--- a/plugins/mod_s2s/mod_s2s.lua	Sat Nov 16 16:45:33 2019 +0100
+++ b/plugins/mod_s2s/mod_s2s.lua	Sat Nov 16 16:52:31 2019 +0100
@@ -27,8 +27,9 @@
 local uuid_gen = require "util.uuid".generate;
 local fire_global_event = prosody.events.fire_event;
 local runner = require "util.async".runner;
-
-local s2sout = module:require("s2sout");
+local connect = require "net.connect".connect;
+local service = require "net.resolvers.service";
+local errors = require "util.error";
 
 local connect_timeout = module:get_option_number("s2s_timeout", 90);
 local stream_close_timeout = module:get_option_number("s2s_close_timeout", 5);
@@ -45,6 +46,8 @@
 
 local runner_callbacks = {};
 
+local listener = {};
+
 local log = module._log;
 
 module:hook("stats-update", function ()
@@ -77,15 +80,28 @@
 			(session.log or log)("error", "Attempting to close the dummy origin of s2s error replies, please report this! Traceback: %s", traceback());
 		end;
 	};
+	-- FIXME Allow for more specific error conditions
+	-- TODO use util.error ?
+	local error_type = "cancel";
+	local condition = "remote-server-not-found";
+	local reason_text;
+	if session.had_stream then -- set when a stream is opened by the remote
+		error_type, condition = "wait", "remote-server-timeout";
+	end
+	if errors.is_err(reason) then
+		error_type, condition, reason_text = reason.type, reason.condition, reason.text;
+	elseif type(reason) == "string" then
+		reason_text = reason;
+	end
 	for i, data in ipairs(sendq) do
 		local reply = data[2];
 		if reply and not(reply.attr.xmlns) and bouncy_stanzas[reply.name] then
 			reply.attr.type = "error";
-			reply:tag("error", {type = "cancel", by = session.from_host})
-				:tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
-			if reason then
+			reply:tag("error", {type = error_type, by = session.from_host})
+				:tag(condition, {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
+			if reason_text then
 				reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"})
-					:text("Server-to-server connection failed: "..reason):up();
+					:text("Server-to-server connection failed: "..reason_text):up();
 			end
 			core_process_stanza(dummy, reply);
 		end
@@ -127,14 +143,9 @@
 		elseif host.type == "local" or host.type == "component" then
 			log("error", "Trying to send a stanza to ourselves??")
 			log("error", "Traceback: %s", traceback());
-			log("error", "Stanza: %s", tostring(stanza));
+			log("error", "Stanza: %s", stanza);
 			return false;
 		else
-			-- FIXME
-			if host.from_host ~= from_host then
-				log("error", "WARNING! This might, possibly, be a bug, but it might not...");
-				log("error", "We are going to send from %s instead of %s", host.from_host, from_host);
-			end
 			if host.sends2s(stanza) then
 				return true;
 			end
@@ -147,17 +158,13 @@
 	local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
 	log("debug", "opening a new outgoing connection for this stanza");
 	local host_session = s2s_new_outgoing(from_host, to_host);
+	host_session.version = 1;
 
 	-- Store in buffer
 	host_session.bounce_sendq = bounce_sendq;
 	host_session.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} };
-	log("debug", "stanza [%s] queued until connection complete", tostring(stanza.name));
-	s2sout.initiate_connection(host_session);
-	if (not host_session.connecting) and (not host_session.conn) then
-		log("warn", "Connection to %s failed already, destroying session...", to_host);
-		s2s_destroy_session(host_session, "Connection failed");
-		return false;
-	end
+	log("debug", "stanza [%s] queued until connection complete", stanza.name);
+	connect(service.new(to_host, "xmpp-server", "tcp", { default_port = 5269 }), listener, nil, { session = host_session });
 	return true;
 end
 
@@ -184,7 +191,10 @@
 			return true;
 		elseif not session.dialback_verifying then
 			session.log("warn", "No SASL EXTERNAL offer and Dialback doesn't seem to be enabled, giving up");
-			session:close();
+			session:close({
+					condition = "unsupported-feature",
+					text = "No viable authentication method offered",
+				});
 			return false;
 		end
 	end, -1);
@@ -203,7 +213,18 @@
 	if session.type == "s2sout" then
 		fire_global_event("s2sout-established", event_data);
 		hosts[from].events.fire_event("s2sout-established", event_data);
+
+		if session.incoming then
+			session.send = function(stanza)
+				return hosts[from].events.fire_event("route/remote", { from_host = from, to_host = to, stanza = stanza });
+			end;
+		end
+
 	else
+		if session.outgoing and not hosts[to].s2sout[from] then
+			session.log("debug", "Setting up to handle route from %s to %s", to, from);
+			hosts[to].s2sout[from] = session; -- luacheck: ignore 122
+		end
 		local host_session = hosts[to];
 		session.send = function(stanza)
 			return host_session.events.fire_event("route/remote", { from_host = to, to_host = from, stanza = stanza });
@@ -223,13 +244,6 @@
 			end
 			session.sendq = nil;
 		end
-
-		if session.resolver then
-			session.resolver._resolver:closeall()
-		end
-		session.resolver = nil;
-		session.ip_hosts = nil;
-		session.srv_hosts = nil;
 	end
 end
 
