premiere-libtorrent/src/natpmp.cpp

683 lines
18 KiB
C++

/*
Copyright (c) 2007-2016, 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.
*/
#include "libtorrent/config.hpp"
#include "libtorrent/aux_/disable_warnings_push.hpp"
#if defined TORRENT_OS2
#include <pthread.h>
#endif
#include <boost/asio/ip/host_name.hpp>
#include "libtorrent/aux_/disable_warnings_pop.hpp"
#include <cstdio> // for snprintf
#include <cinttypes> // for PRId64 et.al.
#include <cstdarg>
#include <functional>
#include <cstring> // for memcpy
#include "libtorrent/natpmp.hpp"
#include "libtorrent/io.hpp"
#include "libtorrent/assert.hpp"
#include "libtorrent/enum_net.hpp"
#include "libtorrent/socket_io.hpp"
#include "libtorrent/io_service.hpp"
#include "libtorrent/aux_/time.hpp"
#include "libtorrent/debug.hpp"
#include "libtorrent/aux_/escape_string.hpp"
#include "libtorrent/aux_/numeric_cast.hpp"
namespace libtorrent {
using namespace aux;
using namespace std::placeholders;
natpmp::natpmp(io_service& ios
, aux::portmap_callback& cb)
: m_callback(cb)
, m_socket(ios)
, m_send_timer(ios)
, m_refresh_timer(ios)
{
// unfortunately async operations rely on the storage
// for this array not to be reallocated, by passing
// around pointers to its elements. so reserve size for now
m_mappings.reserve(10);
}
void natpmp::start()
{
TORRENT_ASSERT(is_single_thread());
error_code ec;
address gateway = get_default_gateway(m_socket.get_io_service(), ec);
if (ec)
{
#ifndef TORRENT_DISABLE_LOGGING
if (should_log())
{
log("failed to find default route: %s"
, convert_from_native(ec.message()).c_str());
}
#endif
disable(ec);
return;
}
m_disabled = false;
udp::endpoint nat_endpoint(gateway, 5351);
if (nat_endpoint == m_nat_endpoint) return;
m_nat_endpoint = nat_endpoint;
#ifndef TORRENT_DISABLE_LOGGING
if (should_log())
{
log("found router at: %s"
, print_address(m_nat_endpoint.address()).c_str());
}
#endif
m_socket.open(udp::v4(), ec);
if (ec)
{
disable(ec);
return;
}
m_socket.bind(udp::endpoint(address_v4::any(), 0), ec);
if (ec)
{
disable(ec);
return;
}
ADD_OUTSTANDING_ASYNC("natpmp::on_reply");
m_socket.async_receive_from(boost::asio::buffer(&m_response_buffer[0]
, sizeof(m_response_buffer))
, m_remote, std::bind(&natpmp::on_reply, self(), _1, _2));
send_get_ip_address_request();
for (std::vector<mapping_t>::iterator i = m_mappings.begin()
, end(m_mappings.end()); i != end; ++i)
{
if (i->protocol == portmap_protocol::none
|| i->act != portmap_action::none)
continue;
i->act = portmap_action::add;
update_mapping(port_mapping_t(int(i - m_mappings.begin())));
}
}
void natpmp::send_get_ip_address_request()
{
TORRENT_ASSERT(is_single_thread());
using namespace libtorrent::detail;
char buf[2];
char* out = buf;
write_uint8(0, out); // NAT-PMP version
write_uint8(0, out); // public IP address request opcode
#ifndef TORRENT_DISABLE_LOGGING
log("==> get public IP address");
#endif
error_code ec;
m_socket.send_to(boost::asio::buffer(buf, sizeof(buf)), m_nat_endpoint, 0, ec);
}
bool natpmp::get_mapping(port_mapping_t const index, int& local_port
, int& external_port, portmap_protocol& protocol) const
{
TORRENT_ASSERT(is_single_thread());
TORRENT_ASSERT(index < m_mappings.end_index() && index >= port_mapping_t{});
if (index >= m_mappings.end_index() || index < port_mapping_t{}) return false;
mapping_t const& m = m_mappings[index];
if (m.protocol == portmap_protocol::none) return false;
local_port = m.local_port;
external_port = m.external_port;
protocol = m.protocol;
return true;
}
#ifndef TORRENT_DISABLE_LOGGING
bool natpmp::should_log() const
{
return m_callback.should_log_portmap(portmap_transport::natpmp);
}
void natpmp::mapping_log(char const* op, mapping_t const& m) const
{
if (should_log())
{
log("%s-mapping: proto: %s port: %d local-port: %d action: %s ttl: %" PRId64
, op
, m.protocol == portmap_protocol::none
? "none" : to_string(m.protocol)
, m.external_port
, m.local_port
, to_string(m.act)
