Remove v0 hidden service statistics code.

The HSAuthorityRecordStats option was used to track statistics of overall
hidden service usage on the version 0 hidden service authorities. With the
version 2 hidden service directories being deployed and version 0
descriptors being phased out, these statistics are not as useful anymore.

Goodbye, you fine piece of software; my first major code contribution to
Tor.

1 files changed, 0 insertions, 554 deletions

diff --git a/src/or/rephist.c b/src/or/rephist.c
index 36318c7558..af7a2157f0 100644
--- a/src/or/rephist.c
+++ b/src/or/rephist.c
@@ -14,7 +14,6 @@
 
 static void bw_arrays_init(void);
 static void predicted_ports_init(void);
-static void hs_usage_init(void);
 
 /** Total number of bytes currently allocated in fields used by rephist.c. */
 uint64_t rephist_total_alloc=0;
@@ -185,7 +184,6 @@ rep_hist_init(void)
   history_map = digestmap_new();
   bw_arrays_init();
   predicted_ports_init();
-  hs_usage_init();
 }
 
 /** Helper: note that we are no longer connected to the router with history
@@ -2057,558 +2055,6 @@ rep_hist_free_all(void)
   predicted_ports_free();
 }
 
-/****************** hidden service usage statistics ******************/
-
-/** How large are the intervals for which we track and report hidden service
- * use? */
-#define NUM_SECS_HS_USAGE_SUM_INTERVAL (15*60)
-/** How far in the past do we remember and publish hidden service use? */
-#define NUM_SECS_HS_USAGE_SUM_IS_VALID (24*60*60)
-/** How many hidden service usage intervals do we remember? (derived) */
-#define NUM_TOTALS_HS_USAGE (NUM_SECS_HS_USAGE_SUM_IS_VALID/ \
-                             NUM_SECS_HS_USAGE_SUM_INTERVAL)
-
-/** List element containing a service id and the count. */
-typedef struct hs_usage_list_elem_t {
-   /** Service id of this elem. */
-  char service_id[REND_SERVICE_ID_LEN_BASE32+1];
-  /** Number of occurrences for the given service id. */
-  uint32_t count;
-  /* Pointer to next list elem */
-  struct hs_usage_list_elem_t *next;
-} hs_usage_list_elem_t;
-
-/** Ordered list that stores service ids and the number of observations. It is
- * ordered by the number of occurrences in descending order. Its purpose is to
- * calculate the frequency distribution when the period is over. */
-typedef struct hs_usage_list_t {
-  /* Pointer to the first element in the list. */
-  hs_usage_list_elem_t *start;
-  /* Number of total occurrences for all list elements. */
-  uint32_t total_count;
-  /* Number of service ids, i.e. number of list elements. */
-  uint32_t total_service_ids;
-} hs_usage_list_t;
-
-/** Tracks service-related observations in the current period and their
- * history. */
-typedef struct hs_usage_service_related_observation_t {
-  /** Ordered list that stores service ids and the number of observations in
-   * the current period. It is ordered by the number of occurrences in
-   * descending order. Its purpose is to calculate the frequency distribution
-   * when the period is over. */
-  hs_usage_list_t *list;
-  /** Circular arrays that store the history of observations. totals stores all
-   * observations, twenty (ten, five) the number of observations related to a
-   * service id being accounted for the top 20 (10, 5) percent of all
-   * observations. */
-  uint32_t totals[NUM_TOTALS_HS_USAGE];
-  uint32_t five[NUM_TOTALS_HS_USAGE];
-  uint32_t ten[NUM_TOTALS_HS_USAGE];
-  uint32_t twenty[NUM_TOTALS_HS_USAGE];
-} hs_usage_service_related_observation_t;
-
-/** Tracks the history of general period-related observations, i.e. those that
- * cannot be related to a specific service id. */
-typedef struct hs_usage_general_period_related_observations_t {
-  /** Circular array that stores the history of observations. */
-  uint32_t totals[NUM_TOTALS_HS_USAGE];
-} hs_usage_general_period_related_observations_t;
-
-/** Keeps information about the current observation period and its relation to
- * the histories of observations. */
-typedef struct hs_usage_current_observation_period_t {
-  /** Where do we write the next history entry? */
-  int next_idx;
-  /** How many values in history have been set ever? (upper bound!) */
-  int num_set;
-  /** When did this period begin? */
