Software /
code /
prosody
File
plugins/muc/lock.lib.lua @ 11665:148075532021
net.server_epoll: Prevent stack overflow of opportunistic writes
net.http.files serving a big enough file on a fast enough connection
with opportunistic_writes enabled could trigger a stack overflow through
repeatedly serving more data that immediately gets sent, draining the
buffer and triggering more data to be sent. This also blocked the server
on a single task until completion or an error.
This change prevents nested opportunistic writes, which should prevent
the stack overflow, at the cost of reduced download speed, but this is
unlikely to be noticeable outside of Gbit networks. Speed at the cost of
blocking other processing is not worth it, especially with the risk of
stack overflow.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 11 Jul 2021 09:39:21 +0200 |
parent | 10450:c1edeb9fe337 |
child | 12977:74b9e05af71e |
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-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- Copyright (C) 2014 Daurnimator -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local st = require "util.stanza"; local lock_rooms = module:get_option_boolean("muc_room_locking", true); local lock_room_timeout = module:get_option_number("muc_room_lock_timeout", 300); local function lock(room) module:fire_event("muc-room-locked", {room = room;}); room._data.locked = os.time() + lock_room_timeout; end local function unlock(room) module:fire_event("muc-room-unlocked", {room = room;}); room._data.locked = nil; end local function is_locked(room) local ts = room._data.locked; if ts then if os.time() < ts then return true; end unlock(room); end return false; end if lock_rooms then module:hook("muc-room-pre-create", function(event) -- Older groupchat protocol doesn't lock if not event.stanza:get_child("x", "http://jabber.org/protocol/muc") then return end -- Lock room at creation local room = event.room; lock(room); end, 10); end -- Don't let users into room while it is locked module:hook("muc-occupant-pre-join", function(event) if not event.is_new_room and is_locked(event.room) then -- Deny entry module:log("debug", "Room is locked, denying entry"); event.origin.send(st.error_reply(event.stanza, "cancel", "item-not-found", nil, module.host)); return true; end end, -30); -- When config is submitted; unlock the room module:hook("muc-config-submitted", function(event) if is_locked(event.room) then unlock(event.room); end end, -1); return { lock = lock; unlock = unlock; is_locked = is_locked; };