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Update functions that load and write the guard state file.

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Co-authored-by: Florentin Rochet <florentin.rochet@uclouvain.be>
This commit is contained in:
George Kadianakis 2020-06-11 13:49:13 +03:00
parent d2c3b6ea1e
commit 714e235a3c
2 changed files with 59 additions and 12 deletions
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68
src/feature/client/entrynodes.c
View File

@ -2812,10 +2812,12 @@ entry_guards_update_all(guard_selection_t *gs)
/**
* Return a newly allocated string for encoding the persistent parts of
* <b>guard</b> to the state file.
* <b>guard</b> to the state file. <b>dense_sampled_idx</b> refers to the
* sampled_idx made dense for this <b>guard</b>. Encoding all guards should
* lead to a dense array of sampled_idx in the state file.
*/
STATIC char *
entry_guard_encode_for_state(entry_guard_t *guard)
entry_guard_encode_for_state(entry_guard_t *guard, int dense_sampled_idx)
{
/*
* The meta-format we use is K=V K=V K=V... where K can be any
@ -2844,7 +2846,8 @@ entry_guard_encode_for_state(entry_guard_t *guard)
format_iso_time_nospace(tbuf, guard->sampled_on_date);
smartlist_add_asprintf(result, "sampled_on=%s", tbuf);
// Replacing the sampled_idx by dense array
smartlist_add_asprintf(result, "sampled_idx=%d", dense_sampled_idx);
if (guard->sampled_by_version) {
smartlist_add_asprintf(result, "sampled_by=%s",
guard->sampled_by_version);
@ -2900,11 +2903,12 @@ entry_guard_encode_for_state(entry_guard_t *guard)
}
/**
* Extract key=val from the state string <b>s</s> and duplicate the value to
* Extract key=val from the state string <b>s</b> and duplicate the value to
* some string target declared in entry_guard_parse_from_state
*/
static void parse_from_state_set_vals(const char *s, smartlist_t *entries,
smartlist_t *extra, strmap_t *vals)
static void
parse_from_state_set_vals(const char *s, smartlist_t *entries, smartlist_t
*extra, strmap_t *vals)
{
smartlist_split_string(entries, s, " ",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
@ -2933,8 +2937,9 @@ static void parse_from_state_set_vals(const char *s, smartlist_t *entries,
/**
* Handle part of the parsing state file logic, focused on time related things
*/
static void parse_from_state_handle_time(entry_guard_t *guard, char *sampled_on,
char *unlisted_since, char *confirmed_on)
static void
parse_from_state_handle_time(entry_guard_t *guard, char *sampled_on, char
*unlisted_since, char *confirmed_on)
{
#define HANDLE_TIME(field) do { \
if (field) { \
@ -2985,6 +2990,7 @@ entry_guard_parse_from_state(const char *s)
char *rsa_id = NULL;
char *nickname = NULL;
char *sampled_on = NULL;
char *sampled_idx = NULL;
char *sampled_by = NULL;
char *unlisted_since = NULL;
char *listed = NULL;
@ -3001,6 +3007,7 @@ entry_guard_parse_from_state(const char *s)
char *pb_collapsed_circuits = NULL;
char *pb_unusable_circuits = NULL;
char *pb_timeouts = NULL;
int invalid_sampled_idx = get_max_sample_size_absolute();
/* Split up the entries. Put the ones we know about in strings and the
* rest in "extra". */
@ -3014,6 +3021,7 @@ entry_guard_parse_from_state(const char *s)
FIELD(rsa_id);
FIELD(nickname);
FIELD(sampled_on);
FIELD(sampled_idx);
FIELD(sampled_by);
FIELD(unlisted_since);
FIELD(listed);
@ -3078,12 +3086,12 @@ entry_guard_parse_from_state(const char *s)
}
/* Process the various time fields. */
parse_from_state_handle_time(guard, sampled_on, unlisted_since, confirmed_on);
parse_from_state_handle_time(guard, sampled_on, unlisted_since,
confirmed_on);
