File

util/stanza.lua @ 11545:7b8a482f4efd 0.11

MUC: Add support for advertising muc#roomconfig_allowinvites in room disco#info The de-facto interpretation of this (undocumented) option is to indicate to the client whether it is allowed to invite other users to the MUC. This is differs from the existing option in our config form, which only controls the behaviour of sending of invites in a members-only MUC (we always allow invites in open rooms). Conversations is one client known to use this disco#info item to determine whether it may send invites.
author Matthew Wild <mwild1@gmail.com>
date Mon, 10 May 2021 17:01:38 +0100
parent 11261:be38ae8fdfa5
child 11264:2cdcf55c6dd5
child 12797:be09ac8300a7
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 error         =         error;
local t_insert      =  table.insert;
local t_remove      =  table.remove;
local t_concat      =  table.concat;
local s_format      = string.format;
local s_match       =  string.match;
local tostring      =      tostring;
local setmetatable  =  setmetatable;
local getmetatable  =  getmetatable;
local pairs         =         pairs;
local ipairs        =        ipairs;
local type          =          type;
local s_gsub        =   string.gsub;
local s_sub         =    string.sub;
local s_find        =   string.find;
local os            =            os;

local valid_utf8 = require "util.encodings".utf8.valid;

local do_pretty_printing = not os.getenv("WINDIR");
local getstyle, getstring;
if do_pretty_printing then
	local ok, termcolours = pcall(require, "util.termcolours");
	if ok then
		getstyle, getstring = termcolours.getstyle, termcolours.getstring;
	else
		do_pretty_printing = nil;
	end
end

local xmlns_stanzas = "urn:ietf:params:xml:ns:xmpp-stanzas";

local _ENV = nil;
-- luacheck: std none

local stanza_mt = { __name = "stanza" };
stanza_mt.__index = stanza_mt;

local function valid_xml_cdata(str, attr)
	return not s_find(str, attr and "[^\1\9\10\13\20-~\128-\247]" or "[^\9\10\13\20-~\128-\247]");
end

local function check_name(name, name_type)
	if type(name) ~= "string" then
		error("invalid "..name_type.." name: expected string, got "..type(name));
	elseif #name == 0 then
		error("invalid "..name_type.." name: empty string");
	elseif s_find(name, "[<>& '\"]") then
		error("invalid "..name_type.." name: contains invalid characters");
	elseif not valid_xml_cdata(name, name_type == "attribute") then
		error("invalid "..name_type.." name: contains control characters");
	elseif not valid_utf8(name) then
		error("invalid "..name_type.." name: contains invalid utf8");
	end
end

local function check_text(text, text_type)
	if type(text) ~= "string" then
		error("invalid "..text_type.." value: expected string, got "..type(text));
	elseif not valid_xml_cdata(text, false) then
		error("invalid "..text_type.." value: contains control characters");
	elseif not valid_utf8(text) then
		error("invalid "..text_type.." value: contains invalid utf8");
	end
end

local function check_attr(attr)
	if attr ~= nil then
		if type(attr) ~= "table" then
			error("invalid attributes, expected table got "..type(attr));
		end
		for k, v in pairs(attr) do
			check_name(k, "attribute");
			check_text(v, "attribute");
			if type(v) ~= "string" then
				error("invalid attribute value for '"..k.."': expected string, got "..type(v));
			elseif not valid_utf8(v) then
				error("invalid attribute value for '"..k.."': contains invalid utf8");
			end
		end
	end
end

local function new_stanza(name, attr, namespaces)
	check_name(name, "tag");
	check_attr(attr);
	local stanza = { name = name, attr = attr or {}, namespaces = namespaces, tags = {} };
	return setmetatable(stanza, stanza_mt);
end

local function is_stanza(s)
	return getmetatable(s) == stanza_mt;
end

function stanza_mt:query(xmlns)
	return self:tag("query", { xmlns = xmlns });
end

function stanza_mt:body(text, attr)
	return self:tag("body", attr):text(text);
end

