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 "doh.hh"
  44 #include "ednsoptions.hh"
  45 #include "gettime.hh"
  46 #include "iputils.hh"
  47 #include "misc.hh"
  48 #include "mplexer.hh"
  49 #include "sholder.hh"
  50 #include "tcpiohandler.hh"
  51 #include "uuid-utils.hh"
  52
  53 void carbonDumpThread();
  54 uint64_t uptimeOfProcess(const std::string& str);
  55
  56 extern uint16_t g_ECSSourcePrefixV4;
  57 extern uint16_t g_ECSSourcePrefixV6;
  58 extern bool g_ECSOverride;
  59
  60 typedef std::unordered_map<string, string> QTag;
  61
  62 struct DNSQuestion
  63 {
  64   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_):
  65     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) {
  66     const uint16_t* flags = getFlagsFromDNSHeader(dh);
  67     origFlags = *flags;
  68   }
  69   DNSQuestion(const DNSQuestion&) = delete;
  70   DNSQuestion& operator=(const DNSQuestion&) = delete;
  71   DNSQuestion(DNSQuestion&&) = default;
  72
  73 #ifdef HAVE_PROTOBUF
  74   boost::optional<boost::uuids::uuid> uniqueId;
  75 #endif
  76   Netmask ecs;
  77   boost::optional<Netmask> subnet;
  78   std::string sni; /* Server Name Indication, if any (DoT or DoH) */
  79   const DNSName* qname{nullptr};
  80   const ComboAddress* local{nullptr};
  81   const ComboAddress* remote{nullptr};
  82   std::shared_ptr<QTag> qTag{nullptr};
  83   std::shared_ptr<std::map<uint16_t, EDNSOptionView> > ednsOptions;
  84   std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
  85   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
  86   struct dnsheader* dh{nullptr};
  87   const struct timespec* queryTime{nullptr};
  88   struct DOHUnit* du{nullptr};
  89   size_t size;
  90   unsigned int consumed{0};
  91   int delayMsec{0};
  92   boost::optional<uint32_t> tempFailureTTL;
  93   uint32_t cacheKeyNoECS;
  94   uint32_t cacheKey;
  95   const uint16_t qtype;
  96   const uint16_t qclass;
  97   uint16_t len;
  98   uint16_t ecsPrefixLength;
  99   uint16_t origFlags;
 100   uint8_t ednsRCode{0};
 101   const bool tcp;
 102   bool skipCache{false};
 103   bool ecsOverride;
 104   bool useECS{true};
 105   bool addXPF{true};
 106   bool ecsSet{false};
 107   bool ecsAdded{false};
 108   bool ednsAdded{false};
 109   bool useZeroScope{false};
 110   bool dnssecOK{false};
 111 };
 112
 113 struct DNSResponse : DNSQuestion
 114 {
 115   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_):
 116     DNSQuestion(name, type, class_, consumed, lc, rem, header, bufferSize, responseLen, isTcp, queryTime_) { }
 117   DNSResponse(const DNSResponse&) = delete;
 118   DNSResponse& operator=(const DNSResponse&) = delete;
 119   DNSResponse(DNSResponse&&) = default;
 120 };
 121
 122 /* so what could you do:
 123    drop,
 124    fake up nxdomain,
 125    provide actual answer,
 126    allow & and stop processing,
 127    continue processing,
 128    modify header:    (servfail|refused|notimp), set TC=1,
 129    send to pool */
 130
 131 class DNSAction
 132 {
 133 public:
 134   enum class Action { Drop, Nxdomain, Refused, Spoof, Allow, HeaderModify, Pool, Delay, Truncate, ServFail, None, NoOp, NoRecurse };
 135   static std::string typeToString(const Action& action)
 136   {
 137     switch(action) {
 138     case Action::Drop:
 139       return "Drop";
 140     case Action::Nxdomain:
 141       return "Send NXDomain";
 142     case Action::Refused:
 143       return "Send Refused";
 144     case Action::Spoof:
 145       return "Spoof an answer";
 146     case Action::Allow:
 147       return "Allow";
 148     case Action::HeaderModify:
 149       return "Modify the header";
 150     case Action::Pool:
 151       return "Route to a pool";
 152     case Action::Delay:
 153       return "Delay";
 154     case Action::Truncate:
 155       return "Truncate over UDP";
 156     case Action::ServFail:
 157       return "Send ServFail";
 158     case Action::None:
 159     case Action::NoOp:
 160       return "Do nothing";
 161     case Action::NoRecurse:
 162       return "Set rd=0";
 163     }
 164
 165     return "Unknown";
 166   }
 167
 168   virtual Action operator()(DNSQuestion*, string* ruleresult) const =0;
 169   virtual ~DNSAction()
 170   {
 171   }
 172   virtual string toString() const = 0;
 173   virtual std::map<string, double> getStats() const
 174   {
 175     return {{}};
 176   }
 177 };
 178
 179 class DNSResponseAction
 180 {
 181 public:
 182   enum class Action { Allow, Delay, Drop, HeaderModify, ServFail, None };
 183   virtual Action operator()(DNSResponse*, string* ruleresult) const =0;
 184   virtual ~DNSResponseAction()
 185   {
 186   }
 187   virtual string toString() const = 0;
 188 };
 189
 190 struct DynBlock
 191 {
 192   DynBlock(): action(DNSAction::Action::None), warning(false)
 193   {
 194   }
 195
 196   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)
 197   {
 198   }
 199
 200   DynBlock(const DynBlock& rhs): reason(rhs.reason), until(rhs.until), domain(rhs.domain), action(rhs.action), warning(rhs.warning)
 201   {
 202     blocks.store(rhs.blocks);
 203   }
 204
 205   DynBlock& operator=(const DynBlock& rhs)
 206   {
 207     reason=rhs.reason;
 208     until=rhs.until;
 209     domain=rhs.domain;
 210     action=rhs.action;
 211     blocks.store(rhs.blocks);
 212     warning=rhs.warning;
 213     return *this;
 214   }
 215
 216   string reason;
 217   struct timespec until;
 218   DNSName domain;
 219   DNSAction::Action action;
 220   mutable std::atomic<unsigned int> blocks;
 221   bool warning;
 222 };
 223
 224 extern GlobalStateHolder<NetmaskTree<DynBlock>> g_dynblockNMG;
 225
 226 extern vector<pair<struct timeval, std::string> > g_confDelta;
