pdns/dnsdist.hh

   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 #pragma once
  23 #include "config.h"
  24 #include "ext/luawrapper/include/LuaContext.hpp"
  25
  26 #include <atomic>
  27 #include <mutex>
  28 #include <string>
  29 #include <thread>
  30 #include <time.h>
  31 #include <unistd.h>
  32 #include <unordered_map>
  33
  34 #include <boost/circular_buffer.hpp>
  35 #include <boost/variant.hpp>
  36
  37 #include "bpf-filter.hh"
  38 #include "capabilities.hh"
  39 #include "dnscrypt.hh"
  40 #include "dnsdist-cache.hh"
  41 #include "dnsdist-dynbpf.hh"
  42 #include "dnsname.hh"
  43 #include "ednsoptions.hh"
  44 #include "gettime.hh"
  45 #include "iputils.hh"
  46 #include "misc.hh"
  47 #include "mplexer.hh"
  48 #include "sholder.hh"
  49 #include "tcpiohandler.hh"
  50 #include "uuid-utils.hh"
  51
  52 void carbonDumpThread();
  53 uint64_t uptimeOfProcess(const std::string& str);
  54
  55 extern uint16_t g_ECSSourcePrefixV4;
  56 extern uint16_t g_ECSSourcePrefixV6;
  57 extern bool g_ECSOverride;
  58
  59 typedef std::unordered_map<string, string> QTag;
  60
  61 struct DNSQuestion
  62 {
  63   DNSQuestion(const DNSName* name, uint16_t type, uint16_t class_, unsigned int consumed_, const ComboAddress* lc, const ComboAddress* rem, struct dnsheader* header, size_t bufferSize, uint16_t queryLen, bool isTcp, const struct timespec* queryTime_):
  64     qname(name), local(lc), remote(rem), dh(header), queryTime(queryTime_), size(bufferSize), consumed(consumed_), tempFailureTTL(boost::none), qtype(type), qclass(class_), len(queryLen), ecsPrefixLength(rem->sin4.sin_family == AF_INET ? g_ECSSourcePrefixV4 : g_ECSSourcePrefixV6), tcp(isTcp), ecsOverride(g_ECSOverride) {
  65     const uint16_t* flags = getFlagsFromDNSHeader(dh);
  66     origFlags = *flags;
  67   }
  68   DNSQuestion(const DNSQuestion&) = delete;
  69   DNSQuestion& operator=(const DNSQuestion&) = delete;
  70   DNSQuestion(DNSQuestion&&) = default;
  71
  72 #ifdef HAVE_PROTOBUF
  73   boost::optional<boost::uuids::uuid> uniqueId;
  74 #endif
  75   Netmask ecs;
  76   boost::optional<Netmask> subnet;
  77   const DNSName* qname{nullptr};
  78   const ComboAddress* local{nullptr};
  79   const ComboAddress* remote{nullptr};
  80   std::shared_ptr<QTag> qTag{nullptr};
  81   std::shared_ptr<std::map<uint16_t, EDNSOptionView> > ednsOptions;
  82   std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
  83   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
  84   struct dnsheader* dh{nullptr};
  85   const struct timespec* queryTime{nullptr};
  86   size_t size;
  87   unsigned int consumed{0};
  88   int delayMsec{0};
  89   boost::optional<uint32_t> tempFailureTTL;
  90   uint32_t cacheKeyNoECS;
  91   uint32_t cacheKey;
  92   const uint16_t qtype;
  93   const uint16_t qclass;
  94   uint16_t len;
  95   uint16_t ecsPrefixLength;
  96   uint16_t origFlags;
  97   uint8_t ednsRCode{0};
  98   const bool tcp;
  99   bool skipCache{false};
 100   bool ecsOverride;
 101   bool useECS{true};
 102   bool addXPF{true};
 103   bool ecsSet{false};
 104   bool ecsAdded{false};
 105   bool ednsAdded{false};
 106   bool useZeroScope{false};
 107   bool dnssecOK{false};
 108 };
 109
 110 struct DNSResponse : DNSQuestion
 111 {
 112   DNSResponse(const DNSName* name, uint16_t type, uint16_t class_, unsigned int consumed, const ComboAddress* lc, const ComboAddress* rem, struct dnsheader* header, size_t bufferSize, uint16_t responseLen, bool isTcp, const struct timespec* queryTime_):
 113     DNSQuestion(name, type, class_, consumed, lc, rem, header, bufferSize, responseLen, isTcp, queryTime_) { }
 114   DNSResponse(const DNSResponse&) = delete;
 115   DNSResponse& operator=(const DNSResponse&) = delete;
 116   DNSResponse(DNSResponse&&) = default;
 117 };
 118
 119 /* so what could you do:
 120    drop,
 121    fake up nxdomain,
 122    provide actual answer,
 123    allow & and stop processing,
 124    continue processing,
 125    modify header:    (servfail|refused|notimp), set TC=1,
 126    send to pool */
 127
 128 class DNSAction
 129 {
 130 public:
 131   enum class Action { Drop, Nxdomain, Refused, Spoof, Allow, HeaderModify, Pool, Delay, Truncate, ServFail, None, NoOp, NoRecurse };
 132   static std::string typeToString(const Action& action)
 133   {
 134     switch(action) {
 135     case Action::Drop:
 136       return "Drop";
 137     case Action::Nxdomain:
 138       return "Send NXDomain";
 139     case Action::Refused:
 140       return "Send Refused";
 141     case Action::Spoof:
 142       return "Spoof an answer";
 143     case Action::Allow:
 144       return "Allow";
 145     case Action::HeaderModify:
 146       return "Modify the header";
 147     case Action::Pool:
 148       return "Route to a pool";
 149     case Action::Delay:
 150       return "Delay";
 151     case Action::Truncate:
 152       return "Truncate over UDP";
 153     case Action::ServFail:
 154       return "Send ServFail";
 155     case Action::None:
 156     case Action::NoOp:
 157       return "Do nothing";
 158     case Action::NoRecurse:
 159       return "Set rd=0";
 160     }
 161
 162     return "Unknown";
 163   }
 164
 165   virtual Action operator()(DNSQuestion*, string* ruleresult) const =0;
 166   virtual ~DNSAction()
 167   {
 168   }
 169   virtual string toString() const = 0;
 170   virtual std::map<string, double> getStats() const
 171   {
 172     return {{}};
 173   }
 174 };
 175
 176 class DNSResponseAction
 177 {
 178 public:
 179   enum class Action { Allow, Delay, Drop, HeaderModify, ServFail, None };
 180   virtual Action operator()(DNSResponse*, string* ruleresult) const =0;
 181   virtual ~DNSResponseAction()
 182   {
 183   }
 184   virtual string toString() const = 0;
 185 };
 186
 187 struct DynBlock
 188 {
 189   DynBlock(): action(DNSAction::Action::None), warning(false)
 190   {
 191   }
 192
 193   DynBlock(const std::string& reason_, const struct timespec& until_, const DNSName& domain_, DNSAction::Action action_): reason(reason_), until(until_), domain(domain_), action(action_), warning(false)
