premiere-libtorrent/src/udp_tracker_connection.cpp

722 lines
20 KiB
C++

/*
Copyright (c) 2003-2014, 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"
#include <vector>
#include <cctype>
#ifdef _MSC_VER
#pragma warning(push, 1)
#endif
#include <boost/bind.hpp>
#include <boost/tuple/tuple.hpp>
#ifdef _MSC_VER
#pragma warning(pop)
#endif
#include "libtorrent/tracker_manager.hpp"
#include "libtorrent/parse_url.hpp"
#include "libtorrent/udp_tracker_connection.hpp"
#include "libtorrent/io.hpp"
#include "libtorrent/aux_/session_impl.hpp"
#include "libtorrent/escape_string.hpp"
#include "libtorrent/broadcast_socket.hpp" // for is_any
#include "libtorrent/random.hpp"
namespace libtorrent
{
std::map<address, udp_tracker_connection::connection_cache_entry>
udp_tracker_connection::m_connection_cache;
mutex udp_tracker_connection::m_cache_mutex;
udp_tracker_connection::udp_tracker_connection(
io_service& ios
, connection_queue& cc
, tracker_manager& man
, tracker_request const& req
, boost::weak_ptr<request_callback> c
, aux::session_impl& ses
, proxy_settings const& proxy)
: tracker_connection(man, req, ios, c)
, m_abort(false)
, m_transaction_id(0)
, m_ses(ses)
, m_attempts(0)
, m_state(action_error)
, m_proxy(proxy)
{
}
void udp_tracker_connection::start()
{
std::string hostname;
std::string protocol;
int port;
error_code ec;
using boost::tuples::ignore;
boost::tie(protocol, ignore, hostname, port, ignore)
= parse_url_components(tracker_req().url, ec);
if (port == -1) port = protocol == "http" ? 80 : 443;
if (ec)
{
tracker_connection::fail(ec);
return;
}
session_settings const& settings = m_ses.settings();
if (m_proxy.proxy_hostnames
&& (m_proxy.type == proxy_settings::socks5
|| m_proxy.type == proxy_settings::socks5_pw))
{
m_hostname = hostname;
m_target.port(port);
start_announce();
}
else
{
#if defined TORRENT_ASIO_DEBUGGING
add_outstanding_async("udp_tracker_connection::name_lookup");
#endif
tcp::resolver::query q(hostname, to_string(port).elems);
m_ses.m_host_resolver.async_resolve(q
, boost::bind(
&udp_tracker_connection::name_lookup, self(), _1, _2));
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb) cb->debug_log("*** UDP_TRACKER [ initiating name lookup: \"%s\" ]"
, hostname.c_str());
#endif
}
set_timeout(tracker_req().event == tracker_request::stopped
? settings.stop_tracker_timeout
: settings.tracker_completion_timeout
, settings.tracker_receive_timeout);
}
void udp_tracker_connection::fail(error_code const& ec, int code
, char const* msg, int interval, int min_interval)
{
// m_target failed. remove it from the endpoint list
std::list<tcp::endpoint>::iterator i = std::find(m_endpoints.begin()
, m_endpoints.end(), tcp::endpoint(m_target.address(), m_target.port()));
if (i != m_endpoints.end()) m_endpoints.erase(i);
// if that was the last one, fail the whole announce
if (m_endpoints.empty())
{
tracker_connection::fail(ec, code, msg, interval, min_interval);
return;
}
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb) cb->debug_log("*** UDP_TRACKER [ host: \"%s\" ip: \"%s\" | error: \"%s\" ]"
, m_hostname.c_str(), print_endpoint(m_target).c_str(), ec.message().c_str());
#endif
// pick another target endpoint and try again
m_target = pick_target_endpoint();
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb) cb->debug_log("*** UDP_TRACKER trying next IP [ host: \"%s\" ip: \"%s\" ]"
, m_hostname.c_str(), print_endpoint(m_target).c_str());
#endif
m_ses.m_io_service.post(boost::bind(
&udp_tracker_connection::start_announce, self()));
}
void udp_tracker_connection::name_lookup(error_code const& error
, tcp::resolver::iterator i)
{
#if defined TORRENT_ASIO_DEBUGGING
complete_async("udp_tracker_connection::name_lookup");
#endif
if (m_abort) return;
if (error == asio::error::operation_aborted) return;
if (error || i == tcp::resolver::iterator())
{
fail(error);
return;
}
boost::shared_ptr<request_callback> cb = requester();
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb) cb->debug_log("*** UDP_TRACKER [ name lookup successful ]");
#endif
if (cancelled())
{
fail(error_code(errors::torrent_aborted));
return;
}
restart_read_timeout();
// look for an address that has the same kind as the one
// we're listening on. To make sure the tracker get our
// correct listening address.
