March 2013 - tor-commits - lists.torproject.org

[tor/master] Make sure expiry check in dirserv_expire_measured_bw_cache() works if time_t is unsigned
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit 302d1dae6c468fd2bd5551de654e36b8464a7eab Author: Andrea Shepard <andrea(a)torproject.org> Date: Thu Mar 7 05:10:54 2013 -0800 Make sure expiry check in dirserv_expire_measured_bw_cache() works if time_t is unsigned --- src/or/dirserv.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 1846dc1..3dfa1e7 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2125,7 +2125,7 @@ dirserv_expire_measured_bw_cache(time_t now) e = (mbw_cache_entry_t *)e_v; if (e) { /* Check for expiration and remove if so */ - if (now - e->as_of > MAX_MEASUREMENT_AGE) { + if (now > e->as_of + MAX_MEASUREMENT_AGE) { tor_free(e); rmv = 1; }

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[tor/master] More constness in dirserv.c
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit c7947619df826f6c4568c857178d54b8dee17749 Author: Andrea Shepard <andrea(a)torproject.org> Date: Thu Mar 7 05:05:56 2013 -0800 More constness in dirserv.c --- src/or/dirserv.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 1160f6b..1846dc1 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -90,9 +90,9 @@ static void dirserv_cache_measured_bw(const measured_bw_line_t *parsed_line, static void dirserv_clear_measured_bw_cache(void); static void dirserv_expire_measured_bw_cache(time_t now); static int dirserv_get_measured_bw_cache_size(void); -static int dirserv_query_measured_bw_cache(char *node_id, long *bw_out, +static int dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, time_t *as_of_out); -static uint32_t dirserv_get_bandwidth_for_router(routerinfo_t *ri); +static uint32_t dirserv_get_bandwidth_for_router(const routerinfo_t *ri); /************** Measured Bandwidth parsing code ******/ #define MAX_MEASUREMENT_AGE (3*24*60*60) /* 3 days */ @@ -2162,7 +2162,7 @@ dirserv_get_measured_bw_cache_size(void) /** Query the cache by identity digest, return value indicates whether * we found it. */ static int -dirserv_query_measured_bw_cache(char *node_id, long *bw_out, +dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, time_t *as_of_out) { mbw_cache_entry_t *v = NULL; @@ -2185,7 +2185,7 @@ dirserv_query_measured_bw_cache(char *node_id, long *bw_out, * preferring measured to advertised values if available. */ static uint32_t -dirserv_get_bandwidth_for_router(routerinfo_t *ri) +dirserv_get_bandwidth_for_router(const routerinfo_t *ri) { uint32_t bw = 0; /*

