-BEGIN {
- slpos=index(ARGV[1],"/")
- if (slpos != 0) {
- # rearrange arguments to not use compound notation
- ARGV[4]=ARGV[3]
- ARGV[3]=ARGV[2]
- ARGV[2]=substr(ARGV[1],slpos+1)
- ARGV[1]=substr(ARGV[1],0,slpos-1)
- }
- ipaddr=ip2int(ARGV[1])
- dotpos=index(ARGV[2],".")
- if (dotpos == 0)
- netmask=compl32(2**(32-int(ARGV[2]))-1)
- else
- netmask=ip2int(ARGV[2])
-
- network=and(ipaddr,netmask)
- prefix=32-bitcount(compl32(netmask))
-
- print "IP="int2ip(ipaddr)
- print "NETMASK="int2ip(netmask)
- print "NETWORK="int2ip(network)
- if (prefix<=30) {
- broadcast=or(network,compl32(netmask))
- print "BROADCAST="int2ip(broadcast)
- }
- print "PREFIX="prefix
-
- # range calculations:
- # ipcalc <ip> <netmask> <range_start> <range_size>
-
- if (ARGC <= 3)
- exit(0)
-
- if (prefix<=30)
- limit=network+1
- else
- limit=network
-
- start=or(network,and(ip2int(ARGV[3]),compl32(netmask)))
- if (start<limit) start=limit
- if (start==ipaddr) start=ipaddr+1
-
- if (prefix<=30)
- limit=or(network,compl32(netmask))-1
- else
- limit=or(network,compl32(netmask))
-
- end=start+ARGV[4]-1
- if (end>limit) end=limit
- if (end==ipaddr) end=ipaddr-1
-
- if (start>end) {
- print "network ("int2ip(network)"/"prefix") too small" > "/dev/stderr"
- exit(1)
- }
-
- if (ipaddr >= start && ipaddr <= end) {
- print "warning: ipaddr inside range - this might not be supported in future releases of Openwrt" > "/dev/stderr"
- # turn this into an error after Openwrt 24 has been released
- # exit(1)
- }
-
- print "START="int2ip(start)
- print "END="int2ip(end)
-}
+if [ $# -eq 0 ]; then
+ usage
+fi
+
+case "$1" in
+*/*.*)
+ str2ip ipaddr "${1%/*}" || exit 1
+ str2ip netmask "${1#*/}" || exit 1
+ shift
+ ;;
+*/*)
+ str2ip ipaddr "${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
+ netmask=$(((0xffffffff << (32 - prefix)) & 0xffffffff))
+ shift
+ ;;
+*)
+ str2ip ipaddr "$1" || exit 1
+ str2ip netmask "$2" || exit 1
+ shift 2
+ ;;
+esac
+
+if [ $# -ne 0 ] && [ $# -ne 2 ]; then
+ usage
+fi
+
+if ! bitcount prefix "$netmask"; then
+ printf "Invalid netmask (%s)\n" "$netmask" >&2
+ exit 1
+fi
+
+# complement of the netmask, i.e. the hostmask
+hostmask=$((netmask ^ 0xffffffff))
+network=$((ipaddr & netmask))
+broadcast=$((network | hostmask))
+
+ip2str IP "$ipaddr"
+ip2str NETMASK "$netmask"
+ip2str NETWORK "$network"
+
+echo "IP=$IP"
+echo "NETMASK=$NETMASK"
+if [ "$prefix" -le 30 ]; then
+ ip2str BROADCAST "$broadcast"
+ echo "BROADCAST=$BROADCAST"
+fi
+echo "NETWORK=$NETWORK"
+echo "PREFIX=$prefix"
+
+[ $# -eq 0 ] && exit 0
+
+if [ "$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=$(((network | hostmask) - 1))
+else
+ upper="$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