extend plugin API to allow hooking when peers are added to the peer list

docs/libtorrent_plugins.rst

@@ -119,6 +119,16 @@ The synopsis for ``torrent_plugin`` follows::
 		virtual bool on_resume();
 
 		virtual void on_files_checked();
+
+		virtual void on_state(int s);
+
+		enum flags_t {
+			first_time = 1,
+			filtered = 2
+		};
+
+		virtual void on_add_peer(tcp::endpoint const& ip
+			, int src, int flags);
 	};
 
 This is the base class for a torrent_plugin. Your derived class is (if added
@@ -206,6 +216,44 @@ checked. If there are no files to check, this function is called immediately.
 i.e. This function is always called when the torrent is in a state where it
 can start downloading.
 
+on_files_checked()
+------------------
+
+::
+
+		enum flags_t {
+			first_time = 1,
+			filtered = 2
+		};
+
+		virtual void on_add_peer(tcp::endpoint const& ip
+			, int src, int flags);
+
+This function is called whenever we hear about a peer from any peer source,
+such as the tracker, PEX, DHT or Local peer discovery.
+
+``src`` is a bitmask of ``peer_info::peer_source_flags``::
+
+	enum peer_source_flags
+	{
+		tracker = 0x1,
+		dht = 0x2,
+		pex = 0x4,
+		lsd = 0x8,
+		resume_data = 0x10,
+		incoming = 0x20
+	};
+
+``flags`` is a bitmask of::
+
+		enum flags_t {
+			first_time = 1,
+			filtered = 2
+		};
+
+If the ``filtered`` flag is set, it means the peer wasn't added to the
+peer list because of and IP filter, port filter, reserved ports filter.
+
 
 peer_plugin
 ===========

include/libtorrent/extensions.hpp

@@ -48,6 +48,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <vector>
 #include "libtorrent/config.hpp"
 #include "libtorrent/buffer.hpp"
+#include "libtorrent/socket.hpp"
 
 namespace libtorrent
 {
@@ -119,6 +120,21 @@ namespace libtorrent
 		// the state is one of torrent_status::state_t
 		// enum members
 		virtual void on_state(int s) {}
+
+		// called every time policy::add_peer is called
+		// src is a bitmask of which sources this peer
+		// has been seen from. flags is a bitmask of:
+
+		enum flags_t {
+			// this is the first time we see this peer
+			first_time = 1,
+			// this peer was not added because it was
+			// filtered by the IP filter
+			filtered = 2
+		};
+
+		virtual void on_add_peer(tcp::endpoint const& ip
+			, int src, int flags) {}
 	};
 
 	struct TORRENT_EXPORT peer_plugin

include/libtorrent/torrent.hpp

@@ -131,6 +131,7 @@ namespace libtorrent
 		void add_extension(boost::shared_ptr<torrent_plugin>);
 		void add_extension(boost::function<boost::shared_ptr<torrent_plugin>(torrent*, void*)> const& ext
 			, void* userdata);
+		void notify_extension_add_peer(tcp::endpoint const& ip, int src, int flags);
 #endif
 
 #ifdef TORRENT_DEBUG

src/policy.cpp

@@ -56,6 +56,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/broadcast_socket.hpp"
 #include "libtorrent/peer_info.hpp"
 #include "libtorrent/random.hpp"
+#include "libtorrent/extensions.hpp"
 
 #ifdef TORRENT_DEBUG
 #include "libtorrent/bt_peer_connection.hpp"
@@ -1207,6 +1208,9 @@ namespace libtorrent
 		{
 			if (ses.m_alerts.should_post<peer_blocked_alert>())
 				ses.m_alerts.post_alert(peer_blocked_alert(m_torrent->get_handle(), remote.address()));
+#ifndef TORRENT_DISABLE_EXTENSIONS
+			m_torrent->notify_extension_add_peer(remote, src, torrent_plugin::filtered);
+#endif
 			return 0;
 		}
 
@@ -1214,6 +1218,9 @@ namespace libtorrent
 		{
 			if (ses.m_alerts.should_post<peer_blocked_alert>())
 				ses.m_alerts.post_alert(peer_blocked_alert(m_torrent->get_handle(), remote.address()));
+#ifndef TORRENT_DISABLE_EXTENSIONS
+			m_torrent->notify_extension_add_peer(remote, src, torrent_plugin::filtered);
+#endif
 			return 0;
 		}
 
@@ -1223,6 +1230,9 @@ namespace libtorrent
 		{
 			if (ses.m_alerts.should_post<peer_blocked_alert>())
 				ses.m_alerts.post_alert(peer_blocked_alert(m_torrent->get_handle(), remote.address()));
+#ifndef TORRENT_DISABLE_EXTENSIONS
+			m_torrent->notify_extension_add_peer(remote, src, torrent_plugin::filtered);
+#endif
 			return 0;
 		}
 
@@ -1290,11 +1300,17 @@ namespace libtorrent
 				m_torrent->session().m_ipv4_peer_pool.free((ipv4_peer*)p);
 				return 0;
 			}
+#ifndef TORRENT_DISABLE_EXTENSIONS
+			m_torrent->notify_extension_add_peer(remote, src, torrent_plugin::first_time);
+#endif
 		}
 		else
 		{
 			p = *iter;
 			update_peer(p, src, flags, remote, 0);
+#ifndef TORRENT_DISABLE_EXTENSIONS
+			m_torrent->notify_extension_add_peer(remote, src, 0);
+#endif
 		}
 
 		return p;

src/torrent.cpp

@@ -7375,6 +7375,20 @@ namespace libtorrent
 #endif
 	}
 
+#ifndef TORRENT_DISABLE_EXTENSIONS
+	void torrent::notify_extension_add_peer(tcp::endpoint const& ip
+		, int src, int flags)
+	{
+		for (extension_list_t::iterator i = m_extensions.begin()
+			, end(m_extensions.end()); i != end; ++i)
+		{
+			TORRENT_TRY {
+				(*i)->on_add_peer(ip, src, flags);
+			} TORRENT_CATCH (std::exception&) {}
+		}
+	}
+#endif
+
 	void torrent::status(torrent_status* st, boost::uint32_t flags)
 	{
 		INVARIANT_CHECK;