std::transform(i, tcp::resolver::iterator(), std::back_inserter(m_endpoints)
, boost::bind(&tcp::resolver::iterator::value_type::endpoint, _1));
if (tracker_req().apply_ip_filter)
{
// remove endpoints that are filtered by the IP filter
for (std::list<tcp::endpoint>::iterator k = m_endpoints.begin();
k != m_endpoints.end();)
{
if (m_ses.m_ip_filter.access(k->address()) == ip_filter::blocked)
{
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb) cb->debug_log("*** UDP_TRACKER [ IP blocked by filter: %s ]"
, print_address(k->address()).c_str());
#endif
k = m_endpoints.erase(k);
}
else
++k;
}
}
// if all endpoints were filtered by the IP filter, we can't connect
if (m_endpoints.empty())
{
fail(error_code(errors::banned_by_ip_filter));
return;
}
m_target = pick_target_endpoint();
if (cb) cb->m_tracker_address = tcp::endpoint(m_target.address(), m_target.port());
start_announce();
}
udp::endpoint udp_tracker_connection::pick_target_endpoint() const
{
std::list<tcp::endpoint>::const_iterator iter = m_endpoints.begin();
udp::endpoint target = udp::endpoint(iter->address(), iter->port());
if (bind_interface() != address_v4::any())
{
// find first endpoint that matches our bind interface type
for (; iter != m_endpoints.end() && iter->address().is_v4()
!= bind_interface().is_v4(); ++iter);
if (iter == m_endpoints.end())
{
TORRENT_ASSERT(target.address().is_v4() != bind_interface().is_v4());
boost::shared_ptr<request_callback> cb = requester();
if (cb)
{
char const* tracker_address_type = target.address().is_v4() ? "IPv4" : "IPv6";
char const* bind_address_type = bind_interface().is_v4() ? "IPv4" : "IPv6";
char msg[200];
snprintf(msg, sizeof(msg)
, "the tracker only resolves to an %s address, and you're "
"listening on an %s socket. This may prevent you from receiving "
"incoming connections."
, tracker_address_type, bind_address_type);
cb->tracker_warning(tracker_req(), msg);
}
}
else
{
target = udp::endpoint(iter->address(), iter->port());
}
}
return target;
}
void udp_tracker_connection::start_announce()
{
mutex::scoped_lock l(m_cache_mutex);
std::map<address, connection_cache_entry>::iterator cc
= m_connection_cache.find(m_target.address());
if (cc != m_connection_cache.end())
{
// we found a cached entry! Now, we can only
// use if if it hasn't expired
if (time_now() < cc->second.expires)
{
if (tracker_req().kind == tracker_request::announce_request)
send_udp_announce();
else if (tracker_req().kind == tracker_request::scrape_request)
send_udp_scrape();
return;
}
// if it expired, remove it from the cache
m_connection_cache.erase(cc);
}
l.unlock();
send_udp_connect();
}
void udp_tracker_connection::on_timeout(error_code const& ec)
{
if (ec)
{
fail(ec);
return;
}
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb) cb->debug_log("*** UDP_TRACKER [ timed out url: %s ]", tracker_req().url.c_str());
#endif
m_abort = true;
fail(error_code(errors::timed_out));
}
void udp_tracker_connection::close()
{
error_code ec;
tracker_connection::close();
}
bool udp_tracker_connection::on_receive_hostname(error_code const& e
, char const* hostname, char const* buf, int size)
{
// just ignore the hostname this came from, pretend that
// it's from the same endpoint we sent it to (i.e. the same
// port). We have so many other ways of confirming this packet
// comes from the tracker anyway, so it's not a big deal
return on_receive(e, m_target, buf, size);
}
bool udp_tracker_connection::on_receive(error_code const& e
, udp::endpoint const& ep, char const* buf, int size)
{
// ignore resposes before we've sent any requests
if (m_state == action_error) return false;
if (m_abort) return false;
// ignore packet not sent from the tracker
// if m_target is inaddr_any, it suggests that we
// sent the packet through a proxy only knowing
// the hostname, in which case this packet might be for us
if (!is_any(m_target.address()) && m_target != ep) return false;
if (e) fail(e);
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb)
{
cb->debug_log("<== UDP_TRACKER_PACKET [ size: %d ]", size);
}
#endif
// ignore packets smaller than 8 bytes
if (size < 8) return false;
const char* ptr = buf;
int action = detail::read_int32(ptr);
int transaction = detail::read_int32(ptr);
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb)
{
cb->debug_log("*** UDP_TRACKER_PACKET [ action: %d ]", action);
}
#endif
