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/variant.hpp>
  35
  36 #include "bpf-filter.hh"
  37 #include "capabilities.hh"
  38 #include "circular_buffer.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   std::string poolname;
  80   const DNSName* qname{nullptr};
  81   const ComboAddress* local{nullptr};
  82   const ComboAddress* remote{nullptr};
  83   std::shared_ptr<QTag> qTag{nullptr};
  84   std::shared_ptr<std::map<uint16_t, EDNSOptionView> > ednsOptions;
  85   std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
  86   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
  87   struct dnsheader* dh{nullptr};
  88   const struct timespec* queryTime{nullptr};
  89   struct DOHUnit* du{nullptr};
  90   size_t size;
  91   unsigned int consumed{0};
  92   int delayMsec{0};
  93   boost::optional<uint32_t> tempFailureTTL;
  94   uint32_t cacheKeyNoECS;
  95   uint32_t cacheKey;
  96   const uint16_t qtype;
  97   const uint16_t qclass;
  98   uint16_t len;
  99   uint16_t ecsPrefixLength;
 100   uint16_t origFlags;
 101   uint8_t ednsRCode{0};
 102   const bool tcp;
 103   bool skipCache{false};
 104   bool ecsOverride;
 105   bool useECS{true};
 106   bool addXPF{true};
 107   bool ecsSet{false};
 108   bool ecsAdded{false};
 109   bool ednsAdded{false};
 110   bool useZeroScope{false};
 111   bool dnssecOK{false};
 112 };
 113
 114 struct DNSResponse : DNSQuestion
 115 {
 116   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_):
 117     DNSQuestion(name, type, class_, consumed, lc, rem, header, bufferSize, responseLen, isTcp, queryTime_) { }
 118   DNSResponse(const DNSResponse&) = delete;
 119   DNSResponse& operator=(const DNSResponse&) = delete;
 120   DNSResponse(DNSResponse&&) = default;
 121 };
 122
 123 /* so what could you do:
 124    drop,
 125    fake up nxdomain,
 126    provide actual answer,
 127    allow & and stop processing,
 128    continue processing,
 129    modify header:    (servfail|refused|notimp), set TC=1,
 130    send to pool */
 131
 132 class DNSAction
 133 {
 134 public:
 135   enum class Action { Drop, Nxdomain, Refused, Spoof, Allow, HeaderModify, Pool, Delay, Truncate, ServFail, None, NoOp, NoRecurse };
 136   static std::string typeToString(const Action& action)
 137   {
 138     switch(action) {
 139     case Action::Drop:
 140       return "Drop";
 141     case Action::Nxdomain:
 142       return "Send NXDomain";
 143     case Action::Refused:
 144       return "Send Refused";
 145     case Action::Spoof:
 146       return "Spoof an answer";
 147     case Action::Allow:
 148       return "Allow";
 149     case Action::HeaderModify:
 150       return "Modify the header";
 151     case Action::Pool:
 152       return "Route to a pool";
 153     case Action::Delay:
 154       return "Delay";
 155     case Action::Truncate:
 156       return "Truncate over UDP";
 157     case Action::ServFail:
 158       return "Send ServFail";
 159     case Action::None:
 160     case Action::NoOp:
 161       return "Do nothing";
 162     case Action::NoRecurse:
 163       return "Set rd=0";
 164     }
 165
 166     return "Unknown";
 167   }
 168
 169   virtual Action operator()(DNSQuestion*, string* ruleresult) const =0;
 170   virtual ~DNSAction()
 171   {
 172   }
 173   virtual string toString() const = 0;
 174   virtual std::map<string, double> getStats() const
 175   {
 176     return {{}};
 177   }
 178 };
 179
 180 class DNSResponseAction
 181 {
 182 public:
 183   enum class Action { Allow, Delay, Drop, HeaderModify, ServFail, None };
 184   virtual Action operator()(DNSResponse*, string* ruleresult) const =0;
 185   virtual ~DNSResponseAction()
 186   {
 187   }
 188   virtual string toString() const = 0;
 189 };
 190
 191 struct DynBlock
 192 {
 193   DynBlock(): action(DNSAction::Action::None), warning(false)
 194   {
 195   }
 196
 197   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)
 198   {
 199   }
 200
 201   DynBlock(const DynBlock& rhs): reason(rhs.reason), until(rhs.until), domain(rhs.domain), action(rhs.action), warning(rhs.warning)
 202   {
 203     blocks.store(rhs.blocks);
 204   }
 205
 206   DynBlock& operator=(const DynBlock& rhs)
 207   {
 208     reason=rhs.reason;
 209     until=rhs.until;
 210     domain=rhs.domain;
 211     action=rhs.action;
 212     blocks.store(rhs.blocks);
 213     warning=rhs.warning;
 214     return *this;
 215   }
 216
 217   string reason;
 218   struct timespec until;
 219   DNSName domain;
 220   DNSAction::Action action;
 221   mutable std::atomic<unsigned int> blocks;
 222   bool warning;
 223 };
 224
 225 extern GlobalStateHolder<NetmaskTree<DynBlock>> g_dynblockNMG;
 226
 227 extern vector<pair<struct timeval, std::string> > g_confDelta;
 228
 229 extern uint64_t getLatencyCount(const std::string&);
 230
 231 struct DNSDistStats
 232 {
 233   using stat_t=std::atomic<uint64_t>; // aww yiss ;-)
 234   stat_t responses{0};
 235   stat_t servfailResponses{0};
 236   stat_t queries{0};
 237   stat_t frontendNXDomain{0};
 238   stat_t frontendServFail{0};
 239   stat_t frontendNoError{0};
 240   stat_t nonCompliantQueries{0};
 241   stat_t nonCompliantResponses{0};
 242   stat_t rdQueries{0};
 243   stat_t emptyQueries{0};
 244   stat_t aclDrops{0};
 245   stat_t dynBlocked{0};
 246   stat_t ruleDrop{0};
 247   stat_t ruleNXDomain{0};
 248   stat_t ruleRefused{0};
 249   stat_t ruleServFail{0};
 250   stat_t selfAnswered{0};
