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

   1 #!/bin/sh
   2
   3 . /lib/functions/ipv4.sh
   4
   5 PROG="$(basename "$0")"
   6
   7 # hook for library function
   8 _ip2str() {
   9     local var="$1" n="$2"
  10     assert_uint32 "$n" || exit 1
  11
  12     if [ "$decimal" -ne 0 ]; then
  13         export -- "$var=$n"
  14     elif [ "$hexadecimal" -ne 0 ]; then
  15         export -- "$var=$(printf "%x" "$n")"
  16     else
  17         ip2str "$@"
  18     fi
  19 }
  20
  21 usage() {
  22     echo "Usage: $PROG [ -d | -x ] address/prefix [ start limit ]" >&2
  23     exit 1
  24 }
  25
  26 decimal=0
  27 hexadecimal=0
  28 if [ "$1" = "-d" ]; then
  29     decimal=1
  30     shift
  31 elif [ "$1" = "-x" ]; then
  32     hexadecimal=1
  33     shift
  34 fi
  35
  36 if [ $# -eq 0 ]; then
  37     usage
  38 fi
  39
  40 case "$1" in
  41 */*.*)
  42     str2ip ipaddr "${1%/*}" || exit 1
  43     str2ip netmask "${1#*/}" || exit 1
  44     shift
  45     ;;
  46 */*)
  47     str2ip ipaddr "${1%/*}" || exit 1
  48     prefix="${1#*/}"
  49     assert_uint32 "$prefix" || exit 1
  50     if [ "$prefix" -gt 32 ]; then
  51         printf "Prefix out of range (%s)\n" "$prefix" >&2
  52         exit 1
  53     fi
  54     netmask=$(((0xffffffff << (32 - prefix)) & 0xffffffff))
  55     shift
  56     ;;
  57 *)
  58     str2ip ipaddr "$1" || exit 1
  59     str2ip netmask "$2" || exit 1
  60     shift 2
  61     ;;
  62 esac
  63
  64 if [ $# -ne 0 ] && [ $# -ne 2 ]; then
  65     usage
  66 fi
  67
  68 if ! bitcount prefix "$netmask"; then
  69     printf "Invalid netmask (%s)\n" "$netmask" >&2
  70     exit 1
  71 fi
  72
  73 # complement of the netmask, i.e. the hostmask
  74 hostmask=$((netmask ^ 0xffffffff))
  75 network=$((ipaddr & netmask))
  76 broadcast=$((network | hostmask))
  77
  78 _ip2str IP "$ipaddr"
  79 _ip2str NETMASK "$netmask"
  80 _ip2str NETWORK "$network"
  81
  82 echo "IP=$IP"
  83 echo "NETMASK=$NETMASK"
  84 if [ "$prefix" -le 30 ]; then
  85     _ip2str BROADCAST "$broadcast"
  86     echo "BROADCAST=$BROADCAST"
  87 fi
  88 echo "NETWORK=$NETWORK"
  89 echo "PREFIX=$prefix"
  90
  91 [ $# -eq 0 ] && exit 0
  92
  93 if [ "$prefix" -le 30 ]; then
  94     lower=$((network + 1))
  95 else
  96     lower="$network"
  97 fi
  98
  99 start="$1"
 100 assert_uint32 "$start" || exit 1
 101 start=$((network | (start & hostmask)))
 102 [ "$start" -lt "$lower" ] && start="$lower"
 103 [ "$start" -eq "$ipaddr" ] && start=$((start + 1))
 104
 105 if [ "$prefix" -le 30 ]; then
 106     upper=$(((network | hostmask) - 1))
 107 else
 108     upper="$network"
 109 fi
 110
 111 range="$2"
 112 assert_uint32 "$range" || exit 1
 113 end=$((start + range - 1))
 114 [ "$end" -gt "$upper" ] && end="$upper"
 115 [ "$end" -eq "$ipaddr" ] && end=$((end - 1))
 116
 117 if [ "$start" -gt "$end" ]; then
 118     echo "network ($NETWORK/$prefix) too small" >&2
 119     exit 1
 120 fi
 121
 122 _ip2str START "$start"
 123 _ip2str END "$end"
 124
 125 if [ "$start" -le "$ipaddr" ] && [ "$ipaddr" -le "$end" ]; then
 126     echo "error: address $IP inside range $START..$END" >&2
 127     exit 1
 128 fi
 129
 130 echo "START=$START"
 131 echo "END=$END"
 132
 133 exit 0