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Diffstat (limited to 'package/base-files/files/lib/functions/ipv4.sh')
| -rw-r--r-- | package/base-files/files/lib/functions/ipv4.sh | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/package/base-files/files/lib/functions/ipv4.sh b/package/base-files/files/lib/functions/ipv4.sh new file mode 100644 index 00000000000..d0b93dbcb9b --- /dev/null +++ b/package/base-files/files/lib/functions/ipv4.sh @@ -0,0 +1,268 @@ +uint_max=4294967295 + +d_10_0_0_0=167772160 +d_10_255_255_255=184549375 + +d_172_16_0_0=2886729728 +d_172_31_255_255=2887778303 + +d_192_168_0_0=3232235520 +d_192_168_255_255=3232301055 + +d_169_254_0_0=2851995648 +d_169_254_255_255=2852061183 + +d_127_0_0_0=2130706432 +d_127_255_255_255=2147483647 + +d_224_0_0_0=3758096384 +d_239_255_255_255=4026531839 + +# check that $1 is only base 10 digits, and that it doesn't +# exceed 2^32-1 +assert_uint32() { + local __n="$1" + + if [ -z "$__n" -o -n "${__n//[0-9]/}" ]; then + printf "Not a decimal integer (%s)\n" "$__n ">&2 + return 1 + fi + + if [ "$__n" -gt $uint_max ]; then + printf "Out of range (%s)\n" "$__n" >&2 + return 1 + fi + + if [ "$((__n + 0))" != "$__n" ]; then + printf "Not normalized notation (%s)\n" "$__n" >&2 + return 1 + fi + + return 0 +} + +# return a count of the number of bits set in $1 +bitcount() { + local __var="$1" __c="$2" + assert_uint32 "$__c" || return 1 + + __c=$((((__c >> 1) & 0x55555555) + (__c & 0x55555555))) + __c=$((((__c >> 2) & 0x33333333) + (__c & 0x33333333))) + __c=$((((__c >> 4) & 0x0f0f0f0f) + (__c & 0x0f0f0f0f))) + __c=$((((__c >> 8) & 0x00ff00ff) + (__c & 0x00ff00ff))) + __c=$((((__c >> 16) & 0x0000ffff) + (__c & 0x0000ffff))) + + export -- "$__var=$__c" +} + +# tedious but portable with busybox's limited shell +# we check each octet to be in the range of 0..255, +# and also make sure there's no extaneous characters. +str2ip() { + local __var="$1" __ip="$2" __n __val=0 + + case "$__ip" in + [0-9].*) + __n="${__ip:0:1}" + __ip="${__ip:2}" + ;; + [1-9][0-9].*) + __n="${__ip:0:2}" + __ip="${__ip:3}" + ;; + 1[0-9][0-9].*|2[0-4][0-9].*|25[0-5].*) + __n="${__ip:0:3}" + __ip="${__ip:4}" + ;; + *) + printf "Not a dotted quad (%s)\n" "$2" >&2 + return 1 + ;; + esac + + __val=$((__n << 24)) + + case "$__ip" in + [0-9].*) + __n="${__ip:0:1}" + __ip="${__ip:2}" + ;; + [1-9][0-9].*) + __n="${__ip:0:2}" + __ip="${__ip:3}" + ;; + 1[0-9][0-9].*|2[0-4][0-9].*|25[0-5].*) + __n="${__ip:0:3}" + __ip="${__ip:4}" + ;; + *) + printf "Not a dotted quad (%s)\n" "$2" >&2 + return 1 + ;; + esac + + __val=$((__val + (__n << 16))) + + case "$__ip" in + [0-9].*) + __n="${__ip:0:1}" + __ip="${__ip:2}" + ;; + [1-9][0-9].*) + __n="${__ip:0:2}" + __ip="${__ip:3}" + ;; + 1[0-9][0-9].*|2[0-4][0-9].*|25[0-5].