function stanza_mt:text_tag(name, text, attr, namespaces)
	return self:tag(name, attr, namespaces):text(text):up();
end

function stanza_mt:tag(name, attr, namespaces)
	local s = new_stanza(name, attr, namespaces);
	local last_add = self.last_add;
	if not last_add then last_add = {}; self.last_add = last_add; end
	(last_add[#last_add] or self):add_direct_child(s);
	t_insert(last_add, s);
	return self;
end

function stanza_mt:text(text)
	if text ~= nil and text ~= "" then
		local last_add = self.last_add;
		(last_add and last_add[#last_add] or self):add_direct_child(text);
	end
	return self;
end

function stanza_mt:up()
	local last_add = self.last_add;
	if last_add then t_remove(last_add); end
	return self;
end

function stanza_mt:reset()
	self.last_add = nil;
	return self;
end

function stanza_mt:add_direct_child(child)
	if is_stanza(child) then
		t_insert(self.tags, child);
		t_insert(self, child);
	else
		check_text(child, "text");
		t_insert(self, child);
	end
end

function stanza_mt:add_child(child)
	local last_add = self.last_add;
	(last_add and last_add[#last_add] or self):add_direct_child(child);
	return self;
end

function stanza_mt:remove_children(name, xmlns)
	xmlns = xmlns or self.attr.xmlns;
	return self:maptags(function (tag)
		if (not name or tag.name == name) and tag.attr.xmlns == xmlns then
			return nil;
		end
		return tag;
	end);
end

function stanza_mt:get_child(name, xmlns)
	for _, child in ipairs(self.tags) do
		if (not name or child.name == name)
			and ((not xmlns and self.attr.xmlns == child.attr.xmlns)
				or child.attr.xmlns == xmlns) then

			return child;
		end
	end
end

function stanza_mt:get_child_text(name, xmlns)
	local tag = self:get_child(name, xmlns);
	if tag then
		return tag:get_text();
	end
	return nil;
end

function stanza_mt:child_with_name(name)
	for _, child in ipairs(self.tags) do
		if child.name == name then return child; end
	end
end

function stanza_mt:child_with_ns(ns)
	for _, child in ipairs(self.tags) do
		if child.attr.xmlns == ns then return child; end
	end
end

function stanza_mt:children()
	local i = 0;
	return function (a)
			i = i + 1
			return a[i];
		end, self, i;
end

function stanza_mt:childtags(name, xmlns)
	local tags = self.tags;
	local start_i, max_i = 1, #tags;
	return function ()
		for i = start_i, max_i do
			local v = tags[i];
			if (not name or v.name == name)
			and ((not xmlns and self.attr.xmlns == v.attr.xmlns)
				or v.attr.xmlns == xmlns) then
				start_i = i+1;
				return v;
			end
		end
	end;
end

function stanza_mt:maptags(callback)
	local tags, curr_tag = self.tags, 1;
	local n_children, n_tags = #self, #tags;
	local max_iterations = n_children + 1;

	local i = 1;
	while curr_tag <= n_tags and n_tags > 0 do
		if self[i] == tags[curr_tag] then
			local ret = callback(self[i]);
			if ret == nil then
				t_remove(self, i);
				t_remove(tags, curr_tag);
				n_children = n_children - 1;
				n_tags = n_tags - 1;
				i = i - 1;
				curr_tag = curr_tag - 1;
			else
				self[i] = ret;
				tags[curr_tag] = ret;
			end
			curr_tag = curr_tag + 1;
		end
		i = i + 1;
		if i > max_iterations then
			-- COMPAT: Hopefully temporary guard against #981 while we
			-- figure out the root cause
			error("Invalid stanza state! Please report this error.");
		end
	end
	return self;
end

function stanza_mt:find(path)
	local pos = 1;
	local len = #path + 1;

