/** Parse a file containing router descriptors and load them to our
routerlist. This function is used to setup an artificial network
so that we can conduct tests on it. */
void
helper_setup_fake_routerlist(void)
{
int retval;
routerlist_t *our_routerlist = NULL;
smartlist_t *our_nodelist = NULL;
/* Read the file that contains our test descriptors. */
/* We need to mock this function otherwise the descriptors will not
accepted as they are too old. */
MOCK(router_descriptor_is_older_than,
router_descriptor_is_older_than_replacement);
/* Load all the test descriptors to the routerlist. */
retval = router_load_routers_from_string(TEST_DESCRIPTORS,
NULL, SAVED_IN_JOURNAL,
NULL, 0, NULL);
tt_int_op(retval, ==, HELPER_NUMBER_OF_DESCRIPTORS);
/* Sanity checking of routerlist and nodelist. */
our_routerlist = router_get_routerlist();
tt_int_op(smartlist_len(our_routerlist->routers), ==,
HELPER_NUMBER_OF_DESCRIPTORS);
routerlist_assert_ok(our_routerlist);
our_nodelist = nodelist_get_list();
tt_int_op(smartlist_len(our_nodelist), ==, HELPER_NUMBER_OF_DESCRIPTORS);
/* Mark all routers as non-guards but up and running! */
SMARTLIST_FOREACH_BEGIN(our_nodelist, node_t *, node) {
node->is_running = 1;
node->is_valid = 1;
node->is_possible_guard = 0;
} SMARTLIST_FOREACH_END(node);
/** Helper to conduct tests for populate_live_entry_guards().
This test adds some entry guards to our list, and then tests
populate_live_entry_guards() to mke sure it filters them correctly.
<b>num_needed</b> is the number of guard nodes we support. It's
configurable to make sure we function properly with 1 or 3 guard
nodes configured.
*/
static void
populate_live_entry_guards_test_helper(int num_needed)
{
smartlist_t *our_nodelist = NULL;
smartlist_t *live_entry_guards = smartlist_new();
const smartlist_t *all_entry_guards = get_entry_guards();
or_options_t *options = get_options_mutable();
int retval;
/* Set NumEntryGuards to the provided number. */
options->NumEntryGuards = num_needed;
tt_int_op(num_needed, OP_EQ, decide_num_guards(options, 0));
/* The global entry guards smartlist should be empty now. */
tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 0);
/* Walk the nodelist and add all nodes as entry guards. */
our_nodelist = nodelist_get_list();
tt_int_op(smartlist_len(our_nodelist), OP_EQ, NUMBER_OF_DESCRIPTORS);
SMARTLIST_FOREACH_BEGIN(our_nodelist, const node_t *, node) {
const node_t *node_tmp;
node_tmp = add_an_entry_guard(node, 0, 1, 0, 0);
tt_assert(node_tmp);
} SMARTLIST_FOREACH_END(node);
/* Make sure the nodes were added as entry guards. */
tt_int_op(smartlist_len(all_entry_guards), OP_EQ, NUMBER_OF_DESCRIPTORS);
/* Ensure that all the possible entry guards are enough to satisfy us. */
tt_int_op(smartlist_len(all_entry_guards), OP_GE, num_needed);
/* Walk the entry guard list for some sanity checking */
SMARTLIST_FOREACH_BEGIN(all_entry_guards, const entry_guard_t *, entry) {
/* Since we called add_an_entry_guard() with 'for_discovery' being
False, all guards should have made_contact enabled. */
tt_int_op(entry->made_contact, OP_EQ, 1);
/* Since we don't have a routerstatus, all of the entry guards are
not directory servers. */
tt_int_op(entry->is_dir_cache, OP_EQ, 0);
} SMARTLIST_FOREACH_END(entry);
/** Test choose_random_entry() with only one of our routers being a
guard node. */
static void
test_choose_random_entry_one_possible_guard(void *arg)
{
const node_t *chosen_entry = NULL;
node_t *the_guard = NULL;
smartlist_t *our_nodelist = NULL;
(void) arg;
/* Set one of the nodes to be a guard. */
our_nodelist = nodelist_get_list();
the_guard = smartlist_get(our_nodelist, 4); /* chosen by fair dice roll */
the_guard->is_possible_guard = 1;
/* Pick an entry. Make sure we pick the node we marked as guard. */
chosen_entry = choose_random_entry(NULL);
tt_ptr_op(chosen_entry, OP_EQ, the_guard);
done:
;
}
/** Look through the routerlist, the Mean Time Between Failure history, and
* the Weighted Fractional Uptime history, and use them to set thresholds for
* the Stable, Fast, and Guard flags. Update the fields stable_uptime,
* stable_mtbf, enough_mtbf_info, guard_wfu, guard_tk, fast_bandwidth,
* guard_bandwidth_including_exits, and guard_bandwidth_excluding_exits.
