changes to ut_pex, added support for seed flag in pex messages

include/libtorrent/policy.hpp

@@ -86,7 +86,8 @@ namespace libtorrent
 
 		// this is called once for every peer we get from
 		// the tracker
-		void peer_from_tracker(const tcp::endpoint& remote, const peer_id& pid);
+		void peer_from_tracker(const tcp::endpoint& remote, const peer_id& pid
+			, char flags = 0);
 
 		// called when an incoming connection is accepted
 		void new_connection(peer_connection& c);
@@ -101,7 +102,10 @@ namespace libtorrent
 
 		// is called when a peer is believed to have
 		// sent invalid data
-		void ban_peer(const peer_connection& c);
+		void ban_peer(peer_connection const& c);
+
+		// is called on peers that become seeds
+		void set_seed(peer_connection const& c);
 
 		// the peer has got at least one interesting piece
 		void peer_is_interesting(peer_connection& c);
@@ -144,6 +148,9 @@ namespace libtorrent
 			tcp::endpoint ip;
 			connection_type type;
 
+			// this is true if the peer is a seed
+			bool seed;
+
 			// the time when this peer was optimistically unchoked
 			// the last time.
 			boost::posix_time::ptime last_optimistically_unchoked;

src/peer_connection.cpp

@@ -678,9 +678,13 @@ namespace libtorrent
 					t->get_policy().peer_is_interesting(*this);
 			}
 
-			if (t->is_seed() && is_seed())
+			if (is_seed())
 			{
-				throw protocol_error("seed to seed connection redundant, disconnecting");
+				t->get_policy().set_seed(*this);
+				if (t->is_seed())
+				{
+					throw protocol_error("seed to seed connection redundant, disconnecting");
+				}
 			}
 		}
 	}
@@ -751,6 +755,7 @@ namespace libtorrent
 #ifdef TORRENT_VERBOSE_LOGGING
 			(*m_logger) << " *** THIS IS A SEED ***\n";
 #endif
+			t->get_policy().set_seed(*this);
 			// if we're a seed too, disconnect
 			if (t->is_seed())
 			{

src/policy.cpp

@@ -512,9 +512,10 @@ namespace libtorrent
 		for (std::vector<peer>::iterator i = m_peers.begin();
 			i != m_peers.end(); ++i)
 		{
-			if(i->connection) continue;
-			if(i->banned) continue;
-			if(i->type == peer::not_connectable) continue;
+			if (i->connection) continue;
+			if (i->banned) continue;
+			if (i->type == peer::not_connectable) continue;
+			if (i->seed && m_torrent->is_seed()) continue;
 
 			assert(i->connected <= local_time);
 
@@ -857,7 +858,7 @@ namespace libtorrent
 		}
 	}
 
-	void policy::ban_peer(const peer_connection& c)
+	void policy::ban_peer(peer_connection const& c)
 	{
 		INVARIANT_CHECK;
 
@@ -881,6 +882,21 @@ namespace libtorrent
 		i->banned = true;
 	}
 
+	void policy::set_seed(peer_connection const& c)
+	{
+		INVARIANT_CHECK;
+
+		std::vector<peer>::iterator i = std::find_if(
+			m_peers.begin()
+			, m_peers.end()
+			, match_peer_connection(c));
+
+		// it might be an http-seed
+		if (i == m_peers.end()) return;
+
+		i->seed = true;
+	}
+
 	void policy::new_connection(peer_connection& c)
 	{
 		assert(!c.is_local());
@@ -974,7 +990,8 @@ namespace libtorrent
 		m_last_optimistic_disconnect = second_clock::universal_time();
 	}
 
-	void policy::peer_from_tracker(const tcp::endpoint& remote, const peer_id& pid)
+	void policy::peer_from_tracker(const tcp::endpoint& remote, const peer_id& pid
+		, char flags)
 	{
 		INVARIANT_CHECK;
 
@@ -1012,6 +1029,7 @@ namespace libtorrent
 				// the iterator is invalid
 				// because of the push_back()
 				i = m_peers.end() - 1;
+				if (flags & 0x02) p.seed = true;
 				just_added = true;
 			}
 			else
@@ -1022,6 +1040,7 @@ namespace libtorrent
 				// not known, so save it. Client may also have changed port
 				// for some reason.
 				i->ip = remote;
+				if (flags & 0x02) i->seed = true;
 
 				if (i->connection)
 				{
@@ -1386,7 +1405,8 @@ namespace libtorrent
 #endif
 
 	policy::peer::peer(const tcp::endpoint& ip_, peer::connection_type t)
-		: ip(ip_)
+		: seed(false)
+		, ip(ip_)
 		, type(t)
 		, last_optimistically_unchoked(
 			boost::gregorian::date(1970,boost::gregorian::Jan,1))

src/torrent.cpp

@@ -519,7 +519,7 @@ namespace libtorrent
 				get_handle(), peers.size(), "Got peers from DHT"));
 		}
 		std::for_each(peers.begin(), peers.end(), bind(
-			&policy::peer_from_tracker, boost::ref(m_policy), _1, peer_id(0)));
+			&policy::peer_from_tracker, boost::ref(m_policy), _1, peer_id(0), 0));
 	}
 
