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Make new prop271 entry guards persistent

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To do this, it makes sense to treat legacy guards as a separate
guard_selection_t *, and handle them separately.  This also means we
add support here for having multiple guard selections.

Note that we don't persist pathbias information yet; that will take
some refactoring.
This commit is contained in:
Nick Mathewson 2016-11-22 14:22:54 -05:00
parent dbbaa51518
commit 858c8f5593
5 changed files with 218 additions and 39 deletions
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186
src/or/entrynodes.c
View File

@ -179,14 +179,16 @@ should_apply_guardfraction(const networkstatus_t *ns)
return options->UseGuardFraction;
}
/** Allocate and return a new guard_selection_t */
/**
* Allocate and return a new guard_selection_t, with the name <b>name</b>.
*/
STATIC guard_selection_t *
guard_selection_new(void)
guard_selection_new(const char *name)
{
guard_selection_t *gs;
gs = tor_malloc_zero(sizeof(*gs));
gs->name = tor_strdup(name);
gs->chosen_entry_guards = smartlist_new();
gs->sampled_entry_guards = smartlist_new();
gs->confirmed_entry_guards = smartlist_new();
@ -195,6 +197,37 @@ guard_selection_new(void)
return gs;
}
/**
* Return the guard selection called <b>name</b>. If there is none, and
* <b>create_if_absent</b> is true, then create and return it. If there
* is none, and <b>create_if_absent</b> is false, then return NULL.
*/
static guard_selection_t *
get_guard_selection_by_name(const char *name, int create_if_absent)
{
if (!guard_contexts) {
guard_contexts = smartlist_new();
}
SMARTLIST_FOREACH_BEGIN(guard_contexts, guard_selection_t *, gs) {
if (!strcmp(gs->name, name))
return gs;
} SMARTLIST_FOREACH_END(gs);
if (! create_if_absent)
return NULL;
guard_selection_t *new_selection = guard_selection_new(name);
smartlist_add(guard_contexts, new_selection);
const char *default_name = get_options()->UseDeprecatedGuardAlgorithm ?
"legacy" : "default";
if (!strcmp(name, default_name))
curr_guard_context = new_selection;
return new_selection;
}
/** Get current default guard_selection_t, creating it if necessary */
guard_selection_t *
get_guard_selection_info(void)
@ -204,7 +237,9 @@ get_guard_selection_info(void)
}
if (!curr_guard_context) {
curr_guard_context = guard_selection_new();
const char *name = get_options()->UseDeprecatedGuardAlgorithm ?
"legacy" : "default";
curr_guard_context = guard_selection_new(name);
smartlist_add(guard_contexts, curr_guard_context);
}
@ -355,6 +390,7 @@ entry_guard_add_to_sample(guard_selection_t *gs,
entry_guard_t *guard = tor_malloc_zero(sizeof(entry_guard_t));
/* persistent fields */
guard->selection_name = tor_strdup(gs->name);
memcpy(guard->identity, node->identity, DIGEST_LEN);
strlcpy(guard->nickname, node_get_nickname(node), sizeof(guard->nickname));
guard->sampled_on_date = randomize_time(approx_time(), GUARD_LIFETIME/10);
@ -691,8 +727,9 @@ entry_guard_passes_filter(const or_options_t *options, guard_selection_t *gs,
return 0;
const node_t *node = node_get_by_id(guard->identity);
if (BUG(node == NULL)) {
// should be impossible, since currently_listed was true.
if (node == NULL) {
// This can happen when currently_listed is true, and we're not updating
// it because we don't have a live consensus.
return 0;
}
@ -1627,6 +1664,7 @@ entry_guard_encode_for_state(entry_guard_t *guard)
tor_assert(guard);
smartlist_add_asprintf(result, "in=%s", guard->selection_name);
smartlist_add_asprintf(result, "rsa_id=%s",
hex_str(guard->identity, DIGEST_LEN));
if (strlen(guard->nickname)) {
@ -1678,6 +1716,7 @@ entry_guard_parse_from_state(const char *s)
smartlist_t *extra = smartlist_new();
/* These fields get parsed from the string. */
char *in = NULL;
char *rsa_id = NULL;
char *nickname = NULL;
char *sampled_on = NULL;
@ -1693,6 +1732,7 @@ entry_guard_parse_from_state(const char *s)
smartlist_t *entries = smartlist_new();
strmap_t *vals = strmap_new(); // Maps keyword to location
strmap_set(vals, "in", &in);
strmap_set(vals, "rsa_id", &rsa_id);
strmap_set(vals, "nickname", &nickname);
strmap_set(vals, "sampled_on", &sampled_on);
@ -1731,6 +1771,14 @@ entry_guard_parse_from_state(const char *s)
entry_guard_t *guard = tor_malloc_zero(sizeof(entry_guard_t));
if (in == NULL) {
log_warn(LD_CIRC, "Guard missing 'in' field");
goto err;
}
guard->selection_name = in;
in = NULL;
if (rsa_id == NULL) {
log_warn(LD_CIRC, "Guard missing RSA ID field");
goto err;
@ -1825,6 +1873,7 @@ entry_guard_parse_from_state(const char *s)
guard = NULL;
done:
tor_free(in);
tor_free(rsa_id);
tor_free(nickname);