 194   {
 195   }
 196
 197   DynBlock(const DynBlock& rhs): reason(rhs.reason), until(rhs.until), domain(rhs.domain), action(rhs.action), warning(rhs.warning)
 198   {
 199     blocks.store(rhs.blocks);
 200   }
 201
 202   DynBlock& operator=(const DynBlock& rhs)
 203   {
 204     reason=rhs.reason;
 205     until=rhs.until;
 206     domain=rhs.domain;
 207     action=rhs.action;
 208     blocks.store(rhs.blocks);
 209     warning=rhs.warning;
 210     return *this;
 211   }
 212
 213   string reason;
 214   struct timespec until;
 215   DNSName domain;
 216   DNSAction::Action action;
 217   mutable std::atomic<unsigned int> blocks;
 218   bool warning;
 219 };
 220
 221 extern GlobalStateHolder<NetmaskTree<DynBlock>> g_dynblockNMG;
 222
 223 extern vector<pair<struct timeval, std::string> > g_confDelta;
 224
 225 struct DNSDistStats
 226 {
 227   using stat_t=std::atomic<uint64_t>; // aww yiss ;-)
 228   stat_t responses{0};
 229   stat_t servfailResponses{0};
 230   stat_t queries{0};
 231   stat_t frontendNXDomain{0};
 232   stat_t frontendServFail{0};
 233   stat_t frontendNoError{0};
 234   stat_t nonCompliantQueries{0};
 235   stat_t nonCompliantResponses{0};
 236   stat_t rdQueries{0};
 237   stat_t emptyQueries{0};
 238   stat_t aclDrops{0};
 239   stat_t dynBlocked{0};
 240   stat_t ruleDrop{0};
 241   stat_t ruleNXDomain{0};
 242   stat_t ruleRefused{0};
 243   stat_t ruleServFail{0};
 244   stat_t selfAnswered{0};
 245   stat_t downstreamTimeouts{0};
 246   stat_t downstreamSendErrors{0};
 247   stat_t truncFail{0};
 248   stat_t noPolicy{0};
 249   stat_t cacheHits{0};
 250   stat_t cacheMisses{0};
 251   stat_t latency0_1{0}, latency1_10{0}, latency10_50{0}, latency50_100{0}, latency100_1000{0}, latencySlow{0};
 252   stat_t securityStatus{0};
 253
 254   double latencyAvg100{0}, latencyAvg1000{0}, latencyAvg10000{0}, latencyAvg1000000{0};
 255   typedef std::function<uint64_t(const std::string&)> statfunction_t;
 256   typedef boost::variant<stat_t*, double*, statfunction_t> entry_t;
 257   std::vector<std::pair<std::string, entry_t>> entries{
 258     {"responses", &responses},
 259     {"servfail-responses", &servfailResponses},
 260     {"queries", &queries},
 261     {"frontend-nxdomain", &frontendNXDomain},
 262     {"frontend-servfail", &frontendServFail},
 263     {"frontend-noerror", &frontendNoError},
 264     {"acl-drops", &aclDrops},
 265     {"rule-drop", &ruleDrop},
 266     {"rule-nxdomain", &ruleNXDomain},
 267     {"rule-refused", &ruleRefused},
 268     {"rule-servfail", &ruleServFail},
 269     {"self-answered", &selfAnswered},
 270     {"downstream-timeouts", &downstreamTimeouts},
 271     {"downstream-send-errors", &downstreamSendErrors},
 272     {"trunc-failures", &truncFail},
 273     {"no-policy", &noPolicy},
 274     {"latency0-1", &latency0_1},
 275     {"latency1-10", &latency1_10},
 276     {"latency10-50", &latency10_50},
 277     {"latency50-100", &latency50_100},
 278     {"latency100-1000", &latency100_1000},
 279     {"latency-slow", &latencySlow},
 280     {"latency-avg100", &latencyAvg100},
 281     {"latency-avg1000", &latencyAvg1000},
 282     {"latency-avg10000", &latencyAvg10000},
 283     {"latency-avg1000000", &latencyAvg1000000},
 284     {"uptime", uptimeOfProcess},
 285     {"real-memory-usage", getRealMemoryUsage},
 286     {"special-memory-usage", getSpecialMemoryUsage},
 287     {"noncompliant-queries", &nonCompliantQueries},
 288     {"noncompliant-responses", &nonCompliantResponses},
 289     {"rdqueries", &rdQueries},
 290     {"empty-queries", &emptyQueries},
 291     {"cache-hits", &cacheHits},
 292     {"cache-misses", &cacheMisses},
 293     {"cpu-user-msec", getCPUTimeUser},
 294     {"cpu-sys-msec", getCPUTimeSystem},
 295     {"fd-usage", getOpenFileDescriptors},
 296     {"dyn-blocked", &dynBlocked},
 297     {"dyn-block-nmg-size", [](const std::string&) { return g_dynblockNMG.getLocal()->size(); }},
 298     {"security-status", &securityStatus}
 299   };
 300 };
 301
 302 // Metric types for Prometheus
 303 enum class PrometheusMetricType: int {
 304     counter = 1,
 305     gauge = 2
 306 };
 307
 308 // Keeps additional information about metrics
 309 struct MetricDefinition {
 310   MetricDefinition(PrometheusMetricType _prometheusType, const std::string& _description): description(_description), prometheusType(_prometheusType) {
 311   }
 312
 313   MetricDefinition() = default;
 314
 315   // Metric description
 316   std::string description;
 317   // Metric type for Prometheus
 318   PrometheusMetricType prometheusType;
 319 };
 320
 321 struct MetricDefinitionStorage {
 322   // Return metric definition by name
 323   bool getMetricDetails(std::string metricName, MetricDefinition& metric) {
 324   auto metricDetailsIter = metrics.find(metricName);
 325
 326   if (metricDetailsIter == metrics.end()) {
 327     return false;
 328   }
 329
 330   metric = metricDetailsIter->second;
 331     return true;
 332   };
 333
 334   // Return string representation of Prometheus metric type
 335   std::string getPrometheusStringMetricType(PrometheusMetricType metricType) {
 336     switch (metricType) {
 337       case PrometheusMetricType::counter:
 338         return "counter";
 339         break;
 340       case PrometheusMetricType::gauge:
 341         return "gauge";
 342         break;
 343       default:
 344         return "";
 345         break;
 346     }
 347   };
 348
 349   std::map<std::string, MetricDefinition> metrics = {
 350     { "responses",              MetricDefinition(PrometheusMetricType::counter, "Number of responses received from backends") },
 351     { "servfail-responses",     MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers received from backends") },
 352     { "queries",                MetricDefinition(PrometheusMetricType::counter, "Number of received queries")},
 353     { "frontend-nxdomain",      MetricDefinition(PrometheusMetricType::counter, "Number of NXDomain answers sent to clients")},
