netwerk/dns/TRRQuery.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "TRRQuery.h"
   6
   7 #include "mozilla/StaticPrefs_network.h"
   8 #include "mozilla/Telemetry.h"
   9 #include "nsQueryObject.h"
  10 #include "TRR.h"
  11 #include "TRRService.h"
  12 // Put DNSLogging.h at the end to avoid LOG being overwritten by other headers.
  13 #include "DNSLogging.h"
  14
  15 namespace mozilla {
  16 namespace net {
  17
  18 static already_AddRefed<AddrInfo> merge_rrset(AddrInfo* rrto,
  19                                               AddrInfo* rrfrom) {
  20   MOZ_ASSERT(rrto && rrfrom);
  21   // Each of the arguments are all-IPv4 or all-IPv6 hence judging
  22   // by the first element. This is true only for TRR resolutions.
  23   bool isIPv6 = rrfrom->Addresses().Length() > 0 &&
  24                 rrfrom->Addresses()[0].raw.family == PR_AF_INET6;
  25
  26   nsTArray<NetAddr> addresses;
  27   if (isIPv6) {
  28     addresses = rrfrom->Addresses().Clone();
  29     addresses.AppendElements(rrto->Addresses());
  30   } else {
  31     addresses = rrto->Addresses().Clone();
  32     addresses.AppendElements(rrfrom->Addresses());
  33   }
  34   auto builder = rrto->Build();
  35   builder.SetAddresses(std::move(addresses));
  36   return builder.Finish();
  37 }
  38
  39 void TRRQuery::Cancel(nsresult aStatus) {
  40   MutexAutoLock trrlock(mTrrLock);
  41   if (mTrrA) {
  42     mTrrA->Cancel(aStatus);
  43   }
  44   if (mTrrAAAA) {
  45     mTrrAAAA->Cancel(aStatus);
  46   }
  47   if (mTrrByType) {
  48     mTrrByType->Cancel(aStatus);
  49   }
  50 }
  51
  52 void TRRQuery::MarkSendingTRR(TRR* trr, enum TrrType rectype, MutexAutoLock&) {
  53   if (rectype == TRRTYPE_A) {
  54     MOZ_ASSERT(!mTrrA);
  55     mTrrA = trr;
  56     mTrrAUsed = STARTED;
  57   } else if (rectype == TRRTYPE_AAAA) {
  58     MOZ_ASSERT(!mTrrAAAA);
  59     mTrrAAAA = trr;
  60     mTrrAAAAUsed = STARTED;
  61   } else {
  62     LOG(("TrrLookup called with bad type set: %d\n", rectype));
  63     MOZ_ASSERT(0);
  64   }
  65 }
  66
  67 void TRRQuery::PrepareQuery(enum TrrType aRecType,
  68                             nsTArray<RefPtr<TRR>>& aRequestsToSend) {
  69   LOG(("TRR Resolve %s type %d\n", mRecord->host.get(), (int)aRecType));
  70   RefPtr<TRR> trr = new TRR(this, mRecord, aRecType);
  71
  72   {
  73     MutexAutoLock trrlock(mTrrLock);
  74     MarkSendingTRR(trr, aRecType, trrlock);
  75     aRequestsToSend.AppendElement(trr);
  76   }
  77 }
  78
  79 bool TRRQuery::SendQueries(nsTArray<RefPtr<TRR>>& aRequestsToSend) {
  80   bool madeQuery = false;
  81   mTRRRequestCounter = aRequestsToSend.Length();
  82   for (const auto& request : aRequestsToSend) {
  83     if (NS_SUCCEEDED(TRRService::Get()->DispatchTRRRequest(request))) {
  84       madeQuery = true;
  85     } else {
  86       mTRRRequestCounter--;
  87       MutexAutoLock trrlock(mTrrLock);
  88       if (request == mTrrA) {
  89         mTrrA = nullptr;
  90         mTrrAUsed = INIT;
  91       }
  92       if (request == mTrrAAAA) {
  93         mTrrAAAA = nullptr;
  94         mTrrAAAAUsed = INIT;
  95       }
  96     }
  97   }
  98   aRequestsToSend.Clear();
  99   return madeQuery;
 100 }
 101
 102 nsresult TRRQuery::DispatchLookup(TRR* pushedTRR) {
 103   if (!mRecord->IsAddrRecord()) {
 104     return DispatchByTypeLookup(pushedTRR);
 105   }
 106
 107   RefPtr<AddrHostRecord> addrRec = do_QueryObject(mRecord);
 108   MOZ_ASSERT(addrRec);
 109   if (!addrRec) {
 110     return NS_ERROR_UNEXPECTED;
 111   }
 112
 113   mTrrStart = TimeStamp::Now();
 114
 115   mTrrAUsed = INIT;
 116   mTrrAAAAUsed = INIT;
 117
 118   // Always issue both A and AAAA.
