Mercurial > prosody-modules
view mod_pubsub_mqtt/mod_pubsub_mqtt.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 | 7dbde05b48a9 |
children | 6ba2188e2686 |
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module:set_global(); local mqtt = module:require "mqtt"; local st = require "util.stanza"; local pubsub_services = {}; local pubsub_subscribers = {}; local packet_handlers = {}; function handle_packet(session, packet) module:log("warn", "MQTT packet received! Length: %d", packet.length); for k,v in pairs(packet) do module:log("debug", "MQTT %s: %s", tostring(k), tostring(v)); end local handler = packet_handlers[packet.type]; if not handler then module:log("warn", "Unhandled command: %s", tostring(packet.type)); return; end handler(session, packet); end function packet_handlers.connect(session, packet) session.conn:write(mqtt.serialize_packet{ type = "connack"; data = string.char(0x00, 0x00); }); end function packet_handlers.disconnect(session, packet) session.conn:close(); end function packet_handlers.publish(session, packet) module:log("warn", "PUBLISH to %s", packet.topic); local host, node = packet.topic:match("^([^/]+)/(.+)$"); local pubsub = pubsub_services[host]; if not pubsub then module:log("warn", "Unable to locate host/node: %s", packet.topic); return; end local id = "mqtt"; local ok, err = pubsub:publish(node, true, id, st.stanza("data", { xmlns = "https://prosody.im/protocol/data" }) :text(packet.data) ); if not ok then module:log("warn", "Error publishing MQTT data: %s", tostring(err)); end end function packet_handlers.subscribe(session, packet) for _, topic in ipairs(packet.topics) do module:log("warn", "SUBSCRIBE to %s", topic); local host, node = topic:match("^([^/]+)/(.+)$"); local pubsub = pubsub_subscribers[host]; if not pubsub then module:log("warn", "Unable to locate host/node: %s", topic); return; end local node_subs = pubsub[node]; if not node_subs then node_subs = {}; pubsub[node] = node_subs; end session.subscriptions[topic] = true; node_subs[session] = true; end end function packet_handlers.pingreq(session, packet) session.conn:write(mqtt.serialize_packet{type = "pingresp"}); end local sessions = {}; local mqtt_listener = {}; function mqtt_listener.onconnect(conn) sessions[conn] = { conn = conn; stream = mqtt.new_stream(); subscriptions = {}; }; end function mqtt_listener.onincoming(conn, data) local session = sessions[conn]; if session then local packets = session.stream:feed(data); for i = 1, #packets do handle_packet(session, packets[i]); end end end function mqtt_listener.ondisconnect(conn) local session = sessions[conn]; for topic in pairs(session.subscriptions) do local host, node = topic:match("^([^/]+)/(.+)$"); local subs = pubsub_subscribers[host]; if subs then local node_subs = subs[node]; if node_subs then node_subs[session] = nil; end end end sessions[conn] = nil; module:log("debug", "MQTT client disconnected"); end module:provides("net", { default_port = 1883; listener = mqtt_listener; }); local function tostring_content(item) return tostring(item[1]); end local data_translators = setmetatable({ ["data https://prosody.im/protocol/data"] = tostring_content; ["json urn:xmpp:json:0"] = tostring_content; }, { __index = function () return tostring; end; }); function module.add_host(module) local pubsub_module = hosts[module.host].modules.pubsub if pubsub_module then module:log("debug", "MQTT enabled for %s", module.host); module:depends("pubsub"); pubsub_services[module.host] = assert(pubsub_module.service); local subscribers = {}; pubsub_subscribers[module.host] = subscribers; local function handle_publish(event) -- Build MQTT packet local packet = mqtt.serialize_packet{ type = "publish"; id = "\000\000"; topic = module.host.."/"..event.node; data = data_translators[tostring(event.item.name).." "..tostring(event.item.attr.xmlns)](event.item); }; -- Broadcast to subscribers module:log("debug", "Broadcasting PUBLISH to subscribers of %s/%s", module.host, event.node); for session in pairs(subscribers[event.node] or {}) do session.conn:write(packet); module:log("debug", "Sent to %s", tostring(session)); end end pubsub_services[module.host].events.add_handler("item-published", handle_publish); function module.unload() module:log("debug", "MQTT disabled for %s", module.host); pubsub_module.service.remove_handler("item-published", handle_publish); pubsub_services[module.host] = nil; pubsub_subscribers[module.host] = nil; end end end