	repeat
		local xmlns, name, text;
		local char = s_sub(path, pos, pos);
		if char == "@" then
			return self.attr[s_sub(path, pos + 1)];
		elseif char == "{" then
			xmlns, pos = s_match(path, "^([^}]+)}()", pos + 1);
		end
		name, text, pos = s_match(path, "^([^@/#]*)([/#]?)()", pos);
		name = name ~= "" and name or nil;
		if pos == len then
			if text == "#" then
				return self:get_child_text(name, xmlns);
			end
			return self:get_child(name, xmlns);
		end
		self = self:get_child(name, xmlns);
	until not self
end


local escape_table = { ["'"] = "&apos;", ["\""] = "&quot;", ["<"] = "&lt;", [">"] = "&gt;", ["&"] = "&amp;" };
local function xml_escape(str) return (s_gsub(str, "['&<>\"]", escape_table)); end

local function _dostring(t, buf, self, _xml_escape, parentns)
	local nsid = 0;
	local name = t.name
	t_insert(buf, "<"..name);
	for k, v in pairs(t.attr) do
		if s_find(k, "\1", 1, true) then
			local ns, attrk = s_match(k, "^([^\1]*)\1?(.*)$");
			nsid = nsid + 1;
			t_insert(buf, " xmlns:ns"..nsid.."='".._xml_escape(ns).."' ".."ns"..nsid..":"..attrk.."='".._xml_escape(v).."'");
		elseif not(k == "xmlns" and v == parentns) then
			t_insert(buf, " "..k.."='".._xml_escape(v).."'");
		end
	end
	local len = #t;
	if len == 0 then
		t_insert(buf, "/>");
	else
		t_insert(buf, ">");
		for n=1,len do
			local child = t[n];
			if child.name then
				self(child, buf, self, _xml_escape, t.attr.xmlns);
			else
				t_insert(buf, _xml_escape(child));
			end
		end
		t_insert(buf, "</"..name..">");
	end
end
function stanza_mt.__tostring(t)
	local buf = {};
	_dostring(t, buf, _dostring, xml_escape, nil);
	return t_concat(buf);
end

function stanza_mt.top_tag(t)
	local attr_string = "";
	if t.attr then
		for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(" %s='%s'", k, xml_escape(tostring(v))); end end
	end
	return s_format("<%s%s>", t.name, attr_string);
end

function stanza_mt.get_text(t)
	if #t.tags == 0 then
		return t_concat(t);
	end
end

function stanza_mt.get_error(stanza)
	local error_type, condition, text;

	local error_tag = stanza:get_child("error");
	if not error_tag then
		return nil, nil, nil;
	end
	error_type = error_tag.attr.type;

	for _, child in ipairs(error_tag.tags) do
		if child.attr.xmlns == xmlns_stanzas then
			if not text and child.name == "text" then
				text = child:get_text();
			elseif not condition then
				condition = child.name;
			end
			if condition and text then
				break;
			end
		end
	end
	return error_type, condition or "undefined-condition", text;
end

local function preserialize(stanza)
	local s = { name = stanza.name, attr = stanza.attr };
	for _, child in ipairs(stanza) do
		if type(child) == "table" then
			t_insert(s, preserialize(child));
		else
			t_insert(s, child);
		end
	end
	return s;
end

stanza_mt.__freeze = preserialize;

local function deserialize(serialized)
	-- Set metatable
	if serialized then
		local attr = serialized.attr;
		local attrx = {};
		for att, val in pairs(attr) do
			if type(att) == "string" then
				if s_find(att, "|", 1, true) and not s_find(att, "\1", 1, true) then
					local ns,na = s_match(att, "^([^|]+)|(.+)$");
					attrx[ns.."\1"..na] = val;
				else
					attrx[att] = val;
				end
			end
		end
		local stanza = new_stanza(serialized.name, attrx);
		for _, child in ipairs(serialized) do
			if type(child) == "table" then
				stanza:add_direct_child(deserialize(child));
			elseif type(child) == "string" then
				stanza:add_direct_child(child);
			end
		end
		return stanza;
	end
end

