From 096ce54faea0126b4ce0028ce04c3baebebbd9fc Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Sat, 11 Nov 2017 13:39:43 +0100
Subject: [PATCH] fix issue where new listen sockets would not be opened when
 leaving force_proxy mode

---
 ChangeLog                   |  1 +
 simulation/test_session.cpp | 50 +++++++++++++++++++++++++++++++++++++
 src/session_impl.cpp        | 21 +++++++++++++++-
 3 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 1e3af50e9..aefc6bc1f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,5 @@
 
+	* fix listen socket issue when disabling "force_proxy" mode
 	* fix full allocation failure on APFS
 
 1.1.5 release
diff --git a/simulation/test_session.cpp b/simulation/test_session.cpp
index 7c889687c..df5f36f80 100644
--- a/simulation/test_session.cpp
+++ b/simulation/test_session.cpp
@@ -35,6 +35,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "utils.hpp"
 #include "libtorrent/session.hpp"
 #include "libtorrent/socket.hpp"
+#include "libtorrent/alert_types.hpp"
 #include "simulator/simulator.hpp"
 #include "simulator/utils.hpp" // for timer
 #include "settings.hpp"
@@ -64,3 +65,52 @@ TORRENT_TEST(seed_mode)
 		});
 }
 
+TORRENT_TEST(force_proxy)
+{
+	// setup the simulation
+	sim::default_config network_cfg;
+	sim::simulation sim{network_cfg};
+	std::unique_ptr<sim::asio::io_service> ios{new sim::asio::io_service(sim
+		, address_v4::from_string("50.0.0.1"))};
+	lt::session_proxy zombie;
+
+	lt::settings_pack pack = settings();
+	pack.set_bool(settings_pack::force_proxy, true);
+	// create session
+	std::shared_ptr<lt::session> ses = std::make_shared<lt::session>(pack, *ios);
+
+	// disable force proxy in 3 seconds (this should make us open up listen
+	// sockets)
+	sim::timer t1(sim, lt::seconds(3), [&](boost::system::error_code const& ec)
+	{
+		lt::settings_pack p;
+		p.set_bool(settings_pack::force_proxy, false);
+		ses->apply_settings(p);
+	});
+
+	int num_listen_tcp = 0;
+	int num_listen_udp = 0;
+	print_alerts(*ses, [&](lt::session& ses, lt::alert const* a) {
+		if (auto la = alert_cast<listen_succeeded_alert>(a))
+		{
+			if (la->sock_type == listen_succeeded_alert::tcp)
+				++num_listen_tcp;
+			else if (la->sock_type == listen_succeeded_alert::udp)
+				++num_listen_udp;
+		}
+	});
+
+	// run for 10 seconds.
+	sim::timer t2(sim, lt::seconds(10), [&](boost::system::error_code const& ec)
+	{
+		fprintf(stderr, "shutting down\n");
+		// shut down
+		zombie = ses->abort();
+		ses.reset();
+	});
+	sim.run();
+
+	TEST_EQUAL(num_listen_tcp, 1);
+	TEST_EQUAL(num_listen_udp, 1);
+}
+
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index cea3ca98a..9534fa7ab 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -1673,6 +1673,9 @@ namespace aux {
 			(pack.has_val(settings_pack::ssl_listen)
 				&& pack.get_int(settings_pack::ssl_listen)
 					!= m_settings.get_int(settings_pack::ssl_listen))
+			|| (pack.has_val(settings_pack::force_proxy)
+				&& !pack.get_bool(settings_pack::force_proxy)
+				&& m_settings.get_bool(settings_pack::force_proxy))
 			|| (pack.has_val(settings_pack::listen_interfaces)
 				&& pack.get_str(settings_pack::listen_interfaces)
 					!= m_settings.get_str(settings_pack::listen_interfaces));
@@ -1882,6 +1885,12 @@ retry:
 		m_stats_counters.set_value(counters::has_incoming_connections, 0);
 		ec.clear();
 
+		if (m_settings.get_bool(settings_pack::force_proxy))
+		{
+			// in force-proxy mode, we don't open any listen sockets
+			return;
+		}
+
 		if (m_abort) return;
 
 		m_ipv6_interface = tcp::endpoint();
@@ -6493,7 +6502,17 @@ retry:
 		m_ssl_udp_socket.set_force_proxy(m_settings.get_bool(settings_pack::force_proxy));
 #endif
 
-		if (!m_settings.get_bool(settings_pack::force_proxy)) return;
+		if (!m_settings.get_bool(settings_pack::force_proxy))
+		{
+#ifndef TORRENT_DISABLE_LOGGING
+			session_log("force-proxy disabled");
+#endif
+			return;
+		}
+
+#ifndef TORRENT_DISABLE_LOGGING
+		session_log("force-proxy enabled");
+#endif
 
 		// enable force_proxy mode. We don't want to accept any incoming
 		// connections, except through a proxy.