MQTT-SN Gateway: DTLS

This module is part of mqttsngw. It is responsible for handling incoming DTLS connections from the sensor network and parsing and generating MQTT-SN packets.

All packet conversions are handled by mqttsn-packet.

Factory

const DTLS = require('mqttsngw-dtls');
mqttsngw.attach(DTLS(opts));

Creates a new DTLS factory and attaches it to an existing instance of mqttsngw. opts has the following fields:

• log: Optional. An object containing logging callbacks for all log levels (error, warn, info, debug). Every callback is called with a human-readable message as the first argument followed by an object containing more information regarding the event: { error: (msg, info) => { ... }, ...}.
• guard: Optional. Callback function that is called for every parsed ingress packet: (peer, certInfo, packet) => { ... }. Returns true if the packet shall pass and false if it shall not pass. Arguments for decision-making:
  • peer: Object containing address and port of the sensor.
  • certInfo: Objection containing further details of the client certificate if presented.
  • packet: Packet parsed by mqttsn-packet.
• bind: options of the Node.js Dgram bind method
• All other options accepted by the createServer method of openssl-dtls

Events

All in all just two events are consumed and emitted by the DTLS module on the event bus.

Consumed

| Event | Description | | ------------------------------ | ----------- | | snUnicastOutgress,*,* | A packet shall be sent to a sensor |

Emitted

| Event | Description | | ------------------------------ | ----------- | | snUnicastIngress,*,* | A packet has been received from a sensor |