Nodes running the official b20170319-v (or newer) build report the (raw) txpower configuration. It is added by ffmap-backend to the nodes.json. This information can be combined with the offset table from libiwconfig. The resulting data can be compared again the allowed limits.
txpower-check simplifies the search for misconfigured nodes:
curl https://mapdata.freifunk-vogtland.net/nodes.json -o nodes.json
./txpower-check.py nodes.json
Both commands will be started automaticall when calling
./check.sh
The output is a simple list of links to the map and followed by the offending transmission power settings
https://vogtland.freifunk.net/map/#!/map/dc9fdb72567d
* 5.180 GHz: 36.00 dBm (limit 20.00 dBm)
https://vogtland.freifunk.net/map/#!/map/f4f26dc1faa2
* 2.462 GHz: 26.00 dBm (limit 20.00 dBm)