 119   // When both are complete we filter out the unneeded results.
 120   enum TrrType rectype = (mRecord->af == AF_INET6) ? TRRTYPE_AAAA : TRRTYPE_A;
 121
 122   if (pushedTRR) {
 123     MutexAutoLock trrlock(mTrrLock);
 124     rectype = pushedTRR->Type();
 125     MarkSendingTRR(pushedTRR, rectype, trrlock);
 126     return NS_OK;
 127   }
 128
 129   // Need to dispatch TRR requests after |mTrrA| and |mTrrAAAA| are set
 130   // properly so as to avoid the race when CompleteLookup() is called at the
 131   // same time.
 132   nsTArray<RefPtr<TRR>> requestsToSend;
 133   if ((mRecord->af == AF_UNSPEC || mRecord->af == AF_INET6)) {
 134     PrepareQuery(TRRTYPE_AAAA, requestsToSend);
 135   }
 136   if (mRecord->af == AF_UNSPEC || mRecord->af == AF_INET) {
 137     PrepareQuery(TRRTYPE_A, requestsToSend);
 138   }
 139
 140   if (SendQueries(requestsToSend)) {
 141     return NS_OK;
 142   }
 143
 144   return NS_ERROR_UNKNOWN_HOST;
 145 }
 146
 147 nsresult TRRQuery::DispatchByTypeLookup(TRR* pushedTRR) {
 148   RefPtr<TypeHostRecord> typeRec = do_QueryObject(mRecord);
 149   MOZ_ASSERT(typeRec);
 150   if (!typeRec) {
 151     return NS_ERROR_UNEXPECTED;
 152   }
 153
 154   typeRec->mStart = TimeStamp::Now();
 155   enum TrrType rectype;
 156
 157   // XXX this could use a more extensible approach.
 158   if (mRecord->type == nsIDNSService::RESOLVE_TYPE_TXT) {
 159     rectype = TRRTYPE_TXT;
 160   } else if (mRecord->type == nsIDNSService::RESOLVE_TYPE_HTTPSSVC) {
 161     rectype = TRRTYPE_HTTPSSVC;
 162   } else if (pushedTRR) {
 163     rectype = pushedTRR->Type();
 164   } else {
 165     MOZ_ASSERT(false, "Not an expected request type");
 166     return NS_ERROR_UNKNOWN_HOST;
 167   }
 168
 169   LOG(("TRR Resolve %s type %d\n", typeRec->host.get(), (int)rectype));
 170   RefPtr<TRR> trr = pushedTRR ? pushedTRR : new TRR(this, mRecord, rectype);
 171
 172   if (pushedTRR || NS_SUCCEEDED(TRRService::Get()->DispatchTRRRequest(trr))) {
 173     MutexAutoLock trrlock(mTrrLock);
 174     MOZ_ASSERT(!mTrrByType);
 175     mTrrByType = trr;
 176     return NS_OK;
 177   }
 178
 179   return NS_ERROR_UNKNOWN_HOST;
 180 }
 181
 182 AHostResolver::LookupStatus TRRQuery::CompleteLookup(
 183     nsHostRecord* rec, nsresult status, AddrInfo* aNewRRSet, bool pb,
 184     const nsACString& aOriginsuffix, nsHostRecord::TRRSkippedReason aReason,
 185     TRR* aTRRRequest) {
 186   if (rec != mRecord) {
 187     LOG(("TRRQuery::CompleteLookup - Pushed record. Go to resolver"));
 188     return mHostResolver->CompleteLookup(rec, status, aNewRRSet, pb,
 189                                          aOriginsuffix, aReason, aTRRRequest);
 190   }
 191
 192   LOG(("TRRQuery::CompleteLookup > host: %s", rec->host.get()));
 193