 354     { "frontend-servfail",      MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers sent to clients")},
 355     { "frontend-noerror",       MetricDefinition(PrometheusMetricType::counter, "Number of NoError answers sent to clients")},
 356     { "acl-drops",              MetricDefinition(PrometheusMetricType::counter, "Number of packets dropped because of the ACL")},
 357     { "rule-drop",              MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because of a rule")},
 358     { "rule-nxdomain",          MetricDefinition(PrometheusMetricType::counter, "Number of NXDomain answers returned because of a rule")},
 359     { "rule-refused",           MetricDefinition(PrometheusMetricType::counter, "Number of Refused answers returned because of a rule")},
 360     { "rule-servfail",          MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers received because of a rule")},
 361     { "self-answered",          MetricDefinition(PrometheusMetricType::counter, "Number of self-answered responses")},
 362     { "downstream-timeouts",    MetricDefinition(PrometheusMetricType::counter, "Number of queries not answered in time by a backend")},
 363     { "downstream-send-errors", MetricDefinition(PrometheusMetricType::counter, "Number of errors when sending a query to a backend")},
 364     { "trunc-failures",         MetricDefinition(PrometheusMetricType::counter, "Number of errors encountered while truncating an answer")},
 365     { "no-policy",              MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because no server was available")},
 366     { "latency0-1",             MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in less than 1ms")},
 367     { "latency1-10",            MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 1-10 ms")},
 368     { "latency10-50",           MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 10-50 ms")},
 369     { "latency50-100",          MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 50-100 ms")},
 370     { "latency100-1000",        MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 100-1000 ms")},
 371     { "latency-slow",           MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in more than 1 second")},
 372     { "latency-avg100",         MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 100 packets")},
 373     { "latency-avg1000",        MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 1000 packets")},
 374     { "latency-avg10000",       MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 10000 packets")},
 375     { "latency-avg1000000",     MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 1000000 packets")},
 376     { "uptime",                 MetricDefinition(PrometheusMetricType::gauge,   "Uptime of the dnsdist process in seconds")},
 377     { "real-memory-usage",      MetricDefinition(PrometheusMetricType::gauge,   "Current memory usage in bytes")},
 378     { "noncompliant-queries",   MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped as non-compliant")},
 379     { "noncompliant-responses", MetricDefinition(PrometheusMetricType::counter, "Number of answers from a backend dropped as non-compliant")},
 380     { "rdqueries",              MetricDefinition(PrometheusMetricType::counter, "Number of received queries with the recursion desired bit set")},
 381     { "empty-queries",          MetricDefinition(PrometheusMetricType::counter, "Number of empty queries received from clients")},
 382     { "cache-hits",             MetricDefinition(PrometheusMetricType::counter, "Number of times an answer was retrieved from cache")},
 383     { "cache-misses",           MetricDefinition(PrometheusMetricType::counter, "Number of times an answer not found in the cache")},
 384     { "cpu-user-msec",          MetricDefinition(PrometheusMetricType::counter, "Milliseconds spent by dnsdist in the user state")},
 385     { "cpu-sys-msec",           MetricDefinition(PrometheusMetricType::counter, "Milliseconds spent by dnsdist in the system state")},
 386     { "fd-usage",               MetricDefinition(PrometheusMetricType::gauge,   "Number of currently used file descriptors")},
 387     { "dyn-blocked",            MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because of a dynamic block")},
 388     { "dyn-block-nmg-size",     MetricDefinition(PrometheusMetricType::gauge,   "Number of dynamic blocks entries") },
 389     { "security-status",        MetricDefinition(PrometheusMetricType::gauge,   "Security status of this software. 0=unknown, 1=OK, 2=upgrade recommended, 3=upgrade mandatory") },
 390   };
 391 };
 392
 393 extern MetricDefinitionStorage g_metricDefinitions;
 394 extern struct DNSDistStats g_stats;
 395 void doLatencyStats(double udiff);
 396
 397
 398 struct StopWatch
 399 {
 400   StopWatch(bool realTime=false): d_needRealTime(realTime)
 401   {
 402   }
 403   struct timespec d_start{0,0};
 404   bool d_needRealTime{false};
 405
 406   void start() {
 407     if(gettime(&d_start, d_needRealTime) < 0)
 408       unixDie("Getting timestamp");
 409
 410   }
 411
 412   void set(const struct timespec& from) {
 413     d_start = from;
 414   }
 415
 416   double udiff() const {
 417     struct timespec now;
 418     if(gettime(&now, d_needRealTime) < 0)
 419       unixDie("Getting timestamp");
 420
 421     return 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
 422   }
 423
 424   double udiffAndSet() {
 425     struct timespec now;
 426     if(gettime(&now, d_needRealTime) < 0)
 427       unixDie("Getting timestamp");
 428
 429     auto ret= 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
 430     d_start = now;
 431     return ret;
 432   }
 433
 434 };
 435
 436 class BasicQPSLimiter
 437 {
 438 public:
 439   BasicQPSLimiter()
 440   {
 441   }
 442
 443   BasicQPSLimiter(unsigned int burst): d_tokens(burst)
 444   {
 445     d_prev.start();
 446   }
 447
 448   bool check(unsigned int rate, unsigned int burst) const // this is not quite fair
 449   {
 450     auto delta = d_prev.udiffAndSet();
 451
 452     if(delta > 0.0) // time, frequently, does go backwards..
