diff options
Diffstat (limited to 'src/or/dirserv.c')
| -rw-r--r-- | src/or/dirserv.c | 302 |
1 files changed, 284 insertions, 18 deletions
diff --git a/src/or/dirserv.c b/src/or/dirserv.c index badacd683d..e837e4bed5 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -66,6 +66,13 @@ static cached_dir_t *the_directory = NULL; /** For authoritative directories: the current (v1) network status. */ static cached_dir_t the_runningrouters; +/** Total number of routers with measured bandwidth; this is set by + * dirserv_count_measured_bws() before the loop in + * dirserv_generate_networkstatus_vote_obj() and checked by + * dirserv_get_credible_bandwidth() and + * dirserv_compute_performance_thresholds() */ +static int routers_with_measured_bw = 0; + static void directory_remove_invalid(void); static cached_dir_t *dirserv_regenerate_directory(void); static char *format_versions_list(config_line_t *ln); @@ -85,9 +92,8 @@ static const signed_descriptor_t *get_signed_descriptor_by_fp( time_t publish_cutoff); static was_router_added_t dirserv_add_extrainfo(extrainfo_t *ei, const char **msg); - -/************** Measured Bandwidth parsing code ******/ -#define MAX_MEASUREMENT_AGE (3*24*60*60) /* 3 days */ +static uint32_t dirserv_get_bandwidth_for_router(const routerinfo_t *ri); +static uint32_t dirserv_get_credible_bandwidth(const routerinfo_t *ri); /************** Fingerprint handling code ************/ @@ -1824,7 +1830,7 @@ dirserv_thinks_router_is_unreliable(time_t now, } } if (need_capacity) { - uint32_t bw = router_get_advertised_bandwidth(router); + uint32_t bw = dirserv_get_bandwidth_for_router(router); if (bw < fast_bandwidth) return 1; } @@ -1876,15 +1882,29 @@ dirserv_thinks_router_is_hs_dir(const routerinfo_t *router, #define ABSOLUTE_MIN_BW_VALUE_TO_CONSIDER 4096 /** Helper for dirserv_compute_performance_thresholds(): Decide whether to - * include a router in our calculations, and return true iff we should. */ + * include a router in our calculations, and return true iff we should; the + * require_mbw parameter is passed in by + * dirserv_compute_performance_thresholds() and controls whether we ever + * count routers with only advertised bandwidths */ static int router_counts_toward_thresholds(const node_t *node, time_t now, - const digestmap_t *omit_as_sybil) + const digestmap_t *omit_as_sybil, + int require_mbw) { + /* Have measured bw? */ + int have_mbw = + dirserv_has_measured_bw(node->ri->cache_info.identity_digest); + uint64_t min_bw = ABSOLUTE_MIN_BW_VALUE_TO_CONSIDER; + const or_options_t *options = get_options(); + + if (options->TestingTorNetwork) { + min_bw = (int64_t)options->TestingMinExitFlagThreshold; + } + return node->ri && router_is_active(node->ri, node, now) && !digestmap_get(omit_as_sybil, node->ri->cache_info.identity_digest) && - (router_get_advertised_bandwidth(node->ri) >= - ABSOLUTE_MIN_BW_VALUE_TO_CONSIDER); + (dirserv_get_credible_bandwidth(node->ri) >= min_bw) && + (have_mbw || !require_mbw); } /** Look through the routerlist, the Mean Time Between Failure history, and @@ -1906,6 +1926,11 @@ dirserv_compute_performance_thresholds(routerlist_t *rl, time_t now = time(NULL); const or_options_t *options = get_options(); + /* Require mbw? */ + int require_mbw = + (routers_with_measured_bw > + options->MinMeasuredBWsForAuthToIgnoreAdvertised) ? 