view mod_csi_battery_saver/mod_csi_battery_saver.lua @ 5593:6d0574bfbf5d

mod_client_management: Include software version in table (when known) Showing software versions could be useful for statistical reasons, e.g. determining how quickly (or not) users upgrade, but most importantly for revoking vulnerable clients versions in case of a security issue.
author Kim Alvefur <zash@zash.se>
date Thu, 13 Jul 2023 23:26:02 +0200
parents 889e1695e935
children f6a2602129c8
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-- Copyright (C) 2016 Kim Alvefur
-- Copyright (C) 2017 Thilo Molitor
--

local filter_muc = module:get_option_boolean("csi_battery_saver_filter_muc", false);
local queue_size = module:get_option_number("csi_battery_saver_queue_size", 256);

module:depends"csi"
if filter_muc then module:depends"track_muc_joins"; end		-- only depend on this module if we actually use it
local s_match = string.match;
local s_sub = string.sub;
local jid = require "util.jid";
local new_queue = require "util.queue".new;
local datetime = require "util.datetime";
local st = require "util.stanza";

local xmlns_delay = "urn:xmpp:delay";

-- a log id for this module instance
local id = s_sub(require "util.hashes".sha256(datetime.datetime(), true), 1, 4);


-- Returns a forwarded message, and either "in" or "out" depending on the direction
-- Returns nil if the message is not a carbon
local function extract_carbon(stanza)
	local carbon = stanza:child_with_ns("urn:xmpp:carbons:2") or stanza:child_with_ns("urn:xmpp:carbons:1");
	if not carbon then return; end
	local direction = carbon.name == "sent" and "out" or "in";
	local forward = carbon:get_child("forwarded", "urn:xmpp:forward:0");
	local message = forward and forward:child_with_name("message") or nil;
	if not message then return; end
	return message, direction;
end

local function new_pump(session, output, ...)
	-- luacheck: ignore 212/self
	local q = new_queue(...);
	local flush = true;
	function q:pause()
		flush = false;
	end
	function q:resume()
		flush = true;
		return q:flush();
	end
	local push = q.push;
	function q:push(item)
		local ok = push(self, item);
		if not ok then
			session.log("debug", "mod_csi_battery_saver(%s): Queue full (%d items), forcing flush...", id, q:count());
			q:flush();
			output(item, self);
		elseif flush then
			return q:flush();
		end
		return true;
	end
	function q:flush(alternative_output)
		local out = alternative_output or output;
		local item = self:pop();
		while item do
			out(item, self);
			item = self:pop();
		end
		return true;
	end
	return q;
end

local function is_stamp_needed(stanza, session)
	local st_name = stanza and stanza.name or nil;
	if st_name == "presence" then
		return true;
	elseif st_name == "message" then
		if stanza:get_child("delay", xmlns_delay) then return false; end
		if stanza.attr.type == "chat" or stanza.attr.type == "groupchat" then return true; end
	end
	return false;
end

local function add_stamp(stanza, session)
	local bare_jid = jid.bare(session.full_jid or session.host);
	stanza = stanza:tag("delay", { xmlns = xmlns_delay, from = bare_jid, stamp = datetime.datetime()});
	return stanza;
end

local function is_important(stanza, session)
	local st_name = stanza and stanza.name or nil;
	if not st_name then return true; end	-- nonzas are always important
	if st_name == "presence" then
		-- TODO check for MUC status codes?
		return false;
	elseif st_name == "message" then
		-- unpack carbon copies
		local carbon, stanza_direction = extract_carbon(stanza);
		--session.log("debug", "mod_csi_battery_saver(%s): stanza_direction = %s, carbon = %s, stanza = %s", id, stanza_direction, carbon and "true" or "false", tostring(stanza));
		if carbon then stanza = carbon; end

		local st_type = stanza.attr.type;

		-- headline message are always not important
		if st_type == "headline" then return false; end

		-- chat markers (XEP-0333) are important, too, because some clients use them to update their notifications
		if stanza:child_with_ns("urn:xmpp:chat-markers:0") then return true; end;

		-- XEP-0353: Jingle Message Initiation incoming call messages
		if stanza:child_with_ns("urn:xmpp:jingle-message:0") then return true; end
		if stanza:child_with_ns("urn:xmpp:jingle-message:1") then return true; end

