/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2017, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file rephist.c * \brief Basic history and performance-tracking functionality. * * Basic history and performance-tracking functionality to remember * which servers have worked in the past, how much bandwidth we've * been using, which ports we tend to want, and so on; further, * exit port statistics, cell statistics, and connection statistics. * * The history and information tracked in this module could sensibly be * divided into several categories: * * * * The entry points for this module are scattered throughout the * codebase. Sending data, receiving data, connecting to a relay, * losing a connection to a relay, and so on can all trigger a change in * our current stats. Relays also invoke this module in order to * extract their statistics when building routerinfo and extrainfo * objects in router.c. * * TODO: This module should be broken up. * * (The "rephist" name originally stood for "reputation and history". ) **/ #include "or.h" #include "circuitlist.h" #include "circuituse.h" #include "config.h" #include "crypto_rand.h" #include "networkstatus.h" #include "nodelist.h" #include "rephist.h" #include "router.h" #include "routerlist.h" #include "ht.h" #include "channelpadding.h" #include "connection_or.h" #include "statefile.h" static void bw_arrays_init(void); static void predicted_ports_alloc(void); /** Total number of bytes currently allocated in fields used by rephist.c. */ uint64_t rephist_total_alloc=0; /** Number of or_history_t objects currently allocated. */ uint32_t rephist_total_num=0; /** If the total weighted run count of all runs for a router ever falls * below this amount, the router can be treated as having 0 MTBF. */ #define STABILITY_EPSILON 0.0001 /** Value by which to discount all old intervals for MTBF purposes. This * is compounded every STABILITY_INTERVAL. */ #define STABILITY_ALPHA 0.95 /** Interval at which to discount all old intervals for MTBF purposes. */ #define STABILITY_INTERVAL (12*60*60) /* (This combination of ALPHA, INTERVAL, and EPSILON makes it so that an * interval that just ended counts twice as much as one that ended a week ago, * 20X as much as one that ended a month ago, and routers that have had no * uptime data for about half a year will get forgotten.) */ /** History of an OR. */ typedef struct or_history_t { /** When did we start tracking this OR? */ time_t since; /** When did we most recently note a change to this OR? */ time_t changed; /** The address at which we most recently connected to this OR * successfully. */ tor_addr_t last_reached_addr; /** The port at which we most recently connected to this OR successfully */ uint16_t last_reached_port; /* === For MTBF tracking: */ /** Weighted sum total of all times that this router has been online. */ unsigned long weighted_run_length; /** If the router is now online (according to stability-checking rules), * when did it come online? */ time_t start_of_run; /** Sum of weights for runs in weighted_run_length. */ double total_run_weights; /* === For fractional uptime tracking: */ time_t start_of_downtime; unsigned long weighted_uptime; unsigned long total_weighted_time; } or_history_t; /** * This structure holds accounting needed to calculate the padding overhead. */ typedef struct padding_counts_t { /** Total number of cells we have received, including padding */ uint64_t read_cell_count; /** Total number of cells we have sent, including padding */ uint64_t write_cell_count; /** Total number of CELL_PADDING cells we have received */ uint64_t read_pad_cell_count; /** Total number of CELL_PADDING cells we have sent */ uint64_t write_pad_cell_count; /** Total number of read cells on padding-enabled conns */ uint64_t enabled_read_cell_count; /** Total number of sent cells on padding-enabled conns */ uint64_t enabled_write_cell_count; /** Total number of read CELL_PADDING cells on padding-enabled cons */ uint64_t enabled_read_pad_cell_count; /** Total number of sent CELL_PADDING cells on padding-enabled cons */ uint64_t enabled_write_pad_cell_count; /** Total number of RELAY_DROP cells we have received */ uint64_t read_drop_cell_count; /** Total number of RELAY_DROP cells we have sent */ uint64_t write_drop_cell_count; /** The maximum number of padding timers we've seen in 24 hours */ uint64_t maximum_chanpad_timers; /** When did we first copy padding_current into padding_published? */ char first_published_at[ISO_TIME_LEN+1]; } padding_counts_t; /** Holds the current values of our padding statistics. * It is not published until it is transferred to padding_published. */ static padding_counts_t padding_current; /** Remains fixed for a 24 hour period, and then is replaced * by a redacted copy of padding_current */ static padding_counts_t padding_published; /** When did we last multiply all routers' weighted_run_length and * total_run_weights by STABILITY_ALPHA? */ static time_t stability_last_downrated = 0; /** */ static time_t started_tracking_stability = 0; /** Map from hex OR identity digest to or_history_t. */ static digestmap_t *history_map = NULL; /** Return the or_history_t for the OR with identity digest id, * creating it if necessary. */ static or_history_t * get_or_history(const char* id) { or_history_t *hist; if (tor_digest_is_zero(id)) return NULL; hist = digestmap_get(history_map, id); if (!hist) { hist = tor_malloc_zero(sizeof(or_history_t)); rephist_total_alloc += sizeof(or_history_t); rephist_total_num++; hist->since = hist->changed = time(NULL); tor_addr_make_unspec(&hist->last_reached_addr); digestmap_set(history_map, id, hist); } return hist; } /** Helper: free storage held by a single OR history entry. */ static void free_or_history(void *_hist) { or_history_t *hist = _hist; rephist_total_alloc -= sizeof(or_history_t); rephist_total_num--; tor_free(hist); } /** Initialize the static data structures for tracking history. */ void rep_hist_init(void) { history_map = digestmap_new(); bw_arrays_init(); predicted_ports_alloc(); } /** We have just decided that this router with identity digest id is * reachable, meaning we will give it a "Running" flag for the next while. */ void rep_hist_note_router_reachable(const char *id, const tor_addr_t *at_addr, const uint16_t at_port, time_t when) { or_history_t *hist = get_or_history(id); int was_in_run = 1; char tbuf[ISO_TIME_LEN+1]; int addr_changed, port_changed; tor_assert(hist); tor_assert((!at_addr && !at_port) || (at_addr && at_port)); addr_changed = at_addr && !tor_addr_is_null(&hist->last_reached_addr) && tor_addr_compare(at_addr, &hist->last_reached_addr, CMP_EXACT) != 0; port_changed = at_port && hist->last_reached_port && at_port != hist->last_reached_port; if (!started_tracking_stability) started_tracking_stability = time(NULL); if (!hist->start_of_run) { hist->start_of_run = when; was_in_run = 0; } if (hist->start_of_downtime) { long down_length; format_local_iso_time(tbuf, hist->start_of_downtime); log_info(LD_HIST, "Router %s is now Running; it had been down since %s.", hex_str(id, DIGEST_LEN), tbuf); if (was_in_run) log_info(LD_HIST, " (Paradoxically, it was already Running too.)"); down_length = when - hist->start_of_downtime; hist->total_weighted_time += down_length; hist->start_of_downtime = 0; } else if (addr_changed || port_changed) { /* If we're reachable, but the address changed, treat this as some * downtime. */ int penalty = get_options()->TestingTorNetwork ? 240 : 3600; networkstatus_t *ns; if ((ns = networkstatus_get_latest_consensus())) { int fresh_interval = (int)(ns->fresh_until - ns->valid_after); int live_interval = (int)(ns->valid_until - ns->valid_after); /* on average, a descriptor addr change takes .5 intervals to make it * into a consensus, and half a liveness period to make it to * clients. */ penalty = (int)(fresh_interval + live_interval) / 2; } format_local_iso_time(tbuf, hist->start_of_run); log_info(LD_HIST,"Router %s still seems Running, but its address appears " "to have changed since the last time it was reachable. I'm " "going to treat it as having been down for %d seconds", hex_str(id, DIGEST_LEN), penalty); rep_hist_note_router_unreachable(id, when-penalty); rep_hist_note_router_reachable(id, NULL, 0, when); } else { format_local_iso_time(tbuf, hist->start_of_run); if (was_in_run) log_debug(LD_HIST, "Router %s is still Running; it has been Running " "since %s", hex_str(id, DIGEST_LEN), tbuf); else log_info(LD_HIST,"Router %s is now Running; it was previously untracked", hex_str(id, DIGEST_LEN)); } if (at_addr) tor_addr_copy(&hist->last_reached_addr, at_addr); if (at_port) hist->last_reached_port = at_port; } /** We have just decided that this router is unreachable, meaning * we are taking away its "Running" flag. */ void rep_hist_note_router_unreachable(const char *id, time_t when) { or_history_t *hist = get_or_history(id); char tbuf[ISO_TIME_LEN+1]; int was_running = 0; if (!started_tracking_stability) started_tracking_stability = time(NULL); tor_assert(hist); if (hist->start_of_run) { /*XXXX We could treat failed connections differently from failed * connect attempts. */ long run_length = when - hist->start_of_run; format_local_iso_time(tbuf, hist->start_of_run); hist->total_run_weights += 1.0; hist->start_of_run = 0; if (run_length < 0) { unsigned long penalty = -run_length; #define SUBTRACT_CLAMPED(var, penalty) \ do { (var) = (var) < (penalty) ? 0 : (var) - (penalty); } while (0) SUBTRACT_CLAMPED(hist->weighted_run_length, penalty); SUBTRACT_CLAMPED(hist->weighted_uptime, penalty); } else { hist->weighted_run_length += run_length; hist->weighted_uptime += run_length; hist->total_weighted_time += run_length; } was_running = 1; log_info(LD_HIST, "Router %s is now non-Running: it had previously been " "Running since %s. Its total weighted uptime is %lu/%lu.", hex_str(id, DIGEST_LEN), tbuf, hist->weighted_uptime, hist->total_weighted_time); } if (!hist->start_of_downtime) { hist->start_of_downtime = when; if (!was_running) log_info(LD_HIST, "Router %s is now non-Running; it was previously " "untracked.", hex_str(id, DIGEST_LEN)); } else { if (!was_running) { format_local_iso_time(tbuf, hist->start_of_downtime); log_info(LD_HIST, "Router %s is still non-Running; it has been " "non-Running since %s.", hex_str(id, DIGEST_LEN), tbuf); } } } /** Mark a router with ID id as non-Running, and retroactively declare * that it has never been running: give it no stability and no WFU. */ void rep_hist_make_router_pessimal(const char *id, time_t when) { or_history_t *hist = get_or_history(id); tor_assert(hist); rep_hist_note_router_unreachable(id, when); hist->weighted_run_length = 0; hist->weighted_uptime = 0; } /** Helper: Discount all old MTBF data, if it is time to do so. Return * the time at which we should next discount MTBF data. */ time_t rep_hist_downrate_old_runs(time_t now) { digestmap_iter_t *orhist_it; const char *digest1; or_history_t *hist; void *hist_p; double alpha = 1.0; if (!history_map) history_map = digestmap_new(); if (!stability_last_downrated) stability_last_downrated = now; if (stability_last_downrated + STABILITY_INTERVAL > now) return stability_last_downrated + STABILITY_INTERVAL; /* Okay, we should downrate the data. By how much? */ while (stability_last_downrated + STABILITY_INTERVAL < now) { stability_last_downrated += STABILITY_INTERVAL; alpha *= STABILITY_ALPHA; } log_info(LD_HIST, "Discounting all old stability info by a factor of %f", alpha); /* Multiply every w_r_l, t_r_w pair by alpha. */ for (orhist_it = digestmap_iter_init(history_map); !digestmap_iter_done(orhist_it); orhist_it = digestmap_iter_next(history_map,orhist_it)) { digestmap_iter_get(orhist_it, &digest1, &hist_p); hist = hist_p; hist->weighted_run_length = (unsigned long)(hist->weighted_run_length * alpha); hist->total_run_weights *= alpha; hist->weighted_uptime = (unsigned long)(hist->weighted_uptime * alpha); hist->total_weighted_time = (unsigned long) (hist->total_weighted_time * alpha); } return stability_last_downrated + STABILITY_INTERVAL; } /** Helper: Return the weighted MTBF of the router with history hist. */ static double get_stability(or_history_t *hist, time_t when) { long total = hist->weighted_run_length; double total_weights = hist->total_run_weights; if (hist->start_of_run) { /* We're currently in a run. Let total and total_weights hold the values * they would hold if the current run were to end now. */ total += (when-hist->start_of_run); total_weights += 1.0; } if (total_weights < STABILITY_EPSILON) { /* Round down to zero, and avoid divide-by-zero. */ return 0.0; } return total / total_weights; } /** Return the total amount of time we've been observing, with each run of * time downrated by the appropriate factor. */ static long get_total_weighted_time(or_history_t *hist, time_t when) { long total = hist->total_weighted_time; if (hist->start_of_run) { total += (when - hist->start_of_run); } else if (hist->start_of_downtime) { total += (when - hist->start_of_downtime); } return total; } /** Helper: Return the weighted percent-of-time-online of the router with * history hist. */ static double get_weighted_fractional_uptime(or_history_t *hist, time_t when) { long total = hist->total_weighted_time; long up = hist->weighted_uptime; if (hist->start_of_run) { long run_length = (when - hist->start_of_run); up += run_length; total += run_length; } else if (hist->start_of_downtime) { total += (when - hist->start_of_downtime); } if (!total) { /* Avoid calling anybody's uptime infinity (which should be impossible if * the code is working), or NaN (which can happen for any router we haven't * observed up or down yet). */ return 0.0; } return ((double) up) / total; } /** Return how long the router whose identity digest is id has * been reachable. Return 0 if the router is unknown or currently deemed * unreachable. */ long rep_hist_get_uptime(const char *id, time_t when) { or_history_t *hist = get_or_history(id); if (!hist) return 0; if (!hist->start_of_run || when < hist->start_of_run) return 0; return when - hist->start_of_run; } /** Return an estimated MTBF for the router whose identity digest is * id. Return 0 if the router is unknown. */ double rep_hist_get_stability(const char *id, time_t when) { or_history_t *hist = get_or_history(id); if (!hist) return 0.0; return get_stability(hist, when); } /** Return an estimated percent-of-time-online for the router whose identity * digest is id. Return 0 if the router is unknown. */ double rep_hist_get_weighted_fractional_uptime(const char *id, time_t when) { or_history_t *hist = get_or_history(id); if (!hist) return 0.0; return get_weighted_fractional_uptime(hist, when); } /** Return a number representing how long we've known about the router whose * digest is id. Return 0 if the router is unknown. * * Be careful: this measure increases monotonically as we know the router for * longer and longer, but it doesn't increase linearly. */ long rep_hist_get_weighted_time_known(const char *id, time_t when) { or_history_t *hist = get_or_history(id); if (!hist) return 0; return get_total_weighted_time(hist, when); } /** Return true if we've been measuring MTBFs for long enough to * pronounce on Stability. */ int rep_hist_have_measured_enough_stability(void) { /* XXXX++ This doesn't do so well when we change our opinion * as to whether we're tracking router stability. */ return started_tracking_stability < time(NULL) - 4*60*60; } /** Log all the reliability data we have remembered, with the chosen * severity. */ void rep_hist_dump_stats(time_t now, int severity) { digestmap_iter_t *orhist_it; const char *name1, *digest1; char hexdigest1[HEX_DIGEST_LEN+1]; or_history_t *or_history; void *or_history_p; const node_t *node; rep_history_clean(now - get_options()->RephistTrackTime); tor_log(severity, LD_HIST, "--------------- Dumping history information:"); for (orhist_it = digestmap_iter_init(history_map); !digestmap_iter_done(orhist_it); orhist_it = digestmap_iter_next(history_map,orhist_it)) { double s; long stability; digestmap_iter_get(orhist_it, &digest1, &or_history_p); or_history = (or_history_t*) or_history_p; if ((node = node_get_by_id(digest1)) && node_get_nickname(node)) name1 = node_get_nickname(node); else name1 = "(unknown)"; base16_encode(hexdigest1, sizeof(hexdigest1), digest1, DIGEST_LEN); s = get_stability(or_history, now); stability = (long)s; tor_log(severity, LD_HIST, "OR %s [%s]: wmtbf %lu:%02lu:%02lu", name1, hexdigest1, stability/3600, (stability/60)%60, stability%60); } } /** Remove history info for routers/links that haven't changed since * before. */ void rep_history_clean(time_t before) { int authority = authdir_mode(get_options()); or_history_t *or_history; void *or_history_p; digestmap_iter_t *orhist_it; const char *d1; orhist_it = digestmap_iter_init(history_map); while (!digestmap_iter_done(orhist_it)) { int should_remove; digestmap_iter_get(orhist_it, &d1, &or_history_p); or_history = or_history_p; should_remove = authority ? (or_history->total_run_weights < STABILITY_EPSILON && !or_history->start_of_run) : (or_history->changed < before); if (should_remove) { orhist_it = digestmap_iter_next_rmv(history_map, orhist_it); free_or_history(or_history); continue; } orhist_it = digestmap_iter_next(history_map, orhist_it); } } /** Write MTBF data to disk. Return 0 on success, negative on failure. * * If missing_means_down, then if we're about to write an entry * that is still considered up but isn't in our routerlist, consider it * to be down. */ int rep_hist_record_mtbf_data(time_t now, int missing_means_down) { char time_buf[ISO_TIME_LEN+1]; digestmap_iter_t *orhist_it; const char *digest; void *or_history_p; or_history_t *hist; open_file_t *open_file = NULL; FILE *f; { char *filename = get_datadir_fname("router-stability"); f = start_writing_to_stdio_file(filename, OPEN_FLAGS_REPLACE|O_TEXT, 0600, &open_file); tor_free(filename); if (!f) return -1; } /* File format is: * FormatLine *KeywordLine Data * * FormatLine = "format 1" NL * KeywordLine = Keyword SP Arguments NL * Data = "data" NL *RouterMTBFLine "." NL * RouterMTBFLine = Fingerprint SP WeightedRunLen SP * TotalRunWeights [SP S=StartRunTime] NL */ #define PUT(s) STMT_BEGIN if (fputs((s),f)<0) goto err; STMT_END #define PRINTF(args) STMT_BEGIN if (fprintf args <0) goto err; STMT_END PUT("format 2\n"); format_iso_time(time_buf, time(NULL)); PRINTF((f, "stored-at %s\n", time_buf)); if (started_tracking_stability) { format_iso_time(time_buf, started_tracking_stability); PRINTF((f, "tracked-since %s\n", time_buf)); } if (stability_last_downrated) { format_iso_time(time_buf, stability_last_downrated); PRINTF((f, "last-downrated %s\n", time_buf)); } PUT("data\n"); /* XXX Nick: now bridge auths record this for all routers too. * Should we make them record it only for bridge routers? -RD * Not for 0.2.0. -NM */ for (orhist_it = digestmap_iter_init(history_map); !digestmap_iter_done(orhist_it); orhist_it = digestmap_iter_next(history_map,orhist_it)) { char dbuf[HEX_DIGEST_LEN+1]; const char *t = NULL; digestmap_iter_get(orhist_it, &digest, &or_history_p); hist = (or_history_t*) or_history_p; base16_encode(dbuf, sizeof(dbuf), digest, DIGEST_LEN); if (missing_means_down && hist->start_of_run && !connection_or_digest_is_known_relay(digest)) { /* We think this relay is running, but it's not listed in our * consensus. Somehow it fell out without telling us it went * down. Complain and also correct it. */ log_info(LD_HIST, "Relay '%s' is listed as up in rephist, but it's not in " "our routerlist. Correcting.", dbuf); rep_hist_note_router_unreachable(digest, now); } PRINTF((f, "R %s\n", dbuf)); if (hist->start_of_run > 0) { format_iso_time(time_buf, hist->start_of_run); t = time_buf; } PRINTF((f, "+MTBF %lu %.5f%s%s\n", hist->weighted_run_length, hist->total_run_weights, t ? " S=" : "", t ? t : "")); t = NULL; if (hist->start_of_downtime > 0) { format_iso_time(time_buf, hist->start_of_downtime); t = time_buf; } PRINTF((f, "+WFU %lu %lu%s%s\n", hist->weighted_uptime, hist->total_weighted_time, t ? " S=" : "", t ? t : "")); } PUT(".\n"); #undef PUT #undef PRINTF return finish_writing_to_file(open_file); err: abort_writing_to_file(open_file); return -1; } /** Helper: return the first j >= i such that !strcmpstart(sl[j], prefix) and * such that no line sl[k] with i <= k < j starts with "R ". Return -1 if no * such line exists. */ static int find_next_with(smartlist_t *sl, int i, const char *prefix) { for ( ; i < smartlist_len(sl); ++i) { const char *line = smartlist_get(sl, i); if (!strcmpstart(line, prefix)) return i; if (!strcmpstart(line, "R ")) return -1; } return -1; } /** How many bad times has parse_possibly_bad_iso_time() parsed? */ static int n_bogus_times = 0; /** Parse the ISO-formatted time in s into *time_out, but * round any pre-1970 date to Jan 1, 1970. */ static int parse_possibly_bad_iso_time(const char *s, time_t *time_out) { int year; char b[5]; strlcpy(b, s, sizeof(b)); b[4] = '\0'; year = (int)tor_parse_long(b, 10, 0, INT_MAX, NULL, NULL); if (year < 1970) { *time_out = 0; ++n_bogus_times; return 0; } else return parse_iso_time(s, time_out); } /** We've read a time t from a file stored at stored_at, which * says we started measuring at started_measuring. Return a new number * that's about as much before now as t was before * stored_at. */ static inline time_t correct_time(time_t t, time_t now, time_t stored_at, time_t started_measuring) { if (t < started_measuring - 24*60*60*365) return 0; else if (t < started_measuring) return started_measuring; else if (t > stored_at) return 0; else { long run_length = stored_at - t; t = (time_t)(now - run_length); if (t < started_measuring) t = started_measuring; return t; } } /** Load MTBF data from disk. Returns 0 on success or recoverable error, -1 * on failure. */ int rep_hist_load_mtbf_data(time_t now) { /* XXXX won't handle being called while history is already populated. */ smartlist_t *lines; const char *line = NULL; int r=0, i; time_t last_downrated = 0, stored_at = 0, tracked_since = 0; time_t latest_possible_start = now; long format = -1; { char *filename = get_datadir_fname("router-stability"); char *d = read_file_to_str(filename, RFTS_IGNORE_MISSING, NULL); tor_free(filename); if (!d) return -1; lines = smartlist_new(); smartlist_split_string(lines, d, "\n", SPLIT_SKIP_SPACE, 0); tor_free(d); } { const char *firstline; if (smartlist_len(lines)>4) { firstline = smartlist_get(lines, 0); if (!strcmpstart(firstline, "format ")) format = tor_parse_long(firstline+strlen("format "), 10, -1, LONG_MAX, NULL, NULL); } } if (format != 1 && format != 2) { log_warn(LD_HIST, "Unrecognized format in mtbf history file. Skipping."); goto err; } for (i = 1; i < smartlist_len(lines); ++i) { line = smartlist_get(lines, i); if (!strcmp(line, "data")) break; if (!strcmpstart(line, "last-downrated ")) { if (parse_iso_time(line+strlen("last-downrated "), &last_downrated)<0) log_warn(LD_HIST,"Couldn't parse downrate time in mtbf " "history file."); } if (!strcmpstart(line, "stored-at ")) { if (parse_iso_time(line+strlen("stored-at "), &stored_at)<0) log_warn(LD_HIST,"Couldn't parse stored time in mtbf " "history file."); } if (!strcmpstart(line, "tracked-since ")) { if (parse_iso_time(line+strlen("tracked-since "), &tracked_since)<0) log_warn(LD_HIST,"Couldn't parse started-tracking time in mtbf " "history file."); } } if (last_downrated > now) last_downrated = now; if (tracked_since > now) tracked_since = now; if (!stored_at) { log_warn(LD_HIST, "No stored time recorded."); goto err; } if (line && !strcmp(line, "data")) ++i; n_bogus_times = 0; for (; i < smartlist_len(lines); ++i) { char digest[DIGEST_LEN]; char hexbuf[HEX_DIGEST_LEN+1]; char mtbf_timebuf[ISO_TIME_LEN+1]; char wfu_timebuf[ISO_TIME_LEN+1]; time_t start_of_run = 0; time_t start_of_downtime = 0; int have_mtbf = 0, have_wfu = 0; long wrl = 0; double trw = 0; long wt_uptime = 0, total_wt_time = 0; int n; or_history_t *hist; line = smartlist_get(lines, i); if (!strcmp(line, ".")) break; mtbf_timebuf[0] = '\0'; wfu_timebuf[0] = '\0'; if (format == 1) { n = tor_sscanf(line, "%40s %ld %lf S=%10s %8s", hexbuf, &wrl, &trw, mtbf_timebuf, mtbf_timebuf+11); if (n != 3 && n != 5) { log_warn(LD_HIST, "Couldn't scan line %s", escaped(line)); continue; } have_mtbf = 1; } else { // format == 2. int mtbf_idx, wfu_idx; if (strcmpstart(line, "R ") || strlen(line) < 2+HEX_DIGEST_LEN) continue; strlcpy(hexbuf, line+2, sizeof(hexbuf)); mtbf_idx = find_next_with(lines, i+1, "+MTBF "); wfu_idx = find_next_with(lines, i+1, "+WFU "); if (mtbf_idx >= 0) { const char *mtbfline = smartlist_get(lines, mtbf_idx); n = tor_sscanf(mtbfline, "+MTBF %lu %lf S=%10s %8s", &wrl, &trw, mtbf_timebuf, mtbf_timebuf+11); if (n == 2 || n == 4) { have_mtbf = 1; } else { log_warn(LD_HIST, "Couldn't scan +MTBF line %s", escaped(mtbfline)); } } if (wfu_idx >= 0) { const char *wfuline = smartlist_get(lines, wfu_idx); n = tor_sscanf(wfuline, "+WFU %lu %lu S=%10s %8s", &wt_uptime, &total_wt_time, wfu_timebuf, wfu_timebuf+11); if (n == 2 || n == 4) { have_wfu = 1; } else { log_warn(LD_HIST, "Couldn't scan +WFU line %s", escaped(wfuline)); } } if (wfu_idx > i) i = wfu_idx; if (mtbf_idx > i) i = mtbf_idx; } if (base16_decode(digest, DIGEST_LEN, hexbuf, HEX_DIGEST_LEN) != DIGEST_LEN) { log_warn(LD_HIST, "Couldn't hex string %s", escaped(hexbuf)); continue; } hist = get_or_history(digest); if (!hist) continue; if (have_mtbf) { if (mtbf_timebuf[0]) { mtbf_timebuf[10] = ' '; if (parse_possibly_bad_iso_time(mtbf_timebuf, &start_of_run)<0) log_warn(LD_HIST, "Couldn't parse time %s", escaped(mtbf_timebuf)); } hist->start_of_run = correct_time(start_of_run, now, stored_at, tracked_since); if (hist->start_of_run < latest_possible_start + wrl) latest_possible_start = (time_t)(hist->start_of_run - wrl); hist->weighted_run_length = wrl; hist->total_run_weights = trw; } if (have_wfu) { if (wfu_timebuf[0]) { wfu_timebuf[10] = ' '; if (parse_possibly_bad_iso_time(wfu_timebuf, &start_of_downtime)<0) log_warn(LD_HIST, "Couldn't parse time %s", escaped(wfu_timebuf)); } } hist->start_of_downtime = correct_time(start_of_downtime, now, stored_at, tracked_since); hist->weighted_uptime = wt_uptime; hist->total_weighted_time = total_wt_time; } if (strcmp(line, ".")) log_warn(LD_HIST, "Truncated MTBF file."); if (tracked_since < 86400*365) /* Recover from insanely early value. */ tracked_since = latest_possible_start; stability_last_downrated = last_downrated; started_tracking_stability = tracked_since; goto done; err: r = -1; done: SMARTLIST_FOREACH(lines, char *, cp, tor_free(cp)); smartlist_free(lines); return r; } /** For how many seconds do we keep track of individual per-second bandwidth * totals? */ #define NUM_SECS_ROLLING_MEASURE 10 /** How large are the intervals for which we track and report bandwidth use? */ #define NUM_SECS_BW_SUM_INTERVAL (24*60*60) /** How far in the past do we remember and publish bandwidth use? */ #define NUM_SECS_BW_SUM_IS_VALID (5*24*60*60) /** How many bandwidth usage intervals do we remember? (derived) */ #define NUM_TOTALS (NUM_SECS_BW_SUM_IS_VALID/NUM_SECS_BW_SUM_INTERVAL) /** Structure to track bandwidth use, and remember the maxima for a given * time period. */ typedef struct bw_array_t { /** Observation array: Total number of bytes transferred in each of the last * NUM_SECS_ROLLING_MEASURE seconds. This is used as a circular array. */ uint64_t obs[NUM_SECS_ROLLING_MEASURE]; int cur_obs_idx; /**< Current position in obs. */ time_t cur_obs_time; /**< Time represented in obs[cur_obs_idx] */ uint64_t total_obs; /**< Total for all members of obs except * obs[cur_obs_idx] */ uint64_t max_total; /**< Largest value that total_obs has taken on in the * current period. */ uint64_t total_in_period; /**< Total bytes transferred in the current * period. */ /** When does the next period begin? */ time_t next_period; /** Where in 'maxima' should the maximum bandwidth usage for the current * period be stored? */ int next_max_idx; /** How many values in maxima/totals have been set ever? */ int num_maxes_set; /** Circular array of the maximum * bandwidth-per-NUM_SECS_ROLLING_MEASURE usage for the last * NUM_TOTALS periods */ uint64_t maxima[NUM_TOTALS]; /** Circular array of the total bandwidth usage for the last NUM_TOTALS * periods */ uint64_t totals[NUM_TOTALS]; } bw_array_t; /** Shift the current period of b forward by one. */ static void commit_max(bw_array_t *b) { /* Store total from current period. */ b->totals[b->next_max_idx] = b->total_in_period; /* Store maximum from current period. */ b->maxima[b->next_max_idx++] = b->max_total; /* Advance next_period and next_max_idx */ b->next_period += NUM_SECS_BW_SUM_INTERVAL; if (b->next_max_idx == NUM_TOTALS) b->next_max_idx = 0; if (b->num_maxes_set < NUM_TOTALS) ++b->num_maxes_set; /* Reset max_total. */ b->max_total = 0; /* Reset total_in_period. */ b->total_in_period = 0; } /** Shift the current observation time of b forward by one second. */ static inline void advance_obs(bw_array_t *b) { int nextidx; uint64_t total; /* Calculate the total bandwidth for the last NUM_SECS_ROLLING_MEASURE * seconds; adjust max_total as needed.*/ total = b->total_obs + b->obs[b->cur_obs_idx]; if (total > b->max_total) b->max_total = total; nextidx = b->cur_obs_idx+1; if (nextidx == NUM_SECS_ROLLING_MEASURE) nextidx = 0; b->total_obs = total - b->obs[nextidx]; b->obs[nextidx]=0; b->cur_obs_idx = nextidx; if (++b->cur_obs_time >= b->next_period) commit_max(b); } /** Add n bytes to the number of bytes in b for second * when. */ static inline void add_obs(bw_array_t *b, time_t when, uint64_t n) { if (when < b->cur_obs_time) return; /* Don't record data in the past. */ /* If we're currently adding observations for an earlier second than * 'when', advance b->cur_obs_time and b->cur_obs_idx by an * appropriate number of seconds, and do all the other housekeeping. */ while (when > b->cur_obs_time) { /* Doing this one second at a time is potentially inefficient, if we start with a state file that is very old. Fortunately, it doesn't seem to show up in profiles, so we can just ignore it for now. */ advance_obs(b); } b->obs[b->cur_obs_idx] += n; b->total_in_period += n; } /** Allocate, initialize, and return a new bw_array. */ static bw_array_t * bw_array_new(void) { bw_array_t *b; time_t start; b = tor_malloc_zero(sizeof(bw_array_t)); rephist_total_alloc += sizeof(bw_array_t); start = time(NULL); b->cur_obs_time = start; b->next_period = start + NUM_SECS_BW_SUM_INTERVAL; return b; } #define bw_array_free(val) \ FREE_AND_NULL(bw_array_t, bw_array_free_, (val)) /** Free storage held by bandwidth array b. */ static void bw_array_free_(bw_array_t *b) { if (!b) { return; } rephist_total_alloc -= sizeof(bw_array_t); tor_free(b); } /** Recent history of bandwidth observations for read operations. */ static bw_array_t *read_array = NULL; /** Recent history of bandwidth observations for write operations. */ static bw_array_t *write_array = NULL; /** Recent history of bandwidth observations for read operations for the directory protocol. */ static bw_array_t *dir_read_array = NULL; /** Recent history of bandwidth observations for write operations for the directory protocol. */ static bw_array_t *dir_write_array = NULL; /** Set up [dir-]read_array and [dir-]write_array, freeing them if they * already exist. */ static void bw_arrays_init(void) { bw_array_free(read_array); bw_array_free(write_array); bw_array_free(dir_read_array); bw_array_free(dir_write_array); read_array = bw_array_new(); write_array = bw_array_new(); dir_read_array = bw_array_new(); dir_write_array = bw_array_new(); } /** Remember that we read num_bytes bytes in second when. * * Add num_bytes to the current running total for when. * * when can go back to time, but it's safe to ignore calls * earlier than the latest when you've heard of. */ void rep_hist_note_bytes_written(size_t num_bytes, time_t when) { /* Maybe a circular array for recent seconds, and step to a new point * every time a new second shows up. Or simpler is to just to have * a normal array and push down each item every second; it's short. */ /* When a new second has rolled over, compute the sum of the bytes we've * seen over when-1 to when-1-NUM_SECS_ROLLING_MEASURE, and stick it * somewhere. See rep_hist_bandwidth_assess() below. */ add_obs(write_array, when, num_bytes); } /** Remember that we wrote num_bytes bytes in second when. * (like rep_hist_note_bytes_written() above) */ void rep_hist_note_bytes_read(size_t num_bytes, time_t when) { /* if we're smart, we can make this func and the one above share code */ add_obs(read_array, when, num_bytes); } /** Remember that we wrote num_bytes directory bytes in second * when. (like rep_hist_note_bytes_written() above) */ void rep_hist_note_dir_bytes_written(size_t num_bytes, time_t when) { add_obs(dir_write_array, when, num_bytes); } /** Remember that we read num_bytes directory bytes in second * when. (like rep_hist_note_bytes_written() above) */ void rep_hist_note_dir_bytes_read(size_t num_bytes, time_t when) { add_obs(dir_read_array, when, num_bytes); } /** Helper: Return the largest value in b->maxima. (This is equal to the * most bandwidth used in any NUM_SECS_ROLLING_MEASURE period for the last * NUM_SECS_BW_SUM_IS_VALID seconds.) */ static uint64_t find_largest_max(bw_array_t *b) { int i; uint64_t max; max=0; for (i=0; imaxima[i]>max) max = b->maxima[i]; } return max; } /** Find the largest sums in the past NUM_SECS_BW_SUM_IS_VALID (roughly) * seconds. Find one sum for reading and one for writing. They don't have * to be at the same time. * * Return the smaller of these sums, divided by NUM_SECS_ROLLING_MEASURE. */ int rep_hist_bandwidth_assess(void) { uint64_t w,r; r = find_largest_max(read_array); w = find_largest_max(write_array); if (r>w) return (int)(U64_TO_DBL(w)/NUM_SECS_ROLLING_MEASURE); else return (int)(U64_TO_DBL(r)/NUM_SECS_ROLLING_MEASURE); } /** Print the bandwidth history of b (either [dir-]read_array or * [dir-]write_array) into the buffer pointed to by buf. The format is * simply comma separated numbers, from oldest to newest. * * It returns the number of bytes written. */ static size_t rep_hist_fill_bandwidth_history(char *buf, size_t len, const bw_array_t *b) { char *cp = buf; int i, n; const or_options_t *options = get_options(); uint64_t cutoff; if (b->num_maxes_set <= b->next_max_idx) { /* We haven't been through the circular array yet; time starts at i=0.