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[tor/master] Add unit test for dirserv measured bandwidth cache
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit 6e978ab8294eda5bb9a658c8d062bdd0098a9ac5 Author: Andrea Shepard <andrea(a)torproject.org> Date: Thu Mar 7 15:41:22 2013 -0800 Add unit test for dirserv measured bandwidth cache --- src/or/dirserv.c | 20 +++---------- src/or/dirserv.h | 12 ++++++++ src/test/test_dir.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 95 insertions(+), 15 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 3dfa1e7..e97def7 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -85,18 +85,8 @@ 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); -static void dirserv_cache_measured_bw(const measured_bw_line_t *parsed_line, - time_t as_of); -static void dirserv_clear_measured_bw_cache(void); -static void dirserv_expire_measured_bw_cache(time_t now); -static int dirserv_get_measured_bw_cache_size(void); -static int dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, - time_t *as_of_out); static uint32_t dirserv_get_bandwidth_for_router(const routerinfo_t *ri); -/************** Measured Bandwidth parsing code ******/ -#define MAX_MEASUREMENT_AGE (3*24*60*60) /* 3 days */ - /************** Fingerprint handling code ************/ #define FP_NAMED 1 /**< Listed in fingerprint file. */ @@ -2066,7 +2056,7 @@ static digestmap_t *mbw_cache = NULL; /** Store a measured bandwidth cache entry when reading the measured * bandwidths file. */ -static void +void dirserv_cache_measured_bw(const measured_bw_line_t *parsed_line, time_t as_of) { @@ -2096,7 +2086,7 @@ dirserv_cache_measured_bw(const measured_bw_line_t *parsed_line, } /** Clear and free the measured bandwidth cache */ -static void +void dirserv_clear_measured_bw_cache(void) { if (mbw_cache) { @@ -2107,7 +2097,7 @@ dirserv_clear_measured_bw_cache(void) } /** Scan the measured bandwidth cache and remove expired entries */ -static void +void dirserv_expire_measured_bw_cache(time_t now) { digestmap_iter_t *itr = NULL; @@ -2152,7 +2142,7 @@ dirserv_expire_measured_bw_cache(time_t now) } /** Get the current size of the measured bandwidth cache */ -static int +int dirserv_get_measured_bw_cache_size(void) { if (mbw_cache) return digestmap_size(mbw_cache); @@ -2161,7 +2151,7 @@ dirserv_get_measured_bw_cache_size(void) /** Query the cache by identity digest, return value indicates whether * we found it. */ -static int +int dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, time_t *as_of_out) { diff --git a/src/or/dirserv.h b/src/or/dirserv.h index 0caf55f..887a499 100644 --- a/src/or/dirserv.h +++ b/src/or/dirserv.h @@ -138,10 +138,22 @@ void cached_dir_decref(cached_dir_t *d); cached_dir_t *new_cached_dir(char *s, time_t published); #ifdef DIRSERV_PRIVATE + +/* Put the MAX_MEASUREMENT_AGE #define here so unit tests can see it */ +#define MAX_MEASUREMENT_AGE (3*24*60*60) /* 3 days */ + int measured_bw_line_parse(measured_bw_line_t *out, const char *line); int measured_bw_line_apply(measured_bw_line_t *parsed_line, smartlist_t *routerstatuses); + +void dirserv_cache_measured_bw(const measured_bw_line_t *parsed_line, + time_t as_of); +void dirserv_clear_measured_bw_cache(void); +void dirserv_expire_measured_bw_cache(time_t now); +int dirserv_get_measured_bw_cache_size(void); +int dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, + time_t *as_of_out); #endif int dirserv_read_measured_bandwidths(const char *from_file, diff --git a/src/test/test_dir.c b/src/test/test_dir.c index fbd49b7..667e8f4 100644 --- a/src/test/test_dir.c +++ b/src/test/test_dir.c @@ -575,6 +575,83 @@ test_dir_measured_bw(void) return; } +#define MBWC_INIT_TIME 1000 + +/** Do the measured bandwidth cache unit test */ +static void +test_dir_measured_bw_cache(void) +{ + /* Initial fake time_t for testing */ + time_t curr = MBWC_INIT_TIME; + /* Some measured_bw_line_ts */ + measured_bw_line_t mbwl[3]; + /* For receiving output on cache queries */ + long bw; + time_t as_of; + + /* First, clear the cache and assert that it's empty */ + dirserv_clear_measured_bw_cache(); + test_eq(dirserv_get_measured_bw_cache_size(), 0); + /* + * Set up test mbwls; none of the dirserv_cache_*() functions care about + * the node_hex field. + */ + memset(mbwl[0].node_id, 0x01, DIGEST_LEN); + mbwl[0].bw = 20; + memset(mbwl[1].node_id, 0x02, DIGEST_LEN); + mbwl[1].bw = 40; + memset(mbwl[2].node_id, 0x03, DIGEST_LEN); + mbwl[2].bw = 80; + /* Try caching something */ + dirserv_cache_measured_bw(&(mbwl[0]), curr); + test_eq(dirserv_get_measured_bw_cache_size(), 1); + /* Okay, let's see if we can retrieve it */ + test_assert(dirserv_query_measured_bw_cache(mbwl[0].node_id, &bw, &as_of)); + test_eq(bw, 20); + test_eq(as_of, MBWC_INIT_TIME); + /* Try retrieving it without some outputs */ + test_assert(dirserv_query_measured_bw_cache(mbwl[0].node_id, NULL, NULL)); + test_assert(dirserv_query_measured_bw_cache(mbwl[0].node_id, &bw, NULL)); + test_eq(bw, 20); + test_assert(dirserv_query_measured_bw_cache(mbwl[0].node_id, NULL, &as_of)); + test_eq(as_of, MBWC_INIT_TIME); + /* Now expire it */ + curr += MAX_MEASUREMENT_AGE + 1; + dirserv_expire_measured_bw_cache(curr); + /* Check that the cache is empty */ + test_eq(dirserv_get_measured_bw_cache_size(), 0); + /* Check that we can't retrieve it */ + test_assert(!dirserv_query_measured_bw_cache(mbwl[0].node_id, NULL, NULL)); + /* Try caching a few things now */ + dirserv_cache_measured_bw(&(mbwl[0]), curr); + test_eq(dirserv_get_measured_bw_cache_size(), 1); + curr += MAX_MEASUREMENT_AGE / 4; + dirserv_cache_measured_bw(&(mbwl[1]), curr); + test_eq(dirserv_get_measured_bw_cache_size(), 2); + curr += MAX_MEASUREMENT_AGE / 4; + dirserv_cache_measured_bw(&(mbwl[2]), curr); + test_eq(dirserv_get_measured_bw_cache_size(), 3); + curr += MAX_MEASUREMENT_AGE / 4 + 1; + /* Do an expire that's too soon to get any of them */ + dirserv_expire_measured_bw_cache(curr); + test_eq(dirserv_get_measured_bw_cache_size(), 3); + /* Push the oldest one off the cliff */ + curr += MAX_MEASUREMENT_AGE / 4; + dirserv_expire_measured_bw_cache(curr); + test_eq(dirserv_get_measured_bw_cache_size(), 2); + /* And another... */ + curr += MAX_MEASUREMENT_AGE / 4; + dirserv_expire_measured_bw_cache(curr); + test_eq(dirserv_get_measured_bw_cache_size(), 1); + /* This should empty it out again */ + curr += MAX_MEASUREMENT_AGE / 4; + dirserv_expire_measured_bw_cache(curr); + test_eq(dirserv_get_measured_bw_cache_size(), 0); + + done: + return; +} + static void test_dir_param_voting(void) { @@ -2141,6 +2218,7 @@ struct testcase_t dir_tests[] = { DIR(scale_bw), DIR_LEGACY(clip_unmeasured_bw), DIR_LEGACY(clip_unmeasured_bw_alt), + DIR_LEGACY(measured_bw_cache), END_OF_TESTCASES };

