/*
    LEAmDNS_Control.cpp

    License (MIT license):
      Permission is hereby granted, free of charge, to any person obtaining a copy
      of this software and associated documentation files (the "Software"), to deal
      in the Software without restriction, including without limitation the rights
      to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      copies of the Software, and to permit persons to whom the Software is
      furnished to do so, subject to the following conditions:

      The above copyright notice and this permission notice shall be included in
      all copies or substantial portions of the Software.

      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
      THE SOFTWARE.

*/

#include <sys/time.h>
#include <IPAddress.h>
#include <AddrList.h>
#include <lwip/ip_addr.h>
#include <WString.h>
#include <cstdint>

/*
    ESP8266mDNS Control.cpp
*/

extern "C" {
#include "user_interface.h"
}

#include "LEAmDNS_lwIPdefs.h"
#include "LEAmDNS_Priv.h"

namespace esp8266
{
/*
    LEAmDNS
*/
namespace MDNSImplementation
{

/**
    CONTROL
*/


/**
    MAINTENANCE
*/

/*
    MDNSResponder::_process

    Run the MDNS process.
    Is called, every time the UDPContext receives data AND
    should be called in every 'loop' by calling 'MDNS::update()'.

*/
bool MDNSResponder::_process(bool p_bUserContext)
{

    bool    bResult = true;

    if (!p_bUserContext)
    {

        if ((m_pUDPContext) &&          // UDPContext available AND
                (m_pUDPContext->next()))    // has content
        {

            //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _update: Calling _parseMessage\n")););
            bResult = _parseMessage();
            //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parsePacket %s\n"), (bResult ? "succeeded" : "FAILED")););
        }
    }
    else
    {
        bResult = (m_netif != nullptr) &&
                  (m_netif->flags & NETIF_FLAG_UP) &&  // network interface is up and running
                  _updateProbeStatus() &&              // Probing
                  _checkServiceQueryCache();           // Service query cache check
    }
    return bResult;
}

/*
    MDNSResponder::_restart
*/
bool MDNSResponder::_restart(void)
{

    return ((m_netif != nullptr) &&
            (m_netif->flags & NETIF_FLAG_UP) &&  // network interface is up and running
            (_resetProbeStatus(true)) &&         // Stop and restart probing
            (_allocUDPContext()));               // Restart UDP
}


/**
    RECEIVING
*/

/*
    MDNSResponder::_parseMessage
*/
bool MDNSResponder::_parseMessage(void)
{
    DEBUG_EX_INFO(
        unsigned long   ulStartTime = millis();
        unsigned        uStartMemory = ESP.getFreeHeap();
        DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseMessage (Time: %lu ms, heap: %u bytes, from %s(%u), to %s(%u))\n"), ulStartTime, uStartMemory,
                              IPAddress(m_pUDPContext->getRemoteAddress()).toString().c_str(), m_pUDPContext->getRemotePort(),
                              IPAddress(m_pUDPContext->getDestAddress()).toString().c_str(), m_pUDPContext->getLocalPort());
    );
    //DEBUG_EX_INFO(_udpDump(););

    bool    bResult = false;

    stcMDNS_MsgHeader   header;
    if (_readMDNSMsgHeader(header))
    {
        if (0 == header.m_4bOpcode)     // A standard query
        {
            if (header.m_1bQR)          // Received a response -> answers to a query
            {
                //DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseMessage: Reading answers: ID:%u, Q:%u, A:%u, NS:%u, AR:%u\n"), header.m_u16ID, header.m_u16QDCount, header.m_u16ANCount, header.m_u16NSCount, header.m_u16ARCount););
                bResult = _parseResponse(header);
            }
            else                        // Received a query (Questions)
            {
                //DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseMessage: Reading query: ID:%u, Q:%u, A:%u, NS:%u, AR:%u\n"), header.m_u16ID, header.m_u16QDCount, header.m_u16ANCount, header.m_u16NSCount, header.m_u16ARCount););
                bResult = _parseQuery(header);
            }
        }
        else
        {
            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseMessage: Received UNEXPECTED opcode:%u. Ignoring message!\n"), header.m_4bOpcode););
            m_pUDPContext->flush();
        }
    }
    else
    {
        DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseMessage: FAILED to read header\n")););
        m_pUDPContext->flush();
    }
    DEBUG_EX_INFO(
        unsigned    uFreeHeap = ESP.getFreeHeap();
        DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseMessage: Done (%s after %lu ms, ate %i bytes, remaining %u)\n\n"), (bResult ? "Succeeded" : "FAILED"), (millis() - ulStartTime), (uStartMemory - uFreeHeap), uFreeHeap);
    );
    return bResult;
}

/*
    MDNSResponder::_parseQuery

    Queries are of interest in two cases:
    1. allow for tiebreaking while probing in the case of a race condition between two instances probing for
      the same name at the same time
    2. provide answers to questions for our host domain or any presented service

    When reading the questions, a set of (planned) responses is created, eg. a reverse PTR question for the host domain
    gets an A (IP address) response, a PTR question for the _services._dns-sd domain gets a PTR (type) response for any
    registered service, ...

    As any mDNS responder should be able to handle 'legacy' queries (from DNS clients), this case is handled here also.
    Legacy queries have got only one (unicast) question and are directed to the local DNS port (not the multicast port).

    1.
*/
bool MDNSResponder::_parseQuery(const MDNSResponder::stcMDNS_MsgHeader& p_MsgHeader)
{

    bool    bResult = true;

    stcMDNSSendParameter    sendParameter;
    uint8_t                 u8HostOrServiceReplies = 0;
    for (uint16_t qd = 0; ((bResult) && (qd < p_MsgHeader.m_u16QDCount)); ++qd)
    {

        stcMDNS_RRQuestion  questionRR;
        if ((bResult = _readRRQuestion(questionRR)))
        {
            // Define host replies, BUT only answer queries after probing is done
            u8HostOrServiceReplies =
                sendParameter.m_u8HostReplyMask |= (((m_bPassivModeEnabled) ||
                                                    (ProbingStatus_Done == m_HostProbeInformation.m_ProbingStatus))
                                                    ? _replyMaskForHost(questionRR.m_Header, 0)
                                                    : 0);
            DEBUG_EX_INFO(if (u8HostOrServiceReplies)
        {
            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Host reply needed 0x%X\n"), u8HostOrServiceReplies);
            });

            // Check tiebreak need for host domain
            if (ProbingStatus_InProgress == m_HostProbeInformation.m_ProbingStatus)
            {
                bool    bFullNameMatch = false;
                if ((_replyMaskForHost(questionRR.m_Header, &bFullNameMatch)) &&
                        (bFullNameMatch))
                {
                    // We're in 'probing' state and someone is asking for our host domain: this might be
                    // a race-condition: Two host with the same domain names try simutanously to probe their domains
                    // See: RFC 6762, 8.2 (Tiebraking)
                    // However, we're using a max. reduced approach for tiebreaking here: The higher IP-address wins!
                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Possible race-condition for host domain detected while probing.\n")););

                    m_HostProbeInformation.m_bTiebreakNeeded = true;
                }
            }

            // Define service replies
            for (stcMDNSService* pService = m_pServices; pService; pService = pService->m_pNext)
            {
                // Define service replies, BUT only answer queries after probing is done
                uint8_t u8ReplyMaskForQuestion = (((m_bPassivModeEnabled) ||
                                                   (ProbingStatus_Done == pService->m_ProbeInformation.m_ProbingStatus))
                                                  ? _replyMaskForService(questionRR.m_Header, *pService, 0)
                                                  : 0);
                u8HostOrServiceReplies |= (pService->m_u8ReplyMask |= u8ReplyMaskForQuestion);
                DEBUG_EX_INFO(if (u8ReplyMaskForQuestion)
            {
                DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Service reply needed for (%s.%s.%s): 0x%X (%s)\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol, u8ReplyMaskForQuestion, IPAddress(m_pUDPContext->getRemoteAddress()).toString().c_str());
                });

                // Check tiebreak need for service domain
                if (ProbingStatus_InProgress == pService->m_ProbeInformation.m_ProbingStatus)
                {
                    bool    bFullNameMatch = false;
                    if ((_replyMaskForService(questionRR.m_Header, *pService, &bFullNameMatch)) &&
                            (bFullNameMatch))
                    {
                        // We're in 'probing' state and someone is asking for this service domain: this might be
                        // a race-condition: Two services with the same domain names try simutanously to probe their domains
                        // See: RFC 6762, 8.2 (Tiebraking)
                        // However, we're using a max. reduced approach for tiebreaking here: The 'higher' SRV host wins!
                        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Possible race-condition for service domain %s.%s.%s detected while probing.\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol););

                        pService->m_ProbeInformation.m_bTiebreakNeeded = true;
                    }
                }
            }

            // Handle unicast and legacy specialities
            // If only one question asks for unicast reply, the whole reply packet is send unicast
            if (((DNS_MQUERY_PORT != m_pUDPContext->getRemotePort()) ||     // Unicast (maybe legacy) query OR
                    (questionRR.m_bUnicast)) &&                                // Expressivly unicast query
                    (!sendParameter.m_bUnicast))
            {

                sendParameter.m_bUnicast = true;
                sendParameter.m_bCacheFlush = false;
                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Unicast response for %s!\n"), IPAddress(m_pUDPContext->getRemoteAddress()).toString().c_str()););

                if ((DNS_MQUERY_PORT != m_pUDPContext->getRemotePort()) &&  // Unicast (maybe legacy) query AND
                        (1 == p_MsgHeader.m_u16QDCount) &&                          // Only one question AND
                        ((sendParameter.m_u8HostReplyMask) ||                       //  Host replies OR
                         (u8HostOrServiceReplies)))                                 //  Host or service replies available
                {
                    // We're a match for this legacy query, BUT
                    // make sure, that the query comes from a local host
                    ip_info IPInfo_Local;
                    ip_info IPInfo_Remote;
                    if (((IPInfo_Remote.ip.addr = m_pUDPContext->getRemoteAddress())) &&
                            (((wifi_get_ip_info(SOFTAP_IF, &IPInfo_Local)) &&
                              (ip4_addr_netcmp(&IPInfo_Remote.ip, &IPInfo_Local.ip, &IPInfo_Local.netmask))) ||  // Remote IP in SOFTAP's subnet OR
                             ((wifi_get_ip_info(STATION_IF, &IPInfo_Local)) &&
                              (ip4_addr_netcmp(&IPInfo_Remote.ip, &IPInfo_Local.ip, &IPInfo_Local.netmask)))))   // Remote IP in STATION's subnet
                    {

                        DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Legacy query from local host %s, id %u!\n"), IPAddress(m_pUDPContext->getRemoteAddress()).toString().c_str(), p_MsgHeader.m_u16ID););

