2 * This file is part of PowerDNS or dnsdist.
3 * Copyright -- PowerDNS.COM B.V. and its contributors
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.
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.
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.
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.
24 #include "ext/luawrapper/include/LuaContext.hpp"
32 #include <unordered_map>
34 #include <boost/variant.hpp>
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"
44 #include "ednsoptions.hh"
50 #include "tcpiohandler.hh"
51 #include "uuid-utils.hh"
53 void carbonDumpThread();
54 uint64_t uptimeOfProcess(const std::string& str);
56 extern uint16_t g_ECSSourcePrefixV4;
57 extern uint16_t g_ECSSourcePrefixV6;
58 extern bool g_ECSOverride;
60 typedef std::unordered_map<string, string> QTag;
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);
69 DNSQuestion(const DNSQuestion&) = delete;
70 DNSQuestion& operator=(const DNSQuestion&) = delete;
71 DNSQuestion(DNSQuestion&&) = default;
74 boost::optional<boost::uuids::uuid> uniqueId;
77 boost::optional<Netmask> subnet;
78 std::string sni; /* Server Name Indication, if any (DoT or DoH) */
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};
91 unsigned int consumed{0};
93 boost::optional<uint32_t> tempFailureTTL;
94 uint32_t cacheKeyNoECS;
97 const uint16_t qclass;
99 uint16_t ecsPrefixLength;
101 uint8_t ednsRCode{0};
103 bool skipCache{false};
108 bool ecsAdded{false};
109 bool ednsAdded{false};
110 bool useZeroScope{false};
111 bool dnssecOK{false};
114 struct DNSResponse : DNSQuestion
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;
123 /* so what could you do:
126 provide actual answer,
127 allow & and stop processing,
129 modify header: (servfail|refused|notimp), set TC=1,
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)
141 case Action::Nxdomain:
142 return "Send NXDomain";
143 case Action::Refused:
144 return "Send Refused";
146 return "Spoof an answer";
149 case Action::HeaderModify:
150 return "Modify the header";
152 return "Route to a pool";
155 case Action::Truncate:
156 return "Truncate over UDP";
157 case Action::ServFail:
158 return "Send ServFail";
162 case Action::NoRecurse:
169 virtual Action operator()(DNSQuestion*, string* ruleresult) const =0;
173 virtual string toString() const = 0;
174 virtual std::map<string, double> getStats() const
180 class DNSResponseAction
183 enum class Action { Allow, Delay, Drop, HeaderModify, ServFail, None };
184 virtual Action operator()(DNSResponse*, string* ruleresult) const =0;
185 virtual ~DNSResponseAction()
188 virtual string toString() const = 0;
193 DynBlock(): action(DNSAction::Action::None), warning(false)
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)
201 DynBlock(const DynBlock& rhs): reason(rhs.reason), until(rhs.until), domain(rhs.domain), action(rhs.action), warning(rhs.warning)
203 blocks.store(rhs.blocks);
206 DynBlock& operator=(const DynBlock& rhs)
212 blocks.store(rhs.blocks);
218 struct timespec until;
220 DNSAction::Action action;
221 mutable std::atomic<unsigned int> blocks;
225 extern GlobalStateHolder<NetmaskTree<DynBlock>> g_dynblockNMG;
227 extern vector<pair<struct timeval, std::string> > g_confDelta;
229 extern uint64_t getLatencyCount(const std::string&);
233 using stat_t=std::atomic<uint64_t>; // aww yiss ;-)
235 stat_t servfailResponses{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};
243 stat_t emptyQueries{0};
245 stat_t dynBlocked{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};
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};
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},
306 {"latency-sum", &latencySum},
307 {"latency-count", getLatencyCount},
311 // Metric types for Prometheus
312 enum class PrometheusMetricType: int {
317 // Keeps additional information about metrics
318 struct MetricDefinition {
