support for dont-have extension message

ChangeLog

@@ -88,6 +88,7 @@
 	  incoming connection
 	* added more detailed instrumentation of the disk I/O thread
 
+	* add support for dont-have extension message
 	* fix for set_piece_deadline
 	* add reset_piece_deadline function
 	* fix merkle tree torrent assert

include/libtorrent/bt_peer_connection.hpp

@@ -106,7 +106,8 @@ namespace libtorrent
 		{
 			upload_only_msg = 2,
 			holepunch_msg = 3,
-			share_mode_msg = 4
+			share_mode_msg = 4,
+			dont_have_msg = 5,
 		};
 
 		~bt_peer_connection();
@@ -383,6 +384,9 @@ private:
 		// the message ID for holepunch messages
 		boost::uint8_t m_holepunch_id;
 
+		// the message ID for don't-have message
+		boost::uint8_t m_dont_have_id;
+
 		// the message ID for share mode message
 		// 0 if not supported
 		boost::uint8_t m_share_mode_id;

include/libtorrent/error_code.hpp

@@ -167,7 +167,7 @@ namespace libtorrent
 			invalid_lt_tracker_message,
 			too_frequent_pex,
 			no_metadata,
-			reserved110,
+			invalid_dont_have,
 			reserved111,
 			reserved112,
 			reserved113,

include/libtorrent/extensions.hpp

@@ -184,6 +184,9 @@ namespace libtorrent
 		virtual bool on_have(int index)
 		{ return false; }
 
+		virtual bool on_dont_have(int index)
+		{ return false; }
+
 		virtual bool on_bitfield(bitfield const& bitfield)
 		{ return false; }
 

include/libtorrent/peer_connection.hpp

@@ -458,6 +458,7 @@ namespace libtorrent
 		void incoming_interested();
 		void incoming_not_interested();
 		void incoming_have(int piece_index);
+		void incoming_dont_have(int piece_index);
 		void incoming_bitfield(bitfield const& bits);
 		void incoming_request(peer_request const& r);
 		void incoming_piece(peer_request const& p, disk_buffer_holder& data);

src/bt_peer_connection.cpp

@@ -102,6 +102,7 @@ namespace libtorrent
 #ifndef TORRENT_DISABLE_EXTENSIONS
 		, m_upload_only_id(0)
 		, m_holepunch_id(0)
+		, m_dont_have_id(0)
 		, m_share_mode_id(0)
 		, m_supports_extensions(false)
 #endif
@@ -138,6 +139,7 @@ namespace libtorrent
 #ifndef TORRENT_DISABLE_EXTENSIONS
 		, m_upload_only_id(0)
 		, m_holepunch_id(0)
+		, m_dont_have_id(0)
 		, m_share_mode_id(0)
 		, m_supports_extensions(false)
 #endif
@@ -1605,6 +1607,13 @@ namespace libtorrent
 		if (extended_id == upload_only_msg)
 		{
 			if (!packet_finished()) return;
+			if (packet_size() != 1)
+			{
+#ifdef TORRENT_VERBOSE_LOGGING
+				peer_log("<== UPLOAD_ONLY [ ERROR: unexpected packet size: %d ]", packet_size());
+#endif
+				return;
+			}
 			bool ul = detail::read_uint8(recv_buffer.begin) != 0;
 #ifdef TORRENT_VERBOSE_LOGGING
 			peer_log("<== UPLOAD_ONLY [ %s ]", (ul?"true":"false"));
@@ -1616,6 +1625,13 @@ namespace libtorrent
 		if (extended_id == share_mode_msg)
 		{
 			if (!packet_finished()) return;
+			if (packet_size() != 1)
+			{
+#ifdef TORRENT_VERBOSE_LOGGING
+				peer_log("<== SHARE_MODE [ ERROR: unexpected packet size: %d ]", packet_size());
+#endif
+				return;
+			}
 			bool sm = detail::read_uint8(recv_buffer.begin) != 0;
 #ifdef TORRENT_VERBOSE_LOGGING
 			peer_log("<== SHARE_MODE [ %s ]", (sm?"true":"false"));
@@ -1634,6 +1650,21 @@ namespace libtorrent
 			return;
 		}
 
