#!/bin/ash
#
# For Ubiquiti the default TX-power on OpenWrt is above regulatory limits.
# see https://github.com/freifunk-berlin/firmware/issues/381
#

[ ! $(command -v iwinfo) ] && exit 0
iwinfo|grep -q 'NanoStation M2\|NanoStation Loco M2' || exit 0

. /lib/functions/guard.sh
guard "NSm2_txpower"

set_default_txpower() {
 echo "setting txpower value to $1 dBm"
 uci set wireless.radio0.txpower=$1
 uci commit wireless
}

MAX_TX_2G=20
# get "TX offset" of 1st interface, if this is unknown set it to 0dB
# then only return the numerical value
ANT_GAIN=$(iwinfo |grep -m 1 "TX power offset:" |sed -e "s/unknown/0 dB/" |tr -dc '0-9')
NEW_TX=$(echo $(($MAX_TX_2G - $ANT_GAIN)))

CURR_TX=$(uci -q get wireless.radio0.txpower)
# check if txpower is defined in config
if [ $? -ne 0 ]; then
  echo -n "txpower not defined - "
  set_default_txpower $NEW_TX
elif [ $CURR_TX -gt $NEW_TX ]; then
  set_default_txpower $NEW_TX
fi