319 MetricDefinition(PrometheusMetricType _prometheusType, const std::string& _description): description(_description), prometheusType(_prometheusType) {
322 MetricDefinition() = default;
324 // Metric description
325 std::string description;
326 // Metric type for Prometheus
327 PrometheusMetricType prometheusType;
330 struct MetricDefinitionStorage {
331 // Return metric definition by name
332 bool getMetricDetails(std::string metricName, MetricDefinition& metric) {
333 auto metricDetailsIter = metrics.find(metricName);
335 if (metricDetailsIter == metrics.end()) {
339 metric = metricDetailsIter->second;
343 // Return string representation of Prometheus metric type
344 std::string getPrometheusStringMetricType(PrometheusMetricType metricType) {
345 switch (metricType) {
346 case PrometheusMetricType::counter:
349 case PrometheusMetricType::gauge:
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") },
402 extern MetricDefinitionStorage g_metricDefinitions;
403 extern struct DNSDistStats g_stats;
404 void doLatencyStats(double udiff);
409 StopWatch(bool realTime=false): d_needRealTime(realTime)
412 struct timespec d_start{0,0};
413 bool d_needRealTime{false};
416 if(gettime(&d_start, d_needRealTime) < 0)
417 unixDie("Getting timestamp");
421 void set(const struct timespec& from) {
425 double udiff() const {
427 if(gettime(&now, d_needRealTime) < 0)
428 unixDie("Getting timestamp");
430 return 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
433 double udiffAndSet() {
435 if(gettime(&now, d_needRealTime) < 0)
436 unixDie("Getting timestamp");
438 auto ret= 1000000.0*(now.tv_sec - d_start.tv_sec) + (now.tv_nsec - d_start.tv_nsec)/1000.0;
445 class BasicQPSLimiter
452 BasicQPSLimiter(unsigned int burst): d_tokens(burst)
457 bool check(unsigned int rate, unsigned int burst) const // this is not quite fair
459 auto delta = d_prev.udiffAndSet();
461 if(delta > 0.0) // time, frequently, does go backwards..
462 d_tokens += 1.0 * rate * (delta/1000000.0);
464 if(d_tokens > burst) {
469 if(d_tokens >= 1.0) { // we need this because burst=1 is weird otherwise
477 bool seenSince(const struct timespec& cutOff) const
479 return cutOff < d_prev.d_start;
483 mutable StopWatch d_prev;
484 mutable double d_tokens;
487 class QPSLimiter : public BasicQPSLimiter
490 QPSLimiter(): BasicQPSLimiter()
494 QPSLimiter(unsigned int rate, unsigned int burst): BasicQPSLimiter(burst), d_rate(rate), d_burst(burst), d_passthrough(false)
499 unsigned int getRate() const
501 return d_passthrough ? 0 : d_rate;
504 int getPassed() const
509 int getBlocked() const
514 bool check() const // this is not quite fair
520 bool ret = BasicQPSLimiter::check(d_rate, d_burst);
531 mutable unsigned int d_passed{0};
532 mutable unsigned int d_blocked{0};
534 unsigned int d_burst;
535 bool d_passthrough{true};
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)
545 usageIndicator.store(orig.usageIndicator.load());
546 origFD = orig.origFD;
547 origID = orig.origID;
548 delayMsec = orig.delayMsec;
549 tempFailureTTL = orig.tempFailureTTL;
552 static const int64_t unusedIndicator = -1;
554 static bool isInUse(int64_t usageIndicator)
556 return usageIndicator != unusedIndicator;
561 return usageIndicator != unusedIndicator;
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)
568 return usageIndicator.compare_exchange_strong(expectedUsageIndicator, unusedIndicator);
571 /* mark as unused no matter what, return true if the state was in use before */
574 auto currentGeneration = generation++;
575 return markAsUsed(currentGeneration);
578 /* mark as unused no matter what, return true if the state was in use before */
579 bool markAsUsed(int64_t currentGeneration)
581 int64_t oldUsage = usageIndicator.exchange(currentGeneration);
582 return oldUsage != unusedIndicator;
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
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.
