mqtt-syslog-wifi-clients

Detect devices connected to a wifi network via syslog messages. Useful for easy presence detection with virtually no overhead.

Table of Contents

• Use-Case Scenario
• Installation
• Usage
• Future Prospect

Use-Case Scenario

I use a "Digitalisierungsbox Smart" router as my home router, which is a rebranded "Bintec-elmeg be.IP plus". Although I'm very satisfied with this device, for some reason the rebranded version does not provide any API.

This becomes a problem when I want to programmically check which devices are connected to my wifi networks at any given point in time.

Thankfully, the router lets me forward syslog messages to other servers. Among them there are logs from the CAPWAP controller:

XX:XX:XX:XX:XX:XX: New station YY:YY:YY:YY:YY:YY connected to VSS:OpiNet at WTP:OpiAP on Radio1
XX:XX:XX:XX:XX:XX: Station YY:YY:YY:YY:YY:YY disassociated from VSS:OpiNet at WTP:OpiAP on Radio1

The scope of this project is to parse such messages and relay the formatted information to an MQTT broker.

This way, I'm able to detect when I'm home based on my devices' wifi connection and automate things around that.

Installation

1. Prerequisites

   • Golang must be installed
   • rsyslog must be installed

2. Clone this repository

   cd ~
   git clone https://github.com/Opisek/mqtt-syslog-wifi-clients.git
   cd mqtt-syslog-wifi-clients/src

3. Environmental Variables

   • Create the .env file

     cat .env.template > .env

   • Adjust the environmental variables using your text editor of choice

     Variable	Meaning
     MQTT_HOST	The IP Address of your MQTT broker
     MQTT_PORT	The port number your MQTT broker is listening on
     MQTT_USER	The username used to authenticate with the MQTT broker
     MQTT_PASS	The password used to authenticate with the MQTT broker
     MQTT_TOPIC	The base MQTT topic that will be published to

4. Compile the go code using the provided Makefile:

   make

5. rsyslog configuration

   • rsyslog must be listening on UDP (optionally TCP if you know what you're doing) for your router to communicate with it.

     This is typically done by uncommenting the following two lines in /etc/rsyslog.conf:

     module(load="imudp")
     input(type="imudp" port="514")

   • rsyslog must have the module omprog activated. This is so that we can forward the logs to external programs.

     This is typically done by adding the following line to the beginning of /etc/rsyslog.conf:

     module(load="omprog")

   • Open the wificlients.conf configuration file from the cloned repository and adjust the following:

     • Change HOST to the IP address of your router e.g., 10.0.0.1
     • Change BINARY to the path of the compiled go file e.g., /home/opisek/mqtt-syslog-wifi-clients/src/mqtt-syslog-wifi-clients

   • Copy the edited wificlient.conf file to /etc/rsyslog.d/

6. Set up your router to use your syslog server via UDP (or TCP)

7. Restart rsyslog:

   sudo systemctl restart rsyslog
   

Usage

Homeassistant now automatically detects devices on your network, provided it's connected to the same MQTT broker.

For every MAC address on your network, a new device will be created e.g., Wifi Client XX:XX:XX:XX:XX:XX.

Every device exposes the following entities:

Name	ID	Meaning
Ap	sensor.wifi_client_xx_xx_xx_xx_xx_xx_ap	The name of the access point that the device is connected to
Connected	sensor.wifi_client_xx_xx_xx_xx_xx_xx_connected	online or offline
Radio	sensor.wifi_client_xx_xx_xx_xx_xx_xx_radio	The number of the access point's radio that the device is connected to
Ssid	sensor.wifi_client_xx_xx_xx_xx_xx_xx_ssid	The SSID that the device is connected to
Station	sensor.wifi_client_xx_xx_xx_xx_xx_xx_station	The MAC address of the access point that the device is connected to

Every entity other than Connected is only available when Connected is online.

Since every MAC address gets its own device, make sure to turn off your devices' ability to randomize MAC addresses every time you connect to your wifi.

Future Prospect

In the future I'd like to automate the configuration and copying of various files by expanding on the Makefile.