 251   stat_t downstreamTimeouts{0};
 252   stat_t downstreamSendErrors{0};
 253   stat_t truncFail{0};
 254   stat_t noPolicy{0};
 255   stat_t cacheHits{0};
 256   stat_t cacheMisses{0};
 257   stat_t latency0_1{0}, latency1_10{0}, latency10_50{0}, latency50_100{0}, latency100_1000{0}, latencySlow{0}, latencySum{0};
 258   stat_t securityStatus{0};
 259
 260   double latencyAvg100{0}, latencyAvg1000{0}, latencyAvg10000{0}, latencyAvg1000000{0};
 261   typedef std::function<uint64_t(const std::string&)> statfunction_t;
 262   typedef boost::variant<stat_t*, double*, statfunction_t> entry_t;
 263   std::vector<std::pair<std::string, entry_t>> entries{
 264     {"responses", &responses},
 265     {"servfail-responses", &servfailResponses},
 266     {"queries", &queries},
 267     {"frontend-nxdomain", &frontendNXDomain},
 268     {"frontend-servfail", &frontendServFail},
 269     {"frontend-noerror", &frontendNoError},
 270     {"acl-drops", &aclDrops},
 271     {"rule-drop", &ruleDrop},
 272     {"rule-nxdomain", &ruleNXDomain},
 273     {"rule-refused", &ruleRefused},
 274     {"rule-servfail", &ruleServFail},
 275     {"self-answered", &selfAnswered},
 276     {"downstream-timeouts", &downstreamTimeouts},
 277     {"downstream-send-errors", &downstreamSendErrors},
 278     {"trunc-failures", &truncFail},
 279     {"no-policy", &noPolicy},
 280     {"latency0-1", &latency0_1},
 281     {"latency1-10", &latency1_10},
 282     {"latency10-50", &latency10_50},
 283     {"latency50-100", &latency50_100},
 284     {"latency100-1000", &latency100_1000},
 285     {"latency-slow", &latencySlow},
 286     {"latency-avg100", &latencyAvg100},
 287     {"latency-avg1000", &latencyAvg1000},
 288     {"latency-avg10000", &latencyAvg10000},
 289     {"latency-avg1000000", &latencyAvg1000000},
 290     {"uptime", uptimeOfProcess},
 291     {"real-memory-usage", getRealMemoryUsage},
 292     {"special-memory-usage", getSpecialMemoryUsage},
 293     {"noncompliant-queries", &nonCompliantQueries},
 294     {"noncompliant-responses", &nonCompliantResponses},
 295     {"rdqueries", &rdQueries},
 296     {"empty-queries", &emptyQueries},
 297     {"cache-hits", &cacheHits},
 298     {"cache-misses", &cacheMisses},
 299     {"cpu-user-msec", getCPUTimeUser},
 300     {"cpu-sys-msec", getCPUTimeSystem},
 301     {"fd-usage", getOpenFileDescriptors},
 302     {"dyn-blocked", &dynBlocked},
 303     {"dyn-block-nmg-size", [](const std::string&) { return g_dynblockNMG.getLocal()->size(); }},
 304     {"security-status", &securityStatus},
 305     // Latency histogram
 306     {"latency-sum", &latencySum},
 307     {"latency-count", getLatencyCount},
 308   };
 309 };
 310
 311 // Metric types for Prometheus
 312 enum class PrometheusMetricType: int {
 313     counter = 1,
 314     gauge = 2
 315 };
 316
 317 // Keeps additional information about metrics
 318 struct MetricDefinition {
 319   MetricDefinition(PrometheusMetricType _prometheusType, const std::string& _description): description(_description), prometheusType(_prometheusType) {
 320   }
 321
 322   MetricDefinition() = default;
 323
 324   // Metric description
 325   std::string description;
 326   // Metric type for Prometheus
 327   PrometheusMetricType prometheusType;
 328 };
 329
 330 struct MetricDefinitionStorage {
 331   // Return metric definition by name
 332   bool getMetricDetails(std::string metricName, MetricDefinition& metric) {
 333   auto metricDetailsIter = metrics.find(metricName);
 334
 335   if (metricDetailsIter == metrics.end()) {
 336     return false;
 337   }
 338
 339   metric = metricDetailsIter->second;
 340     return true;
 341   };
 342
 343   // Return string representation of Prometheus metric type
 344   std::string getPrometheusStringMetricType(PrometheusMetricType metricType) {
 345     switch (metricType) {
 346       case PrometheusMetricType::counter:
 347         return "counter";
 348         break;
 349       case PrometheusMetricType::gauge:
 350         return "gauge";
 351         break;
 352       default:
 353         return "";
 354         break;
 355     }
 356   };
 357
 358   std::map<std::string, MetricDefinition> metrics = {
 359     { "responses",              MetricDefinition(PrometheusMetricType::counter, "Number of responses received from backends") },
 360     { "servfail-responses",     MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers received from backends") },
 361     { "queries",                MetricDefinition(PrometheusMetricType::counter, "Number of received queries")},
 362     { "frontend-nxdomain",      MetricDefinition(PrometheusMetricType::counter, "Number of NXDomain answers sent to clients")},
 363     { "frontend-servfail",      MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers sent to clients")},
 364     { "frontend-noerror",       MetricDefinition(PrometheusMetricType::counter, "Number of NoError answers sent to clients")},
 365     { "acl-drops",              MetricDefinition(PrometheusMetricType::counter, "Number of packets dropped because of the ACL")},
 366     { "rule-drop",              MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because of a rule")},
 367     { "rule-nxdomain",          MetricDefinition(PrometheusMetricType::counter, "Number of NXDomain answers returned because of a rule")},
 368     { "rule-refused",           MetricDefinition(PrometheusMetricType::counter, "Number of Refused answers returned because of a rule")},
