updated udp_socket error handling

include/libtorrent/alert_types.hpp

@@ -364,6 +364,21 @@ namespace libtorrent
 		{ return std::auto_ptr<alert>(new metadata_received_alert(*this)); }
 	};
 
+	struct TORRENT_EXPORT udp_error_alert: alert
+	{
+		udp_error_alert(
+			udp::endpoint const& ep
+			, std::string const& msg)
+			: alert(alert::info, msg)
+			, endpoint(ep)
+		{}
+
+		udp::endpoint endpoint;
+
+		virtual std::auto_ptr<alert> clone() const
+		{ return std::auto_ptr<alert>(new udp_error_alert(*this)); }
+	};
+
 	struct TORRENT_EXPORT listen_failed_alert: alert
 	{
 		listen_failed_alert(

include/libtorrent/aux_/session_impl.hpp

@@ -509,7 +509,8 @@ namespace libtorrent
 
 			udp_socket m_dht_socket;
 
-			void on_receive_udp(udp::endpoint const& ep, char const* buf, int len);
+			void on_receive_udp(asio::error_code const& e
+				, udp::endpoint const& ep, char const* buf, int len);
 #endif
 
 #ifndef TORRENT_DISABLE_ENCRYPTION

include/libtorrent/udp_socket.hpp

@@ -46,7 +46,8 @@ namespace libtorrent
 	class udp_socket
 	{
 	public:
-		typedef boost::function<void(udp::endpoint const&, char const* buf, int size)> callback_t;
+		typedef boost::function<void(asio::error_code const& ec
+			, udp::endpoint const&, char const* buf, int size)> callback_t;
 
 		udp_socket(asio::io_service& ios, callback_t const& c, connection_queue& cc);
 
@@ -80,7 +81,7 @@ namespace libtorrent
 		void connect2(asio::error_code const& e);
 
 		void wrap(udp::endpoint const& ep, char const* p, int len, asio::error_code& ec);
-		void unwrap(char const* buf, int size);
+		void unwrap(asio::error_code const& e, char const* buf, int size);
 
 		udp::socket m_ipv4_sock;
 		udp::socket m_ipv6_sock;

include/libtorrent/udp_tracker_connection.hpp

@@ -92,7 +92,8 @@ namespace libtorrent
 		void name_lookup(asio::error_code const& error, udp::resolver::iterator i);
 		void timeout(asio::error_code const& error);
 
-		void on_receive(udp::endpoint const& ep, char const* buf, int size);
+		void on_receive(asio::error_code const& e, udp::endpoint const& ep
+			, char const* buf, int size);
 		void on_connect_response(char const* buf, int size);
 		void on_announce_response(char const* buf, int size);
 		void on_scrape_response(char const* buf, int size);

src/udp_socket.cpp

@@ -39,7 +39,37 @@ void udp_socket::send(udp::endpoint const& ep, char const* p, int len, asio::err
 
 void udp_socket::on_read(udp::socket* s, asio::error_code const& e, std::size_t bytes_transferred)
 {
-	if (e) return;
+	if (e)
+	{
+#ifndef BOOST_NO_EXCEPTIONS
+		try {
+#endif
+		if (s == &m_ipv4_sock)
+			m_callback(e, m_v4_ep, 0, 0);
+		else
+			m_callback(e, m_v6_ep, 0, 0);
+#ifndef BOOST_NO_EXCEPTIONS
+		} catch(std::exception&) {}
+#endif
+
+		// don't stop listening on recoverable errors
+		if (e != asio::error::host_unreachable
+			&& e != asio::error::fault
+			&& e != asio::error::connection_reset
+			&& e != asio::error::connection_refused
+			&& e != asio::error::connection_aborted
+			&& e != asio::error::message_size)
+			return;
+
+		if (s == &m_ipv4_sock)
+			s->async_receive_from(asio::buffer(m_v4_buf, sizeof(m_v4_buf))
+				, m_v4_ep, boost::bind(&udp_socket::on_read, this, s, _1, _2));
+		else
+			s->async_receive_from(asio::buffer(m_v6_buf, sizeof(m_v6_buf))
+				, m_v6_ep, boost::bind(&udp_socket::on_read, this, s, _1, _2));
+
+		return;
+	}
 	if (!m_callback) return;
 
