git.squeep.com Git - akkoma/blob - lib/pleroma/web/plugs/remote_ip.ex

   1 # Pleroma: A lightweight social networking server
   2 # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
   3 # SPDX-License-Identifier: AGPL-3.0-only
   4
   5 defmodule Pleroma.Web.Plugs.RemoteIp do
   6   @moduledoc """
   7   This is a shim to call [`RemoteIp`](https://git.pleroma.social/pleroma/remote_ip) but with runtime configuration.
   8   """
   9
  10   alias Pleroma.Config
  11
  12   @behaviour Plug
  13
  14   def init(_), do: nil
  15
  16   def call(%{remote_ip: original_remote_ip} = conn, _) do
  17     if Config.get([__MODULE__, :enabled]) do
  18       {headers, proxies} = remote_ip_opts()
  19       new_remote_ip = RemoteIp.from(conn.req_headers, headers: headers, proxies: proxies)
  20
  21       if new_remote_ip != original_remote_ip do
  22         Map.put(conn, :remote_ip, new_remote_ip)
  23       else
  24         conn
  25       end
  26     else
  27       conn
  28     end
  29   end
  30
  31   defp remote_ip_opts do
  32     headers = Config.get([__MODULE__, :headers], [])
  33     reserved = Config.get([__MODULE__, :reserved], [])
  34
  35     proxies =
  36       Config.get([__MODULE__, :proxies], [])
  37       |> Enum.concat(reserved)
  38       |> Enum.map(&maybe_add_cidr/1)
  39
  40     {headers, proxies}
  41   end
  42
  43   defp maybe_add_cidr(proxy) when is_binary(proxy) do
  44     cond do
  45       "/" in String.codepoints(proxy) -> proxy
  46       InetCidr.v4?(InetCidr.parse_address!(proxy)) -> proxy <> "/32"
  47       InetCidr.v6?(InetCidr.parse_address!(proxy)) -> proxy <> "/128"
  48     end
  49   end
  50 end