MRF NoEmptyPolicy: Deny posts from local users if there is no content or only mentions.

Helps prevent accidental button mashes from submitting incomplete posts
This commit is contained in:
Mark Felder 2021-02-08 15:32:47 -06:00
parent d7262f7d22
commit 55a13fc360
3 changed files with 216 additions and 0 deletions

View file

@ -49,6 +49,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
- Ability to set ActivityPub aliases for follower migration.
- Configurable background job limits for RichMedia (link previews) and MediaProxyWarmingPolicy
- Ability to define custom HTTP headers per each frontend
- MRF (`NoEmptyPolicy`): New MRF Policy which will deny empty statuses or statuses of only mentions from being created by local users
<details>
<summary>API Changes</summary>

View file

@ -0,0 +1,61 @@
# Pleroma: A lightweight social networking server
# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.ActivityPub.MRF.NoEmptyPolicy do
@moduledoc "Filter local activities which have no content"
@behaviour Pleroma.Web.ActivityPub.MRF
alias Pleroma.Web
@impl true
def filter(%{"actor" => actor} = object) do
with true <- is_local?(actor),
true <- is_note?(object),
false <- has_attachment?(object),
true <- only_mentions?(object) do
{:reject, "[NoEmptyPolicy]"}
else
_ ->
{:ok, object}
end
end
def filter(object), do: {:ok, object}
defp is_local?(actor) do
if actor |> String.starts_with?("#{Web.base_url()}") do
true
else
false
end
end
defp has_attachment?(%{
"type" => "Create",
"object" => %{"type" => "Note", "attachment" => attachments}
})
when length(attachments) > 0,
do: true
defp has_attachment?(_), do: false
defp only_mentions?(%{"type" => "Create", "object" => %{"type" => "Note", "source" => source}}) do
non_mentions =
source |> String.split() |> Enum.filter(&(not String.starts_with?(&1, "@"))) |> length
if non_mentions > 0 do
false
else
true
end
end
defp only_mentions?(_), do: false
defp is_note?(%{"type" => "Create", "object" => %{"type" => "Note"}}), do: true
defp is_note?(_), do: false
@impl true
def describe, do: {:ok, %{}}
end

View file

@ -0,0 +1,154 @@
# Pleroma: A lightweight social networking server
# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.ActivityPub.MRF.NoEmptyPolicyTest do
use Pleroma.DataCase
alias Pleroma.Web.ActivityPub.MRF.NoEmptyPolicy
setup_all do: clear_config([:mrf, :policies], [Pleroma.Web.ActivityPub.MRF.NoEmptyPolicy])
test "Notes with content are exempt" do
message = %{
"actor" => "http://localhost:4001/users/testuser",
"cc" => ["http://localhost:4001/users/testuser/followers"],
"object" => %{
"actor" => "http://localhost:4001/users/testuser",
"attachment" => [],
"cc" => ["http://localhost:4001/users/testuser/followers"],
"source" => "this is a test post",
"to" => ["https://www.w3.org/ns/activitystreams#Public"],
"type" => "Note"
},
"to" => ["https://www.w3.org/ns/activitystreams#Public"],
"type" => "Create"
}
assert NoEmptyPolicy.filter(message) == {:ok, message}
end
test "Polls are exempt" do
message = %{
"actor" => "http://localhost:4001/users/testuser",
"cc" => ["http://localhost:4001/users/testuser/followers"],
"object" => %{
"actor" => "http://localhost:4001/users/testuser",
"attachment" => [],
"cc" => ["http://localhost:4001/users/testuser/followers"],
"oneOf" => [
%{
"name" => "chocolate",
"replies" => %{"totalItems" => 0, "type" => "Collection"},
"type" => "Note"
},
%{
"name" => "vanilla",
"replies" => %{"totalItems" => 0, "type" => "Collection"},
"type" => "Note"
}
],
"source" => "@user2",
"to" => [
"https://www.w3.org/ns/activitystreams#Public",
"http://localhost:4001/users/user2"
],
"type" => "Question"
},
"to" => [
"https://www.w3.org/ns/activitystreams#Public",
"http://localhost:4001/users/user2"
],
"type" => "Create"
}
assert NoEmptyPolicy.filter(message) == {:ok, message}
end
test "Notes with attachments are exempt" do
message = %{
"actor" => "http://localhost:4001/users/testuser",
"cc" => ["http://localhost:4001/users/testuser/followers"],
"object" => %{
"actor" => "http://localhost:4001/users/testuser",
"attachment" => [
%{
"actor" => "http://localhost:4001/users/testuser",
"mediaType" => "image/png",
"name" => "",
"type" => "Document",
"url" => [
%{
"href" =>
"http://localhost:4001/media/68ba231cf12e1382ce458f1979969f8ed5cc07ba198a02e653464abaf39bdb90.png",
"mediaType" => "image/png",
"type" => "Link"
}
]
}
],
"cc" => ["http://localhost:4001/users/testuser/followers"],
"source" => "@user2",
"to" => [
"https://www.w3.org/ns/activitystreams#Public",
"http://localhost:4001/users/user2"
],
"type" => "Note"
},
"to" => [
"https://www.w3.org/ns/activitystreams#Public",
"http://localhost:4001/users/user2"
],
"type" => "Create"
}
assert NoEmptyPolicy.filter(message) == {:ok, message}
end
test "Notes with only mentions are denied" do
message = %{
"actor" => "http://localhost:4001/users/testuser",
"cc" => ["http://localhost:4001/users/testuser/followers"],
"object" => %{
"actor" => "http://localhost:4001/users/testuser",
"attachment" => [],
"cc" => ["http://localhost:4001/users/testuser/followers"],
"source" => "@user2",
"to" => [
"https://www.w3.org/ns/activitystreams#Public",
"http://localhost:4001/users/user2"
],
"type" => "Note"
},
"to" => [
"https://www.w3.org/ns/activitystreams#Public",
"http://localhost:4001/users/user2"
],
"type" => "Create"
}
assert NoEmptyPolicy.filter(message) == {:reject, "[NoEmptyPolicy]"}
end
test "Notes with no content are denied" do
message = %{
"actor" => "http://localhost:4001/users/testuser",
"cc" => ["http://localhost:4001/users/testuser/followers"],
"object" => %{
"actor" => "http://localhost:4001/users/testuser",
"attachment" => [],
"cc" => ["http://localhost:4001/users/testuser/followers"],
"source" => "",
"to" => [
"https://www.w3.org/ns/activitystreams#Public"
],
"type" => "Note"
},
"to" => [
"https://www.w3.org/ns/activitystreams#Public"
],
"type" => "Create"
}
assert NoEmptyPolicy.filter(message) == {:reject, "[NoEmptyPolicy]"}
end
end