 369     { "rule-servfail",          MetricDefinition(PrometheusMetricType::counter, "Number of SERVFAIL answers received because of a rule")},
 370     { "self-answered",          MetricDefinition(PrometheusMetricType::counter, "Number of self-answered responses")},
 371     { "downstream-timeouts",    MetricDefinition(PrometheusMetricType::counter, "Number of queries not answered in time by a backend")},
 372     { "downstream-send-errors", MetricDefinition(PrometheusMetricType::counter, "Number of errors when sending a query to a backend")},
 373     { "trunc-failures",         MetricDefinition(PrometheusMetricType::counter, "Number of errors encountered while truncating an answer")},
 374     { "no-policy",              MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because no server was available")},
 375     { "latency0-1",             MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in less than 1ms")},
 376     { "latency1-10",            MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 1-10 ms")},
 377     { "latency10-50",           MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 10-50 ms")},
 378     { "latency50-100",          MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 50-100 ms")},
 379     { "latency100-1000",        MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in 100-1000 ms")},
 380     { "latency-slow",           MetricDefinition(PrometheusMetricType::counter, "Number of queries answered in more than 1 second")},
 381     { "latency-avg100",         MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 100 packets")},
 382     { "latency-avg1000",        MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 1000 packets")},
 383     { "latency-avg10000",       MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 10000 packets")},
 384     { "latency-avg1000000",     MetricDefinition(PrometheusMetricType::gauge,   "Average response latency in microseconds of the last 1000000 packets")},
 385     { "uptime",                 MetricDefinition(PrometheusMetricType::gauge,   "Uptime of the dnsdist process in seconds")},
 386     { "real-memory-usage",      MetricDefinition(PrometheusMetricType::gauge,   "Current memory usage in bytes")},
 387     { "noncompliant-queries",   MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped as non-compliant")},
 388     { "noncompliant-responses", MetricDefinition(PrometheusMetricType::counter, "Number of answers from a backend dropped as non-compliant")},
 389     { "rdqueries",              MetricDefinition(PrometheusMetricType::counter, "Number of received queries with the recursion desired bit set")},
 390     { "empty-queries",          MetricDefinition(PrometheusMetricType::counter, "Number of empty queries received from clients")},
 391     { "cache-hits",             MetricDefinition(PrometheusMetricType::counter, "Number of times an answer was retrieved from cache")},
 392     { "cache-misses",           MetricDefinition(PrometheusMetricType::counter, "Number of times an answer not found in the cache")},
 393     { "cpu-user-msec",          MetricDefinition(PrometheusMetricType::counter, "Milliseconds spent by dnsdist in the user state")},
 394     { "cpu-sys-msec",           MetricDefinition(PrometheusMetricType::counter, "Milliseconds spent by dnsdist in the system state")},
 395     { "fd-usage",               MetricDefinition(PrometheusMetricType::gauge,   "Number of currently used file descriptors")},
 396     { "dyn-blocked",            MetricDefinition(PrometheusMetricType::counter, "Number of queries dropped because of a dynamic block")},
 397     { "dyn-block-nmg-size",     MetricDefinition(PrometheusMetricType::gauge,   "Number of dynamic blocks entries") },
 398     { "security-status",        MetricDefinition(PrometheusMetricType::gauge,   "Security status of this software. 0=unknown, 1=OK, 2=upgrade recommended, 3=upgrade mandatory") },
 399   };
 400 };
 401
 402 extern MetricDefinitionStorage g_metricDefinitions;
 403 extern struct DNSDistStats g_stats;
 404 void doLatencyStats(double udiff);
 405
 406
 407 struct StopWatch
 408 {
 409   StopWatch(bool realTime=false): d_needRealTime(realTime)
 410   {
 411   }
 412   struct timespec d_start{0,0};
 413   bool d_needRealTime{false};
 414
 415   void start() {
 416     if(gettime(&d_start, d_needRealTime) < 0)
 417       unixDie("Getting timestamp");
 418
 419   }
 420
 421   void set(const struct timespec& from) {
 422     d_start = from;
 423   }
 424
 425   double udiff() const {
 426     struct timespec now;
 427     if(gettime(&now, d_needRealTime) < 0)
 428       unixDie("Getting timestamp");
 429
 430     return 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
 431   }
 432
 433   double udiffAndSet() {
 434     struct timespec now;
 435     if(gettime(&now, d_needRealTime) < 0)
 436       unixDie("Getting timestamp");
 437
 438     auto ret= 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
 439     d_start = now;
 440     return ret;
 441   }
 442
 443 };
 444
 445 class BasicQPSLimiter
 446 {
 447 public:
 448   BasicQPSLimiter()
 449   {
 450   }
 451
 452   BasicQPSLimiter(unsigned int burst): d_tokens(burst)
 453   {
 454     d_prev.start();
 455   }
 456
 457   bool check(unsigned int rate, unsigned int burst) const // this is not quite fair
 458   {
 459     auto delta = d_prev.udiffAndSet();
 460
 461     if(delta > 0.0) // time, frequently, does go backwards..
