593 lines
16 KiB
C++
593 lines
16 KiB
C++
/*
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Copyright (c) 2006-2014, Arvid Norberg & Daniel Wallin
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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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#include "libtorrent/time.hpp" // for total_seconds
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#include <libtorrent/kademlia/traversal_algorithm.hpp>
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#include <libtorrent/kademlia/routing_table.hpp>
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#include <libtorrent/kademlia/rpc_manager.hpp>
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#include <libtorrent/kademlia/node.hpp>
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#include <libtorrent/session_status.hpp>
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#include <libtorrent/socket_io.hpp> // for read_*_endpoint
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#include <boost/bind.hpp>
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namespace libtorrent { namespace dht
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{
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_DEFINE_LOG(traversal)
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#endif
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using detail::read_v4_endpoint;
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#if TORRENT_USE_IPV6
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using detail::read_v6_endpoint;
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#endif
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#if TORRENT_USE_ASSERTS
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template <class It, class Cmp>
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bool is_sorted(It b, It e, Cmp cmp)
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{
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if (b == e) return true;
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typename std::iterator_traits<It>::value_type v = *b;
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++b;
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while (b != e)
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{
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if (cmp(*b, v)) return false;
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v = *b;
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++b;
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}
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return true;
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}
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#endif
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observer_ptr traversal_algorithm::new_observer(void* ptr
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, udp::endpoint const& ep, node_id const& id)
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{
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observer_ptr o(new (ptr) null_observer(boost::intrusive_ptr<traversal_algorithm>(this), ep, id));
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#if TORRENT_USE_ASSERTS
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o->m_in_constructor = false;
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#endif
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return o;
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}
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traversal_algorithm::traversal_algorithm(
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node_impl& node
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, node_id target)
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: m_node(node)
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, m_target(target)
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, m_ref_count(0)
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, m_invoke_count(0)
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, m_branch_factor(3)
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, m_responses(0)
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, m_timeouts(0)
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{
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] NEW"
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" target: " << target
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<< " k: " << m_node.m_table.bucket_size()
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;
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#endif
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}
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void traversal_algorithm::resort_results()
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{
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std::sort(
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m_results.begin()
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, m_results.end()
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, boost::bind(
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compare_ref
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, boost::bind(&observer::id, _1)
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, boost::bind(&observer::id, _2)
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, m_target
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)
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);
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}
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void traversal_algorithm::add_entry(node_id const& id, udp::endpoint addr, unsigned char flags)
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{
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TORRENT_ASSERT(m_node.m_rpc.allocation_size() >= sizeof(find_data_observer));
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void* ptr = m_node.m_rpc.allocate_observer();
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if (ptr == 0)
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{
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] failed to allocate memory for observer. aborting!";
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#endif
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done();
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return;
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}
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observer_ptr o = new_observer(ptr, addr, id);
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if (id.is_all_zeros())
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{
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o->set_id(generate_random_id());
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o->flags |= observer::flag_no_id;
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}
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o->flags |= flags;
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TORRENT_ASSERT(libtorrent::dht::is_sorted(m_results.begin(), m_results.end()
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, boost::bind(
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compare_ref
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, boost::bind(&observer::id, _1)
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, boost::bind(&observer::id, _2)
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, m_target)
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));
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std::vector<observer_ptr>::iterator i = std::lower_bound(
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m_results.begin()
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, m_results.end()
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, o
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, boost::bind(
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compare_ref
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, boost::bind(&observer::id, _1)
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, boost::bind(&observer::id, _2)
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, m_target
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)
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);
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if (i == m_results.end() || (*i)->id() != id)
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{
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if (m_node.settings().restrict_search_ips
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&& !(flags & observer::flag_initial))
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{
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// mask the lower octet
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boost::uint32_t prefix4 = o->target_addr().to_v4().to_ulong();
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prefix4 &= 0xffffff00;
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if (m_peer4_prefixes.count(prefix4) > 0)
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{
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// we already have a node in this search with an IP very
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// close to this one. We know that it's not the same, because
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// it claims a different node-ID. Ignore this to avoid attacks
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] IGNORING result "
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<< "id: " << to_hex(o->id().to_string())
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<< " addr: " << o->target_addr()
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<< " type: " << name()
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;
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#endif
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return;
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}
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m_peer4_prefixes.insert(prefix4);
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}
