1 /*
2  * Bittorrent Client using Qt and libtorrent.
3  * Copyright (C) 2019  Mike Tzou (Chocobo1)
4  * Copyright (C) 2015  Vladimir Golovnev <glassez@yandex.ru>
5  * Copyright (C) 2010  Christophe Dumez <chris@qbittorrent.org>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version 2
10  * of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
20  *
21  * In addition, as a special exception, the copyright holders give permission to
22  * link this program with the OpenSSL project's "OpenSSL" library (or with
23  * modified versions of it that use the same license as the "OpenSSL" library),
24  * and distribute the linked executables. You must obey the GNU General Public
25  * License in all respects for all of the code used other than "OpenSSL".  If you
26  * modify file(s), you may extend this exception to your version of the file(s),
27  * but you are not obligated to do so. If you do not wish to do so, delete this
28  * exception statement from your version.
29  */
30 
31 #pragma once
32 
33 #include <string>
34 
35 #include <libtorrent/entry.hpp>
36 
37 #include <QHash>
38 #include <QObject>
39 #include <QSet>
40 
41 #include "base/bittorrent/infohash.h"
42 #include "base/http/irequesthandler.h"
43 #include "base/http/responsebuilder.h"
44 
45 namespace Http
46 {
47     class Server;
48 }
49 
50 namespace BitTorrent
51 {
52     struct Peer
53     {
54         QByteArray peerId;
55         ushort port = 0;  // self-claimed by peer, might not be the same as socket port
56         bool isSeeder = false;
57 
58         // caching precomputed values
59         lt::entry::string_type address;
60         lt::entry::string_type endpoint;
61 
62         QByteArray uniqueID() const;
63     };
64 
65     bool operator==(const Peer &left, const Peer &right);
66     bool operator!=(const Peer &left, const Peer &right);
67     uint qHash(const Peer &key, uint seed);
68 
69     // *Basic* Bittorrent tracker implementation
70     // [BEP-3] The BitTorrent Protocol Specification
71     // also see: https://wiki.theory.org/index.php/BitTorrentSpecification#Tracker_HTTP.2FHTTPS_Protocol
72     class Tracker final : public QObject, public Http::IRequestHandler, private Http::ResponseBuilder
73     {
74         Q_OBJECT
Q_DISABLE_COPY(Tracker)75         Q_DISABLE_COPY(Tracker)
76 
77         struct TrackerAnnounceRequest;
78 
79         struct TorrentStats
80         {
81             qint64 seeders = 0;
82             QSet<Peer> peers;
83 
84             void setPeer(const Peer &peer);
85             bool removePeer(const Peer &peer);
86         };
87 
88     public:
89         explicit Tracker(QObject *parent = nullptr);
90 
91         bool start();
92 
93     private:
94         Http::Response processRequest(const Http::Request &request, const Http::Environment &env) override;
95         void processAnnounceRequest();
96 
97         void registerPeer(const TrackerAnnounceRequest &announceReq);
98         void unregisterPeer(const TrackerAnnounceRequest &announceReq);
99         void prepareAnnounceResponse(const TrackerAnnounceRequest &announceReq);
100 
101         Http::Server *m_server;
102         Http::Request m_request;
103         Http::Environment m_env;
104 
105         QHash<TorrentID, TorrentStats> m_torrents;
106     };
107 }
108