 227
 228 struct DNSDistStats
 229 {
 230   using stat_t=std::atomic<uint64_t>; // aww yiss ;-)
 231   stat_t responses{0};
 232   stat_t servfailResponses{0};
 233   stat_t queries{0};
 234   stat_t frontendNXDomain{0};
 235   stat_t frontendServFail{0};
 236   stat_t frontendNoError{0};
 237   stat_t nonCompliantQueries{0};
 238   stat_t nonCompliantResponses{0};
 239   stat_t rdQueries{0};
 240   stat_t emptyQueries{0};
 241   stat_t aclDrops{0};
 242   stat_t dynBlocked{0};
 243   stat_t ruleDrop{0};
 244   stat_t ruleNXDomain{0};
 245   stat_t ruleRefused{0};
 246   stat_t ruleServFail{0};
 247   stat_t selfAnswered{0};
 248   stat_t downstreamTimeouts{0};
 249   stat_t downstreamSendErrors{0};
 250   stat_t truncFail{0};
 251   stat_t noPolicy{0};
 252   stat_t cacheHits{0};
 253   stat_t cacheMisses{0};
 254   stat_t latency0_1{0}, latency1_10{0}, latency10_50{0}, latency50_100{0}, latency100_1000{0}, latencySlow{0};
 255   stat_t securityStatus{0};
 256
 257   double latencyAvg100{0}, latencyAvg1000{0}, latencyAvg10000{0}, latencyAvg1000000{0};
 258   typedef std::function<uint64_t(const std::string&)> statfunction_t;
 259   typedef boost::variant<stat_t*, double*, statfunction_t> entry_t;
 260   std::vector<std::pair<std::string, entry_t>> entries{
 261     {"responses", &responses},
 262     {"servfail-responses", &servfailResponses},
 263     {"queries", &queries},
 264     {"frontend-nxdomain", &frontendNXDomain},
 265     {"frontend-servfail", &frontendServFail},
 266     {"frontend-noerror", &frontendNoError},
 267     {"acl-drops", &aclDrops},
 268     {"rule-drop", &ruleDrop},
 269     {"rule-nxdomain", &ruleNXDomain},
 270     {"rule-refused", &ruleRefused},
 271     {"rule-servfail", &ruleServFail},
 272     {"self-answered", &selfAnswered},
 273     {"downstream-timeouts", &downstreamTimeouts},
 274     {"downstream-send-errors", &downstreamSendErrors},
 275     {"trunc-failures", &truncFail},
 276     {"no-policy", &noPolicy},
 277     {"latency0-1", &latency0_1},
 278     {"latency1-10", &latency1_10},
 279     {"latency10-50", &latency10_50},
 280     {"latency50-100", &latency50_100},
 281     {"latency100-1000", &latency100_1000},
 282     {"latency-slow", &latencySlow},
 283     {"latency-avg100", &latencyAvg100},
 284     {"latency-avg1000", &latencyAvg1000},
 285     {"latency-avg10000", &latencyAvg10000},
 286     {"latency-avg1000000", &latencyAvg1000000},
 287     {"uptime", uptimeOfProcess},
 288     {"real-memory-usage", getRealMemoryUsage},
 289     {"special-memory-usage", getSpecialMemoryUsage},
 290     {"noncompliant-queries", &nonCompliantQueries},
 291     {"noncompliant-responses", &nonCompliantResponses},
 292     {"rdqueries", &rdQueries},
 293     {"empty-queries", &emptyQueries},
 294     {"cache-hits", &cacheHits},
 295     {"cache-misses", &cacheMisses},
 296     {"cpu-user-msec", getCPUTimeUser},
 297     {"cpu-sys-msec", getCPUTimeSystem},
 298     {"fd-usage", getOpenFileDescriptors},
 299     {"dyn-blocked", &dynBlocked},
 300     {"dyn-block-nmg-size", [](const std::string&) { return g_dynblockNMG.getLocal()->size(); }},
 301     {"security-status", &securityStatus}
 302   };
 303 };
 304
 305 // Metric types for Prometheus
 306 enum class PrometheusMetricType: int {
 307     counter = 1,
 308     gauge = 2
 309 };
 310
 311 // Keeps additional information about metrics
 312 struct MetricDefinition {
 313   MetricDefinition(PrometheusMetricType _prometheusType, const std::string& _description): description(_description), prometheusType(_prometheusType) {
 314   }
 315
 316   MetricDefinition() = default;
 317
 318   // Metric description
 319   std::string description;
 320   // Metric type for Prometheus
 321   PrometheusMetricType prometheusType;
 322 };
 323
 324 struct MetricDefinitionStorage {
 325   // Return metric definition by name
 326   bool getMetricDetails(std::string metricName, MetricDefinition& metric) {
 327   auto metricDetailsIter = metrics.find(metricName);
 328
 329   if (metricDetailsIter == metrics.end()) {
 330     return false;
 331   }
 332
 333   metric = metricDetailsIter->second;
 334     return true;
 335   };
 336
 337   // Return string representation of Prometheus metric type
 338   std::string getPrometheusStringMetricType(PrometheusMetricType metricType) {
 339     switch (metricType) {
 340       case PrometheusMetricType::counter:
 341         return "counter";
 342         break;
 343       case PrometheusMetricType::gauge:
 344         return "gauge";
 345         break;
 346       default:
 347         return "";
 348         break;
 349     }
 350   };
 351
 352   std::map<std::string, MetricDefinition> metrics = {
 353     { "responses",              MetricDefinition(PrometheusMetricType::counter, "Number of responses received from backends") },
 354     { "servfail-responses",     MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers received from backends") },
 355     { "queries",                MetricDefinition(PrometheusMetricType::counter, "Number of received queries")},
 356     { "frontend-nxdomain",      MetricDefinition(PrometheusMetricType::counter, "Number of NXDomain answers sent to clients")},
 357     { "frontend-servfail",      MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers sent to clients")},
 358     { "frontend-noerror",       MetricDefinition(PrometheusMetricType::counter, "Number of NoError answers sent to clients")},
 359     { "acl-drops",              MetricDefinition(PrometheusMetricType::counter, "Number of packets dropped because of the ACL")},
 360     { "rule-drop",              MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because of a rule")},
