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Remove intro points adaptative algorithm

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Partially fixes #4862

Signed-off-by: David Goulet <dgoulet@ev0ke.net>
This commit is contained in:
David Goulet 2015-05-11 14:46:15 -04:00
parent cc3a791d55
commit 8dcbdf58a7
1 changed files with 3 additions and 123 deletions
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126
src/or/rendservice.c
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@ -87,8 +87,6 @@ struct rend_service_port_config_s {
/** Try to maintain this many intro points per service by default. */
#define NUM_INTRO_POINTS_DEFAULT 3
/** Maintain no more than this many intro points per hidden service. */
#define NUM_INTRO_POINTS_MAX 10
/** If we can't build our intro circuits, don't retry for this long. */
#define INTRO_CIRC_RETRY_PERIOD (60*5)
@ -177,17 +175,6 @@ num_rend_services(void)
return smartlist_len(rend_service_list);
}
/** Return a string identifying <b>service</b>, suitable for use in a
* log message. The result does not need to be freed, but may be
* overwritten by the next call to this function. */
static const char *
rend_service_describe_for_log(rend_service_t *service)
{
/* XXX024 Use this function throughout rendservice.c. */
/* XXX024 Return a more useful description? */
return safe_str_client(service->service_id);
}
/** Helper: free storage held by a single service authorized client entry. */
static void
rend_authorized_client_free(rend_authorized_client_t *client)
@ -1417,107 +1404,6 @@ rend_check_authorization(rend_service_t *service,
return 1;
}
/** Called when <b>intro</b> will soon be removed from
* <b>service</b>'s list of intro points. */
static void
rend_service_note_removing_intro_point(rend_service_t *service,
rend_intro_point_t *intro)
{
time_t now = time(NULL);
/* Don't process an intro point twice here. */
if (intro->rend_service_note_removing_intro_point_called) {
return;
} else {
intro->rend_service_note_removing_intro_point_called = 1;
}
/* Update service->n_intro_points_wanted based on how long intro
* lasted and how many introductions it handled. */
if (intro->time_published == -1) {
/* This intro point was never used. Don't change
* n_intro_points_wanted. */
} else {
/* We want to increase the number of introduction points service
* operates if intro was heavily used, or decrease the number of
* intro points if intro was lightly used.
*
* We consider an intro point's target 'usage' to be
* maximum of INTRODUCE2 cells divided by
* INTRO_POINT_LIFETIME_MIN_SECONDS seconds. To calculate intro's
* fraction of target usage, we divide the amount of INTRODUCE2 cells
* that it has handled by the fraction of _LIFETIME_MIN_SECONDS for
* which it existed.
*
* Then we multiply that fraction of desired usage by a fudge
* factor of 1.5, to decide how many new introduction points
* should ideally replace intro (which is now closed or soon to be
* closed). In theory, assuming that introduction load is
* distributed equally across all intro points and ignoring the
* fact that different intro points are established and closed at
* different times, that number of intro points should bring all
* of our intro points exactly to our target usage.
*
* Then we clamp that number to a number of intro points we might
* be willing to replace this intro point with and turn it into an
* integer. then we clamp it again to the number of new intro
* points we could establish now, then we adjust
* service->n_intro_points_wanted and let rend_services_introduce
* create the new intro points we want (if any).
