Skip dirserver restrictions in small networks.

This commit is contained in:
George Kadianakis 2017-11-13 22:26:22 +02:00 committed by Nick Mathewson
parent f61e3090fb
commit c400ffc2e8

View File

@ -1472,12 +1472,45 @@ guard_create_exit_restriction(const uint8_t *exit_id)
return rst;
}
/** Allocate and return an outdated md guard restriction. */
/** If we have less than these many configured bridges, don't set dirserver
* restrictions because we might blacklist all of them. */
#define TOO_FEW_BRIDGES_FOR_RESTRICTION 10
/** Return true if we should set md dirserver restrictions. We might not want
* to set those if our network is too restricted, since we don't want to
* blacklist all our nodes. */
static int
should_set_md_dirserver_restriction(void)
{
const guard_selection_t *gs = get_guard_selection_info();
/* Don't set a restriction if we are on a restricted guard selection */
if (gs->type == GS_TYPE_RESTRICTED) {
return 0;
}
/* Don't set restriction if we are using bridges and have too few of those */
if (gs->type == GS_TYPE_BRIDGE && gs->sampled_entry_guards) {
int num_sampled_guards = smartlist_len(gs->sampled_entry_guards);
if (num_sampled_guards < TOO_FEW_BRIDGES_FOR_RESTRICTION) {
return 0;
}
}
return 1;
}
/** Allocate and return an outdated md guard restriction. Return NULL if no
* such restriction is needed. */
STATIC entry_guard_restriction_t *
guard_create_dirserver_md_restriction(void)
{
entry_guard_restriction_t *rst = NULL;
if (!should_set_md_dirserver_restriction()) {
return NULL;
}
rst = tor_malloc_zero(sizeof(entry_guard_restriction_t));
rst->type = RST_OUTDATED_MD_DIRSERVER;
@ -1504,13 +1537,6 @@ guard_obeys_exit_restriction(const entry_guard_t *guard,
static int
guard_obeys_md_dirserver_restriction(const entry_guard_t *guard)
{
/* Don't enforce dirserver restrictions for bridges since we might not have
* many of those. Be willing to try them over and over again for now. */
/* XXX: Improvement might be possible here */
if (guard->bridge_addr) {
return 1;
}
/* If this guard is an outdated dirserver, don't use it. */
if (microdesc_relay_is_outdated_dirserver(guard->identity)) {
log_info(LD_GENERAL, "Skipping %s dirserver: outdated",