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 jid_split = require "util.jid".split;
  16 local print = print;
  17
  18 function core_process_stanza(origin, stanza)
  19         log("debug", "Received: "..tostring(stanza))
  20         -- TODO verify validity of stanza (as well as JID validity)
  21         if stanza.name == "iq" and not(#stanza.tags == 1 and stanza.tags[1].attr.xmlns) then
  22                 if stanza.attr.type == "set" or stanza.attr.type == "get" then
  23                         error("Invalid IQ");
  24                 elseif #stanza.tags > 1 or not(stanza.attr.type == "error" or stanza.attr.type == "result") then
  25                         error("Invalid IQ");
  26                 end
  27         end
  28
  29         if origin.type == "c2s" and not origin.full_jid
  30                 and not(stanza.name == "iq" and stanza.tags[1].name == "bind"
  31                                 and stanza.tags[1].attr.xmlns == "urn:ietf:params:xml:ns:xmpp-bind") then
  32                 error("Client MUST bind resource after auth");
  33         end
  34
  35         local to = stanza.attr.to;
  36         stanza.attr.from = origin.full_jid; -- quick fix to prevent impersonation (FIXME this would be incorrect when the origin is not c2s)
  37         -- TODO also, stazas should be returned to their original state before the function ends
  38
  39         -- TODO presence subscriptions
  40         if not to then
  41                         core_handle_stanza(origin, stanza);
  42         elseif hosts[to] and hosts[to].type == "local" then
  43                 core_handle_stanza(origin, stanza);
  44         elseif stanza.name == "iq" and not select(3, jid_split(to)) then
  45                 core_handle_stanza(origin, stanza);
  46         elseif origin.type == "c2s" then
  47                 core_route_stanza(origin, stanza);
  48         end
  49 end
  50
  51 -- This function handles stanzas which are not routed any further,
  52 -- that is, they are handled by this server
  53 function core_handle_stanza(origin, stanza)
  54         -- Handlers
  55         if origin.type == "c2s" or origin.type == "c2s_unauthed" then
  56                 local session = origin;
  57
  58                 if stanza.name == "presence" and origin.roster then
  59                         if stanza.attr.type == nil or stanza.attr.type == "available" or stanza.attr.type == "unavailable" then
  60                                 for jid in pairs(origin.roster) do -- broadcast to all interested contacts
  61                                         local subscription = origin.roster[jid].subscription;
  62                                         if subscription == "both" or subscription == "from" then
  63                                                 stanza.attr.to = jid;
  64                                                 core_route_stanza(origin, stanza);
  65                                         end
  66                                 end
  67                                 --[[local node, host = jid_split(stanza.attr.from);
  68                                 for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast to all resources
  69                                         if res.full_jid then
  70                                                 res = user.sessions[k];
  71                                                 break;
  72                                         end
  73                                 end]]
  74                                 if not origin.presence then -- presence probes on initial presence
  75                                         local probe = st.presence({from = origin.full_jid, type = "probe"});
  76                                         for jid in pairs(origin.roster) do
  77                                                 local subscription = origin.roster[jid].subscription;
  78                                                 if subscription == "both" or subscription == "to" then
  79                                                         probe.attr.to = jid;
  80                                                         core_route_stanza(origin, probe);
  81                                                 end
  82                                         end
  83                                 end
  84                                 origin.presence = stanza;
  85                                 stanza.attr.to = nil; -- reset it
  86                         else
  87                                 -- TODO error, bad type
  88                         end
  89                 else
  90                         log("debug", "Routing stanza to local");
  91                         handle_stanza(session, stanza);
  92                 end
  93         end
  94 end
  95
  96 -- TODO: Does this function belong here?
