/* 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/assert.hpp" // for print_backtrace #include "libtorrent/socket.hpp" #include "libtorrent/udp_socket.hpp" #include "libtorrent/socket_io.hpp" #include "libtorrent/error.hpp" #include "libtorrent/string_util.hpp" // for allocate_string_copy #include "libtorrent/broadcast_socket.hpp" // for is_any #include "libtorrent/settings_pack.hpp" #include "libtorrent/error.hpp" #include "libtorrent/aux_/time.hpp" // for aux::time_now() #include #include #include #include #include #include #include #if defined TORRENT_ASIO_DEBUGGING #include "libtorrent/debug.hpp" #endif using namespace libtorrent; udp_socket::udp_socket(io_service& ios) : m_observers_locked(false) , m_ipv4_sock(ios) , m_timer(ios) , m_buf_size(0) , m_new_buf_size(0) , m_buf(0) #if TORRENT_USE_IPV6 , m_ipv6_sock(ios) #endif , m_bind_port(0) , m_v4_outstanding(0) , m_restart_v4(0) #if TORRENT_USE_IPV6 , m_v6_outstanding(0) , m_restart_v6(false) #endif , m_socks5_sock(ios) , m_resolver(ios) , m_queue_packets(false) , m_tunnel_packets(false) , m_force_proxy(false) , m_abort(true) , m_outstanding_ops(0) #if TORRENT_USE_IPV6 , m_v6_write_subscribed(false) #endif , m_v4_write_subscribed(false) { #if TORRENT_USE_ASSERTS m_magic = 0x1337; m_started = false; m_outstanding_when_aborted = -1; m_outstanding_connect = 0; m_outstanding_timeout = 0; m_outstanding_resolve = 0; m_outstanding_socks = 0; #endif m_buf_size = 2048; m_new_buf_size = m_buf_size; m_buf = static_cast(malloc(m_buf_size)); } udp_socket::~udp_socket() { free(m_buf); #if TORRENT_USE_IPV6 TORRENT_ASSERT_VAL(m_v6_outstanding == 0, m_v6_outstanding); #endif TORRENT_ASSERT_VAL(m_v4_outstanding == 0, m_v4_outstanding); TORRENT_ASSERT(m_magic == 0x1337); TORRENT_ASSERT(m_observers_locked == false); #if TORRENT_USE_ASSERTS m_magic = 0; #endif TORRENT_ASSERT(m_outstanding_ops == 0); } #if TORRENT_USE_ASSERTS #define CHECK_MAGIC check_magic_ cm_(m_magic) struct check_magic_ { check_magic_(int& m_): m(m_) { TORRENT_ASSERT(m == 0x1337); } ~check_magic_() { TORRENT_ASSERT(m == 0x1337); } int& m; }; #else #define CHECK_MAGIC do {} TORRENT_WHILE_0 #endif void udp_socket::send_hostname(char const* hostname, int port , char const* p, int len, error_code& ec, int flags) { CHECK_MAGIC; TORRENT_ASSERT(is_single_thread()); // if the sockets are closed, the udp_socket is closing too if (!is_open()) { ec = error_code(boost::system::errc::bad_file_descriptor, generic_category()); return; } if (m_tunnel_packets) { // send udp packets through SOCKS5 server wrap(hostname, port, p, len, ec); return; } // this function is only supported when we're using a proxy if (!m_queue_packets && !m_force_proxy) { address target = address::from_string(hostname, ec); if (!ec) send(udp::endpoint(target, port), p, len, ec, 0); return; } if (m_queue.size() > 1000 || (flags & dont_queue)) return; m_queue.push_back(queued_packet()); queued_packet& qp = m_queue.back(); qp.ep.port(port); address target = address::from_string(hostname, ec); if (ec) qp.ep.address(target); else qp.hostname = allocate_string_copy(hostname); qp.buf.insert(qp.buf.begin(), p, p + len); qp.flags = 0; } void udp_socket::send(udp::endpoint const& ep, char const* p, int len , error_code& ec, int flags) { CHECK_MAGIC; TORRENT_ASSERT(is_single_thread()); // if the sockets are closed, the udp_socket is closing too if (!is_open()) { ec = error_code(boost::system::errc::bad_file_descriptor, generic_category()); return; } const bool allow_proxy = ((flags & peer_connection) && m_proxy_settings.proxy_peer_connections) || ((flags & tracker_connection) && m_proxy_settings.proxy_tracker_connections) || (flags & (tracker_connection | peer_connection)) == 0 ; if (allow_proxy) { if (m_tunnel_packets) { // send udp packets through SOCKS5 server wrap(ep, p, len, ec); return; } if (m_queue_packets) { if (m_queue.size() > 1000 || (flags & dont_queue)) return; m_queue.push_back(queued_packet()); queued_packet& qp = m_queue.back(); qp.ep = ep; qp.hostname = 0; qp.flags = flags; qp.buf.insert(qp.buf.begin(), p, p + len); return; } } if (m_force_proxy) return; #if TORRENT_USE_IPV6 if (ep.address().is_v6() && m_ipv6_sock.is_open()) m_ipv6_sock.send_to(boost::asio::buffer(p, len), ep, 0, ec); else #endif m_ipv4_sock.send_to(boost::asio::buffer(p, len), ep, 0, ec); if (ec == error::would_block || ec == error::try_again) { #if TORRENT_USE_IPV6 if (ep.address().is_v6() && m_ipv6_sock.is_open()) { if (!m_v6_write_subscribed) { m_ipv6_sock.async_send(null_buffers() , boost::bind(&udp_socket::on_writable, this, _1, &m_ipv6_sock)); m_v6_write_subscribed = true; } } else #endif { if (!m_v4_write_subscribed) { m_ipv4_sock.async_send(null_buffers() , boost::bind(&udp_socket::on_writable, this, _1, &m_ipv4_sock)); m_v4_write_subscribed = true; } } } } void udp_socket::on_writable(error_code const& ec, udp::socket* s) { #if TORRENT_USE_IPV6 if (s == &m_ipv6_sock) m_v6_write_subscribed = false; else #else TORRENT_UNUSED(s); #endif m_v4_write_subscribed = false; if (ec == boost::asio::error::operation_aborted) return; call_writable_handler(); } // called whenever the socket is readable void udp_socket::on_read(error_code const& ec, udp::socket* s) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_read"); #endif TORRENT_ASSERT(m_magic == 0x1337); TORRENT_ASSERT(is_single_thread()); #if TORRENT_USE_IPV6 if (s == &m_ipv6_sock) { TORRENT_ASSERT(m_v6_outstanding > 0); --m_v6_outstanding; } else #else TORRENT_UNUSED(s); #endif { TORRENT_ASSERT(m_v4_outstanding > 0); --m_v4_outstanding; } if (ec == boost::asio::error::operation_aborted) { #if TORRENT_USE_IPV6 if (s == &m_ipv6_sock) { if (m_restart_v6) { --m_restart_v6; setup_read(s); } } else #endif { if (m_restart_v4) { --m_restart_v4; setup_read(s); } } return; } if (m_abort) { close_impl(); return; } CHECK_MAGIC; for (;;) { error_code err; udp::endpoint ep; size_t bytes_transferred = s->receive_from(boost::asio::buffer(m_buf, m_buf_size), ep, 0, err); // TODO: it would be nice to detect this on posix systems also #ifdef TORRENT_WINDOWS if ((err == error_code(ERROR_MORE_DATA, system_category()) || err == error_code(WSAEMSGSIZE, system_category())) && m_buf_size < 65536) { // if this function fails to allocate memory, m_buf_size // is set to 0. In that case, don't issue the async_read(). set_buf_size(m_buf_size * 2); if (m_buf_size == 0) return; continue; } #endif if (err == boost::asio::error::would_block || err == boost::asio::error::try_again) break; on_read_impl(ep, err, bytes_transferred); // found on iOS, socket will be disconnected when app goes backgroud. try to reopen it. if (err == boost::asio::error::not_connected || err == boost::asio::error::bad_descriptor) { ep = s->local_endpoint(err); if (!err) { bind(ep, err); } return; } } call_drained_handler(); setup_read(s); } void udp_socket::call_handler(error_code const& ec, udp::endpoint const& ep, char const* buf, int size) { m_observers_locked = true; for (std::vector::iterator i = m_observers.begin(); i != m_observers.end();) { bool ret = false; TORRENT_TRY { ret = (*i)->incoming_packet(ec, ep, buf, size); } TORRENT_CATCH (std::exception&) {} if (*i == NULL) i = m_observers.erase(i); else ++i; if (ret) break; } if (!m_added_observers.empty()) { m_observers.insert(m_observers.end(), m_added_observers.begin(), m_added_observers.end()); m_added_observers.clear(); } m_observers_locked = false; if (m_new_buf_size != m_buf_size) set_buf_size(m_new_buf_size); } void udp_socket::call_handler(error_code const& ec, const char* host, char const* buf, int size) { m_observers_locked = true; for (std::vector::iterator i = m_observers.begin(); i != m_observers.end();) { bool ret = false; TORRENT_TRY { ret = (*i)->incoming_packet(ec, host, buf, size); } TORRENT_CATCH (std::exception&) {} if (*i == NULL) i = m_observers.erase(i); else ++i; if (ret) break; } if (!m_added_observers.empty()) { m_observers.insert(m_observers.end(), m_added_observers.begin(), m_added_observers.end()); m_added_observers.clear(); } m_observers_locked = false; if (m_new_buf_size != m_buf_size) set_buf_size(m_new_buf_size); } void udp_socket::call_drained_handler() { m_observers_locked = true; for (std::vector::iterator i = m_observers.begin(); i != m_observers.end();) { TORRENT_TRY { (*i)->socket_drained(); } TORRENT_CATCH (std::exception&) {} if (*i == NULL) i = m_observers.erase(i); else ++i; } if (!m_added_observers.empty()) { m_observers.insert(m_observers.end(), m_added_observers.begin(), m_added_observers.end()); m_added_observers.clear(); } m_observers_locked = false; if (m_new_buf_size != m_buf_size) set_buf_size(m_new_buf_size); } void udp_socket::call_writable_handler() { m_observers_locked = true; for (std::vector::iterator i = m_observers.begin(); i != m_observers.end();) { TORRENT_TRY { (*i)->writable(); } TORRENT_CATCH (std::exception&) {} if (*i == NULL) i = m_observers.erase(i); else ++i; } if (!m_added_observers.empty()) { m_observers.insert(m_observers.end(), m_added_observers.begin(), m_added_observers.end()); m_added_observers.clear(); } m_observers_locked = false; if (m_new_buf_size != m_buf_size) set_buf_size(m_new_buf_size); } void udp_socket::subscribe(udp_socket_observer* o) { TORRENT_ASSERT(std::find(m_observers.begin(), m_observers.end(), o) == m_observers.end()); if (m_observers_locked) m_added_observers.push_back(o); else m_observers.push_back(o); } void udp_socket::unsubscribe(udp_socket_observer* o) { std::vector::iterator i = std::find(m_observers.begin(), m_observers.end(), o); if (i == m_observers.end()) return; if (m_observers_locked) *i = NULL; else m_observers.erase(i); } void udp_socket::on_read_impl(udp::endpoint const& ep , error_code const& e, std::size_t bytes_transferred) { TORRENT_ASSERT(m_magic == 0x1337); TORRENT_ASSERT(is_single_thread()); if (e) { call_handler(e, ep, 0, 0); // don't stop listening on recoverable errors if (e != boost::asio::error::host_unreachable && e != boost::asio::error::fault && e != boost::asio::error::connection_reset && e != boost::asio::error::connection_refused && e != boost::asio::error::connection_aborted && e != boost::asio::error::operation_aborted && e != boost::asio::error::network_reset && e != boost::asio::error::network_unreachable #ifdef _WIN32 // ERROR_MORE_DATA means the same thing as EMSGSIZE && e != error_code(ERROR_MORE_DATA, system_category()) && e != error_code(ERROR_HOST_UNREACHABLE, system_category()) && e != error_code(ERROR_PORT_UNREACHABLE, system_category()) && e != error_code(ERROR_RETRY, system_category()) && e != error_code(ERROR_NETWORK_UNREACHABLE, system_category()) && e != error_code(ERROR_CONNECTION_REFUSED, system_category()) && e != error_code(ERROR_CONNECTION_ABORTED, system_category()) #endif && e != boost::asio::error::message_size) { return; } if (m_abort) { close_impl(); return; } return; } TORRENT_TRY { if (m_tunnel_packets) { // if the source IP doesn't match the proxy's, ignore the packet if (ep == m_udp_proxy_addr) unwrap(e, m_buf, bytes_transferred); } else