File

plugins/mod_pubsub/mod_pubsub.lua @ 13652:a08065207ef0

net.server_epoll: Call :shutdown() on TLS sockets when supported Comment from Matthew: This fixes a potential issue where the Prosody process gets blocked on sockets waiting for them to close. Unlike non-TLS sockets, closing a TLS socket sends layer 7 data, and this can cause problems for sockets which are in the process of being cleaned up. This depends on LuaSec changes which are not yet upstream. From Martijn's original email: So first my analysis of luasec. in ssl.c the socket is put into blocking mode right before calling SSL_shutdown() inside meth_destroy(). My best guess to why this is is because meth_destroy is linked to the __close and __gc methods, which can't exactly be called multiple times and luasec does want to make sure that a tls session is shutdown as clean as possible. I can't say I disagree with this reasoning and don't want to change this behaviour. My solution to this without changing the current behaviour is to introduce a shutdown() method. I am aware that this overlaps in a conflicting way with tcp's shutdown method, but it stays close to the OpenSSL name. This method calls SSL_shutdown() in the current (non)blocking mode of the underlying socket and returns a boolean whether or not the shutdown is completed (matching SSL_shutdown()'s 0 or 1 return values), and returns the familiar ssl_ioerror() strings on error with a false for completion. This error can then be used to determine if we have wantread/wantwrite to finalize things. Once meth_shutdown() has been called once a shutdown flag will be set, which indicates to meth_destroy() that the SSL_shutdown() has been handled by the application and it shouldn't be needed to set the socket to blocking mode. I've left the SSL_shutdown() call in the LSEC_STATE_CONNECTED to prevent TOCTOU if the application reaches a timeout for the shutdown code, which might allow SSL_shutdown() to clean up anyway at the last possible moment. Another thing I've changed to luasec is the call to socket_setblocking() right before calling close(2) in socket_destroy() in usocket.c. According to the latest POSIX[0]: Note that the requirement for close() on a socket to block for up to the current linger interval is not conditional on the O_NONBLOCK setting. Which I read to mean that removing O_NONBLOCK on the socket before close doesn't impact the behaviour and only causes noise in system call tracers. I didn't touch the windows bits of this, since I don't do windows. For the prosody side of things I've made the TLS shutdown bits resemble interface:onwritable(), and put it under a combined guard of self._tls and self.conn.shutdown. The self._tls bit is there to prevent getting stuck on this condition, and self.conn.shutdown is there to prevent the code being called by instances where the patched luasec isn't deployed. The destroy() method can be called from various places and is read by me as the "we give up" error path. To accommodate for these unexpected entrypoints I've added a single call to self.conn:shutdown() to prevent the socket being put into blocking mode. I have no expectations that there is any other use here. Same as previous, the self.conn.shutdown check is there to make sure it's not called on unpatched luasec deployments and self._tls is there to make sure we don't call shutdown() on tcp sockets. I wouldn't recommend logging of the conn:shutdown() error inside close(), since a lot of clients simply close the connection before SSL_shutdown() is done.
author Martijn van Duren <martijn@openbsd.org>
date Thu, 06 Feb 2025 15:04:38 +0000
parent 13608:df32fff0963d
line wrap: on
line source

local pubsub = require "prosody.util.pubsub";
local st = require "prosody.util.stanza";
local jid_bare = require "prosody.util.jid".bare;
local new_id = require "prosody.util.id".medium;
local storagemanager = require "prosody.core.storagemanager";
local xtemplate = require "prosody.util.xtemplate";

local xmlns_pubsub = "http://jabber.org/protocol/pubsub";
local xmlns_pubsub_event = "http://jabber.org/protocol/pubsub#event";
local xmlns_pubsub_owner = "http://jabber.org/protocol/pubsub#owner";

local autocreate_on_publish = module:get_option_boolean("autocreate_on_publish", false);
local autocreate_on_subscribe = module:get_option_boolean("autocreate_on_subscribe", false);
local pubsub_disco_name = module:get_option_string("name", "Prosody PubSub Service");
local service_expose_publisher = module:get_option_boolean("expose_publisher")

local service;

local lib_pubsub = module:require "pubsub";

module:depends("disco");
module:add_identity("pubsub", "service", pubsub_disco_name);
module:add_feature("http://jabber.org/protocol/pubsub");

function handle_pubsub_iq(event)
	return lib_pubsub.handle_pubsub_iq(event, service);
end