-  time_t start_of_current_period;
-  /** When does the next period begin? */
-  time_t start_of_next_period;
-} hs_usage_current_observation_period_t;
-
-/** Usage statistics for the current observation period. */
-static hs_usage_current_observation_period_t *current_period = NULL;
-
-/** Total number of descriptor publish requests in the current observation
- * period. */
-static hs_usage_service_related_observation_t *publish_total = NULL;
-
-/** Number of descriptor publish requests for services that have not been
- * seen before in the current observation period. */
-static hs_usage_service_related_observation_t *publish_novel = NULL;
-
-/** Total number of descriptor fetch requests in the current observation
- * period. */
-static hs_usage_service_related_observation_t *fetch_total = NULL;
-
-/** Number of successful descriptor fetch requests in the current
- * observation period. */
-static hs_usage_service_related_observation_t *fetch_successful = NULL;
-
-/** Number of descriptors stored in the current observation period. */
-static hs_usage_general_period_related_observations_t *descs = NULL;
-
-/** Creates an empty ordered list element. */
-static hs_usage_list_elem_t *
-hs_usage_list_elem_new(void)
-{
-  hs_usage_list_elem_t *e;
-  e = tor_malloc_zero(sizeof(hs_usage_list_elem_t));
-  rephist_total_alloc += sizeof(hs_usage_list_elem_t);
-  e->count = 1;
-  e->next = NULL;
-  return e;
-}
-
-/** Creates an empty ordered list. */
-static hs_usage_list_t *
-hs_usage_list_new(void)
-{
-  hs_usage_list_t *l;
-  l = tor_malloc_zero(sizeof(hs_usage_list_t));
-  rephist_total_alloc += sizeof(hs_usage_list_t);
-  l->start = NULL;
-  l->total_count = 0;
-  l->total_service_ids = 0;
-  return l;
-}
-
-/** Creates an empty structure for storing service-related observations. */
-static hs_usage_service_related_observation_t *
-hs_usage_service_related_observation_new(void)
-{
-  hs_usage_service_related_observation_t *h;
-  h = tor_malloc_zero(sizeof(hs_usage_service_related_observation_t));
-  rephist_total_alloc += sizeof(hs_usage_service_related_observation_t);
-  h->list = hs_usage_list_new();
-  return h;
-}
-
-/** Creates an empty structure for storing general period-related
- * observations. */
-static hs_usage_general_period_related_observations_t *
-hs_usage_general_period_related_observations_new(void)
-{
-  hs_usage_general_period_related_observations_t *p;
-  p = tor_malloc_zero(sizeof(hs_usage_general_period_related_observations_t));
-  rephist_total_alloc+= sizeof(hs_usage_general_period_related_observations_t);
-  return p;
-}
-
-/** Creates an empty structure for storing period-specific information. */
-static hs_usage_current_observation_period_t *
-hs_usage_current_observation_period_new(void)
-{
-  hs_usage_current_observation_period_t *c;
-  time_t now;
-  c = tor_malloc_zero(sizeof(hs_usage_current_observation_period_t));
-  rephist_total_alloc += sizeof(hs_usage_current_observation_period_t);
-  now = time(NULL);
-  c->start_of_current_period = now;
-  c->start_of_next_period = now + NUM_SECS_HS_USAGE_SUM_INTERVAL;
-  return c;
-}
-
-/** Initializes the structures for collecting hidden service usage data. */
-static void
-hs_usage_init(void)
-{
-  current_period = hs_usage_current_observation_period_new();
-  publish_total = hs_usage_service_related_observation_new();
-  publish_novel = hs_usage_service_related_observation_new();
-  fetch_total = hs_usage_service_related_observation_new();
-  fetch_successful = hs_usage_service_related_observation_new();
-  descs = hs_usage_general_period_related_observations_new();
-}
-
-/** Clears the given ordered list by resetting its attributes and releasing
- * the memory allocated by its elements. */
-static void
-hs_usage_list_clear(hs_usage_list_t *lst)
-{
-  /* walk through elements and free memory */
-  hs_usage_list_elem_t *current = lst->start;
-  hs_usage_list_elem_t *tmp;
-  while (current != NULL) {
-    tmp = current->next;
-    rephist_total_alloc -= sizeof(hs_usage_list_elem_t);
-    tor_free(current);
-    current = tmp;
-  }
-  /* reset attributes */
-  lst->start = NULL;
-  lst->total_count = 0;
-  lst->total_service_ids = 0;
-  return;
-}
-
