pdns/common_startup.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 "common_startup.hh"
  26 #include "ws-auth.hh"
  27 #include "secpoll-auth.hh"
  28 #include <sys/time.h>
  29 #include <sys/resource.h>
  30 #include "dynhandler.hh"
  31 #include "dnsseckeeper.hh"
  32 #include "threadname.hh"
  33 #include "misc.hh"
  34
  35 #include <thread>
  36
  37 #ifdef HAVE_SYSTEMD
  38 #include <systemd/sd-daemon.h>
  39 #endif
  40
  41 bool g_anyToTcp;
  42 bool g_8bitDNS;
  43 #ifdef HAVE_LUA_RECORDS
  44 bool g_doLuaRecord;
  45 int g_luaRecordExecLimit;
  46 #endif
  47 typedef Distributor<DNSPacket,DNSPacket,PacketHandler> DNSDistributor;
  48
  49 ArgvMap theArg;
  50 StatBag S;  //!< Statistics are gathered across PDNS via the StatBag class S
  51 AuthPacketCache PC; //!< This is the main PacketCache, shared across all threads
  52 AuthQueryCache QC;
  53 std::unique_ptr<DNSProxy> DP{nullptr};
  54 std::unique_ptr<DynListener> dl{nullptr};
  55 CommunicatorClass Communicator;
  56 shared_ptr<UDPNameserver> N;
  57 int avg_latency;
  58 unique_ptr<TCPNameserver> TN;
  59 static vector<DNSDistributor*> g_distributors;
  60 vector<std::shared_ptr<UDPNameserver> > g_udpReceivers;
  61
  62 ArgvMap &arg()
  63 {
  64   return theArg;
  65 }
  66
  67 void declareArguments()
  68 {
  69   ::arg().set("config-dir","Location of configuration directory (pdns.conf)")=SYSCONFDIR;
  70   ::arg().set("config-name","Name of this virtual configuration - will rename the binary image")="";
  71   ::arg().set("socket-dir",string("Where the controlsocket will live, ")+LOCALSTATEDIR+"/pdns when unset and not chrooted" )="";
  72   ::arg().set("module-dir","Default directory for modules")=PKGLIBDIR;
  73   ::arg().set("chroot","If set, chroot to this directory for more security")="";
  74   ::arg().set("logging-facility","Log under a specific facility")="";
  75   ::arg().set("daemon","Operate as a daemon")="no";
  76
  77   ::arg().set("local-port","The port on which we listen")="53";
  78   ::arg().setSwitch("dnsupdate","Enable/Disable DNS update (RFC2136) support. Default is no.")="no";
  79   ::arg().setSwitch("write-pid","Write a PID file")="yes";
  80   ::arg().set("allow-dnsupdate-from","A global setting to allow DNS updates from these IP ranges.")="127.0.0.0/8,::1";
  81   ::arg().setSwitch("send-signed-notify","Send TSIG secured NOTIFY if TSIG key is configured for a domain")="yes";
  82   ::arg().set("allow-unsigned-notify","Allow unsigned notifications for TSIG secured domains")="yes"; //FIXME: change to 'no' later
  83   ::arg().set("allow-unsigned-supermaster", "Allow supermasters to create zones without TSIG signed NOTIFY")="yes";
  84   ::arg().setSwitch("forward-dnsupdate","A global setting to allow DNS update packages that are for a Slave domain, to be forwarded to the master.")="yes";
  85   ::arg().setSwitch("log-dns-details","If PDNS should log DNS non-erroneous details")="no";
  86   ::arg().setSwitch("log-dns-queries","If PDNS should log all incoming DNS queries")="no";
  87   ::arg().set("local-address","Local IP addresses to which we bind")="0.0.0.0";
  88   ::arg().setSwitch("local-address-nonexist-fail","Fail to start if one or more of the local-address's do not exist on this server")="yes";
  89   ::arg().setSwitch("non-local-bind", "Enable binding to non-local addresses by using FREEBIND / BINDANY socket options")="no";
  90   ::arg().set("local-ipv6","Local IP address to which we bind")="::";
  91   ::arg().setSwitch("reuseport","Enable higher performance on compliant kernels by using SO_REUSEPORT allowing each receiver thread to open its own socket")="no";
  92   ::arg().setSwitch("local-ipv6-nonexist-fail","Fail to start if one or more of the local-ipv6 addresses do not exist on this server")="yes";
  93   ::arg().set("query-local-address","Source IP address for sending queries")="0.0.0.0";
  94   ::arg().set("query-local-address6","Source IPv6 address for sending queries")="::";
  95   ::arg().set("overload-queue-length","Maximum queuelength moving to packetcache only")="0";
  96   ::arg().set("max-queue-length","Maximum queuelength before considering situation lost")="5000";
  97
  98   ::arg().set("retrieval-threads", "Number of AXFR-retrieval threads for slave operation")="2";
  99   ::arg().setSwitch("api", "Enable/disable the REST API (including HTTP listener)")="no";
 100   ::arg().set("api-key", "Static pre-shared authentication key for access to the REST API")="";
 101   ::arg().setSwitch("default-api-rectify","Default API-RECTIFY value for zones")="yes";
 102   ::arg().setSwitch("dname-processing", "If we should support DNAME records")="no";
 103
 104   ::arg().setCmd("help","Provide a helpful message");
 105   ::arg().setCmd("version","Output version and compilation date");
 106   ::arg().setCmd("config","Provide configuration file on standard output");
 107   ::arg().setCmd("list-modules","Lists all modules available");
 108   ::arg().setCmd("no-config","Don't parse configuration file");
 109
 110   ::arg().set("version-string","PowerDNS version in packets - full, anonymous, powerdns or custom")="full";
 111   ::arg().set("control-console","Debugging switch - don't use")="no"; // but I know you will!