tor_free(sampled_on);
@ -1839,16 +1888,95 @@ entry_guard_parse_from_state(const char *s)
return guard;
}
/* XXXXprop271 This is a dummy function added for now so that all of the
* new guard code will be counted as reachable. It should get removed.
/**
* Replace the Guards entries in <b>state</b> with a list of all our
* non-legacy sampled guards.
*/
__attribute__((noreturn)) void
entry_guards_DUMMY_ENTRY_POINT(void)
static void
entry_guards_update_guards_in_state(or_state_t *state)
{
// prop271 XXXXX kludge; remove this
entry_guard_encode_for_state(NULL);
entry_guard_parse_from_state(NULL);
tor_assert(0);
if (!guard_contexts)
return;
config_line_t *lines = NULL;
config_line_t **nextline = &lines;
SMARTLIST_FOREACH_BEGIN(guard_contexts, guard_selection_t *, gs) {
if (!strcmp(gs->name, "legacy"))
continue; /* This is encoded differently. */
SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) {
*nextline = tor_malloc_zero(sizeof(config_line_t));
(*nextline)->key = tor_strdup("Guard");
(*nextline)->value = entry_guard_encode_for_state(guard);
nextline = &(*nextline)->next;
} SMARTLIST_FOREACH_END(guard);
gs->dirty = 0;
} SMARTLIST_FOREACH_END(gs);
/* XXXXX prop271 circuitpathbias */
config_free_lines(state->Guard);
state->Guard = lines;
}
/**
* Replace our non-legacy sampled guards from the Guards entries in
* <b>state</b>. Return 0 on success, -1 on failure. (If <b>set</b> is
* true, replace nothing -- only check whether replacing would work.)
*/
static int
entry_guards_load_guards_from_state(or_state_t *state, int set)
{
/* XXXXX prop271 circuitpathbias */
const config_line_t *line = state->Guard;
int n_errors = 0;
if (!guard_contexts)
guard_contexts = smartlist_new();
/* Wipe all our existing guard info. (we shouldn't have any, but
* let's be safe.) */
if (set) {
SMARTLIST_FOREACH_BEGIN(guard_contexts, guard_selection_t *, gs) {
if (!strcmp(gs->name, "legacy"))
continue;
guard_selection_free(gs);
if (curr_guard_context == gs)
curr_guard_context = NULL;
SMARTLIST_DEL_CURRENT(guard_contexts, gs);
} SMARTLIST_FOREACH_END(gs);
}
for ( ; line != NULL; line = line->next) {
entry_guard_t *guard = entry_guard_parse_from_state(line->value);
if (guard == NULL) {
++n_errors;
continue;
}
tor_assert(guard->selection_name);
if (!strcmp(guard->selection_name, "legacy")) {
++n_errors;
entry_guard_free(guard);
continue;
}
if (set) {
guard_selection_t *gs;
gs = get_guard_selection_by_name(guard->selection_name, 1);
tor_assert(gs);
smartlist_add(gs->sampled_entry_guards, guard);
} else {
entry_guard_free(guard);
}
}
if (set) {
SMARTLIST_FOREACH_BEGIN(guard_contexts, guard_selection_t *, gs) {
if (!strcmp(gs->name, "legacy"))
continue;
entry_guards_update_all(gs);
} SMARTLIST_FOREACH_END(gs);
}
return n_errors ? -1 : 0;
}
/* XXXXX ----------------------------------------------- */
@ -2403,6 +2531,7 @@ entry_guard_free(entry_guard_t *e)
tor_free(e->chosen_by_version);
tor_free(e->sampled_by_version);
tor_free(e->extra_state_fields);
tor_free(e->selection_name);
tor_free(e);
}
@ -3436,9 +3565,19 @@ entry_guards_parse_state_for_guard_selection(
int
entry_guards_parse_state(or_state_t *state, int set, char **msg)
{
return entry_guards_parse_state_for_guard_selection(
get_guard_selection_info(),
int r1 = entry_guards_load_guards_from_state(state, set);
int r2 = entry_guards_parse_state_for_guard_selection(
get_guard_selection_by_name("legacy", 1),
state, set, msg);
if (r1 < 0 || r2 < 0) {
if (msg && *msg == NULL) {
*msg = tor_strdup("parsing error"); //xxxx prop271 should we try harder?
}
return -1;
}
return 0;
}
/** How long will we let a change in our guard nodes stay un-saved
@ -3466,7 +3605,9 @@ entry_guards_changed_for_guard_selection(guard_selection_t *gs)
else
when = time(NULL) + FAST_GUARD_STATE_FLUSH_TIME;
/* or_state_save() will call entry_guards_update_state(). */
/* or_state_save() will call entry_guards_update_state() and
entry_guards_update_guards_in_state()
*/
or_state_mark_dirty(get_or_state(), when);
}
@ -3494,11 +3635,14 @@ void
entry_guards_update_state(or_state_t *state)
{
config_line_t **next, *line;
guard_selection_t *gs = get_guard_selection_info();
tor_assert(gs != NULL);
// Handles all non-legacy guard info.
entry_guards_update_guards_in_state(state);
guard_selection_t *gs = get_guard_selection_by_name("legacy", 0);
if (!gs)
return; // nothign to save.
tor_assert(gs->chosen_entry_guards != NULL);
if (!gs->dirty)
return;
@ -3835,6 +3979,8 @@ guard_selection_free(guard_selection_t *gs)
{
if (!gs) return;
tor_free(gs->name);
if (gs->chosen_entry_guards) {
SMARTLIST_FOREACH(gs->chosen_entry_guards, entry_guard_t *, e,
entry_guard_free(e));

