commit e044b4f8ce8ba009ed11b662f46d254b52a2791c Author: Nick Mathewson nickm@torproject.org Date: Thu Dec 8 12:19:40 2016 -0500

Support restrictive ENTRYNODES configurations correctly.

Since we already had a separate function for getting the universe of possible guards, all we had to do was tweak it to handle very the GS_TYPE_RESTRICTED case. --- src/or/entrynodes.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c index ac5398f..ad4f99c 100644 --- a/src/or/entrynodes.c +++ b/src/or/entrynodes.c @@ -965,7 +965,8 @@ get_max_sample_size(guard_selection_t *gs, * that were already sampled. */ static smartlist_t * -get_eligible_guards(guard_selection_t *gs, +get_eligible_guards(const or_options_t *options, + guard_selection_t *gs, int *n_guards_out) { /* Construct eligible_guards as GUARDS - SAMPLED_GUARDS */ @@ -995,6 +996,14 @@ get_eligible_guards(guard_selection_t *gs, SMARTLIST_FOREACH_BEGIN(nodes, const node_t *, node) { if (! node_is_possible_guard(node)) continue; + if (gs->type == GS_TYPE_RESTRICTED) { + /* In restricted mode, we apply the filter BEFORE sampling, so + * that we are sampling from the nodes that we might actually + * select. If we sampled first, we might wind up with a sample + * that didn't include any EntryNodes at all. */ + if (! node_passes_guard_filter(options, node)) + continue; + } ++n_guards; if (digestset_contains(sampled_guard_ids, node->identity)) continue; @@ -1046,11 +1055,12 @@ STATIC entry_guard_t * entry_guards_expand_sample(guard_selection_t *gs) { tor_assert(gs); + const or_options_t *options = get_options(); int n_sampled = smartlist_len(gs->sampled_entry_guards); entry_guard_t *added_guard = NULL; int n_usable_filtered_guards = num_reachable_filtered_guards(gs, NULL); int n_guards = 0; - smartlist_t *eligible_guards = get_eligible_guards(gs, &n_guards); + smartlist_t *eligible_guards = get_eligible_guards(options, gs, &n_guards);

const int max_sample = get_max_sample_size(gs, n_guards); const int min_filtered_sample = get_min_filtered_sample_size();