1 : 0; + /* initialize these all here, in case there are no routers */ stable_uptime = 0; stable_mtbf = 0; @@ -1938,7 +1963,8 @@ dirserv_compute_performance_thresholds(routerlist_t *rl, /* Now, fill in the arrays. */ SMARTLIST_FOREACH_BEGIN(nodelist_get_list(), node_t *, node) { - if (router_counts_toward_thresholds(node, now, omit_as_sybil)) { + if (router_counts_toward_thresholds(node, now, omit_as_sybil, + require_mbw)) { routerinfo_t *ri = node->ri; const char *id = ri->cache_info.identity_digest; uint32_t bw; @@ -1947,7 +1973,7 @@ dirserv_compute_performance_thresholds(routerlist_t *rl, uptimes[n_active] = (uint32_t)real_uptime(ri, now); mtbfs[n_active] = rep_hist_get_stability(id, now); tks [n_active] = rep_hist_get_weighted_time_known(id, now); - bandwidths[n_active] = bw = router_get_advertised_bandwidth(ri); + bandwidths[n_active] = bw = dirserv_get_credible_bandwidth(ri); total_bandwidth += bw; if (node->is_exit && !node->is_bad_exit) { total_exit_bandwidth += bw; @@ -1985,6 +2011,9 @@ dirserv_compute_performance_thresholds(routerlist_t *rl, ABSOLUTE_MIN_VALUE_FOR_FAST_FLAG, ABSOLUTE_MIN_VALUE_FOR_FAST_FLAG, INT32_MAX); + if (options->TestingTorNetwork) { + min_fast = (int32_t)options->TestingMinFastFlagThreshold; + } max_fast = networkstatus_get_param(NULL, "FastFlagMaxThreshold", INT32_MAX, min_fast, INT32_MAX); if (fast_bandwidth < (uint32_t)min_fast) @@ -2003,7 +2032,8 @@ dirserv_compute_performance_thresholds(routerlist_t *rl, n_familiar = 0; SMARTLIST_FOREACH_BEGIN(nodelist_get_list(), node_t *, node) { - if (router_counts_toward_thresholds(node, now, omit_as_sybil)) { + if (router_counts_toward_thresholds(node, now, + omit_as_sybil, require_mbw)) { routerinfo_t *ri = node->ri; const char *id = ri->cache_info.identity_digest; long tk = rep_hist_get_weighted_time_known(id, now); @@ -2046,6 +2076,203 @@ dirserv_compute_performance_thresholds(routerlist_t *rl, tor_free(wfus); } +/** Measured bandwidth cache entry */ +typedef struct mbw_cache_entry_s { + long mbw; + time_t as_of; +} mbw_cache_entry_t; + +/** Measured bandwidth cache - keys are identity_digests, values are + * mbw_cache_entry_t *. */ +static digestmap_t *mbw_cache = NULL; + +/** Store a measured bandwidth cache entry when reading the measured + * bandwidths file. */ +void +dirserv_cache_measured_bw(const measured_bw_line_t *parsed_line, + time_t as_of) +{ + mbw_cache_entry_t *e = NULL; + + tor_assert(parsed_line); + + /* Allocate a cache if we need */ + if (!mbw_cache) mbw_cache = digestmap_new(); + + /* Check if we have an existing entry */ + e = digestmap_get(mbw_cache, parsed_line->node_id); + /* If we do, we can re-use it */ + if (e) { + /* Check that we really are newer, and update */ + if (as_of > e->as_of) { + e->mbw = parsed_line->bw; + e->as_of = as_of; + } + } else { + /* We'll have to insert a new entry */ + e = tor_malloc(sizeof(*e)); + e->mbw = parsed_line->bw; + e->as_of = as_of; + digestmap_set(mbw_cache, parsed_line->node_id, e); + } +} + +/** Clear and free the measured bandwidth cache */ +void +dirserv_clear_measured_bw_cache(void) +{ + if (mbw_cache) { + /* Free the map and all entries */ + digestmap_free(mbw_cache, tor_free_); + mbw_cache = NULL; + } +} + +/** Scan the measured bandwidth cache and remove expired entries */ +void +dirserv_expire_measured_bw_cache(time_t now) +{ + + if (mbw_cache) { + /* Iterate through the cache and check each entry */ + DIGESTMAP_FOREACH_MODIFY(mbw_cache, k, mbw_cache_entry_t *, e) { + if (now > e->as_of + MAX_MEASUREMENT_AGE) { + tor_free(e); + MAP_DEL_CURRENT(k); + } + } DIGESTMAP_FOREACH_END; + + /* Check if we cleared the whole thing and free if so */ + if (digestmap_size(mbw_cache) == 0) { + digestmap_free(mbw_cache, tor_free_); + mbw_cache = 0; + } + } +} + +/** Get the current size of the measured bandwidth cache */ +int +dirserv_get_measured_bw_cache_size(void) +{ + if (mbw_cache) return digestmap_size(mbw_cache); + else return 0; +} + +/** Query the cache by identity digest, return value indicates whether + * we found it. The bw_out and as_of_out pointers receive the cached + * bandwidth value and the time it was cached if not NULL. */ +int +dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, + time_t *as_of_out) +{ + mbw_cache_entry_t *v = NULL; + int rv = 0; + + if (mbw_cache && node_id) { + v = digestmap_get(mbw_cache, node_id); + if (v) { + /* Found something */ + rv = 1; + if (bw_out) *bw_out = v->mbw; + if (as_of_out) *as_of_out = v->as_of; + } + } + + return rv; +} + +/** Predicate wrapper for dirserv_query_measured_bw_cache() */ +int +dirserv_has_measured_bw(const char *node_id) +{ + return dirserv_query_measured_bw_cache(node_id, NULL, NULL); +} + +/** Get the best estimate of a router's bandwidth for dirauth purposes, + * preferring measured to advertised values if available. */ + +static uint32_t +dirserv_get_bandwidth_for_router(const routerinfo_t *ri) +{ + uint32_t bw = 0; + /* + * Yeah, measured bandwidths in measured_bw_line_t are (implicitly + * signed) longs and the ones router_get_advertised_bandwidth() returns + * are uint32_t. + */ + long mbw = 0; + + if (ri) { + /* + * * First try to see if we have a measured bandwidth; don't bother with + * as_of_out here, on the theory that a stale measured bandwidth is still + * better to trust than an advertised one. + */ + if (dirserv_query_measured_bw_cache(ri->cache_info.identity_digest, + &mbw, NULL)) { + /* Got one! */ + bw = (uint32_t)mbw; + } else { + /* If not, fall back to advertised */ + bw = router_get_advertised_bandwidth(ri); + } + } + + return bw; +} + +/** Look through the routerlist, and using the measured bandwidth cache count + * how many measured bandwidths we know. This is used to decide whether we + * ever trust advertised bandwidths for purposes of assigning flags. */ +static void +dirserv_count_measured_bws(routerlist_t *rl) +{ + /* Initialize this first */ + routers_with_measured_bw = 0; + + tor_assert(rl); + tor_assert(rl->routers); + + /* Iterate over the routerlist and count measured bandwidths */ + SMARTLIST_FOREACH_BEGIN(rl->routers, routerinfo_t *, ri) { + /* Check if we know a measured bandwidth for this one */ + if (dirserv_has_measured_bw(ri->cache_info.identity_digest)) { + ++routers_with_measured_bw; + } + } SMARTLIST_FOREACH_END(ri); +} + +/** Return the bandwidth we believe for assigning flags; prefer measured + * over advertised, and if we have above a threshold quantity of measured + * bandwidths, we don't want to ever give flags to unmeasured routers, so + * return 0. */ +static uint32_t +dirserv_get_credible_bandwidth(const routerinfo_t *ri) +{ + int threshold; + uint32_t bw = 0; + long mbw; + + tor_assert(ri); + /* Check if we have a measured bandwidth, and check the threshold if not */ + if (!(dirserv_query_measured_bw_cache(ri->cache_info.identity_digest, + &mbw, NULL))) { + threshold = get_options()->MinMeasuredBWsForAuthToIgnoreAdvertised; + if (routers_with_measured_bw > threshold) { + /* Return zero for unmeasured bandwidth if we are above threshold */ + bw = 0; + } else { + /* Return an advertised bandwidth otherwise */ + bw = router_get_advertised_bandwidth(ri); + } + } else { + /* We have the measured bandwidth in mbw */ + bw = (uint32_t)mbw; + } + + return bw; +} + /** Give a statement of our current performance thresholds for inclusion * in a vote document. */ char * @@ -2216,9 +2443,10 @@ routerstatus_format_entry(char *buf, size_t buf_len, return -1; } - /* This assert can fire for the control port, because + /* This assert could fire for the control port, because * it can request NS documents before all descriptors - * have been fetched. */ + * have been fetched. Therefore, we only do this test when + * format != NS_CONTROL_PORT. */ if (tor_memneq(desc->cache_info.signed_descriptor_digest, rs->descriptor_digest, DIGEST_LEN)) { @@ -2327,8 +2555,8 @@ compare_routerinfo_by_ip_and_bw_(const void **a, const void **b) else if (!first_is_running && second_is_running) return 1; - bw_first = router_get_advertised_bandwidth(first); - bw_second = router_get_advertised_bandwidth(second); + bw_first = dirserv_get_bandwidth_for_router(first); + bw_second = dirserv_get_bandwidth_for_router(second); if (bw_first > bw_second) return -1; @@ -2468,7 +2696,7 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs, int listbaddirs, int vote_on_hsdirs) { const or_options_t *options = get_options(); - uint32_t routerbw = router_get_advertised_bandwidth(ri); + uint32_t routerbw = dirserv_get_credible_bandwidth(ri); memset(rs, 0, sizeof(routerstatus_t)); @@ -2670,8 +2898,9 @@ dirserv_read_measured_bandwidths(const char *from_file, char line[256]; FILE *fp = tor_fopen_cloexec(from_file, "r"); int applied_lines = 0; - time_t file_time; + time_t file_time, now; int ok; + if (fp == NULL) { log_warn(LD_CONFIG, "Can't open bandwidth file at configured location: %s", from_file); @@ -2695,7 +2924,8 @@ dirserv_read_measured_bandwidths(const char *from_file, return -1; } - if ((time(NULL) - file_time) > MAX_MEASUREMENT_AGE) { + now = time(NULL); + if ((now - file_time) > MAX_MEASUREMENT_AGE) { log_warn(LD_DIRSERV, "Bandwidth measurement file stale. Age: %u", (unsigned)(time(NULL) - file_time)); fclose(fp); @@ -2709,12 +2939,17 @@ dirserv_read_measured_bandwidths(const char *from_file, measured_bw_line_t parsed_line; if (fgets(line, sizeof(line), fp) && strlen(line)) { if (measured_bw_line_parse(&parsed_line, line) != -1) { + /* Also cache the line for dirserv_get_bandwidth_for_router() */ + dirserv_cache_measured_bw(&parsed_line, file_time); if (measured_bw_line_apply(&parsed_line, routerstatuses) > 0) applied_lines++; } } } + /* Now would be a nice time to clean the cache, too */ + dirserv_expire_measured_bw_cache(now); + fclose(fp); log_info(LD_DIRSERV, "Bandwidth measurement file successfully read. " @@ -2778,6 +3013,22 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, if (!contact) contact = "(none)"; + /* + * Do this so dirserv_compute_performance_thresholds() and + * set_routerstatus_from_routerinfo() see up-to-date bandwidth info. + */ + if (options->V3BandwidthsFile) { + dirserv_read_measured_bandwidths(options->V3BandwidthsFile, NULL); + } else { + /* + * No bandwidths file; clear the measured bandwidth cache in case we had + * one last time around. + */ + if (dirserv_get_measured_bw_cache_size() > 0) { + dirserv_clear_measured_bw_cache(); + } + } + /* precompute this part, since we need it to decide what "stable" * means. */ SMARTLIST_FOREACH(rl->routers, routerinfo_t *, ri, { @@ -2794,6 +3045,10 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, rep_hist_make_router_pessimal(sybil_id, now); } DIGESTMAP_FOREACH_END; + /* Count how many have measured bandwidths so we know how to assign flags; + * this must come before dirserv_compute_performance_thresholds() */ + dirserv_count_measured_bws(rl); + dirserv_compute_performance_thresholds(rl, omit_as_sybil); routerstatuses = smartlist_new(); @@ -2838,9 +3093,18 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, smartlist_free(routers); digestmap_free(omit_as_sybil, NULL); + /* This pass through applies the measured bw lines to the routerstatuses */ if (options->V3BandwidthsFile) { dirserv_read_measured_bandwidths(options->V3BandwidthsFile, routerstatuses); + } else { + /* + * No bandwidths file; clear the measured bandwidth cache in case we had + * one last time around. + */ + if (dirserv_get_measured_bw_cache_size() > 0) { + dirserv_clear_measured_bw_cache(); + } } v3_out = tor_malloc_zero(sizeof(networkstatus_t)); @@ -3908,5 +4172,7 @@ dirserv_free_all(void) cached_v2_networkstatus = NULL; strmap_free(cached_consensuses, free_cached_dir_); cached_consensuses = NULL; + + dirserv_clear_measured_bw_cache(); } |