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[tor/master] Use DIGESTMAP_FOREACH_MODIFY in dirserv_expire_measured_bw_cache() for concision
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit b5224348340238f231f81138c09f7f16541d0f1d Author: Andrea Shepard <andrea(a)torproject.org> Date: Thu Mar 7 15:55:01 2013 -0800 Use DIGESTMAP_FOREACH_MODIFY in dirserv_expire_measured_bw_cache() for concision --- src/or/dirserv.c | 35 ++++++----------------------------- 1 files changed, 6 insertions(+), 29 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index e97def7..b6ff6f6 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2100,38 +2100,15 @@ dirserv_clear_measured_bw_cache(void) void dirserv_expire_measured_bw_cache(time_t now) { - digestmap_iter_t *itr = NULL; - const char *k = NULL; - void *e_v = NULL; - mbw_cache_entry_t *e = NULL; - int rmv; if (mbw_cache) { - /* Start iterating */ - itr = digestmap_iter_init(mbw_cache); - while (!digestmap_iter_done(itr)) { - rmv = 0; - digestmap_iter_get(itr, &k, &e_v); - e = (mbw_cache_entry_t *)e_v; - if (e) { - /* Check for expiration and remove if so */ - if (now > e->as_of + MAX_MEASUREMENT_AGE) { - tor_free(e); - rmv = 1; - } - } else { - /* Weird; remove it and complain */ - log_warn(LD_BUG, "Saw NULL entry in measured bandwidth cache"); - rmv = 1; + /* 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); } - - /* Advance, or remove and advance */ - if (rmv) { - itr = digestmap_iter_next_rmv(mbw_cache, itr); - } else { - itr = digestmap_iter_next(mbw_cache, itr); - } - } + } DIGESTMAP_FOREACH_END; /* Check if we cleared the whole thing and free if so */ if (digestmap_size(mbw_cache) == 0) {