		-- carbon copied outgoing messages are important (some clients update their notifications upon receiving those) --> don't return false here
		--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
		
		-- check eme
		if stanza:get_child("encryption", "urn:xmpp:eme:0") then return true; end

		local body = stanza:get_child_text("body");
		if st_type == "groupchat" then
			if stanza:get_child_text("subject") then return true; end
			if body == nil or body == "" then return false; end
			-- body contains text, let's see if we want to process it further
			if not filter_muc then		-- default case
				local stanza_important = module:fire_event("csi-is-stanza-important", { stanza = stanza, session = session });
				if stanza_important ~= nil then return stanza_important; end
				return true;		-- deemed unknown/high priority by mod_csi_muc_priorities or some other module
			else
				if body:find(session.username, 1, true) then return true; end
				local rooms = session.rooms_joined;
				if not rooms then return false; end
				local room_nick = rooms[jid.bare(stanza_direction == "in" and stanza.attr.from or stanza.attr.to)];
				if room_nick and body:find(room_nick, 1, true) then return true; end
				return false;
			end
		end
		return body ~= nil and body ~= "";
	end
	return true;
end

module:hook("csi-client-inactive", function (event)
	local session = event.origin;
	if not session.resource then
		session.log("warn", "Ignoring csi if no resource is bound!");
		return;
	end
	if session.pump then
		session.log("debug", "mod_csi_battery_saver(%s): Client is inactive, buffering unimportant outgoing stanzas", id);
		session.pump:pause();
	else
		session.log("debug", "mod_csi_battery_saver(%s): Client is inactive the first time, initializing module for this session", id);
		local pump = new_pump(session, session.send, queue_size);
		pump:pause();
		session.pump = pump;
		session._pump_orig_send = session.send;
		function session.send(stanza)
			session.log("debug", "mod_csi_battery_saver(%s): Got outgoing stanza: <%s>", id, tostring(stanza.name or stanza));
			local important = is_important(stanza, session);
			-- clone stanzas before adding delay stamp and putting them into the queue
			if st.is_stanza(stanza) then stanza = st.clone(stanza); end
			-- add delay stamp to unimportant (buffered) stanzas that can/need be stamped
			if not important and is_stamp_needed(stanza, session) then stanza = add_stamp(stanza, session); end
			-- add stanza to outgoing queue and flush the buffer if needed
			pump:push(stanza);
			if important then
				session.log("debug", "mod_csi_battery_saver(%s): Encountered important stanza, flushing buffer: <%s>", id, tostring(stanza.name or stanza));
				pump:flush();
			end
			return true;
		end
	end
end);

module:hook("csi-client-active", function (event)
	local session = event.origin;
	if not session.resource then
		session.log("warn", "Ignoring csi if no resource is bound!");
		return;
	end
	if session.pump then
		session.log("debug", "mod_csi_battery_saver(%s): Client is active, resuming direct delivery", id);
		session.pump:resume();
	end
end);

-- clean up this session on hibernation end
-- but don't change resumed.send(), it is already overwritten with session.send() by the smacks module
module:hook("smacks-hibernation-end", function (event)
	local session = event.resumed;
	if session.pump then
		session.log("debug", "mod_csi_battery_saver(%s): Hibernation ended, flushing buffer and afterwards disabling for this session", id);
		session.pump:flush(session.send);		-- use the fresh session.send() introduced by the smacks resume
		-- don't reset session.send() because this is not the send previously overwritten by this module, but a fresh one
		-- session.send = session._pump_orig_send;
		session.pump = nil;
		session._pump_orig_send = nil;
	end
end, 1000);		-- high priority to prevent message reordering on resumption (we want to flush our buffers *first*)

function module.unload()
	module:log("info", "%s: Unloading module, flushing all buffers", id);
	local host_sessions = prosody.hosts[module.host].sessions;
	for _, user in pairs(host_sessions) do
		for _, session in pairs(user.sessions) do
			if session.pump then
				session.log("debug", "mod_csi_battery_saver(%s): Flushing buffer and restoring to original session.send()", id);
				session.pump:flush();
				session.send = session._pump_orig_send;
				session.pump = nil;
				session._pump_orig_send = nil;
			end
		end
	end
end

module:log("info", "%s: Successfully loaded module", id);