 453       d_tokens += 1.0 * rate * (delta/1000000.0);
 454
 455     if(d_tokens > burst) {
 456       d_tokens = burst;
 457     }
 458
 459     bool ret=false;
 460     if(d_tokens >= 1.0) { // we need this because burst=1 is weird otherwise
 461       ret=true;
 462       --d_tokens;
 463     }
 464
 465     return ret;
 466   }
 467
 468   bool seenSince(const struct timespec& cutOff) const
 469   {
 470     return cutOff < d_prev.d_start;
 471   }
 472
 473 protected:
 474   mutable StopWatch d_prev;
 475   mutable double d_tokens;
 476 };
 477
 478 class QPSLimiter : public BasicQPSLimiter
 479 {
 480 public:
 481   QPSLimiter(): BasicQPSLimiter()
 482   {
 483   }
 484
 485   QPSLimiter(unsigned int rate, unsigned int burst): BasicQPSLimiter(burst), d_rate(rate), d_burst(burst), d_passthrough(false)
 486   {
 487     d_prev.start();
 488   }
 489
 490   unsigned int getRate() const
 491   {
 492     return d_passthrough ? 0 : d_rate;
 493   }
 494
 495   int getPassed() const
 496   {
 497     return d_passed;
 498   }
 499
 500   int getBlocked() const
 501   {
 502     return d_blocked;
 503   }
 504
 505   bool check() const // this is not quite fair
 506   {
 507     if (d_passthrough) {
 508       return true;
 509     }
 510
 511     bool ret = BasicQPSLimiter::check(d_rate, d_burst);
 512     if (ret) {
 513       d_passed++;
 514     }
 515     else {
 516       d_blocked++;
 517     }
 518
 519     return ret;
 520   }
 521 private:
 522   mutable unsigned int d_passed{0};
 523   mutable unsigned int d_blocked{0};
 524   unsigned int d_rate;
 525   unsigned int d_burst;
 526   bool d_passthrough{true};
 527 };
 528
 529 struct ClientState;
 530
 531 struct IDState
 532 {
 533   IDState() : origFD(-1), sentTime(true), delayMsec(0), tempFailureTTL(boost::none) { origDest.sin4.sin_family = 0;}
 534   IDState(const IDState& orig): origRemote(orig.origRemote), origDest(orig.origDest), age(orig.age)
 535   {
 536     origFD.store(orig.origFD.load());
 537     origID = orig.origID;
 538     delayMsec = orig.delayMsec;
 539     tempFailureTTL = orig.tempFailureTTL;
 540   }
 541
 542   std::atomic<int> origFD;  // set to <0 to indicate this state is empty   // 4
 543
 544   ComboAddress origRemote;                                    // 28
 545   ComboAddress origDest;                                      // 28
 546   StopWatch sentTime;                                         // 16
 547   DNSName qname;                                              // 80
 548   std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
 549 #ifdef HAVE_PROTOBUF
 550   boost::optional<boost::uuids::uuid> uniqueId;
 551 #endif
 552   boost::optional<Netmask> subnet{boost::none};
 553   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
 554   std::shared_ptr<QTag> qTag{nullptr};
 555   const ClientState* cs{nullptr};
 556   uint32_t cacheKey;                                          // 4
 557   uint32_t cacheKeyNoECS;                                     // 4
 558   uint16_t age;                                               // 4
 559   uint16_t qtype;                                             // 2
 560   uint16_t qclass;                                            // 2
 561   uint16_t origID;                                            // 2
 562   uint16_t origFlags;                                         // 2
 563   int delayMsec;
 564   boost::optional<uint32_t> tempFailureTTL;
 565   bool ednsAdded{false};
 566   bool ecsAdded{false};
 567   bool skipCache{false};
 568   bool destHarvested{false}; // if true, origDest holds the original dest addr, otherwise the listening addr
 569   bool dnssecOK{false};
 570   bool useZeroScope;
 571 };
 572
 573 typedef std::unordered_map<string, unsigned int> QueryCountRecords;
 574 typedef std::function<std::tuple<bool, string>(const DNSQuestion* dq)> QueryCountFilter;
 575 struct QueryCount {
 576   QueryCount()
 577   {
 578     pthread_rwlock_init(&queryLock, nullptr);
 579   }
 580   QueryCountRecords records;
 581   QueryCountFilter filter;
 582   pthread_rwlock_t queryLock;
 583   bool enabled{false};
 584 };
 585
 586 extern QueryCount g_qcount;
 587
 588 struct ClientState
 589 {
 590   std::set<int> cpus;
 591   ComboAddress local;
 592   std::shared_ptr<DNSCryptContext> dnscryptCtx{nullptr};
 593   shared_ptr<TLSFrontend> tlsFrontend;
 594   std::atomic<uint64_t> queries{0};
 595   std::atomic<uint64_t> tcpDiedReadingQuery{0};
 596   std::atomic<uint64_t> tcpDiedSendingResponse{0};
 597   std::atomic<uint64_t> tcpGaveUp{0};
 598   std::atomic<uint64_t> tcpClientTimeouts{0};
 599   std::atomic<uint64_t> tcpDownstreamTimeouts{0};
 600   std::atomic<uint64_t> tcpCurrentConnections{0};
 601   std::atomic<double> tcpAvgQueriesPerConnection{0.0};
 602   /* in ms */
 603   std::atomic<double> tcpAvgConnectionDuration{0.0};
 604   int udpFD{-1};
 605   int tcpFD{-1};
