diff options
| -rw-r--r-- | util/xmppstream.lua | 86 |
1 files changed, 80 insertions, 6 deletions
diff --git a/util/xmppstream.lua b/util/xmppstream.lua index 4909678c..9cdd6471 100644 --- a/util/xmppstream.lua +++ b/util/xmppstream.lua @@ -6,7 +6,6 @@ -- COPYING file in the source package for more information. -- - local lxp = require "lxp"; local st = require "util.stanza"; local stanza_mt = st.stanza_mt; @@ -20,6 +19,10 @@ 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 module "xmppstream" @@ -40,13 +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 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"; @@ -59,6 +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 @@ -87,10 +94,17 @@ function new_sax_handlers(session, stream_callbacks) 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 @@ -105,6 +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); @@ -112,12 +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 + #data --self:getcurrentbytecount(); + end t_insert(chardata, data); + elseif lxp_supports_bytecount then + cb_handleprogress(#data--[[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 @@ -129,6 +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 @@ -159,7 +213,7 @@ 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 @@ -170,8 +224,20 @@ function new_sax_handlers(session, stream_callbacks) return xml_handlers, { reset = reset, set_session = set_session }; end -function new(session, stream_callbacks) - local handlers, meta = new_sax_handlers(session, stream_callbacks); +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); local parse = parser.parse; @@ -179,10 +245,18 @@ function new(session, stream_callbacks) reset = function () parser = new_parser(handlers, ns_separator); 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; }; |