hibernate.c

关于tor匿名通信的源代码

       "this interval.  At the start of the interval, we expected to use "
       "about %lu KB per second. ("U64_FORMAT" bytes read so far, "
       U64_FORMAT" bytes written so far)",
       tbuf1, tbuf2,
       (unsigned long)n_seconds_active_in_interval,
       (unsigned long)(expected_bandwidth_usage*1024/60),
       U64_PRINTF_ARG(n_bytes_read_in_interval),
       U64_PRINTF_ARG(n_bytes_written_in_interval));
  }

  return 0;
}

/** Return true iff we have sent/received all the bytes we are willing
 * to send/receive this interval. */
static int
hibernate_hard_limit_reached(void)
{
  uint64_t hard_limit = get_options()->AccountingMax;
  if (!hard_limit)
    return 0;
  return n_bytes_read_in_interval >= hard_limit
    || n_bytes_written_in_interval >= hard_limit;
}

/** Return true iff we have sent/received almost all the bytes we are willing
 * to send/receive this interval. */
static int
hibernate_soft_limit_reached(void)
{
  uint64_t soft_limit = DBL_TO_U64(U64_TO_DBL(get_options()->AccountingMax)
                                   * .95);
  if (!soft_limit)
    return 0;
  return n_bytes_read_in_interval >= soft_limit
    || n_bytes_written_in_interval >= soft_limit;
}

/** Called when we get a SIGINT, or when bandwidth soft limit is
 * reached. Puts us into "loose hibernation": we don't accept new
 * connections, but we continue handling old ones. */
static void
hibernate_begin(hibernate_state_t new_state, time_t now)
{
  connection_t *conn;
  or_options_t *options = get_options();

  if (new_state == HIBERNATE_STATE_EXITING &&
      hibernate_state != HIBERNATE_STATE_LIVE) {
    log_notice(LD_GENERAL,"Sigint received %s; exiting now.",
               hibernate_state == HIBERNATE_STATE_EXITING ?
               "a second time" : "while hibernating");
    tor_cleanup();
    exit(0);
  }

  /* close listeners. leave control listener(s). */
  while ((conn = connection_get_by_type(CONN_TYPE_OR_LISTENER)) ||
         (conn = connection_get_by_type(CONN_TYPE_AP_LISTENER)) ||
         (conn = connection_get_by_type(CONN_TYPE_AP_TRANS_LISTENER)) ||
         (conn = connection_get_by_type(CONN_TYPE_AP_DNS_LISTENER)) ||
         (conn = connection_get_by_type(CONN_TYPE_AP_NATD_LISTENER)) ||
         (conn = connection_get_by_type(CONN_TYPE_DIR_LISTENER))) {
    log_info(LD_NET,"Closing listener type %d", conn->type);
    connection_mark_for_close(conn);
  }

  /* XXX kill intro point circs */
  /* XXX upload rendezvous service descriptors with no intro points */

  if (new_state == HIBERNATE_STATE_EXITING) {
    log_notice(LD_GENERAL,"Interrupt: will shut down in %d seconds. Interrupt "
               "again to exit now.", options->ShutdownWaitLength);
    shutdown_time = time(NULL) + options->ShutdownWaitLength;
  } else { /* soft limit reached */
    hibernate_end_time = interval_end_time;
  }

  hibernate_state = new_state;
  accounting_record_bandwidth_usage(now, get_or_state());

  or_state_mark_dirty(get_or_state(),
                      get_options()->AvoidDiskWrites ? now+600 : 0);
}

/** Called when we've been hibernating and our timeout is reached. */
static void
hibernate_end(hibernate_state_t new_state)
{
  tor_assert(hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH ||
             hibernate_state == HIBERNATE_STATE_DORMANT);

  /* listeners will be relaunched in run_scheduled_events() in main.c */
  log_notice(LD_ACCT,"Hibernation period ended. Resuming normal activity.");

  hibernate_state = new_state;
  hibernate_end_time = 0; /* no longer hibernating */
  stats_n_seconds_working = 0; /* reset published uptime */
}