 #endif

src/ut_pex.cpp

@@ -81,7 +81,19 @@ namespace libtorrent { namespace
 			if (++m_1_minute < 60) return;
 
 			m_1_minute = 0;
-			std::list<tcp::endpoint> cs;
+
+			entry pex;
+			std::string& pla = pex["added"].string();
+			std::string& pld = pex["dropped"].string();
+			std::string& plf = pex["added.f"].string();
+			std::back_insert_iterator<std::string> pla_out(pla);
+			std::back_insert_iterator<std::string> pld_out(pld);
+			std::back_insert_iterator<std::string> plf_out(plf);
+
+			std::set<tcp::endpoint> dropped;
+			m_old_peers.swap(dropped);
+
+			int num_added = 0;
 			for (torrent::peer_iterator i = m_torrent.begin()
 				, end(m_torrent.end()); i != end; ++i)
 			{	
@@ -90,52 +102,41 @@ namespace libtorrent { namespace
 				if (!i->second->is_local()) continue;
 				// don't send out peers that we haven't successfully connected to
 				if (i->second->is_connecting()) continue;
-				cs.push_back(i->first);
-			}
-			std::list<tcp::endpoint> added_peers, dropped_peers;
+				// ut pex does not support IPv6
+				if (!i->first.address().is_v4()) continue;
 
-			std::set_difference(cs.begin(), cs.end(), m_old_peers.begin()
-				, m_old_peers.end(), std::back_inserter(added_peers));
-			std::set_difference(m_old_peers.begin(), m_old_peers.end()
-				, cs.begin(), cs.end(), std::back_inserter(dropped_peers));
-			m_old_peers = cs;
+				m_old_peers.insert(i->first);
 
-			unsigned int num_peers = max_peer_entries;
+				std::set<tcp::endpoint>::iterator di = dropped.find(i->first);
+				if (di == dropped.end())
+				{
+					// don't write too big of a package
+					if (num_added >= max_peer_entries) continue;
 
-			std::string pla, pld, plf;
-			std::back_insert_iterator<std::string> pla_out(pla);
-			std::back_insert_iterator<std::string> pld_out(pld);
-			std::back_insert_iterator<std::string> plf_out(plf);
-
-			// TODO: use random selection in case added_peers.size() > num_peers
-			for (std::list<tcp::endpoint>::const_iterator i = added_peers.begin()
-				, end(added_peers.end());i != end; ++i)
-			{	
-				if (!i->address().is_v4()) continue;
-				detail::write_endpoint(*i, pla_out);
-				// no supported flags to set yet
-				// 0x01 - peer supports encryption
-				detail::write_uint8(0, plf_out);
-
-				if (--num_peers == 0) break;
+					// i->first was added since the last time
+					detail::write_endpoint(i->first, pla_out);
+					// no supported flags to set yet
+					// 0x01 - peer supports encryption
+					// 0x02 - peer is a seed
+					int flags = i->second->is_seed() ? 2 : 0;
+					detail::write_uint8(flags, plf_out);
+					++num_added;
+				}
+				else
+				{
+					// this was in the previous message
+					// so, it wasn't dropped
+					dropped.erase(di);
+				}
 			}
 
-			num_peers = max_peer_entries;
-			// TODO: use random selection in case dropped_peers.size() > num_peers
-			for (std::list<tcp::endpoint>::const_iterator i = dropped_peers.begin()
-				, end(dropped_peers.end());i != end; ++i)
+			for (std::set<tcp::endpoint>::const_iterator i = dropped.begin()
+				, end(dropped.end());i != end; ++i)
 			{	
 				if (!i->address().is_v4()) continue;
 				detail::write_endpoint(*i, pld_out);
-
-				if (--num_peers == 0) break;
 			}
 
-			entry pex(entry::dictionary_t);
-			pex["added"] = pla;
-			pex["dropped"] = pld;
-			pex["added.f"] = plf;
-
 			m_ut_pex_msg.clear();
 			bencode(std::back_inserter(m_ut_pex_msg), pex);
 		}
@@ -143,7 +144,7 @@ namespace libtorrent { namespace
 	private:
 		torrent& m_torrent;
 
-		std::list<tcp::endpoint> m_old_peers;
+		std::set<tcp::endpoint> m_old_peers;
 		int m_1_minute;
 		std::vector<char> m_ut_pex_msg;
 	};
@@ -182,6 +183,7 @@ namespace libtorrent { namespace
 		}
 
 		virtual bool on_extended(int length, int msg, buffer::const_interval body)
+			try
 		{
 			if (msg != extension_index) return false;
 			if (m_message_index == 0) return false;
@@ -194,26 +196,32 @@ namespace libtorrent { namespace
 			// in case we are a seed we do not use the peers
 			// from the pex message to prevent us from 
 			// overloading ourself
-			if (m_torrent.is_seed()) return true;
 			
-			entry Pex = bdecode(body.begin, body.end);
-			entry* PeerList = Pex.find_key("added");
+			entry pex_msg = bdecode(body.begin, body.end);
+			std::string const& peers = pex_msg["added"].string();
+			std::string const& peer_flags = pex_msg["added.f"].string();
 
-			if (!PeerList) return true;
-			std::string const& peers = PeerList->string();
 			int num_peers = peers.length() / 6;
 			char const* in = peers.c_str();
+			char const* fin = peer_flags.c_str();
 
-			peer_id pid;
-			pid.clear();
+			if (int(peer_flags.size()) != num_peers)
+				return true;
+
+			peer_id pid(0);
 			policy& p = m_torrent.get_policy();
 			for (int i = 0; i < num_peers; ++i)
 			{
 				tcp::endpoint adr = detail::read_v4_endpoint<tcp::endpoint>(in);
-				if (!m_torrent.connection_for(adr)) p.peer_from_tracker(adr, pid);
+				char flags = detail::read_uint8(fin);
+				p.peer_from_tracker(adr, pid, flags);
 			} 
 			return true;
 		}
+		catch (std::exception&)
+		{
+			return true;
+		}
 
 		// the peers second tick
 		// every minute we send a pex message