view mod_muc_moderation/mod_muc_moderation.lua @ 5354:39d59d857bfb

mod_http_oauth2: Use new mod_cron API for periodic cleanup Less frequent but this isn't that important after all since, as the comment states, expired codes are not usable anyway. They're also not that large so memory usage probably doesn't matter.
author Kim Alvefur <zash@zash.se>
date Sat, 22 Apr 2023 11:59:52 +0200
parents 4d6af8950016
children 06fad22672e1
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-- mod_muc_moderation
--
-- Copyright (C) 2015-2021 Kim Alvefur
--
-- This file is MIT licensed.
--
-- Implements: XEP-0425: Message Moderation
--
-- Imports
local dt = require "util.datetime";
local id = require "util.id";
local jid = require "util.jid";
local st = require "util.stanza";

-- Plugin dependencies
local mod_muc = module:depends "muc";

local muc_util = module:require "muc/util";
local valid_roles = muc_util.valid_roles;

local muc_log_archive = module:open_store("muc_log", "archive");

if not muc_log_archive.set then
	module:log("warn", "Selected archive storage module does not support message replacement, no tombstones will be saved");
end

-- Namespaces
local xmlns_fasten = "urn:xmpp:fasten:0";
local xmlns_moderate = "urn:xmpp:message-moderate:0";
local xmlns_retract = "urn:xmpp:message-retract:0";

-- Discovering support
module:hook("muc-disco#info", function (event)
	event.reply:tag("feature", { var = xmlns_moderate }):up();
end);

-- TODO error registry, requires Prosody 0.12+

-- moderate : function (string, string, string, boolean, string) : boolean, enum, enum, string
local function moderate(actor, room_jid, stanza_id, retract, reason)
	local room_node = jid.split(room_jid);
	local room = mod_muc.get_room_from_jid(room_jid);

	-- Permissions is based on role, which is a property of a current occupant,
	-- so check if the actor is an occupant, otherwise if they have a reserved
	-- nickname that can be used to retrieve the role.
	local actor_nick = room:get_occupant_jid(actor);
	if not actor_nick then
		local reserved_nickname = room:get_affiliation_data(jid.bare(actor), "reserved_nickname");
		if reserved_nickname then
			actor_nick = room.jid .. "/" .. reserved_nickname;
		end
	end

	-- Retrieve their current role, iff they are in the room, otherwise what they
	-- would have based on affiliation.
	local affiliation = room:get_affiliation(actor);
	local role = room:get_role(actor_nick) or room:get_default_role(affiliation);
	if valid_roles[role or "none"] < valid_roles.moderator then
		return false, "auth", "forbidden", "You need a role of at least 'moderator'";
	end

	-- Original stanza to base tombstone on
	local original, err;
	if muc_log_archive.get then
		original, err = muc_log_archive:get(room_node, stanza_id);
	else
		-- COMPAT missing :get API
		err = "item-not-found";
		for i, item in muc_log_archive:find(room_node, { key = stanza_id, limit = 1 }) do
			if i == stanza_id then
				original, err = item, nil;
			end
		end
	end

	if not original then
		if err == "item-not-found" then
			return false, "modify", "item-not-found";
		else
			return false, "wait", "internal-server-error";
		end
	end


	local announcement = st.message({ from = room_jid, type = "groupchat", id = id.medium(), })
		:tag("apply-to", { xmlns = xmlns_fasten, id = stanza_id })
			:tag("moderated", { xmlns = xmlns_moderate, by = actor_nick })

	if retract then
		announcement:tag("retract", { xmlns = xmlns_retract }):up();
	end

	if reason then
		announcement:text_tag("reason", reason);
	end

	if muc_log_archive.set and retract then
		local tombstone = st.message({ from = original.attr.from, type = "groupchat", id = original.attr.id })
			:tag("moderated", { xmlns = xmlns_moderate, by = actor_nick })
				:tag("retracted", { xmlns = xmlns_retract, stamp = dt.datetime() }):up();

		if reason then
			tombstone:text_tag("reason", reason);
		end
		tombstone:reset();

		local was_replaced = muc_log_archive:set(room_node, stanza_id, tombstone);
		if not was_replaced then
			return false, "wait", "internal-server-error";
		end
	end

	-- Done, tell people about it
	module:log("info", "Message with id '%s' in room %s moderated by %s, reason: %s", stanza_id, room_jid, actor, reason);
	room:broadcast_message(announcement);

	return true;
end

-- Main handling
module:hook("iq-set/bare/" .. xmlns_fasten .. ":apply-to", function (event)
	local stanza, origin = event.stanza, event.origin;

	local actor = stanza.attr.from;
	local room_jid = stanza.attr.to;

	-- Collect info we need
	local apply_to = stanza.tags[1];
	local moderate_tag = apply_to:get_child("moderate", xmlns_moderate);
	if not moderate_tag then return end -- some other kind of fastening?

	local reason = moderate_tag:get_child_text("reason");
	local retract = moderate_tag:get_child("retract", xmlns_retract);

	local stanza_id = apply_to.attr.id;

	local ok, error_type, error_condition, error_text = moderate(actor, room_jid, stanza_id, retract, reason);
	if not ok then
		origin.send(st.error_reply(stanza, error_type, error_condition, error_text));
		return true;
	end

	origin.send(st.reply(stanza));
	return true;
end);

module:hook("muc-message-is-historic", function (event)
	-- Ensure moderation messages are stored
	if event.stanza.attr.from == event.room.jid then
		return event.stanza:get_child("apply-to", xmlns_fasten);
	end
end, 1);