, total_seconds(m.expires - aux::time_now()));
}
}
TORRENT_FORMAT(2, 3)
void natpmp::log(char const* fmt, ...) const
{
TORRENT_ASSERT(is_single_thread());
if (!should_log()) return;
char msg[200];
va_list v;
va_start(v, fmt);
std::vsnprintf(msg, sizeof(msg), fmt, v);
va_end(v);
m_callback.log_portmap(portmap_transport::natpmp, msg);
}
#endif
void natpmp::disable(error_code const& ec)
{
TORRENT_ASSERT(is_single_thread());
m_disabled = true;
for (std::vector<mapping_t>::iterator i = m_mappings.begin()
, end(m_mappings.end()); i != end; ++i)
{
if (i->protocol == portmap_protocol::none) continue;
portmap_protocol const proto = i->protocol;
i->protocol = portmap_protocol::none;
port_mapping_t const index(static_cast<int>(i - m_mappings.begin()));
m_callback.on_port_mapping(index, address(), 0, proto, ec
, portmap_transport::natpmp);
}
close_impl();
}
void natpmp::delete_mapping(port_mapping_t const index)
{
TORRENT_ASSERT(is_single_thread());
TORRENT_ASSERT(index < m_mappings.end_index() && index >= port_mapping_t{});
if (index >= m_mappings.end_index() || index < port_mapping_t{}) return;
mapping_t& m = m_mappings[index];
if (m.protocol == portmap_protocol::none) return;
if (!m.map_sent)
{
m.act = portmap_action::none;
m.protocol = portmap_protocol::none;
return;
}
m.act = portmap_action::del;
update_mapping(index);
}
port_mapping_t natpmp::add_mapping(portmap_protocol const p, int const external_port
, tcp::endpoint const local_ep)
{
TORRENT_ASSERT(is_single_thread());
if (m_disabled) return port_mapping_t{-1};
auto i = std::find_if(m_mappings.begin()
, m_mappings.end(), [] (mapping_t const& m) { return m.protocol == portmap_protocol::none; });
if (i == m_mappings.end())
{
m_mappings.push_back(mapping_t());
i = m_mappings.end() - 1;
}
i->protocol = p;
i->external_port = external_port;
i->local_port = local_ep.port();
i->act = portmap_action::add;
port_mapping_t const mapping_index(static_cast<int>(i - m_mappings.begin()));
#ifndef TORRENT_DISABLE_LOGGING
mapping_log("add",*i);
#endif
update_mapping(mapping_index);
return port_mapping_t{mapping_index};
}
void natpmp::try_next_mapping(port_mapping_t const i)
{
TORRENT_ASSERT(is_single_thread());
if (i < prev(m_mappings.end_index()))
{
update_mapping(next(i));
return;
}
auto const m = std::find_if(
m_mappings.begin(), m_mappings.end()
, [] (mapping_t const& ma) { return ma.act != portmap_action::none
&& ma.protocol != portmap_protocol::none; });
if (m == m_mappings.end())
{
if (m_abort)
{
error_code ec;
m_send_timer.cancel(ec);
m_socket.close(ec);
}
return;
}
update_mapping(port_mapping_t(static_cast<int>(m - m_mappings.begin())));
}
void natpmp::update_mapping(port_mapping_t const i)
{
TORRENT_ASSERT(is_single_thread());
if (i == m_mappings.end_index())
{
if (m_abort)
{
error_code ec;
m_send_timer.cancel(ec);
m_socket.close(ec);
}
return;
}
natpmp::mapping_t const& m = m_mappings[i];
#ifndef TORRENT_DISABLE_LOGGING
mapping_log("update", m);
#endif
if (m.act == portmap_action::none
|| m.protocol == portmap_protocol::none)
{
try_next_mapping(i);
return;
}
if (m_currently_mapping == port_mapping_t{-1})
{
// the socket is not currently in use
// send out a mapping request
m_retry_count = 0;
send_map_request(i);
}
}
void natpmp::send_map_request(port_mapping_t const i)
{
TORRENT_ASSERT(is_single_thread());
using namespace libtorrent::detail;
TORRENT_ASSERT(m_currently_mapping == port_mapping_t{-1}
|| m_currently_mapping == i);
m_currently_mapping = i;
mapping_t& m = m_mappings[i];
TORRENT_ASSERT(m.act != portmap_action::none);
char buf[12];
char* out = buf;
write_uint8(0, out); // NAT-PMP version
write_uint8(m.protocol == portmap_protocol::udp ? 1 : 2, out); // map "protocol"
write_uint16(0, out); // reserved
write_uint16(m.local_port, out); // private port
write_uint16(m.external_port, out); // requested public port
int ttl = m.act == portmap_action::add ? 3600 : 0;
write_uint32(ttl, out); // port mapping lifetime
#ifndef TORRENT_DISABLE_LOGGING
