core/stanza_router.lua

   1 \r
   2 -- The code in this file should be self-explanatory, though the logic is horrible\r
   3 -- for more info on that, see doc/stanza_routing.txt, which attempts to condense\r
   4 -- the rules from the RFCs (mainly 3921)\r
   5 \r
   6 require "core.servermanager"\r
   7 \r
   8 local log = require "util.logger".init("stanzarouter")\r
   9 \r
  10 local st = require "util.stanza";\r
  11 local send = require "core.sessionmanager".send_to_session;\r
  12 -- local send_s2s = require "core.s2smanager".send_to_host;\r
  13 local user_exists = require "core.usermanager".user_exists;\r
  14 \r
  15 local jid_split = require "util.jid".split;\r
  16 local print, debug = print, debug;\r
  17 \r
  18 function core_process_stanza(origin, stanza)\r
  19         log("debug", "Received: "..tostring(stanza))\r
  20         -- TODO verify validity of stanza (as well as JID validity)\r
  21         if stanza.name == "iq" and not(#stanza.tags == 1 and stanza.tags[1].attr.xmlns) then\r
  22                 if stanza.attr.type == "set" or stanza.attr.type == "get" then\r
  23                         error("Invalid IQ");\r
  24                 elseif #stanza.tags > 1 or not(stanza.attr.type == "error" or stanza.attr.type == "result") then\r
  25                         error("Invalid IQ");\r
  26                 end\r
  27         end\r
  28 \r
  29         if origin.type == "c2s" and not origin.full_jid\r
  30                 and not(stanza.name == "iq" and stanza.tags[1].name == "bind"\r
  31                                 and stanza.tags[1].attr.xmlns == "urn:ietf:params:xml:ns:xmpp-bind") then\r
  32                 error("Client MUST bind resource after auth");\r
  33         end\r
  34 \r
  35         local to = stanza.attr.to;\r
  36         stanza.attr.from = origin.full_jid; -- quick fix to prevent impersonation (FIXME this would be incorrect when the origin is not c2s)\r
  37         -- TODO also, stazas should be returned to their original state before the function ends\r
  38         \r
  39         -- TODO presence subscriptions\r
  40         if not to then\r
  41                         core_handle_stanza(origin, stanza);\r
  42         elseif hosts[to] and hosts[to].type == "local" then\r
  43                 core_handle_stanza(origin, stanza);\r
  44         elseif stanza.name == "iq" and not select(3, jid_split(to)) then\r
  45                 core_handle_stanza(origin, stanza);\r
  46         elseif origin.type == "c2s" then\r
  47                 core_route_stanza(origin, stanza);\r
  48         end\r
  49 end\r
  50 \r
  51 -- This function handles stanzas which are not routed any further,\r
  52 -- that is, they are handled by this server\r
  53 function core_handle_stanza(origin, stanza)\r
  54         -- Handlers\r
  55         if origin.type == "c2s" or origin.type == "c2s_unauthed" then\r
  56                 local session = origin;\r
  57                 \r
  58                 if stanza.name == "presence" and origin.roster then\r
  59                         if stanza.attr.type == nil or stanza.attr.type == "available" or stanza.attr.type == "unavailable" then\r
  60                                 for jid in pairs(origin.roster) do -- broadcast to all interested contacts\r
  61                                         local subscription = origin.roster[jid].subscription;\r
  62                                         if subscription == "both" or subscription == "from" then\r
  63                                                 stanza.attr.to = jid;\r
  64                                                 core_route_stanza(origin, stanza);\r
  65                                         end\r
  66                                 end\r
  67                                 local node, host = jid_split(stanza.attr.from);\r
  68                                 for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast to all resources and from resources\r
  69                                         if res ~= origin then\r
  70                                                 if res.full_jid then -- to resource. FIXME is this check correct? Maybe it should be res.presence\r
  71                                                         stanza.attr.to = res.full_jid;\r
  72                                                         core_route_stanza(origin, stanza);\r
  73                                                 end\r
  74                                                 if res.presence then -- from all resources for which we have presence\r
  75                                                         res.presence.attr.to = origin.full_jid;\r
  76                                                         core_route_stanza(res, res.presence);\r
  77                                                         res.presence.attr.to = nil;\r
  78                                                 end\r
  79                                         end\r
  80                                 end\r
  81                                 if not origin.presence then -- presence probes on initial presence\r
  82                                         local probe = st.presence({from = origin.full_jid, type = "probe"});\r
  83                                         for jid in pairs(origin.roster) do\r
  84                                                 local subscription = origin.roster[jid].subscription;\r
  85                                                 if subscription == "both" or subscription == "to" then\r
  86                                                         probe.attr.to = jid;\r
  87                                                         core_route_stanza(origin, probe);\r
  88                                                 end\r
  89                                         end\r
  90                                 end\r
  91                                 origin.presence = stanza;\r
  92                                 stanza.attr.to = nil; -- reset it\r
  93                         else\r
  94                                 -- TODO error, bad type\r
  95                         end\r
  96                 else\r
  97                         log("debug", "Routing stanza to local");\r
  98                         handle_stanza(session, stanza);\r
  99                 end\r
 100         end\r
 101 end\r
 102 \r
 103 function is_authorized_to_see_presence(origin, username, host)\r
 104         local roster = datamanager.load(username, host, "roster") or {};\r
 105         local item = roster[origin.username.."@"..origin.host];\r
 106         return item and (item.subscription == "both" or item.subscription == "from");\r
 107 end\r
 108 \r
 109 function core_route_stanza(origin, stanza)\r
 110         -- Hooks\r
 111         --- ...later\r
 112         \r
 113         -- Deliver\r
 114         local to = stanza.attr.to;\r
 115         local node, host, resource = jid_split(to);\r
 116 \r
 117         if stanza.name == "presence" and (stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable") then resource = nil; end\r
 118 \r
 119         local host_session = hosts[host]\r
 120         if host_session and host_session.type == "local" then\r
 121                 -- Local host\r
