From 9ed60479ce9a3a35bfc9f62f42d989a0320fa549 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sun, 7 Oct 2012 23:34:44 +0000
Subject: [PATCH] merged udp socket fix from RC_0_16

---
 ChangeLog                                |  1 +
 include/libtorrent/aux_/session_impl.hpp |  2 +-
 src/session_impl.cpp                     | 13 ++++++++++---
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 144db9c5a..26f7823c3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,7 @@
 	* fix uTP edge case where udp socket buffer fills up
 	* fix nagle implementation in uTP
 
+	* try harder to bind the udp socket (uTP, DHT, UDP-trackers, LSD) to the same port as TCP
 	* relax file timestamp requirements for accepting resume data
 	* fix performance issue in web seed downloader (coalescing of blocks sometimes wouldn't work)
 	* web seed fixes (better support for torrents without trailing / in web seeds)
diff --git a/include/libtorrent/aux_/session_impl.hpp b/include/libtorrent/aux_/session_impl.hpp
index aeebdfd10..f3fd8b89e 100644
--- a/include/libtorrent/aux_/session_impl.hpp
+++ b/include/libtorrent/aux_/session_impl.hpp
@@ -769,7 +769,7 @@ namespace libtorrent
 			boost::shared_ptr<socket_type> m_i2p_listen_socket;
 #endif
 
-			void setup_listener(listen_socket_t* s, tcp::endpoint ep, int retries
+			void setup_listener(listen_socket_t* s, tcp::endpoint ep, int& retries
 				, bool v6_only, int flags, error_code& ec);
 
 			// the proxy used for bittorrent
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index 586039673..88a7df04a 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -2101,7 +2101,7 @@ namespace aux {
 	}
 
 	void session_impl::setup_listener(listen_socket_t* s, tcp::endpoint ep
-		, int retries, bool v6_only, int flags, error_code& ec)
+		, int& retries, bool v6_only, int flags, error_code& ec)
 	{
 		s->sock.reset(new socket_acceptor(m_io_service));
 		s->sock->open(ep.protocol(), ec);
@@ -2201,6 +2201,8 @@ namespace aux {
 	{
 		TORRENT_ASSERT(is_network_thread());
 
+retry:
+
 		// close the open listen sockets
 		m_listen_sockets.clear();
 		m_incoming_connection = false;
@@ -2330,14 +2332,19 @@ namespace aux {
 		m_udp_socket.bind(udp::endpoint(m_listen_interface.address(), m_listen_interface.port()), ec);
 		if (ec)
 		{
-			if (m_alerts.should_post<listen_failed_alert>())
-				m_alerts.post_alert(listen_failed_alert(m_listen_interface, ec));
 #if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
 			char msg[200];
 			snprintf(msg, sizeof(msg), "cannot bind to UDP interface \"%s\": %s"
 				, print_endpoint(m_listen_interface).c_str(), ec.message().c_str());
 			(*m_logger) << msg << "\n";
 #endif
+			if (m_listen_port_retries > 0)
+			{
+				m_listen_interface.port(m_listen_interface.port() + 1);
+				goto retry;
+			}
+			if (m_alerts.should_post<listen_failed_alert>())
+				m_alerts.post_alert(listen_failed_alert(m_listen_interface, ec));
 		}
 		else
 		{