/* Take sampled_by_version verbatim. */
guard->sampled_by_version = sampled_by;
sampled_by = NULL; /* prevent free */
/* Listed is a boolean */
if (listed && strcmp(listed, "0"))
guard->currently_listed = 1;
@ -3101,6 +3109,29 @@ entry_guard_parse_from_state(const char *s)
}
}
if (sampled_idx) {
int ok = 1;
long idx = tor_parse_long(sampled_idx, 10, 0, INT_MAX, &ok, NULL);
if (!ok) {
log_warn(LD_GUARD, "Guard has invalid sampled_idx %s",
escaped(sampled_idx));
/* set it to a idx higher than the max sample size */
guard->sampled_idx = invalid_sampled_idx++;
} else {
guard->sampled_idx = (int)idx;
}
} else if (confirmed_idx) {
/* This state has been written by an older Tor version which did not have
* sample ordering */
guard->sampled_idx = guard->confirmed_idx;
} else {
log_warn(LD_GUARD, "The state file seems to be into a status that could"
" yield to weird entry node selection: we're missing both a"
" sampled_idx and a confirmed_idx.");
guard->sampled_idx = invalid_sampled_idx++;
}
/* Anything we didn't recognize gets crammed together */
if (smartlist_len(extra) > 0) {
guard->extra_state_fields = smartlist_join_strings(extra, " ", 0, NULL);
@ -3155,6 +3186,7 @@ entry_guard_parse_from_state(const char *s)
tor_free(listed);
tor_free(confirmed_on);
tor_free(confirmed_idx);
tor_free(sampled_idx);
tor_free(bridge_addr);
tor_free(pb_use_attempts);
tor_free(pb_use_successes);
@ -3184,13 +3216,15 @@ entry_guards_update_guards_in_state(or_state_t *state)
config_line_t **nextline = &lines;
SMARTLIST_FOREACH_BEGIN(guard_contexts, guard_selection_t *, gs) {
int i = 0;
SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) {
if (guard->is_persistent == 0)
continue;
*nextline = tor_malloc_zero(sizeof(config_line_t));
(*nextline)->key = tor_strdup("Guard");
(*nextline)->value = entry_guard_encode_for_state(guard);
(*nextline)->value = entry_guard_encode_for_state(guard, i);
nextline = &(*nextline)->next;
i++;
} SMARTLIST_FOREACH_END(guard);
} SMARTLIST_FOREACH_END(gs);
@ -3243,6 +3277,14 @@ entry_guards_load_guards_from_state(or_state_t *state, int set)
tor_assert(gs);
smartlist_add(gs->sampled_entry_guards, guard);
guard->in_selection = gs;
/* Recompute the next_sampled_id from the state. We do not assume that
* sampled guards appear in the correct order within the file, and we
* need to know what would be the next sampled idx to give to any
* new sampled guard (i.e., max of guard->sampled_idx + 1)*/
if (gs->next_sampled_idx <= guard->sampled_idx) {
gs->next_sampled_idx = guard->sampled_idx + 1;
}
} else {
entry_guard_free(guard);
}
@ -3250,6 +3292,10 @@ entry_guards_load_guards_from_state(or_state_t *state, int set)
if (set) {
SMARTLIST_FOREACH_BEGIN(guard_contexts, guard_selection_t *, gs) {
/** Guards should be in sample order within the file, but it is maybe
* better NOT to assume that. Let's order them before updating lists
*/
smartlist_sort(gs->sampled_entry_guards, compare_guards_by_sampled_idx);
entry_guards_update_all(gs);
} SMARTLIST_FOREACH_END(gs);
}

3
src/feature/client/entrynodes.h
View File

@ -529,7 +529,8 @@ MOCK_DECL(STATIC circuit_guard_state_t *,
STATIC entry_guard_t *entry_guard_add_to_sample(guard_selection_t *gs,
const node_t *node);
STATIC entry_guard_t *entry_guards_expand_sample(guard_selection_t *gs);
STATIC char *entry_guard_encode_for_state(entry_guard_t *guard);
STATIC char *entry_guard_encode_for_state(entry_guard_t *guard, int
dense_sampled_index);
STATIC entry_guard_t *entry_guard_parse_from_state(const char *s);
#define entry_guard_free(e) \
FREE_AND_NULL(entry_guard_t, entry_guard_free_, (e))