if (!m_force_proxy) // block incoming packets that aren't coming via the proxy { call_handler(e, ep, m_buf, bytes_transferred); } } TORRENT_CATCH (std::exception&) {} } void udp_socket::setup_read(udp::socket* s) { if (m_abort) { close_impl(); return; } #if TORRENT_USE_IPV6 if (s == &m_ipv6_sock) { if (m_v6_outstanding) { ++m_restart_v6; m_ipv6_sock.cancel(); return; } ++m_v6_outstanding; } else #endif { if (m_v4_outstanding) { ++m_restart_v4; m_ipv4_sock.cancel(); return; } ++m_v4_outstanding; } #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_read"); #endif udp::endpoint ep; TORRENT_TRY { #if TORRENT_USE_IPV6 if (s == &m_ipv6_sock) { s->async_receive_from(null_buffers() , ep, make_read_handler6(boost::bind(&udp_socket::on_read, this, _1, s))); } else #endif { s->async_receive_from(null_buffers() , ep, make_read_handler4(boost::bind(&udp_socket::on_read, this, _1, s))); } } TORRENT_CATCH(boost::system::system_error& e) { #ifdef BOOST_NO_EXCEPTIONS // dummy error_code ec; boost::system::system_error e(ec); #endif get_io_service().post(boost::bind(&udp_socket::on_read , this, e.code(), s)); } } void udp_socket::wrap(udp::endpoint const& ep, char const* p, int len, error_code& ec) { CHECK_MAGIC; using namespace libtorrent::detail; char header[25]; char* h = header; write_uint16(0, h); // reserved write_uint8(0, h); // fragment write_uint8(ep.address().is_v4()?1:4, h); // atyp write_endpoint(ep, h); boost::array iovec; iovec[0] = boost::asio::const_buffer(header, h - header); iovec[1] = boost::asio::const_buffer(p, len); #if TORRENT_USE_IPV6 if (m_udp_proxy_addr.address().is_v4() && m_ipv4_sock.is_open()) #endif m_ipv4_sock.send_to(iovec, m_udp_proxy_addr, 0, ec); #if TORRENT_USE_IPV6 else m_ipv6_sock.send_to(iovec, m_udp_proxy_addr, 0, ec); #endif } void udp_socket::wrap(char const* hostname, int port, char const* p, int len, error_code& ec) { CHECK_MAGIC; using namespace libtorrent::detail; char header[270]; char* h = header; write_uint16(0, h); // reserved write_uint8(0, h); // fragment write_uint8(3, h); // atyp int hostlen = (std::min)(strlen(hostname), size_t(255)); write_uint8(hostlen, h); // hostname len memcpy(h, hostname, hostlen); h += hostlen; write_uint16(port, h); boost::array iovec; iovec[0] = boost::asio::const_buffer(header, h - header); iovec[1] = boost::asio::const_buffer(p, len); #if TORRENT_USE_IPV6 if (m_udp_proxy_addr.address().is_v6() && m_ipv6_sock.is_open()) m_ipv6_sock.send_to(iovec, m_udp_proxy_addr, 0, ec); else #endif m_ipv4_sock.send_to(iovec, m_udp_proxy_addr, 0, ec); } // unwrap the UDP packet from the SOCKS5 header void udp_socket::unwrap(error_code const& e, char const* buf, int size) { CHECK_MAGIC; using namespace libtorrent::detail; // the minimum socks5 header size if (size <= 10) return; char const* p = buf; p += 2; // reserved int frag = read_uint8(p); // fragmentation is not supported if (frag != 0) return; udp::endpoint sender; int atyp = read_uint8(p); if (atyp == 1) { // IPv4 sender = read_v4_endpoint(p); } #if TORRENT_USE_IPV6 else if (atyp == 4) { // IPv6 sender = read_v6_endpoint(p); } #endif else { int len = read_uint8(p); if (len > (buf + size) - p) return; std::string hostname(p, p + len); p += len; call_handler(e, hostname.c_str(), p, size - (p - buf)); return; } call_handler(e, sender, p, size - (p - buf)); } #if !defined BOOST_ASIO_ENABLE_CANCELIO && defined TORRENT_WINDOWS #error BOOST_ASIO_ENABLE_CANCELIO needs to be defined when building libtorrent to enable cancel() in asio on windows #endif void udp_socket::close() { TORRENT_ASSERT(is_single_thread()); TORRENT_ASSERT(m_magic == 0x1337); error_code ec; m_ipv4_sock.close(ec); TORRENT_ASSERT_VAL(!ec || ec == error::bad_descriptor, ec); #if TORRENT_USE_IPV6 m_ipv6_sock.close(ec); TORRENT_ASSERT_VAL(!ec || ec == error::bad_descriptor, ec); #endif m_socks5_sock.close(ec); TORRENT_ASSERT_VAL(!ec || ec == error::bad_descriptor, ec); m_resolver.cancel(); m_timer.cancel(); m_abort = true; #if TORRENT_USE_ASSERTS m_outstanding_when_aborted = num_outstanding(); #endif } void udp_socket::set_buf_size(int s) { TORRENT_ASSERT(is_single_thread()); if (m_observers_locked) { // we can't actually reallocate the buffer while // it's being used by the observers, we have to // do that once we're done iterating over them m_new_buf_size = s; return; } if (s == m_buf_size) return; bool no_mem = false; char* tmp = static_cast(realloc(m_buf, s)); if (tmp != 0) { m_buf = tmp; m_buf_size = s; m_new_buf_size = s; } else { no_mem = true; } if (no_mem) { free(m_buf); m_buf = 0; m_buf_size = 0; m_new_buf_size = 0; udp::endpoint ep; call_handler(error::no_memory, ep, 0, 0); close(); } int size = m_buf_size; // don't shrink the size of the receive buffer error_code ec; boost::asio::socket_base::receive_buffer_size recv_size; m_ipv4_sock.get_option(recv_size, ec); if (!ec) size = (std::max)(recv_size.value(), size); #if TORRENT_USE_IPV6 m_ipv6_sock.get_option(recv_size, ec); if (!ec) size = (std::max)(recv_size.value(), size); #endif error_code ignore_errors; // set the internal buffer sizes as well m_ipv4_sock.set_option(boost::asio::socket_base::receive_buffer_size(size) , ignore_errors); #if TORRENT_USE_IPV6 m_ipv6_sock.set_option(boost::asio::socket_base::receive_buffer_size(size) , ignore_errors); #endif } void udp_socket::bind(udp::endpoint const& ep, error_code& ec) { CHECK_MAGIC; TORRENT_ASSERT(is_single_thread()); m_abort = false; if (m_ipv4_sock.is_open()) m_ipv4_sock.close(ec); #if TORRENT_USE_IPV6 if (m_ipv6_sock.is_open()) m_ipv6_sock.close(ec); #endif ec.clear(); if (ep.address().is_v4()) { m_ipv4_sock.open(udp::v4(), ec); if (ec) return; // this is best-effort. ignore errors error_code err; #ifdef TORRENT_WINDOWS m_ipv4_sock.set_option(exclusive_address_use(true), err); #endif m_ipv4_sock.set_option(boost::asio::socket_base::reuse_address(true), err); m_ipv4_sock.bind(ep, ec); if (ec) return; udp::socket::non_blocking_io ioc(true); m_ipv4_sock.io_control(ioc, ec); if (ec) return; setup_read(&m_ipv4_sock); } #if TORRENT_USE_IPV6 // TODO: 2 the udp_socket should really just be a single socket, and the // session should support having more than one, just like with TCP sockets // for now, just make bind failures non-fatal if (supports_ipv6() && (ep.address().is_v6() || is_any(ep.address()))) { udp::endpoint ep6 = ep; if (is_any(ep.address())) ep6.address(address_v6::any()); m_ipv6_sock.open(udp::v6(), ec); if (ec) return; // this is best-effort. ignore errors error_code err; #ifdef TORRENT_WINDOWS m_ipv6_sock.set_option(exclusive_address_use(true), err); #endif m_ipv6_sock.set_option(boost::asio::socket_base::reuse_address(true), err); m_ipv6_sock.set_option(boost::asio::ip::v6_only(true), err); m_ipv6_sock.bind(ep6, ec); if (ec != error_code(boost::system::errc::address_not_available , boost::system::generic_category())) { if (ec) return; udp::socket::non_blocking_io ioc(true); m_ipv6_sock.io_control(ioc, ec); if (ec) return; setup_read(&m_ipv6_sock); } else { ec.clear(); } } #endif #if TORRENT_USE_ASSERTS m_started = true; #endif m_bind_port = ep.port(); } void udp_socket::set_proxy_settings(aux::proxy_settings const& ps) { CHECK_MAGIC; TORRENT_ASSERT(is_single_thread()); error_code ec; m_socks5_sock.close(ec); m_tunnel_packets = false; m_proxy_settings = ps; if (m_abort) { close_impl(); return; } if (ps.type == settings_pack::socks5 || ps.type == settings_pack::socks5_pw) { m_queue_packets = true; // connect to socks5 server and open up the UDP tunnel // TODO: use the system resolver_interface here tcp::resolver::query q(ps.hostname, to_string(ps.port).elems); ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_resolve; #endif #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_name_lookup"); #endif m_resolver.async_resolve(q, boost::bind( &udp_socket::on_name_lookup, this, _1, _2)); } } void udp_socket::close_impl() { if (m_outstanding_ops == 0) { error_code ec; m_ipv4_sock.close(ec); #if TORRENT_USE_IPV6 m_ipv6_sock.close(ec); #endif m_socks5_sock.close(ec); } } void udp_socket::on_name_lookup(error_code const& e, tcp::resolver::iterator i) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_name_lookup"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_resolve > 0); --m_outstanding_resolve; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; if (e == boost::asio::error::operation_aborted) return; TORRENT_ASSERT(is_single_thread()); if (e) { if (m_force_proxy) { call_handler(e, udp::endpoint(), 0, 0); } else { // if we can't connect to the proxy, and // we're not in privacy mode, try to just // not use a proxy m_proxy_settings = aux::proxy_settings(); m_tunnel_packets = false; } drain_queue(); return; } m_proxy_addr.address(i->endpoint().address()); m_proxy_addr.port(i->endpoint().port()); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_connected"); #endif error_code ec; m_socks5_sock.open(m_proxy_addr.address().is_v4()?tcp::v4():tcp::v6(), ec); // enable keepalives m_socks5_sock.set_option(boost::asio::socket_base::keep_alive(true), ec); ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_connect; #endif m_socks5_sock.async_connect(tcp::endpoint(m_proxy_addr.address(), m_proxy_addr.port()) , boost::bind(&udp_socket::on_connected, this, _1)); ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_timeout; #endif #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_connect_timeout"); #endif m_timer.expires_from_now(seconds(10)); m_timer.async_wait(boost::bind(&udp_socket::on_connect_timeout , this, _1)); } void udp_socket::on_connect_timeout(error_code const& ec) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_connect_timeout"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_timeout > 0); --m_outstanding_timeout; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (ec == boost::asio::error::operation_aborted) return; m_queue_packets = false; if (m_abort) { close_impl(); return; } CHECK_MAGIC; TORRENT_ASSERT(is_single_thread()); error_code ignore; m_socks5_sock.close(ignore); } void udp_socket::on_connected(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_connected"); #endif TORRENT_ASSERT(is_single_thread()); #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_connect > 0); --m_outstanding_connect; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); CHECK_MAGIC; m_timer.cancel(); if (e == boost::asio::error::operation_aborted) return; if (m_abort) { close_impl(); return; } if (e) { // we failed to connect to the proxy, if we don't have force_proxy set, // drain the queue over the UDP socket if (!m_force_proxy) { drain_queue(); } call_handler(e, udp::endpoint(), 0, 0); return; } using namespace libtorrent::detail; // send SOCKS5 authentication methods char* p = &m_tmp_buf[0]; write_uint8(5, p); // SOCKS VERSION 5 if (m_proxy_settings.username.empty() || m_proxy_settings.type == settings_pack::socks5) { write_uint8(1, p); // 1 authentication method (no auth) write_uint8(0, p); // no authentication } else { write_uint8(2, p); // 2 authentication methods