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TORRENT_ASSERT((o->flags & observer::flag_no_id) || std::find_if(m_results.begin(), m_results.end()
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, boost::bind(&observer::id, _1) == id) == m_results.end());
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] ADD id: " << to_hex(id.to_string())
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<< " addr: " << addr
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<< " distance: " << distance_exp(m_target, id)
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<< " invoke-count: " << m_invoke_count
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<< " type: " << name()
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;
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#endif
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i = m_results.insert(i, o);
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TORRENT_ASSERT(libtorrent::dht::is_sorted(m_results.begin(), m_results.end()
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, boost::bind(
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compare_ref
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, boost::bind(&observer::id, _1)
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, boost::bind(&observer::id, _2)
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, m_target)
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));
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}
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if (m_results.size() > 100)
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{
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#if TORRENT_USE_ASSERTS
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for (int i = 100; i < int(m_results.size()); ++i)
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m_results[i]->m_was_abandoned = true;
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#endif
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m_results.resize(100);
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}
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}
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void traversal_algorithm::start()
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{
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// in case the routing table is empty, use the
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// router nodes in the table
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if (m_results.size() < 8) add_router_entries();
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init();
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bool is_done = add_requests();
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if (is_done) done();
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}
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void* traversal_algorithm::allocate_observer()
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{
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return m_node.m_rpc.allocate_observer();
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}
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void traversal_algorithm::free_observer(void* ptr)
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{
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m_node.m_rpc.free_observer(ptr);
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}
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char const* traversal_algorithm::name() const
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{
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return "traversal_algorithm";
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}
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void traversal_algorithm::traverse(node_id const& id, udp::endpoint addr)
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{
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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if (id.is_all_zeros())
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{
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TORRENT_LOG(traversal) << time_now_string() << "[" << this << "] WARNING node returned a list which included a node with id 0";
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}
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#endif
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// let the routing table know this node may exist
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m_node.m_table.heard_about(id, addr);
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add_entry(id, addr, 0);
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}
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void traversal_algorithm::finished(observer_ptr o)
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{
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#ifdef TORRENT_DEBUG
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std::vector<observer_ptr>::iterator i = std::find(
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m_results.begin(), m_results.end(), o);
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TORRENT_ASSERT(i != m_results.end() || m_results.size() == 100);
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#endif
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// if this flag is set, it means we increased the
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// branch factor for it, and we should restore it
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if (o->flags & observer::flag_short_timeout)
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{
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TORRENT_ASSERT(m_branch_factor > 0);
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--m_branch_factor;
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}
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TORRENT_ASSERT(o->flags & observer::flag_queried);
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o->flags |= observer::flag_alive;
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++m_responses;
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--m_invoke_count;
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TORRENT_ASSERT(m_invoke_count >= 0);
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bool is_done = add_requests();
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if (is_done) done();
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}
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// prevent request means that the total number of requests has
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// overflown. This query failed because it was the oldest one.
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// So, if this is true, don't make another request
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void traversal_algorithm::failed(observer_ptr o, int flags)
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{
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TORRENT_ASSERT(m_invoke_count >= 0);
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// don't tell the routing table about
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// node ids that we just generated ourself
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if ((o->flags & observer::flag_no_id) == 0)
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m_node.m_table.node_failed(o->id(), o->target_ep());
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if (m_results.empty()) return;
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TORRENT_ASSERT(o->flags & observer::flag_queried);
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if (flags & short_timeout)
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{
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// short timeout means that it has been more than
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// two seconds since we sent the request, and that
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// we'll most likely not get a response. But, in case
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// we do get a late response, keep the handler
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// around for some more, but open up the slot
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// by increasing the branch factor
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if ((o->flags & observer::flag_short_timeout) == 0)
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++m_branch_factor;
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o->flags |= observer::flag_short_timeout;
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] 1ST_TIMEOUT "
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<< " id: " << to_hex(o->id().to_string())
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<< " distance: " << distance_exp(m_target, o->id())
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<< " addr: " << o->target_ep()
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<< " branch-factor: " << m_branch_factor
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<< " invoke-count: " << m_invoke_count
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<< " type: " << name()
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;
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#endif
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}
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else
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{
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o->flags |= observer::flag_failed;
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// if this flag is set, it means we increased the
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// branch factor for it, and we should restore it
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if (o->flags & observer::flag_short_timeout)
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--m_branch_factor;
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] TIMEOUT "
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<< " id: " << to_hex(o->id().to_string())