 462       d_tokens += 1.0 * rate * (delta/1000000.0);
 463
 464     if(d_tokens > burst) {
 465       d_tokens = burst;
 466     }
 467
 468     bool ret=false;
 469     if(d_tokens >= 1.0) { // we need this because burst=1 is weird otherwise
 470       ret=true;
 471       --d_tokens;
 472     }
 473
 474     return ret;
 475   }
 476
 477   bool seenSince(const struct timespec& cutOff) const
 478   {
 479     return cutOff < d_prev.d_start;
 480   }
 481
 482 protected:
 483   mutable StopWatch d_prev;
 484   mutable double d_tokens;
 485 };
 486
 487 class QPSLimiter : public BasicQPSLimiter
 488 {
 489 public:
 490   QPSLimiter(): BasicQPSLimiter()
 491   {
 492   }
 493
 494   QPSLimiter(unsigned int rate, unsigned int burst): BasicQPSLimiter(burst), d_rate(rate), d_burst(burst), d_passthrough(false)
 495   {
 496     d_prev.start();
 497   }
 498
 499   unsigned int getRate() const
 500   {
 501     return d_passthrough ? 0 : d_rate;
 502   }
 503
 504   int getPassed() const
 505   {
 506     return d_passed;
 507   }
 508
 509   int getBlocked() const
 510   {
 511     return d_blocked;
 512   }
 513
 514   bool check() const // this is not quite fair
 515   {
 516     if (d_passthrough) {
 517       return true;
 518     }
 519
 520     bool ret = BasicQPSLimiter::check(d_rate, d_burst);
 521     if (ret) {
 522       d_passed++;
 523     }
 524     else {
 525       d_blocked++;
 526     }
 527
 528     return ret;
 529   }
 530 private:
 531   mutable unsigned int d_passed{0};
 532   mutable unsigned int d_blocked{0};
 533   unsigned int d_rate;
 534   unsigned int d_burst;
 535   bool d_passthrough{true};
 536 };
 537
 538 struct ClientState;
 539
 540 struct IDState
 541 {
 542   IDState(): sentTime(true), delayMsec(0), tempFailureTTL(boost::none) { origDest.sin4.sin_family = 0;}
 543   IDState(const IDState& orig): origRemote(orig.origRemote), origDest(orig.origDest), age(orig.age)
 544   {
 545     usageIndicator.store(orig.usageIndicator.load());
 546     origFD = orig.origFD;
 547     origID = orig.origID;
 548     delayMsec = orig.delayMsec;
 549     tempFailureTTL = orig.tempFailureTTL;
 550   }
 551
 552   static const int64_t unusedIndicator = -1;
 553
 554   static bool isInUse(int64_t usageIndicator)
 555   {
 556     return usageIndicator != unusedIndicator;
 557   }
 558
 559   bool isInUse() const
 560   {
 561     return usageIndicator != unusedIndicator;
 562   }
 563
 564   /* return true if the value has been successfully replaced meaning that
 565      no-one updated the usage indicator in the meantime */
 566   bool tryMarkUnused(int64_t expectedUsageIndicator)
 567   {
 568     return usageIndicator.compare_exchange_strong(expectedUsageIndicator, unusedIndicator);
 569   }
 570
 571   /* mark as unused no matter what, return true if the state was in use before */
 572   bool markAsUsed()
 573   {
 574     auto currentGeneration = generation++;
 575     return markAsUsed(currentGeneration);
 576   }
 577
 578   /* mark as unused no matter what, return true if the state was in use before */
 579   bool markAsUsed(int64_t currentGeneration)
 580   {
 581     int64_t oldUsage = usageIndicator.exchange(currentGeneration);
 582     return oldUsage != unusedIndicator;
 583   }
 584
 585   /* We use this value to detect whether this state is in use.
 586      For performance reasons we don't want to use a lock here, but that means
 587      we need to be very careful when modifying this value. Modifications happen
 588      from:
 589      - one of the UDP or DoH 'client' threads receiving a query, selecting a backend
 590        then picking one of the states associated to this backend (via the idOffset).
 591        Most of the time this state should not be in use and usageIndicator is -1, but we
 592        might not yet have received a response for the query previously associated to this
 593        state, meaning that we will 'reuse' this state and erase the existing state.
 594        If we ever receive a response for this state, it will be discarded. This is
 595        mostly fine for UDP except that we still need to be careful in order to miss
 596        the 'outstanding' counters, which should only be increased when we are picking
 597        an empty state, and not when reusing ;
 598        For DoH, though, we have dynamically allocated a DOHUnit object that needs to
 599        be freed, as well as internal objects internals to libh2o.
 600      - one of the UDP receiver threads receiving a response from a backend, picking
 601        the corresponding state and sending the response to the client ;
 602      - the 'healthcheck' thread scanning the states to actively discover timeouts,
 603        mostly to keep some counters like the 'outstanding' one sane.
 604      We previously based that logic on the origFD (FD on which the query was received,
 605      and therefore from where the response should be sent) but this suffered from an
 606      ABA problem since it was quite likely that a UDP 'client thread' would reset it to the
 607      same value since we only have so much incoming sockets:
 608      - 1/ 'client' thread gets a query and set origFD to its FD, say 5 ;
 609      - 2/ 'receiver' thread gets a response, read the value of origFD to 5, check that the qname,
 610        qtype and qclass match
 611      - 3/ during that time the 'client' thread reuses the state, setting again origFD to 5 ;
 612      - 4/ the 'receiver' thread uses compare_exchange_strong() to only replace the value if it's still
 613        5, except it's not the same 5 anymore and it overrides a fresh state.
 614      We now use a 32-bit unsigned counter instead, which is incremented every time the state is set,
 615      wrapping around if necessary, and we set an atomic signed 64-bit value, so that we still have -1
 616      when the state is unused and the value of our counter otherwise.
