Commit 6a0763cd authored by David Goulet's avatar David Goulet 🐼
Browse files

guard: Ignore marked for close circuit when changing state to open 



When we consider all circuits in "waiting for guard" state to be promoted to
an "open" state, we were considering all circuits, even the one marked for
close.

This ultiamtely triggers a "circuit_has_opened()" called on the circuit that
is marked for close which then leads to possible undesirable behaviors within
a subsystem.

For instance, the HS subsystem would be unable to find the authentication key
of the introduction point circuit leading to a BUG() warning and a duplicate
mark for close on the circuit.

This commit also adds a unit test to make sure we never select marked for
close circuits when upgrading its guard state from waiting for guard to open.

Fixes #30871

Signed-off-by: David Goulet's avatarDavid Goulet <dgoulet@torproject.org>
parent ea14fb13

changes/ticket30871

0 → 100644
+6 −0
Original line number Diff line number Diff line 
  o Major bugfixes (circuit build, guard):

    - When considering upgrading circuits from "waiting for guard" to "open",

      always ignore the ones that are mark for close. Else, we can end up in

      the situation where a subsystem is notified of that circuit opening but

      still marked for close leading to undesirable behavior. Fixes bug 30871;

      bugfix on 0.3.0.1-alpha.

src/feature/client/entrynodes.c

+4 −0
Original line number Diff line number Diff line
@@ -2611,6 +2611,10 @@ entry_guards_upgrade_waiting_circuits(guard_selection_t *gs, 
    entry_guard_t *guard = entry_guard_handle_get(state->guard);

    if (!guard || guard->in_selection != gs)

      continue;

    if (TO_CIRCUIT(circ)->marked_for_close) {

      /* Don't consider any marked for close circuits. */

      continue;

    }



    smartlist_add(all_circuits, circ);

  } SMARTLIST_FOREACH_END(circ);

src/test/test_circuitbuild.c

+47 −0
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ 
/* See LICENSE for licensing information */



#define CIRCUITBUILD_PRIVATE

#define CIRCUITLIST_PRIVATE

#define ENTRYNODES_PRIVATE



#include "core/or/or.h"

#include "test/test.h"
@@ -13,7 +15,11 @@ 
#include "core/or/circuitbuild.h"

#include "core/or/circuitlist.h"



#include "core/or/cpath_build_state_st.h"

#include "core/or/extend_info_st.h"

#include "core/or/origin_circuit_st.h"



#include "feature/client/entrynodes.h"



/* Dummy nodes smartlist for testing */

static smartlist_t dummy_nodes;
@@ -126,10 +132,51 @@ test_new_route_len_unhandled_exit(void *arg) 
  UNMOCK(count_acceptable_nodes);

}



static void

test_upgrade_from_guard_wait(void *arg)

{

  circuit_t *circ = NULL;

  origin_circuit_t *orig_circ = NULL;

  entry_guard_t *guard = NULL;

  smartlist_t *list = NULL;



  (void) arg;



  circ = dummy_origin_circuit_new(0);

  orig_circ = TO_ORIGIN_CIRCUIT(circ);

  tt_assert(orig_circ);



  orig_circ->build_state = tor_malloc_zero(sizeof(cpath_build_state_t));



  circuit_set_state(circ, CIRCUIT_STATE_GUARD_WAIT);



  /* Put it in guard wait state. */

  guard = tor_malloc_zero(sizeof(*guard));

  guard->in_selection = get_guard_selection_info();



  orig_circ->guard_state =

    circuit_guard_state_new(guard, GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD,

                            NULL);



  /* Mark the circuit for close. */

  circuit_mark_for_close(circ, END_CIRC_REASON_TORPROTOCOL);

  tt_int_op(circ->marked_for_close, OP_NE, 0);



  /* We shouldn't pick the mark for close circuit. */

  list = circuit_find_circuits_to_upgrade_from_guard_wait();

  tt_assert(!list);



 done:

  circuit_free(circ);

  entry_guard_free_(guard);

}



struct testcase_t circuitbuild_tests[] = {

  { "noexit", test_new_route_len_noexit, 0, NULL, NULL },

  { "safe_exit", test_new_route_len_safe_exit, 0, NULL, NULL },

  { "unsafe_exit", test_new_route_len_unsafe_exit, 0, NULL, NULL },

  { "unhandled_exit", test_new_route_len_unhandled_exit, 0, NULL, NULL },

  { "upgrade_from_guard_wait", test_upgrade_from_guard_wait, TT_FORK,

    NULL, NULL },

  END_OF_TESTCASES

};