/** A wrapper around hibernate_begin, for when we get SIGINT. */
void
hibernate_begin_shutdown(void)
{
  hibernate_begin(HIBERNATE_STATE_EXITING, time(NULL));
}

/** Return true iff we are currently hibernating. */
int
we_are_hibernating(void)
{
  return hibernate_state != HIBERNATE_STATE_LIVE;
}

/** If we aren't currently dormant, close all connections and become
 * dormant. */
static void
hibernate_go_dormant(time_t now)
{
  connection_t *conn;

  if (hibernate_state == HIBERNATE_STATE_DORMANT)
    return;
  else if (hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH)
    hibernate_state = HIBERNATE_STATE_DORMANT;
  else
    hibernate_begin(HIBERNATE_STATE_DORMANT, now);

  log_notice(LD_ACCT,"Going dormant. Blowing away remaining connections.");

  /* Close all OR/AP/exit conns. Leave dir conns because we still want
   * to be able to upload server descriptors so people know we're still
   * running, and download directories so we can detect if we're obsolete.
   * Leave control conns because we still want to be controllable.
   */
  while ((conn = connection_get_by_type(CONN_TYPE_OR)) ||
         (conn = connection_get_by_type(CONN_TYPE_AP)) ||
         (conn = connection_get_by_type(CONN_TYPE_EXIT))) {
    if (CONN_IS_EDGE(conn))
      connection_edge_end(TO_EDGE_CONN(conn), END_STREAM_REASON_HIBERNATING);
    log_info(LD_NET,"Closing conn type %d", conn->type);
    if (conn->type == CONN_TYPE_AP) /* send socks failure if needed */
      connection_mark_unattached_ap(TO_EDGE_CONN(conn),
                                    END_STREAM_REASON_HIBERNATING);
    else
      connection_mark_for_close(conn);
  }

  if (now < interval_wakeup_time)
    hibernate_end_time = interval_wakeup_time;
  else
    hibernate_end_time = interval_end_time;

  accounting_record_bandwidth_usage(now, get_or_state());

  or_state_mark_dirty(get_or_state(),
                      get_options()->AvoidDiskWrites ? now+600 : 0);
}

/** Called when hibernate_end_time has arrived. */
static void
hibernate_end_time_elapsed(time_t now)
{
  char buf[ISO_TIME_LEN+1];

  /* The interval has ended, or it is wakeup time.  Find out which. */
  accounting_run_housekeeping(now);
  if (interval_wakeup_time <= now) {
    /* The interval hasn't changed, but interval_wakeup_time has passed.
     * It's time to wake up and start being a server. */
    hibernate_end(HIBERNATE_STATE_LIVE);
    return;
  } else {
    /* The interval has changed, and it isn't time to wake up yet. */
    hibernate_end_time = interval_wakeup_time;
    format_iso_time(buf,interval_wakeup_time);
    if (hibernate_state != HIBERNATE_STATE_DORMANT) {
      /* We weren't sleeping before; we should sleep now. */
      log_notice(LD_ACCT,
                 "Accounting period ended. Commencing hibernation until "
                 "%s GMT", buf);
      hibernate_go_dormant(now);
    } else {
      log_notice(LD_ACCT,
             "Accounting period ended. This period, we will hibernate"
             " until %s GMT",buf);
    }
  }
}

/** Consider our environment and decide if it's time
 * to start/stop hibernating.
 */
void
consider_hibernation(time_t now)
{
  int accounting_enabled = get_options()->AccountingMax != 0;
  char buf[ISO_TIME_LEN+1];

  /* If we're in 'exiting' mode, then we just shut down after the interval
   * elapses. */
  if (hibernate_state == HIBERNATE_STATE_EXITING) {
    tor_assert(shutdown_time);
    if (shutdown_time <= now) {
      log_notice(LD_GENERAL, "Clean shutdown finished. Exiting.");
      tor_cleanup();
      exit(0);
    }
    return; /* if exiting soon, don't worry about bandwidth limits */
  }

  if (hibernate_state == HIBERNATE_STATE_DORMANT) {
    /* We've been hibernating because of bandwidth accounting. */
    tor_assert(hibernate_end_time);
    if (hibernate_end_time > now && accounting_enabled) {
      /* If we're hibernating, don't wake up until it's time, regardless of
       * whether we're in a new interval. */
      return ;
    } else {
      hibernate_end_time_elapsed(now);
    }
  }

