plugins/mod_component.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 module:set_global();
  10
  11 local t_concat = table.concat;
  12
  13 local logger = require "util.logger";
  14 local sha1 = require "util.hashes".sha1;
  15 local st = require "util.stanza";
  16
  17 local jid_split = require "util.jid".split;
  18 local new_xmpp_stream = require "util.xmppstream".new;
  19 local uuid_gen = require "util.uuid".generate;
  20
  21
  22 local log = module._log;
  23
  24 local sessions = module:shared("sessions");
  25
  26 function module.add_host(module)
  27         if module:get_host_type() ~= "component" then
  28                 error("Don't load mod_component manually, it should be for a component, please see http://prosody.im/doc/components", 0);
  29         end
  30
  31         local env = module.environment;
  32         env.connected = false;
  33
  34         local send;
  35
  36         local function on_destroy(session, err)
  37                 env.connected = false;
  38                 send = nil;
  39                 session.on_destroy = nil;
  40         end
  41
  42         -- Handle authentication attempts by component
  43         local function handle_component_auth(event)
  44                 local session, stanza = event.origin, event.stanza;
  45
  46                 if session.type ~= "component" then return; end
  47
  48                 if (not session.host) or #stanza.tags > 0 then
  49                         (session.log or log)("warn", "Invalid component handshake for host: %s", session.host);
  50                         session:close("not-authorized");
  51                         return true;
  52                 end
  53
  54                 local secret = module:get_option("component_secret");
  55                 if not secret then
  56                         (session.log or log)("warn", "Component attempted to identify as %s, but component_secret is not set", session.host);
  57                         session:close("not-authorized");
  58                         return true;
  59                 end
  60
  61                 local supplied_token = t_concat(stanza);
  62                 local calculated_token = sha1(session.streamid..secret, true);
  63                 if supplied_token:lower() ~= calculated_token:lower() then
  64                         module:log("info", "Component authentication failed for %s", session.host);
  65                         session:close{ condition = "not-authorized", text = "Given token does not match calculated token" };
  66                         return true;
  67                 end
  68
  69                 if env.connected then
  70                         module:log("error", "Second component attempted to connect, denying connection");
  71                         session:close{ condition = "conflict", text = "Component already connected" };
  72                         return true;
  73                 end
  74
  75                 env.connected = true;
  76                 send = session.send;
  77                 session.on_destroy = on_destroy;
  78                 session.component_validate_from = module:get_option_boolean("validate_from_addresses", true);
  79                 module:log("info", "External component successfully authenticated");
  80                 session.send(st.stanza("handshake"));
  81
  82                 return true;
  83         end
  84         module:hook("stanza/jabber:component:accept:handshake", handle_component_auth);
  85
  86         -- Handle stanzas addressed to this component
  87         local function handle_stanza(event)
  88                 local stanza = event.stanza;
  89                 if send then
  90                         stanza.attr.xmlns = nil;
  91                         send(stanza);
  92                 else
  93                         module:log("warn", "Component not connected, bouncing error for: %s", stanza:top_tag());
  94                         if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then
  95                                 event.origin.send(st.error_reply(stanza, "wait", "service-unavailable", "Component unavailable"));
  96                         end
  97                 end
  98                 return true;
  99         end
 100
 101         module:hook("iq/bare", handle_stanza, -1);
 102         module:hook("message/bare", handle_stanza, -1);
 103         module:hook("presence/bare", handle_stanza, -1);
 104         module:hook("iq/full", handle_stanza, -1);
 105         module:hook("message/full", handle_stanza, -1);
 106         module:hook("presence/full", handle_stanza, -1);
 107         module:hook("iq/host", handle_stanza, -1);
 108         module:hook("message/host", handle_stanza, -1);
 109         module:hook("presence/host", handle_stanza, -1);
 110 end
 111
 112 --- Network and stream part ---
 113
 114 local xmlns_component = 'jabber:component:accept';
 115
 116 local listener = {};
 117
 118 --- Callbacks/data for xmppstream to handle streams for us ---
 119
 120 local stream_callbacks = { default_ns = xmlns_component };
 121
 122 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
 123
 124 function stream_callbacks.error(session, error, data, data2)
 125         if session.destroyed then return; end
 126         module:log("warn", "Error processing component stream: "..tostring(error));
 127         if error == "no-stream" then
 128                 session:close("invalid-namespace");
 129         elseif error == "parse-error" then
 130                 session.log("warn", "External component %s XML parse error: %s", tostring(session.host), tostring(data));
 131                 session:close("not-well-formed");
 132         elseif error == "stream-error" then
 133                 local condition, text = "undefined-condition";
 134                 for child in data:children() do
 135                         if child.attr.xmlns == xmlns_xmpp_streams then
 136                                 if child.name ~= "text" then
 137                                         condition = child.name;
 138                                 else
 139                                         text = child:get_text();
 140                                 end
 141                                 if condition ~= "undefined-condition" and text then
 142                                         break;
 143                                 end
 144                         end
 145                 end
 146                 text = condition .. (text and (" ("..text..")") or "");
 147                 session.log("info", "Session closed by remote with error: %s", text);
 148                 session:close(nil, text);
 149         end
 150 end
 151
 152 function stream_callbacks.streamopened(session, attr)
 153         if not hosts[attr.to] or not hosts[attr.to].modules.component then
 154                 session:close{ condition = "host-unknown", text = tostring(attr.to).." does not match any configured external components" };
 155                 return;
 156         end
 157         session.host = attr.to;
 158         session.streamid = uuid_gen();
 159         session.notopen = nil;
 160         -- Return stream header
 161         session.send(st.stanza("stream:stream", { xmlns=xmlns_component,
 162                         ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.host }):top_tag());
 163 end
 164
 165 function stream_callbacks.streamclosed(session)
 166         session.log("debug", "Received </stream:stream>");
 167         session:close();
 168 end
 169
 170 local core_process_stanza = core_process_stanza;
 171
 172 function stream_callbacks.handlestanza(session, stanza)
 173         -- Namespaces are icky.
