-- 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 lxp = require "lxp";
local st = require "util.stanza";
+local stanza_mt = st.stanza_mt;
+local error = error;
local tostring = tostring;
local t_insert = table.insert;
local t_concat = table.concat;
+local t_remove = table.remove;
+local setmetatable = setmetatable;
-local default_log = require "util.logger".init("xmlhandlers");
+-- COMPAT: w/LuaExpat 1.1.0
+local lxp_supports_doctype = pcall(lxp.new, { StartDoctypeDecl = false });
+local lxp_supports_xmldecl = pcall(lxp.new, { XmlDecl = false });
+local lxp_supports_bytecount = not not lxp.new({}).getcurrentbytecount;
-local error = error;
+local default_stanza_size_limit = 1024*1024*10; -- 10MB
module "xmppstream"
local new_parser = lxp.new;
-local ns_prefixes = {
- ["http://www.w3.org/XML/1998/namespace"] = "xml";
+local xml_namespace = {
+ ["http://www.w3.org/XML/1998/namespace\1lang"] = "xml:lang";
+ ["http://www.w3.org/XML/1998/namespace\1space"] = "xml:space";
+ ["http://www.w3.org/XML/1998/namespace\1base"] = "xml:base";
+ ["http://www.w3.org/XML/1998/namespace\1id"] = "xml:id";
};
local xmlns_streams = "http://etherx.jabber.org/streams";
local ns_separator = "\1";
local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$";
-function new_sax_handlers(session, stream_callbacks)
+_M.ns_separator = ns_separator;
+_M.ns_pattern = ns_pattern;
+
+local function dummy_cb() end
+
+function new_sax_handlers(session, stream_callbacks, cb_handleprogress)
local xml_handlers = {};
-
- local log = session.log or default_log;
-
+
local cb_streamopened = stream_callbacks.streamopened;
local cb_streamclosed = stream_callbacks.streamclosed;
- local cb_error = stream_callbacks.error or function(session, e) error("XML stream error: "..tostring(e)); end;
+ local cb_error = stream_callbacks.error or function(session, e, stanza) error("XML stream error: "..tostring(e)..(stanza and ": "..tostring(stanza) or ""),2); end;
local cb_handlestanza = stream_callbacks.handlestanza;
-
+ cb_handleprogress = cb_handleprogress or dummy_cb;
+
local stream_ns = stream_callbacks.stream_ns or xmlns_streams;
- local stream_tag = stream_ns..ns_separator..(stream_callbacks.stream_tag or "stream");
+ local stream_tag = stream_callbacks.stream_tag or "stream";
+ if stream_ns ~= "" then
+ stream_tag = stream_ns..ns_separator..stream_tag;
+ end
local stream_error_tag = stream_ns..ns_separator..(stream_callbacks.error_tag or "error");
-
+
local stream_default_ns = stream_callbacks.default_ns;
-
+
+ local stack = {};
local chardata, stanza = {};
+ local stanza_size = 0;
local non_streamns_depth = 0;
function xml_handlers:StartElement(tagname, attr)
if stanza and #chardata > 0 then
-- We have some character data in the buffer
- stanza:text(t_concat(chardata));
+ t_insert(stanza, t_concat(chardata));
chardata = {};
end
local curr_ns,name = tagname:match(ns_pattern);
attr.xmlns = curr_ns;
non_streamns_depth = non_streamns_depth + 1;
end
-
- -- FIXME !!!!!
+
for i=1,#attr do
local k = attr[i];
attr[i] = nil;
- local ns, nm = k:match(ns_pattern);
- if nm ~= "" then
- ns = ns_prefixes[ns];
- if ns then
- attr[ns..":"..nm] = attr[k];
- attr[k] = nil;
- end
+ local xmlk = xml_namespace[k];
+ if xmlk then
+ attr[xmlk] = attr[k];
+ attr[k] = nil;
end
end
-
+
if not stanza then --if we are not currently inside a stanza
+ if lxp_supports_bytecount then
+ stanza_size = self:getcurrentbytecount();
+ end
if session.notopen then
if tagname == stream_tag then
non_streamns_depth = 0;
if cb_streamopened then
+ if lxp_supports_bytecount then
+ cb_handleprogress(stanza_size);
+ stanza_size = 0;
+ end
cb_streamopened(session, attr);
end
else
if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
cb_error(session, "invalid-top-level-element");
end
-
- stanza = st.stanza(name, attr);
+
+ stanza = setmetatable({ name = name, attr = attr, tags = {} }, stanza_mt);
else -- we are inside a stanza, so add a tag
- stanza:tag(name, attr);
+ if lxp_supports_bytecount then
+ stanza_size = stanza_size + self:getcurrentbytecount();
+ end
+ t_insert(stack, stanza);
+ local oldstanza = stanza;
+ stanza = setmetatable({ name = name, attr = attr, tags = {} }, stanza_mt);
+ t_insert(oldstanza, stanza);
+ t_insert(oldstanza.tags, stanza);
+ end
+ end
+ if lxp_supports_xmldecl then
+ function xml_handlers:XmlDecl(version, encoding, standalone)
+ if lxp_supports_bytecount then
+ cb_handleprogress(self:getcurrentbytecount());
+ end
+ end
+ end
+ function xml_handlers:StartCdataSection()
