openwrt/package/base-files/files/bin/ipcalc.sh

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#!/bin/sh
. /lib/functions/ipv4.sh
PROG="$(basename "$0")"
# wrapper to convert an integer to an address, unless we're using
# decimal output format.
# hook for library function
_ip2str() {
local var="$1" n="$2"
assert_uint32 "$n" || exit 1
if [ "$decimal" -ne 0 ]; then
export -- "$var=$n"
elif [ "$hexadecimal" -ne 0 ]; then
export -- "$var=$(printf "%x" "$n")"
else
ip2str "$@"
fi
}
usage() {
echo "Usage: $PROG [ -d | -x ] address/prefix [ start limit ]" >&2
exit 1
}
decimal=0
hexadecimal=0
if [ "$1" = "-d" ]; then
decimal=1
shift
elif [ "$1" = "-x" ]; then
hexadecimal=1
shift
fi
if [ $# -eq 0 ]; then
usage
fi
case "$1" in
*/*.*)
# data is n.n.n.n/m.m.m.m format, like on a Cisco router
str2ip ipaddr "${1%/*}" || exit 1
str2ip netmask "${1#*/}" || exit 1
netmask2prefix prefix "$netmask" || exit 1
shift
;;
*/*)
# more modern prefix notation of n.n.n.n/p
str2ip ipaddr "${1%/*}" || exit 1
prefix="${1#*/}"
assert_uint32 "$prefix" || exit 1
if [ "$prefix" -gt 32 ]; then
printf "Prefix out of range (%s)\n" "$prefix" >&2
exit 1
fi
prefix2netmask netmask "$prefix" || exit 1
shift
;;
*)
# address and netmask as two separate arguments
str2ip ipaddr "$1" || exit 1
str2ip netmask "$2" || exit 1
netmask2prefix prefix "$netmask" || exit 1
shift 2
;;
esac
# we either have no arguments left, or we have a range start and length
if [ $# -ne 0 ] && [ $# -ne 2 ]; then
usage
fi
# complement of the netmask, i.e. the hostmask
hostmask=$((netmask ^ 0xffffffff))
network=$((ipaddr & netmask))
broadcast=$((network | hostmask))
count=$((hostmask + 1))
_ip2str IP "$ipaddr"
_ip2str NETMASK "$netmask"
_ip2str NETWORK "$network"
echo "IP=$IP"
echo "NETMASK=$NETMASK"
# don't include this-network or broadcast addresses
if [ "$prefix" -le 30 ]; then
_ip2str BROADCAST "$broadcast"
echo "BROADCAST=$BROADCAST"
fi
echo "NETWORK=$NETWORK"
echo "PREFIX=$prefix"
echo "COUNT=$count"
# if there's no range, we're done
[ $# -eq 0 ] && exit 0
[ -z "$1$2" ] && exit 0
if [ "$prefix" -le 30 ]; then
lower=$((network + 1))
else
lower="$network"
fi
start="$1"
assert_uint32 "$start" || exit 1
start=$((network | (start & hostmask)))
[ "$start" -lt "$lower" ] && start="$lower"
[ "$start" -eq "$ipaddr" ] && start=$((start + 1))
if [ "$prefix" -le 30 ]; then
upper=$(((network | hostmask) - 1))
elif [ "$prefix" -eq 31 ]; then
upper=$((network | hostmask))
else
upper="$network"
fi
range="$2"
assert_uint32 "$range" || exit 1
end=$((start + range - 1))
[ "$end" -gt "$upper" ] && end="$upper"
[ "$end" -eq "$ipaddr" ] && end=$((end - 1))
if [ "$start" -gt "$end" ]; then
echo "network ($NETWORK/$prefix) too small" >&2
exit 1
fi
_ip2str START "$start"
_ip2str END "$end"
if [ "$start" -le "$ipaddr" ] && [ "$ipaddr" -le "$end" ]; then
echo "error: address $IP inside range $START..$END" >&2
exit 1
fi
echo "START=$START"
echo "END=$END"
exit 0