premiere-libtorrent/include/libtorrent/utp_socket_manager.hpp

195 lines
6.5 KiB
C++

/*
Copyright (c) 2009-2016, 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_UTP_SOCKET_MANAGER_HPP_INCLUDED
#define TORRENT_UTP_SOCKET_MANAGER_HPP_INCLUDED
#include <map>
#include <functional>
#include "libtorrent/socket_type.hpp"
#include "libtorrent/session_status.hpp"
#include "libtorrent/enum_net.hpp"
#include "libtorrent/aux_/session_settings.hpp"
#include "libtorrent/span.hpp"
namespace libtorrent
{
class utp_stream;
struct utp_socket_impl;
struct counters;
struct utp_socket_manager final
{
typedef std::function<void(udp::endpoint const&
, span<char const>
, error_code&, int)> send_fun_t;
typedef std::function<void(std::shared_ptr<socket_type> const&)>
incoming_utp_callback_t;
utp_socket_manager(send_fun_t const& send_fun
, incoming_utp_callback_t const& cb
, io_service& ios
, aux::session_settings const& sett
, counters& cnt, void* ssl_context
);
~utp_socket_manager();
// return false if this is not a uTP packet
bool incoming_packet(udp::endpoint const& ep, span<char const> p);
// if the UDP socket failed with an EAGAIN or EWOULDBLOCK, this will be
// called once the socket is writeable again
void writable();
// when the upper layer has drained the underlying UDP socket, this is
// called, and uTP sockets will send their ACKs. This ensures ACKs at
// least coalese packets returned during the same wakeup
void socket_drained();
void tick(time_point now);
// flags for send_packet
enum { dont_fragment = 1 };
void send_packet(udp::endpoint const& ep, char const* p, int len
, error_code& ec, int flags = 0);
void subscribe_writable(utp_socket_impl* s);
// internal, used by utp_stream
void remove_socket(std::uint16_t id);
utp_socket_impl* new_utp_socket(utp_stream* str);
int gain_factor() const { return m_sett.get_int(settings_pack::utp_gain_factor); }
int target_delay() const { return m_sett.get_int(settings_pack::utp_target_delay) * 1000; }
int syn_resends() const { return m_sett.get_int(settings_pack::utp_syn_resends); }
int fin_resends() const { return m_sett.get_int(settings_pack::utp_fin_resends); }
int num_resends() const { return m_sett.get_int(settings_pack::utp_num_resends); }
int connect_timeout() const { return m_sett.get_int(settings_pack::utp_connect_timeout); }
int min_timeout() const { return m_sett.get_int(settings_pack::utp_min_timeout); }
int loss_multiplier() const { return m_sett.get_int(settings_pack::utp_loss_multiplier); }
void mtu_for_dest(address const& addr, int& link_mtu, int& utp_mtu);
int num_sockets() const { return int(m_utp_sockets.size()); }
void defer_ack(utp_socket_impl* s);
void subscribe_drained(utp_socket_impl* s);
void restrict_mtu(int mtu)
{
m_restrict_mtu[m_mtu_idx] = mtu;
m_mtu_idx = (m_mtu_idx + 1) % m_restrict_mtu.size();
}
int restrict_mtu() const
{
return *std::max_element(m_restrict_mtu.begin(), m_restrict_mtu.end());
}
// used to keep stats of uTP events
// the counter is the enum from ``counters``.
void inc_stats_counter(int counter, int delta = 1);
private:
// explicitly disallow assignment, to silence msvc warning
utp_socket_manager& operator=(utp_socket_manager const&);
send_fun_t m_send_fun;
incoming_utp_callback_t m_cb;
// replace with a hash-map
typedef std::multimap<std::uint16_t, utp_socket_impl*> socket_map_t;
socket_map_t m_utp_sockets;
using socket_vector_t = std::vector<utp_socket_impl*>;
// this is a list of sockets that needs to send an ack.
// once the UDP socket is drained, all of these will
// have a chance to do that. This is to avoid sending
// an ack for every single packet
socket_vector_t m_deferred_acks;
// storage used for saving cpu time on "push_back"
// by using already pre-allocated vector
socket_vector_t m_temp_sockets;
// sockets that have received or sent packets this
// round, may subscribe to the event of draining the
// UDP socket. At that point they may call the
// user callback function to indicate bytes have been
// sent or received.
socket_vector_t m_drained_event;
// list of sockets that received EWOULDBLOCK from the
// underlying socket. They are notified when the socket
// becomes writable again
socket_vector_t m_stalled_sockets;
// the last socket we received a packet on
utp_socket_impl* m_last_socket = nullptr;
int m_new_connection = -1;
aux::session_settings const& m_sett;
// this is a copy of the routing table, used
// to initialize MTU sizes of uTP sockets
mutable std::vector<ip_route> m_routes;
// the timestamp for the last time we updated
// the routing table
mutable time_point m_last_route_update = min_time();
// cache of interfaces
mutable std::vector<ip_interface> m_interfaces;
mutable time_point m_last_if_update = min_time();
// the buffer size of the socket. This is used
// to now lower the buffer size
int m_sock_buf_size = 0;
// stats counters
counters& m_counters;
io_service& m_ios;
std::array<int, 3> m_restrict_mtu;
int m_mtu_idx = 0;
// this is passed on to the instantiate connection
// if this is non-nullptr it will create SSL connections over uTP
void* m_ssl_context;
};
}
#endif