14
src/or/entrynodes.h
View File

@ -121,6 +121,11 @@ struct entry_guard_t {
* item should occur in the CONFIRMED_GUARDS ordered
* list */
/**
* Which selection does this guard belong to?
*/
char *selection_name;
/* ==== Non-persistent fields. */
/* == These are used by sampled guards */
/** When did we last decide to try using this guard for a circuit? 0 for
@ -202,6 +207,11 @@ struct entry_guard_t {
* about guard selection algorithms.
*/
struct guard_selection_s {
/**
* The name for this guard-selection object. (Must not contain spaces).
*/
char *name;
/**
* A value of 1 means that guard_selection_t structures have changed
* and those changes need to be flushed to disk.
@ -398,7 +408,7 @@ int num_bridges_usable(void);
// ---------- XXXX these functions and definitions are post-prop271.
HANDLE_DECL(entry_guard, entry_guard_t, STATIC)
STATIC guard_selection_t *guard_selection_new(void);
STATIC guard_selection_t *guard_selection_new(const char *name);
STATIC void guard_selection_free(guard_selection_t *gs);
STATIC entry_guard_t *get_sampled_guard_with_id(guard_selection_t *gs,
const uint8_t *rsa_id);
@ -459,8 +469,6 @@ STATIC unsigned entry_guards_note_guard_success(guard_selection_t *gs,
unsigned old_state);
STATIC int entry_guard_has_higher_priority(entry_guard_t *a, entry_guard_t *b);
void entry_guards_DUMMY_ENTRY_POINT(void);
// ---------- XXXX this stuff is pre-prop271.
STATIC const node_t *add_an_entry_guard(guard_selection_t *gs,

5
src/or/or.h
View File

@ -4618,9 +4618,12 @@ typedef struct {
uint64_t AccountingBytesAtSoftLimit;
uint64_t AccountingExpectedUsage;
/** A list of Entry Guard-related configuration lines. */
/** A list of Entry Guard-related configuration lines. (pre-prop271) */
config_line_t *EntryGuards;
/** A list of guard-related configuration lines. (post-prop271) */
config_line_t *Guard;
config_line_t *TransportProxies;
/** These fields hold information on the history of bandwidth usage for

