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premiere-libtorrent/src/policy.cpp

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/*
Copyright (c) 2003, Arvid Norberg
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the distribution.
* Neither the name of the author nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#include "libtorrent/pch.hpp"
#ifdef _MSC_VER
#pragma warning(push, 1)
#endif
#include <boost/bind.hpp>
#include <boost/utility.hpp>
#ifdef _MSC_VER
#pragma warning(pop)
#endif
#include "libtorrent/peer_connection.hpp"
#include "libtorrent/web_peer_connection.hpp"
#include "libtorrent/policy.hpp"
#include "libtorrent/torrent.hpp"
#include "libtorrent/socket.hpp"
#include "libtorrent/alert_types.hpp"
#include "libtorrent/invariant_check.hpp"
#include "libtorrent/time.hpp"
#include "libtorrent/aux_/session_impl.hpp"
#include "libtorrent/piece_picker.hpp"
#include "libtorrent/broadcast_socket.hpp"
#ifdef TORRENT_DEBUG
#include "libtorrent/bt_peer_connection.hpp"
#endif
namespace libtorrent
{
class peer_connection;
}
using boost::bind;
namespace
{
using namespace libtorrent;
size_type collect_free_download(
torrent::peer_iterator start
, torrent::peer_iterator end)
{
size_type accumulator = 0;
for (torrent::peer_iterator i = start; i != end; ++i)
{
// if the peer is interested in us, it means it may
// want to trade it's surplus uploads for downloads itself
// (and we should not consider it free). If the share diff is
// negative, there's no free download to get from this peer.
size_type diff = (*i)->share_diff();
TORRENT_ASSERT(diff < (std::numeric_limits<size_type>::max)());
if ((*i)->is_peer_interested() || diff <= 0)
continue;
TORRENT_ASSERT(diff > 0);
(*i)->add_free_upload(-diff);
accumulator += diff;
TORRENT_ASSERT(accumulator > 0);
}
TORRENT_ASSERT(accumulator >= 0);
return accumulator;
}
// returns the amount of free upload left after
// it has been distributed to the peers
size_type distribute_free_upload(
torrent::peer_iterator start
, torrent::peer_iterator end
, size_type free_upload)
{
if (free_upload <= 0) return free_upload;
int num_peers = 0;
size_type total_diff = 0;
for (torrent::peer_iterator i = start; i != end; ++i)
{
size_type d = (*i)->share_diff();
TORRENT_ASSERT(d < (std::numeric_limits<size_type>::max)());
total_diff += d;
if (!(*i)->is_peer_interested() || (*i)->share_diff() >= 0) continue;
++num_peers;
}
if (num_peers == 0) return free_upload;
size_type upload_share;
if (total_diff >= 0)
{
upload_share = (std::min)(free_upload, total_diff) / num_peers;
}
else
{
upload_share = (free_upload + total_diff) / num_peers;
}
if (upload_share < 0) return free_upload;
for (torrent::peer_iterator i = start; i != end; ++i)
{
peer_connection* p = *i;
if (!p->is_peer_interested() || p->share_diff() >= 0) continue;
p->add_free_upload(upload_share);
free_upload -= upload_share;
}
return free_upload;
}
struct match_peer_endpoint
{
match_peer_endpoint(tcp::endpoint const& ep)
: m_ep(ep)
{}
bool operator()(policy::peer const* p) const
{ return p->address() == m_ep.address() && p->port == m_ep.port(); }
tcp::endpoint const& m_ep;
};
#ifdef TORRENT_DEBUG
struct match_peer_connection
{
match_peer_connection(peer_connection const& c)
: m_conn(c)
{}
bool operator()(policy::peer const* p) const
{
return p->connection == &m_conn
|| (p->ip() == m_conn.remote()
&& p->connectable);
}
peer_connection const& m_conn;
};
#endif
}
namespace libtorrent
{
// returns the rank of a peer's source. We have an affinity
// to connecting to peers with higher rank. This is to avoid
// problems when out peer list is diluted by stale peers from
// the resume data for instance
int source_rank(int source_bitmask)
{
int ret = 0;
if (source_bitmask & peer_info::tracker) ret |= 1 << 5;
if (source_bitmask & peer_info::lsd) ret |= 1 << 4;
if (source_bitmask & peer_info::dht) ret |= 1 << 3;
if (source_bitmask & peer_info::pex) ret |= 1 << 2;
return ret;
}
// the case where ignore_peer is motivated is if two peers
// have only one piece that we don't have, and it's the
// same piece for both peers. Then they might get into an
// infinite loop, fighting to request the same blocks.
void request_a_block(torrent& t, peer_connection& c)
{
if (t.is_seed()) return;
if (c.no_download()) return;
TORRENT_ASSERT(t.valid_metadata());
TORRENT_ASSERT(c.peer_info_struct() != 0 || !dynamic_cast<bt_peer_connection*>(&c));
int num_requests = c.desired_queue_size()
- (int)c.download_queue().size()
- (int)c.request_queue().size();
#ifdef TORRENT_VERBOSE_LOGGING
(*c.m_logger) << time_now_string() << " PIECE_PICKER [ req: " << num_requests << " ]\n";
#endif
TORRENT_ASSERT(c.desired_queue_size() > 0);
// if our request queue is already full, we
// don't have to make any new requests yet
if (num_requests <= 0) return;
piece_picker& p = t.picker();
std::vector<piece_block> interesting_pieces;
interesting_pieces.reserve(100);
int prefer_whole_pieces = c.prefer_whole_pieces();
if (prefer_whole_pieces == 0)
{
prefer_whole_pieces = c.statistics().download_payload_rate()
* t.settings().whole_pieces_threshold
> t.torrent_file().piece_length() ? 1 : 0;
}
// if we prefer whole pieces, the piece picker will pick at least
// the number of blocks we want, but it will try to make the picked
// blocks be from whole pieces, possibly by returning more blocks
// than we requested.
