File

+
−
+
−local mod_muc = module:depends"muc";
+
−local rooms = rawget(mod_muc, "rooms"); -- Old MUC API
+
−
+
−local jid_split, jid_bare = require "util.jid".split, require "util.jid".bare;
+
−local st = require "util.stanza";
+
−local new_throttle = require "util.throttle".create;
+
−local t_insert, t_concat = table.insert, table.concat;
+
−
+
−local xmlns_muc = "http://jabber.org/protocol/muc";
+
−
+
−local period = math.max(module:get_option_number("muc_event_rate", 0.5), 0);
+
−local burst = math.max(module:get_option_number("muc_burst_factor", 6), 1);
+
−
+
−local max_nick_length = module:get_option_number("muc_max_nick_length", 23); -- Default chosen through scientific methods
+
−local max_line_count = module:get_option_number("muc_max_line_count", 23); -- Default chosen through s/scientific methods/copy and paste/
+
−local max_char_count = module:get_option_number("muc_max_char_count", 5664); -- Default chosen by multiplying a number by 23
+
−local base_cost = math.max(module:get_option_number("muc_limit_base_cost", 1), 0);
+
−local line_multiplier = math.max(module:get_option_number("muc_line_count_multiplier", 0.1), 0);
+
−
+
−local join_only = module:get_option_boolean("muc_limit_joins_only", false);
+
−local dropped_count = 0;
+
−local dropped_jids;
+
−
+
−local function log_dropped()
+
−	module:log("warn", "Dropped %d stanzas from %d JIDs: %s", dropped_count, #dropped_jids, t_concat(dropped_jids, ", "));
+
−	dropped_count = 0;
+
−	dropped_jids = nil;
+
−end
+
−
+
−local function handle_stanza(event)
+
−	local origin, stanza = event.origin, event.stanza;
+
−	if stanza.name == "presence" and stanza.attr.type == "unavailable" then -- Don't limit room leaving
+
−		return;
+
−	end
+
−	local dest_room, dest_host, dest_nick = jid_split(stanza.attr.to);
+
−	local room = event.room or rooms[dest_room.."@"..dest_host];
+
−	if not room then return; end
+
−	local from_jid = stanza.attr.from;
+
−	if room:get_affiliation(jid_bare(from_jid)) then
+
−		module:log("debug", "Skipping stanza from affiliated user...");
+
−		return;
+
−	elseif dest_nick and max_nick_length and stanza.name == "presence" and not room._occupants[stanza.attr.to] and #dest_nick > max_nick_length then
+
−		module:log("debug", "Forbidding long (%d bytes) nick in %s", #dest_nick, dest_room)
+
−		origin.send(st.error_reply(stanza, "modify", "policy-violation", "Your nick name is too long, please use a shorter one")
+
−			:up():tag("x", { xmlns = xmlns_muc }));
+
−		return true;
+
−	end
+
−	local throttle = room.throttle;
+
−	if not room.throttle then
+
−		throttle = new_throttle(period*burst, burst);
+
−		room.throttle = throttle;
+
−	end
+
−	local cost = base_cost;
+
−	local body = stanza:get_child_text("body");
+
−	if body then
+
−		-- TODO calculate a text diagonal cross-section or some mathemagical
+
−		-- number, maybe some cost multipliers
+
−		if #body > max_char_count then
+
−			origin.send(st.error_reply(stanza, "modify", "policy-violation", "Your message is too long, please write a shorter one")
+
−				:up():tag("x", { xmlns = xmlns_muc }));
+
−			return true;
+
−		end
+
−		local body_lines = select(2, body:gsub("\n[^\n]*", ""));
+
−		if body_lines > max_line_count then
+
−			origin.send(st.error_reply(stanza, "modify", "policy-violation", "Your message is too long, please write a shorter one"):up()
+
−				:tag("x", { xmlns = xmlns_muc; }));
+
−			return true;
+
−		end
+
−		cost = cost + (body_lines * line_multiplier);
+
−	end
+
−	if not throttle:poll(cost) then
+
−		module:log("debug", "Dropping stanza for %s@%s from %s, over rate limit", dest_room, dest_host, from_jid);
+
−		if not dropped_jids then
+
−			dropped_jids = { [from_jid] = true, from_jid };
+
−			module:add_timer(5, log_dropped);
+
−		elseif not dropped_jids[from_jid] then
+
−			dropped_jids[from_jid] = true;
+
−			t_insert(dropped_jids, from_jid);
+
−		end
+
−		dropped_count = dropped_count + 1;
+
−		if stanza.attr.type == "error" then -- We don't want to bounce errors
+
−			return true;
+
−		end
+
−		local reply = st.error_reply(stanza, "wait", "policy-violation", "The room is currently overactive, please try again later");
+
−		if body then
+
−			reply:up():tag("body"):text(body):up();
+
−		end
+
−		local x = stanza:get_child("x", xmlns_muc);
+
−		if x then
+
−			reply:add_child(st.clone(x));
+
−		end
+
−		origin.send(reply);
+
−		return true;
+
−	end
+
−end
+
−
+
−if rooms then
+
−	function module.unload()
+
−		for room_jid, room in pairs(rooms) do --luacheck: ignore 213/room_jid
+
−			room.throttle = nil;
+
−		end
+
−	end
+
−
+
−	module:hook("presence/full", handle_stanza, 501);
+
−	if not join_only then
+
−		module:hook("message/bare", handle_stanza, 501);
+
−		module:hook("message/full", handle_stanza, 501);
+
−		module:hook("presence/bare", handle_stanza, 501);
+
−	end
+
−else
+
−	module:hook("muc-occupant-pre-join", handle_stanza);
+
−	if not join_only then
+
−		module:hook("muc-occupant-pre-change", handle_stanza);
+
−		module:hook("muc-occupant-groupchat", handle_stanza);
+
−	end
+
−end