hs: Remove dead code and uneeded feature

When merging #20657, somehow hs_service_dir_info_changed() became unused
leading to not use the re-upload to HSDir when we were missing information
feature.

Turns out that it is not possible to pick an HSDir with a missing descriptor
because in order to compute the HSDir index, the descriptor is mandatory to
have so we can know its position on the hashring.

This commit removes that dead feature and fix the
hs_service_dir_info_changed() not being used.

Signed-off-by: David Goulet <dgoulet@torproject.org>

src/or/hs_service.c

@@ -972,8 +972,6 @@ service_descriptor_free(hs_service_descriptor_t *desc)
   hs_descriptor_free(desc->desc);
   memwipe(&desc->signing_kp, 0, sizeof(desc->signing_kp));
   memwipe(&desc->blinded_kp, 0, sizeof(desc->blinded_kp));
-  SMARTLIST_FOREACH(desc->hsdir_missing_info, char *, id, tor_free(id));
-  smartlist_free(desc->hsdir_missing_info);
   /* Cleanup all intro points. */
   digest256map_free(desc->intro_points.map, service_intro_point_free_);
   digestmap_free(desc->intro_points.failed_id, tor_free_);
@@ -993,7 +991,6 @@ service_descriptor_new(void)
   /* Initialize the intro points map. */
   sdesc->intro_points.map = digest256map_new();
   sdesc->intro_points.failed_id = digestmap_new();
-  sdesc->hsdir_missing_info = smartlist_new();
   sdesc->previous_hsdirs = smartlist_new();
   return sdesc;
 }
@@ -2324,18 +2321,6 @@ upload_descriptor_to_all(const hs_service_t *service,
     /* Getting responsible hsdir implies that the node_t object exists for the
      * routerstatus_t found in the consensus else we have a problem. */
     tor_assert(hsdir_node);
-    /* Do not upload to an HSDir we don't have a descriptor for. */
-    if (!node_has_descriptor(hsdir_node)) {
-      log_info(LD_REND, "Missing descriptor for HSDir %s. Not uploading "
-                        "descriptor. We'll try later once we have it.",
-               safe_str_client(node_describe(hsdir_node)));
-      /* Once we get new directory information, this HSDir will be retried if
-       * we ever get the descriptor. */
-      smartlist_add(desc->hsdir_missing_info,
-                    tor_memdup(hsdir_rs->identity_digest, DIGEST_LEN));
-      continue;
-    }
-
     /* Upload this descriptor to the chosen directory. */
     upload_descriptor_to_hsdir(service, desc, hsdir_node);
   } SMARTLIST_FOREACH_END(hsdir_rs);
@@ -2724,58 +2709,6 @@ service_handle_introduce2(origin_circuit_t *circ, const uint8_t *payload,
   return -1;
 }
 
-/* For a given service and a descriptor of that service, consider retrying to
- * upload the descriptor to any directories from which we had missing
- * information when originally tried to be uploaded. This is called when our
- * directory information has changed. */
-static void
-consider_hsdir_upload_retry(const hs_service_t *service,
-                            hs_service_descriptor_t *desc)
-{
-  smartlist_t *responsible_dirs = NULL;
-  smartlist_t *still_missing_dirs = NULL;
-
-  tor_assert(service);
-  tor_assert(desc);
-
-  responsible_dirs = smartlist_new();
-  still_missing_dirs = smartlist_new();
-
-  /* We first need to get responsible directories from the latest consensus so
-   * we can then make sure that the node that we were missing information for
-   * is still responsible for this descriptor. */
-  hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num,
-                            service->desc_next == desc, 0, responsible_dirs);
-
-  SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *, rs) {
-    const node_t *node;
-    const char *id = rs->identity_digest;
-    if (!smartlist_contains_digest(desc->hsdir_missing_info, id)) {
-      continue;
-    }
-    /* We do need a node_t object and descriptor to perform an upload. If
-     * found, we remove the id from the missing dir list else we add it to the
-     * still missing dir list to keep track of id that are still missing. */
-    node = node_get_by_id(id);
-    if (node && node_has_descriptor(node)) {
-      upload_descriptor_to_hsdir(service, desc, node);
-      smartlist_remove(desc->hsdir_missing_info, id);
-    } else {
-      smartlist_add(still_missing_dirs, tor_memdup(id, DIGEST_LEN));
-    }
-  } SMARTLIST_FOREACH_END(rs);
-
-  /* Switch the still missing dir list with the current missing dir list in
-   * the descriptor. It is possible that the list ends up empty which is what
-   * we want if we have no more missing dir. */
-  SMARTLIST_FOREACH(desc->hsdir_missing_info, char *, id, tor_free(id));
-  smartlist_free(desc->hsdir_missing_info);
-  desc->hsdir_missing_info = still_missing_dirs;
-
-  /* No ownership of the routerstatus_t object in this list. */
-  smartlist_free(responsible_dirs);
-}
-
 /* Add to list every filename used by service. This is used by the sandbox
  * subsystem. */
 static void
@@ -2802,16 +2735,6 @@ service_add_fnames_to_list(const hs_service_t *service, smartlist_t *list)
 /* Public API */
 /* ========== */
 
