2 // Use of this source code is governed by a BSD-style license that can be
25     "_services", "_dns-sd", "_udp"};
31   // enforce that new DnsTypes added must be added below through a compile-time  in GetTtlForNsecTargetingType()
45       // If no records are present, re-querying should happen at the minimum  in GetTtlForNsecTargetingType()
80   auto records = record_handler->GetRecords(domain, type, clazz);  in AddRecords()
112     message->AddAdditionalRecord(std::move(record));  in AddAdditionalRecords()
127     message->AddAnswer(std::move(record));  in AddResponseRecords()
152   // Per RFC 6763 section 12.1, when querying for a PTR record, all SRV records  in ApplyQueryResults()
155   // AAAA associated with the added SRV records. Per RFC 6762 section 6.1,  in ApplyQueryResults()
160     // Add all SRV and TXT records to the additional records section.  in ApplyQueryResults()
161     for (const MdnsRecord& record : message->answers()) {  in ApplyQueryResults()
164       const DomainName& target =  in ApplyQueryResults()  local
166       AddAdditionalRecords(message, record_handler, target, known_answers,  in ApplyQueryResults()
168       AddAdditionalRecords(message, record_handler, target, known_answers,  in ApplyQueryResults()
172     // Add A and AAAA records associated with an added SRV record to the  in ApplyQueryResults()
174     const int max = message->additional_records().size();  in ApplyQueryResults()
176       if (message->additional_records()[i].dns_type() != DnsType::kSRV) {  in ApplyQueryResults()
181         const MdnsRecord& srv_record = message->additional_records()[i];  in ApplyQueryResults()
182         const DomainName& target =  in ApplyQueryResults()  local
183             absl::get<SrvRecordRdata>(srv_record.rdata()).target();  in ApplyQueryResults()
184         AddAdditionalRecords(message, record_handler, target, known_answers,  in ApplyQueryResults()
185                              DnsType::kA, clazz, target == domain);  in ApplyQueryResults()
188       // Must re-calculate the |srv_record|, |target| refs in case a resize of  in ApplyQueryResults()
191         const MdnsRecord& srv_record = message->additional_records()[i];  in ApplyQueryResults()
192         const DomainName& target =  in ApplyQueryResults()  local
193             absl::get<SrvRecordRdata>(srv_record.rdata()).target();  in ApplyQueryResults()
194         AddAdditionalRecords(message, record_handler, target, known_answers,  in ApplyQueryResults()
195                              DnsType::kAAAA, clazz, target == domain);  in ApplyQueryResults()
199     // Per RFC 6763 section 12.2, when querying for an SRV record, all address  in ApplyQueryResults()
203     // response NSEC record may be added to show their non-existence.  in ApplyQueryResults()
204     for (const auto& srv_record : message->answers()) {  in ApplyQueryResults()
207       const DomainName& target =  in ApplyQueryResults()  local
208           absl::get<SrvRecordRdata>(srv_record.rdata()).target();  in ApplyQueryResults()
209       AddAdditionalRecords(message, record_handler, target, known_answers,  in ApplyQueryResults()
210                            DnsType::kA, clazz, target == domain);  in ApplyQueryResults()
211       AddAdditionalRecords(message, record_handler, target, known_answers,  in ApplyQueryResults()
212                            DnsType::kAAAA, clazz, target == domain);  in ApplyQueryResults()
218     // record should be added to show its non-existence.  in ApplyQueryResults()
263       record_handler->GetPtrRecords(clazz);  in ApplyServiceTypeEnumerationResults()
265   // skip "_services._dns-sd._udp." which was already checked for in above  in ApplyServiceTypeEnumerationResults()
274       message->AddAnswer(MdnsRecord(name, DnsType::kPTR, record.dns_class(),  in ApplyServiceTypeEnumerationResults()
348     send_delay = responder_->random_delay_->GetTruncatedQueryResponseDelay();  in RescheduleSend()
363   responder_->RespondToTruncatedQuery(this);  in SendResponse()
394   receiver_->SetQueryCallback(std::move(func));  in MdnsResponder()
398   receiver_->SetQueryCallback(nullptr);  in ~MdnsResponder()
403   OSP_DCHECK(task_runner_->IsRunningOnTaskRunner());  in OnMessageReceived()
406   // Handle multi-packet known answer suppression.  in OnMessageReceived()
410     // - A host on the network is misbehaving.  in OnMessageReceived()
411     // - There is a malicious actor on the network.  in OnMessageReceived()
417                    "new multi-packet known answer message as normal query";  in OnMessageReceived()
427     ownership_handler_->RespondToProbeQuery(message, src);  in OnMessageReceived()
443   OSP_DVLOG << "Multi-packet truncated message received. Processing...";  in ProcessMultiPacketTruncatedMessage()
451   std::unique_ptr<TruncatedQuery>& stored_query = pair.first->second;  in ProcessMultiPacketTruncatedMessage()
464   const bool are_questions_already_stored = !stored_query->questions().empty();  in ProcessMultiPacketTruncatedMessage()
470     stored_query->AddKnownAnswers(message.answers());  in ProcessMultiPacketTruncatedMessage()
475   // messages were received out-of-order and known answers have already been  in ProcessMultiPacketTruncatedMessage()
479     stored_query->SetQuery(message);  in ProcessMultiPacketTruncatedMessage()
485   // - The sender must have finished sending packets.  in ProcessMultiPacketTruncatedMessage()
486   // - The known answers completing this query somehow got lost on the network.  in ProcessMultiPacketTruncatedMessage()
487   // - A second truncated query was started by the same host, and this host  in ProcessMultiPacketTruncatedMessage()
500   new_query->SendResponse();  in ProcessMultiPacketTruncatedMessage()
504   ProcessQueries(query->src(), query->questions(), query->known_answers());  in RespondToTruncatedQuery()
505   auto it = truncated_queries_.find(query->src());  in RespondToTruncatedQuery()
513   if (it->second.get() == query) {  in RespondToTruncatedQuery()
533     // - This host is the sole owner of that domain.  in ProcessQueries()
534     // - A record corresponding to this question has been published.  in ProcessQueries()
535     // - The query is a service enumeration query.  in ProcessQueries()
538         ownership_handler_->IsDomainClaimed(question.name());  in ProcessQueries()
540         !record_handler_->HasRecords(question.name(), question.dns_type(),  in ProcessQueries()
553         sender_->SendMulticast(message);  in ProcessQueries()
558         sender_->SendMessage(message, src);  in ProcessQueries()
568       const auto delay = random_delay_->GetSharedRecordResponseDelay();  in ProcessQueries()
574       task_runner_->PostTaskWithDelay(response, delay);  in ProcessQueries()
584   OSP_DCHECK(task_runner_->IsRunningOnTaskRunner());  in SendResponse()