delay 5 seconds before reconnecting socks5 proxy for UDP ASSOCIATE

ChangeLog

@@ -1,3 +1,4 @@
+	* delay 5 seconds before reconnecting socks5 proxy for UDP ASSOCIATE
 	* fix NAT-PMP crash when removing a mapping at the wrong time
 	* improve path sanitization (filter unicode text direction characters)
 	* deprecate partial_piece_info::piece_state

include/libtorrent/udp_socket.hpp

@@ -234,6 +234,7 @@ namespace libtorrent
 		void connect1(error_code const& e);
 		void connect2(error_code const& e);
 		void hung_up(error_code const& e);
+		void retry_socks_connect(error_code const& ec);
 
 		void drain_queue();
 
@@ -268,6 +269,7 @@ namespace libtorrent
 #endif
 
 		tcp::socket m_socks5_sock;
+		deadline_timer m_retry_timer;
 		aux::proxy_settings m_proxy_settings;
 		tcp::resolver m_resolver;
 		char m_tmp_buf[270];

simulation/libsimulator

@@ -1 +1 @@
-Subproject commit 70feadef80dc76ae6d5e7c2f92334377d698dd7d
+Subproject commit 96e8e2414df955c04b37b6bccd2b7360a54ff2f1

simulation/test_socks5.cpp

@@ -254,3 +254,39 @@ TORRENT_TEST(udp_tracker)
 	TEST_CHECK(announced);
 }
 
+TORRENT_TEST(socks5_udp_retry)
+{
+	// this test is asserting that when a UDP associate command fails, we have a
+	// 5 second delay before we try again. There is no need to actually add a
+	// torrent for this test, just to open the udp socket with a socks5 proxy
+	using namespace libtorrent;
+
+	// setup the simulation
+	sim::default_config network_cfg;
+	sim::simulation sim{network_cfg};
+	std::unique_ptr<sim::asio::io_service> ios = make_io_service(sim, 0);
+	lt::session_proxy zombie;
+
+	sim::asio::io_service proxy_ios{sim, addr("50.50.50.50") };
+	// close UDP associate connectons prematurely
+	sim::socks_server socks5(proxy_ios, 5555, 5, socks_flag::disconnect_udp_associate);
+
+	lt::settings_pack pack = settings();
+	// create session
+	std::shared_ptr<lt::session> ses = std::make_shared<lt::session>(pack, *ios);
+	set_proxy(*ses, settings_pack::socks5);
+
+	// run for 60 seconds.The sokcks5 retry interval is expected to be 5 seconds,
+	// meaning there should have been 12 connection attempts
+	sim::timer t(sim, lt::seconds(60), [&](boost::system::error_code const& ec)
+	{
+		fprintf(stderr, "shutting down\n");
+		// shut down
+		zombie = ses->abort();
+		ses.reset();
+	});
+	sim.run();
+
+	// number of UDP ASSOCIATE commands invoked on the socks proxy
+	TEST_EQUAL(socks5.cmd_counts()[2], 12);
+}

src/udp_socket.cpp

@@ -74,6 +74,7 @@ udp_socket::udp_socket(io_service& ios)
 	, m_restart_v6(false)
 #endif
 	, m_socks5_sock(ios)
+	, m_retry_timer(ios)
 	, m_resolver(ios)
 	, m_queue_packets(false)
 	, m_tunnel_packets(false)
@@ -1464,7 +1465,15 @@ void udp_socket::hung_up(error_code const& e)
 
 	if (e == boost::asio::error::operation_aborted || m_abort) return;
 
-	// the socks connection was closed, re-open it
+	// the socks connection was closed, re-open it in a bit
+	m_retry_timer.expires_from_now(seconds(5));
+	m_retry_timer.async_wait(boost::bind(&udp_socket::retry_socks_connect
+		, this, _1));
+}
+
+void udp_socket::retry_socks_connect(error_code const& ec)
+{
+	if (ec) return;
 	set_proxy_settings(m_proxy_settings);
 }