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