2
src/or/statefile.c
View File

@ -102,6 +102,8 @@ static config_var_t state_vars_[] = {
V(BWHistoryDirWriteValues, CSV, ""),
V(BWHistoryDirWriteMaxima, CSV, ""),
V(Guard, LINELIST, NULL),
V(TorVersion, STRING, NULL),
V(LastRotatedOnionKey, ISOTIME, NULL),

50
src/test/test_entrynodes.c
View File

@ -528,6 +528,8 @@ state_lines_free(smartlist_t *entry_guard_lines)
static void
test_entry_guards_parse_state_simple(void *arg)
{
or_options_t *options = get_options_mutable();
options->UseDeprecatedGuardAlgorithm = 1;
or_state_t *state = or_state_new();
const smartlist_t *all_entry_guards = get_entry_guards();
smartlist_t *entry_state_lines = smartlist_new();
@ -622,6 +624,8 @@ test_entry_guards_parse_state_simple(void *arg)
static void
test_entry_guards_parse_state_pathbias(void *arg)
{
or_options_t *options = get_options_mutable();
options->UseDeprecatedGuardAlgorithm = 1;
or_state_t *state = or_state_new();
const smartlist_t *all_entry_guards = get_entry_guards();
char *msg = NULL;
@ -1021,6 +1025,7 @@ test_entry_guard_encode_for_state_minimal(void *arg)
(void) arg;
entry_guard_t *eg = tor_malloc_zero(sizeof(entry_guard_t));
eg->selection_name = tor_strdup("wubwub");
memcpy(eg->identity, "plurpyflurpyslurpydo", DIGEST_LEN);
eg->sampled_on_date = 1479081600;
eg->confirmed_idx = -1;
@ -1029,6 +1034,7 @@ test_entry_guard_encode_for_state_minimal(void *arg)
s = entry_guard_encode_for_state(eg);
tt_str_op(s, OP_EQ,
"in=wubwub "
"rsa_id=706C75727079666C75727079736C75727079646F "
"sampled_on=2016-11-14T00:00:00 "
"listed=0");
@ -1045,6 +1051,7 @@ test_entry_guard_encode_for_state_maximal(void *arg)
entry_guard_t *eg = tor_malloc_zero(sizeof(entry_guard_t));
strlcpy(eg->nickname, "Fred", sizeof(eg->nickname));
eg->selection_name = tor_strdup("default");
memcpy(eg->identity, "plurpyflurpyslurpydo", DIGEST_LEN);
eg->sampled_on_date = 1479081600;
eg->sampled_by_version = tor_strdup("1.2.3");
@ -1058,6 +1065,7 @@ test_entry_guard_encode_for_state_maximal(void *arg)
s = entry_guard_encode_for_state(eg);
tt_str_op(s, OP_EQ,
"in=default "
"rsa_id=706C75727079666C75727079736C75727079646F "
"nickname=Fred "
"sampled_on=2016-11-14T00:00:00 "
@ -1082,9 +1090,11 @@ test_entry_guard_parse_from_state_minimal(void *arg)
time_t t = approx_time();
eg = entry_guard_parse_from_state(
"in=default_plus "
"rsa_id=596f75206d6179206e656564206120686f626279");
tt_assert(eg);
tt_str_op(eg->selection_name, OP_EQ, "default_plus");
test_mem_op_hex(eg->identity, OP_EQ,
"596f75206d6179206e656564206120686f626279");
tt_str_op(eg->nickname, OP_EQ, "$596F75206D6179206E656564206120686F626279");
@ -1112,6 +1122,7 @@ test_entry_guard_parse_from_state_maximal(void *arg)
entry_guard_t *eg = NULL;
eg = entry_guard_parse_from_state(
"in=fred "
"rsa_id=706C75727079666C75727079736C75727079646F "
"nickname=Fred "
"sampled_on=2016-11-14T00:00:00 "
@ -1150,22 +1161,30 @@ test_entry_guard_parse_from_state_failure(void *arg)
(void)arg;
entry_guard_t *eg = NULL;
/* no selection */
eg = entry_guard_parse_from_state(
"rsa_id=596f75206d6179206e656564206120686f626270");
tt_assert(! eg);
/* no RSA ID. */
eg = entry_guard_parse_from_state("nickname=Fred");
eg = entry_guard_parse_from_state("in=default nickname=Fred");
tt_assert(! eg);
/* Bad RSA ID: bad character. */
eg = entry_guard_parse_from_state(
"in=default "
"rsa_id=596f75206d6179206e656564206120686f62627q");
tt_assert(! eg);
/* Bad RSA ID: too long.*/
eg = entry_guard_parse_from_state(
"in=default "
"rsa_id=596f75206d6179206e656564206120686f6262703");
tt_assert(! eg);
/* Bad RSA ID: too short.*/
eg = entry_guard_parse_from_state(
"in=default "
"rsa_id=596f75206d6179206e65656420612");
tt_assert(! eg);
@ -1182,6 +1201,7 @@ test_entry_guard_parse_from_state_partial_failure(void *arg)
time_t t = approx_time();
