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Diffstat (limited to 'lib/pleroma/web.ex')
-rw-r--r-- | lib/pleroma/web.ex | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/lib/pleroma/web.ex b/lib/pleroma/web.ex new file mode 100644 index 000000000..7779826e3 --- /dev/null +++ b/lib/pleroma/web.ex @@ -0,0 +1,234 @@ +# Pleroma: A lightweight social networking server +# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> +# SPDX-License-Identifier: AGPL-3.0-only + +defmodule Pleroma.Web do + @moduledoc """ + A module that keeps using definitions for controllers, + views and so on. + + This can be used in your application as: + + use Pleroma.Web, :controller + use Pleroma.Web, :view + + The definitions below will be executed for every view, + controller, etc, so keep them short and clean, focused + on imports, uses and aliases. + + Do NOT define functions inside the quoted expressions + below. + """ + + alias Pleroma.Web.Plugs.EnsureAuthenticatedPlug + alias Pleroma.Web.Plugs.EnsurePublicOrAuthenticatedPlug + alias Pleroma.Web.Plugs.ExpectAuthenticatedCheckPlug + alias Pleroma.Web.Plugs.ExpectPublicOrAuthenticatedCheckPlug + alias Pleroma.Web.Plugs.OAuthScopesPlug + alias Pleroma.Web.Plugs.PlugHelper + + def controller do + quote do + use Phoenix.Controller, namespace: Pleroma.Web + + import Plug.Conn + + import Pleroma.Web.Gettext + import Pleroma.Web.Router.Helpers + import Pleroma.Web.TranslationHelpers + + plug(:set_put_layout) + + defp set_put_layout(conn, _) do + put_layout(conn, Pleroma.Config.get(:app_layout, "app.html")) + end + + # Marks plugs intentionally skipped and blocks their execution if present in plugs chain + defp skip_plug(conn, plug_modules) do + plug_modules + |> List.wrap() + |> Enum.reduce( + conn, + fn plug_module, conn -> + try do + plug_module.skip_plug(conn) + rescue + UndefinedFunctionError -> + raise "`#{plug_module}` is not skippable. Append `use Pleroma.Web, :plug` to its code." + end + end + ) + end + + # Executed just before actual controller action, invokes before-action hooks (callbacks) + defp action(conn, params) do + with %{halted: false} = conn <- maybe_drop_authentication_if_oauth_check_ignored(conn), + %{halted: false} = conn <- maybe_perform_public_or_authenticated_check(conn), + %{halted: false} = conn <- maybe_perform_authenticated_check(conn), + %{halted: false} = conn <- maybe_halt_on_missing_oauth_scopes_check(conn) do + super(conn, params) + end + end + + # For non-authenticated API actions, drops auth info if OAuth scopes check was ignored + # (neither performed nor explicitly skipped) + defp maybe_drop_authentication_if_oauth_check_ignored(conn) do + if PlugHelper.plug_called?(conn, ExpectPublicOrAuthenticatedCheckPlug) and + not PlugHelper.plug_called_or_skipped?(conn, OAuthScopesPlug) do + OAuthScopesPlug.drop_auth_info(conn) + else + conn + end + end + + # Ensures instance is public -or- user is authenticated if such check was scheduled + defp maybe_perform_public_or_authenticated_check(conn) do + if PlugHelper.plug_called?(conn, ExpectPublicOrAuthenticatedCheckPlug) do + EnsurePublicOrAuthenticatedPlug.call(conn, %{}) + else + conn + end + end + + # Ensures user is authenticated if such check was scheduled + # Note: runs prior to action even if it was already executed earlier in plug chain + # (since OAuthScopesPlug has option of proceeding unauthenticated) + defp maybe_perform_authenticated_check(conn) do + if PlugHelper.plug_called?(conn, ExpectAuthenticatedCheckPlug) do + EnsureAuthenticatedPlug.call(conn, %{}) + else + conn + end + end + + # Halts if authenticated API action neither performs nor explicitly skips OAuth scopes check + defp maybe_halt_on_missing_oauth_scopes_check(conn) do + if PlugHelper.plug_called?(conn, ExpectAuthenticatedCheckPlug) and + not PlugHelper.plug_called_or_skipped?(conn, OAuthScopesPlug) do + conn + |> render_error( + :forbidden, + "Security violation: OAuth scopes check was neither handled nor explicitly skipped." + ) + |> halt() + else + conn + end + end + end + end + + def view do + quote do + use Phoenix.View, + root: "lib/pleroma/web/templates", + namespace: Pleroma.Web + + # Import convenience functions from controllers + import Phoenix.Controller, only: [get_csrf_token: 0, get_flash: 2, view_module: 1] + + import Pleroma.Web.ErrorHelpers + import Pleroma.Web.Gettext + import Pleroma.Web.Router.Helpers + + require Logger + + @doc "Same as `render/3` but wrapped in a rescue block" + def safe_render(view, template, assigns \\ %{}) do + Phoenix.View.render(view, template, assigns) + rescue + error -> + Logger.error( + "#{__MODULE__} failed to render #{inspect({view, template})}\n" <> + Exception.format(:error, error, __STACKTRACE__) + ) + + nil + end + + @doc """ + Same as `render_many/4` but wrapped in rescue block. + """ + def safe_render_many(collection, view, template, assigns \\ %{}) do + Enum.map(collection, fn resource -> + as = Map.get(assigns, :as) || view.__resource__ + assigns = Map.put(assigns, as, resource) + safe_render(view, template, assigns) + end) + |> Enum.filter(& &1) + end + end + end + + def router do + quote do + use Phoenix.Router + # credo:disable-for-next-line Credo.Check.Consistency.MultiAliasImportRequireUse + import Plug.Conn + import Phoenix.Controller + end + end + + def channel do + quote do + # credo:disable-for-next-line Credo.Check.Consistency.MultiAliasImportRequireUse + use Phoenix.Channel + import Pleroma.Web.Gettext + end + end + + def plug do + quote do + @behaviour Pleroma.Web.Plug + @behaviour Plug + + @doc """ + Marks a plug intentionally skipped and blocks its execution if it's present in plugs chain. + """ + def skip_plug(conn) do + PlugHelper.append_to_private_list( + conn, + PlugHelper.skipped_plugs_list_id(), + __MODULE__ + ) + end + + @impl Plug + @doc """ + Before-plug hook that + * ensures the plug is not skipped + * processes `:if_func` / `:unless_func` functional pre-run conditions + * adds plug to the list of called plugs and calls `perform/2` if checks are passed + + Note: multiple invocations of the same plug (with different or same options) are allowed. + """ + def call(%Plug.Conn{} = conn, options) do + if PlugHelper.plug_skipped?(conn, __MODULE__) || + (options[:if_func] && !options[:if_func].(conn)) || + (options[:unless_func] && options[:unless_func].(conn)) do + conn + else + conn = + PlugHelper.append_to_private_list( + conn, + PlugHelper.called_plugs_list_id(), + __MODULE__ + ) + + apply(__MODULE__, :perform, [conn, options]) + end + end + end + end + + @doc """ + When used, dispatch to the appropriate controller/view/etc. + """ + defmacro __using__(which) when is_atom(which) do + apply(__MODULE__, which, []) + end + + def base_url do + Pleroma.Web.Endpoint.url() + end +end |