 112   ::arg().set("loglevel","Amount of logging. Higher is more. Do not set below 3")="4";
 113   ::arg().set("disable-syslog","Disable logging to syslog, useful when running inside a supervisor that logs stdout")="no";
 114   ::arg().set("log-timestamp","Print timestamps in log lines")="yes";
 115   ::arg().set("default-soa-name","name to insert in the SOA record if none set in the backend")="a.misconfigured.powerdns.server";
 116   ::arg().set("default-soa-mail","mail address to insert in the SOA record if none set in the backend")="";
 117   ::arg().set("distributor-threads","Default number of Distributor (backend) threads to start")="3";
 118   ::arg().set("signing-threads","Default number of signer threads to start")="3";
 119   ::arg().set("receiver-threads","Default number of receiver threads to start")="1";
 120   ::arg().set("queue-limit","Maximum number of milliseconds to queue a query")="1500";
 121   ::arg().set("resolver","Use this resolver for ALIAS and the internal stub resolver")="no";
 122   ::arg().set("udp-truncation-threshold", "Maximum UDP response size before we truncate")="1232";
 123
 124   ::arg().set("config-name","Name of this virtual configuration - will rename the binary image")="";
 125
 126   ::arg().set("load-modules","Load this module - supply absolute or relative path")="";
 127   ::arg().set("launch","Which backends to launch and order to query them in")="";
 128   ::arg().setSwitch("disable-axfr","Disable zonetransfers but do allow TCP queries")="no";
 129   ::arg().set("allow-axfr-ips","Allow zonetransfers only to these subnets")="127.0.0.0/8,::1";
 130   ::arg().set("only-notify", "Only send AXFR NOTIFY to these IP addresses or netmasks")="0.0.0.0/0,::/0";
 131   ::arg().set("also-notify", "When notifying a domain, also notify these nameservers")="";
 132   ::arg().set("allow-notify-from","Allow AXFR NOTIFY from these IP ranges. If empty, drop all incoming notifies.")="0.0.0.0/0,::/0";
 133   ::arg().set("slave-cycle-interval","Schedule slave freshness checks once every .. seconds")="60";
 134
 135   ::arg().set("tcp-control-address","If set, PowerDNS can be controlled over TCP on this address")="";
 136   ::arg().set("tcp-control-port","If set, PowerDNS can be controlled over TCP on this address")="53000";
 137   ::arg().set("tcp-control-secret","If set, PowerDNS can be controlled over TCP after passing this secret")="";
 138   ::arg().set("tcp-control-range","If set, remote control of PowerDNS is possible over these networks only")="127.0.0.0/8, 10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12, ::1/128, fe80::/10";
 139
 140   ::arg().setSwitch("slave","Act as a slave")="no";
 141   ::arg().setSwitch("master","Act as a master")="no";
 142   ::arg().setSwitch("superslave", "Act as a superslave")="no";
 143   ::arg().setSwitch("disable-axfr-rectify","Disable the rectify step during an outgoing AXFR. Only required for regression testing.")="no";
 144   ::arg().setSwitch("guardian","Run within a guardian process")="no";
 145   ::arg().setSwitch("prevent-self-notification","Don't send notifications to what we think is ourself")="yes";
 146   ::arg().setSwitch("any-to-tcp","Answer ANY queries with tc=1, shunting to TCP")="yes";
 147   ::arg().setSwitch("edns-subnet-processing","If we should act on EDNS Subnet options")="no";
 148
 149   ::arg().setSwitch("webserver","Start a webserver for monitoring (api=yes also enables the HTTP listener)")="no";
 150   ::arg().setSwitch("webserver-print-arguments","If the webserver should print arguments")="no";
 151   ::arg().set("webserver-address","IP Address of webserver/API to listen on")="127.0.0.1";
 152   ::arg().set("webserver-port","Port of webserver/API to listen on")="8081";
 153   ::arg().set("webserver-password","Password required for accessing the webserver")="";
 154   ::arg().set("webserver-allow-from","Webserver/API access is only allowed from these subnets")="127.0.0.1,::1";
