pleroma/lib/pleroma/web/mastodon_api/websocket_handler.ex

258 lines
7.9 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
require Logger
alias Pleroma.Repo
alias Pleroma.User
alias Pleroma.Web.OAuth.Token
alias Pleroma.Web.Streamer
alias Pleroma.Web.StreamerView
@behaviour :cowboy_websocket
# Client ping period.
@tick :timer.seconds(30)
# Cowboy timeout period.
@timeout :timer.seconds(60)
# Hibernate every X messages
@hibernate_every 100
def init(%{qs: qs} = req, state) do
with params <- Enum.into(:cow_qs.parse_qs(qs), %{}),
sec_websocket <- :cowboy_req.header("sec-websocket-protocol", req, nil),
access_token <- Map.get(params, "access_token"),
{:ok, user, oauth_token} <- authenticate_request(access_token, sec_websocket),
{:ok, topic} <- Streamer.get_topic(params["stream"], user, oauth_token, params) do
req =
if sec_websocket do
:cowboy_req.set_resp_header("sec-websocket-protocol", sec_websocket, req)
else
req
end
topics =
if topic do
[topic]
else
[]
end
{:cowboy_websocket, req,
%{user: user, topics: topics, oauth_token: oauth_token, count: 0, timer: nil},
%{idle_timeout: @timeout}}
else
{:error, :bad_topic} ->
Logger.debug("#{__MODULE__} bad topic #{inspect(req)}")
req = :cowboy_req.reply(404, req)
{:ok, req, state}
{:error, :unauthorized} ->
Logger.debug("#{__MODULE__} authentication error: #{inspect(req)}")
req = :cowboy_req.reply(401, req)
{:ok, req, state}
end
end
def websocket_init(state) do
Logger.debug(
"#{__MODULE__} accepted websocket connection for user #{(state.user || %{id: "anonymous"}).id}, topics #{state.topics}"
)
Enum.each(state.topics, fn topic -> Streamer.add_socket(topic, state.oauth_token) end)
{:ok, %{state | timer: timer()}}
end
# Client's Pong frame.
def websocket_handle(:pong, state) do
if state.timer, do: Process.cancel_timer(state.timer)
{:ok, %{state | timer: timer()}}
end
# We only receive pings for now
def websocket_handle(:ping, state), do: {:ok, state}
def websocket_handle({:text, text}, state) do
with {:ok, %{} = event} <- Jason.decode(text) do
handle_client_event(event, state)
else
_ ->
Logger.error("#{__MODULE__} received non-JSON event: #{inspect(text)}")
{:ok, state}
end
end
def websocket_handle(frame, state) do
Logger.error("#{__MODULE__} received frame: #{inspect(frame)}")
{:ok, state}
end
def websocket_info({:render_with_user, view, template, item, topic}, state) do
user = %User{} = User.get_cached_by_ap_id(state.user.ap_id)
unless Streamer.filtered_by_user?(user, item) do
websocket_info({:text, view.render(template, item, user, topic)}, %{state | user: user})
else
{:ok, state}
end
end
def websocket_info({:text, message}, state) do
# If the websocket processed X messages, force an hibernate/GC.
# We don't hibernate at every message to balance CPU usage/latency with RAM usage.
if state.count > @hibernate_every do
{:reply, {:text, message}, %{state | count: 0}, :hibernate}
else
{:reply, {:text, message}, %{state | count: state.count + 1}}
end
end
# Ping tick. We don't re-queue a timer there, it is instead queued when :pong is received.
# As we hibernate there, reset the count to 0.
# If the client misses :pong, Cowboy will automatically timeout the connection after
# `@idle_timeout`.
def websocket_info(:tick, state) do
{:reply, :ping, %{state | timer: nil, count: 0}, :hibernate}
end
def websocket_info(:close, state) do
{:stop, state}
end
# State can be `[]` only in case we terminate before switching to websocket,
# we already log errors for these cases in `init/1`, so just do nothing here
def terminate(_reason, _req, []), do: :ok
def terminate(reason, _req, state) do
Logger.debug(
"#{__MODULE__} terminating websocket connection for user #{(state.user || %{id: "anonymous"}).id}, topics #{state.topics || "?"}: #{inspect(reason)}"
)
Enum.each(state.topics, fn topic -> Streamer.remove_socket(topic) end)
:ok
end
# Public streams without authentication.
defp authenticate_request(nil, nil) do
{:ok, nil, nil}
end
# Authenticated streams.
defp authenticate_request(access_token, sec_websocket) do
token = access_token || sec_websocket
with true <- is_bitstring(token),
oauth_token = %Token{user_id: user_id} <- Repo.get_by(Token, token: token),
user = %User{} <- User.get_cached_by_id(user_id) do
{:ok, user, oauth_token}
else
_ -> {:error, :unauthorized}
end
end
defp timer do
Process.send_after(self(), :tick, @tick)
end
defp handle_client_event(%{"type" => "subscribe", "stream" => _topic} = params, state) do
with {_, {:ok, topic}} <-
{:topic, Streamer.get_topic(params["stream"], state.user, state.oauth_token, params)},
{_, false} <- {:subscribed, topic in state.topics} do
Streamer.add_socket(topic, state.oauth_token)
{[
{:text,
StreamerView.render("pleroma_respond.json", %{type: "subscribe", result: "success"})}
], %{state | topics: [topic | state.topics]}}
else
{:subscribed, true} ->
{[
{:text,
StreamerView.render("pleroma_respond.json", %{type: "subscribe", result: "ignored"})}
], state}
{:topic, {:error, error}} ->
{[
{:text,
StreamerView.render("pleroma_respond.json", %{
type: "subscribe",
result: "error",
error: error
})}
], state}
end
end
defp handle_client_event(%{"type" => "unsubscribe", "stream" => _topic} = params, state) do
with {_, {:ok, topic}} <-
{:topic, Streamer.get_topic(params["stream"], state.user, state.oauth_token, params)},
{_, true} <- {:subscribed, topic in state.topics} do
Streamer.remove_socket(topic)
{[
{:text,
StreamerView.render("pleroma_respond.json", %{type: "unsubscribe", result: "success"})}
], %{state | topics: List.delete(state.topics, topic)}}
else
{:subscribed, false} ->
{[
{:text,
StreamerView.render("pleroma_respond.json", %{type: "unsubscribe", result: "ignored"})}
], state}
{:topic, {:error, error}} ->
{[
{:text,
StreamerView.render("pleroma_respond.json", %{
type: "unsubscribe",
result: "error",
error: error
})}
], state}
end
end
defp handle_client_event(
%{"type" => "pleroma.authenticate", "token" => access_token} = _params,
state
) do
with {:auth, nil, nil} <- {:auth, state.user, state.oauth_token},
{:ok, user, oauth_token} <- authenticate_request(access_token, nil) do
{[
{:text,
StreamerView.render("pleroma_respond.json", %{
type: "pleroma.authenticate",
result: "success"
})}
], %{state | user: user, oauth_token: oauth_token}}
else
{:auth, _, _} ->
{[
{:text,
StreamerView.render("pleroma_respond.json", %{
type: "pleroma.authenticate",
result: "error",
error: :already_authenticated
})}
], state}
_ ->
{[
{:text,
StreamerView.render("pleroma_respond.json", %{
type: "pleroma.authenticate",
result: "error",
error: :unauthorized
})}
], state}
end
end
defp handle_client_event(params, state) do
Logger.error("#{__MODULE__} received unknown event: #{inspect(params)}")
{[], state}
end
end