improved natpmp, upnp and lsd

include/libtorrent/upnp.hpp

@@ -51,6 +51,8 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace libtorrent
 {
 
+bool is_local(address const& a);
+
 // int: external tcp port
 // int: external udp port
 // std::string: error message

src/lsd.cpp

@@ -72,36 +72,11 @@ lsd::~lsd() {}
 
 void lsd::rebind(address const& listen_interface)
 {
-	address_v4 local_ip;
+	address_v4 local_ip = address_v4::any();
-	if (listen_interface.is_v4() && listen_interface != address_v4::from_string("0.0.0.0"))
+	if (listen_interface.is_v4() && listen_interface != address_v4::any())
 	{
 		local_ip = listen_interface.to_v4();
 	}
-	else
-	{
-		// make a best guess of the interface we're using and its IP
-		udp::resolver r(m_socket.io_service());
-		udp::resolver::iterator i = r.resolve(udp::resolver::query(asio::ip::host_name(), "0"));
-		for (;i != udp::resolver_iterator(); ++i)
-		{
-			// ignore the loopback
-			if (i->endpoint().address() == address_v4((127 << 24) + 1)) continue;
-			// ignore non-IPv4 addresses
-			if (i->endpoint().address().is_v4()) break;
-		}
-
-		if (i == udp::resolver_iterator())
-		{
-	#if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
-			m_log << "local host name did not resolve to an IPv4 address. "
-				"disabling local service discovery" << std::endl;
-	#endif
-			m_disabled = true;
-			return;
-		}
-
-		local_ip = i->endpoint().address().to_v4();
-	}
 
 	try
 	{
@@ -123,8 +98,12 @@ void lsd::rebind(address const& listen_interface)
 #endif
 
 		m_socket.set_option(join_group(lsd_multicast_address));
-		m_socket.set_option(outbound_interface(address_v4()));
+		m_socket.set_option(outbound_interface(local_ip));
+#ifdef NDEBUG
 		m_socket.set_option(enable_loopback(false));
+#else
+		m_socket.set_option(enable_loopback(true));
+#endif
 		m_socket.set_option(hops(255));
 	}
 	catch (std::exception& e)

src/natpmp.cpp

@@ -42,6 +42,11 @@ using namespace libtorrent;
 
 enum { num_mappings = 2 };
 
+namespace libtorrent
+{
+	bool is_local(address const& a);
+}
+
 natpmp::natpmp(io_service& ios, address const& listen_interface, portmap_callback_t const& cb)
 	: m_callback(cb)
 	, m_currently_mapping(-1)
@@ -62,8 +67,8 @@ natpmp::natpmp(io_service& ios, address const& listen_interface, portmap_callbac
 
 void natpmp::rebind(address const& listen_interface) try
 {
-	address_v4 local;
+	address_v4 local = address_v4::any();
-	if (listen_interface.is_v4() && listen_interface != address_v4::from_string("0.0.0.0"))
+	if (listen_interface.is_v4() && listen_interface != address_v4::any())
 	{
 		local = listen_interface.to_v4();
 	}
@@ -76,30 +81,27 @@ void natpmp::rebind(address const& listen_interface) try
 		{
 			// ignore the loopback
 			if (i->endpoint().address() == address_v4((127 << 24) + 1)) continue;
+			// ignore addresses that are not on a local network
+			if (!is_local(i->endpoint().address())) continue;
 			// ignore non-IPv4 addresses
 			if (i->endpoint().address().is_v4()) break;
 		}
 
 		if (i == udp::resolver_iterator())
 		{
-			throw std::runtime_error("local host name did not resolve to an "
+			throw std::runtime_error("local host is probably not on a NATed "
-				"IPv4 address. disabling NAT-PMP");
+				"network. disabling NAT-PMP");
 		}
 
 		local = i->endpoint().address().to_v4();
 	}
 
-	m_socket.open(udp::v4());
-	m_socket.bind(udp::endpoint(local, 0));
-
 #if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
 	m_log << time_now_string()
 		<< " local ip: " << local.to_string() << std::endl;
 #endif
 