                        sendParameter.m_u16ID = p_MsgHeader.m_u16ID;
                        sendParameter.m_bLegacyQuery = true;
                        sendParameter.m_pQuestions = new stcMDNS_RRQuestion;
                        if ((bResult = (0 != sendParameter.m_pQuestions)))
                        {
                            sendParameter.m_pQuestions->m_Header.m_Domain = questionRR.m_Header.m_Domain;
                            sendParameter.m_pQuestions->m_Header.m_Attributes.m_u16Type = questionRR.m_Header.m_Attributes.m_u16Type;
                            sendParameter.m_pQuestions->m_Header.m_Attributes.m_u16Class = questionRR.m_Header.m_Attributes.m_u16Class;
                        }
                        else
                        {
                            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: FAILED to add legacy question!\n")););
                        }
                    }
                    else
                    {
                        DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Legacy query from NON-LOCAL host!\n")););
                        bResult = false;
                    }
                }
            }
        }
        else
        {
            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: FAILED to read question!\n")););
        }
    }   // for questions

    //DEBUG_EX_INFO(if (u8HostOrServiceReplies) { DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Reply needed: %u (%s: %s->%s)\n"), u8HostOrServiceReplies, clsTimeSyncer::timestr(), IPAddress(m_pUDPContext->getRemoteAddress()).toString().c_str(), IPAddress(m_pUDPContext->getDestAddress()).toString().c_str()); } );

    // Handle known answers
    uint32_t    u32Answers = (p_MsgHeader.m_u16ANCount + p_MsgHeader.m_u16NSCount + p_MsgHeader.m_u16ARCount);
    DEBUG_EX_INFO(if ((u8HostOrServiceReplies) && (u32Answers))
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Known answers(%u):\n"), u32Answers);
    });

    for (uint32_t an = 0; ((bResult) && (an < u32Answers)); ++an)
    {
        stcMDNS_RRAnswer*   pKnownRRAnswer = 0;
        if (((bResult = _readRRAnswer(pKnownRRAnswer))) &&
                (pKnownRRAnswer))
        {

            if ((DNS_RRTYPE_ANY != pKnownRRAnswer->m_Header.m_Attributes.m_u16Type) &&      // No ANY type answer
                    (DNS_RRCLASS_ANY != pKnownRRAnswer->m_Header.m_Attributes.m_u16Class))      // No ANY class answer
            {

                // Find match between planned answer (sendParameter.m_u8HostReplyMask) and this 'known answer'
                uint8_t u8HostMatchMask = (sendParameter.m_u8HostReplyMask & _replyMaskForHost(pKnownRRAnswer->m_Header));
                if ((u8HostMatchMask) &&                                            // The RR in the known answer matches an RR we are planning to send, AND
                        ((MDNS_HOST_TTL / 2) <= pKnownRRAnswer->m_u32TTL))              // The TTL of the known answer is longer than half of the new host TTL (120s)
                {

                    // Compare contents
                    if (AnswerType_PTR == pKnownRRAnswer->answerType())
                    {
                        stcMDNS_RRDomain    hostDomain;
                        if ((_buildDomainForHost(m_pcHostname, hostDomain)) &&
                                (((stcMDNS_RRAnswerPTR*)pKnownRRAnswer)->m_PTRDomain == hostDomain))
                        {
                            // Host domain match
#ifdef MDNS_IP4_SUPPORT
                            if (u8HostMatchMask & ContentFlag_PTR_IP4)
                            {
                                // IP4 PTR was asked for, but is already known -> skipping
                                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: IP4 PTR already known... skipping!\n")););
                                sendParameter.m_u8HostReplyMask &= ~ContentFlag_PTR_IP4;
                            }
#endif
#ifdef MDNS_IP6_SUPPORT
                            if (u8HostMatchMask & ContentFlag_PTR_IP6)
                            {
                                // IP6 PTR was asked for, but is already known -> skipping
                                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: IP6 PTR already known... skipping!\n")););
                                sendParameter.m_u8HostReplyMask &= ~ContentFlag_PTR_IP6;
                            }
#endif
                        }
                    }
                    else if (u8HostMatchMask & ContentFlag_A)
                    {
                        // IP4 address was asked for
#ifdef MDNS_IP4_SUPPORT
                        if ((AnswerType_A == pKnownRRAnswer->answerType()) &&
                                (((stcMDNS_RRAnswerA*)pKnownRRAnswer)->m_IPAddress == _getResponseMulticastInterface()))
                        {

                            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: IP4 address already known... skipping!\n")););
                            sendParameter.m_u8HostReplyMask &= ~ContentFlag_A;
                        }   // else: RData NOT IP4 length !!
#endif
                    }
                    else if (u8HostMatchMask & ContentFlag_AAAA)
                    {
                        // IP6 address was asked for
#ifdef MDNS_IP6_SUPPORT
                        if ((AnswerType_AAAA == pAnswerRR->answerType()) &&
                                (((stcMDNS_RRAnswerAAAA*)pAnswerRR)->m_IPAddress == _getResponseMulticastInterface()))
                        {

                            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: IP6 address already known... skipping!\n")););
                            sendParameter.m_u8HostReplyMask &= ~ContentFlag_AAAA;
                        }   // else: RData NOT IP6 length !!
#endif
                    }
                }   // Host match /*and TTL*/

                //
                // Check host tiebreak possibility
                if (m_HostProbeInformation.m_bTiebreakNeeded)
                {
                    stcMDNS_RRDomain    hostDomain;
                    if ((_buildDomainForHost(m_pcHostname, hostDomain)) &&
                            (pKnownRRAnswer->m_Header.m_Domain == hostDomain))
                    {
                        // Host domain match
#ifdef MDNS_IP4_SUPPORT
                        if (AnswerType_A == pKnownRRAnswer->answerType())
                        {
                            IPAddress   localIPAddress(_getResponseMulticastInterface());
                            if (((stcMDNS_RRAnswerA*)pKnownRRAnswer)->m_IPAddress == localIPAddress)
                            {
                                // SAME IP address -> We've received an old message from ourselfs (same IP)
                                DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Tiebreak (IP4) WON (was an old message)!\n")););
                                m_HostProbeInformation.m_bTiebreakNeeded = false;
                            }
                            else
                            {
                                if ((uint32_t)(((stcMDNS_RRAnswerA*)pKnownRRAnswer)->m_IPAddress) > (uint32_t)localIPAddress)   // The OTHER IP is 'higher' -> LOST
                                {
                                    // LOST tiebreak
                                    DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Tiebreak (IP4) LOST (lower)!\n")););
                                    _cancelProbingForHost();
                                    m_HostProbeInformation.m_bTiebreakNeeded = false;
                                }
                                else    // WON tiebreak
                                {
                                    //TiebreakState = TiebreakState_Won;    // We received an 'old' message from ourselfs -> Just ignore
                                    DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Tiebreak (IP4) WON (higher IP)!\n")););
                                    m_HostProbeInformation.m_bTiebreakNeeded = false;
                                }
                            }
                        }
#endif
#ifdef MDNS_IP6_SUPPORT
                        if (AnswerType_AAAA == pAnswerRR->answerType())
                        {
                            // TODO
                        }
#endif
                    }
                }   // Host tiebreak possibility

                // Check service answers
                for (stcMDNSService* pService = m_pServices; pService; pService = pService->m_pNext)
                {

                    uint8_t u8ServiceMatchMask = (pService->m_u8ReplyMask & _replyMaskForService(pKnownRRAnswer->m_Header, *pService));

                    if ((u8ServiceMatchMask) &&                                 // The RR in the known answer matches an RR we are planning to send, AND
                            ((MDNS_SERVICE_TTL / 2) <= pKnownRRAnswer->m_u32TTL))   // The TTL of the known answer is longer than half of the new service TTL (4500s)
                    {

                        if (AnswerType_PTR == pKnownRRAnswer->answerType())
                        {
                            stcMDNS_RRDomain    serviceDomain;
                            if ((u8ServiceMatchMask & ContentFlag_PTR_TYPE) &&
                                    (_buildDomainForService(*pService, false, serviceDomain)) &&
                                    (serviceDomain == ((stcMDNS_RRAnswerPTR*)pKnownRRAnswer)->m_PTRDomain))
                            {
                                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Service type PTR already known... skipping!\n")););
                                pService->m_u8ReplyMask &= ~ContentFlag_PTR_TYPE;
                            }
                            if ((u8ServiceMatchMask & ContentFlag_PTR_NAME) &&
                                    (_buildDomainForService(*pService, true, serviceDomain)) &&
                                    (serviceDomain == ((stcMDNS_RRAnswerPTR*)pKnownRRAnswer)->m_PTRDomain))
                            {
                                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Service name PTR already known... skipping!\n")););
                                pService->m_u8ReplyMask &= ~ContentFlag_PTR_NAME;
                            }
                        }
                        else if (u8ServiceMatchMask & ContentFlag_SRV)
                        {
                            DEBUG_EX_ERR(if (AnswerType_SRV != pKnownRRAnswer->answerType()) DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: ERROR! INVALID answer type (SRV)!\n")););
                            stcMDNS_RRDomain    hostDomain;
                            if ((_buildDomainForHost(m_pcHostname, hostDomain)) &&
                                    (hostDomain == ((stcMDNS_RRAnswerSRV*)pKnownRRAnswer)->m_SRVDomain))    // Host domain match
                            {

                                if ((MDNS_SRV_PRIORITY == ((stcMDNS_RRAnswerSRV*)pKnownRRAnswer)->m_u16Priority) &&
                                        (MDNS_SRV_WEIGHT == ((stcMDNS_RRAnswerSRV*)pKnownRRAnswer)->m_u16Weight) &&
                                        (pService->m_u16Port == ((stcMDNS_RRAnswerSRV*)pKnownRRAnswer)->m_u16Port))
                                {

                                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Service SRV answer already known... skipping!\n")););
                                    pService->m_u8ReplyMask &= ~ContentFlag_SRV;
                                }   // else: Small differences -> send update message
                            }
                        }
                        else if (u8ServiceMatchMask & ContentFlag_TXT)
                        {
                            DEBUG_EX_ERR(if (AnswerType_TXT != pKnownRRAnswer->answerType()) DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: ERROR! INVALID answer type (TXT)!\n")););
                            _collectServiceTxts(*pService);
                            if (pService->m_Txts == ((stcMDNS_RRAnswerTXT*)pKnownRRAnswer)->m_Txts)
                            {
                                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Service TXT answer already known... skipping!\n")););
                                pService->m_u8ReplyMask &= ~ContentFlag_TXT;
                            }
                            _releaseTempServiceTxts(*pService);
                        }
                    }   // Service match and enough TTL

