anti_followbot_policy.ex (2405B)
- # Pleroma: A lightweight social networking server
- # Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
- # SPDX-License-Identifier: AGPL-3.0-only
- defmodule Pleroma.Web.ActivityPub.MRF.AntiFollowbotPolicy do
- alias Pleroma.User
- @moduledoc "Prevent followbots from following with a bit of heuristic"
- @behaviour Pleroma.Web.ActivityPub.MRF.Policy
- # XXX: this should become User.normalize_by_ap_id() or similar, really.
- defp normalize_by_ap_id(%{"id" => id}), do: User.get_cached_by_ap_id(id)
- defp normalize_by_ap_id(uri) when is_binary(uri), do: User.get_cached_by_ap_id(uri)
- defp normalize_by_ap_id(_), do: nil
- defp score_nickname("followbot@" <> _), do: 1.0
- defp score_nickname("federationbot@" <> _), do: 1.0
- defp score_nickname("federation_bot@" <> _), do: 1.0
- defp score_nickname(_), do: 0.0
- defp score_displayname("federation bot"), do: 1.0
- defp score_displayname("federationbot"), do: 1.0
- defp score_displayname("fedibot"), do: 1.0
- defp score_displayname(_), do: 0.0
- defp determine_if_followbot(%User{nickname: nickname, name: displayname, actor_type: actor_type}) do
- # nickname will be a binary string except when following a relay
- nick_score =
- if is_binary(nickname) do
- nickname
- |> String.downcase()
- |> score_nickname()
- else
- 0.0
- end
- # displayname will either be a binary string or nil, if a displayname isn't set.
- name_score =
- if is_binary(displayname) do
- displayname
- |> String.downcase()
- |> score_displayname()
- else
- 0.0
- end
- # actor_type "Service" is a Bot account
- actor_type_score =
- if actor_type == "Service" do
- 1.0
- else
- 0.0
- end
- nick_score + name_score + actor_type_score
- end
- defp bot_allowed?(%{"object" => target}, bot_actor) do
- %User{} = user = normalize_by_ap_id(target)
- User.following?(user, bot_actor)
- end
- @impl true
- def filter(%{"type" => "Follow", "actor" => actor_id} = message) do
- %User{} = actor = normalize_by_ap_id(actor_id)
- score = determine_if_followbot(actor)
- if score < 0.8 || bot_allowed?(message, actor) do
- {:ok, message}
- else
- {:reject, "[AntiFollowbotPolicy] Scored #{actor_id} as #{score}"}
- end
- end
- @impl true
- def filter(message), do: {:ok, message}
- @impl true
- def describe, do: {:ok, %{}}
- end