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
624 std::shared_ptr<DNSCryptQuery> dnsCryptQuery{nullptr};
626 boost::optional<boost::uuids::uuid> uniqueId;
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
637 uint16_t qclass; // 2
638 uint16_t origID; // 2
639 uint16_t origFlags; // 2
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};
651 typedef std::unordered_map<string, unsigned int> QueryCountRecords;
652 typedef std::function<std::tuple<bool, string>(const DNSQuestion* dq)> QueryCountFilter;
656 pthread_rwlock_init(&queryLock, nullptr);
658 QueryCountRecords records;
659 QueryCountFilter filter;
660 pthread_rwlock_t queryLock;
664 extern QueryCount g_qcount;
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)
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 std::atomic<uint64_t> tls10queries{0}; // valid DNS queries received via TLSv1.0
689 std::atomic<uint64_t> tls11queries{0}; // valid DNS queries received via TLSv1.1
690 std::atomic<uint64_t> tls12queries{0}; // valid DNS queries received via TLSv1.2
691 std::atomic<uint64_t> tls13queries{0}; // valid DNS queries received via TLSv1.3
692 std::atomic<uint64_t> tlsUnknownqueries{0}; // valid DNS queries received via unknown TLS version
694 std::atomic<double> tcpAvgQueriesPerConnection{0.0};
696 std::atomic<double> tcpAvgConnectionDuration{0.0};
699 int fastOpenQueueSize{0};
705 int getSocket() const
707 return udpFD != -1 ? udpFD : tcpFD;
720 std::string getType() const
722 std::string result = udpFD != -1 ? "UDP" : "TCP";
725 result += " (DNS over HTTPS)";
727 else if (tlsFrontend) {
728 result += " (DNS over TLS)";
730 else if (dnscryptCtx) {
731 result += " (DNSCrypt)";
738 shared_ptr<BPFFilter> d_filter;
743 d_filter->removeSocket(getSocket());
748 void attachFilter(shared_ptr<BPFFilter> bpf)
752 bpf->addSocket(getSocket());
755 #endif /* HAVE_EBPF */
757 void updateTCPMetrics(size_t nbQueries, uint64_t durationMs)
759 tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (nbQueries / 100.0);
760 tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
764 class TCPClientCollection {
765 std::vector<int> d_tcpclientthreads;
766 std::atomic<uint64_t> d_numthreads{0};
767 std::atomic<uint64_t> d_pos{0};
768 std::atomic<uint64_t> d_queued{0};
769 const uint64_t d_maxthreads{0};
772 const bool d_useSinglePipe;
775 TCPClientCollection(size_t maxThreads, bool useSinglePipe=false): d_maxthreads(maxThreads), d_singlePipe{-1,-1}, d_useSinglePipe(useSinglePipe)
778 d_tcpclientthreads.reserve(maxThreads);
780 if (d_useSinglePipe) {
781 if (pipe(d_singlePipe) < 0) {
783 throw std::runtime_error("Error creating the TCP single communication pipe: " + stringerror(err));
786 if (!setNonBlocking(d_singlePipe[0])) {
788 close(d_singlePipe[0]);
789 close(d_singlePipe[1]);
790 throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + stringerror(err));
793 if (!setNonBlocking(d_singlePipe[1])) {
795 close(d_singlePipe[0]);
796 close(d_singlePipe[1]);
797 throw std::runtime_error("Error setting the TCP single communication pipe non-blocking: " + stringerror(err));
803 uint64_t pos = d_pos++;
805 return d_tcpclientthreads[pos % d_numthreads];
807 bool hasReachedMaxThreads() const
809 return d_numthreads >= d_maxthreads;
811 uint64_t getThreadsCount() const
815 uint64_t getQueuedCount() const
819 void decrementQueuedCount()
