openwrtv4/package/base-files/files/bin/ipcalc.sh
Jo-Philipp Wich ab6e2e6928 base-files: ipcalc.sh: fix broken calculations on 64bit systems
Calculate complements by using awk's xor() function with a mask of 0xffffffff
instead of relying on the compl() function which appears to produce broken
results on certain 64bit architectures.

SVN-Revision: 34875
2012-12-23 22:18:43 +00:00

67 lines
1.4 KiB
Bash
Executable file

#!/bin/sh
awk -f - $* <<EOF
function bitcount(c) {
c=and(rshift(c, 1),0x55555555)+and(c,0x55555555)
c=and(rshift(c, 2),0x33333333)+and(c,0x33333333)
c=and(rshift(c, 4),0x0f0f0f0f)+and(c,0x0f0f0f0f)
c=and(rshift(c, 8),0x00ff00ff)+and(c,0x00ff00ff)
c=and(rshift(c,16),0x0000ffff)+and(c,0x0000ffff)
return c
}
function ip2int(ip) {
for (ret=0,n=split(ip,a,"\."),x=1;x<=n;x++) ret=or(lshift(ret,8),a[x])
return ret
}
function int2ip(ip,ret,x) {
ret=and(ip,255)
ip=rshift(ip,8)
for(;x<3;ret=and(ip,255)"."ret,ip=rshift(ip,8),x++);
return ret
}
function compl32(v) {
ret=xor(v, 0xffffffff)
return ret
}
BEGIN {
slpos=index(ARGV[1],"/")
if (slpos == 0) {
ipaddr=ip2int(ARGV[1])
netmask=ip2int(ARGV[2])
} else {
ipaddr=ip2int(substr(ARGV[1],0,slpos-1))
netmask=compl32(2**(32-int(substr(ARGV[1],slpos+1)))-1)
ARGV[4]=ARGV[3]
ARGV[3]=ARGV[2]
}
network=and(ipaddr,netmask)
broadcast=or(network,compl32(netmask))
start=or(network,and(ip2int(ARGV[3]),compl32(netmask)))
limit=network+1
if (start<limit) start=limit
end=start+ARGV[4]
limit=or(network,compl32(netmask))-1
if (end>limit) end=limit
print "IP="int2ip(ipaddr)
print "NETMASK="int2ip(netmask)
print "BROADCAST="int2ip(broadcast)
print "NETWORK="int2ip(network)
print "PREFIX="32-bitcount(compl32(netmask))
# range calculations:
# ipcalc <ip> <netmask> <start> <num>
if (ARGC > 3) {
print "START="int2ip(start)
print "END="int2ip(end)
}
}
EOF