Defer reporting directory bootstrap progress

Existing cached directory information can cause misleadingly high
bootstrap percentages.  To improve user experience, defer reporting of
directory information progress until at least one connection has
succeeded to a relay or bridge.

Closes ticket 27169.

changes/ticket27169

@@ -0,0 +1,6 @@
+  o Minor features (bootstrap):
+    - Improve user experience by deferring directory progress
+      reporting until after a connection to a relay or bridge has
+      succeeded.  This avoids reporting 80% progress based on cached
+      directory information when we can't even connect to a bridge or
+      relay.  Closes ticket 27169.

src/core/or/connection_or.c

@@ -705,6 +705,7 @@ connection_or_finished_connecting(or_connection_t *or_conn)
   log_debug(LD_HANDSHAKE,"OR connect() to router at %s:%u finished.",
             conn->address,conn->port);
   control_event_bootstrap(BOOTSTRAP_STATUS_HANDSHAKE, 0);
+  control_event_boot_first_orconn();
 
   if (proxy_type != PROXY_NONE) {
     /* start proxy handshake */

src/core/or/relay.c

@@ -1389,8 +1389,8 @@ connection_edge_process_relay_cell_not_open(
         case DIR_PURPOSE_FETCH_SERVERDESC:
         case DIR_PURPOSE_FETCH_MICRODESC:
           if (TO_DIR_CONN(dirconn)->router_purpose == ROUTER_PURPOSE_GENERAL)
-            control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
-                                    count_loading_descriptors_progress());
+            control_event_boot_dir(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
+                                   count_loading_descriptors_progress());
           break;
       }
     }

src/feature/control/control.c

@@ -7178,6 +7178,45 @@ control_event_bootstrap(bootstrap_status_t status, int progress)
   }
 }
 
+/** Flag whether we've opened an OR_CONN yet  */
+static int bootstrap_first_orconn = 0;
+
+/** Like bootstrap_phase, but for (possibly deferred) directory progress */
+static int bootstrap_dir_phase = BOOTSTRAP_STATUS_UNDEF;
+
+/** Like bootstrap_problems, but for (possibly deferred) directory progress  */
+static int bootstrap_dir_progress = BOOTSTRAP_STATUS_UNDEF;
+
+/** Defer directory info bootstrap events until we have successfully
+ * completed our first connection to a router.  */
+void
+control_event_boot_dir(bootstrap_status_t status, int progress)
+{
+  if (status > bootstrap_dir_progress) {
+    bootstrap_dir_progress = status;
+    bootstrap_dir_phase = status;
+  }
+  if (progress && progress >= bootstrap_dir_progress) {
+    bootstrap_dir_progress = progress;
+  }
+
+  /* Don't report unless we have successfully opened at least one OR_CONN */
+  if (!bootstrap_first_orconn)
+    return;
+
+  control_event_bootstrap(status, progress);
+}
+
+/** Set a flag to allow reporting of directory bootstrap progress.
+ * (Code that reports completion of an OR_CONN calls this.)  Also,
+ * report directory progress so far. */
+void
+control_event_boot_first_orconn(void)
+{
+  bootstrap_first_orconn = 1;
+  control_event_bootstrap(bootstrap_dir_phase, bootstrap_dir_progress);
+}
+
 /** Called when Tor has failed to make bootstrapping progress in a way
  * that indicates a problem. <b>warn</b> gives a human-readable hint
  * as to why, and <b>reason</b> provides a controller-facing short

src/feature/control/control.h

@@ -195,6 +195,8 @@ void control_event_bootstrap(bootstrap_status_t status, int progress);
 MOCK_DECL(void, control_event_bootstrap_prob_or,(const char *warn,
                                                  int reason,
                                                  or_connection_t *or_conn));
+void control_event_boot_dir(bootstrap_status_t status, int progress);
+void control_event_boot_first_orconn(void);
 void control_event_bootstrap_problem(const char *warn, const char *reason,
                                      const connection_t *conn, int dowarn);
 

src/feature/dircache/directory.c

@@ -2226,8 +2226,8 @@ load_downloaded_routers(const char *body, smartlist_t *which,
   added = router_load_routers_from_string(body, NULL, SAVED_NOWHERE, which,
                                   descriptor_digests, buf);
   if (added && general)
-    control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
-                            count_loading_descriptors_progress());
+    control_event_boot_dir(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
+                           count_loading_descriptors_progress());
   return added;
 }
 