write_uint8(0, p); // no authentication write_uint8(2, p); // username/password } TORRENT_ASSERT_VAL(p - m_tmp_buf < int(sizeof(m_tmp_buf)), (p - m_tmp_buf)); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_handshake1"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_write(m_socks5_sock, boost::asio::buffer(m_tmp_buf, p - m_tmp_buf) , boost::bind(&udp_socket::handshake1, this, _1)); } void udp_socket::handshake1(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_handshake1"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; if (e) { drain_queue(); return; } TORRENT_ASSERT(is_single_thread()); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_handshake2"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_read(m_socks5_sock, boost::asio::buffer(m_tmp_buf, 2) , boost::bind(&udp_socket::handshake2, this, _1)); } void udp_socket::handshake2(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_handshake2"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; if (e) { drain_queue(); return; } using namespace libtorrent::detail; TORRENT_ASSERT(is_single_thread()); char* p = &m_tmp_buf[0]; int version = read_uint8(p); int method = read_uint8(p); if (version < 5) { error_code ec; m_socks5_sock.close(ec); drain_queue(); return; } if (method == 0) { socks_forward_udp(/*l*/); } else if (method == 2) { if (m_proxy_settings.username.empty()) { error_code ec; m_socks5_sock.close(ec); drain_queue(); return; } // start sub-negotiation p = &m_tmp_buf[0]; write_uint8(1, p); write_uint8(m_proxy_settings.username.size(), p); write_string(m_proxy_settings.username, p); write_uint8(m_proxy_settings.password.size(), p); write_string(m_proxy_settings.password, p); TORRENT_ASSERT_VAL(p - m_tmp_buf < int(sizeof(m_tmp_buf)), (p - m_tmp_buf)); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_handshake3"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_write(m_socks5_sock, boost::asio::buffer(m_tmp_buf, p - m_tmp_buf) , boost::bind(&udp_socket::handshake3, this, _1)); } else { drain_queue(); error_code ec; m_socks5_sock.close(ec); return; } } void udp_socket::handshake3(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_handshake3"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; if (e) { drain_queue(); return; } TORRENT_ASSERT(is_single_thread()); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::on_handshake4"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_read(m_socks5_sock, boost::asio::buffer(m_tmp_buf, 2) , boost::bind(&udp_socket::handshake4, this, _1)); } void udp_socket::handshake4(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::on_handshake4"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; if (e) { drain_queue(); return; } TORRENT_ASSERT(is_single_thread()); using namespace libtorrent::detail; char* p = &m_tmp_buf[0]; int version = read_uint8(p); int status = read_uint8(p); if (version != 1 || status != 0) { drain_queue(); return; } socks_forward_udp(/*l*/); } void udp_socket::socks_forward_udp() { CHECK_MAGIC; using namespace libtorrent::detail; // send SOCKS5 UDP command char* p = &m_tmp_buf[0]; write_uint8(5, p); // SOCKS VERSION 5 write_uint8(3, p); // UDP ASSOCIATE command write_uint8(0, p); // reserved error_code ec; write_uint8(1, p); // ATYP = IPv4 write_uint32(0, p); // 0.0.0.0 write_uint16(0, p); // :0 TORRENT_ASSERT_VAL(p - m_tmp_buf < int(sizeof(m_tmp_buf)), (p - m_tmp_buf)); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::connect1"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_write(m_socks5_sock, boost::asio::buffer(m_tmp_buf, p - m_tmp_buf) , boost::bind(&udp_socket::connect1, this, _1)); } void