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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 "dnsdist-xpf.hh"
#include "dnsdist-dnsparser.hh"
#include "dnsparser.hh"
#include "xpf.hh"
bool addXPF(DNSQuestion& dq, uint16_t optionCode)
{
std::string payload = generateXPFPayload(dq.overTCP(), dq.ids.origRemote, dq.ids.origDest);
uint8_t root = '\0';
dnsrecordheader drh;
drh.d_type = htons(optionCode);
drh.d_class = htons(QClass::IN);
drh.d_ttl = 0;
drh.d_clen = htons(payload.size());
size_t recordHeaderLen = sizeof(root) + sizeof(drh);
if (!dq.hasRoomFor(payload.size() + recordHeaderLen)) {
return false;
}
size_t xpfSize = sizeof(root) + sizeof(drh) + payload.size();
auto& data = dq.getMutableData();
uint32_t realPacketLen = getDNSPacketLength(reinterpret_cast<const char*>(data.data()), data.size());
data.resize(realPacketLen + xpfSize);
size_t pos = realPacketLen;
memcpy(reinterpret_cast<char*>(&data.at(pos)), &root, sizeof(root));
pos += sizeof(root);
memcpy(reinterpret_cast<char*>(&data.at(pos)), &drh, sizeof(drh));
pos += sizeof(drh);
memcpy(reinterpret_cast<char*>(&data.at(pos)), payload.data(), payload.size());
pos += payload.size();
(void) pos;
dnsdist::PacketMangling::editDNSHeaderFromPacket(dq.getMutableData(), [](dnsheader& header) {
header.arcount = htons(ntohs(header.arcount) + 1);
return true;
});
return true;
}
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