 361     { "rule-nxdomain",          MetricDefinition(PrometheusMetricType::counter, "Number of NXDomain answers returned because of a rule")},
 362     { "rule-refused",           MetricDefinition(PrometheusMetricType::counter, "Number of Refused answers returned because of a rule")},
 363     { "rule-servfail",          MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers received because of a rule")},
 364     { "self-answered",          MetricDefinition(PrometheusMetricType::counter, "Number of self-answered responses")},
 365     { "downstream-timeouts",    MetricDefinition(PrometheusMetricType::counter, "Number of queries not answered in time by a backend")},
 366     { "downstream-send-errors", MetricDefinition(PrometheusMetricType::counter, "Number of errors when sending a query to a backend")},
 367     { "trunc-failures",         MetricDefinition(PrometheusMetricType::counter, "Number of errors encountered while truncating an answer")},
 368     { "no-policy",              MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because no server was available")},
 369     { "latency0-1",             MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in less than 1ms")},
 370     { "latency1-10",            MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 1-10 ms")},
 371     { "latency10-50",           MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 10-50 ms")},
 372     { "latency50-100",          MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 50-100 ms")},
 373     { "latency100-1000",        MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 100-1000 ms")},
 374     { "latency-slow",           MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in more than 1 second")},
 375     { "latency-avg100",         MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 100 packets")},
 376     { "latency-avg1000",        MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 1000 packets")},
 377     { "latency-avg10000",       MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 10000 packets")},
 378     { "latency-avg1000000",     MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 1000000 packets")},
 379     { "uptime",                 MetricDefinition(PrometheusMetricType::gauge,   "Uptime of the dnsdist process in seconds")},
 380     { "real-memory-usage",      MetricDefinition(PrometheusMetricType::gauge,   "Current memory usage in bytes")},
 381     { "noncompliant-queries",   MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped as non-compliant")},
 382     { "noncompliant-responses", MetricDefinition(PrometheusMetricType::counter, "Number of answers from a backend dropped as non-compliant")},
 383     { "rdqueries",              MetricDefinition(PrometheusMetricType::counter, "Number of received queries with the recursion desired bit set")},
 384     { "empty-queries",          MetricDefinition(PrometheusMetricType::counter, "Number of empty queries received from clients")},
 385     { "cache-hits",             MetricDefinition(PrometheusMetricType::counter, "Number of times an answer was retrieved from cache")},
 386     { "cache-misses",           MetricDefinition(PrometheusMetricType::counter, "Number of times an answer not found in the cache")},
 387     { "cpu-user-msec",          MetricDefinition(PrometheusMetricType::counter, "Milliseconds spent by dnsdist in the user state")},
 388     { "cpu-sys-msec",           MetricDefinition(PrometheusMetricType::counter, "Milliseconds spent by dnsdist in the system state")},
 389     { "fd-usage",               MetricDefinition(PrometheusMetricType::gauge,   "Number of currently used file descriptors")},
 390     { "dyn-blocked",            MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because of a dynamic block")},
 391     { "dyn-block-nmg-size",     MetricDefinition(PrometheusMetricType::gauge,   "Number of dynamic blocks entries") },
 392     { "security-status",        MetricDefinition(PrometheusMetricType::gauge,   "Security status of this software. 0=unknown, 1=OK, 2=upgrade recommended, 3=upgrade mandatory") },
 393   };
 394 };
 395
 396 extern MetricDefinitionStorage g_metricDefinitions;
 397 extern struct DNSDistStats g_stats;
 398 void doLatencyStats(double udiff);
 399
 400
 401 struct StopWatch
 402 {
 403   StopWatch(bool realTime=false): d_needRealTime(realTime)
 404   {
 405   }
 406   struct timespec d_start{0,0};
 407   bool d_needRealTime{false};
 408
 409   void start() {
 410     if(gettime(&d_start, d_needRealTime) < 0)
 411       unixDie("Getting timestamp");
 412
 413   }
 414
 415   void set(const struct timespec& from) {
 416     d_start = from;
 417   }
 418
 419   double udiff() const {
 420     struct timespec now;
 421     if(gettime(&now, d_needRealTime) < 0)
 422       unixDie("Getting timestamp");
 423
 424     return 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
 425   }
 426
 427   double udiffAndSet() {
 428     struct timespec now;
 429     if(gettime(&now, d_needRealTime) < 0)
 430       unixDie("Getting timestamp");
 431
 432     auto ret= 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
 433     d_start = now;
 434     return ret;
 435   }
 436
 437 };
 438
 439 class BasicQPSLimiter
 440 {
 441 public:
 442   BasicQPSLimiter()
 443   {
 444   }
 445
 446   BasicQPSLimiter(unsigned int burst): d_tokens(burst)
 447   {
 448     d_prev.start();
 449   }
 450
 451   bool check(unsigned int rate, unsigned int burst) const // this is not quite fair
 452   {
 453     auto delta = d_prev.udiffAndSet();
 454
 455     if(delta > 0.0) // time, frequently, does go backwards..
