diff --git a/changes/close_begindir_circs b/changes/close_begindir_circs new file mode 100644 index 0000000000000000000000000000000000000000..3b1ee879c57790ca6e8c517e4a562533e43767e0 --- /dev/null +++ b/changes/close_begindir_circs @@ -0,0 +1,7 @@ + o Major bugfixes: + - Relays now close idle circuits early if it looks like they were + intended for directory fetches. Such circuits are unlikely to + be re-used, and tens of thousands of them were piling up at the + fast relays, causing the relays to run out of sockets and memory. + Bugfix on 0.2.0.22-rc (where clients started tunneling their + directory fetches over TLS). diff --git a/src/or/circuituse.c b/src/or/circuituse.c index 9eda9e2480cd8c7e2b6dfc88429b0bce60d59142..7e47e60559d3f8b30e99d767cc2d5912441d4e79 100644 --- a/src/or/circuituse.c +++ b/src/or/circuituse.c @@ -17,7 +17,7 @@ extern circuit_t *global_circuitlist; /* from circuitlist.c */ /********* END VARIABLES ************/ -static void circuit_expire_old_circuits(time_t now); +static void circuit_expire_old_circuits_clientside(time_t now); static void circuit_increment_failure_count(void); long int lround(double x); @@ -567,7 +567,7 @@ circuit_build_needed_circs(time_t now) time_to_new_circuit = now + options->NewCircuitPeriod; if (proxy_mode(get_options())) addressmap_clean(now); - circuit_expire_old_circuits(now); + circuit_expire_old_circuits_clientside(now); #if 0 /* disable for now, until predict-and-launch-new can cull leftovers */ circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL); @@ -656,7 +656,7 @@ circuit_detach_stream(circuit_t *circ, edge_connection_t *conn) * for too long and has no streams on it: mark it for close. */ static void -circuit_expire_old_circuits(time_t now) +circuit_expire_old_circuits_clientside(time_t now) { circuit_t *circ; time_t cutoff; @@ -696,6 +696,53 @@ circuit_expire_old_circuits(time_t now) } } +/** How long do we wait before killing circuits with the properties + * described below? + * + * Probably we could choose a number here as low as 5 to 10 seconds, + * since these circs are used for begindir, and a) generally you either + * ask another begindir question right after or you don't for a long time, + * b) clients at least through 0.2.1.x choose from the whole set of + * directory mirrors at each choice, and c) re-establishing a one-hop + * circuit via create-fast is a light operation assuming the TLS conn is + * still there. + * + * I expect "b" to go away one day when we move to using directory + * guards, but I think "a" and "c" are good enough reasons that a low + * number is safe even then. + */ +#define IDLE_ONE_HOP_CIRC_TIMEOUT 60 + +/** Find each non-origin circuit that has been unused for too long, + * has no streams on it, used a create_fast, and ends here: mark it + * for close. + */ +void +circuit_expire_old_circuits_serverside(time_t now) +{ + circuit_t *circ; + or_circuit_t *or_circ; + time_t cutoff = now - IDLE_ONE_HOP_CIRC_TIMEOUT; + + for (circ = global_circuitlist; circ; circ = circ->next) { + if (circ->marked_for_close || CIRCUIT_IS_ORIGIN(circ)) + continue; + or_circ = TO_OR_CIRCUIT(circ); + /* If the circuit has been idle for too long, and there are no streams + * on it, and it ends here, and it used a create_fast, mark it for close. + */ + if (or_circ->is_first_hop && !circ->n_conn && + !or_circ->n_streams && !or_circ->resolving_streams && + or_circ->p_conn && + or_circ->p_conn->timestamp_last_added_nonpadding <= cutoff) { + log_info(LD_CIRC, "Closing circ_id %d (empty %d secs ago)", + or_circ->p_circ_id, + (int)(now - or_circ->p_conn->timestamp_last_added_nonpadding)); + circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); + } + } +} + /** Number of testing circuits we want open before testing our bandwidth. */ #define NUM_PARALLEL_TESTING_CIRCS 4 diff --git a/src/or/main.c b/src/or/main.c index ccc25c5636c1bb3f0e83dea29a7fff1ea6b0c06a..017f72bacad2b55836ed25ebddb6e7a0c74c4885 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -1134,6 +1134,10 @@ run_scheduled_events(time_t now) if (have_dir_info && !we_are_hibernating()) circuit_build_needed_circs(now); + /* every 10 seconds, but not at the same second as other such events */ + if (now % 10 == 5) + circuit_expire_old_circuits_serverside(now); + /** 5. We do housekeeping for each connection... */ connection_or_set_bad_connections(); for (i=0;i<smartlist_len(connection_array);i++) { diff --git a/src/or/or.h b/src/or/or.h index 46885482a84289871f88bc2f6ec07d12936c57b4..9c613d28d10a940918f534798660572b512cc3e3 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -3230,6 +3230,8 @@ int circuit_conforms_to_options(const origin_circuit_t *circ, void circuit_build_needed_circs(time_t now); void circuit_detach_stream(circuit_t *circ, edge_connection_t *conn); +void circuit_expire_old_circuits_serverside(time_t now); + void reset_bandwidth_test(void); int circuit_enough_testing_circs(void);