                    //
                    // Check service tiebreak possibility
                    if (pService->m_ProbeInformation.m_bTiebreakNeeded)
                    {
                        stcMDNS_RRDomain    serviceDomain;
                        if ((_buildDomainForService(*pService, true, serviceDomain)) &&
                                (pKnownRRAnswer->m_Header.m_Domain == serviceDomain))
                        {
                            // Service domain match
                            if (AnswerType_SRV == pKnownRRAnswer->answerType())
                            {
                                stcMDNS_RRDomain    hostDomain;
                                if ((_buildDomainForHost(m_pcHostname, hostDomain)) &&
                                        (hostDomain == ((stcMDNS_RRAnswerSRV*)pKnownRRAnswer)->m_SRVDomain))    // Host domain match
                                {

                                    // We've received an old message from ourselfs (same SRV)
                                    DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Tiebreak (SRV) won (was an old message)!\n")););
                                    pService->m_ProbeInformation.m_bTiebreakNeeded = false;
                                }
                                else
                                {
                                    if (((stcMDNS_RRAnswerSRV*)pKnownRRAnswer)->m_SRVDomain > hostDomain)   // The OTHER domain is 'higher' -> LOST
                                    {
                                        // LOST tiebreak
                                        DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Tiebreak (SRV) LOST (lower)!\n")););
                                        _cancelProbingForService(*pService);
                                        pService->m_ProbeInformation.m_bTiebreakNeeded = false;
                                    }
                                    else    // WON tiebreak
                                    {
                                        //TiebreakState = TiebreakState_Won;    // We received an 'old' message from ourselfs -> Just ignore
                                        DEBUG_EX_RX(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Tiebreak (SRV) won (higher)!\n")););
                                        pService->m_ProbeInformation.m_bTiebreakNeeded = false;
                                    }
                                }
                            }
                        }
                    }   // service tiebreak possibility
                }   // for services
            }   // ANY answers
        }
        else
        {
            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: FAILED to read known answer!\n")););
        }

        if (pKnownRRAnswer)
        {
            delete pKnownRRAnswer;
            pKnownRRAnswer = 0;
        }
    }   // for answers

    if (bResult)
    {
        // Check, if a reply is needed
        uint8_t u8ReplyNeeded = sendParameter.m_u8HostReplyMask;
        for (stcMDNSService* pService = m_pServices; pService; pService = pService->m_pNext)
        {
            u8ReplyNeeded |= pService->m_u8ReplyMask;
        }

        if (u8ReplyNeeded)
        {
            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Sending answer(0x%X)...\n"), u8ReplyNeeded););

            sendParameter.m_bResponse = true;
            sendParameter.m_bAuthorative = true;

            bResult = _sendMDNSMessage(sendParameter);
        }
        DEBUG_EX_INFO(
            else
        {
            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: No reply needed\n"));
        }
        );
    }
    else
    {
        DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: Something FAILED!\n")););
        m_pUDPContext->flush();
    }

    //
    // Check and reset tiebreak-states
    if (m_HostProbeInformation.m_bTiebreakNeeded)
    {
        DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: UNSOLVED tiebreak-need for host domain!\n")););
        m_HostProbeInformation.m_bTiebreakNeeded = false;
    }
    for (stcMDNSService* pService = m_pServices; pService; pService = pService->m_pNext)
    {
        if (pService->m_ProbeInformation.m_bTiebreakNeeded)
        {
            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: UNSOLVED tiebreak-need for service domain (%s.%s.%s)\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol););
            pService->m_ProbeInformation.m_bTiebreakNeeded = false;
        }
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseQuery: FAILED!\n"));
    });
    return bResult;
}

/*
    MDNSResponder::_parseResponse

    Responses are of interest in two cases:
    1. find domain name conflicts while probing
    2. get answers to service queries

    In both cases any included questions are ignored

    1. If any answer has a domain name similar to one of the domain names we're planning to use (and are probing for),
      then we've got a 'probing conflict'. The conflict has to be solved on our side of the conflict (eg. by
      setting a new hostname and restart probing). The callback 'm_fnProbeResultCallback' is called with
      'p_bProbeResult=false' in this case.

    2. Service queries like '_http._tcp.local' will (if available) produce PTR, SRV, TXT and A/AAAA answers.
      All stored answers are pivoted by the service instance name (from the PTR record). Other answer parts,
      like host domain or IP address are than attached to this element.
      Any answer part carries a TTL, this is also stored (incl. the reception time); if the TTL is '0' the
      answer (part) is withdrawn by the sender and should be removed from any cache. RFC 6762, 10.1 proposes to
      set the caches TTL-value to 1 second in such a case and to delete the item only, if no update has
      has taken place in this second.
      Answer parts may arrive in 'unsorted' order, so they are grouped into three levels:
      Level 1: PRT - names the service instance (and is used as pivot), voids all other parts if is withdrawn or outdates
      Level 2: SRV - links the instance name to a host domain and port, voids A/AAAA parts if is withdrawn or outdates
               TXT - links the instance name to services TXTs
      Level 3: A/AAAA - links the host domain to an IP address
*/
bool MDNSResponder::_parseResponse(const MDNSResponder::stcMDNS_MsgHeader& p_MsgHeader)
{
    //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse\n")););
    //DEBUG_EX_INFO(_udpDump(););

    bool    bResult = false;

    // A response should be the result of a query or a probe
    if ((_hasServiceQueriesWaitingForAnswers()) ||          // Waiting for query answers OR
            (_hasProbesWaitingForAnswers()))                    // Probe responses
    {

        DEBUG_EX_INFO(
            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: Received a response\n"));
            //_udpDump();
        );

        bResult = true;
        //
        // Ignore questions here
        stcMDNS_RRQuestion  dummyRRQ;
        for (uint16_t qd = 0; ((bResult) && (qd < p_MsgHeader.m_u16QDCount)); ++qd)
        {
            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: Received a response containing a question... ignoring!\n")););
            bResult = _readRRQuestion(dummyRRQ);
        }   // for queries

        //
        // Read and collect answers
        stcMDNS_RRAnswer*   pCollectedRRAnswers = 0;
        uint32_t            u32NumberOfAnswerRRs = (p_MsgHeader.m_u16ANCount + p_MsgHeader.m_u16NSCount + p_MsgHeader.m_u16ARCount);
        for (uint32_t an = 0; ((bResult) && (an < u32NumberOfAnswerRRs)); ++an)
        {
            stcMDNS_RRAnswer*   pRRAnswer = 0;
            if (((bResult = _readRRAnswer(pRRAnswer))) &&
                    (pRRAnswer))
            {
                //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: ADDING answer!\n")););
                pRRAnswer->m_pNext = pCollectedRRAnswers;
                pCollectedRRAnswers = pRRAnswer;
            }
            else
            {
                DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: FAILED to read answer!\n")););
                if (pRRAnswer)
                {
                    delete pRRAnswer;
                    pRRAnswer = 0;
                }
                bResult = false;
            }
        }   // for answers

        //
        // Process answers
        if (bResult)
        {
            bResult = ((!pCollectedRRAnswers) ||
                       (_processAnswers(pCollectedRRAnswers)));
        }
        else    // Some failure while reading answers
        {
            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: FAILED to read answers!\n")););
            m_pUDPContext->flush();
        }

        // Delete collected answers
        while (pCollectedRRAnswers)
        {
            //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: DELETING answer!\n")););
            stcMDNS_RRAnswer*   pNextAnswer = pCollectedRRAnswers->m_pNext;
            delete pCollectedRRAnswers;
            pCollectedRRAnswers = pNextAnswer;
        }
    }
    else    // Received an unexpected response -> ignore
    {
        /*  DEBUG_EX_INFO(
                DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: Received an unexpected response... ignoring!\nDUMP:\n"));
                bool    bDumpResult = true;
                for (uint16_t qd=0; ((bDumpResult) && (qd<p_MsgHeader.m_u16QDCount)); ++qd) {
                    stcMDNS_RRQuestion  questionRR;
                    bDumpResult = _readRRQuestion(questionRR);
                    esp_yield();
                }   // for questions
                // Handle known answers
                uint32_t    u32Answers = (p_MsgHeader.m_u16ANCount + p_MsgHeader.m_u16NSCount + p_MsgHeader.m_u16ARCount);
                for (uint32_t an=0; ((bDumpResult) && (an<u32Answers)); ++an) {
                    stcMDNS_RRAnswer*   pRRAnswer = 0;
                    bDumpResult = _readRRAnswer(pRRAnswer);
                    if (pRRAnswer) {
                        delete pRRAnswer;
                        pRRAnswer = 0;
                    }
                    esp_yield();
                }
            );*/
        m_pUDPContext->flush();
        bResult = true;
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _parseResponse: FAILED!\n"));
    });
    return bResult;
}

/*
    MDNSResponder::_processAnswers
    Host:
    A (0x01):               eg. esp8266.local A OP TTL 123.456.789.012
    AAAA (01Cx):            eg. esp8266.local AAAA OP TTL 1234:5678::90
    PTR (0x0C, IP4):        eg. 012.789.456.123.in-addr.arpa PTR OP TTL esp8266.local
    PTR (0x0C, IP6):        eg. 90.0.0.0.0.0.0.0.0.0.0.0.78.56.34.12.ip6.arpa PTR OP TTL esp8266.local
    Service:
    PTR (0x0C, srv name):   eg. _http._tcp.local PTR OP TTL MyESP._http._tcp.local
    PTR (0x0C, srv type):   eg. _services._dns-sd._udp.local PTR OP TTL _http._tcp.local
    SRV (0x21):             eg. MyESP._http._tcp.local SRV OP TTL PRIORITY WEIGHT PORT esp8266.local
    TXT (0x10):             eg. MyESP._http._tcp.local TXT OP TTL c#=1

*/
bool MDNSResponder::_processAnswers(const MDNSResponder::stcMDNS_RRAnswer* p_pAnswers)
{

    bool    bResult = false;

    if (p_pAnswers)
    {
        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAnswers: Processing answers...\n")););
        bResult = true;

