nodeinfo: implement MRF transparency exclusions

CHANGELOG.md

@@ -22,6 +22,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added
 - MRF: Support for priming the mediaproxy cache (`Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy`)
+- MRF: Support for excluding specific domains from Transparency.
 - Configuration: `federation_incoming_replies_max_depth` option
 - Mastodon API: Support for the [`tagged` filter](https://github.com/tootsuite/mastodon/pull/9755) in [`GET /api/v1/accounts/:id/statuses`](https://docs.joinmastodon.org/api/rest/accounts/#get-api-v1-accounts-id-statuses)
 - Mastodon API, streaming: Add support for passing the token in the `Sec-WebSocket-Protocol` header

config/config.exs

@@ -240,6 +240,7 @@
     "text/bbcode"
   ],
   mrf_transparency: true,
+  mrf_transparency_exclusions: [],
   autofollowed_nicknames: [],
   max_pinned_statuses: 1,
   no_attachment_links: false,

docs/config.md

@@ -106,6 +106,7 @@ config :pleroma, Pleroma.Emails.Mailer,
 * `managed_config`: Whenether the config for pleroma-fe is configured in this config or in ``static/config.json``
 * `allowed_post_formats`: MIME-type list of formats allowed to be posted (transformed into HTML)
 * `mrf_transparency`: Make the content of your Message Rewrite Facility settings public (via nodeinfo).
+* `mrf_transparency_exclusions`: Exclude specific instance names from MRF transparency.
 * `scope_copy`: Copy the scope (private/unlisted/public) in replies to posts by default.
 * `subject_line_behavior`: Allows changing the default behaviour of subject lines in replies. Valid values:
   * "email": Copy and preprend re:, as in email.

lib/pleroma/web/nodeinfo/nodeinfo_controller.ex

@@ -34,8 +34,11 @@ def schemas(conn, _params) do
   def raw_nodeinfo do
     stats = Stats.get_stats()
 
+    exclusions = Config.get([:instance, :mrf_transparency_exclusions])
+
     mrf_simple =
       Config.get(:mrf_simple)
+      |> Enum.map(fn {k, v} -> {k, Enum.reject(v, fn v -> v in exclusions end)} end)
       |> Enum.into(%{})
 
     # This horror is needed to convert regex sigils to strings
@@ -86,7 +89,8 @@ def raw_nodeinfo do
           mrf_simple: mrf_simple,
           mrf_keyword: mrf_keyword,
           mrf_user_allowlist: mrf_user_allowlist,
-          quarantined_instances: quarantined
+          quarantined_instances: quarantined,
+          exclusions: length(exclusions) > 0
         }
       else
         %{}

test/web/node_info_test.exs

@@ -83,4 +83,47 @@ test "it returns the safe_dm_mentions feature if enabled", %{conn: conn} do
 
     Pleroma.Config.put([:instance, :safe_dm_mentions], option)
   end
+
+  test "it shows MRF transparency data if enabled", %{conn: conn} do
+    option = Pleroma.Config.get([:instance, :mrf_transparency])
+    Pleroma.Config.put([:instance, :mrf_transparency], true)
+
+    simple_config = %{"reject" => ["example.com"]}
+    Pleroma.Config.put(:mrf_simple, simple_config)
+
+    response =
+      conn
+      |> get("/nodeinfo/2.1.json")
+      |> json_response(:ok)
+
+    assert response["metadata"]["federation"]["mrf_simple"] == simple_config
+
+    Pleroma.Config.put([:instance, :mrf_transparency], option)
+    Pleroma.Config.put(:mrf_simple, %{})
+  end
+
+  test "it performs exclusions from MRF transparency data if configured", %{conn: conn} do
+    option = Pleroma.Config.get([:instance, :mrf_transparency])
+    Pleroma.Config.put([:instance, :mrf_transparency], true)
+
+    exclusions = Pleroma.Config.get([:instance, :mrf_transparency_exclusions])
+    Pleroma.Config.put([:instance, :mrf_transparency_exclusions], ["other.site"])
+
+    simple_config = %{"reject" => ["example.com", "other.site"]}
+    expected_config = %{"reject" => ["example.com"]}
+
+    Pleroma.Config.put(:mrf_simple, simple_config)
+
+    response =
+      conn
+      |> get("/nodeinfo/2.1.json")
+      |> json_response(:ok)
+
+    assert response["metadata"]["federation"]["mrf_simple"] == expected_config
+    assert response["metadata"]["federation"]["exclusions"] == true
+
+    Pleroma.Config.put([:instance, :mrf_transparency], option)
+    Pleroma.Config.put([:instance, :mrf_transparency_exclusions], exclusions)
+    Pleroma.Config.put(:mrf_simple, %{})
+  end
 end