-/** Frees the memory used by the given list. */
-static void
-hs_usage_list_free(hs_usage_list_t *lst)
-{
-  if (!lst)
-    return;
-  hs_usage_list_clear(lst);
-  rephist_total_alloc -= sizeof(hs_usage_list_t);
-  tor_free(lst);
-}
-
-/** Frees the memory used by the given service-related observations. */
-static void
-hs_usage_service_related_observation_free(
-                                    hs_usage_service_related_observation_t *s)
-{
-  if (!s)
-    return;
-  hs_usage_list_free(s->list);
-  rephist_total_alloc -= sizeof(hs_usage_service_related_observation_t);
-  tor_free(s);
-}
-
-/** Frees the memory used by the given period-specific observations. */
-static void
-hs_usage_general_period_related_observations_free(
-                             hs_usage_general_period_related_observations_t *s)
-{
-  if (!s)
-    return;
-  rephist_total_alloc-=sizeof(hs_usage_general_period_related_observations_t);
-  tor_free(s);
-}
-
-/** Frees the memory used by period-specific information. */
-static void
-hs_usage_current_observation_period_free(
-                                    hs_usage_current_observation_period_t *s)
-{
-  if (!s)
-    return;
-  rephist_total_alloc -= sizeof(hs_usage_current_observation_period_t);
-  tor_free(s);
-}
-
-/** Frees all memory that was used for collecting hidden service usage data. */
-void
-hs_usage_free_all(void)
-{
-  hs_usage_general_period_related_observations_free(descs);
-  descs = NULL;
-  hs_usage_service_related_observation_free(fetch_successful);
-  hs_usage_service_related_observation_free(fetch_total);
-  hs_usage_service_related_observation_free(publish_novel);
-  hs_usage_service_related_observation_free(publish_total);
-  fetch_successful = fetch_total = publish_novel = publish_total = NULL;
-  hs_usage_current_observation_period_free(current_period);
-  current_period = NULL;
-}
-
-/** Inserts a new occurrence for the given service id to the given ordered
- * list. */
-static void
-hs_usage_insert_value(hs_usage_list_t *lst, const char *service_id)
-{
-  /* search if there is already an elem with same service_id in list */
-  hs_usage_list_elem_t *current = lst->start;
-  hs_usage_list_elem_t *previous = NULL;
-  while (current != NULL && strcasecmp(current->service_id,service_id)) {
-    previous = current;
-    current = current->next;
-  }
-  /* found an element with same service_id? */
-  if (current == NULL) {
-    /* not found! append to end (which could also be the end of a zero-length
-     * list), don't need to sort (1 is smallest value). */
-    /* create elem */
-    hs_usage_list_elem_t *e = hs_usage_list_elem_new();
-    /* update list attributes (one new elem, one new occurrence) */
-    lst->total_count++;
-    lst->total_service_ids++;
-    /* copy service id to elem */
-    strlcpy(e->service_id,service_id,sizeof(e->service_id));
-    /* let either l->start or previously last elem point to new elem */
-    if (lst->start == NULL) {
-      /* this is the first elem */
-      lst->start = e;
-    } else {
-      /* there were elems in the list before */
-      previous->next = e;
-    }
-  } else {
-    /* found! add occurrence to elem and consider resorting */
-    /* update list attributes (no new elem, but one new occurrence) */
-    lst->total_count++;
-    /* add occurrence to elem */
-    current->count++;
-    /* is it another than the first list elem? and has previous elem fewer
-     * count than current? then we need to resort */
-    if (previous != NULL && previous->count < current->count) {
-      /* yes! we need to resort */
-      /* remove current elem first */
-      previous->next = current->next;
-      /* can we prepend elem to all other elements? */
-      if (lst->start->count <= current->count) {
-        /* yes! prepend elem */
-        current->next = lst->start;
-        lst->start = current;
-      } else {
-        /* no! walk through list a second time and insert at correct place */
-        hs_usage_list_elem_t *insert_current = lst->start->next;
-        hs_usage_list_elem_t *insert_previous = lst->start;
-        while (insert_current != NULL &&
-               insert_current->count > current->count) {
-          insert_previous = insert_current;