*/ i = 0; } else { /* We've been around the array at least once. The next i to be overwritten is the oldest. */ i = b->next_max_idx; } if (options->RelayBandwidthRate) { /* We don't want to report that we used more bandwidth than the max we're * willing to relay; otherwise everybody will know how much traffic * we used ourself. */ cutoff = options->RelayBandwidthRate * NUM_SECS_BW_SUM_INTERVAL; } else { cutoff = UINT64_MAX; } for (n=0; nnum_maxes_set; ++n,++i) { uint64_t total; if (i >= NUM_TOTALS) i -= NUM_TOTALS; tor_assert(i < NUM_TOTALS); /* Round the bandwidth used down to the nearest 1k. */ total = b->totals[i] & ~0x3ff; if (total > cutoff) total = cutoff; if (n==(b->num_maxes_set-1)) tor_snprintf(cp, len-(cp-buf), U64_FORMAT, U64_PRINTF_ARG(total)); else tor_snprintf(cp, len-(cp-buf), U64_FORMAT",", U64_PRINTF_ARG(total)); cp += strlen(cp); } return cp-buf; } /** Allocate and return lines for representing this server's bandwidth * history in its descriptor. We publish these lines in our extra-info * descriptor. */ char * rep_hist_get_bandwidth_lines(void) { char *buf, *cp; char t[ISO_TIME_LEN+1]; int r; bw_array_t *b = NULL; const char *desc = NULL; size_t len; /* [dirreq-](read|write)-history yyyy-mm-dd HH:MM:SS (n s) n,n,n... */ /* The n,n,n part above. Largest representation of a uint64_t is 20 chars * long, plus the comma. */ #define MAX_HIST_VALUE_LEN (21*NUM_TOTALS) len = (67+MAX_HIST_VALUE_LEN)*4; buf = tor_malloc_zero(len); cp = buf; for (r=0;r<4;++r) { char tmp[MAX_HIST_VALUE_LEN]; size_t slen; switch (r) { case 0: b = write_array; desc = "write-history"; break; case 1: b = read_array; desc = "read-history"; break; case 2: b = dir_write_array; desc = "dirreq-write-history"; break; case 3: b = dir_read_array; desc = "dirreq-read-history"; break; } tor_assert(b); slen = rep_hist_fill_bandwidth_history(tmp, MAX_HIST_VALUE_LEN, b); /* If we don't have anything to write, skip to the next entry. */ if (slen == 0) continue; format_iso_time(t, b->next_period-NUM_SECS_BW_SUM_INTERVAL); tor_snprintf(cp, len-(cp-buf), "%s %s (%d s) ", desc, t, NUM_SECS_BW_SUM_INTERVAL); cp += strlen(cp); strlcat(cp, tmp, len-(cp-buf)); cp += slen; strlcat(cp, "\n", len-(cp-buf)); ++cp; } return buf; } /** Write a single bw_array_t into the Values, Ends, Interval, and Maximum * entries of an or_state_t. Done before writing out a new state file. */ static void rep_hist_update_bwhist_state_section(or_state_t *state, const bw_array_t *b, smartlist_t **s_values, smartlist_t **s_maxima, time_t *s_begins, int *s_interval) { int i,j; uint64_t maxval; if (*s_values) { SMARTLIST_FOREACH(*s_values, char *, val, tor_free(val)); smartlist_free(*s_values); } if (*s_maxima) { SMARTLIST_FOREACH(*s_maxima, char *, val, tor_free(val)); smartlist_free(*s_maxima); } if (! server_mode(get_options())) { /* Clients don't need to store bandwidth history persistently; * force these values to the defaults. */ /* FFFF we should pull the default out of config.c's state table, * so we don't have two defaults. */ if (*s_begins != 0 || *s_interval != 900) { time_t now = time(NULL); time_t save_at = get_options()->AvoidDiskWrites ? now+3600 : now+600; or_state_mark_dirty(state, save_at); } *s_begins = 0; *s_interval = 900; *s_values = smartlist_new(); *s_maxima = smartlist_new(); return; } *s_begins = b->next_period; *s_interval = NUM_SECS_BW_SUM_INTERVAL; *s_values = smartlist_new(); *s_maxima = smartlist_new(); /* Set i to first position in circular array */ i = (b->num_maxes_set <= b->next_max_idx) ? 0 : b->next_max_idx; for (j=0; j < b->num_maxes_set; ++j,++i) { if (i >= NUM_TOTALS) i = 0; smartlist_add_asprintf(*s_values, U64_FORMAT, U64_PRINTF_ARG(b->totals[i] & ~0x3ff)); maxval = b->maxima[i] / NUM_SECS_ROLLING_MEASURE; smartlist_add_asprintf(*s_maxima, U64_FORMAT, U64_PRINTF_ARG(maxval & ~0x3ff)); } smartlist_add_asprintf(*s_values, U64_FORMAT, U64_PRINTF_ARG(b->total_in_period & ~0x3ff)); maxval = b->max_total / NUM_SECS_ROLLING_MEASURE; smartlist_add_asprintf(*s_maxima, U64_FORMAT, U64_PRINTF_ARG(maxval & ~0x3ff)); } /** Update state with the newest bandwidth history. Done before * writing out a new state file. */ void rep_hist_update_state(or_state_t *state) { #define UPDATE(arrname,st) \ rep_hist_update_bwhist_state_section(state,\ (arrname),\ &state->BWHistory ## st ## Values, \ &state->BWHistory ## st ## Maxima, \ &state->BWHistory ## st ## Ends, \ &state->BWHistory ## st ## Interval) UPDATE(write_array, Write); UPDATE(read_array, Read); UPDATE(dir_write_array, DirWrite); UPDATE(dir_read_array, DirRead); if (server_mode(get_options())) { or_state_mark_dirty(state, time(NULL)+(2*3600)); } #undef UPDATE } /** Load a single bw_array_t from its Values, Ends, Maxima, and Interval * entries in an or_state_t. Done while reading the state file. */ static int rep_hist_load_bwhist_state_section(bw_array_t *b, const smartlist_t *s_values, const smartlist_t *s_maxima, const time_t s_begins, const int s_interval) { time_t now = time(NULL); int retval = 0; time_t start; uint64_t v, mv; int i,ok,ok_m = 0; int have_maxima = s_maxima && s_values && (smartlist_len(s_values) == smartlist_len(s_maxima)); if (s_values && s_begins >= now - NUM_SECS_BW_SUM_INTERVAL*NUM_TOTALS) { start = s_begins - s_interval*(smartlist_len(s_values)); if (start > now) return 0; b->cur_obs_time = start; b->next_period = start + NUM_SECS_BW_SUM_INTERVAL; SMARTLIST_FOREACH_BEGIN(s_values, const char *, cp) { const char *maxstr = NULL; v = tor_parse_uint64(cp, 10, 0, UINT64_MAX, &ok, NULL); if (have_maxima) { maxstr = smartlist_get(s_maxima, cp_sl_idx); mv = tor_parse_uint64(maxstr, 10, 0, UINT64_MAX, &ok_m, NULL); mv *= NUM_SECS_ROLLING_MEASURE; } else { /* No maxima known; guess average rate to be conservative. */ mv = (v / s_interval) * NUM_SECS_ROLLING_MEASURE; } if (!ok) { retval = -1; log_notice(LD_HIST, "Could not parse value '%s' into a number.'",cp); } if (maxstr && !ok_m) { retval = -1; log_notice(LD_HIST, "Could not parse maximum '%s' into a number.'", maxstr); } if (start < now) { time_t cur_start = start; time_t actual_interval_len = s_interval; uint64_t cur_val = 0; /* Calculate the average per second. This is the best we can do * because our state file doesn't have per-second resolution. */ if (start + s_interval > now) actual_interval_len = now - start; cur_val = v / actual_interval_len; /* This is potentially inefficient, but since we don't do it very * often it should be ok. */ while (cur_start < start + actual_interval_len) { add_obs(b, cur_start, cur_val); ++cur_start; } b->max_total = mv; /* This will result in some fairly choppy history if s_interval * is not the same as NUM_SECS_BW_SUM_INTERVAL. XXXX */ start += actual_interval_len; } } SMARTLIST_FOREACH_END(cp); } /* Clean up maxima and observed */ for (i=0; iobs[i] = 0; } b->total_obs = 0; return retval; } /** Set bandwidth history from the state file we just loaded. */ int rep_hist_load_state(or_state_t *state, char **err) { int all_ok = 1; /* Assert they already have been malloced */ tor_assert(read_array && write_array); tor_assert(dir_read_array && dir_write_array); #define LOAD(arrname,st) \ if (rep_hist_load_bwhist_state_section( \ (arrname), \ state->BWHistory ## st ## Values, \ state->BWHistory ## st ## Maxima, \ state->BWHistory ## st ## Ends, \ state->BWHistory ## st ## Interval)<0) \ all_ok = 0 LOAD(write_array, Write); LOAD(read_array, Read); LOAD(dir_write_array, DirWrite); LOAD(dir_read_array, DirRead); #undef LOAD if (!all_ok) { *err = tor_strdup("Parsing of bandwidth history values failed"); /* and create fresh arrays */ bw_arrays_init(); return -1; } return 0; } /*********************************************************************/ /** A single predicted port: used to remember which ports we've made * connections to, so that we can try to keep making circuits that can handle * those ports. */ typedef struct predicted_port_t { /** The port we connected to */ uint16_t port; /** The time at which we last used it */ time_t time; } predicted_port_t; /** A list of port numbers that have been used recently. */ static smartlist_t *predicted_ports_list=NULL; /** How long do we keep predicting circuits? */ static int prediction_timeout=0; /** When was the last time we added a prediction entry (HS or port) */ static time_t last_prediction_add_time=0; /** * How much time left until we stop predicting circuits? */ int predicted_ports_prediction_time_remaining(time_t now) { time_t idle_delta; /* Protect against overflow of return value. This can happen if the clock * jumps backwards in time. Update the last prediction time (aka last * active time) to prevent it. This update is preferable to using monotonic * time because it prevents clock jumps into the past from simply causing * very long idle timeouts while the monotonic time stands still. */ if (last_prediction_add_time > now) { last_prediction_add_time = now; idle_delta = 0; } else { idle_delta = now - last_prediction_add_time; } /* Protect against underflow of the return value. This can happen for very * large periods of inactivity/system sleep. */ if (idle_delta > prediction_timeout) return 0; if (BUG((prediction_timeout - idle_delta) > INT_MAX)) { return INT_MAX; } return (int)(prediction_timeout - idle_delta); } /** We just got an application request for a connection with * port port. Remember it for the future, so we can keep * some circuits open that will exit to this port. */ static void add_predicted_port(time_t now, uint16_t port) { predicted_port_t *pp = tor_malloc(sizeof(predicted_port_t)); // If the list is empty, re-randomize predicted ports lifetime if (!any_predicted_circuits(now)) { prediction_timeout = channelpadding_get_circuits_available_timeout(); } last_prediction_add_time = now; log_info(LD_CIRC, "New port prediction added. Will continue predictive circ building " "for %d more seconds.", predicted_ports_prediction_time_remaining(now)); pp->port = port; pp->time = now; rephist_total_alloc += sizeof(*pp); smartlist_add(predicted_ports_list, pp); } /** * Allocate whatever memory and structs are needed for predicting * which ports will be used. Also seed it with port 80, so we'll build * circuits on start-up. */ static void predicted_ports_alloc(void) { predicted_ports_list = smartlist_new(); } void predicted_ports_init(void) { add_predicted_port(time(NULL), 443); // Add a port to get us started } /** Free whatever memory is needed for predicting which ports will * be used. */ static void predicted_ports_free_all(void) { rephist_total_alloc -= smartlist_len(predicted_ports_list)*sizeof(predicted_port_t); SMARTLIST_FOREACH(predicted_ports_list, predicted_port_t *, pp, tor_free(pp)); smartlist_free(predicted_ports_list); } /** Remember that port has been asked for as of time now. * This is used for predicting what sorts of streams we'll make in the * future and making exit circuits to anticipate that. */ void rep_hist_note_used_port(time_t now, uint16_t port) { tor_assert(predicted_ports_list); if (!port) /* record nothing */ return; SMARTLIST_FOREACH_BEGIN(predicted_ports_list, predicted_port_t *, pp) { if (pp->port == port) { pp->time = now; last_prediction_add_time = now; log_info(LD_CIRC, "New port prediction added. Will continue predictive circ " "building for %d more seconds.", predicted_ports_prediction_time_remaining(now)); return; } } SMARTLIST_FOREACH_END(pp); /* it's not there yet; we need to add it */ add_predicted_port(now, port); } /** Return a newly allocated pointer to a list of uint16_t * for ports that * are likely to be asked for in the near future. */ smartlist_t * rep_hist_get_predicted_ports(time_t now) { int predicted_circs_relevance_time; smartlist_t *out = smartlist_new(); tor_assert(predicted_ports_list); predicted_circs_relevance_time = prediction_timeout; /* clean out obsolete entries */ SMARTLIST_FOREACH_BEGIN(predicted_ports_list, predicted_port_t *, pp) { if (pp->time + predicted_circs_relevance_time < now) { log_debug(LD_CIRC, "Expiring predicted port %d", pp->port); rephist_total_alloc -= sizeof(predicted_port_t); tor_free(pp); SMARTLIST_DEL_CURRENT(predicted_ports_list, pp); } else { smartlist_add(out, tor_memdup(&pp->port, sizeof(uint16_t))); } } SMARTLIST_FOREACH_END(pp); return out; } /** * Take a list of uint16_t *, and remove every port in the list from the * current list of predicted ports. */ void rep_hist_remove_predicted_ports(const smartlist_t *rmv_ports) { /* Let's do this on O(N), not O(N^2). */ bitarray_t *remove_ports = bitarray_init_zero(UINT16_MAX); SMARTLIST_FOREACH(rmv_ports, const uint16_t *, p, bitarray_set(remove_ports, *p)); SMARTLIST_FOREACH_BEGIN(predicted_ports_list, predicted_port_t *, pp) { if (bitarray_is_set(remove_ports, pp->port)) { tor_free(pp); rephist_total_alloc -= sizeof(*pp); SMARTLIST_DEL_CURRENT(predicted_ports_list, pp); } } SMARTLIST_FOREACH_END(pp); bitarray_free(remove_ports); } /** The user asked us to do a resolve. Rather than keeping track of * timings and such of resolves, we fake it for now by treating * it the same way as a connection to port 80. This way we will continue * to have circuits lying around if the user only uses Tor for resolves. */ void rep_hist_note_used_resolve(time_t now) { rep_hist_note_used_port(now, 80); } /** The last time at which we needed an internal circ. */ static time_t predicted_internal_time = 0; /** The last time we needed an internal circ with good uptime. */ static time_t predicted_internal_uptime_time = 0; /** The last time we needed an internal circ with good capacity. */ static time_t predicted_internal_capacity_time = 0; /** Remember that we used an internal circ at time now. */ void rep_hist_note_used_internal(time_t now, int need_uptime, int need_capacity) { // If the list is empty, re-randomize predicted ports lifetime if (!any_predicted_circuits(now)) { prediction_timeout = channelpadding_get_circuits_available_timeout(); } last_prediction_add_time = now; log_info(LD_CIRC, "New port prediction added. Will continue predictive circ building " "for %d more seconds.", predicted_ports_prediction_time_remaining(now)); predicted_internal_time = now; if (need_uptime) predicted_internal_uptime_time = now; if (need_capacity) predicted_internal_capacity_time = now; } /** Return 1 if we've used an internal circ recently; else return 0. */ int rep_hist_get_predicted_internal(time_t now, int *need_uptime, int *need_capacity) { int predicted_circs_relevance_time; predicted_circs_relevance_time = prediction_timeout; if (!predicted_internal_time) { /* initialize it */ predicted_internal_time = now; predicted_internal_uptime_time = now; predicted_internal_capacity_time = now; } if (predicted_internal_time + predicted_circs_relevance_time < now) return 0; /* too long ago */ if (predicted_internal_uptime_time + predicted_circs_relevance_time >= now) *need_uptime = 1; // Always predict that we need capacity. *need_capacity = 1; return 1; } /** Any ports used lately? These are pre-seeded if we just started * up or if we're running a hidden service. */ int any_predicted_circuits(time_t now) { int predicted_circs_relevance_time; predicted_circs_relevance_time = prediction_timeout; return smartlist_len(predicted_ports_list) || predicted_internal_time + predicted_circs_relevance_time >= now; } /** Return 1 if we have no need for circuits currently, else return 0. */ int rep_hist_circbuilding_dormant(time_t now) { const or_options_t *options = get_options(); if (any_predicted_circuits(now)) return 0; /* see if we'll still need to build testing circuits */ if (server_mode(options) && (!check_whether_orport_reachable(options) || !circuit_enough_testing_circs())) return 0; if (!check_whether_dirport_reachable(options)) return 0; return 1; } /*** Exit port statistics ***/ /* Some constants */ /** To what multiple should byte numbers be rounded up? */ #define EXIT_STATS_ROUND_UP_BYTES 1024 /** To what multiple should stream counts be rounded up? */ #define EXIT_STATS_ROUND_UP_STREAMS 4 /** Number of TCP ports */ #define EXIT_STATS_NUM_PORTS 65536 /** Top n ports that will be included in exit stats. */ #define EXIT_STATS_TOP_N_PORTS 10 /* The following data structures are arrays and no fancy smartlists or maps, * so that all write operations can be done in constant time. This comes at * the price of some memory (1.25 MB) and linear complexity when writing * stats for measuring relays. */ /** Number of bytes read in current period by exit port */ static uint64_t *exit_bytes_read = NULL; /** Number of bytes written in current period by exit port */ static uint64_t *exit_bytes_written = NULL; /** Number of streams opened in current period by exit port */ static uint32_t *exit_streams = NULL; /** Start time of exit stats or 0 if we're not collecting exit stats. */ static time_t start_of_exit_stats_interval; /** Initialize exit port stats. */ void rep_hist_exit_stats_init(time_t now) { start_of_exit_stats_interval = now; exit_bytes_read = tor_calloc(EXIT_STATS_NUM_PORTS, sizeof(uint64_t)); exit_bytes_written = tor_calloc(EXIT_STATS_NUM_PORTS, sizeof(uint64_t)); exit_streams = tor_calloc(EXIT_STATS_NUM_PORTS, sizeof(uint32_t)); } /** Reset counters for exit port statistics. */ void rep_hist_reset_exit_stats(time_t now) { start_of_exit_stats_interval = now; memset(exit_bytes_read, 0, EXIT_STATS_NUM_PORTS * sizeof(uint64_t)); memset(exit_bytes_written, 0, EXIT_STATS_NUM_PORTS * sizeof(uint64_t)); memset(exit_streams, 0, EXIT_STATS_NUM_PORTS * sizeof(uint32_t)); } /** Stop collecting exit port stats in a way that we can re-start doing * so in rep_hist_exit_stats_init(). */ void rep_hist_exit_stats_term(void) { start_of_exit_stats_interval = 0; tor_free(exit_bytes_read); tor_free(exit_bytes_written); tor_free(exit_streams); } /** Helper for qsort: compare two ints. Does not handle overflow properly, * but works fine for sorting an array of port numbers, which is what we use * it for. */ static int compare_int_(const void *x, const void *y) { return (*(int*)x - *(int*)y); } /** Return a newly allocated string containing the exit port statistics * until now, or NULL if we're not collecting exit stats. Caller * must ensure start_of_exit_stats_interval is in the past. */ char * rep_hist_format_exit_stats(time_t now) { int i, j, top_elements = 0, cur_min_idx = 0, cur_port; uint64_t top_bytes[EXIT_STATS_TOP_N_PORTS]; int top_ports[EXIT_STATS_TOP_N_PORTS]; uint64_t cur_bytes = 0, other_read = 0, other_written = 0, total_read = 0, total_written = 0; uint32_t total_streams = 0, other_streams = 0; smartlist_t *written_strings, *read_strings, *streams_strings; char *written_string, *read_string, *streams_string; char t[ISO_TIME_LEN+1]; char *result; if (!start_of_exit_stats_interval) return NULL; /* Not initialized. */ tor_assert(now >= start_of_exit_stats_interval); /* Go through all ports to find the n ports that saw most written and * read bytes. * * Invariant: at the end of the loop for iteration i, * total_read is the sum of all exit_bytes_read[0..i] * total_written is the sum of all exit_bytes_written[0..i] * total_stream is the sum of all exit_streams[0..i] * * top_elements = MAX(EXIT_STATS_TOP_N_PORTS, * #{j | 0 <= j <= i && volume(i) > 0}) * * For all 0 <= j < top_elements, * top_bytes[j] > 0 * 0 <= top_ports[j] <= 65535 * top_bytes[j] = volume(top_ports[j]) * * There is no j in 0..i and k in 0..top_elements such that: * volume(j) > top_bytes[k] AND j is not in top_ports[0..top_elements] * * There is no j!=cur_min_idx in 0..top_elements such that: * top_bytes[j] < top_bytes[cur_min_idx] * * where volume(x) == exit_bytes_read[x]+exit_bytes_written[x] * * Worst case: O(EXIT_STATS_NUM_PORTS * EXIT_STATS_TOP_N_PORTS) */ for (i = 1; i < EXIT_STATS_NUM_PORTS; i++) { total_read += exit_bytes_read[i]; total_written += exit_bytes_written[i]; total_streams += exit_streams[i]; cur_bytes = exit_bytes_read[i] + exit_bytes_written[i]; if (cur_bytes == 0) { continue; } if (top_elements < EXIT_STATS_TOP_N_PORTS) { top_bytes[top_elements] = cur_bytes; top_ports[top_elements++] = i; } else if (cur_bytes > top_bytes[cur_min_idx]) { top_bytes[cur_min_idx] = cur_bytes; top_ports[cur_min_idx] = i; } else { continue; } cur_min_idx = 0; for (j = 1; j < top_elements; j++) { if (top_bytes[j] < top_bytes[cur_min_idx]) { cur_min_idx = j; } } } /* Add observations of top ports to smartlists. */ written_strings = smartlist_new(); read_strings = smartlist_new(); streams_strings = smartlist_new(); other_read = total_read; other_written = total_written; other_streams = total_streams; /* Sort the ports; this puts them out of sync with top_bytes, but we * won't be using top_bytes again anyway */ qsort(top_ports, top_elements, sizeof(int), compare_int_); for (j = 0; j < top_elements; j++) { cur_port = top_ports[j]; if (exit_bytes_written[cur_port] > 0) { uint64_t num = round_uint64_to_next_multiple_of( exit_bytes_written[cur_port], EXIT_STATS_ROUND_UP_BYTES); num /= 1024; smartlist_add_asprintf(written_strings, "%d="U64_FORMAT, cur_port, U64_PRINTF_ARG(num)); other_written -= exit_bytes_written[cur_port]; } if (exit_bytes_read[cur_port] > 0) { uint64_t num = round_uint64_to_next_multiple_of( exit_bytes_read[cur_port], EXIT_STATS_ROUND_UP_BYTES); num /= 1024; smartlist_add_asprintf(read_strings, "%d="U64_FORMAT, cur_port, U64_PRINTF_ARG(num)); other_read -= exit_bytes_read[cur_port]; } if (exit_streams[cur_port] > 0) { uint32_t num = round_uint32_to_next_multiple_of( exit_streams[cur_port], EXIT_STATS_ROUND_UP_STREAMS); smartlist_add_asprintf(streams_strings, "%d=%u", cur_port, num); other_streams -= exit_streams[cur_port]; } } /* Add observations of other ports in a single element. */ other_written = round_uint64_to_next_multiple_of(other_written, EXIT_STATS_ROUND_UP_BYTES); other_written /= 1024; smartlist_add_asprintf(written_strings, "other="U64_FORMAT, U64_PRINTF_ARG(other_written)); other_read = round_uint64_to_next_multiple_of(other_read, EXIT_STATS_ROUND_UP_BYTES); other_read /= 1024; smartlist_add_asprintf(read_strings, "other="U64_FORMAT, U64_PRINTF_ARG(other_read)); other_streams = round_uint32_to_next_multiple_of(other_streams, EXIT_STATS_ROUND_UP_STREAMS); smartlist_add_asprintf(streams_strings, "other=%u", other_streams); /* Join all observations in single strings. */ written_string = smartlist_join_strings(written_strings, ",", 0, NULL); read_string = smartlist_join_strings(read_strings, ",", 0, NULL); streams_string = smartlist_join_strings(streams_strings, ",", 0, NULL); SMARTLIST_FOREACH(written_strings, char *, cp, tor_free(cp)); SMARTLIST_FOREACH(read_strings, char *, cp, tor_free(cp)); SMARTLIST_FOREACH(streams_strings, char *, cp, tor_free(cp)); smartlist_free(written_strings); smartlist_free(read_strings); smartlist_free(streams_strings); /* Put everything together. */ format_iso_time(t, now); tor_asprintf(&result, "exit-stats-end %s (%d s)\n" "exit-kibibytes-written %s\n" "exit-kibibytes-read %s\n" "exit-streams-opened %s\n", t, (unsigned) (now - start_of_exit_stats_interval), written_string, read_string, streams_string); tor_free(written_string); tor_free(read_string); tor_free(streams_string); return result; } /** If 24 hours have passed since the beginning of the current exit port * stats period, write exit stats to $DATADIR/stats/exit-stats (possibly * overwriting an existing file) and reset counters. Return when we would * next want to write exit stats or 0 if we never want to write. */ time_t rep_hist_exit_stats_write(time_t now) { char *str = NULL; if (!start_of_exit_stats_interval) return 0; /* Not initialized. */ if (start_of_exit_stats_interval + WRITE_STATS_INTERVAL > now) goto done; /* Not ready to write. */ log_info(LD_HIST, "Writing exit port statistics to disk."); /* Generate history string. */ str = rep_hist_format_exit_stats(now); /* Reset counters. */ rep_hist_reset_exit_stats(now); /* Try to write to disk. */ if (!check_or_create_data_subdir("stats")) { write_to_data_subdir("stats", "exit-stats", str, "exit port statistics"); } done: tor_free(str); return start_of_exit_stats_interval + WRITE_STATS_INTERVAL; } /** Note that we wrote num_written bytes and read num_read * bytes to/from an exit connection to port. */ void rep_hist_note_exit_bytes(uint16_t port, size_t num_written, size_t num_read) { if (!start_of_exit_stats_interval) return; /* Not initialized. */ exit_bytes_written[port] += num_written; exit_bytes_read[port] += num_read; log_debug(LD_HIST, "Written %lu bytes and read %lu bytes to/from an " "exit connection to port %d.", (unsigned long)num_written, (unsigned long)num_read, port); } /** Note that we opened an exit stream to port. */ void rep_hist_note_exit_stream_opened(uint16_t port) { if (!start_of_exit_stats_interval) return; /* Not initialized. */ exit_streams[port]++; log_debug(LD_HIST, "Opened exit stream to port %d", port); } /*** cell statistics ***/ /** Start of the current buffer stats interval or 0 if we're not * collecting buffer statistics. */ static time_t start_of_buffer_stats_interval; /** Initialize buffer stats. */ void rep_hist_buffer_stats_init(time_t now) { start_of_buffer_stats_interval = now; } /** Statistics from a single circuit. Collected when the circuit closes, or * when we flush statistics to disk. */ typedef struct circ_buffer_stats_t { /** Average number of cells in the circuit's queue */ double mean_num_cells_in_queue; /** Average time a cell waits in the queue. */ double mean_time_cells_in_queue; /** Total number of cells sent over this circuit */ uint32_t processed_cells; } circ_buffer_stats_t; /** List of circ_buffer_stats_t. */ static smartlist_t *circuits_for_buffer_stats = NULL; /** Remember cell statistics mean_num_cells_in_queue, * mean_time_cells_in_queue, and processed_cells of a * circuit. */ void rep_hist_add_buffer_stats(double mean_num_cells_in_queue, double mean_time_cells_in_queue, uint32_t processed_cells) { circ_buffer_stats_t *stats; if (!start_of_buffer_stats_interval) return; /* Not initialized. */ stats = tor_malloc_zero(sizeof(circ_buffer_stats_t)); stats->mean_num_cells_in_queue = mean_num_cells_in_queue; stats->mean_time_cells_in_queue = mean_time_cells_in_queue; stats->processed_cells = processed_cells; if (!circuits_for_buffer_stats) circuits_for_buffer_stats = smartlist_new(); smartlist_add(circuits_for_buffer_stats, stats); } /** Remember cell statistics for circuit circ at time * end_of_interval and reset cell counters in case the circuit * remains open in the next measurement interval. */ void rep_hist_buffer_stats_add_circ(circuit_t *circ, time_t end_of_interval) { time_t start_of_interval; int interval_length; or_circuit_t *orcirc; double mean_num_cells_in_queue, mean_time_cells_in_queue; uint32_t processed_cells; if (CIRCUIT_IS_ORIGIN(circ)) return; orcirc = TO_OR_CIRCUIT(circ); if (!orcirc->processed_cells) return; start_of_interval = (circ->timestamp_created.tv_sec > start_of_buffer_stats_interval) ? (time_t)circ->timestamp_created.tv_sec : start_of_buffer_stats_interval; interval_length = (int) (end_of_interval - start_of_interval); if (interval_length <= 0) return; processed_cells = orcirc->processed_cells; /* 1000.0 for s -> ms; 2.0 because of app-ward and exit-ward queues */ mean_num_cells_in_queue = (double) orcirc->total_cell_waiting_time / (double) interval_length / 1000.0 / 2.0; mean_time_cells_in_queue = (double) orcirc->total_cell_waiting_time / (double) orcirc->processed_cells; orcirc->total_cell_waiting_time = 0; orcirc->processed_cells = 0; rep_hist_add_buffer_stats(mean_num_cells_in_queue, mean_time_cells_in_queue, processed_cells); } /** Sorting helper: return -1, 1, or 0 based on comparison of two * circ_buffer_stats_t */ static int buffer_stats_compare_entries_(const void **_a, const void **_b) { const circ_buffer_stats_t *a = *_a, *b = *_b; if (a->processed_cells < b->processed_cells) return 1; else if (a->processed_cells > b->processed_cells) return -1; else return 0; } /** Stop collecting cell stats in a way that we can re-start doing so in * rep_hist_buffer_stats_init(). */ void rep_hist_buffer_stats_term(void) { rep_hist_reset_buffer_stats(0); } /** Clear history of circuit statistics and set the measurement interval * start to now. */ void rep_hist_reset_buffer_stats(time_t now) { if (!circuits_for_buffer_stats) circuits_for_buffer_stats = smartlist_new(); SMARTLIST_FOREACH(circuits_for_buffer_stats, circ_buffer_stats_t *, stats, tor_free(stats)); smartlist_clear(circuits_for_buffer_stats); start_of_buffer_stats_interval = now; } /** Return a newly allocated string containing the buffer statistics until * now, or NULL if we're not collecting buffer stats. Caller must * ensure start_of_buffer_stats_interval is in the past. */ char * rep_hist_format_buffer_stats(time_t now) { #define SHARES 10 uint64_t processed_cells[SHARES]; uint32_t circs_in_share[SHARES]; int number_of_circuits, i; double queued_cells[SHARES], time_in_queue[SHARES]; smartlist_t *processed_cells_strings, *queued_cells_strings, *time_in_queue_strings; char *processed_cells_string, *queued_cells_string, *time_in_queue_string; char t[ISO_TIME_LEN+1]; char *result; if (!start_of_buffer_stats_interval) return NULL; /* Not initialized. */ tor_assert(now >= start_of_buffer_stats_interval); /* Calculate deciles if we saw at least one circuit. */ memset(processed_cells, 0, SHARES * sizeof(uint64_t)); memset(circs_in_share, 0, SHARES * sizeof(uint32_t)); memset(queued_cells, 0, SHARES * sizeof(double)); memset(time_in_queue, 0, SHARES * sizeof(double)); if (!circuits_for_buffer_stats) circuits_for_buffer_stats = smartlist_new(); number_of_circuits = smartlist_len(circuits_for_buffer_stats); if (number_of_circuits > 0) { smartlist_sort(circuits_for_buffer_stats, buffer_stats_compare_entries_); i = 0; SMARTLIST_FOREACH_BEGIN(circuits_for_buffer_stats, circ_buffer_stats_t *, stats) { int share = i++ * SHARES / number_of_circuits; processed_cells[share] += stats->processed_cells; queued_cells[share] += stats->mean_num_cells_in_queue; time_in_queue[share] += stats->mean_time_cells_in_queue; circs_in_share[share]++; } SMARTLIST_FOREACH_END(stats); } /* Write deciles to strings. */ processed_cells_strings = smartlist_new(); queued_cells_strings = smartlist_new(); time_in_queue_strings = smartlist_new(); for (i = 0; i < SHARES; i++) { smartlist_add_asprintf(processed_cells_strings, U64_FORMAT, !circs_in_share[i] ? 0 : U64_PRINTF_ARG(processed_cells[i] / circs_in_share[i])); } for (i = 0; i < SHARES; i++) { smartlist_add_asprintf(queued_cells_strings, "%.2f", circs_in_share[i] == 0 ? 0.0 : queued_cells[i] / (double) circs_in_share[i]); } for (i = 0; i < SHARES; i++) { smartlist_add_asprintf(time_in_queue_strings, "%.0f", circs_in_share[i] == 0 ? 0.0 : time_in_queue[i] / (double) circs_in_share[i]); } /* Join all observations in single strings. */ processed_cells_string = smartlist_join_strings(processed_cells_strings, ",", 0, NULL); queued_cells_string = smartlist_join_strings(queued_cells_strings, ",", 0, NULL); time_in_queue_string = smartlist_join_strings(time_in_queue_strings, ",", 0, NULL); SMARTLIST_FOREACH(processed_cells_strings, char *, cp, tor_free(cp)); SMARTLIST_FOREACH(queued_cells_strings, char *, cp, tor_free(cp)); SMARTLIST_FOREACH(time_in_queue_strings, char *, cp, tor_free(cp)); smartlist_free(processed_cells_strings); smartlist_free(queued_cells_strings); smartlist_free(time_in_queue_strings); /* Put everything together. */ format_iso_time(t, now); tor_asprintf(&result, "cell-stats-end %s (%d s)\n" "cell-processed-cells %s\n" "cell-queued-cells %s\n" "cell-time-in-queue %s\n" "cell-circuits-per-decile %d\n", t, (unsigned) (now - start_of_buffer_stats_interval), processed_cells_string, queued_cells_string, time_in_queue_string, CEIL_DIV(number_of_circuits, SHARES)); tor_free(processed_cells_string); tor_free(queued_cells_string); tor_free(time_in_queue_string); return result; #undef SHARES } /** If 24 hours have passed since the beginning of the current buffer * stats period, write buffer stats to $DATADIR/stats/buffer-stats * (possibly overwriting an existing file) and reset counters. Return * when we would next want to write buffer stats or 0 if we never want to * write. */ time_t rep_hist_buffer_stats_write(time_t now) { char *str = NULL; if (!start_of_buffer_stats_interval) return 0; /* Not initialized. */ if (start_of_buffer_stats_interval + WRITE_STATS_INTERVAL > now) goto done; /* Not ready to write */ /* Add open circuits to the history. */ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { rep_hist_buffer_stats_add_circ(circ, now); } SMARTLIST_FOREACH_END(circ); /* Generate history string. */ str = rep_hist_format_buffer_stats(now); /* Reset both buffer history and counters of open circuits. */ rep_hist_reset_buffer_stats(now); /* Try to write to disk. */ if (!check_or_create_data_subdir("stats")) { write_to_data_subdir("stats", "buffer-stats", str, "buffer statistics"); } done: tor_free(str); return start_of_buffer_stats_interval + WRITE_STATS_INTERVAL; } /*** Descriptor serving statistics ***/ /** Digestmap to track which descriptors were downloaded this stats * collection interval. It maps descriptor digest to pointers to 1, * effectively turning this into a list. */ static digestmap_t *served_descs = NULL; /** Number of how many descriptors were downloaded in total during this * interval. */ static unsigned long total_descriptor_downloads; /** Start time of served descs stats or 0 if we're not collecting those. */ static time_t start_of_served_descs_stats_interval; /** Initialize descriptor stats. */ void rep_hist_desc_stats_init(time_t now) { if (served_descs) { log_warn(LD_BUG, "Called rep_hist_desc_stats_init() when desc stats were " "already initialized. This is probably harmless."); return; // Already initialized } served_descs = digestmap_new(); total_descriptor_downloads = 0; start_of_served_descs_stats_interval = now; } /** Reset served descs stats to empty, starting a new interval now. */ static void rep_hist_reset_desc_stats(time_t now) { rep_hist_desc_stats_term(); rep_hist_desc_stats_init(now); } /** Stop collecting served descs stats, so that rep_hist_desc_stats_init() is * safe to be called again. */ void rep_hist_desc_stats_term(void) { digestmap_free(served_descs, NULL); served_descs = NULL; start_of_served_descs_stats_interval = 0; total_descriptor_downloads = 0; } /** Helper for rep_hist_desc_stats_write(). Return a newly allocated string * containing the served desc statistics until now, or NULL if we're not * collecting served desc stats. Caller must ensure that now is not before * start_of_served_descs_stats_interval. */ static char * rep_hist_format_desc_stats(time_t now) { char t[ISO_TIME_LEN+1]; char *result; digestmap_iter_t *iter; const char *key; void *val; unsigned size; int *vals, max = 0, q3 = 0, md = 0, q1 = 0, min = 0; int n = 0; if (!start_of_served_descs_stats_interval) return NULL; size = digestmap_size(served_descs); if (size > 0) { vals = tor_calloc(size, sizeof(int)); for (iter = digestmap_iter_init(served_descs); !digestmap_iter_done(iter); iter = digestmap_iter_next(served_descs, iter)) { uintptr_t count; digestmap_iter_get(iter, &key, &val); count = (uintptr_t)val; vals[n++] = (int)count; (void)key; } max = find_nth_int(vals, size, size-1); q3 = find_nth_int(vals, size, (3*size-1)/4); md = find_nth_int(vals, size, (size-1)/2); q1 = find_nth_int(vals, size, (size-1)/4); min = find_nth_int(vals, size, 0); tor_free(vals); } format_iso_time(t, now); tor_asprintf(&result, "served-descs-stats-end %s (%d s) total=%lu unique=%u " "max=%d q3=%d md=%d q1=%d min=%d\n", t, (unsigned) (now - start_of_served_descs_stats_interval), total_descriptor_downloads, size, max, q3, md, q1, min); return result; } /** If WRITE_STATS_INTERVAL seconds have passed since the beginning of * the current served desc stats interval, write the stats to * $DATADIR/stats/served-desc-stats (possibly appending to an existing file) * and reset the state for the next interval. Return when we would next want * to write served desc stats or 0 if we won't want to write. */ time_t rep_hist_desc_stats_write(time_t now) { char *filename = NULL, *str = NULL; if (!start_of_served_descs_stats_interval) return 0; /* We're not collecting stats. */ if (start_of_served_descs_stats_interval + WRITE_STATS_INTERVAL > now) return start_of_served_descs_stats_interval + WRITE_STATS_INTERVAL; str = rep_hist_format_desc_stats(now); tor_assert(str != NULL); if (check_or_create_data_subdir("stats") < 0) { goto done; } filename = get_datadir_fname2("stats", "served-desc-stats"); if (append_bytes_to_file(filename, str, strlen(str), 0) < 0) log_warn(LD_HIST, "Unable to write served descs statistics to disk!"); rep_hist_reset_desc_stats(now); done: tor_free(filename); tor_free(str); return start_of_served_descs_stats_interval + WRITE_STATS_INTERVAL; } /** Called to note that we've served a given descriptor (by * digest). Increments the count of descriptors served, and the number * of times we've served this descriptor. */ void rep_hist_note_desc_served(const char * desc) { void *val; uintptr_t count; if (!served_descs) return; // We're not collecting stats val = digestmap_get(served_descs, desc); count = (uintptr_t)val; if (count != INT_MAX) ++count; digestmap_set(served_descs, desc, (void*)count); total_descriptor_downloads++; } /*** Connection statistics ***/ /** Start of the current connection stats interval or 0 if we're not * collecting connection statistics. */ static time_t start_of_conn_stats_interval; /** Initialize connection stats. */ void rep_hist_conn_stats_init(time_t now) { start_of_conn_stats_interval = now; } /* Count connections that we read and wrote less than these many bytes * from/to as below threshold. */ #define BIDI_THRESHOLD 20480 /* Count connections that we read or wrote at least this factor as many * bytes from/to than we wrote or read to/from as mostly reading or * writing. */ #define BIDI_FACTOR 10 /* Interval length in seconds for considering read and written bytes for * connection stats. */ #define BIDI_INTERVAL 10 /** Start of next BIDI_INTERVAL second interval. */ static time_t bidi_next_interval = 0; /** Number of connections that we read and wrote less than BIDI_THRESHOLD * bytes from/to in BIDI_INTERVAL seconds. */ static uint32_t below_threshold = 0; /** Number of connections that we read at least BIDI_FACTOR times more * bytes from than we wrote to in BIDI_INTERVAL seconds. */ static uint32_t mostly_read = 0; /** Number of connections that we wrote at least BIDI_FACTOR times more * bytes to than we read from in BIDI_INTERVAL seconds. */ static uint32_t mostly_written = 0; /** Number of connections that we read and wrote at least BIDI_THRESHOLD * bytes from/to, but not BIDI_FACTOR times more in either direction in * BIDI_INTERVAL seconds. */ static uint32_t both_read_and_written = 0; /** Entry in a map from connection ID to the number of read and written * bytes on this connection in a BIDI_INTERVAL second interval. */ typedef struct bidi_map_entry_t { HT_ENTRY(bidi_map_entry_t) node; uint64_t conn_id; /**< Connection ID */ size_t read; /**< Number of read bytes */ size_t written; /**< Number of written bytes */ } bidi_map_entry_t; /** Map of OR connections together with the number of read and written * bytes in the current BIDI_INTERVAL second interval. */ static HT_HEAD(bidimap, bidi_map_entry_t) bidi_map = HT_INITIALIZER(); static int bidi_map_ent_eq(const bidi_map_entry_t *a, const bidi_map_entry_t *b) { return a->conn_id == b->conn_id; } /* DOCDOC bidi_map_ent_hash */ static unsigned bidi_map_ent_hash(const bidi_map_entry_t *entry) { return (unsigned) entry->conn_id; } HT_PROTOTYPE(bidimap, bidi_map_entry_t, node, bidi_map_ent_hash, bidi_map_ent_eq) HT_GENERATE2(bidimap, bidi_map_entry_t, node, bidi_map_ent_hash, bidi_map_ent_eq, 0.6, tor_reallocarray_, tor_free_) /* DOCDOC bidi_map_free */ static void bidi_map_free_all(void) { bidi_map_entry_t **ptr, **next, *ent; for (ptr = HT_START(bidimap, &bidi_map); ptr; ptr = next) { ent = *ptr; next = HT_NEXT_RMV(bidimap, &bidi_map, ptr); tor_free(ent); } HT_CLEAR(bidimap, &bidi_map); } /** Reset counters for conn statistics. */ void rep_hist_reset_conn_stats(time_t now) { start_of_conn_stats_interval = now; below_threshold = 0; mostly_read = 0; mostly_written = 0; both_read_and_written = 0; bidi_map_free_all(); } /** Stop collecting connection stats in a way that we can re-start doing * so in rep_hist_conn_stats_init(). */ void rep_hist_conn_stats_term(void) { rep_hist_reset_conn_stats(0); } /** We read num_read bytes and wrote num_written from/to OR * connection conn_id in second when. If this is the first * observation in a new interval, sum up the last observations. Add bytes * for this connection. */ void rep_hist_note_or_conn_bytes(uint64_t conn_id, size_t num_read, size_t num_written, time_t when) { if (!start_of_conn_stats_interval) return; /* Initialize */ if (bidi_next_interval == 0) bidi_next_interval = when + BIDI_INTERVAL; /* Sum up last period's statistics */ if (when >= bidi_next_interval) { bidi_map_entry_t **ptr, **next, *ent; for (ptr = HT_START(bidimap, &bidi_map); ptr; ptr = next) { ent = *ptr; if (ent->read + ent->written < BIDI_THRESHOLD) below_threshold++; else if (ent->read >= ent->written * BIDI_FACTOR) mostly_read++; else if (ent->written >= ent->read * BIDI_FACTOR) mostly_written++; else both_read_and_written++; next = HT_NEXT_RMV(bidimap, &bidi_map, ptr); tor_free(ent); } while (when >= bidi_next_interval) bidi_next_interval += BIDI_INTERVAL; log_info(LD_GENERAL, "%d below threshold, %d mostly read, " "%d mostly written, %d both read and written.", below_threshold, mostly_read, mostly_written, both_read_and_written); } /* Add this connection's bytes. */ if (num_read > 0 || num_written > 0) { bidi_map_entry_t *entry, lookup; lookup.conn_id = conn_id; entry = HT_FIND(bidimap, &bidi_map, &lookup); if (entry) { entry->written += num_written; entry->read += num_read; } else { entry = tor_malloc_zero(sizeof(bidi_map_entry_t)); entry->conn_id = conn_id; entry->written = num_written; entry->read = num_read; HT_INSERT(bidimap, &bidi_map, entry); } } } /** Return a newly allocated string containing the connection statistics * until now, or NULL if we're not collecting conn stats. Caller must * ensure start_of_conn_stats_interval is in the past. */ char * rep_hist_format_conn_stats(time_t now) { char *result, written[ISO_TIME_LEN+1]; if (!start_of_conn_stats_interval) return NULL; /* Not initialized. */ tor_assert(now >= start_of_conn_stats_interval); format_iso_time(written, now); tor_asprintf(&result, "conn-bi-direct %s (%d s) %d,%d,%d,%d\n", written, (unsigned) (now - start_of_conn_stats_interval), below_threshold, mostly_read, mostly_written, both_read_and_written); return result; } /** If 24 hours have passed since the beginning of the current conn stats * period, write conn stats to $DATADIR/stats/conn-stats (possibly * overwriting an existing file) and reset counters. Return when we would * next want to write conn stats or 0 if we never want to write. */ time_t rep_hist_conn_stats_write(time_t now) { char *str = NULL; if (!start_of_conn_stats_interval) return 0; /* Not initialized. */ if (start_of_conn_stats_interval + WRITE_STATS_INTERVAL > now) goto done; /* Not ready to write */ /* Generate history string. */ str = rep_hist_format_conn_stats(now); /* Reset counters. */ rep_hist_reset_conn_stats(now); /* Try to write to disk. */ if (!check_or_create_data_subdir("stats")) { write_to_data_subdir("stats", "conn-stats", str, "connection statistics"); } done: tor_free(str); return start_of_conn_stats_interval + WRITE_STATS_INTERVAL; } /** Internal statistics to track how many requests of each type of * handshake we've received, and how many we've assigned to cpuworkers. * Useful for seeing trends in cpu load. * @{ */ STATIC int onion_handshakes_requested[MAX_ONION_HANDSHAKE_TYPE+1] = {0}; STATIC int onion_handshakes_assigned[MAX_ONION_HANDSHAKE_TYPE+1] = {0}; /**@}*/ /** A new onionskin (using the type handshake) has arrived. */ void rep_hist_note_circuit_handshake_requested(uint16_t type) { if (type <= MAX_ONION_HANDSHAKE_TYPE) onion_handshakes_requested[type]++; } /** We've sent an onionskin (using the type handshake) to a * cpuworker. */ void rep_hist_note_circuit_handshake_assigned(uint16_t type) { if (type <= MAX_ONION_HANDSHAKE_TYPE) onion_handshakes_assigned[type]++; } /** Log our onionskin statistics since the last time we were called. */ void rep_hist_log_circuit_handshake_stats(time_t now) { (void)now; log_notice(LD_HEARTBEAT, "Circuit handshake stats since last time: " "%d/%d TAP, %d/%d NTor.", onion_handshakes_assigned[ONION_HANDSHAKE_TYPE_TAP], onion_handshakes_requested[ONION_HANDSHAKE_TYPE_TAP], onion_handshakes_assigned[ONION_HANDSHAKE_TYPE_NTOR], onion_handshakes_requested[ONION_HANDSHAKE_TYPE_NTOR]); memset(onion_handshakes_assigned, 0, sizeof(onion_handshakes_assigned)); memset(onion_handshakes_requested, 0, sizeof(onion_handshakes_requested)); } /* Hidden service statistics section */ /** Start of the current hidden service stats interval or 0 if we're * not collecting hidden service statistics. */ static time_t start_of_hs_stats_interval; /** Carries the various hidden service statistics, and any other * information needed. */ typedef struct hs_stats_t { /** How many relay cells have we seen as rendezvous points? */ uint64_t rp_relay_cells_seen; /** Set of unique public key digests we've seen this stat period * (could also be implemented as sorted smartlist). */ digestmap_t *onions_seen_this_period; } hs_stats_t; /** Our statistics structure singleton. */ static hs_stats_t *hs_stats = NULL; /** Allocate, initialize and return an hs_stats_t structure. */ static hs_stats_t * hs_stats_new(void) { hs_stats_t *new_hs_stats = tor_malloc_zero(sizeof(hs_stats_t)); new_hs_stats->onions_seen_this_period = digestmap_new(); return new_hs_stats; } #define hs_stats_free(val) \ FREE_AND_NULL(hs_stats_t, hs_stats_free_, (val)) /** Free an hs_stats_t structure. */ static void hs_stats_free_(hs_stats_t *victim_hs_stats) { if (!victim_hs_stats) { return; } digestmap_free(victim_hs_stats->onions_seen_this_period, NULL); tor_free(victim_hs_stats); } /** Initialize hidden service statistics. */ void rep_hist_hs_stats_init(time_t now) { if (!hs_stats) { hs_stats = hs_stats_new(); } start_of_hs_stats_interval = now; } /** Clear history of hidden service statistics and set the measurement * interval start to now. */ static void rep_hist_reset_hs_stats(time_t now) { if (!hs_stats) { hs_stats = hs_stats_new(); } hs_stats->rp_relay_cells_seen = 0; digestmap_free(hs_stats->onions_seen_this_period, NULL); hs_stats->onions_seen_this_period = digestmap_new(); start_of_hs_stats_interval = now; } /** Stop collecting hidden service stats in a way that we can re-start * doing so in rep_hist_buffer_stats_init(). */ void rep_hist_hs_stats_term(void) { rep_hist_reset_hs_stats(0); } /** We saw a new HS relay cell, Count it! */ void rep_hist_seen_new_rp_cell(void) { if (!hs_stats) { return; // We're not collecting stats } hs_stats->rp_relay_cells_seen++; } /** As HSDirs, we saw another hidden service with public key * pubkey. Check whether we have counted it before, if not * count it now! */ void rep_hist_stored_maybe_new_hs(const crypto_pk_t *pubkey) { char pubkey_hash[DIGEST_LEN]; if (!hs_stats) { return; // We're not collecting stats } /* Get the digest of the pubkey which will be used to detect whether we've seen this hidden service before or not. */ if (crypto_pk_get_digest(pubkey, pubkey_hash) < 0) { /* This fail should not happen; key has been validated by descriptor parsing code first. */ return; } /* Check if this is the first time we've seen this hidden service. If it is, count it as new. */ if (!digestmap_get(hs_stats->onions_seen_this_period, pubkey_hash)) { digestmap_set(hs_stats->onions_seen_this_period, pubkey_hash, (void*)(uintptr_t)1); } } /* The number of cells that are supposed to be hidden from the adversary * by adding noise from the Laplace distribution. This value, divided by * EPSILON, is Laplace parameter b. It must be greather than 0. */ #define REND_CELLS_DELTA_F 2048 /* Security parameter for obfuscating number of cells with a value between * ]0.0, 1.0]. Smaller values obfuscate observations more, but at the same * time make statistics less usable. */ #define REND_CELLS_EPSILON 0.3 /* The number of cells that are supposed to be hidden from the adversary * by rounding up to the next multiple of this number. */ #define REND_CELLS_BIN_SIZE 1024 /* The number of service identities that are supposed to be hidden from the * adversary by adding noise from the Laplace distribution. This value, * divided by EPSILON, is Laplace parameter b. It must be greater than 0. */ #define ONIONS_SEEN_DELTA_F 8 /* Security parameter for obfuscating number of service identities with a * value between ]0.0, 1.0]. Smaller values obfuscate observations more, but * at the same time make statistics less usable. */ #define ONIONS_SEEN_EPSILON 0.3 /* The number of service identities that are supposed to be hidden from * the adversary by rounding up to the next multiple of this number. */ #define ONIONS_SEEN_BIN_SIZE 8 /** Allocate and return a string containing hidden service stats that * are meant to be placed in the extra-info descriptor. */ static char * rep_hist_format_hs_stats(time_t now) { char t[ISO_TIME_LEN+1]; char *hs_stats_string; int64_t obfuscated_cells_seen; int64_t obfuscated_onions_seen; uint64_t rounded_cells_seen = round_uint64_to_next_multiple_of(hs_stats->rp_relay_cells_seen, REND_CELLS_BIN_SIZE); rounded_cells_seen = MIN(rounded_cells_seen, INT64_MAX); obfuscated_cells_seen = add_laplace_noise((int64_t)rounded_cells_seen, crypto_rand_double(), REND_CELLS_DELTA_F, REND_CELLS_EPSILON); uint64_t rounded_onions_seen = round_uint64_to_next_multiple_of((size_t)digestmap_size( hs_stats->onions_seen_this_period), ONIONS_SEEN_BIN_SIZE); rounded_onions_seen = MIN(rounded_onions_seen, INT64_MAX); obfuscated_onions_seen = add_laplace_noise((int64_t)rounded_onions_seen, crypto_rand_double(), ONIONS_SEEN_DELTA_F, ONIONS_SEEN_EPSILON); format_iso_time(t, now); tor_asprintf(&hs_stats_string, "hidserv-stats-end %s (%d s)\n" "hidserv-rend-relayed-cells "I64_FORMAT" delta_f=%d " "epsilon=%.2f bin_size=%d\n" "hidserv-dir-onions-seen "I64_FORMAT" delta_f=%d " "epsilon=%.2f bin_size=%d\n", t, (unsigned) (now - start_of_hs_stats_interval), I64_PRINTF_ARG(obfuscated_cells_seen), REND_CELLS_DELTA_F, REND_CELLS_EPSILON, REND_CELLS_BIN_SIZE, I64_PRINTF_ARG(obfuscated_onions_seen), ONIONS_SEEN_DELTA_F, ONIONS_SEEN_EPSILON, ONIONS_SEEN_BIN_SIZE); return hs_stats_string; } /** If 24 hours have passed since the beginning of the current HS * stats period, write buffer stats to $DATADIR/stats/hidserv-stats * (possibly overwriting an existing file) and reset counters. Return * when we would next want to write buffer stats or 0 if we never want to * write. */ time_t rep_hist_hs_stats_write(time_t now) { char *str = NULL; if (!start_of_hs_stats_interval) { return 0; /* Not initialized. */ } if (start_of_hs_stats_interval + WRITE_STATS_INTERVAL > now) { goto done; /* Not ready to write */ } /* Generate history string. */ str = rep_hist_format_hs_stats(now); /* Reset HS history. */ rep_hist_reset_hs_stats(now); /* Try to write to disk. */ if (!check_or_create_data_subdir("stats")) { write_to_data_subdir("stats", "hidserv-stats", str, "hidden service stats"); } done: tor_free(str); return start_of_hs_stats_interval + WRITE_STATS_INTERVAL; } static uint64_t link_proto_count[MAX_LINK_PROTO+1][2]; /** Note that we negotiated link protocol version link_proto, on * a connection that started here iff started_here is true. */ void rep_hist_note_negotiated_link_proto(unsigned link_proto, int started_here) { started_here = !!started_here; /* force to 0 or 1 */ if (link_proto > MAX_LINK_PROTO) { log_warn(LD_BUG, "Can't log link protocol %u", link_proto); return; } link_proto_count[link_proto][started_here]++; } /** * Update the maximum count of total pending channel padding timers * in this period. */ void rep_hist_padding_count_timers(uint64_t num_timers) { if (num_timers > padding_current.maximum_chanpad_timers) { padding_current.maximum_chanpad_timers = num_timers; } } /** * Count a cell that we sent for padding overhead statistics. * * RELAY_COMMAND_DROP and CELL_PADDING are accounted separately. Both should be * counted for PADDING_TYPE_TOTAL. */ void rep_hist_padding_count_write(padding_type_t type) { switch (type) { case PADDING_TYPE_DROP: padding_current.write_drop_cell_count++; break; case PADDING_TYPE_CELL: padding_current.write_pad_cell_count++; break; case PADDING_TYPE_TOTAL: padding_current.write_cell_count++; break; case PADDING_TYPE_ENABLED_TOTAL: padding_current.enabled_write_cell_count++; break; case PADDING_TYPE_ENABLED_CELL: padding_current.enabled_write_pad_cell_count++; break; } } /** * Count a cell that we've received for padding overhead statistics. * * RELAY_COMMAND_DROP and CELL_PADDING are accounted separately. Both should be * counted for PADDING_TYPE_TOTAL. */ void rep_hist_padding_count_read(padding_type_t type) { switch (type) { case PADDING_TYPE_DROP: padding_current.read_drop_cell_count++; break; case PADDING_TYPE_CELL: padding_current.read_pad_cell_count++; break; case PADDING_TYPE_TOTAL: padding_current.read_cell_count++; break; case PADDING_TYPE_ENABLED_TOTAL: padding_current.enabled_read_cell_count++; break; case PADDING_TYPE_ENABLED_CELL: padding_current.enabled_read_pad_cell_count++; break; } } /** * Reset our current padding statistics. Called once every 24 hours. */ void rep_hist_reset_padding_counts(void) { memset(&padding_current, 0, sizeof(padding_current)); } /** * Copy our current cell counts into a structure for listing in our * extra-info descriptor. Also perform appropriate rounding and redaction. * * This function is called once every 24 hours. */ #define MIN_CELL_COUNTS_TO_PUBLISH 1 #define ROUND_CELL_COUNTS_TO 10000 void rep_hist_prep_published_padding_counts(time_t now) { memcpy(&padding_published, &padding_current, sizeof(padding_published)); if (padding_published.read_cell_count < MIN_CELL_COUNTS_TO_PUBLISH || padding_published.write_cell_count < MIN_CELL_COUNTS_TO_PUBLISH) { memset(&padding_published, 0, sizeof(padding_published)); return; } format_iso_time(padding_published.first_published_at, now); #define ROUND_AND_SET_COUNT(x) (x) = round_uint64_to_next_multiple_of((x), \ ROUND_CELL_COUNTS_TO) ROUND_AND_SET_COUNT(padding_published.read_pad_cell_count); ROUND_AND_SET_COUNT(padding_published.write_pad_cell_count); ROUND_AND_SET_COUNT(padding_published.read_drop_cell_count); ROUND_AND_SET_COUNT(padding_published.write_drop_cell_count); ROUND_AND_SET_COUNT(padding_published.write_cell_count); ROUND_AND_SET_COUNT(padding_published.read_cell_count); ROUND_AND_SET_COUNT(padding_published.enabled_read_cell_count); ROUND_AND_SET_COUNT(padding_published.enabled_read_pad_cell_count); ROUND_AND_SET_COUNT(padding_published.enabled_write_cell_count); ROUND_AND_SET_COUNT(padding_published.enabled_write_pad_cell_count); #undef ROUND_AND_SET_COUNT } /** * Returns an allocated string for extra-info documents for publishing * padding statistics from the last 24 hour interval. */ char * rep_hist_get_padding_count_lines(void) { char *result = NULL; if (!padding_published.read_cell_count || !padding_published.write_cell_count) { return NULL; } tor_asprintf(&result, "padding-counts %s (%d s)" " bin-size="U64_FORMAT " write-drop="U64_FORMAT " write-pad="U64_FORMAT " write-total="U64_FORMAT " read-drop="U64_FORMAT " read-pad="U64_FORMAT " read-total="U64_FORMAT " enabled-read-pad="U64_FORMAT " enabled-read-total="U64_FORMAT " enabled-write-pad="U64_FORMAT " enabled-write-total="U64_FORMAT " max-chanpad-timers="U64_FORMAT "\n", padding_published.first_published_at, REPHIST_CELL_PADDING_COUNTS_INTERVAL, U64_PRINTF_ARG(ROUND_CELL_COUNTS_TO), U64_PRINTF_ARG(padding_published.write_drop_cell_count), U64_PRINTF_ARG(padding_published.write_pad_cell_count), U64_PRINTF_ARG(padding_published.write_cell_count), U64_PRINTF_ARG(padding_published.read_drop_cell_count), U64_PRINTF_ARG(padding_published.read_pad_cell_count), U64_PRINTF_ARG(padding_published.read_cell_count), U64_PRINTF_ARG(padding_published.enabled_read_pad_cell_count), U64_PRINTF_ARG(padding_published.enabled_read_cell_count), U64_PRINTF_ARG(padding_published.enabled_write_pad_cell_count), U64_PRINTF_ARG(padding_published.enabled_write_cell_count), U64_PRINTF_ARG(padding_published.maximum_chanpad_timers) ); return result; } /** Log a heartbeat message explaining how many connections of each link * protocol version we have used. */ void rep_hist_log_link_protocol_counts(void) { log_notice(LD_HEARTBEAT, "Since startup, we have initiated " U64_FORMAT" v1 connections, " U64_FORMAT" v2 connections, " U64_FORMAT" v3 connections, and " U64_FORMAT" v4 connections; and received " U64_FORMAT" v1 connections, " U64_FORMAT" v2 connections, " U64_FORMAT" v3 connections, and " U64_FORMAT" v4 connections.", U64_PRINTF_ARG(link_proto_count[1][1]), U64_PRINTF_ARG(link_proto_count[2][1]), U64_PRINTF_ARG(link_proto_count[3][1]), U64_PRINTF_ARG(link_proto_count[4][1]), U64_PRINTF_ARG(link_proto_count[1][0]), U64_PRINTF_ARG(link_proto_count[2][0]), U64_PRINTF_ARG(link_proto_count[3][0]), U64_PRINTF_ARG(link_proto_count[4][0])); } /** Free all storage held by the OR/link history caches, by the * bandwidth history arrays, by the port history, or by statistics . */ void rep_hist_free_all(void) { hs_stats_free(hs_stats); digestmap_free(history_map, free_or_history); bw_array_free(read_array); read_array = NULL; bw_array_free(write_array); write_array = NULL; bw_array_free(dir_read_array); dir_read_array = NULL; bw_array_free(dir_write_array); dir_write_array = NULL; tor_free(exit_bytes_read); tor_free(exit_bytes_written); tor_free(exit_streams); predicted_ports_free_all(); bidi_map_free_all(); if (circuits_for_buffer_stats) { SMARTLIST_FOREACH(circuits_for_buffer_stats, circ_buffer_stats_t *, s, tor_free(s)); smartlist_free(circuits_for_buffer_stats); circuits_for_buffer_stats = NULL; } rep_hist_desc_stats_term(); total_descriptor_downloads = 0; tor_assert_nonfatal(rephist_total_alloc == 0); tor_assert_nonfatal_once(rephist_total_num == 0); }