Merge branch 'tor-github/pr/1943'

3 files changed, 94 insertions, 0 deletions

diff --git a/src/feature/control/control_cmd.c b/src/feature/control/control_cmd.c
index d9a38011de..ff1014632d 100644
--- a/src/feature/control/control_cmd.c
+++ b/src/feature/control/control_cmd.c
@@ -20,9 +20,11 @@
 #include "core/or/circuitlist.h"
 #include "core/or/circuituse.h"
 #include "core/or/connection_edge.h"
+#include "core/or/circuitstats.h"
 #include "feature/client/addressmap.h"
 #include "feature/client/dnsserv.h"
 #include "feature/client/entrynodes.h"
+#include "feature/control/control_events.h"
 #include "feature/control/control.h"
 #include "feature/control/control_auth.h"
 #include "feature/control/control_cmd.h"
@@ -55,6 +57,8 @@
 #include "feature/rend/rend_encoded_v2_service_descriptor_st.h"
 #include "feature/rend/rend_service_descriptor_st.h"
 
+#include "src/app/config/statefile.h"
+
 static int control_setconf_helper(control_connection_t *conn,
                                   const control_cmd_args_t *args,
                                   int use_defaults);
@@ -1396,6 +1400,34 @@ handle_control_dropguards(control_connection_t *conn,
   return 0;
 }
 
+static const control_cmd_syntax_t droptimeouts_syntax = {
+  .max_args = 0,
+};
+
+/** Implementation for the DROPTIMEOUTS command. */
+static int
+handle_control_droptimeouts(control_connection_t *conn,
+                          const control_cmd_args_t *args)
+{
+  (void) args; /* We don't take arguments. */
+
+  static int have_warned = 0;
+  if (! have_warned) {
+    log_warn(LD_CONTROL, "DROPTIMEOUTS is dangerous; make sure you understand "
+             "the risks before using it. It may be removed in a future "
+             "version of Tor.");
+    have_warned = 1;
+  }
+
+  circuit_build_times_reset(get_circuit_build_times_mutable());
+  send_control_done(conn);
+  or_state_mark_dirty(get_or_state(), 0);
+  cbt_control_event_buildtimeout_set(get_circuit_build_times(),
+                                     BUILDTIMEOUT_SET_EVENT_RESET);
+
+  return 0;
+}
+
 static const char *hsfetch_keywords[] = {
   "SERVER", NULL,
 };
@@ -2331,6 +2363,7 @@ static const control_cmd_def_t CONTROL_COMMANDS[] =
   ONE_LINE(protocolinfo, 0),
   ONE_LINE(authchallenge, CMD_FL_WIPE),
   ONE_LINE(dropguards, 0),
+  ONE_LINE(droptimeouts, 0),
   ONE_LINE(hsfetch, 0),
   MULTLINE(hspost, 0),
   ONE_LINE(add_onion, CMD_FL_WIPE),
diff --git a/src/feature/control/control_events.c b/src/feature/control/control_events.c
index 916ccea875..8e69c772f6 100644
--- a/src/feature/control/control_events.c
+++ b/src/feature/control/control_events.c
@@ -17,6 +17,7 @@
 #include "core/mainloop/mainloop.h"
 #include "core/or/channeltls.h"
 #include "core/or/circuitlist.h"
+#include "core/or/circuitstats.h"
 #include "core/or/command.h"
 #include "core/or/connection_edge.h"
 #include "core/or/connection_or.h"
@@ -141,6 +142,64 @@ clear_circ_bw_fields(void)
   SMARTLIST_FOREACH_END(circ);
 }
 
+/* Helper to emit the BUILDTIMEOUT_SET circuit build time event */
+void
+cbt_control_event_buildtimeout_set(const circuit_build_times_t *cbt,
+                                   buildtimeout_set_event_t type)
+{
+  char *args = NULL;
+  double qnt;
+  double timeout_rate = 0.0;
+  double close_rate = 0.0;
+
+  switch (type) {
+    case BUILDTIMEOUT_SET_EVENT_RESET:
+    case BUILDTIMEOUT_SET_EVENT_SUSPENDED:
+    case BUILDTIMEOUT_SET_EVENT_DISCARD:
+      qnt = 1.0;
+      break;
+    case BUILDTIMEOUT_SET_EVENT_COMPUTED:
+    case BUILDTIMEOUT_SET_EVENT_RESUME:
+    default:
+      qnt = circuit_build_times_quantile_cutoff();
+      break;
+  }
+
+  /* The timeout rate is the ratio of the timeout count over
+   * the total number of circuits attempted. The total number of
+   * circuits is (timeouts+succeeded), since every circuit
+   * either succeeds, or times out. "Closed" circuits are
+   * MEASURE_TIMEOUT circuits whose measurement period expired.
+   * All MEASURE_TIMEOUT circuits are counted in the timeouts stat
+   * before transitioning to MEASURE_TIMEOUT (in
+   * circuit_build_times_mark_circ_as_measurement_only()).
+   * MEASURE_TIMEOUT circuits that succeed are *not* counted as
+   * "succeeded". See circuit_build_times_handle_completed_hop().
+   *
+   * We cast the denominator
+   * to promote it to double before the addition, to avoid int32
+   * overflow. */
+  const double total_circuits =
+    ((double)cbt->num_circ_timeouts) + cbt->num_circ_succeeded;
+  if (total_circuits >= 1.0) {
+    timeout_rate = cbt->num_circ_timeouts / total_circuits;
+    close_rate = cbt->num_circ_closed / total_circuits;
+  }
+
+  tor_asprintf(&args, "TOTAL_TIMES=%lu "
+               "TIMEOUT_MS=%lu XM=%lu ALPHA=%f CUTOFF_QUANTILE=%f "
+               "TIMEOUT_RATE=%f CLOSE_MS=%lu CLOSE_RATE=%f",
+               (unsigned long)cbt->total_build_times,
+               (unsigned long)cbt->timeout_ms,
+               (unsigned long)cbt->Xm, cbt->alpha, qnt,
+               timeout_rate,
+               (unsigned long)cbt->close_ms,
+               close_rate);
+
+  control_event_buildtimeout_set(type, args);
+
+  tor_free(args);
+}
 /** Set <b>global_event_mask*</b> to the bitwise OR of each live control
  * connection's event_mask field. */
 void
diff --git a/src/feature/control/control_events.h b/src/feature/control/control_events.h
index 4a5492b510..0c8448e0f8 100644
--- a/src/feature/control/control_events.h
+++ b/src/feature/control/control_events.h
@@ -223,6 +223,8 @@ void control_event_hs_descriptor_content(const char *onion_address,
                                          const char *desc_id,
                                          const char *hsdir_fp,
                                          const char *content);
+void cbt_control_event_buildtimeout_set(const circuit_build_times_t *cbt,
+                                        buildtimeout_set_event_t type);
 
 void control_events_free_all(void);