akkoma/lib/pleroma/web/media_proxy/controller.ex

82 lines
2.9 KiB
Elixir

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),
{: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, <<body :: binary, data :: binary>>)
: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