-- 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; -- 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 default_stanza_size_limit = 1024*1024*10; -- 10MB local _ENV = nil; local new_parser = lxp.new; 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.."?(.*)$"; local function dummy_cb() end local function new_sax_handlers(session, stream_callbacks, cb_handleprogress) local xml_handlers = {}; local cb_streamopened = stream_callbacks.streamopened; local cb_streamclosed = stream_callbacks.streamclosed; 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_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 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 for i=1,#attr do local k = attr[i]; attr[i] = nil; 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 -- Garbage before stream? cb_error(session, "no-stream", tagname); 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 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 t_insert(stanza, t_concat(chardata)); chardata = {}; end -- Complete stanza 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 cb_error(session, "stream-error", stanza); end stanza = nil; else stanza = t_remove(stack); end else if cb_streamclosed then cb_streamclosed(session); end 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, stanza_size = nil, {}, 0; stack = {}; end local function set_session(stream, new_session) session = new_session; end return xml_handlers, { reset = reset, set_session = set_session }; end local 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, 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, false); parse = parser.parse; n_outstanding_bytes = 0; meta.reset(); end, feed = function (self, 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; }; end return { ns_separator = ns_separator; ns_pattern = ns_pattern; new_sax_handlers = new_sax_handlers; new = new; };