823 void addTCPClientThread();
826 extern std::unique_ptr<TCPClientCollection> g_tcpclientthreads;
828 struct DownstreamState
830 typedef std::function<std::tuple<DNSName, uint16_t, uint16_t>(const DNSName&, uint16_t, uint16_t, dnsheader*)> checkfunc_t;
832 DownstreamState(const ComboAddress& remote_, const ComboAddress& sourceAddr_, unsigned int sourceItf, size_t numberOfSockets);
833 DownstreamState(const ComboAddress& remote_): DownstreamState(remote_, ComboAddress(), 0, 1) {}
836 for (auto& fd : sockets) {
843 boost::uuids::uuid id;
844 std::set<unsigned int> hashes;
845 mutable pthread_rwlock_t d_lock;
846 std::vector<int> sockets;
847 std::mutex socketsLock;
848 std::mutex connectLock;
849 std::unique_ptr<FDMultiplexer> mplexer{nullptr};
851 const ComboAddress remote;
853 vector<IDState> idStates;
854 const ComboAddress sourceAddr;
855 checkfunc_t checkFunction;
856 DNSName checkName{"a.root-servers.net."};
857 QType checkType{QType::A};
858 uint16_t checkClass{QClass::IN};
859 std::atomic<uint64_t> idOffset{0};
860 std::atomic<uint64_t> sendErrors{0};
861 std::atomic<uint64_t> outstanding{0};
862 std::atomic<uint64_t> reuseds{0};
863 std::atomic<uint64_t> queries{0};
864 std::atomic<uint64_t> responses{0};
866 std::atomic<uint64_t> sendErrors{0};
867 std::atomic<uint64_t> reuseds{0};
868 std::atomic<uint64_t> queries{0};
870 std::atomic<uint64_t> tcpDiedSendingQuery{0};
871 std::atomic<uint64_t> tcpDiedReadingResponse{0};
872 std::atomic<uint64_t> tcpGaveUp{0};
873 std::atomic<uint64_t> tcpReadTimeouts{0};
874 std::atomic<uint64_t> tcpWriteTimeouts{0};
875 std::atomic<uint64_t> tcpCurrentConnections{0};
876 std::atomic<double> tcpAvgQueriesPerConnection{0.0};
878 std::atomic<double> tcpAvgConnectionDuration{0.0};
880 size_t socketsOffset{0};
881 double queryLoad{0.0};
882 double dropRate{0.0};
883 double latencyUsec{0.0};
886 int tcpConnectTimeout{5};
887 int tcpRecvTimeout{30};
888 int tcpSendTimeout{30};
889 unsigned int checkInterval{1};
890 unsigned int lastCheck{0};
891 const unsigned int sourceItf{0};
893 uint16_t xpfRRCode{0};
894 uint16_t checkTimeout{1000}; /* in milliseconds */
895 uint8_t currentCheckFailures{0};
896 uint8_t consecutiveSuccessfulChecks{0};
897 uint8_t maxCheckFailures{1};
898 uint8_t minRiseSuccesses{1};
901 enum class Availability { Up, Down, Auto} availability{Availability::Auto};
902 bool mustResolve{false};
903 bool upStatus{false};
906 bool disableZeroScope{false};
907 std::atomic<bool> connected{false};
908 std::atomic_flag threadStarted;
909 bool tcpFastOpen{false};
910 bool ipBindAddrNoPort{true};
914 if(availability == Availability::Down)
916 if(availability == Availability::Up)
920 void setUp() { availability = Availability::Up; }
921 void setDown() { availability = Availability::Down; }
922 void setAuto() { availability = Availability::Auto; }
923 string getName() const {
925 return remote.toStringWithPort();
929 string getNameWithAddr() const {
931 return remote.toStringWithPort();
933 return name + " (" + remote.toStringWithPort()+ ")";
935 string getStatus() const
938 if(availability == DownstreamState::Availability::Up)
940 else if(availability == DownstreamState::Availability::Down)
943 status = (upStatus ? "up" : "down");
948 void setId(const boost::uuids::uuid& newId);
949 void setWeight(int newWeight);
