update

add conditional compilation support
add multi core support

core/hy/ipmasker.go

@@ -0,0 +1,43 @@
+package hy
+
+import (
+	"net"
+)
+
+type ipMasker struct {
+	IPv4Mask net.IPMask
+	IPv6Mask net.IPMask
+}
+
+// Mask masks an address with the configured CIDR.
+// addr can be "host:port" or just host.
+func (m *ipMasker) Mask(addr string) string {
+	if m.IPv4Mask == nil && m.IPv6Mask == nil {
+		return addr
+	}
+
+	host, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		// just host
+		host, port = addr, ""
+	}
+	ip := net.ParseIP(host)
+	if ip == nil {
+		// not an IP address, return as is
+		return addr
+	}
+	if ip4 := ip.To4(); ip4 != nil && m.IPv4Mask != nil {
+		// IPv4
+		host = ip4.Mask(m.IPv4Mask).String()
+	} else if ip6 := ip.To16(); ip6 != nil && m.IPv6Mask != nil {
+		// IPv6
+		host = ip6.Mask(m.IPv6Mask).String()
+	}
+	if port != "" {
+		return net.JoinHostPort(host, port)
+	} else {
+		return host
+	}
+}
+
+var defaultIPMasker = &ipMasker{}