Merge remote-tracking branch 'mikeperry/bug6647'

This commit is contained in:
Nick Mathewson 2012-08-27 16:23:19 -04:00
commit f40378118c
2 changed files with 52 additions and 14 deletions

7
changes/bug6647 Normal file
View File

@ -0,0 +1,7 @@
o Minor bugfixes:
- Prevent rounding error in path bias counts when scaling
them down, and use the correct scale factor default.
Bugfix against 0.2.3.17-beta.
- Demote some path bias related log messages down a level
and make others less scary sounding.
Bugfix against 0.2.3.17-beta.

View File

@ -2608,12 +2608,12 @@ pathbias_get_scale_threshold(const or_options_t *options)
static int
pathbias_get_scale_factor(const or_options_t *options)
{
#define DFLT_PATH_BIAS_SCALE_FACTOR 4
#define DFLT_PATH_BIAS_SCALE_FACTOR 2
if (options->PathBiasScaleFactor >= 1)
return options->PathBiasScaleFactor;
else
return networkstatus_get_param(NULL, "pb_scalefactor",
DFLT_PATH_BIAS_SCALE_THRESHOLD, 1, INT32_MAX);
DFLT_PATH_BIAS_SCALE_FACTOR, 1, INT32_MAX);
}
static const char *
@ -2645,6 +2645,14 @@ pathbias_count_first_hop(origin_circuit_t *circ)
RATELIM_INIT(FIRST_HOP_NOTICE_INTERVAL);
char *rate_msg = NULL;
/* We can't do path bias accounting without entry guards.
* Testing and controller circuits also have no guards. */
if (get_options()->UseEntryGuards == 0 ||
circ->_base.purpose == CIRCUIT_PURPOSE_TESTING ||
circ->_base.purpose == CIRCUIT_PURPOSE_CONTROLLER) {
return 0;
}
/* Completely ignore one hop circuits */
if (circ->build_state->onehop_tunnel) {
tor_assert(circ->build_state->desired_path_len == 1);
@ -2656,7 +2664,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
if (circ->has_opened && circ->path_state != PATH_STATE_DID_FIRST_HOP) {
if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"Opened circuit is in strange path state %s. "
"Circuit is a %s currently %s. %s",
pathbias_state_to_string(circ->path_state),
@ -2683,7 +2691,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
} else {
if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"Unopened circuit has strange path state %s. "
"Circuit is a %s currently %s. %s",
pathbias_state_to_string(circ->path_state),
@ -2695,7 +2703,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
} else {
if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"Unopened circuit has no known guard. "
"Circuit is a %s currently %s. %s",
circuit_purpose_to_string(circ->_base.purpose),
@ -2709,7 +2717,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
if (circ->path_state == PATH_STATE_NEW_CIRC) {
if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"A %s circuit is in cpath state %d (opened: %d). "
"Circuit is a %s currently %s. %s",
pathbias_state_to_string(circ->path_state),
@ -2739,6 +2747,14 @@ pathbias_count_success(origin_circuit_t *circ)
RATELIM_INIT(SUCCESS_NOTICE_INTERVAL);
char *rate_msg = NULL;
/* We can't do path bias accounting without entry guards.
* Testing and controller circuits also have no guards. */
if (get_options()->UseEntryGuards == 0 ||
circ->_base.purpose == CIRCUIT_PURPOSE_TESTING ||
circ->_base.purpose == CIRCUIT_PURPOSE_CONTROLLER) {
return;
}
/* Ignore one hop circuits */
if (circ->build_state->onehop_tunnel) {
tor_assert(circ->build_state->desired_path_len == 1);
@ -2761,7 +2777,7 @@ pathbias_count_success(origin_circuit_t *circ)
} else {
if ((rate_msg = rate_limit_log(&success_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"Succeeded circuit is in strange path state %s. "
"Circuit is a %s currently %s. %s",
pathbias_state_to_string(circ->path_state),
@ -2772,15 +2788,18 @@ pathbias_count_success(origin_circuit_t *circ)
}
if (guard->first_hops < guard->circuit_successes) {
log_warn(LD_BUG, "Unexpectedly high circuit_successes (%u/%u) "
log_notice(LD_BUG, "Unexpectedly high circuit_successes (%u/%u) "
"for guard %s=%s",
guard->circuit_successes, guard->first_hops,
guard->nickname, hex_str(guard->identity, DIGEST_LEN));
}
} else {
/* In rare cases, CIRCUIT_PURPOSE_TESTING can get converted to
* CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT and have no guards here.
* No need to log that case. */
} else if (circ->_base.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
if ((rate_msg = rate_limit_log(&success_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"Completed circuit has no known guard. "
"Circuit is a %s currently %s. %s",
circuit_purpose_to_string(circ->_base.purpose),
@ -2792,7 +2811,7 @@ pathbias_count_success(origin_circuit_t *circ)
if (circ->path_state != PATH_STATE_SUCCEEDED) {
if ((rate_msg = rate_limit_log(&success_notice_limit,
approx_time()))) {
log_notice(LD_BUG,
log_info(LD_BUG,
"Opened circuit is in strange path state %s. "
"Circuit is a %s currently %s. %s",
pathbias_state_to_string(circ->path_state),
@ -2822,9 +2841,11 @@ entry_guard_inc_first_hop_count(entry_guard_t *guard)
if (guard->circuit_successes/((double)guard->first_hops)
< pathbias_get_disable_rate(options)) {
/* This message is currently disabled by default. */
log_warn(LD_PROTOCOL,
"Extremely low circuit success rate %u/%u for guard %s=%s. "
"This might indicate an attack, or a bug.",
"This indicates either an overloaded guard, an attack, or "
"a bug.",
guard->circuit_successes, guard->first_hops, guard->nickname,
hex_str(guard->identity, DIGEST_LEN));
@ -2845,8 +2866,18 @@ entry_guard_inc_first_hop_count(entry_guard_t *guard)
/* If we get a ton of circuits, just scale everything down */
if (guard->first_hops > (unsigned)pathbias_get_scale_threshold(options)) {
const int scale_factor = pathbias_get_scale_factor(options);
guard->first_hops /= scale_factor;
guard->circuit_successes /= scale_factor;
/* For now, only scale if there will be no rounding error...
* XXX024: We want to switch to a real moving average for 0.2.4. */
if ((guard->first_hops % scale_factor) == 0 &&
(guard->circuit_successes % scale_factor) == 0) {
log_info(LD_PROTOCOL,
"Scaling pathbias counts to (%u/%u)/%d for guard %s=%s",
guard->circuit_successes, guard->first_hops,
scale_factor, guard->nickname, hex_str(guard->identity,
DIGEST_LEN));
guard->first_hops /= scale_factor;
guard->circuit_successes /= scale_factor;
}
}
guard->first_hops++;
log_info(LD_PROTOCOL, "Got success count %u/%u for guard %s=%s",