config.c

关于tor匿名通信的源代码

    set_conn_limit = 1;

    /* Set up libevent.  (We need to do this before we can register the
     * listeners as listeners.) */
    if (running_tor && !libevent_initialized) {
      init_libevent();
      libevent_initialized = 1;
    }

    /* Launch the listeners.  (We do this before we setuid, so we can bind to
     * ports under 1024.) */
    if (retry_all_listeners(replaced_listeners, new_listeners) < 0) {
      *msg = tor_strdup("Failed to bind one of the listener ports.");
      goto rollback;
    }
  }

  /* Setuid/setgid as appropriate */
  if (options->User || options->Group) {
    /* XXXX021 We should only do this the first time through, not on
     * every setconf. */
    if (switch_id(options->User, options->Group) != 0) {
      /* No need to roll back, since you can't change the value. */
      *msg = tor_strdup("Problem with User or Group value. "
                        "See logs for details.");
      goto done;
    }
  }

  /* Ensure data directory is private; create if possible. */
  if (check_private_dir(options->DataDirectory,
                        running_tor ? CPD_CREATE : CPD_CHECK)<0) {
    char buf[1024];
    int tmp = tor_snprintf(buf, sizeof(buf),
              "Couldn't access/create private data directory \"%s\"",
              options->DataDirectory);
    *msg = tor_strdup(tmp >= 0 ? buf : "internal error");
    goto done;
    /* No need to roll back, since you can't change the value. */
  }

  /* Bail out at this point if we're not going to be a client or server:
   * we don't run Tor itself. */
  if (!running_tor)
    goto commit;

  mark_logs_temp(); /* Close current logs once new logs are open. */
  logs_marked = 1;
  if (options_init_logs(options, 0)<0) { /* Configure the log(s) */
    *msg = tor_strdup("Failed to init Log options. See logs for details.");
    goto rollback;
  }

 commit:
  r = 0;
  if (logs_marked) {
    log_severity_list_t *severity =
      tor_malloc_zero(sizeof(log_severity_list_t));
    close_temp_logs();
    add_callback_log(severity, control_event_logmsg);
    control_adjust_event_log_severity();
    tor_free(severity);
  }
  SMARTLIST_FOREACH(replaced_listeners, connection_t *, conn,
  {
    log_notice(LD_NET, "Closing old %s on %s:%d",
               conn_type_to_string(conn->type), conn->address, conn->port);
    connection_close_immediate(conn);
    connection_mark_for_close(conn);
  });
  goto done;

 rollback:
  r = -1;
  tor_assert(*msg);

  if (logs_marked) {
    rollback_log_changes();
    control_adjust_event_log_severity();
  }

  if (set_conn_limit && old_options)
    set_max_file_descriptors((unsigned)old_options->ConnLimit,
                             &options->_ConnLimit);

  SMARTLIST_FOREACH(new_listeners, connection_t *, conn,
  {
    log_notice(LD_NET, "Closing partially-constructed listener %s on %s:%d",
               conn_type_to_string(conn->type), conn->address, conn->port);
    connection_close_immediate(conn);
    connection_mark_for_close(conn);
  });

 done:
  smartlist_free(new_listeners);
  smartlist_free(replaced_listeners);
  return r;
}

/** Fetch the active option list, and take actions based on it. All of the
 * things we do should survive being done repeatedly.  If present,
 * <b>old_options</b> contains the previous value of the options.
 *
 * Return 0 if all goes well, return -1 if it's time to die.
 *
 * Note: We haven't moved all the "act on new configuration" logic
 * here yet.  Some is still in do_hup() and other places.
 */
static int
options_act(or_options_t *old_options)
{
  config_line_t *cl;
  char *fn;
  size_t len;
  or_options_t *options = get_options();
  int running_tor = options->command == CMD_RUN_TOR;
  char *msg;

  if (consider_adding_dir_authorities(options, old_options) < 0)
    return -1;

  if (options->Bridges) {
    clear_bridge_list();
    for (cl = options->Bridges; cl; cl = cl->next) {
      if (parse_bridge_line(cl->value, 0)<0) {
        log_warn(LD_BUG,
                 "Previously validated Bridge line could not be added!");
        return -1;
      }
    }
  }

  if (running_tor && rend_config_services(options, 0)<0) {
    log_warn(LD_BUG,
       "Previously validated hidden services line could not be added!");
    return -1;
  }

  if (running_tor && directory_caches_v2_dir_info(options)) {
    len = strlen(options->DataDirectory)+32;
    fn = tor_malloc(len);
    tor_snprintf(fn, len, "%s"PATH_SEPARATOR"cached-status",
                 options->DataDirectory);
    if (check_private_dir(fn, CPD_CREATE) != 0) {
      log_warn(LD_CONFIG,
               "Couldn't access/create private data directory \"%s\"", fn);
      tor_free(fn);
      return -1;
    }
    tor_free(fn);
  }

  /* Load state */
  if (! global_state && running_tor) {
    if (or_state_load())
      return -1;
    rep_hist_load_mtbf_data(time(NULL));
  }

  /* Bail out at this point if we're not going to be a client or server:
   * we want to not fork, and to log stuff to stderr. */
  if (!running_tor)
    return 0;

  {
    smartlist_t *sl = smartlist_create();
    char *errmsg = NULL;
    for (cl = options->RedirectExit; cl; cl = cl->next) {
      if (parse_redirect_line(sl, cl, &errmsg)<0) {
        log_warn(LD_CONFIG, "%s", errmsg);
        tor_free(errmsg);
        SMARTLIST_FOREACH(sl, exit_redirect_t *, er, tor_free(er));
        smartlist_free(sl);
        return -1;
      }
    }
    set_exit_redirects(sl);
  }

