# Pleroma: A lightweight social networking server # Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Web.RichMedia.Helpers do alias Pleroma.Activity alias Pleroma.Config alias Pleroma.HTML alias Pleroma.Object alias Pleroma.Web.RichMedia.Parser @options [ pool: :media, max_body: 2_000_000, recv_timeout: 2_000 ] @spec validate_page_url(URI.t() | binary()) :: :ok | :error defp validate_page_url(page_url) when is_binary(page_url) do validate_tld = Config.get([Pleroma.Formatter, :validate_tld]) page_url |> Linkify.Parser.url?(validate_tld: validate_tld) |> parse_uri(page_url) end defp validate_page_url(%URI{host: host, scheme: "https", authority: authority}) when is_binary(authority) do cond do host in Config.get([:rich_media, :ignore_hosts], []) -> :error get_tld(host) in Config.get([:rich_media, :ignore_tld], []) -> :error true -> :ok end end defp validate_page_url(_), do: :error defp parse_uri(true, url) do url |> URI.parse() |> validate_page_url end defp parse_uri(_, _), do: :error defp get_tld(host) do host |> String.split(".") |> Enum.reverse() |> hd end def fetch_data_for_object(object) do with true <- Config.get([:rich_media, :enabled]), {:ok, page_url} <- HTML.extract_first_external_url_from_object(object), :ok <- validate_page_url(page_url), {:ok, rich_media} <- Parser.parse(page_url) do %{page_url: page_url, rich_media: rich_media} else _ -> %{} end end def fetch_data_for_activity(%Activity{data: %{"type" => "Create"}} = activity) do with true <- Config.get([:rich_media, :enabled]), %Object{} = object <- Object.normalize(activity, fetch: false) do fetch_data_for_object(object) else _ -> %{} end end def fetch_data_for_activity(_), do: %{} def rich_media_get(url) do headers = [{"user-agent", Pleroma.Application.user_agent() <> "; Bot"}] head_check = case Pleroma.HTTP.head(url, headers, @options) do # If the HEAD request didn't reach the server for whatever reason, # we assume the GET that comes right after won't either {:error, _} = e -> e {:ok, %Tesla.Env{status: 200, headers: headers}} -> with :ok <- check_content_type(headers), :ok <- check_content_length(headers), do: :ok _ -> :ok end with :ok <- head_check, do: Pleroma.HTTP.get(url, headers, @options) end defp check_content_type(headers) do case List.keyfind(headers, "content-type", 0) do {_, content_type} -> case Plug.Conn.Utils.media_type(content_type) do {:ok, "text", "html", _} -> :ok _ -> {:error, {:content_type, content_type}} end _ -> :ok end end @max_body @options[:max_body] defp check_content_length(headers) do case List.keyfind(headers, "content-length", 0) do {_, maybe_content_length} -> case Integer.parse(maybe_content_length) do {content_length, ""} when content_length <= @max_body -> :ok {_, ""} -> {:error, :body_too_large} _ -> :ok end _ -> :ok end end end