-/* We just received a new batch of descriptors which might affect the shape of
- * the HSDir hash ring. Signal that we should reexamine the hash ring and
- * re-upload our HS descriptors if needed. */
-void
-hs_hsdir_set_changed_consider_reupload(void)
-{
-  log_info(LD_REND, "New dirinfo arrived: consider reuploading descriptor");
-  consider_republishing_hs_descriptors = 1;
-}
-
 /* Return the number of service we have configured and usable. */
 unsigned int
 hs_service_get_num_services(void)
@@ -2981,22 +2904,14 @@ hs_service_lists_fnames_for_sandbox(smartlist_t *file_list,
 }
 
 /* Called when our internal view of the directory has changed. We might have
- * new descriptors for hidden service directories that we didn't have before
- * so try them if it's the case. */
+ * received a new batch of descriptors which might affect the shape of the
+ * HSDir hash ring. Signal that we should reexamine the hash ring and
+ * re-upload our HS descriptors if needed. */
 void
 hs_service_dir_info_changed(void)
 {
-  /* For each service we have, check every descriptor and consider retrying to
-   * upload it to directories that we might have had missing information
-   * previously that is missing a router descriptor. */
-  FOR_EACH_SERVICE_BEGIN(service) {
-    FOR_EACH_DESCRIPTOR_BEGIN(service, desc) {
-      /* This cleans up the descriptor missing hsdir information list if a
-       * successful upload is made or if any of the directory aren't
-       * responsible anymore for the service descriptor. */
-      consider_hsdir_upload_retry(service, desc);
-    } FOR_EACH_DESCRIPTOR_END;
-  } FOR_EACH_SERVICE_END;
+  log_info(LD_REND, "New dirinfo arrived: consider reuploading descriptor");
+  consider_republishing_hs_descriptors = 1;
 }
 
 /* Called when we get an INTRODUCE2 cell on the circ. Respond to the cell and

src/or/hs_service.h

@@ -123,13 +123,6 @@ typedef struct hs_service_descriptor_t {
    * couldn't pick any nodes. */
   unsigned int missing_intro_points : 1;
 
-  /* List of identity digests for hidden service directories to which we
-   * couldn't upload this descriptor because we didn't have its router
-   * descriptor at the time. If this list is non-empty, only the relays in this
-   * list are re-tried to upload this descriptor when our directory information
-   * have been updated. */
-  smartlist_t *hsdir_missing_info;
-
   /** List of the responsible HSDirs (their b64ed identity digest) last time we
    *  uploaded this descriptor. If the set of responsible HSDirs is different
    *  from this list, this means we received new dirinfo and we need to
@@ -266,7 +259,6 @@ void hs_service_lists_fnames_for_sandbox(smartlist_t *file_list,
                                          smartlist_t *dir_list);
 int hs_service_set_conn_addr_port(const origin_circuit_t *circ,
                                   edge_connection_t *conn);
-void hs_hsdir_set_changed_consider_reupload(void);
 
 void hs_service_dir_info_changed(void);
 void hs_service_run_scheduled_events(time_t now);

src/or/nodelist.c

@@ -1810,7 +1810,7 @@ router_dir_info_changed(void)
 {
   need_to_update_have_min_dir_info = 1;
   rend_hsdir_routers_changed();
-  hs_hsdir_set_changed_consider_reupload();
+  hs_service_dir_info_changed();
 }
 
 /** Return a string describing what we're missing before we have enough