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[tor/master] Add dirserv_has_measured_bw() predicate wrapper for dirserv_query_measured_bw_cache()
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit d64e5969f470a18fe15a6a2863cf4b2b59b1bd27 Author: Andrea Shepard <andrea(a)torproject.org> Date: Mon Mar 18 11:56:42 2013 -0700 Add dirserv_has_measured_bw() predicate wrapper for dirserv_query_measured_bw_cache() --- src/or/dirserv.c | 13 +++++++++---- src/or/dirserv.h | 1 + 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index c769bed..47a4a73 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -1886,8 +1886,7 @@ router_counts_toward_thresholds(const node_t *node, time_t now, { /* Have measured bw? */ int have_mbw = - dirserv_query_measured_bw_cache(node->ri->cache_info.identity_digest, - NULL, NULL); + dirserv_has_measured_bw(node->ri->cache_info.identity_digest); return node->ri && router_is_active(node->ri, node, now) && !digestmap_get(omit_as_sybil, node->ri->cache_info.identity_digest) && @@ -2166,6 +2165,13 @@ dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, 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. */ @@ -2214,8 +2220,7 @@ dirserv_count_measured_bws(routerlist_t *rl) /* 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_query_measured_bw_cache(ri->cache_info.identity_digest, - NULL, NULL)) { + if (dirserv_has_measured_bw(ri->cache_info.identity_digest)) { ++routers_with_measured_bw; } } SMARTLIST_FOREACH_END(ri); diff --git a/src/or/dirserv.h b/src/or/dirserv.h index 887a499..8728a0b 100644 --- a/src/or/dirserv.h +++ b/src/or/dirserv.h @@ -154,6 +154,7 @@ void dirserv_expire_measured_bw_cache(time_t now); int dirserv_get_measured_bw_cache_size(void); int dirserv_query_measured_bw_cache(const char *node_id, long *bw_out, time_t *as_of_out); +int dirserv_has_measured_bw(const char *node_id); #endif int dirserv_read_measured_bandwidths(const char *from_file,

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[tor/master] Better comment for dirserv_query_measured_bw_cache()
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit 8027ebb5fdf43b5aa63e498c1f8e3c6b2c87bbb7 Author: Andrea Shepard <andrea(a)torproject.org> Date: Thu Mar 7 15:59:30 2013 -0800 Better comment for dirserv_query_measured_bw_cache() --- src/or/dirserv.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index b6ff6f6..37934a0 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2127,7 +2127,8 @@ dirserv_get_measured_bw_cache_size(void) } /** Query the cache by identity digest, return value indicates whether - * we found it. */ + * 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)

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[tor/master] Improve comment on router_counts_toward_thresholds()
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit e9bdb695e82320fd320ba7e9c716ebdc51bfdeb0 Author: Andrea Shepard <andrea(a)torproject.org> Date: Mon Mar 18 11:58:30 2013 -0700 Improve comment on router_counts_toward_thresholds() --- src/or/dirserv.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 47a4a73..cf11e50 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -1878,7 +1878,10 @@ 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,

