commit 6828a19670080a3d19bdddf1e55d53928d81a410 Author: Mike Perry <mikeperry-git@fscked.org> Date: Wed Jan 30 17:46:25 2013 -0400 Add a tristate to guard against unexpected circ purpose transitions --- src/or/circuitbuild.c | 42 ++++++++++++++++++++++++++++++++++++++++++ src/or/or.h | 12 ++++++++++++ 2 files changed, 54 insertions(+), 0 deletions(-) diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c index 9732a48..ddc11d0 100644 --- a/src/or/circuitbuild.c +++ b/src/or/circuitbuild.c @@ -1352,6 +1352,24 @@ pathbias_should_count(origin_circuit_t *circ) circ->base_.purpose == CIRCUIT_PURPOSE_S_REND_JOINED || (circ->base_.purpose >= CIRCUIT_PURPOSE_C_INTRODUCING && circ->base_.purpose <= CIRCUIT_PURPOSE_C_INTRODUCE_ACKED)) { + + /* Check to see if the shouldcount result has changed due to a + * unexpected purpose change that would affect our results. + * + * The reason we check the path state too here is because for the + * cannibalized versions of these purposes, we count them as successful + * before their purpose change. + */ + if (circ->pathbias_shouldcount == PATHBIAS_SHOULDCOUNT_COUNTED + && circ->path_state != PATH_STATE_ALREADY_COUNTED) { + log_info(LD_BUG, + "Circuit %d is now being ignored despite being counted " + "in the past. Purpose is %s, path state is %s", + circ->global_identifier, + circuit_purpose_to_string(circ->base_.purpose), + pathbias_state_to_string(circ->path_state)); + } + circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_IGNORED; return 0; } @@ -1374,9 +1392,33 @@ pathbias_should_count(origin_circuit_t *circ) } tor_fragile_assert(); } + + /* Check to see if the shouldcount result has changed due to a + * unexpected change that would affect our results */ + if (circ->pathbias_shouldcount == PATHBIAS_SHOULDCOUNT_COUNTED) { + log_info(LD_BUG, + "One-hop circuit %d is now being ignored despite being counted " + "in the past. Purpose is %s, path state is %s", + circ->global_identifier, + circuit_purpose_to_string(circ->base_.purpose), + pathbias_state_to_string(circ->path_state)); + } + circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_IGNORED; return 0; } + /* Check to see if the shouldcount result has changed due to a + * unexpected purpose change that would affect our results */ + if (circ->pathbias_shouldcount == PATHBIAS_SHOULDCOUNT_IGNORED) { + log_info(LD_BUG, + "Circuit %d is now being counted despite being ignored " + "in the past. Purpose is %s, path state is %s", + circ->global_identifier, + circuit_purpose_to_string(circ->base_.purpose), + pathbias_state_to_string(circ->path_state)); + } + circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_COUNTED; + return 1; } diff --git a/src/or/or.h b/src/or/or.h index b5ccd0c..3c962e3 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -2920,6 +2920,18 @@ typedef struct origin_circuit_t { */ ENUM_BF(path_state_t) path_state : 3; + /** + * Tristate variable to guard against pathbias miscounting + * due to circuit purpose transitions changing the decision + * of pathbias_should_count(). This variable is informational + * only. The current results of pathbias_should_count() are + * the official decision for pathbias accounting. + */ + uint8_t pathbias_shouldcount; +#define PATHBIAS_SHOULDCOUNT_UNDECIDED 0 +#define PATHBIAS_SHOULDCOUNT_IGNORED 1 +#define PATHBIAS_SHOULDCOUNT_COUNTED 2 + /** For path probing. Store the temporary probe stream ID * for response comparison */ streamid_t pathbias_probe_id;