ASN/IP/Route/hostname command line lookup tool to map any network to the corresponding ASN and prefix

asn

#!/usr/bin/env bash

##############################################################################
# ----------------------------------------------------------------------
# ASN/IPv4/Prefix lookup tool. Uses Team Cymru's whois service for data.
# ----------------------------------------------------------------------
# example usage:
#  asn <ASnumber>      -- to lookup matching ASN data. Supports "as123" and
#                         "123" formats (case insensitive)
#  asn <IP.AD.DR.ESS>  -- to lookup matching route and ASN data
#  asn <ROUTE>         -- to lookup matching ASN data
#  asn <host.name.tld> -- to lookup matching IP, route and ASN data (supports
#                         multiple IPs - e.g. DNS RR)
#
# Author: Adriano Provvisiero - BV Networks 2017
# Minor color and format updates by Danny Ben Shitrit 2019
#
##############################################################################

WhoisASN(){
  found_asname=$(whois -h whois.cymru.com " -f -w -c -p as$1" | sed -e 's/\ *|\ */|/g' | awk -F '[|]' {'print $3'})
  printf "$red[AS$1] $green$found_asname\n$magenta"
}

WhoisIP(){
  printf "\n$magenta%s ${cyan}route: %s\n$red[AS%s] $green%s\n" "$1" "$found_route" "$found_asn" "$found_asname"
}

LookupASNAndRouteFromIP(){
  found_route=""
  found_asn=""
  found_asname=""
  output=$(whois -h whois.cymru.com " -f -p $1" | sed -e 's/\ *|\ */|/g')
  found_asn=$(echo $output | awk -F'[|]' {'print $1'})
  found_asname=$(echo $output | awk -F'[|]' {'print $4'})
  found_route=$(echo $output | awk -F'[|]' {'print $3'})
}

ResolveHostnameToIPList(){
  ip=$(host $1 | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}')
  echo -e "$ip\n"
}

green="\e[32m"
cyan="\e[36m"
magenta="\e[35m"
blue="\e[94m"
red="\e[31m"

input=$(echo $1 | sed -e 's/\/.*//g' | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}')
if [ -z "$input" ]; then
  # Input is not an IPv4 Address. Check if it is a number (ASN)
  asn=$(echo $1 | sed -e 's/[a|A][s|S]//g' | grep -E "^[0-9]*$")
  if [ -z "$asn" ]; then
    # Input is not an ASN either. Consider it a hostname and try to resolve it.
    echo -e -n "${blue}Resolving \"$1\"... "
    ip=$(ResolveHostnameToIPList $1)
    if [ -z "$ip" ]; then
      echo -e "\e[97m\e[101mError: unable to resolve hostname\e[39m\e[49m"
      tput sgr0
      exit
    fi
    numips=$(echo "$ip" | wc -l)
    [[ $numips = 1 ]] && s="" || s="es"
    echo -e "$blue$numips IP address$s found:"
    for singleip in $ip; do
      LookupASNAndRouteFromIP $singleip
      WhoisIP $singleip
    done
    tput sgr0
    exit
  else
    # Input is an ASN
    WhoisASN $asn
    tput sgr0
    exit
  fi
else
  # Input is an IPv4
  LookupASNAndRouteFromIP $input
  if [ -z "$found_asname" ] && [ -z "$found_route" ]; then
    echo -e "\e[97m\e[101mError: no data found for $input\e[39m\e[49m"
    tput sgr0
    exit
  fi
  echo -e "${green}1 IP address found:\e[39m"
  WhoisIP $input
  tput sgr0
  exit
fi