File

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>
date Sun, 11 Jul 2021 09:39:21 +0200
parent 11056:0b0a42542456
child 12190:3616128cd2e3
line wrap: on
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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;
};