-- 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 log = require "util.logger".init("stanzarouter")

local hosts = _G.prosody.hosts;

local tostring = tostring;

local st = require "util.stanza";

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

local jid_prepped_split = require "util.jid".prepped_split;

local full_sessions = _G.prosody.full_sessions;

local bare_sessions = _G.prosody.bare_sessions;

local core_post_stanza, core_process_stanza, core_route_stanza;

local valid_stanzas = { message = true, presence = true, iq = true };

local function handle_unhandled_stanza(host, origin, stanza) --luacheck: ignore 212/host

	local name, xmlns, origin_type = stanza.name, stanza.attr.xmlns or "jabber:client", origin.type;

	if xmlns == "jabber:client" and valid_stanzas[name] then

		-- A normal stanza

		local st_type = stanza.attr.type;

		if st_type == "error" or (name == "iq" and st_type == "result") then

			if st_type == "error" then

				local err_type, err_condition, err_message = stanza:get_error();

				log("debug", "Discarding unhandled error %s (%s, %s) from %s: %s",

					name, err_type, err_condition or "unknown condition", origin_type, stanza:top_tag());

			else

				log("debug", "Discarding %s from %s of type: %s", name, origin_type, st_type or '<nil>');

			end

			return;

		end

		if name == "iq" and (st_type == "get" or st_type == "set") and stanza.tags[1] then

			xmlns = stanza.tags[1].attr.xmlns or "jabber:client";

		end

		log("debug", "Unhandled %s stanza: %s; xmlns=%s", origin_type, name, xmlns);

		if origin.send then

			origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));

		end

	else

		log("warn", "Unhandled %s stream element or stanza: %s; xmlns=%s: %s",

			origin_type, name, xmlns, tostring(stanza)); -- we didn't handle it

		origin:close("unsupported-stanza-type");

	end

end

local iq_types = { set=true, get=true, result=true, error=true };

function core_process_stanza(origin, stanza)

	(origin.log or log)("debug", "Received[%s]: %s", origin.type, stanza:top_tag())

	if origin.type == "c2s" and not stanza.attr.xmlns then

		local name, st_type = stanza.name, stanza.attr.type;

		if st_type == "error" and #stanza.tags == 0 then

			return handle_unhandled_stanza(origin.host, origin, stanza);

		end

		if name == "iq" then

			if not iq_types[st_type] then

				origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid IQ type"));

				return;

			elseif not stanza.attr.id then

				origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing required 'id' attribute"));

				return;

			elseif (st_type == "set" or st_type == "get") and (#stanza.tags ~= 1) then

				origin.send(st.error_reply(stanza, "modify", "bad-request", "Incorrect number of children for IQ stanza"));

				return;

			end

		end

		-- TODO also, stanzas should be returned to their original state before the function ends

		stanza.attr.from = origin.full_jid;

	end

	local to, xmlns = stanza.attr.to, stanza.attr.xmlns;

	local from = stanza.attr.from;

	local node, host, resource;

	local from_node, from_host, from_resource;

	local to_bare, from_bare;

	if to then

		if full_sessions[to] or bare_sessions[to] or hosts[to] then

			node, host = jid_split(to); -- TODO only the host is needed, optimize

		else

			node, host, resource = jid_prepped_split(to);

			if not host then

				log("warn", "Received stanza with invalid destination JID: %s", to);

				if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

					origin.send(st.error_reply(stanza, "modify", "jid-malformed", "The destination address is invalid: "..to));

				end

				return;

			end

			to_bare = node and (node.."@"..host) or host; -- bare JID

			if resource then to = to_bare.."/"..resource; else to = to_bare; end

			stanza.attr.to = to;

		end

	end

	if from and not origin.full_jid then

		-- We only stamp the 'from' on c2s stanzas, so we still need to check validity

		from_node, from_host, from_resource = jid_prepped_split(from);

		if not from_host then

			log("warn", "Received stanza with invalid source JID: %s", from);

			if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

				origin.send(st.error_reply(stanza, "modify", "jid-malformed", "The source address is invalid: "..from));

			end

			return;

		end

		from_bare = from_node and (from_node.."@"..from_host) or from_host; -- bare JID

		if from_resource then from = from_bare.."/"..from_resource; else from = from_bare; end

		stanza.attr.from = from;

	end

	if (origin.type == "s2sin" or origin.type == "c2s" or origin.type == "component") and xmlns == nil then

		if origin.type == "s2sin" and not origin.dummy then

			local host_status = origin.hosts[from_host];

			if not host_status or not host_status.authed then -- remote server trying to impersonate some other server?

