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util/jid.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> |
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date | Sun, 11 Jul 2021 09:39:21 +0200 |
parent | 11056:0b0a42542456 |
child | 12190:3616128cd2e3 |
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-- 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 select = select; local match, sub = string.match, string.sub; local nodeprep = require "util.encodings".stringprep.nodeprep; local nameprep = require "util.encodings".stringprep.nameprep; local resourceprep = require "util.encodings".stringprep.resourceprep; local escapes = { [" "] = "\\20"; ['"'] = "\\22"; ["&"] = "\\26"; ["'"] = "\\27"; ["/"] = "\\2f"; [":"] = "\\3a"; ["<"] = "\\3c"; [">"] = "\\3e"; ["@"] = "\\40"; ["\\"] = "\\5c"; }; local unescapes = {}; local backslash_escapes = {}; for k,v in pairs(escapes) do unescapes[v] = k; backslash_escapes[v] = v:gsub("\\", escapes) end local _ENV = nil; -- luacheck: std none local function split(jid) if not jid then return; end local node, nodepos = match(jid, "^([^@/]+)@()"); local host, hostpos = match(jid, "^([^@/]+)()", nodepos); if node and not host then return nil, nil, nil; end local resource = match(jid, "^/(.+)$", hostpos); if (not host) or ((not resource) and #jid >= hostpos) then return nil, nil, nil; end return node, host, resource; end local function bare(jid) local node, host = split(jid); if node and host then return node.."@"..host; end return host; end local function prepped_split(jid, strict) local node, host, resource = split(jid); if host and host ~= "." then if sub(host, -1, -1) == "." then -- Strip empty root label host = sub(host, 1, -2); end host = nameprep(host, strict); if not host then return; end if node then node = nodeprep(node, strict); if not node then return; end end if resource then resource = resourceprep(resource, strict); if not resource then return; end end return node, host, resource; end end local function join(node, host, resource) if not host then return end if node and resource then return node.."@"..host.."/"..resource; elseif node then return node.."@"..host; elseif resource then return host.."/"..resource; end return host; end local function prep(jid, strict) local node, host, resource = prepped_split(jid, strict); return join(node, host, resource); end local function compare(jid, acl) -- compare jid to single acl rule -- TODO compare to table of rules? local jid_node, jid_host, jid_resource = split(jid); local acl_node, acl_host, acl_resource = split(acl); if ((acl_node ~= nil and acl_node == jid_node) or acl_node == nil) and ((acl_host ~= nil and acl_host == jid_host) or acl_host == nil) and ((acl_resource ~= nil and acl_resource == jid_resource) or acl_resource == nil) then return true end return false end local function node(jid) return (select(1, split(jid))); end local function host(jid) return (select(2, split(jid))); end local function resource(jid) return (select(3, split(jid))); end local function escape(s) return s and (s:gsub("\\%x%x", backslash_escapes):gsub("[\"&'/:<>@ ]", escapes)); end local function unescape(s) return s and (s:gsub("\\%x%x", unescapes)); end return { split = split; bare = bare; prepped_split = prepped_split; join = join; prep = prep; compare = compare; node = node; host = host; resource = resource; escape = escape; unescape = unescape; };