forked from premiere/premiere-libtorrent
137 lines
4.6 KiB
C++
137 lines
4.6 KiB
C++
/*
|
|
|
|
Copyright (c) 2013-2016, 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.
|
|
|
|
*/
|
|
|
|
#ifndef TORRENT_IP_VOTER_HPP_INCLUDED
|
|
#define TORRENT_IP_VOTER_HPP_INCLUDED
|
|
|
|
#include <vector>
|
|
#include "libtorrent/address.hpp"
|
|
#include "libtorrent/bloom_filter.hpp"
|
|
#include "libtorrent/time.hpp" // for time_point
|
|
#include "libtorrent/aux_/session_interface.hpp" // for ip_source_t
|
|
|
|
namespace libtorrent {
|
|
|
|
// this is an object that keeps the state for a single external IP
|
|
// based on peoples votes
|
|
struct TORRENT_EXTRA_EXPORT ip_voter
|
|
{
|
|
ip_voter();
|
|
|
|
// returns true if a different IP is the top vote now
|
|
// i.e. we changed our idea of what our external IP is
|
|
bool cast_vote(address const& ip, aux::ip_source_t source_type, address const& source);
|
|
|
|
address external_address() const { return m_external_address; }
|
|
|
|
private:
|
|
|
|
bool maybe_rotate();
|
|
|
|
struct external_ip_t
|
|
{
|
|
bool add_vote(sha1_hash const& k, aux::ip_source_t type);
|
|
|
|
// we want to sort descending
|
|
bool operator<(external_ip_t const& rhs) const
|
|
{
|
|
if (num_votes > rhs.num_votes) return true;
|
|
if (num_votes < rhs.num_votes) return false;
|
|
return static_cast<std::uint8_t>(sources) > static_cast<std::uint8_t>(rhs.sources);
|
|
}
|
|
|
|
// this is a bloom filter of the IPs that have
|
|
// reported this address
|
|
bloom_filter<16> voters;
|
|
// this is the actual external address
|
|
address addr;
|
|
// a bitmask of sources the reporters have come from
|
|
aux::ip_source_t sources{};
|
|
// the total number of votes for this IP
|
|
std::uint16_t num_votes = 0;
|
|
};
|
|
|
|
// this is a bloom filter of all the IPs that have
|
|
// been the first to report an external address. Each
|
|
// IP only gets to add a new item once.
|
|
bloom_filter<32> m_external_address_voters;
|
|
|
|
std::vector<external_ip_t> m_external_addresses;
|
|
address m_external_address;
|
|
|
|
// the total number of unique IPs that have voted
|
|
int m_total_votes;
|
|
|
|
// this is true from the first time we rotate. Before
|
|
// we rotate for the first time, we keep updating the
|
|
// external address as we go, since we don't have any
|
|
// stable setting to fall back on. Once this is true,
|
|
// we stop updating it on the fly, and just use the
|
|
// address from when we rotated.
|
|
bool m_valid_external;
|
|
|
|
// the last time we rotated this ip_voter. i.e. threw
|
|
// away all the votes and started from scratch, in case
|
|
// our IP has changed
|
|
time_point m_last_rotate;
|
|
};
|
|
|
|
// stores one address for each combination of local/global and ipv4/ipv6
|
|
// use of this class should be avoided, get the IP from the appropriate
|
|
// listen interface wherever possible
|
|
struct TORRENT_EXTRA_EXPORT external_ip
|
|
{
|
|
external_ip()
|
|
#if TORRENT_USE_IPV6
|
|
: m_addresses{{address_v4(), address_v6()}, {address_v4(), address_v6()}}
|
|
#endif
|
|
{}
|
|
|
|
external_ip(address const& local4, address const& global4
|
|
, address const& local6, address const& global6);
|
|
|
|
// the external IP as it would be observed from `ip`
|
|
address external_address(address const& ip) const;
|
|
|
|
private:
|
|
|
|
// support one local and one global address per address family
|
|
// [0][n] = global [1][n] = local
|
|
// [n][0] = IPv4 [n][1] = IPv6
|
|
// TODO: 1 have one instance per possible subnet, 192.168.x.x, 10.x.x.x, etc.
|
|
address m_addresses[2][2];
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|