127 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
| # Pleroma: A lightweight social networking server
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| # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
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| # SPDX-License-Identifier: AGPL-3.0-only
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| 
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| defmodule Pleroma.Web.ActivityPub.MRF.HellthreadPolicy do
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|   alias Pleroma.User
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| 
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|   require Pleroma.Constants
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| 
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|   @moduledoc "Block messages with too much mentions (configurable)"
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| 
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|   @behaviour Pleroma.Web.ActivityPub.MRF
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| 
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|   defp delist_message(message, threshold) when threshold > 0 do
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|     follower_collection = User.get_cached_by_ap_id(message["actor"]).follower_address
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|     to = message["to"] || []
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|     cc = message["cc"] || []
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| 
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|     follower_collection? = Enum.member?(to ++ cc, follower_collection)
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| 
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|     message =
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|       case get_recipient_count(message) do
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|         {:public, recipients}
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|         when follower_collection? and recipients > threshold ->
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|           message
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|           |> Map.put("to", [follower_collection])
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|           |> Map.put("cc", [Pleroma.Constants.as_public()])
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| 
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|         {:public, recipients} when recipients > threshold ->
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|           message
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|           |> Map.put("to", [])
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|           |> Map.put("cc", [Pleroma.Constants.as_public()])
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| 
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|         _ ->
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|           message
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|       end
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| 
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|     {:ok, message}
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|   end
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| 
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|   defp delist_message(message, _threshold), do: {:ok, message}
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| 
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|   defp reject_message(message, threshold) when threshold > 0 do
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|     with {_, recipients} <- get_recipient_count(message) do
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|       if recipients > threshold do
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|         {:reject, "[HellthreadPolicy] #{recipients} recipients is over the limit of #{threshold}"}
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|       else
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|         {:ok, message}
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|       end
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|     end
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|   end
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| 
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|   defp reject_message(message, _threshold), do: {:ok, message}
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| 
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|   defp get_recipient_count(message) do
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|     recipients = (message["to"] || []) ++ (message["cc"] || [])
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|     follower_collection = User.get_cached_by_ap_id(message["actor"]).follower_address
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| 
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|     if Enum.member?(recipients, Pleroma.Constants.as_public()) do
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|       recipients =
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|         recipients
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|         |> List.delete(Pleroma.Constants.as_public())
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|         |> List.delete(follower_collection)
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| 
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|       {:public, length(recipients)}
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|     else
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|       recipients =
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|         recipients
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|         |> List.delete(follower_collection)
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| 
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|       {:not_public, length(recipients)}
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|     end
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|   end
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| 
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|   @impl true
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|   def filter(%{"type" => "Create", "object" => %{"type" => object_type}} = message)
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|       when object_type in ~w{Note Article} do
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|     reject_threshold =
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|       Pleroma.Config.get(
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|         [:mrf_hellthread, :reject_threshold],
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|         Pleroma.Config.get([:mrf_hellthread, :threshold])
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|       )
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| 
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|     delist_threshold = Pleroma.Config.get([:mrf_hellthread, :delist_threshold])
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| 
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|     with {:ok, message} <- reject_message(message, reject_threshold),
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|          {:ok, message} <- delist_message(message, delist_threshold) do
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|       {:ok, message}
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|     else
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|       e -> e
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|     end
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|   end
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| 
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|   @impl true
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|   def filter(message), do: {:ok, message}
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| 
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|   @impl true
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|   def describe,
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|     do: {:ok, %{mrf_hellthread: Pleroma.Config.get(:mrf_hellthread) |> Enum.into(%{})}}
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| 
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|   @impl true
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|   def config_description do
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|     %{
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|       key: :mrf_hellthread,
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|       related_policy: "Pleroma.Web.ActivityPub.MRF.HellthreadPolicy",
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|       label: "MRF Hellthread",
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|       description: "Block messages with excessive user mentions",
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|       children: [
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|         %{
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|           key: :delist_threshold,
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|           type: :integer,
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|           description:
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|             "Number of mentioned users after which the message gets removed from timelines and" <>
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|               "disables notifications. Set to 0 to disable.",
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|           suggestions: [10]
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|         },
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|         %{
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|           key: :reject_threshold,
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|           type: :integer,
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|           description:
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|             "Number of mentioned users after which the messaged gets rejected. Set to 0 to disable.",
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|           suggestions: [20]
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|         }
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|       ]
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|     }
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|   end
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| end
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