X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=util%2Fxmppstream.lua;h=138c86b744832b4e45f98798e64caf30fac664b5;hb=533fc1fa57ce10fc0821f8edaeb247f2710a543c;hp=cf485daceb5e1000c2fe1feb957b2b365469e839;hpb=1881612f6e77c771984d73b85704e89818a82977;p=prosody.git diff --git a/util/xmppstream.lua b/util/xmppstream.lua index cf485dac..138c86b7 100644 --- a/util/xmppstream.lua +++ b/util/xmppstream.lua @@ -6,37 +6,33 @@ -- 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("xmppstream"); - -- 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; -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; +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"; @@ -47,15 +43,16 @@ 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 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_callbacks.stream_tag or "stream"; @@ -68,6 +65,7 @@ function new_sax_handlers(session, stream_callbacks) 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 @@ -85,30 +83,33 @@ function new_sax_handlers(session, stream_callbacks) 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 -- Garbage before stream? - cb_error(session, "no-stream"); + cb_error(session, "no-stream", tagname); end return; end @@ -118,6 +119,9 @@ function new_sax_handlers(session, stream_callbacks) 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); @@ -125,12 +129,45 @@ function new_sax_handlers(session, stream_callbacks) 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 @@ -142,6 +179,10 @@ function new_sax_handlers(session, stream_callbacks) 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 @@ -152,24 +193,17 @@ function new_sax_handlers(session, stream_callbacks) 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, {}; - stack = {}; end end - - local function restricted_handler() + + 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 @@ -179,31 +213,50 @@ function new_sax_handlers(session, stream_callbacks) 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; 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; };