Also allow C_MEASURE_TIMEOUT circuits to lack guard state.

Fixes a case of 21007; bugfix on 0.3.0.1-alpha when prop271 was
implemented. Found by toralf.
This commit is contained in:
Nick Mathewson 2017-02-24 11:12:21 -05:00
parent 823fb68a14
commit 5e08fc8557
2 changed files with 26 additions and 1 deletions

4
changes/bug21007_case2 Normal file
View File

@ -0,0 +1,4 @@
o Minor bugfixes (guards):
- Don't warn about a missing guard state on timeout-measurement
circuits: they aren't supposed to be using guards. Fixes an
instance of bug 21007; bugfix on 0.3.0.1-alpha.

View File

@ -892,6 +892,27 @@ circuit_pick_extend_handshake(uint8_t *cell_type_out,
}
}
/**
* Return true iff <b>purpose</b> is a purpose for a circuit which is
* allowed to have no guard configured, even if the circuit is multihop
* and guards are enabled.
*/
static int
circuit_purpose_may_omit_guard(int purpose)
{
switch (purpose) {
case CIRCUIT_PURPOSE_TESTING:
case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
/* Testing circuits may omit guards because they're measuring
* liveness or performance, and don't want guards to interfere. */
return 1;
default:
/* All other multihop circuits should use guards if guards are
* enabled. */
return 0;
}
}
/** This is the backbone function for building circuits.
*
* If circ's first hop is closed, then we need to build a create
@ -969,7 +990,7 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
guard_usable_t r;
if (! circ->guard_state) {
if (circuit_get_cpath_len(circ) != 1 &&
circ->base_.purpose != CIRCUIT_PURPOSE_TESTING &&
! circuit_purpose_may_omit_guard(circ->base_.purpose) &&
get_options()->UseEntryGuards) {
log_warn(LD_BUG, "%d-hop circuit %p with purpose %d has no "
"guard state",