diff --git a/src/or/config.c b/src/or/config.c
index f77f4d1879..b7b5cff35a 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -1561,6 +1561,36 @@ options_transition_requires_fresh_tls_context(const or_options_t *old_options,
return 0;
}
+/**
+ * Return true if changing the configuration from old to new
+ * affects the guard susbsystem.
+ */
+static int
+options_transition_affects_guards(const or_options_t *old,
+ const or_options_t *new)
+{
+ /* NOTE: Make sure this function stays in sync with
+ * entry_guards_set_filtered_flags */
+
+ tor_assert(old);
+ tor_assert(new);
+
+ return
+ (old->UseEntryGuards != new->UseEntryGuards ||
+ old->UseDeprecatedGuardAlgorithm != new->UseDeprecatedGuardAlgorithm ||
+ old->UseBridges != new->UseBridges ||
+ old->UseEntryGuards != new->UseEntryGuards ||
+ old->ClientUseIPv4 != new->ClientUseIPv4 ||
+ old->ClientUseIPv6 != new->ClientUseIPv6 ||
+ old->FascistFirewall != new->FascistFirewall ||
+ !routerset_equal(old->ExcludeNodes, new->ExcludeNodes) ||
+ !routerset_equal(old->EntryNodes, new->EntryNodes) ||
+ !smartlist_strings_eq(old->FirewallPorts, new->FirewallPorts) ||
+ !config_lines_eq(old->Bridges, new->Bridges) ||
+ !config_lines_eq(old->ReachableORAddresses, new->ReachableORAddresses) ||
+ !config_lines_eq(old->ReachableDirAddresses, new->ReachableDirAddresses));
+}
+
/** Fetch the active option list, and take actions based on it. All of the
* things we do should survive being done repeatedly. If present,
* old_options contains the previous value of the options.
@@ -1580,6 +1610,8 @@ options_act(const or_options_t *old_options)
const int transition_affects_workers =
old_options && options_transition_affects_workers(old_options, options);
int old_ewma_enabled;
+ const int transition_affects_guards =
+ old_options && options_transition_affects_guards(old_options, options);
/* disable ptrace and later, other basic debugging techniques */
{
@@ -1875,6 +1907,7 @@ options_act(const or_options_t *old_options)
if (old_options) {
int revise_trackexithosts = 0;
int revise_automap_entries = 0;
+ int abandon_circuits = 0;
if ((options->UseEntryGuards && !old_options->UseEntryGuards) ||
options->UseBridges != old_options->UseBridges ||
(options->UseBridges &&
@@ -1891,6 +1924,16 @@ options_act(const or_options_t *old_options)
"Changed to using entry guards or bridges, or changed "
"preferred or excluded node lists. "
"Abandoning previous circuits.");
+ abandon_circuits = 1;
+ }
+
+ if (transition_affects_guards) {
+ if (guards_update_all()) {
+ abandon_circuits = 1;
+ }
+ }
+
+ if (abandon_circuits) {
circuit_mark_all_unused_circs();
circuit_mark_all_dirty_circs_as_unusable();
revise_trackexithosts = 1;
diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c
index 81751f565c..9a753e6d25 100644
--- a/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@ -91,7 +91,7 @@
*
* [x] Whenever we get a new consensus, call update_from_consensus(). (LATER.)
*
- * [ ] Whenever the configuration changes in a relevant way, update the
+ * [x] Whenever the configuration changes in a relevant way, update the
* filtered/usable flags. (LATER.)
*
* [x] Whenever we add a guard to the sample, make sure its filtered/usable
@@ -696,6 +696,9 @@ static int
node_passes_guard_filter(const or_options_t *options, guard_selection_t *gs,
const node_t *node)
{
+ /* NOTE: Make sure that this function stays in sync with
+ * options_transition_affects_entry_guards */
+
(void)gs;
if (routerset_contains_node(options->ExcludeNodes, node))
return 0;
@@ -1636,14 +1639,16 @@ entry_guards_upgrade_waiting_circuits(guard_selection_t *gs,
/**
* Update all derived pieces of the guard selection state in gs.
+ * Return true iff we should stop using all previously generated circuits.
*/
-void
+int
entry_guards_update_all(guard_selection_t *gs)
{
sampled_guards_update_from_consensus(gs);
entry_guards_update_filtered_sets(gs);
entry_guards_update_confirmed(gs);
entry_guards_update_primary(gs);
+ return 0;
}
/**
@@ -4020,14 +4025,16 @@ entries_retry_all(const or_options_t *options)
}
/** Helper: Update the status of all entry guards, in whatever algorithm
- is used. */
-void
+ * is used. Return true if we should stop using all previously generated
+ * circuits. */
+int
guards_update_all(void)
{
if (get_options()->UseDeprecatedGuardAlgorithm) {
entry_guards_compute_status(get_options(), approx_time());
+ return 0;
} else {
- entry_guards_update_all(get_guard_selection_info());
+ return entry_guards_update_all(get_guard_selection_info());
}
}
diff --git a/src/or/entrynodes.h b/src/or/entrynodes.h
index d8468eb287..4cbfbf55bf 100644
--- a/src/or/entrynodes.h
+++ b/src/or/entrynodes.h
@@ -294,7 +294,7 @@ struct circuit_guard_state_t {
#endif
/* Common entry points for old and new guard code */
-void guards_update_all(void);
+int guards_update_all(void);
const node_t *guards_choose_guard(cpath_build_state_t *state,
circuit_guard_state_t **guard_state_out);
const node_t *guards_choose_dirguard(dirinfo_type_t info,
@@ -336,7 +336,7 @@ void entry_guard_cancel(guard_selection_t *gs,
circuit_guard_state_t **guard_state_p);
void entry_guard_chan_failed(guard_selection_t *gs,
channel_t *chan);
-void entry_guards_update_all(guard_selection_t *gs);
+int entry_guards_update_all(guard_selection_t *gs);
int entry_guards_upgrade_waiting_circuits(guard_selection_t *gs,
const smartlist_t *all_circuits,
smartlist_t *newly_complete_out);
diff --git a/src/or/main.c b/src/or/main.c
index 65d1c1fd79..16106612a9 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -979,7 +979,10 @@ directory_info_has_arrived(time_t now, int from_cache, int suppress_logs)
/* if we have enough dir info, then update our guard status with
* whatever we just learned. */
- guards_update_all();
+ int invalidate_circs = guards_update_all();
+ // This shouldn't be able to occur at this point.
+ tor_assert_nonfatal(! invalidate_circs);
+
/* Don't even bother trying to get extrainfo until the rest of our
* directory info is up-to-date */
if (options->DownloadExtraInfo)