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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.
*/
#pragma once
#include <thread>
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/key_extractors.hpp>
#include "channel.hh"
#include "dnsdist-tcp.hh"
namespace dnsdist
{
class AsynchronousHolder
{
public:
AsynchronousHolder(bool failOpen = true);
~AsynchronousHolder();
void push(uint16_t asyncID, uint16_t queryID, const struct timeval& ttd, std::unique_ptr<CrossProtocolQuery>&& query);
std::unique_ptr<CrossProtocolQuery> get(uint16_t asyncID, uint16_t queryID);
bool empty();
void stop();
private:
struct TTDTag
{
};
struct IDTag
{
};
struct Entry
{
/* not used by any of the indexes, so mutable */
mutable std::unique_ptr<CrossProtocolQuery> d_query;
struct timeval d_ttd;
uint16_t d_asyncID;
uint16_t d_queryID;
};
typedef multi_index_container<
Entry,
indexed_by<
ordered_unique<tag<IDTag>,
composite_key<
Entry,
member<Entry, uint16_t, &Entry::d_queryID>,
member<Entry, uint16_t, &Entry::d_asyncID>>>,
ordered_non_unique<tag<TTDTag>,
member<Entry, struct timeval, &Entry::d_ttd>>>>
content_t;
static void pickupExpired(content_t&, const struct timeval& now, std::list<std::pair<uint16_t, std::unique_ptr<CrossProtocolQuery>>>& expiredEvents);
static struct timeval getNextTTD(const content_t&);
struct Data
{
Data(bool failOpen);
Data(const Data&) = delete;
Data(Data&&) = delete;
Data& operator=(const Data&) = delete;
Data& operator=(Data&&) = delete;
~Data() = default;
LockGuarded<content_t> d_content;
pdns::channel::Notifier d_notifier;
pdns::channel::Waiter d_waiter;
bool d_failOpen{true};
bool d_done{false};
};
std::shared_ptr<Data> d_data{nullptr};
static void mainThread(std::shared_ptr<Data> data);
static bool wait(Data& data, FDMultiplexer& mplexer, std::vector<int>& readyFDs, int atMostMs);
bool notify() const;
};
bool suspendQuery(DNSQuestion& dnsQuestion, uint16_t asyncID, uint16_t queryID, uint32_t timeoutMs);
bool suspendResponse(DNSResponse& dnsResponse, uint16_t asyncID, uint16_t queryID, uint32_t timeoutMs);
bool queueQueryResumptionEvent(std::unique_ptr<CrossProtocolQuery>&& query);
bool resumeQuery(std::unique_ptr<CrossProtocolQuery>&& query);
void handleQueuedAsynchronousEvents();
extern std::unique_ptr<AsynchronousHolder> g_asyncHolder;
}
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