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 user_exists = require "core.usermanager".user_exists;
  13
  14 local jid_split = require "util.jid".split;
  15 local print, debug = print, debug;
  16
  17 function core_process_stanza(origin, stanza)
  18         log("debug", "Received: "..tostring(stanza))
  19         -- TODO verify validity of stanza (as well as JID validity)
  20         if stanza.name == "iq" and not(#stanza.tags == 1 and stanza.tags[1].attr.xmlns) then
  21                 if stanza.attr.type == "set" or stanza.attr.type == "get" then
  22                         error("Invalid IQ");
  23                 elseif #stanza.tags > 1 or not(stanza.attr.type == "error" or stanza.attr.type == "result") then
  24                         error("Invalid IQ");
  25                 end
  26         end
  27
  28         if origin.type == "c2s" and not origin.full_jid
  29                 and not(stanza.name == "iq" and stanza.tags[1].name == "bind"
  30                                 and stanza.tags[1].attr.xmlns == "urn:ietf:params:xml:ns:xmpp-bind") then
  31                 error("Client MUST bind resource after auth");
  32         end
  33
  34         local to = stanza.attr.to;
  35         stanza.attr.from = origin.full_jid; -- quick fix to prevent impersonation (FIXME this would be incorrect when the origin is not c2s)
  36         -- TODO also, stazas should be returned to their original state before the function ends
  37
  38         -- TODO presence subscriptions
  39         if not to then
  40                         core_handle_stanza(origin, stanza);
  41         elseif hosts[to] and hosts[to].type == "local" then
  42                 core_handle_stanza(origin, stanza);
  43         elseif stanza.name == "iq" and not select(3, jid_split(to)) then
  44                 core_handle_stanza(origin, stanza);
  45         elseif origin.type == "c2s" then
  46                 core_route_stanza(origin, stanza);
  47         end
  48 end
  49
  50 -- This function handles stanzas which are not routed any further,
  51 -- that is, they are handled by this server
  52 function core_handle_stanza(origin, stanza)
  53         -- Handlers
  54         if origin.type == "c2s" or origin.type == "c2s_unauthed" then
  55                 local session = origin;
  56
  57                 if stanza.name == "presence" and origin.roster then
  58                         if stanza.attr.type == nil or stanza.attr.type == "available" or stanza.attr.type == "unavailable" then
  59                                 for jid in pairs(origin.roster) do -- broadcast to all interested contacts
  60                                         local subscription = origin.roster[jid].subscription;
  61                                         if subscription == "both" or subscription == "from" then
  62                                                 stanza.attr.to = jid;
  63                                                 core_route_stanza(origin, stanza);
  64                                         end
  65                                 end
  66                                 local node, host = jid_split(stanza.attr.from);
  67                                 for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast to all resources and from resources
  68                                         if res ~= origin then
  69                                                 if res.full_jid then -- to resource. FIXME is this check correct? Maybe it should be res.presence
  70                                                         stanza.attr.to = res.full_jid;
  71                                                         core_route_stanza(origin, stanza);
  72                                                 end
  73                                                 if res.presence then -- from all resources for which we have presence
  74                                                         res.presence.attr.to = origin.full_jid;
  75                                                         core_route_stanza(res, res.presence);
  76                                                         res.presence.attr.to = nil;
  77                                                 end
  78                                         end
  79                                 end
  80                                 if not origin.presence then -- presence probes on initial presence
  81                                         local probe = st.presence({from = origin.full_jid, type = "probe"});
  82                                         for jid in pairs(origin.roster) do
  83                                                 local subscription = origin.roster[jid].subscription;
  84                                                 if subscription == "both" or subscription == "to" then
  85                                                         probe.attr.to = jid;
  86                                                         core_route_stanza(origin, probe);
  87                                                 end
  88                                         end
  89                                 end
  90                                 origin.presence = stanza;
  91                                 stanza.attr.to = nil; -- reset it
  92                         else
  93                                 -- TODO error, bad type
  94                         end
  95                 else
  96                         log("debug", "Routing stanza to local");
  97                         handle_stanza(session, stanza);
  98                 end
  99         end
 100 end
 101
 102 function is_authorized_to_see_presence(origin, username, host)
 103         local roster = datamanager.load(username, host, "roster") or {};
 104         local item = roster[origin.username.."@"..origin.host];
 105         return item and (item.subscription == "both" or item.subscription == "from");
 106 end
 107
 108 function core_route_stanza(origin, stanza)
 109         -- Hooks
 110         --- ...later
 111
 112         -- Deliver
 113         local to = stanza.attr.to;
 114         local node, host, resource = jid_split(to);
 115
 116         if stanza.name == "presence" and (stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable") then resource = nil; end
 117
 118         local host_session = hosts[host]
 119         if host_session and host_session.type == "local" then
 120                 -- Local host
 121                 local user = host_session.sessions[node];
 122                 if user then
 123                         local res = user.sessions[resource];
 124                         if not res then
 125                                 -- if we get here, resource was not specified or was unavailable
