-- Copyright (C) 2009 Thilo Cestonaro

-- 

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

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

--

if module:get_host_type() ~= "component" then

	error("proxy65 should be loaded as a component, please see http://prosody.im/doc/components", 0);

end

local jid_split = require "util.jid".split;

local st = require "util.stanza";

local component_register = require "core.componentmanager".register_component;

local component_deregister = require "core.componentmanager".deregister_component;

local configmanager = require "core.configmanager";

local config_get = require "core.configmanager".get;

local connlisteners_register = require "net.connlisteners".register;

local connlisteners_deregister = require "net.connlisteners".deregister;

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

local add_task = require "util.timer".add_task;

local max_dns_depth = config.get("*", "core", "dns_max_depth") or 3;

local dns_timeout = config.get("*", "core", "dns_timeout") or 60;

local replies_cache = {};

local _host = module:get_host();

local _name = "SOCKS5 Bytestreams Service";

local _config = config_get(_host, "core", "proxy65");

local connlistener = {registered=false};

local sessions = {};

local component;

if _config == nil then

	_config = {};

end

if _config.port == nil then

	_config.port = 5000;

end

local function register()

	connlistener = { default_port = _config.port; default_interface = _config.interface };

	connlistener.registered = connlisteners_register('proxy65', connlistener);

	if(connlistener.registered == false) then

		error("Proxy65: Could not establish a connection listener. Check your configuration please.");

	else

		module:add_item("proxy65", {jid=_host, name=_name})

		component = component_register(_host, function(origin, stanza)

			local to_node, to_host, to_resource = jid_split(stanza.attr.to);

			if to_node == nil then

				local type = stanza.attr.type;

				if type == "error" or type == "result" then return; end

				if stanza.name == "iq" and type == "get" then

					local xmlns = stanza.tags[1].attr.xmlns

					if xmlns == "http://jabber.org/protocol/disco#info" then

						origin.send(get_disco_info(stanza));

						return true;

					elseif xmlns == "http://jabber.org/protocol/disco#items" then

						origin.send(get_disco_items(stanza));

						return true;

					elseif xmlns == "http://jabber.org/protocol/bytestreams" and stanza.tags[1].attr.sid ~= nil then

						origin.send(get_stream_host(stanza));

						return true;

					end

				end

			end

			return;

		end);

	end

end

local function getDefaultIP(host)

	local handle;

	handle = adns.lookup(function (reply)

		handle = nil;

		-- COMPAT: This is a compromise for all you CNAME-(ab)users :)

		if not (reply and reply[#reply] and reply[#reply].a) then

			local count = max_dns_depth;

			reply = dns.peek(host, "CNAME", "IN");

			while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do

				module: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[#reply] and reply[#reply].a then

			module:log("debug", "DNS reply for %s gives us %s", host, reply[#reply].a);

			_config.interface = reply[#reply].a

			return register();

		else

			module:log("debug", "DNS lookup failed to get a response for %s", host);

			if host:find(".") ~= nil then

				host = host:gsub("^[^%.]*%.", "");

				if host:find(".") ~= nil then -- still one dot left?

					return getDefaultIP(host);

				end

			end

			error("Proxy65: Could not get an interface to bind to. Please configure one.");

		end

	end, host, "A", "IN");

	-- Set handler for DNS timeout

	add_task(dns_timeout, function ()

		if handle then

			adns.cancel(handle, true);

		end

	end);

	return true;

end

if _config.interface ~= nil then

	register();

else

	getDefaultIP(_host); -- try to DNS lookup module:host()

end

function new_session(conn)

	local w = function(s) conn.write(s:gsub("\n", "\r\n")); end;

	local session = { conn = conn;

			send = function (t) w(tostring(t)); end;

			print = function (t) w("| "..tostring(t).."\n"); end;

			disconnect = function () conn.close(); end;

			};

	return session;

end

function connlistener.listener(conn, data)

	local session = sessions[conn];

	if not session then

		session = new_session(conn);

		sessions[conn] = session;

	end

	if data then

	end

end

function connlistener.disconnect(conn, err)

end

local function get_disco_info(stanza)

	local reply = replies_cache.disco_info;

	if reply == nil then

	 	reply = st.iq({type='result', from=_host}):query("http://jabber.org/protocol/disco#info")

			:tag("identity", {category='proxy', type='bytestreams', name=_name}):up()

			:tag("feature", {var="http://jabber.org/protocol/bytestreams"});

		replies_cache.disco_info = reply;

	end

	reply.attr.id = stanza.attr.id;

	reply.attr.to = stanza.attr.from;

	return reply;

end

local function get_disco_items(stanza)

	local reply = replies_cache.disco_items;

	if reply == nil then

	 	reply = st.iq({type='result', from=_host}):query("http://jabber.org/protocol/disco#items");

		replies_cache.disco_info = reply;

	end

	reply.attr.id = stanza.attr.id;

	reply.attr.to = stanza.attr.from;

	return reply;

end

local function get_stream_host(stanza)

	local reply = replies_cache.stream_host;

	if reply == nil then

		reply = st.iq({type="result", from=_host})

			:query("http://jabber.org/protocol/bytestreams")

			:tag("streamhost", {jid=_host, host=_config.interface, port=_config.port}); -- TODO get the correct data

		replies_cache.stream_host = reply;

	end

	reply.attr.id = stanza.attr.id;

	reply.attr.to = stanza.attr.from;

	reply.tags[1].attr.sid = stanza.tags[1].attr.sid;

	return reply;

end

module.unload = function()

	component_deregister(_host);

	connlisteners_deregister("proxy65");

end