 	if (s == &m_ipv4_sock)
@@ -49,9 +79,9 @@ void udp_socket::on_read(udp::socket* s, asio::error_code const& e, std::size_t
 #endif
 
 		if (m_tunnel_packets && m_v4_ep == m_proxy_addr)
-			unwrap(m_v4_buf, bytes_transferred);
+			unwrap(e, m_v4_buf, bytes_transferred);
 		else
-			m_callback(m_v4_ep, m_v4_buf, bytes_transferred);
+			m_callback(e, m_v4_ep, m_v4_buf, bytes_transferred);
 
 #ifndef BOOST_NO_EXCEPTIONS
 		} catch(std::exception&) {}
@@ -66,9 +96,9 @@ void udp_socket::on_read(udp::socket* s, asio::error_code const& e, std::size_t
 #endif
 
 		if (m_tunnel_packets && m_v6_ep == m_proxy_addr)
-			unwrap(m_v6_buf, bytes_transferred);
+			unwrap(e, m_v6_buf, bytes_transferred);
 		else
-			m_callback(m_v6_ep, m_v6_buf, bytes_transferred);
+			m_callback(e, m_v6_ep, m_v6_buf, bytes_transferred);
 
 #ifndef BOOST_NO_EXCEPTIONS
 		} catch(std::exception&) {}
@@ -102,7 +132,7 @@ void udp_socket::wrap(udp::endpoint const& ep, char const* p, int len, asio::err
 }
 
 // unwrap the UDP packet from the SOCKS5 header
-void udp_socket::unwrap(char const* buf, int size)
+void udp_socket::unwrap(asio::error_code const& e, char const* buf, int size)
 {
 	using namespace libtorrent::detail;
 
@@ -128,7 +158,6 @@ void udp_socket::unwrap(char const* buf, int size)
 	{
 		// IPv6
 		TORRENT_ASSERT(false && "not supported yet");
-	
 	}
 	else
 	{
@@ -136,7 +165,7 @@ void udp_socket::unwrap(char const* buf, int size)
 		return;
 	}
 
-	m_callback(sender, p, size - (p - buf));
+	m_callback(e, sender, p, size - (p - buf));
 }
 
 void udp_socket::close()

src/udp_tracker_connection.cpp

@@ -84,7 +84,7 @@ namespace libtorrent
 		: tracker_connection(man, req, ios, bind_infc, c)
 		, m_man(man)
 		, m_name_lookup(ios)
-		, m_socket(ios, boost::bind(&udp_tracker_connection::on_receive, this, _1, _2, _3), cc)
+		, m_socket(ios, boost::bind(&udp_tracker_connection::on_receive, this, _1, _2, _3, _4), cc)
 		, m_transaction_id(0)
 		, m_connection_id(0)
 		, m_settings(stn)
@@ -185,7 +185,8 @@ namespace libtorrent
 		tracker_connection::close();
 	}
 
-	void udp_tracker_connection::on_receive(udp::endpoint const& ep, char const* buf, int size)
+	void udp_tracker_connection::on_receive(asio::error_code const& e
+		, udp::endpoint const& ep, char const* buf, int size)
 	{
 		// ignore resposes before we've sent any requests
 		if (m_state == action_error) return;
@@ -194,6 +195,8 @@ namespace libtorrent
 
 		// ignore packet not sent from the tracker
 		if (m_target != ep) return;
+		
+		if (e) fail(-1, e.message().c_str());
 
 #if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
 		boost::shared_ptr<request_callback> cb = requester();