util/xmppstream.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9
  10 local lxp = require "lxp";
  11 local st = require "util.stanza";
  12
  13 local tostring = tostring;
  14 local t_insert = table.insert;
  15 local t_concat = table.concat;
  16
  17 local default_log = require "util.logger".init("xmppstream");
  18
  19 local error = error;
  20
  21 module "xmppstream"
  22
  23 local new_parser = lxp.new;
  24
  25 local ns_prefixes = {
  26         ["http://www.w3.org/XML/1998/namespace"] = "xml";
  27 };
  28
  29 local xmlns_streams = "http://etherx.jabber.org/streams";
  30
  31 local ns_separator = "\1";
  32 local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$";
  33
  34 _M.ns_separator = ns_separator;
  35 _M.ns_pattern = ns_pattern;
  36
  37 function new_sax_handlers(session, stream_callbacks)
  38         local xml_handlers = {};
  39
  40         local log = session.log or default_log;
  41
  42         local cb_streamopened = stream_callbacks.streamopened;
  43         local cb_streamclosed = stream_callbacks.streamclosed;
  44         local cb_error = stream_callbacks.error or function(session, e) error("XML stream error: "..tostring(e)); end;
  45         local cb_handlestanza = stream_callbacks.handlestanza;
  46
  47         local stream_ns = stream_callbacks.stream_ns or xmlns_streams;
  48         local stream_tag = stream_callbacks.stream_tag or "stream";
  49         if stream_ns ~= "" then
  50                 stream_tag = stream_ns..ns_separator..stream_tag;
  51         end
  52         local stream_error_tag = stream_ns..ns_separator..(stream_callbacks.error_tag or "error");
  53
  54         local stream_default_ns = stream_callbacks.default_ns;
  55
  56         local chardata, stanza = {};
  57         local non_streamns_depth = 0;
  58         function xml_handlers:StartElement(tagname, attr)
  59                 if stanza and #chardata > 0 then
  60                         -- We have some character data in the buffer
  61                         stanza:text(t_concat(chardata));
  62                         chardata = {};
  63                 end
  64                 local curr_ns,name = tagname:match(ns_pattern);
  65                 if name == "" then
  66                         curr_ns, name = "", curr_ns;
  67                 end
  68
  69                 if curr_ns ~= stream_default_ns or non_streamns_depth > 0 then
  70                         attr.xmlns = curr_ns;
  71                         non_streamns_depth = non_streamns_depth + 1;
  72                 end
  73
  74                 -- FIXME !!!!!
  75                 for i=1,#attr do
  76                         local k = attr[i];
  77                         attr[i] = nil;
  78                         local ns, nm = k:match(ns_pattern);
  79                         if nm ~= "" then
  80                                 ns = ns_prefixes[ns];
  81                                 if ns then
  82                                         attr[ns..":"..nm] = attr[k];
  83                                         attr[k] = nil;
  84                                 end
  85                         end
  86                 end
  87
  88                 if not stanza then --if we are not currently inside a stanza
  89                         if session.notopen then
  90                                 if tagname == stream_tag then
  91                                         non_streamns_depth = 0;
  92                                         if cb_streamopened then
  93                                                 cb_streamopened(session, attr);
  94                                         end
  95                                 else
  96                                         -- Garbage before stream?
  97                                         cb_error(session, "no-stream");
  98                                 end
  99                                 return;
 100                         end
 101                         if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
 102                                 cb_error(session, "invalid-top-level-element");
 103                         end
 104
 105                         stanza = st.stanza(name, attr);
 106                 else -- we are inside a stanza, so add a tag
 107                         stanza:tag(name, attr);
 108                 end
 109         end
 110         function xml_handlers:CharacterData(data)
 111                 if stanza then
 112                         t_insert(chardata, data);
 113                 end
 114         end
 115         function xml_handlers:EndElement(tagname)
 116                 if non_streamns_depth > 0 then
 117                         non_streamns_depth = non_streamns_depth - 1;
 118                 end
 119                 if stanza then
 120                         if #chardata > 0 then
 121                                 -- We have some character data in the buffer
 122                                 stanza:text(t_concat(chardata));
 123                                 chardata = {};
 124                         end
 125                         -- Complete stanza
 126                         local last_add = stanza.last_add;
 127                         if not last_add or #last_add == 0 then
 128                                 if tagname ~= stream_error_tag then
 129                                         cb_handlestanza(session, stanza);
 130                                 else
 131                                         cb_error(session, "stream-error", stanza);
 132                                 end
 133                                 stanza = nil;
 134                         else
 135                                 stanza:up();
 136                         end
 137                 else
 138                         if tagname == stream_tag then
 139                                 if cb_streamclosed then
 140                                         cb_streamclosed(session);
 141                                 end
 142                         else
 143                                 local curr_ns,name = tagname:match(ns_pattern);
 144                                 if name == "" then
 145                                         curr_ns, name = "", curr_ns;
 146                                 end
 147                                 cb_error(session, "parse-error", "unexpected-element-close", name);
 148                         end
 149                         stanza, chardata = nil, {};
 150                 end
 151         end
 152
 153         local function reset()
 154                 stanza, chardata = nil, {};
 155         end
 156
 157         local function set_session(stream, new_session)
 158                 session = new_session;
 159                 log = new_session.log or default_log;
 160         end
 161
 162         return xml_handlers, { reset = reset, set_session = set_session };
 163 end
 164
 165 function new(session, stream_callbacks)
 166         local handlers, meta = new_sax_handlers(session, stream_callbacks);
 167         local parser = new_parser(handlers, ns_separator);
 168         local parse = parser.parse;
 169
 170         return {
 171                 reset = function ()
 172                         parser = new_parser(handlers, ns_separator);
 173                         parse = parser.parse;
 174                         meta.reset();
 175                 end,
 176                 feed = function (self, data)
 177                         return parse(parser, data);
 178                 end,
 179                 set_session = meta.set_session;
 180         };
 181 end
 182
 183 return _M;