commit 4e42a8a2f20e501f9236452b41939964e6d942cf
Author: Mike Perry <mikeperry-git(a)fscked.org>
Date: Thu Aug 16 16:29:19 2012 -0700
Address Nick's comments from code review.
Also promote log messages to notice and rate-limit them.
---
changes/bug6475 | 6 +
src/or/circuitbuild.c | 284 ++++++++++++++++++++++++++++++++++---------------
src/or/or.h | 13 ++-
3 files changed, 217 insertions(+), 86 deletions(-)
diff --git a/changes/bug6475 b/changes/bug6475
new file mode 100644
index 0000000..67bab99
--- /dev/null
+++ b/changes/bug6475
@@ -0,0 +1,6 @@
+ o Minor bugfixes:
+ - Add internal circuit construction state to protect against
+ the noisy warn message "Unexpectedly high circuit_successes".
+ Also add some additional rate-limited notice messages to help
+ determine the root cause of the warn. Fixes bug 6475.
+ Bugfix against 0.2.3.17-beta.
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 7ac2b97..2fa3dd5 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -135,6 +135,9 @@ static entry_guard_t *entry_guard_get_by_id_digest(const char *digest);
static void bridge_free(bridge_info_t *bridge);
+static int entry_guard_inc_first_hop_count(entry_guard_t *guard);
+static void pathbias_count_success(origin_circuit_t *circ);
+
/**
* This function decides if CBT learning should be disabled. It returns
* true if one or more of the following four conditions are met:
@@ -2285,44 +2288,11 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
}
log_info(LD_CIRC,"circuit built!");
circuit_reset_failure_count(0);
- /* Don't count cannibalized or onehop circs for path bias */
+
if (circ->build_state->onehop_tunnel || circ->has_opened) {
control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS, 0);
- } else {
- entry_guard_t *guard =
- entry_guard_get_by_id_digest(circ->_base.n_conn->identity_digest);
-
- if (guard) {
- if (circ->path_state == PATH_STATE_DID_FIRST_HOP) {
- circ->path_state = PATH_STATE_SUCCEEDED;
- guard->circuit_successes++;
-
- log_info(LD_PROTOCOL, "Got success count %u/%u for guard %s=%s",
- guard->circuit_successes, guard->first_hops,
- guard->nickname, hex_str(guard->identity, DIGEST_LEN));
- } else {
- log_info(LD_BUG,
- "Succeeded circuit has strange path state %d. "
- "Circuit is a %s currently %s.",
- circ->path_state,
- circuit_purpose_to_string(circ->_base.purpose),
- circuit_state_to_string(circ->_base.state));
- }
-
- if (guard->first_hops < guard->circuit_successes) {
- log_warn(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 {
- log_info(LD_BUG,
- "Completed circuit has no known guard. "
- "Circuit is a %s currently %s.",
- circuit_purpose_to_string(circ->_base.purpose),
- circuit_state_to_string(circ->_base.state));
- }
}
+
if (!can_complete_circuit && !circ->build_state->onehop_tunnel) {
const or_options_t *options = get_options();
can_complete_circuit=1;
@@ -2338,6 +2308,8 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
consider_testing_reachability(1, 1);
}
}
+
+ pathbias_count_success(circ);
circuit_rep_hist_note_result(circ);
circuit_has_opened(circ); /* do other actions as necessary */
@@ -2637,6 +2609,194 @@ pathbias_get_scale_factor(const or_options_t *options)
DFLT_PATH_BIAS_SCALE_THRESHOLD, 1, INT32_MAX);
}
+const char *
+pathbias_state_to_string(path_state_t state)
+{
+ switch(state) {
+ case PATH_STATE_NEW_CIRC:
+ return "new";
+ case PATH_STATE_DID_FIRST_HOP:
+ return "first hop";
+ case PATH_STATE_SUCCEEDED:
+ return "succeeded";
+ }
+
+ return "unknown";
+}
+
+
+/**
+ * Check our circuit state to see if this is a successful first hop.
+ * If so, record it in the current guard's path bias first_hop count.
+ *
+ * Also check for several potential error cases for bug #6475.
