util.pposix: Replace the unwieldy module table generation with luaL_register() call...
[prosody.git] / core / s2smanager.lua
index 6388168fb1b4b518ac3b6d9b10999d3f1325efbf..af5e91e3585705eb946b68a2ca3759a53848232c 100644 (file)
@@ -27,6 +27,7 @@ local st = require "stanza";
 local stanza = st.stanza;
 local nameprep = require "util.encodings".stringprep.nameprep;
 
+local fire_event = require "core.eventmanager".fire_event;
 local uuid_gen = require "util.uuid".generate;
 
 local logger_init = require "util.logger".init;
@@ -35,21 +36,21 @@ local log = logger_init("s2smanager");
 
 local sha256_hash = require "util.hashes".sha256;
 
-local dialback_secret = uuid_gen();
-
 local adns, dns = require "net.adns", require "net.dns";
-
+local config = require "core.configmanager";
 local connect_timeout = config.get("*", "core", "s2s_timeout") or 60;
 local dns_timeout = config.get("*", "core", "dns_timeout") or 60;
+local max_dns_depth = config.get("*", "core", "dns_max_depth") or 3;
 
 incoming_s2s = {};
+_G.prosody.incoming_s2s = incoming_s2s;
 local incoming_s2s = incoming_s2s;
 
 module "s2smanager"
 
 local function compare_srv_priorities(a,b) return a.priority < b.priority or a.weight < b.weight; end
 
-local function bounce_sendq(session)
+local function bounce_sendq(session, reason)
        local sendq = session.sendq;
        if sendq then
                session.log("info", "sending error replies for "..#sendq.." queued stanzas because of failed outgoing connection to "..tostring(session.to_host));
@@ -67,6 +68,9 @@ local function bounce_sendq(session)
                                reply.attr.type = "error";
                                reply:tag("error", {type = "cancel"})
                                        :tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
+                               if reason then
+                                       reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):text("Connection failed: "..reason):up();
+                               end
                                core_process_stanza(dummy, reply);
                        end
                        sendq[i] = nil;
@@ -76,15 +80,15 @@ local function bounce_sendq(session)
 end
 
 function send_to_host(from_host, to_host, data)
+       if not hosts[from_host] then
+               log("warn", "Attempt to send stanza from %s - a host we don't serve", from_host);
+               return false;
+       end
        local host = hosts[from_host].s2sout[to_host];
        if host then
                -- We have a connection to this host already
-               if host.type == "s2sout_unauthed" and data.name ~= "db:verify" and ((not data.xmlns) or data.xmlns == "jabber:client" or data.xmlns == "jabber:server") then
+               if host.type == "s2sout_unauthed" and (data.name ~= "db:verify" or not host.dialback_key) and ((not data.xmlns) or data.xmlns == "jabber:client" or data.xmlns == "jabber:server") then
                        (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
-                       if not host.notopen and not host.dialback_key and host.sends2s then
-                               host.log("debug", "dialback had not been initiated");
-                               initiate_dialback(host);
-                       end
                        
                        -- Queue stanza until we are able to send it
                        if host.sendq then t_insert(host.sendq, {tostring(data), st.reply(data)});
@@ -107,6 +111,7 @@ function send_to_host(from_host, to_host, data)
        else
                log("debug", "opening a new outgoing connection for this stanza");
                local host_session = new_outgoing(from_host, to_host);
+
                -- Store in buffer
                host_session.sendq = { {tostring(data), st.reply(data)} };
                log("debug", "stanza [%s] queued until connection complete", tostring(data.name));
@@ -127,7 +132,8 @@ function new_incoming(conn)
        end
        open_sessions = open_sessions + 1;
        local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
-       session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
+       session.log = log;
+       session.sends2s = function (t) log("debug", "sending: %s", t.top_tag and t:top_tag() or t:match("^([^>]*>?)")); w(conn, tostring(t)); end
        incoming_s2s[session] = true;
        add_task(connect_timeout, function ()
                if session.conn ~= conn or
@@ -135,15 +141,18 @@ function new_incoming(conn)
                        return; -- Ok, we're connect[ed|ing]
                end
                -- Not connected, need to close session and clean up
-               (session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity", 
+               (session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity",
                    session.from_host or "(unknown)", session.to_host or "(unknown)");
                session:close("connection-timeout");
        end);
        return session;
 end
 