 126                                 if stanza.name == "presence" then
 127                                         if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then
 128                                                 if stanza.attr.type == "probe" then
 129                                                         if is_authorized_to_see_presence(origin, node, host) then
 130                                                                 for k in pairs(user.sessions) do -- return presence for all resources
 131                                                                         if user.sessions[k].presence then
 132                                                                                 local pres = user.sessions[k].presence;
 133                                                                                 pres.attr.to = origin.full_jid;
 134                                                                                 pres.attr.from = user.sessions[k].full_jid;
 135                                                                                 send(origin, pres);
 136                                                                                 pres.attr.to = nil;
 137                                                                                 pres.attr.from = nil;
 138                                                                         end
 139                                                                 end
 140                                                         else
 141                                                                 send(origin, st.presence({from=user.."@"..host, to=origin.username.."@"..origin.host, type="unsubscribed"}));
 142                                                         end
 143                                                 elseif stanza.attr.type == "subscribe" then
 144                                                         -- TODO
 145                                                 elseif stanza.attr.type == "unsubscribe" then
 146                                                         -- TODO
 147                                                 elseif stanza.attr.type == "subscribed" then
 148                                                         -- TODO
 149                                                 elseif stanza.attr.type == "unsubscribed" then
 150                                                         -- TODO
 151                                                 end -- discard any other type
 152                                         else -- sender is available or unavailable
 153                                                 for k in pairs(user.sessions) do -- presence broadcast to all user resources
 154                                                         if user.sessions[k].full_jid then
 155                                                                 stanza.attr.to = user.sessions[k].full_jid;
 156                                                                 send(user.sessions[k], stanza);
 157                                                         end
 158                                                 end
 159                                         end
 160                                 elseif stanza.name == "message" then -- select a resource to recieve message
 161                                         for k in pairs(user.sessions) do
 162                                                 if user.sessions[k].full_jid then
 163                                                         res = user.sessions[k];
 164                                                         break;
 165                                                 end
 166                                         end
 167                                         -- TODO find resource with greatest priority
 168                                         send(res, stanza);
 169                                 else
 170                                         -- TODO send IQ error
 171                                 end
 172                         else
 173                                 -- User + resource is online...
 174                                 stanza.attr.to = res.full_jid;
 175                                 send(res, stanza); -- Yay \o/
 176                         end
 177                 else
 178                         -- user not online
 179                         if user_exists(node, host) then
 180                                 if stanza.name == "presence" then
 181                                         if stanza.attr.type == "probe" and is_authorized_to_see_presence(origin, node, host) then -- FIXME what to do for not c2s?
 182                                                 -- TODO send last recieved unavailable presence
 183                                         else
 184                                                 -- TODO send unavailable presence
 185                                         end
 186                                 elseif stanza.name == "message" then
 187                                         -- TODO send message error, or store offline messages
 188                                 elseif stanza.name == "iq" then
 189                                         -- TODO send IQ error
 190                                 end
 191                         else -- user does not exist
 192                                 -- TODO we would get here for nodeless JIDs too. Do something fun maybe? Echo service? Let plugins use xmpp:server/resource addresses?
 193                                 if stanza.name == "presence" then
 194                                         if stanza.attr.type == "probe" then
 195                                                 send(origin, st.presence({from = user.."@"..host, to = origin.username.."@"..origin.host, type = "unsubscribed"}));
 196                                         end
 197                                         -- else ignore
 198                                 else
 199                                         send(origin, st.error_reply(stanza, "cancel", "service-unavailable"));
 200                                 end
 201                         end
 202                 end
 203         else
 204                 -- Remote host
 205                 if host_session then
 206                         -- Send to session
 207                 else
 208                         -- Need to establish the connection
 209                 end
 210         end
 211         stanza.attr.to = to; -- reset
 212 end
 213
 214 function handle_stanza_toremote(stanza)
 215         log("error", "Stanza bound for remote host, but s2s is not implemented");
 216 end