// ignore packets with incorrect transaction id
if (m_transaction_id != transaction) return false;
if (action == action_error)
{
fail(error_code(errors::tracker_failure), -1, std::string(ptr, size - 8).c_str());
return true;
}
// ignore packets that's not a response to our message
if (action != m_state) return false;
restart_read_timeout();
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb)
{
cb->debug_log("*** UDP_TRACKER_RESPONSE [ tid: %x ]"
, int(transaction));
}
#endif
switch (m_state)
{
case action_connect:
return on_connect_response(buf, size);
case action_announce:
return on_announce_response(buf, size);
case action_scrape:
return on_scrape_response(buf, size);
default: break;
}
return false;
}
bool udp_tracker_connection::on_connect_response(char const* buf, int size)
{
// ignore packets smaller than 16 bytes
if (size < 16) return false;
restart_read_timeout();
buf += 8; // skip header
// reset transaction
m_transaction_id = 0;
m_attempts = 0;
boost::uint64_t connection_id = detail::read_int64(buf);
mutex::scoped_lock l(m_cache_mutex);
connection_cache_entry& cce = m_connection_cache[m_target.address()];
cce.connection_id = connection_id;
cce.expires = time_now() + seconds(m_ses.m_settings.udp_tracker_token_expiry);
if (tracker_req().kind == tracker_request::announce_request)
send_udp_announce();
else if (tracker_req().kind == tracker_request::scrape_request)
send_udp_scrape();
return true;
}
void udp_tracker_connection::send_udp_connect()
{
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb)
{
char hex_ih[41];
to_hex((char const*)&tracker_req().info_hash[0], 20, hex_ih);
cb->debug_log("==> UDP_TRACKER_CONNECT [%s]", hex_ih);
}
#endif
if (m_abort) return;
char buf[16];
char* ptr = buf;
if (m_transaction_id == 0)
m_transaction_id = random() ^ (random() << 16);
detail::write_uint32(0x417, ptr);
detail::write_uint32(0x27101980, ptr); // connection_id
detail::write_int32(action_connect, ptr); // action (connect)
detail::write_int32(m_transaction_id, ptr); // transaction_id
TORRENT_ASSERT(ptr - buf == sizeof(buf));
error_code ec;
if (!m_hostname.empty())
{
m_ses.m_udp_socket.send_hostname(m_hostname.c_str(), m_target.port(), buf, 16, ec);
}
else
{
m_ses.m_udp_socket.send(m_target, buf, 16, ec);
}
m_state = action_connect;
sent_bytes(16 + 28); // assuming UDP/IP header
++m_attempts;
if (ec)
{
fail(ec);
return;
}
}
void udp_tracker_connection::send_udp_scrape()
{
if (m_transaction_id == 0)
m_transaction_id = random() ^ (random() << 16);
if (m_abort) return;
std::map<address, connection_cache_entry>::iterator i
= m_connection_cache.find(m_target.address());
// this isn't really supposed to happen
TORRENT_ASSERT(i != m_connection_cache.end());
if (i == m_connection_cache.end()) return;
char buf[8 + 4 + 4 + 20];
char* out = buf;
detail::write_int64(i->second.connection_id, out); // connection_id
detail::write_int32(action_scrape, out); // action (scrape)
detail::write_int32(m_transaction_id, out); // transaction_id
// info_hash
std::copy(tracker_req().info_hash.begin(), tracker_req().info_hash.end(), out);
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
out += 20;
TORRENT_ASSERT(out - buf == sizeof(buf));
#endif
error_code ec;
if (!m_hostname.empty())
{
m_ses.m_udp_socket.send_hostname(m_hostname.c_str(), m_target.port(), buf, sizeof(buf), ec);
}
else
{
m_ses.m_udp_socket.send(m_target, buf, sizeof(buf), ec);
}
m_state = action_scrape;
sent_bytes(sizeof(buf) + 28); // assuming UDP/IP header
++m_attempts;
if (ec)
{
fail(ec);
return;
}
}
bool udp_tracker_connection::on_announce_response(char const* buf, int size)
{
if (size < 20) return false;
buf += 8; // skip header
restart_read_timeout();
int interval = detail::read_int32(buf);
int min_interval = 60;
int incomplete = detail::read_int32(buf);
int complete = detail::read_int32(buf);
int num_peers = (size - 20) / 6;
if ((size - 20) % 6 != 0)
{
fail(error_code(errors::invalid_tracker_response_length));
return false;
}
boost::shared_ptr<request_callback> cb = requester();
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb)
{
boost::shared_ptr<request_callback> cb = requester();
cb->debug_log("<== UDP_TRACKER_RESPONSE [ url: %s ]", tracker_req().url.c_str());
}
#endif
if (!cb)
{
close();
return true;
}
std::vector<peer_entry> peer_list;
for (int i = 0; i < num_peers; ++i)
{
// TODO: it would be more efficient to not use a string here.
