415 lines
12 KiB
C++
415 lines
12 KiB
C++
/*
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Copyright (c) 2003, Arvid Norberg
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the distribution.
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* Neither the name of the author nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TORRENT_POLICY_HPP_INCLUDED
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#define TORRENT_POLICY_HPP_INCLUDED
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#include <algorithm>
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#include <deque>
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#include "libtorrent/peer.hpp"
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#include "libtorrent/piece_picker.hpp"
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#include "libtorrent/socket.hpp"
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#include "libtorrent/size_type.hpp"
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#include "libtorrent/invariant_check.hpp"
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#include "libtorrent/config.hpp"
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#include "libtorrent/time.hpp"
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namespace libtorrent
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{
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class torrent;
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class peer_connection;
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enum
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{
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// the limits of the download queue size
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min_request_queue = 2,
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// the amount of free upload allowed before
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// the peer is choked
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free_upload_amount = 4 * 16 * 1024
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};
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void request_a_block(torrent& t, peer_connection& c);
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class TORRENT_EXPORT policy
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{
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public:
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policy(torrent* t);
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// this is called every 10 seconds to allow
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// for peer choking management
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void pulse();
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struct peer;
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// this is called once for every peer we get from
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// the tracker, pex, lsd or dht.
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policy::peer* add_peer(const tcp::endpoint& remote, const peer_id& pid
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, int source, char flags);
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// false means duplicate connection
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bool update_peer_port(int port, policy::peer* p, int src);
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// called when an incoming connection is accepted
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// false means the connection was refused or failed
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bool new_connection(peer_connection& c, int session_time);
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// the given connection was just closed
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void connection_closed(const peer_connection& c, int session_time);
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void ban_peer(policy::peer* p);
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// the peer has got at least one interesting piece
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void peer_is_interesting(peer_connection& c);
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void ip_filter_updated();
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void set_seed(policy::peer* p, bool s);
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#ifdef TORRENT_DEBUG
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bool has_connection(const peer_connection* p);
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void check_invariant() const;
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#endif
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// intended struct layout (on 32 bit architectures)
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// offset size alignment field
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// 0 12 1 prev_amount_upload, prev_amount_download
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// 12 4 4 connection
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// 16 2 2 last_optimistically_unchoked
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// 18 2 2 last_connected
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// 20 16 1 addr
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// 36 2 2 port
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// 38 1 1 hashfails
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// 39 1 1 failcount, connectable, optimistically_unchoked, seed
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// 40 1 1 fast_reconnects, trust_points
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// 41 1 1 source, pe_support, is_v6_addr
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// 42 1 1 on_parole, banned, added_to_dht
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// 43 1 1 <padding>
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// 44
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struct peer
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{
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peer();
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peer(boost::uint16_t port, bool connectable, int src);
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size_type total_download() const;
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size_type total_upload() const;
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libtorrent::address address() const;
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tcp::endpoint ip() const { return tcp::endpoint(address(), port); }
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// this is the accumulated amount of
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// uploaded and downloaded data to this
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// peer. It only accounts for what was
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// shared during the last connection to
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// this peer. i.e. These are only updated
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// when the connection is closed. For the
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// total amount of upload and download
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// we'll have to add thes figures with the
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// statistics from the peer_connection.
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// 48 bits can fit 256 Terabytes
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boost::uint64_t prev_amount_upload:48;
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boost::uint64_t prev_amount_download:48;
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// if the peer is connected now, this
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// will refer to a valid peer_connection
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peer_connection* connection;
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#ifndef TORRENT_DISABLE_GEO_IP
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#ifdef TORRENT_DEBUG
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// only used in debug mode to assert that
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// the first entry in the AS pair keeps the same
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boost::uint16_t inet_as_num;
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#endif
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// The AS this peer belongs to
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std::pair<const int, int>* inet_as;
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#endif
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// the time when this peer was optimistically unchoked
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// the last time. in seconds since session was created
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// 16 bits is enough to last for 18.2 hours
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// when the session time reaches 18 hours, it jumps back by
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// 9 hours, and all peers' times are updated to be
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// relative to that new time offset
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boost::uint16_t last_optimistically_unchoked;
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// the time when the peer connected to us
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// or disconnected if it isn't connected right now
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// in number of seconds since session was created
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boost::uint16_t last_connected;
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// the port this peer is or was connected on
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boost::uint16_t port;
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// the number of times this peer has been
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// part of a piece that failed the hash check
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boost::uint8_t hashfails;
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// the number of failed connection attempts
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// this peer has
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unsigned failcount:5; // [0, 31]
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// incoming peers (that don't advertize their listen port)
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// will not be considered connectable. Peers that
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// we have a listen port for will be assumed to be.
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bool connectable:1;
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// true if this peer currently is unchoked
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// because of an optimistic unchoke.
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// when the optimistic unchoke is moved to
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// another peer, this peer will be choked
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// if this is true
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bool optimistically_unchoked:1;
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// this is true if the peer is a seed
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bool seed:1;
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// the number of times we have allowed a fast
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// reconnect for this peer.
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unsigned fast_reconnects:4;
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// for every valid piece we receive where this
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// peer was one of the participants, we increase
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// this value. For every invalid piece we receive
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// where this peer was a participant, we decrease
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// this value. If it sinks below a threshold, its
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// considered a bad peer and will be banned.
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signed trust_points:4; // [-7, 8]
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// a bitmap combining the peer_source flags
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// from peer_info.