 155   ::arg().set("webserver-loglevel", "Amount of logging in the webserver (none, normal, detailed)") = "normal";
 156   ::arg().set("webserver-max-bodysize","Webserver/API maximum request/response body size in megabytes")="2";
 157
 158   ::arg().setSwitch("do-ipv6-additional-processing", "Do AAAA additional processing")="yes";
 159   ::arg().setSwitch("query-logging","Hint backends that queries should be logged")="no";
 160
 161   ::arg().set("carbon-namespace", "If set overwrites the first part of the carbon string")="pdns";
 162   ::arg().set("carbon-ourname", "If set, overrides our reported hostname for carbon stats")="";
 163   ::arg().set("carbon-instance", "If set overwrites the the instance name default")="auth";
 164   ::arg().set("carbon-server", "If set, send metrics in carbon (graphite) format to this server IP address")="";
 165   ::arg().set("carbon-interval", "Number of seconds between carbon (graphite) updates")="30";
 166
 167   ::arg().set("cache-ttl","Seconds to store packets in the PacketCache")="20";
 168   ::arg().set("negquery-cache-ttl","Seconds to store negative query results in the QueryCache")="60";
 169   ::arg().set("query-cache-ttl","Seconds to store query results in the QueryCache")="20";
 170   ::arg().set("soa-minimum-ttl","Default SOA minimum ttl")="3600";
 171   ::arg().set("server-id", "Returned when queried for 'id.server' TXT or NSID, defaults to hostname - disabled or custom")="";
 172   ::arg().set("soa-refresh-default","Default SOA refresh")="10800";
 173   ::arg().set("soa-retry-default","Default SOA retry")="3600";
 174   ::arg().set("soa-expire-default","Default SOA expire")="604800";
 175   ::arg().set("default-soa-edit","Default SOA-EDIT value")="";
 176   ::arg().set("default-soa-edit-signed","Default SOA-EDIT value for signed zones")="";
 177   ::arg().set("dnssec-key-cache-ttl","Seconds to cache DNSSEC keys from the database")="30";
 178   ::arg().set("domain-metadata-cache-ttl","Seconds to cache domain metadata from the database")="60";
 179
 180   ::arg().set("trusted-notification-proxy", "IP address of incoming notification proxy")="";
 181   ::arg().set("slave-renotify", "If we should send out notifications for slaved updates")="no";
 182   ::arg().set("forward-notify", "IP addresses to forward received notifications to regardless of master or slave settings")="";
 183
 184   ::arg().set("default-ttl","Seconds a result is valid if not set otherwise")="3600";
 185   ::arg().set("max-tcp-connections","Maximum number of TCP connections")="20";
 186   ::arg().set("max-tcp-connections-per-client","Maximum number of simultaneous TCP connections per client")="0";
 187   ::arg().set("max-tcp-transactions-per-conn","Maximum number of subsequent queries per TCP connection")="0";
 188   ::arg().set("max-tcp-connection-duration","Maximum time in seconds that a TCP DNS connection is allowed to stay open.")="0";
 189   ::arg().set("tcp-idle-timeout","Maximum time in seconds that a TCP DNS connection is allowed to stay open while being idle")="5";
 190
 191   ::arg().setSwitch("no-shuffle","Set this to prevent random shuffling of answers - for regression testing")="off";
 192
 193   ::arg().set("setuid","If set, change user id to this uid for more security")="";
 194   ::arg().set("setgid","If set, change group id to this gid for more security")="";
 195
 196   ::arg().set("max-cache-entries", "Maximum number of entries in the query cache")="1000000";
 197   ::arg().set("max-packet-cache-entries", "Maximum number of entries in the packet cache")="1000000";
 198   ::arg().set("max-signature-cache-entries", "Maximum number of signatures cache entries")="";
 199   ::arg().set("max-ent-entries", "Maximum number of empty non-terminals in a zone")="100000";
 200   ::arg().set("entropy-source", "If set, read entropy from this file")="/dev/urandom";
 201
 202   ::arg().set("lua-prequery-script", "Lua script with prequery handler (DO NOT USE)")="";
 203   ::arg().set("lua-dnsupdate-policy-script", "Lua script with DNS update policy handler")="";
