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_ns..ns_separator..(stream_callbacks.stream_tag or "stream");
  49         local stream_error_tag = stream_ns..ns_separator..(stream_callbacks.error_tag or "error");
  50
  51         local stream_default_ns = stream_callbacks.default_ns;
  52
  53         local chardata, stanza = {};
  54         local non_streamns_depth = 0;
  55         function xml_handlers:StartElement(tagname, attr)
  56                 if stanza and #chardata > 0 then
  57                         -- We have some character data in the buffer
  58                         stanza:text(t_concat(chardata));
  59                         chardata = {};
  60                 end
  61                 local curr_ns,name = tagname:match(ns_pattern);
  62                 if name == "" then
  63                         curr_ns, name = "", curr_ns;
  64                 end
  65
  66                 if curr_ns ~= stream_default_ns or non_streamns_depth > 0 then
  67                         attr.xmlns = curr_ns;
  68                         non_streamns_depth = non_streamns_depth + 1;
  69                 end
  70
  71                 -- FIXME !!!!!
  72                 for i=1,#attr do
  73                         local k = attr[i];
  74                         attr[i] = nil;
  75                         local ns, nm = k:match(ns_pattern);
  76                         if nm ~= "" then
  77                                 ns = ns_prefixes[ns];
  78                                 if ns then
  79                                         attr[ns..":"..nm] = attr[k];
  80                                         attr[k] = nil;
  81                                 end
  82                         end
  83                 end
  84
  85                 if not stanza then --if we are not currently inside a stanza
  86                         if session.notopen then
  87                                 if tagname == stream_tag then
  88                                         non_streamns_depth = 0;
  89                                         if cb_streamopened then
  90                                                 cb_streamopened(session, attr);
  91                                         end
  92                                 else
  93                                         -- Garbage before stream?
  94                                         cb_error(session, "no-stream");
  95                                 end
  96                                 return;
  97                         end
  98                         if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
  99                                 cb_error(session, "invalid-top-level-element");
 100                         end
 101
 102                         stanza = st.stanza(name, attr);
 103                 else -- we are inside a stanza, so add a tag
 104                         stanza:tag(name, attr);
 105                 end
 106         end
 107         function xml_handlers:CharacterData(data)
 108                 if stanza then
 109                         t_insert(chardata, data);
 110                 end
 111         end
 112         function xml_handlers:EndElement(tagname)
 113                 if non_streamns_depth > 0 then
 114                         non_streamns_depth = non_streamns_depth - 1;
 115                 end
 116                 if stanza then
 117                         if #chardata > 0 then
 118                                 -- We have some character data in the buffer
 119                                 stanza:text(t_concat(chardata));
 120                                 chardata = {};
 121                         end
 122                         -- Complete stanza
 123                         local last_add = stanza.last_add;
 124                         if not last_add or #last_add == 0 then
 125                                 if tagname ~= stream_error_tag then
 126                                         cb_handlestanza(session, stanza);
 127                                 else
 128                                         cb_error(session, "stream-error", stanza);
 129                                 end
 130                                 stanza = nil;
 131                         else
 132                                 stanza:up();
 133                         end
 134                 else
 135                         if tagname == stream_tag then
 136                                 if cb_streamclosed then
 137                                         cb_streamclosed(session);
 138                                 end
 139                         else
 140                                 local curr_ns,name = tagname:match(ns_pattern);
 141                                 if name == "" then
 142                                         curr_ns, name = "", curr_ns;
 143                                 end
 144                                 cb_error(session, "parse-error", "unexpected-element-close", name);
 145                         end
 146                         stanza, chardata = nil, {};
 147                 end
 148         end
 149
 150         local function reset()
 151                 stanza, chardata = nil, {};
 152         end
 153
 154         local function set_session(stream, new_session)
 155                 session = new_session;
 156                 log = new_session.log or default_log;
 157         end
 158
 159         return xml_handlers, { reset = reset, set_session = set_session };
 160 end
 161
 162 function new(session, stream_callbacks)
 163         local handlers, meta = new_sax_handlers(session, stream_callbacks);
 164         local parser = new_parser(handlers, ns_separator);
 165         local parse = parser.parse;
 166
 167         return {
 168                 reset = function ()
 169                         parser = new_parser(handlers, ns_separator);
 170                         parse = parser.parse;
 171                         meta.reset();
 172                 end,
 173                 feed = function (self, data)
 174                         return parse(parser, data);
 175                 end,
 176                 set_session = meta.set_session;
 177         };
 178 end
 179
 180 return _M;