mailcow/data/Dockerfiles/acme/expand6.sh

132 lines
3.1 KiB
Bash
Executable File

#!/bin/bash
##################################################################################
#
# Copyright (C) 2017 Craig Miller
#
# See the file "LICENSE" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# Distributed under GPLv2 License
#
##################################################################################
# IPv6 Address Expansion functions
#
# by Craig Miller 19 Feb 2017
#
# 16 Nov 2017 v0.93 - added CLI functionality
VERSION=0.93
empty_addr="0000:0000:0000:0000:0000:0000:0000:0000"
empty_addr_len=${#empty_addr}
function usage {
echo " $0 - expand compressed IPv6 addresss "
echo " e.g. $0 2001:db8:1:12:123::456 "
echo " "
echo " -t self test"
echo " "
echo " By Craig Miller - Version: $VERSION"
exit 1
}
if [ "$1" == "-h" ]; then
#call help
usage
fi
#
# Expands IPv6 quibble to 4 digits with leading zeros e.g. db8 -> 0db8
#
# Returns string with expanded quibble
function expand_quibble() {
addr=$1
# create array of quibbles
addr_array=(${addr//:/ })
addr_array_len=${#addr_array[@]}
# step thru quibbles
for ((i=0; i< $addr_array_len ; i++ ))
do
quibble=${addr_array[$i]}
quibble_len=${#quibble}
case $quibble_len in
1) quibble="000$quibble";;
2) quibble="00$quibble";;
3) quibble="0$quibble";;
esac
addr_array[$i]=$quibble
done
# reconstruct addr from quibbles
return_str=${addr_array[*]}
return_str="${return_str// /:}"
echo $return_str
}
#
# Expands IPv6 address :: format to full zeros
#
# Returns string with expanded address
function expand() {
if [[ $1 == *"::"* ]]; then
# check for leading zeros on front_addr
if [[ $1 == "::"* ]]; then
front_addr=0
else
front_addr=$(echo $1 | sed -r 's;([^ ]+)::.*;\1;')
fi
# check for trailing zeros on back_addr
if [[ $1 == *"::" ]]; then
back_addr=0
else
back_addr=$(echo $1 | sed -r 's;.*::([^ ]+);\1;')
fi
front_addr=$(expand_quibble $front_addr)
back_addr=$(expand_quibble $back_addr)
new_addr=$empty_addr
front_addr_len=${#front_addr}
back_addr_len=${#back_addr}
# calculate fill needed
num_zeros=$(($empty_addr_len - $front_addr_len - $back_addr_len - 1))
#fill_str=${empty_addr[0]:0:$num_zeros}
new_addr="$front_addr:${empty_addr[0]:0:$num_zeros}$back_addr"
# return expanded address
echo $new_addr
else
# return input with expandd quibbles
expand_quibble $1
fi
}
# self test - call with '-t' parameter
if [ "$1" == "-t" ]; then
# add address examples to test
expand fd11::1d70:cf84:18ef:d056
expand 2a01::1
expand fe80::f203:8cff:fe3f:f041
expand 2001:db8:123::5
expand 2001:470:ebbd:0:f203:8cff:fe3f:f041
# special cases
expand ::1
expand fd32:197d:3022:1101::
exit 1
fi
# allow script to be sourced (with no arguements)
if [[ $1 != "" ]]; then
# validate input is an IPv6 address
if [[ $1 == *":"* ]]; then
expand $1
else
echo "ERROR: unregcognized IPv6 address $1"
exit 1
fi
fi