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 local xpcall, tostring, type = xpcall, tostring, type;
  13 local traceback = debug.traceback;
  14
  15 local logger = require "util.logger";
  16 local sha1 = require "util.hashes".sha1;
  17 local st = require "util.stanza";
  18
  19 local jid_split = require "util.jid".split;
  20 local new_xmpp_stream = require "util.xmppstream".new;
  21 local uuid_gen = require "util.uuid".generate;
  22
  23 local core_process_stanza = prosody.core_process_stanza;
  24 local hosts = prosody.hosts;
  25
  26 local log = module._log;
  27
  28 local opt_keepalives = module:get_option_boolean("component_tcp_keepalives", module:get_option_boolean("tcp_keepalives", true));
  29
  30 local sessions = module:shared("sessions");
  31
  32 function module.add_host(module)
  33         if module:get_host_type() ~= "component" then
  34                 error("Don't load mod_component manually, it should be for a component, please see https://prosody.im/doc/components", 0);
  35         end
  36
  37         local env = module.environment;
  38         env.connected = false;
  39         env.session = false;
  40
  41         local send;
  42
  43         local function on_destroy(session, err) --luacheck: ignore 212/err
  44                 env.connected = false;
  45                 env.session = false;
  46                 send = nil;
  47                 session.on_destroy = nil;
  48         end
  49
  50         -- Handle authentication attempts by component
  51         local function handle_component_auth(event)
  52                 local session, stanza = event.origin, event.stanza;
  53
  54                 if session.type ~= "component_unauthed" then return; end
  55
  56                 if (not session.host) or #stanza.tags > 0 then
  57                         (session.log or log)("warn", "Invalid component handshake for host: %s", session.host);
  58                         session:close("not-authorized");
  59                         return true;
  60                 end
  61
  62                 local secret = module:get_option("component_secret");
  63                 if not secret then
  64                         (session.log or log)("warn", "Component attempted to identify as %s, but component_secret is not set", session.host);
  65                         session:close("not-authorized");
  66                         return true;
  67                 end
  68
  69                 local supplied_token = t_concat(stanza);
  70                 local calculated_token = sha1(session.streamid..secret, true);
  71                 if supplied_token:lower() ~= calculated_token:lower() then
  72                         module:log("info", "Component authentication failed for %s", session.host);
  73                         session:close{ condition = "not-authorized", text = "Given token does not match calculated token" };
  74                         return true;
  75                 end
  76
  77                 if env.connected then
  78                         local policy = module:get_option_string("component_conflict_resolve", "kick_new");
  79                         if policy == "kick_old" then
  80                                 env.session:close{ condition = "conflict", text = "Replaced by a new connection" };
  81                         else -- kick_new
  82                                 module:log("error", "Second component attempted to connect, denying connection");
  83                                 session:close{ condition = "conflict", text = "Component already connected" };
  84                                 return true;
  85                         end
  86                 end
  87
  88                 env.connected = true;
  89                 env.session = session;
  90                 send = session.send;
  91                 session.on_destroy = on_destroy;
  92                 session.component_validate_from = module:get_option_boolean("validate_from_addresses", true);
  93                 session.type = "component";
  94                 module:log("info", "External component successfully authenticated");
  95                 session.send(st.stanza("handshake"));
  96                 module:fire_event("component-authenticated", { session = session });
  97
  98                 return true;
  99         end
 100         module:hook("stanza/jabber:component:accept:handshake", handle_component_auth, -1);
 101
 102         -- Handle stanzas addressed to this component
 103         local function handle_stanza(event)
 104                 local stanza = event.stanza;
 105                 if send then
 106                         stanza.attr.xmlns = nil;
 107                         send(stanza);
 108                 else
