core/s2smanager.lua

   1
   2 local hosts = hosts;
   3 local sessions = sessions;
   4 local socket = require "socket";
   5 local format = string.format;
   6 local t_insert, t_sort = table.insert, table.sort;
   7 local get_traceback = debug.traceback;
   8 local tostring, pairs, ipairs, getmetatable, print, newproxy, error, tonumber
   9     = tostring, pairs, ipairs, getmetatable, print, newproxy, error, tonumber;
  10
  11 local connlisteners_get = require "net.connlisteners".get;
  12 local wraptlsclient = require "net.server".wraptlsclient;
  13 local modulemanager = require "core.modulemanager";
  14 local st = require "stanza";
  15 local stanza = st.stanza;
  16
  17 local uuid_gen = require "util.uuid".generate;
  18
  19 local logger_init = require "util.logger".init;
  20
  21 local log = logger_init("s2smanager");
  22
  23 local md5_hash = require "util.hashes".md5;
  24
  25 local dialback_secret = "This is very secret!!! Ha!";
  26
  27 local dns = require "net.dns";
  28
  29 module "s2smanager"
  30
  31 local function compare_srv_priorities(a,b) return a.priority < b.priority or a.weight < b.weight; end
  32
  33 function send_to_host(from_host, to_host, data)
  34         if data.name then data = tostring(data); end
  35         local host = hosts[from_host].s2sout[to_host];
  36         if host then
  37                 -- We have a connection to this host already
  38                 if host.type == "s2sout_unauthed" and ((not data.xmlns) or data.xmlns == "jabber:client" or data.xmlns == "jabber:server") then
  39                         (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host..", authing it now...");
  40                         if not host.notopen and not host.dialback_key then
  41                                 host.log("debug", "dialback had not been initiated");
  42                                 initiate_dialback(host);
  43                         end
  44
  45                         -- Queue stanza until we are able to send it
  46                         if host.sendq then t_insert(host.sendq, data);
  47                         else host.sendq = { data }; end
  48                 elseif host.type == "local" or host.type == "component" then
  49                         log("error", "Trying to send a stanza to ourselves??")
  50                         log("error", "Traceback: %s", get_traceback());
  51                         log("error", "Stanza: %s", tostring(data));
  52                 else
  53                         (host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
  54                         -- FIXME
  55                         if host.from_host ~= from_host then
  56                                 log("error", "WARNING! This might, possibly, be a bug, but it might not...");
  57                                 log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
  58                         end
  59                         host.sends2s(data);
  60                         host.log("debug", "stanza sent over "..host.type);
  61                 end
  62         else
  63                 log("debug", "opening a new outgoing connection for this stanza");
  64                 local host_session = new_outgoing(from_host, to_host);
  65                 -- Store in buffer
  66                 host_session.sendq = { data };
  67         end
  68 end
  69
  70 local open_sessions = 0;
  71
  72 function new_incoming(conn)
  73         local session = { conn = conn, type = "s2sin_unauthed", direction = "incoming" };
  74         if true then
  75                 session.trace = newproxy(true);
  76                 getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; print("s2s session got collected, now "..open_sessions.." s2s sessions are allocated") end;
  77         end
  78         open_sessions = open_sessions + 1;
  79         local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
  80         session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
  81         return session;
  82 end
  83
  84 function new_outgoing(from_host, to_host)
  85                 local host_session = { to_host = to_host, from_host = from_host, notopen = true, type = "s2sout_unauthed", direction = "outgoing" };
  86                 hosts[from_host].s2sout[to_host] = host_session;
  87                 local cl = connlisteners_get("xmppserver");
  88
  89                 local conn, handler = socket.tcp()
  90
  91                 local connect_host, connect_port = to_host, 5269;
  92
  93                 local answer = dns.lookup("_xmpp-server._tcp."..to_host..".", "SRV");
  94
  95                 if answer then
  96                         log("debug", to_host.." has SRV records, handling...");
  97                         local srv_hosts = {};
  98                         host_session.srv_hosts = srv_hosts;
  99                         for _, record in ipairs(answer) do
 100                                 t_insert(srv_hosts, record.srv);
 101                         end
 102                         t_sort(srv_hosts, compare_srv_priorities);
 103
 104                         local srv_choice = srv_hosts[1];
 105                         if srv_choice then
 106                                 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
 107                                 log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
 108                         end
 109                 end
 110
 111                 conn:settimeout(0);
 112                 local success, err = conn:connect(connect_host, connect_port);
 113                 if not success and err ~= "timeout" then
 114                         log("warn", "s2s connect() failed: %s", err);
 115                 end
 116
 117                 conn = wraptlsclient(cl, conn, connect_host, connect_port, 0, 1, hosts[from_host].ssl_ctx );