 606   bool muted{false};
 607
 608   int getSocket() const
 609   {
 610     return udpFD != -1 ? udpFD : tcpFD;
 611   }
 612
 613   std::string getType() const
 614   {
 615     std::string result = udpFD != -1 ? "UDP" : "TCP";
 616
 617     if (tlsFrontend) {
 618       result += " (DNS over TLS)";
 619     }
 620     else if (dnscryptCtx) {
 621       result += " (DNSCrypt)";
 622     }
 623
 624     return result;
 625   }
 626
 627 #ifdef HAVE_EBPF
 628   shared_ptr<BPFFilter> d_filter;
 629
 630   void detachFilter()
 631   {
 632     if (d_filter) {
 633       d_filter->removeSocket(getSocket());
 634       d_filter = nullptr;
 635     }
 636   }
 637
 638   void attachFilter(shared_ptr<BPFFilter> bpf)
 639   {
 640     detachFilter();
 641
 642     bpf->addSocket(getSocket());
 643     d_filter = bpf;
 644   }
 645 #endif /* HAVE_EBPF */
 646
 647   void updateTCPMetrics(size_t queries, uint64_t durationMs)
 648   {
 649     tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (queries / 100.0);
 650     tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
 651   }
 652 };
 653
 654 class TCPClientCollection {
 655   std::vector<int> d_tcpclientthreads;
 656   std::atomic<uint64_t> d_numthreads{0};
 657   std::atomic<uint64_t> d_pos{0};
 658   std::atomic<uint64_t> d_queued{0};
 659   const uint64_t d_maxthreads{0};
 660   std::mutex d_mutex;
 661   int d_singlePipe[2];
 662   const bool d_useSinglePipe;
 663 public:
 664
 665   TCPClientCollection(size_t maxThreads, bool useSinglePipe=false): d_maxthreads(maxThreads), d_singlePipe{-1,-1}, d_useSinglePipe(useSinglePipe)
 666
 667   {
 668     d_tcpclientthreads.reserve(maxThreads);
 669
 670     if (d_useSinglePipe) {
 671       if (pipe(d_singlePipe) < 0) {
 672         throw std::runtime_error("Error creating the TCP single communication pipe: " + string(strerror(errno)));
 673       }
 674
 675       if (!setNonBlocking(d_singlePipe[0])) {
 676         int err = errno;
 677         close(d_singlePipe[0]);
 678         close(d_singlePipe[1]);
 679         throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + string(strerror(err)));
 680       }
 681
 682       if (!setNonBlocking(d_singlePipe[1])) {
 683         int err = errno;
 684         close(d_singlePipe[0]);
 685         close(d_singlePipe[1]);
 686         throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + string(strerror(err)));
 687       }
 688     }
 689   }
 690   int getThread()
 691   {
 692     uint64_t pos = d_pos++;
 693     ++d_queued;
 694     return d_tcpclientthreads[pos % d_numthreads];
 695   }
 696   bool hasReachedMaxThreads() const
 697   {
 698     return d_numthreads >= d_maxthreads;
 699   }
 700   uint64_t getThreadsCount() const
 701   {
 702     return d_numthreads;
 703   }
 704   uint64_t getQueuedCount() const
 705   {
 706     return d_queued;
 707   }
 708   void decrementQueuedCount()
 709   {
 710     --d_queued;
 711   }
 712   void addTCPClientThread();
 713 };
 714
 715 extern std::unique_ptr<TCPClientCollection> g_tcpclientthreads;
 716
 717 struct DownstreamState
 718 {
 719    typedef std::function<std::tuple<DNSName, uint16_t, uint16_t>(const DNSName&, uint16_t, uint16_t, dnsheader*)> checkfunc_t;
 720
 721   DownstreamState(const ComboAddress& remote_, const ComboAddress& sourceAddr_, unsigned int sourceItf, size_t numberOfSockets);
 722   DownstreamState(const ComboAddress& remote_): DownstreamState(remote_, ComboAddress(), 0, 1) {}
 723   ~DownstreamState()
 724   {
 725     for (auto& fd : sockets) {
 726       if (fd >= 0) {
 727         close(fd);
 728         fd = -1;
 729       }
 730     }
 731   }
 732   boost::uuids::uuid id;
 733   std::set<unsigned int> hashes;
 734   mutable pthread_rwlock_t d_lock;
 735   std::vector<int> sockets;
 736   std::mutex socketsLock;
 737   std::mutex connectLock;
 738   std::unique_ptr<FDMultiplexer> mplexer{nullptr};
 739   std::thread tid;
 740   const ComboAddress remote;
 741   QPSLimiter qps;
 742   vector<IDState> idStates;
 743   const ComboAddress sourceAddr;
 744   checkfunc_t checkFunction;
 745   DNSName checkName{"a.root-servers.net."};
 746   QType checkType{QType::A};
 747   uint16_t checkClass{QClass::IN};
 748   std::atomic<uint64_t> idOffset{0};
 749   std::atomic<uint64_t> sendErrors{0};
 750   std::atomic<uint64_t> outstanding{0};
 751   std::atomic<uint64_t> reuseds{0};
 752   std::atomic<uint64_t> queries{0};
 753   struct {
 754     std::atomic<uint64_t> sendErrors{0};
 755     std::atomic<uint64_t> reuseds{0};
 756     std::atomic<uint64_t> queries{0};
 757   } prev;
 758   std::atomic<uint64_t> tcpDiedSendingQuery{0};
 759   std::atomic<uint64_t> tcpDiedReadingResponse{0};
 760   std::atomic<uint64_t> tcpGaveUp{0};
 761   std::atomic<uint64_t> tcpReadTimeouts{0};
 762   std::atomic<uint64_t> tcpWriteTimeouts{0};
 763   std::atomic<uint64_t> tcpCurrentConnections{0};