 617   */
 618   std::atomic<int64_t> usageIndicator{unusedIndicator};  // set to unusedIndicator to indicate this state is empty   // 8
 619   std::atomic<uint32_t> generation{0}; // increased every time a state is used, to be able to detect an ABA issue    // 4
 620   ComboAddress origRemote;                                    // 28
 621   ComboAddress origDest;                                      // 28
 622   StopWatch sentTime;                                         // 16
 623   DNSName qname;                                              // 80
 624   std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
 625 #ifdef HAVE_PROTOBUF
 626   boost::optional<boost::uuids::uuid> uniqueId;
 627 #endif
 628   boost::optional<Netmask> subnet{boost::none};
 629   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
 630   std::shared_ptr<QTag> qTag{nullptr};
 631   const ClientState* cs{nullptr};
 632   DOHUnit* du{nullptr};
 633   uint32_t cacheKey;                                          // 4
 634   uint32_t cacheKeyNoECS;                                     // 4
 635   uint16_t age;                                               // 4
 636   uint16_t qtype;                                             // 2
 637   uint16_t qclass;                                            // 2
 638   uint16_t origID;                                            // 2
 639   uint16_t origFlags;                                         // 2
 640   int origFD{-1};
 641   int delayMsec;
 642   boost::optional<uint32_t> tempFailureTTL;
 643   bool ednsAdded{false};
 644   bool ecsAdded{false};
 645   bool skipCache{false};
 646   bool destHarvested{false}; // if true, origDest holds the original dest addr, otherwise the listening addr
 647   bool dnssecOK{false};
 648   bool useZeroScope;
 649 };
 650
 651 typedef std::unordered_map<string, unsigned int> QueryCountRecords;
 652 typedef std::function<std::tuple<bool, string>(const DNSQuestion* dq)> QueryCountFilter;
 653 struct QueryCount {
 654   QueryCount()
 655   {
 656     pthread_rwlock_init(&queryLock, nullptr);
 657   }
 658   QueryCountRecords records;
 659   QueryCountFilter filter;
 660   pthread_rwlock_t queryLock;
 661   bool enabled{false};
 662 };
 663
 664 extern QueryCount g_qcount;
 665
 666 struct ClientState
 667 {
 668   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)
 669   {
 670   }
 671
 672   std::set<int> cpus;
 673   ComboAddress local;
 674   std::shared_ptr<DNSCryptContext> dnscryptCtx{nullptr};
 675   std::shared_ptr<TLSFrontend> tlsFrontend{nullptr};
 676   std::shared_ptr<DOHFrontend> dohFrontend{nullptr};
 677   std::string interface;
 678   std::atomic<uint64_t> queries{0};
 679   mutable std::atomic<uint64_t> responses{0};
 680   std::atomic<uint64_t> tcpDiedReadingQuery{0};
 681   std::atomic<uint64_t> tcpDiedSendingResponse{0};
 682   std::atomic<uint64_t> tcpGaveUp{0};
 683   std::atomic<uint64_t> tcpClientTimeouts{0};
 684   std::atomic<uint64_t> tcpDownstreamTimeouts{0};
 685   std::atomic<uint64_t> tcpCurrentConnections{0};
 686   std::atomic<uint64_t> tlsNewSessions{0}; // A new TLS session has been negotiated, no resumption
 687   std::atomic<uint64_t> tlsResumptions{0}; // A TLS session has been resumed, either via session id or via a TLS ticket
 688
 689   std::atomic<double> tcpAvgQueriesPerConnection{0.0};
 690   /* in ms */
 691   std::atomic<double> tcpAvgConnectionDuration{0.0};
 692   int udpFD{-1};
 693   int tcpFD{-1};
 694   int fastOpenQueueSize{0};
 695   bool muted{false};
 696   bool tcp;
 697   bool reuseport;
 698   bool ready{false};
 699
 700   int getSocket() const
 701   {
 702     return udpFD != -1 ? udpFD : tcpFD;
 703   }
 704
 705   bool isUDP() const
 706   {
 707     return udpFD != -1;
 708   }
 709
 710   bool isTCP() const
 711   {
 712     return udpFD == -1;
 713   }
 714
 715   std::string getType() const
 716   {
 717     std::string result = udpFD != -1 ? "UDP" : "TCP";
 718
 719     if (dohFrontend) {
 720       result += " (DNS over HTTPS)";
 721     }
 722     else if (tlsFrontend) {
 723       result += " (DNS over TLS)";
 724     }
 725     else if (dnscryptCtx) {
 726       result += " (DNSCrypt)";
 727     }
 728
 729     return result;
 730   }
 731
 732 #ifdef HAVE_EBPF
 733   shared_ptr<BPFFilter> d_filter;
 734
 735   void detachFilter()
 736   {
 737     if (d_filter) {
 738       d_filter->removeSocket(getSocket());
 739       d_filter = nullptr;
 740     }
 741   }
 742
 743   void attachFilter(shared_ptr<BPFFilter> bpf)
 744   {
 745     detachFilter();
 746
 747     bpf->addSocket(getSocket());
 748     d_filter = bpf;
 749   }
 750 #endif /* HAVE_EBPF */
 751
 752   void updateTCPMetrics(size_t queries, uint64_t durationMs)
 753   {
 754     tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (queries / 100.0);
 755     tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
 756   }
 757 };
 758
 759 class TCPClientCollection {
 760   std::vector<int> d_tcpclientthreads;
 761   std::atomic<uint64_t> d_numthreads{0};
 762   std::atomic<uint64_t> d_pos{0};
 763   std::atomic<uint64_t> d_queued{0};
 764   const uint64_t d_maxthreads{0};
 765   std::mutex d_mutex;
 766   int d_singlePipe[2];
 767   const bool d_useSinglePipe;
 768 public:
 769
 770   TCPClientCollection(size_t maxThreads, bool useSinglePipe=false): d_maxthreads(maxThreads), d_singlePipe{-1,-1}, d_useSinglePipe(useSinglePipe)
 771
 772   {
 773     d_tcpclientthreads.reserve(maxThreads);
 774
 775     if (d_useSinglePipe) {
 776       if (pipe(d_singlePipe) < 0) {
 777         int err = errno;
 778         throw std::runtime_error("Error creating the TCP single communication pipe: " + stringerror(err));
 779       }
 780
