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 local stanza_mt = st.stanza_mt;
  13
  14 local tostring = tostring;
  15 local t_insert = table.insert;
  16 local t_concat = table.concat;
  17 local t_remove = table.remove;
  18 local setmetatable = setmetatable;
  19
  20 local default_log = require "util.logger".init("xmppstream");
  21
  22 local error = error;
  23
  24 module "xmppstream"
  25
  26 local new_parser = lxp.new;
  27
  28 local ns_prefixes = {
  29         ["http://www.w3.org/XML/1998/namespace"] = "xml";
  30 };
  31
  32 local xmlns_streams = "http://etherx.jabber.org/streams";
  33
  34 local ns_separator = "\1";
  35 local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$";
  36
  37 _M.ns_separator = ns_separator;
  38 _M.ns_pattern = ns_pattern;
  39
  40 function new_sax_handlers(session, stream_callbacks)
  41         local xml_handlers = {};
  42
  43         local log = session.log or default_log;
  44
  45         local cb_streamopened = stream_callbacks.streamopened;
  46         local cb_streamclosed = stream_callbacks.streamclosed;
  47         local cb_error = stream_callbacks.error or function(session, e) error("XML stream error: "..tostring(e)); end;
  48         local cb_handlestanza = stream_callbacks.handlestanza;
  49
  50         local stream_ns = stream_callbacks.stream_ns or xmlns_streams;
  51         local stream_tag = stream_callbacks.stream_tag or "stream";
  52         if stream_ns ~= "" then
  53                 stream_tag = stream_ns..ns_separator..stream_tag;
  54         end
  55         local stream_error_tag = stream_ns..ns_separator..(stream_callbacks.error_tag or "error");
  56
  57         local stream_default_ns = stream_callbacks.default_ns;
  58
  59         local stack = {};
  60         local chardata, stanza = {};
  61         local non_streamns_depth = 0;
  62         function xml_handlers:StartElement(tagname, attr)
  63                 if stanza and #chardata > 0 then
  64                         -- We have some character data in the buffer
  65                         t_insert(stanza, t_concat(chardata));
  66                         chardata = {};
  67                 end
  68                 local curr_ns,name = tagname:match(ns_pattern);
  69                 if name == "" then
  70                         curr_ns, name = "", curr_ns;
  71                 end
  72
  73                 if curr_ns ~= stream_default_ns or non_streamns_depth > 0 then
  74                         attr.xmlns = curr_ns;
  75                         non_streamns_depth = non_streamns_depth + 1;
  76                 end
  77
  78                 -- FIXME !!!!!
  79                 for i=1,#attr do
  80                         local k = attr[i];
  81                         attr[i] = nil;
  82                         local ns, nm = k:match(ns_pattern);
  83                         if nm ~= "" then
  84                                 ns = ns_prefixes[ns];
  85                                 if ns then
  86                                         attr[ns..":"..nm] = attr[k];
  87                                         attr[k] = nil;
  88                                 end
  89                         end
  90                 end
  91
  92                 if not stanza then --if we are not currently inside a stanza
  93                         if session.notopen then
  94                                 if tagname == stream_tag then
  95                                         non_streamns_depth = 0;
  96                                         if cb_streamopened then
  97                                                 cb_streamopened(session, attr);
  98                                         end
  99                                 else
 100                                         -- Garbage before stream?
 101                                         cb_error(session, "no-stream");
 102                                 end
 103                                 return;
 104                         end
 105                         if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
 106                                 cb_error(session, "invalid-top-level-element");
 107                         end
 108
 109                         stanza = setmetatable({ name = name, attr = attr, tags = {} }, stanza_mt);
 110                 else -- we are inside a stanza, so add a tag
 111                         t_insert(stack, stanza);
 112                         local oldstanza = stanza;
 113                         stanza = setmetatable({ name = name, attr = attr, tags = {} }, stanza_mt);
 114                         t_insert(oldstanza, stanza);
 115                         t_insert(oldstanza.tags, stanza);
 116                 end
 117         end
 118         function xml_handlers:CharacterData(data)
 119                 if stanza then
 120                         t_insert(chardata, data);
 121                 end
 122         end
 123         function xml_handlers:EndElement(tagname)
 124                 if non_streamns_depth > 0 then
 125                         non_streamns_depth = non_streamns_depth - 1;
 126                 end
 127                 if stanza then
 128                         if #chardata > 0 then
 129                                 -- We have some character data in the buffer
 130                                 t_insert(stanza, t_concat(chardata));
 131                                 chardata = {};
 132                         end
 133                         -- Complete stanza
 134                         if #stack == 0 then
 135                                 if tagname ~= stream_error_tag then
 136                                         cb_handlestanza(session, stanza);
 137                                 else
 138                                         cb_error(session, "stream-error", stanza);
 139                                 end
 140                                 stanza = nil;
 141                         else
 142                                 stanza = t_remove(stack);
 143                         end
 144                 else
 145                         if tagname == stream_tag then
 146                                 if cb_streamclosed then
 147                                         cb_streamclosed(session);
 148                                 end
 149                         else
 150                                 local curr_ns,name = tagname:match(ns_pattern);
 151                                 if name == "" then
 152                                         curr_ns, name = "", curr_ns;
 153                                 end
 154                                 cb_error(session, "parse-error", "unexpected-element-close", name);
 155                         end
 156                         stanza, chardata = nil, {};
 157                         stack = {};
 158                 end
 159         end
 160
 161         local function reset()
 162                 stanza, chardata = nil, {};
 163                 stack = {};
 164         end
 165
 166         local function set_session(stream, new_session)
 167                 session = new_session;
 168                 log = new_session.log or default_log;
 169         end
 170
 171         return xml_handlers, { reset = reset, set_session = set_session };
 172 end
 173
 174 function new(session, stream_callbacks)
 175         local handlers, meta = new_sax_handlers(session, stream_callbacks);
 176         local parser = new_parser(handlers, ns_separator);
 177         local parse = parser.parse;
 178
 179         return {
 180                 reset = function ()
 181                         parser = new_parser(handlers, ns_separator);
 182                         parse = parser.parse;
 183                         meta.reset();
 184                 end,
 185                 feed = function (self, data)
 186                         return parse(parser, data);
 187                 end,
 188                 set_session = meta.set_session;
 189         };
 190 end
 191
 192 return _M;