270 lines
7.5 KiB
Elixir
270 lines
7.5 KiB
Elixir
# Pleroma: A lightweight social networking server
|
|
# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
|
|
# SPDX-License-Identifier: AGPL-3.0-only
|
|
|
|
defmodule Pleroma.Web.Plugs.RateLimiter do
|
|
@moduledoc """
|
|
|
|
## Configuration
|
|
|
|
A keyword list of rate limiters where a key is a limiter name and value is the limiter configuration.
|
|
The basic configuration is a tuple where:
|
|
|
|
* The first element: `scale` (Integer). The time scale in milliseconds.
|
|
* The second element: `limit` (Integer). How many requests to limit in the time scale provided.
|
|
|
|
It is also possible to have different limits for unauthenticated and authenticated users: the keyword value must be a
|
|
list of two tuples where the first one is a config for unauthenticated users and the second one is for authenticated.
|
|
|
|
To disable a limiter set its value to `nil`.
|
|
|
|
### Example
|
|
|
|
config :pleroma, :rate_limit,
|
|
one: {1000, 10},
|
|
two: [{10_000, 10}, {10_000, 50}],
|
|
foobar: nil
|
|
|
|
Here we have three limiters:
|
|
|
|
* `one` which is not over 10req/1s
|
|
* `two` which has two limits: 10req/10s for unauthenticated users and 50req/10s for authenticated users
|
|
* `foobar` which is disabled
|
|
|
|
## Usage
|
|
|
|
AllowedSyntax:
|
|
|
|
plug(Pleroma.Web.Plugs.RateLimiter, name: :limiter_name)
|
|
plug(Pleroma.Web.Plugs.RateLimiter, options) # :name is a required option
|
|
|
|
Allowed options:
|
|
|
|
* `name` required, always used to fetch the limit values from the config
|
|
* `bucket_name` overrides name for counting purposes (e.g. to have a separate limit for a set of actions)
|
|
* `params` appends values of specified request params (e.g. ["id"]) to bucket name
|
|
|
|
Inside a controller:
|
|
|
|
plug(Pleroma.Web.Plugs.RateLimiter, [name: :one] when action == :one)
|
|
plug(Pleroma.Web.Plugs.RateLimiter, [name: :two] when action in [:two, :three])
|
|
|
|
plug(
|
|
Pleroma.Web.Plugs.RateLimiter,
|
|
[name: :status_id_action, bucket_name: "status_id_action:fav_unfav", params: ["id"]]
|
|
when action in ~w(fav_status unfav_status)a
|
|
)
|
|
|
|
or inside a router pipeline:
|
|
|
|
pipeline :api do
|
|
...
|
|
plug(Pleroma.Web.Plugs.RateLimiter, name: :one)
|
|
...
|
|
end
|
|
"""
|
|
import Pleroma.Web.TranslationHelpers
|
|
import Plug.Conn
|
|
|
|
alias Pleroma.Config
|
|
alias Pleroma.User
|
|
alias Pleroma.Web.Plugs.RateLimiter.LimiterSupervisor
|
|
|
|
require Logger
|
|
|
|
@cachex Pleroma.Config.get([:cachex, :provider], Cachex)
|
|
|
|
@doc false
|
|
def init(plug_opts) do
|
|
plug_opts
|
|
end
|
|
|
|
def call(conn, plug_opts) do
|
|
if disabled?(conn) do
|
|
handle_disabled(conn)
|
|
else
|
|
action_settings = action_settings(plug_opts)
|
|
handle(conn, action_settings)
|
|
end
|
|
end
|
|
|
|
defp handle_disabled(conn) do
|
|
Logger.warn(
|
|
"Rate limiter disabled due to forwarded IP not being found. Please ensure your reverse proxy is providing the X-Forwarded-For header or disable the RemoteIP plug/rate limiter."