 456       d_tokens += 1.0 * rate * (delta/1000000.0);
 457
 458     if(d_tokens > burst) {
 459       d_tokens = burst;
 460     }
 461
 462     bool ret=false;
 463     if(d_tokens >= 1.0) { // we need this because burst=1 is weird otherwise
 464       ret=true;
 465       --d_tokens;
 466     }
 467
 468     return ret;
 469   }
 470
 471   bool seenSince(const struct timespec& cutOff) const
 472   {
 473     return cutOff < d_prev.d_start;
 474   }
 475
 476 protected:
 477   mutable StopWatch d_prev;
 478   mutable double d_tokens;
 479 };
 480
 481 class QPSLimiter : public BasicQPSLimiter
 482 {
 483 public:
 484   QPSLimiter(): BasicQPSLimiter()
 485   {
 486   }
 487
 488   QPSLimiter(unsigned int rate, unsigned int burst): BasicQPSLimiter(burst), d_rate(rate), d_burst(burst), d_passthrough(false)
 489   {
 490     d_prev.start();
 491   }
 492
 493   unsigned int getRate() const
 494   {
 495     return d_passthrough ? 0 : d_rate;
 496   }
 497
 498   int getPassed() const
 499   {
 500     return d_passed;
 501   }
 502
 503   int getBlocked() const
 504   {
 505     return d_blocked;
 506   }
 507
 508   bool check() const // this is not quite fair
 509   {
 510     if (d_passthrough) {
 511       return true;
 512     }
 513
 514     bool ret = BasicQPSLimiter::check(d_rate, d_burst);
 515     if (ret) {
 516       d_passed++;
 517     }
 518     else {
 519       d_blocked++;
 520     }
 521
 522     return ret;
 523   }
 524 private:
 525   mutable unsigned int d_passed{0};
 526   mutable unsigned int d_blocked{0};
 527   unsigned int d_rate;
 528   unsigned int d_burst;
 529   bool d_passthrough{true};
 530 };
 531
 532 struct ClientState;
 533
 534 struct IDState
 535 {
 536   IDState() : origFD(-1), sentTime(true), delayMsec(0), tempFailureTTL(boost::none) { origDest.sin4.sin_family = 0;}
 537   IDState(const IDState& orig): origRemote(orig.origRemote), origDest(orig.origDest), age(orig.age)
 538   {
 539     origFD.store(orig.origFD.load());
 540     origID = orig.origID;
 541     delayMsec = orig.delayMsec;
 542     tempFailureTTL = orig.tempFailureTTL;
 543   }
 544
 545   std::atomic<int> origFD;  // set to <0 to indicate this state is empty   // 4
 546
 547   ComboAddress origRemote;                                    // 28
 548   ComboAddress origDest;                                      // 28
 549   StopWatch sentTime;                                         // 16
 550   DNSName qname;                                              // 80
 551   std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
 552 #ifdef HAVE_PROTOBUF
 553   boost::optional<boost::uuids::uuid> uniqueId;
 554 #endif
 555   boost::optional<Netmask> subnet{boost::none};
 556   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
 557   std::shared_ptr<QTag> qTag{nullptr};
 558   const ClientState* cs{nullptr};
 559   DOHUnit* du{nullptr};
 560   uint32_t cacheKey;                                          // 4
 561   uint32_t cacheKeyNoECS;                                     // 4
 562   uint16_t age;                                               // 4
 563   uint16_t qtype;                                             // 2
 564   uint16_t qclass;                                            // 2
 565   uint16_t origID;                                            // 2
 566   uint16_t origFlags;                                         // 2
 567   int delayMsec;
 568   boost::optional<uint32_t> tempFailureTTL;
 569   bool ednsAdded{false};
 570   bool ecsAdded{false};
 571   bool skipCache{false};
 572   bool destHarvested{false}; // if true, origDest holds the original dest addr, otherwise the listening addr
 573   bool dnssecOK{false};
 574   bool useZeroScope;
 575 };
 576
 577 typedef std::unordered_map<string, unsigned int> QueryCountRecords;
 578 typedef std::function<std::tuple<bool, string>(const DNSQuestion* dq)> QueryCountFilter;
 579 struct QueryCount {
 580   QueryCount()
 581   {
 582     pthread_rwlock_init(&queryLock, nullptr);
 583   }
 584   QueryCountRecords records;
 585   QueryCountFilter filter;
 586   pthread_rwlock_t queryLock;
 587   bool enabled{false};
 588 };
 589
 590 extern QueryCount g_qcount;
 591
 592 struct ClientState
 593 {
 594   ClientState(const ComboAddress& local_, bool isTCP, bool doReusePort, int fastOpenQueue, const std::string& itfName, const std::set<int>& cpus_): cpus(cpus_), local(local_), interface(itfName), fastOpenQueueSize(fastOpenQueue), tcp(isTCP), reuseport(doReusePort)
 595   {
 596   }
 597
 598   std::set<int> cpus;
 599   ComboAddress local;
 600   std::shared_ptr<DNSCryptContext> dnscryptCtx{nullptr};
 601   std::shared_ptr<TLSFrontend> tlsFrontend{nullptr};
 602   std::shared_ptr<DOHFrontend> dohFrontend{nullptr};
 603   std::string interface;
 604   std::atomic<uint64_t> queries{0};
 605   std::atomic<uint64_t> tcpDiedReadingQuery{0};
