/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "config.h"
#include "dnsdist.hh"
#include "dnsdist-protobuf.hh"
#include "protozero.hh"

DNSDistProtoBufMessage::DNSDistProtoBufMessage(const DNSQuestion& dq): d_dq(dq), d_type(pdns::ProtoZero::Message::MessageType::DNSQueryType)
{
}

DNSDistProtoBufMessage::DNSDistProtoBufMessage(const DNSResponse& dr, bool includeCNAME): d_dq(dr), d_dr(&dr), d_type(pdns::ProtoZero::Message::MessageType::DNSResponseType), d_includeCNAME(includeCNAME)
{
}

void DNSDistProtoBufMessage::setServerIdentity(const std::string& serverId)
{
  d_serverIdentity = serverId;
}

void DNSDistProtoBufMessage::setRequestor(const ComboAddress& requestor)
{
  d_requestor = requestor;
}

void DNSDistProtoBufMessage::setResponder(const ComboAddress& responder)
{
  d_responder = responder;
}

void DNSDistProtoBufMessage::setRequestorPort(uint16_t port)
{
  if (d_requestor) {
    d_requestor->setPort(port);
  }
}

void DNSDistProtoBufMessage::setResponderPort(uint16_t port)
{
  if (d_responder) {
    d_responder->setPort(port);
  }
}

void DNSDistProtoBufMessage::setResponseCode(uint8_t rcode)
{
  d_rcode = rcode;
}

void DNSDistProtoBufMessage::setType(pdns::ProtoZero::Message::MessageType type)
{
  d_type = type;
}

void DNSDistProtoBufMessage::setBytes(size_t bytes)
{
  d_bytes = bytes;
}

void DNSDistProtoBufMessage::setTime(time_t sec, uint32_t usec)
{
  d_time = std::pair(sec, usec);
}

void DNSDistProtoBufMessage::setQueryTime(time_t sec, uint32_t usec)
{
  d_queryTime = std::pair(sec, usec);
}

void DNSDistProtoBufMessage::setQuestion(const DNSName& name, uint16_t qtype, uint16_t qclass)
{
  d_question = DNSDistProtoBufMessage::PBQuestion(name, qtype, qclass);
}

void DNSDistProtoBufMessage::setEDNSSubnet(const Netmask& nm)
{
  d_ednsSubnet = nm;
}

void DNSDistProtoBufMessage::addTag(const std::string& strValue)
{
  d_additionalTags.push_back(strValue);
}

void DNSDistProtoBufMessage::addRR(DNSName&& qname, uint16_t uType, uint16_t uClass, uint32_t uTTL, const std::string& strBlob)
{
  d_additionalRRs.push_back({std::move(qname), strBlob, uTTL, uType, uClass});
}

void DNSDistProtoBufMessage::serialize(std::string& data) const
{
  if ((data.capacity() - data.size()) < 128) {
    data.reserve(data.size() + 128);
  }
  pdns::ProtoZero::Message m{data};

  m.setType(d_type);

  if (d_time) {
    m.setTime(d_time->first, d_time->second);
  }
  else {
    struct timespec ts;
    gettime(&ts, true);
    m.setTime(ts.tv_sec, ts.tv_nsec / 1000);
  }

  const auto distProto = d_dq.getProtocol();
  pdns::ProtoZero::Message::TransportProtocol protocol = pdns::ProtoZero::Message::TransportProtocol::UDP;

  if (distProto == dnsdist::Protocol::DoTCP) {
    protocol = pdns::ProtoZero::Message::TransportProtocol::TCP;
  }
  else if (distProto == dnsdist::Protocol::DoT) {
    protocol = pdns::ProtoZero::Message::TransportProtocol::DoT;
  }
  else if (distProto == dnsdist::Protocol::DoH) {
    protocol = pdns::ProtoZero::Message::TransportProtocol::DoH;
  }
  else if (distProto == dnsdist::Protocol::DNSCryptUDP) {
    protocol = pdns::ProtoZero::Message::TransportProtocol::DNSCryptUDP;
  }
  else if (distProto == dnsdist::Protocol::DNSCryptTCP) {
    protocol = pdns::ProtoZero::Message::TransportProtocol::DNSCryptTCP;
  }

  m.setRequest(d_dq.uniqueId ? *d_dq.uniqueId : getUniqueID(), d_requestor ? *d_requestor : *d_dq.remote, d_responder ? *d_responder : *d_dq.local, d_question ? d_question->d_name : *d_dq.qname, d_question ? d_question->d_type : d_dq.qtype, d_question ? d_question->d_class : d_dq.qclass, d_dq.getHeader()->id, protocol, d_bytes ? *d_bytes : d_dq.getData().size());

  if (d_serverIdentity) {
    m.setServerIdentity(*d_serverIdentity);
  }
  else if (d_ServerIdentityRef != nullptr) {
    m.setServerIdentity(*d_ServerIdentityRef);
  }

  if (d_ednsSubnet) {
    m.setEDNSSubnet(*d_ednsSubnet, 128);
  }

  m.startResponse();
  if (d_queryTime) {
    m.setQueryTime(d_queryTime->first, d_queryTime->second);
  }
  else {
    m.setQueryTime(d_dq.queryTime->tv_sec, d_dq.queryTime->tv_nsec / 1000);
  }

  if (d_dr != nullptr) {
    m.setResponseCode(d_rcode ? *d_rcode : d_dr->getHeader()->rcode);
    m.addRRsFromPacket(reinterpret_cast<const char*>(d_dr->getData().data()), d_dr->getData().size(), d_includeCNAME);
  }
  else {
    if (d_rcode) {
      m.setResponseCode(*d_rcode);
    }
  }

  for (const auto& rr : d_additionalRRs) {
    m.addRR(rr.d_name, rr.d_type, rr.d_class, rr.d_ttl, rr.d_data);
  }

  for (const auto& tag : d_additionalTags) {
    m.addPolicyTag(tag);
  }

  m.commitResponse();
}