 764   std::atomic<double> tcpAvgQueriesPerConnection{0.0};
 765   /* in ms */
 766   std::atomic<double> tcpAvgConnectionDuration{0.0};
 767   string name;
 768   size_t socketsOffset{0};
 769   double queryLoad{0.0};
 770   double dropRate{0.0};
 771   double latencyUsec{0.0};
 772   int order{1};
 773   int weight{1};
 774   int tcpConnectTimeout{5};
 775   int tcpRecvTimeout{30};
 776   int tcpSendTimeout{30};
 777   unsigned int checkInterval{1};
 778   unsigned int lastCheck{0};
 779   const unsigned int sourceItf{0};
 780   uint16_t retries{5};
 781   uint16_t xpfRRCode{0};
 782   uint16_t checkTimeout{1000}; /* in milliseconds */
 783   uint8_t currentCheckFailures{0};
 784   uint8_t consecutiveSuccessfulChecks{0};
 785   uint8_t maxCheckFailures{1};
 786   uint8_t minRiseSuccesses{1};
 787   StopWatch sw;
 788   set<string> pools;
 789   enum class Availability { Up, Down, Auto} availability{Availability::Auto};
 790   bool mustResolve{false};
 791   bool upStatus{false};
 792   bool useECS{false};
 793   bool setCD{false};
 794   bool disableZeroScope{false};
 795   std::atomic<bool> connected{false};
 796   std::atomic_flag threadStarted;
 797   bool tcpFastOpen{false};
 798   bool ipBindAddrNoPort{true};
 799
 800   bool isUp() const
 801   {
 802     if(availability == Availability::Down)
 803       return false;
 804     if(availability == Availability::Up)
 805       return true;
 806     return upStatus;
 807   }
 808   void setUp() { availability = Availability::Up; }
 809   void setDown() { availability = Availability::Down; }
 810   void setAuto() { availability = Availability::Auto; }
 811   string getName() const {
 812     if (name.empty()) {
 813       return remote.toStringWithPort();
 814     }
 815     return name;
 816   }
 817   string getNameWithAddr() const {
 818     if (name.empty()) {
 819       return remote.toStringWithPort();
 820     }
 821     return name + " (" + remote.toStringWithPort()+ ")";
 822   }
 823   string getStatus() const
 824   {
 825     string status;
 826     if(availability == DownstreamState::Availability::Up)
 827       status = "UP";
 828     else if(availability == DownstreamState::Availability::Down)
 829       status = "DOWN";
 830     else
 831       status = (upStatus ? "up" : "down");
 832     return status;
 833   }
 834   bool reconnect();
 835   void hash();
 836   void setId(const boost::uuids::uuid& newId);
 837   void setWeight(int newWeight);
 838
 839   void updateTCPMetrics(size_t queries, uint64_t durationMs)
 840   {
 841     tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (queries / 100.0);
 842     tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
 843   }
 844 };
 845 using servers_t =vector<std::shared_ptr<DownstreamState>>;
 846
 847 template <class T> using NumberedVector = std::vector<std::pair<unsigned int, T> >;
 848
 849 void responderThread(std::shared_ptr<DownstreamState> state);
 850 extern std::mutex g_luamutex;
 851 extern LuaContext g_lua;
 852 extern std::string g_outputBuffer; // locking for this is ok, as locked by g_luamutex
 853
 854 class DNSRule
 855 {
 856 public:
 857   virtual ~DNSRule ()
 858   {
 859   }
 860   virtual bool matches(const DNSQuestion* dq) const =0;
 861   virtual string toString() const = 0;
 862   mutable std::atomic<uint64_t> d_matches{0};
 863 };
 864
 865 using NumberedServerVector = NumberedVector<shared_ptr<DownstreamState>>;
 866 typedef std::function<shared_ptr<DownstreamState>(const NumberedServerVector& servers, const DNSQuestion*)> policyfunc_t;
 867
 868 struct ServerPolicy
 869 {
 870   string name;
 871   policyfunc_t policy;
 872   bool isLua;
 873   std::string toString() const {
 874     return string("ServerPolicy") + (isLua ? " (Lua)" : "") + " \"" + name + "\"";
 875   }
 876 };
 877
 878 struct ServerPool
 879 {
 880   ServerPool()
 881   {
 882     pthread_rwlock_init(&d_lock, nullptr);
 883   }
 884
 885   const std::shared_ptr<DNSDistPacketCache> getCache() const { return packetCache; };
 886
 887   bool getECS() const
 888   {
 889     return d_useECS;
 890   }
 891
 892   void setECS(bool useECS)
 893   {
 894     d_useECS = useECS;
 895   }
 896
 897   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
 898   std::shared_ptr<ServerPolicy> policy{nullptr};
 899
 900   size_t countServers(bool upOnly)
 901   {
 902     size_t count = 0;
 903     ReadLock rl(&d_lock);
 904     for (const auto& server : d_servers) {
 905       if (!upOnly || std::get<1>(server)->isUp() ) {
 906         count++;
 907       }
 908     }
 909     return count;
 910   }
 911
 912   NumberedVector<shared_ptr<DownstreamState>> getServers()
 913   {
 914     NumberedVector<shared_ptr<DownstreamState>> result;
 915     {
 916       ReadLock rl(&d_lock);
 917       result = d_servers;
 918     }
 919     return result;
 920   }
 921
