core/stanza_router.lua

   1
   2 -- The code in this file should be self-explanatory, though the logic is horrible
   3 -- for more info on that, see doc/stanza_routing.txt, which attempts to condense
   4 -- the rules from the RFCs (mainly 3921)
   5
   6 require "core.servermanager"
   7
   8 local log = require "util.logger".init("stanzarouter")
   9
  10 local st = require "util.stanza";
  11 local send_s2s = require "core.s2smanager".send_to_host;
  12 local user_exists = require "core.usermanager".user_exists;
  13
  14 local rostermanager = require "core.rostermanager";
  15 local sessionmanager = require "core.sessionmanager";
  16
  17 local s2s_verify_dialback = require "core.s2smanager".verify_dialback;
  18 local s2s_make_authenticated = require "core.s2smanager".make_authenticated;
  19 local format = string.format;
  20 local tostring = tostring;
  21
  22 local jid_split = require "util.jid".split;
  23 local print = print;
  24
  25 function core_process_stanza(origin, stanza)
  26         log("debug", "Received: "..tostring(stanza))
  27         -- TODO verify validity of stanza (as well as JID validity)
  28         if stanza.name == "iq" and not(#stanza.tags == 1 and stanza.tags[1].attr.xmlns) then
  29                 if stanza.attr.type == "set" or stanza.attr.type == "get" then
  30                         error("Invalid IQ");
  31                 elseif #stanza.tags > 1 and not(stanza.attr.type == "error" or stanza.attr.type == "result") then
  32                         error("Invalid IQ");
  33                 end
  34         end
  35
  36         if origin.type == "c2s" and not origin.full_jid
  37                 and not(stanza.name == "iq" and stanza.tags[1].name == "bind"
  38                                 and stanza.tags[1].attr.xmlns == "urn:ietf:params:xml:ns:xmpp-bind") then
  39                 error("Client MUST bind resource after auth");
  40         end
  41
  42         local to = stanza.attr.to;
  43         -- TODO also, stazas should be returned to their original state before the function ends
  44         if origin.type == "c2s" then
  45                 stanza.attr.from = origin.full_jid; -- quick fix to prevent impersonation (FIXME this would be incorrect when the origin is not c2s)
  46         end
  47
  48         if not to then
  49                 core_handle_stanza(origin, stanza);
  50         elseif origin.type == "c2s" and stanza.name == "presence" and stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then
  51                 local node, host = jid_split(stanza.attr.to);
  52                 local to_bare = node and (node.."@"..host) or host; -- bare JID
  53                 local from_node, from_host = jid_split(stanza.attr.from);
  54                 local from_bare = from_node and (from_node.."@"..from_host) or from_host; -- bare JID
  55                 handle_outbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare);
  56         elseif hosts[to] and hosts[to].type == "local" then
  57                 core_handle_stanza(origin, stanza);
  58         elseif stanza.name == "iq" and not select(3, jid_split(to)) then
  59                 core_handle_stanza(origin, stanza);
  60         elseif origin.type == "c2s" or origin.type == "s2sin" then
  61                 core_route_stanza(origin, stanza);
  62         end
  63 end
  64
  65 -- This function handles stanzas which are not routed any further,
  66 -- that is, they are handled by this server
  67 function core_handle_stanza(origin, stanza)
  68         -- Handlers
  69         if origin.type == "c2s" or origin.type == "c2s_unauthed" then
  70                 local session = origin;
  71
  72                 if stanza.name == "presence" and origin.roster then
  73                         if stanza.attr.type == nil or stanza.attr.type == "unavailable" then
  74                                 for jid in pairs(origin.roster) do -- broadcast to all interested contacts
  75                                         local subscription = origin.roster[jid].subscription;
  76                                         if subscription == "both" or subscription == "from" then
  77                                                 stanza.attr.to = jid;
  78                                                 core_route_stanza(origin, stanza);
  79                                         end
  80                                 end
  81                                 local node, host = jid_split(stanza.attr.from);
  82                                 for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast to all resources
  83                                         if res ~= origin and res.full_jid then -- to resource. FIXME is res.full_jid the correct check? Maybe it should be res.presence
  84                                                 stanza.attr.to = res.full_jid;
  85                                                 core_route_stanza(origin, stanza);
  86                                         end
  87                                 end
  88                                 if not origin.presence then -- presence probes on initial presence -- FIXME does unavailable qualify as initial presence?