local function _clone(stanza)
	local attr, tags = {}, {};
	for k,v in pairs(stanza.attr) do attr[k] = v; end
	local old_namespaces, namespaces = stanza.namespaces;
	if old_namespaces then
		namespaces = {};
		for k,v in pairs(old_namespaces) do namespaces[k] = v; end
	end
	local new = { name = stanza.name, attr = attr, namespaces = namespaces, tags = tags };
	for i=1,#stanza do
		local child = stanza[i];
		if child.name then
			child = _clone(child);
			t_insert(tags, child);
		end
		t_insert(new, child);
	end
	return setmetatable(new, stanza_mt);
end

local function clone(stanza)
	if not is_stanza(stanza) then
		error("bad argument to clone: expected stanza, got "..type(stanza));
	end
	return _clone(stanza);
end

local function message(attr, body)
	if not body then
		return new_stanza("message", attr);
	else
		return new_stanza("message", attr):tag("body"):text(body):up();
	end
end
local function iq(attr)
	if not (attr and attr.id) then
		error("iq stanzas require an id attribute");
	end
	return new_stanza("iq", attr);
end

local function reply(orig)
	return new_stanza(orig.name,
		orig.attr and {
			to = orig.attr.from,
			from = orig.attr.to,
			id = orig.attr.id,
			type = ((orig.name == "iq" and "result") or orig.attr.type)
		});
end

local xmpp_stanzas_attr = { xmlns = xmlns_stanzas };
local function error_reply(orig, error_type, condition, error_message)
	local t = reply(orig);
	t.attr.type = "error";
	t:tag("error", {type = error_type}) --COMPAT: Some day xmlns:stanzas goes here
	:tag(condition, xmpp_stanzas_attr):up();
	if error_message then t:tag("text", xmpp_stanzas_attr):text(error_message):up(); end
	return t; -- stanza ready for adding app-specific errors
end

local function presence(attr)
	return new_stanza("presence", attr);
end

if do_pretty_printing then
	local style_attrk = getstyle("yellow");
	local style_attrv = getstyle("red");
	local style_tagname = getstyle("red");
	local style_punc = getstyle("magenta");

	local attr_format = " "..getstring(style_attrk, "%s")..getstring(style_punc, "=")..getstring(style_attrv, "'%s'");
	local top_tag_format = getstring(style_punc, "<")..getstring(style_tagname, "%s").."%s"..getstring(style_punc, ">");
	--local tag_format = getstring(style_punc, "<")..getstring(style_tagname, "%s").."%s"..getstring(style_punc, ">").."%s"..getstring(style_punc, "</")..getstring(style_tagname, "%s")..getstring(style_punc, ">");
	local tag_format = top_tag_format.."%s"..getstring(style_punc, "</")..getstring(style_tagname, "%s")..getstring(style_punc, ">");
	function stanza_mt.pretty_print(t)
		local children_text = "";
		for _, child in ipairs(t) do
			if type(child) == "string" then
				children_text = children_text .. xml_escape(child);
			else
				children_text = children_text .. child:pretty_print();
			end
		end

		local attr_string = "";
		if t.attr then
			for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(attr_format, k, tostring(v)); end end
		end
		return s_format(tag_format, t.name, attr_string, children_text, t.name);
	end

	function stanza_mt.pretty_top_tag(t)
		local attr_string = "";
		if t.attr then
			for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(attr_format, k, tostring(v)); end end
		end
		return s_format(top_tag_format, t.name, attr_string);
	end
else
	-- Sorry, fresh out of colours for you guys ;)
	stanza_mt.pretty_print = stanza_mt.__tostring;
	stanza_mt.pretty_top_tag = stanza_mt.top_tag;
end

return {
	stanza_mt = stanza_mt;
	stanza = new_stanza;
	is_stanza = is_stanza;
	preserialize = preserialize;
	deserialize = deserialize;
	clone = clone;
	message = message;
	iq = iq;
	reply = reply;
	error_reply = error_reply;
	presence = presence;
	xml_escape = xml_escape;
};