-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- 

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local hosts = hosts;

local core_process_stanza = function(a, b) core_process_stanza(a, b); end

local format = string.format;

local t_insert, t_sort = table.insert, table.sort;

local get_traceback = debug.traceback;

local tostring, pairs, ipairs, getmetatable, newproxy, type, error, tonumber, setmetatable

    = tostring, pairs, ipairs, getmetatable, newproxy, type, error, tonumber, setmetatable;

local initialize_filters = require "util.filters".initialize;

local wrapclient = require "net.server".wrapclient;

local st = require "stanza";

local stanza = st.stanza;

local nameprep = require "util.encodings".stringprep.nameprep;

local cert_verify_identity = require "util.x509".verify_identity;

local new_ip = require "util.ip".new_ip;

local rfc3484_dest = require "util.rfc3484".destination;

local fire_event = prosody.events.fire_event;

local uuid_gen = require "util.uuid".generate;

local logger_init = require "util.logger".init;

local log = logger_init("s2smanager");

local sha256_hash = require "util.hashes".sha256;

local adns, dns = require "net.adns", require "net.dns";

local config = require "core.configmanager";

local dns_timeout = config.get("*", "core", "dns_timeout") or 15;

local cfg_sources = config.get("*", "core", "s2s_interface")

	or config.get("*", "core", "interface");

local sources;

--FIXME: s2sout should create its own resolver w/ timeout

dns.settimeout(dns_timeout);

local prosody = _G.prosody;

incoming_s2s = {};

prosody.incoming_s2s = incoming_s2s;

local incoming_s2s = incoming_s2s;

module "s2smanager"

local open_sessions = 0;

function new_incoming(conn)

	local session = { conn = conn, type = "s2sin_unauthed", direction = "incoming", hosts = {} };

	if true then

		session.trace = newproxy(true);

		getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; end;

	end

	open_sessions = open_sessions + 1;

	session.log = logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));

	incoming_s2s[session] = true;

	return session;

end

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" };

	hosts[from_host].s2sout[to_host] = host_session;

	local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$");

	host_session.log = logger_init(conn_name);

	return host_session;

end

function make_authenticated(session, host)

	if not session.secure then

		local local_host = session.direction == "incoming" and session.to_host or session.from_host;

		if config.get(local_host, "core", "s2s_require_encryption") then

			session:close({

				condition = "policy-violation",

				text = "Encrypted server-to-server communication is required but was not "

				       ..((session.direction == "outgoing" and "offered") or "used")

			});

		end

	end

	if session.type == "s2sout_unauthed" then

		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

		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 or "(unknown)", session.to_host or "(unknown)", host);

	mark_connected(session);

	return true;

end

-- Stream is authorised, and ready for normal stanzas

function mark_connected(session)

	local sendq, send = session.sendq, session.sends2s;

	local from, to = session.from_host, session.to_host;

	session.log("info", session.direction.." s2s connection "..from.."->"..to.." complete");

	local event_data = { session = session };

	if session.type == "s2sout" then

		prosody.events.fire_event("s2sout-established", event_data);

		hosts[session.from_host].events.fire_event("s2sout-established", event_data);

	else

		prosody.events.fire_event("s2sin-established", event_data);

		hosts[session.to_host].events.fire_event("s2sin-established", event_data);

	end

	if session.direction == "outgoing" then

		if sendq then

			session.log("debug", "sending "..#sendq.." queued stanzas across new outgoing connection to "..session.to_host);

			for i, data in ipairs(sendq) do

				send(data[1]);

				sendq[i] = nil;

			end

			session.sendq = nil;

		end

		session.ip_hosts = nil;

		session.srv_hosts = nil;

	end

end

local resting_session = { -- Resting, not dead

		destroyed = true;

		type = "s2s_destroyed";

		open_stream = function (session)

			session.log("debug", "Attempt to open stream on resting session");

		end;

		close = function (session)

			session.log("debug", "Attempt to close already-closed session");

		end;

		filter = function (type, data) return data; end;

	}; resting_session.__index = resting_session;

function retire_session(session, reason)

	local log = session.log or log;

	for k in pairs(session) do

		if k ~= "trace" and k ~= "log" and k ~= "id" then

			session[k] = nil;

		end

	end

	session.destruction_reason = reason;

	function session.send(data) log("debug", "Discarding data sent to resting session: %s", tostring(data)); end

	function session.data(data) log("debug", "Discarding data received from resting session: %s", tostring(data)); end

	return setmetatable(session, resting_session);

end

function destroy_session(session, reason)

	if session.destroyed then return; end

	(session.log or log)("debug", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host)..(reason and (": "..reason) or ""));

	if session.direction == "outgoing" then

		hosts[session.from_host].s2sout[session.to_host] = nil;

		session:bounce_sendq(reason);

	elseif session.direction == "incoming" then

		incoming_s2s[session] = nil;

	end

	local event_data = { session = session, reason = reason };

	if session.type == "s2sout" then

		prosody.events.fire_event("s2sout-destroyed", event_data);

		if hosts[session.from_host] then

			hosts[session.from_host].events.fire_event("s2sout-destroyed", event_data);

		end

	elseif session.type == "s2sin" then

		prosody.events.fire_event("s2sin-destroyed", event_data);

		if hosts[session.to_host] then

			hosts[session.to_host].events.fire_event("s2sin-destroyed", event_data);

		end

	end

	retire_session(session, reason); -- Clean session until it is GC'd

	return true;

end

return _M;