 922   void addServer(shared_ptr<DownstreamState>& server)
 923   {
 924     WriteLock wl(&d_lock);
 925     unsigned int count = (unsigned int) d_servers.size();
 926     d_servers.push_back(make_pair(++count, server));
 927     /* we need to reorder based on the server 'order' */
 928     std::stable_sort(d_servers.begin(), d_servers.end(), [](const std::pair<unsigned int,std::shared_ptr<DownstreamState> >& a, const std::pair<unsigned int,std::shared_ptr<DownstreamState> >& b) {
 929       return a.second->order < b.second->order;
 930     });
 931     /* and now we need to renumber for Lua (custom policies) */
 932     size_t idx = 1;
 933     for (auto& serv : d_servers) {
 934       serv.first = idx++;
 935     }
 936   }
 937
 938   void removeServer(shared_ptr<DownstreamState>& server)
 939   {
 940     WriteLock wl(&d_lock);
 941     size_t idx = 1;
 942     bool found = false;
 943     for (auto it = d_servers.begin(); it != d_servers.end();) {
 944       if (found) {
 945         /* we need to renumber the servers placed
 946            after the removed one, for Lua (custom policies) */
 947         it->first = idx++;
 948         it++;
 949       }
 950       else if (it->second == server) {
 951         it = d_servers.erase(it);
 952         found = true;
 953       } else {
 954         idx++;
 955         it++;
 956       }
 957     }
 958   }
 959
 960 private:
 961   NumberedVector<shared_ptr<DownstreamState>> d_servers;
 962   pthread_rwlock_t d_lock;
 963   bool d_useECS{false};
 964 };
 965 using pools_t=map<std::string,std::shared_ptr<ServerPool>>;
 966 void setPoolPolicy(pools_t& pools, const string& poolName, std::shared_ptr<ServerPolicy> policy);
 967 void addServerToPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
 968 void removeServerFromPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
 969
 970 struct CarbonConfig
 971 {
 972   ComboAddress server;
 973   std::string namespace_name;
 974   std::string ourname;
 975   std::string instance_name;
 976   unsigned int interval;
 977 };
 978
 979 enum ednsHeaderFlags {
 980   EDNS_HEADER_FLAG_NONE = 0,
 981   EDNS_HEADER_FLAG_DO = 32768
 982 };
 983
 984 struct DNSDistRuleAction
 985 {
 986   std::shared_ptr<DNSRule> d_rule;
 987   std::shared_ptr<DNSAction> d_action;
 988   boost::uuids::uuid d_id;
 989   uint64_t d_creationOrder;
 990 };
 991
 992 struct DNSDistResponseRuleAction
 993 {
 994   std::shared_ptr<DNSRule> d_rule;
 995   std::shared_ptr<DNSResponseAction> d_action;
 996   boost::uuids::uuid d_id;
 997   uint64_t d_creationOrder;
 998 };
 999
1000 extern GlobalStateHolder<SuffixMatchTree<DynBlock>> g_dynblockSMT;
1001 extern DNSAction::Action g_dynBlockAction;
1002
1003 extern GlobalStateHolder<vector<CarbonConfig> > g_carbon;
1004 extern GlobalStateHolder<ServerPolicy> g_policy;
1005 extern GlobalStateHolder<servers_t> g_dstates;
1006 extern GlobalStateHolder<pools_t> g_pools;
1007 extern GlobalStateHolder<vector<DNSDistRuleAction> > g_rulactions;
1008 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_resprulactions;
1009 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_cachehitresprulactions;
1010 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_selfansweredresprulactions;
1011 extern GlobalStateHolder<NetmaskGroup> g_ACL;
1012
1013 extern ComboAddress g_serverControl; // not changed during runtime
1014
1015 extern std::vector<std::tuple<ComboAddress, bool, bool, int, std::string, std::set<int>>> g_locals; // not changed at runtime (we hope XXX)
1016 extern std::vector<shared_ptr<TLSFrontend>> g_tlslocals;
1017 extern vector<ClientState*> g_frontends;
1018 extern bool g_truncateTC;
1019 extern bool g_fixupCase;
1020 extern int g_tcpRecvTimeout;
1021 extern int g_tcpSendTimeout;
1022 extern int g_udpTimeout;
1023 extern uint16_t g_maxOutstanding;
1024 extern std::atomic<bool> g_configurationDone;
1025 extern uint64_t g_maxTCPClientThreads;
1026 extern uint64_t g_maxTCPQueuedConnections;
1027 extern size_t g_maxTCPQueriesPerConn;
1028 extern size_t g_maxTCPConnectionDuration;
1029 extern size_t g_maxTCPConnectionsPerClient;
1030 extern std::atomic<uint16_t> g_cacheCleaningDelay;
1031 extern std::atomic<uint16_t> g_cacheCleaningPercentage;
1032 extern bool g_verboseHealthChecks;
1033 extern uint32_t g_staleCacheEntriesTTL;
1034 extern bool g_apiReadWrite;
1035 extern std::string g_apiConfigDirectory;
1036 extern bool g_servFailOnNoPolicy;
1037 extern uint32_t g_hashperturb;
1038 extern bool g_useTCPSinglePipe;
1039 extern uint16_t g_downstreamTCPCleanupInterval;
1040 extern size_t g_udpVectorSize;
1041 extern bool g_preserveTrailingData;
1042 extern bool g_allowEmptyResponse;
1043 extern bool g_roundrobinFailOnNoServer;
1044
1045 #ifdef HAVE_EBPF
1046 extern shared_ptr<BPFFilter> g_defaultBPFFilter;
1047 extern std::vector<std::shared_ptr<DynBPFFilter> > g_dynBPFFilters;
1048 #endif /* HAVE_EBPF */