 781       if (!setNonBlocking(d_singlePipe[0])) {
 782         int err = errno;
 783         close(d_singlePipe[0]);
 784         close(d_singlePipe[1]);
 785         throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + stringerror(err));
 786       }
 787
 788       if (!setNonBlocking(d_singlePipe[1])) {
 789         int err = errno;
 790         close(d_singlePipe[0]);
 791         close(d_singlePipe[1]);
 792         throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + stringerror(err));
 793       }
 794     }
 795   }
 796   int getThread()
 797   {
 798     uint64_t pos = d_pos++;
 799     ++d_queued;
 800     return d_tcpclientthreads[pos % d_numthreads];
 801   }
 802   bool hasReachedMaxThreads() const
 803   {
 804     return d_numthreads >= d_maxthreads;
 805   }
 806   uint64_t getThreadsCount() const
 807   {
 808     return d_numthreads;
 809   }
 810   uint64_t getQueuedCount() const
 811   {
 812     return d_queued;
 813   }
 814   void decrementQueuedCount()
 815   {
 816     --d_queued;
 817   }
 818   void addTCPClientThread();
 819 };
 820
 821 extern std::unique_ptr<TCPClientCollection> g_tcpclientthreads;
 822
 823 struct DownstreamState
 824 {
 825    typedef std::function<std::tuple<DNSName, uint16_t, uint16_t>(const DNSName&, uint16_t, uint16_t, dnsheader*)> checkfunc_t;
 826
 827   DownstreamState(const ComboAddress& remote_, const ComboAddress& sourceAddr_, unsigned int sourceItf, size_t numberOfSockets);
 828   DownstreamState(const ComboAddress& remote_): DownstreamState(remote_, ComboAddress(), 0, 1) {}
 829   ~DownstreamState()
 830   {
 831     for (auto& fd : sockets) {
 832       if (fd >= 0) {
 833         close(fd);
 834         fd = -1;
 835       }
 836     }
 837   }
 838   boost::uuids::uuid id;
 839   std::set<unsigned int> hashes;
 840   mutable pthread_rwlock_t d_lock;
 841   std::vector<int> sockets;
 842   std::mutex socketsLock;
 843   std::mutex connectLock;
 844   std::unique_ptr<FDMultiplexer> mplexer{nullptr};
 845   std::thread tid;
 846   const ComboAddress remote;
 847   QPSLimiter qps;
 848   vector<IDState> idStates;
 849   const ComboAddress sourceAddr;
 850   checkfunc_t checkFunction;
 851   DNSName checkName{"a.root-servers.net."};
 852   QType checkType{QType::A};
 853   uint16_t checkClass{QClass::IN};
 854   std::atomic<uint64_t> idOffset{0};
 855   std::atomic<uint64_t> sendErrors{0};
 856   std::atomic<uint64_t> outstanding{0};
 857   std::atomic<uint64_t> reuseds{0};
 858   std::atomic<uint64_t> queries{0};
 859   std::atomic<uint64_t> responses{0};
 860   struct {
 861     std::atomic<uint64_t> sendErrors{0};
 862     std::atomic<uint64_t> reuseds{0};
 863     std::atomic<uint64_t> queries{0};
 864   } prev;
 865   std::atomic<uint64_t> tcpDiedSendingQuery{0};
 866   std::atomic<uint64_t> tcpDiedReadingResponse{0};
 867   std::atomic<uint64_t> tcpGaveUp{0};
 868   std::atomic<uint64_t> tcpReadTimeouts{0};
 869   std::atomic<uint64_t> tcpWriteTimeouts{0};
 870   std::atomic<uint64_t> tcpCurrentConnections{0};
 871   std::atomic<double> tcpAvgQueriesPerConnection{0.0};
 872   /* in ms */
 873   std::atomic<double> tcpAvgConnectionDuration{0.0};
 874   string name;
 875   size_t socketsOffset{0};
 876   double queryLoad{0.0};
 877   double dropRate{0.0};
 878   double latencyUsec{0.0};
 879   int order{1};
 880   int weight{1};
 881   int tcpConnectTimeout{5};
 882   int tcpRecvTimeout{30};
 883   int tcpSendTimeout{30};
 884   unsigned int checkInterval{1};
 885   unsigned int lastCheck{0};
 886   const unsigned int sourceItf{0};
 887   uint16_t retries{5};
 888   uint16_t xpfRRCode{0};
 889   uint16_t checkTimeout{1000}; /* in milliseconds */
 890   uint8_t currentCheckFailures{0};
 891   uint8_t consecutiveSuccessfulChecks{0};
 892   uint8_t maxCheckFailures{1};
 893   uint8_t minRiseSuccesses{1};
 894   StopWatch sw;
 895   set<string> pools;
 896   enum class Availability { Up, Down, Auto} availability{Availability::Auto};
 897   bool mustResolve{false};
 898   bool upStatus{false};
 899   bool useECS{false};
 900   bool setCD{false};
 901   bool disableZeroScope{false};
 902   std::atomic<bool> connected{false};
 903   std::atomic_flag threadStarted;
 904   bool tcpFastOpen{false};
 905   bool ipBindAddrNoPort{true};
 906
 907   bool isUp() const
 908   {
 909     if(availability == Availability::Down)
 910       return false;
 911     if(availability == Availability::Up)
 912       return true;
 913     return upStatus;
 914   }
 915   void setUp() { availability = Availability::Up; }
 916   void setDown() { availability = Availability::Down; }
 917   void setAuto() { availability = Availability::Auto; }
 918   string getName() const {
 919     if (name.empty()) {
 920       return remote.toStringWithPort();
 921     }
 922     return name;
 923   }
 924   string getNameWithAddr() const {
 925     if (name.empty()) {
 926       return remote.toStringWithPort();
 927     }
 928     return name + " (" + remote.toStringWithPort()+ ")";
 929   }
 930   string getStatus() const
 931   {
 932     string status;
 933     if(availability == DownstreamState::Availability::Up)
 934       status = "UP";
 935     else if(availability == DownstreamState::Availability::Down)
 936       status = "DOWN";
 937     else
 938       status = (upStatus ? "up" : "down");
 939     return status;
 940   }
 941   bool reconnect();
 942   void hash();
 943   void setId(const boost::uuids::uuid& newId);
 944   void setWeight(int newWeight);
 945
 946   void updateTCPMetrics(size_t queries, uint64_t durationMs)
 947   {
 948     tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (queries / 100.0);
 949     tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