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[tor/master] Ignore advertised bandwidths if we have enough measured bandwidths available
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit f93f7e331be94114d82c17108e741eb2482e6bda Author: Andrea Shepard <andrea(a)torproject.org> Date: Mon Mar 18 11:15:21 2013 -0700 Ignore advertised bandwidths if we have enough measured bandwidths available --- changes/bug8435 | 4 ++ src/or/config.c | 1 + src/or/dirserv.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++---- src/or/or.h | 4 ++ 4 files changed, 99 insertions(+), 7 deletions(-) diff --git a/changes/bug8435 b/changes/bug8435 new file mode 100644 index 0000000..da7ca7c --- /dev/null +++ b/changes/bug8435 @@ -0,0 +1,4 @@ + o Major bugfixes: + - When dirserv.c computes flags and thresholds, ignore advertised + bandwidths if we have more than a threshold number of routers with + measured bandwidths. diff --git a/src/or/config.c b/src/or/config.c index f888426..f3e4083 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -299,6 +299,7 @@ static config_var_t option_vars_[] = { V(MaxClientCircuitsPending, UINT, "32"), OBSOLETE("MaxOnionsPending"), V(MaxOnionQueueDelay, MSEC_INTERVAL, "1750 msec"), + V(MinMeasuredBWsForAuthToIgnoreAdvertised, INT, "500"), OBSOLETE("MonthlyAccountingStart"), V(MyFamily, STRING, NULL), V(NewCircuitPeriod, INTERVAL, "30 seconds"), diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 37934a0..c769bed 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -66,6 +66,9 @@ 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 */ +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); @@ -86,6 +89,7 @@ static const signed_descriptor_t *get_signed_descriptor_by_fp( static was_router_added_t dirserv_add_extrainfo(extrainfo_t *ei, const char **msg); 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 ************/ @@ -1877,12 +1881,18 @@ dirserv_thinks_router_is_hs_dir(const routerinfo_t *router, * include a router in our calculations, and return true iff we should. */ 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_query_measured_bw_cache(node->ri->cache_info.identity_digest, + NULL, NULL); + return node->ri && router_is_active(node->ri, node, now) && !digestmap_get(omit_as_sybil, node->ri->cache_info.identity_digest) && - (dirserv_get_bandwidth_for_router(node->ri) >= - ABSOLUTE_MIN_BW_VALUE_TO_CONSIDER); + (dirserv_get_credible_bandwidth(node->ri) >= + ABSOLUTE_MIN_BW_VALUE_TO_CONSIDER) && (have_mbw || !require_mbw); } /** Look through the routerlist, the Mean Time Between Failure history, and @@ -1904,6 +1914,11 @@ 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; @@ -1936,7 +1951,8 @@ 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; @@ -1945,7 +1961,7 @@ 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 = dirserv_get_bandwidth_for_router(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; @@ -2001,7 +2017,8 @@ 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); @@ -2182,6 +2199,59 @@ dirserv_get_bandwidth_for_router(const routerinfo_t *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_query_measured_bw_cache(ri->cache_info.identity_digest, + NULL, NULL)) { + ++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 * @@ -2604,7 +2674,7 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs, int listbaddirs, int vote_on_hsdirs) { const or_options_t *options = get_options(); - uint32_t routerbw = dirserv_get_bandwidth_for_router(ri); + uint32_t routerbw = dirserv_get_credible_bandwidth(ri); memset(rs, 0, sizeof(routerstatus_t)); @@ -2927,6 +2997,14 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, */ 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" @@ -2945,6 +3023,10 @@ 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(); @@ -2989,6 +3071,7 @@ 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); diff --git a/src/or/or.h b/src/or/or.h index 45eb467..f2605d6 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -3870,6 +3870,10 @@ typedef struct { * consensus vote on the 'params' line. */ char *ConsensusParams; + /** Authority only: minimum number of measured bandwidths we must see + * before we only beliee measured bandwidths to assign flags. */ + int MinMeasuredBWsForAuthToIgnoreAdvertised; + /** The length of time that we think an initial consensus should be fresh. * Only altered on testing networks. */ int TestingV3AuthInitialVotingInterval;

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[tor/master] Improve comment for routers_with_measured_bw static var in dirserv.c
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit 0164f16f70d17da202c8085e620e9cf043eda0b3 Author: Andrea Shepard <andrea(a)torproject.org> Date: Mon Mar 18 12:04:41 2013 -0700 Improve comment for routers_with_measured_bw static var in dirserv.c --- src/or/dirserv.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/src/or/dirserv.c b/src/or/dirserv.c index cf11e50..5aed3fb 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -66,7 +66,11 @@ 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 */ +/** 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);

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[tor/master] Merge remote-tracking branch 'origin/maint-0.2.4'
by nickm＠torproject.org 18 Mar '13

18 Mar '13

commit 67709398b6bb1cea68b8c2a0060b251e8dfa86ee Merge: 41cff47 5959d1c Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon Mar 18 15:18:56 2013 -0400 Merge remote-tracking branch 'origin/maint-0.2.4' changes/bug8273 | 3 + changes/bug8435 | 4 + src/or/config.c | 1 + src/or/dirserv.c | 288 ++++++++++++++++++++++++++++++++++++++++++++++++--- src/or/dirserv.h | 13 +++ src/or/or.h | 4 + src/test/test_dir.c | 78 ++++++++++++++ 7 files changed, 375 insertions(+), 16 deletions(-)

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