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

97 lines
3.7 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.MediaProxy.MediaProxyController do
use Pleroma.Web, :controller
alias Pleroma.Config
alias Pleroma.Helpers.MogrifyHelper
alias Pleroma.ReverseProxy
alias Pleroma.Web.MediaProxy
@default_proxy_opts [max_body_length: 25 * 1_048_576, http: [follow_redirect: true]]
def remote(conn, %{"sig" => sig64, "url" => url64} = params) do
with config <- Config.get([:media_proxy], []),
{_, true} <- {:enabled, Keyword.get(config, :enabled, false)},
{:ok, url} <- MediaProxy.decode_url(sig64, url64),
:ok <- MediaProxy.filename_matches(params, conn.request_path, url) do
ReverseProxy.call(conn, url, Keyword.get(config, :proxy_opts, @default_proxy_opts))
else
{:enabled, false} ->
send_resp(conn, 404, Plug.Conn.Status.reason_phrase(404))
{:error, :invalid_signature} ->
send_resp(conn, 403, Plug.Conn.Status.reason_phrase(403))
{:wrong_filename, filename} ->
redirect(conn, external: MediaProxy.build_url(sig64, url64, filename))
end
end
def preview(conn, %{"sig" => sig64, "url" => url64} = params) do
with {_, true} <- {:enabled, Config.get([:media_preview_proxy, :enabled], false)},
{:ok, url} <- MediaProxy.decode_url(sig64, url64),
:ok <- MediaProxy.filename_matches(params, conn.request_path, url) do
handle_preview(conn, url)
else
{:enabled, false} ->
send_resp(conn, 404, Plug.Conn.Status.reason_phrase(404))
{:error, :invalid_signature} ->
send_resp(conn, 403, Plug.Conn.Status.reason_phrase(403))
{:wrong_filename, filename} ->
redirect(conn, external: MediaProxy.build_preview_url(sig64, url64, filename))
end
end
defp handle_preview(conn, url) do
with {:ok, %{status: status} = head_response} when status in 200..299 <- Tesla.head(url),
{_, true} <- {:acceptable_content_length, acceptable_body_length?(head_response)} do
content_type = Tesla.get_header(head_response, "content-type")
handle_preview(content_type, conn, url)
else
{_, %{status: status}} ->
send_resp(conn, :failed_dependency, "Can't fetch HTTP headers (HTTP #{status}).")
{:acceptable_content_length, false} ->
send_resp(conn, :unprocessable_entity, "Source file size exceeds limit.")
end
end
defp handle_preview("image/" <> _, %{params: params} = conn, url) do
with {:ok, %{status: status, body: body}} when status in 200..299 <- Tesla.get(url),
{:ok, path} <- MogrifyHelper.store_as_temporary_file(url, body),
resize_dimensions <-
Map.get(
params,
"limit_dimensions",
Config.get([:media_preview_proxy, :limit_dimensions])
),
%Mogrify.Image{} <- MogrifyHelper.in_place_resize_to_limit(path, resize_dimensions) do
send_file(conn, 200, path)
else
{_, %{status: _}} ->
send_resp(conn, :failed_dependency, "Can't fetch the image.")
_ ->
send_resp(conn, :failed_dependency, "Can't handle image preview.")
end
end
defp handle_preview(content_type, conn, _url) do
send_resp(conn, :unprocessable_entity, "Unsupported content type: #{content_type}.")
end
defp acceptable_body_length?(head_response) do
max_body_length = Config.get([:media_preview_proxy, :max_body_length], nil)
content_length = Tesla.get_header(head_response, "content-length")
content_length = with {int, _} <- Integer.parse(content_length), do: int
content_length == :error or
max_body_length in [nil, :infinity] or
content_length <= max_body_length
end
end