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 = require "core.sessionmanager".send_to_session;
  12 local send_s2s = require "core.s2smanager".send_to_host;
  13 local user_exists = require "core.usermanager".user_exists;
  14
  15 local rostermanager = require "core.rostermanager";
  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 hosts[to] and hosts[to].type == "local" then
  51                 core_handle_stanza(origin, stanza);
  52         elseif stanza.name == "iq" and not select(3, jid_split(to)) then
  53                 core_handle_stanza(origin, stanza);
  54         elseif origin.type == "c2s" or origin.type == "s2sin" then
  55                 core_route_stanza(origin, stanza);
  56         end
  57 end
  58
  59 -- This function handles stanzas which are not routed any further,
  60 -- that is, they are handled by this server
  61 function core_handle_stanza(origin, stanza)
  62         -- Handlers
  63         if origin.type == "c2s" or origin.type == "c2s_unauthed" then
  64                 local session = origin;
  65
  66                 if stanza.name == "presence" and origin.roster then
  67                         if stanza.attr.type == nil or stanza.attr.type == "unavailable" then
  68                                 for jid in pairs(origin.roster) do -- broadcast to all interested contacts
  69                                         local subscription = origin.roster[jid].subscription;
  70                                         if subscription == "both" or subscription == "from" then
  71                                                 stanza.attr.to = jid;
  72                                                 core_route_stanza(origin, stanza);
  73                                         end
  74                                 end
  75                                 local node, host = jid_split(stanza.attr.from);
  76                                 for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast to all resources
  77                                         if res ~= origin and res.full_jid then -- to resource. FIXME is res.full_jid the correct check? Maybe it should be res.presence
  78                                                 stanza.attr.to = res.full_jid;
  79                                                 core_route_stanza(origin, stanza);
  80                                         end
  81                                 end
  82                                 if not origin.presence then -- presence probes on initial presence
  83                                         local probe = st.presence({from = origin.full_jid, type = "probe"});
  84                                         for jid in pairs(origin.roster) do -- probe all contacts we are subscribed to
  85                                                 local subscription = origin.roster[jid].subscription;
  86                                                 if subscription == "both" or subscription == "to" then
  87                                                         probe.attr.to = jid;
  88                                                         core_route_stanza(origin, probe);
  89                                                 end
  90                                         end
  91                                         for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast from all resources
  92                                                 if res ~= origin and stanza.attr.type ~= "unavailable" and res.presence then -- FIXME does unavailable qualify as initial presence?
  93                                                         res.presence.attr.to = origin.full_jid;
  94                                                         core_route_stanza(res, res.presence);
  95                                                         res.presence.attr.to = nil;
  96                                                 end
  97                                         end
  98                                         -- TODO resend subscription requests
  99                                 end
 100                                 origin.presence = stanza;
 101                                 stanza.attr.to = nil; -- reset it
 102                         else
 103                                 -- TODO error, bad type
 104                         end
 105                 else
 106                         log("debug", "Routing stanza to local");
 107                         handle_stanza(session, stanza);
 108                 end
 109         elseif origin.type == "s2sin_unauthed" or origin.type == "s2sin" then
 110                 if stanza.attr.xmlns == "jabber:server:dialback" then
 111                         if stanza.name == "verify" then
 112                                 -- We are being asked to verify the key, to ensure it was generated by us
 113                                 log("debug", "verifying dialback key...");
 114                                 local attr = stanza.attr;
 115                                 print(tostring(attr.to), tostring(attr.from))
 116                                 print(tostring(origin.to_host), tostring(origin.from_host))
 117                                 -- FIXME: Grr, ejabberd breaks this one too?? it is black and white in XEP-220 example 34
 118                                 --if attr.from ~= origin.to_host then error("invalid-from"); end
 119                                 local type = "invalid";
 120                                 if s2s_verify_dialback(attr.id, attr.from, attr.to, stanza[1]) then
 121                                         type = "valid"
 122                                 end
 123                                 origin.send(format("<db:verify from='%s' to='%s' id='%s' type='%s'>%s</db:verify>", attr.to, attr.from, attr.id, type, stanza[1]));
 124                         elseif stanza.name == "result" and origin.type == "s2sin_unauthed" then
 125                                 -- he wants to be identified through dialback
 126                                 -- We need to check the key with the Authoritative server
 127                                 local attr = stanza.attr;
 128                                 origin.from_host = attr.from;
 129                                 origin.to_host = attr.to;
 130                                 origin.dialback_key = stanza[1];