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<< " distance: " << distance_exp(m_target, o->id())
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<< " addr: " << o->target_ep()
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<< " branch-factor: " << m_branch_factor
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<< " invoke-count: " << m_invoke_count
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<< " type: " << name()
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;
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#endif
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++m_timeouts;
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--m_invoke_count;
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TORRENT_ASSERT(m_invoke_count >= 0);
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}
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if (flags & prevent_request)
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{
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--m_branch_factor;
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if (m_branch_factor <= 0) m_branch_factor = 1;
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}
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bool is_done = add_requests();
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if (is_done) done();
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}
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void traversal_algorithm::done()
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{
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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int results_target = m_node.m_table.bucket_size();
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int closest_target = 160;
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for (std::vector<observer_ptr>::iterator i = m_results.begin()
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, end(m_results.end()); i != end && results_target > 0; ++i)
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{
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boost::intrusive_ptr<observer> o = *i;
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if (o->flags & observer::flag_alive)
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{
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TORRENT_ASSERT(o->flags & observer::flag_queried);
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TORRENT_LOG(traversal) << "[" << this << "] "
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<< results_target
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<< " id: " << to_hex(o->id().to_string())
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<< " distance: " << distance_exp(m_target, o->id())
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<< " addr: " << o->target_ep()
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;
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--results_target;
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int dist = distance_exp(m_target, o->id());
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if (dist < closest_target) closest_target = dist;
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}
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}
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TORRENT_LOG(traversal) << "[" << this << "] COMPLETED "
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<< "distance: " << closest_target
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<< " type: " << name()
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;
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#endif
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// delete all our references to the observer objects so
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// they will in turn release the traversal algorithm
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m_results.clear();
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}
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bool traversal_algorithm::add_requests()
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{
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int results_target = m_node.m_table.bucket_size();
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// this only counts outstanding requests at the top of the
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// target list. This is <= m_invoke count. m_invoke_count
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// is the total number of outstanding requests, including
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// old ones that may be waiting on nodes much farther behind
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// the current point we've reached in the search.
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int outstanding = 0;
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// if we're doing aggressive lookups, we keep branch-factor
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// outstanding requests _at the tops_ of the result list. Otherwise
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// we just keep any branch-factor outstanding requests
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bool agg = m_node.settings().aggressive_lookups;
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// Find the first node that hasn't already been queried.
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// and make sure that the 'm_branch_factor' top nodes
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// stay queried at all times (obviously ignoring failed nodes)
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// and without surpassing the 'result_target' nodes (i.e. k=8)
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// this is a slight variation of the original paper which instead
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// limits the number of outstanding requests, this limits the
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// number of good outstanding requests. It will use more traffic,
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// but is intended to speed up lookups
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for (std::vector<observer_ptr>::iterator i = m_results.begin()
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, end(m_results.end()); i != end
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&& results_target > 0
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&& (agg ? outstanding < m_branch_factor
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: m_invoke_count < m_branch_factor);
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++i)
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{
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observer* o = i->get();
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if (o->flags & observer::flag_alive)
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{
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TORRENT_ASSERT(o->flags & observer::flag_queried);
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--results_target;
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continue;
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}
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if (o->flags & observer::flag_queried)
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{
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// if it's queried, not alive and not failed, it
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// must be currently in flight
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if ((o->flags & observer::flag_failed) == 0)
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++outstanding;
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continue;
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}
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] INVOKE "
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<< " nodes-left: " << (m_results.end() - i)
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<< " top-invoke-count: " << outstanding
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<< " invoke-count: " << m_invoke_count
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<< " branch-factor: " << m_branch_factor
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<< " distance: " << distance_exp(m_target, o->id())
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<< " id: " << to_hex(o->id().to_string())
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<< " addr: " << o->target_ep()
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<< " type: " << name()
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;
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#endif
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o->flags |= observer::flag_queried;
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if (invoke(*i))
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{
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TORRENT_ASSERT(m_invoke_count >= 0);
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++m_invoke_count;
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++outstanding;
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}
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else
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{
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o->flags |= observer::flag_failed;
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}
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}
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// this is the completion condition. If we found m_node.m_table.bucket_size()
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// (i.e. k=8) completed results, without finding any still
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// outstanding requests, we're done.
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// also, if invoke count is 0, it means we didn't even find 'k'
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// working nodes, we still have to terminate though.
