84   arg().setSwitch("strict-rfc-axfrs","Perform strictly rfc compliant axfrs (very slow)")="no";
  85
  86   arg().setSwitch("webserver","Start a webserver for monitoring")="no";
  87   arg().setSwitch("webserver-print-arguments","If the webserver should print arguments")="no";
  88   arg().set("webserver-address","IP Address of webserver to listen on")="127.0.0.1";
  89   arg().set("webserver-port","Port of webserver to listen on")="8081";
  90   arg().set("webserver-password","Password required for accessing the webserver")="";
  91
  92   arg().set("receiver-threads","Number of receiver threads to launch")="1";
  93
  94   arg().setSwitch("out-of-zone-additional-processing","Do out of zone additional processing")="no";
  95   arg().setSwitch("query-logging","Hint backends that queries should be logged")="no";
  96
  97   arg().set("cache-ttl","Seconds to store packets in the PacketCache")="20";
  98   arg().set("recursive-cache-ttl","Seconds to store packets in the PacketCache")="10";
  99   arg().set("negquery-cache-ttl","Seconds to store packets in the PacketCache")="60";
 100   arg().set("query-cache-ttl","Seconds to store packets in the PacketCache")="20";
 101   arg().set("soa-minimum-ttl","Default SOA mininum ttl")="3600";
 102   arg().set("max-tcp-connections","Maximum number of TCP connections")="10";
 103
 104   arg().setSwitch( "use-logfile", "Use a log file" )= "no";
 105   arg().set( "logfile", "Logfile to use" )= "pdns.log";
 106
 107 }
 108
 109
 110
 111 void declareStats(void)
 112 {
 113   S.declare("udp-queries","Number of UDP queries received");
 114   S.declare("udp-answers","Number of answers sent out over UDP");
 115   S.declare("recursing-answers","Number of recursive answers sent out");
 116   S.declare("recursing-questions","Number of questions sent to recursor");
 117   S.declare("corrupt-packets","Number of corrupt packets received");
 118
 119   S.declare("tcp-queries","Number of TCP queries received");
 120   S.declare("tcp-answers","Number of answers sent out over TCP");
 121
 122   S.declare("qsize-q","Number of questions waiting for database attention");
 123
 124   S.declare("deferred-cache-inserts","Amount of cache inserts that were deferred because of maintenance");
 125   S.declare("deferred-cache-lookup","Amount of cache lookups that were deferred because of maintenance");
 126
 127   S.declare("query-cache-hit","Number of hits on the query cache");
 128   S.declare("query-cache-miss","Number of misses on the query cache");
 129
 130
 131   S.declare("servfail-packets","Number of times a server-failed packet was sent out");
 132   S.declare("latency","Average number of microseconds needed to answer a question");
 133   S.declare("timedout-packets","Number of packets which weren't answered within timeout set");
 134
 135   S.declareRing("queries","UDP Queries Received");
 136   S.declareRing("nxdomain-queries","Queries for non-existent records within existent domains");
 137   S.declareRing("noerror-queries","Queries for existing records, but for type we don't have");
 138   S.declareRing("servfail-queries","Queries that could not be answered due to backend errors");
 139   S.declareRing("unauth-queries","Queries for domains that we are not authoritative for");
 140   S.declareRing("logmessages","Log Messages");
 141   S.declareRing("remotes","Remote server IP addresses");
 142   S.declareRing("remotes-unauth","Remote hosts querying domains for which we are not auth");
 143   S.declareRing("remotes-corrupt","Remote hosts sending corrupt packets");
 144
 145 }
 146
 147
 148 int isGuarded(char **argv)
 149 {
 150   char *p=strstr(argv[0],"-instance");
 151
 152   return !!p;
 153 }
 154
 155
 156 void sendout(const DNSDistributor::AnswerData &AD)
 157 {
