File

util/stanza.lua @ 13107:9c4dc1e6d2c9

mod_http: Add way to retrieve internal URL instead of external This could be of help when configuring reverse proxies, as it is the internal URL the proxy must point at. Argument treated as an enum "internal" "external"(default) to allow for future extensibility.
author Kim Alvefur <zash@zash.se>
date Wed, 24 May 2023 14:43:45 +0200
parent 12975:d10957394a3c
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_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 t_move        =    table.move or require "prosody.util.table".move;
local t_create = require"prosody.util.table".create;

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

local do_pretty_printing, termcolours = pcall(require, "prosody.util.termcolours");

local xmlns_stanzas = "urn:ietf:params:xml:ns:xmpp-stanzas";
local xmpp_stanzas_attr = { xmlns = xmlns_stanzas };

local _ENV = nil;
-- luacheck: std none

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

-- Basic check for valid XML character data.
-- Disallow control characters.
-- Tab U+09 and newline U+0A are allowed.
-- For attributes, allow the \1 separator between namespace and name.
local function valid_xml_cdata(str, attr)
	return not s_find(str, attr and "[^\1\9\10\13\20-\255]" or "[^\9\10\13\20-\255]");
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");
		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:text_tag("body", text, attr);
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:at_top()
	return self.last_add == nil or #self.last_add == 0
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
	return nil;
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:get_child_attr(name, xmlns, attr)
	local tag = self:get_child(name, xmlns);
	if tag then
		return tag.attr[attr];
	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
	return nil;
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
	return nil;
end

function stanza_mt:get_child_with_attr(name, xmlns, attr_name, attr_value, normalize)
	for tag in self:childtags(name, xmlns) do
		if (normalize and normalize(tag.attr[attr_name]) or tag.attr[attr_name]) == attr_value then
			return tag;
		end
	end
	return nil;
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 function _clone(stanza, only_top)
	local attr = {};
	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 tags, new;
	if only_top then
		tags = {};
		new = { name = stanza.name, attr = attr, namespaces = namespaces, tags = tags };
	else
		tags = t_create(#stanza.tags, 0);
		new = t_create(#stanza, 4);
		new.name = stanza.name;
		new.attr = attr;
		new.namespaces = namespaces;
		new.tags = tags;
	end

	setmetatable(new, stanza_mt);
	if not only_top then
		t_move(stanza, 1, #stanza, 1, new);
		t_move(stanza.tags, 1, #stanza.tags, 1, tags);
		new:maptags(_clone);
	end
	return new;
end

local function clone(stanza, only_top)
	if not is_stanza(stanza) then
		error("bad argument to clone: expected stanza, got "..type(stanza));
	end
	return _clone(stanza, only_top);
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 top_tag_clone = clone(t, true);
	return tostring(top_tag_clone):sub(1,-3)..">";
end

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

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

	local error_tag = stanza:get_child("error");
	if not error_tag then
		return nil, 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
		else
			extra_tag = child;
		end
		if condition and text and extra_tag then
			break;
		end
	end
	return error_type, condition or "undefined-condition", text, extra_tag;
end

function stanza_mt.add_error(stanza, error_type, condition, error_message, error_by)
	local extra;
	if type(error_type) == "table" then -- an util.error or similar object
		if type(error_type.extra) == "table" then
			extra = error_type.extra;
		end
		if type(error_type.context) == "table" and type(error_type.context.by) == "string" then error_by = error_type.context.by; end
		error_type, condition, error_message = error_type.type, error_type.condition, error_type.text;
	end
	if stanza.attr.from == error_by then
		error_by = nil;
	end
	stanza:tag("error", {type = error_type, by = error_by}) --COMPAT: Some day xmlns:stanzas goes here
	:tag(condition, xmpp_stanzas_attr);
	if extra and condition == "gone" and type(extra.uri) == "string" then
		stanza:text(extra.uri);
	end
	stanza:up();
	if error_message then stanza:text_tag("text", error_message, xmpp_stanzas_attr); end
	if extra and is_stanza(extra.tag) then
		stanza:add_child(extra.tag);
	elseif extra and extra.namespace and extra.condition then
		stanza:tag(extra.condition, { xmlns = extra.namespace }):up();
	end
	return stanza:up();
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 message(attr, body)
	if not body then
		return new_stanza("message", attr);
	else
		return new_stanza("message", attr):text_tag("body", body);
	end
end
local function iq(attr)
	if not attr then
		error("iq stanzas require id and type attributes");
	end
	if not attr.id then
		error("iq stanzas require an id attribute");
	end
	if not attr.type then
		error("iq stanzas require a type attribute");
	end
	return new_stanza("iq", attr);
end