        // Answers may arrive in an unexpected order. So we loop our answers as long, as we
        // can connect new information to service queries
        bool    bFoundNewKeyAnswer;
        do
        {
            bFoundNewKeyAnswer = false;

            const stcMDNS_RRAnswer* pRRAnswer = p_pAnswers;
            while ((pRRAnswer) &&
                    (bResult))
            {
                // 1. level answer (PTR)
                if (AnswerType_PTR == pRRAnswer->answerType())
                {
                    // eg. _http._tcp.local PTR xxxx xx MyESP._http._tcp.local
                    bResult = _processPTRAnswer((stcMDNS_RRAnswerPTR*)pRRAnswer, bFoundNewKeyAnswer);   // May 'enable' new SRV or TXT answers to be linked to queries
                }
                // 2. level answers
                // SRV -> host domain and port
                else if (AnswerType_SRV == pRRAnswer->answerType())
                {
                    // eg. MyESP_http._tcp.local SRV xxxx xx yy zz 5000 esp8266.local
                    bResult = _processSRVAnswer((stcMDNS_RRAnswerSRV*)pRRAnswer, bFoundNewKeyAnswer);   // May 'enable' new A/AAAA answers to be linked to queries
                }
                // TXT -> Txts
                else if (AnswerType_TXT == pRRAnswer->answerType())
                {
                    // eg. MyESP_http._tcp.local TXT xxxx xx c#=1
                    bResult = _processTXTAnswer((stcMDNS_RRAnswerTXT*)pRRAnswer);
                }
                // 3. level answers
#ifdef MDNS_IP4_SUPPORT
                // A -> IP4Address
                else if (AnswerType_A == pRRAnswer->answerType())
                {
                    // eg. esp8266.local A xxxx xx 192.168.2.120
                    bResult = _processAAnswer((stcMDNS_RRAnswerA*)pRRAnswer);
                }
#endif
#ifdef MDNS_IP6_SUPPORT
                // AAAA -> IP6Address
                else if (AnswerType_AAAA == pRRAnswer->answerType())
                {
                    // eg. esp8266.local AAAA xxxx xx 09cf::0c
                    bResult = _processAAAAAnswer((stcMDNS_RRAnswerAAAA*)pRRAnswer);
                }
#endif

                // Finally check for probing conflicts
                // Host domain
                if ((ProbingStatus_InProgress == m_HostProbeInformation.m_ProbingStatus) &&
                        ((AnswerType_A == pRRAnswer->answerType()) ||
                         (AnswerType_AAAA == pRRAnswer->answerType())))
                {

                    stcMDNS_RRDomain    hostDomain;
                    if ((_buildDomainForHost(m_pcHostname, hostDomain)) &&
                            (pRRAnswer->m_Header.m_Domain == hostDomain))
                    {

                        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAnswers: Probing CONFLICT found with: %s.local\n"), m_pcHostname););
                        _cancelProbingForHost();
                    }
                }
                // Service domains
                for (stcMDNSService* pService = m_pServices; pService; pService = pService->m_pNext)
                {
                    if ((ProbingStatus_InProgress == pService->m_ProbeInformation.m_ProbingStatus) &&
                            ((AnswerType_TXT == pRRAnswer->answerType()) ||
                             (AnswerType_SRV == pRRAnswer->answerType())))
                    {

                        stcMDNS_RRDomain    serviceDomain;
                        if ((_buildDomainForService(*pService, true, serviceDomain)) &&
                                (pRRAnswer->m_Header.m_Domain == serviceDomain))
                        {

                            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAnswers: Probing CONFLICT found with: %s.%s.%s\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol););
                            _cancelProbingForService(*pService);
                        }
                    }
                }

                pRRAnswer = pRRAnswer->m_pNext; // Next collected answer
            }   // while (answers)
        } while ((bFoundNewKeyAnswer) &&
                 (bResult));
    }   // else: No answers provided
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAnswers: FAILED!\n"));
    });
    return bResult;
}

/*
    MDNSResponder::_processPTRAnswer
*/
bool MDNSResponder::_processPTRAnswer(const MDNSResponder::stcMDNS_RRAnswerPTR* p_pPTRAnswer,
                                      bool& p_rbFoundNewKeyAnswer)
{

    bool    bResult = false;

    if ((bResult = (0 != p_pPTRAnswer)))
    {
        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processPTRAnswer: Processing PTR answers...\n")););
        // eg. _http._tcp.local PTR xxxx xx MyESP._http._tcp.local
        // Check pending service queries for eg. '_http._tcp'

        stcMDNSServiceQuery*    pServiceQuery = _findNextServiceQueryByServiceType(p_pPTRAnswer->m_Header.m_Domain, 0);
        while (pServiceQuery)
        {
            if (pServiceQuery->m_bAwaitingAnswers)
            {
                // Find answer for service domain (eg. MyESP._http._tcp.local)
                stcMDNSServiceQuery::stcAnswer* pSQAnswer = pServiceQuery->findAnswerForServiceDomain(p_pPTRAnswer->m_PTRDomain);
                if (pSQAnswer)      // existing answer
                {
                    if (p_pPTRAnswer->m_u32TTL)     // Received update message
                    {
                        pSQAnswer->m_TTLServiceDomain.set(p_pPTRAnswer->m_u32TTL);    // Update TTL tag
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processPTRAnswer: Updated TTL(%d) for "), (int)p_pPTRAnswer->m_u32TTL);
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR("\n"));
                        );
                    }
                    else                            // received goodbye-message
                    {
                        pSQAnswer->m_TTLServiceDomain.prepareDeletion();    // Prepare answer deletion according to RFC 6762, 10.1
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processPTRAnswer: 'Goodbye' received for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR("\n"));
                        );
                    }
                }
                else if ((p_pPTRAnswer->m_u32TTL) &&                                // Not just a goodbye-message
                         ((pSQAnswer = new stcMDNSServiceQuery::stcAnswer)))        // Not yet included -> add answer
                {
                    pSQAnswer->m_ServiceDomain = p_pPTRAnswer->m_PTRDomain;
                    pSQAnswer->m_u32ContentFlags |= ServiceQueryAnswerType_ServiceDomain;
                    pSQAnswer->m_TTLServiceDomain.set(p_pPTRAnswer->m_u32TTL);
                    pSQAnswer->releaseServiceDomain();

                    bResult = pServiceQuery->addAnswer(pSQAnswer);
                    p_rbFoundNewKeyAnswer = true;
                    if (pServiceQuery->m_fnCallback)
                    {
                        MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                        pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_ServiceDomain), true);
                    }
                }
            }
            pServiceQuery = _findNextServiceQueryByServiceType(p_pPTRAnswer->m_Header.m_Domain, pServiceQuery);
        }
    }   // else: No p_pPTRAnswer
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processPTRAnswer: FAILED!\n"));
    });
    return bResult;
}

/*
    MDNSResponder::_processSRVAnswer
*/
bool MDNSResponder::_processSRVAnswer(const MDNSResponder::stcMDNS_RRAnswerSRV* p_pSRVAnswer,
                                      bool& p_rbFoundNewKeyAnswer)
{

    bool    bResult = false;

    if ((bResult = (0 != p_pSRVAnswer)))
    {
        // eg. MyESP._http._tcp.local SRV xxxx xx yy zz 5000 esp8266.local

        stcMDNSServiceQuery*    pServiceQuery = m_pServiceQueries;
        while (pServiceQuery)
        {
            stcMDNSServiceQuery::stcAnswer* pSQAnswer = pServiceQuery->findAnswerForServiceDomain(p_pSRVAnswer->m_Header.m_Domain);
            if (pSQAnswer)      // Answer for this service domain (eg. MyESP._http._tcp.local) available
            {
                if (p_pSRVAnswer->m_u32TTL)     // First or update message (TTL != 0)
                {
                    pSQAnswer->m_TTLHostDomainAndPort.set(p_pSRVAnswer->m_u32TTL);    // Update TTL tag
                    DEBUG_EX_INFO(
                        DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processSRVAnswer: Updated TTL(%d) for "), (int)p_pSRVAnswer->m_u32TTL);
                        _printRRDomain(pSQAnswer->m_ServiceDomain);
                        DEBUG_OUTPUT.printf_P(PSTR(" host domain and port\n"));
                    );
                    // Host domain & Port
                    if ((pSQAnswer->m_HostDomain != p_pSRVAnswer->m_SRVDomain) ||
                            (pSQAnswer->m_u16Port != p_pSRVAnswer->m_u16Port))
                    {

                        pSQAnswer->m_HostDomain = p_pSRVAnswer->m_SRVDomain;
                        pSQAnswer->releaseHostDomain();
                        pSQAnswer->m_u16Port = p_pSRVAnswer->m_u16Port;
                        pSQAnswer->m_u32ContentFlags |= ServiceQueryAnswerType_HostDomainAndPort;

                        p_rbFoundNewKeyAnswer = true;
                        if (pServiceQuery->m_fnCallback)
                        {
                            MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                            pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_HostDomainAndPort), true);
                        }
                    }
                }
                else                        // Goodby message
                {
                    pSQAnswer->m_TTLHostDomainAndPort.prepareDeletion();    // Prepare answer deletion according to RFC 6762, 10.1
                    DEBUG_EX_INFO(
                        DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processSRVAnswer: 'Goodbye' received for "));
                        _printRRDomain(pSQAnswer->m_ServiceDomain);
                        DEBUG_OUTPUT.printf_P(PSTR(" host domain and port\n"));
                    );
                }
            }
            pServiceQuery = pServiceQuery->m_pNext;
        }   // while(service query)
    }   // else: No p_pSRVAnswer
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processSRVAnswer: FAILED!\n"));
    });
    return bResult;
}

/*
    MDNSResponder::_processTXTAnswer
*/
bool MDNSResponder::_processTXTAnswer(const MDNSResponder::stcMDNS_RRAnswerTXT* p_pTXTAnswer)
{

    bool    bResult = false;

    if ((bResult = (0 != p_pTXTAnswer)))
    {
        // eg. MyESP._http._tcp.local TXT xxxx xx c#=1

        stcMDNSServiceQuery*    pServiceQuery = m_pServiceQueries;
        while (pServiceQuery)
        {
            stcMDNSServiceQuery::stcAnswer* pSQAnswer = pServiceQuery->findAnswerForServiceDomain(p_pTXTAnswer->m_Header.m_Domain);
            if (pSQAnswer)      // Answer for this service domain (eg. MyESP._http._tcp.local) available
            {
                if (p_pTXTAnswer->m_u32TTL)     // First or update message
                {
                    pSQAnswer->m_TTLTxts.set(p_pTXTAnswer->m_u32TTL); // Update TTL tag
                    DEBUG_EX_INFO(
                        DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processTXTAnswer: Updated TTL(%d) for "), (int)p_pTXTAnswer->m_u32TTL);
                        _printRRDomain(pSQAnswer->m_ServiceDomain);
                        DEBUG_OUTPUT.printf_P(PSTR(" TXTs\n"));
                    );
                    if (!pSQAnswer->m_Txts.compare(p_pTXTAnswer->m_Txts))
                    {
                        pSQAnswer->m_Txts = p_pTXTAnswer->m_Txts;
                        pSQAnswer->m_u32ContentFlags |= ServiceQueryAnswerType_Txts;
                        pSQAnswer->releaseTxts();