 131                                 log("debug", "asking %s if key %s belongs to them", attr.from, stanza[1]);
 132                                 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]));
 133                                 hosts[attr.from].dialback_verifying = origin;
 134                         end
 135                 end
 136         elseif origin.type == "s2sout_unauthed" or origin.type == "s2sout" then
 137                 if stanza.attr.xmlns == "jabber:server:dialback" then
 138                         if stanza.name == "result" then
 139                                 if stanza.attr.type == "valid" then
 140                                         s2s_make_authenticated(origin);
 141                                 else
 142                                         -- FIXME
 143                                         error("dialback failed!");
 144                                 end
 145                         elseif stanza.name == "verify" and origin.dialback_verifying then
 146                                 local valid;
 147                                 local attr = stanza.attr;
 148                                 if attr.type == "valid" then
 149                                         s2s_make_authenticated(origin.dialback_verifying);
 150                                         valid = "valid";
 151                                 else
 152                                         -- Warn the original connection that is was not verified successfully
 153                                         log("warn", "dialback for "..(origin.dialback_verifying.from_host or "(unknown)").." failed");
 154                                         valid = "invalid";
 155                                 end
 156                                 origin.dialback_verifying.send(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));
 157                         end
 158                 end
 159         else
 160                 log("warn", "Unhandled origin: %s", origin.type);
 161         end
 162 end
 163
 164 function is_authorized_to_see_presence(origin, username, host)
 165         local roster = datamanager.load(username, host, "roster") or {};
 166         local item = roster[origin.username.."@"..origin.host];
 167         return item and (item.subscription == "both" or item.subscription == "from");
 168 end
 169
 170 function core_route_stanza(origin, stanza)
 171         -- Hooks
 172         --- ...later
 173
 174         -- Deliver
 175         local to = stanza.attr.to;
 176         local node, host, resource = jid_split(to);
 177         local to_bare = node and (node.."@"..host) or host; -- bare JID
 178         local from = stanza.attr.from;
 179         local from_node, from_host, from_resource = jid_split(from);
 180         local from_bare = from_node and (from_node.."@"..from_host) or from_host; -- bare JID
 181
 182         if stanza.name == "presence" and (stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable") then resource = nil; end
 183
 184         local host_session = hosts[host]
 185         if host_session and host_session.type == "local" then
 186                 -- Local host
 187                 local user = host_session.sessions[node];
 188                 if user then
 189                         local res = user.sessions[resource];
 190                         if not res then
 191                                 -- if we get here, resource was not specified or was unavailable
 192                                 if stanza.name == "presence" then
 193                                         if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then
 194                                                 if stanza.attr.type == "probe" then
 195                                                         if is_authorized_to_see_presence(origin, node, host) then
 196                                                                 for k in pairs(user.sessions) do -- return presence for all resources
 197                                                                         local pres = user.sessions[k].presence;
 198                                                                         if pres then
 199                                                                                 pres.attr.to = from; -- FIXME use from_bare or from?
 200                                                                                 pres.attr.from = user.sessions[k].full_jid;
 201                                                                                 send(origin, pres);
 202                                                                         end
 203                                                                 end
 204                                                                 pres.attr.to = nil;
 205                                                                 pres.attr.from = nil;
 206                                                         else
 207                                                                 send(origin, st.presence({from=to_bare, to=from_bare, type="unsubscribed"}));
 208                                                         end
 209                                                 elseif stanza.attr.type == "subscribe" then
 210                                                         -- TODO
 211                                                 elseif stanza.attr.type == "unsubscribe" then
 212                                                         -- TODO
 213                                                 elseif stanza.attr.type == "subscribed" then
 214                                                         if rostermanager.process_inbound_subscription_approval(node, host, from_bare) then
 215                                                                 rostermanager.roster_push(node, host, from_bare);
 216                                                                 for k in pairs(user.sessions) do -- return presence for all resources
 217                                                                         local pres = user.sessions[k].presence;
 218                                                                         if pres then
 219                                                                                 pres.attr.to = from; -- FIXME use from_bare or from?
