bool udp_tracker_connection::on_connect_response(aux::array_view<char const> buf)
{
// ignore packets smaller than 16 bytes
if (buf.size() < 16) return false;
restart_read_timeout();
// skip header
buf = buf.cut_first(8);
// reset transaction
update_transaction_id();
std::uint64_t const connection_id = read_int64(buf);
std::lock_guard<std::mutex> l(m_cache_mutex);
connection_cache_entry& cce = m_connection_cache[m_target.address()];
cce.connection_id = connection_id;
cce.expires = aux::time_now() + seconds(m_man.settings().get_int(settings_pack::udp_tracker_token_expiry));
if (0 == (tracker_req().kind & tracker_request::scrape_request))
send_udp_announce();
else if (0 != (tracker_req().kind & tracker_request::scrape_request))
send_udp_scrape();
return true;
}
// allocate an uninitialized buffer of the specified size
// and copy the initialization range into the start of the buffer
buffer(std::size_t const size, aux::array_view<char const> initialize)
: buffer(size)
{
TORRENT_ASSERT(initialize.size() <= size);
if (initialize.size() > 0)
{
memcpy(m_begin, initialize.data(), std::min(initialize.size(), size));
}
}
bool udp_tracker_connection::on_scrape_response(aux::array_view<char const> buf)
{
using namespace libtorrent::aux;
restart_read_timeout();
int const action = aux::read_int32(buf);
std::uint32_t const transaction = read_uint32(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.data(), buf.size()).c_str());
return true;
}
if (action != action_scrape)
{
fail(error_code(errors::invalid_tracker_action));
return true;
}
if (buf.size() < 12)
{
fail(error_code(errors::invalid_tracker_response_length));
return true;
}
int const complete = aux::read_int32(buf);
int const downloaded = aux::read_int32(buf);
int const incomplete = aux::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;
}
bool udp_tracker_connection::on_announce_response(aux::array_view<char const> buf)
{
if (buf.size() < 20) return false;
buf = buf.cut_first(8);
restart_read_timeout();
tracker_response resp;
resp.interval = aux::read_int32(buf);
resp.min_interval = 60;
resp.incomplete = aux::read_int32(buf);
resp.complete = aux::read_int32(buf);
int const num_peers = int(buf.size()) / 6;
if ((buf.size() % 6) != 0)
{
fail(error_code(errors::invalid_tracker_response_length));
return false;
}
boost::shared_ptr<request_callback> cb = requester();
#ifndef TORRENT_DISABLE_LOGGING
if (cb)
{
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;
resp.peers4.reserve(num_peers);
for (int i = 0; i < num_peers; ++i)
{
ipv4_peer_entry e;
memcpy(&e.ip[0], buf.data(), 4);
buf = buf.cut_first(4);
e.port = aux::read_uint16(buf);
resp.peers4.push_back(e);
}
std::list<address> ip_list;
for (std::vector<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
, resp);
close();
return true;
}
bool udp_tracker_connection::on_receive(udp::endpoint const& ep
, aux::array_view<char const> const buf)
{
#ifndef TORRENT_DISABLE_LOGGING
boost::shared_ptr<request_callback> cb = requester();
#endif
// ignore resposes before we've sent any requests
if (m_state == action_error)
{
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("<== UDP_TRACKER [ m_action == error ]");
#endif
return false;
}
if (m_abort)
{
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("<== UDP_TRACKER [ aborted]");
#endif
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)
{
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("<== UDP_TRACKER [ unexpected source IP: %s "
"expected: %s ]"
, print_endpoint(ep).c_str()
, print_endpoint(m_target).c_str());
#endif
return false;
}
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("<== UDP_TRACKER_PACKET [ size: %d ]"
