pleroma

activity_pub_controller.ex (16734B)

# Pleroma: A lightweight social networking server
# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.ActivityPub.ActivityPubController do
  use Pleroma.Web, :controller
  alias Pleroma.Activity
  alias Pleroma.Delivery
  alias Pleroma.Object
  alias Pleroma.Object.Fetcher
  alias Pleroma.User
  alias Pleroma.Web.ActivityPub.ActivityPub
  alias Pleroma.Web.ActivityPub.InternalFetchActor
  alias Pleroma.Web.ActivityPub.ObjectView
  alias Pleroma.Web.ActivityPub.Pipeline
  alias Pleroma.Web.ActivityPub.Relay
  alias Pleroma.Web.ActivityPub.Transmogrifier
  alias Pleroma.Web.ActivityPub.UserView
  alias Pleroma.Web.ActivityPub.Utils
  alias Pleroma.Web.ActivityPub.Visibility
  alias Pleroma.Web.ControllerHelper
  alias Pleroma.Web.Endpoint
  alias Pleroma.Web.Federator
  alias Pleroma.Web.Plugs.EnsureAuthenticatedPlug
  alias Pleroma.Web.Plugs.FederatingPlug
  require Logger
  action_fallback(:errors)
  @federating_only_actions [:internal_fetch, :relay, :relay_following, :relay_followers]
  plug(FederatingPlug when action in @federating_only_actions)
  plug(
    EnsureAuthenticatedPlug,
    [unless_func: &FederatingPlug.federating?/1] when action not in @federating_only_actions
  )
  # Note: :following and :followers must be served even without authentication (as via :api)
  plug(
    EnsureAuthenticatedPlug
    when action in [:read_inbox, :update_outbox, :whoami, :upload_media]
  )
  plug(Majic.Plug, [pool: Pleroma.MajicPool] when action in [:upload_media])
  plug(
    Pleroma.Web.Plugs.Cache,
    [query_params: false, tracking_fun: &__MODULE__.track_object_fetch/2]
    when action in [:activity, :object]
  )
  plug(:set_requester_reachable when action in [:inbox])
  plug(:relay_active? when action in [:relay])
  defp relay_active?(conn, _) do
    if Pleroma.Config.get([:instance, :allow_relay]) do
      conn
    else
      conn
      |> render_error(:not_found, "not found")
      |> halt()
    end
  end
  def user(conn, %{"nickname" => nickname}) do
    with %User{local: true} = user <- User.get_cached_by_nickname(nickname) do
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("user.json", %{user: user})
    else
      nil -> {:error, :not_found}
      %{local: false} -> {:error, :not_found}
    end
  end
  def object(%{assigns: assigns} = conn, _) do
    with ap_id <- Endpoint.url() <> conn.request_path,
         %Object{} = object <- Object.get_cached_by_ap_id(ap_id),
         user <- Map.get(assigns, :user, nil),
         {_, true} <- {:visible?, Visibility.visible_for_user?(object, user)} do
      conn
      |> maybe_skip_cache(user)
      |> assign(:tracking_fun_data, object.id)
      |> set_cache_ttl_for(object)
      |> put_resp_content_type("application/activity+json")
      |> put_view(ObjectView)
      |> render("object.json", object: object)
    else
      {:visible?, false} -> {:error, :not_found}
      nil -> {:error, :not_found}
    end
  end
  def track_object_fetch(conn, nil), do: conn
  def track_object_fetch(conn, object_id) do
    with %{assigns: %{user: %User{id: user_id}}} <- conn do
      Delivery.create(object_id, user_id)
    end
    conn
  end
  def activity(%{assigns: assigns} = conn, _) do
    with ap_id <- Endpoint.url() <> conn.request_path,
         %Activity{} = activity <- Activity.normalize(ap_id),
         {_, true} <- {:local?, activity.local},
         user <- Map.get(assigns, :user, nil),
         {_, true} <- {:visible?, Visibility.visible_for_user?(activity, user)} do
      conn
      |> maybe_skip_cache(user)
      |> maybe_set_tracking_data(activity)
      |> set_cache_ttl_for(activity)
      |> put_resp_content_type("application/activity+json")
      |> put_view(ObjectView)
      |> render("object.json", object: activity)
    else
      {:visible?, false} -> {:error, :not_found}
      {:local?, false} -> {:error, :not_found}
      nil -> {:error, :not_found}
    end
  end
  defp maybe_set_tracking_data(conn, %Activity{data: %{"type" => "Create"}} = activity) do
    object_id = Object.normalize(activity, fetch: false).id
    assign(conn, :tracking_fun_data, object_id)
  end
  defp maybe_set_tracking_data(conn, _activity), do: conn
  defp set_cache_ttl_for(conn, %Activity{object: object}) do
    set_cache_ttl_for(conn, object)
  end
  defp set_cache_ttl_for(conn, entity) do
    ttl =
      case entity do
        %Object{data: %{"type" => "Question"}} ->
