view mod_auto_answer_disco_info/mod_auto_answer_disco_info.lua @ 4651:8231774f5bfd

mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.
author Kim Alvefur <zash@zash.se>
date Sun, 22 Aug 2021 13:22:59 +0200
parents 05c74210c007
children
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module:depends("cache_c2s_caps");

local st = require "util.stanza";

local function disco_handler(event)
	local stanza, origin = event.stanza, event.origin;
	local query = stanza.tags[1];
	local to = stanza.attr.to;
	local node = query.attr.node;

	local target_session = prosody.full_sessions[to];
	if target_session == nil then
		return;
	end

	local disco_info = target_session.caps_cache;
	if disco_info ~= nil and (node == nil or node == disco_info.attr.node) then
		local iq = st.reply(stanza);
		iq:add_child(st.clone(disco_info));
		local log = origin.log or module._log;
		log("debug", "Answering disco#info on the behalf of %s", to);
		module:send(iq);
		return true;
	end
end

module:hook("iq/full", function(event)
	local stanza = event.stanza;
	if stanza.attr.type == "get" then
		if stanza:get_child("query", "http://jabber.org/protocol/disco#info") then
			return disco_handler(event);
		end
	end
end, 1);