the DHT can now change listen port runtime, and the same listen interface will be used for the DHT as is used for the torrent listen port. The DHT buckets are refreshed slightly more evenly distributed over time.

examples/client_test.cpp

@@ -899,10 +899,10 @@ int main(int ac, char* av[])
 					for (int i = 0; i < info.num_files(); ++i)
 					{
 						if (file_progress[i] == 1.f)
-							out << progress_bar(file_progress[i], 10, "32") << " "
+							out << progress_bar(file_progress[i], 20, "32") << " "
 								<< info.file_at(i).path.leaf() << "\n";
 						else
-							out << progress_bar(file_progress[i], 10, "33") << " "
+							out << progress_bar(file_progress[i], 20, "33") << " "
 								<< info.file_at(i).path.leaf() << "\n";
 					}
 

include/libtorrent/kademlia/dht_tracker.hpp

@@ -62,11 +62,13 @@ namespace libtorrent { namespace dht
 	struct dht_tracker
 	{
 		dht_tracker(asio::io_service& d, dht_settings const& settings
-			, entry const& bootstrap);
+			, asio::ip::address listen_interface, entry const& bootstrap);
 
 		void add_node(udp::endpoint node);
 		void add_node(std::pair<std::string, int> const& node);
 		
+		void rebind(asio::ip::address interface, int listen_port);
+
 		entry state() const;
 
 		void announce(sha1_hash const& ih, int listen_port

include/libtorrent/kademlia/routing_table.hpp

@@ -216,7 +216,8 @@ private:
 	typedef boost::array<std::pair<bucket_t, bucket_t>, 160> table_t;
 	table_t m_buckets;
 	// timestamps of the last activity in each bucket
-	boost::array<boost::posix_time::ptime, 160> m_bucket_activity;
+	typedef boost::array<boost::posix_time::ptime, 160> table_activity_t;
+	table_activity_t m_bucket_activity;
 	node_id m_id; // our own node id
 	
 	// this is the lowest bucket index with nodes in it

src/kademlia/dht_tracker.cpp

@@ -115,9 +115,9 @@ namespace libtorrent { namespace dht
 	// class that puts the networking and the kademlia node in a single
 	// unit and connecting them together.
 	dht_tracker::dht_tracker(asio::io_service& d, dht_settings const& settings
-		, entry const& bootstrap)
+		, asio::ip::address listen_interface, entry const& bootstrap)
 		: m_demuxer(d)
-		, m_socket(m_demuxer, udp::endpoint(address(), settings.service_port))
+		, m_socket(m_demuxer, udp::endpoint(listen_interface, settings.service_port))
 		, m_dht(bind(&dht_tracker::send_packet, this, _1), settings
 			, read_id(bootstrap))
 		, m_buffer(0)
@@ -215,6 +215,14 @@ namespace libtorrent { namespace dht
 		assert(false);
 	};
 
+	void dht_tracker::rebind(asio::ip::address listen_interface, int listen_port)
+	{
+		m_socket.close();
+		m_socket.open(asio::ip::udp::v4());
+		m_socket.bind(udp::endpoint(listen_interface, listen_port));
+		assert(m_settings.service_port == listen_port);
+	}
+
 	void dht_tracker::tick(asio::error const& e)
 		try
 	{

src/kademlia/routing_table.cpp

@@ -66,8 +66,10 @@ routing_table::routing_table(node_id const& id, int bucket_size
 	, m_id(id)
 	, m_lowest_active_bucket(160)
 {
-	std::fill(m_bucket_activity.begin(), m_bucket_activity.end()
-		, second_clock::universal_time() - hours(1));
+	// distribute the refresh times for the buckets in an
+	// attempt do even out the network load
+	for (int i = 0; i < 160; ++i)
+		m_bucket_activity[i] = second_clock::universal_time() - seconds(15*60 - i*5);
 }
 
 boost::tuple<int, int> routing_table::size() const

src/session.cpp

@@ -1425,6 +1425,16 @@ namespace libtorrent
 		if (m_impl.m_listen_socket)
 			m_impl.m_listen_socket.reset();
 			
+#ifndef TORRENT_DISABLE_DHT
+		if (m_impl.m_listen_interface.address() != new_interface.address()
+			&& m_impl.m_dht)
+		{
+			// the listen interface changed, rebind the dht listen socket as well
+			m_impl.m_dht->rebind(new_interface.address()
+				, m_impl.m_dht_settings.service_port);
+		}
+#endif
+
 		m_impl.m_incoming_connection = false;
 		m_impl.m_listen_interface = new_interface;
 
@@ -1466,7 +1476,8 @@ namespace libtorrent
 	void session::start_dht(entry const& startup_state)
 	{
 		m_impl.m_dht.reset(new dht::dht_tracker(m_impl.m_selector
-			, m_impl.m_dht_settings, startup_state));
+			, m_impl.m_dht_settings, m_impl.m_listen_interface.address()
+			, startup_state));
 	}
 
 	void session::stop_dht()
@@ -1479,8 +1490,8 @@ namespace libtorrent
 		if (settings.service_port != m_impl.m_dht_settings.service_port
 			&& m_impl.m_dht)
 		{
-			assert(false); // not implemented yet
-			// TODO: change dht service port!
+			m_impl.m_dht->rebind(m_impl.m_listen_interface.address()
+				, settings.service_port);
 		}
 		m_impl.m_dht_settings = settings;
 	}