premiere-libtorrent/src/udp_tracker_connection.cpp

618 lines
17 KiB
C++

/*
Copyright (c) 2003, 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>
#include "zlib.h"
#ifdef _MSC_VER
#pragma warning(push, 1)
#endif
#include <boost/bind.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"
using boost::bind;
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 const& ses
, proxy_settings const& proxy)
: tracker_connection(man, req, ios, c)
, m_man(man)
, m_name_lookup(ios)
, m_socket(ios, boost::bind(&udp_tracker_connection::on_receive, self(), _1, _2, _3, _4), cc)
, m_transaction_id(0)
, m_ses(ses)
, m_attempts(0)
, m_state(action_error)
{
TORRENT_ASSERT(refcount() == 1);
m_socket.set_proxy_settings(proxy);
}
void udp_tracker_connection::start()
{
std::string hostname;
int port;
error_code ec;
using boost::tuples::ignore;
boost::tie(ignore, ignore, hostname, port, ignore)
= parse_url_components(tracker_req().url, ec);
if (ec)
{
fail(ec);
return;
}
session_settings const& settings = m_ses.settings();
udp::resolver::query q(hostname, to_string(port).elems);
m_name_lookup.async_resolve(q
, boost::bind(
&udp_tracker_connection::name_lookup, self(), _1, _2));
set_timeout(tracker_req().event == tracker_request::stopped
? settings.stop_tracker_timeout
: settings.tracker_completion_timeout
, settings.tracker_receive_timeout);
#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: " + hostname + " ]").c_str());
#endif
}
void udp_tracker_connection::name_lookup(error_code const& error
, udp::resolver::iterator i)
{
if (error == asio::error::operation_aborted) return;
if (error || i == udp::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, udp::resolver::iterator(), std::back_inserter(m_endpoints)
, boost::bind(&udp::resolver::iterator::value_type::endpoint, _1));
// remove endpoints that are filtered by the IP filter
for (std::list<udp::endpoint>::iterator i = m_endpoints.begin();
i != m_endpoints.end();)
{
if (m_ses.m_ip_filter.access(i->address()) == ip_filter::blocked)
i = m_endpoints.erase(i);
else
++i;
}
if (m_endpoints.empty())
{
fail(error_code(errors::banned_by_ip_filter));
return;
}
std::list<udp::endpoint>::iterator iter = m_endpoints.begin();
m_target = *iter;
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(m_target.address().is_v4() != bind_interface().is_v4());
if (cb)
{
char const* tracker_address_type = m_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
{
m_target = *iter;
}
}
if (cb) cb->m_tracker_address = tcp::endpoint(m_target.address(), m_target.port());
error_code ec;
m_socket.bind(udp::endpoint(bind_interface(), 0), ec);
if (ec)
{
fail(ec);
return;
}
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()
{
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
boost::shared_ptr<request_callback> cb = requester();
char msg[200];
snprintf(msg, 200, "*** UDP_TRACKER [ timed out url: %s ]", tracker_req().url.c_str());
if (cb) cb->debug_log(msg);
#endif
m_socket.close();
m_name_lookup.cancel();
fail(error_code(errors::timed_out));
}
void udp_tracker_connection::close()
{
error_code ec;
m_socket.close();
m_name_lookup.cancel();
tracker_connection::close();
}
void 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;
if (!m_socket.is_open()) return; // the operation was aborted
// ignore packet not sent from the tracker
if (m_target != ep) return;
received_bytes(size + 28); // assuming UDP/IP header
if (e) fail(e);
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
boost::shared_ptr<request_callback> cb = requester();
if (cb)
{
char msg[200];
snprintf(msg, 200, "<== UDP_TRACKER_PACKET [ size: %d ]", size);
cb->debug_log(msg);
}
#endif
// ignore packets smaller than 8 bytes
if (size < 8) return;
restart_read_timeout();
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)
{
char msg[200];
snprintf(msg, 200, "*** UDP_TRACKER_PACKET [ action: %d ]", action);
cb->debug_log(msg);
}
#endif
// ignore packets with incorrect transaction id
if (m_transaction_id != transaction) return;
if (action == action_error)
{
fail(error_code(errors::tracker_failure), -1, std::string(ptr, size - 8).c_str());
return;
}
// ignore packets that's not a response to our message
if (action != m_state) return;
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb)
{
char msg[200];
snprintf(msg, 200, "*** UDP_TRACKER_RESPONSE [ tid: %x ]"
, int(transaction));
cb->debug_log(msg);
}
#endif
switch (m_state)
{
case action_connect:
on_connect_response(buf, size);
break;
case action_announce:
on_announce_response(buf, size);
break;
case action_scrape:
on_scrape_response(buf, size);
break;
default: break;
}
}
void udp_tracker_connection::on_connect_response(char const* buf, int size)
{
// ignore packets smaller than 16 bytes
if (size < 16) return;
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();
}
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);
char msg[200];
snprintf(msg, 200, "==> UDP_TRACKER_CONNECT [%s]", hex_ih);
cb->debug_log(msg);
}
#endif
if (!m_socket.is_open()) return; // the operation was aborted
char buf[16];
char* ptr = buf;
if (m_transaction_id == 0)
m_transaction_id = std::rand() ^ (std::rand() << 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;
m_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 = std::rand() ^ (std::rand() << 16);
if (!m_socket.is_open()) return; // the operation was aborted
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);
out += 20;
TORRENT_ASSERT(out - buf == sizeof(buf));
error_code ec;
m_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;
}
}
void udp_tracker_connection::on_announce_response(char const* buf, int size)
{
if (size < 20) return;
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;
}
boost::shared_ptr<request_callback> cb = requester();
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
if (cb)
{
boost::shared_ptr<request_callback> cb = requester();
char msg[200];
snprintf(msg, 200, "<== UDP_TRACKER_RESPONSE [ url: %s ]", tracker_req().url.c_str());
cb->debug_log(msg);
}
#endif
if (!cb)
{
m_man.remove_request(this);
return;
}
std::vector<peer_entry> peer_list;
for (int i = 0; i < num_peers; ++i)
{
// TODO: don't use a string here
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<udp::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, address());
m_man.remove_request(this);
close();
}
void udp_tracker_connection::on_scrape_response(char const* buf, int size)
{
buf += 8; // skip header
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;
}
if (action == action_error)
{
fail(error_code(errors::tracker_failure), -1, std::string(buf, size - 8).c_str());
return;
}
if (action != action_scrape)
{
fail(error_code(errors::invalid_tracker_action));
return;
}
if (size < 20)
{
fail(error_code(errors::invalid_tracker_response_length));
return;
}
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;
}
cb->tracker_scrape_response(tracker_req()
, complete, incomplete, downloaded);
m_man.remove_request(this);
close();
}
void udp_tracker_connection::send_udp_announce()
{
if (m_transaction_id == 0)
m_transaction_id = std::rand() ^ (std::rand() << 16);
if (!m_socket.is_open()) return; // the operation was aborted
char buf[8 + 4 + 4 + 20 + 20 + 8 + 8 + 8 + 4 + 4 + 4 + 4 + 2 + 2];
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 (!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
detail::write_uint16(0, out); // extensions
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);
char msg[200];
snprintf(msg, 200, "==> UDP_TRACKER_ANNOUNCE [%s]", hex_ih);
cb->debug_log(msg);
}
#endif
error_code ec;
m_socket.send(m_target, buf, sizeof(buf), ec);
m_state = action_announce;
sent_bytes(sizeof(buf) + 28); // assuming UDP/IP header
++m_attempts;
if (ec)
{
fail(ec);
return;
}
}
}