@@ -251,15 +265,13 @@
 		session.type = "s2sout";
 	elseif session.type == "s2sin_unauthed" then
 		session.type = "s2sin";
-		if host then
-			if not session.hosts[host] then session.hosts[host] = {}; end
-			session.hosts[host].authed = true;
-		end
-	elseif session.type == "s2sin" and host then
+	elseif session.type ~= "s2sin" and session.type ~= "s2sout" then
+		return false;
+	end
+
+	if session.incoming and host then
 		if not session.hosts[host] then session.hosts[host] = {}; end
 		session.hosts[host].authed = true;
-	else
-		return false;
 	end
 	session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host);
 
@@ -301,6 +313,7 @@
 
 function stream_callbacks._streamopened(session, attr)
 	session.version = tonumber(attr.version) or 0;
+	session.had_stream = true; -- Had a stream opened at least once
 
 	-- TODO: Rename session.secure to session.encrypted
 	if session.secure == false then
@@ -314,7 +327,6 @@
 			session.compressed = info.compression;
 		else
 			(session.log or log)("info", "Stream encrypted");
-			session.compressed = sock.compression and sock:compression(); --COMPAT mw/luasec-hg
 		end
 	end
 
@@ -322,7 +334,9 @@
 		-- Send a reply stream header
 
 		-- Validate to/from
-		local to, from = nameprep(attr.to), nameprep(attr.from);
+		local to, from = attr.to, attr.from;
+		if to then to = nameprep(attr.to); end
+		if from then from = nameprep(attr.from); end
 		if not to and attr.to then -- COMPAT: Some servers do not reliably set 'to' (especially on stream restarts)
 			session:close({ condition = "improper-addressing", text = "Invalid 'to' address" });
 			return;
@@ -471,8 +485,6 @@
 	end
 end
 
-local listener = {};
-
 --- Session methods
 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 local function session_close(session, reason, remote_reason)
@@ -595,8 +607,7 @@
 		if data then
 			local ok, err = stream:feed(data);
 			if ok then return; end
-			log("warn", "Received invalid XML: %s", data);
-			log("warn", "Problem was: %s", err);
+			log("debug", "Received invalid XML (%s) %d bytes: %q", err, #data, data:sub(1, 300));
 			session:close("not-well-formed");
 		end
 	end
@@ -672,11 +683,16 @@
 	local session = sessions[conn];
 	if session then
 		sessions[conn] = nil;
+		(session.log or log)("debug", "s2s disconnected: %s->%s (%s)", session.from_host, session.to_host, err or "connection closed");
+		s2s_destroy_session(session, err);
+	end
+end
+
+function listener.onfail(data, err)
+	local session = data and data.session;
+	if session then
 		if err and session.direction == "outgoing" and session.notopen then
 			(session.log or log)("debug", "s2s connection attempt failed: %s", err);
-			if s2sout.attempt_connection(session, err) then
-				return; -- Session lives for now
-			end
 		end
 		(session.log or log)("debug", "s2s disconnected: %s->%s (%s)", session.from_host, session.to_host, err or "connection closed");
 		s2s_destroy_session(session, err);
@@ -700,6 +716,15 @@
 	sessions[conn] = nil;
 end
 
+function listener.onattach(conn, data)
+	local session = data and data.session;
+	if session then
+		session.conn = conn;
+		sessions[conn] = session;
+		initialize_session(session);
+	end
+end
+
 function check_auth_policy(event)
 	local host, session = event.host, event.session;
 	local must_secure = secure_auth;
@@ -723,8 +748,6 @@
 
 module:hook("s2s-check-certificate", check_auth_policy, -1);
 
-s2sout.set_listener(listener);
-
 module:hook("server-stopping", function(event)
 	local reason = event.reason;
 	for _, session in pairs(sessions) do
@@ -739,6 +762,9 @@
 	listener = listener;
 	default_port = 5269;
 	encryption = "starttls";
+	ssl_config = { -- FIXME This is not used atm, see mod_tls
+		verify = { "peer", "client_once", };
+	};
 	multiplex = {
 		pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>";
 	};