The mavfwd tool

mavfwd forwards MAVLink packets between the air unit and the ground station. This channel can also send commands to the air unit. Any text sent to the ground station’s MAVLink port is executed as a root shell command on the air unit.

Enable incoming connections on the ground station

Edit /etc/wifibroadcast.cfg and change the [gs_mavlink] peer from outgoing to incoming:

[gs_mavlink]
peer = 'connect://127.0.0.1:14550'  # outgoing connection
# peer = 'listen://0.0.0.0:14550'   # incoming connection
# peer = 'connect://127.0.0.1:14550'  # outgoing connection
peer = 'listen://127.0.0.1:14550'   # incoming connection

Caution

Keep the listener on 127.0.0.1. With 0.0.0.0, any host that can reach the ground station can run commands on the air unit.

Update settings

echo curl http://localhost/api/v1/set?video0.fps=120 > /dev/udp/localhost/14550

Update drone key

file="echo $(base64 -w0 drone.key) | base64 -d > /etc/drone.key"
echo $file > /dev/udp/localhost/14550

Caution

Send the air unit’s own key (drone.key), not the ground station’s gs.key. A wrong key breaks the link that carries these commands, and recovery requires physical access to the air unit.

Update configuration

file="echo $(base64 -w0 wfb.conf) | base64 -d > /etc/wfb.conf"
echo $file > /dev/udp/localhost/14550