951 void updateTCPMetrics(size_t nbQueries, uint64_t durationMs)
953 tcpAvgQueriesPerConnection = (99.0 * tcpAvgQueriesPerConnection / 100.0) + (nbQueries / 100.0);
954 tcpAvgConnectionDuration = (99.0 * tcpAvgConnectionDuration / 100.0) + (durationMs / 100.0);
957 using servers_t =vector<std::shared_ptr<DownstreamState>>;
959 template <class T> using NumberedVector = std::vector<std::pair<unsigned int, T> >;
961 void responderThread(std::shared_ptr<DownstreamState> state);
962 extern std::mutex g_luamutex;
963 extern LuaContext g_lua;
964 extern std::string g_outputBuffer; // locking for this is ok, as locked by g_luamutex
972 virtual bool matches(const DNSQuestion* dq) const =0;
973 virtual string toString() const = 0;
974 mutable std::atomic<uint64_t> d_matches{0};
977 using NumberedServerVector = NumberedVector<shared_ptr<DownstreamState>>;
978 typedef std::function<shared_ptr<DownstreamState>(const NumberedServerVector& servers, const DNSQuestion*)> policyfunc_t;
985 std::string toString() const {
986 return string("ServerPolicy") + (isLua ? " (Lua)" : "") + " \"" + name + "\"";
994 pthread_rwlock_init(&d_lock, nullptr);
997 const std::shared_ptr<DNSDistPacketCache> getCache() const { return packetCache; };
1004 void setECS(bool useECS)
1009 std::shared_ptr<DNSDistPacketCache> packetCache{nullptr};
1010 std::shared_ptr<ServerPolicy> policy{nullptr};
1012 size_t countServers(bool upOnly)
1015 ReadLock rl(&d_lock);
1016 for (const auto& server : d_servers) {
1017 if (!upOnly || std::get<1>(server)->isUp() ) {
1024 NumberedVector<shared_ptr<DownstreamState>> getServers()
1026 NumberedVector<shared_ptr<DownstreamState>> result;
1028 ReadLock rl(&d_lock);
1034 void addServer(shared_ptr<DownstreamState>& server)
1036 WriteLock wl(&d_lock);
1037 unsigned int count = (unsigned int) d_servers.size();
1038 d_servers.push_back(make_pair(++count, server));
1039 /* we need to reorder based on the server 'order' */
1040 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) {
1041 return a.second->order < b.second->order;
1043 /* and now we need to renumber for Lua (custom policies) */
1045 for (auto& serv : d_servers) {
1050 void removeServer(shared_ptr<DownstreamState>& server)
1052 WriteLock wl(&d_lock);
1055 for (auto it = d_servers.begin(); it != d_servers.end();) {
1057 /* we need to renumber the servers placed
1058 after the removed one, for Lua (custom policies) */
1062 else if (it->second == server) {
1063 it = d_servers.erase(it);
1073 NumberedVector<shared_ptr<DownstreamState>> d_servers;
1074 pthread_rwlock_t d_lock;
1075 bool d_useECS{false};
1077 using pools_t=map<std::string,std::shared_ptr<ServerPool>>;
1078 void setPoolPolicy(pools_t& pools, const string& poolName, std::shared_ptr<ServerPolicy> policy);
1079 void addServerToPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
1080 void removeServerFromPool(pools_t& pools, const string& poolName, std::shared_ptr<DownstreamState> server);
1084 ComboAddress server;
1085 std::string namespace_name;
1086 std::string ourname;
1087 std::string instance_name;
1088 unsigned int interval;
1091 enum ednsHeaderFlags {
1092 EDNS_HEADER_FLAG_NONE = 0,
1093 EDNS_HEADER_FLAG_DO = 32768
1096 struct DNSDistRuleAction
1098 std::shared_ptr<DNSRule> d_rule;
1099 std::shared_ptr<DNSAction> d_action;
1100 boost::uuids::uuid d_id;
1101 uint64_t d_creationOrder;