#ifdef TORRENT_DEBUG
error_code ec;
TORRENT_ASSERT(c.remote() == c.get_socket()->remote_endpoint(ec) || ec);
#endif
piece_picker::piece_state_t state;
peer_connection::peer_speed_t speed = c.peer_speed();
if (speed == peer_connection::fast) state = piece_picker::fast;
else if (speed == peer_connection::medium) state = piece_picker::medium;
else state = piece_picker::slow;
// this vector is filled with the interesting pieces
// that some other peer is currently downloading
// we should then compare this peer's download speed
// with the other's, to see if we should abort another
// peer_connection in favour of this one
std::vector<piece_block> busy_pieces;
busy_pieces.reserve(num_requests);
std::vector<int> const& suggested = c.suggested_pieces();
bitfield const& bits = c.get_bitfield();
if (c.has_peer_choked())
{
// if we are choked we can only pick pieces from the
// allowed fast set. The allowed fast set is sorted
// in ascending priority order
std::vector<int> const& allowed_fast = c.allowed_fast();
// build a bitmask with only the allowed pieces in it
bitfield mask(c.get_bitfield().size(), false);
for (std::vector<int>::const_iterator i = allowed_fast.begin()
, end(allowed_fast.end()); i != end; ++i)
if (bits[*i]) mask.set_bit(*i);
p.pick_pieces(mask, interesting_pieces
, num_requests, prefer_whole_pieces, c.peer_info_struct()
, state, c.picker_options(), suggested);
}
else
{
// picks the interesting pieces from this peer
// the integer is the number of pieces that
// should be guaranteed to be available for download
// (if num_requests is too big, too many pieces are
// picked and cpu-time is wasted)
// the last argument is if we should prefer whole pieces
// for this peer. If we're downloading one piece in 20 seconds
// then use this mode.
p.pick_pieces(bits, interesting_pieces
, num_requests, prefer_whole_pieces, c.peer_info_struct()
, state, c.picker_options(), suggested);
}
#ifdef TORRENT_VERBOSE_LOGGING
(*c.m_logger) << time_now_string() << " PIECE_PICKER [ php: " << prefer_whole_pieces
<< " picked: " << interesting_pieces.size() << " ]\n";
#endif
std::vector<pending_block> const& dq = c.download_queue();
std::vector<piece_block> const& rq = c.request_queue();
for (std::vector<piece_block>::iterator i = interesting_pieces.begin();
i != interesting_pieces.end(); ++i)
{
if (prefer_whole_pieces == 0 && num_requests <= 0) break;
if (p.is_requested(*i))
{
if (num_requests <= 0) break;
// don't request pieces we already have in our request queue
if (std::find_if(dq.begin(), dq.end(), has_block(*i)) != dq.end()
|| std::find(rq.begin(), rq.end(), *i) != rq.end())
continue;
TORRENT_ASSERT(p.num_peers(*i) > 0);
busy_pieces.push_back(*i);
continue;
}
TORRENT_ASSERT(p.num_peers(*i) == 0);
// don't request pieces we already have in our request queue
if (std::find_if(dq.begin(), dq.end(), has_block(*i)) != dq.end()
|| std::find(rq.begin(), rq.end(), *i) != rq.end())
continue;
// ok, we found a piece that's not being downloaded
// by somebody else. request it from this peer
// and return
c.add_request(*i);
TORRENT_ASSERT(p.num_peers(*i) == 1);
TORRENT_ASSERT(p.is_requested(*i));
num_requests--;
}
if (busy_pieces.empty() || num_requests <= 0)
{
return;
}
// if all blocks has the same number of peers on them
// we want to pick a random block
std::random_shuffle(busy_pieces.begin(), busy_pieces.end());
// find the block with the fewest requests to it
std::vector<piece_block>::iterator i = std::min_element(
busy_pieces.begin(), busy_pieces.end()
, bind(&piece_picker::num_peers, boost::cref(p), _1) <
bind(&piece_picker::num_peers, boost::cref(p), _2));
#ifdef TORRENT_DEBUG
piece_picker::downloading_piece st;
p.piece_info(i->piece_index, st);
TORRENT_ASSERT(st.requested + st.finished + st.writing == p.blocks_in_piece(i->piece_index));
#endif
TORRENT_ASSERT(p.is_requested(*i));
TORRENT_ASSERT(p.num_peers(*i) > 0);
c.add_request(*i);
}
policy::policy(torrent* t)
: m_round_robin(0)
, m_torrent(t)
, m_available_free_upload(0)
, m_num_connect_candidates(0)
, m_num_seeds(0)
, m_finished(false)
{ TORRENT_ASSERT(t); }
// disconnects and removes all peers that are now filtered
void policy::ip_filter_updated()
{
aux::session_impl& ses = m_torrent->session();
piece_picker* p = 0;
if (m_torrent->has_picker()) p = &m_torrent->picker();
for (iterator i = m_peers.begin(); i != m_peers.end();)
{
if ((ses.m_ip_filter.access((*i)->address()) & ip_filter::blocked) == 0)
{
++i;
continue;
}
if ((*i)->connection)
{
(*i)->connection->disconnect(error_code(errors::banned_by_ip_filter, libtorrent_category));
if (ses.m_alerts.should_post<peer_blocked_alert>())
ses.m_alerts.post_alert(peer_blocked_alert((*i)->address()));
TORRENT_ASSERT((*i)->connection == 0
|| (*i)->connection->peer_info_struct() == 0);
}
else
{
if (ses.m_alerts.should_post<peer_blocked_alert>())
ses.m_alerts.post_alert(peer_blocked_alert((*i)->address()));
}
int current = i - m_peers.begin();
erase_peer(i);
i = m_peers.begin() + current;
}
}
void policy::erase_peer(policy::peer* p)
{
INVARIANT_CHECK;
std::pair<iterator, iterator> range = find_peers(p->address());
iterator iter = std::find_if(range.first, range.second, match_peer_endpoint(p->ip()));
if (iter == range.second) return;
erase_peer(iter);
}
// any peer that is erased from m_peers will be
// erased through this function. This way we can make
// sure that any references to the peer are removed
// as well, such as in the piece picker.
