add support for IPv6 peers from udp trackers (#1802)

add support for IPv6 peers from udp trackers

ChangeLog

@@ -1,3 +1,4 @@
+	* add support for IPv6 peers from udp trackers
 	* correctly URL encode the IPv6 argument to trackers
 	* fix default file pool size on windows
 	* fix bug where settings_pack::file_pool_size setting was not being honored

src/udp_tracker_connection.cpp

@@ -598,8 +598,15 @@ namespace libtorrent
 		resp.min_interval = 60;
 		resp.incomplete = detail::read_int32(buf);
 		resp.complete = detail::read_int32(buf);
-		int num_peers = (size - 20) / 6;
+
-		if ((size - 20) % 6 != 0)
+		std::size_t const ip_stride =
+#if TORRENT_USE_IPV6
+			m_target.address().is_v6() ? 18 :
+#endif
+			6;
+
+		int const num_peers = (size - 20) / ip_stride;
+		if ((size - 20) % ip_stride != 0)
 		{
 			fail(error_code(errors::invalid_tracker_response_length));
 			return false;
@@ -619,14 +626,31 @@ namespace libtorrent
 			return true;
 		}
 
-		resp.peers4.reserve(num_peers);
+#if TORRENT_USE_IPV6
-		for (int i = 0; i < num_peers; ++i)
+		if (m_target.address().is_v6())
 		{
-			ipv4_peer_entry e;
+			resp.peers6.reserve(std::size_t(num_peers));
-			memcpy(&e.ip[0], buf, 4);
+			for (int i = 0; i < num_peers; ++i)
-			buf += 4;
+			{
-			e.port = detail::read_uint16(buf);
+				ipv6_peer_entry e;
-			resp.peers4.push_back(e);
+				std::memcpy(&e.ip[0], buf, 16);
+				buf += 16;
+				e.port = detail::read_uint16(buf);
+				resp.peers6.push_back(e);
+			}
+		}
+		else
+#endif
+		{
+			resp.peers4.reserve(std::size_t(num_peers));
+			for (int i = 0; i < num_peers; ++i)
+			{
+				ipv4_peer_entry e;
+				memcpy(&e.ip[0], buf, 4);
+				buf += 4;
+				e.port = detail::read_uint16(buf);
+				resp.peers4.push_back(e);
+			}
 		}
 
 		std::list<address> ip_list;

test/setup_transfer.cpp

@@ -264,7 +264,7 @@ void save_file(char const* filename, char const* data, int size)
 
 bool print_alerts(lt::session& ses, char const* name
 	, bool allow_disconnects, bool allow_no_torrents, bool allow_failed_fastresume
-	, bool (*predicate)(libtorrent::alert const*), bool no_output)
+	, boost::function<bool(libtorrent::alert const*)> predicate, bool no_output)
 {
 	bool ret = false;
 	std::vector<torrent_handle> handles = ses.get_torrents();

test/setup_transfer.hpp

@@ -75,7 +75,8 @@ EXPORT bool print_alerts(libtorrent::session& ses, char const* name
 	, bool allow_disconnects = false
 	, bool allow_no_torrents = false
 	, bool allow_failed_fastresume = false
-	, bool (*)(libtorrent::alert const*) = 0
+	, boost::function<bool(libtorrent::alert const*)> predicate
+		= boost::function<bool(libtorrent::alert const*)>()
 	, bool no_output = false);
 
 EXPORT void wait_for_listen(libtorrent::session& ses, char const* name);

test/test_tracker.cpp

@@ -312,17 +312,23 @@ TORRENT_TEST(extract_peer_missing_port)
 		, errors::invalid_tracker_response, false);
 }
 
-TORRENT_TEST(udp_tracker)
+bool connect_alert(libtorrent::alert const* a, tcp::endpoint& ep)
 {
-	int http_port = start_web_server();
+	if (peer_connect_alert const* pc = alert_cast<peer_connect_alert>(a))
-	int udp_port = start_udp_tracker();
+		ep = pc->ip;
+	return true;
+}
+
+void test_udp_tracker(std::string const& iface, address tracker, tcp::endpoint const& expected_peer)
+{
+	int const udp_port = start_udp_tracker(tracker);
 
 	int prev_udp_announces = num_udp_announces();
 
 	settings_pack pack = settings();
 	pack.set_bool(settings_pack::announce_to_all_trackers, true);
 	pack.set_bool(settings_pack::announce_to_all_tiers, true);
-	pack.set_str(settings_pack::listen_interfaces, "0.0.0.0:48875");
+	pack.set_str(settings_pack::listen_interfaces, iface + ":48875");
 
 	boost::scoped_ptr<lt::session> s(new lt::session(pack));
 
@@ -334,12 +340,9 @@ TORRENT_TEST(udp_tracker)
 	file.close();
 
 	char tracker_url[200];
-	snprintf(tracker_url, sizeof(tracker_url), "http://127.0.0.1:%d/announce", http_port);
+	snprintf(tracker_url, sizeof(tracker_url), "udp://%s:%d/announce", iface.c_str(), udp_port);
 	t->add_tracker(tracker_url, 0);
 
-	snprintf(tracker_url, sizeof(tracker_url), "udp://127.0.0.1:%d/announce", udp_port);
-	t->add_tracker(tracker_url, 1);
-
 	add_torrent_params addp;
 	addp.flags &= ~add_torrent_params::flag_paused;
 	addp.flags &= ~add_torrent_params::flag_auto_managed;
@@ -348,9 +351,11 @@ TORRENT_TEST(udp_tracker)
 	addp.save_path = "tmp1_tracker";
 	torrent_handle h = s->add_torrent(addp);
 
