Merge branch 'asn_bug24977_final_squashed' into maint-0.3.4

This commit is contained in:
Nick Mathewson 2018-06-20 08:02:27 -04:00
commit 7b9cd5cca5
6 changed files with 76 additions and 7 deletions

5
changes/bug24977 Normal file
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@ -0,0 +1,5 @@
o Minor bugfixes (onion services):
- Recompute some consensus information after clock skews or when we
transition from a non-live consensus to a live consensus. We do this to
avoid having an outdated state which could impact next-generation onion
services. Fixes bug 24977; bugfix on 0.3.2.1-alpha.

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@ -1332,15 +1332,20 @@ hs_get_responsible_hsdirs(const ed25519_public_key_t *blinded_pk,
sorted_nodes = smartlist_new();
/* Make sure we actually have a live consensus */
networkstatus_t *c = networkstatus_get_live_consensus(approx_time());
if (!c || smartlist_len(c->routerstatus_list) == 0) {
log_warn(LD_REND, "No live consensus so we can't get the responsible "
"hidden service directories.");
goto done;
}
/* Ensure the nodelist is fresh, since it contains the HSDir indices. */
nodelist_ensure_freshness(c);
/* Add every node_t that support HSDir v3 for which we do have a valid
* hsdir_index already computed for them for this consensus. */
{
networkstatus_t *c = networkstatus_get_latest_consensus();
if (!c || smartlist_len(c->routerstatus_list) == 0) {
log_warn(LD_REND, "No valid consensus so we can't get the responsible "
"hidden service directories.");
goto done;
}
SMARTLIST_FOREACH_BEGIN(c->routerstatus_list, const routerstatus_t *, rs) {
/* Even though this node_t object won't be modified and should be const,
* we can't add const object in a smartlist_t. */

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@ -113,6 +113,11 @@ typedef struct nodelist_t {
/* Set of addresses that belong to nodes we believe in. */
address_set_t *node_addrs;
/* The valid-after time of the last live consensus that initialized the
* nodelist. We use this to detect outdated nodelists that need to be
* rebuilt using a newer consensus. */
time_t live_consensus_valid_after;
} nodelist_t;
static inline unsigned int
@ -630,6 +635,12 @@ nodelist_set_consensus(networkstatus_t *ns)
}
} SMARTLIST_FOREACH_END(node);
}
/* If the consensus is live, note down the consensus valid-after that formed
* the nodelist. */
if (networkstatus_is_live(ns, approx_time())) {
the_nodelist->live_consensus_valid_after = ns->valid_after;
}
}
/** Helper: return true iff a node has a usable amount of information*/
@ -854,6 +865,25 @@ nodelist_assert_ok(void)
digestmap_free(dm, NULL);
}
/** Ensure that the nodelist has been created with the most recent consensus.
* If that's not the case, make it so. */
void
nodelist_ensure_freshness(networkstatus_t *ns)
{
tor_assert(ns);
/* We don't even have a nodelist: this is a NOP. */
if (!the_nodelist) {
return;
}
if (the_nodelist->live_consensus_valid_after != ns->valid_after) {
log_info(LD_GENERAL, "Nodelist was not fresh: rebuilding. (%d / %d)",
(int) the_nodelist->live_consensus_valid_after,
(int) ns->valid_after);
nodelist_set_consensus(ns);
}
}
/** Return a list of a node_t * for every node we know about. The caller
* MUST NOT modify the list. (You can set and clear flags in the nodes if
* you must, but you must not add or remove nodes.) */

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@ -29,6 +29,7 @@ const node_t *node_get_by_hex_id(const char *identity_digest,
node_t *nodelist_set_routerinfo(routerinfo_t *ri, routerinfo_t **ri_old_out);
node_t *nodelist_add_microdesc(microdesc_t *md);
void nodelist_set_consensus(networkstatus_t *ns);
void nodelist_ensure_freshness(networkstatus_t *ns);
int nodelist_probably_contains_address(const tor_addr_t *addr);
void nodelist_remove_microdesc(const char *identity_digest, microdesc_t *md);

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@ -83,6 +83,10 @@ get_voting_schedule(const or_options_t *options, time_t now, int severity)
interval = (int)( consensus->fresh_until - consensus->valid_after );
vote_delay = consensus->vote_seconds;
dist_delay = consensus->dist_seconds;
/* Note down the consensus valid after, so that we detect outdated voting
* schedules in case of skewed clocks etc. */
new_voting_schedule->live_consensus_valid_after = consensus->valid_after;
} else {
interval = options->TestingV3AuthInitialVotingInterval;
vote_delay = options->TestingV3AuthInitialVoteDelay;
@ -138,14 +142,34 @@ voting_schedule_t voting_schedule;
time_t
voting_schedule_get_next_valid_after_time(void)
{
time_t now = approx_time();
bool need_to_recalculate_voting_schedule = false;
/* This is a safe guard in order to make sure that the voting schedule
* static object is at least initialized. Using this function with a zeroed
* voting schedule can lead to bugs. */
if (tor_mem_is_zero((const char *) &voting_schedule,
sizeof(voting_schedule))) {
voting_schedule_recalculate_timing(get_options(), time(NULL));
need_to_recalculate_voting_schedule = true;
goto done; /* no need for next check if we have to recalculate anyway */
}
/* Also make sure we are not using an outdated voting schedule. If we have a
* newer consensus, make sure we recalculate the voting schedule. */
const networkstatus_t *ns = networkstatus_get_live_consensus(now);
if (ns && ns->valid_after != voting_schedule.live_consensus_valid_after) {
log_info(LD_DIR, "Voting schedule is outdated: recalculating (%d/%d)",
(int) ns->valid_after,
(int) voting_schedule.live_consensus_valid_after);
need_to_recalculate_voting_schedule = true;
}
done:
if (need_to_recalculate_voting_schedule) {
voting_schedule_recalculate_timing(get_options(), now);
voting_schedule.created_on_demand = 1;
}
return voting_schedule.interval_starts;
}

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@ -43,6 +43,10 @@ typedef struct {
* timings only for the first vote even though this object was initilized
* prior to voting. */
int created_on_demand;
/** The valid-after time of the last live consensus that filled this voting
* schedule. It's used to detect outdated voting schedules. */
time_t live_consensus_valid_after;
} voting_schedule_t;
/* Public API. */