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#pragma once
#include "dolog.hh"
#include "dnsdist-tcp.hh"
#include "dnsdist-tcp-downstream.hh"
struct TCPCrossProtocolResponse;
class TCPClientThreadData
{
public:
TCPClientThreadData():
localRespRuleActions(g_respruleactions.getLocal()), localCacheInsertedRespRuleActions(g_cacheInsertedRespRuleActions.getLocal()), mplexer(std::unique_ptr<FDMultiplexer>(FDMultiplexer::getMultiplexerSilent()))
{
}
LocalHolders holders;
LocalStateHolder<vector<DNSDistResponseRuleAction>> localRespRuleActions;
LocalStateHolder<vector<DNSDistResponseRuleAction>> localCacheInsertedRespRuleActions;
std::unique_ptr<FDMultiplexer> mplexer{nullptr};
pdns::channel::Receiver<ConnectionInfo> queryReceiver;
pdns::channel::Receiver<CrossProtocolQuery> crossProtocolQueryReceiver;
pdns::channel::Receiver<TCPCrossProtocolResponse> crossProtocolResponseReceiver;
pdns::channel::Sender<TCPCrossProtocolResponse> crossProtocolResponseSender;
};
class IncomingTCPConnectionState : public TCPQuerySender, public std::enable_shared_from_this<IncomingTCPConnectionState>
{
public:
enum class QueryProcessingResult : uint8_t { Forwarded, TooSmall, InvalidHeaders, Dropped, SelfAnswered, NoBackend, Asynchronous };
enum class ProxyProtocolResult : uint8_t { Reading, Done, Error };
IncomingTCPConnectionState(ConnectionInfo&& ci, TCPClientThreadData& threadData, const struct timeval& now): d_buffer(sizeof(uint16_t)), d_ci(std::move(ci)), d_handler(d_ci.fd, timeval{g_tcpRecvTimeout,0}, d_ci.cs->tlsFrontend ? d_ci.cs->tlsFrontend->getContext() : (d_ci.cs->dohFrontend ? d_ci.cs->dohFrontend->d_tlsContext.getContext() : nullptr), now.tv_sec), d_connectionStartTime(now), d_ioState(make_unique<IOStateHandler>(*threadData.mplexer, d_ci.fd)), d_threadData(threadData), d_creatorThreadID(std::this_thread::get_id())
{
d_origDest.reset();
d_origDest.sin4.sin_family = d_ci.remote.sin4.sin_family;
socklen_t socklen = d_origDest.getSocklen();
if (getsockname(d_ci.fd, reinterpret_cast<sockaddr*>(&d_origDest), &socklen)) {
d_origDest = d_ci.cs->local;
}
/* belongs to the handler now */
d_ci.fd = -1;
d_proxiedDestination = d_origDest;
d_proxiedRemote = d_ci.remote;
/* we manage the release of the downstream connection ourselves */
d_releaseConnection = false;
}
IncomingTCPConnectionState(const IncomingTCPConnectionState& rhs) = delete;
IncomingTCPConnectionState& operator=(const IncomingTCPConnectionState& rhs) = delete;
virtual ~IncomingTCPConnectionState();
void resetForNewQuery();
boost::optional<struct timeval> getClientReadTTD(struct timeval now) const
{
if (g_maxTCPConnectionDuration == 0 && g_tcpRecvTimeout == 0) {
return boost::none;
}
if (g_maxTCPConnectionDuration > 0) {
auto elapsed = now.tv_sec - d_connectionStartTime.tv_sec;
if (elapsed < 0 || (static_cast<size_t>(elapsed) >= g_maxTCPConnectionDuration)) {
return now;
}
auto remaining = g_maxTCPConnectionDuration - elapsed;
if (g_tcpRecvTimeout == 0 || remaining <= static_cast<size_t>(g_tcpRecvTimeout)) {
now.tv_sec += remaining;
return now;
}
}
now.tv_sec += g_tcpRecvTimeout;
return now;
}
boost::optional<struct timeval> getClientWriteTTD(const struct timeval& now) const
{
if (g_maxTCPConnectionDuration == 0 && g_tcpSendTimeout == 0) {
return boost::none;
}
struct timeval res = now;
if (g_maxTCPConnectionDuration > 0) {
auto elapsed = res.tv_sec - d_connectionStartTime.tv_sec;
if (elapsed < 0 || static_cast<size_t>(elapsed) >= g_maxTCPConnectionDuration) {
return res;
}
auto remaining = g_maxTCPConnectionDuration - elapsed;
if (g_tcpSendTimeout == 0 || remaining <= static_cast<size_t>(g_tcpSendTimeout)) {
res.tv_sec += remaining;
return res;
}
}
res.tv_sec += g_tcpSendTimeout;
return res;
}
bool maxConnectionDurationReached(unsigned int maxConnectionDuration, const struct timeval& now)
{
if (maxConnectionDuration) {
time_t curtime = now.tv_sec;
unsigned int elapsed = 0;
if (curtime > d_connectionStartTime.tv_sec) { // To prevent issues when time goes backward
elapsed = curtime - d_connectionStartTime.tv_sec;
}
if (elapsed >= maxConnectionDuration) {
return true;
}
}
return false;
}
std::shared_ptr<TCPConnectionToBackend> getOwnedDownstreamConnection(const std::shared_ptr<DownstreamState>& backend, const std::unique_ptr<std::vector<ProxyProtocolValue>>& tlvs);
std::shared_ptr<TCPConnectionToBackend> getDownstreamConnection(std::shared_ptr<DownstreamState>& backend, const std::unique_ptr<std::vector<ProxyProtocolValue>>& tlvs, const struct timeval& now);
