Commit 7b6b2d5f authored by Robert Ransom's avatar Robert Ransom Committed by Nick Mathewson
Browse files

Refactor stream attachment in circuit_has_opened 

Put the 'try attaching streams, clear isolation state if possible, retry
attaching streams' loop in its own separate function, where it belongs.
parent 7a76994d

src/or/circuituse.c

+35 −18
Original line number Diff line number Diff line
@@ -1004,7 +1004,6 @@ circuit_testing_failed(origin_circuit_t *circ, int at_last_hop) 
void

circuit_has_opened(origin_circuit_t *circ)

{

  int can_try_clearing_isolation = 0, tried_clearing_isolation = 0;

  control_event_circuit_status(circ, CIRC_EVENT_BUILT, 0);



  /* Remember that this circuit has finished building. Now if we start
@@ -1012,20 +1011,18 @@ circuit_has_opened(origin_circuit_t *circ) 
   * to consider its build time. */

  circ->has_opened = 1;



 again:



  switch (TO_CIRCUIT(circ)->purpose) {

    case CIRCUIT_PURPOSE_C_ESTABLISH_REND:

      rend_client_rendcirc_has_opened(circ);

      /* XXXX We'd like to set something like "can_try_clearing_isolation"

       * here, so that we can change the isolation of this circuit (and maybe

       * its purpose too) if it turns out that we no longer have any streams

       * that want to use it.  But connection_ap_attach_pending() doesn't

       * actually attach streams to a C_ESTABLISH_REND circuit-- streams

       * don't get attached until the circuit is in C_REND_JOINED... so

       * we can't clear isolation now.

       */

      /* Start building an intro circ if we don't have one yet. */

      connection_ap_attach_pending();

      /* This isn't a call to circuit_try_attaching_streams because a

       * circuit in _C_ESTABLISH_REND state isn't connected to its

       * hidden service yet, thus we can't attach streams to it yet,

       * thus circuit_try_attaching_streams would always clear the

       * circuit's isolation state.  circuit_try_attaching_streams is

       * called later, when the rend circ enters _C_REND_JOINED

       * state. */

      break;

    case CIRCUIT_PURPOSE_C_INTRODUCING:

      rend_client_introcirc_has_opened(circ);
@@ -1033,8 +1030,7 @@ circuit_has_opened(origin_circuit_t *circ) 
    case CIRCUIT_PURPOSE_C_GENERAL:

      /* Tell any AP connections that have been waiting for a new

       * circuit that one is ready. */

      can_try_clearing_isolation = 1;

      connection_ap_attach_pending();

      circuit_try_attaching_streams(circ);

      break;

    case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:

      /* at Bob, waiting for introductions */
@@ -1051,12 +1047,15 @@ circuit_has_opened(origin_circuit_t *circ) 
     * This won't happen in normal operation, but might happen if the

     * controller did it. Just let it slide. */

  }

}



/** If the stream-isolation state of <b>circ</b> can be cleared, clear

 * it.  Return non-zero iff <b>circ</b>'s isolation state was cleared. */

static int

circuit_try_clearing_isolation_state(origin_circuit_t *circ)

{

  if (/* The circuit may have become non-open if it was cannibalized.*/

      circ->_base.state == CIRCUIT_STATE_OPEN &&

      /* Only if the purpose is clearable, and only if we haven't tried

       * to clear isolation yet, do we try. */

      can_try_clearing_isolation && !tried_clearing_isolation &&

      /* If !isolation_values_set, there is nothing to clear. */

      circ->isolation_values_set &&

      /* It's not legal to clear a circuit's isolation info if it's ever had
@@ -1066,8 +1065,26 @@ circuit_has_opened(origin_circuit_t *circ) 
     * we didn't manage to attach any streams to it, then we can

     * and should clear it and try again. */

    circuit_clear_isolation(circ);

    tried_clearing_isolation = 1;

    goto again;

    return 1;

  } else {

    return 0;

  }

}



/** Called when a circuit becomes ready for streams to be attached to

 * it. */

void

circuit_try_attaching_streams(origin_circuit_t *circ)

{

  /* Attach streams to this circuit if we can. */

  connection_ap_attach_pending();



  /* The call to circuit_try_clearing_isolation_state here will do

   * nothing and return 0 if we didn't attach any streams to circ

   * above. */

  if (circuit_try_clearing_isolation_state(circ)) {

    /* Maybe *now* we can attach some streams to this circuit. */

    connection_ap_attach_pending();

  }

}

src/or/circuituse.h

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ void reset_bandwidth_test(void); 
int circuit_enough_testing_circs(void);



void circuit_has_opened(origin_circuit_t *circ);

void circuit_try_attaching_streams(origin_circuit_t *circ);

void circuit_build_failed(origin_circuit_t *circ);



/** Flag to set when a circuit should have only a single hop. */