distraction.party/lib/pleroma/web/rich_media/helpers.ex

129 lines
3.3 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.RichMedia.Helpers do
alias Pleroma.Activity
alias Pleroma.Config
alias Pleroma.HTML
alias Pleroma.Object
alias Pleroma.Web.RichMedia.Parser
@options [
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