-          insert_current = insert_current->next;
-        }
-        /* insert here */
-        current->next = insert_current;
-        insert_previous->next = current;
-      }
-    }
-  }
-}
-
-/** Writes the current service-related observations to the history array and
- * clears the observations of the current period. */
-static void
-hs_usage_write_service_related_observations_to_history(
-                                    hs_usage_current_observation_period_t *p,
-                                    hs_usage_service_related_observation_t *h)
-{
-  /* walk through the first 20 % of list elements and calculate frequency
-   * distributions */
-  /* maximum indices for the three frequencies */
-  int five_percent_idx = h->list->total_service_ids/20;
-  int ten_percent_idx = h->list->total_service_ids/10;
-  int twenty_percent_idx = h->list->total_service_ids/5;
-  /* temp values */
-  uint32_t five_percent = 0;
-  uint32_t ten_percent = 0;
-  uint32_t twenty_percent = 0;
-  /* walk through list */
-  hs_usage_list_elem_t *current = h->list->start;
-  int i=0;
-  while (current != NULL && i <= twenty_percent_idx) {
-    twenty_percent += current->count;
-    if (i <= ten_percent_idx)
-      ten_percent += current->count;
-    if (i <= five_percent_idx)
-      five_percent += current->count;
-    current = current->next;
-    i++;
-  }
-  /* copy frequencies */
-  h->twenty[p->next_idx] = twenty_percent;
-  h->ten[p->next_idx] = ten_percent;
-  h->five[p->next_idx] = five_percent;
-  /* copy total number of observations */
-  h->totals[p->next_idx] = h->list->total_count;
-  /* free memory of old list */
-  hs_usage_list_clear(h->list);
-}
-
-/** Advances to next observation period. */
-static void
-hs_usage_advance_current_observation_period(void)
-{
-  /* aggregate observations to history, including frequency distribution
-   * arrays */
-  hs_usage_write_service_related_observations_to_history(
-                                    current_period, publish_total);
-  hs_usage_write_service_related_observations_to_history(
-                                    current_period, publish_novel);
-  hs_usage_write_service_related_observations_to_history(
-                                    current_period, fetch_total);
-  hs_usage_write_service_related_observations_to_history(
-                                    current_period, fetch_successful);
-  /* write current number of descriptors to descs history */
-  descs->totals[current_period->next_idx] = rend_cache_size();
-  /* advance to next period */
-  current_period->next_idx++;
-  if (current_period->next_idx == NUM_TOTALS_HS_USAGE)
-    current_period->next_idx = 0;
-  if (current_period->num_set < NUM_TOTALS_HS_USAGE)
-    ++current_period->num_set;
-  current_period->start_of_current_period=current_period->start_of_next_period;
-  current_period->start_of_next_period += NUM_SECS_HS_USAGE_SUM_INTERVAL;
-}
-
-/** Checks if the current period is up to date, and if not, advances it. */
-static void
-hs_usage_check_if_current_period_is_up_to_date(time_t now)
-{
-  while (now > current_period->start_of_next_period) {
-    hs_usage_advance_current_observation_period();
-  }
-}
-
-/** Adds a service-related observation, maybe after advancing to next
- * observation period. */
-static void
-hs_usage_add_service_related_observation(
-                                    hs_usage_service_related_observation_t *h,
-                                    time_t now,
-                                    const char *service_id)
-{
-  if (now < current_period->start_of_current_period) {
-    /* don't record old data */
-    return;
-  }
-  /* check if we are up-to-date */
-  hs_usage_check_if_current_period_is_up_to_date(now);
-  /* add observation */
-  hs_usage_insert_value(h->list, service_id);
-}
-
-/** Adds the observation of storing a rendezvous service descriptor to our
- * cache in our role as HS authoritative directory. */
-void
-hs_usage_note_publish_total(const char *service_id, time_t now)
-{
-  hs_usage_add_service_related_observation(publish_total, now, service_id);
-}
-
-/** Adds the observation of storing a novel rendezvous service descriptor to
