prosody
148075532021
util/id.lua
Software / code / prosody
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util/id.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 | 8016:9546c629289b |
| child | 12110:b5b799a2a10c |
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-- Prosody IM -- Copyright (C) 2008-2017 Matthew Wild -- Copyright (C) 2008-2017 Waqas Hussain -- Copyright (C) 2008-2017 Kim Alvefur -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local s_gsub = string.gsub; local random_bytes = require "util.random".bytes; local base64_encode = require "util.encodings".base64.encode; local b64url = { ["+"] = "-", ["/"] = "_", ["="] = "" }; local function b64url_random(len) return (s_gsub(base64_encode(random_bytes(len)), "[+/=]", b64url)); end return { short = function () return b64url_random(6); end; medium = function () return b64url_random(12); end; long = function () return b64url_random(24); end; custom = function (size) return function () return b64url_random(size); end; end; }