*) + __n="${__ip:0:3}" + __ip="${__ip:4}" + ;; + *) + printf "Not a dotted quad (%s)\n" "$2" >&2 + return 1 + ;; + esac + + __val=$((__val + (__n << 8))) + + case "$__ip" in + [0-9]) + __n="${__ip:0:1}" + __ip="${__ip:1}" + ;; + [1-9][0-9]) + __n="${__ip:0:2}" + __ip="${__ip:2}" + ;; + 1[0-9][0-9]|2[0-4][0-9]|25[0-5]) + __n="${__ip:0:3}" + __ip="${__ip:3}" + ;; + *) + printf "Not a dotted quad (%s)\n" "$2" >&2 + return 1 + ;; + esac + + __val=$((__val + __n)) + + if [ -n "$__ip" ]; then + printf "Not a dotted quad (%s)\n" "$2" >&2 + return 1 + fi + + export -- "$__var=$__val" + return 0 +} + +# convert back from an integer to dotted-quad. +ip2str() { + local __var="$1" __n="$2" + assert_uint32 "$__n" || return 1 + + export -- "$__var=$((__n >> 24)).$(((__n >> 16) & 255)).$(((__n >> 8) & 255)).$((__n & 255))" +} + +# convert prefix into an integer bitmask +prefix2netmask() { + local __var="$1" __n="$2" + assert_uint32 "$__n" || return 1 + + if [ "$__n" -gt 32 ]; then + printf "Prefix out-of-range (%s)" "$__n" >&2 + return 1 + fi + + export -- "$__var=$(((~(uint_max >> __n)) & uint_max))" +} + +_is_contiguous() { + local __x="$1" # no checking done + local __y=$((~__x & uint_max)) + local __z=$(((__y + 1) & uint_max)) + + [ $((__z & __y)) -eq 0 ] +} + +# check argument as being contiguous upper bits (and yes, +# 0 doesn't have any discontiguous bits). +is_contiguous() { + local __var="$1" __x="$2" __val=0 + assert_uint32 "$__x" || return 1 + + local __y=$((~__x & uint_max)) + local __z=$(((__y + 1) & uint_max)) + + [ $((__z & __y)) -eq 0 ] && __val=1 + + export -- "$__var=$__val" +} + +# convert mask to prefix, validating that it's a conventional +# (contiguous) netmask. +netmask2prefix() { + local __var="$1" __n="$2" __cont __bits + assert_uint32 "$__n" || return 1 + + is_contiguous __cont "$__n" || return 1 + if [ $__cont -eq 0 ]; then + printf "Not a contiguous netmask (%08x)\n" "$__n" >&2 + return 1 + fi + + bitcount __bits "$__n" # already checked + + export -- "$__var=$__bits" +} + +# check the argument as being an rfc-1918 address +is_rfc1918() { + local __var="$1" __x="$2" __val=0 + assert_uint32 "$__x" || return 1 + + if [ $d_10_0_0_0 -le $__x ] && [ $__x -le $d_10_255_255_255 ]; then + __val=1 + elif [ $d_172_16_0_0 -le $__x ] && [ $__x -le $d_172_31_255_255 ]; then + __val=1 + elif [ $d_192_168_0_0 -le $__x ] && [ $__x -le $d_192_168_255_255 ]; then + __val=1 + fi + + export -- "$__var=$__val" +} + +# check the argument as being an rfc-3927 address +is_rfc3927() { + local __var="$1" __x="$2" __val=0 + assert_uint32 "$__x" || return 1 + + if [ $d_169_254_0_0 -le $__x ] && [ $__x -le $d_169_254_255_255 ]; then + __val=1 + fi + + export -- "$__var=$__val" +} + +# check the argument as being an rfc-1122 loopback address +is_loopback() { + local __var="$1" __x="$2" __val=0 + assert_uint32 "$__x" || return 1 + + if [ $d_127_0_0_0 -le $__x ] && [ $__x -le $d_127_255_255_255 ]; then + __val=1 + fi + + export -- "$__var=$__val" +} + +# check the argument as being a multicast address +is_multicast() { + local __var="$1" __x="$2" __val=0 + assert_uint32 "$__x" || return 1 + + if [ $d_224_0_0_0 -le $__x ] && [ $__x -le $d_239_255_255_255 ]; then + __val=1 + fi + + export -- "$__var=$__val" +} + |