# CZI presence detector
Tool to detect the presence of defined devices by their WiFi MAC addresses.

## How scanning works
Sets the wifi adapter into monitor mode, then listens to surrounding packets listing all detected devices into `wifi_map.yaml`. 
Then, periodically filters the results by the mac addresses that opted in on the website from `identities.json` and sends all matched identities to the website via a signed webhook. This website stores the presence information locally and displays it with `website/index.php` with a timestamp of the last update.

## What the website is capable of
Shows the last update of the `upload.py` routine. It also allows to add identities by their name and mac and to delete identities by their mac. The mac addresses are hashed server-side and then stored into the world-accessible `identities.json`.

## Set-up
Dependencies: 
- Scanner: Python3, trackerjacker (pip3)
- Website: php

Configs to change:
- `scanner/live-scanner.sh`:
  - WiFi adapter name
  - Possibly some more system-specific changes
- `scanner/upload.py`:
  - URLs for webhook and identities
  - webhook secret
- `public/update.php`:
  - webhook secret

Put `scanner` onto the scanning device (e.g. Raspberry Pi). Let `live-scanner.sh` and `live-uploader.sh` running in the background, e.g. by the Systemd services below.
Put `website` onto a php-capable webserver and point your domain to it.

## Systemd services
Service for scanning packets in the background
```systemd
[Unit]
Description=CZI Presence Detector - Scanner
After=network.target

[Service]
User=root
Group=root
Restart=always
WorkingDirectory=/path/to/scanner
ExecStart=/path/to/scanner/live-scanner.sh

[Install]
WantedBy=multi-user.target
```
Service for uploading every $n seconds
```systemd
[Unit]
Description=CZI Presence Detector - Uploader
After=network.target

[Service]
User=pi
Group=pi
Restart=always
WorkingDirectory=/path/to/scanner
ExecStart=/path/to/scanner/live-uploader.sh

[Install]
WantedBy=multi-user.target
```