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unsigned source:6;
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#ifndef TORRENT_DISABLE_ENCRYPTION
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// Hints encryption support of peer. Only effective
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// for and when the outgoing encryption policy
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// allows both encrypted and non encrypted
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// connections (pe_settings::out_enc_policy
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// == enabled). The initial state of this flag
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// determines the initial connection attempt
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// type (true = encrypted, false = standard).
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// This will be toggled everytime either an
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// encrypted or non-encrypted handshake fails.
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bool pe_support:1;
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#endif
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#if TORRENT_USE_IPV6
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// this is true if the v6 union member in addr is
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// the one to use, false if it's the v4 one
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bool is_v6_addr:1;
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#endif
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// if this is true, the peer has previously
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// participated in a piece that failed the piece
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// hash check. This will put the peer on parole
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// and only request entire pieces. If a piece pass
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// that was partially requested from this peer it
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// will leave parole mode and continue download
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// pieces as normal peers.
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bool on_parole:1;
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// is set to true if this peer has been banned
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bool banned:1;
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#ifndef TORRENT_DISABLE_DHT
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// this is set to true when this peer as been
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// pinged by the DHT
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bool added_to_dht:1;
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#endif
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};
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struct ipv4_peer : peer
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{
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ipv4_peer(tcp::endpoint const& ip, bool connectable, int src);
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ipv4_peer(libtorrent::address const& a);
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address_v4 addr;
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};
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#if TORRENT_USE_IPV6
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struct ipv6_peer : peer
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{
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ipv6_peer(tcp::endpoint const& ip, bool connectable, int src);
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ipv6_peer(libtorrent::address const& a);
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address_v6::bytes_type addr;
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};
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#endif
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int num_peers() const { return m_peers.size(); }
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struct peer_address_compare
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{
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bool operator()(
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peer const* lhs, libtorrent::address const& rhs) const
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{
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return lhs->address() < rhs;
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}
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bool operator()(
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libtorrent::address const& lhs, peer const* rhs) const
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{
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return lhs < rhs->address();
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}
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bool operator()(
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peer const* lhs, peer const* rhs) const
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{
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return lhs->address() < rhs->address();
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}
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};
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typedef std::deque<peer*> peers_t;
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typedef peers_t::iterator iterator;
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typedef peers_t::const_iterator const_iterator;
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iterator begin_peer() { return m_peers.begin(); }
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iterator end_peer() { return m_peers.end(); }
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const_iterator begin_peer() const { return m_peers.begin(); }
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const_iterator end_peer() const { return m_peers.end(); }
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std::pair<iterator, iterator> find_peers(address const& a)
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{
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return std::equal_range(
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m_peers.begin(), m_peers.end(), a, peer_address_compare());
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}
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std::pair<const_iterator, const_iterator> find_peers(address const& a) const
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{
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return std::equal_range(
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m_peers.begin(), m_peers.end(), a, peer_address_compare());
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}
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bool connect_one_peer(int session_time);
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bool has_peer(policy::peer const* p) const;
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int num_seeds() const { return m_num_seeds; }
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int num_connect_candidates() const { return m_num_connect_candidates; }
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void recalculate_connect_candidates();
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void erase_peer(policy::peer* p);
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void erase_peer(iterator i);
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private:
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bool compare_peer_erase(policy::peer const& lhs, policy::peer const& rhs) const;
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bool compare_peer(policy::peer const& lhs, policy::peer const& rhs
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, address const& external_ip) const;
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iterator find_connect_candidate(int session_time);
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bool is_connect_candidate(peer const& p, bool finished) const;
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bool is_erase_candidate(peer const& p, bool finished) const;
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bool should_erase_immediately(peer const& p) const;
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void erase_peers();
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peers_t m_peers;
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// since the peer list can grow too large
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// to scan all of it, start at this iterator
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int m_round_robin;
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torrent* m_torrent;
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// The number of peers in our peer list
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// that are connect candidates. i.e. they're
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// not already connected and they have not
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// yet reached their max try count and they
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// have the connectable state (we have a listen
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// port for them).
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int m_num_connect_candidates;
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// the number of seeds in the peer list
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int m_num_seeds;
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// this was the state of the torrent the
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// last time we recalculated the number of
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// connect candidates. Since seeds (or upload
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// only) peers are not connect candidates
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// when we're finished, the set depends on
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// this state. Every time m_torrent->is_finished()
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// is different from this state, we need to
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// recalculate the connect candidates.
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bool m_finished;
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};
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inline policy::ipv4_peer::ipv4_peer(
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tcp::endpoint const& ip, bool connectable, int src
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)
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: peer(ip.port(), connectable, src)
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, addr(ip.address().to_v4())
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{
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is_v6_addr = false;
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}
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inline policy::ipv4_peer::ipv4_peer(libtorrent::address const& a)
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: addr(a.to_v4())
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{
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is_v6_addr = false;
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}
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inline policy::ipv6_peer::ipv6_peer(
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tcp::endpoint const& ip, bool connectable, int src
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)
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: peer(ip.port(), connectable, src)
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, addr(ip.address().to_v6().to_bytes())
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{
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is_v6_addr = true;
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}
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inline policy::ipv6_peer::ipv6_peer(libtorrent::address const& a)
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: addr(a.to_v6().to_bytes())
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{
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is_v6_addr = true;
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}
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inline libtorrent::address policy::peer::address() const
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{
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#if TORRENT_USE_IPV6
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if (is_v6_addr)
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return libtorrent::address_v6(
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static_cast<policy::ipv6_peer const*>(this)->addr);
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#endif
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return static_cast<policy::ipv4_peer const*>(this)->addr;
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}
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}
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#endif // TORRENT_POLICY_HPP_INCLUDED
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