openwrt/package/base-files/files/usr/lib/common.awk

# Copyright (C) 2006 OpenWrt.org

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 validate_netmask(nm) {
	return and(-nm,compl(nm))
}

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
}