|
|
)
|
|
|
|
conn
|
|
end
|
|
|
|
defp handle(conn, nil), do: conn
|
|
|
|
defp handle(conn, action_settings) do
|
|
action_settings
|
|
|> incorporate_conn_info(conn)
|
|
|> check_rate()
|
|
|> case do
|
|
{:ok, _count} ->
|
|
conn
|
|
|
|
{:error, _count} ->
|
|
render_throttled_error(conn)
|
|
end
|
|
end
|
|
|
|
def disabled?(conn) do
|
|
if Map.has_key?(conn.assigns, :remote_ip_found),
|
|
do: !conn.assigns.remote_ip_found,
|
|
else: false
|
|
end
|
|
|
|
@inspect_bucket_not_found {:error, :not_found}
|
|
|
|
def inspect_bucket(conn, bucket_name_root, plug_opts) do
|
|
with %{name: _} = action_settings <- action_settings(plug_opts) do
|
|
action_settings = incorporate_conn_info(action_settings, conn)
|
|
bucket_name = make_bucket_name(%{action_settings | name: bucket_name_root})
|
|
key_name = make_key_name(action_settings)
|
|
limit = get_limits(action_settings)
|
|
|
|
case @cachex.get(bucket_name, key_name) do
|
|
{:error, :no_cache} ->
|
|
@inspect_bucket_not_found
|
|
|
|
{:ok, nil} ->
|
|
{0, limit}
|
|
|
|
{:ok, value} ->
|
|
{value, limit - value}
|
|
end
|
|
else
|
|
_ -> @inspect_bucket_not_found
|
|
end
|
|
end
|
|
|
|
def action_settings(plug_opts) do
|
|
with limiter_name when is_atom(limiter_name) <- plug_opts[:name],
|
|
limits when not is_nil(limits) <- Config.get([:rate_limit, limiter_name]) do
|
|
bucket_name_root = Keyword.get(plug_opts, :bucket_name, limiter_name)
|
|
|
|
%{
|
|
name: bucket_name_root,
|
|
limits: limits,
|
|
opts: plug_opts
|
|
}
|
|
end
|
|
end
|
|
|
|
defp check_rate(action_settings) do
|
|
bucket_name = make_bucket_name(action_settings)
|
|
key_name = make_key_name(action_settings)
|
|
limit = get_limits(action_settings)
|
|
|
|
case @cachex.get_and_update(bucket_name, key_name, &increment_value(&1, limit)) do
|
|
{:commit, value} ->
|
|
{:ok, value}
|
|
|
|
{:ignore, value} ->
|
|
{:error, value}
|
|
|
|
{:error, :no_cache} ->
|
|
initialize_buckets!(action_settings)
|
|
check_rate(action_settings)
|
|
end
|
|
end
|
|
|
|
defp increment_value(nil, _limit), do: {:commit, 1}
|
|
|
|
defp increment_value(val, limit) when val >= limit, do: {:ignore, val}
|
|
|
|
defp increment_value(val, _limit), do: {:commit, val + 1}
|
|
|
|
defp incorporate_conn_info(action_settings, %{
|
|
assigns: %{user: %User{id: user_id}},
|
|
params: params
|
|
}) do
|
|
Map.merge(action_settings, %{
|
|
mode: :user,
|
|
conn_params: params,
|
|
conn_info: "#{user_id}"
|
|
})
|
|
end
|
|
|
|
defp incorporate_conn_info(action_settings, %{params: params} = conn) do
|
|
Map.merge(action_settings, %{
|
|
mode: :anon,
|
|
conn_params: params,
|
|
conn_info: "#{ip(conn)}"
|
|
})
|
|
end
|
|
|
|
defp ip(%{remote_ip: remote_ip}) do
|
|
remote_ip
|
|
|> Tuple.to_list()
|
|
|> Enum.join(".")
|
|
end
|
|
|
|
defp render_throttled_error(conn) do
|
|
conn
|
|
|> render_error(:too_many_requests, "Throttled")
|
|
|> halt()
|
|
end
|
|
|
|
defp make_key_name(action_settings) do
|
|
""
|
|
|> attach_selected_params(action_settings)
|
|
|> attach_identity(action_settings)
|
|
end
|
|
|
|
defp get_scale(_, {scale, _}), do: scale
|
|
|
|
defp get_scale(:anon, [{scale, _}, {_, _}]), do: scale
|
|
|
|
defp get_scale(:user, [{_, _}, {scale, _}]), do: scale
|
|
|
|
defp get_limits(%{limits: {_scale, limit}}), do: limit
|
|
|
|
defp get_limits(%{mode: :user, limits: [_, {_, limit}]}), do: limit
|
|
|
|
defp get_limits(%{limits: [{_, limit}, _]}), do: limit
|
|
|
|
defp make_bucket_name(%{mode: :user, name: bucket_name_root}),
|
|
do: user_bucket_name(bucket_name_root)
|
|
|
|
defp make_bucket_name(%{mode: :anon, name: bucket_name_root}),
|
|
do: anon_bucket_name(bucket_name_root)
|
|
|
|
defp attach_selected_params(input, %{conn_params: conn_params, opts: plug_opts}) do
|
|
params_string =
|
|
plug_opts
|
|
|> Keyword.get(:params, [])
|
|
|> Enum.sort()
|
|
|> Enum.map(&Map.get(conn_params, &1, ""))
|
|
|> Enum.join(":")
|
|
|
|
[input, params_string]
|
|
|> Enum.join(":")
|
|
|> String.replace_leading(":", "")
|
|
end
|
|
|
|
defp initialize_buckets!(%{name: _name, limits: nil}), do: :ok
|
|
|
|
defp initialize_buckets!(%{name: name, limits: limits}) do
|
|
{:ok, _pid} =
|
|
LimiterSupervisor.add_or_return_limiter(anon_bucket_name(name), get_scale(:anon, limits))
|
|
|
|
{:ok, _pid} =
|
|
LimiterSupervisor.add_or_return_limiter(user_bucket_name(name), get_scale(:user, limits))
|
|
|
|
:ok
|
|
end
|
|
|
|
defp attach_identity(base, %{mode: :user, conn_info: conn_info}),
|
|
do: "user:#{base}:#{conn_info}"
|
|
|
|
defp attach_identity(base, %{mode: :anon, conn_info: conn_info}),
|
|
do: "ip:#{base}:#{conn_info}"
|
|
|
|
defp user_bucket_name(bucket_name_root), do: "user:#{bucket_name_root}" |> String.to_atom()
|
|
defp anon_bucket_name(bucket_name_root), do: "anon:#{bucket_name_root}" |> String.to_atom()
|
|
end
|