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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 lxp = require "lxp";
local st = require "util.stanza";
local stanza_mt = st.stanza_mt;
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("xmppstream");
-- COMPAT: w/LuaExpat 1.1.0
local lxp_supports_doctype = pcall(lxp.new, { StartDoctypeDecl = false });
if not lxp_supports_doctype then
default_log("warn", "The version of LuaExpat on your system leaves Prosody "
.."vulnerable to denial-of-service attacks. You should upgrade to "
.."LuaExpat 1.1.1 or higher as soon as possible. See "
.."http://prosody.im/doc/depends#luaexpat for more information.");
end
local error = error;
module "xmppstream"
local new_parser = lxp.new;
local ns_prefixes = {
["http://www.w3.org/XML/1998/namespace"] = "xml";
};
local xmlns_streams = "http://etherx.jabber.org/streams";
local ns_separator = "\1";
local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$";
_M.ns_separator = ns_separator;
_M.ns_pattern = ns_pattern;
function new_sax_handlers(session, stream_callbacks)
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_handlestanza = stream_callbacks.handlestanza;
local stream_ns = stream_callbacks.stream_ns or xmlns_streams;
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 non_streamns_depth = 0;
function xml_handlers:StartElement(tagname, attr)
if stanza and #chardata > 0 then
-- We have some character data in the buffer
t_insert(stanza, t_concat(chardata));
chardata = {};
end
local curr_ns,name = tagname:match(ns_pattern);
if name == "" then
curr_ns, name = "", curr_ns;
end
if curr_ns ~= stream_default_ns or non_streamns_depth > 0 then
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
end
end
if not stanza then --if we are not currently inside a stanza
if session.notopen then
if tagname == stream_tag then
non_streamns_depth = 0;
if cb_streamopened then
cb_streamopened(session, attr);
end
else
-- Garbage before stream?
cb_error(session, "no-stream");
end
return;
end
if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
cb_error(session, "invalid-top-level-element");
end
stanza = setmetatable({ name = name, attr = attr, tags = {} }, stanza_mt);
else -- we are inside a stanza, so add a tag
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
function xml_handlers:CharacterData(data)
if stanza then
t_insert(chardata, data);
end
end
function xml_handlers:EndElement(tagname)
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
t_insert(stanza, t_concat(chardata));
chardata = {};
end
-- Complete stanza
if #stack == 0 then
if tagname ~= stream_error_tag then
cb_handlestanza(session, stanza);
else
cb_error(session, "stream-error", stanza);
end
stanza = nil;
else
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);
end
stanza, chardata = nil, {};
stack = {};
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() 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, {};
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);
local parse = parser.parse;
return {
reset = function ()
parser = new_parser(handlers, ns_separator);
parse = parser.parse;
meta.reset();
end,
feed = function (self, data)
return parse(parser, data);
end,
set_session = meta.set_session;
};
end
return _M;
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