                        if (pServiceQuery->m_fnCallback)
                        {
                            MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                            pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_Txts), true);
                        }
                    }
                }
                else                        // Goodby message
                {
                    pSQAnswer->m_TTLTxts.prepareDeletion(); // Prepare answer deletion according to RFC 6762, 10.1
                    DEBUG_EX_INFO(
                        DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processTXTAnswer: 'Goodbye' received for "));
                        _printRRDomain(pSQAnswer->m_ServiceDomain);
                        DEBUG_OUTPUT.printf_P(PSTR(" TXTs\n"));
                    );
                }
            }
            pServiceQuery = pServiceQuery->m_pNext;
        }   // while(service query)
    }   // else: No p_pTXTAnswer
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processTXTAnswer: FAILED!\n"));
    });
    return bResult;
}

#ifdef MDNS_IP4_SUPPORT
/*
    MDNSResponder::_processAAnswer
*/
bool MDNSResponder::_processAAnswer(const MDNSResponder::stcMDNS_RRAnswerA* p_pAAnswer)
{

    bool    bResult = false;

    if ((bResult = (0 != p_pAAnswer)))
    {
        // eg. esp8266.local A xxxx xx 192.168.2.120

        stcMDNSServiceQuery*    pServiceQuery = m_pServiceQueries;
        while (pServiceQuery)
        {
            stcMDNSServiceQuery::stcAnswer* pSQAnswer = pServiceQuery->findAnswerForHostDomain(p_pAAnswer->m_Header.m_Domain);
            if (pSQAnswer)      // Answer for this host domain (eg. esp8266.local) available
            {
                stcMDNSServiceQuery::stcAnswer::stcIP4Address*  pIP4Address = pSQAnswer->findIP4Address(p_pAAnswer->m_IPAddress);
                if (pIP4Address)
                {
                    // Already known IP4 address
                    if (p_pAAnswer->m_u32TTL)   // Valid TTL -> Update answers TTL
                    {
                        pIP4Address->m_TTL.set(p_pAAnswer->m_u32TTL);
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: Updated TTL(%d) for "), (int)p_pAAnswer->m_u32TTL);
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" IP4Address (%s)\n"), pIP4Address->m_IPAddress.toString().c_str());
                        );
                    }
                    else                        // 'Goodbye' message for known IP4 address
                    {
                        pIP4Address->m_TTL.prepareDeletion();   // Prepare answer deletion according to RFC 6762, 10.1
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: 'Goodbye' received for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" IP4 address (%s)\n"), pIP4Address->m_IPAddress.toString().c_str());
                        );
                    }
                }
                else
                {
                    // Until now unknown IP4 address -> Add (if the message isn't just a 'Goodbye' note)
                    if (p_pAAnswer->m_u32TTL)   // NOT just a 'Goodbye' message
                    {
                        pIP4Address = new stcMDNSServiceQuery::stcAnswer::stcIP4Address(p_pAAnswer->m_IPAddress, p_pAAnswer->m_u32TTL);
                        if ((pIP4Address) &&
                                (pSQAnswer->addIP4Address(pIP4Address)))
                        {

                            pSQAnswer->m_u32ContentFlags |= ServiceQueryAnswerType_IP4Address;
                            if (pServiceQuery->m_fnCallback)
                            {
                                MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                                pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_IP4Address), true);
                            }
                        }
                        else
                        {
                            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: FAILED to add IP4 address (%s)!\n"), p_pAAnswer->m_IPAddress.toString().c_str()););
                        }
                    }
                }
            }
            pServiceQuery = pServiceQuery->m_pNext;
        }   // while(service query)
    }   // else: No p_pAAnswer
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: FAILED!\n"));
    });
    return bResult;
}
#endif

#ifdef MDNS_IP6_SUPPORT
/*
    MDNSResponder::_processAAAAAnswer
*/
bool MDNSResponder::_processAAAAAnswer(const MDNSResponder::stcMDNS_RRAnswerAAAA* p_pAAAAAnswer)
{

    bool    bResult = false;

    if ((bResult = (0 != p_pAAAAAnswer)))
    {
        // eg. esp8266.local AAAA xxxx xx 0bf3::0c

        stcMDNSServiceQuery*    pServiceQuery = m_pServiceQueries;
        while (pServiceQuery)
        {
            stcMDNSServiceQuery::stcAnswer* pSQAnswer = pServiceQuery->findAnswerForHostDomain(p_pAAAAAnswer->m_Header.m_Domain);
            if (pSQAnswer)      // Answer for this host domain (eg. esp8266.local) available
            {
                stcIP6Address*  pIP6Address = pSQAnswer->findIP6Address(p_pAAAAAnswer->m_IPAddress);
                if (pIP6Address)
                {
                    // Already known IP6 address
                    if (p_pAAAAAnswer->m_u32TTL)   // Valid TTL -> Update answers TTL
                    {
                        pIP6Address->m_TTL.set(p_pAAAAAnswer->m_u32TTL);
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: Updated TTL(%lu) for "), p_pAAAAAnswer->m_u32TTL);
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" IP6 address (%s)\n"), pIP6Address->m_IPAddress.toString().c_str());
                        );
                    }
                    else                        // 'Goodbye' message for known IP6 address
                    {
                        pIP6Address->m_TTL.prepareDeletion();   // Prepare answer deletion according to RFC 6762, 10.1
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: 'Goodbye' received for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" IP6 address (%s)\n"), pIP6Address->m_IPAddress.toString().c_str());
                        );
                    }
                }
                else
                {
                    // Until now unknown IP6 address -> Add (if the message isn't just a 'Goodbye' note)
                    if (p_pAAAAAnswer->m_u32TTL)   // NOT just a 'Goodbye' message
                    {
                        pIP6Address = new stcIP6Address(p_pAAAAAnswer->m_IPAddress, p_pAAAAAnswer->m_u32TTL);
                        if ((pIP6Address) &&
                                (pSQAnswer->addIP6Address(pIP6Address)))
                        {

                            pSQAnswer->m_u32ContentFlags |= ServiceQueryAnswerType_IP6Address;

                            if (pServiceQuery->m_fnCallback)
                            {
                                pServiceQuery->m_fnCallback(this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer), ServiceQueryAnswerType_IP6Address, true, pServiceQuery->m_pUserdata);
                            }
                        }
                        else
                        {
                            DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _processAAnswer: FAILED to add IP6 address (%s)!\n"), p_pAAAAAnswer->m_IPAddress.toString().c_str()););
                        }
                    }
                }
            }
            pServiceQuery = pServiceQuery->m_pNext;
        }   // while(service query)
    }   // else: No p_pAAAAAnswer

    return bResult;
}
#endif


/*
    PROBING
*/

/*
    MDNSResponder::_updateProbeStatus

    Manages the (outgoing) probing process.
    - If probing has not been started yet (ProbingStatus_NotStarted), the initial delay (see RFC 6762) is determined and
     the process is started
    - After timeout (of initial or subsequential delay) a probe message is send out for three times. If the message has
     already been sent out three times, the probing has been successful and is finished.

    Conflict management is handled in '_parseResponse ff.'
    Tiebraking is handled in 'parseQuery ff.'
*/
bool MDNSResponder::_updateProbeStatus(void)
{

    bool    bResult = true;

    //
    // Probe host domain
    if ((ProbingStatus_ReadyToStart == m_HostProbeInformation.m_ProbingStatus) &&                   // Ready to get started AND
            //TODO: Fix the following to allow Ethernet shield or other interfaces
            (_getResponseMulticastInterface() != IPAddress()))                // Has IP address
    {
        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Starting host probing...\n")););

        // First probe delay SHOULD be random 0-250 ms
        m_HostProbeInformation.m_Timeout.reset(rand() % MDNS_PROBE_DELAY);
        m_HostProbeInformation.m_ProbingStatus = ProbingStatus_InProgress;
    }
    else if ((ProbingStatus_InProgress == m_HostProbeInformation.m_ProbingStatus) &&                // Probing AND
             (m_HostProbeInformation.m_Timeout.expired()))                                          // Time for next probe
    {

        if (MDNS_PROBE_COUNT > m_HostProbeInformation.m_u8SentCount)                                // Send next probe
        {
            if ((bResult = _sendHostProbe()))
            {
                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Did sent host probe\n\n")););
                m_HostProbeInformation.m_Timeout.reset(MDNS_PROBE_DELAY);
                ++m_HostProbeInformation.m_u8SentCount;
            }
        }
        else                                                                                        // Probing finished
        {
            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Done host probing.\n")););
            m_HostProbeInformation.m_ProbingStatus = ProbingStatus_Done;
            m_HostProbeInformation.m_Timeout.resetToNeverExpires();
            if (m_HostProbeInformation.m_fnHostProbeResultCallback)
            {
                m_HostProbeInformation.m_fnHostProbeResultCallback(m_pcHostname, true);
            }

            // Prepare to announce host
            m_HostProbeInformation.m_u8SentCount = 0;
            m_HostProbeInformation.m_Timeout.reset(MDNS_ANNOUNCE_DELAY);
            DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Prepared host announcing.\n\n")););
        }
    }   // else: Probing already finished OR waiting for next time slot
    else if ((ProbingStatus_Done == m_HostProbeInformation.m_ProbingStatus) &&
             (m_HostProbeInformation.m_Timeout.expired()))
    {

        if ((bResult = _announce(true, false)))     // Don't announce services here
        {
            ++m_HostProbeInformation.m_u8SentCount;

            if (MDNS_ANNOUNCE_COUNT > m_HostProbeInformation.m_u8SentCount)
            {
                m_HostProbeInformation.m_Timeout.reset(MDNS_ANNOUNCE_DELAY);
                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Announcing host (%d).\n\n"), m_HostProbeInformation.m_u8SentCount););
            }
            else
            {
                m_HostProbeInformation.m_Timeout.resetToNeverExpires();
                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Done host announcing.\n\n")););
            }
        }
    }

