Modified version of sshfilter.sh to allow for ipv6 and local IP filtering

sshfilter.sh

#!/bin/bash
# based on script from http://www.axllent.org/docs/view/ssh-geoip
# based on script from https://gist.github.com/ManfMert/b34f098ad6e5094225ff9366ae4e9d7d
# License: WTFPL
# location /usr/local/bin

function private_ip()
{
  local  ip=$1
  local  stat=1

  if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
    OIFS=$IFS
    IFS='.'
    ip=($ip)
    IFS=$OIFS

    # ip address in decimal
    dec=$[((((( ${ip[0]} * 256 ) + ${ip[1]} ) * 256 ) + ${ip[2]} ) * 256 ) + ${ip[3]}]
    #echo "ip dec: "$dec
    # Soure: https://en.wikipedia.org/wiki/Reserved_IP_addresses
    scope=""
    
    # 192.168.0.0 to 192.168.255.255
    if [[ $dec -ge 0xC0A80000 && $dec -le 0xC0A8FFFF ]]; then
      scope="Private network"
    # 127.0.0.0 to 127.255.255.255
    elif [[ $dec -ge 0x7F000000 && $dec -le 0x7FFFFFFF ]]; then
      scope="Host"
    fi
  fi
  echo $scope
}
    
# UPPERCASE space-separated country codes to ACCEPT
ALLOW_COUNTRIES="AR"
LOGDENY_FACILITY="authpriv.notice"

if [ $# -ne 1 ]; then
  echo "Usage:  `basename $0` <ip>" 1>&2
  exit 0 # return true in case of config issue
fi

if [[ "`echo $1 | grep ':'`" != "" ]] ; then
  COUNTRY=`/usr/bin/geoiplookup6 "$1" | awk -F ": " '{ print $2 }' | awk -F "," '{ print $1 }' | head -n 1`
else
  COUNTRY=`/usr/bin/geoiplookup "$1" | awk -F ": " '{ print $2 }' | awk -F "," '{ print $1 }' | head -n 1`
fi
# [[ $COUNTRY = "IP Address not found" || $ALLOW_COUNTRIES =~ $COUNTRY ]] && RESPONSE="ALLOW" || RESPONSE="DENY"

RESPONSE="DENY"
if [[ $ALLOW_COUNTRIES =~ $COUNTRY ]]; then
  RESPONSE="ALLOW"
elif [[ $COUNTRY = "IP Address not found" ]]; then
  COUNTRY=`private_ip $1`
  if [[ $COUNTRY != "" ]]; then
    RESPONSE="ALLOW"
  else
    COUNTRY="IP Address not found"
  fi
fi

if [[ "$RESPONSE" == "ALLOW" ]] ; then
  logger -p auth.notice "$RESPONSE sshd/vsftpd connection from $1 ($COUNTRY)"
  exit 0
else
  logger -p auth.warn "$RESPONSE sshd/vsftpd connection from $1 ($COUNTRY)"
  exit 1
fi