*
* Also, set the is_exit flag of each router appropriately. */
void
dirserv_compute_performance_thresholds(digestmap_t *omit_as_sybil)
{
int n_active, n_active_nonexit, n_familiar;
uint32_t *uptimes, *bandwidths_kb, *bandwidths_excluding_exits_kb;
long *tks;
double *mtbfs, *wfus;
smartlist_t *nodelist;
time_t now = time(NULL);
const or_options_t *options = get_options();
/* Require mbw? */
int require_mbw =
(dirserv_get_last_n_measured_bws() >
options->MinMeasuredBWsForAuthToIgnoreAdvertised) ? 1 : 0;
/* initialize these all here, in case there are no routers */
stable_uptime = 0;
stable_mtbf = 0;
fast_bandwidth_kb = 0;
guard_bandwidth_including_exits_kb = 0;
guard_bandwidth_excluding_exits_kb = 0;
guard_tk = 0;
guard_wfu = 0;
nodelist_assert_ok();
nodelist = nodelist_get_list();
/* Initialize arrays that will hold values for each router. We'll
* sort them and use that to compute thresholds. */
n_active = n_active_nonexit = 0;
/* Uptime for every active router. */
uptimes = tor_calloc(smartlist_len(nodelist), sizeof(uint32_t));
/* Bandwidth for every active router. */
bandwidths_kb = tor_calloc(smartlist_len(nodelist), sizeof(uint32_t));
/* Bandwidth for every active non-exit router. */
bandwidths_excluding_exits_kb =
tor_calloc(smartlist_len(nodelist), sizeof(uint32_t));
/* Weighted mean time between failure for each active router. */
mtbfs = tor_calloc(smartlist_len(nodelist), sizeof(double));
/* Time-known for each active router. */
tks = tor_calloc(smartlist_len(nodelist), sizeof(long));
/* Weighted fractional uptime for each active router. */
wfus = tor_calloc(smartlist_len(nodelist), sizeof(double));
/* Now, fill in the arrays. */
SMARTLIST_FOREACH_BEGIN(nodelist, node_t *, node) {
if (options->BridgeAuthoritativeDir &&
node->ri &&
node->ri->purpose != ROUTER_PURPOSE_BRIDGE)
continue;
routerinfo_t *ri = node->ri;
if (ri) {
node->is_exit = (!router_exit_policy_rejects_all(ri) &&
exit_policy_is_general_exit(ri->exit_policy));
}
if (router_counts_toward_thresholds(node, now, omit_as_sybil,
require_mbw)) {
const char *id = node->identity;
uint32_t bw_kb;
/* resolve spurious clang shallow analysis null pointer errors */
tor_assert(ri);
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_kb[n_active] = bw_kb = dirserv_get_credible_bandwidth_kb(ri);
if (!node->is_exit || node->is_bad_exit) {
bandwidths_excluding_exits_kb[n_active_nonexit] = bw_kb;
++n_active_nonexit;
}
++n_active;
}
} SMARTLIST_FOREACH_END(node);
/* Now, compute thresholds. */
if (n_active) {
/* The median uptime is stable. */
stable_uptime = median_uint32(uptimes, n_active);
/* The median mtbf is stable, if we have enough mtbf info */
