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("xmlhandlers");
  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 function new_sax_handlers(session, stream_callbacks)
  35         local xml_handlers = {};
  36
  37         local log = session.log or default_log;
  38
  39         local cb_streamopened = stream_callbacks.streamopened;
  40         local cb_streamclosed = stream_callbacks.streamclosed;
  41         local cb_error = stream_callbacks.error or function(session, e) error("XML stream error: "..tostring(e)); end;
  42         local cb_handlestanza = stream_callbacks.handlestanza;
  43
  44         local stream_ns = stream_callbacks.stream_ns or xmlns_streams;
  45         local stream_tag = stream_ns..ns_separator..(stream_callbacks.stream_tag or "stream");
  46         local stream_error_tag = stream_ns..ns_separator..(stream_callbacks.error_tag or "error");
  47
  48         local stream_default_ns = stream_callbacks.default_ns;
  49
  50         local chardata, stanza = {};
  51         function xml_handlers:StartElement(tagname, attr)
  52                 if stanza and #chardata > 0 then
  53                         -- We have some character data in the buffer
  54                         stanza:text(t_concat(chardata));
  55                         chardata = {};
  56                 end
  57                 local curr_ns,name = tagname:match(ns_pattern);
  58                 if name == "" then
  59                         curr_ns, name = "", curr_ns;
  60                 end
  61
  62                 if curr_ns ~= stream_default_ns then
  63                         attr.xmlns = curr_ns;
  64                 end
  65
  66                 -- FIXME !!!!!
  67                 for i=1,#attr do
  68                         local k = attr[i];
  69                         attr[i] = nil;
  70                         local ns, nm = k:match(ns_pattern);
  71                         if nm ~= "" then
  72                                 ns = ns_prefixes[ns];
  73                                 if ns then
  74                                         attr[ns..":"..nm] = attr[k];
  75                                         attr[k] = nil;
  76                                 end
  77                         end
  78                 end
  79
  80                 if not stanza then --if we are not currently inside a stanza
  81                         if session.notopen then
  82                                 if tagname == stream_tag then
  83                                         if cb_streamopened then
  84                                                 cb_streamopened(session, attr);
  85                                         end
  86                                 else
  87                                         -- Garbage before stream?
  88                                         cb_error(session, "no-stream");
  89                                 end
  90                                 return;
  91                         end
  92                         if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
  93                                 cb_error(session, "invalid-top-level-element");
  94                         end
  95
  96                         stanza = st.stanza(name, attr);
  97                 else -- we are inside a stanza, so add a tag
  98                         stanza:tag(name, attr);
  99                 end
 100         end
 101         function xml_handlers:CharacterData(data)
 102                 if stanza then
 103                         t_insert(chardata, data);
 104                 end
 105         end
 106         function xml_handlers:EndElement(tagname)
 107                 if stanza then
 108                         if #chardata > 0 then
 109                                 -- We have some character data in the buffer
 110                                 stanza:text(t_concat(chardata));
 111                                 chardata = {};
 112                         end
 113                         -- Complete stanza
 114                         if #stanza.last_add == 0 then
 115                                 if tagname ~= stream_error_tag then
 116                                         cb_handlestanza(session, stanza);
 117                                 else
 118                                         cb_error(session, "stream-error", stanza);
 119                                 end
 120                                 stanza = nil;
 121                         else
 122                                 stanza:up();
 123                         end
 124                 else
 125                         if tagname == stream_tag then
 126                                 if cb_streamclosed then
 127                                         cb_streamclosed(session);
 128                                 end
 129                         else
 130                                 local curr_ns,name = tagname:match(ns_pattern);
 131                                 if name == "" then
 132                                         curr_ns, name = "", curr_ns;
 133                                 end
 134                                 cb_error(session, "parse-error", "unexpected-element-close", name);
 135                         end
 136                         stanza, chardata = nil, {};
 137                 end
 138         end
 139
 140         local function reset()
 141                 stanza, chardata = nil, {};
 142         end
 143
 144         local function set_session(stream, new_session)
 145                 session = new_session;
 146                 log = new_session.log or default_log;
 147         end
 148
 149         return xml_handlers, { reset = reset, set_session = set_session };
 150 end
 151
 152 function new(session, stream_callbacks)
 153         local handlers, meta = new_sax_handlers(session, stream_callbacks);
 154         local parser = new_parser(handlers, ns_separator);
 155         local parse = parser.parse;
 156
 157         return {
 158                 reset = function ()
 159                         parser = new_parser(handlers, ns_separator);
 160                         parse = parser.parse;
 161                         meta.reset();
 162                 end,
 163                 feed = function (self, data)
 164                         return parse(parser, data);
 165                 end,
 166                 set_session = meta.set_session;
 167         };
 168 end
 169
 170 return _M;