rephist.c

关于tor匿名通信的源代码

      i -= NUM_TOTALS;
    tor_assert(i < NUM_TOTALS);
    /* Round the bandwidth used down to the nearest 1k. */
    total = b->totals[i] & ~0x3ff;
    if (total > cutoff)
      total = cutoff;

    if (n==(b->num_maxes_set-1))
      tor_snprintf(cp, len-(cp-buf), U64_FORMAT, U64_PRINTF_ARG(total));
    else
      tor_snprintf(cp, len-(cp-buf), U64_FORMAT",", U64_PRINTF_ARG(total));
    cp += strlen(cp);
  }
  return cp-buf;
}

/** Allocate and return lines for representing this server's bandwidth
 * history in its descriptor.
 */
char *
rep_hist_get_bandwidth_lines(int for_extrainfo)
{
  char *buf, *cp;
  char t[ISO_TIME_LEN+1];
  int r;
  bw_array_t *b;
  size_t len;

  /* opt (read|write)-history yyyy-mm-dd HH:MM:SS (n s) n,n,n,n,n... */
  len = (60+20*NUM_TOTALS)*2;
  buf = tor_malloc_zero(len);
  cp = buf;
  for (r=0;r<2;++r) {
    b = r?read_array:write_array;
    tor_assert(b);
    format_iso_time(t, b->next_period-NUM_SECS_BW_SUM_INTERVAL);
    tor_snprintf(cp, len-(cp-buf), "%s%s %s (%d s) ",
                 for_extrainfo ? "" : "opt ",
                 r ? "read-history" : "write-history", t,
                 NUM_SECS_BW_SUM_INTERVAL);
    cp += strlen(cp);
    cp += rep_hist_fill_bandwidth_history(cp, len-(cp-buf), b);
    strlcat(cp, "\n", len-(cp-buf));
    ++cp;
  }
  return buf;
}

/** Update <b>state</b> with the newest bandwidth history. */
void
rep_hist_update_state(or_state_t *state)
{
  int len, r;
  char *buf, *cp;
  smartlist_t **s_values;
  time_t *s_begins;
  int *s_interval;
  bw_array_t *b;

  len = 20*NUM_TOTALS+1;
  buf = tor_malloc_zero(len);

  for (r=0;r<2;++r) {
    b = r?read_array:write_array;
    s_begins  = r?&state->BWHistoryReadEnds    :&state->BWHistoryWriteEnds;
    s_interval= r?&state->BWHistoryReadInterval:&state->BWHistoryWriteInterval;
    s_values  = r?&state->BWHistoryReadValues  :&state->BWHistoryWriteValues;

    if (*s_values) {
      SMARTLIST_FOREACH(*s_values, char *, val, tor_free(val));
      smartlist_free(*s_values);
    }
    if (! server_mode(get_options())) {
      /* Clients don't need to store bandwidth history persistently;
       * force these values to the defaults. */
      /* FFFF we should pull the default out of config.c's state table,
       * so we don't have two defaults. */
      if (*s_begins != 0 || *s_interval != 900) {
        time_t now = time(NULL);
        time_t save_at = get_options()->AvoidDiskWrites ? now+3600 : now+600;
        or_state_mark_dirty(state, save_at);
      }
      *s_begins = 0;
      *s_interval = 900;
      *s_values = smartlist_create();
      continue;
    }
    *s_begins = b->next_period;
    *s_interval = NUM_SECS_BW_SUM_INTERVAL;
    cp = buf;
    cp += rep_hist_fill_bandwidth_history(cp, len, b);
    tor_snprintf(cp, len-(cp-buf), cp == buf ? U64_FORMAT : ","U64_FORMAT,
                 U64_PRINTF_ARG(b->total_in_period));
    *s_values = smartlist_create();
    if (server_mode(get_options()))
      smartlist_split_string(*s_values, buf, ",", SPLIT_SKIP_SPACE, 0);
  }
  tor_free(buf);
  if (server_mode(get_options())) {
    or_state_mark_dirty(get_or_state(), time(NULL)+(2*3600));
  }
}

/** Set bandwidth history from our saved state. */
int
rep_hist_load_state(or_state_t *state, char **err)
{
  time_t s_begins, start;
  time_t now = time(NULL);
  uint64_t v;
  int r,i,ok;
  int all_ok = 1;
  int s_interval;
  smartlist_t *s_values;
  bw_array_t *b;

