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_unauthed" 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                 session.type = "component";
  80                 module:log("info", "External component successfully authenticated");
  81                 session.send(st.stanza("handshake"));
  82
  83                 return true;
  84         end
  85         module:hook("stanza/jabber:component:accept:handshake", handle_component_auth);
  86
  87         -- Handle stanzas addressed to this component
  88         local function handle_stanza(event)
  89                 local stanza = event.stanza;
  90                 if send then
  91                         stanza.attr.xmlns = nil;
  92                         send(stanza);
  93                 else
  94                         module:log("warn", "Component not connected, bouncing error for: %s", stanza:top_tag());
  95                         if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then
  96                                 event.origin.send(st.error_reply(stanza, "wait", "service-unavailable", "Component unavailable"));
  97                         end
  98                 end
  99                 return true;
 100         end
 101
 102         module:hook("iq/bare", handle_stanza, -1);
 103         module:hook("message/bare", handle_stanza, -1);
 104         module:hook("presence/bare", handle_stanza, -1);
 105         module:hook("iq/full", handle_stanza, -1);
 106         module:hook("message/full", handle_stanza, -1);
 107         module:hook("presence/full", handle_stanza, -1);
 108         module:hook("iq/host", handle_stanza, -1);
 109         module:hook("message/host", handle_stanza, -1);
 110         module:hook("presence/host", handle_stanza, -1);
 111 end
 112
 113 --- Network and stream part ---
 114
 115 local xmlns_component = 'jabber:component:accept';
 116
 117 local listener = {};
 118
 119 --- Callbacks/data for xmppstream to handle streams for us ---
 120
 121 local stream_callbacks = { default_ns = xmlns_component };
 122
 123 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
 124
 125 function stream_callbacks.error(session, error, data, data2)
 126         if session.destroyed then return; end
 127         module:log("warn", "Error processing component stream: "..tostring(error));
 128         if error == "no-stream" then
 129                 session:close("invalid-namespace");
 130         elseif error == "parse-error" then
 131                 session.log("warn", "External component %s XML parse error: %s", tostring(session.host), tostring(data));
 132                 session:close("not-well-formed");
 133         elseif error == "stream-error" then
 134                 local condition, text = "undefined-condition";
 135                 for child in data:children() do
 136                         if child.attr.xmlns == xmlns_xmpp_streams then
 137                                 if child.name ~= "text" then
 138                                         condition = child.name;
 139                                 else
 140                                         text = child:get_text();
 141                                 end
 142                                 if condition ~= "undefined-condition" and text then
 143                                         break;
 144                                 end
 145                         end
 146                 end
 147                 text = condition .. (text and (" ("..text..")") or "");
 148                 session.log("info", "Session closed by remote with error: %s", text);
 149                 session:close(nil, text);
 150         end
 151 end
 152
 153 function stream_callbacks.streamopened(session, attr)
 154         if not hosts[attr.to] or not hosts[attr.to].modules.component then
 155                 session:close{ condition = "host-unknown", text = tostring(attr.to).." does not match any configured external components" };
 156                 return;
 157         end
 158         session.host = attr.to;
 159         session.streamid = uuid_gen();
 160         session.notopen = nil;
 161         -- Return stream header
 162         session.send("<?xml version='1.0'?>");
 163         session.send(st.stanza("stream:stream", { xmlns=xmlns_component,
 164                         ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.host }):top_tag());
 165 end
 166
 167 function stream_callbacks.streamclosed(session)
 168         session.log("debug", "Received </stream:stream>");
 169         session:close();
 170 end
 171
 172 local core_process_stanza = core_process_stanza;
 173
 174 function stream_callbacks.handlestanza(session, stanza)
 175         -- Namespaces are icky.
