Return NULL from extend_info_from_node if the node has no allowed address

Modify callers to correctly handle these new NULL returns:
* fix assert in onion_extend_cpath
* warn and discard circuit in circuit_get_open_circ_or_launch
* warn, discard circuit, and tell controller in handle_control_extendcircuit

1 files changed, 6 insertions, 1 deletions

diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index e742a5614f..4831f2be76 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -2006,8 +2006,13 @@ circuit_get_open_circ_or_launch(entry_connection_t *conn,
         if (r && node_has_descriptor(r)) {
           /* We might want to connect to an IPv6 bridge for loading
              descriptors so we use the preferred address rather than
-             the primary.  */
+             the primary. */
           extend_info = extend_info_from_node(r, conn->want_onehop ? 1 : 0);
+          if (!extend_info) {
+            log_warn(LD_CIRC,"Could not make a one-hop connection to %s. "
+                     "Discarding this circuit.", conn->chosen_exit_name);
+            return -1;
+          }
         } else {
           log_debug(LD_DIR, "considering %d, %s",
                     want_onehop, conn->chosen_exit_name);