 950   }
 951 };
 952 using servers_t =vector<std::shared_ptr<DownstreamState>>;
 953
 954 template <class T> using NumberedVector = std::vector<std::pair<unsigned int, T> >;
 955
 956 void responderThread(std::shared_ptr<DownstreamState> state);
 957 extern std::mutex g_luamutex;
 958 extern LuaContext g_lua;
 959 extern std::string g_outputBuffer; // locking for this is ok, as locked by g_luamutex
 960
 961 class DNSRule
 962 {
 963 public:
 964   virtual ~DNSRule ()
 965   {
 966   }
 967   virtual bool matches(const DNSQuestion* dq) const =0;
 968   virtual string toString() const = 0;
 969   mutable std::atomic<uint64_t> d_matches{0};
 970 };
 971
 972 using NumberedServerVector = NumberedVector<shared_ptr<DownstreamState>>;
 973 typedef std::function<shared_ptr<DownstreamState>(const NumberedServerVector& servers, const DNSQuestion*)> policyfunc_t;
 974
 975 struct ServerPolicy
 976 {
 977   string name;
 978   policyfunc_t policy;
 979   bool isLua;
 980   std::string toString() const {
 981     return string("ServerPolicy") + (isLua ? " (Lua)" : "") + " \"" + name + "\"";
 982   }
 983 };
 984
 985 struct ServerPool
 986 {
 987   ServerPool()
 988   {
 989     pthread_rwlock_init(&d_lock, nullptr);
 990   }
 991
 992   const std::shared_ptr<DNSDistPacketCache> getCache() const { return packetCache; };
 993
 994   bool getECS() const
 995   {
 996     return d_useECS;
 997   }
 998
 999   void setECS(bool useECS)
1000   {
1001     d_useECS = useECS;
1002   }
1003
1004   std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
1005   std::shared_ptr<ServerPolicy> policy{nullptr};
1006
1007   size_t countServers(bool upOnly)
1008   {
1009     size_t count = 0;
1010     ReadLock rl(&d_lock);
1011     for (const auto& server : d_servers) {
1012       if (!upOnly || std::get<1>(server)->isUp() ) {
1013         count++;
1014       }
1015     }
1016     return count;
1017   }
1018
1019   NumberedVector<shared_ptr<DownstreamState>> getServers()
1020   {
1021     NumberedVector<shared_ptr<DownstreamState>> result;
1022     {
1023       ReadLock rl(&d_lock);
1024       result = d_servers;
1025     }
1026     return result;
1027   }
1028
1029   void addServer(shared_ptr<DownstreamState>& server)
1030   {
1031     WriteLock wl(&d_lock);
1032     unsigned int count = (unsigned int) d_servers.size();
1033     d_servers.push_back(make_pair(++count, server));
1034     /* we need to reorder based on the server 'order' */
1035     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) {
1036       return a.second->order < b.second->order;
1037     });
1038     /* and now we need to renumber for Lua (custom policies) */
1039     size_t idx = 1;
1040     for (auto& serv : d_servers) {
1041       serv.first = idx++;
1042     }
1043   }
1044
1045   void removeServer(shared_ptr<DownstreamState>& server)
1046   {
1047     WriteLock wl(&d_lock);
1048     size_t idx = 1;
1049     bool found = false;
1050     for (auto it = d_servers.begin(); it != d_servers.end();) {
1051       if (found) {
1052         /* we need to renumber the servers placed
1053            after the removed one, for Lua (custom policies) */
1054         it->first = idx++;
1055         it++;
1056       }
1057       else if (it->second == server) {
1058         it = d_servers.erase(it);
1059         found = true;
1060       } else {
1061         idx++;
1062         it++;
1063       }
1064     }
1065   }
1066
1067 private:
1068   NumberedVector<shared_ptr<DownstreamState>> d_servers;
1069   pthread_rwlock_t d_lock;
1070   bool d_useECS{false};
1071 };
1072 using pools_t=map<std::string,std::shared_ptr<ServerPool>>;
1073 void setPoolPolicy(pools_t& pools, const string& poolName, std::shared_ptr<ServerPolicy> policy);
1074 void addServerToPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
1075 void removeServerFromPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
1076
1077 struct CarbonConfig
1078 {
1079   ComboAddress server;
1080   std::string namespace_name;
1081   std::string ourname;
1082   std::string instance_name;
1083   unsigned int interval;
1084 };
1085
1086 enum ednsHeaderFlags {
1087   EDNS_HEADER_FLAG_NONE = 0,
1088   EDNS_HEADER_FLAG_DO = 32768
1089 };
1090
1091 struct DNSDistRuleAction
1092 {
1093   std::shared_ptr<DNSRule> d_rule;
1094   std::shared_ptr<DNSAction> d_action;
1095   boost::uuids::uuid d_id;
1096   uint64_t d_creationOrder;
1097 };
1098
1099 struct DNSDistResponseRuleAction
1100 {
1101   std::shared_ptr<DNSRule> d_rule;
1102   std::shared_ptr<DNSResponseAction> d_action;
1103   boost::uuids::uuid d_id;
1104   uint64_t d_creationOrder;
1105 };
1106
1107 extern GlobalStateHolder<SuffixMatchTree<DynBlock>> g_dynblockSMT;
1108 extern DNSAction::Action g_dynBlockAction;
1109
1110 extern GlobalStateHolder<vector<CarbonConfig> > g_carbon;
1111 extern GlobalStateHolder<ServerPolicy> g_policy;
1112 extern GlobalStateHolder<servers_t> g_dstates;
1113 extern GlobalStateHolder<pools_t> g_pools;
1114 extern GlobalStateHolder<vector<DNSDistRuleAction> > g_rulactions;
1115 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_resprulactions;
1116 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_cachehitresprulactions;
1117 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_selfansweredresprulactions;
1118 extern GlobalStateHolder<NetmaskGroup> g_ACL;
1119
1120 extern ComboAddress g_serverControl; // not changed during runtime
1121
1122 extern std::vector<std::tuple<ComboAddress, bool, bool, int, std::string, std::set<int>>> g_locals; // not changed at runtime (we hope XXX)
1123 extern std::vector<shared_ptr<TLSFrontend>> g_tlslocals;
1124 extern std::vector<shared_ptr<DOHFrontend>> g_dohlocals;
