Don't build circuits till primary guards have descriptors

In addition to not wanting to build circuits until we can see most
of the paths in the network, and in addition to not wanting to build
circuits until we have a consensus ... we shouldn't build circuits
till all of our (in-use) primary guards have descriptors that we can
use for them.

This is another bug 21242 fix.

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c
index 1cf1ff2c8e0ef91563321d21e8bb5179828e0a6e..6249e847a9b687647567558b69790d648317ac50 100644 (file)
--- a/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@ -3335,6 +3335,43 @@ guards_retry_optimistic(const or_options_t *options)
   return 1;
 }
 
+/**
+ * Return true iff we know enough directory information to construct
+ * circuits through all of the primary guards we'd currently use.
+ */
+int
+guard_selection_have_enough_dir_info_to_build_circuits(guard_selection_t *gs)
+{
+  if (!gs->primary_guards_up_to_date)
+    entry_guards_update_primary(gs);
+
+  const int num_primary = get_n_primary_guards_to_use(GUARD_USAGE_TRAFFIC);
+  int n_missing_descriptors = 0;
+  int n_considered = 0;
+
+  SMARTLIST_FOREACH_BEGIN(gs->primary_entry_guards, entry_guard_t *, guard) {
+    entry_guard_consider_retry(guard);
+    if (guard->is_reachable == GUARD_REACHABLE_NO)
+      continue;
+    n_considered++;
+    if (!guard_has_descriptor(guard))
+      n_missing_descriptors++;
+    if (n_considered >= num_primary)
+      break;
+  } SMARTLIST_FOREACH_END(guard);
+
+  return n_missing_descriptors == 0;
+}
+
+/** As guard_selection_have_enough_dir_info_to_build_circuits, but uses
+ * the default guard selection. */
+int
+entry_guards_have_enough_dir_info_to_build_circuits(void)
+{
+  return guard_selection_have_enough_dir_info_to_build_circuits(
+                                        get_guard_selection_info());
+}
+
 /** Free one guard selection context */
 STATIC void
 guard_selection_free(guard_selection_t *gs)

diff --git a/src/or/entrynodes.h b/src/or/entrynodes.h
index 0c29292c17744b6a2adf7394feb5208346d982c2..f02901f5d704cd15794a4453f0221970df33eda7 100644 (file)
--- a/src/or/entrynodes.h
+++ b/src/or/entrynodes.h
@@ -482,6 +482,7 @@ STATIC entry_guard_t *get_sampled_guard_with_id(guard_selection_t *gs,
                                                 const uint8_t *rsa_id);
 
 MOCK_DECL(STATIC time_t, randomize_time, (time_t now, time_t max_backdate));
+
 STATIC entry_guard_t *entry_guard_add_to_sample(guard_selection_t *gs,
                                                 const node_t *node);
 STATIC entry_guard_t *entry_guards_expand_sample(guard_selection_t *gs);
@@ -566,6 +567,10 @@ int getinfo_helper_entry_guards(control_connection_t *conn,
 int entries_known_but_down(const or_options_t *options);
 void entries_retry_all(const or_options_t *options);
 
+int guard_selection_have_enough_dir_info_to_build_circuits(
+                                                    guard_selection_t *gs);
+int entry_guards_have_enough_dir_info_to_build_circuits(void);
+
 void entry_guards_free_all(void);
 
 double pathbias_get_close_success_count(entry_guard_t *guard);

diff --git a/src/or/nodelist.c b/src/or/nodelist.c
index 804af297baf83ab994f5249a53a60452210a973d..96e95baf5a6c7130f05c08cc6db1138d6c272274 100644 (file)
--- a/src/or/nodelist.c
+++ b/src/or/nodelist.c
@@ -43,6 +43,7 @@
 #include "config.h"
 #include "control.h"
 #include "dirserv.h"
+#include "entrynodes.h"
 #include "geoip.h"
 #include "main.h"
 #include "microdesc.h"
@@ -1991,6 +1992,13 @@ update_router_have_minimum_dir_info(void)
 
   using_md = consensus->flavor == FLAV_MICRODESC;
 
+  if (! entry_guards_have_enough_dir_info_to_build_circuits()) {
+    strlcpy(dir_info_status, "We're missing descriptors for some of our "
+            "primary entry guards", sizeof(dir_info_status));
+    res = 0;
+    goto done;
+  }
+
   /* Check fraction of available paths */
   {
     char *status = NULL;