, int(buf.size()));
#endif
// ignore packets smaller than 8 bytes
if (buf.size() < 8) return false;
aux::array_view<const char> ptr = buf;
int const action = read_int32(ptr);
std::uint32_t const transaction = read_uint32(ptr);
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("*** UDP_TRACKER_PACKET [ action: %d ]", action);
#endif
// ignore packets with incorrect transaction id
if (m_transaction_id != transaction)
{
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("*** UDP_TRACKER_PACKET [ tid: %x ]"
, int(transaction));
#endif
return false;
}
if (action == action_error)
{
fail(error_code(errors::tracker_failure), -1
, std::string(buf.data(), buf.size()).c_str());
return true;
}
// ignore packets that's not a response to our message
if (action != m_state)
{
#ifndef TORRENT_DISABLE_LOGGING
if (cb) cb->debug_log("*** UDP_TRACKER_PACKET [ unexpected action: %d "
" expected: %d ]", action, m_state);
#endif
return false;
}
restart_read_timeout();
#ifndef TORRENT_DISABLE_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);
case action_announce:
return on_announce_response(buf);
case action_scrape:
return on_scrape_response(buf);
default: break;
}
return false;
}
bool utp_socket_manager::incoming_packet(udp::endpoint const& ep
, aux::array_view<char const> p)
{
// UTP_LOGV("incoming packet size:%d\n", size);
if (p.size() < int(sizeof(utp_header))) return false;
utp_header const* ph = reinterpret_cast<utp_header const*>(p.data());
// UTP_LOGV("incoming packet version:%d\n", int(ph->get_version()));
if (ph->get_version() != 1) return false;
const time_point receive_time = clock_type::now();
// parse out connection ID and look for existing
// connections. If found, forward to the utp_stream.
std::uint16_t id = ph->connection_id;
// first test to see if it's the same socket as last time
// in most cases it is
if (m_last_socket
&& utp_match(m_last_socket, ep, id))
{
return utp_incoming_packet(m_last_socket, p, ep, receive_time);
}
std::pair<socket_map_t::iterator, socket_map_t::iterator> r =
m_utp_sockets.equal_range(id);
for (; r.first != r.second; ++r.first)
{
if (!utp_match(r.first->second, ep, id)) continue;
bool ret = utp_incoming_packet(r.first->second, p, ep, receive_time);
if (ret) m_last_socket = r.first->second;
return ret;
}
// UTP_LOGV("incoming packet id:%d source:%s\n", id, print_endpoint(ep).c_str());
if (!m_sett.get_bool(settings_pack::enable_incoming_utp))
return false;
// if not found, see if it's a SYN packet, if it is,
// create a new utp_stream
if (ph->get_type() == ST_SYN)
{
// possible SYN flood. Just ignore
if (int(m_utp_sockets.size()) > m_sett.get_int(settings_pack::connections_limit) * 2)
return false;
// UTP_LOGV("not found, new connection id:%d\n", m_new_connection);
boost::shared_ptr<socket_type> c(new (std::nothrow) socket_type(m_ios));
if (!c) return false;
TORRENT_ASSERT(m_new_connection == -1);
// create the new socket with this ID
m_new_connection = id;
instantiate_connection(m_ios, aux::proxy_settings(), *c
, m_ssl_context, this, true, false);
utp_stream* str = nullptr;
#ifdef TORRENT_USE_OPENSSL
if (is_ssl(*c))
str = &c->get<ssl_stream<utp_stream> >()->next_layer();
else
#endif
str = c->get<utp_stream>();
TORRENT_ASSERT(str);
int link_mtu, utp_mtu;
mtu_for_dest(ep.address(), link_mtu, utp_mtu);
utp_init_mtu(str->get_impl(), link_mtu, utp_mtu);
bool ret = utp_incoming_packet(str->get_impl(), p, ep, receive_time);
if (!ret) return false;
m_cb(c);
// the connection most likely changed its connection ID here
// we need to move it to the correct ID
return true;
}
if (ph->get_type() == ST_RESET) return false;
// #error send reset
return false;
}