  97 function is_authorized_to_see_presence(origin, username, host)
  98         local roster = datamanager.load(username, host, "roster") or {};
  99         local item = roster[origin.username.."@"..origin.host];
 100         return item and (item.subscription == "both" or item.subscription == "from");
 101 end
 102
 103 function core_route_stanza(origin, stanza)
 104         -- Hooks
 105         --- ...later
 106
 107         -- Deliver
 108         local to = stanza.attr.to;
 109         local node, host, resource = jid_split(to);
 110
 111         if stanza.name == "presence" and stanza.attr.type == "probe" then resource = nil; end
 112
 113         local host_session = hosts[host]
 114         if host_session and host_session.type == "local" then
 115                 -- Local host
 116                 local user = host_session.sessions[node];
 117                 if user then
 118                         local res = user.sessions[resource];
 119                         if not res then
 120                                 -- if we get here, resource was not specified or was unavailable
 121                                 if stanza.name == "presence" then
 122                                         if stanza.attr.type == "probe" then
 123                                                 if is_authorized_to_see_presence(origin, node, host) then
 124                                                         for k in pairs(user.sessions) do -- return presence for all resources
 125                                                                 if user.sessions[k].presence then
 126                                                                         local pres = user.sessions[k].presence;
 127                                                                         pres.attr.to = origin.full_jid;
 128                                                                         pres.attr.from = user.sessions[k].full_jid;
 129                                                                         send(origin, pres);
 130                                                                         pres.attr.to = nil;
 131                                                                         pres.attr.from = nil;
 132                                                                 end
 133                                                         end
 134                                                 else
 135                                                         send(origin, st.presence({from = user.."@"..host, to = origin.username.."@"..origin.host, type = "unsubscribed"}));
 136                                                 end
 137                                         else
 138                                                 for k in pairs(user.sessions) do -- presence broadcast to all user resources
 139                                                         if user.sessions[k].full_jid then
 140                                                                 stanza.attr.to = user.sessions[k].full_jid;
 141                                                                 send(user.sessions[k], stanza);
 142                                                         end
 143                                                 end
 144                                         end
 145                                 elseif stanza.name == "message" then -- select a resource to recieve message
 146                                         for k in pairs(user.sessions) do
 147                                                 if user.sessions[k].full_jid then
 148                                                         res = user.sessions[k];
 149                                                         break;
 150                                                 end
 151                                         end
 152                                         -- TODO find resource with greatest priority
 153                                         send(res, stanza);
 154                                 else
 155                                         -- TODO send IQ error
 156                                 end
 157                         else
 158                                 -- User + resource is online...
 159                                 stanza.attr.to = res.full_jid;
 160                                 send(res, stanza); -- Yay \o/
 161                         end
 162                 else
 163                         -- user not online
 164                         if user_exists(node, host) then
 165                                 if stanza.name == "presence" then
 166                                         if stanza.attr.type == "probe" and is_authorized_to_see_presence(origin, node, host) then -- FIXME what to do for not c2s?
 167                                                 -- TODO send last recieved unavailable presence
 168                                         else
 169                                                 -- TODO send unavailable presence
 170                                         end
 171                                 elseif stanza.name == "message" then
 172                                         -- TODO send message error, or store offline messages
 173                                 elseif stanza.name == "iq" then
 174                                         -- TODO send IQ error
 175                                 end
 176                         else -- user does not exist
 177                                 -- TODO we would get here for nodeless JIDs too. Do something fun maybe? Echo service? Let plugins use xmpp:server/resource addresses?
 178                                 if stanza.name == "presence" then
 179                                         if stanza.attr.type == "probe" then
 180                                                 send(origin, st.presence({from = user.."@"..host, to = origin.username.."@"..origin.host, type = "unsubscribed"}));
 181                                         end
 182                                         -- else ignore
 183                                 else
 184                                         send(origin, st.error_reply(stanza, "cancel", "service-unavailable"));
 185                                 end
 186                         end
 187                 end
 188         else
 189                 -- Remote host
 190                 send_s2s(origin.host, host, stanza);
 191         end
 192         stanza.attr.to = to; -- reset
 193 end
 194
 195 function handle_stanza_toremote(stanza)
 196         log("error", "Stanza bound for remote host, but s2s is not implemented");
 197 end