-function new_outgoing(from_host, to_host)
-               local host_session = { to_host = to_host, from_host = from_host, notopen = true, type = "s2sout_unauthed", direction = "outgoing" };
+function new_outgoing(from_host, to_host, connect)
+               local host_session = { to_host = to_host, from_host = from_host, host = from_host,
+                                      notopen = true, type = "s2sout_unauthed", direction = "outgoing",
+                                      open_stream = session_open_stream };
+               
                hosts[from_host].s2sout[to_host] = host_session;
                
                local log;
@@ -153,10 +162,12 @@ function new_outgoing(from_host, to_host)
                        host_session.log = log;
                end
                
-               -- This is the first call, can't fail (the first step is DNS lookup)
-               attempt_connection(host_session);
+               if connect ~= false then
+                       -- Kick the connection attempting machine into life
+                       attempt_connection(host_session);
+               end
                
-               if not host_session.sends2s then                
+               if not host_session.sends2s then
                        -- A sends2s which buffers data (until the stream is opened)
                        -- note that data in this buffer will be sent before the stream is authed
                        -- and will not be ack'd in any way, successful or otherwise
@@ -181,6 +192,10 @@ function attempt_connection(host_session, err)
        local from_host, to_host = host_session.from_host, host_session.to_host;
        local connect_host, connect_port = idna_to_ascii(to_host), 5269;
        
+       if not connect_host then
+               return false;
+       end
+       
        if not err then -- This is our first attempt
                log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
                host_session.connecting = true;
@@ -211,7 +226,7 @@ function attempt_connection(host_session, err)
                        if not ok then
                                if not attempt_connection(host_session, err) then
                                        -- No more attempts will be made
-                                       destroy_session(host_session);
+                                       destroy_session(host_session, err);
                                end
                        end
                end, "_xmpp-server._tcp."..connect_host..".", "SRV");
@@ -253,22 +268,25 @@ function try_connect(host_session, connect_host, connect_port)
                host_session.connecting = nil;
                
                -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
-               if not (reply and reply[1] and reply[1].a) then
+               if not (reply and reply[#reply] and reply[#reply].a) then
+                       local count = max_dns_depth;
                        reply = dns.peek(connect_host, "CNAME", "IN");
-                       while reply and reply[1] and not reply[1].a and reply[1].cname do
-                               reply = dns.peek(reply[1].cname, "A", "IN") or dns.peek(reply[1].cname, "CNAME", "IN");
+                       while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
+                               log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
+                               reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
+                               count = count - 1;
                        end
                end
                -- end of CNAME resolving
                
-               if reply and reply[1] and reply[1].a then
-                       log("debug", "DNS reply for %s gives us %s", connect_host, reply[1].a);
-                       return make_connect(host_session, reply[1].a, connect_port);
+               if reply and reply[#reply] and reply[#reply].a then
+                       log("debug", "DNS reply for %s gives us %s", connect_host, reply[#reply].a);
+                       return make_connect(host_session, reply[#reply].a, connect_port);
                else
                        log("debug", "DNS lookup failed to get a response for %s", connect_host);
                        if not attempt_connection(host_session, "name resolution failed") then -- Retry if we can
                                log("debug", "No other records to try for %s - destroying", host_session.to_host);
-                               destroy_session(host_session); -- End of the line, we can't
+                               destroy_session(host_session, "DNS resolution failed"); -- End of the line, we can't
                        end
                end
        end, connect_host, "A", "IN");
@@ -279,7 +297,7 @@ function try_connect(host_session, connect_host, connect_port)
                        adns.cancel(handle, true);
                end
        end);
-               
+       
        return true;
 end
 
@@ -306,10 +324,11 @@ function make_connect(host_session, connect_host, connect_port)
        -- otherwise it will assume it is a new incoming connection
        cl.register_outgoing(conn, host_session);
        
-       local w = conn.write;
-       host_session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
+       local w, log = conn.write, host_session.log;
+       host_session.sends2s = function (t) log("debug", "sending: %s", (t.top_tag and t:top_tag()) or t:match("^[^>]*>?")); w(conn, tostring(t)); end
+       
+       host_session:open_stream();
        
-       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' xml:lang='en'>]], from_host, to_host));
        log("debug", "Connection attempt in progress...");
        add_task(connect_timeout, function ()
                if host_session.conn ~= conn or
@@ -318,21 +337,33 @@ function make_connect(host_session, connect_host, connect_port)
                        return; -- Ok, we're connect[ed|ing]
                end
                -- Not connected, need to close session and clean up
-               (host_session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity", 
+               (host_session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity",
                    host_session.from_host or "(unknown)", host_session.to_host or "(unknown)");
                host_session:close("connection-timeout");
        end);
        return true;
 end
 