  89                                         local probe = st.presence({from = origin.full_jid, type = "probe"});
  90                                         for jid in pairs(origin.roster) do -- probe all contacts we are subscribed to
  91                                                 local subscription = origin.roster[jid].subscription;
  92                                                 if subscription == "both" or subscription == "to" then
  93                                                         probe.attr.to = jid;
  94                                                         core_route_stanza(origin, probe);
  95                                                 end
  96                                         end
  97                                         for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast from all resources
  98                                                 if res ~= origin and stanza.attr.type ~= "unavailable" and res.presence then -- FIXME does unavailable qualify as initial presence?
  99                                                         res.presence.attr.to = origin.full_jid;
 100                                                         core_route_stanza(res, res.presence);
 101                                                         res.presence.attr.to = nil;
 102                                                 end
 103                                         end
 104                                         -- TODO resend subscription requests
 105                                 end
 106                                 origin.presence = stanza;
 107                                 stanza.attr.to = nil; -- reset it
 108                         else
 109                                 -- TODO error, bad type
 110                         end
 111                 else
 112                         log("debug", "Routing stanza to local");
 113                         handle_stanza(session, stanza);
 114                 end
 115         elseif origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
 116                 if stanza.attr.xmlns == "jabber:server:dialback" then
 117                         if stanza.name == "verify" then
 118                                 -- We are being asked to verify the key, to ensure it was generated by us
 119                                 log("debug", "verifying dialback key...");
 120                                 local attr = stanza.attr;
 121                                 print(tostring(attr.to), tostring(attr.from))
 122                                 print(tostring(origin.to_host), tostring(origin.from_host))
 123                                 -- FIXME: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
 124                                 --if attr.from ~= origin.to_host then error("invalid-from"); end
 125                                 local type;
 126                                 if s2s_verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
 127                                         type = "valid"
 128                                 else
 129                                         type = "invalid"
 130                                         log("warn", "Asked to verify a dialback key that was incorrect. An imposter is claiming to be %s?", attr.to);
 131                                 end
 132                                 origin.sends2s(format("<db:verify from='%s' to='%s' id='%s' type='%s'>%s</db:verify>", attr.to, attr.from, attr.id, type, stanza[1]));
 133                         elseif stanza.name == "result" and origin.type == "s2sin_unauthed" then
 134                                 -- he wants to be identified through dialback
 135                                 -- We need to check the key with the Authoritative server
 136                                 local attr = stanza.attr;
 137                                 origin.from_host = attr.from;
 138                                 origin.to_host = attr.to;
 139                                 origin.dialback_key = stanza[1];
 140                                 log("debug", "asking %s if key %s belongs to them", attr.from, stanza[1]);
 141                                 send_s2s(attr.to, attr.from, format("<db:verify from='%s' to='%s' id='%s'>%s</db:verify>", attr.to, attr.from, origin.streamid, stanza[1]));
 142                                 hosts[attr.from].dialback_verifying = origin;
 143                         end
 144                 end
 145         elseif origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
 146                 if stanza.attr.xmlns == "jabber:server:dialback" then
 147                         if stanza.name == "result" then
 148                                 if stanza.attr.type == "valid" then
 149                                         s2s_make_authenticated(origin);
 150                                 else
 151                                         -- FIXME
 152                                         error("dialback failed!");
 153                                 end
 154                         elseif stanza.name == "verify" and origin.dialback_verifying then
 155                                 local valid;
 156                                 local attr = stanza.attr;
 157                                 if attr.type == "valid" then
 158                                         s2s_make_authenticated(origin.dialback_verifying);
 159                                         valid = "valid";
 160                                 else
 161                                         -- Warn the original connection that is was not verified successfully
 162                                         log("warn", "dialback for "..(origin.dialback_verifying.from_host or "(unknown)").." failed");
 163                                         valid = "invalid";
 164                                 end
 165                                 origin.dialback_verifying.sends2s(format("<db:result from='%s' to='%s' id='%s' type='%s'>%s</db:result>", attr.from, attr.to, attr.id, valid, origin.dialback_verifying.dialback_key));
 166                         end
 167                 end
 168         else
 169                 log("warn", "Unhandled origin: %s", origin.type);
 170         end