local function reply(orig)
	if not is_stanza(orig) then
		error("bad argument to reply: expected stanza, got "..type(orig));
	end
	return new_stanza(orig.name,
		{
			to = orig.attr.from,
			from = orig.attr.to,
			id = orig.attr.id,
			type = ((orig.name == "iq" and "result") or orig.attr.type)
		});
end

local function error_reply(orig, error_type, condition, error_message, error_by)
	if not is_stanza(orig) then
		error("bad argument to error_reply: expected stanza, got "..type(orig));
	elseif orig.attr.type == "error" then
		error("bad argument to error_reply: got stanza of type error which must not be replied to");
	end
	local t = reply(orig);
	t.attr.type = "error";
	t:add_error(error_type, condition, error_message, error_by);
	t.last_add = { t[1] }; -- ready to add application-specific errors
	return t;
end

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

local pretty;
if do_pretty_printing then
	local getstyle, getstring = termcolours.getstyle, termcolours.getstring;

	local blue1 = getstyle("1b3967");
	local blue2 = getstyle("13b5ea");
	local green1 = getstyle("439639");
	local green2 = getstyle("a0ce67");
	local orange1 = getstyle("d9541e");
	local orange2 = getstyle("e96d1f");

	local attr_replace = (
		getstring(green2, "%1") .. -- attr name
		getstring(green1, "%2") .. -- equal
		getstring(orange1, "%3") .. -- quote
		getstring(orange2, "%4") .. -- attr value
		getstring(orange1, "%5") -- quote
	);

	local text_replace = (
		getstring(green1, "%1") .. -- &
		getstring(green2, "%2") .. -- amp
		getstring(green1, "%3") -- ;
	);

	function pretty(s)
		-- Tag soup color
		-- Outer gsub call takes each <tag>, applies colour to the brackets, the
		-- tag name, then applies one inner gsub call to colour the attributes and
		-- another for any text content.
		return (s:gsub("(<[?/]?)([^ >/?]*)(.-)([?/]?>)([^<]*)", function(opening_bracket, tag_name, attrs, closing_bracket, content)
			return getstring(blue1, opening_bracket)..getstring(blue2, tag_name)..
				attrs:gsub("([^=]+)(=)([\"'])(.-)([\"'])", attr_replace) ..
			getstring(blue1, closing_bracket) ..
			content:gsub("(&#?)(%w+)(;)", text_replace);
		end, 100));
	end

	function stanza_mt.pretty_print(t)
		return pretty(tostring(t));
	end

	function stanza_mt.pretty_top_tag(t)
		return pretty(t:top_tag());
	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

function stanza_mt.indent(t, level, indent)
	if #t == 0 or (#t == 1 and type(t[1]) == "string") then
		-- Empty nodes wouldn't have any indentation
		-- Text-only nodes are preserved as to not alter the text content
		-- Optimization: Skip clone of these since we don't alter them
		return t;
	end

	indent = indent or "\t";
	level = level or 1;
	local tag = clone(t, true);

	for child in t:children() do
		if type(child) == "string" then
			-- Already indented text would look weird but let's ignore that for now.
			if child:find("%S") then
				tag:text("\n" .. indent:rep(level));
				tag:text(child);
			end
		elseif is_stanza(child) then
			tag:text("\n" .. indent:rep(level));
			tag:add_direct_child(child:indent(level+1, indent));
		end
	end
	-- before the closing tag
	tag:text("\n" .. indent:rep((level-1)));

	return 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;
	pretty_print = pretty;
};