commit 96b69942a54e69e9f4d8aeb07bf9a5fb98892900 Author: Nick Mathewson nickm@torproject.org Date: Thu Nov 16 08:49:24 2017 -0500

Make should_set_md_dirserver_restriction() look at num filtered guards

This seems closer to what the code intended. --- src/or/entrynodes.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c index 1cc24d8d6..dc02557b5 100644 --- a/src/or/entrynodes.c +++ b/src/or/entrynodes.c @@ -1472,9 +1472,10 @@ guard_create_exit_restriction(const uint8_t *exit_id) return rst; }

-/** 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 +/** If we have fewer than this many possible guards, don't set + * MD-availability-based restrictions: we might blacklist all of + * them. */ +#define MIN_GUARDS_FOR_MD_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 @@ -1484,20 +1485,17 @@ 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; + /* Compute the number of filtered guards */ + int n_filtered_guards = 0; + SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) { + if (guard->is_filtered_guard) { + ++n_filtered_guards; } - } + } SMARTLIST_FOREACH_END(guard);

- return 1; + /* Do we have enough filtered guards that we feel okay about blacklisting + * some for MD restriction? */ + return (n_filtered_guards >= MIN_GUARDS_FOR_MD_RESTRICTION); }

/** Allocate and return an outdated md guard restriction. Return NULL if no @@ -1508,6 +1506,8 @@ guard_create_dirserver_md_restriction(void) entry_guard_restriction_t *rst = NULL;

if (!should_set_md_dirserver_restriction()) { + log_debug(LD_GUARD, "Not setting md restriction: too few " + "filtered guards."); return NULL; }