Set connection timeout when next endpoint is tried (#1952)

ChangeLog

@@ -1,3 +1,4 @@
+	* fix http connection timeout on multi-homed hosts
 	* removed depdendency on boost::uintptr_t for better compatibility
 	* fix memory leak in the disk cache
 	* fix double free in disk cache

simulation/libsimulator

@@ -1 +1 @@
-Subproject commit 60d786b8fa6ddaacdc98bdf691220660bc194494
+Subproject commit 0e8d74baf1f6d9db19857eaa87734faecd530f94

simulation/test_http_connection.cpp

@@ -83,6 +83,13 @@ struct sim_config : sim::default_config
 			return duration_cast<chrono::high_resolution_clock::duration>(chrono::milliseconds(100));
 		}
 
+		if (hostname == "dual-stack.test-hostname.com")
+		{
+			result.push_back(address_v4::from_string("10.0.0.2"));
+			result.push_back(address_v6::from_string("ff::dead:beef"));
+			return duration_cast<chrono::high_resolution_clock::duration>(chrono::milliseconds(100));
+		}
+
 		return default_config::hostname_lookup(requestor, hostname, result, ec);
 	}
 };
@@ -225,8 +232,12 @@ void run_suite(lt::aux::proxy_settings ps)
 	if (ps.type != settings_pack::socks5
 		&& ps.type != settings_pack::http)
 	{
+		const auto expected_code = ps.type == settings_pack::socks4 ?
+			boost::system::errc::address_family_not_supported :
+			boost::system::errc::address_not_available;
+
 		run_test(ps, "http://[ff::dead:beef]:8080/test_file", 0, -1
-			, error_condition(boost::system::errc::address_family_not_supported, generic_category())
+			, error_condition(expected_code, generic_category())
 			, {0,1});
 	}
 
@@ -438,6 +449,102 @@ TORRENT_TEST(http_connection_socks5_proxy_names)
 	run_suite(ps);
 }
 
+// tests the error scenario of a http server listening on two sockets (ipv4/ipv6) which
+// both accept the incoming connection but never send anything back. we test that
+// both ip addresses get tried in turn and that the connection attempts time out as expected.
+TORRENT_TEST(http_connection_timeout_server_stalls)
+{
+	sim_config network_cfg;
+	sim::simulation sim{network_cfg};
+	// server has two ip addresses (ipv4/ipv6)
+	sim::asio::io_service server_ios(sim, address_v4::from_string("10.0.0.2"));
+	sim::asio::io_service server_ios_ipv6(sim, address_v6::from_string("ff::dead:beef"));
+	// same for client
+	sim::asio::io_service client_ios(sim, {
+		address_v4::from_string("10.0.0.1"),
+		address_v6::from_string("ff::abad:cafe")
+	});
+	lt::resolver resolver(client_ios);
+
+	const unsigned short http_port = 8080;
+	sim::http_server http(server_ios, http_port);
+	sim::http_server http_ipv6(server_ios_ipv6, http_port);
+
+	http.register_stall_handler("/timeout");
+	http_ipv6.register_stall_handler("/timeout");
+
+	char data_buffer[4000];
+	std::generate(data_buffer, data_buffer + sizeof(data_buffer), &std::rand);
+
+	int connect_counter = 0;
+	int handler_counter = 0;
+
+	error_condition timed_out(boost::system::errc::timed_out, boost::system::generic_category());
+
+	auto c = test_request(client_ios, resolver
+		, "http://dual-stack.test-hostname.com:8080/timeout", data_buffer, -1, -1
+		, timed_out, lt::aux::proxy_settings()
+		, &connect_counter, &handler_counter);
+
+	error_code e;
+	sim.run(e);
+	TEST_CHECK(!e);
+	TEST_EQUAL(2, connect_counter); // both endpoints are connected to
+	TEST_EQUAL(1, handler_counter); // the handler only gets called once with error_code == timed_out
+}
+
+// tests the error scenario of a http server listening on two sockets (ipv4/ipv6) neither of which
+// accept incoming connections. we test that both ip addresses get tried in turn and that the
+// connection attempts time out as expected.
+TORRENT_TEST(http_connection_timeout_server_does_not_accept)
+{
+	sim_config network_cfg;
+	sim::simulation sim{network_cfg};
+	// server has two ip addresses (ipv4/ipv6)
+	sim::asio::io_service server_ios(sim, {
+		address_v4::from_string("10.0.0.2"),
+		address_v6::from_string("ff::dead:beef")
+	});
+	// same for client
+	sim::asio::io_service client_ios(sim, {
+		address_v4::from_string("10.0.0.1"),
+		address_v6::from_string("ff::abad:cafe")
+	});
+	lt::resolver resolver(client_ios);
+
+	const unsigned short http_port = 8080;
+
+	// listen on two sockets, but don't accept connections
+	asio::ip::tcp::acceptor server_socket_ipv4(server_ios);
+	server_socket_ipv4.open(tcp::v4());
+	server_socket_ipv4.bind(tcp::endpoint(address_v4::any(), http_port));
+	server_socket_ipv4.listen();
+
+	asio::ip::tcp::acceptor server_socket_ipv6(server_ios);
+	server_socket_ipv6.open(tcp::v6());
+	server_socket_ipv6.bind(tcp::endpoint(address_v6::any(), http_port));
+	server_socket_ipv6.listen();
+
+	int connect_counter = 0;
+	int handler_counter = 0;
+
+	error_condition timed_out(boost::system::errc::timed_out, boost::system::generic_category());
+
+	char data_buffer[4000];
+	std::generate(data_buffer, data_buffer + sizeof(data_buffer), &std::rand);
+
+	auto c = test_request(client_ios, resolver
+		, "http://dual-stack.test-hostname.com:8080/timeout_server_does_not_accept", data_buffer, -1, -1
+		, timed_out, lt::aux::proxy_settings()
+		, &connect_counter, &handler_counter);
+
+	error_code e;
+	sim.run(e);
+	TEST_CHECK(!e);
+	TEST_EQUAL(0, connect_counter); // no connection takes place
+	TEST_EQUAL(1, handler_counter); // the handler only gets called once with error_code == timed_out
+}
+
 void test_proxy_failure(lt::settings_pack::proxy_type_t proxy_type)
 {
 	using sim::asio::ip::address_v4;

src/http_connection.cpp

@@ -449,12 +449,14 @@ void http_connection::on_timeout(boost::weak_ptr<http_connection> p
 			error_code ec;
 			c->m_sock.close(ec);
 			if (!c->m_connecting) c->connect();
+			c->m_last_receive = now;
+			c->m_start_time = c->m_last_receive;
 		}
 		else
 		{
 			c->callback(boost::asio::error::timed_out);
+			return;
 		}
-		return;
 	}
 	else
 	{