1049
1050 struct LocalHolders
1051 {
1052   LocalHolders(): acl(g_ACL.getLocal()), policy(g_policy.getLocal()), rulactions(g_rulactions.getLocal()), cacheHitRespRulactions(g_cachehitresprulactions.getLocal()), selfAnsweredRespRulactions(g_selfansweredresprulactions.getLocal()), servers(g_dstates.getLocal()), dynNMGBlock(g_dynblockNMG.getLocal()), dynSMTBlock(g_dynblockSMT.getLocal()), pools(g_pools.getLocal())
1053   {
1054   }
1055
1056   LocalStateHolder<NetmaskGroup> acl;
1057   LocalStateHolder<ServerPolicy> policy;
1058   LocalStateHolder<vector<DNSDistRuleAction> > rulactions;
1059   LocalStateHolder<vector<DNSDistResponseRuleAction> > cacheHitRespRulactions;
1060   LocalStateHolder<vector<DNSDistResponseRuleAction> > selfAnsweredRespRulactions;
1061   LocalStateHolder<servers_t> servers;
1062   LocalStateHolder<NetmaskTree<DynBlock> > dynNMGBlock;
1063   LocalStateHolder<SuffixMatchTree<DynBlock> > dynSMTBlock;
1064   LocalStateHolder<pools_t> pools;
1065 };
1066
1067 struct dnsheader;
1068
1069 void controlThread(int fd, ComboAddress local);
1070 vector<std::function<void(void)>> setupLua(bool client, const std::string& config);
1071 std::shared_ptr<ServerPool> getPool(const pools_t& pools, const std::string& poolName);
1072 std::shared_ptr<ServerPool> createPoolIfNotExists(pools_t& pools, const string& poolName);
1073 NumberedServerVector getDownstreamCandidates(const pools_t& pools, const std::string& poolName);
1074
1075 std::shared_ptr<DownstreamState> firstAvailable(const NumberedServerVector& servers, const DNSQuestion* dq);
1076
1077 std::shared_ptr<DownstreamState> leastOutstanding(const NumberedServerVector& servers, const DNSQuestion* dq);
1078 std::shared_ptr<DownstreamState> wrandom(const NumberedServerVector& servers, const DNSQuestion* dq);
1079 std::shared_ptr<DownstreamState> whashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1080 std::shared_ptr<DownstreamState> chashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1081 std::shared_ptr<DownstreamState> roundrobin(const NumberedServerVector& servers, const DNSQuestion* dq);
1082
1083 struct WebserverConfig
1084 {
1085   std::string password;
1086   std::string apiKey;
1087   boost::optional<std::map<std::string, std::string> > customHeaders;
1088   std::mutex lock;
1089 };
1090
1091 void setWebserverAPIKey(const boost::optional<std::string> apiKey);
1092 void setWebserverPassword(const std::string& password);
1093 void setWebserverCustomHeaders(const boost::optional<std::map<std::string, std::string> > customHeaders);
1094
1095 void dnsdistWebserverThread(int sock, const ComboAddress& local);
1096 void tcpAcceptorThread(void* p);
1097
1098 void setLuaNoSideEffect(); // if nothing has been declared, set that there are no side effects
1099 void setLuaSideEffect();   // set to report a side effect, cancelling all _no_ side effect calls
1100 bool getLuaNoSideEffect(); // set if there were only explicit declarations of _no_ side effect
1101 void resetLuaSideEffect(); // reset to indeterminate state
1102
1103 bool responseContentMatches(const char* response, const uint16_t responseLen, const DNSName& qname, const uint16_t qtype, const uint16_t qclass, const ComboAddress& remote, unsigned int& consumed);
1104 bool processResponse(char** response, uint16_t* responseLen, size_t* responseSize, LocalStateHolder<vector<DNSDistResponseRuleAction> >& localRespRulactions, DNSResponse& dr, size_t addRoom, std::vector<uint8_t>& rewrittenResponse, bool muted);
1105
1106 bool checkQueryHeaders(const struct dnsheader* dh);
1107
1108 extern std::vector<std::tuple<ComboAddress, std::shared_ptr<DNSCryptContext>, bool, int, std::string, std::set<int> > > g_dnsCryptLocals;
1109 int handleDNSCryptQuery(char* packet, uint16_t len, std::shared_ptr<DNSCryptQuery> query, uint16_t* decryptedQueryLen, bool tcp, time_t now, std::vector<uint8_t>& response);
1110 boost::optional<std::vector<uint8_t>> checkDNSCryptQuery(const ClientState& cs, const char* query, uint16_t& len, std::shared_ptr<DNSCryptQuery>& dnsCryptQuery, time_t now, bool tcp);
1111
1112 bool addXPF(DNSQuestion& dq, uint16_t optionCode);
1113
1114 uint16_t getRandomDNSID();
1115
1116 #include "dnsdist-snmp.hh"
1117
1118 extern bool g_snmpEnabled;
1119 extern bool g_snmpTrapsEnabled;
1120 extern DNSDistSNMPAgent* g_snmpAgent;
1121 extern bool g_addEDNSToSelfGeneratedResponses;
1122
1123 static const size_t s_udpIncomingBufferSize{1500};
1124
1125 enum class ProcessQueryResult { Drop, SendAnswer, PassToBackend };
1126 ProcessQueryResult processQuery(DNSQuestion& dq, ClientState& cs, LocalHolders& holders, std::shared_ptr<DownstreamState>& selectedBackend);
1127
1128 DNSResponse makeDNSResponseFromIDState(IDState& ids, struct dnsheader* dh, size_t bufferSize, uint16_t responseLen, bool isTCP);
1129 void setIDStateFromDNSQuestion(IDState& ids, DNSQuestion& dq, DNSName&& qname);