+ */
+static int
+pathbias_count_first_hop(origin_circuit_t *circ)
+{
+#define FIRST_HOP_NOTICE_INTERVAL (600)
+ static ratelim_t first_hop_notice_limit = RATELIM_INIT(FIRST_HOP_NOTICE_INTERVAL);
+ char *rate_msg = NULL;
+
+ /* Completely ignore one hop circuits */
+ if (circ->build_state->onehop_tunnel) {
+ tor_assert(circ->build_state->desired_path_len == 1);
+ return 0;
+ }
+
+ if (circ->cpath->state == CPATH_STATE_AWAITING_KEYS) {
+ /* Help track down the real cause of bug #6475: */
+ 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,
+ "Opened circuit is in strange path state %s. "
+ "Circuit is a %s currently %s. %s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+
+ /* Don't count cannibalized circs for path bias */
+ if (!circ->has_opened) {
+ entry_guard_t *guard;
+
+ guard = entry_guard_get_by_id_digest(
+ circ->_base.n_conn->identity_digest);
+ if (guard) {
+ if (circ->path_state == PATH_STATE_NEW_CIRC) {
+ circ->path_state = PATH_STATE_DID_FIRST_HOP;
+
+ if (entry_guard_inc_first_hop_count(guard) < 0) {
+ /* Bogus guard; we already warned. */
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ } else {
+ if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
+ approx_time()))) {
+ log_notice(LD_BUG,
+ "Unopened circuit has strange path state %s. "
+ "Circuit is a %s currently %s. %s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+ } else {
+ if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
+ approx_time()))) {
+ log_notice(LD_BUG,
+ "Unopened circuit has no known guard. "
+ "Circuit is a %s currently %s. %s",
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+ }
+ } else {
+ /* Help track down the real cause of bug #6475: */
+ if (circ->path_state == PATH_STATE_NEW_CIRC) {
+ if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
+ approx_time()))) {
+ log_notice(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),
+ circ->cpath->state, circ->has_opened,
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * Check our circuit state to see if this is a successful circuit
+ * completion. If so, record it in the current guard's path bias
+ * success count.
+ *
+ * Also check for several potential error cases for bug #6475.
+ */
+static void
+pathbias_count_success(origin_circuit_t *circ)
+{
+#define SUCCESS_NOTICE_INTERVAL (600)
+ static ratelim_t success_notice_limit = RATELIM_INIT(SUCCESS_NOTICE_INTERVAL);
+ char *rate_msg = NULL;
+
+ /* Ignore one hop circuits */
+ if (circ->build_state->onehop_tunnel) {
+ tor_assert(circ->build_state->desired_path_len == 1);
+ return;
+ }
+
+ /* Don't count cannibalized/reused circs for path bias */
+ if (!circ->has_opened) {
+ entry_guard_t *guard =
+ entry_guard_get_by_id_digest(circ->_base.n_conn->identity_digest);
+
+ if (guard) {
+ if (circ->path_state == PATH_STATE_DID_FIRST_HOP) {
+ circ->path_state = PATH_STATE_SUCCEEDED;
+ guard->circuit_successes++;
+
+ log_info(LD_PROTOCOL, "Got success count %u/%u for guard %s=%s",
+ guard->circuit_successes, guard->first_hops,
+ guard->nickname, hex_str(guard->identity, DIGEST_LEN));
+ } else {
+ if ((rate_msg = rate_limit_log(&success_notice_limit,
+ approx_time()))) {
+ log_notice(LD_BUG,
+ "Succeeded circuit is in strange path state %s. "
+ "Circuit is a %s currently %s. %s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+
+ if (guard->first_hops < guard->circuit_successes) {
+ log_warn(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 {
+ if ((rate_msg = rate_limit_log(&success_notice_limit,
+ approx_time()))) {
+ log_notice(LD_BUG,
+ "Completed circuit has no known guard. "
+ "Circuit is a %s currently %s. %s",
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+ } else {
+ if (circ->path_state != PATH_STATE_SUCCEEDED) {
+ if ((rate_msg = rate_limit_log(&success_notice_limit,
+ approx_time()))) {