-- An itemstore supports the following methods:
--   items(): iterator over (id, item)
--   get(id): return item with id
--   set(id, item): set id to item
--   clear(): clear all items
--   resize(n): set new limit and trim oldest items
--   tail(): return the latest item

-- A nodestore supports the following methods:
--   set(node_name, node_data)
--   get(node_name)
--   users(): iterator over (node_name)

local max_max_items = module:get_option_integer("pubsub_max_items", 256, 1);

local function tonumber_max_items(n)
	if n == "max" then
		return max_max_items;
	end
	return tonumber(n);
end

for _, field in ipairs(lib_pubsub.node_config_form) do
	if field.var == "pubsub#max_items" then
		field.range_max = max_max_items;
		break;
	end
end

local node_store = module:open_store(module.name.."_nodes");

local function create_simple_itemstore(node_config, node_name) --> util.cache like object
	local driver = storagemanager.get_driver(module.host, "pubsub_data");
	local archive = driver:open("pubsub_"..node_name, "archive");
	local max_items = tonumber_max_items(node_config["max_items"]);
	return lib_pubsub.archive_itemstore(archive, max_items, nil, node_name);
end

function simple_broadcast(kind, node, jids, item, actor, node_obj, service) --luacheck: ignore 431/service
	if node_obj then
		if node_obj.config["notify_"..kind] == false then
			return;
		end
	end
	if kind == "retract" then
		kind = "items"; -- XEP-0060 signals retraction in an <items> container
	end

	if item then
		item = st.clone(item);
		item.attr.xmlns = nil; -- Clear the pubsub namespace
		if kind == "items" then
			if node_obj and node_obj.config.include_payload == false then
				item:maptags(function () return nil; end);
			end
			local node_expose_publisher = service_expose_publisher;
			if node_expose_publisher == nil and node_obj and node_obj.config.itemreply == "publisher" then
				node_expose_publisher = true;
			end
			if not node_expose_publisher then
				item.attr.publisher = nil;
			elseif not item.attr.publisher and actor ~= true then
				item.attr.publisher = service.config.normalize_jid(actor);
			end
		end
	end

	local id = new_id();
	local msg_type = node_obj and node_obj.config.notification_type or "headline";
	local message = st.message({ from = module.host, type = msg_type, id = id })
		:tag("event", { xmlns = xmlns_pubsub_event })
			:tag(kind, { node = node });

	if item then
		message:add_child(item);
	end

	local summary;
	if item and item.tags[1] then
		local payload = item.tags[1];
		local payload_type = node_obj and node_obj.config.payload_type or payload.attr.xmlns;
		summary = module:fire_event("pubsub-summary/"..payload_type, {
			kind = kind, node = node, jids = jids, actor = actor, item = item, payload = payload,
		});
	end

	for jid, options in pairs(jids) do
		local new_stanza = st.clone(message);
		if summary and type(options) == "table" and options["pubsub#include_body"] then
			new_stanza:body(summary);
		end
		new_stanza.attr.to = jid;
		module:send(new_stanza);
	end
end

function check_node_config(node, actor, new_config) -- luacheck: ignore 212/node 212/actor
	if (tonumber_max_items(new_config["max_items"]) or 1) > max_max_items then
		return false;
	end
	if new_config["access_model"] ~= "whitelist"
	and new_config["access_model"] ~= "open" then
		return false;
	end
	return true;
end

function is_item_stanza(item)
	return st.is_stanza(item) and item.attr.xmlns == xmlns_pubsub and item.name == "item" and #item.tags == 1;
end