 204
 205   ::arg().setSwitch("traceback-handler","Enable the traceback handler (Linux only)")="yes";
 206   ::arg().setSwitch("direct-dnskey","Fetch DNSKEY, CDS and CDNSKEY RRs from backend during DNSKEY or CDS/CDNSKEY synthesis")="no";
 207   ::arg().set("default-ksk-algorithm","Default KSK algorithm")="ecdsa256";
 208   ::arg().set("default-ksk-size","Default KSK size (0 means default)")="0";
 209   ::arg().set("default-zsk-algorithm","Default ZSK algorithm")="";
 210   ::arg().set("default-zsk-size","Default ZSK size (0 means default)")="0";
 211   ::arg().set("max-nsec3-iterations","Limit the number of NSEC3 hash iterations")="500"; // RFC5155 10.3
 212
 213   ::arg().set("include-dir","Include *.conf files from this directory");
 214   ::arg().set("security-poll-suffix","Domain name from which to query security update notifications")="secpoll.powerdns.com.";
 215
 216   ::arg().setSwitch("expand-alias", "Expand ALIAS records")="no";
 217   ::arg().setSwitch("outgoing-axfr-expand-alias", "Expand ALIAS records during outgoing AXFR")="no";
 218   ::arg().setSwitch("8bit-dns", "Allow 8bit dns queries")="no";
 219 #ifdef HAVE_LUA_RECORDS
 220   ::arg().setSwitch("enable-lua-records", "Process LUA records for all zones (metadata overrides this)")="no";
 221   ::arg().set("lua-records-exec-limit", "LUA records scripts execution limit (instructions count). Values <= 0 mean no limit")="1000";
 222 #endif
 223   ::arg().setSwitch("axfr-lower-serial", "Also AXFR a zone from a master with a lower serial")="no";
 224
 225   ::arg().set("lua-axfr-script", "Script to be used to edit incoming AXFRs")="";
 226   ::arg().set("xfr-max-received-mbytes", "Maximum number of megabytes received from an incoming XFR")="100";
 227   ::arg().set("axfr-fetch-timeout", "Maximum time in seconds for inbound AXFR to start or be idle after starting")="10";
 228
 229   ::arg().set("tcp-fast-open", "Enable TCP Fast Open support on the listening sockets, using the supplied numerical value as the queue size")="0";
 230
 231   ::arg().set("max-generate-steps", "Maximum number of $GENERATE steps when loading a zone from a file")="0";
 232
 233   ::arg().set("rng", "Specify the random number generator to use. Valid values are auto,sodium,openssl,getrandom,arc4random,urandom.")="auto";
 234 }
 235
 236 static time_t s_start=time(0);
 237 static uint64_t uptimeOfProcess(const std::string& str)
 238 {
 239   return time(0) - s_start;
 240 }
 241
 242 static uint64_t getSysUserTimeMsec(const std::string& str)
 243 {
 244   struct rusage ru;
 245   getrusage(RUSAGE_SELF, &ru);
 246
 247   if(str=="sys-msec") {
 248     return (ru.ru_stime.tv_sec*1000ULL + ru.ru_stime.tv_usec/1000);
 249   }
 250   else
 251     return (ru.ru_utime.tv_sec*1000ULL + ru.ru_utime.tv_usec/1000);
 252
 253 }
 254
 255 static uint64_t getTCPConnectionCount(const std::string& str)
 256 {
 257   return TN->numTCPConnections();
 258 }
 259
 260 static uint64_t getQCount(const std::string& str)
 261 try
 262 {
 263   int totcount=0;
 264   for(const auto& d : g_distributors) {
 265     if(!d)
 266       continue;
 267     totcount += d->getQueueSize();  // this does locking and other things, so don't get smart
 268   }
 269   return totcount;
 270 }
 271 catch(std::exception& e)
 272 {
 273   g_log<<Logger::Error<<"Had error retrieving queue sizes: "<<e.what()<<endl;
 274   return 0;
 275 }
 276 catch(PDNSException& e)
 277 {
 278   g_log<<Logger::Error<<"Had error retrieving queue sizes: "<<e.reason<<endl;
 279   return 0;
 280 }
 281
 282 static uint64_t getLatency(const std::string& str)
 283 {
 284   return avg_latency;
 285 }
 286
 287 void declareStats(void)
 288 {
 289   S.declare("udp-queries","Number of UDP queries received");
 290   S.declare("udp-do-queries","Number of UDP queries received with DO bit");
 291   S.declare("udp-answers","Number of answers sent out over UDP");
 292   S.declare("udp-answers-bytes","Total size of answers sent out over UDP");
