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