    //
    // Probe services
    for (stcMDNSService* pService = m_pServices; ((bResult) && (pService)); pService = pService->m_pNext)
    {
        if (ProbingStatus_ReadyToStart == pService->m_ProbeInformation.m_ProbingStatus)         // Ready to get started
        {

            pService->m_ProbeInformation.m_Timeout.reset(MDNS_PROBE_DELAY);                     // More or equal than first probe for host domain
            pService->m_ProbeInformation.m_ProbingStatus = ProbingStatus_InProgress;
        }
        else if ((ProbingStatus_InProgress == pService->m_ProbeInformation.m_ProbingStatus) &&  // Probing AND
                 (pService->m_ProbeInformation.m_Timeout.expired()))               // Time for next probe
        {

            if (MDNS_PROBE_COUNT > pService->m_ProbeInformation.m_u8SentCount)                  // Send next probe
            {
                if ((bResult = _sendServiceProbe(*pService)))
                {
                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Did sent service probe (%u)\n\n"), (pService->m_ProbeInformation.m_u8SentCount + 1)););
                    pService->m_ProbeInformation.m_Timeout.reset(MDNS_PROBE_DELAY);
                    ++pService->m_ProbeInformation.m_u8SentCount;
                }
            }
            else                                                                                        // Probing finished
            {
                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Done service probing %s.%s.%s\n\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol););
                pService->m_ProbeInformation.m_ProbingStatus = ProbingStatus_Done;
                pService->m_ProbeInformation.m_Timeout.resetToNeverExpires();
                if (pService->m_ProbeInformation.m_fnServiceProbeResultCallback)
                {
                    pService->m_ProbeInformation.m_fnServiceProbeResultCallback(pService->m_pcName, pService, true);
                }
                // Prepare to announce service
                pService->m_ProbeInformation.m_u8SentCount = 0;
                pService->m_ProbeInformation.m_Timeout.reset(MDNS_ANNOUNCE_DELAY);
                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Prepared service announcing.\n\n")););
            }
        }   // else: Probing already finished OR waiting for next time slot
        else if ((ProbingStatus_Done == pService->m_ProbeInformation.m_ProbingStatus) &&
                 (pService->m_ProbeInformation.m_Timeout.expired()))
        {

            if ((bResult = _announceService(*pService)))     // Announce service
            {
                ++pService->m_ProbeInformation.m_u8SentCount;

                if (MDNS_ANNOUNCE_COUNT > pService->m_ProbeInformation.m_u8SentCount)
                {
                    pService->m_ProbeInformation.m_Timeout.reset(MDNS_ANNOUNCE_DELAY);
                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Announcing service %s.%s.%s (%d)\n\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol, pService->m_ProbeInformation.m_u8SentCount););
                }
                else
                {
                    pService->m_ProbeInformation.m_Timeout.resetToNeverExpires();
                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: Done service announcing for %s.%s.%s\n\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol););
                }
            }
        }
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _updateProbeStatus: FAILED!\n\n"));
    });
    return bResult;
}

/*
    MDNSResponder::_resetProbeStatus

    Resets the probe status.
    If 'p_bRestart' is set, the status is set to ProbingStatus_NotStarted. Consequently,
    when running 'updateProbeStatus' (which is done in every '_update' loop), the probing
    process is restarted.
*/
bool MDNSResponder::_resetProbeStatus(bool p_bRestart /*= true*/)
{

    m_HostProbeInformation.clear(false);
    m_HostProbeInformation.m_ProbingStatus = (p_bRestart ? ProbingStatus_ReadyToStart : ProbingStatus_Done);

    for (stcMDNSService* pService = m_pServices; pService; pService = pService->m_pNext)
    {
        pService->m_ProbeInformation.clear(false);
        pService->m_ProbeInformation.m_ProbingStatus = (p_bRestart ? ProbingStatus_ReadyToStart : ProbingStatus_Done);
    }
    return true;
}

/*
    MDNSResponder::_hasProbesWaitingForAnswers
*/
bool MDNSResponder::_hasProbesWaitingForAnswers(void) const
{

    bool    bResult = ((ProbingStatus_InProgress == m_HostProbeInformation.m_ProbingStatus) &&      // Probing
                       (0 < m_HostProbeInformation.m_u8SentCount));                                 // And really probing

    for (stcMDNSService* pService = m_pServices; ((!bResult) && (pService)); pService = pService->m_pNext)
    {
        bResult = ((ProbingStatus_InProgress == pService->m_ProbeInformation.m_ProbingStatus) &&    // Probing
                   (0 < pService->m_ProbeInformation.m_u8SentCount));                               // And really probing
    }
    return bResult;
}

/*
    MDNSResponder::_sendHostProbe

    Asks (probes) in the local network for the planned host domain
    - (eg. esp8266.local)

    To allow 'tiebreaking' (see '_parseQuery'), the answers for these questions are delivered in
    the 'knwon answers' section of the query.
    Host domain:
    - A/AAAA (eg. esp8266.esp -> 192.168.2.120)
*/
bool MDNSResponder::_sendHostProbe(void)
{
    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendHostProbe (%s, %lu)\n"), m_pcHostname, millis()););

    bool    bResult = true;

    // Requests for host domain
    stcMDNSSendParameter    sendParameter;
    sendParameter.m_bCacheFlush = false;    // RFC 6762 10.2

    sendParameter.m_pQuestions = new stcMDNS_RRQuestion;
    if (((bResult = (0 != sendParameter.m_pQuestions))) &&
            ((bResult = _buildDomainForHost(m_pcHostname, sendParameter.m_pQuestions->m_Header.m_Domain))))
    {

        //sendParameter.m_pQuestions->m_bUnicast = true;
        sendParameter.m_pQuestions->m_Header.m_Attributes.m_u16Type = DNS_RRTYPE_ANY;
        sendParameter.m_pQuestions->m_Header.m_Attributes.m_u16Class = (0x8000 | DNS_RRCLASS_IN);   // Unicast & INternet

        // Add known answers
#ifdef MDNS_IP4_SUPPORT
        sendParameter.m_u8HostReplyMask |= ContentFlag_A;                                   // Add A answer
#endif
#ifdef MDNS_IP6_SUPPORT
        sendParameter.m_u8HostReplyMask |= ContentFlag_AAAA;                                // Add AAAA answer
#endif
    }
    else
    {
        DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendHostProbe: FAILED to create host question!\n")););
        if (sendParameter.m_pQuestions)
        {
            delete sendParameter.m_pQuestions;
            sendParameter.m_pQuestions = 0;
        }
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendHostProbe: FAILED!\n"));
    });
    return ((bResult) &&
            (_sendMDNSMessage(sendParameter)));
}

/*
    MDNSResponder::_sendServiceProbe

    Asks (probes) in the local network for the planned service instance domain
    - (eg. MyESP._http._tcp.local).

    To allow 'tiebreaking' (see '_parseQuery'), the answers for these questions are delivered in
    the 'knwon answers' section of the query.
    Service domain:
    - SRV (eg. MyESP._http._tcp.local -> 5000 esp8266.local)
    - PTR NAME (eg. _http._tcp.local -> MyESP._http._tcp.local) (TODO: Check if needed, maybe TXT is better)
*/
bool MDNSResponder::_sendServiceProbe(stcMDNSService& p_rService)
{
    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendServiceProbe (%s.%s.%s, %lu)\n"), (p_rService.m_pcName ? : m_pcHostname), p_rService.m_pcService, p_rService.m_pcProtocol, millis()););

    bool    bResult = true;

    // Requests for service instance domain
    stcMDNSSendParameter    sendParameter;
    sendParameter.m_bCacheFlush = false;    // RFC 6762 10.2

    sendParameter.m_pQuestions = new stcMDNS_RRQuestion;
    if (((bResult = (0 != sendParameter.m_pQuestions))) &&
            ((bResult = _buildDomainForService(p_rService, true, sendParameter.m_pQuestions->m_Header.m_Domain))))
    {

        sendParameter.m_pQuestions->m_bUnicast = true;
        sendParameter.m_pQuestions->m_Header.m_Attributes.m_u16Type = DNS_RRTYPE_ANY;
        sendParameter.m_pQuestions->m_Header.m_Attributes.m_u16Class = (0x8000 | DNS_RRCLASS_IN);   // Unicast & INternet

        // Add known answers
        p_rService.m_u8ReplyMask = (ContentFlag_SRV | ContentFlag_PTR_NAME);                // Add SRV and PTR NAME answers
    }
    else
    {
        DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendServiceProbe: FAILED to create service question!\n")););
        if (sendParameter.m_pQuestions)
        {
            delete sendParameter.m_pQuestions;
            sendParameter.m_pQuestions = 0;
        }
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendServiceProbe: FAILED!\n"));
    });
    return ((bResult) &&
            (_sendMDNSMessage(sendParameter)));
}

/*
    MDNSResponder::_cancelProbingForHost
*/
bool MDNSResponder::_cancelProbingForHost(void)
{

    bool    bResult = false;

    m_HostProbeInformation.clear(false);
    // Send host notification
    if (m_HostProbeInformation.m_fnHostProbeResultCallback)
    {
        m_HostProbeInformation.m_fnHostProbeResultCallback(m_pcHostname, false);

        bResult = true;
    }

    for (stcMDNSService* pService = m_pServices; ((!bResult) && (pService)); pService = pService->m_pNext)
    {
        bResult = _cancelProbingForService(*pService);
    }
    return bResult;
}

/*
    MDNSResponder::_cancelProbingForService
*/
bool MDNSResponder::_cancelProbingForService(stcMDNSService& p_rService)
{

    bool    bResult = false;

    p_rService.m_ProbeInformation.clear(false);
    // Send notification
    if (p_rService.m_ProbeInformation.m_fnServiceProbeResultCallback)
    {
        p_rService.m_ProbeInformation.m_fnServiceProbeResultCallback(p_rService.m_pcName, &p_rService, false);
        bResult = true;
    }
    return bResult;
}



/**
    ANNOUNCING
*/

/*
    MDNSResponder::_announce

    Announces the host domain:
    - A/AAAA (eg. esp8266.local -> 192.168.2.120)
    - PTR (eg. 192.168.2.120.in-addr.arpa -> esp8266.local)

    and all presented services:
    - PTR_TYPE (_services._dns-sd._udp.local -> _http._tcp.local)
    - PTR_NAME (eg. _http._tcp.local -> MyESP8266._http._tcp.local)
    - SRV (eg. MyESP8266._http._tcp.local -> 5000 esp8266.local)
    - TXT (eg. MyESP8266._http._tcp.local -> c#=1)

    Goodbye (Un-Announcing) for the host domain and all services is also handled here.
    Goodbye messages are created by setting the TTL for the answer to 0, this happens
    inside the '_writeXXXAnswer' procs via 'sendParameter.m_bUnannounce = true'
*/
bool MDNSResponder::_announce(bool p_bAnnounce,
                              bool p_bIncludeServices)
{

    bool    bResult = false;

    stcMDNSSendParameter    sendParameter;
    if (ProbingStatus_Done == m_HostProbeInformation.m_ProbingStatus)
    {

        bResult = true;

        sendParameter.m_bResponse = true;           // Announces are 'Unsolicited authorative responses'
        sendParameter.m_bAuthorative = true;
        sendParameter.m_bUnannounce = !p_bAnnounce; // When unannouncing, the TTL is set to '0' while creating the answers

