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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-proxy-protocol.hh"
#include "dnsdist-metrics.hh"
#include "dolog.hh"
NetmaskGroup g_proxyProtocolACL;
size_t g_proxyProtocolMaximumSize = 512;
bool g_applyACLToProxiedClients = false;
std::string getProxyProtocolPayload(const DNSQuestion& dq)
{
return makeProxyHeader(dq.overTCP(), dq.ids.origRemote, dq.ids.origDest, dq.proxyProtocolValues ? *dq.proxyProtocolValues : std::vector<ProxyProtocolValue>());
}
bool addProxyProtocol(DNSQuestion& dq, const std::string& payload)
{
if (!dq.hasRoomFor(payload.size())) {
return false;
}
return addProxyProtocol(dq.getMutableData(), payload);
}
bool addProxyProtocol(DNSQuestion& dq, size_t* payloadSize)
{
auto payload = getProxyProtocolPayload(dq);
if (payloadSize != nullptr) {
*payloadSize = payload.size();
}
return addProxyProtocol(dq, payload);
}
bool addProxyProtocol(PacketBuffer& buffer, const std::string& payload)
{
auto previousSize = buffer.size();
if (payload.size() > (std::numeric_limits<size_t>::max() - previousSize)) {
return false;
}
buffer.insert(buffer.begin(), payload.begin(), payload.end());
return true;
}
bool addProxyProtocol(PacketBuffer& buffer, bool tcp, const ComboAddress& source, const ComboAddress& destination, const std::vector<ProxyProtocolValue>& values)
{
auto payload = makeProxyHeader(tcp, source, destination, values);
return addProxyProtocol(buffer, payload);
}
bool expectProxyProtocolFrom(const ComboAddress& remote)
{
return g_proxyProtocolACL.match(remote);
}
bool handleProxyProtocol(const ComboAddress& remote, bool isTCP, const NetmaskGroup& acl, PacketBuffer& query, ComboAddress& realRemote, ComboAddress& realDestination, std::vector<ProxyProtocolValue>& values)
{
bool tcp;
bool proxyProto;
ssize_t used = parseProxyHeader(query, proxyProto, realRemote, realDestination, tcp, values);
if (used <= 0) {
++dnsdist::metrics::g_stats.proxyProtocolInvalid;
vinfolog("Ignoring invalid proxy protocol (%d, %d) query over %s from %s", query.size(), used, (isTCP ? "TCP" : "UDP"), remote.toStringWithPort());
return false;
}
else if (static_cast<size_t>(used) > g_proxyProtocolMaximumSize) {
vinfolog("Proxy protocol header in %s packet from %s is larger than proxy-protocol-maximum-size (%d), dropping", (isTCP ? "TCP" : "UDP"), remote.toStringWithPort(), used);
++dnsdist::metrics::g_stats.proxyProtocolInvalid;
return false;
}
query.erase(query.begin(), query.begin() + used);
/* on TCP we have not read the actual query yet */
if (!isTCP && query.size() < sizeof(struct dnsheader)) {
++dnsdist::metrics::g_stats.nonCompliantQueries;
return false;
}
if (proxyProto && g_applyACLToProxiedClients) {
if (!acl.match(realRemote)) {
vinfolog("Query from %s dropped because of ACL", realRemote.toStringWithPort());
++dnsdist::metrics::g_stats.aclDrops;
return false;
}
}
return true;
}
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