1125 extern std::vector<std::unique_ptr<ClientState>> g_frontends;
1126 extern bool g_truncateTC;
1127 extern bool g_fixupCase;
1128 extern int g_tcpRecvTimeout;
1129 extern int g_tcpSendTimeout;
1130 extern int g_udpTimeout;
1131 extern uint16_t g_maxOutstanding;
1132 extern std::atomic<bool> g_configurationDone;
1133 extern uint64_t g_maxTCPClientThreads;
1134 extern uint64_t g_maxTCPQueuedConnections;
1135 extern size_t g_maxTCPQueriesPerConn;
1136 extern size_t g_maxTCPConnectionDuration;
1137 extern size_t g_maxTCPConnectionsPerClient;
1138 extern std::atomic<uint16_t> g_cacheCleaningDelay;
1139 extern std::atomic<uint16_t> g_cacheCleaningPercentage;
1140 extern bool g_verboseHealthChecks;
1141 extern uint32_t g_staleCacheEntriesTTL;
1142 extern bool g_apiReadWrite;
1143 extern std::string g_apiConfigDirectory;
1144 extern bool g_servFailOnNoPolicy;
1145 extern uint32_t g_hashperturb;
1146 extern bool g_useTCPSinglePipe;
1147 extern uint16_t g_downstreamTCPCleanupInterval;
1148 extern size_t g_udpVectorSize;
1149 extern bool g_preserveTrailingData;
1150 extern bool g_allowEmptyResponse;
1151 extern bool g_roundrobinFailOnNoServer;
1152
1153 #ifdef HAVE_EBPF
1154 extern shared_ptr<BPFFilter> g_defaultBPFFilter;
1155 extern std::vector<std::shared_ptr<DynBPFFilter> > g_dynBPFFilters;
1156 #endif /* HAVE_EBPF */
1157
1158 struct LocalHolders
1159 {
1160   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())
1161   {
1162   }
1163
1164   LocalStateHolder<NetmaskGroup> acl;
1165   LocalStateHolder<ServerPolicy> policy;
1166   LocalStateHolder<vector<DNSDistRuleAction> > rulactions;
1167   LocalStateHolder<vector<DNSDistResponseRuleAction> > cacheHitRespRulactions;
1168   LocalStateHolder<vector<DNSDistResponseRuleAction> > selfAnsweredRespRulactions;
1169   LocalStateHolder<servers_t> servers;
1170   LocalStateHolder<NetmaskTree<DynBlock> > dynNMGBlock;
1171   LocalStateHolder<SuffixMatchTree<DynBlock> > dynSMTBlock;
1172   LocalStateHolder<pools_t> pools;
1173 };
1174
1175 struct dnsheader;
1176
1177 void controlThread(int fd, ComboAddress local);
1178 vector<std::function<void(void)>> setupLua(bool client, const std::string& config);
1179 std::shared_ptr<ServerPool> getPool(const pools_t& pools, const std::string& poolName);
1180 std::shared_ptr<ServerPool> createPoolIfNotExists(pools_t& pools, const string& poolName);
1181 NumberedServerVector getDownstreamCandidates(const pools_t& pools, const std::string& poolName);
1182
1183 std::shared_ptr<DownstreamState> firstAvailable(const NumberedServerVector& servers, const DNSQuestion* dq);
1184
1185 std::shared_ptr<DownstreamState> leastOutstanding(const NumberedServerVector& servers, const DNSQuestion* dq);
1186 std::shared_ptr<DownstreamState> wrandom(const NumberedServerVector& servers, const DNSQuestion* dq);
1187 std::shared_ptr<DownstreamState> whashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1188 std::shared_ptr<DownstreamState> chashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1189 std::shared_ptr<DownstreamState> roundrobin(const NumberedServerVector& servers, const DNSQuestion* dq);
1190
1191 struct WebserverConfig
1192 {
1193   std::string password;
1194   std::string apiKey;
1195   boost::optional<std::map<std::string, std::string> > customHeaders;
1196   std::mutex lock;
1197 };
1198
1199 void setWebserverAPIKey(const boost::optional<std::string> apiKey);
1200 void setWebserverPassword(const std::string& password);
1201 void setWebserverCustomHeaders(const boost::optional<std::map<std::string, std::string> > customHeaders);
1202
1203 void dnsdistWebserverThread(int sock, const ComboAddress& local);
1204 void tcpAcceptorThread(void* p);
1205 #ifdef HAVE_DNS_OVER_HTTPS
1206 void dohThread(ClientState* cs);
1207 #endif /* HAVE_DNS_OVER_HTTPS */
1208
1209 void setLuaNoSideEffect(); // if nothing has been declared, set that there are no side effects
1210 void setLuaSideEffect();   // set to report a side effect, cancelling all _no_ side effect calls
1211 bool getLuaNoSideEffect(); // set if there were only explicit declarations of _no_ side effect
1212 void resetLuaSideEffect(); // reset to indeterminate state
1213
1214 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);
1215 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);
1216 bool processRulesResult(const DNSAction::Action& action, DNSQuestion& dq, std::string& ruleresult, bool& drop);
1217
1218 bool checkQueryHeaders(const struct dnsheader* dh);
1219
1220 extern std::vector<std::shared_ptr<DNSCryptContext>> g_dnsCryptLocals;
1221 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);
1222 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);
1223
1224 bool addXPF(DNSQuestion& dq, uint16_t optionCode);
1225
1226 uint16_t getRandomDNSID();
1227
1228 #include "dnsdist-snmp.hh"
1229
1230 extern bool g_snmpEnabled;
1231 extern bool g_snmpTrapsEnabled;
1232 extern DNSDistSNMPAgent* g_snmpAgent;
1233 extern bool g_addEDNSToSelfGeneratedResponses;
1234
1235 static const size_t s_udpIncomingBufferSize{1500};
1236
1237 enum class ProcessQueryResult { Drop, SendAnswer, PassToBackend };
1238 ProcessQueryResult processQuery(DNSQuestion& dq, ClientState& cs, LocalHolders& holders, std::shared_ptr<DownstreamState>& selectedBackend);
1239
1240 DNSResponse makeDNSResponseFromIDState(IDState& ids, struct dnsheader* dh, size_t bufferSize, uint16_t responseLen, bool isTCP);
1241 void setIDStateFromDNSQuestion(IDState& ids, DNSQuestion& dq, DNSName&& qname);
1242
1243 int pickBackendSocketForSending(std::shared_ptr<DownstreamState>& state);
1244 ssize_t udpClientSendRequestToBackend(const std::shared_ptr<DownstreamState>& ss, const int sd, const char* request, const size_t requestLen, bool healthCheck=false);