defmodule Pleroma.Web.MediaProxy.MediaProxyController do use Pleroma.Web, :controller require Logger @max_body_length 25 * 1048576 @cache_control %{ default: "public, max-age=1209600", error: "public, must-revalidate, max-age=160", } def remote(conn, %{"sig" => sig, "url" => url}) do config = Application.get_env(:pleroma, :media_proxy, []) with \ true <- Keyword.get(config, :enabled, false), {:ok, url} <- Pleroma.Web.MediaProxy.decode_url(sig, url), url = URI.encode(url), {:ok, content_type, body} <- proxy_request(url) do conn |> put_resp_content_type(content_type) |> set_cache_header(:default) |> send_resp(200, body) else false -> send_error(conn, 404) {:error, :invalid_signature} -> send_error(conn, 403) {:error, {:http, _, url}} -> redirect_or_error(conn, url, Keyword.get(config, :redirect_on_failure, true)) end end defp proxy_request(link) do headers = [{"user-agent", "Pleroma/MediaProxy; #{Pleroma.Web.base_url()} <#{Application.get_env(:pleroma, :instance)[:email]}>"}] options = [:insecure, {:follow_redirect, true}] with \ {:ok, 200, headers, client} <- :hackney.request(:get, link, headers, "", options), headers = Enum.into(headers, Map.new), {:ok, body} <- proxy_request_body(client), content_type <- proxy_request_content_type(headers, body) do {:ok, content_type, body} else {:ok, status, _, _} -> Logger.warn "MediaProxy: request failed, status #{status}, link: #{link}" {:error, {:http, :bad_status, link}} {:error, error} -> Logger.warn "MediaProxy: request failed, error #{inspect error}, link: #{link}" {:error, {:http, error, link}} end end defp set_cache_header(conn, key) do Plug.Conn.put_resp_header(conn, "cache-control", @cache_control[key]) end defp redirect_or_error(conn, url, true), do: redirect(conn, external: url) defp redirect_or_error(conn, url, _), do: send_error(conn, 502, "Media proxy error: " <> url) defp send_error(conn, code, body \\ "") do conn |> set_cache_header(:error) |> send_resp(code, body) end defp proxy_request_body(client), do: proxy_request_body(client, <<>>) defp proxy_request_body(client, body) when byte_size(body) < @max_body_length do case :hackney.stream_body(client) do {:ok, data} -> proxy_request_body(client, <>) :done -> {:ok, body} {:error, reason} -> {:error, reason} end end defp proxy_request_body(client, _) do :hackney.close(client) {:error, :body_too_large} end # TODO: the body is passed here as well because some hosts do not provide a content-type. # At some point we may want to use magic numbers to discover the content-type and reply a proper one. defp proxy_request_content_type(headers, _body) do headers["Content-Type"] || headers["content-type"] || "image/jpeg" end end