Prop210: Check fallback directories and authorities work as expected

}

/** Check if we can use fallback directory mirrors for a consensus download.

 * Only clients that have a list of additional fallbacks can use fallbacks. */

 * If we have fallbacks and don't want to fetch from the authorities,

 * we can use them. */

int

networkstatus_consensus_can_use_extra_fallbacks(const or_options_t *options)

{

  /* If we are a client, and we have additional mirrors, we can use them.

   * The list length comparisons are a quick way to check if we have any

  /* The list length comparisons are a quick way to check if we have any

   * non-authority fallback directories. If we ever have any authorities that

   * aren't fallback directories, we will need to change this code. */

  tor_assert(smartlist_len(router_get_fallback_dir_servers())

             >= smartlist_len(router_get_trusted_dir_servers()));

  /* If we don't fetch from the authorities, and we have additional mirrors,

   * we can use them. */

  return (!directory_fetches_from_authorities(options)

          && (smartlist_len(router_get_fallback_dir_servers())

              > smartlist_len(router_get_trusted_dir_servers())));