void policy::erase_peer(iterator i)
{
INVARIANT_CHECK;
if (m_torrent->has_picker())
m_torrent->picker().clear_peer(*i);
if ((*i)->seed) --m_num_seeds;
if (is_connect_candidate(**i, m_finished))
--m_num_connect_candidates;
if (m_round_robin > i - m_peers.begin()) --m_round_robin;
#if TORRENT_USE_IPV6
if ((*i)->is_v6_addr)
m_torrent->session().m_ipv6_peer_pool.destroy(
static_cast<ipv6_peer*>(*i));
else
#endif
m_torrent->session().m_ipv4_peer_pool.destroy(
static_cast<ipv4_peer*>(*i));
m_peers.erase(i);
}
bool policy::should_erase_immediately(peer const& p) const
{
return p.source == peer_info::resume_data
&& p.failcount > 0
&& !p.banned;
}
bool policy::is_erase_candidate(peer const& pe, bool finished) const
{
return pe.connection == 0
&& pe.last_connected != 0
&& !pe.banned
&& !is_connect_candidate(pe, m_finished);
}
void policy::erase_peers()
{
INVARIANT_CHECK;
int max_peerlist_size = m_torrent->is_paused()
?m_torrent->settings().max_paused_peerlist_size
:m_torrent->settings().max_peerlist_size;
if (max_peerlist_size == 0 || m_peers.empty()) return;
int erase_candidate = -1;
TORRENT_ASSERT(m_finished == m_torrent->is_finished());
int round_robin = rand() % m_peers.size();
for (int iterations = (std::min)(int(m_peers.size()), 300);
iterations > 0; --iterations)
{
if (m_peers.size() < max_peerlist_size * 0.95)
break;
if (round_robin == m_peers.size()) round_robin = 0;
peer& pe = *m_peers[round_robin];
int current = round_robin;
{
if (is_erase_candidate(pe, m_finished)
&& (erase_candidate == -1
|| !compare_peer_erase(*m_peers[erase_candidate], pe)))
{
if (should_erase_immediately(pe))
{
if (erase_candidate > current) --erase_candidate;
erase_peer(m_peers.begin() + current);
}
else
{
erase_candidate = current;
}
}
}
++round_robin;
}
if (erase_candidate > -1)
erase_peer(m_peers.begin() + erase_candidate);
}
bool policy::is_connect_candidate(peer const& p, bool finished) const
{
if (p.connection
|| p.banned
|| !p.connectable
|| (p.seed && finished)
|| p.failcount >= m_torrent->settings().max_failcount)
return false;
aux::session_impl const& ses = m_torrent->session();
if (ses.m_port_filter.access(p.port) & port_filter::blocked)
return false;
return true;
}
policy::iterator policy::find_connect_candidate(int session_time)
{
INVARIANT_CHECK;
int candidate = -1;
int erase_candidate = -1;
TORRENT_ASSERT(m_finished == m_torrent->is_finished());
int min_reconnect_time = m_torrent->settings().min_reconnect_time;
address external_ip = m_torrent->session().external_address();
// don't bias any particular peers when seeding
if (m_finished || external_ip == address())
{
// set external_ip to a random value, to
// radomize which peers we prefer
address_v4::bytes_type bytes;
std::generate(bytes.begin(), bytes.end(), &std::rand);
external_ip = address_v4(bytes);
}
if (m_round_robin == m_peers.size()) m_round_robin = 0;
#ifndef TORRENT_DISABLE_DHT
bool pinged = false;
#endif
int max_peerlist_size = m_torrent->is_paused()
?m_torrent->settings().max_paused_peerlist_size
:m_torrent->settings().max_peerlist_size;
for (int iterations = (std::min)(int(m_peers.size()), 300);
iterations > 0; --iterations)
{
if (m_round_robin == m_peers.size()) m_round_robin = 0;
peer& pe = *m_peers[m_round_robin];
int current = m_round_robin;
#ifndef TORRENT_DISABLE_DHT
// try to send a DHT ping to this peer
// as well, to figure out if it supports
// DHT (uTorrent and BitComet doesn't
// advertise support)
if (!pinged && !pe.added_to_dht)
{
udp::endpoint node(pe.address(), pe.port);
m_torrent->session().add_dht_node(node);
pe.added_to_dht = true;
pinged = true;
}
#endif
// if the number of peers is growing large
// we need to start weeding.
if (m_peers.size() >= max_peerlist_size * 0.95
&& max_peerlist_size > 0)
{
if (is_erase_candidate(pe, m_finished)
&& (erase_candidate == -1
|| !compare_peer_erase(*m_peers[erase_candidate], pe)))
{
if (should_erase_immediately(pe))
{
if (erase_candidate > current) --erase_candidate;
if (candidate > current) --candidate;
erase_peer(m_peers.begin() + current);
}
else
{
erase_candidate = current;
}
}
}
++m_round_robin;
if (!is_connect_candidate(pe, m_finished)) continue;
// compare peer returns true if lhs is better than rhs. In this
// case, it returns true if the current candidate is better than
// pe, which is the peer m_round_robin points to. If it is, just
// keep looking.
