/* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2019, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file circuitstats.h * \brief Header file for circuitstats.c **/ #ifndef TOR_CIRCUITSTATS_H #define TOR_CIRCUITSTATS_H const circuit_build_times_t *get_circuit_build_times(void); circuit_build_times_t *get_circuit_build_times_mutable(void); double get_circuit_build_close_time_ms(void); double get_circuit_build_timeout_ms(void); int circuit_build_times_disabled(const or_options_t *options); int circuit_build_times_disabled_(const or_options_t *options, int ignore_consensus); /** A build_time_t is milliseconds */ typedef uint32_t build_time_t; int circuit_build_times_enough_to_compute(const circuit_build_times_t *cbt); void circuit_build_times_update_state(const circuit_build_times_t *cbt, or_state_t *state); int circuit_build_times_parse_state(circuit_build_times_t *cbt, or_state_t *state); void circuit_build_times_count_timeout(circuit_build_times_t *cbt, int did_onehop); int circuit_build_times_count_close(circuit_build_times_t *cbt, int did_onehop, time_t start_time); void circuit_build_times_set_timeout(circuit_build_times_t *cbt); int circuit_build_times_add_time(circuit_build_times_t *cbt, build_time_t time); int circuit_build_times_needs_circuits(const circuit_build_times_t *cbt); void circuit_build_times_handle_completed_hop(origin_circuit_t *circ); int circuit_build_times_needs_circuits_now(const circuit_build_times_t *cbt); void circuit_build_times_init(circuit_build_times_t *cbt); void circuit_build_times_free_timeouts(circuit_build_times_t *cbt); void circuit_build_times_new_consensus_params(circuit_build_times_t *cbt, networkstatus_t *ns); double circuit_build_times_timeout_rate(const circuit_build_times_t *cbt); double circuit_build_times_close_rate(const circuit_build_times_t *cbt); void circuit_build_times_update_last_circ(circuit_build_times_t *cbt); void circuit_build_times_mark_circ_as_measurement_only(origin_circuit_t *circ); /** Total size of the circuit timeout history to accumulate. * 1000 is approx 2.5 days worth of continual-use circuits. */ #define CBT_NCIRCUITS_TO_OBSERVE 1000 /** Width of the histogram bins in milliseconds */ #define CBT_BIN_WIDTH ((build_time_t)50) /** Number of modes to use in the weighted-avg computation of Xm */ #define CBT_DEFAULT_NUM_XM_MODES 3 #define CBT_MIN_NUM_XM_MODES 1 #define CBT_MAX_NUM_XM_MODES 20 /** * CBT_BUILD_ABANDONED is our flag value to represent a force-closed * circuit (Aka a 'right-censored' pareto value). */ #define CBT_BUILD_ABANDONED ((build_time_t)(INT32_MAX-1)) #define CBT_BUILD_TIME_MAX ((build_time_t)(INT32_MAX)) /** Save state every 10 circuits */ #define CBT_SAVE_STATE_EVERY 10 /* Circuit build times consensus parameters */ /** * How long to wait before actually closing circuits that take too long to * build in terms of CDF quantile. */ #define CBT_DEFAULT_CLOSE_QUANTILE 95 #define CBT_MIN_CLOSE_QUANTILE CBT_MIN_QUANTILE_CUTOFF #define CBT_MAX_CLOSE_QUANTILE CBT_MAX_QUANTILE_CUTOFF /** * How many circuits count as recent when considering if the * connection has gone gimpy or changed. */ #define CBT_DEFAULT_RECENT_CIRCUITS 20 #define CBT_MIN_RECENT_CIRCUITS 3 #define CBT_MAX_RECENT_CIRCUITS 1000 /** * Maximum count of timeouts that finish the first hop in the past * RECENT_CIRCUITS before calculating a new timeout. * * This tells us whether to abandon timeout history and set * the timeout back to whatever circuit_build_times_get_initial_timeout() * gives us. */ #define CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT (CBT_DEFAULT_RECENT_CIRCUITS*9/10) #define CBT_MIN_MAX_RECENT_TIMEOUT_COUNT 3 #define CBT_MAX_MAX_RECENT_TIMEOUT_COUNT 10000 /** Minimum circuits before estimating a timeout */ #define CBT_DEFAULT_MIN_CIRCUITS_TO_OBSERVE 100 #define CBT_MIN_MIN_CIRCUITS_TO_OBSERVE 1 #define CBT_MAX_MIN_CIRCUITS_TO_OBSERVE 10000 /** Cutoff percentile on the CDF for our timeout estimation. */ #define CBT_DEFAULT_QUANTILE_CUTOFF 80 #define CBT_MIN_QUANTILE_CUTOFF 10 #define