 109                         if stanza.name == "iq" and stanza.attr.type == "get" and stanza.attr.to == module.host then
 110                                 local query = stanza.tags[1];
 111                                 local node = query.attr.node;
 112                                 if query.name == "query" and query.attr.xmlns == "http://jabber.org/protocol/disco#info" and (not node or node == "") then
 113                                         local name = module:get_option_string("name");
 114                                         if name then
 115                                                 event.origin.send(st.reply(stanza):tag("query", { xmlns = "http://jabber.org/protocol/disco#info" })
 116                                                         :tag("identity", { category = "component", type = "generic", name = module:get_option_string("name", "Prosody") }))
 117                                                 return true;
 118                                         end
 119                                 end
 120                         end
 121                         module:log("warn", "Component not connected, bouncing error for: %s", stanza:top_tag());
 122                         if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then
 123                                 event.origin.send(st.error_reply(stanza, "wait", "service-unavailable", "Component unavailable"));
 124                         end
 125                 end
 126                 return true;
 127         end
 128
 129         module:hook("iq/bare", handle_stanza, -1);
 130         module:hook("message/bare", handle_stanza, -1);
 131         module:hook("presence/bare", handle_stanza, -1);
 132         module:hook("iq/full", handle_stanza, -1);
 133         module:hook("message/full", handle_stanza, -1);
 134         module:hook("presence/full", handle_stanza, -1);
 135         module:hook("iq/host", handle_stanza, -1);
 136         module:hook("message/host", handle_stanza, -1);
 137         module:hook("presence/host", handle_stanza, -1);
 138 end
 139
 140 --- Network and stream part ---
 141
 142 local xmlns_component = 'jabber:component:accept';
 143
 144 local listener = {};
 145
 146 --- Callbacks/data for xmppstream to handle streams for us ---
 147
 148 local stream_callbacks = { default_ns = xmlns_component };
 149
 150 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
 151
 152 function stream_callbacks.error(session, error, data)
 153         if session.destroyed then return; end
 154         module:log("warn", "Error processing component stream: %s", tostring(error));
 155         if error == "no-stream" then
 156                 session:close("invalid-namespace");
 157         elseif error == "parse-error" then
 158                 session.log("warn", "External component %s XML parse error: %s", tostring(session.host), tostring(data));
 159                 session:close("not-well-formed");
 160         elseif error == "stream-error" then
 161                 local condition, text = "undefined-condition";
 162                 for child in data:children() do
 163                         if child.attr.xmlns == xmlns_xmpp_streams then
 164                                 if child.name ~= "text" then
 165                                         condition = child.name;
 166                                 else
 167                                         text = child:get_text();
 168                                 end
 169                                 if condition ~= "undefined-condition" and text then
 170                                         break;
 171                                 end
 172                         end
 173                 end
 174                 text = condition .. (text and (" ("..text..")") or "");
 175                 session.log("info", "Session closed by remote with error: %s", text);
 176                 session:close(nil, text);
 177         end
 178 end
 179
 180 function stream_callbacks.streamopened(session, attr)
 181         if not hosts[attr.to] or not hosts[attr.to].modules.component then
 182                 session:close{ condition = "host-unknown", text = tostring(attr.to).." does not match any configured external components" };
 183                 return;
 184         end
 185         session.host = attr.to;
 186         session.streamid = uuid_gen();
 187         session.notopen = nil;
 188         -- Return stream header
 189         session:open_stream();
 190 end
 191
 192 function stream_callbacks.streamclosed(session)
 193         session.log("debug", "Received </stream:stream>");
 194         session:close();
 195 end
 196
 197 local function handleerr(err) log("error", "Traceback[component]: %s", traceback(tostring(err), 2)); end
 198 function stream_callbacks.handlestanza(session, stanza)
 199         -- Namespaces are icky.