1104 struct DNSDistResponseRuleAction
1106 std::shared_ptr<DNSRule> d_rule;
1107 std::shared_ptr<DNSResponseAction> d_action;
1108 boost::uuids::uuid d_id;
1109 uint64_t d_creationOrder;
1112 extern GlobalStateHolder<SuffixMatchTree<DynBlock>> g_dynblockSMT;
1113 extern DNSAction::Action g_dynBlockAction;
1115 extern GlobalStateHolder<vector<CarbonConfig> > g_carbon;
1116 extern GlobalStateHolder<ServerPolicy> g_policy;
1117 extern GlobalStateHolder<servers_t> g_dstates;
1118 extern GlobalStateHolder<pools_t> g_pools;
1119 extern GlobalStateHolder<vector<DNSDistRuleAction> > g_rulactions;
1120 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_resprulactions;
1121 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_cachehitresprulactions;
1122 extern GlobalStateHolder<vector<DNSDistResponseRuleAction> > g_selfansweredresprulactions;
1123 extern GlobalStateHolder<NetmaskGroup> g_ACL;
1125 extern ComboAddress g_serverControl; // not changed during runtime
1127 extern std::vector<std::tuple<ComboAddress, bool, bool, int, std::string, std::set<int>>> g_locals; // not changed at runtime (we hope XXX)
1128 extern std::vector<shared_ptr<TLSFrontend>> g_tlslocals;
1129 extern std::vector<shared_ptr<DOHFrontend>> g_dohlocals;
1130 extern std::vector<std::unique_ptr<ClientState>> g_frontends;
1131 extern bool g_truncateTC;
1132 extern bool g_fixupCase;
1133 extern int g_tcpRecvTimeout;
1134 extern int g_tcpSendTimeout;
1135 extern int g_udpTimeout;
1136 extern uint16_t g_maxOutstanding;
1137 extern std::atomic<bool> g_configurationDone;
1138 extern uint64_t g_maxTCPClientThreads;
1139 extern uint64_t g_maxTCPQueuedConnections;
1140 extern size_t g_maxTCPQueriesPerConn;
1141 extern size_t g_maxTCPConnectionDuration;
1142 extern size_t g_maxTCPConnectionsPerClient;
1143 extern std::atomic<uint16_t> g_cacheCleaningDelay;
1144 extern std::atomic<uint16_t> g_cacheCleaningPercentage;
1145 extern bool g_verboseHealthChecks;
1146 extern uint32_t g_staleCacheEntriesTTL;
1147 extern bool g_apiReadWrite;
1148 extern std::string g_apiConfigDirectory;
1149 extern bool g_servFailOnNoPolicy;
1150 extern uint32_t g_hashperturb;
1151 extern bool g_useTCPSinglePipe;
1152 extern uint16_t g_downstreamTCPCleanupInterval;
1153 extern size_t g_udpVectorSize;
1154 extern bool g_preserveTrailingData;
1155 extern bool g_allowEmptyResponse;
1156 extern bool g_roundrobinFailOnNoServer;
1159 extern shared_ptr<BPFFilter> g_defaultBPFFilter;
1160 extern std::vector<std::shared_ptr<DynBPFFilter> > g_dynBPFFilters;
1161 #endif /* HAVE_EBPF */
1165 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())
1169 LocalStateHolder<NetmaskGroup> acl;
1170 LocalStateHolder<ServerPolicy> policy;
1171 LocalStateHolder<vector<DNSDistRuleAction> > rulactions;
1172 LocalStateHolder<vector<DNSDistResponseRuleAction> > cacheHitRespRulactions;
1173 LocalStateHolder<vector<DNSDistResponseRuleAction> > selfAnsweredRespRulactions;
1174 LocalStateHolder<servers_t> servers;
1175 LocalStateHolder<NetmaskTree<DynBlock> > dynNMGBlock;
1176 LocalStateHolder<SuffixMatchTree<DynBlock> > dynSMTBlock;
1177 LocalStateHolder<pools_t> pools;
1182 void controlThread(int fd, ComboAddress local);
1183 vector<std::function<void(void)>> setupLua(bool client, const std::string& config);
1184 std::shared_ptr<ServerPool> getPool(const pools_t& pools, const std::string& poolName);
