torcontrol.h

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// Copyright (c) 2015-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_TORCONTROL_H
#define BITCOIN_TORCONTROL_H

#include <fs.h>
#include <netaddress.h>

#include <boost/signals2/signal.hpp>

#include <event2/bufferevent.h>
#include <event2/event.h>

#include <cstdlib>
#include <deque>
#include <functional>
#include <string>
#include <vector>

class CService;

extern const std::string DEFAULT_TOR_CONTROL;
static const bool DEFAULT_LISTEN_ONION = true;

void StartTorControl(CService onion_service_target);
void InterruptTorControl();
void StopTorControl();

CService DefaultOnionServiceTarget();

class TorControlReply
{
public:
    TorControlReply() { Clear(); }

    int code;
    std::vector<std::string> lines;

    void Clear()
    {
        code = 0;
        lines.clear();
    }
};

class TorControlConnection
{
public:
    typedef std::function<void(TorControlConnection&)> ConnectionCB;
    typedef std::function<void(TorControlConnection &,const TorControlReply &)> ReplyHandlerCB;

    explicit TorControlConnection(struct event_base *base);
    ~TorControlConnection();

    bool Connect(const std::string& tor_control_center, const ConnectionCB& connected, const ConnectionCB& disconnected);

    void Disconnect();

    bool Command(const std::string &cmd, const ReplyHandlerCB& reply_handler);

    boost::signals2::signal<void(TorControlConnection &,const TorControlReply &)> async_handler;
private:
    std::function<void(TorControlConnection&)> connected;
    std::function<void(TorControlConnection&)> disconnected;
    struct event_base *base;
    struct bufferevent *b_conn;
    TorControlReply message;
    std::deque<ReplyHandlerCB> reply_handlers;

    static void readcb(struct bufferevent *bev, void *ctx);
    static void eventcb(struct bufferevent *bev, short what, void *ctx);
};

/****** Bitcoin specific TorController implementation ********/

class TorController
{
public:
    TorController(struct event_base* base, const std::string& tor_control_center, const CService& target);
    TorController() : conn{nullptr} {
        // Used for testing only.
    }
    ~TorController();

    fs::path GetPrivateKeyFile();

    void Reconnect();
private:
    struct event_base* base;
    const std::string m_tor_control_center;
    TorControlConnection conn;
    std::string private_key;
    std::string service_id;
    bool reconnect;
    struct event *reconnect_ev = nullptr;
    float reconnect_timeout;
    CService service;
    const CService m_target;
    std::vector<uint8_t> cookie;
    std::vector<uint8_t> clientNonce;

public:
    void add_onion_cb(TorControlConnection& conn, const TorControlReply& reply);
    void auth_cb(TorControlConnection& conn, const TorControlReply& reply);
    void authchallenge_cb(TorControlConnection& conn, const TorControlReply& reply);
    void protocolinfo_cb(TorControlConnection& conn, const TorControlReply& reply);
    void connected_cb(TorControlConnection& conn);
    void disconnected_cb(TorControlConnection& conn);

    static void reconnect_cb(evutil_socket_t fd, short what, void *arg);
};

#endif /* BITCOIN_TORCONTROL_H */