 176         if not stanza.attr.xmlns and stanza.name == "handshake" then
 177                 stanza.attr.xmlns = xmlns_component;
 178         end
 179         if not stanza.attr.xmlns or stanza.attr.xmlns == "jabber:client" then
 180                 local from = stanza.attr.from;
 181                 if from then
 182                         if session.component_validate_from then
 183                                 local _, domain = jid_split(stanza.attr.from);
 184                                 if domain ~= session.host then
 185                                         -- Return error
 186                                         session.log("warn", "Component sent stanza with missing or invalid 'from' address");
 187                                         session:close{
 188                                                 condition = "invalid-from";
 189                                                 text = "Component tried to send from address <"..tostring(from)
 190                                                            .."> which is not in domain <"..tostring(session.host)..">";
 191                                         };
 192                                         return;
 193                                 end
 194                         end
 195                 else
 196                         stanza.attr.from = session.host; -- COMPAT: Strictly we shouldn't allow this
 197                 end
 198                 if not stanza.attr.to then
 199                         session.log("warn", "Rejecting stanza with no 'to' address");
 200                         session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST specify a 'to' address on stanzas"));
 201                         return;
 202                 end
 203         end
 204         return core_process_stanza(session, stanza);
 205 end
 206
 207 --- Closing a component connection
 208 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 209 local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };
 210 local function session_close(session, reason)
 211         if session.destroyed then return; end
 212         if session.conn then
 213                 if session.notopen then
 214                         session.send("<?xml version='1.0'?>");
 215                         session.send(st.stanza("stream:stream", default_stream_attr):top_tag());
 216                 end
 217                 if reason then
 218                         if type(reason) == "string" then -- assume stream error
 219                                 module:log("info", "Disconnecting component, <stream:error> is: %s", reason);
 220                                 session.send(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
 221                         elseif type(reason) == "table" then
 222                                 if reason.condition then
 223                                         local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
 224                                         if reason.text then
 225                                                 stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
 226                                         end
 227                                         if reason.extra then
 228                                                 stanza:add_child(reason.extra);
 229                                         end
 230                                         module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(stanza));
 231                                         session.send(stanza);
 232                                 elseif reason.name then -- a stanza
 233                                         module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(reason));
 234                                         session.send(reason);
 235                                 end
 236                         end
 237                 end
 238                 session.send("</stream:stream>");
 239                 session.conn:close();
 240                 listener.ondisconnect(session.conn, "stream error");
 241         end
 242 end
 243
 244 --- Component connlistener
 245
 246 function listener.onconnect(conn)
 247         local _send = conn.write;
 248         local session = { type = "component_unauthed", conn = conn, send = function (data) return _send(conn, tostring(data)); end };
 249
 250         -- Logging functions --
 251         local conn_name = "jcp"..tostring(conn):match("[a-f0-9]+$");
 252         session.log = logger.init(conn_name);
 253         session.close = session_close;
 254
 255         session.log("info", "Incoming Jabber component connection");
 256
 257         local stream = new_xmpp_stream(session, stream_callbacks);
 258         session.stream = stream;
 259
 260         session.notopen = true;
 261
 262         function session.reset_stream()
 263                 session.notopen = true;
 264                 session.stream:reset();
 265         end
 266
 267         function session.data(conn, data)
 268                 local ok, err = stream:feed(data);
 269                 if ok then return; end
 270                 module:log("debug", "Received invalid XML (%s) %d bytes: %s", tostring(err), #data, data:sub(1, 300):gsub("[\r\n]+", " "):gsub("[%z\1-\31]", "_"));
 271                 session:close("not-well-formed");
 272         end
 273
 274         session.dispatch_stanza = stream_callbacks.handlestanza;
 275
 276         sessions[conn] = session;
 277 end
 278 function listener.onincoming(conn, data)
 279         local session = sessions[conn];
 280         session.data(conn, data);
 281 end
 282 function listener.ondisconnect(conn, err)
 283         local session = sessions[conn];
 284         if session then
 285                 (session.log or log)("info", "component disconnected: %s (%s)", tostring(session.host), tostring(err));
 286                 if session.on_destroy then session:on_destroy(err); end
 287                 sessions[conn] = nil;
 288                 for k in pairs(session) do
 289                         if k ~= "log" and k ~= "close" then
 290                                 session[k] = nil;
 291                         end
 292                 end
 293                 session.destroyed = true;
 294                 session = nil;
 295         end
 296 end
 297
 298 module:add_item("net-provider", {
 299         name = "component";
 300         listener = listener;
 301         default_port = 5347;
 302         multiplex = {
 303                 pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:component%1.*>";
 304         };
 305 });