Commit f8baa40c authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

GETINFO bw-event-cache to get information on recent BW events 

Closes 14128; useful to regain functionality lost because of 13988.
parent 1abd526c

changes/ticket14128

0 → 100644
+5 −0
Original line number Diff line number Diff line 
  o Minor features (controller):

    - New "GETINFO bw-event-cache" to get information about recent bandwidth

      events. Closes ticket 14128. Useful for controllers to get recent

      bandwidth history after the fix for 13988.

src/or/control.c

+50 −0
Original line number Diff line number Diff line
@@ -1438,6 +1438,8 @@ getinfo_helper_misc(control_connection_t *conn, const char *question, 
  (void) conn;

  if (!strcmp(question, "version")) {

    *answer = tor_strdup(get_version());

  } else if (!strcmp(question, "bw-event-cache")) {

    *answer = get_bw_samples();

  } else if (!strcmp(question, "config-file")) {

    *answer = tor_strdup(get_torrc_fname(0));

  } else if (!strcmp(question, "config-defaults-file")) {
@@ -2113,6 +2115,7 @@ typedef struct getinfo_item_t { 
 * to answer them. */

static const getinfo_item_t getinfo_items[] = {

  ITEM("version", misc, "The current version of Tor."),

  ITEM("bw-event-cache", misc, "Cached BW events for a short interval."),

  ITEM("config-file", misc, "Current location of the \"torrc\" file."),

  ITEM("config-defaults-file", misc, "Current location of the defaults file."),

  ITEM("config-text", misc,
@@ -4155,11 +4158,29 @@ control_event_tb_empty(const char *bucket, uint32_t read_empty_time, 
  return 0;

}



/* about 5 minutes worth. */

#define N_BW_EVENTS_TO_CACHE 300

/* Index into cached_bw_events to next write. */

static int next_measurement_idx = 0;

/* number of entries set in n_measurements */

static int n_measurements = 0;

static struct cached_bw_event_s {

  uint32_t n_read;

  uint32_t n_written;

} cached_bw_events[N_BW_EVENTS_TO_CACHE];



/** A second or more has elapsed: tell any interested control

 * connections how much bandwidth we used. */

int

control_event_bandwidth_used(uint32_t n_read, uint32_t n_written)

{

  cached_bw_events[next_measurement_idx].n_read = n_read;

  cached_bw_events[next_measurement_idx].n_written = n_written;

  if (++next_measurement_idx == N_BW_EVENTS_TO_CACHE)

    next_measurement_idx = 0;

  if (n_measurements < N_BW_EVENTS_TO_CACHE)

    ++n_measurements;



  if (EVENT_IS_INTERESTING(EVENT_BANDWIDTH_USED)) {

    send_control_event(EVENT_BANDWIDTH_USED, ALL_FORMATS,

                       "650 BW %lu %lu\r\n",
@@ -4170,6 +4191,35 @@ control_event_bandwidth_used(uint32_t n_read, uint32_t n_written) 
  return 0;

}



STATIC char *

get_bw_samples(void)

{

  int i;

  int idx = (next_measurement_idx + N_BW_EVENTS_TO_CACHE - n_measurements)

    % N_BW_EVENTS_TO_CACHE;

  tor_assert(0 <= idx && idx < N_BW_EVENTS_TO_CACHE);



  smartlist_t *elements = smartlist_new();



  for (i = 0; i < n_measurements; ++i) {

    tor_assert(0 <= idx && idx < N_BW_EVENTS_TO_CACHE);

    const struct cached_bw_event_s *bwe = &cached_bw_events[idx];



    smartlist_add_asprintf(elements, "%u,%u",

                           (unsigned)bwe->n_read,

                           (unsigned)bwe->n_written);



    idx = (idx + 1) % N_BW_EVENTS_TO_CACHE;

  }



  char *result = smartlist_join_strings(elements, " ", 0, NULL);



  SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp));

  smartlist_free(elements);



  return result;

}



/** Called when we are sending a log message to the controllers: suspend

 * sending further log messages to the controllers until we're done.  Used by

 * CONN_LOG_PROTECT. */

src/or/control.h

+1 −0
Original line number Diff line number Diff line
@@ -203,6 +203,7 @@ void append_cell_stats_by_command(smartlist_t *event_parts, 
                                  const uint64_t *number_to_include);

void format_cell_stats(char **event_string, circuit_t *circ,

                       cell_stats_t *cell_stats);

STATIC char *get_bw_samples(void);

#endif



#endif