Beispiel #1
0
/* This is the first round of the new protocol run starting at
 * <b>valid_after</b>. Do the necessary housekeeping. */
STATIC void
new_protocol_run(time_t valid_after)
{
  sr_commit_t *our_commitment = NULL;

  /* Only compute the srv at the end of the reveal phase. */
  if (sr_state->phase == SR_PHASE_REVEAL) {
    /* We are about to compute a new shared random value that will be set in
     * our state as the current value so rotate values. */
    state_rotate_srv();
    /* Compute the shared randomness value of the day. */
    sr_compute_srv();
  }

  /* Prepare for the new protocol run by reseting the state */
  reset_state_for_new_protocol_run(valid_after);

  /* Do some logging */
  log_info(LD_DIR, "SR: Protocol run #%" PRIu64 " starting!",
           sr_state->n_protocol_runs);

  /* Generate fresh commitments for this protocol run */
  our_commitment = sr_generate_our_commit(valid_after,
                                          get_my_v3_authority_cert());
  if (our_commitment) {
    /* Add our commitment to our state. In case we are unable to create one
     * (highly unlikely), we won't vote for this protocol run since our
     * commitment won't be in our state. */
    sr_state_add_commit(our_commitment);
  }
}
Beispiel #2
0
/* Save <b>commit</b> to our persistent state. Depending on the current
 * phase, different actions are taken. Steals reference of <b>commit</b>.
 * The commit object MUST be valid and verified before adding it to the
 * state. */
STATIC void
save_commit_to_state(sr_commit_t *commit)
{
  sr_phase_t phase = sr_state_get_phase();

  ASSERT_COMMIT_VALID(commit);

  switch (phase) {
  case SR_PHASE_COMMIT:
    /* During commit phase, just save any new authoritative commit */
    sr_state_add_commit(commit);
    break;
  case SR_PHASE_REVEAL:
    save_commit_during_reveal_phase(commit);
    sr_commit_free(commit);
    break;
  default:
    tor_assert(0);
  }
}
Beispiel #3
0
/* Update the current SR state as needed for the upcoming voting round at
 * <b>valid_after</b>. */
void
sr_state_update(time_t valid_after)
{
  sr_phase_t next_phase;

  if (BUG(!sr_state))
    return;

  /* Don't call this function twice in the same voting period. */
  if (valid_after <= sr_state->valid_after) {
    log_info(LD_DIR, "SR: Asked to update state twice. Ignoring.");
    return;
  }

  /* Get phase of upcoming round. */
  next_phase = get_sr_protocol_phase(valid_after);

  /* If we are transitioning to a new protocol phase, prepare the stage. */
  if (is_phase_transition(next_phase)) {
    if (next_phase == SR_PHASE_COMMIT) {
      /* Going into commit phase means we are starting a new protocol run. */
      new_protocol_run(valid_after);
    }
    /* Set the new phase for this round */
    sr_state->phase = next_phase;
  } else if (sr_state->phase == SR_PHASE_COMMIT &&
             digestmap_size(sr_state->commits) == 0) {
    /* We are _NOT_ in a transition phase so if we are in the commit phase
     * and have no commit, generate one. Chances are that we are booting up
     * so let's have a commit in our state for the next voting period. */
    sr_commit_t *our_commit =
      sr_generate_our_commit(valid_after, get_my_v3_authority_cert());
    if (our_commit) {
      /* Add our commitment to our state. In case we are unable to create one
       * (highly unlikely), we won't vote for this protocol run since our
       * commitment won't be in our state. */
      sr_state_add_commit(our_commit);
    }
  }

  sr_state_set_valid_after(valid_after);

  /* Count the current round */
  if (sr_state->phase == SR_PHASE_COMMIT) {
    /* invariant check: we've not entered reveal phase yet */
    if (BUG(sr_state->n_reveal_rounds != 0))
      return;
    sr_state->n_commit_rounds++;
  } else {
    sr_state->n_reveal_rounds++;
  }

  { /* Debugging. */
    char tbuf[ISO_TIME_LEN + 1];
    format_iso_time(tbuf, valid_after);
    log_info(LD_DIR, "SR: State prepared for upcoming voting period (%s). "
             "Upcoming phase is %s (counters: %d commit & %d reveal rounds).",
             tbuf, get_phase_str(sr_state->phase),
             sr_state->n_commit_rounds, sr_state->n_reveal_rounds);
  }
}