1 files changed, 71 insertions, 0 deletions
diff --git a/package/base-files/files/bin/ipcalc.sh b/package/base-files/files/bin/ipcalc.sh
new file mode 100755
index 0000000..5d5eac3
--- /dev/null
+++ b/package/base-files/files/bin/ipcalc.sh
@@ -0,0 +1,71 @@
+#!/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])
+		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]
+	}
+
+	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