*/
const double intro_point_usage =
intro_point_accepted_intro_count(intro) /
(double)(now - intro->time_published);
const double intro_point_target_usage =
intro->max_introductions /
(double)INTRO_POINT_LIFETIME_MIN_SECONDS;
const double fractional_n_intro_points_wanted_to_replace_this_one =
(1.5 * (intro_point_usage / intro_point_target_usage));
unsigned int n_intro_points_wanted_to_replace_this_one;
unsigned int n_intro_points_wanted_now;
unsigned int n_intro_points_really_wanted_now;
int n_intro_points_really_replacing_this_one;
if (fractional_n_intro_points_wanted_to_replace_this_one >
NUM_INTRO_POINTS_MAX) {
n_intro_points_wanted_to_replace_this_one = NUM_INTRO_POINTS_MAX;
} else if (fractional_n_intro_points_wanted_to_replace_this_one < 0) {
n_intro_points_wanted_to_replace_this_one = 0;
} else {
n_intro_points_wanted_to_replace_this_one = (unsigned)
fractional_n_intro_points_wanted_to_replace_this_one;
}
n_intro_points_wanted_now =
service->n_intro_points_wanted +
n_intro_points_wanted_to_replace_this_one - 1;
if (n_intro_points_wanted_now < NUM_INTRO_POINTS_DEFAULT) {
/* XXXX This should be NUM_INTRO_POINTS_MIN instead. Perhaps
* another use of NUM_INTRO_POINTS_DEFAULT should be, too. */
n_intro_points_really_wanted_now = NUM_INTRO_POINTS_DEFAULT;
} else if (n_intro_points_wanted_now > NUM_INTRO_POINTS_MAX) {
n_intro_points_really_wanted_now = NUM_INTRO_POINTS_MAX;
} else {
n_intro_points_really_wanted_now = n_intro_points_wanted_now;
}
n_intro_points_really_replacing_this_one =
n_intro_points_really_wanted_now - service->n_intro_points_wanted + 1;
log_info(LD_REND, "Replacing closing intro point for service %s "
"with %d new intro points (wanted %g replacements); "
"service will now try to have %u intro points",
rend_service_describe_for_log(service),
n_intro_points_really_replacing_this_one,
fractional_n_intro_points_wanted_to_replace_this_one,
n_intro_points_really_wanted_now);
service->n_intro_points_wanted = n_intro_points_really_wanted_now;
}
}
/******
* Handle cells
******/
@ -3506,16 +3392,15 @@ rend_services_introduce(void)
node = node_get_by_id(intro->extend_info->identity_digest);
if (!node || !intro_circ) {
int removing_this_intro_point_changes_the_intro_point_set = 1;
intro_point_set_changed = 1;
log_info(LD_REND, "Giving up on %s as intro point for %s"
" (circuit disappeared).",
safe_str_client(extend_info_describe(intro->extend_info)),
safe_str_client(service->service_id));
rend_service_note_removing_intro_point(service, intro);
if (intro->time_expiring != -1) {
log_info(LD_REND, "We were already expiring the intro point; "
"no need to mark the HS descriptor as dirty over this.");
removing_this_intro_point_changes_the_intro_point_set = 0;
intro_point_set_changed = 0;
} else if (intro->listed_in_last_desc) {
log_info(LD_REND, "The intro point we are giving up on was "
"included in the last published descriptor. "
@ -3525,17 +3410,12 @@ rend_services_introduce(void)
rend_intro_point_free(intro);
intro = NULL; /* SMARTLIST_DEL_CURRENT takes a name, not a value. */
SMARTLIST_DEL_CURRENT(service->intro_nodes, intro);
if (removing_this_intro_point_changes_the_intro_point_set)
intro_point_set_changed = 1;
}
if (intro != NULL && intro_point_should_expire_now(intro, now)) {
log_info(LD_REND, "Expiring %s as intro point for %s.",
safe_str_client(extend_info_describe(intro->extend_info)),
safe_str_client(service->service_id));
rend_service_note_removing_intro_point(service, intro);
/* The polite (and generally Right) way to expire an intro
* point is to establish a new one to replace it, publish a
* new descriptor that doesn't list any expiring intro points,
@ -3561,7 +3441,7 @@ rend_services_introduce(void)
} SMARTLIST_FOREACH_END(intro);
if (!intro_point_set_changed &&
(n_intro_points_unexpired >= service->n_intro_points_wanted)) {
(n_intro_points_unexpired == service->n_intro_points_wanted)) {
continue;
}