 194   RefPtr<AddrInfo> newRRSet(aNewRRSet);
 195   DNSResolverType resolverType = newRRSet->ResolverType();
 196   {
 197     MutexAutoLock trrlock(mTrrLock);
 198     if (newRRSet->TRRType() == TRRTYPE_A) {
 199       MOZ_ASSERT(mTrrA);
 200       mTRRAFailReason = aReason;
 201       mTrrA = nullptr;
 202       mTrrAUsed = NS_SUCCEEDED(status) ? OK : FAILED;
 203       MOZ_ASSERT(!mAddrInfoA);
 204       mAddrInfoA = newRRSet;
 205       mAResult = status;
 206       LOG(("A query status: 0x%x", static_cast<uint32_t>(status)));
 207     } else if (newRRSet->TRRType() == TRRTYPE_AAAA) {
 208       MOZ_ASSERT(mTrrAAAA);
 209       mTRRAAAAFailReason = aReason;
 210       mTrrAAAA = nullptr;
 211       mTrrAAAAUsed = NS_SUCCEEDED(status) ? OK : FAILED;
 212       MOZ_ASSERT(!mAddrInfoAAAA);
 213       mAddrInfoAAAA = newRRSet;
 214       mAAAAResult = status;
 215       LOG(("AAAA query status: 0x%x", static_cast<uint32_t>(status)));
 216     } else {
 217       MOZ_ASSERT(0);
 218     }
 219   }
 220
 221   if (NS_SUCCEEDED(status)) {
 222     mTRRSuccess++;
 223     if (mTRRSuccess == 1) {
 224       // Store the duration on first succesful TRR response.  We
 225       // don't know that there will be a second response nor can we
 226       // tell which of two has useful data.
 227       mTrrDuration = TimeStamp::Now() - mTrrStart;
 228     }
 229   }
 230
 231   bool pendingRequest = false;
 232   if (mTRRRequestCounter) {
 233     mTRRRequestCounter--;
 234     pendingRequest = (mTRRRequestCounter != 0);
 235   } else {
 236     MOZ_DIAGNOSTIC_ASSERT(false, "Request counter is messed up");
 237   }
 238   if (pendingRequest) {  // There are other outstanding requests
 239     LOG(("CompleteLookup: waiting for all responses!\n"));
 240     return LOOKUP_OK;
 241   }
 242
 243   if (mRecord->af == AF_UNSPEC) {
 244     // merge successful records
 245     if (mTrrAUsed == OK) {
 246       LOG(("Have A response"));
 247       newRRSet = mAddrInfoA;
 248       status = mAResult;
 249       if (mTrrAAAAUsed == OK) {
 250         LOG(("Merging A and AAAA responses"));
 251         newRRSet = merge_rrset(newRRSet, mAddrInfoAAAA);
 252       }
 253     } else {
 254       newRRSet = mAddrInfoAAAA;
 255       status = mAAAAResult;
 256     }
 257
 258     if (NS_FAILED(status) && (mAAAAResult == NS_ERROR_DEFINITIVE_UNKNOWN_HOST ||
 259                               mAResult == NS_ERROR_DEFINITIVE_UNKNOWN_HOST)) {
 260       status = NS_ERROR_DEFINITIVE_UNKNOWN_HOST;
 261     }
 262   } else {
 263     // If this is a failed AAAA request, but the server only has a A record,
 264     // then we should not fallback to Do53. Instead we also send a A request
 265     // and return NS_ERROR_DEFINITIVE_UNKNOWN_HOST if that succeeds.
