netutil: imp code

netutil/ip.go

@@ -185,6 +185,7 @@ func SingleIPSubnet(ip net.IP) (n *net.IPNet) {
 //
 // Any error returned will have the underlying type of *AddrError.
 func ValidateIP(ip net.IP) (err error) {
+	// TODO(a.garipov):  Get rid of unnecessary allocations in case of valid IP.
 	defer makeAddrError(&err, ip.String(), AddrKindIP)
 
 	switch l := len(ip); l {

netutil/subnetset.go

@@ -85,13 +85,15 @@ func NewEmptySubnetSet() (ss SubnetSet) { return SubnetSetFunc(func(net.IP) bool
 func NewAnySubnetSet() (ss SubnetSet) {
 	// Use a couple of *net.IPNet since it seems being faster than validating
 	// with ValidateIP, see BenchmarkNewAnySubnetSet.
-	return NewSubnetSet(&net.IPNet{
-		IP:   make(net.IP, net.IPv4len),
-		Mask: make(net.IPMask, net.IPv4len),
-	}, &net.IPNet{
-		IP:   make(net.IP, net.IPv6len),
-		Mask: make(net.IPMask, net.IPv6len),
-	})
+	return &sliceSubnetSet{
+		nets: []*net.IPNet{{
+			IP:   make(net.IP, net.IPv4len),
+			Mask: make(net.IPMask, net.IPv4len),
+		}, {
+			IP:   make(net.IP, net.IPv6len),
+			Mask: make(net.IPMask, net.IPv6len),
+		}},
+	}
 }
 
 // IsLocallyServed checks if ip belongs to any network defined by RFC 6303:

netutil/subnetset_test.go

@@ -323,13 +323,11 @@ func BenchmarkSubnetSet_optimized(b *testing.B) {
 	})
 }
 
-func isValidIP(ip net.IP) (ok bool) {
-	return netutil.ValidateIP(ip) == nil
-}
-
 func BenchmarkNewAnySubnetSet(b *testing.B) {
 	ipnetBased := netutil.NewAnySubnetSet()
-	funcBased := netutil.SubnetSetFunc(isValidIP)
+	funcBased := netutil.SubnetSetFunc(func(ip net.IP) (ok bool) {
+		return netutil.ValidateIP(ip) == nil
+	})
 
 	// Create a bunch of random IP addresses.
 	ips := make([]net.IP, 128)