Merge pull request #1600

1c4d65c0 Rename method to get_random_gray_peer (Miguel Herranz)
03a54ee0 Fix logging that broke after rebasing (Miguel Herranz)
6bdd3a59 Use set_peer_just_seen to keep last_seen updated (Miguel Herranz)
82dbeedd Add gray peer list housekeeping system (Miguel Herranz)

src/p2p/net_node.h

@@ -229,6 +229,9 @@ namespace nodetool
 
     bool has_too_many_connections(const uint32_t ip);
 
+    bool check_connection_and_handshake_with_peer(const net_address& na, uint64_t last_seen_stamp);
+    bool gray_peerlist_housekeeping();
+
     void kill() { ///< will be called e.g. from deinit()
       _info("Killing the net_node");
       is_closing = true;
@@ -289,6 +292,7 @@ namespace nodetool
     epee::math_helper::once_a_time_seconds<P2P_DEFAULT_HANDSHAKE_INTERVAL> m_peer_handshake_idle_maker_interval;
     epee::math_helper::once_a_time_seconds<1> m_connections_maker_interval;
     epee::math_helper::once_a_time_seconds<60*30, false> m_peerlist_store_interval;
+    epee::math_helper::once_a_time_seconds<60> m_gray_peerlist_housekeeping_interval;
 
     std::string m_bind_ip;
     std::string m_port;

src/p2p/net_node.inl

@@ -926,6 +926,50 @@ namespace nodetool
     return true;
   }
 
+  template<class t_payload_net_handler>
+  bool node_server<t_payload_net_handler>::check_connection_and_handshake_with_peer(const net_address& na, uint64_t last_seen_stamp)
+  {
+    LOG_PRINT_L1("Connecting to " << epee::string_tools::get_ip_string_from_int32(na.ip)  << ":"
+                                  << epee::string_tools::num_to_string_fast(na.port) << "(last_seen: "
+                                  << (last_seen_stamp ? epee::misc_utils::get_time_interval_string(time(NULL) - last_seen_stamp):"never")
+                                  << ")...");
+
+    typename net_server::t_connection_context con = AUTO_VAL_INIT(con);
+    bool res = m_net_server.connect(epee::string_tools::get_ip_string_from_int32(na.ip),
+                                    epee::string_tools::num_to_string_fast(na.port),
+                                    m_config.m_net_config.connection_timeout,
+                                    con);
+
+    if (!res) {
+      bool is_priority = is_priority_node(na);
+
+      LOG_PRINT_CC_PRIORITY_NODE(is_priority, con, "Connect failed to "
+              << epee::string_tools::get_ip_string_from_int32(na.ip)
+              << ":" << epee::string_tools::num_to_string_fast(na.port));
+
+      return false;
+    }
+
+    peerid_type pi = AUTO_VAL_INIT(pi);
+    res = do_handshake_with_peer(pi, con, true);
+
+    if (!res) {
+      bool is_priority = is_priority_node(na);
+
+      LOG_PRINT_CC_PRIORITY_NODE(is_priority, con, "Failed to HANDSHAKE with peer "
+              << epee::string_tools::get_ip_string_from_int32(na.ip)
+              << ":" << epee::string_tools::num_to_string_fast(na.port));
+
+      return false;
+    }
+
+    m_net_server.get_config_object().close(con.m_connection_id);
+
+    LOG_DEBUG_CC(con, "CONNECTION HANDSHAKED OK AND CLOSED.");
+
+    return true;
+  }
+
 #undef LOG_PRINT_CC_PRIORITY_NODE
 
   //-----------------------------------------------------------------------------------
@@ -1097,6 +1141,7 @@ namespace nodetool
   {
     m_peer_handshake_idle_maker_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::peer_sync_idle_maker, this));
     m_connections_maker_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::connections_maker, this));
+    m_gray_peerlist_housekeeping_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::gray_peerlist_housekeeping, this));
     m_peerlist_store_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::store_config, this));
     return true;
   }
@@ -1704,4 +1749,30 @@ namespace nodetool
 
     return count > max_connections;
   }
+
+  template<class t_payload_net_handler>
+  bool node_server<t_payload_net_handler>::gray_peerlist_housekeeping()
+  {
+    peerlist_entry pe = AUTO_VAL_INIT(pe);
+
+    if (!m_peerlist.get_random_gray_peer(pe)) {
+        return false;
+    }
+
+    bool success = check_connection_and_handshake_with_peer(pe.adr, pe.last_seen);
+
+    if (!success) {
+      m_peerlist.remove_from_peer_gray(pe);
+
+      LOG_PRINT_L2("PEER EVICTED FROM GRAY PEER LIST IP address: " << epee::string_tools::get_ip_string_from_int32(pe.adr.ip) << " Peer ID: " << std::hex << pe.id);
+
+      return true;
+    }
+
+    m_peerlist.set_peer_just_seen(pe.id, pe.adr);
+
+    LOG_PRINT_L2("PEER PROMOTED TO WHITE PEER LIST IP address: " << epee::string_tools::get_ip_string_from_int32(pe.adr.ip) << " Peer ID: " << std::hex << pe.id);
+
+    return true;
+  }
 }

src/p2p/net_peerlist.h

@@ -81,6 +81,8 @@ namespace nodetool
     bool set_peer_just_seen(peerid_type peer, const net_address& addr);
     bool set_peer_unreachable(const peerlist_entry& pr);
     bool is_ip_allowed(uint32_t ip);
+    bool get_random_gray_peer(peerlist_entry& pe);
+    bool remove_from_peer_gray(const peerlist_entry& pe);
 
     
   private:
@@ -396,6 +398,50 @@ namespace nodetool
     return true;
   }
   //--------------------------------------------------------------------------------------------------
+  inline
+  bool peerlist_manager::get_random_gray_peer(peerlist_entry& pe)
+  {
+    TRY_ENTRY();
+
+    CRITICAL_REGION_LOCAL(m_peerlist_lock);
+
+    if (m_peers_gray.empty()) {
+      return false;
+    }
+
+    size_t x = crypto::rand<size_t>() % (m_peers_gray.size() + 1);
+    size_t res = (x * x * x) / (m_peers_gray.size() * m_peers_gray.size()); //parabola \/
+
+    LOG_PRINT_L3("Random gray peer index=" << res << "(x="<< x << ", max_index=" << m_peers_gray.size() << ")");
+
+    peers_indexed::index<by_time>::type& by_time_index = m_peers_gray.get<by_time>();
+    pe = *epee::misc_utils::move_it_backward(--by_time_index.end(), res);
+
+    return true;
+
+    CATCH_ENTRY_L0("peerlist_manager::get_random_gray_peer()", false);
+    return true;
+  }
+  //--------------------------------------------------------------------------------------------------
+  inline
+  bool peerlist_manager::remove_from_peer_gray(const peerlist_entry& pe)
+  {
+    TRY_ENTRY();
+
+    CRITICAL_REGION_LOCAL(m_peerlist_lock);
+
+    peers_indexed::index_iterator<by_addr>::type iterator = m_peers_gray.get<by_addr>().find(pe.adr);
+
+    if (iterator != m_peers_gray.get<by_addr>().end()) {
+      m_peers_gray.erase(iterator);
+    }
+
+    return true;
+
+    CATCH_ENTRY_L0("peerlist_manager::remove_from_peer_gray()", false);
+    return true;
+  }
+    //--------------------------------------------------------------------------------------------------
 }
 
 BOOST_CLASS_VERSION(nodetool::peerlist_manager, CURRENT_PEERLIST_STORAGE_ARCHIVE_VER)