commit 5e08fc85570173200935b62de2bffee81fed2fc1 Author: Nick Mathewson nickm@torproject.org Date: Fri Feb 24 11:12:21 2017 -0500

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. --- changes/bug21007_case2 | 4 ++++ src/or/circuitbuild.c | 23 ++++++++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/changes/bug21007_case2 b/changes/bug21007_case2 new file mode 100644 index 0000000..4334444 --- /dev/null +++ b/changes/bug21007_case2 @@ -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. diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c index cd00034..79962e8 100644 --- a/src/or/circuitbuild.c +++ b/src/or/circuitbuild.c @@ -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",