Commit ce6209ce authored by Nick Mathewson's avatar Nick Mathewson 🤹
Browse files

Add a periodic event to become dormant. 

This event makes us become dormant if we have seen no activity in a
long time.

Note that being any kind of a server, or running an onion service,
always counts as being active.

Note that right now, just having an open stream that Tor
did not open on its own (for a directory request) counts as "being
active", so if you have an idle ssh connection, that will keep Tor
from becoming dormant.

Many of the features here should become configurable; I'd like
feedback on which.
parent 2c15b653

src/core/mainloop/connection.c

+10 −0
Original line number Diff line number Diff line
@@ -4429,6 +4429,16 @@ connection_get_by_type_state(int type, int state) 
  CONN_GET_TEMPLATE(conn, conn->type == type && conn->state == state);

}



/**

 * Return a connection of type <b>type</b> that is not an internally linked

 * connection, and is not marked for close.

 **/

connection_t *

connection_get_by_type_nonlinked(int type)

{

  CONN_GET_TEMPLATE(conn, conn->type == type && !conn->linked);

}



/** Return a connection of type <b>type</b> that has rendquery equal

 * to <b>rendquery</b>, and that is not marked for close. If state

 * is non-zero, conn must be of that state too.

src/core/mainloop/connection.h

+1 −0
Original line number Diff line number Diff line
@@ -240,6 +240,7 @@ size_t connection_get_outbuf_len(connection_t *conn); 
connection_t *connection_get_by_global_id(uint64_t id);



connection_t *connection_get_by_type(int type);

connection_t *connection_get_by_type_nonlinked(int type);

MOCK_DECL(connection_t *,connection_get_by_type_addr_port_purpose,(int type,

                                                  const tor_addr_t *addr,

                                                  uint16_t port, int purpose));

src/core/mainloop/mainloop.c

+50 −0
Original line number Diff line number Diff line
@@ -1367,6 +1367,7 @@ CALLBACK(write_bridge_ns); 
CALLBACK(write_stats_file);

CALLBACK(control_per_second_events);

CALLBACK(second_elapsed);

CALLBACK(check_network_participation);



#undef CALLBACK
@@ -1396,6 +1397,7 @@ STATIC periodic_event_item_t periodic_events[] = { 
  CALLBACK(fetch_networkstatus, NET_PARTICIPANT, 0),

  CALLBACK(launch_descriptor_fetches, NET_PARTICIPANT, FL(NEED_NET)),

  CALLBACK(rotate_x509_certificate, NET_PARTICIPANT, 0),

  CALLBACK(check_network_participation, NET_PARTICIPANT, 0),



  /* We need to do these if we're participating in the Tor network, and

   * immediately before we stop. */
@@ -1998,6 +2000,54 @@ add_entropy_callback(time_t now, const or_options_t *options) 
  return ENTROPY_INTERVAL;

}



/** Periodic callback: if there has been no network usage in a while,

 * enter a dormant state. */

static int

check_network_participation_callback(time_t now, const or_options_t *options)

{

  /* If we're a server, we can't become dormant. */

  if (server_mode(options)) {

    goto found_activity;

  }



  /* If we're running an onion service, we can't become dormant. */

  /* XXXX this would be nice to change, so that we can be dormant with a

   * service. */

  if (hs_service_get_num_services() || rend_num_services()) {

    goto found_activity;

  }



  /* XXXX Add an option to never become dormant. */



  /* If we have any currently open entry streams other than "linked"

   * connections used for directory requests, those count as user activity.

   */

  /* XXXX make this configurable? */

  if (connection_get_by_type_nonlinked(CONN_TYPE_AP) != NULL) {

    goto found_activity;

  }



  /* XXXX Make this configurable? */

/** How often do we check whether we have had network activity? */

#define CHECK_PARTICIPATION_INTERVAL (5*60)



  /** Become dormant if there has been no user activity in this long. */

  /* XXXX make this configurable! */

#define BECOME_DORMANT_AFTER_INACTIVITY (24*60*60)

  if (get_last_user_activity_time() + BECOME_DORMANT_AFTER_INACTIVITY >= now) {

    log_notice(LD_GENERAL, "No user activity in a long time: becoming"

               " dormant.");

    set_network_participation(false);

    rescan_periodic_events(options);

  }



  return CHECK_PARTICIPATION_INTERVAL;



 found_activity:

  note_user_activity(now);

  return CHECK_PARTICIPATION_INTERVAL;

}



/**

 * Periodic callback: if we're an authority, make sure we test

 * the routers on the network for reachability.