 293   S.declare("udp4-answers-bytes","Total size of answers sent out over UDPv4");
 294   S.declare("udp6-answers-bytes","Total size of answers sent out over UDPv6");
 295
 296   S.declare("udp4-answers","Number of IPv4 answers sent out over UDP");
 297   S.declare("udp4-queries","Number of IPv4 UDP queries received");
 298   S.declare("udp6-answers","Number of IPv6 answers sent out over UDP");
 299   S.declare("udp6-queries","Number of IPv6 UDP queries received");
 300   S.declare("overload-drops","Queries dropped because backends overloaded");
 301
 302   S.declare("rd-queries", "Number of recursion desired questions");
 303   S.declare("recursion-unanswered", "Number of packets unanswered by configured recursor");
 304   S.declare("recursing-answers","Number of recursive answers sent out");
 305   S.declare("recursing-questions","Number of questions sent to recursor");
 306   S.declare("corrupt-packets","Number of corrupt packets received");
 307   S.declare("signatures", "Number of DNSSEC signatures made");
 308   S.declare("tcp-queries","Number of TCP queries received");
 309   S.declare("tcp-answers","Number of answers sent out over TCP");
 310   S.declare("tcp-answers-bytes","Total size of answers sent out over TCP");
 311   S.declare("tcp4-answers-bytes","Total size of answers sent out over TCPv4");
 312   S.declare("tcp6-answers-bytes","Total size of answers sent out over TCPv6");
 313
 314   S.declare("tcp4-queries","Number of IPv4 TCP queries received");
 315   S.declare("tcp4-answers","Number of IPv4 answers sent out over TCP");
 316
 317   S.declare("tcp6-queries","Number of IPv6 TCP queries received");
 318   S.declare("tcp6-answers","Number of IPv6 answers sent out over TCP");
 319
 320   S.declare("open-tcp-connections","Number of currently open TCP connections", getTCPConnectionCount);;
 321
 322   S.declare("qsize-q","Number of questions waiting for database attention", getQCount);
 323
 324   S.declare("dnsupdate-queries", "DNS update packets received.");
 325   S.declare("dnsupdate-answers", "DNS update packets successfully answered.");
 326   S.declare("dnsupdate-refused", "DNS update packets that are refused.");
 327   S.declare("dnsupdate-changes", "DNS update changes to records in total.");
 328
 329   S.declare("incoming-notifications", "NOTIFY packets received.");
 330
 331   S.declare("uptime", "Uptime of process in seconds", uptimeOfProcess);
 332   S.declare("real-memory-usage", "Actual unique use of memory in bytes (approx)", getRealMemoryUsage);
 333   S.declare("special-memory-usage", "Actual unique use of memory in bytes (approx)", getSpecialMemoryUsage);
 334   S.declare("fd-usage", "Number of open filedescriptors", getOpenFileDescriptors);
 335 #ifdef __linux__
 336   S.declare("udp-recvbuf-errors", "UDP 'recvbuf' errors", udpErrorStats);
 337   S.declare("udp-sndbuf-errors", "UDP 'sndbuf' errors", udpErrorStats);
 338   S.declare("udp-noport-errors", "UDP 'noport' errors", udpErrorStats);
 339   S.declare("udp-in-errors", "UDP 'in' errors", udpErrorStats);
 340 #endif
 341
 342   S.declare("sys-msec", "Number of msec spent in system time", getSysUserTimeMsec);
 343   S.declare("user-msec", "Number of msec spent in user time", getSysUserTimeMsec);
 344   S.declare("meta-cache-size", "Number of entries in the metadata cache", DNSSECKeeper::dbdnssecCacheSizes);
 345   S.declare("key-cache-size", "Number of entries in the key cache", DNSSECKeeper::dbdnssecCacheSizes);
 346   S.declare("signature-cache-size", "Number of entries in the signature cache", signatureCacheSize);
 347
 348   S.declare("servfail-packets","Number of times a server-failed packet was sent out");
 349   S.declare("latency","Average number of microseconds needed to answer a question", getLatency);
 350   S.declare("timedout-packets","Number of packets which weren't answered within timeout set");
 351   S.declare("security-status", "Security status based on regular polling");
 352   S.declareDNSNameQTypeRing("queries","UDP Queries Received");