 606   std::atomic<uint64_t> tcpDiedSendingResponse{0};
 607   std::atomic<uint64_t> tcpGaveUp{0};
 608   std::atomic<uint64_t> tcpClientTimeouts{0};
 609   std::atomic<uint64_t> tcpDownstreamTimeouts{0};
 610   std::atomic<uint64_t> tcpCurrentConnections{0};
 611   std::atomic<double> tcpAvgQueriesPerConnection{0.0};
 612   /* in ms */
 613   std::atomic<double> tcpAvgConnectionDuration{0.0};
 614   int udpFD{-1};
 615   int tcpFD{-1};
 616   int fastOpenQueueSize{0};
 617   bool muted{false};
 618   bool tcp;
 619   bool reuseport;
 620   bool ready{false};
 621
 622   int getSocket() const
 623   {
 624     return udpFD != -1 ? udpFD : tcpFD;
 625   }
 626
 627   std::string getType() const
 628   {
 629     std::string result = udpFD != -1 ? "UDP" : "TCP";
 630
 631     if (dohFrontend) {
 632       result += " (DNS over HTTPS)";
 633     }
 634     else if (tlsFrontend) {
 635       result += " (DNS over TLS)";
 636     }
 637     else if (dnscryptCtx) {
 638       result += " (DNSCrypt)";
 639     }
 640
 641     return result;
 642   }
 643
 644 #ifdef HAVE_EBPF
 645   shared_ptr<BPFFilter> d_filter;
 646
 647   void detachFilter()
 648   {
 649     if (d_filter) {
 650       d_filter->removeSocket(getSocket());
 651       d_filter = nullptr;
 652     }
 653   }
 654
 655   void attachFilter(shared_ptr<BPFFilter> bpf)
 656   {
 657     detachFilter();
 658
 659     bpf->addSocket(getSocket());
 660     d_filter = bpf;
 661   }
 662 #endif /* HAVE_EBPF */
 663
 664   void updateTCPMetrics(size_t queries, uint64_t durationMs)
 665   {
 666     tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (queries / 100.0);
 667     tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
 668   }
 669 };
 670
 671 class TCPClientCollection {
 672   std::vector<int> d_tcpclientthreads;
 673   std::atomic<uint64_t> d_numthreads{0};
 674   std::atomic<uint64_t> d_pos{0};
 675   std::atomic<uint64_t> d_queued{0};
 676   const uint64_t d_maxthreads{0};
 677   std::mutex d_mutex;
 678   int d_singlePipe[2];
 679   const bool d_useSinglePipe;
 680 public:
 681
 682   TCPClientCollection(size_t maxThreads, bool useSinglePipe=false): d_maxthreads(maxThreads), d_singlePipe{-1,-1}, d_useSinglePipe(useSinglePipe)
 683
 684   {
 685     d_tcpclientthreads.reserve(maxThreads);
 686
 687     if (d_useSinglePipe) {
 688       if (pipe(d_singlePipe) < 0) {
 689         throw std::runtime_error("Error creating the TCP single communication pipe: " + string(strerror(errno)));
 690       }
 691
 692       if (!setNonBlocking(d_singlePipe[0])) {
 693         int err = errno;
 694         close(d_singlePipe[0]);
 695         close(d_singlePipe[1]);
 696         throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + string(strerror(err)));
 697       }
 698
 699       if (!setNonBlocking(d_singlePipe[1])) {
 700         int err = errno;
 701         close(d_singlePipe[0]);
 702         close(d_singlePipe[1]);
 703         throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + string(strerror(err)));
 704       }
 705     }
 706   }
 707   int getThread()
 708   {
 709     uint64_t pos = d_pos++;
 710     ++d_queued;
 711     return d_tcpclientthreads[pos % d_numthreads];
 712   }
 713   bool hasReachedMaxThreads() const
 714   {
 715     return d_numthreads >= d_maxthreads;
 716   }
 717   uint64_t getThreadsCount() const
 718   {
 719     return d_numthreads;
 720   }
 721   uint64_t getQueuedCount() const
 722   {
 723     return d_queued;
 724   }
 725   void decrementQueuedCount()
 726   {
 727     --d_queued;
 728   }
 729   void addTCPClientThread();
 730 };
 731
 732 extern std::unique_ptr<TCPClientCollection> g_tcpclientthreads;
 733
 734 struct DownstreamState
 735 {
 736    typedef std::function<std::tuple<DNSName, uint16_t, uint16_t>(const DNSName&, uint16_t, uint16_t, dnsheader*)> checkfunc_t;
 737
 738   DownstreamState(const ComboAddress& remote_, const ComboAddress& sourceAddr_, unsigned int sourceItf, size_t numberOfSockets);
 739   DownstreamState(const ComboAddress& remote_): DownstreamState(remote_, ComboAddress(), 0, 1) {}
 740   ~DownstreamState()
 741   {
 742     for (auto& fd : sockets) {
 743       if (fd >= 0) {
 744         close(fd);
 745         fd = -1;
 746       }
 747     }
 748   }
 749   boost::uuids::uuid id;
 750   std::set<unsigned int> hashes;
 751   mutable pthread_rwlock_t d_lock;
 752   std::vector<int> sockets;
 753   std::mutex socketsLock;
 754   std::mutex connectLock;
 755   std::unique_ptr<FDMultiplexer> mplexer{nullptr};
 756   std::thread tid;
 757   const ComboAddress remote;
 758   QPSLimiter qps;
 759   vector<IDState> idStates;
 760   const ComboAddress sourceAddr;
 761   checkfunc_t checkFunction;
 762   DNSName checkName{"a.root-servers.net."};
 763   QType checkType{QType::A};
 764   uint16_t checkClass{QClass::IN};
 765   std::atomic<uint64_t> idOffset{0};