  /* Assert they already have been malloced */
  tor_assert(read_array && write_array);

  for (r=0;r<2;++r) {
    b = r?read_array:write_array;
    s_begins = r?state->BWHistoryReadEnds:state->BWHistoryWriteEnds;
    s_interval =  r?state->BWHistoryReadInterval:state->BWHistoryWriteInterval;
    s_values =  r?state->BWHistoryReadValues:state->BWHistoryWriteValues;
    if (s_values && s_begins >= now - NUM_SECS_BW_SUM_INTERVAL*NUM_TOTALS) {
      start = s_begins - s_interval*(smartlist_len(s_values));
      if (start > now)
        continue;
      b->cur_obs_time = start;
      b->next_period = start + NUM_SECS_BW_SUM_INTERVAL;
      SMARTLIST_FOREACH(s_values, char *, cp, {
        v = tor_parse_uint64(cp, 10, 0, UINT64_MAX, &ok, NULL);
        if (!ok) {
          all_ok=0;
          log_notice(LD_GENERAL, "Could not parse '%s' into a number.'", cp);
        }
        if (start < now) {
          add_obs(b, start, v);
          start += NUM_SECS_BW_SUM_INTERVAL;
        }
      });
    }

    /* Clean up maxima and observed */
    /* Do we really want to zero this for the purpose of max capacity? */
    for (i=0; i<NUM_SECS_ROLLING_MEASURE; ++i) {
      b->obs[i] = 0;
    }
    b->total_obs = 0;
    for (i=0; i<NUM_TOTALS; ++i) {
      b->maxima[i] = 0;
    }
    b->max_total = 0;
  }

  if (!all_ok) {
    *err = tor_strdup("Parsing of bandwidth history values failed");
    /* and create fresh arrays */
    tor_free(read_array);
    tor_free(write_array);
    read_array = bw_array_new();
    write_array = bw_array_new();
    return -1;
  }
  return 0;
}

/*********************************************************************/

/** A list of port numbers that have been used recently. */
static smartlist_t *predicted_ports_list=NULL;
/** The corresponding most recently used time for each port. */
static smartlist_t *predicted_ports_times=NULL;

/** We just got an application request for a connection with
 * port <b>port</b>. Remember it for the future, so we can keep
 * some circuits open that will exit to this port.
 */
static void
add_predicted_port(time_t now, uint16_t port)
{
  /* XXXX we could just use uintptr_t here, I think. */
  uint16_t *tmp_port = tor_malloc(sizeof(uint16_t));
  time_t *tmp_time = tor_malloc(sizeof(time_t));
  *tmp_port = port;
  *tmp_time = now;
  rephist_total_alloc += sizeof(uint16_t) + sizeof(time_t);
  smartlist_add(predicted_ports_list, tmp_port);
  smartlist_add(predicted_ports_times, tmp_time);
}

/** Initialize whatever memory and structs are needed for predicting
 * which ports will be used. Also seed it with port 80, so we'll build
 * circuits on start-up.
 */
static void
predicted_ports_init(void)
{
  predicted_ports_list = smartlist_create();
  predicted_ports_times = smartlist_create();
  add_predicted_port(time(NULL), 80); /* add one to kickstart us */
}

/** Free whatever memory is needed for predicting which ports will
 * be used.
 */
static void
predicted_ports_free(void)
{
  rephist_total_alloc -= smartlist_len(predicted_ports_list)*sizeof(uint16_t);
  SMARTLIST_FOREACH(predicted_ports_list, char *, cp, tor_free(cp));
  smartlist_free(predicted_ports_list);
  rephist_total_alloc -= smartlist_len(predicted_ports_times)*sizeof(time_t);
  SMARTLIST_FOREACH(predicted_ports_times, char *, cp, tor_free(cp));
  smartlist_free(predicted_ports_times);
}

/** Remember that <b>port</b> has been asked for as of time <b>now</b>.
 * This is used for predicting what sorts of streams we'll make in the
 * future and making exit circuits to anticipate that.
 */
void
rep_hist_note_used_port(time_t now, uint16_t port)
{
  int i;
  uint16_t *tmp_port;
  time_t *tmp_time;

  tor_assert(predicted_ports_list);
  tor_assert(predicted_ports_times);

  if (!port) /* record nothing */
    return;

  for (i = 0; i < smartlist_len(predicted_ports_list); ++i) {
    tmp_port = smartlist_get(predicted_ports_list, i);
    tmp_time = smartlist_get(predicted_ports_times, i);
    if (*tmp_port == port) {
      *tmp_time = now;
      return;
    }
  }
  /* it's not there yet; we need to add it */
  add_predicted_port(now, port);
}

/** For this long after we've seen a request for a given port, assume that
 * we'll want to make connections to the same port in the future.  */
#define PREDICTED_CIRCS_RELEVANCE_TIME (60*60)

/** Return a pointer to the list of port numbers that
 * are likely to be asked for in the near future.
 *
 * The caller promises not to mess with it.
 */
smartlist_t *
rep_hist_get_predicted_ports(time_t now)
{
  int i;
  uint16_t *tmp_port;
  time_t *tmp_time;

  tor_assert(predicted_ports_list);
  tor_assert(predicted_ports_times);

