Mercurial > prosody-modules
view mod_throttle_presence/mod_throttle_presence.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 | 552faee596b7 |
children |
line wrap: on
line source
local filters = require "util.filters"; local st = require "util.stanza"; module:depends("csi"); local function presence_filter(stanza, session) if getmetatable(stanza) ~= st.stanza_mt then return stanza; -- Things we don't want to touch end if stanza._flush then stanza._flush = nil; return stanza; end local buffer = session.presence_buffer; local from = stanza.attr.from; if stanza.name == "presence" and (stanza.attr.type == nil or stanza.attr.type == "unavailable") then module:log("debug", "Buffering presence stanza from %s to %s", stanza.attr.from, session.full_jid); buffer[stanza.attr.from] = st.clone(stanza); return nil; -- Drop this stanza (we've stored it for later) else local cached_presence = buffer[stanza.attr.from]; if cached_presence then module:log("debug", "Important stanza for %s from %s, flushing presence", session.full_jid, from); stanza._flush = true; cached_presence._flush = true; session.send(cached_presence); buffer[stanza.attr.from] = nil; end end return stanza; end local function throttle_session(event) local session = event.origin; if session.presence_buffer then return; end module:log("debug", "Suppressing presence updates to %s", session.full_jid); session.presence_buffer = {}; filters.add_filter(session, "stanzas/out", presence_filter); end local function restore_session(event) local session = event.origin; if not session.presence_buffer then return; end filters.remove_filter(session, "stanzas/out", presence_filter); module:log("debug", "Flushing buffer for %s", session.full_jid); for jid, presence in pairs(session.presence_buffer) do session.send(presence); end session.presence_buffer = nil; end module:hook("csi-client-inactive", throttle_session); module:hook("csi-client-active", restore_session);