view mod_muc_cloud_notify/mod_muc_cloud_notify.lua @ 5668:ecfd7aece33b

mod_measure_modules: Report module statuses via OpenMetrics Someone in the chat asked about a health check endpoint, which reminded me of mod_http_status, which provides access to module statuses with full details. After that, this idea came about, which seems natural. As noted in the README, it could be used to monitor that critical modules are in fact loaded correctly. As more modules use the status API, the more useful this module and mod_http_status becomes.
author Kim Alvefur <zash@zash.se>
date Fri, 06 Oct 2023 18:34:39 +0200
parents 524a9103fb45
children
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-- XEP-XXX: MUC Push Notifications
-- Copyright (C) 2015-2016 Kim Alvefur
-- Copyright (C) 2017-2018 Thilo Molitor
--
-- This file is MIT/X11 licensed.

local s_match = string.match;
local s_sub = string.sub;
local os_time = os.time;
local next = next;
local st = require"util.stanza";
local jid = require"util.jid";
local dataform = require"util.dataforms".new;
local hashes = require"util.hashes";

local xmlns_push = "urn:xmpp:push:0";

-- configuration
local include_body = module:get_option_boolean("push_notification_with_body", false);
local include_sender = module:get_option_boolean("push_notification_with_sender", false);
local max_push_errors = module:get_option_number("push_max_errors", 16);
local max_push_devices = module:get_option_number("push_max_devices", 5);
local dummy_body = module:get_option_string("push_notification_important_body", "New Message!");

local host_sessions = prosody.hosts[module.host].sessions;
local push_errors = {};
local id2node = {};

module:depends("muc");

-- ordered table iterator, allow to iterate on the natural order of the keys of a table,
-- see http://lua-users.org/wiki/SortedIteration
local function __genOrderedIndex( t )
	local orderedIndex = {}
	for key in pairs(t) do
		table.insert( orderedIndex, key )
	end
	-- sort in reverse order (newest one first)
	table.sort( orderedIndex, function(a, b)
		if a == nil or t[a] == nil or b == nil or t[b] == nil then return false end
		-- only one timestamp given, this is the newer one
		if t[a].timestamp ~= nil and t[b].timestamp == nil then return true end
		if t[a].timestamp == nil and t[b].timestamp ~= nil then return false end
		-- both timestamps given, sort normally
		if t[a].timestamp ~= nil and t[b].timestamp ~= nil then return t[a].timestamp > t[b].timestamp end
		return false	-- normally not reached
	end)
	return orderedIndex
end
local function orderedNext(t, state)
	-- Equivalent of the next function, but returns the keys in timestamp
	-- order. We use a temporary ordered key table that is stored in the
	-- table being iterated.

	local key = nil
	--print("orderedNext: state = "..tostring(state) )
	if state == nil then
		-- the first time, generate the index
		t.__orderedIndex = __genOrderedIndex( t )
		key = t.__orderedIndex[1]
	else
		-- fetch the next value
		for i = 1, #t.__orderedIndex do
			if t.__orderedIndex[i] == state then
				key = t.__orderedIndex[i+1]
			end
		end
	end

	if key then
		return key, t[key]
	end

	-- no more value to return, cleanup
	t.__orderedIndex = nil
	return
end
local function orderedPairs(t)
	-- Equivalent of the pairs() function on tables. Allows to iterate
	-- in order
	return orderedNext, t, nil
end

-- small helper function to return new table with only "maximum" elements containing only the newest entries
local function reduce_table(table, maximum)
	local count = 0;
	local result = {};
	for key, value in orderedPairs(table) do
		count = count + 1;
		if count > maximum then break end
		result[key] = value;
	end
	return result;
end