1185 std::shared_ptr<ServerPool> createPoolIfNotExists(pools_t& pools, const string& poolName);
1186 NumberedServerVector getDownstreamCandidates(const pools_t& pools, const std::string& poolName);
1188 std::shared_ptr<DownstreamState> firstAvailable(const NumberedServerVector& servers, const DNSQuestion* dq);
1190 std::shared_ptr<DownstreamState> leastOutstanding(const NumberedServerVector& servers, const DNSQuestion* dq);
1191 std::shared_ptr<DownstreamState> wrandom(const NumberedServerVector& servers, const DNSQuestion* dq);
1192 std::shared_ptr<DownstreamState> whashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1193 std::shared_ptr<DownstreamState> chashed(const NumberedServerVector& servers, const DNSQuestion* dq);
1194 std::shared_ptr<DownstreamState> roundrobin(const NumberedServerVector& servers, const DNSQuestion* dq);
1196 struct WebserverConfig
1198 std::string password;
1200 boost::optional<std::map<std::string, std::string> > customHeaders;
1204 void setWebserverAPIKey(const boost::optional<std::string> apiKey);
1205 void setWebserverPassword(const std::string& password);
1206 void setWebserverCustomHeaders(const boost::optional<std::map<std::string, std::string> > customHeaders);
1208 void dnsdistWebserverThread(int sock, const ComboAddress& local);
1209 void tcpAcceptorThread(void* p);
1210 #ifdef HAVE_DNS_OVER_HTTPS
1211 void dohThread(ClientState* cs);
1212 #endif /* HAVE_DNS_OVER_HTTPS */
1214 void setLuaNoSideEffect(); // if nothing has been declared, set that there are no side effects
1215 void setLuaSideEffect(); // set to report a side effect, cancelling all _no_ side effect calls
1216 bool getLuaNoSideEffect(); // set if there were only explicit declarations of _no_ side effect
1217 void resetLuaSideEffect(); // reset to indeterminate state
1219 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);
1220 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);
1221 bool processRulesResult(const DNSAction::Action& action, DNSQuestion& dq, std::string& ruleresult, bool& drop);
1223 bool checkQueryHeaders(const struct dnsheader* dh);
1225 extern std::vector<std::shared_ptr<DNSCryptContext>> g_dnsCryptLocals;
1226 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);
1227 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);
1229 bool addXPF(DNSQuestion& dq, uint16_t optionCode);
1231 uint16_t getRandomDNSID();
1233 #include "dnsdist-snmp.hh"
1235 extern bool g_snmpEnabled;
1236 extern bool g_snmpTrapsEnabled;
1237 extern DNSDistSNMPAgent* g_snmpAgent;
1238 extern bool g_addEDNSToSelfGeneratedResponses;
1240 static const size_t s_udpIncomingBufferSize{1500};
1242 enum class ProcessQueryResult { Drop, SendAnswer, PassToBackend };
1243 ProcessQueryResult processQuery(DNSQuestion& dq, ClientState& cs, LocalHolders& holders, std::shared_ptr<DownstreamState>& selectedBackend);
1245 DNSResponse makeDNSResponseFromIDState(IDState& ids, struct dnsheader* dh, size_t bufferSize, uint16_t responseLen, bool isTCP);
1246 void setIDStateFromDNSQuestion(IDState& ids, DNSQuestion& dq, DNSName&& qname);
1248 int pickBackendSocketForSending(std::shared_ptr<DownstreamState>& state);
1249 ssize_t udpClientSendRequestToBackend(const std::shared_ptr<DownstreamState>& ss, const int sd, const char* request, const size_t requestLen, bool healthCheck=false);