-- Compose a textual representation of Atom payloads
local summary_templates = module:get_option("pubsub_summary_templates", {
	["http://www.w3.org/2005/Atom"] = "{@pubsub:title|and{*{@pubsub:title}*\n\n}}{summary|or{{author/name|and{{author/name} posted }}{title}}}";
})

for pubsub_type, template in pairs(summary_templates) do
	module:hook("pubsub-summary/"..pubsub_type, function (event)
		local payload = event.payload;

		local got_config, node_config = service:get_node_config(event.node, true);
		if got_config then
			payload = st.clone(payload);
			payload.attr["xmlns:pubsub"] = xmlns_pubsub;
			payload.attr["pubsub:node"] = event.node;
			payload.attr["pubsub:title"] = node_config.title;
			payload.attr["pubsub:description"] = node_config.description;
		end

		return xtemplate.render(template, payload, tostring);
	end, -1);
end


module:hook("iq/host/"..xmlns_pubsub..":pubsub", handle_pubsub_iq);
module:hook("iq/host/"..xmlns_pubsub_owner..":pubsub", handle_pubsub_iq);

local function add_disco_features_from_service(service) --luacheck: ignore 431/service
	for feature in lib_pubsub.get_feature_set(service) do
		module:add_feature(xmlns_pubsub.."#"..feature);
	end
end

module:hook("host-disco-info-node", function (event)
	return lib_pubsub.handle_disco_info_node(event, service);
end);

module:hook("host-disco-items-node", function (event)
	return lib_pubsub.handle_disco_items_node(event, service);
end);


module:hook("host-disco-items", function (event)
	local stanza, reply = event.stanza, event.reply;
	local ok, ret = service:get_nodes(stanza.attr.from);
	if not ok then
		return;
	end
	for node in pairs(ret) do
		local ok, meta = service:get_node_metadata(node, stanza.attr.from);
		if ok then
			reply:tag("item", { jid = module.host, node = node, name = meta.title }):up();
		end
	end
end);

local admin_aff = module:get_option_enum("default_admin_affiliation", "owner", "publisher", "member", "outcast", "none");

module:default_permission("prosody:admin", ":service-admin");
module:default_permission("prosody:admin", ":create-node");

local function get_affiliation(jid, _, action)
	local bare_jid = jid_bare(jid);
	if bare_jid == module.host then
		-- The host itself (i.e. local modules) is treated as an admin.
		-- Check this first as to avoid sendig a host JID to :may()
		return admin_aff;
	end
	if action == "create" and module:may(":create-node", bare_jid) then
		-- Only one affiliation is allowed to create nodes by default
		return "owner";
	end
	if module:could(":service-admin", bare_jid) then
		return admin_aff;
	end
end

function get_service()
	return service;
end

function set_service(new_service)
	service = new_service;
	service.config.autocreate_on_publish = autocreate_on_publish;
	service.config.autocreate_on_subscribe = autocreate_on_subscribe;
	service.config.expose_publisher = service_expose_publisher;

	service.config.nodestore = node_store;
	service.config.itemstore = create_simple_itemstore;
	service.config.broadcaster = simple_broadcast;
	service.config.itemcheck = is_item_stanza;
	service.config.check_node_config = check_node_config;
	service.config.get_affiliation = get_affiliation;

	module.environment.service = service;
	add_disco_features_from_service(service);
end

function module.save()
	return { service = service };
end

function module.restore(data)
	set_service(data.service);
end

function module.load()
	if module.reloading then return; end

	set_service(pubsub.new({
		autocreate_on_publish = autocreate_on_publish;
		autocreate_on_subscribe = autocreate_on_subscribe;
		expose_publisher = service_expose_publisher;

		node_defaults = {
			["persist_items"] = true;
		};
		max_items = max_max_items;
		nodestore = node_store;
		itemstore = create_simple_itemstore;
		broadcaster = simple_broadcast;
		itemcheck = is_item_stanza;
		check_node_config = check_node_config;
		metadata_subset = {
			"title";
			"description";
			"payload_type";
			"access_model";
			"publish_model";
		};
		get_affiliation = get_affiliation;

		jid = module.host;
		normalize_jid = jid_bare;
	}));
end

local function get_service(service_jid)
	return assert(assert(prosody.hosts[service_jid], "Unknown pubsub service").modules.pubsub, "Not a pubsub service").service;
end

module:require("commands").add_commands(get_service);