 353   S.declareDNSNameQTypeRing("nxdomain-queries","Queries for non-existent records within existent domains");
 354   S.declareDNSNameQTypeRing("noerror-queries","Queries for existing records, but for type we don't have");
 355   S.declareDNSNameQTypeRing("servfail-queries","Queries that could not be answered due to backend errors");
 356   S.declareDNSNameQTypeRing("unauth-queries","Queries for domains that we are not authoritative for");
 357   S.declareRing("logmessages","Log Messages");
 358   S.declareComboRing("remotes","Remote server IP addresses");
 359   S.declareComboRing("remotes-unauth","Remote hosts querying domains for which we are not auth");
 360   S.declareComboRing("remotes-corrupt","Remote hosts sending corrupt packets");
 361 }
 362
 363 int isGuarded(char **argv)
 364 {
 365   char *p=strstr(argv[0],"-instance");
 366
 367   return !!p;
 368 }
 369
 370 static void sendout(std::unique_ptr<DNSPacket>& a)
 371 {
 372   if(!a)
 373     return;
 374
 375   N->send(*a);
 376
 377   int diff=a->d_dt.udiff();
 378   avg_latency=(int)(0.999*avg_latency+0.001*diff);
 379 }
 380
 381 //! The qthread receives questions over the internet via the Nameserver class, and hands them to the Distributor for further processing
 382 static void qthread(unsigned int num)
 383 try
 384 {
 385   setThreadName("pdns/receiver");
 386
 387   g_distributors[num] = DNSDistributor::Create(::arg().asNum("distributor-threads", 1));
 388   DNSDistributor* distributor = g_distributors[num]; // the big dispatcher!
 389   DNSPacket question(true);
 390   DNSPacket cached(false);
 391
 392   AtomicCounter &numreceived=*S.getPointer("udp-queries");
 393   AtomicCounter &numreceiveddo=*S.getPointer("udp-do-queries");
 394
 395   AtomicCounter &numreceived4=*S.getPointer("udp4-queries");
 396
 397   AtomicCounter &numreceived6=*S.getPointer("udp6-queries");
 398   AtomicCounter &overloadDrops=*S.getPointer("overload-drops");
 399
 400   int diff;
 401   bool logDNSQueries = ::arg().mustDo("log-dns-queries");
 402   shared_ptr<UDPNameserver> NS;
 403   std::string buffer;
 404   buffer.resize(DNSPacket::s_udpTruncationThreshold);
 405
 406   // If we have SO_REUSEPORT then create a new port for all receiver threads
 407   // other than the first one.
 408   if(N->canReusePort() ) {
 409     NS = g_udpReceivers[num];
 410     if (NS == nullptr) {
 411       NS = N;
 412     }
 413   } else {
 414     NS = N;
 415   }
 416
 417   for(;;) {
 418     if(!NS->receive(question, buffer)) { // receive a packet         inline
 419       continue;                    // packet was broken, try again
 420     }
 421
 422     numreceived++;
 423
 424     if(question.d_remote.getSocklen()==sizeof(sockaddr_in))
 425       numreceived4++;
 426     else
 427       numreceived6++;
 428
 429     if(question.d_dnssecOk)
 430       numreceiveddo++;
 431
 432      if(question.d.qr)
 433        continue;
 434
 435     S.ringAccount("queries", question.qdomain, question.qtype);
 436     S.ringAccount("remotes", question.d_remote);
 437     if(logDNSQueries) {
 438       string remote;
 439       if(question.hasEDNSSubnet())
 440         remote = question.getRemote().toString() + "<-" + question.getRealRemote().toString();
 441       else
 442         remote = question.getRemote().toString();
 443       g_log << Logger::Notice<<"Remote "<< remote <<" wants '" << question.qdomain<<"|"<<question.qtype.getName() <<
 444         "', do = " <<question.d_dnssecOk <<", bufsize = "<< question.getMaxReplyLen();
 445       if(question.d_ednsRawPacketSizeLimit > 0 && question.getMaxReplyLen() != (unsigned int)question.d_ednsRawPacketSizeLimit)
 446         g_log<<" ("<<question.d_ednsRawPacketSizeLimit<<")";
 447       g_log<<": ";
 448     }
 449
 450     if(PC.enabled() && (question.d.opcode != Opcode::Notify && question.d.opcode != Opcode::Update) && question.couldBeCached()) {
 451       bool haveSomething=PC.get(question, cached); // does the PacketCache recognize this question?
