Merge branch 'develop' into 'remove-twitter-api'

[akkoma] / lib / pleroma / web / federator / federator.ex

diff --git a/lib/pleroma/web/federator/federator.ex b/lib/pleroma/web/federator/federator.ex
index f506a7d245eace7c06bff5bcb2dde6a22e6a84b0..f5803578db37ff594e9d8c7030e503e7323b6398 100644 (file)
--- a/lib/pleroma/web/federator/federator.ex
+++ b/lib/pleroma/web/federator/federator.ex
@@ -1,5 +1,5 @@
 # Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.Federator do
@@ -15,13 +15,19 @@ defmodule Pleroma.Web.Federator do
 
   require Logger
 
-  @doc "Addresses [memory leaks on recursive replies fetching](https://git.pleroma.social/pleroma/pleroma/issues/161)"
+  @doc """
+  Returns `true` if the distance to target object does not exceed max configured value.
+  Serves to prevent fetching of very long threads, especially useful on smaller instances.
+  Addresses [memory leaks on recursive replies fetching](https://git.pleroma.social/pleroma/pleroma/issues/161).
+  Applies to fetching of both ancestor (reply-to) and child (reply) objects.
+  """
   # credo:disable-for-previous-line Credo.Check.Readability.MaxLineLength
-  def allowed_incoming_reply_depth?(depth) do
-    max_replies_depth = Pleroma.Config.get([:instance, :federation_incoming_replies_max_depth])
+  def allowed_thread_distance?(distance) do
+    max_distance = Pleroma.Config.get([:instance, :federation_incoming_replies_max_depth])
 
-    if max_replies_depth do
-      (depth || 1) <= max_replies_depth
+    if max_distance && max_distance >= 0 do
+      # Default depth is 0 (an object has zero distance from itself in its thread)
+      (distance || 0) <= max_distance
     else
       true
     end
@@ -66,19 +72,24 @@ defmodule Pleroma.Web.Federator do
     # actor shouldn't be acting on objects outside their own AP server.
     with {:ok, _user} <- ap_enabled_actor(params["actor"]),
          nil <- Activity.normalize(params["id"]),
-         :ok <- Containment.contain_origin_from_id(params["actor"], params),
+         {_, :ok} <-
+           {:correct_origin?, Containment.contain_origin_from_id(params["actor"], params)},
          {:ok, activity} <- Transmogrifier.handle_incoming(params) do
       {:ok, activity}
     else
+      {:correct_origin?, _} ->
+        Logger.debug("Origin containment failure for #{params["id"]}")
+        {:error, :origin_containment_failed}
+
       %Activity{} ->
         Logger.debug("Already had #{params["id"]}")
-        :error
+        {:error, :already_present}
 
-      _e ->
+      e ->
         # Just drop those for now
         Logger.debug("Unhandled activity")
         Logger.debug(Jason.encode!(params, pretty: true))
-        :error
+        {:error, e}
     end
   end