+ log_notice(LD_BUG,
+ "Opened circuit is in strange path state %s. "
+ "Circuit is a %s currently %s. %s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->_base.purpose),
+ circuit_state_to_string(circ->_base.state),
+ rate_msg);
+ }
+ }
+ }
+}
+
+
/** Increment the number of times we successfully extended a circuit to
* 'guard', first checking if the failure rate is high enough that we should
* eliminate the guard. Return -1 if the guard looks no good; return 0 if the
@@ -2704,60 +2864,14 @@ circuit_finish_handshake(origin_circuit_t *circ, uint8_t reply_type,
{
char keys[CPATH_KEY_MATERIAL_LEN];
crypt_path_t *hop;
+ int rv;
+
+ if((rv = pathbias_count_first_hop(circ)) < 0)
+ return rv;
if (circ->cpath->state == CPATH_STATE_AWAITING_KEYS) {
hop = circ->cpath;
-
- /* Help track down the real cause of bug #6475: */
- if (circ->has_opened && circ->path_state == PATH_STATE_NEW_CIRC) {
- log_info(LD_BUG,
- "Opened circuit seems new. "
- "Circuit is a %s currently %s.",
- circuit_purpose_to_string(circ->_base.purpose),
- circuit_state_to_string(circ->_base.state));
- }
-
- /* Don't count cannibalized or onehop circs for path bias */
- if (!circ->has_opened && !circ->build_state->onehop_tunnel) {
- entry_guard_t *guard;
-
- guard = entry_guard_get_by_id_digest(
- circ->_base.n_conn->identity_digest);
- if (guard) {
- if (circ->path_state == PATH_STATE_NEW_CIRC) {
- circ->path_state = PATH_STATE_DID_FIRST_HOP;
-
- if (entry_guard_inc_first_hop_count(guard) < 0) {
- /* Bogus guard; we already warned. */
- return -END_CIRC_REASON_TORPROTOCOL;
- }
- } else {
- log_info(LD_BUG,
- "Unopened circuit has strange path state %d. "
- "Circuit is a %s currently %s.",
- circ->path_state,
- circuit_purpose_to_string(circ->_base.purpose),
- circuit_state_to_string(circ->_base.state));
- }
- } else {
- log_info(LD_BUG,
- "Opened circuit has no known guard. "
- "Circuit is a %s currently %s.",
- circuit_purpose_to_string(circ->_base.purpose),
- circuit_state_to_string(circ->_base.state));
- }
- }
} else {
- /* Help track down the real cause of bug #6475: */
- if (circ->path_state == PATH_STATE_NEW_CIRC) {
- log_info(LD_BUG,
- "New circuit is in cpath state %d (opened: %d). "
- "Circuit is a %s currently %s.",
- circ->cpath->state, circ->has_opened,
- circuit_purpose_to_string(circ->_base.purpose),
- circuit_state_to_string(circ->_base.state));
- }
-
hop = onion_next_hop_in_cpath(circ->cpath);
if (!hop) { /* got an extended when we're all done? */
log_warn(LD_PROTOCOL,"got extended when circ already built? Closing.");
diff --git a/src/or/or.h b/src/or/or.h
index 0db6137..d2cafb5 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2596,9 +2596,20 @@ typedef struct circuit_t {
* circuit. */
#define MAX_RELAY_EARLY_CELLS_PER_CIRCUIT 8
+/**
+ * Describes the circuit building process in simplified terms based
+ * on the path bias accounting state for a circuit. Created to prevent
+ * overcounting due to unknown cases of circuit reuse. See Bug #6475.
+ */
typedef enum {
+ /** This circuit is "new". It has not yet completed a first hop
+ * or been counted by the path bias code. */
PATH_STATE_NEW_CIRC = 0,
+ /** This circuit has completed a first hop, and has been counted by
+ * the path bias logic. */
PATH_STATE_DID_FIRST_HOP = 1,
+ /** This circuit has been completely built, and has been counted as
+ * successful by the path bias logic. */
PATH_STATE_SUCCEEDED = 2,
} path_state_t;
@@ -2637,7 +2648,7 @@ typedef struct origin_circuit_t {
/** Kludge to help us prevent the warn in bug #6475 and eventually
* debug why we are not seeing first hops in some cases. */
- path_state_t path_state;
+ path_state_t path_state : 2;
/** Set iff this is a hidden-service circuit which has timed out
* according to our current circuit-build timeout, but which has