+function session_open_stream(session, from, to)
+       session.sends2s(st.stanza("stream:stream", {
+               xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
+               ["xmlns:stream"]='http://etherx.jabber.org/streams',
+               from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
+end
+
 function streamopened(session, attr)
        local send = session.sends2s;
        
        -- TODO: #29: SASL/TLS on s2s streams
-       session.version = 0; --tonumber(attr.version) or 0;
+       session.version = tonumber(attr.version) or 0;
+       
+       if session.secure == false then
+               session.secure = true;
+       end
        
        if session.version >= 1.0 and not (attr.to and attr.from) then
-               log("warn", (session.to_host or "(unknown)").." failed to specify 'to' or 'from' hostname as per RFC");
+               (session.log or log)("warn", "Remote of stream "..(session.from_host or "(unknown)").."->"..(session.to_host or "(unknown)")
+                       .." failed to specify to (%s) and/or from (%s) hostname as per RFC", tostring(attr.to), tostring(attr.from));
        end
        
        if session.direction == "incoming" then
@@ -342,17 +373,25 @@ function streamopened(session, attr)
        
                session.streamid = uuid_gen();
                (session.log or log)("debug", "incoming s2s received <stream:stream>");
-               send("<?xml version='1.0'?>");
-               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());
                if session.to_host and not hosts[session.to_host] then
                        -- Attempting to connect to a host we don't serve
                        session:close({ condition = "host-unknown"; text = "This host does not serve "..session.to_host });
                        return;
                end
+               send("<?xml version='1.0'?>");
+               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, to=session.from_host, version=(session.version > 0 and "1.0" or nil) }):top_tag());
                if session.version >= 1.0 then
-                       send(st.stanza("stream:features")
-                                       :tag("dialback", { xmlns='urn:xmpp:features:dialback' }):tag("optional"):up():up());
+                       local features = st.stanza("stream:features");
+                       
+                       if session.to_host then
+                               hosts[session.to_host].events.fire_event("s2s-stream-features", { session = session, features = features });
+                       else
+                               (session.log or log)("warn", "No 'to' on stream header from %s means we can't offer any features", session.from_host or "unknown host");
+                       end
+                       
+                       log("debug", "Sending stream features: %s", tostring(features));
+                       send(features);
                end
        elseif session.direction == "outgoing" then
                -- If we are just using the connection for verifying dialback keys, we won't try and auth it
@@ -361,7 +400,7 @@ function streamopened(session, attr)
        
                -- Send unauthed buffer
                -- (stanzas which are fine to send before dialback)
-               -- Note that this is *not* the stanza queue (which 
+               -- Note that this is *not* the stanza queue (which
                -- we can only send if auth succeeds) :)
                local send_buffer = session.send_buffer;
                if send_buffer and #send_buffer > 0 then
@@ -373,13 +412,16 @@ function streamopened(session, attr)
                end
                session.send_buffer = nil;
        
-               if not session.dialback_verifying then
-                       initiate_dialback(session);
-               else
-                       mark_connected(session);
+               -- If server is pre-1.0, don't wait for features, just do dialback
+               if session.version < 1.0 then
+                       if not session.dialback_verifying then
+                               log("debug", "Initiating dialback...");
+                               initiate_dialback(session);
+                       else
+                               mark_connected(session);
+                       end
                end
        end
-
        session.notopen = nil;
 end
 
@@ -399,7 +441,7 @@ function initiate_dialback(session)
 end
 
 function generate_dialback(id, to, from)
-       return sha256_hash(id..to..from..dialback_secret, true);
+       return sha256_hash(id..to..from..hosts[from].dialback_secret, true);
 end
 
 function verify_dialback(id, to, from, key)
@@ -426,6 +468,7 @@ function make_authenticated(session, host)
        return true;
 end
 
+-- Stream is authorised, and ready for normal stanzas
 function mark_connected(session)
        local sendq, send = session.sendq, session.sends2s;
        
@@ -451,12 +494,12 @@ function mark_connected(session)
        end
 end
 
-function destroy_session(session)
+function destroy_session(session, reason)
        (session.log or log)("info", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host));
        
        if session.direction == "outgoing" then
                hosts[session.from_host].s2sout[session.to_host] = nil;
-               bounce_sendq(session);
+               bounce_sendq(session, reason);
        elseif session.direction == "incoming" then
                incoming_s2s[session] = nil;
        end