Add report filtering to MRF.SimplePolicy

config/config.exs

@@ -298,6 +298,7 @@ config :pleroma, :mrf_simple,
   media_removal: [],
   media_nsfw: [],
   federated_timeline_removal: [],
+  report_removal: [],
   reject: [],
   accept: []
 

lib/pleroma/web/activity_pub/mrf/simple_policy.ex

@@ -94,6 +94,16 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicy do
     {:ok, object}
   end
 
+  defp check_report_removal(%{host: actor_host} = _actor_info, %{"type" => "Flag"} = object) do
+    if actor_host in Pleroma.Config.get([:mrf_simple, :report_removal]) do
+      {:reject, nil}
+    else
+      {:ok, object}
+    end
+  end
+
+  defp check_report_removal(_actor_info, object), do: {:ok, object}
+
   @impl true
   def filter(object) do
     actor_info = URI.parse(object["actor"])
@@ -102,7 +112,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicy do
          {:ok, object} <- check_reject(actor_info, object),
          {:ok, object} <- check_media_removal(actor_info, object),
          {:ok, object} <- check_media_nsfw(actor_info, object),
-         {:ok, object} <- check_ftl_removal(actor_info, object) do
+         {:ok, object} <- check_ftl_removal(actor_info, object),
+         {:ok, object} <- check_report_removal(actor_info, object) do
       {:ok, object}
     else
       _e -> {:reject, nil}

test/web/activity_pub/mrf/simple_policy_test.exs

@@ -15,6 +15,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
       media_removal: [],
       media_nsfw: [],
       federated_timeline_removal: [],
+      report_removal: [],
       reject: [],
       accept: []
     )
@@ -85,6 +86,33 @@ defmodule Pleroma.Web.ActivityPub.MRF.SimplePolicyTest do
     }
   end
 
+  describe "when :report_removal" do
+    test "is empty" do
+      Config.put([:mrf_simple, :report_removal], [])
+      report_message = build_report_message()
+      local_message = build_local_message()
+
+      assert SimplePolicy.filter(report_message) == {:ok, report_message}
+      assert SimplePolicy.filter(local_message) == {:ok, local_message}
+    end
+
+    test "has a matching host" do
+      Config.put([:mrf_simple, :report_removal], ["remote.instance"])
+      report_message = build_report_message()
+      local_message = build_local_message()
+
+      assert SimplePolicy.filter(report_message) == {:reject, nil}
+      assert SimplePolicy.filter(local_message) == {:ok, local_message}
+    end
+  end
+
+  defp build_report_message do
+    %{
+      "actor" => "https://remote.instance/users/bob",
+      "type" => "Flag"
+    }
+  end
+
   describe "when :federated_timeline_removal" do
     test "is empty" do
       Config.put([:mrf_simple, :federated_timeline_removal], [])