 220                                                                                 pres.attr.from = user.sessions[k].full_jid;
 221                                                                                 send(origin, pres);
 222                                                                         end
 223                                                                 end
 224                                                                 pres.attr.to = nil;
 225                                                                 pres.attr.from = nil;
 226                                                         end
 227                                                 elseif stanza.attr.type == "unsubscribed" then
 228                                                         if rostermanager.process_inbound_subscription_approval(node, host, from_bare) then
 229                                                                 rostermanager.roster_push(node, host, from_bare);
 230                                                         end
 231                                                 end -- discard any other type
 232                                         else -- sender is available or unavailable
 233                                                 for k in pairs(user.sessions) do -- presence broadcast to all user resources
 234                                                         if user.sessions[k].full_jid then
 235                                                                 stanza.attr.to = user.sessions[k].full_jid; -- reset at the end of function
 236                                                                 send(user.sessions[k], stanza);
 237                                                         end
 238                                                 end
 239                                         end
 240                                 elseif stanza.name == "message" then -- select a resource to recieve message
 241                                         for k in pairs(user.sessions) do
 242                                                 if user.sessions[k].full_jid then
 243                                                         res = user.sessions[k];
 244                                                         break;
 245                                                 end
 246                                         end
 247                                         -- TODO find resource with greatest priority
 248                                         send(res, stanza);
 249                                 else
 250                                         -- TODO send IQ error
 251                                 end
 252                         else
 253                                 -- User + resource is online...
 254                                 stanza.attr.to = res.full_jid; -- reset at the end of function
 255                                 send(res, stanza); -- Yay \o/
 256                         end
 257                 else
 258                         -- user not online
 259                         if user_exists(node, host) then
 260                                 if stanza.name == "presence" then
 261                                         if stanza.attr.type == "probe" and is_authorized_to_see_presence(origin, node, host) then -- FIXME what to do for not c2s?
 262                                                 -- TODO send last recieved unavailable presence (or we MAY do nothing, which is fine too)
 263                                         else
 264                                                 -- TODO send unavailable presence
 265                                         end
 266                                 elseif stanza.name == "message" then
 267                                         -- TODO send message error, or store offline messages
 268                                 elseif stanza.name == "iq" then
 269                                         -- TODO send IQ error
 270                                 end
 271                         else -- user does not exist
 272                                 -- TODO we would get here for nodeless JIDs too. Do something fun maybe? Echo service? Let plugins use xmpp:server/resource addresses?
 273                                 if stanza.name == "presence" then
 274                                         if stanza.attr.type == "probe" then
 275                                                 send(origin, st.presence({from = to_bare, to = from_bare, type = "unsubscribed"}));
 276                                         end
 277                                         -- else ignore
 278                                 else
 279                                         send(origin, st.error_reply(stanza, "cancel", "service-unavailable"));
 280                                 end
 281                         end
 282                 end
 283         elseif origin.type == "c2s" then
 284                 -- Remote host
 285                 local xmlns = stanza.attr.xmlns;
 286                 --stanza.attr.xmlns = "jabber:server";
 287                 stanza.attr.xmlns = nil;
 288                 log("debug", "sending s2s stanza: %s", tostring(stanza));
 289                 send_s2s(origin.host, host, stanza); -- TODO handle remote routing errors
 290                 stanza.attr.xmlns = xmlns; -- reset
 291         else
 292                 log("warn", "received stanza from unhandled connection type: %s", origin.type);
 293         end
 294         stanza.attr.to = to; -- reset
 295 end
 296
 297 function handle_stanza_toremote(stanza)
 298         log("error", "Stanza bound for remote host, but s2s is not implemented");
 299 end