udp_socket::connect1(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::connect1"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; if (e) { drain_queue(); return; } TORRENT_ASSERT(is_single_thread()); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::connect2"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_read(m_socks5_sock, boost::asio::buffer(m_tmp_buf, 10) , boost::bind(&udp_socket::connect2, this, _1)); } void udp_socket::connect2(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::connect2"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { m_queue.clear(); return; } CHECK_MAGIC; if (e) { drain_queue(); return; } TORRENT_ASSERT(is_single_thread()); using namespace libtorrent::detail; char* p = &m_tmp_buf[0]; int version = read_uint8(p); // VERSION int status = read_uint8(p); // STATUS ++p; // RESERVED int atyp = read_uint8(p); // address type if (version != 5 || status != 0) { drain_queue(); return; } if (atyp == 1) { m_udp_proxy_addr.address(address_v4(read_uint32(p))); m_udp_proxy_addr.port(read_uint16(p)); } else { // in this case we need to read more data from the socket TORRENT_ASSERT(false); drain_queue(); return; } m_tunnel_packets = true; drain_queue(); #if defined TORRENT_ASIO_DEBUGGING add_outstanding_async("udp_socket::hung_up"); #endif ++m_outstanding_ops; #if TORRENT_USE_ASSERTS ++m_outstanding_socks; #endif boost::asio::async_read(m_socks5_sock, boost::asio::buffer(m_tmp_buf, 10) , boost::bind(&udp_socket::hung_up, this, _1)); } void udp_socket::hung_up(error_code const& e) { #if defined TORRENT_ASIO_DEBUGGING complete_async("udp_socket::hung_up"); #endif #if TORRENT_USE_ASSERTS TORRENT_ASSERT(m_outstanding_socks > 0); --m_outstanding_socks; #endif TORRENT_ASSERT(m_outstanding_ops > 0); --m_outstanding_ops; TORRENT_ASSERT(m_outstanding_ops == m_outstanding_connect + m_outstanding_timeout + m_outstanding_resolve + m_outstanding_socks); if (m_abort) { close_impl(); return; } CHECK_MAGIC; TORRENT_ASSERT(is_single_thread()); if (e == boost::asio::error::operation_aborted || m_abort) return; // the socks connection was closed, re-open it set_proxy_settings(m_proxy_settings); } void udp_socket::drain_queue() { m_queue_packets = false; // forward all packets that were put in the queue while (!m_queue.empty()) { queued_packet const& p = m_queue.front(); error_code ec; if (p.hostname) { udp_socket::send_hostname(p.hostname, p.ep.port(), &p.buf[0] , p.buf.size(), ec, p.flags | dont_queue); free(p.hostname); } else { udp_socket::send(p.ep, &p.buf[0], p.buf.size(), ec, p.flags | dont_queue); } m_queue.pop_front(); } } rate_limited_udp_socket::rate_limited_udp_socket(io_service& ios) : udp_socket(ios) , m_rate_limit(8000) , m_quota(8000) , m_last_tick(aux::time_now()) { } bool rate_limited_udp_socket::has_quota() { time_point now = clock_type::now(); time_duration delta = now - m_last_tick; m_last_tick = now; // add any new quota we've accrued since last time m_quota += boost::uint64_t(m_rate_limit) * total_microseconds(delta) / 1000000; return m_quota > 0; } bool rate_limited_udp_socket::send(udp::endpoint const& ep, char const* p , int len, error_code& ec, int flags) { time_point now = clock_type::now(); time_duration delta = now - m_last_tick; m_last_tick = now; // add any new quota we've accrued since last time m_quota += boost::uint64_t(m_rate_limit) * total_microseconds(delta) / 1000000; // allow 3 seconds worth of burst if (m_quota > 3 * m_rate_limit) m_quota = 3 * m_rate_limit; // if there's no quota, and it's OK to drop, just // drop the packet if (m_quota < 0 && (flags & dont_drop) == 0) return false; m_quota -= len; if (m_quota < 0) m_quota = 0; udp_socket::send(ep, p, len, ec, flags); return true; }