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/*
* 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 "protozero.hh"
#ifndef DISABLE_PROTOBUF
#include "dnsparser.hh"
void pdns::ProtoZero::Message::encodeComboAddress(const protozero::pbf_tag_type type, const ComboAddress& address)
{
if (address.sin4.sin_family == AF_INET) {
d_message.add_bytes(type, reinterpret_cast<const char*>(&address.sin4.sin_addr.s_addr), sizeof(address.sin4.sin_addr.s_addr)); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast): it's the API
}
else if (address.sin4.sin_family == AF_INET6) {
d_message.add_bytes(type, reinterpret_cast<const char*>(&address.sin6.sin6_addr.s6_addr), sizeof(address.sin6.sin6_addr.s6_addr)); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast): it's the API
}
}
void pdns::ProtoZero::Message::encodeNetmask(const protozero::pbf_tag_type type, const Netmask& subnet, uint8_t mask)
{
if (!subnet.empty()) {
ComboAddress address(subnet.getNetwork());
address.truncate(mask);
if (address.sin4.sin_family == AF_INET) {
d_message.add_bytes(type, reinterpret_cast<const char*>(&address.sin4.sin_addr.s_addr), sizeof(address.sin4.sin_addr.s_addr)); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast): it's the API
}
else if (address.sin4.sin_family == AF_INET6) {
d_message.add_bytes(type, reinterpret_cast<const char*>(&address.sin6.sin6_addr.s6_addr), sizeof(address.sin6.sin6_addr.s6_addr)); // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast): it's the API
}
}
}
void pdns::ProtoZero::Message::encodeDNSName(protozero::pbf_writer& pbf, std::string& buffer, const protozero::pbf_tag_type type, const DNSName& name)
{
// this will append the tag, mark the current position then reserve enough place to write the size
protozero::pbf_writer pbf_name{pbf, type};
// we append the name to the buffer
name.toString(buffer);
// leaving the block will cause the sub writer to compute how much was written based on the new size and update the size accordingly
}
void pdns::ProtoZero::Message::setRequest(const boost::uuids::uuid& uniqueId, const ComboAddress& requestor, const ComboAddress& local, const DNSName& qname, uint16_t qtype, uint16_t qclass, uint16_t qid, pdns::ProtoZero::Message::TransportProtocol proto, size_t len)
{
setMessageIdentity(uniqueId);
setSocketFamily(requestor.sin4.sin_family);
setSocketProtocol(proto);
setFrom(requestor);
setTo(local);
setInBytes(len);
setTime();
setId(qid);
setQuestion(qname, qtype, qclass);
setFromPort(requestor.getPort());
setToPort(local.getPort());
}
void pdns::ProtoZero::Message::setResponse(const DNSName& qname, uint16_t qtype, uint16_t qclass)
{
setType(pdns::ProtoZero::Message::MessageType::DNSResponseType);
setQuestion(qname, qtype, qclass);
}
void pdns::ProtoZero::Message::addRRsFromPacket(const char* packet, const size_t len, bool includeCNAME)
{
if (len < sizeof(struct dnsheader)) {
return;
}
const dnsheader_aligned header(packet);
if (ntohs(header->ancount) == 0) {
return;
}
if (ntohs(header->qdcount) == 0) {
return;
}
PacketReader packetReader(std::string_view(packet, len));
size_t idx = 0;
DNSName rrname;
uint16_t qdcount = ntohs(header->qdcount);
uint16_t ancount = ntohs(header->ancount);
uint16_t rrtype{};
uint16_t rrclass{};
string blob;
dnsrecordheader recordHeader{};
rrname = packetReader.getName();
rrtype = packetReader.get16BitInt();
rrclass = packetReader.get16BitInt();
(void)rrtype;
(void)rrclass;
/* consume remaining qd if any */
if (qdcount > 1) {
for (idx = 1; idx < qdcount; idx++) {
rrname = packetReader.getName();
rrtype = packetReader.get16BitInt();
rrclass = packetReader.get16BitInt();
(void)rrtype;
(void)rrclass;
}
}
/* parse AN */
for (idx = 0; idx < ancount; idx++) {
rrname = packetReader.getName();
packetReader.getDnsrecordheader(recordHeader);
if (recordHeader.d_type == QType::A || recordHeader.d_type == QType::AAAA) {
packetReader.xfrBlob(blob);
addRR(rrname, recordHeader.d_type, recordHeader.d_class, recordHeader.d_ttl, blob);
}
else if (recordHeader.d_type == QType::CNAME && includeCNAME) {
protozero::pbf_writer pbf_rr{d_response, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::ResponseField::rrs)};
encodeDNSName(pbf_rr, d_buffer, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::name), rrname);
pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::type), recordHeader.d_type);
pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::class_), recordHeader.d_class);
pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::ttl), recordHeader.d_ttl);
DNSName target;
packetReader.xfrName(target, true);
encodeDNSName(pbf_rr, d_buffer, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::rdata), target);
}
else {
packetReader.xfrBlob(blob);
}
}
}
void pdns::ProtoZero::Message::addRR(const DNSName& name, uint16_t uType, uint16_t uClass, uint32_t uTTL, const std::string& blob)
{
protozero::pbf_writer pbf_rr{d_response, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::ResponseField::rrs)};
encodeDNSName(pbf_rr, d_buffer, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::name), name);
pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::type), uType);
pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::class_), uClass);
pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::ttl), uTTL);
pbf_rr.add_string(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::rdata), blob);
}
#endif /* DISABLE_PROTOBUF */
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