Make authorities not set Running unless all advertised OR ports are reachable.

Resolves #6621.

src/or/dirserv.c

@@ -980,6 +980,7 @@ dirserv_set_router_is_running(routerinfo_t *router, time_t now)
     unreachable.
    */
   int answer;
+  const or_options_t *options = get_options();
   node_t *node = node_get_mutable_by_id(router->cache_info.identity_digest);
   tor_assert(node);
 
@@ -992,13 +993,23 @@ dirserv_set_router_is_running(routerinfo_t *router, time_t now)
     /* A hibernating router is down unless we (somehow) had contact with it
      * since it declared itself to be hibernating. */
     answer = 0;
-  } else if (get_options()->AssumeReachable) {
+  } else if (options->AssumeReachable) {
     /* If AssumeReachable, everybody is up unless they say they are down! */
     answer = 1;
   } else {
-    /* Otherwise, a router counts as up if we found it reachable in the last
-       REACHABLE_TIMEOUT seconds. */
-    answer = (now < node->last_reachable + REACHABLE_TIMEOUT);
+    /* Otherwise, a router counts as up if we found all announced OR
+       ports reachable in the last REACHABLE_TIMEOUT seconds.
+
+       XXX prop186 For now there's always one IPv4 and at most one
+       IPv6 OR port.
+
+       If we're not on IPv6, don't consider reachability of potential
+       IPv6 OR port since that'd kill all dual stack relays until a
+       majority of the dir auths have IPv6 connectivity. */
+    answer = (now < node->last_reachable + REACHABLE_TIMEOUT &&
+              (options->AuthDirHasIPv6Connectivity == 0 ||
+               tor_addr_is_null(&router->ipv6_addr) ||
+               now < node->last_reachable6 + REACHABLE_TIMEOUT));
   }
 
   if (!answer && running_long_enough_to_decide_unreachable()) {
@@ -1008,6 +1019,8 @@ dirserv_set_router_is_running(routerinfo_t *router, time_t now)
        REACHABILITY_TEST_CYCLE_PERIOD seconds, then the router has probably
        been down since at least that time after we last successfully reached
        it.
+
+       XXX ipv6
      */
     time_t when = now;
     if (node->last_reachable &&