package/base-files/files/lib/functions/ipv4.sh

   1 uint_max=4294967295
   2
   3 assert_uint32() {
   4     local __n="$1"
   5
   6     if [ -z "$__n" -o -n "${__n//[0-9]/}" ]; then
   7         printf "Not a decimal integer (%s)\n" "$__n ">&2
   8         return 1
   9     fi
  10
  11     if [ "$__n" -gt $uint_max ]; then
  12         printf "Out of range (%s)\n" "$__n" >&2
  13         return 1
  14     fi
  15
  16     if [ "$((__n + 0))" != "$__n" ]; then
  17         printf "Not normalized notation (%s)\n" "$__n" >&2
  18         return 1
  19     fi
  20
  21     return 0
  22 }
  23
  24 bitcount() {
  25     local __var="$1" __c="$2"
  26     assert_uint32 "$__c" || return 1
  27
  28     __c=$((((__c >> 1) & 0x55555555) + (__c & 0x55555555)))
  29     __c=$((((__c >> 2) & 0x33333333) + (__c & 0x33333333)))
  30     __c=$((((__c >> 4) & 0x0f0f0f0f) + (__c & 0x0f0f0f0f)))
  31     __c=$((((__c >> 8) & 0x00ff00ff) + (__c & 0x00ff00ff)))
  32     __c=$((((__c >> 16) & 0x0000ffff) + (__c & 0x0000ffff)))
  33
  34     export -- "$__var=$__c"
  35 }
  36
  37 # tedious but portable with busybox's limited shell
  38 str2ip() {
  39     local __var="$1" __ip="$2" __n __val=0
  40
  41     case "$__ip" in
  42     [0-9].*)
  43         __n="${__ip:0:1}"
  44         __ip="${__ip:2}"
  45         ;;
  46     [1-9][0-9].*)
  47         __n="${__ip:0:2}"
  48         __ip="${__ip:3}"
  49         ;;
  50     1[0-9][0-9].*|2[0-4][0-9].*|25[0-5].*)
  51         __n="${__ip:0:3}"
  52         __ip="${__ip:4}"
  53         ;;
  54     *)
  55         printf "Not a dotted quad (%s)\n" "$2" >&2
  56         return 1
  57         ;;
  58     esac
  59
  60     __val=$((__n << 24))
  61
  62     case "$__ip" in
  63     [0-9].*)
  64         __n="${__ip:0:1}"
  65         __ip="${__ip:2}"
  66         ;;
  67     [1-9][0-9].*)
  68         __n="${__ip:0:2}"
  69         __ip="${__ip:3}"
  70         ;;
  71     1[0-9][0-9].*|2[0-4][0-9].*|25[0-5].*)
  72         __n="${__ip:0:3}"
  73         __ip="${__ip:4}"
  74         ;;
  75     *)
  76         printf "Not a dotted quad (%s)\n" "$2" >&2
  77         return 1
  78         ;;
  79     esac
  80
  81     __val=$((__val + (__n << 16)))
  82
  83     case "$__ip" in
  84     [0-9].*)
  85         __n="${__ip:0:1}"
  86         __ip="${__ip:2}"
  87         ;;
  88     [1-9][0-9].*)
  89         __n="${__ip:0:2}"
  90         __ip="${__ip:3}"
  91         ;;
  92     1[0-9][0-9].*|2[0-4][0-9].*|25[0-5].*)
  93         __n="${__ip:0:3}"
  94         __ip="${__ip:4}"
  95         ;;
  96     *)
  97         printf "Not a dotted quad (%s)\n" "$2" >&2
  98         return 1
  99         ;;
 100     esac
 101
 102     __val=$((__val + (__n << 8)))
 103
 104     case "$__ip" in
 105     [0-9])
 106         __n="${__ip:0:1}"
 107         __ip="${__ip:1}"
 108         ;;
 109     [1-9][0-9])
 110         __n="${__ip:0:2}"
 111         __ip="${__ip:2}"
 112         ;;
 113     1[0-9][0-9]|2[0-4][0-9]|25[0-5])
 114         __n="${__ip:0:3}"
 115         __ip="${__ip:3}"
 116         ;;
 117     *)
 118         printf "Not a dotted quad (%s)\n" "$2" >&2
 119         return 1
 120         ;;
 121     esac
 122
 123     __val=$((__val + __n))
 124
 125     if [ -n "$__ip" ]; then
 126         printf "Not a dotted quad (%s)\n" "$2" >&2
 127         return 1
 128     fi
 129
 130     export -- "$__var=$__val"
 131     return 0
 132 }
 133
 134 ip2str() {
 135     local __var="$1" __n="$2"
 136     assert_uint32 "$__n" || return 1
 137
 138     export -- "$__var=$((__n >> 24)).$(((__n >> 16) & 255)).$(((__n >> 8) & 255)).$((__n & 255))"
 139 }
 140