 200         if not stanza.attr.xmlns and stanza.name == "handshake" then
 201                 stanza.attr.xmlns = xmlns_component;
 202         end
 203         if not stanza.attr.xmlns or stanza.attr.xmlns == "jabber:client" then
 204                 local from = stanza.attr.from;
 205                 if from then
 206                         if session.component_validate_from then
 207                                 local _, domain = jid_split(stanza.attr.from);
 208                                 if domain ~= session.host then
 209                                         -- Return error
 210                                         session.log("warn", "Component sent stanza with missing or invalid 'from' address");
 211                                         session:close{
 212                                                 condition = "invalid-from";
 213                                                 text = "Component tried to send from address <"..tostring(from)
 214                                                            .."> which is not in domain <"..tostring(session.host)..">";
 215                                         };
 216                                         return;
 217                                 end
 218                         end
 219                 else
 220                         stanza.attr.from = session.host; -- COMPAT: Strictly we shouldn't allow this
 221                 end
 222                 if not stanza.attr.to then
 223                         session.log("warn", "Rejecting stanza with no 'to' address");
 224                         session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST specify a 'to' address on stanzas"));
 225                         return;
 226                 end
 227         end
 228
 229         if stanza then
 230                 return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);
 231         end
 232 end
 233
 234 --- Closing a component connection
 235 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 236 local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };
 237 local function session_close(session, reason)
 238         if session.destroyed then return; end
 239         if session.conn then
 240                 if session.notopen then
 241                         session.send("<?xml version='1.0'?>");
 242                         session.send(st.stanza("stream:stream", default_stream_attr):top_tag());
 243                 end
 244                 if reason then
 245                         if type(reason) == "string" then -- assume stream error
 246                                 module:log("info", "Disconnecting component, <stream:error> is: %s", reason);
 247                                 session.send(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
 248                         elseif type(reason) == "table" then
 249                                 if reason.condition then
 250                                         local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
 251                                         if reason.text then
 252                                                 stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
 253                                         end
 254                                         if reason.extra then
 255                                                 stanza:add_child(reason.extra);
 256                                         end
 257                                         module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(stanza));
 258                                         session.send(stanza);
 259                                 elseif reason.name then -- a stanza
 260                                         module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(reason));
 261                                         session.send(reason);
 262                                 end
 263                         end
 264                 end
 265                 session.send("</stream:stream>");
 266                 session.conn:close();
 267                 listener.ondisconnect(session.conn, "stream error");
 268         end
 269 end
 270
 271 --- Component connlistener
 272
 273 function listener.onconnect(conn)
 274         local _send = conn.write;
 275         local session = { type = "component_unauthed", conn = conn, send = function (data) return _send(conn, tostring(data)); end };
 276
 277         -- Logging functions --
 278         local conn_name = "jcp"..tostring(session):match("[a-f0-9]+$");
 279         session.log = logger.init(conn_name);
 280         session.close = session_close;
 281
 282         if opt_keepalives then
 283                 conn:setoption("keepalive", opt_keepalives);
 284         end
 285
 286         session.log("info", "Incoming Jabber component connection");
 287
 288         local stream = new_xmpp_stream(session, stream_callbacks);
 289         session.stream = stream;
 290
 291         session.notopen = true;
 292
 293         function session.reset_stream()
 294                 session.notopen = true;
 295                 session.stream:reset();
 296         end
 297
 298         function session.data(_, data)
 299                 local ok, err = stream:feed(data);
 300                 if ok then return; end
 301                 module:log("debug", "Received invalid XML (%s) %d bytes: %s", tostring(err), #data, data:sub(1, 300):gsub("[\r\n]+", " "):gsub("[%z\1-\31]", "_"));
 302                 session:close("not-well-formed");
 303         end
 304
 305         session.dispatch_stanza = stream_callbacks.handlestanza;
 306
 307         sessions[conn] = session;
 308 end
 309 function listener.onincoming(conn, data)
 310         local session = sessions[conn];
 311         session.data(conn, data);
 312 end
 313 function listener.ondisconnect(conn, err)
 314         local session = sessions[conn];
 315         if session then
 316                 (session.log or log)("info", "component disconnected: %s (%s)", tostring(session.host), tostring(err));
 317                 module:fire_event("component-disconnected", { session = session, reason = err });
 318                 if session.on_destroy then session:on_destroy(err); end
 319                 sessions[conn] = nil;
 320                 for k in pairs(session) do
 321                         if k ~= "log" and k ~= "close" then
 322                                 session[k] = nil;
 323                         end
 324                 end
 325                 session.destroyed = true;
 326         end
 327 end
 328
 329 function listener.ondetach(conn)
 330         sessions[conn] = nil;
 331 end
 332
 333 module:provides("net", {
 334         name = "component";
 335         private = true;
 336         listener = listener;
 337         default_port = 5347;
 338         multiplex = {
 339                 pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:component:accept%1.*>";
 340         };
 341 });