-- For keeping state across reloads while caching reads
local push_store = (function()
	local store = module:open_store();
	local push_services = {};
	local api = {};
	function api:get(user)
		if not push_services[user] then
			local err;
			push_services[user], err = store:get(user);
			if not push_services[user] and err then
				module:log("warn", "Error reading push notification storage for user '%s': %s", user, tostring(err));
				push_services[user] = {};
				return push_services[user], false;
			end
		end
		if not push_services[user] then push_services[user] = {} end
		return push_services[user], true;
	end
	function api:set(user, data)
		push_services[user] = reduce_table(data, max_push_devices);
		local ok, err = store:set(user, push_services[user]);
		if not ok then
			module:log("error", "Error writing push notification storage for user '%s': %s", user, tostring(err));
			return false;
		end
		return true;
	end
	function api:set_identifier(user, push_identifier, data)
		local services = self:get(user);
		services[push_identifier] = data;
		return self:set(user, services);
	end
	return api;
end)();


-- Forward declarations, as both functions need to reference each other
local handle_push_success, handle_push_error;

function handle_push_error(event)
	local stanza = event.stanza;
	local error_type, condition = stanza:get_error();
	local node = id2node[stanza.attr.id];
	if node == nil then return false; end		-- unknown stanza? Ignore for now!
	local from = stanza.attr.from;
	local user_push_services = push_store:get(node);
	local changed = false;
	
	for push_identifier, _ in pairs(user_push_services) do
		local stanza_id = hashes.sha256(push_identifier, true);
		if stanza_id == stanza.attr.id then
			if user_push_services[push_identifier] and user_push_services[push_identifier].jid == from and error_type ~= "wait" then
				push_errors[push_identifier] = push_errors[push_identifier] + 1;
				module:log("info", "Got error of type '%s' (%s) for identifier '%s': "
					.."error count for this identifier is now at %s", error_type, condition, push_identifier,
					tostring(push_errors[push_identifier]));
				if push_errors[push_identifier] >= max_push_errors then
					module:log("warn", "Disabling push notifications for identifier '%s'", push_identifier);
					-- remove push settings from sessions
					if host_sessions[node] then
						for _, session in pairs(host_sessions[node].sessions) do
							if session.push_identifier == push_identifier then
								session.push_identifier = nil;
								session.push_settings = nil;
								session.first_hibernated_push = nil;
							end
						end
					end
					-- save changed global config
					changed = true;
					user_push_services[push_identifier] = nil
					push_errors[push_identifier] = nil;
					-- unhook iq handlers for this identifier (if possible)
					if module.unhook then
						module:unhook("iq-error/host/"..stanza_id, handle_push_error);
						module:unhook("iq-result/host/"..stanza_id, handle_push_success);
						id2node[stanza_id] = nil;
					end
				end
			elseif user_push_services[push_identifier] and user_push_services[push_identifier].jid == from and error_type == "wait" then
				module:log("debug", "Got error of type '%s' (%s) for identifier '%s': "
					.."NOT increasing error count for this identifier", error_type, condition, push_identifier);
			end
		end
	end
	if changed then
		push_store:set(node, user_push_services);
	end
	return true;
end

function handle_push_success(event)
	local stanza = event.stanza;
	local node = id2node[stanza.attr.id];
	if node == nil then return false; end		-- unknown stanza? Ignore for now!
	local from = stanza.attr.from;
	local user_push_services = push_store:get(node);
	
	for push_identifier, _ in pairs(user_push_services) do
		if hashes.sha256(push_identifier, true) == stanza.attr.id then
			if user_push_services[push_identifier] and user_push_services[push_identifier].jid == from and push_errors[push_identifier] > 0 then
				push_errors[push_identifier] = 0;
				module:log("debug", "Push succeeded, error count for identifier '%s' is now at %s again", push_identifier, tostring(push_errors[push_identifier]));
			end
		end
	end
	return true;
end

-- http://xmpp.org/extensions/xep-0357.html#disco
local function account_dico_info(event)
	(event.reply or event.stanza):tag("feature", {var=xmlns_push}):up();
end
module:hook("account-disco-info", account_dico_info);