				log("warn", "Received a stanza claiming to be from %s, over a stream authed for %s!", from_host, origin.from_host);

				origin:close("not-authorized");

				return;

			elseif not hosts[host] then

				log("warn", "Remote server %s sent us a stanza for %s, closing stream", origin.from_host, host);

				origin:close("host-unknown");

				return;

			end

		end

		core_post_stanza(origin, stanza, origin.full_jid);

	else

		local h = hosts[stanza.attr.to or origin.host or origin.to_host];

		if h then

			local event;

			if xmlns == nil then

				if stanza.name == "iq" and (stanza.attr.type == "set" or stanza.attr.type == "get")

					and stanza.tags[1] and stanza.tags[1].attr.xmlns then

					event = "stanza/iq/"..stanza.tags[1].attr.xmlns..":"..stanza.tags[1].name;

				else

					event = "stanza/"..stanza.name;

				end

			else

				event = "stanza/"..xmlns..":"..stanza.name;

			end

			if h.events.fire_event(event, {origin = origin, stanza = stanza}) then return; end

		end

		if host and not hosts[host] then host = nil; end -- COMPAT: workaround for a Pidgin bug which sets 'to' to the SRV result

		handle_unhandled_stanza(host or origin.host or origin.to_host, origin, stanza);

	end

end

function core_post_stanza(origin, stanza, preevents)

	local to = stanza.attr.to;

	local node, host, resource = jid_split(to);

	local to_bare = node and (node.."@"..host) or host; -- bare JID

	local to_type, to_self;

	if node then

		if resource then

			to_type = '/full';

		else

			to_type = '/bare';

			if node == origin.username and host == origin.host then

				stanza.attr.to = nil;

				to_self = true;

			end

		end

	else

		if host then

			to_type = '/host';

		else

			to_type = '/bare';

			to_self = true;

		end

	end

	local event_data = {origin=origin, stanza=stanza};

	if preevents then -- c2s connection

		if hosts[origin.host].events.fire_event('pre-'..stanza.name..to_type, event_data) then return; end -- do preprocessing

	end

	local h = hosts[to_bare] or hosts[host or origin.host];

	if h then

		if h.events.fire_event(stanza.name..to_type, event_data) then return; end -- do processing

		if to_self and h.events.fire_event(stanza.name..'/self', event_data) then return; end -- do processing

		handle_unhandled_stanza(h.host, origin, stanza);

	else

		core_route_stanza(origin, stanza);

	end

end

function core_route_stanza(origin, stanza)

	local node, host, resource = jid_split(stanza.attr.to);

	local from_node, from_host, from_resource = jid_split(stanza.attr.from);

	-- Auto-detect origin if not specified

	origin = origin or hosts[from_host];

	if not origin then return false; end

	if hosts[host] then

		-- old stanza routing code removed

		core_post_stanza(origin, stanza);

	else

		local host_session = hosts[from_host];

		if not host_session then

			log("error", "No hosts[from_host] (please report): %s", tostring(stanza));

		else

			local xmlns = stanza.attr.xmlns;

			stanza.attr.xmlns = nil;

			local routed = host_session.events.fire_event("route/remote", {

				origin = origin, stanza = stanza, from_host = from_host, to_host = host });

			stanza.attr.xmlns = xmlns; -- reset

			if not routed then

				log("debug", "Could not route stanza to remote");

				if stanza.attr.type == "error" or (stanza.name == "iq" and stanza.attr.type == "result") then return; end

				core_route_stanza(host_session, st.error_reply(stanza, "cancel", "not-allowed",

					"Communication with remote domains is not enabled"));

			end

		end

	end

end

--luacheck: ignore 122/prosody

prosody.core_process_stanza = core_process_stanza;

prosody.core_post_stanza = core_post_stanza;

prosody.core_route_stanza = core_route_stanza;