 171 end
 172
 173 function send_presence_of_available_resources(user, host, jid, recipient_session)
 174         local h = hosts[host];
 175         local count = 0;
 176         if h and h.type == "local" then
 177                 local u = h.sessions[user];
 178                 if u then
 179                         for k, session in pairs(u.sessions) do
 180                                 local pres = session.presence;
 181                                 if pres then
 182                                         pres.attr.to = jid;
 183                                         pres.attr.from = session.full_jid;
 184                                         recipient_session.send(pres);
 185                                         pres.attr.to = nil;
 186                                         pres.attr.from = nil;
 187                                         count = count + 1;
 188                                 end
 189                         end
 190                 end
 191         end
 192         return count;
 193 end
 194
 195 function handle_outbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare)
 196         local node, host = jid_split(from_bare);
 197         local st_from, st_to = stanza.attr.from, stanza.attr.to;
 198         stanza.attr.from, stanza.attr.to = from_bare, to_bare;
 199         if stanza.attr.type == "subscribe" then
 200                 log("debug", "outbound subscribe from "..from_bare.." for "..to_bare);
 201                 -- 1. route stanza
 202                 -- 2. roster push (subscription = none, ask = subscribe)
 203                 if rostermanager.set_contact_pending_out(node, host, to_bare) then
 204                         rostermanager.roster_push(node, host, to_bare);
 205                 end -- else file error
 206                 core_route_stanza(origin, stanza);
 207         elseif stanza.attr.type == "unsubscribe" then
 208                 log("debug", "outbound unsubscribe from "..from_bare.." for "..to_bare);
 209                 -- 1. route stanza
 210                 -- 2. roster push (subscription = none or from)
 211                 if rostermanager.unsubscribe(node, host, to_bare) then
 212                         rostermanager.roster_push(node, host, to_bare); -- FIXME do roster push when roster has in fact not changed?
 213                 end -- else file error
 214                 core_route_stanza(origin, stanza);
 215         elseif stanza.attr.type == "subscribed" then
 216                 log("debug", "outbound subscribed from "..from_bare.." for "..to_bare);
 217                 -- 1. route stanza
 218                 -- 2. roster_push ()
 219                 -- 3. send_presence_of_available_resources
 220                 if rostermanager.subscribed(node, host, to_bare) then
 221                         rostermanager.roster_push(node, host, to_bare);
 222                         core_route_stanza(origin, stanza);
 223                         send_presence_of_available_resources(node, host, to_bare, origin);
 224                 end
 225         elseif stanza.attr.type == "unsubscribed" then
 226                 log("debug", "outbound unsubscribed from "..from_bare.." for "..to_bare);
 227                 -- 1. route stanza
 228                 -- 2. roster push (subscription = none or to)
 229                 if rostermanager.unsubscribed(node, host, to_bare) then
 230                         rostermanager.roster_push(node, host, to_bare);
 231                         core_route_stanza(origin, stanza);
 232                 end
 233         end
 234         stanza.attr.from, stanza.attr.to = st_from, st_to;
 235 end
 236
 237 function handle_inbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare)
 238         local node, host = jid_split(to_bare);
 239         local st_from, st_to = stanza.attr.from, stanza.attr.to;
 240         stanza.attr.from, stanza.attr.to = from_bare, to_bare;
 241         if stanza.attr.type == "probe" then
 242                 if rostermanager.is_contact_subscribed(node, host, from_bare) then
 243                         if 0 == send_presence_of_available_resources(node, host, from_bare, origin) then
 244                                 -- TODO send last recieved unavailable presence (or we MAY do nothing, which is fine too)
 245                         end
 246                 else
 247                         core_route_stanza(origin, st.presence({from=to_bare, to=from_bare, type="unsubscribed"}));
 248                 end
 249         elseif stanza.attr.type == "subscribe" then
 250                 log("debug", "inbound subscribe from "..from_bare.." for "..to_bare);
 251                 if rostermanager.is_contact_subscribed(node, host, from_bare) then
 252                         core_route_stanza(origin, st.presence({from=to_bare, to=from_bare, type="subscribed"})); -- already subscribed
 253                 else
 254                         if not rostermanager.is_contact_pending_in(node, host, from_bare) then
 255                                 if rostermanager.set_contact_pending_in(node, host, from_bare) then
 256                                         sessionmanager.send_to_available_resources(node, host, stanza);
 257                                 end -- TODO else return error, unable to save
 258                         end
 259                 end
 260         elseif stanza.attr.type == "unsubscribe" then
 261                 log("debug", "inbound unsubscribe from "..from_bare.." for "..to_bare);
 262                 if rostermanager.process_inbound_unsubscribe(node, host, from_bare) then
 263                         rostermanager.roster_push(node, host, from_bare);
 264                 end
 265         elseif stanza.attr.type == "subscribed" then
 266                 log("debug", "inbound subscribed from "..from_bare.." for "..to_bare);
 267                 if rostermanager.process_inbound_subscription_approval(node, host, from_bare) then
 268                         rostermanager.roster_push(node, host, from_bare);
 269                 end
 270         elseif stanza.attr.type == "unsubscribed" then
 271                 log("debug", "inbound unsubscribed from "..from_bare.." for "..to_bare);
 272                 if rostermanager.process_inbound_subscription_approval(node, host, from_bare) then