-- http://xmpp.org/extensions/xep-0357.html#enabling
local function push_enable(event)
	local origin, stanza = event.origin, event.stanza;
	local enable = stanza.tags[1];
	origin.log("debug", "Attempting to enable push notifications");
	-- MUST contain a 'jid' attribute of the XMPP Push Service being enabled
	local push_jid = enable.attr.jid;
	-- SHOULD contain a 'node' attribute
	local push_node = enable.attr.node;
	-- CAN contain a 'include_payload' attribute
	local include_payload = enable.attr.include_payload;
	if not push_jid then
		origin.log("debug", "MUC Push notification enable request missing the 'jid' field");
		origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing jid"));
		return true;
	end
	local publish_options = enable:get_child("x", "jabber:x:data");
	if not publish_options then
		-- Could be intentional
		origin.log("debug", "No publish options in request");
	end
	local push_identifier = push_jid .. "<" .. (push_node or "");
	local push_service = {
		jid = push_jid;
		node = push_node;
		include_payload = include_payload;
		options = publish_options and st.preserialize(publish_options);
		timestamp = os_time();
	};
	local ok = push_store:set_identifier(origin.username.."@"..origin.host, push_identifier, push_service);
	if not ok then
		origin.send(st.error_reply(stanza, "wait", "internal-server-error"));
	else
		origin.push_identifier = push_identifier;
		origin.push_settings = push_service;
		origin.first_hibernated_push = nil;
		origin.log("info", "MUC Push notifications enabled for %s by %s (%s)",
			 tostring(stanza.attr.to),
			 tostring(stanza.attr.from),
			 tostring(origin.push_identifier)
			);
		origin.send(st.reply(stanza));
	end
	return true;
end
module:hook("iq-set/host/"..xmlns_push..":enable", push_enable);


-- http://xmpp.org/extensions/xep-0357.html#disabling
local function push_disable(event)
	local origin, stanza = event.origin, event.stanza;
	local push_jid = stanza.tags[1].attr.jid; -- MUST include a 'jid' attribute
	local push_node = stanza.tags[1].attr.node; -- A 'node' attribute MAY be included
	if not push_jid then
		origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing jid"));
		return true;
	end
	local user_push_services = push_store:get(origin.username);
	for key, push_info in pairs(user_push_services) do
		if push_info.jid == push_jid and (not push_node or push_info.node == push_node) then
			origin.log("info", "Push notifications disabled (%s)", tostring(key));
			if origin.push_identifier == key then
				origin.push_identifier = nil;
				origin.push_settings = nil;
				origin.first_hibernated_push = nil;
			end
			user_push_services[key] = nil;
			push_errors[key] = nil;
			if module.unhook then
				module:unhook("iq-error/host/"..key, handle_push_error);
				module:unhook("iq-result/host/"..key, handle_push_success);
				id2node[key] = nil;
			end
		end
	end
	local ok = push_store:set(origin.username, user_push_services);
	if not ok then
		origin.send(st.error_reply(stanza, "wait", "internal-server-error"));
	else
		origin.send(st.reply(stanza));
	end
	return true;
end
module:hook("iq-set/host/"..xmlns_push..":disable", push_disable);

-- Patched version of util.stanza:find() that supports giving stanza names
-- without their namespace, allowing for every namespace.
local function find(self, path)
	local pos = 1;
	local len = #path + 1;

	repeat
		local xmlns, name, text;
		local char = s_sub(path, pos, pos);
		if char == "@" then
			return self.attr[s_sub(path, pos + 1)];
		elseif char == "{" then
			xmlns, pos = s_match(path, "^([^}]+)}()", pos + 1);
		end
		name, text, pos = s_match(path, "^([^@/#]*)([/#]?)()", pos);
		name = name ~= "" and name or nil;
		if pos == len then
			if text == "#" then
				local child = xmlns ~= nil and self:get_child(name, xmlns) or self:child_with_name(name);
				return child and child:get_text() or nil;
			end
			return xmlns ~= nil and self:get_child(name, xmlns) or self:child_with_name(name);
		end
		self = xmlns ~= nil and self:get_child(name, xmlns) or self:child_with_name(name);
	until not self
	return nil;
end