 118                 host_session.conn = conn;
 119
 120                 -- Register this outgoing connection so that xmppserver_listener knows about it
 121                 -- otherwise it will assume it is a new incoming connection
 122                 cl.register_outgoing(conn, host_session);
 123
 124                 local log;
 125                 do
 126                         local conn_name = "s2sout"..tostring(conn):match("[a-f0-9]*$");
 127                         log = logger_init(conn_name);
 128                         host_session.log = log;
 129                 end
 130
 131                 local w = conn.write;
 132                 host_session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
 133
 134                 conn.write(format([[<stream:stream xmlns='jabber:server' xmlns:db='jabber:server:dialback' xmlns:stream='http://etherx.jabber.org/streams' from='%s' to='%s' version='1.0'>]], from_host, to_host));
 135
 136                 return host_session;
 137 end
 138
 139 function streamopened(session, attr)
 140         local send = session.sends2s;
 141
 142         session.version = tonumber(attr.version) or 0;
 143         if session.version >= 1.0 and not (attr.to and attr.from) then
 144                 --print("to: "..tostring(attr.to).." from: "..tostring(attr.from));
 145                 log("warn", (session.to_host or "(unknown)").." failed to specify 'to' or 'from' hostname as per RFC");
 146         end
 147
 148         if session.direction == "incoming" then
 149                 -- Send a reply stream header
 150
 151                 --for k,v in pairs(attr) do print("", tostring(k), ":::", tostring(v)); end
 152
 153                 session.to_host = attr.to;
 154                 session.from_host = attr.from;
 155
 156                 session.streamid = uuid_gen();
 157                 (session.log or log)("debug", "incoming s2s received <stream:stream>");
 158                 send("<?xml version='1.0'?>");
 159                 send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback', ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host }):top_tag());
 160                 if session.to_host and not hosts[session.to_host] then
 161                         -- Attempting to connect to a host we don't serve
 162                         session:close("host-unknown");
 163                         return;
 164                 end
 165                 if session.version >= 1.0 then
 166                         send(st.stanza("stream:features")
 167                                         :tag("dialback", { xmlns='urn:xmpp:features:dialback' }):tag("optional"):up():up());
 168                 end
 169         elseif session.direction == "outgoing" then
 170                 -- If we are just using the connection for verifying dialback keys, we won't try and auth it
 171                 if not attr.id then error("stream response did not give us a streamid!!!"); end
 172                 session.streamid = attr.id;
 173
 174                 if not session.dialback_verifying then
 175                         initiate_dialback(session);
 176                 else
 177                         mark_connected(session);
 178                 end
 179         end
 180
 181         session.notopen = nil;
 182 end
 183
 184 function initiate_dialback(session)
 185         -- generate dialback key
 186         session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
 187         session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key));
 188         session.log("info", "sent dialback key on outgoing s2s stream");
 189 end
 190
 191 function generate_dialback(id, to, from)
 192         return md5_hash(id..to..from..dialback_secret); -- FIXME: See XEP-185 and XEP-220
 193 end
 194
 195 function verify_dialback(id, to, from, key)
 196         return key == generate_dialback(id, to, from);
 197 end
 198
 199 function make_authenticated(session)
 200         if session.type == "s2sout_unauthed" then
 201                 session.type = "s2sout";
 202         elseif session.type == "s2sin_unauthed" then
 203                 session.type = "s2sin";
 204         else
 205                 return false;
 206         end
 207         session.log("info", "connection is now authenticated");
 208
 209         mark_connected(session);
 210
 211         return true;
 212 end
 213
 214 function mark_connected(session)
 215         local sendq, send = session.sendq, session.sends2s;
 216
 217         local from, to = session.from_host, session.to_host;
 218
 219         session.log("debug", session.direction.." s2s connection "..from.."->"..to.." is now complete");
 220
 221         local send_to_host = send_to_host;
 222         function session.send(data) send_to_host(to, from, data); end
 223
 224
 225         if session.direction == "outgoing" then
 226                 if sendq then
 227                         session.log("debug", "sending "..#sendq.." queued stanzas across new outgoing connection to "..session.to_host);
 228                         for i, data in ipairs(sendq) do
 229                                 send(data);
 230                                 sendq[i] = nil;
 231                         end
 232                         session.sendq = nil;
 233                 end
 234         end
 235 end
 236
 237 function destroy_session(session)
 238         (session.log or log)("info", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host));
 239
 240         -- FIXME: Flush sendq here/report errors to originators
 241
 242         if session.direction == "outgoing" then
 243                 hosts[session.from_host].s2sout[session.to_host] = nil;
 244         end
 245
 246         for k in pairs(session) do
 247                 if k ~= "trace" then
 248                         session[k] = nil;
 249                 end
 250         end
 251 end
 252
 253 return _M;