          Pleroma.Config.get([:web_cache_ttl, :activity_pub_question])
        %Object{} ->
          Pleroma.Config.get([:web_cache_ttl, :activity_pub])
        _ ->
          nil
      end
    assign(conn, :cache_ttl, ttl)
  end
  def maybe_skip_cache(conn, user) do
    if user do
      conn
      |> assign(:skip_cache, true)
    else
      conn
    end
  end
  # GET /relay/following
  def relay_following(conn, _params) do
    with %{halted: false} = conn <- FederatingPlug.call(conn, []) do
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("following.json", %{user: Relay.get_actor()})
    end
  end
  def following(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname, "page" => page}) do
    with %User{} = user <- User.get_cached_by_nickname(nickname),
         {:show_follows, true} <-
           {:show_follows, (for_user && for_user == user) || !user.hide_follows} do
      {page, _} = Integer.parse(page)
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("following.json", %{user: user, page: page, for: for_user})
    else
      {:show_follows, _} ->
        conn
        |> put_resp_content_type("application/activity+json")
        |> send_resp(403, "")
    end
  end
  def following(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname}) do
    with %User{} = user <- User.get_cached_by_nickname(nickname) do
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("following.json", %{user: user, for: for_user})
    end
  end
  # GET /relay/followers
  def relay_followers(conn, _params) do
    with %{halted: false} = conn <- FederatingPlug.call(conn, []) do
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("followers.json", %{user: Relay.get_actor()})
    end
  end
  def followers(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname, "page" => page}) do
    with %User{} = user <- User.get_cached_by_nickname(nickname),
         {:show_followers, true} <-
           {:show_followers, (for_user && for_user == user) || !user.hide_followers} do
      {page, _} = Integer.parse(page)
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("followers.json", %{user: user, page: page, for: for_user})
    else
      {:show_followers, _} ->
        conn
        |> put_resp_content_type("application/activity+json")
        |> send_resp(403, "")
    end
  end
  def followers(%{assigns: %{user: for_user}} = conn, %{"nickname" => nickname}) do
    with %User{} = user <- User.get_cached_by_nickname(nickname) do
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("followers.json", %{user: user, for: for_user})
    end
  end
  def outbox(
        %{assigns: %{user: for_user}} = conn,
        %{"nickname" => nickname, "page" => page?} = params
      )
      when page? in [true, "true"] do
    with %User{} = user <- User.get_cached_by_nickname(nickname) do
      # "include_poll_votes" is a hack because postgres generates inefficient
      # queries when filtering by 'Answer', poll votes will be hidden by the
      # visibility filter in this case anyway
      params =
        params
        |> Map.drop(["nickname", "page"])
        |> Map.put("include_poll_votes", true)
        |> Map.new(fn {k, v} -> {String.to_existing_atom(k), v} end)
      activities = ActivityPub.fetch_user_activities(user, for_user, params)
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("activity_collection_page.json", %{
        activities: activities,
        pagination: ControllerHelper.get_pagination_fields(conn, activities),
        iri: "#{user.ap_id}/outbox"
      })
    end
  end
  def outbox(conn, %{"nickname" => nickname}) do
    with %User{} = user <- User.get_cached_by_nickname(nickname) do
      conn
      |> put_resp_content_type("application/activity+json")
      |> put_view(UserView)
      |> render("activity_collection.json", %{iri: "#{user.ap_id}/outbox"})
    end
  end
  def inbox(%{assigns: %{valid_signature: true}} = conn, %{"nickname" => nickname} = params) do
    with %User{is_active: true} = recipient <- User.get_cached_by_nickname(nickname),
         {:ok, %User{is_active: true} = actor} <- User.get_or_fetch_by_ap_id(params["actor"]),
         true <- Utils.recipient_in_message(recipient, actor, params),
         params <- Utils.maybe_splice_recipient(recipient.ap_id, params) do
      Federator.incoming_ap_doc(params)
      json(conn, "ok")
    else
      _ ->
        conn
        |> put_status(:bad_request)
        |> json("Invalid request.")
