1 files changed, 48 insertions, 0 deletions
diff --git a/lib/pleroma/web/plugs/remote_ip.ex b/lib/pleroma/web/plugs/remote_ip.ex
new file mode 100644
index 000000000..4d7daca56
--- /dev/null
+++ b/lib/pleroma/web/plugs/remote_ip.ex
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+# 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.RemoteIp do
+  @moduledoc """
+  This is a shim to call [`RemoteIp`](https://git.pleroma.social/pleroma/remote_ip) but with runtime configuration.
+  """
+
+  alias Pleroma.Config
+  import Plug.Conn
+
+  @behaviour Plug
+
+  def init(_), do: nil
+
+  def call(%{remote_ip: original_remote_ip} = conn, _) do
+    if Config.get([__MODULE__, :enabled]) do
+      %{remote_ip: new_remote_ip} = conn = RemoteIp.call(conn, remote_ip_opts())
+      assign(conn, :remote_ip_found, original_remote_ip != new_remote_ip)
+    else
+      conn
+    end
+  end
+
+  defp remote_ip_opts do
+    headers = Config.get([__MODULE__, :headers], []) |> MapSet.new()
+    reserved = Config.get([__MODULE__, :reserved], [])
+
+    proxies =
+      Config.get([__MODULE__, :proxies], [])
+      |> Enum.concat(reserved)
+      |> Enum.map(&maybe_add_cidr/1)
+
+    {headers, proxies}
+  end
+
+  defp maybe_add_cidr(proxy) when is_binary(proxy) do
+    proxy =
+      cond do
+        "/" in String.codepoints(proxy) -> proxy
+        InetCidr.v4?(InetCidr.parse_address!(proxy)) -> proxy <> "/32"
+        InetCidr.v6?(InetCidr.parse_address!(proxy)) -> proxy <> "/128"
+      end
+
+    InetCidr.parse(proxy, true)
+  end
+end