From 92362e1e22a3debfaf3275822519417ee8755a7a Mon Sep 17 00:00:00 2001
From: Karen Konou <konoukaren@gmail.com>
Date: Sat, 22 Dec 2018 23:18:31 +0100
Subject: [PATCH] Implement large thread filter

---
 config/config.exs                                 |  2 ++
 .../web/activity_pub/mrf/hellthread_policy.ex     | 15 +++++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex

diff --git a/config/config.exs b/config/config.exs
index 65d7346de..de834e03a 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -163,6 +163,8 @@ config :pleroma, :mrf_rejectnonpublic,
   allow_followersonly: false,
   allow_direct: false
 
+config :pleroma, :mrf_hellthreadmitigation, threshold: 10  
+
 config :pleroma, :mrf_simple,
   media_removal: [],
   media_nsfw: [],
diff --git a/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex b/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex
new file mode 100644
index 000000000..0e0918126
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex
@@ -0,0 +1,15 @@
+defmodule Pleroma.Web.ActivityPub.MRF.HellthreadPolicy do
+  @behaviour Pleroma.Web.ActivityPub.MRF
+
+  @impl true
+  def filter(object) do
+
+    policy = Pleroma.Config.get(:mrf_hellthreadmitigation)
+
+    if (length(object["to"]) + length(object["cc"])) > Keyword.get(policy, :threshold) do
+      {:reject, nil}
+    else
+      {:ok, object}
+    end
+  end
+end
\ No newline at end of file