 174         if not stanza.attr.xmlns and stanza.name == "handshake" then
 175                 stanza.attr.xmlns = xmlns_component;
 176         end
 177         if not stanza.attr.xmlns or stanza.attr.xmlns == "jabber:client" then
 178                 local from = stanza.attr.from;
 179                 if from then
 180                         if session.component_validate_from then
 181                                 local _, domain = jid_split(stanza.attr.from);
 182                                 if domain ~= session.host then
 183                                         -- Return error
 184                                         session.log("warn", "Component sent stanza with missing or invalid 'from' address");
 185                                         session:close{
 186                                                 condition = "invalid-from";
 187                                                 text = "Component tried to send from address <"..tostring(from)
 188                                                            .."> which is not in domain <"..tostring(session.host)..">";
 189                                         };
 190                                         return;
 191                                 end
 192                         end
 193                 else
 194                         stanza.attr.from = session.host; -- COMPAT: Strictly we shouldn't allow this
 195                 end
 196                 if not stanza.attr.to then
 197                         session.log("warn", "Rejecting stanza with no 'to' address");
 198                         session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST specify a 'to' address on stanzas"));
 199                         return;
 200                 end
 201         end
 202         return core_process_stanza(session, stanza);
 203 end
 204
 205 --- Closing a component connection
 206 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 207 local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };
 208 local function session_close(session, reason)
 209         if session.destroyed then return; end
 210         if session.conn then
 211                 if session.notopen then
 212                         session.send("<?xml version='1.0'?>");
 213                         session.send(st.stanza("stream:stream", default_stream_attr):top_tag());
 214                 end
 215                 if reason then
 216                         if type(reason) == "string" then -- assume stream error
 217                                 module:log("info", "Disconnecting component, <stream:error> is: %s", reason);
 218                                 session.send(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
 219                         elseif type(reason) == "table" then
 220                                 if reason.condition then
 221                                         local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
 222                                         if reason.text then
 223                                                 stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
 224                                         end
 225                                         if reason.extra then
 226                                                 stanza:add_child(reason.extra);
 227                                         end
 228                                         module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(stanza));
 229                                         session.send(stanza);
 230                                 elseif reason.name then -- a stanza
 231                                         module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(reason));
 232                                         session.send(reason);
 233                                 end
 234                         end
 235                 end
 236                 session.send("</stream:stream>");
 237                 session.conn:close();
 238                 listener.ondisconnect(session.conn, "stream error");
 239         end
 240 end
 241
 242 --- Component connlistener
 243
 244 function listener.onconnect(conn)
 245         local _send = conn.write;
 246         local session = { type = "component", conn = conn, send = function (data) return _send(conn, tostring(data)); end };
 247
 248         -- Logging functions --
 249         local conn_name = "jcp"..tostring(conn):match("[a-f0-9]+$");
 250         session.log = logger.init(conn_name);
 251         session.close = session_close;
 252
 253         session.log("info", "Incoming Jabber component connection");
 254
 255         local stream = new_xmpp_stream(session, stream_callbacks);
 256         session.stream = stream;
 257
 258         session.notopen = true;
 259
 260         function session.reset_stream()
 261                 session.notopen = true;
 262                 session.stream:reset();
 263         end
 264
 265         function session.data(conn, data)
 266                 local ok, err = stream:feed(data);
 267                 if ok then return; end
 268                 module:log("debug", "Received invalid XML (%s) %d bytes: %s", tostring(err), #data, data:sub(1, 300):gsub("[\r\n]+", " "):gsub("[%z\1-\31]", "_"));
 269                 session:close("not-well-formed");
 270         end
 271
 272         session.dispatch_stanza = stream_callbacks.handlestanza;
 273
 274         sessions[conn] = session;
 275 end
 276 function listener.onincoming(conn, data)
 277         local session = sessions[conn];
 278         session.data(conn, data);
 279 end
 280 function listener.ondisconnect(conn, err)
 281         local session = sessions[conn];
 282         if session then
 283                 (session.log or log)("info", "component disconnected: %s (%s)", tostring(session.host), tostring(err));
 284                 if session.on_destroy then session:on_destroy(err); end
 285                 sessions[conn] = nil;
 286                 for k in pairs(session) do
 287                         if k ~= "log" and k ~= "close" then
 288                                 session[k] = nil;
 289                         end
 290                 end
 291                 session.destroyed = true;
 292                 session = nil;
 293         end
 294 end
 295
 296 module:add_item("net-provider", {
 297         name = "component";
 298         listener = listener;
 299         default_port = 5347;
 300         multiplex = {
 301                 pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:component%1.*>";
 302         };
 303 });