Ash script to manage the on/off state of the 5GHz band radio based on usage (i.e. devices connected) for Asus routers running custom firmware by Padavan (https://code.google.com/p/rt-n56u/)

wlan5_manager.sh

#!/bin/bash
# Script to auto start/stop 5GHz wireless radio based on presence of
# certain MAC addresses on the LAN.
# CODITION TO :
#       * TURN ON radio - one or more device(s) is/are on LAN
#       * TURN OFF radio - ALL devices are _NOT_ on 5GHz band
#
# REQUIRED ENTWARE PACKAGES :
#       * wget - Get files over HTTP/S, FTP
#
# Author: SidneyC <sidneyc_at_outlook_dot_com>
#
# CHANGELOG
# ---------
# 27/01/2015 Initial release
# 01/02/2015 Made path to wget explicit to avoid issues when running via cron
#            Added sanity check to make sure we get a response back from wget
#            before proceeding any further
#
#################################################################################

# path to file containing credentials to access the web UI
# file should contain only a single line in the format username,password
# with no spaces before and after.
# NOTE: THIS FILE MUST BE MANUALLY CREATED FIRST BEFORE RUNNING THIS SCRIPT
WEB_ACCESS_FILE="/opt/home/admin/.webaccess"

# List of MAC addresses to check for is in the file specified below.
# Note that this script will append new/unseen 5GHz devices to this
# file if they are connected to the 5GHz band at the time this script is run
MACS_FILE="/opt/etc/wlan5_trigger_macs"

# This script uses the wget package from entware as the default implementation
# in busybox does not handle HTTP authentication
WGET_BIN="/opt/bin/wget"

# INTERNAL VARIABLES
BASE_URL="http://localhost"
MACS_LIST=""

# SUBROUTINES
Get5gDevicesOn2g() {
  WEB_OUTPUT=$($WGET_BIN -qO- --user=$WEB_USER --password=$WEB_PSWD $BASE_URL/Main_WStatus2g_Content.asp | sed -n "/<textarea .*>/,/<\/textarea>/p" | sed "s/<.*>//")
  # SANITY CHECK - make sure we get something back in the output
  if [[ -z "$WEB_OUTPUT" ]]; then
    echo "[`date`] FATAL ERROR - did not get a valid response from web UI."
    exit 1;
  fi
  #echo "DEBUG- $WEB_OUTPUT"
  DEV_CONNECTED=$(echo "$WEB_OUTPUT" | grep -E "^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})" | cut -d ' ' -f1)
  #echo "DEBUG- $DEV_CONNECTED"
  G5DO2="" #initialise the var
  for i in $DEV_CONNECTED; do
    #echo "DEBUG - in loop - $i"
    if [[ ! -z $(echo "$MACS_LIST" | grep "$i") ]]; then
      if [[ -z $G5DO2 ]]; then
        G5DO2="$i"
      else
        G5DO2="$G5DO2 $i"
      fi
      if [[ $1 == "one" ]]; then #user only asked for the first device found
        #no more tests needed, let's break out of the loop
        break
      fi
    fi
  done
}

FindHostnameFromMac() {
  FHFM=$(sed -n "s/.*$1,\(.*\),.,.,./\1/p" /tmp/static_ip.inf)
}

# Let's try to retreive the web access username & password
WEB_USER=$(cut -d ',' -f1 $WEB_ACCESS_FILE)
WEB_PSWD=$(cut -d ',' -f2 $WEB_ACCESS_FILE)

# SANITY CHECK #1 - make sure we have valid login credentials to access web UI
if [[ -z "$WEB_USER" || -z "$WEB_PSWD" ]]; then
  echo "[`date`] ERROR - Could not retreive credentials to access web UI from file ($WEB_ACCESS_FILE). Does it exist or is in the correct format?"
  exit 1;
fi

# SANITY CHECK #2 - if MACS_FILE does not exist, create it
if [[ ! -e $MACS_FILE ]]; then
  echo "[`date`] WARNING - file ($MACS_FILE) does not exist. Creating one."
  touch $MACS_FILE
fi