 452       if (haveSomething) {
 453         if(logDNSQueries)
 454           g_log<<"packetcache HIT"<<endl;
 455         cached.setRemote(&question.d_remote);  // inlined
 456         cached.setSocket(question.getSocket());                               // inlined
 457         cached.d_anyLocal = question.d_anyLocal;
 458         cached.setMaxReplyLen(question.getMaxReplyLen());
 459         cached.d.rd=question.d.rd; // copy in recursion desired bit
 460         cached.d.id=question.d.id;
 461         cached.commitD(); // commit d to the packet                        inlined
 462         NS->send(cached); // answer it then                              inlined
 463         diff=question.d_dt.udiff();
 464         avg_latency=(int)(0.999*avg_latency+0.001*diff); // 'EWMA'
 465         continue;
 466       }
 467     }
 468
 469     if(distributor->isOverloaded()) {
 470       if(logDNSQueries)
 471         g_log<<"Dropped query, backends are overloaded"<<endl;
 472       overloadDrops++;
 473       continue;
 474     }
 475
 476     if(PC.enabled() && logDNSQueries)
 477       g_log<<"packetcache MISS"<<endl;
 478
 479     try {
 480       distributor->question(question, &sendout); // otherwise, give to the distributor
 481     }
 482     catch(DistributorFatal& df) { // when this happens, we have leaked loads of memory. Bailing out time.
 483       _exit(1);
 484     }
 485   }
 486 }
 487 catch(PDNSException& pe)
 488 {
 489   g_log<<Logger::Error<<"Fatal error in question thread: "<<pe.reason<<endl;
 490   _exit(1);
 491 }
 492
 493 static void* dummyThread(void *)
 494 {
 495   void* ignore=0;
 496   pthread_exit(ignore);
 497 }
 498
 499 static void triggerLoadOfLibraries()
 500 {
 501   pthread_t tid;
 502   pthread_create(&tid, 0, dummyThread, 0);
 503   void* res;
 504   pthread_join(tid, &res);
 505 }
 506
 507 void mainthread()
 508 {
 509    Utility::srandom();
 510
 511    gid_t newgid = 0;
 512    if(!::arg()["setgid"].empty())
 513      newgid = strToGID(::arg()["setgid"]);
 514    uid_t newuid = 0;
 515    if(!::arg()["setuid"].empty())
 516      newuid = strToUID(::arg()["setuid"]);
 517
 518    g_anyToTcp = ::arg().mustDo("any-to-tcp");
 519    g_8bitDNS = ::arg().mustDo("8bit-dns");
 520 #ifdef HAVE_LUA_RECORDS
 521    g_doLuaRecord = ::arg().mustDo("enable-lua-records");
 522    g_LuaRecordSharedState = (::arg()["enable-lua-records"] == "shared");
 523    g_luaRecordExecLimit = ::arg().asNum("lua-records-exec-limit");
 524 #endif
 525
 526    DNSPacket::s_udpTruncationThreshold = std::max(512, ::arg().asNum("udp-truncation-threshold"));
 527    DNSPacket::s_doEDNSSubnetProcessing = ::arg().mustDo("edns-subnet-processing");
 528
 529    PC.setTTL(::arg().asNum("cache-ttl"));
 530    PC.setMaxEntries(::arg().asNum("max-packet-cache-entries"));
 531    QC.setMaxEntries(::arg().asNum("max-cache-entries"));
 532
 533    stubParseResolveConf();
 534
 535    if(!::arg()["chroot"].empty()) {
 536 #ifdef HAVE_SYSTEMD
 537      char *ns;
 538      ns = getenv("NOTIFY_SOCKET");
 539      if (ns != nullptr) {
 540        g_log<<Logger::Error<<"Unable to chroot when running from systemd. Please disable chroot= or set the 'Type' for this service to 'simple'"<<endl;
 541        exit(1);
 542      }
 543 #endif
 544      triggerLoadOfLibraries();
 545      if(::arg().mustDo("master") || ::arg().mustDo("slave"))
 546         gethostbyname("a.root-servers.net"); // this forces all lookup libraries to be loaded
 547      Utility::dropGroupPrivs(newuid, newgid);
 548      if(chroot(::arg()["chroot"].c_str())<0 || chdir("/")<0) {