-- is this push a high priority one (this is needed for ios apps not using voip pushes)
local function is_important(stanza)
	local st_name = stanza and stanza.name or nil;
	if not st_name then return false; end	-- nonzas are never important here
	if st_name == "presence" then
		return false;						-- same for presences
	elseif st_name == "message" then
		-- unpack carbon copies
		local stanza_direction = "in";
		local carbon;
		local st_type;
		-- support carbon copied message stanzas having an arbitrary message-namespace or no message-namespace at all
		if not carbon then carbon = find(stanza, "{urn:xmpp:carbons:2}/forwarded/message"); end
		if not carbon then carbon = find(stanza, "{urn:xmpp:carbons:1}/forwarded/message"); end
		stanza_direction = carbon and stanza:child_with_name("sent") and "out" or "in";
		if carbon then stanza = carbon; end
		st_type = stanza.attr.type;
		
		-- headline message are always not important
		if st_type == "headline" then return false; end
		
		-- carbon copied outgoing messages are not important
		if carbon and stanza_direction == "out" then return false; end
		
		-- We can't check for body contents in encrypted messages, so let's treat them as important
		-- Some clients don't even set a body or an empty body for encrypted messages
		
		-- check omemo https://xmpp.org/extensions/inbox/omemo.html
		if stanza:get_child("encrypted", "eu.siacs.conversations.axolotl") or stanza:get_child("encrypted", "urn:xmpp:omemo:0") then return true; end
		
		-- check xep27 pgp https://xmpp.org/extensions/xep-0027.html
		if stanza:get_child("x", "jabber:x:encrypted") then return true; end
		
		-- check xep373 pgp (OX) https://xmpp.org/extensions/xep-0373.html
		if stanza:get_child("openpgp", "urn:xmpp:openpgp:0") then return true; end
		
		local body = stanza:get_child_text("body");
		if st_type == "groupchat" and stanza:get_child_text("subject") then return false; end		-- groupchat subjects are not important here
		return body ~= nil and body ~= "";			-- empty bodies are not important
	end
	return false;		-- this stanza wasn't one of the above cases --> it is not important, too
end

local push_form = dataform {
	{ name = "FORM_TYPE"; type = "hidden"; value = "urn:xmpp:push:summary"; };
	{ name = "message-count"; type = "text-single"; };
	{ name = "pending-subscription-count"; type = "text-single"; };
	{ name = "last-message-sender"; type = "jid-single"; };
	{ name = "last-message-body"; type = "text-single"; };
};

-- http://xmpp.org/extensions/xep-0357.html#publishing
local function handle_notify_request(stanza, node, user_push_services, log_push_decline)
	local pushes = 0;
	if not user_push_services or next(user_push_services) == nil then return pushes end

	-- XXX: customized
	local body = stanza:get_child_text("body");
	if not body then
		return pushes;
	end
	
	for push_identifier, push_info in pairs(user_push_services) do
		local send_push = true;		-- only send push to this node when not already done for this stanza or if no stanza is given at all
		if stanza then
			if not stanza._push_notify then stanza._push_notify = {}; end
			if stanza._push_notify[push_identifier] then
				if log_push_decline then
					module:log("debug", "Already sent push notification for %s@%s to %s (%s)", node, module.host, push_info.jid, tostring(push_info.node));
				end
				send_push = false;
			end
			stanza._push_notify[push_identifier] = true;
		end
		