if (candidate != -1
&& compare_peer(*m_peers[candidate], pe, external_ip)) continue;
if (pe.last_connected
&& session_time - pe.last_connected <
(int(pe.failcount) + 1) * min_reconnect_time)
continue;
candidate = current;
}
if (erase_candidate > -1)
{
if (candidate > erase_candidate) --candidate;
erase_peer(m_peers.begin() + erase_candidate);
}
#if defined TORRENT_LOGGING || defined TORRENT_VERBOSE_LOGGING
if (candidate != -1)
{
(*m_torrent->session().m_logger) << time_now_string()
<< " *** FOUND CONNECTION CANDIDATE ["
" ip: " << m_peers[candidate]->ip() <<
" d: " << cidr_distance(external_ip, m_peers[candidate]->address()) <<
" external: " << external_ip <<
" t: " << (session_time - m_peers[candidate]->last_connected) <<
" ]\n";
}
#endif
if (candidate == -1) return m_peers.end();
return m_peers.begin() + candidate;
}
void policy::pulse()
{
INVARIANT_CHECK;
// ------------------------
// upload shift
// ------------------------
// this part will shift downloads
// from peers that are seeds and peers
// that don't want to download from us
// to peers that cannot upload anything
// to us. The shifting will make sure
// that the torrent's share ratio
// will be maintained
// if the share ratio is 0 (infinite)
// m_available_free_upload isn't used
// because it isn't necessary
if (m_torrent->ratio() != 0.f)
{
// accumulate all the free download we get
// and add it to the available free upload
m_available_free_upload
+= collect_free_download(
m_torrent->begin()
, m_torrent->end());
// distribute the free upload among the peers
m_available_free_upload = distribute_free_upload(
m_torrent->begin()
, m_torrent->end()
, m_available_free_upload);
}
erase_peers();
}
bool policy::new_connection(peer_connection& c, int session_time)
{
TORRENT_ASSERT(!c.is_local());
INVARIANT_CHECK;
// if the connection comes from the tracker,
// it's probably just a NAT-check. Ignore the
// num connections constraint then.
// TODO: only allow _one_ connection to use this
// override at a time
error_code ec;
TORRENT_ASSERT(c.remote() == c.get_socket()->remote_endpoint(ec) || ec);
TORRENT_ASSERT(!m_torrent->is_paused());
aux::session_impl& ses = m_torrent->session();
if (m_torrent->num_peers() >= m_torrent->max_connections()
&& ses.num_connections() >= ses.max_connections()
&& c.remote().address() != m_torrent->current_tracker().address())
{
c.disconnect(error_code(errors::too_many_connections, libtorrent_category));
return false;
}
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (c.remote().address() == m_torrent->current_tracker().address())
{
m_torrent->debug_log("overriding connection limit for tracker NAT-check");
}
#endif
iterator iter;
peer* i = 0;
bool found = false;
if (m_torrent->settings().allow_multiple_connections_per_ip)
{
tcp::endpoint remote = c.remote();
std::pair<iterator, iterator> range = find_peers(remote.address());
iter = std::find_if(range.first, range.second, match_peer_endpoint(remote));
if (iter != range.second) found = true;
}
else
{
iter = std::lower_bound(
m_peers.begin(), m_peers.end()
, c.remote().address(), peer_address_compare()
);
if (iter != m_peers.end() && (*iter)->address() == c.remote().address()) found = true;
}
if (found)
{
i = *iter;
if (i->banned)
{
c.disconnect(error_code(errors::peer_banned, libtorrent_category));
return false;
}
if (i->connection != 0)
{
boost::shared_ptr<socket_type> other_socket
= i->connection->get_socket();
boost::shared_ptr<socket_type> this_socket
= c.get_socket();
error_code ec1;
error_code ec2;
bool self_connection =
other_socket->remote_endpoint(ec2) == this_socket->local_endpoint(ec1)
|| other_socket->local_endpoint(ec2) == this_socket->remote_endpoint(ec1);
if (ec1)
{
c.disconnect(ec1);
return false;
}
if (self_connection)
{
c.disconnect(error_code(errors::self_connection, libtorrent_category), 1);
i->connection->disconnect(error_code(errors::self_connection, libtorrent_category), 1);
return false;
}
TORRENT_ASSERT(i->connection != &c);
// the new connection is a local (outgoing) connection
// or the current one is already connected
if (ec2)
{
i->connection->disconnect(ec2);
}
else if (!i->connection->is_connecting() || c.is_local())
{
c.disconnect(error_code(errors::duplicate_peer_id, libtorrent_category));
return false;
}
else
{
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
m_torrent->debug_log("duplicate connection. existing connection"
" is connecting and this connection is incoming. closing existing "
"connection in favour of this one");
#endif
i->connection->disconnect(error_code(errors::duplicate_peer_id, libtorrent_category));
}
}
if (m_num_connect_candidates > 0)
--m_num_connect_candidates;
}
else
{
// we don't have any info about this peer.
