simple script to run a triggered snmp command get to wifi client info

wl_snmpd.sh

#!/bin/sh

# Modified script to provide detailed wifi client info on atheros 9k based device with LEDE/OpenWRT.  Script requires 'bc'
#    package to output results.  Output was designed to match the OID results from an Engenius EAP600 when queried via SNMP.
#
# Outputs summary of client stats for each radio in the following format "mac address, SNR, total data received, 
#      connection rate"
# Example output:
# iso.3.6.1.4.1.14125.2.1.1.15.9.0 = STRING: "cc:aa:bb:dd:ee:ff -56  445942Kb 105M,"
# iso.3.6.1.4.1.14125.2.1.1.16.9.0 = STRING: "aa:bb:cc:dd:ee:ff -64 18388740Kb 78M, bb:bb:cc:dd:ee:ff -63  77624Kb 44M,"
#
# To use this script, 
#  1. Install bc package on OpenWRT/LEDE
#  2. Install snmpd package on OpenWRT/LEDE
#  3. Copy this file to a suitable directory on the openwrt device (e.g. mounted usb drive or /root) and make executable.
#  4. Modify UCI configuration file for snmpd in /etc/config/snmpd to include the following:
#      config pass
#          option miboid .1.3.6.1.4.1.14125.2.1.1
#          option prog /root/wl_snmpd.sh  (change this to match the path you placed the file in)
#          option persist 1
#  5. Reboot device.
#


place=".1.3.6.1.4.1.14125.2.1.1"

refresh() {
  id=1 

  ath1_clients=''
  for interface in $(ifconfig | grep wlan1 | cut -d" " -f1)
  do  
    ath1_clients=$ath1_clients' '$(iw dev $interface station dump)
  done

  mib51=""
  for mac in $(echo $ath1_clients | grep -o -E '([a-z0-9]+):([a-z0-9]+):([a-z0-9]+):([a-z0-9]+):([a-z0-9]+):([a-z0-9]+)')
  do
    if test $id -gt 1
    then
      mib51=$mib51'  '
    fi
    signal=$(echo $ath1_clients | grep -o -E 'signal avg: -([0-9]*)' | sed -n ${id}p | cut -d" " -f3)
    tx_bytes=$(echo $ath1_clients | grep -o -E 'tx bytes: ([0-9]*)' | sed -n ${id}p | cut -d" " -f3)
    tx_bytes=`echo "$tx_bytes/1000" | bc` 
    bitrate=$(echo $ath1_clients | grep -o -E 'rx bitrate: ([0-9]*)' | sed -n ${id}p | cut -d" " -f3)
    let id=$id+1
    result=$mac' '$signal'  '$tx_bytes'Kb '$bitrate'M,'
    mib51=$mib51$result
  done

  id=1

  ath0_clients=''
  for interface in $(ifconfig | grep wlan0 | cut -d" " -f1)
  do  
    ath0_clients=$ath0_clients' '$(iw dev $interface station dump)
  done
  
  mib24=""
  for mac in $(echo $ath0_clients | grep -o -E '([a-z0-9]+):([a-z0-9]+):([a-z0-9]+):([a-z0-9]+):([a-z0-9]+):([a-z0-9]+)')
  do
    if test $id -gt 1
    then
      mib24=$mib24'  '
    fi
    signal=$(echo $ath0_clients | grep -o -E 'signal avg: -([0-9]*)' | sed -n ${id}p | cut -d" " -f3)
    tx_bytes=$(echo $ath0_clients | grep -o -E 'tx bytes: ([0-9]*)' | sed -n ${id}p | cut -d" " -f3)
    tx_bytes=`echo "$tx_bytes/1000" | bc`
    bitrate=$(echo $ath0_clients | grep -o -E 'tx bitrate: ([0-9]*)' | sed -n ${id}p | cut -d" " -f3)
    let id=$id+1
    result=$mac' '$signal'  '$tx_bytes'Kb '$bitrate'M,'
    mib24=$mib24$result
  done
  
  value_136141141252111590=$mib24;
  type_136141141252111590='string';
  
  value_136141141252111690=$mib51;
  type_136141141252111690='string';
  
  getnext_13614114125211="$place.15.9.0"
  getnext_136141141252111590="$place.16.9.0"
  getnext_136141141252111690="NONE"
}
refresh
LASTREFRESH=0
  
while read CMD
do
  case "$CMD" in
    PING)
      echo PONG
      continue 
      ;;
    getnext)
      read REQ
      let REFRESH=$(date +%s)-$LASTREFRESH
      if test $REFRESH -gt 14
      then
        LASTREFRESH=$(date +%s)
        refresh
      fi
      
      oid=$(echo $REQ | tr -d .) 
      eval ret=\$getnext_${oid}
      if test "x$ret" = "xNONE"
      then
        echo NONE
        continue 
      fi 
      ;;
    get)
      read REQ
      let REFRESH=$(date +%s)-$LASTREFRESH
      if test $REFRESH -gt 14
      then
        LASTREFRESH=$(date +%s)
        refresh
      fi
      if test "x$REQ" = "x$place"
      then
        echo NONE
        continue
      else
        ret=$REQ
      fi
      ;;
    *)
      read REQ
      if test "x$REQ" = "x$place"
      then
        echo NONE
        continue 
      else
        ret=$REQ
      fi
      ;;
  esac

  oid=$(echo $ret | tr -d .) 
  if eval test "x\$type_${oid}" != "x"
  then
    echo $ret
    eval echo "\$type_${oid}"
    eval echo "\$value_${oid}"
  else
    echo NONE
  fi

done