-	if ((local.to_ulong() & 0xff000000) != 0x0a000000
+	if (!is_local(local))
-		&& (local.to_ulong() & 0xfff00000) != 0xac100000
-		&& (local.to_ulong() & 0xffff0000) != 0xc0a80000)
 	{
 		// the local address seems to be an external
 		// internet address. Assume it is not behind a NAT
@@ -108,13 +110,13 @@ void natpmp::rebind(address const& listen_interface) try
 
 	m_disabled = false;
 
+	// assume the router is located on the local
+	// network as x.x.x.1
 	udp::endpoint nat_endpoint(
 		address_v4((local.to_ulong() & 0xffffff00) | 1), 5351);
 
 	if (nat_endpoint == m_nat_endpoint) return;
 
-	// assume the router is located on the local
-	// network as x.x.x.1
 	// TODO: find a better way to figure out the router IP
 	m_nat_endpoint = nat_endpoint;
 
@@ -122,6 +124,9 @@ void natpmp::rebind(address const& listen_interface) try
 	m_log << "assuming router is at: " << m_nat_endpoint.address().to_string() << std::endl;
 #endif
 
+	m_socket.open(udp::v4());
+	m_socket.bind(udp::endpoint(address_v4::any(), 0));
+
 	for (int i = 0; i < num_mappings; ++i)
 	{
 		if (m_mappings[i].local_port == 0)

src/upnp.cpp

@@ -52,6 +52,18 @@ using namespace libtorrent;
 address_v4 upnp::upnp_multicast_address;
 udp::endpoint upnp::upnp_multicast_endpoint;
 
+namespace libtorrent
+{
+	bool is_local(address const& a)
+	{
+		if (a.is_v6()) return false;
+		address_v4 a4 = a.to_v4();
+		return ((a4.to_ulong() & 0xff000000) == 0x0a000000
+			|| (a4.to_ulong() & 0xfff00000) == 0xac100000
+			|| (a4.to_ulong() & 0xffff0000) == 0xc0a80000);
+	}
+}
+
 upnp::upnp(io_service& ios, connection_queue& cc
 	, address const& listen_interface, std::string const& user_agent
 	, portmap_callback_t const& cb)
@@ -84,7 +96,7 @@ upnp::~upnp()
 
 void upnp::rebind(address const& listen_interface) try
 {
-	if (listen_interface.is_v4() && listen_interface != address_v4::from_string("0.0.0.0"))
+	if (listen_interface.is_v4() && listen_interface != address_v4::any())
 	{
 		m_local_ip = listen_interface.to_v4();
 	}
@@ -97,14 +109,16 @@ void upnp::rebind(address const& listen_interface) try
 		{
 			// ignore the loopback
 			if (i->endpoint().address() == address_v4((127 << 24) + 1)) continue;
+			// ignore addresses that are not on a local network
+			if (!is_local(i->endpoint().address())) continue;
 			// ignore non-IPv4 addresses
 			if (i->endpoint().address().is_v4()) break;
 		}
 
 		if (i == udp::resolver_iterator())
 		{
-			throw std::runtime_error("local host name did not resolve to an "
+			throw std::runtime_error("local host is probably not on a NATed "
-				"IPv4 address. disabling UPnP");
+				"network. disabling UPnP");
 		}
 
 		m_local_ip = i->endpoint().address().to_v4();
@@ -115,9 +129,7 @@ void upnp::rebind(address const& listen_interface) try
 		<< " local ip: " << m_local_ip.to_string() << std::endl;
 #endif
 
-	if ((m_local_ip.to_ulong() & 0xff000000) != 0x0a000000
+	if (!is_local(m_local_ip))
-		&& (m_local_ip.to_ulong() & 0xfff00000) != 0xac100000
-		&& (m_local_ip.to_ulong() & 0xffff0000) != 0xc0a80000)
 	{
 		// the local address seems to be an external
 		// internet address. Assume it is not behind a NAT