// add a new entry
error_code ec;
TORRENT_ASSERT(c.remote() == c.get_socket()->remote_endpoint(ec) || ec);
if (int(m_peers.size()) >= m_torrent->settings().max_peerlist_size)
{
c.disconnect(error_code(errors::too_many_connections, libtorrent_category));
return false;
}
if (m_round_robin > iter - m_peers.begin()) ++m_round_robin;
#if TORRENT_USE_IPV6
bool is_v6 = c.remote().address().is_v6();
#endif
peer* p =
#if TORRENT_USE_IPV6
is_v6 ? (peer*)m_torrent->session().m_ipv6_peer_pool.malloc() :
#endif
(peer*)m_torrent->session().m_ipv4_peer_pool.malloc();
if (p == 0) return false;
#if TORRENT_USE_IPV6
if (is_v6)
m_torrent->session().m_ipv6_peer_pool.set_next_size(500);
else
#endif
m_torrent->session().m_ipv4_peer_pool.set_next_size(500);
#if TORRENT_USE_IPV6
if (is_v6)
new (p) ipv6_peer(c.remote(), false, 0);
else
#endif
new (p) ipv4_peer(c.remote(), false, 0);
iter = m_peers.insert(iter, p);
i = *iter;
#ifndef TORRENT_DISABLE_GEO_IP
int as = ses.as_for_ip(c.remote().address());
#ifdef TORRENT_DEBUG
i->inet_as_num = as;
#endif
i->inet_as = ses.lookup_as(as);
#endif
i->source = peer_info::incoming;
}
TORRENT_ASSERT(i);
c.set_peer_info(i);
TORRENT_ASSERT(i->connection == 0);
c.add_stat(i->prev_amount_download, i->prev_amount_upload);
i->prev_amount_download = 0;
i->prev_amount_upload = 0;
i->connection = &c;
TORRENT_ASSERT(i->connection);
if (!c.fast_reconnect())
i->last_connected = session_time;
return true;
}
bool policy::update_peer_port(int port, policy::peer* p, int src)
{
TORRENT_ASSERT(p != 0);
TORRENT_ASSERT(p->connection);
if (p->port == port) return true;
if (m_torrent->settings().allow_multiple_connections_per_ip)
{
tcp::endpoint remote(p->address(), port);
std::pair<iterator, iterator> range = find_peers(remote.address());
iterator i = std::find_if(range.first, range.second
, match_peer_endpoint(remote));
if (i != m_peers.end())
{
policy::peer& pp = **i;
if (pp.connection)
{
p->connection->disconnect(error_code(errors::duplicate_peer_id, libtorrent_category));
return false;
}
erase_peer(i);
}
}
#ifdef TORRENT_DEBUG
else
{
std::pair<iterator, iterator> range = find_peers(p->address());
TORRENT_ASSERT(range.second - range.first == 1);
}
#endif
bool was_conn_cand = is_connect_candidate(*p, m_finished);
p->port = port;
p->source |= src;
p->connectable = true;
if (was_conn_cand != is_connect_candidate(*p, m_finished))
{
m_num_connect_candidates += was_conn_cand ? -1 : 1;
if (m_num_connect_candidates < 0) m_num_connect_candidates = 0;
}
return true;
}
bool policy::has_peer(policy::peer const* p) const
{
// find p in m_peers
for (const_iterator i = m_peers.begin()
, end(m_peers.end()); i != end; ++i)
{
if (*i == p) return true;
}
return false;
}
void policy::set_seed(policy::peer* p, bool s)
{
if (p == 0) return;
if (p->seed == s) return;
p->seed = s;
if (s) ++m_num_seeds;
else --m_num_seeds;
}
policy::peer* policy::add_peer(tcp::endpoint const& remote, peer_id const& pid
, int src, char flags)
{
INVARIANT_CHECK;
// just ignore the obviously invalid entries
if (remote.address() == address() || remote.port() == 0)
return 0;
aux::session_impl& ses = m_torrent->session();
port_filter const& pf = ses.m_port_filter;
if (pf.access(remote.port()) & port_filter::blocked)
{
if (ses.m_alerts.should_post<peer_blocked_alert>())
ses.m_alerts.post_alert(peer_blocked_alert(remote.address()));
return 0;
}
// if the IP is blocked, don't add it
if (ses.m_ip_filter.access(remote.address()) & ip_filter::blocked)
{
if (ses.m_alerts.should_post<peer_blocked_alert>())
{
ses.m_alerts.post_alert(peer_blocked_alert(remote.address()));
}
return 0;
}
iterator iter;
peer* i = 0;
int max_peerlist_size = m_torrent->is_paused()
?m_torrent->settings().max_paused_peerlist_size
:m_torrent->settings().max_peerlist_size;
bool found = false;
if (m_torrent->settings().allow_multiple_connections_per_ip)
{
std::pair<iterator, iterator> range = find_peers(remote.address());
iter = std::find_if(range.first, range.second, match_peer_endpoint(remote));
if (iter != range.second) found = true;
}
else
{
iter = std::lower_bound(
m_peers.begin(), m_peers.end()
, remote.address(), peer_address_compare()
);
if (iter != m_peers.end() && (*iter)->address() == remote.address()) found = true;
}
if (!found)
{
if (max_peerlist_size
&& int(m_peers.size()) >= max_peerlist_size)
{
if (src == peer_info::resume_data) return 0;
erase_peers();
if (int(m_peers.size()) >= max_peerlist_size)
return 0;
// since some peers were removed, we need to
// update the iterator to make it valid again
iter = std::lower_bound(
m_peers.begin(), m_peers.end()
, remote.address(), peer_address_compare()
);
}
if (m_round_robin > iter - m_peers.begin()) ++m_round_robin;
// we don't have any info about this peer.