        // Announce host
        sendParameter.m_u8HostReplyMask = 0;
#ifdef MDNS_IP4_SUPPORT
        sendParameter.m_u8HostReplyMask |= ContentFlag_A;                   // A answer
        sendParameter.m_u8HostReplyMask |= ContentFlag_PTR_IP4;             // PTR_IP4 answer
#endif
#ifdef MDNS_IP6_SUPPORT
        sendParameter.m_u8HostReplyMask |= ContentFlag_AAAA;                // AAAA answer
        sendParameter.m_u8HostReplyMask |= ContentFlag_PTR_IP6;             // PTR_IP6 answer
#endif

        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _announce: Announcing host %s (content 0x%X)\n"), m_pcHostname, sendParameter.m_u8HostReplyMask););

        if (p_bIncludeServices)
        {
            // Announce services (service type, name, SRV (location) and TXTs)
            for (stcMDNSService* pService = m_pServices; ((bResult) && (pService)); pService = pService->m_pNext)
            {
                if (ProbingStatus_Done == pService->m_ProbeInformation.m_ProbingStatus)
                {
                    pService->m_u8ReplyMask = (ContentFlag_PTR_TYPE | ContentFlag_PTR_NAME | ContentFlag_SRV | ContentFlag_TXT);

                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _announce: Announcing service %s.%s.%s (content %u)\n"), (pService->m_pcName ? : m_pcHostname), pService->m_pcService, pService->m_pcProtocol, pService->m_u8ReplyMask););
                }
            }
        }
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _announce: FAILED!\n"));
    });
    return ((bResult) &&
            (_sendMDNSMessage(sendParameter)));
}

/*
    MDNSResponder::_announceService
*/
bool MDNSResponder::_announceService(stcMDNSService& p_rService,
                                     bool p_bAnnounce /*= true*/)
{

    bool    bResult = false;

    stcMDNSSendParameter    sendParameter;
    if (ProbingStatus_Done == p_rService.m_ProbeInformation.m_ProbingStatus)
    {

        sendParameter.m_bResponse = true;           // Announces are 'Unsolicited authorative responses'
        sendParameter.m_bAuthorative = true;
        sendParameter.m_bUnannounce = !p_bAnnounce; // When unannouncing, the TTL is set to '0' while creating the answers

        // DON'T announce host
        sendParameter.m_u8HostReplyMask = 0;

        // Announce services (service type, name, SRV (location) and TXTs)
        p_rService.m_u8ReplyMask = (ContentFlag_PTR_TYPE | ContentFlag_PTR_NAME | ContentFlag_SRV | ContentFlag_TXT);
        DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _announceService: Announcing service %s.%s.%s (content 0x%X)\n"), (p_rService.m_pcName ? : m_pcHostname), p_rService.m_pcService, p_rService.m_pcProtocol, p_rService.m_u8ReplyMask););

        bResult = true;
    }
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _announceService: FAILED!\n"));
    });
    return ((bResult) &&
            (_sendMDNSMessage(sendParameter)));
}


/**
    SERVICE QUERY CACHE
*/

/*
    MDNSResponder::_hasServiceQueriesWaitingForAnswers
*/
bool MDNSResponder::_hasServiceQueriesWaitingForAnswers(void) const
{

    bool    bOpenQueries = false;

    for (stcMDNSServiceQuery* pServiceQuery = m_pServiceQueries; pServiceQuery; pServiceQuery = pServiceQuery->m_pNext)
    {
        if (pServiceQuery->m_bAwaitingAnswers)
        {
            bOpenQueries = true;
            break;
        }
    }
    return bOpenQueries;
}

/*
    MDNSResponder::_checkServiceQueryCache

    For any 'living' service query (m_bAwaitingAnswers == true) all available answers (their components)
    are checked for topicality based on the stored reception time and the answers TTL.
    When the components TTL is outlasted by more than 80%, a new question is generated, to get updated information.
    When no update arrived (in time), the component is removed from the answer (cache).

*/
bool MDNSResponder::_checkServiceQueryCache(void)
{

    bool        bResult = true;

    DEBUG_EX_INFO(
        bool    printedInfo = false;
    );
    for (stcMDNSServiceQuery* pServiceQuery = m_pServiceQueries; ((bResult) && (pServiceQuery)); pServiceQuery = pServiceQuery->m_pNext)
    {

        //
        // Resend dynamic service queries, if not already done often enough
        if ((!pServiceQuery->m_bLegacyQuery) &&
                (MDNS_DYNAMIC_QUERY_RESEND_COUNT > pServiceQuery->m_u8SentCount) &&
                (pServiceQuery->m_ResendTimeout.expired()))
        {

            if ((bResult = _sendMDNSServiceQuery(*pServiceQuery)))
            {
                ++pServiceQuery->m_u8SentCount;
                pServiceQuery->m_ResendTimeout.reset((MDNS_DYNAMIC_QUERY_RESEND_COUNT > pServiceQuery->m_u8SentCount)
                                                     ? (MDNS_DYNAMIC_QUERY_RESEND_DELAY * (pServiceQuery->m_u8SentCount - 1))
                                                     : esp8266::polledTimeout::oneShotMs::neverExpires);
            }
            DEBUG_EX_INFO(
                DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: %s to resend service query!"), (bResult ? "Succeeded" : "FAILED"));
                printedInfo = true;
            );
        }

        //
        // Schedule updates for cached answers
        if (pServiceQuery->m_bAwaitingAnswers)
        {
            stcMDNSServiceQuery::stcAnswer* pSQAnswer = pServiceQuery->m_pAnswers;
            while ((bResult) &&
                    (pSQAnswer))
            {
                stcMDNSServiceQuery::stcAnswer* pNextSQAnswer = pSQAnswer->m_pNext;

                // 1. level answer
                if ((bResult) &&
                        (pSQAnswer->m_TTLServiceDomain.flagged()))
                {

                    if (!pSQAnswer->m_TTLServiceDomain.finalTimeoutLevel())
                    {

                        bResult = ((_sendMDNSServiceQuery(*pServiceQuery)) &&
                                   (pSQAnswer->m_TTLServiceDomain.restart()));
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: PTR update scheduled for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" %s\n"), (bResult ? "OK" : "FAILURE"));
                            printedInfo = true;
                        );
                    }
                    else
                    {
                        // Timed out! -> Delete
                        if (pServiceQuery->m_fnCallback)
                        {
                            MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                            pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_ServiceDomain), false);
                        }
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: Will remove PTR answer for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR("\n"));
                            printedInfo = true;
                        );

                        bResult = pServiceQuery->removeAnswer(pSQAnswer);
                        pSQAnswer = 0;
                        continue;   // Don't use this answer anymore
                    }
                }   // ServiceDomain flagged

                // 2. level answers
                // HostDomain & Port (from SRV)
                if ((bResult) &&
                        (pSQAnswer->m_TTLHostDomainAndPort.flagged()))
                {

                    if (!pSQAnswer->m_TTLHostDomainAndPort.finalTimeoutLevel())
                    {

                        bResult = ((_sendMDNSQuery(pSQAnswer->m_ServiceDomain, DNS_RRTYPE_SRV)) &&
                                   (pSQAnswer->m_TTLHostDomainAndPort.restart()));
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: SRV update scheduled for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" host domain and port %s\n"), (bResult ? "OK" : "FAILURE"));
                            printedInfo = true;
                        );
                    }
                    else
                    {
                        // Timed out! -> Delete
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: Will remove SRV answer for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" host domain and port\n"));
                            printedInfo = true;
                        );
                        // Delete
                        pSQAnswer->m_HostDomain.clear();
                        pSQAnswer->releaseHostDomain();
                        pSQAnswer->m_u16Port = 0;
                        pSQAnswer->m_TTLHostDomainAndPort.set(0);
                        uint32_t    u32ContentFlags = ServiceQueryAnswerType_HostDomainAndPort;
                        // As the host domain is the base for the IP4- and IP6Address, remove these too
#ifdef MDNS_IP4_SUPPORT
                        pSQAnswer->releaseIP4Addresses();
                        u32ContentFlags |= ServiceQueryAnswerType_IP4Address;
#endif
#ifdef MDNS_IP6_SUPPORT
                        pSQAnswer->releaseIP6Addresses();
                        u32ContentFlags |= ServiceQueryAnswerType_IP6Address;
#endif

                        // Remove content flags for deleted answer parts
                        pSQAnswer->m_u32ContentFlags &= ~u32ContentFlags;
                        if (pServiceQuery->m_fnCallback)
                        {
                            MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                            pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(u32ContentFlags), false);
                        }
                    }
                }   // HostDomainAndPort flagged

                // Txts (from TXT)
                if ((bResult) &&
                        (pSQAnswer->m_TTLTxts.flagged()))
                {

                    if (!pSQAnswer->m_TTLTxts.finalTimeoutLevel())
                    {

                        bResult = ((_sendMDNSQuery(pSQAnswer->m_ServiceDomain, DNS_RRTYPE_TXT)) &&
                                   (pSQAnswer->m_TTLTxts.restart()));
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: TXT update scheduled for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" TXTs %s\n"), (bResult ? "OK" : "FAILURE"));
                            printedInfo = true;
                        );
                    }
                    else
                    {
                        // Timed out! -> Delete
                        DEBUG_EX_INFO(
                            DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: Will remove TXT answer for "));
                            _printRRDomain(pSQAnswer->m_ServiceDomain);
                            DEBUG_OUTPUT.printf_P(PSTR(" TXTs\n"));
                            printedInfo = true;
                        );
                        // Delete
                        pSQAnswer->m_Txts.clear();
                        pSQAnswer->m_TTLTxts.set(0);

                        // Remove content flags for deleted answer parts
                        pSQAnswer->m_u32ContentFlags &= ~ServiceQueryAnswerType_Txts;

                        if (pServiceQuery->m_fnCallback)
                        {
                            MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                            pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_Txts), false);
                        }
                    }
                }   // TXTs flagged

                // 3. level answers
#ifdef MDNS_IP4_SUPPORT
                // IP4Address (from A)
                stcMDNSServiceQuery::stcAnswer::stcIP4Address*  pIP4Address = pSQAnswer->m_pIP4Addresses;
                bool                                            bAUpdateQuerySent = false;
                while ((pIP4Address) &&
                        (bResult))
                {

                    stcMDNSServiceQuery::stcAnswer::stcIP4Address*  pNextIP4Address = pIP4Address->m_pNext; // Get 'next' early, as 'current' may be deleted at the end...

                    if (pIP4Address->m_TTL.flagged())
                    {

                        if (!pIP4Address->m_TTL.finalTimeoutLevel())    // Needs update
                        {

                            if ((bAUpdateQuerySent) ||
                                    ((bResult = _sendMDNSQuery(pSQAnswer->m_HostDomain, DNS_RRTYPE_A))))
                            {

                                pIP4Address->m_TTL.restart();
                                bAUpdateQuerySent = true;