void registerOwnedDownstreamConnection(std::shared_ptr<TCPConnectionToBackend>& conn);
static size_t clearAllDownstreamConnections();
static void handleIOCallback(int desc, FDMultiplexer::funcparam_t& param);
static void handleAsyncReady(int desc, FDMultiplexer::funcparam_t& param);
static void updateIO(std::shared_ptr<IncomingTCPConnectionState>& state, IOState newState, const struct timeval& now);
static void queueResponse(std::shared_ptr<IncomingTCPConnectionState>& state, const struct timeval& now, TCPResponse&& response, bool fromBackend);
static void handleTimeout(std::shared_ptr<IncomingTCPConnectionState>& state, bool write);
virtual void handleIO();
QueryProcessingResult handleQuery(PacketBuffer&& query, const struct timeval& now, std::optional<int32_t> streamID);
virtual void handleResponse(const struct timeval& now, TCPResponse&& response) override;
virtual void notifyIOError(const struct timeval& now, TCPResponse&& response) override;
void handleXFRResponse(const struct timeval& now, TCPResponse&& response) override;
virtual IOState sendResponse(const struct timeval& now, TCPResponse&& response);
void handleResponseSent(TCPResponse& currentResponse);
virtual IOState handleHandshake(const struct timeval& now);
void handleHandshakeDone(const struct timeval& now);
ProxyProtocolResult handleProxyProtocolPayload();
void handleCrossProtocolResponse(const struct timeval& now, TCPResponse&& response);
void terminateClientConnection();
bool canAcceptNewQueries(const struct timeval& now);
bool active() const override
{
return d_ioState != nullptr;
}
bool isProxyPayloadOutsideTLS() const
{
if (!d_ci.cs->hasTLS()) {
return false;
}
return d_ci.cs->getTLSFrontend().d_proxyProtocolOutsideTLS;
}
virtual bool forwardViaUDPFirst() const
{
return false;
}
virtual std::unique_ptr<DOHUnitInterface> getDOHUnit(uint32_t streamID)
{
throw std::runtime_error("Getting a DOHUnit state from a generic TCP/DoT connection is not supported");
}
virtual void restoreDOHUnit(std::unique_ptr<DOHUnitInterface>&&)
{
throw std::runtime_error("Restoring a DOHUnit state to a generic TCP/DoT connection is not supported");
}
std::unique_ptr<CrossProtocolQuery> getCrossProtocolQuery(PacketBuffer&& query, InternalQueryState&& state, const std::shared_ptr<DownstreamState>& backend);
std::string toString() const
{
ostringstream o;
o << "Incoming TCP connection from "<<d_ci.remote.toStringWithPort()<<" over FD "<<d_handler.getDescriptor()<<", state is "<<(int)d_state<<", io state is "<<(d_ioState ? d_ioState->getState() : "empty")<<", queries count is "<<d_queriesCount<<", current queries count is "<<d_currentQueriesCount<<", "<<d_queuedResponses.size()<<" queued responses, "<<d_ownedConnectionsToBackend.size()<<" owned connections to a backend";
return o.str();
}
dnsdist::Protocol getProtocol() const;
IOState handleIncomingQueryReceived(const struct timeval& now);
void handleExceptionDuringIO(const std::exception& exp);
bool readIncomingQuery(const timeval& now, IOState& iostate);
enum class State : uint8_t { starting, doingHandshake, readingProxyProtocolHeader, waitingForQuery, readingQuerySize, readingQuery, sendingResponse, idle /* in case of XFR, we stop processing queries */ };
TCPResponse d_currentResponse;
std::map<std::shared_ptr<DownstreamState>, std::deque<std::shared_ptr<TCPConnectionToBackend>>> d_ownedConnectionsToBackend;
std::deque<TCPResponse> d_queuedResponses;
PacketBuffer d_buffer;
ConnectionInfo d_ci;
ComboAddress d_origDest;
ComboAddress d_proxiedRemote;
ComboAddress d_proxiedDestination;
TCPIOHandler d_handler;
struct timeval d_connectionStartTime;
struct timeval d_handshakeDoneTime;
struct timeval d_firstQuerySizeReadTime;
struct timeval d_querySizeReadTime;
struct timeval d_queryReadTime;
std::unique_ptr<IOStateHandler> d_ioState{nullptr};
std::unique_ptr<std::vector<ProxyProtocolValue>> d_proxyProtocolValues{nullptr};
TCPClientThreadData& d_threadData;
size_t d_currentPos{0};
size_t d_proxyProtocolNeed{0};
size_t d_queriesCount{0};
size_t d_currentQueriesCount{0};
std::thread::id d_creatorThreadID;
uint16_t d_querySize{0};
State d_state{State::starting};
bool d_isXFR{false};
bool d_proxyProtocolPayloadHasTLV{false};
bool d_lastIOBlocked{false};
bool d_hadErrors{false};
};
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