// add a new entry
#if TORRENT_USE_IPV6
bool is_v6 = remote.address().is_v6();
#endif
peer* p =
#if TORRENT_USE_IPV6
is_v6 ? (peer*)m_torrent->session().m_ipv6_peer_pool.malloc() :
#endif
(peer*)m_torrent->session().m_ipv4_peer_pool.malloc();
if (p == 0) return 0;
#if TORRENT_USE_IPV6
if (is_v6)
m_torrent->session().m_ipv6_peer_pool.set_next_size(500);
else
#endif
m_torrent->session().m_ipv4_peer_pool.set_next_size(500);
#if TORRENT_USE_IPV6
if (is_v6)
new (p) ipv6_peer(remote, true, src);
else
#endif
new (p) ipv4_peer(remote, true, src);
iter = m_peers.insert(iter, p);
i = *iter;
#ifndef TORRENT_DISABLE_ENCRYPTION
if (flags & 0x01) i->pe_support = true;
#endif
if (flags & 0x02)
{
i->seed = true;
++m_num_seeds;
}
#ifndef TORRENT_DISABLE_GEO_IP
int as = ses.as_for_ip(remote.address());
#ifdef TORRENT_DEBUG
i->inet_as_num = as;
#endif
i->inet_as = ses.lookup_as(as);
#endif
if (is_connect_candidate(*i, m_finished))
++m_num_connect_candidates;
}
else
{
i = *iter;
bool was_conn_cand = is_connect_candidate(*i, m_finished);
i->connectable = true;
TORRENT_ASSERT(i->address() == remote.address());
i->port = remote.port();
i->source |= src;
// if this peer has failed before, decrease the
// counter to allow it another try, since somebody
// else is appearantly able to connect to it
// only trust this if it comes from the tracker
if (i->failcount > 0 && src == peer_info::tracker)
--i->failcount;
// if we're connected to this peer
// we already know if it's a seed or not
// so we don't have to trust this source
if ((flags & 0x02) && !i->connection)
{
if (!i->seed) ++m_num_seeds;
i->seed = true;
}
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (i->connection)
{
// this means we're already connected
// to this peer. don't connect to
// it again.
error_code ec;
char hex_pid[41];
to_hex((char*)&i->connection->pid()[0], 20, hex_pid);
char msg[200];
snprintf(msg, 200, "already connected to peer: %s %s"
, print_endpoint(remote).c_str(), hex_pid);
m_torrent->debug_log(msg);
TORRENT_ASSERT(i->connection->associated_torrent().lock().get() == m_torrent);
}
#endif
if (was_conn_cand != is_connect_candidate(*i, m_finished))
{
m_num_connect_candidates += was_conn_cand ? -1 : 1;
if (m_num_connect_candidates < 0) m_num_connect_candidates = 0;
}
}
return i;
}
// this is called when we are unchoked by a peer
// i.e. a peer lets us know that we will receive
// data from now on
void policy::unchoked(peer_connection& c)
{
INVARIANT_CHECK;
if (c.is_interesting())
{
request_a_block(*m_torrent, c);
c.send_block_requests();
}
}
// called when a peer is interested in us
void policy::interested(peer_connection& c)
{
INVARIANT_CHECK;
TORRENT_ASSERT(std::find_if(m_peers.begin(), m_peers.end()
, bind(&peer::connection, _1) == &c) != m_peers.end());
aux::session_impl& ses = m_torrent->session();
// if the peer is choked and we have upload slots left,
// then unchoke it. Another condition that has to be met
// is that the torrent doesn't keep track of the individual
// up/down ratio for each peer (ratio == 0) or (if it does
// keep track) this particular connection isn't a leecher.
// If the peer was choked because it was leeching, don't
// unchoke it again.
// The exception to this last condition is if we're a seed.
// In that case we don't care if people are leeching, they
// can't pay for their downloads anyway.
if (c.is_choked()
&& ses.num_uploads() < ses.max_uploads()
&& !c.ignore_unchoke_slots()
&& (m_torrent->ratio() == 0
|| c.share_diff() >= size_type(-free_upload_amount)
|| m_torrent->is_finished()))
{
ses.unchoke_peer(c);
}
#if defined TORRENT_VERBOSE_LOGGING
else if (c.is_choked())
{
std::string reason;
if (ses.num_uploads() >= ses.max_uploads())
{
reason = "the number of uploads ("
+ boost::lexical_cast<std::string>(ses.num_uploads())
+ ") is more than or equal to the limit ("
+ boost::lexical_cast<std::string>(ses.max_uploads())
+ ")";
}
else
{
reason = "the share ratio ("
+ boost::lexical_cast<std::string>(c.share_diff())
+ ") is <= free_upload_amount ("
+ boost::lexical_cast<std::string>(int(free_upload_amount))
+ ") and we are not seeding and the ratio ("
+ boost::lexical_cast<std::string>(m_torrent->ratio())
+ ")is non-zero";
}
(*c.m_logger) << time_now_string() << " DID NOT UNCHOKE [ " << reason << " ]\n";
}
#endif
}
// called when a peer is no longer interested in us
void policy::not_interested(peer_connection& c)
{
INVARIANT_CHECK;
if (m_torrent->ratio() != 0.f)
{
TORRENT_ASSERT(c.share_diff() < (std::numeric_limits<size_type>::max)());
size_type diff = c.share_diff();
if (diff > 0 && c.is_seed())
{
// the peer is a seed and has sent
// us more than we have sent it back.