# Get the list of macs we will use to search for
MACS_LIST=$(grep -v '^#' $MACS_FILE | cut -d ',' -f1)
#echo "DEBUG- $MACS_LIST"

# we use the output of the Wireless 5GHz page for most of our checks
#wget -P=/tmp --user=$WEB_USER --password=$WEB_PSWD $BASE_URL/Main_WStatus_Content.asp
# zoom to the section we are after
#WEB_OUTPUT=$(sed -n "/<textarea .*>/,/<\/textarea>/p" /tmp/Main_WStatus2g_Content.asp)
WEB_OUTPUT=$($WGET_BIN -qO- --user=$WEB_USER --password=$WEB_PSWD $BASE_URL/Main_WStatus_Content.asp | sed -n "/<textarea .*>/,/<\/textarea>/p" | sed "s/<.*>//")
#echo "DEBUG- $WEB_OUTPUT"
# SANITY CHECK - make sure we get something back in the output
if [[ -z "$WEB_OUTPUT" ]]; then
  echo "[`date`] FATAL ERROR - did not get a valid response from web UI."
  exit 1;
fi

# start by checking status of 5GHz radio
if [[ -z "$(echo "$WEB_OUTPUT" | grep "Radio 5GHz is disabled")" ]]; then
  echo "[`date`] 5GHz radio is on."
  # 5GHz radio is on. let's see if any devices are connected
  DEV_CONNECTED=$(echo "$WEB_OUTPUT" | grep -E "^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})" | cut -d ' ' -f1)
  #echo "DEBUG- $DEV_CONNECTED"
  if [[ ! -z "$DEV_CONNECTED" ]]; then
    echo "[`date`] `echo "$DEV_CONNECTED" | wc -l` device(s) connected to 5GHz radio."
    #yes, let's add any new devices we have not seen into the MACS_FILE
    for i in $DEV_CONNECTED; do
      #NOTE - for the test below, we use $MACS_FILE instead of $MACS_LIST
      #       because it may exist in file but commented out by user
      if [[ -z "$(grep "$i" $MACS_FILE)" ]]; then
        #found one, let's add it
        #let's try to find and add the hostname if available
        FindHostnameFromMac $i
        echo "$i,$FHFM,added on `date`" >> $MACS_FILE
        if [[ -z $FHFM ]]; then
          FHFM=$i
        fi
        echo "[`date`] Found a new device ($FHFM) on 5GHz radio. Adding to $MACS_FILE."
      fi
    done
  else
    echo "[`date`] No devices connected to 5GHz radio."
    #no devices are connected. Before we shut it down, check to see
    #if any 5GHz device is connected to the 2.4GHz band. If so, do nothing.
    Get5gDevicesOn2g "one"
    if [[ -z $G5DO2 ]]; then
      echo "[`date`] Did not find any 5GHz devices connected to 2.4GHz radio as well. Shutting down 5GHz radio."
      /sbin/radio5_disable
    else
      FindHostnameFromMac $G5DO2
      if [[ -z $FHFM ]]; then
        FHFM=$G5DO2
      fi
      echo "[`date`] Found at least 1 5GHz device ($FHFM) connected to 2.4GHz radio. Leaving 5GHz radio on."
    fi
  fi
else
  echo "[`date`] 5GHz radio is off."
  # 5GHz radio is off. Let's scan the 2.4GHz list for any 5GHz devices that are connected to it
  Get5gDevicesOn2g "one"
  if [[ ! -z $G5DO2 ]]; then
    #yes, we have one or more such devices. Let's turn on the 5GHz radio
    FindHostnameFromMac $G5DO2
    if [[ -z $FHFM ]]; then
      FHFM=$G5DO2
    fi
    echo "[`date`] Found a 5GHz device ($FHFM) on 2.4GHz radio. Starting 5GHz radio."
    /sbin/radio5_enable
  else
    echo "[`date`] Did not find any 5GHz devices connected to 2.4GHz radio. Leaving 5GHz radio off."
  fi
fi

exit 0;