 549        g_log<<Logger::Error<<"Unable to chroot to '"+::arg()["chroot"]+"': "<<stringerror()<<", exiting"<<endl;
 550        exit(1);
 551      }
 552      else
 553        g_log<<Logger::Error<<"Chrooted to '"<<::arg()["chroot"]<<"'"<<endl;
 554    } else {
 555      Utility::dropGroupPrivs(newuid, newgid);
 556    }
 557
 558   AuthWebServer webserver;
 559   Utility::dropUserPrivs(newuid);
 560
 561   if(::arg().mustDo("resolver")){
 562     DP=std::unique_ptr<DNSProxy>(new DNSProxy(::arg()["resolver"]));
 563     DP->go();
 564   }
 565
 566   try {
 567     doSecPoll(true);
 568   }
 569   catch(...) {}
 570
 571   {
 572     // Some sanity checking on default key settings
 573     bool hadKeyError = false;
 574     int kskAlgo{0}, zskAlgo{0};
 575     for (const string& algotype : {"ksk", "zsk"}) {
 576       int algo, size;
 577       if (::arg()["default-"+algotype+"-algorithm"].empty())
 578         continue;
 579       algo = DNSSECKeeper::shorthand2algorithm(::arg()["default-"+algotype+"-algorithm"]);
 580       size = ::arg().asNum("default-"+algotype+"-size");
 581       if (algo == -1) {
 582         g_log<<Logger::Error<<"Error: default-"<<algotype<<"-algorithm set to unknown algorithm: "<<::arg()["default-"+algotype+"-algorithm"]<<endl;
 583         hadKeyError = true;
 584       }
 585       else if (algo <= 10 && size == 0) {
 586         g_log<<Logger::Error<<"Error: default-"<<algotype<<"-algorithm is set to an algorithm ("<<::arg()["default-"+algotype+"-algorithm"]<<") that requires a non-zero default-"<<algotype<<"-size!"<<endl;
 587         hadKeyError = true;
 588       }
 589       if (algotype == "ksk") {
 590         kskAlgo = algo;
 591       } else {
 592         zskAlgo = algo;
 593       }
 594     }
 595     if (hadKeyError) {
 596       exit(1);
 597     }
 598     if (kskAlgo == 0 && zskAlgo != 0) {
 599       g_log<<Logger::Error<<"Error: default-zsk-algorithm is set, but default-ksk-algorithm is not set."<<endl;
 600       exit(1);
 601     }
 602     if (zskAlgo != 0 && zskAlgo != kskAlgo) {
 603       g_log<<Logger::Error<<"Error: default-zsk-algorithm ("<<::arg()["default-zsk-algorithm"]<<"), when set, can not be different from default-ksk-algorithm ("<<::arg()["default-ksk-algorithm"]<<")."<<endl;
 604       exit(1);
 605     }
 606   }
 607
 608   // NOW SAFE TO CREATE THREADS!
 609   dl->go();
 610
 611   if(::arg().mustDo("webserver") || ::arg().mustDo("api"))
 612     webserver.go();
 613
 614   if(::arg().mustDo("slave") || ::arg().mustDo("master") || !::arg()["forward-notify"].empty())
 615     Communicator.go();
 616
 617   TN->go(); // tcp nameserver launch
 618
 619   unsigned int max_rthreads= ::arg().asNum("receiver-threads", 1);
 620   g_distributors.resize(max_rthreads);
 621   for(unsigned int n=0; n < max_rthreads; ++n) {
 622     std::thread t(qthread, n);
 623     t.detach();
 624   }
 625
 626   std::thread carbonThread(carbonDumpThread); // runs even w/o carbon, might change @ runtime
 627
 628 #ifdef HAVE_SYSTEMD
 629   /* If we are here, notify systemd that we are ay-ok! This might have some
 630    * timing issues with the backend-threads. e.g. if the initial MySQL connection
 631    * is slow and times out (leading to process termination through the backend)
 632    * We probably have told systemd already that we have started correctly.
 633    */
 634     sd_notify(0, "READY=1");
 635 #endif
 636
 637   for(;;) {
 638     sleep(1800);
 639     try {
 640       doSecPoll(false);
 641     }
 642     catch(...){}
 643   }
 644
 645   g_log<<Logger::Error<<"Mainthread exiting - should never happen"<<endl;
 646 }