if (should_log())
{
log("==> port map [ mapping: %d action: %s"
" proto: %s local: %u external: %u ttl: %u ]"
, static_cast<int>(i), to_string(m.act)
, to_string(m.protocol)
, m.local_port, m.external_port, ttl);
}
#endif
error_code ec;
m_socket.send_to(boost::asio::buffer(buf, sizeof(buf)), m_nat_endpoint, 0, ec);
m.map_sent = true;
m.outstanding_request = true;
if (m_abort)
{
// when we're shutting down, ignore the
// responses and just remove all mappings
// immediately
m_currently_mapping = port_mapping_t{-1};
m.act = portmap_action::none;
try_next_mapping(i);
}
else
{
ADD_OUTSTANDING_ASYNC("natpmp::resend_request");
// linear back-off instead of exponential
++m_retry_count;
m_send_timer.expires_from_now(milliseconds(250 * m_retry_count), ec);
m_send_timer.async_wait(std::bind(&natpmp::resend_request, self(), i, _1));
}
}
void natpmp::resend_request(port_mapping_t const i, error_code const& e)
{
TORRENT_ASSERT(is_single_thread());
COMPLETE_ASYNC("natpmp::resend_request");
if (e) return;
if (m_currently_mapping != i) return;
// if we're shutting down, don't retry, just move on
// to the next mapping
if (m_retry_count >= 9 || m_abort)
{
m_currently_mapping = port_mapping_t{-1};
m_mappings[i].act = portmap_action::none;
// try again in two hours
m_mappings[i].expires = aux::time_now() + hours(2);
try_next_mapping(i);
return;
}
send_map_request(i);
}
void natpmp::on_reply(error_code const& e
, std::size_t bytes_transferred)
{
TORRENT_ASSERT(is_single_thread());
COMPLETE_ASYNC("natpmp::on_reply");
using namespace libtorrent::detail;
if (e)
{
#ifndef TORRENT_DISABLE_LOGGING
if (should_log())
{
log("error on receiving reply: %s"
, convert_from_native(e.message()).c_str());
}
#endif
return;
}
ADD_OUTSTANDING_ASYNC("natpmp::on_reply");
// make a copy of the response packet buffer
// to avoid overwriting it in the next receive call
char msg_buf[sizeof(m_response_buffer)];
std::memcpy(msg_buf, m_response_buffer, bytes_transferred);
m_socket.async_receive_from(boost::asio::buffer(&m_response_buffer[0]
, sizeof(m_response_buffer))
, m_remote, std::bind(&natpmp::on_reply, self(), _1, _2));
if (m_remote != m_nat_endpoint)
{
#ifndef TORRENT_DISABLE_LOGGING
if (should_log())
{
log("received packet from wrong IP: %s"
, print_endpoint(m_remote).c_str());
}
#endif
return;
}
error_code ec;
m_send_timer.cancel(ec);
if (bytes_transferred < 12)
{
#ifndef TORRENT_DISABLE_LOGGING
log("received packet of invalid size: %d", int(bytes_transferred));
#endif
return;
}
char* in = msg_buf;
int version = read_uint8(in);
int cmd = read_uint8(in);
int result = read_uint16(in);
int time = aux::numeric_cast<int>(read_uint32(in));
TORRENT_UNUSED(version);
TORRENT_UNUSED(time);
if (cmd == 128)
{
// public IP request response
m_external_ip = read_v4_address(in);
#ifndef TORRENT_DISABLE_LOGGING
if (should_log())
{
log("<== public IP address [ %s ]", print_address(m_external_ip).c_str());
}
#endif
return;
}
if (bytes_transferred != 16)
{
#ifndef TORRENT_DISABLE_LOGGING
log("received packet of invalid size: %d", int(bytes_transferred));
#endif
return;
}
int const private_port = read_uint16(in);
int const public_port = read_uint16(in);
int const lifetime = aux::numeric_cast<int>(read_uint32(in));
portmap_protocol const protocol = (cmd - 128 == 1)
? portmap_protocol::udp
: portmap_protocol::tcp;
#ifndef TORRENT_DISABLE_LOGGING
char msg[200];
int num_chars = std::snprintf(msg, sizeof(msg), "<== port map ["
" protocol: %s local: %u external: %u ttl: %u ]"
, (cmd - 128 == 1 ? "udp" : "tcp")
, private_port, public_port, lifetime);
if (version != 0)
{
std::snprintf(msg + num_chars, sizeof(msg) - aux::numeric_cast<std::size_t>(num_chars), "unexpected version: %u"
, version);
log("%s", msg);
}
#endif
mapping_t* m = nullptr;
port_mapping_t index{-1};
for (auto i = m_mappings.begin(), end(m_mappings.end()); i != end; ++i)
{
if (private_port != i->local_port) continue;
if (protocol != i->protocol) continue;