+	tcp::endpoint peer_ep;
 	for (int i = 0; i < 50; ++i)
 	{
-		print_alerts(*s, "s");
+		print_alerts(*s, "s", false, false, false, boost::bind(&connect_alert, _1, boost::ref(peer_ep)));
+
 		if (num_udp_announces() == prev_udp_announces + 1)
 			break;
 
@@ -370,7 +375,7 @@ TORRENT_TEST(udp_tracker)
 
 	for (int i = 0; i < 50; ++i)
 	{
-		print_alerts(*s, "s", true, true);
+		print_alerts(*s, "s", true, true, false, boost::bind(&connect_alert, _1, boost::ref(peer_ep)));
 		if (num_udp_announces() == prev_udp_announces + 2)
 			break;
 
@@ -379,6 +384,8 @@ TORRENT_TEST(udp_tracker)
 			, int(prev_udp_announces) + 1);
 	}
 
+	TEST_CHECK(peer_ep == expected_peer);
+
 	fprintf(stderr, "destructing session\n");
 	s.reset();
 	fprintf(stderr, "done\n");
@@ -387,6 +394,18 @@ TORRENT_TEST(udp_tracker)
 	TEST_EQUAL(num_udp_announces(), prev_udp_announces + 2);
 }
 
+TORRENT_TEST(udp_tracker_v4)
+{
+	test_udp_tracker("127.0.0.1", address_v4::any(), ep("1.3.3.7", 1337));
+}
+
+#if TORRENT_USE_IPV6
+TORRENT_TEST(udp_tracker_v6)
+{
+	test_udp_tracker("[::1]", address_v6::any(), ep("::1.3.3.7", 1337));
+}
+#endif
+
 TORRENT_TEST(http_peers)
 {
 	int http_port = start_web_server();

test/udp_tracker.cpp

@@ -120,9 +120,30 @@ struct udp_tracker
 				detail::write_uint32(1800, ptr); // interval
 				detail::write_uint32(1, ptr); // incomplete
 				detail::write_uint32(1, ptr); // complete
-				// 0 peers
+				// 1 peers
-				m_socket.send_to(boost::asio::buffer(buffer, 20), *from, 0, e);
+#if TORRENT_USE_IPV6
-				if (e) fprintf(stderr, "%s: UDP send_to failed. ERROR: %s\n"
+				if (from->address().is_v6())
+				{
+					detail::write_uint32(0, ptr);
+					detail::write_uint32(0, ptr);
+					detail::write_uint32(0, ptr);
+					detail::write_uint8(1, ptr);
+					detail::write_uint8(3, ptr);
+					detail::write_uint8(3, ptr);
+					detail::write_uint8(7, ptr);
+					detail::write_uint16(1337, ptr);
+				}
+				else
+#endif
+				{
+					detail::write_uint8(1, ptr);
+					detail::write_uint8(3, ptr);
+					detail::write_uint8(3, ptr);
+					detail::write_uint8(7, ptr);
+					detail::write_uint16(1337, ptr);
+				}
+				m_socket.send_to(boost::asio::buffer(buffer, ptr - buffer), *from, 0, e);
+				if (e) std::printf("%s: UDP send_to failed. ERROR: %s\n"
 					, time_now_string(), e.message().c_str());
 				else fprintf(stderr, "%s: UDP sent response to: %s\n"
 					, time_now_string(), print_endpoint(*from).c_str());
@@ -142,21 +163,21 @@ struct udp_tracker
 			, boost::bind(&udp_tracker::on_udp_receive, this, _1, _2, from, buffer, size));
 	}
 
-	udp_tracker()
+	udp_tracker(address iface)
 		: m_udp_announces(0)
 		, m_socket(m_ios)
 		, m_port(0)
 		, m_abort(false)
 	{
 		error_code ec;
-		m_socket.open(udp::v4(), ec);
+		m_socket.open(iface.is_v4() ? udp::v4() : udp::v6(), ec);
 		if (ec)
 		{
 			fprintf(stderr, "UDP Error opening listen UDP tracker socket: %s\n", ec.message().c_str());
 			return;
 		}
 
-		m_socket.bind(udp::endpoint(address_v4::any(), 0), ec);
+		m_socket.bind(udp::endpoint(iface, 0), ec);
 		if (ec)
 		{
 			fprintf(stderr, "UDP Error binding UDP tracker socket to port 0: %s\n", ec.message().c_str());
@@ -176,6 +197,7 @@ struct udp_tracker
 
 	void stop()
 	{
+		std::printf("%s: UDP tracker, stop\n", time_now_string());
 		m_abort = true;
 		m_socket.cancel();
 		m_socket.close();
@@ -222,9 +244,9 @@ struct udp_tracker
 
 boost::shared_ptr<udp_tracker> g_udp_tracker;
 
-int start_udp_tracker()
+int start_udp_tracker(address iface)
 {
-	g_udp_tracker.reset(new udp_tracker);
+	g_udp_tracker.reset(new udp_tracker(iface));
 	return g_udp_tracker->port();
 }
 

test/udp_tracker.hpp

@@ -31,9 +31,11 @@ POSSIBILITY OF SUCH DAMAGE.
 */
 
 #include "test.hpp" // for EXPORT
+#include "libtorrent/address.hpp"
 
 // returns the port the udp tracker is running on
-int EXPORT start_udp_tracker();
+int EXPORT start_udp_tracker(libtorrent::address iface
+	= libtorrent::address_v4::any());
 
 // the number of udp tracker announces received
 int EXPORT num_udp_announces();