4 files changed, 76 insertions, 26 deletions

diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 0199ac9e7..4635e7fcd 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.ActivityPub.ActivityPub do
-  alias Pleroma.{Activity, Repo, Object, Upload, User, Notification}
+  alias Pleroma.{Activity, Repo, Object, Upload, User, Notification, Instances}
   alias Pleroma.Web.ActivityPub.{Transmogrifier, MRF}
   alias Pleroma.Web.WebFinger
   alias Pleroma.Web.Federator
@@ -734,7 +734,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   end
 
   def publish(actor, activity) do
-    followers =
+    remote_followers =
       if actor.follower_address in activity.recipients do
         {:ok, followers} = User.get_followers(actor)
         followers |> Enum.filter(&(!&1.local))
@@ -744,29 +744,31 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
     public = is_public?(activity)
 
-    remote_inboxes =
-      (Pleroma.Web.Salmon.remote_users(activity) ++ followers)
+    reachable_inboxes_metadata =
+      (Pleroma.Web.Salmon.remote_users(activity) ++ remote_followers)
       |> Enum.filter(fn user -> User.ap_enabled?(user) end)
       |> Enum.map(fn %{info: %{source_data: data}} ->
         (is_map(data["endpoints"]) && Map.get(data["endpoints"], "sharedInbox")) || data["inbox"]
       end)
       |> Enum.uniq()
       |> Enum.filter(fn inbox -> should_federate?(inbox, public) end)
+      |> Instances.filter_reachable()
 
     {:ok, data} = Transmogrifier.prepare_outgoing(activity.data)
     json = Jason.encode!(data)
 
-    Enum.each(remote_inboxes, fn inbox ->
+    Enum.each(reachable_inboxes_metadata, fn {inbox, unreachable_since} ->
       Federator.enqueue(:publish_single_ap, %{
         inbox: inbox,
         json: json,
         actor: actor,
-        id: activity.data["id"]
+        id: activity.data["id"],
+        unreachable_since: unreachable_since
       })
     end)
   end
 
-  def publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
+  def publish_one(%{inbox: inbox, json: json, actor: actor, id: id} = params) do
     Logger.info("Federating #{id} to #{inbox}")
     host = URI.parse(inbox).host
 
@@ -779,15 +781,26 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
         digest: digest
       })
 
-    @httpoison.post(
-      inbox,
-      json,
-      [
-        {"Content-Type", "application/activity+json"},
-        {"signature", signature},
-        {"digest", digest}
-      ]
-    )
+    with {:ok, %{status: code}} when code in 200..299 <-
+           result =
+             @httpoison.post(
+               inbox,
+               json,
+               [
+                 {"Content-Type", "application/activity+json"},
+                 {"signature", signature},
+                 {"digest", digest}
+               ]
+             ) do
+      if !Map.has_key?(params, :unreachable_since) || params[:unreachable_since],
+        do: Instances.set_reachable(inbox)
+
+      result
+    else
+      {_post_result, response} ->
+        unless params[:unreachable_since], do: Instances.set_unreachable(inbox)
+        {:error, response}
+    end
   end
 
   # TODO:
diff --git a/lib/pleroma/web/activity_pub/activity_pub_controller.ex b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
index 7eed0a600..4dea6ab83 100644
--- a/lib/pleroma/web/activity_pub/activity_pub_controller.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub_controller.ex
@@ -4,6 +4,7 @@
 
 defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   use Pleroma.Web, :controller
+
   alias Pleroma.{Activity, User, Object}
   alias Pleroma.Web.ActivityPub.{ObjectView, UserView}
   alias Pleroma.Web.ActivityPub.ActivityPub
@@ -17,6 +18,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
   action_fallback(:errors)
 
   plug(Pleroma.Web.FederatingPlug when action in [:inbox, :relay])
+  plug(:set_requester_reachable when action in [:inbox])
   plug(:relay_active? when action in [:relay])
 
   def relay_active?(conn, _) do
@@ -289,4 +291,13 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubController do
     |> put_status(500)
     |> json("error")
   end
+
+  defp set_requester_reachable(%Plug.Conn{} = conn, _) do
+    with actor <- conn.params["actor"],
+         true <- is_binary(actor) do
+      Pleroma.Instances.set_reachable(actor)
+    end
+
+    conn
+  end
 end
diff --git a/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex b/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex
index a3f516ae7..4c6e612b2 100644
--- a/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex
@@ -3,20 +3,46 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.ActivityPub.MRF.HellthreadPolicy do
+  alias Pleroma.User
   @behaviour Pleroma.Web.ActivityPub.MRF
 
+  defp delist_message(message) do
+    follower_collection = User.get_cached_by_ap_id(message["actor"]).follower_address
+
+    message
+    |> Map.put("to", [follower_collection])
+    |> Map.put("cc", ["https://www.w3.org/ns/activitystreams#Public"])
+  end
+
   @impl true
-  def filter(%{"type" => "Create"} = object) do
-    threshold = Pleroma.Config.get([:mrf_hellthread, :threshold])
-    recipients = (object["to"] || []) ++ (object["cc"] || [])
-
-    if length(recipients) > threshold do
-      {:reject, nil}
-    else
-      {:ok, object}
+  def filter(%{"type" => "Create"} = message) do
+    delist_threshold = Pleroma.Config.get([:mrf_hellthread, :delist_threshold])
+
+    reject_threshold =
+      Pleroma.Config.get(
+        [:mrf_hellthread, :reject_threshold],
+        Pleroma.Config.get([:mrf_hellthread, :threshold])
+      )
+
+    recipients = (message["to"] || []) ++ (message["cc"] || [])
+
+    cond do
+      length(recipients) > reject_threshold and reject_threshold > 0 ->
+        {:reject, nil}
+
+      length(recipients) > delist_threshold and delist_threshold > 0 ->
+        if Enum.member?(message["to"], "https://www.w3.org/ns/activitystreams#Public") or
+             Enum.member?(message["cc"], "https://www.w3.org/ns/activitystreams#Public") do
+          {:ok, delist_message(message)}
+        else
+          {:ok, message}
+        end
+
+      true ->
+        {:ok, message}
     end
   end
 
   @impl true
-  def filter(object), do: {:ok, object}
+  def filter(message), do: {:ok, message}
 end
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index 3b0cdfe71..4a2cc6738 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -285,7 +285,7 @@ defmodule Pleroma.Web.ActivityPub.Utils do
            |> Map.put("#{property}_count", length(element))
            |> Map.put("#{property}s", element),
          changeset <- Changeset.change(object, data: new_data),
-         {:ok, object} <- Repo.update(changeset),
+         {:ok, object} <- Object.update_and_set_cache(changeset),
          _ <- update_object_in_activities(object) do
       {:ok, object}
     end