 122                 local user = host_session.sessions[node];\r
 123                 if user then\r
 124                         local res = user.sessions[resource];\r
 125                         if not res then\r
 126                                 -- if we get here, resource was not specified or was unavailable\r
 127                                 if stanza.name == "presence" then\r
 128                                         if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then\r
 129                                                 if stanza.attr.type == "probe" then\r
 130                                                         if is_authorized_to_see_presence(origin, node, host) then\r
 131                                                                 for k in pairs(user.sessions) do -- return presence for all resources\r
 132                                                                         if user.sessions[k].presence then\r
 133                                                                                 local pres = user.sessions[k].presence;\r
 134                                                                                 pres.attr.to = origin.full_jid;\r
 135                                                                                 pres.attr.from = user.sessions[k].full_jid;\r
 136                                                                                 send(origin, pres);\r
 137                                                                                 pres.attr.to = nil;\r
 138                                                                                 pres.attr.from = nil;\r
 139                                                                         end\r
 140                                                                 end\r
 141                                                         else\r
 142                                                                 send(origin, st.presence({from=user.."@"..host, to=origin.username.."@"..origin.host, type="unsubscribed"}));\r
 143                                                         end\r
 144                                                 elseif stanza.attr.type == "subscribe" then\r
 145                                                         -- TODO\r
 146                                                 elseif stanza.attr.type == "unsubscribe" then\r
 147                                                         -- TODO\r
 148                                                 elseif stanza.attr.type == "subscribed" then\r
 149                                                         -- TODO\r
 150                                                 elseif stanza.attr.type == "unsubscribed" then\r
 151                                                         -- TODO\r
 152                                                 end -- discard any other type\r
 153                                         else -- sender is available or unavailable\r
 154                                                 for k in pairs(user.sessions) do -- presence broadcast to all user resources\r
 155                                                         if user.sessions[k].full_jid then\r
 156                                                                 stanza.attr.to = user.sessions[k].full_jid;\r
 157                                                                 send(user.sessions[k], stanza);\r
 158                                                         end\r
 159                                                 end\r
 160                                         end\r
 161                                 elseif stanza.name == "message" then -- select a resource to recieve message\r
 162                                         for k in pairs(user.sessions) do\r
 163                                                 if user.sessions[k].full_jid then\r
 164                                                         res = user.sessions[k];\r
 165                                                         break;\r
 166                                                 end\r
 167                                         end\r
 168                                         -- TODO find resource with greatest priority\r
 169                                         send(res, stanza);\r
 170                                 else\r
 171                                         -- TODO send IQ error\r
 172                                 end\r
 173                         else\r
 174                                 -- User + resource is online...\r
 175                                 stanza.attr.to = res.full_jid;\r
 176                                 send(res, stanza); -- Yay \o/\r
 177                         end\r
 178                 else\r
 179                         -- user not online\r
 180                         if user_exists(node, host) then\r
 181                                 if stanza.name == "presence" then\r
 182                                         if stanza.attr.type == "probe" and is_authorized_to_see_presence(origin, node, host) then -- FIXME what to do for not c2s?\r
 183                                                 -- TODO send last recieved unavailable presence\r
 184                                         else\r
 185                                                 -- TODO send unavailable presence\r
 186                                         end\r
 187                                 elseif stanza.name == "message" then\r
 188                                         -- TODO send message error, or store offline messages\r
 189                                 elseif stanza.name == "iq" then\r
 190                                         -- TODO send IQ error\r
 191                                 end\r
 192                         else -- user does not exist\r
 193                                 -- TODO we would get here for nodeless JIDs too. Do something fun maybe? Echo service? Let plugins use xmpp:server/resource addresses?\r
 194                                 if stanza.name == "presence" then\r
 195                                         if stanza.attr.type == "probe" then\r
 196                                                 send(origin, st.presence({from = user.."@"..host, to = origin.username.."@"..origin.host, type = "unsubscribed"}));\r
 197                                         end\r
 198                                         -- else ignore\r
 199                                 else\r
 200                                         send(origin, st.error_reply(stanza, "cancel", "service-unavailable"));\r
 201                                 end\r
 202                         end\r
 203                 end\r
 204         else\r
 205                 -- Remote host\r
 206                 if host_session then\r
 207                         -- Send to session\r
 208                 else\r
 209                         -- Need to establish the connection\r
 210                 end\r
 211         end\r
 212         stanza.attr.to = to; -- reset\r
 213 end\r
 214 \r
 215 function handle_stanza_toremote(stanza)\r
 216         log("error", "Stanza bound for remote host, but s2s is not implemented");\r
 217 end\r