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in the config of the firewall rules (/etc/config/firewall)
the dest_ip and its mask are saved in this way.
the netmask is saved with the number of set bit format.
option 'dest_ip' '1.1.1.0/24' how I can convert the "24" to 255.255.255.0 (IP address format) with ash script of openwrt. Are there a predefined function that convert :
24 to 255.255.255.0 and are there another function that do the inverse. I mean convert
255.255.255.0 to 24 (Last edited by kallel on 23 Dec 2013, 16:42)
dunno if there are predefined function, but you could use this:
#/bin/sh
mask2cdr ()
{
# Assumes there's no "255." after a non-255 byte in the mask
local x=${1##*255.}
set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
x=${1%%$3*}
echo $(( $2 + (${#x}/4) ))
}
cdr2mask ()
{
# Number of args to shift, 255..255, first non-255 byte, zeroes
set -- $(( 5 - ($1 / 8) )) 255 255 255 255 $(( (255 << (8 - ($1 % 8))) & 255 )) 0 0 0
[ $1 -gt 1 ] && shift $1 || shift
echo ${1-0}.${2-0}.${3-0}.${4-0}
}
# examples:
mask2cdr 255.255.255.0
cdr2mask 24thnx to this thread: http://forums.gentoo.org/viewtopic-t-88 … art-0.html
Thank you very much
dunno if there are predefined function, but you could use this:
#/bin/sh mask2cdr () { # Assumes there's no "255." after a non-255 byte in the mask local x=${1##*255.} set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*} x=${1%%$3*} echo $(( $2 + (${#x}/4) )) } cdr2mask () { # Number of args to shift, 255..255, first non-255 byte, zeroes set -- $(( 5 - ($1 / 8) )) 255 255 255 255 $(( (255 << (8 - ($1 % 8))) & 255 )) 0 0 0 [ $1 -gt 1 ] && shift $1 || shift echo ${1-0}.${2-0}.${3-0}.${4-0} } # examples: mask2cdr 255.255.255.0 cdr2mask 24thnx to this thread: http://forums.gentoo.org/viewtopic-t-88 … art-0.html
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