diff options
Diffstat (limited to 'util/xmppstream.lua')
| -rw-r--r-- | util/xmppstream.lua | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/util/xmppstream.lua b/util/xmppstream.lua new file mode 100644 index 00000000..69e7690d --- /dev/null +++ b/util/xmppstream.lua @@ -0,0 +1,206 @@ +-- 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 tostring = tostring; +local t_insert = table.insert; +local t_concat = table.concat; + +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 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 + stanza:text(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 = st.stanza(name, attr); + else -- we are inside a stanza, so add a tag + stanza:tag(name, attr); + 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 + stanza:text(t_concat(chardata)); + chardata = {}; + end + -- Complete stanza + local last_add = stanza.last_add; + if not last_add or #last_add == 0 then + if tagname ~= stream_error_tag then + cb_handlestanza(session, stanza); + else + cb_error(session, "stream-error", stanza); + end + stanza = nil; + else + stanza:up(); + 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, {}; + 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, {}; + 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; |