 766   std::atomic<uint64_t> sendErrors{0};
 767   std::atomic<uint64_t> outstanding{0};
 768   std::atomic<uint64_t> reuseds{0};
 769   std::atomic<uint64_t> queries{0};
 770   struct {
 771     std::atomic<uint64_t> sendErrors{0};
 772     std::atomic<uint64_t> reuseds{0};
 773     std::atomic<uint64_t> queries{0};
 774   } prev;
 775   std::atomic<uint64_t> tcpDiedSendingQuery{0};
 776   std::atomic<uint64_t> tcpDiedReadingResponse{0};
 777   std::atomic<uint64_t> tcpGaveUp{0};
 778   std::atomic<uint64_t> tcpReadTimeouts{0};
 779   std::atomic<uint64_t> tcpWriteTimeouts{0};
 780   std::atomic<uint64_t> tcpCurrentConnections{0};
 781   std::atomic<double> tcpAvgQueriesPerConnection{0.0};
 782   /* in ms */
 783   std::atomic<double> tcpAvgConnectionDuration{0.0};
 784   string name;
 785   size_t socketsOffset{0};
 786   double queryLoad{0.0};
 787   double dropRate{0.0};
 788   double latencyUsec{0.0};
 789   int order{1};
 790   int weight{1};
 791   int tcpConnectTimeout{5};
 792   int tcpRecvTimeout{30};
 793   int tcpSendTimeout{30};
 794   unsigned int checkInterval{1};
 795   unsigned int lastCheck{0};
 796   const unsigned int sourceItf{0};
 797   uint16_t retries{5};
 798   uint16_t xpfRRCode{0};
 799   uint16_t checkTimeout{1000}; /* in milliseconds */
 800   uint8_t currentCheckFailures{0};
 801   uint8_t consecutiveSuccessfulChecks{0};
 802   uint8_t maxCheckFailures{1};
 803   uint8_t minRiseSuccesses{1};
 804   StopWatch sw;
 805   set<string> pools;
 806   enum class Availability { Up, Down, Auto} availability{Availability::Auto};
 807   bool mustResolve{false};
 808   bool upStatus{false};
 809   bool useECS{false};
 810   bool setCD{false};
 811   bool disableZeroScope{false};
 812   std::atomic<bool> connected{false};
 813   std::atomic_flag threadStarted;
 814   bool tcpFastOpen{false};
 815   bool ipBindAddrNoPort{true};
 816
 817   bool isUp() const
 818   {
 819     if(availability == Availability::Down)
 820       return false;
 821     if(availability == Availability::Up)
 822       return true;
 823     return upStatus;
 824   }
 825   void setUp() { availability = Availability::Up; }
 826   void setDown() { availability = Availability::Down; }
 827   void setAuto() { availability = Availability::Auto; }
 828   string getName() const {
 829     if (name.empty()) {
 830       return remote.toStringWithPort();
 831     }
 832     return name;
 833   }
 834   string getNameWithAddr() const {
 835     if (name.empty()) {
 836       return remote.toStringWithPort();
 837     }
 838     return name + " (" + remote.toStringWithPort()+ ")";
 839   }
 840   string getStatus() const
 841   {
 842     string status;
 843     if(availability == DownstreamState::Availability::Up)
 844       status = "UP";
 845     else if(availability == DownstreamState::Availability::Down)
 846       status = "DOWN";
 847     else
 848       status = (upStatus ? "up" : "down");
 849     return status;
 850   }
 851   bool reconnect();
 852   void hash();
 853   void setId(const boost::uuids::uuid& newId);
 854   void setWeight(int newWeight);
 855
 856   void updateTCPMetrics(size_t queries, uint64_t durationMs)
 857   {
 858     tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (queries / 100.0);
 859     tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
 860   }
 861 };
 862 using servers_t =vector<std::shared_ptr<DownstreamState>>;
 863
 864 template <class T> using NumberedVector = std::vector<std::pair<unsigned int, T> >;
 865
 866 void responderThread(std::shared_ptr<DownstreamState> state);
 867 extern std::mutex g_luamutex;
 868 extern LuaContext g_lua;
 869 extern std::string g_outputBuffer; // locking for this is ok, as locked by g_luamutex
 870
 871 class DNSRule
 872 {
 873 public:
 874   virtual ~DNSRule ()
 875   {
 876   }
 877   virtual bool matches(const DNSQuestion* dq) const =0;
 878   virtual string toString() const = 0;
 879   mutable std::atomic<uint64_t> d_matches{0};
 880 };
 881
 882 using NumberedServerVector = NumberedVector<shared_ptr<DownstreamState>>;
 883 typedef std::function<shared_ptr<DownstreamState>(const NumberedServerVector& servers, const DNSQuestion*)> policyfunc_t;
 884
 885 struct ServerPolicy
 886 {
 887   string name;
 888   policyfunc_t policy;
 889   bool isLua;
 890   std::string toString() const {
 891     return string("ServerPolicy") + (isLua ? " (Lua)" : "") + " \"" + name + "\"";
 892   }
 893 };
 894
 895 struct ServerPool
 896 {
 897   ServerPool()
 898   {
 899     pthread_rwlock_init(&d_lock, nullptr);
 900   }
 901
 902   const std::shared_ptr<DNSDistPacketCache> getCache() const { return packetCache; };
 903
 904   bool getECS() const
 905   {
 906     return d_useECS;
 907   }
 908
 909   void setECS(bool useECS)
 910   {
 911     d_useECS = useECS;
 912   }
 913
 914   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