                                DEBUG_EX_INFO(
                                    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: IP4 update scheduled for "));
                                    _printRRDomain(pSQAnswer->m_ServiceDomain);
                                    DEBUG_OUTPUT.printf_P(PSTR(" IP4 address (%s)\n"), (pIP4Address->m_IPAddress.toString().c_str()));
                                    printedInfo = true;
                                );
                            }
                        }
                        else
                        {
                            // Timed out! -> Delete
                            DEBUG_EX_INFO(
                                DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: Will remove IP4 answer for "));
                                _printRRDomain(pSQAnswer->m_ServiceDomain);
                                DEBUG_OUTPUT.printf_P(PSTR(" IP4 address\n"));
                                printedInfo = true;
                            );
                            pSQAnswer->removeIP4Address(pIP4Address);
                            if (!pSQAnswer->m_pIP4Addresses)    // NO IP4 address left -> remove content flag
                            {
                                pSQAnswer->m_u32ContentFlags &= ~ServiceQueryAnswerType_IP4Address;
                            }
                            // Notify client
                            if (pServiceQuery->m_fnCallback)
                            {
                                MDNSServiceInfo serviceInfo(*this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer));
                                pServiceQuery->m_fnCallback(serviceInfo, static_cast<AnswerType>(ServiceQueryAnswerType_IP4Address), false);
                            }
                        }
                    }   // IP4 flagged

                    pIP4Address = pNextIP4Address;  // Next
                }   // while
#endif
#ifdef MDNS_IP6_SUPPORT
                // IP6Address (from AAAA)
                stcMDNSServiceQuery::stcAnswer::stcIP6Address*  pIP6Address = pSQAnswer->m_pIP6Addresses;
                bool                                            bAAAAUpdateQuerySent = false;
                while ((pIP6Address) &&
                        (bResult))
                {

                    stcMDNSServiceQuery::stcAnswer::stcIP6Address*  pNextIP6Address = pIP6Address->m_pNext; // Get 'next' early, as 'current' may be deleted at the end...

                    if (pIP6Address->m_TTL.flagged())
                    {

                        if (!pIP6Address->m_TTL.finalTimeoutLevel())    // Needs update
                        {

                            if ((bAAAAUpdateQuerySent) ||
                                    ((bResult = _sendMDNSQuery(pSQAnswer->m_HostDomain, DNS_RRTYPE_AAAA))))
                            {

                                pIP6Address->m_TTL.restart();
                                bAAAAUpdateQuerySent = true;

                                DEBUG_EX_INFO(
                                    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: IP6 update scheduled for "));
                                    _printRRDomain(pSQAnswer->m_ServiceDomain);
                                    DEBUG_OUTPUT.printf_P(PSTR(" IP6 address (%s)\n"), (pIP6Address->m_IPAddress.toString().c_str()));
                                    printedInfo = true;
                                );
                            }
                        }
                        else
                        {
                            // Timed out! -> Delete
                            DEBUG_EX_INFO(
                                DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: Will remove answer for "));
                                _printRRDomain(pSQAnswer->m_ServiceDomain);
                                DEBUG_OUTPUT.printf_P(PSTR(" IP6Address\n"));
                                printedInfo = true;
                            );
                            pSQAnswer->removeIP6Address(pIP6Address);
                            if (!pSQAnswer->m_pIP6Addresses)    // NO IP6 address left -> remove content flag
                            {
                                pSQAnswer->m_u32ContentFlags &= ~ServiceQueryAnswerType_IP6Address;
                            }
                            // Notify client
                            if (pServiceQuery->m_fnCallback)
                            {
                                pServiceQuery->m_fnCallback(this, (hMDNSServiceQuery)pServiceQuery, pServiceQuery->indexOfAnswer(pSQAnswer), ServiceQueryAnswerType_IP6Address, false, pServiceQuery->m_pUserdata);
                            }
                        }
                    }   // IP6 flagged

                    pIP6Address = pNextIP6Address;  // Next
                }   // while
#endif
                pSQAnswer = pNextSQAnswer;
            }
        }
    }
    DEBUG_EX_INFO(
        if (printedInfo)
{
    DEBUG_OUTPUT.printf_P(PSTR("\n"));
    }
    );
    DEBUG_EX_ERR(if (!bResult)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _checkServiceQueryCache: FAILED!\n"));
    });
    return bResult;
}


/*
    MDNSResponder::_replyMaskForHost

    Determines the relavant host answers for the given question.
    - A question for the hostname (eg. esp8266.local) will result in an A/AAAA (eg. 192.168.2.129) reply.
    - A question for the reverse IP address (eg. 192-168.2.120.inarpa.arpa) will result in an PTR_IP4 (eg. esp8266.local) reply.

    In addition, a full name match (question domain == host domain) is marked.
*/
uint8_t MDNSResponder::_replyMaskForHost(const MDNSResponder::stcMDNS_RRHeader& p_RRHeader,
        bool* p_pbFullNameMatch /*= 0*/) const
{
    //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _replyMaskForHost\n")););

    uint8_t u8ReplyMask = 0;
    (p_pbFullNameMatch ? *p_pbFullNameMatch = false : 0);

    if ((DNS_RRCLASS_IN == p_RRHeader.m_Attributes.m_u16Class) ||
            (DNS_RRCLASS_ANY == p_RRHeader.m_Attributes.m_u16Class))
    {

        if ((DNS_RRTYPE_PTR == p_RRHeader.m_Attributes.m_u16Type) ||
                (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type))
        {
            // PTR request
#ifdef MDNS_IP4_SUPPORT
            stcMDNS_RRDomain    reverseIP4Domain;
            if ((_buildDomainForReverseIP4(_getResponseMulticastInterface(), reverseIP4Domain)) &&
                    (p_RRHeader.m_Domain == reverseIP4Domain))
            {
                // Reverse domain match
                u8ReplyMask |= ContentFlag_PTR_IP4;
            }
#endif
#ifdef MDNS_IP6_SUPPORT
            // TODO
#endif
        }   // Address qeuest

        stcMDNS_RRDomain    hostDomain;
        if ((_buildDomainForHost(m_pcHostname, hostDomain)) &&
                (p_RRHeader.m_Domain == hostDomain))    // Host domain match
        {

            (p_pbFullNameMatch ? (*p_pbFullNameMatch = true) : (0));

#ifdef MDNS_IP4_SUPPORT
            if ((DNS_RRTYPE_A == p_RRHeader.m_Attributes.m_u16Type) ||
                    (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type))
            {
                // IP4 address request
                u8ReplyMask |= ContentFlag_A;
            }
#endif
#ifdef MDNS_IP6_SUPPORT
            if ((DNS_RRTYPE_AAAA == p_RRHeader.m_Attributes.m_u16Type) ||
                    (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type))
            {
                // IP6 address request
                u8ReplyMask |= ContentFlag_AAAA;
            }
#endif
        }
    }
    else
    {
        //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _replyMaskForHost: INVALID RR-class (0x%04X)!\n"), p_RRHeader.m_Attributes.m_u16Class););
    }
    DEBUG_EX_INFO(if (u8ReplyMask)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _replyMaskForHost: 0x%X\n"), u8ReplyMask);
    });
    return u8ReplyMask;
}

/*
    MDNSResponder::_replyMaskForService

    Determines the relevant service answers for the given question
    - A PTR dns-sd service enum question (_services.dns-sd._udp.local) will result into an PTR_TYPE (eg. _http._tcp.local) answer
    - A PTR service type question (eg. _http._tcp.local) will result into an PTR_NAME (eg. MyESP._http._tcp.local) answer
    - A PTR service name question (eg. MyESP._http._tcp.local) will result into an PTR_NAME (eg. MyESP._http._tcp.local) answer
    - A SRV service name question (eg. MyESP._http._tcp.local) will result into an SRV (eg. 5000 MyESP.local) answer
    - A TXT service name question (eg. MyESP._http._tcp.local) will result into an TXT (eg. c#=1) answer

    In addition, a full name match (question domain == service instance domain) is marked.
*/
uint8_t MDNSResponder::_replyMaskForService(const MDNSResponder::stcMDNS_RRHeader& p_RRHeader,
        const MDNSResponder::stcMDNSService& p_Service,
        bool* p_pbFullNameMatch /*= 0*/) const
{

    uint8_t u8ReplyMask = 0;
    (p_pbFullNameMatch ? *p_pbFullNameMatch = false : 0);

    if ((DNS_RRCLASS_IN == p_RRHeader.m_Attributes.m_u16Class) ||
            (DNS_RRCLASS_ANY == p_RRHeader.m_Attributes.m_u16Class))
    {

        stcMDNS_RRDomain    DNSSDDomain;
        if ((_buildDomainForDNSSD(DNSSDDomain)) &&                          // _services._dns-sd._udp.local
                (p_RRHeader.m_Domain == DNSSDDomain) &&
                ((DNS_RRTYPE_PTR == p_RRHeader.m_Attributes.m_u16Type) ||
                 (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type)))
        {
            // Common service info requested
            u8ReplyMask |= ContentFlag_PTR_TYPE;
        }

        stcMDNS_RRDomain    serviceDomain;
        if ((_buildDomainForService(p_Service, false, serviceDomain)) &&    // eg. _http._tcp.local
                (p_RRHeader.m_Domain == serviceDomain) &&
                ((DNS_RRTYPE_PTR == p_RRHeader.m_Attributes.m_u16Type) ||
                 (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type)))
        {
            // Special service info requested
            u8ReplyMask |= ContentFlag_PTR_NAME;
        }

        if ((_buildDomainForService(p_Service, true, serviceDomain)) &&     // eg. MyESP._http._tcp.local
                (p_RRHeader.m_Domain == serviceDomain))
        {

            (p_pbFullNameMatch ? (*p_pbFullNameMatch = true) : (0));

            if ((DNS_RRTYPE_SRV == p_RRHeader.m_Attributes.m_u16Type) ||
                    (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type))
            {
                // Instance info SRV requested
                u8ReplyMask |= ContentFlag_SRV;
            }
            if ((DNS_RRTYPE_TXT == p_RRHeader.m_Attributes.m_u16Type) ||
                    (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type))
            {
                // Instance info TXT requested
                u8ReplyMask |= ContentFlag_TXT;
            }
        }
    }
    else
    {
        //DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _replyMaskForService: INVALID RR-class (0x%04X)!\n"), p_RRHeader.m_Attributes.m_u16Class););
    }
    DEBUG_EX_INFO(if (u8ReplyMask)
{
    DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _replyMaskForService(%s.%s.%s): 0x%X\n"), p_Service.m_pcName, p_Service.m_pcService, p_Service.m_pcProtocol, u8ReplyMask);
    });
    return u8ReplyMask;
}

} // namespace MDNSImplementation

} // namespace esp8266