// consider the download as free download
m_available_free_upload += diff;
c.add_free_upload(-diff);
}
}
}
/*
bool policy::unchoke_one_peer()
{
INVARIANT_CHECK;
iterator p = find_unchoke_candidate();
if (p == m_peers.end()) return false;
TORRENT_ASSERT(p->connection);
TORRENT_ASSERT(!p->connection->is_disconnecting());
TORRENT_ASSERT(p->connection->is_choked());
p->connection->send_unchoke();
p->last_optimistically_unchoked = time_now();
++m_num_unchoked;
return true;
}
void policy::choke_one_peer()
{
INVARIANT_CHECK;
iterator p = find_choke_candidate();
if (p == m_peers.end()) return;
TORRENT_ASSERT(p->connection);
TORRENT_ASSERT(!p->connection->is_disconnecting());
TORRENT_ASSERT(!p->connection->is_choked());
p->connection->send_choke();
--m_num_unchoked;
}
*/
bool policy::connect_one_peer(int session_time)
{
INVARIANT_CHECK;
TORRENT_ASSERT(m_torrent->want_more_peers());
iterator i = find_connect_candidate(session_time);
if (i == m_peers.end()) return false;
peer& p = **i;
TORRENT_ASSERT(!p.banned);
TORRENT_ASSERT(!p.connection);
TORRENT_ASSERT(p.connectable);
TORRENT_ASSERT(m_finished == m_torrent->is_finished());
TORRENT_ASSERT(is_connect_candidate(p, m_finished));
if (!m_torrent->connect_to_peer(&p))
{
// failcount is a 5 bit value
if (p.failcount < 31) ++p.failcount;
return false;
}
TORRENT_ASSERT(p.connection);
TORRENT_ASSERT(!is_connect_candidate(p, m_finished));
--m_num_connect_candidates;
return true;
}
// this is called whenever a peer connection is closed
void policy::connection_closed(const peer_connection& c, int session_time)
{
INVARIANT_CHECK;
peer* p = c.peer_info_struct();
TORRENT_ASSERT((std::find_if(
m_peers.begin()
, m_peers.end()
, match_peer_connection(c))
!= m_peers.end()) == (p != 0));
// if we couldn't find the connection in our list, just ignore it.
if (p == 0) return;
TORRENT_ASSERT(p->connection == &c);
p->connection = 0;
p->optimistically_unchoked = false;
// if fast reconnect is true, we won't
// update the timestamp, and it will remain
// the time when we initiated the connection.
if (!c.fast_reconnect())
p->last_connected = session_time;
if (c.failed())
{
// failcount is a 5 bit value
if (p->failcount < 31) ++p->failcount;
}
if (is_connect_candidate(*p, m_finished))
++m_num_connect_candidates;
// if the share ratio is 0 (infinite), the
// m_available_free_upload isn't used,
// because it isn't necessary.
if (m_torrent->ratio() != 0.f)
{
TORRENT_ASSERT(c.associated_torrent().lock().get() == m_torrent);
TORRENT_ASSERT(c.share_diff() < (std::numeric_limits<size_type>::max)());
m_available_free_upload += c.share_diff();
}
TORRENT_ASSERT(p->prev_amount_upload == 0);
TORRENT_ASSERT(p->prev_amount_download == 0);
p->prev_amount_download += c.statistics().total_payload_download();
p->prev_amount_upload += c.statistics().total_payload_upload();
// if we're already a seed, it's not as important
// to keep all the possibly stale peers
// if we're not a seed, but we have too many peers
// start weeding the ones we only know from resume
// data first
if (m_torrent->is_seed() || m_peers.size() >= m_torrent->settings().max_peerlist_size * 0.9)
{
if (p->source == peer_info::resume_data)
erase_peer(p);
}
}
void policy::peer_is_interesting(peer_connection& c)
{
INVARIANT_CHECK;
// no peer should be interesting if we're finished
TORRENT_ASSERT(!m_torrent->is_finished());
if (c.in_handshake()) return;
c.send_interested();
if (c.has_peer_choked()
&& c.allowed_fast().empty())
return;
request_a_block(*m_torrent, c);
c.send_block_requests();
}
void policy::recalculate_connect_candidates()
{
m_num_connect_candidates = 0;
const bool is_finished = m_torrent->is_finished();
if (is_finished == m_finished) return;
m_finished = is_finished;
for (const_iterator i = m_peers.begin();
i != m_peers.end(); ++i)
{
m_num_connect_candidates += is_connect_candidate(**i, m_finished);
}
}
#ifdef TORRENT_DEBUG
bool policy::has_connection(const peer_connection* c)
{
INVARIANT_CHECK;
TORRENT_ASSERT(c);
error_code ec;
TORRENT_ASSERT(c->remote() == c->get_socket()->remote_endpoint(ec) || ec);
return std::find_if(
m_peers.begin()
, m_peers.end()
, match_peer_connection(*c)) != m_peers.end();
}
void policy::check_invariant() const
{
TORRENT_ASSERT(m_num_connect_candidates >= 0);
TORRENT_ASSERT(m_num_connect_candidates <= m_peers.size());
if (m_torrent->is_aborted()) return;
#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
int connected_peers = 0;
int total_connections = 0;
int nonempty_connections = 0;
std::set<tcp::endpoint> unique_test;
const_iterator prev = m_peers.end();
for (const_iterator i = m_peers.begin();
i != m_peers.end(); ++i)
{
if (prev != m_peers.end()) ++prev;
if (i == m_peers.begin() + 1) prev = m_peers.begin();
if (prev != m_peers.end())
{
if (m_torrent->settings().allow_multiple_connections_per_ip)
TORRENT_ASSERT(!((*i)->address() < (*prev)->address()));
else
TORRENT_ASSERT((*prev)->address() < (*i)->address());
}
peer const& p = **i;
#ifndef TORRENT_DISABLE_GEO_IP
TORRENT_ASSERT(p.inet_as == 0 || p.inet_as->first == p.inet_as_num);
#endif
if (!m_torrent->settings().allow_multiple_connections_per_ip)
{
std::pair<const_iterator, const_iterator> range = find_peers(p.address());
TORRENT_ASSERT(range.second - range.first == 1);