- * our cache in our role as HS authoritative directory. */
-void
-hs_usage_note_publish_novel(const char *service_id, time_t now)
-{
-  hs_usage_add_service_related_observation(publish_novel, now, service_id);
-}
-
-/** Adds the observation of being requested for a rendezvous service descriptor
- * in our role as HS authoritative directory. */
-void
-hs_usage_note_fetch_total(const char *service_id, time_t now)
-{
-  hs_usage_add_service_related_observation(fetch_total, now, service_id);
-}
-
-/** Adds the observation of being requested for a rendezvous service descriptor
- * in our role as HS authoritative directory and being able to answer that
- * request successfully. */
-void
-hs_usage_note_fetch_successful(const char *service_id, time_t now)
-{
-  hs_usage_add_service_related_observation(fetch_successful, now, service_id);
-}
-
-/** Writes the given circular array to a string. */
-static size_t
-hs_usage_format_history(char *buf, size_t len, uint32_t *data)
-{
-  char *cp = buf; /* pointer where we are in the buffer */
-  int i, n;
-  if (current_period->num_set <= current_period->next_idx) {
-    i = 0; /* not been through circular array */
-  } else {
-    i = current_period->next_idx;
-  }
-  for (n = 0; n < current_period->num_set; ++n,++i) {
-    if (i >= NUM_TOTALS_HS_USAGE)
-      i -= NUM_TOTALS_HS_USAGE;
-    tor_assert(i < NUM_TOTALS_HS_USAGE);
-    if (n == (current_period->num_set-1))
-      tor_snprintf(cp, len-(cp-buf), "%d", data[i]);
-    else
-      tor_snprintf(cp, len-(cp-buf), "%d,", data[i]);
-    cp += strlen(cp);
-  }
-  return cp-buf;
-}
-
-/** Writes the complete usage history as hidden service authoritative directory
- * to a string. */
-static char *
-hs_usage_format_statistics(void)
-{
-  char *buf, *cp, *s = NULL;
-  char t[ISO_TIME_LEN+1];
-  int r;
-  uint32_t *data = NULL;
-  size_t len;
-  len = (70+20*NUM_TOTALS_HS_USAGE)*11;
-  buf = tor_malloc_zero(len);
-  cp = buf;
-  for (r = 0; r < 11; ++r) {
-    switch (r) {
-    case 0:
-      s = (char*) "publish-total-history";
-      data = publish_total->totals;
-      break;
-    case 1:
-      s = (char*) "publish-novel-history";
-      data = publish_novel->totals;
-      break;
-    case 2:
-      s = (char*) "publish-top-5-percent-history";
-      data = publish_total->five;
-      break;
-    case 3:
-      s = (char*) "publish-top-10-percent-history";
-      data = publish_total->ten;
-      break;
-    case 4:
-      s = (char*) "publish-top-20-percent-history";
-      data = publish_total->twenty;
-      break;
-    case 5:
-      s = (char*) "fetch-total-history";
-      data = fetch_total->totals;
-      break;
-    case 6:
-      s = (char*) "fetch-successful-history";
-      data = fetch_successful->totals;
-      break;
-    case 7:
-      s = (char*) "fetch-top-5-percent-history";
-      data = fetch_total->five;
-      break;
-    case 8:
-      s = (char*) "fetch-top-10-percent-history";
-      data = fetch_total->ten;
-      break;
-    case 9:
-      s = (char*) "fetch-top-20-percent-history";
-      data = fetch_total->twenty;
-      break;
-    case 10:
-      s = (char*) "desc-total-history";
-      data = descs->totals;
-      break;
-    }
-    format_iso_time(t, current_period->start_of_current_period);
-    tor_snprintf(cp, len-(cp-buf), "%s %s (%d s) ", s, t,
-                 NUM_SECS_HS_USAGE_SUM_INTERVAL);
-    cp += strlen(cp);
-    cp += hs_usage_format_history(cp, len-(cp-buf), data);
-    strlcat(cp, "\n", len-(cp-buf));
-    ++cp;
-  }
-  return buf;
-}
-
-/** Write current statistics about hidden service usage to file. */
-void
-hs_usage_write_statistics_to_file(time_t now)
-{
-  char *buf;
-  size_t len;
-  char *fname;
-  or_options_t *options = get_options();
-  /* check if we are up-to-date */
-  hs_usage_check_if_current_period_is_up_to_date(now);
-  buf = hs_usage_format_statistics();
-  len = strlen(options->DataDirectory) + 16;
-  fname = tor_malloc(len);
-  tor_snprintf(fname, len, "%s"PATH_SEPARATOR"hsusage",
-               options->DataDirectory);
-  write_str_to_file(fname,buf,0);
-  tor_free(buf);
-  tor_free(fname);
-}
-
 /*** cell statistics ***/
 
 /** Start of the current buffer stats interval. */