eg = entry_guard_parse_from_state(
"in=default "
"rsa_id=706C75727079666C75727079736C75727079646F "
"nickname=FredIsANodeWithAStrangeNicknameThatIsTooLong "
"sampled_on=2016-11-14T00:00:99 "
@ -1219,7 +1239,7 @@ static void
test_entry_guard_add_single_guard(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
/* 1: Add a single guard to the sample. */
node_t *n1 = smartlist_get(big_fake_net_nodes, 0);
@ -1259,7 +1279,7 @@ static void
test_entry_guard_node_filter(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
bridge_line_t *bl = NULL;
/* Initialize a bunch of node objects that are all guards. */
@ -1334,7 +1354,7 @@ static void
test_entry_guard_expand_sample(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
digestmap_t *node_by_id = digestmap_new();
entry_guard_t *guard = entry_guards_expand_sample(gs);
@ -1428,7 +1448,7 @@ static void
test_entry_guard_expand_sample_small_net(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
/* Fun corner case: not enough guards to make up our whole sample size. */
SMARTLIST_FOREACH(big_fake_net_nodes, node_t *, n, {
@ -1461,7 +1481,7 @@ test_entry_guard_update_from_consensus_status(void *arg)
(void)arg;
int i;
time_t start = approx_time();
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
networkstatus_t *ns_tmp = NULL;
/* Don't randomly backdate stuff; it will make correctness harder to check.*/
@ -1566,7 +1586,7 @@ test_entry_guard_update_from_consensus_repair(void *arg)
(void)arg;
int i;
time_t start = approx_time();
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
/* Don't randomly backdate stuff; it will make correctness harder to check.*/
MOCK(randomize_time, mock_randomize_time_no_randomization);
@ -1629,7 +1649,7 @@ test_entry_guard_update_from_consensus_remove(void *arg)
(void)arg;
//int i;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
smartlist_t *keep_ids = smartlist_new();
smartlist_t *remove_ids = smartlist_new();
@ -1727,7 +1747,7 @@ test_entry_guard_confirming_guards(void *arg)
(void)arg;
/* Now let's check the logic responsible for manipulating the list
* of confirmed guards */
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
MOCK(randomize_time, mock_randomize_time_no_randomization);
/* Create the sample. */
@ -1797,7 +1817,7 @@ static void
test_entry_guard_sample_reachable_filtered(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
entry_guards_expand_sample(gs);
const int N = 10000;
bitarray_t *selected = NULL;
@ -1867,7 +1887,7 @@ static void
test_entry_guard_sample_reachable_filtered_empty(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
/* What if we try to sample from a set of 0? */
SMARTLIST_FOREACH(big_fake_net_nodes, node_t *, n,
n->is_possible_guard = 0);
@ -1883,7 +1903,7 @@ static void
test_entry_guard_retry_unreachable(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
entry_guards_expand_sample(gs);
/* Let's say that we have two guards, and they're down.
@ -1942,7 +1962,7 @@ static void
test_entry_guard_manage_primary(void *arg)
{
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
smartlist_t *prev_guards = smartlist_new();
/* If no guards are confirmed, we should pick a few reachable guards and
@ -2015,7 +2035,7 @@ test_entry_guard_select_for_circuit_no_confirmed(void *arg)
{
/* Simpler cases: no gaurds are confirmed yet. */
(void)arg;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
/* simple starting configuration */
entry_guards_update_primary(gs);
@ -2099,7 +2119,7 @@ test_entry_guard_select_for_circuit_confirmed(void *arg)
guards, we use a confirmed guard. */
(void)arg;
int i;
guard_selection_t *gs = guard_selection_new();
guard_selection_t *gs = guard_selection_new("default");
const int N_CONFIRMED = 10;
/* slightly more complicated simple starting configuration */