if (!i->map_sent) continue;
if (!i->outstanding_request) continue;
m = &*i;
index = port_mapping_t(static_cast<int>(i - m_mappings.begin()));
break;
}
if (m == nullptr)
{
#ifndef TORRENT_DISABLE_LOGGING
snprintf(msg + num_chars, sizeof(msg) - aux::numeric_cast<std::size_t>(num_chars), " not found in map table");
log("%s", msg);
#endif
return;
}
m->outstanding_request = false;
#ifndef TORRENT_DISABLE_LOGGING
log("%s", msg);
#endif
if (public_port == 0 || lifetime == 0)
{
// this means the mapping was
// successfully closed
m->protocol = portmap_protocol::none;
}
else
{
m->expires = aux::time_now() + seconds(int(lifetime * 0.7f));
m->external_port = public_port;
}
if (result != 0)
{
// TODO: 3 it would be nice to have a separate NAT-PMP error category
static errors::error_code_enum const errors[] =
{
errors::unsupported_protocol_version,
errors::natpmp_not_authorized,
errors::network_failure,
errors::no_resources,
errors::unsupported_opcode
};
errors::error_code_enum ev = errors::no_error;
if (result >= 1 && result <= 5) ev = errors[result - 1];
m->expires = aux::time_now() + hours(2);
portmap_protocol const proto = m->protocol;
m_callback.on_port_mapping(port_mapping_t{index}, address(), 0, proto
, ev, portmap_transport::natpmp);
}
else if (m->act == portmap_action::add)
{
portmap_protocol const proto = m->protocol;
m_callback.on_port_mapping(port_mapping_t{index}, m_external_ip, m->external_port, proto
, errors::no_error, portmap_transport::natpmp);
}
if (m_abort) return;
m_currently_mapping = port_mapping_t{-1};
m->act = portmap_action::none;
m_send_timer.cancel(ec);
update_expiration_timer();
try_next_mapping(index);
}
void natpmp::update_expiration_timer()
{
TORRENT_ASSERT(is_single_thread());
if (m_abort) return;
time_point const now = aux::time_now() + milliseconds(100);
time_point min_expire = now + seconds(3600);
port_mapping_t min_index{-1};
for (std::vector<mapping_t>::iterator i = m_mappings.begin()
, end(m_mappings.end()); i != end; ++i)
{
if (i->protocol == portmap_protocol::none
|| i->act != portmap_action::none) continue;
port_mapping_t const index(static_cast<int>(i - m_mappings.begin()));
if (i->expires < now)
{
#ifndef TORRENT_DISABLE_LOGGING
log("mapping %u expired", static_cast<int>(index));
#endif
i->act = portmap_action::add;
if (m_next_refresh == index) m_next_refresh = port_mapping_t{-1};
update_mapping(index);
}
else if (i->expires < min_expire)
{
min_expire = i->expires;
min_index = index;
}
}
// this is already the mapping we're waiting for
if (m_next_refresh == min_index) return;
if (min_index >= port_mapping_t{})
{
#ifndef TORRENT_DISABLE_LOGGING
log("next expiration [ idx: %d ttl: %" PRId64 " ]"
, static_cast<int>(min_index), total_seconds(min_expire - aux::time_now()));
#endif
error_code ec;
if (m_next_refresh >= port_mapping_t{}) m_refresh_timer.cancel(ec);
ADD_OUTSTANDING_ASYNC("natpmp::mapping_expired");
m_refresh_timer.expires_from_now(min_expire - now, ec);
m_refresh_timer.async_wait(std::bind(&natpmp::mapping_expired, self(), _1, min_index));
m_next_refresh = min_index;
}
}
void natpmp::mapping_expired(error_code const& e, port_mapping_t const i)
{
TORRENT_ASSERT(is_single_thread());
COMPLETE_ASYNC("natpmp::mapping_expired");
if (e) return;
#ifndef TORRENT_DISABLE_LOGGING
log("mapping %u expired", static_cast<int>(i));
#endif
m_mappings[i].act = portmap_action::add;
if (m_next_refresh == i) m_next_refresh = port_mapping_t{-1};
update_mapping(i);
}
void natpmp::close()
{
TORRENT_ASSERT(is_single_thread());
close_impl();
}
void natpmp::close_impl()
{
TORRENT_ASSERT(is_single_thread());
m_abort = true;
#ifndef TORRENT_DISABLE_LOGGING
log("closing");
#endif
if (m_disabled) return;
for (auto& m : m_mappings)
{
if (m.protocol == portmap_protocol::none) continue;
m.act = portmap_action::del;
}
error_code ec;
m_refresh_timer.cancel(ec);
m_currently_mapping = port_mapping_t{-1};
update_mapping(port_mapping_t{});
}
} // namespace libtorrent