File

mod_muc_moderation/mod_muc_moderation.lua @ 4047:36b6e3e3f9e2

mod_conversejs: Disable automatic BOSH/WS endpoint discovery Converse.js 7.0 will enable this by default, but when using this module the BOSH and WebSocket endpoints are provided in the generated HTML, so automatic discovery is not needed and unlikely to work without an additional module.
author Kim Alvefur <zash@zash.se>
date Thu, 18 Jun 2020 15:24:34 +0200
parent 3902:341850e8866f
child 4177:a38e6a8a781a
line wrap: on
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-- mod_muc_moderation
--
-- Copyright (C) 2015-2020 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);

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

	-- 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 room_jid = stanza.attr.to;
	local room_node = jid.split(room_jid);
	local room = mod_muc.get_room_from_jid(room_jid);

	local stanza_id = apply_to.attr.id;

	-- Permissions
	local actor = stanza.attr.from;
	local actor_nick = room:get_occupant_jid(actor);
	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
		origin.send(st.error_reply(stanza, "auth", "forbidden", "Insufficient privileges"));
		return true;
	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
			origin.send(st.error_reply(stanza, "modify", "item-not-found"));
		else
			origin.send(st.error_reply(stanza, "wait", "internal-server-error"));
		end
		return true;
	end

	-- Replacements
	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();

	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 })
			:tag("retract", { xmlns = xmlns_retract }):up();

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

	if muc_log_archive.set then
		-- Tombstone
		local was_replaced = muc_log_archive:set(room_node, stanza_id, tombstone);
		if not was_replaced then
			origin.send(st.error_reply(stanza, "wait", "internal-server-error"));
			return true;
		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);

	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);