Commit dd085d42 authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

Do not count controller-selected paths towards path bias. 

As a side effect, this fixes a "Bug" warning.

Closes #40515.  Bugfix on 0.2.4.10-alpha.
parent 882fd1f0

changes/bug40515

0 → 100644
+6 −0
Original line number Diff line number Diff line 
  o Minor bugfixes (controller, path bias):

    - When a circuit's path is specified, in full or in part, from the

      controller API, do not count that circuit towards our path-bias

      calculations. (Doing so was incorrect, since we cannot tell whether

      the controller is selecting relays randomly.)  Resolves a "Bug"

      warning. Fixes bug 40515; bugfix on 0.2.4.10-alpha.

src/core/or/origin_circuit_st.h

+6 −0
Original line number Diff line number Diff line
@@ -182,6 +182,12 @@ struct origin_circuit_t { 
   */

  unsigned first_hop_from_controller : 1;



  /**

   * If true, this circuit's path has been chosen, in full or in part,

   * by the controller API, and it's okay to ignore checks that we'd

   * usually do on the path as whole. */

  unsigned int any_hop_from_controller : 1;



  /**

   * Tristate variable to guard against pathbias miscounting

   * due to circuit purpose transitions changing the decision

src/feature/client/circpathbias.c

+11 −0
Original line number Diff line number Diff line
@@ -363,6 +363,17 @@ pathbias_should_count(origin_circuit_t *circ) 
    return 0;

  }



  /* Ignore circuits where the controller helped choose the path.  When

   * this happens, we can't be sure whether the path was chosen randomly

   * or not. */

  if (circ->any_hop_from_controller) {

    /* (In this case, we _don't_ check to see if shouldcount is changing,

     * since it's possible that an already-created circuit later gets extended

     * by the controller. */

    circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_IGNORED;

    return 0;

  }



  /* Completely ignore one hop circuits */

  if (circ->build_state->onehop_tunnel ||

      circ->build_state->desired_path_len == 1) {

src/feature/control/control_cmd.c

+2 −0
Original line number Diff line number Diff line
@@ -822,6 +822,8 @@ handle_control_extendcircuit(control_connection_t *conn, 
    circ->first_hop_from_controller = 1;

  }



  circ->any_hop_from_controller = 1;



  /* now circ refers to something that is ready to be extended */

  first_node = zero_circ;

  SMARTLIST_FOREACH(nodes, const node_t *, node,