  /* Else, we aren't hibernating. See if it's time to start hibernating, or to
   * go dormant. */
  if (hibernate_state == HIBERNATE_STATE_LIVE) {
    if (hibernate_soft_limit_reached()) {
      log_notice(LD_ACCT,
                 "Bandwidth soft limit reached; commencing hibernation.");
      hibernate_begin(HIBERNATE_STATE_LOWBANDWIDTH, now);
    } else if (accounting_enabled && now < interval_wakeup_time) {
      format_local_iso_time(buf,interval_wakeup_time);
      log_notice(LD_ACCT,
                 "Commencing hibernation. We will wake up at %s local time.",
                 buf);
      hibernate_go_dormant(now);
    }
  }

  if (hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH) {
    if (!accounting_enabled) {
      hibernate_end_time_elapsed(now);
    } else if (hibernate_hard_limit_reached()) {
      hibernate_go_dormant(now);
    } else if (hibernate_end_time <= now) {
      /* The hibernation period ended while we were still in lowbandwidth.*/
      hibernate_end_time_elapsed(now);
    }
  }
}

/** Helper function: called when we get a GETINFO request for an
 * accounting-related key on the control connection <b>conn</b>.  If we can
 * answer the request for <b>question</b>, then set *<b>answer</b> to a newly
 * allocated string holding the result.  Otherwise, set *<b>answer</b> to
 * NULL. */
int
getinfo_helper_accounting(control_connection_t *conn,
                          const char *question, char **answer)
{
  (void) conn;
  if (!strcmp(question, "accounting/enabled")) {
    *answer = tor_strdup(accounting_is_enabled(get_options()) ? "1" : "0");
  } else if (!strcmp(question, "accounting/hibernating")) {
    if (hibernate_state == HIBERNATE_STATE_DORMANT)
      *answer = tor_strdup("hard");
    else if (hibernate_state == HIBERNATE_STATE_LOWBANDWIDTH)
      *answer = tor_strdup("soft");
    else
      *answer = tor_strdup("awake");
  } else if (!strcmp(question, "accounting/bytes")) {
    *answer = tor_malloc(32);
    tor_snprintf(*answer, 32, U64_FORMAT" "U64_FORMAT,
                 U64_PRINTF_ARG(n_bytes_read_in_interval),
                 U64_PRINTF_ARG(n_bytes_written_in_interval));
  } else if (!strcmp(question, "accounting/bytes-left")) {
    uint64_t limit = get_options()->AccountingMax;
    uint64_t read_left = 0, write_left = 0;
    if (n_bytes_read_in_interval < limit)
      read_left = limit - n_bytes_read_in_interval;
    if (n_bytes_written_in_interval < limit)
      write_left = limit - n_bytes_written_in_interval;
    *answer = tor_malloc(64);
    tor_snprintf(*answer, 64, U64_FORMAT" "U64_FORMAT,
                 U64_PRINTF_ARG(read_left), U64_PRINTF_ARG(write_left));
  } else if (!strcmp(question, "accounting/interval-start")) {
    *answer = tor_malloc(ISO_TIME_LEN+1);
    format_iso_time(*answer, interval_start_time);
  } else if (!strcmp(question, "accounting/interval-wake")) {
    *answer = tor_malloc(ISO_TIME_LEN+1);
    format_iso_time(*answer, interval_wakeup_time);
  } else if (!strcmp(question, "accounting/interval-end")) {
    *answer = tor_malloc(ISO_TIME_LEN+1);
    format_iso_time(*answer, interval_end_time);
  } else {
    *answer = NULL;
  }
  return 0;
}