 915   std::shared_ptr<ServerPolicy> policy{nullptr};
 916
 917   size_t countServers(bool upOnly)
 918   {
 919     size_t count = 0;
 920     ReadLock rl(&d_lock);
 921     for (const auto& server : d_servers) {
 922       if (!upOnly || std::get<1>(server)->isUp() ) {
 923         count++;
 924       }
 925     }
 926     return count;
 927   }
 928
 929   NumberedVector<shared_ptr<DownstreamState>> getServers()
 930   {
 931     NumberedVector<shared_ptr<DownstreamState>> result;
 932     {
 933       ReadLock rl(&d_lock);
 934       result = d_servers;
 935     }
 936     return result;
 937   }
 938
 939   void addServer(shared_ptr<DownstreamState>& server)
 940   {
 941     WriteLock wl(&d_lock);
 942     unsigned int count = (unsigned int) d_servers.size();
 943     d_servers.push_back(make_pair(++count, server));
 944     /* we need to reorder based on the server 'order' */
 945     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) {
 946       return a.second->order < b.second->order;
 947     });
 948     /* and now we need to renumber for Lua (custom policies) */
 949     size_t idx = 1;
 950     for (auto& serv : d_servers) {
 951       serv.first = idx++;
 952     }
 953   }
 954
 955   void removeServer(shared_ptr<DownstreamState>& server)
 956   {
 957     WriteLock wl(&d_lock);
 958     size_t idx = 1;
 959     bool found = false;
 960     for (auto it = d_servers.begin(); it != d_servers.end();) {
 961       if (found) {
 962         /* we need to renumber the servers placed
 963            after the removed one, for Lua (custom policies) */
 964         it->first = idx++;
 965         it++;
 966       }
 967       else if (it->second == server) {
 968         it = d_servers.erase(it);
 969         found = true;
 970       } else {
 971         idx++;
 972         it++;
 973       }
 974     }
 975   }
 976
 977 private:
 978   NumberedVector<shared_ptr<DownstreamState>> d_servers;
 979   pthread_rwlock_t d_lock;
 980   bool d_useECS{false};
 981 };
 982 using pools_t=map<std::string,std::shared_ptr<ServerPool>>;
 983 void setPoolPolicy(pools_t& pools, const string& poolName, std::shared_ptr<ServerPolicy> policy);
 984 void addServerToPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
 985 void removeServerFromPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
 986
 987 struct CarbonConfig
 988 {
 989   ComboAddress server;
 990   std::string namespace_name;
 991   std::string ourname;
 992   std::string instance_name;
 993   unsigned int interval;
 994 };
 995
 996 enum ednsHeaderFlags {
 997   EDNS_HEADER_FLAG_NONE = 0,
 998   EDNS_HEADER_FLAG_DO = 32768
 999 };
1000
1001 struct DNSDistRuleAction
1002 {
1003   std::shared_ptr<DNSRule> d_rule;
1004   std::shared_ptr<DNSAction> d_action;
1005   boost::uuids::uuid d_id;
1006   uint64_t d_creationOrder;
1007 };
1008
1009 struct DNSDistResponseRuleAction
1010 {
1011   std::shared_ptr<DNSRule> d_rule;
1012   std::shared_ptr<DNSResponseAction> d_action;
1013   boost::uuids::uuid d_id;
1014   uint64_t d_creationOrder;
1015 };
1016
1017 extern GlobalStateHolder<SuffixMatchTree<DynBlock>> g_dynblockSMT;
1018 extern DNSAction::Action g_dynBlockAction;
1019
1020 extern GlobalStateHolder<vector<CarbonConfig> > g_carbon;
1021 extern GlobalStateHolder<ServerPolicy> g_policy;
1022 extern GlobalStateHolder<servers_t> g_dstates;
1023 extern GlobalStateHolder<pools_t> g_pools;
1024 extern GlobalStateHolder<vector<DNSDistRuleAction> > g_rulactions;
1025 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_resprulactions;
1026 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_cachehitresprulactions;
1027 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_selfansweredresprulactions;
1028 extern GlobalStateHolder<NetmaskGroup> g_ACL;
1029
1030 extern ComboAddress g_serverControl; // not changed during runtime
1031
1032 extern std::vector<std::tuple<ComboAddress, bool, bool, int, std::string, std::set<int>>> g_locals; // not changed at runtime (we hope XXX)
1033 extern std::vector<shared_ptr<TLSFrontend>> g_tlslocals;
1034 extern std::vector<shared_ptr<DOHFrontend>> g_dohlocals;
1035 extern std::vector<std::unique_ptr<ClientState>> g_frontends;
1036 extern bool g_truncateTC;
1037 extern bool g_fixupCase;
1038 extern int g_tcpRecvTimeout;
1039 extern int g_tcpSendTimeout;
1040 extern int g_udpTimeout;
1041 extern uint16_t g_maxOutstanding;
1042 extern std::atomic<bool> g_configurationDone;
1043 extern uint64_t g_maxTCPClientThreads;
1044 extern uint64_t g_maxTCPQueuedConnections;
1045 extern size_t g_maxTCPQueriesPerConn;
1046 extern size_t g_maxTCPConnectionDuration;
1047 extern size_t g_maxTCPConnectionsPerClient;
1048 extern std::atomic<uint16_t> g_cacheCleaningDelay;
1049 extern std::atomic<uint16_t> g_cacheCleaningPercentage;
1050 extern bool g_verboseHealthChecks;
1051 extern uint32_t g_staleCacheEntriesTTL;
