1 files changed, 112 insertions, 49 deletions

diff --git a/util/stanza.lua b/util/stanza.lua
index 07365144..a90d56b3 100644
--- a/util/stanza.lua
+++ b/util/stanza.lua
@@ -7,6 +7,7 @@
 --
 
 
+local error         =         error;
 local t_insert      =  table.insert;
 local t_remove      =  table.remove;
 local t_concat      =  table.concat;
@@ -23,6 +24,8 @@ 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
@@ -37,12 +40,52 @@ end
 local xmlns_stanzas = "urn:ietf:params:xml:ns:xmpp-stanzas";
 
 local _ENV = nil;
+-- luacheck: std none
 
-local stanza_mt = { __type = "stanza" };
+local stanza_mt = { __name = "stanza" };
 stanza_mt.__index = stanza_mt;
 
-local function new_stanza(name, attr)
-	local stanza = { name = name, attr = attr or {}, tags = {} };
+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_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_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
 
@@ -58,8 +101,12 @@ function stanza_mt:body(text, attr)
 	return self:tag("body", attr):text(text);
 end
 
-function stanza_mt:tag(name, attrs)
-	local s = new_stanza(name, attrs);
+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);
@@ -68,8 +115,10 @@ function stanza_mt:tag(name, attrs)
 end
 
 function stanza_mt:text(text)
-	local last_add = self.last_add;
-	(last_add and last_add[#last_add] or self):add_direct_child(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
 
@@ -85,10 +134,13 @@ function stanza_mt:reset()
 end
 
 function stanza_mt:add_direct_child(child)
-	if type(child) == "table" then
+	if is_stanza(child) then
 		t_insert(self.tags, child);
+		t_insert(self, child);
+	else
+		check_text(child, "text");
+		t_insert(self, child);
 	end
-	t_insert(self, child);
 end
 
 function stanza_mt:add_child(child)
@@ -165,6 +217,7 @@ 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
@@ -184,6 +237,11 @@ function stanza_mt:maptags(callback)
 			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
@@ -289,12 +347,6 @@ function stanza_mt.get_error(stanza)
 	return error_type, condition or "undefined-condition", text;
 end
 
-local id = 0;
-local function new_id()
-	id = id + 1;
-	return "lx"..id;
-end
-
 local function preserialize(stanza)
 	local s = { name = stanza.name, attr = stanza.attr };
 	for _, child in ipairs(stanza) do
@@ -307,51 +359,48 @@ local function preserialize(stanza)
 	return s;
 end
 
-local function deserialize(stanza)
+stanza_mt.__freeze = preserialize;
+
+local function deserialize(serialized)
 	-- Set metatable
-	if stanza then
-		local attr = stanza.attr;
-		for i=1,#attr do attr[i] = nil; end
+	if serialized then
+		local attr = serialized.attr;
 		local attrx = {};
-		for att in pairs(attr) do
-			if s_find(att, "|", 1, true) and not s_find(att, "\1", 1, true) then
-				local ns,na = s_match(att, "^([^|]+)|(.+)$");
-				attrx[ns.."\1"..na] = attr[att];
-				attr[att] = nil;
+		for att, val in pairs(attr) do
+			if type(att) == "string" then
+				if s_find(att, "|", 1, true) and not s_find(att, "\1", 1, true) then
+					local ns,na = s_match(att, "^([^|]+)|(.+)$");
+					attrx[ns.."\1"..na] = val;
+				else
+					attrx[att] = val;
+				end
 			end
 		end
-		for a,v in pairs(attrx) do
-			attr[a] = v;
-		end
-		setmetatable(stanza, stanza_mt);
-		for _, child in ipairs(stanza) do
+		local stanza = new_stanza(serialized.name, attrx);
+		for _, child in ipairs(serialized) do
 			if type(child) == "table" then
-				deserialize(child);
-			end
-		end
-		if not stanza.tags then
-			-- Rebuild tags
-			local tags = {};
-			for _, child in ipairs(stanza) do
-				if type(child) == "table" then
-					t_insert(tags, child);
-				end
+				stanza:add_direct_child(deserialize(child));
+			elseif type(child) == "string" then
+				stanza:add_direct_child(child);
 			end
-			stanza.tags = tags;
 		end
+		return stanza;
 	end
-
-	return stanza;
 end
 
-local function clone(stanza)
+local function _clone(stanza)
 	local attr, tags = {}, {};
 	for k,v in pairs(stanza.attr) do attr[k] = v; end
-	local new = { name = stanza.name, attr = attr, tags = tags };
+	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);
+			child = _clone(child);
 			t_insert(tags, child);
 		end
 		t_insert(new, child);
@@ -359,6 +408,13 @@ local function clone(stanza)
 	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);
@@ -367,12 +423,20 @@ local function message(attr, body)
 	end
 end
 local function iq(attr)
-	if attr and not attr.id then attr.id = new_id(); end
-	return new_stanza("iq", attr or { id = new_id() });
+	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) });
+	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 };
@@ -433,7 +497,6 @@ return {
 	stanza_mt = stanza_mt;
 	stanza = new_stanza;
 	is_stanza = is_stanza;
-	new_id = new_id;
 	preserialize = preserialize;
 	deserialize = deserialize;
 	clone = clone;