  /* clean out obsolete entries */
  for (i = 0; i < smartlist_len(predicted_ports_list); ++i) {
    tmp_time = smartlist_get(predicted_ports_times, i);
    if (*tmp_time + PREDICTED_CIRCS_RELEVANCE_TIME < now) {
      tmp_port = smartlist_get(predicted_ports_list, i);
      log_debug(LD_CIRC, "Expiring predicted port %d", *tmp_port);
      smartlist_del(predicted_ports_list, i);
      smartlist_del(predicted_ports_times, i);
      rephist_total_alloc -= sizeof(uint16_t)+sizeof(time_t);
      tor_free(tmp_port);
      tor_free(tmp_time);
      i--;
    }
  }
  return predicted_ports_list;
}

/** The user asked us to do a resolve. Rather than keeping track of
 * timings and such of resolves, we fake it for now by treating
 * it the same way as a connection to port 80. This way we will continue
 * to have circuits lying around if the user only uses Tor for resolves.
 */
void
rep_hist_note_used_resolve(time_t now)
{
  rep_hist_note_used_port(now, 80);
}

/** The last time at which we needed an internal circ. */
static time_t predicted_internal_time = 0;
/** The last time we needed an internal circ with good uptime. */
static time_t predicted_internal_uptime_time = 0;
/** The last time we needed an internal circ with good capacity. */
static time_t predicted_internal_capacity_time = 0;

/** Remember that we used an internal circ at time <b>now</b>. */
void
rep_hist_note_used_internal(time_t now, int need_uptime, int need_capacity)
{
  predicted_internal_time = now;
  if (need_uptime)
    predicted_internal_uptime_time = now;
  if (need_capacity)
    predicted_internal_capacity_time = now;
}

/** Return 1 if we've used an internal circ recently; else return 0. */
int
rep_hist_get_predicted_internal(time_t now, int *need_uptime,
                                int *need_capacity)
{
  if (!predicted_internal_time) { /* initialize it */
    predicted_internal_time = now;
    predicted_internal_uptime_time = now;
    predicted_internal_capacity_time = now;
  }
  if (predicted_internal_time + PREDICTED_CIRCS_RELEVANCE_TIME < now)
    return 0; /* too long ago */
  if (predicted_internal_uptime_time + PREDICTED_CIRCS_RELEVANCE_TIME >= now)
    *need_uptime = 1;
  if (predicted_internal_capacity_time + PREDICTED_CIRCS_RELEVANCE_TIME >= now)
    *need_capacity = 1;
  return 1;
}

/** Any ports used lately? These are pre-seeded if we just started
 * up or if we're running a hidden service. */
int
any_predicted_circuits(time_t now)
{
  return smartlist_len(predicted_ports_list) ||
         predicted_internal_time + PREDICTED_CIRCS_RELEVANCE_TIME >= now;
}

/** Return 1 if we have no need for circuits currently, else return 0. */
int
rep_hist_circbuilding_dormant(time_t now)
{
  if (any_predicted_circuits(now))
    return 0;

  /* see if we'll still need to build testing circuits */
  if (server_mode(get_options()) &&
      (!check_whether_orport_reachable() || !circuit_enough_testing_circs()))
    return 0;
  if (!check_whether_dirport_reachable())
    return 0;

  return 1;
}

static uint32_t n_signed_dir_objs = 0;
static uint32_t n_signed_routerdescs = 0;
static uint32_t n_verified_dir_objs = 0;
static uint32_t n_verified_routerdescs = 0;
static uint32_t n_onionskins_encrypted = 0;
static uint32_t n_onionskins_decrypted = 0;
static uint32_t n_tls_client_handshakes = 0;
static uint32_t n_tls_server_handshakes = 0;
static uint32_t n_rend_client_ops = 0;
static uint32_t n_rend_mid_ops = 0;
static uint32_t n_rend_server_ops = 0;

/** Increment the count of the number of times we've done <b>operation</b>. */
void
note_crypto_pk_op(pk_op_t operation)
{
  switch (operation)
    {
    case SIGN_DIR:
      n_signed_dir_objs++;
      break;
    case SIGN_RTR:
      n_signed_routerdescs++;
      break;
    case VERIFY_DIR:
      n_verified_dir_objs++;
      break;
    case VERIFY_RTR:
      n_verified_routerdescs++;
      break;
    case ENC_ONIONSKIN:
      n_onionskins_encrypted++;
      break;
    case DEC_ONIONSKIN:
      n_onionskins_decrypted++;
      break;
    case TLS_HANDSHAKE_C:
      n_tls_client_handshakes++;
      break;
    case TLS_HANDSHAKE_S:
      n_tls_server_handshakes++;
      break;
    case REND_CLIENT:
      n_rend_client_ops++;
      break;