 273                         rostermanager.roster_push(node, host, from_bare);
 274                 end
 275         end -- discard any other type
 276         stanza.attr.from, stanza.attr.to = st_from, st_to;
 277 end
 278
 279 function core_route_stanza(origin, stanza)
 280         -- Hooks
 281         --- ...later
 282
 283         -- Deliver
 284         local to = stanza.attr.to;
 285         local node, host, resource = jid_split(to);
 286         local to_bare = node and (node.."@"..host) or host; -- bare JID
 287         local from = stanza.attr.from;
 288         local from_node, from_host, from_resource = jid_split(from);
 289         local from_bare = from_node and (from_node.."@"..from_host) or from_host; -- bare JID
 290
 291         if stanza.name == "presence" and (stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable") then resource = nil; end
 292
 293         local host_session = hosts[host]
 294         if host_session and host_session.type == "local" then
 295                 -- Local host
 296                 local user = host_session.sessions[node];
 297                 if user then
 298                         local res = user.sessions[resource];
 299                         if not res then
 300                                 -- if we get here, resource was not specified or was unavailable
 301                                 if stanza.name == "presence" then
 302                                         if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then
 303                                                 handle_inbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare);
 304                                         else -- sender is available or unavailable
 305                                                 for k in pairs(user.sessions) do -- presence broadcast to all user resources. FIXME should this be just for available resources? Do we need to check subscription?
 306                                                         if user.sessions[k].full_jid then
 307                                                                 stanza.attr.to = user.sessions[k].full_jid; -- reset at the end of function
 308                                                                 user.sessions[k].send(stanza);
 309                                                         end
 310                                                 end
 311                                         end
 312                                 elseif stanza.name == "message" then -- select a resource to recieve message
 313                                         for k in pairs(user.sessions) do
 314                                                 if user.sessions[k].full_jid then
 315                                                         res = user.sessions[k];
 316                                                         break;
 317                                                 end
 318                                         end
 319                                         -- TODO find resource with greatest priority
 320                                         res.send(stanza);
 321                                 else
 322                                         -- TODO send IQ error
 323                                 end
 324                         else
 325                                 -- User + resource is online...
 326                                 stanza.attr.to = res.full_jid; -- reset at the end of function
 327                                 res.send(stanza); -- Yay \o/
 328                         end
 329                 else
 330                         -- user not online
 331                         if user_exists(node, host) then
 332                                 if stanza.name == "presence" then
 333                                         if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then
 334                                                 handle_inbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare);
 335                                         else
 336                                                 -- TODO send unavailable presence or unsubscribed
 337                                         end
 338                                 elseif stanza.name == "message" then
 339                                         -- TODO send message error, or store offline messages
 340                                 elseif stanza.name == "iq" then
 341                                         -- TODO send IQ error
 342                                 end
 343                         else -- user does not exist
 344                                 -- TODO we would get here for nodeless JIDs too. Do something fun maybe? Echo service? Let plugins use xmpp:server/resource addresses?
 345                                 if stanza.name == "presence" then
 346                                         if stanza.attr.type == "probe" then
 347                                                 origin.send(st.presence({from = to_bare, to = from_bare, type = "unsubscribed"}));
 348                                         end
 349                                         -- else ignore
 350                                 else
 351                                         origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
 352                                 end
 353                         end
 354                 end
 355         elseif origin.type == "c2s" then
 356                 -- Remote host
 357                 local xmlns = stanza.attr.xmlns;
 358                 --stanza.attr.xmlns = "jabber:server";
 359                 stanza.attr.xmlns = nil;
 360                 log("debug", "sending s2s stanza: %s", tostring(stanza));
 361                 send_s2s(origin.host, host, stanza); -- TODO handle remote routing errors
 362                 stanza.attr.xmlns = xmlns; -- reset
 363         else
 364                 log("warn", "received stanza from unhandled connection type: %s", origin.type);
 365         end
 366         stanza.attr.to = to; -- reset
 367 end
 368
 369 function handle_stanza_toremote(stanza)
 370         log("error", "Stanza bound for remote host, but s2s is not implemented");
 371 end