 158   static int &numanswered=*S.getPointer("udp-answers");
 159   if(!AD.A)
 160     return;
 161
 162   N->send(AD.A);
 163   numanswered++;
 164   int diff=AD.A->d_dt.udiff();
 165   avg_latency=(int)(0.999*avg_latency+0.001*diff);
 166
 167   delete AD.A;
 168
 169
 170 }
 171
 172
 173 //! The qthread receives questions over the internet via the Nameserver class, and hands them to the Distributor for futher processing
 174 void *qthread(void *p)
 175 {
 176   DNSDistributor *D=static_cast<DNSDistributor *>(p);
 177
 178   DNSPacket *P;
 179
 180   DNSPacket question;
 181   DNSPacket cached;
 182
 183   int &numreceived=*S.getPointer("udp-queries");
 184   int &numanswered=*S.getPointer("udp-answers");
 185   numreceived=-1;
 186   int diff;
 187
 188   for(;;) {
 189     if(!((numreceived++)%50)) { // maintenance tasks
 190       S.set("latency",(int)avg_latency);
 191       int qcount, acount;
 192       D->getQueueSizes(qcount, acount);
 193       S.set("qsize-q",qcount);
 194     }
 195
 196     if(!(P=N->receive(&question))) { // receive a packet         inline
 197       continue;                    // packet was broken, try again
 198     }
 199
 200
 201     S.ringAccount("queries", P->qdomain+"/"+P->qtype.getName());
 202     S.ringAccount("remotes",P->getRemote());
 203
 204     if(PC.get(P,&cached)) { // short circuit - does the PacketCache recognize this question?
 205       cached.setRemote((struct sockaddr *)(P->remote),P->d_socklen);  // inlined
 206       cached.setSocket(P->getSocket());                               // inlined
 207       cached.spoofID(P->d.id);                                        // inlined
 208       cached.d.rd=P->d.rd; // copy in recursion desired bit
 209       cached.commitD(); // commit d to the packet                        inlined
 210
 211       N->send(&cached);   // answer it then                              inlined
 212       diff=P->d_dt.udiff();
 213       avg_latency=(int)(0.999*avg_latency+0.001*diff); // 'EWMA'
 214
 215       numanswered++;
 216       continue;
 217     }
 218
 219     D->question(P, &sendout); // otherwise, give to the distributor
 220   }
 221   return 0;
 222 }
 223
 224
 225 void mainthread()
 226 {
 227   Utility::srandom(time(0));
 228
 229    int newgid=0;
 230    if(!arg()["setgid"].empty())
 231      newgid=Utility::makeGidNumeric(arg()["setgid"]);
 232    int newuid=0;
 233    if(!arg()["setuid"].empty())
 234      newuid=Utility::makeUidNumeric(arg()["setuid"]);
 235    if(!arg()["chroot"].empty()) {
 236      if(chroot(arg()["chroot"].c_str())<0) {
 237        L<<Logger::Error<<"Unable to chroot: "<<strerror(errno)<<", exiting"<<endl;
 238        exit(1);
 239      }
 240      else
 241        L<<Logger::Error<<"Chrooted to '"<<arg()["chroot"]<<"'"<<endl;
 242    }
 243    Utility::dropPrivs(newuid, newgid);
 244
 245   if(arg().mustDo("recursor")){
 246     DP=new DNSProxy(arg()["recursor"]);
 247     DP->onlyFrom(arg()["allow-recursion"]);
 248     DP->go();
 249   }
 250   // NOW SAFE TO CREATE THREADS!
 251   dl->go();
 252
 253
 254
 255
 256   pthread_t qtid;
 257   StatWebServer sws;
 258
 259   if(arg()["webserver"]!="no")
 260     sws.go();
 261
 262   if(arg().mustDo("slave") || arg().mustDo("master"))
 263     Communicator.go();
 264
 265   if(TN)
 266     TN->go(); // tcp nameserver launch
 267
 268   //  fork(); (this worked :-))
 269   for(int n=0;n<arg().asNum("receiver-threads");++n) {
 270     DNSDistributor *D= new DNSDistributor(arg().asNum("distributor-threads")); // the big dispatcher!
 271     pthread_create(&qtid,0,qthread,static_cast<void *>(D)); // receives packets
 272   }
 273
 274   void *p;
 275   pthread_join(qtid, &p);
 276
 277   L<<Logger::Error<<"Mainthread exiting - should never happen"<<endl;
 278 }
 279
 280
 281
 282