RemoteReportPolicy: add `reject_third_party` option

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex b/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex
index 0bd83d8f0..964c59cbf 100644
--- a/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/remote_report_policy.ex
@@ -9,6 +9,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.RemoteReportPolicy do
     with {_, false} <- {:local, local?(object)},
          {:ok, _} <- maybe_reject_all(object),
          {:ok, _} <- maybe_reject_anonymous(object),
+         {:ok, _} <- maybe_reject_third_party(object),
          {:ok, _} <- maybe_reject_empty_message(object) do
       {:ok, object}
     else
@@ -37,6 +38,21 @@ defmodule Pleroma.Web.ActivityPub.MRF.RemoteReportPolicy do
     end
   end
 
+  defp maybe_reject_third_party(%{"object" => objects} = object) do
+    {_, to} = case objects do
+      [head | tail] when is_binary(head) -> {tail, head}
+      s when is_binary(s) -> {[], s}
+      _ -> {[], ""}
+    end
+
+    with true <- Config.get([:mrf_remote_report, :reject_third_party]),
+         String.starts_with?(to, Pleroma.Web.Endpoint.url()) do
+      {:reject, "[RemoteReportPolicy] Third-party: #{to}"}
+    else
+      _ -> {:ok, object}
+    end
+  end
+
   defp maybe_reject_empty_message(%{"content" => content} = object)
        when is_binary(content) and content != "" do
     {:ok, object}
@@ -84,6 +100,12 @@ defmodule Pleroma.Web.ActivityPub.MRF.RemoteReportPolicy do
           suggestions: [true]
         },
         %{
+          key: :reject_third_party,
+          type: :boolean,
+          description: "Reject reports on users from third-party instances?",
+          suggestions: [true]
+        },
+        %{
           key: :reject_empty_message,
           type: :boolean,
           description: "Reject remote reports with no message?",