@@ -2949,8 +2949,8 @@ handle_response_fetch_microdesc(dir_connection_t *conn,
       dir_microdesc_download_failed(which, status_code, conn->identity_digest);
     }
     if (mds && smartlist_len(mds)) {
-      control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
-                              count_loading_descriptors_progress());
+      control_event_boot_dir(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
+                             count_loading_descriptors_progress());
       directory_info_has_arrived(now, 0, 1);
     }
     SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));

src/feature/nodelist/nodelist.c

@@ -2528,7 +2528,7 @@ update_router_have_minimum_dir_info(void)
                    (int)(paths*100), status);
       tor_free(status);
       res = 0;
-      control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS, 0);
+      control_event_boot_dir(BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS, 0);
       goto done;
     }
 
@@ -2553,7 +2553,7 @@ update_router_have_minimum_dir_info(void)
   /* If paths have just become available in this update. */
   if (res && !have_min_dir_info) {
     control_event_client_status(LOG_NOTICE, "ENOUGH_DIR_INFO");
-    control_event_bootstrap(BOOTSTRAP_STATUS_CONN_OR, 0);
+    control_event_boot_dir(BOOTSTRAP_STATUS_CONN_OR, 0);
     log_info(LD_DIR,
              "We now have enough directory information to build circuits.");
   }

src/test/test_controller_events.c

@@ -322,6 +322,72 @@ test_cntev_event_mask(void *arg)
   ;
 }
 
+static char *saved_event_str = NULL;
+
+static void
+mock_queue_control_event_string(uint16_t event, char *msg)
+{
+  (void)event;
+
+  tor_free(saved_event_str);
+  saved_event_str = msg;
+}
+
+/* Helper macro for checking bootstrap control event strings */
+#define assert_bootmsg(s)                                               \
+  tt_ptr_op(strstr(saved_event_str, "650 STATUS_CLIENT NOTICE "         \
+                   "BOOTSTRAP PROGRESS=" s), OP_EQ, saved_event_str)
+
+/* Test deferral of directory bootstrap messages (requesting_descriptors) */
+static void
+test_cntev_dirboot_defer_desc(void *arg)
+{
+  (void)arg;
+
+  MOCK(queue_control_event_string, mock_queue_control_event_string);
+  control_testing_set_global_event_mask(EVENT_MASK_(EVENT_STATUS_CLIENT));
+  control_event_bootstrap(BOOTSTRAP_STATUS_STARTING, 0);
+  assert_bootmsg("0 TAG=starting");
+  /* This event should get deferred */
+  control_event_boot_dir(BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS, 0);
+  assert_bootmsg("0 TAG=starting");
+  control_event_bootstrap(BOOTSTRAP_STATUS_CONN_DIR, 0);
+  assert_bootmsg("5 TAG=conn_dir");
+  control_event_bootstrap(BOOTSTRAP_STATUS_HANDSHAKE, 0);
+  assert_bootmsg("10 TAG=handshake_dir");
+  /* The deferred event should appear */
+  control_event_boot_first_orconn();
+  assert_bootmsg("45 TAG=requesting_descriptors");
+ done:
+  tor_free(saved_event_str);
+  UNMOCK(queue_control_event_string);
+}
+
+/* Test deferral of directory bootstrap messages (conn_or) */
+static void
+test_cntev_dirboot_defer_orconn(void *arg)
+{
+  (void)arg;
+
+  MOCK(queue_control_event_string, mock_queue_control_event_string);
+  control_testing_set_global_event_mask(EVENT_MASK_(EVENT_STATUS_CLIENT));
+  control_event_bootstrap(BOOTSTRAP_STATUS_STARTING, 0);
+  assert_bootmsg("0 TAG=starting");
+  /* This event should get deferred */
+  control_event_boot_dir(BOOTSTRAP_STATUS_CONN_OR, 0);
+  assert_bootmsg("0 TAG=starting");
+  control_event_bootstrap(BOOTSTRAP_STATUS_CONN_DIR, 0);
+  assert_bootmsg("5 TAG=conn_dir");
+  control_event_bootstrap(BOOTSTRAP_STATUS_HANDSHAKE, 0);
+  assert_bootmsg("10 TAG=handshake_dir");
+  /* The deferred event should appear */
+  control_event_boot_first_orconn();
+  assert_bootmsg("80 TAG=conn_or");
+ done:
+  tor_free(saved_event_str);
+  UNMOCK(queue_control_event_string);
+}
+
 #define TEST(name, flags)                                               \
   { #name, test_cntev_ ## name, flags, 0, NULL }
 
@@ -330,5 +396,7 @@ struct testcase_t controller_event_tests[] = {
   TEST(append_cell_stats, TT_FORK),
   TEST(format_cell_stats, TT_FORK),
   TEST(event_mask, TT_FORK),
+  TEST(dirboot_defer_desc, TT_FORK),
+  TEST(dirboot_defer_orconn, TT_FORK),
   END_OF_TESTCASES
 };