From 60af1aa4516e701a024e76413d017f494405e1b8 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Thu, 23 Jan 2014 03:31:36 +0000
Subject: [PATCH] update peer ranks when our external IP changes

---
 include/libtorrent/policy.hpp  | 7 ++++++-
 include/libtorrent/torrent.hpp | 2 ++
 src/policy.cpp                 | 8 +++++++-
 src/session_impl.cpp           | 6 ++++++
 src/torrent.cpp                | 5 +++++
 5 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/include/libtorrent/policy.hpp b/include/libtorrent/policy.hpp
index 42901f8ae..d015ecc5c 100644
--- a/include/libtorrent/policy.hpp
+++ b/include/libtorrent/policy.hpp
@@ -105,7 +105,8 @@ namespace libtorrent
 	// calculate the priority of a peer based on its address. One of the
 	// endpoint should be our own. The priority is symmetric, so it doesn't
 	// matter which is which
-	TORRENT_EXTRA_EXPORT boost::uint32_t peer_priority(tcp::endpoint e1, tcp::endpoint e2);
+	TORRENT_EXTRA_EXPORT boost::uint32_t peer_priority(
+		tcp::endpoint e1, tcp::endpoint e2);
 
 	void request_a_block(torrent& t, peer_connection& c);
 
@@ -147,6 +148,10 @@ namespace libtorrent
 
 		void set_seed(policy::peer* p, bool s);
 
+		// this clears all cached peer priorities. It's called when
+		// our external IP changes
+		void clear_peer_prio();
+
 #if TORRENT_USE_ASSERTS
 		bool has_connection(const peer_connection* p);
 #endif
diff --git a/include/libtorrent/torrent.hpp b/include/libtorrent/torrent.hpp
index c7fba0c78..67c1ee9c1 100644
--- a/include/libtorrent/torrent.hpp
+++ b/include/libtorrent/torrent.hpp
@@ -216,6 +216,8 @@ namespace libtorrent
 		void abort();
 		bool is_aborted() const { return m_abort; }
 
+		void new_external_ip();
+
 		torrent_status::state_t state() const { return (torrent_status::state_t)m_state; }
 		void set_state(torrent_status::state_t s);
 
diff --git a/src/policy.cpp b/src/policy.cpp
index 79113da4e..7fddd23b2 100644
--- a/src/policy.cpp
+++ b/src/policy.cpp
@@ -447,6 +447,13 @@ namespace libtorrent
 		, m_finished(false)
 	{ TORRENT_ASSERT(t); }
 
+	void policy::clear_peer_prio()
+	{
+		for (peers_t::iterator i = m_peers.begin()
+			, end(m_peers.end()); i != end; ++i)
+			(*i)->peer_rank = 0;
+	}
+
 	// disconnects and removes all peers that are now filtered
 	void policy::ip_filter_updated()
 	{
@@ -1903,7 +1910,6 @@ namespace libtorrent
 	// TOOD: pass in both an IPv6 and IPv4 address here
 	boost::uint32_t policy::peer::rank(external_ip const& external, int external_port) const
 	{
-//TODO 3: how do we deal with our external address changing? Pass in a force-update maybe? and keep a version number in policy
 		if (peer_rank == 0)
 			peer_rank = peer_priority(
 				tcp::endpoint(external.external_address(this->address()), external_port)
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index e2dff337a..813e61ef1 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -6241,6 +6241,12 @@ retry:
 		if (m_alerts.should_post<external_ip_alert>())
 			m_alerts.post_alert(external_ip_alert(ip));
 
+		for (torrent_map::iterator i = m_torrents.begin()
+			, end(m_torrents.end()); i != end; ++i)
+		{
+			i->second->new_external_ip();
+		}
+
 		// since we have a new external IP now, we need to
 		// restart the DHT with a new node ID
 #ifndef TORRENT_DISABLE_DHT
diff --git a/src/torrent.cpp b/src/torrent.cpp
index d4d36b215..cafbc5fae 100644
--- a/src/torrent.cpp
+++ b/src/torrent.cpp
@@ -8594,6 +8594,11 @@ namespace libtorrent
 		}
 	}
 	
+	void torrent::new_external_ip()
+	{
+		m_policy.clear_peer_prio();
+	}
+
 	void torrent::set_state(torrent_status::state_t s)
 	{
 		TORRENT_ASSERT(m_ses.is_network_thread());