    end
  end
  def inbox(%{assigns: %{valid_signature: true}} = conn, params) do
    Federator.incoming_ap_doc(params)
    json(conn, "ok")
  end
  def inbox(%{assigns: %{valid_signature: false}, req_headers: req_headers} = conn, params) do
    Federator.incoming_ap_doc(%{req_headers: req_headers, params: params})
    json(conn, "ok")
  end
  # POST /relay/inbox -or- POST /internal/fetch/inbox
  def inbox(conn, %{"type" => "Create"} = params) do
    if FederatingPlug.federating?() do
      post_inbox_relayed_create(conn, params)
    else
      conn
      |> put_status(:bad_request)
      |> json("Not federating")
    end
  end
  def inbox(conn, _params) do
    conn
    |> put_status(:bad_request)
    |> json("error, missing HTTP Signature")
  end
  defp post_inbox_relayed_create(conn, params) do
    Logger.debug(
      "Signature missing or not from author, relayed Create message, fetching object from source"
    )
    Fetcher.fetch_object_from_id(params["object"]["id"])
    json(conn, "ok")
  end
  defp represent_service_actor(%User{} = user, conn) do
    conn
    |> put_resp_content_type("application/activity+json")
    |> put_view(UserView)
    |> render("user.json", %{user: user})
  end
  defp represent_service_actor(nil, _), do: {:error, :not_found}
  def relay(conn, _params) do
    Relay.get_actor()
    |> represent_service_actor(conn)
  end
  def internal_fetch(conn, _params) do
    InternalFetchActor.get_actor()
    |> represent_service_actor(conn)
  end
  @doc "Returns the authenticated user's ActivityPub User object or a 404 Not Found if non-authenticated"
  def whoami(%{assigns: %{user: %User{} = user}} = conn, _params) do
    conn
    |> put_resp_content_type("application/activity+json")
    |> put_view(UserView)
    |> render("user.json", %{user: user})
  end
  def read_inbox(
        %{assigns: %{user: %User{nickname: nickname} = user}} = conn,
        %{"nickname" => nickname, "page" => page?} = params
      )
      when page? in [true, "true"] do
    params =
      params
      |> Map.drop(["nickname", "page"])
      |> Map.put("blocking_user", user)
      |> Map.put("user", user)
      |> Map.new(fn {k, v} -> {String.to_existing_atom(k), v} end)
    activities =
      [user.ap_id | User.following(user)]
      |> ActivityPub.fetch_activities(params)
      |> Enum.reverse()
    conn
    |> put_resp_content_type("application/activity+json")
    |> put_view(UserView)
    |> render("activity_collection_page.json", %{
      activities: activities,
      pagination: ControllerHelper.get_pagination_fields(conn, activities),
      iri: "#{user.ap_id}/inbox"
    })
  end
  def read_inbox(%{assigns: %{user: %User{nickname: nickname} = user}} = conn, %{
        "nickname" => nickname
      }) do
    conn
    |> put_resp_content_type("application/activity+json")
    |> put_view(UserView)
    |> render("activity_collection.json", %{iri: "#{user.ap_id}/inbox"})
  end
  def read_inbox(%{assigns: %{user: %User{nickname: as_nickname}}} = conn, %{
        "nickname" => nickname
      }) do
    err =
      dgettext("errors", "can't read inbox of %{nickname} as %{as_nickname}",
        nickname: nickname,
        as_nickname: as_nickname
      )
    conn
    |> put_status(:forbidden)
    |> json(err)
  end
  defp fix_user_message(%User{ap_id: actor}, %{"type" => "Create", "object" => object} = activity)
       when is_map(object) do
    length =
      [object["content"], object["summary"], object["name"]]
      |> Enum.filter(&is_binary(&1))
      |> Enum.join("")
      |> String.length()
    limit = Pleroma.Config.get([:instance, :limit])
    if length < limit do