1052 extern bool g_apiReadWrite;
1053 extern std::string g_apiConfigDirectory;
1054 extern bool g_servFailOnNoPolicy;
1055 extern uint32_t g_hashperturb;
1056 extern bool g_useTCPSinglePipe;
1057 extern uint16_t g_downstreamTCPCleanupInterval;
1058 extern size_t g_udpVectorSize;
1059 extern bool g_preserveTrailingData;
1060 extern bool g_allowEmptyResponse;
1061 extern bool g_roundrobinFailOnNoServer;
1062
1063 #ifdef HAVE_EBPF
1064 extern shared_ptr<BPFFilter> g_defaultBPFFilter;
1065 extern std::vector<std::shared_ptr<DynBPFFilter> > g_dynBPFFilters;
1066 #endif /* HAVE_EBPF */
1067
1068 struct LocalHolders
1069 {
1070   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())
1071   {
1072   }
1073
1074   LocalStateHolder<NetmaskGroup> acl;
1075   LocalStateHolder<ServerPolicy> policy;
1076   LocalStateHolder<vector<DNSDistRuleAction> > rulactions;
1077   LocalStateHolder<vector<DNSDistResponseRuleAction> > cacheHitRespRulactions;
1078   LocalStateHolder<vector<DNSDistResponseRuleAction> > selfAnsweredRespRulactions;
1079   LocalStateHolder<servers_t> servers;
1080   LocalStateHolder<NetmaskTree<DynBlock> > dynNMGBlock;
1081   LocalStateHolder<SuffixMatchTree<DynBlock> > dynSMTBlock;
1082   LocalStateHolder<pools_t> pools;
1083 };
1084
1085 struct dnsheader;
1086
1087 void controlThread(int fd, ComboAddress local);
1088 vector<std::function<void(void)>> setupLua(bool client, const std::string& config);
1089 std::shared_ptr<ServerPool> getPool(const pools_t& pools, const std::string& poolName);
1090 std::shared_ptr<ServerPool> createPoolIfNotExists(pools_t& pools, const string& poolName);
1091 NumberedServerVector getDownstreamCandidates(const pools_t& pools, const std::string& poolName);
1092
1093 std::shared_ptr<DownstreamState> firstAvailable(const NumberedServerVector& servers, const DNSQuestion* dq);
1094
1095 std::shared_ptr<DownstreamState> leastOutstanding(const NumberedServerVector& servers, const DNSQuestion* dq);
1096 std::shared_ptr<DownstreamState> wrandom(const NumberedServerVector& servers, const DNSQuestion* dq);
1097 std::shared_ptr<DownstreamState> whashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1098 std::shared_ptr<DownstreamState> chashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1099 std::shared_ptr<DownstreamState> roundrobin(const NumberedServerVector& servers, const DNSQuestion* dq);
1100
1101 struct WebserverConfig
1102 {
1103   std::string password;
1104   std::string apiKey;
1105   boost::optional<std::map<std::string, std::string> > customHeaders;
1106   std::mutex lock;
1107 };
1108
1109 void setWebserverAPIKey(const boost::optional<std::string> apiKey);
1110 void setWebserverPassword(const std::string& password);
1111 void setWebserverCustomHeaders(const boost::optional<std::map<std::string, std::string> > customHeaders);
1112
1113 void dnsdistWebserverThread(int sock, const ComboAddress& local);
1114 void tcpAcceptorThread(void* p);
1115 #ifdef HAVE_DNS_OVER_HTTPS
1116 void dohThread(ClientState* cs);
1117 #endif /* HAVE_DNS_OVER_HTTPS */
1118
1119 void setLuaNoSideEffect(); // if nothing has been declared, set that there are no side effects
1120 void setLuaSideEffect();   // set to report a side effect, cancelling all _no_ side effect calls
1121 bool getLuaNoSideEffect(); // set if there were only explicit declarations of _no_ side effect
1122 void resetLuaSideEffect(); // reset to indeterminate state
1123
1124 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);
1125 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);
1126
1127 bool checkQueryHeaders(const struct dnsheader* dh);
1128
1129 extern std::vector<std::shared_ptr<DNSCryptContext>> g_dnsCryptLocals;
1130 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);
1131 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);
1132
1133 bool addXPF(DNSQuestion& dq, uint16_t optionCode);
1134
1135 uint16_t getRandomDNSID();
1136
1137 #include "dnsdist-snmp.hh"
1138
1139 extern bool g_snmpEnabled;
1140 extern bool g_snmpTrapsEnabled;
1141 extern DNSDistSNMPAgent* g_snmpAgent;
1142 extern bool g_addEDNSToSelfGeneratedResponses;
1143
1144 static const size_t s_udpIncomingBufferSize{1500};
1145
1146 enum class ProcessQueryResult { Drop, SendAnswer, PassToBackend };
1147 ProcessQueryResult processQuery(DNSQuestion& dq, ClientState& cs, LocalHolders& holders, std::shared_ptr<DownstreamState>& selectedBackend);
1148
1149 DNSResponse makeDNSResponseFromIDState(IDState& ids, struct dnsheader* dh, size_t bufferSize, uint16_t responseLen, bool isTCP);
1150 void setIDStateFromDNSQuestion(IDState& ids, DNSQuestion& dq, DNSName&& qname);
1151
1152 int pickBackendSocketForSending(std::shared_ptr<DownstreamState>& state);
1153 ssize_t udpClientSendRequestToBackend(const std::shared_ptr<DownstreamState>& ss, const int sd, const char* request, const size_t requestLen, bool healthCheck=false);