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return (results_target == 0 && outstanding == 0) || m_invoke_count == 0;
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}
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void traversal_algorithm::add_router_entries()
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{
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#ifdef TORRENT_DHT_VERBOSE_LOGGING
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TORRENT_LOG(traversal) << "[" << this << "] using router nodes to initiate traversal algorithm. "
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<< std::distance(m_node.m_table.router_begin(), m_node.m_table.router_end()) << " routers";
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#endif
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for (routing_table::router_iterator i = m_node.m_table.router_begin()
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, end(m_node.m_table.router_end()); i != end; ++i)
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{
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add_entry(node_id(0), *i, observer::flag_initial);
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}
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}
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void traversal_algorithm::init()
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{
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m_branch_factor = m_node.branch_factor();
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m_node.add_traversal_algorithm(this);
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}
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traversal_algorithm::~traversal_algorithm()
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{
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m_node.remove_traversal_algorithm(this);
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}
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void traversal_algorithm::status(dht_lookup& l)
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{
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l.timeouts = m_timeouts;
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l.responses = m_responses;
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l.outstanding_requests = m_invoke_count;
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l.branch_factor = m_branch_factor;
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l.type = name();
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l.nodes_left = 0;
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l.first_timeout = 0;
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int last_sent = INT_MAX;
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ptime now = time_now();
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for (std::vector<observer_ptr>::iterator i = m_results.begin()
|
|
, end(m_results.end()); i != end; ++i)
|
|
{
|
|
observer& o = **i;
|
|
if (o.flags & observer::flag_queried)
|
|
{
|
|
last_sent = (std::min)(last_sent, int(total_seconds(now - o.sent())));
|
|
if (o.has_short_timeout()) ++l.first_timeout;
|
|
continue;
|
|
}
|
|
++l.nodes_left;
|
|
}
|
|
l.last_sent = last_sent;
|
|
}
|
|
|
|
void traversal_observer::reply(msg const& m)
|
|
{
|
|
lazy_entry const* r = m.message.dict_find_dict("r");
|
|
if (!r)
|
|
{
|
|
#ifdef TORRENT_DHT_VERBOSE_LOGGING
|
|
TORRENT_LOG(traversal) << "[" << m_algorithm.get()
|
|
<< "] missing response dict";
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
#ifdef TORRENT_DHT_VERBOSE_LOGGING
|
|
lazy_entry const* nid = r->dict_find_string("id");
|
|
TORRENT_LOG(traversal) << "[" << m_algorithm.get() << "] "
|
|
"RESPONSE id: " << to_hex(nid->string_value())
|
|
<< " invoke-count: " << m_algorithm->invoke_count()
|
|
<< " addr: " << m.addr
|
|
<< " type: " << m_algorithm->name()
|
|
;
|
|
#endif
|
|
// look for nodes
|
|
lazy_entry const* n = r->dict_find_string("nodes");
|
|
if (n)
|
|
{
|
|
char const* nodes = n->string_ptr();
|
|
char const* end = nodes + n->string_length();
|
|
|
|
while (end - nodes >= 26)
|
|
{
|
|
node_id id;
|
|
std::copy(nodes, nodes + 20, id.begin());
|
|
nodes += 20;
|
|
m_algorithm->traverse(id, read_v4_endpoint<udp::endpoint>(nodes));
|
|
}
|
|
}
|
|
|
|
lazy_entry const* id = r->dict_find_string("id");
|
|
if (!id || id->string_length() != 20)
|
|
{
|
|
#ifdef TORRENT_DHT_VERBOSE_LOGGING
|
|
TORRENT_LOG(traversal) << "[" << m_algorithm.get() << "] invalid id in response";
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
// in case we didn't know the id of this peer when we sent the message to
|
|
// it. For instance if it's a bootstrap node.
|
|
set_id(node_id(id->string_ptr()));
|
|
}
|
|
|
|
void traversal_algorithm::abort()
|
|
{
|
|
for (std::vector<observer_ptr>::iterator i = m_results.begin()
|
|
, end(m_results.end()); i != end; ++i)
|
|
{
|
|
observer& o = **i;
|
|
if (o.flags & observer::flag_queried)
|
|
o.flags |= observer::flag_done;
|
|
}
|
|
|
|
#ifdef TORRENT_DHT_VERBOSE_LOGGING
|
|
TORRENT_LOG(traversal) << "[" << this << "] ABORTED "
|
|
<< " type: " << name()
|
|
;
|
|
#endif
|
|
|
|
done();
|
|
}
|
|
|
|
} } // namespace libtorrent::dht
|
|
|