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ipcalc.sh 1.85 KiB
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  • 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) {
    
    	n=split(ip,a,"\\.")
    
    	for (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;x++) {
    		ret=and(ip,255)"."ret
    		ip=rshift(ip,8)
    	}
    
    function compl32(v) {
    	ret=xor(v, 0xffffffff)
    	return ret
    }
    
    
    	slpos=index(ARGV[1],"/")
    	if (slpos == 0) {
    		ipaddr=ip2int(ARGV[1])
    
    		dotpos=index(ARGV[2],".")
    		if (dotpos == 0)
    			netmask=compl32(2**(32-int(ARGV[2]))-1)
    		else
    			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]
    	}
    
    
    	prefix=32-bitcount(compl32(netmask))
    
    	broadcast=or(network,compl32(netmask))
    
    	print "IP="int2ip(ipaddr)
    	print "NETMASK="int2ip(netmask)
    	print "BROADCAST="int2ip(broadcast)
    	print "NETWORK="int2ip(network)
    
    	# range calculations:
    	# ipcalc <ip> <netmask> <start> <num>
    
    	if (ARGC <= 3)
    		exit(0)
    
    	start=or(network,and(ip2int(ARGV[3]),compl32(netmask)))
    	limit=network+1
    	if (start<limit) start=limit
    
    	if (start==ipaddr) start=ipaddr+1
    
    
    	end=start+ARGV[4]
    	limit=or(network,compl32(netmask))-1
    	if (end>limit) end=limit
    
    	if (end==ipaddr) end=ipaddr-1
    
    
    	if (start>end) {
    		print "network ("int2ip(network)"/"prefix") too small" > "/dev/stderr"
    		exit(1)
    	}
    
    
    	if (ipaddr > start && ipaddr < end) {
    
    		print "warning: ipaddr inside range - this might not be supported in future releases of Openwrt" > "/dev/stderr"
    
    
    	print "START="int2ip(start)
    	print "END="int2ip(end)