// however, the problem is that some trackers will respond
// with actual strings. For example i2p trackers
peer_entry e;
char ip_string[100];
unsigned int a = detail::read_uint8(buf);
unsigned int b = detail::read_uint8(buf);
unsigned int c = detail::read_uint8(buf);
unsigned int d = detail::read_uint8(buf);
snprintf(ip_string, 100, "%u.%u.%u.%u", a, b, c, d);
e.ip = ip_string;
e.port = detail::read_uint16(buf);
e.pid.clear();
peer_list.push_back(e);
}
std::list<address> ip_list;
for (std::list<tcp::endpoint>::const_iterator i = m_endpoints.begin()
, end(m_endpoints.end()); i != end; ++i)
{
ip_list.push_back(i->address());
}
cb->tracker_response(tracker_req(), m_target.address(), ip_list
, peer_list, interval, min_interval, complete, incomplete, 0, address(), "" /*trackerid*/);
close();
return true;
}
bool udp_tracker_connection::on_scrape_response(char const* buf, int size)
{
restart_read_timeout();
int action = detail::read_int32(buf);
int transaction = detail::read_int32(buf);
if (transaction != m_transaction_id)
{
fail(error_code(errors::invalid_tracker_transaction_id));
return false;
}
if (action == action_error)
{
fail(error_code(errors::tracker_failure), -1, std::string(buf, size - 8).c_str());
return true;
}
if (action != action_scrape)
{
fail(error_code(errors::invalid_tracker_action));
return true;
}
if (size < 20)
{
fail(error_code(errors::invalid_tracker_response_length));
return true;
}
int complete = detail::read_int32(buf);
int downloaded = detail::read_int32(buf);
int incomplete = detail::read_int32(buf);
boost::shared_ptr<request_callback> cb = requester();
if (!cb)
{
close();
return true;
}
cb->tracker_scrape_response(tracker_req()
, complete, incomplete, downloaded, -1);
close();
return true;
}
void udp_tracker_connection::send_udp_announce()
{
if (m_transaction_id == 0)
m_transaction_id = random() ^ (random() << 16);
if (m_abort) return;
char buf[800];
char* out = buf;
tracker_request const& req = tracker_req();
const bool stats = req.send_stats;
session_settings const& settings = m_ses.settings();
std::map<address, connection_cache_entry>::iterator i
= m_connection_cache.find(m_target.address());
// this isn't really supposed to happen
TORRENT_ASSERT(i != m_connection_cache.end());
if (i == m_connection_cache.end()) return;
detail::write_int64(i->second.connection_id, out); // connection_id
detail::write_int32(action_announce, out); // action (announce)
detail::write_int32(m_transaction_id, out); // transaction_id
std::copy(req.info_hash.begin(), req.info_hash.end(), out); // info_hash
out += 20;
std::copy(req.pid.begin(), req.pid.end(), out); // peer_id
out += 20;
detail::write_int64(stats ? req.downloaded : 0, out); // downloaded
detail::write_int64(stats ? req.left : 0, out); // left
detail::write_int64(stats ? req.uploaded : 0, out); // uploaded
detail::write_int32(req.event, out); // event
// ip address
address_v4 announce_ip;
if (!m_ses.settings().anonymous_mode
&& !settings.announce_ip.empty())
{
error_code ec;
address ip = address::from_string(settings.announce_ip.c_str(), ec);
if (!ec && ip.is_v4()) announce_ip = ip.to_v4();
}
detail::write_uint32(announce_ip.to_ulong(), out);
detail::write_int32(req.key, out); // key
detail::write_int32(req.num_want, out); // num_want
detail::write_uint16(req.listen_port, out); // port
std::string request_string;
error_code ec;
using boost::tuples::ignore;
boost::tie(ignore, ignore, ignore, ignore, request_string) = parse_url_components(req.url, ec);
if (ec) request_string.clear();
if (!request_string.empty())
{
int str_len = (std::min)(int(request_string.size()), 255);
request_string.resize(str_len);
detail::write_uint8(2, out);
detail::write_uint8(str_len, out);
detail::write_string(request_string, out);
}
TORRENT_ASSERT(out - buf <= sizeof(buf));
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb)
{
char hex_ih[41];
to_hex((char const*)&req.info_hash[0], 20, hex_ih);
cb->debug_log("==> UDP_TRACKER_ANNOUNCE [%s]", hex_ih);
}
#endif
if (!m_hostname.empty())
{
m_ses.m_udp_socket.send_hostname(m_hostname.c_str(), m_target.port(), buf, out - buf, ec);
}
else
{
m_ses.m_udp_socket.send(m_target, buf, out - buf, ec);
}
m_state = action_announce;
sent_bytes(out - buf + 28); // assuming UDP/IP header
++m_attempts;
if (ec)
{
fail(ec);
return;
}
}
}