normalize.sh

#!/bin/sh
##############################################################################
#
# Copyright 2015 spf-tools team (see AUTHORS)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
#     Unless required by applicable law or agreed to in writing, software
#     distributed under the License is distributed on an "AS IS" BASIS,
#     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#     See the License for the specific language governing permissions and
#     limitations under the License.
#
##############################################################################
#
# Usage: ./despf.sh domain | ./normalize.sh
#  E.g.: ./despf.sh microsoft.com | ./normalize.sh

test -n "$DEBUG" && set -x

test "$1" = "-i" && ignore=1

ip2int() {
  local a b c d
  echo $1 | while IFS="." read a b c d ; do
    echo $(((((((a << 8) | b) << 8) | c) << 8) | d))
  done
}

int2ip() {
  local ui32=$1; shift
  local ip n
  for n in 1 2 3 4; do
    ip=$((ui32 & 0xff))${ip:+.}$ip
    ui32=$((ui32 >> 8))
  done
  echo $ip
}

network() {
  local ia netmask
  echo $1 | while  IFS="/" read ia netmask; do
    local addr=$(ip2int $ia);
    local mask=$((0xffffffff << (32 -$netmask)));
    echo $(int2ip $((addr & mask)))/$netmask
  done
}

while
  read i
do
  cidr=$(echo $i | cut -d: -f2-)
  ipver=$(echo $i | cut -d: -f1)
  if [ "x$ipver" = "xip4" ] ; then
    # check if is a CIDR
    nm=$(echo $i | cut -s -d/ -f2)
    if [ "x$nm" = "x32" ] ; then
      echo $i
    elif [ "x$nm" = "x" ] ; then
      echo $i
    else
      result="ip4:$(network $cidr)"
      test -n "$ignore" || { echo $result; continue; }
      test "$result" = "$i" && echo $i || true
    fi
  else
    echo $i
  fi
done