		if send_push then
			-- construct push stanza
			local stanza_id = hashes.sha256(push_identifier, true);
			local push_publish = st.iq({ to = push_info.jid, from = module.host, type = "set", id = stanza_id })
				:tag("pubsub", { xmlns = "http://jabber.org/protocol/pubsub" })
					:tag("publish", { node = push_info.node })
						:tag("item")
							:tag("notification", { xmlns = xmlns_push });
			local form_data = {
				-- hardcode to 1 because other numbers are just meaningless (the XEP does not specify *what exactly* to count)
				["message-count"] = "1";
			};
			if stanza and include_sender then
				form_data["last-message-sender"] = stanza.attr.from;
			end
			if stanza and include_body then
				form_data["last-message-body"] = stanza:get_child_text("body");
			elseif stanza and dummy_body and is_important(stanza) then
				form_data["last-message-body"] = tostring(dummy_body);
			end
			push_publish:add_child(push_form:form(form_data));
			push_publish:up(); -- / notification
			push_publish:up(); -- / publish
			push_publish:up(); -- / pubsub
			if push_info.options then
				push_publish:tag("publish-options"):add_child(st.deserialize(push_info.options));
			end
			-- send out push
			module:log("debug", "Sending%s push notification for %s@%s to %s (%s)", form_data["last-message-body"] and " important" or "", node, module.host, push_info.jid, tostring(push_info.node));
			-- module:log("debug", "PUSH STANZA: %s", tostring(push_publish));
			-- handle push errors for this node
			if push_errors[push_identifier] == nil then
				push_errors[push_identifier] = 0;
				module:hook("iq-error/host/"..stanza_id, handle_push_error);
				module:hook("iq-result/host/"..stanza_id, handle_push_success);
				id2node[stanza_id] = node;
			end
			module:send(push_publish);
			pushes = pushes + 1;
		end
	end
	return pushes;
end

local function extract_reference(text, i, j)
        -- COMPAT w/ pre-Lua 5.3
        local c, pos, p1 = 0, 0, nil;
        for char in text:gmatch("([%z\1-\127\194-\244][\128-\191]*)") do
                c, pos = c + 1, pos + #char;
                if not p1 and i < c then
                        p1 = pos;
                end
                if c == j then
                        return text:sub(p1, pos);
                end
        end
end

-- archive message added
local function archive_message_added(event)
	-- event is: { origin = origin, stanza = stanza, for_user = store_user, id = id }
	-- only notify for new mam messages when at least one device is online
	local room = event.room;
	local stanza = event.stanza;
	local body = stanza:get_child_text('body');

	for reference in stanza:childtags("reference", "urn:xmpp:reference:0") do
		local ref_begin, ref_end = tonumber(reference.attr['begin']), tonumber(reference.attr['end']);
		if reference.attr['type'] == 'mention' and ref_begin and ref_end then
			local nick = extract_reference(body, ref_begin, ref_end);
			local jid = room:get_registered_jid(nick);

			if room._occupants[room.jid..'/'..nick] then
				-- We only notify for members not currently in the room
				module:log("debug", "Not notifying %s, because he's currently in the room", jid);
			else
				-- We only need to notify once, even when there are multiple mentions.
				local user_push_services = push_store:get(jid);
				handle_notify_request(event.stanza, jid, user_push_services, true);
				return
			end
		end
	end
end

module:hook("muc-add-history", archive_message_added);

local function send_ping(event)
	local user = event.user;
	local user_push_services = push_store:get(user);
	local push_services = event.push_services or user_push_services;
	handle_notify_request(nil, user, push_services, true);
end
-- can be used by other modules to ping one or more (or all) push endpoints
module:hook("cloud-notify-ping", send_ping);

module:log("info", "Module loaded");
function module.unload()
	if module.unhook then
		module:unhook("account-disco-info", account_dico_info);
		module:unhook("iq-set/host/"..xmlns_push..":enable", push_enable);
		module:unhook("iq-set/host/"..xmlns_push..":disable", push_disable);

		module:unhook("muc-add-history", archive_message_added);
		module:unhook("cloud-notify-ping", send_ping);

		for push_identifier, _ in pairs(push_errors) do
			local stanza_id = hashes.sha256(push_identifier, true);
			module:unhook("iq-error/host/"..stanza_id, handle_push_error);
			module:unhook("iq-result/host/"..stanza_id, handle_push_success);
			id2node[stanza_id] = nil;
		end
	end

	module:log("info", "Module unloaded");
end