Merge branch 'dgoulet/bug21302_030_01_squashed' (9d5a9feb) · Commits · The Tor Project / Core / Tor

changes/bug21302

0 → 100644

+8 −0

Original line number	Diff line number	Diff line
		o Minor bugfixes (hidden service):
		- Two possible underflow which would ultimately lead to creating a lot of
		introduction points circuits and closing them in a non stop loop. Fixes
		bug 21302; bugfix on tor-0.2.7.2-alpha.
		- Cleanup expiring intro point nodes if no circuit is associated to it
		anymore. It was causing, rarely, the service to not open enough
		introduction points circuit in the case we had dead expiring nodes.;
		bugfix on tor-0.2.7.2-alpha.

src/or/rendservice.c

+35 −12

Original line number	Diff line number	Diff line
		@@ -3227,6 +3227,7 @@ rend_service_intro_has_opened(origin_circuit_t *circuit)
		rend_service_t *service;
		char buf[RELAY_PAYLOAD_SIZE];
		char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
		unsigned int expiring_nodes_len, num_ip_circuits, valid_ip_circuits = 0;
		int reason = END_CIRC_REASON_TORPROTOCOL;
		const char *rend_pk_digest;

		@@ -3248,13 +3249,22 @@ rend_service_intro_has_opened(origin_circuit_t *circuit)
		goto err;
		}

		/* Take the current amount of expiring nodes and the current amount of IP
		* circuits and compute how many valid IP circuits we have. */
		expiring_nodes_len = (unsigned int) smartlist_len(service->expiring_nodes);
		num_ip_circuits = count_intro_point_circuits(service);
		/* Let's avoid an underflow. The valid_ip_circuits is initialized to 0 in
		* case this condition turns out false because it means that all circuits
		* are expiring so we need to keep this circuit. */
		if (num_ip_circuits > expiring_nodes_len) {
		valid_ip_circuits = num_ip_circuits - expiring_nodes_len;
		}

		/* If we already have enough introduction circuits for this service,
		* redefine this one as a general circuit or close it, depending.
		* Substract the amount of expiring nodes here since the circuits are
		* Substract the amount of expiring nodes here because the circuits are
		* still opened. */
		if ((count_intro_point_circuits(service) -
		smartlist_len(service->expiring_nodes)) >
		service->n_intro_points_wanted) {
		if (valid_ip_circuits > service->n_intro_points_wanted) {
		const or_options_t *options = get_options();
		/* Remove the intro point associated with this circuit, it's being
		* repurposed or closed thus cleanup memory. */
		@@ -3897,6 +3907,19 @@ remove_invalid_intro_points(rend_service_t *service,
		{
		tor_assert(service);

		/* Remove any expired nodes that doesn't have a circuit. */
		SMARTLIST_FOREACH_BEGIN(service->expiring_nodes, rend_intro_point_t *,
		intro) {
		origin_circuit_t *intro_circ =
		find_intro_circuit(intro, service->pk_digest);
		if (intro_circ) {
		continue;
		}
		/* No more circuit, cleanup the into point object. */
		SMARTLIST_DEL_CURRENT(service->expiring_nodes, intro);
		rend_intro_point_free(intro);
		} SMARTLIST_FOREACH_END(intro);

		SMARTLIST_FOREACH_BEGIN(service->intro_nodes, rend_intro_point_t *,
		intro) {
		/* Find the introduction point node object. */
		@@ -4072,17 +4095,17 @@ rend_consider_services_intro_points(void)
		/* Avoid mismatched signed comparaison below. */
		intro_nodes_len = (unsigned int) smartlist_len(service->intro_nodes);

		/* Quiescent state, no node expiring and we have more or the amount of
		* wanted node for this service. Proceed to the next service. Could be
		* more because we launch two preemptive circuits if our intro nodes
		* list is empty. */
		if (smartlist_len(service->expiring_nodes) == 0 &&
		intro_nodes_len >= service->n_intro_points_wanted) {
		/* Quiescent state, we have more or the equal amount of wanted node for
		* this service. Proceed to the next service. We can have more nodes
		* because we launch extra preemptive circuits if our intro nodes list was
		* originally empty for performance reasons. */
		if (intro_nodes_len >= service->n_intro_points_wanted) {
		continue;
		}

		/* Number of intro points we want to open which is the wanted amount
		* minus the current amount of valid nodes. */
		/* Number of intro points we want to open which is the wanted amount minus
		* the current amount of valid nodes. We know that this won't underflow
		* because of the check above. */
		n_intro_points_to_open = service->n_intro_points_wanted - intro_nodes_len;
		if (intro_nodes_len == 0) {
		/* We want to end up with n_intro_points_wanted intro points, but if