+ if lxp_supports_bytecount then
+ if stanza then
+ stanza_size = stanza_size + self:getcurrentbytecount();
+ else
+ cb_handleprogress(self:getcurrentbytecount());
+ end
+ end
+ end
+ function xml_handlers:EndCdataSection()
+ if lxp_supports_bytecount then
+ if stanza then
+ stanza_size = stanza_size + self:getcurrentbytecount();
+ else
+ cb_handleprogress(self:getcurrentbytecount());
+ end
end
end
function xml_handlers:CharacterData(data)
if stanza then
+ if lxp_supports_bytecount then
+ stanza_size = stanza_size + self:getcurrentbytecount();
+ end
t_insert(chardata, data);
+ elseif lxp_supports_bytecount then
+ cb_handleprogress(self:getcurrentbytecount());
end
end
function xml_handlers:EndElement(tagname)
+ if lxp_supports_bytecount then
+ stanza_size = stanza_size + self:getcurrentbytecount()
+ end
if non_streamns_depth > 0 then
non_streamns_depth = non_streamns_depth - 1;
end
if stanza then
if #chardata > 0 then
-- We have some character data in the buffer
- stanza:text(t_concat(chardata));
+ t_insert(stanza, t_concat(chardata));
chardata = {};
end
-- Complete stanza
- if #stanza.last_add == 0 then
+ if #stack == 0 then
+ if lxp_supports_bytecount then
+ cb_handleprogress(stanza_size);
+ end
+ stanza_size = 0;
if tagname ~= stream_error_tag then
cb_handlestanza(session, stanza);
else
end
stanza = nil;
else
- stanza:up();
+ stanza = t_remove(stack);
end
else
- if tagname == stream_tag then
- if cb_streamclosed then
- cb_streamclosed(session);
- end
- else
- local curr_ns,name = tagname:match(ns_pattern);
- if name == "" then
- curr_ns, name = "", curr_ns;
- end
- cb_error(session, "parse-error", "unexpected-element-close", name);
+ if cb_streamclosed then
+ cb_streamclosed(session);
end
- stanza, chardata = nil, {};
end
end
-
+
+ local function restricted_handler(parser)
+ cb_error(session, "parse-error", "restricted-xml", "Restricted XML, see RFC 6120 section 11.1.");
+ if not parser.stop or not parser:stop() then
+ error("Failed to abort parsing");
+ end
+ end
+
+ if lxp_supports_doctype then
+ xml_handlers.StartDoctypeDecl = restricted_handler;
+ end
+ xml_handlers.Comment = restricted_handler;
+ xml_handlers.ProcessingInstruction = restricted_handler;
+
local function reset()
- stanza, chardata = nil, {};
+ stanza, chardata, stanza_size = nil, {}, 0;
+ stack = {};
end
-
+
local function set_session(stream, new_session)
session = new_session;
- log = new_session.log or default_log;
end
-
+
return xml_handlers, { reset = reset, set_session = set_session };
end
-function new(session, stream_callbacks)
- local handlers, meta = new_sax_handlers(session, stream_callbacks);
- local parser = new_parser(handlers, ns_separator);
+function new(session, stream_callbacks, stanza_size_limit)
+ -- Used to track parser progress (e.g. to enforce size limits)
+ local n_outstanding_bytes = 0;
+ local handle_progress;
+ if lxp_supports_bytecount then
+ function handle_progress(n_parsed_bytes)
+ n_outstanding_bytes = n_outstanding_bytes - n_parsed_bytes;
+ end
+ stanza_size_limit = stanza_size_limit or default_stanza_size_limit;
+ elseif stanza_size_limit then
+ error("Stanza size limits are not supported on this version of LuaExpat")
+ end
+
+ local handlers, meta = new_sax_handlers(session, stream_callbacks, handle_progress);
+ local parser = new_parser(handlers, ns_separator, false);
local parse = parser.parse;
+ function session.open_stream(session, from, to)
+ local send = session.sends2s or session.send;
+
+ local attr = {
+ ["xmlns:stream"] = "http://etherx.jabber.org/streams",
+ ["xml:lang"] = "en",
+ xmlns = stream_callbacks.default_ns,
+ version = session.version and (session.version > 0 and "1.0" or nil),
+ id = session.streamid or "",
+ from = from or session.host, to = to,
+ };
+ if session.stream_attrs then
+ session:stream_attrs(from, to, attr)
+ end
+ send("<?xml version='1.0'?>");
+ send(st.stanza("stream:stream", attr):top_tag());
+ return true;
+ end
+
return {
reset = function ()
- parser = new_parser(handlers, ns_separator);
+ parser = new_parser(handlers, ns_separator, false);
parse = parser.parse;
+ n_outstanding_bytes = 0;
meta.reset();
end,
feed = function (self, data)
- return parse(parser, data);
+ if lxp_supports_bytecount then
+ n_outstanding_bytes = n_outstanding_bytes + #data;
+ end
+ local ok, err = parse(parser, data);
+ if lxp_supports_bytecount and n_outstanding_bytes > stanza_size_limit then
+ return nil, "stanza-too-large";
+ end
+ return ok, err;
end,
set_session = meta.set_session;
};