Software /
code /
prosody
File
core/s2smanager.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 | 11418:f4b76e500768 |
child | 11900:60676b607b6d |
line wrap: on
line source
-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local hosts = prosody.hosts; local pairs, setmetatable = pairs, setmetatable; local logger_init = require "util.logger".init; local sessionlib = require "util.session"; local log = logger_init("s2smanager"); local prosody = _G.prosody; local incoming_s2s = {}; _G.incoming_s2s = incoming_s2s; prosody.incoming_s2s = incoming_s2s; local fire_event = prosody.events.fire_event; local _ENV = nil; -- luacheck: std none local function new_incoming(conn) local host_session = sessionlib.new("s2sin"); sessionlib.set_id(host_session); sessionlib.set_logger(host_session); sessionlib.set_conn(host_session, conn); host_session.direction = "incoming"; host_session.incoming = true; host_session.hosts = {}; incoming_s2s[host_session] = true; return host_session; end local function new_outgoing(from_host, to_host) local host_session = sessionlib.new("s2sout"); sessionlib.set_id(host_session); sessionlib.set_logger(host_session); host_session.to_host = to_host; host_session.from_host = from_host; host_session.host = from_host; host_session.notopen = true; host_session.direction = "outgoing"; host_session.outgoing = true; host_session.hosts = {}; hosts[from_host].s2sout[to_host] = host_session; return host_session; end local resting_session = { -- Resting, not dead destroyed = true; type = "s2s_destroyed"; direction = "destroyed"; open_stream = function (session) session.log("debug", "Attempt to open stream on resting session"); end; close = function (session) session.log("debug", "Attempt to close already-closed session"); end; reset_stream = function (session) session.log("debug", "Attempt to reset stream of already-closed session"); end; filter = function (type, data) return data; end; --luacheck: ignore 212/type }; resting_session.__index = resting_session; local function retire_session(session, reason) local log = session.log or log; --luacheck: ignore 431/log for k in pairs(session) do if k ~= "log" and k ~= "id" and k ~= "conn" then session[k] = nil; end end session.destruction_reason = reason; function session.send(data) log("debug", "Discarding data sent to resting session: %s", data); end function session.data(data) log("debug", "Discarding data received from resting session: %s", data); end session.thread = { run = function (_, data) return session.data(data) end }; session.sends2s = session.send; return setmetatable(session, resting_session); end local function destroy_session(session, reason, bounce_reason) if session.destroyed then return; end local log = session.log or log; log("debug", "Destroying %s session %s->%s%s%s", session.direction, session.from_host, session.to_host, reason and ": " or "", reason or ""); if session.direction == "outgoing" then hosts[session.from_host].s2sout[session.to_host] = nil; session:bounce_sendq(bounce_reason or reason); elseif session.direction == "incoming" then if session.outgoing then hosts[session.to_host].s2sout[session.from_host] = nil; end incoming_s2s[session] = nil; end local event_data = { session = session, reason = reason }; if session.type == "s2sout" then fire_event("s2sout-destroyed", event_data); if hosts[session.from_host] then hosts[session.from_host].events.fire_event("s2sout-destroyed", event_data); end elseif session.type == "s2sin" then fire_event("s2sin-destroyed", event_data); if hosts[session.to_host] then hosts[session.to_host].events.fire_event("s2sin-destroyed", event_data); end end retire_session(session, reason); -- Clean session until it is GC'd return true; end return { incoming_s2s = incoming_s2s; new_incoming = new_incoming; new_outgoing = new_outgoing; retire_session = retire_session; destroy_session = destroy_session; };