CBT_MAX_QUANTILE_CUTOFF 99 double circuit_build_times_quantile_cutoff(void); /** How often in seconds should we build a test circuit */ #define CBT_DEFAULT_TEST_FREQUENCY 10 #define CBT_MIN_TEST_FREQUENCY 1 #define CBT_MAX_TEST_FREQUENCY INT32_MAX /** Lowest allowable value for CircuitBuildTimeout in milliseconds */ #define CBT_DEFAULT_TIMEOUT_MIN_VALUE (1500) #define CBT_MIN_TIMEOUT_MIN_VALUE 500 #define CBT_MAX_TIMEOUT_MIN_VALUE INT32_MAX /** Initial circuit build timeout in milliseconds */ #define CBT_DEFAULT_TIMEOUT_INITIAL_VALUE (60*1000) #define CBT_MIN_TIMEOUT_INITIAL_VALUE CBT_MIN_TIMEOUT_MIN_VALUE #define CBT_MAX_TIMEOUT_INITIAL_VALUE INT32_MAX int32_t circuit_build_times_initial_timeout(void); #if CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT < CBT_MIN_MAX_RECENT_TIMEOUT_COUNT #error "RECENT_CIRCUITS is set too low." #endif #ifdef CIRCUITSTATS_PRIVATE STATIC double circuit_build_times_calculate_timeout(circuit_build_times_t *cbt, double quantile); STATIC int circuit_build_times_update_alpha(circuit_build_times_t *cbt); STATIC void circuit_build_times_reset(circuit_build_times_t *cbt); /* Network liveness functions */ STATIC int circuit_build_times_network_check_changed( circuit_build_times_t *cbt); #endif /* defined(CIRCUITSTATS_PRIVATE) */ #ifdef TOR_UNIT_TESTS build_time_t circuit_build_times_generate_sample(circuit_build_times_t *cbt, double q_lo, double q_hi); double circuit_build_times_cdf(circuit_build_times_t *cbt, double x); void circuit_build_times_initial_alpha(circuit_build_times_t *cbt, double quantile, double time_ms); void circuitbuild_running_unit_tests(void); #endif /* defined(TOR_UNIT_TESTS) */ /* Network liveness functions */ void circuit_build_times_network_is_live(circuit_build_times_t *cbt); int circuit_build_times_network_check_live(const circuit_build_times_t *cbt); void circuit_build_times_network_circ_success(circuit_build_times_t *cbt); #ifdef CIRCUITSTATS_PRIVATE /** Information about the state of our local network connection */ typedef struct { /** The timestamp we last completed a TLS handshake or received a cell */ time_t network_last_live; /** If the network is not live, how many timeouts has this caused? */ int nonlive_timeouts; /** Circular array of circuits that have made it to the first hop. Slot is * 1 if circuit timed out, 0 if circuit succeeded */ int8_t *timeouts_after_firsthop; /** Number of elements allocated for the above array */ int num_recent_circs; /** Index into circular array. */ int after_firsthop_idx; } network_liveness_t; /** Structure for circuit build times history */ struct circuit_build_times_s { /** The circular array of recorded build times in milliseconds */ build_time_t circuit_build_times[CBT_NCIRCUITS_TO_OBSERVE]; /** Current index in the circuit_build_times circular array */ int build_times_idx; /** Total number of build times accumulated. Max CBT_NCIRCUITS_TO_OBSERVE */ int total_build_times; /** Information about the state of our local network connection */ network_liveness_t liveness; /** Last time we built a circuit. Used to decide to build new test circs */ time_t last_circ_at; /** "Minimum" value of our pareto distribution (actually mode) */ build_time_t Xm; /** alpha exponent for pareto dist. */ double alpha; /** Have we computed a timeout? */ int have_computed_timeout; /** The exact value for that timeout in milliseconds. Stored as a double * to maintain precision from calculations to and from quantile value. */ double timeout_ms; /** How long we wait before actually closing the circuit. */ double close_ms; /** Total succeeded counts. Old measurements may be scaled downward if * we've seen a lot of circuits. */ uint32_t num_circ_succeeded; /** Total timeout counts. Old measurements may be scaled downward if * we've seen a lot of circuits. */ uint32_t num_circ_timeouts; /** Total closed counts. Old measurements may be scaled downward if * we've seen a lot of circuits.*/ uint32_t num_circ_closed; }; #endif /* defined(CIRCUITSTATS_PRIVATE) */ #endif /* !defined(TOR_CIRCUITSTATS_H) */