}
else
{
TORRENT_ASSERT(unique_test.count(p.ip()) == 0);
unique_test.insert(p.ip());
// TORRENT_ASSERT(p.connection == 0 || p.ip() == p.connection->remote());
}
++total_connections;
if (!p.connection)
{
continue;
}
TORRENT_ASSERT(p.prev_amount_upload == 0);
TORRENT_ASSERT(p.prev_amount_download == 0);
if (p.optimistically_unchoked)
{
TORRENT_ASSERT(p.connection);
TORRENT_ASSERT(!p.connection->is_choked());
}
TORRENT_ASSERT(p.connection->peer_info_struct() == 0
|| p.connection->peer_info_struct() == &p);
++nonempty_connections;
if (!p.connection->is_disconnecting())
++connected_peers;
}
int num_torrent_peers = 0;
for (torrent::const_peer_iterator i = m_torrent->begin();
i != m_torrent->end(); ++i)
{
if ((*i)->is_disconnecting()) continue;
// ignore web_peer_connections since they are not managed
// by the policy class
if (dynamic_cast<web_peer_connection*>(*i)) continue;
++num_torrent_peers;
}
if (m_torrent->has_picker())
{
piece_picker& p = m_torrent->picker();
std::vector<piece_picker::downloading_piece> downloaders = p.get_download_queue();
std::set<void*> peer_set;
std::vector<void*> peers;
for (std::vector<piece_picker::downloading_piece>::iterator i = downloaders.begin()
, end(downloaders.end()); i != end; ++i)
{
p.get_downloaders(peers, i->index);
std::copy(peers.begin(), peers.end()
, std::insert_iterator<std::set<void*> >(peer_set, peer_set.begin()));
}
for (std::set<void*>::iterator i = peer_set.begin()
, end(peer_set.end()); i != end; ++i)
{
policy::peer* p = static_cast<policy::peer*>(*i);
if (p == 0) continue;
if (p->connection == 0) continue;
TORRENT_ASSERT(std::find_if(m_peers.begin(), m_peers.end()
, match_peer_connection(*p->connection)) != m_peers.end());
}
}
#endif // TORRENT_EXPENSIVE_INVARIANT_CHECKS
// this invariant is a bit complicated.
// the usual case should be that connected_peers
// == num_torrent_peers. But when there's an incoming
// connection, it will first be added to the policy
// and then be added to the torrent.
// When there's an outgoing connection, it will first
// be added to the torrent and then to the policy.
// that's why the two second cases are in there.
/*
TORRENT_ASSERT(connected_peers == num_torrent_peers
|| (connected_peers == num_torrent_peers + 1
&& connected_peers > 0)
|| (connected_peers + 1 == num_torrent_peers
&& num_torrent_peers > 0));
*/
}
#endif // TORRENT_DEBUG
policy::peer::peer()
{}
policy::peer::peer(boost::uint16_t port, bool conn, int src)
: prev_amount_upload(0)
, prev_amount_download(0)
, connection(0)
#ifndef TORRENT_DISABLE_GEO_IP
, inet_as(0)
#endif
, last_optimistically_unchoked(0)
, last_connected(0)
, port(port)
, hashfails(0)
, failcount(0)
, connectable(conn)
, optimistically_unchoked(false)
, seed(false)
, fast_reconnects(0)
, trust_points(0)
, source(src)
#ifndef TORRENT_DISABLE_ENCRYPTION
, pe_support(true)
#endif
#if TORRENT_USE_IPV6
, is_v6_addr(false)
#endif
, on_parole(false)
, banned(false)
#ifndef TORRENT_DISABLE_DHT
, added_to_dht(false)
#endif
{
TORRENT_ASSERT((src & 0xff) == src);
}
size_type policy::peer::total_download() const
{
if (connection != 0)
{
TORRENT_ASSERT(prev_amount_download == 0);
return connection->statistics().total_payload_download();
}
else
{
return prev_amount_download;
}
}
size_type policy::peer::total_upload() const
{
if (connection != 0)
{
TORRENT_ASSERT(prev_amount_upload == 0);
return connection->statistics().total_payload_upload();
}
else
{
return prev_amount_upload;
}
}
// this returns true if lhs is a better erase candidate than rhs
bool policy::compare_peer_erase(policy::peer const& lhs, policy::peer const& rhs) const
{
bool lhs_resume_data_source = lhs.source == peer_info::resume_data;
bool rhs_resume_data_source = rhs.source == peer_info::resume_data;
// prefer to drop peers whose only source is resume data
if (lhs_resume_data_source != rhs_resume_data_source)
return lhs_resume_data_source > rhs_resume_data_source;
// prefer peers with higher failcount
return lhs.failcount > rhs.failcount;
}
// this returns true if lhs is a better connect candidate than rhs
bool policy::compare_peer(policy::peer const& lhs, policy::peer const& rhs
, address const& external_ip) const
{
// prefer peers with lower failcount
if (lhs.failcount != rhs.failcount)
return lhs.failcount < rhs.failcount;
// Local peers should always be tried first
bool lhs_local = is_local(lhs.address());
bool rhs_local = is_local(rhs.address());
if (lhs_local != rhs_local) return lhs_local > rhs_local;
if (lhs.last_connected != rhs.last_connected)
return lhs.last_connected < rhs.last_connected;
int lhs_rank = source_rank(lhs.source);
int rhs_rank = source_rank(rhs.source);
if (lhs_rank != rhs_rank) return lhs_rank > rhs_rank;
#ifndef TORRENT_DISABLE_GEO_IP
// don't bias fast peers when seeding
if (!m_finished && m_torrent->session().has_asnum_db())
{
int lhs_as = lhs.inet_as ? lhs.inet_as->second : 0;
int rhs_as = rhs.inet_as ? rhs.inet_as->second : 0;
if (lhs_as != rhs_as) return lhs_as > rhs_as;
}
#endif
int lhs_distance = cidr_distance(external_ip, lhs.address());
int rhs_distance = cidr_distance(external_ip, rhs.address());
if (lhs_distance < rhs_distance) return true;
return false;
}
}
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