torcontrol.h

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// Copyright (c) 2015-2021 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 <netaddress.h>
#include <util/fs.h>
 
#include <event2/util.h>
 
#include <cstdint>
#include <deque>
#include <functional>
#include <string>
#include <vector>
 
constexpr uint16_t DEFAULT_TOR_SOCKS_PORT{9050};
constexpr int DEFAULT_TOR_CONTROL_PORT = 9051;
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(uint16_t port);
 
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);
 
private:
    std::function<void(TorControlConnection&)> connected;
    std::function<void(TorControlConnection&)> disconnected;
    struct event_base *base;
    struct bufferevent* b_conn{nullptr};
    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 get_socks_cb(TorControlConnection& conn, const TorControlReply& reply);
    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