Inspired by https://git.pleroma.social/moonman/emoji-stealer-mrf/-/blob/master/steal_emoji_policy.ex
		
			
				
	
	
		
			97 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
# Pleroma: A lightweight social networking server
 | 
						||
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
 | 
						||
# SPDX-License-Identifier: AGPL-3.0-only
 | 
						||
 | 
						||
defmodule Pleroma.Web.ActivityPub.MRF.StealEmojiPolicy do
 | 
						||
  require Logger
 | 
						||
 | 
						||
  alias Pleroma.Config
 | 
						||
 | 
						||
  @moduledoc "Detect new emojis by their shortcode and steals them"
 | 
						||
  @behaviour Pleroma.Web.ActivityPub.MRF
 | 
						||
 | 
						||
  defp remote_host?(host), do: host != Config.get([Pleroma.Web.Endpoint, :url, :host])
 | 
						||
 | 
						||
  defp accept_host?(host), do: host in Config.get([:mrf_steal_emoji, :hosts], [])
 | 
						||
 | 
						||
  defp steal_emoji({shortcode, url}) do
 | 
						||
    url = Pleroma.Web.MediaProxy.url(url)
 | 
						||
    {:ok, response} = Pleroma.HTTP.get(url)
 | 
						||
    size_limit = Config.get([:mrf_steal_emoji, :size_limit], 50_000)
 | 
						||
 | 
						||
    if byte_size(response.body) <= size_limit do
 | 
						||
      emoji_dir_path =
 | 
						||
        Config.get(
 | 
						||
          [:mrf_steal_emoji, :path],
 | 
						||
          Path.join(Config.get([:instance, :static_dir]), "emoji/stolen")
 | 
						||
        )
 | 
						||
 | 
						||
      extension =
 | 
						||
        url
 | 
						||
        |> URI.parse()
 | 
						||
        |> Map.get(:path)
 | 
						||
        |> Path.basename()
 | 
						||
        |> Path.extname()
 | 
						||
 | 
						||
      file_path = Path.join([emoji_dir_path, shortcode <> (extension || ".png")])
 | 
						||
 | 
						||
      try do
 | 
						||
        :ok = File.write(file_path, response.body)
 | 
						||
 | 
						||
        shortcode
 | 
						||
      rescue
 | 
						||
        e ->
 | 
						||
          Logger.warn("MRF.StealEmojiPolicy: Failed to write to #{file_path}: #{inspect(e)}")
 | 
						||
          nil
 | 
						||
      end
 | 
						||
    else
 | 
						||
      Logger.debug(
 | 
						||
        "MRF.StealEmojiPolicy: :#{shortcode}: at #{url} (#{byte_size(response.body)} B) over size limit (#{
 | 
						||
          size_limit
 | 
						||
        } B)"
 | 
						||
      )
 | 
						||
 | 
						||
      nil
 | 
						||
    end
 | 
						||
  rescue
 | 
						||
    e ->
 | 
						||
      Logger.warn("MRF.StealEmojiPolicy: Failed to fetch #{url}: #{inspect(e)}")
 | 
						||
      nil
 | 
						||
  end
 | 
						||
 | 
						||
  @impl true
 | 
						||
  def filter(%{"object" => %{"emoji" => foreign_emojis, "actor" => actor}} = message) do
 | 
						||
    host = URI.parse(actor).host
 | 
						||
 | 
						||
    if remote_host?(host) and accept_host?(host) do
 | 
						||
      installed_emoji = Pleroma.Emoji.get_all() |> Enum.map(fn {k, _} -> k end)
 | 
						||
 | 
						||
      new_emojis =
 | 
						||
        foreign_emojis
 | 
						||
        |> Enum.filter(fn {shortcode, _url} -> shortcode not in installed_emoji end)
 | 
						||
        |> Enum.filter(fn {shortcode, _url} ->
 | 
						||
          reject_emoji? =
 | 
						||
            Config.get([:mrf_steal_emoji, :rejected_shortcodes], [])
 | 
						||
            |> Enum.find(false, fn regex -> String.match?(shortcode, regex) end)
 | 
						||
 | 
						||
          !reject_emoji?
 | 
						||
        end)
 | 
						||
        |> Enum.map(&steal_emoji(&1))
 | 
						||
        |> Enum.filter(& &1)
 | 
						||
 | 
						||
      if !Enum.empty?(new_emojis) do
 | 
						||
        Logger.info("Stole new emojis: #{inspect(new_emojis)}")
 | 
						||
        Pleroma.Emoji.reload()
 | 
						||
      end
 | 
						||
    end
 | 
						||
 | 
						||
    {:ok, message}
 | 
						||
  end
 | 
						||
 | 
						||
  def filter(message), do: {:ok, message}
 | 
						||
 | 
						||
  @impl true
 | 
						||
  def describe do
 | 
						||
    {:ok, %{}}
 | 
						||
  end
 | 
						||
end
 |