+		if (extended_id == dont_have_msg)
+		{
+			if (!packet_finished()) return;
+			if (packet_size() != 4)
+			{
+#ifdef TORRENT_VERBOSE_LOGGING
+				peer_log("<== DONT_HAVE [ ERROR: unexpected packet size: %d ]", packet_size());
+#endif
+				return;
+			}
+			int piece = detail::read_uint32(recv_buffer.begin) != 0;
+			incoming_dont_have(piece);
+			return;
+		}
+
 #ifdef TORRENT_VERBOSE_LOGGING
 		if (packet_finished())
 			peer_log("<== EXTENSION MESSAGE [ msg: %d size: %d ]"
@@ -1698,6 +1729,7 @@ namespace libtorrent
 		{
 			m_upload_only_id = boost::uint8_t(m->dict_find_int_value("upload_only", 0));
 			m_holepunch_id = boost::uint8_t(m->dict_find_int_value("ut_holepunch", 0));
+			m_dont_have_id = boost::uint8_t(m->dict_find_int_value("lt_donthave", 0));
 		}
 #endif
 
@@ -2082,6 +2114,7 @@ namespace libtorrent
 		m["upload_only"] = upload_only_msg;
 		m["ut_holepunch"] = holepunch_msg;
 		m["share_mode"] = share_mode_msg;
+		m["lt_donthave"] = dont_have_msg;
 
 		int complete_ago = -1;
 		if (t->last_seen_complete() > 0) complete_ago = t->time_since_complete();

src/error_code.cpp

@@ -159,7 +159,7 @@ namespace libtorrent
 			"invalid lt_tracker message",
 			"pex messages sent too frequent (possible attack)",
 			"torrent has no metadata",
-			"",
+			"invalid dont-have message",
 			"",
 			"",
 			"",

src/peer_connection.cpp

@@ -1746,6 +1746,65 @@ namespace libtorrent
 		}
 	}
 
+	// -----------------------------
+	// -------- DONT HAVE ----------
+	// -----------------------------
+
+	void peer_connection::incoming_dont_have(int index)
+	{
+		INVARIANT_CHECK;
+
+		boost::shared_ptr<torrent> t = m_torrent.lock();
+		TORRENT_ASSERT(t);
+
+#ifndef TORRENT_DISABLE_EXTENSIONS
+		for (extension_list_t::iterator i = m_extensions.begin()
+			, end(m_extensions.end()); i != end; ++i)
+		{
+			if ((*i)->on_dont_have(index)) return;
+		}
+#endif
+
+		if (is_disconnecting()) return;
+
+#ifdef TORRENT_VERBOSE_LOGGING
+		peer_log("<== DONT_HAVE [ piece: %d ]", index);
+#endif
+
+		if (is_disconnecting()) return;
+
+		// if we got an invalid message, abort
+		if (index >= int(m_have_piece.size()) || index < 0)
+		{
+			disconnect(errors::invalid_dont_have, 2);
+			return;
+		}
+
+		if (!m_have_piece[index])
+		{
+#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
+			peer_log("   got redundant DONT_HAVE message for index: %d", index);
+#endif
+			return;
+		}
+
+		bool was_seed = is_seed();
+		m_have_piece.clear_bit(index);
+		TORRENT_ASSERT(m_num_pieces > 0);
+		--m_num_pieces;
+
+		// only update the piece_picker if
+		// we have the metadata and if
+		// we're not a seed (in which case
+		// we won't have a piece picker)
+		if (!t->valid_metadata()) return;
+
+		t->peer_lost(index);
+
+		if (was_seed)
+			t->get_policy().set_seed(m_peer_info, false);
+	}
+
 	// -----------------------------
 	// --------- BITFIELD ----------
 	// -----------------------------