stable_mtbf = median_double(mtbfs, n_active);
/* The 12.5th percentile bandwidth is fast. */
fast_bandwidth_kb = find_nth_uint32(bandwidths_kb, n_active, n_active/8);
/* (Now bandwidths is sorted.) */
if (fast_bandwidth_kb < RELAY_REQUIRED_MIN_BANDWIDTH/(2 * 1000))
fast_bandwidth_kb = bandwidths_kb[n_active/4];
guard_bandwidth_including_exits_kb =
third_quartile_uint32(bandwidths_kb, n_active);
guard_tk = find_nth_long(tks, n_active, n_active/8);
}
if (guard_tk > TIME_KNOWN_TO_GUARANTEE_FAMILIAR)
guard_tk = TIME_KNOWN_TO_GUARANTEE_FAMILIAR;
{
/* We can vote on a parameter for the minimum and maximum. */
#define ABSOLUTE_MIN_VALUE_FOR_FAST_FLAG 4
int32_t min_fast_kb, max_fast_kb, min_fast, max_fast;
min_fast = networkstatus_get_param(NULL, "FastFlagMinThreshold",
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);
min_fast_kb = min_fast / 1000;
max_fast_kb = max_fast / 1000;
if (fast_bandwidth_kb < (uint32_t)min_fast_kb)
fast_bandwidth_kb = min_fast_kb;
if (fast_bandwidth_kb > (uint32_t)max_fast_kb)
fast_bandwidth_kb = max_fast_kb;
}
/* Protect sufficiently fast nodes from being pushed out of the set
* of Fast nodes. */
if (options->AuthDirFastGuarantee &&
fast_bandwidth_kb > options->AuthDirFastGuarantee/1000)
fast_bandwidth_kb = (uint32_t)options->AuthDirFastGuarantee/1000;
/* Now that we have a time-known that 7/8 routers are known longer than,
* fill wfus with the wfu of every such "familiar" router. */
n_familiar = 0;
SMARTLIST_FOREACH_BEGIN(nodelist, node_t *, node) {
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);
if (tk < guard_tk)
continue;
wfus[n_familiar++] = rep_hist_get_weighted_fractional_uptime(id, now);
}
} SMARTLIST_FOREACH_END(node);
if (n_familiar)
guard_wfu = median_double(wfus, n_familiar);
if (guard_wfu > WFU_TO_GUARANTEE_GUARD)
guard_wfu = WFU_TO_GUARANTEE_GUARD;
enough_mtbf_info = rep_hist_have_measured_enough_stability();
if (n_active_nonexit) {
guard_bandwidth_excluding_exits_kb =
find_nth_uint32(bandwidths_excluding_exits_kb,
n_active_nonexit, n_active_nonexit*3/4);
}
log_info(LD_DIRSERV,
"Cutoffs: For Stable, %lu sec uptime, %lu sec MTBF. "
"For Fast: %lu kilobytes/sec. "
"For Guard: WFU %.03f%%, time-known %lu sec, "
"and bandwidth %lu or %lu kilobytes/sec. "
"We%s have enough stability data.",
(unsigned long)stable_uptime,
(unsigned long)stable_mtbf,
(unsigned long)fast_bandwidth_kb,
guard_wfu*100,
(unsigned long)guard_tk,
(unsigned long)guard_bandwidth_including_exits_kb,
(unsigned long)guard_bandwidth_excluding_exits_kb,
enough_mtbf_info ? "" : " don't");
tor_free(uptimes);
tor_free(mtbfs);
tor_free(bandwidths_kb);
tor_free(bandwidths_excluding_exits_kb);
tor_free(tks);
tor_free(wfus);
}