 266     if (NS_FAILED(status) && status != NS_ERROR_DEFINITIVE_UNKNOWN_HOST &&
 267         (mTrrAUsed == INIT || mTrrAAAAUsed == INIT)) {
 268       if (newRRSet->TRRType() == TRRTYPE_A) {
 269         LOG(("A lookup failed. Checking if AAAA record exists"));
 270         nsTArray<RefPtr<TRR>> requestsToSend;
 271         PrepareQuery(TRRTYPE_AAAA, requestsToSend);
 272         if (SendQueries(requestsToSend)) {
 273           LOG(("Sent AAAA request"));
 274           return LOOKUP_OK;
 275         }
 276       } else if (newRRSet->TRRType() == TRRTYPE_AAAA) {
 277         LOG(("AAAA lookup failed. Checking if A record exists"));
 278         nsTArray<RefPtr<TRR>> requestsToSend;
 279         PrepareQuery(TRRTYPE_A, requestsToSend);
 280         if (SendQueries(requestsToSend)) {
 281           LOG(("Sent A request"));
 282           return LOOKUP_OK;
 283         }
 284       } else {
 285         MOZ_ASSERT(false, "Unexpected family");
 286       }
 287     }
 288     bool otherSucceeded =
 289         mRecord->af == AF_INET6 ? mTrrAUsed == OK : mTrrAAAAUsed == OK;
 290     LOG(("TRRQuery::CompleteLookup other request succeeded"));
 291
 292     if (mRecord->af == AF_INET) {
 293       // return only A record
 294       newRRSet = mAddrInfoA;
 295       status = mAResult;
 296       if (NS_FAILED(status) &&
 297           (otherSucceeded || mAAAAResult == NS_ERROR_DEFINITIVE_UNKNOWN_HOST)) {
 298         LOG(("status set to NS_ERROR_DEFINITIVE_UNKNOWN_HOST"));
 299         status = NS_ERROR_DEFINITIVE_UNKNOWN_HOST;
 300       }
 301
 302     } else if (mRecord->af == AF_INET6) {
 303       // return only AAAA record
 304       newRRSet = mAddrInfoAAAA;
 305       status = mAAAAResult;
 306
 307       if (NS_FAILED(status) &&
 308           (otherSucceeded || mAResult == NS_ERROR_DEFINITIVE_UNKNOWN_HOST)) {
 309         LOG(("status set to NS_ERROR_DEFINITIVE_UNKNOWN_HOST"));
 310         status = NS_ERROR_DEFINITIVE_UNKNOWN_HOST;
 311       }
 312
 313     } else {
 314       MOZ_ASSERT(false, "Unexpected AF");
 315       return LOOKUP_OK;
 316     }
 317
 318     // If this record failed, but there is a record for the other AF
 319     // we prevent fallback to the native resolver.
 320   }
 321
 322   if (mTRRSuccess && mHostResolver->GetNCS() &&
 323       (mHostResolver->GetNCS()->GetNAT64() ==
 324        nsINetworkConnectivityService::OK) &&
 325       newRRSet) {
 326     newRRSet = mHostResolver->GetNCS()->MapNAT64IPs(newRRSet);
 327   }
 328
 329   if (resolverType == DNSResolverType::TRR) {
 330     if (mTrrAUsed == OK) {
 331       AccumulateCategoricalKeyed(
 332           TRRService::ProviderKey(),
 333           Telemetry::LABELS_DNS_LOOKUP_DISPOSITION3::trrAOK);
 334     } else if (mTrrAUsed == FAILED) {
 335       AccumulateCategoricalKeyed(
 336           TRRService::ProviderKey(),
 337           Telemetry::LABELS_DNS_LOOKUP_DISPOSITION3::trrAFail);
 338     }
 339
 340     if (mTrrAAAAUsed == OK) {
 341       AccumulateCategoricalKeyed(
 342           TRRService::ProviderKey(),
 343           Telemetry::LABELS_DNS_LOOKUP_DISPOSITION3::trrAAAAOK);
 344     } else if (mTrrAAAAUsed == FAILED) {
 345       AccumulateCategoricalKeyed(
 346           TRRService::ProviderKey(),
 347           Telemetry::LABELS_DNS_LOOKUP_DISPOSITION3::trrAAAAFail);
 348     }
 349   }
 350
 351   mAddrInfoAAAA = nullptr;
 352   mAddrInfoA = nullptr;
 353
 354   MOZ_DIAGNOSTIC_ASSERT(!mCalledCompleteLookup,
 355                         "must not call CompleteLookup more than once");
 356   mCalledCompleteLookup = true;
 357   return mHostResolver->CompleteLookup(rec, status, newRRSet, pb, aOriginsuffix,
 358                                        aReason, aTRRRequest);
 359 }
 360
 361 AHostResolver::LookupStatus TRRQuery::CompleteLookupByType(
 362     nsHostRecord* rec, nsresult status,
 363     mozilla::net::TypeRecordResultType& aResult, uint32_t aTtl, bool pb) {
 364   if (rec != mRecord) {
 365     LOG(("TRRQuery::CompleteLookup - Pushed record. Go to resolver"));
 366     return mHostResolver->CompleteLookupByType(rec, status, aResult, aTtl, pb);
 367   }
 368
 369   {
 370     MutexAutoLock trrlock(mTrrLock);
 371     mTrrByType = nullptr;
 372   }
 373
 374   MOZ_DIAGNOSTIC_ASSERT(!mCalledCompleteLookup,
 375                         "must not call CompleteLookup more than once");
 376   mCalledCompleteLookup = true;
 377   return mHostResolver->CompleteLookupByType(rec, status, aResult, aTtl, pb);
 378 }
 379
 380 }  // namespace net
 381 }  // namespace mozilla