      object =
        object
        |> Transmogrifier.strip_internal_fields()
        |> Map.put("attributedTo", actor)
        |> Map.put("actor", actor)
        |> Map.put("id", Utils.generate_object_id())
        |> Map.put("published", Utils.make_date())
      {:ok, Map.put(activity, "object", object)}
    else
      {:error,
       dgettext(
         "errors",
         "Character limit (%{limit} characters) exceeded, contains %{length} characters",
         limit: limit,
         length: length
       )}
    end
  end
  defp fix_user_message(
         %User{ap_id: actor} = user,
         %{"type" => "Delete", "object" => object} = activity
       ) do
    with {_, %Object{data: object_data}} <- {:normalize, Object.normalize(object, fetch: false)},
         {_, true} <- {:permission, user.is_moderator || actor == object_data["actor"]} do
      {:ok, activity}
    else
      {:normalize, _} ->
        {:error, "No such object found"}
      {:permission, _} ->
        {:forbidden, "You can't delete this object"}
    end
  end
  defp fix_user_message(%User{}, activity) do
    {:ok, activity}
  end
  def update_outbox(
        %{assigns: %{user: %User{nickname: nickname, ap_id: actor} = user}} = conn,
        %{"nickname" => nickname} = params
      ) do
    params =
      params
      |> Map.drop(["nickname"])
      |> Map.put("id", Utils.generate_activity_id())
      |> Map.put("actor", actor)
      |> Map.put("published", Utils.make_date())
    with {:ok, params} <- fix_user_message(user, params),
         {:ok, activity, _} <- Pipeline.common_pipeline(params, local: true),
         %Activity{data: activity_data} <- Activity.normalize(activity) do
      conn
      |> put_status(:created)
      |> put_resp_header("location", activity_data["id"])
      |> json(activity_data)
    else
      {:forbidden, message} ->
        conn
        |> put_status(:forbidden)
        |> json(message)
      {:error, message} ->
        conn
        |> put_status(:bad_request)
        |> json(message)
      e ->
        Logger.warning(fn -> "AP C2S: #{inspect(e)}" end)
        conn
        |> put_status(:bad_request)
        |> json("Bad Request")
    end
  end
  def update_outbox(%{assigns: %{user: %User{} = user}} = conn, %{"nickname" => nickname}) do
    err =
      dgettext("errors", "can't update outbox of %{nickname} as %{as_nickname}",
        nickname: nickname,
        as_nickname: user.nickname
      )
    conn
    |> put_status(:forbidden)
    |> json(err)
  end
  defp errors(conn, {:error, :not_found}) do
    conn
    |> put_status(:not_found)
    |> json(dgettext("errors", "Not found"))
  end
  defp errors(conn, _e) do
    conn
    |> put_status(:internal_server_error)
    |> json(dgettext("errors", "error"))
  end
  defp set_requester_reachable(%Plug.Conn{} = conn, _) do
    with actor <- conn.params["actor"],
         true <- is_binary(actor) do
      Pleroma.Instances.set_reachable(actor)
    end
    conn
  end
  def upload_media(%{assigns: %{user: %User{} = user}} = conn, %{"file" => file} = data) do
    with {:ok, object} <-
           ActivityPub.upload(
             file,
             actor: User.ap_id(user),
             description: Map.get(data, "description")
           ) do
      Logger.debug(inspect(object))
      conn
      |> put_status(:created)
      |> json(object.data)
    end
  end
  def pinned(conn, %{"nickname" => nickname}) do
    with %User{} = user <- User.get_cached_by_nickname(nickname) do
      conn
      |> put_resp_header("content-type", "application/activity+json")
      |> json(UserView.render("featured.json", %{user: user}))
    end
  end
end