  /* Finish backgrounding the process */
  if (running_tor && options->RunAsDaemon) {
    /* We may be calling this for the n'th time (on SIGHUP), but it's safe. */
    finish_daemon(options->DataDirectory);
  }

  /* Write our pid to the pid file. If we do not have write permissions we
   * will log a warning */
  if (running_tor && options->PidFile)
    write_pidfile(options->PidFile);

  /* Register addressmap directives */
  config_register_addressmaps(options);
  parse_virtual_addr_network(options->VirtualAddrNetwork, 0, &msg);

  /* Update address policies. */
  if (policies_parse_from_options(options) < 0) {
    /* This should be impossible, but let's be sure. */
    log_warn(LD_BUG,"Error parsing already-validated policy options.");
    return -1;
  }

  if (init_cookie_authentication(options->CookieAuthentication) < 0) {
    log_warn(LD_CONFIG,"Error creating cookie authentication file.");
    return -1;
  }

  /* reload keys as needed for rendezvous services. */
  if (rend_service_load_keys()<0) {
    log_warn(LD_GENERAL,"Error loading rendezvous service keys");
    return -1;
  }

  /* Set up accounting */
  if (accounting_parse_options(options, 0)<0) {
    log_warn(LD_CONFIG,"Error in accounting options");
    return -1;
  }
  if (accounting_is_enabled(options))
    configure_accounting(time(NULL));

  /* Check for transitions that need action. */
  if (old_options) {
    if (options->UseEntryGuards && !old_options->UseEntryGuards) {
      log_info(LD_CIRC,
               "Switching to entry guards; abandoning previous circuits");
      circuit_mark_all_unused_circs();
      circuit_expire_all_dirty_circs();
    }

    if (options_transition_affects_workers(old_options, options)) {
      log_info(LD_GENERAL,
               "Worker-related options changed. Rotating workers.");
      if (server_mode(options) && !server_mode(old_options)) {
        if (init_keys() < 0) {
          log_warn(LD_BUG,"Error initializing keys; exiting");
          return -1;
        }
        ip_address_changed(0);
        if (has_completed_circuit || !any_predicted_circuits(time(NULL)))
          inform_testing_reachability();
      }
      cpuworkers_rotate();
      if (dns_reset())
        return -1;
    } else {
      if (dns_reset())
        return -1;
    }

    if (options->V3AuthoritativeDir && !old_options->V3AuthoritativeDir)
      init_keys();
  }

  /* Maybe load geoip file */
  if (options->GeoIPFile &&
      ((!old_options || !opt_streq(old_options->GeoIPFile, options->GeoIPFile))
       || !geoip_is_loaded())) {
    geoip_load_file(options->GeoIPFile);
  }
  /* Check if we need to parse and add the EntryNodes config option. */
  if (options->EntryNodes &&
      (!old_options ||
       !opt_streq(old_options->EntryNodes, options->EntryNodes)))
    entry_nodes_should_be_added();

  /* Since our options changed, we might need to regenerate and upload our
   * server descriptor.
   */
  if (!old_options ||
      options_transition_affects_descriptor(old_options, options))
    mark_my_descriptor_dirty();

  /* We may need to reschedule some directory stuff if our status changed. */
  if (old_options) {
    if (authdir_mode_v3(options) && !authdir_mode_v3(old_options))
      dirvote_recalculate_timing(options, time(NULL));
    if (!bool_eq(directory_fetches_dir_info_early(options),
                 directory_fetches_dir_info_early(old_options)) ||
        !bool_eq(directory_fetches_dir_info_later(options),
                 directory_fetches_dir_info_later(old_options))) {
      /* Make sure update_router_have_min_dir_info gets called. */
      router_dir_info_changed();
      /* We might need to download a new consensus status later or sooner than
       * we had expected. */
      update_consensus_networkstatus_fetch_time(time(NULL));
    }
  }

  return 0;
}

/*
 * Functions to parse config options
 */

/** If <b>option</b> is an official abbreviation for a longer option,
 * return the longer option.  Otherwise return <b>option</b>.
 * If <b>command_line</b> is set, apply all abbreviations.  Otherwise, only
 * apply abbreviations that work for the config file and the command line.
 * If <b>warn_obsolete</b> is set, warn about deprecated names. */
static const char *
expand_abbrev(config_format_t *fmt, const char *option, int command_line,
              int warn_obsolete)
{
  int i;
  if (! fmt->abbrevs)
    return option;
  for (i=0; fmt->abbrevs[i].abbreviated; ++i) {
    /* Abbreviations are casei. */
    if (!strcasecmp(option,fmt->abbrevs[i].abbreviated) &&
        (command_line || !fmt->abbrevs[i].commandline_only)) {
      if (warn_obsolete && fmt->abbrevs[i].warn) {
        log_warn(LD_CONFIG,
                 "The configuration option '%s' is deprecated; "
                 "use '%s' instead.",
                 fmt->abbrevs[i].abbreviated,
                 fmt->abbrevs[i].full);
      }
      return fmt->abbrevs[i].full;
    }
  }
  return option;
}

/** Helper: Read a list of configuration options from the command line.
 * If successful, put them in *<b>result</b> and return 0, and return
 * -1 and leave *<b>result</b> alone. */
static int
config_get_commandlines(int argc, char **argv, config_line_t **result)
{
  config_line_t *front = NULL;
  config_line_t **new = &front;
  char *s;
  int i = 1;